WorldWideScience

Sample records for repeated test exposure

  1. Irritancy of antiseptics tested by repeated open exposures on the human skin, evaluated by non-invasive methods

    NARCIS (Netherlands)

    Tupker, RA; Schuur, J; Coenraads, PJ

    1997-01-01

    The aim of the study was to test the irritancy of 6 antiseptics in an open exposure model. The following agents were tested in their normal use concentrations using open exposures, 2x daily for 4 days in 20 subjects: chlorhexidine 4% (CH), chlorhexidine 0.5% in ethanol 70% (CE), ethanol 70% (ET),

  2. Mood and autonomic responses to repeated exposure to the Trier Social Stress Test for Groups (TSST-G).

    Science.gov (United States)

    Boesch, Maria; Sefidan, Sandra; Ehlert, Ulrike; Annen, Hubert; Wyss, Thomas; Steptoe, Andrew; La Marca, Roberto

    2014-05-01

    A group version of the Trier Social Stress Test (TSST-G) was introduced as a standardized, economic and efficient tool to induce a psychobiological stress response simultaneously in a group of subjects. The aim of the present study was to examine the efficacy of the TSST-G to repeatedly induce an affective and autonomic stress response while comparing two alternative protocols for the second examination. Healthy young male recruits participated twice in the TSST-G 10 weeks apart. In the first examination, the TSST-G consisted of a combination of mental arithmetic and a fake job interview (TSST-G-1st; n=294). For the second examination, mental arithmetic was combined with either (a) a defensive speech in response to a false shoplifting accusation (TSST-G-2nd-defence; n=105), or (b) a speech on a more neutral topic selected by the investigators (TSST-G-2nd-presentation; n=100). Affect ratings and salivary alpha-amylase (sAA) were determined immediately before and after the stress test, while heart rate (HR) and heart rate variability (HRV) were measured continuously. TSST-G-1st resulted in a significant increase of negative affect, HR, and sAA, and a significant decrease in positive affect and HRV. TSST-G-2nd, overall, resulted in a significant increase of HR and sAA (the latter only in response to TSST-G-2nd-defence) and a decrease in HRV, while no significant affect alterations were found. When comparing both, TSST-G-2nd-defence and -2nd-presentation, the former resulted in a stronger stress response with regard to HR and HRV. The findings reveal that the TSST-G is a useful protocol to repeatedly evoke an affective and autonomic stress response, while repetition leads to affective but not necessarily autonomic habituation. When interested in examining repeated psychosocial stress reactivity, a task that requires an ego-involving effort, such as a defensive speech, seems to be significantly superior to a task using an impersonal speech. Copyright © 2014 Elsevier

  3. Linear Synchronous Motor Repeatability Tests

    International Nuclear Information System (INIS)

    Ward, C.R.

    2002-01-01

    A cart system using linear synchronous motors was being considered for the Plutonium Immobilization Plant (PIP). One of the applications in the PIP was the movement of a stack of furnace trays, filled with the waste form (pucks) from a stacking/unstacking station to several bottom loaded furnaces. A system was ordered to perform this function in the PIP Ceramic Prototype Test Facility (CPTF). This system was installed and started up in SRTC prior to being installed in the CPTF. The PIP was suspended and then canceled after the linear synchronous motor system was started up. This system was used to determine repeatability of a linear synchronous motor cart system for the Modern Pit Facility

  4. Toxicological characteristics of petroleum products repeated exposure

    Directory of Open Access Journals (Sweden)

    V.M. Rubin

    2015-03-01

    Full Text Available Abstract. The ability of petroleum products to initiate cumulative effects was assessed in experimental intragastric admission to male albino rats for one month. The analysis of skin-resorptive effects was performed using "test-tube" method on the skin of rats’ tails. It has been established that petroleum products can penetrate the intact skin and, with repeated admission, cause a general toxic effect. There were reductions bodyweights, the negative effect on the function of the kidneys and liver, changes of hematological parameters, as well as activation of the antioksidatnoy system. Repeated intragastric administration does not lead to the death of the animals testifying to the lack of accumulation capacity for petroleum products at the level of functional mortal effects, the cumulation coefficient being > 5.1. Negative impact on urinary function and hepatobiliary system, changes in hematological parameters and activation of the «lipid peroxidation – antioksidant defense» were observed.

  5. Repeated exposure to corticosterone increases depression-like behavior in two different versions of the forced swim test without altering nonspecific locomotor activity or muscle strength.

    Science.gov (United States)

    Marks, Wendie; Fournier, Neil M; Kalynchuk, Lisa E

    2009-08-04

    We have recently shown that repeated high dose injections of corticosterone (CORT) reliably increase depression-like behavior on a modified one-day version of the forced swim test. The main purpose of this experiment was to compare the effect of these CORT injections on our one-day version of the forced swim test and the more traditional two-day version of the test. A second purpose was to determine whether altered behavior in the forced swim test could be due to nonspecific changes in locomotor activity or muscle strength. Separate groups of rats received a high dose CORT injection (40 mg/kg) or a vehicle injection once per day for 21 consecutive days. Then, half the rats from each group were exposed to the traditional two-day forced swim test and the other half were exposed to our one-day forced swim test. After the forced swim testing, all the rats were tested in an open field and in a wire suspension grip strength test. The CORT injections significantly increased the time spent immobile and decreased the time spent swimming in both versions of the forced swim test. However, they had no significant effect on activity in the open field or grip strength in the wire suspension test. These results show that repeated CORT injections increase depression-like behavior regardless of the specific parameters of forced swim testing, and that these effects are independent of changes in locomotor activity or muscle strength.

  6. Increasing Positive Perceptions of Counseling: The Importance of Repeated Exposures

    Science.gov (United States)

    Kaplan, Scott A.; Vogel, David L.; Gentile, Douglas A.; Wade, Nathaniel G.

    2012-01-01

    This study assesses the effectiveness of repeated exposures to a video intervention based on the Elaboration Likelihood Model. The video was designed to increase help-seeking attitudes and perceptions of peer norms and to decrease the stigma associated with seeking counseling. Participants were 290 undergraduates who were randomly assigned to a…

  7. The effects of repeated low-dose sarin exposure

    International Nuclear Information System (INIS)

    Shih, T.-M.; Hulet, S.W.; McDonough, J.H.

    2006-01-01

    This project assessed the effects of repeated low-dose exposure of guinea pigs to the organophosphorus nerve agent sarin. Animals were injected once a day, 5 days per week (Monday-Friday), for 2 weeks with fractions (0.3x, 0.4x, 0.5x, or 0.6x) of the established LD 5 dose of sarin (42 μg/kg, s.c.). The animals were assessed for changes in body weight, red blood cell (RBC) acetylcholinesterase (AChE) levels, neurobehavioral reactions to a functional observational battery (FOB), cortical electroencephalographic (EEG) power spectrum, and intrinsic acetylcholine (ACh) neurotransmitter (NT) regulation over the 2 weeks of sarin exposure and for up to 12 days postinjection. No guinea pig receiving 0.3, 0.4 or 0.5 x LD 5 of sarin showed signs of cortical EEG seizures despite decreases in RBC AChE levels to as low as 10% of baseline, while seizures were evident in animals receiving 0.6 x LD 5 of sarin as early as the second day; subsequent injections led to incapacitation and death. Animals receiving 0.5 x LD 5 sarin showed obvious signs of cholinergic toxicity; overall, 2 of 13 animals receiving 0.5 x LD 5 sarin died before all 10 injections were given, and there was a significant increase in the angle of gait in the animals that lived. By the 10th day of injection, the animals receiving saline were significantly easier to remove from their cages and handle and significantly less responsive to an approaching pencil and touch on the rump in comparison with the first day of testing. In contrast, the animals receiving 0.4 x LD 5 sarin failed to show any significant reductions in their responses to an approaching pencil and a touch on the rump as compared with the first day. The 0.5 x LD 5 sarin animals also failed to show any significant changes to the approach and touch responses and did not adjust to handling or removal from the cage from the first day of injections to the last day of handling. Thus, the guinea pigs receiving the 0.4 and 0.5 x LD 5 doses of sarin failed to

  8. Consumer acceptance of salt-reduced 'soy sauce' foods over rapidly repeated exposure

    NARCIS (Netherlands)

    Kremer, S.; Shimojo, R.; Holthuysen, N.T.E.; Köster, E.P.; Mojet, J.

    2013-01-01

    The stability of the liking for salt reduced products was tested in a rapidly repeated exposure study using soup and bread (with ham). Salt was partially replaced by naturally brewed soy sauce. First, 44 consumers performed 5 two-alternative forced choice tests to establish the exchange rate (ER) at

  9. Absence of bacterial resistance following repeat exposure to photodynamic therapy

    Science.gov (United States)

    Pedigo, Lisa A.; Gibbs, Aaron J.; Scott, Robert J.; Street, Cale N.

    2009-06-01

    The prevalence of antibiotic resistant bacteria necessitates exploration of alternative approaches to treat hospital and community acquired infections. The aim of this study was to determine whether bacterial pathogens develop resistance to antimicrobial photodynamic therapy (aPDT) during repeated sub-lethal challenge. Antibiotic sensitive and resistant strains of S. aureus and antibiotic sensitive E. coli were subjected to repeat PDT treatments using a methylene blue photosensitizer formulation and 670 nm illumination from a non-thermal diode laser. Parameters were adjusted such that kills were antibiotic resistance strains. Furthermore, repeated sub-lethal exposure does not induce resistance to subsequent PDT treatments. The absence of resistance formation represents a significant advantage of PDT over traditional antibiotics.

  10. Effects of repeated skin exposure to low nickel concentrations

    DEFF Research Database (Denmark)

    Nielsen, N H; Menné, T; Kristiansen, J

    1999-01-01

    and nickel allergy, either on normal or on SLS-treated forearm skin. The present study strongly suggests that the changes observed were specific to nickel exposure. Standardized methods to assess trace to moderate nickel exposure on the hands, and the associated effects in nickel-sensitized subjects......We studied the effects of repeated daily exposure to low nickel concentrations on the hands of patients with hand eczema and nickel allergy. The concentrations used were chosen to represent the range of trace to moderate occupational nickel exposure. The study was double-blinded and placebo...... controlled. Patients immersed a finger for 10 min daily into a 10-p.p.m. nickel concentration in water for the first week, and during the second week into a 100-p.p.m. nickel concentration. This regimen significantly increased (P = 0.05) local vesicle formation and blood flow (P = 0.03) as compared...

  11. Behavioral sensitization after repeated formaldehyde exposure in rats.

    Science.gov (United States)

    Sorg, B A; Hochstatter, T

    1999-01-01

    Multiple chemical sensitivity (MCS) is a phenomenon whereby individuals report increased sensitivity to chemicals in the environment, and attribute their sensitivities to prior exposure to the same or often structurally unrelated chemicals. A leading hypothesis suggests that MCS is akin to behavioral sensitization observed in rodents after repeated exposure to drugs of abuse or environmental stressors. Sensitization occurring within limbic circuitry of the central nervous system (CNS) may explain the multisymptom complaints in individuals with MCS. The present studies represent the continuing development of an animal model for MCS, the basis of which is the CNS sensitization hypothesis. Three behaviors were assessed in rats repeatedly exposed to formaldehyde (Form) inhalation. In the first series of experiments, rats were given high-dose Form exposure (11 parts per million [ppm]; 1 h/day x 7 days) or low-dose Form exposure (1 ppm; either 1 h/day x 7 days or 1 h/day x 5 days/week x 4 weeks). Within a few days after discontinuing daily Form, cocaine-induced locomotor activity was elevated after high-dose Form or 20 days of low-dose Form inhalation. Approximately 1 month later, cocaine-induced locomotor activity remained significantly elevated in the 20-day Form-exposed rats. The second experiment assessed whether prior exposure to Form (20 days, as above) would alter the ability to condition to an odor (orange oil) paired with footshock. The results suggested a tendency to increase the conditioned fear response to the odor but not the context of the footshock box, and a decreased tendency to extinguish the conditioned fear response to odor. The third experiment examined whether CNS sensitization to daily cocaine or stress would alter subsequent avoidance responding to odor (Form). Daily cocaine significantly elevated approach responses to Form, while daily stress pretreatment produced a trend in the opposite direction, producing greater avoidance of Form. Preliminary

  12. Analysis of real-time mixture cytotoxicity data following repeated exposure using BK/TD models

    International Nuclear Information System (INIS)

    Teng, S.; Tebby, C.; Barcellini-Couget, S.; De Sousa, G.; Brochot, C.; Rahmani, R.; Pery, A.R.R.

    2016-01-01

    Cosmetic products generally consist of multiple ingredients. Thus, cosmetic risk assessment has to deal with mixture toxicity on a long-term scale which means it has to be assessed in the context of repeated exposure. Given that animal testing has been banned for cosmetics risk assessment, in vitro assays allowing long-term repeated exposure and adapted for in vitro – in vivo extrapolation need to be developed. However, most in vitro tests only assess short-term effects and consider static endpoints which hinder extrapolation to realistic human exposure scenarios where concentration in target organs is varies over time. Thanks to impedance metrics, real-time cell viability monitoring for repeated exposure has become possible. We recently constructed biokinetic/toxicodynamic models (BK/TD) to analyze such data (Teng et al., 2015) for three hepatotoxic cosmetic ingredients: coumarin, isoeugenol and benzophenone-2. In the present study, we aim to apply these models to analyze the dynamics of mixture impedance data using the concepts of concentration addition and independent action. Metabolic interactions between the mixture components were investigated, characterized and implemented in the models, as they impacted the actual cellular exposure. Indeed, cellular metabolism following mixture exposure induced a quick disappearance of the compounds from the exposure system. We showed that isoeugenol substantially decreased the metabolism of benzophenone-2, reducing the disappearance of this compound and enhancing its in vitro toxicity. Apart from this metabolic interaction, no mixtures showed any interaction, and all binary mixtures were successfully modeled by at least one model based on exposure to the individual compounds. - Highlights: • We could predict cell response over repeated exposure to mixtures of cosmetics. • Compounds acted independently on the cells. • Metabolic interactions impacted exposure concentrations to the compounds.

  13. Analysis of real-time mixture cytotoxicity data following repeated exposure using BK/TD models

    Energy Technology Data Exchange (ETDEWEB)

    Teng, S.; Tebby, C. [Models for Toxicology and Ecotoxicology Unit, INERIS, Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France); Barcellini-Couget, S. [ODESIA Neosciences, Sophia Antipolis, 400 route des chappes, 06903 Sophia Antipolis (France); De Sousa, G. [INRA, ToxAlim, 400 route des Chappes, BP, 167 06903 Sophia Antipolis, Cedex (France); Brochot, C. [Models for Toxicology and Ecotoxicology Unit, INERIS, Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France); Rahmani, R. [INRA, ToxAlim, 400 route des Chappes, BP, 167 06903 Sophia Antipolis, Cedex (France); Pery, A.R.R., E-mail: alexandre.pery@agroparistech.fr [AgroParisTech, UMR 1402 INRA-AgroParisTech Ecosys, 78850 Thiverval Grignon (France); INRA, UMR 1402 INRA-AgroParisTech Ecosys, 78850 Thiverval Grignon (France)

    2016-08-15

    Cosmetic products generally consist of multiple ingredients. Thus, cosmetic risk assessment has to deal with mixture toxicity on a long-term scale which means it has to be assessed in the context of repeated exposure. Given that animal testing has been banned for cosmetics risk assessment, in vitro assays allowing long-term repeated exposure and adapted for in vitro – in vivo extrapolation need to be developed. However, most in vitro tests only assess short-term effects and consider static endpoints which hinder extrapolation to realistic human exposure scenarios where concentration in target organs is varies over time. Thanks to impedance metrics, real-time cell viability monitoring for repeated exposure has become possible. We recently constructed biokinetic/toxicodynamic models (BK/TD) to analyze such data (Teng et al., 2015) for three hepatotoxic cosmetic ingredients: coumarin, isoeugenol and benzophenone-2. In the present study, we aim to apply these models to analyze the dynamics of mixture impedance data using the concepts of concentration addition and independent action. Metabolic interactions between the mixture components were investigated, characterized and implemented in the models, as they impacted the actual cellular exposure. Indeed, cellular metabolism following mixture exposure induced a quick disappearance of the compounds from the exposure system. We showed that isoeugenol substantially decreased the metabolism of benzophenone-2, reducing the disappearance of this compound and enhancing its in vitro toxicity. Apart from this metabolic interaction, no mixtures showed any interaction, and all binary mixtures were successfully modeled by at least one model based on exposure to the individual compounds. - Highlights: • We could predict cell response over repeated exposure to mixtures of cosmetics. • Compounds acted independently on the cells. • Metabolic interactions impacted exposure concentrations to the compounds.

  14. Firefighting and mental health: Experiences of repeated exposure to trauma.

    Science.gov (United States)

    Jahnke, Sara A; Poston, Walker S Carlos; Haddock, Christopher K; Murphy, Beth

    2016-02-15

    Firefighters must be ready to respond to a broad range of emergencies every duty day. In the course of many of these emergencies, firefighters witness events which have the potential to induce emotional trauma, such as badly injured people, deceased children, and individuals who are highly distraught. Previous research suggests that repeated exposure to these traumas (RET) may have negative impacts on the emotional and mental health of fire service personnel. Research on the mental health of firefighters has been limited to small surveys reporting the prevalence of specific mental health problems such as depression and post-traumatic stress disorder among firefighters. Despite the likelihood that RET leads to negative outcomes in firefighters, data is lacking on how exposure impacts fire service personnel. The current study examines the experiences of firefighters related to RET. Using formative research methods, we examined the beliefs and experiences of firefighters and administrators from across the United States regarding the impact of RET on firefighter health. Study findings highlight the cumulative psychological toll of repeated exposure to traumatic events including desensitization, flashbacks, and irritability. Results of the current study suggest that RET is a significant concern for emergency responders that warrants additional research and attention. It is likely that the long term consequences of RET are closely intertwined with other mental health outcomes and general well-being of this important occupational group.

  15. Attenuated response to repeated daily ozone exposures in asthmatic subjects

    Energy Technology Data Exchange (ETDEWEB)

    Gong, H. Jr.; Linn, W.S. [Rancho Low Amigos Medical Center, Downey, CA (United States); McManus, M.S. [Univ. of California, Los Angeles, CA (United States)

    1997-01-01

    The development of attenuated response ({open_quotes}tolerance{close_quotes}) to daily ozone (O{sub 3}) exposures in the laboratory is well established in healthy adult volunteers. However, the capability of asthmatics to develop tolerance during multiday ozone exposures in unclear. We exposed 10 adult volunteers with mild asthma to 0.4 ppm O{sub 3} in filtered air for 3 h/d on 5 consecutive d. Two similar filtered-air exposures during the preceding week served as controls. Follow-up O{sub 3} exposures were performed 4 and 7 d after the most recent consecutive exposure. All exposures were performed in an environmental chamber at 31 {degrees}C and 35% relative humidity. The subjects performed moderate exercise (mean ventilation rate of 32 l/min) for 15 min of each half-hour. Responses were measured with spirometry and symptom evaluations before and after each exposure, and a bronchial reactivity test (methacholine challenge) was conducted after each exposure. All response measurements showed clinically and statistically significant day-to-day variation. Symptom and forced-expiratory-volume-in-1-s responses were similarly large on the 1st and 2nd O{sub 3} exposure days, after which they diminished progressively, approaching filtered air response levels by the 5th consecutive O{sub 3} day. This tolerance was partially lost 4 and 7 d later. Bronchial reactivity peaked after the first O{sub 3} exposure and remained somewhat elevated after all subsequent O{sub 3} exposures, relative to its control level following filtered-air exposures. Individual responses varied widely; more severe initial responses to O{sub 3} predicted less rapid attenuation. We concluded that asthmatics can develop tolerance to frequent high-level O{sub 3} exposures in much the same manner as normal subjects, although the process may be slower and less fully effective in asthmatics. 27 refs., 3 figs., 4 tabs.

  16. Repeatability study of replicate crash tests: A signal analysis approach.

    Science.gov (United States)

    Seppi, Jeremy; Toczyski, Jacek; Crandall, Jeff R; Kerrigan, Jason

    2017-10-03

    To provide an objective basis on which to evaluate the repeatability of vehicle crash test methods, a recently developed signal analysis method was used to evaluate correlation of sensor time history data between replicate vehicle crash tests. The goal of this study was to evaluate the repeatability of rollover crash tests performed with the Dynamic Rollover Test System (DRoTS) relative to other vehicle crash test methods. Test data from DRoTS tests, deceleration rollover sled (DRS) tests, frontal crash tests, frontal offset crash tests, small overlap crash tests, small overlap impact (SOI) crash tests, and oblique crash tests were obtained from the literature and publicly available databases (the NHTSA vehicle database and the Insurance Institute for Highway Safety TechData) to examine crash test repeatability. Signal analysis of the DRoTS tests showed that force and deformation time histories had good to excellent repeatability, whereas vehicle kinematics showed only fair repeatability due to the vehicle mounting method for one pair of tests and slightly dissimilar mass properties (2.2%) in a second pair of tests. Relative to the DRS, the DRoTS tests showed very similar or higher levels of repeatability in nearly all vehicle kinematic data signals with the exception of global X' (road direction of travel) velocity and displacement due to the functionality of the DRoTS fixture. Based on the average overall scoring metric of the dominant acceleration, DRoTS was found to be as repeatable as all other crash tests analyzed. Vertical force measures showed good repeatability and were on par with frontal crash barrier forces. Dynamic deformation measures showed good to excellent repeatability as opposed to poor repeatability seen in SOI and oblique deformation measures. Using the signal analysis method as outlined in this article, the DRoTS was shown to have the same or better repeatability of crash test methods used in government regulatory and consumer evaluation test

  17. Analysis of real-time mixture cytotoxicity data following repeated exposure using BK/TD models.

    Science.gov (United States)

    Teng, S; Tebby, C; Barcellini-Couget, S; De Sousa, G; Brochot, C; Rahmani, R; Pery, A R R

    2016-08-15

    Cosmetic products generally consist of multiple ingredients. Thus, cosmetic risk assessment has to deal with mixture toxicity on a long-term scale which means it has to be assessed in the context of repeated exposure. Given that animal testing has been banned for cosmetics risk assessment, in vitro assays allowing long-term repeated exposure and adapted for in vitro - in vivo extrapolation need to be developed. However, most in vitro tests only assess short-term effects and consider static endpoints which hinder extrapolation to realistic human exposure scenarios where concentration in target organs is varies over time. Thanks to impedance metrics, real-time cell viability monitoring for repeated exposure has become possible. We recently constructed biokinetic/toxicodynamic models (BK/TD) to analyze such data (Teng et al., 2015) for three hepatotoxic cosmetic ingredients: coumarin, isoeugenol and benzophenone-2. In the present study, we aim to apply these models to analyze the dynamics of mixture impedance data using the concepts of concentration addition and independent action. Metabolic interactions between the mixture components were investigated, characterized and implemented in the models, as they impacted the actual cellular exposure. Indeed, cellular metabolism following mixture exposure induced a quick disappearance of the compounds from the exposure system. We showed that isoeugenol substantially decreased the metabolism of benzophenone-2, reducing the disappearance of this compound and enhancing its in vitro toxicity. Apart from this metabolic interaction, no mixtures showed any interaction, and all binary mixtures were successfully modeled by at least one model based on exposure to the individual compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Impact of Inclusion or Exclusion of Repeaters on Test Equating

    Science.gov (United States)

    Puhan, Gautam

    2011-01-01

    This study examined the effect of including or excluding repeaters on the equating process and results. New forms of two tests were equated to their respective old forms using either all examinees or only the first timer examinees in the new form sample. Results showed that for both tests used in this study, including or excluding repeaters in the…

  19. A study on the repeatability of ultrasonic testing data

    International Nuclear Information System (INIS)

    Yoshimura, Seiichi; Fukumoto, Hiroshi

    1980-01-01

    Reliability improvement of ultrasonic testing data is strongly desired in ultrasonic testing working of nuclear power plants. This paper deals with the problems of the testing by the manual and the remote control apparatus, and with the factors which influence the repeatability of ultrasonic testing data. Following results are found in it. (1) In the testing by the manual, working time and posture influence the repeatability of testing data. (2) Glycerin in suitable for the couplant in the respect of the repeatability of testing data. In the case of using machine oil, the pressure to the probe necessitates to be over 0.2 kg/cm 2 . (3) In the testing by the remote control apparatus, working time, working environment and defect position does not influence the repeatability of testing data. (author)

  20. Repeated isoflurane exposure and neuroapoptosis in the midgestation fetal sheep brain.

    Science.gov (United States)

    Olutoye, Olutoyin A; Sheikh, Fariha; Zamora, Irving J; Yu, Ling; Akinkuotu, Adesola C; Adesina, Adekunle M; Olutoye, Oluyinka O

    2016-04-01

    Advances in surgery and technology have resulted in increased in-utero procedures. However, the effect of anesthesia on the fetal brain is not fully known. The inhalational anesthetic agent, isoflurane, other gamma amino butyric acid agonists (benzodiazepines, barbiturates, propofol, other inhalation anesthetics), and N-methyl D aspartate antagonists, eg, ketamine, have been shown to induce neuroapoptosis. The ovine model has been used extensively to study maternal-fetal physiologic interactions and to investigate different surgical interventions on the fetus. The purpose of this study was to determine effects of different doses and duration of isoflurane on neuroapoptosis in midgestation fetal sheep. We hypothesized that repeated anesthetic exposure and high concentrations of isoflurane would result in increased neuroapoptosis. Time-dated, pregnant sheep at 70 days gestation (term 145 days) received either isoflurane 2% × 1 hour, 4% × 3 hours, or 2% × 1 hour every other day for 3 exposures (repeated exposure group). Euthanasia occurred following anesthetic exposure and fetal brains were processed. Neuroapoptosis was detected by immunohistochemistry using anticaspase-3 antibodies. Fetuses unexposed to anesthesia served as controls. Another midgestation group with repeated 2% isoflurane exposure was examined at day 130 (long-term group) and neuronal cell density compared to age-matched controls. Representative sections of the brain were analyzed using Aperio Digital imaging (Leica Microsystems Inc, Buffalo Grove, IL). Data, reported by number of neurons per cubic millimeter of brain tissue are presented as means and SEM. Data were analyzed using the Mann-Whitney U and Kruskal-Wallis tests as appropriate. A total of 34 fetuses were studied. There was no significant difference in neuroapoptosis observed in fetuses exposed to 2% isoflurane for 1 hour or 4% isoflurane for 3 hours. Increased neuroapoptosis was observed in the frontal cortex following repeated 2

  1. The role of temporal delay and repeated prospective memory cue exposure on the deactivation of completed intentions.

    Science.gov (United States)

    Walser, Moritz; Plessow, Franziska; Goschke, Thomas; Fischer, Rico

    2014-07-01

    Previous studies have shown that completed prospective memory (PM) intentions entail aftereffects in terms of ongoing-task-performance decrements in trials containing repeated PM cues which previously served as PM cues triggering the intended action. Previous research reported that PM aftereffects decrease over time, thus revealing a specific time course of PM aftereffects. In the present study, we tested two accounts for this pattern, assuming either that the decline of aftereffects is related to the temporal distance to PM task completion or may be a result of the repeated exposure of repeated PM cues in the ongoing task. In three experiments, we manipulated both the temporal distance to PM task completion and the frequency of repeated PM cues and demonstrated that aftereffects of completed intentions declined with repeated exposure of formerly relevant PM cues. In addition, effects of repeated exposure were not only limited to the repetition of specific PM-cue exemplars but also generalized to other semantically related PM cues within the PM-cue category. Together, findings show that decreased aftereffects of completed intentions are not related to the temporal duration of the subsequent test block, but crucially depend on the repeated exposure of the previously relevant PM cues.

  2. Repeated Exposure to Conditioned Fear Stress Increases Anxiety and Delays Sleep Recovery Following Exposure to an Acute Traumatic Stressor

    OpenAIRE

    Greenwood, Benjamin N.; Thompson, Robert S.; Opp, Mark R.; Fleshner, Monika

    2014-01-01

    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 human beings, but whether exposure to repeated fear can prime the develo...

  3. The Effects of Repeated Exposure to Graphic Fear Appeals on Cigarette Packages: A Field Experiment

    NARCIS (Netherlands)

    Dijkstra, A.; Bos, C.

    2015-01-01

    Experimental studies on the effects of graphic fear appeals on cigarette packages typically expose smokers in a single session to a fear appeal, although in practice the exposure is always repeated. The present study applied an improved study design with repeated exposure to fear appeals on

  4. The Effects of Repeated Exposure to Graphic Fear Appeals on Cigarette Packages : A Field Experiment

    NARCIS (Netherlands)

    Dijkstra, Arie; Colin, Bos,

    2015-01-01

    Experimental studies on the effects of graphic fear appeals on cigarette packages typically expose smokers in a single session to a fear appeal, although in practice the exposure is always repeated. The present study applied an improved study design with repeated exposure to fear appeals on

  5. Dealing with consumer differences in liking during repeated exposure to food; typical dynamics in rating behavior

    NARCIS (Netherlands)

    Horst, ter G.J.; Renken, R.; Nanneti, L.; Dalenberg, J.R.; Wijk, de R.A.

    2014-01-01

    Consumers show high interindividual variability in food liking during repeated exposure. To investigate consumer liking during repeated exposure, data is often interpreted on a product level by averaging results over all consumers. However, a single product may elicit inconsistent behaviors in

  6. Dealing with Consumer Differences in Liking during Repeated Exposure to Food; Typical Dynamics in Rating Behavior

    NARCIS (Netherlands)

    Dalenberg, Jelle R.; Nanetti, Luca; Renken, Remco J.; de Wijk, Rene A.; ter Horst, Gert J.

    2014-01-01

    Consumers show high interindividual variability in food liking during repeated exposure. To investigate consumer liking during repeated exposure, data is often interpreted on a product level by averaging results over all consumers. However, a single product may elicit inconsistent behaviors in

  7. Irritancy ranking of anionic detergents using one-time occlusive, repeated occlusive and repeated open tests

    NARCIS (Netherlands)

    Tupker, RA; Bunte, EE; Fidler, [No Value; Wiechers, JW; Coenraads, PJ

    Discrepancies between the one-time patch test and the wash test regarding the ranking of irritancy of detergents have been found in the literature. The aim of the present study was to investigate the concordance of irritancy rank order of 4 anionic detergents tested by 3 different exposure methods,

  8. Consequences of repeated ethanol exposure during early or late adolescence on conditioned taste aversions in rats

    Directory of Open Access Journals (Sweden)

    Jessica Saalfield

    2015-12-01

    Full Text Available Alcohol use is prevalent during adolescence, yet little is known about possible long-lasting consequences. Recent evidence suggests that adolescents are less sensitive than adults to ethanol's aversive effects, an insensitivity that may be retained into adulthood after repeated adolescent ethanol exposure. This study assessed whether intermittent ethanol exposure during early or late adolescence (early-AIE or late-AIE, respectively would affect ethanol conditioned taste aversions 2 days (CTA1 and >3 weeks (CTA2 post-exposure using supersaccharin and saline as conditioning stimuli (CS, respectively. Pair-housed male Sprague-Dawley rats received 4 g/kg i.g. ethanol (25% or water every 48 h from postnatal day (P 25–45 (early AIE or P45-65 (late AIE, or were left non-manipulated (NM. During conditioning, 30 min home cage access to the CS was followed by 0, 1, 1.5, 2 or 2.5 g/kg ethanol i.p., with testing 2 days later. Attenuated CTA relative to controls was seen among early and late AIE animals at both CTA1 and CTA2, an effect particularly pronounced at CTA1 after late AIE. Thus, adolescent exposure to ethanol was found to induce an insensitivity to ethanol CTA seen soon after exposure and lasting into adulthood, and evident with ethanol exposures not only early but also later in adolescence.

  9. Consequences of repeated ethanol exposure during early or late adolescence on conditioned taste aversions in rats.

    Science.gov (United States)

    Saalfield, Jessica; Spear, Linda

    2015-12-01

    Alcohol use is prevalent during adolescence, yet little is known about possible long-lasting consequences. Recent evidence suggests that adolescents are less sensitive than adults to ethanol's aversive effects, an insensitivity that may be retained into adulthood after repeated adolescent ethanol exposure. This study assessed whether intermittent ethanol exposure during early or late adolescence (early-AIE or late-AIE, respectively) would affect ethanol conditioned taste aversions 2 days (CTA1) and >3 weeks (CTA2) post-exposure using supersaccharin and saline as conditioning stimuli (CS), respectively. Pair-housed male Sprague-Dawley rats received 4g/kg i.g. ethanol (25%) or water every 48 h from postnatal day (P) 25-45 (early AIE) or P45-65 (late AIE), or were left non-manipulated (NM). During conditioning, 30 min home cage access to the CS was followed by 0, 1, 1.5, 2 or 2.5g/kg ethanol i.p., with testing 2 days later. Attenuated CTA relative to controls was seen among early and late AIE animals at both CTA1 and CTA2, an effect particularly pronounced at CTA1 after late AIE. Thus, adolescent exposure to ethanol was found to induce an insensitivity to ethanol CTA seen soon after exposure and lasting into adulthood, and evident with ethanol exposures not only early but also later in adolescence. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Dealing with consumer differences in liking during repeated exposure to food; typical dynamics in rating behavior.

    Science.gov (United States)

    Dalenberg, Jelle R; Nanetti, Luca; Renken, Remco J; de Wijk, René A; Ter Horst, Gert J

    2014-01-01

    Consumers show high interindividual variability in food liking during repeated exposure. To investigate consumer liking during repeated exposure, data is often interpreted on a product level by averaging results over all consumers. However, a single product may elicit inconsistent behaviors in consumers; averaging will mix and hide possible subgroups of consumer behaviors, leading to a misinterpretation of the results. To deal with the variability in consumer liking, we propose to use clustering on data from consumer-product combinations to investigate the nature of the behavioral differences within the complete dataset. The resulting behavioral clusters can then be used to describe product acceptance. To test this approach we used two independent data sets in which young adults were repeatedly exposed to drinks and snacks, respectively. We found that five typical consumer behaviors existed in both datasets. These behaviors differed both in the average level of liking as well as its temporal dynamics. By investigating the distribution of a single product across typical consumer behaviors, we provide more precise insight in how consumers divide in subgroups based on their product liking (i.e. product modality). This work shows that taking into account and using interindividual differences can unveil information about product acceptance that would otherwise be ignored.

  11. Repeated cocaine exposure facilitates the expression of incentive motivation and induces habitual control in rats.

    Directory of Open Access Journals (Sweden)

    Kimberly H LeBlanc

    Full Text Available There is growing evidence that mere exposure to drugs can induce long-term alterations in the neural systems that mediate reward processing, motivation, and behavioral control, potentially causing the pathological pursuit of drugs that characterizes the addicted state. The incentive sensitization theory proposes that drug exposure potentiates the influence of reward-paired cues on behavior. It has also been suggested that drug exposure biases action selection towards the automatic execution of habits and away from more deliberate goal-directed control. The current study investigated whether rats given repeated exposure to peripherally administered cocaine would show alterations in incentive motivation (assayed using the Pavlovian-to-instrumental transfer (PIT paradigm or habit formation (assayed using sensitivity to reward devaluation. After instrumental and Pavlovian training for food pellet rewards, rats were given 6 daily injections of cocaine (15 mg/kg, IP or saline, followed by a 10-d period of rest. Consistent with the incentive sensitization theory, cocaine-treated rats showed stronger cue-evoked lever pressing than saline-treated rats during the PIT test. The same rats were then trained on a new instrumental action with a new food pellet reward before undergoing a reward devaluation testing. Although saline-treated rats exhibited sensitivity to reward devaluation, indicative of goal-directed performance, cocaine-treated rats were insensitive to this treatment, suggesting a reliance on habitual processes. These findings, when taken together, indicate that repeated exposure to cocaine can cause broad alterations in behavioral control, spanning both motivational and action selection processes, and could therefore help explain aberrations of decision-making that underlie drug addiction.

  12. Repeated cocaine exposure facilitates the expression of incentive motivation and induces habitual control in rats.

    Science.gov (United States)

    LeBlanc, Kimberly H; Maidment, Nigel T; Ostlund, Sean B

    2013-01-01

    There is growing evidence that mere exposure to drugs can induce long-term alterations in the neural systems that mediate reward processing, motivation, and behavioral control, potentially causing the pathological pursuit of drugs that characterizes the addicted state. The incentive sensitization theory proposes that drug exposure potentiates the influence of reward-paired cues on behavior. It has also been suggested that drug exposure biases action selection towards the automatic execution of habits and away from more deliberate goal-directed control. The current study investigated whether rats given repeated exposure to peripherally administered cocaine would show alterations in incentive motivation (assayed using the Pavlovian-to-instrumental transfer (PIT) paradigm) or habit formation (assayed using sensitivity to reward devaluation). After instrumental and Pavlovian training for food pellet rewards, rats were given 6 daily injections of cocaine (15 mg/kg, IP) or saline, followed by a 10-d period of rest. Consistent with the incentive sensitization theory, cocaine-treated rats showed stronger cue-evoked lever pressing than saline-treated rats during the PIT test. The same rats were then trained on a new instrumental action with a new food pellet reward before undergoing a reward devaluation testing. Although saline-treated rats exhibited sensitivity to reward devaluation, indicative of goal-directed performance, cocaine-treated rats were insensitive to this treatment, suggesting a reliance on habitual processes. These findings, when taken together, indicate that repeated exposure to cocaine can cause broad alterations in behavioral control, spanning both motivational and action selection processes, and could therefore help explain aberrations of decision-making that underlie drug addiction.

  13. The effect of repeated testing vs repeated practice on skills learning in undergraduate dental education.

    Science.gov (United States)

    Sennhenn-Kirchner, S; Goerlich, Y; Kirchner, B; Notbohm, M; Schiekirka, S; Simmenroth, A; Raupach, T

    2018-02-01

    Recent studies in undergraduate medical education have demonstrated the advantage of repeated testing over repeated practice with regard to knowledge and skills retention. The aim of this study was to investigate whether this "testing effect" also applies to skills retention in undergraduate dental education. In this prospective, randomised controlled trial, fourth-year dental students at Göttingen University Medical Centre participated in a training session on surgical suturing in winter term 2014/2015. Following this, they were either assigned to two sessions of additional skills training (group A) or two sessions of skills assessment with feedback (group B). These sessions were spaced over a period of 4 weeks. Skills retention was assessed in a summative objective structured clinical examination (OSCE) at the end of term, that is 6 months after the initial teaching session. A total of 32 students completed the study. With regard to suturing, OSCE performance was significantly better in group B than group A (81.9±13.1% vs 63.0±15.4%; P=0.001; Cohen's d=1.33). There was no significant OSCE performance difference in the two groups with regard to other learning objectives that were addressed in the end-of-term examination. Thus, the group difference was specific to suturing skills. This is the first study to demonstrate that in dental education, repeated testing produces more favourable skills retention than repeated practice. Test-enhanced learning might be a viable concept for skills retention in undergraduate dentistry education. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. The effects of repeated low-level blast exposure on hearing in marines

    Directory of Open Access Journals (Sweden)

    Lina R Kubli

    2017-01-01

    Full Text Available Background: The study evaluates a group of Military Service Members specialized in blast explosive training called “Breachers” who are routinely exposed to multiple low-level blasts while teaching breaching at the U.S. Marine Corps in Quantico Virginia. The objective of this study was to determine if there are any acute or long-term auditory changes due to repeated low-level blast exposures used in training. The performance of the instructor group “Breachers” was compared to a control group, “Engineers”. Methods: A total of 11 Breachers and four engineers were evaluated in the study. The participants received comprehensive auditory tests, including pure-tone testing, speech-in-noise (SIN measures, and central auditory behavioral and objective tests using early and late (P300 auditory evoked potentials over a period of 17 months. They also received shorter assessments immediately following the blast-exposure onsite at Quantico. Results: No acute or longitudinal effects were identified. However, there were some interesting baseline effects found in both groups. Contrary to the expected, the onsite hearing thresholds and distortion product otoacoustic emissions were slightly better at a few frequencies immediately after blast-exposure than measurements obtained with the same equipment weeks to months after each blast-exposure. Conclusions: To date, the current study is the most comprehensive study that evaluates the long-term effects of blast-exposure on hearing. Despite extensive testing to assess changes, the findings of this study suggest that the levels of current exposures used in this military training environment do not seem to have an obvious deleterious effect on hearing.

  15. Eliminating the mere exposure effect through changes in context between exposure and test.

    Science.gov (United States)

    de Zilva, Daniel; Mitchell, Chris J; Newell, Ben R

    2013-01-01

    The present study examined the extent to which increased liking of exposed stimuli--the mere exposure effect--is dependent on experiencing the stimuli in the same context in exposure and on test. Participants were repeatedly exposed to pairs of cues (nonsense words) and target stimuli (faces and shapes), and were asked to rate the pleasantness of the target stimuli in a subsequent test phase. Familiar targets were preferred to novel targets-a mere exposure effect was obtained. This preference for familiar targets was disrupted, however, when the cue-target pairings were rearranged between exposure and test, or a novel cue was introduced at test. Overall, the study suggests that the context of exposure and test moderates the mere exposure effect. Liking of stimuli due to exposure is specific to the context of exposure and does not apply to new or familiar but different contexts.

  16. Repeated restraint stress exposure during early withdrawal accelerates incubation of cue-induced cocaine craving.

    Science.gov (United States)

    Glynn, Ryan M; Rosenkranz, J Amiel; Wolf, Marina E; Caccamise, Aaron; Shroff, Freya; Smith, Alyssa B; Loweth, Jessica A

    2018-01-01

    A major challenge for treating cocaine addiction is the propensity for abstinent users to relapse. Two important triggers for relapse are cues associated with prior drug use and stressful life events. To study their interaction in promoting relapse during abstinence, we used the incubation model of craving and relapse in which cue-induced drug seeking progressively intensifies ('incubates') during withdrawal from extended-access cocaine self-administration. We tested rats for cue-induced cocaine seeking on withdrawal day (WD) 1. Rats were then subjected to repeated restraint stress or control conditions (seven sessions held between WD6 and WD14). All rats were tested again for cue-induced cocaine seeking on WD15, 1 day after the last stress or control session. Although controls showed a time-dependent increase in cue-induced cocaine seeking (incubation), rats exposed to repeated stress in early withdrawal exhibited a more robust increase in seeking behavior between WD1 and WD15. In separate stressed and control rats, equivalent cocaine seeking was observed on WD48. These results indicate that repeated stress in early withdrawal accelerates incubation of cocaine craving, although craving plateaus at the same level were observed in controls. However, 1 month after the WD48 test, rats subjected to repeated stress in early withdrawal showed enhanced cue-induced cocaine seeking following acute (24 hours) food deprivation stress. Together, these data indicate that chronic stress exposure enhances the initial rate of incubation of craving during early withdrawal, resulting in increased vulnerability to cue-induced relapse during this period, and may lead to a persistent increase in vulnerability to the relapse-promoting effects of stress. © 2016 Society for the Study of Addiction.

  17. 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.

  18. Repeated inhalation exposure of Beagle dogs to aerosols of 239PuO2. XII

    International Nuclear Information System (INIS)

    Diel, J.H.; Hahn, F.F.; Muggenburg, B.A.

    1988-01-01

    Beagle dogs were exposed once or semi-annually for 10 yr by inhalation to aerosols of 239 PuO 2 to study the relative doses and effects of these two types of exposures. All exposures have been completed. Dogs exposed at high levels died predominantly of radiation pneumonitis and pulmonary fibrosis. Dogs exposed at lower levels, either once or repeatedly, are dying of a variety of causes including lung cancer. Dogs have survived up to 11 yr after their first exposure. Preliminary results suggest that single and repeated exposures cause similar health effects for equal accumulated radiation doses. (author)

  19. Neonates' responses to repeated exposure to a still face.

    Science.gov (United States)

    Nagy, Emese; Pilling, Karen; Watt, Rachel; Pal, Attila; Orvos, Hajnalka

    2017-01-01

    The main aims of the study were to examine whether human neonates' responses to communication disturbance modelled by the still-face paradigm were stable and whether their responses were affected by their previous experience with the still-face paradigm. The still face procedure, as a laboratory model of interpersonal stress, was administered repeatedly, twice, to 84 neonates (0 to 4 day olds), with a delay of an average of 1.25 day. Frame-by-frame analysis of the frequency and duration of gaze, distressed face, crying, sleeping and sucking behaviours showed that the procedure was stressful to them both times, that is, the still face effect was stable after repeated administration and newborns consistently responded to such nonverbal violation of communication. They averted their gaze, showed distress and cried more during the still-face phase in both the first and the second administration. They also showed a carry-over effect in that they continued to avert their gaze and displayed increased distress and crying in the first reunion period, but their gaze behaviour changed with experience, in the second administration. While in the first administration the babies continued averting their gaze even after the stressful still-face phase was over, this carry-over effect disappeared in the second administration, and the babies significantly increased their gaze following the still-face phase. After excluding explanations of fatigue, habituation and random effects, a self-other regulatory model is discussed as a possible explanation for this pattern.

  20. Neonates’ responses to repeated exposure to a still face

    Science.gov (United States)

    Pilling, Karen; Watt, Rachel; Pal, Attila; Orvos, Hajnalka

    2017-01-01

    Aim The main aims of the study were to examine whether human neonates’ responses to communication disturbance modelled by the still-face paradigm were stable and whether their responses were affected by their previous experience with the still-face paradigm. Methods The still face procedure, as a laboratory model of interpersonal stress, was administered repeatedly, twice, to 84 neonates (0 to 4 day olds), with a delay of an average of 1.25 day. Results Frame-by-frame analysis of the frequency and duration of gaze, distressed face, crying, sleeping and sucking behaviours showed that the procedure was stressful to them both times, that is, the still face effect was stable after repeated administration and newborns consistently responded to such nonverbal violation of communication. They averted their gaze, showed distress and cried more during the still-face phase in both the first and the second administration. They also showed a carry-over effect in that they continued to avert their gaze and displayed increased distress and crying in the first reunion period, but their gaze behaviour changed with experience, in the second administration. While in the first administration the babies continued averting their gaze even after the stressful still-face phase was over, this carry-over effect disappeared in the second administration, and the babies significantly increased their gaze following the still-face phase. Conclusion After excluding explanations of fatigue, habituation and random effects, a self-other regulatory model is discussed as a possible explanation for this pattern. PMID:28771555

  1. Tumorigenic responses from single or repeated inhalation exposures to relatively insoluble aerosols of Ce-144

    International Nuclear Information System (INIS)

    Boecker, B.B.; Hahn, F.F.; Mauderly, J.L.; McClellan, R.O.

    1980-01-01

    Human occupational or environmental inhalation exposures may involve repeated or chronic exposures, but most laboratory studies of inhaled radionuclides have involved single exposures. This study was designed to compare the biological effects of repeated inhalation exposures of dogs to a relatively insoluble form of 144 Ce with existing data for singly-exposed dogs that had the same cumulative dose to the lungs two years after exposure. To date, the biological effects observed in these repeatedly-exposed dogs have been substantially different from those seen in singly-exposed dogs, particularly during the first 5 years after the initial exposure. Although pulmonary hemangiosarcoma was the prominent biological effect seen in singly-exposed dogs between 2 and 4 years after exposure, no lung tumors were seen during the 5 years after the first of the repeated exposures. This response plus other clinical observations are discussed in relation to the patterns of dose rate and cumulative dose for the different exposure conditions. (H.K.)

  2. The Effects of Repeated Low-Dose Sarin Exposure

    Science.gov (United States)

    2005-08-01

    support the idea that there is a triphasic NT model for onset and progression of seizures and subsequent brain damage upon acute exposure to OP ChE...An ACh microbore column (1x530 mm ID, 10 µm UniJet, BAS #MF-8904) coupled with AChE/choline oxidase immobilized enzyme reactor (BAS # MF-8903) was...peroxidase to the electrode for the reduction of hydrogen peroxide that was generated from the immobilized enzyme reactor . The detector was set at (-)1.0

  3. Repeated cue exposure effects on subjective and physiological indices of chocolate craving

    NARCIS (Netherlands)

    van Gucht, D.; Vansteenwegen, D.; Beckers, T.; Hermans, D.; Baeyens, F.; Van den Bergh, O.

    2008-01-01

    The aim of this study is to investigate the effects of repeated unreinforced exposure to chocolate cues in persons reporting chocolate craving. Participants in the experimental group (n ¼ 40) received 10 consecutive brief exposures to chocolate cues in each of two sessions, separated by 1-3 days.

  4. The rise in carboxyhemoglobin from repeated pulmonary diffusing capacity tests.

    Science.gov (United States)

    Zavorsky, Gerald S

    2013-03-01

    The purpose of this study determined the rise in carboxyhemoglobin percentage (COHb) from repeated pulmonary diffusing capacity tests using 5 or 10s single breath-hold maneuvers. Five male and four female non-smokers [baseline COHb=1.2 (SD 0.5%)] performed repeated pulmonary diffusing capacity testing on two separate days. The days were randomized to either repeated 10s (0.28% CO), or 5s (0.28% CO, 55ppm NO) breath-hold maneuvers. Twenty-two 5s breath-hold maneuvers, each separated by 4min rest, raised COHb to 11.1 (1.4)% and minimally raised the methemoglobin percentage (METHb) by 0.3 (0.2)% to a value of 0.8 (0.2)%. After the 22nd test, pulmonary diffusing capacity for carbon monoxide (DLCO) was reduced by about 4mL/min/mmHg, equating to a 0.44% increase in COHb per 5s breath-hold maneuver and a concomitant 0.35mL/min/mmHg decrease in DLCO. Pulmonary diffusing capacity for nitric oxide (DLNO) was not altered after 22 tests. On another day, the 10s single breath-hold maneuver increased COHb by 0.64% per test, and reduced DLCO by 0.44mL/min/mmHg per test. In conclusion, 5s breath-hold maneuvers do not appreciably raise METHb or DLNO, and DLCO is only significantly reduced when COHb is at least 6%. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Repeated cue exposure effects on subjective and physiological indices of chocolate craving

    OpenAIRE

    Van Gucht, Dinska; Vansteenwegen, Debora; Beckers, Tom; Hermans, Dirk; Baeyens, Frank; Van den Bergh, Omer

    2008-01-01

    The aim of this study is to investigate the effects of repeated unreinforced exposure to chocolate cues in persons reporting chocolate craving. Participants in the experimental group (n=40) received 10 consecutive brief exposures to chocolate cues in each of two sessions, separated by 1-3 days. Control participants (n=18) received two exposures at the start and end of each session. Chocolate craving was measured (alternately) through subjective report and the amount of saliva secretion to cho...

  6. The Role of Repeated Exposure to Multimodal Input in Incidental Acquisition of Foreign Language Vocabulary.

    Science.gov (United States)

    Bisson, Marie-Josée; van Heuven, Walter J B; Conklin, Kathy; Tunney, Richard J

    2014-12-01

    Prior research has reported incidental vocabulary acquisition with complete beginners in a foreign language (FL), within 8 exposures to auditory and written FL word forms presented with a picture depicting their meaning. However, important questions remain about whether acquisition occurs with fewer exposures to FL words in a multimodal situation and whether there is a repeated exposure effect. Here we report a study where the number of exposures to FL words in an incidental learning phase varied between 2, 4, 6, and 8 exposures. Following the incidental learning phase, participants completed an explicit learning task where they learned to recognize written translation equivalents of auditory FL word forms, half of which had occurred in the incidental learning phase. The results showed that participants performed better on the words they had previously been exposed to, and that this incidental learning effect occurred from as little as 2 exposures to the multimodal stimuli. In addition, repeated exposure to the stimuli was found to have a larger impact on learning during the first few exposures and decrease thereafter, suggesting that the effects of repeated exposure on vocabulary acquisition are not necessarily constant.

  7. Repeatability and responsiveness of exercise tests in pulmonary arterial hypertension.

    Science.gov (United States)

    Mainguy, Vincent; Malenfant, Simon; Neyron, Anne-Sophie; Bonnet, Sébastien; Maltais, François; Saey, Didier; Provencher, Steeve

    2013-08-01

    Exercise tolerance in pulmonary arterial hypertension (PAH) is most commonly assessed by the 6-min walk test (6MWT). Whether endurance exercise tests are more responsive than the 6MWT remains unknown. 20 stable PAH patients (mean±sd age 53±15 years and mean pulmonary arterial pressure 44±16 mmHg) already on PAH monotherapy completed the 6MWT, the endurance shuttle walk test (ESWT) and the cycle endurance test (CET) before and after the addition of sildenafil citrate 20 mg three times daily or placebo for 28 days in a randomised double-blind crossover setting. Pre- or post-placebo tests were used to assess repeatability of each exercise test, whereas pre- or post-sildenafil citrate tests were used to assess their responsiveness. Sildenafil citrate led to placebo-corrected changes in exercise capacity of 18±25 m (p = 0.02), 58±235 s (p = 0.58) and 29±77 s (p = 0.09) for the 6MWT, the ESWT and the CET, respectively. The 6MWT was associated with a lower coefficient of variation between repeated measures (3% versus 18% versus 13%), resulting in a higher standardised response mean compared with endurance tests (0.72, 0.25 and 0.38 for the 6MWT, the ESWT and the CET, respectively). The 6MWT had the best ability to capture changes in exercise capacity when sildenafil citrate was combined with patients' baseline monotherapy, supporting its use as an outcome measure in PAH.

  8. Effect of squatting on sprinting performance and repeated exposure to complex training in male rugby players.

    Science.gov (United States)

    Comyns, Thomas M; Harrison, Andrew J; Hennessy, Liam K

    2010-03-01

    This study was undertaken to examine the effect of a heavy weight training exercise on sprinting performance and on the effect of repeated exposure to a complex training protocol. Eleven male rugby union players (age 20.9 +/- 3.1 years) participated in the study, which involved 5 separate testing sessions. Back squat 3 repetition maximum (3RM) was established in session 1. Sessions 2-5 were identical and involved the subjects completing a 30-m sprint before and after a 3RM back squat protocol. Four minutes of rest was given between the back squatting and the posttest 30-m sprint. All sprint trials were measured with a laser measurement device (LAVEG, Jenoptik, Jena, Germany). Sprint time and instantaneous, average, and maximum velocity were the dependent variables. The criterion for significance was set at an alpha level of p > or = 0.05. No significant improvement was evident for any of the testing sessions (p > or = 0.05). In session 1, there was a significant increase in 30-m time and a significant reduction in average 30-m velocity and maximum velocity (p benefits in sprinting may not have been realized because of intra and intersubject variations in sprint technique. The session x phase interaction revealed a significant improvement in the pre to posttest changes in instantaneous velocity at 20 m (p = 0.035) and 30 m (p = 0.036) from session 1 to session 4. This indicates that the rugby players may be able to learn to apply the potentiation effects of complex training. From a practical perspective, players may need repeated exposure to this training modality to gain benefit from it, and this should be reflected in program planning.

  9. Animal Exposure During Burn Tests

    Science.gov (United States)

    Gaume, J. G.

    1978-01-01

    An animal exposure test system (AETS) was designed and fabricated for the purpose of collecting physiological and environmental (temperature) data from animal subjects exposed to combustion gases in large scale fire tests. The AETS consisted of an open wire mesh, two-compartment cage, one containing an exercise wheel for small rodents, and the other containing one rat instrumented externally for electrocardiogram (ECG) and respiration. Cage temperature is measured by a thermistor located in the upper portion of the rat compartment. Animal activity is monitored by the ECG and the records indicate an increase in EMG (electromyograph) noise super-imposed by the increased activity of the torso musculature. Examples of the recordings are presented and discussed as to their significance regarding toxicity of fire gases and specific events occurring during the test. The AETS was shown to be a useful tool in screening materials for the relative toxicity of their outgassing products during pyrolysis and combustion.

  10. Effects of repeated exposure to white noise on central cholinergic activity in the rat.

    Science.gov (United States)

    Lai, H

    1988-03-01

    Acute (45 min) exposure to noise has been shown to decrease sodium-dependent high-affinity choline uptake activity in the frontal cortex and hippocampus of the rat. In the present experiment, the effects of repeated noise exposure on choline uptake in these two brain regions were studied. Rats were exposed to 100-dB white noise in ten 45-min sessions. Tolerance developed to the effects of noise on choline uptake. In addition, the effects were found to be classically conditionable to cues in the exposure environment. These data may have important implications in understanding the health hazard of noise exposure in both the public and occupational environments.

  11. The hidden price of repeated traumatic exposure: Different cognitive deficits in different first-responders

    Directory of Open Access Journals (Sweden)

    Einat eLevy-Gigi

    2014-08-01

    Full Text Available Studies on first responders who are repeatedly exposed to traumatic events report low levels of PTSD symptoms and diagnosis. However, neuroimaging and behavioral studies show that traumatic exposure is associated with brain and cognitive dysfunctions. Taking together it may suggest that traumatic exposure have a price, which is not sufficiently defined by the standard PTSD measures. In a recent study we revealed that similar to individuals with PTSD, non-PTSD highly exposed firefighters display a selective impairment in hippocampal related functions. In the current study we aimed to test whether different first responders display a similar impairment. We concentrated on unique populations of active duty firefighters and criminal scene-investigators (CSI police, who are frequently exposed to similar levels and types of traumatic events, and compared them to civilian matched-controls with no history of trauma-exposure. We used a hippocampal dependent cue-context reversal paradigm, which separately evaluates reversal of negative and positive outcomes of cue and context related information. We predicted and found that all participants were equally able to acquire and retain stimulus-outcome associations. However, there were significant differences in reversal learning between the groups. Performance among firefighters replicated our prior findings; they struggled to learn that a previously negative context is later associated with a positive outcome. CSI police on the other hand showed a selective impairment in reversing the outcome of a negative cue. Hence after learning that a specific cue is associated with a negative outcome, they could not learn that later it is associated with a positive outcome. Performance in both groups did not correlate with levels of PTSD, anxiety, depression or behavioral inhibition symptoms. The results provide further evidence of the hidden price of traumatic exposure, suggesting that this price may differ as a

  12. Primary blast survival and injury risk assessment for repeated blast exposures.

    Science.gov (United States)

    Panzer, Matthew B; Bass, Cameron R Dale; Rafaels, Karin A; Shridharani, Jay; Capehart, Bruce P

    2012-02-01

    The widespread use of explosives by modern insurgents and terrorists has increased the potential frequency of blast exposure in soldiers and civilians. This growing threat highlights the importance of understanding and evaluating blast injury risk and the increase of injury risk from exposure to repeated blast effects. Data from more than 3,250 large animal experiments were collected from studies focusing on the effects of blast exposure. The current study uses 2,349 experiments from the data collection for analysis of the primary blast injury and survival risk for both long- and short-duration blasts, including the effects from repeated exposures. A piecewise linear logistic regression was performed on the data to develop survival and injury risk assessment curves. New injury risk assessment curves uniting long- and short-duration blasts were developed for incident and reflected pressure measures and were used to evaluate the risk of injury based on blast over pressure, positive-phase duration, and the number of repeated exposures. The risk assessments were derived for three levels of injury severity: nonauditory, pulmonary, and fatality. The analysis showed a marked initial decrease in injury tolerance with each subsequent blast exposure. This effect decreases with increasing number of blast exposures. The new injury risk functions showed good agreement with the existing experimental data and provided a simplified model for primary blast injury risk. This model can be used to predict blast injury or fatality risk for single exposure and repeated exposure cases and has application in modern combat scenarios or in setting occupational health limits. .Copyright © 2012 by Lippincott Williams & Wilkins

  13. Glucometabolic effects of single and repeated exposure to forced-swimming stressor in Sprague-Dawley rats.

    Science.gov (United States)

    Morakinyo, Ayodele Olufemi; Iranloye, Bolanle Olubusola; Ogunsola, Oluseyi Abimbola

    2018-04-01

    We aimed to evaluate the effects of a single (acute) and repeated (chronic) exposure to forced-swimming stressor on glucose tolerance, insulin sensitivity, lipid profile and glycogen content in male rats. Thirty adult male Sprague-Dawley rats (12 weeks old) were divided randomly into five groups: control group, single exposure (SE) to forced-swim stressor, repeated exposure to forced-swim stressor for 7 days (RE7), 14 days (RE14) and 28 days (RE28). Glucose tolerance test and Homeostatic Model Assessment-Insulin Resistance (HOMA-IR) were undertaken on fasting rats to obtain glucose and insulin profiles. ELISA was performed to assess plasma insulin and corticosterone levels. Total cholesterol, triglyceride, high- and low-density lipoproteins, hepatic and skeletal glycogen content were also determined. Repeated exposure to stressor induced glucose intolerance and insulin resistance in the experimental rats. Results showed that all RE groups exhibited a significantly higher area under the curve compared with others (p=0.0001); similarly, HOMA-IR increased (p=0.0001) in all RE groups compared with control. Prolonged exposure to stressor significantly increased the plasma insulin and corticosterone levels but decreased the glycogen content in the liver and skeletal muscle when compared with the control group. Additionally, chronic stressor significantly increased the total cholesterol and triglyceride levels, however, acute stressor produced significantly elevated high-density lipoproteins level. In conclusion, repeated exposure to forced-swimming stressor induced glucose intolerance and insulin resistance in rats by disrupting the insulin sensitivity as well as heightening the glycogenolysis in the liver and skeletal muscle. Acute stressor was unable to cause glucose intolerance and insulin resistance but it appears that may have a positive effect on the lipid metabolism.

  14. Repeated exposure of adult rats to transient oxidative stress induces various long-lasting alterations in cognitive and behavioral functions.

    Directory of Open Access Journals (Sweden)

    Yoshio Iguchi

    Full Text Available Exposure of neonates to oxidative stress may increase the risk of psychiatric disorders such as schizophrenia in adulthood. However, the effects of moderate oxidative stress on the adult brain are not completely understood. To address this issue, we systemically administrated 2-cyclohexen-1-one (CHX to adult rats to transiently reduce glutathione levels. Repeated administration of CHX did not affect the acquisition or motivation of an appetitive instrumental behavior (lever pressing rewarded by a food outcome under a progressive ratio schedule. In addition, response discrimination and reversal learning were not affected. However, acute CHX administration blunted the sensitivity of the instrumental performance to outcome devaluation, and this effect was prolonged in rats with a history of repeated CHX exposure, representing pro-depression-like phenotypes. On the other hand, repeated CHX administration reduced immobility in forced swimming tests and blunted acute cocaine-induced behaviors, implicating antidepressant-like effects. Multivariate analyses segregated a characteristic group of behavioral variables influenced by repeated CHX administration. Taken together, these findings suggest that repeated administration of CHX to adult rats did not cause a specific mental disorder, but it induced long-term alterations in behavioral and cognitive functions, possibly related to specific neural correlates.

  15. Occupational hazards of traditional healers: repeated unprotected blood exposures risk infectious disease transmission.

    Science.gov (United States)

    Audet, Carolyn M; Salato, José; Blevins, Meridith; Silva, Wilson; González-Calvo, Lázaro; Vermund, Sten H; Gaspar, Felisbela

    2016-11-01

    Healers provide support for acute and chronic illnesses in rural Mozambique, such as socially acceptable traditional 'vaccinations' (subcutaneous cuts in the skin to rub herbs directly into the bloody lesion). We aimed to document the frequency of blood exposure by traditional practitioners in Mozambique. We conducted surveys with a simple random sample of 236 traditional healers in Zambézia province. Chi-square and Wilcoxon rank-sum tests were used to compare 'injection' behaviours across districts. Healers treated a median of eight patients in the past month (IQR: 4-15). About 75% conducted 'injections'. These healers 'injected' a median of four patients (IQR: 1-8), used a new razor a median of three times (IQR: 1-8), and almost never used gloves. Lifetime blood exposures among those who provided 'injections' during treatments were estimated to be 1758 over a healer's career. The majority of healers are exposed repeatedly to patient blood. Given the high prevalence of HIV, hepatitis B and C virus, and other blood-borne agents, specific healer practices are an occupational hazard and reuse of razors is risky for their clients. © 2016 John Wiley & Sons Ltd.

  16. 30 CFR 250.522 - When do I have to repeat casing diagnostic testing?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When do I have to repeat casing diagnostic... Operations Casing Pressure Management § 250.522 When do I have to repeat casing diagnostic testing? Casing diagnostic testing must be repeated according to the following table: When * * * you must repeat diagnostic...

  17. A re-examination of the mere exposure effect: The influence of repeated exposure on recognition, familiarity, and liking.

    Science.gov (United States)

    Montoya, R Matthew; Horton, Robert S; Vevea, Jack L; Citkowicz, Martyna; Lauber, Elissa A

    2017-05-01

    To evaluate the veracity of models of the mere exposure effect and to understand the processes that moderate the effect, we conducted a meta-analysis of the influence of repeated exposure on liking, familiarity, recognition, among other evaluations. We estimated parameters from 268 curve estimates drawn from 81 articles and revealed that the mere exposure effect was characterized by a positive slope and negative quadratic effect consistent with an inverted-U shaped curve. In fact, such curves were associated with (a) all visual, but not auditory stimuli; (b) exposure durations shorter than 10 s and longer than 1 min; (c) both homogeneous and heterogeneous presentation types; and (d) ratings that were taken after all stimuli were presented. We conclude that existing models for the mere exposure effect do not adequately account for the findings, and we provide a framework to help guide future research. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  18. Deterioration of neurobehavioral performance in resident physicians during repeated exposure to extended duration work shifts.

    Science.gov (United States)

    Anderson, Clare; Sullivan, Jason P; Flynn-Evans, Erin E; Cade, Brian E; Czeisler, Charles A; Lockley, Steven W

    2012-08-01

    Although acute sleep loss during 24- to 30-h extended duration work shifts (EDWS) has been shown to impair the performance of resident physicians, little is known about the effects of cumulative sleep deficiency on performance during residency training. Chronic sleep restriction induces a gradual degradation of neurobehavioral performance and exacerbates the effects of acute sleep loss in the laboratory, yet the extent to which this occurs under real-world conditions is unknown. In this study, the authors quantify the time course of neurobehavioral deterioration due to repeated exposure to EDWS during a 3-week residency rotation. A prospective, repeated-measures, within-subject design. Medical and cardiac intensive care units, Brigham and Women's Hospital, Boston, MA. Thirty-four postgraduate year one resident physicians (23 males; age 28.0 ± 1.83 (standard deviation) years) Residents working a 3-week Q3 schedule (24- to 30-h work shift starts every 3(rd) day), consisting of alternating 24- to 30-h (EDWS) and approximately 8-h shifts, underwent psychomotor vigilance testing before, during, and after each work shift. Mean response time, number of lapses, and slowest 10% of responses were calculated for each test. Residents also maintained daily sleep/wake/work logs. EDWS resulted in cumulative sleep deficiency over the 21-day rotation (6.3 h sleep obtained per day; average 2.3 h sleep obtained per extended shift). Response times deteriorated over a single 24- to 30-h shift (P Performance on the fifth and sixth shift was significantly worse than on the first shift (P performance and exacerbated the effects of acute sleep loss inherent in the 24- to 30-h EDWS that are commonly used in resident schedules.

  19. Developmental differences in stress responding after repeated underwater trauma exposures in rats.

    Science.gov (United States)

    Altman, Daniel E; Simmons, Laurence P; Vuong, Chau T; Taylor, Rachel M; Sousa, Jason C; Marcsisin, Sean R; Zottig, Victor E; Moore, Nicole L T

    2018-05-01

    Adolescence is a distinct developmental period characterized by behavioral and physiological maturation. Rapid ongoing changes during neurodevelopment in particular present potential opportunities for stress to have lasting effects on longitudinal outcomes of behavioral and neuroendocrine function. While adult stress effects on outcomes during adulthood have been characterized, little is known about the lasting effects of adolescent repeated stressor exposure on outcomes during adolescence. We have previously reported different stress responses in adolescent rats relative to adult rats, including a blunted fear response outcome in adulthood in rats stressed during adolescence. The present study characterized the ontogeny of behavioral and neuroendocrine responses to eight underwater trauma (UWT) exposures in rats over a two week poststress time period during adolescence (P34) or adulthood (P83) relative to age-matched control groups that underwent eight swimming episodes without UWT. Repeated UWT exposures starting in adolescence, but not adulthood, resulted in adverse behavioral responses on the elevated plus maze 1 day post-stress. Corticosterone responses did not differ between UWT-exposed and controls for either age group at 1 day or at 7 days poststress, although there was an effect of age on corticosterone levels. We conclude that repeated UWT stress events have a lasting, negative behavioral effect on adolescent rats that is not observed in adult rats after the two-week exposure window. These results suggest that neurophysiological mechanisms underlying recovery from a repeated stressor are immature in adolescence relative to adulthood in rats.

  20. College in the Media: The Relationship between Repeated Exposure and College Expectations

    Science.gov (United States)

    Nuñez, Roland

    2018-01-01

    Media consumption can influence viewer perceptions and attitudes. Recent research on media's effect on college students has failed to address gender differences. Using Mere Repeated Exposure Theory (traditionally used in marketing research), this study aims to answer three research questions regarding college media consumption and college…

  1. Sweet and sour preferences in young children and adults: role of repeated exposure

    NARCIS (Netherlands)

    Liem, D.G.; Graaf, de C.

    2004-01-01

    The authors investigated the influence of repeated exposure to orangeades with added sucrose and different concentrations of citric acid, on the taste preferences of 6- to-11-year-old children and young adults. During an intervention study of 8 days, 59 children (9.2±0.9 years) and 46 young adults

  2. Information technology-based approaches to reducing repeat drug exposure in patients with known drug allergies.

    Science.gov (United States)

    Cresswell, Kathrin M; Sheikh, Aziz

    2008-05-01

    There is increasing interest internationally in ways of reducing the high disease burden resulting from errors in medicine management. Repeat exposure to drugs to which patients have a known allergy has been a repeatedly identified error, often with disastrous consequences. Drug allergies are immunologically mediated reactions that are characterized by specificity and recurrence on reexposure. These repeat reactions should therefore be preventable. We argue that there is insufficient attention being paid to studying and implementing system-based approaches to reducing the risk of such accidental reexposure. Drawing on recent and ongoing research, we discuss a number of information technology-based interventions that can be used to reduce the risk of recurrent exposure. Proven to be effective in this respect are interventions that provide real-time clinical decision support; also promising are interventions aiming to enhance patient recognition, such as bar coding, radiofrequency identification, and biometric technologies.

  3. Beyond Extinction: Prolonged Conditioning and Repeated Threat Exposure Abolish Contextual Renewal of Fear-Potentiated Startle Discrimination but Leave Expectancy Ratings Intact.

    Science.gov (United States)

    Leer, Arne; Haesen, Kim; Vervliet, Bram

    2018-01-01

    Extinction treatments decrease fear via repeated exposures to the conditioned stimulus (CS) and are associated with a return of fear. Alternatively, fear can be reduced via reductions in the perceived intensity of the unconditioned stimulus (US), e.g., through repeated exposures to the US. Promisingly, the few available studies show that repeated US exposures outperform standard extinction. US exposure treatments can decrease fear via two routes: (1) by weakening the CS-US association (extinction-like mechanism), and/or (2) by weakening the subjective US aversiveness (habituation-like mechanism). The current study further investigated the conditions under which US exposure treatment may reduce renewal, by adding a group in which CS-US pairings continued following fear acquisition. During acquisition, participants learned that one of two visual stimuli (CS+/CS-) predicted the occurrence of an aversive electrocutaneous stimulus (US). Next, the background context changed and participants received one of three interventions: repeated CS exposures, (2) repeated US exposures, or (3) continued CS-US pairings. Following repeated CS exposures, test presentations of the CSs in the original conditioning context revealed intact CS+/CS- differentiation in the fear-potentiated startle reflex, while the differentiation was abolished in the other two groups. Differential US expectancy ratings, on the other hand, were intact in all groups. Skin conductance data were inconclusive because standard context renewal following CS exposures did not occur. Unexpectedly, there was no evidence for a habituation-like process having taken place during US exposures or continued CS-US pairings. The results provide further evidence that US exposures outperform the standard extinction treatment and show that effects are similar when US exposures are part of CS-US pairings.

