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Sample records for short day exposure

  1. Short term exposure to cooking fumes and pulmonary function

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    Qvenild Torgunn

    2009-05-01

    Full Text Available Abstract Background Exposure to cooking fumes may have different deleterious effects on the respiratory system. The aim of this study was to look at possible effects from inhalation of cooking fumes on pulmonary function. Methods Two groups of 12 healthy volunteers (A and B stayed in a model kitchen for two and four hours respectively, and were monitored with spirometry four times during twenty four hours, on one occasion without any exposure, and on another with exposure to controlled levels of cooking fumes. Results The change in spirometric values during the day with exposure to cooking fumes, were not statistically significantly different from the changes during the day without exposure, with the exception of forced expiratory time (FET. The change in FET from entering the kitchen until six hours later, was significantly prolonged between the exposed and the unexposed day with a 15.7% increase on the exposed day, compared to a 3.2% decrease during the unexposed day (p-value = 0.03. The same tendency could be seen for FET measurements done immediately after the exposure and on the next morning, but this was not statistically significant. Conclusion In our experimental setting, there seems to be minor short term spirometric effects, mainly affecting FET, from short term exposure to cooking fumes.

  2. Flower formation in the short-day plant Kalanchoe by grafting with a long-day and a short-long-day Echeveria

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    Zeevaart, J.A.D.

    1978-01-01

    Flower formation was induced in the short-day plant Kalanchoe blossfeldiana Poellnitz under long-day conditions by grafting with flowering shoots of the short-long-day plant Echeveria harmsii (Rose) MacBr. and of the long-day plant Echeveria ''pulvoliver'' (E. pulvinata Rose x E. harmsii). Vegetative shoots from induced Echeveria plants failed to cause a flowering response in Kalanchoe. The presence of flowering and vegetative shoots side by side on induced Echeveria plants provides evidence for physiological chimeras in this genus.

  3. Effects of Short-Term Hypergravity Exposure are Reversible in Triticum aestivum L. Caryopses

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    Dixit, Jyotsana P.; Jagtap, Sagar S.; Kamble, Shailendra M.; Vidyasagar, Pandit B.

    2017-10-01

    Short-term hypergravity exposure is shown to retard seed germination, growth and photosynthesis in wheat caryopses. This study investigates the reversibility of effects of short-term hypergravity on imbibed wheat ( Triticum aestivum var L.) caryopses. After hypergravity exposure (500 × g - 2500 × g for 10 min) on a centrifuge, exposed caryopses were kept under normal gravity (1 × g) up to six days and then sown on agar. Results of the present study showed that percentage germination and growth were completely restored for DAY 6 compared to DAY 0. Restoration of germination and growth was accompanied by increased α-amylase activity. The specific activity of antioxidative enzyme viz. catalase and guaiacol peroxidase was lowered on DAY 6 compared to DAY 0 suggesting an alleviation of oxidative cellular damage against hypergravity stress. Chlorophyll pigment recovery along with chlorophyll fluorescence (PI and Fv/Fm) on DAY 6 indicates a transient rather than permanent damage of the photosynthetic apparatus. Thus, our findings demonstrate that short-term hypergravity effects are reversible in wheat caryopses. The metabolic cause of restoration of seed germination and growth upon transferring the caryopses to normal gravity is performed by a reactivation of carbohydrate- metabolizing enzymes, α-amylase and alleviation of oxidative stress damage with subsequent recovery of chlorophyll biosynthesis and photosynthetic activity.

  4. Short-term exposure to air pollution and digital vascular function.

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    Ljungman, Petter L; Wilker, Elissa H; Rice, Mary B; Schwartz, Joel; Gold, Diane R; Koutrakis, Petros; Vita, Joseph A; Mitchell, Gary F; Vasan, Ramachandran S; Benjamin, Emelia J; Mittleman, Murray A; Hamburg, Naomi M

    2014-09-01

    We investigated associations between ambient air pollution and microvessel function measured by peripheral arterial tonometry between 2003 and 2008 in the Framingham Heart Study Offspring and Third Generation Cohorts. We measured particulate matter with aerodynamic diameter ≤2.5 µm (PM2.5), black carbon, sulfates, particle number, nitrogen oxides, and ozone by using fixed monitors, and we determined moving averages for 1-7 days preceding vascular testing. We examined associations between these exposures and hyperemic response to ischemia and baseline pulse amplitude, a measure of arterial tone (n = 2,369). Higher short-term exposure to air pollutants, including PM2.5, black carbon, and particle number was associated with higher baseline pulse amplitude. For example, higher 3-day average PM2.5 exposure was associated with 6.3% higher baseline pulse amplitude (95% confidence interval: 2.0, 10.9). However, there were no consistent associations between the air pollution exposures assessed and hyperemic response. Our findings in a community-based sample exposed to relatively low pollution levels suggest that short-term exposure to ambient particulate pollution is not associated with vasodilator response, but that particulate air pollution is associated with baseline pulse amplitude, suggesting potentially adverse alterations in baseline vascular tone or compliance. © The Author 2014. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Financial results achieved in short-day strawberry production

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    Galić Dragan

    2014-01-01

    Full Text Available In South-western Ontario's continental climate (short days, hot summers and very cold winters the matted-row system was the dominant production system to grow short-day strawberries. Varieties-staggered production (planting a combination of early, mid and late-season varieties provides strawberry harvest from five to seven weeks. Short-day strawberries are vegetative grown in the first year, and harvested for two consecutive years. The total cost of short-day strawberry production was 54,370 $CAD/ha. The production and harvest costs in the first and second years were 20,812 $CAD/ha and 16,930 $CAD/ ha, respectively, and accounted for 69.42% of the total. Pre-plans operations were the least expensive procedures costing 8.13%, while planting and care of young plants made up 22.45% of the total costs. The total income of growing short-day strawberries under a matted-row system was 76,671 $CAD/ha (the first and second production years 41,330 $CAD/ha and 35,341 $CAD/ha, respectively. The short-day strawberries in matted-row system, with average yield of 15,722 kg/ha, generated a net revenue of 22,300 $CAD/ha.

  6. Is Impatiens balsamina a qualitative short-day plant?

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    Elżbieta Teske

    2014-01-01

    Full Text Available Impatiens balsamina which, in literature on the physiology of flowering, is assigned to qualitative short-day plants, flowers under Polish climatic conditions from June until September. It flowers, therefore. during the period of the longest day. The photoperiodic responses of I. balsamina plants raised from seeds obtained from botanical gardens located within the range of 23 -65° N. lat. were studied. The experiment revealed marked differences in the photoperiodic responses within the species. Qualitative short-day plants, quantitative short-day plants and day-neutral plants were found in the studied material. An evident correlation was found between the place of origin of the studied seeds and the photoperiodic sensitivity of the plants raised from them.

  7. Toxicological Effects of Caco-2 Cells Following Short-Term and Long-Term Exposure to Ag Nanoparticles

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    Ni Chen

    2016-06-01

    Full Text Available Extensive utilization increases the exposure of humans to Ag nanoparticles (NPs via the oral pathway. To comprehensively address the action of Ag NPs to the gastrointestinal systems in real situations, i.e., the long-term low-dose exposure, we evaluated and compared the toxicity of three Ag NPs (20–30 nm with different surface coatings to the human intestine cell Caco-2 after 1-day and 21-day exposures, using various biological assays. In both the short- and long-term exposures, the variety of surface coating predominated the toxicity of Ag NPs in a descending order of citrate-coated Ag NP (Ag-CIT, bare Ag NP (Ag-B, and poly (N-vinyl-2-pyrrolidone-coated Ag NP (Ag-PVP. The short-term exposure induced cell growth inhibition and death. The cell viability loss appeared after cells were exposed to 0.7 μg/mL Ag-CIT, 0.9 μg/mL Ag-B or >1.0 μg/mL Ag-PVP for 24 h. The short-term and higher-dose exposure also induced reactive oxygen species (ROS generation, mitochondrial damage, cell membrane leakage, apoptosis, and inflammation (IL-8 level. The long-term exposure only inhibited the cell proliferation. After 21-day exposure to 0.4 μg/mL Ag-CIT, the cell viability dropped to less than 50%, while cells exposed to 0.5 μg/mL Ag-PVP remained normal as the control. Generally, 0.3 μg/mL is the non-toxic dose for the long-term exposure of Caco-2 cells to Ag NPs in this study. However, cells presented inflammation after exposure to Ag NPs with the non-toxic dose in the long-term exposure.

  8. Effects of Short-term Hypergravity Exposure on Germination, Growth and Photosynthesis of Triticum aestivum L.

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    Vidyasagar, Pandit B.; Jagtap, Sagar S.; Dixit, Jyotsana P.; Kamble, Shailendra M.; Dhepe, Aarti P.

    2014-12-01

    Numerous studies have been carried out to investigate the hypergravity effect on plants, where seedlings (4-5 days old) were continuously exposed and grown under hypergravity condition. Here, we have used a novel `shortterm hypergravity exposure experimental method' where imbibed caryopses (instead of seedlings) were exposed to higher hypergravity values ranging from 500 g to 2500 g for a short interval time of 10 minutes and post short-term hypergravity treated caryopses were grown under 1 g conditions for five days. Changing patterns in caryopsis germination and growth, along with various photosynthetic and biochemical parameters were studied. Results revealed the significant inhibition of caryopsis germination and growth in short-term hypergravity treated seeds over control. Photosynthesis parameters such as chlorophyll content, rate of photosynthesis (PN), transpiration rate (Evap) and stomatal conductance (Gs), along with intracellular CO2 concentration (Cint) were found to be affected significantly in 5 days old seedlings exposed to short-term hypergravity treatment. In order to investigate the cause of observed inhibition, we examined the α-amylase activity and antioxidative enzyme activities. α-amylase activity was found to be inhibited, along with the reduction of sugars necessary for germination and earlier growth in short-term hypergravity treated caryopses. The activities of antioxidant enzymes such as catalase and guaiacol peroxidase were increased in short-term hypergravity treated caryopses, suggesting that caryopses might have experienced oxidative stress upon short-term hypergravity exposure.

  9. Short term effects of particle exposure on hospital admissions in the Mid-Atlantic states: a population estimate.

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    Itai Kloog

    Full Text Available Many studies report significant associations between PM(2.5 (particulate matter <2.5 micrometers and hospital admissions. These studies mostly rely on a limited number of monitors which introduces exposure error, and excludes rural and suburban populations from locations where monitors are not available, reducing generalizability and potentially creating selection bias.Using prediction models developed by our group, daily PM(2.5 exposure was estimated across the Mid-Atlantic (Washington D.C., and the states of Delaware, Maryland, New Jersey, Pennsylvania, Virginia, New York and West Virginia. We then investigated the short-term effects of PM(2.5exposures on emergency hospital admissions of the elderly in the Mid-Atlantic region.We performed case-crossover analysis for each admission type, matching on day of the week, month and year and defined the hazard period as lag01 (a moving average of day of admission exposure and previous day exposure.We observed associations between short-term exposure to PM(2.5 and hospitalization for all outcomes examined. For example, for every 10-µg/m(3 increase in short-term PM(2.5 there was a 2.2% increase in respiratory diseases admissions (95% CI = 1.9 to 2.6, and a 0.78% increase in cardiovascular disease (CVD admission rate (95% CI = 0.5 to 1.0. We found differences in risk for CVD admissions between people living in rural and urban areas. For every10-µg/m(3 increase in PM(2.5 exposure in the 'rural' group there was a 1.0% increase (95% CI = 0.6 to 1.5, while for the 'urban' group the increase was 0.7% (95% CI = 0.4 to 1.0.Our findings showed that PM(2.5 exposure was associated with hospital admissions for all respiratory, cardio vascular disease, stroke, ischemic heart disease and chronic obstructive pulmonary disease admissions. In addition, we demonstrate that our AOD (Aerosol Optical Depth based exposure models can be successfully applied to epidemiological studies investigating the health

  10. Short-Term Exposure to Air Pollution and Lung Function in the Framingham Heart Study

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    Ljungman, Petter L.; Wilker, Elissa H.; Gold, Diane R.; Schwartz, Joel D.; Koutrakis, Petros; Washko, George R.; O’Connor, George T.; Mittleman, Murray A.

    2013-01-01

    Rationale: Short-term exposure to ambient air pollution has been associated with lower lung function. Few studies have examined whether these associations are detectable at relatively low levels of pollution within current U.S. Environmental Protection Agency (EPA) standards. Objectives: To examine exposure to ambient air pollutants within EPA standards and lung function in a large cohort study. Methods: We included 3,262 participants of the Framingham Offspring and Third Generation cohorts living within 40 km of the Harvard Supersite monitor in Boston, Massachusetts (5,358 examinations, 1995–2011) who were not current smokers, with previous-day pollutant levels in compliance with EPA standards. We compared lung function (FEV1 and FVC) after previous-day exposure to particulate matter less than 2.5 μm in diameter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) in the “moderate” range of the EPA Air Quality Index to exposure in the “good” range. We also examined linear relationships between moving averages of pollutant concentrations 1, 2, 3, 5, and 7 days before spirometry and lung function. Measurements and Main Results: Exposure to pollutant concentrations in the “moderate” range of the EPA Air Quality Index was associated with a 20.1-ml lower FEV1 for PM2.5 (95% confidence interval [CI], −33.4, −6.9), a 30.6-ml lower FEV1 for NO2 (95% CI, −60.9, −0.2), and a 55.7-ml lower FEV1 for O3 (95% CI, −100.7, −10.8) compared with the “good” range. The 1- and 2-day moving averages of PM2.5, NO2, and O3 before testing were negatively associated with FEV1 and FVC. Conclusions: Short-term exposure to PM2.5, NO2, and O3 within current EPA standards was associated with lower lung function in this cohort of adults. PMID:24200465

  11. Long- and short-term exposure to PM2.5 and mortality: using novel exposure models.

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    Kloog, Itai; Ridgway, Bill; Koutrakis, Petros; Coull, Brent A; Schwartz, Joel D

    2013-07-01

    Many studies have reported associations between ambient particulate matter (PM) and adverse health effects, focused on either short-term (acute) or long-term (chronic) PM exposures. For chronic effects, the studied cohorts have rarely been representative of the population. We present a novel exposure model combining satellite aerosol optical depth and land-use data to investigate both the long- and short-term effects of PM2.5 exposures on population mortality in Massachusetts, United States, for the years 2000-2008. All deaths were geocoded. We performed two separate analyses: a time-series analysis (for short-term exposure) where counts in each geographic grid cell were regressed against cell-specific short-term PM2.5 exposure, temperature, socioeconomic data, lung cancer rates (as a surrogate for smoking), and a spline of time (to control for season and trends). In addition, for long-term exposure, we performed a relative incidence analysis using two long-term exposure metrics: regional 10 × 10 km PM2.5 predictions and local deviations from the cell average based on land use within 50 m of the residence. We tested whether these predicted the proportion of deaths from PM-related causes (cardiovascular and respiratory diseases). For short-term exposure, we found that for every 10-µg/m increase in PM 2.5 exposure there was a 2.8% increase in PM-related mortality (95% confidence interval [CI] = 2.0-3.5). For the long-term exposure at the grid cell level, we found an odds ratio (OR) for every 10-µg/m increase in long-term PM2.5 exposure of 1.6 (CI = 1.5-1.8) for particle-related diseases. Local PM2.5 had an OR of 1.4 (CI = 1.3-1.5), which was independent of and additive to the grid cell effect. We have developed a novel PM2.5 exposure model based on remote sensing data to assess both short- and long-term human exposures. Our approach allows us to gain spatial resolution in acute effects and an assessment of long-term effects in the entire population rather than a

  12. Short-term exposure to enriched environment rescues chronic stress-induced impaired hippocampal synaptic plasticity, anxiety, and memory deficits.

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    Bhagya, Venkanna Rao; Srikumar, Bettadapura N; Veena, Jayagopalan; Shankaranarayana Rao, Byrathnahalli S

    2017-08-01

    Exposure to prolonged stress results in structural and functional alterations in the hippocampus including reduced long-term potentiation (LTP), neurogenesis, spatial learning and working memory impairments, and enhanced anxiety-like behavior. On the other hand, enriched environment (EE) has beneficial effects on hippocampal structure and function, such as improved memory, increased hippocampal neurogenesis, and progressive synaptic plasticity. It is unclear whether exposure to short-term EE for 10 days can overcome restraint stress-induced cognitive deficits and impaired hippocampal plasticity. Consequently, the present study explored the beneficial effects of short-term EE on chronic stress-induced impaired LTP, working memory, and anxiety-like behavior. Male Wistar rats were subjected to chronic restraint stress (6 hr/day) over a period of 21 days, and then they were exposed to EE (6 hr/day) for 10 days. Restraint stress reduced hippocampal CA1-LTP, increased anxiety-like symptoms in elevated plus maze, and impaired working memory in T-maze task. Remarkably, EE facilitated hippocampal LTP, improved working memory performance, and completely overcame the effect of chronic stress on anxiety behavior. In conclusion, exposure to EE can bring out positive effects on synaptic plasticity in the hippocampus and thereby elicit its beneficial effects on cognitive functions. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. Short-term respiratory effects of cleaning exposures in female domestic cleaners.

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    Medina-Ramón, M; Zock, J P; Kogevinas, M; Sunyer, J; Basagaña, X; Schwartz, J; Burge, P S; Moore, V; Antó, J M

    2006-06-01

    Symptoms of obstructive lung disease in domestic cleaners have been related to the use of bleach and other irritant cleaning products. The short-term effects of cleaning exposures on respiratory symptoms and peak expiratory flow (PEF) were investigated in domestic cleaners with respiratory disorders. In a panel study, 43 female domestic cleaners with a recent history of asthma and/or chronic bronchitis completed a 2-week diary, collecting information on respiratory symptoms, PEF and cleaning exposures. Mixed regression models were used to assess daily changes in symptoms and PEF associated with specific cleaning exposures. The probability of having work-related asthma was individually assessed by a computerised diagnostic system and an occupational asthma expert. Lower respiratory tract symptoms were more common on working days and were predominantly associated with exposure to diluted bleach, degreasing sprays/atomisers and air fresheners. Associations with upper respiratory tract symptoms and PEF were less apparent. Eleven (30%) subjects scored positively for work-related asthma. It is concluded that exposure to certain irritant cleaning products aggravates lower respiratory tract symptoms in female domestic cleaners with asthma or chronic bronchitis.

  14. Effects of elevated CO[sub 2] on time of flowering in four short-day and four long-day species

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    Reekie, J.Y.C.; Hicklenton, P.R. (Agriculture Canada Research Station, Kentiville, NS (Canada)); Reekie, E.G. (Acadia Univ., Wolfville, NS (Canada))

    1994-01-01

    A study was undertaken to determine if the effect of elevated CO[sub 2] on flowering phenology is a function of the photoperiodic response of the species involved. Four long-day plants, Achillea millefolium, Callistephus chinensis, Campanula isophylla, and Trachelium caeruleum, and four short-day plants, Dendranthema grandiflora, Kalanchoe blossfeldiana, Pharbitis nil, and Xanthium pensylvanicum, were grown under inductive photoperiods (9 h for short day and 17 h for long day) at either 350 or 1000 [mu]l/l CO[sub 2]. Time of visible flower bud formation, flower opening, and final plant biomass were assessed. Elevated CO[sub 2] advanced flower opening in all four long-day species and delayed flowering in all four short-day species. In the long-day species, the effect of CO[sub 2] was primarily on bud initiation; all four species formed buds earlier at high CO[sub 2]. Bud development, the difference in time between flower opening and bud initiation, was advanced in only one long-day species, Callistephus chinensis. Mixed results were obtained for the short-day species. Elevated CO[sub 2] exerted no effects on bud initiation but delayed bud development in Dendranthema and Kalanchoe. In Xanthium, bud initiation rather than bud development was delayed. Data on bud initiation and development were not obtained for Pharbitis. The negative effect of CO[sub 2] upon phenology in the short-day species was not associated with negative effects on growth. Elevated CO[sub 2] increased plant size in both long-day and short-day species. 26 refs., 4 tabs.

  15. Night work, light exposure and melatonin on work days and days off.

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    Daugaard, Stine; Garde, Anne Helene; Bonde, Jens Peter Ellekilde; Christoffersen, Jens; Hansen, Äse Marie; Markvart, Jakob; Schlünssen, Vivi; Skene, Debra J; Vistisen, Helene Tilma; Kolstad, Henrik A

    2017-01-01

    We aimed to examine the effects of night work on salivary melatonin concentration during and subsequent to night work and the mediating role of light. We included 254 day workers and 87 night workers who were followed during 322 work days and 301 days off work. Each day was defined as the 24 hour period starting from the beginning of a night shift or from waking in the mornings with day work and days off. Light levels were recorded and synchronized with diary information (start and end of sleep and work). On average, participants provided four saliva samples per day, and these were analyzed for melatonin concentration by liquid chromatography tandem mass spectrometry (LC-MS/MS). Differences between day and night workers on work days and days off were assessed with multilevel regression models with melatonin concentration as the primary outcome. All models were stratified or adjusted by time of day. For light exposure, we estimated the total, direct and indirect effects of night work on melatonin concentrations obtaining 95% confidence intervals through bootstrapping. On work days, night workers showed 15% lower salivary melatonin concentrations compared with day workers (-15.0%; 95% CI: -31.4%; 5.2%). During the night, light exposure mediated a melatonin suppression of approximately 6% (-5.9%, 95% CI: -10.2%; -1.5%). No mediating effect of light was seen during the day time. On days off, we observed no difference in melatonin concentrations between day and night workers. These findings are in accordance with a transient and partly light-mediated effect of night work on melatonin production.

  16. Lack of short-wavelength light during the school day delays dim light melatonin onset (DLMO) in middle school students.

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    Figueiro, Mariana G; Rea, Mark S

    2010-01-01

    Circadian timing affects sleep onset. Delayed sleep onset can reduce sleep duration in adolescents required to awake early for a fixed school schedule. The absence of short-wavelength ("blue") morning light, which helps entrain the circadian system, can hypothetically delay sleep onset and decrease sleep duration in adolescents. The goal of this study was to investigate whether removal of short-wavelength light during the morning hours delayed the onset of melatonin in young adults. Dim light melatonin onset (DLMO) was measured in eleven 8th-grade students before and after wearing orange glasses, which removed short-wavelength light, for a five-day school week. DLMO was significantly delayed (30 minutes) after the five-day intervention, demonstrating that short-wavelength light exposure during the day can be important for advancing circadian rhythms in students. Lack of short-wavelength light in the morning has been shown to delay the circadian clock in controlled laboratory conditions. The results presented here are the first to show, outside laboratory conditions, that removal of short-wavelength light in the morning hours can delay DLMO in 8th-grade students. These field data, consistent with results from controlled laboratory studies, are directly relevant to lighting practice in schools.

  17. Does exposure to GSM 900 MHz mobile phone radiation affect short-term memory of elementary school students?

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    Movvahedi, M M; Tavakkoli-Golpayegani, A; Mortazavi, S A R; Haghani, M; Razi, Z; Shojaie-Fard, M B; Zare, M; Mina, E; Mansourabadi, L; Nazari-Jahromi; Safari, A; Shokrpour, N; Mortazavi, S M J

    2014-05-01

    Now-a-days, children are exposed to mobile phone radiation at a very early age. We have previously shown that a large proportion of children in the city of Shiraz, Iran use mobile phones. Furthermore, we have indicated that the visual reaction time (VRT) of university students was significantly affected by a 10 min real/sham exposure to electromagnetic fields emitted by mobile phone. We found that these exposures decreased the reaction time which might lead to a better response to different hazards. We have also revealed that occupational exposures to radar radiations decreased the reaction time in radar workers. The purpose of this study was to investigate whether short-term exposure of elementary school students to radiofrequency (RF) radiation leads to changes in their reaction time and short-term memory. A total of 60 elementary school children ages ranging from 8 to 10 years studying at a public elementary school in Shiraz, Iran were enrolled in this study. Standardized computer-based tests of VRT and short-term memory (modified for children) were administered. The students were asked to perform some preliminary tests for orientation with the VRT test. After orientation, to reduce the random variation of measurements, each test was repeated ten times in both real and sham exposure phases. The time interval between the two subsequent sham and real exposure phases was 30 min. The mean ± standard deviation reaction times after a 10 min talk period and after a 10 min sham exposure (switched off mobile) period were 249.0 ± 82.3 ms and 252.9 ± 68.2 ms (P = 0.629), respectively. On the other hand, the mean short-term memory scores after the talk and sham exposure periods were 1062.60 ± 305.39, and 1003.84 ± 339.68 (P = 0.030), respectively. To the best of our knowledge, this is the first study to show that short-term exposure of elementary school students to RF radiation leads to the better performance of their short-term memory.

  18. Dim light at night disrupts the short-day response in Siberian hamsters.

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    Ikeno, Tomoko; Weil, Zachary M; Nelson, Randy J

    2014-02-01

    Photoperiodic regulation of physiology, morphology, and behavior is crucial for many animals to survive seasonally variable conditions unfavorable for reproduction and survival. The photoperiodic response in mammals is mediated by nocturnal secretion of melatonin under the control of a circadian clock. However, artificial light at night caused by recent urbanization may disrupt the circadian clock, as well as the photoperiodic response by blunting melatonin secretion. Here we examined the effect of dim light at night (dLAN) (5lux of light during the dark phase) on locomotor activity rhythms and short-day regulation of reproduction, body mass, pelage properties, and immune responses of male Siberian hamsters. Short-day animals reduced gonadal and body mass, decreased spermatid nuclei and sperm numbers, molted to a whiter pelage, and increased pelage density compared to long-day animals. However, animals that experienced short days with dLAN did not show these short-day responses. Moreover, short-day specific immune responses were altered in dLAN conditions. The nocturnal activity pattern was blunted in dLAN hamsters, consistent with the observation that dLAN changed expression of the circadian clock gene, Period1. In addition, we demonstrated that expression levels of genes implicated in the photoperiodic response, Mel-1a melatonin receptor, Eyes absent 3, thyroid stimulating hormone receptor, gonadotropin-releasing hormone, and gonadotropin-inhibitory hormone, were higher in dLAN animals than those in short-day animals. These results suggest that dLAN disturbs the circadian clock function and affects the molecular mechanisms of the photoperiodic response. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. [Secondhand smoke exposure at home and leisure time according to the day of the week (working and non-working day) in Barcelona].

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    Martínez-Sánchez, José M; Fu, Marcela; Schiaffino, Anna; Sureda, Xisca; Saltó, Esteve; Moncada, Albert; Ariza, Carles; Nebot, Manel; Pascual, José A; Fernández, Esteve

    2012-01-01

    The objective of this study is to describe the differences in the exposure to secondhand smoke (SHS) at home and at leisure time according to the day of the week (working and non-working day) which exposure occurs in Barcelona. We carried out a cross-sectional study of a representative sample of adult (>16 years) non-smokers in Barcelona before the Spanish smoking law came into effect (years 2004-2005). We studied the prevalence of exposure to SHS at home and leisure time by means of a questionnaire and a biomarker (salivary cotinine). The questionnaire included questions on exposure to SHS on working days and nonworking days. The prevalence of exposure to SHS at home was 27.4% (6.8% exposed only on working days, 5.7% exposed only on non-working days, and 14.9% exposed on both working and non-working days). The prevalence of exposure to SHS at leisure time was 61.3% (10.7% exposed only on working days, 13.6% exposed only on non-working days, and 37.0% exposed on both working and non-working days). The exposure to SHS only on non-working days at leisure time decreases with age (χ(2) of trend = 183.7; phome on working and non-working days showed higher levels of salivary cotinine concentration, regardless of sex, age group, and educational level. In conclusion, the exposure to SHS occurs mainly during leisure time. Questions on SHS exposure according to working and non-working days allow to characterizing the exposure to SHS, especially when the exposure occurs at leisure time.

  20. The C4 Model Grass Setaria Is a Short Day Plant with Secondary Long Day Genetic Regulation.

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    Doust, Andrew N; Mauro-Herrera, Margarita; Hodge, John G; Stromski, Jessica

    2017-01-01

    The effect of photoperiod (day:night ratio) on flowering time was investigated in the wild species, Setaria viridis , and in a set of recombinant inbred lines (RILs) derived from a cross between foxtail millet ( S. italica ) and its wild ancestor green foxtail ( S. viridis ). Photoperiods totaled 24 h, with three trials of 8:16, 12:12 and 16:8 light:dark hour regimes for the RIL population, and these plus 10:14 and 14:10 for the experiments with S. viridis alone. The response of S. viridis to light intensity as well as photoperiod was assessed by duplicating photoperiods at two light intensities (300 and 600 μmol.m -2 .s -1 ). In general, day lengths longer than 12 h delayed flowering time, although flowering time was also delayed in shorter day-lengths relative to the 12 h trial, even when daily flux in high intensity conditions exceeded that of the low intensity 12 h trial. Cluster analysis showed that the effect of photoperiod on flowering time differed between sets of RILs, with some being almost photoperiod insensitive and others being delayed with respect to the population as a whole in either short (8 or 12 h light) or long (16 h light) photoperiods. QTL results reveal a similar picture, with several major QTL colocalizing between the 8 and 12 h light trials, but with a partially different set of QTL identified in the 16 h trial. Major candidate genes for these QTL include several members of the PEBP protein family that includes Flowering Locus T (FT) homologs such as OsHd3a, OsRFT1, and ZCN8/12. Thus, Setaria is a short day plant (flowering quickest in short day conditions) whose flowering is delayed by long day lengths in a manner consistent with the responses of most other members of the grass family. However, the QTL results suggest that flowering time under long day conditions uses additional genetic pathways to those used under short day conditions.

  1. The C4 Model Grass Setaria Is a Short Day Plant with Secondary Long Day Genetic Regulation

    Directory of Open Access Journals (Sweden)

    Andrew N. Doust

    2017-07-01

    Full Text Available The effect of photoperiod (day:night ratio on flowering time was investigated in the wild species, Setaria viridis, and in a set of recombinant inbred lines (RILs derived from a cross between foxtail millet (S. italica and its wild ancestor green foxtail (S. viridis. Photoperiods totaled 24 h, with three trials of 8:16, 12:12 and 16:8 light:dark hour regimes for the RIL population, and these plus 10:14 and 14:10 for the experiments with S. viridis alone. The response of S. viridis to light intensity as well as photoperiod was assessed by duplicating photoperiods at two light intensities (300 and 600 μmol.m-2.s-1. In general, day lengths longer than 12 h delayed flowering time, although flowering time was also delayed in shorter day-lengths relative to the 12 h trial, even when daily flux in high intensity conditions exceeded that of the low intensity 12 h trial. Cluster analysis showed that the effect of photoperiod on flowering time differed between sets of RILs, with some being almost photoperiod insensitive and others being delayed with respect to the population as a whole in either short (8 or 12 h light or long (16 h light photoperiods. QTL results reveal a similar picture, with several major QTL colocalizing between the 8 and 12 h light trials, but with a partially different set of QTL identified in the 16 h trial. Major candidate genes for these QTL include several members of the PEBP protein family that includes Flowering Locus T (FT homologs such as OsHd3a, OsRFT1, and ZCN8/12. Thus, Setaria is a short day plant (flowering quickest in short day conditions whose flowering is delayed by long day lengths in a manner consistent with the responses of most other members of the grass family. However, the QTL results suggest that flowering time under long day conditions uses additional genetic pathways to those used under short day conditions.

  2. Adrenal, thyroid, and testicular hormone rhythms in male golden hamsters on long and short days

    International Nuclear Information System (INIS)

    Ottenweller, J.E.; Tapp, W.N.; Pitman, D.L.; Natelson, B.H.

    1987-01-01

    Plasma concentrations of adrenal, thyroid, and testicular hormones were measured at 4-h intervals around the clock in male hamsters on long (14:10-h light-dark cycle) and short (10:14-h light-dark cycle) days. Plasma corticosterone, cortisol, thyroxine (T 4 ), triiodothyronine (T 3 ), and testosterone rhythms were present on long days. The only one of these hormones to have a significant rhythm on short days was cortisol, but even its amplitude was suppressed compared with the cortisol rhythm on long days. Short days also lowered mean plasma levels of cortisol, T 4 , T 3 , and testosterone. Finally, short days raised the ratio of corticosterone to cortisol and lowered the ratio of T 4 to T 3 . Both ratios had significant rhythms on long days but not on short days. Because of the many interactions among adrenal, thyroid, and testicular hormone axes, it is unclear whether the primary effect of short days is on one of these endocrine systems or on another factor that has separate effects on each of the hormone rhythms that was measured. Nonetheless, it is clear that a major effect of short day lengths in hamsters is to suppress hormone rhythms. Explanations of photoperiodic effects that depend on endocrine mediation should take this into account

  3. Continuous 3-day exposure assessment of workplace manufacturing silver nanoparticles

    International Nuclear Information System (INIS)

    Lee, Ji Hyun; Ahn, Kangho; Kim, Sun Man; Jeon, Ki Soo; Lee, Jong Seong; Yu, Il Je

    2012-01-01

    With the increased production and widespread use of nanomaterials, human and environmental exposure to nanomaterials is inevitably increasing. Therefore, this study monitored the possible nanoparticle exposure at a workplace that manufactures silver nanoparticles. To estimate the potential exposure of workers, personal sampling, area monitoring, and real-time monitoring were conducted over 3 days using a scanning mobility particle sizer and dust monitor at a workplace where the workers handle nanomaterials. The area sampling concentrations obtained from the injection room showed the highest concentration, ranging from 0.00501 to 0.28873 mg/m 3 . However, apart from the injection room, none of the area samplings obtained from other locations showed a concentration higher than 0.0013 mg/m 3 . Meanwhile, the personal sampling concentrations ranged from 0.00004 to 0.00243 mg/m 3 over the 3 days of sampling, which was much lower than the silver TLV. The particle number concentrations at the silver nanoparticle manufacturing workplace were 911,170 (1st day), 1,631,230 (2nd day), and 1,265,024 (3rd day) particles/cm 3 with a size range of 15–710.5 nm during the operation of the reactor, while the concentration decreased to 877,364.9 (1st day), 492,732 (2nd day), and 344,343 (3rd day) particles/cm 3 when the reactor was stopped.

  4. Sleep-Wake Actigraphy and Light Exposure During Spaceflight - Short

    Science.gov (United States)

    Czeisler, Charles A.; Wright, Kenneth P., Jr.; Ronda, Joseph

    2009-01-01

    Sleep-Wake Actigraphy and Light Exposure During Spaceflight - Short (Sleep-Short) will examine the effects of spaceflight on the sleep of the astronauts during space shuttle missions. Advancing state-of-the-art technology for monitoring, diagnosing and assessing treatment of sleep patterns is vital to treating insomnia on Earth and in space.

  5. Studies on tritium incorporation into wheat plants after short-term exposure to atmospheric tritium

    International Nuclear Information System (INIS)

    Diabate, S.; Strack, S.; Raskob, W.

    1996-01-01

    The paper summarizes the results of a series of laboratory experiments to study the uptake, loss, conversion and translocation of tritium in wheat plants following a short-term exposure to atmospheric tritiated water vapour (HTO) under laboratory conditions. The experiments were accompanied by the development of a Plant-OBT-Model to calculate the tritium behaviour in wheat. Exposures of potted plants were carried out between anthesis and maturity, under day conditions at two different light intensities (900 μmol m -2 s -1 and 120 μmol m -2 s -1 photosynthetic active radiation) and under night conditions. In leaves, the tritium uptake into tissue water tritium (TWT) was about four times lower under night conditions than day conditions. Organically bound tritium (OBT) was generated in leaves, stems and ears under day as well as under night conditions. The initial relative OBT concentrations in leaves observed under night conditions were about 50% of those under day conditions. OBT was translocated into the grain in dependence on the growth rate of the grain. Due to incorporation of new organic matter with lower OBT concentration into the grain, the specific OBT concentrations decreased slightly until harvest but the total OBT was rather constant. Once translocation to grain has taken place, OBT is lost only slowly. The growth of the plants has been calibrated with the measured growth data of winter wheat and spring wheat. Subsequently, the tritium incorporation was calibrated using the results of the exposure experiments in the same year. The final OBT concentration in the grain can be predicted with sufficient precision. However, the modelling of the OBT formation and turnover processes right after exposure to tritium needs improvement. A comprehensive validation of the model with independent data sets is still necessary. (J.P.N.)

  6. Stress-related endocrinological and psychopathological effects of short- and long-term 50Hz electromagnetic field exposure in rats.

    Science.gov (United States)

    Szemerszky, Renáta; Zelena, Dóra; Barna, István; Bárdos, György

    2010-01-15

    It is believed that different electromagnetic fields do have beneficial and harmful biological effects. The aim of the present work was to study the long-term consequences of 50 Hz electromagnetic field (ELF-EMF) exposure with special focus on the development of chronic stress and stress-induced psychopathology. Adult male Sprague-Dawley rats were exposed to ELF-EMF (50 Hz, 0.5 mT) for 5 days, 8h daily (short) or for 4-6 weeks, 24h daily (long). Anxiety was studied in elevated plus maze test, whereas depression-like behavior of the long-treated group was examined in the forced swim test. Some days after behavioral examination, the animals were decapitated among resting conditions and organ weights, blood hormone levels as well as proopiomelanocortin mRNA level from the anterior lobe of the pituitary gland were measured. Both treatments were ineffective on somatic parameters, namely none of the changes characteristic to chronic stress (body weight reduction, thymus involution and adrenal gland hypertrophy) were present. An enhanced blood glucose level was found after prolonged ELF-EMF exposure (p=0.013). The hormonal stress reaction was similar in control and short-term exposed rats, but significant proopiomelanocortin elevation (pfloating time; p=0.006) were found following long-term ELF-EMF exposure. Taken together, long and continuous exposure to relatively high intensity electromagnetic field may count as a mild stress situation and could be a factor in the development of depressive state or metabolic disturbances. Although we should stress that the average intensity of the human exposure is normally much smaller than in the present experiment.

  7. Student's music exposure: Full-day personal dose measurements.

    Science.gov (United States)

    Washnik, Nilesh Jeevandas; Phillips, Susan L; Teglas, Sandra

    2016-01-01

    Previous studies have shown that collegiate level music students are exposed to potentially hazardous sound levels. Compared to professional musicians, collegiate level music students typically do not perform as frequently, but they are exposed to intense sounds during practice and rehearsal sessions. The purpose of the study was to determine the full-day exposure dose including individual practice and ensemble rehearsals for collegiate student musicians. Sixty-seven college students of classical music were recruited representing 17 primary instruments. Of these students, 57 completed 2 days of noise dose measurements using Cirrus doseBadge programed according to the National Institute for Occupational Safety and Health criterion. Sound exposure was measured for 2 days from morning to evening, ranging from 7 to 9 h. Twenty-eight out of 57 (49%) student musicians exceeded a 100% daily noise dose on at least 1 day of the two measurement days. Eleven student musicians (19%) exceeded 100% daily noise dose on both days. Fourteen students exceeded 100% dose during large ensemble rehearsals and eight students exceeded 100% dose during individual practice sessions. Approximately, half of the student musicians exceeded 100% noise dose on a typical college schedule. This finding indicates that a large proportion of collegiate student musicians are at risk of developing noise-induced hearing loss due to hazardous sound levels. Considering the current finding, there is a need to conduct hearing conservation programs in all music schools, and to educate student musicians about the use and importance of hearing protection devices for their hearing.

  8. Short-Term Nose-Only Water-Pipe (Shisha Smoking Exposure Accelerates Coagulation and Causes Cardiac Inflammation and Oxidative Stress in Mice

    Directory of Open Access Journals (Sweden)

    Abderrahim Nemmar

    2015-01-01

    Full Text Available Background/Aim: Water-pipe smoking (WPS has acquired worldwide popularity, and is disseminating particularly rapidly in Europe and North America. However, little is known about the short-term cardiovascular effects of WPS. Methods: Presently, we assessed the short-term cardiovascular effects of nose-only exposure to mainstream WPS in BALB/c mice for 30 min/day for 5 consecutive days. Control mice were exposed to air. At the end of the exposure period, several cardiovascular endpoints were measured. Results: WPS did not affect the number of leukocytes and the plasma concentrations of C-reactive protein, tumor necrosis factor α (TNFα and interleukin-6 (IL-6. Likewise, plasma levels of lipid peroxidation (LPO, reduced glutathione (GSH and catalase were not affected by WPS. By contrast, WPS aggravated in vivo thrombosis by shortening the thrombotic occlusion time in pial arterioles and venules. The number of circulating platelets was reduced by WPS suggesting the occurrence of platelet aggregation in vivo. Elevated concentrations of fibrinogen and plasminogen activator inhibitor-1 were seen after the exposure to WPS. Blood samples taken from mice exposed to WPS and exposed to adenosine diphosphate showed more platelet aggregation. The heart concentrations of IL-6 and TNFα were augmented by WPS. Likewise, heart levels of LPO, reactive oxygen species and the antioxidants catalase and GSH were increased by WPS. However, the systolic blood pressure and heart rate were not affected by WPS. Conclusion: It can be concluded that short-term exposure to WPS exerts procoagulatory effects and induce cardiac inflammation and oxidative stress. At the time point investigated, there was no evidence for blood inflammation or oxidative stress.

  9. Alteration in certain enzymological parameters of an Indian major carp, Cirrhinus mrigala exposed to short- and long-term exposure of clofibric acid and diclofenac.

    Science.gov (United States)

    Saravanan, Manoharan; Ramesh, Mathan; Petkam, Rakpong

    2013-12-01

    The extensive use of pharmaceuticals in human and veterinary medicine may enter the aquatic environment and pose a serious threat to non-target aquatic organisms like fish. In this study, Indian major carp Cirrhinus mrigala was exposed to different concentrations (1, 10 and 100 μg L⁻¹) of most commonly used pharmaceutical drugs clofibric acid (CA) and diclofenac (DCF) to evaluate its impacts on certain enzymological parameters during short- and long-term exposures. During short-term (96 h) exposure period, plasma glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and gill Na⁺/K⁺-ATPase activity were significantly altered at all concentrations of both the CA- and DCF-treated fish. In long-term exposure (35 days), gill Na⁺/K⁺-ATPase activity was found to be significantly increased at all concentration of CA and DCF exposures throughout the study period (except at the end of 7th day in 10 and 100 µg L⁻¹) . However, a biphasic trend was observed in plasma GOT and GPT activity when compared to the control groups. In both short- and long-term exposure, a significant (P < 0.01 and P < 0.05) changes were observed in all enzymological parameters of fish C. mrigala exposed to different concentrations of CA and DCF. The alterations of these enzymological parameters can be effectively used as potential biomarkers in monitoring of pharmaceutical toxicity in aquatic environment and organisms.

  10. Blood morphology and the levels of selected cytokines related to hematopoiesis in occupational short-term exposure to lead

    International Nuclear Information System (INIS)

    Dobrakowski, Michał; Boroń, Marta; Czuba, Zenon P.; Birkner, Ewa; Chwalba, Artur; Hudziec, Edyta; Kasperczyk, Sławomir

    2016-01-01

    The aim of the study was to investigate the influence of a short-term exposure to lead on the blood morphology and the levels of selected cytokines related to hematopoiesis in occupationally exposed workers. The study population included 37 males occupationally exposed to lead for 36 to 44 days. Their blood lead level raised from 10.7 ± 7.67 μg/dl at baseline to the level of 49.1 ± 14.1 μg/dl at the end of the study. The level of hemoglobin and values of MCH and MCHC were decreased due to a short-term exposure to lead by 2%, 2%, and 1%, respectively. The counts of WBC, LYM, and MXD increased significantly by 5%, 7%, and 35%. Similarly, the count of PLT increased by 7%, while PDW, MPV, and P-LCR decreased by 6%, 3%, and 9%, respectively. The levels of IL-7, G-CSF, HGF, PDGF AB/BB, SCF, and PECAM-1, decreased significantly by 30%, 33%, 8%, 30%, 25%, and 20%, respectively. A short-term occupational exposure to lead results in a decreased hemoglobin level and increased counts of WBC and PLT. Changes in counts and proportions of different types of leukocytes and decreased values of PLT indices, such as PDW, MPV, and P-LCR, due to the subacute lead-exposure may be associated with lead-induced decreased levels of cytokines related to hematopoiesis, including SCF, G-CSF, IL-7, and PDGF. - Highlights: • Subacute exposure to lead results in a decreased hemoglobin level. • Subacute exposure to lead results in increased counts of WBC and PLT. • Subacute exposure to lead decreases the levels of SCF, G-CSF, IL-7, and PDGF.

  11. Blood morphology and the levels of selected cytokines related to hematopoiesis in occupational short-term exposure to lead

    Energy Technology Data Exchange (ETDEWEB)

    Dobrakowski, Michał, E-mail: michal.dobrakowski@poczta.fm [Department of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808 Zabrze (Poland); Boroń, Marta [Institute of Occupational Medicine and Environmental Health in Sosnowiec, ul. Kościelna 13, 41-200 Sosnowiec (Poland); Czuba, Zenon P. [Department of Microbiology and Immunology, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808 Zabrze (Poland); Birkner, Ewa [Department of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808 Zabrze (Poland); Chwalba, Artur [SP ZOZ Municipal Hospital, Department of Internal Medicine, ul. Strzelców Bytomskich 11, 41-500 Chorzów (Poland); Hudziec, Edyta; Kasperczyk, Sławomir [Department of Biochemistry, School of Medicine with the Division of Dentistry, Medical University of Silesia, ul. Jordana 19, 41-808 Zabrze (Poland)

    2016-08-15

    The aim of the study was to investigate the influence of a short-term exposure to lead on the blood morphology and the levels of selected cytokines related to hematopoiesis in occupationally exposed workers. The study population included 37 males occupationally exposed to lead for 36 to 44 days. Their blood lead level raised from 10.7 ± 7.67 μg/dl at baseline to the level of 49.1 ± 14.1 μg/dl at the end of the study. The level of hemoglobin and values of MCH and MCHC were decreased due to a short-term exposure to lead by 2%, 2%, and 1%, respectively. The counts of WBC, LYM, and MXD increased significantly by 5%, 7%, and 35%. Similarly, the count of PLT increased by 7%, while PDW, MPV, and P-LCR decreased by 6%, 3%, and 9%, respectively. The levels of IL-7, G-CSF, HGF, PDGF AB/BB, SCF, and PECAM-1, decreased significantly by 30%, 33%, 8%, 30%, 25%, and 20%, respectively. A short-term occupational exposure to lead results in a decreased hemoglobin level and increased counts of WBC and PLT. Changes in counts and proportions of different types of leukocytes and decreased values of PLT indices, such as PDW, MPV, and P-LCR, due to the subacute lead-exposure may be associated with lead-induced decreased levels of cytokines related to hematopoiesis, including SCF, G-CSF, IL-7, and PDGF. - Highlights: • Subacute exposure to lead results in a decreased hemoglobin level. • Subacute exposure to lead results in increased counts of WBC and PLT. • Subacute exposure to lead decreases the levels of SCF, G-CSF, IL-7, and PDGF.

  12. Ambient Air Pollution and Risk for Ischemic Stroke: A Short-Term Exposure Assessment in South China

    Directory of Open Access Journals (Sweden)

    Pi Guo

    2017-09-01

    Full Text Available Data on the association between air pollution and risk of ischemic stroke in China are still limited. This study aimed to investigate the association between short-term exposure to ambient air pollution and risk of ischemic strokes in Guangzhou, the most densely-populated city in south China, using a large-scale multicenter database of stroke hospital admissions. Daily counts of ischemic stroke admissions over the study years 2013–2015 were obtained from the Guangzhou Cardiovascular and Cerebrovascular Disease Event Surveillance System. Daily particulate matter <2.5 μm in diameter (PM2.5, sulfur dioxide (SO2, nitrogen dioxide (NO2, ozone (O3, and meteorological data were collected. The associations between air pollutants and hospital admissions for stroke were examined using relative risks (RRs and their corresponding 95% confidence intervals (CIs based on time-series Poisson regression models, adjusting for temperature, public holiday, day of week, and temporal trends in stroke. Ischemic stroke admissions increased from 27,532 to 35,279 through 2013 to 2015, increasing by 28.14%. Parameter estimates for NO2 exposure were robust regardless of the model used. The association between same-day NO2 (RR = 1.0509, 95% CI: 1.0353–1.0668 exposure and stroke risk was significant when accounting for other air pollutants, day of the week, public holidays, temperature, and temporal trends in stroke events. Overall, we observed a borderline significant association between NO2 exposure modeled as an averaged lag effect and ischemic stroke risk. This study provides data on air pollution exposures and stroke risk, and contributes to better planning of clinical services and emergency contingency response for stroke.

  13. Cumulative exposure to carbon monoxide during the day

    Energy Technology Data Exchange (ETDEWEB)

    Joumard, R. (INRETS, 69 - Bron (FR))

    The carbon monoxide, CO, has the advantage of being very easily and accurately measured under various conditions. In addition, it allows the translation of CO concentrations into their biological effects. The cumulative CO exposure should be considered according to current environment conditions during a given period of life, e.g. the day. In addition, the translation of concentrations and exposure times of CO fixed on blood haemoglobine (carboxyhaemoglobine) depends on physiological factors such as age, size, sex, or physical activity. This paper gives some examples of CO exposure translated into curves of carboxyhaemoglobine: case of 92 persons whose schedule was studied in details, of customs officers whose exposure was measured during one week, or other theoretical cases. In all the cases studied, smoking is by far the first factor of pollution by carbon monoxide. If not considering this case, the CO contents observed are preoccupying for sensitive subjects (in particular children) only in very rare cases. Furthermore, this approach allows the assessment of maximal allowable concentrations during specific exposures (work, e.g. in a tunnel) by integrating them into normal life conditions and population current exposure.

  14. Short-term association between personal exposure to noise and heart rate variability: The RECORD MultiSensor Study.

    Science.gov (United States)

    El Aarbaoui, Tarik; Méline, Julie; Brondeel, Ruben; Chaix, Basile

    2017-12-01

    Studies revealed long-term associations between noise exposure and cardiovascular health, but the underlying short-term mechanisms remain uncertain. To explore the concomitant and lagged short-term associations between personal exposure to noise and heart rate variability (HRV) in a real life setting in the Île-de-France region. The RECORD MultiSensor Study collected between July 2014 and June 2015 noise and heart rate data for 75 participants, aged 34-74 years, in their living environments for 7 days using a personal dosimeter and electrocardiography (ECG) sensor on the chest. HRV parameters and noise levels were calculated for 5-min windows. Short-term relationships between noise level and log-transformed HRV parameters were assessed using mixed effects models with a random intercept for participants and a temporal autocorrelation structure, adjusted for heart rate, physical activity (accelerometry), and short-term trends. An increase by one dB(A) of A-weighted equivalent sound pressure level (Leq) was associated with a 0.97% concomitant increase of the Standard deviation of normal to normal intervals (SDNN) (95% CI: 0.92, 1.02), of 2.08% of the Low frequency band power (LF) (95% CI: 1.97, 2.18), of 1.30% of the High frequency band power (HF) (95% CI: 1.17, 1.43), and of 1.16% of the LF/HF ratio (95% CI: 1.10, 1.23). The analysis of lagged exposures to noise adjusted for the concomitant exposure illustrates the dynamic of recovery of the autonomic nervous system. Non-linear associations were documented with all HRV parameters with the exception of HF. Piecewise regression revealed that the association was almost 6 times stronger below than above 65 Leq dB(A) for the SDNN and LF/HF ratio. Personal noise exposure was found to be related to a concomitant increase of the overall HRV, with evidence of imbalance of the autonomic nervous system towards sympathetic activity, a pathway to increased cardiovascular morbidity and mortality. Copyright © 2017 Elsevier Ltd

  15. Positive association between short-term ambient air pollution exposure and children blood pressure in China-Result from the Seven Northeast Cities (SNEC) study.

    Science.gov (United States)

    Zeng, Xiao-Wen; Qian, Zhengmin Min; Vaughn, Michael G; Nelson, Erik J; Dharmage, Shyamali C; Bowatte, Gayan; Perret, Jennifer; Chen, Duo-Hong; Ma, Huimin; Lin, Shao; de Foy, Benjamin; Hu, Li-Wen; Yang, Bo-Yi; Xu, Shu-Li; Zhang, Chuan; Tian, Yan-Peng; Nian, Min; Wang, Jia; Xiao, Xiang; Bao, Wen-Wen; Zhang, Ya-Zhi; Dong, Guang-Hui

    2017-05-01

    The impact of ambient air pollution on health causes concerns in China. However, little is known about the association of short-term air pollution exposure with blood pressure (BP) in children. The goal of present study was to assess the association between short-term air pollution and BP in children from a highly polluted area in China. This study enrolled 9354 children in 24 elementary and middle schools (aged 5-17 years) from the Seven Northeast Cities (SNEC) study, respectively, during the period of 2012-2013. Ambient air pollutants, including particulate matter with an aerodynamic diameter of ≤10 μm (PM 10 ), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ) and ozone (O 3 ) on the days (1-5 days) preceding BP examination were collected from local air monitoring stations. Generalized additive models and two-level regression analyses were used to evaluate the relationship between air pollution and BP after adjusting for other covariates. Results showed that with an interquartile range (IQR) increase in PM 10 (50.0 μg/m 3 ) and O 3 (53.0 μg/m 3 ) level during the 5-day mean exposure, positive associations with elevated BP were observed, with an odds ratio of 2.17 (95% CI, 1.61-2.93) for PM 10 and 2.77 (95% CI, 1.94-3.95) for O 3 . Both systolic BP and diastolic BP levels were positively associated with an IQR increase of four air pollutants at different lag times. Specifically, an IQR increase in the 5-day mean of PM 10 and O 3 was associated with elevation of 2.07 mmHg (95% CI, 1.71-2.44) and 3.29 mmHg (95% CI, 2.86-3.72) in systolic BP, respectively. When stratified by sex, positive relationships were observed for elevated BP with NO 2 exposure only in males. This is the first report on the relationship between ambient short-term air pollution exposure and children BP in China. Findings indicate a need to control air pollutants and protect children from heavy air pollution exposure in China. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Dim light at night interferes with the development of the short-day phenotype and impairs cell-mediated immunity in Siberian hamsters (Phodopus sungorus).

    Science.gov (United States)

    Aubrecht, Taryn G; Weil, Zachary M; Nelson, Randy J

    2014-10-01

    Winter is a challenging time to survive and breed outside of the tropics. Animals use day length (photoperiod) to regulate seasonally appropriate adaptations in anticipation of challenging winter conditions. The net result of these photoperiod-mediated adjustments is enhanced immune function and increased survival. Thus, the ability to discriminate day length information is critical for survival and reproduction in small animals. However, during the past century, urban and suburban development has rapidly expanded and filled the night sky with light from various sources, obscuring crucial light-dark signals, which alters physiological interpretation of day lengths. Furthermore, reduced space, increased proximity to people, and the presence of light at night may act as stressors for small animals. Whereas acute stressors typically enhance immune responses, chronic exposure to stressors often impairs immune responses. Therefore, we hypothesized that the combination of dim light at night and chronic stress interferes with enhanced cell-mediated immunity observed during short days. Siberian hamsters (Phodopus sungorus) were assigned to short or long days with dark nights (0 lux) or dim (5 lux) light at night for 10 weeks. Following 2 weeks of chronic restraint (6 hr/day), a model of chronic stress, delayed type hypersensitivity (DTH) responses were assessed. Both dim light at night and restraint reduced the DTH response. Dim light at night during long nights produced an intermediate short day phenotype. These results suggest the constant presence of light at night could negatively affect survival of photoperiodic rodents by disrupting the timing of breeding and immune responses. © 2014 Wiley Periodicals, Inc.

  17. Exposure to infections through day-care attendance and risk of childhood leukaemia

    International Nuclear Information System (INIS)

    Urayama, K. Y.; Ma, X.; Buffler, P. A.

    2008-01-01

    There is growing evidence supporting a role for infections in the aetiology of childhood leukaemia. Hypotheses proposed by both Greaves and Kinlen describe childhood leukaemia to be a rare response to one or more common infections acquired through personal contacts. Previous epidemiological studies have used day-care attendance as an indicator of the increased likelihood of early and frequent exposure to infections. It is well-documented that in developed countries, exposures to common infections occur more frequently in this type of setting. Within the Northern California Childhood Leukaemia Study, the role of social contact has been assessed and a unique 'child-hours' summary measure incorporating information on the number of months attending a day-care, mean hours per week at this day-care and the number of children in the day-care setting was constructed. In this review, the previously reported day-care results have been described, showing that in non-Hispanic White children, children in the highest category of total child-hours of exposure had a reduced risk of acute lymphoblastic leukaemia (ALL), particularly common B-cell precursor ALL (c-ALL), compared with children without such exposures, with evidence of a dose-response effect. In addition, a literature review of relevant studies has been conducted, examining the relationship between day-care attendance and risk of childhood ALL. Overall, the 14 studies identified provided consistent support for this hypothesis, with the majority of studies reporting some evidence of a reduced risk. A meta-analysis is currently underway, which will provide a quantitative evaluation of the overall consistency and strength of the association between day-care attendance or social contact and risk of childhood ALL. (authors)

  18. Stochastic health effects assessment due to short-term external exposure

    International Nuclear Information System (INIS)

    Raicevic, J.J.; Raskob, W.; Merkle, M.; Ninkovic, M.M.

    2001-01-01

    The new model for calculation of stochastic health effects is presented in this paper. The exposure pathways which are briefly considered are the short-term external exposure due to passage of the radioactive cloud (cloudshine) and the short-term external exposure due to radioactive material deposited on skin and clothes (skin contamination). The quantitative assessment of stochastic effects is expressed in numbers of deaths, which are given as a functions of the time at the accident, and age at death, what on the other side enables estimation of the number of deaths within the specified range of the time/age parameters. That means the model calculates the number of deaths within one particular year, summed up over all ages at deaths, or vice versa, it finds the number of deaths within the specified range of ages at death, summed up over all observation times. Results presented in this paper are implemented in the module LATEHEAL, which is incorporated in RODOS, a new European system for decision support for nuclear emergencies. (author)

  19. A Short-Term Exposure to Tributyltin Blocks Leydig Cell Regeneration in the Adult Rat Testis

    Directory of Open Access Journals (Sweden)

    Xiaolong Wu

    2017-10-01

    Full Text Available Background: Tributyltin (TBT is widely used as an antifouling agent that may cause reproductive toxicity. The mechanism of TBT on Leydig cell development is still unknown. The objective of the present study was to investigate whether a brief exposure to low doses of TBT permanently affects Leydig cell development and to clarify the underlying mechanism.Methods: Adult male Sprague Dawley rats were randomly assigned into four groups and gavaged normal saline (control, 0.1, 1.0, or 10.0 mg/kg/day TBT for a consecutive 10 days, respectively. At the end of TBT treatment, all rats received a single intraperitoneal injection of 75 mg/kg ethane dimethane sulfonate (EDS to eliminate all of adult Leydig cells. Leydig cells began a developmental regeneration process on post-EDS day 35. The Leydig cell regeneration was evaluated by measuring serum testosterone, luteinizing hormone, and follicle-stimulating hormone levels on post-EDS day 7, 35, and 56, the expression levels of Leydig cell genes, Leydig cell morphology and number and proliferation on post-EDS day 56.Results: TBT significantly reduced serum testosterone levels on post-EDS day 35 and 56 and increased serum luteinizing hormone and follicle-stimulating hormone levels on post-EDS day 56 at ≥1 mg/kg/day. Immunohistochemical staining showed that there were fewer regenerated Leydig cells in the TBT-treated testis on post-EDS day 56. Further study demonstrated that the mRNA or protein levels of Leydig (Lhcgr, Cyp11a1, Hsd3b1, Cyp17a1, and Hsd17b3 and Sertoli cells (Fshr, Dhh, and Sox9 were significantly down-regulated in the TBT-treated testes when compared to the control. Immunofluorescent staining showed that TBT inhibited Leydig cell proliferation as judged by the reduced number of proliferating cyclin nuclear antigen-positive Leydig cells on post-EDS day 35.Conclusion: The present study demonstrated that a short-term TBT exposure blocked Leydig cell developmental regeneration process via down

  20. A Short-Term Exposure to Tributyltin Blocks Leydig Cell Regeneration in the Adult Rat Testis.

    Science.gov (United States)

    Wu, Xiaolong; Liu, Jianpeng; Duan, Yue; Gao, Shiyu; Lü, Yao; Li, Xiaoheng; Zhu, Qiqi; Chen, Xianwu; Lin, Jing; Ye, Leping; Ge, Ren-Shan

    2017-01-01

    Background: Tributyltin (TBT) is widely used as an antifouling agent that may cause reproductive toxicity. The mechanism of TBT on Leydig cell development is still unknown. The objective of the present study was to investigate whether a brief exposure to low doses of TBT permanently affects Leydig cell development and to clarify the underlying mechanism. Methods: Adult male Sprague Dawley rats were randomly assigned into four groups and gavaged normal saline (control), 0.1, 1.0, or 10.0 mg/kg/day TBT for a consecutive 10 days, respectively. At the end of TBT treatment, all rats received a single intraperitoneal injection of 75 mg/kg ethane dimethane sulfonate (EDS) to eliminate all of adult Leydig cells. Leydig cells began a developmental regeneration process on post-EDS day 35. The Leydig cell regeneration was evaluated by measuring serum testosterone, luteinizing hormone, and follicle-stimulating hormone levels on post-EDS day 7, 35, and 56, the expression levels of Leydig cell genes, Leydig cell morphology and number and proliferation on post-EDS day 56. Results: TBT significantly reduced serum testosterone levels on post-EDS day 35 and 56 and increased serum luteinizing hormone and follicle-stimulating hormone levels on post-EDS day 56 at ≥1 mg/kg/day. Immunohistochemical staining showed that there were fewer regenerated Leydig cells in the TBT-treated testis on post-EDS day 56. Further study demonstrated that the mRNA or protein levels of Leydig ( Lhcgr , Cyp11a1, Hsd3b1, Cyp17a1 , and Hsd17b3 ) and Sertoli cells ( Fshr , Dhh , and Sox9 ) were significantly down-regulated in the TBT-treated testes when compared to the control. Immunofluorescent staining showed that TBT inhibited Leydig cell proliferation as judged by the reduced number of proliferating cyclin nuclear antigen-positive Leydig cells on post-EDS day 35. Conclusion: The present study demonstrated that a short-term TBT exposure blocked Leydig cell developmental regeneration process via down

  1. Short-Term Systemic Effects of Nose-Only Cigarette Smoke Exposure in Mice: Role of Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Abderrahim Nemmar

    2013-01-01

    Full Text Available Background/Aims: Long–term cigarette smoking (CS is a major risk factor for respiratory and cardiovascular diseases, and is also known to adversely affect other organs. However, data on the systemic effects of short-term CS exposure (STCSE are scarce. Presently, using a nose-only exposure system, we evaluated the systemic effects of STCSE in mice. Methods: We assessed the effects of CS generated by 9 consecutive cigarettes per day for 4 days in a nose-only exposure system on cardiovascular, hepatic and renal endpoints evaluated on day 5 in mice. Control mice were exposed to air only. Results: CS significantly increased systolic blood pressure and decreased total nitric oxide plasma concentration. Circulating platelets and erythrocyte numbers were also increased. However, STCSE did not significantly increase thrombosis in pial arterioles and venules. STCSE significantly raised plasma alanine aminotransferase and gamma glutamyl transpeptidase activities, but did not affect urea or creatinine concentrations. Interestingly, while STCSE enhanced the production of reactive oxygen species in heart and kidney and lipid peroxidation in heart, liver and kidneys, it also enhanced the antioxidant activity of superoxide dismutase, probably indicating that STCSE causes adaptive reactions to counterbalance the potentially damaging action of oxygen radicals induced by STCSE. Conclusion: These results suggest that STCSE causes blood pressure increase, hepatotoxicity and oxidative stress in the heart, liver and the kidneys. These data provide information on the initial steps leading to the systemic effects of STCSE, a stage at which the diseases may likely be reversed.

  2. Meta-analysis of the association between short-term exposure to ambient ozone and respiratory hospital admissions

    International Nuclear Information System (INIS)

    Ji Meng; Bell, Michelle L; Cohan, Daniel S

    2011-01-01

    Ozone is associated with health impacts including respiratory outcomes; however, results differ across studies. Meta-analysis is an increasingly important approach to synthesizing evidence across studies. We conducted meta-analysis of short-term ozone exposure and respiratory hospitalizations to evaluate variation across studies and explore some of the challenges in meta-analysis. We identified 136 estimates from 96 studies and investigated how estimates differed by age, ozone metric, season, lag, region, disease category, and hospitalization type. Overall results indicate associations between ozone and various kinds of respiratory hospitalizations; however, study characteristics affected risk estimates. Estimates were similar, but higher, for the elderly compared to all ages and for previous day exposure compared to same day exposure. Comparison across studies was hindered by variation in definitions of disease categories, as some (e.g., asthma) were identified through ≥ 3 different sets of ICD codes. Although not all analyses exhibited evidence of publication bias, adjustment for publication bias generally lowered overall estimates. Emergency hospitalizations for total respiratory disease increased by 4.47% (95% interval: 2.48, 6.50%) per 10 ppb 24 h ozone among the elderly without adjustment for publication bias and 2.97% (1.05, 4.94%) with adjustment. Comparison of multi-city study results and meta-analysis based on single-city studies further suggested publication bias.

  3. Effects of repeated 9 and 30-day exposure to extremely low-frequency electromagnetic fields on social recognition behavior and estrogen receptors expression in olfactory bulb of Wistar female rats.

    Science.gov (United States)

    Bernal-Mondragón, C; Arriaga-Avila, V; Martínez-Abundis, E; Barrera-Mera, B; Mercado-Gómez, O; Guevara-Guzmán, R

    2017-02-01

    We investigated the short- and long-term effects of extremely low-frequency electromagnetic fields (EMF) on social recognition behavior and expression of α- and β-estrogen receptors (ER). Rats were exposed to 60-Hz electromagnetic fields for 9 or 30 days and tested for social recognition behavior. Immunohistochemistry and western blot assays were performed to evaluate α- and β-ER expression in the olfactory bulb of intact, ovariectomized (OVX), and ovariectomized+estradiol (E2) replacement (OVX+E2). Ovariectomization showed impairment of social recognition after 9 days of EMF exposure and a complete recovery after E2 replacement and so did those after 30 days. Short EMF exposure increased expression of β-ER in intact, but not in the others. Longer exposure produced a decrease in intact but an increase in OVX and OVX+E2. Our findings suggest a significant role for β-estrogen receptors and a lack of effect for α-estrogen receptors on a social recognition task. EMF: extremely low frequency electromagnetic fields; ERs: estrogen receptors; OB: olfactory bulb; OVX: ovariectomized; OVX + E 2 : ovariectomized + estradiol replacement; IEI: interexposure interval; β-ER: beta estrogen receptor; E 2 : replacement of estradiol; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; WB: Western blot; PBS: phosphate-buffer saline; PB: phosphate-buffer.

  4. Hematological effects of four ethylene glycol monoalkyl ethers in short-term repeated exposure in rats

    Energy Technology Data Exchange (ETDEWEB)

    Starek, Andrzej [Jagiellonian University, Department of Biochemical Toxicology, Medical College, Krakow (Poland); Szymczak, Wieslaw [University of Lodz, Institute of Psychology, Lodz (Poland); Zapor, Lidia [Central Institute for Labour Protection National Research Institute, Laboratory of Toxicology, Department of Chemical and Aerosol Hazards, Warsaw (Poland)

    2008-02-15

    This study was carried out to compare the hematological effects of 2-methoxyethanol (ME), 2-ethoxyethanol (EE), 2-isopropoxyethanol (IPE), and 2-butoxyethanol (BE) in short-term studies in rats. Male rats were subcutaneously treated with ME or EE at a dosage of 0, 1.25, 2.5 and 5.0 mM/kg in saline, 5 days per week, for 4 weeks. Other rats were exposed to IPE or BE at doses of 0, 0.25, 0.5, 0.75 and 1.25 mM/kg in the same manner. Administration of each chemical, except of ME, resulted in a time- and dose-dependent swelling of erythrocytes as evidenced by an increase in mean corpuscular volume (MCV). Subsequently, red blood cells (RBC), packed cell volumes (PCV), hemoglobin concentration (HGB), and mean cell hemoglobin concentration (MCHC) decreased. Furthermore, an increase in mean cell hemoglobin (MCH) and reticulocyte counts was observed. The onset of hemolysis induced by EE, IPE or BE was faster than after ME administration. While in rats exposed to ME hematological changes were strongly pronounced and progressively increased with exposure time beginning from the day 11, those in animals treated with EE were rather persisted at low constant level for all exposure period. In contrast, the rats exposed to IPE and BE demonstrated the dramatic hematological changes more pronounced in case of BE than IPE at the beginning of exposure (on day 4). Despite of exposure duration, these changes were regressed, although the decrease in RBC and MCHC and the increase in MCV and MCH in rats treated with highest doses of both compound (0.5, 0.75, and 1.25 mM/kg) were more persistent, probably due to selective hemolysis of the aged erythrocytes. In addition, significant leukopenia due to reduction of lymphocytes in rats exposed to ME was observed. In summary, this study demonstrated no tolerance to ME- and EE-induced intravascular hemolysis developed under these experimental conditions. On the contrary, tolerance to IPE- and BE-induced hemolysis in rats exposed to these compounds

  5. Predator avoidance performance of larval fathead minnows (Pimephales promelas) following short-term exposure to estrogen mixtures

    Science.gov (United States)

    McGee, M.R.; Julius, M.L.; Vajda, A.M.; Norris, D.O.; Barber, L.B.; Schoenfuss, H.L.

    2009-01-01

    Aquatic organisms exposed to endocrine disrupting compounds (EDCs) at early life-stages may have reduced reproductive fitness via disruption of reproductive and non-reproductive behavioral and physiological pathways. Survival to reproductive age relies upon optimal non-reproductive trait expression, such as adequate predator avoidance responses, which may be impacted through EDC exposure. During a predator–prey confrontation, larval fish use an innate C-start escape behavior to rapidly move away from an approaching threat. We tested the hypotheses that (1) larval fathead minnows exposed to estrogens, a primary class of EDCs, singularly or in mixture, suffer a reduced ability to perform an innate C-start behavior when faced with a threat stimulus; (2) additive effects will cause greater reductions in C-start behavior; and (3) effects will differ among developmental stages. In this study, embryos (post-fertilization until hatching) were exposed for 5 days to environmentally relevant concentrations of estrone (E1), 17β-estradiol (E2), and 17α-ethinylestradiol (EE2) singularly and in mixture. Exposed embryos were allowed to hatch and grow in control well water until 12 days old. Similarly, post-hatch fathead minnows were exposed for 12 days to these compounds. High-speed (1000 frames/s) video recordings of escape behavior were collected and transferred to National Institutes of Health Image for frame-by-frame analysis of latency period, escape velocity, and total escape response (combination of latency period and escape velocity). When tested 12 days post-hatch, only E1 adversely affected C-start performance of larvae exposed as embryos. Conversely, larvae exposed for 12 days post-hatch did not exhibit altered escape responses when exposed to E1, while adverse responses were seen in E2 and the estrogen mixture. Ethinylestradiol exposure did not elicit changes in escape behaviors at either developmental stage. The direct impact of reduced C-start performance on

  6. Astrophotography on the go using short exposures with light mounts

    CERN Document Server

    Ashley, Joseph

    2015-01-01

    No longer are heavy, sturdy, expensive mounts and tripods required to photograph deep space. With today's advances in technology, all that is required is an entry-DSLR and an entry level GoTo telescope. Here is all of the information needed to start photographing the night sky without buying expensive tracking mounts. By using multiple short exposures and combining them with mostly ‘freeware’ computer programs, the effect of image rotation can be minimized to a point where it is undetectable in normal astrophotography, even for a deep-sky object such as a galaxy or nebula. All the processes, techniques, and equipment needed to use inexpensive, lightweight altazimuth and equatorial mounts and very short exposures photography to image deep space objects are explained, step-by-step, in full detail, supported by clear, easy to understand graphics and photographs.   Currently available lightweight mounts and tripods are identified and examined from an economic versus capability perspective to help users deter...

  7. Susceptibility to hypoxia and breathing control changes after short-term cold exposures

    Directory of Open Access Journals (Sweden)

    Lyudmila T. Kovtun

    2013-08-01

    Full Text Available Background . Hypoxia is the reduction of oxygen availability due to external or internal causes. There is large individual variability of response to hypoxia. Objective . The aim of this study was to define individual and typological features in susceptibility to hypoxia, its interrelation with hypoxic and hypercapnic ventilatory responses (HVR and HCVR, respectively and their changes after cold acclimation. Design . Twenty-four healthy men were tested. HVR and HCVR were measured by the rebreathing method during hypoxic and hypercapnic tests, respectively. These tests were carried out in thermoneutral conditions before and after cold exposures (nude, at 13°C, 2 h daily, for 10 days. Susceptibility to hypoxia (sSaO2 was determined as haemoglobin saturation slope during hypoxic test. Results . It was found that HVR and HCVR significantly increased and susceptibility to hypoxia (sSaO2 tended to decrease after cold acclimation. According to sSaO2 results before cold exposures, the group was divided into 3: Group 1 – with high susceptibility to hypoxia, Group 2 – medium and Group 3 – low susceptibility. Analysis of variances (MANOVA shows the key role of susceptibility to hypoxia and cold exposures and their interrelation. Posterior analysis (Fisher LSD showed significant difference in susceptibility to hypoxia between the groups prior to cold acclimation, while HVR and HCVR did not differ between the groups. After cold acclimation, susceptibility to hypoxia was not significantly different between the groups, while HCVR significantly increased in Groups 1 and 3, HVR significantly increased in Group 3 and HCVR, HVR did not change in Group 2. Conclusions . Short-term cold exposures caused an increase in functional reserves and improved oxygen supply of tissues in Group 1. Cold exposure hypoxia has caused energy loss in Group 3. Group 2 showed the most appropriate energy conservation reaction mode to cold exposures. No relation was found between

  8. Exposure to and recall of violence reduce short-term memory and cognitive control.

    Science.gov (United States)

    Bogliacino, Francesco; Grimalda, Gianluca; Ortoleva, Pietro; Ring, Patrick

    2017-08-08

    Previous research has investigated the effects of violence and warfare on individuals' well-being, mental health, and individual prosociality and risk aversion. This study establishes the short- and long-term effects of exposure to violence on short-term memory and aspects of cognitive control. Short-term memory is the ability to store information. Cognitive control is the capacity to exert inhibition, working memory, and cognitive flexibility. Both have been shown to affect positively individual well-being and societal development. We sampled Colombian civilians who were exposed either to urban violence or to warfare more than a decade earlier. We assessed exposure to violence through either the urban district-level homicide rate or self-reported measures. Before undertaking cognitive tests, a randomly selected subset of our sample was asked to recall emotions of anxiety and fear connected to experiences of violence, whereas the rest recalled joyful or emotionally neutral experiences. We found that higher exposure to violence was associated with lower short-term memory abilities and lower cognitive control in the group recalling experiences of violence, whereas it had no effect in the other group. This finding demonstrates that exposure to violence, even if a decade earlier, can hamper cognitive functions, but only among individuals actively recalling emotional states linked with such experiences. A laboratory experiment conducted in Germany aimed to separate the effect of recalling violent events from the effect of emotions of fear and anxiety. Both factors had significant negative effects on cognitive functions and appeared to be independent from each other.

  9. Toxicological effects of clofibric acid and diclofenac on plasma thyroid hormones of an Indian major carp, Cirrhinus mrigala during short and long-term exposures.

    Science.gov (United States)

    Saravanan, Manoharan; Hur, Jang-Hyun; Arul, Narayanasamy; Ramesh, Mathan

    2014-11-01

    In the present investigation, the toxicity of most commonly detected pharmaceuticals in the aquatic environment namely clofibric acid (CA) and diclofenac (DCF) was investigated in an Indian major carp Cirrhinus mrigala. Fingerlings of C. mrigala were exposed to different concentrations (1, 10 and 100μgL(-1)) of CA and DCF for a period of 96h (short term) and 35 days (long term). The toxic effects of CA and DCF on thyroid hormones (THs) such as thyroid stimulating hormone (TSH), thyroxine (T4) and triiodothyronine (T3) levels were evaluated. During the short and long-term exposure period TSH level was found to be decreased at all concentrations of CA (except at the end of 14(th) day in 1 and 10μgL(-l) and 21(st) day in 1μgL(-l)) whereas in DCF exposed fish TSH level was found to be increased when compared to control groups. T4 level was found to be decreased at 1 and 100μgL(-l) of CA exposure at the end of 96h. However, T4 level was decreased at all concentrations of CA and DCF during long-term (35 days) exposure period. Fish exposed to all concentrations of CA and DCF had lower level of T3 in both the treatments. These results suggest that both CA and DCF drugs induced significant changes (P<0.01 and P<0.05) on thyroid hormonal levels of C. mrigala. The alterations of these hormonal levels can be used as potential biomarkers in monitoring of pharmaceutical drugs in aquatic organisms. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Effects of day-time exposure to different light intensities on light-induced melatonin suppression at night.

    Science.gov (United States)

    Kozaki, Tomoaki; Kubokawa, Ayaka; Taketomi, Ryunosuke; Hatae, Keisuke

    2015-07-04

    Bright nocturnal light has been known to suppress melatonin secretion. However, bright light exposure during the day-time might reduce light-induced melatonin suppression (LIMS) at night. The effective proportion of day-time light to night-time light is unclear; however, only a few studies on accurately controlling both day- and night-time conditions have been conducted. This study aims to evaluate the effect of different day-time light intensities on LIMS. Twelve male subjects between the ages of 19 and 23 years (mean ± S.D., 20.8 ± 1.1) gave informed consent to participate in this study. They were exposed to various light conditions (day-time light conditions). They were then exposed to bright light (300 lx) again between 01:00 and 02:30 (night-time light exposure). They provided saliva samples before (00:55) and after night-time light exposure (02:30). A one-tailed paired t test yielded significant decrements of melatonin concentration after night-time light exposure under day-time dim, 100- and 300-lx light conditions. No significant differences exist in melatonin concentration between pre- and post-night-time light exposure under day-time 900- and 2700-lx light conditions. Present findings suggest the amount of light exposure needed to prevent LIMS caused by ordinary nocturnal light in individuals who have a general life rhythm (sleep/wake schedule). These findings may be useful in implementing artificial light environments for humans in, for example, hospitals and underground shopping malls.

  11. Determination of gamma-ray exposure rate from short-lived fission products under criticality accident conditions

    International Nuclear Information System (INIS)

    Yanagisawa, Hiroshi; Ohno, Akio; Aizawa, Eijyu

    2002-01-01

    For the assessment of γ-ray doses from short-lived fission products (FPs) under criticality accident conditions, γ-ray exposure rates varying with time were experimentally determined in the Transient Experiment Critical Facility (TRACY). The data were obtained by reactivity insertion in the range of 1.50 to 2.93$. It was clarified from the experiments that the contribution of γ-ray from short-lived FPs to total exposure during the experiments was evaluated to be 15 to 17%. Hence, the contribution cannot be neglected for the assessment of γ-ray doses under criticality accident conditions. Computational analyses also indicated that γ-ray exposure rates from short-lived FPs calculated with the Monte Carlo code, MCNP4B, and photon sources based on the latest FP decay data, the JENDL FP Decay Data File 2000, well agreed with the experimental results. The exposure rates were, however, extremely underestimated when the photon sources were obtained by the ORIGEN2 code. The underestimation is due to lack of energy-dependent photon emission data for major short-lived FP nuclides in the photon database attached to the ORIGEN2 code. It was also confirmed that the underestimation arose in 1,000 or less of time lapse after an initial power burst. (author)

  12. Morphological study of the effects of ozone on rat lung. I. Short-term exposure

    International Nuclear Information System (INIS)

    Hiroshima, K.; Kohno, T.; Owada, H.; Hayashi, Y.

    1987-01-01

    In order to determine the effects of ozone on lungs and the course of cell renewal after damage, young male rats were exposed to 3 ppm of ozone for 4 hr. They were killed at 1, 6, 12, and 18 hr and 1, 2, 3, 4, 7, and 14 days after exposure. One hour before the killing, dividing cells were labeled with tritiated thymidine. Type 1 cells of centriacinar location and bronchiolar cells were severely damaged after exposure. Labeling indices of type 2 cells and bronchiolar nonciliated cells increased 1 day after exposure. Hyperplasia of type 2 cells and bronchiolar nonciliated cells was observed 2 and 3 days after exposure. Ciligenesis of bronchiolar ciliated cells occurred 4 days after exposure. Our study shows that injured type 1 cells are repaired by proliferation of type 2 cells and that injured bronchiolar ciliated and Clara cells are repaired by proliferation of bronchiolar nonciliated cells. These undifferentiated cells are probably progenitors of ciliated cells and Clara cells, and some nonciliated cells are in a transitional form between nonciliated and type 2 cells

  13. Low level postnatal methylmercury exposure in vivo alters developmental forms of short-term synaptic plasticity in the visual cortex of rat

    International Nuclear Information System (INIS)

    Dasari, Sameera; Yuan, Yukun

    2009-01-01

    Methylmercury (MeHg) has been previously shown to affect neurotransmitter release. Short-term synaptic plasticity (STP) is primarily related to changes in the probability of neurotransmitter release. To determine if MeHg affects STP development, we examined STP forms in the visual cortex of rat following in vivo MeHg exposure. Neonatal rats received 0 (0.9% NaCl), 0.75 or 1.5 mg/kg/day MeHg subcutaneously for 15 or 30 days beginning on postnatal day 5, after which visual cortical slices were prepared for field potential recordings. In slices prepared from rats treated with vehicle, field excitatory postsynaptic potentials (fEPSPs) evoked by paired-pulse stimulation at 20-200 ms inter-stimulus intervals showed a depression (PPD) of the second fEPSP (fEPSP2). PPD was also seen in slices prepared from rats after 15 day treatment with 0.75 or 1.5 mg/kg/day MeHg. However, longer duration treatment (30 days) with either dose of MeHg resulted in paired-pulse facilitation (PPF) of fEPSP2 in the majority of slices examined. PPF remained observable in slices prepared from animals in which MeHg exposure had been terminated for 30 days after completion of the initial 30 day MeHg treatment, whereas slices from control animals still showed PPD. MeHg did not cause any frequency- or region-preferential effect on STP. Manipulations of [Ca 2+ ] e or application of the GABA A receptor antagonist bicuculline could alter the strength and polarity of MeHg-induced changes in STP. Thus, these data suggest that low level postnatal MeHg exposure interferes with the developmental transformation of STP in the visual cortex, which is a long-lasting effect.

  14. Day napping and short night sleeping are associated with higher risk of diabetes in older adults.

    Science.gov (United States)

    Xu, Qun; Song, Yiqing; Hollenbeck, Albert; Blair, Aaron; Schatzkin, Arthur; Chen, Honglei

    2010-01-01

    To examine whether day napping or short night sleeping is associated with higher risk of diabetes. This was a prospective study of hours of day napping and night sleeping assessed in 1996-1997 in relation to diabetes diagnosed between 2000 and 2006 (n = 10,143) among 174,542 participants in the National Institutes of Health (NIH)-AARP Diet and Health Study. Odds ratios (ORs) and 95% CI were derived from multivariate logistic regression models. Longer day napping was associated with a higher risk of diabetes. After adjustment for potential confounders, ORs were 1.23 (95% CI 1.18-1.29) for those reporting or =1 h of napping compared with individuals who did not nap (P(trend) or =9 h. In both analyses, additional adjustment for BMI only modestly attenuated the associations. Further analysis showed a statistically significant interaction between hours of napping and sleeping on diabetes (P(interaction) napping, only short night sleeping was associated with higher occurrence of diabetes, whereas among those with > or =1 h of napping, both long and short sleeping was associated with higher risk. Day napping and short night sleeping are associated with higher risk of diabetes. The association between sleep duration and diabetes may be modified by napping habit.

  15. PHOTOPERIODIC HISTORY AFFECTS THE CRITICAL DAYLENGTH OF THE SHORT-DAY PLANT ACROSYMPHYTON-PURPURIFERUM (RHODOPHYTA)

    NARCIS (Netherlands)

    BREEMAN, AM

    The crustose tetrasporophyte of the red alga Acrosymphyton purpuriferum is a qualitative short-day plant in the formation of its tetrasporangia. The critical daylength for the response was determined in plants precultured in various long-day regimes [20:4, 18:6, 16:8 and 14:10 (L:D, h)]. There was a

  16. Short-Term Exposure to Ambient Air Pollution and Biomarkers of Systemic Inflammation: The Framingham Heart Study.

    Science.gov (United States)

    Li, Wenyuan; Dorans, Kirsten S; Wilker, Elissa H; Rice, Mary B; Ljungman, Petter L; Schwartz, Joel D; Coull, Brent A; Koutrakis, Petros; Gold, Diane R; Keaney, John F; Vasan, Ramachandran S; Benjamin, Emelia J; Mittleman, Murray A

    2017-09-01

    The objective of this study is to examine associations between short-term exposure to ambient air pollution and circulating biomarkers of systemic inflammation in participants from the Framingham Offspring and Third Generation cohorts in the greater Boston area. We included 3996 noncurrent smoking participants (mean age, 53.6 years; 54% women) who lived within 50 km from a central air pollution monitoring site in Boston, MA, and calculated the 1- to 7-day moving averages of fine particulate matter (diameterpollution was associated with higher levels of C-reactive protein, interleukin-6, and tumor necrosis factor receptor 2 but not fibrinogen or tumor necrosis factor α in individuals residing in the greater Boston area. © 2017 American Heart Association, Inc.

  17. Short-term environmental enrichment exposure induces proliferation and maturation of doublecortin-positive cells in the prefrontal cortex

    Science.gov (United States)

    Fan, Chunling; Zhang, Mengqi; Shang, Lei; Cynthia, Ngobe Akume; Li, Zhi; Yang, Zhenyu; Chen, Dan; Huang, Jufang; Xiong, Kun

    2014-01-01

    Previous studies have demonstrated that doublecortin-positive immature neurons exist predominantly in the superficial layer of the cerebral cortex of adult mammals such as guinea pigs, and these neurons exhibit very weak properties of self-proliferation during adulthood under physiological conditions. To verify whether environmental enrichment has an impact on the proliferation and maturation of these immature neurons in the prefrontal cortex of adult guinea pigs, healthy adult guinea pigs were subjected to short-term environmental enrichment. Animals were allowed to play with various cognitive and physical stimulating objects over a period of 2 weeks, twice per day, for 60 minutes each. Immunofluorescence staining results indicated that the number of doublecortin-positive cells in layer II of the prefrontal cortex was significantly increased after short-term environmental enrichment exposure. In addition, these doublecortin-positive cells co-expressed 5-bromo-2-deoxyuridine (a marker of cell proliferation), c-Fos (a marker of cell viability) and NeuN (a marker of mature neurons). Experimental findings showed that short-term environmental enrichment can induce proliferation, activation and maturation of doublecortin-positive cells in layer II of the prefrontal cortex of adult guinea pigs. PMID:25206818

  18. Dark Matter Results from 54-Ton-Day Exposure of PandaX-II Experiment

    Science.gov (United States)

    Cui, Xiangyi; Abdukerim, Abdusalam; Chen, Wei; Chen, Xun; Chen, Yunhua; Dong, Binbin; Fang, Deqing; Fu, Changbo; Giboni, Karl; Giuliani, Franco; Gu, Linhui; Gu, Yikun; Guo, Xuyuan; Guo, Zhifan; Han, Ke; He, Changda; Huang, Di; He, Shengming; Huang, Xingtao; Huang, Zhou; Ji, Xiangdong; Ju, Yonglin; Li, Shaoli; Li, Yao; Lin, Heng; Liu, Huaxuan; Liu, Jianglai; Ma, Yugang; Mao, Yajun; Ni, Kaixiang; Ning, Jinhua; Ren, Xiangxiang; Shi, Fang; Tan, Andi; Wang, Cheng; Wang, Hongwei; Wang, Meng; Wang, Qiuhong; Wang, Siguang; Wang, Xiuli; Wang, Xuming; Wu, Qinyu; Wu, Shiyong; Xiao, Mengjiao; Xie, Pengwei; Yan, Binbin; Yang, Yong; Yue, Jianfeng; Zhang, Dan; Zhang, Hongguang; Zhang, Tao; Zhang, Tianqi; Zhao, Li; Zhou, Jifang; Zhou, Ning; Zhou, Xiaopeng; PandaX-II Collaboration

    2017-11-01

    We report a new search for weakly interacting massive particles (WIMPs) using the combined low background data sets acquired in 2016 and 2017 from the PandaX-II experiment in China. The latest data set contains a new exposure of 77.1 live days, with the background reduced to a level of 0.8 ×10-3 evt /kg /day , improved by a factor of 2.5 in comparison to the previous run in 2016. No excess events are found above the expected background. With a total exposure of 5.4 ×104 kg day , the most stringent upper limit on the spin-independent WIMP-nucleon cross section is set for a WIMP with mass larger than 100 GeV /c2 , with the lowest 90% C.L. exclusion at 8.6 ×10-47 cm2 at 40 GeV /c2 .

  19. Effects of Short Term Exposure of Atrazine on the Liver and Kidney of Normal and Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Dinesh Babu Jestadi

    2014-01-01

    Full Text Available The present study evaluates the effects of short term (15 days exposure of low dose (300 μg kg−1 of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine on antioxidant status and markers of liver and kidney damage in normal (nondiabetic and diabetic male Wistar rats. Rats were divided into four groups: Group I as normal control, Group II as atrazine treated, Group III as diabetic control, and Group IV as atrazine treated diabetic rats. Atrazine administration resulted in increased MDA concentration as well as increased activities of SOD, CAT, and GPx in both liver and kidney of atrazine treated and atrazine treated diabetic rats. However, GSH level was decreased in both liver and kidney of atrazine treated and atrazine treated diabetic rats. Atrazine administration led to significant increase in liver damage biomarkers such as AST, ALT, and ALP as well as kidney damage biomarkers such as creatinine and urea in both normal and diabetic rats, but this increase was more pronounced in diabetic rats when compared to normal rats. In conclusion, the results of the present study demonstrate that short term exposure of atrazine at a dose of 300 μg kg−1 could potentially induce oxidative damage in liver and kidney of both normal and diabetic rats.

  20. Short-day treatment alters Douglas-fir seedling dehardening and transplant root proliferation at varying rhizosphere temperatures

    Science.gov (United States)

    Douglass F. Jacobs; Anthony S. Davis; BArrett C. Wilson; R. Kasten Dumroese; Rosa C. Goodman; K. Francis Salifu

    2008-01-01

    We tested effects of shortened day length during nursery culture on Douglis-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) seedling development at dormancy release. Seedlings from a 42 N source were grown either under ambient photoperiods (long-day (LD)) or with a 28 day period of 9 h light: 15 h dark photoperiods (short...

  1. Evaluation of the fate and pathological response in the lung and pleura of brake dust alone and in combination with added chrysotile compared to crocidolite asbestos following short-term inhalation exposure.

    Science.gov (United States)

    Bernstein, D M; Rogers, R A; Sepulveda, R; Kunzendorf, P; Bellmann, B; Ernst, H; Creutzenberg, O; Phillips, J I

    2015-02-15

    This study was designed to provide an understanding of the biokinetics and potential toxicology in the lung and pleura following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake-dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6h/day for 5 days to either brake-dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake-dust or crocidolite asbestos. The chrysotile fibers were relatively biosoluble whereas the crocidolite asbestos fibers persisted through the life-time of the animal. This was reflected in the lung and the pleura where no significant pathological response was observed at any time point in the brake dust or chrysotile/brake dust exposure groups through 365 days post exposure. In contrast, crocidolite asbestos produced a rapid inflammatory response in the lung parenchyma and the pleura, inducing a significant increase in fibrotic response in both of these compartments. Crocidolite fibers were observed embedded in the diaphragm with activated mesothelial cells immediately after cessation of exposure. While no chrysotile fibers were found in the mediastinal lymph nodes, crocidolite fibers of up to 35 μm were observed. These results provide support that brake-dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung or the pleural cavity following short term inhalation. Copyright © 2014. Published by Elsevier Inc.

  2. Moderate Maternal Alcohol Exposure on Gestational Day 12 Impacts Anxiety-Like Behavior in Offspring

    OpenAIRE

    Rouzer, Siara K.; Cole, Jesse M.; Johnson, Julia M.; Varlinskaya, Elena I.; Diaz, Marvin R.

    2017-01-01

    Among the numerous consequences of prenatal alcohol exposure (PAE) is an increase in anxiety-like behavior that can prove debilitating to daily functioning. A significant body of literature has linked gestational day 12 (G12) heavy ethanol exposure with social anxiety, evident in adolescent males and females. However, the association between non-social anxiety-like behavior and moderate alcohol exposure, a more common pattern of drinking in pregnant women, is yet unidentified. To model modera...

