WorldWideScience

Sample records for human exposure acute

  1. Human solvent exposure. Factors influencing the pharmacokinetics and acute toxicity

    DEFF Research Database (Denmark)

    Bælum, Jesper

    1991-01-01

    exposed to mixtures of solvents experience an increased frequency of work related irritative and neurological symptoms although the exposure has been far below the occupational exposure limits. A series of controlled human exposure studies was carried out. Different groups of persons were exposed...... to the most frequent solvent, toluene. Toluene in alveolar air and the urinary excretion of the metabolites were measured and the acute effects of toluene were assessed by the performance in a series of test of the perceptual and psychomotor functions as well as a standardized registration of annoyance...

  2. Human physiological responses to cold exposure: Acute responses and acclimatization to prolonged exposure.

    Science.gov (United States)

    Castellani, John W; Young, Andrew J

    2016-04-01

    Cold exposure in humans causes specific acute and chronic physiological responses. This paper will review both the acute and long-term physiological responses and external factors that impact these physiological responses. Acute physiological responses to cold exposure include cutaneous vasoconstriction and shivering thermogenesis which, respectively, decrease heat loss and increase metabolic heat production. Vasoconstriction is elicited through reflex and local cooling. In combination, vasoconstriction and shivering operate to maintain thermal balance when the body is losing heat. Factors (anthropometry, sex, race, fitness, thermoregulatory fatigue) that influence the acute physiological responses to cold exposure are also reviewed. The physiological responses to chronic cold exposure, also known as cold acclimation/acclimatization, are also presented. Three primary patterns of cold acclimatization have been observed, a) habituation, b) metabolic adjustment, and c) insulative adjustment. Habituation is characterized by physiological adjustments in which the response is attenuated compared to an unacclimatized state. Metabolic acclimatization is characterized by an increased thermogenesis, whereas insulative acclimatization is characterized by enhancing the mechanisms that conserve body heat. The pattern of acclimatization is dependent on changes in skin and core temperature and the exposure duration.

  3. Absence of acute ocular damage in humans after prolonged exposure to intense RF EMF

    Science.gov (United States)

    Adibzadeh, F.; van Rhoon, G. C.; Verduijn, G. M.; Naus-Postema, N. C.; Paulides, M. M.

    2016-01-01

    The eye is considered to be a critical organ when determining safety standards for radio frequency (RF) radiation. Experimental data obtained using animals showed that RF heating of the eye, particularly over a specific threshold, can induce cataracts. During the treatment of cancer in the head and neck by hyperthermia, the eyes receive a considerable dose of RF radiation due to stray radiation from the prolonged (60 min) and intense exposure at 434 MHz of this region. In the current study, we verified the exposure guidelines for humans by determining the association between the electromagnetic and thermal dose in the eyes with the reported ocular effects. We performed a simulation study to retrospectively assess the specific absorption rate (SAR) and temperature increase in the eyes of 16 selected patients (encompassing a total of 74 treatment sessions) whose treatment involved high power delivery as well as a minimal distance between the tumor site and the eye. Our results show that the basic restrictions on the peak 10 g spatial-averaged SAR (10 W kg-1) and peak tissue temperature increase (1 °C) are exceeded by up to 10.4 and 4.6 times, on average, and by at least 6.2 and 1.8 times when considering the lower limit of the 95% confidence interval. Evaluation of the acute effects according to patients’ feedback (all patients), the common toxicity criteria scores (all patients) and an ophthalmology investigation (one patient with the highest exposure) revealed no indication of any serious acute ocular effect, even though the eyes were exposed to high electromagnetic fields, leading to a high thermal dose. We also found that, although there is a strong correlation (R 2  =  0.88) between the predicted induced SAR and temperature in the eye, there are large uncertainties regarding the temperature-SAR relationship. Given this large uncertainty (129%) compared with the uncertainty of 3D temperature simulations (61%), we recommend using temperature

  4. Structural and functional changes of the human macula during acute exposure to high altitude.

    Directory of Open Access Journals (Sweden)

    M Dominik Fischer

    Full Text Available BACKGROUND: This study aimed to quantify structural and functional changes at the macula during acute exposure to high altitude and to assess their structure/function relationship. This work is related to the Tuebingen High Altitude Ophthalmology (THAO study. METHODOLOGY/PRINCIPAL FINDINGS: Spectral domain optical coherence tomography and microperimetry were used to quantify changes of central retinal structure and function in 14 healthy subjects during acute exposure to high altitude (4559 m. High-resolution volume scans and fundus-controlled microperimetry of the posterior pole were performed in addition to best-corrected visual acuity (BCVA measurements and assessment of acute mountain sickness. Analysis of measurements at altitude vs. baseline revealed increased total retinal thickness (TRT in all four outer ETDRS grid subfields during acute altitude exposure (TRT(outer = 2.80 ± 1.00 μm; mean change ± 95%CI. This change was inverted towards the inner four subfields (TRT(inner = -1.89 ± 0.97 μm with significant reduction of TRT in the fovea (TRT(foveal = -6.62 ± 0.90 μm at altitude. BCVA revealed no significant difference compared to baseline (0.06 ± 0.08 logMAR. Microperimetry showed stable mean sensitivity in all but the foveal subfield (MS(foveal = -1.12 ± 0.68 dB. At baseline recordings before and >2 weeks after high altitude exposure, all subjects showed equal levels with no sign of persisting structural or functional sequels. CONCLUSIONS/SIGNIFICANCE: During acute exposure to high altitude central retinal thickness is subject to minor, yet statistically significant changes. These alterations describe a function of eccentricity with an increase in regions with relatively higher retinal nerve fiber content and vascular arcades. However, these changes did not correlate with measures of central retinal function or acute mountain sickness. For the first time a quantitative approach has been used to assess these changes during acute

  5. Structural and Functional Changes of the Human Macula during Acute Exposure to High Altitude

    Science.gov (United States)

    Fischer, M. Dominik; Willmann, Gabriel; Schatz, Andreas; Schommer, Kai; Zhour, Ahmad; Zrenner, Eberhart; Bartz-Schmidt, Karl U.; Gekeler, Florian

    2012-01-01

    Background This study aimed to quantify structural and functional changes at the macula during acute exposure to high altitude and to assess their structure/function relationship. This work is related to the Tuebingen High Altitude Ophthalmology (THAO) study. Methodology/Principal Findings Spectral domain optical coherence tomography and microperimetry were used to quantify changes of central retinal structure and function in 14 healthy subjects during acute exposure to high altitude (4559 m). High-resolution volume scans and fundus-controlled microperimetry of the posterior pole were performed in addition to best-corrected visual acuity (BCVA) measurements and assessment of acute mountain sickness. Analysis of measurements at altitude vs. baseline revealed increased total retinal thickness (TRT) in all four outer ETDRS grid subfields during acute altitude exposure (TRTouter = 2.80±1.00 μm; mean change±95%CI). This change was inverted towards the inner four subfields (TRTinner = −1.89±0.97 μm) with significant reduction of TRT in the fovea (TRTfoveal = −6.62±0.90 μm) at altitude. BCVA revealed no significant difference compared to baseline (0.06±0.08 logMAR). Microperimetry showed stable mean sensitivity in all but the foveal subfield (MSfoveal = −1.12±0.68 dB). At baseline recordings before and >2 weeks after high altitude exposure, all subjects showed equal levels with no sign of persisting structural or functional sequels. Conclusions/Significance During acute exposure to high altitude central retinal thickness is subject to minor, yet statistically significant changes. These alterations describe a function of eccentricity with an increase in regions with relatively higher retinal nerve fiber content and vascular arcades. However, these changes did not correlate with measures of central retinal function or acute mountain sickness. For the first time a quantitative approach has been used to assess these changes during acute, non

  6. Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1981-05-01

    The current knowledge of the carcinogenic effect of radiation in man is considered. The discussion is restricted to dose-incidence data in humans, particularly to certain of those epidemiological studies of human populations that are used most frequently for risk estimation for low-dose radiation carcinogenesis in man. Emphasis is placed solely on those surveys concerned with nuclear explosions and medical exposures. (ACR)

  7. Effects of acute exercise on fear extinction in rats and exposure therapy in humans: Null findings from five experiments.

    Science.gov (United States)

    Jacquart, Jolene; Roquet, Rheall F; Papini, Santiago; Powers, Mark B; Rosenfield, David; Smits, Jasper A J; Monfils, Marie-H

    2017-08-01

    Exposure therapy is an established learning-based intervention for the treatment of anxiety disorders with an average response rate of nearly 50%, leaving room for improvement. Emerging strategies to enhance exposure therapy in humans and fear extinction retention in animal models are primarily pharmacological. These approaches are limited as many patients report preferring non-pharmacological approaches in therapy. With general cognitive enhancement effects, exercise has emerged as a plausible non-pharmacological augmentation strategy. The present study tested the hypothesis that fear extinction and exposure therapy would be enhanced by a pre-training bout of exercise. We conducted four experiments with rats that involved a standardized conditioning and extinction paradigm and a manipulation of exercise. In a fifth experiment, we manipulated vigorous-intensity exercise prior to a standardized virtual reality exposure therapy session among adults with fear of heights. In experiments 1-4, exercise did not facilitate fear extinction, long-term memory, or fear relapse tests. In experiment 5, human participants showed an overall reduction in fear of heights but exercise did not enhance symptom improvement. Although acute exercise prior to fear extinction or exposure therapy, as operationalized in the present 5 studies, did not enhance outcomes, these results must be interpreted within the context of a broader literature that includes positive findings. Taken all together, this suggests that more research is necessary to identify optimal parameters and key individual differences so that exercise can be implemented successfully to treat anxiety disorders. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Acute Meteorite Dust Exposure and Pulmonary Inflammation - Implications for Human Space Exploration

    Science.gov (United States)

    Harrington, A. D.; McCubbin, F. M.; Kaur, J.; Smirnov, A.; Galdanes, K.; Schoonen, M. A. A.; Chen, L. C.; Tsirka, S. E.; Gordon, T.

    2017-01-01

    The previous manned missions to the Moon represent milestones of human ingenuity, perseverance, and intellectual curiosity. However, one of the major ongoing concerns is the array of hazards associated with lunar surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness [1-3]" (Figure 1). It was further reported that the allergic response to the dust worsened with each exposure [4]. The lack of gravity exacerbated the exposure, requiring the astronauts to wear their helmet within the module in order to avoid breathing the irritating particles [1]. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern [5]. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment. Studies on the lunar highland regolith indicate that the dust is not only respirable but also reactive [2, 6-9], and previous studies concluded that it is moderately toxic; generating a greater response than titanium oxide but a lower response than quartz [6]. The presence of reactive oxygen species (ROS) on the surface of the dust has been implicated. However, there is actually little data related to physicochemical characteristics of particulates and pulmonary toxicity, especially as it relates to celestial dust exposure. As a direct response to this deficit, the present study evaluates the role of a particulate's innate geochemical features (e.g., bulk chemistry, internal composition, morphology, size, and reactivity) in generating adverse toxicological responses in vitro and in vivo. This highly interdisciplinary

  9. Pulmonary Inflammatory Responses To Acute Meteorite Dust Exposures - Implications For Human Space Exploration

    Science.gov (United States)

    Harrington, A. D.; McCubbin, F. M.; Kaur, J.; Smirnov, A.; Galdanes, K.; Schoonen, M. A. A.; Chen, L. C.; Tsirka, S. E.; Gordon, T.

    2017-01-01

    The previous manned missions to the Moon represent milestones of human ingenuity, perseverance, and intellectual curiosity. However, one of the major ongoing concerns is the array of hazards associated with lunar surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness" (Figure 1). It was further reported that the allergic response to the dust worsened with each exposure. The lack of gravity exacerbated the exposure, requiring the astronauts to wear their helmet within the module in order to avoid breathing the irritating particles. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment. Studies on the lunar highland regolith indicate that the dust is not only respirable but also reactive, and previous studies concluded that it is moderately toxic; generating a greater response than titanium oxide but a lower response than quartz. The presence of reactive oxygen species (ROS) on the surface of the dust has been implicated. However, there is actually little data related to physicochemical characteristics of particulates and pulmonary toxicity, especially as it relates to celestial dust exposure. As a direct response to this deficit, the present study evaluates the role of a particulate's innate geochemical features (e.g., bulk chemistry, internal composition, morphology, size, and reactivity) in generating adverse toxicological responses in vitro and in vivo. This highly interdisciplinary study evaluates the relative

  10. Pro-inflammatory responses of human bronchial epithelial cells to acute nitrogen dioxide exposure.

    Science.gov (United States)

    Ayyagari, Vijayalakshmi N; Januszkiewicz, Adolph; Nath, Jayasree

    2004-04-15

    Nitrogen dioxide (NO2) is an environmental oxidant, known to be associated with lung epithelial injury. In the present study, cellular pro-inflammatory responses following exposure to a brief high concentration of NO2 (45 ppm) were assessed, using normal human bronchial epithelial (NHBE) cells as an in vitro model of inhalation injury. Generation and release of pro-inflammatory mediators such as nitric oxide (NO), IL-8, TNF-alpha, IFN-gamma and IL-1beta were assessed at different time intervals following NO2 exposure. Effects of a pre-existing inflammatory condition was tested by treating the NHBE cells with different inflammatory cytokines such as IFN-gamma, IL-8, TNF-alpha, IL-1beta, either alone or in combination, before exposing them to NO2. Immunofluorescence studies confirmed oxidant-induced formation of 3-nitrotyrosine in the NO2-exposed cells. A marked increase in the levels of nitrite (as an index of NO) and IL-8 were observed in the NO2-exposed cells, which were further enhanced in the presence of the cytokines. Effects of various NO inhibitors combined, with immunofluorescence and Western blotting data, indicated partial contribution of the nitric oxide synthases (NOSs) toward the observed increase in nitrite levels. Furthermore, a significant increase in IL-1beta and TNF-alpha generation was observed in the NO2-exposed cells. Although NO2 exposure alone did induce slight cytotoxicity (<12%), but presence of inflammatory cytokines such as TNF-alpha and IFN-gamma resulted in an increased cell death (28-36%). These results suggest a synergistic role of inflammatory mediators, particularly of NO and IL-8, in NO2-mediated early cellular changes. Our results also demonstrate an increased sensitivity of the cytokine-treated NHBE cells toward NO2, which may have significant functional implications in vivo.

  11. Telomere dynamics in human mesenchymal stem cells after exposure to acute oxidative stress

    DEFF Research Database (Denmark)

    Harbo, M.; Koelvraa, S.; Serakinci, N.;

    2012-01-01

    A gradual shortening of telomeres due to replication can be measured using the standard telomere restriction fragments (TRF) assay and other methods by measuring the mean length of all the telomeres in a cell. In contrast, stress-induced telomere shortening, which is believed to be just...... as important for causing cellular senescence, cannot be measured properly using these methods. Stress-induced telomere shortening caused by, e.g. oxidative damage happens in a stochastic manner leaving just a few single telomeres critically short. It is now possible to visualize these few ultra-short telomeres...... due to the advantages of the newly developed Universal single telomere length assay (STELA), and we therefore believe that this method should be considered the method of choice when measuring the length of telomeres after exposure to oxidative stress. In order to test our hypothesis, cultured human...

  12. Oxidative DNA damage after acute exposure to arsenite and monomethylarsonous acid in biomethylation-deficient human cells.

    Science.gov (United States)

    Orihuela, Ruben; Kojima, Chikara; Tokar, Erik J; Person, Rachel J; Xu, Yuanyuan; Qu, Wei; Waalkes, Michael P

    2013-07-01

    The carcinogen inorganic arsenic (iAs) undergoes biomethylation (BMT) in some cells. The methylated metabolite, monomethylarsonous (MMA(3+)), may cause oxidative DNA damage (ODD). With chronic iAs exposure, BMT-competent cells show ODD while BMT-deficient do not. To further define these events, we studied ODD produced by acute iAs or MMA(3+) in the BMT-deficient human prostate cell line, RWPE-1. ODD, measured by the immuno-spin trapping method, was assessed after exposure to iAs or MMA(3+) alone, with the arsenic BMT inhibitor selenite or after glutathione (GSH) depletion. The expression of oxidative stress-related genes (HO-1, SOD-1, SOD-2, Nrf2 and Keap-1) was also assessed. Exposure to iAs at 24 h (0-20 µM), stimulated ODD only at levels above the LC50 of a 48 h exposure (17 µM). If iAs induced ODD, it also activated oxidative stress-related genes. Selenium did not alter iAs-induced ODD. MMA(3+) at 24 h (0-0.5 µM) caused ODD at levels below the LC50 of a 48 h exposure (1.5 µM), which were greatly increased by GSH depletion but not selenite. MMA(3+) induced ODD at levels not activating oxidant stress response genes. Overall, iAs induced ODD in BMT-deficient cells only at toxic levels. MMA(3+) caused ODD at non-toxic levels, independently of cellular BMT capacity and in a fashion not requiring further BMT.

  13. A Mathematical Model of the Human Small Intestine Following Acute Radiation and Burn Exposures

    Science.gov (United States)

    2016-08-01

    Act of 1979, as amended, Title 50, U.S.C., App. 2401 et seq. Violations of these export laws are subject to severe criminal penalties ...DTRA-TR-16-059 DISTRIBUTION A. Approved for public release: distribution is unlimited. Exposure to burn and radiation elicit epithelial cell death in...villus cells, promoting early cell death before migration is complete (Carter et al., 2014, Wolf et al., 1999). This response is fast and strong but

  14. Acute ozone exposure increases plasma prostaglandin F2 alpha in ozone-sensitive human subjects

    Energy Technology Data Exchange (ETDEWEB)

    Schelegle, E.S.; Adams, W.C.; Giri, S.N.; Siefkin, A.D.

    1989-07-01

    Twenty O/sub 3/-sensitive and /sup 2/O O/sub 3/-nonsensitive subjects participated in a study to investigate the effects of disparate O/sub 3/ sensitivity on plasma prostaglandin F2 alpha responses consequent to exposure to ambient O3 concentrations. Subjects were selected from a pool of 75 normal healthy college-aged males who had been previously exposed to 0.35 ppm O3 for 1 h at an exercising VE of 60 L/min. The selection criterion used was the observed decrement in FEV1 after the O/sub 3/ exposure: O/sub 3/-sensitive, FEV1 decrement greater than 24%; O/sub 3/-nonsensitive, FEV1 decrement less than 11%. Each subject was exposed to filtered air and to 0.20 and 0.35 ppm O/sub 3/ for 80 min while exercising at a VE of 50 L/min. These experimental protocols were divided into two 40-min sessions separated by a period of 4 to 10 min. PGF2 alpha, FVC, FEV1, and FEF25-75 were evaluated before, during, and after each protocol. SGaw and Vtg were measured before and after each protocol. Plasma PGF2 alpha was significantly increased in the O/sub 3/-sensitive group during and after the 0.35-ppm O/sub 3/ exposure.

  15. Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1982-08-01

    The present review provides an understanding of our current knowledge of the carcinogenic effect of low-dose radiation in man, and surveys the epidemiological studies of human populations exposed to nuclear explosions and medical radiation. Discussion centers on the contributions of quantitative epidemiology to present knowledge, the reliability of the dose-incidence data, and those relevant epidemiological studies that provide the most useful information for risk estimation of cancer-induction in man. Reference is made to dose-incidence relationships from laboratory animal experiments where they may obtain for problems and difficulties in extrapolation from data obtained at high doses to low doses, and from animal data to the human situation. The paper describes the methods of application of such epidemiological data for estimation of excess risk of radiation-induced cancer in exposed human populations, and discusses the strengths and limitations of epidemiology in guiding radiation protection philosophy and public health policy.

  16. Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation

    Energy Technology Data Exchange (ETDEWEB)

    Fabrikant, J.I.

    1982-08-01

    The present review provides an understanding of our current knowledge of the carcinogenic effect of low-dose radiation in man, and surveys the epidemiological studies of human populations exposed to nuclear explosions and medical radiation. Discussion centers on the contributions of quantitative epidemiology to present knowledge, the reliability of the dose-incidence data, and those relevant epidemiological studies that provide the most useful information for risk estimation of cancer-induction in man. Reference is made to dose-incidence relationships from laboratory animal experiments where they may obtain for problems and difficulties in extrapolation from data obtained at high doses to low doses, and from animal data to the human situation. The paper describes the methods of application of such epidemiological data for estimation of excess risk of radiation-induced cancer in exposed human populations, and discusses the strengths and limitations of epidemiology in guiding radiation protection philosophy and public health policy.

  17. In Vivo Nanodetoxication for Acute Uranium Exposure

    Directory of Open Access Journals (Sweden)

    Luis Guzmán

    2015-06-01

    Full Text Available Accidental exposure to uranium is a matter of concern, as U(VI is nephrotoxic in both human and animal models, and its toxicity is associated to chemical toxicity instead of radioactivity. We synthesized different PAMAM G4 and G5 derivatives in order to prove their interaction with uranium and their effect on the viability of red blood cells in vitro. Furthermore, we prove the effectiveness of the selected dendrimers in an animal model of acute uranium intoxication. The dendrimer PAMAM G4-Lys-Fmoc-Cbz demonstrated the ability to chelate the uranyl ion in vivo, improving the biochemical and histopathologic features caused by acute intoxication with uranium.

  18. Assessment of human exposures

    Energy Technology Data Exchange (ETDEWEB)

    Lebret, E. [RIVM-National Inst. of Public Health and Environmental Protection (Netherlands)

    1995-12-31

    This article describes some of the features of the assessment of human exposure to environmental pollutants in epidemiological studies. Since exposure assessment in air pollution epidemiology studies typically involve professionals from various backgrounds, interpretation of a concepts like `exposure` may vary. A brief descriptions is therefore given by way of introduction

  19. No Effects of Acute Exposure to Wi-Fi Electromagnetic Fields on Spontaneous EEG Activity and Psychomotor Vigilance in Healthy Human Volunteers.

    Science.gov (United States)

    Zentai, Norbert; Csathó, Árpád; Trunk, Attila; Fiocchi, Serena; Parazzini, Marta; Ravazzani, Paolo; Thuróczy, György; Hernádi, István

    2015-12-01

    Mobile equipment use of wireless fidelity (Wi-Fi) signal modulation has increased exponentially in the past few decades. However, there is inconclusive scientific evidence concerning the potential risks associated with the energy deposition in the brain from Wi-Fi and whether Wi-Fi electromagnetism interacts with cognitive function. In this study we investigated possible neurocognitive effects caused by Wi-Fi exposure. First, we constructed a Wi-Fi exposure system from commercial parts. Dosimetry was first assessed by free space radiofrequency field measurements. The experimental exposure system was then modeled based on real geometry and physical characteristics. Specific absorption rate (SAR) calculations were performed using a whole-body, realistic human voxel model with values corresponding to conventional everyday Wi-Fi exposure (peak SAR10g level was 99.22 mW/kg with 1 W output power and 100% duty cycle). Then, in two provocation experiments involving healthy human volunteers we tested for two hypotheses: 1. Whether a 60 min long 2.4 GHz Wi-Fi exposure affects the spectral power of spontaneous awake electroencephalographic (sEEG) activity (N = 25); and 2. Whether similar Wi-Fi exposure modulates the sustained attention measured by reaction time in a computerized psychomotor vigilance test (PVT) (N = 19). EEG data were recorded at midline electrode sites while volunteers watched a silent documentary. In the PVT task, button press reaction time was recorded. No measurable effects of acute Wi-Fi exposure were found on spectral power of sEEG or reaction time in the psychomotor vigilance test. These results indicate that a single, 60 min Wi-Fi exposure does not alter human oscillatory brain function or objective measures of sustained attention.

  20. Ultraviolet Radiation: Human Exposure and Health Risks.

    Science.gov (United States)

    Tenkate, Thomas D.

    1998-01-01

    Provides an overview of human exposure to ultraviolet radiation and associated health effects as well as risk estimates for acute and chronic conditions resulting from such exposure. Demonstrates substantial reductions in health risk that can be achieved through preventive actions. Also includes a risk assessment model for skin cancer. Contains 36…

  1. Acute exposure to long-chain fatty acids impairs {alpha}2-adrenergic receptor-mediated antilipolysis in human adipose tissue.

    Science.gov (United States)

    Polak, Jan; Moro, Cédric; Bessière, David; Hejnova, Jindra; Marquès, Marie A; Bajzova, Magda; Lafontan, Max; Crampes, Francois; Berlan, Michel; Stich, Vladimir

    2007-10-01

    The acute in vitro and in vivo effects of long-chain fatty acids (LCFAs) on the regulation of adrenergic lipolysis were investigated in human adipose tissue. The effect of a 2 h incubation, without or with LCFA (200 mumol/l), on basal and hormonally induced lipolysis was tested in vitro on isolated fat cells. The lipolytic response to epinephrine was enhanced by suppression of the antilipolytic alpha(2)-adrenergic effect. Then, healthy lean and obese male subjects performed a 45 min exercise bout at 50% of their heart rate reserve either after an overnight fast or 3 h after a high-fat meal (HFM: 95% fat, 5% carbohydrates). Subcutaneous adipose tissue lipolysis was measured by microdialysis in the presence or absence of an alpha-antagonist (phentolamine). In vivo, a HFM increased plasma levels of nonesterified fatty acids in lean and obese subjects. In both groups, the HFM did not alter hormonal responses to exercise. Under fasting conditions, the alpha(2)-adrenergic antilipolytic effect was more pronounced in obese than in lean subjects. The HFM totally suppressed the alpha(2)-adrenergic antilipolytic effect in lean and obese subjects during exercise. LCFAs per se, in vitro as well as in vivo, suppress alpha(2)-adrenergic-mediated antilipolysis in adipose tissue. LCFA-mediated suppression of antilipolytic pathways represents another mechanism whereby a high fat content in the diet might increase adipose tissue lipolysis.

  2. Human exposure to aluminium.

    Science.gov (United States)

    Exley, Christopher

    2013-10-01

    Human activities have circumvented the efficient geochemical cycling of aluminium within the lithosphere and therewith opened a door, which was previously only ajar, onto the biotic cycle to instigate and promote the accumulation of aluminium in biota and especially humans. Neither these relatively recent activities nor the entry of aluminium into the living cycle are showing any signs of abating and it is thus now imperative that we understand as fully as possible how humans are exposed to aluminium and the future consequences of a burgeoning exposure and body burden. The aluminium age is upon us and there is now an urgent need to understand how to live safely and effectively with aluminium.

  3. Acute symptoms during non-inhalation exposure to combinations of toluene, trichloroethylene, and n-hexane

    DEFF Research Database (Denmark)

    Bælum, Jesper

    1999-01-01

    To study the acute effect of exposure to a mixture of three commonly used solvents in humans using a route of exposure not involving the nose and lungs, in this case a gastrointestinal application....

  4. EFFECTS OF ACUTE PYRETHROID EXPOSURE ON THERMOREGULATION IN RATS.

    Science.gov (United States)

    Pyrethroid insecticides produce acute neurotoxicity in mammals. According to the FQPA mandate, the USEPA is required to consider the risk of cumulative toxicity posed to humans through exposure to pyrethroid mixtures. Thermoregulatory response (TR) is being used to determine if t...

  5. Human Exposure Database System (HEDS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Human Exposure Database System (HEDS) provides public access to data sets, documents, and metadata from EPA on human exposure. It is primarily intended for...

  6. Acute inhalation exposure of azodicarbonamide in the guinea pig.

    Science.gov (United States)

    Shopp, G M; Cheng, Y S; Gillett, N A; Bechtold, W E; Medinsky, M A; Hobbs, C H; Birnbaum, L S; Mauderly, J L

    1987-02-01

    Humans have been exposed to azodicarbonamide (ADA) by inhalation where bulk quantities of ADA are handled in the workplace. Responses of some workers have led to concern for the potential irritant and sensitizing properties of inhaled ADA. This study examined the effects of inhaling ADA on lung structure and function of guinea pigs during and after an acute exposure. Groups of 20 guinea pigs were exposed to each of 3 concentrations of ADA (19, 58, and 97 mg/m3), plus air as a control, for 1 hr. Pulmonary function was measured before exposure (baseline), during exposure, immediately after exposure and 24 hr after exposure. Dynamic compliance (Cdyn), total pulmonary resistance (RL), tidal volume (VT), respiratory frequency and minute volume were measured. In addition, gross necropsies and histological examinations of respiratory tract tissues were done either immediately following the exposure or 24 hr after exposure. There were no effects of ADA exposure on gross necropsy, histology, Cdyn, or RL. Some significant, concentration-related decreases in VT, respiratory frequency and minute volume were seen. The magnitudes of these changes were small: the largest change was seen in minute volume, amounting to a 24% decrease in the high concentration group. Inhalation exposure of guinea pigs to ADA at concentrations of up to 97 mg/m3 resulted in minor changes in pulmonary function without any changes in lung histology.

  7. Human health screening level risk assessments of tertiary-butyl acetate (TBAC): calculated acute and chronic reference concentration (RfC) and Hazard Quotient (HQ) values based on toxicity and exposure scenario evaluations.

    Science.gov (United States)

    Bus, James S; Banton, Marcy I; Faber, Willem D; Kirman, Christopher R; McGregor, Douglas B; Pourreau, Daniel B

    2015-02-01

    A screening level risk assessment has been performed for tertiary-butyl acetate (TBAC) examining its primary uses as a solvent in industrial and consumer products. Hazard quotients (HQ) were developed by merging TBAC animal toxicity and dose-response data with population-level, occupational and consumer exposure scenarios. TBAC has a low order of toxicity following subchronic inhalation exposure, and neurobehavioral changes (hyperactivity) in mice observed immediately after termination of exposure were used as conservative endpoints for derivation of acute and chronic reference concentration (RfC) values. TBAC is not genotoxic but has not been tested for carcinogenicity. However, TBAC is unlikely to be a human carcinogen in that its non-genotoxic metabolic surrogates tertiary-butanol (TBA) and methyl tertiary butyl ether (MTBE) produce only male rat α-2u-globulin-mediated kidney cancer and high-dose specific mouse thyroid tumors, both of which have little qualitative or quantitative relevance to humans. Benchmark dose (BMD)-modeling of the neurobehavioral responses yielded acute and chronic RfC values of 1.5 ppm and 0.3 ppm, respectively. After conservative modeling of general population and near-source occupational and consumer product exposure scenarios, almost all HQs were substantially less than 1. HQs exceeding 1 were limited to consumer use of automotive products and paints in a poorly ventilated garage-sized room (HQ = 313) and occupational exposures in small and large brake shops using no personal protective equipment or ventilation controls (HQs = 3.4-126.6). The screening level risk assessments confirm low human health concerns with most uses of TBAC and indicate that further data-informed refinements can address problematic health/exposure scenarios. The assessments also illustrate how tier-based risk assessments using read-across toxicity information to metabolic surrogates reduce the need for comprehensive animal testing.

  8. Pulmonary Inflammatory Responses to Acute Meteorite Dust Exposures - to Acute Meteorite Dust Exposures - Exploration

    Science.gov (United States)

    Harrington, A. D.; McCubbin, F. M.; Kaur, J.; Smirnov, A.; Galdanes, K.; Schoonen, M. A. A.; Chen, L. C.; Tsirka, S. E.; Gordon, T.

    2017-01-01

    New initiatives to begin lunar and martian colonization within the next few decades are illustrative of the resurgence of interest in space travel. One of NASA's major concerns with extended human space exploration is the inadvertent and repeated exposure to unknown dust. This highly interdisciplinary study evaluates both the geochemical reactivity (e.g. iron solubility and acellular reactive oxygen species (ROS) generation) and the relative toxicity (e.g. in vitro and in vivo pulmonary inflammation) of six meteorite samples representing either basalt or regolith breccia on the surface of the Moon, Mars, and Asteroid 4Vesta. Terrestrial mid-ocean ridge basalt (MORB) is also used for comparison. The MORB demonstrated higher geochemical reactivity than most of the meteorite samples but caused the lowest acute pulmonary inflammation (API). Notably, the two martian meteorites generated some of the highest API but only the basaltic sample is significantly reactive geochemically. Furthermore, while there is a correlation between a meteorite's soluble iron content and its ability to generate acellular ROS, there is no direct correlation between a particle's ability to generate ROS acellularly and its ability to generate API. However, assorted in vivo API markers did demonstrate strong positive correlations with increasing bulk Fenton metal content. In summary, this comprehensive dataset allows for not only the toxicological evaluation of astromaterials but also clarifies important correlations between geochemistry and health.

  9. Acute human schistosomiasis mansoni

    Directory of Open Access Journals (Sweden)

    Ana Rabello

    1995-04-01

    Full Text Available The acute schistosomiasis is the toxemic disease that follow the Schistosoma cercariae active penetration trough screen in the immunologicaly naive vertebrate host. The clinical picture starts two to eight weeks after the first contact with the contaminated water. Susceptible patients present a syndrome comprising fever, diarrhea, toxemia and hepatosplenomegaly. Diagnosis is based on epidemiological and clinical features, presence of Schistosoma eggs in the feces, enlargement of abdominal lymph nodes by ultrasonography and by detection of high antibodies levels against the antigen keyhole limpet haemocyanin. Different rates of cure have been observed with specific medication and for the most severe clinical presentations the use of steroids reduces the systemic and allergic manifestations.

  10. Estrogen Effects after a Crush Muscle Injury and Acute Exposure to Hypobaric Hypoxia

    Science.gov (United States)

    2015-03-01

    et al. Intermittent hypobaric hypoxia increases the ability of neutrophils to generate superoxide anion in humans. Clin Exp Pharmacol Physiol. 2003...AFRL-SA-WP-TR-2015-0007 Estrogen Effects after a Crush Muscle Injury and Acute Exposure to Hypobaric Hypoxia Dr. Barbara St...after a Crush Muscle Injury and Acute Exposure to Hypobaric Hypoxia 5a. CONTRACT NUMBER FA7014-10-2-0001 5b. GRANT NUMBER 5c. PROGRAM

  11. Identification of Differential Gene Expression Patterns after Acute Exposure to High and Low Doses of Low-LET Ionizing Radiation in a Reconstituted Human Skin Tissue

    Energy Technology Data Exchange (ETDEWEB)

    Tilton, Susan C.; Markillie, Lye Meng; Hays, Spencer; Taylor, Ronald C.; Stenoien, David L.

    2016-11-01

    Our goal here was to identify dose and temporal dependent radiation responses in a complex tissue, reconstituted human skin. Direct sequencing of RNA (RNA-seq) was used to quantify altered transcripts following exposure to 0.1, 2 and 10 Gy of ionizing radiation at 3 and 8 hours. These doses include a low dose in the range of some medical diagnostic procedures (0.1 Gy), a dose typically received during radiotherapy (2.0 Gy) and a lethal dose (10 Gy). These doses could be received after an intentional or accidental radiation exposure and biomarkers are needed to rapidly and accurately triage exposed individuals. A total of 1701 genes were deemed to be significantly affected by high dose radiation exposure with the majority of genes affected at 10 Gy. A group of 29 genes including GDF15, BBC3, PPM1D, FDXR, GADD45A, MDM2, CDKN1A, TP53INP1, CYCSP27, SESN1, SESN2, PCNA, and AEN were similarly altered at both 2 and 10 Gy, but not 0.1 Gy, at multiple time points. A much larger group of up regulated genes, including those involved in inflammatory responses, was significantly altered only after a 10 Gy exposure. At high doses, down regulated genes were associated with cell cycle regulation and exhibited an apparent linear response between 2 and 10 Gy. While only a handful of genes were significantly affected by 0.1 Gy exposure using stringent statistical filters, groups of related genes regulating cell cycle progression and inflammatory responses consistently exhibited opposite trends in their regulation compared to the high dose exposures. Differential regulation of PLK1 signaling at low and high doses was confirmed using qRT-PCR. These results indicate that some alterations in gene expression are qualitatively different at low and high doses of radiation in this model system.

  12. Endocrine responses in the rhesus monkey during acute cold exposure

    Energy Technology Data Exchange (ETDEWEB)

    Lotz, W.G.; Saxton, J.L. (Naval Aerospace Medical Research Lab., Pensacola, FL (United States))

    1991-03-11

    The authors studied five young male rhesus monkeys (Macaca mulatta), 3.4 to 6.7 kg, to determine the relationship between fluid balance hormones and urine production during acute, dry cold exposure. Each monkey served as its own control in duplicate experimental sessions at 6C or 26C. A 6-h experimental session consisted of 120 min equilibration at 26C, 120 min experimental exposure, and 120 min recovery at 26C. Urinary and venous catheters were inserted on the morning of a session. Rectal (Tre) and skin temperatures were monitored continuously. Blood samples were taken at 0, 30, 60 and 120 min of exposure, and at 60 min postexposure. Plasma was analyzed for arginine vasopressin (AVP), atrial natriuretic factor (ANF), plasma renin activity (PRA), plasma aldosterone (PA), and osmolality. Urine samples were analyzed for osmolality, electrolytes, and creatinine. Mean Tre was 1.6C lower after 120 min at 6C than at 26C. Urine volume and osmolality were not altered by cold exposure, as they are in humans and rats. Vasopressin and PA increased sharply, with mean plasma levels in monkeys exposed to cold more than threefold and tenfold, respectively, the levels in monkeys exposed at 26C. In contrast, ANF, PRA, and plasma osmolality were not significantly changed by cold exposure. The absence of a cold-induced diuresis in the monkey may be related to the marked increase in plasma AVP level.

  13. Repeated exposure to conditioned fear stress increases anxiety and delays sleep recovery following exposure to an acute traumatic stressor

    Directory of Open Access Journals (Sweden)

    Benjamin N Greenwood

    2014-10-01

    Full Text Available Repeated stressor exposure can sensitize physiological responses to novel stressors and facilitate the development of stress-related psychiatric disorders including anxiety. Disruptions in diurnal rhythms of sleep-wake behavior accompany stress-related psychiatric disorders and could contribute to their development. Complex stressors that include fear-eliciting stimuli can be a component of repeated stress experienced by humans, but whether exposure to repeated fear can prime the development of anxiety and sleep disturbances is unknown. In the current study, adult male F344 rats were exposed to either control conditions or repeated contextual fear conditioning for 22 days followed by exposure to either no, mild (10, or severe (100 acute uncontrollable tail shock stress. Exposure to acute stress produced anxiety-like behavior as measured by a reduction in juvenile social exploration and exaggerated shock-elicited freezing in a novel context. Prior exposure to repeated fear enhanced anxiety-like behavior as measured by shock-elicited freezing, but did not alter social exploratory behavior. The potentiation of anxiety produced by prior repeated fear was temporary; exaggerated fear was present 1 day but not 4 days following acute stress. Interestingly, exposure to acute stress reduced REM and NREM sleep during the hours immediately following acute stress. This initial reduction in sleep was followed by robust REM rebound and diurnal rhythm flattening of sleep / wake behavior. Prior repeated fear extended the acute stress-induced REM and NREM sleep loss, impaired REM rebound, and prolonged the flattening of the diurnal rhythm of NREM sleep following acute stressor exposure. These data suggest that impaired recovery of sleep / wake behavior following acute stress could contribute to the mechanisms by which a history of prior repeated stress increases vulnerability to subsequent novel stressors and stress-related disorders.

  14. Effects of acute electromagnetic fields exposure on the interhemispheric homotopic functional connectivity during resting state.

    Science.gov (United States)

    Lv, Bin; Shao, Qing; Chen, Zhiye; Ma, Lin; Wu, Tongning

    2015-08-01

    In this paper, we aimed to investigate the possible effects of acute radiofrequency electromagnetic fields (EMF) on the interhemispheric homotopic functional connectivity with resting state functional magnetic resonance imaging (fMRI) technique. We designed a controllable LTE-related EMF exposure environment at 2.573 GHz and performed the 30 min real/sham exposure experiments on human brain under the safety limits. The resting state fMRI signals were collected before and after EMF exposure. Then voxel-mirrored homotopic connectivity method was utilized to evaluate the acute effects of LTE EMF exposure on the homotopic functional connectivity between two human hemispheres. Based on our previous research, we further demonstrated that the 30 min short-term LTE EMF exposure would modulate the interhemispheric homotopic functional connectivity in resting state around the medial frontal gyrus and the paracentral lobule during the real exposure.

  15. Genome-wide Gene Expression Profiling of Acute Metal Exposures in Male Zebrafish

    Science.gov (United States)

    2014-10-23

    and methods Experimental overview Fig. 1 shows the design scheme. Fish exposures Briefly, adult,male zebrafishwere exposed to concentrations of each...before and after exposures. Initially 25 adult (6–9 months) presumptive male zebrafish were selected per condition to ensure that 20 male fish were...evaluated in whole adult male zebra ???sh following acute 24 h high dose exposure to three metals with known human health risks. Male adult zebra ???sh

  16. Human Exposure Modeling - Databases to Support Exposure Modeling

    Science.gov (United States)

    Human exposure modeling relates pollutant concentrations in the larger environmental media to pollutant concentrations in the immediate exposure media. The models described here are available on other EPA websites.

  17. A novel antibody-based biomarker for chronic algal toxin exposure and sub-acute neurotoxicity

    Science.gov (United States)

    Lefebvre, Kathi A.; Frame, Elizabeth R.; Gulland, Frances; Hansen, John D.; Kendrick, Preston S.; Beyer, Richard P.; Bammler, Theo K.; Farin, Frederico M.; Hiolski, Emma M.; Smith, Donald R.; Marcinek, David J.

    2012-01-01

    The neurotoxic amino acid, domoic acid (DA), is naturally produced by marine phytoplankton and presents a significant threat to the health of marine mammals, seabirds and humans via transfer of the toxin through the foodweb. In humans, acute exposure causes a neurotoxic illness known as amnesic shellfish poisoning characterized by seizures, memory loss, coma and death. Regular monitoring for high DA levels in edible shellfish tissues has been effective in protecting human consumers from acute DA exposure. However, chronic low-level DA exposure remains a concern, particularly in coastal and tribal communities that subsistence harvest shellfish known to contain low levels of the toxin. Domoic acid exposure via consumption of planktivorous fish also has a profound health impact on California sea lions (Zalophus californianus) affecting hundreds of animals yearly. Due to increasing algal toxin exposure threats globally, there is a critical need for reliable diagnostic tests for assessing chronic DA exposure in humans and wildlife. Here we report the discovery of a novel DA-specific antibody response that is a signature of chronic low-level exposure identified initially in a zebrafish exposure model and confirmed in naturally exposed wild sea lions. Additionally, we found that chronic exposure in zebrafish caused increased neurologic sensitivity to DA, revealing that repetitive exposure to DA well below the threshold for acute behavioral toxicity has underlying neurotoxic consequences. The discovery that chronic exposure to low levels of a small, water-soluble single amino acid triggers a detectable antibody response is surprising and has profound implications for the development of diagnostic tests for exposure to other pervasive environmental toxins.

  18. Effects of Acute Exposures to Carbon Dioxide upon Cognitive Functions

    Science.gov (United States)

    Ryder, V. E.; Scully, R. R.; Alexander, D. J.; Lam, C. W.; Young, M.; Satish, U.; Basner, M.

    2017-01-01

    Carbon dioxide (CO2) originates from human metabolism and typically remains about 10-fold higher in concentration on the International Space Station (ISS) than at the earth's surface. There have been recurring complaints by crew members of episodes of "mental viscosity" adversely affecting their performance, and there is evidence from the ISS that associates CO2 levels with reports of headaches by crewmembers. Consequently, flight rules have been employed to control CO2 below 3 mm Hg, which is well below the existing Spacecraft Maximum Allowable Concentration (SMAC) of 10 mm Hg for 24-hour exposures, and 5.3 mm Hg for exposures of 7 to 180 days. Headaches, while sometime debilitating themselves, are also symptoms that can provide evidence that physiological defense mechanisms have been breached, and there is evidence that CO2 has effects at levels below the threshold for headaches. This concern appears to be substantiated in reports that CO2 at concentrations below 2 mm Hg substantially reduced some cognitive functions that are associated with the ability to make complex decisions in conditions that are characterized by volatility, uncertainty, complexity, ambiguity, and delayed feedback. These are conditions that could be encountered by crews in off-nominal situations or during the first missions beyond low earth orbit. Therefore, we set out to determine if decision-making under volatile, uncertain, confusing and ambiguous circumstances, where feedback is delayed or absent, is correlated with low levels of CO2 during acute exposures (several hours) in crew-like subjects and to determine if additional cognitive domains are sensitive to concentrations of CO2 at, or below, current ISS levels by using a test battery that is currently available onboard ISS. We enrolled 22 volunteers (8 females, 14 males) between the ages of 30-55 (38.8 +/- 7.0) years whose training and professional experience reflect that of the astronaut corps. Subjects were divided among 4 study

  19. ACUTE BEHAVORIAL EFFECTS FROM EXPOSURE TO TWO-STROKE ENGINE EXHAUST

    Science.gov (United States)

    Benefits of changing from two-stroke to four-stroke engines (and other remedial requirements) can be evaluated (monetized) from the standpoint of acute behavioral effects of human exposure to exhaust from these engines. The monetization process depends upon estimates of the magn...

  20. The effect of chronic ammonia exposure on acute phase proteins, immunoglobulin and cytokines in laying hens

    Science.gov (United States)

    Ammonia is a potential health hazard to both humans and animals, causing systemic low-grade inflammation based on its levels and durations. The objective of this study was to examine the effect of 45 weeks of exposure to 30 ppm NH3 on the concentrations of acute phase proteins, immunoglobulins and c...

  1. In vitro and in vivo models of acute alcohol exposure

    Institute of Scientific and Technical Information of China (English)

    Angela Dolganiuc; Gyongyi Szabo

    2009-01-01

    Alcohol abuse is a global problem due to the financial burden on society and the healthcare system. While the harmful health effects of chronic alcohol abuse are well established, more recent data suggest that acute alcohol consumption also affects human wellbeing. Thus, there is a need for research models in order to fully understand the effect of acute alcohol abuse on different body systems and organs. The present manuscript summarizes the interdisciplinary advantages and disadvantages of currently available human and non-human models of acute alcohol abuse,and identifies their suitability for biomedical research.

  2. Differences of acute versus chronic ethanol exposure on anxiety-like behavioral responses in zebrafish.

    Science.gov (United States)

    Mathur, Priya; Guo, Su

    2011-06-01

    Zebrafish, a vertebrate model organism amenable to high throughput screening, is an attractive system to model and study the mechanisms underlying human diseases. Alcoholism and alcoholic medical disorders are among the most debilitating diseases, yet the mechanisms by which ethanol inflicts the disease states are not well understood. In recent years zebrafish behavior assays have been used to study learning and memory, fear and anxiety, and social behavior. It is important to characterize the effects of ethanol on zebrafish behavioral repertoires in order to successfully harvest the strength of zebrafish for alcohol research. One prominent effect of alcohol in humans is its effect on anxiety, with acute intermediate doses relieving anxiety and withdrawal from chronic exposure increasing anxiety, both of which have significant contributions to alcohol dependence. In this study, we assess the effects of both acute and chronic ethanol exposure on anxiety-like behaviors in zebrafish, using two behavioral paradigms, the Novel Tank Diving Test and the Light/Dark Choice Assay. Acute ethanol exposure exerted significant dose-dependent anxiolytic effects. However, withdrawal from repeated intermittent ethanol exposure disabled recovery from heightened anxiety. These results demonstrate that zebrafish exhibit different anxiety-like behavioral responses to acute and chronic ethanol exposure, which are remarkably similar to these effects of alcohol in humans. Because of the accessibility of zebrafish to high throughput screening, our results suggest that genes and small molecules identified in zebrafish will be of relevance to understand how acute versus chronic alcohol exposure have opposing effects on the state of anxiety in humans. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Occupational exposure to solvents and acute myeloid leukemia

    DEFF Research Database (Denmark)

    Talibov, Madar; Lehtinen-Jacks, Susanna; Martinsen, Jan Ivar;

    2014-01-01

    OBJECTIVE: The aim of the current study was to assess the relation between occupational exposure to solvents and the risk of acute myeloid leukemia (AML). METHODS: Altogether, this study comprises 15 332 incident cases of AML diagnosed in Finland, Norway, Sweden and Iceland from 1961-2005 and 76...

  4. Health Impacts from Acute Radiation Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Strom, Daniel J.

    2003-09-30

    Absorbed doses above1-2 Gy (100-200 rads) received over a period of a day or less lead to one or another of the acute radiation syndromes. These are the hematopoietic syndrome, the gastrointestinal (GI) syndrome, the cerebrovascular (CV) syndrome, the pulmonary syndrome, or the cutaneous syndrome. The dose that will kill about 50% of the exposed people within 60 days with minimal medical care, LD50-60, is around 4.5 Gy (450 rads) of low-LET radiation measured free in air. The GI syndrome may not be fatal with supportive medical care and growth factors below about 10 Gy (1000 rads), but above this is likely to be fatal. Pulmonary and cutaneous syndromes may or may not be fatal, depending on many factors. The CV syndrome is invariably fatal. Lower acute doses, or protracted doses delivered over days or weeks, may lead to many other health outcomes than death. These include loss of pregnancy, cataract, impaired fertility or temporary or permanent sterility, hair loss, skin ulceration, local tissue necrosis, developmental abnormalities including mental and growth retardation in persons irradiated as children or fetuses, radiation dermatitis, and other symptoms listed in Table 2 on page 12. Children of parents irradiated prior to conception may experience heritable ill-health, that is, genetic changes from their parents. These effects are less strongly expressed than previously thought. Populations irradiated to high doses at high dose rates have increased risk of cancer incidence and mortality, taken as about 10-20% incidence and perhaps 5-10% mortality per sievert of effective dose of any radiation or per gray of whole-body absorbed dose low-LET radiation. Cancer risks for non-uniform irradiation will be less.

  5. Prenatal and acute cocaine exposure affects neural responses and habituation to visual stimuli

    Directory of Open Access Journals (Sweden)

    Elizabeth Brooke Riley

    2015-08-01

    Full Text Available Psychostimulants have many effects on visual function, from adverse, following acute and prenatal exposure to therapeutic, on attention deficit. To determine the impact of prenatal and acute cocaine exposure on visual processing, we studied neuronal responses to visual stimuli in two brain regions of a transgenic larval zebrafish expressing the calcium indicator GCaMP-HS. We found that both red light (LF and dark (DF flashes elicited similar responses in the optic tectum neuropil (TOn, while the dorsal telencephalon (dTe responded only to LF. Acute cocaine (0.5 μM reduced neuronal responses to LF in both brain regions but did not affect responses to DF. Repeated stimulus presentation led to habituation of dTe neurons to LF. Acute cocaine prevented habituation. TOn habituated to DF, but not LF, and DF habituation was not modified by cocaine. Remarkably, prenatal cocaine exposure prevented the effects of acute cocaine on LF response amplitude and habituation later in development in both brain regions, but did not affect DF responses. We discovered that, in spite of similar neural responses to LF and DF in the TO (superior colliculus in mammals, responses to LF are more complex, involving dTe (homologous to the cerebral cortex, and are more vulnerable to cocaine. Our results demonstrate that acute cocaine exposure affects visual processing differentially by brain region, and that prenatal cocaine exposure modifies zebrafish visual processing in multiple structures in a stimulus-dependent manner. These findings are in accordance with the major role that the optic tectum and cerebral cortex play in sustaining visual attention, and support the hypothesis that modification of these areas by prenatal cocaine exposure may be responsible for visual deficits noted in humans. This model offers new methodological approaches for studying the adverse and therapeutic effects of psychostimulants on attention, and for the development of new pharmacological

  6. Acute liver failure associated with occupational exposure to tetrachloroethylene.

    Science.gov (United States)

    Shen, Chuan; Zhao, Cai-Yan; Liu, Fang; Wang, Ya-Dong; Wang, Wei

    2011-01-01

    Tetrachloroethylene is a chlorinated solvent that is primarily used in dry cleaning and degreasing operations. Although the hepatotoxicity caused by tetrachloroethylene has been well documented in literature, it is rarely considered as a cause of acute liver failure. We report a case of a 39-yr-old man who was admitted to our hospital for acute liver failure due to tetrachloroethylene exposure. Histological examination of the liver revealed massive hepatic necrosis, prominently, in zone 3 of the hepatic lobules. The patient underwent supportive treatment along with 3 sessions of plasmapheresis, and consequently, he presented a favorable outcome. Repeat liver biopsy performed 6 months after the patient's discharge showed architectural distortion with postnecrotic cirrhosis. Physicians should be aware of the possibility of acute liver failure induced by tetrachloroethylene. Early plasmapheresis can be effective for individuals with sufficient capacity for hepatocyte regeneration.

  7. Cancer Events After Acute or Chronic Exposure to Sulfur Mustard: A Review of the Literature

    Science.gov (United States)

    Razavi, Seyed Mansour; Abdollahi, Mohammad; Salamati, Payman

    2016-01-01

    Background: Sulfur mustard (SM) has been considered as a carcinogen in the laboratory studies. However, its carcinogenic effects on human beings were not well discussed. The main purpose of our study is to assess carcinogenesis of SM following acute and/or chronic exposures in human beings. Methods: The valid scientific English and Persian databases including PubMed, Web of Science, Scopus, IranMedex, and Irandoc were searched and the collected papers reviewed. The used keywords were in two languages: English and Persian. The inclusion criteria were the published original articles indexed in above-mentioned databases. Eleven full-texts out of 296 articles were found relevant and then assessed. Results: Studies on the workers of the SM factories during the World Wars showed that the long-term chronic exposure to mustards can cause a variety of cancers in the organs such as oral cavity, larynx, lung, and skin. Respiratory system was the most important affected system. Acute single exposure to SM was assumed as the carcinogenic inducer in the lung and blood and for few cancers including basal cell carcinoma and squamous cell carcinoma. Conclusions: SM is a proven carcinogen in chronic situations although data are not enough to strongly conclude in acute exposure. PMID:27280012

  8. Community Engagement in Observational Human Exposure Studies

    Science.gov (United States)

    Although observational human exposure studies do not deliberately expose participants to chemicals or environmental conditions, merely involving people as research participants and conducting research inside homes raises ethical issues. Community engagement offers a promising st...

  9. PARTNERING TO IMPROVE HUMAN EXPOSURE METHODS

    Science.gov (United States)

    Methods development research is an application-driven scientific area that addresses programmatic needs. The goals are to reduce measurement uncertainties, address data gaps, and improve existing analytical procedures for estimating human exposures. Partnerships have been develop...

  10. Arsenic Exposure and the Induction of Human Cancers

    Directory of Open Access Journals (Sweden)

    Victor D. Martinez

    2011-01-01

    Full Text Available Arsenic is a metalloid, that is, considered to be a human carcinogen. Millions of individuals worldwide are chronically exposed through drinking water, with consequences ranging from acute toxicities to development of malignancies, such as skin and lung cancer. Despite well-known arsenic-related health effects, the molecular mechanisms involved are not fully understood; however, the arsenic biotransformation process, which includes methylation changes, is thought to play a key role. This paper explores the relationship of arsenic exposure with cancer development and summarizes current knowledge of the potential mechanisms that may contribute to the neoplastic processes observed in arsenic exposed human populations.

  11. Prenatal and acute cocaine exposure affects neural responses and habituation to visual stimuli.

    Science.gov (United States)

    Riley, Elizabeth; Kopotiyenko, Konstantin; Zhdanova, Irina

    2015-01-01

    Psychostimulants have many effects on visual function, from adverse following acute and prenatal exposure to therapeutic on attention deficit. To determine the impact of prenatal and acute cocaine exposure on visual processing, we studied neuronal responses to visual stimuli in two brain regions of a transgenic larval zebrafish expressing the calcium indicator GCaMP-HS. We found that both red light (LF) and dark (DF) flashes elicited similar responses in the optic tectum neuropil (TOn), while the dorsal telencephalon (dTe) responded only to LF. Acute cocaine (0.5 μM) reduced neuronal responses to LF in both brain regions but did not affect responses to DF. Repeated stimulus presentation (RSP) led to habituation of dTe neurons to LF. Acute cocaine prevented habituation. TOn habituated to DF, but not LF, and DF habituation was not modified by cocaine. Remarkably, prenatal cocaine exposure (PCE) prevented the effects of acute cocaine on LF response amplitude and habituation later in development in both brain regions, but did not affect DF responses. We discovered that, in spite of similar neural responses to LF and DF in the TO (superior colliculus in mammals), responses to LF are more complex, involving dTe (homologous to the cerebral cortex), and are more vulnerable to cocaine. Our results demonstrate that acute cocaine exposure affects visual processing differentially by brain region, and that PCE modifies zebrafish visual processing in multiple structures in a stimulus-dependent manner. These findings are in accordance with the major role that the optic tectum and cerebral cortex play in sustaining visual attention, and support the hypothesis that modification of these areas by PCE may be responsible for visual deficits noted in humans. This model offers new methodological approaches for studying the adverse and therapeutic effects of psychostimulants on attention, and for the development of new pharmacological interventions.

  12. Acute versus repeated chocolate exposure: effects on intake and cravings in restrained and unrestrained eaters.

    Science.gov (United States)

    Coelho, Jennifer S; Nederkoorn, Chantal; Jansen, Anita

    2014-04-01

    The cue-reactivity model, which is based on conditioning processes, posits that repeated food exposure (in the absence of consumption) should decrease cue reactivity. To examine whether repeated chocolate exposure attenuates cravings and intake, relative to those exposed to an acute cue, a 2 (repeated vs acute cue) × 2 (restrained vs unrestrained eaters) design was employed. Fifty female participants were recruited. Repeated exposure reduced cravings in unrestrained eaters (relative to acute exposure), but increased cravings in restrained eaters. An interaction between restraint and exposure emerged on intake, such that restrained eaters ate less after acute exposure than did unrestrained eaters.

  13. Human bocavirus and acute wheezing in children.

    Science.gov (United States)

    Allander, Tobias; Jartti, Tuomas; Gupta, Shawon; Niesters, Hubert G M; Lehtinen, Pasi; Osterback, Riikka; Vuorinen, Tytti; Waris, Matti; Bjerkner, Annelie; Tiveljung-Lindell, Annika; van den Hoogen, Bernadette G; Hyypiä, Timo; Ruuskanen, Olli

    2007-04-01

    Human bocavirus is a newly discovered parvovirus. It has been detected primarily in children with acute lower respiratory tract infection, but its occurrence, clinical profile, and role as a causative agent of respiratory tract disease are not clear. We investigated the presence of human bocavirus by quantitative polymerase chain reaction of nasopharyngeal aspirate specimens and selected serum samples obtained from 259 children (median age, 1.6 years) who had been hospitalized for acute expiratory wheezing. The samples were analyzed for 16 respiratory viruses by polymerase chain reaction, virus culture, antigen detection, and serological assays. At least 1 potential etiologic agent was detected in 95% of children, and >1 agent was detected in 34% of children. Human bocavirus was detected in 49 children (19%). A large proportion of the cases were mixed infections with other viruses, but human bocavirus was the only virus detected in 12 children (5%). High viral loads of human bocavirus were noted mainly in the absence of other viral agents, suggesting a causative role for acute wheezing. In addition, infections that had uncertain clinical relevance and low viral loads were prevalent. Human bocavirus DNA was frequently detected in serum specimens obtained from patients with acute wheezing, suggesting systemic infection. Human bocavirus is prevalent among children with acute wheezing and can cause systemic infection. Results suggest a model for bocavirus infection in which high viral loads are potentially associated with respiratory symptoms and low viral loads indicate asymptomatic shedding. Therefore, quantitative polymerase chain reaction analysis may be important for additional studies of human bocavirus.

  14. Modelling Human Exposure to Chemicals in Food

    NARCIS (Netherlands)

    Slob W

    1993-01-01

    Exposure to foodborne chemicals is often estimated using the average consumption pattern in the human population. To protect the human population instead of the average individual, however, interindividual variability in consumption behaviour must be taken into account. This report shows how food

  15. Assessment of the Effects of Acute and Repeated Exposure to Blast Overpressure in Rodents: Towards a Greater Understanding of Blast and the Potential Ramifications for Injury in Humans Exposed to Blast

    Directory of Open Access Journals (Sweden)

    Stephen Thomas Ahlers

    2012-03-01

    Full Text Available Mild traumatic brain injury (mTBI resulting from exposure to improvised explosive devices (IEDs has fueled a requirement to develop animals models that mirror this condition using exposure to blast overpressure (BOP. En route to developing a model of repeated exposure to BOP we sought to initially characterize the effects of acute BOP exposure in rodents, focusing specifically on the levels of BOP exposure that produced clinical mTBI symptoms. We first measured BOP effects on gross motor function on a balance beam. Separate groups of unanesthetized rats were exposed (in different orientations to 40 kPa, 75 kPa and 120 kPa BOP exposure inside a pneumatically driven shock tube. Results demonstrated that rats exposed to 120 kPa demonstrated transient alterations or loss of consciousness indicated by a transient loss of righting and by increased latencies on the balance beam. The 120 kPa exposure was the threshold for overt pathology for acute BOP exposure with approximately 30% of rats presenting with evidence of subdural hemorrhage and cortical contusions. All animals exposed to 120 kPa BOP manifested evidence of significant pulmonary hemorrhage. Anterograde memory deficits were observed in rats exposed to 75 kPa facing the BOP wave and rats exposed to 120 kPa in the lateral (side orientation. We next assessed repeated exposure to either lateral or frontal 40 kPa BOP in anesthetized rats, once per day for 12 days. Results showed that repeated exposure in the frontal, but not side, orientation to the BOP wave produced a transitory learning deficit on a Morris water maze (MWM task as shown by significantly longer latencies to reach the submerged platform in the second and third blocks of a four block session. Implications of these data are discussed in relation to the manifestation of mTBI in military personnel exposed to IEDs. Finally, we suggest that there are multiple types of brain injury from blast.

  16. Limited inflammatory response in rats after acute exposure to a silicon carbide nanoaerosol

    Science.gov (United States)

    Laloy, J.; Lozano, O.; Alpan, L.; Masereel, B.; Toussaint, O.; Dogné, J. M.; Lucas, S.

    2015-08-01

    Inhalation represents the major route of human exposure to manufactured nanomaterials (NMs). Assessments are needed about the potential risks of NMs from inhalation on different tissues and organs, especially the respiratory tract. The aim of this limited study is to determine the potential acute pulmonary toxicity in rats exposed to a dry nanoaerosol of silicon carbide (SiC) nanoparticles (NPs) in a whole-body exposure (WBE) model. The SiC nanoaerosol is composed of a bimodal size distribution of 92.8 and 480 nm. The exposure concentration was 4.91 mg/L, close to the highest recommended concentration of 5 mg/L by the Organisation for Economic Co-operation and Development. Rats were exposed for 6 h to a stable and reproducible SiC nanoaerosol under real-time measurement conditions. A control group was exposed to the filtered air used to create the nanoaerosol. Animals were sacrificed immediately, 24 or 72 h after exposure. The bronchoalveolar lavage fluid from rat lungs was recovered. Macrophages filled with SiC NPs were observed in the rat lungs. The greatest load of SiC and macrophages filled with SiC were observed on the rat lungs sacrificed 24 h after acute exposure. A limited acute inflammatory response was found up to 24 h after exposure characterized by a lactate dehydrogenase and total protein increase or presence of inflammatory cells in pulmonary lavage. For this study a WBE model has been developed, it allows the simultaneous exposure of six rats to a nanoaerosol and six rats to clean-filtered air. The nanoaerosol was generated using a rotating brush system (RBG-1000) and analyzed with an electrical low pressure impactor in real time.

  17. Limited inflammatory response in rats after acute exposure to a silicon carbide nanoaerosol

    Energy Technology Data Exchange (ETDEWEB)

    Laloy, J., E-mail: julie.laloy@unamur.be [University of Namur (UNamur), Department of Pharmacy, Namur Nanosafety Centre (NNC), Namur Research Institute for Life Sciences NARILIS (Belgium); Lozano, O. [University of Namur (UNamur), Research Centre in Physics of Matter and Radiation (PMR), Namur Nanosafety Centre NNC, Namur Research Institute for Life Sciences NARILIS (Belgium); Alpan, L.; Masereel, B. [University of Namur (UNamur), Department of Pharmacy, Namur Nanosafety Centre (NNC), Namur Research Institute for Life Sciences NARILIS (Belgium); Toussaint, O. [University of Namur (UNamur), Laboratory of Cellular Biochemistry and Biology (URBC), Namur Nanosafety Centre NNC, Namur Research Institute for Life Sciences NARILIS (Belgium); Dogné, J. M. [University of Namur (UNamur), Department of Pharmacy, Namur Nanosafety Centre (NNC), Namur Research Institute for Life Sciences NARILIS (Belgium); Lucas, S. [University of Namur (UNamur), Research Centre in Physics of Matter and Radiation (PMR), Namur Nanosafety Centre NNC, Namur Research Institute for Life Sciences NARILIS (Belgium)

    2015-08-15

    Inhalation represents the major route of human exposure to manufactured nanomaterials (NMs). Assessments are needed about the potential risks of NMs from inhalation on different tissues and organs, especially the respiratory tract. The aim of this limited study is to determine the potential acute pulmonary toxicity in rats exposed to a dry nanoaerosol of silicon carbide (SiC) nanoparticles (NPs) in a whole-body exposure (WBE) model. The SiC nanoaerosol is composed of a bimodal size distribution of 92.8 and 480 nm. The exposure concentration was 4.91 mg/L, close to the highest recommended concentration of 5 mg/L by the Organisation for Economic Co-operation and Development. Rats were exposed for 6 h to a stable and reproducible SiC nanoaerosol under real-time measurement conditions. A control group was exposed to the filtered air used to create the nanoaerosol. Animals were sacrificed immediately, 24 or 72 h after exposure. The bronchoalveolar lavage fluid from rat lungs was recovered. Macrophages filled with SiC NPs were observed in the rat lungs. The greatest load of SiC and macrophages filled with SiC were observed on the rat lungs sacrificed 24 h after acute exposure. A limited acute inflammatory response was found up to 24 h after exposure characterized by a lactate dehydrogenase and total protein increase or presence of inflammatory cells in pulmonary lavage. For this study a WBE model has been developed, it allows the simultaneous exposure of six rats to a nanoaerosol and six rats to clean-filtered air. The nanoaerosol was generated using a rotating brush system (RBG-1000) and analyzed with an electrical low pressure impactor in real time.

  18. Human bocavirus and acute wheezing in children

    NARCIS (Netherlands)

    Allander, Tobias; Jartti, Tuomas; Gupta, Shawon; Niesters, Hubert G M; Lehtinen, Pasi; Osterback, Riikka; Vuorinen, Tytti; Waris, Matti; Bjerkner, Annelie; Tiveljung-Lindell, Annika; van den Hoogen, Bernadette G; Hyypiä, Timo; Ruuskanen, Olli

    2007-01-01

    BACKGROUND: Human bocavirus is a newly discovered parvovirus. It has been detected primarily in children with acute lower respiratory tract infection, but its occurrence, clinical profile, and role as a causative agent of respiratory tract disease are not clear. METHODS: We investigated the presence

  19. Assessment of Human Exposure to ENMs.

    Science.gov (United States)

    Jiménez, Araceli Sánchez; van Tongeren, Martie

    2017-01-01

    Human exposure assessment of engineered nanomaterials (ENMs) is hampered, among other factors, by the difficulty to differentiate ENM from other nanomaterials (incidental to processes or naturally occurring) and the lack of a single metric that can be used for health risk assessment. It is important that the exposure assessment is carried out throughout the entire life-cycle as releases can occur at the different stages of the product life-cycle, from the synthesis, manufacture of the nano-enable product (occupational exposure) to the professional and consumer use of nano-enabled product (consumer exposure) and at the end of life.Occupational exposure surveys should follow a tiered approach, increasing in complexity in terms of instruments used and sampling strategy applied with higher tiers in order tailor the exposure assessment to the specific materials used and workplace exposure scenarios and to reduce uncertainty in assessment of exposure. Assessment of consumer exposure and of releases from end-of-life processes currently relies on release testing of nano-enabled products in laboratory settings.

  20. Atmospheric Ionizing Radiation and Human Exposure

    Science.gov (United States)

    Wilson, John W.; Mertens, Christopher J.; Goldhagen, Paul; Friedberg, W.; DeAngelis, G.; Clem, J. M.; Copeland, K.; Bidasaria, H. B.

    2005-01-01

    Atmospheric ionizing radiation is of interest, apart from its main concern of aircraft exposures, because it is a principal source of human exposure to radiations with high linear energy transfer (LET). The ionizing radiations of the lower atmosphere near the Earth s surface tend to be dominated by the terrestrial radioisotopes. especially along the coastal plain and interior low lands, and have only minor contributions from neutrons (11 percent). The world average is substantially larger but the high altitude cities especially have substantial contributions from neutrons (25 to 45 percent). Understanding the world distribution of neutron exposures requires an improved understanding of the latitudinal, longitudinal, altitude and spectral distribution that depends on local terrain and time. These issues are being investigated in a combined experimental and theoretical program. This paper will give an overview of human exposures and describe the development of improved environmental models.

  1. Variation in calculated human exposure. Comparison of calculations with seven European human exposure models

    NARCIS (Netherlands)

    Swartjes F; ECO

    2003-01-01

    Twenty scenarios, differing with respect to land use, soil type and contaminant, formed the basis for calculating human exposure from soil contaminants with the use of models contributed by seven European countries (one model per country). Here, the human exposures to children and children

  2. Acute normobaric hypoxia reduces body temperature in humans.

    Science.gov (United States)

    DiPasquale, Dana M; Kolkhorst, Fred W; Buono, Michael J

    2015-03-01

    Anapyrexia is the regulated decrease in body temperature during acute exposure to hypoxia. This study examined resting rectal temperature (Trec) in adult humans during acute normobaric hypoxia (NH). Ten subjects breathed air consisting of 21% (NN), 14% (NH14), and 12% oxygen (NH12) for 30 min each in thermoneutral conditions while Trec and blood oxygen saturation (Spo2) were measured. Linear regression indicated that Spo2 was progressively lower in NH14 (p=0.0001) and NH12 (p=0.0001) compared to NN, and that Spo2 in NH14 was different than NH12 (p=0.00001). Trec was progressively lower during NH14 (p=0.014) and in NH12 (p=0.0001) compared to NN. The difference in Trec between NH14 and NH12 was also significant (p=0.0287). Spo2 was a significant predictor of Trec such that for every 1% decrease in Spo2, Trec decreased by 0.15°C (p=0.0001). The present study confirmed that, similar to many other species, human adults respond to acute hypoxia exposure by lowering rectal temperature.

  3. 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

  4. Acute radiation syndrome caused by accidental radiation exposure - therapeutic principles

    Directory of Open Access Journals (Sweden)

    Dörr Harald

    2011-11-01

    Full Text Available Abstract Fortunately radiation accidents are infrequent occurrences, but since they have the potential of large scale events like the nuclear accidents of Chernobyl and Fukushima, preparatory planning of the medical management of radiation accident victims is very important. Radiation accidents can result in different types of radiation exposure for which the diagnostic and therapeutic measures, as well as the outcomes, differ. The clinical course of acute radiation syndrome depends on the absorbed radiation dose and its distribution. Multi-organ-involvement and multi-organ-failure need be taken into account. The most vulnerable organ system to radiation exposure is the hematopoietic system. In addition to hematopoietic syndrome, radiation induced damage to the skin plays an important role in diagnostics and the treatment of radiation accident victims. The most important therapeutic principles with special reference to hematopoietic syndrome and cutaneous radiation syndrome are reviewed.