  4. Repeat Chlamydia trachomatis testing among heterosexual STI outpatient clinic visitors in the Netherlands: a longitudinal study.

    Science.gov (United States)

    Visser, Maartje; van Aar, Fleur; Koedijk, Femke D H; Kampman, Carolina J G; Heijne, Janneke C M

    2017-12-20

    Chlamydia infections are common in both men and women, are often asymptomatic and can cause serious complications. Repeat testing in high-risk groups is therefore indicated. In the Netherlands, guidelines on repeat chlamydia testing differ between testing facilities, and knowledge on repeat testing behaviour is limited. Here, we analyse the current repeat testing behaviour of heterosexual STI clinic visitors, and aim to identify groups for which repeat testing advice could be advantageous. Longitudinal surveillance data from all Dutch STI outpatient clinics were used, which included all STI clinic consultations carried out among heterosexual men and women between June 2014 and December 2015. Repeat testing was defined as returning to the same STI clinic between 35 days and 12 months after initial consultation. We calculated chlamydia positivity at repeat test stratified by initial test result and time between consultations. Logistic regression analyses were used to identify predictors of repeat testing, and predictors of having a chlamydia positive repeat test. In total, 140,486 consultations in 75,487 women and 46,286 men were available for analyses. Overall, 15.4% of women and 11.1% of men returned to the STI clinic within the study period. Highest chlamydia positivity at repeat test was seen 3-5 months after initial positive test. Among both women and men, repeat testing was associated with non-Western ethnicity, having had more than two sex partners in the past 6 months, reporting STI symptoms, having a history of STI, and having a chlamydia positive initial test. Among repeat testers, chlamydia positive repeat test was most strongly associated with younger age, followed by a chlamydia positive initial test. Repeat testing most often resulted in a positive test result among young heterosexuals (<25) and heterosexuals of any age with a chlamydia infection at the initial consultation. Further efforts are needed to determine optimal repeat testing strategies.

  5. Repeated nicotine exposure enhances reward-related learning in the rat.

    Science.gov (United States)

    Olausson, Peter; Jentsch, J David; Taylor, Jane R

    2003-07-01

    Repeated exposure to addictive drugs causes neuroadaptive changes in cortico-limbic-striatal circuits that may underlie alterations in incentive-motivational processes and reward-related learning. Such drug-induced alterations may be relevant to drug addiction because enhanced incentive motivation and increased control over behavior by drug-associated stimuli may contribute to aspects of compulsive drug-seeking and drug-taking behaviors. This study investigated the consequences of repeated nicotine treatment on the acquisition and performance of Pavlovian discriminative approach behavior, a measure of reward-related learning, in male rats. Water-restricted rats were trained to associate a compound conditioned stimulus (tone+light) with the availability of water (the unconditioned stimulus) in 15 consecutive daily sessions. In separate experiments, rats were repeatedly treated with nicotine (0.35 mg/kg, s.c.) either (1) prior to the onset of training, (2) after each daily training session was completed (ie postsession injections), or (3) received nicotine both before the onset of training as well as after each daily training session. In this study, all nicotine treatment schedules increased Pavlovian discriminative approach behavior and, thus, prior repeated exposure to nicotine, repeated postsession nicotine injections, or both, facilitated reward-related learning.

  6. Biological effects of repeated exposure of beagle dogs to relatively insoluble aerosols of 144Ce. IV

    International Nuclear Information System (INIS)

    Boecker, B.B.; Hahn, F.F.; Hanika-Rebar, C.; McClellan, R.O.; Mauderly, J.L.; Pickrell, J.A.

    1977-01-01

    This experiment is being conducted to study the behavior and long-term biological effects in Beagle dogs of 144 Ce inhaled in fused aluminosilicate particles in repeated inhalation exposures for comparison with similar data from dogs that were exposed only once to a similar aerosol. Four groups of nine dogs each were exposed once every eight weeks for two years (13 exposures) to achieve specified exposure goals. The 144 Ce-exposed dogs received increasing or relatively constant beta radiation dose rates in contrast to the steadily decreasing dose rate seen after a single inhalation exposure. Exposures in the first and second groups were planned to yield a cumulative absorbed dose to lung of approximately equal to 35,000 rads and those in the third group approximately equal to 17,000 rads within two years after the first exposure. Singly exposed dogs that had died with pulmonary tumors when this experiment was initiated had cumulative doses to death of 29,000 to 61,000 rads. All 13 exposures have been completed. One dog in the 4.5-μCi 144 Ce/kg body weight group died at 771 days after first exposure with emaciation, adrenal cortical degeneration and bone marrow aplasia. One control dog died accidentally during anesthesia. During the past year, two additional dogs have died. One dog in the repeated 2.5-μCi 144 Ce/kg body weight group died at 1256 days after the first exposure with radiation pneumonitis and pulmonary fibrosis and a control dog died at 1052 days with autoimmune hemolytic anemia. The remaining 32 dogs appear to be in good physical condition except for a persistent lymphopenia at approximately equal to 4 years after the first exposure. They are being maintained for life span observations

  7. Amiodarone biokinetics, the formation of its major oxidative metabolite and neurotoxicity after acute and repeated exposure of brain cell cultures.

    Science.gov (United States)

    Pomponio, Giuliana; Zurich, Marie-Gabrielle; Schultz, Luise; Weiss, Dieter G; Romanelli, Luca; Gramowski-Voss, Alexandra; Di Consiglio, Emma; Testai, Emanuela

    2015-12-25

    The difficulty in mimicking nervous system complexity and cell-cell interactions as well as the lack of kinetics information has limited the use of in vitro neurotoxicity data. Here, we assessed the biokinetic profile as well as the neurotoxicity of Amiodarone after acute and repeated exposure in two advanced rodent brain cell culture models, consisting of both neurons and glial cells organized in 2 or 3 dimensions to mimic the brain histiotypic structure and function. A strategy was applied to evidence the abiotic processes possibly affecting Amiodarone in vitro bioavailability, showing its ability to adsorb to the plastic devices. At clinically relevant Amiodarone concentrations, known to induce neurotoxicity in some patients during therapeutic treatment, a complete uptake was observed in both models in 24 h, after single exposure. After repeated treatments, bioaccumulation was observed, especially in the 3D cell model, together with a greater alteration of neurotoxicity markers. After 14 days, Amiodarone major oxidative metabolite (mono-N-desethylamiodarone) was detected at limited levels, indicating the presence of active drug metabolism enzymes (i.e. cytochrome P450) in both models. The assessment of biokinetics provides useful information on the relevance of in vitro toxicity data and should be considered in the design of an Integrated Testing Strategy aimed to identify specific neurotoxic alerts, and to improve the neurotoxicity assay predictivity for human acute and repeated exposure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Long-term health outcomes after exposure to repeated concussion in elite level: rugby union players.

    Science.gov (United States)

    McMillan, T M; McSkimming, P; Wainman-Lefley, J; Maclean, L M; Hay, J; McConnachie, A; Stewart, W

    2017-06-01

    There is continuing concern about effects of concussion in athletes, including risk of the neurodegenerative disease chronic traumatic encephalopathy. However, information on long-term health and wellbeing in former athletes is limited. Outcome after exposure to repeated brain injury was investigated in 52 retired male Scottish international rugby players (RIRP) and 29 male controls who were similar in age and social deprivation. Assessment included history of playing rugby and traumatic brain injury, general and mental health, life stress, concussion symptoms, cognitive function, disability and markers of chronic stress (allostatic load). The estimated number of concussions in RIRP averaged 14 (median=7; IQR 5-40). Performance was poorer in RIRP than controls on a test of verbal learning (p=0.022) and of fine co-ordination of the dominant hand (p=0.038) and not significantly different on other cognitive tests (p>0.05). There were no significant associations between number of concussions and performance on cognitive tests. Other than a higher incidence of cardiovascular disease in controls, no group differences were detected in general or mental health or estimates of allostatic load. In RIRP, persisting symptoms attributed to concussion were more common if reporting more than nine concussions (p=0.028), although these symptoms were not perceived to affect social or work functioning. Despite a high number of concussions in RIRP, differences in mental health, social or work functioning were not found late after injury. Subtle group differences were detected on two cognitive tests, the cause of which is uncertain. Prospective group comparison studies on representative cohorts are required. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  9. Impact of repeated exposure on toxicity of perchloroethylene in Swiss Webster mice

    International Nuclear Information System (INIS)

    Philip, Binu K.; Mumtaz, Moiz M.; Latendresse, John R.; Mehendale, Harihara M.

    2007-01-01

    The aim was to study the subchronic toxicity of perchloroethylene (Perc) by measuring injury and repair in liver and kidney in relation to disposition of Perc and its major metabolites. Male SW mice (25-29 g) were given three dose levels of Perc (150, 500, and 1000 mg/kg day) via aqueous gavage for 30 days. Tissue injury was measured during the dosing regimen (0, 1, 7, 14, and 30 days) and over a time course of 24-96 h after the last dose (30 days). Perc produced significant liver injury (ALT) after single day exposure to all three doses. Liver injury was mild to moderate and regressed following repeated exposure for 30 days. Subchronic Perc exposure induced neither kidney injury nor dysfunction during the entire time course as evidenced by normal renal histology and BUN. TCA was the major metabolite detected in blood, liver, and kidney. Traces of DCA were also detected in blood at initial time points after single day exposure. With single day exposure, metabolism of Perc to TCA was saturated with all three doses. AUC/dose ratio for TCA was significantly decreased with a concomitant increase in AUC/dose of Perc levels in liver and kidney after 30 days as compared to 1 day exposures, indicating inhibition of metabolism upon repeated exposure to Perc. Hepatic CYP2E1 expression and activity were unchanged indicating that CYP2E1 is not the critical enzyme inhibited. Hepatic CYP4A expression, measured as a marker of peroxisome proliferation was increased transiently only on day 7 with the high dose, but was unchanged at later time points. Liver tissue repair peaked at 7 days, with all three doses and was sustained after medium and high dose exposure for 14 days. These data indicate that subchronic Perc exposure via aqueous gavage does not induce nephrotoxicity and sustained hepatotoxicity suggesting adaptive hepatic repair mechanisms. Enzymes other than CYP2E1, involved in the metabolism of Perc may play a critical role in the metabolism of Perc upon subchronic exposure

  10. Effects of repeated exposure to either vegetables or fruits on infant's vegetable and fruit acceptance at the beginning of weaning

    NARCIS (Netherlands)

    Barends, C.; Vries, de J.; Mojet, J.; Graaf, de C.

    2013-01-01

    This study investigated the effects of repeated exposure to either vegetables or fruits on an infant's vegetable and fruit acceptance during the first 18 days of weaning. We hypothesized that repeated exposure to a type of vegetable or fruit, would increase its intake. Furthermore, we expected that

  11. A model of human nasal epithelial cells adapted for direct and repeated exposure to airborne pollutants.

    Science.gov (United States)

    Bardet, Gaëlle; Achard, Sophie; Loret, Thomas; Desauziers, Valérie; Momas, Isabelle; Seta, Nathalie

    2014-08-17

    Airway epithelium lining the nasal cavity plays a pivotal role in respiratory tract defense and protection mechanisms. Air pollution induces alterations linked to airway diseases such as asthma. Only very few in vitro studies to date have succeeded in reproducing physiological conditions relevant to cellular type and chronic atmospheric pollution exposure. We therefore, set up an in vitro model of human Airway Epithelial Cells of Nasal origin (hAECN) close to real human cell functionality, specifically adapted to study the biological effects of exposure to indoor gaseous pollution at the environmental level. hAECN were exposed under air-liquid interface, one, two, or three-times at 24 h intervals for 1 h, to air or formaldehyde (200 μg/m(3)), an indoor air gaseous pollutant. All experiments were ended at day 4, when both cellular viability and cytokine production were assessed. Optimal adherence and confluence of cells were obtained 96 h after cell seeding onto collagen IV-precoated insert. Direct and repeated exposure to formaldehyde did not produce any cellular damage or IL-6 production change, although weak lower IL-8 production was observed only after the third exposure. Our model is significantly better than previous ones due to cell type and the repeated exposure protocol. Copyright © 2014. Published by Elsevier Ireland Ltd.

  12. Eye lens radiation exposure and repeated head CT scans: A problem to keep in mind

    International Nuclear Information System (INIS)

    Michel, Morgane; Jacob, Sophie; Roger, Gilles; Pelosse, Béatrice; Laurier, Dominique; Le Pointe, Hubert Ducou; Bernier, Marie-Odile

    2012-01-01

    Objectives: The deterministic character of radiation-induced cataract is being called into question, raising the possibility of a risk in patients, especially children, exposed to ionizing radiation in case of repeated head CT-scans. This study aims to estimate the eye lens doses of a pediatric population exposed to repeated head CTs and to assess the feasibility of an epidemiological study. Methods: Children treated for a cholesteatoma, who had had at least one CT-scan of the middle ear before their tenth birthday, were included. Radiation exposure has been assessed from medical records and telephone interviews. Results: Out of the 39 subjects contacted, 32 accepted to participate. A total of 76 CT-scans were retrieved from medical records. At the time of the interview (mean age: 16 years), the mean number of CT per child was 3. Cumulative mean effective and eye lens doses were 1.7 mSv and 168 mGy, respectively. Conclusion: A relatively high lens radiation dose was observed in children exposed to repeated CT-scans. Due to that exposure and despite the difficulties met when trying to reach patients’ families, a large scale epidemiological study should be performed in order to assess the risk of radiation-induced cataracts associated with repeated head CT.

  13. Perturbations in different forms of cost/benefit decision making induced by repeated amphetamine exposure.

    Science.gov (United States)

    Floresco, Stan B; Whelan, Jennifer M

    2009-08-01

    Psychostimulant abuse has been linked to impairments in cost-benefit decision making. We assessed the effects of repeated amphetamine (AMPH) treatment in rodents on two distinct forms of decision making. Separate groups of rats were trained for 26 days on either a probabilistic (risk) or effort-discounting task, each consisting of four discrete blocks of ten choice trials. One lever always delivered a smaller reward (one or two pellets), whereas another lever delivered a four-pellet reward. For risk-discounting, the probability of receiving the larger reward decreased across trial blocks (100-12.5%), whereas on the effort task, four pellets could be obtained after a ratio of presses that increased across blocks (2-20). After training, rats received 15 saline or AMPH injections (escalating from 1 to 5 mg/kg) and were then retested during acute and long-term withdrawal. Repeated AMPH administration increased risky choice 2-3 weeks after drug exposure, whereas these treatments did not alter effort-based decision making in a separate group of animals. However, prior AMPH exposure sensitized the effects of acute AMPH on both forms of decision making, whereby lower doses were effective at inducing "risky" and "lazy" patterns of choice. Repeated AMPH exposure leads to relatively long-lasting increases in risky choice, as well as sensitization to the effects of acute AMPH on different forms of cost/benefit decision making. These findings suggest that maladaptive decision-making processes exhibited by psychostimulant abusers may be caused in part by repeated drug exposure.

  14. Adaptive Changes In Postural Equilibrium And Motion Sickness Following Repeated Exposures To Virtual Environments

    Science.gov (United States)

    Harm, D. L.; Taylor, L. C.

    2006-01-01

    Virtual environments offer unique training opportunities, particularly for training astronauts and preadapting them to the novel sensory conditions of microgravity. Two unresolved human factors issues in virtual reality (VR) systems are: 1) potential "cybersickness", and 2) maladaptive sensorimotor performance following exposure to VR systems. Interestingly, these aftereffects are often quite similar to adaptive sensorimotor responses observed in astronauts during and/or following space flight. Changes in the environmental sensory stimulus conditions and the way we interact with the new stimuli may result in motion sickness, and perceptual, spatial orientation and sensorimotor disturbances. Initial interpretation of novel sensory information may be inappropriate and result in perceptual errors. Active exploratory behavior in a new environment, with resulting feedback and the formation of new associations between sensory inputs and response outputs, promotes appropriate perception and motor control in the new environment. Thus, people adapt to consistent, sustained alterations of sensory input such as those produced by microgravity, unilateral labyrinthectomy and experimentally produced stimulus rearrangements. Adaptation is revealed by aftereffects including perceptual disturbances and sensorimotor control disturbances. The purpose of the current study was to compare disturbances in postural control produced by dome and head-mounted virtual environment displays, and to examine the effects of exposure duration, and repeated exposures to VR systems. Forty-one subjects (21 men, 20 women) participated in the study with an age range of 21-49 years old. One training session was completed in order to achieve stable performance on the posture and VR tasks before participating in the experimental sessions. Three experimental sessions were performed each separated by one day. The subjects performed a navigation and pick and place task in either a dome or head-mounted display

  15. Effects of single and repeated exposure to biocidal active substances on the barrier function of the skin in vitro.

    Science.gov (United States)

    Buist, Harrie E; van de Sandt, Johannes J M; van Burgsteden, Johan A; de Heer, Cees

    2005-10-01

    The dermal route of exposure is important in worker exposure to biocidal products. Many biocidal active substances which are used on a daily basis may decrease the barrier function of the skin to a larger extent than current risk assessment practice addresses, due to possible skin effects of repeated exposure. The influence of repeated and single exposure to representative biocidal active substances on the skin barrier was investigated in vitro. The biocidal active substances selected were alkyldimethylbenzylammonium chloride (ADBAC), boric acid, deltamethrin, dimethyldidecylammonium chloride (DDAC), formaldehyde, permethrin, piperonyl butoxide, sodium bromide, and tebuconazole. Of these nine compounds, only the quaternary ammonium chlorides ADBAC and DDAC had a clear and consistent influence on skin permeability of the marker compounds tritiated water and [(14)C]propoxur. For these compounds, repeated exposure increased skin permeability more than single exposure. At high concentrations the difference between single and repeated exposure was quantitatively significant: repeated exposure to 300 mg/L ADBAC increased skin permeability two to threefold in comparison to single exposure. Therefore, single and repeated exposure to specific biocidal products may significantly increase skin permeability, especially when used undiluted.

  16. Enhancing consumer liking of low salt tomato soup over repeated exposure by herb and spice seasonings.

    Science.gov (United States)

    Ghawi, Sameer Khalil; Rowland, Ian; Methven, Lisa

    2014-10-01

    There is strong evidence for the link between high dietary sodium and increased risk of cardiovascular disease which drives the need to reduce salt content in foods. In this study, herb and spice blends were used to enhance consumer acceptability of a low salt tomato soup (0.26% w/w). Subjects (n = 148) scored their liking of tomato soup samples over 5 consecutive days. The first and last days were pre-and post-exposure visits where all participants rated three tomato soup samples; standard, low salt and low salt with added herbs and spices. The middle 3 days were the repeated exposure phase where participants were divided into three balanced groups; consuming the standard soup, the low salt soup, or the low salt soup with added herbs and spices. Reducing salt in the tomato soup led to a significant decline in consumer acceptability, and incorporating herbs and spices did not lead to an immediate enhancement in liking. However, inclusion of herbs and spices enhanced the perception of the salty taste of the low salt soup to the same level as the standard. Repeated exposure to the herbs and spice-modified soup led to a significant increase in the overall liking and liking of flavour, texture and aftertaste of the soup, whereas no changes in liking were observed for the standard and low salt tomato soups over repeated exposure. Moreover, a positive trend in increasing the post-exposure liking of the herbs and spices soup was observed. The findings suggest that the use of herbs and spices is a useful approach to reduce salt content in foods; however, herbs and spices should be chosen carefully to complement the food as large contrasts in flavour can polarise consumer liking. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Aberrant approach-avoidance conflict resolution following repeated cocaine pre-exposure.

    Science.gov (United States)

    Nguyen, David; Schumacher, Anett; Erb, Suzanne; Ito, Rutsuko

    2015-10-01

    Addiction is characterized by persistence to seek drug reinforcement despite negative consequences. Drug-induced aberrations in approach and avoidance processing likely facilitate the sustenance of addiction pathology. Currently, the effects of repeated drug exposure on the resolution of conflicting approach and avoidance motivational signals have yet to be thoroughly investigated. The present study sought to investigate the effects of cocaine pre-exposure on conflict resolution using novel approach-avoidance paradigms. We used a novel mixed-valence conditioning paradigm to condition cocaine-pre-exposed rats to associate visuo-tactile cues with either the delivery of sucrose reward or shock punishment in the arms in which the cues were presented. Following training, exploration of an arm containing a superimposition of the cues was assessed as a measure of conflict resolution behavior. We also used a mixed-valence runway paradigm wherein cocaine-pre-exposed rats traversed an alleyway toward a goal compartment to receive a pairing of sucrose reward and shock punishment. Latency to enter the goal compartment across trials was taken as a measure of motivational conflict. Our results reveal that cocaine pre-exposure attenuated learning for the aversive cue association in our conditioning paradigm and enhanced preference for mixed-valence stimuli in both paradigms. Repeated cocaine pre-exposure allows appetitive approach motivations to gain greater influence over behavioral output in the context of motivational conflict, due to aberrant positive and negative incentive motivational processing.

  18. No impact of repeated extinction exposures on operant responding maintained by different reinforcer rates.

    Science.gov (United States)

    Bai, John Y H; Podlesnik, Christopher A

    2017-05-01

    Greater rates of intermittent reinforcement in the presence of discriminative stimuli generally produce greater resistance to extinction, consistent with predictions of behavioral momentum theory. Other studies reveal more rapid extinction with higher rates of reinforcers - the partial reinforcement extinction effect. Further, repeated extinction often produces more rapid decreases in operant responding due to learning a discrimination between training and extinction contingencies. The present study examined extinction repeatedly with training with different rates of intermittent reinforcement in a multiple schedule. We assessed whether repeated extinction would reverse the pattern of greater resistance to extinction with greater reinforcer rates. Counter to this prediction, resistance to extinction was consistently greater across twelve assessments of training followed by six successive sessions of extinction. Moreover, patterns of responding during extinction resembled those observed during satiation tests, which should not alter discrimination processes with repeated testing. These findings join others suggesting operant responding in extinction can be durable across repeated tests. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Repeated exposures to roadside particulate matter extracts suppresses pulmonary defense mechanisms, resulting in lipid and protein oxidative damage

    International Nuclear Information System (INIS)

    Pardo, Michal; Porat, Ziv; Rudich, Assaf; Schauer, James J.; Rudich, Yinon

    2016-01-01

    Exposure to particulate matter (PM) pollution in cities and urban canyons can be harmful to the exposed population. However, the underlying mechanisms that lead to health effects are not yet elucidated. It is postulated that exposure to repeated, small, environmentally relevant concentrations can affect lung homeostasis. This study examines the impact of repeated exposures to urban PM on mouse lungs with focus on inflammatory and oxidative stress parameters. Aqueous extracts from collected urban PM were administered to mice by 5 repeated intra-tracheal instillations (IT). Multiple exposures, led to an increase in cytokine levels in both bronchoalveolar lavage fluid and in the blood serum, indicating a systemic reaction. Lung mRNA levels of antioxidant/phase II detoxifying enzymes decreased by exposure to the PM extract, but not when metals were removed by chelation. Finally, disruption of lung tissue oxidant-inflammatory/defense balance was evidenced by increased levels of lipid and protein oxidation. Unlike response to a single IT exposure to the same dose and source of extract, multiple exposures result in lung oxidative damage and a systemic inflammatory reaction. These could be attributed to compromised capacity to activate the protective Nrf2 tissue defense system. It is suggested that water-soluble metals present in urban PM, potentially from break and tire wear, may constitute major drivers of the pulmonary and systemic responses to multiple exposure to urban PM. - Highlights: • Repeated exposure to urban PM cause systemic inflammation and oxidative damage to lung tissue lipids and proteins. • Repeated exposure to these PM extracts decreased transcription of Nrf2 protective genes. • Single as opposed to repeated exposure, induced confined lung response accompanied by activated defense mechanisms. • Metals, potentially from break and tire wear, drive the pulmonary response with exposure to urban PM. - Repeated exposures to urban PM water extracts

  20. Repeated low-dose exposures to sarin, soman, or VX affect acoustic startle in guinea pigs.

    Science.gov (United States)

    Smith, C D; Lee, R B; Moran, A V; Sipos, M L

    2016-01-01

    Chemical warfare nerve agents (CWNAs) are known to cause behavioral abnormalities in cases of human exposures and in animal models. The behavioral consequences of single exposures to CWNAs that cause observable toxic signs are particularly well characterized in animals; however, less is known regarding repeated smaller exposures that may or may not cause observable toxic signs. In the current study, guinea pigs were exposed to fractions (0.1, 0.2, or 0.4) of a medial lethal dose (LD50) of sarin, soman, or VX for two weeks. On each exposure day, and for a post-exposure period, acoustic startle response (ASR) was measured in each animal. Although relatively few studies use guinea pigs to measure behavior, this species is ideal for CWNA-related experiments because their levels of carboxylesterases closely mimic those of humans, unlike rats or mice. Results showed that the 0.4 LD50 doses of soman and VX transiently increased peak startle amplitude by the second week of injections, with amplitude returning to baseline by the second week post-exposure. Sarin also increased peak startle amplitude independent of week. Latencies to peak startle and PPI were affected by agent exposure but not consistently among the three agents. Most of the changes in startle responses returned to baseline following the cessation of exposures. These data suggest that doses of CWNAs not known to produce observable toxic signs in guinea pigs can affect behavior in the ASR paradigm. Further, these deficits are transient and usually return to baseline shortly after the end of a two-week exposure period. Published by Elsevier Inc.

  1. Micronucleus induction by repeated exposure of diagnostic X-ray on oral buccal mucosa

    International Nuclear Information System (INIS)

    Lohith Tejashvi, K.; Suchetha Kumari, N.; Shetty, Shishir Ram

    2012-01-01

    Radiography is the important diagnostic tools essential for diagnosis and planning of orthodontic treatment. X-ray is ionizing radiation which showed various effects include breaking the bond of biological molecules, inducing loss of ability of cell death, increases nuclear alterations. Micronuclei - x000D - (MN) are small chromatin bodies that appear in the cytoplasm by the - x000D - condensation of acrocentric chromosomal fragments or by whole chromosomes. This - x000D - is a sensitive indicator of genetic damage. - x000D - x000D - . To evaluate micronucleus induction by repeated exposure of diagnostic X-ray on human buccal cell. Methods: 25 patients who visiting to ABSMIDS, Department of Oral medicine and Radiology for dental checkup exposed to diagnostic X-ray more than 4 times have been selected for this study. The buccal cell for analysis was collected from the cheek mucosa by means of gentle scraping of epithelial using ice-cream sticks and placed in Buffer saline. This sample was smeared on glass slide and then fixed in methanol:glacial acetic acid (3:1). Air dried and stained with Giemsa for 15-25 minutes. Then 250 cells in each slides were analyzed under microscope and frequency of micronucleus was scored (n=4). Repeated X-ray exposed cells showed micronucleus (1.25%) and nuclear alteration (2.3%) compare to the control. Repeated X-ray exposure leads to induces detectable number of micronucleus and nuclear alterations. (author)

  2. Effect of repeated benzene inhalation exposures on benzene metabolism, binding to hemoglobin, and induction of micronuclei

    International Nuclear Information System (INIS)

    Sabourin, P.J.; Sun, J.D.; MacGregor, J.T.; Wehr, C.M.; Birnbaum, L.S.; Lucier, G.; Henderson, R.F.

    1990-01-01

    Metabolism of benzene is thought to be necessary to produce the toxic effects, including carcinogenicity, associated with benzene exposure. To extrapolate from the results of rodent studies to potential health risks in man, one must know how benzene metabolism is affected by species, dose, dose rate, and repeated versus single exposures. The purpose of our studies was to determine the effect of repeated inhalation exposures on the metabolism of [14C]benzene by rodents. Benzene metabolism was assessed by characterizing and quantitating urinary metabolites, and by quantitating 14C bound to hemoglobin and micronuclei induction. F344/N rats and B6C3F1 mice were exposed, nose-only, to 600 ppm benzene or to air (control) for 6 hr/day, 5 days/week for 3 weeks. On the last day, both benzene-pretreated and control animals were exposed to 600 ppm, 14C-labeled benzene for 6 hr. Individual benzene metabolites in urine collected for 24 hr after the exposure were analyzed. There was a significant decrease in the respiratory rate of mice (but not rats) pretreated with benzene which resulted in lower levels of urinary [14C]benzene metabolites. The analyses indicated that the only effects of benzene pretreatment on the metabolite profile in rat or mouse urine were a slight shift from glucuronidation to sulfation in mice and a shift from sulfation to glucuronidation in rats. Benzene pretreatment also had no effect, in either species, on formation of [14C]benzene-derived hemoglobin adducts. Mice and rats had similar levels of hemoglobin adduct binding, despite the higher metabolism of benzene by mice. This indicates that hemoglobin adduct formation occurs with higher efficiency in rats. After 1 week of exposure to 600 ppm benzene, the frequency of micronucleated, polychromatic erythrocytes (PCEs) in mice was significantly increased

  3. The impact of repeat-testing of common chemistry analytes at critical concentrations.

    Science.gov (United States)

    Onyenekwu, Chinelo P; Hudson, Careen L; Zemlin, Annalise E; Erasmus, Rajiv T

    2014-12-01

    Early notification of critical values by the clinical laboratory to the treating physician is a requirement for accreditation and is essential for effective patient management. Many laboratories automatically repeat a critical value before reporting it to prevent possible misdiagnosis. Given today's advanced instrumentation and quality assurance practices, we questioned the validity of this approach. We performed an audit of repeat-testing in our laboratory to assess for significant differences between initial and repeated test results, estimate the delay caused by repeat-testing and to quantify the cost of repeating these assays. A retrospective audit of repeat-tests for sodium, potassium, calcium and magnesium in the first quarter of 2013 at Tygerberg Academic Laboratory was conducted. Data on the initial and repeat-test values and the time that they were performed was extracted from our laboratory information system. The Clinical Laboratory Improvement Amendment criteria for allowable error were employed to assess for significant difference between results. A total of 2308 repeated tests were studied. There was no significant difference in 2291 (99.3%) of the samples. The average delay ranged from 35 min for magnesium to 42 min for sodium and calcium. At least 2.9% of laboratory running costs for the analytes was spent on repeating them. The practice of repeating a critical test result appears unnecessary as it yields similar results, delays notification to the treating clinician and increases laboratory running costs.

  4. The effects of multiple UV exposures on HIV-LTR (long terminal repeat) expression

    International Nuclear Information System (INIS)

    Schreck, S.; Milton, J.; Panozzo, J.; Libertin, C.R.; Woloschak, G.E.; Loyola Univ., Maywood, IL

    1995-01-01

    Previous studies have shown that cellular stress agents such as UV radiation induce transcription from the long terminal repeat (LTR) of the human immunodeficiency virus (HIV). Using HeLa cells stably transfected with the HIV-LTR sequence, which transcriptionally drives the chloramphenicol acetyl transferase (CAT) reporter gene, we examined the effects of multiple exposures to UVC (254 nm) on HIV-LTR-CAT expression. Low doses (≤ 5 J m -2 ) had no effect on CAT expression, but up to 29-fold induction was observed with 10 J m -2 when cells were harvested 48 h after completion of the exposure. Little difference was noted in induction levels when cells were exposed to one 25 J m -2 dose, viable cells were harvested at 24 h, 48 h or 72 h, and cell lysates were assayed for CAT expression. Two sequential 12.5 J m -2 exposures, given 24 h apart, resulted in an additive effect on CAT expression; these two exposures produced CAT activity equivalent to that induced following a single 25 J m -2 dose. Our data suggest that HIV-LTR requires a specific threshold UV dose in order to elicit induction; a maximal induction dose is also evident; exposures higher than this maximal dose contribute no more to HIV-LTR induction in viable cells. (author)

  5. 17β-Estradiol is required for the sexually dimorphic effects of repeated binge-pattern alcohol exposure on the HPA axis during adolescence.

    Directory of Open Access Journals (Sweden)

    Magdalena M Przybycien-Szymanska

    Full Text Available Alcohol consumption during adolescence has long-term sexually dimorphic effects on anxiety behavior and mood disorders. We have previously shown that repeated binge-pattern alcohol exposure increased the expression of two critical central regulators of stress and anxiety, corticotrophin-releasing hormone (CRH and arginine vasopressin (AVP, in adolescent male rats. By contrast, there was no effect of alcohol on these same genes in adolescent females. Therefore, we tested the hypothesis that 17β-estradiol (E(2, the predominant sex steroid hormone in females, prevents alcohol-induced changes in CRH and AVP gene expression in the paraventricular nucleus (PVN of the hypothalamus. To test this hypothesis, postnatal day (PND 26 females were ovariectomized and given E(2 replacement or cholesterol as a control. Next, they were given an alcohol exposure paradigm of 1 saline alone, 2 acute (single dose or 3 a repeated binge-pattern. Our results showed that acute and repeated binge-pattern alcohol treatment increased plasma ACTH and CORT levels in both E(2- and Ch-treated groups, however habituation to repeated binge-pattern alcohol exposure was evident only in E(2-treated animals. Further, repeated binge-pattern alcohol exposure significantly decreased CRH and AVP mRNA in Ch-, but not E(2-treated animals, which was consistent with our previous observations in gonad intact females. We further tested the effects of E(2 and alcohol treatment on the activity of the wild type CRH promoter in a PVN-derived neuronal cell line. Alcohol increased CRH promoter activity in these cells and concomitant treatment with E(2 completely abolished the effect. Together our data suggest that E(2 regulates the reactivity of the HPA axis to a repeated stressor through modulation of the habituation response and further serves to maintain normal steady state mRNA levels of CRH and AVP in the PVN in response to a repeated alcohol stressor.

  6. Repeat HIV testing during pregnancy and delivery: missed opportunities in a rural district hospital in Zambia

    NARCIS (Netherlands)

    Heemelaar, S.; Habets, N.; Makukula, Z.; van Roosmalen, J.; van den Akker, T.

    2015-01-01

    Objective: To assess coverage of repeat HIV testing among women who delivered in a Zambian hospital. HIV testing of pregnant women and repeat testing every 3 months during pregnancy and breastfeeding is the recommended policy in areas of high HIV prevalence. Methods: A prospective implementation

  7. Utility of repeat testing of critical values: a Q-probes analysis of 86 clinical laboratories.

    Science.gov (United States)

    Lehman, Christopher M; Howanitz, Peter J; Souers, Rhona; Karcher, Donald S

    2014-06-01

    A common laboratory practice is to repeat critical values before reporting the test results to the clinical care provider. This may be an unnecessary step that delays the reporting of critical test results without adding value to the accuracy of the test result. To determine the proportions of repeated chemistry and hematology critical values that differ significantly from the original value as defined by the participating laboratory, to determine the threshold differences defined by the laboratory as clinically significant, and to determine the additional time required to analyze the repeat test. Participants prospectively reviewed critical test results for 4 laboratory tests: glucose, potassium, white blood cell count, and platelet count. Participants reported the following information: initial and repeated test result; time initial and repeat results were first known to laboratory staff; critical result notification time; if the repeat result was still a critical result; if the repeat result was significantly different from the initial result, as judged by the laboratory professional or policy; significant difference threshold, as defined by the laboratory; the make and model of the instrument used for primary and repeat testing. Routine, repeat analysis of critical values is a common practice. Most laboratories did not formally define a significant difference between repeat results. Repeated results were rarely considered significantly different. Median repeated times were at least 17 to 21 minutes for 10% of laboratories. Twenty percent of laboratories reported at least 1 incident in the last calendar year of delayed result reporting that clinicians indicated had adversely affected patient care. Routine repeat analysis of automated chemistry and hematology critical values is unlikely to be clinically useful and may adversely affect patient care.

  8. Repeated allergen exposure reduce early phase airway response and leukotriene release despite upregulation of 5-lipoxygenase pathways

    Directory of Open Access Journals (Sweden)

    Cui Zhi-Hua

    2012-03-01

    Full Text Available Abstract Background Allergen induced early phase airway response and airway plasma exudation are predominantly mediated by inflammatory mast cell mediators including histamine, cysteinyl leukotrienes (cysLTs and thromboxane A2 (TXA2. The aim of the present study was to evaluate whether repeated allergen exposure affects early phase airway response to allergen challenge. Methods A trimellitic anhydride (TMA sensitized guinea pig model was used to investigate the effects of low dose repeated allergen exposure on cholinergic airway responsiveness, early phase airway response and plasma exudation, as well as local airway production of mast cell derived cysteinyl leukotrienes and thromboxane B2 (TXB2 after allergen challenge. Results Repeated low dose allergen exposure increased cholinergic airway responsiveness. In contrast, early phase airway response and plasma exudation in response to a high-dose allergen challenge were strongly attenuated after repeated low dose allergen exposure. Inhibition of the airway response was unspecific to exposed allergen and independent of histamine receptor blocking. Furthermore, a significant reduction of cysteinyl leukotrienes and TXB2 was found in the airways of animals repeatedly exposed to a low dose allergen. However, in vitro stimulation of airway tissue from animals repeatedly exposed to a low dose allergen with arachidonic acid and calcium ionophore (A23187 induced production of cysteinyl leukotrienes and TXB2, suggesting enhanced activity of 5-lipoxygenase and cyclooxygenase pathways. Conclusions The inhibition of the early phase airway response, cysteinyl leukotriene and TXB2 production after repeated allergen exposure may result from unresponsive effector cells.

  9. Aircraft Carrier Exposure Testing of Aircraft Materials

    National Research Council Canada - National Science Library

    Lee, Eui

    2004-01-01

    .... Test and control specimens were affixed on exposure racks and installed on aircraft carriers to compare adhesive bonding primers for aluminum and to determine the static property behavior of various...

  10. Repeated prenatal exposure to valproic acid results in cerebellar hypoplasia and ataxia.

    Science.gov (United States)

    Main, Stacey L; Kulesza, Randy J

    2017-01-06

    Autism spectrum disorder (ASD) is a developmental brain disorder characterized by restricted and repetitive patterns of behavior, social and communication defects, and is commonly associated with difficulties with motor coordination. The etiology of ASD, while mostly idiopathic, has been linked to hereditary factors and teratogens, such as valproic acid (VPA). VPA is used clinically to treat epilepsy, mood disorders, and in the prevention of migraines. The use of VPA during pregnancy significantly increases the risk of ASD in the offspring. Neuropathological studies show decreased cerebellar function in patients with ASD, resulting in gait, balance and coordination impairments. Herein, we have exposed pregnant rats to a repeated oral dose of VPA on embryonic days 10 and 12 and performed a detailed investigation of the structure and function of the cerebellar vermis. We found that throughout all ten lobules of the cerebellar vermis, Purkinje cells were significantly smaller and expression of the calcium binding protein calbindin (CB) was significantly reduced. We also found that dendritic arbors of Purkinje cells were shorter and less complex. Additionally, animals exposed to a repeated dose of VPA performed significantly worse in a number of motor tasks, including beam walking and the rotarod. These results suggest that repeated embryonic exposure to VPA induces significant cerebellar dysfunction and is an effective animal model to study the cerebellar alterations in ASD. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  11. Biological effects of repeated inhalation exposure of beagle dogs to relatively insoluble aerosols of 144Ce

    International Nuclear Information System (INIS)

    Boecker, B.B.; Hahn, F.F.; Muggenburg, B.A.; McClellan, R.O.; Mauderly, J.L.; Pickrell, J.A.

    1980-01-01

    Beagle dogs were exposed repeatedly to a relatively insoluble form of 144 Ce (in fused aluminosilicate particles) to study the deposition, retention, and long-term biological effects for comparison with data from dogs that were exposed only once to a similar aerosol. Four groups of nine dogs each were exposed once every 8 weeks for 2 years (13 exposures) to achieve specified exposure goals. These goals were: to increase the lung burden by 2.5 μCi 144 Ce/kg body weight with each exposure; to reestablish lung burdens of 9 or 4.5 μCi 144 Ce/kg body weight and to expose controls to fused aluminosilicate particles containing nonradioactive cerium. To date, 19 exposed dogs and 2 control dogs have died or were euthanized. The most prevalent findings to date have been pulmonary carcinomas (7 dogs) and hemangiosarcomas in the tracheobronchial lymph nodes (3 dogs). Observations are continuing on the surviving 8 144 Ce-exposed and 7 control dogs who are now at approximately 2500 days (6.8 years) after the first exposure

  12. Distinctive adaptive response to repeated exposure to hydrogen peroxide associated with upregulation of DNA repair genes and cell cycle arrest

    Directory of Open Access Journals (Sweden)

    Gloria A. Santa-Gonzalez

    2016-10-01

    Full Text Available Many environmental and physiological stresses are chronic. Thus, cells are constantly exposed to diverse types of genotoxic insults that challenge genome stability, including those that induce oxidative DNA damage. However, most in vitro studies that model cellular response to oxidative stressors employ short exposures and/or acute stress models. In this study, we tested the hypothesis that chronic and repeated exposure to a micromolar concentration of hydrogen peroxide (H2O2 could activate DNA damage responses, resulting in cellular adaptations. For this purpose, we developed an in vitro model in which we incubated mouse myoblast cells with a steady concentration of ~50 μM H2O2 for one hour daily for seven days, followed by a final challenge of a 10 or 20X higher dose of H2O2 (0.5 or 1 mM. We report that intermittent long-term exposure to this oxidative stimulus nearly eliminated cell toxicity and significantly decreased genotoxicity (in particular, a >5-fold decreased in double-strand breaks resulting from subsequent acute exposure to oxidative stress. This protection was associated with cell cycle arrest in G2/M and induction of expression of nine DNA repair genes. Together, this evidence supports an adaptive response to chronic, low-level oxidative stress that results in genomic protection and up-regulated maintenance of cellular homeostasis.

  13. Physiological responses and manual performance in humans following repeated exposure to severe cold at night.

    Science.gov (United States)

    Ozaki, H; Nagai, Y; Tochihara, Y

    2001-04-01

    We evaluated human physiological responses and the performance of manual tasks during exposure to severe cold (-25 degrees C) at night (0300-0500 hours) and in the afternoon (1500-1700 hours). Thirteen male students wearing standard cold protective clothing occupied a severely cold room (-25 degrees C) for 20 min, and were then transferred to a cool room (10 degrees C) for 20 min. This pattern of exposure was repeated three times, for a total time of exposure to extreme cold of 60 min. The experiments were started either at 1500 hours or 0300 hours and measurements of rectal temperature, skin temperature, blood pressure, performance in a counting task, hand tremor, and subjective responses were made in each condition. At the end of the experiment at night the mean decrease in rectal temperature [0.68 (SEM 0.04) degree C] was significantly greater than that at the end of the experiment in the afternoon [0.55 (SEM 0.08) degree C, P second cold exposure at night the mean increase in diastolic blood pressure [90 (SEM 2.0) mmHg] was significantly greater than that at the end of the second cold exposure in the afternoon [82 (SEM 2.8) mmHg, P second cold exposure at night, mean finger skin temperature [11.8 (SEM 0.8) degrees C] was significantly higher than that at the comparable time in the afternoon [9.0 (SEM 0.7) degrees C, P second cold exposure at night [25.6 (SEM 1.5) degrees C] was significantly higher than in the afternoon [20.1 (SEM 0.8) degrees C, P < 0.01]. The increased skin temperatures in the periphery resulted in increased heat loss. Since peripheral skin temperatures were highest at night, the subjects noted diminished sensations of thermal cold and pain at that time. Manual dexterity at the end of the first cold exposure at night [mean 83.7 (SEM 3.6) times.min-1] had decreased significantly more than at the end of the first cold exposure in the afternoon [mean 89.4 (SEM 3.5) times.min-1, P < 0.01]. These findings of a lowered rectal temperature and

  14. Thermal responses from repeated exposures to severe cold with intermittent warmer temperatures.

    Science.gov (United States)

    Ozaki, H; Enomoto-Koshimizu, H; Tochihara, Y; Nakamura, K

    1998-09-01

    This study was conducted to evaluate physiological reaction and manual performance during exposure to warm (30 degrees C) and cool (10 degrees C) environments after exposure to very low temperatures (-25 degrees C). Furthermore, this experiment was conducted to study whether it is desirable to remove cold-protective jackets in warmer rooms after severe cold exposure. Eight male students remained in an extremely cold room for 20 min, after which they transferred into either the warm room or the cool room for 20 min. This pattern was repeated three times, and the total cold exposure time was 60 min. In the warm and cool rooms, the subjects either removed their cold-protective jackets (Condition A), or wore them continuously (Condition B). Rectal temperature, skin temperatures, manual performance, blood pressure, thermal, comfort and pain sensations were measured during the experiment. The effects of severe cold on almost all measurements in the cool (10 degrees C) environment were greater than those in the warm (30 degrees C) environment under both clothing conditions. The effects of severe cold on all measurements under Condition A except rectal temperature and toe skin temperature were significantly greater than those under Condition B in the cool environment but, not at all differences between Condition A and Condition B in the warm environments were significant. It was recognized that to remove cold-protective jackets in the cool room (10 degrees C) after severe cold exposure promoted the effects of severe cold. When rewarming in the warm resting room (30 degrees C), the physiological and psychological responses and manual performance were not influenced by the presence or absence of cold-protective clothing. These results suggest that it is necessary for workers to make sure to rewarm in the warm room outside of the cold storage and continue to wear cold-protective clothing in the cool room.

  15. Is repeated exposure the holy grail for increasing children's vegetable intake? Lessons learned from a Dutch childcare intervention using various vegetable preparations.

    Science.gov (United States)

    Zeinstra, Gertrude G; Vrijhof, Milou; Kremer, Stefanie

    2018-02-01

    Children's failure to eat enough vegetables highlights the need for effective interventions encouraging this behaviour. The aim of this study was to investigate the effect of repeated exposure to three a priori unfamiliar vegetables, each prepared in two ways, on children's vegetable acceptance in a childcare setting. Two hundred fifty children (mean age 25 months; 57% boys) participated in a pre-test and a post-test, where they were offered pumpkin, courgette, and white radish. The intervention group (N = 125) participated in a 5-month exposure period, where they were exposed repeatedly (∼12x) to the vegetables: pumpkin blanched and as a cracker spread; courgette blanched and as soup; white radish raw and as a cracker spread. The control group (N = 125) maintained their normal routine. Mixed model analyses were used to analyse intake data and Chi-square analyses for willingness to taste. At pre-test, children ate about 20 g of pumpkin and courgette, whereas white radish intake was approximately 10 g. There was a significant positive effect of the intervention for pumpkin (+15 g; p < 0.001) and white radish (+16 g; p = 0.01). Results for willingness to taste were in the same direction. There was no repeated exposure effect for courgette (p = 0.54); this may have been due to its less distinct taste profile or familiarity with boiled courgette. From our findings, we conclude that repeated exposure to multiple unfamiliar vegetable tastes within the daily routine of a childcare setting is effective in improving children's willingness to taste and intake of some of these vegetables. However, repeated exposure may not be sufficient for more familiar or blander tasting vegetables. This implies that one size does not fit all and that additional strategies are needed to increase children's intake of these vegetables. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Analysis of Dextromethorphan and Dextrorphan in Skeletal Remains Following Differential Microclimate Exposure: Comparison of Acute vs. Repeated Drug Exposure.

    Science.gov (United States)

    Morrison, Lucas M; Unger, Kirk A; Watterson, James H

    2017-07-01

    Analysis of dextromethorphan (DXM) and its metabolite dextrorphan (DXT) in skeletal remains of rats following acute (ACU, 75 mg/kg, IP, n = 10) or three repeated (REP, 25 mg/kg, IP, n = 10, 40-min interval) doses of DXM is described. Following dosing and euthanasia, rats decomposed outdoors to skeleton in two different microclimate environments (n = 5 ACU and n = 5 REP at each site): Site A (shaded forest microenvironment) and Site B (rocky substrate exposed to direct sunlight, 600 m from Site A). Two drug-free rats at each site served as negative controls. Skeletal elements (vertebrae, ribs, pelvic girdles, femora, tibiae, skulls and scapulae) were recovered, pulverized and underwent methanolic microwave assisted extraction (MAE). Extracts were analyzed by GC-MS following clean-up by solid-phase extraction (SPE). Drug levels, expressed as mass-normalized response ratios and the ratios of DXT and DXM levels (RRDXT/RRDXM) were compared between drug exposures, microclimate sites, and across skeletal elements. DXM levels differed significantly (P < 0.05) between corresponding bone elements across exposure groups (5/7-site A; 4/7-site B), but no significant differences in DXT levels were observed between corresponding elements. RRDXT/RRDXM differed significantly (P < 0.05) between corresponding bone elements across exposure groups (6/7-site A; 5/7-site B). No significant differences were observed in levels of DXM, DXT or RRDXT/RRDXM between corresponding elements from either group between sites. When data from all bone elements was pooled, levels of DXM and RRDXT/RRDXM differed significantly between exposure groups at each site, while those of DXT did not. For both exposure groups, comparison of pooled data between sites showed no significant differences in levels of DXM, DXT or RRDXT/RRDXM. Different decomposition microclimates did not impede the discrimination of DXM exposure patterns from the analyses of DXM, DXT and RRDXT/RRDXM in bone samples. © The Author 2017

  17. Adaptive Changes in Sensorimotor Coordination and Motion Sickness Following Repeated Exposures to Virtual Environments

    Science.gov (United States)

    Harm, D. L.; Taylor, L. C.; Bloomberg, J. J.

    2007-01-01

    Virtual environments offer unique training opportunities, particularly for training astronauts and preadapting them to the novel sensory conditions of microgravity. Two unresolved human factors issues in virtual reality (VR) systems are: 1) potential "cybersickness", and 2) maladaptive sensorimotor performance following exposure to VR systems. Interestingly, these aftereffects are often quite similar to adaptive sensorimotor responses observed in astronauts during and/or following space flight. Initial interpretation of novel sensory information may be inappropriate and result in perceptual errors. Active exploratory behavior in a new environment, with resulting feedback and the formation of new associations between sensory inputs and response outputs, promotes appropriate perception and motor control in the new environment. Thus, people adapt to consistent, sustained alterations of sensory input such as those produced by microgravity, unilateral labyrinthectomy and experimentally produced stimulus rearrangements. The purpose of this research was to compare disturbances in sensorimotor coordination produced by dome and head-mounted virtual environment displays and to examine the effects of exposure duration, and repeated exposures to VR systems. The first study examined disturbances in balance control, and the second study examined disturbances in eye-head-hand (EHH) and eye-head coordination.

  18. Repeated exposure to immobilization or two different footshock intensities reveals differential adaptation of the hypothalamic-pituitary-adrenal axis.

    Science.gov (United States)

    Rabasa, Cristina; Muñoz-Abellán, Cristina; Daviu, Núria; Nadal, Roser; Armario, Antonio

    2011-05-03

    Factors involved in adaptation to repeated stress are not well-characterized. For instance, acute footshock (FS) of high intensity appears to be less severe than immobilization (IMO) in light of the speed of post-stress recovery of the hypothalamic-pituitary-adrenal (HPA) axis and other physiological variables. However, repeated exposure to IMO consistently resulted in reduction of the HPA response to the same stressor (adaptation), whereas failure to adapt has been usually reported after FS. Thus, in the present work we directly compared the activation of HPA axis and other physiological changes in response to both acute and repeated exposure to IMO and two intensities of FS (medium and high) in adult male rats. Control rats were exposed to the FS boxes but they did not receive shocks. Daily repeated exposure to IMO resulted in significant adaptation of the overall ACTH and corticosterone responses to the stressor. Such a reduction was also observed with repeated exposure to FS boxes and FS-medium, whereas repeated exposure to FS-high only resulted in a small reduction of the corticosterone response during the post-stress period. This suggests that some properties of FS-high make adaptation to it difficult. Interestingly, overall changes in food intake and body weight gain throughout the week of exposure to the stressors reveal a greater impact of IMO than FS-high, indicating that factors other than the intensity of a stressor, at least when evaluated in function of the above physiological variables, can influence HPA adaptation. Since FS exposure is likely to cause more pain than IMO, activation of nociceptive signals above a certain level may negatively affect HPA adaptation to repeated stressors. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Results of repeat tracer tests at Ohaaki, NZ

    International Nuclear Information System (INIS)

    McCabe, W.J.; Morris, C.

    1995-01-01

    During 20 years of tracer testing at Ohaaki a number of wells have been used more than once as tracer injection sites. In studying the various responses obtained it has been necessary to consider variations in the experimental test conditions before making comparisons which relate to field conditions. Some very significant changes have occurred in the field hydrology in recent years and water flow speeds as high as those encountered at Wairakei have been demonstrated. (author). 4 refs., 2 tabs., 10 figs

  20. Driving simulator sickness: Impact on driving performance, influence of blood alcohol concentration, and effect of repeated simulator exposures.

    Science.gov (United States)

    Helland, Arne; Lydersen, Stian; Lervåg, Lone-Eirin; Jenssen, Gunnar D; Mørland, Jørg; Slørdal, Lars

    2016-09-01

    Simulator sickness is a major obstacle to the use of driving simulators for research, training and driver assessment purposes. The purpose of the present study was to investigate the possible influence of simulator sickness on driving performance measures such as standard deviation of lateral position (SDLP), and the effect of alcohol or repeated simulator exposure on the degree of simulator sickness. Twenty healthy male volunteers underwent three simulated driving trials of 1h's duration with a curvy rural road scenario, and rated their degree of simulator sickness after each trial. Subjects drove sober and with blood alcohol concentrations (BAC) of approx. 0.5g/L and 0.9g/L in a randomized order. Simulator sickness score (SSS) did not influence the primary outcome measure SDLP. Higher SSS significantly predicted lower average speed and frequency of steering wheel reversals. These effects seemed to be mitigated by alcohol. Higher BAC significantly predicted lower SSS, suggesting that alcohol inebriation alleviates simulator sickness. The negative relation between the number of previous exposures to the simulator and SSS was not statistically significant, but is consistent with habituation to the sickness-inducing effects, as shown in other studies. Overall, the results suggest no influence of simulator sickness on SDLP or several other driving performance measures. However, simulator sickness seems to cause test subjects to drive more carefully, with lower average speed and fewer steering wheel reversals, hampering the interpretation of these outcomes as measures of driving impairment and safety. BAC and repeated simulator exposures may act as confounding variables by influencing the degree of simulator sickness in experimental studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Mast Cells Limit the Exacerbation of Chronic Allergic Contact Dermatitis in Response to Repeated Allergen Exposure.

    Science.gov (United States)

    Gimenez-Rivera, Vladimir-Andrey; Siebenhaar, Frank; Zimmermann, Carolin; Siiskonen, Hanna; Metz, Martin; Maurer, Marcus

    2016-12-01

    Allergic contact dermatitis is a chronic T cell-driven inflammatory skin disease that is caused by repeated exposure to contact allergens. Based on murine studies of acute contact hypersensitivity, mast cells (MCs) are believed to play a role in its pathogenesis. The role of MCs in chronic allergic contact dermatitis has not been investigated, in part because of the lack of murine models for chronic contact hypersensitivity. We developed and used a chronic contact hypersensitivity model in wild-type and MC-deficient mice and assessed skin inflammatory responses to identify and characterize the role of MCs in chronic allergic contact dermatitis. Ear swelling chronic contact hypersensitivity responses increased markedly, up to 4-fold, in MC-deficient Kit W-sh/W-sh (Sash) and MCPT5-Cre + iDTR + mice compared with wild-type mice. Local engraftment with MCs protected Sash mice from exacerbated ear swelling after repeated oxazolone challenge. Chronic contact hypersensitivity skin of Sash mice exhibited elevated levels of IFN-γ, IL-17α, and IL-23, as well as increased accumulation of Ag-specific IFN-γ-producing CD8 + tissue-resident memory T (T RM ) cells. The CD8 + T cell mitogen IL-15, which was increased in oxazolone-challenged skin of Sash mice during the accumulation of cutaneous T RM cells, was efficiently degraded by MCs in vitro. MCs protect from the exacerbated allergic skin inflammation induced by repeated allergen challenge, at least in part, via effects on CD8 + T RM cells. MCs may notably influence the course of chronic allergic contact dermatitis. A better understanding of their role and the underlying mechanisms may lead to better approaches for the treatment of this common, disabling, and costly condition. Copyright © 2016 by The American Association of Immunologists, Inc.

  2. Repeated exposure to iron oxide nanoparticles causes testicular toxicity in mice.

    Science.gov (United States)

    Sundarraj, Kiruthika; Manickam, Vijayprakash; Raghunath, Azhwar; Periyasamy, Madhivadhani; Viswanathan, Mangala Priya; Perumal, Ekambaram

    2017-02-01

    The aim of this study was to determine whether repeated exposure to iron oxide nanoparticles (Fe 2 O 3 -NPs) could be toxic to mice testis. Fe 2 O 3 -NPs (25 and 50 mg/kg) were intraperitoneally administered into mice once a week for 4 weeks. Our study showed that Fe 2 O 3 -NPs have the ability to cross the blood-testis barrier to get into the testis. The findings showed that exposure resulted in the accumulation of Fe 2 O 3 -NPs which was evidenced from the iron content and accumulation in the testis. Furthermore, 25 and 50 mg/kg Fe 2 O 3 -NPs administration increased the reactive oxygen species, lipid peroxidation, protein carbonyl content, glutathione peroxidase activity, and nitric oxide levels with a concomitant decrease in the levels of antioxidants-superoxide dismutase, catalase, glutathione, and vitamin C. Increased expression of Bax, cleaved-caspase-3, and cleaved-PARP confirms apoptosis. Serum testosterone levels increased with increased concentration of Fe 2 O 3 -NPs exposure. In addition, the histopathological lesions like vacuolization, detachment, and sloughing of germ cells were also observed in response to Fe 2 O 3 -NPs treatment. The data from our study entailed that testicular toxicity caused by Fe 2 O 3 -NPs exposure may be associated with Fe 2 O 3 -NPs accumulation leading to oxidative stress and apoptosis. Therefore, precautions should be taken in the safe use of Fe 2 O 3 -NPs to avoid complications in the fertility of males. Further research will unravel the possible molecular mechanisms on testicular toxicity of Fe 2 O 3 -NPs. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 594-608, 2017. © 2016 Wiley Periodicals, Inc.

  3. Anti-Inflammatory and Antioxidant Effects of Repeated Exposure to Cruciferous Allyl Nitrile in Sensitizer-Induced Ear Edema in Mice.

    Science.gov (United States)

    Tanii, Hideji; Sugitani, Kayo; Saijoh, Kiyofumi

    2016-02-29

    Skin sensitizers induce allergic reactions through the induction of reactive oxygen species. Allyl nitrile from cruciferous vegetables has been reported to induce antioxidants and phase II detoxification enzymes in various tissues. We assessed the effects of repeated exposure to allyl nitrile on sensitizer-induced allergic reactions. Mice were dosed with allyl nitrile (0-200 µmol/kg), and then received a dermal application of 1 of 3 sensitizers on the left ear or 1 of 2 vehicles on the right ear. Quantitative assessment of edema was carried out by measuring the difference in weight between the portions taken from the right and left ears. We tested enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and thiobarbituric acid reactive substances (TBARS) in ears. Repeated exposure to allyl nitrile reduced edemas induced by glutaraldehyde and by 2, 4-dinitrochlorobenzene (DNCB), but not by formaldehyde. The repeated exposure decreased levels of TBARS, a marker of oxidative stress, induced by glutaraldehyde and by DNCB, but not by formaldehyde. Allyl nitrile elevated SOD levels for the 3 sensitizers, and CAT levels for formaldehyde and DNCB. Allyl nitrile also increased GPx levels for formaldehyde and DNCB, but not for glutaraldehyde. The reduced edemas were associated with changes in oxidative stress levels and antioxidant enzymes. Repeated exposure to allyl nitrile reduced allergic reactions induced by glutaraldehyde and by DNCB, but not by formaldehyde. This reduction was associated with changes in ROS levels and antioxidant enzyme activities.

  4. Fatal cardiac arrhythmia after repeated exposure to 1,1-difluoroethane (DFE).

    Science.gov (United States)

    Avella, Joseph; Wilson, James C; Lehrer, Michael

    2006-03-01

    A 42-year-old man was found dead after repeated exposure to 1,1-difluoroethane (DFE, Freon 152a), a propellant found in CRC Duster, a product intended for the removal of dust and lint. Toxicologic analysis detected DFE in femoral blood 136.3 mg/L, brain 117.5 mg/kg, liver 87.6 mg/kg, lung 60.3 mg/kg, adipose 235.7 mg/kg, and vitreous fluid 25.1 mg/L. The cause of death was determined to be a fatal cardiac arrhythmia due to intoxication with 1,1-difluoroethane. After comparison to previously published cases involving DFE, we suggest that analysis of adipose tissue for DFE and similar compounds, along with blood and other tissues, may be useful in distinguishing between acute versus chronic exposure. Adipose may also be a valuable alternate specimen for detection in cases where loss or elimination from blood is likely to have occurred.

  5. Repeated Exposure to Dissection Does Not Influence Students' Attitudes towards Human Body Donation for Anatomy Teaching

    Science.gov (United States)

    Mwachaka, Philip Maseghe; Mandela, Pamela; Saidi, Hassan

    2016-01-01

    The use of unclaimed bodies for anatomical dissection has been the main method of instruction at our institution. There is however a shortage of cadavers for dissection given the increase in the number of medical schools as well as in the number of students enrolling in these schools. This shortage could be mitigated by having voluntary human body donation programs. This study aimed at assessing the attitudes of medical students and surgical residents towards body donation for anatomy learning. We conducted an online survey involving 72 first-year medical students and 41 surgical residents at University of Nairobi who had completed one year of anatomy dissection. For the medical students, this was their first dissection experience while it was the second exposure for the surgery trainees. Most of the surgical trainees (70.7%) and medical students (68.1%) were opposed to self-body donation. This was mainly due to cultural (37%) and religious (20%) barriers. Surprisingly, of those not willing to donate themselves, 67.9% (82.8% surgical trainees, 59.2% medical students) would recommend the practice to other people. Exposure to repeated dissection does not change the perceptions towards body donation. It is noteworthy that culture and religion rank high as clear barriers amongst this “highly informed” group of potential donors. PMID:27190650

  6. Repeated exposure to media violence is associated with diminished response in an inhibitory frontolimbic network.

    Directory of Open Access Journals (Sweden)

    Christopher R Kelly

    Full Text Available BACKGROUND: Media depictions of violence, although often claimed to induce viewer aggression, have not been shown to affect the cortical networks that regulate behavior. METHODOLOGY/PRINCIPAL FINDINGS: Using functional magnetic resonance imaging (fMRI, we found that repeated exposure to violent media, but not to other equally arousing media, led to both diminished response in right lateral orbitofrontal cortex (right ltOFC and a decrease in right ltOFC-amygdala interaction. Reduced function in this network has been previously associated with decreased control over a variety of behaviors, including reactive aggression. Indeed, we found reduced right ltOFC responses to be characteristic of those subjects that reported greater tendencies toward reactive aggression. Furthermore, the violence-induced reduction in right ltOFC response coincided with increased throughput to behavior planning regions. CONCLUSIONS: These novel findings establish that even short-term exposure to violent media can result in diminished responsiveness of a network associated with behaviors such as reactive aggression.

  7. Repeated Exposure to Dissection Does Not Influence Students' Attitudes towards Human Body Donation for Anatomy Teaching.

    Science.gov (United States)

    Mwachaka, Philip Maseghe; Mandela, Pamela; Saidi, Hassan

    2016-01-01

    The use of unclaimed bodies for anatomical dissection has been the main method of instruction at our institution. There is however a shortage of cadavers for dissection given the increase in the number of medical schools as well as in the number of students enrolling in these schools. This shortage could be mitigated by having voluntary human body donation programs. This study aimed at assessing the attitudes of medical students and surgical residents towards body donation for anatomy learning. We conducted an online survey involving 72 first-year medical students and 41 surgical residents at University of Nairobi who had completed one year of anatomy dissection. For the medical students, this was their first dissection experience while it was the second exposure for the surgery trainees. Most of the surgical trainees (70.7%) and medical students (68.1%) were opposed to self-body donation. This was mainly due to cultural (37%) and religious (20%) barriers. Surprisingly, of those not willing to donate themselves, 67.9% (82.8% surgical trainees, 59.2% medical students) would recommend the practice to other people. Exposure to repeated dissection does not change the perceptions towards body donation. It is noteworthy that culture and religion rank high as clear barriers amongst this "highly informed" group of potential donors.

  8. Visual attention to repeated print advertising : A test of scanpath theory

    NARCIS (Netherlands)

    Pieters, F.G.M.; Rosbergen, E.; Wedel, M.

    The authors examine consumers' visual attention during repeated exposures to print advertisements using eye-tracking methodology. The authors propose a statistical model comprising submodels for two key measures of visual attention to elements of the advertisement: attention duration and inter- and

  9. Visual attention to repeated print advertising : A test of scanpath theory

    NARCIS (Netherlands)

    Pieters, F.G.M.; Rosbergen, E.; Wedel, M.

    1999-01-01

    The authors examine consumers' visual attention during repeated exposures to print advertisements using eye-tracking methodology. The authors propose a statistical model comprising submodels for two key measures of visual attention to elements of the advertisement: attention duration and inter- and

  10. Repeated exposures to roadside particulate matter extracts suppresses pulmonary defense mechanisms, resulting in lipid and protein oxidative damage.

    Science.gov (United States)

    Pardo, Michal; Porat, Ziv; Rudich, Assaf; Schauer, James J; Rudich, Yinon

    2016-03-01

    Exposure to particulate matter (PM) pollution in cities and urban canyons can be harmful to the exposed population. However, the underlying mechanisms that lead to health effects are not yet elucidated. It is postulated that exposure to repeated, small, environmentally relevant concentrations can affect lung homeostasis. This study examines the impact of repeated exposures to urban PM on mouse lungs with focus on inflammatory and oxidative stress parameters. Aqueous extracts from collected urban PM were administered to mice by 5 repeated intra-tracheal instillations (IT). Multiple exposures, led to an increase in cytokine levels in both bronchoalveolar lavage fluid and in the blood serum, indicating a systemic reaction. Lung mRNA levels of antioxidant/phase II detoxifying enzymes decreased by exposure to the PM extract, but not when metals were removed by chelation. Finally, disruption of lung tissue oxidant-inflammatory/defense balance was evidenced by increased levels of lipid and protein oxidation. Unlike response to a single IT exposure to the same dose and source of extract, multiple exposures result in lung oxidative damage and a systemic inflammatory reaction. These could be attributed to compromised capacity to activate the protective Nrf2 tissue defense system. It is suggested that water-soluble metals present in urban PM, potentially from break and tire wear, may constitute major drivers of the pulmonary and systemic responses to multiple exposure to urban PM. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Prior exposure to repeated immobilization or chronic unpredictable stress protects from some negative sequels of an acute immobilization.

    Science.gov (United States)

    Pastor-Ciurana, Jordi; Rabasa, Cristina; Ortega-Sánchez, Juan A; Sanchís-Ollè, Maria; Gabriel-Salazar, Marina; Ginesta, Marta; Belda, Xavier; Daviu, Núria; Nadal, Roser; Armario, Antonio

    2014-05-15

    Exposure to chronic unpredictable stress (CUS) is gaining acceptance as a putative animal model of depression. However, there is evidence that chronic exposure to stress can offer non-specific stress protection from some effects of acute superimposed stressors. We then compared in adult male rats the protection afforded by prior exposure to CUS with the one offered by repeated immobilization on boards (IMO) regarding some of the negative consequences of an acute exposure to IMO. Repeated exposure to IMO protected from the negative consequences of an acute IMO on activity in an open-field, saccharin intake and body weight gain. Active coping during IMO (struggling) was markedly reduced by repeated exposure to the same stressor, but it was not affected by a prior history of CUS, suggesting that our CUS protocol does not appear to impair active coping responses. CUS exposure itself caused a strong reduction of activity in the open-field but appeared to protect from the hypo-activity induced by acute IMO. Moreover, prior CUS offered partial protection from acute IMO-induced reduction of saccharin intake and body weight gain. It can be concluded that a prior history of CUS protects from some of the negative consequences of exposure to a novel severe stressor, suggesting the development of partial cross-adaptation whose precise mechanisms remain to be studied. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Impact of product information and repeated exposure on consumer liking, sensory perception and concept associations of local apple juice

    DEFF Research Database (Denmark)

    Stolzenbach, Sandra; Bredie, Wender Laurentius Petrus; Christensen, Rune Haubo Bojesen

    2013-01-01

    The impact of product information and repeated exposure of local apple juice on consumer liking, sensory perception and concept associations was studied. Findings showed that consumers had high expectations towards the studied local apples juices. Consequently, the liking for the local apple juices...... did not fully determine consumer liking. Thus the sensory characteristics were also found to be of importance. Besides liking, the concept associations were also affected by product information. All local apple juices were associated as being more exclusive under informed tasting conditions....... No effects were found for liking of the apple juices over repeated exposure. Also, the consumers did not change their sensory perception over repeated consumption. However, the local apple juices were conceptualised as more familiar but remained exclusive after repeated consumption. When local producers have...

  13. Repeated exposures to cobalt or chromate on the hands of patients with hand eczema and contact allergy to that metal

    DEFF Research Database (Denmark)

    Nielsen, N H; Kristiansen, J; Borg, L

    2000-01-01

    The present study aimed at evaluating the effects of daily repeated exposures to low cobalt or chromate concentrations on the hands of patients with hand eczema and cobalt or chromate allergy. For 2 weeks, the patients immersed a finger for 10 min daily into the appropriate metal salt solution in...... of providing evidence-based medicine in the area of allergic contact dermatitis in the future.......-sensitive patients. During the exposure period, accumulation of cobalt or chromate in the nail was demonstrated. Standardization of chemical methods of quantification of skin exposure to allergens, combined with experimental exposure studies in patients with specific contact allergy, will increase the possibility...

  14. Test-retest repeatability of the pupil light response to blue and red light stimuli in normal human eyes using a novel pupillometer

    DEFF Research Database (Denmark)

    Herbst, Kristina; Sander, Birgit; Milea, Dan

    2011-01-01

    In this study, we evaluated the repeatability of pupil responses to colored light stimuli in healthy subjects using a prototype chromatic pupillometer. One eye of 10 healthy subjects was tested twice in the same day using monochromatic light exposure at two selected wavelengths (660 and 470 nm......, we have developed a novel prototype of color pupillometer which demonstrates good repeatability in evoking and recording the pupillary response to a bright blue and red light stimulus....

  15. Test-retest repeatability of the pupil light response to blue and red light stimuli in normal human eyes using a novel pupillometer

    DEFF Research Database (Denmark)

    Herbst, Kristina; Sander, Birgit; Milea, Dan

    2011-01-01

    In this study, we evaluated the repeatability of pupil responses to colored light stimuli in healthy subjects using a prototype chromatic pupillometer. One eye of 10 healthy subjects was tested twice in the same day using monochromatic light exposure at two selected wavelengths (660 and 470¿nm......, we have developed a novel prototype of color pupillometer which demonstrates good repeatability in evoking and recording the pupillary response to a bright blue and red light stimulus....