  3. Chronic methamphetamine exposure produces a delayed, long-lasting memory deficit.

    Science.gov (United States)

    North, Ashley; Swant, Jarod; Salvatore, Michael F; Gamble-George, Joyonna; Prins, Petra; Butler, Brittany; Mittal, Mukul K; Heltsley, Rebecca; Clark, John T; Khoshbouei, Habibeh

    2013-05-01

    Methamphetamine (METH) is a highly addictive and neurotoxic psychostimulant. Its use in humans is often associated with neurocognitive impairment. Whether this is due to long-term deficits in short-term memory and/or hippocampal plasticity remains unclear. Recently, we reported that METH increases baseline synaptic transmission and reduces LTP in an ex vivo preparation of the hippocampal CA1 region from young mice. In the current study, we tested the hypothesis that a repeated neurotoxic regimen of METH exposure in adolescent mice decreases hippocampal synaptic plasticity and produces a deficit in short-term memory. Contrary to our prediction, there was no change in the hippocampal plasticity or short-term memory when measured after 14 days of METH exposure. However, we found that at 7, 14, and 21 days of drug abstinence, METH-exposed mice exhibited a deficit in spatial memory, which was accompanied by a decrease in hippocampal plasticity. Our results support the interpretation that the deleterious cognitive consequences of neurotoxic levels of METH exposure may manifest and persist after drug abstinence. Therefore, therapeutic strategies should consider short-term as well as long-term consequences of methamphetamine exposure. Copyright © 2012 Wiley Periodicals, Inc.

  4. Exercise during Short-Term and Long-Term Continuous Exposure to Hypoxia Exacerbates Sleep-Related Periodic Breathing

    Science.gov (United States)

    Tellez, Helio Fernandez; Morrison, Shawnda A.; Neyt, Xavier; Mairesse, Olivier; Piacentini, Maria Francesca; Macdonald-Nethercott, Eoin; Pangerc, Andrej; Dolenc-Groselj, Leja; Eiken, Ola; Pattyn, Nathalie; Mekjavic, Igor B.; Meeusen, Romain

    2016-01-01

    Study Objectives: Exposure to hypoxia elevates chemosensitivity, which can lead to periodic breathing. Exercise impacts gas exchange, altering chemosensitivity; however, interactions between sleep, exercise and chronic hypoxic exposure have not been examined. This study investigated whether exercise exacerbates sleep-related periodic breathing in hypoxia. Methods: Two experimental phases. Short-Term Phase: a laboratory controlled, group-design study in which 16 active, healthy men (age: 25 ± 3 y, height: 1.79 ± 0.06 m, mass: 74 ± 8 kg) were confined to a normobaric hypoxic environment (FIO2 = 0.139 ± 0.003, 4,000 m) for 10 days, after random assignment to a sedentary (control, CON) or cycle-exercise group (EX). Long-Term Phase: conducted at the Concordia Antarctic Research Station (3,800 m equivalent at the Equator) where 14 men (age: 36 ± 9 y, height: 1.77 ± 0.09 m, mass: 75 ± 10 kg) lived for 12–14 months, continuously confined. Participants were stratified post hoc based on self-reported physical activity levels. We quantified apnea-hypopnea index (AHI) and physical activity variables. Results: Short-Term Phase: mean AHI scores were significantly elevated in the EX group compared to CON (Night1 = CON: 39 ± 51, EX: 91 ± 59; Night10 = CON: 32 ± 32, EX: 92 ± 48; P = 0.046). Long-Term Phase: AHI was correlated to mean exercise time (R2 = 0.4857; P = 0.008) and the coefficient of variation in night oxyhemoglobin saturation (SpO2; R2 = 0.3062; P = 0.049). Conclusions: Data indicate that exercise (physical activity) per se affects night SpO2 concentrations and AHI after a minimum of two bouts of moderate-intensity hypoxic exercise, while habitual physical activity in hypobaric hypoxic confinement affects breathing during sleep, up to 13+ months' duration Citation: Tellez HF, Morrison SA, Neyt X, Mairesse O, Piacentini MF, Macdonald-Nethercott E, Pangerc A, Dolenc-Groselj L, Eiken O, Pattyn N, Mekjavic IB, Meeusen R. Exercise during short-term and long

  5. Cytokines related to three major types of cell-mediated immunity in short- and long-term exposures to lead compounds.

    Science.gov (United States)

    Dobrakowski, Michał; Boroń, Marta; Czuba, Zenon P; Kasperczyk, Aleksandra; Machoń-Grecka, Anna; Kasperczyk, Sławomir

    2016-11-01

    Many investigators have posited on the significant influence of lead on the immune system function. However, available data on this topic are not conclusive. Therefore, a study was undertaken to examine associations between lead exposure and levels of cytokines related to the T-helper (T H )-1, T H 2, and T H 17 types of immune response in humans. For these analyses, three population groups were examined: the first consisted of male workers exposed to lead for a short period of time (36-44 days); the second included male workers chronically exposed to lead (13 ± 10 years); and a control group that was composed of male administrative workers with blood lead levels (BLL) immune responses, while chronic exposure modifies their levels. Taken together, these modifications do not evidence an ability of lead to promote specifically one type of immune response in an exposed host.

  6. An evaluation of short-term exposures of brake mechanics to asbestos during automotive and truck brake cleaning and machining activities.

    Science.gov (United States)

    Richter, Richard O; Finley, Brent L; Paustenbach, Dennis J; Williams, Pamela R D; Sheehan, Patrick J

    2009-07-01

    Historically, the greatest contributions to airborne asbestos concentrations during brake repair work were likely due to specific, short-duration, dust-generating activities. In this paper, the available short-term asbestos air sampling data for mechanics collected during the cleaning and machining of vehicle brakes are evaluated to determine their impact on both short-term and daily exposures. The high degree of variability and lack of transparency for most of the short-term samples limit their use in reconstructing past asbestos exposures for brake mechanics. However, the data are useful in evaluating how reducing short-term, dust-generating activities reduced long-term exposures, especially for auto brake mechanics. Using the short-term dose data for grinding brake linings from these same studies, in combination with existing time-weighted average (TWA) data collected in decades after grinding was commonplace in rebuilding brake shoes, an average 8-h TWA of approximately 0.10 f/cc was estimated for auto brake mechanics that performed arc grinding of linings during automobile brake repair (in the 1960s or earlier). In the 1970s and early 1980s, a decline in machining activities led to a decrease in the 8-h TWA to approximately 0.063 f/cc. Improved cleaning methods in the late 1980s further reduced the 8-h TWA for most brake mechanics to about 0.0021 f/cc. It is noteworthy that when compared with the original OSHA excursion level, only 15 of the more than 300 short-term concentrations for brake mechanics measured during the 1970s and 1980s possibly exceeded the standard. Considering exposure duration, none of the short-term exposures were above the current OSHA excursion level.

  7. Risk of Adverse Pregnancy Outcome After Paternal Exposure to Methotrexate Within 90 Days Before Pregnancy

    DEFF Research Database (Denmark)

    Eck, Lasse Karlsen; Jensen, Thomas Bo; Mastrogiannis, Dimitrios

    2017-01-01

    OBJECTIVE: To study the association between paternal exposure to methotrexate within the 90-day period before pregnancy and congenital malformations and stillbirth in the offspring. METHODS: We conducted a nationwide register study. Our cohort consisted of all live births in Denmark between 1997...... group and no increased risk of preterm birth (adjusted OR 1.31, 95% CI 0.66-2.59) among the children from exposed fathers. CONCLUSION: We found no association between paternal exposure to methotrexate within 90 days before pregnancy and congenital malformations, stillbirths, or preterm birth. Available...

  8. Within-day variability on short and long walking tests in persons with multiple sclerosis.

    Science.gov (United States)

    Feys, Peter; Bibby, Bo; Romberg, Anders; Santoyo, Carme; Gebara, Benoit; de Noordhout, Benoit Maertens; Knuts, Kathy; Bethoux, Francois; Skjerbæk, Anders; Jensen, Ellen; Baert, Ilse; Vaney, Claude; de Groot, Vincent; Dalgas, Ulrik

    2014-03-15

    To compare within-day variability of short (10 m walking test at usual and fastest speed; 10MWT) and long (2 and 6-minute walking test; 2MWT/6MWT) tests in persons with multiple sclerosis. Observational study. MS rehabilitation and research centers in Europe and US within RIMS (European network for best practice and research in MS rehabilitation). Ambulatory persons with MS (Expanded Disability Status Scale 0-6.5). Subjects of different centers performed walking tests at 3 time points during a single day. 10MWT, 2MWT and 6MWT at fastest speed and 10MWT at usual speed. Ninety-five percent limits of agreement were computed using a random effects model with individual pwMS as random effect. Following this model, retest scores are with 95% certainty within these limits of baseline scores. In 102 subjects, within-day variability was constant in absolute units for the 10MWT, 2MWT and 6MWT at fastest speed (+/-0.26, 0.16 and 0.15m/s respectively, corresponding to +/-19.2m and +/-54 m for the 2MWT and 6MWT) independent on the severity of ambulatory dysfunction. This implies a greater relative variability with increasing disability level, often above 20% depending on the applied test. The relative within-day variability of the 10MWT at usual speed was +/-31% independent of ambulatory function. Absolute values of within-day variability on walking tests at fastest speed were independent of disability level and greater with short compared to long walking tests. Relative within-day variability remained overall constant when measured at usual speed. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  9. Short-term exposure to a synthetic estrogen disrupts mating dynamics in a pipefish.

    Science.gov (United States)

    Partridge, Charlyn; Boettcher, Anne; Jones, Adam G

    2010-11-01

    Sexual selection is responsible for the evolution of some of the most elaborate traits occurring in nature, many of which play a vital role in competition over access to mates and individual reproductive fitness. Because expression of these traits is typically regulated by sex-steroids there is a significant potential for their expression to be affected by the presence of certain pollutants, such as endocrine disrupting compounds. Endocrine disruptors have been shown to alter primary sexual traits and impact reproduction, but few studies have investigated how these compounds affect secondary sexual trait expression and how that may, in turn, impact mating dynamics. In this study we examine how short-term exposure to a synthetic estrogen impacts secondary sexual trait expression and mating dynamics in the Gulf pipefish, a species displaying sex-role reversal. Our results show that only 10days of exposure to 17α-ethinylestradiol results in adult male pipefish developing female-like secondary sexual traits. While these males are capable of reproduction, females discriminate against exposed males in mate choice trials. In natural populations, this type of discrimination would reduce male mating opportunities, thus potentially reducing their long-term reproductive success. Importantly, the effects of these compounds on mating dynamics and mating opportunity would not be observed using the current standard methods of assessing environmental contamination. However, disrupting these processes could have profound effects on the viability of exposed populations. Copyright © 2010 Elsevier Inc. All rights reserved.

  10. Exhaled carbon monoxide: a non-invasive biomarker of short-term exposure to outdoor air pollution

    Directory of Open Access Journals (Sweden)

    Herve Lawin

    2017-04-01

    Full Text Available Abstract Background In urban settings of Africa with rapidly increasing population, traffic-related air pollution is a major contributor to outdoor air pollution (OAP. Although OAP has been identified as a leading cause of global morbidity and mortality, there is however, lack of a simple biomarker to assess levels of exposure to OAP in resource-poor settings. This study evaluated the role of exhaled carbon monoxide (exhCO as a potential biomarker of exposure to ambient carbon monoxide (ambCO from OAP. Methods This was a descriptive study conducted among male commercial motorcycle riders in Cotonou – the economic capital of Benin. The participants’ AmbCO was measured using a portable carbon monoxide (CO data logger for 8 h during the period of their shift. ExhCO was measured just before and immediately after their shift (8-h Participants were asked not to cook or to smoke during the day of the measurements. Linear regression analysis was used to assess the association between ambCO and exhCO for the last 2, 4 and 6 h of their shift. Results Of 170 participants who completed the study, their mean ± SD age was 42.2 ± 8.4 years, and their mean ± SD daily income was 7.3 ± 2.7$. Also, 95% of the participants’ used solid fuels for cooking and only 2% had ever smoked. Average exhCO increased by 5.1 ppm at the end of the shift (p = 0.004. Post-shift exhCO was significantly associated to ambCO, this association was strongest for the last 2 h of OAP exposure before exhCO measurement (β = 0.34, p < 0.001. Conclusion ExhCO level was associated with recent exposure to ambCO from OAP with measurable increase after 8 h of exposure. These findings suggest that ExhCO may be a potential biomarker of short-term exposure to OAP.

  11. High-resolution short-exposure small-animal laboratory x-ray phase-contrast tomography

    Science.gov (United States)

    Larsson, Daniel H.; Vågberg, William; Yaroshenko, Andre; Yildirim, Ali Önder; Hertz, Hans M.

    2016-12-01

    X-ray computed tomography of small animals and their organs is an essential tool in basic and preclinical biomedical research. In both phase-contrast and absorption tomography high spatial resolution and short exposure times are of key importance. However, the observable spatial resolutions and achievable exposure times are presently limited by system parameters rather than more fundamental constraints like, e.g., dose. Here we demonstrate laboratory tomography with few-ten μm spatial resolution and few-minute exposure time at an acceptable dose for small-animal imaging, both with absorption contrast and phase contrast. The method relies on a magnifying imaging scheme in combination with a high-power small-spot liquid-metal-jet electron-impact source. The tomographic imaging is demonstrated on intact mouse, phantoms and excised lungs, both healthy and with pulmonary emphysema.

  12. Assessment of every day extremely low frequency (Elf) electromagnetic fields (50-60 Hz) exposure: which metrics?

    International Nuclear Information System (INIS)

    Verrier, A.; Magne, I.; Souqes, M.; Lambrozo, J.

    2006-01-01

    Because electricity is encountered at every moment of the day, at home with household appliances, or in every type of transportation, people are most of the time exposed to extremely low frequency (E.L.F.) electromagnetic fields (50-60 Hz) in a various way. Due to a lack of knowledge about the biological mechanisms of 50 Hz magnetic fields, studies seeking to identify health effects of exposure use central tendency metrics. The objective of our study is to provide better information about these exposure measurements from three categories of metrics. We calculated metrics of exposure measurements from data series (79 very day exposed subjects), made up approximately 20,000 recordings of magnetic fields, measured every 30 seconds for 7 days with an E.M.D.E.X. II dosimeter. These indicators were divided into three categories : central tendency metrics, dispersion metrics and variability metrics.We use Principal Component Analysis, a multidimensional technique to examine the relations between different exposure metrics for a group of subjects. Principal component Analysis (P.C.A.) enabled us to identify from the foreground 71.7% of the variance. The first component (42.7%) was characterized by central tendency; the second (29.0%) was composed of dispersion characteristics. The third component (17.2%) was composed of variability characteristics. This study confirm the need to improve exposure measurements by using at least two dimensions intensity and dispersion. (authors)

  13. Short-term use of serotonin reuptake inhibitors and risk of upper gastrointestinal bleeding.

    Science.gov (United States)

    Wang, Yen-Po; Chen, Yung-Tai; Tsai, Chia-Fen; Li, Szu-Yuan; Luo, Jiing-Chyuan; Wang, Shuu-Jiun; Tang, Chao-Hsiun; Liu, Chia-Jen; Lin, Han-Chieh; Lee, Fa-Yauh; Chang, Full-Young; Lu, Ching-Liang

    2014-01-01

    The association between selective serotonin receptor inhibitors (SSRIs) and risk of upper gastrointestinal bleeding remains controversial. Previous studies have generally evaluated the issue for approximately 3 months, even though the SSRI-mediated inhibition of platelet serotonin concentrations occurs within 7-14 days. The authors explored the risk of upper gastrointestinal bleeding after short-term SSRI exposure by a case-crossover design. The records of psychiatric inpatients with upper gastrointestinal bleeding were retrieved from the Taiwan National Health Insurance Database (1998-2009). Rates of antidepressant use were compared for case and control periods with time windows of 7, 14, and 28 days. The adjusted self-matched odds ratios from a conditional logistic regression model were used to determine the association between SSRI use and upper gastrointestinal bleeding. A total of 5,377 patients with upper gastrointestinal bleeding were enrolled. The adjusted odds ratio for the risk of upper gastrointestinal bleeding after SSRI exposure was 1.67 (95% CI=1.23-2.26) for the 7-day window, 1.84 (95% CI=1.42-2.40) for the 14-day window, and 1.67 (95% CI=1.34-2.08) for the 28-day window. SSRIs with high and intermediate, but not low, affinity for serotonin transporter were associated with upper gastrointestinal bleeding. An elevated risk of upper gastrointestinal bleeding after SSRI exposure was seen in male but not female patients. Short-term SSRI use (7-28 days) is significantly associated with upper gastrointestinal bleeding. Gender differences may exist in the relationship between SSRI use and upper gastrointestinal bleeding. Physicians should carefully monitor signs of upper gastrointestinal bleeding even after short-term exposure to SSRIs, as is done with nonsteroidal anti-inflammatory drugs and aspirin.

  14. Framework for human health risk assessment of non-cancer effects resulting from short-duration and intermittent exposures to chemicals.

    Science.gov (United States)

    Haber, Lynne T; Sandhu, Reena; Li-Muller, Angela; Mohapatra, Asish; Petrovic, Sanya; Meek, M E Bette

    2016-09-01

    Durations of exposure to chemicals, whether for single, repeated or intermittent periods, may vary from those upon which most guidance values are normally based. Because it is presently not feasible to conduct toxicity studies or develop toxicity reference values (TRVs) specific to each scenario of interest, methods are needed to address these various durations, drawing as much as possible on existing TRVs. A working framework was developed to address the potential for non-cancer effects resulting from continuous short-duration and intermittent exposures to chemicals. The framework presents an integrated, tiered approach that assists the user in identifying when existing TRVs can be applied directly, and the adaptations needed to assess the acceptability of short-duration or intermittent exposure scenarios. Descriptions of when and how toxicokinetic and toxicodynamic aspects need to be taken into consideration are also presented. The framework incorporates the use of TRVs based on exposure periods as similar as possible to the "actual" exposure periods and application of dose averaging under limited, specified conditions. This framework has been developed to aid in improving the scientific basis for the evaluation of short-duration and intermittent exposures in a variety of settings. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Within-day variability on short and long walking tests in persons with multiple sclerosis

    NARCIS (Netherlands)

    Feys, P.; Bibby, B.; Romberg, A.; Santoyo, C.; Gebara, B.; de Noordhout, B.M.; Knuts, K.; Bethoux, F.; Skjerbaek, A.; Jensen, E.; Baert, I.; Vaney, C.; de Groot, V.; Dalgas, U.

    2014-01-01

    Objective To compare within-day variability of short (10 m walking test at usual and fastest speed; 10MWT) and long (2 and 6-minute walking test; 2MWT/6MWT) tests in persons with multiple sclerosis. Design Observational study. Setting MS rehabilitation and research centers in Europe and US within

  16. Dose–response assessment of nephrotoxicity from a twenty-eight-day combined-exposure to melamine and cyanuric acid in F344 rats

    Energy Technology Data Exchange (ETDEWEB)

    Gamboa da Costa, Gonçalo, E-mail: goncalo.gamboa@fda.hhs.gov [Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR 72079 (United States); Jacob, Cristina C.; Von Tungeln, Linda S. [Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR 72079 (United States); Hasbrouck, Nicholas R. [Center for Veterinary Medicine, Laurel, MD 20708 (United States); Olson, Greg R. [Toxicologic Pathology Associates, Jefferson, AR 72079 (United States); Hattan, David G. [Center for Food Safety and Applied Nutrition, College Park, MD 20740 (United States); Reimschuessel, Renate [Center for Veterinary Medicine, Laurel, MD 20708 (United States); Beland, Frederick A. [Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR 72079 (United States)

    2012-07-15

    The adulteration of pet food with melamine and derivatives, including cyanuric acid, has been implicated in the kidney failure and death of cats and dogs in the USA and other countries. In a previous 7-day dietary study in F344 rats, we established a no-observed-adverse-effect level (NOAEL) for a co-exposure to melamine and cyanuric acid of 8.6 mg/kg bw/day of each compound, and a benchmark dose lower confidence limit (BMDL) of 8.4–10.9 mg/kg bw/day of each compound. To ascertain the role played by the duration of exposure, we treated F344 rats for 28 days. Groups of male and female rats were fed diet containing 0 (control), 30, 60, 120, 180, 240, or 360 ppm of both melamine and cyanuric acid. The lowest dose that produced histopathological alterations in the kidney was 120 ppm, versus 229 ppm in the 7-day study. Wet-mount analysis of kidney sections demonstrated the formation of melamine cyanurate spherulites in one male and two female rats at the 60 ppm dose and in one female rat at the 30 ppm dose, establishing a NOAEL of 2.1 mg/kg bw/day for males and < 2.6 mg/kg bw/day for females, and BMDL values as low as 1.6 mg/kg bw/day for both sexes. These data demonstrate that the length of exposure is an important component in the threshold of toxicity from a co-exposure to these compounds and suggest that the current risk assessments based on exposures to melamine alone may not reflect sufficiently the risk of a co-exposure to melamine and cyanuric acid. -- Highlights: ► A 28-day dietary co-exposure to melamine and cyanuric acid was conducted in F344 rats. ► The NOAELs were 2.1 mg/kg bw/day for males and < 2.6 mg/kg bw/day for females. ► BMDL values as low as 1.6 mg/kg bw/day for both sexes were determined. ► The length of exposure plays an important role in the threshold of toxicity. ► Current assessments may underestimate the risk of melamine and cyanuric acid.

  17. Dose–response assessment of nephrotoxicity from a twenty-eight-day combined-exposure to melamine and cyanuric acid in F344 rats

    International Nuclear Information System (INIS)

    Gamboa da Costa, Gonçalo; Jacob, Cristina C.; Von Tungeln, Linda S.; Hasbrouck, Nicholas R.; Olson, Greg R.; Hattan, David G.; Reimschuessel, Renate; Beland, Frederick A.

    2012-01-01

    The adulteration of pet food with melamine and derivatives, including cyanuric acid, has been implicated in the kidney failure and death of cats and dogs in the USA and other countries. In a previous 7-day dietary study in F344 rats, we established a no-observed-adverse-effect level (NOAEL) for a co-exposure to melamine and cyanuric acid of 8.6 mg/kg bw/day of each compound, and a benchmark dose lower confidence limit (BMDL) of 8.4–10.9 mg/kg bw/day of each compound. To ascertain the role played by the duration of exposure, we treated F344 rats for 28 days. Groups of male and female rats were fed diet containing 0 (control), 30, 60, 120, 180, 240, or 360 ppm of both melamine and cyanuric acid. The lowest dose that produced histopathological alterations in the kidney was 120 ppm, versus 229 ppm in the 7-day study. Wet-mount analysis of kidney sections demonstrated the formation of melamine cyanurate spherulites in one male and two female rats at the 60 ppm dose and in one female rat at the 30 ppm dose, establishing a NOAEL of 2.1 mg/kg bw/day for males and < 2.6 mg/kg bw/day for females, and BMDL values as low as 1.6 mg/kg bw/day for both sexes. These data demonstrate that the length of exposure is an important component in the threshold of toxicity from a co-exposure to these compounds and suggest that the current risk assessments based on exposures to melamine alone may not reflect sufficiently the risk of a co-exposure to melamine and cyanuric acid. -- Highlights: ► A 28-day dietary co-exposure to melamine and cyanuric acid was conducted in F344 rats. ► The NOAELs were 2.1 mg/kg bw/day for males and < 2.6 mg/kg bw/day for females. ► BMDL values as low as 1.6 mg/kg bw/day for both sexes were determined. ► The length of exposure plays an important role in the threshold of toxicity. ► Current assessments may underestimate the risk of melamine and cyanuric acid.

  18. Long-Term Impairment of Sound Processing in the Auditory Midbrain by Daily Short-Term Exposure to Moderate Noise

    Directory of Open Access Journals (Sweden)

    Liang Cheng

    2017-01-01

    Full Text Available Most citizen people are exposed daily to environmental noise at moderate levels with a short duration. The aim of the present study was to determine the effects of daily short-term exposure to moderate noise on sound level processing in the auditory midbrain. Sound processing properties of auditory midbrain neurons were recorded in anesthetized mice exposed to moderate noise (80 dB SPL, 2 h/d for 6 weeks and were compared with those from age-matched controls. Neurons in exposed mice had a higher minimum threshold and maximum response intensity, a longer first spike latency, and a higher slope and narrower dynamic range for rate level function. However, these observed changes were greater in neurons with the best frequency within the noise exposure frequency range compared with those outside the frequency range. These sound processing properties also remained abnormal after a 12-week period of recovery in a quiet laboratory environment after completion of noise exposure. In conclusion, even daily short-term exposure to moderate noise can cause long-term impairment of sound level processing in a frequency-specific manner in auditory midbrain neurons.

  19. Subcellular partitioning of cadmium in the freshwater bivalve, Pyganodon grandis, after separate short-term exposures to waterborne or diet-borne metal

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Sophie; Hare, Landis [INRS-Eau, Terre et Environnement, Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada); Campbell, Peter G.C., E-mail: peter.campbell@ete.inrs.ca [INRS-Eau, Terre et Environnement, Universite du Quebec, 490 rue de la Couronne, Quebec, QC, G1K 9A9 (Canada)

    2010-11-15

    The dynamics of cadmium uptake and subcellular partitioning were studied in laboratory experiments conducted on Pyganodon grandis, a freshwater unionid bivalve that shows promise as a biomonitor for metal pollution. Bivalves were collected from an uncontaminated lake, allowed to acclimate to laboratory conditions ({>=}25 days), and then either exposed to a low, environmentally relevant, concentration of dissolved Cd (5 nM; 6, 12 and 24 h), or fed Cd-contaminated algae ({approx}70 nmol Cd g{sup -1} dry weight; 4 x 4 h). In this latter case, the bivalves were allowed to depurate for up to 8 days after the end of the feeding phase. As anticipated, the gills were the main target organ during the aqueous Cd exposure whereas the intestine was the initial site of Cd accumulation during the dietary exposure; during the subsequent depuration period, the dietary Cd accumulated in both the digestive gland and in the gills. For the gills, the distribution of Cd among the subcellular fractions (i.e., granules > heat-denatured proteins (HDP) {approx} heat-stable proteins (HSP) > mitochondria {approx} lysosomes + microsomes) was insensitive to the exposure route; both waterborne and diet-borne Cd ended up largely bound to the granule fraction. The subcellular distribution of Cd in the digestive gland differed markedly from that in the gills (HDP > HSP {approx} granules {approx} mitochondria > lysosomes + microsomes), but as in the case of the gills, this distribution was relatively insensitive to the exposure route. For both the gills and the digestive gland, the subcellular distributions of Cd differed from those observed in native bivalves that are chronically exposed to Cd in the field - in the short-term experimental exposures of P. grandis, metal detoxification was less effective than in chronically exposed native bivalves.

  20. Body dissatisfaction: can a short media literacy message reduce negative media exposure effects amongst adolescent girls?

    Science.gov (United States)

    Halliwell, Emma; Easun, Alice; Harcourt, Diana

    2011-05-01

    This experimental study examined whether a brief video intervention identifying the artificial nature of media images could protect adolescent girls from negative media exposure effects and body dissatisfaction. A 2 (intervention condition)×2 (exposure condition) between-groups design was used. Participants were 127 British girls aged between 10 and 13 recruited from two secondary schools. Girls were assigned to one of four experimental conditions. An intervention video was shown to half of the girls immediately before they viewed ultra-thin models or control images. The video was developed by Dove's Self-Esteem Fund and has the benefits of being professionally produced and freely available through the Internet. In the absence of the intervention video, viewing thin idealized models was associated with lower state body satisfaction and lower state body esteem than exposure to control images. However, viewing the video intervention immediately before exposure prevented this negative exposure effect. The results suggest that, in the short term, this widely available video prevents girls from making damaging social comparisons with media models. Although this study only examined short-term effects, the findings add to the growing evidence that media literacy interventions may be useful tools in protecting young girls from body dissatisfaction. ©2010 The British Psychological Society.

  1. Development of a Method to Assess the Radiation Dose due to Internal Exposure to Short-lived Radioactive Materials

    International Nuclear Information System (INIS)

    Benmaman, D.; Koch, J.; Ribak, J.

    2014-01-01

    Work with radioactive materials requires monitoring of the employees' exposure to ionizing radiation. Employees may be exposed to radiation from internal and/or external exposure. Control of external exposure is mostly conducted through personal radiation dosimeters provided to employees. Control of internal exposure can be performed by measuring the concentration of radioactive substances excreted in urine or through whole-body counting in which the entire body or target organs are scanned with a sensitive detector system (1). According to the regulations in Israel an employee that may be internally exposed must undergo an exposure control at least once every three months. The idea lying behind the control of internal exposure by urine testing is that if radioactive material has penetrated into the employee body, it can be detected even if the test is performed once every three months. A model was fitted for each element describing its dispersion in the body and its excretion therefrom (2). By means of this model, one can estimate the activity that entered the body and calculate the resulting radiation dose to which the worker was exposed. There is a problem to implement this method when it comes to short-lived radioactive materials, for which it is very likely that the material that penetrated into the body has decayed and cannot be detected by testing once every three months. As a result, workers with short-lived radioactive materials are presently not monitored for internal exposure, in contradiction to the requirements of the Safety at Work Regulations. The purpose of the study is to develop an alternative method to assess the amount of radioactive material absorbed in the body and the resulting radiation dose due to internal exposure of workers to short-lived radioactive materials

  2. Very-long-term and short-term chromatic adaptation: are their influences cumulative?

    Science.gov (United States)

    Belmore, Suzanne C; Shevell, Steven K

    2011-02-09

    Very-long-term (VLT) chromatic adaptation results from exposure to an altered chromatic environment for days or weeks. Color shifts from VLT adaptation are observed hours or days after leaving the altered environment. Short-term chromatic adaptation, on the other hand, results from exposure for a few minutes or less, with color shifts measured within seconds or a few minutes after the adapting light is extinguished; recovery to the pre-adapted state is complete in less than an hour. Here, both types of adaptation were combined. All adaptation was to reddish-appearing long-wavelength light. Shifts in unique yellow were measured following adaptation. Previous studies demonstrate shifts in unique yellow due to VLT chromatic adaptation, but shifts from short-term chromatic adaptation to comparable adapting light can be far greater than from VLT adaptation. The question considered here is whether the color shifts from VLT adaptation are cumulative with large shifts from short-term adaptation or, alternatively, does simultaneous short-term adaptation eliminate color shifts caused by VLT adaptation. The results show the color shifts from VLT and short-term adaptation together are cumulative, which indicates that both short-term and very-long-term chromatic adaptation affect color perception during natural viewing. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. SHORT-TERM EXPOSURE TO ATMOSPHERIC AMMONIA DOES NOT AFFECT LOW-TEMPERATURE HARDENING OF WINTER-WHEAT

    NARCIS (Netherlands)

    CLEMENT, JMAM; VENEMA, JH; VANHASSELT, PR

    The effect of atmospheric NH3 on low-temperature hardening of winter wheat (Triticum aestivum L. cv. Urban) was investigated. Growth and photosynthesis were stimulated by ammonia exposure. After a 14 d exposure at moderate temperatures (day/night 18.5/16 degrees C) total nitrogen content was

  4. Short-Term Exposure to Lambda-Cyhalothrin Negatively Affects the Survival and Memory-Related Characteristics of Worker Bees Apis mellifera.

    Science.gov (United States)

    Liao, Chun-Hua; He, Xu-Jiang; Wang, Zi-Long; Barron, Andrew B; Zhang, Bo; Zeng, Zhi-Jiang; Wu, Xiao-Bo

    2018-07-01

    Pesticides are considered one of the major contemporary stressors of honey bee health. In this study, the effects of short-term exposure to lambda-cyhalothrin on lifespan, learning, and memory-related characteristics of Apis mellifera were systematically examined. Short-term exposure to lambda-cyhalothrin in worker bees reduced lifespan, affected learning and memory performance, reduced the homing ability, and influenced the expression levels of two learning and memory-related genes of A. mellifera. This research identifies the nature of the sublethal effects of lambda-cyhalothrin on bees and the level of exposure that can be harmful to bee health. This new information will assist in establishing guidelines for the safe use of lambda-cyhalothrin in the field.

  5. Short term assays for risk evaluate of α irradiation

    International Nuclear Information System (INIS)

    Fritsch, P.; Beauvallet, M.; Masse, R.; Lafuma, J.

    1979-01-01

    The genetic effects induced by α irradiation were examined using short term assays in Procaryotes and Eucaryotes. Irradiation was produced by 239 Pu dissolved as a DTPA equimolar complex in the culture medium. Induced mutagenesis was not observed with Ames' test or when test for ouabain resistance in CHO cells was used: GTG resistance and chromosome aberrations in Eucaryote cells were increased at dose rate exposure down to 5 R.day -1 . Until an optimal delivered dose, these two biological effects have shown a linear increase as a function of the dose. In our experimental conditions α irradiation has appeared to be much more lethal than mutagenic. Using lower dose rate, corresponding to 1 and 3 R a day we could also demonstrate a linear increase with dose of the induced TG resistant cells. Efficiency per unit dose was 3 to 5 times superior to what was observed at 5 R.day -1 . This phenomenon could correspond to an induced cell sensitivity, and clearly pointed out that for chronic and low delivered doses, informations deduced from flash or short term α exposure are not valuable

  6. The influence of short-term concentration peaks on exposure risks in the vicinity of an episodic release of hydrogen sulphide

    International Nuclear Information System (INIS)

    1981-01-01

    In order to propose a methodology by which the influence of short-term concentration peaks on exposure risks could be estimated in the vicinity of an atmospheric release of hydrogen sulphide (H 2 S), an extensive and up-to-date review of H 2 S toxicity was conducted, with emphasis on acute and sub-acute poisoning. The literature on animal studies and cases of human exposure were used to derive a lethal dose relationship(concentration-exposure time) appropriate for the general population. A statistical model was developed which calculates the probability of short-term concentrations exceeding the lethal level given the downwind range from the release, the short-term averaging time of interest, the long-term average concentration, and metereological and terrain conditions . Results were obtained for passive releases of H 2 S under a range of hypothetical conditions. Interpretation of these results is given in terms of the overall probability of lethal exposure during a 30-minute episode. The likely influence of heavy water plant gas dispersion systems is also addressed. (author)

  7. Growth Recovery of Lemna gibba and Lemna minor Following a 7-Day Exposure to the Herbicide Diuron.

    Science.gov (United States)

    Burns, Mitchell; Hanson, Mark L; Prosser, Ryan S; Crossan, Angus N; Kennedy, Ivan R

    2015-08-01

    In agricultural catchments, aquatic ecosystems can experience a pulse exposure to pesticides. Following such exposure, non-target organisms that are not extirpated may recover. This paper investigates the potential of two duckweed species (Lemna minor and Lemna gibba) to recover from a 7-day exposure to different concentrations (0.4-208 µg L(-1)) of the herbicide diuron. There was significant inhibition in the growth and biomass after the initial 7-day exposure (e.g. frond number EC50=59.2 and 52.2 µg L(-1) for L. minor and L. gibba, respectively). Following transfer to clean media, recovery (the highest concentration yielding no significant difference in the effect endpoint from the control) was observed for all effects endpoints at concentrations ranging 60-111 µg L(-1) for L. minor and 60-208 µg L(-1) for L. gibba. These results suggest that recovery is possible for primary producers at environmentally relevant concentrations considered significant in ecological risk assessment.

  8. Survey of exposure of physiotherapist operators to emissions from microwave and short wave diathermy equipment

    International Nuclear Information System (INIS)

    Coppell, R.B.

    1987-01-01

    An extensive survey of levels of electromagnetic fields in the vicinity of microwave and short wave diathermy equipment is presented and occupational exposure of physiotherapist operators is assessed. There was a good response to mailed questionnaires to 18 hospital boards, 21 private hospitals, and 148 private physiotherapy practices in Christchruch and centres of the north island of New Zealand. Within 34 public hospitals and 57 private practice of those so contacted, who also volunteered to participate, measurements were made in numerous positions about operating equipment. For practical reasons, manufactured phantom sections were substituted for real patients. Levels of microwave power flux density were found to vary according to position and to orientation of equipment and patient phantom. Provided, microwave diathermy equipment is used with reasonable care, excessive exposure of the physiotherapist operator is considered very unlikely. Levels of electric and magnetic field strength squared in the vicinity of simulated body sections under short wave diathermy treatment were found to be highly localised and strongly dependent upon the type of applicator used and the proximity of connecting leads. Operating procedures, including distances of separation, are recommended to protect operators from excessive exposure. (author). 30 refs., 8 tabs., 4 figs., ills

  9. The relationships between short-term exposure to particulate matter and mortality in Korea: impact of particulate matter exposure metrics for sub-daily exposures

    International Nuclear Information System (INIS)

    Son, Ji-Young; Bell, Michelle L

    2013-01-01

    Most studies of short-term particulate matter (PM) exposure use 24 h averages. However, other pollutants have stronger effects in shorter timeframes, which has influenced policy (e.g., ozone 8 h maximum). The selection of appropriate exposure timeframes is important for effective regulation. The US EPA identified health effects for sub-daily PM exposures as a critical research need. Unlike most areas, Seoul, Korea has hourly measurements of PM 10 , although not PM 2.5 . We investigated PM 10 and mortality (total, cardiovascular, respiratory) in Seoul (1999–2009) considering sub-daily exposures: 24 h, daytime (7 am–8 pm), morning (7–10 am), nighttime (8 pm–7 am), and 1 h daily maximum. We applied Poisson generalized linear modeling adjusting for temporal trends and meteorology. All PM 10 metrics were significantly associated with total mortality. Compared to other exposure timeframes, morning exposure had the most certain effect on total mortality (based on statistical significance). Increases of 10 μg m −3 in 24 h, daytime, morning, nighttime, and 1 h maximum PM 10 were associated with 0.15% (95% confidence interval 0.02–0.28%), 0.14% (0.01–0.27%), 0.10% (0.03–0.18%), 0.12% (0.03–0.22%), and 0.10% (0.00–0.21%) increases in total mortality, respectively. PM 10 was significantly associated with cardiovascular mortality for 24 h, morning, and nighttime exposures. We did not identify significant associations with respiratory mortality. The results support use of a 24 h averaging time as an appropriate metric for health studies and regulation, particularly for PM 10 and mortality. (letter)

  10. Chronic prenatal lead exposure impairs long-term memory in day old chicks.

    Science.gov (United States)

    Zhong, Zhaoming; Zhang, Chunxiao; Rizak, Joshua D; Cui, Yonghua; Xu, Shiqing; Che, Yi

    2010-05-26

    Environmental exposure to lead during developmental stages has been established as a potential cause of intellectual deficits. The high susceptibility of rapidly developing fetal and infant brains to external factors suggests that impairment of later cognitive functions may arise from relatively minor prenatal exposure to environmental lead levels. In this study, we used the one-trial passive avoidance learning paradigm with day old chicks to evaluate memory function and memory consolidation in response to prenatal lead exposure. Lead acetate (5.5mg/kg, 11mg/kg, 16.5mg/kg) was administered daily from E9 to E16 via direct injection into the airspace in chick eggs. Higher doses of lead acetate (11mg/kg, 16.5mg/kg) administration had significant effects on the hatching success (23.4 and 17, respectively) and hatch weight ( approximately 10% decrease) of chicks when compared to equivalent treatments of sodium acetate (11mg/kg, 16.5mg/kg) (plong-term memory after 120min following training in the one-trial passive avoidance learning task (pmemory processes. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

  11. Metabolomics reveals an involvement of pantothenate for male production responding to the short-day stimulus in the water flea, Daphnia pulex.

    Science.gov (United States)

    Toyota, Kenji; Gavin, Alex; Miyagawa, Shinichi; Viant, Mark R; Iguchi, Taisen

    2016-04-26

    Under favorable conditions, the micro-crustacean Daphnia pulex produces female offspring by parthenogenesis, whereas under unfavorable conditions, they produce male offspring to induce sexual reproduction (environmental sex determination: ESD). We recently established a suitable system for ESD studies using D. pulex WTN6 strain, in which the sex of the offspring can be regulated by alterations in day-length; long-day and short-day conditions can induce female and male offspring, respectively. Taking advantage of this system, we have already demonstrated that methyl farnesoate (MF) synthesis is necessary for male offspring production, and identified ionotropic glutamate receptors as an upstream regulator of MF signaling. Despite these findings, the molecular mechanisms associated with MF signaling have not yet been well elucidated. In this study, we analyzed the whole metabolic profiles of mother daphnids reared under long-day (female-producing) and short-day (male-producing) conditions, and discovered that pantothenate (vitamin B5), a known precursor to coenzyme A, was significantly accumulated in response to the short-day condition. To confirm the innate role of pantothenate in D. pulex, this metabolite was administered to mother daphnids resulting in a significantly increased proportion of male offspring producing mothers. This study provides novel insights of the metabolic mechanisms of the ESD system in D. pulex.

  12. Spectral indices of cardiovascular adaptations to short-term simulated microgravity exposure

    Science.gov (United States)

    Patwardhan, A. R.; Evans, J. M.; Berk, M.; Grande, K. J.; Charles, J. B.; Knapp, C. F.

    1995-01-01

    We investigated the effects of exposure to microgravity on the baseline autonomic balance in cardiovascular regulation using spectral analysis of cardiovascular variables measured during supine rest. Heart rate, arterial pressure, radial flow, thoracic fluid impedance and central venous pressure were recorded from nine volunteers before and after simulated microgravity, produced by 20 hours of 6 degrees head down bedrest plus furosemide. Spectral powers increased after simulated microgravity in the low frequency region (centered at about 0.03 Hz) in arterial pressure, heart rate and radial flow, and decreased in the respiratory frequency region (centered at about 0.25 Hz) in heart rate. Reduced heart rate power in the respiratory frequency region indicates reduced parasympathetic influence on the heart. A concurrent increase in the low frequency power in arterial pressure, heart rate, and radial flow indicates increased sympathetic influence. These results suggest that the baseline autonomic balance in cardiovascular regulation is shifted towards increased sympathetic and decreased parasympathetic influence after exposure to short-term simulated microgravity.

  13. Comparative study of the pharmacokinetics of carbon tetrachloride in the rat following repeated inhalation exposures of 8 and 11.5 hr/day

    International Nuclear Information System (INIS)

    Paustenbach, D.J.; Carlson, G.P.; Christian, J.E.; Born, G.S.

    1986-01-01

    To evaluate whether exposure to inhaled vapors for periods longer than 8 hr/day could affect the rates and routes of elimination, male Sprague-Dawley rats were repeatedly exposed to 100 ppm of radiolabeled carbon tetrachloride ( 14 CCl 4 ) in a closed-loop chamber. One group was exposed for 8 hr/day for 5 days and another group for 11.5 hr/day for 4 days. Two other groups were exposed for either 8 hr/day for 10 of 12 consecutive days or 11.5 hr/day for 7 of 10 days. The elimination of 14 C activity was measured in the expired air, urine, and feces for up to 100 hr following exposure and the pharmacokinetic parameters were determined. Following 2 weeks of exposure to the 8-hr/day schedule, 14 CCl 4 in the breath and 14 C activity in the feces comprised 45 and 48% of the total 14 C excreted, respectively. Following 2 weeks of exposure to the 11.5-hr/day schedule, the values were 32 and 62%, respectively, indicating that repeated exposure to the longer schedule altered the route of elimination of CCl 4 . Regardless of the period of exposure, less than 8% of the inhaled 14 CCl 4 was excreted in the urine and less than 2% was exhaled in the breath as the 14 CO 2 metabolite. Approximately 97-98% of the 14 C activity in the expired air was 14 CCl 4 . The quantities of 14 C noted in the feces and urine suggest that more than 60% of the inhaled CCl 4 was metabolized. Elimination of 14 CCl 4 and 14 CO 2 in the breath followed a two-compartment, first-order pharmacokinetic model (r2 = 0.98). For rats exposed 8 hr/day and 11.5 hr/day for 2 weeks, the average half-lives for elimination of 14 CCl 4 in the breath for the fast (alpha) and slow (beta) phases averaged 96 and 455 min, and 89 and 568 min, respectively. The average alpha and beta half-lives for elimination of 14 CO 2 in the breath

  14. Mere odor exposure learning in the rat neonate immediately after birth and 1 day later.

    Science.gov (United States)

    Miller, Stacie S; Spear, Norman E

    2010-05-01

    Rat pups are more resistant to retroactive associative interference 3 hr after birth than 24 hr later [Cheslock et al. [2004] Developmental Science, 7, 581-598]. The present experiments tested the effect of age, retention interval and dam presence during the retention interval on odor-induced motor activity subsequent to mere odor exposure. Rats were exposed to an hour of odor immediately after birth or approximately 1 day later and tested after a given retention interval (3 or 27 hr [Exp 1]; 0, 30, 75, or 180 min [Exp. 2]). They spent the retention interval either in the presence or absence of a foster dam (Exp. 1 and 3). After the retention interval, pups were tested in a 4-min activity test including a 2-min baseline period and 2 min of odor exposure. Overall activity was scored during tape-playback. Odor-exposed pups were more active than nonexposed pups during reexposure to the odor during testing, but this was true only for P0 pups. In contrast, P1 pups without prior odor exposure were active during testing and behaviorally quieted in the presence of the odor they were previously exposed to. Though 1 day apart, newborn rats just hours old lack many of the experiences that a 1-day-old has had including nursing, huddling, and being groomed. These experiences are associated with, among other stimuli, a barrage of olfactory cues (e.g., colostrum, saliva, dander, feces, and urine). P0 and P1 pups also differ in their proximity from the birthing experience and associated neurochemical changes. The age-related pattern of responding to odors based on previous odor exposure was discussed in relation to these and other possibilities.

  15. Mere odor exposure learning in the rat neonate immediately after birth and one day later

    Science.gov (United States)

    Miller, Stacie S.; Spear, Norman E.

    2011-01-01

    Rat pups are more resistant to retroactive associative interference 3 hrs after birth than 24 hours later (Cheslock, Sanders, & Spear, 2004). The present experiments tested the effect of age, retention interval and dam presence during the retention interval on odor-induced motor activity subsequent to mere odor exposure. Rats were exposed to an hour of odor immediately after birth or approximately one day later and tested after a given retention interval (3 hrs or 27 hrs [Exp 1]; 0, 30, 75, or 180 min [Exp. 2]). They spent the retention interval either in the presence or absence of a foster dam (Exp. 1 and 3). After the retention interval, pups were tested in a four-minute activity test including a two-minute baseline period and two minutes of odor exposure. Overall activity was scored during tape-playback. Odor-exposed pups were more active than non-exposed pups during reexposure to the odor during testing, but this was true only for P0 pups. In contrast, P1 pups without prior odor exposure were active during testing and behaviorally quieted in the presence of the odor they were previously exposed to. Though one day apart, newborn rats just hours old lack many of the experiences that a one day old has had including nursing, huddling, and being groomed. These experiences are associated with, among other stimuli, a barrage of olfactory cues (e.g., colostrum, saliva, dander, feces, and urine). P0 and P1 pups also differ in their proximity from the birthing experience and associated neurochemical changes. The age-related pattern of responding to odors based on previous odor exposure was discussed in relation to these and other possibilities. PMID:20411590

  16. Effects of chronic radiation exposure on the reproduction of dogs

    International Nuclear Information System (INIS)

    Shifrine, M.; Kawakami, T.G.; Rasmussen, C.

    1984-01-01

    During studies on radiation leukemogenesis 7 dogs were exposed to 4.4 R/day starting at 150 days of age. Three of these dogs were females. To determine whether the exposure to chronic irradiation affected their reproductive capacity the three bitches were bred. Two of the bitches did not conceive, and one of these died shortly thereafter from myeloproliferative disease (MPD) which could have been a factor. The third bitch whelped 7 pups, one of which died shortly after birth, and the other 6 are healthy 2 months after birth. 1 table

  17. Mechanistic models for cancer development after short time radiation exposure

    International Nuclear Information System (INIS)

    Kottbauer, M. M.

    1997-12-01

    In this work two biological based models were developed. First the single-hit model for solid tumors (SHM-S) and second the single-hit model for leukemia (SHM-L). These models are a further development of the Armitage-Doll model for the special case of a short time radiation exposure. The basis of the models is the multistage process of carcinogeneses. The single-hit models provide simultaneously the age-dependent cancer-rate of spontaneous and radiation induced tumors as well as the dose-effect relationships at any age after exposure. The SHM-S leads to a biological based dose-effect relationship, which is similar to the relative risk model suggested by the ICRP 60. The SHM-S describes the increased mortality rate of the bomb survivors more accurate than the relative risk model. The SHM-L results in an additive dose-effect relationship. It is shown that only small differences in the derivation of the two models lead to the two dose-effect relationships. Beside the radiation exposure the new models consider the decrease of the cancer mortality rate at higher ages (age>75) which can be traced back mainly to three causes: competitive causes of death, reduction of cell proliferation and reduction of risk groups. The single-hit models also consider children cancer, the different rates of incidence and mortality, influence of the immune system and the cell-killing effect. (author)

  18. FASTING IN COUNTRIES WHERE THE DAY IS VERY LONG OR VERY SHORT: A Study of Muslims in the Netherlands

    Directory of Open Access Journals (Sweden)

    Ahmad Najib Burhani

    2013-07-01

    Full Text Available Ramadan falls both during winter and autumn months, when the days are cool and short, and spring and summer months, when the days are long and hot. Fasting in areas where the climate is extremely hot and the day is more than twenty hours is a double hardship that can be a dangerous assault on physical condition. In contrast to that, fasting in areas where the day is very short is, to some extent, like an interval between breakfast and lunch or between lunch and dinner. This article, therefore, intends to discover how Muslims in the countries where the day is either very long or very short deal with the problem of the fasting time. This research is based on the practices of some Muslims in the Netherlands with a variety of countries of origin. This article attempts to answer the following questions: How did they manage their fasting time in the summer or when the day is very long? How did they manage their fasting time in the winter or when the day is very short? What kind of fiqh book or fatwa did they use as reference? Did they think that fasting obligation was dangerous for their health when the day was very long?   [Bulan Ramadan bisa tiba pada musim dingin dan musim gugur, ketika siang hari pendek dan sejuk, tapi Ramadan juga bisa tiba pada musim semi dan musim panas, ketika siang hari sangat panjang dan panas. Puasa di tempat yang sangat panas dan dengan panjang siang hari lebih dari dua puluh jam adalah beban yang berat dan bisa berbahaya bagi kondisi fisik pelakunya. Sebaliknya, puasa di tempat yang siang harinya sangat pendek terasa tak seperti puasa karena ia hanya seperti interval antara makan pagi dan makan siang atau antara makan siang dan makan malam. Tulisan ini didasarkan pada penelitian terhadap praktik berpuasa orang-orang Islam di Belanda dari berbagai negara asal. Pertanyaan yang ingin dijawab dalam tulisan ini adalah: Bagaimana umat Islam Belanda melaksanakan puasa pada musim panas atau ketika siang hari teramat panjang

  19. Effect of serial-day exposure to nitrogen dioxide on airway and blood leukocytes and lymphocyte subsets

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, C.; Chen, L.L.; Erle, D.J.; Balmes, J.R. [Univ. of California, Lung Biology Center and Center for Occupational and Environmental Health, San Francisco, CA (United States); Christian, D.L.; Welch, B.S.; Dunham, E. [Univ. of California, Lung Biology Center, San Francisco, CA (United States); Kleinman, M.T. [Univ. of California, Dept. of Community and Environmental Medicine, Irvine, CA (United States)

    2000-07-01

    Nitrogen dioxide (NO{sub 2}) is a free radical-producing oxidant gas. Inhalation of NO2 could cause airway inflammation, and decrease immune function. This experiment tested the hypothesis that exposure to NO{sub 2} would: (1) increase leukocytes in bronchoalveolar lavage (BAL); and (2) change the distribution of lymphocyte subsets and activation in BAL and peripheral blood (PB). Using a counter-balanced, repeated-measures design, 15 healthy volunteers were exposed to filtered air (FA) or 2.0 parts per million NO{sub 2} for 4 h.day{sup -1} (4 x 30 min of exercise), for three consecutive days. Bronchoscopy was performed 18 h following each exposure set, and PB was drawn pre-exposure and pre-bronchoscopy. Flow cytometry was used to enumerate lymphocyte subsets and activation makers in BAL and PB. In the bronchial fraction, there was an increase in the percentage of neutrophils following NO2 exposure compared to FA (median (interquartile range): 10.6 (4.8. 17.2)% versus 5.3 (2.5-8.3)%; p=0.005). In the BAL, there was a decrease in the percentage of T-helper cells following NO{sub 2} exposure compared to FA (55.9 (40.8-62.7)% versus 61.6 (52.6-65.2)%; p=0.022). For PB, there were no between-condition differences in any leukocyte or lymphocyte subsets, or activation. In conclusion exposure to nitrogen dioxide results in bronchial inflammation and a minimal change in bronchoalveolar lavage T-helper cells, and no changes in peripheral blood cells. (au)

  20. Extended fish short term reproduction assays with the fathead minnow and Japanese medaka: No evidence of impaired fecundity from exposure to atrazine.

    Science.gov (United States)

    Brain, Richard A; Schneider, Suzanne Z; Anderson, Julie C; Knopper, Loren D; Wolf, Jeffrey C; Hanson, Mark L

    2018-08-01

    Short-term reproduction assays were conducted with fathead minnow (Pimephales promelas) and Japanese medaka (Oryzias latipes) to evaluate responses from atrazine exposure at environmentally relevant concentrations and above. Breeding groups of fish with multiple males and females were exposed to atrazine under flow-through conditions. Fathead minnows were exposed to mean measured concentrations of 1.0, 10, 26, 52, and 105 μg atrazine/L for 28 days. Medaka were exposed to mean measured concentrations of 9.4, 48, 74, 97, and 244 μg atrazine/L for 28 or 29 days. Fish were evaluated for survival, fecundity, fertility, total length, wet weight, secondary sex characteristics, gonadosomatic index (GSI) (P. promelas only), plasma or hepatic vitellogenin (VTG), and histopathology of gonads. General observations of health and behaviour were also conducted. There were no statistically significant effects (i.e., p < 0.05) of atrazine on survival, size, reproduction, behaviour, GSI, VTG, or secondary sex characteristics in either species at any exposure level. In fathead minnows, there were no histopathological findings associated with atrazine exposure in male fish, but there was an increased proportion of Stage 4.0 ovaries accompanied by an increase in proportion of Grade 3 post-ovulatory follicles in females of the 105 μg/L treatment group. Without a concomitant increase in oocyte atresia, neither of these findings are considered adverse for the health of the fish. In medaka, there were no significant effects of atrazine exposure on histopathology in either sex. These data support current weight-of-evidence assessments that atrazine does not cause direct adverse effects on fish reproduction at environmentally realistic concentrations. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Moderate Maternal Alcohol Exposure on Gestational Day 12 Impacts Anxiety-Like Behavior in Offspring

    Directory of Open Access Journals (Sweden)

    Siara K. Rouzer

    2017-09-01

    Full Text Available Among the numerous consequences of prenatal alcohol exposure (PAE is an increase in anxiety-like behavior that can prove debilitating to daily functioning. A significant body of literature has linked gestational day 12 (G12 heavy ethanol exposure with social anxiety, evident in adolescent males and females. However, the association between non-social anxiety-like behavior and moderate alcohol exposure, a more common pattern of drinking in pregnant women, is yet unidentified. To model moderate PAE (mPAE, we exposed pregnant Sprague-Dawley rats to either room air or vaporized ethanol for 6 h on G12. Adolescent offspring were then tested on postnatal days (P 41–47 in one of the following four anxiety assays: novelty-induced hypophagia (NIH, elevated plus maze (EPM, light-dark box (LDB and open-field (OF. Our findings revealed significant increases in measures of anxiety-like behavior in male PAE offspring in the NIH, LDB and OF, with no differences observed in females on any test. Additionally, male offspring who demonstrated heightened anxiety-like behavior as adolescents demonstrated decreased anxiety-like behavior in adulthood, as measured by a marble-burying test (MBT, while females continued to be unaffected in adulthood. These results suggest that mPAE leads to dynamic changes in anxiety-like behavior exclusively in male offspring.

  2. Exposure of amateur gardeners to pesticides via the non-gloved skin per day.

    Science.gov (United States)

    Beránková, Martina; Hojerová, Jarmila; Melegová, Linda

    2017-10-01

    To predict a risk to gardeners not wearing protective gloves, the dermal absorption of three active insecticides was assessed in vitro using porcine ear-skin simulating 1-h handling of diluted plant protection products. Acetamiprid and Pirimicarb were found in the receptor fluid immediately after 1-h skin exposure, whereas Chlorpyrifos-methyl absorbed in the skin was not released into the receptor fluid even after 23 hours. The Estimated Gardener Exposure Level (EGEL) at 23 hours after 1-h exposure for two worst-case scenarios (i) non-gloved hands; (ii) non-gloved hands/uncovered forearms, was (i) 0.002, 0.042, and 0.057; (ii) 0.006, 0.101, and 0.135 mg/kg bw/day for Acetamiprid, Pirimicarb, and Chlorpyrifos-methyl, respectively, although the systemically available Chlorpyrifos-methyl amount, due to retention in the skin, is probably lower than determined. The Gardener Exposure Risk (GER), as a ratio of Acceptable Operator Exposure Level (databased values) to EGEL, for Acetamiprid was (i) 35 and 12-fold higher than the limit 1, so the risk via the skin is assumed to be low. Based on the GER values of (i) 0.83 and 0.18; (ii) 0.34 and 0.07 (i.e.health risk to gardeners handling pesticide products without skin protection. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Effect of individual parameter changes on the outcome of the estimated short-term dietary exposure to pesticides.

    Science.gov (United States)

    van der Velde-Koerts, Trijntje; Breysse, Nicolas; Pattingre, Lauriane; Hamey, Paul Y; Lutze, Jason; Mahieu, Karin; Margerison, Sam; Ossendorp, Bernadette C; Reich, Hermine; Rietveld, Anton; Sarda, Xavier; Vial, Gaelle; Sieke, Christian

    2018-06-03

    In 2015 a scientific workshop was held in Geneva, where updating the International Estimate of Short-Term Intake (IESTI) equations was suggested. This paper studies the effects of the proposed changes in residue inputs, large portions, variability factors and unit weights on the overall short-term dietary exposure estimate. Depending on the IESTI case equation, a median increase in estimated overall exposure by a factor of 1.0-6.8 was observed when the current IESTI equations are replaced by the proposed IESTI equations. The highest increase in the estimated exposure arises from the replacement of the median residue (STMR) by the maximum residue limit (MRL) for bulked and blended commodities (case 3 equations). The change in large portion parameter does not have a significant impact on the estimated exposure. The use of large portions derived from the general population covering all age groups and bodyweights should be avoided when large portions are not expressed on an individual bodyweight basis. Replacement of the highest residue (HR) by the MRL and removal of the unit weight each increase the estimated exposure for small-, medium- and large-sized commodities (case 1, case 2a or case 2b equations). However, within the EU framework lowering of the variability factor from 7 or 5 to 3 counterbalances the effect of changes in other parameters, resulting in an estimated overall exposure change for the EU situation of a factor of 0.87-1.7 and 0.6-1.4 for IESTI case 2a and case 2b equations, respectively.

  4. Methylmercury exposure for 14 days (short-term) produces behavioral and biochemical changes in mouse cerebellum, liver, and serum.

    Science.gov (United States)

    Macedo-Júnior, Sérgio José; Luiz-Cerutti, Murilo; Nascimento, Denise B; Farina, Marcelo; Soares Santos, Adair Roberto; de Azevedo Maia, Alcíbia Helena

    2017-01-01

    Various studies on methylmercury (MeHg)-induced toxicity focused on the central nervous system (CNS) as a primary target. However, MeHg-mediated toxicity is related to metallic interaction with electrophilic groups, which are not solely restricted to the CNS, but these reactive groups are present ubiquitously in several systems/organs. The aim of this study was thus to examine MeHg-induced systemic toxicity in mice using a standardized neurotoxicology testing exposure model to measure cerebellar neurotoxicity by determining biochemical and behavioral parameters in the cerebellum. After 2 weeks exposure to MeHg (40 µg/ml; diluted in drinking water; ad libitum), adult male Swiss mice showed a marked motor impairment characteristic of cerebellar toxicity as noted in the following tests: rotarod, beam walking, pole, and hind limb clasping. MeHg treatment resulted in Hg deposition in the cerebellum as well as reduction in cerebellar weight, glutathione peroxidase (GPx) activity, and interleukin (IL)-6 levels. MeHg ingestion increased cerebellar glutathione reductase (GR) activity and brain-derived neurotrophic factor (BDNF) levels. In addition to cerebellar toxicity, MeHg treatment also elevated total and non-high density lipoprotein (non-HDL) cholesterol levels, as well as serum aspartate transaminase (AST) and alanine transaminase (ALT) enzymatic activities, systemic parameters. Increased liver weight and reduced serum urea levels were also noted in MeHg-exposed mice. Taken together, our findings demonstrated that a well-standardized exposure protocol to examine MeHg-induced neurotoxicity also produced systemic toxicity in mice, which was characterized by changes in markers of hepatic function as well as serum lipid homeostasis.

  5. Short exposure to a diet rich in both fat and sugar or sugar alone impairs place, but not object recognition memory in rats.

    Science.gov (United States)

    Beilharz, Jessica E; Maniam, Jayanthi; Morris, Margaret J

    2014-03-01

    High energy diets have been shown to impair cognition however, the rapidity of these effects, and the dietary component/s responsible are currently unclear. We conducted two experiments in rats to examine the effects of short-term exposure to a diet rich in sugar and fat or rich in sugar on object (perirhinal-dependent) and place (hippocampal-dependent) recognition memory, and the role of inflammatory mediators in these responses. In Experiment 1, rats fed a cafeteria style diet containing chow supplemented with lard, cakes, biscuits, and a 10% sucrose solution performed worse on the place, but not the object recognition task, than chow fed control rats when tested after 5, 11, and 20 days. In Experiment 2, rats fed the cafeteria style diet either with or without sucrose and rats fed chow supplemented with sucrose also performed worse on the place, but not the object recognition task when tested after 5, 11, and 20 days. Rats fed the cafeteria diets consumed five times more energy than control rats and exhibited increased plasma leptin, insulin and triglyceride concentrations; these were not affected in the sucrose only rats. Rats exposed to sucrose exhibited both increased hippocampal inflammation (TNF-α and IL-1β mRNA) and oxidative stress, as indicated by an upregulation of NRF1 mRNA compared to control rats. In contrast, these markers were not significantly elevated in rats that received the cafeteria diet without added sucrose. Hippocampal BDNF and neuritin mRNA were similar across all groups. These results show that relatively short exposures to diets rich in both fat and sugar or rich in sugar, impair hippocampal-dependent place recognition memory prior to the emergence of weight differences, and suggest a role for oxidative stress and neuroinflammation in this impairment. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  6. Night work, light exposure and melatonin on work days and days off

    DEFF Research Database (Denmark)

    Daugaard, Stine; Garde, Anne Helene; Bonde, Jens Peter Ellekilde

    2017-01-01

    We aimed to examine the effects of night work on salivary melatonin concentration during and subsequent to night work and the mediating role of light. We included 254 day workers and 87 night workers who were followed during 322 work days and 301 days off work. Each day was defined as the 24 hour...... period starting from the beginning of a night shift or from waking in the mornings with day work and days off. Light levels were recorded and synchronized with diary information (start and end of sleep and work). On average, participants provided four saliva samples per day, and these were analyzed...... for melatonin concentration by liquid chromatography tandem mass spectrometry (LC-MS/MS). Differences between day and night workers on work days and days off were assessed with multilevel regression models with melatonin concentration as the primary outcome. All models were stratified or adjusted by time of day...

  7. NASA 14 Day Undersea Missions: A Short-Duration Spaceflight Analog for Immune System Dysregulation?

    Science.gov (United States)

    Crucian, B. E.; Stowe, R. P.; Mehta, S. K.; Chouker, A.; Feuerecker, M.; Quiriarte, H.; Pierson, D. L.; Sams, C. F.

    2011-01-01

    This poster paper reviews the use of 14 day undersea missions as a possible analog for short duration spaceflight for the study of immune system dysregulation. Sixteen subjects from the the NASA Extreme Enviro nment Mission Operations (NEEMO) 12, 13 and 14 missions were studied for immune system dysregulation. The assays that are presented in this poster are the Virleukocyte subsets, the T Cell functions, and the intracellular/secreted cytokine profiles. Other assays were performed, but are not included in this presntation.

  8. Examining the Contemporaneous, Short-Term, and Long-Term Effects of Secondary Exposure to Violence on Adolescent Substance Use.

    Science.gov (United States)

    Zimmerman, Gregory M; Kushner, Mackenzie

    2017-09-01

    The relationship between secondary exposure to violence-defined as witnessing violence in the home, community, or school-and adolescent substance use is well-documented. Yet, multi-wave empirical studies examining this relationship are sparse. In addition, studies have only begun to examine whether this relationship varies by the situational components of the violent event. Using data from the Project on Human Development in Chicago Neighborhoods (PHDCN), this study examines the contemporaneous, short-term, and long-term effects of secondary exposure to violence on substance use, and whether witnessing violence in which a weapon is present has a different impact on adolescent substance use than does witnessing violence without a weapon. Hierarchical logistic regression models on a racially and ethnically diverse sample of 1670 youth (51.5% female) residing in 79 neighborhoods indicated that: (1) the effects of secondary exposure to violence on alcohol and marijuana use were enduring, albeit attenuated, over time; (2) the effect of secondary exposure to violence on illicit drug use was suppressed in the short-term but significant in the long-term; (3) witnessing violence without a weapon was salient for alcohol and marijuana use at all time points; and (4) witnessing violence with a weapon impacted illicit drug use in the long-term. The results suggest that addressing the consequences of secondary exposure to violence requires prolonged intervention efforts and that the study of secondary exposure to violence requires a more nuanced approach that accounts for situational aspects of the violent event.

  9. Short-term UV-B radiation and ozone exposure effects on aromatic secondary metabolite accumulation and shoot growth of flavonoid-deficient Arabidopsis mutants

    International Nuclear Information System (INIS)

    Ormrod, D.P.; Landry, L.G.; Conklin, P.L.

    1995-01-01

    The presence of UV-absorptive substances in the epidermal cells of leaves is thought to protect mesophyll tissues from the harmful effects of UV-B radiation. We examined the influence of short-term UV-B exposures on UV-absorptive (330 nm) sinapates and flavonols, and on shoot growth of the Arabidopsis wild type ecotype Landsberg erecta and two mutants. 114 deficient in chalcone synthase, and 115, deficient in chalcone/flavonone isomerase. Sequential ozone exposures were used to determine the effects of oxidative stress The levels of sinapates and flavonols on a leaf fresh weight basis increased substantially in the wild type and sinapates increased in the 114 mutant in vegetative vegetative/reproductive transitional and reproductive stage plants in response to short-term (48h) UV-B radiation. When UV-B was discontinued the levels generally decreased lo pre-exposure levels after 48 h in vegetative/reproductive but not in reproductive plants. Exposure to ozone before or alter UV-B treatment did not consistently affect the levels of these UV-absorptive compounds. Dry matter accumulation was less affected by UV-B at the vegetative and reproductive stages than at the vegetative/reproductive stage. At the vegetative/reproductive stage, shoot growth of all 3 genotypes was retarded by UV-B. Growth was not retarded by short-term ozone exposure alone but when exposure to ozone followed UV-B exposure, growth was reduced in all genotypes. Leaf cupping appeared on 115 plants exposed to UV-B

  10. Neuron specific metabolic adaptations following multi-day exposures to oxygen glucose deprivation.

    Science.gov (United States)

    Zeiger, Stephanie L H; McKenzie, Jennifer R; Stankowski, Jeannette N; Martin, Jacob A; Cliffel, David E; McLaughlin, BethAnn

    2010-11-01

    Prior exposure to sub toxic insults can induce a powerful endogenous neuroprotective program known as ischemic preconditioning. Current models typically rely on a single stress episode to induce neuroprotection whereas the clinical reality is that patients may experience multiple transient ischemic attacks (TIAs) prior to suffering a stroke. We sought to develop a neuron-enriched preconditioning model using multiple oxygen glucose deprivation (OGD) episodes to assess the endogenous protective mechanisms neurons implement at the metabolic and cellular level. We found that neurons exposed to a five minute period of glucose deprivation recovered oxygen utilization and lactate production using novel microphysiometry techniques. Using the non-toxic and energetically favorable five minute exposure, we developed a preconditioning paradigm where neurons are exposed to this brief OGD for three consecutive days. These cells experienced a 45% greater survival following an otherwise lethal event and exhibited a longer lasting window of protection in comparison to our previous in vitro preconditioning model using a single stress. As in other models, preconditioned cells exhibited mild caspase activation, an increase in oxidized proteins and a requirement for reactive oxygen species for neuroprotection. Heat shock protein 70 was upregulated during preconditioning, yet the majority of this protein was released extracellularly. We believe coupling this neuron-enriched multi-day model with microphysiometry will allow us to assess neuronal specific real-time metabolic adaptations necessary for preconditioning. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Modelling short term individual exposure from airborne hazardous releases in urban environments

    International Nuclear Information System (INIS)

    Bartzis, J.G.; Efthimiou, G.C.; Andronopoulos, S.

    2015-01-01

    Highlights: • The statistical behavior of the variability of individual exposure is described with a beta function. • The extreme value in the beta function is properly addressed by [5] correlation. • Two different datasets gave clear support to the proposed novel theory and its hypotheses. - Abstract: A key issue, in order to be able to cope with deliberate or accidental atmospheric releases of hazardous substances, is the ability to reliably predict the individual exposure downstream the source. In many situations, the release time and/or the health relevant exposure time is short compared to mean concentration time scales. In such a case, a significant scatter of exposure levels is expected due to the stochastic nature of turbulence. The problem becomes even more complex when dispersion occurs over urban environments. The present work is the first attempt to approximate on generic terms, the statistical behavior of the abovementioned variability with a beta distribution probability density function (beta-pdf) which has proved to be quite successful. The important issue of the extreme concentration value in beta-pdf seems to be properly addressed by the [5] correlation in which global values of its associated constants are proposed. Two substantially different datasets, the wind tunnel Michelstadt experiment and the field Mock Urban Setting Trial (MUST) experiment gave clear support to the proposed novel theory and its hypotheses. In addition, the present work can be considered as basis for further investigation and model refinements.

  12. Modelling short term individual exposure from airborne hazardous releases in urban environments

    Energy Technology Data Exchange (ETDEWEB)

    Bartzis, J.G., E-mail: bartzis@uowm.gr [University of Western Macedonia, Dept. of Mechanical Engineering, Sialvera & Bakola Str., 50100, Kozani (Greece); Efthimiou, G.C.; Andronopoulos, S. [Environmental Research Laboratory, INRASTES, NCSR Demokritos, Patriarchou Grigoriou & Neapoleos Str., 15310, Aghia Paraskevi (Greece)

    2015-12-30

    Highlights: • The statistical behavior of the variability of individual exposure is described with a beta function. • The extreme value in the beta function is properly addressed by [5] correlation. • Two different datasets gave clear support to the proposed novel theory and its hypotheses. - Abstract: A key issue, in order to be able to cope with deliberate or accidental atmospheric releases of hazardous substances, is the ability to reliably predict the individual exposure downstream the source. In many situations, the release time and/or the health relevant exposure time is short compared to mean concentration time scales. In such a case, a significant scatter of exposure levels is expected due to the stochastic nature of turbulence. The problem becomes even more complex when dispersion occurs over urban environments. The present work is the first attempt to approximate on generic terms, the statistical behavior of the abovementioned variability with a beta distribution probability density function (beta-pdf) which has proved to be quite successful. The important issue of the extreme concentration value in beta-pdf seems to be properly addressed by the [5] correlation in which global values of its associated constants are proposed. Two substantially different datasets, the wind tunnel Michelstadt experiment and the field Mock Urban Setting Trial (MUST) experiment gave clear support to the proposed novel theory and its hypotheses. In addition, the present work can be considered as basis for further investigation and model refinements.

  13. Short-term effects of ambient air pollution on pediatric outpatient visits for respiratory diseases in Yichang city, China

    International Nuclear Information System (INIS)

    Liu, Yuewei; Xie, Shuguang; Yu, Qing; Huo, Xixiang; Ming, Xiaoyan; Wang, Jing; Zhou, Yun; Peng, Zhe; Zhang, Hai; Cui, Xiuqing; Xiang, Hua; Huang, Xiji; Zhou, Ting; Chen, Weihong; Shi, Tingming

    2017-01-01

    Previous studies have suggested that short-term exposure to ambient air pollution was associated with pediatric hospital admissions and emergency room visits for certain respiratory diseases; however, there is limited evidence on the association between short-term air pollution exposure and pediatric outpatient visits. Our aim was to quantitatively assess the short-term effects of ambient air pollution on pediatric outpatient visits for respiratory diseases. We conducted a time-series study in Yichang city, China between Jan 1, 2014 and Dec 31, 2015. Daily counts of pediatric respiratory outpatient visits were collected from 3 large hospitals, and then linked with air pollution data from 5 air quality monitoring stations by date. We used generalized additive Poisson models to conduct linear and nonlinear exposure-response analyses between air pollutant exposures and pediatric respiratory outpatient visits, adjusting for seasonality, day of week, public holiday, temperature, and relative humidity. Each interquartile range (IQR) increase in PM 2.5 (lag 0), PM 10 (lag 0), NO 2 (lag 0), CO (lag 0), and O 3 (lag 4) concentrations was significantly associated with a 1.91% (95% CI: 0.60%, 3.23%), 2.46% (1.09%, 3.85%), 1.88% (0.49%, 3.29%), 2.00% (0.43%, 3.59%), and 1.91% (0.45%, 3.39%) increase of pediatric respiratory outpatient visits, respectively. Similarly, the nonlinear exposure-response analyses showed monotonic increases of pediatric respiratory outpatient visits by increasing air pollutant exposures, though the associations for NO 2 and CO attenuated at higher concentrations. These associations were unlikely modified by season. We did not observe significant association for SO 2 exposure. Our results suggest that short-term exposures to PM 2.5 , PM 10 , NO 2 , CO, and O 3 may account for increased risk of pediatric outpatient visits for respiratory diseases, and emphasize the needs for reduction of air pollutant exposures for children. - Highlights: • PM 2

  14. Evaluation of Drinking Water Disinfectant Byproducts Compliance Data as an Indirect Measure for Short-Term Exposure in Humans.

    Science.gov (United States)

    Parvez, Shahid; Frost, Kali; Sundararajan, Madhura

    2017-05-20

    In the absence of shorter term disinfectant byproducts (DBPs) data on regulated Trihalomethanes (THMs) and Haloacetic acids (HAAs), epidemiologists and risk assessors have used long-term annual compliance (LRAA) or quarterly (QA) data to evaluate the association between DBP exposure and adverse birth outcomes, which resulted in inconclusive findings. Therefore, we evaluated the reliability of using long-term LRAA and QA data as an indirect measure for short-term exposure. Short-term residential tap water samples were collected in peak DBP months (May-August) in a community water system with five separate treatment stations and were sourced from surface or groundwater. Samples were analyzed for THMs and HAAs per the EPA (U.S. Environmental Protection Agency) standard methods (524.2 and 552.2). The measured levels of total THMs and HAAs were compared temporally and spatially with LRAA and QA data, which showed significant differences ( p water stations showed higher levels than LRAA or QA. Significant numbers of samples in surface water stations exceeded regulatory permissible limits: 27% had excessive THMs and 35% had excessive HAAs. Trichloromethane, trichloroacetic acid, and dichloroacetic acid were the major drivers of variability. This study suggests that LRAA and QA data are not good proxies of short-term exposure. Further investigation is needed to determine if other drinking water systems show consistent findings for improved regulation.

  15. Prenatal exposure to ethanol during late gestation facilitates operant self-administration of the drug in 5-day-old rats.

    Science.gov (United States)

    Miranda-Morales, Roberto Sebastián; Nizhnikov, Michael E; Spear, Norman E

    2014-02-01

    Prenatal ethanol exposure modifies postnatal affinity to the drug, increasing the probability of ethanol use and abuse. The present study tested developing rats (5-day-old) in a novel operant technique to assess the degree of ethanol self-administration as a result of prenatal exposure to low ethanol doses during late gestation. On a single occasion during each of gestational days 17-20, pregnant rats were intragastrically administered ethanol 1 g/kg, or water (vehicle). On postnatal day 5, pups were tested on a novel operant conditioning procedure in which they learned to touch a sensor to obtain 0.1% saccharin, 3% ethanol, or 5% ethanol. Immediately after a 15-min training session, a 6-min extinction session was given in which operant behavior had no consequence. Pups were positioned on a smooth surface and had access to a touch-sensitive sensor. Physical contact with the sensor activated an infusion pump, which served to deliver an intraoral solution as reinforcement (Paired group). A Yoked control animal evaluated at the same time received the reinforcer when its corresponding Paired pup touched the sensor. Operant behavior to gain access to 3% ethanol was facilitated by prenatal exposure to ethanol during late gestation. In contrast, operant learning reflecting ethanol reinforcement did not occur in control animals prenatally exposed to water only. Similarly, saccharin reinforcement was not affected by prenatal ethanol exposure. These results suggest that in 5-day-old rats, prenatal exposure to a low ethanol dose facilitates operant learning reinforced by intraoral administration of a low-concentration ethanol solution. This emphasizes the importance of intrauterine experiences with ethanol in later susceptibility to drug reinforcement. The present operant conditioning technique represents an alternative tool to assess self-administration and seeking behavior during early stages of development. Published by Elsevier Inc.

  16. A randomly-controlled study on the cardiac function at the early stage of return to the plains after short-term exposure to high altitude.

    Directory of Open Access Journals (Sweden)

    Qiquan Zhou

    Full Text Available High altitude acclimatization and adaptation mechanisms have been well clarified, however, high altitude de-adaptation mechanism remains unclear. In this study, we conducted a controlled study on cardiac functions in 96 healthy young male who rapidly entered the high altitude (3700 m and returned to the plains (1500 m after 50 days. Ninety eight healthy male who remained at low altitude were recruited as control group. The mean pulmonary arterial pressure (mPAP, left ventricular ejection fraction (LVEF, left ventricular fraction shortening (LVFS, cardiac function index (Tei index were tested. Levels of serum creatine kinase isoform MB (CK-MB, lactate dehydrogenase isoenzyme-1 (LDH-1, endothelin-1 (ET-1, nitrogen oxide (NO, serum hypoxia-inducible factor-1α (HIF-1α, 8-iso-prostaglandin F(2α (8-iso PGF(2α, superoxide dismutase (SOD and malonaldehyde (MDA were measured at an altitude of 3700 m and 1500 m respectively. The results showed that after short-term exposure to high altitude mPAP and Tei index increased significantly, while LVEF and LVFS decreased significantly. These changes were positively correlated with altitude. On the 15(th day after the subjects returned to low altitude, mPAP, LVEF and LVFS levels returned to the same level as those of the control subjects, but the Tei index in the returned subjects was still significantly higher than that in the control subjects (P<0.01. We also found that changes in Tei index was positively correlated with mPAP, ET-1, HIF-1α and 8-iso PGF(2α levels, and negatively correlated with the level of NO, LVEF, LVFS, CK-MB and LDH-1. These findings suggest that cardiac function de-adapts when returning to the plains after short-term exposure to high altitude and the function recovery takes a relatively long time.

  17. Short-Term Effects of Nose-Only Cigarette Smoke Exposure on Glutathione Redox Homeostasis, Cytochrome P450 1A1/2 and Respiratory Enzyme Activities in Mice Tissues

    Directory of Open Access Journals (Sweden)

    Haider Raza

    2013-05-01

    Full Text Available Background/Aims: The components of cigarette smoke (CS have been implicated in the development of cancer as well as in cardiopulmonary diseases. We have previously reported increased oxidative stress in rat tissues induced by tobacco-specific toxins nicotine and 4-(N-methyl-N-nitrosamino-1-(3-pyridyl-1-butanone (NNK. Recently, we have also shown increased oxidative stress and associated inflammatory responses in various tissues after exposure to cigarette smoke. Methods: In this study, we have further investigated the effects of nose-only cigarette smoke exposure on mitochondrial functions and glutathione-dependent redox metabolism in tissues of BALB/C mice. Liver, kidney, heart and lung tissues were analyzed for oxidative stress, glutathione (GSH and cytochrome P450 dependent enzyme activities and mitochondrial functions after exposure to smoke generated by 9 cigarettes/day for 4 days. Control mice were exposed to air only. Results: An increase in oxidative stress as observed by increased production of reactive oxygen species (ROS and altered GSH metabolism was apparent in all the tissues, but lung and heart appeared to be the main targets. Increased expression and activity of CYP450 1A1 and 1A2 were also observed in the tissues after exposure to cigarette smoke. Mitochondrial respiratory dysfunction in the tissues, as observed by alterations in the activities of Complex I and IV enzymes, was also observed after exposure to cigarette smoke. SDS-PAGE and Western blot results also indicate that alterations in the expression of enzyme proteins were in accordance with the changes in their catalytic functions. Conclusion: These results suggest that even short term exposure of cigarette smoke have adverse effects on mitochondrial functions and redox homeostasis in tissues which may progress to further complications associated with chronic smoking.

  18. NMDA receptor activation upstream of methyl farnesoate signaling for short day-induced male offspring production in the water flea, Daphnia pulex.

    Science.gov (United States)

    Toyota, Kenji; Miyakawa, Hitoshi; Yamaguchi, Katsushi; Shigenobu, Shuji; Ogino, Yukiko; Tatarazako, Norihisa; Miyagawa, Shinichi; Iguchi, Taisen

    2015-03-14

    The cladoceran crustacean Daphnia pulex produces female offspring by parthenogenesis under favorable conditions, but in response to various unfavorable external stimuli, it produces male offspring (environmental sex determination: ESD). We recently established an innovative system for ESD studies using D. pulex WTN6 strain, in which the sex of the offspring can be controlled simply by changes in the photoperiod: the long-day and short-day conditions can induce female and male offspring, respectively. Taking advantage of this system, we demonstrated that de novo methyl farnesoate (MF) synthesis is necessary for male offspring production. These results indicate the key role of innate MF signaling as a conductor between external environmental stimuli and the endogenous male developmental pathway. Despite these findings, the molecular mechanisms underlying up- and downstream signaling of MF have not yet been well elucidated in D. pulex. To elucidate up- and downstream events of MF signaling during sex determination processes, we compared the transcriptomes of daphnids reared under the long-day (female) condition with short-day (male) and MF-treated (male) conditions. We found that genes involved in ionotropic glutamate receptors, known to mediate the vast majority of excitatory neurotransmitting processes in various organisms, were significantly activated in daphnids by the short-day condition but not by MF treatment. Administration of specific agonists and antagonists, especially for the N-methyl-D-aspartic acid (NMDA) receptor, strongly increased or decreased, respectively, the proportion of male-producing mothers. Moreover, we also identified genes responsible for male production (e.g., protein kinase C pathway-related genes). Such genes were generally shared between the short-day reared and MF-treated daphnids. We identified several candidate genes regulating ESD which strongly suggests that these genes may be essential factors for male offspring production as an

  19. Anatase titanium dioxide nanoparticles in mice: evidence for induced structural and functional sperm defects after short-, but not long-, term exposure

    Directory of Open Access Journals (Sweden)

    Michelle A Smith

    2015-04-01

    Full Text Available Titanium dioxide (TiO 2 nanoparticles (TNPs are widely used commercially and exist in a variety of products. To determine if anatase TNPs (ATNPs in doses smaller than previously used reach the scrotum after entry in the body at a distant location and induce sperm defects, 100% ATNP (2.5 or 5 mg kg−1 body weight was administered intraperitoneally to adult males for three consecutive days, followed by sacrifice 1, 2, 3, or 5 weeks later (long- or 24, 48 or 120 h (short-term exposure. Transmission electron microscopy revealed the presence of ANTP in scrotal adipose tissues collected 120 h postinjection when cytokine evaluation showed an inflammatory response in epididymal tissues and fluid. At 120 h and up to 3 weeks postinjection, testicular histology revealed enlarged interstitial spaces. Significantly increased numbers of terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling-positive (apoptotic germ (P = 0.002 and interstitial space cells (P = 0.04 were detected in treated males. Caudal epididymal sperm from the short-term, but not a long-term, arm showed significantly (P < 0.001 increased frequencies of flagellar abnormalities, excess residual cytoplasm (ERC, and unreacted acrosomes in treated versus controls (dose-response relationship. A novel correlation between ERC and unreacted acrosomes was uncovered. At 120 h, there were significant decreases in hyperactivated motility (P < 0.001 and mitochondrial membrane potential (P < 0.05, and increased reactive oxygen species levels (P < 0.00001 in treated versus control sperm. These results indicate that at 4-8 days postinjection, ANTP induce structural and functional sperm defects associated with infertility, and DNA damage via oxidative stress. Sperm defects were transient as they were not detected 10 days to 5 weeks postinjection.

  20. Anatase titanium dioxide nanoparticles in mice: evidence for induced structural and functional sperm defects after short-, but not long-, term exposure

    Science.gov (United States)

    Smith, Michelle A; Michael, Rowan; Aravindan, Rolands G; Dash, Soma; Shah, Syed I; Galileo, Deni S; Martin-DeLeon, Patricia A

    2015-01-01

    Titanium dioxide (TiO2) nanoparticles (TNPs) are widely used commercially and exist in a variety of products. To determine if anatase TNPs (ATNPs) in doses smaller than previously used reach the scrotum after entry in the body at a distant location and induce sperm defects, 100% ATNP (2.5 or 5 mg kg−1 body weight) was administered intraperitoneally to adult males for three consecutive days, followed by sacrifice 1, 2, 3, or 5 weeks later (long-) or 24, 48 or 120 h (short-term exposure). Transmission electron microscopy revealed the presence of ANTP in scrotal adipose tissues collected 120 h postinjection when cytokine evaluation showed an inflammatory response in epididymal tissues and fluid. At 120 h and up to 3 weeks postinjection, testicular histology revealed enlarged interstitial spaces. Significantly increased numbers of terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labeling-positive (apoptotic) germ (P = 0.002) and interstitial space cells (P = 0.04) were detected in treated males. Caudal epididymal sperm from the short-term, but not a long-term, arm showed significantly (P < 0.001) increased frequencies of flagellar abnormalities, excess residual cytoplasm (ERC), and unreacted acrosomes in treated versus controls (dose-response relationship). A novel correlation between ERC and unreacted acrosomes was uncovered. At 120 h, there were significant decreases in hyperactivated motility (P < 0.001) and mitochondrial membrane potential (P < 0.05), and increased reactive oxygen species levels (P < 0.00001) in treated versus control sperm. These results indicate that at 4–8 days postinjection, ANTP induce structural and functional sperm defects associated with infertility, and DNA damage via oxidative stress. Sperm defects were transient as they were not detected 10 days to 5 weeks postinjection. PMID:25370207

  1. Short- and long-term behavioral effects of exposure to 21%, 40% and 100% oxygen after perinatal hypoxia-ischemia in the rat.

    Science.gov (United States)

    Woodworth, K Nina; Palmateer, Julie; Swide, Joseph; Grafe, Marjorie R

    2011-10-01

    Until recently, supplementation with 100% oxygen was standard therapy for newborns who required resuscitation at birth or suffered later hypoxic-ischemic events. Exposure to high concentrations of oxygen, however, may worsen oxidative stress induced by ischemic injury. In this study we investigated the short- and long-term behavioral outcomes in rats that had undergone hypoxic-ischemic brain injury on postnatal day 7, followed by 2h exposure to 21%, 40%, or 100% oxygen, compared to normal controls. There were no differences in the development of walking, head lifting and righting reflexes from postnatal days 9 to 15. Cliff avoidance showed some abnormal responses in the H21 animals. From postnatal days 28 to 56, three tests of sensorimotor coordination were performed weekly: ledged tapered beam, cylinder, and bilateral tactile stimulation. The ledged tapered beam test without prior training of animals was sensitive to injury, but did not distinguish between treatment groups. The cylinder test showed a greater use of the unimpaired limb in female 21% and 40% oxygen groups compared to controls. Performance in both cylinder and the beam tests showed a correlation with the degree of brain injury. The bilateral tactile stimulation test showed that the male 21% oxygen groups had worse sensory asymmetry than male 40% or 100% oxygen groups, but was not statistically significantly different from controls. We thus found a minor benefit to post-hypoxia-ischemic treatment with 100% and 40% oxygen compared to 21% in one test of early motor skills. Our results for long-term sensorimotor behavior, however, showed conflicting results, however, as males treated with 40% or 100% oxygen had less sensory asymmetry (better performance) in the bilateral tactile stimulation test than males treated with 21% oxygen, while females had impaired motor performance in the cylinder test with both 21% and 40% oxygen. Copyright © 2011 ISDN. Published by Elsevier Ltd. All rights reserved.

  2. Exposure to Pb, Cd, and As mixtures potentiates the production of oxidative stress precursors: 30-day, 90-day, and 180-day drinking water studies in rats.

    Science.gov (United States)

    Whittaker, Margaret H; Wang, Gensheng; Chen, Xue-Qing; Lipsky, Michael; Smith, Donald; Gwiazda, Roberto; Fowler, Bruce A

    2011-07-15

    Exposure to chemical mixtures is a common and important determinant of toxicity and is of particular concern due to their appearance in sources of drinking water. Despite this, few in vivo mixture studies have been conducted to date to understand the health impact of chemical mixtures compared to single chemicals. Interactive effects of lead (Pb), cadmium (Cd) and arsenic (As) were evaluated in 30-, 90-, and 180-day factorial design drinking water studies in rats designed to test the hypothesis that ingestion of such mixtures at individual component Lowest-Observed-Effect-Levels (LOELs) results in increased levels of the pro-oxidant delta aminolevulinic acid (ALA), iron, and copper. LOEL levels of Pb, Cd, and As mixtures resulted in the increased presence of mediators of oxidative stress such as ALA, copper, and iron. ALA increases were followed by statistically significant increases in kidney copper in the 90- and 180-day studies. Statistical evidence of interaction was identified for six biologically relevant variables: blood delta aminolevulinic acid dehydratase (ALAD), kidney ALAD, urinary ALA, urinary iron, kidney iron, and kidney copper. The current investigations underscore the importance of considering interactive effects that common toxic agents such as Pb, Cd, and As may have upon one another at low-dose levels. The interactions between known toxic trace elements at biologically relevant concentrations shown here demonstrate a clear need to rigorously review methods by which national/international agencies assess health risks of chemicals, since exposures may commonly occur as complex mixtures. Copyright © 2011. Published by Elsevier Inc.

  3. Radiation exposure and disease questionnaires of early entrants after the Hiroshima bombing

    International Nuclear Information System (INIS)

    Imanaka, T.; Endo, S.; Kawano, N.; Tanaka, K.

    2012-01-01

    It is popularly known that people who entered into the ground-zero area shortly after the atomic bombings in Hiroshima and Nagasaki suffered from various syndromes similar to acute radiation effects. External exposures from neutron-induced radionuclides in soil have recently been reassessed based on DS02 calculations as functions of both distance from the hypo-centres and elapsed time after the explosions. Significant exposure due to induced radiation can be determined for those who entered the area within 1000 m from the hypo-centres shortly after the bombing. Although it was impossible to track the action of each of the survivors over the days or weeks following the bombings in order to make reliable dose estimates for their exposures to soil activation or fallout, four individuals among those early entrants were investigated here to describe useful information of what happened shortly after the bombing. (authors)

  4. Short-term study of the uptake of PrPSc by the Peyer’s patches in hamsters after oral exposure to scrapie

    DEFF Research Database (Denmark)

    Bergström, Ann-Louise; Jensen, Tim Kåre; Heegaard, Peter M. H.

    2006-01-01

    The disease-associated prion protein (PrPSc) has been detected in the ileal Peyer's patches of lambs as early as one week after oral exposure to scrapie. In hamsters, the earliest reported time of PrPSc detection in the Peyer's patches after oral exposure to scrapie is 69 days post-infection. To ......The disease-associated prion protein (PrPSc) has been detected in the ileal Peyer's patches of lambs as early as one week after oral exposure to scrapie. In hamsters, the earliest reported time of PrPSc detection in the Peyer's patches after oral exposure to scrapie is 69 days post...

  5. Short-term exposure to gold nanoparticle suspension impairs swimming behavior in a widespread calanoid copepod.

    Science.gov (United States)

    Michalec, François-Gaël; Holzner, Markus; Barras, Alexandre; Lacoste, Anne-Sophie; Brunet, Loïc; Lee, Jae-Seong; Slomianny, Christian; Boukherroub, Rabah; Souissi, Sami

    2017-09-01

    Calanoid copepods play an important role in the functioning of marine and brackish ecosystems. Information is scarce on the behavioral toxicity of engineered nanoparticles to these abundant planktonic organisms. We assessed the effects of short-term exposure to nonfunctionalized gold nanoparticles on the swimming behavior of the widespread estuarine copepod Eurytemora affinis. By means of three-dimensional particle tracking velocimetry, we reconstructed the trajectories of males, ovigerous and non-ovigerous females. We quantified changes in their swimming activity and in the kinematics and geometrical properties of their motion, three important descriptors of the motility patterns of zooplankters. In females, exposure to gold nanoparticles in suspension (11.4 μg L -1 ) for 30 min caused depressed activity and lower velocity and acceleration, whereas the same exposure caused minimal effects in males. This response differs clearly from the hyperactive behavior that is commonly observed in zooplankters exposed to pollutants, and from the generally lower sensitivity of female copepods to toxicants. Accumulation of gold nanoparticles on the external appendages was not observed, precluding mechanical effects. Only very few nanoparticles appeared sporadically in the inner part of the gut in some samples, either as aggregates or as isolated nanoparticles, which does not suggest systemic toxicity resulting from pronounced ingestion. Hence, the precise mechanisms underlying the behavioral toxicity observed here remain to be elucidated. These results demonstrate that gold nanoparticles can induce marked behavioral alterations at very low concentration and short exposure duration. They illustrate the applicability of swimming behavior as a suitable and sensitive endpoint for investigating the toxicity of nanomaterials present in estuarine and marine environments. Changes in swimming behavior may impair the ability of planktonic copepods to interact with their environment

  6. Gas-phase organics in environmental tobacco smoke: 2. Exposure-relevant emission factors and indirect exposures from habitual smoking

    Science.gov (United States)

    Singer, Brett C.; Hodgson, Alfred T.; Nazaroff, William W.