  5. Effects of asphalt fume condensate exposure on acute pulmonary responses

    Energy Technology Data Exchange (ETDEWEB)

    Ma, J.Y.C.; Barger, M.W.; Castranova, V. [Health Effects Lab. Div., National Inst. for Occupational Safety and Health, Morgantown, WV (United States); Kriech, A.J. [Heritage Research Group, Indianapolis, IN (United States)

    2000-10-01

    The present study was carried out to characterize the effects of in vitro exposure to paving asphalt fume condensate (AFC) on alveolar macrophage (AM) functions and to monitor acute pulmonary responses to in vivo AFC exposure in rats. Methods: For in vitro studies, rat primary AM cultures were incubated with various concentrations of AFC for 24 h at 37 C. AM-conditioned medium was collected and assayed for lactate dehydrogenase (LDH) as a marker of cytotoxicity. Tumor necrosis factor-{alpha} (TNF-{alpha}) and interleukin-1 (IL-1) production were assayed in AM-conditioned medium to monitor AM function. The effect of AFC on chemiluminescence (CL) generated by resting AM or AM in response to zymosan or PMA stimulation was also determined as a marker of AM activity. For in vivo studies, rats received either (1) a single intratracheal (IT) instillation of saline, or 0.1 mg or 0.5 mg AFC and were killed 1 or 3 days later; or (2) IT instillation of saline, or 0.1, 0.5, or 2 mg AFC for three consecutive days and were killed the following day. Differential counts of cells harvested by bronchoalveolar lavage were measured to monitor inflammation. Acellular LDH and protein content in the first lavage fluid were measured to monitor damage. CL generation, TNF-{alpha} and IL-1 production by AM were assayed to monitor AM function. Results: In vitro AFC exposure at <200 {mu}g/ml did not induce cytotoxicity, oxidant generation, or IL-1 production by AM, but it did cause a small but significant increase in TNF-{alpha} release from AM. In vitro exposure of AM to AFC resulted in a significant decline of CL in response to zymosan or PMA stimulation. The in vivo studies showed that AFC exposure did not induce significant neutrophil infiltration or alter LDH or protein content in acellular lavage samples. Macrophages obtained from AFC-exposed rats did not show significant differences in oxidant production or cytokine secretion at rest or in response to LPS in comparison with control

  6. Responses of Hyalella azteca to acute and chronic microplastic exposures.

    Science.gov (United States)

    Au, Sarah Y; Bruce, Terri F; Bridges, William C; Klaine, Stephen J

    2015-11-01

    Limited information is available on the presence of microplastics in freshwater systems, and even less is known about the toxicological implications of the exposure of aquatic organisms to plastic particles. The present study was conducted to evaluate the effects of microplastic ingestion on the freshwater amphipod, Hyalella azteca. Hyalella azteca was exposed to fluorescent polyethylene microplastic particles and polypropylene microplastic fibers in individual 250-mL chambers to determine 10-d mortality. In acute bioassays, polypropylene microplastic fibers were significantly more toxic than polyethylene microplastic particles; 10-d lethal concentration 50% values for polyethylene microplastic particles and polypropylene microplastic fibers were 4.64 × 10(4) microplastics/mL and 71.43 microplastics/mL, respectively. A 42-d chronic bioassay using polyethylene microplastic particles was conducted to quantify effects on reproduction, growth, and egestion. Chronic exposure to polyethylene microplastic particles significantly decreased growth and reproduction at the low and intermediate exposure concentrations. During acute exposures to polyethylene microplastic particles, the egestion times did not significantly differ from the egestion of normal food materials in the control; egestion times for polypropylene microplastic fibers were significantly slower than the egestion of food materials in the control. Amphipods exposed to polypropylene microplastic fibers also had significantly less growth. The greater toxicity of microplastic fibers than microplastic particles corresponded with longer residence times for the fibers in the gut. The difference in residence time might have affected the ability to process food, resulting in an energetic effect reflected in sublethal endpoints.

  7. Increased oxidative stress following acute and chronic high altitude exposure.

    Science.gov (United States)

    Jefferson, J Ashley; Simoni, Jan; Escudero, Elizabeth; Hurtado, Maria-Elena; Swenson, Erik R; Wesson, Donald E; Schreiner, George F; Schoene, Robert B; Johnson, Richard J; Hurtado, Abdias

    2004-01-01

    The generation of reactive oxygen species is typically associated with hyperoxia and ischemia reperfusion. Recent evidence has suggested that increased oxidative stress may occur with hypoxia. We hypothesized that oxidative stress would be increased in subjects exposed to high altitude hypoxia. We studied 28 control subjects living in Lima, Peru (sea level), at baseline and following 48 h exposure to high altitude (4300 m). To assess the effects of chronic altitude exposure, we studied 25 adult males resident in Cerro de Pasco, Peru (altitude 4300 m). We also studied 27 subjects living in Cerro de Pasco who develop excessive erythrocytosis (hematocrit > 65%) and chronic mountain sickness. Acute high altitude exposure led to increased urinary F(2)-isoprostane, 8-iso PGF(2 alpha) (1.31 +/- 0.8 microg/g creatinine versus 2.15 +/- 1.1, p = 0.001) and plasma total glutathione (1.29 +/- 0.10 micromol versus 1.37 +/- 0.09, p = 0.002), with a trend to increased plasma thiobarbituric acid reactive substance (TBARS) (59.7 +/- 36 pmol/mg protein versus 63.8 +/- 27, p = NS). High altitude residents had significantly elevated levels of urinary 8-iso PGF(2 alpha) (1.3 +/- 0.8 microg/g creatinine versus 4.1 +/- 3.4, p = 0.007), plasma TBARS (59.7 +/- 36 pmol/mg protein versus 85 +/- 28, p = 0.008), and plasma total glutathione (1.29 +/- 0.10 micromol versus 1.55 +/- 0.19, p < 0.0001) compared to sea level. High altitude residents with excessive erythrocytosis had higher levels of oxidative stress compared to high altitude residents with normal hematological adaptation. In conclusion, oxidative stress is increased following both acute exposure to high altitude without exercise and with chronic residence at high altitude.

  8. Evidence Report: Risk of Acute and Late Central Nervous System Effects from Radiation Exposure

    Science.gov (United States)

    Nelson, Gregory A.; Simonsen, Lisa; Huff, Janice L.

    2016-01-01

    Possible acute and late risks to the central nervous system (CNS) from galactic cosmic rays (GCR) and solar particle events (SPE) are concerns for human exploration of space. Acute CNS risks may include: altered cognitive function, reduced motor function, and behavioral changes, all of which may affect performance and human health. Late CNS risks may include neurological disorders such as Alzheimer's disease (AD), dementia and premature aging. Although detrimental CNS changes are observed in humans treated with high-dose radiation (e.g., gamma rays and 9 protons) for cancer and are supported by experimental evidence showing neurocognitive and behavioral effects in animal models, the significance of these results on the morbidity to astronauts has not been elucidated. There is a lack of human epidemiology data on which to base CNS risk estimates; therefore, risk projection based on scaling to human data, as done for cancer risk, is not possible for CNS risks. Research specific to the spaceflight environment using animal and cell models must be compiled to quantify the magnitude of CNS changes in order to estimate this risk and to establish validity of the current permissible exposure limits (PELs). In addition, the impact of radiation exposure in combination with individual sensitivity or other space flight factors, as well as assessment of the need for biological/pharmaceutical countermeasures, will be considered after further definition of CNS risk occurs.

  9. Zebrafish Models for Human Acute Organophosphorus Poisoning.

    Science.gov (United States)

    Faria, Melissa; Garcia-Reyero, Natàlia; Padrós, Francesc; Babin, Patrick J; Sebastián, David; Cachot, Jérôme; Prats, Eva; Arick Ii, Mark; Rial, Eduardo; Knoll-Gellida, Anja; Mathieu, Guilaine; Le Bihanic, Florane; Escalon, B Lynn; Zorzano, Antonio; Soares, Amadeu M V M; Raldúa, Demetrio

    2015-10-22

    Terrorist use of organophosphorus-based nerve agents and toxic industrial chemicals against civilian populations constitutes a real threat, as demonstrated by the terrorist attacks in Japan in the 1990 s or, even more recently, in the Syrian civil war. Thus, development of more effective countermeasures against acute organophosphorus poisoning is urgently needed. Here, we have generated and validated zebrafish models for mild, moderate and severe acute organophosphorus poisoning by exposing zebrafish larvae to different concentrations of the prototypic organophosphorus compound chlorpyrifos-oxon. Our results show that zebrafish models mimic most of the pathophysiological mechanisms behind this toxidrome in humans, including acetylcholinesterase inhibition, N-methyl-D-aspartate receptor activation, and calcium dysregulation as well as inflammatory and immune responses. The suitability of the zebrafish larvae to in vivo high-throughput screenings of small molecule libraries makes these models a valuable tool for identifying new drugs for multifunctional drug therapy against acute organophosphorus poisoning.

  10. Inhalation exposure system used for acute and repeated-dose methyl isocyanate exposures of laboratory animals.

    Science.gov (United States)

    Adkins, B; O'Connor, R W; Dement, J M

    1987-06-01

    Laboratory animals were exposed by inhalation for 2 hr/day (acute) or 6 hr/day (four consecutive days, repeated dose) to methyl isocyanate (MIC). Exposures were conducted in stainless steel and glass inhalation exposure chambers placed in stainless steel, wire mesh cages. MIC was delivered with nitrogen via stainless steel and Teflon supply lines. Chamber concentrations ranged from 0 to 60 ppm and were monitored continuously with infrared spectrophotometers to 1 ppm and at 2-hr intervals to 20 ppb with a high performance liquid chromatograph equipped with a fluorescence detector. Other operational parameters monitored on a continuous basis included chamber temperature (20-27 degrees C), relative humidity (31-64%), static (transmural) pressure (-0.3 in.), and flow (300-500 L/min). The computer-assistance system interfaced with the inhalation exposure laboratory is described in detail, including the analytical instrumentation calibration system used throughout this investigation.

  11. Acute Exposure to Stress Improves Performance in Trace Eyeblink Conditioning and Spatial Learning Tasks in Healthy Men

    Science.gov (United States)

    Duncko, Roman; Cornwell, Brian; Cui, Lihong; Merikangas, Kathleen R.; Grillon, Christian

    2007-01-01

    The present study investigated the effects of acute stress exposure on learning performance in humans using analogs of two paradigms frequently used in animals. Healthy male participants were exposed to the cold pressor test (CPT) procedure, i.e., insertion of the dominant hand into ice water for 60 sec. Following the CPT or the control procedure,…

  12. Human biological monitoring of occupational genotoxic exposures

    DEFF Research Database (Denmark)

    Knudsen, Lisbeth E.; Sorsa, M

    1993-01-01

    ) occupational exposure limit value of styrene in ambient air. The consideration of ethical issues in human genetic monitoring is an important but often overlooked aspect. This includes the scientific and preventional relevance of performing a test on individuals, pre- and post study information of donors......Human biological monitoring is a valuable tool for exposure assessment in groups of persons occupationally exposed to genotoxic agents. If the monitoring activity covers genetic material the term genetic monitoring is used. The methods used for genetic monitoring are either substance specific, e...... for and the biomonitoring results should preferentially be linked with accurate ambient air monitoring. In persons occupationally exposed to styrene the endpoints of DNA-damage and DNA-repair in genetic monitoring are methods of choice in exposure situations above the current Danish (25 ppm) or Finnish (20 ppm...

  13. A translatable predictor of human radiation exposure.

    Directory of Open Access Journals (Sweden)

    Joseph Lucas

    Full Text Available Terrorism using radiological dirty bombs or improvised nuclear devices is recognized as a major threat to both public health and national security. In the event of a radiological or nuclear disaster, rapid and accurate biodosimetry of thousands of potentially affected individuals will be essential for effective medical management to occur. Currently, health care providers lack an accurate, high-throughput biodosimetric assay which is suitable for the triage of large numbers of radiation injury victims. Here, we describe the development of a biodosimetric assay based on the analysis of irradiated mice, ex vivo-irradiated human peripheral blood (PB and humans treated with total body irradiation (TBI. Interestingly, a gene expression profile developed via analysis of murine PB radiation response alone was inaccurate in predicting human radiation injury. In contrast, generation of a gene expression profile which incorporated data from ex vivo irradiated human PB and human TBI patients yielded an 18-gene radiation classifier which was highly accurate at predicting human radiation status and discriminating medically relevant radiation dose levels in human samples. Although the patient population was relatively small, the accuracy of this classifier in discriminating radiation dose levels in human TBI patients was not substantially confounded by gender, diagnosis or prior exposure to chemotherapy. We have further incorporated genes from this human radiation signature into a rapid and high-throughput chemical ligation-dependent probe amplification assay (CLPA which was able to discriminate radiation dose levels in a pilot study of ex vivo irradiated human blood and samples from human TBI patients. Our results illustrate the potential for translation of a human genetic signature for the diagnosis of human radiation exposure and suggest the basis for further testing of CLPA as a candidate biodosimetric assay.

  14. Depression of contraction and the calcium transient in single cardiomyocytes with acute ethanol exposure

    Energy Technology Data Exchange (ETDEWEB)

    Rozanski, D.J.; Delaville, F.J.; Thomas, A.P. (Thomas Jefferson Univ., Philadelphia, PA (United States))

    1992-01-01

    The mechanism by which acute ethanol (ET) exposure causes reversible myocardial dysfunction is unknown. The purpose of this study was to examine the effects of ET exposure on contraction and cytosolic free Ca[sup 2+] ([Ca[sup 2+

  15. Self-reported acute health symptoms and exposure to companion animals

    Science.gov (United States)

    Background: In order to understand the etiological burden of disease associated with acute health symptoms (e.g. gastrointestinal [GI], respiratory, dermatological), it is important to understand how common exposures influence these symptoms. Exposures to familiar and unfamiliar ...

  16. ASSESSMENT OF HUMAN EXPOSURE TO TOLUENE DIISOCYANATE

    Directory of Open Access Journals (Sweden)

    OLIVIA ANCA RUSU

    2011-03-01

    Full Text Available Assessment of human exposure to toluene diisocyanate. Toluene diisocyanate (TDI, an aromatic compound, may be dangerous for human health. Diisocyanates have wide industrial use in the fabrication of flexible and rigid foams, fibers, elastomers, and coatings such as paints and varnishes. Isocyanates are known skin and respiratory sensitizers, and proper engineering controls should be in place to prevent exposure to isocyanate liquid and vapor; exposure to TDI vapors is well documented to increase asthma risk. The study focused on the exposure of workers and nearby populations to toluene diisocyanate in a Polyurethane Foam Factory located in Baia Mare, Romania. Workplace air measurements were performed in different departments of the plant, after sampling either in fixed points or as personal monitoring. Sampling in four different locations of Baia Mare town was carried out, - during and after the foaming process. TDI sampling was performed on silica cartridge followed by GC-MS analysis. TDI concentration at workplace was lower than 0,035 mg/m³, which represents the permissible exposure limit, while in the city the TDI concentration had shown values below 0,20 μg/m³. Health assessment of a group of 49 workers was based on questionnaire interview, determination of TDI antibodies and lung function tests. Data collected until this stage do not show any negative effects of TDI on the employees health. Since this plant had only recently begun operating, continuous workplace and ambient air TDI monitoring, along with workers health surveillance, is deemed necessary.

  17. Infant acute leukemia and maternal exposures during pregnancy.

    Science.gov (United States)

    Pombo-de-Oliveira, Maria S; Koifman, Sergio

    2006-12-01

    Infant acute leukemia (IAL) has a unique profile characterized by the high incidence of translocations involving the MLL gene located at the 11q23 region. To test the potential role of intrauterine and perinatal factors linked to the risk of IAL development, a hospital-based case-control study was conducted in different cities of Brazil. A total of 202 children (ages 0-21 months) with newly diagnosed IAL was enrolled (1999-2005), and 440 age-matched controls were selected from the same hospitals wherein IAL cases were treated. A statistically significant association between maternal use of hormones during pregnancy and IAL was observed [odds ratio (OR), 8.76; 95% confidence interval (95% CI), 2.85-26.93] in a multivariable analysis. The association of certain exposures during pregnancy (hormones, dipyrone, metronidazole, and misoprostol) and MLL gene rearrangements was tested using a case-case approach. Despite the lack of statistical significance, the magnitude of the OR for maternal exposure to dipyrone (OR, 1.45; 95% CI, 0.75-2.86), metronidazole (OR, 1.72; 95% CI, 0.64-4.58), quinolones (OR, 2.25; 95% CI, 0.70-25.70), and hormones (OR, 1.88; 95% CI, 0.50-7.01) may suggest the occurrence of interactions between such maternal exposures during pregnancy and MLL rearrangements, yielding into IAL development. The strong and statistically significant association between IAL and estrogen exposure during pregnancy observed in this study deserves further investigation to investigate its role in intrauterine leukemogenesis.

  18. Pesticides: an update of human exposure and toxicity.

    Science.gov (United States)

    Mostafalou, Sara; Abdollahi, Mohammad

    2017-02-01

    Pesticides are a family of compounds which have brought many benefits to mankind in the agricultural, industrial, and health areas, but their toxicities in both humans and animals have always been a concern. Regardless of acute poisonings which are common for some classes of pesticides like organophosphoruses, the association of chronic and sub-lethal exposure to pesticides with a prevalence of some persistent diseases is going to be a phenomenon to which global attention has been attracted. In this review, incidence of various malignant, neurodegenerative, respiratory, reproductive, developmental, and metabolic diseases in relation to different routes of human exposure to pesticides such as occupational, environmental, residential, parental, maternal, and paternal has been systematically criticized in different categories of pesticide toxicities like carcinogenicity, neurotoxicity, pulmonotoxicity, reproductive toxicity, developmental toxicity, and metabolic toxicity. A huge body of evidence exists on the possible role of pesticide exposures in the elevated incidence of human diseases such as cancers, Alzheimer, Parkinson, amyotrophic lateral sclerosis, asthma, bronchitis, infertility, birth defects, attention deficit hyperactivity disorder, autism, diabetes, and obesity. Most of the disorders are induced by insecticides and herbicides most notably organophosphorus, organochlorines, phenoxyacetic acids, and triazine compounds.

  19. Physiological Determinants of Human Acute Hypoxia Tolerance

    Science.gov (United States)

    2013-11-01

    approved in advance by the Civil Aerospace Medical Institute (CAMI) Institutional Review Board for the Protection of Human Subjects, which conforms to the...45.72 ± 10.40 (25.30 – 70.43) Resting VO2 (ml/kg/min) 3.93 ± 0.90 (2.76 – 6.35) DLO2 (ml/mm Hg/min) 40.65 ± 7.72 (25.83 – 59.00) Total Hgb...less SpO2 fell during the 5-min exposure. Max velocity of MCA flow gradually increased after the start of the hypoxia exposure in all subjects and

  20. Human models of acute lung injury

    Directory of Open Access Journals (Sweden)

    Alastair G. Proudfoot

    2011-03-01

    Full Text Available Acute lung injury (ALI is a syndrome that is characterised by acute inflammation and tissue injury that affects normal gas exchange in the lungs. Hallmarks of ALI include dysfunction of the alveolar-capillary membrane resulting in increased vascular permeability, an influx of inflammatory cells into the lung and a local pro-coagulant state. Patients with ALI present with severe hypoxaemia and radiological evidence of bilateral pulmonary oedema. The syndrome has a mortality rate of approximately 35% and usually requires invasive mechanical ventilation. ALI can follow direct pulmonary insults, such as pneumonia, or occur indirectly as a result of blood-borne insults, commonly severe bacterial sepsis. Although animal models of ALI have been developed, none of them fully recapitulate the human disease. The differences between the human syndrome and the phenotype observed in animal models might, in part, explain why interventions that are successful in models have failed to translate into novel therapies. Improved animal models and the development of human in vivo and ex vivo models are therefore required. In this article, we consider the clinical features of ALI, discuss the limitations of current animal models and highlight how emerging human models of ALI might help to answer outstanding questions about this syndrome.

  1. Acute acid exposure increases rabbit esophageal cell proliferation.

    Science.gov (United States)

    Carpizo, D R; Reaka, A J; Glaws, W R; Pooley, N; Schmidt, L; Halline, A G; Goldstein, J L; Layden, T J

    1998-02-01

    In the present study we examined whether an acute infusion of HCl into the esophagus of rabbits would cause an increase in esophageal cellular proliferation independent of morphologic evidence of cell injury. To examine this question, the distal two thirds of the rabbit esophagus was infused for 1 hour with either 40 mmol/L HCl or NSS (control), and cellular proliferation was studied 24 and 48 hours later by using bromodeoxyuridine (BrDu) to label the nuclei of dividing cells and ornithine decarboxylase (ODC) enzyme activity as a biochemical index of cell division. Although there was no gross or microscopic evidence of cell necrosis or mucosal inflammation 24 hours after H+ infusion, BrDu labeling of basal cell nuclei was significantly greater 24 hours after H+ infusion (31%+/-6%) as compared with that in control animals infused with NSS (15%+/-4%). This increase in labeling index was paralleled by a threefold greater ODC enzyme activity at 24 hours with H+ infusion. Rete pegs were infrequent in control tissues (4+/-4 rete pegs per 100 microm of esophageal length) or in animals examined 24 hours after acid exposure (4+/-2 rete pegs per 100 microm). However, rete pegs were very prominent 48 hours after acid infusion (22+/-6 rete pegs per 100 microm). A short exposure to acid can cause a significant increase in mucosal proliferation independent of injury, suggesting that esophageal cell acidification either directly or indirectly acts as a tissue mitogen.

  2. Sildenafil does not Improve Exercise Capacity under Acute Hypoxia Exposure.

    Science.gov (United States)

    Toro-Salinas, A H; Fort, N; Torrella, J R; Pagès, T; Javierre, C; Viscor, G

    2016-09-01

    The increase in pulmonary arterial pressure (PAP) due to hypoxic pulmonary vasoconstriction (HPV) could be a limiting factor for physical performance during hypoxic exposure. Sildenafil has been shown to reduce PAP in situations of moderate or severe hypoxia, and consequently its role as an ergogenic aid and even a possible doping substance must be considered. We performed a double-blind crossover study to determine the effects of sildenafil on cardiovascular, respiratory and metabolic parameters in normoxia and during acute exposure to hypobaric hypoxia (4 000 m) at rest and during maximal and submaximal (60% VO2 max) exercise tests. One hour before testing started, sildenafil (100 mg) or a placebo was orally administered to 11 volunteers. In normoxic conditions, sildenafil did not affect performance. Similarly, no significant differences were found in cardiovascular and respiratory parameters in hypoxic conditions at rest or during exercise. The use of sildenafil to improve physical performance in non-acclimatized subjects is not supported by our data. © Georg Thieme Verlag KG Stuttgart · New York.

  3. Gene networks and toxicity pathways induced by acute cadmium exposure in adult largemouth bass (Micropterus salmoides)

    Energy Technology Data Exchange (ETDEWEB)

    Mehinto, Alvine C., E-mail: alvinam@sccwrp.org [Southern California Coastal Water Research Project, Costa Mesa, CA 92626 (United States); Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Prucha, Melinda S. [Department of Human Genetics, Yerkes National Primate Research Center, Emory University, Atlanta, GA 30322 (United States); Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Colli-Dula, Reyna C.; Kroll, Kevin J.; Lavelle, Candice M.; Barber, David S. [Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States); Vulpe, Christopher D. [Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720 (United States); Denslow, Nancy D. [Department of Physiological Sciences and Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL 32611 (United States)

    2014-07-01

    Highlights: • Low-level acute cadmium exposure elicited tissue-specific gene expression changes. • Molecular initiating events included oxidative stress and disruption of DNA repair. • Metallothionein, a marker of metal exposure, was not significantly affected. • We report effects of cadmium on cholesterol metabolism and steroid synthesis. • Diabetic complications and impaired reproduction are potential adverse outcomes. - Abstract: Cadmium is a heavy metal that can accumulate to toxic levels in the environment leading to detrimental effects in animals and humans including kidney, liver and lung injuries. Using a transcriptomics approach, genes and cellular pathways affected by a low dose of cadmium were investigated. Adult largemouth bass were intraperitoneally injected with 20 μg/kg of cadmium chloride (mean exposure level – 2.6 μg of cadmium per fish) and microarray analyses were conducted in the liver and testis 48 h after injection. Transcriptomic profiles identified in response to cadmium exposure were tissue-specific with the most differential expression changes found in the liver tissues, which also contained much higher levels of cadmium than the testis. Acute exposure to a low dose of cadmium induced oxidative stress response and oxidative damage pathways in the liver. The mRNA levels of antioxidants such as catalase increased and numerous transcripts related to DNA damage and DNA repair were significantly altered. Hepatic mRNA levels of metallothionein, a molecular marker of metal exposure, did not increase significantly after 48 h exposure. Carbohydrate metabolic pathways were also disrupted with hepatic transcripts such as UDP-glucose, pyrophosphorylase 2, and sorbitol dehydrogenase highly induced. Both tissues exhibited a disruption of steroid signaling pathways. In the testis, estrogen receptor beta and transcripts linked to cholesterol metabolism were suppressed. On the contrary, genes involved in cholesterol metabolism were highly

  4. Changes in Cardiac Autonomic Regulation after Acute Lung Exposure to Carbon Nanotubes: Implications for Occupational Exposure

    Directory of Open Access Journals (Sweden)

    Jacopo M. Legramante

    2012-01-01

    Full Text Available Carbon nanotubes (CNTs are among the most relevant engineered nanomaterials (ENMs. Given the expected rise of exposure to ENMs, there is concern that they may adversely affect health of exposed people. Aim of the study was to test the hypothesis that single wall carbon nanotubes (SWCNTs pulmonary exposure acutely affect the autonomic cardiovascular regulation in conscious rats. We studied Wistar-Kyoto rats in which a telemetry transmitter for continuous arterial pressure (AP and heart rate (HR recordings was surgically implanted. SWCNTs dispersed in phosphate buffer saline (PBS or PBS alone were randomly administered intratracheally. Immediately before, and 24 hours after each instillation a 30 min AP recording was performed. The sequence analysis was performed to evaluate the baroreflex function. In the control group, PBS instillation did not induce any significant changes. At variance the SWCNT exposure induced a significant reduction of baroreflex system (BRS (3.5±0.6 versus 2.6±0.40 msec/mmHg without significant changes in the occurrence of baroreflex sequences (7.5±0.47% versus 7.4±0.38%. Our results show that SWCNT pulmonary exposure might affect the cardiovascular autonomic regulation thus contributing to cardiac and arrhythmic events.

  5. Injury to skeletal muscle of mice following acute and sub-acute pregabalin exposure

    Science.gov (United States)

    Moshiri, Mohammad; Moallem, Seyed Adel; Attaranzadeh, Armin; Saberi, Zahra; Etemad, Leila

    2017-01-01

    Objective(s): Pregabalin (PGB) is a new antiepileptic drug that has received FDA approval for patient who suffers from central neuropathic pain, partial seizures, generalized anxiety disorder, fibromyalgia and sleep disorders. This study was undertaken to evaluate the possible adverse effects of PGB on the muscular system of mice. Materials and Methods: To evaluate the effect of PGB on skeletal muscle, the animals were exposed to a single dose of 1, 2 or 5 g /kg or daily doses of 20, 40 or 80 mg/kg for 21 days, intraperitoneally (IP). Twaenty-four hr after the last drug administration, all animals were sacrificed. The level of fast-twitch skeletal muscle troponin I and CK-MM activity were evaluated in blood as an indicator of muscle injury. Skeletal muscle pathological findings were also reported as scores ranging from 1 to 3 based on the observed lesion. Results: In the acute and sub-acute toxicity assay IP injection of PGB significantly increased the activity and levels of CK-MM and fsTnI compared to the control group. Sub-acute exposure to PGB caused damages that include muscle atrophy, infiltration of inflammatory cells and cell degeneration. Conclusion: PGB administration especially in long term care causes muscle atrophy with infiltration of inflammatory cells and cell degeneration. The fsTnI and CK-MM are reliable markers in PGB-related muscle injury. The exact mechanisms behind the muscular damage are unclear and necessitate further investigations. PMID:28392896

  6. Acute Inhalation Exposure to Titanium Ethanolate as a Possible Cause of Metal Fume Fever

    Directory of Open Access Journals (Sweden)

    M Ahmadimanesh

    2014-04-01

    Full Text Available Occupational inhalation exposure to noxious agents is not uncommon. Herein, we present a 26-year-old male student who had accidental acute inhalation exposure to a large quantity of titanium ethanolate and hydrogen chloride in chemistry lab. He was referred to the emergency department of our hospital with low-grade fever, dyspnea, headache, fatigue and myalgia. After 24 hrs of symptomatic treatment (oxygen therapy and acetaminophen, the fever was subsided and the patient discharged home in a good clinical condition. The presented symptoms could be interpreted as a form of metal fume fever. It can therefore be concluded that organo-metallic compound of titanium metal may have the potential to produce metal fume fever in human.

  7. Genome-wide gene expression profiling of acute metal exposures in male zebrafish

    Directory of Open Access Journals (Sweden)

    Christine E. Baer

    2014-12-01

    Full Text Available To capture global responses to metal poisoning and mechanistic insights into metal toxicity, gene expression changes were evaluated in whole adult male zebrafish following acute 24 h high dose exposure to three metals with known human health risks. Male adult zebrafish were exposed to nickel chloride, cobalt chloride or sodium dichromate at concentrations corresponding to their respective 96 h LC20, LC40 and LC60 (i.e. 96 h concentrations at which 20%, 40% and 60% lethality is expected, respectively. Histopathology was performed on a subset of metal-exposed zebrafish to phenotypically anchor transcriptional changes associated with each metal exposure. Here we describe in detail the contents and quality controls for the gene expression and other data associated with the study published by Hussainzada and colleagues in BMC Pharmacology and Toxicology (Hussainzada et al., 2014 with the data uploaded to Gene Expression Omnibus (accession number GSE50648.

  8. Genome-wide gene expression profiling of acute metal exposures in male zebrafish

    Science.gov (United States)

    Baer, Christine E.; Ippolito, Danielle L.; Hussainzada, Naissan; Lewis, John A.; Jackson, David A.; Stallings, Jonathan D.

    2014-01-01

    To capture global responses to metal poisoning and mechanistic insights into metal toxicity, gene expression changes were evaluated in whole adult male zebrafish following acute 24 h high dose exposure to three metals with known human health risks. Male adult zebrafish were exposed to nickel chloride, cobalt chloride or sodium dichromate at concentrations corresponding to their respective 96 h LC20, LC40 and LC60 (i.e. 96 h concentrations at which 20%, 40% and 60% lethality is expected, respectively). Histopathology was performed on a subset of metal-exposed zebrafish to phenotypically anchor transcriptional changes associated with each metal exposure. Here we describe in detail the contents and quality controls for the gene expression and other data associated with the study published by Hussainzada and colleagues in BMC Pharmacology and Toxicology (Hussainzada et al., 2014) with the data uploaded to Gene Expression Omnibus (accession number GSE50648). PMID:26484131

  9. Neurobehavioral and neurophysiological effects after acute exposure to a single peak of 200 ppm toluene in healthy volunteers.

    Science.gov (United States)

    Kobald, S Oliver; Wascher, Edmund; Blaszkewicz, Meinolf; Golka, Klaus; van Thriel, Christoph

    2015-05-01

    The solvent toluene has neurotoxic properties that are especially relevant in the working environment. Short-term exposure limits (STELs) vary from 50 ppm up to 300 ppm across countries but their acute effects remain elusive in humans. Several in vitro and in vivo studies elucidated that toluene acutely acts by perturbations of different neurotransmitter systems. More specifically visual evoked potentials (VEPs) of rats are decreased after acute toluene exposure, leading to the assumption that particularly visual attention processes might be a target of toluene in humans. Therefore a visual change detection task was applied to measure both neurobehavioral and neurophysiological effects by using electroencephalography (EEG) after a single peak exposure to 200 ppm toluene. Performance and event-related components of the EEG were examined before and after exposure in a toluene-exposed and a control group. Thirty-three young healthy volunteers participated in this study. The behavioral results of the experiment indicate that toluene impairs the rate of correct responses especially in task conditions in which an irrelevant distractor is given, while the response times did not differ between both groups. The neurophysiological findings hint toward a less efficient visual processing of behaviorally relevant stimuli and an increased distractibility by irrelevant distractors. Thus the present results are a promising starting point for further research specifically targeting visual attention after toluene exposure and the reconsideration of the presently very heterogeneous STELs.

  10. Acute Exposure to Pacific Ciguatoxin Reduces Electroencephalogram Activity and Disrupts Neurotransmitter Metabolic Pathways in Motor Cortex.

    Science.gov (United States)

    Kumar, Gajendra; Au, Ngan Pan Bennett; Lei, Elva Ngai Yu; Mak, Yim Ling; Chan, Leanne Lai Hang; Lam, Michael Hon Wah; Chan, Leo Lai; Lam, Paul Kwan Sing; Ma, Chi Him Eddie

    2016-09-10

    Ciguatera fish poisoning (CFP) is a common human food poisoning caused by consumption of ciguatoxin (CTX)-contaminated fish affecting over 50,000 people worldwide each year. CTXs are classified depending on their origin from the Pacific (P-CTXs), Indian Ocean (I-CTXs), and Caribbean (C-CTXs). P-CTX-1 is the most toxic CTX known and the major source of CFP causing an array of neurological symptoms. Neurological symptoms in some CFP patients last for several months or years; however, the underlying electrophysiological properties of acute exposure to CTXs remain unknown. Here, we used CTX purified from ciguatera fish sourced in the Pacific Ocean (P-CTX-1). Delta and theta electroencephalography (EEG) activity was reduced remarkably in 2 h and returned to normal in 6 h after a single exposure. However, second exposure to P-CTX-1 induced not only a further reduction in EEG activities but also a 2-week delay in returning to baseline EEG values. Ciguatoxicity was detected in the brain hours after the first and second exposure by mouse neuroblastoma assay. The spontaneous firing rate of single motor cortex neuron was reduced significantly measured by single-unit recording with high spatial resolution. Expression profile study of neurotransmitters using targeted profiling approach based on liquid chromatography-tandem mass spectrometry revealed an imbalance between excitatory and inhibitory neurotransmitters in the motor cortex. Our study provides a possible link between the brain oscillations and neurotransmitter release after acute exposure to P-CTX-1. Identification of EEG signatures and major metabolic pathways affected by P-CTX-1 provides new insight into potential biomarker development and therapeutic interventions.

  11. Acute marijuana effects on human risk taking.

    Science.gov (United States)

    Lane, Scott D; Cherek, Don R; Tcheremissine, Oleg V; Lieving, Lori M; Pietras, Cythia J

    2005-04-01

    Previous studies have established a relationship between marijuana use and risky behavior in natural settings. A limited number of laboratory investigations of marijuana effects on human risk taking have been conducted. The present study was designed to examine the acute effects of smoked marijuana on human risk taking, and to identify behavioral mechanisms that may be involved in drug-induced changes in the probability of risky behavior. Using a laboratory measure of risk taking designed to address acute drug effects, 10 adults were administered placebo cigarettes and three doses of active marijuana cigarettes (half placebo and half 1.77%; 1.77%; and 3.58% Delta9-THC) in a within-subject repeated-measures experimental design. The risk-taking task presented subjects with a choice between two response options operationally defined as risky and nonrisky. Data analyses examined cardiovascular and subjective effects, response rates, distribution of choices between the risky and nonrisky option, and first-order transition probabilities of trial-by-trial data. The 3.58% THC dose increased selection of the risky response option, and uniquely shifted response probabilities following both winning and losing outcomes following selection of the risky option. Acute marijuana administration thereby produced measurable changes in risky decision making under laboratory conditions. Consistent with previous risk-taking studies, shifts in trial-by-trial response probabilities at the highest dose suggested a change in sensitivity to both reinforced and losing risky outcomes. Altered sensitivity to consequences may be a mechanism in drug-induced changes in risk taking. Possible neurobiological sites of action related to THC are discussed.

  12. Bilateral optic neuritis in acute human immunodeficiency virus infection

    DEFF Research Database (Denmark)

    Larsen, M; Toft, P.B.; Bernhard, P;

    1998-01-01

    PURPOSE: To report a case of acute viral disease accompanied by bilateral optic neuritis with substantial paraclinical evidence that human immunodeficiency virus was the causative agent. METHODS: Clinical and paraclinical examination. Magnetic resonance imaging. RESULTS: Virus and antibody titers...... as well as reverse lymphocytosis were consistent with acute infection by the human immunodeficiency virus-1. CONCLUSIONS: Human immunodeficiency virus infection should be considered in the differential diagnosis of acute optic neuritis...

  13. Setting occupational exposure limits in humans: contributions from the field of experimental psychology

    NARCIS (Netherlands)

    Smeets, M.A.M.; Kroeze, J.H.A.; Dalton, P.M.

    2006-01-01

    Psychophysical methods from the field of experimental psychology are evaluated for their utility in the derivation of occupational exposure limits (OELs) for volatile chemicals based on acute sensory irritation in humans. The lateralization threshold method, which involves the localization of trigem

  14. Space Radiation and Human Exposures, A Primer.

    Science.gov (United States)

    Nelson, Gregory A

    2016-04-01

    The space radiation environment is a complex field comprised primarily of charged particles spanning energies over many orders of magnitude. The principal sources of these particles are galactic cosmic rays, the Sun and the trapped radiation belts around the earth. Superimposed on a steady influx of cosmic rays and a steady outward flux of low-energy solar wind are short-term ejections of higher energy particles from the Sun and an 11-year variation of solar luminosity that modulates cosmic ray intensity. Human health risks are estimated from models of the radiation environment for various mission scenarios, the shielding of associated vehicles and the human body itself. Transport models are used to propagate the ambient radiation fields through realistic shielding levels and materials to yield radiation field models inside spacecraft. Then, informed by radiobiological experiments and epidemiology studies, estimates are made for various outcome measures associated with impairments of biological processes, losses of function or mortality. Cancer-associated risks have been formulated in a probabilistic model while management of non-cancer risks are based on permissible exposure limits. This article focuses on the various components of the space radiation environment and the human exposures that it creates.

  15. A QUANTITATIVE COMPARISON OF THE EFFECTS OF ACUTE INHALED TOLUENE IN HUMAN RATS

    Science.gov (United States)

    The effects of acute exposure to toluene have been explored more thoroughly than other hydrocarbon solvents. These effects have been experimentally studied in humans and other species, e.g., rats, as well as in a number of in vitro preparations. The existence ofdosimetric and eff...

  16. [Human exposure to trihalomethanes in drinking water].

    Science.gov (United States)

    Tominaga, M Y; Midio, A F

    1999-08-01

    Halogenated hydrocarbon compounds, some of them recognized as carcinogenic to different animal species can be found in drinking water. Chloroform, bromodichloromethane, dibromochloromethane and bromoform are the most important trihalomethanes found in potable water. They are produced in natural waters during chlorinated desinfection by the halogenation of precursors, specially humic and fulvic compounds. The review, in the MEDLINE covers the period from 1974 to 1998, presents the general aspects of the formation of trihalomethanes, sources of human exposure and their toxicological meaning for exposed organisms: toxicokinetic disposition and spectrum of toxic effects (carcinogenic, mutagenic and teratogenic).

  17. The basal kinetic parameters of glycogen synthase in human myotube cultures are not affected by chronic high insulin exposure

    DEFF Research Database (Denmark)

    Gaster, M; Schrøder, H D; Handberg, A

    2001-01-01

    There is no consensus regarding the results from in vivo and in vitro studies on the impact of chronic high insulin and/or high glucose exposure on acute insulin stimulation of glycogen synthase (GS) kinetic parameters in human skeletal muscle. The aim of this study was to evaluate the kinetic...... parameters of glycogen synthase activity in human myotube cultures at conditions of chronic high insulin combined or not with high glucose exposure, before and after a subsequent acute insulin stimulation. Acute insulin stimulation significantly increased the fractional activity (FV(0.1)) of GS, increased...

  18. Noninvasive Biomonitoring Approaches to Determine Dosimetry and Risk Following Acute Chemical Exposure: Analysis of Lead or Organophosphate Insecticide in Saliva

    Energy Technology Data Exchange (ETDEWEB)

    Timchalk, Chuck; Poet, Torka S.; Kousba, Ahmed A.; Campbell, James A.; Lin, Yuehe

    2004-04-01

    There is a need to develop approaches for assessing risk associated with acute exposures to a broad-range of chemical agents and to rapidly determine the potential implications to human health. Non-invasive biomonitoring approaches are being developed using reliable portable analytical systems to quantitate dosimetry utilizing readily obtainable body fluids, such as saliva. Saliva has been used to evaluate a broad range of biomarkers, drugs, and environmental contaminants including heavy metals and pesticides. To advance the application of non-invasive biomonitoring a microfluidic/ electrochemical device has also been developed for the analysis of lead (Pb), using square wave anodic stripping voltammetry. The system demonstrates a linear response over a broad concentration range (1 2000 ppb) and is capable of quantitating saliva Pb in rats orally administered acute doses of Pb-acetate. Appropriate pharmacokinetic analyses have been used to quantitate systemic dosimetry based on determination of saliva Pb concentrations. In addition, saliva has recently been used to quantitate dosimetry following exposure to the organophosphate insecticide chlorpyrifos in a rodent model system by measuring the major metabolite, trichloropyridinol, and saliva cholinesterase inhibition following acute exposures. These results suggest that technology developed for non-invasive biomonitoring can provide a sensitive, and portable analytical tool capable of assessing exposure and risk in real-time. By coupling these non-invasive technologies with pharmacokinetic modeling it is feasible to rapidly quantitate acute exposure to a broad range of chemical agents. In summary, it is envisioned that once fully developed, these monitoring and modeling approaches will be useful for accessing acute exposure and health risk.

  19. Injury to skeletal muscle of mice following acute and sub-acute pregabalin exposure

    Directory of Open Access Journals (Sweden)

    Mohammad Moshiri

    2017-03-01

    Full Text Available Objective(s: Pregabalin (PGB is a new antiepileptic drug that has received FDA approval for patient who suffers from central neuropathic pain, partial seizures, generalized anxiety disorder, fibromyalgia and sleep disorders. This study was undertaken to evaluate the possible adverse effects of PGB on the muscular system of mice. Materials and Methods: To evaluate the effect of PGB on skeletal muscle, the animals were exposed to a single dose of 1, 2 or 5 g /kg or daily doses of 20, 40 or 80 mg/kg for 21 days, intraperitoneally (IP. Twaenty-four hr after the last drug administration, all animals were sacrificed. The level of fast-twitch skeletal muscle troponin I and CK-MM activity were evaluated in blood as an indicator of muscle injury. Skeletal muscle pathological findings were also reported as scores ranging from 1 to 3 based on the observed lesion. Results: In the acute and sub-acute toxicity assay IP injection of PGB significantly increased the activity and levels of CK-MM and fsTnI compared to the control group. Sub-acute exposure to PGB caused damages that include muscle atrophy, infiltration of inflammatory cells and cell degeneration. Conclusion: PGB administration especially in long term care causes muscle atrophy with infiltration of inflammatory cells and cell degeneration. The fsTnI and CK-MM are reliable markers in PGB-related muscle injury. The exact mechanisms behind the muscular damage are unclear and necessitate further investigations.

  20. Acute Rejection after Human Renal Transplantation

    Directory of Open Access Journals (Sweden)

    Ana Roussoulières

    2007-01-01

    Full Text Available Genes involved in acute rejection (AR after organ transplantation remain to be further elucidated. In a previous work we have demonstrated the under-expression of VE-Cadherin by endothelial cells (EC in AR following murine and human heart transplantation. Serial sections from 15 human kidney Banff-graded transplant biopsies were examined for the presence of VE-Cadherin and CD34 staining by immunohistochemistry (no AR (n=5, AR grade IA (n=5, or AR grade IIA (n=5. Quantification of peritubular EC staining were evaluated and results were expressed by the percentage of stained cells per surface analysed. There was no difference in CD34 staining between the 3 groups. VE-Cadherin expression was significantly reduced in AR Grade IIA when compared to no AR (P=.01 and to AR grade IA (P=.02. This study demonstrates a reduced VE-Cadherin expression by EC in AR after renal transplantation. The down-regulation of VE-Cadherin may strongly participate in human AR.

  1. Acute exposure to apolipoprotein A1 inhibits macrophage chemotaxis in vitro and monocyte recruitment in vivo

    Science.gov (United States)

    Iqbal, Asif J; Barrett, Tessa J; Taylor, Lewis; McNeill, Eileen; Manmadhan, Arun; Recio, Carlota; Carmineri, Alfredo; Brodermann, Maximillian H; White, Gemma E; Cooper, Dianne; DiDonato, Joseph A; Zamanian-Daryoush, Maryam; Hazen, Stanley L; Channon, Keith M

    2016-01-01

    Apolipoprotein A1 (apoA1) is the major protein component of high-density lipoprotein (HDL) and has well documented anti-inflammatory properties. To better understand the cellular and molecular basis of the anti-inflammatory actions of apoA1, we explored the effect of acute human apoA1 exposure on the migratory capacity of monocyte-derived cells in vitro and in vivo. Acute (20–60 min) apoA1 treatment induced a substantial (50–90%) reduction in macrophage chemotaxis to a range of chemoattractants. This acute treatment was anti-inflammatory in vivo as shown by pre-treatment of monocytes prior to adoptive transfer into an on-going murine peritonitis model. We find that apoA1 rapidly disrupts membrane lipid rafts, and as a consequence, dampens the PI3K/Akt signalling pathway that coordinates reorganization of the actin cytoskeleton and cell migration. Our data strengthen the evidence base for therapeutic apoA1 infusions in situations where reduced monocyte recruitment to sites of inflammation could have beneficial outcomes. DOI: http://dx.doi.org/10.7554/eLife.15190.001 PMID:27572261

  2. Acute and chronic effects of erythromycin exposure on oxidative stress and genotoxicity parameters of Oncorhynchus mykiss

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, S., E-mail: up201208875@fc.up.pt [Departamento de Biologia da Faculdade de Ciências da Universidade do Porto (FCUP), Rua do Campo Alegre s/n, 4169–007 Porto (Portugal); Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Rua dos Bragas 289, 4050–123 Porto (Portugal); Antunes, S.C. [Departamento de Biologia da Faculdade de Ciências da Universidade do Porto (FCUP), Rua do Campo Alegre s/n, 4169–007 Porto (Portugal); Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Rua dos Bragas 289, 4050–123 Porto (Portugal); Correia, A.T. [Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Rua dos Bragas 289, 4050–123 Porto (Portugal); Faculdade de Ciências da Saúde da Universidade Fernando Pessoa (FCS-UFP), Rua Carlos da Maia, 296, 4200–150, Porto (Portugal); Nunes, B. [Centro de Estudos do Ambiente e do Mar (CESAM), Campus de Santiago, Universidade de Aveiro, 3810–193 Aveiro (Portugal); Departamento de Biologia, Universidade de Aveiro, Campus de Santiago, 3810–193 Aveiro (Portugal)

    2016-03-01

    Erythromycin (ERY) is a macrolide antibiotic used in human and veterinary medicine, and has been detected in various aquatic compartments. Recent studies have indicated that this compound can exert biological activity on non-target organisms environmentally exposed. The present study aimed to assess the toxic effects of ERY in Oncorhynchus mykiss after acute and chronic exposures. The here adopted strategy involved exposure to three levels of ERY, the first being similar to concentrations reported to occur in the wild, thus ecologically relevant. Catalase (CAT), total glutathione peroxidase (GPx), glutathione reductase (GRed) activities and lipid peroxidation (TBARS levels) were quantified as oxidative stress biomarkers in gills and liver. Genotoxic endpoints, reflecting different types of genetic damage in blood cells, were also determined, by performing analysis of genetic damage (determination of the genetic damage index, GDI, measured by comet assay) and of erythrocytic nuclear abnormalities (ENAs). The results suggest the occurrence of a mild, but significant, oxidative stress scenario in gills. For acutely exposed organisms, significant alterations were observed in CAT and GRed activities, and also in TBARS levels, which however are modifications with uncertain biological interpretation, despite indicating involvement of an oxidative effect and response. After chronic exposure, a significant decrease of CAT activity, increase of GPx activity and TBARS levels in gills was noticed. In liver, significant decrease in TBARS levels were observed in both exposures. Comet and ENAs assays indicated significant increases on genotoxic damage of O. mykiss, after erythromycin exposures. This set of data (acute and chronic) suggests that erythromycin has the potential to induce DNA strand breaks in blood cells, and demonstrate the induction of chromosome breakage and/or segregational abnormalities. Overall results indicate that both DNA damaging effects induced by

  3. ESTIMATED RATE OF FATAL AUTOMOBILE ACCIDENTS ATTRIBUTABLE TO ACUTE SOLVENT EXPOSURE AT LOW INHALED CONCENTRATIONS

    Science.gov (United States)

    Acute solvent exposures may contribute to automobile accidents because they increase reaction time and decrease attention, in addition to impairing other behaviors. These effects resemble those of ethanol consumption, both with respect to behavioral effects and neurological mecha...

  4. Studies of adaptive response and mutation induction in MCF-10A cells following exposure to chronic or acute ionizing radiation.

    Science.gov (United States)

    Manesh, Sara Shakeri; Sangsuwan, Traimate; Wojcik, Andrzej; Haghdoost, Siamak

    2015-10-01

    A phenomenon in which exposure to a low adapting dose of radiation makes cells more resistant to the effects of a subsequent high dose exposure is termed radio-adaptive response. Adaptive response could hypothetically reduce the risk of late adverse effects of chronic or acute radiation exposures in humans. Understanding the underlying mechanisms of such responses is of relevance for radiation protection as well as for the clinical applications of radiation in medicine. However, due to the variability of responses depending on the model system and radiation condition, there is a need to further study under what conditions adaptive response can be induced. In this study, we analyzed if there is a dose rate dependence for the adapting dose, assuming that the adapting dose induces DNA response/repair pathways that are dose rate dependent. MCF-10A cells were exposed to a 50mGy adapting dose administered acutely (0.40Gy/min) or chronically (1.4mGy/h or 4.1mGy/h) and then irradiated by high acute challenging doses. The endpoints of study include clonogenic cell survival and mutation frequency at X-linked hprt locus. In another series of experiment, cells were exposed to 100mGy and 1Gy at different dose rates (acutely and chronically) and then the mutation frequencies were studied. Adaptive response was absent at the level of clonogenic survival. The mutation frequencies were significantly decreased in the cells pre-exposed to 50mGy at 1.4mGy/h followed by 1Gy acute exposure as challenging dose. Importantly, at single dose exposures (1 Gy or 100mGy), no differences at the level of mutation were found comparing different dose rates. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Long term exposure to ambient air pollution and incidence of acute coronary events

    DEFF Research Database (Denmark)

    Cesaroni, Giulia; Forastiere, Francesco; Stafoggia, Massimo

    2014-01-01

    To study the effect of long term exposure to airborne pollutants on the incidence of acute coronary events in 11 cohorts participating in the European Study of Cohorts for Air Pollution Effects (ESCAPE).......To study the effect of long term exposure to airborne pollutants on the incidence of acute coronary events in 11 cohorts participating in the European Study of Cohorts for Air Pollution Effects (ESCAPE)....

  6. Sensory and Physiological Effects on Humans of Combined Exposures to Air Temperatures and Volatile Organic Compounds

    DEFF Research Database (Denmark)

    Mølhave, Lars; Liu, Zunyong; Jørgensen, Anne Hempel

    1993-01-01

    Ten healthy humans were exposed to combinations of volatile organic compounds (VOCs) and air temperature (0 mg/m3 and 10 mg/m3 of a mixture of 22 volatile organic compounds and 18, 22 and 26° C). Previously demonstrated effects of VOCs and thermal exposures were replicated. For the first time nasal...... cross-sectional areas and nasal volumes, as measured by acoustic rhinometry, were shown to decrease with decreasing temperature and increasing VOC exposure. Temperature and pollutant exposures affected air quality, the need for more ventilation, skin humidity on the forehead, sweating, acute sensory...

  7. Setting safe acute exposure limits for halon replacement chemicals using physiologically based pharmacokinetic modeling.

    Science.gov (United States)

    Vinegar, A; Jepson, G W; Cisneros, M; Rubenstein, R; Brock, W J

    2000-08-01

    Most proposed replacements for Halon 1301 as a fire suppressant are halogenated hydrocarbons. The acute toxic endpoint of concern for these agents is cardiac sensitization. An approach is described that links the cardiac endpoint as assessed in dogs to a target arterial concentration in humans. Linkage was made using a physiologically based pharmacokinetic (PBPK) model. Monte Carlo simulations, which account for population variability, were used to establish safe exposure times at different exposure concentrations for Halon 1301 (bromotrifluoromethane), CF(3)I (trifluoroiodomethane), HFC-125 (pentafluoroethane), HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane), and HFC-236fa (1,1,1,3,3,3-hexafluoropropane). Application of the modeling technique described here not only makes use of the conservative cardiac sensitization endpoint, but also uses an understanding of the pharmacokinetics of the chemical agents to better establish standards for safe exposure. The combined application of cardiac sensitization data and physiologically based modeling provides a quantitative approach, which can facilitate the selection and effective use of halon replacement candidates.

  8. EFFECTS OF ARSENIC EXPOSURE IN HUMAN HEALTH

    Directory of Open Access Journals (Sweden)

    Aline Sueli de Lima Rodrigues

    2008-10-01

    Full Text Available In recent years, ingestion of inorganic arsenic from drinking water has emerged as an important public health concern. It enters drinking water supplies from natural deposits in the earth or from agricultural and industrial practices, mainly the mining. The health consequences of chronic arsenic exposure include increased risk for various forms of cancer and numerous pathologic effects, such as cutaneous effects (hyperpigmentation and hyperkeratoses, gastrointestinal effects, vascular effects, diabetes mellitus, and peripheral neuropathy. This way, this study presents through a critical revision of the literature, the more relevant current aspects on the immunological consequences, carcinogenic and resulting genetics of the human intoxication for arsenic. They were identified and analyzed 50 works published on the subject among the years of 1979 and 2008, being used as main sources LILACS-BIREME MEDLINE/Index Medicus, SciELO and PubMed. The specific Arsênio e saúde humana effects of the intoxication for arsenic about the human health are not still completely elucidated. Thus, is possible that this element affects functions still unknown, becoming important the scientificexploration on the subject.

  9. AGE-RELATED TOXICITY PATHWAY ANALYSIS IN BROWN NORWAY RAT BRAIN FOLLOWING ACUTE TOLUENE EXPOSURE

    Science.gov (United States)

    The influence of aging on susceptibility to environmental exposures is poorly understood. To investigate-the contribution of different life stages on response to toxicants, we examined the effects of an acute exposure to the volatile organic compound, toluene (0.0 or 1.0 g/kg), i...

  10. Acute stress impairs the retrieval of extinction memory in humans.

    Science.gov (United States)

    Raio, Candace M; Brignoni-Perez, Edith; Goldman, Rachel; Phelps, Elizabeth A

    2014-07-01

    Extinction training is a form of inhibitory learning that allows an organism to associate a previously aversive cue with a new, safe outcome. Extinction does not erase a fear association, but instead creates a competing association that may or may not be retrieved when a cue is subsequently encountered. Characterizing the conditions under which extinction learning is expressed is important to enhancing the treatment of anxiety disorders that rely on extinction-based exposure therapy as a primary treatment technique. The ventromedial prefrontal cortex, which plays a critical role in the expression of extinction memory, has been shown to be functionally impaired after stress exposure. Further, recent work in rodents has demonstrated that exposure to stress leads to deficits in extinction retrieval, although this has yet to be tested in humans. To explore how stress might influence extinction retrieval in humans, participants underwent a differential aversive learning paradigm, in which one image was probabilistically paired with an aversive shock while the other image denoted safety. Extinction training directly followed, at which point reinforcement was omitted. A day later, participants returned to the lab and either completed an acute stress manipulation (i.e., cold pressor), or a control task, before undergoing an extinction retrieval test. Skin conductance responses and salivary cortisol concentrations were measured throughout each session as indices of fear arousal and neuroendocrine stress response, respectively. The efficacy of our stress induction was established by observing significant increases in cortisol for the stress condition only. We examined extinction retrieval by comparing conditioned responses during the last trial of extinction (day 1) with that of the first trial of re-extinction (day 2). Groups did not differ on initial fear acquisition or extinction, however, a day later participants in the stress group (n=27) demonstrated significantly

  11. Calcium-dependent behavioural responses to acute copper exposure in Oncorhynchus mykiss

    DEFF Research Database (Denmark)

    Poulsen, S.B.; Svendsen, Jon Christian; Aarestrup, Kim;

    2014-01-01

    Using rainbow trout Oncorhynchus mykiss, the present study demonstrated that: (1) calcium (Ca) increased the range of copper (Cu) concentrations that O. mykiss avoided; (2) Ca conserved the maintenance of pre-exposure swimming activity during inescapable acute (10 min) Cu exposure. Data showed...... their spontaneous swimming speed, whereas no response was observed in O. mykiss acclimated and tested at high Ca concentration. Collectively, the data support the conclusion that in O. mykiss the behavioural responses to acute Cu exposure are Ca-dependent....

  12. Osteopontin Is Upregulated in Human and Murine Acute Schistosomiasis Mansoni

    Science.gov (United States)

    Pereira, Thiago Almeida; Syn, Wing-Kin; Amâncio, Frederico Figueiredo; Cunha, Pedro Henrique Diniz; Caporali, Julia Fonseca Morais; Trindade, Guilherme Vaz de Melo; Santos, Elisângela Trindade; Souza, Márcia Maria; Andrade, Zilton Araújo; Witek, Rafal P; Secor, William Evan; Pereira, Fausto Edmundo Lima; Lambertucci, José Roberto; Diehl, Anna Mae

    2016-01-01

    Background Symptomatic acute schistosomiasis mansoni is a systemic hypersensitivity reaction against the migrating schistosomula and mature eggs after a primary infection. The mechanisms involved in the pathogenesis of acute schistosomiasis are not fully elucidated. Osteopontin has been implicated in granulomatous reactions and in acute hepatic injury. Our aims were to evaluate if osteopontin plays a role in acute Schistosoma mansoni infection in both human and experimentally infected mice and if circulating OPN levels could be a novel biomarker of this infection. Methodology/Principal Findings Serum/plasma osteopontin levels were measured by ELISA in patients with acute (n = 28), hepatointestinal (n = 26), hepatosplenic (n = 39) schistosomiasis and in uninfected controls (n = 21). Liver osteopontin was assessed by immunohistochemistry in needle biopsies of 5 patients. Sera and hepatic osteopontin were quantified in the murine model of schistosomiasis mansoni during acute (7 and 8 weeks post infection, n = 10) and chronic (30 weeks post infection, n = 8) phase. Circulating osteopontin levels are increased in patients with acute schistosomiasis (p = 0.0001). The highest levels of OPN were observed during the peak of clinical symptoms (7–11 weeks post infection), returning to baseline level once the granulomas were modulated (>12 weeks post infection). The plasma levels in acute schistosomiasis were even higher than in hepatosplenic patients. The murine model mirrored the human disease. Macrophages were the major source of OPN in human and murine acute schistosomiasis, while the ductular reaction maintains OPN production in hepatosplenic disease. Soluble egg antigens from S. mansoni induced OPN expression in primary human kupffer cells. Conclusions/Significance S. mansoni egg antigens induce the production of OPN by macrophages in the necrotic-exudative granulomas characteristic of acute schistosomiasis mansoni. Circulating OPN levels are upregulated in human and

  13. Sensitivity of Trout to Chronic Acute Exposure to Selenium

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Gissel; Nielsen, M. Gissel

    1978-01-01

    Trout were exposed to selenite (Na2SeO3) solutions of varying concentrations (0.1-100 ppm Se) for periods of up to 4 wk. A chronic exposure to 0.1 ppm Se or less is non-lethal to trout. Lethality at higher concentrations depends on the length of exposure. Trout that survive for 10 days in tap...

  14. Human exposure to bovine polyomavirus: a zoonosis

    Energy Technology Data Exchange (ETDEWEB)

    Parry, J.V.; Gardner, S.D.

    1986-01-01

    A competitive-type solid phase radioimmunoassay (RIA) was developed for the detection of antibody to bovine polyomavirus. Comparison of RIA and counter-immunoelectrophoresis (CIE) results on 273 cattle sera indicated that both techniques were detecting antibody of like specificity. Human sera from 256 blood donors, 219 people recently vaccinated against polio, rubella or rabies, 50 immunosuppressed patients and 472 people with various occupational exposure to cattle were tested for antibody to bovine polyomavirus, the foetal rhesus monkey kidney strain, (anti-FRKV) by RIA. Apart from one blood donor and one of 108 rabies vaccinees only those in close contact with cattle possessed anti-FRKV. Compared with 62 per cent seropositive in the natural hosts, cattle, 71 per cent of veterinary surgeons, 50 per cent of cattle farmers, 40 per cent of abattoir workers, 16 per cent of veterinary institute technical staff and 10 per cent of veterinary students were anti-FRKV positive. Our findings indicate that the theoretical hazard of FRKV infection from undetected contamination of current tissue culture derived vaccines may, in practice, be remote. Proposed wider use of primate kidney cells as substrates for new vaccines may increase this risk.

  15. Progress in human exposure assessment for biocidal products

    NARCIS (Netherlands)

    Hemmen, J.J. van

    2004-01-01

    An important shortcoming in our present knowledge required for risk assessment of biocidal products is the assessment of human exposure. This knowledge gap has been filled in a preliminary fashion with the TNsG on human exposure to biocidal products (available from the ECB website). Explicit User gu

  16. Human exposure assessment: Approaches for chemicals (REACH) and biocides (BPD)

    NARCIS (Netherlands)

    Hemmen, J.J. van; Gerritsen-Ebben, R.

    2008-01-01

    The approaches that are indicated in the various guidance documents for the assessment of human exposure for chemicals and biocides are summarised. This reflects the TNsG (Technical notes for Guidance) version 2: human exposure assessment for biocidal products (1) under the BPD (Biocidal Products Di

  17. Risk Analysis of Acute Or Chronic Exposure to Arsenic of the Inhabitants in a District of Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    Cristina Vázquez

    2016-09-01

    Full Text Available The arsenic occurrence in the water constitutes a serious world health concern due to its toxicity. Depending on the intensity and duration of exposure, this element can be acutely lethal or may have a wide range of health effects in humans and animals. In Argentina, the origin of arsenic is mainly natural, and related to different geological processes. The Argentinean concern about arsenic and its influence on human health dates back to the previous century. The disease ascribed to arsenic contamination was called ‘chronic regional endemic hydroarsenism’. It is produced by the consumption of water with high levels of this element. In our study, we focused in La Matanza district, a very populated site in the Buenos Aires Province. An increasing concern of the inhabitants of the area regarding health problems was detected. In order to establish a full view of arsenic exposure in the area, several matrices and targets were analyzed. As matrices, water and soil samples were analyzed. As targets, canine and human hair was studied. The aim of this study was to investigate acute and chronically exposure to arsenic of La Matanza inhabitants.

  18. Acute expanded perlite exposure with persistent reactive airway dysfunction syndrome.

    Science.gov (United States)

    Du, Chung-Li; Wang, Jung-Der; Chu, Po-Chin; Guo, Yue-Liang Leon

    2010-01-01

    Expanded perlite has been assumed as simple nuisance, however during an accidental spill out in Taiwan, among 24 exposed workers followed for more than 6 months, three developed persisted respiratory symptoms and positive provocation tests were compatible with reactive airway dysfunction syndrome. During simulation experiment expanded perlite is shown to be very dusty and greatly exceed current exposure permission level. Review of literature and evidence, though exposure of expanded perlite below permission level may be generally safe, precautionary protection of short term heavy exposure is warranted.

  19. Effects of Acute Exposures to Carbon Dioxide Upon Cognitive Functions

    Science.gov (United States)

    Scully, R. R.; Alexander, D. J.; Ryder, V. E.; Lam, C. W.; Statish, U.; Basner, M.

    2016-01-01

    Large quantities of carbon dioxide (CO2) originate from human metabolism and typically, within spacecraft, remain about 10-fold higher in concentration than at the earth's surface. There have been recurring complaints by crew members of episodes of "mental viscosity" adversely affecting their performance, and there is evidence from the International Space Station (ISS) that associates CO2 levels with reports of headaches by crewmembers. Additionally, there is concern that CO2 may contribute to vision impairment and intracranial pressure that has been observed in some crewmembers. Consequently, flight rules have been employed to control the level of CO2 below 4 mm Hg, which is well below the existing Spacecraft Maximum Allowable Concentration (SMAC) of 10 mm Hg for 24-hour exposures, and 5.3 mm Hg for exposures of 7 to 180 days. However, the flight rule imposed limit, which places additional demands upon resources and current technology, still exceeds the lower bound of the threshold range for reportable headaches (2 - 5 mm Hg). Headaches, while sometime debilitating themselves, are also symptoms that can provide evidence that physiological defense mechanisms have been breached. The causes of the headaches may elicit other subtle adverse effects that occur at CO2 levels well below that for headaches. The concern that CO2 may have effects at levels below the threshold for headaches appears to be substantiated in unexpected findings that CO2 at concentrations below 2 mm Hg substantially reduced some cognitive functions that are associated with the ability to make complex decisions in conditions that are characterized by volatility, uncertainty, complexity, ambiguity, and delayed feedback. These are conditions that could be encountered by crews in off-nominal situations or during the first missions beyond low earth orbit. If findings of the earlier study are confirmed in crew-like subjects, our findings would provide additional evidence that CO2 may need to be

  20. Pulmonary CT findings in acute mercury vapour exposure

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Manabu; Sato, Kimihiko; Heianna, Jyouiti; Hirano, Yoshinori; Omachi, Kohiti; Izumi, Jyunichi; Watarai, Jiro

    2001-01-01

    AIM: We describe the pulmonary computed tomography (CT) findings in acute mercury poisoning. MATERIALS AND METHODS: Initial (n= 8) and follow-up (n= 6) chest CT examinations in eight patients exposed to mercury vapour while cutting pipes in a sulphuric acid plant were reviewed. Of the eight patients, two were asymptomatic and had normal CT results, two were asymptomatic but had abnormalities on CT, and four had both acute symptoms and positive CT results. The patients were all men whose ages ranged from 37 to 54 years (mean, 49 years). RESULTS: Poorly defined nodules were present in five of six patients with positive CT findings, present alone in two patients or as part of a mixed pattern in three. They were random in distribution. Alveolar consolidation (n= 3) and areas of ground-glass opacity (n= 4) were observed and were more prominent in the most severely affected patients with the highest blood and urine level of mercury, predominantly in the upper and/or middle zone. These abnormal findings on CT resolved with (n= 1) or without (n= 5) steroid therapy. Pathological findings (n= 1) demonstrated acute interstitial changes predominantly with oedema. CONCLUSION: We report CT findings in eight patients acutely exposed to mercury vapour. The pulmonary injury was reversible on CT in these cases. Hashimoto, M. (2001)

  1. [Advances on research of human exposure to triclosan].

    Science.gov (United States)

    Jin, Chenye; Chen, Yiming; Zhang, Peiqi; Xiong, Zhezhen; Wang, Caifeng; Tian, Ying

    2016-03-01

    Triclosan, a broad-spectrum antimicrobial agent, was reported to have been widely detected in various human biological samples such as urine, blood and human milk among foreign populations. In China, limited reports have been found on human exposure to triclosan, and the reported urinary triclosan concentrations were significantly lower than that of American populations. Besides, the potential influencing factors still remain unclear regarding human exposure to triclosan, but evidences suggest that those in middle age and with higher household income and higher social class tend to have higher urinary triclosan concentrations. Furthermore, triclosan exposure tend to differ by sex, geography, heredity, metabolism and life style.

  2. Large-scale analysis of acute ethanol exposure in zebrafish development: a critical time window and resilience.

    Directory of Open Access Journals (Sweden)

    Shaukat Ali

    Full Text Available BACKGROUND: In humans, ethanol exposure during pregnancy causes a spectrum of developmental defects (fetal alcohol syndrome or FAS. Individuals vary in phenotypic expression. Zebrafish embryos develop FAS-like features after ethanol exposure. In this study, we ask whether stage-specific effects of ethanol can be identified in the zebrafish, and if so, whether they allow the pinpointing of sensitive developmental mechanisms. We have therefore conducted the first large-scale (>1500 embryos analysis of acute, stage-specific drug effects on zebrafish development, with a large panel of readouts. METHODOLOGY/PRINCIPAL FINDINGS: Zebrafish embryos were raised in 96-well plates. Range-finding indicated that 10% ethanol for 1 h was suitable for an acute exposure regime. High-resolution magic-angle spinning proton magnetic resonance spectroscopy showed that this produced a transient pulse of 0.86% concentration of ethanol in the embryo within the chorion. Survivors at 5 days postfertilisation were analysed. Phenotypes ranged from normal (resilient to severely malformed. Ethanol exposure at early stages caused high mortality (≥88%. At later stages of exposure, mortality declined and malformations developed. Pharyngeal arch hypoplasia and behavioral impairment were most common after prim-6 and prim-16 exposure. By contrast, microphthalmia and growth retardation were stage-independent. CONCLUSIONS: Our findings show that some ethanol effects are strongly stage-dependent. The phenotypes mimic key aspects of FAS including craniofacial abnormality, microphthalmia, growth retardation and behavioral impairment. We also identify a critical time window (prim-6 and prim-16 for ethanol sensitivity. Finally, our identification of a wide phenotypic spectrum is reminiscent of human FAS, and may provide a useful model for studying disease resilience.

  3. Assessing exposure to phthalates - the human biomonitoring approach.

    Science.gov (United States)

    Wittassek, Matthias; Koch, Holger Martin; Angerer, Jürgen; Brüning, Thomas

    2011-01-01

    Some phthalates are developmental and reproductive toxicants in animals. Exposure to phthalates is considered to be potentially harmful to human health as well. Based on a comprehensive literature research, we present an overview of the sources of human phthalate exposure and results of exposure assessments with special focus on human biomonitoring data. Among the general population, there is widespread exposure to a number of phthalates. Foodstuff is the major source of phthalate exposure, particularly for the long-chain phthalates such as di(2-ethylhexyl) phthalate. For short-chain phthalates such as di-n-butyl-phthalate, additional pathways are of relevance. In general, children are exposed to higher phthalate doses than adults. Especially, high exposures can occur through some medications or medical devices. By comparing exposure data with existing limit values, one can also assess the risks associated with exposure to phthalates. Within the general population, some individuals exceed tolerable daily intake values for one or more phthalates. In high exposure groups, (intensive medical care, medications) tolerable daily intake transgressions can be substantial. Recent findings from animal studies suggest that a cumulative risk assessment for phthalates is warranted, and a cumulative exposure assessment to phthalates via human biomonitoring is a major step into this direction.

  4. Human exposures to parabens in cosmetics - a literature study

    OpenAIRE

    Aarflot, Ragnhild Lønseth

    2013-01-01

    A literature study was performed in order to assess and compare evidence of human exposure to parabens in cosmetics. The focus of the thesis is on human concentrations, the rate of dermal absorption, metabolism and excretion; in order to increase our understanding of human exposures to endocrine disrupting chemicals in cosmetics. High detection rates of native and total parabens in blood and urine were identified. GMs of native parabens were lower than total paraben levels in urine as expecte...

  5. Behavioral and neurochemical changes in response to acute stressors: influence of previous chronic exposure to immobilization.

    Science.gov (United States)

    Pol, O; Campmany, L; Gil, M; Armario, A

    1992-07-01

    The effect of daily (2 h) exposure to immobilization (IMO) for 15 days on the behavioral and neurochemical responses of adult male rats to acute stress caused by 2-h IMO or 2-h tail-shock was studied. The brain areas studied were frontal cortex, hippocampus, hypothalamus, midbrain, and pons plus medulla. Chronic exposure to IMO did not alter noradrenaline (NA), 3-methoxy,4-hydroxyphenyletileneglycol-SO4 (MHPG-SO4), serotonin, or 5-hydroxindoleacetic acid (5-HIAA) concentrations in any brain area as measured approximately 20 h after the last exposure to IMO. Exposure to behavioral tests did not modify neurochemical variables except NA levels in the hypothalamus of nonchronically stressed (control) rats. Both exposure to 2-h IMO or 2-h shock significantly decreased NA levels in hypothalamus and midbrain of nonchronically stressed rats. These decreases in response to the two acute stressors were not observed in chronically stressed rats. However, MHPG-SO4 levels increased to the same extent in control and chronically stressed rats after exposure to the acute stressors. Likewise, increased 5-HIAA concentrations observed in response to acute stressors were similar in control and chronically stressed rats. The inhibition of activity (areas crossed and rearing) in the holeboard caused by acute IMO was less marked in rats previously exposed to the same stressor than in control rats, but the response to shock was similar. In the forced swim test, acute IMO decreased struggling in control rats but tended to increase it in chronically stressed rats. The response to shock followed the same pattern as that to IMO, although it was slight.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Catalase Activity in Brown Mussels (Perna perna) under Acute Cadmium, Lead, and Copper Exposure and Depuration Tests

    National Research Council Canada - National Science Library

    Boudjema, Kamel; Kourdali, Sidali; Bounakous, Nabila; Meknachi, Abdellah; Badis, Abdelmalek

    2014-01-01

      Brown mussels (Perna perna) were exposed to cadmium (Cd), lead (Pb), and copper (Cu) concentrations under acute exposure and exposure-depuration tests for the estimation of biochemical biomarker catalase...