  16. Impact of repeated daily exposure to intermittent hypoxia and mild sustained hypercapnia on apnea severity.

    Science.gov (United States)

    Yokhana, Sanar S; Gerst, David G; Lee, Dorothy S; Badr, M Safwan; Qureshi, Tabarak; Mateika, Jason H

    2012-02-01

    We examined whether exposure to intermittent hypoxia (IH) during wakefulness impacted on the apnea/hypopnea index (AHI) during sleep in individuals with sleep apnea. Participants were exposed to twelve 4-min episodes of hypoxia in the presence of sustained mild hypercapnia each day for 10 days. A control group was exposed to sustained mild hypercapnia for a similar duration. The intermittent hypoxia protocol was completed in the evening on day 1 and 10 and was followed by a sleep study. During all sleep studies, the change in esophageal pressure (ΔPes) from the beginning to the end of an apnea and the tidal volume immediately following apneic events were used to measure respiratory drive. Following exposure to IH on day 1 and 10, the AHI increased above baseline measures (day 1: 1.95 ± 0.42 fraction of baseline, P ≤ 0.01, vs. day 10: 1.53 ± 0.24 fraction of baseline, P < 0.06). The indexes were correlated to the hypoxic ventilatory response (HVR) measured during the IH protocol but were not correlated to the magnitude of ventilatory long-term facilitation (vLTF). Likewise, ΔPes and tidal volume measures were greater on day 1 and 10 compared with baseline (ΔPes: -8.37 ± 0.84 vs. -5.90 ± 1.30 cmH(2)0, P ≤ 0.04; tidal volume: 1,193.36 ± 101.85 vs. 1,015.14 ± 119.83 ml, P ≤ 0.01). This was not the case in the control group. Interestingly, the AHI on day 10 (0.78 ± 0.13 fraction of baseline, P ≤ 0.01) was significantly less than measures obtained during baseline and day 1 in the mild hypercapnia control group. We conclude that enhancement of the HVR initiated by exposure to IH may lead to increases in the AHI during sleep and that initiation of vLTF did not appear to impact on breathing stability. Lastly, our results suggest that repeated daily exposure to mild sustained hypercapnia may lead to a decrease in breathing events.

  17. An observation of histological evidence on internal organ damages in mice caused by repeated exposures to motorcycle emissions

    Science.gov (United States)

    Wardoyo, Arinto Y. P.; Juswono, Unggul P.; Noor, Johan A. E.

    2017-05-01

    Motor vehicle emissions have been identified as a source of ultrafine particles, which have significant impacts on human health. Repeated and prolonged exposure to ultrafine particles may have a significant association with organ damage. Here, we evaluated the correlation between repeated exposure to ultrafine particles and organ damage in mice. Motorcycle emissions were injected into an exposure chamber with mice for a period of 20 seconds. This treatment was conducted over 10 days. The mice were sacrificed on the 2nd, 4th, 6th, 8th, and 10th days for organ preparations. Based on the results, motorcycle emission exposure caused organ damage in mice, with different severities depending on the organ. The highest damage was found for the lung, followed by the kidney, erythrocytes, and liver.

  18. Ultra-accelerated natural sunlight exposure testing

    Science.gov (United States)

    Jorgensen, Gary J.; Bingham, Carl; Goggin, Rita; Lewandowski, Allan A.; Netter, Judy C.

    2000-06-13

    Process and apparatus for providing ultra accelerated natural sunlight exposure testing of samples under controlled weathering without introducing unrealistic failure mechanisms in exposed materials and without breaking reciprocity relationships between flux exposure levels and cumulative dose that includes multiple concurrent levels of temperature and relative humidity at high levels of natural sunlight comprising: a) concentrating solar flux uniformly; b) directing the controlled uniform sunlight onto sample materials in a chamber enclosing multiple concurrent levels of temperature and relative humidity to allow the sample materials to be subjected to accelerated irradiance exposure factors for a sufficient period of time in days to provide a corresponding time of about at least a years worth of representative weathering of the sample materials.

  19. Repeat HIV Testing at Voluntary Testing and Counseling Centers in Croatia: Successful HIV Prevention or Failure to Modify Risk Behaviors?

    Science.gov (United States)

    Matković Puljić, Vlatka; Kosanović Ličina, Mirjana Lana; Kavić, Marija; Nemeth Blažić, Tatjana

    2014-01-01

    HIV testing plays a critical role in preventing the spread of the virus and identifying infected individuals in need of care. Voluntary counseling and testing centers (VCTs) not only conduct testing but they also provide counseling. Since a proportion of people who test negative for HIV on their previous visit will return for retesting, the frequency of retesting and the characteristics of those who retest may provide insights into the efficacy of testing and counseling strategies. In this cross-sectional, retrospective study of 1,482 VCT clients in Croatia in 2010, 44.3% had been tested for HIV before. The rate of repeat HIV testing is lower in Croatia than in other countries. Men who have sex with men (MSM) clients, those with three or more sexual partners in the last 12 months, consistent condom users with steady partners, and intravenous drug users were more likely to be repeat testers. This finding suggests that clients presenting for repeat HIV testing are those who self-identify as being at a higher risk of infection. Our data showed that testing positive for HIV was not associated with repeat testing. However, the effects of repeat testing on HIV epidemiology needs to be explored. PMID:24705595

  20. Repeated patch testing to nickel during childhood do not induce nickel sensitization

    DEFF Research Database (Denmark)

    Søgaard Christiansen, Elisabeth

    2014-01-01

    Background: Previously, patch test reactivity to nickel sulphate in a cohort of unselected infants tested repeatedly at 3-72 months of age has been reported. A reproducible positive reaction at 12 and 18 months was selected as a sign of nickel sensitivity, provided a patch test with an empty Finn...

  1. Radiation exposures from nuclear tests at the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, G M

    1958-12-01

    A summary of the pertinent data on radiation exposures from nuclear tests in Nevada is presented. The data are presented in categories of external ..gamma.. radiation, activity concentrations in air, and activity concentrations in water. Methods used to estimate exposure and to evaluate data are described. The data are tabulated. The maximum external exposure was 7 to 8 r for 15 persons involved. In terms of relatively large populations, the average exposure for the 1,000,000 people living nearest the site was at the rate of 1/2 r/30 yr. The highest concentration of fallout activity in the air was about 1.3 ..mu..c/m/sup 3/ averaged over the 30 hr that the activity was present in significant quantities. The highest concentration of fallout activity in a potential drinking water supply was about 1.4 x 10/sup -/ ..mu..c/me extrapolated to D + 3 days. Evaluation of these data is given.

  2. Hearing loss associated with repeated MRI acquisition procedure-related acoustic noise exposure: an occupational cohort study

    NARCIS (Netherlands)

    Bongers, Suzan; Slottje, Pauline; Kromhout, Hans

    2017-01-01

    OBJECTIVE: To study the effects of repeated exposure to MRI-related acoustic noise during image acquisition procedures (scans) on hearing. METHODS: A retrospective occupational cohort study was performed among workers of an MRI manufacturing facility (n=474). Longitudinal audiometry data from the

  3. Lesser Neural Pattern Similarity across Repeated Tests Is Associated with Better Long-Term Memory Retention.

    Science.gov (United States)

    Karlsson Wirebring, Linnea; Wiklund-Hörnqvist, Carola; Eriksson, Johan; Andersson, Micael; Jonsson, Bert; Nyberg, Lars

    2015-07-01

    Encoding and retrieval processes enhance long-term memory performance. The efficiency of encoding processes has recently been linked to representational consistency: the reactivation of a representation that gets more specific each time an item is further studied. Here we examined the complementary hypothesis of whether the efficiency of retrieval processes also is linked to representational consistency. Alternatively, recurrent retrieval might foster representational variability--the altering or adding of underlying memory representations. Human participants studied 60 Swahili-Swedish word pairs before being scanned with fMRI the same day and 1 week later. On Day 1, participants were tested three times on each word pair, and on Day 7 each pair was tested once. A BOLD signal change in right superior parietal cortex was associated with subsequent memory on Day 1 and with successful long-term retention on Day 7. A representational similarity analysis in this parietal region revealed that beneficial recurrent retrieval was associated with representational variability, such that the pattern similarity on Day 1 was lower for retrieved words subsequently remembered compared with those subsequently forgotten. This was mirrored by a monotonically decreased BOLD signal change in dorsolateral prefrontal cortex on Day 1 as a function of repeated successful retrieval for words subsequently remembered, but not for words subsequently forgotten. This reduction in prefrontal response could reflect reduced demands on cognitive control. Collectively, the results offer novel insights into why memory retention benefits from repeated retrieval, and they suggest fundamental differences between repeated study and repeated testing. Repeated testing is known to produce superior long-term retention of the to-be-learned material compared with repeated encoding and other learning techniques, much because it fosters repeated memory retrieval. This study demonstrates that repeated memory

  4. Damage of rat liver tissue caused by repeated and sustained +Gz exposure and the mechanism thereof

    Directory of Open Access Journals (Sweden)

    Wen-bing LI

    2014-03-01

    Full Text Available Objective  To explore the mechanisms of positive acceleration (+Gz on the damage of rat liver tissue and the effect of +Gz on the expression of JNK/c-Jun in liver cells. Methods  Twenty four male Wistar rats were randomly divided into 4 groups (n=6: control, +2Gz, +6Gz and +10Gz group. With prone position, the rats in control group were fixed to the turning arm of centrifuge with head towards the axis for 5 minutes. The fixation method in +2Gz, +6Gz and +10Gz group was the same as in the control group. The increase rate of acceleration was 1G/s with a peak-time of 3 minutes, and each +Gz exposure repeated 5 times with an interval of 30 minutes. HE staining was used to observe the morphological changes of liver tissue, fluorescence real-time quantitative PCR to detect the expression of hepatic c-Jun mRNA, and Western blotting to detect the hepatic protein expression of p-c-Jun, c-Jun, p-JNK and JNK. Plasma aspartate aminotransferase (AST and alanine aminotransferase (ALT were determined. Results  The levels of serum ALT and AST increased significantly in +6Gz and, especially, the +10Gz group than in control group and +2Gz group (P<0.05. The same situation also existed in the increase of c-Jun mRNA expression (P<0.05. Hepatic c-jun and p-c-Jun (c-Jun activated form protein expression increased with the increase of G value. Compared with control group, no change was found in JNK protein expression in the other three groups, but the expression of p-JNK (activated form of JNK increased in +6Gz and +10Gz groups (P<0.05. HE staining showed the disorganized liver cells with irregular shapes, the unclear cell gap and the vacuolar changes in +6Gz and +10Gz groups. Conclusions  Repeated and sustained +Gz may cause enhanced expression of c-Jun/ p-c-Jun and p-JNK in hepatic cells. JNK/c-Jun signaling pathway may play an important role in the process of hepatic stress injury. DOI: 10.11855/j.issn.0577-7402.2014.03.15

  5. Effect of Acute, Subacute, and Repeated Exposure to High Altitude (5050 m on Psychomotor Vigilance

    Directory of Open Access Journals (Sweden)

    Matiram Pun

    2018-06-01

    Full Text Available Aim: High altitude (HA hypoxia may affect cognitive performance and sleep quality. Further, vigilance is reduced following sleep deprivation. We investigated the effect on vigilance, actigraphic sleep indices, and their relationships with acute mountain sickness (AMS during very HA exposure, acclimatization, and re-exposure.Methods: A total of 21 healthy altitude-naive individuals (25 ± 4 years; 13 females completed 2 cycles of altitude exposure separated by 7 days at low altitude (LA, 520 m. Participants slept at 2900 m and spent the day at HA, (5050 m. We report acute altitude exposure on Day 1 (LA vs. HA1 and after 6 days of acclimatization (HA1 vs. HA6. Vigilance was quantified by reaction speed in the 10-min psychomotor vigilance test reaction speed (PVT-RS. AMS was evaluated using the Environmental Symptoms Questionnaire Cerebral Score (AMS-C score. Nocturnal rest/activity was recorded to estimate sleep duration using actigraphy.Results: In Cycle 1, PVT-RS was slower at HA1 compared to LA (4.1 ± 0.8 vs. 4.5 ± 0.6 s-1, respectively, p = 0.029, but not at HA6 (4.6 ± 0.7; p > 0.05. In Cycle 2, PVT-RS at HA1 (4.6 ± 0.7 and HA6 (4.8 ± 0.6 were not different from LA (4.8 ± 0.6, p > 0.05 and significantly greater than corresponding values in Cycle 1. In both cycles, AMS scores were higher at HA1 than at LA and HA6 (p < 0.05. Estimated sleep durations (TST at LA, 1st and 5th nights were 431.3 ± 28.7, 418.1 ± 48.6, and 379.7 ± 51.4 min, respectively, in Cycle 1 and they were significantly reduced during acclimatization exposures (LA vs. 1st night, p > 0.05; LA vs. 5th night, p = 0.012; and 1st vs. 5th night, p = 0.054. LA, 1st and 5th nights TST in Cycle 2 were 477.5 ± 96.9, 430.9 ± 34, and 341.4 ± 32.2, respectively, and we observed similar deteriorations in TST as in Cycle 1 (LA vs. 1st night, p > 0.05; LA vs. 5th night, p = 0.001; and 1st vs. 5th night, p < 0.0001. At HA1, subjects who reported higher AMS-C scores exhibited slower

  6. Repeated exposure to two stressors in sequence demonstrates that corticosterone and paraventricular nucleus of the hypothalamus interleukin-1β responses habituate independently.

    Science.gov (United States)

    Lovelock, D F; Deak, T

    2017-09-01

    A wide range of stress-related pathologies such as post-traumatic stress disorder are considered to arise from aberrant or maladaptive forms of stress adaptation. The hypothalamic-pituitary-adrenal (HPA) axis readily adapts to repeated stressor exposure, yet little is known about adaptation in neuroimmune responses to repeated or sequential stress challenges. In Experiment 1, rats were exposed to 10 days of restraint alone (60 minutes daily), forced swim alone (30 minutes daily) or daily sequential exposure to restraint (60 minutes) followed immediately by forced swim (30 minutes), termed sequential stress exposure. Habituation of the corticosterone (CORT) response occurred to restraint by 5 days and swim at 10 days, whereas rats exposed to sequential stress exposure failed to display habituation to the combined challenge. Experiment 2 compared 1 or 5 days of forced swim with sequential stress exposure and examined how each affected expression of several neuroimmune and cellular activation genes in the paraventricular nucleus of the hypothalamus (PVN), prefrontal cortex (PFC) and hippocampus (HPC). Sequential exposure to restraint and swim increased interleukin (IL)-1β in the PVN, an effect that was attenuated after 5 days. Sequential stress exposure also elicited IL-6 and tumour necrosis factor-α responses in the HPC and PFC, respectively, which did not habituate after 5 days. Experiment 3 tested whether prior habituation to restraint (5 days) would alter the IL-1β response evoked by swim exposure imposed immediately after the sixth day of restraint. Surprisingly, a history of repeated exposure to restraint attenuated the PVN IL-1β response after swim in comparison to acutely-exposed subjects despite an equivalent CORT response. Overall, these findings suggest that habituation of neuroimmune responses to stress proceeds: (i) independent of HPA axis habituation; (ii) likely requires more daily sessions of stress to develop; and (iii) IL-1β displays

  7. Effects of moxifloxacin exposure on the conjunctival flora and antibiotic resistance profile following repeated intravitreal injections

    Directory of Open Access Journals (Sweden)

    Mustafa Ataş

    2014-10-01

    Full Text Available AIM:To evaluate the effects of moxifloxacin exposure on the conjunctival flora and antibiotic resistance profile following repeated intravitreal injections.METHODS:Seventy-two eyes of 36 patients [36 eyes in control group, 36 eyes in intravitreal injection (IVI group] were enrolled in the study. All the eyes had at least one IVI and had diabetic macular edema (DME or age-related macular degeneration (ARMD. Moxifloxacin was prescribed to all the patients four times a day for five days following injection. Conjunctival cultures were obtained from the lower fornix via standardized technique with every possible effort made to minimize contamination from the lids, lashes, or skin. Before the application of any ophthalmic medication, conjunctival cultures were obtained from both eyes using sterile cotton culture. An automated microbiology system was used to identify the growing bacteria and determine antibiotic sensitivity. RESULTS:The bacterial cultures were isolated from 72 eyes of 36 patients, sixteen of whom patients (44.4% were male and twenty (55.6% were female. Average age was 68.4±9.0 (range 50-86. The average number of injections before taking cultures was 3.1+1.0. Forty-eight (66.7% of 72 eyes had at least one significant organism. There was no bacterial growth in 8 (20.5% of IVI eyes and in 16 (44.4% of control eyes (P=0.03. Of the bacteria isolated from culture, 53.8% of coagulase negative staphylococci (CoNS in IVI eyes and 47.2% CoNS in control eyes. This difference between IVI eyes and control eyes about bacteria isolated from culture was not statistically significant (P=0.2. Eleven of 25 bacteria (44.0% isolated from IVI eyes and 11 (57.9% of 19 bacteria isolated from control eyes were resistant to oxacillin. The difference in frequency of moxifloxacine resistance between two groups was not statistically significant (12.0% in IVI eyes and 21.1% in control eyes (P=0.44. There were no cases of resistance to vancomycin, teicoplanin and

  8. Long-term repeatability of the skin prick test is high when supported by history or allergen-sensitivity tests

    DEFF Research Database (Denmark)

    Bødtger, Uffe; Jacobsen, C R; Poulsen, L K

    2003-01-01

    subjects. An SPT was positive when > or =3 mm, and repeatable if either persistently positive or negative. Clinical sensitivity to birch pollen was used as model for inhalation allergy, and was investigated at inclusion and at study termination by challenge tests, intradermal test, titrated SPT and Ig......E measurements. Birch pollen symptoms were confirmed in diaries. RESULTS: The repeatability of a positive SPT was 67%, increasing significantly to 100% when supported by the history. When not supported by history, the presence of specific IgE was significantly associated with a repeatable SPT. Allergen....... CONCLUSION: SPT changes are clinically relevant. Further studies using other allergens are needed. Long-term repeatability of SPT is high in the presence of a supportive history....

  9. 'Just a pinch of salt'. An experimental comparison of the effect of repeated exposure and flavor-flavor learning with salt or spice on vegetable acceptance in toddlers.

    Science.gov (United States)

    Bouhlal, Sofia; Issanchou, Sylvie; Chabanet, Claire; Nicklaus, Sophie

    2014-12-01

    Children's vegetable intake is below the recommended amounts. No studies to date have tested the relevance of using salt or spices to increase children's vegetable acceptance. Our objective was to compare the effect of repeated exposure (RE) and of flavor-flavor learning (FFL) on toddlers' acceptance of a non-familiar vegetable. Two unconditioned stimuli were used: salt and a salt-associated spice. Toddlers attending six nurseries were assigned to 3 groups in a between subject design. Groups were exposed 8 times to a basic salsify puree (0.2% salt w/w; RE group; n = 47), a salty salsify puree (0.5% salt w/w; FFL-Salt group; n = 54) or a spiced salsify puree (0.2% salt and 0.02% nutmeg w/w; FFL-Nutmeg group; n = 50). Acceptance (intake and liking) of the target vegetable (basic salsify puree) and of a control vegetable (carrot puree) was evaluated at pre-exposure, at each exposure of the learning period, at post-exposure, and at 1, 3 and 6 months after exposure. In all groups, intake of the target vegetable increased from pre- to post-exposure. This increase was significantly higher in the RE group (64 ± 11 g) than in the FFL-Salt group (23 ± 11 g) and marginally higher than in the FFL-Nutmeg group (36 ± 11 g). No difference between groups was observed on the increase in liking of the target vegetable from pre- to post-exposure. The increase of the target vegetable intake was still observed after 6 months for all groups. Thus, repeated exposure appears to be the simplest choice to increase vegetable intake on the short and long term in toddlers. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Repeated exposure to cat urine induces complex behavioral, hormonal, and c-fos mRNA responses in Norway rats ( Rattus norvegicus)

    Science.gov (United States)

    Yin, Baofa; Gu, Chen; Lu, Yi; Hegab, Ibrahim M.; Yang, Shengmei; Wang, Aiqin; Wei, Wanhong

    2017-08-01

    Prey species show specific adaptations that allow recognition, avoidance, and defense against predators. This study was undertaken to investigate the processing of a chronic, life-threatening stimulus to Norway rats ( Rattus norvegicus). One hundred forty-four Norway rats were tested by repeated presentation of cat urine for 1 h at different days in a defensive withdrawal apparatus. Rats exposed to urine for short periods showed significantly larger defensive behavioral and medial hypothalamic c-fos messenger RNA (mRNA) responses than other groups. These defensive responses habituated shortly after the presentation of cat urine. Serum levels of adrenocorticotropic hormone and corticosterone increased significantly when animals were repeatedly exposed to cat urine. However, the hormonal responses took longer to habituate than the behavioral and molecular responses did. We conclude that the behavioral and c-fos mRNA responses are "primed" for habituation to repeated exposures to cat urine, while the hormonal responses show "resistance." The results support our hypothesis that the strongest anti-predator responses at three levels would occur during short-term exposure to cat urine and that these responses would subsequently disappear on prolonged exposure. This study assists understanding the way in which the different levels of defensive responses are integrated and react during chronic stress.

  11. Realistic evaluation of tester exposure based on Florida testing experience

    International Nuclear Information System (INIS)

    Schreiber, R.A.

    1990-01-01

    This paper reports on a radon decay product exposure model for Florida Certified Radon Measurement Technicians that has been formulated based on the guidance of 10CFR20. This model was used to estimate the exposure of 44 Florida measurement technicians from January through November of 1989. Comparing estimated testing and home exposure shows that 100% of the technicians observed received more exposure in the home than during testing activities. Exposure during normal office hours also exceed testing exposure in 86% of the technicians observed. Health and safety exposure data for radon measurement technicians does not follow the standard concepts of occupational radiation exposure normally accepted in 10CFR20

  12. Development of a REBCO HTS magnet for Maglev - repeated bending tests of HTS pancake coils -

    Science.gov (United States)

    Sugino, Motohikoa; Mizuno, Katsutoshi; Tanaka, Minoru; Ogata, Masafumi

    2018-01-01

    In the past study, two manufacturing methods were developed that can manufacture pancake coils by using REBCO coated conductors. It was confirmed that the conductors have no electric degradation that caused by the manufacturing method. The durability evaluation tests of the pancake coils were conducted as the final evaluation of the coil manufacturing method in this study. The repeated bending deformation was applied to manufactured pancake coils in the tests. As the results of these tests, it was confirmed that the pancake coils that were manufactured by two methods had the durability for the repeated bending deformation and the coils maintained the appropriate mechanical performance and electric performance. We adopted the fusion bonding method as the coil manufacturing method of the HTS magnet Furthermore, using the prototype pancake coil that was manufactured by the fusion bonding method as a test sample, the repeated bending test under the exited condition was conducted. Thus it was confirmed that the coil manufactured by the fusion bonding method has no degradation of the electricity performance and the mechanical properties even if the repeated bending deformation was applied under the exited condition.

  13. Dermal damage promoted by repeated low-level UV-A1 exposure despite tanning response in human skin.

    Science.gov (United States)

    Wang, Frank; Smith, Noah R; Tran, Bao Anh Patrick; Kang, Sewon; Voorhees, John J; Fisher, Gary J

    2014-04-01

    Solar UV irradiation causes photoaging, characterized by fragmentation and reduced production of type I collagen fibrils that provide strength to skin. Exposure to UV-B irradiation (280-320 nm) causes these changes by inducing matrix metalloproteinase 1 and suppressing type I collagen synthesis. The role of UV-A irradiation (320-400 nm) in promoting similar molecular alterations is less clear yet important to consider because it is 10 to 100 times more abundant in natural sunlight than UV-B irradiation and penetrates deeper into the dermis than UV-B irradiation. Most (approximately 75%) of solar UV-A irradiation is composed of UV-A1 irradiation (340-400 nm), which is also the primary component of tanning beds. To evaluate the effects of low levels of UV-A1 irradiation, as might be encountered in daily life, on expression of matrix metalloproteinase 1 and type I procollagen (the precursor of type I collagen). In vivo biochemical analyses were conducted after UV-A1 irradiation of normal human skin at an academic referral center. Participants included 22 healthy individuals without skin disease. Skin pigmentation was measured by a color meter (chromometer) under the L* variable (luminescence), which ranges from 0 (black) to 100 (white). Gene expression in skin samples was assessed by real-time polymerase chain reaction. Lightly pigmented human skin (L* >65) was exposed up to 4 times (1 exposure/d) to UV-A1 irradiation at a low dose (20 J/cm2), mimicking UV-A levels from strong sun exposure lasting approximately 2 hours. A single exposure to low-dose UV-A1 irradiation darkened skin slightly and did not alter matrix metalloproteinase 1 or type I procollagen gene expression. With repeated low-dose UV-A1 irradiation, skin darkened incrementally with each exposure. Despite this darkening, 2 or more exposures to low-dose UV-A1 irradiation significantly induced matrix metalloproteinase 1 gene expression, which increased progressively with successive exposures. Repeated UV-A1

  14. Microprocessor-controlled inhalation system for repeated exposure of animals to aerosols

    International Nuclear Information System (INIS)

    Carpenter, R.L.; Barr, F.P.; Leydig, R.L.; Rajala, R.E.

    1979-01-01

    A microprocessor-controlled inhalation exposure system (MCIES) has been built to automate aerosol generation and sampling while controlling exposure time for animal toxicity studies. The system has a time resolution of 0.1 s and automatically sequences the exposure events from initiation to temination of the exposure. The operator is required to preset all airflows, read in a paper tape containing the time sequence of events, and initiate the automatic sequence by closing a switch

  15. Evaluation of Patients with an Apparent False Positive Stool DNA Test: The Role of Repeat Stool DNA Testing.

    Science.gov (United States)

    Cooper, Gregory S; Markowitz, Sanford D; Chen, Zhengyi; Tuck, Missy; Willis, Joseph E; Berger, Barry M; Brenner, Dean E; Li, Li

    2018-03-07

    There is uncertainty as to the appropriate follow-up of patients who test positive on multimarker stool DNA (sDNA) testing and have a colonoscopy without neoplasia. To determine the prevalence of missed colonic or occult upper gastrointestinal neoplasia in patients with an apparent false positive sDNA. We prospectively identified 30 patients who tested positive with a commercially available sDNA followed by colonoscopy without neoplastic lesions. Patients were invited to undergo repeat sDNA at 11-29 months after the initial test followed by repeat colonoscopy and upper endoscopy. We determined the presence of neoplastic lesions on repeat evaluation stratified by results of repeat sDNA. Twelve patients were restudied. Seven patients had a negative second sDNA test and a normal second colonoscopy and upper endoscopy. In contrast, 5 of 12 subjects had a persistently positive second sDNA test, and 3 had positive findings, including a 3-cm sessile transverse colon adenoma with high-grade dysplasia, a 2-cm right colon sessile serrated adenoma with dysplasia, and a nonadvanced colon adenoma (p = 0.045). These corresponded to a positive predictive value of 0.60 (95% CI 0.17-1.00) and a negative predictive value of 1.00 (95% CI 1.00-1.00) for the second sDNA test. In addition, the medical records of all 30 subjects with apparent false positive testing were reviewed and no documented cases of malignant tumors were recorded. Repeat positive sDNA testing may identify a subset of patients with missed or occult colorectal neoplasia after negative colonoscopy for an initially positive sDNA. High-quality colonoscopy with careful attention to the right colon in patients with positive sDNA is critically important and may avoid false negative colonoscopy.

  16. Cumulative effects of repeated exposure to pO2 = 200 kPa (2 atm).

    Science.gov (United States)

    Shykoff, Barbara E

    2014-01-01

    Even asymptomatic exposures to elevated oxygen partial pressure (pO2) can influence subsequent exposures. Dry chamber dives of three hours' duration at pO2 of 200 kPa were conducted to examine cumulative effects. Experiments were single (n = 27), or paired exposures with surface intervals (SIs) 15 to 17 hours (n = 30), six hours (n = 33), or three hours (n = 36). Flow-volume loops, diffusing capacity, and symptoms were recorded before and after exposures. Immediately after surfacing from second exposures, some significant (p < 0.05) mean changes from baseline in pulmonary function indices occurred for all SIs and persisted for two days for three-hour SIs and for one day for 15-hour SIs. Incidences of symptoms were 15% immediately after one exposure and 28%, 38% and 31% immediately after a second exposure following 15-, six- , or three-hour SIs, respectively. Incidences of changes in pulmonary function indices (deltaPF) were 5%, 11%, 12% and 14% for single exposures or two with 15-, six-, or three-hour SIs, respectively. Two days following the second exposure, resolution of symptoms was incomplete after six- or 15-hour SIs, as was resolution of deltaPF after 15-hour SIs. The incidences indicate non-linear superposition of effects of a first and second exposure, and are not readily explained by delayed-onset injury.

  17. Hearing loss associated with repeated MRI acquisition procedure-related acoustic noise exposure: an occupational cohort study.

    Science.gov (United States)

    Bongers, Suzan; Slottje, Pauline; Kromhout, Hans

    2017-11-01

    To study the effects of repeated exposure to MRI-related acoustic noise during image acquisition procedures (scans) on hearing. A retrospective occupational cohort study was performed among workers of an MRI manufacturing facility (n=474). Longitudinal audiometry data from the facility's medical surveillance scheme collected from 1973 to 2010 were analysed by studying the association of cumulative exposure to MRI-related acoustic noise from voluntary (multiple) MRI scans and the hearing threshold of the volunteer. Repeated acoustic noise exposure during volunteer MRI scans was found to be associated with a small exposure-dependent increased rate change of hearing threshold level (dB/year), but the association was only found related to the number of voluntary MRI scans and not to modelled cumulative noise exposure (dB*hour) based on MRI-system type. The increased rate change of hearing threshold level was found to be statistically significant for the frequencies 500, 1000, 2000, 3000 and 4000 Hz in the right ear. From our longitudinal cohort study, it appeared that exposure to noise from voluntarily MRI scans may have resulted in a slight amount of hearing loss. Mandatory use of hearing protection might have prevented more severe hearing loss. Lack of consistency in findings between the left and right ears and between the two exposure measures prohibits definitive conclusions. Further research that addresses the study's methodological limitations is warranted to corroborate our findings. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  18. Relationships Among Two Repeated Activity Tests and Aerobic Fitness of Volleyball Players.

    Science.gov (United States)

    Meckel, Yoav; May-Rom, Moran; Ekshtien, Aya; Eisenstein, Tamir; Nemet, Dan; Eliakim, Alon

    2015-08-01

    The purpose of the study was to determine performance indices of a repeated sprint test (RST) and to examine their relationships with performance indices of a repeated jump test (RJT) and with aerobic fitness among trained volleyball players. Sixteen male volleyball players performed RST (6 × 30 m sprints), RJT (6 sets of 6 consecutive jumps), and an aerobic power test (20-m Shuttle Run Test). Performance indices for the RST and the RJT were (a) the ideal 30-m run time (IS), the total run time (TS) of the 6 sprints, and the performance decrement (PD) during the test and (b) the ideal jump height (IJ), the total jump height (TJ) of all the jumps, and the PD during the test, respectively. No significant correlations were found between performance indices of the RST and RJT. Significant correlations were found between PD, IS, and TS in the RST protocol and predicted peak V[Combining Dot Above]O2 (r = -0.60, -0.75, -0.77, respectively). No significant correlations were found between performance indices of the RJT (IJ, TJ, and PD) and peak V[Combining Dot Above]O2. The findings suggest that a selection of repeated activity test protocols should acknowledge the specific technique used in the sport, and that a distinct RJT, rather than the classic RST, is more appropriate for assessing the anaerobic capabilities of volleyball players. The findings also suggest that aerobic fitness plays only a minor role in performance maintenance throughout characteristic repeated jumping activity of a volleyball game.

  19. Repeatability of an automated Landolt C test, compared with the early treatment of diabetic retinopathy study (ETDRS) chart testing.

    Science.gov (United States)

    Ruamviboonsuk, Paisan; Tiensuwan, Montip; Kunawut, Catleya; Masayaanon, Patcharapim

    2003-10-01

    To evaluate the repeatability of visual acuity scores from the automated test and compare them with the Early Treatment of Diabetic Retinopathy Study (ETDRS) chart. Instrument validation study based on a model of repeatability study in two observations. SMETHODS: a prospective, clinic-based, comparative study. A total of 206 participants without ocular diseases and refractive errors in their right eyes were randomly enrolled in the automated group in which 107 participants performed the automated test and the ETDRS group in which 99 participants read the ETDRS chart. All participants were tested with only their right eyes without corrections at 4 meters and came back to have the same tests 1 week later. The automated test used the Landolt rings as optotypes and was conducted by a low-ended personal computer with a 15-inch monitor and a wireless keyboard. The "letter" score calculated by counting every correct response to optotypes, and the "threshold curve" score interpreted from the optotype size at the midpoint of a visual acuity threshold curve. The 95% confidence interval of test-retest of visual acuity scores from the automated test are comparable to the ETDRS chart (.143 compared with.125 for letter scores,.145 compared with.122 for threshold curve scores). The score repeatabilities, calculated from the standard deviations of test-retest, from the automated test are also comparable to the ETDRS chart (.201 compared with.177 for letter scores,.206 compared with.172 for threshold curve scores). All comparisons demonstrated no statistical difference (P >.05). The automated testing system in this study enables practical measuring visual acuity by the Landolt rings. The system's repeatability, which is comparable to the ETDRS chart, supports its role as an alternative tool for measuring outcome in new clinical research. Its ability to practically generate visual acuity threshold curves may also be useful in future clinical research studies.

  20. Perspectives on repeated low-level blast and the measurement of neurotrauma in humans as an occupational exposure risk

    Science.gov (United States)

    Carr, W.; Dell, K. C.; Yanagi, M. A.; Hassan, D. M.; LoPresti, M. L.

    2017-11-01

    A pressing question in military medical research is the nature and degree of effects on the human brain from occupational repeated exposure to low-level explosive blast, but reliable and effective means to objectively measure such effects remain elusive. In survey results, headache, difficulty sleeping, irritability, cognitive impairment, and a variety of other symptoms consistent with post-concussive syndrome have been reported by those exposed to blast and there was positive correlation between degree of blast exposure and degree of symptomology, but an important goal is to obtain more objective evidence of an effect than self-report alone. This review reflects recent efforts to measure and evaluate such hypothesized effects and current recommendations for ongoing study. Optimal measures are likely those with sensitivity and specificity to systemic effects in mild neurotrauma, that have minimal to no volitional component, and that can be sampled relatively quickly with minimal intrusion in prospective, observational field studies during routine training with explosives. An understanding of an association between parameters of exposure to repeated low-level blast and negative neurologic effects would support the evaluation of clinical implications and development of protective equipment and surveillance protocols where warranted. At present, low-level blast exposure surveillance measurements do not exist as a systematic record for any professional community.

  1. Effects of repeated exposure to malathion on growth, food consumption, and locomotor performance of the western fence lizard (Sceloporus occidentalis)

    Energy Technology Data Exchange (ETDEWEB)

    Holem, Ryan R. [University of Georgia, Savannah River Ecology Laboratory, Aiken, SC 29801 (United States); ENTRIX, Inc., Okemos, MI 48864 (United States); Hopkins, William A. [University of Georgia, Savannah River Ecology Laboratory, Aiken, SC 29801 (United States); Department of Fisheries and Wildlife Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States)], E-mail: hopkinsw@vt.edu; Talent, Larry G. [Natural Resource Ecology and Management, Oklahoma State University, Stillwater, OK 74078 (United States)

    2008-03-15

    Effects of repeated pollutant exposure on growth, locomotor performance, and behavior have rarely been evaluated in reptiles. We administered three doses of malathion (2.0, 20, or 100 mg/kg body weight) to western fence lizards (Sceloporus occidentalis) over an 81 day period. Eight and 23% mortality occurred at 20 and 100 mg/kg (p = 0.079) and 85% of lizards in the 100 mg/kg group exhibited clinical symptoms of poisoning. Growth, food consumption, body condition index, and terrestrial locomotor performance were not significantly influenced by malathion. However, arboreal sprint velocity was significantly reduced in lizards receiving 100 mg/kg. Fifty percent of lizards in the 100 mg/kg group also refused to sprint in the arboreal setting (p = 0.085). Based on these results, arboreal locomotor performance was the most sensitive metric of exposure we evaluated. Further study of compounds such as malathion is warranted due to highly variable application rates and exposure scenarios. - Repeated exposure of western fence lizards to malathion caused reduced arboreal performance and some mortality but growth, food consumption, and terrestrial performance were not affected.

  2. Effects of repeated exposure to malathion on growth, food consumption, and locomotor performance of the western fence lizard (Sceloporus occidentalis)

    International Nuclear Information System (INIS)

    Holem, Ryan R.; Hopkins, William A.; Talent, Larry G.

    2008-01-01

    Effects of repeated pollutant exposure on growth, locomotor performance, and behavior have rarely been evaluated in reptiles. We administered three doses of malathion (2.0, 20, or 100 mg/kg body weight) to western fence lizards (Sceloporus occidentalis) over an 81 day period. Eight and 23% mortality occurred at 20 and 100 mg/kg (p = 0.079) and 85% of lizards in the 100 mg/kg group exhibited clinical symptoms of poisoning. Growth, food consumption, body condition index, and terrestrial locomotor performance were not significantly influenced by malathion. However, arboreal sprint velocity was significantly reduced in lizards receiving 100 mg/kg. Fifty percent of lizards in the 100 mg/kg group also refused to sprint in the arboreal setting (p = 0.085). Based on these results, arboreal locomotor performance was the most sensitive metric of exposure we evaluated. Further study of compounds such as malathion is warranted due to highly variable application rates and exposure scenarios. - Repeated exposure of western fence lizards to malathion caused reduced arboreal performance and some mortality but growth, food consumption, and terrestrial performance were not affected

  3. Secondhand tobacco smoke exposure and heart rate variability and inflammation among non-smoking construction workers: a repeated measures study.

    Science.gov (United States)

    Zhang, Jinming; Fang, Shona C; Mittleman, Murray A; Christiani, David C; Cavallari, Jennifer M

    2013-10-02

    Although it has been well recognized that exposure to secondhand tobacco smoke (SHS) is associated with cardiovascular mortality, the mechanisms and time course by which SHS exposure may lead to cardiovascular effects are still being explored. Non-smoking workers were recruited from a local union and monitored inside a union hall while exposed to SHS over approximately 6 hours. Participants were fitted with a continuous electrocardiographic monitor upon enrollment which was removed at the end of a 24-hr monitoring period. A repeated measures study design was used where resting ECGs and blood samples were taken from individuals before SHS exposure (baseline), immediately following SHS exposure (post) and the morning following SHS exposure (next-morning).Inflammatory markers, including high sensitivity C-reactive protein (CRP) and white blood cell count (WBC) were analyzed. Heart rate variability (HRV) was analyzed from the ECG recordings in time (SDNN, rMSSD) and frequency (LF, HF) domain parameters over 5-minute periods. SHS exposure was quantified using a personal fine particulate matter (PM2.5) monitor.Linear mixed effects regression models were used to examine within-person changes in inflammatory and HRV parameters across the 3 time periods. Exposure-response relationships with PM2.5 were examined using mixed effects models. All models were adjusted for age, BMI and circadian variation. A total of 32 male non-smokers were monitored between June 2010 and June 2012. The mean PM2.5 from SHS exposure was 132 μg/m3. Immediately following SHS exposure, a 100 μg/m3 increase in PM2.5 was associated with declines in HRV (7.8% [standard error (SE) =3%] SDNN, 8.0% (SE = 3.9%) rMSSD, 17.2% (SE = 6.3%) LF, 29.0% (SE = 10.1%) HF) and increases in WBC count 0.42 (SE = 0.14) k/μl. Eighteen hours following SHS exposure, a 100 μg/m3 increase in PM2.5 was associated with 24.2% higher CRP levels. Our study suggest that short-term SHS exposure is associated

  4. Hysteresis analysis of graphene transistor under repeated test and gate voltage stress

    International Nuclear Information System (INIS)

    Yang Jie; Jia Kunpeng; Su Yajuan; Zhao Chao; Chen Yang

    2014-01-01

    The current transport characteristic is studied systematically based on a back-gate graphene field effect transistor, under repeated test and gate voltage stress. The interface trapped charges caused by the gate voltage sweep process screens the gate electric field, and results in the neutral point voltage shift between the forth and back sweep direction. In the repeated test process, the neutral point voltage keeps increasing with test times in both forth and back sweeps, which indicates the existence of interface trapped electrons residual and accumulation. In gate voltage stress experiment, the relative neutral point voltage significantly decreases with the reducing of stress voltage, especially in −40 V, which illustrates the driven-out phenomenon of trapped electrons under negative voltage stress. (semiconductor devices)

  5. 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

  6. Radiation dose exposure in patients affected by lymphoma undergoing repeat CT examinations: how to manage the radiation dose variability.

    Science.gov (United States)

    Paolicchi, Fabio; Bastiani, Luca; Guido, Davide; Dore, Antonio; Aringhieri, Giacomo; Caramella, Davide

    2018-03-01

    To assess the variability of radiation dose exposure in patients affected by lymphoma undergoing repeat CT (computed tomography) examinations and to evaluate the influence of different scan parameters on the overall radiation dose. A series of 34 patients (12 men and 22 women with a median age of 34.4 years) with lymphoma, after the initial staging CT underwent repeat follow-up CT examinations. For each patient and each repeat examination, age, sex, use of AEC system (Automated Exposure Control, i.e. current modulation), scan length, kV value, number of acquired scans (i.e. number of phases), abdominal size diameter and dose length product (DLP) were recorded. The radiation dose of just one venous phase was singled out from the DLP of the entire examination. All scan data were retrieved by our PACS (Picture Archiving and Communication System) by means of a dose monitoring software. Among the variables we considered, no significant difference of radiation dose was observed among patients of different ages nor concerning tube voltage. On the contrary the dose delivered to the patients varied depending on sex, scan length and usage of AEC. No significant difference was observed depending on the behaviour of technologists, while radiologists' choices had indirectly an impact on the radiation dose due to the different number of scans requested by each of them. Our results demonstrate that patients affected by lymphoma who undergo repeat whole body CT scanning may receive unnecessary overexposure. We quantified and analyzed the most relevant variables in order to provide a useful tool to manage properly CT dose variability, estimating the amount of additional radiation dose for every single significant variable. Additional scans, incorrect scan length and incorrect usage of AEC system are the most relevant cause of patient radiation exposure.

  7. Repeated CT scans in trauma transfers: An analysis of indications, radiation dose exposure, and costs

    International Nuclear Information System (INIS)

    Hinzpeter, Ricarda; Sprengel, Kai; Wanner, Guido A.; Mildenberger, Peter; Alkadhi, Hatem

    2017-01-01

    Highlights: • Repetition of CT in trauma patients occurs relatively often. • Repetition of CT is mainly caused by inadequate image data transfer. • Potentially preventable CT examinations add radiation dose to patients. • Repeated CT is associated with excess costs to the health care system. - Abstract: Objectives: To identify the number of CT scans repeated in acute trauma patients receiving imaging before being referred to a trauma center, to define indications, and to assess radiation doses and costs of repeated CT. Methods: This retrospective study included all adult trauma patients transferred from other hospitals to a Level-I trauma center during 2014. Indications for repeated CT scans were categorized into: inadequate CT image data transfer, poor image quality, repetition of head CT after head injury together with completion to whole-body CT (WBCT), and follow-up of injury known from previous CT. Radiation doses from repeated CT were determined; costs were calculated using a nation-wide fee schedule. Results: Within one year, 85/298 (28.5%) trauma patients were transferred from another hospital because of severe head injury (n = 45,53%) and major body trauma (n = 23;27%) not manageable in the referring hospital, repatriation from a foreign country (n = 14;16.5%), and no ICU-capacity (n = 3;3.5%). Of these 85 patients, 74 (87%) had repeated CT in our center because of inadequate CT data transfer (n = 29;39%), repetition of head CT with completion to WBCT (n = 24;32.5%), and follow-up of known injury (n = 21;28.5%). None occurred because of poor image quality. Cumulative dose length product (DLP) and annual costs of potential preventable, repeated CT (inadequate data transfer) was 631mSv (81′304mGy*cm) and 35′233€, respectively. Conclusion: A considerable number of transferred trauma patients undergo potentially preventable, repeated CT, adding radiation dose to patients and costs to the health care system.

  8. Repeated CT scans in trauma transfers: An analysis of indications, radiation dose exposure, and costs

    Energy Technology Data Exchange (ETDEWEB)

    Hinzpeter, Ricarda, E-mail: Ricarda.Hinzpeter@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistr. 100, Zurich CH-8091 (Switzerland); Sprengel, Kai, E-mail: Kai.Sprengel@usz.ch [Division of Trauma Surgery, Department of Surgery, University Hospital Zurich, University of Zurich, Raemistr. 100, CH-8091 Zurich (Switzerland); Wanner, Guido A., E-mail: Guido.Wanner@sbk-vs.de [Division of Trauma Surgery, Department of Surgery, University Hospital Zurich, University of Zurich, Raemistr. 100, CH-8091 Zurich (Switzerland); Department of General Surgery, Schwarzwald-Baar Klinikum, University of Freiburg, Klinikstr. 11, D-78052 Villingen-Schwenningen (Germany); Mildenberger, Peter, E-mail: peter.mildenberger@unimedizin-mainz.de [Department of Diagnostic and Interventional Radiology, University Hospital of Mainz, Langenbeckstr. 1, D-55131 Mainz (Germany); Alkadhi, Hatem, E-mail: hatem.alkadhi@usz.ch [Institute of Diagnostic and Interventional Radiology, University Hospital Zurich, University of Zurich, Raemistr. 100, Zurich CH-8091 (Switzerland)

    2017-03-15

    Highlights: • Repetition of CT in trauma patients occurs relatively often. • Repetition of CT is mainly caused by inadequate image data transfer. • Potentially preventable CT examinations add radiation dose to patients. • Repeated CT is associated with excess costs to the health care system. - Abstract: Objectives: To identify the number of CT scans repeated in acute trauma patients receiving imaging before being referred to a trauma center, to define indications, and to assess radiation doses and costs of repeated CT. Methods: This retrospective study included all adult trauma patients transferred from other hospitals to a Level-I trauma center during 2014. Indications for repeated CT scans were categorized into: inadequate CT image data transfer, poor image quality, repetition of head CT after head injury together with completion to whole-body CT (WBCT), and follow-up of injury known from previous CT. Radiation doses from repeated CT were determined; costs were calculated using a nation-wide fee schedule. Results: Within one year, 85/298 (28.5%) trauma patients were transferred from another hospital because of severe head injury (n = 45,53%) and major body trauma (n = 23;27%) not manageable in the referring hospital, repatriation from a foreign country (n = 14;16.5%), and no ICU-capacity (n = 3;3.5%). Of these 85 patients, 74 (87%) had repeated CT in our center because of inadequate CT data transfer (n = 29;39%), repetition of head CT with completion to WBCT (n = 24;32.5%), and follow-up of known injury (n = 21;28.5%). None occurred because of poor image quality. Cumulative dose length product (DLP) and annual costs of potential preventable, repeated CT (inadequate data transfer) was 631mSv (81′304mGy*cm) and 35′233€, respectively. Conclusion: A considerable number of transferred trauma patients undergo potentially preventable, repeated CT, adding radiation dose to patients and costs to the health care system.

  9. Study of Optimal Perimetric Testing in Children (OPTIC: Feasibility, Reliability and Repeatability of Perimetry in Children.

    Directory of Open Access Journals (Sweden)

    Dipesh E Patel

    Full Text Available To investigate feasibility, reliability and repeatability of perimetry in children.A prospective, observational study recruiting 154 children aged 5-15 years, without an ophthalmic condition that affects the visual field (controls, identified consecutively between May 2012 and November 2013 from hospital eye clinics. Perimetry was undertaken in a single sitting, with standardised protocols, in a randomised order using the Humphrey static (SITA 24-2 FAST, Goldmann and Octopus kinetic perimeters. Data collected included test duration, subjective experience and test quality (incorporating examiner ratings on comprehension of instructions, fatigue, response to visual and auditory stimuli, concentration and co-operation to assess feasibility and reliability. Testing was repeated within 6 months to assess repeatability.Overall feasibility was very high (Goldmann=96.1%, Octopus=89% and Humphrey=100% completed the tests. Examiner rated reliability was 'good' in 125 (81.2% children for Goldmann, 100 (64.9% for Octopus and 98 (63.6% for Humphrey perimetry. Goldmann perimetry was the most reliable method in children under 9 years of age. Reliability improved with increasing age (multinomial logistic regression (Goldmann, Octopus and Humphrey, p<0.001. No significant differences were found for any of the three test strategies when examining initial and follow-up data outputs (Bland-Altman plots, n=43, suggesting good test repeatability, although the sample size may preclude detection of a small learning effect.Feasibility and reliability of formal perimetry in children improves with age. By the age of 9 years, all the strategies used here were highly feasible and reliable. Clinical assessment of the visual field is achievable in children as young as 5 years, and should be considered where visual field loss is suspected. Since Goldmann perimetry is the most effective strategy in children aged 5-8 years and this perimeter is no longer available, further

  10. Repeat HIV testing during pregnancy and delivery: missed opportunities in a rural district hospital in Zambia.

    Science.gov (United States)

    Heemelaar, Steffie; Habets, Nicole; Makukula, Ziche; van Roosmalen, Jos; van den Akker, Thomas

    2015-03-01

    To assess coverage of repeat HIV testing among women who delivered in a Zambian hospital. HIV testing of pregnant women and repeat testing every 3 months during pregnancy and breastfeeding is the recommended policy in areas of high HIV prevalence. A prospective implementation study in a second-level hospital in rural Zambia. Included were all pregnant women who delivered in hospital during May and June 2012. Data regarding antenatal visits and HIV testing were collected by two investigators using a standardised form. Of 401 women who delivered in hospital, sufficient antenatal data could be retrieved for 322 (80.3%) women. Of these 322 women, 301 (93.5%) had attended antenatal care (ANC) at least once. At the time of discharge after delivery in hospital, 171 (53.1%) had an unclear HIV status because their negative test result was more than 3 months ago or of an unknown date, or because they had not been tested at all during pregnancy or delivery. An updated HIV status was present for 151 (46.9%) women: 25 (7.8%) were HIV positive and 126 (39.1%) had tested negative within the last 3 months. In this last group, 79 (24.5%) had been tested twice or more during pregnancy. During the study period, none of the women was tested during admission for delivery. Despite high ANC coverage, opportunities for repeat HIV testing were missed in almost half of all women who delivered in this hospital in a high-prevalence HIV setting. © 2014 John Wiley & Sons Ltd.

  11. Chronic exercise prevents repeated restraint stress-provoked enhancement of immobility in forced swimming test in ovariectomized mice.

    Science.gov (United States)

    Han, Tae-Kyung; Lee, Jang-Kyu; Leem, Yea-Hyun

    2015-06-01

    We assessed whether chronic treadmill exercise attenuated the depressive phenotype induced by restraint stress in ovariectomized mice (OVX). Immobility of OVX in the forced swimming test was comparable to that of sham mice (CON) regardless of the postoperative time. Immobility was also no difference between restrained mice (exposure to periodic restraint for 21 days; RST) and control mice (CON) on post-exposure 2nd and 9th day, but not 15th day. In contrast, the immobility of ovariectomized mice with repeated stress (OVX + RST) was profoundly enhanced compared to ovariectomized mice-alone (OVX), and this effect was reversed by chronic exercise (19 m/min, 60 min/day, 5 days/week for 8 weeks; OVX + RST + Ex) or fluoxetine administration (20 mg/kg, OVX + RST + Flu). In parallel with behavioral data, the immunoreactivity of Ki-67 and doublecortin (DCX) in OVX was significantly decreased by repeated stress. However, the reduced numbers of Ki-67- and DCX-positive cells in OVX + RST were restored in response to chronic exercise (OVX + RST + Ex) and fluoxetine (OVX + RST + Flu). In addition, the expression pattern of cAMP response element-binding protein (CREB) and calcium-calmodulin-dependent kinase IV (CaMKIV) was similar to that of the hippocampal proliferation and neurogenesis markers (Ki-67 and DCX, respectively). These results suggest that menopausal depression may be induced by an interaction between repeated stress and low hormone levels, rather than a deficit in ovarian secretion alone, which can be improved by chronic exercise.

  12. Repeated exposure to the thin ideal and implications for the self : Two weight loss program studies

    NARCIS (Netherlands)

    Klesse, A.K.; Goukens, C.; Geyskens, K.; de Ruyter, K.

    2012-01-01

    Exposure to thin models results in self-esteem shifts that influence people's motivation to diet. This research study applies a goal perspective to explain the effect of exposure to thin models on dieters' motivation to lose weight. Two (one-week) weight loss program studies that included treatment

  13. Repeated exposures to blue light-activated eosin Y enhance inactivation of E. faecalis biofilms, in vitro.

    Science.gov (United States)

    Marinic, Karlo; Manoil, Daniel; Filieri, Anna; Wataha, John C; Schrenzel, Jacques; Lange, Norbert; Bouillaguet, Serge

    2015-09-01

    In dentistry, antibacterial photodynamic therapy (a-PDT) has shown promising results for inactivating bacterial biofilms causing carious, endodontic and periodontal diseases. In the current study, we assessed the ability of eosin Y exposed to 3 irradiation protocols at inactivating Enterococcus faecalis biofilms, in vitro. E. faecalis biofilms formed on hydroxyapatite disks were incubated with eosin Y (10-80μM), then activated with blue light using different irradiation protocols. Biofilms exposed to continuous exposure were incubated for 40min before being light-activated for 960 s. For the intermittent exposure, biofilms were exposed 4 times to the light/photosensitizer combination (960 s total) without renewing the photosensitizer. For repeated a-PDT, the same light dose was delivered in a series of 4 irradiation periods separated by dark periods; fresh photosensitizer was added between each light irradiation. After treatment, bacteria were immediately labeled with LIVE/DEAD BacLight Bacterial Viability kit and viability was assessed by flow cytometry (FCM). Results were statistically analyzed using one-way ANOVA and Tukey multiple comparison intervals (α=0.05). The viability of E. faecalis biofilms exposed to 10μM eosin Y, was significantly reduced compared to controls (light only-eosin Y only). After a second exposure to blue light-activated eosin Y, viability significantly decreased from 58% to 12% whereas 6.5% of the bacterial biofilm remained live after a third exposure (p<0.05). Only 3.5% of the bacterial population survived after the fourth exposure. The results of this study indicate that blue light-activated eosin Y can photoinactivate E. faecalis biofilms grown on hydroxyapatite disks. Also, repeated exposures to blue light-activated eosin Y were shown to significantly improve efficacy. Further studies seem warranted to optimize the antibacterial activity of blue light-activated eosin Y on major oral pathogens. Copyright © 2015 Elsevier B.V. All

  14. Repeated stress exposure causes strain-dependent shifts in the behavioral economics of cocaine in rats

    NARCIS (Netherlands)

    Groblewski, Peter A.; Zietz, Chad; Willuhn, Ingo; Phillips, Paul E. M.; Chavkin, Charles

    2015-01-01

    Cocaine-experienced Wistar and Wistar Kyoto (WKY) rats received four daily repeated forced swim stress sessions (R-FSS), each of which preceded 4-hour cocaine self-administration sessions. Twenty-four hours after the last swim stress, cocaine valuation was assessed during a single-session threshold

  15. The root of the problem: increasing root vegetable intake in preschool children by repeated exposure and flavour flavour learning.

    Science.gov (United States)

    Ahern, Sara M; Caton, Samantha J; Blundell, Pam; Hetherington, Marion M

    2014-09-01

    Children's vegetable consumption falls below current recommendations, highlighting the need to identify strategies that can successfully promote intake. The current study aimed to investigate the effectiveness of flavour-flavour learning as one such strategy for increasing vegetable intake in preschool children. Children (N = 29) aged 15 to 56 months were recruited through participating nurseries. Each received a minimum of six and maximium eight exposures to a root vegetable puree with added apple puree (flavour-flavour learning) alternating with six to eight exposures to another with nothing added (repeated exposure). A third puree acted as a control. Pre- and post-intervention intake measures of the three purees with nothing added were taken to assess change in intake. Follow-up measures took place 1 month (n = 28) and 6 months (n = 10) post-intervention. Intake increased significantly from pre- to post-intervention for all purees (~36 g), with no effect of condition. Magnitude of change was smaller in the control condition. Analysis of follow-up data showed that intake remained significantly higher than baseline 1 month (p exposure increases intake of a novel vegetable in young children. Results also suggest that mere exposure (to the food, the experimenters, the procedure) can generalise to other, similar vegetables but the addition of a familiar flavour confers no added advantage above mere exposure. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Changes of lead speciation and microbial toxicity in soil treated with repeated Pb exposure in the presence of BDE209.

    Science.gov (United States)

    Zhang, Rong; Zhang, Wei; Liu, Gao; Lin, Kuangfei; Fu, Rongbing

    2016-03-01

    Lead (Pb) and decabromodiphenyl ether (BDE209) are main pollutants at electric waste (e-waste) recycling sites (EWRSs), and their joint toxicological effects have received extensive attention. Frequently, soil pollution at EWRSs usually results from the occurrence of repeated single or multiple pollution events, with continuous impacts on soil microorganisms. Therefore, a laboratory incubation study was conducted to determine Pb bioavailability and microbial toxicity in repeated Pb-polluted soil in the presence of BDE209 for the first time. We evaluated the impacts of repetitive exposure trials on chemical fractions of Pb, and the results showed that repeated single Pb pollution event resulted in an increase of carbonates fraction of Pb, which was different from one-off single Pb exposure. Moreover, one-off Pb-treated groups exhibited higher I R (reduced partition index) values on day 30 and all treatments remained the same I R level at the end of incubation period. The parameters of microbial toxicity were well reflected by soil enzymes. During the entire incubation, the dehydrogenase and urease activities were significantly inhibited by Pb (P soil enzymes were clearly observed (P < 0.05 or 0.01). Such observations would provide useful information for ecological effects of Pb and BDE209 at EWRSs.

  17. A maximal cycle test with good validity and high repeatability in adults of all ages

    DEFF Research Database (Denmark)

    Eriksen, L; Tolstrup, J S; Larsen, Steen

    2014-01-01

    indirectly in both tests and measured directly in one test. Agreement between the direct measurement and the indirect estimate of VO2max and repeatability of the indirect estimates of VO2max were examined by Bland-Altman plots, limits of agreement (LOA) and coefficient of repeatability (CR). The indirect...... method (mean VO2max=3 132 ml · min(-1)) underestimated VO2max as compared to the direct method (mean VO2max=3 190 ml · min(-1)) in men (bias: 58 ml · min(-1) (95% LOA-450 and 565)) and overestimated VO2max in women (mean VO2max=2 328 vs. 2 258 ml · min(-1), bias: - 70 ml · min(-1) (95% LOA-468 and 328...

  18. Implementation of repeat HIV testing during pregnancy in Kenya: a qualitative study.

    Science.gov (United States)

    Rogers, Anna Joy; Weke, Elly; Kwena, Zachary; Bukusi, Elizabeth A; Oyaro, Patrick; Cohen, Craig R; Turan, Janet M

    2016-07-11

    Repeat HIV testing in late pregnancy has the potential to decrease rates of mother-to-child transmission of HIV by identifying mothers who seroconvert after having tested negative for HIV in early pregnancy. Despite being national policy in Kenya, the available data suggest that implementation rates are low. We conducted 20 in-depth semi-structured interviews with healthcare providers and managers to explore barriers and enablers to implementation of repeat HIV testing guidelines for pregnant women. Participants were from the Nyanza region of Kenya and were purposively selected to provide variation in socio-demographics and job characteristics. Interview transcripts were coded and analyzed in Dedoose software using a thematic analysis approach. Four themes were identified a priori using Ferlie and Shortell's Framework for Change and additional themes were allowed to emerge from the data. Participants identified barriers and enablers at the client, provider, facility, and health system levels. Key barriers at the client level from the perspective of providers included late initial presentation to antenatal care and low proportions of women completing the recommended four antenatal visits. Barriers to offering repeat HIV testing for providers included heavy workloads, time limitations, and failing to remember to check for retest eligibility. At the facility level, inconsistent volume of clients and lack of space required for confidential HIV retesting were cited as barriers. Finally, at the health system level, there were challenges relating to the HIV test kit supply chain and the design of nationally standardized antenatal patient registers. Enablers to improving the implementation of repeat HIV testing included client dissemination of the benefits of antenatal care through word-of-mouth, provider cooperation and task shifting, and it was suggested that use of an electronic health record system could provide automatic reminders for retest eligibility. This study

  19. Multi Directional Repeated Sprint Is a Valid and Reliable Test for Assessment of Junior Handball Players

    Directory of Open Access Journals (Sweden)

    Amin Daneshfar

    2018-04-01

    Full Text Available The aim of the present study was to examine the validity and reliability of a 10 × (6 × 5 m multi-directional repeated sprint ability test (RSM in elite young team handball (TH players. Participants were members of the Iranian national team (n = 20, age 16.4 ± 0.7 years, weight 82.5 ± 5.5 kg, height 184.8 ± 4.6 cm, body fat 15.4 ± 4.3%. The validity of RSM was tested against a 10 × (15 + 15 m repeated sprint ability test (RSA, Yo-Yo Intermittent Recovery test Level 1 (Yo-Yo IR1, squat jump (SJ and countermovement jump (CMJ. To test the reliability of RSM, the participants repeated the testing sessions of RSM and RSA 1 week later. Both RSA and RSM tests showed good to excellent reliability of the total time (TT, best time (BT, and weakest time (WT. The results of the correlation analysis showed significant inverse correlations between maximum aerobic capacity and TT in RSA (r = −0.57, p ≤ 0.05 and RSM (r = −0.76, p ≤ 0.01. There was also a significant inverse correlation between maximum aerobic capacity with fatigue index (FI in RSA test (r = −0.64, p ≤ 0.01 and in RSM test (r = −0.53, p ≤ 0.05. BT, WT, and TT of RSA was largely-to-very largely correlated with BT (r = 0.58, p ≤ 0.01, WT (r = 0.62, p ≤ 0.01, and TT (r = 0.65, p ≤ 0.01 of RSM. BT in RSM was also correlated with FI in RSM (r = 0.88, p ≤ 0.01. In conclusion, based on the findings of the current study, the recently developed RSM test is a valid and reliable test and should be utilized for assessment of repeated sprint ability in handball players.

  20. Multi Directional Repeated Sprint Is a Valid and Reliable Test for Assessment of Junior Handball Players

    Science.gov (United States)

    Daneshfar, Amin; Gahreman, Daniel E.; Koozehchian, Majid S.; Amani Shalamzari, Sadegh; Hassanzadeh Sablouei, Mozhgan; Rosemann, Thomas; Knechtle, Beat; Nikolaidis, Pantelis T.

    2018-01-01

    The aim of the present study was to examine the validity and reliability of a 10 × (6 × 5 m) multi-directional repeated sprint ability test (RSM) in elite young team handball (TH) players. Participants were members of the Iranian national team (n = 20, age 16.4 ± 0.7 years, weight 82.5 ± 5.5 kg, height 184.8 ± 4.6 cm, body fat 15.4 ± 4.3%). The validity of RSM was tested against a 10 × (15 + 15 m) repeated sprint ability test (RSA), Yo-Yo Intermittent Recovery test Level 1 (Yo-Yo IR1), squat jump (SJ) and countermovement jump (CMJ). To test the reliability of RSM, the participants repeated the testing sessions of RSM and RSA 1 week later. Both RSA and RSM tests showed good to excellent reliability of the total time (TT), best time (BT), and weakest time (WT). The results of the correlation analysis showed significant inverse correlations between maximum aerobic capacity and TT in RSA (r = −0.57, p ≤ 0.05) and RSM (r = −0.76, p ≤ 0.01). There was also a significant inverse correlation between maximum aerobic capacity with fatigue index (FI) in RSA test (r = −0.64, p ≤ 0.01) and in RSM test (r = −0.53, p ≤ 0.05). BT, WT, and TT of RSA was largely-to-very largely correlated with BT (r = 0.58, p ≤ 0.01), WT (r = 0.62, p ≤ 0.01), and TT (r = 0.65, p ≤ 0.01) of RSM. BT in RSM was also correlated with FI in RSM (r = 0.88, p ≤ 0.01). In conclusion, based on the findings of the current study, the recently developed RSM test is a valid and reliable test and should be utilized for assessment of repeated sprint ability in handball players. PMID:29670536

  1. Protective effect of curcumin on pulmonary and cardiovascular effects induced by repeated exposure to diesel exhaust particles in mice.

    Directory of Open Access Journals (Sweden)

    Abderrahim Nemmar

    Full Text Available Particulate air pollution has been associated with increased risk of cardiopulmonary diseases. However, the underlying mechanisms are not fully understood. We have previously demonstrated that single dose exposure to diesel exhaust particle (DEP causes lung inflammation and peripheral thrombotic events. Here, we exposed mice with repeated doses of DEP (15 µg/animal every 2(nd day for 6 days (a total of 4 exposures, and measured several cardiopulmonary endpoints 48 h after the end of the treatments. Moreover, the potential protective effect of curcumin (the yellow pigment isolated from turmeric on DEP-induced cardiopulmonary toxicity was assessed. DEP exposure increased macrophage and neutrophil numbers, tumor necrosis factor α (TNF α in the bronchoalveolar lavage (BAL fluid, and enhanced airway resistance to methacoline measured invasively using Flexivent. DEP also significantly increased plasma C-reactive protein (CRP and TNF α concentrations, systolic blood pressure (SBP as well as the pial arteriolar thrombosis. It also significantly enhanced the plasma D-dimer and plasminogen activator inhibitor-1 (PAI-1. Pretreatment with curcumin by oral gavage (45 mg/kg 1 h before exposure to DEP significantly prevented the influx of inflammatory cells and the increase of TNF α in BAL, and the increased airway resistance caused by DEP. Likewise, curcumin prevented the increase of SBP, CRP, TNF α, D-dimer and PAI-1. The thrombosis was partially but significantly mitigated. In conclusion, repeated exposure to DEP induced lung and systemic inflammation characterized by TNFα release, increased SBP, and accelerated coagulation. Our findings indicate that curcumin is a potent anti-inflammatory agent that prevents the release of TNFα and protects against the pulmonary and cardiovascular effects of DEP.

  2. Phasic Mesolimbic Dopamine Signaling Encodes the Facilitation of Incentive Motivation Produced by Repeated Cocaine Exposure

    OpenAIRE

    Ostlund, SB; LeBlanc, KH; Kosheleff, AR; Wassum, KM; Maidment, NT

    2014-01-01

    Drug addiction is marked by pathological drug seeking and intense drug craving, particularly in response to drug-related stimuli. Repeated psychostimulant administration is known to induce long-term alterations in mesolimbic dopamine (DA) signaling that are hypothesized to mediate this heightened sensitivity to environmental stimuli. However, there is little direct evidence that drug-induced alteration in mesolimbic DA function underlies this hypersensitivity to motivational cues. In the curr...

  3. Combined Study of Titanium Dioxide Nanoparticle Transport and Toxicity on Microbial Nitrifying Communities under Single and Repeated Exposures in Soil Columns.

    Science.gov (United States)

    Simonin, Marie; Martins, Jean M F; Uzu, Gaëlle; Vince, Erwann; Richaume, Agnès

    2016-10-04

    Soils are exposed to nanoparticles (NPs) as a result of their increasing use in many commercial products. Adverse effects of NPs on soil microorganisms have been reported in several ecotoxicological studies using microcosms. Although repeated exposures are more likely to occur in soils, most of these previous studies were performed as a single exposure to NPs. Contrary to single contamination, the study of multiple NP contaminations in soils requires the use of specialized setups. Using a soil column experiment, we compared the influence of single and repeated exposures (one, two, or three exposures that resulted in the same final concentration applied) on the transport of titanium dioxide (TiO 2 ) NPs through soil and the effect of these different exposure scenarios on the abundance and activity of soil nitrifying microbial communities after a 2 month incubation. The transport of TiO 2 NPs was very limited under both single and repeated exposures and was highest for the lowest concentration injected during the first application. Significant decreases in nitrification activity and ammonia-oxidizing archaea and bacteria populations were observed only for the repeated exposure scenario (three TiO 2 NP contaminations). These results suggest that, under repeated exposures, the transport of TiO 2 NPs to deep soil layers and groundwater is limited and that a chronic contamination is more harmful for the soil microbiological functioning than a single exposure.

  4. Solar exposure of sunglasses: aging test display

    Science.gov (United States)

    Gomes, L. M.; Masili, M.; Momesso, G. A.; Silva, F. M.; Ventura, L.

    2018-02-01

    In previous studies conducted in our lab, we have been investigating the aging effects on sunglasses. Some preliminary results have been indicating changes on the UV protection on the lenses. Therefore, besides irradiating the samples with a proper sun simulator, we have also been concerned on exposing the sunglasses to natural sun for further investigation and comparisons. Thus, this project aims expose the lenses for 24 months using an automatic solar exposition station, which consists of a series of 5 panels, housing 60 lenses arranged in the vertical position to the ground, which will be irradiated by the sun from sunrise until sunset. A box structure moves along a rail, driven by a motor and then the lenses are exposed. Humidity, rain, temperature, dust and UV index sensors, as well as a video camera are part of the system. The exposure time and UV index will be recorded and automatic opening or closing the box system may also be controlled by a PC using a webserver. The system was tested in working conditions, i.e. exposed to the weather and being automatically controlled, for five months to certifying that the samples could be exposed without being damaged. The next step of the research is to start the exposition cycles and to measure the expected transmittance variations after each cycle.

  5. Repeated exposure of the developing rat brain to magnetic resonance imaging did not affect neurogenesis, cell death or memory function

    International Nuclear Information System (INIS)

    Zhu, Changlian; Gao, Jianfeng; Li, Qian; Huang, Zhiheng; Zhang, Yu; Li, Hongfu; Kuhn, Hans-Georg; Blomgren, Klas

    2011-01-01

    Research highlights: → The effect of MRI on the developing brain is a matter of debate. → Repeated exposure to MRI did not affect neurogenesis. → Memory function was not affected by repeated MRI during development. → Neither late gestation nor young postnatal brains were affected by MRI. → Repeated MRI did not cause cell death in the neurogenic region of the hippocampus. -- Abstract: The effect of magnetic fields on the brain is a matter of debate. The objective of this study was to investigate whether repeated exposure to strong magnetic fields, such as during magnetic resonance imaging (MRI), could elicit changes in the developing rat brain. Embryonic day 15 (E15) and postnatal day 14 (P14) rats were exposed to MRI using a 7.05 T MR system. The animals were anesthetized and exposed for 35 min per day for 4 successive days. Control animals were anesthetized but no MRI was performed. Body temperature was maintained at 37 o C. BrdU was injected after each session (50 mg/kg). One month later, cell proliferation, neurogenesis and astrogenesis in the dentate gyrus were evaluated, revealing no effects of MRI, neither in the E15, nor in the P14 group. DNA damage in the dentate gyrus in the P14 group was evaluated on P18, 1 day after the last session, using TUNEL staining. There was no difference in the number of TUNEL-positive cells after MRI compared with controls, neither in mature neurons, nor in newborn progenitors (BrdU/TUNEL double-labeled cells). Novel object recognition was performed to assess memory function 1 month after MRI. There was no difference in the recognition index observed after MRI compared with the control rats, neither for the E15, nor for the P14 group. In conclusion, repeated exposure to MRI did not appear to affect neurogenesis, cell death or memory function in rats, neither in late gestation (E15-E18) nor in young postnatal (P14-P17) rats.

  6. Evaluation of Pulmonary and Systemic Toxicity of Oil Dispersant (COREXIT EC9500A(®)) Following Acute Repeated Inhalation Exposure.