    Sorption of emitted gas-phase organic compounds onto material surfaces affects environmental tobacco smoke (ETS) composition and exposures indoors. We have introduced a new metric, the exposure relevant emission factor (EREF) that accounts for sorptive uptake and reemission to give the mass of individual ETS constituents available for exposure over a day in which smoking occurs. This paper describes month-long experiments to investigate sorption effects on EREFs and potential ETS exposures under habitual smoking conditions. Cigarettes were smoked in a 50-m 3 furnished room over a 3-h period 6-7 days per week, with continuous ventilation at 0.3, 0.6, or 2.1 h -1. Organic gas concentrations were measured every few days over 4-h "smoking", 10-h "post-smoking" and 10-h "background" periods. Concentration patterns of volatile ETS components including 1,3-butadiene, benzene and acrolein were similar to those calculated for a theoretical non-sorbing tracer, indicating limited sorption. Concentrations of ETS tracers, e.g. 3-ethenylpyridine (3-EP) and nicotine, and lower volatility toxic air contaminants including phenol, cresols, and naphthalene increased as experiments progressed, indicating mass accumulation on surfaces and higher desorption rates. Daily patterns stabilized after week 2, yielding a steady daily cycle of ETS concentrations associated with habitual smoking. EREFs for sorbing compounds were higher under steady cycle versus single-day smoking conditions by ˜50% for 3-EP, and by 2-3 times for nicotine, phenol, cresols, naphthalene, and methylnaphthalenes. Our results provide relevant information about potential indirect exposures from residual ETS (non-smoker enters room shortly after smoker finishes) and from reemission, and their importance relative to direct exposures (non-smoker present during smoking). Under the conditions examined, indirect exposures accounted for a larger fraction of total potential exposures for sorbing versus non-sorbing compounds

  7. Characterization of new eye drops with choline salicylate and assessment of their irritancy by in vitro short time exposure tests.

    Science.gov (United States)

    Wroblewska, Katarzyna; Kucinska, Małgorzata; Murias, Marek; Lulek, Janina

    2015-09-01

    The aim of our study was to examine the irritation potential of new eye drops containing 2% choline salicylate (CS) as an active pharmaceutical ingredient (API) and various polymers increasing eye drop viscosity (hydroxyethylcellulose, hydroxypropyl methylcellulose, methylcellulose, polyvinyl alcohol, polyvinylpyrrolidone). The standard method for assessing the potential of irritating substances has been the Draize rabbit eye test. However the European Centre for Validation of Alternative Methods and the Coordinating Committee for Validation of Alternative Methods recommend, short time exposure (STE) in vitro tests as an alternative method for assessing eye irritation. The eye irritation potential was determined using cytotoxicity test methods for rabbit corneal cell line (SIRC) after 5 min exposure. The viability of cells was determined using two cytotoxicity assays: MTT and Neutral Red Uptake. According to the irritation rankings for the short time exposure test, all tested eye drops are classified as non-irritating (cell viability >70%).

  8. Effects of 108 Days Tritium Exposure on UHMW-PE, PTFE, and Vespel(R)

    International Nuclear Information System (INIS)

    Clark, E.A.

    2003-01-01

    Samples of three polymers, Ultra-High Molecular Weight Polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE), also known as Teflon(R), and Vespel(R) polyimide were exposed to 1 atmosphere of tritium gas at ambient temperature for 108 days. Sample mass and size measurements to calculate density, spectra-colorimetry, dynamic mechanical analysis (DMA), and Fourier-transform infrared spectroscopy (FT-IR) were employed to characterize the effects of this exposure on these samples. This technical report is the first report from this research program

  9. Quantifying differences in responses of aquatic insects to trace metal exposure in field studies and short-term stream mesocosm experiments

    Science.gov (United States)

    Iwasaki, Yuichi; Schmidt, Travis S.; Clements, William H.

    2018-01-01

    Characterizing macroinvertebrate taxa as either sensitive or tolerant is of critical importance for investigating impacts of anthropogenic stressors in aquatic ecosystems and for inferring causality. However, our understanding of relative sensitivity of aquatic insects to metals in the field and under controlled conditions in the laboratory or mesocosm experiments is limited. In this study, we compared the response of 16 lotic macroinvertebrate families to metals in short-term (10-day) stream mesocosm experiments and in a spatially extensive field study of 154 Colorado streams. Comparisons of field and mesocosm-derived EC20 (effect concentration of 20%) values showed that aquatic insects were generally more sensitive to metals in the field. Although the ranked sensitivity to metals was similar for many families, we observed large differences between field and mesocosm responses for some groups (e.g., Baetidae and Heptageniidae). These differences most likely resulted from the inability of short-term experiments to account for factors such as dietary exposure to metals, rapid recolonization in the field, and effects of metals on sensitive life stages. Understanding mechanisms responsible for differences among field, mesocosm, and laboratory approaches would improve our ability to predict contaminant effects and establish ecologically meaningful water-quality criteria.

  10. Application of Interval Type-2 Fuzzy Logic System in Short Term Load Forecasting on Special Days

    Directory of Open Access Journals (Sweden)

    Agus Dharma

    2011-05-01

    Full Text Available This paper presents the application of Interval Type-2 fuzzy logic systems (Interval Type-2 FLS in short term load forecasting (STLF on special days, study case in Bali Indonesia. Type-2 FLS is characterized by a concept called footprint of uncertainty (FOU that provides the extra mathematical dimension that equips Type-2 FLS with the potential to outperform their Type-1 counterparts. While a Type-2 FLS has the capability to model more complex relationships, the output of a Type-2 fuzzy inference engine needs to be type-reduced. Type reduction is used by applying the Karnik-Mendel (KM iterative algorithm. This type reduction maps the output of Type-2 FSs into Type-1 FSs then the defuzzification with centroid method converts that Type-1 reduced FSs into a number. The proposed method was tested with the actual load data of special days using 4 days peak load before special days and at the time of special day for the year 2002-2006. There are 20 items of special days in Bali that are used to be forecasted in the year 2005 and 2006 respectively. The test results showed an accurate forecasting with the mean average percentage error of 1.0335% and 1.5683% in the year 2005 and 2006 respectively.

  11. Short day photoperiod protects against acetaminophen-induced ...

    African Journals Online (AJOL)

    Prof. Ogunji

    blood was collected by cardiac puncture for the estimation of liver enzymes activities. Liver ... revealed the protective effects of short photoperiod against acetaminophen-induced hepatotoxicity and lipid .... homogenized in ice cold KCl (100mM) containing. 0.003M ... This was followed by the addition of 1.0ml water and 5.0ml ...

  12. Chronic 14-day exposure to insecticides or methylmercury modulates neuronal activity in primary rat cortical cultures

    NARCIS (Netherlands)

    Dingemans, Milou; Schütte, Marijke G; Wiersma, Daphne M M; de Groot, Aart; van Kleef, Gina; Wijnolts, Fiona; Westerink, Remco

    2016-01-01

    There is an increasing demand for in vitro test systems to detect neurotoxicity for use in chemical risk assessment. In this study, we evaluated the applicability of rat primary cortical cultures grown on multi-well micro-electrode arrays (mwMEAs) to detect effects of chronic 14-day exposure to

  13. Short-term dermal exposure to tannery effluent does not cause behavioral changes in male Swiss mice

    Directory of Open Access Journals (Sweden)

    Bruna de Oliveira Mendes

    2018-02-01

    Full Text Available Tannery is a highly polluting activity due to the waste generated by bovine skin processing. Although there are several studies highlighting the health issues faced by workers exposed to tannery effluent, there are no records of experiments testing the neurobehavioral effects resulting from direct contact with this pollutant. Thus, the aim of the current study is to assess the possible neurobehavioral effects of dermal exposure to tannery effluent on male Swiss mice. Animals were divided in three groups, which were subjected to the same experimental time period and conditions: effluent group - animals in direct contact with tannery effluent (for 20 days; control group - animals in contact with pure water; and dry-control group - animals not exposed to water or to tannery effluent. Neurobehavioral tests started on the 17th experimental day. Results of the elevated plus-maze test (anxiety prediction showed no anxiogenic or anxiolytic effects, memory deficit or depressive symptoms on animals exposed to tannery effluent. Thus, the current results do not support the hypothesis that male Swiss mice dermal exposure to tannery effluents for the same time period and experimental conditions leads to neurobehavioral changes. Therefore, the herein adopted exposure protocol was not good to study the effects of dermal exposure to tannery effluent on the chosen experimental model.

  14. Antioxidant role of inositol hexaphosphate on male rats after short-term exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Mansour, S.Z.; Aly, S.M.E.; Ibrahim, N.K.

    2006-01-01

    This study was conducted to evaluate the potency of Inositol hexaphosphate (IP6) as a natural protective agent against gamma-irradiation induced intracellular free radical such as superoxide anion and hydroxyl radical. Swiss albino rats were gavaged by orally tube with 6 doses (day after day) with IP6 mg/kg body wt) alone or even before exposure the animals to whole body gamma-radiation with single dose of 6 Gy 30 min post the last injection of IP6. Lipid peroxide (LP), Glutathione (GSH) levels and the activity of the antioxidant scavenger enzyme Catalase were estimated in blood, liver, kidney and spleen at day 1 post-irradiation. Some metals concentrations were determined to demonstrate the role of IP6 as chelating agent. Radiation exposure showed marked elevation in LP level accompanied by decline in GSH content and in the activity of related antioxidant enzyme Pretreatment with IP6 potentially reversed the investigated parameters in irradiated rats. It modulated LP, and ameliorated to a great extent GSH content and the activity of Catalase enzyme in blood, liver, kidney and spleen of rats exposed to gamma-irradiation

  15. Biological monitoring of benzene exposure for process operators during ordinary activity in the upstream petroleum industry.

    Science.gov (United States)

    Bråtveit, Magne; Kirkeleit, Jorunn; Hollund, Bjørg Eli; Moen, Bente E

    2007-07-01

    This study characterized the exposure of crude oil process operators to benzene and related aromatics during ordinary activity and investigated whether the operators take up benzene at this level of exposure. We performed the study on a fixed, integrated oil and gas production facility on Norway's continental shelf. The study population included 12 operators and 9 referents. We measured personal exposure to benzene, toluene, ethylbenzene and xylene during three consecutive 12-h work shifts using organic vapour passive dosimeter badges. We sampled blood and urine before departure to the production facility (pre-shift), immediately after the work shift on Day 13 of the work period (post-shift) and immediately before the following work shift (pre-next shift). We also measured the exposure to hydrocarbons during short-term tasks by active sampling using Tenax tubes. The arithmetic mean exposure over the 3 days was 0.042 ppm for benzene (range ethylbenzene and 0.03 ppm for xylene. Full-shift personal exposure was significantly higher when the process operators performed flotation work during the shift versus other tasks. Work in the flotation area was associated with short-term (6-15 min) arithmetic mean exposure to benzene of 1.06 ppm (range 0.09-2.33 ppm). The concentrations of benzene in blood and urine did not differ between operators and referents at any time point. When we adjusted for current smoking in regression analysis, benzene exposure was significantly associated with the post-shift concentration of benzene in blood (P = 0.01) and urine (P = 0.03), respectively. Although these operators perform tasks with relatively high short-term exposure to benzene, the full-shift mean exposure is low during ordinary activity. Some evidence indicates benzene uptake within this range of exposure.

  16. Hemocyte responses of Dreissena polymorpha following a short-term in vivo exposure to titanium dioxide nanoparticles: Preliminary investigations

    Energy Technology Data Exchange (ETDEWEB)

    Couleau, Nicolas; Techer, Didier [Universite de Lorraine, Laboratoire des Interactions Ecotoxicologie, Biodiversite, Ecosystemes (LIEBE), CNRS UMR 7146, IUT Thionville-Yutz, Espace Cormontaigne, Yutz, F-57970 (France); Pagnout, Christophe [Universite de Lorraine, Laboratoire des Interactions Ecotoxicologie, Biodiversite, Ecosystemes (LIEBE), UMR 7146, Campus Bridoux, rue du General Delestraint, Metz, F-57070 (France); International Consortium for the Environmental Implications of Nanotechnology, iCEINT, http://www.i-ceint.org (France); Jomini, Stephane [Universite de Lorraine, Laboratoire des Interactions Ecotoxicologie, Biodiversite, Ecosystemes (LIEBE), UMR 7146, Campus Bridoux, rue du General Delestraint, Metz, F-57070 (France); Foucaud, Laurent; Laval-Gilly, Philippe; Falla, Jairo [Universite de Lorraine, Laboratoire des Interactions Ecotoxicologie, Biodiversite, Ecosystemes (LIEBE), CNRS UMR 7146, IUT Thionville-Yutz, Espace Cormontaigne, Yutz, F-57970 (France); Bennasroune, Amar, E-mail: amar.bennasroune@univ-metz.fr [Universite de Lorraine, Laboratoire des Interactions Ecotoxicologie, Biodiversite, Ecosystemes (LIEBE), CNRS UMR 7146, IUT Thionville-Yutz, Espace Cormontaigne, Yutz, F-57970 (France)

    2012-11-01

    The widespread use of titanium-based nanoparticles and their environmental release may pose a significant risk to aquatic organisms within freshwater ecosystems. Suspension-feeder invertebrates like bivalve molluscs represent a unique target group for nanoparticle toxicology. The aim of this work was to investigate the short-term responses of Dreissena polymorpha hemocytes after in vivo exposure to titanium dioxide nanoparticles (TiO{sub 2} NP). For this purpose, freshwater mussels were exposed to P25 TiO{sub 2} NP at the concentrations of 0.1, 1, 5 and 25 mg/L during 24 h. Viability, phagocytosis activity and mitogen activated protein kinase (MAPK) phosphorylation level of ERK 1/2 and p38 in hemocytes extracted from exposed mussels were compared to those from control specimens. Results demonstrated an inhibition of the phagocytosis activity after exposure to TiO{sub 2} NP at 0.1 and 1 mg/L. Similar trends, albeit less pronounced, were reported for higher concentrations of NP. Transmission electron microscopy showed for the first time the internalization of TiO{sub 2} NP into Dreissena polymorpha hemocytes. Besides, exposure to NP increased the ERK 1/2 phosphorylation levels in all treatments. Concerning the phosphorylation level of p38, only exposures to 5 and 25 mg/L of NP induced significant p38 activation in comparison to that of the control. Finally, these short-term effects observed at environmentally relevant concentrations highlighted the need for further studies concerning ecotoxicological evaluation of nanoparticle release into an aquatic environment. -- Highlights: Black-Right-Pointing-Pointer Phagocytosis inhibition at TiO{sub 2} NP exposure concentrations of 0.1 and 1 mg/L. Black-Right-Pointing-Pointer Internalization of TiO{sub 2} NP in freshwater mussel hemocytes. Black-Right-Pointing-Pointer Increased phosphorylation level of p38 and ERK 1/2 after in vivo exposure to TiO{sub 2} NP.

  17. Age-Specific Associations Between Violence Exposure and Past 30-Day Marijuana and Alcohol Use.

    Science.gov (United States)

    Goldstick, Jason E; Heinze, Justin E; Stoddard, Sarah A; Cunningham, Rebecca M; Zimmerman, Marc A

    2018-04-23

    Using data from a cohort study of students at risk for high school dropout, we examined associations between violence exposure and past 30-day alcohol and marijuana use. We used varying-coefficient regression with person-level fixed effects to estimate how those associations changed within-person across ages approximately 14-23. Generally, violence perpetration was most strongly associated with substance use, within-person. Substance use became increasingly associated with both observed violence and violence perpetration during early/middle adolescence; this increase continued longer into development (age 18+) for alcohol use. Across most of the age range studied here, violence victimization was minimally associated with within-person changes in substance use. Results indicate age-specific associations between violence exposure and alcohol and other drug use, which may be useful for informing prevention strategies. © 2018 Society for Research on Adolescence.

  18. Evaluation of silica nanoparticle toxicity after topical exposure for 90 days

    Directory of Open Access Journals (Sweden)

    Ryu HJ

    2014-12-01

    Full Text Available Hwa Jung Ryu,1,* Nak-won Seong,2,* Byoung Joon So,1 Heung-sik Seo,2 Jun-ho Kim,2 Jeong-Sup Hong,2 Myeong-kyu Park,2 Min-Seok Kim,2 Yu-Ri Kim,3 Kyu-Bong Cho,4 Mu yeb Seo,2 Meyoung-Kon Kim,3 Eun Ho Maeng,2 Sang Wook Son1 1Department of Dermatology, Korea University College of Medicine, Seoul, South Korea; 2Korea Testing and Research Institute, Gyunggi-Do, South Korea; 3Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul, South Korea; 4Department of Clinical Laboratory Science, Shinheung College, Uijeongbu, South Korea *These authors contributed equally to this work Abstract: Silica is a very common material that can be found in both crystalline and amorphous forms. Well-known toxicities of the lung can occur after exposure to the crystalline form of silica. However, the toxicities of the amorphous form of silica have not been thoroughly studied. The majority of in vivo studies of amorphous silica nanoparticles (NPs were performed using an inhalation exposure method. Since silica NPs can be commonly administered through the skin, a study of dermal silica toxicity was necessary to determine any harmful effects from dermal exposures. The present study focused on the results of systemic toxicity after applying 20 nm colloidal silica NPs on rat skin for 90 days, in accordance with the Organization for Economic Cooperation and Development test guideline 411 with a good laboratory practice system. Unlike the inhalation route or gastrointestinal route, the contact of silica NPs through skin did not result in any toxicity or any change in internal organs up to a dose of 2,000 mg/kg in rats. Keywords: silica nanoparticles, toxicity, dermal route

  19. Aqueous exposure to Aroclor 1254 modulates the mitogenic response of Atlantic salmon anterior kidney T-cells: Indications of short- and long-term immunomodulation

    International Nuclear Information System (INIS)

    Iwanowicz, Luke R.; Lerner, Darren T.; Blazer, Vicki S.; McCormick, Stephen D.

    2005-01-01

    Polychlorinated biphenyls (PCBs) exist as persistent organic pollutants in numerous river systems in the United States. Unfortunately, some of these rivers are sites of active Atlantic salmon restoration programs, and polychlorinated biphenyls have been implicated as ancillary factors contributing to failed salmon restoration. Here, we investigate the immediate and chronic effects of intermediate duration aqueous PCB exposure (1 or 10 μg L -1 Aroclor 1254) on the mitogen-stimulated lymphoproliferative response of Atlantic salmon anterior kidney leukocytes (AKLs). A short-term study was designed to examine immunomodulation in Atlantic salmon smolts immediately following 21 days of aqueous exposure, while a long-term study evaluated chronic impacts in the mitogen response in parr 15 months post-exposure as larvae. The proliferative response of AKLs to the mitogens concanavalin A (CON A), phytohemaglutinnin-P (PHA-P), pokeweed mitogen (PWM), and lipopolysaccharide were used as an indice of immunomodulation. The proliferative response to the T-cell mitogens CON A and PHA-P was significantly increased in the 10 μg L -1 group (n = 10; P = 0.043 and 0.002, respectively) immediately following exposure of smolts. Additionally, The PHA-P response was significantly increased in the 1 μg L -1 exposure group (n = 10, P = 0.036). In fish treated as larvae and tested 15 months later, the PHA-P sensitive populations exhibited elevated proliferation in the 1 and 10 μg L -1 groups (n = 12, P -1 treated groups. These results demonstrate an immunomodulatory effect of PCBs on T-cell mitogen sensitive populations of lymphocytes in Atlantic salmon as well as long-term immunomodulation in PHA-P and PWM sensitive populations

  20. Influence of mobile phone traffic on base station exposure of the general public.

    Science.gov (United States)

    Joseph, Wout; Verloock, Leen

    2010-11-01

    The influence of mobile phone traffic on temporal radiofrequency exposure due to base stations during 7 d is compared for five different sites with Erlang data (representing average mobile phone traffic intensity during a period of time). The time periods of high exposure and high traffic during a day are compared and good agreement is obtained. The minimal required measurement periods to obtain accurate estimates for maximal and average long-period exposure (7 d) are determined. It is shown that these periods may be very long, indicating the necessity of new methodologies to estimate maximal and average exposure from short-period measurement data. Therefore, a new method to calculate the fields at a time instant from fields at another time instant using normalized Erlang values is proposed. This enables the estimation of maximal and average exposure during a week from short-period measurements using only Erlang data and avoids the necessity of long measurement times.

  1. Dynamic adaptation of cardiac baroreflex sensitivity to prolonged exposure to microgravity: data from a 16-day spaceflight

    NARCIS (Netherlands)

    Di Rienzo, Marco; Castiglioni, Paolo; Iellamo, Ferdinando; Volterrani, Maurizio; Pagani, Massimo; Mancia, Giuseppe; Karemaker, John M.; Parati, Gianfranco

    2008-01-01

    Di Rienzo M, Castiglioni P, Iellamo F, Volterrani M, Pagani M, Mancia G, Karemaker JM, Parati G. Dynamic adaptation of cardiac baroreflex sensitivity to prolonged exposure to microgravity: data from a 16-day spaceflight. J Appl Physiol 105: 1569-1575, 2008. First published August 28, 2008;

  2. Effects of prolonged exposure to space flight factors for 175 days on lettuce seeds

    International Nuclear Information System (INIS)

    Nevzgodina, L.V.; Maximova, E.N.; Akatov, Yu.A.

    1981-01-01

    The effects of prolonged (up to 175 days) exposure of Lactuca sativa seeds to space flight factors, including primary cosmic radiation heavy ions have been studied. The data obtained evidence a significant fourfold increase of spontaneous mutagenesis in seeds both with regard to the total number of aberrant cells as well as the formation of single cells with multiple aberrations. Comparison of the present experiment with earlier works shows that the frequency of such aberrations increases with the duration of the flight

  3. Circadian variation of melatonin, light exposure, and diurnal preference in day and night shift workers of both sexes.

    Science.gov (United States)

    Papantoniou, Kyriaki; Pozo, Oscar J; Espinosa, Ana; Marcos, Josep; Castaño-Vinyals, Gemma; Basagaña, Xavier; Ribas, Ferran Calduch; Mirabent, Joan; Martín, Jordi; Carenys, Gemma; Martín, Celia Reyes; Middleton, Benita; Skene, Debra J; Kogevinas, Manolis

    2014-07-01

    Light-at-night has been shown in experimental studies to disrupt melatonin production but this has only partly been confirmed in studies of night shift workers. In this cross-sectional study, we examined the circadian variation of melatonin in relation to shift status, individual levels of light-at-night exposure, and diurnal preference, an attribute reflecting personal preference for activity in the morning or evening. One hundred and seventeen workers (75 night and 42 day) of both sexes, ages 22 to 64 years, were recruited from four companies. Participants collected urine samples from all voids over 24 hours and wore a data logger continuously recording their light exposure. Sociodemographic, occupational, lifestyle, and diurnal preference information were collected by interview. Concentrations of urinary 6-sulfatoxymelatonin (aMT6s), the main melatonin metabolite, were measured. Mean aMT6s levels were lower in night [10.9 ng/mg creatinine/hour; 95% confidence interval (CI), 9.5-12.6] compared with day workers (15.4; 95% CI, 12.3-19.3). The lowest aMT6s levels were observed in night workers with morning preference (6.4; 95% CI, 3.0-13.6). Peak time of aMT6s production occurred 3 hours later in night (08:42 hour, 95% CI, 07:48-09:42) compared with day workers (05:36 hour, 95% CI, 05:06-06:12). Phase delay was stronger among subjects with higher light-at-night exposure and number of nights worked. Night shift workers had lower levels and a delay in peak time of aMT6s production over a 24-hour period. Differences were modified by diurnal preference and intensity of light-at-night exposure. Night shift work affects levels and timing of melatonin production and both parameters may relate to future cancer risk. ©2014 American Association for Cancer Research.

  4. Ecologically-relevant exposure to methylmercury during early development does not affect adult phenotype in zebra finches (Taeniopygia guttata).

    Science.gov (United States)

    Morran, Spencer A M; Elliott, John E; Young, Jessica M L; Eng, Margaret L; Basu, Niladri; Williams, Tony D

    2018-04-01

    Methylmercury causes behavioural and reproductive effects in adult mammals via early developmental exposure. Similar studies in birds are limited and mostly focussed on aquatic systems, but recent work has reported high blood mercury concentrations in terrestrial, passerine songbirds. We used the zebra finch (Taeniopygia guttata) as a model to explore the long-term effects of early developmental exposure to methylmercury exposure. Chicks were dosed orally with either the vehicle control, 0.0315 µg Hg/g bw/day, or 0.075 µg Hg/g bw/day throughout the nestling period (days 1-21 post-hatching). We then measured (a) short-term effects on growth, development, and behaviour (time to self-feeding, neophobia) until 30 days of age (independence), and (b) long-term effects on courtship behaviour and song (males) and reproduction (females) once methylmercury-exposed birds reached sexual maturity (90 days post-hatching). High methylmercury treated birds had mean blood mercury of 0.734 ± 0.163 µg/g at 30 days post-hatching, within the range of values reported for field-sampled songbirds at mercury contaminated sites. However, there were no short-term effects of treatment on growth, development, and behaviour of chicks, and no long-term effects on courtship behaviour and song in males or reproductive performance in females. These results suggest that the nestling period is not a critical window for sensitivity to mercury exposure in zebra finches. Growing nestlings can reduce blood mercury levels through somatic growth and depuration into newly growing feathers, and as a result they might actually be less susceptible compared to adult birds receiving the same level of exposure.

  5. Short-term exposure and long-term consequences of neonatal exposure to Δ(9)-tetrahydrocannabinol (THC) and ibuprofen in mice.

    Science.gov (United States)

    Philippot, Gaëtan; Nyberg, Fred; Gordh, Torsten; Fredriksson, Anders; Viberg, Henrik

    2016-07-01

    Both Δ(9)-tetrahydrocannabinol (THC) and ibuprofen have analgesic properties by interacting with the cannabinoid receptor type 1 (CB1R) and the cyclooxygenase (COX) systems, respectively. Evaluation of these analgesics is important not only clinically, since they are commonly used during pregnancy and lactation, but also to compare them with acetaminophen, with a known interaction with both CB1R and the COX systems. Short-term exposure of neonatal rodents to acetaminophen during the first weeks of postnatal life, which is comparable with a period from the third trimester of pregnancy to the first years of postnatal life in humans, induces long-term behavioral disturbances. This period, called the brain growth spurt (BGS) and is characterized by series of rapid and fundamental changes and increased vulnerability, peaks around postnatal day (PND) 10 in mice. We therefore exposed male NMRI mice to either THC or ibuprofen on PND 10. At 2 months of age, the mice were subjected to a spontaneous behavior test, consisting of a 60min recording of the variables locomotion, rearing and total activity. Mice exposed to THC, but not ibuprofen, exhibited altered adult spontaneous behavior and habituation capability in a dose-dependent manner. This highlights the potency of THC as a developmental neurotoxicant, since a single neonatal dose of THC was enough to affect adult cognitive function. The lack of effect from ibuprofen also indicates that the previously seen developmental neurotoxicity of acetaminophen is non-COX-mediated. These results might be of importance in future research as well as in the ongoing risk/benefit assessment of THC. Copyright © 2016. Published by Elsevier B.V.

  6. Short-Term Exposure to Air Pollution and Biomarkers of Oxidative Stress: The Framingham Heart Study.

    Science.gov (United States)

    Li, Wenyuan; Wilker, Elissa H; Dorans, Kirsten S; Rice, Mary B; Schwartz, Joel; Coull, Brent A; Koutrakis, Petros; Gold, Diane R; Keaney, John F; Lin, Honghuang; Vasan, Ramachandran S; Benjamin, Emelia J; Mittleman, Murray A

    2016-04-28

    Short-term exposure to elevated air pollution has been associated with higher risk of acute cardiovascular diseases, with systemic oxidative stress induced by air pollution hypothesized as an important underlying mechanism. However, few community-based studies have assessed this association. Two thousand thirty-five Framingham Offspring Cohort participants living within 50 km of the Harvard Boston Supersite who were not current smokers were included. We assessed circulating biomarkers of oxidative stress including blood myeloperoxidase at the seventh examination (1998-2001) and urinary creatinine-indexed 8-epi-prostaglandin F2α (8-epi-PGF2α) at the seventh and eighth (2005-2008) examinations. We measured fine particulate matter (PM2.5), black carbon, sulfate, nitrogen oxides, and ozone at the Supersite and calculated 1-, 2-, 3-, 5-, and 7-day moving averages of each pollutant. Measured myeloperoxidase and 8-epi-PGF2α were loge transformed. We used linear regression models and linear mixed-effects models with random intercepts for myeloperoxidase and indexed 8-epi-PGF2α, respectively. Models were adjusted for demographic variables, individual- and area-level measures of socioeconomic position, clinical and lifestyle factors, weather, and temporal trend. We found positive associations of PM2.5 and black carbon with myeloperoxidase across multiple moving averages. Additionally, 2- to 7-day moving averages of PM2.5 and sulfate were consistently positively associated with 8-epi-PGF2α. Stronger positive associations of black carbon and sulfate with myeloperoxidase were observed among participants with diabetes than in those without. Our community-based investigation supports an association of select markers of ambient air pollution with circulating biomarkers of oxidative stress. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

  7. Digital gene expression analysis in the gills of Ruditapes philippinarum exposed to short- and long-term exposures of ammonia nitrogen.

    Science.gov (United States)

    Cong, Ming; Wu, Huifeng; Cao, Tengfei; Lv, Jiasen; Wang, Qing; Ji, Chenglong; Li, Chenghua; Zhao, Jianmin

    2018-01-01

    Previous study revealed severe toxic effects of ammonia nitrogen on Ruditapes philippinarum including lysosomal instability, disturbed metabolic profiles, gill tissues with damaged structure, and variation of neurotransmitter concentrations. However, the underlying molecular mechanism was not fully understood yet. In the present study, digital gene expression technology (DGE) was applied to globally screen the key genes and pathways involved in the responses to short- and long-term exposures of ammonia nitrogen. Results of DGE analysis indicated that short-term duration of ammonia exposure affected pathways in Dorso-ventral axis formation, Notch signaling, thyroid hormone signaling and protein processing in endoplasmic reticulum. The long-term exposure led to DEGs significantly enriched in gap junction, immunity, signal and hormone transduction, as well as key substance metabolism pathways. Functional research of significantly changed DEGs suggested that the immunity of R. philippinarum was weakened heavily by toxic effects of ammonia nitrogen, as well as neuro-transduction and metabolism of important substances. Taken together, the present study provides a molecular support for the previous results of the detrimental toxicity of ammonia exposure in R. philippinarum, further work will be performed to investigate the specific genes and their certain functions involved in ammonia toxicity to molluscs. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Intermittent, low dose carbon monoxide exposure enhances survival and dopaminergic differentiation of human neural stem cells

    DEFF Research Database (Denmark)

    Dreyer-Andersen, Nanna; Almeida, Ana Sofia; Jensen, Pia

    2018-01-01

    cells constitute an alternative source of cells for transplantation in Parkinson's disease, but efficient protocols for controlled dopaminergic differentiation need to be developed. Short-term, low-level carbon monoxide (CO) exposure has been shown to affect signaling in several tissues, resulting...... in both protection and generation of reactive oxygen species. The present study investigated the effect of CO produced by a novel CO-releasing molecule on dopaminergic differentiation of human neural stem cells. Short-term exposure to 25 ppm CO at days 0 and 4 significantly increased the relative content...... of β-tubulin III-immunoreactive immature neurons and tyrosine hydroxylase expressing catecholaminergic neurons, as assessed 6 days after differentiation. Also the number of microtubule associated protein 2-positive mature neurons had increased significantly. Moreover, the content of apoptotic cells...

  9. Downregulation of immediate-early genes linking to suppression of neuronal plasticity in rats after 28-day exposure to glycidol

    International Nuclear Information System (INIS)

    Akane, Hirotoshi; Saito, Fumiyo; Shiraki, Ayako; Takeyoshi, Masahiro; Imatanaka, Nobuya; Itahashi, Megu; Murakami, Tomoaki; Shibutani, Makoto

    2014-01-01

    We previously found that the 28-day oral toxicity study of glycidol at 200 mg/kg/day in rats resulted in axonopathy in both the central and peripheral nervous systems and aberrations in the late-stage of hippocampal neurogenesis targeting the process of neurite extension. To capture the neuronal parameters in response to glycidol toxicity, these animals were subjected to region-specific global gene expression profiling in four regions of cerebral and cerebellar architectures, followed by immunohistochemical analysis of selected gene products. Expression changes of genes related to axonogenesis and synaptic transmission were observed in the hippocampal dentate gyrus, cingulate cortex and cerebellar vermis at 200 mg/kg showing downregulation in most genes. In the corpus callosum, genes related to growth, survival and functions of glial cells fluctuated their expression. Immunohistochemically, neurons expressing gene products of immediate-early genes, i.e., Arc, Fos and Jun, decreased in their number in the dentate granule cell layer, cingulate cortex and cerebellar vermis. We also applied immunohistochemical analysis in rat offspring after developmental exposure to glycidol through maternal drinking water. The results revealed increases of Arc + neurons at 1000 ppm and Fos + neurons at ≥ 300 ppm in the dentate granule cell layer of offspring only at the adult stage. These results suggest that glycidol suppressed neuronal plasticity in the brain after 28-day exposure to young adult animals, in contrast to the operation of restoration mechanism to increase neuronal plasticity at the adult stage in response to aberrations in neurogenesis after developmental exposure. - Highlights: • Neuronal toxicity parameters after 28-day glycidol treatment were examined in rats. • Region-specific global gene expression profiling was conducted in brain regions. • Cortical tissues downregulated genes on axonogenesis and synaptic transmission. • Cortical tissues decreased

  10. Intact Acquisition and Short-Term Retention of Non-Motor Procedural Learning in Parkinson's Disease.

    Directory of Open Access Journals (Sweden)

    Muriel T N Panouillères

    Full Text Available Procedural learning is a form of memory where people implicitly acquire a skill through repeated practice. People with Parkinson's disease (PD have been found to acquire motor adaptation, a form of motor procedural learning, similarly to healthy older adults but they have deficits in long-term retention. A similar pattern of normal learning on initial exposure with a deficit in retention seen on subsequent days has also been seen in mirror-reading, a form of non-motor procedural learning. It is a well-studied fact that disrupting sleep will impair the consolidation of procedural memories. Given the prevalence of sleep disturbances in PD, the lack of retention on following days seen in these studies could simply be a side effect of this well-known symptom of PD. Because of this, we wondered whether people with PD would present with deficits in the short-term retention of a non-motor procedural learning task, when the test of retention was done the same day as the initial exposure. The aim of the present study was then to investigate acquisition and retention in the immediate short term of cognitive procedural learning using the mirror-reading task in people with PD. This task involved two conditions: one where triads of mirror-inverted words were always new that allowed assessing the learning of mirror-reading skill and another one where some of the triads were presented repeatedly during the experiment that allowed assessing the word-specific learning. People with PD both ON and OFF their normal medication were compared to healthy older adults and young adults. Participants were re-tested 50 minutes break after initial exposure to probe for short-term retention. The results of this study show that all groups of participants acquired and retained the two skills (mirror-reading and word-specific similarly. These results suggest that neither healthy ageing nor the degeneration within the basal ganglia that occurs in PD does affect the mechanisms

  11. Gender differences in blood pressure regulation following artificial gravity exposure

    Science.gov (United States)

    Evans, Joyce; Goswami, Nandu; Kostas, Vladimir; Zhang, Qingguang; Ferguson, Connor; Moore, Fritz; Stenger, Michael, , Dr; Serrador, Jorge; W, Siqi

    Introduction. Before countermeasures to space flight cardiovascular deconditioning are established, gender differences in cardiovascular responses to orthostatic stress, in general, and to orthostatic stress following exposure to artificial gravity (AG), in particular, need to be determined. Our recent determination that a short exposure to AG improved the orthostatic tolerance limit (OTL) of cardiovascularly deconditioned subjects drives the current effort to determine mechanisms of that improvement in men and in women. Methods. We determined the OTL of 9 men and 8 women following a 90 min exposure to AG compared to that following 90 min of head down bed rest (HDBR). On both days (21 days apart), subjects were made hypovolemic (low salt diet plus 20 mg intravenous furosemide) and orthostatic tolerance was determined from a combination of head up tilt and increasing lower body negative pressure until presyncope. Mean values and correlations with OTL were determined for heart rate, blood pressure, stroke volume, cardiac output, total peripheral resistance (Finometer), middle cerebral artery flow velocity (DWL), partial pressure of carbon dioxide (Novametrics) and body segmental impedance (UFI THRIM) at supine baseline, during orthostatic stress to presyncope and at supine recovery. Results. Orthostatic tolerance of these hypovolemic subjects was significantly greater following AG than following HDBR. Exposure to AG increased cardiac output in both men and women and increased stroke volume in women. In addition, AG decreased systolic blood pressure in men, but not women, and increased cerebral flow in women, but not men. In both men and women, AG exposure decreased peripheral resistance and decreased cerebrovascular resistance in women. Men’s heart rate rose more at the end of OTL on their AG, compared to their HDBR, day but women’s fell. Presyncopal stroke volume reached the same level on each day of study for both men and women. Conclusions. In the present

  12. Bioaccumulation and locomotor effects of manganese phosphate/sulfate mixture in Sprague-Dawley rats following subchronic (90 days) inhalation exposure

    International Nuclear Information System (INIS)

    Salehi, Fariba; Krewski, Daniel; Mergler, Donna; Normandin, Louise; Kennedy, Greg; Philippe, Suzanne; Zayed, Joseph

    2003-01-01

    Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic manganese (Mn) compound added to unleaded gasoline in Canada. The primary combustion products of MMT are Mn phosphate, Mn sulfate, and a Mn phosphate/Mn sulfate mixture. Concerns have been raised that the combustion products of MMT containing Mn could be neurotoxic, even at low levels of exposure. The objective of this study is to investigate exposure-response relationships for bioaccumulation and locomotor effects following subchronic inhalation exposure to a mixture of manganese phosphates/sulfate mixture. A control group and three groups of 30 male Sprague-Dawley rats were exposed in inhalation chambers for a period of 13 weeks, 5 days per week, 6 h a day. Exposure concentrations were 3000, 300, and 30 μg/m 3 . At the end of the exposure period, locomotor activity and resting time tests were conducted for 36 h using a computerized autotrack system. Rats were then euthanized by exsanguination and Mn concentrations in different tissues (liver, lung, testis, and kidney) and blood and brain (caudate putamen, globus pallidus, olfactory bulb, frontal cortex, and cerebellum) were determined by neutron activation analysis. Increased manganese concentrations were observed in blood, kidney, lung, testis, and in all brain sections in the highest exposure group. Mn in the lung and in the olfactory bulb were dose dependent. Our data indicate that the olfactory bulb accumulated more Mn than other brain regions following inhalation exposure. Locomotor activity was increased at 3000 μg/m 3 , but no difference was observed in resting time among the exposed groups. At the end of the experiment, rats exposed to 300 and 3000 μg/m 3 exhibited significantly decreased body weight in comparison with the control group. Biochemical profiles also revealed some significant differences in certain parameters, specifically alkaline phospatase, urea, and chlorate

  13. Bioaccumulation and locomotor effects of manganese phosphate/sulfate mixture in Sprague-Dawley rats following subchronic (90 days) inhalation exposure.

    Science.gov (United States)

    Salehi, Fariba; Krewski, Daniel; Mergler, Donna; Normandin, Louise; Kennedy, Greg; Philippe, Suzanne; Zayed, Joseph

    2003-09-15

    Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic manganese (Mn) compound added to unleaded gasoline in Canada. The primary combustion products of MMT are Mn phosphate, Mn sulfate, and a Mn phosphate/Mn sulfate mixture. Concerns have been raised that the combustion products of MMT containing Mn could be neurotoxic, even at low levels of exposure. The objective of this study is to investigate exposure-response relationships for bioaccumulation and locomotor effects following subchronic inhalation exposure to a mixture of manganese phosphates/sulfate mixture. A control group and three groups of 30 male Sprague-Dawley rats were exposed in inhalation chambers for a period of 13 weeks, 5 days per week, 6 h a day. Exposure concentrations were 3000, 300, and 30 microg/m(3). At the end of the exposure period, locomotor activity and resting time tests were conducted for 36 h using a computerized autotrack system. Rats were then euthanized by exsanguination and Mn concentrations in different tissues (liver, lung, testis, and kidney) and blood and brain (caudate putamen, globus pallidus, olfactory bulb, frontal cortex, and cerebellum) were determined by neutron activation analysis. Increased manganese concentrations were observed in blood, kidney, lung, testis, and in all brain sections in the highest exposure group. Mn in the lung and in the olfactory bulb were dose dependent. Our data indicate that the olfactory bulb accumulated more Mn than other brain regions following inhalation exposure. Locomotor activity was increased at 3000 microg/m(3), but no difference was observed in resting time among the exposed groups. At the end of the experiment, rats exposed to 300 and 3000 microg/m(3) exhibited significantly decreased body weight in comparison with the control group. Biochemical profiles also revealed some significant differences in certain parameters, specifically alkaline phospatase, urea, and chlorate.

  14. Revisiting short-term price and volatility dynamics in day-ahead electricity markets with rising wind power

    International Nuclear Information System (INIS)

    Li, Yuanjing

    2015-01-01

    This paper revisits the short-term price and volatility dynamics in day-ahead electricity markets in consideration of an increasing share of wind power, using an example of the Nord Pool day-ahead market and the Danish wind generation. To do so, a GARCH process is applied, and market coupling and the counterbalance effect of hydropower in the Scandinavian countries are additionally accounted for. As results, we found that wind generation weakly dampens spot prices with an elasticity of 0.008 and also reduces price volatility with an elasticity of 0.02 in the Nordic day-ahead market. The results shed lights on the importance of market coupling and interactions between wind power and hydropower in the Nordic system through cross-border exchanges, which play an essential role in price stabilization. Additionally, an EGARCH specification confirms an asymmetric influence of the price innovations, whereby negative shocks produce larger volatility in the Nordic spot market. While considering heavy tails in error distributions can improve model fits significantly, the EGARCH model outperforms the GARCH model on forecast evaluations. (author)

  15. Short-term pre- and post-operative stress prolongs incision-induced pain hypersensitivity without changing basal pain perception.

    Science.gov (United States)

    Cao, Jing; Wang, Po-Kai; Tiwari, Vinod; Liang, Lingli; Lutz, Brianna Marie; Shieh, Kun-Ruey; Zang, Wei-Dong; Kaufman, Andrew G; Bekker, Alex; Gao, Xiao-Qun; Tao, Yuan-Xiang

    2015-12-02

    Chronic stress has been reported to increase basal pain sensitivity and/or exacerbate existing persistent pain. However, most surgical patients have normal physiological and psychological health status such as normal pain perception before surgery although they do experience short-term stress during pre- and post-operative periods. Whether or not this short-term stress affects persistent postsurgical pain is unclear. In this study, we showed that pre- or post-surgical exposure to immobilization 6 h daily for three consecutive days did not change basal responses to mechanical, thermal, or cold stimuli or peak levels of incision-induced hypersensitivity to these stimuli; however, immobilization did prolong the duration of incision-induced hypersensitivity in both male and female rats. These phenomena were also observed in post-surgical exposure to forced swimming 25 min daily for 3 consecutive days. Short-term stress induced by immobilization was demonstrated by an elevation in the level of serum corticosterone, an increase in swim immobility, and a decrease in sucrose consumption. Blocking this short-term stress via intrathecal administration of a selective glucocorticoid receptor antagonist, RU38486, or bilateral adrenalectomy significantly attenuated the prolongation of incision-induced hypersensitivity to mechanical, thermal, and cold stimuli. Our results indicate that short-term stress during the pre- or post-operative period delays postoperative pain recovery although it does not affect basal pain perception. Prevention of short-term stress may facilitate patients' recovery from postoperative pain.

  16. Noise annoyance from stationary sources: Relationships with exposure metric day-evening-night level (DENL) and their confidence intervals

    NARCIS (Netherlands)

    Miedema, H.M.E.; Vos, H.

    2004-01-01

    Relationships between exposure to noise [metric: day-evening-night levels (DENL)] from stationary sources (shunting yards, a seasonal industry, and other industries) and annoyance are presented. Curves are presented for expected annoyance score, the percentage "highly annoyed" (%HA, cutoff at 72 on

  17. Identification of nuclear phosphoproteins as novel tobacco markers in mouse lung tissue following short-term exposure to tobacco smoke

    Directory of Open Access Journals (Sweden)

    Kanako Niimori-Kita

    2014-01-01

    Full Text Available Smoking is a risk factor for lung diseases, including chronic obstructive pulmonary disease and lung cancer. However, the molecular mechanisms mediating the progression of these diseases remain unclear. Therefore, we sought to identify signaling pathways activated by tobacco-smoke exposure, by analyzing nuclear phosphoprotein expression using phosphoproteomic analysis of lung tissue from mice exposed to tobacco smoke. Sixteen mice were exposed to tobacco smoke for 1 or 7 days, and the expression of phosphorylated peptides was analyzed by mass spectrometry. A total of 253 phosphoproteins were identified, including FACT complex subunit SPT16 in the 1-day exposure group, keratin type 1 cytoskeletal 18 (K18, and adipocyte fatty acid-binding protein, in the 7-day exposure group, and peroxiredoxin-1 (OSF3 and spectrin β chain brain 1 (SPTBN1, in both groups. Semi-quantitative analysis of the identified phosphoproteins revealed that 33 proteins were significantly differentially expressed between the control and exposed groups. The identified phosphoproteins were classified according to their biological functions. We found that the identified proteins were related to inflammation, regeneration, repair, proliferation, differentiation, morphogenesis, and response to stress and nicotine. In conclusion, we identified proteins, including OSF3 and SPTBN1, as candidate tobacco smoke-exposure markers; our results provide insights into the mechanisms of tobacco smoke-induced diseases.

  18. Distribution of silver in rats following 28 days of repeated oral exposure to silver nanoparticles or silver acetate

    DEFF Research Database (Denmark)

    Löschner, Katrin; Hadrup, Niels; Qvortrup, Klaus

    2011-01-01

    Background: The study investigated the distribution of silver after 28 days repeated oral administration of silver nanoparticles (AgNPs) and silver acetate (AgAc) to rats. Oral administration is a relevant route of exposure because of the use of silver nanoparticles in products related to food...... and food contact materials. Results: AgNPs were synthesized with a size distribution of 14 ± 4 nm in diameter (90% of the nanoparticle volume) and stabilized in aqueous suspension by the polymer polyvinylpyrrolidone (PVP). The AgNPs remained stable throughout the duration of the 28-day oral toxicity study...... in rats. The organ distribution pattern of silver following administration of AgNPs and AgAc was similar. However the absolute silver concentrations in tissues were lower following oral exposure to AgNPs. This was in agreement with an indication of a higher fecal excretion following administration of Ag...

  19. Pharmacokinetic and Genomic Effects of Arsenite in Drinking Water on Mouse Lung in a 30-Day Exposure

    Directory of Open Access Journals (Sweden)

    Jaya Chilakapati

    2015-06-01

    Full Text Available The 2 objectives of this subchronic study were to determine the arsenite drinking water exposure dependent increases in female C3H mouse liver and lung tissue arsenicals and to characterize the dose response (to 0, 0.05, 0.25, 1, 10, and 85 ppm arsenite in drinking water for 30 days and a purified AIN-93M diet for genomic mouse lung expression patterns. Mouse lungs were analyzed for inorganic arsenic, monomethylated, and dimethylated arsenicals by hydride generation atomic absorption spectroscopy. The total lung mean arsenical levels were 1.4, 22.5, 30.1, 50.9, 105.3, and 316.4 ng/g lung tissue after 0, 0.05, 0.25, 1, 10, and 85 ppm, respectively. At 85 ppm, the total mean lung arsenical levels increased 14-fold and 131-fold when compared to either the lowest noncontrol dose (0.05 ppm or the control dose, respectively. We found that arsenic exposure elicited minimal numbers of differentially expressed genes (DEGs; 77, 38, 90, 87, and 87 DEGs after 0.05, 0.25, 1, 10, and 85 ppm, respectively, which were associated with cardiovascular disease, development, differentiation, apoptosis, proliferation, and stress response. After 30 days of arsenite exposure, this study showed monotonic increases in mouse lung arsenical (total arsenic and dimethylarsinic acid concentrations but no clear dose-related increases in DEG numbers.

  20. Simulation of short-term fluctuations in gamma exposure rate due to radioactive cloud released from nuclear power plant

    International Nuclear Information System (INIS)

    Ichikawa, Yoichi; Shikata, Hiroshi; Ishida, Kenji; Ohba, Tachimori.

    1981-01-01

    The measured γ-exposure rate around nuclear power plants is due mainly to natural causes and radioactive clouds emitted from the plants. An exposure calculation method based on puff model has been already proposed to identify the plant contributions and to estimate values in response to short-term fluctuations of meteorological condition and the release rate. However, the calculation method by this model consumes a lot of computer time, since the calculation requires a three-dimensional integration of the distribution of the concentration from each puff. Hence, we propose a simplified method using approximate polynominal equations and interpolations. The computer time needed for the calculation with the simplified method is reduced to 1/30 of that required by the previous method. The calculation results by simplified method are compared with those by the previous method and with the measured exposure rate less natural background. The results of two different methods are in good agreement. The calculated exposure rate is within the range from half to twice as much as the measured exposure rate less background. (author)

  1. Assessment of the Real Life Exposure to 2G and 3G Base Stations Over a Day from Instantaneous Measurement

    OpenAIRE

    Mahfouz , Zaher; Gati , Azeddine; Lautru , David; Wiart , Joe; Hanna , Victor Fouad

    2011-01-01

    International audience; In this paper, the general public daily exposure to mobile telephony is investigated. The considered signals are GSM900, GSM1800, UMTS and HSDPA. The study focus on the assessment of the maximal real electric field received over the day from an instantaneous measurement performed any time during the day. An extrapolation factor is presented to extrapolate an instantaneous measurement for any signal to the maximal possible value received by this signal over the day. Thi...

  2. Assessing the short term impact of air pollution on mortality: a matching approach.

    Science.gov (United States)

    Baccini, Michela; Mattei, Alessandra; Mealli, Fabrizia; Bertazzi, Pier Alberto; Carugno, Michele

    2017-02-10

    The opportunity to assess short term impact of air pollution relies on the causal interpretation of the exposure-response association. However, up to now few studies explicitly faced this issue within a causal inference framework. In this paper, we reformulated the problem of assessing the short term impact of air pollution on health using the potential outcome approach to causal inference. We considered the impact of high daily levels of particulate matter ≤10 μm in diameter (PM 10 ) on mortality within two days from the exposure in the metropolitan area of Milan (Italy), during the period 2003-2006. Our research focus was the causal impact of a hypothetical intervention setting daily air pollution levels under a pre-fixed threshold. We applied a matching procedure based on propensity score to estimate the total number of attributable deaths (AD) during the study period. After defining the number of attributable deaths in terms of difference between potential outcomes, we used the estimated propensity score to match each high exposure day, namely each day with a level of exposure higher than 40 μg/m 3 , with a day with similar background characteristics but a level of exposure lower than 40 μg/m 3 . Then, we estimated the impact by comparing mortality between matched days. During the study period daily exposures larger than 40 μg/m 3 were responsible for 1079 deaths (90% CI: 116; 2042). The impact was more evident among the elderly than in the younger age classes. Exposures ≥ 40 μg/m 3 were responsible, among the elderly, for 1102 deaths (90% CI: 388, 1816), of which 797 from cardiovascular causes and 243 from respiratory causes. Clear evidence of an impact on respiratory mortality was found also in the age class 65-74, with 87 AD (90% CI: 11, 163). The propensity score matching turned out to be an appealing method to assess historical impacts in this field, which guarantees that the estimated total number of AD can be derived directly as sum

  3. Arsenic induced apoptosis in rat liver following repeated 60 days exposure

    International Nuclear Information System (INIS)

    Bashir, Somia; Sharma, Yukti; Irshad, M.; Nag, T.C.; Tiwari, Monica; Kabra, M.; Dogra, T.D.

    2006-01-01

    Background: Accumulation of the wide spread environmental toxin arsenic in liver results in hepatotoxcity. Exposure to arsenite and other arsenicals has been previously shown to induce apoptosis in certain tumor cell lines at low (1-3 μM) concentration. Aim: The present study was focused to elucidate the role of free radicals in arsenic toxicity and to investigate the nature of in vivo sodium arsenite induced cell death in liver. Methods: Male wistar rats were exposed to arsenite at three different doses of 0.05, 2.5 and 5 mg/l for 60 days. Oxidative stress in liver was measured by estimating pro-oxidant and antioxidant activity in liver. Histopathological examination of liver was carried out by light and transmission electron microscopy. Analysis of DNA fragmentation by gel electrophoresis was used to identify apoptosis after the exposure. Terminal deoxy-nucleotidyl transferase mediated dUTP Nick end-labeling (TUNEL) assay was used to qualify and quantify apoptosis. Results: A significant increase in cytochrome-P450 and lipid peroxidation accompanied with a significant alteration in the activity of many of the antioxidants was observed, all suggestive of arsenic induced oxidative stress. Histopathological examination under light and transmission electron microscope suggested a combination of ongoing necrosis and apoptosis. DNA-TUNEL showed an increase in apoptotic cells in liver. Agarose gel electrophoresis of DNA of hepatocytes resulted in a characteristic ladder pattern. Conclusion: Chronic arsenic administration induces a specific pattern of apoptosis called post-mitotic apoptosis

  4. Aqueous exposure to Aroclor 1254 modulates the mitogenic response of Atlantic salmon anterior kidney T-cells: indications of short- and long-term immunomodulation.

    Science.gov (United States)

    Iwanowicz, Luke R; Lerner, Darren T; Blazer, Vicki S; McCormick, Stephen D

    2005-05-15

    Polychlorinated biphenyls (PCBs) exist as persistent organic pollutants in numerous river systems in the United States. Unfortunately, some of these rivers are sites of active Atlantic salmon restoration programs, and polychlorinated biphenyls have been implicated as ancillary factors contributing to failed salmon restoration. Here, we investigate the immediate and chronic effects of intermediate duration aqueous PCB exposure (1 or 10 microgL-1 Aroclor 1254) on the mitogen-stimulated lymphoproliferative response of Atlantic salmon anterior kidney leukocytes (AKLs). A short-term study was designed to examine immunomodulation in Atlantic salmon smolts immediately following 21 days of aqueous exposure, while a long-term study evaluated chronic impacts in the mitogen response in parr 15 months post-exposure as larvae. The proliferative response of AKLs to the mitogens concanavalin A (CON A), phytohemaglutinnin-P (PHA-P), pokeweed mitogen (PWM), and lipopolysaccharide were used as an indice of immunomodulation. The proliferative response to the T-cell mitogens CON A and PHA-P was significantly increased in the 10 microgL-1 group (n=10; P=0.043 and 0.002, respectively) immediately following exposure of smolts. Additionally, The PHA-P response was significantly increased in the 1 microgL-1 exposure group (n=10, P=0.036). In fish treated as larvae and tested 15 months later, the PHA-P sensitive populations exhibited elevated proliferation in the 1 and 10 microgL-1 groups (n=12, P<0.04) relative to the vehicle control while the PWM response was significantly increased (n=12, P=0.036) only in the 10 microgL-1 treated groups. These results demonstrate an immunomodulatory effect of PCBs on T-cell mitogen sensitive populations of lymphocytes in Atlantic salmon as well as long-term immunomodulation in PHA-P and PWM sensitive populations.

  5. Ultraviolet and short wavelength visible light exposure: why ultraviolet protection alone is not adequate.

    Science.gov (United States)

    Reichow, Alan W; Citek, Karl; Edlich, Richard F

    2006-01-01

    The danger of exposure to ultraviolet (UV) radiation in both the natural environment and artificial occupational settings has long been recognized by national and international standards committees and worker safety agencies. There is an increasing body of literature that suggests that protection from UV exposure is not enough. Unprotected exposure to the short wavelengths of the visible spectrum, termed the "blue light hazard", is gaining acceptance as a true risk to long-term visual health. Global standards and experts in the field are now warning that those individuals who spend considerable time outdoors should seek sun filter eyewear with high impact resistant lenses that provide 100% UV filtration, high levels of blue light filtration, and full visual field lens/frame coverage as provided by high wrap eyewear. The Skin Cancer Foundation has endorsed certain sunglasses as "product[s]...effective [as] UV filter[s] for the eyes and surrounding skin". However, such endorsement does not necessarily mean that the eyewear meets all the protective needs for outdoor use. There are several brands that offer products with such protective characteristics. Performance sun eyewear by Nike Vision, available in both corrective and plano (nonprescription) forms, is one such brand incorporating these protective features.

  6. Associations between short-term exposure to nitrogen dioxide and mortality in 17 Chinese cities: the China Air Pollution and Health Effects Study (CAPES).

    Science.gov (United States)

    Chen, Renjie; Samoli, Evangelia; Wong, Chit-Ming; Huang, Wei; Wang, Zongshuang; Chen, Bingheng; Kan, Haidong

    2012-09-15

    Few multi-city studies in Asian developing countries have examined the acute health effects of ambient nitrogen dioxide (NO(2)). In the China Air Pollution and Health Effects Study (CAPES), we investigated the short-term association between NO(2) and mortality in 17 Chinese cities. We applied two-stage Bayesian hierarchical models to obtain city-specific and national average estimates for NO(2). In each city, we used Poisson regression models incorporating natural spline smoothing functions to adjust for long-term and seasonal trend of mortality, as well as other time-varying covariates. We examined the associations by age, gender and education status. We combined the individual-city estimates of the concentration-response curves to get an overall NO(2)-mortality association in China. The averaged daily concentrations of NO(2) in the 17 Chinese cities ranged from 26 μg/m(3) to 67 μg/m(3). In the combined analysis, a 10-μg/m(3) increase in two-day moving averaged NO(2) was associated with a 1.63% [95% posterior interval (PI), 1.09 to 2.17], 1.80% (95% PI, 1.00 to 2.59) and 2.52% (95% PI, 1.44 to 3.59) increase of total, cardiovascular, and respiratory mortality, respectively. These associations remained significant after adjustment for ambient particles or sulfur dioxide (SO(2)). Older people appeared to be more vulnerable to NO(2) exposure. The combined concentration-response curves indicated a linear association. Conclusively, this largest epidemiologic study of NO(2) in Asian developing countries to date suggests that short-term exposure to NO(2) is associated with increased mortality risk. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. An Inexpensive High-Temporal Resolution Electronic Sun Journal for Monitoring Personal Day to Day Sun Exposure Patterns

    Directory of Open Access Journals (Sweden)

    Nathan J. Downs

    2017-11-01

    Full Text Available Exposure to natural sunlight, specifically solar ultraviolet (UV radiation contributes to lifetime risks of skin cancer, eye disease, and diseases associated with vitamin D insufficiency. Improved knowledge of personal sun exposure patterns can inform public health policy; and help target high-risk population groups. Subsequently, an extensive number of studies have been conducted to measure personal solar UV exposure in a variety of settings. Many of these studies, however, use digital or paper-based journals (self-reported volunteer recall, or employ cost prohibitive electronic UV dosimeters (that limit the size of sample populations, to estimate periods of exposure. A cost effective personal electronic sun journal (ESJ built from readily available infrared photodiodes is presented in this research. The ESJ can be used to complement traditional UV dosimeters that measure total biologically effective exposure by providing a time-stamped sun exposure record. The ESJ can be easily attached to clothing and data logged to personal devices (including fitness monitors or smartphones. The ESJ improves upon self-reported exposure recording and is a cost effective high-temporal resolution option for monitoring personal sun exposure behavior in large population studies.

  8. A realistic in vitro exposure revealed seasonal differences in (pro-)inflammatory effects from ambient air in Fribourg, Switzerland.

    Science.gov (United States)

    Bisig, Christoph; Petri-Fink, Alke; Rothen-Rutishauser, Barbara

    2018-01-01

    Ambient air pollutant levels vary widely in space and time, therefore thorough local evaluation of possible effects is needed. In vitro approaches using lung cell cultures grown at the air-liquid interface and directly exposed to ambient air can offer a reliable addition to animal experimentations and epidemiological studies. To evaluate the adverse effects of ambient air in summer and winter a multi-cellular lung model (16HBE14o-, macrophages, and dendritic cells) was exposed in a mobile cell exposure system. Cells were exposed on up to three consecutive days each 12 h to ambient air from Fribourg, Switzerland, during summer and winter seasons. Higher particle number, particulate matter mass, and nitrogen oxide levels were observed in winter ambient air compared to summer. Good cell viability was seen in cells exposed to summer air and short-term winter air, but cells exposed three days to winter air were compromised. Exposure of summer ambient air revealed no significant upregulation of oxidative stress or pro-inflammatory genes. On the opposite, the winter ambient air exposure led to an increased oxidative stress after two exposure days, and an increase in three assessed pro-inflammatory genes already after 12 h of exposure. We found that even with a short exposure time of 12 h adverse effects in vitro were observed only during exposure to winter but not summer ambient air. With this work we have demonstrated that our simple, fast, and cost-effective approach can be used to assess (adverse) effects of ambient air.

  9. Short-Wavelength Light Enhances Cortisol Awakening Response in Sleep-Restricted Adolescents

    Directory of Open Access Journals (Sweden)

    Mariana G. Figueiro

    2012-01-01

    Full Text Available Levels of cortisol, a hormone produced by the adrenal gland, follow a daily, 24-hour rhythm with concentrations reaching a minimum in the evening and a peak near rising time. In addition, cortisol levels exhibit a sharp peak in concentration within the first hour after waking; this is known as the cortisol awakening response (CAR. The present study is a secondary analysis of a larger study investigating the impact of short-wavelength (λmax≈470 nm light on CAR in adolescents who were sleep restricted. The study ran over the course of three overnight sessions, at least one week apart. The experimental sessions differed in terms of the light exposure scenarios experienced during the evening prior to sleeping in the laboratory and during the morning after waking from a 4.5-hour sleep opportunity. Eighteen adolescents aged 12–17 years were exposed to dim light or to 40 lux (0.401 W/m2 of 470-nm peaking light for 80 minutes after awakening. Saliva samples were collected every 20 minutes to assess CAR. Exposure to short-wavelength light in the morning significantly enhanced CAR compared to dim light. Morning exposure to short-wavelength light may be a simple, yet practical way to better prepare adolescents for an active day.

  10. Evaluation of the deposition, translocation and pathological response of brake dust with and without added chrysotile in comparison to crocidolite asbestos following short-term inhalation: interim results.

    Science.gov (United States)

    Bernstein, David M; Rogers, Rick; Sepulveda, Rosalina; Kunzendorf, Peter; Bellmann, Bernd; Ernst, Heinrich; Phillips, James I

    2014-04-01

    Chrysotile has been frequently used in the past in manufacturing brakes and continues to be used in brakes in many countries. This study was designed to provide an understanding of the biokinetics and potential toxicology following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6 h/day for 5 days to either brake dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake dust or crocidolite asbestos. No significant pathological response was observed at any time point in either the brake dust or chrysotile/brake dust exposure groups. The long chrysotile fibers (>20 μm) cleared quickly with T(½) estimated as 30 and 33 days, respectively in the brake dust and the chrysotile/brake dust exposure groups. In contrast, the long crocidolite fibers had a T(½)>1000 days and initiated a rapid inflammatory response in the lung following exposure resulting in a 5-fold increase in fibrotic response within 91 days. These results provide support that brake dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung following short term inhalation. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Kinetics of granulocytic and erythroid progenitor cells are affected differently by short-term, low-level benzene exposure

    Energy Technology Data Exchange (ETDEWEB)

    Dempster, A.M.; Snyder, C.A. (New York Univ. Medical Center, NY (United States). Inst. of Environmental Medicine)

    1991-09-01

    Mice were exposed to either air or 10 ppm benzene for 6 h/d X 5 d. Immediately after the last exposure, mice were injected, i.v., with either saline or hydroxyurea (HU). The dose of HU was sufficient to kill hematopoietic cells in or near S-phase of the cell cycle and sufficient to synchronize the surviving populations of hematopoietic cells. Three days after benzene exposure, CFU-E numbers had declined to 50% of control values while CFU-GM numbers were equal to control values at this time. The benzene exposures were sufficient to double the percentage of CFU-E in S-phase but produced no such increase among CFU-Gm. During 3 days of recovery from benzene exposure and HU treatment, the CFU-E population expanded 30-fold while the CFU-GM population expanded less than 3-fold. Following benzene exposure and HU treatment, both progenitor cells produced elevated numbers of their respective progeny. When CFU-E from benzene-exposed mice were cultured with varying concentrations of erythropoietin (EPO), the response at maximal EPO concentration was 66% of the response by control CFU-E. This strongly suggests that the CFU-E populations from benzene-exposed mice had been depleted of cells in or near S-phase. The results indicate that CFU-GM respond to low-level benzene exposure by increasing their rate of differentiation but not their rate of proliferation, while CFU-E respond by increasing both their rates of differentiation and proliferation. We speculate that it is the increase in CFU-E proliferation that renders these cells more susceptible to benzene than their granulocytic counterparts, especially those CFU-E at or near the S-phase of the cell cycle. (orig.).

  12. Thyroid Disruption in Zebrafish Larvae by Short-Term Exposure to Bisphenol AF

    Directory of Open Access Journals (Sweden)

    Tianle Tang

    2015-10-01

    Full Text Available Bisphenol AF (BPAF is extensively used as a raw material in industry, resulting in its widespread distribution in the aqueous environment. However, the effect of BPAF on the hypothalamic-pituitary-thyroidal (HPT axis remains unknown. For elucidating the disruptive effects of BPAF on thyroid function and expression of the representative genes along the HPT axis in zebrafish (Danio rerio embryos, whole-body total 3,3′,5-triiodothyronine (TT3, total 3,5,3′,5′-tetraiodothyronine (TT4, free 3,3′,5-triiodothyronine (FT3 and free 3,5,3′,5′-tetraiodothyronine (FT4 levels were examined following 168 h post-fertilization exposure to different BPAF concentrations (0, 5, 50 and 500 μg/L. The results showed that whole-body TT3, TT4, FT3 and FT4 contents decreased significantly with the BPAF treatment, indicating an endocrine disruption of thyroid. The expression of thyroid-stimulating hormone-β and thyroglobulin genes increased after exposing to 50 μg/L BPAF in seven-day-old larvae. The expressions of thyronine deiodinases type 1, type 2 and transthyretin mRNAs were also significantly up-regulated, which were possibly associated with a deterioration of thyroid function. However, slc5a5 gene transcription was significantly down-regulated at 50 μg/L and 500 μg/L BPAF exposure. Furthermore, trα and trβ genes were down-regulated transcriptionally after BPAF exposure. It demonstrates that BPAF exposure triggered thyroid endocrine toxicity by altering the whole-body contents of thyroid hormones and changing the transcription of the genes involved in the HPT axis in zebrafish larvae.

  13. Short-term sleep disturbance-induced stress does not affect basal pain perception, but does delay postsurgical pain recovery

    OpenAIRE

    Wang, Po-Kai; Cao, Jing; Wang, Hongzhen; Liang, Lingli; Zhang, Jun; Lutz, Brianna Marie; Shieh, Kun-Ruey; Bekker, Alex; Tao, Yuan-Xiang

    2015-01-01

    Chronic sleep disturbance-induced stress is known to increase basal pain sensitivity. However, most surgical patients frequently report short-term sleep disturbance/deprivation during pre- and post-operation periods and have normal pain perception pre-surgery. Whether this short-term sleep disturbance affects postsurgical pain is elusive. We here reported that pre- or post-exposure to rapid eye movement sleep disturbance (REMSD) 6 h daily for 3 consecutive days did not alter basal responses t...

  14. Gene expression changes during short day induced terminal bud formation in Norway spruce.

    Science.gov (United States)

    Asante, Daniel K A; Yakovlev, Igor A; Fossdal, Carl Gunnar; Holefors, Anna; Opseth, Lars; Olsen, Jorunn E; Junttila, Olavi; Johnsen, Øystein

    2011-02-01

    The molecular basis for terminal bud formation in autumn is not well understood in conifers. By combining suppression subtractive hybridization and monitoring of gene expression by qRT-PCR analysis, we aimed to identify genes involved in photoperiodic control of growth cessation and bud set in Norway spruce. Close to 1400 ESTs were generated and their functional distribution differed between short day (SD-12 h photoperiod) and long day (LD-24 h photoperiod) libraries. Many genes with putative roles in protection against stress appeared differentially regulated under SD and LD, and also differed in transcript levels between 6 and 20 SDs. Of these, PaTFL1(TERMINAL FLOWER LIKE 1) showed strongly increased transcript levels at 6 SDs. PaCCCH(CCCH-TYPE ZINC FINGER) and PaCBF2&3(C-REPEAT BINDING FACTOR 2&3) showed a later response at 20 SDs, with increased and decreased transcript levels, respectively. For rhythmically expressed genes such as CBFs, such differences might represent a phase shift in peak expression, but might also suggest a putative role in response to SD. Multivariate analyses revealed strong differences in gene expression between LD, 6 SD and 20 SD. The robustness of the gene expression patterns was verified in 6 families differing in bud-set timing under natural light with gradually decreasing photoperiod. © 2010 Blackwell Publishing Ltd.

  15. The effect of short exposure to coloured light on thermal perception: a study using Virtual Reality

    OpenAIRE

    Chinazzo, Giorgia; Chamilothori, Kynthia; Wienold, Jan; Andersen, Marilyne

    2017-01-01

    This study investigates the effect of short exposure to coloured light on thermal perception. To give the impression of natural daylight passing through coloured filters, but avoiding the drawbacks of conducting an experiment with daylight, continuously changing due to daily and seasonal variations, and to weather conditions, we investigate the use of Virtual Reality as a means to control the visual conditions, creating a hybrid environment with thermal and visual stimuli from the real and vi...

  16. Alcohol Advertising Exposure Among Middle School-Age Youth: An Assessment Across All Media and Venues.

    Science.gov (United States)

    Collins, Rebecca L; Martino, Steven C; Kovalchik, Stephanie A; Becker, Kirsten M; Shadel, William G; D'Amico, Elizabeth J

    2016-05-01

    The purpose of this study was to quantify middle school youth's exposure to alcohol advertisements across media and venues, determine venues of greatest exposure, and identify characteristics of youth who are most exposed. Over a 10-month period in 2013, 589 Los Angeles-area youth ages 11-14 from diverse racial/ethnic backgrounds completed a short paper-and-pencil survey assessing background characteristics and then participated in a 14-day ecological momentary assessment, logging all exposures to alcohol advertisements on handheld computers as they occurred. African American and Hispanic youth were exposed to an average of 4.1 and 3.4 advertisements per day, respectively, nearly two times as many as non-Hispanic White youth, who were exposed to 2.0 advertisements per day. Girls were exposed to 30% more advertisements than boys. Most exposures were to outdoor advertisements, with television advertisements a close second. Exposure to alcohol advertising is frequent among middle school-age youth and may put them at risk for earlier or more frequent underage drinking. Greater restrictions on alcohol advertising outdoors and on television should be considered by regulators and by the alcohol industry and should focus particularly on reducing exposure among minority youth.

  17. Downregulation of immediate-early genes linking to suppression of neuronal plasticity in rats after 28-day exposure to glycidol

    Energy Technology Data Exchange (ETDEWEB)

    Akane, Hirotoshi [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan); Saito, Fumiyo [Chemicals Evaluation and Research Institute, Japan, 1-4-25 Koraku, Bunkyo-ku, Tokyo 112-0004 (Japan); Shiraki, Ayako [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan); Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193 (Japan); Takeyoshi, Masahiro; Imatanaka, Nobuya [Chemicals Evaluation and Research Institute, Japan, 1-4-25 Koraku, Bunkyo-ku, Tokyo 112-0004 (Japan); Itahashi, Megu [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan); Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193 (Japan); Murakami, Tomoaki [Laboratory of Veterinary Toxicology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan); Shibutani, Makoto, E-mail: mshibuta@cc.tuat.ac.jp [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan)

    2014-09-01

    We previously found that the 28-day oral toxicity study of glycidol at 200 mg/kg/day in rats resulted in axonopathy in both the central and peripheral nervous systems and aberrations in the late-stage of hippocampal neurogenesis targeting the process of neurite extension. To capture the neuronal parameters in response to glycidol toxicity, these animals were subjected to region-specific global gene expression profiling in four regions of cerebral and cerebellar architectures, followed by immunohistochemical analysis of selected gene products. Expression changes of genes related to axonogenesis and synaptic transmission were observed in the hippocampal dentate gyrus, cingulate cortex and cerebellar vermis at 200 mg/kg showing downregulation in most genes. In the corpus callosum, genes related to growth, survival and functions of glial cells fluctuated their expression. Immunohistochemically, neurons expressing gene products of immediate-early genes, i.e., Arc, Fos and Jun, decreased in their number in the dentate granule cell layer, cingulate cortex and cerebellar vermis. We also applied immunohistochemical analysis in rat offspring after developmental exposure to glycidol through maternal drinking water. The results revealed increases of Arc{sup +} neurons at 1000 ppm and Fos{sup +} neurons at ≥ 300 ppm in the dentate granule cell layer of offspring only at the adult stage. These results suggest that glycidol suppressed neuronal plasticity in the brain after 28-day exposure to young adult animals, in contrast to the operation of restoration mechanism to increase neuronal plasticity at the adult stage in response to aberrations in neurogenesis after developmental exposure. - Highlights: • Neuronal toxicity parameters after 28-day glycidol treatment were examined in rats. • Region-specific global gene expression profiling was conducted in brain regions. • Cortical tissues downregulated genes on axonogenesis and synaptic transmission. • Cortical tissues

  18. Oxidative stress in duckweed (Lemna minor L.) caused by short-term cadmium exposure

    Energy Technology Data Exchange (ETDEWEB)

    Razinger, Jaka [Department for Environmental Technologies and Biomonitoring, Institute of Physical Biology, Veliko Mlacevo 59, SI-1290 Grosuplje (Slovenia)], E-mail: jaka@ifb.si; Dermastia, Marina [National Institute of Biology, Vecna pot 111, p.p. 141, SI-1001 Ljubljana (Slovenia); Biotechnical Faculty, Department of Biology, University of Ljubljana, Vecna pot 111, SI-1000 Ljubljana (Slovenia); Koce, Jasna Dolenc [Biotechnical Faculty, Department of Biology, University of Ljubljana, Vecna pot 111, SI-1000 Ljubljana (Slovenia); Zrimec, Alexis [Department for Environmental Technologies and Biomonitoring, Institute of Physical Biology, Veliko Mlacevo 59, SI-1290 Grosuplje (Slovenia)

    2008-06-15

    The mechanisms of plant defence against cadmium toxicity have been studied by short-term exposure of Lemna minor L. (common duckweed) to concentrations of CdCl{sub 2} ranging from 0 to 500 {mu}M. High accumulation of cadmium was observed (12,320 {+-} 2155 {mu}g g{sup -1} at 500 {mu}M CdCl{sub 2}), which caused a gradual decrease of plant growth, increased lipid peroxidation, and weakened the entire antioxidative defence. Total glutathione concentration decreased significantly; however, the concentration of oxidized glutathione remained stable. The responses of four antioxidant enzymes showed that catalase was the most inhibited after CdCl{sub 2} exposure, ascorbate peroxidase and guaiacol peroxidase moderately, and glutathione reductase least. The total antioxidative potential revealed an induced antioxidative network at 0.1 {mu}M CdCl{sub 2} (137 {+-} 13.2% of the control) and its reduction to only 47.4 {+-} 4.0% of the control at higher cadmium concentrations. The possible application of the examined biomarkers in ecotoxicological research is discussed. - The increase of total antioxidative potential at low cadmium concentration is one of the mechanisms that helps duckweed to cope with cadmium-induced oxidative stress.

  19. Oxidative stress in duckweed (Lemna minor L.) caused by short-term cadmium exposure

    International Nuclear Information System (INIS)

    Razinger, Jaka; Dermastia, Marina; Koce, Jasna Dolenc; Zrimec, Alexis

    2008-01-01

    The mechanisms of plant defence against cadmium toxicity have been studied by short-term exposure of Lemna minor L. (common duckweed) to concentrations of CdCl 2 ranging from 0 to 500 μM. High accumulation of cadmium was observed (12,320 ± 2155 μg g -1 at 500 μM CdCl 2 ), which caused a gradual decrease of plant growth, increased lipid peroxidation, and weakened the entire antioxidative defence. Total glutathione concentration decreased significantly; however, the concentration of oxidized glutathione remained stable. The responses of four antioxidant enzymes showed that catalase was the most inhibited after CdCl 2 exposure, ascorbate peroxidase and guaiacol peroxidase moderately, and glutathione reductase least. The total antioxidative potential revealed an induced antioxidative network at 0.1 μM CdCl 2 (137 ± 13.2% of the control) and its reduction to only 47.4 ± 4.0% of the control at higher cadmium concentrations. The possible application of the examined biomarkers in ecotoxicological research is discussed. - The increase of total antioxidative potential at low cadmium concentration is one of the mechanisms that helps duckweed to cope with cadmium-induced oxidative stress

  20. Short, frequent, 5-days-per-week, in-center hemodialysis versus 3-days-per week treatment: a randomized crossover pilot trial through the Midwest Pediatric Nephrology Consortium.

    Science.gov (United States)

    Laskin, Benjamin L; Huang, Guixia; King, Eileen; Geary, Denis F; Licht, Christoph; Metlay, Joshua P; Furth, Susan L; Kimball, Tom; Mitsnefes, Mark

    2017-08-01

    No controlled trials in children with end-stage kidney disease have assessed the benefits of more frequently administered hemodialysis (HD). We conducted a multicenter, crossover pilot trial to determine if short, more frequent (5 days per week) in-center HD was feasible and associated with improvements in blood pressure compared with three conventional HD treatments per week. Because adult studies have not controlled for the weekly duration of dialysis, we fixed the total treatment time at 12 h a week of dialysis during two 3-month study periods; only frequency varied from 5 to 3 days per week between study periods. Eight children (median age 16.7 years) consented at three children's hospitals. The prespecified primary composite outcome was a sustained 10% decrease in systolic blood pressure and/or a decrease in antihypertensive medications relative to each study period's baseline. Among the six patients completing both study periods, five (83.3%) experienced the primary outcome during HD performed 5 days per week but not 3 days per week; one of the six (16.7%) achieved that outcome during 3-day but not 5-day (p = 0.22) per week HD. During 5-day HD, all patients had significantly more treatments during which their pre-HD systolic (p = 0.01) or diastolic (p = 0.01) blood pressure was 10% lower than baseline. We observed that more frequent HD sessions per week was feasible and associated with improved blood pressure control, but barriers to changing thrice-weekly standard of care include financial reimbursement and the time demands associated with more frequent treatments.

  1. Association between Vancomycin Day 1 Exposure Profile and Outcomes among Patients with Methicillin-Resistant Staphylococcus aureus Infective Endocarditis

    Science.gov (United States)

    Casapao, Anthony M.; Lodise, Thomas P.; Davis, Susan L.; Claeys, Kimberly C.; Kullar, Ravina; Levine, Donald P.

    2015-01-01

    Given the critical importance of early appropriate therapy, a retrospective cohort (2002 to 2013) was performed at the Detroit Medical Center to evaluate the association between the day 1 vancomycin exposure profile and outcomes among patients with MRSA infective endocarditis (IE). The day 1 vancomycin area under the concentration-time curve (AUC0–24) and the minimum concentration at 24 h (Cmin 24) was estimated for each patient using the Bayesian procedure in ADAPT 5, an approach shown to accurately predict the vancomycin exposure with low bias and high precision with limited pharmacokinetic sampling. Initial MRSA isolates were collected and vancomycin MIC was determined by broth microdilution (BMD) and Etest. The primary outcome was failure, defined as persistent bacteremia (≥7 days) or 30-day attributable mortality. Classification and regression tree analysis (CART) was used to determine the vancomycin exposure variables associated with an increased probability of failure. In total, 139 patients met study criteria; 76.3% had right-sided IE, 16.5% had left-sided IE, and 7.2% had both left and right-sided IE. A total of 89/139 (64%) experienced failure by composite definition. In the CART analysis, failure was more pronounced in patients with an AUC0–24/MIC as determined by BMD of ≤600 relative to those with AUC0–24/MIC as determined by BMD of >600 (69.8% versus 54.7%, respectively, P = 0.073). In the logistic regression analysis, an AUC/MIC as determined by BMD of ≤600 (adjusted odds ratio, 2.3; 95% confidence interval, 1.01 to 5.37; P = 0.047) was independently associated with failure. Given the retrospective nature of the present study, further prospective studies are required but these data suggest that patients with an AUC0–24/MIC as determined by BMD of ≤600 present an increased risk of failure. PMID:25753631

  2. Dose-rate effects of ethylene oxide exposure on developmental toxicity.

    Science.gov (United States)

    Weller, E; Long, N; Smith, A; Williams, P; Ravi, S; Gill, J; Henessey, R; Skornik, W; Brain, J; Kimmel, C; Kimmel, G; Holmes, L; Ryan, L

    1999-08-01

    In risk assessment, evaluating a health effect at a duration of exposure that is untested involves assuming that equivalent multiples of concentration (C) and duration (T) of exposure have the same effect. The limitations of this approach (attributed to F. Haber, Zur Geschichte des Gaskrieges [On the history of gas warfare], in Funf Vortrage aus den Jahren 1920-1923 [Five lectures from the years 1920-1923], 1924, Springer, Berlin, pp. 76-92), have been noted in several studies. The study presented in this paper was designed to specifically look at dose-rate (C x T) effects, and it forms an ideal case study to implement statistical models and to examine the statistical issues in risk assessment. Pregnant female C57BL/6J mice were exposed, on gestational day 7, to ethylene oxide (EtO) via inhalation for 1.5, 3, or 6 h at exposures that result in C x T multiples of 2100 or 2700 ppm-h. EtO was selected because of its short half-life, documented developmental toxicity, and relevance to exposures that occur in occupational settings. Concurrent experiments were run with animals exposed to air for similar periods. Statistical analysis using models developed to assess dose-rate effects revealed significant effects with respect to fetal death and resorptions, malformations, crown-to-rump length, and fetal weight. Animals exposed to short, high exposures of EtO on day 7 of gestation were found to have more adverse effects than animals exposed to the same C x T multiple but at longer, lower exposures. The implication for risk assessment is that applying Haber's Law could potentially lead to an underestimation of risk at a shorter duration of exposure and an overestimation of risk at a longer duration of exposure. Further research, toxicological and statistical, are required to understand the mechanism of the dose-rate effects, and how to incorporate the mechanistic information into the risk assessment decision process.

  3. Human biomonitoring after chemical incidents and during short-term maintenance work as a tool for exposure analysis and assessment.

    Science.gov (United States)

    Bader, M; Van Weyenbergh, T; Verwerft, E; Van Pul, J; Lang, S; Oberlinner, C

    2014-12-15

    Human biomonitoring (HBM) is frequently used for the analysis and assessment of exposure to chemicals under routine working conditions. In recent years, HBM has also been applied to monitor the exposure of the general population, and of emergency responders in the aftermath of chemical incidents. Two examples of targeted HBM programs in the chemical industry are described and discussed in this paper: (1) analysis and assessment of the exposure of firefighters and chemical workers after the spill of p-chloroaniline from a burning chemical barrel, and (2) biomonitoring of maintenance workers potentially exposed to benzene during regular turnarounds. The results of these investigations underline that human biomonitoring contributes substantially to comprehensive exposure analyses, human health risk assessments and communication. In addition, regular HBM surveillance and feedback can assist in the continuous improvement of workplace safety measures and exposure control. In conclusion, data on accidental or short-term exposure to hazardous chemicals are an important source of information for the further development of limit and assessment values, the validation of biomarkers and of targeted HBM programs for both routine monitoring and disaster management. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Stability of the human sperm DNA methylome to folic acid fortification and short-term supplementation.

    Science.gov (United States)

    Chan, D; McGraw, S; Klein, K; Wallock, L M; Konermann, C; Plass, C; Chan, P; Robaire, B; Jacob, R A; Greenwood, C M T; Trasler, J M

    2017-02-01

    Do short-term and long-term exposures to low-dose folic acid supplementation alter DNA methylation in sperm? No alterations in sperm DNA methylation patterns were found following the administration of low-dose folic acid supplements of 400 μg/day for 90 days (short-term exposure) or when pre-fortification of food with folic acid and post-fortification sperm samples (long-term exposure) were compared. Excess dietary folate may be detrimental to health and DNA methylation profiles due to folate's role in one-carbon metabolism and the formation of S-adenosyl methionine, the universal methyl donor. DNA methylation patterns are established in developing male germ cells and have been suggested to be affected by high-dose (5 mg/day) folic acid supplementation. This is a control versus treatment study where genome-wide sperm DNA methylation patterns were examined prior to fortification of food (1996-1997) in men with no history of infertility at baseline and following 90-day exposure to placebo (n = 9) or supplement containing 400 μg folic acid/day (n = 10). Additionally, pre-fortification sperm DNA methylation profiles (n = 19) were compared with those of a group of post-fortification (post-2004) men (n = 8) who had been exposed for several years to dietary folic acid fortification. Blood and seminal plasma folate levels were measured in participants before and following the 90-day treatment with placebo or supplement. Sperm DNA methylation was assessed using the whole-genome and genome-wide techniques, MassArray epityper, restriction landmark genomic scanning, methyl-CpG immunoprecipitation and Illumina HumanMethylation450 Bead Array. Following treatment, supplemented individuals had significantly higher levels of blood and seminal plasma folates compared to placebo. Initial first-generation genome-wide analyses of sperm DNA methylation showed little evidence of changes when comparing pre- and post-treatment samples. With Illumina HumanMethylation450 BeadChip arrays

  5. Prevalence and impact of short sleep duration in redeployed OIF soldiers.

    Science.gov (United States)

    Luxton, David D; Greenburg, David; Ryan, Jenny; Niven, Alexander; Wheeler, Gary; Mysliwiec, Vincent

    2011-09-01

    Short sleep duration (SSD) is common among deployed soldiers. The prevalence of SSD during redeployment, however, is unknown. Cross-sectional study of a brigade combat team (n = 3152 US Army soldiers) surveyed 90-180 days after completing a 6-15 month deployment to Iraq as part of Operation Iraqi Freedom (OIF). Survey items targeted sleep habits and comorbid medical conditions. Multivariate logistic regression analyses were performed to calculate adjusted odds ratios of medical comorbidities associated with SSD. US Army Infantry Post. All soldiers from a redeploying brigade combat team participated in a health assessment between 90 and 180 days upon return to Ft. Lewis from Iraq. None. A total of 2738 (86.9%) soldiers answered questions regarding self-perceived sleep and were included in the analysis. Mean sleep duration was 5.8 ± 1.2 hours. Nineteen hundred fifty-nine (72%) slept ≤ 6 h, but only 16% reported a daytime nap or felt their job performance was affected due to lack of sleep. Short sleep was more common among soldiers who reported combat exposure. After controlling for combat exposure, short sleep duration (SSD) was associated with symptoms of depression, posttraumatic stress disorder, panic syndrome, and with high-risk health behaviors such as abuse of tobacco and alcohol products, and suicide attempts. SSD is common among redeployed soldiers. Soldiers who experienced combat are at increased risk for persistent SSD and comorbidities associated with SSD. Efforts to reestablish good sleep habits and aggressive evaluation of soldiers with persistent SSD following deployment may aid in the prevention and management of associated medical conditions.

  6. Mechanisms of Orthostatic Tolerance Improvement Following Artificial Gravity Exposure Differ Between Men and Women

    Science.gov (United States)

    Evans, J. M.; Stenger, M. B.; Ferguson, C. R.; Ribiero, L. C.; Zhang, Q.; Moore, F. B.; Serrador, J.; Smith, J. D.; Knapp, C. F.

    2014-01-01

    We recently determined that a short exposure to artificial gravity (AG) improved the orthostatic tolerance limit (OTL) of cardiovascularly deconditioned subjects. We now seek to determine the mechanisms of that improvement in these hypovolemic men and women. Methods. We determined the orthostatic tolerance limit (OTL) of 9 men and 8 women following a 90 min exposure to AG compared to 90 min of head down bed rest (HDBR). In both cases (21 days apart), subjects were made hypovolemic (low salt diet plus 20 mg intravenous furosemide). Orthostatic tolerance was determined from a combination of head up tilt and increasing lower body negative pressure until presyncope. Mean values and correlations with OTL were determined for heart rate, blood pressure, stroke volume, cardiac output and peripheral resistance (Finometer), cerebral artery blood velocity (DWL), partial pressure of carbon dioxide (Novametrics) and body segmental impedance (UFI THRIM) were measured during supine baseline, during OTL to presyncope and during supine recovery Results. Orthostatic tolerance of these hypovolemic subjects was significantly greater on the day of AG exposure than on the HDBR day. Regression of OTL on these variables identified significant relationships on the HDBR day that were not evident on the AG day: resting TPR correlated positively while resting cerebral flow correlated negatively with OTL. On both days, women's resting stroke volume correlated positively with orthostatic tolerance. Higher group mean values of stroke volume and cerebral artery flow and lower values of blood pressure, peripheral vascular and cerebrovascular resistance both at control and during OTL testing were observed on the AG day. Even though regression of OTL on resting stroke volume was significant only in women, presyncopal stroke volume reached the same level on each day of study for both men and women while the OTL test lasted 30% longer in men and 22% longer in women. Cerebral artery flow appeared to

  7. Short-term exposure to oleandrin enhances responses to IL-8 by increasing cell surface IL-8 receptors

    Science.gov (United States)

    Raviprakash, Nune; Manna, Sunil Kumar

    2014-01-01

    BACKGROUND AND PURPOSE One of the first steps in host defence is the migration of leukocytes. IL-8 and its receptors are a chemokine system essential to such migration. Up-regulation of these receptors would be a viable strategy to treat dysfunctional host defence. Here, we studied the effects of the plant glycoside oleandrin on responses to IL-8 in a human monocytic cell line. EXPERIMENTAL APPROACH U937 cells were incubated with oleandrin (1-200 ng mL−1) for either 1 h (pulse) or for 24 h (non-pulse). Apoptosis; activation of NF-κB, AP-1 and NFAT; calcineurin activity and IL-8 receptors (CXCR1 and CXCR2) were measured using Western blotting, RT-PCR and reporter gene assays. KEY RESULTS Pulse exposure to oleandrin did not induce apoptosis or cytoxicity as observed after non-pulse exposure. Pulse exposure enhanced activation of NF-κB induced by IL-8 but not that induced by TNF-α, IL-1, EGF or LPS. Exposure to other apoptosis-inducing compounds (azadirachtin, resveratrol, thiadiazolidine, or benzofuran) did not enhance activation of NF-κB. Pulse exposure to oleandrin increased expression of IL-8 receptors and chemotaxis, release of enzymes and activation of NF-κB, NFAT and AP-1 along with increased IL-8-mediated calcineurin activation, and wound healing. Pulse exposure increased numbers of cell surface IL-8 receptors. CONCLUSIONS AND IMPLICATIONS Short-term (1 h; pulse) exposure to a toxic glycoside oleandrin, enhanced biological responses to IL-8 in monocytic cells, without cytoxicity. Pulse exposure to oleandrin could provide a viable therapy for those conditions where leukocyte migration is defective. PMID:24172227

  8. Short-term effects of salt exposure on the maize chloroplast protein pattern.

    Science.gov (United States)

    Zörb, Christian; Herbst, Ramona; Forreiter, Christoph; Schubert, Sven

    2009-09-01

    It is of fundamental importance to understand the physiological differences leading to salt resistance and to get access to the molecular mechanisms underlying this physiological response. The aim of this work was to investigate the effects of short-term salt exposure on the proteome of maize chloroplasts in the initial phase of salt stress (up to 4 h). It could be shown that sodium ions accumulate quickly and excessively in chloroplasts in the initial phase of moderate salt stress. A change in the chloroplast protein pattern was observed without a change in water potential of the leaves. 2-DE revealed that 12 salt-responsive chloroplast proteins increased while eight chloroplast proteins decreased. Some of the maize chloroplast proteins such as CF1e and a Ca(2+)-sensing receptor show a rather transient response for the first 4 h of salt exposure. The enhanced abundance of the ferredoxin NADPH reductase, the 23 kDa polypeptide of the photosystem II, and the FtsH-like protein might reflect mechanism to attenuate the detrimental effects of Na(+) on the photosynthetic machinery. The observed transient increase and subsequent decrease of selected proteins may exhibit a counterbalancing effect of target proteins in this context. Intriguingly, several subunits of the CF1-CF0 complex are unequally affected, whereas others do not respond at all.