  7. Tracking the pathways of human exposure to perfluorocarboxylates.

    Science.gov (United States)

    Vestergren, Robin; Cousins, Ian T

    2009-08-01

    Recent analyses of perfluorooctanoate (PFOA) in human blood sera show that the background-exposed population in industrialized countries worldwide exhibits a narrow concentration range; arithmetic means of published studies range between 2 and 8 microg/L PFOA, with the exception of a few outlier studies. The globally comparable human serum concentrations of PFOA and characteristic dominance of PFOA with respect to other perfluorocarboxylate (PFCA) homologues indicate that exposure pathways of humans differ from those of wildlife, where perfluorononanoate (PFNA) is often the dominant homologue. The observed correlations between perfluorooctane sulfonate (PFOS) and PFOA in human serum together with a simultaneous downward time trend of these compounds in human blood sera and blood spots from the year 2000 onward indicate a connection between historical perfluorooctanesulfonyl (POSF) production (phased out by the major manufacturer in 2000-2002) and exposure to both PFOS and PFOA. A comparison of estimated daily intakes to humans based on samples from exposure media (collected post 2000) indicates that food intake is the major contemporary exposure pathway for the background population, whereas drinking water exposure is dominant for populations near sources of contaminated drinking water. A one-compartment pharmacokinetic model used to back-calculate daily intakes from serum levels is shown to provide agreement within a factor of 1.5-5.5 of the daily intakes derived from exposure media, which provides further supporting evidence that dietary exposure is a major ongoing exposure pathway of PFOA to the background population.

  8. Impact of acute and chronic inhalation exposure to CdO nanoparticles on mice

    OpenAIRE

    Lebedová, J.; Bláhová, L.; Večeřa, Z. (Zbyněk); P. Mikuška; Dočekal, B. (Bohumil); Buchtová, M. (Marcela); Míšek, I. (Ivan); Dumková, J.; Hampl, A.; Hilscherová, K.

    2016-01-01

    Cadmium nanoparticles can represent a risk in both industrial and environmental settings, but there is little knowledge on the impacts of their inhalation, especially concerning longer-term exposures. In this study, mice were exposed to cadmium oxide (CdO) nanoparticles in whole body inhalation chambers for 4 to 72 h in acute and 1 to 13 weeks (24 h/day, 7 days/week) in chronic exposure to investigate the dynamics of nanoparticle uptake and effects. In the acute experiment, mice were ...

  9. Acute exposure to silica nanoparticles aggravate airway inflammation: different effects according to surface characteristics

    OpenAIRE

    Park, Hye Jung; Sohn, Jung-Ho; Kim, Yoon-Ju; Park, Yoon Hee; Han, Heejae; Park, Kyung Hee; Lee, Kangtaek; Choi, Hoon; Um, Kiju; Choi,In-Hong; Park, Jung-Won; Lee, Jae-Hyun

    2015-01-01

    Silica nanoparticles (SNPs) are widely used in many scientific and industrial fields despite the lack of proper evaluation of their potential toxicity. This study examined the effects of acute exposure to SNPs, either alone or in conjunction with ovalbumin (OVA), by studying the respiratory systems in exposed mouse models. Three types of SNPs were used: spherical SNPs (S-SNPs), mesoporous SNPs (M-SNPs), and PEGylated SNPs (P-SNPs). In the acute SNP exposure model performed, 6-week-old BALB/c ...

  10. Acute and chronic effects from pulse exposure of D. magna to silver and copper oxide nanoparticles.

    Science.gov (United States)

    Sørensen, Sara Nørgaard; Holten Lützhøft, Hans-Christian; Rasmussen, Rose; Baun, Anders

    2016-11-01

    Aquatic toxicity testing of nanoparticles (NPs) is challenged by their dynamic behavior in test suspensions. The resulting difficulties in controlling and characterizing exposure concentrations are detrimental to the generation of concentration-response data needed for hazard identification of NPs. This study explores the applicability of short-term (1, 2 and 3h) pulse exposures as means to keep the exposure stable and at the same time disclose acute and chronic effects of AgNPs and CuONPs in D. magna. Dissolution, agglomeration and sedimentation were found to have less influence on exposure concentrations during 1-3h pulses than for 24-48h continuous exposures. For AgNPs, preparation of test suspensions in medium 24h before toxicity testing (aging) increased stability during the short-term pulses. In pulse tests, organisms were exposed to the test materials, AgNPs and CuONPs for 1, 2 and 3h, and afterwards transferred to clean medium and observed for 48h (post-exposure period) for acute effects and for 21 d for chronic effects. AgNO3 and CuCl2 were used as reference materials for dissolved silver and copper, respectively. For all test materials, a 3h pulse caused comparable immobility in D. magna (observed after 48h post-exposure) as 24h continuous exposure, as evidenced by overlapping 95% confidence intervals of EC50-values. In the 21 d post-exposure period, no trends in mortality or body length were identified. AgNP and AgNO3 pulses had no effect on the number of moltings, days to first live offspring or cumulated number of offspring, but the number of offspring increased for AgNPs (3h pulse only). In contrast, CuONP and CuCl2 pulses decreased the number of moltings and offspring, and for CuONPs the time to first live offspring was prolonged. After CuONP exposures, the offspring production decreased more with increasing concentrations than for CuCl2 exposures when taking the measured dissolved copper into account. This indicates a nanoparticle-specific effect

  11. Commuters’ air pollution exposure and acute health effects

    NARCIS (Netherlands)

    Zuurbier, M.M.M.

    2011-01-01

    People spend a substantial proportion of their time in traffic. In Europe, the average daily time in traffic is one to one and a half hour. Because of high in-traffic exposures and because most of the journeys are made during rush hours, the one to one and a half hour in traffic contributes dispropo

  12. Commuters’ air pollution exposure and acute health effects

    NARCIS (Netherlands)

    Zuurbier, M.M.M.

    2011-01-01

    People spend a substantial proportion of their time in traffic. In Europe, the average daily time in traffic is one to one and a half hour. Because of high in-traffic exposures and because most of the journeys are made during rush hours, the one to one and a half hour in traffic contributes

  13. Wood smoke in a controlled exposure experiment with human volunteers.

    Science.gov (United States)

    Riddervold, I S; Bønløkke, J H; Mølhave, L; Massling, A; Jensen, B; Grønborg, T K; Bossi, R; Forchhammer, L; Kjærgaard, S K; Sigsgaard, T

    2011-04-01

    Exposure to wood smoke in the general population is increasing and concurrently, also our awareness. This article describes a wood-smoke generating system for studying human exposure to wood smoke and symptoms related to this exposure. Twenty nonsmoking atopic human participants with normal lung function and normal bronchial reactivity were randomly exposed for 3 h at three different exposure conditions; clean filtered air (control exposure) and wood smoke with a characteristic particulate matter (PM) concentration of 200 µg/m³ (low) and 400 µg/m³ (high) under controlled environmental conditions. The range for PM₂.₅ load observed for single experiments was 165-303 µg/m³ for the low exposure and 205-662 µg/m³ for the high exposure, whereas particle loads during clean air exposure most often were below the detection limit (humans. The knowledge gained in this study on subjective-rated symptoms may be important for understanding human response to wood-smoke exposure.

  14. Human exposure to emissions from building materials

    DEFF Research Database (Denmark)

    Kjærgaard, S.; Hauschildt, P.; Pejtersen, Jan;

    1999-01-01

    found on peak flow, eye foam formation, tear fluid cells, or conjunctival epithelial damage. Among subjective evaluations only sound intensity rating was significant. A correlation was found between acute nose irritation rating and change in nasal volume.Conclusions. The findings indicate physiological...

  15. Controlled exposures of human volunteers to sulfate aerosols. Health effects and aerosol characterization.

    Science.gov (United States)

    Avol, E L; Jones, M P; Bailey, R M; Chang, N M; Kleinman, M T; Linn, W S; Bell, K A; Hackney, J D

    1979-08-01

    Our laboratory has undertaken the study of possible acute adverse health effects of sulfate aerosols through controlled exposures of volunteer human subjects. Both healthy and asthmatic adult men were exposed for 2-hour periods (with intermittent exercise) to ammonium sulfate, ammonium bisulfate, and sulfuric acid of particle size distributions and concentrations intended to simulate "worst case" exposures during Los Angeles smog episodes. Lung function tests were performed by the subjects on entering and before exiting from a carefully controlled environmental chamber. Subject symptoms were evluated in a standardized manner. Aerosol concentrations and size distributions were determined by an on-line computer/aerometric monitoring system; gravimetric and chemical analyses were performed on impactor and total filter samples after test exposures. We found little or no evidence of adverse health effects from 2-hour multiple-day exposures to any of the compounds at "worst case" ambient concentrations.

  16. Humoral immunodepression following acute NO/sub 2/ exposure in normal and adrenalectomized mice

    Energy Technology Data Exchange (ETDEWEB)

    Azoulay-Dupuis, E.; Levacher, M.; Muffat-Joly, M.; Pocidalo, J.J.

    1985-01-01

    The effects following 20 ppm NO/sub 2/ exposure on humoral immunity were investigated in C57BI/6 mice after 48, 72, and 96 h exposure. Both spleen plaque-forming cell (PFC) responses and serum hemagglutinins (HA) using sheep red blood cells (SRBC) as antigen were studied. Splenic and thymic weight and cellularity decreased on acute exposure to NO/sub 2/. PFC were markedly depressed after 48 h exposure and continued to decrease as exposure time was lengthened. HA titers were also depressed. The same significant suppression of PFC and HA titers was observed in adrenalectomized mice after 96 h NO/sub 2/ exposure. The depression of humoral immunity in NO/sub 2/-exposed mice was independent of stress-induced endogeneous steroids.

  17. Inhale while Dreaming: Human Exposure to Pollutants while Sleeping

    DEFF Research Database (Denmark)

    Corsi, Richard; Spilak, Michal; Boor, E., Brandon

    2012-01-01

    Humans spend approximately 1/3 of their total life asleep, typically on a mattress or other bedding. Despite the fact that there is no other location where most of humanity spends more time, this microenvironment has received little attention from the standpoint of human exposure to a wide range ...

  18. Discriminating acute from chronic human schistosomiasis mansoni.

    Science.gov (United States)

    Beck, Lílian; Van-Lüme, Daniele S M; Souza, Joelma R; Domingues, Ana L C; Favre, Tereza; Abath, Frederico G C; Montenegro, Silvia M L

    2008-01-01

    Specific immunoglobulin (IgA, IgG and IgM) responses to different antigen targets (soluble eggs antigen--SEA, soluble worm adult protein--SWAP and keyhole limpet hole--KLH) were measured by enzyme linked immunosorbent assay (ELISA) in patients with acute and chronic schistosomiasis, as well as patients without schistosomiasis. SEA IgA and KLH IgM presented high discriminatory powers to distinguish acute from chronic schistosomiasis, with calculated areas under the curve (AUCs) of 0.88 and 0.82, respectively, obtained from receiver operating characteristic (ROC) curve. On the other hand, these tests, particularly SEA IgA were not useful to distinguish schistosomiasis (including the acute and chronic forms) from individuals without this disease, but infected with other intestinal parasites (Ascaris lumbricoides, Trichuris trichiura and hookworm). By contrast, SWAP IgG and SEA IgG were able to discriminate schistosomiasis patients from healthy individuals and patients infected with other parasites (AUCs of 0.96 and 0.85, respectively). Thus, it is possible to use a combination of serological tests, such as SEA IgA and SWAP IgG, to simultaneously establish the diagnosis of schistosomiasis and discriminate the acute from the chronic forms of the disease.

  19. Wood smoke in a controlled exposure experiment with human volunteers

    DEFF Research Database (Denmark)

    Riddervold, Ingunn Skogstad; Bønløkke, Jakob Hjort; Mølhave, Lars

    2011-01-01

    Exposure to wood smoke in the general population is increasing and concurrently, also our awareness. This article describes a wood-smoke generating system for studying human exposure to wood smoke and symptoms related to this exposure. Twenty nonsmoking atopic human participants with normal lung...... function and normal bronchial reactivity were randomly exposed for 3h at three different exposure conditions; clean filtered air (control exposure) and wood smoke with a characteristic particulate matter (PM) concentration of 200 µg/m3 (low) and 400 µg/m3 (high) under controlled environmental conditions.......0007), “irritative body perceptions” (p = 0.0127), “psychological/neurological effects” (p = 0.0075) and “weak inflammatory responses” (p = 0.0003). Furthermore, significant effects (p = 0.0192) on self-reported general mucosa irritation were found. In conclusion, exposure to wood smoke affected symptom rating...

  20. Chronic and acute effects of coal tar pitch exposure and cardiopulmonary mortality among aluminum smelter workers.

    Science.gov (United States)

    Friesen, Melissa C; Demers, Paul A; Spinelli, John J; Eisen, Ellen A; Lorenzi, Maria F; Le, Nhu D

    2010-10-01

    Air pollution causes several adverse cardiovascular and respiratory effects. In occupational studies, where levels of particulate matter and polycyclic aromatic hydrocarbons (PAHs) are higher, the evidence is inconsistent. The effects of acute and chronic PAH exposure on cardiopulmonary mortality were examined within a Kitimat, Canada, aluminum smelter cohort (n = 7,026) linked to a national mortality database (1957-1999). No standardized mortality ratio was significantly elevated compared with the province's population. Smoking-adjusted internal comparisons were conducted using Cox regression for male subjects (n = 6,423). Ischemic heart disease (IHD) mortality (n = 281) was associated with cumulative benzo[a]pyrene (B(a)P) exposure (hazard ratio = 1.62, 95% confidence interval: 1.06, 2.46) in the highest category. A monotonic but nonsignificant trend was observed with chronic B(a)P exposure and acute myocardial infarction (n = 184). When follow-up was restricted to active employment, the hazard ratio for IHD was 2.39 (95% confidence interval: 0.95, 6.05) in the highest cumulative B(a)P category. The stronger associations observed during employment suggest that risk may not persist after exposure cessation. No associations with recent or current exposure were observed. IHD was associated with chronic (but not current) PAH exposure in a high-exposure occupational setting. Given the widespread workplace exposure to PAHs and heart disease's high prevalence, even modest associations produce a high burden.

  1. Environmental chemical exposures and human epigenetics

    Science.gov (United States)

    Hou, Lifang; Zhang, Xiao; Wang, Dong; Baccarelli, Andrea

    2012-01-01

    Every year more than 13 million deaths worldwide are due to environmental pollutants, and approximately 24% of diseases are caused by environmental exposures that might be averted through preventive measures. Rapidly growing evidence has linked environmental pollutants with epigenetic variations, including changes in DNA methylation, histone modifications and microRNAs. Environ mental chemicals and epigenetic changes All of these mechanisms are likely to play important roles in disease aetiology, and their modifications due to environmental pollutants might provide further understanding of disease aetiology, as well as biomarkers reflecting exposures to environmental pollutants and/or predicting the risk of future disease. We summarize the findings on epigenetic alterations related to environmental chemical exposures, and propose mechanisms of action by means of which the exposures may cause such epigenetic changes. We discuss opportunities, challenges and future directions for future epidemiology research in environmental epigenomics. Future investigations are needed to solve methodological and practical challenges, including uncertainties about stability over time of epigenomic changes induced by the environment, tissue specificity of epigenetic alterations, validation of laboratory methods, and adaptation of bioinformatic and biostatistical methods to high-throughput epigenomics. In addition, there are numerous reports of epigenetic modifications arising following exposure to environmental toxicants, but most have not been directly linked to disease endpoints. To complete our discussion, we also briefly summarize the diseases that have been linked to environmental chemicals-related epigenetic changes. PMID:22253299

  2. Effects of Acute Exposure to Increased Plasma Branched-Chain Amino Acid Concentrations on Insulin-Mediated Plasma Glucose Turnover in Healthy Young Subjects

    OpenAIRE

    Sarah Everman; Mandarino, Lawrence J.; Carroll, Chad C.; Katsanos, Christos S.

    2015-01-01

    Background Plasma branched-chain amino acids (BCAA) are inversely related to insulin sensitivity of glucose metabolism in humans. However, currently, it is not known whether there is a cause-and-effect relationship between increased plasma BCAA concentrations and decreased insulin sensitivity. Objective To determine the effects of acute exposure to increased plasma BCAA concentrations on insulin-mediated plasma glucose turnover in humans. Methods Ten healthy subjects were randomly assigned to...

  3. Human Health and Exposure to Electromagnetic Radiation

    Science.gov (United States)

    1992-07-01

    incidence rates (SIRs) for the different forms of leukaemia were significantly elevated at the 5% level for several occupations (Linet and Cartwright ...to electrical and magnetic fields. N. Engl. J. Med., = 1476-1477. Canwright, R A, Darwin , C, McKinney, P A, Roberts, A. Richards, I D G, and Bird, C C...Increased risk of developing acute leukaemia after employment as a painter. Cancer, 6N, 1378-1387. Linet, M S, and Cartwright , R A, 1988. Chronic

  4. Occupational exposure to particles and incidence of acute myocardial infarction and other ischaemic heart disease.

    Science.gov (United States)

    Wiebert, Pernilla; Lönn, Maria; Fremling, Karin; Feychting, Maria; Sjögren, Bengt; Nise, Gun; Kauppinen, T; Plato, Nils; Gustavsson, Per

    2012-09-01

    Ambient particulate air pollution has been linked to cardiovascular disease. Occupational particle exposure levels may be several times higher than ambient levels but has been less studied. The authors investigated the association between occupational exposure to particles and the incidence of ischaemic heart disease (IHD). The cohort included all manual workers in the Swedish national census of 1980 with information on demographic data and occupation. Information on hospital admissions for acute myocardial infarction or other IHDs and cause of death were obtained from nation-wide registers. A job-exposure matrix for exposure to small (1 μm) particles was developed. HRs were calculated with Cox regression with adjustment for sex, age, socioeconomic group and urban/rural residential area. Exposure to small particles was associated with an increased HR for acute myocardial infarction of 1.12 (95% CI 1.09 to 1.15), and HR for exposure to large particles was 1.14 (95% CI 1.10 to 1.18). The association was somewhat stronger for workers exposed to small particles for more than 5 years, 1.21 (95% CI 1.11 to 1.31), but no trend with exposure intensity was found. The risk associated with exposure to small particles was higher among women than among men, 1.30 (95% CI 1.12 to 1.51) and 1.10 (95% CI 1.07 to 1.14), respectively. Findings were essentially similar for other IHDs. This explorative study gives some support to the hypothesis that occupational exposure to particles increases the risk of acute myocardial infarction and other IHD. The findings must be interpreted cautiously due to lack of smoking data.

  5. Human Health Effects Associated with Exposure to Toxic Cyanobacteria

    Science.gov (United States)

    Reports of toxic cyanobacteria blooms are increasing worldwide. Warming and eutrophic surface water systems support the development of blooms. We examine the evidence for adverse human health effects associated with exposure to toxic blooms in drinking water, recreational water a...

  6. Knowledge of human immunodeficiency virus post-exposure ...

    African Journals Online (AJOL)

    Knowledge of human immunodeficiency virus post-exposure prophylaxis among doctors in a Nigerian tertiary hospital. ... of PEP policy in the hospital. The level of knowledge concerning the high-risk fluid and three drugs used in PEP is high.

  7. Human Health Effects Associated with Exposure to Toxic Cyanobacteria

    Science.gov (United States)

    Reports of toxic cyanobacteria blooms are increasing worldwide. Warming and eutrophic surface water systems support the development of blooms. We examine the evidence for adverse human health effects associated with exposure to toxic blooms in drinking water, recreational water a...

  8. Self-reported acute health symptoms and exposure to companion animals#

    Science.gov (United States)

    Self-reported acute health symptoms and exposure to companion animalsWhitney S. Krueger1,2, Elizabeth D. Hilborn2, Timothy J. Wade21Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA2Environmental Public Health Division, Office of Research and Development, U...

  9. In Utero Exposure to Lipopolysaccharide Alters the Postnatal Acute Phase Response in Beef Heifers

    Science.gov (United States)

    This study was designed to determine the potential effect of prenatal lipopolysaccharide (LPS) exposure on the postnatal acute phase response (APR) to an LPS challenge in heifers. Pregnant crossbred cows (n = 50) were separated into prenatal immune stimulation (PIS; n = 25; administered 0.1 microgr...

  10. TOXICITY PATHWAY ANALYSIS IN AGING BROWN NORWAY RAT BRAIN FOLLOWING ACUTE TOLUENE EXPOSURE

    Science.gov (United States)

    The influence of aging on susceptibility to environmental stressors is poorly understood. To investigate the contribution of different life stages on response to toxicants, we examined the effects of acute exposure by oral gavage of the volatile organic solvent toluene (0.00, 0.3...

  11. TOXICITY PATHWAY ANALYSIS IN AGING BROWN NORWAY RAT BRAIN FOLLOWING ACUTE TOLUENE EXPOSURE

    Science.gov (United States)

    The influence of aging on susceptibility to environmental stressors is poorly understood. To investigate the contribution of different life stages on response to toxicants, we examined the effects of acute exposure by oral gavage of the volatile organic solvent toluene (0.00, 0.3...

  12. Striatal dopamine dynamics in mice following acute and repeated toluene exposure.

    Science.gov (United States)

    Apawu, Aaron K; Mathews, Tiffany A; Bowen, Scott E

    2015-01-01

    The abused inhalant toluene has potent behavioral effects, but only recently has progress been made in understanding the neurochemical actions that mediate the action of toluene in the brain. Available evidence suggests that toluene inhalation alters dopamine (DA) neurotransmission, but toluene's mechanism of action is unknown. The present study evaluated the effect of acute and repeated toluene inhalation (0, 2,000, or 4,000 ppm) on locomotor activity as well as striatal DA release and uptake using slice fast-scan cyclic voltammetry. Acutely, 2,000 and 4,000 ppm toluene increased locomotor activity, while neurochemically only 4,000 ppm toluene potentiated electrically evoked DA release across the caudate-putamen and the nucleus accumbens. Repeated administration of toluene resulted in sensitization to toluene's locomotor activity effects. Brain slices obtained from mice repeatedly exposed to toluene demonstrated no difference in stimulated DA release in the caudate-putamen as compared to control animals. Repeated exposure to 2,000 and 4,000 ppm toluene caused a concentration-dependent decrease of 25-50 % in evoked DA release in the nucleus accumbens core and shell relative to air-exposed mice. These voltammetric neurochemical findings following repeated toluene exposure suggest that there may be a compensatory downregulation of the DA system. Acute or repeated toluene exposure had no effect on the DA uptake kinetics. Taken together, these results demonstrate that acute toluene inhalation potentiates DA release, while repeated toluene exposure attenuates DA release in the nucleus accumbens only.

  13. Neurobehavorial effects of acute exposure to four solvents: meta-abalyses

    Science.gov (United States)

    Meta-and re-analyses of the available data for the neurobehavioral effects of acute inhalation exposure to toluene were reported by Benignus et al. (2007). The present study was designed to test the generality of the toluene results in as many other solvents as possible by furthe...

  14. Pathogenesis of Acute and Delayed Corneal Lesions after Ocular Exposure to Sulfur Mustard Vapor

    Science.gov (United States)

    2012-01-01

    had poor outcomes. Using a rabbit corneal vapor exposure model, we previously demonstrated a clinical progression with acute and chronic sequelae...can cause a permanent reduction in visual acuity or complete loss of eyesight [6]. The pathogenesis of MGK has been clinically described as a chronic

  15. Exposure to ozone modulates human airway protease/antiprotease balance contributing to increased influenza A infection.

    Directory of Open Access Journals (Sweden)

    Matthew J Kesic

    Full Text Available Exposure to oxidant air pollution is associated with increased respiratory morbidities and susceptibility to infections. Ozone is a commonly encountered oxidant air pollutant, yet its effects on influenza infections in humans are not known. The greater Mexico City area was the primary site for the spring 2009 influenza A H1N1 pandemic, which also coincided with high levels of environmental ozone. Proteolytic cleavage of the viral membrane protein hemagglutinin (HA is essential for influenza virus infectivity. Recent studies suggest that HA cleavage might be cell-associated and facilitated by the type II transmembrane serine proteases (TTSPs human airway trypsin-like protease (HAT and transmembrane protease, serine 2 (TMPRSS2, whose activities are regulated by antiproteases, such as secretory leukocyte protease inhibitor (SLPI. Based on these observations, we sought to determine how acute exposure to ozone may modulate cellular protease/antiprotease expression and function, and to define their roles in a viral infection. We utilized our in vitro model of differentiated human nasal epithelial cells (NECs to determine the effects of ozone on influenza cleavage, entry, and replication. We show that ozone exposure disrupts the protease/antiprotease balance within the airway liquid. We also determined that functional forms of HAT, TMPRSS2, and SLPI are secreted from human airway epithelium, and acute exposure to ozone inversely alters their expression levels. We also show that addition of antioxidants significantly reduces virus replication through the induction of SLPI. In addition, we determined that ozone-induced cleavage of the viral HA protein is not cell-associated and that secreted endogenous proteases are sufficient to activate HA leading to a significant increase in viral replication. Our data indicate that pre-exposure to ozone disrupts the protease/antiprotease balance found in the human airway, leading to increased influenza susceptibility.

  16. Physiological responses to exposure to carbon dioxide and human bioeffluents

    DEFF Research Database (Denmark)

    Zhang, Xiaojing; Wargocki, Pawel; Lian, Zhiwei

    2015-01-01

    different cognitive tasks and assessed their comfort and acute health symptoms. Besides, the following were determined: heart rate, blood pressure, oxygen saturation of blood, respiration rate, minute ventilation rate, nasal peak flow, forced expiratory volume, and the end-tidal CO2 pressure (ETCO2). Saliva...... with bioeffluents, the performance of Tsai-Partington test was reduced, and diastolic blood pressure and alpha-amylase increased after exposure compared with their levels before exposure, which may suggest higher arousal/stress. During exposure to CO2 without bioeffluents, the performance of Tsai-Partington test...... also was lower, which may suggest higher stress/arousal, too. However, no effects on blood pressure and alpha-amylase were seen for this exposure....

  17. A Method for Quantifying the Acute Health Impacts of Residential Non-Biological Exposure Via Inhalation

    Energy Technology Data Exchange (ETDEWEB)

    Logue, Jennifer M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Sherman, Max H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Bret C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2014-08-01

    The inability to monetize the health costs of acute exposures in homes and the benefits of various control options is a barrier to justifying policies and approaches that can reduce exposure and improve health.We synthesized relationships between short-term outdoor concentration changes and health outcomes to estimate the health impacts of short-term in-home exposures. Damage and cost impacts of specific health outcomes were taken from the literature. We assessed the impact of vented and non-vented residential natural gas cooking burners on Southern California occupants for two pollutants (NO2 and CO).

  18. Acute phase proteins in cattle after exposure to complex stress

    DEFF Research Database (Denmark)

    Lomborg, S. R.; Nielsen, L. R.; Heegaard, Peter M. H.

    2008-01-01

    Abstract Stressors such as weaning, mixing and transportation have been shown to lead to increased blood concentrations of acute phase proteins (APP), including serum amyloid A (SAA) and haptoglobin, in calves. This study was therefore undertaken to assess whether SAA and haptoglobin levels...... in blood mirror stress in adult cattle. Six clinically healthy Holstein cows and two Holstein heifers were transported for four to six hours to a research facility, where each animal was housed in solitary tie stalls. Blood samples for evaluation of leukocyte counts and serum SAA and haptoglobin...... concentrations were obtained before (0-sample) and at 8, 24 and 48 hours after the start of transportation. Upon arrival the animals gave the impression of being anxious, and they appeared to have difficulty coping with isolation and with being tied on the slippery floors of the research stable. Serum...

  19. Parabens as Urinary Biomarkers of Exposure in Humans

    OpenAIRE

    Ye, Xiaoyun; Bishop, Amber M.; Reidy, John A; Needham, Larry L.; Calafat, Antonia M

    2006-01-01

    Background Parabens appear frequently as antimicrobial preservatives in cosmetic products, in pharmaceuticals, and in food and beverage processing. In vivo and in vitro studies have revealed weak estrogenic activity of some parabens. Widespread use has raised concerns about the potential human health risks associated with paraben exposure. Objectives Assessing human exposure to parabens usually involves measuring in urine the conjugated or free species of parabens or their metabolites. In ani...

  20. Acute and Chronic Exposure to CO2 in Space Flight

    Science.gov (United States)

    Alexander, D.; Wu, J.; Barr, Y. R.; Watkins, S. D.

    2010-01-01

    Spacecraft and space stations, similar to other habitable confined spaces such as submarines, need to provide a breathable atmosphere for their inhabitants. The inevitable production of CO2 during respiration necessitates life support systems that "scrub" the atmosphere and lower CO2 levels. Due to operational limitations associated with space flight (limited mass, volume, power, and consumables) CO2 is not scrubbed down to its terrestrial equivalent of 0.03% CO2 (ppCO2 of 0.23 mmHg), but is kept below 0.7% (ppCO2 of 5.3 mmHg), a level established in NASA s 180-day mission Spacecraft Maximum Allowable Concentration (SMAC) to be safe and unlikely to cause symptoms. Reports of space flight crewmembers becoming symptomatic with headaches, fatigue, and malaise at levels below those known to cause such symptoms terrestrially has prompted studies measuring the levels of CO2 on both the space shuttle and the space station. Data from cabin atmosphere sampling were collected on space shuttle missions STS-113, STS-122, STS-123, and International Space Station Expeditions 12-15 and 17, and the measured CO2 levels were then correlated to symptoms reported by the crew. The results indicate that a correlation exists between CO2 levels and symptomatology, however causality cannot be established at this time. While the short-term effects of elevated CO2 exposure are well known terrestrially, less is known regarding potential long-term effects of prolonged exposure to a CO2-rich environment or how the physiological changes caused by microgravity may interact with such exposures. Other challenges include limitations in the CO2 monitors used, lack of convection in the microgravity environment, and formation of localized CO2 pockets. As it is unclear if the unique environment of space increases sensitivity to CO2 or if other confounding factors are present, further research is planned to elucidate these points. At the same time, efforts are underway to update the SMAC to a lower level

  1. Persistence of Breakage in Specific Chromosome Bands 6 Years after Acute Exposure to Oil

    Science.gov (United States)

    Francés, Alexandra; Hildur, Kristin; Barberà, Joan Albert; Rodríguez-Trigo, Gema; Zock, Jan-Paul; Giraldo, Jesús; Monyarch, Gemma; Rodriguez-Rodriguez, Emma; de Castro Reis, Fernanda; Souto, Ana; Gómez, Federico P.; Pozo-Rodríguez, Francisco; Templado, Cristina; Fuster, Carme

    2016-01-01

    analyses were performed in 47 exposed individuals. A total of 251 breakpoints in exposed individuals) were identified, showing a non-uniform distribution in the human ideogram. Ten chromosome bands were found to be especially prone to breakage through both statistical methods. By comparing these bands with those observed in certain exposed individuals who had already participated the previous study, it was found in both studies that four bands (2q21, 3q27, 5q31 and 17p11.2) are particularly sensitive to breakage. Additionally, the dysfunction in DNA repair mechanisms was not significantly higher in oil-exposed individuals than in non-exposed individuals. Limitations The sample size and the possibility of some kind of selection bias should be considered. Genotoxic results cannot be extrapolated to the high number of individuals who participated occasionally in clean-up tasks. Conclusion Our findings show the existence of at least four target bands (2q21, 3q27, 5q31 and 17p11.2) with a greater propensity to break over time after an acute exposure to oil. The breaks in these bands, which are commonly involved in hematological cancer, may explain the increase of cancer risk reported in chronically benzene-exposed individuals. In addition, a more efficiency of the DNA repair mechanisms has been detected six years after in fishermen who were highly exposed to the oil spill. To date, only this study, performed by our group on the previous and present genotoxic effects, has analyzed the chromosomal regions affected by breakage after an acute oil exposure. PMID:27479010

  2. Chronic boron exposure and human semen parameters.

    Science.gov (United States)

    Robbins, Wendie A; Xun, Lin; Jia, Juan; Kennedy, Nola; Elashoff, David A; Ping, Liu

    2010-04-01

    Boron found as borates in soil, food, and water has important industrial and medical applications. A panel reviewing NTP reproductive toxicants identified boric acid as high priority for occupational studies to determine safe versus adverse reproductive effects. To address this, we collected boron exposure/dose measures in workplace inhalable dust, dietary food/fluids, blood, semen, and urine from boron workers and two comparison worker groups (n=192) over three months and determined correlations between boron and semen parameters (total sperm count, sperm concentration, motility, morphology, DNA breakage, apoptosis and aneuploidy). Blood boron averaged 499.2 ppb for boron workers, 96.1 and 47.9 ppb for workers from high and low environmental boron areas (pBoron concentrated in seminal fluid. No significant correlations were found between blood or urine boron and adverse semen parameters. Exposures did not reach those causing adverse effects published in animal toxicology work but exceeded those previously published for boron occupational groups.

  3. Susceptibility of human populations to environmental exposure to organic contaminants.

    Science.gov (United States)

    Undeman, Emma; Brown, Trevor N; Wania, Frank; McLachlan, Michael S

    2010-08-15

    Environmental exposure to organic contaminants is a complex function of environmental conditions, food chain characteristics, and chemical properties. In this study the susceptibility of various human populations to environmental exposure to neutral organic contaminants was compared. An environmental fate model and a linked bioaccumulation model were parametrized to describe ecosystems in different climatic regions (temperate, arctic, tropical, and steppe). The human body burden resulting from constant emissions of hypothetical chemicals was estimated for each region. An exposure susceptibility index was defined as the body burden in the region of interest normalized to the burden of the same chemical in a reference human from the temperate region eating an average diet. For most persistent chemicals emitted to air, the Arctic had the highest susceptibility index (max 520). Susceptibility to exposure was largely determined by the food web properties. The properties of the physical environment only had a marked effect when air or water, not food, was the dominant source of human exposure. Shifting the mode of emission markedly changed the relative susceptibility of the ecosystems in some cases. The exposure arising from chemical use clearly varies between ecosystems, which makes an understanding of ecosystem susceptibility to exposure important for chemicals management.

  4. Acrolein and Human Disease: Untangling the Knotty Exposure Scenarios Accompanying Several Diverse Disorders.

    Science.gov (United States)

    Burcham, Philip C

    2017-01-17

    Acrolein is a highly toxic electrophile that participates in many diseases, yet efforts to delineate its precise mechanistic contributions to specific conditions are complicated by its wide distribution within human environments. This Perspective develops the proposal that due to its mixed status as environmental pollutant, metabolic byproduct, and endotoxicant which forms via ubiquitous pathophysiological processes, many diseases likely involve acrolein released from multiple sources. Although the category boundaries are indistinct, at least four identifiable exposure scenarios are identifiable. First, in some syndromes, such as those accompanying chronic or acute intoxication with smoke, whatever role acrolein plays in disease pathogenesis mainly traces to exogenous sources such as the combustion of tobacco or other organic matter. A second exposure category involves xenobiotics that undergo metabolism within the body to release acrolein. Still other health conditions, however, involve acrolein that forms via several endogenous pathways, some of which are activated upon intoxication with xenobiotics (i.e., Exposure Category 3), while still others accompany direct physical trauma to body tissues (Exposure Category 4). Further complicating efforts to clarify the role of endogenous acrolein in human disease is the likelihood that many such syndromes are complex phenomena that resemble "chemical mixture exposures" by involving multiple toxic substances simultaneously. This Perspective contends that while recent decades have witnessed much progress in describing the deleterious effects of acrolein at the cellular and molecular levels, more work is needed to define the contributions of different acrolein sources to "real-world" health conditions in human subjects.

  5. Ceftriaxone attenuates locomotor activity induced by acute and repeated cocaine exposure in mice.

    Science.gov (United States)

    Tallarida, Christopher S; Corley, Gladys; Kovalevich, Jane; Yen, William; Langford, Dianne; Rawls, Scott M

    2013-11-27

    Ceftriaxone (CTX) decreases locomotor activation produced by initial cocaine exposure and attenuates development of behavioral sensitization produced by repeated cocaine exposure. An important question that has not yet been answered is whether or not CTX reduces behavioral sensitization to cocaine in cases in which the antibiotic is administered only during the period of cocaine absence that follows repeated cocaine exposure and precedes reintroduction to cocaine. We investigated this question using C57BL/6 mice. Mice pretreated with cocaine (15mg/kg×14 days) and then challenged with cocaine (15mg/kg) after 30 days of cocaine absence displayed sensitization of locomotor activity. For combination experiments, CTX injected during the 30 days of cocaine absence attenuated behavioral sensitization produced by cocaine challenge. In the case in which CTX was injected together with cocaine for 14 days, development of behavioral sensitization to cocaine challenge was also reduced. CTX attenuated the increase in locomotor activity produced by acute cocaine exposure; however, its efficacy was dependent on the dose of cocaine as inhibition was detected against 30mg/kg, but not 15mg/kg, of cocaine. These results from mice indicate that CTX attenuates locomotor activity produced by acute and repeated cocaine exposure and counters cocaine's locomotor activating properties in a paradigm in which the antibiotic is injected during the period of forced cocaine absence that follows repeated cocaine exposure.

  6. Factors affecting the estimated probabilistic acute dietary exposure to captan from apple consumption.

    Science.gov (United States)

    Zentai, A; Sali, J; Szabó, I J; Szeitzné-Szabó, M; Ambrus, A; Vásárhelyi, A

    2013-01-01

    The effect of the number of pesticide residue values below the LOQ/LOD of analytical methods, the variability of residues in individual fruits, mass of fruit units and the number of bootstrap iterations was studied on the probabilistically estimated acute exposure of consumers. The 4720 daily apple consumption data and the results of 1239 apple sample analyses for captan residues, performed within the Hungarian monitoring programme between 2005 and 2011, were used in this study as model matrix. Up to about 95th percentile exposure (µg/(kg bw·day)), simply multiplying each residue in composite samples with each consumption value gave similar estimates to those obtained with the complex procedure taking also into account the mass of and residues in individual fruits. However, the exposure above the 95th percentile calculated with the complex procedure gradually increased with increasing percentile level compared to the simple procedure. Including the high number of non-detects reduced the estimated exposure, which was the highest when only the residues measured in treated fruits were taken into account. The number of bootstrap iterations between 100 and 10,000 did not significantly affect the calculated exposure. The 99.99th percentile exposure amounted to 17.9% of the acute reference dose of 300 µg/(kg bw·day) for women of childbearing age.

  7. Mimicking exposures to acute and lifetime concentrations of inhaled silver nanoparticles by two different in vitro approaches

    Directory of Open Access Journals (Sweden)

    Fabian Herzog

    2014-08-01

    Full Text Available In the emerging market of nano-sized products, silver nanoparticles (Ag NPs are widely used due to their antimicrobial properties. Human interaction with Ag NPs can occur through the lung, skin, gastrointestinal tract, and bloodstream. However, the inhalation of Ag NP aerosols is a primary concern. To study the possible effects of inhaled Ag NPs, an in vitro triple cell co-culture model of the human alveolar/airway barrier (A549 epithelial cells, human peripheral blood monocyte derived dendritic and macrophage cells together with an air–liquid interface cell exposure (ALICE system was used in order to reflect a real-life exposure scenario. Cells were exposed at the air–liquid interface (ALI to 0.03, 0.3, and 3 µg Ag/cm2 of Ag NPs (diameter 100 nm; coated with polyvinylpyrrolidone: PVP. Ag NPs were found to be highly aggregated within ALI exposed cells with no impairment of cell morphology. Furthermore, a significant increase in release of cytotoxic (LDH, oxidative stress (SOD-1, HMOX-1 or pro-inflammatory markers (TNF-α, IL-8 was absent. As a comparison, cells were exposed to Ag NPs in submerged conditions to 10, 20, and 30 µg Ag/mL. The deposited dose per surface area was estimated by using a dosimetry model (ISDD to directly compare submerged vs ALI exposure concentrations after 4 and 24 h. Unlike ALI exposures, the two highest concentrations under submerged conditions promoted a cytotoxic and pro-inflammatory response after 24 h. Interestingly, when cell cultures were co-incubated with lipopolysaccharide (LPS, no synergistic inflammatory effects were observed. By using two different exposure scenarios it has been shown that the ALI as well as the suspension conditions for the lower concentrations after 4 h, reflecting real-life concentrations of an acute 24 h exposure, did not induce any adverse effects in a complex 3D model mimicking the human alveolar/airway barrier. However, the highest concentrations used in the ALI setup, as well

  8. Sampling strategy for estimating human exposure pathways to consumer chemicals

    Directory of Open Access Journals (Sweden)

    Eleni Papadopoulou

    2016-03-01

    Full Text Available Human exposure to consumer chemicals has become a worldwide concern. In this work, a comprehensive sampling strategy is presented, to our knowledge being the first to study all relevant exposure pathways in a single cohort using multiple methods for assessment of exposure from each exposure pathway. The selected groups of chemicals to be studied are consumer chemicals whose production and use are currently in a state of transition and are; per- and polyfluorinated alkyl substances (PFASs, traditional and “emerging” brominated flame retardants (BFRs and EBFRs, organophosphate esters (OPEs and phthalate esters (PEs. Information about human exposure to these contaminants is needed due to existing data gaps on human exposure intakes from multiple exposure pathways and relationships between internal and external exposure. Indoor environment, food and biological samples were collected from 61 participants and their households in the Oslo area (Norway on two consecutive days, during winter 2013-14. Air, dust, hand wipes, and duplicate diet (food and drink samples were collected as indicators of external exposure, and blood, urine, blood spots, hair, nails and saliva as indicators of internal exposure. A food diary, food frequency questionnaire (FFQ and indoor environment questionnaire were also implemented. Approximately 2000 samples were collected in total and participant views on their experiences of this campaign were collected via questionnaire. While 91% of our participants were positive about future participation in a similar project, some tasks were viewed as problematic. Completing the food diary and collection of duplicate food/drink portions were the tasks most frequent reported as “hard”/”very hard”. Nevertheless, a strong positive correlation between the reported total mass of food/drinks in the food record and the total weight of the food/drinks in the collection bottles was observed, being an indication of accurate performance

  9. Investigating the synchronization of hippocampal neural network in response to acute nicotine exposure

    Directory of Open Access Journals (Sweden)

    Akay Metin

    2010-07-01

    Full Text Available Abstract Previous studies suggested that γ oscillations in the brain are associated with higher order cognitive function including selective visual attention, motor task planning, sensory perception, working memory and dreaming REM sleep. These oscillations are mainly observed in cortical regions and also occur in neocortical and subcortical areas and the hippocampus. In this paper, we investigate the influence of acute exposure to nicotine on the complexity of hippocampal γ oscillations. Using the approximate entropy method, the influence of acute nicotine exposure on the hippocampal γ oscillations was investigated. The hippocampal γ oscillations have been generated in response to the 100 Hz stimulus and isolated using the visual inspection and spectral analysis method. Our central hypothesis is that acute exposure to nicotine significantly reduces the complexity of hippocampal γ oscillations. We used brain-slice recordings and the approximate entropy method to test this hypothesis. The approximate entropy (complexity values of the hippocampal γ oscillations are estimated from the 14 hippocampal slices. Our results show that it takes at least 100 msec to see any hippocampal activities in response to the 100 Hz stimulus. These patterns noticeably changed after 100 msec until 300 msec after the stimulus Finally, they were less prominent after 300 msec. We have analyzed the isolated hippocampal γ oscillations (between 150 and 250 msec after the stimulus using the approximate entropy (ApEn method. Our results showed that the ApEn (complexity values of hippocampal γ oscillations during nicotine exposure were reduced compared to those of hippocampal γ oscillations during control, and washout. This reduction was much more significant in response to acute nicotine exposure (p

  10. Detection of human metapneumovirus from children with acute otitis media.

    Science.gov (United States)

    Suzuki, Akira; Watanabe, Oshi; Okamoto, Michiko; Endo, Hiroko; Yano, Hisakazu; Suetake, Mitsuko; Nishimura, Hidekazu

    2005-07-01

    Nasal and middle ear specimens collected from children with acute otitis media were subjected to viral isolation and bacteria culture. All virus-negative specimens underwent reverse transcription polymerase chain reaction to detect human metapneumovirus. Three of 126 middle ear specimens were positive by this assay.

  11. Biomonitoring human exposure to environmental carcinogenic chemicals

    DEFF Research Database (Denmark)

    Farmer, P.B.; Sepai, O.; Lawrence, R.

    1996-01-01

    aberrations and sister chromatid exchanges) and mutation frequency was estimated at a number of loci including the hprt gene and genes involving in cancer development. Blood and urine samples from individuals exposed to urban pollution were collected. Populations exposed through occupational or medical......A coordinated study was carried out on the development, evaluation and application of biomonitoring procedures for populations exposed to environmental genotoxic pollutants. The procedures used involved both direct measurement of DNA or protein damage (adducts) and assessment of second biological...... for detecting carcinogen-induced damage to DNA and proteins, and subsequent biological effects. These methods were validated with the occupational exposures, which showed evidence of DNA and/or protein and/or chromosome damage in workers in a coke oven plant, garage workers exposed to diesel exhaust and workers...

  12. Fructose ingestion acutely stimulates circulating FGF21 levels in humans

    OpenAIRE

    Dushay, Jody R.; Toschi, Elena; Mitten, Emilie K.; Fisher, ffolliott M.; Herman, Mark A.; Maratos-Flier, Eleftheria

    2014-01-01

    Objective Fibroblast growth factor 21 (FGF21) is a hormone with pleiotropic metabolic activities which, in rodents, is robustly regulated by fasting and ketogenic diets. In contrast, similar dietary interventions have either no or minimal effects on circulating FGF21 in humans. Moreover, no intervention or dietary challenge has been shown to acutely stimulate circulating FGF21 in either humans or animals. Recent animal data suggest that the transcription factor Carbohydrate Responsive-Element...

  13. Human reproductive system disturbances and pesticide exposure in Brazil

    OpenAIRE

    Sergio Koifman; Rosalina Jorge Koifman; Armando Meyer

    2002-01-01

    The observation of reproductive disturbances in humans and in the wildlife has been reported in the last decade in different countries. Exposure to different chemicals possibly acting in the endocrine system or endocrine disruptors, including pesticides, has been a hypothesis raised to explain the observed changes. This paper aimed to present results of an epidemiological ecologic study carried out to explore population data on pesticides exposure in selected Brazilian states in the eighties ...

  14. Developing human health exposure scenarios for petroleum substances under REACH

    Energy Technology Data Exchange (ETDEWEB)

    Carter, M.; De Wilde, P.; Maksimainen, K.; Margary, A.; Money, C.; Pizzella, G.; Svanehav, T.; Tsang, W.; Urbanus, J.; Rohde, A.

    2012-12-15

    This report describes the approaches that were adopted by CONCAWE to prepare the human exposure estimates in the chemical safety assessments of the REACH registration dossiers for petroleum substances based on all applicable regulatory guidance. Separate exposure estimates were developed for workers and for consumers and included inhalation and dermal routes. The complex nature of petroleum substances required various scientifically justified refinements of the regulatory guidance.

  15. Human responses to carbon dioxide, a follow-up study at recommended exposure limits in non-industrial environments

    DEFF Research Database (Denmark)

    Zhang, Xiaojing; Wargocki, Pawel; Lian, Zhiwei

    2016-01-01

    To extend the results of a previous study on the effects of carbon dioxide (CO2) and bioeffluents on humans, the new study reported in this paper was carried out. The purpose of this study was to examine, whether exposure to CO2 at 5000 ppm would cause sensory discomfort, evoke acute health...... was added to the supply air to create an exposure condition with CO2 at 5000 ppm (the measured exposure level was ca. 4900 ppm). Ten healthy college-age students were exposed twice to each of the two conditions for 2.5 h in a design balanced for order of presentation. The raised CO2 concentration had...

  16. Human exposure to organic arsenic species from seafood.

    Science.gov (United States)

    Taylor, Vivien; Goodale, Britton; Raab, Andrea; Schwerdtle, Tanja; Reimer, Ken; Conklin, Sean; Karagas, Margaret R; Francesconi, Kevin A

    2017-02-15

    Seafood, including finfish, shellfish, and seaweed, is the largest contributor to arsenic (As) exposure in many human populations. In contrast to the predominance of inorganic As in water and many terrestrial foods, As in marine-derived foods is present primarily in the form of organic compounds. To date, human exposure and toxicological assessments have focused on inorganic As, while organic As has generally been considered to be non-toxic. However, the high concentrations of organic As in seafood, as well as the often complex As speciation, can lead to complications in assessing As exposure from diet. In this report, we evaluate the presence and distribution of organic As species in seafood, and combined with consumption data, address the current capabilities and needs for determining human exposure to these compounds. The analytical approaches and shortcomings for assessing these compounds are reviewed, with a focus on the best practices for characterization and quantitation. Metabolic pathways and toxicology of two important classes of organic arsenicals, arsenolipids and arsenosugars, are examined, as well as individual variability in absorption of these compounds. Although determining health outcomes or assessing a need for regulatory policies for organic As exposure is premature, the extensive consumption of seafood globally, along with the preliminary toxicological profiles of these compounds and their confounding effect on assessing exposure to inorganic As, suggests further investigations and process-level studies on organic As are needed to fill the current gaps in knowledge.

  17. Acute Respiratory Failure due to Alveolar Hemorrhage after Exposure to Organic Dust

    Directory of Open Access Journals (Sweden)

    Sun Mi Choi

    2016-05-01

    Full Text Available Diffuse alveolar hemorrhage (DAH is associated with severe outcomes. We report a case of acute respiratory failure that required mechanical ventilation and was clinically and pathologically diagnosed as DAH related to exposure to organic dust. A 39-year-old man, who had visited a warehouse to grade beans for purchase, was referred to our hospital for impending respiratory failure. His initial radiographic examinations revealed diffuse bilateral ground-glass opacities in his lungs and bronchoalveolar lavage resulted in progressively bloodier returns, which is characteristic of DAH. He underwent bedside open lung biopsy of his right lower lobe in the intensive care unit. Biopsy results revealed DAH and organization with accumulation of hemosiderin-laden macrophages and a few fibroblastic foci. The patient was treated with empirical antibiotics and high-dose corticosteroids and successfully weaned from mechanical ventilation. DAH might be considered in the differential diagnosis of patients with acute respiratory failure after exposure to organic particles.

  18. Human exposure to endocrine disruptors and breast milk.

    Science.gov (United States)

    Stefanidou, M; Maravelias, C; Spiliopoulou, C

    2009-09-01

    Endocrine system is one of the most sensitive communication networks of the human body which influences all aspects of human health and well-being, including reproductive potential, cognitive functions, thyroid and metabolism, digestion and hormonal balance. In recent years basic laboratory research has been focused on the potential relationship between environmental contaminants and cellular endocrine function. Environmental contaminants are ubiquitous in the environment, alter endocrine physiology and produce endocrine disruption without acting as classic toxicants. These endocrine disruptors (EDCs) are lipophilic and stored for long periods of time in the adipose tissue. Maternal exposure to EDCs during pregnancy and lactation has as a result the exposure of the fetus and neonate through placenta and breast milk. It has been recognized that human milk is the best natural food for neonates providing immunologic, developmental and practical advantages throughout childhood. However, contamination of human milk by the presence of environmental toxicants is widespread through the past decades due to inadequately controlled pollution. Persistent pesticides, chemical solvents and others tend to invade slowly the environment, to bioaccumulate in the food chain and to have long half-lives in animals and humans. During the past fifteen years, the scientific interest has been focused on xenoestrogens, i.e.,environmental chemicals with estrogen disrupting activity. Certain adverse health and reproductive outcomes are attributed to these chemicals in wildlife, in laboratory animals, as well as in humans. Although most toxic agents are hazardous in high doses, the human health risks associated with EDCs concern exposure to low doses. The human health risks that may be associated with these low-level but constant exposures are still largely unknown and highly controversial. In this paper, we review available data on environmental chemicals present in breast milk that may

  19. Acute and chronic toxicity of sodium sulfate to four freshwater organisms in water-only exposures.

    Science.gov (United States)

    Wang, Ning; Dorman, Rebecca A; Ingersoll, Christopher G; Hardesty, Doug K; Brumbaugh, William G; Hammer, Edward J; Bauer, Candice R; Mount, David R

    2016-01-01

    The acute and chronic toxicity of sulfate (tested as sodium sulfate) was determined in diluted well water (hardness of 100 mg/L and pH 8.2) with a cladoceran (Ceriodaphnia dubia; 2-d and 7-d exposures), a midge (Chironomus dilutus; 4-d and 41-d exposures), a unionid mussel (pink mucket, Lampsilis abrupta; 4-d and 28-d exposures), and a fish (fathead minnow, Pimephales promelas; 4-d and 34-d exposures). Among the 4 species, the cladoceran and mussel were acutely more sensitive to sulfate than the midge and fathead minnow, whereas the fathead minnow was chronically more sensitive than the other 3 species. Acute-to-chronic ratios ranged from 2.34 to 5.68 for the 3 invertebrates but were as high as 12.69 for the fish. The fathead minnow was highly sensitive to sulfate during the transitional period from embryo development to hatching in the diluted well water, and thus, additional short-term (7- to 14-d) sulfate toxicity tests were conducted starting with embryonic fathead minnow in test waters with different ionic compositions at a water hardness of 100 mg/L. Increasing chloride in test water from 10 mg Cl/L to 25 mg Cl/L did not influence sulfate toxicity to the fish, whereas increasing potassium in test water from 1 mg K/L to 3 mg K/L substantially reduced the toxicity of sulfate. The results indicate that both acute and chronic sulfate toxicity data, and the influence of potassium on sulfate toxicity to fish embryos, need to be considered when environmental guidance values for sulfate are developed or refined.

  20. Perspectives for integrating human and environmental exposure assessments.

    Science.gov (United States)

    Ciffroy, P; Péry, A R R; Roth, N

    2016-10-15

    Integrated Risk Assessment (IRA) has been defined by the EU FP7 HEROIC Coordination action as "the mutual exploitation of Environmental Risk Assessment for Human Health Risk Assessment and vice versa in order to coherently and more efficiently characterize an overall risk to humans and the environment for better informing the risk analysis process" (Wilks et al., 2015). Since exposure assessment and hazard characterization are the pillars of risk assessment, integrating Environmental Exposure assessment (EEA) and Human Exposure assessment (HEA) is a major component of an IRA framework. EEA and HEA typically pursue different targets, protection goals and timeframe. However, human and wildlife species also share the same environment and they similarly inhale air and ingest water and food through often similar overlapping pathways of exposure. Fate models used in EEA and HEA to predict the chemicals distribution among physical and biological media are essentially based on common properties of chemicals, and internal concentration estimations are largely based on inter-species (i.e. biota-to-human) extrapolations. Also, both EEA and HEA are challenged by increasing scientific complexity and resources constraints. Altogether, these points create the need for a better exploitation of all currently existing data, experimental approaches and modeling tools and it is assumed that a more integrated approach of both EEA and HEA may be part of the solution. Based on the outcome of an Expert Workshop on Extrapolations in Integrated Exposure Assessment organized by the HEROIC project in January 2014, this paper identifies perspectives and recommendations to better harmonize and extrapolate exposure assessment data, models and methods between Human Health and Environmental Risk Assessments to support the further development and promotion of the concept of IRA. Ultimately, these recommendations may feed into guidance showing when and how to apply IRA in the regulatory decision

  1. Exposure to acute stress enhances decision-making competence: Evidence for the role of DHEA.

    Science.gov (United States)

    Shields, Grant S; Lam, Jovian C W; Trainor, Brian C; Yonelinas, Andrew P

    2016-05-01

    Exposure to acute stress can impact performance on numerous cognitive abilities, but little is known about how acute stress affects real-world decision-making ability. In the present study, we induced acute stress with a standard laboratory task involving uncontrollable socio-evaluative stress and subsequently assessed decision-making ability using the Adult Decision Making Competence index. In addition, we took baseline and post-test saliva samples from participants to examine associations between decision-making competence and adrenal hormones. Participants in the stress induction group showed enhanced decision-making competence, relative to controls. Further, although both cortisol and dehydroepiandrosterone (DHEA) reactivity predicted decision-making competence when considered in isolation, DHEA was a significantly better predictor than cortisol when both hormones were considered simultaneously. Thus, our results show that exposure to acute stress can have beneficial effects on the cognitive ability underpinning real-world decision-making and that this effect relates to DHEA reactivity more than cortisol.

  2. Effects of Long-term Exposure to Hydrogen Sulfide on Human Red Blood Cells

    Directory of Open Access Journals (Sweden)

    A Saeedi

    2015-01-01

    Full Text Available Background: Hydrogen sulfide (H2S exhibits both physiological and toxicological roles in the biological systems. Acute exposure to high levels of H2S is life threatening while long-term exposure to ambient levels of H2S elicits human health effects. Objective: To study the harmful effects of long-term exposure to low levels of H2S on human blood cells. Methods: 110 adult workers from Iran who were occupationally exposed to 0–90 ppb H2S for 1–30 years were studied. The participants aged between 18 and 60 years and were exposed directly or indirectly to sulfur compounds (exposed group. The origin of H2S was natural gas processing plants. A control group consisting of 110 males who were not in contact with H2S was also studied. For all participants, hematological profile including total hemoglobin and red blood cell count and sulfhemoglobin, methemoglobin levels were measured. Results: Among all parameters evaluated in this study the mean methemoglobin and sulfhemoglobin levels were significantly higher among workers who were exposed to sulfur compounds than the control group. Major differences throughout the study period for sulfhemoglobinemia among exposed groups were observed. Conclusion: Long-term exposure to even low levels of H2S in workplaces may have potential harmful effects on human health.

  3. National Surveillance of Occupational Exposure to the Human Immunodeficiency Virus

    Directory of Open Access Journals (Sweden)

    Maura Ricketts

    1992-01-01

    Full Text Available In September 1985, a prospective study was initiated to monitor the occurrence of occupational exposures to human immunodeficiency virus (HIV-infected blood and body fluids in Canada. This program was coordinated by the Federal Centre for acquired immune deficiency syndrome (AIDS (now the Division of HIV/AIDS Epidemiology at the Laboratory Centre for Disease Control. The objective was to determine the risk to workers of acquiring HIV infection as a result of exposure to HIV-infected blood and other body fluids. To be eligible, a worker must have sustained a documented parenteral, mucous membrane or skin contact exposure to blood or body fluids from an HIV-infected person. A baseline specimen was collected within a week of the exposure and then at six weeks, 12 weeks, six months and 12 months. Information concerning the type of exposure, precautions used and post exposure treatment was submitted to the Federal Centre for AIDS on standard data collection forms. All information was anonymous, identified only by a code number. Guidelines for counselling an exposed employee were provided with enrollment material. As of July 29, 1991, 414 employees have been included in the study. Two hundred and thirty-seven of the 414 exposures (57% were needlestick injuries of which 167 (70% were sustained by nurses. Other exposures consisted of open wound contamination, eye splashes, scalpel wounds and skin contact with blood and body fluids. To date, there have been no seroconversions among workers enrolled in the surveillance program.

  4. Disrupted Nitric Oxide Metabolism from Type II Diabetes and Acute Exposure to Particulate Air Pollution.

    Directory of Open Access Journals (Sweden)

    Ashley P Pettit

    Full Text Available Type II diabetes is an established cause of vascular impairment. Particulate air pollution is known to exacerbate cardiovascular and respiratory conditions, particularly in susceptible populations. This study set out to determine the impact of exposure to traffic pollution, with and without particle filtration, on vascular endothelial function in Type II diabetes. Endothelial production of nitric oxide (NO has previously been linked to vascular health. Reactive hyperemia induces a significant increase in plasma nitrite, the proximal metabolite of NO, in healthy subjects, while diabetics have a lower and more variable level of response. Twenty type II diabetics and 20 controls (ages 46-70 years were taken on a 1.5 hr roadway traffic air pollution exposure as passengers. We analyzed plasma nitrite, as a measure of vascular function, using forearm ischemia to elicit a reactive hyperemic response before and after exposure to one ride with and one without filtration of the particle components of pollution. Control subjects displayed a significant increase in plasma nitrite levels during reactive hyperemia. This response was no longer present following exposure to traffic air pollution, but did not vary with whether or not the particle phase was filtered out. Diabetics did not display an increase in nitrite levels following reactive hyperemia. This response was not altered following pollution exposure. These data suggest that components of acute traffic pollution exposure diminish vascular reactivity in non-diabetic individuals. It also confirms that type II diabetics have a preexisting diminished ability to appropriately respond to a vascular challenge, and that traffic pollution exposure does not cause a further measureable acute change in plasma nitrite levels in Type II diabetics.

  5. Controlled human exposures to ambient pollutant particles in susceptible populations

    Directory of Open Access Journals (Sweden)

    Ghio Andrew J

    2009-07-01

    Full Text Available Abstract Epidemiologic studies have established an association between exposures to air pollution particles and human mortality and morbidity at concentrations of particles currently found in major metropolitan areas. The adverse effects of pollution particles are most prominent in susceptible subjects, including the elderly and patients with cardiopulmonary diseases. Controlled human exposure studies have been used to confirm the causal relationship between pollution particle exposure and adverse health effects. Earlier studies enrolled mostly young healthy subjects and have largely confirmed the capability of particles to cause adverse health effects shown in epidemiological studies. In the last few years, more studies involving susceptible populations have been published. These recent studies in susceptible populations, however, have shown that the adverse responses to particles appear diminished in these susceptible subjects compared to those in healthy subjects. The present paper reviewed and compared control human exposure studies to particles and sought to explain the "unexpected" response to particle exposure in these susceptible populations and make recommendations for future studies. We found that the causes for the discrepant results are likely multifactorial. Factors such as medications, the disease itself, genetic susceptibility, subject selection bias that is intrinsic to many controlled exposure studies and nonspecificity of study endpoints may explain part of the results. Future controlled exposure studies should select endpoints that are more closely related to the pathogenesis of the disease and reflect the severity of particle-induced health effects in the specific populations under investigation. Future studies should also attempt to control for medications and genetic susceptibility. Using a different study design, such as exposing subjects to filtered air and ambient levels of particles, and assessing the improvement in

  6. Acute lead exposure increases arterial pressure: role of the renin-angiotensin system.

    Directory of Open Access Journals (Sweden)

    Maylla Ronacher Simões

    Full Text Available BACKGROUND: Chronic lead exposure causes hypertension and cardiovascular disease. Our purpose was to evaluate the effects of acute exposure to lead on arterial pressure and elucidate the early mechanisms involved in the development of lead-induced hypertension. METHODOLOGY/PRINCIPAL FINDINGS: Wistar rats were treated with lead acetate (i.v. bolus dose of 320 µg/Kg, and systolic arterial pressure, diastolic arterial pressure and heart rate were measured during 120 min. An increase in arterial pressure was found, and potential roles of the renin-angiotensin system, Na(+,K(+-ATPase and the autonomic reflexes in this change in the increase of arterial pressure found were evaluated. In anesthetized rats, lead exposure: 1 produced blood lead levels of 37±1.7 µg/dL, which is below the reference blood concentration (60 µg/dL; 2 increased systolic arterial pressure (Ct: 109±3 mmHg vs Pb: 120±4 mmHg; 3 increased ACE activity (27% compared to Ct and Na(+,K(+-ATPase activity (125% compared to Ct; and 4 did not change the protein expression of the α1-subunit of Na(+,K(+-ATPase, AT(1 and AT(2. Pre-treatment with an AT(1 receptor blocker (losartan, 10 mg/Kg or an ACE inhibitor (enalapril, 5 mg/Kg blocked the lead-induced increase of arterial pressure. However, a ganglionic blockade (hexamethonium, 20 mg/Kg did not prevent lead's hypertensive effect. CONCLUSION: Acute exposure to lead below the reference blood concentration increases systolic arterial pressure by increasing angiotensin II levels due to ACE activation. These findings offer further evidence that acute exposure to lead can trigger early mechanisms of hypertension development and might be an environmental risk factor for cardiovascular disease.

  7. The effects of acute stress exposure on neural correlates of Pavlovian conditioning with monetary gains and losses

    Directory of Open Access Journals (Sweden)

    Andrea H Lewis

    2014-05-01

    Full Text Available Pavlovian conditioning involves the association of an inherently neutral stimulus with an appetitive or aversive outcome, such that the neutral stimulus itself acquires reinforcing properties. Across species, this type of learning has been shown to involve subcortical brain regions such as the striatum and the amygdala. It is less clear, however, how the neural circuitry involved in the acquisition of Pavlovian contingencies in humans is affected by acute stress. In the current study, we investigate the effect of acute stress exposure on Pavlovian conditioning using monetary reinforcers. Participants underwent a partial reinforcement conditioning procedure in which neutral stimuli were paired with high and low magnitude monetary gains and losses. A between-subjects design was used, such that half of the participants were exposed to cold stress while the remaining participants were exposed to a no stress control procedure. Cortisol measurements and subjective ratings were used as measures of stress. We observed an interaction between stress, valence and magnitude in the ventral striatum, with the peak in the putamen. More specifically, the stress group exhibited an increased sensitivity to magnitude in the gain domain. This effect was driven by those participants who experienced a larger increase in circulating cortisol levels in response to the stress manipulation. Taken together, these results suggest that acute stress can lead to individual differences in circulating cortisol levels which influence brain regions involved in associative learning such as the ventral striatum.

  8. The effects of acute stress exposure on striatal activity during Pavlovian conditioning with monetary gains and losses.

    Science.gov (United States)

    Lewis, Andrea H; Porcelli, Anthony J; Delgado, Mauricio R

    2014-01-01

    Pavlovian conditioning involves the association of an inherently neutral stimulus with an appetitive or aversive outcome, such that the neutral stimulus itself acquires reinforcing properties. Across species, this type of learning has been shown to involve subcortical brain regions such as the striatum and the amygdala. It is less clear, however, how the neural circuitry involved in the acquisition of Pavlovian contingencies in humans, particularly in the striatum, is affected by acute stress. In the current study, we investigate the effect of acute stress exposure on Pavlovian conditioning using monetary reinforcers. Participants underwent a partial reinforcement conditioning procedure in which neutral stimuli were paired with high and low magnitude monetary gains and losses. A between-subjects design was used, such that half of the participants were exposed to cold stress while the remaining participants were exposed to a no stress control procedure. Cortisol measurements and subjective ratings were used as measures of stress. We observed an interaction between stress, valence, and magnitude in the ventral striatum, with the peak in the putamen. More specifically, the stress group exhibited an increased sensitivity to magnitude in the gain domain. This effect was driven by those participants who experienced a larger increase in circulating cortisol levels in response to the stress manipulation. Taken together, these results suggest that acute stress can lead to individual differences in circulating cortisol levels which influence the striatum during Pavlovian conditioning with monetary reinforcers.

  9. Integrating population dynamics into mapping human exposure to seismic hazard

    Directory of Open Access Journals (Sweden)

    S. Freire

    2012-11-01

    Full Text Available Disaster risk is not fully characterized without taking into account vulnerability and population exposure. Assessment of earthquake risk in urban areas would benefit from considering the variation of population distribution at more detailed spatial and temporal scales, and from a more explicit integration of this improved demographic data with existing seismic hazard maps. In the present work, "intelligent" dasymetric mapping is used to model population dynamics at high spatial resolution in order to benefit the analysis of spatio-temporal exposure to earthquake hazard in a metropolitan area. These night- and daytime-specific population densities are then classified and combined with seismic intensity levels to derive new spatially-explicit four-class-composite maps of human exposure. The presented approach enables a more thorough assessment of population exposure to earthquake hazard. Results show that there are significantly more people potentially at risk in the daytime period, demonstrating the shifting nature of population exposure in the daily cycle and the need to move beyond conventional residence-based demographic data sources to improve risk analyses. The proposed fine-scale maps of human exposure to seismic intensity are mainly aimed at benefiting visualization and communication of earthquake risk, but can be valuable in all phases of the disaster management process where knowledge of population densities is relevant for decision-making.

  10. Acute and chronic ethanol exposure differentially alters alcohol dehydrogenase and aldehyde dehydrogenase activity in the zebrafish liver.

    Science.gov (United States)

    Tran, Steven; Nowicki, Magda; Chatterjee, Diptendu; Gerlai, Robert

    2015-01-02

    Chronic ethanol exposure paradigms have been successfully used in the past to induce behavioral and central nervous system related changes in zebrafish. However, it is currently unknown whether chronic ethanol exposure alters ethanol metabolism in adult zebrafish. In the current study we examine the effect of acute ethanol exposure on adult zebrafish behavioral responses, as well as alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activity in the liver. We then examine how two different chronic ethanol exposure paradigms (continuous and repeated ethanol exposure) alter behavioral responses and liver enzyme activity during a subsequent acute ethanol challenge. Acute ethanol exposure increased locomotor activity in a dose-dependent manner. ADH activity was shown to exhibit an inverted U-shaped curve and ALDH activity was decreased by ethanol exposure at all doses. During the acute ethanol challenge, animals that were continuously housed in ethanol exhibited a significantly reduced locomotor response and increased ADH activity, however, ALDH activity did not change. Zebrafish that were repeatedly exposed to ethanol demonstrated a small but significant attenuation of the locomotor response during the acute ethanol challenge but ADH and ALDH activity was similar to controls. Overall, we identified two different chronic ethanol exposure paradigms that differentially alter behavioral and physiological responses in zebrafish. We speculate that these two paradigms may allow dissociation of central nervous system-related and liver enzyme-dependent ethanol induced changes in zebrafish. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Human disease resulting from exposure to electromagnetic fields.

    Science.gov (United States)

    Carpenter, David O

    2013-01-01

    Electromagnetic fields (EMFs) include everything from cosmic rays through visible light to the electric and magnetic fields associated with electricity. While the high frequency fields have sufficient energy to cause cancer, the question of whether there are human health hazards associated with communication radiofrequency (RF) EMFs and those associated with use of electricity remains controversial. The issue is more important than ever given the rapid increase in the use of cell phones and other wireless devices. This review summarizes the evidence stating that excessive exposure to magnetic fields from power lines and other sources of electric current increases the risk of development of some cancers and neurodegenerative diseases, and that excessive exposure to RF radiation increases risk of cancer, male infertility, and neurobehavioral abnormalities. The relative impact of various sources of exposure, the great range of standards for EMF exposure, and the costs of doing nothing are also discussed.

  12. Human convective boundary layer and its impact on personal exposure

    DEFF Research Database (Denmark)

    Licina, Dusan

    People spend most of their time indoors and they are constantly exposed to pollution that affects their health, comfort and productivity. Due to strong economic and environmental pressures to reduce building energy consumption, low air velocity design is gaining popularity; hence buoyancy flows...... differences in pollution concentration mean that personal exposure, rather than average space concentration, determines the risk of elevated exposure. Current room air distribution design practice does not take into account the air movement induced by the thermal flows from occupants, which often results...... in inaccurate exposure prediction. This highlights the importance of a detailed understanding of the complex air movements that take place in the vicinity of the human body and their impact on personal exposure. The two objectives of the present work are: (i) to examine the extent to which the room air...

  13. Human reproductive system disturbances and pesticide exposure in Brazil

    Directory of Open Access Journals (Sweden)

    Koifman Sergio

    2002-01-01

    Full Text Available The observation of reproductive disturbances in humans and in the wildlife has been reported in the last decade in different countries. Exposure to different chemicals possibly acting in the endocrine system or endocrine disruptors, including pesticides, has been a hypothesis raised to explain the observed changes. This paper aimed to present results of an epidemiological ecologic study carried out to explore population data on pesticides exposure in selected Brazilian states in the eighties and human reproductive outcomes in the nineties. Pearson correlation coefficients were ascertained between available data pesticides sales in eleven states in Brazil in 1985 and selected further reproductive outcomes or their surrogates. Moderate to high correlations were observed to infertility, testis, breast, prostate and ovarian cancer mortality. Despite the restrains of ecologic studies to establish cause-effect relationships, the observed results are in agreement with evidence supporting a possible association between pesticides exposure and the analyzed reproductive outcomes.