    Science.gov (United States)

    Roberts, Jenny R; Anderson, Stacey E; Kan, Hong; Krajnak, Kristine; Thompson, Janet A; Kenyon, Allison; Goldsmith, William T; McKinney, Walter; Frazer, David G; Jackson, Mark; Fedan, Jeffrey S

    2014-01-01

    Oil spill cleanup workers come into contact with numerous potentially hazardous chemicals derived from the oil spills, as well as chemicals applied for mitigation of the spill, including oil dispersants. In response to the Deepwater Horizon Macondo well oil spill in the Gulf of Mexico in 2010, a record volume of the oil dispersant, COREXIT EC9500A, was delivered via aerial applications, raising concern regarding potential health effects that may result from pulmonary exposure to the dispersant. The current study examined the effects on pulmonary functions, cardiovascular functions, and systemic immune responses in rats to acute repeated inhalation exposure of COREXIT EC9500A at 25 mg/m(3), five hours per day, over nine work days, or filtered air (control). At one and seven days following the last exposure, a battery of parameters was measured to evaluate lung function, injury, and inflammation; cardiovascular function; peripheral vascular responses; and systemic immune responses. No significant alterations in airway reactivity were observed at one or seven days after exposure either in baseline values or following methacholine (MCh) inhalation challenge. Although there was a trend for an increase in lung neutrophils and phagocyte oxidant production at one-day post exposure, there were no significant differences in parameters of lung inflammation. In addition, increased blood monocytes and neutrophils, and decreased lymphocyte numbers at one-day post exposure also did not differ significantly from air controls, and no alterations in splenocyte populations, or serum or spleen immunoglobulin M (IgM) to antigen were observed. There were no significant differences in peripheral vascular responsiveness to vasoconstrictor and vasodilator agonists or in blood pressure (BP) responses to these agents; however, the baseline heart rate (HR) and HR responses to isoproterenol (ISO) were significantly elevated at one-day post exposure, with resolution by day 7. In summary, acute

  7. Evaluation of Pulmonary and Systemic Toxicity of Oil Dispersant (COREXIT EC9500A following Acute Repeated Inhalation Exposure

    Directory of Open Access Journals (Sweden)

    Jenny R. Roberts

    2014-01-01

    Full Text Available Introduction Oil spill cleanup workers come into contact with numerous potentially hazardous chemicals derived from the oil spills, as well as chemicals applied for mitigation of the spill, including oil dispersants. In response to the Deepwater Horizon Macondo well oil spill in the Gulf of Mexico in 2010, a record volume of the oil dispersant, COREXIT EC9500A, was delivered via aerial applications, raising concern regarding potential health effects that may result from pulmonary exposure to the dispersant. Methods The current study examined the effects on pulmonary functions, cardiovascular functions, and systemic immune responses in rats to acute repeated inhalation exposure of COREXIT EC9500A at 25 mg/m 3 , five hours per day, over nine work days, or filtered air (control. At one and seven days following the last exposure, a battery of parameters was measured to evaluate lung function, injury, and inflammation; cardiovascular function; peripheral vascular responses; and systemic immune responses. Results No significant alterations in airway reactivity were observed at one or seven days after exposure either in baseline values or following metha-choline (MCh inhalation challenge. Although there was a trend for an increase in lung neutrophils and phagocyte oxidant production at one-day post exposure, there were no significant differences in parameters of lung inflammation. In addition, increased blood monocytes and neutrophils, and decreased lymphocyte numbers at one-day post exposure also did not differ significantly from air controls, and no alterations in splenocyte populations, or serum or spleen immunoglobulin M (IgM to antigen were observed. There were no significant differences in peripheral vascular responsiveness to vasoconstrictor and vasodilator agonists or in blood pressure (BP responses to these agents; however, the baseline heart rate (HR and HR responses to isoproterenol (ISO were significantly elevated at one-day post exposure

  8. Distribution of dearomatised white spirit in brain, blood, and fat tissue after repeated exposure of rats

    DEFF Research Database (Denmark)

    Lof, A.; Lam, Henrik Rye; Gullstrand, E.

    1999-01-01

    Petroleum products with low content of aromatics have been increasingly used during the past years. This study investigates tissue disposition of dearomatised white spirit. In addition, brain neurotransmitter concentrations were measured. Male rats were exposed by inhalation to 0, 400 (2.29 mg....../l), or 800 p.p.m. (4.58 mg/l) of dearomatised white spirit, 6 hr/day, 5 days/week up to 3 weeks. Five rats from each group were sacrificed immediately after the exposure for 1, 2, or 3 weeks and 2, 4, 6, or 24 hr after the end of 3 weeks' exposure. After 3 weeks of exposure the concentration of total white...... spirit was 1.5 and 5.6 mg/kg in blood; 7.1 and 17.1 mg/kg in brain; 432 and 1452 mg/kg in fat tissue at the exposure levels of 400 and 800 p.p.m., respectively. The concentrations of n-nonane, n-decane, n-undecane, and total white spirit in blood and brain were not affected by the duration of exposure...

  9. Effects of Repeated Testing on Short- and Long-Term Memory Performance across Different Test Formats

    Science.gov (United States)

    Stenlund, Tova; Sundström, Anna; Jonsson, Bert

    2016-01-01

    This study examined whether practice testing with short-answer (SA) items benefits learning over time compared to practice testing with multiple-choice (MC) items, and rereading the material. More specifically, the aim was to test the hypotheses of "retrieval effort" and "transfer appropriate processing" by comparing retention…

  10. Photoprotection due to pigmentation and epidermal thickness after repeated exposure to ultraviolet light and psoralen plus ultraviolet A therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bech-Thomsen, N.; Wulf, H.C. [Rigshospitalet, The National Univ. Hospital, Dept. of Dermatology, Lab. of Photobiology, Copenhagen (Denmark)

    1995-10-01

    Tanning and thickening of the epidermis are cardinal defensive responses of human skin to ultraviolet (UV) radiation that lead to increased photoprotection. Earlier studies have shown that skin pigmentation can be used to predict minimal erythema dose and minimal phototoxic dose. In this study it was calculated how much of the increase in photoprotection after 4 weeks of repeated exposure to suberythemogenic doses of either UVA or UVB radiation sources or psoralen plus UVA (PUVA) therapy that was attributable to melanogenesis. The backs of 12 volunteers were exposed to 6 different UVA and UVB radiation sources 9 times during 4 weeks. Skin pigmentation was assessed by skin reflectance measuring. Photoprotection was determined from the minimal erythema dose. Melanogenesis accounted for 63-95% of the increase in photoprotection after 4 weeks of exposure to UVA radiation. Exposure to two UVB sources induced a significant increase in photoprotection but not in pigmentation. Melanogenesis accounted only for 6-11% of the increase in photoprotection after 4 weeks of UVB exposure. The pigmentary and photoprotective responses to PUVA therapy were followed in 14 patients. After 2 weeks of exposure, the increase in photoprotection was significantly higher than predicted form the increase in skin pigmentation. After 4 weeks, melanogenesis accounted for only 36% of the increase in photoprotection. This study shows that melanogenesis accounts for the increased photoprotection after 2 weeks of exposure to UVA radiation, but after 4 weeks other protective mechanisms occur during suberythemal UVB exposure and during PUVA therapy the importance of skin pigmentation in the overall photoprotection gradually decreases during a 4-week irradiation period. (au) 17 refs.

  11. Photoprotection due to pigmentation and epidermal thickness after repeated exposure to ultraviolet light and psoralen plus ultraviolet A therapy

    International Nuclear Information System (INIS)

    Bech-Thomsen, N.; Wulf, H.C.

    1995-01-01

    Tanning and thickening of the epidermis are cardinal defensive responses of human skin to ultraviolet (UV) radiation that lead to increased photoprotection. Earlier studies have shown that skin pigmentation can be used to predict minimal erythema dose and minimal phototoxic dose. In this study it was calculated how much of the increase in photoprotection after 4 weeks of repeated exposure to suberythemogenic doses of either UVA or UVB radiation sources or psoralen plus UVA (PUVA) therapy that was attributable to melanogenesis. The backs of 12 volunteers were exposed to 6 different UVA and UVB radiation sources 9 times during 4 weeks. Skin pigmentation was assessed by skin reflectance measuring. Photoprotection was determined from the minimal erythema dose. Melanogenesis accounted for 63-95% of the increase in photoprotection after 4 weeks of exposure to UVA radiation. Exposure to two UVB sources induced a significant increase in photoprotection but not in pigmentation. Melanogenesis accounted only for 6-11% of the increase in photoprotection after 4 weeks of UVB exposure. The pigmentary and photoprotective responses to PUVA therapy were followed in 14 patients. After 2 weeks of exposure, the increase in photoprotection was significantly higher than predicted form the increase in skin pigmentation. After 4 weeks, melanogenesis accounted for only 36% of the increase in photoprotection. This study shows that melanogenesis accounts for the increased photoprotection after 2 weeks of exposure to UVA radiation, but after 4 weeks other protective mechanisms occur during suberythemal UVB exposure and during PUVA therapy the importance of skin pigmentation in the overall photoprotection gradually decreases during a 4-week irradiation period. (au) 17 refs

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

    DEFF Research Database (Denmark)

    Löschner, Katrin; Hadrup, Niels; Qvortrup, Klaus

    2011-01-01

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

  13. A Modified Jonckheere Test Statistic for Ordered Alternatives in Repeated Measures Design

    Directory of Open Access Journals (Sweden)

    Hatice Tül Kübra AKDUR

    2016-09-01

    Full Text Available In this article, a new test based on Jonckheere test [1] for  randomized blocks which have dependent observations within block is presented. A weighted sum for each block statistic rather than the unweighted sum proposed by Jonckheereis included. For Jonckheere type statistics, the main assumption is independency of observations within block. In the case of repeated measures design, the assumption of independence is violated. The weighted Jonckheere type statistic for the situation of dependence for different variance-covariance structure and the situation based on ordered alternative hypothesis structure of each block on the design is used. Also, the proposed statistic is compared to the existing test based on Jonckheere in terms of type I error rates by performing Monte Carlo simulation. For the strong correlations, circular bootstrap version of the proposed Jonckheere test provides lower rates of type I error.

  14. Remaining life assessment of carbon steel boiler headers by repeated creep testing

    Energy Technology Data Exchange (ETDEWEB)

    Drew, M. [ANSTO, Materials and Engineering Science, New Illawarra Road, Lucas Heights, PMB 1 Menai, NSW 2234 (Australia)]. E-mail: michael.drew@ansto.gov.au; Humphries, S. [ANSTO, Materials and Engineering Science, New Illawarra Road, Lucas Heights, PMB 1 Menai, NSW 2234 (Australia); Thorogood, K. [ANSTO, Materials and Engineering Science, New Illawarra Road, Lucas Heights, PMB 1 Menai, NSW 2234 (Australia); Barnett, N. [BlueScope Steel, P.O. Box 1854, Wollongong, NSW (Australia)

    2006-05-15

    The condition of carbon steel boiler headers that have been in service for over 25 years has been assessed periodically by NDT, dimensional measurements, replication and accelerated creep testing. Historical temperature records were limited, so estimates of effective header temperatures were made from replicas. These estimates were compared with header stub thermocouple readings. At about 280,000 service hours, samples were chain-drilled from the headers for accelerated creep testing. These test results indicated that the headers had satisfactory remaining life. Nine years after the original samples were taken, additional samples were removed from one header at 337,000 service hours. The creep rupture properties measured from the repeated tests were almost identical to the initial results. A mild degree of random, nodular graphite was found in the samples and its effect on creep properties is discussed.

  15. Identification of genomic biomarkers for anthracycline-induced cardiotoxicity in human iPSC-derived cardiomyocytes: an in vitro repeated exposure toxicity approach for safety assessment.

    Science.gov (United States)

    Chaudhari, Umesh; Nemade, Harshal; Wagh, Vilas; Gaspar, John Antonydas; Ellis, James K; Srinivasan, Sureshkumar Perumal; Spitkovski, Dimitry; Nguemo, Filomain; Louisse, Jochem; Bremer, Susanne; Hescheler, Jürgen; Keun, Hector C; Hengstler, Jan G; Sachinidis, Agapios

    2016-11-01

    The currently available techniques for the safety evaluation of candidate drugs are usually cost-intensive and time-consuming and are often insufficient to predict human relevant cardiotoxicity. The purpose of this study was to develop an in vitro repeated exposure toxicity methodology allowing the identification of predictive genomics biomarkers of functional relevance for drug-induced cardiotoxicity in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). The hiPSC-CMs were incubated with 156 nM doxorubicin, which is a well-characterized cardiotoxicant, for 2 or 6 days followed by washout of the test compound and further incubation in compound-free culture medium until day 14 after the onset of exposure. An xCELLigence Real-Time Cell Analyser was used to monitor doxorubicin-induced cytotoxicity while also monitoring functional alterations of cardiomyocytes by counting of the beating frequency of cardiomyocytes. Unlike single exposure, repeated doxorubicin exposure resulted in long-term arrhythmic beating in hiPSC-CMs accompanied by significant cytotoxicity. Global gene expression changes were studied using microarrays and bioinformatics tools. Analysis of the transcriptomic data revealed early expression signatures of genes involved in formation of sarcomeric structures, regulation of ion homeostasis and induction of apoptosis. Eighty-four significantly deregulated genes related to cardiac functions, stress and apoptosis were validated using real-time PCR. The expression of the 84 genes was further studied by real-time PCR in hiPSC-CMs incubated with daunorubicin and mitoxantrone, further anthracycline family members that are also known to induce cardiotoxicity. A panel of 35 genes was deregulated by all three anthracycline family members and can therefore be expected to predict the cardiotoxicity of compounds acting by similar mechanisms as doxorubicin, daunorubicin or mitoxantrone. The identified gene panel can be applied in the safety

  16. Effects of repeated asenapine in a battery of tests for anxiety-like behaviours in mice.

    Science.gov (United States)

    Ene, Hila M; Kara, Nirit Z; Barak, Noa; Reshef Ben-Mordechai, Tal; Einat, Haim

    2016-04-01

    A number of atypical antipsychotic drugs were demonstrated to have anxiolytic effects in patients and in animal models. These effects were mostly suggested to be the consequence of the drugs' affinity to the serotonin system and its receptors. Asenapine is a relatively new atypical antipsychotic that is prescribed for schizophrenia and for bipolar mania. Asenapine has a broad pharmacological profile with significant effects on serotonergic receptors, hence it is reasonable to expect that asenapine may have some anxiolytic effects. The present study was therefore designed to examine possible effects of asenapine on anxiety-like behaviour of mice. Male ICR mice were repeatedly treated with 0.1 or 0.3 mg/kg injections of asenapine and then tested in a battery of behavioural tests related to anxiety including the open-field test, elevated plus-maze (EPM), defensive marble burying and hyponeophagia tests. In an adjunct experiment, we tested the effects of acute diazepam in the same test battery. The results show that diazepam reduced anxiety-like behaviour in the EPM, the defensive marble burying test and the hyponeophagia test but not in the open field. Asenapine has anxiolytic-like effects in the EPM and the defensive marble burying tests but had no effects in the open-field or the hyponeophagia tests. Asenapine had no effects on locomotor activity. The results suggest that asenapine may have anxiolytic-like properties and recommends that clinical trials examining such effects should be performed.

  17. The in vitro biokinetics of chlorpromazine and diazepam in aggregating rat brain cell cultures after repeated exposure

    NARCIS (Netherlands)

    Broeders, Jessica J W; Hermens, Joop L M; Blaauboer, Bas J; Zurich, Marie-Gabrielle

    2015-01-01

    Neurotoxic effects of compounds can be tested in vitro using cell systems. One example is aggregating rat brain cell cultures. For the extrapolation of in vitro data to the in vivo situation, it is important to take the biokinetics of the test compound into account. In addition, the exposure in vivo

  18. Repeated Exposure to Neurotoxic Levels of Chlorpyriphos Alters Hippocampal Expression of Neurotrophins and Neuropeptides

    Science.gov (United States)

    2016-01-13

    hormone bindi Bdnf BDNF Brain-derived neurotrophic factor Mdk MDK Midkine (neurite growth -promoting fa Rbp4 RBP4 Retinol binding protein 4, plasma...cause cholinergic crisis are associated with problems in cognitive function (i.e., learning and memory deficits ), but the biological mechanism(s...neurobehavioral deficits following subchronic exposure to CPF at a level that inhibits hippocampal cholinesterase to less than 20% of control. An equally

  19. Writing content predicts benefit from written expressive disclosure: Evidence for repeated exposure and self-affirmation.

    Science.gov (United States)

    Niles, Andrea N; Byrne Haltom, Kate E; Lieberman, Matthew D; Hur, Christopher; Stanton, Annette L

    2016-01-01

    Expressive disclosure regarding a stressful event improves psychological and physical health, yet predictors of these effects are not well established. The current study assessed exposure, narrative structure, affect word use, self-affirmation and discovery of meaning as predictors of anxiety, depressive and physical symptoms following expressive writing. Participants (N = 50) wrote on four occasions about a stressful event and completed self-report measures before writing and three months later. Essays were coded for stressor exposure (level of detail and whether participants remained on topic), narrative structure, self-affirmation and discovery of meaning. Linguistic Inquiry and Word Count software was used to quantify positive and negative affect word use. Controlling for baseline anxiety, more self-affirmation and detail about the event predicted lower anxiety symptoms, and more negative affect words (very high use) and more discovery of meaning predicted higher anxiety symptoms three months after writing. Findings highlight the importance of self-affirmation and exposure as predictors of benefit from expressive writing.

  20. Preventive effect of curcumin and its highly bioavailable preparation on hearing loss induced by single or repeated exposure to noise: A comparative and mechanistic study

    Directory of Open Access Journals (Sweden)

    Taro Yamaguchi

    2017-08-01

    Full Text Available We sought to determine the preventive effects of curcumin and its highly bioavailable preparation on noise-induced hearing loss in a novel murine model of permanent hearing loss developed by repeated exposure to noise. Upon exposure to noise (8-kHz octave band noise, 90 dB sound pressure level, 1 h, hearing ability was impaired in a temporary and reversible manner. During repeated noise exposure (1-h exposure per day, 5 days, there was a progressive increase in the auditory threshold shift at 12 and 20 kHz. The threshold shift persisted for at least 6 days after noise exposure. Oral administration of curcumin for 3 days before and each day during noise exposure significantly alleviated the hearing loss induced by repeated noise exposure. Curcumin abolished intranuclear translocation of nuclear factor-κB-p65 and generation of 4-hydroxynonenal-adducted proteins found in the cochlea after noise exposure. Theracurmin®, a highly absorbable and bioavailable preparation of curcumin, had strong preventive effects on hearing loss induced by repeated noise exposure. Together, these data suggest that curcumin exerts a preventive effect on noise-induced hearing loss and is therefore a good therapeutic candidate for preventing sensorineural hearing loss.

  1. Preventive effect of curcumin and its highly bioavailable preparation on hearing loss induced by single or repeated exposure to noise: A comparative and mechanistic study.

    Science.gov (United States)

    Yamaguchi, Taro; Yoneyama, Masanori; Onaka, Yusuke; Imaizumi, Atsushi; Ogita, Kiyokazu

    2017-08-01

    We sought to determine the preventive effects of curcumin and its highly bioavailable preparation on noise-induced hearing loss in a novel murine model of permanent hearing loss developed by repeated exposure to noise. Upon exposure to noise (8-kHz octave band noise, 90 dB sound pressure level, 1 h), hearing ability was impaired in a temporary and reversible manner. During repeated noise exposure (1-h exposure per day, 5 days), there was a progressive increase in the auditory threshold shift at 12 and 20 kHz. The threshold shift persisted for at least 6 days after noise exposure. Oral administration of curcumin for 3 days before and each day during noise exposure significantly alleviated the hearing loss induced by repeated noise exposure. Curcumin abolished intranuclear translocation of nuclear factor-κB-p65 and generation of 4-hydroxynonenal-adducted proteins found in the cochlea after noise exposure. Theracurmin ® , a highly absorbable and bioavailable preparation of curcumin, had strong preventive effects on hearing loss induced by repeated noise exposure. Together, these data suggest that curcumin exerts a preventive effect on noise-induced hearing loss and is therefore a good therapeutic candidate for preventing sensorineural hearing loss. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  2. Diffusion-weighted (DW) MRI in lung cancers. ADC test-retest repeatability

    Energy Technology Data Exchange (ETDEWEB)

    Weller, Alex; Papoutsaki, Marianthi Vasiliki; Blackledge, Matthew; DeSouza, Nandita M. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, CRUK Cancer Imaging Centre, Surrey (United Kingdom); Waterton, John C. [University of Manchester, Manchester (United Kingdom); Chiti, Arturo [Humanitas University, Milan (Italy); Stroobants, Sigrid [Universiteit Antwerpen, Antwerpen (Belgium); Kuijer, Joost [Vrije Universiteit Medisch Centrum, Amsterdam (Netherlands); Morgan, Veronica [Royal Marsden NHS Foundation Trust, Department of Medicine, London (United Kingdom)

    2017-11-15

    To determine the test-retest repeatability of Apparent Diffusion Coefficient (ADC) measurements across institutions and MRI vendors, plus investigate the effect of post-processing methodology on measurement precision. Thirty malignant lung lesions >2 cm in size (23 patients) were scanned on two occasions, using echo-planar-Diffusion-Weighted (DW)-MRI to derive whole-tumour ADC (b = 100, 500 and 800 s/mm{sup -2}). Scanning was performed at 4 institutions (3 MRI vendors). Whole-tumour volumes-of-interest were copied from first visit onto second visit images and from one post-processing platform to an open-source platform, to assess ADC repeatability and cross-platform reproducibility. Whole-tumour ADC values ranged from 0.66-1.94x10{sup -3} mm{sup 2}s{sup -1} (mean = 1.14). Within-patient coefficient-of-variation (wCV) was 7.1% (95% CI 5.7-9.6%), limits-of-agreement (LoA) -18.0 to 21.9%. Lesions >3 cm had improved repeatability: wCV 3.9% (95% CI 2.9-5.9%); and LoA -10.2 to 11.4%. Variability for lesions <3 cm was 2.46 times higher. ADC reproducibility across different post-processing platforms was excellent: Pearson's R{sup 2} = 0.99; CoV 2.8% (95% CI 2.3-3.4%); and LoA -7.4 to 8.0%. A free-breathing DW-MRI protocol for imaging malignant lung tumours achieved satisfactory within-patient repeatability and was robust to changes in post-processing software, justifying its use in multi-centre trials. For response evaluation in individual patients, a change in ADC >21.9% will reflect treatment-related change. (orig.)

  3. Cost-effectiveness of a repeat HIV test in pregnancy in India.

    Science.gov (United States)

    Joshi, Smita; Kulkarni, Vinay; Gangakhedkar, Raman; Mahajan, Uma; Sharma, Sushma; Shirole, Devendra; Chandhiok, Nomita

    2015-06-11

    To evaluate cost-effectiveness of second HIV test in pregnancy. Current strategy of single HIV test during pregnancy in India can miss new HIV infections acquired after the first test or those HIV infections that were missed in the first test due to a false-negative HIV test. Between August 2011 and April 2013, 9097 pregnant HIV uninfected women were offered a second HIV test near term (34 weeks or beyond) or within 4 weeks of postpartum period. A decision analysis model was used to evaluate cost-effectiveness of a second HIV test in pregnant women near term. Our key outcome measures include programme cost with addition of second HIV test in pregnant women and quality-adjusted life years (QALYs) gained. We detected 4 new HIV infections in the second test. Thus HIV incidence among pregnant women was 0.12 (95% 0.032 to 0.297) per 100 person women years (PWY). Current strategy of a single HIV test is 8.2 times costlier for less QALYs gained as compared to proposed repeat HIV testing of pregnant women who test negative during the first test. Our results warrant consideration at the national level for including a second HIV test of all pregnant women in the national programme. However prior to allocation of resources for a second HIV test in pregnancy, appropriate strategies will have to be planned for improving compliance for prevention of mother-to-child transmission of HIV and reducing loss-to-follow-up of those women detected with HIV. CTRI/2013/12/004183. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  4. Origin-Dependent Inverted-Repeat Amplification: Tests of a Model for Inverted DNA Amplification.

    Directory of Open Access Journals (Sweden)

    Bonita J Brewer

    2015-12-01

    Full Text Available DNA replication errors are a major driver of evolution--from single nucleotide polymorphisms to large-scale copy number variations (CNVs. Here we test a specific replication-based model to explain the generation of interstitial, inverted triplications. While no genetic information is lost, the novel inversion junctions and increased copy number of the included sequences create the potential for adaptive phenotypes. The model--Origin-Dependent Inverted-Repeat Amplification (ODIRA-proposes that a replication error at pre-existing short, interrupted, inverted repeats in genomic sequences generates an extrachromosomal, inverted dimeric, autonomously replicating intermediate; subsequent genomic integration of the dimer yields this class of CNV without loss of distal chromosomal sequences. We used a combination of in vitro and in vivo approaches to test the feasibility of the proposed replication error and its downstream consequences on chromosome structure in the yeast Saccharomyces cerevisiae. We show that the proposed replication error-the ligation of leading and lagging nascent strands to create "closed" forks-can occur in vitro at short, interrupted inverted repeats. The removal of molecules with two closed forks results in a hairpin-capped linear duplex that we show replicates in vivo to create an inverted, dimeric plasmid that subsequently integrates into the genome by homologous recombination, creating an inverted triplication. While other models have been proposed to explain inverted triplications and their derivatives, our model can also explain the generation of human, de novo, inverted amplicons that have a 2:1 mixture of sequences from both homologues of a single parent--a feature readily explained by a plasmid intermediate that arises from one homologue and integrates into the other homologue prior to meiosis. Our tests of key features of ODIRA lend support to this mechanism and suggest further avenues of enquiry to unravel the origins

  5. Origin-Dependent Inverted-Repeat Amplification: Tests of a Model for Inverted DNA Amplification.

    Science.gov (United States)

    Brewer, Bonita J; Payen, Celia; Di Rienzi, Sara C; Higgins, Megan M; Ong, Giang; Dunham, Maitreya J; Raghuraman, M K

    2015-12-01

    DNA replication errors are a major driver of evolution--from single nucleotide polymorphisms to large-scale copy number variations (CNVs). Here we test a specific replication-based model to explain the generation of interstitial, inverted triplications. While no genetic information is lost, the novel inversion junctions and increased copy number of the included sequences create the potential for adaptive phenotypes. The model--Origin-Dependent Inverted-Repeat Amplification (ODIRA)-proposes that a replication error at pre-existing short, interrupted, inverted repeats in genomic sequences generates an extrachromosomal, inverted dimeric, autonomously replicating intermediate; subsequent genomic integration of the dimer yields this class of CNV without loss of distal chromosomal sequences. We used a combination of in vitro and in vivo approaches to test the feasibility of the proposed replication error and its downstream consequences on chromosome structure in the yeast Saccharomyces cerevisiae. We show that the proposed replication error-the ligation of leading and lagging nascent strands to create "closed" forks-can occur in vitro at short, interrupted inverted repeats. The removal of molecules with two closed forks results in a hairpin-capped linear duplex that we show replicates in vivo to create an inverted, dimeric plasmid that subsequently integrates into the genome by homologous recombination, creating an inverted triplication. While other models have been proposed to explain inverted triplications and their derivatives, our model can also explain the generation of human, de novo, inverted amplicons that have a 2:1 mixture of sequences from both homologues of a single parent--a feature readily explained by a plasmid intermediate that arises from one homologue and integrates into the other homologue prior to meiosis. Our tests of key features of ODIRA lend support to this mechanism and suggest further avenues of enquiry to unravel the origins of interstitial

  6. Parenting, attention and externalizing problems: testing mediation longitudinally, repeatedly and reciprocally.

    Science.gov (United States)

    Belsky, Jay; Pasco Fearon, R M; Bell, Brian

    2007-12-01

    Building on prior work, this paper tests, longitudinally and repeatedly, the proposition that attentional control processes mediate the effect of earlier parenting on later externalizing problems. Repeated independent measurements of all three constructs--observed parenting, computer-tested attentional control and adult-reported externalizing problems--were subjected to structural equation modeling using data from the large-scale American study of child care and youth development. Structural equation modeling indicated (a) that greater maternal sensitivity at two different ages (54 months, approximately 6 years) predicted better attentional control on the Continuous Performance Test (CPT) of attention regulation two later ages ( approximately 6/9 years); (2) that better attentional control at three different ages (54 months, approximately 6/9 years) predicted less teacher-reported externalizing problems at three later ages ( approximately 6/8/10 years); and (3) that attentional control partially mediated the effect of parenting on externalizing problems at two different lags (i.e., 54 months--> approximately 6 years--> approximately 8 years; approximately 6 years--> approximately 9 years--> approximately 10 years), though somewhat more strongly for the first. Additionally, (4) some evidence of reciprocal effects of attentional processes on parenting emerged (54 months--> approximately 6 years; approximately 6 years--> approximately 8 years), but not of problem behavior on attention. Because attention control partially mediates the effects of parenting on externalizing problems, intervention efforts could target both parenting and attentional processes.

  7. Baseline repeated measures from controlled human exposure studies: associations between ambient air pollution exposure and the systemic inflammatory biomarkers IL-6 and fibrinogen.

    Science.gov (United States)

    Thompson, Aaron M S; Zanobetti, Antonella; Silverman, Frances; Schwartz, Joel; Coull, Brent; Urch, Bruce; Speck, Mary; Brook, Jeffrey R; Manno, Michael; Gold, Diane R

    2010-01-01

    Systemic inflammation may be one of the mechanisms mediating the association between ambient air pollution and cardiovascular morbidity and mortality. Interleukin-6 (IL-6) and fibrinogen are biomarkers of systemic inflammation that are independent risk factors for cardio-vascular disease. We investigated the association between ambient air pollution and systemic inflammation using baseline measurements of IL-6 and fibrinogen from controlled human exposure studies. In this retrospective analysis we used repeated-measures data in 45 nonsmoking subjects. Hourly and daily moving averages were calculated for ozone, nitrogen dioxide, sulfur dioxide, and particulate matter pollutants on systemic IL-6 and fibrinogen. Effect modification by season was considered. We observed a positive association between IL-6 and O3 [0.31 SD per O3 interquartile range (IQR); 95% confidence interval (CI), 0.080.54] and between IL-6 and SO2 (0.25 SD per SO2 IQR; 95% CI, 0.060.43). We observed the strongest effects using 4-day moving averages. Responses to pollutants varied by season and tended to be higher in the summer, particularly for O3 and PM2.5. Fibrinogen was not associated with pollution. This study demonstrates a significant association between ambient pollutant levels and baseline levels of systemic IL-6. These findings have potential implications for controlled human exposure studies. Future research should consider whether ambient pollution exposure before chamber exposure modifies IL-6 response.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-02-15

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

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  10. Feasibility and repeatability of cold and mechanical quantitative sensory testing in normal dogs

    Science.gov (United States)

    Briley, Jessica D.; Williams, Morika D.; Freire, Mila; Griffith, Emily H.; Lascelles, B. Duncan X.

    2015-01-01

    Feasibility and inter-session repeatability of cold and mechanical quantitative sensory testing (QST) were assessed in 24 normal dogs. Cold thermal latencies were evaluated using a thermal probe (0 °C) applied to three pelvic limb sites. Mechanical thresholds were measured using an electronic von Frey anesthesiometer (EVF) and a blunt-probed pressure algometer (PA) applied to the dorsal aspect of the metatarsus. All QST trials were performed with dogs in lateral recumbency. Collection of cold QST data was easy (feasible) in 19/24 (79%) dogs. However, only 18.4%, 18.9% and 13.2% of cold QST trials elicited a response at the medial tibia, third digital pad and plantar metatarsal regions, respectively. Collection of mechanical QST data was easy (feasible) in 20/24 (83%) dogs for both EVF and PA. At consecutive sampling times, approximately 2 weeks apart, the average EVF sensory thresholds were 414 ± 186 g and 379 ± 166 g, respectively, and the average PA sensory thresholds were 1089 ± 414 g and 1028 ± 331 g, respectively. There was no significant difference in inter-session or inter-limb threshold values for either mechanical QST device. The cold QST protocol in this study was achievable, but did not provide consistently quantifiable results. Both mechanical QST devices tested provided repeatable, reliable sensory threshold measurements in normal, client-owned dogs. These findings contribute to the validation of the EVF and PA as tools to obtain repeated QST data over time in dogs to assess somatosensory processing changes. PMID:24268475

  11. The Effects of Exposure to Repeated Minor Pain During the Neonatal Period on Formalin Pain Behavior and Thermal Withdrawal Latencies

    Directory of Open Access Journals (Sweden)

    C Celeste Johnston

    2003-01-01

    Full Text Available Preterm infants undergoing untreated, repeated painful procedures as part of their early experience are more likely to behave differently to pain as they mature than infants who were born at term and did not experience excessive exogenous pain. The neonatal rat model was used to investigate the short- and long-term effects of repeated pain in infancy on later development of pain responses. Newborn rat pups were randomly assigned by litter to be left unhandled (UH, handled by being removed from the dam for 15 min four times daily (H, and being handled and receiving pain from a paw prick with a 26G needle four times daily (Pon postnatal days (PD 2 through 8 (PD2-PD8. Maternal behaviour and grooming of pups on their return to the nest were recorded at PD6 for H and P pups. At PD15, PD36 and PD65, animals were first tested for latency to thermal stimulation threshold using the Hargreaves test and then for inflammatory pain using the formalin test. Pups in the HP group received significantly more grooming from their mothers (359 s than pups in the H group (295 s, P<0.0001. When accounting for differences in maternal grooming, a decreased thermal threshold in the P group compared with the H group (6.04 s versus 5.3 s, P<0.05 was found, although the correlations were not significant between maternal grooming and thermal thresholds. No group differences were seen with the formalin test. Interestingly, age was a significant factor in both tests, with younger animals showing fewer pain behaviours regardless of group or maternal grooming of the pup. Sex was significant at one age only in latency to thermal stimulation testing. The results suggest that changes in maternal care may be an important factor mediating the long-term effects of repeated neonatal experiences of pain.

  12. Protective effect of SP600125 against liver cell injury in rats under repeated and sustained high +Gz exposure

    Directory of Open Access Journals (Sweden)

    Wen-bing LI

    2015-01-01

    Full Text Available Objective To explore the effect of JNK inhibitor SP600125 on expression of JNK/c-jun in liver cells of rats under repeated and sustained high +Gz exposure and its mechanism of the effect. Methods Eighteen inbred adult male Wistar rats were randomly divided into control group, +10Gz group and SP600125 group (n=6. The rats in +10Gz group and SP600125 group were fixed to the rotating arm of a centrifuge with head towards the axis. The increase rate of acceleration was 1G/s with a peak-time of 3 minutes, and the +Gz exposure was repeated 5 times with an interval of 30 minutes. SP600125 was given to rats of SP600125 group 30 minutes before the first centrifugation by intraperitoneal injection. All of the animals were sacrificed 30 minutes after centrifugation. Blood samples were collected from inferior vena cava to determine the plasma level of aspartate aminotransferase (AST and alanine aminotransferase (ALT. The expression of c-jun mRNA was determined by quantitative real-time RT-PCR (qRTPCR. The expressions of p-JNK, JNK, p-c-jun and c-jun protein were determined by Western blotting. The morphological change in the liver tissue was observed after HE staining. Results The plasma level of ALT and AST, expression level of c-jun mRNA and p-JNK, p-c-jun, c-jun protein in the liver tissue of SP600125 group were significantly higher than those of control group (P0.05. HE staining revealed disorganized hepatic cords, irregular liver cells, vacuolar changes, and marked edema of hepatocytes, and collapsed hepatic sinusoids in +10Gz group, but these changes were alleviated obviously in SP600125 group. Conclusion SP600125 could alleviate the liver cell injury in rats under repeated and sustained high +Gz exposure. DOI: 10.11855/j.issn.2577-7402.2014.11.02

  13. Previous Repeated Exposure to Food Limitation Enables Rats to Spare Lipid Stores during Prolonged Starvation.

    Science.gov (United States)

    McCue, Marshall D; Albach, Audrey; Salazar, Giovanni

    The risk of food limitation and, ultimately, starvation dates back to the dawn of heterotrophy in animals, yet starvation remains a major factor in the regulation of modern animal populations. Researchers studying starvation more than a century ago suggested that animals subjected to sublethal periods of food limitation are somehow more tolerant of subsequent starvation events. This possibility has received little attention over the past decades, yet it is highly relevant to modern science for two reasons. First, animals in natural populations are likely to be exposed to bouts of food limitation once or more before they face prolonged starvation, during which the risk of mortality becomes imminent. Second, our current approach to studying starvation physiology in the laboratory focuses on nourished animals with no previous exposure to nutritional stress. We examined the relationship between previous exposure to food limitation and potentially adaptive physiological responses to starvation in adult rats and found several significant differences. On two occasions, rats were fasted until they lost 20% of their body mass maintained lower body temperatures, and had presumably lower energy requirements when subjected to prolonged starvation than their naive cohort that never experienced food limitation. These rats that were trained in starvation also had lower plasma glucose set -points and reduced their reliance on endogenous lipid oxidation. These findings underscore (1) the need for biologists to revisit the classic hypothesis that animals can become habituated to starvation, using a modern set of research tools; and (2) the need to design controlled experiments of starvation physiology that more closely resemble the dynamic nature of food availability.

  14. Community perceptions of repeat HIV-testing: experiences of the ANRS 12249 Treatment as Prevention trial in rural South Africa.

    Science.gov (United States)

    Orne-Gliemann, Joanna; Zuma, Thembelihle; Chikovore, Jeremiah; Gillespie, Natasha; Grant, Merridy; Iwuji, Collins; Larmarange, Joseph; McGrath, Nuala; Lert, France; Imrie, John

    2016-01-01

    In the context of the ANRS 12249 Treatment as Prevention (TasP) trial, we investigated perceptions of regular and repeat HIV-testing in rural KwaZulu-Natal (South Africa), an area of very high HIV prevalence and incidence. We conducted two qualitative studies, before (2010) and during the early implementation stages of the trial (2013-2014), to appreciate the evolution in community perceptions of repeat HIV-testing over this period of rapid changes in HIV-testing and treatment approaches. Repeated focus group discussions were organized with young adults, older adults and mixed groups. Repeat and regular HIV-testing was overall well perceived before, and well received during, trial implementation. Yet community members were not able to articulate reasons why people might want to test regularly or repeatedly, apart from individual sexual risk-taking. Repeat home-based HIV-testing was considered as feasible and convenient, and described as more acceptable than clinic-based HIV-testing, mostly because of privacy and confidentiality. However, socially regulated discourses around appropriate sexual behaviour and perceptions of stigma and prejudice regarding HIV and sexual risk-taking were consistently reported. This study suggests several avenues to improve HIV-testing acceptability, including implementing diverse and personalised approaches to HIV-testing and care, and providing opportunities for antiretroviral therapy initiation and care at home.

  15. Repeat testing of low-level HIV-1 RNA: assay performance and implementation in clinical trials.

    Science.gov (United States)

    White, Kirsten; Garner, Will; Wei, Lilian; Eron, Joseph J; Zhong, Lijie; Miller, Michael D; Martin, Hal; Plummer, Andrew; Tran-Muchowski, Cecilia; Lindstrom, Kim; Porter, James; Piontkowsky, David; Light, Angela; Reiske, Heinz; Quirk, Erin

    2018-05-15

    Assess the performance of HIV-1 RNA repeat testing of stored samples in cases of low-level viremia during clinical trials. Prospective and retrospective analysis of randomized clinical trial samples and reference standards. To evaluate assay variability of the Cobas AmpliPrep/Cobas TaqMan HIV-1 Test, v2.0, three separate sources of samples were utilized: the World Health Organization (WHO) HIV reference standard (assayed using 50 independent measurements at six viral loads <200 copies/ml), retrospective analysis of four to six aliquots of plasma samples from four clinical trial participants, and prospective repeat testing of 120 samples from participants in randomized trials with low-level viremia. The TaqMan assay on the WHO HIV-1 RNA standards at viral loads <200 copies/ml performed within the expected variability according to assay specifications. However, standards with low viral loads of 36 and 18 copies/ml reported values of ≥ 50 copies/ml in 66 and 18% of tests, respectively. In participants treated with antiretrovirals who had unexpected viremia of 50-200 copies/ml after achieving <50 copies/ml, retesting of multiple aliquots of stored plasma found <50 copies/ml in nearly all cases upon retesting (14/15; 93%). Repeat testing was prospectively implemented in four clinical trials for all samples with virologic rebound of 50-200 copies/ml (n = 120 samples from 92 participants) from which 42% (50/120) had a retest result of less than 50 copies/ml and 58% (70/120) retested ≥ 50 copies/ml. The TaqMan HIV-1 RNA assay shows variability around 50 copies/ml that affects clinical trial results and may impact clinical practice. In participants with a history of viral load suppression, unexpected low-level viremia may be because of assay variability rather than low drug adherence or true virologic failure. Retesting a stored aliquot of the same sample may differentiate between assay variability and virologic failure as the source of viremia

  16. Twenty-three generations of mice bidirectionally selected for open-field thigmotaxis: selection response and repeated exposure to the open field.

    Science.gov (United States)

    Leppänen, Pia K; Ravaja, N; Ewalds-Kvist, S B M

    2006-03-01

    We examined: (a) the response to bidirectional selection for open-field (OF) thigmotaxis in mice for 23 generations and (b) the effects of repeated exposure (during 5 days) on different OF behaviors in the selectively bred high OF thigmotaxis (HOFT) and low OF thigmotaxis (LOFT) mice. A total of 2049 mice were used in the study. Prior to the testing in the selection experiment, the mice were exposed to the OF apparatus for approximately 2 min on each of 4 consecutive days. Thus, the selection was based on the scores registered on the 5th day after the four habituation periods. The HOFT mice were more thigmotactic than the LOFT mice in almost each generation. The HOFT mice also tended to rear less than the LOFT mice, which was explained by the inverse relationship between emotionality and exploratory tendencies. The lines did not generally differ in ambulation. Sex differences were found in thigmotaxis, ambulation, and rearing. In the repeated exposure experiment, the development of nine different OF behaviors across the 5 days of testing was addressed. Both lines ambulated, explored, and reared most on the 1st, 4th, and 5th days. Grooming and radial latency decreased and thigmotaxis increased linearly across the testing days. Line differences were found in ambulation, exploration, grooming, and rearing, while sex differences were manifested in ambulation and exploration. The line difference in thigmotaxis was evident only on the 5th day. Temporal changes were partially at variance with the general assumptions. OF thigmotaxis was found to be a powerful characteristic for producing two diverging lines of mice.

  17. Microcomputer-based tests for repeated-measures: Metric properties and predictive validities

    Science.gov (United States)

    Kennedy, Robert S.; Baltzley, Dennis R.; Dunlap, William P.; Wilkes, Robert L.; Kuntz, Lois-Ann

    1989-01-01

    A menu of psychomotor and mental acuity tests were refined. Field applications of such a battery are, for example, a study of the effects of toxic agents or exotic environments on performance readiness, or the determination of fitness for duty. The key requirement of these tasks is that they be suitable for repeated-measures applications, and so questions of stability and reliability are a continuing, central focus of this work. After the initial (practice) session, seven replications of 14 microcomputer-based performance tests (32 measures) were completed by 37 subjects. Each test in the battery had previously been shown to stabilize in less than five 90-second administrations and to possess retest reliabilities greater than r = 0.707 for three minutes of testing. However, all the tests had never been administered together as a battery and they had never been self-administered. In order to provide predictive validity for intelligence measurement, the Wechsler Adult Intelligence Scale-Revised and the Wonderlic Personnel Test were obtained on the same subjects.

  18. Masonry fireplace emissions test method: Repeatability and sensitivity to fueling protocol.

    Science.gov (United States)

    Stern, C H; Jaasma, D R; Champion, M R

    1993-03-01

    A test method for masonry fireplaces has been evaluated during testing on six masonry fireplace configurations. The method determines carbon monoxide and particulate matter emission rates (g/h) and factors (g/kg) and does not require weighing of the appliance to determine the timing of fuel loading.The intralaboratory repeatability of the test method has been determined from multiple tests on the six fireplaces. For the tested fireplaces, the ratio of the highest to lowest measured PM rate averaged 1.17 and in no case was greater than 1.32. The data suggest that some of the variation is due to differences in fuel properties.The influence of fueling protocol on emissions has also been studied. A modified fueling protocol, tested in large and small fireplaces, reduced CO and PM emission factors by roughly 40% and reduced CO and PM rates from 0 to 30%. For both of these fireplaces, emission rates were less sensitive to fueling protocol than emission factors.

  19. Detection of local inflammation induced by repeated exposure to contact allergens by use of IVIS SpectrumCT analyses

    DEFF Research Database (Denmark)

    Nielsen, Morten M.; Schmidt, Jonas D.; Christensen, Jan P.

    2017-01-01

    Background: Contact allergy is characterized by local skin inflammation that, in some cases, can result in systemic immune activation. Objectives: To investigate whether IVIS SpectrumCT analyses can be used to detect the immune response induced by contact allergens. Methods: Mice were repeatedly...... exposed to vehicle or allergens on the ears. The local and systemic responses were analysed at different times with the ProSense 750 FAST probe in IVIS SpectrumCT measurements. In addition, changes in ear thickness, cytokine profile in the skin and immunological phenotype in the draining lymph nodes...... and spleen were determined. Results: Local inflammation was detected by ProSense 750 FAST and correlated with changes in ear thickness, cytokine profile and immunological phenotype following exposure to the strong contact allergen 2,4-dinitrofluorobenzene. Analysis of the systemic response with ProSense 750...

  20. Gender-specific association of functional prodynorphin 68 bp repeats with cannabis exposure in an African American cohort

    Directory of Open Access Journals (Sweden)

    Yuferov V

    2018-04-01

    Full Text Available Vadim Yuferov,* Eduardo R Butelman,* Mary Jeanne Kreek Laboratory of the Biology of Addictive Diseases, The Rockefeller University, New York, NY, USA *These authors contributed equally to this work Background: Cannabis use disorders (CUDs cause substantial neuropsychiatric morbidity and comorbidity. There is evidence for gender-based differences in CUDs, for instance, a greater prevalence in males than in females. The main active component of cannabis is delta 9-tetrahydrocannabinol (delta 9-THC, a partial agonist of the cannabinoid type 1 receptor. Preclinical studies show that genetic or pharmacological manipulation of the kappa opioid receptor/dynorphin system modulates the effects of delta 9-THC. Methods: In this case-control study of adult African Americans (n=476; 206 females, 270 males, we examined the association of the functional prodynorphin 68 bp (PDYN 68 bp promoter repeats with categorical diagnoses of cannabis dependence (Diagnostic and Statistical Manual of Mental Disorders-IV criteria, as well as with a rapid dimensional measure of maximum lifetime cannabis exposure (the Kreek–McHugh–Schluger–Kellogg cannabis scale. Results: The PDYN 68 bp genotype (examined as short–short [SS], short–long [SL], or long–long [LL], based on the number of repeats was not significantly associated with categorical cannabis-dependence diagnoses, either in males or in females. However, in males, the PDYN 68 bp SS+SL genotype was associated with both greater odds of any use of cannabis (p<0.05 and earlier age of first cannabis use, compared to the LL genotype (ie, 15 versus 16.5 years of age; p<0.045. Males in the SS+SL group also had greater odds of high lifetime exposure to cannabis, compared to the LL group (p<0.045. Of interest, none of the aforementioned genetic associations were significant in females. Conclusion: This study provides the first data on how the PDYN 68 bp genotype is associated with gender-specific patterns of

  1. Tualang Honey Protects the Rat Midbrain and Lung against Repeated Paraquat Exposure

    Directory of Open Access Journals (Sweden)

    Suk Peng Tang

    2017-01-01

    Full Text Available Paraquat (PQ is a dopaminergic neurotoxin and a well-known pneumotoxicant that exerts its toxic effect via oxidative stress-mediated cellular injuries. This study investigated the protective effects of Tualang honey against PQ-induced toxicity in the midbrain and lungs of rats. The rats were orally treated with distilled water (2 mL/kg/day, Tualang honey (1.0 g/kg/day, or ubiquinol (0.2 g/kg/day throughout the experimental period. Two weeks after the respective treatments, the rats were injected intraperitoneally with saline (1 mL/kg/week or PQ (10 mg/kg/week once per week for four consecutive weeks. After four weekly exposures to PQ, the glutathione peroxidase activity and the number of tyrosine-hydroxylase immunopositive neurons in the midbrain were significantly decreased in animals from group PQ (p<0.05. The lungs of animals from group PQ showed significantly decreased activity of superoxide dismutase and glutathione-S-transferase. Treatment with Tualang honey ameliorated the toxic effects observed in the midbrain and lungs. The beneficial effects of Tualang honey were comparable to those of ubiquinol, which was used as a positive control. These findings suggest that treatment with Tualang honey may protect against PQ-induced toxicity in the rat midbrain and lung.

  2. Tualang Honey Protects the Rat Midbrain and Lung against Repeated Paraquat Exposure.

    Science.gov (United States)

    Tang, Suk Peng; Kuttulebbai Nainamohamed Salam, Sirajudeen; Jaafar, Hasnan; Gan, Siew Hua; Muzaimi, Mustapha; Sulaiman, Siti Amrah

    2017-01-01

    Paraquat (PQ) is a dopaminergic neurotoxin and a well-known pneumotoxicant that exerts its toxic effect via oxidative stress-mediated cellular injuries. This study investigated the protective effects of Tualang honey against PQ-induced toxicity in the midbrain and lungs of rats. The rats were orally treated with distilled water (2 mL/kg/day), Tualang honey (1.0 g/kg/day), or ubiquinol (0.2 g/kg/day) throughout the experimental period. Two weeks after the respective treatments, the rats were injected intraperitoneally with saline (1 mL/kg/week) or PQ (10 mg/kg/week) once per week for four consecutive weeks. After four weekly exposures to PQ, the glutathione peroxidase activity and the number of tyrosine-hydroxylase immunopositive neurons in the midbrain were significantly decreased in animals from group PQ ( p honey ameliorated the toxic effects observed in the midbrain and lungs. The beneficial effects of Tualang honey were comparable to those of ubiquinol, which was used as a positive control. These findings suggest that treatment with Tualang honey may protect against PQ-induced toxicity in the rat midbrain and lung.

  3. Tualang Honey Protects the Rat Midbrain and Lung against Repeated Paraquat Exposure

    Science.gov (United States)

    Sulaiman, Siti Amrah

    2017-01-01

    Paraquat (PQ) is a dopaminergic neurotoxin and a well-known pneumotoxicant that exerts its toxic effect via oxidative stress-mediated cellular injuries. This study investigated the protective effects of Tualang honey against PQ-induced toxicity in the midbrain and lungs of rats. The rats were orally treated with distilled water (2 mL/kg/day), Tualang honey (1.0 g/kg/day), or ubiquinol (0.2 g/kg/day) throughout the experimental period. Two weeks after the respective treatments, the rats were injected intraperitoneally with saline (1 mL/kg/week) or PQ (10 mg/kg/week) once per week for four consecutive weeks. After four weekly exposures to PQ, the glutathione peroxidase activity and the number of tyrosine-hydroxylase immunopositive neurons in the midbrain were significantly decreased in animals from group PQ (p honey ameliorated the toxic effects observed in the midbrain and lungs. The beneficial effects of Tualang honey were comparable to those of ubiquinol, which was used as a positive control. These findings suggest that treatment with Tualang honey may protect against PQ-induced toxicity in the rat midbrain and lung. PMID:28127418

  4. Gender-specific association of functional prodynorphin 68 bp repeats with cannabis exposure in an African American cohort.

    Science.gov (United States)

    Yuferov, Vadim; Butelman, Eduardo R; Kreek, Mary Jeanne

    2018-01-01

    Cannabis use disorders (CUDs) cause substantial neuropsychiatric morbidity and comorbidity. There is evidence for gender-based differences in CUDs, for instance, a greater prevalence in males than in females. The main active component of cannabis is delta 9-tetrahydrocannabinol (delta 9-THC), a partial agonist of the cannabinoid type 1 receptor. Preclinical studies show that genetic or pharmacological manipulation of the kappa opioid receptor/dynorphin system modulates the effects of delta 9-THC. In this case-control study of adult African Americans (n=476; 206 females, 270 males), we examined the association of the functional prodynorphin 68 bp ( PDYN 68 bp) promoter repeats with categorical diagnoses of cannabis dependence ( Diagnostic and Statistical Manual of Mental Disorders-IV criteria), as well as with a rapid dimensional measure of maximum lifetime cannabis exposure (the Kreek-McHugh-Schluger-Kellogg cannabis scale). The PDYN 68 bp genotype (examined as short-short [SS], short-long [SL], or long-long [LL], based on the number of repeats) was not significantly associated with categorical cannabis-dependence diagnoses, either in males or in females. However, in males, the PDYN 68 bp SS+SL genotype was associated with both greater odds of any use of cannabis ( p cannabis use, compared to the LL genotype (ie, 15 versus 16.5 years of age; p cannabis, compared to the LL group ( p cannabis. Overall, this study shows that PDYN 68 bp polymorphisms affect behaviors involved in early stages of nonmedical cannabis use and potentially lead to increasing self-exposure. These data may eventually lead to improvements in personalized medicine for the prevention and treatment of highly prevalent CUDs and neuropsychiatric comorbidities.

  5. The human repeated insult patch test in the 21st century: a commentary.

    Science.gov (United States)

    Basketter, David A

    2009-01-01

    The human repeated insult patch test (HRIPT) is over half a century old, but is still used in several countries as a confirmatory test in the safety evaluation of skin sensitizers. This is despite the criticism it receives from an ethical perspective and regarding the scientific validity of such testing. In this commentary, the HRIPT is reviewed, with emphasis on ethical aspects and where the test can, and cannot, contribute in a scientifically meaningful manner to safety evaluation. It is concluded that where there is a specific rationale for testing, for example, to substantiate a no-effect level for a sensitizing chemical or to ensure that matrix effects are not making an unexpected contribution to sensitizing potency, then rigorous independent review may confirm that an HRIPT is ethical and scientifically justifiable. The possibility that sensitization may be induced in volunteers dictates that HRIPTs should be conducted rarely and in cases where the benefits overwhelmingly outweigh the risk. However, for the very large majority of HRIPTs conducted concerning the risk of skin sensitization, there is neither scientific justification nor any other merit.

  6. Neuronal changes and oxidative stress in adolescent rats after repeated exposure to mephedrone

    International Nuclear Information System (INIS)

    López-Arnau, Raúl; Martínez-Clemente, José; Rodrigo, Teresa; Pubill, David; Camarasa, Jorge; Escubedo, Elena

    2015-01-01

    Mephedrone is a new designer drug of abuse. We have investigated the neurochemical/enzymatic changes after mephedrone administration to adolescent rats (3 × 25 mg/kg, s.c. in a day, with a 2 h interval between doses, for two days) at high ambient temperature (26 ± 2 °C), a schedule that intends to model human recreational abuse. In addition, we have studied the effect of mephedrone in spatial learning and memory. The drug caused a transient decrease in weight gain. After the first dose, animals showed hypothermia but, after the subsequent doses, temperature raised over the values of saline-treated group. We observed the development of tolerance to these thermoregulatory effects of mephedrone. Mephedrone induced a reduction of the densities of dopamine (30% in the frontal cortex) and serotonin (40% in the frontal cortex and the hippocampus and 48% in the striatum) transporters without microgliosis. These deficits were also accompanied by a parallel decrease in the expression of tyrosine hydroxylase and tryptophan hydroxylase 2. These changes matched with a down-regulation of D 2 dopamine receptors in the striatum. Mephedrone also induced an oxidative stress evidenced by an increase of lipid peroxidation in the frontal cortex, and accompanied by a rise in glutathione peroxidase levels in all studied brain areas. Drug-treated animals displayed an impairment of the reference memory in the Morris water maze one week beyond the cessation of drug exposure, while the spatial learning process seems to be preserved. These findings raise concerns about the neuronal long-term effects of mephedrone. - Highlights: • We studied the dopaminergic and serotonergic neurotoxicity of mephedrone in rats. • Mephedrone induced a transient hypothermia following sustained hyperthermia. • In a weekend consumption pattern, mephedrone induced selective neurotoxicity. • Mephedrone generated oxidative stress. • Mephedrone induced an impairment in memory function

  7. Neuronal changes and oxidative stress in adolescent rats after repeated exposure to mephedrone

    Energy Technology Data Exchange (ETDEWEB)

    López-Arnau, Raúl; Martínez-Clemente, José [Department of Pharmacology and Therapeutic Chemistry (Pharmacology Section), Faculty of Pharmacy, University of Barcelona (Spain); Institute of Biomedicine (IBUB), Faculty of Pharmacy, University of Barcelona (Spain); Rodrigo, Teresa [Animal Experimentation Unit of Psychology and Pharmacy, University of Barcelona (Spain); Pubill, David [Department of Pharmacology and Therapeutic Chemistry (Pharmacology Section), Faculty of Pharmacy, University of Barcelona (Spain); Institute of Biomedicine (IBUB), Faculty of Pharmacy, University of Barcelona (Spain); Camarasa, Jorge, E-mail: jcamarasa@ub.edu [Department of Pharmacology and Therapeutic Chemistry (Pharmacology Section), Faculty of Pharmacy, University of Barcelona (Spain); Institute of Biomedicine (IBUB), Faculty of Pharmacy, University of Barcelona (Spain); Escubedo, Elena [Department of Pharmacology and Therapeutic Chemistry (Pharmacology Section), Faculty of Pharmacy, University of Barcelona (Spain); Institute of Biomedicine (IBUB), Faculty of Pharmacy, University of Barcelona (Spain)

    2015-07-01

    Mephedrone is a new designer drug of abuse. We have investigated the neurochemical/enzymatic changes after mephedrone administration to adolescent rats (3 × 25 mg/kg, s.c. in a day, with a 2 h interval between doses, for two days) at high ambient temperature (26 ± 2 °C), a schedule that intends to model human recreational abuse. In addition, we have studied the effect of mephedrone in spatial learning and memory. The drug caused a transient decrease in weight gain. After the first dose, animals showed hypothermia but, after the subsequent doses, temperature raised over the values of saline-treated group. We observed the development of tolerance to these thermoregulatory effects of mephedrone. Mephedrone induced a reduction of the densities of dopamine (30% in the frontal cortex) and serotonin (40% in the frontal cortex and the hippocampus and 48% in the striatum) transporters without microgliosis. These deficits were also accompanied by a parallel decrease in the expression of tyrosine hydroxylase and tryptophan hydroxylase 2. These changes matched with a down-regulation of D{sub 2} dopamine receptors in the striatum. Mephedrone also induced an oxidative stress evidenced by an increase of lipid peroxidation in the frontal cortex, and accompanied by a rise in glutathione peroxidase levels in all studied brain areas. Drug-treated animals displayed an impairment of the reference memory in the Morris water maze one week beyond the cessation of drug exposure, while the spatial learning process seems to be preserved. These findings raise concerns about the neuronal long-term effects of mephedrone. - Highlights: • We studied the dopaminergic and serotonergic neurotoxicity of mephedrone in rats. • Mephedrone induced a transient hypothermia following sustained hyperthermia. • In a weekend consumption pattern, mephedrone induced selective neurotoxicity. • Mephedrone generated oxidative stress. • Mephedrone induced an impairment in memory function.

  8. Antidepressant-like effect of oleanolic acid in mice exposed to the repeated forced swimming test.

    Science.gov (United States)

    Yi, Li-Tao; Li, Jing; Liu, Qing; Geng, Di; Zhou, Ya-Fei; Ke, Xiao-Qing; Chen, Huan; Weng, Lian-Jin

    2013-05-01

    The study aimed to explore the antidepressant-like effect of oleanolic acid and its possible mechanism related to the monoaminergic system and neurotrophin in mice exposed to the repeated forced swimming test (FST). Both the duration and the latency of immobility affected by oleanolic acid (10, 20 and 40 mg/kg) were evaluated in the FST repeated at intervals on days 1, 7 and 14, followed by neurochemical and brain-derived neurotrophic factor (BDNF) analyses in the mouse brain regions of frontal cortex and whole hippocampus. A repeated analysis of variance (ANOVA) indicated that over retesting the immobility time increased, whereas latency to immobility tended to decrease. Minute-by-minute analysis showed that immobility time also increased during the 4-min course of the test. In addition, post-hoc Dunnett's test demonstrated that sub-chronic and chronic, but not acute, oleanolic acid treatment reduced the immobility time (sub-chronic: 20 mg/kg, 43.5%; chronic: 10 mg/kg, 19.3%; 20 mg/kg, 31.8%) and increased the latency to immobility (sub-chronic: 10 mg/kg, 60.6%; 20 mg/kg, 80.1%; chronic: 10 mg/kg, 121.8%; 20 mg/kg, 140.8%; 40 mg/kg, 80.0%). Furthermore, chronic administration of oleanolic acid significantly increased serotonin (5-HT) levels (frontal cortex: 44.5%, 41.9%, 27.5% for 10, 20, 40 mg/kg; hippocampus: 57.2%, 80.9% for 10, 20 mg/kg), decreased 5-hydroxyindoleacetic acid (5-HIAA)/5-HT ratio (frontal cortex: 31.6%, 30.1%, 23.5%; hippocampus: 40.6%, 47.7%, 29.2% for 10, 20, 40 mg/kg) and elevated norepinephrine (NE) levels (hippocampus: 20 mg/kg, 45.4%) but did not alter dopamine (DA) levels. Moreover, BDNF levels in the two brain regions were also elevated by chronic oleanolic acid treatment (frontal cortex: 20 mg/kg, 67.2%; hippocampus: 10 mg/kg, 36.4%; 20 mg/kg, 55.1%). Taken together, these findings imply that functions of 5-HT, NE and BDNF may be involved in the antidepressant-like effect of oleanolic acid.

  9. Repeated stressor exposure enhances contextual fear memory in a beta-adrenergic receptor-dependent process and increases impulsivity in a non-beta receptor-dependent fashion.

    Science.gov (United States)

    Camp, Robert M; Johnson, John D

    2015-10-15

    Memory formation is promoted by stress via the release of norepinephrine and stimulation of beta-adrenergic receptors (β-ARs). Previous data demonstrate that repeated stressor exposure increases norepinephrine turnover and β-AR signaling within the amygdala, which led to the hypothesis that some stress-induced behavioral changes are likely due to facilitated associative learning. To test this, Fischer rats were exposed to chronic mild stress for four days. On day 5, subjects (including non-stressed controls) were injected with the beta-blocker propranolol or vehicle prior to conditioning in an operant box (animals receive two mild foot shocks) or passive avoidance apparatus (animals received a foot shock upon entry into the dark chamber). Twenty-four hours later, subjects were returned to the operant box for measurement of freezing or returned to the passive avoidance apparatus for measurement of latency to enter the dark chamber. Subjects were also tested in an open field to assess context-independent anxiety-like behavior. Animals exposed to chronic stress showed significantly more freezing behavior in the operant box than did controls, and this exaggerated freezing was blocked by propranolol during the conditioning trial. There was no effect of stress on behavior in the open field. Unexpectedly, retention latency was significantly reduced in subjects exposed to chronic stress. These results indicate that chronic exposure to stress results in complex behavioral changes. While repeated stress appears to enhance the formation of fearful memories, it also results in behavioral responses that resemble impulsive behaviors that result in poor decision-making. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Establishing the Test-Retest Reliability & Concurrent Validity for the Repeat Ice Skating Test (RIST) in Adolescent Male Ice Hockey Players

    Science.gov (United States)

    Power, Allan; Faught, Brent E.; Przysucha, Eryk; McPherson, Moira; Montelpare, William

    2012-01-01

    In this study the authors examine the test-retest reliability and concurrent validity of the Repeat Ice Skating Test (RIST). This was an on-ice field anaerobic test that measured average peak power and was validated with 3 anaerobic lab tests: (a) vertical jump, (b) the Margaria-Kalamen stair test, and (c) the Wingate Anaerobic Test. The…

  11. Repeatability of quantitative sensory testing in healthy cats in a clinical setting with comparison to cats with osteoarthritis.

    Science.gov (United States)

    Addison, Elena S; Clements, Dylan N

    2017-12-01

    Objectives The aim of this study was to evaluate the repeatability of quantitative sensory tests (QSTs) in a group of healthy untrained cats (n = 14) and to compare the results with those from cats with osteoarthritis (n = 7). Methods Peak vertical force (PVF) and vertical impulse were measured on a pressure plate system. Thermal sensitivity was assessed using a temperature-controlled plate at 7°C and 40°C. Individual paw lifts and overall duration of paw lifts were counted and measured for each limb. Paw withdrawal thresholds were measured using manual and electronic von Frey monofilaments (MVF and EVF, respectively) applied to the metacarpal or metatarsal pads. All measurements were repeated twice to assess repeatability of the tests. Results In healthy cats all tests were moderately repeatable. When compared with cats with osteoarthritis the PVF was significantly higher in healthy hindlimbs in repeat 1 but not in repeat 2. Cats with osteoarthritis of the forelimbs showed a decrease in the frequency of paw lifts on the 7°C plate compared with cats with healthy forelimbs, and the duration of paw lifts was significantly less than healthy forelimbs in the first repeat but not in the second repeat. Osteoarthritic limbs had significantly lower paw withdrawal thresholds with both MVF and EVF than healthy limbs. Conclusions and relevance QSTs are moderately repeatable in untrained cats. Kinetic gait analysis did not permit differentiation between healthy limbs and those with osteoarthritis, but thermal sensitivity testing (cold) does. Sensory threshold testing can differentiate osteoarthritic and healthy limbs, and may be useful in the diagnosis and monitoring of this condition in cats in the clinical setting.

  12. [Necessity of repeated roll test in horizontal semicircular canalithasis positioned diagnosis].

    Science.gov (United States)

    Lu, H H; Zhao, Y; Chen, T S; Xu, K X; Wang, W; Liu, Q; Wen, C; Li, S S; Li, X J; Han, X; Lin, P

    2016-04-07

    To investigate the influence of repeated roll test in horizontal semicircular canalithasis(HSC-Can) positioned diagnosis, so as to investigate the cecessity of repeated roll test. The patients with a chief complaint of positional vertigo accepted two consecutive cycles roll test, the evoked nystagmus characteristics of each cycle recorded by video-nystagmuograph(VNG), whose direction, intensity, time and other parameters characteristics were analyzed in 51 HSC-Can. Horizontal nystagmus in the same direction with turning were induced in HSC-Can roll test. In 51 HSC-Can, roll test cycle 1 and cycle 2 induced nystagmus same strength side in 26 cases(51.0%), of which 19 cases with stronger nystagmus intensity in cycle 2, another 7 cases were weaker; the opposite strength side of the two loops induced nystagmus, and cycle 1 evoked nystagmus intensity were weaker than cycle 2, based on cycle 2 results determined HSC-Can affected side in 25 cases (49.0%). Lesion and normal side in cycle 1 induced nystagmus duration (x±s, the same below) were (13.4±11.5)s and (14.1±9.9)s, respectively intensity (18.1±22.4)°/s and (13.0±12.0)°/s; as in cycle 2 induced nystagmus duration was (20.7±10.2)s and (18.0±12.0)s, strength respectively(40.4±28.0)°/s and (15.6 ±11.2)°/s. Cycle 2 ipsilateral rotor position evoked nystagmus showed longer duration and stronger intensity than cycle 1. Between two cycle induced ipsilateral nystagmus duration, intensity differences were statistically significant (t values were -4.233 and -5.154, P=0.000). 51 HSC-Can patients, 44 patients selected repositioning maneuver, after 1-2 times of maneuver, 41 cases (93.2%) showed complete resolution of symptoms, all cases's symptoms were improved; other 7 patients selected medication only. The proposed suspicious HSC-Can patients should receive at least two cycles roll test, and mainly in the second cycle could determine the location of the responsible semicircular canals.

  13. Reliability characteristics and applicability of a repeated sprint ability test in male young soccer players

    DEFF Research Database (Denmark)

    Castagna, Carlo; Francini, Lorenzo; Krustrup, Peter

    2018-01-01

    The aim of this study was to examine the usefulness and reliability characteristics of a repeated sprint ability test considering 5 line sprints of 30-m interspersed with 30-s of active recovery in non-elite outfield young male soccer players. Twenty-six (age 14.9±1.2 years, height 1.72±0.12 cm......, body mass 62.2±5.1 kg) players were tested 48 hours and 7 days apart for 5x30-m performance over 5 trials (T1-T5). Short- (T1-T2) and long-term reliability (T1-T3-T4-T5) were assessed with Intraclass Correlation Coefficient (ICC) and with typical error for measurement (TEM). Short- and long...... study revealed that the 5x30-m sprint test is a reliable field test in the short and long-term when the sum of sprint times and the best sprint performance are considered as outcome variables. Sprint performance decrements variables showed large variability across trials....

  14. Repeated use of computerized case simulations in a test format does not present a security risk.

    Science.gov (United States)

    Lynch, T G; Zadalis, R J; Schneider, P D

    1999-03-01

    Computer-based examination formats permit evaluation of patient care strategies in a realistic context. Because such examinations are complex and difficult to develop, the same case simulations must often be used on multiple occasions. To determine if repeated, serial administration of computerized case simulations influences performance, 8 simulations were administered over 2 consecutive years to 252 third-year medical students at the conclusion of 16 surgical clerkship rotations (8 per year). One-way analyses of variance were used to compare scores across rotations during the year and to compare scores between 2 consecutive academic years. Scheffe pairwise comparisons were used to identify trends within each academic year. The data demonstrate an increase in scores across rotations during the year. There is, however, no difference between scores in successive years. The data are consistent with an increase in knowledge during the course of the year, without evidence that test information transfer influences the performance of successive classes.

  15. Repeat confirmatory testing for persons with discordant whole blood and oral fluid rapid HIV test results: findings from post marketing surveillance.

    Science.gov (United States)

    Wesolowski, Laura G; Mackellar, Duncan A; Ethridge, Steven F; Zhu, Julia H; Owen, S Michele; Sullivan, Patrick S

    2008-02-06

    Reactive oral fluid and whole blood rapid HIV tests must be followed with a confirmatory test (Western blot (WB), immunofluorescent assay (IFA) or approved nucleic acid amplification test (NAAT)). When the confirmatory result is negative or indeterminate (i.e. discordant with rapid result), repeat confirmatory testing should be conducted using a follow-up specimen. Previous reports have not described whether repeat testing adequately resolves the HIV-infection status of persons with discordant results. Post-marketing surveillance was conducted in 368 testing sites affiliated with 14 state and 2 city health departments from August 11, 2004 to June 30, 2005 and one health department through December 31, 2005. For persons with discordant results, data were collected on demographics, risk behaviors, HIV test results and specimen types. Persons with repeat confirmatory results were classified as HIV-infected or uninfected. Regression models were created to assess risk factors for not having repeat testing. Of 167,371 rapid tests conducted, 2589 (1.6%) were reactive: of these, 2417 (93%) had positive WB/IFA, 172 (7%) had negative or indeterminate WB/IFA. Of 89/172 (52%) persons with a repeat confirmatory test: 17 (19%) were HIV-infected, including 3 with indeterminate WB and positive NAAT; 72 (81%) were uninfected, including 12 with repeat indeterminate WB. Factors associated with HIV-infection included having an initial indeterminate WB/IFA (vs. negative) (ptest [adjusted OR 2.6, 95% CI (1.3, 4.9)]. Though only half of persons with discordant results had repeat confirmatory testing, of those who did, nearly one in five were HIV-infected. These findings underscore the need for rapid HIV testing programs to increase repeat confirmatory testing for persons with discordant results. Because of the lower sensitivity of oral fluid WBs, confirmatory testing following a reactive rapid test should be conducted using serum or plasma, when possible.