  9. Sauna exposure immediately prior to short-term heat acclimation accelerates phenotypic adaptation in females.

    Science.gov (United States)

    Mee, Jessica A; Peters, Sophie; Doust, Jonathan H; Maxwell, Neil S

    2018-02-01

    Investigate whether a sauna exposure prior to short-term heat acclimation (HA) accelerates phenotypic adaptation in females. Randomised, repeated measures, cross-over trial. Nine females performed two 5-d HA interventions (controlled hyperthermia T re ≥38.5°C), separated by 7-wk, during the follicular phase of the menstrual cycle confirmed by plasma concentrations of 17-β estradiol and progesterone. Prior to each 90-min HA session participants sat for 20-min in either a temperate environment (20°C, 40% RH; HA temp ) wearing shorts and sports bra or a hot environment (50°C, 30% RH) wearing a sauna suit to replicate sauna conditions (HA sauna ). Participants performed a running heat tolerance test (RHTT) 24-h pre and 24-h post HA. Mean heart rate (HR) (85±4 vs. 68±5 bpm, p≤0.001), sweat rate (0.4±0.2 vs. 0.0±0.0Lh -1 , p≤0.001), and thermal sensation (6±0 vs. 5±1, p=0.050) were higher during the sauna compared to temperate exposure. Resting rectal temperature (T re ) (-0.28±0.16°C), peak T re (-0.42±0.22°C), resting HR (-10±4 bpm), peak HR (-12±7 bpm), T re at sweating onset (-0.29±0.17°C) (p≤0.001), thermal sensation (-0.5±0.5; p=0.002), and perceived exertion (-3±2; p≤0.001) reduced during the RHTT, following HA sauna ; but not HA temp . Plasma volume expansion was greater following HA sauna (HA sauna , 9±7%; HA temp , 1±5%; p=0.013). Sweat rate (p≤0.001) increased and sweat NaCl (p=0.006) reduced during the RHTT following HA sauna and HA temp . This novel strategy initiated HA with an attenuation of thermoregulatory, cardiovascular, and perceptual strain in females due to a measurably greater strain in the sauna compared to temperate exposure when adopted prior to STHA. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  10. Influence of short-term aluminum exposure on demineralized bone matrix induced bone formation

    Energy Technology Data Exchange (ETDEWEB)

    Severson, A.R. (Minnesota Univ., Duluth, MN (United States). Dept. of Anatomy and Cell Biology); Haut, C.F.; Firling, C.E. (Minnesota Univ., Duluth, MN (United States). Dept. of Biology); Huntley, T.E. (Minnesota Univ., Duluth, MN (United States). Dept. of Biochemistry and Molecular Biology)

    1992-12-01

    The effects of aluminum exposure on bone formation employing the demineralized bone matrix (DBM) induced bone development model were studied using 4-week-old Sprague-Dawley rats injected with a saline (control) or an aluminum chloride (experimental) solution. After 2 weeks of aluminum treatment, 20-mg portions of rat DBM were implanted subcutaneously on each side in the thoracic region of the control and experimental rats. Animals were killed 7, 12, or 21 days after implantation of the DBM and the developing plaques removed. No morphological, histochemical, or biochemical differences were apparent between plaques from day 7 control and experimental rats. Plaques from day 12 control and experimental rats exhibited cartilage formation and alkaline phosphatase activity localized in osteochondrogenic cells, chondrocytes, osteoblasts, and extracellular matrix. Unlike the plaques from control rats that contained many osteoblastic mineralizing fronts, the plaques from the 12-day experimental group had a preponderance of cartilaginous tissue, no evidence of mineralization, increased levels of alkaline phosphatase activity, and a reduced calcium content. Plaques developing for 21 days in control animals demonstrated extensive new bone formation and bone marrow development, while those in the experimental rats demonstrated unmineralized osteoid-like matrix with poorly developed bone marrow. Alkaline phosphatase activity of the plaques continued to remain high on day 21 for the control and experimental groups. Calcium levels were significantly reduced in the experimental group. These biochemical changes correlated with histochemical reductions in bone calcification. Thus, aluminum administration to rats appears to alter the differentiation and calcification of developing cartilage and bone in the DBM-induced bone formation model and suggests that aluminum by some mechanism alters the matrix calcification in growing bones. (orig.).

  11. Facilitation or disengagement? Attention bias in facial affect processing after short-term violent video game exposure.

    Directory of Open Access Journals (Sweden)

    Yanling Liu

    Full Text Available Previous research has been inconsistent on whether violent video games exert positive and/or negative effects on cognition. In particular, attentional bias in facial affect processing after violent video game exposure continues to be controversial. The aim of the present study was to investigate attentional bias in facial recognition after short term exposure to violent video games and to characterize the neural correlates of this effect. In order to accomplish this, participants were exposed to either neutral or violent video games for 25 min and then event-related potentials (ERPs were recorded during two emotional search tasks. The first search task assessed attentional facilitation, in which participants were required to identify an emotional face from a crowd of neutral faces. In contrast, the second task measured disengagement, in which participants were required to identify a neutral face from a crowd of emotional faces. Our results found a significant presence of the ERP component, N2pc, during the facilitation task; however, no differences were observed between the two video game groups. This finding does not support a link between attentional facilitation and violent video game exposure. Comparatively, during the disengagement task, N2pc responses were not observed when participants viewed happy faces following violent video game exposure; however, a weak N2pc response was observed after neutral video game exposure. These results provided only inconsistent support for the disengagement hypothesis, suggesting that participants found it difficult to separate a neutral face from a crowd of emotional faces.

  12. Facilitation or disengagement? Attention bias in facial affect processing after short-term violent video game exposure.

    Science.gov (United States)

    Liu, Yanling; Lan, Haiying; Teng, Zhaojun; Guo, Cheng; Yao, Dezhong

    2017-01-01

    Previous research has been inconsistent on whether violent video games exert positive and/or negative effects on cognition. In particular, attentional bias in facial affect processing after violent video game exposure continues to be controversial. The aim of the present study was to investigate attentional bias in facial recognition after short term exposure to violent video games and to characterize the neural correlates of this effect. In order to accomplish this, participants were exposed to either neutral or violent video games for 25 min and then event-related potentials (ERPs) were recorded during two emotional search tasks. The first search task assessed attentional facilitation, in which participants were required to identify an emotional face from a crowd of neutral faces. In contrast, the second task measured disengagement, in which participants were required to identify a neutral face from a crowd of emotional faces. Our results found a significant presence of the ERP component, N2pc, during the facilitation task; however, no differences were observed between the two video game groups. This finding does not support a link between attentional facilitation and violent video game exposure. Comparatively, during the disengagement task, N2pc responses were not observed when participants viewed happy faces following violent video game exposure; however, a weak N2pc response was observed after neutral video game exposure. These results provided only inconsistent support for the disengagement hypothesis, suggesting that participants found it difficult to separate a neutral face from a crowd of emotional faces.

  13. Facilitation or disengagement? Attention bias in facial affect processing after short-term violent video game exposure

    Science.gov (United States)

    Liu, Yanling; Lan, Haiying; Teng, Zhaojun; Guo, Cheng; Yao, Dezhong

    2017-01-01

    Previous research has been inconsistent on whether violent video games exert positive and/or negative effects on cognition. In particular, attentional bias in facial affect processing after violent video game exposure continues to be controversial. The aim of the present study was to investigate attentional bias in facial recognition after short term exposure to violent video games and to characterize the neural correlates of this effect. In order to accomplish this, participants were exposed to either neutral or violent video games for 25 min and then event-related potentials (ERPs) were recorded during two emotional search tasks. The first search task assessed attentional facilitation, in which participants were required to identify an emotional face from a crowd of neutral faces. In contrast, the second task measured disengagement, in which participants were required to identify a neutral face from a crowd of emotional faces. Our results found a significant presence of the ERP component, N2pc, during the facilitation task; however, no differences were observed between the two video game groups. This finding does not support a link between attentional facilitation and violent video game exposure. Comparatively, during the disengagement task, N2pc responses were not observed when participants viewed happy faces following violent video game exposure; however, a weak N2pc response was observed after neutral video game exposure. These results provided only inconsistent support for the disengagement hypothesis, suggesting that participants found it difficult to separate a neutral face from a crowd of emotional faces. PMID:28249033

  14. Alcohol Advertising Exposure Among Middle School–Age Youth: An Assessment Across All Media and Venues

    Science.gov (United States)

    Collins, Rebecca L.; Martino, Steven C.; Kovalchik, Stephanie A.; Becker, Kirsten M.; Shadel, William G.; D’Amico, Elizabeth J.

    2016-01-01

    Objective: The purpose of this study was to quantify middle school youth’s exposure to alcohol advertisements across media and venues, determine venues of greatest exposure, and identify characteristics of youth who are most exposed. Method: Over a 10-month period in 2013, 589 Los Angeles–area youth ages 11–14 from diverse racial/ethnic backgrounds completed a short paper-and-pencil survey assessing background characteristics and then participated in a 14-day ecological momentary assessment, logging all exposures to alcohol advertisements on handheld computers as they occurred. Results: African American and Hispanic youth were exposed to an average of 4.1 and 3.4 advertisements per day, respectively, nearly two times as many as non-Hispanic White youth, who were exposed to 2.0 advertisements per day. Girls were exposed to 30% more advertisements than boys. Most exposures were to outdoor advertisements, with television advertisements a close second. Conclusions: Exposure to alcohol advertising is frequent among middle school–age youth and may put them at risk for earlier or more frequent underage drinking. Greater restrictions on alcohol advertising outdoors and on television should be considered by regulators and by the alcohol industry and should focus particularly on reducing exposure among minority youth. PMID:27172570

  15. Coral Bleaching Susceptibility Is Decreased following Short-Term (1–3 Year Prior Temperature Exposure and Evolutionary History

    Directory of Open Access Journals (Sweden)

    Joshua A. Haslun

    2011-01-01

    Full Text Available Coral exposed to short periods of temperature stress (≥1.0°C above mean monthly maximum and/or increased frequencies of high temperatures may bolster resilience to global warming associated with climate change. We compared Montastraea cavernosa (Linnaeus, 1767; Cnidaria, Scleractinia, Faviidae from the Florida Keys National Marine Sanctuary (FKNMS and the Flower Garden Banks National Marine Sanctuary (FGBNMS. Thermal stress has been reported frequently within the FKNMS; however, corals in the FGBNMS experience nominal exposures to similar stressors. Corals were exposed to three temperatures (27°C, 31°C, and 35°C for 72 h. Colonies from the FKNMS lost significantly fewer viable and necrotic zooxanthellae under conditions of acute stress (35°C than the FGBNMS colonies. This indicates that the FKNMS corals are less temperature-sensitive than those in the FGBNMS. The observed differences point to greater prior temperature exposure and adaptation in the former versus the latter site when correlated to previous years of thermal exposure.

  16. Effects of short term and long term Extremely Low Frequency Magnetic Field on depressive disorder in mice: Involvement of nitric oxide pathway.

    Science.gov (United States)

    Madjid Ansari, Alireza; Farzampour, Shahrokh; Sadr, Ali; Shekarchi, Babak; Majidzadeh-A, Keivan

    2016-02-01

    Previous reports on the possible effects of Extremely Low Frequency Magnetic Fields (ELF MF) on mood have been paradoxical in different settings while no study has yet been conducted on animal behavior. In addition, it was shown that ELF MF exposure makes an increase in brain nitric oxide level. Therefore, in the current study, we aimed to assess the possible effect(s) of ELF MF exposure on mice Forced Swimming Test (FST) and evaluate the probable role of the increased level of nitric oxide in the observed behavior. Male adult mice NMRI were recruited to investigate the short term and long term ELF MF exposure (0.5 mT and 50 Hz, single 2h and 2 weeks 2h a day). Locomotor behavior was assessed by using open-field test (OFT) followed by FST to evaluate the immobility time. Accordingly, NΩ-nitro-l-arginine methyl ester 30 mg/kg was used to exert anti-depressant like effect. According to the results, short term exposure did not alter the immobility time, whereas long term exposure significantly reduces immobility time (pmice, whereas short term exposure has no significant effect. Also, reversing the anti-depressant activity of L-NAME indicates a probable increase in the brain nitric oxide. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Influence of a combination of two tetrachlorobiphenyl congeners (PCB 47; PCB 77) on thyroid status, choline acetyltransferase (ChAT) activity, and short- and long-term memory in 30-day-old Sprague-Dawley rats

    International Nuclear Information System (INIS)

    Donahue, Douglas A.; Dougherty, Edward J.; Meserve, Lee A.

    2004-01-01

    The important role of thyroid hormones in growth and development, maintenance of body temperature, digestion, cardiac function, and normal brain development can be disrupted by environmental contaminants like polychlorinated biphenyls (PCB). Polychlorinated biphenyls are environmental contaminants that are widespread, persistent, lipophilic, and bioaccumulate through food webs, concentrating in adipose tissue. Placental and lactational PCB exposure of offspring causes metabolic and endocrine disruptions including hypothyroxinemia, spatial learning and memory deficits, neurochemical and neurobehavioral alterations, and reproductive problems. Previous studies in our lab using the individual congeners PCB 47 (2,2',4,4'-tetrachlorobiphenyl, ortho-substituted) and PCB 77 (3,3',4,4'-tetrachlorobiphenyl, non-ortho-substituted) have demonstrated alterations in thyroid hormone levels, alterations in brain choline acetyltransferase (ChAT) activity, and spatial learning deficits. In the present study, pregnant Sprague-Dawley rats were fed a diet with or without a mixture of PCB 47/77 at 1.25 ppm, 12.5 ppm or 25.0 ppm (w/w). Rat pups were swum in the Morris water maze four times a day on days 21-29 in order for the animals to learn the position of a submerged fixed platform. A probe test was run on day 24 (30 min after last swim) for short-term memory, and on day 29 (24 h after the last swim) for long-term memory after removal of the platform. Time spent in the quadrant previously containing the platform was recorded. Rats were decapitated on day 30, serum collected and frozen at -20 deg. ChAT activity was measured radiometrically in basal forebrain and hippocampus. All PCB-treated animals experienced a depression in both triiodothyronine (T 3 ) and thyroxine (T 4 ). The present study found that all doses of PCB depressed ChAT activity in hippocampus with no significant alteration in the basal forebrain. In PCB-treated animals, short-term memory showed a trend toward

  18. Persistence of Livestock-Associated Methicillin-Resistant Staphylococcus aureus in Field Workers after Short-Term Occupational Exposure to Pigs and Veal Calves

    NARCIS (Netherlands)

    van Cleef, B.A.G.L.; Graveland, H.; Haenen, A.P.J.; van de Giessen, A.W.; Heederik, D.; Wagenaar, J.A.; Kluytmans, J.A.J.W.

    2011-01-01

    The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carriage in pig and veal calf farmers in the Netherlands is estimated at 25 to 35%. However, no information is available about MRSA carriage in humans after short-term occupational exposure to pigs or veal calves. This study

  19. Resistance and recovery of river biofilms receiving short pulses of Triclosan and Diuron.

    Science.gov (United States)

    Proia, L; Morin, S; Peipoch, M; Romaní, A M; Sabater, S

    2011-08-01

    The effects of the herbicide Diuron (DIU) and the bactericide Triclosan (TCS) were assessed on laboratory-grown stream biofilms. Four week-old biofilms were exposed in mesocosms to 48-hours of short pulses of either DIU or TCS. The direct and indirect effects of each toxicant on the biofilms, and the subsequent recovery of the biofilms, were evaluated according to structural and functional biomarkers. These parameters were analyzed immediately before exposure, immediately after exposure, and 9 and 16days post-exposure. DIU caused an increase in diatom mortality (+79%), which persisted until the end of the experiment. TCS also affected diatom mortality (+41%), although the effect did not appear until 1week post-exposure. TCS caused an increase in bacterial mortality (+45%); however, this parameter returned to normal values 1week post-exposure. TCS compromised the cellular integrity of the green alga Spirogyra sp., whereas DIU did not. TCS also strongly inhibited phosphate uptake (-71%), which did not return to normal values until 2weeks post-exposure. DIU directly affected algae, but barely affected the heterotrophs, whereas TCS seriously impaired bacteria (direct effect) as well as autotrophs (indirect effect). However, the biofilms recovered their normal structure and function within only a few days to a few weeks. These findings demonstrate the capacity of biofilms to cope with periodic inputs of toxicants, but also the risks associated to repeated exposure or multi-contamination in aquatic ecosystems. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Short- and Long-Term Effects of Prenatal Exposure to Iron Oxide Nanoparticles: Influence of Surface Charge and Dose on Developmental and Reproductive Toxicity

    Directory of Open Access Journals (Sweden)

    Kristin R. Di Bona

    2015-12-01

    Full Text Available Iron oxide nanoparticles (NPs are commonly utilized for biomedical, industrial, and commercial applications due to their unique properties and potential biocompatibility. However, little is known about how exposure to iron oxide NPs may affect susceptible populations such as pregnant women and developing fetuses. To examine the influence of NP surface-charge and dose on the developmental toxicity of iron oxide NPs, Crl:CD1(ICR (CD-1 mice were exposed to a single, low (10 mg/kg or high (100 mg/kg dose of positively-charged polyethyleneimine-Fe2O3-NPs (PEI-NPs, or negatively-charged poly(acrylic acid-Fe2O3-NPs (PAA-NPs during critical windows of organogenesis (gestation day (GD 8, 9, or 10. A low dose of NPs, regardless of charge, did not induce toxicity. However, a high exposure led to charge-dependent fetal loss as well as morphological alterations of the uteri (both charges and testes (positive only of surviving offspring. Positively-charged PEI-NPs given later in organogenesis resulted in a combination of short-term fetal loss (42% and long-term alterations in reproduction, including increased fetal loss for second generation matings (mice exposed in utero. Alternatively, negatively-charged PAA-NPs induced fetal loss (22% earlier in organogenesis to a lesser degree than PEI-NPs with only mild alterations in offspring uterine histology observed in the long-term.

  1. Changes in cold tolerance due to a 14-day stay in the Canadian Arctic

    Science.gov (United States)

    Livingstone, S. D.; Romet, T.; Keefe, A. A.; Nolan, R. W.

    1996-12-01

    Responses to cold exposure tests both locally and of the whole body were examined in subjects who stayed in the Arctic (average maximum and minimum temperatures -11 and -21° C respectively) for 14 days of skiing and sleeping in tents. These changes were compared to responses in subjects living working in Ottawa, Canada (average max. and min. temperatures -5 and -11° C respectively). The tests were done before the stay in the Arctic (Pre), immediately after the return (Post 1) and approximately 32 days after the return (Post 2). For the whole-body cold exposure each subject, wearing only shorts and lying on a rope mesh cot, was exposed to an ambient temperature of 10° C. There was no consistent response in the changes of metabolic or body temperature to this exposure in either of groups and, in addition, the changes over time were variable. Cold induced vasodilatation (CIVD) was determined by measuring temperature changes in the middle finger of the nondominant hand upon immersion in ice water for 30 min. CIVD was depressed after the Arctic exposure whilst during the Post 2 testing, although variable, did not return to the Pre values; the responses of the control group were similar. These results indicate that normal seasonal changes may be as important in adaptation as a stay in the Arctic. Caution is advised in the separation of seasonal effects when examining the changes in adaptation after exposure to a cold environment.

  2. Glucose Homeostasis During Short-term and Prolonged Exposure to High Altitudes

    Science.gov (United States)

    Ader, Marilyn; Bergman, Richard N.

    2015-01-01

    Most of the literature related to high altitude medicine is devoted to the short-term effects of high-altitude exposure on human physiology. However, long-term effects of living at high altitudes may be more important in relation to human disease because more than 400 million people worldwide reside above 1500 m. Interestingly, individuals living at higher altitudes have a lower fasting glycemia and better glucose tolerance compared with those who live near sea level. There is also emerging evidence of the lower prevalence of both obesity and diabetes at higher altitudes. The mechanisms underlying improved glucose control at higher altitudes remain unclear. In this review, we present the most current evidence about glucose homeostasis in residents living above 1500 m and discuss possible mechanisms that could explain the lower fasting glycemia and lower prevalence of obesity and diabetes in this population. Understanding the mechanisms that regulate and maintain the lower fasting glycemia in individuals who live at higher altitudes could lead to new therapeutics for impaired glucose homeostasis. PMID:25675133

  3. Preliminary Analyses Showed Short-Term Mental Health Improvements after a Single-Day Manager Training.

    Science.gov (United States)

    Boysen, Elena; Schiller, Birgitta; Mörtl, Kathrin; Gündel, Harald; Hölzer, Michael

    2018-01-10

    Psychosocial working conditions attract more and more attention when it comes to mental health in the workplace. Trying to support managers to deal with their own as well as their employees' psychological risk factors, we conducted a specific manager training. Within this investigation, we wanted to learn about the training's effects and acceptance. A single-day manager training was provided in a large industrial company in Germany. The participants were asked to fill out questionnaires regarding their own physical and mental health condition as well as their working situation. Questionnaires were distributed at baseline, 3-month, and 12-month follow-up. At this point of time the investigation is still ongoing. The current article focuses on short-term preliminary effects. Analyses only included participants that already completed baseline and three months follow-up. Preliminary results from three-month follow-up survey ( n = 33, nmale = 30, Mage = 47.5) indicated positive changes in the manager's mental health condition measured by the Patient Health Questionnaire for depression (PHQ-9: Mt1 = 3.82, Mt2 = 3.15). Training managers about common mental disorders and risk factors at the workplace within a single-day workshop seems to promote positive effects on their own mental health. Especially working with the managers on their own early stress symptoms might have been an important element.

  4. Cellular changes in the hamster testicular interstitium with ageing and after exposure to short photoperiod.

    Science.gov (United States)

    Beltrán-Frutos, E; Seco-Rovira, V; Ferrer, C; Madrid, J F; Sáez, F J; Canteras, M; Pastor, L M

    2016-04-01

    The aim of this study was to evaluate the cellular changes that occur in the hamster testicular interstitium in two very different physiological situations involving testicular involution: ageing and exposure to a short photoperiod. The animals were divided into an 'age group' with three subgroups - young, adult and old animals - and a 'regressed group' with animals subjected to a short photoperiod. The testicular interstitium was characterised by light and electron microscopy. Interstitial cells were studied histochemically with regard to their proliferation, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP in situ nick end labelling (TUNEL+) and testosterone synthetic activity. We identified two types of Leydig cell: Type A cells showed a normal morphology, while Type B cells appeared necrotic. With ageing, pericyte proliferation decreased but there was no variation in the index of TUNEL-positive Leydig cells. In the regressed group, pericyte proliferation was greater and TUNEL-positive cells were not observed in the interstitium. The testicular interstitium suffered few ultrastructural changes during ageing and necrotic Leydig cells were observed. In contrast, an ultrastructural involution of Leydig cells with no necrosis was observed in the regressed group. In conclusion, the testicular interstitium of Mesocricetus auratus showed different cellular changes in the two groups (age and regressed), probably due to the irreversible nature of ageing and the reversible character of changes induced by short photoperiod.

  5. Effect of irradiation and exposure to nitrogen on the mortality of adults. Tribolium confusum J. du V

    International Nuclear Information System (INIS)

    Buscarlet, L.A.; Aminian, B.; Bali, C.

    1986-09-01

    For insect control irradiation can be improved by combination with other methods in order to limit the dose and hence to preserve the sensory qualities of some foods like fresh fruits, or to kill more rapidly the adult stage for avoiding the risk that a shipment be rejected because of the presence of living insects. The effect of irradiation with long exposure to inert gaz has not been reported yet. This study presents preliminary results on Tribolium confusum. Irradiation alone from 120 to 1000 Gy killed 100% of adults T. confusum in 12 to 15 days. At 60 Gy 10% insects were living after 28 days and at 40 Gy no mortality was observed. Mortality of adults T. confusum observed 10 days after exposure to nitrogen increased with the exposure time. 100 % mortality was reached for 17 hours exposure. When insects were exposed to nitrogen before or after irradiation synergic effects were observed. The greatest efficiency was obtained when insects were irradiated at 600 Gy after 9 hr exposure. When insects were exposed to nitrogen during irradiation the protective effectt of a short exposure (1/2 hr) was observed only for low doses (< 60 Gy). For a long exposure (9 hr) early irradiation at 600 Gy was more efficient than late irradiation

  6. Effect of short-term exposure to two hydrophilic-coated and one gel pre-lubricated urinary catheters on sperm vitality, motility and kinematics in vitro.

    Science.gov (United States)

    Auger, J; Rihaoui, R; François, N; Eustache, F

    2007-06-01

    This study aimed to determine the in vitro effect of a short-term exposure to two hydrophilic-coated and one gel pre-lubricated urinary catheters on human sperm quality. Semen samples of various qualities were coincubated with each catheter for 5 min at 37 degrees C. The percentages of live and motile sperm with their kinematic characteristics were blindly assessed in control and treated samples at the end of the coincubation and 10 and 55 min later. The three catheters had no effect on sperm vitality. Similarly, the lubricated catheter and one hydrophilic-coated catheter negligibly modulated sperm motility. In contrast, the other hydrophilic-coated catheter tested had a significant negative effect on sperm movement. Further studies are warranted, the issue being especially relevant to the collection of spermatozoa in spinal cord diseased patients catheterizing themselves several times a day. In this population, compounds releasing from the catheter and accumulating in the urethra could be an additional factor contributing to the poor sperm quality.

  7. Short exposure to acetylene to distinguish between nitrifier and denitrifier nitrous oxide production in soil and sediment samples

    OpenAIRE

    Kester, R.A.; Boer, W. de; Laanbroek, H.J.

    1996-01-01

    The contribution of nitrifiers and denitrifiers to the nitrous oxide production in slurries of calcareous silt loam and river bank sediment at different oxygen concentrations was determined using acetylene as nitrification inhibitor. The addition of 10 Pa acetylene resulted in inhibition of nitrous oxide production at oxic conditions, but strongly enhanced the nitrous oxide production at oxygen-poor and anoxic conditions. Inhibition of nitrification by short exposure (1 to 24 h) to high conce...

  8. Short-term effects of ambient air pollution on pediatric outpatient visits for respiratory diseases in Yichang city, China.

    Science.gov (United States)

    Liu, Yuewei; Xie, Shuguang; Yu, Qing; Huo, Xixiang; Ming, Xiaoyan; Wang, Jing; Zhou, Yun; Peng, Zhe; Zhang, Hai; Cui, Xiuqing; Xiang, Hua; Huang, Xiji; Zhou, Ting; Chen, Weihong; Shi, Tingming

    2017-08-01

    Previous studies have suggested that short-term exposure to ambient air pollution was associated with pediatric hospital admissions and emergency room visits for certain respiratory diseases; however, there is limited evidence on the association between short-term air pollution exposure and pediatric outpatient visits. Our aim was to quantitatively assess the short-term effects of ambient air pollution on pediatric outpatient visits for respiratory diseases. We conducted a time-series study in Yichang city, China between Jan 1, 2014 and Dec 31, 2015. Daily counts of pediatric respiratory outpatient visits were collected from 3 large hospitals, and then linked with air pollution data from 5 air quality monitoring stations by date. We used generalized additive Poisson models to conduct linear and nonlinear exposure-response analyses between air pollutant exposures and pediatric respiratory outpatient visits, adjusting for seasonality, day of week, public holiday, temperature, and relative humidity. Each interquartile range (IQR) increase in PM 2.5 (lag 0), PM 10 (lag 0), NO 2 (lag 0), CO (lag 0), and O 3 (lag 4) concentrations was significantly associated with a 1.91% (95% CI: 0.60%, 3.23%), 2.46% (1.09%, 3.85%), 1.88% (0.49%, 3.29%), 2.00% (0.43%, 3.59%), and 1.91% (0.45%, 3.39%) increase of pediatric respiratory outpatient visits, respectively. Similarly, the nonlinear exposure-response analyses showed monotonic increases of pediatric respiratory outpatient visits by increasing air pollutant exposures, though the associations for NO 2 and CO attenuated at higher concentrations. These associations were unlikely modified by season. We did not observe significant association for SO 2 exposure. Our results suggest that short-term exposures to PM 2.5 , PM 10 , NO 2 , CO, and O 3 may account for increased risk of pediatric outpatient visits for respiratory diseases, and emphasize the needs for reduction of air pollutant exposures for children. Copyright © 2017

  9. Does Occupational Exposure of Shahid Dastghieb International Airport Workers to Radiofrequency Radiation Affect Their Short Term Memory and Reaction Time?

    Directory of Open Access Journals (Sweden)

    Jarideh S.

    2015-05-01

    Full Text Available Background: Airport workers are continuously exposed to different levels of radiofrequency microwave (RF/MW radiation emitted by radar equipments. Radars are extensively used in military and aviation industries. Over the past several years, our lab has focused on the health effects of exposure to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons and MRI. The main goal of this study was to investigate if occupational exposure of Shahid Dastghieb international airport workers to radiofrequency radiation affects their short term memory and reaction time. Methods: Thirty two airport workers involved in duties at control and approach tower (21 males and 11 females, with the age range of 27-67 years old (mean age of 37.38, participated voluntary in this study. On the other hand, 29 workers (13 males, and 16 females whose offices were in the city with no exposure history to radar systems were also participated in this study as the control group. The employees’ reaction time and short term memory were analyzed using a standard visual reaction time (VRT test software and the modified Wechsler memory scale test, respectively. Results: The mean± SD values for the reaction times of the airport employees (N=32 and the control group (N=29 were 0.45±0.12 sec and 0.46±0.17 sec, respectively. Moreover, in the four subset tests; i.e. paired words, forward digit span, backward digit span and word recognition, the following points were obtained for the airport employees and the control group, respectively: (i pair words test: 28.00±13.13 and 32.07±11.65, (ii forward digit span: 8.38±1.40 and 9.03±1.32, (iii backward digit span: 5.54±1.87 and 6.31±1.46, and (iv word recognition: 5.73±2.36 and 6.50±1.93. These differences were not statistically significant. Conclusion: The occupational exposure of the employees to the RF radiation in Shahid

  10. Effects of external environments on the short beam shear strength of filament wound graphite/epoxy

    Science.gov (United States)

    Penn, B. G.; Clemons, J. M.

    1986-01-01

    Filament wound graphite/epoxy samples were immersed in seawater, deionized water, and toluene at room temperature and 80 deg C for 5, 15, and 43 days, and in methanol at room temperature for 15 and 43 days. The percent weight gains and short beam shear strengths were determined after environmental exposure. Samples immersed in deionized water and seawater had higher percent weight gains than those immersed in toluene at room temperature and 80 deg C. The percent weight gains for samples immersed in methanol at room temperature were comparable to those of deionized water and seawater immersed samples. A comparison of percent decreases in short beam shear strengths could not be made due to a large scatter in data. This may indicate defects in samples due to machining or variations in material properties due to processing.

  11. Short term exposure to cooking fumes and pulmonary function

    OpenAIRE

    Qvenild Torgunn; Svendsen Kristin; Svedahl Sindre; Sjaastad Ann; Hilt Bjørn

    2009-01-01

    Abstract Background Exposure to cooking fumes may have different deleterious effects on the respiratory system. The aim of this study was to look at possible effects from inhalation of cooking fumes on pulmonary function. Methods Two groups of 12 healthy volunteers (A and B) stayed in a model kitchen for two and four hours respectively, and were monitored with spirometry four times during twenty four hours, on one occasion without any exposure, and on another with exposure to controlled level...

  12. Long- and Short-Term Exposure To Air Pollution and Inflammatory/Hemostatic Markers in Midlife Women

    Science.gov (United States)

    Green, Rochelle; Broadwin, Rachel; Malig, Brian; Basu, Rupa; Gold, Ellen B.; Qi, Lihong; Sternfeld, Barbara; Bromberger, Joyce T.; Greendale, Gail A.; Kravitz, Howard M.; Tomey, Kristin; Matthews, Karen; Derby, Carol; Jackson, Elizabeth A.; Green, Robin; Ostro, Bart

    2016-01-01

    Background Studies have reported associations between long-term air pollution exposures and cardiovascular mortality. The biological mechanisms connecting them remain uncertain. Methods We examined associations of fine particles (PM2.5) and ozone with serum markers of cardiovascular disease risk in a cohort of midlife women. We obtained information from women enrolled at six sites in the multi-ethnic, longitudinal Study of Women's Health Across the Nation, including repeated measurements of high-sensitivity C-reactive protein (hs-CRP), fibrinogen, tissue-type plasminogen activator antigen (tPA-ag), plasminogen activator inhibitor Type 1 (PAI-1), and Factor VIIc (Factor VII coagulant activity). We obtained residence-proximate PM2.5 and ozone monitoring data for a maximum five annual visits, calculating prior year, six-month, one-month, and one-day exposures and their relations to serum markers using longitudinal mixed models. Results For the 2,086 women studied from 1999 through 2004, PM2.5 exposures were associated with all blood markers except Factor VIIc after adjusting for age, race/ethnicity, education, site, body mass index, smoking, and recent alcohol use. Adjusted associations were of the strongest for prior year exposures for hs-CRP (21% increase per 10 μg/m3 PM2.5, 95% CI: 6.6, 37), tPA-ag (8.6%, 95% CI: 1.8, 16), and PAI-1 (35%, 95% CI: 19, 53). An association was also observed between year prior ozone exposure and Factor VIIc (5.7% increase per 10 ppb ozone, 95% CI: 2.9, 8.5). Conclusions Our findings suggest that prior year exposures to PM2.5 and ozone are associated with adverse effects on inflammatory and hemostatic pathways for cardiovascular outcomes in midlife women. PMID:26600256

  13. An assessment of the acute dietary exposure to glyphosate using deterministic and probabilistic methods.

    Science.gov (United States)

    Stephenson, C L; Harris, C A; Clarke, R

    2018-02-01

    Use of glyphosate in crop production can lead to residues of the active substance and related metabolites in food. Glyphosate has never been considered acutely toxic; however, in 2015 the European Food Safety Authority (EFSA) proposed an acute reference dose (ARfD). This differs from the Joint FAO/WHO Meeting on Pesticide Residues (JMPR) who in 2016, in line with their existing position, concluded that an ARfD was not necessary for glyphosate. This paper makes a comprehensive assessment of short-term dietary exposure to glyphosate from potentially treated crops grown in the EU and imported third-country food sources. European Union and global deterministic models were used to make estimates of short-term dietary exposure (generally defined as up to 24 h). Estimates were refined using food-processing information, residues monitoring data, national dietary exposure models, and basic probabilistic approaches to estimating dietary exposure. Calculated exposures levels were compared to the ARfD, considered to be the amount of a substance that can be consumed in a single meal, or 24-h period, without appreciable health risk. Acute dietary intakes were Probabilistic exposure estimates showed that the acute intake on no person-days exceeded 10% of the ARfD, even for the pessimistic scenario.

  14. Short-term exposure to the organotin compound triphenyltin modulates esterified steroid levels in females of Marisa cornuarietis.

    Science.gov (United States)

    Lyssimachou, Angeliki; Bachmann, J; Porte, C

    2008-08-29

    Long-term exposures to organotin compounds have shown alterations on endogenous steroid levels in gastropods together with the development of imposex. However, information regarding short-term effects of these compounds on the endocrine system of gastropods is lacking. This work aimed at investigating those responses in the ramshorn snail Marisa cornuarietis by looking at both endogenous levels of free and esterified steroids and the metabolism of the androgen precursor androstenedione by digestive gland/gonad microsomal fractions. One-week exposure to the organotin compound triphenyltin (TPT) led to a significant increase in esterified testosterone (60-85%) and a decrease in esterified estradiol (50-84%) in females, but had no effect on males. The observed alterations in esterified steroids were not directly related to changes in P450 aromatase activity that remained unchanged in exposed females. The enzymes involved in the metabolism of the androgen precursor androstenedione, namely 17beta-hydroxysteroid dehydrogenases and 5alpha-reductases, were not significantly altered by TPT exposure, suggesting that such enzymes are not primary targets of TPT in M. cornuarietis. Additional studies are needed to fully understand the significance of the observed alterations in females and their potential relationship with the development of imposex.

  15. Short Hospitalization system: a new way of interpreting day surgery care.

    Science.gov (United States)

    Rago, Rocco; Franceschini, Francesca; Tomassini, Carlo R

    2016-01-01

    Today's poorer income on the one hand and the more and more unbearable costs on the other, call for solutions to maintain public health through proper and collective care. We need to think of a new dimension of health, to found a modern and innovative approach, which can combine the respect of healthcare rights with the optimization of resources. Worldwide, franchises serving millions of people every year succeed in limiting operating costs and still offer a service and a quality equal to single businesses. Let's imagine every single Day Surgery Unit (DSU), within its own hospital, as a single trade: starting a process of centralized management and subsequent affiliation with other DSUs, they would increase their healthcare offer by means of solid organization, efficiency and foresight that with a strong focus on innovation and continuous updating, thus increasing its range of consumers and containing management costs. The Short Hospitalization System (SHS) is the proposed project, which is not only a type of hospitalization which is different from the ordinary, but also an innovative clinical-organizational model, with an important economic impact, where the management and maximization of the different hospital flows (care, professional, logistical, information), as well as the ability to implement strategies to anticipate them are crucial. The expected benefits are both clinically and socially relevant. Among them: 1) best practice build up; 2) lower impact on daily habits and increased patient satisfaction; 3) reduction of social and health expenditure.

  16. Short- and long-term cognitive effects of chronic cannabinoids administration in late-adolescence rats.

    Directory of Open Access Journals (Sweden)

    Hila Abush

    Full Text Available The use of cannabis can impair cognitive function, especially short-term memory. A controversial question is whether long-term cannabis use during the late-adolescence period can cause irreversible deficits in higher brain function that persist after drug use stops. In order to examine the short- and long-term effects of chronic exposure to cannabinoids, rats were administered chronic i.p. treatment with the CB1/CB2 receptor agonist WIN55,212-2 (WIN; 1.2 mg/kg for two weeks during the late adolescence period (post-natal days 45-60 and tested for behavioral and electrophysiological measures of cognitive performance 24 hrs, 10 and 30 days after the last drug injection. The impairing effects of chronic WIN on short-term memory in the water maze and the object recognition tasks as well as long-term potentiation (LTP in the ventral subiculum (vSub-nucleus accumbens (NAc pathway were temporary as they lasted only 24 h or 10 d after withdrawal. However, chronic WIN significantly impaired hippocampal dependent short-term memory measured in the object location task 24 hrs, 10, 30, and 75 days after the last drug injection. Our findings suggest that some forms of hippocampal-dependent short-term memory are sensitive to chronic cannabinoid administration but other cognitive impairments are temporary and probably result from a residue of cannabinoids in the brain or acute withdrawal effects from cannabinoids. Understanding the effects of cannabinoids on cognitive function may provide us with tools to overcome these impairments and for cannabinoids to be more favorably considered for clinical use.

  17. Short-term Lost Productivity per Victim: Intimate Partner Violence, Sexual Violence, or Stalking.

    Science.gov (United States)

    Peterson, Cora; Liu, Yang; Kresnow, Marcie-Jo; Florence, Curtis; Merrick, Melissa T; DeGue, Sarah; Lokey, Colby N

    2018-05-15

    The purpose of this study is to estimate victims' lifetime short-term lost productivity because of intimate partner violence, sexual violence, or stalking. U.S. nationally representative data from the 2012 National Intimate Partner and Sexual Violence Survey were used to estimate a regression-adjusted average per victim (female and male) and total population number of cumulative short-term lost work and school days (or lost productivity) because of victimizations over victims' lifetimes. Victims' lost productivity was valued using a U.S. daily production estimate. Analysis was conducted in 2017. Non-institutionalized adults with some lifetime exposure to intimate partner violence, sexual violence, or stalking (n=6,718 respondents; survey-weighted n=130,795,789) reported nearly 741 million lost productive days because of victimizations by an average of 2.5 perpetrators per victim. The adjusted per victim average was 4.9 (95% CI=3.9, 5.9) days, controlling for victim, perpetrator, and violence type factors. The estimated societal cost of this short-term lost productivity was $730 per victim, or $110 billion across the lifetimes of all victims (2016 USD). Factors associated with victims having a higher number of lost days included a higher number of perpetrators and being female, as well as sexual violence, physical violence, or stalking victimization by an intimate partner perpetrator, stalking victimization by an acquaintance perpetrator, and sexual violence or stalking victimization by a family member perpetrator. Short-term lost productivity represents a minimum economic valuation of the immediate negative effects of intimate partner violence, sexual violence, and stalking. Victims' lost productivity affects family members, colleagues, and employers. Published by Elsevier Inc.

  18. SHORT COMMUNICATIONS World Food Day: 16 October 2008

    African Journals Online (AJOL)

    2008-10-16

    Oct 16, 2008 ... World Food Day highlights the human right of each person to food and ... equip farmers with skills in vegetable production, farm business management and the marketing of farm produce. These skills are envisioned to enable ...

  19. Pulmonary effects of ultrafine and fine ammonium salts aerosols in healthy and monocrotaline-treated rats following short-term exposure

    NARCIS (Netherlands)

    Cassee, F.R.; Arts, J.H.E.; Fokkens, P.H.B.; Spoor, S.M.; Boere, A.J.F.; Bree, L. van; Dormans, J.A.M.A.

    2002-01-01

    In the present study the effects of a 3-day inhalation exposure to model compounds for ambient particulate matter were investigated: ammonium bisulfate, ammonium ferrosulfate, and ammonium nitrate, all components of the secondary aerosol fraction of ambient particulate matter (PM), and carbon black

  20. Suppression and recovery of the alveolar macrophage phagocytic system during continuous exposure to 0. 5 ppm ozone

    Energy Technology Data Exchange (ETDEWEB)

    Gilmour, M.I.; Hmieleski, R.R.; Stafford, E.A.; Jakab, G.J. (Johns Hopkins University, School of Hygiene and Public Health, Baltimore, MD (USA))

    1991-05-01

    Short-term exposures to ozone (O3) are known to impair pulmonary antibacterial defenses and alveolar macrophage (AM) phagocytosis in a dose-related manner. To determine the effect of prolonged O3 exposure, Swiss mice were exposed continuously to 0.5 ppm O3. At 1, 3, 7, and 14 days, intrapulmonary killing was assessed by inhalation challenge with Staphylococcus aureus or Proteus mirabilis and by comparing the number of viable bacteria remaining in the lungs at 4 h between O3-exposed and control animals. To evaluate the effects of O3 on the functional capacity of the AMs, Fc-receptor mediated phagocytosis was assessed. Ozone exposure impaired the intrapulmonary killing of S. aureus at 1 and 3 days; however, with prolonged exposure, the bactericidal capacity of the lungs returned to normal. This trend of an initial suppression followed by recovery was reflected in the phagocytic capacity of the AMs. In contrast to S. aureus, when P. mirabilis was used as the challenge organism, O3 exposure had no suppressive effect on pulmonary bactericidal activity, which correlated with an increase in the phagocytic cell population in the lungs. Morphologic examination of the lavaged macrophages showed that after 1 day of O3 exposure, the AMs were more foamy, and contained significantly more vacuoles. There was also a significant increase in binucleated cells at 3 days. These studies demonstrate that continuous exposure to O3 modulates AM-dependent lung defenses and points to the importance of the challenge organism and exposure protocol in establishing the adverse effect of O3.

  1. Modelling survival: exposure pattern, species sensitivity and uncertainty.

    Science.gov (United States)

    Ashauer, Roman; Albert, Carlo; Augustine, Starrlight; Cedergreen, Nina; Charles, Sandrine; Ducrot, Virginie; Focks, Andreas; Gabsi, Faten; Gergs, André; Goussen, Benoit; Jager, Tjalling; Kramer, Nynke I; Nyman, Anna-Maija; Poulsen, Veronique; Reichenberger, Stefan; Schäfer, Ralf B; Van den Brink, Paul J; Veltman, Karin; Vogel, Sören; Zimmer, Elke I; Preuss, Thomas G

    2016-07-06

    The General Unified Threshold model for Survival (GUTS) integrates previously published toxicokinetic-toxicodynamic models and estimates survival with explicitly defined assumptions. Importantly, GUTS accounts for time-variable exposure to the stressor. We performed three studies to test the ability of GUTS to predict survival of aquatic organisms across different pesticide exposure patterns, time scales and species. Firstly, using synthetic data, we identified experimental data requirements which allow for the estimation of all parameters of the GUTS proper model. Secondly, we assessed how well GUTS, calibrated with short-term survival data of Gammarus pulex exposed to four pesticides, can forecast effects of longer-term pulsed exposures. Thirdly, we tested the ability of GUTS to estimate 14-day median effect concentrations of malathion for a range of species and use these estimates to build species sensitivity distributions for different exposure patterns. We find that GUTS adequately predicts survival across exposure patterns that vary over time. When toxicity is assessed for time-variable concentrations species may differ in their responses depending on the exposure profile. This can result in different species sensitivity rankings and safe levels. The interplay of exposure pattern and species sensitivity deserves systematic investigation in order to better understand how organisms respond to stress, including humans.

  2. Differences between day and nonday workers in exposure to physical and psychosocial work factors in the Danish eldercare sector

    DEFF Research Database (Denmark)

    Nabe-Nielsen, Kirsten; Tüchsen, Finn; Christensen, Karl Bang

    2009-01-01

    after control for age, job title, and workplace. CONCLUSIONS: Exposures in the work environment of Danish eldercare workers varied between shifts. In a research perspective these findings stress the importance of adequate adjustment for work factors when the health effects of shift work are studied....... Moreover, the results underscore the need for an increased awareness of work factors of special importance among nonday workers when interventions against shiftwork-related occupational disorders are designed.......OBJECTIVE: The possible interaction between individual and occupational risk factors, the need for meaningful intervention, and the demand for valid shift work research make the accumulation of adverse exposures at certain times of the day of special relevance with respect to occupational health...

  3. Prevention of mammary carcinogenesis by short-term estrogen and progestin treatments

    International Nuclear Information System (INIS)

    Rajkumar, Lakshmanaswamy; Guzman, Raphael C; Yang, Jason; Thordarson, Gudmundur; Talamantes, Frank; Nandi, Satyabrata

    2004-01-01

    Women who have undergone a full-term pregnancy before the age of 20 have one-half the risk of developing breast cancer compared with women who have never gone through a full-term pregnancy. This protective effect is observed universally among women of all ethnic groups. Parity in rats and mice also protects them against chemically induced mammary carcinogenesis. Seven-week-old virgin Lewis rats were given N-methyl-N-nitrosourea. Two weeks later the rats were treated with natural or synthetic estrogens and progestins for 7–21 days by subcutaneous implantation of silastic capsules. In our current experiment, we demonstrate that short-term sustained exposure to natural or synthetic estrogens along with progestins is effective in preventing mammary carcinogenesis in rats. Treatment with 30 mg estriol plus 30 mg progesterone for 3 weeks significantly reduced the incidence of mammary cancer. Short-term exposure to ethynyl estradiol plus megesterol acetate or norethindrone was effective in decreasing the incidence of mammary cancers. Tamoxifen plus progesterone treatment for 3 weeks was able to confer only a transient protection from mammary carcinogenesis, while 2-methoxy estradiol plus progesterone was effective in conferring protection against mammary cancers. The data obtained in the present study demonstrate that, in nulliparous rats, long-term protection against mammary carcinogenesis can be achieved by short-term treatments with natural or synthetic estrogen and progesterone combinations

  4. In-traffic air pollution exposure and CC16, blood coagulation, and inflammation markers in healthy adults.

    Science.gov (United States)

    Zuurbier, Moniek; Hoek, Gerard; Oldenwening, Marieke; Meliefste, Kees; Krop, Esmeralda; van den Hazel, Peter; Brunekreef, Bert

    2011-10-01

    Exposure to traffic-related air pollution is a risk factor for cardiovascular events, probably involving mechanisms of inflammation and coagulation. Little is known about effects of the short exposures encountered while participating in traffic. The objective of the study was to examine effects of exposure of commuters to air pollution on cardiovascular biomarkers. Thirty-four healthy adult volunteers commuted for 2 hr by bus, car, or bicycle during the morning rush hour. During the commute, exposure to particle number, particulate matter (PM) ≤ 2.5 µm in aerodynamic diameter (PM2.5), PM ≤ 10 µm in diameter (PM10), and soot was measured. We estimated inhaled doses based on heart rate monitoring. Shortly before exposure and 6 hr after exposure, blood samples were taken and analyzed for CC16 (Clara cell protein 16), blood cell count, coagulation markers, and inflammation markers. Between June 2007 and June 2008, 352 pre- and postexposure blood samples were collected on 47 test days. We used mixed models to analyze the associations between exposure and changes in health parameters. We observed no consistent associations between the air pollution exposures and doses and the various biomarkers that we investigated. Air pollution exposure during commuting was not consistently associated with acute changes in inflammation markers, blood cell counts, or blood coagulation markers.

  5. Handling of thermal paper: Implications for dermal exposure to bisphenol A and its alternatives.

    Directory of Open Access Journals (Sweden)

    Meghan R Bernier

    Full Text Available Bisphenol A (BPA is an endocrine disrupting chemical used in a wide range of consumer products including photoactive dyes used in thermal paper. Recent studies have shown that dermal absorption of BPA can occur when handling these papers. Yet, regulatory agencies have largely dismissed thermal paper as a major source of BPA exposure. Exposure estimates provided by agencies such as the European Food Safety Authority (EFSA are based on assumptions about how humans interact with this material, stating that 'typical' exposures for adults involve only one handling per day for short periods of time (30% of individuals hold thermal paper with more than three fingertips, and >60% allow the paper to touch their palm. Only 11% of the participants we observed were consistent with the EFSA model for time of contact and dermal surface area. Mathematical modeling based on handling times we measured and previously published transfer coefficients, concentrations of BPA in paper, and absorption factors indicate the most conservative estimated intake from handling thermal paper in this population is 51.1 ng/kg/day, similar to EFSA's estimates of 59 ng/kg/day from dermal exposures. Less conservative estimates, using published data on concentrations in thermal paper and transfer rates to skin, indicate that exposures are likely significantly higher. Based on our observational data, we propose that the current models for estimating dermal BPA exposures are not consistent with normal human behavior and should be reevaluated.

  6. Esophageal manometry findings and degree of acid exposure in short and long Barrett's esophagus.

    Science.gov (United States)

    Helman, Laura; Biccas, Beatriz Nunes; Lemme, Eponina M O; Novais, Paula; Fittipaldi, Viviane

    2012-01-01

    Barrett's esophagus (BE) is characterized by intestinal metaplasia in the distal esophagus and is classified as short-segment (3 cm - LSSBE). It is suggested that LSSBE is associated with more severe esophageal motor abnormalities and increased acid exposure time than SSBE. To evaluate the prevalence of esophageal manometriy abnormalities and acid exposure times in patients with SSBE and LSSBE. Barrett's esophagus patients identified by upper endoscopy and confirmed by histopathology were, retrospectively, reviewed and divided into two groups: SSBE and LSBE. Demographic data, symptom duration, prevalence of hiatal hernia, lower esophagus sphincter basal pressure, prevalence of esophageal body abnormalities and acid exposure times were evaluated. Forty-six patients with SSBE (24 males - 52.2%, mean age of 55.2 years) and 28 patients with LSBE (18 males - 64.3%, mean age of 50.5 years). Mean symptom duration was 9.9 years for SSBE and 12.9 years for LSSBE. Hiatal hernia was present in 84.2% of SSBE, 96.3% of LSBE; average lower esophagus sphincter pressure in SSBE 9.15 mm Hg, in LSBE 6.99 mm Hg; lower esophagus sphincter hypotension in SSBE was 65.9%, in LSSBE 82.1%; aperistalsis in SSBE 6.5%, LSSBE 3.6%; mild/moderate ineffective esophageal motility in SSBE 34.8%, LSBE 46.4%; severe moderate ineffective esophageal motility in SSBE 10.9%, LSBE 7,1%; nutcracker esophagus/segmental nutcracker esophagus in SSBE 8.6%, LSBE 0%; normal body in SSBE 39.1%, in LSBE 42.9%, no statistical difference for any of these values (Pmotor disorders in patients with SSBE and LSSBE. Acid reflux in upright and supine positions was more intense in LSBE.

  7. Thyroid cancer in the Marshallese: relative risk of short-lived internal emitters and external radiation exposure

    International Nuclear Information System (INIS)

    Lessard, E.T.; Brill, A.B.; Adams, W.H.

    1985-01-01

    In a study of the comparative effects of internal versus external irradiation of the thyroid in young people, we determined that the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times less thyroid cancer than did the same dose of radiation given externally. We determined this finding for a group of 85 Marshall Islands children, who were less than 10 years of age at the time of exposure and who were accidentially exposed to internal and external thyroid radiation at an average level of 1400 rad. The external risk coefficient ranged between 2.5 and 4.9 cancers per million person-rad-years at risk, and thus, from our computations, the internal risk coefficient for the Marshallese children was estimated to range between 1.0 and 1.4 cancers per million person-rad-years at risk. In contrast, for individual more than 10 years of age at the time of exposure, the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times more thyroid cancer than did the same dose of radiation given externally. The external risk coefficients for the older age groups were reported in the literature to be in the range of 1.0 to 3.3 cancers per million person-rad-years-at risk. We computed internal risk coefficients of 3.3 to 8.1 cancers per million person-rad-years at risk for adolescent and adult groups. This higher sensitivity to cancer induction in the exposed adolescents and adults, is different from that seen in other exposed groups. 14 refs., 8 tabs

  8. Hair Manganese as an Exposure Biomarker among Welders.

    Science.gov (United States)

    Reiss, Boris; Simpson, Christopher D; Baker, Marissa G; Stover, Bert; Sheppard, Lianne; Seixas, Noah S

    2016-03-01

    Quantifying exposure and dose to manganese (Mn) containing airborne particles in welding fume presents many challenges. Common biological markers such as Mn in blood or Mn in urine have not proven to be practical biomarkers even in studies where positive associations were observed. However, hair Mn (MnH) as a biomarker has the advantage over blood and urine that it is less influenced by short-term variability of Mn exposure levels because of its slow growth rate. The objective of this study was to determine whether hair can be used as a biomarker for welders exposed to manganese. Hair samples (1cm) were collected from 47 welding school students and individual air Mn (MnA) exposures were measured for each subject. MnA levels for all days were estimated with a linear mixed model using welding type as a predictor. A 30-day time-weighted average MnA (MnA30d) exposure level was calculated for each hair sample. The association between MnH and MnA30d levels was then assessed. A linear relationship was observed between log-transformed MnA30d and log-transformed MnH. Doubling MnA30d exposure levels yields a 20% (95% confidence interval: 11-29%) increase in MnH. The association was similar for hair washed following two different wash procedures designed to remove external contamination. Hair shows promise as a biomarker for inhaled Mn exposure given the presence of a significant linear association between MnH and MnA30d levels. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

  9. Sensor-triggered sampling to determine instantaneous airborne vapor exposure concentrations.

    Science.gov (United States)

    Smith, Philip A; Simmons, Michael K; Toone, Phillip

    2018-06-01

    It is difficult to measure transient airborne exposure peaks by means of integrated sampling for organic chemical vapors, even with very short-duration sampling. Selection of an appropriate time to measure an exposure peak through integrated sampling is problematic, and short-duration time-weighted average (TWA) values obtained with integrated sampling are not likely to accurately determine actual peak concentrations attained when concentrations fluctuate rapidly. Laboratory analysis for integrated exposure samples is preferred from a certainty standpoint over results derived in the field from a sensor, as a sensor user typically must overcome specificity issues and a number of potential interfering factors to obtain similarly reliable data. However, sensors are currently needed to measure intra-exposure period concentration variations (i.e., exposure peaks). In this article, the digitized signal from a photoionization detector (PID) sensor triggered collection of whole-air samples when toluene or trichloroethylene vapors attained pre-determined levels in a laboratory atmosphere generation system. Analysis by gas chromatography-mass spectrometry of whole-air samples (with both 37 and 80% relative humidity) collected using the triggering mechanism with rapidly increasing vapor concentrations showed good agreement with the triggering set point values. Whole-air samples (80% relative humidity) in canisters demonstrated acceptable 17-day storage recoveries, and acceptable precision and bias were obtained. The ability to determine exceedance of a ceiling or peak exposure standard by laboratory analysis of an instantaneously collected sample, and to simultaneously provide a calibration point to verify the correct operation of a sensor was demonstrated. This latter detail may increase the confidence in reliability of sensor data obtained across an entire exposure period.

  10. Short-term exposure to high ambient air pollution increases airway inflammation and respiratory symptoms in chronic obstructive pulmonary disease patients in Beijing, China.

    Science.gov (United States)

    Wu, Shaowei; Ni, Yang; Li, Hongyu; Pan, Lu; Yang, Di; Baccarelli, Andrea A; Deng, Furong; Chen, Yahong; Shima, Masayuki; Guo, Xinbiao

    2016-09-01

    Few studies have investigated the short-term respiratory effects of ambient air pollution in chronic obstructive pulmonary disease (COPD) patients in the context of high pollution levels in Asian cities. A panel of 23 stable COPD patients was repeatedly measured for biomarkers of airway inflammation including exhaled nitric oxide (FeNO) and exhaled hydrogen sulfide (FeH2S) (215 measurements) and recorded for daily respiratory symptoms (794person-days) in two study periods in Beijing, China in January-September 2014. Daily ambient air pollution data were obtained from nearby central air-monitoring stations. Mixed-effects models were used to estimate the associations between exposures and health measurements with adjustment for potential confounders including temperature and relative humidity. Increasing levels of air pollutants were associated with significant increases in both FeNO and FeH2S. Interquartile range (IQR) increases in PM2.5 (76.5μg/m(3), 5-day), PM10 (75.0μg/m(3), 5-day) and SO2 (45.7μg/m(3), 6-day) were associated with maximum increases in FeNO of 13.6% (95% CI: 4.8%, 23.2%), 9.2% (95% CI: 2.1%, 16.8%) and 34.2% (95% CI: 17.3%, 53.4%), respectively; and the same IQR increases in PM2.5 (6-day), PM10 (6-day) and SO2 (7-day) were associated with maximum increases in FeH2S of 11.4% (95% CI: 4.6%, 18.6%), 7.8% (95% CI: 2.3%, 13.7%) and 18.1% (95% CI: 5.5%, 32.2%), respectively. Increasing levels of air pollutants were also associated with increased odds ratios of sore throat, cough, sputum, wheeze and dyspnea. FeH2S may serve as a novel biomarker to detect adverse respiratory effects of air pollution. Our results provide potential important public health implications that ambient air pollution may pose risk to respiratory health in the context of high pollution levels in densely-populated cities in the developing world. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Peat Biomass Smoke Particle Exposure in Rats Decreases ...

    Science.gov (United States)

    Wildland fires, favored by prolonged drought and rising temperatures, generate significant amounts of ambient particulate matter (PM), which has been linked to adverse health outcomes. The eastern North Carolina peat fires of Pocosin Lake in 2008 and Pains Bay in 2011 were some of the more prominent recent wildland fires and were associated with increased cardiovascular hospitalizations. The biological impacts of peat biomass emissions and the specific mechanisms driving these responses are unclear. The purpose of this study was to investigate the cardiopulmonary responses of peat biomass smoke exposure in rats. We hypothesized that PM exposure would dose-dependently alter cardiopulmonary function. Male Sprague-Dawley rats were exposed to 30 µg (Lo PM) or 300 µg (Hi PM) of peat biomass smoke PM extracts suspended in 200 µL of saline, or saline vehicle alone by oropharyngeal aspiration (OA). Immediately following OA rats were placed in a whole-body plethysmograph and ventilatory data were recorded for 12 minutes. One day following OA, rats were anesthetized with isoflurane for ultrasound assessment of cardiovascular function. Hi PM caused decreases in expiratory timing as early as 4-6 minutes after exposure relative to Lo PM (p = 0.02) and Vehicle (p= 0.06), which resolved shortly thereafter. One day after OA, ultrasounds revealed that Hi PM exposure increased end diastolic volume (EDV) by 16% (p = 0.03) over Vehicle and 13% (p = 0.06) over Lo PM. In addition,

  12. Responses of primary cultured haemocytes from the marine gastropod Haliotis tuberculata under 10-day exposure to cadmium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Latire, Thomas; Le Pabic, Charles; Mottin, Elmina; Mottier, Antoine; Costil, Katherine; Koueta, Noussithe; Lebel, Jean-Marc [UMR 100 IFREMER ' Physiologie et Ecophysiologie des Mollusques Marins' - IFR 146 ICORE - IBFA - Universite de Caen Basse-Normandie, Campus 1, Science C, Esplanade de la Paix, 14032 Caen cedex (France); Serpentini, Antoine, E-mail: antoine.serpentini@unicaen.fr [UMR 100 IFREMER ' Physiologie et Ecophysiologie des Mollusques Marins' - IFR 146 ICORE - IBFA - Universite de Caen Basse-Normandie, Campus 1, Science C, Esplanade de la Paix, 14032 Caen cedex (France)

    2012-03-15

    Among metals, cadmium, a non-essential element, is an important pollutant that is released into aquatic environments. Due to its persistence and bioaccumulation, this metal has been shown to exert immunological effects on organisms. The objective of the present study was to investigate the in vitro effects of cadmium chloride using a haemocyte primary culture from the European abalone, Haliotis tuberculata. Most studies have maintained viable haemocytes in vitro for periods ranging from several hours to several days during acute exposures. Few investigations have reported the effects of metals using longer in vitro exposures, which are more realistic with regard to mimicking environmental conditions. In this study, we exposed abalone haemocytes to concentrations from 0.5 to 50,000 {mu}g L{sup -1} of CdCl{sub 2} for 10 days. The effects of cadmium chloride were reflected in a significant decrease in the number of viable cells and morphological modifications in a concentration-dependent manner beginning at a concentration of 500 {mu}g L{sup -1} as well as in some physiological processes, such as phagocytotic activity and the number of lysosome-positive cells. In contrast, phenoloxidase (PO) activity and reactive oxygen species (ROS) production were increased beginning at a concentration of 5 {mu}g L{sup -1}, which is consistent with environmental concentrations in polluted sites. For PO activity and ROS production, maximally 9-fold and 130% inductions, respectively, were recorded under the highest dose. These results thus indicate that cadmium chloride alters immune parameters of abalone haemocytes and that the long-term (10 days) primary culture system used here represents a suitable, sensitive in vitro model for assessing cytotoxic responses.

  13. Responses of primary cultured haemocytes from the marine gastropod Haliotis tuberculata under 10-day exposure to cadmium chloride

    International Nuclear Information System (INIS)

    Latire, Thomas; Le Pabic, Charles; Mottin, Elmina; Mottier, Antoine; Costil, Katherine; Koueta, Noussithé; Lebel, Jean-Marc; Serpentini, Antoine

    2012-01-01

    Among metals, cadmium, a non-essential element, is an important pollutant that is released into aquatic environments. Due to its persistence and bioaccumulation, this metal has been shown to exert immunological effects on organisms. The objective of the present study was to investigate the in vitro effects of cadmium chloride using a haemocyte primary culture from the European abalone, Haliotis tuberculata. Most studies have maintained viable haemocytes in vitro for periods ranging from several hours to several days during acute exposures. Few investigations have reported the effects of metals using longer in vitro exposures, which are more realistic with regard to mimicking environmental conditions. In this study, we exposed abalone haemocytes to concentrations from 0.5 to 50,000 μg L −1 of CdCl 2 for 10 days. The effects of cadmium chloride were reflected in a significant decrease in the number of viable cells and morphological modifications in a concentration-dependent manner beginning at a concentration of 500 μg L −1 as well as in some physiological processes, such as phagocytotic activity and the number of lysosome-positive cells. In contrast, phenoloxidase (PO) activity and reactive oxygen species (ROS) production were increased beginning at a concentration of 5 μg L −1 , which is consistent with environmental concentrations in polluted sites. For PO activity and ROS production, maximally 9-fold and 130% inductions, respectively, were recorded under the highest dose. These results thus indicate that cadmium chloride alters immune parameters of abalone haemocytes and that the long-term (10 days) primary culture system used here represents a suitable, sensitive in vitro model for assessing cytotoxic responses.

  14. The Traces of “New Character” in Uzbek Short Story Heroes Based on Two Examples of Uzbek Short Stories of the Present Day

    Directory of Open Access Journals (Sweden)

    Veli Savaş Yelok

    2014-12-01

    Full Text Available The era following the Uzbek independence resulted in a renaissance in Uzbek life. This process in which a renaissance was experienced, also affected the material and moral elements that shape their view of life. When this situation affected the way people understand life, this reform of the Uzbek people naturally formed “the new era”. This new era demanded new ways of thinking from those who lived in that era. The effect of this development and change on people’s minds and their way of understanding and thinkingand its description found itself in literary life. In the short stories published following the independence, the spirit of the time and the different fates of those people who lived in that era were reflected. As a result, writers created the heroes of today through the change experienced by people in their inner world who lived in the same era as the writers. As a general principle, creating a hero is seen as the first issue in the literature of every era. This is so because the hero in the work of literature is the tool that reflects the inner and outer world of the people of a specific era. All the nice and ugly things in a person’s life -starting from the person’s lifestyle and continuing to the end of his life- are passed onto the hero’s thoughts and actions. Describing the changes constantly observed in a hero’s character, reflecting these by forming a direct relationship with the era is comparatively easier in a short story when compared to other genres. In this article, information on the development of short story in present day Uzbek Literature is presented. In addition, the reflection of “the person of the new era” observed in the heroes in the stories “The Author” and “The Trick of Gumshoe Jacob” written by Erkin A‘zam and Xurshid Dostmuhammad who have gained the admiration of readers in their works following the independence is studied.

  15. Short-term exposure of arsenite disrupted thyroid endocrine system and altered gene transcription in the HPT axis in zebrafish.

    Science.gov (United States)

    Sun, Hong-Jie; Li, Hong-Bo; Xiang, Ping; Zhang, Xiaowei; Ma, Lena Q

    2015-10-01

    Arsenic (As) pollution in aquatic environment may adversely impact fish health by disrupting their thyroid hormone homeostasis. In this study, we explored the effect of short-term exposure of arsenite (AsIII) on thyroid endocrine system in zebrafish. We measured As concentrations, As speciation, and thyroid hormone thyroxine levels in whole zebrafish, oxidative stress (H2O2) and damage (MDA) in the liver, and gene transcription in hypothalamic-pituitary-thyroid (HPT) axis in the brain and liver tissues of zebrafish after exposing to different AsIII concentrations for 48 h. Result indicated that exposure to AsIII increased inorganic As in zebrafish to 0.46-0.72 mg kg(-1), induced oxidative stress with H2O2 being increased by 1.4-2.5 times and caused oxidative damage with MDA being augmented by 1.6 times. AsIII exposure increased thyroxine levels by 1.3-1.4 times and modulated gene transcription in HPT axis. Our study showed AsIII caused oxidative damage, affected thyroid endocrine system and altered gene transcription in HPT axis in zebrafish. Published by Elsevier Ltd.

  16. Short-term nighttime wind turbine noise and cardiovascular events: A nationwide case-crossover study from Denmark.

    Science.gov (United States)

    Poulsen, Aslak Harbo; Raaschou-Nielsen, Ole; Peña, Alfredo; Hahmann, Andrea N; Nordsborg, Rikke Baastrup; Ketzel, Matthias; Brandt, Jørgen; Sørensen, Mette

    2018-05-01

    The number of people exposed to wind turbine noise (WTN) is increasing. WTN is reported as more annoying than traffic noise at similar levels. Long-term exposure to traffic noise has consistently been associated with cardiovascular disease, whereas effects of short-term exposure are much less investigated due to little day-to-day variation of e.g. road traffic noise. WTN varies considerably due to changing weather conditions allowing investigation of short-term effects of WTN on cardiovascular events. We identified all hospitalisations and deaths from stroke (16,913 cases) and myocardial infarction (MI) (17,559 cases) among Danes exposed to WTN between 1982 and 2013. We applied a time-stratified, case-crossover design. Using detailed data on wind turbine type and hourly wind data at each wind turbine, we simulated mean nighttime outdoor (10-10,000 Hz) and nighttime low frequency (LF) indoor WTN (10-160 Hz) over the 4 days preceding diagnosis and reference days. For indoor LF WTN between 10 and 15 dB(A) and above 15 dB(A), odds ratios (ORs) for MI were 1.27 (95% confidence interval (CI): 0.97-1.67; cases = 198) and 1.62 (95% CI: 0.76-3.45; cases = 21), respectively, when compared to indoor LF WTN below 5 dB(A). For stroke, corresponding ORs were 1.17 (95% CI: 0.95-1.69; cases = 166) and 2.30 (95% CI: 0.96-5.50; cases = 15). The elevated ORs above 15 dB(A) persisted across sensitivity analyses. When looking at specific lag times, noise exposure one day before MI events and three days before stroke events were associated with the highest ORs. For outdoor WTN at night, we observed both increased and decreased risk estimates. This study did not provide conclusive evidence of an association between WTN and MI or stroke. It does however suggest that indoor LF WTN at night may trigger cardiovascular events, whereas these events seemed largely unaffected by nighttime outdoor WTN. These findings need reproduction, as they were based on few cases

  17. Depression-like effect of prenatal buprenorphine exposure in rats.

    Directory of Open Access Journals (Sweden)

    Chih-Jen Hung

    Full Text Available Studies indicate that perinatal opioid exposure produces a variety of short- and long-term neurobehavioral consequences. However, the precise modes of action are incompletely understood. Buprenorphine, a mixed agonist/antagonist at the opioid receptors, is currently being used in clinical trials for managing pregnant opioid addicts. This study provides evidence of depression-like consequence following prenatal exposure to supra-therapeutic dose of buprenorphine and sheds light on potential mechanisms of action in a rat model involving administration of intraperitoneal injection to pregnant Sprague-Dawley rats starting from gestation day 7 and lasting for 14 days. Results showed that pups at postnatal day 21 but not the dams had worse parameters of depression-like neurobehaviors using a forced swimming test and tail suspension test, independent of gender. Neurobehavioral changes were accompanied by elevation of oxidative stress, reduction of plasma levels of brain-derived neurotrophic factor (BDNF and serotonin, and attenuation of tropomyosin-related kinase receptor type B (TrkB phosphorylation, extracellular signal-regulated kinase (ERK phosphorylation, protein kinase A activity, cAMP response element-binding protein (CREB phosphorylation, and CREB DNA-binding activity. Since BDNF/serotonin and CREB signaling could orchestrate a positive feedback loop, our findings suggest that the induction of oxidative stress, reduction of BDNF and serotonin expression, and attenuation of CREB signaling induced by prenatal exposure to supra-therapeutic dose of buprenorphine provide evidence of potential mechanism for the development of depression-like neurobehavior.

  18. Real-time exposure fusion on a mobile computer

    CSIR Research Space (South Africa)

    Bachoo, AK

    2009-12-01

    Full Text Available information in these scenarios. An image captured using a short exposure time will not saturate bright image re- gions while an image captured with a long exposure time will show more detail in the dark regions. The pixel depth provided by most camera.... The auto exposure also creates strong blown-out highlights in the foreground (the grass patch). The short shutter time (Exposure 1) correctly exposes the grass while the long shutter time (Exposure 3) is able to correctly expose the camouflaged dummy...

  19. Long-term failure of alveologenesis after an early short-term exposure to a PDGF-receptor antagonist.

    Science.gov (United States)

    Lau, Mandy; Masood, Azhar; Yi, Man; Belcastro, Rosetta; Li, Jun; Tanswell, A Keith

    2011-04-01

    Survivors of moderate-to-severe bronchopulmonary dysplasia have impaired alveologenesis lasting at least into early adult life. The mechanisms underlying this long-term effect are unknown. We hypothesized that short-term inhibition of growth factor-mediated early alveolar formation would result in a long-term impairment of subsequent alveologenesis. Neonatal rats were injected daily with the platelet-derived growth factor (PDGF) receptor antagonist, imatinib mesylate, from day 1-7 of life, to inhibit the early alveolar formation occurring by in-growth of secondary crests into precursor saccules. The pups were then allowed to recover for 7, 14, 21, or 58 days. In imatinib-treated pups, DNA synthesis in total lung cells, and specifically in cells of secondary crests, was reduced at day 8 of life, had rebounded on day 14 of life but was then again reduced by day 28 of life. At day 8 of life, imatinib-treated pups had impaired alveologenesis as reflected by a decrease in secondary crests, an increase in alveolar size, and an overall decrease in both estimated alveolar number and generations compared with age-matched controls. No meaningful recovery was observed, even after a 21- or 58-day recovery period. The lungs of imatinib-treated pups had increased fibulin-5 content and an abnormal deposition of elastin. We conclude that reduced signaling through the PDGF pathways, at an early stage of alveologenesis, can result in long-lasting changes in lung architecture. A likely mechanism is through impaired formation of the elastin scaffold required for alveolarization.

  20. Cyto-architectural Alterations in the Corpuscles of Stannius of Stinging Catfish Heteropneustes fossilis after Exposure to a Botanical Pesticide (Nerium indicum

    Directory of Open Access Journals (Sweden)

    ManiRam Prasad

    2014-03-01

    Full Text Available Background: This investigation describes the cyto-architectural alterations observed in the corpuscles of Stannius of stinging catfish Heteropneustes fossilis after treatment with a botanical pesticide Nerium indicum. Methods: Heteropneustes fossilis were subjected to 11.27 and 2.81 mg/L of Nerium indicum leaf extract over short- and long-term exposure periods, respectively. Blood was collected for calcium analysis and corpuscles of Stannius (CS gland were fixed on 24, 48, 72 and 96 h in the short-term experiment and after 7, 14, 21, and 28 days in the long-term experiment. Results: Serum calcium levels decreased from 48 h to 96 h. CS remains unaffected till 72 h. After the 96-hour treatment, increased granulation was observed in AF- positive cells. Nuclear volume of these cells exhibited no change throughout the short-term treatment. Slight increases in nuclear volume of AF-negative cells were recorded after 96 h. Nerium indicum caused decreases in serum calcium levels of H. fossilis from day 14 to 28. CS exhibited no alterations up to 14 days of exposure. AF-positive cells of CS depicted increased granulation after 21 days of treatment. Nuclear volume of these cells exhibited a slight decrease from day 21 to 28. Heavy accumulation of AF-positive granules was observed and few degenerating cells were noticed. Nuclear volume of AF-negative cells increased after 21 and 28 days of treatment. Vacuolization and degeneration occurred in certain places. Conclusion: It is inferred from the present study that the botanical pesticide Nerium indicum induced severe changes in the corpuscles of Stannius of catfish.

  1. Differences between day and nonday workers in exposure to physical and psychosocial work factors in the Danish eldercare sector.

    Science.gov (United States)

    Nabe-Nielsen, Kirsten; Tüchsen, Finn; Christensen, Karl Bang; Garde, Anne Helene; Diderichsen, Finn

    2009-01-01

    The possible interaction between individual and occupational risk factors, the need for meaningful intervention, and the demand for valid shift work research make the accumulation of adverse exposures at certain times of the day of special relevance with respect to occupational health. The aim of the present study was therefore to examine whether there was a clustering of detrimental work factors among female eldercare workers in fixed evening or fixed night shifts when they are compared with workers in fixed day shifts. This cross-sectional, questionnaire-based study was conducted among 4590 female health care workers in the Danish eldercare sector. The participants worked in nursing homes, in home care, or in both. They answered questions on job demands, job control, and social support, together with questions on physical and psychological violence, physical workload, and passive smoking. We found that-compared with day workers-fixed nonday workers were more exposed to low job control, low support from leaders, physical and psychological violence, and high physical demands. Nonday workers were, however, less exposed to high demands. These differences remained after control for age, job title, and workplace. Exposures in the work environment of Danish eldercare workers varied between shifts. In a research perspective these findings stress the importance of adequate adjustment for work factors when the health effects of shift work are studied. Moreover, the results underscore the need for an increased awareness of work factors of special importance among nonday workers when interventions against shiftwork-related occupational disorders are designed.

  2. Thyroid cancer in the Marshallese: relative risk of short-lived internal emitters and external radiation exposure

    International Nuclear Information System (INIS)

    Lessard, E.T.; Brill, A.B.; Adams, W.H.

    1986-01-01

    In a study of the comparative effects of internal versus external irradiation of the thyroid in young people, we determined that the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times less thyroid cancer than did the same dose of radiation given externally. The authors determined this finding for a group of 85 Marshall Islands children, who were less than 10 years of age at the time of exposure and who were accidentally exposed to internal and external thyroid radiation at an average level of 1400 rad. The external risk coefficient ranged between 2.5 and 4.9 cancers per million person-rad-years at risk, and thus, from our computations, the internal risk coefficient for the Marshallese children was estimated to range between 1.0 and 1.4 cancers per million person-rad-years at risk. In contrast, for individuals more than 10 years of age at the time of exposure, the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times more thyroid cancer than did the same dose of radiation given externally. The external risk coefficients for the older age groups were reported in the above literature to be in the range of 1.0 to 3.3 cancers per million person-rad-years-at risk. The authors computed internal risk coefficients of 3.3 to 8.1 cancers per million person-rad-years at risk for adolescent and adult groups. This higher sensitivity to cancer induction in the exposed adolescents and adults, is different from that seen in other exposed groups. The small number of cancers in the exposed population and the influence of increased levels of TSH, nonuniform irradiation of the thyroid, and thyroid cell killing at high dose make it difficult to draw firm conclusions from these studies. 14 references, 8 tables

  3. High-dose, short-term exposure of mice to perfluorooctanesulfonate (PFOS) or perfluorooctanoate (PFOA) affects the number of circulating neutrophils differently, but enhances the inflammatory responses of macrophages to lipopolysaccharide (LPS) in a similar fashion.

    Science.gov (United States)

    Qazi, Mousumi R; Bogdanska, Jasna; Butenhoff, John L; Nelson, B Dean; DePierre, Joseph W; Abedi-Valugerdi, Manuchehr

    2009-08-21

    Having found previously that high-dose, short-term dietary exposure of mice to perfluorooctanesulfonate (PFOS) or perfluorooctanoate (PFOA) suppresses adaptive immunity, in the present study we characterize the effects of these fluorochemicals on the innate immune system. Male C57BL/6 mice receiving 0.02% (w/w) PFOS or PFOA in their diet for 10 days exhibited a significant reduction in the numbers of total white blood cells (WBC), involving lymphopenia in both cases, but neutropenia only in response to treatment with PFOA. Moreover, both compounds also markedly reduced the number of macrophages (CD11b(+) cells) in the bone marrow, but not in the spleen or peritoneal cavity. The ex vivo production of tumor necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6) by peritoneal macrophages isolated from animals treated with PFOA or PFOS was increased modestly. Moreover, both fluorochemicals markedly enhanced the ex vivo production of these same cytokines by peritoneal and bone marrow macrophages stimulated either in vitro or in vivo with lipopolysaccharide (LPS); whereas there was no such effect on splenic macrophages. The serum levels of these inflammatory cytokines observed in response to in vivo stimulation with LPS were elevated substantially by prior exposure to PFOA, but not by PFOS. None of these parameters of innate immunity were altered in animals receiving a dietary dose of these compounds that was 20-fold lower (0.001%, w/w). These findings reveal that in addition to suppressing adaptive immunity, high-dose, short-term exposure of mice to either PFOS or PFOA augments inflammatory responses to LPS, a potent activator of innate immunity.

  4. Adolescent exposure to Bisphenol-A increases anxiety and sucrose preference but impairs spatial memory in rats independent of sex.

    Science.gov (United States)

    Diaz Weinstein, Samantha; Villafane, Joseph J; Juliano, Nicole; Bowman, Rachel E

    2013-09-05

    The endocrine disruptor Bisphenol-A (BPA) has been shown to modulate estrogenic, androgenic, and anti-androgenic effects. The effects of BPA exposure during early organizational periods of development have been well documented. The current study focuses on the effects of short term, low-dose BPA exposure on anxiety, spatial memory and sucrose preference in adolescent rats. Seven week old Sprague Dawley rats (n=18 male, n=18 female) received daily subcutaneous injections (40 µg/kg body weight) of BPA or vehicle for 12 days. Starting on day 6 of injections, subjects were tested on the elevated plus maze which provides a measure of anxiety, the open field test which provides a measure of anxiety and locomotor activity, and object placement, a measure of spatial memory. On the twelfth day of BPA administration, sucrose preference was tested using a standard two-bottle choice (tap versus sucrose solution). All rats gained weight during the study; there was a main effect of sex, but not BPA treatment on body weight. The results indicate that BPA exposure, regardless of sex, increased anxiety on both the elevated plus maze and open field. Spatial memory was impaired on the object recognition task with BPA animals spending significant less time with the object in the novel location than controls. Finally, a significant increase in sucrose consumption for both male and female subjects exposed to BPA was observed. The current data shows that short term BPA exposure, below the current reference safe daily limit of 50 µg/kg day set by the United States Environmental Protection Agency, during adolescent development increases anxiety, impairs spatial memory, and increases sucrose consumption independent of sex. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Applicability of the black slug Arion ater for monitoring exposure to polycyclic aromatic hydrocarbons and their subsequent bioactivation into DNA binding metabolites

    NARCIS (Netherlands)

    Hamers, T.; Kalis, E.J.J.; Berg, van den J.H.J.; Maas, L.M.; Schooten, van F.J.; Murk, A.J.

    2004-01-01

    The applicability of terrestrial black slugs Arion ater (Mollusca, Gastropoda) was studied for biomonitoring environmental exposure to polycyclic aromatic hydrocarbons (PAHs). In laboratory experiments, slugs were orally exposed to benzo[a]pyrene (BaP) for a short term (3 days) or a long term (119

  6. Male reproductive health under threat: Short term exposure to radiofrequency radiations emitted by common mobile jammers

    Science.gov (United States)

    Mortazavi, SMJ; Parsanezhad, ME; Kazempour, M; Ghahramani, P; Mortazavi, AR; Davari, M

    2013-01-01

    BACKGROUND: Modern life prompted man to increasingly generate, transmit and use electricity that leads to exposure to different levels of electromagnetic fields (EMFs). Substantial evidence indicates that exposure to common sources of EMF such as mobile phones, laptops or wireless internet-connected laptops decreases human semen quality. In some countries, mobile jammers are occasionally used in offices, shrines, conference rooms and cinemas to block the signal. AIMS: To the best of our knowledge, this is the first study to investigate the effect of short term exposure of human sperm samples to radiofrequency (RF) radiations emitted by common mobile jammers. SUBJECTS AND METHODS: Fresh semen samples were collected by masturbation from 30 healthy donors who had referred to Infertility Treatment Center at the Mother and Child Hospital with their wives. Female problem was diagnosed as the reason for infertility in these couples. STATISTICAL ANALYSIS: T-test and analysis of variance were used to show statistical significance. RESULTS: The motility of sperm samples exposed to jammer RF radiation for 2 or 4 h were significantly lower than those of sham-exposed samples. These findings lead us to the conclusion that mobile jammers may significantly decrease sperm motility and the couples’ chances of conception. CONCLUSION: Based on these results, it can be suggested that in countries that have not banned mobile jammer use, legislations should be urgently passed to restrict the use of these signal blocking devices in public or private places. PMID:24082653

  7. Male reproductive health under threat: Short term exposure to radiofrequency radiations emitted by common mobile jammers

    Directory of Open Access Journals (Sweden)

    SMJ Mortazavi

    2013-01-01

    Full Text Available Background: Modern life prompted man to increasingly generate, transmit and use electricity that leads to exposure to different levels of electromagnetic fields (EMFs. Substantial evidence indicates that exposure to common sources of EMF such as mobile phones, laptops or wireless internet-connected laptops decreases human semen quality. In some countries, mobile jammers are occasionally used in offices, shrines, conference rooms and cinemas to block the signal. Aims: To the best of our knowledge, this is the first study to investigate the effect of short term exposure of human sperm samples to radiofrequency (RF radiations emitted by common mobile jammers. Subjects and Methods: Fresh semen samples were collected by masturbation from 30 healthy donors who had referred to Infertility Treatment Center at the Mother and Child Hospital with their wives. Female problem was diagnosed as the reason for infertility in these couples. Statistical Analysis: T-test and analysis of variance were used to show statistical significance. Results: The motility of sperm samples exposed to jammer RF radiation for 2 or 4 h were significantly lower than those of sham-exposed samples. These findings lead us to the conclusion that mobile jammers may significantly decrease sperm motility and the couples′ chances of conception. Conclusion: Based on these results, it can be suggested that in countries that have not banned mobile jammer use, legislations should be urgently passed to restrict the use of these signal blocking devices in public or private places.

  8. An overview of organically bound tritium experiments in plants following a short atmospheric HTO exposure.

    Science.gov (United States)

    Galeriu, D; Melintescu, A; Strack, S; Atarashi-Andoh, M; Kim, S B

    2013-04-01

    The need for a less conservative, but reliable risk assessment of accidental tritium releases is emphasized in the present debate on the nuclear energy future. The development of a standard conceptual model for accidental tritium releases must be based on the process level analysis and the appropriate experimental database. Tritium transfer from atmosphere to plants and the subsequent conversion into organically bound tritium (OBT) strongly depends on the plant characteristics, seasons, and meteorological conditions, which have a large variability. The present study presents an overview of the relevant experimental data for the short term exposure, including the unpublished information, also. Plenty of experimental data is provided for wheat, rice, and soybean and some for potato, bean, cherry tomato, radish, cabbage, and tangerine as well. Tritiated water (HTO) uptake by plants during the daytime and nighttime has an important role in further OBT synthesis. OBT formation in crops depends on the development stage, length, and condition of exposure. OBT translocation to the edible plant parts differs between the crops analyzed. OBT formation during the nighttime is comparable with that during the daytime. The present study is a preliminary step for the development of a robust model of crop contamination after an HTO accidental release. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Evaluation of the deposition, translocation and pathological response of brake dust with and without added chrysotile in comparison to crocidolite asbestos following short-term inhalation: Interim results

    International Nuclear Information System (INIS)

    Bernstein, David M.; Rogers, Rick; Sepulveda, Rosalina; Kunzendorf, Peter; Bellmann, Bernd; Ernst, Heinrich; Phillips, James I.

    2014-01-01

    Chrysotile has been frequently used in the past in manufacturing brakes and continues to be used in brakes in many countries. This study was designed to provide an understanding of the biokinetics and potential toxicology following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6 h/day for 5 days to either brake dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake dust or crocidolite asbestos. No significant pathological response was observed at any time point in either the brake dust or chrysotile/brake dust exposure groups. The long chrysotile fibers (> 20 μm) cleared quickly with T 1/2 estimated as 30 and 33 days, respectively in the brake dust and the chrysotile/brake dust exposure groups. In contrast, the long crocidolite fibers had a T 1/2 > 1000 days and initiated a rapid inflammatory response in the lung following exposure resulting in a 5-fold increase in fibrotic response within 91 days. These results provide support that brake dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung following short term inhalation. - Highlights: • We evaluated brake dust w/wo added chrysotile in comparison to crocidolite asbestos. • Persistence, translocation, pathological response in the lung and pleural cavity. • Chrysotile cleared rapidly from the lung while the crocidolite asbestos persisted. • No significant pathology observed at any time point in the brake-dust groups. • Crocidolite produced pathological response - Wagner 4 interstitial fibrosis by 32d

  10. Response of rat lung tissue to short-term hyperoxia: a proteomic approach.

    Science.gov (United States)

    Spelten, Oliver; Wetsch, Wolfgang A; Wrettos, Georg; Kalenka, Armin; Hinkelbein, Jochen

    2013-11-01

    An inspiratory oxygen fraction of 1.0 is often required to avoid hypoxia both in many pre- and in-hospital situations. On the other hand, hyperoxia may lead to deleterious consequences (cell growth inhibition, inflammation, and apoptosis) for numerous tissues including the lung. Whereas clinical effects of hyperoxic lung injury are well known, its impact on the expression of lung proteins has not yet been evaluated sufficiently. The aim of this study was to analyze time-dependent alterations of protein expression in rat lung tissue after short-term normobaric hyperoxia (NH). After approval of the local ethics committee for animal research, N = 36 Wistar rats were randomized into six different groups: three groups with NH with exposure to 100 % oxygen for 3 h and three groups with normobaric normoxia (NN) with exposure to room air (21 % oxygen). After the end of the experiments, lungs were removed immediately (NH0 and NN0), after 3 days (NH3 and NN3) and after 7 days (NH7 and NN7). Lung lysates were analyzed by two-dimensional gel electrophoresis (2D-GE) followed by peptide mass fingerprinting using mass spectrometry. Statistical analysis was performed with Delta 2D (DECODON GmbH, Greifswald, Germany; ANOVA, Bonferroni correction, p pO2 was significantly higher in NH-groups compared to NN-groups (581 ± 28 vs. 98 ± 12 mmHg; p < 0.01), all other physiological parameters did not differ. Expression of 14 proteins were significantly altered: two proteins were up-regulated and 12 proteins were down-regulated. Even though NH was comparatively short termed, significant alterations in lung protein expression could be demonstrated up to 7 days after hyperoxia. The identified proteins indicate an association with cell growth inhibition, regulation of apoptosis, and approval of structural cell integrity.

  11. Enhanced flowering of the F1 long-day strawberry cultivars ‘Tarpan’ and ‘Gasana’ with nitrogen and daylength management

    Directory of Open Access Journals (Sweden)

    Edward F. Durner

    2016-12-01

    Full Text Available Interest in sustainable self-sufficiency, particularly when considering produce has increased. Strawberries, especially particularly the seed propagated, long-day, F1 hybrids such as ‘Tarpan’ and ‘Gasana’, fit self-sufficient, sustainable production models well. They provide aesthetic as well as culinary benefits producing colorful, attractive blossoms and flavorful fruit. To determine if ‘Tarpan’ and ‘Gasana’ flowering would respond to photoperiod and nitrogen, seedlings were fertilized with 100 or 800 ppm nitrogen for 4 weeks in September beginning one week after exposure to either short days, the natural photoperiod, or long days, the natural photoperiod supplemented with 24 hours of incandescent radiation. Plants were then greenhouse forced under both photoperiods and floral phenology evaluated. Photoperiod and N fertility during floral initiation in September affected subsequent flowering of both cultivars. The response was rapid with significant differences observed 4 weeks after the commencement of treatment. Both cultivars responded with increased rate (enhanced precocity and intensity (enhanced inflorescence/flower number of flowering with elevated N. In ‘Gasana’ elevated N accelerated flowering by 2–3 weeks. There was a slight acceleration of flowering in lower N plants with long-day forcing, however, elevated N was much more effective in accelerating flowering than long-day forcing. In ‘Tarpan’, long-day forcing and elevated N were equally effective in accelerating flowering. Inflorescence production per plant or crown and the number of flowers per plant were enhanced with elevated N in both cultivars. Long-day forcing stimulated the number of inflorescences produced per crown in both cultivars. The number of flowers per plant in ‘Tarpan’ was also enhanced by long-day initiation or forcing. Elevated N, short-day initiation or long-day forcing enhanced the number of flowers per inflorescence in

  12. Assessment of Human Exposure to Magnetic Fields Produced by Domestic Appliances (invited paper)

    International Nuclear Information System (INIS)

    Preece, A.W.; Kaune, W.T.; Grainger, P.; Golding, J.

    1999-01-01

    A study of 50 homes and their appliances examined whether a detailed appliance-use questionnaire and survey would yield data comparable with direct personal monitoring. This was coupled with direct measurement of the appliances in use to determine the field at 50 cm and 1 m. The findings were that individual time-weighted average (TWA) exposures calculated from questionnaire and activity diaries in conjunction with the appliance magnetic field were unrelated to actual personal exposure measurement. It was concluded that questionnaires are of little or no value for TWA estimation. However, peak exposure and short-term temporal variability could be modelled in subjects spending at least 15 min per day within 1 m of an operating microwave cooker or conventional cooker. This method could be extended to other appliances. (author)

  13. Multigenerational contaminant exposures produce non-monotonic, transgenerational responses in Daphnia magna

    International Nuclear Information System (INIS)

    Kimberly, David A.; Salice, Christopher J.

    2015-01-01

    Generally, ecotoxicologists rely on short-term tests that assume populations to be static. Conversely, natural populations may be exposed to the same stressors for many generations, which can alter tolerance to the same (or other) stressors. The objective of this study was to improve our understanding of how multigenerational stressors alter life history traits and stressor tolerance. After continuously exposing Daphnia magna to cadmium for 120 days, we assessed life history traits and conducted a challenge at higher temperature and cadmium concentrations. Predictably, individuals exposed to cadmium showed an overall decrease in reproductive output compared to controls. Interestingly, control D. magna were the most cadmium tolerant to novel cadmium, followed by those exposed to high cadmium. Our data suggest that long-term exposure to cadmium alter tolerance traits in a non-monotonic way. Because we observed effects after one-generation removal from cadmium, transgenerational effects may be possible as a result of multigenerational exposure. - Highlights: • Daphnia magna exposed to cadmium for 120 days. • D. magna exposed to cadmium had decreased reproductive output. • Control D. magna were most cadmium tolerant to novel cadmium stress. • Long-term exposure to cadmium alter tolerance traits in a non-monotonic way. • Transgenerational effects observed as a result of multigenerational exposure. - Adverse effects of long-term cadmium exposure persist into cadmium free conditions, as seen by non-monotonic responses when exposed to novel stress one generation removed.