  14. Assessing Sources of Human Methylmercury Exposure Using Stable Mercury Isotopes

    DEFF Research Database (Denmark)

    Li, Miling; Sherman, Laura S; Blum, Joel D

    2014-01-01

    Seafood consumption is the primary route of methylmercury (MeHg) exposure for most populations. Inherent uncertainties in dietary survey data point to the need for an empirical tool to confirm exposure sources. We therefore explore the utility of Hg stable isotope ratios in human hair as a new...... method for discerning MeHg exposure sources. We characterized Hg isotope fractionation between humans and their diets using hair samples from Faroese whalers exposed to MeHg predominantly from pilot whales. We observed an increase of 1.75‰ in δ(202)Hg values between pilot whale muscle tissue and Faroese...... whalers' hair but no mass-independent fractionation. We found a similar offset in δ(202)Hg between consumed seafood and hair samples from Gulf of Mexico recreational anglers who are exposed to lower levels of MeHg from a variety of seafood sources. An isotope mixing model was used to estimate individual...

  15. Traditional goat husbandry may substantially contribute to human toxoplasmosis exposure

    Science.gov (United States)

    Raising goats in settings that are highly contaminated with oocysts of Toxoplasma gondii may contribute significantly to human exposure to this zoonotic parasite. Increasing consumption of young goats in Romania, where goats are typically reared in backyards that are also home to cats (the definitiv...

  16. Biocides Steering Group on human exposure assessment: A preliminary report

    NARCIS (Netherlands)

    Hemmen, J.J. van

    1999-01-01

    In a project granted by DG XI of the European Commission, it is attempted to collate experimental and theoretical data on human (workers and consumers) exposure assessment to biocidal products, and to outline the methodology for sampling and measurement. On the basis of the available evidence, appro

  17. Effect of riluzole on acute pain and hyperalgesia in humans

    DEFF Research Database (Denmark)

    Hammer, N A; Lillesø, J; Pedersen, J L;

    1999-01-01

    Riluzole modulates several transmitter systems which may be involved in nociception. Antinociceptive effects have been shown in animal studies, but there are no human data. Therefore, we have examined the acute analgesic effect of riluzole in a human model of inflammatory pain induced by a thermal...... injury on the distal leg (47 degrees C, 7 min, 12.5 cm2) in 20 healthy volunteers. Hyperalgesia to mechanical and heat stimuli were examined by von Frey hairs and thermodes. We used a randomized, double-blind, placebo-controlled design, and subjects received riluzole 100 mg or placebo for 2 days...... with a 14-day interval. The burns produced significant hyperalgesia, but riluzole had no acute analgesic effects in normal or hyperalgesic skin....

  18. Chromosomal bands affected by acute oil exposure and DNA repair errors.

    Directory of Open Access Journals (Sweden)

    Gemma Monyarch

    Full Text Available BACKGROUND: In a previous study, we showed that individuals who had participated in oil clean-up tasks after the wreckage of the Prestige presented an increase of structural chromosomal alterations two years after the acute exposure had occurred. Other studies have also reported the presence of DNA damage during acute oil exposure, but little is known about the long term persistence of chromosomal alterations, which can be considered as a marker of cancer risk. OBJECTIVES: We analyzed whether the breakpoints involved in chromosomal damage can help to assess the risk of cancer as well as to investigate their possible association with DNA repair efficiency. METHODS: Cytogenetic analyses were carried out on the same individuals of our previous study and DNA repair errors were assessed in cultures with aphidicolin. RESULTS: Three chromosomal bands, 2q21, 3q27 and 5q31, were most affected by acute oil exposure. The dysfunction in DNA repair mechanisms, expressed as chromosomal damage, was significantly higher in exposed-oil participants than in those not exposed (p= 0.016. CONCLUSION: The present study shows that breaks in 2q21, 3q27 and 5q31 chromosomal bands, which are commonly involved in hematological cancer, could be considered useful genotoxic oil biomarkers. Moreover, breakages in these bands could induce chromosomal instability, which can explain the increased risk of cancer (leukemia and lymphomas reported in chronically benzene-exposed individuals. In addition, it has been determined that the individuals who participated in clean-up of the oil spill presented an alteration of their DNA repair mechanisms two years after exposure.

  19. Assessment of human exposure effects of nitrous acid

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, T.R.; Kjaergaard, S.K. (University of Aarhus. Institute of Environmental and Occupational Medicine (Denmark)); Brauer, M. (Harvard School of Public Health. Department of Environmental Health, Exposure Assessment and Engineering Program (United States))

    1993-01-01

    The study aimed at an estimation of the relative contribution of nitrous acid to measurable human exposure effects in relation to indoor environments with unvented gas combustion. Fifteen medically examined totally healthy non-smoker adults aged between 22 and 57 years were exposed in a double-blind, balanced design (3x3 latin square) to clean air and nitrous acid (HONO) concentration in an empty 74 m[sup 3] climate chamber. 3 teams of 5 subjects each were randomly exposed and the latin square was selected at random. Each exposure period was 3.5 hours and preceded by a 1 hour base-line pre-exposure measurement period. After 1 hr 40 minutes the subjects exercised for ten minutes on bicycle ergometers in order to increase the uptake of HONO by increasing ventilatory rate 3-4 fold. Workloads were calculated individually and ranged from 21800-34600 kpm/h. During the 10 minutes the test subjects were mouth-breathing to encourage deeper penetration of nitrous acid in the respiratory system so as to induce a mild cooling which would increase their responsiveness to irritants. The amount of deliverable H[sup +] was estimated at 16.350 nmoles with exposure to 395 ppb HONO with subjects breathing at the rate of 5 L min[sup -1]. It was assumed that HONO is efficiently absorbed into the respiratory system. Details are given of the results. Findings were highly variable, largely negative effects of exposure to nitrous acid which appear similiar to results seen in nitrogen dioxide exposure studies. It is concluded to be unlikely that HONO exposures alone can be responsible for exposure misclassification in NO[sub 2] exposure studies. (AB) (52 refs.).

  20. Assessment of human exposure effects of nitrous acid

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, T.R.; Kjaergaard, S.K. [University of Aarhus. Institute of Environmental and Occupational Medicine (Denmark); Brauer, M. [Harvard School of Public Health. Department of Environmental Health, Exposure Assessment and Engineering Program (United States)

    1993-01-01

    The study aimed at an estimation of the relative contribution of nitrous acid to measurable human exposure effects in relation to indoor environments with unvented gas combustion. Fifteen medically examined totally healthy non-smoker adults aged between 22 and 57 years were exposed in a double-blind, balanced design (3x3 latin square) to clean air and nitrous acid (HONO) concentration in an empty 74 m{sup 3} climate chamber. 3 teams of 5 subjects each were randomly exposed and the latin square was selected at random. Each exposure period was 3.5 hours and preceded by a 1 hour base-line pre-exposure measurement period. After 1 hr 40 minutes the subjects exercised for ten minutes on bicycle ergometers in order to increase the uptake of HONO by increasing ventilatory rate 3-4 fold. Workloads were calculated individually and ranged from 21800-34600 kpm/h. During the 10 minutes the test subjects were mouth-breathing to encourage deeper penetration of nitrous acid in the respiratory system so as to induce a mild cooling which would increase their responsiveness to irritants. The amount of deliverable H{sup +} was estimated at 16.350 nmoles with exposure to 395 ppb HONO with subjects breathing at the rate of 5 L min{sup -1}. It was assumed that HONO is efficiently absorbed into the respiratory system. Details are given of the results. Findings were highly variable, largely negative effects of exposure to nitrous acid which appear similiar to results seen in nitrogen dioxide exposure studies. It is concluded to be unlikely that HONO exposures alone can be responsible for exposure misclassification in NO{sub 2} exposure studies. (AB) (52 refs.).

  1. Development of Toxicological Risk Assessment Models for Acute and Chronic Exposure to Pollutants

    Directory of Open Access Journals (Sweden)

    Elke S. Reichwaldt

    2016-08-01

    Full Text Available Alert level frameworks advise agencies on a sequence of monitoring and management actions, and are implemented so as to reduce the risk of the public coming into contact with hazardous substances. Their effectiveness relies on the detection of the hazard, but with many systems not receiving any regular monitoring, pollution events often go undetected. We developed toxicological risk assessment models for acute and chronic exposure to pollutants that incorporate the probabilities that the public will come into contact with undetected pollution events, to identify the level of risk a system poses in regards to the pollutant. As a proof of concept, we successfully demonstrated that the models could be applied to determine probabilities of acute and chronic illness types related to recreational activities in waterbodies containing cyanotoxins. Using the acute model, we identified lakes that present a ‘high’ risk to develop Day Away From Work illness, and lakes that present a ‘low’ or ‘medium’ risk to develop First Aid Cases when used for swimming. The developed risk models succeeded in categorising lakes according to their risk level to the public in an objective way. Modelling by how much the probability of public exposure has to decrease to lower the risks to acceptable levels will enable authorities to identify suitable control measures and monitoring strategies. We suggest broadening the application of these models to other contaminants.

  2. Lycopene Pretreatment Ameliorates Acute Ethanol Induced NAD+ Depletion in Human Astroglial Cells

    Directory of Open Access Journals (Sweden)

    Jade Guest

    2015-01-01

    Full Text Available Excessive alcohol consumption is associated with reduced brain volume and cognition. While the mechanisms by which ethanol induces these deleterious effects in vivo are varied most are associated with increased inflammatory and oxidative processes. In order to further characterise the effect of acute ethanol exposure on oxidative damage and NAD+ levels in the brain, human U251 astroglioma cells were exposed to physiologically relevant doses of ethanol (11 mM, 22 mM, 65 mM, and 100 mM for ≤ 30 minutes. Ethanol exposure resulted in a dose dependent increase in both ROS and poly(ADP-ribose polymer production. Significant decreases in total NAD(H and sirtuin 1 activity were also observed at concentrations ≥ 22 mM. Similar to U251 cells, exposure to ethanol (≥22 mM decreased levels of NAD(H in primary human astrocytes. NAD(H depletion in primary astrocytes was prevented by pretreatment with 1 μM of lycopene for 3.5 hours. Unexpectedly, in U251 cells lycopene treatment at concentrations ≥ 5 μM resulted in significant reductions in [NAD(H]. This study suggests that exposure of the brain to alcohol at commonly observed blood concentrations may cause transitory oxidative damage which may be at least partly ameliorated by lycopene.

  3. Mathematical Models of Human Hematopoiesis Following Acute Radiation Exposure

    Science.gov (United States)

    2014-05-01

    the model predicts. Radiation dose from skin contamination can result in cutaneous injury leading to systemic responses and may im- pact the observed...medical and performance consequences from radiation and combined injuries , thereby enhancing our understanding of the potential impact of a nuclear...subsequently. In addition to the insight gained from combined injury modeling, the models of hematopoiesis and radiation alone provide clini- cally

  4. Acute toxicity resulting from human exposures to military smokes

    NARCIS (Netherlands)

    Hulst, M. van; Langenberg, J.P.; Klerk, W.P.C. de; Alblas, M.J.

    2017-01-01

    The toxicity of smoke-generating ammunition can be established by looking at the complete hand grenade or only at the smoke composition. In this paper both approaches are described. The toxicity of a signalling smoke was assessed as a complete smoke hand grenade whereas for a 76 mm screening smoke

  5. Human Rabies with Initial Manifestations that Mimic Acute Brachial Neuritis and Guillain-Barré Syndrome.

    Science.gov (United States)

    Mader, Edward C; Maury, Joaquin S; Santana-Gould, Lenay; Craver, Randall D; El-Abassi, Rima; Segura-Palacios, Enrique; Sumner, Austin J

    2012-01-01

    Human rabies can be overlooked in places where this disease is now rare. Its diagnosis is further confused by a negative history of exposure (cryptogenic rabies), by a Guillain-Barré syndrome (GBS) type of presentation, or by symptoms indicating another diagnosis, eg, acute brachial neuritis (ABN). A 19-year-old Mexican, with no past health problems, presented with a two-day history of left shoulder, arm, and chest pain. He arrived in Louisiana from Mexico five days prior to admission. Of particular importance is the absence of a history of rabies exposure and immunization. On admission, the patient had quadriparesis, areflexia, and elevated protein in the cerebrospinal fluid, prompting a diagnosis of GBS. However, emerging neurological deficits pointed towards acute encephalitis. Rabies was suspected on hospital day 11 after common causes of encephalitis (eg, arboviruses) have been excluded. The patient tested positive for rabies IgM and IgG. He died 17 days after admission. Negri bodies were detected in the patient's brain and rabies virus antigen typing identified the vampire bat as the source of infection. Rabies should be suspected in every patient with a rapidly evolving GBS-like illness-even if there is no history of exposure and no evidence of encephalitis on presentation. The patient's ABN-like symptoms may be equivalent to the pain experienced by rabies victims near the inoculation site.

  6. Three dimensional visualisation of human facial exposure to solar ultraviolet.

    Science.gov (United States)

    Downs, Nathan; Parisi, Alfio

    2007-01-01

    A three dimensional computer model of the human face has been developed to represent solar ultraviolet exposures recorded by dosimeter measurements on a manikin headform under low cloud conditions and various solar zenith angles. Additionally, polysulfone dosimeters have been successfully miniaturised to provide the detailed measurements required across the face. The headform used in this research was scanned at 709 individual locations to make a wireframe mesh consisting of 18 vertical contours and 49 horizontal contours covering half the manikin's frontal facial topography. Additionally, the back of the headform and neck have also been scanned at 576 locations. Each scanned location has been used as a viable dosimeter position on the headform and represents a grid intersection point on the developed computer wireframe. A series of exposures recorded by dosimeters have been translated into three dimensional exposure ratio maps, representing ambient solar ultraviolet exposure. High dosimeter density has allowed for the development of individual topographic contour models which take into account complex variation in the face and improve upon previously employed techniques which utilise fewer dosimeters to interpolate exposure across facial contours. Exposure ratios for solar zenith angle ranges of 0 degrees -30 degrees, 30 degrees -50 degrees, and 50 degrees -80 degrees have been developed.

  7. Asbestos exposure increases human bronchial epithelial cell fibrinolytic activity.

    Science.gov (United States)

    Gross, T J; Cobb, S M; Gruenert, D C; Peterson, M W

    1993-03-01

    Chronic exposure to asbestos fibers results in fibrotic lung disease. The distal pulmonary epithelium is an early target of asbestos-mediated injury. Local plasmin activity may be important in modulating endoluminal inflammatory responses in the lung. We studied the effects of asbestos exposure on cell-mediated plasma clot lysis as a marker of pericellular plasminogen activation. Exposing human bronchial epithelial (HBE) cells to 100 micrograms/ml of asbestos fibers for 24 h resulted in increased plasma clot lysis. Fibrinolytic activity was augmented in a dose-dependent fashion, was not due to secreted protease, and occurred only when there was direct contact between the plasma clot and the epithelial monolayer. Further analysis showed that asbestos exposure increased HBE cell-associated urokinase-type plasminogen activator (uPA) activity in a time-dependent manner. The increased cell-associated PA activity could be removed by acid washing. The increase in PA activity following asbestos exposure required new protein synthesis because it was abrogated by treatment with either cycloheximide or actinomycin D. Therefore, asbestos exposure increases epithelial-mediated fibrinolysis by augmenting expression of uPA activity at the cell surface by mechanisms that require new RNA and protein synthesis. These observations suggest a novel mechanism whereby exposure of the distal epithelium to inhaled particulates may result in a chronic inflammatory response that culminates in the development of fibrotic lung disease.

  8. Acute and chronic cadmium exposure promotes E-cadherin degradation in MCF7 breast cancer cells.

    Science.gov (United States)

    Ponce, Esmeralda; Louie, Maggie C; Sevigny, Mary B

    2015-10-01

    Cadmium is an environmental carcinogen that usually enters the body at minute concentrations through diet or cigarette smoke and bioaccumulates in soft tissues. In past studies, cadmium has been shown to contribute to the development of more aggressive cancer phenotypes including increased cell migration and invasion. This study aims to determine if cadmium exposure-both acute and chronic-contributes to breast cancer progression by interfering with the normal functional relationship between E-cadherin and β-catenin. An MCF7 breast cancer cell line (MCF7-Cd) chronically exposed to 10(-7)  M CdCl2 was previously developed and used as a model system to study chronic exposures, whereas parental MCF7 cells exposed to 10(-6)  M CdCl2 for short periods of time were used to study acute exposures. Cadmium exposure of MCF7 cells led to the degradation of the E-cadherin protein via the ubiquitination pathway. This resulted in fewer E-cadherin/β-catenin complexes and the relocation of active β-catenin to the nucleus, where it interacted with transcription factor TCF-4 to modulate gene expression. Interestingly, only cells chronically exposed to cadmium showed a significant decrease in the localization of β-catenin to the plasma membrane and an increased distance between cells. Our data suggest that cadmium exposure promotes breast cancer progression by (1) down-regulating E-cadherin, thus decreasing the number of E-cadherin/β-catenin adhesion complexes, and (2) enhancing the nuclear translocation of β-catenin to increase expression of cancer-promoting proteins (i.e., c-Jun and cyclin D1).

  9. Acute pulmonary toxicity following inhalation exposure to aerosolized VX in anesthetized rats.

    Science.gov (United States)

    Peng, Xinqi; Perkins, Michael W; Simons, Jannitt; Witriol, Alicia M; Rodriguez, Ashley M; Benjamin, Brittany M; Devorak, Jennifer; Sciuto, Alfred M

    2014-06-01

    This study evaluated acute toxicity and pulmonary injury in rats at 3, 6 and 24 h after an inhalation exposure to aerosolized O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX). Anesthetized male Sprague-Dawley rats (250-300 g) were incubated with a glass endotracheal tube and exposed to saline or VX (171, 343 and 514 mg×min/m³ or 0.2, 0.5 and 0.8 LCt₅₀, respectively) for 10 min. VX was delivered by a small animal ventilator at a volume of 2.5 ml × 70 breaths/minute. All VX-exposed animals experienced a significant loss in percentage body weight at 3, 6, and 24 h post-exposure. In comparison to controls, animals exposed to 514 mg×min/m³ of VX had significant increases in bronchoalveolar lavage (BAL) protein concentrations at 6 and 24 h post-exposure. Blood acetylcholinesterase (AChE) activity was inhibited dose dependently at each of the times points for all VX-exposed groups. AChE activity in lung homogenates was significantly inhibited in all VX-exposed groups at each time point. All VX-exposed animals assessed at 20 min and 3, 6 and 24 h post-exposure showed increases in lung resistance, which was prominent at 20 min and 3 h post-exposure. Histopathologic evaluation of lung tissue of the 514 mg×min/m³ VX-exposed animals at 3, 6 and 24 h indicated morphological changes, including perivascular inflammation, alveolar exudate and histiocytosis, alveolar septal inflammation and edema, alveolar epithelial necrosis, and bronchiolar inflammatory infiltrates, in comparison to controls. These results suggest that aerosolization of the highly toxic, persistent chemical warfare nerve agent VX results in acute pulmonary toxicity and lung injury in rats.

  10. Histopathological alterations of white seabass, Lates calcarifer, in acute and subchronic cadmium exposure

    Energy Technology Data Exchange (ETDEWEB)

    Thophon, S.; Kruatrachue, M.; Upatham, E.S.; Pokethitiyook, P.; Sahaphong, S.; Jaritkhuan, S

    2003-03-01

    White seabass responded differently to cadmium at chronic and subchronic levels. - Histopathological alterations to white seabass, Lates calcarifer aged 3 months in acute and subchronic cadmium exposure were studied by light and scanning electron microscopy. The 96-h LC{sub 50} values of cadmium to L. calcarifer was found to be 20.12{+-}0.61 mg/l and the maximum acceptable toxicant concentration (MATC) was 7.79 mg/l. Fish were exposed to 10 and 0.8 mg/l of Cd (as CdCl{sub 2}H{sub 2}O) for 96 h and 90 days, respectively. The study showed that gill lamellae and kidney tubules were the primary target organs for the acute toxic effect of cadmium while in the subchronic exposure, the toxic effect to gills was less than that of kidney and liver. Gill alterations included edema of the epithelial cells with the breakdown of pillar cell system, aneurisms with some ruptures, hypertrophy and hyperplasia of epithelial and chloride cells. The liver showed blood congestion in sinusoids and hydropic swelling of hepatocytes, vacuolation and dark granule accumulation. Lipid droplets and glycogen content were observed in hepatocytes at the second and third month of subchronic exposure. The kidney showed hydropic swelling of tubular cell vacuolation and numerous dark granule accumulation in many tubules. Tubular degeneration and necrosis were seen in some areas.

  11. Acute toxicity effects of Prunus avium fruit extract and selection of optimum dose against radiation exposure.

    Science.gov (United States)

    Sisodia, Rashmi; Sharma, K; Singh, Smita

    2009-01-01

    The objective of the study was to evaluate the acute toxicity of different doses of the methanolic extract of the fruit pulp of Prunus avium (family Rosaceae), which is used ethno-medicinally for the treatment of various diseases, and to find out the optimal dose of Prunus avium extract against 10 Gy gamma-radiation exposure. To test acute toxicity in mice, different doses of PAE (Prunus avium fruit extract) were given orally for 15 consecutive days, after which the animals were observed for another 15 days; the LD50/15 of the methanolic extract was calculated to be 4.947 gm/kg body weight (b.wt). In optimum dose selection against radiation exposure, oral administration of 450 mg/kg b.wt/d of PAE for 15 consecutive days before exposure to 10 Gy of gamma-radiation was found to afford maximum protection in terms of body weight and survivability of the mice in comparison to other doses.

  12. Temporal changes in rat liver gene expression after acute cadmium and chromium exposure.

    Directory of Open Access Journals (Sweden)

    Michael S Madejczyk

    Full Text Available U.S. Service Members and civilians are at risk of exposure to a variety of environmental health hazards throughout their normal duty activities and in industrial occupations. Metals are widely used in large quantities in a number of industrial processes and are a common environmental toxicant, which increases the possibility of being exposed at toxic levels. While metal toxicity has been widely studied, the exact mechanisms of toxicity remain unclear. In order to further elucidate these mechanisms and identify candidate biomarkers, rats were exposed via a single intraperitoneal injection to three concentrations of CdCl2 and Na(2Cr(2O(7, with livers harvested at 1, 3, or 7 days after exposure. Cd and Cr accumulated in the liver at 1 day post exposure. Cd levels remained elevated over the length of the experiment, while Cr levels declined. Metal exposures induced ROS, including hydroxyl radical (•OH, resulting in DNA strand breaks and lipid peroxidation. Interestingly, ROS and cellular damage appeared to increase with time post-exposure in both metals, despite declines in Cr levels. Differentially expressed genes were identified via microarray analysis. Both metals perturbed gene expression in pathways related to oxidative stress, metabolism, DNA damage, cell cycle, and inflammatory response. This work provides insight into the temporal effects and mechanistic pathways involved in acute metal intoxication, leading to the identification of candidate biomarkers.

  13. Temporal Changes in Rat Liver Gene Expression after Acute Cadmium and Chromium Exposure

    Science.gov (United States)

    Madejczyk, Michael S.; Baer, Christine E.; Dennis, William E.; Minarchick, Valerie C.; Leonard, Stephen S.; Jackson, David A.; Stallings, Jonathan D.; Lewis, John A.

    2015-01-01

    U.S. Service Members and civilians are at risk of exposure to a variety of environmental health hazards throughout their normal duty activities and in industrial occupations. Metals are widely used in large quantities in a number of industrial processes and are a common environmental toxicant, which increases the possibility of being exposed at toxic levels. While metal toxicity has been widely studied, the exact mechanisms of toxicity remain unclear. In order to further elucidate these mechanisms and identify candidate biomarkers, rats were exposed via a single intraperitoneal injection to three concentrations of CdCl2 and Na2Cr2O7, with livers harvested at 1, 3, or 7 days after exposure. Cd and Cr accumulated in the liver at 1 day post exposure. Cd levels remained elevated over the length of the experiment, while Cr levels declined. Metal exposures induced ROS, including hydroxyl radical (•OH), resulting in DNA strand breaks and lipid peroxidation. Interestingly, ROS and cellular damage appeared to increase with time post-exposure in both metals, despite declines in Cr levels. Differentially expressed genes were identified via microarray analysis. Both metals perturbed gene expression in pathways related to oxidative stress, metabolism, DNA damage, cell cycle, and inflammatory response. This work provides insight into the temporal effects and mechanistic pathways involved in acute metal intoxication, leading to the identification of candidate biomarkers. PMID:25993096

  14. Parabens as Urinary Biomarkers of Exposure in Humans

    Science.gov (United States)

    Ye, Xiaoyun; Bishop, Amber M.; Reidy, John A.; Needham, Larry L.; Calafat, Antonia M.

    2006-01-01

    Background Parabens appear frequently as antimicrobial preservatives in cosmetic products, in pharmaceuticals, and in food and beverage processing. In vivo and in vitro studies have revealed weak estrogenic activity of some parabens. Widespread use has raised concerns about the potential human health risks associated with paraben exposure. Objectives Assessing human exposure to parabens usually involves measuring in urine the conjugated or free species of parabens or their metabolites. In animals, parabens are mostly hydrolyzed to p-hydroxybenzoic acid and excreted in the urine as conjugates. Still, monitoring urinary concentrations of p-hydroxybenzoic acid is not necessarily the best way to assess exposure to parabens. p-Hydroxybenzoic acid is a nonspecific biomarker, and the varying estrogenic bioactivities of parabens require specific biomarkers. Therefore, we evaluated the use of free and conjugated parent parabens as new biomarkers for human exposure to these compounds. Results We measured the urinary concentrations of methyl, ethyl, n-propyl, butyl (n- and iso-), and benzyl parabens in a demographically diverse group of 100 anonymous adults. We detected methyl and n-propyl parabens at the highest median concentrations (43.9 ng/mL and 9.05 ng/mL, respectively) in nearly all (> 96%) of the samples. We also detected other parabens in more than half of the samples (ethyl, 58%; butyl, 69%). Most important, however, we found that parabens in urine appear predominantly in their conjugated forms. Conclusions The results, demonstrating the presence of urinary conjugates of parabens in humans, suggest that such conjugated parabens could be used as exposure biomarkers. Additionally, the fact that conjugates appear to be the main urinary products of parabens may be important for risk assessment. PMID:17185273

  15. Cholinesterase inhibition and depression of the photic after discharge of flash evoked potentials following acute or repeated exposures to a mixture of carbaryl and propoxur.

    Science.gov (United States)

    Mwanza, Jean-Claude; Lyke, Danielle F; Hertzberg, Richard C; Haber, Lynne; Kohrman-Vincent, Melissa; Li, Ruosha; Pan, Yi; Lyles, Robert H; Simmons, Jane Ellen; Macmillan, Denise K; Zehr, R Dan; Swank, Adam E; Herr, David W

    2012-06-01

    larger differences between the acute and repeated treatment paradigms, and showed slightly greater deviations from dose-additivity. Because these treatments utilized larger dosages than anticipated environmental exposures, concern for non-additive effects in humans is minimized. The small magnitude of the deviations from dose-additivity also suggest that in the absence of repeated exposure data, results from an acute study of readily reversible carbamate toxicity can be used to estimate the response to repeated daily exposures.

  16. Acute paraquat exposure impairs colonic motility by selectively attenuating nitrergic signalling in the mouse.

    Science.gov (United States)

    Diss, Lucy; Dyball, Sarah; Ghela, Tina; Golding, Jonathan; Morris, Rachel; Robinson, Stephen; Tucker, Rosemary; Walter, Talia; Young, Paul; Allen, Marcus; Fidalgo, Sara; Gard, Paul; Mabley, Jon; Patel, Bhavik; Chatterjee, Prabal; Yeoman, Mark

    2016-02-01

    Paraquat, a common herbicide, is responsible for large numbers of deaths worldwide through both deliberate and accidental ingestion. Previous studies have eluded that the bioavailability of paraquat increases substantially with increasing dose and that these changes may in part be due to the effects that these high concentrations have on the gastrointestinal tract (GI tract). To date, the actions of acute, high concentrations (20mM for 60 min) of paraquat on the GI tract, particularly the colon which is a major site of paraquat absorption, are unknown. This study examined the effects of acute paraquat administration on colonic motility in the C57BL/6 mouse. Acute paraquat exposure decreased colonic motility and the amplitude of colonic migrating motor complexes (CMMCs), which are major motor patterns involved in faecal pellet propulsion. In isolated segments of distal colon, paraquat increased resting tension and markedly attenuated electrical field stimulation-evoked relaxations. Pharmacological dissection of paraquat's mechanism of action on both the CMMCs and field stimulated tissue using the nitric oxide synthase inhibitor NG-nitro-L-arginine and direct measurement of NO release from the myenteric plexus, demonstrated that paraquat selectively attenuates nitrergic signalling pathways. These changes did not appear to be due to alterations in colonic oxidative stress, inflammation or complex 1 activity, but were most likely caused by paraquat's ability to act as a redox couple. In summary, these data demonstrate that acute paraquat exposure attenuates colonic transit. These changes may facilitate the absorption of paraquat into the circulation and so facilitate its toxicity.

  17. Insulin and GH Signaling in Human Skeletal Muscle In Vivo following Exogenous GH Exposure: Impact of an Oral Glucose Load

    OpenAIRE

    Thomas Krusenstjerna-Hafstrøm; Michael Madsen; Vendelbo, Mikkel H.; Pedersen, Steen B.; Christiansen, Jens S.; Niels Møller; Niels Jessen; Jørgensen, Jens O.L.

    2011-01-01

    INTRODUCTION: GH induces acute insulin resistance in skeletal muscle in vivo, which in rodent models has been attributed to crosstalk between GH and insulin signaling pathways. Our objective was to characterize time course changes in signaling pathways for GH and insulin in human skeletal muscle in vivo following GH exposure in the presence and absence of an oral glucose load. METHODS: Eight young men were studied in a single-blinded randomized crossover design on 3 occasions: 1) after an int...

  18. Agricultural adjuvants: acute mortality and effects on population growth rate of Daphnia pulex after chronic exposure.

    Science.gov (United States)

    Stark, John D; Walthall, William K

    2003-12-01

    Acute and chronic toxicity of eight agricultural adjuvants (Bond, Kinetic, Plyac, R-11, Silwet L-77, Sylgard 309, X-77, and WaterMaxx) to Daphnia pulex were evaluated with 48-h acute lethal concentration estimates (LC50) and a 10-d population growth-rate measurement, the instantaneous rate of increase (r1). Based on LC50, the order of toxicity was R-11 > X-77 = Sylgard 309 = Silwet L-77 > Kinetic > Bond > Plyac > WaterMaxx; all LC50 estimates were higher than the expected environmental concentration (EEC) of 0.79 mg/L, indicating that none of these adjuvants should cause high levels of mortality in wild D. pulex populations. Extinction, defined as negative population growth rate, occurred after exposure to 0.9 mg/L R-11, 13 mg/L X-77, 25 mg/L Kinetic, 28 mg/L Silwet, 18 mg/L Sylgard, 450 mg/L Bond, 610 mg/L Plyac, and 1,600 mg/L WaterMaxx. Concentrations that caused extinction were substantially below the acute LC50 for R-11, Kinetic, Plyac, X-77, and Bond. The no-observable-effects concentration (NOEC) and lowest-observable-effects concentration (LOEC) for the number of offspring per surviving female after exposure to R-11 were 0.5 and 0.75 mg/L, respectively. The NOEC and LOEC for population size after exposure to R-11 were (1.25 and 0.5 mg/L, respectively. Both of these values were lower than the EEC, indicating that R-11 does have the potential to cause damage to D. pulex populations after application at recommended field rates. The wide range of concentrations causing extinction makes it difficult to generalize about the potential impacts that agricultural adjuvants might have on aquatic ecosystems. Therefore, additional studies that examine effects on other nontarget organisms and determine residues in aquatic ecosystems may be warranted.

  19. Acute vertigo in an anesthesia provider during exposure to a 3T MRI scanner.

    Science.gov (United States)

    Gorlin, Andrew; Hoxworth, Joseph M; Pavlicek, William; Thunberg, Christopher A; Seamans, David

    2015-01-01

    Vertigo induced by exposure to the magnetic field of a magnetic resonance imaging (MRI) scanner is a well-known phenomenon within the radiology community but is not widely appreciated by other clinical specialists. Here, we describe a case of an anesthetist experiencing acute vertigo while providing sedation to a patient undergoing a 3 Tesla MRI scan. After discussing previous reports, and the evidence surrounding MRI-induced vertigo, we review potential etiologies that include the effects of both static and time-varying magnetic fields on the vestibular apparatus. We conclude our review by discussing the occupational standards that exist for MRI exposure and methods to minimize the risks of MRI-induced vertigo for clinicians working in the MRI environment.

  20. Human bocavirus in acute gastroenteritis in children in Brazil.

    Science.gov (United States)

    Campos, Gubio Soares; Silva Sampaio, Madina Lyve; Menezes, Aline Dorea Luz; Tigre, Dellane Martins; Moura Costa, Lilia Ferreira; Chinalia, Fabio Alexandre; Sardi, Silvia Ines

    2016-01-01

    Epidemiological surveillance for Human Bocavirus (HBoV) was conducted on 105 fecal specimens from children with acute gastroenteritis in Bahia, Brazil. Among of a total 105 stool samples, 44 samples were positive for HBoV as detected by nested-PCR. Of the 44 positive samples, co-infections with other enteric viruses (Norovirus, Adenovirus, and Rotavirus) were found in 12 pediatric patients. Mixed infections among HBoV with Norovirus were frequently observed in this population. The phylogenetic analysis identified the presence of HBoV-1, and HBoV 2A species. This study shows that HBoV is another viral pathogen in the etiology of acute gastroenteritis in children in Bahia, Brazil.

  1. Motor unit involvement in human acute Chagas' disease

    Directory of Open Access Journals (Sweden)

    O. R. Benavente

    1989-09-01

    Full Text Available Thirty five patients with acute Chagas' disease who demonstrated parasitaemia at the time of the investigation were submitted to a detailed electromyographical study. With their muscles at rest, 12 patients showed fibrillation potentials and/or positive sharp waves. On volitional contraction, 7 had short duration motor unit potentials (MUPs and low polyphasic MUPs. On motor and sensory nerve fibers conduction studies, 20 disclosed values below the lower control limit within one or more nerves. Finally, 12 patients produced a muscle, decremental response on nerve supramaximal repetitive stimulation. The findings signal that primary muscle involvement, neuropathy and impairement of the neuromuscular transmission, either isolated or combined, may be found in the acute stage of human Chagas' disease.

  2. Linearity of dose-response relationships for human carcinogenic exposures

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.H. (Univ. of California, Berkeley (USA))

    The shape of dose-response relationships is a critical factor in considering cancer risks for the work place and environmental exposure to carcinogens. Markedly different risk estimates result from assumptions of linearity versus sublinear and threshold assumptions. This paper presents evidence that the relationship between the relative risk of development of cancer and the dose rate to carcinogenic exposures is frequently linear with no evidence for thresholds. Dose-response relationships from four studies of asbestos and lung cancer were examined, all of which were consistent with a linear relationship. Analysis of the relationship between the relative risk of lung cancer and exposure to nickel in a smelter study, selected because of relatively good exposure data, demonstrated a close agreement with a linear relationship. The relationship between the level of arsenic in drinking wter and the prevalence of skin cancer also was linear for males in the highest prevalence age group in Taiwan, although there was some evidence of sublinearity for females and younger persons. Also, the relationships between the number of cigarettes smoked per day and the relative risk of lung cancer was very close to linear in many studies. The analysis of these and other studies involving human exposure to carcinogens provides empirical evidence for linearity when the response variable is a rate ratio measure, rather than a risk difference measure. Linearity in dose-response is biologically plausible, without invoking a one-hit model. Except in special circumstances. the epidemiological evidence supports linear extrapolation of cancer relative risks.

  3. Rapid Evolution from the First Episode of Acute Pancreatitis to Chronic Pancreatitis in Human Subjects

    OpenAIRE

    Elie Aoun; Adam Slivka; Papachristou, Dionysios J.; Whitcomb, David C.; Gleeson, Ferga C; Papachristou, Georgios I

    2007-01-01

    Context Growing evidence suggests that recurrent acute pancreatitis leads to chronic pancreatitis, but this sequence is seldom reported in human subjects. The sentinel acute pancreatitis event hypothesis suggests that an initial episode of acute pancreatitis is the first step in a complicated series of events ultimately leading to chronic pancreatitis. Objective To identify patients who evolved from recurrent acute pancreatitis to chronic pancreatitis. Setting The Severity of Acute Pancreatit...

  4. Electrocardiographic and autonomic effects of acute particulate matter (PM) exposure in a rat model of cardiomyopathy

    Science.gov (United States)

    Human exposure to ambient PM from fossil-fuel emissions is linked to cardiovascular disease and death. This association strengthens in people with preexisting cardiac disease--especially heart failure (HF). Cardiomyopathy is the most common cause of heart failure. The mechanisms ...

  5. Gene expression changes in female zebrafish (Danio rerio) brain in response to acute exposure to methylmercury

    Science.gov (United States)

    Richter, Catherine A.; Garcia-Reyero, Natàlia; Martyniuk, Chris; Knoebl, Iris; Pope, Marie; Wright-Osment, Maureen K.; Denslow, Nancy D.; Tillitt, Donald E.

    2011-01-01

    Methylmercury (MeHg) is a potent neurotoxicant and endocrine disruptor that accumulates in aquatic systems. Previous studies have shown suppression of hormone levels in both male and female fish, suggesting effects on gonadotropin regulation in the brain. The gene expression profile in adult female zebrafish whole brain induced by acute (96 h) MeHg exposure was investigated. Fish were exposed by injection to 0 or 0.5(mu or u)g MeHg/g. Gene expression changes in the brain were examined using a 22,000-feature zebrafish microarray. At a significance level of pgenes were up-regulated and 76 genes were down-regulated in response to MeHg exposure. Individual genes exhibiting altered expression in response to MeHg exposure implicate effects on glutathione metabolism in the mechanism of MeHg neurotoxicity. Gene ontology (GO) terms significantly enriched among altered genes included protein folding, cell redox homeostasis, and steroid biosynthetic process. The most affected biological functions were related to nervous system development and function, as well as lipid metabolism and molecular transport. These results support the involvement of oxidative stress and effects on protein structure in the mechanism of action of MeHg in the female brain. Future studies will compare the gene expression profile induced in response to MeHg with that induced by other toxicants and will investigate responsive genes as potential biomarkers of MeHg exposure.

  6. Exposure to Discrimination and Heart Rate Variability Reactivity to Acute Stress among Women with Diabetes.

    Science.gov (United States)

    Wagner, Julie; Lampert, Rachel; Tennen, Howard; Feinn, Richard

    2015-08-01

    Exposure to racial discrimination has been linked to physiological reactivity. This study investigated self-reported exposure to racial discrimination and parasympathetic [high-frequency heart rate variability (HF-HRV)] and sympathetic (norepinephrine and cortisol) activity at baseline and then again after acute laboratory stress. Lifetime exposure to racial discrimination was measured with the Schedule of Racist Events scale. Thirty-two women (16 Black and 16 White) with type 2 diabetes performed a public speaking stressor. Beat-to-beat intervals were recorded on electrocardiograph recorders, and HF-HRV was calculated using spectral analysis and natural log transformed. Norepinephrine and cortisol were measured in blood. Higher discrimination predicted lower stressor HF-HRV, even after controlling for baseline HF-HRV. When race, age, A1c and baseline systolic blood pressure were also controlled, racial discrimination remained a significant independent predictor of stressor HF-HRV. There was no association between lifetime discrimination and sympathetic markers. In conclusion, preliminary data suggest that among women with type 2 diabetes mellitus (T2DM), exposure to racial discrimination is adversely associated with parasympathetic, but not sympathetic, reactivity. Copyright © 2013 John Wiley & Sons, Ltd.

  7. Pulmonary arachidonic acid metabolism following acute exposures to ozone and nitrogen dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Schlesinger, R.B.; Driscoll, K.E.; Gunnison, A.F.; Zelikoff, J.T. (New York Univ. Medical Center, NY (USA))

    1990-12-01

    Ozone (O{sub 3}) and nitrogen dioxide (NO{sub 2}) are common air pollutants, and exposure to these gases has been shown to affect pulmonary physiology, biochemistry, and structure. This study examined their ability to modulate arachidonic acid metabolites (eicosanoids) in the lungs. Rabbits were exposed for 2 h to O{sub 3} at 0.1, 0.3, or 1 ppm; NO{sub 2} at 1, 3, or 10 ppm; or to a mixture of 0.3 ppm O{sub 3} and 3 ppm NO{sub 2}. Groups of animals sacrificed either immediately or 24 h after each exposure underwent broncho-pulmonary lavage. Selected eicosanoids were assessed in lavage fluid by radioimmunoassay. Increases in prostaglandins E2 (PGE2) and F2 alpha (PGF2 alpha) were found immediately after exposure to 1 ppm O{sub 3}. Exposure to 10 ppm NO{sub 2} resulted in a depression of 6-keto-PGF1 alpha, while thromboxane B2 (TxB2) was elevated after exposure to 1 ppm NO{sub 2} and depressed following 3 and 10 ppm. The O{sub 3}/NO{sub 2} mixture resulted in synergistic increases in PGE2 and PGF2 alpha, with the response appearing to be driven by O{sub 3}. This study has demonstrated that acute exposure to either O{sub 3} or NO{sub 2} can alter pulmonary arachidonic acid metabolism and that the responses to these oxidants differ, both quantitatively and qualitatively.

  8. C57BL/6 Substrains Exhibit Different Responses to Acute Carbon Tetrachloride Exposure: Implications for Work Involving Transgenic Mice.

    Science.gov (United States)

    McCracken, Jennifer M; Chalise, Prabhakar; Briley, Shawn M; Dennis, Katie L; Jiang, Lu; Duncan, Francesca E; Pritchard, Michele T

    2017-07-07

    Biological differences exist between strains of laboratory mice, and it is becoming increasingly evident that there are differences between substrains. In the C57BL/6 mouse, the primary substrains are called 6J and 6N. Previous studies have demonstrated that 6J and 6N mice differ in response to many experimental models of human disease. The aim of our study was to determine if differences exist between 6J and 6N mice in terms of their response to acute carbon tetrachloride (CCl4) exposure. Mice were given CCl4 once and were euthanized 12 to 96 h later. Relative to 6J mice, we found that 6N mice had increased liver injury but more rapid repair. This was because of the increased speed with which necrotic hepatocytes were removed in 6N mice and was directly related to increased recruitment of macrophages to the liver. In parallel, enhanced liver regeneration was observed in 6N relative to 6J mice. Hepatic stellate cell activation occurred earlier in 6N mice, but there was no difference in matrix metabolism between substrains. Taken together, these data demonstrate specific and significant differences in how the C57BL/6 substrains respond to acute CCl4, which has important implications for all mouse studies utilizing this model.

  9. Acute health effects associated with exposure to volcanic air pollution (vog) from increased activity at Kilauea Volcano in 2008.

    Science.gov (United States)

    Longo, Bernadette M; Yang, Wei; Green, Joshua B; Crosby, Frederick L; Crosby, Vickie L

    2010-01-01

    In 2008, the Kilauea Volcano on the island of Hawai'i increased eruption activity and emissions of sulfurous volcanic air pollution called vog. The purpose of this study was to promptly assess for a relative increase in cases of medically diagnosed acute illnesses in an exposed Hawaiian community. Using a within-clinic retrospective cohort design, comparisons were made for visits of acute illnesses during the 14 wk prior to the increased volcanic emissions (low exposure) to 14 wk of high vog exposure when ambient sulfur dioxide was threefold higher and averaged 75 parts per billion volume per day. Logistic regression analysis estimated effect measures between the low- and high-exposure cohorts for age, gender, race, and smoking status. There were statistically significant positive associations between high vog exposure and visits for medically diagnosed cough, headache, acute pharyngitis, and acute airway problems. More than a sixfold increase in odds was estimated for visits with acute airway problems, primarily experienced by young Pacific Islanders. These findings suggest that the elevated volcanic emissions in 2008 were associated with increased morbidity of acute illnesses in age and racial subgroups of the general Hawaiian population. Continued investigation is crucial to fully assess the health impact of this natural source of sulfurous air pollution. Culturally appropriate primary- and secondary-level health prevention initiatives are recommended for populations in Hawai'i and volcanically active areas worldwide.

  10. Experimental Models in Syrian Golden Hamster Replicate Human Acute Pancreatitis.

    Science.gov (United States)

    Wang, Yunan; Kayoumu, Abudurexiti; Lu, Guotao; Xu, Pengfei; Qiu, Xu; Chen, Liye; Qi, Rong; Huang, Shouxiong; Li, Weiqin; Wang, Yuhui; Liu, George

    2016-06-15

    The hamster has been shown to share a variety of metabolic similarities with humans. To replicate human acute pancreatitis with hamsters, we comparatively studied the efficacy of common methods, such as the peritoneal injections of caerulein, L-arginine, the retrograde infusion of sodium taurocholate, and another novel model with concomitant administration of ethanol and fatty acid. The severity of pancreatitis was evaluated by serum amylase activity, pathological scores, myeloperoxidase activity, and the expression of inflammation factors in pancreas. The results support that the severity of pathological injury is consistent with the pancreatitis induced in mice and rat using the same methods. Specifically, caerulein induced mild edematous pancreatitis accompanied by minimal lung injury, while L-arginine induced extremely severe pancreatic injury including necrosis and neutrophil infiltration. Infusion of Na-taurocholate into the pancreatic duct induced necrotizing pancreatitis in the head of pancreas and lighter inflammation in the distal region. The severity of acute pancreatitis induced by combination of ethanol and fatty acids was between the extent of caerulein and L-arginine induction, with obvious inflammatory cells infiltration. In view of the advantages in lipid metabolism features, hamster models are ideally suited for the studies of pancreatitis associated with altered metabolism in humans.

  11. Evaluating Systemic Toxicity in Rabbits after Acute Ocular Exposure to Irritant Chemicals

    Directory of Open Access Journals (Sweden)

    Reshma Sebastian Cherian

    2014-01-01

    Full Text Available Acute systemic toxicity via ocular exposure route is not a well understood aspect. Any material/drug/chemical that comes in contact with the eye can evade the first pass metabolism and enter the systemic circulation through the conjunctival blood vessels or via the nasolacrimal route. In this study, the effect of ocular irritant chemicals on the systemic toxicity was assessed in rabbit. Eyes of rabbits were exposed to known ocular irritant (cetyl pyridinium chloride, sodium salicylate, imidazole, acetaminophen, and nicotinamide for 24 h and scored. After a period of 72 h, blood was collected from the animals for examining the hematological and biochemical parameters. The animals were then sacrificed and the eyes were collected for histopathology and cytokine analysis by ELISA. Splenocyte proliferation was assessed by tritiated thymidine incorporation assay. The liver and brain of the treated animals were retrieved for evaluating oxidative damage. The chemicals showed moderate to severe eye irritation. Inflammation was not evident in the histopathology but proinflammatory markers were significantly high. The splenocyte proliferation capacity was undeterred. And there was minimal oxidative stress in the brain and liver. In conclusion, acute exposure of ocular irritants was incapable of producing a prominent systemic side effect in the current scenario.

  12. Acute radiation enteritis caused by dose-dependent radiation exposure in dogs: experimental research.

    Science.gov (United States)

    Xu, Wenda; Chen, Jiang; Xu, Liu; Li, Hongyu; Guo, Xiaozhong

    2014-12-01

    Accidental or intended radiation exposure in mass casualty settings presents a serious and on-going threat. The development of mitigating and treating agents requires appropriate animal models. Unfortunately, the majority of research on radiation enteritis in animals has lacked specific assessments and targeted therapy. Our study showed beagle dogs, treated by intensity-modulated radiation therapy (IMRT) for abdominal irradiation, were administered single X-ray doses of 8-30 Gy. The degree of intestinal tract injury for all of the animals after radiation exposure was evaluated with regard to clinical syndrome, endoscopic findings, histological features, and intestinal function. The range of single doses (8 Gy, 10-14 Gy, and 16-30 Gy) represented the degree of injury (mild, moderate, and severe, respectively). Acute radiation enteritis included clinical syndrome with fever, vomiting, diarrhea, hemafecia, and weight loss; typical endoscopic findings included edema, bleeding, mucosal abrasions, and ulcers; and intestinal biopsy results revealed mucosal necrosis, erosion, and loss, inflammatory cell infiltration, hemorrhage, and congestion. Changes in serum diamine oxides (DAOs) and d-xylose represented intestinal barrier function and absorption function, respectively, and correlated with the extent of damage (P enteritis, thus obtaining a relatively objective evaluation of intestinal tract injury based on clinical performance and laboratory examination. The method of assessment of the degree of intestinal tract injury after abdominal irradiation could be beneficial in the development of novel and effective therapeutic strategies for acute radiation enteritis.

  13. Acute on chronic exposure to endotoxin is associated with enhanced chemoreflex responses in preterm fetal sheep.

    Science.gov (United States)

    Booth, Lindsea C; Drury, Paul P; Muir, Cameron; Jensen, Ellen C; Gunn, Alistair J; Bennet, Laura

    2013-05-15

    There is increasing evidence that exposure to infection can sensitize the fetus to subsequent hypoxic injury. However, it is unclear whether this involves compromise of the fetal cardiovascular adaptation to acute asphyxia. Chronically instrumented 103-day-old (0.7 gestational age, term is 147 days) fetal sheep in utero were randomized to receive either gram-negative lipopolysaccharide (LPS) as a continuous low-dose infusion for 120 h plus boluses of 1 μg LPS at 48, 72, and 96 h with asphyxia at 102 h (i.e., 6 h after the final LPS bolus) induced by umbilical cord occlusion for 15 min (LPS treated, n = 8), or the same volume of saline plus occlusion (saline treated, n = 7). Fetuses were killed 5 days after occlusion. LPS was associated with a more rapid fall in fetal heart rate at the onset of occlusion (P fall in CaBF to similar values as saline controls during occlusion. There were no differences between the groups in femoral blood flow before or during occlusion. Contrary to our initial hypothesis, acute on chronic exposure to LPS was associated with more rapid cardiovascular adaptation to umbilical cord occlusion.

  14. [Reactive microglial changes in rat neocortex and hippocampus after exposure to acute perinatal hypoxia].

    Science.gov (United States)

    Khozhaĭ, L I; Otellin, V A

    2013-01-01

    The dynamics of reactive changes of a population density of microglial cells and the reversibility of their phenotypic forms were studied in the brain of neonatal rats at different time intervals after 1 hr-long exposure to acute normobaric hypoxia in the pressure chamber at the second postnatal day. Different areas of the neocortex (frontal, motor, somatosensory and visual) and of the hippocampus (CAI, CA3, CA4 and fascia dentata) were examined 1 hr, 3 hrs, 1 and 5 days after exposure to hypoxia. Microglial cells were demonstrated using an immunocytochemical staining with the monoclonal antibodies against Iba- 1 antigen. The results have shown that the reaction of microglia to acute hypoxia in both the neocortex and the hippocampus of the new-borns developed simultaneously and synchronously with the augmentation of cell death. The increase of a population density of amoeboid form of microglial cells in the brain areas studied was recorded already after 1 hour as a result of their migration from the subventricular region and the areas adjacent to large vessels from where they practically disappeared. The number of amoeboid microglial cells in this area has recovered rather quickly (in 3 hrs). The population densify of microglial cells, especially of amoeboid forms, sharply increased with the augmentation of cell death and remained unchanged for about 5 days.

  15. Role of carbon monoxide in impaired endothelial function mediated by acute second-hand tobacco, incense, and candle smoke exposures.

    Science.gov (United States)

    Weber, Lynn P; Al-Dissi, Ahmad; Marit, Jordan S; German, Timothy N; Terletski, Sharilyn D

    2011-05-01

    The aim of this study was to determine if carbon monoxide (CO) is responsible for acute adverse cardiovascular effects of different sources of smoke: second-hand tobacco smoke (SHS), incense and candle smoke. Endothelial function was tested using flow-mediated dilation (FMD) in pigs and was shown to be sensitive to nitric oxide synthase blockade. Subsequent experiments showed that FMD was significantly impaired compared to sham-exposed pigs at 30 min after a 30-min exposure to all three sources of smoke. In contrast, SHS significantly increased systolic, diastolic and pulse pressures compared to sham-exposure, while both incense and candle smoke exposure had no effect. The FMD impairment correlated well with CO levels in the exposure chamber, but not total particulates or venous CO-hemoglobin. Therefore, this study suggests a gas phase component of smoke that accompanies CO, but not CO itself, is responsible for acute endothelial dysfunction after SHS, incense or candle smoke exposure.

  16. Analogue peptides for the immunotherapy of human acute myeloid leukemia.

    Science.gov (United States)

    Hofmann, Susanne; Mead, Andrew; Malinovskis, Aleksandrs; Hardwick, Nicola R; Guinn, Barbara-Ann

    2015-11-01

    The use of peptide vaccines, enhanced by adjuvants, has shown some efficacy in clinical trials. However, responses are often short-lived and rarely induce notable memory responses. The reason is that self-antigens have already been presented to the immune system as the tumor develops, leading to tolerance or some degree of host tumor cell destruction. To try to break tolerance against self-antigens, one of the methods employed has been to modify peptides at the anchor residues to enhance their ability to bind major histocompatibility complex molecules, extending their exposure to the T-cell receptor. These modified or analogue peptides have been investigated as stimulators of the immune system in patients with different cancers with variable but sometimes notable success. In this review we describe the background and recent developments in the use of analogue peptides for the immunotherapy of acute myeloid leukemia describing knowledge useful for the application of analogue peptide treatments for other malignancies.

  17. Sustained impairment of respiratory function and swim performance following acute oil exposure in a coastal marine fish.

    Science.gov (United States)

    Johansen, J L; Esbaugh, A J

    2017-06-01

    Acute exposure to crude oil polycyclic aromatic hydrocarbons (PAH) can severely impair cardiorespiratory function and swim performance of larval fish; however, the effects of acute oil exposure on later life stages and the capacity for subsequent recovery is less clear. Red drum (Sciaenops ocellatus) is an economically important apex predator native to the Gulf of Mexico, which was directly exposed to the 2010 Deep Water Horizon (DWH) oil spill. Here we examine impact and recovery of young adult red drum from exposure to concentrations of 0, 4.1, and 12.1μgL(-1) ΣPAH50 naturally weathered oil-water accommodated fractions (geometric mean), which are well within the range of concentrations measured during the DWH incident. We focused on aerobic scope (ASc), burst- and critical swimming speeds (Uburst and Ucrit), cost of transport (COT), as well as the capacity to repay oxygen debt following exhaustive exercise (EPOC), which are critical parameters for success of all life stages of fishes. A 24h acute exposure to 4.1μgL(-1) ΣPAH caused a significant 9.7 and 12.6% reduction of Uburst and Ucrit respectively, but no change in ASc, COT or EPOC, highlighting a decoupled effect on the respiratory and swimming systems. A higher exposure concentration, 12.1μgL(-1) ΣPAH, caused an 8.6 and 8.4% impairment of Uburst and Ucrit, as well as an 18.4% reduction in ASc. These impairments persisted six weeks post-exposure, suggesting that recorded impacts are entrenched. Large predatory fishes are critically dependent on the cardiorespiratory and swimming systems for ecological fitness, and long-term impairment of performance due to acute oil exposure suggests that even acute exposure events may have long lasting impacts on the ecological fitness of affected populations. Copyright © 2017. Published by Elsevier B.V.

  18. Carryover Effects of Acute DEHP Exposure on Ovarian Function and Oocyte Developmental Competence in Lactating Cows.

    Science.gov (United States)

    Kalo, Dorit; Hadas, Ron; Furman, Ori; Ben-Ari, Julius; Maor, Yehoshua; Patterson, Donald G; Tomey, Cynthia; Roth, Zvi

    2015-01-01

    We examined acute exposure of Holstein cows to di(2-ethylhexyl) phthalate (DEHP) and its carryover effects on ovarian function and oocyte developmental competence. Synchronized cows were tube-fed with water or 100 mg/kg DEHP per day for 3 days. Blood, urine and milk samples were collected before, during and after DEHP exposure to examine its clearance pattern. Ovarian follicular dynamics was monitored through an entire estrous cycle by ultrasonographic scanning. Follicular fluids were aspirated from the preovulatory follicles on days 0 and 29 of the experiment and analyzed for phthalate metabolites and estradiol concentration. The aspirated follicular fluid was used as maturation medium for in-vitro embryo production. Findings revealed that DEHP impairs the pattern of follicular development, with a prominent effect on dominant follicles. The diameter and growth rate of the first- and second-wave dominant follicles were lower (P 25 mm). The pattern of growth and regression of the corpus luteum differed between groups, with a lower volume in the DEHP-treated group (P < 0.05). The follicular fluid aspirated from the DEHP-treated group, but not the controls, contained 23 nM mono(2-ethylhexyl) phthalate. Culturing of cumulus oocyte complexes in the follicular fluid aspirated from DEHP-treated cows reduced the proportion of oocytes progressing to the MII stage, and the proportions of 2- to 4-cell-stage embryos (P < 0.04) and 7-day blastocysts (P < 0.06). The results describe the risk associated with acute exposure to DEHP and its deleterious carryover effects on ovarian function, nuclear maturation and oocyte developmental competence.

  19. Carryover Effects of Acute DEHP Exposure on Ovarian Function and Oocyte Developmental Competence in Lactating Cows

    Science.gov (United States)

    Kalo, Dorit; Hadas, Ron; Furman, Ori; Ben-Ari, Julius; Maor, Yehoshua; Patterson, Donald G.; Tomey, Cynthia; Roth, Zvi

    2015-01-01

    We examined acute exposure of Holstein cows to di(2-ethylhexyl) phthalate (DEHP) and its carryover effects on ovarian function and oocyte developmental competence. Synchronized cows were tube-fed with water or 100 mg/kg DEHP per day for 3 days. Blood, urine and milk samples were collected before, during and after DEHP exposure to examine its clearance pattern. Ovarian follicular dynamics was monitored through an entire estrous cycle by ultrasonographic scanning. Follicular fluids were aspirated from the preovulatory follicles on days 0 and 29 of the experiment and analyzed for phthalate metabolites and estradiol concentration. The aspirated follicular fluid was used as maturation medium for in-vitro embryo production. Findings revealed that DEHP impairs the pattern of follicular development, with a prominent effect on dominant follicles. The diameter and growth rate of the first- and second-wave dominant follicles were lower (P 25 mm). The pattern of growth and regression of the corpus luteum differed between groups, with a lower volume in the DEHP-treated group (P < 0.05). The follicular fluid aspirated from the DEHP-treated group, but not the controls, contained 23 nM mono(2-ethylhexyl) phthalate. Culturing of cumulus oocyte complexes in the follicular fluid aspirated from DEHP-treated cows reduced the proportion of oocytes progressing to the MII stage, and the proportions of 2- to 4-cell-stage embryos (P < 0.04) and 7-day blastocysts (P < 0.06). The results describe the risk associated with acute exposure to DEHP and its deleterious carryover effects on ovarian function, nuclear maturation and oocyte developmental competence. PMID:26154164

  20. Carryover Effects of Acute DEHP Exposure on Ovarian Function and Oocyte Developmental Competence in Lactating Cows.

    Directory of Open Access Journals (Sweden)

    Dorit Kalo

    Full Text Available We examined acute exposure of Holstein cows to di(2-ethylhexyl phthalate (DEHP and its carryover effects on ovarian function and oocyte developmental competence. Synchronized cows were tube-fed with water or 100 mg/kg DEHP per day for 3 days. Blood, urine and milk samples were collected before, during and after DEHP exposure to examine its clearance pattern. Ovarian follicular dynamics was monitored through an entire estrous cycle by ultrasonographic scanning. Follicular fluids were aspirated from the preovulatory follicles on days 0 and 29 of the experiment and analyzed for phthalate metabolites and estradiol concentration. The aspirated follicular fluid was used as maturation medium for in-vitro embryo production. Findings revealed that DEHP impairs the pattern of follicular development, with a prominent effect on dominant follicles. The diameter and growth rate of the first- and second-wave dominant follicles were lower (P 25 mm. The pattern of growth and regression of the corpus luteum differed between groups, with a lower volume in the DEHP-treated group (P < 0.05. The follicular fluid aspirated from the DEHP-treated group, but not the controls, contained 23 nM mono(2-ethylhexyl phthalate. Culturing of cumulus oocyte complexes in the follicular fluid aspirated from DEHP-treated cows reduced the proportion of oocytes progressing to the MII stage, and the proportions of 2- to 4-cell-stage embryos (P < 0.04 and 7-day blastocysts (P < 0.06. The results describe the risk associated with acute exposure to DEHP and its deleterious carryover effects on ovarian function, nuclear maturation and oocyte developmental competence.

  1. Anticholinergic drug exposure is associated with delirium and postdischarge institutionalization in acutely ill hospitalized older patients.

    Science.gov (United States)

    Egberts, Angelique; van der Craats, Saskia T; van Wijk, Melissa D; Alkilabe, Shams; van den Bemt, Patricia M L A; Mattace-Raso, Francesco U S

    2017-06-01

    Several studies investigated the possible association between anticholinergic drugs and diverse clinical outcomes in older persons, but the results are inconsistent. The aim of this study was to investigate whether anticholinergic drug exposure is associated with delirium on admission, length of hospital stay, postdischarge institutionalization and in-hospital mortality in acutely ill hospitalized older patients. In this observational chart review study, we included acutely ill patients aged 65 and older who were admitted to the geriatric ward of the Erasmus University Medical Center, Rotterdam, The Netherlands, between 2012 and 2015 (n = 905). Anticholinergic drug exposure on admission was defined as the use of anticholinergic drugs, total number of anticholinergic drugs and anticholinergic drug burden score (ADB), quantified with the Anticholinergic Risk Scale (ARS), the Anticholinergic Cognitive Burden scale (ACB) and the list of Chew et al. (Chew). Logistic regression analyses were performed to investigate possible associations between anticholinergic drug exposure and the aforementioned outcomes. Analyses were adjusted for age, sex, comorbidities, non-anticholinergic drugs and delirium, where appropriate. Moderate and high ADB measured with the ARS were associated with delirium on admission with odds ratios (OR) of 1.70 (95% confidence interval (CI) = 1.16-2.49) and 1.83 (95% CI = 1.06-3.15), respectively. High ADB measured with the ARS was also associated with postdischarge institutionalization (OR = 2.43, 95% CI = 1.24-4.75). No associations were found using the ACB and Chew. Future studies are warranted to investigate the clinical usefulness of the ARS in reducing complications in older persons.

  2. Acute and recent air pollution exposure and cardiovascular events at labour and delivery

    Science.gov (United States)

    Männistö, Tuija; Mendola, Pauline; Grantz, Katherine Laughon; Leishear, Kira; Sundaram, Rajeshwari; Sherman, Seth; Ying, Qi; Liu, Danping

    2017-01-01

    Objective To study the relationship between acute air pollution exposure and cardiovascular events during labour/delivery. Methods The Consortium on Safe Labor (2002–2008), an observational US cohort with 223 502 singleton deliveries provided electronic medical records. Air pollution exposure was estimated by modified Community Multiscale Air Quality models. Cardiovascular events (cardiac failure/arrest, stroke, myocardial infarcts and other events) were recorded in the hospital discharge records for 687 pregnancies (0.3%). Logistic regression with generalised estimating equations estimated the relationship between cardiovascular events and daily air pollutant levels for delivery day and the 7 days preceding delivery. Results Increased odds of cardiovascular events were observed for each IQR increase in exposure to nitric oxides at 5 and 6 days prior to delivery (OR=1.17, 99% CI 1.04 to 1.30 and OR=1.15, 1.03 to 1.28, respectively). High exposure to toxic air pollution species such as ethylbenzene (OR=1.50, 1.08 to 2.09), m-xylene (OR=1.54, 1.11 to 2.13), o-xylene (OR=1.51, 1.09 to 2.09), p-xylene (OR=1.43, 1.03 to 1.99) and toluene (OR=1.42, 1.02 to 1.97) at 5 days prior to delivery were also associated with cardiovascular events. Decreased odds of events were observed with exposure to ozone. Conclusions Air pollution in the days prior to delivery, especially nitrogen oxides and some toxic air pollution species, was associated with increased risk of cardiovascular events during the labour/delivery admission. PMID:26105036

  3. Human performance analysis of industrial radiography radiation exposure events

    Energy Technology Data Exchange (ETDEWEB)

    Reece, W.J.; Hill, S.G.

    1995-12-01

    A set of radiation overexposure event reports were reviewed as part of a program to examine human performance in industrial radiography for the US Nuclear Regulatory Commission. Incident records for a seven year period were retrieved from an event database. Ninety-five exposure events were initially categorized and sorted for further analysis. Descriptive models were applied to a subset of severe overexposure events. Modeling included: (1) operational sequence tables to outline the key human actions and interactions with equipment, (2) human reliability event trees, (3) an application of an information processing failures model, and (4) an extrapolated use of the error influences and effects diagram. Results of the modeling analyses provided insights into the industrial radiography task and suggested areas for further action and study to decrease overexposures.

  4. Biology and relevance of human acute myeloid leukemia stem cells.

    Science.gov (United States)

    Thomas, Daniel; Majeti, Ravindra

    2017-03-23

    Evidence of human acute myeloid leukemia stem cells (AML LSCs) was first reported nearly 2 decades ago through the identification of rare subpopulations of engrafting cells in xenotransplantation assays. These AML LSCs were shown to reside at the apex of a cellular hierarchy that initiates and maintains the disease, exhibiting properties of self-renewal, cell cycle quiescence, and chemoresistance. This cancer stem cell model offers an explanation for chemotherapy resistance and disease relapse and implies that approaches to treatment must eradicate LSCs for cure. More recently, a number of studies have both refined and expanded our understanding of LSCs and intrapatient heterogeneity in AML using improved xenotransplant models, genome-scale analyses, and experimental manipulation of primary patient cells. Here, we review these studies with a focus on the immunophenotype, biological properties, epigenetics, genetics, and clinical associations of human AML LSCs and discuss critical questions that need to be addressed in future research. © 2017 by The American Society of Hematology.

  5. Raman spectroscopy of human saliva for acute myocardial infarction detection

    Science.gov (United States)

    Chen, Maowen; Chen, Yuanxiang; Wu, Shanshan; Huang, Wei; Lin, Jinyong; Weng, Guo-Xing; Chen, Rong

    2014-09-01

    Raman spectroscopy is a rapidly non-invasive technique with great potential for biomedical research. The aim of this study was to evaluate the feasibility of using Raman spectroscopy of human saliva for acute myocardial infarction (AMI) detection. Raman spectroscopy measurements were performed on two groups of saliva samples: one group from patients (n=30) with confirmed AMI and the other group from healthy controls (n=31). The diagnostic performance for differentiating AMI saliva from normal saliva was evaluated by multivariate statistical analysis. The combination of principal component analysis (PCA) and linear discriminate analysis (LDA) of the measured Raman spectra separated the spectral features of the two groups into two distinct clusters with little overlaps, rendering the sensitivity of 80.0% and specificity of 80.6%. The results from this exploratory study demonstrated that Raman spectroscopy of human saliva can serve as a potentially clinical tool for rapid AMI detection and screening.

  6. Acute and chronic effects of glyceryl trinitrate therapy on insulin and glucose regulation in humans.

    Science.gov (United States)

    Jedrzkiewicz, Sean; Parker, John D

    2013-05-01

    This study examined the effect of acute and sustained transdermal glyceryl trinitrate (GTN) therapy on insulin and glucose regulation. Totally, 12 males (18-30 years) underwent a glucose tolerance test at baseline (visit 1), 90 minutes after acute transdermal GTN 0.6 mg/h (visit 2), following 7 days of continuous GTN (visit 3), and 2 to 3 days after stopping GTN (visit 4). At each visit, plasma glucose and insulin concentrations were measured before and 30, 60, 90, and 120 minutes after a 75-g oral glucose load. Indices of glucose metabolism that were examined included the insulin sensitivity index, the homeostasis model assessment of insulin resistance (HOMA-IR), and the insulinogenic index. The acute administration of GTN had no effect on glucose and insulin responses (visit 2). However, after 7 days of GTN exposure (visit 3) there was an increase in the mean glucose concentration measured after the oral glucose load. On visit 1, the mean glucose concentration (± standard deviation) following the 75 g oral glucose challenge was 5.7 ± 0.5 µmol/L. On visit 3, after 7 days of transdermal GTN therapy, the mean glucose concentration after the oral glucose was significantly higher; 6.2 ± 0.5 µmol/L (P GTN therapy modifies glucose metabolism causing evidence of increased insulin resistance during sustained therapy in normal humans.

  7. DUAL ION EXPOSURE VS. SPLIT-DOSE EXPOSURES IN HUMAN CELL NEOPLASTIC TRANSFORMATION.

    Energy Technology Data Exchange (ETDEWEB)

    BENNETT, P.V.; CUTTER, N.C.; SUTHERLAND, B.M.

    2006-06-05

    Since radiation fields of space contain many-fold more protons than high atomic number, high energy (HZE) particles, cells in astronaut crews will experience on average several proton hits before an HZE hit. Thus radiation regimes of proton exposure before HZE particle exposure simulate space radiation exposure, and measurement of the frequency of neoplastic transformation of human primary cells to anchorage-independent growth simulates in initial step in cancer induction. Previously our group found that exposure to 20 cGy 1 GeV/n protons followed within about 1 hr by a HZE ion (20 cGy 1 GeV/n Fe or Ti ions) hit gave about a 3-fold increase in transformation frequency ([1]). To provide insight into the H-HZE induced increased transformation frequencies, we asked if split doses of the same ion gave similar increased transformation frequencies. However, the data show that the split dose of 20 cGy plus 20 cGy of either H or HZE ions gave about the same effect as the 40 cGy uninterrupted dose, quite different from the effect of the mixed ion H + HZE irradiation. We also asked if lower proton doses than 20 cGy followed 15 minutes later by 20 cGy of HZE ions gave greater than additive transformation frequencies. Substantial increases in transformation levels were observed for all proton doses tested, including 1 cGy. These results point to the signal importance of protons in affecting the effect of space radiation on human cells.

  8. Ozone Exposure Increases Circulating Stress Hormones and Lipid Metabolites in Humans

    Science.gov (United States)

    RATIONALE: Air pollution has been associated with increased prevalence of type 2 diabetes; however, the mechanisms remain unknown. We have shown that acute ozone exposure in rats induces release of stress hormones, hyperglycemia, leptinemia, and gluoose intolerance that are assoc...

  9. Rapid microRNA changes in airways of human volunteers after controlled exposure to air pollutants

    Science.gov (United States)

    Introduction/Rationale: Exposure to air pollutants, including ozone and diesel exhaust (DE) are known to cause acute cardiopulmonary dysfunction; however, the molecular mechanisms underlying these changes remain elusive. One mechanism for rapid regulation of multiple genes is a...

  10. Human rhinovirus infection in young African children with acute wheezing

    Directory of Open Access Journals (Sweden)

    Zar Heather J

    2011-03-01

    Full Text Available Abstract Background Infections caused by human rhinoviruses (HRVs are important triggers of wheezing in young children. Wheezy illness has increasingly been recognised as an important cause of morbidity in African children, but there is little information on the contribution of HRV to this. The aim of this study was to determine the role of HRV as a cause of acute wheezing in South African children. Methods Two hundred and twenty children presenting consecutively at a tertiary children's hospital with a wheezing illness from May 2004 to November 2005 were prospectively enrolled. A nasal swab was taken and reverse transcription PCR used to screen the samples for HRV. The presence of human metapneumovirus, human bocavirus and human coronavirus-NL63 was assessed in all samples using PCR-based assays. A general shell vial culture using a pool of monoclonal antibodies was used to detect other common respiratory viruses on 26% of samples. Phylogenetic analysis to determine circulating HRV species was performed on a portion of HRV-positive samples. Categorical characteristics were analysed using Fisher's Exact test. Results HRV was detected in 128 (58.2% of children, most (72% of whom were under 2 years of age. Presenting symptoms between the HRV-positive and negative groups were similar. Most illness was managed with ambulatory therapy, but 45 (35% were hospitalized for treatment and 3 (2% were admitted to intensive care. There were no in-hospital deaths. All 3 species of HRV were detected with HRV-C being the most common (52% followed by HRV-A (37% and HRV-B (11%. Infection with other respiratory viruses occurred in 20/128 (16% of HRV-positive children and in 26/92 (28% of HRV-negative samples. Conclusion HRV may be the commonest viral infection in young South African children with acute wheezing. Infection is associated with mild or moderate clinical disease.