  16. Test-retest repeatability of the pupil light response to blue and red light stimuli in normal human eyes using a novel pupillometer

    Directory of Open Access Journals (Sweden)

    Kristina eHerbst

    2011-02-01

    Full Text Available In this study, we evaluated the repeatability of pupil responses to colored light stimuli in healthy subjects using a prototype chromatic pupillometer. One eye of 10 healthy subjects was tested twice in the same day using monochromatic light exposure at 2 selected wavelengths (660 nm and 470 nm, intensity 300 cd/m2 presented continuously for 20 seconds. Pupil responses were recorded in real time before, during and after light exposure. Maximal contraction amplitude and sustained contraction amplitude were calculated. In addition, we quantified the summed pupil response during continuous light stimulation as the total area between a reference line representing baseline pupil size and the line representing actual pupil size over 20 seconds (area under the curve. There was no significant difference in the repeated measure compared to the first test for any of the pupil response parameters. In conclusion, we have developed a novel prototype of color pupillometer which demonstrates good repeatability in evoking and recording the pupillary response to a bright blue and red light stimulus.

  17. The utility of repeat enzyme immunoassay testing for the diagnosis of Clostridium difficile infection: A systematic review of the literature

    Directory of Open Access Journals (Sweden)

    P S Garimella

    2012-01-01

    Full Text Available Over the last 20 years, the prevalence of healthcare-associated Clostridium difficile (C. diff disease has increased. While multiple tests are available for the diagnosis of C. diff infection, enzyme immunoassay (EIA testing for toxin is the most used. Repeat EIA testing, although of limited utility, is common in medical practice. To assess the utility of repeat EIA testing to diagnose C. diff infections. Systematic literature review. Eligible studies performed >1 EIA test for C. diff toxin and were published in English. Electronic searches of MEDLINE and EMBASE were performed and bibliographies of review articles and conference abstracts were hand searched. Of 805 citations identified, 32 were reviewed in detail and nine were included in the final review. All studies except one were retrospective chart reviews. Seven studies had data on number of participants (32,526, and the overall reporting of test setting and patient characteristics was poor. The prevalence of C. diff infection ranged from 9.1% to 18.5%. The yield of the first EIA test ranged from 8.4% to 16.6%, dropping to 1.5-4.7% with a second test. The utility of repeat testing was evident in outbreak settings, where the yield of repeat testing was 5%. Repeat C. diff testing for hospitalized patients has low clinical utility and may be considered in outbreak settings or when the pre-test probability of disease is high. Future studies should aim to identify patients with a likelihood of disease and determine the utility of repeat testing compared with empiric treatment.

  18. Analgesia induced by repeated exposure to low dose X-rays in mice, and involvement of the accessory olfactory system in modulation of the radiation effects

    International Nuclear Information System (INIS)

    Miyachi, Yukihisa; Yamada, Takeshi

    1997-01-01

    The effects of low-dose X-rays on mouse nociceptive behavior were examined using a formalin injected test which rated the amount of time the animals spent licking the injected hind-paw. Male ICR White Swiss mice showed a marked suppression of licking behavior after repeated low-dose X-irradiation (5 cGy/day, 6 consecutive days). The most profound effect was observed on the day 30 after irradiation. The decline of licking behavior, however, was not observed at all following olfactory bulbectomy or vomeronasal tract cut. The analgesic effects could be observed in writhing animals administered acetic-acid intraperitoneally. Moreover, analgesia was totally blocked by the administration of N-nitro-L-arginine, a nitric oxide synthase inhibitor, to accessory olfactory bulbs prior to the exposure. The present results indicate that the olfactory system plays an important role in modulation of radiation-induced analgesia, and a possible involvement of nitric oxide in the formation of recognition memory subjected to repeated X-rays. Relatively higher doses (5 cGy x 9 days, 5 cGy x 12 days), however, did not induce such effects, namely, the decline of nociceptive response was limited to the animals irradiated with the smaller dose. (author)

  19. Deployment Repeatability

    Science.gov (United States)

    2016-04-01

    evaluating the deployment repeatability builds upon the testing or analysis of deployment kinematics (Chapter 6) and adds repetition. Introduction...material yield or failure during a test. For the purposes of this chapter, zero shift will refer to permanent changes in the structure, while reversible ...the content of other chapters in this book: Gravity Compensation (Chapter 4) and Deployment Kinematics and Dynamics (Chapter 6). Repeating the

  20. Implementation of repeat HIV testing during pregnancy in southwestern Kenya: progress and missed opportunities.

    Science.gov (United States)

    Rogers, Anna J; Akama, Eliud; Weke, Elly; Blackburn, Justin; Owino, George; Bukusi, Elizabeth A; Oyaro, Patrick; Kwena, Zachary A; Cohen, Craig R; Turan, Janet M

    2017-12-01

    Repeat HIV testing during the late antenatal period is crucial to identify and initiate treatment for pregnant women with incident HIV infection to prevent perinatal HIV transmission and keep mothers alive. In 2012, the Kenya Ministry of Health adopted international guidelines suggesting that pregnant women be offered retesting three months after an initial negative HIV test. Our objectives were to determine the current rate of antenatal repeat HIV testing; identify successes, missed opportunities and factors associated with retesting; and estimate the incidence of HIV during pregnancy. Retrospective analysis of longitudinal data was conducted for a cohort of 2145 women attending antenatal care clinic at a large district hospital in southwestern Kenya. Data were abstracted from registers for all women who attended the clinic from the years 2011 to 2014. Although 90.2% of women first came to clinic prior to their third trimester and 27.5% had at least four clinic visits, 58.0% of all women went to delivery without a retest. Missed opportunities for retesting included not returning to clinic at all, not returning when eligible, or late gestational age (>28 weeks) at first clinic visit making them ineligible for retesting (accounting for 14.2%, 26.8% and 9.6% of all clinic attendees respectively); and failure to be retested even when eligible at one or more visits (accounting for 73.2% of eligible returnees). Being unmarried and aged 20 or younger was associated with an increase in mean gestational age of first visit by 2.52 weeks (95% CI: 1.56, 3.48) and a 2.59 increased odds (95% CI: 1.90, 3.54) of failing to return to clinic, compared to those who were married and over 20 years of age. On retest, two women tested HIV positive, suggesting an incidence rate of 4.4 per 100 person-years. After adjusting for potential confounders, only later year of last menstrual period (2013 vs. 2012 and 2011) was associated with retesting. Adoption of retesting guidelines in 2012

  1. Adaptation of the pituitary-adrenal axis to daily repeated forced swim exposure in rats is dependent on the temperature of water.

    Science.gov (United States)

    Rabasa, Cristina; Delgado-Morales, Raúl; Gómez-Román, Almudena; Nadal, Roser; Armario, Antonio

    2013-11-01

    Comparison of exposure to certain predominantly emotional stressors reveals a qualitatively similar neuroendocrine response profile as well as a reduction of physiological responses after daily repeated exposure (adaptation). However, particular physical components of the stressor may interfere with adaptation. As defective adaptation to stress can enhance the probability to develop pathologies, we studied in adult male rats (n = 10/group) swimming behavior (struggling, immobility and mild swim) and physiological responses (ACTH, corticosterone and rectal temperature) to daily repeated exposure to forced swim (20 min, 13 d) at 25 or 36 °C (swim25 or swim36). Rats were repeatedly blood-sampled by tail-nick and hormones measured by radioimmunoassay. Some differences were observed between the two swim temperature groups after the first exposure to forced swim: (a) active behaviors were greater in swim25 than swim36 groups; (b) swim25 but not swim36 caused hypothermia; and (c) swim36 elicited the same ACTH response as swim25, but plasma corticosterone concentration was lower for swim36 at 30 min post-swim. After daily repeated exposure, adaptation in ACTH secretion was observed with swim36 already on day 4, whereas with swim25 adaptation was not observed until day 13 and was of lower magnitude. Nevertheless, after repeated exposure to swim25 a partial protection from hypothermia was observed and the two swim conditions resulted in progressive reduction of active behaviors. Thus, daily repeated swim at 25 °C impairs adaptation of the hypothalamic-pituitary-adrenal axis as compared to swim at 36 °C, supporting the hypothesis that certain physical components of predominantly emotional stressors can interfere with the process of adaptation.

  2. Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing

    Science.gov (United States)

    Montgomery, Eliza L.; Calle, Luz Marina; Curran, Jerone C.; Kolody, Mark R.

    2011-01-01

    Evaluation of metal-based structures has long relied on atmospheric exposure test sites to determine corrosion resistance in marine environments. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating salt spray and ultraviolet (UV) radiation, and exposing the metal to continuous or cyclic conditions of the corrosive environment. Their success for correlation to atmospheric exposure is often a concern when determining the timescale to which the accelerated tests can be related. Accelerated laboratory testing, which often focuses on the electrochemical reactions that occur during corrosion conditions, has yet to be universally accepted as a useful tool in predicting the long term service life of a metal despite its ability to rapidly induce corrosion. Although visual and mass loss methods of evaluating corrosion are the standard and their use is imperative, a method that correlates timescales from atmospheric exposure to accelerated testing would be very valuable. This work uses surface chemistry to interpret the chemical changes occurring on low carbon steel during atmospheric and accelerated corrosion conditions with the objective of finding a correlation between its accelerated and long-term corrosion performance. The current results of correlating data from marine atmospheric exposure conditions at the Kennedy Space Center beachside corrosion test site, alternating seawater spray, and immersion in typical electrochemical laboratory conditions, will be presented. Key words: atmospheric exposure, accelerated corrosion testing, alternating seawater spray, marine, correlation, seawater, carbon steel, long-term corrosion performance prediction, X-ray photoelectron spectroscopy.

  3. Study of four week repeated dose toxic test of Sweet Bee Venom in Beagle Dogs

    Directory of Open Access Journals (Sweden)

    Jae-Seuk Park

    2010-12-01

    . The proper high dosage of Sweet BV for the thirteen week repeated test in Beagle dogs may be 0.28㎎/㎏ in one time. Conclusion: Above findings suggest that Sweet BV is relatively safe treatment medium. Further studies on the subject should be conducted to yield more concrete evidences.

  4. Repeatability indices for the Adams D-15 test for colour-normal and colour-defective adults.

    Science.gov (United States)

    Hovis, Jeffery K; Ramaswamy, Shankaran; Anderson, Matthew

    2004-07-01

    The Adams desaturated D-15 test was administered to individuals with normal colour vision or with congenital red-green colour vision defects to establish the repeatability of the test. One hundred subjects with normal colour vision and 64 subjects with defective colour vision participated in the study. Results were analysed from two different sessions to determine the repeatability of the test for different pass/fail criteria. The test was scored using both visual inspection of the score sheet and the modified Colour Difference Vector analysis (CDV) program. For both subject groups, the repeatability was lowest when a perfect arrangement was required for a pass and improved as more errors were allowed. The improvement in repeatability was greatest as the failure criterion changed from 'any mistake' to 'more than two crossings'. The kappa coefficient for the reliability of the defect classification was 0.38 for visual inspection and 0.59 for the CDV analysis. All the protans who failed the test at both sessions were classified correctly. Approximately 98 per cent of the colour-normals and 82 per cent of the colour-defectives would have the same pass/fail outcome on the Adams D-15 test conducted several days apart when the failure criterion was either one or more or two or more crossings. Individuals who make less than four crossings on the Adams D-15 should repeat the test to ensure confidence in the pass/fail result.

  5. Repeated change-of-direction test for collegiate male soccer players.

    Science.gov (United States)

    Mizuguchi, S; Gray, H; Calabrese, L S; Haff, G G; Sands, W A; Ramsey, M W; Cardinale, M; Stone, M H

    2014-08-01

    The aim of the study was to investigate the applicability of a repeated change-of-direction (RCoD) test for NCAA Division-I male soccer players. The RCoD test consisted of 5 diagonal direction changes per repetition with a soccer ball to be struck at the end. Each player performed 15 repetitions with approximately 10 seconds to jog back between repetitions. Data were collected in two sessions. In the first session, 13 players were examined for heart rate responses and blood lactate concentrations. In the second session, 22 players were examined for the test's ability to discriminate the primary from secondary players (78.0±16.1 and 10.4±13.3 minutes per match, respectively). Heart rate data were available only from 9 players due to artifacts. The peak heart rate (200.2±6.6 beats∙min-1: 99.9±3.0% maximum) and blood lactate concentration (14.8±2.4 mmol∙L-1 immediately after) resulted in approximately 3.5 and 6.4-fold increases from the resting values, respectively. These values appear comparable to those during intense periods of soccer matches. In addition, the average repetition time of the test was found to discriminate the primary (4.85±0.23 s) from the secondary players (5.10±0.24 s) (P=0.02). The RCoD test appears to induce physiological responses similar to intense periods of soccer matches with respect to heart rate and blood lactate concentration. Players with better average repetition times tend to be those who play major minutes.

  6. Effect of replacing sugar with non-caloric sweeteners in beverages on the reward value after repeated exposure.

    Directory of Open Access Journals (Sweden)

    Sanne Griffioen-Roose

    Full Text Available BACKGROUND: The reward value of food is partly dependent on learned associations. It is not yet known whether replacing sugar with non-caloric sweeteners in food is affecting long-term acceptance. OBJECTIVE: To determine the effect of replacing sugar with non-caloric sweeteners in a nutrient-empty drink (soft drink versus nutrient-rich drink (yoghurt drink on reward value after repeated exposure. DESIGN: We used a randomized crossover design whereby forty subjects (15 men, 25 women with a mean ± SD age of 21 ± 2 y and BMI of 21.5 ± 1.7 kg/m(2 consumed a fixed portion of a non-caloric sweetened (NS and sugar sweetened (SS versions of either a soft drink or a yoghurt drink (counterbalanced for breakfast which were distinguishable by means of colored labels. Each version of a drink was offered 10 times in semi-random order. Before and after conditioning the reward value of the drinks was assessed using behavioral tasks on wanting, liking, and expected satiety. In a subgroup (n=18 fMRI was performed to assess brain reward responses to the drinks. RESULTS: Outcomes of both the behavioral tasks and fMRI showed that conditioning did not affect the reward value of the NS and SS versions of the drinks significantly. Overall, subjects preferred the yoghurt drinks to the soft drinks and the ss drinks to the NS drinks. In addition, they expected the yoghurt drinks to be more satiating, they reduced hunger more, and delayed the first eating episode more. Conditioning did not influence these effects. CONCLUSION: Our study showed that repeated consumption of a non-caloric sweetened beverage, instead of a sugar sweetened version, appears not to result in changes in the reward value. It cannot be ruled out that learned associations between sensory attributes and food satiating capacity which developed preceding the conditioning period, during lifetime, affected the reward value of the drinks.

  7. Effect of replacing sugar with non-caloric sweeteners in beverages on the reward value after repeated exposure.

    Science.gov (United States)

    Griffioen-Roose, Sanne; Smeets, Paul A M; Weijzen, Pascalle L G; van Rijn, Inge; van den Bosch, Iris; de Graaf, Cees

    2013-01-01

    The reward value of food is partly dependent on learned associations. It is not yet known whether replacing sugar with non-caloric sweeteners in food is affecting long-term acceptance. To determine the effect of replacing sugar with non-caloric sweeteners in a nutrient-empty drink (soft drink) versus nutrient-rich drink (yoghurt drink) on reward value after repeated exposure. We used a randomized crossover design whereby forty subjects (15 men, 25 women) with a mean ± SD age of 21 ± 2 y and BMI of 21.5 ± 1.7 kg/m(2) consumed a fixed portion of a non-caloric sweetened (NS) and sugar sweetened (SS) versions of either a soft drink or a yoghurt drink (counterbalanced) for breakfast which were distinguishable by means of colored labels. Each version of a drink was offered 10 times in semi-random order. Before and after conditioning the reward value of the drinks was assessed using behavioral tasks on wanting, liking, and expected satiety. In a subgroup (n=18) fMRI was performed to assess brain reward responses to the drinks. Outcomes of both the behavioral tasks and fMRI showed that conditioning did not affect the reward value of the NS and SS versions of the drinks significantly. Overall, subjects preferred the yoghurt drinks to the soft drinks and the ss drinks to the NS drinks. In addition, they expected the yoghurt drinks to be more satiating, they reduced hunger more, and delayed the first eating episode more. Conditioning did not influence these effects. Our study showed that repeated consumption of a non-caloric sweetened beverage, instead of a sugar sweetened version, appears not to result in changes in the reward value. It cannot be ruled out that learned associations between sensory attributes and food satiating capacity which developed preceding the conditioning period, during lifetime, affected the reward value of the drinks.

  8. INDUSTRIAL ROBOT REPEATABILITY TESTING WITH HIGH SPEED CAMERA PHANTOM V2511

    Directory of Open Access Journals (Sweden)

    Jerzy Józwik

    2016-12-01

    Full Text Available Apart from accuracy, one of the parameters describing industrial robots is positioning accuracy. The parameter in question, which is the subject of this paper, is often the decisive factor determining whether to apply a given robot to perform certain tasks or not. Articulated robots are predominantly used in such processes as: spot weld-ing, transport of materials and other welding applications, where high positioning repeatability is required. It is therefore essential to recognise the parameter in question and to control it throughout the operation of the robot. This paper presents methodology for robot positioning accuracy measurements based on vision technique. The measurements were conducted with Phantom v2511 high-speed camera and TEMA Motion software, for motion analysis. The object of the measurements was a 6-axis Yaskawa Motoman HP20F industrial robot. The results of measurements obtained in tests provided data for the calculation of positioning accuracy of the robot, which was then juxtaposed against robot specifications. Also analysed was the impact of the direction of displacement on the value of attained pose errors. Test results are given in a graphic form.

  9. Attrition from Web-Based Cognitive Testing: A Repeated Measures Comparison of Gamification Techniques.

    Science.gov (United States)

    Lumsden, Jim; Skinner, Andy; Coyle, David; Lawrence, Natalia; Munafo, Marcus

    2017-11-22

    The prospect of assessing cognition longitudinally and remotely is attractive to researchers, health practitioners, and pharmaceutical companies alike. However, such repeated testing regimes place a considerable burden on participants, and with cognitive tasks typically being regarded as effortful and unengaging, these studies may experience high levels of participant attrition. One potential solution is to gamify these tasks to make them more engaging: increasing participant willingness to take part and reducing attrition. However, such an approach must balance task validity with the introduction of entertaining gamelike elements. This study aims to investigate the effects of gamelike features on participant attrition using a between-subjects, longitudinal Web-based testing study. We used three variants of a common cognitive task, the Stop Signal Task (SST), with a single gamelike feature in each: one variant where points were rewarded for performing optimally; another where the task was given a graphical theme; and a third variant, which was a standard SST and served as a control condition. Participants completed four compulsory test sessions over 4 consecutive days before entering a 6-day voluntary testing period where they faced a daily decision to either drop out or continue taking part. Participants were paid for each session they completed. A total of 482 participants signed up to take part in the study, with 265 completing the requisite four consecutive test sessions. No evidence of an effect of gamification on attrition was observed. A log-rank test showed no evidence of a difference in dropout rates between task variants (χ 2 2 =3.0, P=.22), and a one-way analysis of variance of the mean number of sessions completed per participant in each variant also showed no evidence of a difference (F 2,262 =1.534, P=.21, partial η 2 =0.012). Our findings raise doubts about the ability of gamification to reduce attrition from longitudinal cognitive testing studies

  10. Changes in background impair fluency-triggered positive affect: a cross-cultural test using a mere-exposure paradigm.

    Science.gov (United States)

    Ishii, Keiko

    2011-04-01

    This study examined whether repeated exposure would enhance positive evaluations when only a part of a stimulus (e.g., the central object) was identical to a previously presented stimulus. Japanese and American participants were exposed to photographs of animals with scenery, then asked their preferences for each of four types of photographs of animals (photographs of animals with the original scenery, photographs of animals without scenery, photographs of animals with novel scenery, and photographs of animals not depicted previously). Finally, their recognition of the animals presented in the exposure phase was tested. Members of both groups showed the mere-exposure effect for the first two types of stimuli, irrespective of stimulus recognition accuracy, whereas this effect was not observed for animals presented with novel scenery. This suggests that changes in background impair positive affect as a result of repeated exposure.

  11. Historical estimates of external gamma exposure and collective external gamma exposure from testing at the Nevada Test Site. I. Test series through HARDTACK II, 1958

    Energy Technology Data Exchange (ETDEWEB)

    Anspaugh, L.R.; Church, B.W.

    1985-12-01

    In 1959, the Test Manager's Committee to Establish Fallout Doses calculated estimated external gamma exposure at populated locations based upon measurements of external gamma-exposure rate. Using these calculations and estimates of population, we have tabulated the collective estimated external gamma exposures for communities within established fallout patterns. The total collective estimated external gamma exposure is 85,000 person-R. The greatest collective exposures occurred in three general areas: Saint George, Utah; Ely, Nevada; and Las Vegas, Nevada. Three events, HARRY (May 19, 1953), BEE (March 22, 1955), and SMOKY (August 31, 1957), accounted for over half of the total collective estimated external gamma exposure. The bases of the calculational models for external gamma exposure of ''infinite exposure,'' ''estimated exposure,'' and ''one year effective biological exposure'' are explained. 4 figs., 7 tabs.

  12. Historical estimates of external gamma exposure and collective external gamma exposure from testing at the Nevada Test Site. I. Test series through HARDTACK II, 1958

    International Nuclear Information System (INIS)

    Anspaugh, L.R.; Church, B.W.

    1986-01-01

    In 1959, the Test Manager's Committee to Establish Fallout Doses calculated estimated external gamma exposure at populated locations based upon measurements of external gamma-exposure rate. Using these calculations and estimates of population, we have tabulated the collective estimated external gamma exposures for communities within established fallout patterns. The total collective estimated external gamma exposure is 85,000 person-R. The greatest collective exposures occurred in three general areas: Saint George, UT; Ely, NV; and Las Vegas, NV. Three events, HARRY (19 May 1953), BEE (22 March 1955), and SMOKY (31 August 1957), accounted for more than half the total collective estimated external gamma exposure. The bases of the calculational models for external gamma exposure of infinite exposure, estimated exposure, and 1-yr effective biological exposure are explained

  13. Historical estimates of external gamma exposure and collective external gamma exposure from testing at the Nevada Test Site. I. Test series through HARDTACK II, 1958

    International Nuclear Information System (INIS)

    Anspaugh, L.R.; Church, B.W.

    1985-12-01

    In 1959, the Test Manager's Committee to Establish Fallout Doses calculated estimated external gamma exposure at populated locations based upon measurements of external gamma-exposure rate. Using these calculations and estimates of population, we have tabulated the collective estimated external gamma exposures for communities within established fallout patterns. The total collective estimated external gamma exposure is 85,000 person-R. The greatest collective exposures occurred in three general areas: Saint George, Utah; Ely, Nevada; and Las Vegas, Nevada. Three events, HARRY (May 19, 1953), BEE (March 22, 1955), and SMOKY (August 31, 1957), accounted for over half of the total collective estimated external gamma exposure. The bases of the calculational models for external gamma exposure of ''infinite exposure,'' ''estimated exposure,'' and ''one year effective biological exposure'' are explained. 4 figs., 7 tabs

  14. Potential for the development of tolerance by Aspergillus amstelodami, A. repens and A. ruber after repeated exposure to potassium sorbate.

    Science.gov (United States)

    Viñas, I; Morlans, I; Sanchis, V

    1990-01-01

    Three strains of A. amstelodami, A. repens and A. ruber were exposed to various levels of potassium sorbate, and the MICs were determined. Selected strains of the molds were then repeatedly exposed to subinhibitory levels of the compound to determine whether increased tolerance might develop. The MIC of sorbate (pH 5.5 or 6.5) for 3 species of Aspergillus was 0.07%. Increasing levels of sorbate resulted in increasing growth suppression of the molds. The 3 Aspergillus species were tested for increased tolerance to potassium sorbate, and none was found. They developed a slight increase in tolerance dependent upon pH and the mold strain by subculturing at low levels of sorbate.

  15. Clinical Utilization of Repeated Open Application Test Among American Contact Dermatitis Society Members.

    Science.gov (United States)

    Brown, Gabrielle E; Botto, Nina; Butler, Daniel C; Murase, Jenny E

    2015-01-01

    The repeated open application test (ROAT) provides useful information regarding allergens in suspected cases of allergic contact dermatitis; however, standardized methodology has not been established. The aim of this study was to assess how ROAT is used in clinical and research settings. We distributed a survey regarding ROAT practice to the American Contact Dermatitis Society and conducted a literature review of ROAT utilization in research. A total of 67 American Contact Dermatitis Society members participated in the survey. Respondents most frequently recommend application of leave-on products twice daily (46.0%) and rinse-off products once daily (43.5%). The most commonly used anatomical sites include the forearm (38.7%) and antecubital fossa (32.3%). Most respondents continue ROAT for 1 (49.2%) or 2 weeks (31.7%). Literature review of 32 studies (26 leave-on, 6 rinse-off) revealed that application frequency is most common at twice daily for both leave-on (96.2%) and rinse-off (50.0%) products. The most common anatomical site is the forearm (62.5%), with an overall study duration of 3 to 4 weeks (65.6%). When comparing ROAT clinical and research practice, the majority trend was consistent for leave-on product application frequency and anatomical site, but not for rinse-off product application frequency, or overall duration. Further research is needed to determine best practice recommendations.

  16. A study on the evaluation of dynamic stress intensity factor in repeated impact bending test

    International Nuclear Information System (INIS)

    Sim, Jae Ki; Cho, Gyu Jae; Han, Gill Young

    1988-01-01

    The purpose of the present paper was to establish the evaluation of the dynamic stress intensity factor in repeated impact three point bending test. Contact force between the impact bar and the cracked beam (simple supported beam) was analyzed by the using Hertz's contact law. In order to clarify the validity of theoretical analysis, experiments of dynamic stress intensity factir k I (t) are made on the cracked beam. The results obtained from this study are as follow: 1. In case of impact force analysis the theoretical result was obtained by the use of the Hertz's contact law. It's result was agreemant with the experimental result. Particularly, it was good agreement in the low impact velocity range. 2. The time variation of the dynamic stress intensity was determined by using the simple formula developed in this pqper. And the validity of it's result can be confirmed by experiment. Particlarly, this theoretical analysis was a good agreement to actual phenomena on from 0.3 msec to 0.65 msec. (Author)

  17. The reinforcing value of vegetables does not increase with repeated exposure during a randomized controlled provided vegetable intervention among overweight and obese adults

    Science.gov (United States)

    Objective: The primary aim of this randomized controlled trial is to determine whether the relative reinforcing value (RRV) of vegetables compared to a snack food can be increased through repeated exposure (incentive sensitization) to amounts of vegetables recommended by the Dietary Guidelines for A...

  18. Is repeated exposure the holy grail for increasing children's vegetable intake? Lessons learned from a Dutch childcare intervention using various vegetable preparations

    NARCIS (Netherlands)

    Zeinstra, Gertrude G.; Vrijhof, Milou; Kremer, Stefanie

    2018-01-01

    Children's failure to eat enough vegetables highlights the need for effective interventions encouraging this behaviour. The aim of this study was to investigate the effect of repeated exposure to three a priori unfamiliar vegetables, each prepared in two ways, on children's vegetable acceptance in a

  19. Identification of genomic biomarkers for anthracycline-induced cardiotoxicity in human iPSC-derived cardiomyocytes: an in vitro repeated exposure toxicity approach for safety assessment

    NARCIS (Netherlands)

    Chaudhari, U.; Nemade, H.; Wagh, V.; Ellis, J.K.; Srinivasan, S.; Louisse, J.

    2016-01-01

    The currently available techniques for the safety evaluation of candidate drugs are usually cost-intensive and time-consuming and are often insufficient to predict human relevant cardiotoxicity. The purpose of this study was to develop an in vitro repeated exposure toxicity methodology allowing the

  20. Repeat confirmatory testing for persons with discordant whole blood and oral fluid rapid HIV test results: findings from post marketing surveillance.

    Directory of Open Access Journals (Sweden)

    Laura G Wesolowski

    Full Text Available BACKGROUND: Reactive oral fluid and whole blood rapid HIV tests must be followed with a confirmatory test (Western blot (WB, immunofluorescent assay (IFA or approved nucleic acid amplification test (NAAT. When the confirmatory result is negative or indeterminate (i.e. discordant with rapid result, repeat confirmatory testing should be conducted using a follow-up specimen. Previous reports have not described whether repeat testing adequately resolves the HIV-infection status of persons with discordant results. METHODOLOGY: Post-marketing surveillance was conducted in 368 testing sites affiliated with 14 state and 2 city health departments from August 11, 2004 to June 30, 2005 and one health department through December 31, 2005. For persons with discordant results, data were collected on demographics, risk behaviors, HIV test results and specimen types. Persons with repeat confirmatory results were classified as HIV-infected or uninfected. Regression models were created to assess risk factors for not having repeat testing. PRINCIPAL FINDINGS: Of 167,371 rapid tests conducted, 2589 (1.6% were reactive: of these, 2417 (93% had positive WB/IFA, 172 (7% had negative or indeterminate WB/IFA. Of 89/172 (52% persons with a repeat confirmatory test: 17 (19% were HIV-infected, including 3 with indeterminate WB and positive NAAT; 72 (81% were uninfected, including 12 with repeat indeterminate WB. Factors associated with HIV-infection included having an initial indeterminate WB/IFA (vs. negative (p<0.001 and having an initial oral fluid WB (vs. serum (p<0.001. Persons who had male-female sex (vs. male-male sex were at increased risk for not having a repeat test [adjusted OR 2.6, 95% CI (1.3, 4.9]. CONCLUSIONS: Though only half of persons with discordant results had repeat confirmatory testing, of those who did, nearly one in five were HIV-infected. These findings underscore the need for rapid HIV testing programs to increase repeat confirmatory testing for

  1. Effects of Diet and Genetics on Growth Performance of Pigs in Response to Repeated Exposure to Heat Stress

    Directory of Open Access Journals (Sweden)

    Wendy M. Rauw

    2017-10-01

    Full Text Available Heat stress (HS is one of the costliest issues in the U.S. pork industry. Aims of the present study were to determine the consequences of repeated exposure to HS on growth performance, and the effects of a high fiber diet, the genetic potential for high lean tissue accretion, and the genetic potential for residual feed intake (RFI on resilience to HS. Barrows (n = 97 from three genetic lines (commercial, high RFI, low RFI where subjected three times to a 4-day HS treatment (HS1, HS2, and HS3 which was preceded by a 9-day neutral (TN adaptation period (TN1 and alternated by 7-day periods of neutral temperatures (TN2, TN3, and TN4. Body weight gain (BWG, feed intake (FI, feed conversion efficiency (FCE, RFI, and the drop in BWG and FI between TN and HS were estimated for each period, and slaughter traits were measured at the end of TN4. Commercial pigs had lower FI when fed a high fiber diet compared to a regular diet (2.70 ± 0.08 vs. 2.96 ± 0.08 kg/d; P < 0.05, while no differences were found for BWG, RFI or FCE. HS reduced FI, BWG, and FCE, increased RFI, and resulted in leaner pigs that generate smaller carcasses at slaughter. In TN, commercial pigs grew faster than the low and high RFI pigs (1.22 ± 0.06 vs. 0.720 ± 0.05 and 0.657 ± 0.07; P < 0.001 but growth rates were not significantly different between the lines during HS. Growth rates for the low RFI and high RFI pigs were similar both during TN and during HS. Pigs of interest for genetic improvement are those that are able to maintain growth rates during HS. Our results show that response in growth to HS was repeatable over subsequent 4-d HS cycles, which suggests the potential for including this response in the breeding index. The best performing animals during HS are likely those that are not highly superior for growth in TN.

  2. The effect of repeated measurements and working memory on the most comfortable level in the ANL test.

    Science.gov (United States)

    Brännström, K Jonas; Olsen, Steen Østergaard; Holm, Lucas; Kastberg, Tobias; Ibertsson, Tina

    2014-11-01

    To study the effect of a large number of repetitions on the most comfortable level (MCL) when doing the acceptable noise level (ANL) test, and explore if MCL variability is related to central cognitive processes. Twelve MCL repetitions were measured within the ANL test using interleaved methodology during one session using a non-semantic version. Phonological (PWM) and visuospatial working memory (VSWM) was measured. Thirty-two normal-hearing adults. Repeated measures ANOVA, intraclass correlations, and the coefficient of repeatability (CR) were used to assess the repeatability. Repeated measures ANOVA and CR indicated poor agreement between the two first repetitions. After excluding the first repetition, analyses showed that the MCL in the ANL test is reliable. A negative association was found between PWM and MCL variability indicating that subjects with higher PWM show less variability. The findings suggest that, after excluding the first repetition, the MCL in the ANL test is reliable. A single repetition of the MCL in the ANL test should be avoided. If an interleaved methodology is used, a single ANL repetition should be added prior to the actual testing. The findings also suggest that MCL variability is associated to PWM but not VSWM.

  3. Comparative analysis of transcriptomic responses to repeated-dose exposure to 2-MCPD and 3-MCPD in rat kidney, liver and testis.

    Science.gov (United States)

    Buhrke, Thorsten; Schultrich, Katharina; Braeuning, Albert; Lampen, Alfonso

    2017-08-01

    3-Chloro-1,2-propanediol (3-MCPD) and its isomer 2-chloro-1,3-propanediol (2-MCPD) are heat-induced food contaminants present in oil- and fat-containing foodstuff. Kidney and testes are among the main target organs of 3-MCPD. Almost no data on 2-MCPD toxicity are available. Here, transcriptomic responses following repeated-dose exposure of rats to non-toxic doses of 10 mg/kg body weight per day 2-MCPD or 3-MCPD for 28 days were characterized by microarray analysis of kidney, liver, and testes. 3-MCPD exerted more pronounced effects than 2-MCPD in all organs. The limited overlap between the datasets indicates that 2-MCPD and 3-MCPD do not share the same molecular mechanisms of toxicity. By combining transcriptomic data with datasets on proteomic regulation by 3-MCPD, a comprehensive view on 3-MCPD-induced regulation of glucose utilization and oxidative stress response was developed. Bioinformatic analyses revealed that Nrf2 (nuclear factor (erythroid-derived 2)-like 2) signaling is likely to be involved in mediating the oxidative stress response to 3-MCPD. In summary, this study for the first time presents data on alterations in global gene expression by two important food contaminants, 2-MCPD and 3-MCPD. Data demonstrate profound differences between the effects of the two compounds and substantially broaden our knowledge on molecular details of 3-MCPD-induced disturbance of glucose utilization and redox balance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Effects of short-term repeated exposure to different flooring surfaces on the behavior and physiology of dairy cattle.

    Science.gov (United States)

    Schütz, K E; Cox, N R

    2014-05-01

    during the stand-off period. We observed no major effect of the repeated stand-off exposure. In summary, adding rubber matting onto concrete surfaces for stand-off purposes is beneficial for animal welfare. A well-managed wood chip surface offered the best welfare for dairy cows removed from pasture, and the findings of this study confirm that a concrete surface decreases the welfare of cows removed from pasture. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  5. Triage of Women with Low-Grade Cervical Lesions - HPV mRNA Testing versus Repeat Cytology

    Science.gov (United States)

    Sørbye, Sveinung Wergeland; Arbyn, Marc; Fismen, Silje; Gutteberg, Tore Jarl; Mortensen, Elin Synnøve

    2011-01-01

    Background In Norway, women with low-grade squamous intraepithelial lesions (LSIL) are followed up after six months in order to decide whether they should undergo further follow-up or be referred back to the screening interval of three years. A high specificity and positive predictive value (PPV) of the triage test is important to avoid unnecessary diagnostic and therapeutic procedures. Materials and Methods At the University Hospital of North Norway, repeat cytology and the HPV mRNA test PreTect HPV-Proofer, detecting E6/E7 mRNA from HPV types 16, 18, 31, 33 and 45, are used in triage of women with ASC-US and LSIL. In this study, women with LSIL cytology in the period 2005–2008 were included (n = 522). Two triage methods were evaluated in two separate groups: repeat cytology only (n = 225) and HPV mRNA testing in addition to repeat cytology (n = 297). Histologically confirmed cervical intraepithelial neoplasia of grade 2 or worse (CIN2+) was used as the study endpoint. Results Of 522 women with LSIL, 207 had biopsies and 125 of them had CIN2+. The sensitivity and specificity of repeat cytology (ASC-US or worse) were 85.7% (95% confidence interval (CI): 72.1, 92.2) and 54.4 % (95% CI: 46.9, 61.9), respectively. The sensitivity and specificity of the HPV mRNA test were 94.2% (95% CI: 88.7, 99.7) and 86.0% (95% CI: 81.5, 90.5), respectively. The PPV of repeat cytology was 38.4% (95% CI: 29.9, 46.9) compared to 67.0% (95% CI: 57.7, 76.4) of the HPV mRNA test. Conclusion HPV mRNA testing was more sensitive and specific than repeat cytology in triage of women with LSIL cytology. In addition, the HPV mRNA test showed higher PPV. These data indicate that the HPV mRNA test is a better triage test for women with LSIL than repeat cytology. PMID:21918682

  6. Positive patch test reactions to oxidized limonene: exposure and relevance.

    Science.gov (United States)

    Bråred Christensson, Johanna; Andersen, Klaus E; Bruze, Magnus; Johansen, Jeanne D; Garcia-Bravo, Begoña; Gimenez Arnau, Ana; Goh, Chee-Leok; Nixon, Rosemary; White, Ian R

    2014-11-01

    R-Limonene is a common fragrance terpene found in domestic and industrial products. R-Limonene autoxidizes on air exposure, and the oxidation products can cause contact allergy. In a recent multicentre study, 5.2% (range 2.3-12.1%) of 2900 patients showed a positive patch test reaction to oxidized R-limonene. To study the exposure to limonene among consecutive dermatitis patients reacting to oxidized R-limonene in an international setting, and to assess the relevance of the exposure for the patients' dermatitis. Oxidized R-limonene 3.0% (containing limonene hydroperoxides at 0.33%) in petrolatum was tested in 2900 consecutive dermatitis patients in Australia, Denmark, the United Kingdom, Singapore, Spain, and Sweden. A questionnaire assessing exposure to limonene-containing products was completed. Overall, exposure to products containing limonene was found and assessed as being probably relevant for the patients' dermatitis in 36% of the limonene-allergic patients. In Barcelona and Copenhagen, > 70% of the patients were judged to have had an exposure to limonene assessed as relevant. Oxidized R-limonene is a common fragrance allergen, and limonene was frequently found in the labelling on the patients' products, and assessed as relevant for the patients' dermatitis. A large number of domestic and occupational sources for contact with R-limonene were identified. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. CAG repeat testing of androgen receptor polymorphism: is this necessary for the best clinical management of hypogonadism?

    Science.gov (United States)

    Francomano, Davide; Greco, Emanuela A; Lenzi, Andrea; Aversa, Antonio

    2013-10-01

    It is controversial whether or not testing the length of the androgen receptor polymorphism in clinical practice is useful for correct diagnosis and treatment of hypogonadism. To describe the molecular and clinical implications of testing the length of the androgen receptor polymorphism for treatment of hypogonadism in both male and female subjects. A systematic Medline search was conducted using several terms related to and including the terms "androgen receptor," "CAG-repeat polymorphism," "male hypogonadism," "female hypogonadism," and "neurodegenerative disease." Clinical evidence that demonstrates the importance of CAG repeat number investigation in male and female hypogonadism. A thorough review of the clinical utility of CAG repeat polymorphism investigation in men and women with hypogonadism is presented. The role of AR CAG repeat number investigation in hypogonadism (male and female) is not yet established in the clinical practice. In both sexes, a role during clinical management of hormonal replacement therapies may be hypothesized, but the CAG repeat number's relationship with the presence or absence of hypogonadal symptoms remains unclear. Pharmacogenomic investigations of the AR polymorphism may be a future option to tailor testosterone titration individually and to better identify subjects as potentially more or less responsive to treatments; also, investigation may be important to individually predict beneficial and side effects in special subpopulations, specifically, obese men and postmenopausal women. © 2013 International Society for Sexual Medicine.

  8. Higher Drop in Speed during a Repeated Sprint Test in Soccer Players Reporting Former Hamstring Strain Injury

    Science.gov (United States)

    Røksund, Ola D.; Kristoffersen, Morten; Bogen, Bård E.; Wisnes, Alexander; Engeseth, Merete S.; Nilsen, Ann-Kristin; Iversen, Vegard V.; Mæland, Silje; Gundersen, Hilde

    2017-01-01

    Aim: Hamstring strain injury is common in soccer. The aim of this study was to evaluate the physical capacity of players who have and have not suffered from hamstring strain injury in a sample of semi-professional and professional Norwegian soccer players in order to evaluate characteristics and to identify possible indications of insufficient rehabilitation. Method: Seventy-five semi-professional and professional soccer players (19 ± 3 years) playing at the second and third level in the Norwegian league participated in the study. All players answered a questionnaire, including one question about hamstring strain injury (yes/no) during the previous 2 years. They also performed a 40 m maximal sprint test, a repeated sprint test (8 × 20 m), a countermovement jump, a maximal oxygen consumption (VO2max) test, strength tests and flexibility tests. Independent sample t-tests were used to evaluate differences in the physical capacity of the players who had suffered from hamstring strain injury and those who had not. Mixed between-within subject's analyses of variance was used to compare changes in speed during the repeated sprint test between groups. Results: Players who reported hamstring strain injury during the previous two years (16%) had a significantly higher drop in speed (0.07 vs. 0.02 s, p = 0.007) during the repeated sprint test, compared to players reporting no previous hamstring strain injury. In addition, there was a significant interaction (groups × time) (F = 3.22, p = 0.002), showing that speed in the two groups changed differently during the repeated sprint test. There were no significant differences in relations to age, weight, height, body fat, linear speed, countermovement jump height, leg strength, VO2max, or hamstring flexibility between the groups. Conclusion: Soccer players who reported hamstring strain injury during the previous 2 years showed significant higher drop in speed during the repeated sprint test compared to players with no hamstring

  9. Test-retest repeatability of child's respiratory symptoms and perceived indoor air quality - comparing self- and parent-administered questionnaires.

    Science.gov (United States)

    Lampi, Jussi; Ung-Lanki, Sari; Santalahti, Päivi; Pekkanen, Juha

    2018-02-09

    Questionnaires can be used to assess perceived indoor air quality and symptoms in schools. Questionnaires for primary school aged children have traditionally been parent-administered, but self-administered questionnaires would be easier to administer and may yield as good, if not better, information. Our aim was to compare the repeatability of self- and parent-administered indoor air questionnaires designed for primary school aged pupils. Indoor air questionnaire with questions on child's symptoms and perceived indoor air quality in schools was sent to parents of pupils aged 7-12 years in two schools and again after two weeks. Slightly modified version of the questionnaire was administered to pupils aged 9-12 years in another two schools and repeated after a week. 351 (52%) parents and 319 pupils (86%) answered both the first and the second questionnaire. Test-retest repeatability was assessed with intra-class correlation (ICC) and Cohen's kappa coefficients (k). Test-retest repeatability was generally between 0.4-0.7 (ICC; k) in both self- and parent-administered questionnaire. In majority of the questions on symptoms and perceived indoor air quality test-retest repeatability was at the same level or slightly better in self-administered compared to parent-administered questionnaire. Agreement of self- and parent administered questionnaires was generally indoor air quality. Children aged 9-12 years can give as, or even more, repeatable information about their respiratory symptoms and perceived indoor air quality than their parents. Therefore, it may be possible to use self-administered questionnaires in future studies also with children.

  10. Chronic repeated exposure to weather-related stimuli elicits few symptoms of chronic stress in captive molting and non-molting European starlings (Sturnus vulgaris).

    Science.gov (United States)

    de Bruijn, Robert; Reed, J Michael; Romero, L Michael

    2017-10-01

    Repeated exposure to acute stressors causes dramatic changes in an animal's stress physiology and the cumulative effects are often called chronic stress. Recently we showed that short-term exposure to weather-related stimuli, such as temperature change, artificial precipitation, and food restriction, cause acute responses in captive European starlings (Sturnus vulgaris). Here, we examined the effect of repeated exposure to weather-related stressors on heart rate and corticosterone (CORT) of captive non-molting and molting European starlings. Four times every day for 3 weeks, birds were exposed to either 30 min of a subtle (3°C) decrease in temperature, a short bout of simulated rain, or 2 hr of food removal. The order and time of presentation were randomly assigned on each day. We found no differences in heart rate or heart rate variability. Furthermore, there were no changes in baseline CORT levels, CORT negative feedback efficacy, or maximal adrenal capacity. Mass increased across the experimental period only in molting birds. CORT responses to restraint were decreased in both groups following treatment, suggesting the birds had downregulated their responses to acute stress. Molting birds showed evidence of suppression of the HPA axis compared with non-molting birds, which is consistent with previous research. Overall, our data show that repeated exposure to weather-related stressors does not elicit most of the symptoms normally associated with chronic stress. © 2018 Wiley Periodicals, Inc.

  11. Repeated exposure to media messages encouraging parent-child communication about sex: differential trajectories for mothers and fathers.

    Science.gov (United States)

    Blitstein, Jonathan L; Evans, W Douglas; Davis, Kevin C; Kamyab, Kian

    2012-01-01

    To examine changes in parent-child communication related to sexual behavior after exposure to public health messages. Randomized, controlled trial that was part of precampaign message testing. Exposure occurred online or through DVDs mailed to participants and viewed on their personal computers. Data collection occurred via a secure Web site. Participants included parents (n  =  1969) living with a child age 10 to 14 years drawn from a nationally representative sample of U.S. households. Treatment participants were exposed to video, audio, and print advertisements that promoted the benefits of speaking to their children early and often about delaying initiation of sexual activity; messages also directed parents to an informational Web site. The dependent variable assessed frequency of parent-child communication related to sexual behavior. The primary independent variable was treatment assignment. Longitudinal growth modeling that included five waves of data. The trajectory of growth over time differed between fathers in the treatment group and fathers in the control group (F[1, 2357]  =  4.15; p groups. This study demonstrates that father-child and mother-child communication patterns differ over time in response to public health messages. Findings have implication for researchers developing health marketing campaigns.

  12. The Dark Side of Testing Memory: Repeated Retrieval Can Enhance Eyewitness Suggestibility

    Science.gov (United States)

    Chan, Jason C. K.; LaPaglia, Jessica A.

    2011-01-01

    Eyewitnesses typically recount their experiences many times before trial. Such repeated retrieval can enhance memory retention of the witnessed event. However, recent studies (e.g., Chan, Thomas, & Bulevich, 2009) have found that initial retrieval can exacerbate eyewitness suggestibility to later misleading information--a finding termed…

  13. Cross-trimester repeated measures testing for Down's syndrome screening: an assessment.

    LENUS (Irish Health Repository)

    Wright, D

    2010-07-01

    To provide estimates and confidence intervals for the performance (detection and false-positive rates) of screening for Down\\'s syndrome using repeated measures of biochemical markers from first and second trimester maternal serum samples taken from the same woman.

  14. Repeated Exposure to the “Spice” Cannabinoid JWH-018 Induces Tolerance and Enhances Responsiveness to 5-HT1A Receptor Stimulation in Male Rats

    Directory of Open Access Journals (Sweden)

    Joshua S. Elmore

    2018-02-01

    Full Text Available Naphthalen-1-yl-(1-pentylindol-3-ylmethanone (JWH-018 is a synthetic compound found in psychoactive “spice” products that activates cannabinoid receptors. Preclinical evidence suggests that exposure to synthetic cannabinoids increases 5-HT2A/2C receptor function in the brain, an effect which might contribute to psychotic symptoms. Here, we hypothesized that repeated exposures to JWH-018 would enhance behavioral responsiveness to the 5-HT2A/2C receptor agonist DOI. Male Sprague-Dawley rats fitted with subcutaneously (sc temperature transponders received daily injections of JWH-018 (1.0 mg/kg, sc or its vehicle for seven consecutive days. Body temperature and catalepsy scores were determined at 1, 2, and 4 h post-injection each day. At 1 and 7 days after the final repeated treatment, rats received a challenge injection of either DOI (0.1 mg/kg, sc or the 5-HT1A receptor agonist 8-OH-DPAT (0.3 mg/kg, sc, then temperature and behavioral responses were assessed. Behaviors induced by DOI included wet dog shakes and back muscle contractions (i.e., skin jerks, while behaviors induced by 8-OH-DPAT included ambulation, forepaw treading, and flat body posture. On the first day of repeated treatment, JWH-018 produced robust hypothermia and catalepsy which lasted up to 4 h, and these effects were significantly blunted by day 7 of treatment. Repeated exposure to JWH-018 did not affect behaviors induced by DOI, but behavioral and hypothermic responses induced by 8-OH-DPAT were significantly augmented 1 day after cessation of JWH-018 treatment. Collectively, our findings show that repeated treatment with JWH-018 produces tolerance to its hypothermic and cataleptic effects, which is accompanied by transient enhancement of 5-HT1A receptor sensitivity in vivo.

  15. An Audit of Repeat Testing at an Academic Medical Center: Consistency of Order Patterns With Recommendations and Potential Cost Savings.

    Science.gov (United States)

    Hueth, Kyle D; Jackson, Brian R; Schmidt, Robert L

    2018-05-31

    To evaluate the prevalence of potentially unnecessary repeat testing (PURT) and the associated economic burden for an inpatient population at a large academic medical facility. We evaluated all inpatient test orders during 2016 for PURT by comparing the intertest times to published recommendations. Potential cost savings were estimated using the Centers for Medicare & Medicaid Services maximum allowable reimbursement rate. We evaluated result positivity as a determinant of PURT through logistic regression. Of the evaluated 4,242 repeated target tests, 1,849 (44%) were identified as PURT, representing an estimated cost-savings opportunity of $37,376. Collectively, the association of result positivity and PURT was statistically significant (relative risk, 1.2; 95% confidence interval, 1.1-1.3; P < .001). PURT contributes to unnecessary health care costs. We found that a small percentage of providers account for the majority of PURT, and PURT is positively associated with result positivity.

  16. Repeated exposure to high-frequency spanking and child externalizing behavior across the first decade: a moderating role for cumulative risk.

    Science.gov (United States)

    MacKenzie, Michael J; Nicklas, Eric; Brooks-Gunn, Jeanne; Waldfogel, Jane

    2014-12-01

    This study used the Fragile Families and Child Well-Being Study to examine the effects of repeated exposure to harsh parenting on child externalizing behavior across the first decade of life, and a moderating role for cumulative ecological risk. Maternal report of harsh parenting, defined as high frequency spanking, was assessed at age 1, 3, 5, and 9, along with child externalizing at age 9 (N=2,768). Controlling for gender, race, maternal nativity, and city of residence, we found a cumulative risk index to significantly moderate the effects of repeated harsh parenting on child behavior, with the effects of repeated high-frequency spanking being amplified for those experiencing greater levels of cumulative risk. Harsh parenting, in the form of high frequency spanking, remains a too common experience for children, and results demonstrate that the effects of repeated exposure to harsh parenting across the first decade are amplified for those children already facing the most burden. Copyright © 2014. Published by Elsevier Ltd.

  17. Repeated rat-forced swim test: reducing the number of animals to evaluate gradual effects of antidepressants.

    Science.gov (United States)

    Mezadri, T J; Batista, G M; Portes, A C; Marino-Neto, J; Lino-de-Oliveira, C

    2011-02-15

    The forced swim test (FST) is a pre-clinical test to short and long term treatment with antidepressant drugs (ADT), which requires between-subject designs. Herein a modified protocol of the FST using within-subject design (repeated rat-FST) was evaluated. Male Wistar rats were submitted to 15 min of swimming (Day 1: pretest) followed by three subsequent 5 min-swimming tests one week apart (Day 2: test, Day 7: retest 1, Day 14: retest 2). To determine the temporal and factorial characteristics of the variables scored in the repeated rat-FST, the protocol was carried out in untreated animals (E1). To validate the method, daily injections of Fluoxetine (FLX, 2.5mg/kg, i.p.) or saline were given over a 2-week period (E2). Tests and retests have been videotaped for further register of the latency, frequency and duration of behaviors. Over retesting the latency to immobility decreased whereas duration of immobility tended to increase. Factorial analysis revealed that the test, the retest 1 as well as the retest 2 have variables suitable to detection of antidepressant-like effects of ADT. Compared to saline, FLX chronically administrated reduced duration of immobility whereas increased duration of swimming in retest 2. The data suggest that repeated rat-FST detected the gradual increase in the efficacy of low doses of FLX over time. Therefore, repeated rat-FST seemed suitable to detect short and long term effects of selective serotonin reuptake inhibitors, or other ADT, thus reducing the number of animals used in the screenings of this type of compounds. © 2010 Elsevier B.V. All rights reserved.

  18. Reduction and technical simplification of testing protocol for walking based on repeatability analyses: An Interreg IVa pilot study

    Directory of Open Access Journals (Sweden)

    Nejc Sarabon

    2010-12-01

    Full Text Available The aim of this study was to define the most appropriate gait measurement protocols to be used in our future studies in the Mobility in Ageing project. A group of young healthy volunteers took part in the study. Each subject carried out a 10-metre walking test at five different speeds (preferred, very slow, very fast, slow, and fast. Each walking speed was repeated three times, making a total of 15 trials which were carried out in a random order. Each trial was simultaneously analysed by three observers using three different technical approaches: a stop watch, photo cells and electronic kinematic dress. In analysing the repeatability of the trials, the results showed that of the five self-selected walking speeds, three of them (preferred, very fast, and very slow had a significantly higher repeatability of the average walking velocity, step length and cadence than the other two speeds. Additionally, the data showed that one of the three technical methods for gait assessment has better metric characteristics than the other two. In conclusion, based on repeatability, technical and organizational simplification, this study helped us to successfully define a simple and reliable walking test to be used in the main study of the project.

  19. Ultra-Accelerated Natural Sunlight Exposure Testing Facilities

    Science.gov (United States)

    Lewandowski, Allan A.; Jorgensen, Gary J.

    2004-11-23

    A multi-faceted concentrator apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: facets that receive incident natural sunlight, transmits VIS/NIR and reflects UV/VIS onto a secondary reflector that delivers a uniform flux of UV/VIS onto a sample exposure plane located near a center of a facet array in a chamber that provide concurrent levels of temperature and/or relative humidity at high levels of up to 100.times. of natural sunlight that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth representative weathering of sample materials.

  20. Human epidermal growth factor receptor 2 testing in invasive breast cancer: should histological grade, type and oestrogen receptor status influence the decision to repeat testing?

    Science.gov (United States)

    Rakha, Emad A; Pigera, Marian; Shin, Sandra J; D'Alfonso, Timothy; Ellis, Ian O; Lee, Andrew H S

    2016-07-01

    The recent American Society of Clinical Oncology/College of American Pathologists guidelines for human epidermal growth factor receptor 2 (HER2) testing in breast cancer recommend repeat testing based on tumour grade, tumour type, and hormone receptor status. The aim of this study was to test the value of these criteria. HER2 status was concordant in the core biopsies and excision specimens in 392 of 400 invasive carcinomas. The major reasons for discordance were amplification around the cut-off for positivity and tumour heterogeneity. Of 116 grade 3 carcinomas that were HER2-negative in the core biopsy, four were HER2-positive in the excision specimen. Three of these four either showed borderline negative amplification in the core biopsy or were heterogeneous. None of the 55 grade 1 carcinomas were HER2-positive. Review of repeat testing of HER2 in routine practice suggested that it may also be of value for multifocal tumours and if recommended by the person assessing the in-situ hybridization. Mandatory repeat HER2 testing of grade 3 HER2-negative carcinomas is not appropriate. This is particularly true if repeat testing is performed after borderline negative amplification in the core biopsy or in HER2-negative heterogeneous carcinomas. © 2015 John Wiley & Sons Ltd.

  1. Effect of e-Learning and Repeated Performance Feedback on Spirometry Test Quality in Family Practice: A Cluster Trial

    Science.gov (United States)

    Schermer, Tjard R.; Akkermans, Reinier P.; Crockett, Alan J.; van Montfort, Marian; Grootens-Stekelenburg, Joke; Stout, Jim W.; Pieters, Willem

    2011-01-01

    PURPOSE Spirometry has become an indispensable tool in primary care to exclude, diagnose, and monitor chronic respiratory conditions, but the quality of spirometry tests in family practices is a reason for concern. Aim of this study was to investigate whether a combination of e-learning and bimonthly performance feedback would improve spirometry test quality in family practices in the course of 1 year. METHODS Our study was a cluster trial with 19 family practices allocated to intervention or control conditions through minimization. Intervention consisted of e-learning and bimonthly feedback reports to practice nurses. Control practices received only the joint baseline workshop. Spirometry quality was assessed by independent lung function technicians. Two outcomes were defined, with the difference between rates of tests with 2 acceptable and repeatable blows being the primary outcome and the difference between rates of tests with 2 acceptable blows being the secondary outcome. We used multilevel logistic regression analysis to calculate odds ratios (ORs) for an adequate test in intervention group practices. RESULTS We analyzed 1,135 tests. Rate of adequate tests was 33% in intervention and 30% in control group practices (OR = 1.3; P=.605). Adequacy of tests did not differ between groups but tended to increase with time: OR = 2.2 (P = .057) after 3 and OR = 2.0 (P = .086) in intervention group practices after 4 feedback reports. When ignoring test repeatability, these differences between the groups were slightly more pronounced: OR = 2.4 (P = .033) after 3 and OR=2.2 (P = .051) after 4 feedback reports. CONCLUSIONS In the course of 1 year, we observed a small and late effect of e-learning and repeated feedback on the quality of spirometry as performed by family practice nurses. This intervention does not seem to compensate the lack of rigorous training and experience in performing spirometry tests in most practices. PMID:21747104

  2. Effect of e-learning and repeated performance feedback on spirometry test quality in family practice: a cluster trial.

    Science.gov (United States)

    Schermer, Tjard R; Akkermans, Reinier P; Crockett, Alan J; van Montfort, Marian; Grootens-Stekelenburg, Joke; Stout, Jim W; Pieters, Willem

    2011-01-01

    Spirometry has become an indispensable tool in primary care to exclude, diagnose, and monitor chronic respiratory conditions, but the quality of spirometry tests in family practices is a reason for concern. Aim of this study was to investigate whether a combination of e-learning and bimonthly performance feedback would improve spirometry test quality in family practices in the course of 1 year. Our study was a cluster trial with 19 family practices allocated to intervention or control conditions through minimization. Intervention consisted of e-learning and bimonthly feedback reports to practice nurses. Control practices received only the joint baseline workshop. Spirometry quality was assessed by independent lung function technicians. Two outcomes were defined, with the difference between rates of tests with 2 acceptable and repeatable blows being the primary outcome and the difference between rates of tests with 2 acceptable blows being the secondary outcome. We used multilevel logistic regression analysis to calculate odds ratios (ORs) for an adequate test in intervention group practices. We analyzed 1,135 tests. Rate of adequate tests was 33% in intervention and 30% in control group practices (OR = 1.3; P=.605). Adequacy of tests did not differ between groups but tended to increase with time: OR = 2.2 (P = .057) after 3 and OR = 2.0 (P = .086) in intervention group practices after 4 feedback reports. When ignoring test repeatability, these differences between the groups were slightly more pronounced: OR = 2.4 (P = .033) after 3 and OR=2.2 (P = .051) after 4 feedback reports. In the course of 1 year, we observed a small and late effect of e-learning and repeated feedback on the quality of spirometry as performed by family practice nurses. This intervention does not seem to compensate the lack of rigorous training and experience in performing spirometry tests in most practices.

  3. Systems for animal exposure in full-scale fire tests

    Science.gov (United States)

    Hilado, C. J.; Cumming, H. J.; Kourtides, D. A.; Parker, J. A.

    1977-01-01

    Two systems for exposing animals in full-scale fire tests are described. Both systems involve the simultaneous exposure of two animal species, mice and rats, in modular units; determination of mortality, morbidity, and behavioral response; and analysis of the blood for carboxyhemoglobin. The systems described represent two of many possible options for obtaining bioassay data from full-scale fire tests. In situations where the temperatures to which the test animals are exposed can not be controlled, analytical techniques may be more appropriate than bioassay techniques.

  4. Deployment Repeatability

    Science.gov (United States)

    2016-08-31

    large cohort of trials to spot unusual cases. However, deployment repeatability is inherently a nonlinear phenomenon, which makes modeling difficult...and GEMS tip position were both tracked during ground testing by a laser target tracking system. Earlier SAILMAST testing in 2005 [8] used...recalls the strategy used by SRTM, where a constellation of lights was installed at the tip of the boom and a modified star tracker was used to track tip

  5. Alternative Testing Methods for Predicting Health Risk from Environmental Exposures

    Directory of Open Access Journals (Sweden)

    Annamaria Colacci

    2014-08-01

    Full Text Available Alternative methods to animal testing are considered as promising tools to support the prediction of toxicological risks from environmental exposure. Among the alternative testing methods, the cell transformation assay (CTA appears to be one of the most appropriate approaches to predict the carcinogenic properties of single chemicals, complex mixtures and environmental pollutants. The BALB/c 3T3 CTA shows a good degree of concordance with the in vivo rodent carcinogenesis tests. Whole-genome transcriptomic profiling is performed to identify genes that are transcriptionally regulated by different kinds of exposures. Its use in cell models representative of target organs may help in understanding the mode of action and predicting the risk for human health. Aiming at associating the environmental exposure to health-adverse outcomes, we used an integrated approach including the 3T3 CTA and transcriptomics on target cells, in order to evaluate the effects of airborne particulate matter (PM on toxicological complex endpoints. Organic extracts obtained from PM2.5 and PM1 samples were evaluated in the 3T3 CTA in order to identify effects possibly associated with different aerodynamic diameters or airborne chemical components. The effects of the PM2.5 extracts on human health were assessed by using whole-genome 44 K oligo-microarray slides. Statistical analysis by GeneSpring GX identified genes whose expression was modulated in response to the cell treatment. Then, modulated genes were associated with pathways, biological processes and diseases through an extensive biological analysis. Data derived from in vitro methods and omics techniques could be valuable for monitoring the exposure to toxicants, understanding the modes of action via exposure-associated gene expression patterns and to highlight the role of genes in key events related to adversity.

  6. A multiple objective test assembly approach for exposure control problems in Computerized Adaptive Testing

    Directory of Open Access Journals (Sweden)

    Theo J.H.M. Eggen

    2010-01-01

    Full Text Available Overexposure and underexposure of items in the bank are serious problems in operational computerized adaptive testing (CAT systems. These exposure problems might result in item compromise, or point at a waste of investments. The exposure control problem can be viewed as a test assembly problem with multiple objectives. Information in the test has to be maximized, item compromise has to be minimized, and pool usage has to be optimized. In this paper, a multiple objectives method is developed to deal with both types of exposure problems. In this method, exposure control parameters based on observed exposure rates are implemented as weights for the information in the item selection procedure. The method does not need time consuming simulation studies, and it can be implemented conditional on ability level. The method is compared with Sympson Hetter method for exposure control, with the Progressive method and with alphastratified testing. The results show that the method is successful in dealing with both kinds of exposure problems.

  7. Effects of Single and Repeated Exposure to a 50-Hz 2-mT Electromagnetic Field on Primary Cultured Hippocampal Neurons.

    Science.gov (United States)

    Zeng, Ying; Shen, Yunyun; Hong, Ling; Chen, Yanfeng; Shi, Xiaofang; Zeng, Qunli; Yu, Peilin

    2017-06-01

    The prevalence of domestic and industrial electrical appliances has raised concerns about the health risk of extremely low-frequency magnetic fields (ELF-MFs). At present, the effects of ELF-MFs on the central nervous system are still highly controversial, and few studies have investigated its effects on cultured neurons. Here, we evaluated the biological effects of different patterns of ELF-MF exposure on primary cultured hippocampal neurons in terms of viability, apoptosis, genomic instability, and oxidative stress. The results showed that repeated exposure to 50-Hz 2-mT ELF-MF for 8 h per day after different times in culture decreased the viability and increased the production of intracellular reactive oxidative species in hippocampal neurons. The mechanism was potentially related to the up-regulation of Nox2 expression. Moreover, none of the repeated exposure patterns had significant effects on DNA damage, apoptosis, or autophagy, which suggested that ELF-MF exposure has no severe biological consequences in cultured hippocampal neurons.

  8. Effects of single and repeated exposure to biocidal active substances on the barrier function of the skin in vitro

    NARCIS (Netherlands)

    Buist, H.E.; Sandt, J.J.M. van de; Burgsteden, J.A. van; Heer, C. de

    2005-01-01

    The dermal route of exposure is important in worker exposure to biocidal products. Many biocidal active substances which are used on a daily basis may decrease the barrier function of the skin to a larger extent than current risk assessment practice addresses, due to possible skin effects of

  9. Effect of exposure to evening light on sleep initiation in the elderly: a longitudinal analysis for repeated measurements in home settings.

    Science.gov (United States)

    Obayashi, Kenji; Saeki, Keigo; Iwamoto, Junko; Okamoto, Nozomi; Tomioka, Kimiko; Nezu, Satoko; Ikada, Yoshito; Kurumatani, Norio

    2014-05-01

    Epidemiologic data have demonstrated associations of sleep-onset insomnia with a variety of diseases, including depression, dementia, diabetes and cardiovascular diseases. Sleep initiation is controlled by the suprachiasmatic nucleus of the hypothalamus and endogenous melatonin, both of which are influenced by environmental light. Exposure to evening light is hypothesized to cause circadian phase delay and melatonin suppression before bedtime, resulting in circadian misalignment and sleep-onset insomnia; however, whether exposure to evening light disturbs sleep initiation in home settings remains unclear. In this longitudinal analysis of 192 elderly individuals (mean age: 69.9 years), we measured evening light exposure and sleep-onset latency for 4 days using a wrist actigraph incorporating a light meter and an accelerometer. Mixed-effect linear regression analysis for repeated measurements was used to evaluate the effect of evening light exposure on subsequent sleep-onset latency. The median intensity of evening light exposure and the median sleep-onset latency were 27.3 lux (interquartile range, 17.9-43.4) and 17 min (interquartile range, 7-33), respectively. Univariate models showed significant associations between sleep-onset latency and age, gender, daytime physical activity, in-bed time, day length and average intensity of evening and nighttime light exposures. In a multivariate model, log-transformed average intensity of evening light exposure was significantly associated with log-transformed sleep-onset latency independent of the former potential confounding factors (regression coefficient, 0.133; 95% CI, 0.020-0.247; p = 0.021). Day length and nighttime light exposure were also significantly associated with log-transformed sleep-onset latency (p = 0.001 and p < 0.001, respectively). In conclusion, exposure to evening light in home setting prolongs subsequent sleep-onset latency in the elderly.

  10. To describe and control exposure in nanoecotoxicology tests

    DEFF Research Database (Denmark)

    Baun, Anders

    are fulfilling the purpose they originally were intended for (ranking and classification). The validity of extrapolations made from these data (e.g. predicted no-effect concentrations for environmental risk assessments) is therefore further questionable. Based on own experiences these fundamental problems......There is an urgent need for reliable and reproducible results of ecotoxicological experiments in order to identify, rank, and classify the environmental hazards of nanomaterials. Standardized methods and guideline tests traditionally used for chemicals are today recommended for the testing...... of nanomaterials. While the database of results from these tests is rapidly expanding, problems with controlling the exposure are often reported, e.g. due to the particle behavior in the test media used. Problems encountered include uncontrollable aggregation, agglomeration, sedimentation, or dissolution...

  11. IsTeen Court effective for repeat offenders? A test of the restorative justice approach.

    Science.gov (United States)

    Forgays, Deborah Kirby; DeMilio, Lisa

    2005-02-01

    Teen Courts are an effective judicial alternative for many youth offenders. The majority of youth courts deal solely with first-time offenders. However, repeat offenders are at a greater risk for future crime. Is Teen Court effective with more experienced offenders? In this study, the authors examine the outcomes of 26 Whatcom County Teen Court offenders with at least one prior conviction. The sentence completion rate was higher and the recidivism was lower for the Teen Court offenders when compared with a sample of first-time Court Diversion offenders. This objective evidence of program success is augmented by an offender's perspective on his or her court experience. These perspectives as well as the continued voluntary involvement with Teen Court are discussed in relation to empowerment theory.

  12. Effect of haemolysis and repeated freeze-thawing cycles on wild boar serum antibody testing by ELISA

    Directory of Open Access Journals (Sweden)

    Boadella Mariana

    2011-11-01

    Full Text Available Abstract Background Monitoring wildlife diseases is needed to identify changes in disease occurrence. Wildlife blood samples are valuable for this purpose but are often gathered haemolysed. To maximise information, sera often go through repeated analysis and freeze-thaw cycles. Herein, we used samples of clean and haemolysed Eurasian wild boar (Sus scrofa serum stored at -20°C and thawed up to five times to study the effects of both treatments on the outcome of a commercial ELISA test for the detection of antibodies against Suid Herpesvirus 1 (ADV. Results The estimated prevalence of antibodies against ADV was 50-53% for clean and haemolysed sera. Hence, haemolysis did not reduce the mean observed serum antibody prevalence. However, 10 samples changed their classification after repeated freeze-thawing. This included 3 (15% of the clean sera and 7 (41% of the haemolysed sera. Conclusions We recommend (1 establishing more restrictive cut-off values when testing wildlife sera, (2 recording serum quality prior to sample banking, (3 recording the number of freezing-thawing cycles and (4 store sera in various aliquots to reduce repeated usage. For instance, sera with more than 3 freeze-thaw cycles and a haemolysis of over 3 on a scale of 4 should better be discarded for serum antibody monitoring. Even clean (almost not haemolysed sera should not go through more than 5 freeze-thaw cycles.

  13. Radiation exposure of inhabitants around Semipalatinsk nuclear weapon test site

    International Nuclear Information System (INIS)

    Takada, Jun; Hoshi, Masaharu

    1997-01-01

    This paper described and reviewed the data reported by Russia and Kazakhstan and authors' studies on the exposed doses as follows. History of nuclear explosion tests in Semipalatinsk: From 1949 to 1989 in old Russia, 459 explosion tests involving 26 on the ground, 87 in the air and 346 in underground were performed, of which TNT equivalence was 0.6 Mt, 6 Mt and 11 Mt, respectively. A mystery in the reports of radiation doses by Russia and Kazakhstan. Present status of the regions after the end of nuclear weapon tests: Environment radiation doses in μSv/h in following regions were 0.06 in Mostik, 0.1 in Dolon and Semipalatinsk, 0.07 in Izvyestka and Znamenka, 0.08 in Tchagan and 21 in Atomic Lake. Evaluation of external exposure dose of the living regions with thermoluminescence method: External exposure dose was estimated to be about 90 cGy in a certain village and 40 cGy in Semipalatinsk which being 150 km far from the test site. (K.H.)

  14. The effects of chronic cadmium exposure on repeat swimming performance and anaerobic metabolism in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis)

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, Jessie L.; McGeer, James C., E-mail: jmcgeer@wlu.ca

    2016-04-15

    Highlights: • Exposure to 18 nM waterborne Cd induced plasma Ca loss that recovered by day 30 for lake whitefish but not brown trout. • Ucrit measured after an initial swim to 85% of Ucrit and a 30 min rest period was reduced in 18 nM Cd exposed fish compared to controls. • Swimming to 85% of Ucrit resulted in decreased muscle glycogen and increased lactate that was not recovered in the 30 min recovery period. • Second swim impairment is not related to metabolic processes in white muscle. - Abstract: This study investigates the effect of chronic Cd exposure on the ability to perform repeat swim challenges in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis). Fish were exposed to waterborne Cd (18 nM) in moderately hard water (120 mg L{sup −1} CaCO{sub 3}) for 30 days. This level of exposure has been shown to cause sublethal physiological disruption and acclimation responses but no impairment of sustained swimming capacity (U{sub crit}) in single swim challenges. Swim trials were done over the course of the exposure and each one consisted of an initial swim to 85% of the U{sub crit} of control fish, a 30 min recovery period and finally a second swim challenge to determine U{sub crit}. Plasma and tissue samples were collected before and after each of the swim periods. As expected from previous studies, Cd exposure resulted in significant accumulation of Cd in gills, liver and kidney but not in white muscle. Exposure also induced a loss of plasma Ca followed by subsequent recovery (in lake whitefish but not brown trout) with few mortalities (100% survival for lake whitefish and 93% for brown trout). Both control and exposed fish swam to 85% of the single swim U{sub crit} and no differences in performance were seen. The Ucrit of unexposed controls in the second swim challenges were not different from the single swim Ucrit. However, second swim performance was significantly reduced in Cd exposed fish, particularly after a week of exposure

  15. The effects of chronic cadmium exposure on repeat swimming performance and anaerobic metabolism in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis)

    International Nuclear Information System (INIS)

    Cunningham, Jessie L.; McGeer, James C.