  14. UV exposure in cars.

    Science.gov (United States)

    Moehrle, Matthias; Soballa, Martin; Korn, Manfred

    2003-08-01

    There is increasing knowledge about the hazards of solar and ultraviolet (UV) radiation to humans. Although people spend a significant time in cars, data on UV exposure during traveling are lacking. The aim of this study was to obtain basic information on personal UV exposure in cars. UV transmission of car glass samples, windscreen, side and back windows and sunroof, was determined. UV exposure of passengers was evaluated in seven German middle-class cars, fitted with three different types of car windows. UV doses were measured with open or closed windows/sunroof of Mercedes-Benz E 220 T, E 320, and S 500, and in an open convertible car (Mercedes-Benz CLK). Bacillus subtilis spore film dosimeters (Viospor) were attached to the front, vertex, cheeks, upper arms, forearms and thighs of 'adult' and 'child' dummies. UV wavelengths longer than >335 nm were transmitted through car windows, and UV irradiation >380 nm was transmitted through compound glass windscreens. There was some variation in the spectral transmission of side windows according to the type of glass. On the arms, UV exposure was 3-4% of ambient radiation when the car windows were shut, and 25-31% of ambient radiation when the windows were open. In the open convertible car, the relative personal doses reached 62% of ambient radiation. The car glass types examined offer substantial protection against short-wave UV radiation. Professional drivers should keep car windows closed on sunny days to reduce occupational UV exposure. In individuals with polymorphic light eruption, produced by long-wave UVA, additional protection by plastic films, clothes or sunscreens appears necessary.

  15. Health impact of exposure to fine particles. Epidemiology of short-term effects

    International Nuclear Information System (INIS)

    Peters, Annette; Wichmann, H.-Erich; Univ. Muenchen; Heinrich, Joachim

    2002-01-01

    Epidemiological studies on short-term effects of fine particles are investigating whether morbidity or mortality increase on days with high particle concentrations. Multi-center studies have shown on a daily basis that there is an increase in morbidity and/or mortality in association with particle concentrations. Studies on the effects of particles on the respiratory tract have indicated that there is an impact of particles at their place of deposition. In addition, numerous studies have revealed that particles also have effects on the cardiovascular system, including acute-phase reactions, increased hospital admissions, and also an increase in cardiovascular disease mortality in association with elevated particle concentrations. For PM 10 consistent effects were found. Furthermore, the analyses showed that no threshold value could be established, but a linear dose-effect relation. Studies measuring PM 2.5 point to fine particles being mainly responsible for these effects. Current studies show that in addition to fine particles, ultra-fine particles can cause further health effects. (orig.) [de

  16. Inheritance of late flowering in natural variants of soybean cultivars under short-day conditions

    Directory of Open Access Journals (Sweden)

    Valeria Carpentieri-Pipolo

    2014-10-01

    Full Text Available The objective of this work was to determine the inheritance of the long juvenile period trait in natural variants of the Doko, BR 9 (Savana, Davis, Embrapa 1 (IAS 5RC, and BR 16 soybean cultivars. Complete diallel crosses were made between the Doko and BR 16 cultivars and their variants. A 3:1 segregation ratio was observed in the F2 populations of the 'Doko' x Doko-18T, 'Doko' x Doko-Milionária, 'Davis' x São Carlos, and 'BR 9 (Savana' x MABR92-836 (Savanão crosses, indicating that the long juvenile period trait is controlled by a pair of recessive genes. The difference in late flowering between the Doko cultivar and both of its variants was caused by a recessive spontaneous mutation at the same genetic locus. However, the variants Doko-18T and Doko-Milionária are identical mutants that share a pair of genes that control the long juvenile period under short-day conditions. These mutants can be used in breeding programs to develop cultivars adapted to low-latitude tropical regions.

  17. Preoperative biological therapy and short-term outcomes of abdominal surgery in patients with inflammatory bowel disease.

    Science.gov (United States)

    Waterman, Matti; Xu, Wei; Dinani, Amreen; Steinhart, A Hillary; Croitoru, Kenneth; Nguyen, Geoffrey C; McLeod, Robin S; Greenberg, Gordon R; Cohen, Zane; Silverberg, Mark S

    2013-03-01

    Previous investigations of short-term outcomes after preoperative exposure to biological therapy in inflammatory bowel disease (IBD) were conflicting. The authors aimed to assess postoperative outcomes in patients who underwent abdominal surgery with recent exposure to anti-tumour necrosis factor therapy. A retrospective case-control study with detailed matching was performed for subjects with IBD with and without exposure to biologics within 180 days of abdominal surgery. Postoperative outcomes were compared between the groups. 473 procedures were reviewed consisting of 195 patients with exposure to biologics and 278 matched controls. There were no significant differences in most postoperative outcomes such as: length of stay, fever (≥ 38.5°C), urinary tract infection, pneumonia, bacteraemia, readmission, reoperations and mortality. On univariate analysis, procedures on biologics had more wound infections compared with controls (19% vs 11%; p=0.008), but this was not significant in multivariate analysis. Concomitant therapy with biologics and thiopurines was associated with increased frequencies of urinary tract infections (p=0.0007) and wound infections (p=0.0045). Operations performed ≤ 14 days from last biologic dose had similar rates of infections and other outcomes when compared with those performed within 15-30 days or 31-180 days. Patients with detectable preoperative infliximab levels had similar rates of wound infection compared with those with undetectable levels (3/10 vs 0/9; p=0.21). Preoperative treatment with TNF-α antagonists in patients with IBD is not associated with most early postoperative complications. A shorter time interval from last biological dose is not associated with increased postoperative complications. In most cases, surgery should not be delayed, and appropriate biological therapy may be continued perioperatively.

  18. Influence of a five-day vegetarian diet on urinary levels of antibiotics and phthalate metabolites: a pilot study with "Temple Stay" participants.

    Science.gov (United States)

    Ji, Kyunghee; Lim Kho, Young; Park, Yoonsuk; Choi, Kyungho

    2010-05-01

    Diet is purported to be means of exposure to many environmental contaminants. The purpose of this study is to understand the influence of dietary change on the levels of exposure to several environmental chemicals - in particular, antibiotics and phthalates. For this purpose, we examined the extent to which short-term changes in diet influenced the inadvertent exposure levels to these chemicals in an adult population. We recruited participants (n=25) of a five-day 'Temple Stay' program in Korea and collected urine samples before and after the program. We also conducted a questionnaire survey on participants' dietary patterns prior to their participation. During the program, participants followed the daily routines of Buddhist monks and maintained a vegetarian diet. Urinary levels of three antibiotics and their major metabolites, metabolites of four major phthalates, and malondialdehyde (MDA) as an oxidative stress biomarker were analyzed. The frequency and levels of detection for antibiotics and phthalates noticeably decreased during the program. Urinary MDA levels were significantly lower than before program participation (0.16 versus 0.27mg/g creatinine). Although the exposure to target compounds might be influenced by other behavioral patterns, these results suggest that even short-term changes in dietary behavior may significantly decrease inadvertent exposure to antibiotics and phthalates and hence may reduce oxidative stress levels. Copyright 2010 Elsevier Inc. All rights reserved.

  19. Airborne exposures associated with the typical use of an aerosol brake cleaner during vehicle repair work.

    Science.gov (United States)

    Fries, Michael; Williams, Pamela R D; Ovesen, Jerald; Maier, Andrew

    2018-04-19

    Many petroleum-based products are used for degreasing and cleaning purposes during vehicle maintenance and repairs. Although prior studies have evaluated chemical exposures associated with this type of work, most of these have focused on gasoline and exhaust emissions, with few samples collected solely during the use of an aerosol cleaning product. In this case study, we assess the type of airborne exposures that would be expected from the typical use of an aerosol brake cleaner during vehicle repair work. Eight exposure scenarios were evaluated over a two-day study in which the benzene content of the brake cleaner and potential for dilution ventilation and air flow varied. Both short-term (15 min) and task-based (≥1 hr) charcoal tube samples were collected in the breathing zone and adjacent work area and analyzed for total hydrocarbons (THCs), toluene, and benzene. The majority of personal (N = 48) and area (N = 47) samples had detectable levels of THC and toluene, but no detections of benzene were found. For the personal short-term samples, average airborne concentrations ranged from 3.1 - 61.5 ppm (13.8-217.5 mg/m 3 ) for THC and 2.2 - 44.0 ppm (8.2-162.5 mg/m 3 ) for toluene, depending on the scenario. Compared to the personal short-term samples, average concentrations were generally 2 to 3 times lower for the personal task-based samples and 2 to 5 times lower for the area short-term samples. The highest exposures occurred when the garage bay doors were closed, floor fan was turned off, or greatest amount of brake cleaner was used. These findings add to the limited dataset on this topic and can be used to bound or approximate worker or consumer exposures from use of aerosol cleaning products with similar compositions and use patterns.

  20. Short sleep duration and poor sleep quality predict next-day suicidal ideation: an ecological momentary assessment study.

    Science.gov (United States)

    Littlewood, Donna L; Kyle, Simon D; Carter, Lesley-Anne; Peters, Sarah; Pratt, Daniel; Gooding, Patricia

    2018-04-26

    Sleep problems are a modifiable risk factor for suicidal thoughts and behaviors. Yet, sparse research has examined temporal relationships between sleep disturbance, suicidal ideation, and psychological factors implicated in suicide, such as entrapment. This is the first in-the-moment investigation of relationships between suicidal ideation, objective and subjective sleep parameters, and perceptions of entrapment. Fifty-one participants with current suicidal ideation completed week-long ecological momentary assessments. An actigraph watch was worn for the duration of the study, which monitored total sleep time, sleep efficiency, and sleep latency. Daily sleep diaries captured subjective ratings of the same sleep parameters, with the addition of sleep quality. Suicidal ideation and entrapment were measured at six quasi-random time points each day. Multi-level random intercept models and moderation analyses were conducted to examine the links between sleep, entrapment, and suicidal ideation, adjusting for anxiety and depression severity. Analyses revealed a unidirectional relationship whereby short sleep duration (both objective and subjective measures), and poor sleep quality, predicted the higher severity of next-day suicidal ideation. However, there was no significant association between daytime suicidal ideation and sleep the following night. Sleep quality moderated the relationship between pre-sleep entrapment and awakening levels of suicidal ideation. This is the first study to report night-to-day relationships between sleep disturbance, suicidal ideation, and entrapment. Findings suggest that sleep quality may alter the strength of the relationship between pre-sleep entrapment and awakening suicidal ideation. Clinically, results underscore the importance of assessing and treating sleep disturbance when working with those experiencing suicidal ideation.

  1. Short-term exposure to mobile phone base station signals does not affect cognitive functioning or physiological measures in individuals who report sensitivity to electromagnetic fields and controls.

    Science.gov (United States)

    Eltiti, Stacy; Wallace, Denise; Ridgewell, Anna; Zougkou, Konstantina; Russo, Riccardo; Sepulveda, Francisco; Fox, Elaine

    2009-10-01

    Individuals who report sensitivity to electromagnetic fields often report cognitive impairments that they believe are due to exposure to mobile phone technology. Previous research in this area has revealed mixed results, however, with the majority of research only testing control individuals. Two studies using control and self-reported sensitive participants found inconsistent effects of mobile phone base stations on cognitive functioning. The aim of the present study was to clarify whether short-term (50 min) exposure at 10 mW/m(2) to typical Global System for Mobile Communication (GSM) and Universal Mobile Telecommunications System (UMTS) base station signals affects attention, memory, and physiological endpoints in sensitive and control participants. Data from 44 sensitive and 44 matched-control participants who performed the digit symbol substitution task (DSST), digit span task (DS), and a mental arithmetic task (MA), while being exposed to GSM, UMTS, and sham signals under double-blind conditions were analyzed. Overall, cognitive functioning was not affected by short-term exposure to either GSM or UMTS signals in the current study. Nor did exposure affect the physiological measurements of blood volume pulse (BVP), heart rate (HR), and skin conductance (SC) that were taken while participants performed the cognitive tasks.

  2. Personal endotoxin exposure in a panel study of school children with asthma

    Directory of Open Access Journals (Sweden)

    Tjoa Thomas

    2011-08-01

    Full Text Available Abstract Background Endotoxin exposure has been associated with asthma exacerbations and increased asthma prevalence. However, there is little data regarding personal exposure to endotoxin in children at risk, or the relation of personal endotoxin exposure to residential or ambient airborne endotoxin. The relation between personal endotoxin and personal air pollution exposures is also unknown. Methods We characterized personal endotoxin exposures in 45 school children with asthma ages 9-18 years using 376 repeated measurements from a PM2.5 active personal exposure monitor. We also assayed endotoxin in PM2.5 samples collected from ambient regional sites (N = 97 days and from a subset of 12 indoor and outdoor subject home sites (N = 109 and 111 days, respectively in Riverside and Whittier, California. Endotoxin was measured using the Limulus Amoebocyte Lysate kinetic chromogenic assay. At the same time, we measured personal, home and ambient exposure to PM2.5 mass, elemental carbon (EC, and organic carbon (OC. To assess exposure relations we used both rank correlations and mixed linear regression models, adjusted for personal temperature and relative humidity. Results We found small positive correlations of personal endotoxin with personal PM2.5 EC and OC, but not personal PM2.5 mass or stationary site air pollutant measurements. Outdoor home, indoor home and ambient endotoxin were moderately to strongly correlated with each other. However, in mixed models, personal endotoxin was not associated with indoor home or outdoor home endotoxin, but was associated with ambient endotoxin. Dog and cat ownership were significantly associated with increased personal but not indoor endotoxin. Conclusions Daily fixed site measurements of endotoxin in the home environment may not predict daily personal exposure, although a larger sample size may be needed to assess this. This conclusion is relevant to short-term exposures involved in the acute exacerbation of

  3. Short-term use of glucocorticoids and risk of peptic ulcer bleeding: a nationwide population-based case-crossover study.

    Science.gov (United States)

    Tseng, C-L; Chen, Y-T; Huang, C-J; Luo, J-C; Peng, Y-L; Huang, D-F; Hou, M-C; Lin, H-C; Lee, F-Y

    2015-09-01

    Controversy exists regarding glucocorticoids therapy and the risk of peptic ulcer bleeding (PUB). The present study was undertaken to determine whether short-term use of glucocorticoids is associated with the occurrence of peptic ulcer bleeding. The records of adult patients hospitalised for newly diagnosed peptic ulcer bleeding from 2000 to 2012 were retrieved from the Taiwan National Health Insurance Research Database, a nationwide population-based registry system. The association between systemic glucocorticoids usage and peptic ulcer bleeding was determined with a conditional logistic regression model comparing cases and controls during time windows of 7, 14 and 28 days using a case-crossover design. Of the 8894 enrolled patients, the adjusted self-matched odds ratios for peptic ulcer bleeding after exposure to the glucocorticoids were 1.37 (95% CI: 1.12-1.68, P = 0.003) for the 7-day window, 1.66 (95% CI: 1.38-2.00, P peptic ulcer bleeding. Concomitant use of a nonselective nonsteroidal anti-inflammatory drug (NSAID) or aspirin further elevated the risk. However, it does not eliminate the effect of underlying diseases flare-up that may have placed the patients at risk for peptic ulcer bleeding in this kind of study design. Short-term (7-28 days) exposure to glucocorticoids is significantly associated with peptic ulcer bleeding; this risk seems dose-dependent and is higher when nonselective NSAIDs or aspirin are used concurrently. © 2015 John Wiley & Sons Ltd.

  4. Effect of short-term subaerial exposure on the cauliflower coral, Pocillopora damicornis, during a simulated extreme low-tide event

    KAUST Repository

    Castrillón-Cifuentes, Ana Lucia

    2017-02-06

    There is increased interest in understanding how stress reduces coral resistance to disturbances and how acclimatization increases the ability of corals to resist future stress. Most extreme low tides at Gorgona Island, which expose reef flats to air, do not appear to negatively affect corals because corals usually do not undergo lethal bleaching during such events. However, coral physiology and fitness may be impacted by this phenomenon. The aim of this study was to evaluate whether corals exposed to air have modified biological functions to resist bleaching. To test this, an extreme low-tide event was simulated in the field. Colonies of Pocillopora damicornis were exposed to air for 15 or 40 min over the course of one, two, or three consecutive days. This procedure was repeated for one to three months. Colonies of P. damicornis exposed to air had reduced fecundity, decreased zooxanthellae density, and changed color from darker to lighter. However, the growth rate of exposed corals was similar to that of non-exposed colonies. We conclude that short periods of subaerial exposure during extreme low tides are not lethal to P. damicornis, but negatively affect sexual reproduction, which might have deleterious effects at the population level. The periodic occurrence of extreme low tides in the tropical eastern Pacific may be one factor responsible for the high rate of asexual reproduction (e.g., fragmentation) in pocilloporid corals of this region.

  5. Effect of short-term subaerial exposure on the cauliflower coral, Pocillopora damicornis, during a simulated extreme low-tide event

    KAUST Repository

    Castrilló n-Cifuentes, Ana Lucia; Lozano-Corté s, Diego; Zapata, Fernando A.

    2017-01-01

    There is increased interest in understanding how stress reduces coral resistance to disturbances and how acclimatization increases the ability of corals to resist future stress. Most extreme low tides at Gorgona Island, which expose reef flats to air, do not appear to negatively affect corals because corals usually do not undergo lethal bleaching during such events. However, coral physiology and fitness may be impacted by this phenomenon. The aim of this study was to evaluate whether corals exposed to air have modified biological functions to resist bleaching. To test this, an extreme low-tide event was simulated in the field. Colonies of Pocillopora damicornis were exposed to air for 15 or 40 min over the course of one, two, or three consecutive days. This procedure was repeated for one to three months. Colonies of P. damicornis exposed to air had reduced fecundity, decreased zooxanthellae density, and changed color from darker to lighter. However, the growth rate of exposed corals was similar to that of non-exposed colonies. We conclude that short periods of subaerial exposure during extreme low tides are not lethal to P. damicornis, but negatively affect sexual reproduction, which might have deleterious effects at the population level. The periodic occurrence of extreme low tides in the tropical eastern Pacific may be one factor responsible for the high rate of asexual reproduction (e.g., fragmentation) in pocilloporid corals of this region.

  6. Effect of short-term subaerial exposure on the cauliflower coral, Pocillopora damicornis, during a simulated extreme low-tide event

    Science.gov (United States)

    Castrillón-Cifuentes, Ana Lucia; Lozano-Cortés, Diego F.; Zapata, Fernando A.

    2017-06-01

    There is increased interest in understanding how stress reduces coral resistance to disturbances and how acclimatization increases the ability of corals to resist future stress. Most extreme low tides at Gorgona Island, which expose reef flats to air, do not appear to negatively affect corals because corals usually do not undergo lethal bleaching during such events. However, coral physiology and fitness may be impacted by this phenomenon. The aim of this study was to evaluate whether corals exposed to air have modified biological functions to resist bleaching. To test this, an extreme low-tide event was simulated in the field. Colonies of Pocillopora damicornis were exposed to air for 15 or 40 min over the course of one, two, or three consecutive days. This procedure was repeated for one to three months. Colonies of P. damicornis exposed to air had reduced fecundity, decreased zooxanthellae density, and changed color from darker to lighter. However, the growth rate of exposed corals was similar to that of non-exposed colonies. We conclude that short periods of subaerial exposure during extreme low tides are not lethal to P. damicornis, but negatively affect sexual reproduction, which might have deleterious effects at the population level. The periodic occurrence of extreme low tides in the tropical eastern Pacific may be one factor responsible for the high rate of asexual reproduction (e.g., fragmentation) in pocilloporid corals of this region.

  7. Health effect from EMF exposure of Korea population

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. S.; Cho, Y. S.; Lee, J. T.; Yup, M. J.; Hong, J. H. [Institute of Environmental and Industrrial Medicine, Hanyang Univ., Seoul (Korea, Republic of)

    2002-07-01

    This study on health effect from EMF exposure was performed from June 2001 to April 2002 to compare changes in melatonin levels in urine of 40 subjects during their normal sleeping hours, to evaluate heart rate, ST segment in ventricular, and ventricular premature beat for cardiac function, to evaluate microwave exposure from cellular phones which may have a potential influence on the electro physiologic function of human brain, and each 20 subjects in occupational and non-occupational group measured personal 24-h continual exposure, using EMDEX(for 40-800Hz, Enertech Consultant, Inc.). An urine samples for analysis of melatonin excretion level were collected 1 times a day(immediately after wake-up) for five days from each subjects and analyzed by radioimmunoassay, HRV-test for relationship between heart rate and EMF exposure was performed heart rate beat using Holter for subjects, and double EEG-test were performed in 10 long-term users of the cellularphones when using and not using them, and a single EEG-test in 10 short-term users of the cellular phones. Each EEG-recording took 40 min consisting of 30 min filed exposure and 10 min measurement. And We estimated the economic value of the potential damage of electromagnetic radiation from cellular phone, and the willingness to pay of people for the study of the radiation damage led by the government, by applying contingent variation method. The results of this study were followed; 1. Personal exposure assessment 2. We showed not significant difference for the subjective average melatonin levels between occupational and non- occupational groups exposed to electromagnetic fields. 3. We showed no difference in the awake EEGs in terms of spectral power density measures between long-term users and short-term users of cellular phones. 4. We found that the economic value of the potential damage by the radiation for a typical cellular phone user is about 20,000 won per year and he would be willing to pay about 1,800 won

  8. Association of short-term exposure to ground-level ozone and respiratory outpatient clinic visits in a rural location – Sublette County, Wyoming, 2008–2011

    Energy Technology Data Exchange (ETDEWEB)

    Pride, Kerry R., E-mail: hgp3@cdc.gov [Epidemic Intelligence Service, Centers for Disease Control and Prevention, Atlanta, GA (United States); Wyoming Department of Health, 6101 Yellowstone Road, Suite 510, Cheyenne, WY 82002 (United States); Peel, Jennifer L. [Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523 (United States); Robinson, Byron F. [Scientific Education and Professional Development Program Office, Office of Surveillance, Epidemiology and Laboratory Services, Centers for Disease Control and Prevention, 1600 Clifton Rd, NE, E-92, Atlanta, GA 30333 (United States); Busacker, Ashley [Field Support Branch, Division of Reproductive Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Wyoming Department of Health, 6101 Yellowstone Road, Suite 510, Cheyenne, WY 82002 (United States); Grandpre, Joseph [Chronic Disease Epidemiologist, Wyoming Department of Health, 6101 Yellowstone Road, Suite 510, Cheyenne, WY 82002 (United States); Bisgard, Kristine M. [Scientific Education and Professional Development Program Office, Office of Surveillance, Epidemiology and Laboratory Services, Centers for Disease Control and Prevention, 600 Clifton Road, NE, E-92, Atlanta, GA 30333 (United States); Yip, Fuyuen Y. [Air Pollution and Respiratory Disease Branch, Centers for Disease Control and Prevention, 600 Clifton Rd, NE, E-92, Atlanta, GA 30333 (United States); Murphy, Tracy D. [Wyoming Department of Health, 101 Yellowstone Road, Suite 510, Cheyenne, WY 82002 (United States)

    2015-02-15

    Objective: Short-term exposure to ground-level ozone has been linked to adverse respiratory and other health effects; previous studies typically have focused on summer ground-level ozone in urban areas. During 2008–2011, Sublette County, Wyoming (population: ~10,000 persons), experienced periods of elevated ground-level ozone concentrations during the winter. This study sought to evaluate the association of daily ground-level ozone concentrations and health clinic visits for respiratory disease in this rural county. Methods: Clinic visits for respiratory disease were ascertained from electronic billing records of the two clinics in Sublette County for January 1, 2008–December 31, 2011. A time-stratified case-crossover design, adjusted for temperature and humidity, was used to investigate associations between ground-level ozone concentrations measured at one station and clinic visits for a respiratory health concern by using an unconstrained distributed lag of 0–3 days and single-day lags of 0 day, 1 day, 2 days, and 3 days. Results: The data set included 12,742 case-days and 43,285 selected control-days. The mean ground-level ozone observed was 47±8 ppb. The unconstrained distributed lag of 0–3 days was consistent with a null association (adjusted odds ratio [aOR]: 1.001; 95% confidence interval [CI]: 0.990–1.012); results for lags 0, 2, and 3 days were consistent with the null. However, the results for lag 1 were indicative of a positive association; for every 10-ppb increase in the 8-h maximum average ground-level ozone, a 3.0% increase in respiratory clinic visits the following day was observed (aOR: 1.031; 95% CI: 0.994–1.069). Season modified the adverse respiratory effects: ground-level ozone was significantly associated with respiratory clinic visits during the winter months. The patterns of results from all sensitivity analyzes were consistent with the a priori model. Conclusions: The results demonstrate an association of increasing ground

  9. Association of short-term exposure to ground-level ozone and respiratory outpatient clinic visits in a rural location – Sublette County, Wyoming, 2008–2011

    International Nuclear Information System (INIS)

    Pride, Kerry R.; Peel, Jennifer L.; Robinson, Byron F.; Busacker, Ashley; Grandpre, Joseph; Bisgard, Kristine M.; Yip, Fuyuen Y.; Murphy, Tracy D.

    2015-01-01

    Objective: Short-term exposure to ground-level ozone has been linked to adverse respiratory and other health effects; previous studies typically have focused on summer ground-level ozone in urban areas. During 2008–2011, Sublette County, Wyoming (population: ~10,000 persons), experienced periods of elevated ground-level ozone concentrations during the winter. This study sought to evaluate the association of daily ground-level ozone concentrations and health clinic visits for respiratory disease in this rural county. Methods: Clinic visits for respiratory disease were ascertained from electronic billing records of the two clinics in Sublette County for January 1, 2008–December 31, 2011. A time-stratified case-crossover design, adjusted for temperature and humidity, was used to investigate associations between ground-level ozone concentrations measured at one station and clinic visits for a respiratory health concern by using an unconstrained distributed lag of 0–3 days and single-day lags of 0 day, 1 day, 2 days, and 3 days. Results: The data set included 12,742 case-days and 43,285 selected control-days. The mean ground-level ozone observed was 47±8 ppb. The unconstrained distributed lag of 0–3 days was consistent with a null association (adjusted odds ratio [aOR]: 1.001; 95% confidence interval [CI]: 0.990–1.012); results for lags 0, 2, and 3 days were consistent with the null. However, the results for lag 1 were indicative of a positive association; for every 10-ppb increase in the 8-h maximum average ground-level ozone, a 3.0% increase in respiratory clinic visits the following day was observed (aOR: 1.031; 95% CI: 0.994–1.069). Season modified the adverse respiratory effects: ground-level ozone was significantly associated with respiratory clinic visits during the winter months. The patterns of results from all sensitivity analyzes were consistent with the a priori model. Conclusions: The results demonstrate an association of increasing ground

  10. Exposure levels and determinants of inhalable dust exposure in bakeries.

    Science.gov (United States)

    Burstyn, I; Teschke, K; Kennedy, S M

    1997-12-01

    The study's objectives were to measure full-shift exposure to inhalable dust in bakeries and define the determinants of full-shift exposure. Inhalable dust was measured gravimetrically. Ninety-six bakery workers, employed in seven different bakeries, participated in the study. Two side-by-side full-shift inhalable dust samples were obtained from each study participant on a single occasion. Samples were collected on 18 days selected at random. During the entire sampling period, bakers were observed and information on 14 different tasks was recorded at 15 min intervals. Other production characteristics were also recorded for each sampling day. These task and production variables were used in statistical modelling to identify significant predictors of exposure. The mean full-shift inhalable dust exposure was 8.2 mg/m3 (range: 0.1-110 mg/m3). A regression model explained 79% of the variability in exposure. The model indicated that tasks such as weighing, pouring and operating dough-brakers and reversible sheeters increased the exposure, while packing, catching and decorating decreased the exposure. Bread and bun production lines were associated with increased full-shift inhalable dust exposure, while cake production and substitution of dusting with the use of divider oil were associated with decreased exposure. Production tasks and characteristics are strong predictors of personal full-shift exposures to flour dust among bakers; these can be altered to reduce exposure levels.

  11. High-dimensional covariance forecasting for short intra-day horizons

    NARCIS (Netherlands)

    Oomen, R.C.A.

    2010-01-01

    Asset return covariances at intra-day horizons are known to tend towards zero due to market microstructure effects. Thus, traders who simply scale their daily covariance forecast to match their trading horizon are likely to over-estimate the actual experienced asset dependence. In this paper, some

  12. Esophageal manometry findings and degree of acid exposure in short and long Barrett's esophagus

    Directory of Open Access Journals (Sweden)

    Laura Helman

    2012-03-01

    Full Text Available CONTEXT: Barrett's esophagus (BE is characterized by intestinal metaplasia in the distal esophagus and is classified as short-segment (3 cm - LSSBE. It is suggested that LSSBE is associated with more severe esophageal motor abnormalities and increased acid exposure time than SSBE. OBJECTIVE: To evaluate the prevalence of esophageal manometriy abnormalities and acid exposure times in patients with SSBE and LSSBE. METHODS: Barrett's esophagus patients identified by upper endoscopy and confirmed by histopathology were, retrospectively, reviewed and divided into two groups: SSBE and LSBE. Demographic data, symptom duration, prevalence of hiatal hernia, lower esophagus sphincter basal pressure, prevalence of esophageal body abnormalities and acid exposure times were evaluated. RESULTS: Forty-six patients with SSBE (24 males - 52.2%, mean age of 55.2 years and 28 patients with LSBE (18 males - 64.3%, mean age of 50.5 years. Mean symptom duration was 9.9 years for SSBE and 12.9 years for LSSBE. Hiatal hernia was present in 84.2% of SSBE, 96.3% of LSBE; average lower esophagus sphincter pressure in SSBE 9.15 mm Hg, in LSBE 6.99 mm Hg; lower esophagus sphincter hypotension in SSBE was 65.9%, in LSSBE 82.1%; aperistalsis in SSBE 6.5%, LSSBE 3.6%; mild/moderate ineffective esophageal motility in SSBE 34.8%, LSBE 46.4%; severe moderate ineffective esophageal motility in SSBE 10.9%, LSBE 7,1%; nutcracker esophagus/segmental nutcracker esophagus in SSBE 8.6%, LSBE 0%; normal body in SSBE 39.1%, in LSBE 42.9%, no statistical difference for any of these values (P<0.05. Average % total time pH<4 in SSBE 9.12, LSBE 17.27 (P<0.000; % time pH<4 upright in SSBE 11.91; LSBE 24.29 (P=0.003; % time pH<4 supine in SSBE 10.86, LSBE 33.26 (P = 0.000. CONCLUSION: There was no difference between the prevalence of motor disorders in patients with SSBE and LSSBE. Acid reflux in upright and supine positions was more intense in LSBE.

  13. Pollen exposure and hospitalization due to asthma exacerbations: daily time series in a European city

    Science.gov (United States)

    Osborne, Nicholas J.; Alcock, Ian; Wheeler, Benedict W.; Hajat, Shakoor; Sarran, Christophe; Clewlow, Yolanda; McInnes, Rachel N.; Hemming, Deborah; White, Mathew; Vardoulakis, Sotiris; Fleming, Lora E.

    2017-10-01

    Exposure to pollen can contribute to increased hospital admissions for asthma exacerbation. This study applied an ecological time series analysis to examine associations between atmospheric concentrations of different pollen types and the risk of hospitalization for asthma in London from 2005 to 2011. The analysis examined short-term associations between daily pollen counts and hospital admissions in the presence of seasonal and long-term patterns, and allowed for time lags between exposure and admission. Models were adjusted for temperature, precipitation, humidity, day of week, and air pollutants. Analyses revealed an association between daily counts (continuous) of grass pollen and adult hospital admissions for asthma in London, with a 4-5-day lag. When grass pollen concentrations were categorized into Met Office pollen `alert' levels, `very high' days (vs. `low') were associated with increased admissions 2-5 days later, peaking at an incidence rate ratio of 1.46 (95%, CI 1.20-1.78) at 3 days. Increased admissions were also associated with `high' versus `low' pollen days at a 3-day lag. Results from tree pollen models were inconclusive and likely to have been affected by the shorter pollen seasons and consequent limited number of observation days with higher tree pollen concentrations. Future reductions in asthma hospitalizations may be achieved by better understanding of environmental risks, informing improved alert systems and supporting patients to take preventive measures.

  14. Short-term chromium (VI) exposure increases phosphorus uptake by the extraradical mycelium of the arbuscular mycorrhizal fungus Rhizophagus irregularis MUCL 41833.

    Science.gov (United States)

    Gil-Cardeza, María Lourdes; Calonne-Salmon, Maryline; Gómez, Elena; Declerck, Stéphane

    2017-11-01

    Hexavalent chromium is a potent carcinogen, while phosphorus is an essential nutrient. The role of arbuscular mycorrhizal fungi (AMF) in the uptake of P is well known and was also reported, at low levels, for Cr. However, it is unclear whether the uptake of Cr can impact the short-term uptake dynamics of P since both elements have a similar chemical structure and may thus potentially compete with each other during the uptake process. This study investigated the impact of Cr(VI) on short-term P uptake by the AMF Rhizophagus irregularis MUCL 41833 in Medicago truncatula. Bi-compartmented Petri plates were used to spatially separate a root compartment (RC) from a hyphal compartment (HC) using a whole plant in vitro culture system. The HC was supplemented with Cr(VI). Chromium(VI) as well as total Cr and P were monitored during 16 h within the HC and their concentrations determined by the end of the experiment within roots and shoots. Our results indicated that the uptake and translocation of Cr from hyphae to roots was a fast process: roots in which the extraradical mycelium (ERM) was exposed to Cr(VI) accumulated more Cr than roots of which the ERM was not exposed to Cr(VI) or was dead. Our results further confirmed that dead ERM immobilized more Cr than alive ERM. Finally our results demonstrated that the short exposure to Cr(VI) was sufficient to stimulate P uptake by the ERM and that the stimulation process began within the first 4 h of exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Perinatal bisphenol A exposure and adult glucose homeostasis: identifying critical windows of exposure.

    Directory of Open Access Journals (Sweden)

    Jingli Liu

    Full Text Available Bisphenol A (BPA is a widespread endocrine-disrupting chemical used as the building block for polycarbonate plastics. Epidemiological evidence has correlated BPA exposure with higher risk of heart disease and type 2 diabetes. However, it remains unknown whether there are critical windows of susceptibility to BPA exposure on the development of dysglycemia. This study was an attempt to investigate the critical windows and the long-term consequences of perinatal exposure to BPA on glucose homeostasis. Pregnant mice were given either vehicle or BPA (100 µg/kg/day at different time of perinatal stage: 1 on days 1-6 of pregnancy (P1-P6, preimplantation exposure; 2 from day 6 of pregnancy until postnatal day (PND 0 (P6-PND0, fetal exposure; 3 from lactation until weaning (PND0-PND21, neonatal exposure; and 4 from day 6 of gestation until weaning (P6-PND21, fetal and neonatal exposure. At 3, 6 and 8 months of age, offspring in each group were challenged with glucose and insulin tolerance tests. Then islet morphometry and β-cell function were measured. The glucose homeostasis was impaired in P6-PND0 mice from 3 to 6 months of age, and this continued to 8 months in males, but not females. While in PND0-PND21 and P6-PND21 BPA-treated groups, only the 3-month-old male offspring developed glucose intolerance. Moreover, at the age of 3 months, perinatal exposure to BPA resulted in the increase of β-cell mass mainly due to the coordinate changes in cell replication, neogenesis, and apoptosis. The alterations of insulin secretion and insulin sensitivity, rather than β-cell mass, were consistent with the development of glucose intolerance. Our findings suggest that BPA may contribute to metabolic disorders relevant to glucose homeostasis and the effects of BPA were dose, sex, and time-dependent. Fetal development stage may be the critical window of susceptibility to BPA exposure.

  16. Extreme Precipitation and Flooding: Exposure Characterization and the Association Between Exposure and Mortality in 108 United States Communities, 1987-2005

    Science.gov (United States)

    Severson, R. L.; Peng, R. D.; Anderson, G. B.

    2017-12-01

    There is substantial evidence that extreme precipitation and flooding are serious threats to public health and safety. These threats are predicted to increase with climate change. Epidemiological studies investigating the health effects of these events vary in the methods used to characterize exposure. Here, we compare two sources of precipitation data (National Oceanic and Atmospheric Administration (NOAA) station-based and North American Land Data Assimilation Systems (NLDAS-2) Reanalysis data-based) for estimating exposure to extreme precipitation and two sources of flooding data, based on United States Geological Survey (USGS) streamflow gages and the NOAA Storm Events database. We investigate associations between each of the four exposure metrics and short-term risk of four causes of mortality (accidental, respiratory-related, cardiovascular-related, and all-cause) in the United States from 1987 through 2005. Average daily precipitation values from the two precipitation data sources were moderately correlated (Spearman's rho = 0.74); however, values from the two data sources were less correlated when comparing binary metrics of exposure to extreme precipitation days (Jaccard index (J) = 0.35). Binary metrics of daily flood exposure were poorly correlated between the two flood data sources (Spearman's rho = 0.07; J = 0.05). There was little correlation between extreme precipitation exposure and flood exposure in study communities. We did not observe evidence of a positive association between any of the four exposure metrics and risk of any of the four mortality outcomes considered. Our results suggest, due to the observed lack of agreement between different extreme precipitation and flood metrics, that exposure to extreme precipitation may not serve as an effective surrogate for exposures related to flooding. Furthermore, It is possible that extreme precipitation and flood exposures may often be too localized to allow accurate exposure assessment at the

  17. Magnetospheric Truncation, Tidal Inspiral, and the Creation of Short-period and Ultra-short-period Planets

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eve J.; Chiang, Eugene, E-mail: evelee@berkeley.edu [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)

    2017-06-10

    Sub-Neptunes around FGKM dwarfs are evenly distributed in log orbital period down to ∼10 days, but dwindle in number at shorter periods. Both the break at ∼10 days and the slope of the occurrence rate down to ∼1 day can be attributed to the truncation of protoplanetary disks by their host star magnetospheres at corotation. We demonstrate this by deriving planet occurrence rate profiles from empirical distributions of pre-main-sequence stellar rotation periods. Observed profiles are better reproduced when planets are distributed randomly in disks—as might be expected if planets formed in situ—rather than piled up near disk edges, as would be the case if they migrated in by disk torques. Planets can be brought from disk edges to ultra-short (<1 day) periods by asynchronous equilibrium tides raised on their stars. Tidal migration can account for how ultra-short-period planets are more widely spaced than their longer-period counterparts. Our picture provides a starting point for understanding why the sub-Neptune population drops at ∼10 days regardless of whether the host star is of type FGK or early M. We predict planet occurrence rates around A stars to also break at short periods, but at ∼1 day instead of ∼10 days because A stars rotate faster than stars with lower masses (this prediction presumes that the planetesimal building blocks of planets can drift inside the dust sublimation radius).

  18. Magnetospheric Truncation, Tidal Inspiral, and the Creation of Short-period and Ultra-short-period Planets

    International Nuclear Information System (INIS)

    Lee, Eve J.; Chiang, Eugene

    2017-01-01

    Sub-Neptunes around FGKM dwarfs are evenly distributed in log orbital period down to ∼10 days, but dwindle in number at shorter periods. Both the break at ∼10 days and the slope of the occurrence rate down to ∼1 day can be attributed to the truncation of protoplanetary disks by their host star magnetospheres at corotation. We demonstrate this by deriving planet occurrence rate profiles from empirical distributions of pre-main-sequence stellar rotation periods. Observed profiles are better reproduced when planets are distributed randomly in disks—as might be expected if planets formed in situ—rather than piled up near disk edges, as would be the case if they migrated in by disk torques. Planets can be brought from disk edges to ultra-short (<1 day) periods by asynchronous equilibrium tides raised on their stars. Tidal migration can account for how ultra-short-period planets are more widely spaced than their longer-period counterparts. Our picture provides a starting point for understanding why the sub-Neptune population drops at ∼10 days regardless of whether the host star is of type FGK or early M. We predict planet occurrence rates around A stars to also break at short periods, but at ∼1 day instead of ∼10 days because A stars rotate faster than stars with lower masses (this prediction presumes that the planetesimal building blocks of planets can drift inside the dust sublimation radius).

  19. Effects of Copper Exposure on Photosynthesis and Growth of the Seagrass Cymodocea nodosa: An Experimental Assessment.

    Science.gov (United States)

    Llagostera, Izaskun; Cervantes, Daniel; Sanmartí, Neus; Romero, Javier; Pérez, Marta

    2016-09-01

    Seagrasses form some of the most important coastal habitats. They may be negatively affected by trace metal contamination in certain coastal areas. In this study we experimentally assessed selected morphological and physiological traits of the seagrass Cymodocea nodosa, with increasing concentrations of copper (Cu) under controlled laboratory conditions. Short term (21 days) sub-lethal effects such as decreased maximum quantum yield, increased leaf necrosis and decreased shoot growth and shoot recruitment were clearly observed at the highest Cu exposure (5 mg L(-1)), while the effects were weaker at the intermediate concentration (2.5 mg L(-1)) and almost absent at the lowest concentration (1 mg L(-1)), indicating that this species is highly tolerant to copper exposure, at least in the short term. This fact could help to explain its distribution in relatively polluted coastal waters.

  20. Isotopic Evidence for Multi-stage Cosmic-ray Exposure Histories of Lunar Meteorites: Long Residence on the Moon and Short Transition to the Earth

    International Nuclear Information System (INIS)

    Hidaka, Hiroshi; Sakuma, Keisuke; Nishiizumi, Kunihiko; Yoneda, Shigekazu

    2017-01-01

    It is known that most lunar meteorites have complicated cosmic-ray exposure experiences on the Moon and in space. In this study, cosmic-ray irradiation histories of six lunar meteorites, Dhofar 489, Northwest Africa 032 (NWA 032), NWA 479, NWA 482, NWA 2995, and NWA 5000, were characterized from neutron-captured isotopic shifts of Sm and Gd, and from the abundances of long-lived cosmogenic radionuclides like 10 Be, 26 Al, 36 Cl, and 41 Ca. Sm and Gd isotopic data of all of six meteorites show significant isotopic shifts of 149 Sm– 150 Sm and 157 Gd– 158 Gd caused by accumulation of neutron capture reactions due to cosmic-ray irradiation, corresponding to the neutron fluences of (1.3–9.6) × 10 16 n cm −2 . In particular, very large Sm and Gd isotopic shifts of NWA 482 are over those of a lunar regolith 70002, having the largest isotopic shifts among the Apollo regolith samples, corresponding to cosmic-ray exposure duration over 800 million years in the lunar surface (2 π irradiation). Meanwhile, the concentrations of cosmogenic radionuclides for individual six meteorites show the short irradiation time less than one million years as their bodies in space (4 π irradiation). Our data also support the results of previous studies, revealing that most of lunar meteorites have long exposure ages at shallow depths on the Moon and short transit times from the Moon to the Earth.

  1. The effects of short term and chronic exposure to tritiated drinking water on pre- and postnatal brain development

    International Nuclear Information System (INIS)

    Marthens, E. van; Zamenhof, S.

    1982-01-01

    Ingestion of HTO during oocyte maturation and continued during pre-implantation time was found to depress decidual response. At birth these offspring also showed a decrease in brain cell number. When HTO was given during pregnancy only, the offspring at birth showed a similar deficit in brain cell number. Even so, we could not demonstrate a gross deficit in oocyte maturation when HTO was ingested during sexual maturity only; however, when further continued during pregnancy, the measured newborn parameters were most severely affected. In this group, cell-multiplication in the cerebrum was severely decreased, protein synthesis was decreased, and somatic growth was also highly significantly decreased. These experiments indicate that even a short-term exposure to HTO during early pregnancy (pre-implantation) alters normal development to such an extent that it is still observable at birth. During embryonic development, HTO affected the rate of actual cell division and it is apparent that the central nervous system is most vulnerable. If the exposure to HTO is prolonged, the somatic development is also severely affected. (orig./MG)

  2. Radiation exposure records management

    International Nuclear Information System (INIS)

    Boiter, H.P.

    1975-12-01

    Management of individual radiation exposure records begins at employment with the accumulation of data pertinent to the individual and any previous occupational radiation exposure. Appropriate radiation monitorinng badges or devices are issued and accountability established. A computer master file is initiated to include the individual's name, payroll number, social security number, birth date, assigned department, and location. From this base, a radiation exposure history is accumulated to include external ionizing radiation exposure to skin and whole body, contributing neutron exposure, contributing tritium exposure, and extremity exposure. It is used also to schedule bioassay sampling and in-vivo counts and to provide other pertinent information. The file is used as a basis for providing periodic reports to management and monthly exposure summaries to departmental line supervision to assist in planning work so that individual annual exposures are kept as low as practical. Radiation exposure records management also includes documentation of radiation surveys performed by the health physicist to establish working rates and the individual estimating and recording his estimated exposure on a day-to-day basis. Exposure information is also available to contribute to Energy Research and Development Administration statistics and to the National Transuranium Registry

  3. Association between Short-Term Exposure to Air Pollution and Dyslipidemias among Type 2 Diabetic Patients in Northwest China: A Population-Based Study.

    Science.gov (United States)

    Wang, Minzhen; Zheng, Shan; Nie, Yonghong; Weng, Jun; Cheng, Ning; Hu, Xiaobin; Ren, Xiaowei; Pei, Hongbo; Bai, Yana

    2018-03-30

    Air pollution exposure may play an adverse role in diabetes. However, little data are available directly evaluating the effects of air pollution exposure in blood lipids of which dysfunction has been linked to diabetes or its complications. We aimed to evaluate the association between air pollution and lipids level among type 2 diabetic patients in Northwest China. We performed a population-based study of 3912 type 2 diabetes patients in an ongoing cohort study in China. Both spline and multiple linear regressions analysis were used to examine the association between short-term exposure to PM 10 , SO₂, NO₂ and total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). By spline analyses, we observed that the relationship between SO₂ and HDL-C and LDL-C was shown to be non-linear ( p _non-lin-association = 0.0162 and 0.000). An inverted U-shaped non-linear relationship between NO₂ and LDL-C was found ( p _non-lin-association < 0.0001). A J-shaped non-linear relationship between PM 10 and TC, HDL-C ( p _non-lin-association = 0.0173, 0.0367) was also revealed. In linear regression analyses, a 10 μg/m³ increment in SO₂ was associated with 1.31% (95% CI: 0.40-2.12%), 3.52% (95% CI: 1.07-6.03%) and 7.53% (95% CI: 5.98-9.09%) increase in TC, TG and LDL-C, respectively. A 10 μg/m³ increment in PM 10 was associated with 0.45% (95% CI: 0.08-0.82%), 0.29% (95% CI: 0.10-0.49%) and 0.83% (95% CI: 0.21-1.45%) increase in TC, HDL-C and LDL-C, respectively. For NO₂, an increment of 10 μg/m³ was statistically associated with -3.55% (95% CI: -6.40-0.61%) and 39.01% (95% CI: 31.43-47.03%) increase in HDL-C and LDL-C. The adverse effects of air pollutants on lipid levels were greater in female and elder people. Further, we found SO₂ and NO₂ played a more evident role in lipid levels in warm season, while PM 10 appeared stronger in cold season. The findings suggest that exposure to air

  4. Comparative Transcriptomes Profiling of Photoperiod-sensitive Male Sterile Rice Nongken 58S During the Male Sterility Transition between Short-day and Long-day

    Directory of Open Access Journals (Sweden)

    Zhu Yingguo

    2011-09-01

    Full Text Available Abstract Background Photoperiod-sensitive genic male sterile (PGMS rice, Nongken 58S, was discovered in 1973. It has been widely used for the production of hybrid rice, and great achievements have been made in improving rice yields. However, the mechanism of the male sterility transition in PGMS rice remains to be determined. Results To investigate the transcriptome during the male sterility transition in PGMS rice, the transcriptome of Nongken 58S under short-day (SD and long-day (LD at the glume primordium differentiation and pistil/stamen primordium forming stages was compared. Seventy-three and 128 differentially expressed genes (DEGs were identified at the glume primordium differentiation and pistil/stamen primordium forming stages, respectively. Five and 22 genes were markedly up-regulated (≥ 5-fold, and two and five genes were considerably down-regulated (≥ 5-fold under SD during the male sterility transition. Gene ontology annotation and pathway analysis revealed that four biological processes and the circadian rhythms and the flowering pathways coordinately regulated the male sterility transition. Further quantitative PCR analysis demonstrated that the circadian rhythms of OsPRR1, OsPRR37, OsGI, Hd1, OsLHY and OsDof in leaves were obviously different between Nongken 58S and Nongken 58 under LD conditions. Moreover, both OsPRR37 and Hd1 in the inflorescence displayed differences between Nongken 58S and Nongken 58 under both LD and SD conditions. Conclusion The results presented here indicate that the transcriptome in Nongken 58S was significantly suppressed under LD conditions. Among these DEGs, the circadian rhythm and the flowering pathway were involved in the male sterility transition. Furthermore, these pathways were coordinately involved in the male sterility transition in PGMS rice.

  5. Short-term degradation of air quality during major firework events in Delhi, India

    Science.gov (United States)

    Shivani; Gadi, Ranu; Saxena, Mohit; Sharma, Sudhir Kumar; Mandal, Tuhin Kumar

    2018-04-01

    The effect of firework events on air quality was assessed from ambient fine particulate matter (PM2.5) collected during the Diwali period in two consecutive years, i.e., November 2015 and October 2016. The extensive firework activities led to the short-term degradation of air quality during the Diwali days. PM2.5 samples were chemically characterised for elements, water-soluble ionic species, organic carbon (OC) and elemental carbon (EC). Ba, K, Sr, S, Mg and Na showed significant increases in concentration on Diwali days compared to pre-Diwali days which revealed their association with firecrackers. Concentration of SO4 2-, NO3 -, Cl-, K+ and NH4 + ions contributed to the increases in PM2.5 concentration on Diwali days. Higher OC/EC ratios indicated the formation of secondary organic carbon during the Diwali period. This study concludes that the high PM2.5 level during Diwali 2016 was a result of contribution from fireworks on the Diwali night, trans-regional movement of pollutants due to crop residue burning, low wind speed (0.15 m s-1), and high humidity. It was observed that short-term exposure to Diwali is plausible to generate 1.3% increase in non-carcinogenic hazard index due to elements Al and Ba during Diwali 2016, whereas no significant variation was observed for the carcinogenic risk due to Pb. However, in 2015, the increase in non-carcinogenic hazard index was appreciably lower as compared to 2016.

  6. Rat hippocampal alterations could underlie behavioral abnormalities induced by exposure to moderate noise levels.

    Science.gov (United States)

    Uran, S L; Aon-Bertolino, M L; Caceres, L G; Capani, F; Guelman, L R

    2012-08-30

    Noise exposure is known to affect auditory structures in living organisms. However, it should not be ignored that many of the effects of noise are extra-auditory. Previous findings of our laboratory demonstrated that noise was able to induce behavioral alterations that are mainly related to the cerebellum (CE) and the hippocampus (HC). Therefore, the aim of this work was to reveal new data about the vulnerability of developing rat HC to moderate noise levels through the assessment of potential histological changes and hippocampal-related behavioral alterations. Male Wistar rats were exposed to noise (95-97 dB SPL, 2h daily) either for 1 day (acute noise exposure, ANE) or between postnatal days 15 and 30 (sub-acute noise exposure, SANE). Hippocampal histological evaluation as well as short (ST) and long term (LT) habituation and recognition memory assessments were performed. Results showed a mild disruption in the different hippocampal regions after ANE and SANE schemes, along with significant behavioral abnormalities. These data suggest that exposure of developing rats to noise levels of moderate intensity is able to trigger changes in the HC, an extra-auditory structure of the Central Nervous System (CNS), that could underlie the observed behavioral effects. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Competitive short-term and long-term memory processes in spatial habituation.

    Science.gov (United States)

    Sanderson, David J; Bannerman, David M

    2011-04-01

    Exposure to a spatial location leads to habituation of exploration such that, in a novelty preference test, rodents subsequently prefer exploring a novel location to the familiar location. According to Wagner's (1981) theory of memory, short-term and long-term habituation are caused by separate and sometimes opponent processes. In the present study, this dual-process account of memory was tested. Mice received a series of exposure training trials to a location before receiving a novelty preference test. The novelty preference was greater when tested after a short, rather than a long, interval. In contrast, the novelty preference was weaker when exposure training trials were separated by a short, rather than a long interval. Furthermore, it was found that long-term habituation was determined by the independent effects of the amount of exposure training and the number of exposure training trials when factors such as the intertrial interval and the cumulative intertrial interval were controlled. A final experiment demonstrated that a long-term reduction of exploration could be caused by a negative priming effect due to associations formed during exploration. These results provide evidence against a single-process account of habituation and suggest that spatial habituation is determined by both short-term, recency-based memory and long-term, incrementally strengthened memory.

  8. Reconstructing exposures from biomarkers using exposure-pharmacokinetic modeling--A case study with carbaryl.

    Science.gov (United States)

    Brown, Kathleen; Phillips, Martin; Grulke, Christopher; Yoon, Miyoung; Young, Bruce; McDougall, Robin; Leonard, Jeremy; Lu, Jingtao; Lefew, William; Tan, Yu-Mei

    2015-12-01

    Sources of uncertainty involved in exposure reconstruction for short half-life chemicals were characterized using computational models that link external exposures to biomarkers. Using carbaryl as an example, an exposure model, the Cumulative and Aggregate Risk Evaluation System (CARES), was used to generate time-concentration profiles for 500 virtual individuals exposed to carbaryl. These exposure profiles were used as inputs into a physiologically based pharmacokinetic (PBPK) model to predict urinary biomarker concentrations. These matching dietary intake levels and biomarker concentrations were used to (1) compare three reverse dosimetry approaches based on their ability to predict the central tendency of the intake dose distribution; and (2) identify parameters necessary for a more accurate exposure reconstruction. This study illustrates the trade-offs between using non-iterative reverse dosimetry methods that are fast, less precise and iterative methods that are slow, more precise. This study also intimates the necessity of including urine flow rate and elapsed time between last dose and urine sampling as part of the biomarker sampling collection for better interpretation of urinary biomarker data of short biological half-life chemicals. Resolution of these critical data gaps can allow exposure reconstruction methods to better predict population-level intake doses from large biomonitoring studies. Published by Elsevier Inc.

  9. Formaldehyde exposure in U.S. industries from OSHA air sampling data.

    Science.gov (United States)

    Lavoue, Jerome; Vincent, Raymond; Gerin, Michel

    2008-09-01

    National occupational exposure databanks have been cited as sources of exposure data for exposure surveillance and exposure assessment for occupational epidemiology. Formaldehyde exposure data recorded in the U.S Integrated Management Information System (IMIS) between 1979 and 2001 were collected to elaborate a multi-industry retrospective picture of formaldehyde exposures and to identify exposure determinants. Due to the database design, only detected personal measurement results (n = 5228) were analyzed with linear mixed-effect models, which explained 29% of the total variance. Short-term measurement results were higher than time-weighted average (TWA) data and decreased 18% per year until 1987 (TWA data 5% per year) and 5% per year (TWA data 4% per year) after that. Exposure varied across industries with maximal estimated TWA geometric means (GM) for 2001 in the reconstituted wood products, structural wood members, and wood dimension and flooring industries (GM = 0.20 mg/m(3). Highest short-term GMs estimated for 2001 were in the funeral service and crematory and reconstituted wood products industries (GM = 0.35 mg/m(3). Exposure levels in IMIS were marginally higher during nonprogrammed inspections compared with programmed inspections. An increasing exterior temperature tended to cause a decrease in exposure levels for cold temperatures (-5% per 5 degrees C for T 15 degrees C). Concentrations measured during the same inspection were correlated and varied differently across industries and sample type (TWA, short term). Sensitivity analyses using TOBIT regression suggested that the average bias caused by excluding non-detects is approximately 30%, being potentially higher for short-term data if many non-detects were actually short-term measurements. Although limited by availability of relevant exposure determinants and potential selection biases in IMIS, these results provide useful insight on formaldehyde occupational exposure in the United States in the last

  10. Relative impact of short-term emissions controls on gas and particle-phase oxidative potential during the 2015 China Victory Day Parade in Beijing, China

    Science.gov (United States)

    Huang, Wei; Fang, Dongqing; Shang, Jing; Li, Zhengqiang; Zhang, Yang; Huo, Peng; Liu, Zhaoying; Schauer, James J.; Zhang, Yuanxun

    2018-06-01

    A field observation focusing on reactive oxygen species (ROS) was conducted before, during, and after the 2015 China Victory Day Parade to understand the influence of short-term emissions controls on atmospheric oxidative activity. The hourly average concentrations of PM2.5, SO2, NO, NO2, CO, O3, as well as gas and particle-phase ROS, were measured using a series of online instruments. PM2.5 concentrations during control days were significantly lower than non-control days, which directly lead to the "Parade Blue", yet reductions of most gaseous pollutants except SO2 were not so obvious as PM. Similarly, the control measures also led to a great loss of particle-phase ROS throughout the control period, while the reduction of ROS in gas phase was not obvious until the more stringent measures implemented since September 1. Furthermore, only weak positive correlations were observed among ROS and some other measured species, indicating ROS concentrations were affected by a number of comprehensive factors that single marker could not capture. Meanwhile, meteorological condition and regional transportation were also shown to be the minor factors affecting atmospheric oxidizing capacity. The results of this observation mainly revealed the control measures were conducive to reducing particle-related ROS. However, the reduction of gas-phase ROS activity was less effective given the menu of controls employed for the 2015 China Victory Day Parade. Therefore, short-term emissions controls only aimed to PM reduction and visibility improvement will produce the blue sky but will not equivalently reduce the gas-phase ROS. Supplemental control measures will be needed to further reduce gas-phase ROS concentrations.

  11. Effect of Short-Term Mobile Phone Base Station Exposure on Cognitive Performance, Body Temperature, Heart Rate and Blood Pressure of Malaysians.

    Science.gov (United States)

    Malek, F; Rani, K A; Rahim, H A; Omar, M H

    2015-08-19

    Individuals who report their sensitivity to electromagnetic fields often undergo cognitive impairments that they believe are due to the exposure of mobile phone technology. The aim of this study is to clarify whether short-term exposure at 1 V/m to the typical Global System for Mobile Communication and Universal Mobile Telecommunications System (UMTS) affects cognitive performance and physiological parameters (body temperature, blood pressure and heart rate). This study applies counterbalanced randomizing single blind tests to determine if sensitive individuals experience more negative health effects when they are exposed to base station signals compared with sham (control) individuals. The sample size is 200 subjects with 50.0% Idiopathic Environmental Intolerance attributed to electromagnetic fields (IEI-EMF) also known as sensitive and 50.0% (non-IEI-EMF). The computer-administered Cambridge Neuropsychological Test Automated Battery (CANTAB eclipse(TM)) is used to examine cognitive performance. Four tests are chosen to evaluate Cognitive performance in CANTAB: Reaction Time (RTI), Rapid Visual Processing (RVP), Paired Associates Learning (PAL) and Spatial Span (SSP). Paired sample t-test on the other hand, is used to examine the physiological parameters. Generally, in both groups, there is no statistical significant difference between the exposure and sham exposure towards cognitive performance and physiological effects (P's > 0.05).

  12. Reduced growth of soybean seedlings after exposure to weak microwave radiation from GSM 900 mobile phone and base station.

    Science.gov (United States)

    Halgamuge, Malka N; Yak, See Kye; Eberhardt, Jacob L

    2015-02-01

    The aim of this work was to study possible effects of environmental radiation pollution on plants. The association between cellular telephone (short duration, higher amplitude) and base station (long duration, very low amplitude) radiation exposure and the growth rate of soybean (Glycine max) seedlings was investigated. Soybean seedlings, pre-grown for 4 days, were exposed in a gigahertz transverse electromagnetic cell for 2 h to global system for mobile communication (GSM) mobile phone pulsed radiation or continuous wave (CW) radiation at 900 MHz with amplitudes of 5.7 and 41 V m(-1) , and outgrowth was studied one week after exposure. The exposure to higher amplitude (41 V m(-1)) GSM radiation resulted in diminished outgrowth of the epicotyl. The exposure to lower amplitude (5.7 V m(-1)) GSM radiation did not influence outgrowth of epicotyl, hypocotyls, or roots. The exposure to higher amplitude CW radiation resulted in reduced outgrowth of the roots whereas lower CW exposure resulted in a reduced outgrowth of the hypocotyl. Soybean seedlings were also exposed for 5 days to an extremely low level of radiation (GSM 900 MHz, 0.56 V m(-1)) and outgrowth was studied 2 days later. Growth of epicotyl and hypocotyl was found to be reduced, whereas the outgrowth of roots was stimulated. Our findings indicate that the observed effects were significantly dependent on field strength as well as amplitude modulation of the applied field. © 2015 Wiley Periodicals, Inc.

  13. Feeling old today? Daily health, stressors, and affect explain day-to-day variability in subjective age.

    Science.gov (United States)

    Kotter-Grühn, Dana; Neupert, Shevaun D; Stephan, Yannick

    2015-01-01

    Subjective age is an important correlate of health, well-being, and longevity. So far, little is known about short-term variability in subjective age and the circumstances under which individuals feel younger/older in daily life. This study examined whether (a) older adults' felt age fluctuates on a day-to-day basis, (b) daily changes in health, stressors, and affect explain fluctuations in felt age, and (c) the daily associations between felt age and health, stressors, or affect are time-ordered. Using an eight-day daily diary approach, N = 43 adults (60-96 years, M = 74.65, SD = 8.19) filled out daily questionnaires assessing subjective age, health, daily stressors, and affect. Data were analysed using multilevel modelling. Subjective age, health, daily stressors, affect. Intra-individual variability in felt age was not explained by time but by short-term variability in other variables. Specifically, on days when participants experienced more than average health problems, stress, or negative affect they felt older than on days with average health, stress, or negative affect. No time-ordered effects were found. Bad health, many stressors, and negative affective experiences constitute circumstances under which older adults feel older than they typically do. Thus, daily measures of subjective age could be markers of health and well-being.

  14. Chronic exposure to chlorpyrifos reveals two modes of action in the springtail Folsomia candida

    Energy Technology Data Exchange (ETDEWEB)

    Jager, Tjalling [Department of Theoretical Biology, Vrije Universiteit, de Boelelaan 1085, NL-1081 HV, Amsterdam (Netherlands)]. E-mail: tjalling@bio.vu.nl; Crommentuijn, Trudie [Ministry of Spatial Planning, Housing and the Environment (VROM), Rijnstraat 8, P.O. Box 30945, 2500 GX, The Hague (Netherlands); Gestel, Cornelis A.M. van [Department of Animal Ecology, Vrije Universiteit, de Boelelaan 1085, NL-1081 HV, Amsterdam (Netherlands); Kooijman, Sebastiaan A.L.M. [Department of Theoretical Biology, Vrije Universiteit, de Boelelaan 1085, NL-1081 HV, Amsterdam (Netherlands)

    2007-01-15

    Organophosphates are popular insecticides, but relatively little is known about their chronic effects on ecologically relevant endpoints. In this paper, we examine a life-cycle experiment with the springtail Folsomia candida, exposed via food to chlorpyrifos (CPF). The results for all endpoints (survival, growth and reproduction) were analyzed using the DEBtox model. Growth was unaffected by CPF, even at concentrations causing severe effects on survival and reproduction. Model analysis suggests that CPF directly affects the process of egg production. For the short-term response (45 days), this single mode of action accurately agreed with the data. However, the full data set (120 days) revealed a dose-related decrease in reproduction at low concentrations after prolonged exposure, not covered by the same mechanism. It appears that CPF interacts with senescence by increasing oxidative damage. This assumption fits the data well, but has little consequences for the predicted response at the population level. - Exposure to chlorpyrifos in food affects reproduction in springtails according to two distinct toxic mechanisms.

  15. Chronic exposure to chlorpyrifos reveals two modes of action in the springtail Folsomia candida

    International Nuclear Information System (INIS)

    Jager, Tjalling; Crommentuijn, Trudie; Gestel, Cornelis A.M. van; Kooijman, Sebastiaan A.L.M.

    2007-01-01

    Organophosphates are popular insecticides, but relatively little is known about their chronic effects on ecologically relevant endpoints. In this paper, we examine a life-cycle experiment with the springtail Folsomia candida, exposed via food to chlorpyrifos (CPF). The results for all endpoints (survival, growth and reproduction) were analyzed using the DEBtox model. Growth was unaffected by CPF, even at concentrations causing severe effects on survival and reproduction. Model analysis suggests that CPF directly affects the process of egg production. For the short-term response (45 days), this single mode of action accurately agreed with the data. However, the full data set (120 days) revealed a dose-related decrease in reproduction at low concentrations after prolonged exposure, not covered by the same mechanism. It appears that CPF interacts with senescence by increasing oxidative damage. This assumption fits the data well, but has little consequences for the predicted response at the population level. - Exposure to chlorpyrifos in food affects reproduction in springtails according to two distinct toxic mechanisms

  16. Comprehensive profiling of mercapturic acid metabolites from dietary acrylamide as short-term exposure biomarkers for evaluation of toxicokinetics in rats and daily internal exposure in humans using isotope dilution ultra-high performance liquid chromatography tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yu [Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, Zhejiang (China); Zhejiang Key Laboratory for Agro-Food Processing, Zhejiang R & D Center for Food Technology and Equipment, Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, Zhejiang (China); Wang, Qiao; Cheng, Jun [Department of Food Science and Nutrition, College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310058, Zhejiang (China); Zhang, Jingshun; Xu, Jiaojiao [Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang (China); Ren, Yiping, E-mail: renyiping@263.net [Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, Zhejiang (China)

    2015-09-24

    Mercapturic acid metabolites from dietary acrylamide are important short-term exposure biomarkers for evaluating the in vivo toxicity of acrylamide. Most of studies have focused on the measurement of two metabolites, N-acetyl-S-(2-carbamoylethyl)-L-cysteine (AAMA) and N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine (GAMA). Thus, the comprehensive profile of acrylamide urinary metabolites cannot be fully understood. We developed an isotope dilution ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous determination of all four mercapturic acid adducts of acrylamide and its primary metabolite glycidamide under the electroscopy ionization negative (ESI-) mode in the present study. The limit of detection (LOD) and limit of quantification (LOQ) of the analytes ranged 0.1–0.3 ng/mL and 0.4–1.0 ng/mL, respectively. The recovery rates with low, intermediate and high spiking levels were calculated as 95.5%–105.4%, 98.2%–114.0% and 92.2%–108.9%, respectively. Acceptable within-laboratory reproducibility (RSD < 7.0%) substantially supported the use of current method for robust analysis. Rapid pretreatment procedures and short run time (8 min per sample) ensured good efficiency of metabolism profiling, indicating a wide application for investigating short-term internal exposure of dietary acrylamide. Our proposed UHPLC-MS/MS method was successfully applied to the toxicokinetic study of acrylamide in rats. Meanwhile, results of human urine analysis indicated that the levels of N-acetyl-S-(2-carbamoylethyl)-L-cysteine-sulfoxide (AAMA-sul), which did not appear in the mercapturic acid metabolites in rodents, were more than the sum of GAMA and N-acetyl-S-(1-carbamoyl-2-hydroxyethyl)-L-cysteine (iso-GAMA). Thus, AAMA-sul may alternatively become a specific biomarker for investigating the acrylamide exposure in humans. Current proposed method provides a substantial methodology support for comprehensive

  17. Comprehensive profiling of mercapturic acid metabolites from dietary acrylamide as short-term exposure biomarkers for evaluation of toxicokinetics in rats and daily internal exposure in humans using isotope dilution ultra-high performance liquid chromatography tandem mass spectrometry

    International Nuclear Information System (INIS)

    Zhang, Yu; Wang, Qiao; Cheng, Jun; Zhang, Jingshun; Xu, Jiaojiao; Ren, Yiping

    2015-01-01

    Mercapturic acid metabolites from dietary acrylamide are important short-term exposure biomarkers for evaluating the in vivo toxicity of acrylamide. Most of studies have focused on the measurement of two metabolites, N-acetyl-S-(2-carbamoylethyl)-L-cysteine (AAMA) and N-acetyl-S-(2-carbamoyl-2-hydroxyethyl)-L-cysteine (GAMA). Thus, the comprehensive profile of acrylamide urinary metabolites cannot be fully understood. We developed an isotope dilution ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous determination of all four mercapturic acid adducts of acrylamide and its primary metabolite glycidamide under the electroscopy ionization negative (ESI-) mode in the present study. The limit of detection (LOD) and limit of quantification (LOQ) of the analytes ranged 0.1–0.3 ng/mL and 0.4–1.0 ng/mL, respectively. The recovery rates with low, intermediate and high spiking levels were calculated as 95.5%–105.4%, 98.2%–114.0% and 92.2%–108.9%, respectively. Acceptable within-laboratory reproducibility (RSD < 7.0%) substantially supported the use of current method for robust analysis. Rapid pretreatment procedures and short run time (8 min per sample) ensured good efficiency of metabolism profiling, indicating a wide application for investigating short-term internal exposure of dietary acrylamide. Our proposed UHPLC-MS/MS method was successfully applied to the toxicokinetic study of acrylamide in rats. Meanwhile, results of human urine analysis indicated that the levels of N-acetyl-S-(2-carbamoylethyl)-L-cysteine-sulfoxide (AAMA-sul), which did not appear in the mercapturic acid metabolites in rodents, were more than the sum of GAMA and N-acetyl-S-(1-carbamoyl-2-hydroxyethyl)-L-cysteine (iso-GAMA). Thus, AAMA-sul may alternatively become a specific biomarker for investigating the acrylamide exposure in humans. Current proposed method provides a substantial methodology support for comprehensive

  18. Programmed flowering of the F1 long-day strawberry cultivar ‘Elan’ with nitrogen and daylength manipulation

    Directory of Open Access Journals (Sweden)

    Edward F. Durner

    2015-12-01

    Full Text Available Consumer demand for locally grown, high quality strawberries is increasing even though California, Florida and Mexico provide a year-round source of strawberries for the world market. In most of the US, locally grown strawberries are only available for a short time in late spring from seasonal fruiting short-day cultivars thus off-season strawberry production is an attractive option for growers. Seed propagated hybrids such as ‘Elan’ are becoming more widely available and offer an alternative to often low yielding cultivars used for off-season production. To determine whether or not ‘Elan’ could be programmed to flower with photoperiod or nitrogen, seedlings were fertilized with either 100 or 800 ppm nitrogen for 4 weeks in September beginning one week after exposure to either short days, the natural photoperiod, or long days, the natural photoperiod supplemented with 24 hours of incandescent radiation. Plants were then greenhouse forced under both photoperiods and floral phenology evaluated. Elevated nitrogen during floral initiation in September enhanced and accelerated flowering and plants receiving elevated nitrogen during initiation under long days flowered more than any other treatment. To determine whether or not flowering could be enhanced a second time in the same plants, another 4 week period of elevated nitrogen was provided in December and plant phenology evaluated through mid-January. Elevated nitrogen (800 ppm in December enhanced December and January flowering. Seedlings were conditioned with elevated nitrogen for a third time in late spring then field planted (early summer on raised beds with white or black plastic mulch. Elevated nitrogen in late spring enhanced yield in field production. No effects of mulch color, initiation photoperiod or interaction of considered factors were detected. Flowering differences detected in greenhouse studies translated into differences observed in the production field suggesting

  19. Global gene expression profiles in brain regions reflecting abnormal neuronal and glial functions targeting myelin sheaths after 28-day exposure to cuprizone in rats

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Hajime [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan); Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193 (Japan); Saito, Fumiyo [Chemicals Evaluation and Research Institute, Japan, 1-4-25 Koraku, Bunkyo-ku, Tokyo 112-0004 (Japan); Tanaka, Takeshi; Mizukami, Sayaka; Watanabe, Yousuke [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan); Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, 1-1 Yanagido, Gifu-shi, Gifu 501-1193 (Japan); Imatanaka, Nobuya; Akahori, Yumi [Chemicals Evaluation and Research Institute, Japan, 1-4-25 Koraku, Bunkyo-ku, Tokyo 112-0004 (Japan); Yoshida, Toshinori [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan); Shibutani, Makoto, E-mail: mshibuta@cc.tuat.ac.jp [Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509 (Japan)

    2016-11-01

    Both developmental and postpubertal cuprizone (CPZ) exposure impairs hippocampal neurogenesis in rats. We previously found that developmental CPZ exposure alters the expression of genes related to neurogenesis, myelination, and synaptic transmission in specific brain regions of offspring. Here, we examined neuronal and glial toxicity profiles in response to postpubertal CPZ exposure by using expression microarray analysis in the hippocampal dentate gyrus, corpus callosum, cerebral cortex, and cerebellar vermis of 5-week-old male rats exposed to 0, 120, and 600 mg/kg CPZ for 28 days. Genes showing transcript upregulation were subjected to immunohistochemical analysis. We found transcript expression alterations at 600 mg/kg for genes related to synaptic transmission, Ache and Prima1, and cell cycle regulation, Tfap4 and Cdkn1a, in the dentate gyrus, which showed aberrant neurogenesis in the subgranular zone. This dose downregulated myelination-related genes in multiple brain regions, whereas KLOTHO{sup +} oligodendrocyte density was decreased only in the corpus callosum. The corpus callosum showed an increase in transcript levels for inflammatory response-related genes and in the number of CD68{sup +} microglia, MT{sup +} astrocytes, and TUNEL{sup +} apoptotic cells. These results suggest that postpubertal CPZ exposure targets synaptic transmission and cell cycle regulation to affect neurogenesis in the dentate gyrus. CPZ suppressed myelination in multiple brain regions and KLOTHO-mediated oligodendrocyte maturation only in the corpus callosum. The increased number of CD68{sup +} microglia, MT{sup +} astrocytes, and TUNEL{sup +} apoptotic cells in the corpus callosum may be involved in the induction of KLOTHO{sup +} oligodendrocyte death and be a protective mechanism against myelin damage following CPZ exposure. - Highlights: • Target gene expression profiles were examined in rats after 28-day CPZ exposure. • Multiple brain region-specific global gene expression

  20. Global gene expression profiles in brain regions reflecting abnormal neuronal and glial functions targeting myelin sheaths after 28-day exposure to cuprizone in rats

    International Nuclear Information System (INIS)

    Abe, Hajime; Saito, Fumiyo; Tanaka, Takeshi; Mizukami, Sayaka; Watanabe, Yousuke; Imatanaka, Nobuya; Akahori, Yumi; Yoshida, Toshinori; Shibutani, Makoto

    2016-01-01

    Both developmental and postpubertal cuprizone (CPZ) exposure impairs hippocampal neurogenesis in rats. We previously found that developmental CPZ exposure alters the expression of genes related to neurogenesis, myelination, and synaptic transmission in specific brain regions of offspring. Here, we examined neuronal and glial toxicity profiles in response to postpubertal CPZ exposure by using expression microarray analysis in the hippocampal dentate gyrus, corpus callosum, cerebral cortex, and cerebellar vermis of 5-week-old male rats exposed to 0, 120, and 600 mg/kg CPZ for 28 days. Genes showing transcript upregulation were subjected to immunohistochemical analysis. We found transcript expression alterations at 600 mg/kg for genes related to synaptic transmission, Ache and Prima1, and cell cycle regulation, Tfap4 and Cdkn1a, in the dentate gyrus, which showed aberrant neurogenesis in the subgranular zone. This dose downregulated myelination-related genes in multiple brain regions, whereas KLOTHO + oligodendrocyte density was decreased only in the corpus callosum. The corpus callosum showed an increase in transcript levels for inflammatory response-related genes and in the number of CD68 + microglia, MT + astrocytes, and TUNEL + apoptotic cells. These results suggest that postpubertal CPZ exposure targets synaptic transmission and cell cycle regulation to affect neurogenesis in the dentate gyrus. CPZ suppressed myelination in multiple brain regions and KLOTHO-mediated oligodendrocyte maturation only in the corpus callosum. The increased number of CD68 + microglia, MT + astrocytes, and TUNEL + apoptotic cells in the corpus callosum may be involved in the induction of KLOTHO + oligodendrocyte death and be a protective mechanism against myelin damage following CPZ exposure. - Highlights: • Target gene expression profiles were examined in rats after 28-day CPZ exposure. • Multiple brain region-specific global gene expression profiling was performed. • CPZ

  1. Worker exposure to methanol vapors during cleaning of semiconductor wafers in a manufacturing setting.

    Science.gov (United States)

    Gaffney, Shannon; Moody, Emily; McKinley, Meg; Knutsen, Jeffrey; Madl, Amy; Paustenbach, Dennis

    2008-05-01

    An exposure simulation was conducted to characterize methanol exposure of workers who cleaned wafers in quality control departments within the semiconductor industry. Short-term (15 min) and long-term (2-4 hr) personal and area samples (at distances of 1 m and 3-6 m from the source) were collected during the 2-day simulation. On the first day, 45 mL of methanol were used per hour by a single worker washing wafers in a 102 m(3) room with a ventilation rate of about 10 air changes per hour (ACH). Virtually all methanol volatilized. To assess exposures under conditions associated with higher productivity, on the second day, two workers cleaned wafers simultaneously, together using methanol at over twice the rate of the first day (95 mL/hr). On this day, the ventilation rate was halved (5 ACH). Personal concentrations on the first day averaged 60 ppm (SD = 46 ppm) and ranged from 10-140 ppm. On the second day, personal concentrations for both workers averaged 118 ppm (SD = 50 ppm; range: 64-270 ppm). Area concentrations measured on the first day at 1 m from the source and throughout the balance of the room averaged 29 ppm (SD = 19 ppm; range: 4-83 ppm) and 18 ppm (SD = 12 ppm; range: 3-42 ppm), respectively. As expected, area concentrations measured on the second day were higher than the first and averaged 73 ppm (SD = 25 ppm; range: 27-140 ppm) at 1 meter and 48 ppm (SD = 13 ppm; range: 21-67 ppm) throughout the balance of the room. The results of this simulation suggest that the use of methanol to clean semiconductor wafers without the use of local exhaust ventilation and with relatively low room ventilation rates is unlikely to result in worker exposures exceeding the current ACGIH(R) threshold limit value of 200 ppm. This study also confirmed prior studies suggesting that when a relatively volatile chemical is located within arm's length (near field), breathing zone concentrations will be about two- to threefold greater than the room concentration when the air

  2. Antioxidative responses of Elodea nuttallii (Planch.) H. St. John to short-term iron exposure.

    Science.gov (United States)

    Xing, Wei; Li, Dunhai; Liu, Guihua

    2010-01-01

    Antioxidative responses of Elodea nuttallii (Planch.) H. St. John to short-term iron exposure were investigated in the study. Results showed that iron accumulation in E. nuttallii was concentration dependent. Growth of E. nuttallii was promoted by low iron concentration (1-10 mg L(-1) [Fe(3+)]), but growth inhibition was observed when iron concentration beyond 10 mg L(-1). The synthesis of protein and pigments increased within 1-10 mg L(-1) [Fe(3+)] range. The activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and glutathione-S-transferase (GST) were up to maximal values at 10 mg L(-1) [Fe(3+)]. High iron concentration inhibited the synthesis of protein and pigments as well as activities of antioxidative enzymes, and accelerated degradation of pigment and production of ROS. Low iron concentration had no significant influences on PSII maximal quantum yield, activity of PSII and relative electron transport rate though PSII. Malondialdehyde (MDA) and proline concentrations were highest at 100 and 1 mg L(-1) [Fe(3+)], respectively. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  3. Isotopic Evidence for Multi-stage Cosmic-ray Exposure Histories of Lunar Meteorites: Long Residence on the Moon and Short Transition to the Earth

    Energy Technology Data Exchange (ETDEWEB)

    Hidaka, Hiroshi; Sakuma, Keisuke [Department of Earth and Planetary Sciences, Nagoya University Nagoya 464-8601 (Japan); Nishiizumi, Kunihiko [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Yoneda, Shigekazu, E-mail: hidaka@eps.nagoya-u.ac.jp [Department of Science and Engineering, National Museum of Nature and Science Tsukuba 305-0005 (Japan)

    2017-06-01

    It is known that most lunar meteorites have complicated cosmic-ray exposure experiences on the Moon and in space. In this study, cosmic-ray irradiation histories of six lunar meteorites, Dhofar 489, Northwest Africa 032 (NWA 032), NWA 479, NWA 482, NWA 2995, and NWA 5000, were characterized from neutron-captured isotopic shifts of Sm and Gd, and from the abundances of long-lived cosmogenic radionuclides like {sup 10}Be, {sup 26}Al, {sup 36}Cl, and {sup 41}Ca. Sm and Gd isotopic data of all of six meteorites show significant isotopic shifts of {sup 149}Sm–{sup 150}Sm and {sup 157}Gd–{sup 158}Gd caused by accumulation of neutron capture reactions due to cosmic-ray irradiation, corresponding to the neutron fluences of (1.3–9.6) × 10{sup 16} n cm{sup −2}. In particular, very large Sm and Gd isotopic shifts of NWA 482 are over those of a lunar regolith 70002, having the largest isotopic shifts among the Apollo regolith samples, corresponding to cosmic-ray exposure duration over 800 million years in the lunar surface (2 π irradiation). Meanwhile, the concentrations of cosmogenic radionuclides for individual six meteorites show the short irradiation time less than one million years as their bodies in space (4 π irradiation). Our data also support the results of previous studies, revealing that most of lunar meteorites have long exposure ages at shallow depths on the Moon and short transit times from the Moon to the Earth.

  4. Short-term hydropower production planning by stochastic programming

    DEFF Research Database (Denmark)

    Fleten, Stein-Erik; Kristoffersen, Trine

    2008-01-01

    -term production planning a matter of spatial distribution among the reservoirs of the plant. Day-ahead market prices and reservoir inflows are, however, uncertain beyond the current operation day and water must be allocated among the reservoirs in order to strike a balance between current profits and expected......Within the framework of multi-stage mixed-integer linear stochastic programming we develop a short-term production plan for a price-taking hydropower plant operating under uncertainty. Current production must comply with the day-ahead commitments of the previous day which makes short...

  5. Estimating Contact Exposure in Football Using the Head Impact Exposure Estimate

    OpenAIRE

    Kerr, Zachary Y.; Littleton, Ashley C.; Cox, Leah M.; DeFreese, J.D.; Varangis, Eleanna; Lynall, Robert C.; Schmidt, Julianne D.; Marshall, Stephen W.; Guskiewicz, Kevin M.

    2015-01-01

    Over the past decade, there has been significant debate regarding the effect of cumulative subconcussive head impacts on short and long-term neurological impairment. This debate remains unresolved, because valid epidemiological estimates of athletes' total contact exposure are lacking. We present a measure to estimate the total hours of contact exposure in football over the majority of an athlete's lifespan. Through a structured oral interview, former football players provided information rel...

  6. The suitability of short-term measurements of radon in the built environment

    International Nuclear Information System (INIS)

    Denman, A.R.; Groves-Kirkby, C.J.; Phillips, P.S.; Crockett, R.G.M.; Woolridge, A.C.

    2008-01-01

    Although domestic and workplace radon concentration levels often show marked diurnal/short-term variation, overall health risk is determined by the long-term average level, and many national protocols advocate the use of long exposure periods, usually three months, to assess long-term risk. Simple passive measurement techniques, e.g. track-etch, activated charcoal and electret, can, however, provide reasonably accurate determinations with exposures as short as one week, and there is pressure from users and stake holders for assessments within this time period. We report evaluation of the effectiveness of one-week, one-month and three-month exposures over a period of one year in a designated Radon Affected Area in the United Kingdom (UK). Although short-term exposures did not compromise measurement accuracy, short-term radon variability rendered one-week measurements less reliable in predicting annual average radon levels via the conventional methodology. Analysis permitted estimation of the maximum and minimum short-term measured domestic radon concentrations at which there was 95% probability of the predicted annual average being below or above the UK Action Level of 200 Bq·m -3 respectively. Between these limits, the short-term result is equivocal, requiring repetition, and the 'equivocal range' for one-week measurements is significantly wider than for three-month exposures. In any geographical area, domestic radon concentrations are distributed log normally, with many properties having low average levels; a small number exhibit excessive levels, and this distribution must be considered when defining exposures for a radon measurement programme. In low-radon areas, where 1% of houses might exceed the Action Level, a one-week assessment will find that fewer outcomes are equivocal. For high-radon areas, with 20% or more houses over the Action Level, more than 50% of one-week outcomes will be equivocal, requiring repeats. The results of this work will be presented

  7. Physiological responses and toxin production of Microcystis aeruginosa in short-term exposure to solar UV radiation.

    Science.gov (United States)

    Hernando, Marcelo; Minaglia, Melina Celeste Crettaz; Malanga, Gabriela; Houghton, Christian; Andrinolo, Darío; Sedan, Daniela; Rosso, Lorena; Giannuzzi, Leda

    2018-01-17

    The aim of this study was to evaluate the effects of short-term (hours) exposure to solar UV radiation (UVR, 280-400 nm) on the physiology of Microcystis aeruginosa. Three solar radiation treatments were implemented: (i) PAR (PAR, 400-700 nm), (ii) TUVA (PAR + UVAR, 315-700 nm) and (iii) TUVR (PAR + UVAR + UVBR, 280-700 nm). Differential responses of antioxidant enzymes and the reactive oxygen species (ROS) production to UVR were observed. Antioxidant enzymes were more active at high UVR doses. However, different responses were observed depending on the exposure to UVAR or UVBR and the dose level. No effects were observed on the biomass, ROS production or increased activity of superoxide dismutase (SOD) and catalase (CAT) compared to the control when UVR + PAR doses were lower than 9875 kJ m -2 . For intermediate doses, UVR + PAR doses between 9875 and 10 275 kJ m -2 , oxidative stress increased while resistance was imparted through SOD and CAT in the cells exposed to UVAR. Despite the increased antioxidant activity, biomass decrease and photosynthesis inhibition were observed, but no effects were observed with added exposure to UVBR. At the highest doses (UVR + PAR higher than 10 275 kJ m -2 ), the solar UVR caused decreased photosynthesis and biomass with only activation of CAT by UVBR and SOD and CAT by UVAR. In addition, for such doses, a significant decrease of microcystins (MCs, measured as MC-LR equivalents) was observed as a consequence of UVAR. This study facilitates our understanding of the SOD and CAT protection according to UVAR and UVBR doses and cellular damage and reinforces the importance of UVR as an environmental stressor. In addition, our results support the hypothesized antioxidant function of MCs.

  8. Short-term, daily exposure to cold temperature may be an efficient way to prevent muscle atrophy and bone loss in a microgravity environment

    Science.gov (United States)

    Deng, Claudia; Wang, Ping; Zhang, Xiangming; Wang, Ya

    2015-04-01

    Microgravity induces less pressure on muscle/bone, which is a major reason for muscle atrophy as well as bone loss. Currently, physical exercise is the only countermeasure used consistently in the U.S. human space program to counteract the microgravity-induced skeletal muscle atrophy and bone loss. However, the routinely almost daily time commitment is significant and represents a potential risk to the accomplishment of other mission operational tasks. Therefore, development of more efficient exercise programs (with less time) to prevent astronauts from muscle atrophy and bone loss are needed. Consider the two types of muscle contraction: exercising forces muscle contraction and prevents microgravity-induced muscle atrophy/bone loss, which is a voluntary response through the motor nervous system; and cold temperature exposure-induced muscle contraction is an involuntary response through the vegetative nervous system, we formed a new hypothesis. The main purpose of this pilot study was to test our hypothesis that exercise at 4 °C is more efficient than at room temperature to prevent microgravity-induced muscle atrophy/bone loss and, consequently reduces physical exercise time. Twenty mice were divided into two groups with or without daily short-term (10 min × 2, at 12 h interval) cold temperature (4 °C) exposure for 30 days. The whole bodyweight, muscle strength and bone density were measured after terminating the experiments. The results from the one-month pilot study support our hypothesis and suggest that it would be reasonable to use more mice, in a microgravity environment and observe for a longer period to obtain a conclusion. We believe that the results from such a study will help to develop efficient exercise, which will finally benefit astronauts' heath and NASA's missions.

  9. Effect of Short-Term Water Exposure on the Mechanical Properties of Halloysite Nanotube-Multi Layer Graphene Reinforced Polyester Nanocomposites

    Directory of Open Access Journals (Sweden)

    Mohd Shahneel Saharudin

    2017-01-01

    Full Text Available The influence of short-term water absorption on the mechanical properties of halloysite nanotubes-multi layer graphene reinforced polyester hybrid nanocomposites has been investigated. The addition of nano-fillers significantly increased the flexural strength, tensile strength, and impact strength in dry and wet conditions. After short-term water exposure, the maximum microhardness, tensile, flexural and impact toughness values were observed at 0.1 wt % multi-layer graphene (MLG. The microhardness increased up to 50.3%, tensile strength increased up to 40% and flexural strength increased up to 44%. Compared to dry samples, the fracture toughness and surface roughness of all types of produced nanocomposites were increased that may be attributed to the plasticization effect. Scanning electron microscopy revealed that the main failure mechanism is caused by the weakening of the nano-filler-matrix interface induced by water absorption. It was further observed that synergistic effects were not effective at a concentration of 0.1 wt % to produce considerable improvement in the mechanical properties of the produced hybrid nanocomposites.

  10. Little field evidence of direct acute and short-term effects of current pesticides on the grey partridge.

    Science.gov (United States)

    Millot, Florian; Berny, Philippe; Decors, Anouk; Bro, Elisabeth

    2015-07-01

    Direct lethal and sublethal effects of pesticides on farmland birds' populations are recurring questions and largely debated. In this context, we conducted an innovative study combining radiotelemetry, farmer surveys, residue analyses on carcasses and modelling to assess the unintentional effects of pesticides on terrestrial birds. We chose the grey partridge Perdix perdix as a case study because this typical bird of European cereal ecosystems is highly exposed to pesticides. In this paper we focused on acute and short-term impacts of pesticides on adult mortality during spring and summer in a one-substance approach (multiple exposure were not studied here) but for a large variety of active substances (a.s.) actually used in cultivated farmland of Northern France. The fate and the location of 529 partridges were monitored twice a day from early March to late August 2010 and 2011 on 12 sites (14,500 ha). Their daily potential exposure to 183 a.s. was determined by overlapping birds' habitat use and daily pesticide application data. Based on this procedure, we calculated mortality rates within 10 days following a potential exposure for 157 different a.s.. 5 a.s. were associated with a "10-day mortality rate" higher than 10% but a single one (thiacloprid) is reported to be highly toxic to birds. We recorded 261 mortalities among which 94 carcasses were in suitable condition for residue analyses. We detected at least one a.s in 39.4% of carcasses. However, only 2 mortality cases were attributed to poisoning (carbofuran). Furthermore, modelling results showed that these lethal pesticide-related poisonings decreased the population growth rate by less than 1%. In conclusion, we did not point out important direct acute and short-term effects of pesticides currently used by farmers during the breeding season on the grey partridge. This is discussed with regards to the complexity of potential effects in operational conditions. Copyright © 2015 Elsevier Inc. All rights

  11. Transcriptional analysis of the unicellular, diazotrophic cyanobacterium Cyanothece sp. ATCC 51142 grown under short day/night cycles

    Energy Technology Data Exchange (ETDEWEB)

    Toepel, Jorg; McDermott, Jason E.; Summerfield, Tina; Sherman, Louis A.

    2009-06-01

    Cyanothece sp. strain ATCC 51142 is a unicellular, diazotrophic cyanobacterium that demonstrates extensive metabolic periodicities of photosynthesis, respiration and nitrogen fixation when grown under N2-fixing conditions. We have performed a global transcription analysis of this organism using 6 h light/dark cycles in order to determine the response of the cell to these conditions and to differentiate between diurnal and circadian regulated genes. In addition, we used a context-likelihood of relatedness (CLR) analysis with this data and those from two-day light/dark and light-dark plus continuous light experiments to better differentiate between diurnal and circadian regulated genes. Cyanothece sp. adapted in several ways to growth under short light/dark conditions. Nitrogen was fixed in every second dark period and only once in each 24 h period. Nitrogen fixation was strongly correlated to the energy status of the cells and glycogen breakdown and high respiration rates were necessary to provide appropriate energy and anoxic conditions for this process. We conclude that glycogen breakdown is a key regulatory step within these complex processes. Our results demonstrated that the main metabolic genes involved in photosynthesis, respiration, nitrogen fixation and central carbohydrate metabolism have strong (or total) circadian-regulated components. The short light/dark cycles enable us to identify transcriptional differences among the family of psbA genes, as well as the differing patterns of the hup genes, which follow the same pattern as nitrogenase genes, relative to the hox genes which displayed a diurnal, dark-dependent gene expression.

  12. Cost-effectiveness comparison between pituitary down-regulation with a gonadotropin-releasing hormone agonist short regimen on alternate days and an antagonist protocol for assisted fertilization treatments.