  11. Assessment of locomotion behavior in adult Zebrafish after acute exposure to different pharmacological reference compounds

    Directory of Open Access Journals (Sweden)

    Pankaj Gupta

    2014-01-01

    Full Text Available Objectives: The objective of the present study was to assess locomotor behavior of adult zebrafish after acute exposure to different pharmacological reference compounds. Materials and Methods: Adult zebrafish of 4-5-months-old were exposed to different concentrations of known reference compounds for 15 min. The test was conducted separately for each drug concentration as well as control. Locomotor activity parameters viz. distance travelled, speed, total mobile time, and total immobile time were recorded for each animal during the exposure period. Results: Out of 11 compounds tested, nine compounds showed decrease in locomotor behavior with significant changes in distance travelled, speed, total mobile time, and total immobile time. Caffeine exhibited biphasic response in locomotion behavior, while scopolamine failed to induce any significant changes. Conclusion: In view of the above findings, these results suggested that exposure of adult zebrafish with different known compounds produce the expected changes in the locomotion behavior; therefore, adult zebrafish can be used an alternative approach for the assessment of new chemical entities for their effect on locomotor behavior.

  12. ACUTE NEUROTOXIC EFFECTS OF INHALED PERCHLOROETHYLENE ON PATTERN VISUAL EVOKED POTENTIALS AS A FUNCTION OF EXPOSURE AND ESTIMATED BLOOD AND BRAIN CONCENTRATION.

    Science.gov (United States)

    Previous experiments have shown the effects of acute inhalation exposure to trichloroethylene (TCE) and toluene are related to the target tissue concentration at the time of testing. The current studies examined exposure to another volatile organic compound, perchloroethylene (P...

  13. ACUTE NEUROTOXIC EFFECTS OF INHALED PERCHLOROETHYLENE ON PATTERN VISUAL EVOKED POTENTIALS AS A FUNCTION OF EXPOSURE AND ESTIMATED BLOOD AND BRAIN CONCENTRATION.

    Science.gov (United States)

    Previous experiments have shown the effects of acute inhalation exposure to trichloroethylene (TCE) and toluene are related to the target tissue concentration at the time of testing. The current studies examined exposure to another volatile organic compound, perchloroethylene (P...

  14. Human Exposure and Health Effects of Inorganic and Elemental Mercury

    Science.gov (United States)

    Zheng, Wei

    2012-01-01

    Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability of 7% to 15% after ingestion; they are also irritants and cause gastrointestinal symptoms. Upon entering the body, inorganic mercury compounds are accumulated mainly in the kidneys and produce kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. Elemental mercury from ingestion is poorly absorbed with a bioavailability of less than 0.01%. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood-brain barrier, while inorganic mercury compounds are not lipid soluble, rendering them unable to cross the blood-brain barrier. Elemental mercury may also enter the brain from the nasal cavity through the olfactory pathway. The blood mercury is a useful biomarker after short-term and high-level exposure, whereas the urine mercury is the ideal biomarker for long-term exposure to both elemental and inorganic mercury, and also as a good indicator of body burden. This review discusses the common sources of mercury exposure, skin lightening products containing mercury and mercury release from dental amalgam filling, two issues that happen in daily life, bear significant public health importance, and yet undergo extensive debate on their safety. PMID:23230464

  15. Impact of Hot and Cold Exposure on Human Skeletal Muscle Gene Expression

    Science.gov (United States)

    Zak, Roksana B.; Shute, Robert J.; Heesch, Matthew W.S.; La Salle, D. Taylor; Bubak, Matthew P.; Dinan, Nicholas E.; Laursen, Terence L.; Slivka, Dustin R.

    2017-01-01

    Many human diseases lead to a loss of skeletal muscle metabolic function and mass. Local and environmental temperature can modulate the exercise-stimulated response of several genes involved in mitochondrial biogenesis and skeletal muscle function in a human model. However, the impact of environmental temperature, independent of exercise, has not been addressed in a human model. Thus, the purpose of this study was to compare the effects of exposure to hot, cold, and room temperature conditions on skeletal muscle gene expression related to mitochondrial biogenesis and muscle mass. METHODS Recreationally trained male subjects (n=12) had muscle biopsies taken from the vastus lateralis before and after 3 h exposure to hot (33 °C), cold (7 °C), or room temperature (20 °C) conditions. RESULTS Temperature had no effect on most of the genes related to mitochondrial biogenesis, myogenesis, or proteolysis (p > 0.05). Core temperature was significantly higher in hot and cold environments compared to room temperature (37.2 ± 0.1 °C, p = 0.001; 37.1 ± 0.1 °C, p = 0.013; 36.9 ± 0.1 °C, respectively). Whole body oxygen consumption was also significantly higher in hot and cold compared to room temperature (0.38 ± 0.01 L·min−1, p < 0.001; 0.52 ± 0.03 L·min−1, p < 0.001; 0.35 ± 0.01 L·min−1, respectively). CONCLUSIONS These data show that acute temperature exposure alone does not elicit significant changes in skeletal muscle gene expression. When considered in conjunction with previous research, exercise appears to be a necessary component to observe gene expression alterations between different environmental temperatures in humans. PMID:28177744

  16. The body weight loss during acute exposure to high-altitude hypoxia in sea level residents.

    Science.gov (United States)

    Ge, Ri-Li; Wood, Helen; Yang, Hui-Huang; Liu, Yi-Ning; Wang, Xiu-Juan; Babb, Tony

    2010-12-25

    Weight loss is frequently observed after acute exposure to high altitude. However, the magnitude and rate of weight loss during acute exposure to high altitude has not been clarified in a controlled prospective study. The present study was performed to evaluate weight loss at high altitude. A group of 120 male subjects [aged (32±6) years] who worked on the construction of the Golmud-Lhasa Railway at Kunlun Mountain (altitude of 4 678 m) served as volunteer subjects for this study. Eighty-five workers normally resided at sea level (sea level group) and 35 normally resided at an altitude of 2 200 m (moderate altitude group). Body weight, body mass index (BMI), and waist circumference were measured in all subjects after a 7-day stay at Golmud (altitude of 2 800 m, baseline measurements). Measurements were repeated after 33-day working on Kunlun Mountain. In order to examine the daily rate of weight loss at high altitude, body weight was measured in 20 subjects from the sea level group (sea level subset group) each morning before breakfast for 33 d at Kunlun Mountain. According to guidelines established by the Lake Louise acute mountain sickness (AMS) consensus report, each subject completed an AMS self-report questionnaire two days after arriving at Kunlun Mountain. After 33-day stay at an altitude of 4 678 m, the average weight loss for the sea level group was 10.4% (range 6.5% to 29%), while the average for the moderate altitude group was 2.2% (-2% to 9.1%). The degree of weight loss (Δ weight loss) after a 33-day stay at an altitude of 4 678 m was significantly correlated with baseline body weight in the sea level group (r=0.677, P0.05). In the sea level subset group, a significant weight loss was observed within 20 d, but the weight remained stable thereafter. AMS-score at high altitude was significantly higher in the sea level group (4.69±2.48) than that in the moderate altitude group (2.97±1.38), and was significantly correlated with baseline body weight

  17. Prenatal Exposure to Progesterone Affects Sexual Orientation in Humans.

    Science.gov (United States)

    Reinisch, June M; Mortensen, Erik Lykke; Sanders, Stephanie A

    2017-07-01

    Prenatal sex hormone levels affect physical and behavioral sexual differentiation in animals and humans. Although prenatal hormones are theorized to influence sexual orientation in humans, evidence is sparse. Sexual orientation variables for 34 prenatally progesterone-exposed subjects (17 males and 17 females) were compared to matched controls (M age = 23.2 years). A case-control double-blind design was used drawing on existing data from the US/Denmark Prenatal Development Project. Index cases were exposed to lutocyclin (bioidentical progesterone = C21H30O2; M W : 314.46) and no other hormonal preparation. Controls were matched on 14 physical, medical, and socioeconomic variables. A structured interview conducted by a psychologist and self-administered questionnaires were used to collect data on sexual orientation, self-identification, attraction to the same and other sex, and history of sexual behavior with each sex. Compared to the unexposed, fewer exposed males and females identified as heterosexual and more of them reported histories of same-sex sexual behavior, attraction to the same or both sexes, and scored higher on attraction to males. Measures of heterosexual behavior and scores on attraction to females did not differ significantly by exposure. We conclude that, regardless of sex, exposure appeared to be associated with higher rates of bisexuality. Prenatal progesterone may be an underappreciated epigenetic factor in human sexual and psychosexual development and, in light of the current prevalence of progesterone treatment during pregnancy for a variety of pregnancy complications, warrants further investigation. These data on the effects of prenatal exposure to exogenous progesterone also suggest a potential role for natural early perturbations in progesterone levels in the development of sexual orientation.

  18. Modified Lipoproteins by Acrylamide Showed More Atherogenic Properties and Exposure of Acrylamide Induces Acute Hyperlipidemia and Fatty Liver Changes in Zebrafish.

    Science.gov (United States)

    Kim, Seong-Min; Baek, Ji-Mi; Lim, So-Mang; Kim, Jae-Yong; Kim, Jihoe; Choi, Inho; Cho, Kyung-Hyun

    2015-10-01

    Acrylamide is a well-known potent carcinogen and neurotoxin that, until now, has not been sufficiently investigated with regard to its effects on lipid metabolism. We investigated physiological effects of acrylamide (AA) on lipoprotein metabolism using human macrophages, dermal cells, and zebrafish models. Functional and structural properties of lipoproteins were modified by AA (final concentration of 5-100 mM) with loss of antioxidant ability and multimerization of apoA-I in vitro. AA exacerbated LDL oxidation, degradation, and LDL uptake into macrophages with increased ROS production. In human cells, treatment of AA (1-100 μM) caused cellular senescence of dermal cells with severe cytotoxicity. Waterborne exposure of zebrafish in cage water containing AA (300 ppm) resulted in acute death within 26 h along with elevation of body weight, blood glucose, triglyceride, and hepatic inflammation. AA exposure caused fat accumulation in liver in a dose-dependent manner. In conclusion, AA affected lipoprotein metabolism to result exacerbation of atherosclerosis. Exposure of zebrafish to AA resulted in acute inflammatory death with hyperlipidemia.

  19. Large organic aerosols in a human exposure chamber : Applications in occupational dermatology and lung medicine

    OpenAIRE

    Lundgren, Lennart

    2006-01-01

    Exposure to large organic aerosol particles may cause respiratory and skin reactions. The use of human exposure chambers offers possibilities for experimental exposure challenges carried out with patients, in research and for investigations of the effects of exposure on the skin and in the respiratory tract. The present aim was to study the performance of modern human whole-body exposure chambers during generation of large organic particles, and to develop and test new me...

  20. Soil is an important pathway of human lead exposure.

    OpenAIRE

    Mielke, H W; Reagan, P L

    1998-01-01

    This review shows the equal or greater importance of leaded gasoline-contaminated dust compared to lead-based paint to the child lead problem, and that soil lead, resulting from leaded gasoline and pulverized lead-based paint, is at least or more important than lead-based paint (intact and not pulverized) as a pathway of human lead exposure. Because lead-based paint is a high-dose source, the biologically relevant dosage is similar to lead in soil. Both lead-based paint and soil lead are asso...

  1. Soil is an important pathway of human lead exposure.

    OpenAIRE

    Mielke, H W; Reagan, P L

    1998-01-01

    This review shows the equal or greater importance of leaded gasoline-contaminated dust compared to lead-based paint to the child lead problem, and that soil lead, resulting from leaded gasoline and pulverized lead-based paint, is at least or more important than lead-based paint (intact and not pulverized) as a pathway of human lead exposure. Because lead-based paint is a high-dose source, the biologically relevant dosage is similar to lead in soil. Both lead-based paint and soil lead are asso...

  2. Inhibition of Acute in vivo Human Immunodeficiency Virus Infection by Human Interleukin 10 Treatment of SCID Mice Implanted with Human Fetal Thymus and Liver

    Science.gov (United States)

    Kollmann, Tobias R.; Pettoello-Mantovani, Massimo; Katopodis, Nikos F.; Hachamovitch, Moshe; Rubinstein, Arye; Kim, Ana; Goldstein, Harris

    1996-04-01

    To improve the usefulness of in vivo models for the investigation of the pathophysiology of human immunodeficiency virus (HIV) infection, we modified the construction of SCID mice implanted with human fetal thymus and liver (thy/liv-SCID-hu mice) so that the peripheral blood of the mice contained significant numbers of human monocytes and T cells. After inoculation with HIV-159, a primary patient isolate capable of infecting monocytes and T cells, the modified thy/liv-SCID-hu mice developed disseminated HIV infection that was associated with plasma viremia. The development of plasma viremia and HIV infection in thy/liv-SCID-hu mice inoculated with HIV-159 was inhibited by acute treatment with human interleukin (IL) 10 but not with human IL-12. The human peripheral blood mononuclear cells in these modified thy/liv-SCID-hu mice were responsive in vivo to treatment with exogenous cytokines. Human interferon γ expression in the circulating human peripheral blood mononuclear cells was induced by treatment with IL-12 and inhibited by treatment with IL-10. Thus, these modified thy/liv-SCID-hu mice should prove to be a valuable in vivo model for examining the role of immunomodulatory therapy in modifying HIV infection. Furthermore, our demonstration of the in vivo inhibitory effect of IL-10 on acute HIV infection suggests that further studies may be warranted to evaluate whether there is a role for IL-10 therapy in preventing HIV infection in individuals soon after exposure to HIV such as for children born to HIV-infected mothers.

  3. A case of acute psychosis in a patient following exposure to a single high dose of styrene.

    Science.gov (United States)

    Moon, Eunsoo; Suh, Hwagyu; Lee, Byung Dae; Park, Je Min; Lee, Young Min; Jeong, Hee Jeong

    2015-09-01

    We report a case of acute psychotic symptoms following exposure to a single high dose of styrene monomer. The 24-year-old male patient showed psychotic and cognitive symptoms immediately after exposure. His psychotic symptoms included auditory hallucinations and delusions of reference. Brain magnetic resonance imaging, electroencephalography, and laboratory examinations were performed to evaluate any other causes. The clinical, neuroimaging, and laboratory review in this case suggested that the suddenly developed psychotic symptoms that led to chronic deterioration were caused by the single exposure to styrene monomer. This is the first recent report in which acute psychotic symptoms developed from a single high dose of styrene suffocation compared with previous findings showing symptoms because of long-term low-dose exposure.

  4. Impact of global Fxr deficiency on experimental acute pancreatitis and genetic variation in the FXR locus in human acute pancreatitis.

    Directory of Open Access Journals (Sweden)

    Rian M Nijmeijer

    Full Text Available Infectious complications often occur in acute pancreatitis, related to impaired intestinal barrier function, with prolonged disease course and even mortality as a result. The bile salt nuclear receptor farnesoid X receptor (FXR, which is expressed in the ileum, liver and other organs including the pancreas, exhibits anti-inflammatory effects by inhibiting NF-κB activation and is implicated in maintaining intestinal barrier integrity and preventing bacterial overgrowth and translocation. Here we explore, with the aid of complementary animal and human experiments, the potential role of FXR in acute pancreatitis.Experimental acute pancreatitis was induced using the CCK-analogue cerulein in wild-type and Fxr-/- mice. Severity of acute pancreatitis was assessed using histology and a semi-quantitative scoring system. Ileal permeability was analyzed in vitro by Ussing chambers and an in vivo permeability assay. Gene expression of Fxr and Fxr target genes was studied by quantitative RT-PCR. Serum FGF19 levels were determined by ELISA in acute pancreatitis patients and healthy volunteers. A genetic association study in 387 acute pancreatitis patients and 853 controls was performed using 9 tagging single nucleotide polymorphisms (SNPs covering the complete FXR gene and two additional functional SNPs.In wild-type mice with acute pancreatitis, ileal transepithelial resistance was reduced and ileal mRNA expression of Fxr target genes Fgf15, SHP, and IBABP was decreased. Nevertheless, Fxr-/- mice did not exhibit a more severe acute pancreatitis than wild-type mice. In patients with acute pancreatitis, FGF19 levels were lower than in controls. However, there were no associations of FXR SNPs or haplotypes with susceptibility to acute pancreatitis, or its course, outcome or etiology.We found no evidence for a major role of FXR in acute human or murine pancreatitis. The observed altered Fxr activity during the course of disease may be a secondary phenomenon.

  5. Deoxynivalenol Exposure in Norway, Risk Assessments for Different Human Age Groups

    Science.gov (United States)

    Sundheim, Leif; Lillegaard, Inger Therese; Fæste, Christiane Kruse; Brantsæter, Anne-Lise; Brodal, Guro; Eriksen, Gunnar Sundstøl

    2017-01-01

    Deoxynivalenol (DON) is the most common mycotoxin in Norwegian cereals, and DON is detected in most samples of crude cereal grain and cereal food commodities such as flour, bran, and oat flakes. The Norwegian Scientific Committee for Food Safety assessed the risk for adverse effects of deoxynivalenol (DON) in different age groups of the domestic population. This review presents the main results from the risk assessment, supplemented with some recently published data. Impairment of the immune system together with reduced feed intake and weight gain are the critical effects of DON in experimental animals on which the current tolerable daily intake was established. Based on food consumption and occurrence data, the mean exposure to DON in years with low and high levels of DON in the flour, respectively, were in the range of or up to two times the Tolerable Daily Intake (TDI) in 1-year-old infants and 2-year-old children. In years with high mean DON concentration, the high (95th-percentile) exposure exceeded the TDI by up to 3.5 times in 1-, 2- , 4-, and 9-year-old children. The assessment concluded that exceeding the TDI in infants and children is of concern. The estimated dietary DON intakes in adolescent and adult populations are in the range of the TDI or below, and are not a health concern. Acute human exposure to DON is not of concern in any age group. PMID:28165414

  6. Deoxynivalenol Exposure in Norway, Risk Assessments for Different Human Age Groups

    Directory of Open Access Journals (Sweden)

    Leif Sundheim

    2017-02-01

    Full Text Available Deoxynivalenol (DON is the most common mycotoxin in Norwegian cereals, and DON is detected in most samples of crude cereal grain and cereal food commodities such as flour, bran, and oat flakes. The Norwegian Scientific Committee for Food Safety assessed the risk for adverse effects of deoxynivalenol (DON in different age groups of the domestic population. This review presents the main results from the risk assessment, supplemented with some recently published data. Impairment of the immune system together with reduced feed intake and weight gain are the critical effects of DON in experimental animals on which the current tolerable daily intake was established. Based on food consumption and occurrence data, the mean exposure to DON in years with low and high levels of DON in the flour, respectively, were in the range of or up to two times the Tolerable Daily Intake (TDI in 1-year-old infants and 2-year-old children. In years with high mean DON concentration, the high (95th-percentile exposure exceeded the TDI by up to 3.5 times in 1-, 2- , 4-, and 9-year-old children. The assessment concluded that exceeding the TDI in infants and children is of concern. The estimated dietary DON intakes in adolescent and adult populations are in the range of the TDI or below, and are not a health concern. Acute human exposure to DON is not of concern in any age group.

  7. Environmental pathways and human exposure to manganese in southern Brazil

    Directory of Open Access Journals (Sweden)

    NADIR HERMES

    2013-01-01

    Full Text Available The study of environmental pathways and human exposure to Manganese (Mn in Southern Brazil was performed using two steps. The first step consisted of taking water samples from the surface of the Pardinho River. The average results from this technique showed a significant increase of pollutants, including increased levels of Mn, above the environmentally acceptable standard recommended by the Brazilian National Environment Council. Additionally, 64 soil samples were taken from areas with and without agricultural activity. Many results were above the mean crust and did not indicate significant differences of Mn levels between the sampled areas. For the second step, 12 families were selected and assessed for exposure to Mn in a region with high levels of Mn in the soil. Most of the analyzed foods contained amounts of Mn above the reference values, indicating that food can be an important source of exposure. The Mn content from the hair of most subjects studied was also high compared to reference values from non-exposed populations. Although the contamination appeared to come from a natural origin, the results found in the present study showed that the Mn levels present in the Pardinho River Basin are a relevant public health issue.

  8. New approach for assessing human perfluoroalkyl exposure via hair.

    Science.gov (United States)

    Alves, Andreia; Jacobs, Griet; Vanermen, Guido; Covaci, Adrian; Voorspoels, Stefan

    2015-11-01

    In the recent years hair has been increasingly used as alternative matrix in human biomonitoring (HBM) of environmental pollutants. Sampling advantages and time integration of exposure assessment seems the most attractive features of hair matrix. In the current study, a novel miniaturized method was developed and validated for measuring 15 perfluoroalkyl substances (PFAS), including perfluoro n-butanoic acid (PFBA), perfluoro n-pentanoic acid (PFPeA), perfluoro n-hexanoic acid (PFHxA), perfluoro n-heptanoic acid (PFHpA), perfluor n-octanoic acid (PFOA), perfluoro n-nonanoic acid (PFNA), perfluoro tetradecanoic acid (PFTeDA), perfluorobutane sulfonic acid (PFBS), perfluoro pentane sulfonic acid (PFPeS), perfluorohexane sulfonic acid (PFHxS), perfluoroheptane sulfonic acid (PFHpS), perfluorooctane sulfonic acid (PFOS), perfluorononane sulfonic acid (PFNS), perfluorodecane sulfonic acid (PFDS) and perfluorododecane sulfonic acid (PFDoS) in human hair by liquid chromatography tandem mass spectrometry (LC-MS/MS). After extraction using ethyl acetate, dispersive ENVI-Carb was used for clean-up. Good intra- and inter-day precision for low (LQ 5 ng/g hair) and high spike (HQ 15n g/g) levels were achieved (in general RSD hair and 3-13 pg/g hair, respectively. The method limit of quantification (LOQm) ranged between 6 and 301 pg/g hair. The PFAS levels were measured in 30 human hair samples indicating that the levels are low (14-1534 pg/g hair). Some PFAS were not present in any hair sample (e.g. PFHpA, PFTeDA, PFNA, PFPeS, PFHpS, PFOS and PFNS), while other PFAS were frequently detected (PFBA, PFPeA, PFHxA, PFOA, PFBS, PFHxS, PFOS, PFDS and PFDoS) in human hair. Although levels in general were low, there is evidence of higher human exposure to some analytes, such as PFBA, PFPeA, PFHxA, PFOA, PFBS, PFHxS, and PFDoS. The current study shows that hair is a suitable alternative non-invasive matrix for exposure assessment of PFAS.

  9. Comprehensive analysis of the renal transcriptional response to acute uranyl nitrate exposure

    Directory of Open Access Journals (Sweden)

    Argiles Angel

    2006-01-01

    Full Text Available Abstract Background Chemical and radiological toxicities related to uranium acute exposure have been widely studied in nuclear fuel workers and military personnel. It is well known that uranyl nitrate induces acute renal failure (ARF. However, the mechanisms of this metal-induced injury are not well defined at the molecular level. Results Renal function and histology were assessed in mice receiving uranyl nitrate (UN(+ and controls (UN(-. To identify the genomic response to uranium exposure, serial analysis gene expression (SAGE of the kidney was performed in both groups. Over 43,000 mRNA SAGE tags were sequenced. A selection of the differentially expressed transcripts was confirmed by real-time quantitative PCR and Western blotting. UN(+ animals developed renal failure and displayed the characteristic histological lesions of UN nephropathy. Of the >14,500 unique tags identified in both libraries, 224 had a modified expression level; they are known to participate in inflammation, ion transport, signal transduction, oxidative stress, apoptosis, metabolism, and catabolism. Several genes that were identified had not previously been evaluated within the context of toxic ARF such as translationally controlled tumor protein, insulin like growth factor binding protein 7 and ribosomal protein S29, all apoptosis related genes. Conclusion We report a comprehensive description of the UN induced modifications in gene expression levels, including the identification of genes previously unrelated to ARF. The study of these genes and the metabolisms they control should improve our understanding of toxic ARF and enlighten on the molecular targets for potential therapeutic interventions.

  10. Acute activation, desensitization and smoldering activation of human acetylcholine receptors.

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    Barbara G Campling

    Full Text Available The behavioral effects of nicotine and other nicotinic agonists are mediated by AChRs in the brain. The relative contribution of acute activation versus chronic desensitization of AChRs is unknown. Sustained "smoldering activation" occurs over a range of agonist concentrations at which activated and desensitized AChRs are present in equilibrium. We used a fluorescent dye sensitive to changes in membrane potential to examine the effects of acute activation and chronic desensitization by nicotinic AChR agonists on cell lines expressing human α4β2, α3β4 and α7 AChRs. We examined the effects of acute and prolonged application of nicotine and the partial agonists varenicline, cytisine and sazetidine-A on these AChRs. The range of concentrations over which nicotine causes smoldering activation of α4β2 AChRs was centered at 0.13 µM, a level found in smokers. However, nicotine produced smoldering activation of α3β4 and α7 AChRs at concentrations well above levels found in smokers. The α4β2 expressing cell line contains a mixture of two stoichiometries, namely (α4β22β2 and (α4β22α4. The (α4β22β2 stoichiometry is more sensitive to activation by nicotine. Sazetidine-A activates and desensitizes only this stoichiometry. Varenicline, cytisine and sazetidine-A were partial agonists on this mixture of α4β2 AChRs, but full agonists on α3β4 and α7 AChRs. It has been reported that cytisine and varenicline are most efficacious on the (α4β22α4 stoichiometry. In this study, we distinguish the dual effects of activation and desensitization of AChRs by these nicotinic agonists and define the range of concentrations over which smoldering activation can be sustained.

  11. Effect of zinc sacrificial anode degradation on the defence system of the Pacific oyster, Crassostrea gigas: chronic and acute exposures.

    Science.gov (United States)

    Mottin, Elmina; Caplat, Christelle; Latire, Thomas; Mottier, Antoine; Mahaut, Marie-Laure; Costil, Katherine; Barillier, Daniel; Lebel, Jean-Marc; Serpentini, Antoine

    2012-09-01

    Two types of exposures were performed to assess the effects of zinc released from sacrificial anode degradation: a chronic exposure, in which oysters were exposed to 0.53±0.04 mg Zn L(-1) for 10 weeks, and an acute exposure, where oysters were exposed to 10.2±1.2 mg Zn L(-1) for 1 week. At the end of the acute exposure experiment, 81.8% mortality was recorded. In contrast, no mortality was detected after 10 weeks exposure. Moreover, all of the immune system biomarkers studied, except the number of circulating haemocytes, were stimulated by a moderate level of zinc and inhibited by a high level. Our exposure conditions did not induce SOD or MXR mRNA expression in gills and digestive gland. However, an increase of MT mRNA is observed in these tissues. The results indicate that oysters are sensitive to acute zinc toxicity but are only moderately affected by a mild zinc concentration.

  12. Human immunodeficiency virus seroconversion presenting with acute inflammatory demyelinating polyneuropathy: a case report

    OpenAIRE

    Sloan Derek J; Nicolson Andrew; Miller Alastair RO; Beeching Nick J; Beadsworth Mike BJ

    2008-01-01

    Abstract Introduction Acute Human Immunodeficiency Virus infection is associated with a range of neurological conditions. Guillain-Barré syndrome is a rare presentation; acute inflammatory demyelinating polyneuropathy is the commonest form of Guillain-Barré syndrome. Acute inflammatory demyelinating polyneuropathy has occasionally been reported in acute Immunodeficiency Virus infection but little data exists on frequency, management and outcome. Case presentation We describe an episode of Gui...

  13. Maternal metallothionein and zinc after acute ethanol exposure during gestation in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Harris, J.E. (Univ. of Kansas, Kansas City (United States))

    1992-02-26

    Acute exposure of the rat fetus to ethanol at critical periods can cause growth retardation and brain damage; the mechanism(s) is not known. Ethanol may cause redistribution of maternal zinc which results in fetal zinc deficiency and subsequent interruption of growth and development. The purpose was to determine if acute ethanol administration to the pregnant rat alters Zn and the Zn binding protein metallothionein (MT) in selected tissues. On gestational day (gd) 14, eighteen pregnant Sprague-Dawley rats were divided into groups. By intragastric tube, ethanol treated dams were given ethanol and pairfed controls were given a 0.85% NaCl solution. On gd 15, intragastric feedings were repeated. Throughout, the Lieber-DeCarli control diet was fed (adlibitum to untreated controls and ethanol treated dams and in appropriate quantities to pair fed controls). Blood ethanol concentrations at 90 minutes after the ethanol dose were 154 {plus minus} 46 and 265 {plus minus} 110 mg% on gd 14 and 15, respectively.

  14. MR-visible brain water content in human acute stroke

    DEFF Research Database (Denmark)

    Gideon, P; Rosenbaum, S; Sperling, B

    1999-01-01

    Quantification of metabolite concentrations by proton magnetic resonance spectroscopy (1H-MRS) in the human brain using water as an internal standard is based on the assumption that water content does not change significantly in pathologic brain tissue. To test this, we used 1H-MRS to estimate...... brain water content during the course of cerebral infarction. Measurements were performed serially in the acute, subacute, and chronic phase of infarction. Fourteen patients with acute cerebral infarction were examined as well as 9 healthy controls. To correlate with regional cerebral blood flow (r......CBF from Day 0-3 to Day 4-7 (p = 0.050) and from Day 0-3 to Day 8-21 (p = 0.028). No correlation between rCBF and water content was found. Water content in ischemic brain tissue increased significantly between Day 4-7 after stroke. This should be considered when performing quantitative 1H-MRS using water...

  15. Human Motor Cortex Functional Changes in Acute Stroke: Gender Effects

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    Vincenzo eDi Lazzaro

    2016-01-01

    Full Text Available The acute phase of stroke is accompanied by functional changes in the activity and interplay of both hemispheres. In healthy subjects, gender is known to impact the functional brain organization.We investigated whether gender influences also acute stroke functional changes. In thirty-five ischemic stroke patients, we evaluated the excitability of the affected (AH and unaffected hemisphere (UH by measuring resting and active motor threshold and motor-evoked potential amplitude under baseline conditions and after intermittent theta burst stimulation (iTBS of AH. We also computed an index of the excitability balance between the hemispheres, laterality indexes (LI, to evidence hemispheric asymmetry. Active motor threshold differed significantly between AH and UH only in the male group (p=0.004, not in females (p>0.200, and both LIAMT and LIRMT were significantly higher in males than in females (respectively p=0.033 and p=0.042. LTP-like activity induced by iTBS in AH was more frequent in females. Gender influences the functional excitability changes that take place after human stroke and the level of LTP that can be induced by repetitive stimulation. This knowledge is of high value in the attempt of individualizing to different genders any non-invasive stimulation strategy designed to foster stroke recovery.

  16. MR-visible brain water content in human acute stroke

    DEFF Research Database (Denmark)

    Gideon, P; Rosenbaum, S; Sperling, B;

    1999-01-01

    Quantification of metabolite concentrations by proton magnetic resonance spectroscopy (1H-MRS) in the human brain using water as an internal standard is based on the assumption that water content does not change significantly in pathologic brain tissue. To test this, we used 1H-MRS to estimate...... brain water content during the course of cerebral infarction. Measurements were performed serially in the acute, subacute, and chronic phase of infarction. Fourteen patients with acute cerebral infarction were examined as well as 9 healthy controls. To correlate with regional cerebral blood flow (r......CBF from Day 0-3 to Day 4-7 (p = 0.050) and from Day 0-3 to Day 8-21 (p = 0.028). No correlation between rCBF and water content was found. Water content in ischemic brain tissue increased significantly between Day 4-7 after stroke. This should be considered when performing quantitative 1H-MRS using water...

  17. Human exposure to arsenic in groundwater from Lahore district, Pakistan.

    Science.gov (United States)

    Bibi, Mehwish; Hashmi, Muhammad Zaffar; Malik, Riffat Naseem

    2015-01-01

    In the present study we determined As concentrations in healthy volunteers from three different age groups (children, adults and old age) residing in Lahore, Pakistan to gain insight into arsenic exposure to humans via drinking water. The results revealed that the concentrations of As were significantly (p<0.05) different among different sites, while non significant trends were observed among different age classes. As concentrations in blood and nails samples showed a significant (p<0.05) positive correlation. The mean concentrations of As were higher in nails samples (1.43μg/g) followed by blood samples (1.15μg/L); urine samples (0.82μg/l) and hair samples (0.74μg/g) based on all sites. The antioxidants enzyme activities in blood samples showed a significant (p<0.01) decrease with the increase in As concentrations. The result suggests that urgent action is needed to prevent further human exposure to As.

  18. Human exposure to soil contaminants in subarctic Ontario, Canada

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    Ellen Stephanie Reyes

    2015-05-01

    Full Text Available Background: Chemical contaminants in the Canadian subarctic present a health risk with exposures primarily occurring via the food consumption. Objective: Characterization of soil contaminants is needed in northern Canada due to increased gardening and agricultural food security initiatives and the presence of known point sources of pollution. Design: A field study was conducted in the western James Bay Region of Ontario, Canada, to examine the concentrations of polychlorinated biphenyls, dichlorodiphenyltrichloroethane and its metabolites (ΣDDT, other organochlorines, and metals/metalloids in potentially contaminated agriculture sites. Methods: Exposure pathways were assessed by comparing the estimated daily intake to acceptable daily intake values. Ninety soil samples were collected at random (grid sampling from 3 plots (A, B, and C in Fort Albany (on the mainland, subarctic Ontario, Canada. The contaminated-soil samples were analysed by gas chromatography with an electron capture detector or inductively coupled plasma mass spectrometer. Results: The range of ΣDDT in 90 soil samples was below the limit of detection to 4.19 mg/kg. From the 3 soil plots analysed, Plot A had the highest ΣDDT mean concentration of 1.12 mg/kg, followed by Plot B and Plot C which had 0.09 and 0.01 mg/kg, respectively. Concentrations of other organic contaminants and metals in the soil samples were below the limit of detection or found in low concentrations in all plots and did not present a human health risk. Conclusions: Exposure analyses showed that the human risk was below regulatory thresholds. However, the ΣDDT concentration in Plot A exceeded soil guidelines set out by the Canadian Council of Ministers of the Environment of 0.7 mg/kg, and thus the land should not be used for agricultural or recreational purposes. Both Plots B and C were below threshold limits, and this land can be used for agricultural purposes.

  19. Nonvisual responses to light exposure in the human brain during the circadian night.

    Science.gov (United States)

    Perrin, Fabien; Peigneux, Philippe; Fuchs, Sonia; Verhaeghe, Stéphane; Laureys, Steven; Middleton, Benita; Degueldre, Christian; Del Fiore, Guy; Vandewalle, Gilles; Balteau, Evelyne; Poirrier, Robert; Moreau, Vincent; Luxen, André; Maquet, Pierre; Dijk, Derk-Jan

    2004-10-26

    The brain processes light information to visually represent the environment but also to detect changes in ambient light level. The latter information induces non-image-forming responses and exerts powerful effects on physiology such as synchronization of the circadian clock and suppression of melatonin. In rodents, irradiance information is transduced from a discrete subset of photosensitive retinal ganglion cells via the retinohypothalamic tract to various hypothalamic and brainstem regulatory structures including the hypothalamic suprachiasmatic nuclei, the master circadian pacemaker. In humans, light also acutely modulates alertness, but the cerebral correlates of this effect are unknown. We assessed regional cerebral blood flow in 13 subjects attending to auditory and visual stimuli in near darkness following light exposures (>8000 lux) of different durations (0.5, 17, 16.5, and 0 min) during the biological night. The bright broadband polychromatic light suppressed melatonin and enhanced alertness. Functional imaging revealed that a large-scale occipito-parietal attention network, including the right intraparietal sulcus, was more active in proportion to the duration of light exposures preceding the scans. Activity in the hypothalamus decreased in proportion to previous illumination. These findings have important implications for understanding the effects of light on human behavior.

  20. Acute Human Inkoo and Chatanga Virus Infections, Finland.

    Science.gov (United States)

    Putkuri, Niina; Kantele, Anu; Levanov, Lev; Kivistö, Ilkka; Brummer-Korvenkontio, Markus; Vaheri, Antti; Vapalahti, Olli

    2016-05-01

    Inkoo virus (INKV) and Chatanga virus (CHATV), which are circulating in Finland, are mosquitoborne California serogroup orthobunyaviruses that have a high seroprevalence among humans. Worldwide, INKV infection has been poorly described, and CHATV infection has been unknown. Using serum samples collected in Finland from 7,961 patients suspected of having viral neurologic disease or Puumala virus infection during the summers of 2001-2013, we analyzed the samples to detect California serogroup infections. IgM seropositivity revealed 17 acute infections, and cross-neutralization tests confirmed presence of INKV or CHATV infections. All children (<16 years of age) with INKV infection were hospitalized; adults were outpatients with mild disease, except for 1 who was hospitalized with CHATV infection. Symptoms included fever, influenza-like illness, nausea or vomiting, disorientation, nuchal rigidity, headache, drowsiness, and seizures. Although many INKV and CHATV infections appear to be subclinical, these viruses can cause more severe disease, especially in children.

  1. A rare cause of acute flaccid paralysis: Human coronaviruses

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    Cokyaman Turgay

    2015-01-01

    Full Text Available Acute flaccid paralysis (AFP is a life-threatening clinical entity characterized by weakness in the whole body muscles often accompanied by respiratory and bulbar paralysis. The most common cause is Gullian-Barre syndrome, but infections, spinal cord diseases, neuromuscular diseases such as myasthenia gravis, drugs and toxins, periodic hypokalemic paralysis, electrolyte disturbances, and botulism should be considered as in the differential diagnosis. Human coronaviruses (HCoVs cause common cold, upper and lower respiratory tract disease, but in the literature presentation with the lower respiratory tract infection and AFP has not been reported previously. In this study, pediatric case admitted with lower respiratory tract infection and AFP, who detected for HCoV 229E and OC43 co-infection by the real-time polymerase chain reaction, has been reported for the first time.

  2. Structural change of human hair induced by mercury exposure.

    Science.gov (United States)

    Xing, Xueqing; Du, Rong; Li, Yufeng; Li, Bai; Cai, Quan; Mo, Guang; Gong, Yu; Chen, Zhongjun; Wu, Zhonghua

    2013-10-01

    Mercury is one of the most hazardous pollutants in the environment. In this paper, the structural change of human hair induced by mercury exposure was studied. Human hair samples were, respectively, collected from the normal Beijing area and the Hg-contaminated Wanshan area of the Guizhou Province, China. Inductively coupled plasma mass spectroscopy was used to detect the element contents. A small angle X-ray scattering technique was used to probe the structural change. Three reflections with 8.8, 6.7, and 4.5 nm spacing were compared between the normal and the Hg-contaminated hair samples. The results confirm that the 4.5 nm reflection is from the ordered fibrillar structure of glycosaminoglycan (GAG) in proteoglycan (PG) that composes the matrix around the intermediate filaments. The increase of Ca content makes the regular oriented fibrillar structure of GAG transform to a random oriented one, broadening the angular extent of the reflection with 4.5 nm spacing. However, overdose Hg makes the core proteins where the ordered fibrils of GAG are attached become coiled, which destroys the ordered arrangements of fibrillar GAG in PG, resulting in the disappearance of the reflections with 4.5 nm spacing. The disappearance of the 4.5 nm reflection can be used as a bioindicator of overdose Hg contamination to the human body. A supercoiled-coil model of hair nanoscale structure and a possible mechanism of mercury effect in human hair are proposed in this paper.

  3. Gut Microbial Succession Follows Acute Secretory Diarrhea in Humans

    Science.gov (United States)

    David, Lawrence A.; Weil, Ana; Ryan, Edward T.; Calderwood, Stephen B.; Harris, Jason B.; Chowdhury, Fahima; Begum, Yasmin; Qadri, Firdausi

    2015-01-01

    ABSTRACT Disability after childhood diarrhea is an important burden on global productivity. Recent studies suggest that gut bacterial communities influence how humans recover from infectious diarrhea, but we still lack extensive data and mechanistic hypotheses for how these bacterial communities respond to diarrheal disease and its treatment. Here, we report that after Vibrio cholerae infection, the human gut microbiota undergoes an orderly and reproducible succession that features transient reversals in relative levels of enteric Bacteroides and Prevotella. Elements of this succession may be a common feature in microbiota recovery from acute secretory diarrhea, as we observed similar successional dynamics after enterotoxigenic Escherichia coli (ETEC) infection. Our metagenomic analyses suggest that multiple mechanisms drive microbial succession after cholera, including bacterial dispersal properties, changing enteric oxygen and carbohydrate levels, and phage dynamics. Thus, gut microbiota recovery after cholera may be predictable at the level of community structure but is driven by a complex set of temporally varying ecological processes. Our findings suggest opportunities for diagnostics and therapies targeting the gut microbiota in humans recovering from infectious diarrhea. PMID:25991682

  4. Sustained CD8+ T-cell responses induced after acute parvovirus B19 infection in humans

    DEFF Research Database (Denmark)

    Norbeck, Oscar; Isa, Adiba; Pöhlmann, Christoph

    2005-01-01

    Murine models have suggested that CD8+ T-cell responses peak early in acute viral infections and are not sustained, but no evidence for humans has been available. To address this, we longitudinally analyzed the CD8+ T-cell response to human parvovirus B19 in acutely infected individuals. We...... observed striking CD8+ T-cell responses, which were sustained or even increased over many months after the resolution of acute disease, indicating that CD8+ T cells may play a prominent role in the control of parvovirus B19 and other acute viral infections of humans, including potentially those generated...

  5. [Effect of training on treadmill performance, aerobic capacity and body reactions to acute cold exposure].

    Science.gov (United States)

    Iakushkin, A V; Akimov, E B; Andreev, R S; Kalenov, Iu N; Kozlov, A V; Kuznetsova, O V; Son'kin, V D

    2014-01-01

    An attempt was made to test the hypothesis that regular physical activity at the anaerobic threshold is able to stimulate an increase in the amount of body fat brown or beige, which can manifest itself in increasing lactate utilization during exercise and increase the reactivity in response to acute regional cooling. The methods used are: ramp test, regional acute cold exposure, measurement of gas exchange, lactate and glucose in the blood, heart rate, and heart rate variability, blood pressure and respiration variability at rest and during standard functional tests; infrared thermal imaging, statistical methods of results analysis. Workout 10 physically active volunteers (7 males and 3 females) on a treadmill at a speed corresponding to 75-80% of the persona VO2max for 30 minutes 3 times per week at a fixed ambient temperature 21-22°C for 6 weeks resulted in a significant (from 19 to 39%) increase in test work duration but VO2max on average changed little. The increase in power of anaerobic threshold was associated with a sharp slowdown in the accumulation of lactate in progress of ramp test. Lactate utilization rate during the recovery period, on the contrary, increased. In general, significantly increased work efficiency at a test load. Not revealed noticeable changes in the condition and response to a standard functional tests of autonomic systems, as judged by heart rate variability, blood pressure and respiration variability at rest and during orthostatic tests and imposed breathing rhythm. The functional response of the body to acute cold exposure (1 minute cooling of the feet in ice water) is not changed after a cycle of training--either in terms of metabolism (oxygen consumption, etc.), or the dynamics of the skin temperature in areas of most probable location of brown adipose tissue (BAT). These data do not confirm the previously expressed (2010) hypothesis about the function of BAT as a universal homeostatic instrument in the body. Probably, if under

  6. Chemokine co-receptor CCR5/CXCR4-dependent modulation of Kv2.1 channel confers acute neuroprotection to HIV-1 glycoprotein gp120 exposure.

    Directory of Open Access Journals (Sweden)

    Andrew J Shepherd

    Full Text Available Infection with human immunodeficiency virus-1 (HIV-1 within the brain has long been known to be associated with neurodegeneration and neurocognitive disorder (referred as HAND, a condition characterized in its early stages by declining cognitive function and behavioral disturbances. Mechanistically, the HIV-1 coat glycoprotein 120 (gp120 has been suggested to be a critical factor inducing apoptotic cell death in neurons via the activation of p38 mitogen-activated protein kinase (MAPK, upon chronic exposure to the virus. Here we show that acute exposure of neurons to HIV-1 gp120 elicits a homeostatic response, which provides protection against non-apoptotic cell death, involving the major somatodendritic voltage-gated K⁺ (Kv channel Kv2.1 as the key mediator. The Kv2.1 channel has recently been shown to provide homeostatic control of neuronal excitability under conditions of seizures, ischemia and neuromodulation/neuroinflammation. Following acute exposure to gp120, cultured rat hippocampal neurons show rapid dephosphorylation of the Kv2.1 protein, which ultimately leads to changes in specific sub-cellular localization and voltage-dependent channel activation properties of Kv2.1. Such modifications in Kv2.1 are dependent on the activation of the chemokine co-receptors CCR5 and CXCR4, and subsequent activation of the protein phosphatase calcineurin. This leads to the overall suppression of neuronal excitability and provides neurons with a homeostatic protective mechanism. Specific blockade of calcineurin and Kv2.1 channel activity led to significant enhancement of non-apoptotic neuronal death upon acute gp120 treatment. These observations shed new light on the intrinsic homeostatic mechanisms of neuronal resilience during the acute stages of neuro-HIV infections.

  7. Chemokine co-receptor CCR5/CXCR4-dependent modulation of Kv2.1 channel confers acute neuroprotection to HIV-1 glycoprotein gp120 exposure.

    Science.gov (United States)

    Shepherd, Andrew J; Loo, Lipin; Mohapatra, Durga P

    2013-01-01

    Infection with human immunodeficiency virus-1 (HIV-1) within the brain has long been known to be associated with neurodegeneration and neurocognitive disorder (referred as HAND), a condition characterized in its early stages by declining cognitive function and behavioral disturbances. Mechanistically, the HIV-1 coat glycoprotein 120 (gp120) has been suggested to be a critical factor inducing apoptotic cell death in neurons via the activation of p38 mitogen-activated protein kinase (MAPK), upon chronic exposure to the virus. Here we show that acute exposure of neurons to HIV-1 gp120 elicits a homeostatic response, which provides protection against non-apoptotic cell death, involving the major somatodendritic voltage-gated K⁺ (Kv) channel Kv2.1 as the key mediator. The Kv2.1 channel has recently been shown to provide homeostatic control of neuronal excitability under conditions of seizures, ischemia and neuromodulation/neuroinflammation. Following acute exposure to gp120, cultured rat hippocampal neurons show rapid dephosphorylation of the Kv2.1 protein, which ultimately leads to changes in specific sub-cellular localization and voltage-dependent channel activation properties of Kv2.1. Such modifications in Kv2.1 are dependent on the activation of the chemokine co-receptors CCR5 and CXCR4, and subsequent activation of the protein phosphatase calcineurin. This leads to the overall suppression of neuronal excitability and provides neurons with a homeostatic protective mechanism. Specific blockade of calcineurin and Kv2.1 channel activity led to significant enhancement of non-apoptotic neuronal death upon acute gp120 treatment. These observations shed new light on the intrinsic homeostatic mechanisms of neuronal resilience during the acute stages of neuro-HIV infections.

  8. Acute vertigo in an anesthesia provider during exposure to a 3T MRI scanner

    Directory of Open Access Journals (Sweden)

    Gorlin A

    2015-03-01

    Full Text Available Andrew Gorlin,1 Joseph M Hoxworth,2 William Pavlicek,2 Christopher A Thunberg,1 David Seamans1 1Department of Anesthesiology, 2Department of Radiology, Mayo Clinic Arizona, Phoenix, AZ, USA Abstract: Vertigo induced by exposure to the magnetic field of a magnetic resonance imaging (MRI scanner is a well-known phenomenon within the radiology community but is not widely appreciated by other clinical specialists. Here, we describe a case of an anesthetist experiencing acute vertigo while providing sedation to a patient undergoing a 3 Tesla MRI scan. After discussing previous reports, and the evidence surrounding MRI-induced vertigo, we review potential etiologies that include the effects of both static and time-varying magnetic fields on the vestibular apparatus. We conclude our review by discussing the occupational standards that exist for MRI exposure and methods to minimize the risks of MRI-induced vertigo for clinicians working in the MRI environment. Keywords: occupational medicine, MRI worker safety, vestibular dysfunction, magnetic field, 3T MRI scanner

  9. Performance, acute health symptoms and physiological responses during exposure to high air temperature and carbon dioxide concentration

    DEFF Research Database (Denmark)

    liu, weiwei; Zhong, Weidi; Wargocki, Pawel

    2017-01-01

    subjects to report feeling uncomfortably warm, to rate the air quality as worse, to report increased sleepiness and higher intensity of several acute health symptoms. Eardrum temperature, skin temperature, heart rate and body weight loss all increased significantly at this exposure, arterial oxygen...

  10. Impact of acute exposure to air pollution on the cardiorespiratory performance of military firemen

    Directory of Open Access Journals (Sweden)

    R.S. Oliveira

    2006-12-01

    Full Text Available The objective of the present study was to determine the impact of acute short-term exposure to air pollution on the cardiorespiratory performance of military fireman living and working in the city of Guarujá, São Paulo, Brazil. Twenty-five healthy non-smoking firemen aged 24 to 45 years had about 1 h of exposure to low and high levels of air pollution. The tests consisted of two phases: phase A, in Bertioga, a town with low levels of air pollution, and phase B, in Cubatão, a polluted town, with a 7-day interval between phases. The volunteers remained in the cities (Bertioga/Cubatão only for the time required to perform the tests. Cumulative load 10 ± 2 min-long exertion tests were performed on a treadmill, consisting of a 2-min stage at a load of 7 km/h, followed by increasing exertion of 1 km h-1 min-1 until the maximum individual limit. There were statistically significant differences (P < 0.05 in anaerobic threshold (AT between Cubatão (35.04 ± 4.91 mL kg-1 min-1 and Bertioga (36.98 ± 5.62 mL kg-1 min-1; P = 0.01, in the heart rate at AT (AT HR; Cubatão 152.08 ± 14.86 bpm, Bertioga 157.44 ± 13.64 bpm; P = 0.001, and in percent maximal oxygen consumption at AT (AT%VO2max; Cubatão 64.56 ± 6.55%, Bertioga 67.40 ± 5.35%; P = 0.03. However, there were no differences in VO2max, maximal heart rate or velocity at AT (ATvel observed in firemen between towns. The acute exposure to pollutants in Cubatão, SP, caused a significant reduction in the performance at submaximal levels of physical exertion.

  11. Effects of Acute Exposure to Moderate Altitude on Vascular Function, Metabolism and Systemic Inflammation

    Science.gov (United States)

    Stöwhas, Anne-Christin; Latshang, Tsogyal D.; Lo Cascio, Christian M.; Lautwein, Sina; Stadelmann, Katrin; Tesler, Noemi; Ayers, Lisa; Berneis, Kaspar; Gerber, Philipp A.; Huber, Reto; Achermann, Peter; Bloch, Konrad E.; Kohler, Malcolm

    2013-01-01

    Background Travel to mountain areas is popular. However, the effects of acute exposure to moderate altitude on the cardiovascular system and metabolism are largely unknown. Objectives To investigate the effects of acute exposure to moderate altitude on vascular function, metabolism and systemic inflammation. Methods In 51 healthy male subjects with a mean (SD) age of 26.9 (9.3) years, oxygen saturation, blood pressure, heart rate, arterial stiffness, lipid profiles, low density lipoprotein (LDL) particle size, insulin resistance (HOMA-index), highly-sensitive C-reactive protein and pro-inflammatory cytokines were measured at 490 m (Zurich) and during two days at 2590 m, (Davos Jakobshorn, Switzerland) in randomized order. The largest differences in outcomes between the two altitudes are reported. Results Mean (SD) oxygen saturation was significantly lower at 2590 m, 91.0 (2.0)%, compared to 490 m, 96.0 (1.0)%, p<0.001. Mean blood pressure (mean difference +4.8 mmHg, p<0.001) and heart rate (mean difference +3.3 bpm, p<0.001) were significantly higher at 2590 m, compared to 490 m, but this was not associated with increased arterial stiffness. At 2590 m, lipid profiles improved (median difference triglycerides −0.14 mmol/l, p = 0.012, HDL +0.08 mmol/l, p<0.001, total cholesterol/HDL-ratio −0.25, p = 0.001), LDL particle size increased (median difference +0.45 nm, p = 0.048) and hsCRP decreased (median difference −0.18 mg/l, p = 0.024) compared to 490 m. No significant change in pro-inflammatory cytokines or insulin resistance was observed upon ascent to 2590 m. Conclusions Short-term stay at moderate altitude is associated with increased blood pressure and heart rate likely due to augmented sympathetic activity. Exposure to moderate altitude improves the lipid profile and systemic inflammation, but seems to have no significant effect on glucose metabolism. Trial Registration ClinicalTrials.gov NCT01130948 PMID:23936377

  12. Effects of acute exposure to moderate altitude on vascular function, metabolism and systemic inflammation.

    Directory of Open Access Journals (Sweden)

    Anne-Christin Stöwhas

    Full Text Available BACKGROUND: Travel to mountain areas is popular. However, the effects of acute exposure to moderate altitude on the cardiovascular system and metabolism are largely unknown. OBJECTIVES: To investigate the effects of acute exposure to moderate altitude on vascular function, metabolism and systemic inflammation. METHODS: In 51 healthy male subjects with a mean (SD age of 26.9 (9.3 years, oxygen saturation, blood pressure, heart rate, arterial stiffness, lipid profiles, low density lipoprotein (LDL particle size, insulin resistance (HOMA-index, highly-sensitive C-reactive protein and pro-inflammatory cytokines were measured at 490 m (Zurich and during two days at 2590 m, (Davos Jakobshorn, Switzerland in randomized order. The largest differences in outcomes between the two altitudes are reported. RESULTS: Mean (SD oxygen saturation was significantly lower at 2590 m, 91.0 (2.0%, compared to 490 m, 96.0 (1.0%, p<0.001. Mean blood pressure (mean difference +4.8 mmHg, p<0.001 and heart rate (mean difference +3.3 bpm, p<0.001 were significantly higher at 2590 m, compared to 490 m, but this was not associated with increased arterial stiffness. At 2590 m, lipid profiles improved (median difference triglycerides -0.14 mmol/l, p=0.012, HDL +0.08 mmol/l, p<0.001, total cholesterol/HDL-ratio -0.25, p=0.001, LDL particle size increased (median difference +0.45 nm, p=0.048 and hsCRP decreased (median difference -0.18 mg/l, p=0.024 compared to 490 m. No significant change in pro-inflammatory cytokines or insulin resistance was observed upon ascent to 2590 m. CONCLUSIONS: Short-term stay at moderate altitude is associated with increased blood pressure and heart rate likely due to augmented sympathetic activity. Exposure to moderate altitude improves the lipid profile and systemic inflammation, but seems to have no significant effect on glucose metabolism. TRIAL REGISTRATION: ClinicalTrials.gov NCT01130948.

  13. Acute lung injury following inhalation exposure to nerve agent VX in guinea pigs.

    Science.gov (United States)

    Wright, Benjamin S; Rezk, Peter E; Graham, Jacob R; Steele, Keith E; Gordon, Richard K; Sciuto, Alfred M; Nambiar, Madhusoodana P

    2006-05-01

    A microinstillation technique of inhalation exposure was utilized to assess lung injury following chemical warfare nerve agent VX [methylphosphonothioic acid S-(2-[bis(1-methylethyl)amino]ethyl) O-ethyl ester] exposure in guinea pigs. Animals were anesthetized using Telazol-meditomidine, gently intubated, and VX was aerosolized using a microcatheter placed 2 cm above the bifurcation of the trachea. Different doses (50.4 microg/m3, 70.4 micro g/m(m3), 90.4 microg/m(m3)) of VX were administered at 40 pulses/min for 5 min. Dosing of VX was calculated by the volume of aerosol produced per 200 pulses and diluting the agent accordingly. Although the survival rate of animals exposed to different doses of VX was similar to the controls, nearly a 20% weight reduction was observed in exposed animals. After 24 h of recovery, the animals were euthanized and bronchoalveolar lavage (BAL) was performed with oxygen free saline. BAL was centrifuged and separated into BAL fluid (BALF) and BAL cells (BALC) and analyzed for indication of lung injury. The edema by dry/wet weight ratio of the accessory lobe increased 11% in VX-treated animals. BAL cell number was increased in VX-treated animals compared to controls, independent of dosage. Trypan blue viability assay indicated an increase in BAL cell death in 70.4 microg/m(m3) and 90.4 microg/m(m3) VX-exposed animals. Differential cell counting of BALC indicated a decrease in macrophage/monocytes in VX-exposed animals. The total amount of BAL protein increased gradually with the exposed dose of VX and was highest in animals exposed to 90.4 microg/m(m3), indicating that this dose of VX caused lung injury that persisted at 24 h. In addition, histopathology results also suggest that inhalation exposure to VX induces acute lung injury.

  14. Human exposure to soil contamination: a qualitative and quantitative analysis towards proposals for human toxicological intervention values (partly revised edition)

    NARCIS (Netherlands)

    Berg R van den; LBG

    1994-01-01

    In view of a revision of the Dutch Soil Protection act, proposals are presented in this report for human toxicologically based intervention values for soil and groundwater, calculated from human toxicological guideline values and human exposure. To this purpose the exposure model CSOIL is presented

  15. Chronic and acute exposures to the world trade center disaster and lower respiratory symptoms: area residents and workers.

    Science.gov (United States)

    Maslow, Carey B; Friedman, Stephen M; Pillai, Parul S; Reibman, Joan; Berger, Kenneth I; Goldring, Roberta; Stellman, Steven D; Farfel, Mark

    2012-06-01

    We assessed associations between new-onset (post-September 11, 2001 [9/11]) lower respiratory symptoms reported on 2 surveys, administered 3 years apart, and acute and chronic 9/11-related exposures among New York City World Trade Center-area residents and workers enrolled in the World Trade Center Health Registry. World Trade Center-area residents and workers were categorized as case participants or control participants on the basis of lower respiratory symptoms reported in surveys administered 2 to 3 and 5 to 6 years after 9/11. We created composite exposure scales after principal components analyses of detailed exposure histories obtained during face-to-face interviews. We used multivariate logistic regression models to determine associations between lower respiratory symptoms and composite exposure scales. Both acute and chronic exposures to the events of 9/11 were independently associated, often in a dose-dependent manner, with lower respiratory symptoms among individuals who lived and worked in the area of the World Trade Center. Study findings argue for detailed assessments of exposure during and after events in the future from which potentially toxic materials may be released and for rapid interventions to minimize exposures and screen for potential adverse health effects.

  16. Effects of acute exposure to WIFI signals (2.45GHz) on heart variability and blood pressure in Albinos rabbit.

    Science.gov (United States)

    Saili, Linda; Hanini, Amel; Smirani, Chiraz; Azzouz, Ines; Azzouz, Amina; Sakly, Mohsen; Abdelmelek, Hafedh; Bouslama, Zihad

    2015-09-01

    Electrocardiogram and arterial pressure measurements were studied under acute exposures to WIFI (2.45GHz) during one hour in adult male rabbits. Antennas of WIFI were placed at 25cm at the right side near the heart. Acute exposure of rabbits to WIFI increased heart frequency (+22%) and arterial blood pressure (+14%). Moreover, analysis of ECG revealed that WIFI induced a combined increase of PR and QT intervals. By contrast, the same exposure failed to alter maximum amplitude and P waves. After intravenously injection of dopamine (0.50ml/kg) and epinephrine (0.50ml/kg) under acute exposure to RF we found that, WIFI alter catecholamines (dopamine, epinephrine) action on heart variability and blood pressure compared to control. These results suggest for the first time, as far as we know, that exposure to WIFI affect heart rhythm, blood pressure, and catecholamines efficacy on cardiovascular system; indicating that radiofrequency can act directly and/or indirectly on cardiovascular system.

  17. Human dermal exposure to galaxolide from personal care products.

    Science.gov (United States)

    Correia, P; Cruz, A; Santos, L; Alves, A

    2013-06-01

    Musks are synthetic fragrances applied on personal care and household products as fixatives, by retarding the release of other fragrances with higher volatility. Galaxolide is the most used polycyclic musk since the 90th decade, and it has been detected in several environmental and biological matrices, particularly in human tissues and fluids. For exposure assessment purposes, large-monitoring data need to be obtained and rapid but reliable analytical techniques are requested. The main objective of this study is to develop and validate a new and fast analytical methodology to quantify galaxolide in personal care products and to apply this method to real matrices like skin care products (creams and lotions), shower products (soap bar), hair care products (shampoo and hair conditioner) and oral care products (toothpaste), to evaluate the human dermal exposure risk. A dispersive solid-phase extraction is proposed, using QuEChERS methodology, followed by HPLC with fluorescence detection. Some extraction parameters were studied, like the ratio of sample/solvent amounts, the homogenization time, the salt addition effect and the used sorbents. The validation parameters of the developed method were the following: a linearity range of 0.005-1.002 mg kg⁻¹ sample, a limit of detection of 0.001 mg kg⁻¹ sample, repeatability between 0.7% and 11.3% (variation coefficient of six standard injections), an intermediate precision of 2.5% (variation coefficient of six independent analysis of the same sample), mean recoveries ranging from 65% (soap bar) to 95% (body cream) and 3% of global uncertainty in most of the working range. The time of analysis, including the extraction steps, is 60 min, allowing a throughput of 4 samples h⁻¹ . Galaxolide was detected in all of the seven analysed products in concentrations ranging from 0.04 ± 0.01 mg kg⁻¹ sample (toothpaste) to 280.78 ± 8.19 mg kg⁻¹ sample (perfumed body cream), which may correspond to a significant estimated

  18. Prior exposure to capture heightens the corticosterone and behavioural responses of little penguins (Eudyptula minor) to acute stress.

    Science.gov (United States)

    Carroll, Gemma; Turner, Emma; Dann, Peter; Harcourt, Rob

    2016-01-01

    Studies of physiology can provide important insight into how animals are coping with challenges in their environment and can signal the potential effects of exposure to human activity in both the short and long term. In this study, we measured the physiological and behavioural response of little penguins (Eudyptula minor) that were naïve to human activity over 30 min of capture and handling. We assessed relationships between corticosterone secretion, behaviour, sex and time of day in order to characterize the determinants of the natural stress response. We then compared the response of these naïve penguins with the responses of female little penguins that had been exposed to research activity (bimonthly nest check and weighing) and to both research activity (monthly nest check and weighing) and evening viewing by tourists. We found that corticosterone concentrations increased significantly over 30 min of capture, with naïve penguins demonstrating a more acute stress response during the day than at night. Penguins that had previously been exposed to handling at the research and research/visitor sites showed elevated corticosterone concentrations and consistently more aggressive behaviour after 30 min compared with naïve birds, although there were no significant differences in baseline corticosterone concentrations. Our findings demonstrate that these little penguins have not habituated to routine capture, but rather mount a heightened physiological and behavioural response to handling by humans. Less invasive research monitoring techniques, such as individual identification with PIT tags and automatic recording and weighing, and a reduction in handling during the day should be considered to mitigate some of the potentially negative effects of disturbance. Given the paucity of data on the long-term consequences of heightened stress on animal physiology, our study highlights the need for further investigation of the relationship between the corticosterone

  19. In vitro production of tumor necrosis factor-alpha by human monocytes stimulated with lipopolysaccharide is positively correlated with increased blood monocytes after exposure to a swine barn.

    Science.gov (United States)

    Willson, P J; Khozani, T Talaei; Juurlink, B H J; Senthilselvan, A; Rennie, D C; Gerdts, V; Gawaziuk, J; Schneberger, D; Burch, Lauranell H; Dosman, J A

    2008-01-01

    Recently there has been interest in the air quality in and around intensive livestock production facilities, such as modern swine production barns, where agricultural workers and surrounding residents may be exposed to elevated levels of organic dusts. The health effects of these exposures are not completely understood. The study that is reported here is a component of a larger investigation of the relationships among the acute effects of high-concentration endotoxin exposure (swine barn dust), polymorphisms in the TLR4 gene, and respiratory outcomes following exposure to swine confinement buildings. The relationships among a mediator of acute lung inflammation, tumor necrosis factor alpha (TNF-alpha), and clinical responses to acute swine barn exposure were characterized. Analysis of the results showed that in vitro stimulation of human monocytes with as little as 1 ng/ml of lipopolysaccharide (LPS) produced a significant increase in the monocytes that produced TNF-alpha. Although the proportion of TNF-alpha-positive monocytes after in vitro stimulation with 1 ng/ml of LPS was not associated with gender or TLR4 genotype, it was positively associated with the concentration of monocytes in blood after barn exposure. Thus, these two responses to different forms of LPS exposure are significantly correlated, and more responsive monocytes in vitro indicate a forthcoming relative monocytosis, post barn exposure, which may initiate a cascade of chronic inflammation.

  20. Mercury Human Exposure in Populations Living Around Lake Tana (Ethiopia).

    Science.gov (United States)

    Habiba, G; Abebe, G; Bravo, Andrea G; Ermias, D; Staffan, Ǻ; Bishop, K

    2017-02-01

    A survey carried out in Lake Tana in 2015 found that Hg levels in some fish species exceeded internationally accepted safe levels for fish consumption. The current study assesses human exposure to Hg through fish consumption around the Lake Tana. Of particular interest was that a dietary intake of fishes is currently a health risk for Bihar Dar residents and anglers. Hair samples were collected from three different groups: anglers, college students and teachers, and daily laborers. A questionary includes gender, age, weight, activity. Frequency of fish consumption and origin of the eaten fish were completed by each participant. Mercury concentrations in hair were significantly higher (P value mercury and age associated with mercury concentration in scalp hair. Mercury concentrations in the hair of men were on average twice the value of the women. Also, users of skin lightening soap on a daily basis had 2.5 times greater mercury in scalp hair than non-users. Despite the different sources of mercury exposure mentioned above, the mercury concentrations of the scalp hair of participants of this study were below levels deemed to pose a threat to health.

  1. Effects of acute dieldrin exposure on neurotransmitters and global gene transcription in largemouth bass (Micropterus salmoides) hypothalamus.

    Science.gov (United States)

    Martyniuk, Christopher J; Feswick, April; Spade, Daniel J; Kroll, Kevin J; Barber, David S; Denslow, Nancy D

    2010-08-01

    Exposure to dieldrin induces neurotoxic effects in the vertebrate CNS and disrupts reproductive processes in teleost fish. Reproductive impairment observed in fish by dieldrin is likely the result of multiple effects along the hypothalamic-pituitary-gonadal axis, but the molecular signaling cascades are not well characterized. To better elucidate the mode of action of dieldrin in the hypothalamus, this study measured neurotransmitter levels and examined the transcriptomic response in female largemouth bass (LMB) to an acute treatment of dieldrin. Male and female LMB were injected with either vehicle or 10 mg dieldrin/kg and sacrificed after 7 days. There were no significant changes in dopamine or DOPAC concentrations in the neuroendocrine brain of males and females after treatment but GABA levels in females were moderately increased 20-30% in the hypothalamus and cerebellum. In the female hypothalamus, there were 227 transcripts (pdieldrin. Functional enrichment analysis revealed transcription, DNA repair, ubiquitin-proteasome pathway, and cell communication, as biological processes over-represented in the microarray analysis. Pathway analysis identified DNA damage, inflammation, regeneration, and Alzheimer's disease as major cell processes and diseases affected by dieldrin. Using multiple bioinformatics approaches, this study demonstrates that the teleostean hypothalamus is a target for dieldrin-induced neurotoxicity and provides mechanistic evidence that dieldrin activates similar cell pathways and biological processes that are also associated with the etiology of human neurological disorders. (c) 2010 Elsevier Inc. All rights reserved.

  2. Human exposure to fipronil from dogs treated with frontline.

    Science.gov (United States)

    Jennings, K A; Canerdy, T D; Keller, R J; Atieh, B H; Doss, R B; Gupta, R C

    2002-10-01

    This investigation determined fipronil residues on gloves worn while petting dogs after Frontline application. Frontline contains 9.8% fipronil, which controls fleas and ticks on dogs for at least 30 d. Frontline (1.34 ml) was applied topically on adult household dogs and gloves worn for 5 min during pettingwere collected 24 hr and 1, 2, 3, 4 and 5 w post-Frontline application for fipronil residue determinations using GC/MS. The highest concentration of fipronil (589.3 +/- 205.7ppm) was detected 24 h after Frontline application and was undetectable in the gloves collected at 5w. Repeated exposure to such contamination can pose human health risks.

  3. LIPOPOLYSACCHARIDE INDUCES EXPOSURE OF FIBRINOGEN RECEPTORS ON HUMAN PLATELETS

    Institute of Scientific and Technical Information of China (English)

    于希春; 吴其夏

    1995-01-01

    The effect of lipopolysaccharide (LPS) on the exposure of platelet fibrinogen receptors was investigated.The results showed that:1)LPS increased the binding of fibrinogen-gold complexes to platelets and the labels were primarily limited to shape-changed platelets;2)LPS caused a dose-dependent rise in intracellular Ca2+ concentration in platelets;3)LPS induced the activation of platelet protein kinase C(PKC) and the phosphorylation of glycoprotein llla (GP llla) which was inhibited by H-7.All these results suggest that stimulation of platelets with LPS causes a conformational change in glycoprotein llb/Illa (GPllb/llla) through platelet shape change and/or phosphorylation of GPllla via PKC,which serves to expose the fibrinogen binding sites of GPllb/llla on human platelets.

  4. Acute Radiation Effects Resulting from Exposure to Solar Particle Event-Like Radiation

    Science.gov (United States)

    Kennedy, Ann; Cengel, Keith

    2012-07-01

    A major solar particle event (SPE) may place astronauts at significant risk for the acute radiation syndrome (ARS), which may be exacerbated when combined with other space flight stressors, such that the mission or crew health may be compromised. The National Space Biomedical Research Institute (NSBRI) Center of Acute Radiation Research (CARR) is focused on the assessment of risks of adverse biological effects related to the ARS in animal models exposed to space flight stressors combined with the types of radiation expected during an SPE. As part of this program, FDA-approved drugs that may prevent and/or mitigate ARS symptoms are being evaluated. The CARR studies are focused on the adverse biological effects resulting from exposure to the types of radiation, at the appropriate energies, doses and dose-rates, present during an SPE (and standard reference radiations, gamma rays or electrons). The ARS is a phased syndrome which often includes vomiting and fatigue. Other acute adverse biologic effects of concern are the loss of hematopoietic cells, which can result in compromised bone marrow and immune cell functions. There is also concern for skin damage from high SPE radiation doses, including burns, and resulting immune system dysfunction. Using 3 separate animal model systems (ferrets, mice and pigs), the major ARS biologic endpoints being evaluated are: 1) vomiting/retching and fatigue, 2) hematologic changes (with focus on white blood cells) and immune system changes resulting from exposure to SPE radiation with and without reduced weightbearing conditions, and 3) skin injury and related immune system functions. In all of these areas of research, statistically significant adverse health effects have been observed in animals exposed to SPE-like radiation. Countermeasures for the management of ARS symptoms are being evaluated. New research findings from the past grant year will be discussed. Acknowledgements: This research is supported by the NSBRI Center of Acute

  5. Quantifying human exposure to air pollution - moving from static monitoring to spatio-temporally resolved personal exposure assessment

    DEFF Research Database (Denmark)

    Steinle, Susanne; Reis, Stefan; Sabel, Clive E

    2013-01-01

    results from multifaceted relationships and interactions between environmental and human systems, adding complexity to the assessment process. Traditionally, approaches to quantify human exposure have relied on pollutant concentrations from fixed air quality network sites and static population...... distributions. New developments in sensor technology now enable us to monitor personal exposure to air pollutants directly while people are moving through their activity spaces and varying concentration fields. The literature review on which this paper is based on reflects recent developments in the assessment...... for the integrated assessment of human exposure to air pollutants taking into account latest technological capabilities and contextual information. Highlights ? We review and discuss recent developments and advances of research into personal exposure to air pollution. ? We emphasise the importance of personal...

  6. Influence of acute exposure to high altitude on basal and postprandial plasma levels of gastroenteropancreatic peptides.