    2016-01-01

    Highlights: • Exposure to 18 nM waterborne Cd induced plasma Ca loss that recovered by day 30 for lake whitefish but not brown trout. • Ucrit measured after an initial swim to 85% of Ucrit and a 30 min rest period was reduced in 18 nM Cd exposed fish compared to controls. • Swimming to 85% of Ucrit resulted in decreased muscle glycogen and increased lactate that was not recovered in the 30 min recovery period. • Second swim impairment is not related to metabolic processes in white muscle. - Abstract: This study investigates the effect of chronic Cd exposure on the ability to perform repeat swim challenges in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis). Fish were exposed to waterborne Cd (18 nM) in moderately hard water (120 mg L"−"1 CaCO_3) for 30 days. This level of exposure has been shown to cause sublethal physiological disruption and acclimation responses but no impairment of sustained swimming capacity (U_c_r_i_t) in single swim challenges. Swim trials were done over the course of the exposure and each one consisted of an initial swim to 85% of the U_c_r_i_t of control fish, a 30 min recovery period and finally a second swim challenge to determine U_c_r_i_t. Plasma and tissue samples were collected before and after each of the swim periods. As expected from previous studies, Cd exposure resulted in significant accumulation of Cd in gills, liver and kidney but not in white muscle. Exposure also induced a loss of plasma Ca followed by subsequent recovery (in lake whitefish but not brown trout) with few mortalities (100% survival for lake whitefish and 93% for brown trout). Both control and exposed fish swam to 85% of the single swim U_c_r_i_t and no differences in performance were seen. The Ucrit of unexposed controls in the second swim challenges were not different from the single swim Ucrit. However, second swim performance was significantly reduced in Cd exposed fish, particularly after a week of exposure where 31% and 38

  16. Attentional and visual demands for sprint performance in non-fatigued and fatigued conditions: reliability of a repeated sprint test

    Directory of Open Access Journals (Sweden)

    Diercks Ron L

    2010-05-01

    Full Text Available Abstract Background Physical performance measures are widely used to assess physical function, providing information about physiological and biomechanical aspects of motor performance. However they do not provide insight into the attentional and visual demands for motor performance. A figure-of-eight sprint test was therefore developed to measure the attentional and visual demands for repeated-sprint performance. The aims of the study were: 1 to assess test-retest reliability of the figure-of-eight sprint test, and 2 to study the attentional and visual demands for sprint performance in a non-fatigued and fatigued condition. Methods Twenty-seven healthy athletes were included in the study. To determine test-retest reliability, a subgroup of 19 athletes performed the figure-of-eight sprint test twice. The figure-of-eight sprint test consisted of nine 30-second sprints. The sprint test consisted of three test parts: sprinting without any restriction, with an attention-demanding task, and with restricted vision. Increases in sprint times with the attention-demanding task or restricted vision are reflective of the attentional and visual demands for sprinting. Intraclass correlation coefficients (ICCs and mean difference between test and retest with 95% confidence limits (CL were used to assess test-retest reliability. Repeated-measures ANOVA were used for comparisons between the sprint times and fatigue measurements of the test parts in both a non-fatigued and fatigued condition. Results The figure-of-eight sprint test showed good test-retest reliability, with ICCs ranging from 0.75 to 0.94 (95% CL: 0.40-0.98. Zero lay within the 95% CL of the mean differences, indicating that no bias existed between sprint performance at test and retest. Sprint times during the test parts with attention-demanding task (P = 0.01 and restricted vision (P Conclusions High ICCs and the absence of systematic variation indicate good test-retest reliability of the figure

  17. Repeatability of a 3D multi-segment foot model during anterior and lateral step down tests.

    Science.gov (United States)

    Lucareli, Paulo Roberto Garcia; Contani, Luciane Beatriz Grohs; Lima, Bruna; Rabelo, Nayra Deise dos Anjos; Ferreira, Cintia Lopes; Lima, Fernanda Pulpio Silva; Correa, João Carlos Ferrari; Politti, Fabiano

    2016-01-01

    The aim of the present study was to analyse the reproducibility of the Oxford Foot Model (OFM) when used with healthy adults during two clinical tests, i.e., the Anterior Step Down Test (SDA) and the Lateral Step Down Test (SDL). Five healthy participants (one male and four females, 10 limbs in total) with a mean age of 22.2 (19-30) years were assessed in four sessions of tests conducted at intervals of one week. Two independent examiners performed two of the sessions of each of the tests. For each session (intra-day), nine repetitions of each clinical test (SDA and SDL) were performed. After an interval of three hours, the data were collected again. The tests were conducted again after an interval of one week using the same experimental conditions. The intra- and inter-session repeatabilities of the ranges of motion of the feet were determined according to the standard error of measurement (SEM) for each examiner and for the differences between the examiners. The repeatabilities of the results were high for both of the conducted tests. The SEM results were as follows: 0.47-1.94° for the intra-examiner assessment (SDA), 0.55-2.01° for the inter-examiner comparison (SDA), 0.44-2.43° for the intra-examiner assessment (SDL), and 0.54-1.89° for the inter-examiner comparison (SDL). The OFM model was shown to be reproducible in terms of assessing the range of motion of healthy adults during functional tests (SDA and SDL). Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Short-term exposure to repeated chasing stress does not induce habituation in Senegalese sole, Solea senegalensis

    DEFF Research Database (Denmark)

    Conde-Sieira, Marta; Valente, Luisa M.P.; Hernandez-Perez, Juan

    2018-01-01

    Animals can habituate to certain repeated stressors and reduce the physiological response that such stressor evoked initially. Studies related to stress habituation in fish are scarce and the available data differ depending on the species and on the type, duration and severity of the stressor...... no significant changes in serotonergic activity. However, incremented serotonergic activity was detected in fish previously trained. Furthermore, dopaminergic activity decreased in diurnal trained and nocturnal trained groups with respect to ST/naïve fish. Crh expression in hypothalamus was higher in ST...... for the animals to habituate, indicating that repeated chasing within short periods should be avoided when manipulating fish in order to keep proper welfare conditions in this species....

  19. The effect of sensory-nutrient congruency on food intake after repeated exposure: do texture and/or energy density matter?

    Science.gov (United States)

    Hogenkamp, P S

    2014-09-01

    Sensory properties guide the amount that people eat. In particular, food texture plays an important role in a food's 'expected satiation', which in turn affects the food-related decision making process. One hypothesis is that incongruent pairing of a textural cue with a post-ingestive outcome compromises this process, leading to poor energy compensation. Several studies examined the effect of both energy density and sensory characteristics (i.e. increased creaminess and thickness) on expectations, subjective appetite and food intake. To add to this literature, a re-analysis of data assessed whether the effect of sensory-nutrient pairings on energy intake compensation persisted after repeated exposure to a food. In this cross-over design, 27 participants consumed two preloads with 'congruent' (low-energy/liquid; high-energy/semi-solid) and two preloads with 'incongruent' (low-energy/semi-solid; high-energy/liquid) texture-nutrient combinations for nine subsequent meals, during which ad libitum intake was measured. Intake at first exposure did not differ between the low-energy (280±150kcal) and high-energy preloads (292±183kcal) in the incongruent conditions. By contrast, it was greater after the low-energy (332±203kcal) than after the high-energy (236±132kcal) preload in the congruent conditions (energy∗incongruent/congruent, p=0.04). Post-exposure, this pattern changed: intake depended on the energy density of the preloads in all conditions, and was greater after low-energy preloads (day∗energy∗incongruent/congruent-interaction for breakfast: p=0.02). Thus, manipulating the sensory properties of a food influenced energy compensation and meal size, but only at initial exposure. Repeated exposure 'corrected' the initial lack of compensation observed in conditions with incongruent sensory-nutrient pairings. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Narrative exposure therapy for posttraumatic stress disorder associated with repeated interpersonal trauma in patients with severe mental illness: a mixed methods design

    Directory of Open Access Journals (Sweden)

    Maria W. Mauritz

    2016-09-01

    Full Text Available Background: In the Netherlands, most patients with severe mental illness (SMI receive flexible assertive community treatment (FACT provided by multidisciplinary community mental health teams. SMI patients with comorbid posttraumatic stress disorder (PTSD are sometimes offered evidence-based trauma-focused treatment like eye movement desensitization reprocessing or prolonged exposure. There is a large amount of evidence for the effectiveness of narrative exposure therapy (NET within various vulnerable patient groups with repeated interpersonal trauma. Some FACT-teams provide NET for patients with comorbid PTSD, which is promising, but has not been specifically studied in SMI patients. Objectives: The primary aim is to evaluate NET in SMI patients with comorbid PTSD associated with repeated interpersonal trauma to get insight into whether (1 PTSD and dissociative symptoms changes and (2 changes occur in the present SMI symptoms, care needs, quality of life, global functioning, and care consumption. The second aim is to gain insight into patients’ experiences with NET and to identify influencing factors on treatment results. Methods: This study will have a mixed methods convergent design consisting of quantitative repeated measures and qualitative semi-structured in-depth interviews based on Grounded Theory. The study population will include adult SMI outpatients (n=25 with comorbid PTSD and receiving NET. The quantitative study parameters will be existence and severity of PTSD, dissociative, and SMI symptoms; care needs; quality of life; global functioning; and care consumption. In a longitudinal analysis, outcomes will be analyzed using mixed models to estimate the difference in means between baseline and repeated measurements. The qualitative study parameters will be experiences with NET and perceived factors for success or failure. Integration of quantitative and qualitative results will be focused on interpreting how qualitative results

  1. Evaluation of the base/subgrade soil under repeated loading : phase II, in-box and ALF cyclic plate load tests.

    Science.gov (United States)

    2012-03-01

    This research study aims at evaluating the performance of base and subgrade soil in flexible pavements under repeated loading test conditions. For this purpose, an indoor cyclic plate load testing equipment was developed and used to conduct a series ...

  2. Experimental Analysis for Factors Affecting the Repeatability of Plastics Injection Molding Tests on the Self-developed Apparatus

    Directory of Open Access Journals (Sweden)

    Yugang Huang

    2013-06-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 To improve the repeatability of the injection molding test result, the affecting factors were investigated by means of experiments. Besides the traditional processing parameter, the factors of test conditions were also considered. In order to focus on the molding process rather than the molded part, the curve measurement of the melt pressure at the entrance to the nozzle was used as the output characteristic. Experiments for polypropylene (PP showed that the injected volume was the key processing parameter. Within the test conditions, the injection number is the most important factor. According to the analysis the operating procedure was improved effectively. Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Doi: 10.12777/ijse.5.1.6-11 [How to cite this article: Huang, Y., Li, D., Liu, Y. (2013. Experimental Analysis for Factors Affecting the Repeatability of Plastics Injection Molding Tests on the Self-developed Apparatus. International Journal of Science and Engineering, 5(1,6-11. Doi: 10.12777/ijse.5.1.6-11]

  3. Testing Mean Differences among Groups: Multivariate and Repeated Measures Analysis with Minimal Assumptions.

    Science.gov (United States)

    Bathke, Arne C; Friedrich, Sarah; Pauly, Markus; Konietschke, Frank; Staffen, Wolfgang; Strobl, Nicolas; Höller, Yvonne

    2018-03-22

    To date, there is a lack of satisfactory inferential techniques for the analysis of multivariate data in factorial designs, when only minimal assumptions on the data can be made. Presently available methods are limited to very particular study designs or assume either multivariate normality or equal covariance matrices across groups, or they do not allow for an assessment of the interaction effects across within-subjects and between-subjects variables. We propose and methodologically validate a parametric bootstrap approach that does not suffer from any of the above limitations, and thus provides a rather general and comprehensive methodological route to inference for multivariate and repeated measures data. As an example application, we consider data from two different Alzheimer's disease (AD) examination modalities that may be used for precise and early diagnosis, namely, single-photon emission computed tomography (SPECT) and electroencephalogram (EEG). These data violate the assumptions of classical multivariate methods, and indeed classical methods would not have yielded the same conclusions with regards to some of the factors involved.

  4. Testing the Deployment Repeatability of a Precision Deployable Boom Prototype for the Proposed SWOT Karin Instrument

    Science.gov (United States)

    Agnes, Gregory S.; Waldman, Jeff; Hughes, Richard; Peterson, Lee D.

    2015-01-01

    NASA's proposed Surface Water Ocean Topography (SWOT) mission, scheduled to launch in 2020, would provide critical information about Earth's oceans, ocean circulation, fresh water storage, and river discharge. The mission concept calls for a dual-antenna Ka-band radar interferometer instrument, known as KaRIn, that would map the height of water globally along two 50 km wide swaths. The KaRIn antennas, which would be separated by 10 meters on either side of the spacecraft, would need to be precisely deployable in order to meet demanding pointing requirements. Consequently, an effort was undertaken to design build and prototype a precision deployable Mast for the KaRIn instrument. Each mast was 4.5-m long with a required dilitation stability of 2.5 microns over 3 minutes. It required a minimum first mode of 7 Hz. Deployment repeatability was less than +/- 7 arcsec in all three rotation directions. Overall mass could not exceed 41.5 Kg including any actuators and thermal blanketing. This set of requirements meant the boom had to be three times lighter and two orders of magnitude more precise than the existing state of the art for deployable booms.

  5. The effects of chronic cadmium exposure on repeat swimming performance and anaerobic metabolism in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis).

    Science.gov (United States)

    Cunningham, Jessie L; McGeer, James C

    2016-04-01

    This study investigates the effect of chronic Cd exposure on the ability to perform repeat swim challenges in brown trout (Salmo trutta) and lake whitefish (Coregonus clupeaformis). Fish were exposed to waterborne Cd (18nM) in moderately hard water (120mgL(-1) CaCO3) for 30 days. This level of exposure has been shown to cause sublethal physiological disruption and acclimation responses but no impairment of sustained swimming capacity (Ucrit) in single swim challenges. Swim trials were done over the course of the exposure and each one consisted of an initial swim to 85% of the Ucrit of control fish, a 30min recovery period and finally a second swim challenge to determine Ucrit. Plasma and tissue samples were collected before and after each of the swim periods. As expected from previous studies, Cd exposure resulted in significant accumulation of Cd in gills, liver and kidney but not in white muscle. Exposure also induced a loss of plasma Ca followed by subsequent recovery (in lake whitefish but not brown trout) with few mortalities (100% survival for lake whitefish and 93% for brown trout). Both control and exposed fish swam to 85% of the single swim Ucrit and no differences in performance were seen. The Ucrit of unexposed controls in the second swim challenges were not different from the single swim Ucrit. However, second swim performance was significantly reduced in Cd exposed fish, particularly after a week of exposure where 31% and 38% reductions were observed for brown trout and lake whitefish respectively. Swimming to 85% Ucrit resulted in metabolic expenditure with little recovery after 30min. Few differences were observed between control and Cd exposed fish with the exception of a reduction in resting white muscle ATP stores of Cd exposed fish after 1 week of exposure. The results show that chronic sublethal Cd exposure results in an impairment of swimming ability in repeat swim challenges but this impairment is generally not related to metabolic processes

  6. Chip-based human liver-intestine and liver-skin co-cultures--A first step toward systemic repeated dose substance testing in vitro.

    Science.gov (United States)

    Maschmeyer, Ilka; Hasenberg, Tobias; Jaenicke, Annika; Lindner, Marcus; Lorenz, Alexandra Katharina; Zech, Julie; Garbe, Leif-Alexander; Sonntag, Frank; Hayden, Patrick; Ayehunie, Seyoum; Lauster, Roland; Marx, Uwe; Materne, Eva-Maria

    2015-09-01

    Systemic repeated dose safety assessment and systemic efficacy evaluation of substances are currently carried out on laboratory animals and in humans due to the lack of predictive alternatives. Relevant international regulations, such as OECD and ICH guidelines, demand long-term testing and oral, dermal, inhalation, and systemic exposure routes for such evaluations. So-called "human-on-a-chip" concepts are aiming to replace respective animals and humans in substance evaluation with miniaturized functional human organisms. The major technical hurdle toward success in this field is the life-like combination of human barrier organ models, such as intestine, lung or skin, with parenchymal organ equivalents, such as liver, at the smallest biologically acceptable scale. Here, we report on a reproducible homeostatic long-term co-culture of human liver equivalents with either a reconstructed human intestinal barrier model or a human skin biopsy applying a microphysiological system. We used a multi-organ chip (MOC) platform, which provides pulsatile fluid flow within physiological ranges at low media-to-tissue ratios. The MOC supports submerse cultivation of an intact intestinal barrier model and an air-liquid interface for the skin model during their co-culture with the liver equivalents respectively at (1)/100.000 the scale of their human counterparts in vivo. To increase the degree of organismal emulation, microfluidic channels of the liver-skin co-culture could be successfully covered with human endothelial cells, thus mimicking human vasculature, for the first time. Finally, exposure routes emulating oral and systemic administration in humans have been qualified by applying a repeated dose administration of a model substance - troglitazone - to the chip-based co-cultures. Copyright © 2015. Published by Elsevier B.V.

  7. The effects of repeat testing, malingering, and traumatic brain injury on visuospatial memory span

    Directory of Open Access Journals (Sweden)

    David L Woods

    2016-01-01

    Full Text Available Spatial span tests such as the Corsi Block Test (CBT and the spatial span test of the Wechsler Memory Scale are widely used to assess deficits in spatial working memory. We conducted three experiments to evaluate the test-retest reliability and clinical sensitivity of a new computerized spatial span test (C-SST that incorporates psychophysical methods to improve the precision of spatial span measurement. In Experiment 1, we analyzed C-SST test-retest reliability in 49 participants who underwent three test sessions at weekly intervals. Intraclass correlation coefficients (ICC were higher for a psychophysically derived mean span (MnS metric (0.83 than for the maximal span and total correct metrics used in traditional spatial-span tests. Response times (ReTs also showed high ICCs (0.93 that correlated negatively with MnS scores and correlated positively with response-time latencies from other tests of processing speed. Learning effects were insignificant. Experiment 2 examined the performance of Experiment 1 participants when instructed to feign symptoms of traumatic brain injury: 57% showed abnormal MnS z-scores. A MnS z-score cutoff of 3.0 correctly classified 36% of simulated malingerers and 91% of the subgroup of 11 control participants with abnormal spans. Malingerers also made more substitution errors than control participants with abnormal spans (sensitivity = 43%, specificity = 91%. In addition, malingerers showed no evidence of ReT slowing, in contrast to significant abnormalities seen on other malingered tests of processing speed. As a result, differences between ReT z-scores and z-scores on other processing speed tests showed very high sensitivity and specificity in distinguishing malingering and control participants with either normal or abnormal spans. Experiment 3 examined C-SST performance in a group of patients with predominantly mild traumatic brain injury (TBI: neither MnS nor ReT z-scores showed significant group

  8. A case of natalizumab-associated progressive multifocal leukoencephalopathy with repeated negative CSF JCV testing.

    Science.gov (United States)

    Mazda, Monica E; Brosch, Jared R; Wiens, Andrea L; Bonnin, José M; Kamer, Aaron P; Mattson, David H; Snook, Riley J

    2013-05-01

    The development of progressive multifocal leukoencephalopathy (PML) in patients treated with natalizumab is a well-known potential risk. Diagnosis of PML can be confounded in patients with multiple sclerosis (MS) if new demyelinating lesions develop, and the sensitivity of existing diagnostic tests is less than ideal. In the case presented here, four samples of cerebrospinal fluid tested negative for John Cunningham virus (JCV) DNA by polymerase chain reaction, yet brain biopsy eventually proved positive by immunohistochemistry. A review of the limitations of existing clinical diagnostic tests is addressed, and we review the most recent literature on the proper management of natalizumab-treated MS patients.

  9. Repeated sublethal exposures to the sea lice pesticide Salmosan® (azamethiphos) on adult male lobsters (Homarus americanus) causes neuromuscular dysfunction, hypoxia, metabolic disturbances and mortality.

    Science.gov (United States)

    Dounia, Daoud; Andrea, Battison; Lefort, Natalie; Van Geest, Jordana Lynne

    2016-12-01

    In Atlantic Canada and other salmon-growing regions, treatment of sea lice infestations in salmon aquaculture is necessary to protect fish health. The product Salmosan®, which contains the organophosphate azamethiphos as the active ingredient, is a pesticide presently used for treatment against sea lice. It is applied as a bath treatment and then released into the surrounding seawater. The potential for lethality to non-target species following acute and chronic exposures to Salmosan® has been studied over the past decade, however, the potential for sublethal effects on lobsters remains a concern. Adult male lobsters were exposed to 0.06, 0.5, and 5µgL -1 azamethiphos for one hour, repeated five times, over 48h. Lobsters were assessed immediately after exposure and over six days of recovery. Inhibition of muscle cholinesterase activity was detected in lobsters exposed to 0.5 and 5µgL -1 azamethiphos. The 5µgL -1 dose was considered lethal (93% cumulative mortality). Significant changes in hemolymph plasma biochemistry were most apparent in the 5µgL -1 exposure group in the immediate post-exposure samples. Citrate synthase activity was significantly lower in muscles of the 0.5µgL -1 exposure group compared to control lobsters. Mean electron transport system and standard metabolic rates tended to be lower in muscle tissue of the 0.5µgL -1 exposure group than control group lobsters. These results suggest that sublethal effects on lobster energetics may occur under laboratory exposure conditions (i.e., concentrations and duration) considered environmentally relevant, which could result in impairment under natural conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Evaluation of repeatability of Kansas test method KT-73, "density, absorption and voids in hardened concrete," boil test.

    Science.gov (United States)

    2015-06-01

    For years, the Kansas Department of Transportation (KDOT) and concrete producers in the state have used a : Rapid Chloride Test for concrete cylinders, AASHTO T277. This test has been thought of as an appropriate quality : control test to evaluate pe...

  11. Evaluation of repeatability of Kansas test method KT-73, "density, absorption and voids in hardened concrete," boil test : [technical summary].

    Science.gov (United States)

    2015-06-01

    For years, the Kansas Department of Transportation (KDOT) and concrete producers in : the state have used a Rapid Chloride Test for concrete cylinders, AASHTO T277. This : test has been thought of as an appropriate quality control test to evaluate pe...

  12. The Effects of Repeated Testing, Simulated Malingering, and Traumatic Brain Injury on Visual Choice Reaction Time

    Directory of Open Access Journals (Sweden)

    David L Woods

    2015-11-01

    Full Text Available Choice reaction time (CRT, the time required to discriminate and respond appropriately to different stimuli, is a basic measure of attention and processing speed. Here, we describe the reliability and clinical sensitivity of a new CRT test that presents lateralized visual stimuli and adaptively adjusts stimulus onset asynchronies (SOAs using a staircase procedure. Experiment 1 investigated the test-retest reliability in three test sessions at weekly intervals. Performance in the first test session was accurately predicted from age and computer-use regression functions obtained in a previously studied normative cohort. Central processing time (CentPT, the difference between the CRTs and simple reaction time latencies measured in a separate experiment, accounted for 55% of CRT latency and more than 50% of CRT latency variance. Performance improved significantly across the three test sessions. High intraclass correlation coefficients (ICCs were seen for CRTs (0.90, CentPTs (0.87, and an omnibus performance measure (0.81 that combined CRT and minimal SOA (mSOA z-scores. Experiment 2 investigated performance in the same participants when instructed to feign symptoms of traumatic brain injury (TBI: 87% produced abnormal omnibus z-scores. Simulated malingerers showed greater elevations in simple than choice reaction times, and hence reduced CentPTs. Latency-consistency z-scores, based on the difference between the CRTs obtained and those predicted from CentPT latencies, discriminated malingering participants from controls with high sensitivity and specificity. Experiment 3 investigated CRT test performance in military veterans who had suffered combat-related TBI and symptoms of post-traumatic stress disorder and revealed small but significant deficits in performance. The results indicate that the new CRT test shows high test-retest reliability, can assist in detecting participants performing with suboptimal effort, and is sensitive to the effects of

  13. The Hidden Burden of Outpatient Repeat PSA Testing in a Prospective Cohort

    LENUS (Irish Health Repository)

    Browne, E

    2017-05-01

    PSA testing is widespread throughout Europe for diagnostic purposes and follow up. We performed a prospective outpatient cohort study of 250 men (2013-2015) in two hospital sites. Included were those men being followed up by urology with PSA blood testing. First appointments and those men in whom non-PSA tests were ordered by urology were excluded. The median age was 67.2yrs (46-88). Eighty-one point two percent of samples had a combination of 21 different serology tests at an added cost of >€18,000. Abnormal serology resulted in 53 referrals. Twenty-six-six percentof correspondence referenced abnormal serology other than PSA. Follow up of non-PSA test results poses a challenge in an outpatient setting with failure to appropriately follow-up on abnormal results, increased costs, and medico-legal implications. There is currently no Irish legislature in place to safeguard hospital physicians. This study quantifies the levels of expenditure, resources and risk associated with ambulant PSA testing.

  14. Effects of acute and repeated oral exposure to the organophosphate insecticide chlorpyrifos on open-field activity in chicks.

    Science.gov (United States)

    Al-Badrany, Y M A; Mohammad, F K

    2007-11-01

    The effects of the organophosphate insecticide chlorpyrifos on 5min open-field activity were examined in a 7-15 days old chick model. Chlorpyrifos was acutely administered taking into account cholinesterase inhibition and determination of the acute (24h) median lethal dose (LD50). The oral LD50 value of chlorpyrifos in chicks was 18.14mg/kg, with cholinergic toxicosis observed on intoxicated chicks. Chlorpyrifos at the dose rates of 5,10 and 20mg/kg orally produced within 2h signs of cholinergic toxicosis in the chicks and significantly inhibited plasma (40-70%), whole brain (43-69%) and liver (31-46%) cholinesterase activities in a dose-dependent manner. Chlorpyrifos at 2 and 4mg/kg, orally did not produce overt signs of cholinergic toxicosis, but decreased (30, 60 and 90min after dosing) the general locomotor activity of the chicks as seen by a significant increase in the latency to move from the central square of the open-field arena, decreases in the numbers of lines crossed and vocalization score. Repeated daily chlorpyrifos treatments (2 and 4mg/kg, orally) for seven consecutive days also caused hypoactivity in chicks in the open-field behavioral paradigm. Only the high dose of chlorpyrifos (4mg/kg, orally) given repeatedly for 7 days caused significant cholinesterase inhibition in the whole brain (37%) and the liver (22%). In conclusion, chlorpyrifos at single or short-term repeated doses-induced behavioral changes in 7-15 days old chicks, in a model that could be used for further neurobehavioral studies involving subtle effects of organophosphates on chicks.

  15. The ToxBank Data Warehouse: Supporting the Replacement of In Vivo Repeated Dose Systemic Toxicity Testing.

    Science.gov (United States)

    Kohonen, Pekka; Benfenati, Emilio; Bower, David; Ceder, Rebecca; Crump, Michael; Cross, Kevin; Grafström, Roland C; Healy, Lyn; Helma, Christoph; Jeliazkova, Nina; Jeliazkov, Vedrin; Maggioni, Silvia; Miller, Scott; Myatt, Glenn; Rautenberg, Michael; Stacey, Glyn; Willighagen, Egon; Wiseman, Jeff; Hardy, Barry

    2013-01-01

    The aim of the SEURAT-1 (Safety Evaluation Ultimately Replacing Animal Testing-1) research cluster, comprised of seven EU FP7 Health projects co-financed by Cosmetics Europe, is to generate a proof-of-concept to show how the latest technologies, systems toxicology and toxicogenomics can be combined to deliver a test replacement for repeated dose systemic toxicity testing on animals. The SEURAT-1 strategy is to adopt a mode-of-action framework to describe repeated dose toxicity, combining in vitro and in silico methods to derive predictions of in vivo toxicity responses. ToxBank is the cross-cluster infrastructure project whose activities include the development of a data warehouse to provide a web-accessible shared repository of research data and protocols, a physical compounds repository, reference or "gold compounds" for use across the cluster (available via wiki.toxbank.net), and a reference resource for biomaterials. Core technologies used in the data warehouse include the ISA-Tab universal data exchange format, REpresentational State Transfer (REST) web services, the W3C Resource Description Framework (RDF) and the OpenTox standards. We describe the design of the data warehouse based on cluster requirements, the implementation based on open standards, and finally the underlying concepts and initial results of a data analysis utilizing public data related to the gold compounds. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. External exposure estimates for individuals near the Nevada Test Site

    International Nuclear Information System (INIS)

    Henderson, R.W.; Smale, R.F.

    1987-01-01

    Individuals living near the Nevada Test Site were exposed to both beta and gamma radiations from fission products and activation products resulting from the atmospheric testing of nuclear devices. These exposures were functions of the amount of material deposited, the time of arrival of the debris, and the amount of shielding afforded by structures. Results are presented for each of nine generic life styles. These are representative of the living patterns of the people residing in the area. For each event at each location for which data exist, a representative of each life style was closely followed for a period of thirty days. The results of these detailed calculations are then extrapolated to the present. 7 refs., 5 figs., 2 tabs

  17. Repeated exposure to intra-amniotic LPS partially protects against adverse effects of intravenous LPS in preterm lambs.

    Science.gov (United States)

    Gisslen, Tate; Hillman, Noah H; Musk, Gabrielle C; Kemp, Matthew W; Kramer, Boris W; Senthamaraikannan, Paranthaman; Newnham, John P; Jobe, Alan H; Kallapur, Suhas G

    2014-02-01

    Histologic chorioamnionitis, frequently associated with preterm births and adverse outcomes, results in prolonged exposure of preterm fetuses to infectious agents and pro-inflammatory mediators, such as LPS. Endotoxin tolerance-type effects were demonstrated in fetal sheep following repetitive systemic or intra-amniotic (i.a.) exposures to LPS, suggesting that i.a. LPS exposure would cause endotoxin tolerance to a postnatal systemic dose of LPS in preterm sheep. In this study, randomized pregnant ewes received either two i.a. injections of LPS or saline prior to preterm delivery. Following operative delivery, the lambs were treated with surfactant, ventilated, and randomized to receive either i.v. LPS or saline at 30  min of age. Physiologic variables and indicators of systemic and lung inflammation were measured. Intravenous LPS decreased blood neutrophils and platelets values following i.a. saline compared to that after i.a. LPS. Intra-amniotic LPS prevented blood pressure from decreasing following the i.v. LPS, but also caused an increased oxygen index. Intra-amniotic LPS did not cause endotoxin tolerance as assessed by cytokine expression in the liver, lung or plasma, but increased myeloperoxidase-positive cells in the lung. The different compartments of exposure to LPS (i.a. vs i.v.) are unique to the fetal to newborn transition. Intra-amniotic LPS incompletely tolerized fetal lambs to postnatal i.v. LPS.

  18. Intake during repeated exposure to low- and high-energy-dense yogurts by different means of consumption

    NARCIS (Netherlands)

    Hogenkamp, P.S.; Mars, M.; Stafleu, A.; Graaf, C.de

    2010-01-01

    Background: An important question in the regulation of energy intake is whether dietary learning of energy content depends on the food's characteristics, such as texture. Texture might affect the duration of sensory exposure and eating rate. Objective: The objective was to investigate whether a long

  19. Androgen receptor gene CAG repeat length as modifier of the association between Persistent Organohalogen Pollutant exposure markers and semen characteristics

    DEFF Research Database (Denmark)

    Giwercman, Aleksander; Rylander, Lars; Rignell-Hydbom, Anna

    2007-01-01

    OBJECTIVES: Exposure to persistent organohalogen pollutants was suggested to impair male reproductive function. A gene-environment interaction has been proposed. No genes modifying the effect of persistent organohalogen pollutants on reproductive organs have yet been identified. We aimed to inves...

  20. Repeated dose 90-day oral toxicity test of G-7% NANA in rats: An application of new criterion for toxicity determination to test article-induced changes.

    Science.gov (United States)

    Heo, Hye Seon; An, MinJi; Lee, Ji Sun; Kim, Hee Kyong; Park, Yeong-Chul

    2018-06-01

    G-7% NANA is N-acetylneuraminic acid(NANA) containing 7% sialic acid isolated from glycomacropeptide (GMP), a compound of milk. Since NANA is likely to have immunotoxicity, the need to ensure safety for long-term administration has been raised. In this study, a 90-day repeated oral dose toxicity test was performed in rats using G-7% NANA in the dosages of 0, 1250, 2500 and 5000 mg/kg/day.A toxicity determination criterion based on the significant change caused by the administration of the substancewas developed for estimating NOEL, NOAEL and LOAELapplied to this study. When analyzing the immunological markers, no significant changes were observed, even if other significant changes were observed in the high dose group. In accordance with the toxicity determination criterion developed, the NOEL in male and female has been determined as 2500 mg/kg/day, and the NOAEL in females has been determined as 5000 mg/kg/day. The toxicity determination criterion, applied for the first time in the repeated dose toxicity tests, could provide a basis for distinguishing NOEL and NOAEL more clearly; nevertheless, the toxicity determination criterion needs to be supplemented by adding differentiating adverse effects and non-adverse effects based on more experiences of the repeated dose toxicity tests. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Relationship Between Skating Economy and Performance During a Repeated-Shift Test in Elite and Subelite Ice Hockey Players.

    Science.gov (United States)

    Lamoureux, Nicholas R; Tomkinson, Grant R; Peterson, Benjamin J; Fitzgerald, John S

    2018-04-01

    Lamoureux, NR, Tomkinson, GR, Peterson, BJ, and Fitzgerald, JS. Relationship between skating economy and performance during a repeated-shift test in elite and subelite ice hockey players. J Strength Cond Res 32(4): 1109-1113, 2018-The purpose of this study was to determine the importance of skating economy to fatigue during repeated high-intensity efforts of a simulated ice hockey shift. Forty-five collegiate and Junior A male ice hockey players (aged 18-24 years) performed a continuous graded exercise test using a skate treadmill. Breath-by-breath data for oxygen consumption (V[Combining Dot Above]O2) and respiratory exchange ratio were collected and used to derive energy expenditure (EE) averaged over the final 10 seconds of each stage. Economy was determined as the slope of the regression line relating V[Combining Dot Above]O2 and EE against skating speed separately. Participants also completed 8 bouts of maximal ice skating through a course designed to simulate typical shift, with timing gates determining first half, second half, and total fatigue decrement, calculated by a percent decrement score. Partial correlation was used to determine the association between economy measures and decrement during the repeated-shift test. Twenty-six participants met inclusion criteria and were included in data analysis. Skating economy measures (both relative V[Combining Dot Above]O2 and EE) were very likely moderate positive correlates of total fatigue decrement (r [95% confidence interval]: V[Combining Dot Above]O2, 0.46 [0.09, 0.72] and EE, 0.44, [0.06, 0.71]) but not with first or second gate decrement. Our results indicate that skating economy plays an important role in fatigue resistance over repeated on-ice sprints designed to simulate a typical shift. This supports the use of technical skating coaching and training techniques to enhance skating economy as a means of improving ice hockey performance.

  2. Robot-Assisted End-Effector-Based Stair Climbing for Cardiopulmonary Exercise Testing: Feasibility, Reliability, and Repeatability.

    Science.gov (United States)

    Stoller, Oliver; Schindelholz, Matthias; Hunt, Kenneth J

    2016-01-01

    Neurological impairments can limit the implementation of conventional cardiopulmonary exercise testing (CPET) and cardiovascular training strategies. A promising approach to provoke cardiovascular stress while facilitating task-specific exercise in people with disabilities is feedback-controlled robot-assisted end-effector-based stair climbing (RASC). The aim of this study was to evaluate the feasibility, reliability, and repeatability of augmented RASC-based CPET in able-bodied subjects, with a view towards future research and applications in neurologically impaired populations. Twenty able-bodied subjects performed a familiarisation session and 2 consecutive incremental CPETs using augmented RASC. Outcome measures focussed on standard cardiopulmonary performance parameters and on accuracy of work rate tracking (RMSEP-root mean square error). Criteria for feasibility were cardiopulmonary responsiveness and technical implementation. Relative and absolute test-retest reliability were assessed by intraclass correlation coefficients (ICC), standard error of the measurement (SEM), and minimal detectable change (MDC). Mean differences, limits of agreement, and coefficients of variation (CoV) were estimated to assess repeatability. All criteria for feasibility were achieved. Mean V'O2peak was 106±9% of predicted V'O2max and mean HRpeak was 99±3% of predicted HRmax. 95% of the subjects achieved at least 1 criterion for V'O2max, and the detection of the sub-maximal ventilatory thresholds was successful (ventilatory anaerobic threshold 100%, respiratory compensation point 90% of the subjects). Excellent reliability was found for peak cardiopulmonary outcome measures (ICC ≥ 0.890, SEM ≤ 0.60%, MDC ≤ 1.67%). Repeatability for the primary outcomes was good (CoV ≤ 0.12). RASC-based CPET with feedback-guided exercise intensity demonstrated comparable or higher peak cardiopulmonary performance variables relative to predicted values, achieved the criteria for V'O2max

  3. Robot-Assisted End-Effector-Based Stair Climbing for Cardiopulmonary Exercise Testing: Feasibility, Reliability, and Repeatability.

    Directory of Open Access Journals (Sweden)

    Oliver Stoller

    Full Text Available Neurological impairments can limit the implementation of conventional cardiopulmonary exercise testing (CPET and cardiovascular training strategies. A promising approach to provoke cardiovascular stress while facilitating task-specific exercise in people with disabilities is feedback-controlled robot-assisted end-effector-based stair climbing (RASC. The aim of this study was to evaluate the feasibility, reliability, and repeatability of augmented RASC-based CPET in able-bodied subjects, with a view towards future research and applications in neurologically impaired populations.Twenty able-bodied subjects performed a familiarisation session and 2 consecutive incremental CPETs using augmented RASC. Outcome measures focussed on standard cardiopulmonary performance parameters and on accuracy of work rate tracking (RMSEP-root mean square error. Criteria for feasibility were cardiopulmonary responsiveness and technical implementation. Relative and absolute test-retest reliability were assessed by intraclass correlation coefficients (ICC, standard error of the measurement (SEM, and minimal detectable change (MDC. Mean differences, limits of agreement, and coefficients of variation (CoV were estimated to assess repeatability.All criteria for feasibility were achieved. Mean V'O2peak was 106±9% of predicted V'O2max and mean HRpeak was 99±3% of predicted HRmax. 95% of the subjects achieved at least 1 criterion for V'O2max, and the detection of the sub-maximal ventilatory thresholds was successful (ventilatory anaerobic threshold 100%, respiratory compensation point 90% of the subjects. Excellent reliability was found for peak cardiopulmonary outcome measures (ICC ≥ 0.890, SEM ≤ 0.60%, MDC ≤ 1.67%. Repeatability for the primary outcomes was good (CoV ≤ 0.12.RASC-based CPET with feedback-guided exercise intensity demonstrated comparable or higher peak cardiopulmonary performance variables relative to predicted values, achieved the criteria for V'O2

  4. A broad-spectrum sunscreen prevents cumulative damage from repeated exposure to sub-erythemal solar ultraviolet radiation representative of temperate latitudes.

    Science.gov (United States)

    Seité, S; Christiaens, F; Bredoux, C; Compan, D; Zucchi, H; Lombard, D; Fourtanier, A; Young, A R

    2010-02-01

    We have previously shown the detrimental effects of 19 sub-erythemal exposures to daily ultraviolet radiation (DUVR, which mimics non-extreme exposure conditions), delivered over 4 weeks to volunteers. This source had UVA (320-400 nm) to UVB (290-320 nm) irradiance ratio of 25, instead of that close to 10 that is typically the case with solar-simulated radiation (SSR) that represents summer global sunlight with a clear sky and quasi-zenith solar irradiance. Here, we report on an extension of this previous study, in which we evaluated the photoprotection afforded by a broad-spectrum daily-care product with a low-sun protection factor (SPF 8, UVA-PF 7 and 3* rated UVA protection). We assessed cellular and molecular markers of photodamage that are relevant to skin cancer and photoageing. This study shows that biological effects of repeated exposure to DUVR can be prevented by a broad-spectrum daily-care product and that the level of protection afforded varies with the studied endpoint. Efficient daily UVR protection, as provided by a broad-spectrum daily-care product, is necessary to prevent the 'silent' sub-erythemal cumulative effects of UVR from inadvertent sun exposure.

  5. Association between secondhand smoke exposure at home and cigarette gifting and sharing in Zhejiang, China: a repeat cross-sectional study.

    Science.gov (United States)

    Xu, Yue; Xu, ShuiYang; Wu, QingQing; Guo, YuJie

    2016-03-03

    The aims of the current study were to assess the prevalence of household cigarette gifting and sharing, and to evaluate the relationship between secondhand smoke (SHS) exposure, and cigarette gifting and sharing, in Zhejiang, China. A repeat cross-sectional design. 10 sites in 5 cities in Zhejiang, China. Two surveys were conducted with adults in Zhejiang, China, in 2010 (N=2112) and 2012 (N=2279), respectively. At both waves, the same questionnaire was used; respondents were asked questions on residence, number of family smokers, indoor smoking rules, household income and cigarette gifting and sharing. The findings revealed that more than half of respondents' families (54.50% in 2010, 52.79% in 2012) reported exposure to SHS. Many families (54.73% in 2010, 47.04% in 2012) shared cigarettes with others, and a minority (14.91% in 2010, 14.17% in 2012) reported their family giving cigarettes as a gift. There was a significant decrease in cigarette sharing from 2010 to 2012, irrespective of household with SHS exposure status; and the cigarette gifting was significantly decreased in household without SHS exposure. Compared to households without SHS exposure, the prevalence of cigarette gifting and sharing in households with SHS exposure was more obvious. Encouraging and promoting a smoke-free household environment is necessary to change public smoking customs in Zhejiang, China. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  6. Radiation exposure on residents due to semipalatinsk nuclear tests

    International Nuclear Information System (INIS)

    Takada, J.; Hoshi, M.; Nagatomo, T.

    2000-01-01

    Accumulated external radiation doses for residents near Semipalatinsk nuclear test site of the former USSR are presented as a results of the first study by thermoluminescence technique for bricks sampled at several settlements between 1995 and 1997. The external doses which we evaluated from brick dose were up to ∼100 cGy for resident. The external doses at several points in the center of Semipalatinsk city were ∼60 cGy that was remarkably high comparing with the previously reported value based on the military data. A total of 459 nuclear explosions were conducted by the former Union of Soviet Socialist Republics (USSR) from 1949 to 1989 at the Semipalatinsk nuclear test site (SNTS) Kazakhstan, including 87 atmospheric, 26 on the ground, and 364 underground explosions. Total energy release of about 18 Mt equivalent of trinitrotoluene is eleven hundreds times of Hiroshima atomic bomb. However previous reports concerning the effects of radiation on residents near the SNTS based on data provided by the Defense Department of the former USSR do not have direct experimental data concerning effective equivalent dose. They just measured some doses for particular settlements after some nuclear explosions. These do not indicate integrated dose for the residents due to the whole explosions. The technique of thermoluminescence dosimetry (TLD) which had been successfully applied to the dosimetry on Hiroshima and Nagasaki atomic bombs, enabled us to evaluate accumulated external gamma ray doses at specific places due to whole nuclear explosions in the Semipalatinsk test site. TLD technique is well-established one for not only instantaneous exposure like in A-bombs (Hiroshima and Nagasaki) but also prolonged exposure like in dating. Moreover this technique was applicable for dosimetry study of radioactive fallout as shown in studies of Chernobyl accident. The way of external dose estimation from TLD doses for brick will be discussed in case of radioactive fallout. We will

  7. In utero exposure to nanosized carbon black (Printex90) does not induce tandem repeat mutations in female murine germ cells

    DEFF Research Database (Denmark)

    Boisen, Anne Mette Zenner; Shipley, Thomas; Jackson, Petra

    2013-01-01

    Inhalation of particles has been shown to induce mutations in the male germline in mice following both prenatal and adult exposures in several experiments. In contrast, the effects of particles on female germ cell mutagenesis are not well established. Germline mutations are induced during active...... cell division, which occurs during fetal development in females. We investigated the effects of prenatal exposure to carbon black nanoparticles (CB) on induction of mutations in the female mouse germline during fetal development, spanning the critical developmental stages of oogenesis. Pregnant C57BL/6...... mutation rates in the resulting F2 generation were determined from full pedigrees (mother, father, offspring) of F1 female mice (178 CB-exposed and 258 control F2 offspring). ESTR mutation rates in CB-exposed F2 female offspring were not statistically different from those of F2 female control offspring....

  8. Repeated Exposure of Epithelial Cells to Apoptotic Cells Induces the Specific Selection of an Adaptive Phenotype: Implications for Tumorigenesis.

    Science.gov (United States)

    Feng, Lanfei; Vujicic, Snezana; Dietrich, Michael E; Litbarg, Natalia; Setty, Suman; Antoni, Angelika; Rauch, Joyce; Levine, Jerrold S

    2018-05-16

    The consequences of apoptosis extend beyond mere death of the cell. We have shown that receptor-mediated recognition of apoptotic target cells by viable kidney proximal tubular epithelial cells (PTECs) inhibits PTEC proliferation, growth, and survival. Here we tested the hypothesis that continual exposure to apoptotic targets can induce a phenotypic change in responding PTECs, as in other instances of natural selection. In particular, we demonstrate that repeated exposure to apoptotic targets leads to emergence of a PTEC line (denoted BU.MPT SEL ) resistant to apoptotic target-induced death. Resistance is exquisitely specific. Not only are BU.MPT SEL responders fully resistant to apoptotic target-induced death (~85% survival versus exposure in selected versus non-selected responders indicated that the acquired resistance of BU.MPT SEL cells lies in a regulatory step affecting the generation of the pro-apoptotic protein, truncated BH3 interacting-domain death agonist (tBID), most likely at the level of BID cleavage by caspase-8. This specific adaptation has especial relevance for cancer, in which the prominence and persistence of cell death entail magnification of the post-mortem effects of apoptotic cells. Just as cancer cells acquire specific resistance to chemotherapeutic agents, we propose that cancer cells may also adapt to their ongoing exposure to apoptotic targets. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

  9. Eosinophilia and biotoxin exposure in bottlenose dolphins (Tursiops truncatus) from a coastal area impacted by repeated mortality events

    International Nuclear Information System (INIS)

    Schwacke, Lori H.; Twiner, Michael J.; De Guise, Sylvain; Balmer, Brian C.; Wells, Randall S.; Townsend, Forrest I.; Rotstein, David C.; Varela, Rene A.; Hansen, Larry J.; Zolman, Eric S.; Spradlin, Trevor R.

    2010-01-01

    Bottlenose dolphins (Tursiops truncatus) inhabiting coastal waters in the northern Gulf of Mexico have been impacted by recurrent unusual mortality events over the past few decades. Several of these mortality events along the Florida panhandle have been tentatively attributed to poisoning from brevetoxin produced by the dinoflagellate Karenia brevis. While dolphins in other regions of the Florida coast are often exposed to K. brevis blooms, large-scale dolphin mortality events are relatively rare and the frequency and magnitude of die-offs along the Panhandle raise concern for the apparent vulnerability of dolphins in this region. We report results from dolphin health assessments conducted near St. Joseph Bay, Florida, an area impacted by 3 unusual die-offs within a 7-year time span. An eosinophilia syndrome, manifested as an elevated blood eosinophil count without obvious cause, was observed in 23% of sampled dolphins. Elevated eosinophil counts were associated with decreased T-lymphocyte proliferation and increased neutrophil phagocytosis. In addition, indication of chronic low-level exposure to another algal toxin, domoic acid produced by the diatom Pseudo-nitzschia spp., was determined. Previous studies of other marine mammal populations exposed recurrently to Pseudo-nitzschia blooms have suggested a possible link between the eosinophilia and domoic acid exposure. While the chronic eosinophilia syndrome could over the long-term produce organ damage and alter immunological status and thereby increase vulnerability to other challenges, the significance of the high prevalence of the syndrome to the observed mortality events in the St. Joseph Bay area is unclear. Nonetheless, the unusual immunological findings and concurrent evidence of domoic acid exposure in this sentinel marine species suggest a need for further investigation to elucidate potential links between chronic, low-level exposure to algal toxins and immune health.

  10. Eosinophilia and biotoxin exposure in bottlenose dolphins (Tursiops truncatus) from a coastal area impacted by repeated mortality events

    Energy Technology Data Exchange (ETDEWEB)

    Schwacke, Lori H., E-mail: Lori.Schwacke@noaa.gov [National Oceanic and Atmospheric Administration, National Ocean Service, Center for Human Health Risks, 331 Fort Johnson Road, Charleston, SC 29412 (United States); Twiner, Michael J. [National Oceanic and Atmospheric Administration, National Ocean Service, Center for Coastal Environmental Health and Biomolecular Research, 219 Fort Johnson Road, Charleston, SC 29412 (United States); De Guise, Sylvain [University of Connecticut, Department of Pathobiology and Veterinary Science, 61 North Eagleville Road, U-89, Storrs, CT 06269 (United States); Balmer, Brian C.; Wells, Randall S. [Chicago Zoological Society, c/o Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236 (United States); Townsend, Forrest I. [Bayside Hospital for Animals, 251 N.E. Racetrack Road, Fort Walton Beach, FL 32547 (United States); Rotstein, David C. [National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Office of Protected Resources, Marine Mammal Health and Stranding Response Program, 1315 East West Highway, Silver Spring, MD 20910 (United States); Varela, Rene A. [Ocean Embassy Inc, 6433 Pinecastle Blvd, Ste 2, Orlando, FL 32809 (United States); Hansen, Larry J. [National Oceanic and Atmospheric Administration, National Marine Fisheries Service Southeast Fisheries Science Center,101 Pivers Island Road, Beaufort, NC 28516 (United States); Zolman, Eric S. [National Oceanic and Atmospheric Administration, National Ocean Service, Center for Coastal Environmental Health and Biomolecular Research, 219 Fort Johnson Road, Charleston, SC 29412 (United States); Spradlin, Trevor R. [National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Office of Protected Resources, Marine Mammal Health and Stranding Response Program, 1315 East West Highway, Silver Spring, MD 20910 (United States); and others

    2010-08-15

    Bottlenose dolphins (Tursiops truncatus) inhabiting coastal waters in the northern Gulf of Mexico have been impacted by recurrent unusual mortality events over the past few decades. Several of these mortality events along the Florida panhandle have been tentatively attributed to poisoning from brevetoxin produced by the dinoflagellate Karenia brevis. While dolphins in other regions of the Florida coast are often exposed to K. brevis blooms, large-scale dolphin mortality events are relatively rare and the frequency and magnitude of die-offs along the Panhandle raise concern for the apparent vulnerability of dolphins in this region. We report results from dolphin health assessments conducted near St. Joseph Bay, Florida, an area impacted by 3 unusual die-offs within a 7-year time span. An eosinophilia syndrome, manifested as an elevated blood eosinophil count without obvious cause, was observed in 23% of sampled dolphins. Elevated eosinophil counts were associated with decreased T-lymphocyte proliferation and increased neutrophil phagocytosis. In addition, indication of chronic low-level exposure to another algal toxin, domoic acid produced by the diatom Pseudo-nitzschia spp., was determined. Previous studies of other marine mammal populations exposed recurrently to Pseudo-nitzschia blooms have suggested a possible link between the eosinophilia and domoic acid exposure. While the chronic eosinophilia syndrome could over the long-term produce organ damage and alter immunological status and thereby increase vulnerability to other challenges, the significance of the high prevalence of the syndrome to the observed mortality events in the St. Joseph Bay area is unclear. Nonetheless, the unusual immunological findings and concurrent evidence of domoic acid exposure in this sentinel marine species suggest a need for further investigation to elucidate potential links between chronic, low-level exposure to algal toxins and immune health.

  11. Repeated exposure to methamphetamine induces sex-dependent hypersensitivity to ischemic injury in the adult rat heart.

    Directory of Open Access Journals (Sweden)

    Boyd R Rorabaugh

    Full Text Available We previously reported that adult female, but not male rats that were prenatally exposed to methamphetamine exhibit myocardial hypersensitivity to ischemic injury. However, it is unknown whether hypersensitivity to ischemic injury develops when rats are exposed to methamphetamine during adulthood. The goal of this study was to determine whether methamphetamine exposure during adulthood sensitizes the heart to ischemic injury.Adult male and female rats received daily injections of methamphetamine (5 mg/kg or saline for 10 days. Their hearts were isolated on day 11 and subjected to a 20 min ischemic insult on a Langendorff isolated heart apparatus. Cardiac contractile function was measured by an intraventricular balloon, and infarct size was measured by triphenyltetrazolium chloride staining.Hearts from methamphetamine-treated females exhibited significantly larger infarcts and suppressed postischemic recovery of contractile function compared to hearts from saline-treated females. In contrast, methamphetamine had no effect on infarct size or contractile recovery in male hearts. Subsequent experiments demonstrated that hypersensitivity to ischemic injury persisted in female hearts following a 1 month period of abstinence from methamphetamine. Myocardial protein kinase C-ε expression, Akt phosphorylation, and ERK phosphorylation were unaffected by adult exposure to methamphetamine.Exposure of adult rats to methamphetamine sex-dependently increases the extent of myocardial injury following an ischemic insult. These data suggest that women who have a heart attack might be at risk of more extensive myocardial injury if they have a recent history of methamphetamine abuse.

  12. Repeated exposure to methamphetamine induces sex-dependent hypersensitivity to ischemic injury in the adult rat heart

    Science.gov (United States)

    Seeley, Sarah L.; Stoops, Thorne S.; D’Souza, Manoranjan S.

    2017-01-01

    Background We previously reported that adult female, but not male rats that were prenatally exposed to methamphetamine exhibit myocardial hypersensitivity to ischemic injury. However, it is unknown whether hypersensitivity to ischemic injury develops when rats are exposed to methamphetamine during adulthood. The goal of this study was to determine whether methamphetamine exposure during adulthood sensitizes the heart to ischemic injury. Methods Adult male and female rats received daily injections of methamphetamine (5 mg/kg) or saline for 10 days. Their hearts were isolated on day 11 and subjected to a 20 min ischemic insult on a Langendorff isolated heart apparatus. Cardiac contractile function was measured by an intraventricular balloon, and infarct size was measured by triphenyltetrazolium chloride staining. Results Hearts from methamphetamine-treated females exhibited significantly larger infarcts and suppressed postischemic recovery of contractile function compared to hearts from saline-treated females. In contrast, methamphetamine had no effect on infarct size or contractile recovery in male hearts. Subsequent experiments demonstrated that hypersensitivity to ischemic injury persisted in female hearts following a 1 month period of abstinence from methamphetamine. Myocardial protein kinase C-ε expression, Akt phosphorylation, and ERK phosphorylation were unaffected by adult exposure to methamphetamine. Conclusions Exposure of adult rats to methamphetamine sex-dependently increases the extent of myocardial injury following an ischemic insult. These data suggest that women who have a heart attack might be at risk of more extensive myocardial injury if they have a recent history of methamphetamine abuse. PMID:28575091

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  14. Statistical methods for conducting agreement (comparison of clinical tests) and precision (repeatability or reproducibility) studies in optometry and ophthalmology.

    Science.gov (United States)

    McAlinden, Colm; Khadka, Jyoti; Pesudovs, Konrad

    2011-07-01

    The ever-expanding choice of ocular metrology and imaging equipment has driven research into the validity of their measurements. Consequently, studies of the agreement between two instruments or clinical tests have proliferated in the ophthalmic literature. It is important that researchers apply the appropriate statistical tests in agreement studies. Correlation coefficients are hazardous and should be avoided. The 'limits of agreement' method originally proposed by Altman and Bland in 1983 is the statistical procedure of choice. Its step-by-step use and practical considerations in relation to optometry and ophthalmology are detailed in addition to sample size considerations and statistical approaches to precision (repeatability or reproducibility) estimates. Ophthalmic & Physiological Optics © 2011 The College of Optometrists.

  15. Modeling the rate of HIV testing from repeated binary data amidst potential never-testers.

    Science.gov (United States)

    Rice, John D; Johnson, Brent A; Strawderman, Robert L

    2018-01-04

    Many longitudinal studies with a binary outcome measure involve a fraction of subjects with a homogeneous response profile. In our motivating data set, a study on the rate of human immunodeficiency virus (HIV) self-testing in a population of men who have sex with men (MSM), a substantial proportion of the subjects did not self-test during the follow-up study. The observed data in this context consist of a binary sequence for each subject indicating whether or not that subject experienced any events between consecutive observation time points, so subjects who never self-tested were observed to have a response vector consisting entirely of zeros. Conventional longitudinal analysis is not equipped to handle questions regarding the rate of events (as opposed to the odds, as in the classical logistic regression model). With the exception of discrete mixture models, such methods are also not equipped to handle settings in which there may exist a group of subjects for whom no events will ever occur, i.e. a so-called "never-responder" group. In this article, we model the observed data assuming that events occur according to some unobserved continuous-time stochastic process. In particular, we consider the underlying subject-specific processes to be Poisson conditional on some unobserved frailty, leading to a natural focus on modeling event rates. Specifically, we propose to use the power variance function (PVF) family of frailty distributions, which contains both the gamma and inverse Gaussian distributions as special cases and allows for the existence of a class of subjects having zero frailty. We generalize a computational algorithm developed for a log-gamma random intercept model (Conaway, 1990. A random effects model for binary data. Biometrics46, 317-328) to compute the exact marginal likelihood, which is then maximized to obtain estimates of model parameters. We conduct simulation studies, exploring the performance of the proposed method in comparison with

  16. Testing Accuracy and Repeatability of UAV Blocks Oriented with GNSS-Supported Aerial Triangulation

    Directory of Open Access Journals (Sweden)

    Francesco Benassi

    2017-02-01

    Full Text Available UAV Photogrammetry today already enjoys a largely automated and efficient data processing pipeline. However, the goal of dispensing with Ground Control Points looks closer, as dual-frequency GNSS receivers are put on board. This paper reports on the accuracy in object space obtained by GNSS-supported orientation of four photogrammetric blocks, acquired by a senseFly eBee RTK and all flown according to the same flight plan at 80 m above ground over a test field. Differential corrections were sent to the eBee from a nearby ground station. Block orientation has been performed with three software packages: PhotoScan, Pix4D and MicMac. The influence on the checkpoint errors of the precision given to the projection centers has been studied: in most cases, values in Z are critical. Without GCP, the RTK solution consistently achieves a RMSE of about 2–3 cm on the horizontal coordinates of checkpoints. In elevation, the RMSE varies from flight to flight, from 2 to 10 cm. Using at least one GCP, with all packages and all test flights, the geocoding accuracy of GNSS-supported orientation is almost as good as that of a traditional GCP orientation in XY and only slightly worse in Z.

  17. Study on a 4-Week Recovery Test of Sweet Bee Venom after a 13-Week, Repeated, Intramuscular Dose Toxicity Test in Sprague-Dawley Rats

    Directory of Open Access Journals (Sweden)

    Chungsan Lim

    2014-06-01

    Full Text Available Objectives:This study was performed to check for reversibility in the changes induced by a 13-week, repeated, dose toxicity test of Sweet Bee Venom (SBV in Sprague-Dawley (SD rats. Methods:Fifteen male and 15 female SD rats were treated with 0.28 mg/kg of SBV (high-dosage group and the same numbers of male and female SD rats were treated with 0.2 mL/kg of normal saline (control group for 13 weeks. We selected five male and five female SD rats from the high-dosage group and the same numbers of male and female SD rats from the control group, and we observed these rats for four weeks. We conducted body-weight measurements, ophthalmic examinations, urinalyses and hematology, biochemistry, histology tests. Results:(1 Hyperemia and movement disorder were observed in the 13-week, repeated, dose toxicity test, but these symptoms were not observed during the recovery period. (2 The rats in the high-dose group showed no significant changes in weight compared to the control group. (3 No significant differences in the ophthalmic parameters, urine analyses, complete blood cell counts (CBCs, and biochemistry were observed among the recovery groups. (4 No changes in organ weights were observed during the recovery period. (5 Histological examination of the thigh muscle indicated cell infiltration, inflammation, degeneration, necrosis of muscle fiber, and fibrosis during the treatment period, but these changes were not observed during the recovery period. The fatty liver change that was observed during the toxicity test was not observed during the recovery period. No other organ abnormalities were observed. Conclusion:The changes that occurred during the 13-week, repeated, dose toxicity test are reversible, and SBV can be safely used as a treatment modality.

  18. Performance of bias-correction methods for exposure measurement error using repeated measurements with and without missing data.

    Science.gov (United States)

    Batistatou, Evridiki; McNamee, Roseanne

    2012-12-10

    It is known that measurement error leads to bias in assessing exposure effects, which can however, be corrected if independent replicates are available. For expensive replicates, two-stage (2S) studies that produce data 'missing by design', may be preferred over a single-stage (1S) study, because in the second stage, measurement of replicates is restricted to a sample of first-stage subjects. Motivated by an occupational study on the acute effect of carbon black exposure on respiratory morbidity, we compare the performance of several bias-correction methods for both designs in a simulation study: an instrumental variable method (EVROS IV) based on grouping strategies, which had been recommended especially when measurement error is large, the regression calibration and the simulation extrapolation methods. For the 2S design, either the problem of 'missing' data was ignored or the 'missing' data were imputed using multiple imputations. Both in 1S and 2S designs, in the case of small or moderate measurement error, regression calibration was shown to be the preferred approach in terms of root mean square error. For 2S designs, regression calibration as implemented by Stata software is not recommended in contrast to our implementation of this method; the 'problematic' implementation of regression calibration although substantially improved with use of multiple imputations. The EVROS IV method, under a good/fairly good grouping, outperforms the regression calibration approach in both design scenarios when exposure mismeasurement is severe. Both in 1S and 2S designs with moderate or large measurement error, simulation extrapolation severely failed to correct for bias. Copyright © 2012 John Wiley & Sons, Ltd.

  19. Decreased extracellular adenosine levels lead to loss of hypoxia-induced neuroprotection after repeated episodes of exposure to hypoxia.

    Directory of Open Access Journals (Sweden)

    Mei Cui

    Full Text Available Achieving a prolonged neuroprotective state following transient ischemic attacks (TIAs is likely to effectively reduce the brain damage and neurological dysfunction associated with recurrent stroke. HPC is a phenomenon in which advanced exposure to mild hypoxia reduces the stroke volume produced by a subsequent TIA. However, this neuroprotection is not long-lasting, with the effects reaching a peak after 3 days. Therefore, in this study, we investigated the use of multiple episodes of hypoxic exposure at different time intervals to induce longer-term protection in a mouse stroke model. C57BL/6 mice were subjected to different hypoxic preconditioning protocols: a single episode of HPC or five identical episodes at intervals of 3 days (E3d HPC or 6 days (E6d HPC. Three days after the last hypoxic exposure, temporary middle cerebral artery occlusion (MCAO was induced. The effects of these HPC protocols on hypoxia-inducible factor (HIF regulated gene mRNA expression were measured by quantitative PCR. Changes in extracellular adenosine concentrations, known to exert neuroprotective effects, were also measured using in vivo microdialysis and high pressure liquid chromatography (HPLC. Neuroprotection was provided by E6d HPC but not E3d HPC. HIF-regulated target gene expression increased significantly following all HPC protocols. However, E3d HPC significantly decreased extracellular adenosine and reduced cerebral blood flow in the ischemic region with upregulated expression of the adenosine transporter, equilibrative nucleoside transporter 1 (ENT1. An ENT1 inhibitor, propentofylline increased the cerebral blood flow and re-established neuroprotection in E3d HPC. Adenosine receptor specific antagonists showed that adenosine mainly through A1 receptor mediates HPC induced neuroprotection. Our data indicate that cooperation of HIF-regulated genes and extracellular adenosine is necessary for HPC-induced neuroprotection.

  20. Biochemical and histopathological changes in the kidney and adrenal gland of rats following repeated exposure to lambda-cyhalothrin

    OpenAIRE

    Hassina Khaldoun Oularbi

    2014-01-01

    Lambda-cyhalothrin (LCT) is a type II pyrethroid insecticide widely used in pest management. This study was undertaken to evaluate the toxic effects of LCT on the kidneys and adrenal glands of rats after subacute exposure. Twenty-eight 6-week-old male albino Rattus norvegicus rats were randomly assigned to four groups. Group 1 was the control group, which received distilled water. The experimental groups 2, 3 and 4 received 20.4, 30.6 and 61.2 mg/kg body weight, respectively, of LCT, administ...

  1. Prevention of diabetes in NOD mice by repeated exposures to a contact allergen inducing a sub-clinical dermatitis

    DEFF Research Database (Denmark)

    Engkilde, Kaare; Buschard, Karsten; Hansen, Axel Jacob Kornerup

    2010-01-01

    Type 1 diabetes is an autoimmune disease, while allergic contact dermatitis although immune mediated, is considered an exposure driven disease that develops due to epicutaneous contact with reactive low-molecular chemicals. The objective of the present study was to experimentally study the effect...... of contact allergens on the development of diabetes in NOD mice. As the link between contact allergy and diabetes is yet unexplained we also examined the effect of provocation with allergens on Natural Killer T (NKT) cells, since involvement of NKT cells could suggest an innate connection between the two...

  2. TASK 2.5.5 NATURAL EXPOSURE TESTING IN CALIFORNIA

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William A [ORNL; Cheng, Mengdawn [ORNL; New, Joshua Ryan [ORNL; Ronnen, Levinson [Lawrence Berkeley National Laboratory (LBNL); Akbari, Hashem [Lawrence Berkeley National Laboratory (LBNL); Berhahl, Paul [Lawrence Berkeley National Laboratory (LBNL)

    2010-03-01

    Airborne particulate matter that settles on a roof can either reflect or absorb incoming solar radiation, dependent on the chemical content and size of the particles. These light scattering and absorption processes occur within a few microns of the surface, and can affect the solar reflectance of the roof. Wilkes et al. (2000) tested 24 different roof coatings on a low-slope test stand and observed about a 25% decrease in the solar reflectance of white-coated and aluminum-coated surfaces as the time of exposure increased; however, the decrease leveled off after 2 years. SPRI Inc. and its affiliates studied the effect of climatic exposure on the surface properties of white thermoplastic single-ply membranes and determined that membranes lose from 30 to 50% of their reflectance over 3 years (Miller et al. 2002). The CMRC and its affiliates AISI, NamZAC, MBMA, MCA and NCCA exposed unpainted and painted metal roofing on both steep- and low-slope test roofs and found that after 3 years, the painted polyvinylidene fluoride (PVDF) metal roofs lost less than 5% of their original reflectance (Miller et al. 2004). The results of the three different weathering studies are very interesting in terms of their solar reflectance after 3 years of exposure. The white thermoplastic membrane and white ceramic coating with white topcoat had original reflectance measures that were about 20 percentage points higher than the painted metal; however, after 3-years of field exposure the solar reflectance of the painted metal exceeds that of the thermoplastic membrane and equals that of the coating. The long-term loss of reflectance appears driven by the ability of the particulate matter to cling to the roof and resist being washed off by wind and or rain. Miller et al. (2002) discovered that aerosol deposition introduced biomass of complex microbial consortia onto the test roofs and the combination of contaminants and biomass accelerated the loss of solar reflectance for the thermoplastic

  3. Influence of test conditions and exposure duration on the result of ecotoxicological tests

    DEFF Research Database (Denmark)

    Rosenkrantz, Rikke Tjørnhøj

    be calculated from results of ecotoxicological tests performed according to internationally approved guidelines, such as from the Organisation for Economic Co-operation and Development (OECD) or International Standardization Organisation (ISO). Such guidelines were originally developed to enable classification......H and exposure duration on the toxicity recorded in tests using four sulfonylurea herbicides (SUs) and the aquatic macrophyte Lemna gibba as study objects. The study showed that changing the physical and chemical test conditions influenced the toxicity of sulfonylurea herbicides towards L. gibba. Lowering...

  4. Significance of repeated exercise testing with thallium-201 scanning in asymptomatic diabetic males

    International Nuclear Information System (INIS)

    Rubler, S.; Fisher, V.J.

    1985-01-01

    This study was conducted with asymptomatic middle-aged male subjects with diabetes mellitus to detect latent cardiac disease using noninvasive techniques. One group of 38 diabetic males (mean age 50.5 +/- 10.2 years) and a group of 15 normal males (mean age 46.9 +/- 10.0 years) participated in the initial trial; 13 diabetic patients and 7 control subjects were restudied 1-2 years later. Maximal treadmill exercise with a Bruce protocol and myocardial scintigraphy with thallium-201(201Tl) were used. Diabetic subjects on initial examination and retesting achieved a lower maximal heart rate and duration of exercise than control subjects. Abnormal electrocardiographic changes, thallium defects, or both were observed in 23/38 diabetic males (60.5%) on the first study and only one 65-year-old control subject had such findings. On retesting, the control subjects had no abnormalities while 76.9% of diabetic subjects had either 201Tl defects or ECG changes. We conclude that despite the fact that none of diabetic males had any clinical evidence or symptoms of heart disease, this high-risk group demonstrated abnormalities on exercise testing that merit careful subsequent evaluation and followup and could be an effective method of detecting early cardiac disease

  5. Creating multithemed ecological regions for macroscale ecology: Testing a flexible, repeatable, and accessible clustering method

    Science.gov (United States)

    Cheruvelil, Kendra Spence; Yuan, Shuai; Webster, Katherine E.; Tan, Pang-Ning; Lapierre, Jean-Francois; Collins, Sarah M.; Fergus, C. Emi; Scott, Caren E.; Norton Henry, Emily; Soranno, Patricia A.; Filstrup, Christopher T.; Wagner, Tyler

    2017-01-01

    Understanding broad-scale ecological patterns and processes often involves accounting for regional-scale heterogeneity. A common way to do so is to include ecological regions in sampling schemes and empirical models. However, most existing ecological regions were developed for specific purposes, using a limited set of geospatial features and irreproducible methods. Our study purpose was to: (1) describe a method that takes advantage of recent computational advances and increased availability of regional and global data sets to create customizable and reproducible ecological regions, (2) make this algorithm available for use and modification by others studying different ecosystems, variables of interest, study extents, and macroscale ecology research questions, and (3) demonstrate the power of this approach for the research question—How well do these regions capture regional-scale variation in lake water quality? To achieve our purpose we: (1) used a spatially constrained spectral clustering algorithm that balances geospatial homogeneity and region contiguity to create ecological regions using multiple terrestrial, climatic, and freshwater geospatial data for 17 northeastern U.S. states (~1,800,000 km2); (2) identified which of the 52 geospatial features were most influential in creating the resulting 100 regions; and (3) tested the ability of these ecological regions to capture regional variation in water nutrients and clarity for ~6,000 lakes. We found that: (1) a combination of terrestrial, climatic, and freshwater geospatial features influenced region creation, suggesting that the oft-ignored freshwater landscape provides novel information on landscape variability not captured by traditionally used climate and terrestrial metrics; and (2) the delineated regions captured macroscale heterogeneity in ecosystem properties not included in region delineation—approximately 40% of the variation in total phosphorus and water clarity among lakes was at the regional

  6. An accelerated exposure and testing apparatus for building joint sealants.

    Science.gov (United States)

    White, C C; Hunston, D L; Tan, K T; Hettenhouser, J; Garver, J D

    2013-09-01

    The design, fabrication, and implementation of a computer-controlled exposure and testing apparatus for building joint sealants are described in this paper. This apparatus is unique in its ability to independently control and monitor temperature, relative humidity, ultraviolet (UV) radiation, and mechanical deformation. Each of these environmental factors can be controlled precisely over a wide range of conditions during periods of a month or more. Moreover, as controlled mechanical deformations can be generated, in situ mechanical characterization tests can be performed without removing specimens from the chamber. Temperature and humidity were controlled during our experiments via a precision temperature regulator and proportional mixing of dry and moisture-saturated air; while highly uniform UV radiation was attained by attaching the chamber to an integrating sphere-based radiation source. A computer-controlled stepper motor and a transmission system were used to provide precise movement control. The reliability and effectiveness of the apparatus were demonstrated on a model sealant material. The results clearly show that this apparatus provides an excellent platform to study the long-term durability of building joint sealants.