    Science.gov (United States)

    Maldonado, Luiz Guilherme Louzada; Franco, José Gonçalves; Setti, Amanda Souza; Iaconelli, Assumpto; Borges, Edson

    2013-05-01

    To compare cost-effectiveness between pituitary down-regulation with a GnRH agonist (GnRHa) short regimen on alternate days and GnRH antagonist (GnRHant) multidose protocol on in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) outcome. Prospective, randomized. A private center. Patients were randomized into GnRHa (n = 48) and GnRHant (n = 48) groups. GnRHa stimulation protocol: administration of triptorelin on alternate days starting on the first day of the cycle, recombinant FSH (rFSH), and recombinant hCG (rhCG) microdose. GnRHant protocol: administration of a daily dose of rFSH, cetrorelix, and rhCG microdose. ICSI outcomes and treatment costs. A significantly lower number of patients underwent embryo transfer in the GnRHa group. Clinical pregnancy rate was significantly lower and miscarriage rate was significantly higher in the GnRHa group. It was observed a significant lower cost per cycle in the GnRHa group compared with the GnRHant group ($5,327.80 ± 387.30 vs. $5,900.40 ± 472.50). However, mean cost per pregnancy in the GnRHa was higher than in the GnRHant group ($19,671.80 ± 1,430.00 vs. $11,328.70 ± 907.20). Although the short controlled ovarian stimulation protocol with GnRHa on alternate days, rFSH, and rhCG microdose may lower the cost of an individual IVF cycle, it requires more cycles to achieve pregnancy. NCT01468441. Copyright © 2013 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  13. Effect of exposure on health of atomic bomb servivors

    International Nuclear Information System (INIS)

    Fujitomi, Yutaka; Ueno, Yasushi; Nozaki, Tomoko; Kawaguchi, Fujino; Ishida, Setsuyo

    1976-01-01

    The effects of exposure on vital functions of survivors 30 years after exposure were analyzed, including somatic, psychic, and social factors. Of the survivors living in Nagasaki City, a short-distance exposure group (within 1 km, above 925 rad) and a long-distance exposure group (30 km, 0.6 rad) were selected. The questionnaire included acute symptoms at the time of exposure and present subjective symptoms as indicating vital functions, and psychic factors and medical treatment of exposure as social factors. More of the short-distance exposure group complained of decreased vital functions than did those of the long-distance exposure group. Anxiety was mentioned as one of the causes of the present subjective symptoms. It was not thought that there was relationship between the acute symptoms and the present symptoms. A tendency toward decreased hemoglobin was observed in some of the subjects. (Serizawa, K.)

  14. High exposure to progesterone between the end of menstruation and the day of triggering final oocyte maturation is associated with a decreased probability of pregnancy in patients treated by in vitro fertilization and intracytoplasmic sperm injection.

    Science.gov (United States)

    Kyrou, Dimitra; Kolibianakis, Efstratios M; Fatemi, Human M; Camus, Michel; Tournaye, Herman; Tarlatzis, Basil C; Devroey, Paul

    2011-10-01

    To investigate the association between the probability of pregnancy and hormone exposure between the end of menstruation and the day of triggering final oocyte maturation (menstruation-free interval). Prospective study. University. One hundred women (aged ≤ 39 years) stimulated with a fixed dose of recombinant follicle-stimulating hormone (200 IU). Daily gonadotropin-releasing hormone antagonist (GnRH, 0.25 mg) used from day 6 of stimulation onward, final oocyte maturation triggered by administration of 10,000 IU of human chorionic gonadotropin (hCG) as soon as ≥ 3 follicles ≥ 17 mm were present, and hormone assessment performed at initiation of stimulation, on the first day after menstruation had stopped, on the day of antagonist initiation, and on the day of hCG administration. The association between hormone exposure during the menstruation-free interval and the probability of ongoing pregnancy. The exposure to progesterone during the menstruation-free interval was statistically significantly higher in patients who did not become pregnant compared with those who did (4.20 ± 2.54 vs. 3.13 ± 1.14, respectively). Binary logistic regression confirmed the adverse effect of the increased exposure to progesterone for the achievement of pregnancy. In recombinant follicle-stimulating hormone/gonadotropin-releasing hormone antagonist in vitro fertilization/intracytoplasmic sperm injection cycles, a lower probability of pregnancy is associated with a higher exposure to progesterone during the menstruation-free interval. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  15. Repeated short-term stress synergizes the ROS signalling through up regulation of NFkB and iNOS expression induced due to combined exposure of trichloroethylene and UVB rays.

    Science.gov (United States)

    Ali, Farrah; Sultana, Sarwat

    2012-01-01

    Restraint stress is known to catalyse the pathogenesis of the variety of chronic inflammatory disorders. The present study was designed to evaluate the effect of repeated short-term stress (RRS) on cellular transduction apart from oxidative burden and early tumour promotional biomarkers induced due to combined exposure of trichloroethylene (TCE) and Ultra-violet radiation (UVB). RRS leads to the increase in the expression of the stress responsive cellular transduction elements NFkB-p65 and activity of iNOS in the epidermal tissues of mice after toxicant exposure. RRS augments the steep depletion of the cellular antioxidant machinery which was evidenced by the marked depletion in GSH (Glutathione and GSH dependant enzymes), superoxide dismutase and catalase activity that were observed at significance level of P stressed animals and down regulation of DT-diaphorase activity (P short-term stress in the toxic response of TCE and UVB radiation.

  16. Perinatal exposure to methoxychlor enhances adult cognitive responses and hippocampal neurogenesis in mice.

    Directory of Open Access Journals (Sweden)

    Mariangela eMartini

    2014-06-01

    Full Text Available During perinatal life, sex steroids, such as estradiol, have marked effects on the development and function of the nervous system. Environmental estrogens or xenoestrogens are man-made chemicals, which animal and human population encounter in the environment and which are able to disrupt the functioning of the endocrine system. Scientific interest in the effects of exposure to xenoestrogens has focused more on fertility and reproductive behaviors, while the effects on cognitive behaviors have received less attention. Therefore, the present study explored whether the organochlorine insecticide Methoxychlor (MXC, with known xenoestrogens properties, administered during the perinatal period (from gestational day 11 to postnatal day 8 to pregnant-lactating females, at an environmentally relevant dose (20µg/kg (body weight/day, would also affect learning and memory functions depending on the hippocampus of male and female offspring mice in adulthood. When tested in adulthood, MXC perinatal exposure led to an increase in anxiety-like behavior and in short-term spatial working memory in both sexes. Emotional learning was also assessed using a contextual fear paradigm and MXC treated male and female mice showed an enhanced freezing behavior compared to controls. These results were correlated with an increased survival of adult generated cells in the adult hippocampus. In conclusion, our results show that perinatal exposure to an environmentally relevant dose of MXC has an organizational effect on hippocampus-dependent memory and emotional behaviors.

  17. Repeated exposure to cat urine induces complex behavioral, hormonal, and c-fos mRNA responses in Norway rats ( Rattus norvegicus)

    Science.gov (United States)

    Yin, Baofa; Gu, Chen; Lu, Yi; Hegab, Ibrahim M.; Yang, Shengmei; Wang, Aiqin; Wei, Wanhong

    2017-08-01

    Prey species show specific adaptations that allow recognition, avoidance, and defense against predators. This study was undertaken to investigate the processing of a chronic, life-threatening stimulus to Norway rats ( Rattus norvegicus). One hundred forty-four Norway rats were tested by repeated presentation of cat urine for 1 h at different days in a defensive withdrawal apparatus. Rats exposed to urine for short periods showed significantly larger defensive behavioral and medial hypothalamic c-fos messenger RNA (mRNA) responses than other groups. These defensive responses habituated shortly after the presentation of cat urine. Serum levels of adrenocorticotropic hormone and corticosterone increased significantly when animals were repeatedly exposed to cat urine. However, the hormonal responses took longer to habituate than the behavioral and molecular responses did. We conclude that the behavioral and c-fos mRNA responses are "primed" for habituation to repeated exposures to cat urine, while the hormonal responses show "resistance." The results support our hypothesis that the strongest anti-predator responses at three levels would occur during short-term exposure to cat urine and that these responses would subsequently disappear on prolonged exposure. This study assists understanding the way in which the different levels of defensive responses are integrated and react during chronic stress.

  18. Measuring exposure to protobacco marketing and media: a field study using ecological momentary assessment.

    Science.gov (United States)

    Martino, Steven C; Scharf, Deborah M; Setodji, Claude M; Shadel, William G

    2012-04-01

    The aims of this study were to validate ecological momentary assessment (EMA) as a method for measuring exposure to tobacco-related marketing and media and to use this method to provide detailed descriptive data on college students' exposure to protobacco marketing and media. College students (n = 134; ages 18-24 years) recorded their exposures to protobacco marketing and media on handheld devices for 21 consecutive days. Participants also recalled exposures to various types of protobacco marketing and media at the end of the study period. Retrospectively recalled and EMA-based estimates of protobacco marketing exposure captured different information. The correlation between retrospectively recalled and EMA-logged exposures to tobacco marketing and media was moderate (r = .37, p marketing through multiple channels in a relatively short period: Exposures (M = 8.24, SD = 7.85) occurred primarily in the afternoon (42%), on weekends (35%), and at point-of-purchase locations (68%) or in movies/TV (20%), and exposures to Marlboro, Newport, and Camel represented 56% of all exposures combined and 70% of branded exposures. Findings support the validity of EMA as a method for capturing detailed information about youth exposure to protobacco marketing and media that are not captured through other existing methods. Such data have the potential to highlight areas for policy change and prevention in order to reduce the impact of tobacco marketing on youth.

  19. Association between Short-Term Exposure to Air Pollution and Dyslipidemias among Type 2 Diabetic Patients in Northwest China: A Population-Based Study

    Directory of Open Access Journals (Sweden)

    Minzhen Wang

    2018-03-01

    Full Text Available Air pollution exposure may play an adverse role in diabetes. However, little data are available directly evaluating the effects of air pollution exposure in blood lipids of which dysfunction has been linked to diabetes or its complications. We aimed to evaluate the association between air pollution and lipids level among type 2 diabetic patients in Northwest China. We performed a population-based study of 3912 type 2 diabetes patients in an ongoing cohort study in China. Both spline and multiple linear regressions analysis were used to examine the association between short-term exposure to PM10, SO2, NO2 and total cholesterol (TC, triglycerides (TG, low-density lipoprotein cholesterol (LDL-C, and high-density lipoprotein cholesterol (HDL-C. By spline analyses, we observed that the relationship between SO2 and HDL-C and LDL-C was shown to be non-linear (p_non-lin-association = 0.0162 and 0.000. An inverted U-shaped non-linear relationship between NO2 and LDL-C was found (p_non-lin-association < 0.0001. A J-shaped non-linear relationship between PM10 and TC, HDL-C (p_non-lin-association = 0.0173, 0.0367 was also revealed. In linear regression analyses, a 10 μg/m3 increment in SO2 was associated with 1.31% (95% CI: 0.40–2.12%, 3.52% (95% CI: 1.07–6.03% and 7.53% (95% CI: 5.98–9.09% increase in TC, TG and LDL-C, respectively. A 10 μg/m3 increment in PM10 was associated with 0.45% (95% CI: 0.08–0.82%, 0.29% (95% CI: 0.10–0.49% and 0.83% (95% CI: 0.21–1.45% increase in TC, HDL-C and LDL-C, respectively. For NO2, an increment of 10 μg/m3 was statistically associated with −3.55% (95% CI: −6.40–0.61% and 39.01% (95% CI: 31.43–47.03% increase in HDL-C and LDL-C. The adverse effects of air pollutants on lipid levels were greater in female and elder people. Further, we found SO2 and NO2 played a more evident role in lipid levels in warm season, while PM10 appeared stronger in cold season. The findings suggest that exposure to air

  20. Wheat shorts in diets of gestating swine.

    Science.gov (United States)

    Young, L G; King, G L

    1981-03-01

    Sixty-four gilts were assigned to be bred at first or third observed estrus and fed gestation diets of pelleted wheat shorts with a free choice mineral-vitamin supplement or fortified corn-soybean meal. Only the dietary effects are included in this report. The gilts were fed their respective diets starting at 25 days after insemination. The experiment continued through three gestation-lactation cycles. Females fed the wheat shorts received less digestible energy during gestation and weighed less at day 109 of gestation and days 1, 7 and 21 of lactation in each of the three gestation-lactation periods. Females fed wheat shorts had lighter pigs at birth, weaned more pigs per litter in each parity and returned to estrus more slowly after weaning than females fed a corn-soybean meal diet. Results of a metabolism trial conducted with 12 barrows revealed that wheat shorts contained approximately 2.93 kcal digestible energy/kg dry matter and had an apparent protein digestibility of 72%, compared with values of 4.0 kcal and 86%, respectively, for the corn-soybean meal diets.

  1. Chronic repeated exposure to weather-related stimuli elicits few symptoms of chronic stress in captive molting and non-molting European starlings (Sturnus vulgaris).

    Science.gov (United States)

    de Bruijn, Robert; Reed, J Michael; Romero, L Michael

    2017-10-01

    Repeated exposure to acute stressors causes dramatic changes in an animal's stress physiology and the cumulative effects are often called chronic stress. Recently we showed that short-term exposure to weather-related stimuli, such as temperature change, artificial precipitation, and food restriction, cause acute responses in captive European starlings (Sturnus vulgaris). Here, we examined the effect of repeated exposure to weather-related stressors on heart rate and corticosterone (CORT) of captive non-molting and molting European starlings. Four times every day for 3 weeks, birds were exposed to either 30 min of a subtle (3°C) decrease in temperature, a short bout of simulated rain, or 2 hr of food removal. The order and time of presentation were randomly assigned on each day. We found no differences in heart rate or heart rate variability. Furthermore, there were no changes in baseline CORT levels, CORT negative feedback efficacy, or maximal adrenal capacity. Mass increased across the experimental period only in molting birds. CORT responses to restraint were decreased in both groups following treatment, suggesting the birds had downregulated their responses to acute stress. Molting birds showed evidence of suppression of the HPA axis compared with non-molting birds, which is consistent with previous research. Overall, our data show that repeated exposure to weather-related stressors does not elicit most of the symptoms normally associated with chronic stress. © 2018 Wiley Periodicals, Inc.

  2. Survival of pink salmon (Oncorhynchus gorbuscha) fry to adulthood following a 10-day exposure to aromatic hydrocarbon water-soluble fraction of crude oil and release to the Pacific Ocean

    International Nuclear Information System (INIS)

    Birtwell, I. K.; Fink, R.; Brand, D.; Alexander, R.; McAllister, C. D.

    1999-01-01

    Potential effects of hydrocarbons on salmonids were investigated. In the course of the experiment pink salmon fry were exposed for 10 days to seawater containing varying controlled doses of the water-soluble fractions of North Slope crude oil, comprised primarily of monoaromatics. After exposure the fry were released into the Pacific Ocean to complete their life cycle. The experiments were replicated for three years following the original experiment. No consistent dose-dependent effect of the 10-day exposure on the growth and survival to maturity of the pink salmon was observed, although there was high mortality following each initial release. These results may be considered as one measure of resistance to exposure to contaminants, however, the method is not recommended for general use because it is based on a highly selected sample (i.e. those that survived the initial exposure), and the same results may not apply to populations that have not been subjected to intensive nonselective fishing pressures. In summary, the survival of some fraction of the population of pink salmon is evidence of the robustness of some of these fish, but it is at best a crude indicator of environmental health. 44 refs., 2 tabs., 2 figs

  3. Vitamin D status predicts 30 day mortality in hospitalised cats.

    Directory of Open Access Journals (Sweden)

    Helen Titmarsh

    Full Text Available Vitamin D insufficiency, defined as low serum concentrations of the major circulating form of vitamin D, 25 hydroxyvitamin D (25(OHD, has been associated with the development of numerous infectious, inflammatory, and neoplastic disorders in humans. In addition, vitamin D insufficiency has been found to be predictive of mortality for many disorders. However, interpretation of human studies is difficult since vitamin D status is influenced by many factors, including diet, season, latitude, and exposure to UV radiation. In contrast, domesticated cats do not produce vitamin D cutaneously, and most cats are fed a commercial diet containing a relatively standard amount of vitamin D. Consequently, domesticated cats are an attractive model system in which to examine the relationship between serum 25(OHD and health outcomes. The hypothesis of this study was that vitamin D status would predict short term, all-cause mortality in domesticated cats. Serum concentrations of 25(OHD, together with a wide range of other clinical, hematological, and biochemical parameters, were measured in 99 consecutively hospitalised cats. Cats which died within 30 days of initial assessment had significantly lower serum 25(OHD concentrations than cats which survived. In a linear regression model including 12 clinical variables, serum 25(OHD concentration in the lower tertile was significantly predictive of mortality. The odds ratio of mortality within 30 days was 8.27 (95% confidence interval 2.54-31.52 for cats with a serum 25(OHD concentration in the lower tertile. In conclusion, this study demonstrates that low serum 25(OHD concentration status is an independent predictor of short term mortality in cats.

  4. Health consequences of ionizing radiation exposure

    International Nuclear Information System (INIS)

    Dalci, D.; Dorter, G.; Guclu, I.

    2004-01-01

    The increasing use of ionizing radiations all over the world induces an ever increasing interest of the professionals as well as of the whole society in health protection and the risk due to these practices. Shortly after its discovery, it was recognized that ionizing radiation can have adverse health effects and knowledge of its detrimental effects has accumulated. The fact that ionizing radiation produces biological damage has been known for many years. The biological effects of ionizing radiation for radiation protection considerations are grouped into two categories: The deterministic and the stochastic ones. Deterministic radiation effects can be clinically diagnosed in the exposed individual and occur when above a certain 'threshold' an appropriately high dose is absorbed in the tissues and organs to cause the death of a large number of cells and consequently to impair tissue or organ functions early after exposure. A clinically observable biological effect (Acute Radiation Syndromes, ARS) that occurs days to months after an acute radiation dose. ARS is a complex of acute injury manifestations that occur after a sufficiently large portion of a person's body is exposed to a high dose of ionizing radiation. Such irradiation initially injures all organs to some extent, but the timing and extent of the injury manifestations depend upon the type, rate, and dose of radiation received. Stochastic radiation effects are the chronic effects of radiation result from relatively low exposure levels delivered over long periods of time. These are sort of effects that might result from occupational exposure, or to the background exposure levels (includes radioactive pollution). Such late effects might be the development of malignant (cancerous) disease and of the hereditary consequences. These effects may be observed many years after the radiation exposure. There is a latent period between the initial radiation exposure and the development of the biological effect. In this

  5. Current perspectives in HIV post-exposure prophylaxis

    Directory of Open Access Journals (Sweden)

    Sultan B

    2014-10-01

    Full Text Available Binta Sultan,1,2 Paul Benn,1 Laura Waters1 1Department of Genitourinary Medicine, Mortimer Market Centre, Central and North West London NHS Foundation Trust, London, UK; 2Centre for Sexual Health and HIV Research, University College London, London, UK Abstract: The incidence of human immunodeficiency virus (HIV infection continues to rise among core groups and efforts to reduce the numbers of new infections are being redoubled. Post-exposure prophylaxis (PEP is the use of short-term antiretroviral therapy (ART to reduce the risk of acquisition of HIV infection following exposure. Current guidelines recommend a 28-day course of ART within 36–72 hours of exposure to HIV. As long as individuals continue to be exposed to HIV there will be a role for PEP in the foreseeable future. Nonoccupational PEP, the vast majority of which is for sexual exposure (PEPSE, has a significant role to play in HIV prevention efforts. Awareness of PEP and its availability for both clinicians and those who are eligible to receive it are crucial to ensure that PEP is used to its full potential in any HIV prevention strategy. In this review, we provide current evidence for the use of PEPSE, assessment of the risk of HIV transmission, indications for PEP, drug regimens, and management of patients started on PEP. We summarize national and international guidelines for the use of PEPSE. We explore the place of PEP within the wider strategy of reducing HIV incidence rates in the era of treatment as prevention and pre-exposure prophylaxis. We also consider the implications of recent data from interventional and observational studies demonstrating significant reductions in the risk of HIV transmission within a serodiscordant relationship if the HIV-positive partner is taking effective ART upon PEP guidelines. Keywords: post-exposure prophylaxis, pre-exposure prophylaxis, treatment as prevention, human immunodeficiency virus

  6. Sun exposure and protection behavior of Danish farm children

    DEFF Research Database (Denmark)

    Bodekær, Mette; Øager Petersen, Bibi; Philipsen, Peter Alshede

    2014-01-01

    families) kept daily sun behavior diaries (sun exposure, sunscreen use, sunburns) over a 4-month summer period (15,985 diary days). The Pigment Protection Factor (PPF), an objective measure of sun exposure, was measured at two body sites, before and after summer. All participants presented data from...... the same 115 days. Risk behavior (sun exposure of upper body) took place on 9.5 days (boys) and 15.6 days (girls). Sunburn and sunscreen use were infrequent. Boys' sun exposure resulted in an increased photo protection over the study period of 1.7 SED (upper arm) and 0.8 SED (shoulder) to elicit erythema...

  7. Biochemical and pathological changes in the male rat kidney and bladder following exposure to continuous 900-MHz electromagnetic field on postnatal days 22-59.

    Science.gov (United States)

    Türedi, Sibel; Kerimoğlu, Gökçen; Mercantepe, Tolga; Odacı, Ersan

    2017-09-01

    To investigate the effect on male rat kidney and bladder tissues of exposure to 900-megahertz (MHz) electromagnetic field (EMF) applied on postnatal days 22-59, inclusive. Twenty-four male Sprague Dawley rats, aged 21 days, were used. These were divided equally into one of three groups, control (CG), sham (SG) or EMF (EMFG). CG was not exposed to any procedure. SG rats were kept inside a cage, without being exposed to the effect of EMF, for 1 h a day on postnatal days 22-59, inclusive. EMFG rats were exposed to continuous 900-MHz EMF for 1 h a day under the same conditions as those for the SG rats. Rats were sacrificed on postnatal day 60, and the kidney and bladder tissues were removed. Tissues were stained with hematoxylin and eosin (H&E) and Masson trichrome for histomorphological evaluation. The TUNEL method was used to assess apoptosis. Transmission electron microscopy (TEM) was also used for the kidney tissue. Oxidant/antioxidant parameters were studied in terms of biochemical values. The findings showed that tissue malondialdehyde increased in EMFG compared to CG and SG in both kidney (p = 0.004 and p = 0.004, respectively) and bladder tissue (p = 0.004, p = 0.006, respectively), while catalase and glutathione levels decreased compared to CG (p = 0.004; p = 0.004, respectively) and SG (p = 0.004; p = 0.004, respectively). In the EMF group, pathologies such as dilatation and vacuolization in the distal and proximal tubules, degeneration in glomeruli and an increase in cells tending to apoptosis were observed in kidney tissue. In bladder tissue, degeneration in the transitional epithelium and stromal irregularity and an increase in cells tending to apoptosis were observed in EMFG. Additionally, EMFG samples exhibited glomerular capillary degeneration with capillary basement membranes under TEM. We conclude that continuous exposure to the effect of 900-MHz EMF for 1 h a day on postnatal days 22-59, inclusive, causes an

  8. Using exposure windows to explore an elusive biomarker: blood manganese.

    Science.gov (United States)

    Baker, Marissa G; Stover, Bert; Simpson, Christopher D; Sheppard, Lianne; Seixas, Noah S

    2016-05-01

    We sought to understand the time course between exposure to manganese (Mn) and uptake into the blood, to allow a more meaningful interpretation of exposure biomarker data, and to determine the utility of blood as a biomarker of Mn exposure. Welder trainees were monitored over the course of a five-quarter training program. Each quarter, trainees gave eight blood samples and had personal air monitoring four times. A mixed model was fit to obtain estimates of airborne exposure by welding type (fixed effect), adjusted for subject (random effect). Considering weekends and days absent as zero exposure, estimated exposures were summed over various exposure windows and related to measured blood manganese (MnB) using a mixed model. A relationship consistent with zero was found between MnB and modeled 1 or 7 days of exposure. After 30 days of preceding exposure, a 1 mg-days/m(3) increase in air Mn is associated with a 0.57 ng/mL increase in MnB (95% CI -0.04, 1.19). Considering a 90-day exposure window and a cumulative exposure window, a 1 mg-days/m(3) increase in air Mn is associated with a 0.26 (95% CI 0.005, 0.51) and 0.09 (95% CI 0.006, 0.17) ng/mL increase in MnB, respectively. From this analysis, MnB may begin to act as a biomarker of Mn exposure over longer time periods, or at higher levels of exposure. This novel study design allowed investigation of how MnB relates to different time windows of exposure, representing the most robust Mn exposure assessment in the biomarker literature.

  9. Three-day clotrimazole treatment in candidal vulvovaginitis.

    Science.gov (United States)

    Masterton, G; Napier, I R; Henderson, J N; Roberts, J E

    1977-01-01

    The accepted modern practice is to treat each sexually transmitted disease with the shortest possible course of treatment consistent with success. In candidal vulvovaginitis, six days is the minimum period that has so far been found to be successful, but we report here a further reduction to three days. Patients were given two clotrimazole pessaries nightly for three consecutive nights; the overall success rate was 89-4% one month after treatment. This compares favourably with the 93% cure rate reported with the six-day course of clotrimazole. With both the long and short courses, patients having their first attack of genital candidosis responded better than those with a history of previous infection. Short courses of clotrimazole treatment are particularly valuable in dealing with uncooperative women who stop treatment at the earliest possible moment. Clinical and laboratory diagnostic pitfalls and their possible influence upon the therapeutic outcome are also discussed. PMID:870143

  10. Influence of exposure time on the distribution of cadmium within the cladoceran Ceriodaphnia dubia

    International Nuclear Information System (INIS)

    Munger, C.; Hare, L.; Craig, A.; Charest, P.-M.

    1998-01-01

    The internal distribution of a trace metal can be useful in determining in which body organ toxic effects are most likely to occur and the animal function most likely to be affected. In addition, because a metal's distribution within an organism is likely to influence the rate and efficiency with which it is transferred to a higher trophic level, laboratory measurements of trophic transfer could be influenced by exposure duration. We compared the internal distribution of cadmium (Cd) in a cladoceran crustacean (Ceriodaphnia dubia) destined as food for a predatory insect (Chaoborus) after either a 1 day or a lifetime of exposure of prey to the trace metal. Prey were exposed to 112+109 Cd in both water (10 nM) and their food (algae), as might occur in nature. The internal distribution of 109 Cd in the cladoceran was determined by whole-animal autoradiography. Both the amount and the tissue distribution of Cd in prey were the same after the short and the long term exposures, suggesting that metal accumulation parameters measured after short-term metal exposures can be valid for this animal. Cadmium was mainly accumulated in diverticula of the anterior midgut, a region reported to be responsible for nutrient absorption. We hypothesize that Cd is accumulated in the diverticula because of their purported role as sites of calcium uptake. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. Human exposure to unconventional natural gas development: A public health demonstration of periodic high exposure to chemical mixtures in ambient air.

    Science.gov (United States)

    Brown, David R; Lewis, Celia; Weinberger, Beth I

    2015-01-01

    Directional drilling and hydraulic fracturing of shale gas and oil bring industrial activity into close proximity to residences, schools, daycare centers and places where people spend their time. Multiple gas production sources can be sited near residences. Health care providers evaluating patient health need to know the chemicals present, the emissions from different sites and the intensity and frequency of the exposures. This research describes a hypothetical case study designed to provide a basic model that demonstrates the direct effect of weather on exposure patterns of particulate matter smaller than 2.5 microns (PM2.5) and volatile organic chemicals (VOCs). Because emissions from unconventional natural gas development (UNGD) sites are variable, a short term exposure profile is proposed that determines 6-hour assessments of emissions estimates, a time scale needed to assist physicians in the evaluation of individual exposures. The hypothetical case is based on observed conditions in shale gas development in Washington County, Pennsylvania, and on estimated emissions from facilities during gas development and production. An air exposure screening model was applied to determine the ambient concentration of VOCs and PM2.5 at different 6-hour periods of the day and night. Hourly wind speed, wind direction and cloud cover data from Pittsburgh International Airport were used to calculate the expected exposures. Fourteen months of daily observations were modeled. Higher than yearly average source terms were used to predict health impacts at periods when emissions are high. The frequency and intensity of exposures to PM2.5 and VOCs at a residence surrounded by three UNGD facilities was determined. The findings show that peak PM2.5 and VOC exposures occurred 83 times over the course of 14 months of well development. Among the stages of well development, the drilling, flaring and finishing, and gas production stages produced higher intensity exposures than the

  12. Exposure to 16O-particle radiation causes aging-like decrements in rats through increased oxidative stress, inflammation and loss of autophagy.

    Science.gov (United States)

    Poulose, Shibu M; Bielinski, Donna F; Carrihill-Knoll, Kirsty; Rabin, Bernard M; Shukitt-Hale, Barbara

    2011-12-01

    Exposing young rats to particles of high energy and charge (HZE particles), a ground-based model for exposure to cosmic rays, enhances indices of oxidative stress and inflammation, disrupts the functioning of neuronal communication, and alters cognitive behaviors. Even though exposure to HZE particles occurs at low fluence rates, the cumulative effects of long-term exposure result in molecular changes similar to those seen in aged animals. In the present study, we assessed markers of autophagy, a dynamic process for intracellular degradation and recycling of toxic proteins and organelles, as well as stress and inflammatory responses, in the brains of Sprague-Dawley rats irradiated at 2 months of age with 5 and 50 cGy and 1 Gy of ionizing oxygen particles ((16)O) (1000 MeV/n). Compared to nonirradiated controls, exposure to (16)O particles significantly inhibited autophagy function in the hippocampus as measured by accumulation of ubiquitin inclusion bodies such as P62/SQSTM1, autophagosome marker microtubule-associated protein 1 beta light chain 3 (MAP1B-LC3), beclin1 and proteins such as mammalian target of rapamycin (mTOR). The molecular changes measured at short (36 h) and long (75 days) intervals after (16)O-particle exposure indicate that the loss of autophagy function occurred shortly after exposure but was recovered via inhibition of mTOR. However, HZE-particle radiation caused significant sustained loss of protein kinase C alpha (PKC-α), a key G protein modulator involved in neuronal survival and functions of neuronal trophic factors. Exposure to (16)O particles also caused substantial increases in the levels of nuclear factor kappa B (NF-κB) and glial fibrillary acidic protein (GFAP), indicating glial cell activation 75 days after exposure. This is the first report to show the molecular effects of (16)O-particle radiation on oxidative stress, inflammation and loss of autophagy in the brain of young rats.

  13. Associations between short-term exposure to ambient sulfur dioxide and increased cause-specific mortality in 272 Chinese cities.

    Science.gov (United States)

    Wang, Lijun; Liu, Cong; Meng, Xia; Niu, Yue; Lin, Zhijing; Liu, Yunning; Liu, Jiangmei; Qi, Jinlei; You, Jinling; Tse, Lap Ah; Chen, Jianmin; Zhou, Maigeng; Chen, Renjie; Yin, Peng; Kan, Haidong

    2018-04-28

    Ambient sulfur dioxide (SO 2 ) remains a major air pollutant in developing countries, but epidemiological evidence about its health effects was not abundant and inconsistent. To evaluate the associations between short-term exposure to SO 2 and cause-specific mortality in China. We conducted a nationwide time-series analysis in 272 major Chinese cities (2013-2015). We used the over-dispersed generalized linear model together with the Bayesian hierarchical model to analyze the data. Two-pollutant models were fitted to test the robustness of the associations. We conducted stratification analyses to examine potential effect modifications by age, sex and educational level. On average, the annual-mean SO 2 concentrations was 29.8 μg/m 3 in 272 cities. We observed positive and associations of SO 2 with total and cardiorespiratory mortality. A 10 μg/m 3 increase in two-day average concentrations of SO 2 was associated with increments of 0.59% in mortality from total non-accidental causes, 0.70% from total cardiovascular diseases, 0.55% from total respiratory diseases, 0.64% from hypertension disease, 0.65% from coronary heart disease, 0.58% from stroke, and 0.69% from chronic obstructive pulmonary disease. In two-pollutant models, there were no significant differences between single-pollutant model and two-pollutant model estimates with fine particulate matter, carbon monoxide and ozone, but the estimates decreased substantially after adjusting for nitrogen dioxide, especially in South China. The associations were stronger in warmer cities, in older people and in less-educated subgroups. This nationwide study demonstrated associations of daily SO 2 concentrations with increased total and cardiorespiratory mortality, but the associations might not be independent from NO 2 . Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Short-Term Exposure to Electromagnetic Fields Generated by Mobile Phone Jammers Decreases the Fasting Blood Sugar in Adult Male Rats.

    Science.gov (United States)

    Shekoohi Shooli, F; Mortazavi, S A R; Jarideh, S; Nematollahii, S; Yousefi, F; Haghani, M; Mortazavi, S M J; Shojaei-Fard, M B

    2016-03-01

    Substantial evidence indicates that exposure to electromagnetic fields (EMF) above certain levels can affect human health through triggering some biological responses. According to WHO, short-term exposure to EMF at the levels present in the home/environment do not cause any apparent detrimental effects in healthy individuals. However, now, there is a debate on whether long-term exposure to low level EMF can evoke detrimental biological responses. Although based on the Communications Act of 1934, selling, advertising, using, or importing mobile jammers which block cell phone calls and text messages are illegal acts, in some countries these devices are being used for security purpose and for prevention of cheating during examinations. In this study 30 male Wistar rats were randomly divided into 3 groups of 10 each. The control group received no radiation. The sham exposure group was exposed to a switched-off jammer device. After fasting for 12 hours, the exposure group was exposed to EMFs at a distance of 50 cm from the jammer. Blood samples were collected from the tail vein after 24, 48 and72 hours and fasting blood sugar was measured by using a common blood glucose monitor (BIONIME GM110, Taiwan). The significance level was considered 5% and SPSS Ver. 21 was used for statistical analysis. The data were analyzed by ANOVA followed by Tukey's test. A statistically significant difference was observed between blood sugar level in the control and exposure groups after 24, 48 and 72 hours of continuous irradiation (p values were mobile phone jammer can reduce blood sugar level in adult male rats. These findings, in contrast with our previous results, lead us to this conclusion that the use of these signal blocking devices in very specific circumstances may have some therapeutic effects. However, further studies have to be performed to find out the exact mechanism by which Jammer EMFs reduce fasting blood sugar.

  15. Bisphenol A (BPA) in the serum of pet dogs following short-term consumption of canned dog food and potential health consequences of exposure to BPA.

    Science.gov (United States)

    Koestel, Zoe L; Backus, Robert C; Tsuruta, Kaoru; Spollen, William G; Johnson, Sarah A; Javurek, Angela B; Ellersieck, Mark R; Wiedmeyer, Charles E; Kannan, Kurunthachalam; Xue, Jingchuan; Bivens, Nathan J; Givan, Scott A; Rosenfeld, Cheryl S

    2017-02-01

    Bisphenol A (BPA) is a widely present endocrine disruptor chemical found in many household items. Moreover, this chemical can bioaccumulate in various terrestrial and aquatic sources; thereby ensuring continual exposure of animals and humans. For most species, including humans, diet is considered the primary route of exposure. However, there has been little investigation whether commercial-brands of dog foods contain BPA and potential health ramifications of BPA-dietary exposure in dogs. We sought to determine BPA content within dog food, whether short-term consumption of these diets increases serum concentrations of BPA, and potential health consequences, as assessed by potential hematological, serum chemistry, cortisol, DNA methylation, and gut microbiome changes, in dogs associated with short-term dietary exposure to BPA. Fourteen healthy privately-owned dogs were used in this study. Blood and fecal samples were collected prior to dogs being placed for two-weeks on one of two diets (with one considered to be BPA-free), and blood and fecal samples were collected again. Serum/plasma samples were analyzed for chemistry and hematology profiles, cortisol concentrations, 5-methylcytosine in lymphocytes, and total BPA concentrations. Fecal samples were used for microbiome assessments. Both diets contained BPA, and after two-weeks of being on either diet, dogs had a significant increase in circulating BPA concentrations (pre-samples=0.7±0.15ng/mL, post-samples=2.2±0.15ng/mL, pfood increased circulating BPA concentrations in dogs comparable to amounts detected in humans, and greater BPA concentrations were associated with serum chemistry and microbiome changes. Dogs, who share our internal and external environments with us, are likely excellent indicators of potential human health concerns to BPA and other environmental chemicals. These findings may also have relevance to aquatic and terrestrial wildlife. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. GSM base stations: short-term effects on well-being.

    Science.gov (United States)

    Augner, Christoph; Florian, Matthias; Pauser, Gernot; Oberfeld, Gerd; Hacker, Gerhard W

    2009-01-01

    The purpose of this study was to examine the effects of short-term GSM (Global System for Mobile Communications) cellular phone base station RF-EMF (radiofrequency electromagnetic fields) exposure on psychological symptoms (good mood, alertness, calmness) as measured by a standardized well-being questionnaire. Fifty-seven participants were selected and randomly assigned to one of three different exposure scenarios. Each of those scenarios subjected participants to five 50-min exposure sessions, with only the first four relevant for the study of psychological symptoms. Three exposure levels were created by shielding devices in a field laboratory, which could be installed or removed during the breaks between sessions such that double-blinded conditions prevailed. The overall median power flux densities were 5.2 microW/m(2) during "low," 153.6 microW/m(2) during "medium," and 2126.8 microW/m(2) during "high" exposure sessions. For scenario HM and MH, the first and third sessions were "low" exposure. The second session was "high" and the fourth was "medium" in scenario HM; and vice versa for scenario MH. Scenario LL had four successive "low" exposure sessions constituting the reference condition. Participants in scenarios HM and MH (high and medium exposure) were significantly calmer during those sessions than participants in scenario LL (low exposure throughout) (P = 0.042). However, no significant differences between exposure scenarios in the "good mood" or "alertness" factors were obtained. We conclude that short-term exposure to GSM base station signals may have an impact on well-being by reducing psychological arousal. (c) 2008 Wiley-Liss, Inc.

  17. Impact of short-term preconceptional exposure to particulate air pollution on treatment outcome in couples undergoing in vitro fertilization and embryo transfer (IVF/ET)

    Science.gov (United States)

    Maluf, Mariangela; Czeresnia, Carlos Eduardo; Januário, Daniela Aparecida Nicolosi Foltran; Saldiva, Paulo Hilário Nascimento

    2010-01-01

    Purpose To assess the potential effects of short-term exposure to particulate air pollution during follicular phase on clinical, laboratory, and pregnancy outcomes of women undergoing IVF/ET. Methods Retrospective cohort study of 400 first IVF/ET cycles of women exposed to ambient particulate matter during follicular phase. Particulate matter (PM) was categorized into quartiles (Q1: ≤30.48 µg/m3, Q2: 30.49–42.00 µg/m3, Q3: 42.01–56.72 µg/m3, and Q4: >56.72 µg/m3). Results Clinical, laboratory, or treatment variables were not affected by follicular phase PM exposure periods. Women exposed to Q4 period during the follicular phase of conception cycles had a higher risk of miscarriage (odds ratio, 5.05; 95% confidence interval: 1.04–25.51) when compared to women exposed to Q1–3 periods. Conclusion Our results show an association between brief exposure to high levels of ambient PM during the preconceptional period and early pregnancy loss, although no effect of this exposure on clinical, laboratory, and treatment outcomes was observed. PMID:20405197

  18. T cell potentiation in normal and autoimmune-prone mice after extended exposure to low doses of ionizing radiation and/or caloric restriction

    Energy Technology Data Exchange (ETDEWEB)

    James, S.J.; Makinodan, T.

    1988-01-01

    In order to better understand the apparent physiologic up-regulation in response to low levels of potentially lethal insults, murine T lymphocytes were analysed for functional and phenotypic alterations after exposure to 0.005 Gy/day, 0.01 Gy/day and 0.04 Gy/day in groups of ad-libitum-fed and calorie-restricted mice. Studies were conducted in two strains of mice: long-lived and immunologically normal C57B1/6 +/+ and congenic short-lived immunologically depressed C57B1/6 1pr/1pr. Whole-body exposure to 0.01 Gy/day and 0.04 Gy/day for an extended period of 20 days was associated with an increase in splenic proliferative response and shifts in proportions of T cell subpopulations in the thymus and spleen of both strains. Caloric restriction independently altered functional activity and T cell subpopulations in the same direction as low dose rates of ionizing radiation. Although dose-response augmentation in proliferative activity was similar in the strains, observed alterations in thymic and splenic T cell subpopulations were clearly different, suggesting different mechanisms were responsible for immune enhancement in each strain.

  19. Respiratory and inflammatory responses to short-term exposure to traffic-related air pollution with and without moderate physical activity.

    Science.gov (United States)

    Kubesch, Nadine Janet; de Nazelle, Audrey; Westerdahl, Dane; Martinez, David; Carrasco-Turigas, Gloria; Bouso, Laura; Guerra, Stefano; Nieuwenhuijsen, Mark J

    2015-04-01

    Exposure to traffic-related air pollution (TRAP) has been associated with adverse respiratory and systemic outcomes. Physical activity (PA) in polluted air may increase pollutant uptake and thereby health effects. The authors aimed to determine the short-term health effects of TRAP in healthy participants and any possible modifying effect of PA. Crossover real-world exposure study comparing in 28 healthy participants pulmonary and inflammatory responses to four different exposure scenarios: 2 h exposure in a high and low TRAP environment, each at rest and in combination with intermittent moderate PA, consisting of four 15 min rest and cycling intervals. Data were analysed using mixed effect models for repeated measures. Intermittent PA compared to rest, irrespective of the TRAP exposure status, increased statistically significant (p≤0.05) pulmonary function (forced expiratory volume in 1 s (34 mL), forced vital capacity (29 mL), forced expiratory flow (FEF25-75%) (91 mL)), lung inflammation (fraction of exhaled nitric oxide, FeNO, (0.89 ppb)), and systemic inflammation markers interleukin-6 (52.3%), leucocytes (9.7%) and neutrophils count (18.8%). Interquartile increases in coarse particulate matter were statistically significantly associated with increased FeNO (0.80 ppb) and neutrophil count (5.7%), while PM2.5 and PM10 (particulate matter smaller than 2.5 and 10 µm in diameter, respectively) increased leucocytes (5.1% and 4.0%, respectively). We found no consistent evidence for an interaction between TRAP and PA for any of the outcomes of interest. In a healthy population, intermittent moderate PA has beneficial effects on pulmonary function even when performed in a highly polluted environment. This study also suggests that particulate air pollution is inducing pulmonary and systemic inflammatory responses. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  20. Postnatal exposure to PCB 153 and PCB 180, but not to PCB 52, produces changes in activity level and stimulus control in outbred male Wistar Kyoto rats

    Directory of Open Access Journals (Sweden)

    Walaas S

    2011-05-01

    Full Text Available Abstract Background Polychlorinated biphenyls (PCBs are a class of organic compounds that bioaccumulate due to their chemical stability and lipophilic properties. Humans are prenatally exposed via trans-placental transfer, through breast milk as infants, and through fish, seafood and fatty foods as adolescents and adults. Exposure has several reported effects ranging from developmental abnormalities to cognitive and motor deficiencies. In the present study, three experimental groups of rats were orally exposed to PCBs typically found in human breast milk and then behaviorally tested for changes in measures of stimulus control (percentage lever-presses on the reinforcer-producing lever, activity level (responses with IRTs > 0.67 s, and responses with short IRTs ( Methods Male offspring from Wistar Kyoto (WKY/NTac dams purchased pregnant from Taconic Farms (Germantown, NY were orally given PCB at around postnatal day 8, 14, and 20 at a dose of 10 mg/kg body weight at each exposure. Three experimental groups were exposed either to PCB 52, PCB 153, or PCB 180. A fourth group fed corn oil only served as controls. From postnatal day 25, for 33 days, the animals were tested for behavioral changes using an operant procedure. Results PCB exposure did not produce behavioral changes during training when responding was frequently reinforced using a variable interval 3 s schedule. When correct responses were reinforced on a variable interval 180 s schedule, animals exposed to PCB 153 or PCB 180 were less active than controls and animals exposed to PCB 52. Stimulus control was better in animals exposed to PCB 180 than in controls and in the PCB 52 group. Also, the PCB 153 and PCB 180 groups had fewer responses with short IRTs than the PCB 52 group. No effects of exposure to PCB 52 were found when compared to controls. Conclusions Exposure to PCBs 153 and 180 produced hypoactivity that continued at least five weeks after the last exposure. No effects of

  1. Personal carbon monoxide exposures of preschool children in Helsinki, Finland - comparison to ambient air concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Alm, S.; Mukala, K.; Tittanen, P.; Jantunen, M.J. [KTL National Public Health Institute, Kuopio (Finland). Dept. of Environmental Health

    2001-07-01

    The associations of personal carbon monoxide (CO) exposures with ambient air CO concentrations measured at fixed monitoring sites, were studied among 194 children aged 3-6yr in four downtown and four suburban day-care centers in Helsinki, Finland. Each child carried a personal CO exposure monitor between 1 and 4 times for a time period of between 20 and 24h. CO concentrations at two fixed monitoring sites were measured simultaneously. The CO concentrations measured at the fixed monitoring sites were usually lower (mean maximum 8-h concentration: 0.9 and 2.6mgm{sup -3}) than the personal CO exposure concentrations (mean maximum 8-h concentration: 3.3mgm{sup -3}).The fixed site CO concentrations were poor predictors of the personal CO exposure concentrations. However, the correlations between the personal CO exposure and the fixed monitoring site CO concentrations increased (-0.03 -- -0.12 to 0.13-0.16) with increasing averaging times from 1 to 8h. Also, the fixed monitoring site CO concentrations explained the mean daily or weekly personal CO exposures of a group of simultaneously measured children better than individual exposure CO concentrations. This study suggests that the short-term CO personal exposure of children cannot be meaningfully assessed using fixed monitoring sites. (author)

  2. Estimating the acute health effects of coarse particulate matter accounting for exposure measurement error.

    Science.gov (United States)

    Chang, Howard H; Peng, Roger D; Dominici, Francesca

    2011-10-01

    In air pollution epidemiology, there is a growing interest in estimating the health effects of coarse particulate matter (PM) with aerodynamic diameter between 2.5 and 10 μm. Coarse PM concentrations can exhibit considerable spatial heterogeneity because the particles travel shorter distances and do not remain suspended in the atmosphere for an extended period of time. In this paper, we develop a modeling approach for estimating the short-term effects of air pollution in time series analysis when the ambient concentrations vary spatially within the study region. Specifically, our approach quantifies the error in the exposure variable by characterizing, on any given day, the disagreement in ambient concentrations measured across monitoring stations. This is accomplished by viewing monitor-level measurements as error-prone repeated measurements of the unobserved population average exposure. Inference is carried out in a Bayesian framework to fully account for uncertainty in the estimation of model parameters. Finally, by using different exposure indicators, we investigate the sensitivity of the association between coarse PM and daily hospital admissions based on a recent national multisite time series analysis. Among Medicare enrollees from 59 US counties between the period 1999 and 2005, we find a consistent positive association between coarse PM and same-day admission for cardiovascular diseases.

  3. Long-term Ameliorative Effects of the Antidepressant Fluoxetine Exposure on Cognitive Deficits in 3 × TgAD Mice.

    Science.gov (United States)

    Jin, Li; Gao, Li-Feng; Sun, Dong-Sheng; Wu, Hao; Wang, Qun; Ke, Dan; Lei, Hao; Wang, Jian-Zhi; Liu, Gong-Ping

    2017-08-01

    Fluoxetine, a selective serotonin reuptake inhibitor, is neuroprotective; therefore, it has been applied to treat some neurodegenerative disorders. For instance, chronic fluoxetine exposure has short-term effects on Alzheimer's disease (AD). However, the long-term ameliorative effects of fluoxetine exposure on AD have not been reported. In the present study, 6-month-old 3 × TgAD mice were treated with fluoxetine for 15 days, and then the influence of fluoxetine was detected at 20 days after the drug withdrawal. We found that chronic fluoxetine treatment ameliorated cognitive deficits of 3 × TgAD mice and increased the volume of the hippocampal CA1 and dentate gyrus (DG) with increased neuron number and dendritic spine density. Meanwhile, fluoxetine exposure also stimulated the long-term potentiation (LTP) in hippocampal DG. The synaptic-related protein expression increased via activation of the cyclic AMP response element binding (CREB) protein/brain-derived neurotrophic factor (BDNF) signaling pathway induced by fluoxetine exposure. Lastly, we found that fluoxetine treatment decreased beta-amyloid (Aβ) levels. These results further certified that fluoxetine may be a potent effective drug for AD.

  4. Relative toxicity of bifenthrin to Hyalella azteca in 10 day versus 28 day exposures.

    Science.gov (United States)

    Anderson, Brian S; Phillips, Bryn M; Voorhees, Jennifer P; Petersen, Megan A; Jennings, Lydia L; Fojut, Tessa L; Vasquez, Martice E; Siegler, Catherine; Tjeerdema, Ronald S

    2015-04-01

    Many watersheds in the Central Valley region of California are listed as impaired due to pyrethroid-associated sediment toxicity. The Central Valley Regional Water Quality Control Board is developing numeric sediment quality criteria for pyrethroids, beginning with bifenthrin. Criteria are being developed using existing data, along with data from 10 d and 28 d toxicity tests with Hyalella azteca conducted as part of the current study. A single range-finder and 2 definitive tests were conducted for each test duration. Median lethal concentrations (LC50s), as well as LC20s and inhibition concentrations (IC20s) were calculated based on measured whole sediment bifenthrin concentrations and interstitial water concentrations. Sediment LC50s were also corrected for organic C content. Average LC50s were not significantly different in 10 d versus 28 d tests with H. azteca: 9.1 and 9.6 ng/g bifenthrin for 10 d and 28 d tests, respectively. Average LC20 values were also similar with concentrations at 7.1 and 7.0 for 10 d and 28 d tests, respectively. Bifenthrin inhibition concentrations (IC20s) based on amphipod growth were variable, particularly in the 28 d tests, where a clear dose-response relationship was observed in only 1 of the definitive experiments. Average amphipod growth IC20s were 3.9 and 9.0 ng/g for 10 d and 28 d tests, respectively. Amphipod growth calculated as biomass resulted in IC20s of 4.1 and 6.3 ng/g for the 10 d and 28 d tests, respectively. Lack of a clear growth effect in the longer term test may be related to the lack of food adjustment to account for amphipod mortality in whole sediment exposures. The average C-corrected LC50s were 1.03 and 1.09 μg/g OC for the 10 d and 28 d tests, respectively. Interstitial water LC50s were determined as the measured dissolved concentration of bifenthrin relative to interstitial water dissolved organic carbon. The average LC50s for dissolved interstitial water bifenthrin were

  5. Chronic exposure to Tributyltin induces brain functional damage in juvenile common carp (Cyprinus carpio.

    Directory of Open Access Journals (Sweden)

    Zhi-Hua Li

    Full Text Available The aim of the present study was to investigate the effect of Tributyltin (TBT on brain function and neurotoxicity of freshwater teleost. The effects of long-term exposure to TBT on antioxidant related indices (MDA, malondialdehyde; SOD, superoxide dismutase; CAT, catalase; GR, glutathione reductase; GPx, glutathione peroxidase, Na+-K+-ATPase and neurological parameters (AChE, acetylcholinesterase; MAO, monoamine oxidase; NO, nitric oxide in the brain of common carp were evaluated. Fish were exposed to sublethal concentrations of TBT (75 ng/L, 0.75 μg/L and 7.5 μg/L for 15, 30, and 60 days. Based on the results, a low level and short-term TBT-induced stress could not induce the notable responses of the fish brain, but long-term exposure (more than 15 days to TBT could lead to obvious physiological-biochemical responses (based on the measured parameters. The results also strongly indicated that neurotoxicity of TBT to fish. Thus, the measured physiological responses in fish brain could provide useful information to better understand the mechanisms of TBT-induced bio-toxicity.

  6. Chronic Exposure to Tributyltin Induces Brain Functional Damage in Juvenile Common Carp (Cyprinus carpio)

    Science.gov (United States)

    Li, Zhi-Hua; Li, Ping; Shi, Ze-Chao

    2015-01-01

    The aim of the present study was to investigate the effect of Tributyltin (TBT) on brain function and neurotoxicity of freshwater teleost. The effects of long-term exposure to TBT on antioxidant related indices (MDA, malondialdehyde; SOD, superoxide dismutase; CAT, catalase; GR, glutathione reductase; GPx, glutathione peroxidase), Na+-K+-ATPase and neurological parameters (AChE, acetylcholinesterase; MAO, monoamine oxidase; NO, nitric oxide) in the brain of common carp were evaluated. Fish were exposed to sublethal concentrations of TBT (75 ng/L, 0.75 μg/L and 7.5 μg/L) for 15, 30, and 60 days. Based on the results, a low level and short-term TBT-induced stress could not induce the notable responses of the fish brain, but long-term exposure (more than 15 days) to TBT could lead to obvious physiological-biochemical responses (based on the measured parameters). The results also strongly indicated that neurotoxicity of TBT to fish. Thus, the measured physiological responses in fish brain could provide useful information to better understand the mechanisms of TBT-induced bio-toxicity. PMID:25879203

  7. Chronic exposure to Tributyltin induces brain functional damage in juvenile common carp (Cyprinus carpio).

    Science.gov (United States)

    Li, Zhi-Hua; Li, Ping; Shi, Ze-Chao

    2015-01-01

    The aim of the present study was to investigate the effect of Tributyltin (TBT) on brain function and neurotoxicity of freshwater teleost. The effects of long-term exposure to TBT on antioxidant related indices (MDA, malondialdehyde; SOD, superoxide dismutase; CAT, catalase; GR, glutathione reductase; GPx, glutathione peroxidase), Na+-K+-ATPase and neurological parameters (AChE, acetylcholinesterase; MAO, monoamine oxidase; NO, nitric oxide) in the brain of common carp were evaluated. Fish were exposed to sublethal concentrations of TBT (75 ng/L, 0.75 μg/L and 7.5 μg/L) for 15, 30, and 60 days. Based on the results, a low level and short-term TBT-induced stress could not induce the notable responses of the fish brain, but long-term exposure (more than 15 days) to TBT could lead to obvious physiological-biochemical responses (based on the measured parameters). The results also strongly indicated that neurotoxicity of TBT to fish. Thus, the measured physiological responses in fish brain could provide useful information to better understand the mechanisms of TBT-induced bio-toxicity.

  8. Whole-Body Exposure to 28Si-Radiation Dose-Dependently Disrupts Dentate Gyrus Neurogenesis and Proliferation in the Short Term and New Neuron Survival and Contextual Fear Conditioning in the Long Term.

    Science.gov (United States)

    Whoolery, Cody W; Walker, Angela K; Richardson, Devon R; Lucero, Melanie J; Reynolds, Ryan P; Beddow, David H; Clark, K Lyles; Shih, Hung-Ying; LeBlanc, Junie A; Cole, Mara G; Amaral, Wellington Z; Mukherjee, Shibani; Zhang, Shichuan; Ahn, Francisca; Bulin, Sarah E; DeCarolis, Nathan A; Rivera, Phillip D; Chen, Benjamin P C; Yun, Sanghee; Eisch, Amelia J

    2017-11-01

    Astronauts traveling to Mars will be exposed to chronic low doses of galactic cosmic space radiation, which contains highly charged, high-energy (HZE) particles. 56 Fe-HZE-particle exposure decreases hippocampal dentate gyrus (DG) neurogenesis and disrupts hippocampal function in young adult rodents, raising the possibility of impaired astronaut cognition and risk of mission failure. However, far less is known about how exposure to other HZE particles, such as 28 Si, influences hippocampal neurogenesis and function. To compare the influence of 28 Si exposure on indices of neurogenesis and hippocampal function with previous studies on 56 Fe exposure, 9-week-old C57BL/6J and Nestin-GFP mice (NGFP; made and maintained for 10 or more generations on a C57BL/6J background) received whole-body 28 Si-particle-radiation exposure (0, 0.2 and 1 Gy, 300 MeV/n, LET 67 KeV/μ, dose rate 1 Gy/min). For neurogenesis assessment, the NGFP mice were injected with the mitotic marker BrdU at 22 h postirradiation and brains were examined for indices of hippocampal proliferation and neurogenesis, including Ki67 + , BrdU + , BrdU + NeuN + and DCX + cell numbers at short- and long-term time points (24 h and 3 months postirradiation, respectively). In the short-term group, stereology revealed fewer Ki67 + , BrdU + and DCX + cells in 1-Gy-irradiated group relative to nonirradiated control mice, fewer Ki67 + and DCX + cells in 0.2 Gy group relative to control group and fewer BrdU + and DCX + cells in 1 Gy group relative to 0.2 Gy group. In contrast to the clearly observed radiation-induced, dose-dependent reductions in the short-term group across all markers, only a few neurogenesis indices were changed in the long-term irradiated groups. Notably, there were fewer surviving BrdU + cells in the 1 Gy group relative to 0- and 0.2-Gy-irradiated mice in the long-term group. When the short- and long-term groups were analyzed by sex, exposure to radiation had a similar effect on neurogenesis indices

  9. Exposure experiments of trees to sulfur dioxide gas. Part I

    Energy Technology Data Exchange (ETDEWEB)

    Otani, A.

    1974-12-01

    The effects of gaseous sulfur dioxide on trees were studied. Twenty species of plant seedlings (70 cm in height) including Cedrus deodara, Metasequoia glyptostroboides, Ginkgo biloba, Celmus parvifolia var. albo-marginata, Pinus thumbergii, P. densiflora, Cryptomeria japonica, and Quercus myrsinaefolia, were exposed in a room to gaseous sulfur dioxide at 0.8 ppm for 7.5 hr/day (from 9 am to 4:30 pm) for 24 days at a temperature of 20-35 deg C and RH of 55-75%. Visible damage to plants was lighter in C.j. and Chamae cyparis obtusa, more severe in P.t., G.b., and C.d. The damage appeared earlier in G.b., Cinnamomum camphona, and Ilex rotunda, and the change of early symptoms was smaller in P.t., C.j., and C.o. The leaves of the 4-5th positions from the sprout were apt to be damaged. Although the sulfur content of exposed leaves increased markedly, that in other parts did not increase. Because of the high concentration of the gas and the short period of exposure, the absorption of sulfur into leaves should have differed from the situation in fields where longer exposure to lower concentrations of the gas would be expected. 6 references.

  10. Acute phase response, inflammation and metabolic syndrome biomarkers of Libby asbestos exposure

    Energy Technology Data Exchange (ETDEWEB)

    Shannahan, Jonathan H. [Curriculum in Toxicology, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599 (United States); Alzate, Oscar [Systems Proteomics Center, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599 (United States); Winnik, Witold M.; Andrews, Debora [Proteomics Core, Research Core Unit, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Schladweiler, Mette C. [Cardiopulmonary and Immunotoxicology Branch, Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Ghio, Andrew J. [Clinical Research Branch, Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Chapel Hill, NC 27599 (United States); Gavett, Stephen H. [Cardiopulmonary and Immunotoxicology Branch, Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Kodavanti, Urmila P., E-mail: Kodavanti.Urmila@epa.gov [Cardiopulmonary and Immunotoxicology Branch, Environmental Public Health Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States)

    2012-04-15

    Identification of biomarkers assists in the diagnosis of disease and the assessment of health risks from environmental exposures. We hypothesized that rats exposed to Libby amphibole (LA) would present with a unique serum proteomic profile which could help elucidate epidemiologically-relevant biomarkers. In four experiments spanning varied protocols and temporality, healthy (Wistar Kyoto, WKY; and F344) and cardiovascular compromised (CVD) rat models (spontaneously hypertensive, SH; and SH heart failure, SHHF) were intratracheally instilled with saline (control) or LA. Serum biomarkers of cancer, inflammation, metabolic syndrome (MetS), and the acute phase response (APR) were analyzed. All rat strains exhibited acute increases in α-2-macroglobulin, and α1-acid glycoprotein. Among markers of inflammation, lipocalin-2 was induced in WKY, SH and SHHF and osteopontin only in WKY after LA exposure. While rat strain- and age-related changes were apparent in MetS biomarkers, no LA effects were evident. The cancer marker mesothelin was increased only slightly at 1 month in WKY in one of the studies. Quantitative Intact Proteomic profiling of WKY serum at 1 day or 4 weeks after 4 weekly LA instillations indicated no oxidative protein modifications, however APR proteins were significantly increased. Those included serine protease inhibitor, apolipoprotein E, α-2-HS-glycoprotein, t-kininogen 1 and 2, ceruloplasmin, vitamin D binding protein, serum amyloid P, and more 1 day after last LA exposure. All changes were reversible after a short recovery regardless of the acute or long-term exposures. Thus, LA exposure induces an APR and systemic inflammatory biomarkers that could have implications in systemic and pulmonary disease in individuals exposed to LA. -- Highlights: ► Biomarkers of asbestos exposure are required for disease diagnosis. ► Libby amphibole exposure is associated with increased human mortality. ► Libby amphibole increases circulating proteins involved

  11. Sun exposure patterns of urban, suburban, and rural children

    DEFF Research Database (Denmark)

    Bodekær, Mette; Petersen, Bibi; Philipsen, Peter Alshede

    2015-01-01

    BACKGROUND: Sun exposure is the main etiology of skin cancer. Differences in skin cancer incidence have been observed between rural and urban populations. OBJECTIVES: As sun exposure begins in childhood, we examined summer UVR exposure doses and sun behavior in children resident in urban, suburban......, and rural areas. METHODS: Personal, electronic UVR dosimeters and sun behavior diaries were used during a summer (3.5 months) by 150 children (4-19 years of age) resident in urban, suburban, and rural areas. RESULTS: On school/kindergarten days rural children spent more time outdoors and received higher UVR...... doses than urban and suburban children (rural: median 2.3 h per day, median 0.9 SED per day, urban: median 1.3 h per day, median 0.3 SED per day, suburban: median 1.5 h per day, median 0.4 SED per day) (p ≤ 0.007). Urban and suburban children exhibited a more intermittent sun exposure pattern than rural...

  12. Insecticide Exposure in Parkinsonism.

    Science.gov (United States)

    2000-01-01

    WET (Whole Effluent Toxicity) Testing, SETAC Short Course, 1999 Multivariate Statistical Analysis of Ecotoxicological Data, SETAC Short Course...Chlorpyrifos between water and an aquatic macrophyte (Elodea densa). Chemosphere. 37(8):1579-1586. Karen, DJ, DR Ownby, BS Day, RW Brown, DP Shupack, GP

  13. Short-term exposure to benzo[a]pyrene causes oxidative damage and affects haemolymph steroid levels in female crab Portunus trituberculatus

    International Nuclear Information System (INIS)

    Wen, Jianmin; Pan, Luqing

    2016-01-01

    Concern has increased regarding the adverse effects of polycyclic aromatic hydrocarbons (PAHs) on reproduction. However, limited information is available on the effects of PAHs in crustacean. In order to determine whether benzo[a]pyrene (B[a]P) could cause reproductive toxicity on the swimming crab Portunus trituberculatus, sexually mature female crabs were exposed to environmentally relevant concentrations of B[a]P (0, 0.1, 0.5 and 2.5 μg/L) for 10 days. B[a]P treatments resulted in high accumulation in ovary, and induced oxidative stress in a dose-dependent manner on ovary of crab. Furthermore, the haemolymph estradiol (E_2) and testosterone (T) levels were significantly decreased. Histological investigation also revealed the reproductive toxicity caused by B[a]P. The results demonstrated that waterborne exposure to B[a]P caused oxidative damage and disrupted sex steroids in female crab P. trituberculatus, ultimately resulting in histological alternation. - Highlights: • Waterborne exposure to B[a]P resulted in high accumulation in crab ovary. • The haemolymph 17β-estradiol and testosterone levels were significantly decreased by B[a]P exposure. • B[a]P induced oxidative damage in crab ovary. • B[a]P exposure caused histopathological alterations in crab ovary. - B[a]P disrupted sex steroids, caused oxidative damage and histological alternation in female crab P. trituberculatus.

  14. Approach to stochastic modelling of consumer exposure for any substance from canned foods using simulant migration data.

    Science.gov (United States)

    Castle, L; Hart, A; Holmes, M J; Oldring, P K T

    2006-05-01

    A two-dimensional probabilistic model was constructed to estimate the short-term dietary exposure of UK consumers to any generalized migrant from coated light metal food packaging. Using three UK National Dietary and Nutrition Surveys (NDNS) comprising 4-7-day dietary surveys for different age and gender groups, actual body weights and survey years, a sample representative of the dietary consumption of the UK population was obtained comprising around 4,200 food items. Interrogation of the raw data showed that the per capita consumption of food and beverage for an adult was 2.9 kg per person day(-1), which is comparable with the US FDA value of 3.0 kg. The packaging type of each food item was assigned from the survey descriptions or by sampling from distributions based upon market share information and expert judgement. Each food item was assigned to the relevant food simulant: A (aqueous), B (acidic) or D (fatty), so that simulant migration data could be used. The exposure model was used to evaluate exposure for a given level of migration and, conversely, the level of migration that could be tolerated whilst keeping within a target threshold exposure level. As examples, migration at 10 microg dm(-2) into fatty foods only resulted in an exposure ranging from 0.06 to 0.22 microg kg(-1) body (actual) weight day(-1) depending on the scenario. The model revealed that if migration from metal coatings was only into fatty foods, migration in the range 1.83-4.95 microg dm(2) (97.5th percentile, depending on the scenario) would give an exposure of less than 1.5 microg per person day(-1). This is a toxicological threshold limit used in the USA. If migration into simulants A and B is also considered to be at the same level as that for simulant D, then the level of migration for the threshold to be reached is, not surprisingly, lower (0.64-0.87 microg dm(-2)) than that if migration were only into fatty foods. In this case, clearly the main contributors to the exposure were

  15. Measuring Exposure to Protobacco Marketing and Media: A Field Study Using Ecological Momentary Assessment

    Science.gov (United States)

    Scharf, Deborah M.; Setodji, Claude M.; Shadel, William G.

    2012-01-01

    Introduction: The aims of this study were to validate ecological momentary assessment (EMA) as a method for measuring exposure to tobacco-related marketing and media and to use this method to provide detailed descriptive data on college students’ exposure to protobacco marketing and media. Methods: College students (n = 134; ages 18–24 years) recorded their exposures to protobacco marketing and media on handheld devices for 21 consecutive days. Participants also recalled exposures to various types of protobacco marketing and media at the end of the study period. Results: Retrospectively recalled and EMA-based estimates of protobacco marketing exposure captured different information. The correlation between retrospectively recalled and EMA-logged exposures to tobacco marketing and media was moderate (r = .37, p marketing through multiple channels in a relatively short period: Exposures (M = 8.24, SD = 7.85) occurred primarily in the afternoon (42%), on weekends (35%), and at point-of-purchase locations (68%) or in movies/TV (20%), and exposures to Marlboro, Newport, and Camel represented 56% of all exposures combined and 70% of branded exposures. Conclusions: Findings support the validity of EMA as a method for capturing detailed information about youth exposure to protobacco marketing and media that are not captured through other existing methods. Such data have the potential to highlight areas for policy change and prevention in order to reduce the impact of tobacco marketing on youth. PMID:22039076

  16. Effect of prenatal gamma irradiation on the different gestation days on mouse

    International Nuclear Information System (INIS)

    Baskar, R.; Uma Devi, P.

    1993-01-01

    Pregnant Swiss albino mice were given a single local (abdomen) exposure of 50 cGy gamma radiation on days 1.5 to 17.5 post coitus (p.c.). The animals were sacrificed on 18th day of gestation and the fetuses were dissected out and examined for mortality, growth retardation, sex ratio, changes in body weight and length, head length and width, brain weight and incidence of microphthalmia. Preimplantation exposures (days 1.5 and 3.5 p.c.) resulted in a significant increase in embryonic and fetal mortality, while exposure during the postimplantation period (days 5.5 to 12.5 p.c.) produced a significant increase in the number of growth retarded fetuses. A high incidence of growth retarded fetuses was also observed by irradiation at the late fetal period (17.5 days p.c.). Brain weight was significantly affected by exposure on some days during all the three phases of development, i.e. preimplantation (3.5 days p.c.), mager organogenesis (9.5 to 12.5 days p.c.) and fetal (14.5 and 17.5 days p.c.) periods, though the period of sensitiveness was larger during organogenesis period. Eye development was sensitive to radiation effect mainly during the late organogenesis (9.5 to 12.5 days p.c.). It is concluded that the radiosensitivity of mouse embryos to radiation lethality at low dose is confirmed to the preimplantation period, while growth retardation is a prominent effect of irradiation at the early postimplantation embryos. The late organogenesis, especially from 9.5 to 12.5 days p.c. appears to be a particularly sensitive period in the development of brain and eye, though the sensitivity of brain may continue during the fetal life. (author). 9 refs

  17. Environmental exposure at day care centres: are our children at risk?

    CSIR Research Space (South Africa)

    John, J

    2005-09-01

    Full Text Available This study aimed to characterize the exposure of 5-year old children attending preschool facilities in Pretoria to lead (as an example of an environmental pollutant) in air and surface soil, specifically in relation to their activity patterns....

  18. A probabilistic assessment of health risks associated with short-term exposure to tropospheric ozone

    Energy Technology Data Exchange (ETDEWEB)

    Whitfield, R.G; Biller, W.F.; Jusko, M.J.; Keisler, J.M.

    1996-06-01

    The work described in this report is part of a larger risk assessment sponsored by the U.S. Environmental Protection Agency. Earlier efforts developed exposure-response relationships for acute health effects among populations engaged in heavy exertion. Those efforts also developed a probabilistic national ambient air quality standards exposure model and a general methodology for integrating probabilistic exposure-response relation- ships and exposure estimates to calculate overall risk results. Recently published data make it possible to model additional health endpoints (for exposure at moderate exertion), including hospital admissions. New air quality and exposure estimates for alternative national ambient air quality standards for ozone are combined with exposure-response models to produce the risk results for hospital admissions and acute health effects. Sample results explain the methodology and introduce risk output formats.

  19. Cardiovascular Autonomic Responses in the VCD Rat Model of Menopause: Effects of Short- and Long-Term Ovarian Failure.

    Science.gov (United States)

    Huber, Domitila A; Bazilio, Darlan; Lorenzon, Flaviano; Sehnem, Sibele; Pacheco, Lucas; Anselmo-Franci, Janete A; Lima, Fernanda B

    2017-01-01

    After menopause, hypertension elevates the risk of cardiac diseases, one of the major causes of women's morbidity. The gradual depletion of ovarian follicles in rats, induced by 4-vinylcyclohexene diepoxide (VCD), is a model for studying the physiology of menopause. 4-Vinylcyclohexene diepoxide treatment leads to early ovarian failure (OF) and a hormonal profile comparable to menopause in humans. We have hypothesized that OF can compromise the balance between sympathetic and parasympathetic tones of the cardiovascular system, shifting toward dominance of the former. We aimed to study the autonomic modulation of heart and blood vessels and the cardiovascular reflexes in rats presenting short-term (80 days) or long-term (180 days) OF induced by VCD. Twenty-eight-day-old Wistar rats were submitted to VCD treatment (160 mg/kg, intraperitoneally) or vehicle (control) for 15 consecutive days and experiments were conducted at 80 or 180 days after the onset of treatment. Long-term OF led to an increase in the sympathetic activity to blood vessels and an impairment in the baroreflex control of the heart, evoked by physiological changes in arterial pressure. Despite that, long-term OF did not cause hypertension during the 180 days of exposure. Short-term OF did not cause any deleterious effect on the cardiovascular parameters analyzed. These data indicate that long-term OF does not disrupt the maintenance of arterial pressure homeostasis in rats but worsens the autonomic cardiovascular control. In turn, this can lead to cardiovascular complications, especially when associated with the aging process seen during human menopause.

  20. Short Sleep as an Environmental Exposure: A Preliminary Study Associating 5-HTTLPR Genotype to Self-Reported Sleep Duration and Depressed Mood in First-Year University Students

    Science.gov (United States)

    Carskadon, Mary A.; Sharkey, Katherine M.; Knopik, Valerie S.; McGeary, John E.

    2012-01-01

    Objectives: This study examined whether the 5-HTTLPR polymorphism in the SLC6A4 gene is associated with self-reported symptoms of depressed mood in first-year university students with a persistent pattern of short sleep. Design: Students provided DNA samples and completed on-line sleep diaries and a mood scale during the first semester. A priori phenotypes for nocturnal sleep and mood scores were compared for the distribution of genotypes. Setting: Brown University, Providence, Rhode Island. Participants: A sample of 135 first-year students, 54 male, 71 Caucasian, mean age 18.1 (± 0.5) yr. Interventions: None. Measurements: Students completed on-line sleep diaries daily across the first term (21-64 days; mean = 51 days ± 11) and Center for Epidemiologic Studies-Depression (CES-D) mood scale after 8 wk. DNA was genotyped for the triallelic 5-HTTLPR polymorphism. Low-expressing S and LGpolymorphisms were designated S′, and high-expressing LA was designated L′. Phenotype groups were identified from a combination of CES-D (median split: high > 12; low sleep time (TST) from diaries: (shorter ≤ 7 hr; longer ≥ 7.5 hr). Three genotypes were identified (S′S′, S′L′, L′L′); the S′S′ genotype was present in a higher proportion of Asian than non-Asian students. Results: Four phenotype groups were compared: 40 students with shorter TST/high CES-D; 34 with shorter TST/low CES-D; 29 with longer TST/high CES-D; 32 with longer TST/low CES-D. Female:male distribution did not vary across phenotype groups (chi-square = 1.39; df = 3; P = 0.71). S′S′ participants (n = 23) were overrepresented in the shorter TST/high CES-D group (chi- square = 15.04; df = 6; P sleep and higher depressed mood are more likely than others to carry a variant of the SLC6A4 gene associated with low expression of the serotonin transporter. Citation: Carskadon MA; Sharkey KM; Knopik VS; McGeary JE. Short sleep as an environmental exposure: a preliminary study associating 5-HTTLPR

  1. Comparison of earthworm responses to petroleum hydrocarbon exposure in aged field contaminated soil using traditional ecotoxicity endpoints and 1H NMR-based metabolomics

    International Nuclear Information System (INIS)

    Whitfield Åslund, Melissa; Stephenson, Gladys L.; Simpson, André J.; Simpson, Myrna J.

    2013-01-01

    1 H NMR metabolomics and conventional ecotoxicity endpoints were used to examine the response of earthworms exposed to petroleum hydrocarbons (PHCs) in soil samples collected from a site that was contaminated with crude oil from a pipeline failure in the mid-1990s. The conventional ecotoxicity tests showed that the soils were not acutely toxic to earthworms (average survival ≥90%), but some soil samples impaired reproduction endpoints by >50% compared to the field control soil. Additionally, metabolomics revealed significant relationships between earthworm metabolic profiles (collected after 2 or 14 days of exposure) and soil properties including soil PHC concentration. Further comparisons by partial least squares regression revealed a significant relationship between the earthworm metabolomic data (collected after only 2 or 14 days) and the reproduction endpoints (measured after 63 days). Therefore, metabolomic responses measured after short exposure periods may be predictive of chronic, ecologically relevant toxicity endpoints for earthworms exposed to soil contaminants. -- Highlights: •Earthworm response to petroleum hydrocarbon exposure in soil is examined. •Metabolomics shows significant changes to metabolic profile after 2 days. •Significant relationships observed between metabolomic and reproduction endpoints. •Metabolomics may have value as a rapid screening tool for chronic toxicity. -- Earthworm metabolomic responses measured after 2 and 14 days are compared to traditional earthworm ecotoxicity endpoints (survival and reproduction) in petroleum hydrocarbon contaminated soil

  2. Dynamics of short-term acclimation to UV radiation in marine diatoms.

    Science.gov (United States)

    Fouqueray, Manuela; Mouget, Jean-Luc; Morant-Manceau, Annick; Tremblin, Gérard

    2007-11-12

    In order to investigate the dynamics of the acclimation of marine diatoms to ultraviolet radiation (UVR), Amphora coffeaeformis, Odontella aurita and Skeletonema costatum were exposed for 5 h per day to a combination of UVA and UVB (UVBR/UVAR ratio 4.5%) with a total UVR daily dose of 110 kJ m(-2), which is equivalent to that observed in the natural environment. This treatment was applied in the middle of the photoperiod and was repeated on five successive days. During the UVR treatment, chlorophyll fluorescence parameters were monitored, damage and repair constants were calculated from effective quantum yield values (phi(PSII)), and rapid light curves (electron transport rate versus irradiance curves using short light steps of different intensity) were plotted to determine the maximum relative electron transport rate (rETR(max)) and maximum light use efficiency (alpha). In all species the growth rate was lower than control from day 1-3, but increased thereafter, except for S. costatum. The cellular chlorophyll a content increased significantly with repeated daily exposure to UVR for A. coffeaeformis only. In all species, the fluorescence parameters (F(m), the maximum fluorescence level measured in the dark, phi(PSII), rETR(max) and alpha) decreased during UVR exposure, in contrast to F(0) (the minimum fluorescence level measured in the dark). The response to UVR stress was species-specific. S. costatum was very sensitive, and failed to survive for more than three days, whereas A. coffeaeformis and O. aurita were able to acclimate to UVR stress. These two species used different strategies. In A. coffeaeformis, the repair constant was lower than the damage constant, but phi(PSII) values returned to baseline values at the beginning of each experimental day, indicating that an effective active recovery process occurred after stress. In O. aurita, the repair processes took place during the stress, and could account for the UVR tolerance of this species.

  3. Asbestos exposure among transmission mechanics in automotive repair shops.

    Science.gov (United States)

    Salazar, Natalia; Cely-García, María Fernanda; Breysse, Patrick N; Ramos-Bonilla, Juan Pablo

    2015-04-01

    Asbestos has been used in a broad variety of industrial products, including clutch discs of the transmission system of vehicles. Studies conducted in high-income countries that have analyzed personal asbestos exposures of transmission mechanics have concluded that these workers are exposed to asbestos concentrations in compliance with the US Occupational Safety and Health Administration (US OSHA) occupational standards. Clutch facings are the friction component of clutch discs. If clutch facings are sold separated from the support, they require manipulation before installation in the vehicle. The manipulation of asbestos containing clutch facings is performed by a group of mechanics known as riveters, and includes drilling, countersinking, riveting, sanding, and occasionally grinding, tasks that can potentially release asbestos fibers, exposing the mechanics. These manipulation activities are not reported in studies conducted in high-income countries. This study analyzes personal asbestos exposures of transmission mechanics that manipulate clutch facings. Air sampling campaigns in two transmission repair shops (TRS) were conducted in November 2012 and July 2013 in Bogotá, Colombia. Four workers employed in these TRS were sampled (i.e. three riveters and one supervisor). Personal samples (n = 39), short-term personal samples (n = 49), area samples (n = 52), blank samples (n = 8), and background samples (n = 2) were collected in both TRS during 3-5 consecutive days, following US National Institute for Occupational Safety and Health (US NIOSH) methods 7400 and 7402. Asbestos samples were analyzed by an American Industrial Hygiene Association accredited laboratory. On at least one of the days sampled, all riveters were exposed to asbestos concentrations that exceeded the US OSHA permissible exposure limit or the Colombian permissible limit value. Additionally, from the forty-seven 30-min short-term personal samples collected, two (4.3%) exceeded the US OSHA excursion

  4. Effect of short-term simulated daylight exposure on optically brightened papers

    International Nuclear Information System (INIS)

    Green, Phil; Honess, Mike

    2010-01-01

    Two optically brightened commercial papers were subjected to 72 hours continuous exposure to graphic arts daylight simulating fluorescent lamps at 1.4 and 4.4 klux. At the higher illuminance level, a CIELAB colour difference of 1.0 was reached in approximately 3 and 50 hours for the two papers. The colour differences produced by the 1.4 klux exposure were greater than that predicted by assuming a linear relationship between intensity and colour change, by a factor of 1.8.

  5. Exposure to radiowaves in physiotherapy

    International Nuclear Information System (INIS)

    Gobbato, F.; Valentinuzzi, C.

    1988-01-01

    An assessment of the electromagnetic fields emitted from short and ultra short wave diathermy sources was made to evaluate the hazards to the operator and patient. In ultra short wave diathermy the power density depends on the direction of the emission and decreases with the square of the distance from the source. Regression functions between power density and distance were calculated and analysed statistically. It is possible to calculate a simple algorithm in short wave diathermy, so the field must be mapped from direct measurements. Operator safety is easy to achieve by following simple procedures. Particular caution must be used to protect the patient from exposure of critical biological organs

  6. Degradation of benzodiazepines after 120 days of EMS deployment.

    Science.gov (United States)

    McMullan, Jason T; Jones, Elizabeth; Barnhart, Bruce; Denninghoff, Kurt; Spaite, Daniel; Zaleski, Erin; Silbergleit, Robert

    2014-01-01

    EMS treatment of status epilepticus improves outcomes, but the benzodiazepine best suited for EMS use is unclear, given potential high environmental temperature exposures. To describe the degradation of diazepam, lorazepam, and midazolam as a function of temperature exposure and time over 120 days of storage on active EMS units. Study boxes containing vials of diazepam, lorazepam, and midazolam were distributed to 4 active EMS units in each of 2 EMS systems in the southwestern United States during May-August 2011. The boxes logged temperature every minute and were stored in EMS units per local agency policy. Two vials of each drug were removed from each box at 30-day intervals and underwent high-performance liquid chromatography to determine drug concentration. Concentration was analyzed as mean (and 95%CI) percent of initial labeled concentration as a function of time and mean kinetic temperature (MKT). 192 samples were collected (2 samples of each drug from each of 4 units per city at 4 time-points). After 120 days, the mean relative concentration (95%CI) of diazepam was 97.0% (95.7-98.2%) and of midazolam was 99.0% (97.7-100.2%). Lorazepam experienced modest degradation by 60 days (95.6% [91.6-99.5%]) and substantial degradation at 90 days (90.3% [85.2-95.4%]) and 120 days (86.5% [80.7-92.3%]). Mean MKT was 31.6°C (95%CI 27.1-36.1). Increasing MKT was associated with greater degradation of lorazepam, but not midazolam or diazepam. Midazolam and diazepam experienced minimal degradation throughout 120 days of EMS deployment in high-heat environments. Lorazepam experienced significant degradation over 120 days and appeared especially sensitive to higher MKT exposure.

  7. No adverse lung effects of 7- and 28-day inhalation exposure of rats to emissions from petrodiesel fuel containing 20% rapeseed methyl esters (B20) with and without particulate filter - the FuelHealth project.

    Science.gov (United States)

    Magnusson, Pål; Oczkowski, Michał; Øvrevik, Johan; Gajewska, Malgorzata; Wilczak, Jacek; Biedrzycki, Jacek; Dziendzikowska, Katarzyna; Kamola, Dariusz; Królikowski, Tomasz; Kruszewski, Marcin; Lankoff, Anna; Mruk, Remigiusz; Brunborg, Gunnar; Instanes, Christine; Gromadzka-Ostrowska, Joanna; Myhre, Oddvar

    2017-04-01

    Increased use of biofuels raises concerns about health effects of new emissions. We analyzed relative lung health effects, on Fisher 344 rats, of diesel engine exhausts emissions (DEE) from a Euro 5-classified diesel engine running on petrodiesel fuel containing 20% rapeseed methyl esters (B20) with and without diesel particulate filter (DPF). One group of animals was exposed to DEE for 7 days (6 h/day), and another group for 28 days (6 h/day, 5 days/week), both with and without DPF. The animals (n = 7/treatment) were exposed in whole body exposure chambers. Animals breathing clean air were used as controls. Genotoxic effects of the lungs by the Comet assay, histological examination of lung tissue, bronchoalveolar lavage fluid (BALF) markers of pulmonary injury, and mRNA markers of inflammation and oxidative stress were analyzed. Our results showed that a minor number of genes related to inflammation were slightly differently expressed in the exposed animals compared to control. Histological analysis also revealed only minor effects on inflammatory tissue markers in the lungs, and this was supported by flow cytometry and ELISA analysis of cytokines in BALF. No exposure-related indications of genotoxicity were observed. Overall, exposure to DEE with or without DPF technology produced no adverse effects in the endpoints analyzed in the rat lung tissue or the BALF. Overall, exposure to DEE from a modern Euro 5 light vehicle engine run on B20 fuel with or without DPF technology produced no adverse effects in the endpoints analyzed in the rat lung tissue or the BALF.

  8. Short-term effects of ambient fine particulate matter pollution on hospital visits for chronic obstructive pulmonary disease in Beijing, China.

    Science.gov (United States)

    Tian, Yaohua; Xiang, Xiao; Juan, Juan; Song, Jing; Cao, Yaying; Huang, Chao; Li, Man; Hu, Yonghua

    2018-02-27

    Little is known about the effect of ambient fine particulate matter (PM 2.5 ) on chronic obstructive pulmonary disease (COPD) in China. The objective of this study was to explore the short-term effects of PM 2.5 on outpatient and inpatient visits for COPD in Beijing, China. A total of 3,503,313 outpatient visits and 126,982 inpatient visits for COPD between January 1, 2010, and June 30, 2012, were identified from the Beijing Medical Claim Data for Employees. A generalized additive Poisson model was applied to estimate the percentage change with 95% confidence interval (CI) in hospital visits for COPD in relation to an interquartile range (IQR) (90.8 μg/m 3 ) increase in PM 2.5 concentrations. Short-term exposure to PM 2.5 was significantly associated with increased use of COPD-related health services. There were clear exposure-response associations of PM 2.5 with COPD outpatient and inpatient visits. An IQR increase in the concurrent day PM 2.5 concentrations was significantly associated with a 2.38% (95% CI, 2.22%-2.53%) and 6.03% (95% CI, 5.19%-6.87%) increase in daily outpatient visits and inpatient visits, respectively. Elderly people were more sensitive to the adverse effects. The estimated risk was higher during the warm season compared to the cool season. Short-term exposure to PM 2.5 was associated with increased risk of hospital visits for COPD. Our findings contributed to the limited evidence concerning the effects of ambient PM 2.5 on COPD morbidity in developing countries.

  9. Effects of low or high doses of short wavelength ultraviolet light (UVB) on Langerhans cells and skin allograft survival

    International Nuclear Information System (INIS)

    Odling, K.A.; Halliday, G.M.; Muller, H.K.

    1987-01-01

    Donor C57BL mouse shaved dorsal trunk or tail skin was exposed to high (200 mJ/cm 2 ) or low (40 mJ/cm 2 ) doses of short wavelength ultraviolet light (UVB) before grafting on to the thorax of BALB/c mouse recipients of the same sex. Skin grafted 1-14 days following a single high dose of UVB irradiation was ultrastructurally depleted of LC and survived significantly longer than unirradiated skin before being rejected. After a 21-day interval between exposure and grafting when LC were again present in the epidermis there was no significant difference between treated and control graft survival. Exposure to low dose UVB irradiation only significantly increased graft survival for skin transplanted 1-3 days after irradiation; skin grafted 4 days following irradiation survived for a similar period to unirradiated control skin grafts. Electronmicroscopy showed that the low UVB dose did not deplete LC from the epidermis. We conclude that after low dose UVB treatment the class II MHC antigens on the LC Plasma membrane were lost temporarily, thus prolonging graft survival, but when the plasma membrane antigens were re-expressed graft survival returned to normal. In contrast, high-dose UVB irradiation prolonged graft survival by depleting LC from the epidermis, with graft survival only returning to control values as LC repopulated the epidermis

  10. Short-term effects on bone turnover of replacing milk with cola beverages: a 10-day interventional study in young men.

    Science.gov (United States)

    Kristensen, Mette; Jensen, Marlene; Kudsk, Jane; Henriksen, Marianne; Mølgaard, Christian

    2005-12-01

    In the Western world, increased consumption of carbonated soft drinks combined with a decreasing intake of milk may increase the risk of osteoporosis. This study was designed to reflect the trend of replacing milk with carbonated beverages in a group of young men on a low-calcium diet and studies the effects of this replacement on calcium homeostasis and bone turnover. This controlled crossover intervention study included 11 healthy men (22-29 years) who were given a low-calcium basic diet in two 10-day intervention periods with an intervening 10-day washout. During one period, they drank 2.5 l of Coca Cola per day and during the other period 2.5 l of semi-skimmed milk. Serum concentrations of calcium, phosphate, 25-hydroxycholecalciferol, 1,25-dihydroxycholecalciferol (1,25(OH)2D), osteocalcin, bone-specific alkaline phosphatase (B-ALP) and cross-linked C-telopeptides (CTX), plasma intact parathyroid hormone (PTH) and urinary cross-linked N-telopeptides (NTX) were determined at baseline and endpoint of each intervention period. An increase in serum phosphate (Pcola period compared to the milk period. Also, bone resorption was significantly increased following the cola period, seen as increased serum CTX (Pcola with a low-calcium diet induces increased bone turnover compared to a high intake of milk with a low-calcium diet. Thus, the trend towards a replacement of milk with cola and other soft drinks, which results in a low calcium intake, may negatively affect bone health as indicated by this short-term study.

  11. Impact of repeated exposure on toxicity of perchloroethylene in Swiss Webster mice

    International Nuclear Information System (INIS)

    Philip, Binu K.; Mumtaz, Moiz M.; Latendresse, John R.; Mehendale, Harihara M.

    2007-01-01

    The aim was to study the subchronic toxicity of perchloroethylene (Perc) by measuring injury and repair in liver and kidney in relation to disposition of Perc and its major metabolites. Male SW mice (25-29 g) were given three dose levels of Perc (150, 500, and 1000 mg/kg day) via aqueous gavage for 30 days. Tissue injury was measured during the dosing regimen (0, 1, 7, 14, and 30 days) and over a time course of 24-96 h after the last dose (30 days). Perc produced significant liver injury (ALT) after single day exposure to all three doses. Liver injury was mild to moderate and regressed following repeated exposure for 30 days. Subchronic Perc exposure induced neither kidney injury nor dysfunction during the entire time course as evidenced by normal renal histology and BUN. TCA was the major metabolite detected in blood, liver, and kidney. Traces of DCA were also detected in blood at initial time points after single day exposure. With single day exposure, metabolism of Perc to TCA was saturated with all three doses. AUC/dose ratio for TCA was significantly decreased with a concomitant increase in AUC/dose of Perc levels in liver and kidney after 30 days as compared to 1 day exposures, indicating inhibition of metabolism upon repeated exposure to Perc. Hepatic CYP2E1 expression and activity were unchanged indicating that CYP2E1 is not the critical enzyme inhibited. Hepatic CYP4A expression, measured as a marker of peroxisome proliferation was increased transiently only on day 7 with the high dose, but was unchanged at later time points. Liver tissue repair peaked at 7 days, with all three doses and was sustained after medium and high dose exposure for 14 days. These data indicate that subchronic Perc exposure via aqueous gavage does not induce nephrotoxicity and sustained hepatotoxicity suggesting adaptive hepatic repair mechanisms. Enzymes other than CYP2E1, involved in the metabolism of Perc may play a critical role in the metabolism of Perc upon subchronic exposure

  12. Is the association between short stature and myocardial infarction explained by childhood exposures--a population-based case referent study (SHEEP)

    DEFF Research Database (Denmark)

    Lundberg, Michael; Diderichsen, Finn; Hallqvist, Johan

    2002-01-01

    AIMS: This study was undertaken to examine the association between short stature and acute non-fatal myocardial infarction and to analyse causal mechanisms related to height with a focus on childhood risk factors. METHOD: The SHEEP (Stockholm Heart Epidemiology Program) is a population-based case......-referent study. The outcome was incident first events of myocardial infarction. The study base included all Swedish citizens aged 45 to 70, who lived in Stockholm County during 1992-94. This analysis is based on 967 male cases, 412 female cases and 1696 referents. Exposure information was obtained through...... questionnaires, interviews, health examinations, and obstetric records. RESULTS: Adult height was inversely related to myocardial infarction. The odds ratio for men in the shortest quartile (

  13. Ciproxifan, an H3 receptor antagonist, improves short-term recognition memory impaired by isoflurane anesthesia.

    Science.gov (United States)

    Ding, Fang; Zheng, Limin; Liu, Min; Chen, Rongfa; Leung, L Stan; Luo, Tao

    2016-08-01

    Exposure to volatile anesthetics has been reported to cause temporary or sustained impairments in learning and memory in pre-clinical studies. The selective antagonists of the histamine H3 receptors (H3R) are considered to be a promising group of novel therapeutic agents for the treatment of cognitive disorders. The aim of this study was to evaluate the effect of H3R antagonist ciproxifan on isoflurane-induced deficits in an object recognition task. Adult C57BL/6 J mice were exposed to isoflurane (1.3 %) or vehicle gas for 2 h. The object recognition tests were carried at 24 h or 7 days after exposure to anesthesia to exploit the tendency of mice to prefer exploring novel objects in an environment when a familiar object is also present. During the training phase, two identical objects were placed in two defined sites of the chamber. During the test phase, performed 1 or 24 h after the training phase, one of the objects was replaced by a new object with a different shape. The time spent exploring each object was recorded. A robust deficit in object recognition memory occurred 1 day after exposure to isoflurane anesthesia. Isoflurane-treated mice spent significantly less time exploring a novel object at 1 h but not at 24 h after the training phase. The deficit in short-term memory was reversed by the administration of ciproxifan 30 min before behavioral training. Isoflurane exposure induces reversible deficits in object recognition memory. Ciproxifan appears to be a potential therapeutic agent for improving post-anesthesia cognitive memory performance.