    Directory of Open Access Journals (Sweden)

    Rudolf L Riepl

    Full Text Available Acute mountain sickness (AMS is characterized by headache often accompanied by gastrointestinal complaints that vary from anorexia through nausea to vomiting. The aim of this study was to investigate the influence of high altitude on plasma levels of gastroenteropancreatic (GEP peptides and their association to AMS symptoms. Plasma levels of 6 GEP peptides were measured by radioimmunoassay in 11 subjects at 490 m (Munich, Germany and, after rapid passive ascent to 3454 m (Jungfraujoch, Switzerland, over the course of three days. In a second study (n = 5, the same peptides and ghrelin were measured in subjects who consumed standardized liquid meals at these two elevations. AMS symptoms and oxygen saturation were monitored. In the first study, both fasting (morning 8 a.m. and stimulated (evening 8 p.m. plasma levels of pancreatic polypeptide (PP and cholecystokinin (CCK were significantly lower at high altitude as compared to baseline, whereas gastrin and motilin concentrations were significantly increased. Fasting plasma neurotensin was significantly enhanced whereas stimulated levels were reduced. Both fasting and stimulated plasma motilin levels correlated with gastrointestinal symptom severity (r = 0.294, p = 0.05, and r = 0.41, p = 0.006, respectively. Mean O(2-saturation dropped from 96% to 88% at high altitude. In the second study, meal-stimulated integrated (= area under curve plasma CCK, PP, and neurotensin values were significantly suppressed at high altitude, whereas integrated levels of gastrin were increased and integrated VIP and ghrelin levels were unchanged. In summary, our data show that acute exposure to a hypobaric hypoxic environment causes significant changes in fasting and stimulated plasma levels of GEP peptides over consecutive days and after a standardized meal. The changes of peptide levels were not uniform. Based on the inhibition of PP and neurotensin release a reduction of the cholinergic tone can be postulated.

  7. Genotoxic Evaluation of Mikania laevigata Extract on DNA Damage Caused by Acute Coal Dust Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, T.P.; Heuser, V.D.; Tavares, P.; Leffa, D.D.; da Silva, G.A.; Citadini-Zanette, V.; Romao, P.R.T.; Pinho, R.A.; Streck, E.L.; Andrade,V.M. [University of Extremo Catarinense, Criciuma, SC (Brazil)

    2009-06-15

    We report data on the possible antigenotoxic activity of Mikania laevigata extract (MLE) after acute intratracheal instillation of coal dust using the comet assay in peripheral blood, bone marrow, and liver cells and the micronucleus test in peripheral blood of Wistar rats. The animals were pretreated for 2 weeks with saline solution (groups 1 and 2) or MLE (100 mg/kg) (groups 3 and 4). On day 15, the animals were anesthetized with ketamine (80 mg/kg) and xylazine (20 mg/kg), and gross mineral coal dust (3 mg/0.3 mL saline) (groups 2 and 4) or saline solution (0.3 mL) (groups 1 and 3) was administered directly in the lung by intratracheal administration. Fifteen days after coal dust or saline instillation, the animals were sacrificed, and the femur, liver, and peripheral blood were removed. The results showed a general increase in the DNA damage values at 8 hours for all treatment groups, probably related to surgical procedures that had stressed the animals. Also, liver cells from rats treated with coal dust, pretreated or not with MLE, showed statistically higher comet assay values compared to the control group at 14 days after exposure. These results could be expected because the liver metabolizes a variety of organic compounds to more polar by-products. On the other hand, the micronucleus assay results did not show significant differences among groups. Therefore, our data do not support the antimutagenic activity of M. laevigata as a modulator of DNA damage after acute coal dust instillation.

  8. Exploring the molecular mechanism of acute heat stress exposure in broiler chickens using gene expression profiling.

    Science.gov (United States)

    Luo, Q B; Song, X Y; Ji, C L; Zhang, X Q; Zhang, D X

    2014-08-10

    The process of heat regulation is complex and its exact molecular mechanism is not fully understood. In this study, to investigate the global gene regulation response to acute heat exposure, gene microarrays were exploited to analyze the effects of heat stress on three tissues (brain, liver, leg muscle) of the yellow broiler chicken (Gallus gallus). We detected 166 differentially expressed genes (DEGs) in the brain, 219 in the leg muscle and 317 in the liver. Six of these genes were differentially expressed in all three tissues and were validated by qRT-PCR, and included heat shock protein genes (HSPH1, HSP25), apoptosis-related genes (RB1CC1, BAG3), a cell proliferation and differentiation-related gene (ID1) and the hunger and energy metabolism related gene (PDK). All these genes might be important factors in chickens suffering from heat stress. We constructed gene co-expression networks using the DEGs of the brain, leg muscle and liver and two, four and two gene co-expression modules were identified in these tissues, respectively. Functional enrichment of these gene modules revealed that various functional clusters were related to the effects of heat stress, including those for cytoskeleton, extracellular space, ion binding and energy metabolism. We concluded that these genes and functional clusters might be important factors in chickens under acute heat stress. Further in-depth research on the newly discovered heat-related genes and functional clusters is required to fully understand their molecular functions in thermoregulation. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. A test chamber for experimental hydrogen fluoride exposure in humans.

    Science.gov (United States)

    Søstrand, P; Kongerud, J; Eduard, W; Nilsen, T; Skogland, M; Boe, J

    1997-07-01

    An inhalation chamber was built to perform experimental studies with hydrogen fluoride (HF), other gases, and particulate matter. The present study sought to describe a new gas delivery system and the distribution and concentration of HF gas in the chamber. The aluminum chamber has a volume of 19.2 m3 and a variable ventilation rate of about 1 to 10 air changes per hour. The negative pressure difference between the chamber and outside air can be regulated from 0 to 300 Pa. HF was fed at concentrations of up to 4000 mg/m3 directly into the ventilation duct feeding the chamber through openings with diameters as small as 50 microns, oriented opposite to the airflow. Gas flow was varied from about 0.1 dm3/min at a pressure of 4 atm. The dilution factor of HF concentration from cylinder to chamber was on the order of 10(3) to 10(4). The standard deviation (SD) of the HF concentrations at a fixed measurement point during a 1-hour test was typically 0.05 mg/m3 at a time-weighted average (TWA) concentration of 2.66 mg/m3. The SD of the TWA HF concentrations at six locations in the chamber was typically 0.05 mg/m3 and 0.29 mg/m3 at 0.61 and 3.46 mg/m3, respectively. Human exposure could be predicted from calculations based on ventilation data, gas flow, and observed ratio between calculated and measured concentrations. When the target exposure concentration was 1.5 mg/m3, the measured mean exposure concentration was typically 1.54 mg/m3 (range: 1.4-1.7 mg/m3, SD 0.09 mg/m3, n = 8). The chamber is well-suited for inhalation studies in humans. Chamber atmosphere was controlled and has proved to be stable and homogeneous, even in tests with HF, a highly reactive gas in the class of superacids.

  10. Acute exposure to 17α-ethinylestradiol disrupts audience effect on male-female interactions in Betta splendens.

    Science.gov (United States)

    Forette, Lindsay M; Mannion, Krystal L; Dzieweczynski, Teresa L

    2015-04-01

    Endocrine disrupting chemicals can negatively impact the morphology and behavior of organisms inhabiting polluted waters. Male-typical behaviors are often reduced after exposure, suggesting that exposure may have population-level effects. One way in which exposure may exert population-level effects is by interfering with communication within a network of individuals. Acute exposure to the estrogen mimic 17α-ethinylestradiol (EE2) disrupts the ability of male Siamese fighting fish, Betta splendens, to modify their behavior during male-male interactions when an audience is present. However, it is unknown whether audience effects during male-female interactions may be similarly altered. To examine this, male-female pairs that were given an acute exposure to EE2 or remained unexposed interacted in the presence of a female, male, or no audience. Sex differences were found between unexposed males and females. More interactant-directed gill flaring was displayed by control males when a male audience was present while control females performed this behavior more in the presence of an audience, regardless of sex. Both males and females in the control group performed more interactant-directed tail beats in the presence of a female audience. EE2 exposure made all audience effects disappear as treated males and females did not differ in their responses between audience types. These results demonstrate that acute exposure to EE2 may disrupt behavioral adjustments to audience type within a social network. This disruption may, in turn, influence population dynamics in this species as both males and females use information obtained from observing interactions in later encounters with the observed individuals.

  11. Cytotoxicity and inflammation in human alveolar epithelial cells following exposure to occupational levels of gold and silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Bachand, George D., E-mail: gdbacha@sandia.gov [Sandia National Laboratories, Center for Integrated Nanotechnologies (United States); Allen, Amy [Sandia National Laboratories, Department of Analytical Science (United States); Bachand, Marlene [Sandia National Laboratories, Department of Nanobiology (United States); Achyuthan, Komandoor E. [Sandia National Laboratories, Department of Biosensors and Nanomaterials (United States); Seagrave, Jean Clare [Lovelace Respiratory Research Institute, Applied Life Science and Toxicology Division (United States); Brozik, Susan M. [Sandia National Laboratories, Department of Biosensors and Nanomaterials (United States)

    2012-10-15

    While inhalation represents one of the most likely routes of exposure, the toxicity and response of nanoparticles at concentrations expected from such an exposure are not well understood. Here we characterized the in vitro response of human A549 adenocarcinomic alveolar epithelial cells following exposure to gold (AuNP) and silver (AgNP) nanoparticles at levels approximating an occupational exposure. Changes in neither oxidative stress nor cytotoxicity were significantly affected by exposure to AgNPs and AuNPs, regardless of NP type (Ag vs. Au), concentration, surface ligand (citrate or tannic acid), or size. An inflammatory response was, however, observed in response to 20 nm AgNPs and 20 nm AuNPs, where significant differences in the release of interleukin (IL)-8 but not IL-6 were observed. Additional data demonstrated that increased IL-8 secretion was strongly dependent on both nanoparticle size and concentration. Overall these data suggest that, while not acutely toxic, occupational exposure to AuNPs and AgNPs may trigger a significant inflammatory response in alveolar epithelium. Moreover, the differential responses in IL-8 and IL-6 secretion suggest that NPs may induce a response pathway that is distinct from those commonly elicited by allergens and pathogens.

  12. Guide to the evaluation of human exposure to noise from large wind turbines

    Science.gov (United States)

    Stephens, D. G.; Shepherd, K. P.; Hubbard, H. H.; Grosveld, F.

    1982-01-01

    Guidance for evaluating human exposure to wind turbine noise is provided and includes consideration of the source characteristics, the propagation to the receiver location, and the exposure of the receiver to the noise. The criteria for evaluation of human exposure are based on comparisons of the noise at the receiver location with the human perception thresholds for wind turbine noise and noise-induced building vibrations in the presence of background noise.

  13. Acute fluoxetine exposure alters crab anxiety-like behaviour, but not aggressiveness.

    Science.gov (United States)

    Hamilton, Trevor James; Kwan, Garfield T; Gallup, Joshua; Tresguerres, Martin

    2016-01-25

    Aggression and responsiveness to noxious stimuli are adaptable traits that are ubiquitous throughout the animal kingdom. Like vertebrate animals, some invertebrates have been shown to exhibit anxiety-like behaviour and altered levels of aggression that are modulated by the neurotransmitter serotonin. To investigate whether this influence of serotonin is conserved in crabs and whether these behaviours are sensitive to human antidepressant drugs; the striped shore crab, Pachygrapsus crassipes, was studied using anxiety (light/dark test) and aggression (mirror test) paradigms. Crabs were individually exposed to acute doses of the selective serotonin reuptake inhibitor, fluoxetine (5 or 25 mg/L), commonly known as Prozac®, followed by behavioural testing. The high dose of fluoxetine significantly decreased anxiety-like behaviour but had no impact on mobility or aggression. These results suggest that anxiety-like behaviour is more sensitive to modulation of serotonin than is aggressiveness in the shore crab.

  14. Exposure of humans to ambient levels of ozone for 6. 6 hours causes cellular and biochemical changes in the lung

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, R.B.; McDonnell, W.F.; Mann, R.; Becker, S.; House, D.E.; Schreinemachers, D.; Koren, H.S. (Environmental Protection Agency, Research Triangle Park, NC (USA))

    1991-01-01

    An acute (2 h) exposure of humans to 0.4 ppm ozone initiates biochemical changes in the lung that result in the production of components mediating inflammation and acute lung damage as well as components having the potential to lead to long-term effects such as fibrosis. However, many people are exposed to lower levels of ozone than this, but for periods of several hours. Therefore, it is important to determine if a prolonged exposure to low levels of ozone is also capable of causing cellular and biochemical changes in the lung. Nonsmoking males were randomly exposed to filtered air and either 0.10 ppm ozone or 0.08 ppm ozone for 6.6 h with moderate exercise (40 liters/min). Bronchoalveolar lavage (BAL) was performed 18 h after each exposure, and cells and fluid were analyzed. The BAL fluid of volunteers exposed to 0.10 ppm ozone had significant increases in neutrophils (PMNs), protein, prostaglandin E2 (PGE2), fibronectin, interleukin-6 (IL-6), and lactate dehydrogenase (LDH) compared with BAL fluid from the same volunteers exposed to filtered air. In addition, there was a decrease in the ability of alveolar macrophages to phagocytize yeast via the complement receptor. Exposure to 0.08 ppm ozone resulted in significant increases in PMNs, PGE2, LDH, IL-6, alpha 1-antitrypsin, and decreased phagocytosis via the complement receptor. However, BAL fluid protein and fibronectin were no longer significantly elevated. We conclude that exposure of humans to as low a level as 0.08 ppm for 6.6 h is sufficient to initiate an inflammatory reaction in the lung.

  15. Tissue-specific effects of acute aluminium exposure on the radiation-induced bystander effect in rainbow trout (Oncorhynchus mykiss, Walbaum).

    Science.gov (United States)

    Smith, Richard W; Seymour, Colin B; Moccia, Richard D; Mothersill, Carmel E

    2015-01-01

    To investigate if aluminium (Al) modifies the rainbow trout response to radiation exposure and/or the induction of a radiation-induced bystander effect. Rainbow trout were exposed to 100 or 200 μg l(-1) Al (for 3 h), a 0.5 Gy X-ray dose or Al followed immediately by irradiation. The exposed fish were then swum with completely untreated bystander fish. A human reporter cell clonogenic assay was used to determine whether Al exposure modified the effects of irradiation on the skin and gills from directly exposed fish and also the radiation-induced bystander effect in untreated fish. Al exposure did not modify the response to direct irradiation by the skin, or the gill. Al did not modify the bystander effect in the skin. However Al did modify the bystander effect in the gill. Gills of bystander fish swum with fish exposed to 200 μg l(-1) Al, followed by irradiation, caused a greater reduction in HPV-G cell survival than was caused by irradiation only. Interestingly Al exposure only also caused a bystander effect (reduced HPV-G survival) in the gill. This study shows that, in a multiple stressor scenario, the communication of radiation-induced stress signals is modified on a tissue-specific basis by acute Al exposure. Aside from the implications this has for radiological protection this response may also have potential for environmental monitoring where detection of the bystander effect could act as an indicator of radiation exposure when direct exposure responses are not evident.

  16. Human exposure to piroplasms in Central and Northern Italy

    Directory of Open Access Journals (Sweden)

    Simona Gabrielli

    2014-03-01

    Full Text Available A serosurvey has been conducted in Northern and Central Italy to investigate the presence in humans of antibodies against zoonotic Babesia and Theileria species. The study focused on a total of 432 volunteers, of which 290 were persistently exposed to tick bites because of their jobs (forester employees, livestock keepers, veterinary practitioners, farmers and hunters and 142 resident in the same area less frequently exposed. An indirect fluorescent antibody test (IFAT for humans was used to detect antibodies to Babesia microti, IFAT tests for veterinary use were modified to detect reactivity to Babesia bovis, Babesia canis and Theileria equi. A laboratory-derived ELISA was employed to detect antibodies to Babesia divergens. Both reactive and 10 negative sera were analysed against plasmodial antigens to evaluate possible aspecificity. A high reactivity to piroplasm antigens was found, showing significant difference between the sera of the two groups of volunteers (24% vs 7.0%; p<0.001. No cross-reactivity was observed, while each professional group showed reactivity that would fit with the professional risk exposure. In particular, a high reactivity to B. microti and B. divergens antigens was observed in foresters and hunters (32% and 12%, respectively. This is the first report on the human seroreactivity to piroplasms in Italy; it also provides additional epidemiological information on these tick-borne zoonoses in Europe. Our findings suggest the possible occurrence of piroplasm infections in Italy and alert physicians to consider these otherwise neglected parasitic diseases when dealing with any febrile illness, especially in subjects exposed to tick bites.

  17. Oral exposure to Phytomonas serpens attenuates thrombocytopenia and leukopenia during acute infection with Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Rosiane V da Silva

    Full Text Available Mice infected with Trypanosoma cruzi, the agent of Chagas disease, rapidly develop anemia and thrombocytopenia. These effects are partially promoted by the parasite trans-sialidase (TS, which is shed in the blood and depletes sialic acid from the platelets, inducing accelerated platelet clearance and causing thrombocytopenia during the acute phase of disease. Here, we demonstrate that oral immunization of C57BL/6 mice with Phytomonas serpens, a phytoflagellate parasite that shares common antigens with T. cruzi but has no TS activity, reduces parasite burden and prevents thrombocytopenia and leukopenia. Immunization also reduces platelet loss after intraperitoneal injection of TS. In addition, passive transfer of immune sera raised in mice against P. serpens prevented platelet clearance. Thus, oral exposure to P. serpens attenuates the progression of thrombocytopenia induced by TS from T. cruzi. These findings are not only important for the understanding of the pathogenesis of T. cruzi infection but also for developing novel approaches of intervention in Chagas disease.

  18. Effect of acute exposure to moderate altitude on muscle power: hypobaric hypoxia vs. normobaric hypoxia.

    Science.gov (United States)

    Feriche, Belén; García-Ramos, Amador; Calderón-Soto, Carmen; Drobnic, Franchek; Bonitch-Góngora, Juan G; Galilea, Pedro A; Riera, Joan; Padial, Paulino

    2014-01-01

    When ascending to a higher altitude, changes in air density and oxygen levels affect the way in which explosive actions are executed. This study was designed to compare the effects of acute exposure to real or simulated moderate hypoxia on the dynamics of the force-velocity relationship observed in bench press exercise. Twenty-eight combat sports athletes were assigned to two groups and assessed on two separate occasions: G1 (n = 17) in conditions of normoxia (N1) and hypobaric hypoxia (HH) and G2 (n = 11) in conditions of normoxia (N2) and normobaric hypoxia (NH). Individual and complete force-velocity relationships in bench press were determined on each assessment day. For each exercise repetition, we obtained the mean and peak velocity and power shown by the athletes. Maximum power (Pmax) was recorded as the highest P(mean) obtained across the complete force-velocity curve. Our findings indicate a significantly higher absolute load linked to P(max) (∼ 3%) and maximal strength (1 RM) (∼ 6%) in G1 attributable to the climb to altitude (Ppress.

  19. Delayed Effects of Acute Radiation Exposure in a Murine Model of the H-ARS: Multiple-Organ Injury Consequent to Total Body Irradiation.

    Science.gov (United States)

    Unthank, Joseph L; Miller, Steven J; Quickery, Ariel K; Ferguson, Ethan L; Wang, Meijing; Sampson, Carol H; Chua, Hui Lin; DiStasi, Matthew R; Feng, Hailin; Fisher, Alexa; Katz, Barry P; Plett, P Artur; Sandusky, George E; Sellamuthu, Rajendran; Vemula, Sasidhar; Cohen, Eric P; MacVittie, Thomas J; Orschell, Christie M

    2015-11-01

    The threat of radiation exposure from warfare or radiation accidents raises the need for appropriate animal models to study the acute and chronic effects of high dose rate radiation exposure. The goal of this study was to assess the late development of fibrosis in multiple organs (kidney, heart, and lung) in survivors of the C57BL/6 mouse model of the hematopoietic-acute radiation syndrome (H-ARS). Separate groups of mice for histological and functional studies were exposed to a single uniform total body dose between 8.53 and 8.72 Gy of gamma radiation from a Cs radiation source and studied 1-21 mo later. Blood urea nitrogen levels were elevated significantly in the irradiated mice at 9 and 21 mo (from ∼22 to 34 ± 3.8 and 69 ± 6.0 mg dL, p irradiated controls) and correlated with glomerosclerosis (29 ± 1.8% vs. 64 ± 9.7% of total glomeruli, p irradiated controls). Glomerular tubularization and hypertrophy and tubular atrophy were also observed at 21 mo post-total body irradiation (TBI). An increase in interstitial, perivascular, pericardial and peribronchial fibrosis/collagen deposition was observed from ∼9-21 mo post-TBI in kidney, heart, and lung of irradiated mice relative to age-matched controls. Echocardiography suggested decreased ventricular volumes with a compensatory increase in the left ventricular ejection fraction. The results indicate that significant delayed effects of acute radiation exposure occur in kidney, heart, and lung in survivors of the murine H-ARS TBI model, which mirrors pathology detected in larger species and humans at higher radiation doses focused on specific organs.

  20. A flexible matrix-based human exposure assessment framework suitable for LCA and CAA

    DEFF Research Database (Denmark)

    Jolliet, Olivier; Ernstoff, Alexi; Huang, Lei

    2016-01-01

    of near-and far-field pathways and helps to understand the contribution of individual pathways to overall human exposure in various product application contexts. When combined with toxicity information this approach is a resourceful way to inform LCA and CAA and minimize human exposure to toxic chemicals......Humans can be exposed to chemicals via near-field exposure pathways (e.g. through consumer product use) and far-field exposure pathways (e.g. through environmental emissions along product life cycles). Pathways are often complex where chemicals can transfer directly from products to humans during...... use or exchange between near-and far-field compartments until sub -fractions reach humans via inhalation, ingestion or dermal uptake. Currently, however, multimedia exposure models mainly focus on far-field exposure pathways. Metrics and modeling approaches used in far-field, emission-based models...

  1. ASSESSING HUMAN EXPOSURE TO GRASS POLLEN IN DENMARK

    DEFF Research Database (Denmark)

    Peel, Robert George; Hertel, Ole; Herbert, Rob

    Objectives: Exposure to pollen is typically assessed using data collected at fixed roof-top monitoring stations, which give a general picture of airborne pollen concentrations over a wide region. Actual exposure levels can be obtained through personal exposure monitoring. This is typically done u...

  2. Effects of an acute and a sub-chronic 900 MHz GSM exposure on brain activity and behaviors of rats

    Energy Technology Data Exchange (ETDEWEB)

    Elsa Brillaud; Aleksandra Piotrowski; Anthony Lecomte; Franck Robidel; Rene de Seze [Toxicology Unit, INERIS, Verneuil en Halatte (France)

    2006-07-01

    Radio frequencies are suspected to produce health effects. Concerning the mobile phone technology, according to position during use (close to the head), possible effects of radio frequencies on the central nervous system have to be evaluated. Previous works showed contradictory results, possibly due to experimental design diversity. In the framework of R.A.M.P. 2001 project, we evaluated possible effect of a 900 MHz GSM exposure on the central nervous system of rat at a structural, a functional and a behavioral level after acute or sub-chronic exposures. Rats were exposed using a loop antenna system to different S.A.R. levels and durations, according to results of the French C.O.M.O.B.I.O. 2001 project. A functional effect was found (modification of the cerebral activity and increase of the glia surface) after an acute exposure, even at a low level of brain averaged S.A.R. (1.5 W/kg). No cumulative effect was observed after a sub-chronic exposure (same amplitude of the effect). No structural or behavioral consequence was noted. We do not conclude on the neurotoxicity of the 900 MHz GSM exposure on the rat brain. Our results do not indicate any health risk. (authors)

  3. Assessment of locomotion behavioral defects induced by acute toxicity from heavy metal exposure in nematode Caenorhabditis elegans

    Institute of Scientific and Technical Information of China (English)

    WANG Dayong; XING Xiaojuan

    2008-01-01

    Locomotion behaviors are susceptible to disruption by a broad spectrum of chemicals and environmental stresses. However, no systematic testing of locomotion behavior defects induced by metal exposure has been conducted in the model organism of nematode Caenorhabditis elegans. In this study, the acute toxicity from heavy metal exposure on the locomotion behaviors was analyzed in nematodes. Endpoints of head thrash, body bend, forward turn, backward turn, and Omega/U turn were chosen to evaluate the locomotion behavioral defects. Our data suggest that the endpoints of head thrash, body bend, and forward turn will be useful for the evaluation of heavy metal toxicity in nematodes. The endpoint of head thrash could detect the toxicity from Cd, Co, Cr, Cu, Hg, and Pb exposures at a low concentration (2.5 μmol/L). The endpoint of body bend could be explored to evaluate the toxicity from all assayed heavy metal exposures at different concentrations, whereas the endpoint of forward turn will be more useful for the evaluation of heavy metal toxicity at high concentrations. Thus, endpoints of these locomotion behaviors establish a fast and economic way to assess the presence of acute toxicity from heavy metal exposure in nematode C. elegans.

  4. A changing climate: impacts on human exposures to O3 using an integrated modeling methodology

    Science.gov (United States)

    Predicting the impacts of changing climate on human exposure to air pollution requires future scenarios that account for changes in ambient pollutant concentrations, population sizes and distributions, and housing stocks. An integrated methodology to model changes in human exposu...

  5. Acute but not chronic ethanol exposure impairs retinol oxidation in the small and large intestine of the rat

    DEFF Research Database (Denmark)

    Parlesak, Alexandr; Ellendt, K.; Lindros, K.

    2005-01-01

    BACKGROUND AND AIM: Ethanol has been shown to inhibit retinol oxidation at the level of alcohol dehydrogenase in liver and colon but not previously in the small intestine. In the present study we investigated how chronic alcohol feeding and acute ethanol exposure affects retinol dehydrogenase...... activity in the colon and small intestine of the rat. METHODS: Rats were fed ethanol in a liquid diet for six weeks. Control rats received a similar diet but with ethanol isocalorically replaced by carbohydrates. Retinol dehydrogenase was analyzed from cell cytosol samples from the small and the large...... higher, respectively). While chronic alcohol feeding did not affect these parameters, acute ethanol exposure reduced V(max) and V(max)/K(m) dose-dependently (p

  6. Human urinary biomarkers of dioxin exposure: analysis by metabolomics and biologically driven data dimensionality reduction.

    Science.gov (United States)

    Jeanneret, Fabienne; Boccard, Julien; Badoud, Flavia; Sorg, Olivier; Tonoli, David; Pelclova, Daniela; Vlckova, Stepanka; Rutledge, Douglas N; Samer, Caroline F; Hochstrasser, Denis; Saurat, Jean-Hilaire; Rudaz, Serge

    2014-10-15

    Untargeted metabolomic approaches offer new opportunities for a deeper understanding of the molecular events related to toxic exposure. This study proposes a metabolomic investigation of biochemical alterations occurring in urine as a result of dioxin toxicity. Urine samples were collected from Czech chemical workers submitted to severe dioxin occupational exposure in a herbicide production plant in the late 1960s. Experiments were carried out with ultra-high pressure liquid chromatography (UHPLC) coupled to high-resolution quadrupole time-of-flight (QTOF) mass spectrometry. A chemistry-driven feature selection was applied to focus on steroid-related metabolites. Supervised multivariate data analysis allowed biomarkers, mainly related to bile acids, to be highlighted. These results supported the hypothesis of liver damage and oxidative stress for long-term dioxin toxicity. As a second step of data analysis, the information gained from the urine analysis of Victor Yushchenko after his poisoning was examined. A subset of relevant urinary markers of acute dioxin toxicity from this extreme phenotype, including glucuro- and sulfo-conjugated endogenous steroid metabolites and bile acids, was assessed for its ability to detect long-term effects of exposure. The metabolomic strategy presented in this work allowed the determination of metabolic patterns related to dioxin effects in human and the discovery of highly predictive subsets of biologically meaningful and clinically relevant compounds. These results are expected to provide valuable information for a deeper understanding of the molecular events related to dioxin toxicity. Furthermore, it presents an original methodology of data dimensionality reduction by using extreme phenotype as a guide to select relevant features prior to data modeling (biologically driven data reduction).

  7. Effects of Acute Exposure to Mild or Moderate Hypoxia on Human Psychomotor Performance and Visual-reaction Time%急性轻、中度缺氧暴露对心理运动及反应时的影响

    Institute of Scientific and Technical Information of China (English)

    李学义; 吴兴裕; 付川; 沈小凤; 杨长斌; 吴燕红

    2000-01-01

    Objective The aim of this study was to determine whether psychomotor performance and visual reaction time were affected by acute exposure to mild or moderate hypoxia. Method Eighteen healthy male volunteers performed finger tapping, simple reaction time(SRT) and 4-choice reaction time(CRT) tests at simulated altitude of 300 m (control),2800 m, 3600 m and 4400 m for 1 h in a hypobaric chamber. Result SaO2 decreased from 98%(control) to 90%,82% and 74% respectively at the various altitudes. All the performance parameters showed no significant change after exposure to 2800 m for 1 h relative to ground level(P>0.05). However the mean reaction time of 4-CRT under 3600 m prolonged and performance decreased as compared with baseline value(P0.05). Conclusion The results from this study demonstrated that there were no measurable impairment of visual reaction time and psychomotor performance under exposure to an altitude of 2800 m for 1 h. However, adverse effects on psychomotor performance were observed under 3600 m and over.%目的研究急性轻、中度缺氧暴露对人的心理运动及视觉反应时的影响. 方法利用低压舱模拟300 m (对照高度)、2800 m、3600 m、4400 m高度缺氧暴露1 h,考察了18 名健康男性青年被试者指叩测验、简单反应时和选择反应时的变化. 结果血氧饱和度(SaO2)由地面对照值98%分别降至90%、82%和74%.2800 m 缺氧暴露1 h心理运动绩效的各个参数并无显著改变(P>0.05).3600 m缺氧暴露时选择反应时的平均反应时明显延长,运动绩效下降(P0.05). 结论本研究的结果提示,急性缺氧暴露于2800 m高度1 h并未对心理运动产生严重影响,而暴露于3600 m以上高度时会对选择反应时等复杂反应产生负面影响,且随着高度的增加而加重.

  8. Effects of acute and chronic waterborne lead exposure on the swimming performance and aerobic scope of fathead minnows (Pimephales promelas).

    Science.gov (United States)

    Mager, Edward M; Grosell, Martin

    2011-06-01

    Fathead minnows were subjected to an incremental velocity test using swim tunnel respirometry for the analysis of aerobic scope and swimming performance, as critical aerobic swim speed (U(crit)), following chronic exposures (33-57 ) to 0.9±0.4, 157±18 or 689±66 nmol L⁻¹ Pb and an acute exposure (24 h) to 672±35 nmol L⁻¹ Pb (mean±SEM). Assessment of Pb-induced anemia and neurological impairment were evaluated by blood hemoglobin (Hb) concentrations and a cost of transport (COT) analysis, respectively. Fish from the acute 672±35 nmol L⁻¹ Pb (24.4±1.2 BL s⁻¹) and chronic 689±66 nmol L⁻¹ Pb (24.6±0.9 BL s⁻¹) treatments exhibited reduced U(crits) compared to control fish (27.6±0.8 BL s⁻¹). Aerobic scope was reduced by acute Pb exposure (8.6±2.6 μmol O₂ g⁻¹ h⁻¹ vs. 22.6±3.8 μmol O₂ g⁻¹ h⁻¹ from controls) owing to a decrease in maximum oxygen consumption rate (38.8±0.8 μmol O₂ g⁻¹ h⁻¹ vs. 54.0±4.2 μmol O₂ g⁻¹ h⁻¹ from controls). However, no effect on aerobic scope was observed with fish chronically exposed to Pb. Significant differences were not observed for Hb concentrations or COT. These findings suggest that the impaired swimming performances arising from acute and chronic Pb exposures reflect different mechanisms of toxicity.

  9. Effects of acute versus repeated cocaine exposure on the expression of endocannabinoid signaling-related proteins in the mouse cerebellum

    OpenAIRE

    Ana ePalomino; Francisco Javier ePavon; Eduardo eBlanco Calvo; Antonia eSerrano; Sergio eArrabal; Patricia eRivera; Antonio eVargas; Ainhoa eBilbao; Leticia eRubio; Fernando eRodriguez de Fonseca; Juan eSuarez

    2014-01-01

    Growing awareness of cerebellar involvement in addiction is based on the cerebellum’s intermediary position between motor and reward, potentially acting as an interface between motivational and cognitive functions. Here, we examined the impact of acute and repeated cocaine exposure on the two main signaling systems in the mouse cerebellum: the endocannabinoid (eCB) and glutamate systems. To this end, we investigated whether eCB signaling-related gene and protein expression {cannabinoid recept...

  10. Father's occupational exposure to carcinogenic agents and childhood acute leukemia: a new method to assess exposure (a case-control study

    Directory of Open Access Journals (Sweden)

    Rodriguez-Rivera Maria

    2008-01-01

    Full Text Available Abstract Background Medical research has not been able to establish whether a father's occupational exposures are associated with the development of acute leukemia (AL in their offspring. The studies conducted have weaknesses that have generated a misclassification of such exposure. Occupations and exposures to substances associated with childhood cancer are not very frequently encountered in the general population; thus, the reported risks are both inconsistent and inaccurate. In this study, to assess exposure we used a new method, an exposure index, which took into consideration the industrial branch, specific position, use of protective equipment, substances at work, degree of contact with such substances, and time of exposure. This index allowed us to obtain a grade, which permitted the identification of individuals according to their level of exposure to known or potentially carcinogenic agents that are not necessarily specifically identified as risk factors for leukemia. The aim of this study was to determine the association between a father's occupational exposure to carcinogenic agents and the presence of AL in their offspring. Methods From 1999 to 2000, a case-control study was performed with 193 children who reside in Mexico City and had been diagnosed with AL. The initial sample-size calculation was 150 children per group, assessed with an expected odds ratio (OR of three and a minimum exposure frequency of 15.8%. These children were matched by age, sex, and institution with 193 pediatric surgical patients at secondary-care hospitals. A questionnaire was used to determine each child's background and the characteristics of the father's occupation(s. In order to determine the level of exposure to carcinogenic agents, a previously validated exposure index (occupational exposure index, OEI was used. The consistency and validity of the index were assessed by a questionnaire comparison, the sensory recognition of the work area, and an

  11. Toxicology of microcystins with reference to cases of human intoxications and epidemiological investigations of exposures to cyanobacteria and cyanotoxins.

    Science.gov (United States)

    Svirčev, Zorica; Drobac, Damjana; Tokodi, Nada; Mijović, Biljana; Codd, Geoffrey A; Meriluoto, Jussi

    2017-02-01

    Blooms of cyanobacteria have been documented throughout history, all over the world. Mass populations of these organisms typically present hazards to human health and are known for the production of a wide range of highly toxic metabolites-cyanotoxins, of which among the most common and most investigated are the microcystins. The toxicity of the family of microcystin congeners to animal and cell models has received much attention; however, less is known about their negative effects on human health, whether via acute or chronic exposure. Useful information may be acquired through epidemiological studies since they can contribute to knowledge of the relationships between cyanotoxins and human health in environmental settings. The aim of this review is to compile and evaluate the available published reports and epidemiological investigations of human health incidents associated with exposure to mass populations of cyanobacteria from throughout the world and to identify the occurrence and likely role of microcystins in these events. After an initial screening of 134 publications, 42 publications (25 on the chronic and 17 on the acute effects of cyanotoxins) describing 33 cases of poisonings by cyanobacterial toxins in 11 countries were reviewed. The countries were Australia, China, Sri Lanka, Namibia, Serbia, Sweden, UK, Portugal, Brazil, USA, and Canada. At least 36 publications link cyanobacteria/cyanotoxins including microcystins to adverse human health effects. The studies were published between 1960 and 2016. Although the scattered epidemiological evidence does not provide a definitive conclusion, it can serve as additional information for the medical assessment of the role of microcystins in cancer development and other human health problems. This paper discusses the major cases of cyanotoxin poisonings as well as the strengths, weaknesses, and importance of the performed epidemiological research. This study also proposes some recommendations for future

  12. Long term impact of the endocrine disruptor tributyltin on male fertility following a single acute exposure.

    Science.gov (United States)

    Mitra, Sumonto; Srivastava, Ankit; Khandelwal, Shashi

    2017-10-01

    Declining rate of human fertility is a growing concern, where lifestyle and environmental factors play an important role. We recently demonstrated that tributyltin (TBT), an omnipresent endocrine disruptor, affects testicular cells in vitro. In this study, male Wistar rats were gavaged a single dose of 10, 20, and 30 mg/kg TBT-chloride (TBTC) (to mimic accidental exposure in vivo) and sacrificed on day 3 and day 7, respectively. TBT bioavailability was evaluated by estimating total tin content, and essential metal levels were analyzed along with redox molecules (ROS and GSH/GSSG) to understand the effect on physiological conditions. Blood-testicular barrier (BTB) disruption, levels of associated proteins and activity of proteolytic enzymes were evaluated to understand the effect on BTB. Histological analysis of tissue architecture and effect on protein expression of steroidogenic, stress and apoptotic markers were also evaluated. Widespread TBTC pollution can be an eventual threat to male fertility worldwide. © 2017 Wiley Periodicals, Inc.

  13. Association between exposure to environmental tobacco smoke and biomarkers of oxidative stress among patients hospitalised with acute myocardial infarction.

    Directory of Open Access Journals (Sweden)

    Ian L Megson

    Full Text Available OBJECTIVE: To determine whether exposure to environmental tobacco smoke was associated with oxidative stress among patients hospitalised for acute myocardial infarction. DESIGN: An existing cohort study of 1,261 patients hospitalised for acute myocardial infarction. SETTING: Nine acute hospitals in Scotland. PARTICIPANTS: Sixty never smokers who had been exposed to environmental tobacco smoke (admission serum cotinine ≥3.0 ng/mL were compared with 60 never smokers who had not (admission serum cotinine ≤0.1 ng/mL. INTERVENTION: None. MAIN OUTCOME MEASURES: Three biomarkers of oxidative stress (protein carbonyl, malondialdehyde (MDA and oxidised low-density lipoprotein (ox-LDL were measured on admission blood samples and adjusted for potential confounders. RESULTS: After adjusting for baseline differences in age, sex and socioeconomic status, exposure to environmental tobacco smoke was associated with serum concentrations of both protein carbonyl (beta coefficient 7.96, 95% CI 0.76, 15.17, p = 0.031 and MDA (beta coefficient 10.57, 95% CI 4.32, 16.81, p = 0.001 but not ox-LDL (beta coefficient 2.14, 95% CI -8.94, 13.21, p = 0.703. CONCLUSIONS: Exposure to environmental tobacco smoke was associated with increased oxidative stress. Further studies are requires to explore the role of oxidative stress in the association between environmental tobacco smoke and myocardial infarction.

  14. Exposure medium: key in identifying free Ag+ as the exclusive species of silver nanoparticles with acute toxicity to Daphnia magna.

    Science.gov (United States)

    Shen, Mo-Hai; Zhou, Xiao-Xia; Yang, Xiao-Ya; Chao, Jing-Bo; Liu, Rui; Liu, Jing-Fu

    2015-04-10

    It is still not very clear what roles the various Ag species play in the toxicity of silver nanoparticles (AgNPs). In this study, we found that traditional exposure media result in uncontrollable but consistent physicochemical transformation of AgNPs, causing artifacts in determination of median lethal concentration (LC50) and hindering the identification of Ag species responsible for the acute toxicity of AgNPs to Daphnia magna. This obstacle was overcome by using 8 h exposure in 0.1 mmol L(-1) NaNO3 medium, in which we measured the 8-h LC50 of seven AgNPs with different sizes and coatings, and determined the concentrations of various Ag species. The LC50 as free Ag(+) of the seven AgNPs (0.37-0.44 μg L(-1)) agreed very well with that of AgNO3 (0.40 μg L(-1)), and showed the lowest value compared to that as total Ag, total Ag(+), and dissolved Ag, demonstrating free Ag(+) is exclusively responsible for the acute toxicity of AgNPs to D. magna, while other Ag species in AgNPs have no contribution to the acute toxicity. Our results demonstrated the great importance of developing appropriate exposure media for evaluating risk of nanomaterials.

  15. Exposure Medium: Key in Identifying Free Ag+ as the Exclusive Species of Silver Nanoparticles with Acute Toxicity to Daphnia magna

    Science.gov (United States)

    Shen, Mo-Hai; Zhou, Xiao-Xia; Yang, Xiao-Ya; Chao, Jing-Bo; Liu, Rui; Liu, Jing-Fu

    2015-04-01

    It is still not very clear what roles the various Ag species play in the toxicity of silver nanoparticles (AgNPs). In this study, we found that traditional exposure media result in uncontrollable but consistent physicochemical transformation of AgNPs, causing artifacts in determination of median lethal concentration (LC50) and hindering the identification of Ag species responsible for the acute toxicity of AgNPs to Daphnia magna. This obstacle was overcome by using 8 h exposure in 0.1 mmol L-1 NaNO3 medium, in which we measured the 8-h LC50 of seven AgNPs with different sizes and coatings, and determined the concentrations of various Ag species. The LC50 as free Ag+ of the seven AgNPs (0.37-0.44 μg L-1) agreed very well with that of AgNO3 (0.40 μg L-1), and showed the lowest value compared to that as total Ag, total Ag+, and dissolved Ag, demonstrating free Ag+ is exclusively responsible for the acute toxicity of AgNPs to D. magna, while other Ag species in AgNPs have no contribution to the acute toxicity. Our results demonstrated the great importance of developing appropriate exposure media for evaluating risk of nanomaterials.

  16. Time course of systemic oxidative stress and inflammatory response induced by an acute exposure to Residual Oil Fly Ash

    Energy Technology Data Exchange (ETDEWEB)

    Marchini, T.; Magnani, N.D. [Cátedra de Química General e Inorgánica, Instituto de Bioquímica y Medicina Molecular (IBIMOL UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, C1113AAB Buenos Aires (Argentina); Paz, M.L. [Cátedra de Inmunología, Instituto de Estudios de la Inmunidad Humoral (IDEHU UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, C1113AAB Buenos Aires (Argentina); Vanasco, V. [Cátedra de Química General e Inorgánica, Instituto de Bioquímica y Medicina Molecular (IBIMOL UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, C1113AAB Buenos Aires (Argentina); Tasat, D. [CESyMA, Facultad de Ciencia Tecnología, Universidad Nacional de General San Martín, Martín de Irigoyen 3100, 1650 San Martín, Buenos Aires (Argentina); González Maglio, D.H. [Cátedra de Inmunología, Instituto de Estudios de la Inmunidad Humoral (IDEHU UBA-CONICET), Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 954, C1113AAB Buenos Aires (Argentina); and others

    2014-01-15

    It is suggested that systemic oxidative stress and inflammation play a central role in the onset and progression of cardiovascular diseases associated with the exposure to particulate matter (PM). The aim of this work was to evaluate the time changes of systemic markers of oxidative stress and inflammation, after an acute exposure to Residual Oil Fly Ash (ROFA). Female Swiss mice were intranasally instilled with a ROFA suspension (1.0 mg/kg body weight) or saline solution, and plasma levels of oxidative damage markers [thiobarbituric acid reactive substances (TBARSs) and protein carbonyls], antioxidant status [reduced (GSH) and oxidized (GSSG) glutathione, ascorbic acid levels, and superoxide dismutase (SOD) activity], cytokines levels, and intravascular leukocyte activation were evaluated after 1, 3 or 5 h of exposure. Oxidative damage to lipids and decreased GSH/GSSG ratio were observed in ROFA-exposed mice as early as 1 h. Afterwards, increased protein oxidation, decreased ascorbic acid content and SOD activity were found in this group at 3 h. The onset of an adaptive response was observed at 5 h after the ROFA exposure, as indicated by decreased TBARS plasma content and increased SOD activity. The observed increase in oxidative damage to plasma macromolecules, together with systemic antioxidants depletion, may be a consequence of a systemic inflammatory response triggered by the ROFA exposure, since increased TNF-α and IL-6 plasma levels and polymorphonuclear leukocytes activation was found at every evaluated time point. These findings contribute to the understanding of the increase in cardiovascular morbidity and mortality, in association with environmental PM inhalation. - Highlights: • An acute exposure to ROFA triggers the occurrence of systemic oxidative stress. • Changes in plasmatic oxidative stress markers appear as early as 1 h after exposure. • ROFA induces proinflammatory cytokines release and intravascular leukocyte activation. • PMN

  17. TRPA1 insensitivity of human sural nerve axons after exposure to lidocaine.

    Science.gov (United States)

    Docherty, Reginald J; Ginsberg, Lionel; Jadoon, Saqiba; Orrell, Richard W; Bhattacharjee, Anupam

    2013-09-01

    TRPA1 is an ion channel of the TRP family that is expressed in some sensory neurons. TRPA1 activity provokes sensory symptoms of peripheral neuropathy, such as pain and paraesthesia. We have used a grease gap method to record axonal membrane potential and evoked compound action potentials (ECAPs) in vitro from human sural nerves and studied the effects of mustard oil (MO), a selective activator of TRPA1. Surprisingly, we failed to demonstrate any depolarizing response to MO (50, 250 μM) in any human sural nerves. There was no effect of MO on the A wave of the ECAP, but the C wave was reduced at 250 μM. In rat saphenous nerve fibres MO (50, 250 μM) depolarized axons and reduced the C wave of the ECAP but had no effect on the A wave. By contrast, both human and rat nerves were depolarized by capsaicin (0.5 to 5 μM) or nicotine (50 to 200 μM). Capsaicin caused a profound reduction in C fibre conduction in both species but had no effect on the amplitude of the A component. Lidocaine (30 mM) depolarized rat saphenous nerves acutely, and when rat nerves were pretreated with 30 mM lidocaine to mimic the exposure of human nerves to local anaesthetic during surgery, the effects of MO were abolished whilst the effects of capsaicin were unchanged. This study demonstrates that the local anaesthetic lidocaine desensitizes TRPA1 ion channels and indicates that it may have additional mechanisms for treating neuropathic pain that endure beyond simple sodium channel blockade.

  18. High Resolution ECG for Evaluation of QT Interval Variability during Exposure to Acute Hypoxia

    Science.gov (United States)

    Zupet, P.; Finderle, Z.; Schlegel, Todd T.; Starc, V.

    2010-01-01

    Ventricular repolarization instability as quantified by the index of QT interval variability (QTVI) is one of the best predictors for risk of malignant ventricular arrhythmias and sudden cardiac death. Because it is difficult to appropriately monitor early signs of organ dysfunction at high altitude, we investigated whether high resolution advanced ECG (HR-ECG) analysis might be helpful as a non-invasive and easy-to-use tool for evaluating the risk of cardiac arrhythmias during exposure to acute hypoxia. 19 non-acclimatized healthy trained alpinists (age 37, 8 plus or minus 4,7 years) participated in the study. Five-minute high-resolution 12-lead electrocardiograms (ECGs) were recorded (Cardiosoft) in each subject at rest in the supine position breathing room air and then after breathing 12.5% oxygen for 30 min. For beat-to-beat RR and QT variability, the program of Starc was utilized to derive standard time domain measures such as root mean square of the successive interval difference (rMSSD) of RRV and QTV, the corrected QT interval (QTc) and the QTVI in lead II. Changes were evaluated with paired-samples t-test with p-values less than 0.05 considered statistically significant. As expected, the RR interval and its variability both decreased with increasing altitude, with p = 0.000 and p = 0.005, respectively. Significant increases were found in both the rMSSDQT and the QTVI in lead II, with p = 0.002 and p = 0.003, respectively. There was no change in QTc interval length (p = non significant). QT variability parameters may be useful for evaluating changes in ventricular repolarization caused by hypoxia. These changes might be driven by increases in sympathetic nervous system activity at ventricular level.

  19. ASSESSING HUMAN EXPOSURE TO GRASS POLLEN IN DENMARK

    DEFF Research Database (Denmark)

    Peel, Robert George; Hertel, Ole; Herbert, Rob

    Objectives: Exposure to pollen is typically assessed using data collected at fixed roof-top monitoring stations, which give a general picture of airborne pollen concentrations over a wide region. Actual exposure levels can be obtained through personal exposure monitoring. This is typically done...... using a suction sampler worn on the chest or lapel that measures breathing zone concentration; a more useful exposure parameter for pollen allergy sufferers is the amount of pollen inhaled, i.e. the dose. The objective of this study was to investigate how well monitoring station data reflect actual...... exposure, something that is currently not well understood. Methods: Exposure samples were collected during the 2011 grass pollen season in an area of abundant unmaintained grass coverage close to the centre of Aarhus, Denmark. Sampling was performed at two-hourly intervals between 12:00 and 20:00 on 14...

  20. Human Herpesvirus 6 Infection Presenting as an Acute Febrile Illness Associated with Thrombocytopenia and Leukopenia

    Directory of Open Access Journals (Sweden)

    Maja Arnež

    2016-01-01

    Full Text Available We present an infant with acute fever, thrombocytopenia, and leukopenia, coming from an endemic region for tick-borne encephalitis, human granulocytic anaplasmosis, and hantavirus infection. The primary human herpesvirus 6 infection was diagnosed by seroconversion of specific IgM and IgG and by identification of viral DNA in the acute patient’s serum. The patient did not show skin rash suggestive of exanthema subitum during the course of illness.

  1. Changes in Glutamate/NMDA Receptor Subunit 1 Expression in Rat Brain after Acute and Subacute Exposure to Methamphetamine

    Directory of Open Access Journals (Sweden)

    Walailuk Kerdsan

    2009-01-01

    Full Text Available Methamphetamine (METH is a psychostimulant drug of abuse that produces long-term behavioral changes including behavioral sensitization, tolerance, and dependence. METH has been reported to induce neurotoxic effects in several areas of the brain via the dopaminergic system. Changes of dopamine function can induce malfunction of the glutamatergic system. Therefore, the aim of the present study was to examine the effects of METH administration on the expression of glutamate N-methyl-D-aspartate receptor subunit 1 (NMDAR1 in frontal cortex, striatum, and hippocampal formation after acute and subacute exposure to METH by western blotting. Male Sprague-Dawley rats were injected intraperitoneally with a single dose of 8 mg/kg METH, 4 mg/kg/day METH for 14 days and saline in acute, subacute, and control groups, respectively. A significant increase in NMDAR1 immunoreactive protein was found in frontal cortex in the subacute group (P=.036 but not in the acute group (P=.580. Moreover, a significant increase in NMDAR1 was also observed in striatum in both acute (P=.025 and subacute groups (P=.023. However, no significant differences in NMDAR1 in hippocampal formation were observed in either acute or subacute group. The results suggest that an upregulation of NMDA receptor expression may be a consequence of glutamatergic dysfunction induced by METH.

  2. Genotype and toxicity relationships among Hyalella azteca: I. Acute exposure to metals or low pH

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Y.; Guttman, S.I.; Oris, J.T.; Bailer, A.J.

    2000-05-01

    Comparative genotype and toxin interactions at three polymorphic enzyme loci were examined in a laboratory population of amphipods (Hyalella azteca) during acute exposure to cadmium, zinc, copper, lead, or low pH. Significant toxin-genotype interactions were observed using logistic regression to model mortality in ten of 15 analyses. Both stressor-specific and nonspecific modes of selection were observed. In general, low pH selected for different genotypes than those selected by metals, especially zinc. Different modes of selection were also observed when amphipods were exposed to different metals. These results suggest that exposure to low pH would significantly reduce the ability of H. azteca to survive subsequent contamination by metals; exposure to stressors in the reverse order would also compromise a population's chance of survival. A genetic distance analysis showed that the magnitude of genetic differentiation consistently increased among survivors compared with that of the initial populations. These increases in genetic divergence estimates suggest that acute exposure to metals or low pH may have an evolutionarily significant impact on the species. They also suggest that both genotype frequency and genetic distance measures (based on allozyme data) may be used as bioindicators for environmental monitoring programs. Validation of such bioindicators requires an understanding of the population's genetic background, genetic structure, and history.

  3. Chronic and Acute Ozone Exposure in the Week Prior to Delivery Is Associated with the Risk of Stillbirth

    Directory of Open Access Journals (Sweden)

    Pauline Mendola

    2017-07-01

    Full Text Available Chronic and acute air pollution has been studied in relation to stillbirth with inconsistent findings. We examined stillbirth risk in a retrospective cohort of 223,375 singleton deliveries from 12 clinical sites across the United States. Average criteria air pollutant exposure was calculated using modified Community Multiscale Air Quality models for the day of delivery and each of the seven days prior, whole pregnancy, and first trimester. Poisson regression models using generalized estimating equations estimated the relative risk (RR of stillbirth and 95% confidence intervals (CI in relation to an interquartile range increase in pollutant with adjustment for temperature, clinical, and demographic factors. Ozone (O3 was associated with a 13–22% increased risk of stillbirth on days 2, 3, and 5–7 prior to delivery in single pollutant models, and these findings persisted in multi-pollutant models for days 5 (RR = 1.22, CI = 1.07–1.38 and 6 (RR = 1.18, CI = 1.04–1.33. Whole pregnancy and first trimester O3 increased risk 18–39% in single pollutant models. Maternal asthma increased stillbirth risk associated with chronic PM2.5 and carbon monoxide exposures. Both chronic and acute O3 exposure consistently increased stillbirth risk, while the role of other pollutants varied. Approximately 8000 stillbirths per year in the US may be attributable to O3 exposure.

  4. Human Rights Engagement and Exposure: New Scales to Challenge Social Work Education

    Science.gov (United States)

    McPherson, Jane; Abell, Neil

    2012-01-01

    Objectives: Advancing human rights is a core competency of U.S. social work education; yet, human rights attitudes and behaviors have never been measured in the social work literature. Thus, this article describes the development and initial validation of two scales, Human Rights Engagement in Social Work (HRESW) and Human Rights Exposure in…

  5. Human Rights Engagement and Exposure: New Scales to Challenge Social Work Education

    Science.gov (United States)

    McPherson, Jane; Abell, Neil

    2012-01-01

    Objectives: Advancing human rights is a core competency of U.S. social work education; yet, human rights attitudes and behaviors have never been measured in the social work literature. Thus, this article describes the development and initial validation of two scales, Human Rights Engagement in Social Work (HRESW) and Human Rights Exposure in…

  6. Human T cell recognition of the blood stage antigen Plasmodium hypoxanthine guanine xanthine phosphoribosyl transferase (HGXPRT in acute malaria

    Directory of Open Access Journals (Sweden)

    Woodberry Tonia

    2009-06-01

    Full Text Available Abstract Background The Plasmodium purine salvage enzyme, hypoxanthine guanine xanthine phosphoribosyl transferase (HGXPRT can protect mice against Plasmodium yoelii pRBC challenge in a T cell-dependent manner and has, therefore, been proposed as a novel vaccine candidate. It is not known whether natural exposure to Plasmodium falciparum stimulates HGXPRT T cell reactivity in humans. Methods PBMC and plasma collected from malaria-exposed Indonesians during infection and 7–28 days after anti-malarial therapy, were assessed for HGXPRT recognition using CFSE proliferation, IFNγ ELISPOT assay and ELISA. Results HGXPRT-specific T cell proliferation was found in 44% of patients during acute infection; in 80% of responders both CD4+ and CD8+ T cell subsets proliferated. Antigen-specific T cell proliferation was largely lost within 28 days of parasite clearance. HGXPRT-specific IFN-γ production was more frequent 28 days after treatment than during acute infection. HGXPRT-specific plasma IgG was undetectable even in individuals exposed to malaria for at least two years. Conclusion The prevalence of acute proliferative and convalescent IFNγ responses to HGXPRT demonstrates cellular immunogenicity in humans. Further studies to determine minimal HGXPRT epitopes, the specificity of responses for Plasmodia and associations with protection are required. Frequent and robust T cell proliferation, high sequence conservation among Plasmodium species and absent IgG responses distinguish HGXPRT from other malaria antigens.

  7. Critical role of matrix metalloproteinase-9 in acute cold exposure-induced stroke in renovascular hypertensive rats.

    Science.gov (United States)

    Li, Chunguang; Li, Xiangpen; Shen, Qingyu; Li, Yi; He, Lei; Li, Mei; Tang, Yamei; Wang, Yidong; He, Qingyu; Peng, Ying

    2013-11-01

    Our objectives are to investigate the role of MMP-9 in cold exposure-induced stroke and assess the preventive effect of doxycycline, a total of 200 rats were assigned to a control group, sham group, 2-kidney, 2-clip (2K-2C) group, and doxycycline-received 2K-2C group (2K-2C+doxy) (N=50, each), and subsequently, each group were randomly assigned to 2 groups: acute cold exposure (ACE) and nonacute cold exposure (NACE) (N=25, each). After the blood pressure was stabilized, rats were maintained on a 12-h light (22°C)/dark (4°C) cycle (ACE group) or a 12-h light (22°C)/dark (22°C) cycle (NACE group) for 3 cycles. The results showed that ACE upregulated Ang II and MMP-9 protein levels in brains and aortas and considerably enhanced stroke incidence in 2K-2C rats. In contrast, doxycycline treatment prevented upregulation of MMP-9 protein expression and activity in brains and aortas in response to ACE and significantly decreased stroke incidence. These findings suggest that cold exposure-induced MMP-9 via activation of RAS might play a critical role in the initiation of cold exposure-induced stroke during chronic hypertension and doxycycline shows protective effects against cold exposure-induced stroke. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  8. Physiological responses to exposure to carbon dioxide and human bioeffluents

    DEFF Research Database (Denmark)

    Zhang, Xiaojing; Wargocki, Pawel; Lian, Zhiwei

    2015-01-01

    Present paper describes physiological responses as a result of exposures to CO2 (between 500 ppm to 3,000 ppm) with and without bioeffluents. Twenty-five subjects participated. They were exposed in the climate chamber for 255 minutes in groups of five at a time. During exposure, they performed di...

  9. Limiting criteria for human exposure to low humidity indoors

    DEFF Research Database (Denmark)

    Wyon, David; Fang, Lei; Meyer, H.;

    2002-01-01

    % RH. The subjects performed simulated office work throughout each exposure. Building Related Symptom (BRS) intensity was reported on visual-analogue scales. Tests of eye, nose and skin function were applied. In these short exposures subjective discomfort, though significantly increased by low humidity...

  10. Health Risk Evaluations for Ingestion Exposure of Humans to Polonium-210

    Science.gov (United States)

    Scott, Bobby R.

    2007-01-01

    The incident in London during November 2006 involving a lethal intake by Mr. Alexander Litvinenko of the highly-radioactive, alpha-particles-emitting polonium-210 (Po-210) isotope, presumably via ingestion, sparked renewed interest in the area of Po-210 toxicity to humans. This paper is the result of assembling and interpreting existing Po-210 data within the context of what is considered a reliable risk model (hazard-function [HF] model) for characterizing the risk of death from deterministic effects of high alpha radiation doses and dose rates to body organs. The HF model was developed to address radiation exposure scenarios involving combined exposures to alpha, beta, and gamma radiations and can be used in circumstances where only one type of radiation is involved. Under a plausible but not yet validated set of assumptions and using available megabecquerel (Po-210) to gray dose-conversion factors, acute lethality risk vs. dose curves were developed for circumstances of ingestion exposure to Po-210 by humans. Initial risk calculations were carried out for a reference adult male human (a hypothetical 70-kg person). Results were then modified for application to all ages (except the in utero child) via the use of systemic Po-210 burden. Because of the unavailability of acute lethality data derived from human ingestions of high levels of Po-210, plausibility of risk calculations were evaluated based on data from studies of Po-210 injections in animals. The animal data, although limited, were found to be consistent with the theoretical risk calculations. Key findings are as follows: (1) ingestion (or inhalation) of a few tents of a milligram of Po-210 will likely be fatal to all exposed persons. (2) Lethal intakes are expected to involve fatal damage to the bone marrow which is likely to be compounded by damage caused by higher doses to other organs including the kidneys and liver. (3) Lethal intakes are expected to cause severe damage to the kidney, spleen, stomach

  11. Nonthermal Effects of Radar Exposure on Human: A Review Article

    Directory of Open Access Journals (Sweden)

    vida zaroushani

    2014-01-01

    Full Text Available ABSTRACT Microwave is part of the electromagnetic spectrum that has different application such as communications, military, air-traffic Control and etc... Previous studies showed that radar frequency could be a health hazard agent. This review article mentioned some of the studies that investigated non-thermal effects of radar frequencies. Reproductive effects, cancers, blood effects, genetic, adverse immune effects and mental effects are non-thermal effects that presented in this report. There are many unknown aspects of the biological effects and many of them did not determined very well such as oxidative stress and mental effects. Compliance with permissible exposure limits, reduction in exposure, and shielding are some of the controlling methods to protect workers from the exposure of microwave and among them, The use of shielding is a superior method for prevention of microwave exposure and among them, electromagnetic Nano composites shields is appropriate for protection of workers from radar exposure.

  12. Human short-term exposure to electromagnetic fields emitted by mobile phones decreases computer-assisted visual reaction time.

    Science.gov (United States)

    Mortazavi, S M J; Rouintan, M S; Taeb, S; Dehghan, N; Ghaffarpanah, A A; Sadeghi, Z; Ghafouri, F

    2012-06-01

    The worldwide dramatic increase in mobile phone use has generated great concerns about the detrimental effects of microwave radiations emitted by these communication devices. Reaction time plays a critical role in performing tasks necessary to avoid hazards. As far as we know, this study is the first survey that reports decreased reaction time after exposure to electromagnetic fields generated by a high specific absorption rate mobile phone. It is also the first study in which previous history of mobile phone use is taken into account. The aim of this study was to assess both the acute and chronic effects of electromagnetic fields emitted by mobile phones on reaction time in university students. Visual reaction time (VRT) of young university students was recorded with a simple blind computer-assisted-VRT test, before and after a 10 min real/sham exposure to electromagnetic fields of mobile phones. Participants were 160 right-handed university students aged 18-31. To assess the effect of chronic exposures, the reaction time in sham-exposed phases were compared among low level, moderate and frequent users of mobile phones. The mean ± SD reaction time after real exposure and sham exposure were 286.78 ± 31.35 ms and 295.86 ± 32.17 ms (P students did not significantly alter the reaction time either in talk or in standby mode. The reaction time either in talk or in standby mode was shorter in male students. The students' VRT was significantly affected by exposure to electromagnetic fields emitted by a mobile phone. It can be concluded that these exposures cause decreased reaction time, which may lead to a better response to different hazards. In this light, this phenomenon might decrease the chances of human errors and fatal accidents.

  13. Biphasic changes in fetal heart rate variability in preterm fetal sheep developing hypotension after acute on chronic lipopolysaccharide exposure.

    Science.gov (United States)

    Lear, Christopher A; Davidson, Joanne O; Booth, Lindsea C; Wassink, Guido; Galinsky, Robert; Drury, Paul P; Fraser, Mhoyra; Bennet, Laura; Gunn, Alistair J

    2014-08-15

    Perinatal exposure to infection is highly associated with adverse outcomes. Experimentally, acute, severe exposure to gram-negative bacterial lipopolysaccharide (LPS) is associated with increased fetal heart rate variability (FHRV). It is unknown whether FHRV is affected by subclinical infection with or without acute exacerbations. We therefore tested the hypothesis that FHRV would be associated with hypotension after acute on chronic exposure to LPS. Chronically instrumented fetal sheep at 0.7 gestation were exposed to a continuous low-dose LPS infusion (n = 12, 100 ng/kg over 24 h, followed by 250 ng·kg(-1)·24 h(-1) for a further 96 h) or the same volume of saline (n = 10). Boluses of either 1 μg LPS or saline were given at 48, 72, and 96 h. Low-dose infusion was not associated with hemodynamic or FHRV changes. The first LPS bolus was associated with tachycardia and suppression of nuchal electromyographic activity in all fetuses. Seven of twelve fetuses developed hypotension (a fall in mean arterial blood pressure ≥5 mmHg). FHRV was transiently increased only at the onset of hypotension, in association with increased cytokine induction and electroencephalogram suppression. FHRV then fell before the nadir of hypotension, with transient suppression of short-term FHRV. After the second LPS bolus, the hypotension group showed a biphasic pattern of a transient increase in FHRV followed by more prolonged suppression. These findings suggest that infection-related hypotension in the preterm fetus mediates the transient increase in FHRV and that repeated exposure to LPS leads to progressive loss of FHRV.

  14. Sensitivity of a green alga to atrazine is not enhanced by previous acute exposure.

    Science.gov (United States)

    Baxter, Leilan; Brain, Richard; Prosser, Ryan; Solomon, Keith; Hanson, Mark

    2013-10-01

    Exposure to atrazine in small lotic systems can be episodic, with short-term pulses (peaks) followed by lower, decreasing concentrations. Algae and macrophytes recover rapidly from pulsed exposure to atrazine, but reported observations of population response to subsequent exposures are minimal and inconclusive. Consequently, the sensitivity of Pseudokirchneriella subcapitata to atrazine following a pulsed exposure was assessed. Exposure concentrations reflected amplifications of those observed in streams from highly vulnerable watersheds in regions of intense use. Initial pulsed atrazine exposure at 0, 150 or 300 μg/L for 24-h was followed by 72-h exposure to 0, 5, 10, 25, or 50 μg/L. Measured responses were cell density, growth rate, chlorophyll-a, and maximum quantum yield of photosystem II. Algal recovery was rapid and prior pulsed exposure to atrazine did not significantly affect subsequent sensitivity (EC10s, EC25s) for any endpoint, indicating no changes in tolerance at the population level for this species.

  15. SYSTEMIC IMBALANCE OF ESSENTIAL METALS AND CARDIAC GENE EXPRESSION IN RATS FOLLOWING ACUTE PULMONARY ZINC EXPOSURE

    Science.gov (United States)

    We have recently demonstrated that PM containing water-soluble zinc may cause cardiac injury following pulmonary exposure. To investigate if pulmonary zinc exposure causes systemic metal imbalance and direct cardiac effects, we intratracheally (IT) instilled male Wistar Kyoto (WK...

  16. Effects on Pharmacokinetics of Propranolol and Other Factors in Rats After Acute Exposure to High Altitude at 4,010 m.

    Science.gov (United States)

    Wenbin, Li; Rong, Wang; Hua, Xie; Juanhong, Zhang; Xiaoyu, Wu; Zhengping, Jia

    2015-05-01

    A series of pathological, physiological, and biochemical changes, even anatomical histological changes happen while humans arrive at the high plateau region from plain area. There is a certain relationship between the body's compensatory or decompensated adjustments to the environment and the changes of absorption, distribution, metabolism, and excretion of drugs. The objective of the study is to observe the effects of acute exposure to high altitude at 4,010 m on pharmacokinetics of propranolol in rats, and to provide basis and new ideas to adjust drug dosage and administration, so as to promote rational drug use in high altitude. 28 healthy male wistar rats were randomly divided into four groups, group A and B which were in plain area; group C and D which were acutely exposed to high altitude by aviation; group A and C were used for pharmacokinetics determination of propranolol, while group B and D had no drug administration for physiological and pathological changes research at high altitude. The pharmacokinetics of propranolol significantly changed; area under curve, C max (the peak concentration), mean residence time, and t 1/2 (the biological half-life) increased significantly by 481.72, 398.94, 44.87, and 58.77 %, respectively; clearance and V (apparent volume of distribution) decreased by 81.50 and 70.56 %, respectively, after acute exposure to high altitude at 4,010 m; Analytic results show that pH, buffer base, base excess, ctCO2 (content of total carbon dioxide), sO2 (oxygen saturation of arterial blood), pO2 (oxygen tension of arterial blood), and cNa(+) severely decreased by 2.43, 630.00, 311.00, 11.48, 91.38, 76.22, and 2.82 %, respectively, while pCO2 (carbon dioxide tension of arterial blood) and cCl(-) significantly increased by 47.40 and 6.76 %. Lactate dehydrogenase and total protein significantly decreased by 58.44 and 26.82 %, while total bilirubin and alkaline phosphatase severely increased by 338 and 24.94 % after acute exposure to high

  17. Current issues in human lead exposure and regulation of lead.

    Science.gov (United States)

    Davis, J M; Elias, R W; Grant, L D

    1993-01-01

    Concern about lead as a significant public health problem has increased as epidemiological and experimental evidence has mounted regarding adverse health effects at successively lower levels of lead exposure. This concern has led to downward revision of criteria for acceptable blood lead concentrations to the 10 micrograms/dL mark now designated by EPA as a target level for regulatory development and enforcement/clean-up purposes. Much progress has been made in reducing lead exposures during the past 10-15 years, with marked declines evident both in air lead and blood lead concentrations in parallel to the phase-down of lead in gasoline and notable decreases in food lead exposure due to elimination of lead soldered cans by U.S. food processors. With the lessening of exposure from these sources, the importance of other components of multimedia exposure pathways has grown and stimulated increasing regulatory attention and abatement efforts to reduce health risks associated with lead exposure from drinking water, from lead-based paint, and from household dust and soil contaminated by deteriorating paint, smelter emissions, or various other sources. Increasing attention is also being accorded to reduction of occupational lead exposures (including those related to lead abatement activities), with particular concern for protection of men and women during their reproductive years.

  18. Is hair analysis for dialkyl phosphate metabolites a suitable biomarker for assessing past acute exposure to organophosphate pesticides?

    Science.gov (United States)

    Tsatsakis, A M; Tutudaki, M; Tzatzarakis, M N; Dawson, A; Mohamed, F; Christaki, M; Alegakis, A K

    2012-03-01

    In the present paper, the possibility to use dialkyl phosphate metabolites (DAPs) hair segmental analysis as a biomarker of past acute exposure to organophosphates is examined. Hair samples of four acute poisoning survivors were collected and segmental hair analysis was performed. The total hair samples were divided to 1 cm segments and analysed by gas chromatography-mass spectrometry (GC-MS) for the presence of four DAP metabolites, dimethyl phosphate (DMP), diethyl phosphate (DEP), diethyl thiophosphate (DETP) and diethyl dithiophosphate (DEDTP). Results were examined under the light of pesticide type and time of hair sample collection. Although DAPs were detected all along the hair shaft, higher concentrations (peaks) were detected in the segments proximate to the suicide period. It was also observed that the elevated concentrations of the present metabolites corresponded to the ones produced by the ingested parent compound. Conclusively, measurements of DAPs in the appropriate hair segments of OP-poisoned patients can be used for assessing past acute exposure to organophosphates in certain cases.

  19. Human exposure to acrolein: Time-dependence and individual variation in eye irritation.

    Science.gov (United States)

    Claeson, Anna-Sara; Lind, Nina

    2016-07-01

    The aim of the study was to examine the time dependence on sensory irritation detection following exposure to threshold levels of acrolein, in humans. The exposures occurred in an exposure chamber and the subjects were breathing fresh air through a mask that covered the nose and mouth. All participants participated in four exposure conditions, of which three consisted of a mixture of acrolein and heptane and one of only heptane. Exposure to acrolein at a concentration half of the TLV-C lead to sensory irritation. The perceived sensory irritation resulted in both increased detectability and sensory irritation after about 6.8min of exposure in 58% of the participants. The study confirm the previously suggested LOAEL of about 0.34mg/m(3) for eye irritation due to acrolein exposure. The sensory irritation was still significant 10min after exposure. These results have implications for risk assessment and limit setting in occupational hygiene.