  7. Toxicological evaluation of silver nanoparticles and silver nitrate in rats following 28 days of repeated oral exposure.

    Science.gov (United States)

    Qin, Guangqiu; Tang, Song; Li, Shibin; Lu, Haoliang; Wang, Yanwu; Zhao, Peng; Li, Bin; Zhang, Jiehong; Peng, Liang

    2017-02-01

    The increasing application of silver nanoparticles (AgNPs) has been raising concerns about their potential adverse effects to human and the environment. However, the knowledge on the systemic toxicity of AgNPs in mammalian systems is still limited. The present study investigated the toxicity of PVP-coated AgNPs in rats treated with repeated oral administration, and compared that with equivalent dose of AgNO 3 . Specifically, one hundred male and female rats were orally administrated with particulate or ionic forms of silver (Ag) separately at doses of 0.5 and 1 mg kg -1 body weight daily for 28 days. The results reveal no significant toxic effects of AgNPs and AgNO 3 up to 1 mg kg -1 body weight, with respect to the body weight, organ weight, food intake, and histopathological examination. Ag distribution pattern in organs of rats treated with AgNPs was similar to that of AgNO 3 treated rats, showing liver and kidneys are the main target organs followed by testis and spleen. The total Ag contents in organs were significantly lower in the AgNPs treated rats than those in the AgNO 3 treated rats. However, the comparisons between AgNPs and AgNO 3 treatments further indicated more potent of AgNPs in biochemical and hematological parameters in rats, including red blood cell count (RBC), platelet count (PLT), white blood cell count (WBC) and aspartate transaminase (AST). Results of this study suggested that particulate Ag at least partially contributed to the observed toxicity of AgNPs, and both ionic and particulate Ag should be taken into consideration in toxicological evaluation of AgNPs. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 609-618, 2017. © 2016 Wiley Periodicals, Inc.

  8. Development of immunity against viral and bacterial antigens after repeated exposures to suberythemal doses of ultraviolet light

    Directory of Open Access Journals (Sweden)

    S. A. Snopov

    2012-01-01

    Full Text Available The effects of ultraviolet (UV radiation on human infectious immunity are not well studied. On the one hand, solar and artificial UU sources have been shown to change cytokine levels in human skin, lymphocyte subpopulation counts in parepheral blood, lymphocyte DNA synthesis and prolifarative response to mitogens. On the other hand, there are just only one or two observations suggesting an influence of UV radiation on human infection course. For instance, UV irradiations have been reported to induce a reccurence of orofacial vesicular lesions caused by herpes siplex virus. Moreover, there is a lack of data concerning immune effects of suberythtemal doses of UV in spite of a long history of using them by Russian prophylactic medicine. In this work we questioned whether such suberythemal UV exposures can affect the immune responses of children to infectious conjunctivitis, to simultaneous measles and polio vaccinations and to simultaneous polio and diphtheria-tetanus vaccinations. In peripheral blood of vaccinated children we examined leukocyte counts (monocytes, neutrophils, eosinophils, lymphocytes, percentages of lymphocyte subpopulations (CD3+, CD20+, CD4+, CD8+, CD25+, HLADR+, concentrations of cytokines (IL-1 beta, TNF-alpha, IFN- amma и IL-10, DNA-synthetic activity of lymphocytes and titres of antibodies against measles and diphtheria toxin. We observed no local or systemic reactions to the vaccines in the UV-group while a moderate rise in body temperature occured in several children from unexposed group. In the blood of childeren from UV-group we found increases in CD25+ и HLADR+ cell percentages, IL- 1 beta and IL-10 concentrations, PWMinduced DNA synthesis in mononuclears, and no decreases in formation of antibodies against measles and diphreria. We concluded that suberythemal UV exposures of children modulated their further responses to imminisations perhaps through the activation of a T helper 2-like

  9. Strategies for Controlling Item Exposure in Computerized Adaptive Testing with the Generalized Partial Credit Model

    Science.gov (United States)

    Davis, Laurie Laughlin

    2004-01-01

    Choosing a strategy for controlling item exposure has become an integral part of test development for computerized adaptive testing (CAT). This study investigated the performance of six procedures for controlling item exposure in a series of simulated CATs under the generalized partial credit model. In addition to a no-exposure control baseline…

  10. The rate of repeating X-rays in the medical centers of Jenin District/Palestine and how to reduce patient exposure to radiation

    Science.gov (United States)

    Assi, Abed Al Nasser

    2018-03-01

    Reduction of the patient's received radiation dose to as low as reasonably achievable (ALARA) is based on recommendations of radiation protection organizations such as the International Commission on Radiological Protection (ICRP) and the National Radiological Protection Board (NRPB). The aim of this study was to explore the frequency and characteristics of rejected / repeated radiographic films in governmental and private centers in Jenin city. The radiological centers were chosen based on their high volume of radiographic studies. The evaluation was carried out over a period of four months. The collected data were compiled at the end of each week and entered into a computer for analysis at the end of study. Overall 5000 films (images) were performed in four months, The average repeat rate of radiographic images was 10% (500 films). Repetition rate was the same for both thoracic and abdominal images (42%). The main reason for repeating imaging was inadequate imaging quality (58.2%) and poor film processing (38%). Human error was the most likely reason necessitating the repetition of the radiographs (48 %). Infant and children groups comprised 85% of the patient population that required repetition of the radiographic studies. In conclusion, we have a higher repetition rate of imaging studies compared to the international standards (10% vs. 4-6%, respectively). This is especially noticeable in infants and children, and mainly attributed to human error in obtaining and processing images. This is an important issue that needs to be addressed on a national level due to the ill effects associated with excessive exposure to radiation especially in children, and to reduce cost of the care delivered.

  11. Disposition of Lead (Pb) in Saliva and Blood of Sprague-Dawley Rats Following a Single or Repeated Oral Exposure to Pb-Acetate

    Energy Technology Data Exchange (ETDEWEB)

    Timchalk, Chuck; Lin, Yuehe; Weitz, Karl K.; Wu, Hong; Gies, Richard A.; Moore, Dean A.; Yantasee, Wassana

    2006-05-01

    Biological monitoring for lead (Pb) is usually based upon a determination of blood Pb concentration; however, saliva has been suggested as a non-invasive biological matrix for assessing exposure. To further evaluate the potential utility of saliva for biomonitoring, the disposition of Pb was evaluated in whole blood (WB), red blood cells (RBC), plasma, parotid gland, bone, and saliva following either a single oral dose of 100 mg Pb-acetate/kg body weight in rats or {approx}1-week after 5 sequential daily oral gavage doses of 1, 10, or 100 mg Pb-acetate/kg/day. Saliva volume, pH, total saliva protein, and ?-amylase activity were also determined. At specified times post-dosing groups of animals were anethetized and administered pilocarpine to induce salivation. Saliva was collected, the animals were humanely sacrificed, and tissue samples were likewise collected, weighed, and processed for Pb analysis. Following a single dose exposure to PB-acetate, Pb was detectable in all samples by 30 min post-dosing. For both the single and repeated dose treatments the concentration of Pb was highest in WB and RBC relative to plasma and saliva. However, the Pb rapidly redistributed (within 5-days post-treatment) from the blood into the bone compartment based on the substantial decrease in WB and RBC Pb concentration, and the concurrent increase in bone Pb following repeated exposure at all dose levels. Although there is clear variability in the observed Pb concentrations in plasma and saliva, there was a reasonable correlation (r2=0.922) between the average Pb concentrations in these biological matrices which was consistent with previous observations. The single oral dose of Pb-acetate resulted in a decrease in salivary pH which recovered by 24 hr post-dosing and a decrease in ?-amylase enzyme activity which did recover within 5-days of ceasing exposure. It is currently unclear what impact these slight functional changes may or may not have on Pb salivary clearance rates. These

  12. Comparative electrophysiological evaluation of hippocampal function following repeated inhalation exposures to JP-8, Jet A, JP-5, and the synthetic Fischer Tropsch fuel.

    Science.gov (United States)

    Rohan, Joyce G; McInturf, Shawn M; Miklasevich, Molly K; Gut, Chester P; Grimm, Michael D; Reboulet, James E; Howard, William R; Mumy, Karen L

    2018-01-01

    Exposure to fuels continues to be a concern in both military and general populations. The aim of this study was to examine effects of in vivo rat repeated exposures to different types of jet fuel utilizing microelectrode arrays for comparative electrophysiological (EP) measurements in hippocampal slices. Animals were exposed to increasing concentrations of four jet fuels, Jet Propellant (JP)-8, Jet A, JP-5, or synthetic Fischer Tropsch (FT) fuel via whole-body inhalation for 20 d (6 hr/d, 5 d/week for 28 d) and synaptic transmission as well as behavioral performance were assessed. Our behavioral studies indicated no significant changes in behavioral performance in animals exposed to JP-8, Jet A, or JP-5. A significant deviation in learning pattern during the Morris water maze task was observed in rats exposed to the highest concentration of FT (2000 mg/m 3 ). There were also significant differences in the EP profile of hippocampal neurons from animals exposed to JP-8, Jet A, JP-5, or FT compared to control air. However, these differences were not consistent across fuels or dose dependent. As expected, patterns of EP alterations in brain slices from JP-8 and Jet A exposures were more similar compared to those from JP-5 and FT. Further longitudinal investigations are needed to determine if these EP effects are transient or persistent. Such studies may dictate if and how one may use EP measurements to indicate potential susceptibility to neurological impairments, particularly those that result from inhalation exposure to chemicals or mixtures.

  13. Biochemical and histopathological changes in the kidney and adrenal gland of rats following repeated exposure to lambda-cyhalothrin

    Directory of Open Access Journals (Sweden)

    Hassina Khaldoun Oularbi

    2014-04-01

    Full Text Available Lambda-cyhalothrin (LCT is a type II pyrethroid insecticide widely used in pest management. This study was undertaken to evaluate the toxic effects of LCT on the kidneys and adrenal glands of rats after subacute exposure. Twenty-eight 6-week-old male albino Rattus norvegicus rats were randomly assigned to four groups. Group 1 was the control group, which received distilled water. The experimental groups 2, 3 and 4 received 20.4, 30.6 and 61.2 mg/kg body weight, respectively, of LCT, administered orally over 28 days. The effects of the insecticide on various biochemical parameters were evaluated at 14 and 28 days. Histopathological studies were carried out in the kidneys and adrenal glands at the end of the experiment. Lambda-cyhalothrin, as a pyrethroid insecticide, induced significant increases (P≤0.05 in plasma urea, creatinine, uric acid and glucose concentrations, and alanine aminotransferase and aspartate aminotransferase activities after 14 and 28 days. In the rat plasma samples after 28 days, residual concentrations of LCT 1R, cis,

  14. Tissue identity testing of cancer by short tandem repeat polymorphism: pitfalls of interpretation in the presence of microsatellite instability.

    Science.gov (United States)

    Much, Melissa; Buza, Natalia; Hui, Pei

    2014-03-01

    Tissue identity testing by short tandem repeat (STR) polymorphism offers discriminating power in resolving tissue mix-up or contamination. However, one caveat is the presence of microsatellite unstable tumors, in which genetic alterations may drastically change the STR wild-type polymorphism leading to unexpected allelic discordance. We examined how tissue identity testing results can be altered by the presence of microsatellite instability (MSI). Eleven cases of MSI-unstable (9 intestinal and 2 endometrial adenocarcinomas) and 10 cases of MSI-stable tumors (all colorectal adenocarcinomas) were included. All had been previously tested by polymerase chain reaction testing at 5 National Cancer Institute (NCI) recommended MSI loci and/or immunohistochemistry for DNA mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2). Tissue identity testing targeting 15 STR loci was performed using AmpF/STR Identifiler Amplification. Ten of 11 MSI-unstable tumors demonstrated novel alleles at 5 to 12 STR loci per case and frequently with 3 or more allelic peaks. However, all affected loci showed identifiable germline allele(s) in MSI-high tumors. A wild-type allelic profile was seen in 7 of 10 MSI-stable tumors. In the remaining 3 cases, isolated novel alleles were present at a unique single locus in addition to germline alleles. Loss of heterozygosity was observed frequently in both MSI-stable (6/11 cases) and MSI-unstable tumors (8/10 cases). In conclusion, MSI may significantly alter the wild-type allelic polymorphism, leading to potential interpretation errors of STR genotyping. Careful examination of the STR allelic pattern, high index of suspicion, and follow-up MSI testing are crucial to avoid erroneous conclusions and subsequent clinical and legal consequences. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Corrigendum to "Acute and repeated exposure to social stress reduces gut microbiota diversity in Syrian hamsters" [Behav. Brain Res. 345 (2018) 39-48].

    Science.gov (United States)

    Partrick, Katherine A; Chassaing, Benoit; Beach, Linda Q; McCann, Katharine E; Gewirtz, Andrew T; Huhman, Kim L

    2018-08-01

    Social stress can promote a variety of neuropsychiatric illnesses, many of which have a high co-morbidity with gastrointestinal disorders. Recent data indicate that gastrointestinal microbiota can affect their host's brain and behavior. Syrian hamsters are ideal subjects for social stress research because they are territorial, aggressive, and rapidly form dominant/subordinate relationships. The purpose of this study was to determine if exposure to social stress in hamsters alters gut microbiota in dominants and subordinates after an agonistic encounter and if pre-stress gut microbiota composition is correlated with the outcome of such a conflict. Microbiota composition was assessed via 16S mRNA Illumina sequencing on fecal samples. One agonistic encounter caused a decrease in alpha diversity in both dominant and subordinate animals with a more pronounced decrease after repeated encounters. PERMANOVA analysis of the unweighted unifrac distance revealed a distinct change in beta diversity after one and nine encounters in both dominants and subordinates. Linear discriminant analysis (LEfSE) showed bacteria from the order Lactobacillales were significantly reduced following social stress in both dominants and subordinates, and both groups exhibited increases in phyla Bacteroidetes and decreases in phyla Firmicutes following repeated encounters. LEfSE analysis on samples collected prior to social interaction revealed that some microbial taxa were correlated with a hamster achieving dominant or subordinate status. These data suggest that even an acute exposure to social stress can impact gastrointestinal microbiota and that the state of the microbial community before social stress may predict dominant/subordinate status following a subsequent agonistic encounter. Copyright © 2018.

  16. Repeated exposure to Lutzomyia intermedia sand fly saliva induces local expression of interferon-inducible genes both at the site of injection in mice and in human blood.

    Science.gov (United States)

    Weinkopff, Tiffany; de Oliveira, Camila I; de Carvalho, Augusto M; Hauyon-La Torre, Yazmin; Muniz, Aline C; Miranda, Jose Carlos; Barral, Aldina; Tacchini-Cottier, Fabienne

    2014-01-01

    During a blood meal, Lutzomyia intermedia sand flies transmit Leishmania braziliensis, a parasite causing tegumentary leishmaniasis. In experimental leishmaniasis, pre-exposure to saliva of most blood-feeding sand flies results in parasite establishment in absence of any skin damages in mice challenged with dermotropic Leishmania species together with saliva. In contrast, pre-immunization with Lu. intermedia salivary gland sonicate (SGS) results in enhanced skin inflammatory exacerbation upon co-inoculation of Lu. intermedia SGS and L. braziliensis. These data highlight potential unique features of both L. braziliensis and Lu. intermedia. In this study, we investigated the genes modulated by Lu. intermedia SGS immunization to understand their potential impact on the subsequent cutaneous immune response following inoculation of both SGS and L. braziliensis. The cellular recruitment and global gene expression profile was analyzed in mice repeatedly inoculated or not with Lu. intermedia. Microarray gene analysis revealed the upregulation of a distinct set of IFN-inducible genes, an immune signature not seen to the same extent in control animals. Of note this INF-inducible gene set was not induced in SGS pre-immunized mice subsequently co-inoculated with SGS and L. braziliensis. These data suggest the parasite prevented the upregulation of this Lu. intermedia saliva-related immune signature. The presence of these IFN-inducible genes was further analyzed in peripheral blood mononuclear cells (PBMCs) sampled from uninfected human individuals living in a L. braziliensis-endemic region of Brazil thus regularly exposed to Lu. intermedia bites. PBMCs were cultured in presence or absence of Lu. intermedia SGS. Using qRT-PCR we established that the IFN-inducible genes induced in the skin of SGS pre-immunized mice, were also upregulated by SGS in PBMCs from human individuals regularly exposed to Lu. intermedia bites, but not in PBMCs of control subjects. These data demonstrate

  17. Acute effects of two different initial heart rates on testing the Repeated Sprint Ability in young soccer players.

    Science.gov (United States)

    Ruscello, B; Briotti, G; Tozzo, N; Partipilo, F; Taraborelli, M; Zeppetella, A; Padulo, J; D'Ottavio, S

    2015-10-01

    The aim of this paper was to investigate the acute effects of two different initial heart rates intensities when testing the repeated sprint ability (RSA) performances in young soccer players. Since there are many kinds of pre-match warm-ups, we chose to take as an absolute indicator of internal load the heart rate reached at the end of two different warm-up protocols (60 vs. 90% HRmax) and to compare the respective RSA performances. The RSA tests were performed on fifteen male soccer players (age: 17.9±1.5 years) with two sets of ten shuttle-sprints (15+15 m) with a 1:3 exercise to rest ratio, in different days (randomized order) with different HR% (60 & 90% HRmax). In order to compare the different sprint performances a Fatigue Index (FI%) was computed, while the blood lactate concentrations (BLa-) were measured before and after testing, to compare metabolic demand. Significant differences among trials within each sets (Psoccer player operates during a real match. This background may be partially reproduced by warming up protocols that, by duration and metabolic commitment, can reproduce conveniently the physiological conditions encountered in a real game (e.g. HRmax≈85-95%; BLa->4 mmol/L(-1)).

  18. Historical estimates of external gamma exposure and collective external gamma exposure from testing at the Nevada Test Site. II. Test series after Hardtack II, 1958, and summary

    International Nuclear Information System (INIS)

    Anspaugh, L.R.; Ricker, Y.E.; Black, S.C.; Grossman, R.F.; Wheeler, D.L.; Church, B.W.; Quinn, V.E.

    1990-01-01

    The historical data on the cumulative individual external gamma exposures are tabulated for communities around the Nevada Test Site for the time periods of 1961 to the signing of the Limited Test Ban Treaty on 5 August 1963, and from then until 1975. The collective exposures during the two time periods are calculated to be 610 and 320 person-R, respectively. The total collective external gamma exposure from 1951 through 1975 for these communities s calculated to be 86,000 person-R. The area considered includes the countries of Clark, Lincoln, Nye, and White Pine in Nevada and the countries of Iron and Washington in Utah; inclusion of Salt Lake City would have substantially increased the calculated collective exposure because of the large population. The methods of calculation are reviewed. Also, the historical data on the assessment of dose via ingestion are reviewed with emphasis on the dose to the thyroid of infants living in St. George, UT, at the time of fallout from event HARRY on 19 May 1953

  19. The Development of Testing Methods for Characterizing Emissions and Sources of Exposures from Polyurethane Products

    Science.gov (United States)

    The relationship between onsite manufacture of spray polyurethane foam insulation (SPFI) and potential exposures is not well understood. Currently, no comprehensive standard test methods exist for characterizing and quantifying product emissions. Exposures to diisocyanate compoun...

  20. Suitability and repeatability of a photostress recovery test device, the macular test device, macular degeneration TEST DEVICE, detector (MDD-2), for diabetes and diabetic retinopathy assessment

    LENUS (Irish Health Repository)

    Loughman, James

    2013-10-16

    Diabetic retinopathy can result in impaired photostress recovery time despite normal visual acuity and fundoscopic appearance. The Macular Degeneration Detector (MDD-2) is a novel flash photostress recovery time device. In this study, we examine the repeatability of the MDD-2 in normal and diabetic subjects.

  1. Study of four weeks repeated-dose toxic test of Sweet Bee Venom in rats Original Articles

    Directory of Open Access Journals (Sweden)

    Kwon Hae-Yon

    2011-03-01

    Full Text Available Objectives: This study was performed to analyse four weeks repeated -dose toxicity of Sweet Bee Venom (SBV-pure melittin, the major component of honey bee venom in rats. Methods: All experiments were conducted under the regulations of Good Laboratory Practice (GLPat Biotoxtech Company, a non-clinical study authorized institution. Male and female rats of 5 weeks old were chosen for the pilot study of four weeks repeated-dose toxicity and was injected at the level of 0.56 mg/kg body weight (eighty times higher than the clinical application dosage as the high dosage, followed by 0.28 and 0.14 mg/kg as midium and low dosage, respectively. Equal amount of normal saline was injected as the control group every day for four weeks. Results: 1. No mortality was witnessed in all of the experiment groups. 2. All experiment groups appealed pain sense in the treating time compared to the control group, and side effects such as hyperemia and movement disorder were observed around the area of injection in all experiment groups, and the higher dosage in treatment, the higher occurrence in side effects. 3. Concerning weight measurement, neither male nor female groups showed significant changes compared to the control group. 4. Concerning to the CBC and biochemistry, all experiment groups didn't show any significant changes compared to the control group. 5. Concerning weight measurement of organs, experiment groups didn't show any significant changes compared to the control group. 6. To verify abnormalities of organs and tissues, those such as cerebellum, cerebrum, liver, lung, kidney,and spinal cords were removed and we conducted histologocal observation with H-E staining.Concerning the histologocal observation of liver tissues, some fatty changes were observed around portal vein in 0.56 mg/kg experiment group. But another organs were not detected in any abnormalities. 7. The proper high dosage of SBV for the thirteen weeks repeated test in rats may be 0.28 mg

  2. Food acceptability in field studies with US army men and women: relationship with food intake and food choice after repeated exposures.

    Science.gov (United States)

    de Graaf, Cees; Kramer, F Matthew; Meiselman, Herbert L; Lesher, Larry L; Baker-Fulco, Carol; Hirsch, Edward S; Warber, John

    2005-02-01

    Laboratory data with single exposures showed that palatability has a positive relationship with food intake. The question addressed in this study is whether this relationship also holds over repeated exposures in non-laboratory contexts in more natural environments. The data were collected in four field studies, lasting 4-11 days with 307 US Army men and 119 Army women, and comprised 5791 main meals and 8831 snacks in total. Acceptability was rated on the nine point hedonic scale, and intake was registered in units of 1/4, 1/2, 3/4, or 1 or more times of the provided portion size. Correlation coefficients between individual acceptability ratings and intakes varied from 0.22 to 0.62 for the main meals (n=193-2267), and between 0.13 and 0.56 for the snacks (n=304-2967). The likelihood of choosing a meal for the second time was positively related to the acceptability rating of the meal when it was consumed for the first time. The results reinforce the importance of liking in food choice and food intake/choice behavior. However, the magnitude of the correlation coefficients between acceptability ratings and food intake suggest that environmental factors also have an important role in determining intake and choice.

  3. INFLUENCE OF MORINGA OLEIFERA (DRUM-STICK FRUIT EXTRACT ON HAEMATOLOGICAL PROFILE FOLLOWING REPEATED EXPOSURE TO LOW LEVELS OF ARSENIC THROUGH FEED ON RATS

    Directory of Open Access Journals (Sweden)

    Vaibhav R. Pachade

    2012-01-01

    Full Text Available Effect of Moringa oleifera fruits hot methanolic extract (MFE, if any, in minimizing the adverse reactions of repeated exposure to arsenic trioxide (AT in feed was investigated in Wistar rats with reference to haematological profile. Three groups of rats each containing 10 (5male+5female were used. The group I served as negative control. Rats of group II were fed arsenic trioxide (AT alone @ 100 ppm in feed while those of group III simultaneously received AT (@100 ppm and MFE (50 mg/kg/day for 28 days. Blood samples were collected from retroorbital plexus for estimation of hematological parameters (haemoglobin, PCV, TEC, MCH, MCHC, MCV of different groups on 0 day, 15th day and 29th day respectively. Exposure to AT through feed in group II resulted in significant (P<0.05 decrease in haemoglobin, TEC and MCHC, accompanied by increased MCV, with no significant alteration of PCV or MCH of the rats. While rats of group III treated with AT (@100 ppm and MFE (50 mg/kg/day also resulted in same consequences as it was in group II but it was slightly less than that of group II suggesting of mild non significant protective effect.

  4. Repeated Acute Oral Exposure to Cannabis sativa Impaired Neurocognitive Behaviours and Cortico-hippocampal Architectonics in Wistar Rats.

    Science.gov (United States)

    Imam, A; Ajao, M S; Akinola, O B; Ajibola, M I; Ibrahim, A; Amin, A; Abdulmajeed, W I; Lawal, Z A; Ali-Oluwafuyi, A

    2017-03-06

    The most abused illicit drug in both the developing and the developed world is Cannabis disposing users to varying forms of personality disorders. However, the effects of cannabis on cortico-hippocampal architecture and cognitive behaviours still remain elusive.  The present study investigated the neuro-cognitive implications of oral cannabis use in rats. Eighteen adult Wistar rats were randomly grouped to three. Saline was administered to the control rats, cannabis (20 mg/kg) to the experimental group I, while Scopolamine (1 mg/kg. ip) was administered to the last group as a standard measure for the cannabis induced cognitive impairment. All treatments lasted for seven consecutive days. Open Field Test (OFT) was used to assess locomotor activities, Elevated Plus Maze (EPM) for anxiety-like behaviour, and Y maze paradigm for spatial memory and data subjected to ANOVA and T test respectively. Thereafter, rats were sacrificed and brains removed for histopathological studies. Cannabis significantly reduced rearing frequencies in the OFT and EPM, and increased freezing period in the OFT. It also reduced percentage alternation similar to scopolamine in the Y maze, and these effects were coupled with alterations in the cortico-hippocampal neuronal architectures. These results point to the detrimental impacts of cannabis on cortico-hippocampal neuronal architecture and morphology, and consequently cognitive deficits.

  5. Induction of enhanced acoustic startle response by noise exposure: dependence on exposure conditions and testing parameters and possible relevance to hyperacusis.

    Directory of Open Access Journals (Sweden)

    Rony H Salloum

    Full Text Available There has been a recent surge of interest in the development of animal models of hyperacusis, a condition in which tolerance to sounds of moderate and high intensities is diminished. The reasons for this decreased tolerance are likely multifactorial, but some major factors that contribute to hyperacusis are increased loudness perception and heightened sensitivity and/or responsiveness to sound. Increased sound sensitivity is a symptom that sometimes develops in human subjects after acoustic insult and has recently been demonstrated in animals as evidenced by enhancement of the acoustic startle reflex following acoustic over-exposure. However, different laboratories have obtained conflicting results in this regard, with some studies reporting enhanced startle, others reporting weakened startle, and still others reporting little, if any, change in the amplitude of the acoustic startle reflex following noise exposure. In an effort to gain insight into these discrepancies, we conducted measures of acoustic startle responses (ASR in animals exposed to different levels of sound, and repeated such measures on consecutive days using a range of different startle stimuli. Since many studies combine measures of acoustic startle with measures of gap detection, we also tested ASR in two different acoustic contexts, one in which the startle amplitudes were tested in isolation, the other in which startle amplitudes were measured in the context of the gap detection test. The results reveal that the emergence of chronic hyperacusis-like enhancements of startle following noise exposure is highly reproducible but is dependent on the post-exposure thresholds, the time when the measures are performed and the context in which the ASR measures are obtained. These findings could explain many of the discrepancies that exist across studies and suggest guidelines for inducing in animals enhancements of the startle reflex that may be related to hyperacusis.

  6. The sensitization potential of sunscreen after ablative fractional skin resurfacing using modified human repeated insult patch test.

    Science.gov (United States)

    Boonchai, Waranya; Sathaworawong, Angkana; Wongpraparut, Chanisada; Wanitphakdeedecha, Rungsima

    2015-10-01

    Ablative fractional skin resurfacing has become popular and proven to be useful in treating scars, photoaging and wrinkles. Although post-inflammatory hyperpigmentation (PIH) is the most common complication especially in dark-skinned patients like Asian. Several modalities have been used to overcome the PIH. To determine the sensitization potential of sunscreen applied immediately after ablative fractional skin resurfacing. Sixty volunteers were recruited. Of these 30 subjects were from previous ablative fractional skin resurfacing study who applied broad-spectrum sunscreen containing anti-inflammatory agent starting on the first day after resurfacing and another 30 non-resurfacing subjects had applied the same sunscreen on the intact skin. All subjects were patch/photopatch tested for sensitization study by using modified human repeated insult patch test (HRIPT). There were significantly higher sensitization rate of UV-filter, octocrylene and the sunscreen in resurfacing group than in non-resurfacing group. Early application of sunscreen after ablative fractional skin resurfacing has increased the incidence of sensitization potential of sunscreen. The sunscreen is recommended to start using from D3 after fractional ablative skin resurfacing to ensure the complete recovery of skin barrier and minimize the risk of sensitization.

  7. Motormouth: Mere Exposure Depends on Stimulus-Specific Motor Simulations

    Science.gov (United States)

    Topolinski, Sascha; Strack, Fritz

    2009-01-01

    The authors apply an embodied account to mere exposure, arguing that through the repeated exposure of a particular stimulus, motor responses specifically associated to that stimulus are repeatedly simulated, thus trained, and become increasingly fluent. This increased fluency drives preferences for repeated stimuli. This hypothesis was tested by…

  8. Polybrominated Diphenyl Ether Exposure and Thyroid Function Tests in North American Adults.

    Science.gov (United States)

    Makey, Colleen M; McClean, Michael D; Braverman, Lewis E; Pearce, Elizabeth N; He, Xue-Mei; Sjödin, Andreas; Weinberg, Janice M; Webster, Thomas F

    2016-04-01

    Polybrominated diphenyl ethers (PBDEs) are flame-retardant chemicals that are added to many consumer products. Multiple animal studies have shown PBDEs to be thyroid hormone (TH) disruptors. Epidemiologic evidence of PBDE exposure associated with TH disruption has been inconclusive. We used repeated measures to estimate associations between serum PBDE concentrations and THs in a North American adult cohort. From 2010 to 2011, we collected ≤ 3 serum samples at approximately 6-month intervals from 52 healthy adult office workers from Boston, Massachusetts, for analysis of PBDE congeners and THs. The geometric mean sum concentrations of the most prevalent PBDE congeners (BDE-28, BDE-47, BDE-99, BDE-100, and BDE-153) were 22 ng/g lipid in winter 2010, 23 ng/g lipid in summer 2010, and 19 ng/g lipid in winter 2011. BDE-47 was the predominant congener. Based on a multivariable mixed regression model, we estimated that on average, a 1-ng/g serum increase in BDE-47 was associated with a 2.6-μg/dL decrease in total thyroxine (T4) (95% CI: -4.7, -0.35). Total T4 was inversely associated with each PBDE congener. Serum concentrations of PBDEs were not strongly associated with total triiodothyronine (T3), free T4, or thyroid-stimulating hormone (TSH). These results are consistent with those from animal studies showing that exposure to PBDEs is associated with a decrease in serum T4. Because the other TH concentrations did not appear to be associated with BDE exposures, our findings do not indicate effects on the pituitary-thyroid axis. Taken together, our findings suggest that PBDE exposure might decrease the binding of T4 to serum T4 binding proteins. Makey CM, McClean MD, Braverman LE, Pearce EN, He XM, Sjödin A, Weinberg JM, Webster TF. 2016. Polybrominated diphenyl ether exposure and thyroid function tests in North American adults. Environ Health Perspect 124:420-425; http://dx.doi.org/10.1289/ehp.1509755.

  9. Influence of enrichment on behavioral and neurogenic effects of antidepressants in Wistar rats submitted to repeated forced swim test.

    Science.gov (United States)

    Possamai, Fernanda; dos Santos, Juliano; Walber, Thais; Marcon, Juliana C; dos Santos, Tiago Souza; Lino de Oliveira, Cilene

    2015-04-03

    Repeated forced swimming test (rFST) may detect gradual effects of antidepressants in adult rats. Antidepressants, as enrichment, affected behavior and neurogenesis in rats. However, the influence of enrichment on behavioral and neurogenic effects of antidepressants is unknown. Here, effects of antidepressants on rFST and hippocampal neurogenesis were investigated in rats under enriched conditions. Behaviors of male Wistar rats, housed from weaning in standard (SE) or enriched environment (EE), were registered during rFST. The rFST consisted of 15min of swimming (pretest) followed by 5min of swimming in the first (test), seventh (retest 1) and fourteenth (retest 2) days after pretest. One hour before the test, rats received an intraperitoneal injection of saline (1ml/kg), fluoxetine (2.5mg/kg) or imipramine (2.5 or 5mg/kg). These treatments were performed daily until the day of the retest 2. After retest 2, rats were euthanized for the identification of markers for neurogenesis in the hippocampus. Fluoxetine or imipramine decreased immobility in retests 1 and 2, as compared to saline. EE abolished these differences. In EE, fluoxetine or imipramine (5mg/kg) reduced immobility time in retest 2, as compared to the test. Independent of the housing conditions, fluoxetine and imipramine (5mg/kg) increased the ratio of immature neurons per progenitor cell in the hippocampus. In summary, antidepressants or enrichment counteracted the high immobility in rFST. Enrichment changed the effects of antidepressants in rFST depending on the type, and the dose of a substance but failed to change neurogenesis in control or antidepressant treated-rats. Effects of antidepressants and enrichment on rFST seemed neurogenesis-independent. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Test-retest repeatability of strength capacity, aerobic power and pericranial tenderness of neck and shoulder muscles in children - relevant for tension-type headache

    DEFF Research Database (Denmark)

    Tornøe, Birte; Andersen, Lars L; Skotte, J H

    2013-01-01

    Frequent or chronic tension-type headache in children is a prevalent and debilitating condition for the child, often leading to medication overuse. To explore the relationship between physical factors and tension-type headache in children, the quality of repeated measures was examined. The aim of...... of the present study was to determine the test-retest repeatability of parameters determining isometric neck and shoulder strength and stability, aerobic power, and pericranial tenderness in children....

  11. Stress responses in juvenile pacu (Piaractus mesopotamicus submitted to repeated air exposure - DOI: 10.4025/actascianimsci.v30i1.3618 Stress responses in juvenile pacu (Piaractus mesopotamicus submitted to repeated air exposure - DOI: 10.4025/actascianimsci.v30i1.3618

    Directory of Open Access Journals (Sweden)

    Leonardo Susumu Takahashi

    2008-06-01

    Full Text Available Juvenis de pacu (5,2 Pacu juveniles (5.2 ± 1.5 g were submitted to two one-minute air exposures in a 24 h interval, and sampled before the exposure (control and 5, 15, 30 and 60 min, 24 and 48 h afterwards for whole-body cortisol, sodium, potassium and calcium ion concentrations. For the first air exposure, there was a trend of increased cortisol concentration after 15 min, whereas in the second air exposure, the cortisol concentration increased significantly within 5 min after stress was induced. Sodium ion concentration increased significantly 24 h after both air exposures. Potassium concentration presented fluctuations over the experimental period. Calcium ion concentration increased progressively from 5 to 30 min, in both air exposures. The repeated air exposures exacerbated the cortisol response, but they did not affect the recovery ability of pacu over the experimental period. Additionally, the whole-body cortisol measurement might be a reliable indicator of stress, when sampled fish are smaller and blood volumes are very low, making samples inadequate for analysis1,5 g foram submetidos a duas exposições aéreas de um minuto, em intervalo de 24 horas, e amostrados antes da exposição (controle e 5, 15, 30 e 60 min, 24 e 48 horas depois para análise da concentração corporal de cortisol e dos íons sódio, potássio e cálcio. Na primeira exposição, os peixes apresentaram concentrações de cortisol aumentadas a partir de 15 min, embora não diferissem estatisticamente do controle. Na segunda exposição, a concentração de cortisol aumentou significativamente aos 5 min, retornando às concentrações equivalentes às dos peixes-controle em 30 min. A concentração do íon sódio aumentou significativamente 24 horas depois das duas exposições aéreas. A concentração do íon potássio apresentou flutuações durante o experimento, enquanto a do cálcio apresentou-se reduzida aos 5 min, aumentando gradativamente até os 30 min

  12. Repeated Strains, Social Control, Social Learning, and Delinquency: Testing an Integrated Model of General Strain Theory in China

    Science.gov (United States)

    Bao, Wan-Ning; Haas, Ain; Chen, Xiaojin; Pi, Yijun

    2014-01-01

    In Agnew's general strain theory, repeated strains can generate crime and delinquency by reducing social control and fostering social learning of crime. Using a sample of 615 middle-and high-school students in China, this study examines how social control and social learning variables mediate the effect of repeated strains in school and at home on…

  13. The effect of repeated measurements and working memory on the most comfortable level in the ANL test

    DEFF Research Database (Denmark)

    Brännström, K Jonas; Olsen, Steen Østergaard; Holm, Lucas

    2014-01-01

    interleaved methodology during one session using a non-semantic version. Phonological (PWM) and visuospatial working memory (VSWM) was measured. STUDY SAMPLE: Thirty-two normal-hearing adults. RESULTS: Repeated measures ANOVA, intraclass correlations, and the coefficient of repeatability (CR) were used...

  14. Repeated Intramuscular-dose Toxicity Test of Water-soluble Carthami Flos (WCF Pharmacopuncture in Sprague-Dawley Rats

    Directory of Open Access Journals (Sweden)

    Yoo-min Choi

    2015-03-01

    Full Text Available Objectives: Water-soluble carthami flos (WCF is a new mixture of Carthami flos (CF pharmacopuncture. We conducted a 4-week toxicity test of repeated intramuscular injections of WCF in Sprague-Dawley rats. Methods: Forty male and 40 female rats were divided into 4 groups of 10 male and 10 female SD rats: The control group received 0.5 mL/animal/day of normal saline whereas the three experimental groups received WCF at doses of 0.125, 0.25, and 0.5 mL/animal/day, respectively. For 4 weeks, the solutions were injected into the femoral muscle of the rats alternating from side to side. Clinical signs, body weights, and food consumption were observed; opthalmological examinations and urinalyses were performed. On day 29, blood samples were taken for hematological and clinical chemistry analyses. Then, necropsy was conducted in all animals to observe weights and external and histopathological changes in the bodily organs. All data were tested using a statistical analysis system (SAS. Results: No deaths were observed. Temporary irregular respiration was observed in male rats of the experimental group for the first 10 days. Body weights, food consumptions, opthalmological examinations, urinalyses, clinical chemistry analyses, organ weights and necropsy produced no findings with toxicological meaning. In the hematological analysis, delay of prothrombin time (PT was observed in male rats of the 0.25- and the 0.5-mL/animal/day groups. In the histopathological test, a dose-dependent inflammatory cell infiltration into the fascia and panniculitis in perimuscular tissues was observed in all animals of the experimental groups. However, those symptoms were limited to local injection points. No toxicological meanings, except localized changes, were noted. Conclusion: WCF solution has no significant toxicological meaning, but does produce localized symptoms. No observed adverse effect level (NOAEL of WCF in male and female rats is expected for doses over 0.5 mL/animal/day.

  15. SU-F-I-67: Neurometabolic Effect Induced by Repeated Exposure to Dizocilpine On Prefrontal Cortex of Schizophrenic Animal Model Using In Vivo Proton Magnetic Resonance Spectroscopy at 9.4 T

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, C-H; Lim, S-I [Department of Biomedical Engineering, and Research Institute of Biomedical Engineering, The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of); Asan Institute for Life Sciences, Asan Medical Center, Seoul (Korea, Republic of); Song, K-H; Choe, B-Y [Department of Biomedical Engineering, and Research Institute of Biomedical Engineering, The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of); Woo, D-C [Asan Institute for Life Sciences, Asan Medical Center, Seoul (Korea, Republic of)

    2016-06-15

    Purpose: Repeated exposure of dizocilpine (MK-801) can provide a pathophysiological model for progressive development of schizophrenia. In vivo proton magnetic resonance spectroscopy ({sup 1}H MRS) was widely used for non-invasive measurement of neurometabolites, and assessment of disease-induced neurometabolic alterations. The purpose of this study was to investigate neurometabolic alteration in prefrontal cortex (PFC) with respect to progression (from first-episode to chronic stage) of schizophrenia by using in vivo {sup 1}H MRS. Methods: We used high-field {sup 1}H MRS to investigate the neurometabolic alteration in the PFC region of the rats (N = 13) by comparing before and after 6 day of MK-801 (0.5 mg/kg) treatment. A point-resolved spectroscopy (PRESS) sequence was used to obtain spectra in a 22.5 µL of volume of interest carefully located in PFC region with parameters like follow; repetition time, 5000ms; echo time (TE), 13.4 ms; averages = 256. Another experiment group (N = 11) were conducted behavior test by recording the behavior for 20 min. Results: All the rats showed hyperlocomotion, stereotyped behaviors before initiation of MRS. Significantly increased level (N = 7, p < 0.05) of N-acetylasrparate (NAA), glutamate (Glu), taurine and decreased level (N = 6, p < 0.05) of NAA, Glu and phosphocreatine were observed between baseline and day 6. Both metabolic alterations are consistent with results of first-episode and chronic schizophrenia respectively. Conclusion: From our findings, the repeated MK-801 model could be a pathophysiological model which can provide an insight into the transition from first-episode to chronic stage. This is first time to investigate effects of repeated MK-801 using high-field in vivo 1H MRS. We expect our findings can contribute to combining previous diverging results into one pathophysiological interpretation, which can postulate the origin of diverging results to the progression of schizophrenia.

  16. SU-F-I-67: Neurometabolic Effect Induced by Repeated Exposure to Dizocilpine On Prefrontal Cortex of Schizophrenic Animal Model Using In Vivo Proton Magnetic Resonance Spectroscopy at 9.4 T

    International Nuclear Information System (INIS)

    Yoo, C-H; Lim, S-I; Song, K-H; Choe, B-Y; Woo, D-C

    2016-01-01

    Purpose: Repeated exposure of dizocilpine (MK-801) can provide a pathophysiological model for progressive development of schizophrenia. In vivo proton magnetic resonance spectroscopy ("1H MRS) was widely used for non-invasive measurement of neurometabolites, and assessment of disease-induced neurometabolic alterations. The purpose of this study was to investigate neurometabolic alteration in prefrontal cortex (PFC) with respect to progression (from first-episode to chronic stage) of schizophrenia by using in vivo "1H MRS. Methods: We used high-field "1H MRS to investigate the neurometabolic alteration in the PFC region of the rats (N = 13) by comparing before and after 6 day of MK-801 (0.5 mg/kg) treatment. A point-resolved spectroscopy (PRESS) sequence was used to obtain spectra in a 22.5 µL of volume of interest carefully located in PFC region with parameters like follow; repetition time, 5000ms; echo time (TE), 13.4 ms; averages = 256. Another experiment group (N = 11) were conducted behavior test by recording the behavior for 20 min. Results: All the rats showed hyperlocomotion, stereotyped behaviors before initiation of MRS. Significantly increased level (N = 7, p < 0.05) of N-acetylasrparate (NAA), glutamate (Glu), taurine and decreased level (N = 6, p < 0.05) of NAA, Glu and phosphocreatine were observed between baseline and day 6. Both metabolic alterations are consistent with results of first-episode and chronic schizophrenia respectively. Conclusion: From our findings, the repeated MK-801 model could be a pathophysiological model which can provide an insight into the transition from first-episode to chronic stage. This is first time to investigate effects of repeated MK-801 using high-field in vivo 1H MRS. We expect our findings can contribute to combining previous diverging results into one pathophysiological interpretation, which can postulate the origin of diverging results to the progression of schizophrenia.

  17. Single and repeated GnRH agonist stimulation tests compared with basal markers of ovarian reserve in the prediction of outcome in IVF

    NARCIS (Netherlands)

    Hendriks, D.J.; Broekmans, F.J.M.; Bancsi, L.F.J.M.M.; Looman, C.W.N.; Jong, F.H. de; Velde, E.R. te

    Purpose: To study the value of a single or repeated GnRH agonist stimulation test (GAST) in predicting outcome in IVF compared to basal ovarian reserve tests. Methods: A total of 57 women was included. In a cycle prior to the IVF treatment, on day 3, an antral follicle count (AFC) was performed

  18. Effects of different base agents on prediction of skin irritation by sodium lauryl sulfate using patch testing and repeated application test.

    Science.gov (United States)

    Horita, Kotomi; Horita, Daisuke; Tomita, Hiroyuki; Yasoshima, Mitsue; Yagami, Akiko; Matsunaga, Kayoko

    2017-05-01

    Animal testing for cosmetics was banned in the European Union (EU) in 2013; therefore, human tests to predict and ensure skin safety such as the patch test or usage test are now in demand in Japan as well as in the EU. In order to investigate the effects of different bases on the findings of tests to predict skin irritation, we performed patch testing (PT) and the repeated application test (RAT) using sodium lauryl sulfate (SLS), a well-known irritant, dissolved in 6 different base agents to examine the effects of these bases on skin irritation by SLS. The bases for PT were distilled water, 50% ethanol, 100% ethanol, a gel containing 50% ethanol, white petrolatum, and hydrophilic cream. The concentrations of SLS were 0.2% and 0.5%. Twelve different base combinations were applied to the normal back skin of 19 individuals for 24h. RAT was performed with distilled water, 50% ethanol, 100% ethanol, a gel containing 50% ethanol, white petrolatum, and hydrophilic cream containing SLS at concentrations of 0.2%, 2%, and 5%, being applied to the arms of the same PT subjects. The test preparation of each base was applied at the same site, with 0.2% SLS being used in the first week, 2% SLS in the following week, and 5% SLS in the final week. The results of PT revealed that skin irritation scores varied when SLS at the same concentration was dissolved in a different base. The results of RAT showed that although skin irritation appeared with every base at a concentration of 5%, the positive rate was approximately the same. In conclusion, our results suggest that skin irritation elicited in PT depends on the base, while in RAT, it does not depend on the type of base employed. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. HESI pilot project: Testing a qualitative approach for incorporating exposure into alternatives assessment

    DEFF Research Database (Denmark)

    Greggs, Bill; Arnold, Scott; Burns, Thomas J.

    -quantitative exposure assessment on the alternatives being considered. This talk will demonstrate an approach for including chemical and product exposure information in a qualitative AA comparison. Starting from existing hazard AAs, a series of four exposure examples were examined to test the concept, to understand...

  20. A step-by-step introduction to vegetables at the beginning of complementary feeding. The effects of early and repeated exposure.

    Science.gov (United States)

    Hetherington, Marion M; Schwartz, C; Madrelle, J; Croden, F; Nekitsing, C; Vereijken, C M J L; Weenen, H

    2015-01-01

    Breastfeeding (BF) is associated with willingness to accept vegetables. This may be due to the variety of flavours delivered via breast milk. Some mothers add vegetables to milk during complementary feeding (CF) to enhance acceptance. The present study tested a step-by-step exposure to vegetables in milk then rice during CF, on intake and liking of vegetables. Just before CF, enrolled mothers were randomised to an intervention (IG, n = 18; 6 BF) or control group (CG, n = 18; 6 BF). IG infants received 12 daily exposures to vegetable puree added to milk (days 1-12), then 12 × 2 daily exposures to vegetable puree added to rice at home (days 13-24). Plain milk and rice were given to CG. Then both received 11 daily exposures to vegetable puree. Intake was weighed and liking rated on days 25-26 and 33-35 after the start of CF in the laboratory, supplemented by the same data recorded at home. Vegetables were rotated daily (carrots, green beans, spinach, broccoli). Intake, liking and pace of eating were greater for IG than CG infants. Intake and liking of carrots were greater than green beans. However, at 6m then 18m follow up, vegetable (carrot > green beans) but not group differences were observed. Mothers reported appreciation of the structure and guidance of this systematic approach. Early exposure to vegetables in a step-by-step method could be included in CF guidelines and longer term benefits assessed by extending the exposure period. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. The Effects of a Single Whole-Body Cryotherapy Exposure on Physiological, Performance, and Perceptual Responses of Professional Academy Soccer Players After Repeated Sprint Exercise.

    Science.gov (United States)

    Russell, Mark; Birch, Jack; Love, Thomas; Cook, Christian J; Bracken, Richard M; Taylor, Tom; Swift, Eamon; Cockburn, Emma; Finn, Charlie; Cunningham, Daniel; Wilson, Laura; Kilduff, Liam P

    2017-02-01

    Russell, M, Birch, J, Love, T, Cook, CJ, Bracken, RM, Taylor, T, Swift, E, Cockburn, E, Finn, C, Cunningham, D, Wilson, L, and Kilduff, LP. The effects of a single whole-body cryotherapy exposure on physiological, performance, and perceptual responses of professional academy soccer players after repeated sprint exercise. J Strength Cond Res 31(2): 415-421, 2017-In professional youth soccer players, the physiological, performance, and perceptual effects of a single whole-body cryotherapy (WBC) session performed shortly after repeated sprint exercise were investigated. In a randomized, counterbalanced, and crossover design, 14 habituated English Premier League academy soccer players performed 15 × 30 m sprints (each followed by a 10 m forced deceleration) on 2 occasions. Within 20 minutes of exercise cessation, players entered a WBC chamber (Cryo: 30 seconds at -60° C, 120 seconds at -135° C) or remained seated (Con) indoors in temperate conditions (∼25° C). Blood and saliva samples, peak power output (countermovement jump), and perceptual indices of recovery and soreness were assessed pre-exercise and immediately, 2-hour and 24-hour postexercise. When compared with Con, a greater testosterone response was observed at 2-hour (+32.5 ± 32.3 pg·ml, +21%) and 24-hour (+50.4 ± 48.9 pg·ml, +28%) postexercise (both P = 0.002) in Cryo (trial × treatment interaction: P = 0.001). No between-trial differences were observed for other salivary (cortisol and testosterone/cortisol ratio), blood (lactate and creatine kinase), performance (peak power output), or perceptual (recovery or soreness) markers (all trial × treatment interactions: P > 0.05); all of which were influenced by exercise (time effects: all P ≤ 0.05). A single session of WBC performed within 20 minutes of repeated sprint exercise elevated testosterone concentrations for 24 hours but did not affect any other performance, physiological, or perceptual measurements taken. Although unclear, WBC may be

  2. Repeated Gestational Exposure of Mice to Chlorpyrifos Oxon Is Associated with Paraoxonase 1 (PON1) Modulated Effects in Maternal and Fetal Tissues

    Science.gov (United States)

    Co, Aila L.; Hay, Ariel M.; MacDonald, James W.; Bammler, Theo K.; Farin, Federico M.; Costa, Lucio G.; Furlong, Clement E.

    2014-01-01

    Chlorpyrifos oxon (CPO), the toxic metabolite of the organophosphorus (OP) insecticide chlorpyrifos, causes developmental neurotoxicity in humans and rodents. CPO is hydrolyzed by paraoxonase-1 (PON1), with protection determined by PON1 levels and the human Q192R polymorphism. To examine how the Q192R polymorphism influences fetal toxicity associated with gestational CPO exposure, we measured enzyme inhibition and fetal-brain gene expression in wild-type (PON1+/+), PON1-knockout (PON1−/−), and tgHuPON1R192 and tgHuPON1Q192 transgenic mice. Pregnant mice exposed dermally to 0, 0.50, 0.75, or 0.85 mg/kg/d CPO from gestational day (GD) 6 through 17 were sacrificed on GD18. Biomarkers of CPO exposure inhibited in maternal tissues included brain acetylcholinesterase (AChE), red blood cell acylpeptide hydrolase (APH), and plasma butyrylcholinesterase (BChE) and carboxylesterase (CES). Fetal plasma BChE was inhibited in PON1−/− and tgHuPON1Q192, but not PON1+/+ or tgHuPON1R192 mice. Fetal brain AChE and plasma CES were inhibited in PON1−/− mice, but not in other genotypes. Weighted gene co-expression network analysis identified five gene modules based on clustering of the correlations among their fetal-brain expression values, allowing for correlation of module membership with the phenotypic data on enzyme inhibition. One module that correlated highly with maternal brain AChE activity had a large representation of homeobox genes. Gene set enrichment analysis revealed multiple gene sets affected by gestational CPO exposure in tgHuPON1Q192 but not tgHuPON1R192 mice, including gene sets involved in protein export, lipid metabolism, and neurotransmission. These data indicate that maternal PON1 status modulates the effects of repeated gestational CPO exposure on fetal-brain gene expression and on inhibition of both maternal and fetal biomarker enzymes. PMID:25070982

  3. Repeated exposure to antibiotics in infancy: a predisposing factor for juvenile idiopathic arthritis or a sign of this group's greater susceptibility to infections?

    Science.gov (United States)

    Arvonen, Miika; Virta, Lauri J; Pokka, Tytti; Kröger, Liisa; Vähäsalo, Paula

    2015-03-01

    Previous exposure to antibiotics has been associated with the pathogenesis of several autoimmune diseases. Our objective was to explore whether childhood exposure to antibiotics would be associated with the risk of developing juvenile idiopathic arthritis (JIA). The material was collected from national registers containing all children born in 2000-2010 in Finland and diagnosed with JIA by the end of December 2012 (n = 1298) and appropriate controls (n = 5179) matched for age, sex, and place of birth. All purchases of antibiotics were collected from birth until the index date (i.e., the date of special reimbursement for JIA medications). A conditional logistic regression was performed to evaluate the association between the exposure to antibiotics and the risk of JIA. The risk of JIA increased with the number of antibiotic purchases from birth to the index date: for ≥ 1 purchases versus none, OR 1.6, 95% CI 1.3-1.9 with an upward trend in OR (p Antibiotic groups lincosamides and cephalosporins showed the strongest association with JIA (OR 6.6, 95% CI 3.7-11.7, and OR 1.6, 95% CI 1.4-1.8, respectively). Overall exposure to antibiotics before 2 years of age was associated with an increased risk of JIA (OR 1.4, 95% CI 1.2-1.6), with the trend test of OR (p antibiotics may predispose individuals to develop JIA. Alternatively, the apparent association may reflect shared susceptibility to infections and JIA.

  4. The Queensland study of Melanoma: Environmental and Genetic Associations (Q-MEGA). Study design, baseline characteristics, and repeatability of phenotype and sun exposure measures

    Science.gov (United States)

    Baxter, Amanda J.; Hughes, Maria Celia; Kvaskoff, Marina; Siskind, Victor; Shekar, Sri; Aitken, Joanne F.; Green, Adele C.; Duffy, David L.; Hayward, Nicholas K.; Martin, Nicholas G.; Whiteman, David C.

    2013-01-01

    Cutaneous malignant melanoma (CMM) is a major health issue in Queensland, Australia which has the world’s highest incidence. Recent molecular and epidemiologic studies suggest that CMM arises through multiple etiological pathways involving gene-environment interactions. Understanding the potential mechanisms leading to CMM requires larger studies than those previously conducted. This article describes the design and baseline characteristics of Q-MEGA, the Queensland study of Melanoma: Environmental and Genetic Associations, which followed-up four population-based samples of CMM patients in Queensland, including children, adolescents, men aged over 50, and a large sample of adult cases and their families, including twins. Q-MEGA aims to investigate the roles of genetic and environmental factors, and their interaction, in the etiology of melanoma. 3,471 participants took part in the follow-up study and were administered a computer-assisted telephone interview in 2002–2005. Updated data on environmental and phenotypic risk factors, and 2,777 blood samples were collected from interviewed participants as well as a subset of relatives. This study provides a large and well-described population-based sample of CMM cases with follow-up data. Characteristics of the cases and repeatability of sun exposure and phenotype measures between the baseline and the follow-up surveys, from six to 17 years later, are also described. PMID:18361720

  5. Patterns and predictors of repeat fecal immunochemical and occult blood test screening in four large health care systems in the United States.

    Science.gov (United States)

    Singal, Amit G; Corley, Douglas A; Kamineni, Aruna; Garcia, Michael; Zheng, Yingye; Doria-Rose, Paul V; Quinn, Virginia P; Jensen, Christopher D; Chubak, Jessica; Tiro, Jasmin; Doubeni, Chyke A; Ghai, Nirupa R; Skinner, Celette Sugg; Wernli, Karen; Halm, Ethan A

    2018-02-27

    Effectiveness of fecal occult blood test (FOBT) for colorectal cancer (CRC) screening depends on annual testing, but little is known about patterns of repeat stool-based screening within different settings. Our study's objective was to characterize screening patterns and identify factors associated with repeat screening among patients who completed an index guaiac FOBT (gFOBT) or fecal immunochemical test (FIT). We performed a multi-center retrospective cohort study among people who completed a FOBT between January 2010 and December 2011 to characterize repeat screening patterns over the subsequent 3 years. We studied at 4 large health care delivery systems in the United States. Logistic regression analyses were used to identify factors associated with repeat screening patterns. We included individuals aged 50-71 years who completed an index FOBT and had at least 3 years of follow-up. We excluded people with a history of CRC, colonoscopy within 10 years or flexible sigmoidoscopy within 5 years before the index test, or positive index stool test. Consistent screening was defined as repeat FOBT within every 15 months and inconsistent screening as repeat testing at least once during follow-up but less than consistent screening. Among 959,857 eligible patients who completed an index FIT or gFOBT, 344,103 had three years of follow-up and met inclusion criteria. Of these, 46.6% had consistent screening, 43.4% inconsistent screening, and 10% had no repeat screening during follow-up. Screening patterns varied substantially across healthcare systems, with consistent screening proportions ranging from 1 to 54.3% and no repeat screening proportions ranging from 6.9 to 42.8%. Higher consistent screening proportions were observed in health systems with screening outreach and in-reach programs, whereas the safety-net health system, which uses opportunistic clinic-based screening, had the lowest consistent screening. Consistent screening increased with older age but was less

  6. Accelerated atmospheric corrosion testing using a cyclic wet/dry exposure test

    International Nuclear Information System (INIS)

    Lyon, S.B.; Thompson, G.E.; Johnson, J.E.; Wood, G.C.

    1989-01-01

    Aluminum corrosion is important in overhead electrical conductors constructed from aluminum wire centrally reinforced by galvanized steel strands. Inspection of conductor after long service has implicated rubber bushing material, on the outside, and the galvanized strands, on the inside, as providing potential galvanic sites for the initiation of rapid aluminum corrosion. Therefore, the galvanic corrosion of aluminum in contact with graphite-loaded neoprene rubber, hot-dip galvanized steel and steel was assessed in a cyclic wet/dry exposure test using mixed-salts spray solutions containing appropriate ratios of sulfate and chloride ion. Aluminum was found to corrode at between 3 to 6 times its uncoupled rate when associated with the rubber material. While the eta-phase, relatively pure Zn, galvanized layer remained intact, galvanic corrosion of aluminum was slow. However, on exposure of the zeta-phase, Zn/Fe intermetallic layer, aluminum corroded about 35 times faster than expected in a solution with a high level of Cl - ion. The importance of these data to conductor lifetime is discussed

  7. The National Environmental Respiratory Center (NERC) experiment in multi-pollutant air quality health research: IV. Vascular effects of repeated inhalation exposure to a mixture of five inorganic gases.

    Science.gov (United States)

    Mauderly, J L; Kracko, D; Brower, J; Doyle-Eisele, M; McDonald, J D; Lund, A K; Seilkop, S K

    2014-09-01

    An experiment was conducted to test the hypothesis that a mixture of five inorganic gases could reproduce certain central vascular effects of repeated inhalation exposure of apolipoprotein E-deficient mice to diesel or gasoline engine exhaust. The hypothesis resulted from preceding multiple additive regression tree (MART) analysis of a composition-concentration-response database of mice exposed by inhalation to the exhausts and other complex mixtures. The five gases were the predictors most important to MART models best fitting the vascular responses. Mice on high-fat diet were exposed 6 h/d, 7 d/week for 50 d to clean air or a mixture containing 30.6 ppm CO, 20.5 ppm NO, 1.4 ppm NO₂, 0.5 ppm SO₂, and 2.0 ppm NH₃ in air. The gas concentrations were below the maxima in the preceding studies but in the range of those in exhaust exposure levels that caused significant effects. Five indicators of stress and pro-atherosclerotic responses were measured in aortic tissue. The exposure increased all five response indicators, with the magnitude of effect and statistical significance varying among the indicators and depending on inclusion or exclusion of an apparent outlying control. With the outlier excluded, three responses approximated predicted values and two fell below predictions. The results generally supported evidence that the five gases drove the effects of exhaust, and thus supported the potential of the MART approach for identifying putative causal components of complex mixtures.

  8. Study of a 13-weeks, Repeated, Intramuscular Dose, Toxicity Test of Sweet Bee Venom in Sprague-Dawley Rats

    Directory of Open Access Journals (Sweden)

    Hyunmin Kang

    2014-06-01

    Full Text Available Objectives:This study was performed to analyze a 13-week repeated dose toxicity test of Sweet Bee Venom (SBV extracted from bee venom and administered in Sprague-Dawley (SD rats. Methods:Male and female 5-week-old SD rats were treated once daily with SBV (high-dosage group: 0.28 mg/kg; medium-dosage group: 0.14 mg/kg; or low-dosage group: 0.07 mg/kg for 13 weeks. Normal saline was administered to the control group in a similar manner (0.2 mL/kg. We conducted clinical observations, body weight measurements, ophthalmic examinations, urinalyses, hematology and biochemistry tests, and histological observations using hematoxylin and eosin (H&E staining to identify any abnormalities caused by the SBV treatment. Results:During this study, no mortality was observed in any of the experimental groups. Hyperemia and a movement disorder were observed around the area of in all groups that received SBV treatment, with a higher occurrence in rats treated with a higher dosage. Male rats receiving in the high-dosage group showed a significant decrease in weight during the treatment period. Compared to the control group, no significant changes in the ophthalmic parameters, the urine analyses, the complete blood cell count (CBC, and the biochemistry in the groups treated with SBV. Compared to the control group, some changes in organ weights were observed in the medium-and the high-dosage groups, but the low-dosage group showed no significant changes. Histological examination of thigh muscle indicated cell infiltration, inflammation, degeneration, and necrosis of muscle fiber, as well as fibrosis, in both the medium- and the high-dosage groups. Fatty liver change was observed in the periportal area of rats receiving medium and high dosages of SBV. No other organ abnormalities were observed. Conclusion:Our findings suggest that the No Observed Adverse Effect Level (NOAEL of SBV is approximately 0.07 mg/kg in male and female SD rats.

  9. Study on the correlation between long-term exposure tests and accelerated corrosion tests by the combined damage of salts

    International Nuclear Information System (INIS)

    Park, Sang Soon; Lee, Min Woo

    2014-01-01

    Interest in the durability assessment and structural performance has increased according to an increase of concrete structures in salt damage environment recent years. Reliable way ensuring the most accelerated corrosion test is a method of performing the rebar corrosion monitoring as exposed directly to the marine test site exposure. However, long-term exposure test has a disadvantage because of a long period of time. Therefore, many studies on reinforced concrete in salt damage environments have been developed as alternatives to replace this. However, accelerated corrosion test is appropriate to evaluate the critical chlorine concentration in the short term, but only accelerated test method, is not easy to get correct answer. Accuracy of correlation acceleration test depends on the period of the degree of exposure environments. Therefore, in this study, depending on the concrete mix material, by the test was performed on the basis of the composite degradation of the salt damage, and investigate the difference of corrosion initiation time of the rebar, and indoor corrosion time of the structure, of the marine environment of the actual environments were investigated. The correlation coefficient was derived in the experiment. Long-term exposure test was actually conducted in consideration of the exposure conditions submerged zone, splash zone and tidal zone. The accelerated corrosion tests were carried out by immersion conditions, and by the combined deterioration due to the carbonation and accelerated corrosion due to wet and dry condition

  10. Environmental Exposure and Accelerated Testing of Rubber-to-Metal Vulcanized Bonded Assemblies

    Science.gov (United States)

    1974-11-01

    btadiene/acrylonitrile ( NBR ) rubber -to-metat -. canized bonded assemblies at the two exposure sites are shown in Table 5. After exposure for one year...AD-A0-17 368 EN~VIRONMENTAL EXPOSURE AND ACCELERATED TESTING OF RUBBER -TO-METAL VULCANIZED BONDED ASSEMBLIES John A. WilliamsI Rock Island Arseital...COMMERCE 325116 1AD R-TR-75-013 ENViRONMENTAL EXPOSURE AND ACCELERATED TESTING OF RUBBER -TO-METAL VULCANIZED BONDED ASSEMBLIES by __ John A. Williams

  11. Prospective study of leptospirosis transmission in an urban slum community: role of poor environment in repeated exposures to the Leptospira agent.

    Science.gov (United States)

    Felzemburgh, Ridalva D M; Ribeiro, Guilherme S; Costa, Federico; Reis, Renato B; Hagan, José E; Melendez, Astrid X T O; Fraga, Deborah; Santana, Francisco S; Mohr, Sharif; dos Santos, Balbino L; Silva, Adriano Q; Santos, Andréia C; Ravines, Romy R; Tassinari, Wagner S; Carvalho, Marília S; Reis, Mitermayer G; Ko, Albert I

    2014-01-01

    Leptospirosis has emerged as an urban health problem as slum settlements have rapidly spread worldwide and created conditions for rat-borne transmission. Prospective studies have not been performed to determine the disease burden, identify risk factors for infection and provide information needed to guide interventions in these marginalized communities. We enrolled and followed a cohort of 2,003 residents from a slum community in the city of Salvador, Brazil. Baseline and one-year serosurveys were performed to identify primary and secondary Leptospira infections, defined as respectively, seroconversion and four-fold rise in microscopic agglutination titers. We used multinomial logistic regression models to evaluate risk exposures for acquiring primary and secondary infection. A total of 51 Leptospira infections were identified among 1,585 (79%) participants who completed the one-year follow-up protocol. The crude infection rate was 37.8 per 1,000 person-years. The secondary infection rate was 2.3 times higher than that of primary infection rate (71.7 and 31.1 infections per 1,000 person-years, respectively). Male gender (OR 2.88; 95% CI 1.40-5.91) and lower per capita household income (OR 0.54; 95% CI, 0.30-0.98 for an increase of $1 per person per day) were independent risk factors for primary infection. In contrast, the 15-34 year age group (OR 10.82, 95% CI 1.38-85.08), and proximity of residence to an open sewer (OR 0.95; 0.91-0.99 for an increase of 1 m distance) were significant risk factors for secondary infection. This study found that slum residents had high risk (>3% per year) for acquiring a Leptospira infection. Re-infection is a frequent event and occurs in regions of slum settlements that are in proximity to open sewers. Effective prevention of leptospirosis will therefore require interventions that address the infrastructure deficiencies that contribute to repeated exposures among slum inhabitants.

  12. Is one trial enough for repeated testing? Same-day assessments of walking, mobility and fine hand use in people with myotonic dystrophy type 1.

    Science.gov (United States)

    Kierkegaard, Marie; Petitclerc, Emilie; Hébert, Luc J; Gagnon, Cynthia

    2017-02-01

    Performance-based assessments of physical function are essential in people with myotonic dystrophy type 1 (DM1) to monitor disease progression and evaluate interventions. Commonly used are the six-minute walk test, the 10 m-walk test, the timed up-and-go test, the timed-stands test, grip strength tests and the nine-hole peg test. The number of trials needed on a same-day test occasion and whether the first, best or average of trials should be reported as result is unknown. Thus, the aim was to describe and explore differences between trials in these measures of walking, mobility and fine hand use in 70 adults with DM1. Three trials were performed for each test except for the six-minute walk test where two trials were allowed. There were statistical significant differences over trials in all tests except for the 10 m-walk test and grip strength tests. Pair-wise comparisons showed that the second and third trials were in general better than the first, although effect sizes were small. At which trial the individuals performed their best differed between individuals and tests. People with severe muscular impairment had difficulties to perform repeated trials. Intraclass correlation coefficients were all high in analyses exploring how to report results. The conclusion and clinical implication is that, for a same-day test occasion, one trial is sufficient for the 10 m-walk test and grip strength tests, and that repeated trials should be allowed in the timed up-and-go test, timed-stands test and nine-hole peg tests. We recommend that two trials are performed for these latter tests as such a protocol could accommodate people with various levels of impairments and physical limitations. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Preferential induction of the AhR gene battery in HepaRG cells after a single or repeated exposure to heterocyclic aromatic amines

    International Nuclear Information System (INIS)

    Dumont, Julie; Josse, Rozenn; Lambert, Carine; Antherieu, Sebastien; Laurent, Veronique; Loyer, Pascal; Robin, Marie-Anne; Guillouzo, Andre

    2010-01-01

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) are two of the most common heterocyclic aromatic amines (HAA) produced during cooking of meat, fish and poultry. Both HAA produce different tumor profiles in rodents and are suspected to be carcinogenic in humans. In order to better understand the molecular basis of HAA toxicity, we have analyzed gene expression profiles in the metabolically competent human HepaRG cells using pangenomic oligonucleotide microarrays, after either a single (24-h) or a repeated (28-day) exposure to 10 μM PhIP or MeIQx. The most responsive genes to both HAA were downstream targets of the arylhydrocarbon receptor (AhR): CYP1A1 and CYP1A2 after both time points and CYP1B1 and ALDH3A1 after 28 days. Accordingly, CYP1A1/1A2 induction in HAA-treated HepaRG cells was prevented by chemical inhibition or small interference RNA-mediated down-regulation of the AhR. Consistently, HAA induced activity of the CYP1A1 promoter, which contains a consensus AhR-related xenobiotic-responsive element (XRE). In addition, several other genes exhibited both time-dependent and compound-specific expression changes with, however, a smaller magnitude than previously reported for the prototypical AhR target genes. These changes concerned genes mainly related to cell growth and proliferation, apoptosis, and cancer. In conclusion, these results identify the AhR gene battery as the preferential target of PhIP and MeIQx in HepaRG cells and further support the hypothesis that intake of HAA in diet might increase human cancer risk.

  14. Repeated in vivo exposure of cocaine induces long-lasting synaptic plasticity in hypocretin/orexin-producing neurons in the lateral hypothalamus in mice.

    Science.gov (United States)

    Rao, Yan; Mineur, Yann S; Gan, Geliang; Wang, Alex Hanxiang; Liu, Zhong-Wu; Wu, Xinyuan; Suyama, Shigetomo; de Lecea, Luis; Horvath, Tamas L; Picciotto, Marina R; Gao, Xiao-Bing

    2013-04-01

    Hypocretin (orexin), a neuropeptide synthesized exclusively in the perifornical/lateral hypothalamus, is critical for drug seeking and relapse, but it is not clear how the circuitry centred on hypocretin-producing neurons (hypocretin neurons) is modified by drugs of abuse and how changes in this circuit might alter behaviours related to drug addiction. In this study, we show that repeated, but not single, in vivo cocaine administration leads to a long-lasting, experience-dependent potentiation of glutamatergic synapses on hypocretin neurons in mice following a cocaine-conditioned place preference (CPP) protocol. The synaptic potentiation occurs postsynaptically and probably involves up-regulation of AMPA-type glutamate receptors on hypocretin neurons. Phosphorylation of cAMP response element-binding protein (CREB) is also significantly increased in hypocretin neurons in cocaine-treated animals, suggesting that CREB-mediated pathways may contribute to synaptic potentiation in these cells. Furthermore, the potentiation of synaptic efficacy in hypocretin neurons persists during cocaine withdrawal, but reverses to baseline levels after prolonged abstinence. Finally, the induction of long-term potentiation (LTP) triggered by a high-frequency stimulation is facilitated in hypocretin neurons in cocaine-treated mice, suggesting that long-lasting changes in synapses onto hypocretin neurons would probably be further potentiated by other stimuli (such as concurrent environmental cues) paired with the drug. In summary, we show here that hypocretin neurons undergo experience-dependent synaptic potentiation that is distinct from that reported in other reward systems, such as the ventral tegmental area, following exposure to cocaine. These findings support the idea that the hypocretin system is important for behavioural changes associated with cocaine administration in animals and humans.