  14. Short-Term fo F2 Forecast: Present Day State of Art

    Science.gov (United States)

    Mikhailov, A. V.; Depuev, V. H.; Depueva, A. H.

    An analysis of the F2-layer short-term forecast problem has been done. Both objective and methodological problems prevent us from a deliberate F2-layer forecast issuing at present. An empirical approach based on statistical methods may be recommended for practical use. A forecast method based on a new aeronomic index (a proxy) AI has been proposed and tested over selected 64 severe storm events. The method provides an acceptable prediction accuracy both for strongly disturbed and quiet conditions. The problems with the prediction of the F2-layer quiet-time disturbances as well as some other unsolved problems are discussed

  15. Autophagy-associated atrophy and metabolic remodeling of the mouse diaphragm after short-term intermittent hypoxia.

    Directory of Open Access Journals (Sweden)

    Christian Giordano

    Full Text Available Short-term intermittent hypoxia (IH is common in patients with acute respiratory disorders. Although prolonged exposure to hypoxia induces atrophy and increased fatigability of skeletal muscle, the response to short-term IH is less well known. We hypothesized that the diaphragm and limb muscles would adapt differently to short-term IH given that hypoxia stimulates ventilation and triggers a superimposed exercise stimulus in the diaphragm.We determined the structural, metabolic, and contractile properties of the mouse diaphragm after 4 days of IH (8 hours per day, 30 episodes per hour to a FiO2 nadir=6%, and compared responses in the diaphragm to a commonly studied reference limb muscle, the tibialis anterior. Outcome measures included muscle fiber size, assays of muscle proteolysis (calpain, ubiquitin-proteasome, and autophagy pathways, markers of oxidative stress and mitochondrial function, quantification of intramyocellular lipid and lipid metabolism genes, type I myosin heavy chain (MyHC expression, and in vitro contractile properties.After 4 days of IH, the diaphragm alone demonstrated significant atrophy (30% decrease of myofiber size together with increased LC3B-II protein (2.4-fold and mRNA markers of the autophagy pathway (LC3B, Gabarapl1, Bnip3, whereas active calpain and E3 ubiquitin ligases (MuRF1, atrogin-1 were unaffected in both muscles. Succinate dehydrogenase activity was significantly reduced by IH in both muscles. However, only the diaphragm exhibited increased intramyocellular lipid droplets (2.5-fold after IH, along with upregulation of genes linked to activated lipid metabolism. In addition, although the diaphragm showed evidence for acute fatigue immediately following IH, it underwent an adaptive fiber type switch toward slow type I MyHC-expressing fibers, associated with greater intrinsic endurance of the muscle during repetitive stimulation in vitro.Short-term IH induces preferential atrophy in the mouse diaphragm

  16. The effects of short- and long-term air pollutants on plant phenology and leaf characteristics

    International Nuclear Information System (INIS)

    Jochner, Susanne; Markevych, Iana; Beck, Isabelle; Traidl-Hoffmann, Claudia

    2015-01-01

    Pollution adversely affects vegetation; however, its impact on phenology and leaf morphology is not satisfactorily understood yet. We analyzed associations between pollutants and phenological data of birch, hazel and horse chestnut in Munich (2010) along with the suitability of leaf morphological parameters of birch for monitoring air pollution using two datasets: cumulated atmospheric concentrations of nitrogen dioxide and ozone derived from passive sampling (short-term exposure) and pollutant information derived from Land Use Regression models (long-term exposure). Partial correlations and stepwise regressions revealed that increased ozone (birch, horse chestnut), NO_2, NO_x and PM levels (hazel) were significantly related to delays in phenology. Correlations were especially high when rural sites were excluded suggesting a better estimation of long-term within-city pollution. In situ measurements of foliar characteristics of birch were not suitable for bio-monitoring pollution. Inconsistencies between long- and short-term exposure effects suggest some caution when interpreting short-term data collected within field studies. - Highlights: • We present results of a field survey examining pollution effects on vegetation. • Particularly ozone was significantly associated with delays in spring phenology. • Leaf morphology of birch was found to be inadequate for bio-monitoring pollution. • Inconsistencies between long-/short-term exposure effects suggest caution. - Pollutants were significantly associated with delays in spring phenology. However, inconsistencies between long- and short-term exposure effects suggest some caution when interpreting results.

  17. A proposal for assessing study quality: Biomonitoring, Environmental Epidemiology, and Short-lived Chemicals (BEES-C) instrument

    Science.gov (United States)

    LaKind, Judy S.; Sobus, Jon R.; Goodman, Michael; Barr, Dana Boyd; Fürst, Peter; Albertini, Richard J.; Arbuckle, Tye E.; Schoeters, Greet; Tan, Yu-Mei; Teeguarden, Justin; Tornero-Velez, Rogelio; Weisel, Clifford P.

    2015-01-01

    The quality of exposure assessment is a major determinant of the overall quality of any environmental epidemiology study. The use of biomonitoring as a tool for assessing exposure to ubiquitous chemicals with short physiologic half-lives began relatively recently. These chemicals present several challenges, including their presence in analytical laboratories and sampling equipment, difficulty in establishing temporal order in cross-sectional studies, short- and long-term variability in exposures and biomarker concentrations, and a paucity of information on the number of measurements required for proper exposure classification. To date, the scientific community has not developed a set of systematic guidelines for designing, implementing and interpreting studies of short-lived chemicals that use biomonitoring as the exposure metric or for evaluating the quality of this type of research for WOE assessments or for peer review of grants or publications. We describe key issues that affect epidemiology studies using biomonitoring data on short-lived chemicals and propose a systematic instrument – the Biomonitoring, Environmental Epidemiology, and Short-lived Chemicals (BEES-C) instrument – for evaluating the quality of research proposals and studies that incorporate biomonitoring data on short-lived chemicals. Quality criteria for three areas considered fundamental to the evaluation of epidemiology studies that include biological measurements of short-lived chemicals are described: 1) biomarker selection and measurement, 2) study design and execution, and 3) general epidemiological study design considerations. We recognize that the development of an evaluative tool such as BEES-C is neither simple nor non-controversial. We hope and anticipate that the instrument will initiate further discussion/debate on this topic. PMID:25137624

  18. Short-term stress enhances cellular immunity and increases early resistance to squamous cell carcinoma.

    Science.gov (United States)

    Dhabhar, Firdaus S; Saul, Alison N; Daugherty, Christine; Holmes, Tyson H; Bouley, Donna M; Oberyszyn, Tatiana M

    2010-01-01

    In contrast to chronic/long-term stress that suppresses/dysregulates immune function, an acute/short-term fight-or-flight stress response experienced during immune activation can enhance innate and adaptive immunity. Moderate ultraviolet-B (UV) exposure provides a non-invasive system for studying the naturalistic emergence, progression and regression of squamous cell carcinoma (SCC). Because SCC is an immunoresponsive cancer, we hypothesized that short-term stress experienced before UV exposure would enhance protective immunity and increase resistance to SCC. Control and short-term stress groups were treated identically except that the short-term stress group was restrained (2.5h) before each of nine UV-exposure sessions (minimum erythemal dose, 3-times/week) during weeks 4-6 of the 10-week UV exposure protocol. Tumors were measured weekly, and tissue collected at weeks 7, 20, and 32. Chemokine and cytokine gene expression was quantified by real-time PCR, and CD4+ and CD8+ T cells by flow cytometry and immunohistochemistry. Compared to controls, the short-term stress group showed greater cutaneous T-cell attracting chemokine (CTACK)/CCL27, RANTES, IL-12, and IFN-gamma gene expression at weeks 7, 20, and 32, higher skin infiltrating T cell numbers (weeks 7 and 20), lower tumor incidence (weeks 11-20) and fewer tumors (weeks 11-26). These results suggest that activation of short-term stress physiology increased chemokine expression and T cell trafficking and/or function during/following UV exposure, and enhanced Type 1 cytokine-driven cell-mediated immunity that is crucial for resistance to SCC. Therefore, the physiological fight-or-flight stress response and its adjuvant-like immuno-enhancing effects, may provide a novel and important mechanism for enhancing immune system mediated tumor-detection/elimination that merits further investigation.

  19. Low-exposure tritium radiotoxicity in mammals

    International Nuclear Information System (INIS)

    Dobson, R.L.

    1982-01-01

    A special feature of tritium radiation is the very low energy of the beta particles (5.7 keV average, 18 keV maximum). This low energy results in very short particle ranges in tissue, ranges that are less than cell dimensions. Another result of the low energy is that the ionization density along beta-ray tracks (even though the tracks are short) is significantly greater than that associated with secondary electrons from gamma rays. The studies of tritium radiotoxicity reviewed, involving chronic 3 HOH exposures in mammals, demonstrate in both mice and monkeys that biological effects can be measured following remarkably low levels of exposure --- levels in the range of serious practical interest to radiation protection. (Namekawa, K.)

  20. Effect of head-only sub-chronic GSM exposure on spatial memory of rats

    International Nuclear Information System (INIS)

    Ammari, Mohamed; Brillaud, Elsa; Lecomte, Anthony; Sakly, Mohsen; Abdelmelek, Hafedh; Seze, Rene de; Faculte des Sciences de Bizerte, Jarzouna

    2008-01-01

    Full text: Introduction: Low power electromagnetic fields (EMF) are suspected to produce deficit memory in rats. The study of Dubreuil et al (2003) showed that a short-term (10-15 days) exposure 'head-only' to GSM 900 MHz radio frequencies does not produce a deficit memory in adult rats. The aim of our experiment was to determine if head-only sub-chronic exposure (2 months) of rats to GSM signal for 45 min at a SAR = 1.5 W/Kg and for 15 min at 6 W/Kg induce deficit in spatial memory of rats in radial maze test. Materials and methods: Exposure system: Animals were placed in Plexiglas rockets with an individual loop antenna placed above the rat's head. Four animals were exposed at the time. Loop antennas were connected to a generator and emitted a GSM signal (900 MHz, pulsed at 217 Hz, 1/8 duty factor) 5 days / week for 8 weeks. Experimental group: 30 Sprague-Dawley male rats were randomly assigned to 5 different groups: a) 6 rats exposed 15 min at SAR = 6 W/Kg; b) 6 rats exposed 45 min at SAR = 1.5 W/g; c) 6 rats sham controls (3 for 5 min and 3 for 45 min, SAR = 0 W/Kg); d) 6 rats without any treatment and manipulation (cage control); e) 6 rats were injected (i.p) S.B.H 0.1 mg/Kg (Sigma Aldrich) as positive control group. Behavioural procedure: The radial maze protocol consists of two consecutive phases: the training task (10 days) and the test task (8 days). In the first phase, rats were trained to visit the 8 arms of the maze without returning to an arm already visited. In the second phase (8 days), a 45-min intra-trial delay was introduced after four visited arms. After the intra-delay, the rat was placed in the maze to finish the test task, which is visiting four other arms he had not visited. During the training task, exposure took place before the behavioural task. During the test task, exposure or sham-exposure took place during the intra-delay. Results and discussion: In all experiments, performance of exposed rats (1.5 and 6 W/Kg) was compared with that of

  1. Predicting sleep quality from stress and prior sleep--a study of day-to-day covariation across six weeks.

    Science.gov (United States)

    Åkerstedt, Torbjörn; Orsini, Nicola; Petersen, Helena; Axelsson, John; Lekander, Mats; Kecklund, Göran

    2012-06-01

    The connection between stress and sleep is well established in cross-sectional questionnaire studies and in a few prospective studies. Here, the intention was to study the link between stress and sleep on a day-to-day basis across 42 days. Fifty participants kept a sleep/wake diary across 42 days and responded to daily questions on sleep and stress. The results were analyzed with a mixed model approach using stress during the prior day to predict morning ratings of sleep quality. The results showed that bedtime stress and worries were the main predictors of sleep quality, but that, also, late awakening, short prior sleep, high quality of prior sleep, and good health the prior day predicted higher sleep quality. Stress during the day predicts subsequent sleep quality on a day-to-day basis across 42 days. The observed range of variation in stress/worries was modest, which is why it is suggested that the present data underestimates the impact of stress on subsequent sleep quality. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Temporal variability of daily personal magnetic field exposure metrics in pregnant women.

    Science.gov (United States)

    Lewis, Ryan C; Evenson, Kelly R; Savitz, David A; Meeker, John D

    2015-01-01

    Recent epidemiology studies of power-frequency magnetic fields and reproductive health have characterized exposures using data collected from personal exposure monitors over a single day, possibly resulting in exposure misclassification due to temporal variability in daily personal magnetic field exposure metrics, but relevant data in adults are limited. We assessed the temporal variability of daily central tendency (time-weighted average, median) and peak (upper percentiles, maximum) personal magnetic field exposure metrics over 7 consecutive days in 100 pregnant women. When exposure was modeled as a continuous variable, central tendency metrics had substantial reliability, whereas peak metrics had fair (maximum) to moderate (upper percentiles) reliability. The predictive ability of a single-day metric to accurately classify participants into exposure categories based on a weeklong metric depended on the selected exposure threshold, with sensitivity decreasing with increasing exposure threshold. Consistent with the continuous measures analysis, sensitivity was higher for central tendency metrics than for peak metrics. If there is interest in peak metrics, more than 1 day of measurement is needed over the window of disease susceptibility to minimize measurement error, but 1 day may be sufficient for central tendency metrics.

  3. Assessment of short/long term electric field strength measurements for a pilot district

    Science.gov (United States)

    Kurnaz, Cetin; Yildiz, Dogan; Karagol, Serap

    2018-03-01

    The level of electromagnetic radiation (EMR) exposure increases day by day as natural consequences of technological developments. In recent years, the increasing use of cellular systems has made it necessary to measure and evaluate EMR originating from base stations. In this study, broadband and band selective electric field strength (E) measurements were taken at four different times in order to evaluate the change of short term E in Atakum district of Samsun, Turkey. The measurements were collected from 46 different locations using a SRM 3006 and a PMM 8053 EMR meter in a band from 100 kHz to 3 GHz, and the maximum E (Emax) and the average E (Eavg) were recorded. The highest values have been noticed in these measurements at 9.45 V/m and 17.53 V/m for Eavg and Emax respectively. Apart from these measurements, 24 hour long term E measurements were taken at a location where the highest value was observed and analyzed, to observe the change of Es during a day. At the end of the study, a tentative mathematical model that helps in computing the total E of the medium with 95% accuracy, was obtained.

  4. Effects of Adult Day Care on Daily Stress of Caregivers: A Within-Person Approach

    Science.gov (United States)

    Kim, Kyungmin; Femia, Elia E.; Almeida, David M.; Savla, Jyoti; Molenaar, Peter C. M.

    2011-01-01

    Objectives. This article examined exposure to and appraisal of care-related stressors associated with use of adult day services (ADS) by family caregivers of individuals with dementia. Methods. Using a within-person withdrawal design (A-B-A-B), we compared caregivers’ exposure to and appraisal of behavior problems on days their relative attended and did not attend ADS. Participants were 121 family caregivers enrolling a relative with dementia in an ADS program. Daily assessments were obtained prior to the person's attending ADS for the first time and after 1 and 2 months of attendance on days the person attended and did not attend ADS. Results. Total exposure to stressors and stress appraisals decreased significantly over time on ADS days compared with non-ADS days. Most of this difference was accounted by the time the person with dementia was away from the caregiver, but there were also significant reductions in behavioral problems during the evening and improved sleep immediately following ADS use. Discussion. ADS use lowered caregivers’ exposure to stressors and may improve behavior and sleep for people with dementia on days they have ADS. The study highlights how a within-person design can identify the effects of an intermittent intervention, such as ADS. PMID:21642593

  5. Short-term exposure to dimethylformamide and the impact on digestive system disease: an outdoor study for volatile organic compound.

    Science.gov (United States)

    Wang, Cui; Huang, Canke; Wei, Yumei; Zhu, Qi; Tian, Weili; Zhang, Qingyu

    2014-07-01

    Occupational and experimental studies have revealed the organs most affected by dimethylformamide (DMF) are liver and gastrointestinal tract. However, few studies have focused on the potential effect of outdoor pollution of DMF. This study examined the health risk of hospitalization due to digestive system disease by time series studies in a case city Longwan, China. The urine metabolite of DMF was correlated well with DMF exposure concentration (EC). A 101.0-μg/m(3) (interquartile range) increase in the two-day moving average of DMF EC was associated with a 1.10 (1.01 ˜ 1.20), 1.22 (1.10 ˜ 1.35), and 1.05 (0.90 ˜ 1.22) increase in hospitalization for total digestive system diseases, liver disease, and gastrointestinal tract disease, respectively. The exposure-dose response between DMF and the relative risk of liver disease was linear only below 350 μg/m(3). These findings highlight a previously unrecognized health problem related to VOCs released into the outdoor environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. The effect of three different (-135°C whole body cryotherapy exposure durations on elite rugby league players.

    Directory of Open Access Journals (Sweden)

    James Selfe

    Full Text Available BACKGROUND: Whole body cryotherapy (WBC is the therapeutic application of extreme cold air for a short duration. Minimal evidence is available for determining optimal exposure time. PURPOSE: To explore whether the length of WBC exposure induces differential changes in inflammatory markers, tissue oxygenation, skin and core temperature, thermal sensation and comfort. METHOD: This study was a randomised cross over design with participants acting as their own control. Fourteen male professional first team super league rugby players were exposed to 1, 2, and 3 minutes of WBC at -135°C. Testing took place the day after a competitive league fixture, each exposure separated by seven days. RESULTS: No significant changes were found in the inflammatory cytokine interleukin six. Significant reductions (p<0.05 in deoxyhaemoglobin for gastrocnemius and vastus lateralis were found. In vastus lateralis significant reductions (p<0.05 in oxyhaemoglobin and tissue oxygenation index (p<0.05 were demonstrated. Significant reductions (p<0.05 in skin temperature were recorded. No significant changes were recorded in core temperature. Significant reductions (p<0.05 in thermal sensation and comfort were recorded. CONCLUSION: Three brief exposures to WBC separated by 1 week are not sufficient to induce physiological changes in IL-6 or core temperature. There are however significant changes in tissue oxyhaemoglobin, deoxyhaemoglobin, tissue oxygenation index, skin temperature and thermal sensation. We conclude that a 2 minute WBC exposure was the optimum exposure length at temperatures of -135°C and could be applied as the basis for future studies.

  7. Short Lived Fission Product Yield Measurements in 235U, 238U and 239Pu

    Science.gov (United States)

    Silano, Jack; Tonchev, Anton; Tornow, Werner; Krishichayan, Fnu; Finch, Sean; Gooden, Matthew; Wilhelmy, Jerry

    2017-09-01

    Yields of short lived fission products (FPYs) with half lives of a few minutes to an hour contain a wealth of information about the fission process. Knowledge of short lived FPYs would contribute to existing data on longer lived FPY mass and charge distributions. Of particular interest are the relative yields between the ground states and isomeric states of FPYs since these isomeric ratios can be used to determine the angular momentum of the fragments. Over the past five years, a LLNL-TUNL-LANL collaboration has made precision measurements of FPYs from quasi-monoenergetic neutron induced fission of 235U, 238U and 239Pu. These efforts focused on longer lived FPYs, using a well characterized dual fission chamber and several days of neutron beam exposure. For the first time, this established technique will be applied to measuring short lived FPYs, with half lives of minutes to less than an hour. A feasibility study will be performed using irradiation times of < 1 hour, improving the sensitivity to short lived FPYs by limiting the buildup of long lived isotopes. Results from this exploratory study will be presented, and the implications for isomeric ratio measurements will be discussed. This work was performed under the auspices of US DOE by LLNL under Contract DE-AC52-07NA27344.

  8. Years of life lost due to external radiation exposure

    International Nuclear Information System (INIS)

    Raicevic, J.J.; Merkle, J.M.; Ehrhardt, J.; Ninkovic, M.M.

    2002-01-01

    A new approach for calculation of the years of life lost per excess death (YLL) due to stochastic health effects is applied to external exposure pathways. The short-term external exposures are due to the passage of radioactive cloud (CL) and due to the skin and clothes contamination (SK). The long-term external exposure is the one from the radioactive material deposited on ground (GR). Three nuclides, 131 I , 137 Cs and 239 Pu with extremely wide range of the half-life are considered to examine its possible influence on the calculated YLL values. For each of these nuclides, the YLL is found as a decreasing function of the age at exposure and presented graphically in this paper. Another negative correlation is established between the fully averaged YLL and the duration of the nuclide's half-life has been found for protracted exposure (GR). On the other hand, the YLL for the short-term external exposures (CL and SK) practically does not depend on the nuclide's half-life. In addition, a weak YLL dependence of the dose was commented. (author)

  9. Tuberculosis Facts - Exposure to TB

    Science.gov (United States)

    Tuberculosis (TB) Facts Exposure to TB What is TB? “TB” is short for a disease called tuberculosis. TB is spread through the air from one ... Viral Hepatitis, STD, and TB Prevention Division of Tuberculosis Elimination

  10. Behavioral and endocrine consequences of simultaneous exposure to two different stressors in rats: interaction or independence?

    Directory of Open Access Journals (Sweden)

    Cristina Muñoz-Abellán

    Full Text Available Although behavioral and endocrine consequences of acute exposure to stressors have been extensively studied, little is known about how simultaneous exposure to two different stressors interacts to induce short- and long-term effects. In the present experiment we studied this interaction in adult male rats exposed to cat fur odor (impregnated cloth or immobilization on boards either separately or simultaneously. We reasoned that exposure to the odor of a potential predator while immobilized, may potentiate its negative consequences as compared to exposure to only one of the stressors. Exposure to cat odor elicited the expected reduction of activity and avoidance of the area where the impregnated cloth was located. The endocrine response (plasma levels of ACTH and corticosterone, as a measure of the hypothalamic-pituitary-adrenal axis, HPA was markedly greater after immobilization than after cat fur odor and no additive effects were found by simultaneous exposure to both stressors. Cat odor, but not immobilization, increased anxiety-like behavior as evaluated in the elevated plus-maze 7 days after the stressors, with no evidence of enhanced HPA activation. In addition, cat odor exposure resulted in long-lasting (8 days later fear conditioning to the box containing a clean cloth, which was reflected by hypoactivity, avoidance of the cloth area and enhanced HPA activation. All these effects were similarly observed in rats exposed simultaneously to cat odor and immobilization. In rats only exposed to immobilization, only some weak behavioral signs of fear conditioning were found, but HPA activation in response to the context paired to immobilization was enhanced to the same extent as in cat odor-exposed animals, supporting a certain degree of endocrine conditioning. The present results did not reveal important behavioral interactions between the two stressors when animals experienced both simultaneously, whereas some interactions were found regarding

  11. Behavioral and endocrine consequences of simultaneous exposure to two different stressors in rats: interaction or independence?

    Science.gov (United States)

    Muñoz-Abellán, Cristina; Rabasa, Cristina; Daviu, Nuria; Nadal, Roser; Armario, Antonio

    2011-01-01

    Although behavioral and endocrine consequences of acute exposure to stressors have been extensively studied, little is known about how simultaneous exposure to two different stressors interacts to induce short- and long-term effects. In the present experiment we studied this interaction in adult male rats exposed to cat fur odor (impregnated cloth) or immobilization on boards either separately or simultaneously. We reasoned that exposure to the odor of a potential predator while immobilized, may potentiate its negative consequences as compared to exposure to only one of the stressors. Exposure to cat odor elicited the expected reduction of activity and avoidance of the area where the impregnated cloth was located. The endocrine response (plasma levels of ACTH and corticosterone, as a measure of the hypothalamic-pituitary-adrenal axis, HPA) was markedly greater after immobilization than after cat fur odor and no additive effects were found by simultaneous exposure to both stressors. Cat odor, but not immobilization, increased anxiety-like behavior as evaluated in the elevated plus-maze 7 days after the stressors, with no evidence of enhanced HPA activation. In addition, cat odor exposure resulted in long-lasting (8 days later) fear conditioning to the box containing a clean cloth, which was reflected by hypoactivity, avoidance of the cloth area and enhanced HPA activation. All these effects were similarly observed in rats exposed simultaneously to cat odor and immobilization. In rats only exposed to immobilization, only some weak behavioral signs of fear conditioning were found, but HPA activation in response to the context paired to immobilization was enhanced to the same extent as in cat odor-exposed animals, supporting a certain degree of endocrine conditioning. The present results did not reveal important behavioral interactions between the two stressors when animals experienced both simultaneously, whereas some interactions were found regarding HPA activation

  12. Behavioral and Endocrine Consequences of Simultaneous Exposure to Two Different Stressors in Rats: Interaction or Independence?

    Science.gov (United States)

    Muñoz-Abellán, Cristina; Rabasa, Cristina; Daviu, Nuria; Nadal, Roser; Armario, Antonio

    2011-01-01

    Although behavioral and endocrine consequences of acute exposure to stressors have been extensively studied, little is known about how simultaneous exposure to two different stressors interacts to induce short- and long-term effects. In the present experiment we studied this interaction in adult male rats exposed to cat fur odor (impregnated cloth) or immobilization on boards either separately or simultaneously. We reasoned that exposure to the odor of a potential predator while immobilized, may potentiate its negative consequences as compared to exposure to only one of the stressors. Exposure to cat odor elicited the expected reduction of activity and avoidance of the area where the impregnated cloth was located. The endocrine response (plasma levels of ACTH and corticosterone, as a measure of the hypothalamic-pituitary-adrenal axis, HPA) was markedly greater after immobilization than after cat fur odor and no additive effects were found by simultaneous exposure to both stressors. Cat odor, but not immobilization, increased anxiety-like behavior as evaluated in the elevated plus-maze 7 days after the stressors, with no evidence of enhanced HPA activation. In addition, cat odor exposure resulted in long-lasting (8 days later) fear conditioning to the box containing a clean cloth, which was reflected by hypoactivity, avoidance of the cloth area and enhanced HPA activation. All these effects were similarly observed in rats exposed simultaneously to cat odor and immobilization. In rats only exposed to immobilization, only some weak behavioral signs of fear conditioning were found, but HPA activation in response to the context paired to immobilization was enhanced to the same extent as in cat odor-exposed animals, supporting a certain degree of endocrine conditioning. The present results did not reveal important behavioral interactions between the two stressors when animals experienced both simultaneously, whereas some interactions were found regarding HPA activation

  13. The effect of day-neutral mutations in barley and wheat on the interaction between photoperiod and vernalization.

    Science.gov (United States)

    Turner, Adrian S; Faure, Sébastien; Zhang, Yang; Laurie, David A

    2013-09-01

    Vernalization-2 (Vrn-2) is the major flowering repressor in temperate cereals. It is only expressed under long days in wild-type plants. We used two day-neutral (photoperiod insensitive) mutations that allow rapid flowering in short or long days to investigate the day length control of Vrn-2. The barley (Hordeum vulgare) early maturity8 (eam8) mutation affects the barley ELF3 gene. eam8 mutants disrupt the circadian clock resulting in elevated expression of Ppd-H1 and the floral activator HvFT1 under short or long days. When eam8 was crossed into a genetic background with a vernalization requirement Vrn-2 was expressed under all photoperiods and the early flowering phenotype was partially repressed in unvernalized (UV) plants, likely due to competition between the constitutively active photoperiod pathway and the repressing effect of Vrn-2. We also investigated the wheat (Triticum aestivum) Ppd-D1a mutation. This differs from eam8 in causing elevated levels of Ppd-1 and TaFT1 expression without affecting the circadian clock. We used genotypes that differed in "short-day vernalization". Short days were effective in promoting flowering in individuals wild type at Ppd-D1, but not in individuals that carry the Ppd-D1a mutation. The latter showed Vrn-2 expression in short days. In summary, eam8 and Ppd-D1a mimic long days in terms of photoperiod response, causing Vrn-2 to become aberrantly expressed (in short days). As Ppd-D1a does not affect the circadian clock, this also shows that clock regulation of Vrn-2 operates indirectly through one or more downstream genes, one of which may be Ppd-1.

  14. Using serology to assist with complicated post-exposure prophylaxis for rabies and Australian bat lyssavirus.

    Science.gov (United States)

    Conroy, Niall; Vlack, Susan; Williams, Julian M; Patten, John J; Horvath, Robert L; Lambert, Stephen B

    2013-01-01

    Australia uses a protocol combining human rabies immunoglobulin (HRIG) and rabies vaccine for post-exposure prophylaxis (PEP) of rabies and Australian bat lyssavirus (ABLV), with the aim of achieving an antibody titre of ≥0.5 IU/ml, as per World Health Organization (WHO) guidelines, as soon as possible. We present the course of PEP administration and serological testing for four men with complex requirements. Following dog bites in Thailand, two men (62 years old, 25 years old) received no HRIG and had delayed vaccine courses: 23 days between dose two and three, and 18 days between dose one and two, respectively. Both seroconverted following dose four. Another 62-year-old male, who was HIV-positive (normal CD4 count), also suffered a dog bite and had delayed care receiving i.m. rabies vaccine on days six and nine in Thailand. Back in Australia, he received three single and one double dose i.m. vaccines followed by another double dose of vaccine, delivered intradermally and subcutaneously, before seroconverting. A 23-year-old male with a history of allergies received simultaneous HRIG and vaccine following potential ABLV exposure, and developed rash, facial oedema and throat tingling, which was treated with a parenteral antihistamine and tapering dose of steroids. Serology showed he seroconverted following dose four. These cases show that PEP can be complicated by exposures in tourist settings where reliable prophylaxis may not be available, where treatment is delayed or deviates from World Health Organization recommendations. Due to the potentially short incubation time of rabies/ABLV, timely prophylaxis after a potential exposure is needed to ensure a prompt and adequate immune response, particularly in patients who are immune-suppressed or who have not received HRIG. Serology should be used to confirm an adequate response to PEP when treatment is delayed or where a concurrent immunosuppressing medical condition or therapy exists.

  15. Mean rate of DNA replication and replicon size in the shoot apex of Silence coeli-rosa. During the initial 120 minutes of the first day of floral induction

    International Nuclear Information System (INIS)

    Ormrod, J.C.; Francis, D.

    1986-01-01

    28-day-old plants of Silence coeli-rosa were exposed, at 1700 hours, to long day (LD) conditions comprising light of low fluence rate provided by tungsten bulbs, or maintained in darkness as short day (SD) controls. All plants were exposed at 1700 hours to tritiated-(methyl- 3 H)-thymidine for 30, 45, 60, 90, or 120 minutes. Apical domes were isolated and prepared as fiber autoradiographs from which replicon size and rates of DNA replication, per single replication fork were recorded. In SD, replicon size was between 15-20 μm and exposure to LD conditions altered neither replicon size nor the pattern of deployment of replicons during S-phase relative to the SD controls. However, the mean rate of replication in LD was 8.7 μm h -1 compared with 5.2 μm h -1 in SD. Thus, exposure to LD resulted in a 1.7-fold increase in the rate of DNA replication relative to the SD controls. This rapid increase in replication rate, detectable within 30 minutes of the start of the LD is discussed in relation to changes known to occur to the cell cycle in Silene during the first day of floral induction. (Author)

  16. Association of Short-Term Exposure to Ambient Fine Particulate Matter with Skin Symptoms in Schoolchildren: A Panel Study in a Rural Area of Western Japan

    Directory of Open Access Journals (Sweden)

    Masanari Watanabe

    2017-03-01

    Full Text Available Numerous studies have unmasked the deleterious effects of particulate matter less than 2.5 μm (PM2.5 on health. However, epidemiologic evidence focusing on the effects of PM2.5 on skin health remains limited. An important aspect of Asian dust (AD in relationship to health is the amount of PM2.5 contained therein. Several studies have demonstrated that AD can aggravate skin symptoms. The current study aimed to investigate the effects of short-term exposure to PM2.5 and AD particles on skin symptoms in schoolchildren. A total of 339 children recorded daily skin symptom scores during February 2015. Light detection and ranging were used to calculate AD particle size. Generalized estimating equation logistic regression analyses were used to estimate the associations among skin symptoms and the daily levels of PM2.5 and AD particles. Increases in the levels of PM2.5 and AD particles were not related to an increased risk of skin symptom events, with increases of 10.1 μg/m3 in PM2.5 and 0.01 km−1 in AD particles changing odds ratios by 1.03 and 0.99, respectively. These results suggest that short-term exposure to PM2.5 and AD does not impact skin symptoms in schoolchildren.

  17. Chronic obstructive pulmonary disease and long-term exposure to traffic-related air pollution: a cohort study

    DEFF Research Database (Denmark)

    Andersen, Zorana J; Hvidberg, Martin; Jensen, Steen S

    2011-01-01

    Short-term exposure to air pollution has been associated with exacerbation of chronic obstructive pulmonary disease (COPD), whereas the role of long-term exposures on the development of COPD is not yet fully understood.......Short-term exposure to air pollution has been associated with exacerbation of chronic obstructive pulmonary disease (COPD), whereas the role of long-term exposures on the development of COPD is not yet fully understood....

  18. Aircrew radiation exposure: sources-risks-measurement

    International Nuclear Information System (INIS)

    Duftschmid, K.E.

    1994-05-01

    A short review is given on the actual aircrew exposure and its sources. The resulting risks for harmful effects to the health and discuss methods for in-flight measurements of exposure is evaluated. An idea for a fairly simple and economic approach to a practical, airborne active dosimeter for the assessment of individual crew exposure is presented. The exposure of civil aircrew to cosmic radiation, should not be considered a tremendous risk to the health, there is no reason for panic. However, being significantly higher than the average exposure to radiation workers, it can certainly not be neglected. As recommended by ICRP, aircrew exposure has to be considered occupational radiation exposure and aircrews are certainly entitled to the same degree of protection, as other ground-based radiation workers have obtained by law, since long time. (author)

  19. Effects of Acutely Intermittent Hypoxic Exposure on Running Economy and Physical Performance in Basketball Players.

    Science.gov (United States)

    Kilding, Andrew E; Dobson, Bryan P; Ikeda, Erika

    2016-07-01

    Kilding, AE, Dobson, BP, and Ikeda, E. Effects of acutely intermittent hypoxic exposure on running economy and physical performance in basketball players. J Strength Cond Res 30(7): 2033-2042, 2016-The aim of this study was to determine the effect of short duration intermittent hypoxic exposure (IHE) on physical performance in basketball players. Using a single-blind placebo-controlled group design, 14 trained basketball players were subjected to 15 days of passive short duration IHE (n = 7), or normoxic control (CON, n = 7), using a biofeedback nitrogen dilution device. A range of physiological, performance, and hematological variables were measured at baseline, and 10 days after IHE. After intervention, the IHE group, relative to the CON group, exhibited improvements in the Yo-Yo intermittent recovery level 1 (+4.8 ± 1.6%; effect size [ES]: 1.0 ± 0.4) and repeated high-intensity exercise test performance (-3.5 ± 1.6%; ES: -0.4 ± 0.2). Changes in hematological parameters were minimal, although soluble transferrin receptor increased after IHE (+9.2 ± 10.1%; ES: 0.3 ± 0.3). Running economy at 11 km·h (-9.0 ± 9.7%; ES: -0.7 ± 0.7) and 13 km·h was improved (-8.2 ± 6.9%; ES: -0.7 ± 0.5), but changes to V[Combining Dot Above]O2peak, HRpeak, and lactate were unclear. In summary, acutely IHE resulted in worthwhile changes in physical performance tests among competitive basketball players. However, physiological measures explaining the performance enhancement were in most part unclear.

  20. Short-term Risk of Serious Fall Injuries in Older Adults Initiating and Intensifying Treatment with Antihypertensive Medication

    Science.gov (United States)

    Shimbo, Daichi; Bowling, C. Barrett; Levitan, Emily B.; Deng, Luqin; Sim, John J.; Huang, Lei; Reynolds, Kristi; Muntner, Paul

    2016-01-01

    Background Antihypertensive medication use has been associated with an increased risk of falls in some but not all studies. Few data are available on the short-term risk of falls following antihypertensive medication initiation and intensification. Methods and Results We examined the association between initiating and intensifying antihypertensive medication and serious fall injuries in a case-crossover study of 90,127 Medicare beneficiaries who were ≥65 years old and had a serious fall injury between July 1, 2007 and December 31, 2012, based on emergency department and inpatient claims. Antihypertensive medication initiation was defined by a prescription fill with no fills in the prior year. Intensification was defined by the addition of a new antihypertensive class, and, separately, titration by the addition of a new class or increase in dosage of a current class. Exposures were ascertained for the 15 days before the fall (case period) and six 15-day earlier periods (control periods). Overall, 272, 1508, and 3113 Medicare beneficiaries initiated, added a new class of antihypertensive medication or titrated therapy, respectively, within 15 days of their serious fall injury. The odds for a serious fall injury was increased during the 15 days following antihypertensive medication initiation [odds ratio, OR, 1.36 (95% CI 1.19, 1.55)], adding a new class [OR 1.16 (95% CI 1.10, 1.23)], and titration [OR 1.13 (95% CI 1.08, 1.18)]. These associations were attenuated beyond 15 days. Conclusions Antihypertensive medication initiation and intensification was associated with a short-term, but not long-term, increased risk of serious fall injuries among older adults. PMID:27166208

  1. Short communication: Pharmacokinetics of intramammary hetacillin in dairy cattle milked 3 times per day.

    Science.gov (United States)

    Lindquist, Danielle A; Baynes, Ronald E; Smith, Geof W

    2015-03-01

    Mastitis remains a critical disease in the dairy industry and the use of intramammary antibiotics plays a critical role in mastitis treatment. Hetacillin is currently approved as an intramammary antibiotic that is used to treat mastitis in dairy cows. It is approved for once a day administration and can be used for a total of 3 d. An increasing number of dairy farms are milking 3 times per day (instead of the traditional 2 times per day) and very little pharmacokinetic data exists on the use of intramammary drugs in a 3×system. The primary purpose of this study was to determine if once a day intramammary infusion of hetacillin is sufficient to maintain therapeutic drug concentrations in cattle milked 3 times per day. Eight Holstein cattle milked 3 times per day were used in this study. After collecting a baseline milk sample, each cow received intramammary infusions of hetacillin in the left front and right rear quarters once a day for 3 d. Milk samples from each of the treated quarters were collected at each milking and frozen until analysis. Milk samples were analyzed for ampicillin concentrations using an ultra-performance liquid chromatography method. All treated quarters had antibiotic concentrations well above the minimum inhibitory concentration (MIC) for gram-positive mastitis pathogens at 8 and 16 h postinfusion. Milk concentrations had fallen well below the MIC by the 24-h period (before the next infusion). All 8 cows in this study consistently had individual quarter milk ampicillin concentrations below the FDA tolerance of 0.01 μg/mL (10 ppb) within 48 h of the last infusion. Based on this study, milk ampicillin concentrations exceed the minimum inhibitory concentration required to inhibit the growth of 90% of organisms (MIC90) for at least 65% of the dosing interval, which is sufficient for once-daily dosing with most cases of gram-positive mastitis. Therefore, intramammary hetacillin should be an effective treatment for the vast majority of gram

  2. Improving creativity performance by short-term meditation

    Science.gov (United States)

    2014-01-01

    Background One form of meditation intervention, the integrative body-mind training (IBMT) has been shown to improve attention, reduce stress and change self-reports of mood. In this paper we examine whether short-term IBMT can improve performance related to creativity and determine the role that mood may play in such improvement. Methods Forty Chinese undergraduates were randomly assigned to short-term IBMT group or a relaxation training (RT) control group. Mood and creativity performance were assessed by the Positive and Negative Affect Schedule (PANAS) and Torrance Tests of Creative Thinking (TTCT) questionnaire respectively. Results As predicted, the results indicated that short-term (30 min per day for 7 days) IBMT improved creativity performance on the divergent thinking task, and yielded better emotional regulation than RT. In addition, cross-lagged analysis indicated that both positive and negative affect may influence creativity in IBMT group (not RT group). Conclusions Our results suggested that emotion-related creativity-promoting mechanism may be attributed to short-term meditation. PMID:24645871

  3. Response of Lemna minor L. to short-term cobalt exposure: The effect on photosynthetic electron transport chain and induction of oxidative damage.

    Science.gov (United States)

    Begović, Lidija; Mlinarić, Selma; Antunović Dunić, Jasenka; Katanić, Zorana; Lončarić, Zdenko; Lepeduš, Hrvoje; Cesar, Vera

    2016-06-01

    The effect of two concentrations of cobalt (Co(2+)) on photosynthetic activity and antioxidative response in Lemna minor L. were assessed 24, 48 and 72h after the start of the exposure. Higher concentration of cobalt (1mM) induced growth inhibition while lower concentration (0.01mM) increased photosynthetic pigments content. Analysis of chlorophyll a fluorescence transients revealed high sensitivity of photosystem II primary photochemistry to excess of Co(2+) especially at the higher concentration where decreased electron transport beyond primary quinone acceptor QA(-) and impaired function of oxygen evolving complex (OEC) was observed. Due to impairment of OEC, oxygen production was decreased at higher Co(2+) concentration. Activity of superoxide dismutase was mainly inhibited while lipid peroxidation increased, at both concentrations, indicating that cobalt-induced oxidative damage after short exposure and moreover, susceptibility of the membranes in the cell to cobalt toxicity. Results obtained in this study suggest possible application of used parameters as tools in assessment of early damage caused by metals. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Short-term and latent post-settlement effects associated with elevated temperature and oxidative stress on larvae from the coral Porites astreoides

    Science.gov (United States)

    Ross, C.; Ritson-Williams, R.; Olsen, K.; Paul, V. J.

    2013-03-01

    Coral reefs across the Caribbean are undergoing unprecedented rates of decline in coral cover during the last three decades, and coral recruitment is one potential process that could aid the recovery of coral populations. To better understand the effects of climate change on coral larval ecology, the larvae of Porites astreoides were studied to determine the immediate and post-settlement effects of elevated temperature and associated oxidative stress. Larvae of Porites astreoides were exposed to 27 °C (ambient) and +3.0 °C (elevated temperature) seawater for a short duration of 24 h; then, a suite of physiological parameters were measured to determine the extent of sublethal stress. Following the +3.0 °C treatment, larvae did not show a significant difference in maximum quantum yield of PSII ( F v/ F m) or respiratory demand when compared to controls maintained at 27 °C. The addition of micromolar concentrations of hydrogen peroxide did not impact respiration or photochemical efficiency. Catalase activity in the larvae increased (>60 %) following exposure to elevated temperature when compared to the controls. Short-term larval survival and settlement and metamorphosis were not affected by increased temperature or the H2O2 treatment. However, the settled spat that were exposed to elevated temperature underwent a 99 % reduction in survival compared to 90 % reduction for the control spat when examined 24 days following the deployment of 4-day-old settled spat on settlement tiles in the field. These results show that short-term exposure to some stressors might have small impacts on coral physiology, and no effects on larval survival, settlement and metamorphosis. However, due to post-settlement mortality, these stressors can cause a significant reduction in coral recruitment.

  5. Effects of 12 days exposure to simulated microgravity on central circulatory hemodynamics in the rhesus monkey

    Science.gov (United States)

    Convertino, V. A.; Koenig, S. C.; Krotov, V. P.; Fanton, J. W.; Korolkov, V. I.; Trambovetsky, E. V.; Ewert, D. L.; Truzhennikov, A.; Latham, R. D.

    1998-01-01

    Central circulatory hemodynamic responses were measured before and during the initial 9 days of a 12-day 10 degrees head-down tilt (HDT) in 4 flight-sized juvenile rhesus monkeys who were surgically instrumented with a variety of intrathoracic catheters and blood flow sensors to assess the effects of simulated microgravity on central circulatory hemodynamics. Each subject underwent measurements of aortic and left ventricular pressures, and aortic flow before and during HDT as well as during a passive head-up postural test before and after HDT. Heart rate, stroke volume, cardiac output, and left ventricular end-diastolic pressure were measured, and dP/dt and left ventricular elastance was calculated from hemodynamic measurements. The postural test consisted of 5 min of supine baseline control followed by 5 minutes of 90 degrees upright tilt (HUT). Heart rate, stroke volume, cardiac output, and left ventricular end-diastolic pressure showed no consistent alterations during HDT. Left ventricular elastance was reduced in all animals throughout HDT, indicating that cardiac compliance was increased. HDT did not consistently alter left ventricular +dP/dt, indicating no change in cardiac contractility. Heart rate during the post-HDT HUT postural test was elevated compared to pre-HDT while post-HDT cardiac output was decreased by 52% as a result of a 54% reduction in stroke volume throughout HUT. Results from this study using an instrumented rhesus monkey suggest that exposure to microgravity may increase ventricular compliance without alternating cardiac contractility. Our project supported the notion that an invasively-instrumented animal model should be viable for use in spaceflight cardiovascular experiments to assess potential changes in myocardial function and cardiac compliance.

  6. The syndrome of inappropriate antidiuretic hormone secretion after giant leaf frog (Phyllomedusa bicolor) venom exposure.

    Science.gov (United States)

    Leban, Vid; Kozelj, Gordana; Brvar, Miran

    2016-09-15

    In Europe body purification and natural balance restoring rituals are becoming increasingly popular, but an introduction of Amazonian shamanic rituals in urban Europe can result in unexpected adverse events. A 44-year-old woman attended a Kambô or Sapo ritual in Slovenia where dried skin secretion from a giant leaf frog (Phyllomedusa bicolor) was applied to five freshly burned wounds at her shoulder. Afterwards, she drank 6 litres of water and gradually developed nausea and vomiting, confusion, lethargy, muscle weakness, spasms and cramps, seizure, decreased consciousness level and short-term memory loss. The initial laboratory tests showed profound plasma hypoosmolality (251 mOsm/kg) proportional to hyponatremia (116 mmol/L) combined with inappropriately elevated urine osmolality (523 mOsm/kg) and high urine sodium concentration (87 mmol/L) indicating a syndrome of inappropriate antidiuretic hormone secretion. The patient was treated with 0.9% sodium chloride and a restriction of water intake. Plasma osmolality and hyponatremia improved one day after venom exposure, but the symptoms disappeared as late as the third day. In patients presenting with neurological symptoms and a line of small body burns Phyllomedusa bicolor venom exposure should be suspected. Acute symptomatic hyponatremia after Phyllomedusa bicolor venom exposure is the result of inappropriate antidiuretic hormone secretion that can be exacerbated by excessive water intake. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Chronic obstructive pulmonary disease symptom effects of long-term cumulative exposure to ambient levels of total suspended particulates and sulfur dioxide in California Seventh-Day Adventist residents

    Energy Technology Data Exchange (ETDEWEB)

    Euler, G.L.; Abbey, D.E.; Magie, A.R.; Hodgkin, J.E.

    1987-07-01

    Risk of chronic obstructive pulmonary disease symptoms due to long-term exposure to ambient levels of total suspended particulates (TSP) and sulfur dioxide (SO/sub 2/) symptoms was ascertained using the National Heart, Lung, and Blood Institute (NHLBI) respiratory symptoms questionnaire on 7445 Seventh-Day Adventists. They were non-smokers, at least 25 yr of age, and had lived 11 yr or more in areas ranging from high to low photochemical air pollution in California. Participant cumulative exposures to each pollutant in excess of four thresholds were estimated using monthly residence zip code histories and interpolated dosages from state air monitoring stations. These pollutant thresholds were entered individually and in combination in multiple logistic regression analyses with eight covariables including passive smoking. Statistically significant associations with chronic symptoms were seen for: SO/sub 2/ exposure above 4 pphm (104 mcg/m3), (p = .03), relative risk 1.18 for 500 hr/yr of exposure; and for total suspended particulates (TSP) above 200 mcg/m3, (p less than .00001), relative risk of 1.22 for 750 hr/yr.

  8. Hyperspectral signature analysis of three plant species to long-term hydrocarbon and heavy metal exposure

    Science.gov (United States)

    Lassalle, Guillaume; Credoz, Anthony; Fabre, Sophie; Hédacq, Rémy; Dubucq, Dominique; Elger, Arnaud

    2017-10-01

    Recent studies aim to exploit vegetation hyperspectral signature as an indicator of pipeline leakages and natural oil seepages by detecting changes in reflectance induced by oil exposure. In order to assess the feasibility of the method at larger spatial scale, a study has been carried out in a greenhouse on two tropical (Cenchrus alopecuroides and Panicum virgatum) and a temperate (Rubus fruticosus) species. Plants were grown on contaminated soil during 130 days, with concentrations up to 4.5 and 36 g.kg-1 for heavy metals and C10-C40 hydrocarbons respectively. Reflectance data (350-2500 nm) were acquired under artificial light from 1 to 60 days. All species showed an increase of reflectance in the visible (VIS, 400-750 nm) and short-wave infrared (SWIR, 1300-2500 nm) under experimental contaminants exposure. However, the responses were contrasted in the near-infrared (NIR, 750-1300 nm). 47 normalized vegetation indices were compared between treatments, and the most sensitive to contamination were retained. Same indices showed significant differences between treatments at leaf and plant scales. Indices related to plant pigments, plant water content and red-edge reflectance were particularly sensitive to soil contamination. In order to validate the selection of indices, hyperspectral measurements were performed outdoor at plant scale at the end of the experiment (130 days). Leaf samples were also collected for pigment analysis. Index selected at day 60 were still sensitive to soil contamination after 130 days. Significant changes in plant pigment composition were also observed. This study demonstrates the interest of hyperspectral data for oil exploration and environmental diagnosis.

  9. Perfluorooctanoic acid exposure for 28 days affects glucose homeostasis and induces insulin hypersensitivity in mice

    Science.gov (United States)

    Yan, Shengmin; Zhang, Hongxia; Zheng, Fei; Sheng, Nan; Guo, Xuejiang; Dai, Jiayin

    2015-06-01

    Perfluoroalkyl acids (PFAAs) are widely used in many applications due to their unique physical and chemical characteristics. Because of the increasing prevalence of metabolic syndromes, including obesity, dyslipidemia and insulin resistance, concern has arisen about the roles of environmental pollutants in such diseases. Earlier epidemiologic studies showed a potential association between perfluorooctanoic acid (PFOA) and glucose metabolism, but how PFOA influences glucose homeostasis is still unknown. Here, we report on the modulation of the phosphatidylinositol 3-kinase-serine/threonine protein kinase (PI3K-AKT) signaling pathway in the livers of mice after 28 d of exposure to PFOA. Compared with normal mice, PFOA exposure significantly decreased the expression of the phosphatase and tensin homologue (PTEN) protein and affected the PI3K-AKT signaling pathway in the liver. Tolerance tests further indicated that PFOA exposure induced higher insulin sensitivity and glucose tolerance in mice. Biochemical analysis revealed that PFOA exposure reduced hepatic glycogen synthesis, which might be attributed to gluconeogenesis inhibition. The levels of several circulating proteins were altered after PFOA exposure, including proteins potentially related to diabetes and liver disease. Our results suggest that PFOA affected glucose metabolism and induced insulin hypersensitivity in mice.

  10. A survey of short-term and long-term stability of tube parameters in a mammography unit

    Directory of Open Access Journals (Sweden)

    Praskalo Jovica Ž.

    2014-01-01

    Full Text Available In order to set up a successful mammography screening program in the Republic of Srpska, a Siemens Mammomat 1000 X-ray machine was selected for analysis as the said mammography system is widely used in clinical practice. The variations in tube parameters (specific air kerma, high-voltage accuracy and reproducibility, linearity between exposure and dose exposure time were monitored over a five-year period, from 2008 to 2012. In addition, due to observed daily fluctuations for chosen parameters, a series of measurements were performed three times a day within a single-month period (mainly October 2012. The goal of such an experimental set up is to assess short-term and long-term stability of tube parameters in the given mammography unit and to make a comparison between them. The present paper shows how an early detection of significant parameter fluctuations can help eliminate irregularities and optimize the performance of mammography systems. [Projekat Ministarstva nauke Republike Srbije, br. 171007

  11. The association between socioeconomic status and exposure to mobile telecommunication networks in children and adolescents.

    Science.gov (United States)

    Thomas, Silke; Heinrich, Sabine; Kühnlein, Anja; Radon, Katja

    2010-01-01

    A potential association between socioeconomic status (SES) and self-reported use of mobile phones has been investigated in a few studies. If measured exposure to mobile phone networks differs by SES in children, it has not yet been studied. Interview data of 1,481 children and 1,505 adolescents on participants' mobile phone use, socio-demographic characteristics and potential confounders were taken from the German MobilEe-study. Sociodemographic data was used to stratify participants into three "status groups" (low, middle, high). Using a personal dosimeter, we obtained an exposure profile over 24 h for each of the participants. Exposure levels during waking hours were expressed as mean percentage of the reference level. Children with a low SES were more likely to own a mobile phone (OR 2.1; 95% CI: 1.1-3.9) and also reported to use their mobile phone longer per day (OR 2.4; 95% CI: 1.1-5.4) than children with a high SES. For adolescents, self-reported duration of mobile phone use per day was also higher with a low SES (OR: 3.4; 95% CI: 1.4-8.4) compared with a high SES. No association between SES and measured exposure to mobile telecommunication networks was seen for children or adolescents. Mobile phone use may differ between status groups with higher use among disadvantaged groups. However, this does not result in higher overall exposure to mobile telecommunication networks. Whether short duration of own mobile phone use or the small numbers of participants with a low SES are causal, have to be investigated in further studies. (c) 2009 Wiley-Liss, Inc.

  12. John Deakin: Double Exposures

    Directory of Open Access Journals (Sweden)

    Paul Rousseau

    2015-11-01

    Full Text Available In this series of short films made by Jonathan Law, the art historian James Boaden, and the curator of The John Deakin Archive, Paul Rousseau, discuss the double-exposure images made by the photographer John Deakin (1912-1972 in the 1950s and 1960s. The films ask you, firstly, to look closely at the images being discussed. Each one begins with a sustained and intense shot of a single image before opening up to a wide-ranging discussion about Deakin, double exposures, and photography.

  13. Consequences of early postnatal benzodiazepines exposure in rats. II. Social behavior

    Directory of Open Access Journals (Sweden)

    Anna eMikulecka

    2014-05-01

    Full Text Available Social behavior represents an integral part of behavioral repertoire of rats particularly sensitive to pharmacological and environmental influences. The aim of the present study was to investigate whether early postnatal clonazepam (CZP exposure can induce age-dependent changes related to expression of social behavior. The drug was administered from postnatal day (P 7 until P11 at daily doses of 0.1, 0.5 and 1.0 mg/kg i.p. We designed three experiments to assess whether exposure to CZP affects social behavior in respect to the age of rats and the test circumstances, specifically their familiarity with test conditions during adolescence (P32, social behavior in juveniles and adolescents (P18-P42 and social behavior in a resident-intruder paradigm. The frequency and duration of a various patterns of social behavior related to play and social investigation not related to play were evaluated. The results showed that CZP postnatal exposure decreased social play behavior regardless of age and familiarity or unfamiliarity of experimental environment but did not affect the social investigation per se. When rats were confronted with an intruder in their home cages intense wrestling and inhibition of genital investigation were found. In conclusion, these findings show that short-term CZP postnatal exposure inhibits social play behavior and alters specific patterns of social behavior in an age and environment related manner

  14. Behavioral sensitization after repeated formaldehyde exposure in rats.

    Science.gov (United States)

    Sorg, B A; Hochstatter, T

    1999-01-01

    Multiple chemical sensitivity (MCS) is a phenomenon whereby individuals report increased sensitivity to chemicals in the environment, and attribute their sensitivities to prior exposure to the same or often structurally unrelated chemicals. A leading hypothesis suggests that MCS is akin to behavioral sensitization observed in rodents after repeated exposure to drugs of abuse or environmental stressors. Sensitization occurring within limbic circuitry of the central nervous system (CNS) may explain the multisymptom complaints in individuals with MCS. The present studies represent the continuing development of an animal model for MCS, the basis of which is the CNS sensitization hypothesis. Three behaviors were assessed in rats repeatedly exposed to formaldehyde (Form) inhalation. In the first series of experiments, rats were given high-dose Form exposure (11 parts per million [ppm]; 1 h/day x 7 days) or low-dose Form exposure (1 ppm; either 1 h/day x 7 days or 1 h/day x 5 days/week x 4 weeks). Within a few days after discontinuing daily Form, cocaine-induced locomotor activity was elevated after high-dose Form or 20 days of low-dose Form inhalation. Approximately 1 month later, cocaine-induced locomotor activity remained significantly elevated in the 20-day Form-exposed rats. The second experiment assessed whether prior exposure to Form (20 days, as above) would alter the ability to condition to an odor (orange oil) paired with footshock. The results suggested a tendency to increase the conditioned fear response to the odor but not the context of the footshock box, and a decreased tendency to extinguish the conditioned fear response to odor. The third experiment examined whether CNS sensitization to daily cocaine or stress would alter subsequent avoidance responding to odor (Form). Daily cocaine significantly elevated approach responses to Form, while daily stress pretreatment produced a trend in the opposite direction, producing greater avoidance of Form. Preliminary

  15. The effects of the administration of two different doses of manganese on short-term spatial memory and anxiety-like behavior in rats

    Directory of Open Access Journals (Sweden)

    Hogas M.

    2011-01-01

    Full Text Available Manganese is a very well known neurotoxic agent. It has been mainly linked to impaired motor skills and disturbed psychomotor development. However, very few aspects are known about the cognitive deficits and behavioral consequences of chronic manganese exposure. In this context, we report herein our findings regarding short-term spatial memory, motor and anxiety-like behavior assessments in male Wistar rats exposed for 45 days to two different doses (3 mg/kg b.w., i.p. and 10 mg/kg b.w., i.p. of manganese. Behavior testing (Y-maze task and elevated plus maze was performed after 45 days of manganese administration. Chronic manganese exposure in Wistar rats led to behavioral alterations consisting of cognitive deficiencies in the Y-maze task and anxiety/compulsive-like behaviors in the elevated plus maze, but no motor disturbances as tested by the number of arm entries in the Y-maze. Additional work is necessary to understand the longterm effects of different doses and dosing regimens of manganese on cognitive/affective and motor functioning.

  16. Peripheral kisspeptin reverses short photoperiod-induced gonadal regression in Syrian hamsters by promoting GNRH release

    DEFF Research Database (Denmark)

    Ansel, L; Bentsen, A H; Ancel, C

    2011-01-01

    In seasonal breeders, reproduction is synchronised by day length via the pineal hormone melatonin. In short winter days (short day, SD), the Syrian hamster displays a complete gonadal atrophy together with a marked reduction in expression of kisspeptins (Kp), a family of potent hypothalamic stimu...

  17. Testing day: The effects of processing bias induced by Navon stimuli on the strength of the Müller-Lyer illusion.

    Science.gov (United States)

    Mundy, Matthew E

    2014-01-01

    Explanations for the cognitive basis of the Müller-Lyer illusion are still frustratingly mixed. To date, Day's (1989) theory of perceptual compromise has received little empirical attention. In this study, we examine the merit of Day's hypothesis for the Müller-Lyer illusion by biasing participants toward global or local visual processing through exposure to Navon (1977) stimuli, which are known to alter processing level preference for a short time. Participants (N = 306) were randomly allocated to global, local, or control conditions. Those in global or local conditions were exposed to Navon stimuli for 5 min and participants were required to report on the global or local stimulus features, respectively. Subsequently, participants completed a computerized Müller-Lyer experiment where they adjusted the length of a line to match an illusory-figure. The illusion was significantly stronger for participants with a global bias, and significantly weaker for those with a local bias, compared with the control condition. These findings provide empirical support for Day's "conflicting cues" theory of perceptual compromise in the Müller-Lyer illusion.

  18. Impact of a five-day short course on integration of health promotion into practice in north Queensland.

    Science.gov (United States)

    Devine, Susan G; Llewellyn-Jones, Lorraine; Lloyd, Jacqui

    2009-04-01

    Workforce development is one element of health promotion capacity building. This paper describes the extent to which participants in a five-day short course in health promotion, delivered three times in north Queensland during 2007, reported greater adoption of health promotion within their work roles, and the factors that affected the level of adoption. Out of 54 course attendees, 39 completed a post-course survey five to nine months after completing the course (72% response rate). Additionally, 11 course attendees participated in a focus group or phone interview to explore survey findings. The courses succeeded in providing knowledge, skills, confidence and enthusiasm to undertake health promotion work. Eighty per cent of participants stated they had incorporated health promotion into their work frequently or all of the time since undertaking the course. Lack of understanding of health promotion from co-workers and managers, lack of organisational support and commitment, lack of resources, competing clinical priorities, and lack of time were cited as the main barriers for undertaking health promotion. The course met participant training needs. However, similar training across all levels of staff including management may help to develop organisational capacity, thereby building a more knowledgeable workforce that is supported to undertake health promotion as a core part of an organisation's business.

  19. Vast Portfolio Selection with Gross-exposure Constraints().

    Science.gov (United States)

    Fan, Jianqing; Zhang, Jingjin; Yu, Ke

    2012-01-01

    We introduce the large portfolio selection using gross-exposure constraints. We show that with gross-exposure constraint the empirically selected optimal portfolios based on estimated covariance matrices have similar performance to the theoretical optimal ones and there is no error accumulation effect from estimation of vast covariance matrices. This gives theoretical justification to the empirical results in Jagannathan and Ma (2003). We also show that the no-short-sale portfolio can be improved by allowing some short positions. The applications to portfolio selection, tracking, and improvements are also addressed. The utility of our new approach is illustrated by simulation and empirical studies on the 100 Fama-French industrial portfolios and the 600 stocks randomly selected from Russell 3000.

  20. Inulin Supplementation Lowered the Metabolic Defects of Prolonged Exposure to Chlorpyrifos from Gestation to Young Adult Stage in Offspring Rats.

    Science.gov (United States)

    Reygner, Julie; Lichtenberger, Lydia; Elmhiri, Ghada; Dou, Samir; Bahi-Jaber, Narges; Rhazi, Larbi; Depeint, Flore; Bach, Veronique; Khorsi-Cauet, Hafida; Abdennebi-Najar, Latifa

    2016-01-01

    Increasing evidence indicates that chlorpyrifos (CPF), an organophosphorus insecticide, is involved in metabolic disorders. We assess the hypothesis whether supplementation with prebiotics from gestation to adulthood, through a modulation of microbiota composition and fermentative activity, alleviates CPF induced metabolic disorders of 60 days old offspring. 5 groups of Wistar rats, from gestation until weaning, received two doses of CPF pesticide: 1 mg/kg/day (CPF1) or 3.5 mg/kg/day (CPF3.5) with free access to inulin (10g/L in drinking water). Then male pups received the same treatment as dams. Metabolic profile, leptin sensitivity, insulin receptor (IR) expression in liver, gut microbiota composition and short chain fatty acid composition (SCFAs) in the colon, were analyzed at postnatal day 60 in the offspring (PND 60). CPF3.5 increased offspring's birth body weight (BW) but decreased BW at PND60. Inulin supplementation restored the BW at PND 60 to control levels. Hyperinsulinemia and decrease in insulin receptor β in liver were seen in CPF1 exposed rats. In contrast, hyperglycemia and decrease in insulin level were found in CPF3.5 rats. Inulin restored the levels of some metabolic parameters in CPF groups to ranges comparable with the controls. The total bacterial population, short chain fatty acid (SCFA) production and butyrate levels were enhanced in CPF groups receiving inulin. Our data indicate that developmental exposure to CPF interferes with metabolism with dose related effects evident at adulthood. By modulating microbiota population and fermentative activity, inulin corrected adult metabolic disorders of rats exposed to CPF during development. Prebiotics supply may be thus considered as a novel nutritional strategy to counteract insulin resistance and diabetes induced by a continuous pesticide exposure.

  1. Inulin Supplementation Lowered the Metabolic Defects of Prolonged Exposure to Chlorpyrifos from Gestation to Young Adult Stage in Offspring Rats.

    Directory of Open Access Journals (Sweden)

    Julie Reygner

    Full Text Available Increasing evidence indicates that chlorpyrifos (CPF, an organophosphorus insecticide, is involved in metabolic disorders. We assess the hypothesis whether supplementation with prebiotics from gestation to adulthood, through a modulation of microbiota composition and fermentative activity, alleviates CPF induced metabolic disorders of 60 days old offspring. 5 groups of Wistar rats, from gestation until weaning, received two doses of CPF pesticide: 1 mg/kg/day (CPF1 or 3.5 mg/kg/day (CPF3.5 with free access to inulin (10g/L in drinking water. Then male pups received the same treatment as dams. Metabolic profile, leptin sensitivity, insulin receptor (IR expression in liver, gut microbiota composition and short chain fatty acid composition (SCFAs in the colon, were analyzed at postnatal day 60 in the offspring (PND 60. CPF3.5 increased offspring's birth body weight (BW but decreased BW at PND60. Inulin supplementation restored the BW at PND 60 to control levels. Hyperinsulinemia and decrease in insulin receptor β in liver were seen in CPF1 exposed rats. In contrast, hyperglycemia and decrease in insulin level were found in CPF3.5 rats. Inulin restored the levels of some metabolic parameters in CPF groups to ranges comparable with the controls. The total bacterial population, short chain fatty acid (SCFA production and butyrate levels were enhanced in CPF groups receiving inulin. Our data indicate that developmental exposure to CPF interferes with metabolism with dose related effects evident at adulthood. By modulating microbiota population and fermentative activity, inulin corrected adult metabolic disorders of rats exposed to CPF during development. Prebiotics supply may be thus considered as a novel nutritional strategy to counteract insulin resistance and diabetes induced by a continuous pesticide exposure.

  2. Real-time energy resources scheduling considering short-term and very short-term wind forecast

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marco; Sousa, Tiago; Morais, Hugo; Vale, Zita [Polytechnic of Porto (Portugal). GECAD - Knowledge Engineering and Decision Support Research Center

    2012-07-01

    This paper proposes an energy resources management methodology based on three distinct time horizons: day-ahead scheduling, hour-ahead scheduling, and real-time scheduling. In each scheduling process the update of generation and consumption operation and of the storage and electric vehicles storage status are used. Besides the new operation conditions, the most accurate forecast values of wind generation and of consumption using results of short-term and very short-term methods are used. A case study considering a distribution network with intensive use of distributed generation and electric vehicles is presented. (orig.)

  3. Effect of leucine supplementation on fat free mass with prolonged hypoxic exposure during a 13-day trek to Everest Base Camp: a double-blind randomized study.

    Science.gov (United States)

    Wing-Gaia, Stacie L; Gershenoff, Dana C; Drummond, Micah J; Askew, E Wayne

    2014-03-01

    Loss of body weight and fat-free mass (FFM) are commonly noted with prolonged exposure to hypobaric hypoxia. Recent evidence suggests protein supplementation, specifically leucine, may potentially attenuate loss of FFM in subcaloric conditions during normoxia. The purpose of this study was to determine if leucine supplementation would prevent the loss of FFM in subcaloric conditions during prolonged hypoxia. Eighteen physically active male (n = 10) and female (n = 8) trekkers completed a 13-day trek in Nepal to Everest Base Camp with a mean altitude of 4140 m (range 2810-5364 m). In this double-blind study, participants were randomized to ingest either leucine (LEU) (7 g leucine, 93 kcal, 14.5 g whey-based protein) or an isocaloric isonitrogenous control (CON) (0.3 g LEU, 93 kcal, 11.3 g collagen protein) twice daily prior to meals. Body weight, body composition, and circumferences of bicep, thigh, and calf were measured pre- and post-trek. There was a significant time effect for body weight (-2.2% ± 1.7%), FFM (-1.7% ± 1.5%), fat mass (-4.0% ± 6.9%), and circumferences (p FFM (CON -2.1 ± 1.5%; LEU -1.2 ± 1.6%), fat mass (CON -2.9% ± 5.9%; LEU -5.4% ± 8.1%), or circumferences. Although a significant loss of body weight, FFM, and fat mass was noted in 13 days of high altitude exposure, FFM loss was not attenuated by leucine. Future studies are needed to determine if leucine attenuates loss of FFM with longer duration high altitude exposure.

  4. 1976 Hanford Americium exposure incident: hematologic effects

    International Nuclear Information System (INIS)

    Ragan, H.A.; Mahaffey, J.A.; Breitenstein, B.D.

    1982-05-01

    Hematologic evaluation of an individual with an initial systemic body burden of approx. 200 μCi 241 Am revealed a significant (P < 0.01) reduction of total leukocytes, neutrophils, and lymphocytes. This effect on total leukocytes and neutrophils was evident approx. 30 days after exposure, appeared to stabilize at about 3 months after exposure, and remained at this lower level thorugh a 52-months observation period. The effect on lymphocytes was apparent by 3 days after exposure, stabilizing at approx. 50% of pre-exposure values for about 7 months, with a return to pre-exposure levels in the following 4 y. There was a progressive and significant (P < 0.001) decline in platelet counts during the 52-months postexposure period. The pattern of response in erythrocyte parameters was complex. Immediately after the accident, these values were less than the pre-exposure mean level; they gradually increased (P < 0.001) for approx. 2 y and then began a progressive decline (P < 0.001)

  5. Short-term exposure to ambient fine particulate matter (PM2,5 and PM10) and the risk of heart rhythm abnormalities and stroke.

    Science.gov (United States)

    Kowalska, Małgorzata; Kocot, Krzysztof

    2016-09-28

    Results of epidemiological studies suggest a significant impact of ambient particulate matter air pollution (PM10 and PM2,5) on the health of the population. Increased level of these pollutants is connected with increased rate of daily mortality and hospitalizations due to cardiovascular diseases. Among analyzed health effects, heart arrhythmias and stroke are mentioned most frequently. The aim of the study was to present the current knowledge of potential influence of the exposure to fine particulate matter on the presence of arrhythmias and strokes. Subject literature review suggests, that there is a link between short-term exposure to fine dust and the occurrence of arrhythmias. Results of previous studies indicates that this exposure may lead to significant electrophysiological changes in heart, resulting in higher susceptibility to cardiac rhythm abnormalities. In case of stroke, a stronger correlation between number of hospitalizations and death cases and exposure to fine dust was seen for ischaemic stroke than for haemorhhagic stroke. In addition, a significantly more harmful impact of the exposure to ultra particles (particles of aerodynamic diameter below 2,5 μm) has been confirmed. Among important mechanisms responsible for observed health impact of particulate matter there are: induction and intensification of inflammation, increased oxidative stress, increased autonomic nervous system activity, vasoconstriction, rheological changes and endothelial dysfunction. Among people of higher susceptibility to fine dust negative health impact are: elderly (over 65 years old), obese people, patients with respiratory and cardiovascular diseases, patients with diabetes and those with coagulation disorders. For further improvement of general health status, actions aimed at reducing the risk associated with fine dust and at the same time at continuing studies to clarify the biological mechanisms explaining the influence of fine dust on human health are necessary.

  6. Short-term exposure to ambient fine particulate matter (PM2,5 and PM10 and the risk of heart rhythm abnormalities and stroke

    Directory of Open Access Journals (Sweden)

    Małgorzata Kowalska

    2016-09-01

    Full Text Available Results of epidemiological studies suggest a significant impact of ambient particulate matter air pollution (PM10 and PM2,5 on the health of the population. Increased level of these pollutants is connected with increased rate of daily mortality and hospitalizations due to cardiovascular diseases. Among analyzed health effects, heart arrhythmias and stroke are mentioned most frequently. The aim of the study was to present the current knowledge of potential influence of the exposure to fine particulate matter on the presence of arrhythmias and strokes. Subject literature review suggests, that there is a link between short-term exposure to fine dust and the occurrence of arrhythmias. Results of previous studies indicates that this exposure may lead to significant electrophysiological changes in heart, resulting in higher susceptibility to cardiac rhythm abnormalities. In case of stroke, a stronger correlation between number of hospitalizations and death cases and exposure to fine dust was seen for ischaemic stroke than for haemorhhagic stroke. In addition, a significantly more harmful impact of the exposure to ultra particles (particles of aerodynamic diameter below 2,5 μm has been confirmed. Among important mechanisms responsible for observed health impact of particulate matter there are: induction and intensification of inflammation, increased oxidative stress, increased autonomic nervous system activity, vasoconstriction, rheological changes and endothelial dysfunction. Among people of higher susceptibility to fine dust negative health impact are: elderly (over 65 years old, obese people, patients with respiratory and cardiovascular diseases, patients with diabetes and those with coagulation disorders. For further improvement of general health status, actions aimed at reducing the risk associated with fine dust and at the same time at continuing studies to clarify the biological mechanisms explaining the influence of fine dust on human health

  7. Accidental over-exposure from dental X-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, B G [National Radiological Protection Board, Harwell (UK)

    1976-07-01

    A description is given of an unusual dental X-ray procedure which resulted in accidental over-exposure both to the dentist and to several of his patients when a short-circuit was present in newly-installed equipment. The short-circuit by-passed the exposure control and energized the tube for certain orientations of the X-ray tube. The dentist left the patients, who wore protective aprons, to initiate the exposure themselves, using the control button. Although the warning lights were on, the dentist was not present in the room during the exposure, and the over-exposures were only detected when the developed X-ray films were found to be completely blackened. A reconstruction of the procedure enabled estimates to be made of the dose equivalents to the dentist's body and to the skin of the head, the eyes and the gonads of the patients. The dentist had overlooked several of basic principles recommended in the Code of Practice for the Protection of Persons against Ionizing Radiations from Medical and Dental Use (1972). It is pointed out that incidents involving failure of dental equipment (usually the timer mechanism) are not infrequent.

  8. Effects of different inorganic arsenic species in Cyprinus carpio (Cyprinidae) tissues after short-time exposure: Bioaccumulation, biotransformation and biological responses

    International Nuclear Information System (INIS)

    Ventura-Lima, Juliane; Fattorini, Daniele; Regoli, Francesco; Monserrat, Jose M.

    2009-01-01

    Differences in the toxicological and metabolic pathway of inorganic arsenic compounds are largely unknown for aquatic species. In the present study the effects of short-time and acute exposure to As III and As V were investigated in gills and liver of the common carp, Cyprinus carpio (Cyprinidae), measuring accumulation and chemical speciation of arsenic, and the activity of glutathione-S-transferase omega (GST Ω), the rate limiting enzyme in biotransformation of inorganic arsenic. Oxidative biomarkers included antioxidant defenses (total glutathione-S-transferases, glutathione reductase, glutathione, and glucose-6-phosphate dehydrogenase), total scavenging capacity toward peroxyl radicals, reactive oxygen species (ROS) measurement and lipid peroxidation products. A marked accumulation of arsenic was observed only in gills of carps exposed to 1000 ppb As V . Also in gills, antioxidant responses were mostly modulated through a significant induction of glucose-6-phosphate dehydrogenase activity which probably contributed to reduce ROS formation; however this increase was not sufficient to prevent lipid peroxidation. No changes in metal content were measured in liver of exposed carps, characterized by lower activity of GST Ω compared to gills. On the other hand, glutathione metabolism was more sensitive in liver tissue, where a significant inhibition of glutathione reductase was concomitant with increased levels of glutathione and higher total antioxidant capacity toward peroxyl radicals, thus preventing lipid peroxidation and ROS production. The overall results of this study indicated that exposure of C. carpio to As III and As V can induce different responses in gills and liver of this aquatic organism. - Common carp (Cyprinus carpio) presented marked differences between gills and liver after arsenic exposure in terms of antioxidant responses and also in biotransformation.

  9. Development of acute exposure guideline levels for airborne exposures to hazardous substances.

    Science.gov (United States)

    Krewski, Daniel; Bakshi, Kulbir; Garrett, Roger; Falke, Ernest; Rusch, George; Gaylor, David

    2004-04-01

    Hazardous substances can be released into the atmosphere due to industrial and transportation accidents, fires, tornadoes, earthquakes, and terrorists, thereby exposing workers and the nearby public to potential adverse health effects. Various enforceable guidelines have been set by regulatory agencies for worker and ambient air quality. However, these exposure levels generally are not applicable to rare lifetime acute exposures, which possibly could occur at high concentrations. Acute exposure guideline levels (AEGLs) provide estimates of concentrations for airborne exposures for an array of short durations that possibly could cause mild (AEGL-1), severe, irreversible, potentially disabling adverse health effects (AEGL-2), or life threatening effects (AEGL-3). These levels can be useful for emergency responders and planners in reducing or eliminating potential risks to the public. Procedures and methodologies for deriving AEGLs are reviewed in this paper that have been developed in the United States, with direct input from international representatives of OECD member-countries, by the National Advisory Committee for Acute Exposure Guidelines for Hazardous Substances and reviewed by the National Research Council. Techniques are discussed for the extrapolation of effects across different exposure durations. AEGLs provide a viable approach for assisting in the prevention, planning, and response to acute airborne exposures to toxic agents.

  10. Children's exposure to polybrominated diphenyl ethers.

    Science.gov (United States)

    Zuurbier, Moniek; Leijs, Marike; Schoeters, Greet; ten Tusscher, Gavin; Koppe, Janna G

    2006-10-01

    Polybrominated biphenyl ethers (PBDEs), a class of brominated flame retardants, are frequently used in consumer products. PBDEs levels in environmental and human samples have increased in recent decades. Children are exposed to PBDEs through diet, mainly through fish, meat and milk. Total dietary exposure of children in Europe was calculated to be 2-3 ng/kg b.w./day. For nursing infants the main source of PBDE exposure is breast milk; exposure levels are around 15 ng/kg b.w./day. PBDE exposure levels in North America are 10 to a 100 times higher. Because of their persistence and their similarity to polychlorinated biphenyls (PCBs), concern has been raised about the effects of PBDEs on human health. Exposure to penta- and octa-BDE led to learning impairment and impaired motor behaviour in rodents. Exposure to penta-, octa- and also deca-BDE caused effects on thyroid homeostasis in animals. The EU has banned the production and use of penta- and octa-BDE since 2004; however, exposure will continue during the coming decades. Based upon current toxicological evidence, human exposure to deca-BDEs is not expected to lead to health effects, but data on exposure to deca-BDE and data on toxicity of deca-BDE are scarce. Therefore, monitoring studies and toxicity studies on deca-BDEs and other BDEs should continue.

  11. Anomalous high photoconductivity in short channel indium-zinc-oxide photo-transistors

    International Nuclear Information System (INIS)

    Choi, Hyun-Sik; Jeon, Sanghun

    2015-01-01

    Upon light exposure, an indium-zinc-oxide (IZO) thin-film transistor (TFT) presents higher photoconductivity by several orders of magnitude at the negative gate bias region. Among various device geometrical factors, scaling down the channel length of the photo-transistor results in an anomalous increase in photoconductivity. To probe the origin of this high photoconductivity in short-channel device, we measured transient current, current–voltage, and capacitance–voltage characteristics of IZO–TFTs with various channel lengths and widths before and after illumination. Under the illumination, the equilibrium potential region which lies far from front interface exists only in short-channel devices, forming the un-depleted conducting back channel. This region plays an important role in carrier transport under the illumination, leading to high photoconductivity in short-channel devices. Photon exposure coupled with gate-modulated band bending for short-channel devices leads to the accumulation of V o ++ at the front channel and screening negative gate bias, thereby generating high current flow in the un-depleted back-channel region

  12. Short sleep duration as a possible cause of obesity

    DEFF Research Database (Denmark)

    Nielsen, L S; Danielsen, Karen; Sørensen, T I A

    2011-01-01

    with particular emphasis on prospective studies. The studies showed that short sleep duration is consistently associated with development of obesity in children and young adults, but not consistently so in older adults. We have identified critical aspects of the evidence, and assessed the possibility...... for interpretation of the evidence in terms of causality. We have discussed the requirement of temporal sequence between putative exposure and outcome and the implications of the time lag between them, the problems in adequate measurements of exposure and effects, the possible bidirectional causal effects......Systematic literature search for epidemiological evidence for an association of short sleep with weight gain and eventual development of obesity provided 71 original studies and seven reviews of various subsets of these studies. We have summarized the evidence for such an association...

  13. Out of the Lab and into the Bathroom: Evening Short-Term Exposure to Conventional Light Suppresses Melatonin and Increases Alertness Perception

    Directory of Open Access Journals (Sweden)

    Heinz Schoepp

    2013-01-01

    Full Text Available Life in 24-h society relies on the use of artificial light at night that might disrupt synchronization of the endogenous circadian timing system to the solar day. This could have a negative impact on sleep–wake patterns and psychiatric symptoms. The aim of the study was to investigate the influence of evening light emitted by domestic and work place lamps in a naturalistic setting on melatonin levels and alertness in humans. Healthy subjects (6 male, 3 female, 22–33 years were exposed to constant dim light (<10 lx for six evenings from 7:00 p.m. to midnight. On evenings 2 through 6, 1 h before habitual bedtime, they were also exposed to light emitted by 5 different conventional lamps for 30 min. Exposure to yellow light did not alter the increase of melatonin in saliva compared to dim light baseline during (38 ± 27 pg/mL vs. 39 ± 23 pg/mL and after light exposure (39 ± 22 pg/mL vs. 44 ± 26 pg/mL. In contrast, lighting conditions including blue components reduced melatonin increase significantly both during (office daylight white: 25 ± 16 pg/mL, bathroom daylight white: 24 ± 10 pg/mL, Planon warm white: 26 ± 14 pg/mL, hall daylight white: 22 ± 14 pg/mL and after light exposure (office daylight white: 25 ± 15 pg/mL, bathroom daylight white: 23 ± 9 pg/mL, Planon warm white: 24 ± 13 pg/mL, hall daylight white: 22 ± 26 pg/mL. Subjective alertness was significantly increased after exposure to three of the lighting conditions which included blue spectral components in their spectra. Evening exposure to conventional lamps in an everyday setting influences melatonin excretion and alertness perception within 30 min.

  14. Effects of prenatal exposure to a low dose atrazine metabolite mixture on pubertal timing and prostate development of male Long-Evans rats

    Energy Technology Data Exchange (ETDEWEB)

    Stanko, Jason [National Institute of Environmental Health Sciences (NIEHS); Enoch, Rolondo [North Carolina Central University, Durham; Rayner, Jennifer L [ORNL; Davis, Christine [U.S. Environmental Protection Agency; Wolf, Douglas [U.S. Environmental Protection Agency; Malarkey, David [University of North Carolina, Chapel Hill; Fenton, Suzanne [National Institute of Environmental Health Sciences (NIEHS)

    2010-12-01

    The present study examines the postnatal reproductive development of male rats following prenatal exposure to an atrazine metabolite mixture (AMM) consisting of the herbicide atrazine and its environmental metabolites diaminochlorotriazine, hydroxyatrazine, deethylatrazine, and deisopropylatrazine. Pregnant Long-Evans rats were treated by gavage with 0.09, 0.87, or 8.73 mg AMM/kg body weight (BW), vehicle, or 100 mg ATR/kg BW positive control, on gestation days 15 19. Preputial separation was significantly delayed in 0.87 mg and 8.73 mg AMM-exposed males. AMM-exposed males demonstrated a significant treatment-related increase in incidence and severity of inflammation in the prostate on postnatal day (PND) 120. A dose-dependent increase in epididymal fat masses and prostate foci were grossly visible in AMM-exposed offspring. These results indicate that a short, late prenatal exposure to mixture of chlorotriazine metabolites can cause chronic prostatitis in male LE rats. The mode of action for these effects is presently unclear.

  15. Efficient algal bioassay based on short-term photosynthetic response

    International Nuclear Information System (INIS)

    Giddings, J.M.; Stewart, A.J.; O'Neill, R.V.; Gardner, R.H.

    1983-01-01

    A procedure is described for measuring the effects of toxicants on algal photosynthesis (carbon-14 bicarbonate (H 14 CO 3 )uptake) in 4-h experiments. The results for individual aromatic compounds and the water-soluble fraction (WSF) of a synthetic oil are presented as examples of applications of the bioassay. The toxicity of the WSF varied among the seven algal species tested, and the responses of some species were pH-dependent. With Selenastrum capricornutum as the test organism, the bioassay results were unaffected by variations in pH from 7.0 to 9.0, light intensity from 40 to 200 μeinsteins m -2 s -1 , culture density up to 0.5 mg chlorophyll a per litre, and agitation up to 100 rpm. The photosynthesis bioassay is simpler and faster (4 h versus 4 to 14 days), uses smaller culture volumes, and requires less space than static culture-growth tests. One person can conveniently test four materials per day, and the entire procedure, including preparation, exposure, and analysis, takes less than two days. The short incubation time reduces bottle effects such as pH changes, accumulation of metabolic products, nutrient depletion, and bacterial growth. Processes that remove or alter the test materials are also minimized. The data presented here indicate that algal photosynthesis is inhibited at toxicant concentrations similar to those that cause acute effects in aquatic animals. A model of a pelagic ecosystem is used to demonstrate that even temporary (seven-day) inhibition of algal photosynthesis can have a measurable impact on other trophic levels, particularly if the other trophic levels are also experiencing toxic effects. 25 references, 6 figures, 1 table

  16. [Accumulative effects and long-term persistence of subliminal mere exposure].

    Science.gov (United States)

    Kawakami, Naoaki; Yoshida, Fujio

    2011-10-01

    We examined the accumulative effects and long-term persistence of subliminal mere exposure. An accumulative exposure condition (100 exposures distributed over five days) and a massed exposure condition (100 exposures in one day) were used in a Go/No-go Association Task (GNAT), with assessments of likability from Time 1 (just after) to Time 6 (after three months). First, a single stimulus was shown subliminally for a total of 100 times. The results indicated that mere exposure effects occurred equally often at Time 1. However, after Time 2, likability gradually decreased under the massed exposure condition, while it did not decrease under the accumulative exposure condition until Time 6. Second, in order to investigate the effect of multiple exposure, five stimuli belonging to a common category were shown 20 times each, for a total of 100 times. An ANOVA suggested that massed exposure had an instantaneous effect on likability, whereas accumulative exposure had a long-term persistence effect. Also, multiple exposures strengthened the mere exposure effect.

  17. Attenuated response to repeated daily ozone exposures in asthmatic subjects

    Energy Technology Data Exchange (ETDEWEB)

    Gong, H. Jr.; Linn, W.S. [Rancho Low Amigos Medical Center, Downey, CA (United States); McManus, M.S. [Univ. of California, Los Angeles, CA (United States)

    1997-01-01

    The development of attenuated response ({open_quotes}tolerance{close_quotes}) to daily ozone (O{sub 3}) exposures in the laboratory is well established in healthy adult volunteers. However, the capability of asthmatics to develop tolerance during multiday ozone exposures in unclear. We exposed 10 adult volunteers with mild asthma to 0.4 ppm O{sub 3} in filtered air for 3 h/d on 5 consecutive d. Two similar filtered-air exposures during the preceding week served as controls. Follow-up O{sub 3} exposures were performed 4 and 7 d after the most recent consecutive exposure. All exposures were performed in an environmental chamber at 31 {degrees}C and 35% relative humidity. The subjects performed moderate exercise (mean ventilation rate of 32 l/min) for 15 min of each half-hour. Responses were measured with spirometry and symptom evaluations before and after each exposure, and a bronchial reactivity test (methacholine challenge) was conducted after each exposure. All response measurements showed clinically and statistically significant day-to-day variation. Symptom and forced-expiratory-volume-in-1-s responses were similarly large on the 1st and 2nd O{sub 3} exposure days, after which they diminished progressively, approaching filtered air response levels by the 5th consecutive O{sub 3} day. This tolerance was partially lost 4 and 7 d later. Bronchial reactivity peaked after the first O{sub 3} exposure and remained somewhat elevated after all subsequent O{sub 3} exposures, relative to its control level following filtered-air exposures. Individual responses varied widely; more severe initial responses to O{sub 3} predicted less rapid attenuation. We concluded that asthmatics can develop tolerance to frequent high-level O{sub 3} exposures in much the same manner as normal subjects, although the process may be slower and less fully effective in asthmatics. 27 refs., 3 figs., 4 tabs.

  18. Hippocampal Dysfunction Provoked by Mercury Chloride Exposure: Evaluation of Cognitive Impairment, Oxidative Stress, Tissue Injury and Nature of Cell Death

    Directory of Open Access Journals (Sweden)

    Walessa Alana Bragança Aragão

    2018-01-01

    Full Text Available Mercury (Hg is a highly toxic metal, which can be found in its inorganic form in the environment. This form presents lower liposolubility and lower absorption in the body. In order to elucidate the possible toxicity of inorganic Hg in the hippocampus, we investigated the potential of low doses of mercury chloride (HgCl2 to promote hippocampal dysfunction by employing a chronic exposure model. For this, 56 rats were exposed to HgCl2 (0.375 mg/kg/day via the oral route for 45 days. After the exposure period, the animals were submitted to the cognitive test of fear memory. The hippocampus was collected for the measurement of total Hg levels, analysis of oxidative stress, and evaluation of cytotoxicity, apoptosis, and tissue injury. It was observed that chronic exposure to inorganic Hg promotes an increase in mercury levels in this region and damage to short- and long-term memory. Furthermore, we found that this exposure model provoked oxidative stress, which led to cytotoxicity and cell death by apoptosis, affecting astrocytes and neurons in the hippocampus. Our study demonstrated that inorganic Hg, even with its low liposolubility, is able to produce deleterious effects in the central nervous system, resulting in cognitive impairment and hippocampal damage when administered for a long time at low doses in rats.

  19. Effect of lead exposure on spatial learning and running speed in the short-tailed opossum, Monodelphis domestica (Didelphidae).

    Science.gov (United States)

    Punzo, F; Farmer, C

    2004-01-01

    Studies were conducted to assess the spatial learning ability in adult males of the short-tailed opossum, Monodelphis domestica using a T-maze, complex maze and elevated radial 8-arm maze. This is the first study of maze learning in opossums. In the T-maze, the performance of these animals improved over an 8-day training period. Eighty percent of the subjects initially trained to turn to the right for food reinforcement reached criterion (80% correct responses) by day 3 and all reached criterion by day 4. Reversal training (subjects then trained to turn to the left) was more difficult and required 8 days for all subjects to reach criterion. In the complex maze, 89% of the animals achieved the criterion level of performance (3 consecutive trials with 5 or fewer errors) on the eighth day of training and all reached criterion by day 10. The relative importance of intramaze vs. extramaze cues in directing choice behavior was investigated in the radial arm maze. A discrimination procedure was used which selectively rewarded subjects for following only one set of cues. Animals in the intramaze group obtained a food pellet from a cup at the end of each arm. In the extramaze group, the food cups were placed on a small platform just beyond the end of each arm. All subjects were initially trained to visit each arm with the maze in a fixed position (controls) and did so within 15 test sessions. Following these initial trials, the maze was rotated to a different position after each choice. For subjects in the intramaze group, the food moved in conjunction with the rotation of the arms thereby increasing the relevance of intramaze cues. In the extramaze group, extramaze cues became more important because the food remained on the platforms in the same position in the room. Animals in the extramaze group performed significantly better than chance whereas the intramaze subjects did not. This indicates that intramaze cues are not as important as extramaze cues for accurate choice

  20. Day-to-day correlation of equatorial electrojet at two stations separated by 2000 km

    Directory of Open Access Journals (Sweden)

    R. G. Rastogi

    2007-05-01

    Full Text Available Day-to-day fluctuations of the daily range of the geomagnetic field H at the equatorial electrojet stations Ancon (ANC, 77.0° W and Sao Luis (SLZ, 44.2° W are described for the period January–June 1993. The H field started increasing between midnight and sunrise, reaching a peak shortly before noon. The daily range of H was maximum during March and April and minimum during June. Regardless of the month, the range in H was significantly larger at ANC than at SLZ. The 27-day running mean of the range of H varied from 80 nT to 125 nT at SLZ and from 105 nT to 180 nT at ANC. The day-to-day values of the range of H showed very faithful variations at the two stations. The deviations of the daily range of H from its 27-day running mean values showed good correlation between the two stations. Some large storm-time effects were seen at both stations. The correlation was still significant, when data were corrected for Dst index values. It is suggested that the range in H at the two electrojet stations, separated by more than 2000 km, are affected by some common sources other than the ring current, which need to be identified. Spectral analysis of the range of H shows remarkable similarity at the two stations, with a dominant period of 15 days at both stations.

  1. Pre-exposure Prophylaxis Use by Breastfeeding HIV-Uninfected Women: A Prospective Short-Term Study of Antiretroviral Excretion in Breast Milk and Infant Absorption.