  20. Effect of acute exposure to nonylphenol on biochemical, hormonal, and hematological parameters and muscle tissues residues of Nile tilapia; Oreochromis niloticus

    Directory of Open Access Journals (Sweden)

    Hager Tarek H. Ismail

    2016-06-01

    Full Text Available Aim: This study is aimed to evaluate some biochemical, hormonal, hematological, and histopathological changes in Nile tilapia, Oreochromis niloticus, after acute exposure to nonylphenol (NP. In addition to detection of NP residues in the fish, muscle tissues for human health concern. Materials and Methods: A total of 90 apparently healthy Nile tilapia, O. niloticus, were randomly divided into three equal groups; each containing 30 fish (three replicates. Groups 1 and 2 kept as a control and solvent control (acetone, respectively, and Group 3 exposed to NP at a dose level of 500 μg/L water for 7 successive days. Blood and tissue samples were collected 2 times randomly from each group after 7 days from fish exposure to NP and 10 days from exposure stopping. Results: Fish exposed to NP Group 3 showed anorexia, sluggish movement, erythema of the skin, areas of scales loss, and hemorrhagic ulcers in some areas of body region leading to exposing the viscera. Biochemical results revealed a significant increase in serum total proteins and globulins levels, a highly significant increase in serum alanine aminotransferase and aspartate aminotransferase activities, triglycerides, cholesterol, and creatinine levels, insignificant increase in serum uric acid level, and a highly significant decrease in serum testosterone and estradiol-β17 levels in Group 3 in compare with the control group. Histopathological finding confirms these results. While hematological results of the same group revealed a significant increase in red blood cells count and packed cell volume value, insignificant increase in hemoglobin concentration, leukopenia, lymphopenia, and monocytopenia in compared with the control group. All of these changes appeared after 7 days from fish exposure to NP. Most of these alterations returned toward the normal level after 10 days from stopping exposure to NP. NP residues detected in fish muscle tissues of Group 3 during exposure and after stopping

  1. Response of Differentiated Human Airway Epithelia to Alcohol Exposure and Klebsiella pneumoniae Challenge

    Directory of Open Access Journals (Sweden)

    Sammeta V. Raju

    2013-07-01

    Full Text Available Alcohol abuse has been associated with increased susceptibility to pulmonary infection. It is not fully defined how alcohol contributes to the host defense compromise. Here primary human airway epithelial cells were cultured at an air-liquid interface to form a differentiated and polarized epithelium. This unique culture model allowed us to closely mimic lung infection in the context of alcohol abuse by basolateral alcohol exposure and apical live bacterial challenge. Application of clinically relevant concentrations of alcohol for 24 h did not significantly alter epithelial integrity or barrier function. When apically challenged with viable Klebsiella pneumoniae, the cultured epithelia had an enhanced tightness which was unaffected by alcohol. Further, alcohol enhanced apical bacterial growth, but not bacterial binding to the cells. The cultured epithelium in the absence of any treatment or stimulation had a base-level IL-6 and IL-8 secretion. Apical bacterial challenge significantly elevated the basolateral secretion of inflammatory cytokines including IL-2, IL-4, IL-6, IL-8, IFN-γ, GM-CSF, and TNF-α. However, alcohol suppressed the observed cytokine burst in response to infection. Addition of adenosine receptor agonists negated the suppression of IL-6 and TNF-α. Thus, acute alcohol alters the epithelial cytokine response to infection, which can be partially mitigated by adenosine receptor agonists.

  2. Acute Free-Iron Exposure Does Not Explain the Impaired Haemorheology Associated with Haemochromatosis.

    Directory of Open Access Journals (Sweden)

    Antony P McNamee

    Full Text Available Given the severity of the current imbalance between blood donor supply and recipient demand, discarded blood drawn from the routine venesections of haemochromatosis (HFE-HH patients may serve as a valuable alternative source for blood banks and transfusion. We investigated whether functional or biochemical differences existed between HFE-HH and control blood samples, with particular focus upon the haemorheological properties, to investigate the viability of venesected blood being subsequently harvested for blood products.Blood samples were collected from HFE-HH patients undergoing venesection treatment (n = 19 and healthy volunteers (n = 8. Moreover, a second experiment investigated the effects of a dose-response of iron (0, 40, 80, 320 mM FeCl3 on haemorheology in healthy blood samples (n = 7. Dependent variables included basic haematology, iron status, haematocrit, red blood cell (RBC aggregation (native and standardised haematocrit and "aggregability" (RBC tendency to aggregate in a standard aggregating medium; 0.4 L/L haematocrit in a Dx70, and RBC deformability.Indices of RBC deformability were significantly decreased for HFE-HH when compared with healthy controls: RBC deformability was significantly decreased at 1-7 Pa (p < 0.05, and the shear stress required for half maximal deformability was significantly increased (p < 0.05 for HFE-HH. RBC aggregation in plasma was significantly increased (p < 0.001 for HFE-HH, although when RBC were suspended in plasma-free Dx70 no differences were detected. No differences in RBC deformability or RBC aggregation/aggregability were detected when healthy RBC were incubated with varying dose of FeCl3.HFE-HH impairs the haemorheological properties of blood; however, RBC aggregability was similar between HFE-HH and controls when cells were suspended in a plasma-free medium, indicating that plasma factor(s may explain the altered haemorheology in HFE-HH patients. Acute exposure to elevated iron levels does

  3. Tumor promotion by exposure to radiofrequency electromagnetic fields below exposure limits for humans.

    Science.gov (United States)

    Lerchl, Alexander; Klose, Melanie; Grote, Karen; Wilhelm, Adalbert F X; Spathmann, Oliver; Fiedler, Thomas; Streckert, Joachim; Hansen, Volkert; Clemens, Markus

    2015-04-17

    The vast majority of in vitro and in vivo studies did not find cancerogenic effects of exposure to electromagnetic fields (RF-EMF), i.e. emitted by mobile phones and base stations. Previously published results from a pilot study with carcinogen-treated mice, however, suggested tumor-promoting effects of RF-EMF (Tillmann et al., 2010). We have performed a replication study using higher numbers of animals per group and including two additional exposure levels (0 (sham), 0.04, 0.4 and 2 W/kg SAR). We could confirm and extend the originally reported findings. Numbers of tumors of the lungs and livers in exposed animals were significantly higher than in sham-exposed controls. In addition, lymphomas were also found to be significantly elevated by exposure. A clear dose-response effect is absent. We hypothesize that these tumor-promoting effects may be caused by metabolic changes due to exposure. Since many of the tumor-promoting effects in our study were seen at low to moderate exposure levels (0.04 and 0.4 W/kg SAR), thus well below exposure limits for the users of mobile phones, further studies are warranted to investigate the underlying mechanisms. Our findings may help to understand the repeatedly reported increased incidences of brain tumors in heavy users of mobile phones.

  4. Campylobacter fetus infections in humans : exposure and disease

    NARCIS (Netherlands)

    Wagenaar, Jaap A; van Bergen, Marcel A P; Blaser, Martin J; Tauxe, Robert V; Newell, Diane G; van Putten, Jos P M

    2014-01-01

    Campylobacter fetus can cause intestinal illness and, occasionally, severe systemic infections. Infections mainly affect persons at higher risk, including elderly and immunocompromised individuals and those with occupational exposure to infected animals. Outbreaks are infrequent but have provided in

  5. Climate change impacts on human exposures to air pollution

    Science.gov (United States)

    This is an abstract for a presentations at the Annual Conference of the International Society on Exposure Science and Environmental Epidemiology. This presentation will serve as an introduction to the symposium.

  6. The use of self-reported symptoms as a proxy for acute organophosphate poisoning after exposure to chlorpyrifos 50 % plus cypermethrin 5 % among Nepali farmers

    DEFF Research Database (Denmark)

    Kofod, Dea Haagensen; Jørs, Erik; Varma, Anshu

    2016-01-01

    cholinesterase (PchE) activity, in addition to the symptoms, when assessing occupational acute pesticide poisoning. This study evaluated self-reported symptoms as a proxy for acute organophosphate poisoning among Nepali farmers by examining self-reported acute organophosphate poisoning symptoms and PchE activity......%: moderately hazardous) spray session or a 2-h placebo spray session, and after 7 days' washout, the farmers were assigned to the other spray session. Before and after each spray session farmers were interviewed about acute organophosphate poisoning symptoms and PchE activity was measured. Analyses were...... symptoms among the farmers regardless of organophosphate exposure or poisoning. Thus, self-reported acute organophosphate symptoms seem to be a poor proxy for acute organophosphate poisoning as the occurrence of these symptoms is not necessarily associated with acute organophosphate poisoning. TRIAL...

  7. Integrating Human Indoor Air Pollutant Exposure within Life Cycle Impact Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hellweg, Stefanie; Demou, Evangelia; Bruzzi, Raffaella; Meijer, Arjen; Rosenbaum, Ralph K.; Huijbregts, Mark A.J.; McKone, Thomas E.

    2008-12-21

    Neglecting health effects from indoor pollutant emissions and exposure, as currently done in Life Cycle Assessment (LCA), may result in product or process optimizations at the expense of workers? or consumers? health. To close this gap, methods for considering indoor exposure to chemicals are needed to complement the methods for outdoor human exposure assessment already in use. This paper summarizes the work of an international expert group on the integration of human indoor and outdoor exposure in LCA, within the UNEP/SETAC Life Cycle Initiative. A new methodological framework is proposed for a general procedure to include human-health effects from indoor exposure in LCA. Exposure models from occupational hygiene and household indoor air quality studies and practices are critically reviewed and recommendations are provided on the appropriateness of various model alternatives in the context of LCA. A single-compartment box model is recommended for use as a default in LCA, enabling one to screen occupational and household exposures consistent with the existing models to assess outdoor emission in a multimedia environment. An initial set of model parameter values was collected. The comparison between indoor and outdoor human exposure per unit of emission shows that for many pollutants, intake per unit of indoor emission may be several orders of magnitude higher than for outdoor emissions. It is concluded that indoor exposure should be routinely addressed within LCA.

  8. Pesticide Flow Analysis to Assess Human Exposure in Greenhouse Flower Production in Colombia

    Directory of Open Access Journals (Sweden)

    Claudia R. Binder

    2013-03-01

    Full Text Available Human exposure assessment tools represent a means for understanding human exposure to pesticides in agricultural activities and managing possible health risks. This paper presents a pesticide flow analysis modeling approach developed to assess human exposure to pesticide use in greenhouse flower crops in Colombia, focusing on dermal and inhalation exposure. This approach is based on the material flow analysis methodology. The transfer coefficients were obtained using the whole body dosimetry method for dermal exposure and the button personal inhalable aerosol sampler for inhalation exposure, using the tracer uranine as a pesticide surrogate. The case study was a greenhouse rose farm in the Bogota Plateau in Colombia. The approach was applied to estimate the exposure to pesticides such as mancozeb, carbendazim, propamocarb hydrochloride, fosetyl, carboxin, thiram, dimethomorph and mandipropamide. We found dermal absorption estimations close to the AOEL reference values for the pesticides carbendazim, mancozeb, thiram and mandipropamide during the study period. In addition, high values of dermal exposure were found on the forearms, hands, chest and legs of study participants, indicating weaknesses in the overlapping areas of the personal protective equipment parts. These results show how the material flow analysis methodology can be applied in the field of human exposure for early recognition of the dispersion of pesticides and support the development of measures to improve operational safety during pesticide management. Furthermore, the model makes it possible to identify the status quo of the health risk faced by workers in the study area.

  9. Human exposure to pulsed fields in the frequency range from 6 to 100 GHz

    Science.gov (United States)

    Laakso, Ilkka; Morimoto, Ryota; Heinonen, Juhani; Jokela, Kari; Hirata, Akimasa

    2017-09-01

    Restrictions on human exposure to electromagnetic waves at frequencies higher than 3-10 GHz are defined in terms of the incident power density to prevent excessive temperature rise in superficial tissue. However, international standards and guidelines differ in their definitions of how the power density is interpreted for brief exposures. This study investigated how the temperature rise was affected by exposure duration at frequencies higher than 6 GHz. Far-field exposure of the human face to pulses shorter than 10 s at frequencies from 6 to 100 GHz was modelled using the finite-difference time-domain method. The bioheat transfer equation was used for thermal modelling. We investigated the effects of frequency, polarization, exposure duration, and depth below the skin surface on the temperature rise. The results indicated limitations in the current human exposure guidelines and showed that radiant exposure, i.e. energy absorption per unit area, can be used to limit temperature rise for pulsed exposure. The data are useful for the development of human exposure guidelines at frequencies higher than 6 GHz.

  10. Pesticide flow analysis to assess human exposure in greenhouse flower production in Colombia.

    Science.gov (United States)

    Lesmes-Fabian, Camilo; Binder, Claudia R

    2013-03-25

    Human exposure assessment tools represent a means for understanding human exposure to pesticides in agricultural activities and managing possible health risks. This paper presents a pesticide flow analysis modeling approach developed to assess human exposure to pesticide use in greenhouse flower crops in Colombia, focusing on dermal and inhalation exposure. This approach is based on the material flow analysis methodology. The transfer coefficients were obtained using the whole body dosimetry method for dermal exposure and the button personal inhalable aerosol sampler for inhalation exposure, using the tracer uranine as a pesticide surrogate. The case study was a greenhouse rose farm in the Bogota Plateau in Colombia. The approach was applied to estimate the exposure to pesticides such as mancozeb, carbendazim, propamocarb hydrochloride, fosetyl, carboxin, thiram, dimethomorph and mandipropamide. We found dermal absorption estimations close to the AOEL reference values for the pesticides carbendazim, mancozeb, thiram and mandipropamide during the study period. In addition, high values of dermal exposure were found on the forearms, hands, chest and legs of study participants, indicating weaknesses in the overlapping areas of the personal protective equipment parts. These results show how the material flow analysis methodology can be applied in the field of human exposure for early recognition of the dispersion of pesticides and support the development of measures to improve operational safety during pesticide management. Furthermore, the model makes it possible to identify the status quo of the health risk faced by workers in the study area.

  11. Quantifying fish swimming behavior in response to acute exposure of aqueous copper using computer assisted video and digital image analysis

    Science.gov (United States)

    Calfee, Robin D.; Puglis, Holly J.; Little, Edward E.; Brumbaugh, William G.; Mebane, Christopher A.

    2016-01-01

    Behavioral responses of aquatic organisms to environmental contaminants can be precursors of other effects such as survival, growth, or reproduction. However, these responses may be subtle, and measurement can be challenging. Using juvenile white sturgeon (Acipenser transmontanus) with copper exposures, this paper illustrates techniques used for quantifying behavioral responses using computer assisted video and digital image analysis. In previous studies severe impairments in swimming behavior were observed among early life stage white sturgeon during acute and chronic exposures to copper. Sturgeon behavior was rapidly impaired and to the extent that survival in the field would be jeopardized, as fish would be swept downstream, or readily captured by predators. The objectives of this investigation were to illustrate protocols to quantify swimming activity during a series of acute copper exposures to determine time to effect during early lifestage development, and to understand the significance of these responses relative to survival of these vulnerable early lifestage fish. With mortality being on a time continuum, determining when copper first affects swimming ability helps us to understand the implications for population level effects. The techniques used are readily adaptable to experimental designs with other organisms and stressors.

  12. The effects of acute waterborne exposure to sublethal concentrations of molybdenum on the stress response in rainbow trout, Oncorhynchus mykiss.

    Directory of Open Access Journals (Sweden)

    Chelsea D Ricketts

    Full Text Available To determine if molybdenum (Mo is a chemical stressor, fingerling and juvenile rainbow trout (Oncorhynchus mykiss were exposed to waterborne sodium molybdate (0, 2, 20, or 1,000 mg l-1 of Mo and components of the physiological (plasma cortisol, blood glucose, and hematocrit and cellular (heat shock protein [hsp] 72, hsp73, and hsp90 in the liver, gills, heart, and erythrocytes and metallothionein [MT] in the liver and gills stress responses were measured prior to initiation of exposure and at 8, 24, and 96 h. During the acute exposure, plasma cortisol, blood glucose, and hematocrit levels remained unchanged in all treatments. Heat shock protein 72 was not induced as a result of exposure and there were no detectable changes in total hsp70 (72 and 73, hsp90, and MT levels in any of the tissues relative to controls. Both fingerling and juvenile fish responded with similar lack of apparent sensitivity to Mo exposure. These experiments demonstrate that exposure to waterborne Mo of up to 1,000 mg l(-1 did not activate a physiological or cellular stress response in fish. Information from this study suggests that Mo water quality guidelines for the protection of aquatic life are highly protective of freshwater fish, namely rainbow trout.

  13. Sampling strategies for estimating acute and chronic exposures of pesticides in streams

    Science.gov (United States)

    Crawford, Charles G.

    2004-01-01

    The Food Quality Protection Act of 1996 requires that human exposure to pesticides through drinking water be considered when establishing pesticide tolerances in food. Several systematic and seasonally weighted systematic sampling strategies for estimating pesticide concentrations in surface water were evaluated through Monte Carlo simulation, using intensive datasets from four sites in northwestern Ohio. The number of samples for the strategies ranged from 4 to 120 per year. Sampling strategies with a minimal sampling frequency outside the growing season can be used for estimating time weighted mean and percentile concentrations of pesticides with little loss of accuracy and precision, compared to strategies with the same sampling frequency year round. Less frequent sampling strategies can be used at large sites. A sampling frequency of 10 times monthly during the pesticide runoff period at a 90 km 2 basin and four times monthly at a 16,400 km2 basin provided estimates of the time weighted mean, 90th, 95th, and 99th percentile concentrations that fell within 50 percent of the true value virtually all of the time. By taking into account basin size and the periodic nature of pesticide runoff, costs of obtaining estimates of time weighted mean and percentile pesticide concentrations can be minimized.

  14. An Exploratory Study on the Development of an Animal Model of Acute Pancreatitis Following Nicotine Exposure

    Directory of Open Access Journals (Sweden)

    Chowdhury P

    2003-09-01

    Full Text Available Abstract Cigarette smoking is known to be a major risk factor for pancreatic cancer and pancreatitis is believed to be a predisposed condition for pancreatic cancer. As of this date, there is no established experimental animal model to conduct detailed studies on these two deadly diseases. Our aim is to establish a rodent model by which we can systematically study the pathogenesis of pancreatitis and pancreatic cancer. Methods Adult Male Sprague Dawley rats were exposed to graded doses of nicotine by various routes for periods of three to 16 weeks. Blood samples were measured for hormonal and metabolic parameters. The pancreas was evaluated for histopathological changes and its function was assessed in isolated pancreatic acini upon stimulation with cholecystokinin (CCK or carbachol (Cch. The pancreatic tissue was evaluated further for oncogene expression. Results Body weight, food and fluid intakes, plasma glucose and insulin levels were significantly reduced in animals with nicotine exposure when compared to control. However, CCK and gastrin levels in the blood were significantly elevated. Pancreatic function was decreased significantly with no alteration in CCK receptor binding. Pancreatic histology revealed vacuolation, swelling, cellular pyknosis and karyorrhexis. Mutant oncogene, H-ras, was overexpressed in nicotine-treated pancreatic tissue. Summary and conclusion The results suggest that alterations in metabolic, hormonal and pathologic parameters following nicotine-treatment appear consistent with diagnostic criteria of human pancreatitis. It is proposed that rats could be considered as a potential animal model to study the pathogenesis of pancreatitis.

  15. Acute reinforcing effects of low-dose nicotine nasal spray in humans.

    Science.gov (United States)

    Perkins, K A; Grobe, J E; Caggiula, A; Wilson, A S; Stiller, R L

    1997-02-01

    Tobacco smoking behavior is reinforced by nicotine intake, but there has been little human research examining self-administration of nicotine per se, isolated from tobacco. In this study, 10 smokers (5 men, 5 women) who wanted to quit smoking sampled 0 (placebo), 0.75, and 1.5 ug/kg/spray nicotine via nasal spray during separate lab sessions before engaging in a free choice session, involving ad lib access to all three spray doses. Subjects also ad lib smoked during another session. For the group as a whole, neither nicotine spray dose was self-administered significantly more than placebo during the free choice session, suggesting low abuse potential. However, 4 of 10 subjects self-administered 1.5 ug/kg/spray on more than 50% of all sprays (vs. 33% chance) and were designated nicotine "choosers," while the others were "nonchoosers." Choosers responded to initial nicotine spray exposure during sampling sessions with greater positive subjective effects (similar to their responses to tobacco smoking), smoked more during the ad lib smoking session (i.e., self-administered more nicotine via tobacco smoking), and tended to be more heavily dependent smokers. They did not report greater withdrawal relief or less aversive effects from nicotine, suggesting their greater nicotine choice reflected greater positive reinforcement rather than negative reinforcement. These results are consistent with the few existing studies demonstrating that acute nicotine intake per se, in the absence of tobacco, may be reinforcing in some smokers.

  16. Acute chlorine gas exposure produces transient inflammation and a progressive alteration in surfactant composition with accompanying mechanical dysfunction

    Energy Technology Data Exchange (ETDEWEB)

    Massa, Christopher B.; Scott, Pamela; Abramova, Elena; Gardner, Carol; Laskin, Debra L.; Gow, Andrew J., E-mail: Gow@rci.rutgers.edu

    2014-07-01

    Acute Cl{sub 2} exposure following industrial accidents or military/terrorist activity causes pulmonary injury and severe acute respiratory distress. Prior studies suggest that antioxidant depletion is important in producing dysfunction, however a pathophysiologic mechanism has not been elucidated. We propose that acute Cl{sub 2} inhalation leads to oxidative modification of lung lining fluid, producing surfactant inactivation, inflammation and mechanical respiratory dysfunction at the organ level. C57BL/6J mice underwent whole-body exposure to an effective 60 ppm-hour Cl{sub 2} dose, and were euthanized 3, 24 and 48 h later. Whereas pulmonary architecture and endothelial barrier function were preserved, transient neutrophilia, peaking at 24 h, was noted. Increased expression of ARG1, CCL2, RETLNA, IL-1b, and PTGS2 genes was observed in bronchoalveolar lavage (BAL) cells with peak change in all genes at 24 h. Cl{sub 2} exposure had no effect on NOS2 mRNA or iNOS protein expression, nor on BAL NO{sub 3}{sup −} or NO{sub 2}{sup −}. Expression of the alternative macrophage activation markers, Relm-α and mannose receptor was increased in alveolar macrophages and pulmonary epithelium. Capillary surfactometry demonstrated impaired surfactant function, and altered BAL phospholipid and surfactant protein content following exposure. Organ level respiratory function was assessed by forced oscillation technique at 5 end expiratory pressures. Cl{sub 2} exposure had no significant effect on either airway or tissue resistance. Pulmonary elastance was elevated with time following exposure and demonstrated PEEP refractory derecruitment at 48 h, despite waning inflammation. These data support a role for surfactant inactivation as a physiologic mechanism underlying respiratory dysfunction following Cl{sub 2} inhalation. - Highlights: • Effect of 60 ppm*hr Cl{sub 2} gas on lung inflammation and mechanical function examined. • Pulmonary inflammation is transient and minor.

  17. Slow and stepped re-warming after acute low temperature exposure do not improve survival of Drosophila melanogaster larvae.

    Science.gov (United States)

    Sinclair, Brent J; Rajamohan, Arun

    2008-01-01

    We tested that hypothesis that slow re-warming rates would improve the ability of Drosophila melanogaster Meigen larvae to survive acute low temperature exposure. Four larval stages (1(st), 2(nd), 3(rd) instars and wandering stage 3(rd) instars) of four wild-type strains were exposed to -7 degrees C for periods of time expected to result in 90 % mortality. Larvae were then either directly transferred to their rearing temperature (21 degrees C), or returned to this temperature in a stepwise fashion (pausing at 0 and 15 degrees C) or by slow warming at 1 or 0.1 degrees C/min. We observed a reduced rapid cold-hardening effect and no general increase in survival of acute chilling in larvae re-warmed in a stepwise or slow fashion, and hypothesise that slow re-warming may result in accumulation of further chill injuries.

  18. Cerebrovascular response to acute metabolic acidosis in humans.

    NARCIS (Netherlands)

    Ven, M.T.P. van de; Colier, W.N.J.M.; Kersten, B.T.P.; Oeseburg, B.; Folgering, H.T.M.

    2003-01-01

    OBJECTIVES: Evaluation of the cerebrovascular response (delta CBV/delta PaCO2) during baseline metabolic conditions and acute metabolic acidosis. METHODS: 15 healthy subjects, 5 m, 10 f, 56 +/- 10 yrs were investigated. For acidification, NH4Cl was given orally. CBV was measured using Near Infrared

  19. Human Infection with MERS Coronavirus after Exposure to Infected Camels, Saudi Arabia, 2013

    OpenAIRE

    Memish, Ziad A.; Cotten, Matthew; Meyer, Benjamin; Simon J Watson; Alsahafi, Abdullah J.; Al Rabeeah, Abdullah A.; Corman, Victor Max; Sieberg, Andrea; Makhdoom, Hatem Q.; Assiri, Abdullah; Al Masri, Malaki; Aldabbagh, Souhaib; Bosch, Berend-Jan; Beer, Martin; Müller, Marcel A.

    2014-01-01

    We investigated a case of human infection with Middle East respiratory syndrome coronavirus (MERS-CoV) after exposure to infected camels. Analysis of the whole human-derived virus and 15% of the camel-derived virus sequence yielded nucleotide polymorphism signatures suggestive of cross-species transmission. Camels may act as a direct source of human MERS-CoV infection.

  20. Short-term exposure to ambient particulate matter and emergency ambulance dispatch for acute illness in Japan.

    Science.gov (United States)

    Tasmin, Saira; Ueda, Kayo; Stickley, Andrew; Yasumoto, Shinya; Phung, Vera Ling Hui; Oishi, Mizuki; Yasukouchi, Shusuke; Uehara, Yamato; Michikawa, Takehiro; Nitta, Hiroshi

    2016-10-01

    Short-term exposure to air pollution may be linked to negative health outcomes that require an emergency medical response. However, few studies have been undertaken on this phenomenon to date. The aim of this study therefore was to examine the association between short-term exposure to ambient suspended particulate matter (SPM) and emergency ambulance dispatches (EADs) for acute illness in Japan. Daily EAD data, daily mean SPM and meteorological data were obtained for four prefectures in the Kanto region of Japan for the period from 2007 to 2011. The area-specific association between daily EAD for acute illness and SPM was explored using generalized linear models while controlling for ambient temperature, relative humidity, seasonality, long-term trends, day of the week and public holidays. Stratified analyses were conducted to evaluate the modifying effects of age, sex and medical conditions. Area-specific estimates were combined using meta-analyses. For the total study period the mean level of SPM was 23.7μg/m(3). In general, higher SPM was associated with a significant increase in EAD for acute illness [estimated pooled relative risk (RR): 1.008, 95% CI: 1.007 to 1.010 per 10μg/m(3) increase in SPM at lag 0-1]. The effects of SPM on EAD for acute illness were significantly greater for moderate/mild medical conditions (e.g. cases that resulted in 3weeks hospitalization or which resulted in death). Using EAD data, this study has shown the adverse health effects of ambient air pollution. This highlights the importance of reducing the level of air pollution in order to maintain population health and well-being.

  1. Effects of acute versus repeated cocaine exposure on the expression of endocannabinoid signaling-related proteins in the mouse cerebellum

    Directory of Open Access Journals (Sweden)

    Ana ePalomino

    2014-03-01

    Full Text Available Growing awareness of cerebellar involvement in addiction is based on the cerebellum’s intermediary position between motor and reward, potentially acting as an interface between motivational and cognitive functions. Here, we examined the impact of acute and repeated cocaine exposure on the two main signaling systems in the mouse cerebellum: the endocannabinoid (eCB and glutamate systems. To this end, we investigated whether eCB signaling-related gene and protein expression (CB1 receptors and enzymes that produce (DAGLα/β and NAPE-PLD and degrade (MAGL and FAAH eCB were altered. In addition, we analyzed the gene expression of relevant components of the glutamate signaling system (glutamate synthesizing enzymes LGA and KGA, mGluR3/5 metabotropic receptors, and NR1/2A/2B/2C-NMDA and GluR1/2/3/4-AMPA ionotropic receptor subunits and the gene expression of tyrosine hydroxylase (TH, the rate-limiting enzyme in catecholamine biosynthesis, because noradrenergic terminals innervate the cerebellar cortex. Results indicated that acute cocaine exposure decreased DAGLα expression, suggesting a down-regulation of 2-AG production, as well as gene expression of TH, KGA, mGluR3 and all ionotropic receptor subunits analyzed in the cerebellum. The acquisition of conditioned locomotion and sensitization after repeated cocaine exposure were associated with an increased NAPE-PLD/FAAH ratio, suggesting enhanced anandamide production, and a decreased DAGLβ/MAGL ratio, suggesting decreased 2-AG generation. Repeated cocaine also increased LGA gene expression but had no effect on glutamate receptors. These findings indicate that acute cocaine modulates the expression of the eCB and glutamate systems. Repeated cocaine results in normalization of glutamate receptor expression, although sustained changes in eCB is observed. We suggest that cocaine-induced alterations to cerebellar eCB should be considered when analyzing the adaptations imposed by psychostimulants that

  2. Human internal and external exposure to PBDEs - A review of levels and sources

    DEFF Research Database (Denmark)

    Frederiksen, Marie; Vorkamp, Katrin; Thomsen, Marianne

    2009-01-01

    ingest more dust than adults. Infants are also exposed to PBDEs via breast milk. Internal human exposure has generally been found to be one order of magnitude larger in North America than in Europe and Asia. These differences cannot solely be explained by the dietary intake as meat products are the only......This paper reviews the existing literature on human exposure to polybrominated diphenyl ethers (PBDEs), with particular focus on external exposure routes (e.g. dust, diet, and air) and the resulting internal exposure to PBDEs (e.g. breast milk and blood). Being lipophilic and persistent organic...... compounds, PBDEs accumulate in lipid-rich tissues. Consequently, food items like fish from high trophic levels or lipid-rich oils have been found to contain relatively high concentrations of PBDEs, thus presenting an important exposure pathway to humans. The presence of PBDEs in various products of everyday...

  3. Long-term ethanol exposure decreases the endotoxin-induced hepatic acute phase response in rats

    DEFF Research Database (Denmark)

    Glavind, Emilie; Vilstrup, Hendrik; Grønbaek, Henning

    2017-01-01

    -fed rats showed either no liver histopathological changes or varying degrees of steatosis. Ethanol feeding decreased the spontaneous liver mRNA expression of the prevailing acute phase protein alpha-2-macroglobulin by 30% (Ptumor necrosis factor...... an induced acute phase response is impaired in long-term ethanol-fed rats. METHODS: For six weeks, rats were either fed a Lieber-DeCarli ethanol-containing (36% as calories) liquid diet ad libitum or calorically pair-fed. Then, the rats were injected intraperitoneally with a low-dose of lipopolysaccharide...... (LPS) (0.5 mg/kg) to induce an acute phase response. Two hours after LPS, we measured the plasma concentrations of an array of inflammatory cytokines. Twenty-four hours after LPS, we measured the hepatic mRNA expression and serum concentrations of prominent rat acute phase proteins. RESULTS: Ethanol...

  4. Differences in inflammation and acute phase response but similar genotoxicity in mice following pulmonary exposure to graphene oxide and reduced graphene oxide

    DEFF Research Database (Denmark)

    Bengtson, Stefan; Knudsen, KB; Kyjovska, ZO

    2017-01-01

    the lowest dose was evaluated. GO induced a strong acute inflammatory response together with a pulmonary (Serum-Amyloid A, Saa3) and hepatic (Saa1) acute phase response. rGO induced less acute, but a constant and prolonged inflammation up to day 90. Lung histopathology showed particle agglomerates at day 90...... without signs of fibrosis. In addition, DNA damage in BAL cells was observed across time points and doses for both GO and rGO. In conclusion, pulmonary exposure to GO and rGO induced inflammation, acute phase response and genotoxicity but no fibrosis.......We investigated toxicity of 2-3 layered >1 μm sized graphene oxide (GO) and reduced graphene oxide (rGO) in mice following single intratracheal exposure with respect to pulmonary inflammation, acute phase response (biomarker for risk of cardiovascular disease) and genotoxicity. In addition, we...

  5. Effects of Acute Oral 5-aminotetrazole (5-AT) Exposure to Rats (Rattus norvegicus)

    Science.gov (United States)

    2015-02-12

    Micronucleus Assay (MNA) Male rats from the 5-AT study (three highest dose groups and the vehicle control) were tested for DNA damage in their peripheral...Dose Test (Sub-acute Study) - Sperm Collection and Analysis 09/25/2013 10/07/2013 14-Day Repeated Dose Test (Sub-acute Study) - Micronucleus Assay...2015 Prepared by: Valerie H Adams, Ph.D. Approved for public release; distribution unlimited. Specialty: 500C Toxicity Test Toxicity Report No. S

  6. 40 CFR 26.1203 - Prohibition of research involving intentional exposure of any human subject who is a pregnant...

    Science.gov (United States)

    2010-07-01

    ... intentional exposure of any human subject who is a pregnant woman (and therefore her fetus), a nursing woman... Exposure of Human Subjects who are Children or Pregnant or Nursing Women § 26.1203 Prohibition of research involving intentional exposure of any human subject who is a pregnant woman (and therefore her fetus),...

  7. Renal effects of acute exposure to toluene. A controlled clinical trial

    DEFF Research Database (Denmark)

    Nielsen, H K; Krusell, Lars Romer; Bælum, Jesper

    1985-01-01

    Urinary excretion rates of beta 2-microglobulin and albumin were measured in 43 male printing trade workers and 43 age-matched male controls before and during exposure to toluene, 382 mg/m3, for 6 1/2 hours in a climate chamber. There were no significant changes in renal excretion rates of albumin...... and beta 2-microglobulin during toluene exposure indicating that no causal relationship exists between moderate exposure to organic solvents and renal injury....

  8. Probabilistic assessment of the cumulative dietary acute exposure of the population of Denmark to organophosphorus and carbamate pesticides

    DEFF Research Database (Denmark)

    Jensen, Bodil Hamborg; Petersen, Annette; Christensen, Tue

    2009-01-01

    Organophosphorus and carbamate pesticides are acetylcholinesterase-inhibiting pesticides and as such have a common mode of action. We assessed the cumulative acute exposure of the population of Denmark to 25 organophosphorus and carbamate pesticide residues from the consumption of fruit, vegetables...... the nationwide dietary survey conducted in 2000-2002. Contributions from 43 commodities were included in the calculations. We used the relative potency factor (RPF) approach to normalize the toxicity of the various organophosphorus and carbamate pesticides to the two index compounds chlorpyriphos...

  9. Reducing human exposure to aflatoxin through the use of clay: a review.

    Science.gov (United States)

    Phillips, T D; Afriyie-Gyawu, E; Williams, J; Huebner, H; Ankrah, N-A; Ofori-Adjei, D; Jolly, P; Johnson, N; Taylor, J; Marroquin-Cardona, A; Xu, L; Tang, L; Wang, J-S

    2008-02-01

    Innovative sorption strategies for the detoxification of aflatoxins have been developed. NovaSil clay (NS) has been shown to prevent aflatoxicosis in a variety of animals when included in their diet. Results have shown that NS clay binds aflatoxins with high affinity and high capacity in the gastrointestinal tract, resulting in a notable reduction in the bioavailability of these toxins without interfering with the utilization of vitamins and other micronutrients. This strategy is being evaluated as a potential remedy for acute aflatoxicosis, and as a sustainable human intervention for aflatoxins via the diet. Phase I and II clinical trials confirmed the apparent safety of NS for further study in humans. A recent study in Ghanaians at high risk for aflatoxicosis has indicated that NS (at a dose level of 0.25%) is effective in decreasing biomarkers of aflatoxin exposure and does not interfere with the levels of serum vitamins A and E, and iron and zinc. In summary, enterosorption strategies/therapies based on NS clay are promising for the management of aflatoxins and as a sustainable public health intervention. The NS clay remedy is novel, inexpensive and easily disseminated. Based on the present research, aflatoxin sequestering clays should be rigorously evaluated in vitro and in vivo, and should meet the following criteria: (1) favourable thermodynamic characteristics of mycotoxin sorption, (2) tolerable levels of priority metals, dioxins/furans and other hazardous contaminants, (3) safety and efficacy in multiple animal species, (4) safety and efficacy in long-term studies, and (5) negligible interactions with vitamins, iron and zinc and other micronutrients.

  10. HExpoChem: a systems biology resource to explore human exposure to chemicals

    DEFF Research Database (Denmark)

    Taboureau, Olivier; Jacobsen, Ulrik Plesner; Kalhauge, Christian Gram

    2013-01-01

    of computational biology approaches are needed to assess the health risks of chemical exposure. Here we present HExpoChem, a tool based on environmental chemicals and their bioactivities on human proteins with the objective of aiding the qualitative exploration of human exposure to chemicals. The chemical......Summary: Humans are exposed to diverse hazardous chemicals daily. Although an exposure to these chemicals is suspected to have adverse effects on human health, mechanistic insights into how they interact with the human body are still limited. Therefore, acquisition of curated data and development......–protein interactions have been enriched with a quality-scored human protein–protein interaction network, a protein–protein association network and a chemical–chemical interaction network, thus allowing the study of environmental chemicals through formation of protein complexes and phenotypic outcomes enrichment...

  11. Developing a Salivary Antibody Multiplex Immunoassay to Measure Human Exposure to Environmental Pathogens

    Science.gov (United States)

    The etiology and impacts of human exposure to environmental pathogens are of major concern worldwide and, thus, the ability to assess exposure and infections using cost effective, high-throughput approaches would be indispensable. The principal objective of this work is to devel...

  12. Probabilistic estimation of residential air exchange rates for population-based human exposure modeling

    Science.gov (United States)

    Residential air exchange rates (AERs) are a key determinant in the infiltration of ambient air pollution indoors. Population-based human exposure models using probabilistic approaches to estimate personal exposure to air pollutants have relied on input distributions from AER meas...

  13. Developmental and reproductive outcomes in humans and animals after glyphosate exposure: a critical analysis.

    Science.gov (United States)

    Williams, Amy Lavin; Watson, Rebecca E; DeSesso, John M

    2012-01-01

    Glyphosate is the active ingredient of several widely used herbicide formulations. Glyphosate targets the shikimate metabolic pathway, which is found in plants but not in animals. Despite the relative safety of glyphosate, various adverse developmental and reproductive problems have been alleged as a result of exposure in humans and animals. To assess the developmental and reproductive safety of glyphosate, an analysis of the available literature was conducted. Epidemiological and animal reports, as well as studies on mechanisms of action related to possible developmental and reproductive effects of glyphosate, were reviewed. An evaluation of this database found no consistent effects of glyphosate exposure on reproductive health or the developing offspring. Furthermore, no plausible mechanisms of action for such effects were elucidated. Although toxicity was observed in studies that used glyphosate-based formulations, the data strongly suggest that such effects were due to surfactants present in the formulations and not the direct result of glyphosate exposure. To estimate potential human exposure concentrations to glyphosate as a result of working directly with the herbicide, available biomonitoring data were examined. These data demonstrated extremely low human exposures as a result of normal application practices. Furthermore, the estimated exposure concentrations in humans are >500-fold less than the oral reference dose for glyphosate of 2 mg/kg/d set by the U.S. Environmental Protection Agency (U.S. EPA 1993). In conclusion, the available literature shows no solid evidence linking glyphosate exposure to adverse developmental or reproductive effects at environmentally realistic exposure concentrations.

  14. Probabilistic acute dietary exposure assessments to captan and tolylfluanid using several European food consumption and pesticide concentration databases

    DEFF Research Database (Denmark)

    Boon, Polly E.; Svensson, Kettil; Moussavian, Shahnaz

    2009-01-01

    Probabilistic dietary acute exposure assessments of captan and tolylfluanid were performed for the populations of the Czech Republic, Denmark, Italy, the Netherlands and Sweden. The basis for these assessments was national databases for food consumption and pesticide concentration data harmonised...... at the level of raw agricultural commodity. Data were obtained from national food consumption surveys and national monitoring programmes and organised in an electronic platform of databases connected to probabilistic software. The exposure assessments were conducted by linking national food consumption data...... to national food consumption surveys. In this way it is possible to exchange or merge concentration data between countries in situations of data scarcity. This electronic platform in connection with probabilistic software can be seen as a prototype of a data warehouse, including a harmonised approach...

  15. MODELING ENERGY EXPENDITURE AND OXYGEN CONSUMPTION IN HUMAN EXPOSURE MODELS: ACCOUNTING FOR FATIGUE AND EPOC

    Science.gov (United States)

    Human exposure and dose models often require a quantification of oxygen consumption for a simulated individual. Oxygen consumption is dependent on the modeled Individual's physical activity level as described in an activity diary. Activity level is quantified via standardized val...

  16. Exposure to perfluorinated compounds and human semen quality in arctic and European populations

    DEFF Research Database (Denmark)

    Toft, Gunnar; Jönsson, B A G; Lindh, C H

    2012-01-01

    Perfluorinated compounds (PFCs) have been suspected to adversely affect human reproductive health. The aim of this study was to investigate the associations between PFC exposure and male semen quality....

  17. In vivo plasma concentration for lindane after 6 hour exposure in human skin

    Data.gov (United States)

    U.S. Environmental Protection Agency — Dataset is a time course description of lindane disappearance in blood plasma after dermal exposure in human volunteers. This dataset is associated with the...

  18. MODELING ENERGY EXPENDITURE AND OXYGEN CONSUMPTION IN HUMAN EXPOSURE MODELS: ACCOUNTING FOR FATIGUE AND EPOC

    Science.gov (United States)

    Human exposure and dose models often require a quantification of oxygen consumption for a simulated individual. Oxygen consumption is dependent on the modeled Individual's physical activity level as described in an activity diary. Activity level is quantified via standardized val...

  19. A SIMPLE COLORIMETRIC METHOD TO DETECT BIOLOGICAL EVIDENCE OF HUMAN EXPOSURE TO MICROCYSTINS

    Science.gov (United States)

    Toxic cyanobacteria are contaminants of surface waters worldwide. Microcystins are some of the most commonly detected toxins. Biological evidence of human exposure may be difficult to obtain due to limitations associated with cost, laboratory capacity, analytic support, and exp...

  20. Human Health Effects Associated with Exposure to Cyanobacteria and Cyanotoxins: What Do We Know?

    Science.gov (United States)

    The study of environmental health typically focuses on human populations. However, companion animals, livestock and wildlife also experience adverse health effects from environmental pollutants. Animals may experience direct exposure to pollutants unlike people in most ambient ex...

  1. Quantification of optic disc edema during exposure to high altitude shows no correlation to acute mountain sickness.

    Directory of Open Access Journals (Sweden)

    Gabriel Willmann

    Full Text Available BACKGROUND: The study aimed to quantify changes of the optic nerve head (ONH during exposure to high altitude and to assess a correlation with acute mountain sickness (AMS. This work is related to the Tuebingen High Altitude Ophthalmology (THAO study. METHODOLOGY/PRINCIPAL FINDINGS: A confocal scanning laser ophthalmoscope (cSLO, Heidelberg Retina Tomograph, HRT3® was used to quantify changes at the ONH in 18 healthy participants before, during and after rapid ascent to high altitude (4559 m. Slitlamp biomicroscopy was used for clinical optic disc evaluation; AMS was assessed with Lake Louise (LL and AMS-cerebral (AMS-c scores; oxygen saturation (SpO₂ and heart rate (HR were monitored. These parameters were used to correlate with changes at the ONH. After the first night spent at high altitude, incidence of AMS was 55% and presence of clinical optic disc edema (ODE 79%. Key stereometric parameters of the HRT3® used to describe ODE (mean retinal nerve fiber layer [RNFL] thickness, RNFL cross sectional area, optic disc rim volume and maximum contour elevation changed significantly at high altitude compared to baseline (p<0.05 and were consistent with clinically described ODE. All changes were reversible in all participants after descent. There was no significant correlation between parameters of ODE and AMS, SpO₂ or HR. CONCLUSIONS/SIGNIFICANCE: Exposure to high altitude leads to reversible ODE in the majority of healthy subjects. However, these changes did not correlate with AMS or basic physiologic parameters such as SpO₂ and HR. For the first time, a quantitative approach has been used to assess these changes during acute, non-acclimatized high altitude exposure. In conclusion, ODE presents a reaction of the body to high altitude exposure unrelated to AMS.

  2. Quantification of Optic Disc Edema during Exposure to High Altitude Shows No Correlation to Acute Mountain Sickness

    Science.gov (United States)

    Willmann, Gabriel; Fischer, M. Dominik; Schatz, Andreas; Schommer, Kai; Messias, Andre; Zrenner, Eberhart; Bartz-Schmidt, Karl U.; Gekeler, Florian

    2011-01-01

    Background The study aimed to quantify changes of the optic nerve head (ONH) during exposure to high altitude and to assess a correlation with acute mountain sickness (AMS). This work is related to the Tuebingen High Altitude Ophthalmology (THAO) study. Methodology/Principal Findings A confocal scanning laser ophthalmoscope (cSLO, Heidelberg Retina Tomograph, HRT3®) was used to quantify changes at the ONH in 18 healthy participants before, during and after rapid ascent to high altitude (4559 m). Slitlamp biomicroscopy was used for clinical optic disc evaluation; AMS was assessed with Lake Louise (LL) and AMS-cerebral (AMS-c) scores; oxygen saturation (SpO2) and heart rate (HR) were monitored. These parameters were used to correlate with changes at the ONH. After the first night spent at high altitude, incidence of AMS was 55% and presence of clinical optic disc edema (ODE) 79%. Key stereometric parameters of the HRT3® used to describe ODE (mean retinal nerve fiber layer [RNFL] thickness, RNFL cross sectional area, optic disc rim volume and maximum contour elevation) changed significantly at high altitude compared to baseline (p<0.05) and were consistent with clinically described ODE. All changes were reversible in all participants after descent. There was no significant correlation between parameters of ODE and AMS, SpO2 or HR. Conclusions/Significance Exposure to high altitude leads to reversible ODE in the majority of healthy subjects. However, these changes did not correlate with AMS or basic physiologic parameters such as SpO2 and HR. For the first time, a quantitative approach has been used to assess these changes during acute, non-acclimatized high altitude exposure. In conclusion, ODE presents a reaction of the body to high altitude exposure unrelated to AMS. PMID:22069483

  3. Probabilistic acute risk assessment of cumulative exposure to organophosphorus and carbamate pesticides from dietary vegetables and fruits in Shanghai populations.

    Science.gov (United States)

    Li, Fan; Yuan, Yaqun; Meng, Pai; Wu, Min; Li, Shuguang; Chen, Bo

    2017-05-01

    Organophosphorus pesticides (OPs) and carbamate pesticides (CPs) are among the most widely used pesticides in China, playing a major role in protecting agricultural commodities. In this study, we determined the cumulative acute exposure to OPs and CPs of Shanghai residents from vegetables and fruits (VFs). The food consumption data were obtained from the Shanghai Food Consumption Survey (SHFCS) of 2012-14 including a total of 1973 participants aged 2-90 years. The pesticide residue data were obtained from the Shanghai monitoring programme during 2008-11 with 34 organophosphates and 11 carbamates analysed in a total of 5335 samples of VFs. A probabilistic approach was performed as recommended by the EFSA, using the optimistic model with non-detects set as zero and with processing factors (PFs) being used and the pessimistic model with non-detects replaced by limit of detection (LOD) and without PFs. We used the relative potency factor (RPF) method to normalise the various pesticides to the index compound (IC) of methamidophos and chlorpyrifos separately. Only in the pessimistic model using methamidophos as the IC was there was small risk of exposure exceeding the ARfD (3 µg kg(-)(1) bw day(-)(1)) in the populations of preschool children (0.029%), school-age children (0.022%) and adults (0.002%). There were no risk of exposure exceeding the ARfD of methamidophos in the optimistic model and of chlorpyrifos (100 µg kg(-)(1) bw day(-)(1)) in both optimistic and pessimistic models in all three populations. Considering the Chinese habits of overwhelmingly eating processed food (vegetables being cooked, and fruits being washed or peeled), we conclude that little acute risk was found for the exposure to VF-sourced OPs and CPs in Shanghai.

  4. Hemolytic uremic syndrome as a primary manifestation of acute human immunodeficiency virus infection.

    Science.gov (United States)

    Gomes, A M; Ventura, A; Almeida, C; Correia, M; Tavares, V; Mota, M; Seabra, J

    2009-05-01

    Hemolytic uremic syndrome may be associated with human immunodeficiency virus infection but it occurs in advanced stages of human immunodeficiency virus disease. As in other forms of hemolytic uremic syndrome plasmapheresis seems to be the treatment of choice. The authors present an unusual case of hemolytic uremic syndrome associated with acute human immunodeficiency virus infection in a 38 year-old black male. The patient was admitted with fever, asthenia, nausea, diarrhea, and reduced urinary output. He was found to have anemia, thrombocytopenia and severe renal failure. Hemolytic uremic syndrome was diagnosed and he was started on plasmapheresis and hemodialysis. Serological tests were consistent with acute human immunodeficiency virus infection: the enzyme linked immunosorbent assay for human immunodeficiency virus was weakly positive, Western Blot test was negative and human immunodeficiency virus RNA quantification was positive, with > 1,000,000 copies/microl. After 4 daily treatment sessions, patient's clinical condition improved and hemoglobin, platelets, lactic dehydrogenase and renal function normalized.

  5. Cross-host evolution of severe acute respiratory syndrome coronavirus in palm civet and human

    Science.gov (United States)

    Song, Huai-Dong; Tu, Chang-Chun; Zhang, Guo-Wei; Wang, Sheng-Yue; Zheng, Kui; Lei, Lian-Cheng; Chen, Qiu-Xia; Gao, Yu-Wei; Zhou, Hui-Qiong; Xiang, Hua; Zheng, Hua-Jun; Chern, Shur-Wern Wang; Cheng, Feng; Pan, Chun-Ming; Xuan, Hua; Chen, Sai-Juan; Luo, Hui-Ming; Zhou, Duan-Hua; Liu, Yu-Fei; He, Jian-Feng; Qin, Peng-Zhe; Li, Ling-Hui; Ren, Yu-Qi; Liang, Wen-Jia; Yu, Ye-Dong; Anderson, Larry; Wang, Ming; Xu, Rui-Heng; Wu, Xin-Wei; Zheng, Huan-Ying; Chen, Jin-Ding; Liang, Guodong; Gao, Yang; Liao, Ming; Fang, Ling; Jiang, Li-Yun; Li, Hui; Chen, Fang; Di, Biao; He, Li-Juan; Lin, Jin-Yan; Tong, Suxiang; Kong, Xiangang; Du, Lin; Hao, Pei; Tang, Hua; Bernini, Andrea; Yu, Xiao-Jing; Spiga, Ottavia; Guo, Zong-Ming; Pan, Hai-Yan; He, Wei-Zhong; Manuguerra, Jean-Claude; Fontanet, Arnaud; Danchin, Antoine; Niccolai, Neri; Li, Yi-Xue; Wu, Chung-I; Zhao, Guo-Ping

    2005-01-01

    The genomic sequences of severe acute respiratory syndrome coronaviruses from human and palm civet of the 2003/2004 outbreak in the city of Guangzhou, China, were nearly identical. Phylogenetic analysis suggested an independent viral invasion from animal to human in this new episode. Combining all existing data but excluding singletons, we identified 202 single-nucleotide variations. Among them, 17 are polymorphic in palm civets only. The ratio of nonsynonymous/synonymous nucleotide substitution in palm civets collected 1 yr apart from different geographic locations is very high, suggesting a rapid evolving process of viral proteins in civet as well, much like their adaptation in the human host in the early 2002–2003 epidemic. Major genetic variations in some critical genes, particularly the Spike gene, seemed essential for the transition from animal-to-human transmission to human-to-human transmission, which eventually caused the first severe acute respiratory syndrome outbreak of 2002/2003. PMID:15695582

  6. Effects of gabapentin in acute inflammatory pain in humans

    DEFF Research Database (Denmark)

    Werner, M U; Perkins, F M; Holte, Kathrine;

    2001-01-01

    BACKGROUND AND OBJECTIVES: The aim of the study was to examine the analgesic effects of the anticonvulsant, gabapentin, in a validated model of acute inflammatory pain. METHODS: Twenty-two volunteers were investigated in a double-blind, randomized, placebo-controlled cross-over study. Gabapentin 1...... not significantly changed by gabapentin (P study indicates that gabapentin has no analgesic effect in normal skin, but may reduce primary mechanical allodynia in acute......,200 mg or placebo was given on 2 separate study days. Three hours after drug administration, a first-degree burn injury was produced on the medial aspect of the nondominant calf (12.5 cm(2), 47 degrees C for 7 minutes). Quantitative sensory testing (QST) included pain ratings to thermal and mechanical...

  7. Human Bronchial Epithelial Cell Response to Heavy Particle Exposure

    Science.gov (United States)

    Story, Michael; Ding, Liang-Hao; Minna, John; Park, Seong-mi; Peyton, Michael; Larsen, Jill

    2012-07-01

    A battery of non-oncogenically immortalized human bronchial epithelial cells (HBECs) are being used to examine the molecular changes that lead to lung carcinogenesis after exposure to heavy particles found in the free space environment. The goal is to ultimately identify biomarkers of radioresponse that can be used for prediction of carcinogenic risk for fatal lung cancer. Our initial studies have focused on the cell line HBEC3 KT and the isogenic variant HBEC3 KTR53, which overexpresses the RASv12 mutant and where p53 has been knocked down by shRNA, and is considered to be a more oncogenically progressed variant. We have previously described the response of HBEC3 KT at the cellular and molecular level, however, the focus here is on the rate of cellular transformation after HZE radiation exposure and the molecular changes in transformed cells. When comparing the two cell lines we find that there is a maximum rate of cellular transformation at 0.25 Gy when cells are exposed to 1 GeV Fe particles, and, for the HBEC3 KTR53 there are multiple pathways upregulated that promote anchorage independent growth including the mTOR pathway, the TGF-1 pathway, RhoA signaling and the ERK/MAPK pathway as early as 2 weeks after radiation. This does not occur in the HBEC3 KT cell line. Transformed HBEC3 KT cells do not show any morphologic or phenotypic changes when grown as cell cultures. HBEC3 KTR53 cells on the other hand show substantial changes in morphology from a cobblestone epithelial appearance to a mesenchymal appearance with a lack of contact inhibition. This epithelial to mesenchymal change in morphology is accompanied by the expression of vimentin and a reduction in the expression of E-cadherin, which are hallmarks of epithelial to mesenchymal transition. Interestingly, for HBEC3 KT transformed cells there are no mutations in the p53 gene, 2 of 15 clones were found to be heterozygous for the RASV12 mutation, and 3 of 15 clones expressed high levels of BigH3, a TGFB

  8. Electrocardiographic, hemodynamic, and biochemical responses to acute particulate matter (PM) exposure in aged heart failure-prone rats

    Science.gov (United States)

    Human exposure to ambient PM from fossil-fuel emissions is linked to cardiovascular disease and death. This association strengthens in people with preexisting cardiac disease-especially heart failure (HF). The mechanisms explaining PM-induced exacerbation ofHF are unclear. Some o...

  9. Acute Exposure to Particulate Matter (PM) Alters Physiologic and Toxicologic Endpoints in a Rat Model of Heart Failure

    Science.gov (United States)

    Human exposure to ambient PM from fossil-fuel emissions is linked to cardiovascular disease and death. This association strengthens in people with preexisting cardiopulmonary diseases—especially heart failure (HF). We previously examined the effects of PM on HF by exposing Sponta...

  10. Environmental levels, toxicity and human exposure to tributyltin (TBT)-contaminated marine environment. a review. b_antizar@hotmail.com.

    Science.gov (United States)

    Antizar-Ladislao, Blanca

    2008-02-01

    Tributyltin (TBT) is a toxic chemical used for various industrial purposes such as slime control in paper mills, disinfection of circulating industrial cooling waters, antifouling agents, and the preservation of wood. Due to its widespread use as an antifouling agent in boat paints, TBT is a common contaminant of marine and freshwater ecosystems exceeding acute and chronic toxicity levels. TBT is the most significant pesticide in marine and freshwaters in Europe and consequently its environmental level, fate, toxicity and human exposure are of current concern. Thus, the European Union has decided to specifically include TBT compounds in its list of priority compounds in water in order to control its fate in natural systems, due to their toxic, persistent, bioaccumulative and endocrine disruptive characteristics. Additionally, the International Maritime Organization has called for a global treaty that bans the application of TBT-based paints starting 1 of January 2003, and total prohibition by 1 of January 2008. This paper reviews the state of the science regarding TBT, with special attention paid to the environmental levels, toxicity, and human exposure. TBT compounds have been detected in a number of environmental samples. In humans, organotin compounds have been detected in blood and in the liver. As for other persistent organic pollutants, dietary intake is most probably the main route of exposure to TBT compounds for the general population. However, data concerning TBT levels in foodstuffs are scarce. It is concluded that investigations on experimental toxicity, dietary intake, potential human health effects and development of new sustainable technologies to remove TBT compounds are clearly necessary.

  11. The human placenta--an alternative for studying foetal exposure

    DEFF Research Database (Denmark)

    Myren, Maja; Mose, Tina; Mathiesen, Line;

    2007-01-01

    , and though its main task is to act as a barrier and transport nutrients and oxygen to the foetus, many foreign compounds are transported across the placenta to some degree and may therefore influence the unborn child. Foetal exposures to environmental and medicinal products may have impact on the growth...

  12. GLI3 Links Environmental Arsenic Exposure and Human Fetal Growth

    Directory of Open Access Journals (Sweden)

    Emily F. Winterbottom

    2015-06-01

    Full Text Available Although considerable evidence suggests that in utero arsenic exposure affects children's health, these data are mainly from areas of the world where groundwater arsenic levels far exceed the World Health Organization limit of 10 μg/L. We, and others, have found that more common levels of in utero arsenic exposure may also impact children's health. However, the underlying molecular mechanisms are poorly understood. To address this issue, we analyzed the expression of key developmental genes in fetal placenta in a birth cohort of women using unregulated water supplies in a US region with elevated groundwater arsenic. We identified several genes whose expression associated with maternal arsenic exposure in a fetal sex-specific manner. In particular, expression of the HEDGEHOG pathway component, GLI3, in female placentae was both negatively associated with arsenic exposure and positively associated with infant birth weight. This suggests that modulation of GLI3 in the fetal placenta, and perhaps in other fetal tissues, contributes to arsenic's detrimental effects on fetal growth. We showed previously that arsenic-exposed NIH3T3 cells have reduced GLI3 repressor protein. Together, these studies identify GLI3 as a key signaling node that is affected by arsenic, mediating a subset of its effects on developmental signaling and fetal health.

  13. 18. Adduct detection in human monitoring for carcinogen exposure

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Determination of the covalently bound products (adducts) of carcinogens with DNA or proteins may be used for the monitoring of exposure to these compounds. Protein adducts are generally stable and are not enzymatically repaired, and the use of these for cxposure monitoring is normally carried out with globin or albumin, because

  14. GLI3 Links Environmental Arsenic Exposure and Human Fetal Growth.

    Science.gov (United States)

    Winterbottom, Emily F; Fei, Dennis L; Koestler, Devin C; Giambelli, Camilla; Wika, Eric; Capobianco, Anthony J; Lee, Ethan; Marsit, Carmen J; Karagas, Margaret R; Robbins, David J

    2015-06-01

    Although considerable evidence suggests that in utero arsenic exposure affects children's health, these data are mainly from areas of the world where groundwater arsenic levels far exceed the World Health Organization limit of 10 μg/L. We, and others, have found that more common levels of in utero arsenic exposure may also impact children's health. However, the underlying molecular mechanisms are poorly understood. To address this issue, we analyzed the expression of key developmental genes in fetal placenta in a birth cohort of women using unregulated water supplies in a US region with elevated groundwater arsenic. We identified several genes whose expression associated with maternal arsenic exposure in a fetal sex-specific manner. In particular, expression of the HEDGEHOG pathway component, GLI3, in female placentae was both negatively associated with arsenic exposure and positively associated with infant birth weight. This suggests that modulation of GLI3 in the fetal placenta, and perhaps in other fetal tissues, contributes to arsenic's detrimental effects on fetal growth. We showed previously that arsenic-exposed NIH3T3 cells have reduced GLI3 repressor protein. Together, these studies identify GLI3 as a key signaling node that is affected by arsenic, mediating a subset of its effects on developmental signaling and fetal health.

  15. Acute and chronic effects from pulse exposure of D. magna to silver and copper oxide nanoparticles

    DEFF Research Database (Denmark)

    Sørensen, Sara Nørgaard; Lützhøft, Hans-Christian Holten; Rasmussen, Rose

    2016-01-01

    Aquatic toxicity testing of nanoparticles (NPs) is challenged by their dynamic behavior in test suspensions. The resulting difficulties in controlling and characterizing exposure concentrations are detrimental to the generation of concentration-response data needed for hazard identification of NPs...... concentrations during 1–3 h pulses than for 24–48 h continuous exposures. For AgNPs, preparation of test suspensions in medium 24 h before toxicity testing (aging) increased stability during the short-term pulses. In pulse tests, organisms were exposed to the test materials, AgNPs and CuONPs for 1, 2 and 3 h...... (observed after 48 h post-exposure) as 24 h continuous exposure, as evidenced by overlapping 95% confidence intervals of EC50-values. In the 21 d post-exposure period, no trends in mortality or body length were identified. AgNP and AgNO3 pulses had no effect on the number of moltings, days to first live...

  16. Moderate (2%, v/v Ethanol Feeding Alters Hepatic Wound Healing after Acute Carbon Tetrachloride Exposure in Mice

    Directory of Open Access Journals (Sweden)

    Krutika T. Deshpande

    2016-01-01

    Full Text Available Wound healing consists of three overlapping phases: inflammation, proliferation, and matrix synthesis and remodeling. Prolonged alcohol abuse can cause liver fibrosis due to deregulated matrix remodeling. Previous studies demonstrated that moderate ethanol feeding enhances liver fibrogenic markers and frank fibrosis independent of differences in CCl4-induced liver injury. Our objective was to determine whether or not other phases of the hepatic wound healing response were affected by moderate ethanol after CCl4 exposure. Mice were fed moderate ethanol (2% v/v for two days and then were exposed to CCl4 and euthanized 24–96 h later. Liver injury was not different between pair- and ethanol-fed mice; however, removal of necrotic tissue was delayed after CCl4-induced liver injury in ethanol-fed mice. Inflammation, measured by TNFα mRNA and protein and hepatic Ly6c transcript accumulation, was reduced and associated with enhanced hepatocyte apoptosis after ethanol feeding. Hepatocytes entered the cell cycle equivalently in pair- and ethanol-fed mice after CCl4 exposure, but hepatocyte proliferation was prolonged in livers from ethanol-fed mice. CCl4-induced hepatic stellate cell activation was increased and matrix remodeling was prolonged in ethanol-fed mice compared to controls. Taken together, moderate ethanol affected each phase of the wound healing response to CCl4. These data highlight previously unknown effects of moderate ethanol exposure on hepatic wound healing after acute hepatotoxicant exposure.

  17. Moderate (2%, v/v) Ethanol Feeding Alters Hepatic Wound Healing after Acute Carbon Tetrachloride Exposure in Mice.

    Science.gov (United States)

    Deshpande, Krutika T; Liu, Shinlan; McCracken, Jennifer M; Jiang, Lu; Gaw, Ta Ehpaw; Kaydo, Lindsey N; Richard, Zachary C; O'Neil, Maura F; Pritchard, Michele T

    2016-01-06

    Wound healing consists of three overlapping phases: inflammation, proliferation, and matrix synthesis and remodeling. Prolonged alcohol abuse can cause liver fibrosis due to deregulated matrix remodeling. Previous studies demonstrated that moderate ethanol feeding enhances liver fibrogenic markers and frank fibrosis independent of differences in CCl₄-induced liver injury. Our objective was to determine whether or not other phases of the hepatic wound healing response were affected by moderate ethanol after CCl₄ exposure. Mice were fed moderate ethanol (2% v/v) for two days and then were exposed to CCl₄ and euthanized 24-96 h later. Liver injury was not different between pair- and ethanol-fed mice; however, removal of necrotic tissue was delayed after CCl₄-induced liver injury in ethanol-fed mice. Inflammation, measured by TNFα mRNA and protein and hepatic Ly6c transcript accumulation, was reduced and associated with enhanced hepatocyte apoptosis after ethanol feeding. Hepatocytes entered the cell cycle equivalently in pair- and ethanol-fed mice after CCl₄ exposure, but hepatocyte proliferation was prolonged in livers from ethanol-fed mice. CCl₄-induced hepatic stellate cell activation was increased and matrix remodeling was prolonged in ethanol-fed mice compared to controls. Taken together, moderate ethanol affected each phase of the wound healing response to CCl₄. These data highlight previously unknown effects of moderate ethanol exposure on hepatic wound healing after acute hepatotoxicant exposure.

  18. Contributing Factors for Acute Illness/Injury from Childhood Pesticide Exposure in North Carolina, USA, 2007–2013

    Directory of Open Access Journals (Sweden)

    Nirmalla Barros

    2016-02-01

    Full Text Available Between 2007 and 2013, there were 685 events with evidence of a relationship between pesticide exposure and acute illness/injury among persons less than 18 years old in North Carolina (United States. Median age of children affected was 4.3 years (range: 0.2–17.9. Distribution by gender was similar across all age groups. One fatality and four high severity events were observed. The greatest proportion (42% of events had ocular exposures, followed by dermal (25% and inhalation (18% exposures. When more than one route of exposure occurred, dermal and ocular routes were the most common (46%. Almost all events took place indoors and 32 events involved contact with pets. Insecticides (53% and insect repellants (31% were the most frequent agents contributing to these events. Manual application of pesticides contributed to the greatest number of events (25%, while application through a pressurized can and use of a trigger pump were involved in 21% and 15% of events, respectively. Additional contributors were due to inappropriate storage of pesticides and improper use of the pesticide. These contributing factors can be removed or minimized if pesticides are stored outside the residence or out of the reach of children and pets, and adequate ventilation is ensured whenever pesticides are applied.

  19. Probabilistic acute dietary exposure assessments to captan and tolylfluanid using several European food consumption and pesticide concentration databases.

    Science.gov (United States)

    Boon, Polly E; Svensson, Kettil; Moussavian, Shahnaz; van der Voet, Hilko; Petersen, Annette; Ruprich, Jiri; Debegnach, Francesca; de Boer, Waldo J; van Donkersgoed, Gerda; Brera, Carlo; van Klaveren, Jacob D; Busk, Leif

    2009-12-01

    Probabilistic dietary acute exposure assessments of captan and tolylfluanid were performed for the populations of the Czech Republic, Denmark, Italy, the Netherlands and Sweden. The basis for these assessments was national databases for food consumption and pesticide concentration data harmonised at the level of raw agricultural commodity. Data were obtained from national food consumption surveys and national monitoring programmes and organised in an electronic platform of databases connected to probabilistic software. The exposure assessments were conducted by linking national food consumption data either (1) to national pesticide concentration data or (2) to a pooled database containing all national pesticide concentration data. We show that with this tool national exposure assessments can be performed in a harmonised way and that pesticide concentrations of other countries can be linked to national food consumption surveys. In this way it is possible to exchange or merge concentration data between countries in situations of data scarcity. This electronic platform in connection with probabilistic software can be seen as a prototype of a data warehouse, including a harmonised approach for dietary exposure modelling.

  20. Enhanced biosynthesis of quercetin occurs as A photoprotective measure in Lycopersicon esculentum mill. under Acute UV-B exposure

    Directory of Open Access Journals (Sweden)

    Abhilasha Shourie

    2014-06-01

    Full Text Available Lycopersicon esculentum respond to UV-B by enhanced synthesis of flavonoid quercetin, a strong antioxidant that helps the plants to well acclimatize to UV-B stress. Three weeks old plants of L. esculentum were subjected to acute UV-B irradiation for 20, 40 and 60 minutes daily until 28 days and analyzed for the morphological and biochemical changes. UV-B exposure for 40 and 60 minutes considerably affected the growth and biomass of L. esculentum. The leaves were deformed, developed chlorosis and abscised early as compared to the unexposed plants. Biomass declined by 35% and total chlorophyll decreased by 24.7% due to disintegration of chloroplasts. Enhancement was seen in the content of carotenoids, anthocyanins and total flavonoids by 15, 33.3 and 22.8%, respectively, which was attributed to the photoprotective role of these compounds as potential quenchers of excess excitation energy. Quercetin content decreased on UV-B exposure to 20 and 40 min, and thereafter increased significantly by 5.19% on 60 min of exposure. This pattern probably indicated that the over-expression of genes involved in its biosynthesis such as phenylalanine ammonia lyase (PAL, chalcone synthase (CHS, flavanone 3-hydroxylase (F3H and dihydroflavonol 4-reductase (DFR occurred only after certain threshold exposure (60 min, which could be the strategy for developing tolerance against UV-B stress in L. esculentum.

  1. Influence of acclimation and exposure temperature on the acute toxicity of cadmium to the freshwater snail Potamopyrgus antipodarum (Hydrobiidae)

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, V.; Forbes, V.E.; Depledge, M.H. (Odense Univ. (Denmark). Ecotoxicology Group)

    1994-09-01

    Forty-eight-hour acute toxicity tests were performed to determine the influence of acclimation temperature (5, 15, and 20 C) and exposure temperature (5, 15, and 20 C) on the toxicity of cadmium to the freshwater gastropod Potamopyrgus antipodarum. Mortality varied with cadmium concentration and treatment conditions, but did not conform to conventional sigmoid concentration-response relationships. Because the shapes of the concentration-response curves were treatment dependent, a nontraditional approach for data analysis was employed. Regardless of acclimation temperature, mortality increased with increasing exposure temperature, and at all exposure temperatures snails acclimated at 15 C were most susceptible to cadmium toxicity. Estimated LC50 values were within 1 to 4 mg Cd/L. Although the shapes of the concentration-response curves were different for each treatment, the slopes were generally quite steep, indicating a uniform response for the whole population. At a given Cd concentration, acclimation temperature and exposure temperature accounted for 57 and 40%, respectively, of the variation in mortality, and LC50s changed by a factor of four. The results indicate that changes in environmental variables can alter both the degree of response and the response distribution of a population, and that past as well as prevailing environmental conditions can influence organismic responses to toxicants.

  2. Opposite effects of acute ethanol exposure on GAP-43 and BDNF expression in the hippocampus versus the cerebellum of juvenile rats.

    Science.gov (United States)

    Kulkarny, V V; Wiest, N E; Marquez, C P; Nixon, S C; Valenzuela, C F; Perrone-Bizzozero, N I

    2011-08-01

    The adolescent brain is particularly vulnerable to the effects of alcohol, with intoxications at this developmental age often producing long-lasting effects. The present study addresses the effects of a single acute ethanol exposure on growth-associated protein-43 (GAP-43) and brain-derived neurotrophic factor (BDNF) gene expression in neurons in the cerebellum and hippocampus of adolescent rats. Male postnatal day 23 (P23) Sprague-Dawley rats were exposed to ethanol vapors for 2h and after a recovery period of 2h, the cerebellum and hippocampus were harvested and samples were taken for blood alcohol concentration (BAC) determinations. We found that this exposure resulted in a mean BAC of 174 mg/dL, which resembles levels in human adolescents after binge drinking. Analyses of total RNA and protein by quantitative reverse transcription PCR and western blotting, respectively, revealed that this single ethanol exposure significantly decreased the levels of GAP-43 mRNA and protein in the cerebellum but increased the levels of mRNA and protein in the hippocampus. BDNF mRNA and protein levels were also increased in the hippocampus but not in the cerebellum of these animals. In situ hybridizations revealed that GAP-43 and BDNF mRNA levels were primarily increased by alcohol exposure in hippocampal dentate granule cells and CA3 neurons. Overall, the reported alterations in the expression of the plasticity-associated genes GAP-43 and BDNF in juvenile rats are consistent with the known deleterious effects of binge drinking on motor coordination and cognitive function.

  3. A systematic review of the human body burden of e-waste exposure in China.

    Science.gov (United States)

    Song, Qingbin; Li, Jinhui

    2014-07-01

    As China is one of the countries facing the most serious pollution and human exposure effects of e-waste in the world, much of the population there is exposed to potentially hazardous substances due to informal e-waste recycling processes. This report reviews recent studies on human exposure to e-waste in China, with particular focus on exposure routes (e.g. dietary intake, inhalation, and soil/dust ingestion) and human body burden markers (e.g. placenta, umbilical cord blood, breast milk, blood, hair, and urine) and assesses the evidence for the association between such e-waste exposure and the human body burden in China. The results suggest that residents in the e-waste exposure areas, located mainly in the three traditional e-waste recycling sites (Taizhou, Guiyu, and Qingyuan), are faced with a potential higher daily intake of these pollutants than residents in the control areas, especially via food ingestion. Moreover, pollutants (PBBs, PBDEs, PCBs, PCDD/Fs, and heavy metals) from the e-waste recycling processes were all detectable in the tissue samples at high levels, showing that they had entered residents' bodies through the environment and dietary exposure. Children and neonates are the groups most sensitive to the human body effects of e-waste exposure. We also recorded plausible outcomes associated with exposure to e-waste, including 7 types of human body burden. Although the data suggest that exposure to e-waste is harmful to health, better designed epidemiological investigations in vulnerable populations, especially neonates and children, are needed to confirm these associations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Additional human exposure information for gasoline substance risk assessment (period 2002-2007)

    Energy Technology Data Exchange (ETDEWEB)

    Bomer, R.; Carter, M.; Dmytrasz, B.; Mulari, M.; Pizzella, G.; Roth, S.; Van de Sandt, P.