    Directory of Open Access Journals (Sweden)

    Kenneth K Mugwanya

    2016-09-01

    Full Text Available As pre-exposure prophylaxis (PrEP becomes more widely used in heterosexual populations, an important consideration is its safety in infants who are breastfed by women taking PrEP. We investigated whether tenofovir and emtricitabine are excreted into breast milk and then absorbed by the breastfeeding infant in clinically significant concentrations when used as PrEP by lactating women.We conducted a prospective short-term, open-label study of daily oral emtricitabine-tenofovir disoproxil fumarate PrEP among 50 HIV-uninfected breastfeeding African mother-infant pairs between 1-24 wk postpartum (ClinicalTrials.gov Identifier: NCT02776748. The primary goal was to quantify the steady-state concentrations of tenofovir and emtricitabine in infant plasma ingested via breastfeeding. PrEP was administered to women through daily directly observed therapy (DOT for ten consecutive days and then discontinued thereafter. Non-fasting peak and trough samples of maternal plasma and breast milk were obtained at drug concentration steady states on days 7 and 10, and a single infant plasma sample was obtained on day 7. Peak blood and breast milk samples were obtained 1-2 h after the maternal DOT PrEP dose, while maternal trough samples were obtained at the end of the PrEP dosing interval (i.e., 23 to 24 h after maternal DOT PrEP dose. Tenofovir and emtricitabine concentrations were quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS assays. Of the 50 mother-infant pairs enrolled, 48% were ≤12 wk and 52% were 13-24 wk postpartum, and median maternal age was 25 y (interquartile range [IQR] 22-28. During study follow-up, the median (IQR daily reported frequency of infant breastfeeding was 15 times (12 to 18 overall, 16 (14 to 19 for the ≤12 weeks, and 14 (12 to 17 for the 13-24 wk infant age groups. Overall, median (IQR time-averaged peak concentrations in breast milk were 3.2 ng/mL (2.3 to 4.7 for tenofovir and 212.5 ng/mL (140.0 to 405.0 for

  2. Exposure-response functions for health effects of air pollutants based on epidemiological findings

    Energy Technology Data Exchange (ETDEWEB)

    Aunan, K

    1995-10-01

    The objective of this report is to provide exposure-response functions for health effects and air pollution, which can be used in cost-effectiveness analyses of abatement measures. When cost-effective abatement strategies for air pollution are analyzed, and when air quality standards are set, it is important to have quantitative knowledge about health damage. In spite of their shortcomings, epidemiological studies provide a sound basis for exposure-response functions because they involve a random cross section of the population. In this report the exposure-response functions apply to the relation between air pollutant concentrations and relative effect frequencies, and involve the following health effect end-points: acute and chronic respiratory symptoms in children and adults, asthma episodes in children and adults, eye irritations, headache, lung damage in children, excess mortality, lung cancer incidence. The effects are attributed to one indicator component, which in many cases is particles, but for some effects NO{sub 2}, SO{sub 2}, O{sub 3}, or CO. A calculation procedure is suggested which makes it possible to estimate excess annual symptom-days for short-term effects using the annual average concentration. 103 refs., 1 table

  3. Stress response in rat brain after different durations of noise exposure.

    Science.gov (United States)

    Samson, James; Sheeladevi, Rathinasamy; Ravindran, Rajan; Senthilvelan, Manohar

    2007-01-01

    The alteration in the levels of plasma corticosterone, brain norepinephrine (NE), and expression of brain heat shock proteins (Hsp70) after different durations of noise exposure (acute, 1 day; sub-acute, 15 days; chronic, 30 days) has been studied to analyze their role in combating time-dependent stress effects of noise. Broadband white noise (100dB) exposure to male Wistar albino rats significantly increased the levels of plasma corticosterone and NE in all three durations of noise exposure. The sustained increase observed in their levels in the chronic group suggests that animals are not getting adapted to noise even after 30 days of exposure. The important role of Hsp70 in combating noise induced stress is evident from the significant increase in its expression after chronic exposure, while there was a reciprocal decrease in the NE and corticosterone when compared with their levels after acute and sub-acute noise exposure. This clearly indicates that the time-dependent stress response to noise exposure is a complex mechanism involving highly interconnected systems such as hypothalamo-pituitary-adrenal (HPA) axis, heat shock proteins and may have serious implications in vital organs, particularly in the brain when there is a prolonged noise exposure.

  4. Application of MOSFET detectors for dosimetry in small animal radiography using short exposure times.

    Science.gov (United States)

    De Lin, Ming; Toncheva, Greta; Nguyen, Giao; Kim, Sangroh; Anderson-Evans, Colin; Johnson, G Allan; Yoshizumi, Terry T

    2008-08-01

    Digital subtraction angiography (DSA) X-ray imaging for small animals can be used for functional phenotyping given its ability to capture rapid physiological changes at high spatial and temporal resolution. The higher temporal and spatial requirements for small-animal imaging drive the need for short, high-flux X-ray pulses. However, high doses of ionizing radiation can affect the physiology. The purpose of this study was to verify and apply metal oxide semiconductor field effect transistor (MOSFET) technology to dosimetry for small-animal diagnostic imaging. A tungsten anode X-ray source was used to expose a tissue-equivalent mouse phantom. Dose measurements were made on the phantom surface and interior. The MOSFETs were verified with thermoluminescence dosimeters (TLDs). Bland-Altman analysis showed that the MOSFET results agreed with the TLD results (bias, 0.0625). Using typical small animal DSA scan parameters, the dose ranged from 0.7 to 2.2 cGy. Application of the MOSFETs in the small animal environment provided two main benefits: (1) the availability of results in near real-time instead of the hours needed for TLD processes and (2) the ability to support multiple exposures with different X-ray techniques (various of kVp, mA and ms) using the same MOSFET. This MOSFET technology has proven to be a fast, reliable small animal dosimetry method for DSA imaging and is a good system for dose monitoring for serial and gene expression studies.

  5. Age-dependent acute interference with stem and progenitor cell proliferation in the hippocampus after exposure to 1800 MHz electromagnetic radiation.

    Science.gov (United States)

    Xu, Falin; Bai, Qiongdan; Zhou, Kai; Ma, Li; Duan, Jiajia; Zhuang, Fangli; Xie, Cuicui; Li, Wenli; Zou, Peng; Zhu, Changlian

    2017-01-01

    To investigate the effects of exposure to an 1800 MHz electromagnetic field on cell death and cell proliferation in the developing brain, postnatal day 7 (P7) and P21 healthy Kunming mice were randomly assigned into the experimental and control groups. The experimental groups were exposed to an 1800 MHz electromagnetic field for 8 h daily for three consecutive days. The thymidine analog 5-bromo-2-deoxyuridine (BrdU) was injected intraperitoneally 1 h before each exposure session, and all animals were sacrificed 24 h after the last exposure. Cell death and proliferation markers were detected by immunohistochemistry in the dentate gyrus of the hippocampus. Electromagnetic exposure has no influence on cell death in the dentate gyrus of the hippocampus in P7 and P21 mice as indicated by active caspase-3 immunostaining and Fluoro-Jade labeling. The basal cell proliferation in the hippocampus was higher in P7 than in P21 mice as indicated by the number of cells labeled with BrdU and by immunohistochemical staining for phosphor-histone H3 (PHH3) and brain lipid-binding protein (BLBP). Electromagnetic exposure stimulated DNA synthesis in P7 neural stem and progenitor cells, but reduced cell division and the total number of stem cells in the hippocampus as indicated by increased BrdU labeling and reduced PHH3 and BLBP labeling compared to P7 control mice. There were no significant changes in cell proliferation in P21 mice after exposure to the electromagnetic field. These results indicate that interference with stem cell proliferation upon short-term exposure to an 1800 MHz electromagnetic field depends on the developmental stage of the brain.

  6. Laparoscopic and open subtotal colectomies have similar short-term results.

    Science.gov (United States)

    Hoogenboom, Froukje J; Bosker, Robbert J I; Groen, Henk; Meijerink, Wilhelmus J H J; Lamme, Bas; Pierie, Jean Pierre E N

    2013-01-01

    Laparoscopic subtotal colectomy (STC) is a complex procedure. It is possible that short-term benefits for segmental resections cannot be attributed to this complex procedure. This study aims to assess differences in short-term results for laparoscopic versus open STC during a 15-year single-institute experience. We reviewed consecutive patients undergoing laparoscopic or open elective or subacute STC from January 1997 to December 2012. Fifty-six laparoscopic and 50 open STCs were performed. The operation time was significantly longer in the laparoscopic group, median 266 min (range 121-420 min), compared to 153 min (range 90-408 min) in the open group (p < 0.001). Median hospital stay showed no statistical difference, 14 days (range 1-129 days) in the laparoscopic and 13 days (range 1-85 days) in the open group. Between-group postoperative complications were not statistically different. Laparoscopic STC has short-term results similar to the open procedure, except for a longer operation time. The laparoscopic approach for STC is therefore only advisable in selected patients combined with extensive preoperative counseling. Copyright © 2013 S. Karger AG, Basel.

  7. Cadmium sensitivity, uptake, subcellular distribution and thiol induction in a marine diatom: Exposure to cadmium

    International Nuclear Information System (INIS)

    Wang Mengjiao; Wang Wenxiong

    2011-01-01

    The aims of this study were to (1) evaluate the changes in the Cd tolerance of a marine diatom after exposure under different Cd concentrations for various durations and (2) to explore the potential subcellular and biochemical mechanisms underlying these changes. The 72-h toxicity, short-term Cd uptake, subcellular Cd distribution, as well as the synthesis of phytochelatins (PCs) were measured in a marine diatom Thalassiosira nordenskioeldii after exposure to a range of free Cd ion concentrations ([Cd 2+ ], 0.01-84 nM) for 1-15 days. Surprisingly, the diatoms did not acquire higher resistance to Cd after exposure; instead their sensitivity to Cd increased with a higher exposed [Cd 2+ ] and a longer exposure period. The underlying mechanisms could be traced to the responses of Cd cellular accumulation and the intrinsic detoxification ability of the preconditioned diatoms. Generally, exposure to a higher [Cd 2+ ] and for a longer period increased the Cd uptake rate, cellular accumulation, as well as the Cd concentration in metal-sensitive fraction (MSF) in these diatoms. In contrast, although PCs were induced by the environmental Cd stress (with PC 2 being the most affected), the increased intracellular Cd to PC-SH ratio implied that the PCs' detoxification ability had reduced after Cd exposure. All these responses resulted in an elevated Cd sensitivity as exposed [Cd 2+ ] and duration increased. This study shows that the physiological/biochemical and kinetic responses of phytoplankton upon metal exposure deserve further investigation.

  8. Variability of benzene exposure among filling station attendants

    International Nuclear Information System (INIS)

    Carere, A.; Iacovella, N.; Turrio Baldassarri, L.; Fuselli, S.; Iavarone, I.; Lagorio, S.; Proietto, A.R.

    1996-12-01

    A monitoring survey of filling station attendants aimed at identifying sources of variability of exposure to benzene and other aromatics was carried out. Concurrent samples of the worker's breathing zone air, atmospheric air in the service station proximity, and gasoline were collected, along with information about daily workloads and other exposure-related factors. Benzene personal exposure was characterised by a small between-worker variability and a predominant within-worker variance component. Such elevated day-to-day variability yields to imprecise estimates of mean personal exposure. Almost 70% of the overall personal exposure variance was explained by a model including daily benzene from dispensed fuel, presence of a shelter over the refueling area, amount of fuel supplied to the station if a delivery occurred, and background atmospheric benzene concentration

  9. Double blind placebo controlled exposure to molds

    DEFF Research Database (Denmark)

    Meyer, H W; Jensen, K A; Nielsen, K F

    2005-01-01

    non-significant, and at the same level as after placebo exposure. The developed exposure system based on the Particle-Field and Laboratory Emission Cell (P-FLEC) makes it possible to deliver a precise and highly controlled dose of mold spores from water-damaged building materials, imitating realistic......The objective was to develop an experimental setup for human exposure to mold spores, and to study the clinical effect of this exposure in sensitive subjects who had previously experienced potentially building-related symptoms (BRS) at work. From three water-damaged schools eight employees....... In conclusion this is, to our knowledge, the first study to successfully conduct a human exposure to a highly controlled dose of fungal material aerosolized directly from wet building materials. This short-term exposure to high concentrations of two different molds induced no more reactions than exposure...

  10. Vast Portfolio Selection with Gross-exposure Constraints*

    Science.gov (United States)

    Fan, Jianqing; Zhang, Jingjin; Yu, Ke

    2012-01-01

    We introduce the large portfolio selection using gross-exposure constraints. We show that with gross-exposure constraint the empirically selected optimal portfolios based on estimated covariance matrices have similar performance to the theoretical optimal ones and there is no error accumulation effect from estimation of vast covariance matrices. This gives theoretical justification to the empirical results in Jagannathan and Ma (2003). We also show that the no-short-sale portfolio can be improved by allowing some short positions. The applications to portfolio selection, tracking, and improvements are also addressed. The utility of our new approach is illustrated by simulation and empirical studies on the 100 Fama-French industrial portfolios and the 600 stocks randomly selected from Russell 3000. PMID:23293404

  11. Cement dust exposure and acute lung function: A cross shift study

    Directory of Open Access Journals (Sweden)

    Moen Bente E

    2010-04-01

    Full Text Available Abstract Background Few studies have been carried out on acute effects of cement dust exposure. This study is conducted to investigate the associations between current "total" dust exposure and acute respiratory symptoms and respiratory function among cement factory workers. Methods A combined cross-sectional and cross-shift study was conducted in Dire Dawa cement factory in Ethiopia. 40 exposed production workers from the crusher and packing sections and 20 controls from the guards were included. Personal "total" dust was measured in the workers' breathing zone and peak expiratory flow (PEF was measured for all selected workers before and after the shift. When the day shift ended, the acute respiratory symptoms experienced were scored and recorded on a five-point Likert scale using a modified respiratory symptom score questionnaire. Results The highest geometric mean dust exposure was found in the crusher section (38.6 mg/m3 followed by the packing section (18.5 mg/m3 and the guards (0.4 mg/m3. The highest prevalence of respiratory symptoms for the high exposed workers was stuffy nose (85% followed by shortness of breath (47% and "sneezing" (45%. PEF decreased significantly across the shift in the high exposed group. Multiple linear regression showed a significant negative association between the percentage cross-shift change in PEF and total dust exposure. The number of years of work in high-exposure sections and current smoking were also associated with cross-shift decrease in PEF. Conclusions Total cement dust exposure was related to acute respiratory symptoms and acute ventilatory effects. Implementing measures to control dust and providing adequate personal respiratory protective equipment for the production workers are highly recommended.

  12. Desert Dust Outbreaks in Southern Europe: Contribution to Daily PM10 Concentrations and Short-Term Associations with Mortality and Hospital Admissions

    Science.gov (United States)

    Stafoggia, Massimo; Zauli-Sajani, Stefano; Pey, Jorge; Samoli, Evangelia; Alessandrini, Ester; Basagaña, Xavier; Cernigliaro, Achille; Chiusolo, Monica; Demaria, Moreno; Díaz, Julio; Faustini, Annunziata; Katsouyanni, Klea; Kelessis, Apostolos G.; Linares, Cristina; Marchesi, Stefano; Medina, Sylvia; Pandolfi, Paolo; Pérez, Noemí; Querol, Xavier; Randi, Giorgia; Ranzi, Andrea; Tobias, Aurelio; Forastiere, Francesco

    2015-01-01

    Background: Evidence on the association between short-term exposure to desert dust and health outcomes is controversial. Objectives: We aimed to estimate the short-term effects of particulate matter ≤ 10 μm (PM10) on mortality and hospital admissions in 13 Southern European cities, distinguishing between PM10 originating from the desert and from other sources. Methods: We identified desert dust advection days in multiple Mediterranean areas for 2001–2010 by combining modeling tools, back-trajectories, and satellite data. For each advection day, we estimated PM10 concentrations originating from desert, and computed PM10 from other sources by difference. We fitted city-specific Poisson regression models to estimate the association between PM from different sources (desert and non-desert) and daily mortality and emergency hospitalizations. Finally, we pooled city-specific results in a random-effects meta-analysis. Results: On average, 15% of days were affected by desert dust at ground level (desert PM10 > 0 μg/m3). Most episodes occurred in spring–summer, with increasing gradient of both frequency and intensity north–south and west–east of the Mediterranean basin. We found significant associations of both PM10 concentrations with mortality. Increases of 10 μg/m3 in non-desert and desert PM10 (lag 0–1 days) were associated with increases in natural mortality of 0.55% (95% CI: 0.24, 0.87%) and 0.65% (95% CI: 0.24, 1.06%), respectively. Similar associations were estimated for cardio-respiratory mortality and hospital admissions. Conclusions: PM10 originating from the desert was positively associated with mortality and hospitalizations in Southern Europe. Policy measures should aim at reducing population exposure to anthropogenic airborne particles even in areas with large contribution from desert dust advections. Citation: Stafoggia M, Zauli-Sajani S, Pey J, Samoli E, Alessandrini E, Basagaña X, Cernigliaro A, Chiusolo M, Demaria M, Díaz J, Faustini A

  13. Desert Dust Outbreaks in Southern Europe: Contribution to Daily PM₁₀ Concentrations and Short-Term Associations with Mortality and Hospital Admissions.

    Science.gov (United States)

    Stafoggia, Massimo; Zauli-Sajani, Stefano; Pey, Jorge; Samoli, Evangelia; Alessandrini, Ester; Basagaña, Xavier; Cernigliaro, Achille; Chiusolo, Monica; Demaria, Moreno; Díaz, Julio; Faustini, Annunziata; Katsouyanni, Klea; Kelessis, Apostolos G; Linares, Cristina; Marchesi, Stefano; Medina, Sylvia; Pandolfi, Paolo; Pérez, Noemí; Querol, Xavier; Randi, Giorgia; Ranzi, Andrea; Tobias, Aurelio; Forastiere, Francesco

    2016-04-01

    Evidence on the association between short-term exposure to desert dust and health outcomes is controversial. We aimed to estimate the short-term effects of particulate matter ≤ 10 μm (PM10) on mortality and hospital admissions in 13 Southern European cities, distinguishing between PM10 originating from the desert and from other sources. We identified desert dust advection days in multiple Mediterranean areas for 2001-2010 by combining modeling tools, back-trajectories, and satellite data. For each advection day, we estimated PM10 concentrations originating from desert, and computed PM10 from other sources by difference. We fitted city-specific Poisson regression models to estimate the association between PM from different sources (desert and non-desert) and daily mortality and emergency hospitalizations. Finally, we pooled city-specific results in a random-effects meta-analysis. On average, 15% of days were affected by desert dust at ground level (desert PM10 > 0 μg/m3). Most episodes occurred in spring-summer, with increasing gradient of both frequency and intensity north-south and west-east of the Mediterranean basin. We found significant associations of both PM10 concentrations with mortality. Increases of 10 μg/m3 in non-desert and desert PM10 (lag 0-1 days) were associated with increases in natural mortality of 0.55% (95% CI: 0.24, 0.87%) and 0.65% (95% CI: 0.24, 1.06%), respectively. Similar associations were estimated for cardio-respiratory mortality and hospital admissions. PM10 originating from the desert was positively associated with mortality and hospitalizations in Southern Europe. Policy measures should aim at reducing population exposure to anthropogenic airborne particles even in areas with large contribution from desert dust advections. Stafoggia M, Zauli-Sajani S, Pey J, Samoli E, Alessandrini E, Basagaña X, Cernigliaro A, Chiusolo M, Demaria M, Díaz J, Faustini A, Katsouyanni K, Kelessis AG, Linares C, Marchesi S, Medina S, Pandolfi P, P

  14. Short-term effect of fine particulate air pollution on daily mortality: a case-crossover study in a tropical city, Kaohsiung, Taiwan.

    Science.gov (United States)

    Tsai, Shang-Shyue; Chen, Chih-Cheng; Yang, Chun-Yuh

    2014-01-01

    Many studies have examined the short-term effects of air pollution on frequency of daily mortality over the past two decades. However, information on the relationship between levels of fine particles (PM(2.5)) and daily mortality is relatively sparse due to limited availability of monitoring data. Further the results are inconsistent. This study was undertaken to determine whether there was an association between PM(2.5) levels and daily mortality rate in Kaohsiung, Taiwan, a large industrial city with a tropical climate. Daily mortality rate, air pollution parameters, and weather data for Kaohsiung were obtained for the period from 2006 through 2008. The relative risk of daily mortality occurrence was estimated using a time-stratified case-crossover approach, controlling for (1) weather variables, (2) day of the week, (3) seasonality, and (4) long-term time trends. For the single-pollutant model (without adjustment for other pollutants), no significant effects were found between PM(2.5) and frequency of daily mortality on warm days (≥25°C). On cool days, PM(2.5) showed significant correlation with increased risk of mortality rate for all causes and circulatory diseases in single-pollutant model. There was no indication of an association between PM(2.5) and deaths due to respiratory diseases. The relationship appeared to be stronger on cool days. This study provided evidence of associations between short-term exposure to PM(2.5) and elevated risk of death for all cause and circulatory diseases.

  15. Does short-term exposure to mobile phone base station signals increase symptoms in individuals who report sensitivity to electromagnetic fields? A double-blind randomized provocation study.

    Science.gov (United States)

    Eltiti, Stacy; Wallace, Denise; Ridgewell, Anna; Zougkou, Konstantina; Russo, Riccardo; Sepulveda, Francisco; Mirshekar-Syahkal, Dariush; Rasor, Paul; Deeble, Roger; Fox, Elaine

    2007-11-01

    Individuals with idiopathic environmental illness with attribution to electromagnetic fields (IEI-EMF) believe they suffer negative health effects when exposed to electromagnetic fields from everyday objects such as mobile phone base stations. This study used both open provocation and double-blind tests to determine if sensitive and control individuals experience more negative health effects when exposed to base station-like signals compared with sham. Fifty-six self-reported sensitive and 120 control participants were tested in an open provocation test. Of these, 12 sensitive and 6 controls withdrew after the first session. The remainder completed a series of double-blind tests. Subjective measures of well-being and symptoms as well as physiological measures of blood volume pulse, heart rate, and skin conductance were obtained. During the open provocation, sensitive individuals reported lower levels of well-being in both the global system for mobile communication (GSM) and universal mobile telecommunications system (UMTS) compared with sham exposure, whereas controls reported more symptoms during the UMTS exposure. During double-blind tests the GSM signal did not have any effect on either group. Sensitive participants did report elevated levels of arousal during the UMTS condition, whereas the number or severity of symptoms experienced did not increase. Physiological measures did not differ across the three exposure conditions for either group. Short-term exposure to a typical GSM base station-like signal did not affect well-being or physiological functions in sensitive or control individuals. Sensitive individuals reported elevated levels of arousal when exposed to a UMTS signal. Further analysis, however, indicated that this difference was likely to be due to the effect of order of exposure rather than the exposure itself.

  16. Chronic ethanol exposure increases voluntary home cage intake in adult male, but not female, Long-Evans rats.

    Science.gov (United States)

    Morales, Melissa; McGinnis, Molly M; McCool, Brian A

    2015-12-01

    The current experiment examined the effects of 10 days of chronic intermittent ethanol (CIE) exposure on anxiety-like behavior and home cage ethanol intake using a 20% intermittent access (M, W, F) paradigm in male and female Long-Evans rats. Withdrawal from alcohol dependence contributes to relapse in humans and increases in anxiety-like behavior and voluntary ethanol consumption in preclinical models. Our laboratory has shown that 10 days of CIE exposure produces both behavioral and neurophysiological alterations associated with withdrawal in male rats; however, we have yet to examine the effects of this exposure regime on ethanol intake in females. During baseline, females consumed more ethanol than males but, unlike males, did not show escalations in intake. Rats were then exposed to CIE and were again given intermittent access to 20% ethanol. CIE males increased their intake compared to baseline, whereas air-exposed males did not. Ethanol intake in females was unaffected by CIE exposure. Notably, both sexes expressed significantly elevated withdrawal-associated anxiety-like behavior in the plus maze. Finally, rats were injected with the cannabinoid CB1 receptor antagonist, SR141716A (0, 1, 3, 10mg/kg, i.p.) which reduced ethanol intake in both sexes. However, females appear to be more sensitive to lower doses of this CB1 receptor antagonist. Our results show that females consume more ethanol than males; however, they did not escalate their intake using the intermittent access paradigm. Unlike males, CIE exposure had no effect on drinking in females. It is possible that females may be less sensitive than males to ethanol-induced increases in drinking after a short CIE exposure. Lastly, our results demonstrate that males and females may have different pharmacological sensitivities to CB1 receptor blockade on ethanol intake, at least under the current conditions. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Effect of continuous gamma-ray exposure on performance of learned tasks and effect of subsequent fractionated exposures on blood-forming tissue

    Science.gov (United States)

    Spalding, J. F.; Holland, L. M.; Prine, J. R.; Farrer, D. N.; Braun, R. G.

    1972-01-01

    Sixteen monkeys trained to perform continuous and discrete-avoidance and fixed-ratio tasks with visual and auditory cues were performance-tested before, during, and after 10-day gamma-ray exposures totaling 0, 500, 750, and 1000 rads. Approximately 14 months after the performance-test exposures, surviving animals were exposed to 100-rad gamma-ray fractions at 56-day intervals to observe injury and recovery patterns of blood-forming tissues. The fixed-ratio, food-reward task performance showed a transient decline in all dose groups within 24 hours of the start of gamma-ray exposure, followed by recovery to normal food-consumption levels within 48 to 72 hours. Avoidance tasks were performed successfully by all groups during the 10-day exposure, but reaction times of the two higher dose-rate groups in which animals received 3 and 4 rads per hour or total doses of 750 and 1000 rads, respectively, were somewhat slower.

  18. Hydration and transparency of the rabbit cornea irradiated with UVB-doses of 0.25 J/cm(2) and 0.5 J/cm(2) compared with equivalent UVB radiation exposure reaching the human cornea from sunlight.

    Science.gov (United States)

    Cejka, Cestmír; Ardan, Taras; Sirc, Jakub; Michálek, Jiří; Beneš, Jiří; Brůnová, Blanka; Rosina, Jozef

    2011-07-01

    Exposure of the cornea to UV radiation from sunlight evokes intraocular inflammation, photokeratitis. Photokeratitis is caused by UVB radiation. It is accompanied by changes of corneal hydration and light absorption. The aim of this study was to examine the effect of two UVB doses on corneal optics in rabbits and to compare these UVB doses with the equivalent exposure of UVB radiation reaching the human cornea from sunlight. Rabbit corneas were irradiated with a daily UVB dose of 0.25 J/cm(2) or 0.5 J/cm(2) for 4 days. One day after finishing the irradiations the rabbits were sacrificed and corneal light absorption measured using our spectrophotometrical method. Corneal hydration was examined using an ultrasonic Pachymeter every experimental day before the irradiation procedure and the last day before sacrificing the animals. Changes in corneal optics appeared after the repeated exposure of the cornea to a UVB dose of 0.25 J/ cm(2) and massively increased after the repeated exposure of the cornea to a UVB dose of 0.5 J/cm(2). The first significant changes in corneal hydration appeared after a single exposure of the cornea to a UVB dose of 0.25 J/cm(2). Changes in corneal hydration appeared after the exposure of the rabbit cornea to a single UVB dose equivalent to 2.6 hours of solar UVB radiation reaching the human cornea, as measured by UVB sensors embedded in the eyes of mannequin heads facing the sun on a beach at noon in July. Repeated exposure of the rabbit cornea to the same UVB dose evoked profound changes in corneal optics. Although comparison of experimental and outdoor conditions are only approximate, the results in rabbits point to the danger for the human eye from UVB radiation when short stays in sunlight are repeated for several consecutive days without UV protection.

  19. Monte-Carlo and multi-exposure assessment for the derivation of criteria for disinfection byproducts and volatile organic compounds in drinking water: Allocation factors and liter-equivalents per day.

    Science.gov (United States)

    Akiyama, Megumi; Matsui, Yoshihiko; Kido, Junki; Matsushita, Taku; Shirasaki, Nobutaka

    2018-06-01

    The probability distributions of total potential doses of disinfection byproducts and volatile organic compounds via ingestion, inhalation, and dermal exposure were estimated with Monte Carlo simulations, after conducting physiologically based pharmacokinetic model simulations to takes into account the differences in availability between the three exposures. If the criterion that the 95th percentile estimate equals the TDI (tolerable daily intake) is regarded as protecting the majority of a population, the drinking water criteria would be 140 (trichloromethane), 66 (bromodichloromethane), 157 (dibromochloromethane), 203 (tribromomethane), 140 (dichloroacetic acid), 78 (trichloroacetic acid), 6.55 (trichloroethylene, TCE), and 22 μg/L (perchloroethylene). The TCE criterion was lower than the Japanese Drinking Water Quality Standard (10 μg/L). The latter would allow the intake of 20% of the population to exceed the TDI. Indirect inhalation via evaporation from water, especially in bathrooms, was the major route of exposure to compounds other than haloacetic acids (HAAs) and accounted for 1.2-9 liter-equivalents/day for the median-exposure subpopulation. The ingestion of food was a major indirect route of exposure to HAAs. Contributions of direct water intake were not very different for trihalomethanes (30-45% of TDIs) and HAAs (45-52% of TDIs). Copyright © 2018 Elsevier Inc. All rights reserved.

  20. Day-to-day relations between stress and sleep and the mediating role of perseverative cognition.

    Science.gov (United States)

    Van Laethem, Michelle; Beckers, Debby G J; van Hooff, Madelon L M; Dijksterhuis, Ap; Geurts, Sabine A E

    2016-08-01

    The goals of this longitudinal diary-based study were to shed light on the day-level relationship between stress and subsequent sleep, and to examine whether perseverative cognition is a mediating factor in this relation. A total of 44 Dutch PhD students were followed during a two-month period, from one month before their public thesis defense (ie, a stressful life event), until one month thereafter. Participants completed short evening and morning questionnaires on eight occasions (in anticipation of and following the defense), including questions about day-level stress, sleep quality, and perseverative cognition. Objective sleep parameters were collected with the SenseWear Pro Armband. Multilevel analysis was used to analyze daily observations nested within individuals. Analyses revealed that day-level stress was not directly related to subsequent subjective sleep indicators or to subsequent objective sleep indicators. Day-level stress was significantly associated with day-level perseverative cognition, and daily variations in perseverative cognition were significantly related to several day-level objective sleep parameters (sleep efficiency, marginally to number of awakenings, and wake after sleep onset), and to several day-level subjective sleep parameters (sleep quality, number of awakenings, wake after sleep onset). Finally, mediation analyses using path analysis suggested that, on the day level, perseverative cognition functions as a mediator between stress and several sleep parameters, namely, subjective sleep quality, objective sleep efficiency, and subjective wake after sleep onset. Perseverative cognition is a promising explanatory mechanism linking day-level stress to subjective and objective measures of sleep. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Comparative Transcriptomic Analysis of the Response of Dunaliella acidophila (Chlorophyta) to Short-Term Cadmium and Chronic Natural Metal-Rich Water Exposures.

    Science.gov (United States)

    Puente-Sánchez, Fernando; Olsson, Sanna; Aguilera, Angeles

    2016-10-01

    Heavy metals are toxic compounds known to cause multiple and severe cellular damage. However, acidophilic extremophiles are able to cope with very high concentrations of heavy metals. This study investigated the stress response under natural environmental heavy metal concentrations in an acidophilic Dunaliella acidophila. We employed Illumina sequencing for a de novo transcriptome assembly and to identify changes in response to high cadmium concentrations and natural metal-rich water. The photosynthetic performance was also estimated by pulse amplitude-modulated (PAM) fluorescence. Transcriptomic analysis highlights a number of processes mainly related to a high constitutive expression of genes involved in oxidative stress and response to reactive oxygen species (ROS), even in the absence of heavy metals. Photosynthetic activity seems to be unaltered under short-term exposition to Cd and chronic exposure to natural metal-rich water, probably due to an increase in the synthesis of structural photosynthetic components preserving their functional integrity. An overrepresentation of Gene Ontology (GO) terms related to metabolic activities, transcription, and proteosomal catabolic process was observed when D. acidophila grew under chronic exposure to natural metal-rich water. GO terms involved in carbohydrate metabolic process, reticulum endoplasmic and Golgi bodies, were also specifically overrepresented in natural metal-rich water library suggesting an endoplasmic reticulum stress response.

  2. Chronic exposure to chlorpyrifos reveals two modes of action in the springtail Folsomia candida.

    Science.gov (United States)

    Jager, Tjalling; Crommentuijn, Trudie; van Gestel, Cornelis A M; Kooijman, Sebastiaan A L M

    2007-01-01

    Organophosphates are popular insecticides, but relatively little is known about their chronic effects on ecologically relevant endpoints. In this paper, we examine a life-cycle experiment with the springtail Folsomia candida, exposed via food to chlorpyrifos (CPF). The results for all endpoints (survival, growth and reproduction) were analyzed using the DEBtox model. Growth was unaffected by CPF, even at concentrations causing severe effects on survival and reproduction. Model analysis suggests that CPF directly affects the process of egg production. For the short-term response (45 days), this single mode of action accurately agreed with the data. However, the full data set (120 days) revealed a dose-related decrease in reproduction at low concentrations after prolonged exposure, not covered by the same mechanism. It appears that CPF interacts with senescence by increasing oxidative damage. This assumption fits the data well, but has little consequences for the predicted response at the population level.

  3. Effect of sequential isoproturon pulse exposure on Scenedesmus vacuolatus.

    Science.gov (United States)

    Vallotton, Nathalie; Eggen, Rik Ilda Lambertus; Chèvre, Nathalie

    2009-04-01

    Aquatic organisms are typically exposed to fluctuating concentrations of herbicides in streams. To assess the effects on algae of repeated peak exposure to the herbicide isoproturon, we subjected the alga Scenedesmus vacuolatus to two sequential pulse exposure scenarios. Effects on growth and on the inhibition of the effective quantum yield of photosystem II (PSII) were measured. In the first scenario, algae were exposed to short, 5-h pulses at high isoproturon concentrations (400 and 1000 microg/l), each followed by a recovery period of 18 h, while the second scenario consisted of 22.5-h pulses at lower concentrations (60 and 120 microg/l), alternating with short recovery periods (1.5 h). In addition, any changes in the sensitivity of the algae to isoproturon following sequential pulses were examined by determining the growth rate-EC(50) prior to and following exposure. In both exposure scenarios, we found that algal growth and its effective quantum yield were systematically inhibited during the exposures and that these effects were reversible. Sequential pulses to isoproturon could be considered a sequence of independent events. Nevertheless, a consequence of inhibited growth during the repeated exposures is the cumulative decrease in biomass production. Furthermore, in the second scenario, when the sequence of long pulses began to approach a scenario of continuous exposure, a slight increase in the tolerance of the algae to isoproturon was observed. These findings indicated that sequential pulses do affect algae during each pulse exposure, even if algae recover between the exposures. These observations could support an improved risk assessment of fluctuating exposures to reversibly acting herbicides.

  4. Spatiotemporal influence of temperature, air quality, and urban environment on cause-specific mortality during hazy days.

    Science.gov (United States)

    Ho, Hung Chak; Wong, Man Sing; Yang, Lin; Shi, Wenzhong; Yang, Jinxin; Bilal, Muhammad; Chan, Ta-Chien

    2018-03-01

    Haze is an extreme weather event that can severely increase air pollution exposure, resulting in higher burdens on human health. Few studies have explored the health effects of haze, and none have investigated the spatiotemporal interaction between temperature, air quality and urban environment that may exacerbate the adverse health effects of haze. We investigated the spatiotemporal pattern of haze effects and explored the additional effects of temperature, air pollution and urban environment on the short-term mortality risk during hazy days. We applied a Poisson regression model to daily mortality data from 2007 through 2014, to analyze the short-term mortality risk during haze events in Hong Kong. We evaluated the adverse effect on five types of cause-specific mortality after four types of haze event. We also analyzed the additional effect contributed by the spatial variability of urban environment on each type of cause-specific mortality during a specific haze event. A regular hazy day (lag 0) has higher all-cause mortality risk than a day without haze (odds ratio: 1.029 [1.009, 1.049]). We have also observed high mortality risks associated with mental disorders and diseases of the nervous system during hazy days. In addition, extreme weather and air quality contributed to haze-related mortality, while cold weather and higher ground-level ozone had stronger influences on mortality risk. Areas with a high-density environment, lower vegetation, higher anthropogenic heat, and higher PM 2.5 featured stronger effects of haze on mortality than the others. A combined influence of haze, extreme weather/air quality, and urban environment can result in extremely high mortality due to mental/behavioral disorders or diseases of the nervous system. In conclusion, we developed a data-driven technique to analyze the effects of haze on mortality. Our results target the specific dates and areas with higher mortality during haze events, which can be used for development of

  5. Repeated homotypic stress elevates 2-arachidonoylglycerol levels and enhances short-term endocannabinoid signaling at inhibitory synapses in basolateral amygdala.

    Science.gov (United States)

    Patel, Sachin; Kingsley, Philip J; Mackie, Ken; Marnett, Lawrence J; Winder, Danny G

    2009-12-01

    Psychosocial stress is a risk factor for development and exacerbation of neuropsychiatric illness. Repeated stress causes biochemical adaptations in endocannabinoid (eCB) signaling that contribute to stress-response habituation, however, the synaptic correlates of these adaptations have not been examined. Here, we show that the synthetic enzyme for the eCB 2-arachidonoylglycerol (2-AG), diacylglycerol (DAG) lipase alpha, is heterogeneously expressed in the amygdala, and that levels of 2-AG and precursor DAGs are increased in the basolateral amygdala (BLA) after 10 days, but not 1 day, of restraint stress. In contrast, arachidonic acid was decreased after both 1 and 10 days of restraint stress. To examine the synaptic correlates of these alterations in 2-AG metabolism, we used whole-cell electrophysiology to determine the effects of restraint stress on depolarization-induced suppression of inhibition (DSI) in the BLA. A single restraint stress exposure did not alter DSI compared with control mice. However, after 10 days of restraint stress, DSI duration, but not magnitude, was significantly prolonged. Inhibition of 2-AG degradation with MAFP also prolonged DSI duration; the effects of repeated restraint stress and MAFP were mutually occlusive. These data indicate that exposure to repeated, but not acute, stress produces neuroadaptations that confer BLA neurons with an enhanced capacity to elevate 2-AG content and engage in 2-AG-mediated short-term retrograde synaptic signaling. We suggest stress-induced enhancement of eCB-mediated suppression of inhibitory transmission in the BLA could contribute to affective dysregulation associated with chronic stress.

  6. BREATHER (PENTA 16) short-cycle therapy (SCT) (5 days on/2 days off) in young people with chronic human immunodeficiency virus infection: an open, randomised, parallel-group Phase II/III trial.

    Science.gov (United States)

    Butler, Karina; Inshaw, Jamie; Ford, Deborah; Bernays, Sarah; Scott, Karen; Kenny, Julia; Klein, Nigel; Turkova, Anna; Harper, Lynda; Nastouli, Eleni; Paparini, Sara; Choudhury, Rahela; Rhodes, Tim; Babiker, Abdel; Gibb, Diana

    2016-06-01

    For human immunodeficiency virus (HIV)-infected adolescents facing lifelong antiretroviral therapy (ART), short-cycle therapy (SCT) with long-acting agents offers the potential for drug-free weekends, less toxicity, better adherence and cost savings. To determine whether or not efavirenz (EFV)-based ART in short cycles of 5 days on and 2 days off is as efficacious (in maintaining virological suppression) as continuous EFV-based ART (continuous therapy; CT). Secondary objectives included the occurrence of new clinical HIV events or death, changes in immunological status, emergence of HIV drug resistance, drug toxicity and changes in therapy. Open, randomised, non-inferiority trial. Europe, Thailand, Uganda, Argentina and the USA. Young people (aged 8-24 years) on EFV plus two nucleoside reverse transcriptase inhibitors and with a HIV-1 ribonucleic acid level [viral load (VL)] of  12 months. Young people were randomised to continue daily ART (CT) or change to SCT (5 days on, 2 days off ART). Follow-up was for a minimum of 48 weeks (0, 4 and 12 weeks and then 12-weekly visits). The primary outcome was the difference between arms in the proportion with VL > 50 copies/ml (confirmed) by 48 weeks, estimated using the Kaplan-Meier method (12% non-inferiority margin) adjusted for region and age. In total, 199 young people (11 countries) were randomised (n = 99 SCT group, n = 100 CT group) and followed for a median of 86 weeks. Overall, 53% were male; the median age was 14 years (21% ≥ 18 years); 13% were from the UK, 56% were black, 19% were Asian and 21% were Caucasian; and the median CD4% and CD4 count were 34% and 735 cells/mm(3), respectively. By week 48, only one participant (CT) was lost to follow-up. The SCT arm had a 27% decreased drug exposure as measured by the adherence questionnaire and a MEMSCap(™) Medication Event Monitoring System (MEMSCap Inc., Durham, NC, USA) substudy (median cap openings per week: SCT group, n = 5; CT group, n

  7. Effects of different inorganic arsenic species in Cyprinus carpio (Cyprinidae) tissues after short-time exposure: Bioaccumulation, biotransformation and biological responses

    Energy Technology Data Exchange (ETDEWEB)

    Ventura-Lima, Juliane [Instituto de Ciencias Biologicas, Universidade Federal do Rio Grande - FURG, Rio Grande, RS (Brazil); Programa de Pos-Graduacao em Ciencias Fisiologicas - Fisiologia Animal Comparada (FURG), Rio Grande, RS (Brazil); Fattorini, Daniele; Regoli, Francesco [Istituto di Biologia e Genetica, Universita Politecnica delle Marche, 60100, Ancona (Italy); Monserrat, Jose M., E-mail: josemmonserrat@pesquisador.cnpq.b [Instituto de Ciencias Biologicas, Universidade Federal do Rio Grande - FURG, Rio Grande, RS (Brazil); Programa de Pos-Graduacao em Ciencias Fisiologicas - Fisiologia Animal Comparada (FURG), Rio Grande, RS (Brazil)

    2009-12-15

    Differences in the toxicological and metabolic pathway of inorganic arsenic compounds are largely unknown for aquatic species. In the present study the effects of short-time and acute exposure to As{sup III} and As{sup V} were investigated in gills and liver of the common carp, Cyprinus carpio (Cyprinidae), measuring accumulation and chemical speciation of arsenic, and the activity of glutathione-S-transferase omega (GST OMEGA), the rate limiting enzyme in biotransformation of inorganic arsenic. Oxidative biomarkers included antioxidant defenses (total glutathione-S-transferases, glutathione reductase, glutathione, and glucose-6-phosphate dehydrogenase), total scavenging capacity toward peroxyl radicals, reactive oxygen species (ROS) measurement and lipid peroxidation products. A marked accumulation of arsenic was observed only in gills of carps exposed to 1000 ppb As{sup V}. Also in gills, antioxidant responses were mostly modulated through a significant induction of glucose-6-phosphate dehydrogenase activity which probably contributed to reduce ROS formation; however this increase was not sufficient to prevent lipid peroxidation. No changes in metal content were measured in liver of exposed carps, characterized by lower activity of GST OMEGA compared to gills. On the other hand, glutathione metabolism was more sensitive in liver tissue, where a significant inhibition of glutathione reductase was concomitant with increased levels of glutathione and higher total antioxidant capacity toward peroxyl radicals, thus preventing lipid peroxidation and ROS production. The overall results of this study indicated that exposure of C. carpio to As{sup III} and As{sup V} can induce different responses in gills and liver of this aquatic organism. - Common carp (Cyprinus carpio) presented marked differences between gills and liver after arsenic exposure in terms of antioxidant responses and also in biotransformation.

  8. Does pre-exposure to warming conditions increase Mytilus galloprovincialis tolerance to Hg contamination?

    Science.gov (United States)

    Freitas, Rosa; Coppola, Francesca; Henriques, Bruno; Wrona, Fredrick; Figueira, Etelvina; Pereira, Eduarda; Soares, Amadeu M V M

    2017-12-01

    The degree to which marine invertebrate populations can tolerate extreme weather events, such as short-term exposure to high temperatures, and the underlying biochemical response mechanisms are not yet fully understood. Furthermore, scarce information is available on how marine organisms respond to the presence of pollutants after exposure to heat stress conditions. Therefore, the present study aimed to understand how the mussel Mytilus galloprovincialis responds to Hg pollution after pre-exposure to warming conditions. Mussels were exposed to control (17°C) and warming (21°C) conditions during 14days, followed by Hg contamination during 28days under different temperature regimes (17 and 21°C). The results obtained demonstrated significantly higher Hg concentrations in mussels under 17°C during the entire experiment than in organisms exposed to 21°C during the same period, which resulted in higher oxidative stress in mussels under control temperature. Significantly higher Hg concentrations were also observed in mussels pre-exposed to 21°C followed by a 17°C exposure comparing with organisms maintained the entire experiment at 21°C. These results may be explained by higher metabolic capacity in organisms exposed to 17°C after pre-exposure to 21°C that although induced antioxidant defences were not enough to prevent oxidative stress. No significant differences in terms of Hg concentration were found between mussels exposed to 17°C during the entire experiment and organisms pre-exposed to 21°C followed by a 17°C exposure, leading to similar oxidative stress levels in mussels exposed to both conditions. Therefore, our findings demonstrated that pre-exposure to warming conditions did not change mussels' accumulation and tolerance to Hg in comparison to Hg contaminated mussels maintained at control temperature. Furthermore, the present study indicate that organisms maintained under warming conditions for long periods may prevent the accumulation of

  9. CERN hearing day

    CERN Multimedia

    2005-01-01

    1 in 10 people suffer from hearing loss - do you? The Medical Service invites everyone working on the CERN site to participate in the NATIONAL HEARING DAY on: Thursday 10th March 2005 From 9am to 4pm The Infirmary, Blg. 57, Ground Floor We will be offering hearing tests (audiograms), as well as information and advice on hearing loss, tinnitus, etc. Deafness does not just affect the elderly: in Europe, 50% of the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing problems but PREVENTION IS POSSIBLE. For example, hearing protection devices can prevent 80% of tinnitus cases.

  10. CERN hearing day

    CERN Multimedia

    2005-01-01

    1 in 10 people suffer from hearing loss - do you? The Medical Service invites everyone working on CERN premises to participate in the National Hearing Day on: Thursday 10th March From 9am to 4pm The Infirmary, Blg. 57, Gr.Fl. We will be offering hearing tests (audiogram); information, advice on hearing loss, tinnitus and more. Deafness does not just affect the elderly: in Europe, 50% the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing loss. But PREVENTION IS POSSIBLE AND EFFECTIVE: for example, Hearing protection devices could reduce tinnitus cases by 80%.

  11. CERN hearing day

    CERN Document Server

    2005-01-01

    1 in 10 people suffer from hearing loss - do you? The Medical Service invites everyone working on CERN premises to participate in the National Hearing Day on: Thursday 10th March From 9am to 4pm The Infirmary, Blg. 57, Gr.Fl. We will be offering hearing tests (audiogram); information, advice on hearing loss, tinnitus and more. Deafness does not just affect the elderly: in Europe, 50% the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing loss. But prevention is possible and effective: for example, Hearing protection devices could reduce tinnitus cases by 80%.

  12. CERN hearing day

    CERN Multimedia

    2005-01-01

    1 in 10 people suffer from hearing loss ? do you? The Medical Service invites everyone working on the CERN site to participate in the NATIONAL HEARING DAY on: Thursday 10th March 2005 From 9am to 4pm The Infirmary, Blg. 57, Ground Floor We will be offering hearing tests (audiograms), as well as information and advice on hearing loss, tinnitus, etc. Deafness does not just affect the elderly: in Europe, 50% of the hearing-impaired are under the age of 55. Exposure to excessive noise is one of the main reasons for hearing problems but prevention is possible. For example, hearing protection devices can prevent 80% of tinnitus cases.

  13. Effects of noise exposure on catalase activity of growing lymphocytes

    Directory of Open Access Journals (Sweden)

    Syed Kashif Nawaz

    2012-11-01

    Full Text Available Oxidative stress due to noise was estimated at cell level using model of growing lymphocytes. Lymphocytes were isolated and cultured using conventional methodology. Cell culture of each group was exposed to sound of frequency 1 KHz during incubation. Three groups were defined on the basis of exposure of sound with specific range of intensity and duration of exposure. Group A and Group B were exposed to sound with intensity 110 dBA for four hours per day and for eight hours per day respectively. Control group was exposed to sound less than 85 dBA. Viable cell count was performed using trypan blue. Catalase activity of each group was estimated using ELISA kit.Viable cell count of Group A and Group B was almost same but significantly less than that of control group. Catalase activity of lymphocytes in Group B was significantly low as compared to Group A and controls (p=0.003,p< 0.05. There was no significant difference between catalase activity of Group A and control group.Exposure of sound with frequency 1 KHz and intensity 110 dBA for 4 hours and eight hours per day may induce oxidative stress in growing lymphocytes causing the difference in viable cell count. However the catalase activity depends on duration of exposure. In case of noise exposure of 8 hours per day, it declines significantly as compared to noise exposure of 4 hours per day.

  14. Acute prenatal exposure to ethanol on gestational day 12 elicits opposing deficits in social behaviors and anxiety-like behaviors in Sprague Dawley rats.

    Science.gov (United States)

    Diaz, Marvin R; Mooney, Sandra M; Varlinskaya, Elena I

    2016-09-01

    Our previous research has shown that in Long Evans rats acute prenatal exposure to a high dose of ethanol on gestational day (G) 12 produces social deficits in male offspring and elicits substantial decreases in social preference relative to controls, in late adolescents and adults regardless of sex. In order to generalize the observed detrimental effects of ethanol exposure on G12, pregnant female Sprague Dawley rats were exposed to ethanol or saline and their offspring were assessed in a modified social interaction (SI) test as early adolescents, late adolescents, or young adults. Anxiety-like behavior was also assessed in adults using the elevated plus maze (EPM) or the light/dark box (LDB) test. Age- and sex-dependent social alterations were evident in ethanol-exposed animals. Ethanol-exposed males showed deficits in social investigation at all ages and age-dependent alterations in social preference. Play fighting was not affected in males. In contrast, ethanol-exposed early adolescent females showed no changes in social interactions, whereas older females demonstrated social deficits and social indifference. In adulthood, anxiety-like behavior was decreased in males and females prenatally exposed to ethanol in the EPM, but not the LDB. These findings suggest that social alterations associated with acute exposure to ethanol on G12 are not strain-specific, although they are more pronounced in Long Evans males and Sprague Dawley females. Furthermore, given that anxiety-like behaviors were attenuated in a test-specific manner, this study indicates that early ethanol exposure can have differential effects on different forms of anxiety. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Effects of exposure to 50 Hz, 1 Gauss magnetic field on reproductive traits in male albino rats

    Directory of Open Access Journals (Sweden)

    Islam M. Saadeldin

    2011-01-01

    Full Text Available The effects of extremely low frequency magnetic field ELF-MF (50 Hz/1 Gauss on male fertility were studied in rats. Twenty eight adult male Wistar rats were divided into 4 groups, 2 experimental groups exposed to magnetic field for 21 days and 2 control groups (sham exposed. The first exposed group was sacrificed at the end of the exposure period, and the second exposed group was kept for extra 48 days post exposure to assess the delayed effects of exposure. Significant decrease in the testes weights, sperm motility, sperm count, normal sperms and live sperms was detected in the exposed groups compared to control. Serum testosterone concentrations were significantly increased after 21 days of exposure, and then these changes were corrected after 48 days post exposure. Superoxide dismutase, catalase activities and α-tocopherol concentration were significantly decreased after 21 days of exposure, while the later became non-significant after 48 days post exposure. L-ascorbate concentration was significantly increased after 21 days of exposure, and returned to normal 48 days post exposure. Histopathological examination of the testis from the exposed rats showed a disruption in its architecture with an increase in Leydig cell number and activity, whereas 48 days post exposure, the testicular germ cell layers increased with presence of high apoptotic rates. In conclusion, prolonged exposure to 50 Hz, 1 Gauss MF is biologically toxic to the testicular functions with oxidative stress on spermatogenesis that subsequently may affect male fertility and his sexual efficiency.

  16. Ocular injury by transient formaldehyde exposure in a rabbit eye model.

    Directory of Open Access Journals (Sweden)

    Li-Ju Lai

    Full Text Available Formaldehyde (FA is frequently used in sterilizing surgical instruments and materials. Exposure to FA is highly concerned for eye tissues. Rabbit corneal epithelial cells were examined for changes after FA exposure. Our results showed that cell survival decreased 7 days after transient 3 min exposure to more than 100 ppm FA by trypan blue staining while MTT assay detected significant decrease at 20 ppm at 24 hours observation. The decrease of cell survival rate was concentration (up to 600 ppm- and observation time (1-7 day- dependent. The cell number decreased after 100 ppm FA exposure for more than 10 min at 7-day observation. The FA treated cells showed increased apoptosis/necrosis and cell cycle accumulation at sub G1 phase as well as mitochondria clustering around nucleus. The in vivo rabbit eye exposure for tear production by Schirmer's test revealed that the FA-induced overproduction of tear also exhibited observation time (1-10 day- and FA concentration (20-300 ppm for 5 min exposure-dependent. Activated extracellular signal-regulated kinase (pERK2 in cornea explants by western blotting was reduced and increased c-Jun amino - terminal kinase (JNK activation (pJNK in cornea and conjunctiva was evident at 2 month after exposure to 50-200 ppm FA for 5 min. In conclusion, injury to the eye with transient exposure of up to 100 ppm FA for 3 min decreased corneal cell survival while a more sensitive MTT test detected the cell decrease at 20 ppm FA exposure. Morphology changes can be observed even at 5 ppm FA exposure for 3 min at 7 days after. The FA exposure also increased apoptotic/necrotic cells and sub-G1 phase in cell cycle. Long term effect (2 months after exposure on the eye tissues even after the removal of FA can be observed with persistent JNK activation in cornea and conjunctiva.

  17. Dental caries area of rat molar expanded by cigarette smoke exposure.

    Science.gov (United States)

    Fujinami, Y; Nakano, K; Ueda, O; Ara, T; Hattori, T; Kawakami, T; Wang, P-L

    2011-01-01

    Passive smoking is the involuntary inhalation of cigarette smoke (CS) and has an adverse impact on oral health. We examined the effect of CS exposure on caries risk and experimental dental caries. Experimental dental caries was induced in rat maxillary molars which were inoculated orally with Streptococcus mutans MT8148 and maintained on a cariogenic diet (diet 2000) and high sucrose water during the experimental period. CS-exposed rats were intermittently housed in an animal chamber with whole-body exposure to CS until killed. Whole saliva was collected before CS exposure (day 0) and for 30 days after the start of CS exposure. Saliva secretion was stimulated by administration of isoproterenol and pilocarpine after anesthesia. Maxillary molars were harvested on day 31. The increase in body weight of the CS-exposed rats was less than that of the control rats. Salivary flow rate, concentration of S. mutans in the stimulated saliva and caries activity score did not significantly differ between 0 and 30 days after the start of CS exposure. Histological examination of the caries-affected area on maxillary molars 30 days after CS exposure showed expansion compared to control rats. In the electron probe microanalysis, no differences were observed between the mineral components of the CS-exposed teeth and the control teeth. These results suggest that CS exposure expands the caries-affected area in the maxillary molars of the rat. Copyright © 2011 S. Karger AG, Basel.

  18. Years of life lost due to external radiation exposure

    Directory of Open Access Journals (Sweden)

    Raičević Jagoš J.

    2004-01-01

    Full Text Available In this paper a new approach for calculation of the years of life lost per excess death due to stochastic health effects is applied to external exposure pathways. The short-term external exposures are due to the passage of radioactive cloud and due to the skin and clothes contamination. The long-term external exposure is the one from the radioactive material deposited on the ground (groundshine. Three nuclides, 131I, 137Cs, and 239Pu, and with the extremely wide range of half-life are considered in order to examine their possible influence on the calculated values of years of life lost. For each of these nuclides, the number of years of life lost has been found as a decreasing function of the age at the expo sure and presented graphically in this paper. For protracted exposures, the fully averaged number of years of life lost is negative correlated with the nuclide’s half-life. On the other hand, the short-term external exposures do not depend on the nuclide’s half-life. In addition, a weak years of life lost dependence of the dose has been commented.

  19. Web aesthetics effects on user decisions: impact of exposure length on website quality perceptions and buying intentions

    NARCIS (Netherlands)

    Lorenzo-Romero, C.; Constantinides, Efthymios; Alarcon-del-Amo, M.d.C.

    2013-01-01

    This study examines the impact of three types of aesthetics (classical, expressive, and design aesthetics) on users' quality perceptions about websites based on very short exposure (one second) to websites. It also examines the consistency of website quality perceptions based on very short exposure

  20. Formaldehyde and co-exposure with benzene induce compensation of bone marrow and hematopoietic stem/progenitor cells in BALB/c mice during post-exposure period

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Chenxi [Key Laboratory of Ecological Safety Monitoring and Evaluation, School of Life Sciences, Hunan Normal University, Changsha 410081, Hunan (China); Section of Environmental Biomedicine, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, Hubei (China); Chen, Mouying [Key Laboratory of Ecological Safety Monitoring and Evaluation, School of Life Sciences, Hunan Normal University, Changsha 410081, Hunan (China); You, Huihui [Section of Environmental Biomedicine, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, Hubei (China); Qiu, Feng [Key Laboratory of Ecological Safety Monitoring and Evaluation, School of Life Sciences, Hunan Normal University, Changsha 410081, Hunan (China); Wen, Huaxiao; Yuan, Junlin [Section of Environmental Biomedicine, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, Hubei (China); Xiang, Shuanglin, E-mail: xshlin@hunnu.edu.cn [Key Laboratory of Ecological Safety Monitoring and Evaluation, School of Life Sciences, Hunan Normal University, Changsha 410081, Hunan (China); Yang, Xu, E-mail: yangxu@mail.ccnu.edu.cn [Section of Environmental Biomedicine, Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, Hubei (China)

    2017-06-01

    Formaldehyde (FA) is a human leukemogen. Since there is a latency period between initial FA exposure and the development of leukemia, the subsequent impact of FA on hematopoietic stem or progenitor cells (HSCs/HPCs) in post-exposure stage is crucial for a deep understanding of FA-induced hematotoxicity. BALB/c mice were exposed to 3 mg/m{sup 3} FA for 2 weeks, mimicking occupational exposure, and were monitored for another 7 days post-exposure. Meanwhile, we included benzene (BZ) as a positive control, separately and together with FA because co-exposure occurs frequently. After 7-day recovery, colonies of progenitors for CFU-GM and BFU-E, and nucleated bone marrow cells in FA-exposed mice were comparable to controls, although they were significantly reduced during exposure. Levels of reactive oxygen species (ROS) and 8-hydroxy-2′-deoxyguanosine (8-OHdG) in CFU-GM and BFU-E from FA-exposed mice were higher than controls, although the increase in 8-OHdG was not significant. Granulocyte-macrophage colony stimulating factor (GM-CSF) level in the FA group was lower than controls, but the expression level for the receptor was not upregulated. It suggests that HSCs/HPCs in FA-exposed mice respond to a small amount of GM-CSF and proliferate rapidly, which may cause a possible risk of expansion of abnormal stem/progenitor cell clones. FA co-exposure with BZ was more potent for promoting CFU-GM formation and inducing ROS in BFU-E and 8-OHdG in CFU-GM during the post-exposure period. The compensation of myeloid progenitors with elevated ROS and 8-OHdG may lead to a risk of transforming normal HSCs/HPCs to leukemic stem/progenitor cells. Thus, co-exposure may pose a greater leukemia risk. - Highlights: • Nucleated bone marrow cell count recovered after 7 days post-FA and/or BZ exposure. • CFU-GM showed an increase in colonies and 8-OHdG after 7 days post-FA + BZ exposure. • Levels of ROS in CFU-GM and BFU-E were increased by FA or FA + BZ during recovery. • Levels of

  1. Formaldehyde and co-exposure with benzene induce compensation of bone marrow and hematopoietic stem/progenitor cells in BALB/c mice during post-exposure period

    International Nuclear Information System (INIS)

    Wei, Chenxi; Chen, Mouying; You, Huihui; Qiu, Feng; Wen, Huaxiao; Yuan, Junlin; Xiang, Shuanglin; Yang, Xu

    2017-01-01

    Formaldehyde (FA) is a human leukemogen. Since there is a latency period between initial FA exposure and the development of leukemia, the subsequent impact of FA on hematopoietic stem or progenitor cells (HSCs/HPCs) in post-exposure stage is crucial for a deep understanding of FA-induced hematotoxicity. BALB/c mice were exposed to 3 mg/m 3 FA for 2 weeks, mimicking occupational exposure, and were monitored for another 7 days post-exposure. Meanwhile, we included benzene (BZ) as a positive control, separately and together with FA because co-exposure occurs frequently. After 7-day recovery, colonies of progenitors for CFU-GM and BFU-E, and nucleated bone marrow cells in FA-exposed mice were comparable to controls, although they were significantly reduced during exposure. Levels of reactive oxygen species (ROS) and 8-hydroxy-2′-deoxyguanosine (8-OHdG) in CFU-GM and BFU-E from FA-exposed mice were higher than controls, although the increase in 8-OHdG was not significant. Granulocyte-macrophage colony stimulating factor (GM-CSF) level in the FA group was lower than controls, but the expression level for the receptor was not upregulated. It suggests that HSCs/HPCs in FA-exposed mice respond to a small amount of GM-CSF and proliferate rapidly, which may cause a possible risk of expansion of abnormal stem/progenitor cell clones. FA co-exposure with BZ was more potent for promoting CFU-GM formation and inducing ROS in BFU-E and 8-OHdG in CFU-GM during the post-exposure period. The compensation of myeloid progenitors with elevated ROS and 8-OHdG may lead to a risk of transforming normal HSCs/HPCs to leukemic stem/progenitor cells. Thus, co-exposure may pose a greater leukemia risk. - Highlights: • Nucleated bone marrow cell count recovered after 7 days post-FA and/or BZ exposure. • CFU-GM showed an increase in colonies and 8-OHdG after 7 days post-FA + BZ exposure. • Levels of ROS in CFU-GM and BFU-E were increased by FA or FA + BZ during recovery. • Levels of GM

  2. Neighbourhood Characteristics and Long-Term Air Pollution Levels Modify the Association between the Short-Term Nitrogen Dioxide Concentrations and All-Cause Mortality in Paris.

    Science.gov (United States)

    Deguen, Séverine; Petit, Claire; Delbarre, Angélique; Kihal, Wahida; Padilla, Cindy; Benmarhnia, Tarik; Lapostolle, Annabelle; Chauvin, Pierre; Zmirou-Navier, Denis

    2015-01-01

    While a great number of papers have been published on the short-term effects of air pollution on mortality, few have tried to assess whether this association varies according to the neighbourhood socioeconomic level and long-term ambient air concentrations measured at the place of residence. We explored the effect modification of 1) socioeconomic status, 2) long-term NO2 ambient air concentrations, and 3) both combined, on the association between short-term exposure to NO2 and all-cause mortality in Paris (France). A time-stratified case-crossover analysis was performed to evaluate the effect of short-term NO2 variations on mortality, based on 79,107 deaths having occurred among subjects aged over 35 years, from 2004 to 2009, in the city of Paris. Simple and double interactions were statistically tested in order to analyse effect modification by neighbourhood characteristics on the association between mortality and short-term NO2 exposure. The data was estimated at the census block scale (n=866). The mean of the NO2 concentrations during the five days prior to deaths were associated with an increased risk of all-cause mortality: overall Excess Risk (ER) was 0.94% (95%CI=[0.08;1.80]. A higher risk was revealed for subjects living in the most deprived census blocks in comparison with higher socioeconomic level areas (ER=3.14% (95%CI=[1.41-4.90], ppollution episodes. There is also an indication that people living in these disadvantaged census blocks might experience even higher risk following short-term air pollution episodes, when they are also chronically exposed to higher NO2 levels.

  3. Short-term exposure to warm microhabitats could explain amphibian persistence with Batrachochytrium dendrobatidis.

    Science.gov (United States)

    Daskin, Joshua H; Alford, Ross A; Puschendorf, Robert

    2011-01-01

    Environmental conditions can alter the outcomes of symbiotic interactions. Many amphibian species have declined due to chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd), but many others persist despite high Bd infection prevalence. This indicates that Bd's virulence is lower, or it may even be a commensal, in some hosts. In the Australian Wet Tropics, chytridiomycosis extirpated Litoria nannotis from high-elevation rain forests in the early 1990 s. Although the species is recolonizing many sites, no population has fully recovered. Litoria lorica disappeared from all known sites in the early 1990 s and was thought globally extinct, but a new population was discovered in 2008, in an upland dry forest habitat it shares with L. nannotis. All frogs of both species observed during three population censuses were apparently healthy, but most carried Bd. Frogs perch on sun-warmed rocks in dry forest streams, possibly keeping Bd infections below the lethal threshold attained in cooler rain forests. We tested whether short-term elevated temperatures can hamper Bd growth in vitro over one generation (four days). Simulating the temperatures available to frogs on strongly and moderately warmed rocks in dry forests, by incubating cultures at 33°C for one hour daily, reduced Bd growth below that of Bd held at 15°C constantly (representing rain forest habitats). Even small decreases in the exponential growth rate of Bd on hosts may contribute to the survival of frogs in dry forests.

  4. Short-term exposure to warm microhabitats could explain amphibian persistence with Batrachochytrium dendrobatidis.

    Directory of Open Access Journals (Sweden)

    Joshua H Daskin

    Full Text Available Environmental conditions can alter the outcomes of symbiotic interactions. Many amphibian species have declined due to chytridiomycosis, caused by the pathogenic fungus Batrachochytrium dendrobatidis (Bd, but many others persist despite high Bd infection prevalence. This indicates that Bd's virulence is lower, or it may even be a commensal, in some hosts. In the Australian Wet Tropics, chytridiomycosis extirpated Litoria nannotis from high-elevation rain forests in the early 1990 s. Although the species is recolonizing many sites, no population has fully recovered. Litoria lorica disappeared from all known sites in the early 1990 s and was thought globally extinct, but a new population was discovered in 2008, in an upland dry forest habitat it shares with L. nannotis. All frogs of both species observed during three population censuses were apparently healthy, but most carried Bd. Frogs perch on sun-warmed rocks in dry forest streams, possibly keeping Bd infections below the lethal threshold attained in cooler rain forests. We tested whether short-term elevated temperatures can hamper Bd growth in vitro over one generation (four days. Simulating the temperatures available to frogs on strongly and moderately warmed rocks in dry forests, by incubating cultures at 33°C for one hour daily, reduced Bd growth below that of Bd held at 15°C constantly (representing rain forest habitats. Even small decreases in the exponential growth rate of Bd on hosts may contribute to the survival of frogs in dry forests.

  5. Impact of Fluoroquinolone Exposure Prior to Tuberculosis Diagnosis on Clinical Outcomes in Immunocompromised Patients.

    Science.gov (United States)

    Lee, Ju Young; Lee, Hyun Jung; Kim, Yong Kyun; Yu, Shinae; Jung, Jiwon; Chong, Yong Pil; Lee, Sang-Oh; Choi, Sang-Ho; Shim, Tae Sun; Kim, Yang Soo; Woo, Jun Hee; Kim, Sung-Han

    2016-07-01

    There have been concerns about an association of fluoroquinolone (FQ) use prior to tuberculosis (TB) diagnosis with adverse outcomes. However, FQ use might prevent clinical deterioration in missed TB patients, especially in those who are immunocompromised, until they receive definitive anti-TB treatment. All adult immunocompromised patients with smear-negative and culture-positive TB at a tertiary care hospital in Korea over a 2-year period were included in this study. Long-term FQ (≥7 days) use was defined as exposure to FQ for at least 7 days prior to TB diagnosis. A total of 194 patients were identified: 33 (17%) in the long-term FQ group and 161 (83%) in the comparator, including a short-term FQ group (n = 23), non-FQ group (n = 78), and a group receiving no antibiotics (n = 60). Patients in the long-term FQ group presented with atypical chest radiologic pattern more frequently than those in the comparator (77% [24/31] versus 46% [63/138]; P = 0.001). The median time from mycobacterial test to positive mycobacterial culture appeared to be longer in the long-term FQ group (8.1 weeks versus 7.7 weeks; P = 0.09), although the difference was not statistically significant. Patients in the long-term FQ group were less likely to receive empirical anti-TB treatment (55% versus 74%; P = 0.03). The median time from mycobacterial test to anti-TB therapy was longer in the long-term FQ group (4.6 weeks versus 2.2 weeks; P 0.99) or in the 30-day (6% versus 6%; P > 0.99) or 90-day (12% versus 12%; P > 0.99) mortality rate between the two groups. FQ exposure (≥7 days) prior to TB diagnosis in immunocompromised patients appears not to be associated with adverse outcomes. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  6. Consequences of early postnatal benzodiazepines exposure in rats. I. Cognitive-like behavior

    Directory of Open Access Journals (Sweden)

    Anna eMikulecka

    2014-03-01

    Full Text Available Clinical and experimental studies suggest possible risks associated with the repeated administration of BZDS during the prenatal or early postnatal period on further development and behavior. In the present study, we assess short- and long-term effects of early exposure to clonazepam (CZP on cognitive tasks. CZP (0.5 or 1.0 mg/kg/day was administered from postnatal day (P7 until P11, and animals were exposed to the following behavioral tests at different developmental stages: (1 a homing response test, which exploits the motivation of a rat pup to reach its home nest, was administered on P12, P15, P18 and P23 rats; (2 passive avoidance was tested in three trials (at 0 h, 2 h and 24 h intervals on P12, P15, P18, P25 and P32 rats; (3 within- and between-session habituation was tested in an open field (OF at P70; and (4 a long-term memory version of the Morris water maze (MWM was tested at P80. A 1.0 mg/kg dose of CZP extended latency in the homing response and decreased the number of correct responses when tested at P12 and P23. In the first trial of the passive avoidance test, latency to enter a dark compartment was shorter in the CZP-exposed rats. Both treated and control animals older than P15 learned the passive-avoidance response at the same rate. Irrespective of the treatments, all adult animals showed within-session habituation. Between-session habituation, however, was found only in the controls. With respect to the MWM test, all animals learned to reach the platform, but animals exposed to higher doses of CZP spent more time swimming in the first acquisition test. No difference between groups was found in a repeated acquisition test (10 and 40 days after the first acquisition test. The results of the present study show that even short-term exposure to CZP alters behavioral responsiveness in pre-weaning, juvenile and adult animals. Not only were changes observed on conventional cognitive tests in our study, but the changes also seem to be

  7. Physicochemical changes of 'Phulae' pineapple fruit treated with short-term anoxia during ambient storage.

    Science.gov (United States)

    Techavuthiporn, Chairat; Boonyaritthongchai, Panida; Supabvanich, Suriyan

    2017-08-01

    The effects of short-term anoxia exposure for 16h on physicochemical changes of 'Phulae' pineapple fruit stored at ambient temperature (25±2°C) were investigated. The respiratory rate of the fruit was induced by the anoxia treatment. However, it retarded the increase in moisture loss and maintained both flesh and pulp colour by inhibiting polyphenol oxidase (PPO) activity of the both tissues. The anoxia exposure delayed the increase in total sugar content and enhanced total ascorbic acid content during storage. The half-cut pineapple fruit showed that the anoxia exposure completely inhibited internal transparency of the flesh tissue adjacent to core during the storage. In conclusion, the short-term anoxia exposure for 16h maintained postharvest quality, retarded physiological disorder and enhanced nutritional values of the pineapple fruit stored at ambient temperature (25±2°C). Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Estimating Contact Exposure in Football Using the Head Impact Exposure Estimate.

    Science.gov (United States)

    Kerr, Zachary Y; Littleton, Ashley C; Cox, Leah M; DeFreese, J D; Varangis, Eleanna; Lynall, Robert C; Schmidt, Julianne D; Marshall, Stephen W; Guskiewicz, Kevin M

    2015-07-15

    Over the past decade, there has been significant debate regarding the effect of cumulative subconcussive head impacts on short and long-term neurological impairment. This debate remains unresolved, because valid epidemiological estimates of athletes' total contact exposure are lacking. We present a measure to estimate the total hours of contact exposure in football over the majority of an athlete's lifespan. Through a structured oral interview, former football players provided information related to primary position played and participation in games and practice contacts during the pre-season, regular season, and post-season of each year of their high school, college, and professional football careers. Spring football for college was also included. We calculated contact exposure estimates for 64 former football players (n = 32 college football only, n = 32 professional and college football). The head impact exposure estimate (HIEE) discriminated between individuals who stopped after college football, and individuals who played professional football (p < 0.001). The HIEE measure was independent of concussion history (p = 0.82). Estimating total hours of contact exposure may allow for the detection of differences between individuals with variation in subconcussive impacts, regardless of concussion history. This measure is valuable for the surveillance of subconcussive impacts and their associated potential negative effects.

  9. Significant long-term, but not short-term, hippocampal-dependent memory impairment in adult rats exposed to alcohol in early postnatal life.

    Science.gov (United States)

    Goodfellow, Molly J; Lindquist, Derick H

    2014-09-01

    In rodents, ethanol exposure in early postnatal life is known to induce structural and functional impairments throughout the brain, including the hippocampus. Herein, rat pups were administered one of three ethanol doses over postnatal days (PD) 4-9, a period of brain development comparable to the third trimester of human pregnancy. As adults, control and ethanol rats were trained and tested in a variant of hippocampal-dependent one-trial context fear conditioning. In Experiment 1, subjects were placed into a novel context and presented with an immediate footshock (i.e., within ∼8 sec). When re-exposed to the same context 24 hr later low levels of conditioned freezing were observed. Context pre-exposure 24 hr prior to the immediate shock reversed the deficit in sham-intubated and unintubated control rats, enhancing freezing behavior during the context retention test. Even with context pre-exposure, however, significant dose-dependent reductions in contextual freezing were seen in ethanol rats. In Experiment 2, the interval between context pre-exposure and the immediate shock was shortened to 2 hr, in addition to the standard 24 hr. Ethanol rats trained with the 2 hr, but not 24 hr, interval displayed retention test freezing levels roughly equal to controls. Results suggest the ethanol rats can encode a short-term context memory and associate it with the aversive footshock 2 hr later. In the 24 hr ethanol rats the short-term context memory is poorly transferred or consolidated into long-term memory, we propose, impeding the memory's subsequent retrieval and association with shock. © 2014 Wiley Periodicals, Inc.

  10. Assessment of indoor environment in Paris child day care centers.

    Science.gov (United States)

    Roda, Célina; Barral, Sophie; Ravelomanantsoa, Hanitriniala; Dusséaux, Murielle; Tribout, Martin; Le Moullec, Yvon; Momas, Isabelle

    2011-11-01

    Children are sensitive to indoor environmental pollution. Up until now there has been a lack of data on air quality in child day care centers. The aim of this study is to document the indoor environment quality of Paris child day care centers by repeated measurements, and to compare pollutant levels in child day care centers with levels in Paris dwellings. We selected 28 child day care centers frequented by a random sample of babies who participated in the PARIS birth cohort environmental investigation, and visited the child day care centers for one week twice in one year. Biological contaminants assessed were fungi, endotoxin, dust mite allergens, and chemical pollutants: aldehydes, volatile organic compounds and nitrogen dioxide (NO2). Relative humidity, temperature, and carbon dioxide levels were measured simultaneously. A standardized questionnaire was used to gather information about the buildings and their inhabitants. Airborne endotoxin levels in child day care centers were higher than those found in Paris dwellings. Dust mite allergens in child day care centers were below the threshold level for sensitization in the majority of samples, and in common with dwelling samples. Penicillium and Cladosporium were the most commonly identified genera fungi. The child day care center indoor/outdoor ratio for most chemical pollutants was above unity except for NO2, the levels for NO2 being significantly higher than those measured in homes. Chemical and biological contamination in child day care centers appears to be low, apart from endotoxin and NO2. Failure to take child exposure in child day care centers into account could result in an overestimation of children's exposure to other pollutants. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Expression of transcription factors after short-term exposure of Arabidopsis thaliana cell cultures to hyper-g, and to simulated and sounding rocket micro-g

    Science.gov (United States)

    Hampp, R.; Babbick, M.

    Previous microarray studies with cell cultures of Arabidopsis thaliana cv Columbia have shown responses in gene expression which were partly specific to exposure to microgravity sounding rocket experiment TEXUS In order to get access to early responses upon changes in gravitational fields we used exposure times as short as 2 min For this purpose we selected a range of genes which code for different groups of transcription factors WRKY ERF MYB MADS Samples were taken in 5-min clinorotation 2- and 3-dimensional hypergravity 8g and 2-min intervals sounding rocket experiment Amounts of transcripts were determined by quantitative RT PCR Most transcripts showed a significant transient change in content within a time frame of up to 30 min after changing the external gravitational field strength They could be grouped into 1 basic stress responses which occurred under all conditions 2 clinorotation-related effects which were either identical or opposite between 2D 60 rpm 4x10 -2 g and 3D clinorotation random positioning machine and 3 alterations specific to the microgravity exposure under sounding rocket conditions MAXUS The data are discussed in relation to gravitation-dependent signalling chains and with regard to the simulation of microgravity by means of clinorotation Supported by a grant from the Deutsches Zentrum f u r Luft- und Raumfahrt e V grant no 50 WB 0143

  12. Short-chain chlorinated paraffins (SCCPs) induced thyroid disruption by enhancement of hepatic thyroid hormone influx and degradation in male Sprague Dawley rats.

    Science.gov (United States)

    Gong, Yufeng; Zhang, Haijun; Geng, Ningbo; Xing, Liguo; Fan, Jingfeng; Luo, Yun; Song, Xiaoyao; Ren, Xiaoqian; Wang, Feidi; Chen, Jiping

    2018-06-01

    Short-chain chlorinated paraffins (SCCPs) are known to disturb thyroid hormone (TH) homeostasis in rodents. However, the mechanism remains to be fully characterized. In this study, male Sprague Dawley rats received SCCPs (0, 1, 10, or 100mg/kg/day) via gavage once a day for consecutive 28days. Plasma and hepatic TH concentrations, thyrocyte structure, as well as thyroid and hepatic mRNA and protein levels of genes associated with TH homeostasis were examined. Moreover, we performed molecular docking to predict interactions between constitutive androstane receptor (CAR), a key regulator in xenobiotic-induced TH metabolism, with different SCCP molecules. Exposure to SCCPs significantly decreased the circulating free thyroxine (T 4 ) and triiodothyronine (T 3 ) levels, but increased thyroid-stimulating hormone (TSH) levels by a feedback mechanism. Decreased hepatic T 4 and increased hepatic T 3 levels were also seen after 100mg/kg/day SCCPs exposure. SCCPs didn't show any significant effects on the expression of thyroid TH synthesis genes or thyrocyte structure. However, stimulation effects were observed for mRNA and protein levels of hepatic uridine diphosphoglucuronosyl transferase (UGT) 1A1 and organic anion transporter 2, suggesting an accelerated TH metabolism in rat liver. The increased cytochrome P450 2B1 but not 1A1 mRNA and protein levels indicated that the CAR signaling was activated by SCCPs exposure. According to docking analysis, SCCPs form hydrophobic interactions with CAR and the binding affinity shows dependency on chlorine content. Overall, our data showed that CAR implicated enhancement of hepatic TH influx and degradation could be the main cause for SCCPs induced TH deficiency in male rats. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Dietary exposure to short- and medium-chain chlorinated paraffins in meat and meat products from 20 provinces of China.

    Science.gov (United States)

    Huang, Huiting; Gao, Lirong; Zheng, Minghui; Li, Jingguang; Zhang, Lei; Wu, Yongning; Wang, Runhua; Xia, Dan; Qiao, Lin; Cui, Lili; Su, Guijin; Liu, Wenbin; Liu, Guorui

    2018-02-01

    Food intake is one of the main pathways of human exposure to chlorinated paraffins (CPs). This study assessed the dietary exposure for the general Chinese population to short-chain chlorinated paraffin (SCCPs) and medium-chain chlorinated paraffins (MCCPs) through meat and meat products. Twenty samples of meat and meat products from 20 Chinese provinces were collected in 2011. As the sampling sites covered about two-thirds of the Chinese population, the meat samples were considered to be representative of the true characteristics of CPs contamination in Chinese meat products. The concentrations of SCCPs and MCCPs in the meat samples were measured using the comprehensive two-dimensional gas chromatography electron capture negative ionization high-resolution time-of-flight mass spectrometry method. Forty-eight SCCP and MCCP homolog groups were detected in the meat samples. The mean SCCP and MCCP concentrations in all meat samples were 129 ± 4.1 ng g -1 wet weight and 5.7 ± 0.59 ng g -1 wet weight, respectively. The concentrations of SCCPs and MCCPs varied in samples from different provinces. The geographical distribution of CP concentrations was similar to the distribution of CPs manufacturing plants in China. The most abundant groups of SCCPs in all samples were C 10-11 Cl 6-7 , and the most abundant groups of MCCPs in most samples were C 14 Cl 7-8 . The possible sources of SCCPs and MCCPs in meat and meat products might be CP-42 and CP-52. The 50th percentile estimated daily intakes of SCCPs and MCCPs through meat consumption for a "standard" Chinese adult male were 0.13 and 0.0047 μg kg -1 bw d -1 , respectively, both much lower than the tolerable daily intakes (TDIs) for SCCPs and MCCPs. This preliminary risk assessment has indicated that the indirect exposure of SCCPs and MCCPs through meat consumption does not pose significant risk to human health in China. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Alterations of tissue metallothionein and vitellogenin concentrations in tropical cup oysters (Saccostrea sp.) following short-term (96 h) exposure to cadmium

    International Nuclear Information System (INIS)

    Moncaleano-Niño, Angela M.; Barrios-Latorre, Sergio A.; Poloche-Hernández, Javier F.; Becquet, Vanessa; Huet, Valérie; Villamil, Luisa; Thomas-Guyon, Hélène; Ahrens, Michael J.; Luna-Acosta, Andrea

    2017-01-01

    Highlights: • The cup oyster Saccostrea sp. is present in Santa Marta, Colombian Caribbean. • 96 h exposure of oysters to Cd increased metallothionein concentrations in digestive glands up to 2-fold. • 96 h exposure of oysters to Cd decreased vitellogenin concentrations in gonads up to 6-fold. • Metallothionein and vitellogenin tissue concentrations correlated with whole tissue Cd concentrations. • Significant changes in metallothionein and vitellogenin levels were only evident at Cd concentrations above 100 μg/L. - Abstract: Metallothioneins and vitellogenins are low molecular weight proteins that have been used widely in environmental monitoring as biomarkers of exposure and damage to metals and estrogenic compounds, respectively. In the present study, the responses of metallothionein and vitellogenin tissue concentrations were measured following acute (96 h) aqueous exposures to cadmium in Saccostrea sp., a tropical cup oyster native to the Western Pacific Ocean that has recently established itself in the Caribbean Sea. Adult oysters (1.5–5.0 cm shell length) collected from the municipal marina of Santa Marta, Colombia (Caribbean Sea) and acclimated for 5 days in the laboratory, were exposed to Cd at five concentrations (0, 1, 10, 100 and 1000 μg/L) and their tissues (gills, digestive gland and adductor muscle) were analyzed in pools of 5 individuals (3 replicates per concentration). Metallothioneins in digestive glands of oysters exposed to Cd concentrations ≥ 100 μg/L showed a significant increase, from 8.0 to 14.8 μg MT/mg total protein, whereas metallothionein concentrations in gills increased to lesser extent, and no differences were observed in adductor muscle. Metallothionein concentrations in digestive gland and gills correlated directly with whole soft tissue Cd concentrations (ranging from 2 to 297 μg/g dw Cd). Vitellogenin in homogenates of oyster gonad tissue, after 96 h of exposure to 1000 μg/L Cd, were significantly lower (0

  15. Alterations of tissue metallothionein and vitellogenin concentrations in tropical cup oysters (Saccostrea sp.) following short-term (96 h) exposure to cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Moncaleano-Niño, Angela M.; Barrios-Latorre, Sergio A.; Poloche-Hernández, Javier F. [Department of Biological Sciences, Universidad de Bogota Jorge Tadeo Lozano, Carrera 4 No. 22-61, Bogota (Colombia); Becquet, Vanessa; Huet, Valérie [Littoral Environnement et Sociétés (LIENSs) – UMR 7266, CNRS-Université de La Rochelle, Bâtiment ILE 2, rue Olympe de Gouges, 17 000 La Rochelle (France); Villamil, Luisa [Department of Biological Sciences, Universidad de Bogota Jorge Tadeo Lozano, Carrera 4 No. 22-61, Bogota (Colombia); Thomas-Guyon, Hélène [Littoral Environnement et Sociétés (LIENSs) – UMR 7266, CNRS-Université de La Rochelle, Bâtiment ILE 2, rue Olympe de Gouges, 17 000 La Rochelle (France); Ahrens, Michael J., E-mail: michael.ahrens@utadeo.edu.co [Department of Biological Sciences, Universidad de Bogota Jorge Tadeo Lozano, Carrera 4 No. 22-61, Bogota (Colombia); Luna-Acosta, Andrea [Department of Biological Sciences, Universidad de Bogota Jorge Tadeo Lozano, Carrera 4 No. 22-61, Bogota (Colombia)

    2017-04-15

    Highlights: • The cup oyster Saccostrea sp. is present in Santa Marta, Colombian Caribbean. • 96 h exposure of oysters to Cd increased metallothionein concentrations in digestive glands up to 2-fold. • 96 h exposure of oysters to Cd decreased vitellogenin concentrations in gonads up to 6-fold. • Metallothionein and vitellogenin tissue concentrations correlated with whole tissue Cd concentrations. • Significant changes in metallothionein and vitellogenin levels were only evident at Cd concentrations above 100 μg/L. - Abstract: Metallothioneins and vitellogenins are low molecular weight proteins that have been used widely in environmental monitoring as biomarkers of exposure and damage to metals and estrogenic compounds, respectively. In the present study, the responses of metallothionein and vitellogenin tissue concentrations were measured following acute (96 h) aqueous exposures to cadmium in Saccostrea sp., a tropical cup oyster native to the Western Pacific Ocean that has recently established itself in the Caribbean Sea. Adult oysters (1.5–5.0 cm shell length) collected from the municipal marina of Santa Marta, Colombia (Caribbean Sea) and acclimated for 5 days in the laboratory, were exposed to Cd at five concentrations (0, 1, 10, 100 and 1000 μg/L) and their tissues (gills, digestive gland and adductor muscle) were analyzed in pools of 5 individuals (3 replicates per concentration). Metallothioneins in digestive glands of oysters exposed to Cd concentrations ≥ 100 μg/L showed a significant increase, from 8.0 to 14.8 μg MT/mg total protein, whereas metallothionein concentrations in gills increased to lesser extent, and no differences were observed in adductor muscle. Metallothionein concentrations in digestive gland and gills correlated directly with whole soft tissue Cd concentrations (ranging from 2 to 297 μg/g dw Cd). Vitellogenin in homogenates of oyster gonad tissue, after 96 h of exposure to 1000 μg/L Cd, were significantly lower (0

  16. Providing support for day-to-day monitoring of shoreline cleanup operations

    International Nuclear Information System (INIS)

    Lamarche, A.; Tarpley, J.

    1997-01-01

    Experiences gained during the 'Cape Mohican' incident in October 1996, in San Francisco Bay, were recounted and proposed as a potential example of day-to-day monitoring, evaluation and reporting of shoreline cleanup effort. During this cleanup a set of communications procedures, progress reports and maps were developed which should be equally useful in other similar situations. The cartographic representations were specially highlighted as they focused on ways to provide a clear picture of the short term modifications in oiling conditions of the affected shoreline. The most important lesson learned from this oil spill was the importance of having personnel and equipment sufficiently matched to the task in order to evaluate oil conditions, produce cleanup recommendations, execute and communicate the status of the cleanup effort as fast, and as efficiently and effectively as possible. It was clearly demonstrated that unless the decision process is streamlined and supported with the best, most up-to-date information, the efforts of the cleanup team would be seriously undermined. 8 refs., 2 tabs., 6 figs

  17. Effect of Short-Term Hypergravity Treatment on Mouse 2-Cell Embryo Development

    Science.gov (United States)

    Ning, Li-Na; Lei, Xiao-Hua; Cao, Yu-Jing; Zhang, Yun-Fang; Cao, Zhong-Hong; Chen, Qi; Duan, En-Kui

    2015-11-01

    Though there are numerous biological experiments, which have been performed in a space environment, to study the physiological effect of space travel on living organisms, while the potential effect of weightlessness or short-term hypergravity on the reproductive system in most species, particularly in mammalian is still controversial and unclear. In our previous study, we investigated the effect of space microgravity on the development of mouse 4-cell embryos by using Chinese SJ-8. .Unexpectedly, we did not get any developed embryo during the space-flight. Considering that the process of space experiment is quite different from most experiments done on earth in several aspects such as, the vibration and short-term hypergravity during the rock launching and landing. Thus we want to know whether the short-term hypergravity produced by the launch process affect the early embryo development in mice, and howthe early embryos respond to the hypergravity. In present study, we are mimicking the short-term hypergravity during launch by using a centrifuge to investigate its influence on the development of early embryo (2-cell) in mice. We also examined the actin filament distribution in 2-cell embryos by immunostaining to test their potential capacity of development under short-term hypergravity exposure. Our results showed that most 2-cell embryos in the hypergravity exposure groups developed into blastocysts with normal morphology after 72h cultured in vitro, and there is no obvious difference in the development rate of blastocyst formation compared to the control. Moreover, there were no statistically significant differences in birth rates after oviduct transfer of 2-cell mouse embryos exposed on short-term hypergravity compared with 1 g condition. In addition, the well-organized actin distribution appeared in 2-cell embryos after exposed on hypergravity and also in the subsequent developmental blastocysts. Taken together, our data shows that short-term exposure in

  18. Using serology to assist with complicated post-exposure prophylaxis for rabies and Australian bat lyssavirus.

    Directory of Open Access Journals (Sweden)

    Niall Conroy

    Full Text Available BACKGROUND: Australia uses a protocol combining human rabies immunoglobulin (HRIG and rabies vaccine for post-exposure prophylaxis (PEP of rabies and Australian bat lyssavirus (ABLV, with the aim of achieving an antibody titre of ≥0.5 IU/ml, as per World Health Organization (WHO guidelines, as soon as possible. METHODOLOGY/PRINCIPAL FINDINGS: We present the course of PEP administration and serological testing for four men with complex requirements. Following dog bites in Thailand, two men (62 years old, 25 years old received no HRIG and had delayed vaccine courses: 23 days between dose two and three, and 18 days between dose one and two, respectively. Both seroconverted following dose four. Another 62-year-old male, who was HIV-positive (normal CD4 count, also suffered a dog bite and had delayed care receiving i.m. rabies vaccine on days six and nine in Thailand. Back in Australia, he received three single and one double dose i.m. vaccines followed by another double dose of vaccine, delivered intradermally and subcutaneously, before seroconverting. A 23-year-old male with a history of allergies received simultaneous HRIG and vaccine following potential ABLV exposure, and developed rash, facial oedema and throat tingling, which was treated with a parenteral antihistamine and tapering dose of steroids. Serology showed he seroconverted following dose four. CONCLUSIONS/SIGNIFICANCE: These cases show that PEP can be complicated by exposures in tourist settings where reliable prophylaxis may not be available, where treatment is delayed or deviates from World Health Organization recommendations. Due to the potentially short incubation time of rabies/ABLV, timely prophylaxis after a potential exposure is needed to ensure a prompt and adequate immune response, particularly in patients who are immune-suppressed or who have not received HRIG. Serology should be used to confirm an adequate response to PEP when treatment is delayed or where a concurrent

  19. Effects of continuous exposure to carbon monoxide on auditory vigilance in man

    Energy Technology Data Exchange (ETDEWEB)

    Davies, D.M.; Jolly, E.J.; Pethybridge, R.J.; Colquhoun, W.P.

    1981-02-01

    Six different groups of non-smoking young male subjcts were stutied separately for 18 consecutive days each in a closed controlled-environment human exposure chamber. Each group was subjected to a 5-day control period in fresh air followed successively by an 8-day period of continuous exposure to 50 ppm, 15 ppm or 0 ppm (controll) by volume of carbon monoxide (CO) in air, and a 5-day recovery period in fresh air. The subjects performed a 1-h auditory vigilance task every day at the same time of day in a fixed qualitative, quantitative, and temporal relationship with food intake, consumption of stimulating beverages, physical activity, and sleep. It was concluded that such CO exposure, involving the continuous carriage of carboxyhaemoglobin loads up to 70%, was without significant effect on auditory vigilance.

  20. Focus on Chronic Exposure for Deriving Drinking Water Guidance Underestimates Potential Risk to Infants

    Directory of Open Access Journals (Sweden)

    Helen Goeden

    2018-03-01

    Full Text Available In 2007, the Minnesota Department of Health (MDH developed new risk assessment methods for deriving human health-based water guidance (HBG that incorporated the assessment of multiple exposure durations and life stages. The methodology is based on US Environmental Protection Agency recommendations for protecting children’s health (US EPA 2002. Over the last 10 years, the MDH has derived multiple duration (e.g., short-term, subchronic, and chronic water guidance for over 60 chemicals. This effort involved derivation of multiple duration reference doses (RfDs and selection of corresponding water intake rates (e.g., infant, child, and lifetime. As expected, RfDs typically decreased with increasing exposure duration. However, the corresponding HBG frequently did not decrease with increasing duration. For more than half of the chemicals, the shorter duration HBG was lower than chronic HBG value. Conventional wisdom has been that chronic-based values will be the most conservative and will therefore be protective of less than chronic exposures. However, the MDH’s experience highlights the importance of evaluating short-term exposures. For many chemicals, elevated intake rates early in life, coupled with short-term RfDs, resulted in the lowest HBG. Drinking water criteria based on chronic assessments may not be protective of short-term exposures in highly exposed populations such as formula-fed infants.