    2009-06-15

    This report provides an update on human exposure information for gasoline-related activities for which previous assessments had suggested that exposure was either elevated or highly variable or available data were considered out-of-date. In addition data are presented for several activities for which no information had been available previously. The occupational exposures activities described in this report include railcar loading, refinery maintenance, laboratory operations, aviation gasoline refuelling, gasoline pump maintenance and repair, gasoline pump calibration, and the operation of gasoline-powered gardening equipment. In addition, general public exposure levels are described, particularly relating to residency near service stations.

  5. Clinical, cardiopulmonary and haemocytological effects of xylazine in goats after acute exposure to different environmental temperature and humidity conditions

    Directory of Open Access Journals (Sweden)

    E.G.M. Mogoa

    2000-07-01

    Full Text Available This study was carried out to assess the influence of xylazine administration on clinical, cardiopulmonary and haemocytological variables after acute exposure to different environmental conditions. Xylazine hydrochloride was administered intravenously at 0.1 mg/kg body mass to 6 clinically healthy, castrated male goats. All animals were exposed for 60 min to 3 sets of climatic conditions: 14 °C, 33% relative humidity; 24 °C, 55% RH, and 34 °C, 65% RH. The variables that were measured for a period of 60 min after xylazine administration were sedation, analgesia, salivation, urination, ventilation rate, heart-rate, mean arterial blood pressure, oesophageal temperature, haematocrit, mean corpuscular volume and mean corpuscular haemoglobin concentration. Xylazine induced sedation, analgesia, salivation and urination independently of the 3 environmental conditions. Environment had no influence on the onset, duration and recovery from sedation. In the 14 °C environment, xylazine resulted in a significant decrease in ventilation and heart-rate from baseline values. Significant changes in mean arterial blood pressure, haemoglobin concentration, mean corpuscular volume, haematocrit and red cell count were observed in the 3 environments. Total plasma protein was significantly altered at 24 °C and 34 °C. Acute exposure of goats to different environmental conditions had no significant influence on the clinical, cardiopulmonary and haemocytological variables. Physiological changes induced by xylazine were therefore independent of the environment.

  6. 3T3-L1 preadipocytes exhibit heightened monocyte-chemoattractant protein-1 response to acute fatty acid exposure.

    Science.gov (United States)

    Dordevic, Aimee L; Konstantopoulos, Nicky; Cameron-Smith, David

    2014-01-01

    Preadipocytes contribute to the inflammatory responses within adipose tissue. Whilst fatty acids are known to elicit an inflammatory response within adipose tissue, the relative contribution of preadipocytes and mature adipocytes to this is yet to be determined. We aimed to examine the actions of common dietary fatty acids on the acute inflammatory and adipokine response in 3T3-L1 preadipocytes and differentiated mature adipocytes. Gene expression levels of key adipokines in 3T3-L1 preadipocytes and adipocytes were determined following incubation with palmitic acid, myristic acid or oleic acid and positive inflammatory control, lipopolysaccharide for 2 and 4 h. Inflammatory kinase signalling was assessed by analysis of nuclear factor-κB, p38-mitogen-activated protein kinase and c-jun amino-terminal kinase phosphorylation. Under basal conditions, intracellular monocyte chemoattractant protein-1 and interleukin-6 gene expression levels were increased in preadipocytes, whereas mature adipocytes expressed increased gene expression levels of leptin and adiponectin. Fatty acid exposure at 2 and 4 h increased both monocyte chemoattractant protein-1 and interleukin-6 gene expression levels in preadipocytes to greater levels than in mature adipocytes. There was an accompanying increase of inhibitor of κB-α degradation and nuclear factor-κB (p65) (Ser536) phosphorylation with fatty acid exposure in the preadipocytes only. The current study points to preadipocytes rather than the adipocytes as the contributors to both immune cell recruitment and inflammatory adipokine secretion with acute increases in fatty acids.

  7. Cellular distribution of uranium after acute exposure of renal epithelial cells: SEM, TEM and nuclear microscopy analysis

    Science.gov (United States)

    Carrière, Marie; Gouget, Barbara; Gallien, Jean-Paul; Avoscan, Laure; Gobin, Renée; Verbavatz, Jean-Marc; Khodja, Hicham

    2005-04-01

    The major health effect of uranium exposure has been reported to be chemical kidney toxicity, functional and histological damages being mainly observed in proximal tubule cells. Uranium enters the proximal tubule as uranyl-bicarbonate or uranyl-citrate complexes. The aim of our research is to investigate the mechanisms of uranium toxicity, intracellular accumulation and repartition after acute intoxication of rat renal proximal tubule epithelial cells, as a function of its chemical form. Microscopic observations of renal epithelial cells after acute exposure to uranyl-bicarbonate showing the presence of intracellular precipitates as thin needles of uranyl-phosphate localized in cell lysosomes have been published. However the initial site of precipitates formation has not been identified yet: they could either be formed outside the cells before internalization, or directly inside the cells. Uranium solubility as a function and initial concentration was specified by ICP-MS analysis of culture media. In parallel, uranium uptake and distribution in cell monolayers exposed to U-bicarbonate was investigated by nuclear microprobe analyses. Finally, the presence of uranium precipitates was tested out by scanning electron microscopic observations (SEM), while extracellular and/or intracellular precipitates were observed on thin sections of cells by transmission electron microscopy (TEM).

  8. Cellular distribution of uranium after acute exposure of renal epithelial cells: SEM, TEM and nuclear microscopy analysis

    Energy Technology Data Exchange (ETDEWEB)

    Carriere, Marie [Laboratoire Pierre Suee, CEA-CNRS UMR 9956, CEA/Saclay, 91191 Gif-sur-Yvette (France)]. E-mail: carriere@drecam.cea.fr; Gouget, Barbara [Laboratoire Pierre Suee, CEA-CNRS UMR 9956, CEA/Saclay, 91191 Gif-sur-Yvette (France); Gallien, Jean-Paul [Laboratoire Pierre Suee, CEA-CNRS UMR 9956, CEA/Saclay, 91191 Gif-sur-Yvette (France); Avoscan, Laure [Laboratoire Pierre Suee, CEA-CNRS UMR 9956, CEA/Saclay, 91191 Gif-sur-Yvette (France); Gobin, Renee [Laboratoire d' imagerie cellulaire et moleculaire, DBJC/SBFM/LTMD, CEA/Saclay, 91191 Gif sur Yvette (France); Verbavatz, Jean-Marc [Laboratoire d' imagerie cellulaire et moleculaire, DBJC/SBFM/LTMD, CEA/Saclay, 91191 Gif sur Yvette (France); Khodja, Hicham [Laboratoire Pierre Suee, CEA-CNRS UMR 9956, CEA/Saclay, 91191 Gif-sur-Yvette (France)

    2005-04-01

    The major health effect of uranium exposure has been reported to be chemical kidney toxicity, functional and histological damages being mainly observed in proximal tubule cells. Uranium enters the proximal tubule as uranyl-bicarbonate or uranyl-citrate complexes. The aim of our research is to investigate the mechanisms of uranium toxicity, intracellular accumulation and repartition after acute intoxication of rat renal proximal tubule epithelial cells, as a function of its chemical form. Microscopic observations of renal epithelial cells after acute exposure to uranyl-bicarbonate showing the presence of intracellular precipitates as thin needles of uranyl-phosphate localized in cell lysosomes have been published. However the initial site of precipitates formation has not been identified yet: they could either be formed outside the cells before internalization, or directly inside the cells. Uranium solubility as a function and initial concentration was specified by ICP-MS analysis of culture media. In parallel, uranium uptake and distribution in cell monolayers exposed to U-bicarbonate was investigated by nuclear microprobe analyses. Finally, the presence of uranium precipitates was tested out by scanning electron microscopic observations (SEM), while extracellular and/or intracellular precipitates were observed on thin sections of cells by transmission electron microscopy (TEM)

  9. Acute acidic exposure induces p53-mediated oxidative stress and DNA damage in tilapia (Oreochromis niloticus) blood cells.

    Science.gov (United States)

    Mai, Wei-jun; Yan, Jun-lun; Wang, Lei; Zheng, Ying; Xin, Yu; Wang, Wei-na

    2010-11-01

    Acid rain and inputs of acidic effluent can result in increased acidity in aquatic ecosystems, where it is known to have a significant impact and possibly, to cause the decline of some populations of aquatic organisms. In previous studies, intracellular acid-induced oxidative stress has been shown to cause DNA damage, and cooperatively activate the expression of the p53 gene. The acute effects of acidic environments on shrimp and fish have been widely studied. However, the molecular mechanism of acid-induced injury remains largely unknown. In this study, we examined the cellular responses of tilapia to acidic exposure-induced oxidative stress and antioxidant enzyme gene expression. Furthermore, we determined how acute acid stress activates the ATM-p53 signal pathway. We measured the upregulation of reactive oxygen species (ROS) production, the intracellular Ca(2)(+) concentration ([Ca(2)(+)](i)), the tail DNA values, the malondialdehyde (MDA) level in the blood cells and the percentage of dead and damaged blood cells. Our results suggest that oxidative stress and DNA damage occurred in tilapia in conditions where the pH was 5.3. Apoptosis was detected by Hoechst staining, which was mainly associated with changes in cell viability. The parameters that we measured were related to acid-induced DNA damage, and all parameters changed in the blood cells through time. The effects of acute acid exposure (pH 5.3) on the expression of ATM, p53, p21, Bax, manganese superoxide dismutase (MnSOD), glutathione peroxidase (GPx) were investigated in tilapia blood cells. The results showed that acute acid stress induced upregulation of ATM, p53 and p21, associated with increasing of DNA damage and apoptosis in blood cells. Additionally, the expression of Bax was slightly increased. Moreover, consensus p53-binding sequences were identified in tilapia MnSOD and GPx gene promoter regions and increased levels of ROS in the blood cells coincided with increased mRNA expression of p53, Mn

  10. Impact of acute kidney injury exposure period among liver transplantation patients

    Science.gov (United States)

    2013-01-01

    Background Acute kidney injury is a common complication of liver transplantation. In this single-centre retrospective observational study, we investigated the impact of acute kidney disease on liver recipient survival. Methods The study population consisted of patients who underwent a liver engraftment between January 2002 and November 2006, at a single transplantation centre in São Paulo, Brazil. Acute kidney injury diagnosis and staging were according to the recommendations of the Acute Kidney Injury Network and consisted of scanning the daily serum creatinine levels throughout the hospital stay. Patients requiring renal replacement therapy prior to transplantation, those who developed acute kidney injury before the procedure or those receiving their second liver graft were excluded from the study. Results A total of 444 liver transplantations were performed during the study period, and 129 procedures (29%) were excluded. The remaining 315 patients constituted the study population. In 207 procedures, the recipient was male (65%). The mean age of the population was 51 years. Cumulative incidence of acute kidney injury within 48 h, during the first week after transplantation, and throughout the hospital stay was 32, 81 and 93%, respectively. Renal replacement therapy was required within a week after the transplantation in 31 procedures (10%), and another 17 (5%) required replacement therapy after that period. Mean follow-up period was 2.3 years. Time in days from acute kidney injury diagnosis to initiation of replacement therapy or reaching serum creatinine peak was associated with lower overall survival even when adjusted for significant potential confounders (HR 1.03; 95% CI 1.01, 1.05; p=0.002). Overall, patients experiencing acute kidney injury lasting for a week or more before initiation of replacement therapy experienced a threefold increase in risk of death (HR 3.02; 95% CI 2.04, 4.46; ptransplantation is remarkably frequent and has a substantial impact

  11. Assessment of human exposure to fumonisin B1

    NARCIS (Netherlands)

    Nijs, M. de; Egmond, H.P. van; Nauta, M.; Rombouts, F.M.; Notermans, S.H.W.

    1998-01-01

    Fumonisin B1 is currently regarded as the most significant mycotoxin produced by Fusarium spp. It has carcinogenic properties and may play a role in the etiology of human esophageal cancer. The human population is exposed to fumonisin B1 primarily by intake of fumonisin B1-contaminated maize. Maize

  12. Human Exposure to Herpesvirus B–Seropositive Macaques, Bali, Indonesia

    Science.gov (United States)

    Engel, Gregory A.; Schillaci, Michael A.; Suaryana, Komang Gde; Putra, Artha; Fuentes, Agustin; Henkel, Richard

    2002-01-01

    Herpesvirus B (Cercopithecine herpesvirus 1) has been implicated as the cause of approximately 40 cases of meningoencephalitis affecting persons in direct or indirect contact with laboratory macaques. However, the threat of herpesvirus B in nonlaboratory settings worldwide remains to be addressed. We investigated the potential for exposure to herpesvirus B in workers at a “monkey forest” (a temple that has become a tourist attraction because of its monkeys) in Bali, Indonesia. In July 2000, 105 workers at the Sangeh Monkey Forest in Central Bali were surveyed about contact with macaques (Macaca fascicularis). Nearly half of those interviewed had either been bitten or scratched by a macaque. Prevalence of injury was higher in those who fed macaques. Serum from 31 of 38 Sangeh macaques contained antibodies to herpesvirus B. We conclude that workers coming into contact with macaques at the Sangeh Monkey Forest are at risk for exposure to herpesvirus B. PMID:12141963

  13. Human exposure to herpesvirus B-seropositive macaques, Bali, Indonesia.

    Science.gov (United States)

    Engel, Gregory A; Jones-Engel, Lisa; Schillaci, Michael A; Suaryana, Komang Gde; Putra, Artha; Fuentes, Agustin; Henkel, Richard

    2002-08-01

    Herpesvirus B (Cercopithecine herpesvirus 1) has been implicated as the cause of approximately 40 cases of meningoencephalitis affecting persons in direct or indirect contact with laboratory macaques. However, the threat of herpesvirus B in nonlaboratory settings worldwide remains to be addressed. We investigated the potential for exposure to herpesvirus B in workers at a "monkey forest" (a temple that has become a tourist attraction because of its monkeys) in Bali, Indonesia. In July 2000, 105 workers at the Sangeh Monkey Forest in Central Bali were surveyed about contact with macaques (Macaca fascicularis). Nearly half of those interviewed had either been bitten or scratched by a macaque. Prevalence of injury was higher in those who fed macaques. Serum from 31 of 38 Sangeh macaques contained antibodies to herpesvirus B. We conclude that workers coming into contact with macaques at the Sangeh Monkey Forest are at risk for exposure to herpesvirus B.

  14. Critical elements for human health risk assessment of less than lifetime exposures.

    Science.gov (United States)

    Geraets, Liesbeth; Nijkamp, Monique M; Ter Burg, Wouter

    2016-11-01

    Less than lifetime exposure has confronted risk assessors as to how to interpret the risks for human health in case a chronic health-based limit is exceeded. Intermittent, fluctuating and peak exposures do not match with the basis of the chronic limit values possibly leading to conservative outcomes. This paper presents guidance on how to deal with human risk assessment of less than lifetime exposure. Important steps to be considered are characterization of the human exposure situation, evaluation whether the human less than lifetime exposure scenario corresponds to a non-chronic internal exposure: toxicokinetic and toxicodynamic considerations, and, finally, re-evaluation of the risk assessment. Critical elements for these steps are the mode of action, Haber's rule, and toxicokinetics (ADME) amongst others. Previous work for the endpoints non-genotoxic carcinogenicity and developmental toxicity is included in the guidance. The guidance provides a way to consider the critical elements, without setting default factors to correct for the less than lifetime exposure in risk assessment.

  15. Lead Exposure Induces Telomere Instability in Human Cells.

    Directory of Open Access Journals (Sweden)

    Géraldine Pottier

    Full Text Available Lead (Pb is an important environmental contaminant due to its widespread use over many centuries. While it affects primarily every organ system of the body, the most pernicious effects of Pb are on the central nervous system leading to cognitive and behavioral modification. Despite decades of research, the mechanisms responsible for Pb toxicity remain poorly understood. Recent work has suggested that Pb exposure may have consequences on chromosomal integrity as it was shown that Pb exposure leads to the generation of γH2Ax foci, a well-established biomarker for DNA double stranded break (DSB formation. As the chromosomal localization of γH2Ax foci plays an important role in determining the molecular mechanism responsible for their formation, we examined the localization of Pb-induced foci with respect to telomeres. Indeed, short or dysfunctional telomeres (uncapped or damaged telomeres may be recognized as DSB by the DNA repair machinery, leading to "telomere-Induced Foci" (TIFs. In the current study, we show that while Pb exposure did not increase intra-chromosomal foci, it significantly induced TIFs, leading in some cases, to chromosomal abnormalities including telomere loss. The evidence suggests that these chromosomal abnormalities are likely due to perturbation of telomere replication, in particular on the lagging DNA strand. We propose a mechanism by which Pb exposure leads to the loss of telomere maintenance. As numerous studies have demonstrated a role for telomere maintenance in brain development and tissue homeostasis, our results suggest a possible mechanism for lead-induced neurotoxicity.

  16. Novel Human Radiation Exposure Biomarker Panel Applicable for Population Triage

    Energy Technology Data Exchange (ETDEWEB)

    Bazan, Jose G. [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Chang, Polly; Balog, Robert; D' Andrea, Annalisa; Shaler, Thomas; Lin, Hua; Lee, Shirley; Harrison, Travis [SRI International, Menlo Park, California (United States); Shura, Lei; Schoen, Lucy; Knox, Susan J. [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Cooper, David E., E-mail: david.cooper@sri.com [SRI International, Menlo Park, California (United States)

    2014-11-01

    Purpose: To identify a panel of radiation-responsive plasma proteins that could be used in a point-of-care biologic dosimeter to detect clinically significant levels of ionizing radiation exposure. Methods and Materials: Patients undergoing preparation for hematopoietic cell transplantation using radiation therapy (RT) with either total lymphoid irradiation or fractionated total body irradiation were eligible. Plasma was examined from patients with potentially confounding conditions and from normal individuals. Each plasma sample was analyzed for a panel of 17 proteins before RT was begun and at several time points after RT exposure. Paired and unpaired t tests between the dose and control groups were performed. Conditional inference trees were constructed based on panels of proteins to compare the non-RT group with the RT group. Results: A total of 151 patients (62 RT, 41 infection, 48 trauma) were enrolled on the study, and the plasma from an additional 24 healthy control individuals was analyzed. In comparison with to control individuals, tenascin-C was upregulated and clusterin was downregulated in patients receiving RT. Salivary amylase was strongly radiation responsive, with upregulation in total body irradiation patients and slight downregulation in total lymphoid irradiation patients compared with control individuals. A panel consisting of these 3 proteins accurately distinguished between irradiated patients and healthy control individuals within 3 days after exposure: 97% accuracy, 0.5% false negative rate, 2% false positive rate. The accuracy was diminished when patients with trauma, infection, or both were included (accuracy, 74%-84%; false positive rate, 14%-33%, false negative rate: 8%-40%). Conclusions: A panel of 3 proteins accurately distinguishes unirradiated healthy donors from those exposed to RT (0.8-9.6 Gy) within 3 days of exposure. These findings have significant implications in terms of triaging individuals in the case of nuclear or other

  17. Acute High-Dose and Chronic Lifetime Exposure to Alcohol Consumption and Differentiated Thyroid Cancer: T-CALOS Korea.

    Directory of Open Access Journals (Sweden)

    Yunji Hwang

    Full Text Available This study evaluated the effects of acute high-dose and chronic lifetime exposure to alcohol and exposure patterns on the development of differentiated thyroid cancer (DTC.The Thyroid Cancer Longitudinal Study (T-CALOS included 2,258 DTC patients (449 men and 1,809 women and 22,580 healthy participants (4,490 men and 18,090 women who were individually matched by age, gender, and enrollment year. In-person interviews were conducted with a structured questionnaire to obtain epidemiologic data. Clinicopathologic features of the patients were obtained by chart reviews. Odds ratios (ORs and 95% confidence intervals (95%CI were estimated using conditional regression models.While light or moderate drinking behavior was related to a reduced risk of DTC, acute heavy alcohol consumption (151 g or more per event or on a single occasion was associated with increased risks in men (OR = 2.22, 95%CI = 1.27-3.87 and women (OR = 3.61, 95%CI = 1.52-8.58 compared with never-drinkers. The consumption of alcohol for 31 or more years was a significant risk factor for DTC for both men (31-40 years: OR = 1.58, 95%CI = 1.10-2.28; 41+ years: OR = 3.46, 95%CI = 2.06-5.80 and women (31-40 years: OR = 2.18, 95%CI = 1.62-2.92; 41+ years: OR = 2.71, 95%CI = 1.36-5.05 compared with never-drinkers. The consumption of a large amount of alcohol on a single occasion was also a significant risk factor, even after restricting DTC outcomes to tumor size, lymph node metastasis, extrathyroidal extension and TNM stage.The findings of this study suggest that the threshold effects of acute high-dose alcohol consumption and long-term alcohol consumption are linked to an increased risk of DTC.

  18. Clinical and pathological manifestations of cardiovascular disease in rat models: the influence of acute ozone exposure

    Science.gov (United States)

    This paper shows that rat models of cardiovascular diseases have differential degrees of underlying pathologies at a young age. Rodent models of cardiovascular diseases (CVD) and metabolic disorders are used for examining susceptibility variations to environmental exposures. How...

  19. Liver histopathology of the fish brachydanio rerio hamilton-buchman after acute exposure to sublethal levels of the organophosphate dimethoate 500

    Directory of Open Access Journals (Sweden)

    Edson de Lara Rodrigues

    1998-01-01

    Full Text Available Among the new substances that were synthesised by the chemical industiy during the last decades, with the aim to improve human prosperity, some cause negative effects on non target organisms like fish. Among the pesticides, the organophosphates (OP are widely used in cattle management, agriculture and aquaculture activities. Brachydanio rerio Hamilton-Buchman, 1822 is used world-wide in fish-tests for the establishment of the lethal levels of pesticides. Nevertheless, these fish show morphological changes in their hepatocytes when exposed experimentally for 24 hours to the sublethal dose of 0.025 µl/l of the OP Dimethoate 500, in acute tests. Right hours after exposure, a high density of cells with cytoplasmic granulation is seen as well as focal necrosis. The main changes that occurred in the first 24 hours of exposure were the loss of the typical polygonal cell shape and of detectable cell limits, lateral migration of nuclei, nuclear size and shape, condensation of chromatin and pycnosis, increased cytoplasmic granulation followed by vacuolisation. After 48 hours in clean water, 72 hours from contamination, besides significant morphological changes and necrosis, focal regeneration of the hepatocytes, canaliculi, ducts and sinusoids were seen. Even having been exposed to the half of the dose considered as safe according to the general pesticide allowance rules, significant changes of the liver tissue were observed.

  20. Exploring uncoupling proteins and antioxidant mechanisms under acute cold exposure in brains of fish.

    Directory of Open Access Journals (Sweden)

    Yung-Che Tseng

    Full Text Available Exposure to fluctuating temperatures accelerates the mitochondrial respiration and increases the formation of mitochondrial reactive oxygen species (ROS in ectothermic vertebrates including fish. To date, little is known on potential oxidative damage and on protective antioxidative defense mechanisms in the brain of fish under cold shock. In this study, the concentration of cellular protein carbonyls in brain was significantly increased by 38% within 1 h after cold exposure (from 28 °C to 18 °C of zebrafish (Danio rerio. In addition, the specific activity of superoxide dismutase (SOD and the mRNA level of catalase (CAT were increased after cold exposure by about 60% (6 h and by 60%-90% (1 and 24 h, respectively, while the specific glutathione content as well as the ratio of glutathione disulfide to glutathione remained constant and at a very low level. In addition, cold exposure increased the protein level of hypoxia-inducible factor (HIF by about 50% and the mRNA level of the glucose transporter zglut3 in brain by 50%-100%. To test for an involvement of uncoupling proteins (UCPs in the cold adaptation of zebrafish, five UCP members were annotated and identified (zucp1-5. With the exception of zucp1, the mRNA levels of the other four zucps were significantly increased after cold exposure. In addition, the mRNA levels of four of the fish homologs (zppar of the peroxisome proliferator-activated receptor (PPAR were increased after cold exposure. These data suggest that PPARs and UCPs are involved in the alterations observed in zebrafish brain after exposure to 18°C. The observed stimulation of the PPAR-UCP axis may help to prevent oxidative damage and to maintain metabolic balance and cellular homeostasis in the brains of ectothermic zebrafish upon cold exposure.

  1. Acute exposure to high environmental ammonia (HEA) triggers the emersion response in the green shore crab.

    Science.gov (United States)

    Zimmer, Alex M; Wood, Chris M

    2017-02-01

    The physiological effects of high environmental ammonia (HEA) exposure have been well documented in many aquatic species. In particular, it has recently been demonstrated that exposure to ammonia in fish leads to a similar hyperventilatory response as observed during exposure to hypoxia. In littoral crabs, such as the green crab (Carcinus maenas), exposure to severe hypoxia triggers an emersion response whereby crabs escape hypoxia to breathe air. We hypothesized that exposure to HEA in green crabs would lead to a similar behavioural response which is specific to ammonia. Using an experimental arena containing a rock bed onto which crabs could emerse, we established that exposure to HEA (4mmol/l NH4HCO3) for 15min triggers emersion in crabs. In experiments utilizing NaHCO3 controls and NH4HCO3 injections, we further determined that emersion was triggered specifically by external ammonia and was independent of secondary acid-base or respiratory disturbances caused by HEA. We then hypothesized that emersion from HEA provides a physiological benefit, similar to emersion from hypoxia. Exposure to 15min of HEA without emersion (no rock bed present) caused significant increases in arterial haemolymph total ammonia (Tamm), pH, and [HCO3(-)]. When emersion was allowed, arterial haemolymph Tamm and [HCO3(-)] increased, but no alkalosis developed. Moreover, emersion decreased haemolymph partial pressure of NH3 relative to crabs which could not emerse. Overall, we demonstrate a novel behavioural response to HEA exposure in crabs which we propose may share similar mechanistic pathways with the emersion response triggered by hypoxia.

  2. Renal excretion in coho salmon (Oncorhynchus kisutch) after acute exposure to 3-trifluoromethyl-4-nitrophenol

    Science.gov (United States)

    Hunn, J.B.; Allen, J.L.

    1975-01-01

    COHO SALMON (ONCORHYNCHUS KISUTCH) EXPOSED TO AN ACUTE, SUBLETHAL CONCENTRATION OF 3-TRIFLUOROMETHLY 1-4 NITROPHENOL (TFM) EXHIBITED AN INCREASED OUTPUT OF URINE WHEN COMPARED WITH CONTROLS, BUT THE URINARY EXCRETION OF NA, K, CA, MG AND C1 WAS NOT AFFECTED. ABOUT 35 TIMES MORE CONJUGATED TFM THAN FREE TFM WAS EXCRETED DURING THE 24-HOUR STUDY PERIOD.

  3. Effect of Acute Noise Exposure on Salivary Cortisol: A Randomized Controlled Trial.

    Science.gov (United States)

    Pouryaghoub, Gholamreza; Mehrdad, Ramin; Valipouri, Alireza

    2016-10-01

    Cardiovascular adverse effects are interesting aspects of occupational noise exposure. One possible mechanism of these effects is an alternation in hypothalamic-pituitary-adrenal axis. Our aim was to measure salivary cortisol response to relatively high-intensity noise exposure in a controlled randomized trial study. We exposed 50 male volunteers to 90 dBA noise for 20 minutes and compared their level of salivary cortisol with 50 non-exposed controls. Salivary samples obtained before and after exposure. Before intervention means (SD) salivary cortisol level were 3.24 (0.47)ng/ml and 3.25 (0.41)ng/ml for exposed and non-exposed groups respectively. Mean salivary cortisol level increased to 4.17 ng/mlafter intervention in exposure group. This increment was statistically significant (P=0.00). Mean salivary cortisol level of the non-exposed group had statistically non-significant decrement after this period (0.2 ng/ml). The difference between salivary cortisol level of non-exposed and exposed groups after the intervention was statistically significant. Noise exposure may affect the hypothalamic-pituitary-adrenal axis activity, and this may be one of the mechanisms of noise exposure cardiovascular effects.

  4. Efficacy of Acute Intermittent Hypoxia on Physical Function and Health Status in Humans with Spinal Cord Injury: A Brief Review

    Directory of Open Access Journals (Sweden)

    Todd A. Astorino

    2015-01-01

    Full Text Available Spinal cord injury (SCI results in a loss of motor and sensory function and is consequent with reductions in locomotion, leading to a relatively sedentary lifestyle which predisposes individuals to premature morbidity and mortality. Many exercise modalities have been employed to improve physical function and health status in SCI, yet they are typically expensive, require many trained clinicians to implement, and are thus relegated to specialized rehabilitation centers. These characteristics of traditional exercise-based rehabilitation in SCI make their application relatively impractical considering the time-intensive nature of these regimens and patients’ poor access to exercise. A promising approach to improve physical function in persons with SCI is exposure to acute intermittent hypoxia (IH in the form of a small amount of sessions of brief, repeated exposures to low oxygen gas mixtures interspersed with normoxic breathing. This review summarizes the clinical application of IH in humans with SCI, describes recommended dosing and potential side effects of IH, and reviews existing data concerning the efficacy of relatively brief exposures of IH to modify health and physical function. Potential mechanisms explaining the effects of IH are also discussed. Collectively, IH appears to be a safe, time-efficient, and robust approach to enhance physical function in chronic, incomplete SCI.

  5. Transient activation of microglia following acute alcohol exposure in developing mouse neocortex is primarily driven by BAX-dependent neurodegeneration.

    Science.gov (United States)

    Ahlers, Katelin E; Karaçay, Bahri; Fuller, Leah; Bonthius, Daniel J; Dailey, Michael E

    2015-10-01

    Fetal alcohol exposure is the most common known cause of preventable mental retardation, yet we know little about how microglia respond to, or are affected by, alcohol in the developing brain in vivo. Using an acute (single day) model of moderate (3 g/kg) to severe (5 g/kg) alcohol exposure in postnatal day (P) 7 or P8 mice, we found that alcohol-induced neuroapoptosis in the neocortex is closely correlated in space and time with the appearance of activated microglia near dead cells. The timing and molecular pattern of microglial activation varied with the level of cell death. Although microglia rapidly mobilized to contact and engulf late-stage apoptotic neurons, apoptotic bodies temporarily accumulated in neocortex, suggesting that in severe cases of alcohol toxicity the neurodegeneration rate exceeds the clearance capacity of endogenous microglia. Nevertheless, most dead cells were cleared and microglia began to deactivate within 1-2 days of the initial insult. Coincident with microglial activation and deactivation, there was a transient increase in expression of pro-inflammatory factors, TNFα and IL-1β, after severe (5 g/kg) but not moderate (3 g/kg) EtOH levels. Alcohol-induced microglial activation and pro-inflammatory factor expression were largely abolished in BAX null mice lacking neuroapoptosis, indicating that microglial activation is primarily triggered by apoptosis rather than the alcohol. Therefore, acute alcohol exposure in the developing neocortex causes transient microglial activation and mobilization, promoting clearance of dead cells and tissue recovery. Moreover, cortical microglia show a remarkable capacity to rapidly deactivate following even severe neurodegenerative insults in the developing brain.

  6. Maternal benzene exposure during pregnancy and risk of childhood acute lymphoblastic leukemia: a meta-analysis of epidemiologic studies.

    Directory of Open Access Journals (Sweden)

    Yanfeng Zhou

    Full Text Available The prevalence of childhood leukemia is increasing rapidly all over the world. However, studies on maternal benzene exposure during pregnancy and childhood acute lymphoblastic leukemia (ALL have not been systematically assessed. Therefore, we performed a meta-analysis to investigate the association between maternal solvent, paint, petroleum exposure, and smoking during pregnancy and risk of childhood ALL.Relevant studies up to September 1st, 2013 were identified by searching the PubMed, EMBASE, Cochrane library and the Web of Science databases. The effects were pooled using either fixed or random effect models based on the heterogeneity of the studies.Twenty-eight case-control studies and one cohort study were included for analysis, with a total of 16,695 cases and 1,472,786 controls involved. Pooled odds ratio (OR with 95% confidence interval (CI for ALL was 1.25 (1.09, 1.45 for solvent, 1.23 (1.02, 1.47 for paint, 1.42 (1.10, 1.84 for petroleum exposure, and 0.99 (0.93, 1.06 for maternal smoking during pregnancy. No publication bias was found in this meta-analysis and consistent results were observed for subgroup and sensitivity analyses.Childhood ALL was associated with maternal solvent, paint, and petroleum exposure during pregnancy. No association was found between ALL and maternal smoking during pregnancy. Avoidance of maternal occupational and environmental benzene exposure during pregnancy could contribute to a decrease in the risk of childhood ALL.

  7. Acute exposure to selenium disrupts associative conditioning and long-term memory recall in honey bees (Apis mellifera).

    Science.gov (United States)

    Burden, Christina M; Elmore, Christopher; Hladun, Kristen R; Trumble, John T; Smith, Brian H

    2016-05-01

    A plethora of toxic compounds - including pesticides, heavy metals, and metalloids - have been detected in honey bees (Apis mellifera) and their colonies. One such compound is selenium, which bees are exposed to by consuming nectar and pollen from flowers grown in contaminated areas. Though selenium is lethal at high concentrations, sublethal exposure may also impair honey bees' ability to function normally. Examining the effect of selenium exposure on learning and memory provides a sensitive assay with which to identify sublethal effects on honey bee health and behavior. To determine whether sublethal selenium exposure causes learning and memory deficits, we used proboscis extension reflex conditioning coupled with recall tests 30min and 24h post-conditioning. We exposed forager honey bees to a single sublethal dose of selenium, and 3h later we used an olfactory conditioning assay to train the bees to discriminate between one odor associated with sucrose-reinforcement and a second unreinforced odor. Following conditioning we tested short- and long-term recall of the task. Acute exposure to as little as 1.8ng of an inorganic form of selenium (sodium selenate) before conditioning caused a reduction in behavioral performance during conditioning. And, exposure to 18ng of either an inorganic form (sodium selenate) or an organic form (methylseleno-l-cysteine) of selenium caused a reduction in the bees' performance during the long-term recall test. These concentrations of selenium are lower than those found in the nectar of plants grown in selenium-contaminated soil, indicating that even low-grade selenium toxicity produces significant learning and memory impairments. This may reduce foragers' ability to effectively gather resources for the colony or nurse bees' ability to care for and maintain a healthy colony.

  8. Time course of systemic oxidative stress and inflammatory response induced by an acute exposure to Residual Oil Fly Ash.

    Science.gov (United States)

    Marchini, T; Magnani, N D; Paz, M L; Vanasco, V; Tasat, D; González Maglio, D H; Alvarez, S; Evelson, P A

    2014-01-15

    It is suggested that systemic oxidative stress and inflammation play a central role in the onset and progression of cardiovascular diseases associated with the exposure to particulate matter (PM). The aim of this work was to evaluate the time changes of systemic markers of oxidative stress and inflammation, after an acute exposure to Residual Oil Fly Ash (ROFA). Female Swiss mice were intranasally instilled with a ROFA suspension (1.0mg/kg body weight) or saline solution, and plasma levels of oxidative damage markers [thiobarbituric acid reactive substances (TBARSs) and protein carbonyls], antioxidant status [reduced (GSH) and oxidized (GSSG) glutathione, ascorbic acid levels, and superoxide dismutase (SOD) activity], cytokines levels, and intravascular leukocyte activation were evaluated after 1, 3 or 5h of exposure. Oxidative damage to lipids and decreased GSH/GSSG ratio were observed in ROFA-exposed mice as early as 1h. Afterwards, increased protein oxidation, decreased ascorbic acid content and SOD activity were found in this group at 3h. The onset of an adaptive response was observed at 5h after the ROFA exposure, as indicated by decreased TBARS plasma content and increased SOD activity. The observed increase in oxidative damage to plasma macromolecules, together with systemic antioxidants depletion, may be a consequence of a systemic inflammatory response triggered by the ROFA exposure, since increased TNF-α and IL-6 plasma levels and polymorphonuclear leukocytes activation was found at every evaluated time point. These findings contribute to the understanding of the increase in cardiovascular morbidity and mortality, in association with environmental PM inhalation.

  9. Acute Effects of Viral Exposure on P-Glycoprotein Function in the Mouse Fetal Blood-Brain Barrier

    Directory of Open Access Journals (Sweden)

    Enrrico Bloise

    2017-02-01

    Full Text Available Background/Aims: Viral infection during pregnancy is known to affect the fetal brain. The toll-like receptor (TLR-3 is a pattern recognition receptor activated by viruses known to elicit adverse fetal neurological outcomes. The P-glycoprotein (P-gp efflux transporter protects the developing fetus by limiting the transfer of substrates across both the placenta and the fetal blood-brain barrier (BBB. As such, inhibition of P-gp at these blood-barrier sites may result in increased exposure of the developing fetus to environmental toxins and xenobiotics present in the maternal circulation. We hypothesized that viral exposure during pregnancy would impair P-gp function in the placenta and in the developing BBB. Here we investigated whether the TLR-3 ligand, polyinosinic:polycytidylic acid (PolyI:C, increased accumulation of one P-gp substrate in the fetus and in the developing fetal brain. Methods: Pregnant C57BL/6 mice (GD15.5 were injected (i.p. with PolyI:C (5 mg/kg or 10 mg/kg or vehicle (saline. [3H]digoxin (P-gp substrate was injected (i.v. 3 or 23h post-treatment and animals were euthanized 1h later. Maternal plasma, ‘fetal-units’ (fetal membranes, amniotic fluid and whole fetus, and fetal brains were collected. Results: PolyI:C exposure (4h significantly elevated maternal plasma IL-6 (P<0.001 and increased [3H]digoxin accumulation in the fetal brain (P<0.05. In contrast, 24h after PolyI:C exposure, no effect on IL-6 or fetal brain accumulation of P-gp substrate was observed. Conclusion: Viral infection modeled by PolyI:C causes acute increases in fetal brain accumulation of P-gp substrates and by doing so, may increase fetal brain exposure to xenobiotics and environmental toxins present in the maternal circulation.

  10. Human Parotid Gland Alpha-Amylase Secretion as a Function of Chronic Hyperbaric Exposure

    Science.gov (United States)

    1979-01-01

    parotid ...Pullman, WA 99163 Gilman, S. C, G. J. Fischer, R. J. Biersner, R. D. Thornton, and D. A. Miller. 1979. Human parotid gland alpha-amylase secretion...as a function of chronic hyperbaric exposure. Undersea Biomed. Res. 6(3):303-307.—Secretion of a-amylase by the human parotid gland increased

  11. Human Infection with MERS coronavirus after exposure to infected camels, Saudi Arabia, 2013

    NARCIS (Netherlands)

    Memish, Ziad A.; Cotten, Matthew; Meyer, Benjamin; Watson, Simon J.; Alsahafi, Abdullah J.; Al Rabeeah, Abdullah A.; Corman, Victor Max; Sieberg, Andrea; Makhdoom, Hatem Q.; Assiri, Abdullah; Al Masri, Malaki; Aldabbagh, Souhaib; Bosch, Berend Jan; Beer, Martin; Müller, Marcel A.; Kellam, Paul; Drosten, Christian

    2014-01-01

    We investigated a case of human infection with Middle East respiratory syndrome coronavirus (MERS-CoV) after exposure to infected camels. Analysis of the whole human-derived virus and 15% of the camel-derived virus sequence yielded nucleotide polymorphism signatures suggestive of cross-species trans

  12. A Chain Modeling Approach To Estimate the Impact of Soil Cadmium Pollution on Human Dietary Exposure

    NARCIS (Netherlands)

    Franz, E.; Romkens, P.F.A.M.; Raamsdonk, van L.W.D.; Fels-Klerx, van der H.J.

    2008-01-01

    Cadmium in soil poses a risk for human health, due to its accumulation in food and feed crops. The extent of accumulation depends strongly on soil type and the degree of pollution. The objective of the present study was to develop a predictive model to estimate human dietary cadmium exposure from so

  13. Ochratoxin A in Portugal: A Review to Assess Human Exposure

    Directory of Open Access Journals (Sweden)

    Sofia C. Duarte

    2010-06-01

    Full Text Available In Portugal, the climate, dietary habits, and food contamination levels present the characteristics for higher population susceptibility to ochratoxin A (OTA, one of the known mycotoxins with the greatest public health and agro-economic importance. In this review, following a brief historical insight on OTA research, a summary of the available data on OTA occurrence in food (cereals, bread, wine, meat and biological fluids (blood, urine is made. With this data, an estimation of intake is made to ascertain and update the risk exposure estimation of the Portuguese population, in comparison to previous studies and other populations.

  14. Age-dependence of responses to acute ozone exposure in rats

    Energy Technology Data Exchange (ETDEWEB)

    Gunnison, A.F.; Weideman, P.A.; Sobo, M.; Koenig, K.L.; Chen, L.C. (Institute of Environmental Medicine, New York University Medical Center, New York (United States))

    1992-04-01

    In the study reported here, we have extended our initial investigation to include the influence of animal age on temporal aspects of pulmonary AA metabolism and several other responses to brief exposures to 1 ppm ozone. Rats of discrete ages ranging from 13 days to 16 weeks were exposed to 1 ppm ozone or to air for 2, 4, or 6 hr. Immediately following exposure the lungs were lavaged with six consecutive volumes of phosphate-buffered saline and the acellular fluid from the first lavage volume recovered was analyzed for its content of prostaglandin E2 (PGE2), protein, and lactate dehydrogenase. Leukocytes recovered by lavage were quantitated and characterized by viability and percentage of polymorphonuclear (PMN) cells. Several lines of evidence verified that PGE2 was produced by the lung as a consequence of ozone exposure and that its concentration in the fluid from the first lavage was a reasonably good index of pulmonary AA metabolism to prostanoids. We also demonstrated that the lavage process itself stimulates the lung, resulting in increased AA metabolism to prostanoids that were recovered in the second and following lavage volumes. The time course of PGE2 production by the ozone-exposed lung varied considerably with animal age. Neonatal rats 13 days of age were the most sensitive to ozone stimulation. At 2 hr of exposure, PGE2 concentration in the first lung lavage of these animals peaked at values approximately two orders of magnitude above controls and then decreased sharply with continued exposure. Adults and older neonates (18 days of age) were much less responsive to 2-hr exposures; however, continued exposure of these rats for up to 6 hr resulted in increasing PGE2 concentration in the first lung lavage. Other responses showed various degree of age dependence.

  15. Exposure measurement of aflatoxins and aflatoxin metabolites in human body fluids. A short review.

    Science.gov (United States)

    Leong, Yin-Hui; Latiff, Aishah A; Ahmad, Nurul Izzah; Rosma, Ahmad

    2012-05-01

    Aflatoxins are highly toxic secondary fungal metabolites mainly produced by Aspergillus flavus and A. parasiticus. Human exposure to aflatoxins may result directly from ingestion of contaminated foods, or indirectly from consumption of foods from animals previously exposed to aflatoxins in feeds. This paper focuses on exposure measurement of aflatoxins and aflatoxin metabolites in various human body fluids. Research on different metabolites present in blood, urine, breast milk, and other human fluids or tissues including their detection techniques is reviewed. The association between dietary intake of aflatoxins and biomarker measurement is also highlighted. Finally, aspects related to the differences between aflatoxin determination in food versus the biomarker approach are discussed.

  16. Acute Activation of Oxidative Pentose Phosphate Pathway as First-Line Response to Oxidative Stress in Human Skin Cells.

    Science.gov (United States)

    Kuehne, Andreas; Emmert, Hila; Soehle, Joern; Winnefeld, Marc; Fischer, Frank; Wenck, Horst; Gallinat, Stefan; Terstegen, Lara; Lucius, Ralph; Hildebrand, Janosch; Zamboni, Nicola

    2015-08-01

    Integrity of human skin is endangered by exposure to UV irradiation and chemical stressors, which can provoke a toxic production of reactive oxygen species (ROS) and oxidative damage. Since oxidation of proteins and metabolites occurs virtually instantaneously, immediate cellular countermeasures are pivotal to mitigate the negative implications of acute oxidative stress. We investigated the short-term metabolic response in human skin fibroblasts and keratinocytes to H2O2 and UV exposure. In time-resolved metabolomics experiments, we observed that within seconds after stress induction, glucose catabolism is routed to the oxidative pentose phosphate pathway (PPP) and nucleotide synthesis independent of previously postulated blocks in glycolysis (i.e., of GAPDH or PKM2). Through ultra-short (13)C labeling experiments, we provide evidence for multiple cycling of carbon backbones in the oxidative PPP, potentially maximizing NADPH reduction. The identified metabolic rerouting in oxidative and non-oxidative PPP has important physiological roles in stabilization of the redox balance and ROS clearance.

  17. Effect of acute pesticide exposure on bee spatial working memory using an analogue of the radial-arm maze

    Science.gov (United States)

    Samuelson, Elizabeth E. W.; Chen-Wishart, Zachary P.; Gill, Richard J.; Leadbeater, Ellouise

    2016-12-01

    Pesticides, including neonicotinoids, typically target pest insects by being neurotoxic. Inadvertent exposure to foraging insect pollinators is usually sub-lethal, but may affect cognition. One cognitive trait, spatial working memory, may be important in avoiding previously-visited flowers and other spatial tasks such as navigation. To test this, we investigated the effect of acute thiamethoxam exposure on spatial working memory in the bumblebee Bombus terrestris, using an adaptation of the radial-arm maze (RAM). We first demonstrated that bumblebees use spatial working memory to solve the RAM by showing that untreated bees performed significantly better than would be expected if choices were random or governed by stereotyped visitation rules. We then exposed bees to either a high sub-lethal positive control thiamethoxam dose (2.5 ng‑1 bee), or one of two low doses (0.377 or 0.091 ng‑1) based on estimated field-realistic exposure. The high dose caused bees to make more and earlier spatial memory errors and take longer to complete the task than unexposed bees. For the low doses, the negative effects were smaller but statistically significant, and dependent on bee size. The spatial working memory impairment shown here has the potential to harm bees exposed to thiamethoxam, through possible impacts on foraging efficiency or homing.

  18. Acute non-cancer mortality excess after polychlorinated biphenyls and polychlorinated dibenzofurans mixed exposure from contaminated rice oil: Yusho.

    Science.gov (United States)

    Kashima, Saori; Yorifuji, Takashi; Tsuda, Toshihide

    2011-08-15

    In Japan in 1968, rice-oil contaminated by polychlorinated biphenyls and polychlorinated dibenzofurans caused severe food poisoning, termed "Yusho" (oil disease). Several previous studies attempted to evaluate the effects targeting officially-certified Yusho patients. However, these studies have several limitations such as the left-truncated nature of the registry or residual confounding arising from the referent population selection. We thus conducted an area-based standardized mortality ratios (SMRs) study using vital statistics. A severely affected area (Tamanoura area) was adopted as the exposure group, with a reference population from Nagasaki prefecture in Kyushu, which included the Tamanoura. A large number of residents in Tamanoura were exposed to the rice-oil (28% of all the certified cases as of 2009). We estimated SMRs of non-cancer and cancer diseases for the years 1968-2002. Shortly after the exposure, SMRs of all causes, diabetes mellitus, cardiovascular disease, pneumonia/bronchitis, and bronchus/lung cancer were elevated. In particular, SMRs of heart disease were 1.97 [95% confidence intervals (CI): 1.09-3.56] in 1968, 2.05 (95% CI: 1.16-3.60) in 1969, and 1.89 (95% CI: 1.05-3.41) in 1975. However, we did not observe clear increase in SMRs more than 10 years after the exposure. This study provides further evidence in Yusho, especially on acute effects on non-cancer mortality. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Associations of acute exposure to fine and coarse particulate matter and mortality among older people in Tokyo, Japan.

    Science.gov (United States)

    Yorifuji, Takashi; Kashima, Saori; Doi, Hiroyuki

    2016-01-15

    Recent studies have reported adverse health effects of short-term exposure to coarse particles independent of particulate matter less than 2.5 μm in diameter (PM2.5), but evidence in Asian countries is limited. We therefore evaluated associations between short-term exposure to particulate matter (PM) and mortality among older people in Tokyo, Japan. We used a time-stratified, case-crossover design. Study participants included 664,509 older people (≥65 years old) in the 23 urbanized wards of the Tokyo Metropolitan Government, who died between January 2002 and December 2013. We obtained PM2.5 and suspended particulate matter (SPM; PMrespiratory diseases; for example, both pollutants were positively associated with increased risk of all-cause mortality even after simultaneous adjustment for each pollutant: OR of 1.006 (95% CI: 1.003, 1.009) for PM2.5 and 1.016 (95% CI: 1.011, 1.022) for PM7-2.5. Even below concentrations stipulated by the Japanese air quality guidelines for PM2.5 and SPM (PM7), we observed adverse health effects. This study provides further evidence that acute exposure to PM2.5 and coarse particles is associated with increased risk of mortality among older people. Rigorous evaluation of air quality guidelines for daily average PM2.5 and larger particles should be continued.

  20. Acute cold- and chronic heat-exposure upregulate hepatic leptin and muscle uncoupling protein (UCP) gene expression in broiler chickens.

    Science.gov (United States)

    Dridi, Sami; Temim, Soraya; Derouet, Michel; Tesseraud, Sophie; Taouis, Mohammed

    2008-08-01

    Emerging evidence showed that variations in environmental temperature affect both leptin and uncoupling protein (UCP) gene expression in mammals, whereas a little is known about such interactions in birds. Thus, we conducted the present study to investigate the influence of acute (2 hours) cold (4 degrees C) and chronic (10 days) heat (32 degrees C) exposure on hepatic leptin and muscle UCP gene expression in 5-wk-old broiler chickens. Both cold- and heat-exposure significantly (P < 0.05 to P < 0.001) upregulated hepatic leptin (by 35 and 46%, respectively) and muscle UCP mRNA levels (by 71 and 71%, respectively) compared to the thermoneutrality (22 degrees C). This result suggests that leptin and UCP may be involved in the thermoregulation response of chickens to extreme climate (cold and hot temperatures). The upregulation of hepatic leptin gene expression was accompanied by an increase in plasma leptin levels, indicating that leptin may be regulated at transcriptional level. The increase of leptin and UCP mRNA abundance, and leptinemia we report here were not related to plasma glucose or insulin levels. In conclusion, the exposure of broiler chickens to extreme ambient temperatures (cold and heat) increases hepatic leptin and muscle UCP gene expression.

  1. Effect of acute pesticide exposure on bee spatial working memory using an analogue of the radial-arm maze.

    Science.gov (United States)

    Samuelson, Elizabeth E W; Chen-Wishart, Zachary P; Gill, Richard J; Leadbeater, Ellouise

    2016-12-13

    Pesticides, including neonicotinoids, typically target pest insects by being neurotoxic. Inadvertent exposure to foraging insect pollinators is usually sub-lethal, but may affect cognition. One cognitive trait, spatial working memory, may be important in avoiding previously-visited flowers and other spatial tasks such as navigation. To test this, we investigated the effect of acute thiamethoxam exposure on spatial working memory in the bumblebee Bombus terrestris, using an adaptation of the radial-arm maze (RAM). We first demonstrated that bumblebees use spatial working memory to solve the RAM by showing that untreated bees performed significantly better than would be expected if choices were random or governed by stereotyped visitation rules. We then exposed bees to either a high sub-lethal positive control thiamethoxam dose (2.5 ng(-1) bee), or one of two low doses (0.377 or 0.091 ng(-1)) based on estimated field-realistic exposure. The high dose caused bees to make more and earlier spatial memory errors and take longer to complete the task than unexposed bees. For the low doses, the negative effects were smaller but statistically significant, and dependent on bee size. The spatial working memory impairment shown here has the potential to harm bees exposed to thiamethoxam, through possible impacts on foraging efficiency or homing.

  2. Experimental Therapeutics Against the Toxic and Lethal Effects Resulting from Acute Exposure to Nerve Agents Without Carbamate Pretreatment in Guinea Pigs

    Science.gov (United States)

    2010-09-01

    The "Bradypnea" stage was generally preceded by episodes of ataxic or dyspneic breathing. Seizures and convulsions typically continued during...acute agent exposure. These included oro-facial movements (indicative of immoderate secretion), mild degree of dystonia/ ataxia , and a short period of...periods of acute cholinergic effects (mucoid-salivary secretion, dystonia, ataxia , tremors and fasciculations) were seen shortly after intoxication

  3. Mixtures of endocrine disrupting contaminants modelled on human high end exposures

    DEFF Research Database (Denmark)

    Christiansen, Sofie; Kortenkamp, A.; Petersen, Marta Axelstad

    2012-01-01

    in vivo endocrine disrupting effects and information about human exposures was available, including phthalates, pesticides, UV‐filters, bisphenol A, parabens and the drug paracetamol. The mixture ratio was chosen to reflect high end human intakes. To make decisions about the dose levels for studies...... though each individual chemical is present at low, ineffective doses, but the effects of mixtures modelled based on human intakes have not previously been investigated. To address this issue for the first time, we selected 13 chemicals for a developmental mixture toxicity study in rats where data about...... in the rat, we employed the point of departure index (PODI) approach, which sums up ratios between estimated exposure levels and no‐observed‐adverse‐effect‐level (NOAEL) values of individual substances. For high end human exposures to the 13 selected chemicals, we calculated a PODI of 0.016. As only a PODI...

  4. Assessing hazardous risks of human exposure to temple airborne polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Chiang, Kuo-Chih; Chio, Chia-Pin; Chiang, Yu-Hui; Liao, Chung-Min

    2009-07-30

    We proposed an integrated probabilistic risk assessment framework based on reported data to quantify human health risks of temple goers/workers to airborne polycyclic aromatic hydrocarbons (PAHs) from incense burning in typical Taiwanese temples. The framework probabilistically integrates exposure, human respiratory tract, and incremental lifetime cancer risk (ILCR) models to quantitatively estimate size-dependent PAHs exposure in human lung regions and cancer risks for temple goers (moderate and high exposures) and temple workers (extreme exposure). Our results show that the ILCRs are greater than the acceptable level of 10(-6) for extreme and high exposure groups through inhalation route. The result also indicates that the higher ILCRs (10(-6) to 10(-4)) are found in ingestion and dermal contact routes for temple goers/workers. For personal extreme exposure to carcinogenic PAH in the temple, 95% probability total ILCR (TILCR) (9.87 x 10(-4) to 1.13 x 10(-3)) is much greater than the range of 10(-6) to 10(-4), indicating high potential health risk to temple workers. For temple goers with high and moderate exposure groups, however, the 95% probability TILCRs were estimated from 6.44 x 10(-5) to 7.50 x 10(-5) and 5.75 x 10(-6) to 6.99 x 10(-6), respectively. This study successfully offers a scientific basis for risk analysis due to incense burning to enhance broad risk management strategies for temple indoor air quality.

  5. Effects of exposure to oil spills on human health: Updated review.

    Science.gov (United States)

    Laffon, Blanca; Pásaro, Eduardo; Valdiglesias, Vanessa

    2016-01-01

    Oil spills may involve health risks for people participating in the cleanup operations and coastal inhabitants, given the toxicological properties of the oil components. In spite of this, only after a few major oil spills (crude oil or fuel oil no. 6) have studies on effects of exposure to diverse aspects of human health been performed. Previously, Aguilera et al. (2010) examined all documents published to that date dealing with any type of human health outcome in populations exposed to oil spills. The aim of the present review was to compile all new information available and determine whether evidence reported supports the existence of an association between exposure and adverse human health risks. Studies were classified in three groups according to type of health outcome addressed: (i) effects on mental health, (ii) physical/physiological effects, and (iii) genotoxic, immunotoxic, and endocrine toxicity. New studies published on oil-spill-exposed populations-coastal residents in the vicinity of the spills or participants in cleanup operations-provide additional support to previous evidence on adverse health effects related to exposure regarding different parameters in all three categories considered. Some of the observed effects even indicated that several symptoms may persist for some years after exposure. Hence, (1) health protection in these individuals should be a matter of concern; and (2) health risk assessment needs to be carried out not only at the time of exposure but also for prolong periods following exposure, to enable early detection of any potential exposure-related harmful effects.

  6. Human milk proresolving mediators stimulate resolution of acute inflammation.

    Science.gov (United States)

    Arnardottir, H; Orr, S K; Dalli, J; Serhan, C N

    2016-05-01

    Human milk contains nutrients and bioactive products relevant to infant development and immunological protection. Here, we investigated the proresolving properties of milk using human milk lipid mediator isolates (HLMIs) and determined their impact on resolution programs in vivo and with human macrophages. HLMIs reduced the maximum neutrophil numbers (14.6±1.2 × 10(6)-11.0±1.0 × 10(6) cells per exudate) and shortened the resolution interval (Ri; 50% neutrophil reduction) by 54% compared with peritonitis. Using rigorous liquid-chromatography tandem-mass spectrometry (LC-MS-MS)-based lipid mediator (LM) metabololipidomics, we demonstrated that human milk possesses a proresolving LM-specialized proresolving mediator (LM-SPM) signature profile, containing SPMs (e.g. resolvins (Rv), protectins (PDs), maresins (MaRs), and lipoxins (LXs)) at bioactive levels (pico-nanomolar concentrations) that enhanced human macrophage efferocytosis and bacterial containment. SPMs identified in human milk included D-series Rvs (e.g., RvD1, RvD2, RvD3, AT-RvD3, and RvD4), PD1, MaR1, E-series Rvs (e.g. RvE1, RvE2, and RvE3), and LXs (LXA4 and LXB4). Of the SPMs identified in human milk, RvD2 and MaR1 (50 ng per mouse) individually shortened Ri by ∼75%. Milk from mastitis gave higher leukotriene B4 and prostanoids and lower SPM levels. Taken together, these findings provide evidence that human milk has proresolving actions via comprehensive LM-SPM profiling, describing a potentially novel mechanism in maternal-infant biochemical imprinting.

  7. Strain- and context-dependent behavioural responses of acute alarm substance exposure in zebrafish.

    Science.gov (United States)

    Quadros, Vanessa A; Silveira, Ariane; Giuliani, Giulie S; Didonet, Fernanda; Silveira, Alessandra S; Nunes, Mauro E; Silva, Tális O; Loro, Vania L; Rosemberg, Denis B

    2016-01-01

    We investigate the behavioural responses of wild type (WT) and leopard (leo) zebrafish elicited by alarm substances of conspecifics at three contexts: during the exposure period (Experiment 1); after exposure, in habituation to novelty (Experiment 2); or after exposure, in the light-dark preference test (Experiment 3), and analyse their influence on pigment response. During the exposure, leo showed decreased vertical drifts, increased number and duration of erratic movements, while WT had increased erratic movements and latency to enter the top. In the novel tank, we observed that angular velocity decreased in WT exposed to alarm substance, which also presented increased fear responses. Contrastingly, leo increased the number of entries and time in top, indicating differences in habituation profile. Alarm substance increased the number of erratic movements in the light-dark test, but elicited different responses between strains in scototaxis, latency to enter the dark compartment and risk assessment episodes. Moreover, the body colour of zebrafish did not change after alarm substance exposure. Principal component analyses suggest that burst swimming, anxiety-like behaviours, and locomotion/exploration were the components that most accounted for total variances of Experiments 1, 2, and 3, respectively. We conclude that chemical cue from conspecifics triggers strain- and context-dependent responses.

  8. In vitro exposure of human chondrocytes to pulsed electromagnetic fields

    Directory of Open Access Journals (Sweden)

    V Nicolin

    2009-08-01

    Full Text Available The effect of pulsed electromagnetic fields (PEMFs on the proliferation and survival of matrix-induced autologous chondrocyte implantation (MACI®-derived cells was studied to ascertain the healing potential of PEMFs. MACI-derived cells were taken from cartilage biopsies 6 months after surgery and cultured. No dedifferentiation towards the fibroblastic phenotype occurred, indicating the success of the surgical implantation. The MACI-derived cultured chondrocytes were exposed to 12 h/day (short term or 4 h/day (long term PEMFs exposure (magnetic field intensity, 2 mT; frequency, 75 Hz and proliferation rate determined by flow cytometric analysis. The PEMFs exposure elicited a significant increase of cell number in the SG2M cell cycle phase. Moreover, cells isolated from MACI® scaffolds showed the presence of collagen type II, a typical marker of chondrocyte functionality. The results show that MACI® membranes represent an optimal bioengineering device to support chondrocyte growth and proliferation in surgical implants. The surgical implant of MACI® combined with physiotherapy is suggested as a promising approach for a faster and safer treatment of cartilage traumatic lesions.

  9. Novel biomarkers of prenatal methamphetamine exposure in human meconium

    Science.gov (United States)

    Gray, Teresa R.; Kelly, Tamsin; LaGasse, Linda L.; Smith, Lynne M.; Derauf, Chris; Haning, William; Grant, Penny; Shah, Rizwan; Arria, Amelia; Strauss, Arthur; Lester, Barry M.; Huestis, Marilyn A.

    2008-01-01

    Meconium analysis can detect fetal exposure to drugs taken by the mother during pregnancy. Methamphetamine and amphetamine have previously been observed in meconium of methamphetamine-exposed neonates; the presence of other metabolites has not been investigated. Detection of such analytes may lead to more sensitive identification and, thus improved medical treatment of affected infants. Methods and Materials Forty-three methamphetamine-positive meconium specimens were analyzed for newly identified methamphetamine biomarkers, p-hydroxymethamphetamine, p-hydroxyamphetamine, and norephedrine. Due to methamphetamine adulteration in illicit ecstasy and to simultaneously monitor 3,4-methylenedioxymethamphetamine (MDMA) and methamphetamine prenatal exposure, MDMA, its metabolites and related sympathomimetic amines were assayed. Results Methamphetamine, amphetamine and unconjugated p-hydroxymethamphetamine were the most prevalent and abundant analytes present in meconium; however, unconjugated p-hydroxyamphetamine and norephedrine also were identified. Discussion It is possible that one of these additional analytes could be important for predicting toxicity or maternal or neonatal outcome measures in fetuses exposed to methamphetamine at specific gestational ages or with different metabolic capabilities. Although these new biomarkers were present in lower concentrations than methamphetamine and amphetamine in the meconium of previously confirmed specimens, additional research will determine if inclusion of these analytes can increase identification of methamphetamine-exposed neonates. Conclusion Novel methamphetamine biomarker concentrations were characterized in meconium of infants exposed in utero to methamphetamine. PMID:19125148

  10. Acute paretic syndrome in juvenile White Leghorn chickens resembles late stages of acute inflammatory demyelinating polyneuropathies in humans

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    Preisinger Rudolf

    2010-01-01

    Full Text Available Abstract Background Sudden limb paresis is a common problem in White Leghorn flocks, affecting about 1% of the chicken population before achievement of sexual maturity. Previously, a similar clinical syndrome has been reported as being caused by inflammatory demyelination of peripheral nerve fibres. Here, we investigated in detail the immunopathology of this paretic syndrome and its possible resemblance to human neuropathies. Methods Neurologically affected chickens and control animals from one single flock underwent clinical and neuropathological examination. Peripheral nervous system (PNS alterations were characterised using standard morphological techniques, including nerve fibre teasing and transmission electron microscopy. Infiltrating cells were phenotyped immunohistologically and quantified by flow cytometry. The cytokine expression pattern was assessed by quantitative real-time PCR (qRT-PCR. These investigations were accomplished by MHC genotyping and a PCR screen for Marek's disease virus (MDV. Results Spontaneous paresis of White Leghorns is caused by cell-mediated, inflammatory demyelination affecting multiple cranial and spinal nerves and nerve roots with a proximodistal tapering. Clinical manifestation coincides with the employment of humoral immune mechanisms, enrolling plasma cell recruitment, deposition of myelin-bound IgG and antibody-dependent macrophageal myelin-stripping. Disease development was significantly linked to a 539 bp microsatellite in MHC locus LEI0258. An aetiological role for MDV was excluded. Conclusions The paretic phase of avian inflammatory demyelinating polyradiculoneuritis immunobiologically resembles the late-acute disease stages of human acute inflammatory demyelinating polyneuropathy, and is characterised by a Th1-to-Th2 shift.

  11. The effect of acute exercise on collagen turnover in human tendons

    DEFF Research Database (Denmark)

    Mørch, Lina Steinrud; Pingel, Jessica; Boesen, Mikael;

    2013-01-01

    Mechanical loading of human tendon stimulates collagen synthesis, but the relationship between acute loading responses and training status of the tendon is not clear. We tested the effect of prolonged load deprivation on the acute loading-induced collagen turnover in human tendons, by applying...... and compared to values obtained by 72-h post-exercise. Power Doppler was used to monitor alterations in intratendinous blood flow velocity of the Achilles tendon and MRI used to quantitate changes in tendon cross-section area. Acute loading resulted in an increased collagen synthesis 72 h after the run in both...... the contra-lateral leg was used habitually. Following the procedure both Achilles tendons and calf muscles were loaded with the same absolute load during a 1-h treadmill run. Tissue collagen turnover was measured by microdialysis performed post-immobilization but pre-exercise around both Achilles tendons...

  12. Effect of environmental exposure to mercury on the functioning of the human body

    Directory of Open Access Journals (Sweden)

    Maciej Cyran

    2013-09-01

    Full Text Available Mercury is classified as a heavy metal and thus is commonly referred to as a death metal due to its high toxicity. In the environment it occurs in metallic form or in combination with other compounds. Amidst the sources of exposure to mercury, the most important environmental sources are dental amalgam and mercury vapor from the production of chlorine which is the most important source of occupational exposure. Mercury is easily soluble in fats, so it penetrates through biological membranes. Both - acute and chronic mercury poisoning causes characteristic clinical symptoms. There are several connections between exposure to this metal and toxic effects on the nervous system, cardiovascular system, endocrine system and kidneys. Thus mercury damages the structure of many organs and impairs their function

  13. Probabilistic integrated risk assessment of human exposure risk to environmental bisphenol A pollution sources.

    Science.gov (United States)

    Fu, Keng-Yen; Cheng, Yi-Hsien; Chio, Chia-Pin; Liao, Chung-Min

    2016-10-01

    Environmental bisphenol A (BPA) exposure has been linked to a variety of adverse health effects such as developmental and reproductive issues. However, establishing a clear association between BPA and the likelihood of human health is complex yet fundamentally uncertain. The purpose of this study was to assess the potential exposure risks from environmental BPA among Chinese population based on five human health outcomes, namely immune response, uterotrophic assay, cardiovascular disease (CVD), diabetes, and behavior change. We addressed these health concerns by using a stochastic integrated risk assessment approach. The BPA dose-dependent likelihood of effects was reconstructed by a series of Hill models based on animal models or epidemiological data. We developed a physiologically based pharmacokinetic (PBPK) model that allows estimation of urinary BPA concentration from external exposures. Here we showed that the daily average exposure concentrations of BPA and urinary BPA estimates were consistent with the published data. We found that BPA exposures were less likely to pose significant risks for infants (0-1 year) and adults (male and female >20 years) with human long-term BPA susceptibility in relation to multiple exposure pathways, and for informing the public of the negligible magnitude of environmental BPA pollution impacts on human health.

  14. Gene expression signatures that predict radiation exposure in mice and humans.

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    Holly K Dressman

    2007-04-01

    Full Text Available BACKGROUND: The capacity to assess environmental inputs to biological phenotypes is limited by methods that can accurately and quantitatively measure these contributions. One such example can be seen in the context of exposure to ionizing radiation. METHODS AND FINDINGS: We have made use of gene expression analysis of peripheral blood (PB mononuclear cells to develop expression profiles that accurately reflect prior radiation exposure. We demonstrate that expression profiles can be developed that not only predict radiation exposure in mice but also distinguish the level of radiation exposure, ranging from 50 cGy to 1,000 cGy. Likewise, a molecular signature of radiation response developed solely from irradiated human patient samples can predict and distinguish irradiated human PB samples from nonirradiated samples with an accuracy of 90%, sensitivity of 85%, and specificity of 94%. We further demonstrate that a radiation profile developed in the mouse can correctly distinguish PB samples from irradiated and nonirradiated human patients with an accuracy of 77%, sensitivity of 82%, and specificity of 75%. Taken together, these data demonstrate that molecular profiles can be generated that are highly predictive of different levels of radiation exposure in mice and humans. CONCLUSIONS: We suggest that this approach, with additional refinement, could provide a method to assess the effects of various environmental inputs into biological phenotypes as well as providing a more practical application of a rapid molecular screening test for the diagnosis of radiation exposure.

  15. Effects of ozone exposure on lipid metabolism in human alveolar macrophages

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, M.; Madden, M.C.; Samet, J.M.; Koren, H.S.

    1991-01-01

    Alveolar macrophages (AM) store arachidonic acid (AA) which is esterified in cellular phospholipids until liberated by phospholipase A2 or C after exposure to inflammatory stimuli. Following release, there can be subsequent metabolism of AA into various potent, biological active mediators including prostaglandins and platelet activating factor (PAF). To examine the possibility that these mediators may account for some of the pathophysiologic alterations seen in the lung following O3 exposure, human AM were collected by bronchoalveolar lavage of normal subjects, plated into tissue culture dishes, and the adherent cells were incubated with 3H-AA or 3H-lysoPAF. Human AM exposed 1.0 ppm O3 for 2 hr released 65 + or - 12% more tritium, derived from 3H-AA, than paired air-exposed controls into media supernatants. In other studies using a similar O3 exposure protocol, there was also a significant increase in human AM PGE2 production (2.0 + or - 0.5 fold-increase above air-exposure values, p<0.01, n=17). In additional studies, using a similar O3 exposure protocol (1.0 ppm for 1 hr), there was also a significant increase in human AM PAF content (1.7 + or - 0.2 fold-increase above air-exposure values, p<0.02, n=5).

  16. Acute respiratory distress syndrome following cutaneous exposure to Lysol: a case report.

    Science.gov (United States)

    Liu, Y Y; Lu, C C; Perng, R P

    1999-12-01

    Lysol (mixed cresols) is a brand of popular detergent commonly used to disinfect toilets and floors in Taiwan. We report a patient with acute respiratory failure immediately following chemical burns caused by skin contact with Lysol solution. On admission, chest radiography showed bilateral diffuse pulmonary infiltrates and an arterial blood gas analysis disclosed hypoxemia refractory to a high concentration of oxygen by inhalation. Under the impression of acute respiratory distress syndrome, our patient was admitted to the intensive care unit for respiratory care. Poor clinical improvement was noted, despite aggressive respiratory therapy. High-dose steroid therapy (hydrocortisone 30 mg/kg/day) was administered from the seventh day after mechanical ventilation began and the ratio of arterial partial pressure of oxygen to fractional concentration of oxygen in inspired gas improved thereafter. The amount of steroid was gradually tapered to the maintenance dose and the patient was successfully weaned from the ventilator after a 93-day course of mechanical ventilation.

  17. Acute ethanol exposure increases the susceptibility of the donor hearts to ischemia/reperfusion injury after transplantation in rats.

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    Shiliang Li

    Full Text Available BACKGROUND: Many donor organs come from youths involved in alcohol-related accidental death. The use of cardiac allografts for transplantation from donors after acute poisoning is still under discussion while acute ethanol intoxication is associated with myocardial functional and morphological changes. The aims of this work were 1 to evaluate in rats the time-course cardiac effects of acute ethanol-exposure and 2 to explore how its abuse by donors might affect recipients in cardiac pump function after transplantation. METHODS: Rats received saline or ethanol (3.45 g/kg, ip. We evaluated both the mechanical and electrical aspects of cardiac function 1 h, 6 h or 24 h after injection. Plasma cardiac troponin-T and glucose-levels were measured and histological examination of the myocardium was performed. In addition, heart transplantation was performed, in which donors received ethanol 6 h or 24 h prior to explantation. Graft function was measured 1 h or 24 h after transplantation. Myocardial TBARS-concentration was measured; mRNA and protein expression was assessed by quantitative real-time PCR and Western blot, respectively. RESULTS: Ethanol administration resulted in decreased load-dependent (-34 ± 9% and load-independent (-33 ± 12% contractility parameters, LV end-diastolic pressure and elevated blood glucose levels at 1 h, which were reversed to the level of controls after 6 h and 24 h. In contrast to systolic dysfunction, active relaxation and passive stiffness are slowly recovered or sustained during 24 h. Moreover, troponin-T-levels were increased at 1 h, 6 h and 24 h after ethanol injection. ST-segment elevation (+47 ± 10%, elongated QT-interval (+38 ± 4%, enlarged cardiomyocyte, DNA-strand breaks, increased both mRNA and protein levels of superoxide dismutase-1, glutathione peroxydase-4, cytochrome-c-oxidase and metalloproteinase-9 were observed 24 h following ethanol-exposure. After heart transplantation, decreased myocardial

  18. Acute short-term dim light exposure can lower muscle strength endurance