  15. Evidence-based severity assessment: Impact of repeated versus single open-field testing on welfare in C57BL/6J mice.

    Science.gov (United States)

    Bodden, Carina; Siestrup, Sophie; Palme, Rupert; Kaiser, Sylvia; Sachser, Norbert; Richter, S Helene

    2018-01-15

    According to current guidelines on animal experiments, a prospective assessment of the severity of each procedure is mandatory. However, so far, the classification of procedures into different severity categories mainly relies on theoretic considerations, since it is not entirely clear which of the various procedures compromise the welfare of animals, or, to what extent. Against this background, a systematic empirical investigation of the impact of each procedure, including behavioral testing, seems essential. Therefore, the present study was designed to elucidate the effects of repeated versus single testing on mouse welfare, using one of the most commonly used paradigms for behavioral phenotyping in behavioral neuroscience, the open-field test. In an independent groups design, laboratory mice (Mus musculus f. domestica) experienced either repeated, single, or no open-field testing - procedures that are assigned to different severity categories. Interestingly, testing experiences did not affect fecal corticosterone metabolites, body weights, elevated plus-maze or home cage behavior differentially. Thus, with respect to the assessed endocrinological, physical, and behavioral outcome measures, no signs of compromised welfare could be detected in mice that were tested in the open-field repeatedly, once, or, not at all. These findings challenge current classification guidelines and may, furthermore, stimulate systematic research on the severity of single procedures involving living animals. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Lead exposure and the 2010 achievement test scores of children in New York counties

    Directory of Open Access Journals (Sweden)

    Strayhorn Jillian C

    2012-01-01

    Full Text Available Abstract Background Lead is toxic to cognitive and behavioral functioning in children even at levels well below those producing physical symptoms. Continuing efforts in the U.S. since about the 1970s to reduce lead exposure in children have dramatically reduced the incidence of elevated blood lead levels (with elevated levels defined by the current U.S. Centers for Disease Control threshold of 10 μg/dl. The current study examines how much lead toxicity continues to impair the academic achievement of children of New York State, using 2010 test data. Methods This study relies on three sets of data published for the 57 New York counties outside New York City: school achievement data from the New York State Department of Education, data on incidence of elevated blood lead levels from the New York State Department of Health, and data on income from the U.S. Census Bureau. We studied third grade and eighth grade test scores in English Language Arts and mathematics. Using the county as the unit of analysis, we computed bivariate correlations and regression coefficients, with percent of children achieving at the lowest reported level as the dependent variable and the percent of preschoolers in the county with elevated blood lead levels as the independent variable. Then we repeated those analyses using partial correlations to control for possible confounding effects of family income, and using multiple regressions with income included. Results The bivariate correlations between incidence of elevated lead and number of children in the lowest achievement group ranged between 0.38 and 0.47. The partial correlations ranged from 0.29 to 0.40. The regression coefficients, both bivariate and partial (both estimating the increase in percent of children in the lowest achievement group for every percent increase in the children with elevated blood lead levels, ranged from 0.52 to 1.31. All regression coefficients, when rounded to the nearest integer, were

  17. Repeated testing improves achievement in a blended learning approach for risk competence training of medical students: results of a randomized controlled trial.

    Science.gov (United States)

    Spreckelsen, C; Juenger, J

    2017-09-26

    Adequate estimation and communication of risks is a critical competence of physicians. Due to an evident lack of these competences, effective training addressing risk competence during medical education is needed. Test-enhanced learning has been shown to produce marked effects on achievements. This study aimed to investigate the effect of repeated tests implemented on top of a blended learning program for risk competence. We introduced a blended-learning curriculum for risk estimation and risk communication based on a set of operationalized learning objectives, which was integrated into a mandatory course "Evidence-based Medicine" for third-year students. A randomized controlled trial addressed the effect of repeated testing on achievement as measured by the students' pre- and post-training score (nine multiple-choice items). Basic numeracy and statistical literacy were assessed at baseline. Analysis relied on descriptive statistics (histograms, box plots, scatter plots, and summary of descriptive measures), bootstrapped confidence intervals, analysis of covariance (ANCOVA), and effect sizes (Cohen's d, r) based on adjusted means and standard deviations. All of the 114 students enrolled in the course consented to take part in the study and were assigned to either the intervention or control group (both: n = 57) by balanced randomization. Five participants dropped out due to non-compliance (control: 4, intervention: 1). Both groups profited considerably from the program in general (Cohen's d for overall pre vs. post scores: 2.61). Repeated testing yielded an additional positive effect: while the covariate (baseline score) exhibits no relation to the post-intervention score, F(1, 106) = 2.88, p > .05, there was a significant effect of the intervention (repeated tests scenario) on learning achievement, F(1106) = 12.72, p blended learning approach can be improved significantly by implementing a test-enhanced learning design, namely repeated testing. As

  18. What Is the Role of Paired Rapid Plasma Reagin Testing (Simultaneous Testing of Acute and Convalescent Samples) in the Diagnosis of Repeat Syphilis and the Follow-up of Syphilis?

    Science.gov (United States)

    Kenyon, Chris R; Osbak, Kara Krista; Van Esbroek, Marjan; Lynen, Lutgarde; Crucitti, Tania

    2018-01-01

    Repeat syphilis is playing an increasing role in syphilis transmission in several populations. The assessment of repeat syphilis and response to treatment depends on accurately measuring intraindividual changes in non-treponemal tests. For a 0- to 6-month delta rapid plasma reagin (RPR) to be determined by routine individual RPR testing, samples are tested 6 months apart with differences in reagent batches, environmental conditions, and observers all leading to measurement errors. We hypothesized that conducting paired RPR testing (simultaneous testing of acute and convalescent samples) would enable a more accurate determination of delta RPR compared with individual testing. A total of 120 study participants with a new diagnosis of syphilis were followed up at 0, 3, 6, 9, 12, 18, and 24 months, with RPR testing performed via individual testing at each study visit and at any suspected repeat syphilis. Rapid plasma reagin paired testing was performed on samples from 0 and 6 months and at any suspected repeat syphilis. The quantitative agreement ±1 dilution among paired and individual testing was 97.2%. There was no difference in the proportion with serofast status at 6 months: 21 (19.4%) and 19 (17.6%) according to paired and individual testing, respectively (P = 0.726). There was no statistically significant difference between 0- and 6-month delta RPR as determined by paired and individual testing in predicting seroresponse at 12 months (86.1% and 91.6% agreement with 12-month serofast/nonserofast classification, respectively; P = 0.262). In our setting, individual testing performed equally well compared with paired testing. Follow-up of syphilis will remain onerous for the patient and the health care provider until new tests that can more accurately assess the response to therapy and repeat syphilis/treatment failure are developed.

  19. Test-retest repeatability of myocardial blood flow and infarct size using 11C-acetate micro-PET imaging in mice

    International Nuclear Information System (INIS)

    Croteau, Etienne; Renaud, Jennifer M.; McDonald, Matthew; Klein, Ran; DaSilva, Jean N.; Beanlands, Rob S.B.; DeKemp, Robert A.

    2015-01-01

    Global and regional responses of absolute myocardial blood flow index (iMBF) are used as surrogate markers to assess response to therapies in coronary artery disease. In this study, we assessed the test-retest repeatability of iMBF imaging, and the accuracy of infarct sizing in mice using 11 C-acetate PET. 11 C-Acetate cardiac PET images were acquired in healthy controls, endothelial nitric oxide synthase (eNOS) knockout transgenic mice, and mice after myocardial infarction (MI) to estimate global and regional iMBF, and myocardial infarct size compared to 18 F-FDG PET and ex-vivo histology results. Global test-retest iMBF values had good coefficients of repeatability (CR) in healthy mice, eNOS knockout mice and normally perfused regions in MI mice (CR = 1.6, 2.0 and 1.5 mL/min/g, respectively). Infarct size measured on 11 C-acetate iMBF images was also repeatable (CR = 17 %) and showed a good correlation with the infarct sizes found on 18 F-FDG PET and histopathology (r 2 > 0.77; p < 0.05). 11 C-Acetate micro-PET assessment of iMBF and infarct size is repeatable and suitable for serial investigation of coronary artery disease progression and therapy. (orig.)

  20. Test-retest repeatability of myocardial blood flow and infarct size using {sup 11}C-acetate micro-PET imaging in mice

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, Etienne; Renaud, Jennifer M.; McDonald, Matthew; Klein, Ran; DaSilva, Jean N.; Beanlands, Rob S.B.; DeKemp, Robert A. [University of Ottawa Heart Institute, National Cardiac PET Centre, Ottawa, Ontario (Canada)

    2015-09-15

    Global and regional responses of absolute myocardial blood flow index (iMBF) are used as surrogate markers to assess response to therapies in coronary artery disease. In this study, we assessed the test-retest repeatability of iMBF imaging, and the accuracy of infarct sizing in mice using {sup 11}C-acetate PET. {sup 11}C-Acetate cardiac PET images were acquired in healthy controls, endothelial nitric oxide synthase (eNOS) knockout transgenic mice, and mice after myocardial infarction (MI) to estimate global and regional iMBF, and myocardial infarct size compared to {sup 18}F-FDG PET and ex-vivo histology results. Global test-retest iMBF values had good coefficients of repeatability (CR) in healthy mice, eNOS knockout mice and normally perfused regions in MI mice (CR = 1.6, 2.0 and 1.5 mL/min/g, respectively). Infarct size measured on {sup 11}C-acetate iMBF images was also repeatable (CR = 17 %) and showed a good correlation with the infarct sizes found on {sup 18}F-FDG PET and histopathology (r{sup 2} > 0.77; p < 0.05). {sup 11}C-Acetate micro-PET assessment of iMBF and infarct size is repeatable and suitable for serial investigation of coronary artery disease progression and therapy. (orig.)

  1. Recommendations for analysis of repeated-measures designs: testing and correcting for sphericity and use of manova and mixed model analysis.

    Science.gov (United States)

    Armstrong, Richard A

    2017-09-01

    A common experimental design in ophthalmic research is the repeated-measures design in which at least one variable is a within-subject factor. This design is vulnerable to lack of 'sphericity' which assumes that the variances of the differences among all possible pairs of within-subject means are equal. Traditionally, this design has been analysed using a repeated-measures analysis of variance (RM-anova) but increasingly more complex methods such as multivariate anova (manova) and mixed model analysis (MMA) are being used. This article surveys current practice in the analysis of designs incorporating different factors in research articles published in three optometric journals, namely Ophthalmic and Physiological Optics (OPO), Optometry and Vision Science (OVS), and Clinical and Experimental Optometry (CXO), and provides advice to authors regarding the analysis of repeated-measures designs. Of the total sample of articles, 66% used a repeated-measures design. Of those articles using a repeated-measures design, 59% and 8% analysed the data using RM-anova or manova respectively and 33% used MMA. The use of MMA relative to RM-anova has increased significantly since 2009/10. A further search using terms to select those papers testing and correcting for sphericity ('Mauchly's test', 'Greenhouse-Geisser', 'Huynh and Feld') identified 66 articles, 62% of which were published from 2012 to the present. If the design is balanced without missing data then manova should be used rather than RM-anova as it gives better protection against lack of sphericity. If the design is unbalanced or with missing data then MMA is the method of choice. However, MMA is a more complex analysis and can be difficult to set up and run, and care should be taken first, to define appropriate models to be tested and second, to ensure that sample sizes are adequate. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

  2. Proactive behavior, but not inhibitory control, predicts repeated innovation by spotted hyenas tested with a multi-access box.

    Science.gov (United States)

    Johnson-Ulrich, Lily; Johnson-Ulrich, Zoe; Holekamp, Kay

    2018-05-01

    Innovation is widely linked to cognitive ability, brain size, and adaptation to novel conditions. However, successful innovation appears to be influenced by both cognitive factors, such as inhibitory control, and non-cognitive behavioral traits. We used a multi-access box (MAB) paradigm to measure repeated innovation, the number of unique innovations learned across trials, by 10 captive spotted hyenas (Crocuta crocuta). Spotted hyenas are highly innovative in captivity and also display striking variation in behavioral traits, making them good model organisms for examining the relationship between innovation and other behavioral traits. We measured persistence, motor diversity, motivation, activity, efficiency, inhibitory control, and neophobia demonstrated by hyenas while interacting with the MAB. We also independently assessed inhibitory control with a detour cylinder task. Most hyenas were able to solve the MAB at least once, but only four hyenas satisfied learning criteria for all four possible solutions. Interestingly, neither measure of inhibitory control predicted repeated innovation. Instead, repeated innovation was predicted by a proactive syndrome of behavioral traits that included high persistence, high motor diversity, high activity and low neophobia. Our results suggest that this proactive behavioral syndrome may be more important than inhibitory control for successful innovation with the MAB by members of this species.

  3. Repeatability of Cryogenic Multilayer Insulation

    Science.gov (United States)

    Johnson, W. L.; Vanderlaan, M.; Wood, J. J.; Rhys, N. O.; Guo, W.; Van Sciver, S.; Chato, D. J.

    2017-12-01

    Due to the variety of requirements across aerospace platforms, and one off projects, the repeatability of cryogenic multilayer insulation (MLI) has never been fully established. The objective of this test program is to provide a more basic understanding of the thermal performance repeatability of MLI systems that are applicable to large scale tanks. There are several different types of repeatability that can be accounted for: these include repeatability between identical blankets, repeatability of installation of the same blanket, and repeatability of a test apparatus. The focus of the work in this report is on the first two types of repeatability. Statistically, repeatability can mean many different things. In simplest form, it refers to the range of performance that a population exhibits and the average of the population. However, as more and more identical components are made (i.e. the population of concern grows), the simple range morphs into a standard deviation from an average performance. Initial repeatability testing on MLI blankets has been completed at Florida State University. Repeatability of five Glenn Research Center (GRC) provided coupons with 25 layers was shown to be +/- 8.4% whereas repeatability of repeatedly installing a single coupon was shown to be +/- 8.0%. A second group of 10 coupons has been fabricated by Yetispace and tested by Florida State University, the repeatability between coupons has been shown to be +/- 15-25%. Based on detailed statistical analysis, the data has been shown to be statistically significant.

  4. Multiple Maximum Exposure Rates in Computerized Adaptive Testing

    Science.gov (United States)

    Ramon Barrada, Juan; Veldkamp, Bernard P.; Olea, Julio

    2009-01-01

    Computerized adaptive testing is subject to security problems, as the item bank content remains operative over long periods and administration time is flexible for examinees. Spreading the content of a part of the item bank could lead to an overestimation of the examinees' trait level. The most common way of reducing this risk is to impose a…

  5. Subliminal mere exposure and explicit and implicit positive affective responses.

    Science.gov (United States)

    Hicks, Joshua A; King, Laura A

    2011-06-01

    Research suggests that repeated subliminal exposure to environmental stimuli enhances positive affective responses. To date, this research has primarily concentrated on the effects of repeated exposure on explicit measures of positive affect (PA). However, recent research suggests that repeated subliminal presentations may increase implicit PA as well. The present study tested this hypothesis. Participants were either subliminally primed with repeated presentations of the same stimuli or only exposed to each stimulus one time. Results confirmed predictions showing that repeated exposure to the same stimuli increased both explicit and implicit PA. Implications for the role of explicit and implicit PA in attitudinal judgements are discussed.

  6. Improvement of the CULTEX® exposure technology by radial distribution of the test aerosol.

    Science.gov (United States)

    Aufderheide, Michaela; Heller, Wolf-Dieter; Krischenowski, Olaf; Möhle, Niklas; Hochrainer, Dieter

    2017-07-05

    The exposure of cellular based systems cultivated on microporous membranes at the air-liquid interface (ALI) has been accepted as an appropriate approach to simulate the exposure of cells of the respiratory tract to native airborne substances. The efficiency of such an exposure procedure with regard to stability and reproducibility depends on the optimal design at the interface between the cellular test system and the exposure technique. The actual exposure systems favor the dynamic guidance of the airborne substances to the surface of the cells in specially designed exposure devices. Two module types, based on a linear or radial feed of the test atmosphere to the test system, were used for these studies. In our technical history, the development started with the linear designed version, the CULTEX ® glass modules, fulfilling basic requirements for running ALI exposure studies (Mohr and Durst, 2005). The instability in the distribution of different atmospheres to the cells caused us to create a new exposure module, characterized by a stable and reproducible radial guidance of the aerosol to the cells. The outcome was the CULTEX ® RFS (Mohr et al., 2010). In this study, we describe the differences between the two systems with regard to particle distribution and deposition clarifying the advantages and disadvantages of a radial to a linear aerosol distribution concept. Copyright © 2017 Elsevier GmbH. All rights reserved.

  7. Test-retest repeatability of strength capacity, aerobic power and pericranial tenderness of neck and shoulder muscles in children - relevant for tension-type headache

    Directory of Open Access Journals (Sweden)

    Tornøe B

    2013-08-01

    Full Text Available Birte Tornøe,1,2,5,6 Lars L Andersen,3 Jørgen H Skotte,3 Rigmor Jensen,4 Gunvor Gard,1 Liselotte Skov,2 Inger Hallström1 1Department of Health Sciences, Lund University, Scania, Sweden; 2Children's Headache Clinic, Department of Pediatrics, University of Copenhagen, Herlev Hospital, Herlev, Denmark; 3National Research Centre for the Working Environment, Copenhagen, Denmark; 4Danish Headache Center, Department of Neurology, University of Copenhagen, Glostrup Hospital, Glostrup, Denmark; 5Department of Physiotherapy and Occupational Therapy, University of Copenhagen, Glostrup Hospital, Glostrup, Denmark; 6Department of Physiotherapy, Medical Department, University of Copenhagen, Herlev Hospital, Herlev, Denmark Background: Frequent or chronic tension-type headache in children is a prevalent and debilitating condition for the child, often leading to medication overuse. To explore the relationship between physical factors and tension-type headache in children, the quality of repeated measures was examined. The aim of the present study was to determine the test-retest repeatability of parameters determining isometric neck and shoulder strength and stability, aerobic power, and pericranial tenderness in children. Methods: Twenty-five healthy children, 9 to 18 years of age, participated in test-retest procedures within a 1-week interval. A computerized padded force transducer was used for testing. The tests included the isometric maximal voluntary contraction and force steadiness of neck flexion and extension, and the isometric maximal voluntary contraction and rate of force of the dominant shoulder. Pericranial tenderness was recorded by means of standardized manual palpation, and a submaximal cycle ergometer test predicted maximal oxygen uptake (VO2 max. The measurements were evaluated in steps, using the intraclass correlation coefficient (ICC; changes in the mean between the two test occasions; the levels of agreement, visualized in Bland

  8. The preventive effect of vitamin C on the cellular and functional integrity of kidney cells in rats following repeated exposure to paraquat

    Directory of Open Access Journals (Sweden)

    Benjamin Nnamdi Okolonkwo

    2014-11-01

    Full Text Available Paraquat (PQ is a bipyridylium herbicide that is applied around trees in orchards and between crop rows to control broad-leaved and grassy weeds. Its oxidation results in the formation of superoxides which causes damage to cellular components. In this study, we determined the antioxidant effect vitamin C has on the cellular integrity of kidney function in rats following repeated exposure to PQ. Ninety-six male rats, grouped twelve rats per subgroup (A, Avit.c, B, Bvit.c, C, Cvit.c, D and Dvit.c were intraperitoneally injected with different sublethal increasing doses (0, 0, 2, 2, 4, 4, 6 and 6 mg/kg body weight of PQ respectively on biweekly (14 days intervals over a period of three months (84 days. Subsequently, the subgrouped animals (Avit.c, Bvit.c, Cvit.c and Dvit.c were maintained orally with 1 g/L vitamin C, while the other subgrouped animals (A, B, C and D received drinking water with negligible vitamin content throughout the study period. At the end of each monthly (28 days treatment, four animals per subgroup were selected. Urine samples were collected from each of the selected rats, after which each of the animals were anaesthetized with gaseous isoflurane and 5 mL of blood samples were collected using cardiac puncture procedure. The animals were later decapitated and their kidneys harvested. The samples collected were analyzed for urine [specific gravity (SG, pH, protein and glucose], blood (urea, creatinine, total protein and glucose, and the histological studies on kidney slides. The dose and exposure- time dependent PQ toxicity resulted in the reduction in urinary pH, elevation in urinary SG, and the detectable presence of protein and glucose in urine. It also caused marked elevation in serum urea and creatinine levels with reduction in serum protein and glucose levels and alterations in the cellular integrity of the renal architecture, especially the glomeruli and tubular tissues. Treatments on the PQ insulted animals with vitamin

  9. Repeating Marx

    DEFF Research Database (Denmark)

    Fuchs, Christian; Monticelli, Lara

    2018-01-01

    This introduction sets out the context of the special issue “Karl Marx @ 200: Debating Capitalism & Perspectives for the Future of Radical Theory”, which was published on the occasion of Marx’s bicentenary on 5 May 2018. First, we give a brief overview of contemporary capitalism’s development...... and its crises. Second, we argue that it is important to repeat Marx today. Third, we reflect on lessons learned from 200 years of struggles for alternatives to capitalism. Fourth, we give an overview of the contributions in this special issue. Taken together, the contributions in this special issue show...... that Marx’s theory and politics remain key inspirations for understanding exploitation and domination in 21st-century society and for struggles that aim to overcome these phenomena and establishing a just and fair society. We need to repeat Marx today....

  10. 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.

  11. EPINEPHRINE CONCENTRATION IN WILD BOAR (SUS SCROFA L. SERUM AFTER REPEATED ELISA TESTED FREEZE-THAWING CYCLES

    Directory of Open Access Journals (Sweden)

    Neška Vukšić

    2013-06-01

    Full Text Available Blood samples for determining of epinephrine concentration and biochemical parameters in the blood serum of wild boars were taken from 42 healthy wild boars, both sexes, during the hunting season. All animals in good condition, body weight 20 to 95 kg, were divided into two groups up to 50 kg (group A and up to 95 kg (Group B. Epinephrine concentration was determined by ELISA twice: one week after taking samples and a month after repeated freezing at -80°C. It was higher in relation to the reference value of domestic pigs and human (109.45 pg/ml in A and 119.54 pg/ml in B group. Repeated freezing and re-analysis after a month were resulted in lower concentrations of epinephrine (12% in young and 11.17% in adult animal, but without statistical significance (P>0.05. Biochemical analysis results’ show increased glucose and triglycerides concentrations compared to the reference values, while other indicators were observed within or slightly increased referring to the normal range. The correlation between glucose and epinephrine was not determined.

  12. The Mere Exposure Instruction Effect.

    Science.gov (United States)

    Van Dessel, Pieter; Mertens, Gaëtan; Smith, Colin Tucker; De Houwer, Jan

    2017-09-01

    The mere exposure effect refers to the well-established finding that people evaluate a stimulus more positively after repeated exposure to that stimulus. We investigated whether a change in stimulus evaluation can occur also when participants are not repeatedly exposed to a stimulus, but are merely instructed that one stimulus will occur frequently and another stimulus will occur infrequently. We report seven experiments showing that (1) mere exposure instructions influence implicit stimulus evaluations as measured with an Implicit Association Test (IAT), personalized Implicit Association Test (pIAT), or Affect Misattribution Procedure (AMP), but not with an Evaluative Priming Task (EPT), (2) mere exposure instructions influence explicit evaluations, and (3) the instruction effect depends on participants' memory of which stimulus will be presented more frequently. We discuss how these findings inform us about the boundary conditions of mere exposure instruction effects, as well as the mental processes that underlie mere exposure and mere exposure instruction effects.

  13. Plutonium-aerosol emission rates and potential inhalation exposure during cleanup and treatment test at Area 11, Nevada Test Site

    International Nuclear Information System (INIS)

    Shinn, J.H.; Homan, D.N.

    1985-01-01

    A Cleanup and Treatment (CAT) test was conducted in 1981 at Area 11, Nevada Test Site. Its purpose was to evaluate the effectiveness of using a large truck-mounted vacuum cleaner similar to those used to clean paved streets for cleaning radiological contamination from the surface of desert soils. We found that four passes with the vehicle removed 97% of the alpha contamination and reduced resuspension by 99.3 to 99.7%. Potential exposure to cleanup workers was slight when compared to natural background exposure. 7 refs., 1 fig., 2 tabs

  14. Rationale and design of REACT: a randomised controlled trial assessing the effectiveness of home-collection to increase chlamydia retesting and detect repeat positive tests.

    Science.gov (United States)

    Smith, Kirsty S; Hocking, Jane S; Chen, Marcus; Fairley, Christopher K; McNulty, Anna; Read, Phillip; Bradshaw, Catriona S; Tabrizi, Sepehr N; Wand, Handan; Saville, Marion; Rawlinson, William; Garland, Suzanne M; Donovan, Basil; Kaldor, John M; Guy, Rebecca

    2014-04-24

    Repeat infection with Chlamydia trachomatis is common and increases the risk of sequelae in women and HIV seroconversion in men who have sex with men (MSM). Despite guidelines recommending chlamydia retesting three months after treatment, retesting rates are low. We are conducting the first randomised controlled trial to assess the effectiveness of home collection combined with short message service (SMS) reminders on chlamydia retesting and reinfection rates in three risk groups. The REACT (retest after Chlamydia trachomatis) trial involves 600 patients diagnosed with chlamydia: 200 MSM, 200 women and 200 heterosexual men recruited from two Australian sexual health clinics where SMS reminders for retesting are routine practice. Participants will be randomised to the home group (3-month SMS reminder and home-collection) or the clinic group (3-month SMS reminder to return to the clinic). Participants in the home group will be given the choice of attending the clinic if they prefer. The mailed home-collection kit includes a self-collected vaginal swab (women), UriSWAB (Copan) for urine collection (heterosexual men), and UriSWAB plus rectal swab (MSM). The primary outcome is the retest rate at 1-4 months after a chlamydia diagnosis, and the secondary outcomes are: the repeat positive test rate; the reinfection rate; the acceptability of home testing with SMS reminders; and the cost effectiveness of home testing. Sexual behaviour data collected via an online survey at 4-5 months, and genotyping of repeat infections, will be used to discriminate reinfections from treatment failures. The trial will be conducted over two years. An intention to treat analysis will be conducted. This study will provide evidence about the effectiveness of home-collection combined with SMS reminders on chlamydia retesting, repeat infection and reinfection rates in three risk groups. The trial will determine client acceptability and cost effectiveness of this strategy. Australian and New

  15. Electrostatic Discharge Test of Multi-Junction Solar Array Coupons After Combined Space Environmental Exposures

    Science.gov (United States)

    Wright, Kenneth H.; Schneider, Todd; Vaughn, Jason; Hoang, Bao; Funderburk, Victor V.; Wong, Frankie; Gardiner, George

    2010-01-01

    A set of multi-junction GaAs/Ge solar array test coupons were subjected to a sequence of 5-year increments of combined environmental exposure tests. The test coupons capture an integrated design intended for use in a geosynchronous (GEO) space environment. A key component of this test campaign is conducting electrostatic discharge (ESD) tests in the inverted gradient mode. The protocol of the ESD tests is based on the ISO/CD 11221, the ISO standard for ESD testing on solar array panels. This standard is currently in its final review with expected approval in 2010. The test schematic in the ISO reference has been modified with Space System/Loral designed circuitry to better simulate the on-orbit operational conditions of its solar array design. Part of the modified circuitry is to simulate a solar array panel coverglass flashover discharge. All solar array coupons used in the test campaign consist of 4 cells. The ESD tests are performed at the beginning of life (BOL) and at each 5-year environment exposure point. The environmental exposure sequence consists of UV radiation, electron/proton particle radiation, thermal cycling, and ion thruster plume. This paper discusses the coverglass flashover simulation, ESD test setup, and the importance of the electrical test design in simulating the on-orbit operational conditions. Results from 5th-year testing are compared to the baseline ESD characteristics determined at the BOL condition.

  16. Segmental hair testing to disclose chronic exposure to psychoactive drugs.

    Science.gov (United States)

    Marchei, Emilia; Palmi, Ilaria; Pichini, Simona; Pacifici, Roberta; Anton Airaldi, Ileana-Rita; Costa Orvay, Juan Antonio; García Serra, Joan; Bonet Serra, Bartolomé; García-Algar, Óscar

    2016-06-15

    This study presents the case of a 4-year-old healthy child admitted to the paediatric ward for suspected accidental intoxication due to ingestion of narcoleptic drugs (methylphenidate, sertraline and quetiapine), taken on a regular basis by his 8-year-old brother affected by Asperger syndrome.Intoxication can be objectively assessed by measurements of drugs and metabolites in biological matrices with short-term (blood and urine) or long-term (hair) detection windows. At the hospital, the child's blood and urine were analysed by immunoassay (confirmed by liquid chromatography-mass spectrometry), and sertraline and quetiapine and their metabolites were identified. The suspicion that the mother administered drugs chronically prompted the analysis of six, consecutive 2-cm segments of the child's hair, using ultra-high performance liquid chromatography-tandem mass spectrometry, thereby accounting for ingestion over the previous 12 months. Quetiapine was found in the first four segments with a mean concentration of 1.00 ng/mg ± 0.94 ng/mg hair while sertraline and its metabolite, desmethyl-sertraline, were found in all segments with a mean concentration of 2.65 ± 0.94 ng/mg and 1.50 ± 0.94 ng/mg hair, respectively. Hair analyses were negative for methylphenidate and its metabolite (ritalinic acid). Biological matrices testing for psychoactive drugs disclosed both acute and chronic intoxication with quetiapine and sertraline administered by the mother.

  17. Aging, recall and recognition: a study on the sensitivity of the University of Southern California Repeatable Episodic Memory Test (USC-REMT).

    Science.gov (United States)

    Parker, Elizabeth S; Landau, Susan M; Whipple, Stephen C; Schwartz, Barbara L

    2004-05-01

    This study examines the sensitivity of the University of Southern California Repeatable Episodic Memory Test (USC-REMT) to the effects of aging in a sample of 112 men and women from 18 to 93 years old. Two new recognition measures, yes-no and forced-choice, were developed to supplement the original USC-REMT which measured only free-recall. Free-recall, yes-no recognition and forced-choice recognition were sensitive to age effects, with free-recall being the most sensitive. The seven recall and recognition lists can be used interchangeably. The data indicate that the USC-REMT is worthy of consideration when there is a need for a brief, screening tool of various memory functions, particularly when there is interest in memory changes over time and repeated assessments.

  18. Repeated exposure of human fibroblasts to ionizing radiation reveals an adaptive response that is not mediated by interleukin-6 or TGF-β

    International Nuclear Information System (INIS)

    Dieriks, Birger; De Vos, Winnok; Baatout, Sarah; Van Oostveldt, Patrick

    2011-01-01

    Exposing cells to a low dose can protect them against a subsequent higher exposure. This phenomenon is known as adaptive response and is frequently observed in a variety of cells. Even though similarities are suspected with other non-targeted effects, such as bystander effects, the exact mechanism behind adaptive response is not fully clarified. In this study human primary fibroblasts were tested for their response to ionizing radiation (IR) after administrating a low priming dose (0.1-0.5 Gy). Both the abundance of γH2AX as a marker for double-stranded breaks and the levels of cytokines, secreted in the medium, were monitored in time. Upon challenge, IR-primed cells showed modified γH2AX spot size distributions and altered repair kinetics, consistent with an adaptive response. In addition, 24 h after priming with IR, four cytokines were significantly upregulated in the medium - GM-CSF (1.33x); IL6 (4.24x); IL8 (1.33x); TGF-β (1.46x). In order to mimick the protective effect of IR priming, we primed the cells with either IL6 or TGF-β. This did not elicit an altered γH2AX response as observed in IR-primed cells, indicating that the adaptive response in these primary fibroblasts is regulated in an IL-6 and TGF-β independent manner.

  19. Repeated oral administration of capsaicin increases anxiety-like ...

    Indian Academy of Sciences (India)

    This study was conducted to examine the psycho-emotional effects of repeated oral exposure to capsaicin, the principal active component of chili peppers. Each rat received 1 mL of 0.02% capsaicin into its oral cavity daily, and was subjected to behavioural tests following 10 daily administrations of capsaicin. Stereotypy ...

  20. Youth exposure to in-vehicle second-hand smoke and their smoking behaviours: trends and associations in repeated national surveys (2006-2012).

    Science.gov (United States)

    Healey, Benjamin; Hoek, Janet; Wilson, Nick; Thomson, George; Taylor, Steve; Edwards, Richard

    2015-03-01

    To extend the limited international evidence on youth in-vehicle second-hand smoke (SHS) exposure by examining trends in New Zealand, a country with a national smoke-free goal and indoors smoke-free environment legislation. We tracked exposure rates and explored the associations between in-vehicle SHS exposure and smoking behaviours. In-home exposure was also examined for comparative purposes. Data were collected in annual surveys of over 25 000 year 10 school students (14-15-year olds) for a 7-year period (2006-2012). Questions covered smoking behaviour, exposure to smoking and demographics. Youth SHS exposure rates in-vehicle and in-home trended down slightly over time (pvehicle in the previous week in 2012. However, marked inequalities in exposure between ethnic groups, and by school-based socioeconomic position, persisted. The strongest association with SHS exposure was parental smoking (eg, for both parents versus neither smoking in 2012: in-vehicle SHS exposure adjusted OR: 7.4; 95% CI: 6.5 to 8.4). After adjusting for seven other factors associated with initiation, logistic regression analyses revealed statistically significant associations of in-vehicle SHS exposure with susceptibility to initiation and smoking. The slow decline in SHS exposure in vehicles and the lack of progress in reducing relative inequalities is problematic. To accelerate progress, the New Zealand Government could follow the example of other jurisdictions and prohibit smoking in cars carrying children. Other major policy interventions, beside enhanced smoke-free environments, will also likely be required if New Zealand is to achieve its 2025 smoke-free nation goal. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  1. Repeat exposure to ciguatoxin leads to enhanced and sustained thermoregulatory, pain threshold and motor activity responses in mice: relationship to blood ciguatoxin concentrations.

    Science.gov (United States)

    Bottein Dechraoui, Marie-Yasmine; Rezvani, Amir H; Gordon, Christopher J; Levin, Edward D; Ramsdell, John S

    2008-04-03

    Ciguatera is a common illness in tropical and subtropical regions that manifests in complex and long-lived symptoms which are more severe in subsequent exposures. This study measures central and peripheral neurologic signs, in parallel with blood toxin levels, in mice exposed once or twice (at 3 days interval) to a sublethal dose of ciguatoxin P-CTX-1 (0.26ng/g via i.p.). Mice were implanted with radiotransmitters to monitor motor activity and core temperature. A single exposure to ciguatoxin elicited an immediate and transient decrease in motor activity and temperature, and subsequent long-lasting thermoregulatory dysfunction resulting in stabilized body temperature around 36.0 degrees C with no observable circadian rhythm. The hypothermic response and the reduced activity were enhanced with a second exposure with 30% of the mice dying within 7h. Measurement of the peripheral nervous system by the tail flick assay revealed increased latency with a single ciguatoxin exposure, and a greater effect following the second exposure. Toxin was measurable in blood up to 3 days following the first exposure; at the 1h time point the concentrations were significantly elevated after a second exposure. These findings indicate an early response to ciguatoxin manifest in a central response to lower body temperature and reduce motor activity and a more persistent effect on the peripheral system leading to spinal heat antinociception and delayed fever-like response. The greater neurological response to a second ciguatoxin exposure was associated with elevated concentrations of ciguatoxin in the blood solely over the first hour of exposure. In conclusion, a single exposure to toxin exerts a significant neurological response which may be enhanced with subsequent exposure.

  2. Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing - Part 2

    Science.gov (United States)

    Montgomery, Eliza L.; Calle, Luz Marina; Curran, Jerome C.; Kolody, Mark R.

    2012-01-01

    Evaluation of metals to predict service life of metal-based structures in corrosive environments has long relied on atmospheric exposure test sites. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating salt spray and ultraviolet (UV) radiation, and exposing the metal to continuous or cyclic conditions similar to those of the corrosive environment. Their reliability to correlate to atmospheric exposure test results is often a concern when determining the timescale to which the accelerated tests can be related. Accelerated corrosion testing has yet to be universally accepted as a useful tool in predicting the long-term service life of a metal, despite its ability to rapidly induce corrosion. Although visual and mass loss methods of evaluating corrosion are the standard, and their use is crucial, a method that correlates timescales from accelerated testing to atmospheric exposure would be very valuable. This paper presents work that began with the characterization of the atmospheric environment at the Kennedy Space Center (KSC) Beachside Corrosion Test Site. The chemical changes that occur on low carbon steel, during atmospheric and accelerated corrosion conditions, were investigated using surface chemistry analytical methods. The corrosion rates and behaviors of panels subjected to long-term and accelerated corrosion conditions, involving neutral salt fog and alternating seawater spray, were compared to identify possible timescale correlations between accelerated and long-term corrosion performance. The results, as well as preliminary findings on the correlation investigation, are presented.

  3. Avoidance test with Enchytraeus albidus (Enchytraeidae): Effects of different exposure time and soil properties

    International Nuclear Information System (INIS)

    Amorim, Monica J.B.; Novais, Sara; Roembke, Joerg; Soares, Amadeu M.V.M.

    2008-01-01

    Enchytraeids are ecologically relevant soil species and are commonly used in standardized toxicity tests. Their rapid reaction to a chemical exposure can be used as a toxicological measurement endpoint that assesses the avoidance behavior. The objectives of this investigation were to determine the effects of soil properties on the avoidance behavior of Enchytraeus albidus and to optimize the duration of avoidance test. The avoidance tests included (1) exposures in OECD artificial soil with standard or modified properties (pH, clay or peat content), and (2) exposures to copper chloride, cadmium chloride, and to the organic pesticides dimethoate and phenmedipham for different time periods. Results showed that alteration of OECD soil constituents significantly affected the avoidance behavior of enchytraeids, and that the 48-h exposure was the optimal duration of the test. Consideration of soil properties is important for selecting appropriate experimental design and interpreting the results of the enchytraeid avoidance test. - Optimal duration of the avoidance tests with potworm Enchytraeus albidus is 48 h; soil properties can affect performance of the test species

  4. Laboratory studies on the effect of freezing and thawing exposure on bentonite buffer performance: Closed-system tests

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, T.; Martikainen, J. [B and Tech Oy, Helsinki (Finland)

    2010-12-15

    This report presents a set of results from laboratory studies on the effect of freezing and thawing on compacted bentonite buffer material. In order to evaluate the effect of freezing and thawing on compacted bentonite buffer performance a series of experiments were conducted using closed, constant-volume cells as follows: Pre- and post-freezing swelling pressure measurements were performed on fully saturated MX-80 and Deponit CA-N bentonite samples, at dry density values of approximately 1.6 g/cm{sup 3}, over five freeze/thaw cycles from room temperature to -18 deg C with rapid (instantaneous) temperature exposure. Pressure measurements were performed on fully saturated MX-80 bentonite samples, at dry density values of 1.470 and 1.501 g/cm{sup 3}, during a temperature run from room temperature to -10 deg C with step-change temperature exposure and back from -10 deg C to room temperature under continuous temperature change exposure at 0.1 deg C/h. Pressure measurements were performed on fully saturated MX-80 bentonite samples, encompassing a range of dry density values from 0.940 to 1.534 g/cm{sup 3}, during repeated temperature runs from room temperature to -10 deg C and back with continuous temperature change exposure at 0.1 deg C/h. Pressure measurements were performed on a fully saturated Deponit CA-N bentonite sample, at a dry density of 1.484 g/cm{sup 3}, during a temperature run from room temperature to -10 deg C and back with continuous temperature change exposure at 0.1 deg C/h. In some cases, hydraulic conductivity measurements were performed before and after freeze/thaw exposure. In general, exposure to freezing temperatures, down to an average temperature of -10 deg C, results in the development of significant internal pressures in compacted bentonite samples, which is attributed to the formation of ice. The specific test results are summarised as follows: Increases in pressure by factors of 1.5 to 2.2 were observed for MX-80 samples at dry densities

  5. Lexical-Semantic Organization in Bilingually Developing Deaf Children with ASL-Dominant Language Exposure: Evidence from a Repeated Meaning Association Task

    Science.gov (United States)

    Mann, Wolfgang; Sheng, Li; Morgan, Gary

    2016-01-01

    This study compared the lexical-semantic organization skills of bilingually developing deaf children in American Sign Language (ASL) and English with those of a monolingual hearing group. A repeated meaning-association paradigm was used to assess retrieval of semantic relations in deaf 6-10-year-olds exposed to ASL from birth by their deaf…

  6. Repeated Miscarriage

    Science.gov (United States)

    ... In vitro fertilization with special genetic testing called preimplantation genetic diagnosis may be done to select unaffected embryos. How ... an increase in the levels of certain hormones. Preimplantation Genetic Diagnosis: A type of genetic testing that can be ...

  7. Unconsented HIV testing in cases of occupational exposure: ethics, law, and policy.

    Science.gov (United States)

    Cowan, Ethan; Macklin, Ruth

    2012-10-01

    Postexposure prophylaxis (PEP) has substantially reduced the risk of acquiring human immunodeficiency virus (HIV) after an occupational exposure; nevertheless, exposure to HIV remains a concern for emergency department providers. According to published guidelines, PEP should be taken only when source patients are HIV-positive or have risk factors for HIV. Initiating PEP when source patients are uninfected puts exposed persons at risk from taking toxic drugs with no compensating benefit. Forgoing PEP if the source is infected results in increased risk of acquiring HIV. What should be done if source patients refuse HIV testing? Is it justifiable to test the blood of these patients over their autonomous objection? The authors review current law and policy and perform an ethical analysis to determine if laws permitting unconsented testing in cases of occupational exposure can be ethically justified. © 2012 by the Society for Academic Emergency Medicine.

  8. The assessment of radiation exposures in native American communities from nuclear weapons testing in Nevada

    International Nuclear Information System (INIS)

    Frohmberg, E.; Goble, R.; Sanchez, V.; Quigley, D.

    2000-01-01

    Native Americans residing in a broad region downwind from the Nevada Test Site during the 1950s and 1960s received significant radiation exposures from nuclear weapons testing. Because of differences in diet, activities, and housing, their radiation exposures are only very imperfectly represented in the Department of Energy dose reconstructions. There are important missing pathways, including exposures to radioactive iodine from eating small game. The dose reconstruction model assumptions about cattle feeding practices across a year are unlikely to apply to the native communities as are other model assumptions about diet. Thus exposures from drinking milk and eating vegetables have not yet been properly estimated for these communities. Through consultations with members of the affected communities, these deficiencies could be corrected and the dose reconstruction extended to Native Americans. An illustration of the feasibility of extending the dose reconstruction is provided by a sample calculation to estimate radiation exposures to the thyroid from eating radio-iodine-contaminated rabbit thyroids after the Dedan test. The illustration is continued with a discussion of how the calculation results may be used to make estimates for other tests and other locations

  9. Test-retest repeatability of myocardial oxidative metabolism and efficiency using standalone dynamic 11C-acetate PET and multimodality approaches in healthy controls.

    Science.gov (United States)

    Hansson, Nils Henrik; Harms, Hendrik Johannes; Kim, Won Yong; Nielsen, Roni; Tolbod, Lars P; Frøkiær, Jørgen; Bouchelouche, Kirsten; Poulsen, Steen Hvitfeldt; Wiggers, Henrik; Parner, Erik Thorlund; Sörensen, Jens

    2018-05-31

    Myocardial efficiency measured by 11 C-acetate positron emission tomography (PET) has successfully been used in clinical research to quantify mechanoenergetic coupling. The objective of this study was to establish the repeatability of myocardial external efficiency (MEE) and work metabolic index (WMI) by non-invasive concepts. Ten healthy volunteers (63 ± 4 years) were examined twice, one week apart, using 11 C-acetate PET, cardiovascular magnetic resonance (CMR), and echocardiography. Myocardial oxygen consumption from PET was combined with stroke work data from CMR, echocardiography, or PET to obtain MEE and WMI for each modality. Repeatability was estimated as the coefficient of variation (CV) between test and retest. MEE CMR , MEE Echo , and MEE PET values were 21.9 ± 2.7%, 16.4 ± 3.7%, and 23.8 ± 4.9%, respectively, P PET values were 4.42 ± 0.90, 4.07 ± 0.63, and 4.58 ± 1.13 mmHg × mL/m 2  × 10 6 , respectively, P = .45. Repeatability for MEE CMR was superior compared with MEE Echo but did not differ significantly compared with MEE PET (6.3% vs 12.9% and 9.4%, P = .04 and .25). CV values for WMI CMR , WMI Echo , and WMI PET were 10.0%, 14.8%, and 12.0%, respectively, (P = .53). Non-invasive measurements of MEE using 11 C-acetate PET are highly repeatable. A PET-only approach did not differ significantly from CMR/PET and might facilitate further clinical research due to lower costs and broader applicability.

  10. Performance and Metabolic Demand of a New Repeated-Sprint Ability Test in Basketball Players: Does the Number of Changes of Direction Matter?

    Science.gov (United States)

    Zagatto, Alessandro M; Ardigò, Luca P; Barbieri, Fabio A; Milioni, Fabio; Dello Iacono, Antonio; Camargo, Bruno H F; Padulo, Johnny

    2017-09-01

    Zagatto, AM, Ardigò, LP, Barbieri, FA, Milioni, F, Dello Iacono, A, Camargo, BHF, and Padulo, J. Performance and metabolic demand of a new repeated-sprint ability test in basketball players: does the number of changes of direction matter? J Strength Cond Res 31(9): 2438-2446, 2017-This study compared 2 repeated-sprint ability (RSA) tests in basketball players. Both tests included 10 × 30-m sprints, with the difference that the previously validated test (RSA2COD) featured 2 changes of direction (COD) per sprint, whereas the experimental test (RSA5COD) featured 5 CODs per sprint. Test performances and metabolic demands were specifically assessed in 20 basketball players. First, RSA5COD test-retest reliability was investigated. Then, RSA2COD, RSA5COD sprint times, peak speeds, oxygen uptake (V[Combining Dot Above]O2) and posttest blood lactate concentration [La] were measured. The RSA5COD results showed to be reliable. RSA2COD performance resulted better than the RSA5COD version (p 0.05). Over whole bout, the RSA2COD was more demanding than the RSA5COD, considering overall metabolic power requirement (i.e., VO2-driven + [La]-driven components). Given that RSA5COD (a) mimics real game-play as sprint distance and action change frequency/direction and (b) has the same metabolic expenditure per task completion as metabolic cost, RSA5COD is a valuable option for players and coaches for training basketball-specific agility and assessing bioenergetic demands.

  11. Testing pathways linking exposure to community violence and sexual behaviors among African American youth.

    Science.gov (United States)

    Voisin, Dexter R; Hotton, Anna L; Neilands, Torsten B

    2014-09-01

    Exposure to community violence and HIV sexual risks are two major public health concerns among youth. This study tests various pathways linking exposure to community violence and sexual behaviors among African American adolescents. Using a sample of 563 (61% females) African American youth attending high school we examined whether problematic psychological symptoms, low school engagement, and/or negative perceptions of peer norms about safer sex functioned as pathways linking exposure to community violence and sexual behaviors. Major findings indicated that, for boys, the relationship between exposure to community violence and sexual début and sexual risk behaviors were linked by aggression. In addition, the relationship between exposure to community violence and sexual risk behaviors were linked by negative perceptions of peer attitudes about safer sex. For girls, the relationship between exposure to community violence and sexual début was linked by aggression and negative perceptions of peer attitudes about safer sex. These findings provide support for pathways linking exposure to community violence to sexual behaviors.

  12. Hypoxia Stress Test Reveals Exaggerated Cardiovascular Effects in Hypertensive Rats after Exposure to the Air Pollutant Acrolein

    Science.gov (United States)

    Exposure to air pollution increases the risk of cardiovascular morbidity and mortality, especially in susceptible populations with cardiovascular disease. Stress tests are useful in assessing cardiovascular risk and manifesting latent effects of exposure. The goal of this study w...

  13. Assessment of cognition using the Rao's Brief Repeatable Battery of Neuropsychological Tests on a group of Brazilian patients with multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Joseph Bruno Bidin Brooks

    2011-12-01

    Full Text Available To assess the cognition of patients with multiple sclerosis (MS using the Rao's Brief Repeatable Battery of Neuropsychological Tests (BRB-N. METHOD: BRB-N was translated and adapted for control subjects. Subsequently, it was applied to a group of patients with relapsing-remitting (RR MS. RESULTS: The assessment on the healthy controls (n=47 showed that the correlation between tests on the same cognitive domain was high and that there was a five-factor solution that explained 90% of the total variance. Except for the Word List Generation subset of tests, the performance of patients with RRMS (n=39 was worse than that of the healthy controls. CONCLUSION: BRB-N is a relatively simple method to assess cognition of patients with MS in the daily clinic. It does not take long to apply and does not require special skills or equipment.

  14. Evaluation of the Repeatability of the Delta Q Duct Leakage Testing TechniqueIncluding Investigation of Robust Analysis Techniques and Estimates of Weather Induced Uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Dickerhoff, Darryl; Walker, Iain

    2008-08-01

    The DeltaQ test is a method of estimating the air leakage from forced air duct systems. Developed primarily for residential and small commercial applications it uses the changes in blower door test results due to forced air system operation. Previous studies established the principles behind DeltaQ testing, but raised issues of precision of the test, particularly for leaky homes on windy days. Details of the measurement technique are available in an ASTM Standard (ASTM E1554-2007). In order to ease adoption of the test method, this study answers questions regarding the uncertainty due to changing weather during the test (particularly changes in wind speed) and the applicability to low leakage systems. The first question arises because the building envelope air flows and pressures used in the DeltaQ test are influenced by weather induced pressures. Variability in wind induced pressures rather than temperature difference induced pressures dominates this effect because the wind pressures change rapidly over the time period of a test. The second question needs to answered so that DeltaQ testing can be used in programs requiring or giving credit for tight ducts (e.g., California's Building Energy Code (CEC 2005)). DeltaQ modeling biases have been previously investigated in laboratory studies where there was no weather induced changes in envelope flows and pressures. Laboratory work by Andrews (2002) and Walker et al. (2004) found biases of about 0.5% of forced air system blower flow and individual test uncertainty of about 2% of forced air system blower flow. The laboratory tests were repeated by Walker and Dickerhoff (2006 and 2008) using a new ramping technique that continuously varied envelope pressures and air flows rather than taking data at pre-selected pressure stations (as used in ASTM E1554-2003 and other previous studies). The biases and individual test uncertainties for ramping were found to be very close (less than 0.5% of air handler flow) to those

  15. Effect of restrictions on television food advertising to children on exposure to advertisements for 'less healthy' foods: repeat cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Jean Adams

    Full Text Available In 2007, new scheduling restrictions on television food advertising to children in the UK were announced. The aim of the restrictions was to "reduce significantly the exposure of children under 16 to high fat, salt or sugar (HFSS advertising". We explored the impact of the restrictions on relative exposure to HFSS food advertising among all viewers and among child television viewers, as well as adherence to the restrictions.We conducted two cross-sectional studies of all advertisements broadcast in one region of the UK over one week periods--the first (week 1 six months before the restrictions were introduced, and the second (week 2 six months after. Data on what products were advertised were linked to data on how many people watched each advertisement. Nutritional content of foods advertised was added to the dataset and used to calculate HFSS status. Relative exposure was calculated as the proportion of all advertising person-minute-views (PMVs that were for HFSS foods.1,672,417 advertising PMV were included. 14.6% of advertising PMV were for food and 51.1% of these were for HFSS food. Relative exposure of all viewers to HFSS food advertising increased between study weeks 1 and 2 (odds ratio (99% confidence intervals = 1·54 (1·51 to 1·57. Exposure of children to HFSS food advertising did not change between study weeks 1 and 2 (odds ratio (99% confidence intervals = 1·05 (0·99 to 1·12. There was almost universal adherence to the restrictions.Despite good adherence to the restrictions, they did not change relative exposure of children to HFSS advertising and were associated with an increase in relative exposure of all viewers to HFSS advertising. Stronger restrictions targeting a wider range of advertisements are necessary to reduce exposure of children to marketing of less healthful foods.

  16. Effect of restrictions on television food advertising to children on exposure to advertisements for 'less healthy' foods: repeat cross-sectional study.

    Science.gov (United States)

    Adams, Jean; Tyrrell, Rachel; Adamson, Ashley J; White, Martin

    2012-01-01

    In 2007, new scheduling restrictions on television food advertising to children in the UK were announced. The aim of the restrictions was to "reduce significantly the exposure of children under 16 to high fat, salt or sugar (HFSS) advertising". We explored the impact of the restrictions on relative exposure to HFSS food advertising among all viewers and among child television viewers, as well as adherence to the restrictions. We conducted two cross-sectional studies of all advertisements broadcast in one region of the UK over one week periods--the first (week 1) six months before the restrictions were introduced, and the second (week 2) six months after. Data on what products were advertised were linked to data on how many people watched each advertisement. Nutritional content of foods advertised was added to the dataset and used to calculate HFSS status. Relative exposure was calculated as the proportion of all advertising person-minute-views (PMVs) that were for HFSS foods. 1,672,417 advertising PMV were included. 14.6% of advertising PMV were for food and 51.1% of these were for HFSS food. Relative exposure of all viewers to HFSS food advertising increased between study weeks 1 and 2 (odds ratio (99% confidence intervals) = 1·54 (1·51 to 1·57)). Exposure of children to HFSS food advertising did not change between study weeks 1 and 2 (odds ratio (99% confidence intervals) = 1·05 (0·99 to 1·12)). There was almost universal adherence to the restrictions. Despite good adherence to the restrictions, they did not change relative exposure of children to HFSS advertising and were associated with an increase in relative exposure of all viewers to HFSS advertising. Stronger restrictions targeting a wider range of advertisements are necessary to reduce exposure of children to marketing of less healthful foods.

  17. Effect of Restrictions on Television Food Advertising to Children on Exposure to Advertisements for ‘Less Healthy’ Foods: Repeat Cross-Sectional Study

    Science.gov (United States)

    Adams, Jean; Tyrrell, Rachel; Adamson, Ashley J.; White, Martin

    2012-01-01

    Background In 2007, new scheduling restrictions on television food advertising to children in the UK were announced. The aim of the restrictions was to “reduce significantly the exposure of children under 16 to high fat, salt or sugar (HFSS) advertising”. We explored the impact of the restrictions on relative exposure to HFSS food advertising among all viewers and among child television viewers, as well as adherence to the restrictions. Methods We conducted two cross-sectional studies of all advertisements broadcast in one region of the UK over one week periods – the first (week 1) six months before the restrictions were introduced, and the second (week 2) six months after. Data on what products were advertised were linked to data on how many people watched each advertisement. Nutritional content of foods advertised was added to the dataset and used to calculate HFSS status. Relative exposure was calculated as the proportion of all advertising person-minute-views (PMVs) that were for HFSS foods. Results 1,672,417 advertising PMV were included. 14.6% of advertising PMV were for food and 51.1% of these were for HFSS food. Relative exposure of all viewers to HFSS food advertising increased between study weeks 1 and 2 (odds ratio (99% confidence intervals) = 1·54 (1·51 to 1·57)). Exposure of children to HFSS food advertising did not change between study weeks 1 and 2 (odds ratio (99% confidence intervals) = 1·05 (0·99 to 1·12)). There was almost universal adherence to the restrictions. Conclusions Despite good adherence to the restrictions, they did not change relative exposure of children to HFSS advertising and were associated with an increase in relative exposure of all viewers to HFSS advertising. Stronger restrictions targeting a wider range of advertisements are necessary to reduce exposure of children to marketing of less healthful foods. PMID:22355376

  18. Repeated intermittent alcohol exposure during the third trimester-equivalent increases expression of the GABA(A) receptor δ subunit in cerebellar granule neurons and delays motor development in rats.

    Science.gov (United States)

    Diaz, Marvin R; Vollmer, Cyndel C; Zamudio-Bulcock, Paula A; Vollmer, William; Blomquist, Samantha L; Morton, Russell A; Everett, Julie C; Zurek, Agnieszka A; Yu, Jieying; Orser, Beverley A; Valenzuela, C Fernando

    2014-04-01

    Exposure to ethanol (EtOH) during fetal development can lead to long-lasting alterations, including deficits in fine motor skills and motor learning. Studies suggest that these are, in part, a consequence of cerebellar damage. Cerebellar granule neurons (CGNs) are the gateway of information into the cerebellar cortex. Functionally, CGNs are heavily regulated by phasic and tonic GABAergic inhibition from Golgi cell interneurons; however, the effect of EtOH exposure on the development of GABAergic transmission in immature CGNs has not been investigated. To model EtOH exposure during the 3rd trimester-equivalent of human pregnancy, neonatal pups were exposed intermittently to high levels of vaporized EtOH from postnatal day (P) 2 to P12. This exposure gradually increased pup serum EtOH concentrations (SECs) to ∼60 mM (∼0.28 g/dl) during the 4 h of exposure. EtOH levels gradually decreased to baseline 8 h after the end of exposure. Surprisingly, basal tonic and phasic GABAergic currents in CGNs were not significantly affected by postnatal alcohol exposure (PAE). However, PAE increased δ subunit expression at P28 as detected by immunohistochemical and western blot analyses. Also, electrophysiological studies with an agonist that is highly selective for δ-containing GABA(A) receptors, 4,5,6,7-tetrahydroisoxazolo[4,5-c]pyridine-3-ol (THIP), showed an increase in THIP-induced tonic current. Behavioral studies of PAE rats did not reveal any deficits in motor coordination, except for a delay in the acquisition of the mid-air righting reflex that was apparent at P15 to P18. These findings demonstrate that repeated intermittent exposure to high levels of EtOH during the equivalent of the last trimester of human pregnancy has significant but relatively subtle effects on motor coordination and GABAergic transmission in CGNs in rats. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. The effects of a single whole body cryotherapy exposure on physiological, performance and perceptual responses of professional academy soccer players following repeated sprint exercise

    OpenAIRE

    Russell, Mark; Birch, Jack; Love, Thomas; Cook, Christian; Bracken, Richard M.; Taylor, Tom; Swift, Eamon; Cockburn, Emma; Finn, Charlie; Cunningham, Daniel; Wilson, Laura; Kilduff, Liam P.

    2017-01-01

    In professional youth soccer players, the physiological, performance and perceptual effects of a single whole body cryotherapy (WBC) session performed shortly after repeated sprint exercise were investigated. In a randomized, counter-balanced and crossover design, 14 habituated English Premier League academy soccer players performed 15 x 30 m sprints (each followed by a 10 m forced deceleration) on two occasions. Within 20 min of exercise cessation, players entered a WBC chamber (Cryo: 30 s a...

  20. Are repeated single-limb heel raises and manual muscle testing associated with peak plantar-flexor force in people with inclusion body myositis?

    Science.gov (United States)

    Harris-Love, Michael O; Shrader, Joseph A; Davenport, Todd E; Joe, Galen; Rakocevic, Goran; McElroy, Beverly; Dalakas, Marinos

    2014-04-01

    Repeated heel raises have been proposed as a method of ankle plantar-flexor strength testing that circumvents the limitations of manual muscle testing (MMT). The study objective was to examine the relationships among ankle plantar-flexion isometric maximum voluntary contraction (MVC), repeated single-limb heel raises (SLHRs), and MMT in people with myositis. This was a cross-sectional study with a between-group design. The ability to complete 1 SLHR determined group assignment (SLHR group, n=24; no-SLHR group, n=19). Forty-three participants with myositis (13 women; median age=64.9 years) participated. Outcome measures included MVC, predicted MVC, Kendall MMT, and Daniels-Worthingham MMT. The Kendall MMT was unable to detect significant ankle plantar-flexor weakness established by quantitative methods and was unable to discriminate between participants who could and those who could not perform the SLHR task. Ankle plantar-flexion MVC was not associated with the number of heel-raise repetitions in the SLHR group (pseudo R(2)=.13). No significant relationship was observed between MVC values and MMT grades in the SLHR and no-SLHR groups. However, a moderate relationship between MVC values and MMT grades was evident in a combined-group analysis (ρ=.50-.67). The lower half of both MMT grading scales was not represented in the study despite the profound weakness of the participants. Both Kendall MMT and Daniels-Worthingham MMT had limited utility in the assessment of ankle plantar-flexor strength. Repeated SLHRs should not be used as a proxy measure of ankle plantar-flexion MVC in people with myositis.

  1. Effects of Creatine and Sodium Bicarbonate Coingestion on Multiple Indices of Mechanical Power Output During Repeated Wingate Tests in Trained Men.

    Science.gov (United States)

    Griffen, Corbin; Rogerson, David; Ranchordas, Mayur; Ruddock, Alan

    2015-06-01

    This study investigated the effects of creatine and sodium bicarbonate coingestion on mechanical power during repeated sprints. Nine well-trained men (age = 21.6 ± 0.9 yr, stature = 1.82 ± 0.05 m, body mass = 80.1 ±12.8 kg) participated in a double-blind, placebo-controlled, counterbalanced, crossover study using six 10-s repeated Wingate tests. Participants ingested either a placebo (0.5 g·kg(-1) of maltodextrin), 20 g·d(-1) of creatine monohydrate + placebo, 0.3 g·kg(-1) of sodium bicarbonate + placebo, or coingestion + placebo for 7 days, with a 7-day washout between conditions. Participants were randomized into two groups with a differential counterbalanced order. Creatine conditions were ordered first and last. Indices of mechanical power output (W), total work (J) and fatigue index (W·s(-1)) were measured during each test and analyzed using the magnitude of differences between groups in relation to the smallest worthwhile change in performance. Compared with placebo, both creatine (effect size (ES) = 0.37-0.83) and sodium bicarbonate (ES = 0.22-0.46) reported meaningful improvements on indices of mechanical power output. Coingestion provided small meaningful improvements on indices of mechanical power output (W) compared with sodium bicarbonate (ES = 0.28-0.41), but not when compared with creatine (ES = -0.21-0.14). Coingestion provided a small meaningful improvement in total work (J; ES = 0.24) compared with creatine. Fatigue index (W·s(-1)) was impaired in all conditions compared with placebo. In conclusion, there was no meaningful additive effect of creatine and sodium bicarbonate coingestion on mechanical power during repeated sprints.

  2. Changes in child exposure to secondhand smoke after implementation of smoke-free legislation in Wales: a repeated cross-sectional study

    Directory of Open Access Journals (Sweden)

    Holliday Jo

    2009-01-01

    Full Text Available Abstract Background Smoke-free legislation was introduced in Wales in April 2007. In response to concerns regarding potential displacement of smoking into the home following legislation, this study assessed changes in secondhand smoke (SHS exposure amongst non-smoking children. Methods Approximately 1,750 year 6 (aged 10-11 children from 75 Welsh primary schools were included in cross-sectional surveys immediately pre-legislation and one year later. Participants completed self-report questionnaires and provided saliva samples for cotinine assay. Regression analyses assessed the impact of legislation on children's SHS exposure at the population level, and amongst subgroups defined by parental figures who smoke within the home. Results Geometric mean salivary cotinine concentrations were 0.17 ng/ml (95% CI 0.15,0.20 pre-legislation and 0.15 ng/ml (95% CI 0.13,0.17, post-legislation, although this change was not statistically significant. Significant movement was however observed from the middle (0.10-0.50 ng/ml to lower tertile, though not from the higher end (>0.51 ng/ml to the middle. Reported exposure to SHS was greatest within the home. Home-based exposure did not change significantly post-legislation. Reported exposure in cafés or restaurants, buses and trains, and indoor leisure facilities fell significantly. The proportion of children reporting that parent figures smoked in the home declined (P = 0.03, with children with no parent figures who smoke in the home significantly more likely to provide saliva with cotinine concentrations of <0.10 ng/ml post-legislation. Amongst children with no parent figures who smoke in the home, the likelihood of 'not knowing' or 'never' being in a place where people were smoking increased post-legislation. Conclusion Smoke-free legislation in Wales did not increase SHS exposure in homes of children aged 10-11. Reported SHS exposure in public places fell significantly. The home remained the main source of

  3. Computerized Analysis of Verbal Fluency: Normative Data and the Effects of Repeated Testing, Simulated Malingering, and Traumatic Brain Injury.

    Directory of Open Access Journals (Sweden)

    David L Woods

    Full Text Available In verbal fluency (VF tests, subjects articulate words in a specified category during a short test period (typically 60 s. Verbal fluency tests are widely used to study language development and to evaluate memory retrieval in neuropsychiatric disorders. Performance is usually measured as the total number of correct words retrieved. Here, we describe the properties of a computerized VF (C-VF test that tallies correct words and repetitions while providing additional lexical measures of word frequency, syllable count, and typicality. In addition, the C-VF permits (1 the analysis of the rate of responding over time, and (2 the analysis of the semantic relationships between words using a new method, Explicit Semantic Analysis (ESA, as well as the established semantic clustering and switching measures developed by Troyer et al. (1997. In Experiment 1, we gathered normative data from 180 subjects ranging in age from 18 to 82 years in semantic ("animals" and phonemic (letter "F" conditions. The number of words retrieved in 90 s correlated with education and daily hours of computer-use. The rate of word production declined sharply over time during both tests. In semantic conditions, correct-word scores correlated strongly with the number of ESA and Troyer-defined semantic switches as well as with an ESA-defined semantic organization index (SOI. In phonemic conditions, ESA revealed significant semantic influences in the sequence of words retrieved. In Experiment 2, we examined the test-retest reliability of different measures across three weekly tests in 40 young subjects. Different categories were used for each semantic ("animals", "parts of the body", and "foods" and phonemic (letters "F", "A", and "S" condition. After regressing out the influences of education and computer-use, we found that correct-word z-scores in the first session did not differ from those of the subjects in Experiment 1. Word production was uniformly greater in semantic than

  4. Assessing the test-retest repeatability of the Vietnamese version of the National Eye Institute 25-item Visual Function Questionnaire among bilateral cataract patients for a Vietnamese population.

    Science.gov (United States)

    To, Kien Gia; Meuleners, Lynn; Chen, Huei-Yang; Lee, Andy; Do, Dung Van; Duong, Dat Van; Phi, Tien Duy; Tran, Hoang Huy; Nguyen, Nguyen Do

    2014-06-01

    To determine the test-retest repeatability of the National Eye Institute 25-item Visual Function Questionnaire (NEI VFQ-25) for use with older Vietnamese adults with bilateral cataract. The questionnaire was translated into Vietnamese and back-translated into English by two independent translators. Patients with bilateral cataract aged 50 and older completed the questionnaire on two separate occasions, one to two weeks after first administration of the questionnaire. Test-retest repeatability was assessed using the Cronbach's α and intraclass correlation coefficients. The average age of participants was 67 ± 8 years and most participants were female (73%). Internal consistency was acceptable with the α coefficient above 0.7 for all subscales and intraclass correlation coefficients were 0.6 or greater in all subscales. The Vietnamese NEI VFQ-25 is reliable for use in studies assessing vision-related quality of life in older adults with bilateral cataract in Vietnam. We propose some modifications to the NEI-VFQ questions to reflect activities of older people in Vietnam. © 2013 ACOTA.

  5. Sensitivity of continuous performance test (CPT) at age 14years to developmental methylmercury exposure

    DEFF Research Database (Denmark)

    Julvez, Jordi; Debes, Frodi; Weihe, Pal

    2010-01-01

    Hit Reaction Time latencies (HRT) in the Continuous Performance Test (CPT) measure the speed of visual information processing. The latencies may involve different neuropsychological functions depending on the time from test initiation, i.e., first orientation, learning and habituation, then cogni......Hit Reaction Time latencies (HRT) in the Continuous Performance Test (CPT) measure the speed of visual information processing. The latencies may involve different neuropsychological functions depending on the time from test initiation, i.e., first orientation, learning and habituation......, then cognitive processing and focused attention, and finally sustained attention as the dominant demand. Prenatal methylmercury exposure is associated with increased reaction time (RT) latencies. We therefore examined the association of methylmercury exposure with the average HRT at age 14years at three...

  6. A Model of International Communication Media Appraisal and Exposure: A Comprehensive Test in Belize.

    Science.gov (United States)

    Johnson, J. David; Oliveira, Omar Souki

    A study constituted the fifth phase of a programmatic research effort designed to develop and test a model of international communications media exposure and appraisal. The model posits that three variables--editorial tone, communication potential, and utility--have positive determinant effects on these dependent variables. Research was carried…

  7. Use of the Prostate Core Mitomic Test in Repeated Biopsy Decision-Making: Real-World Assessment of Clinical Utility in a Multicenter Patient Population.

    Science.gov (United States)

    Legisi, Lorena; DeSa, Elise; Qureshi, M Nasar

    2016-12-01

    Prostate cancer is the most common cancer diagnosed in men in developed countries. Using molecular testing may help to improve outcomes in this clinically challenging group. Since 2011, the Prostate Core Mitomic Test (PCMT), which quantifies a 3.4-kb mitochondrial DNA deletion strongly associated with prostate cancer, has been used by more than 50 urology practices accessing pathology services through our laboratory in New Jersey. However, the use of a molecular test can only be beneficial if it affects patient management and improves outcomes. To determine whether repeated biopsy decision-making was affected in a quantifiable manner through the adjunct use of molecular testing with the PCMT. In this observational study we conducted 2 independent, structured query language database queries of our patient records at our laboratory, QDx Pathology Services, in Cranford, NJ. Query 1 included all men who had a negative prostate biopsy and a negative PCMT between February 1, 2011, and June 30, 2013. Men with a previous diagnosis of cancer were excluded. Query 2 included all men who had a negative prostate biopsy and a repeated biopsy between February 1, 2011, and September 30, 2013. The data exported for each query included the unique specimen number for an index biopsy, the interval between biopsies where present, the unique specimen number for a follow-up biopsy where present, histopathology for all biopsies, the biopsy procedure dates, the patient's date of birth, and the PCMT result when utilized. The patient rebiopsy rates and intervals were compared between the patients who were using PCMT and those who were not to assess whether the adjunct use of the PCMT impacted the rebiopsy decision-making process. Query 1 identified 644 men who had a negative biopsy and a negative PCMT result within the study period. Query 2 identified 823 men with a repeat biopsy after the initial negative index biopsy within the study period. Of these men, 132 had PCMT to inform their care

  8. Individual external exposures from Nevada Test Site fallout for Utah leukemia cases and controls

    International Nuclear Information System (INIS)

    Lloyd, R.D.; Gren, D.C.; Simon, S.L.; Wrenn, M.E.; Hawthorne, H.A.; Lotz, T.M.; Stevens, W.; Till, J.E.

    1990-01-01

    External gamma-ray exposures from fallout originating at the Nevada Test Site (NTS) have been assigned to 6,507 individual subjects (1,177 leukemia cases and 5,330 control subjects) who died as Utah residents between 1952 and 1981. Leukemia cases were identified, confirmed, and classified by cell type from the Utah Cancer Registry, Utah State vital records, and medical records. Residential histories were obtained from the Deceased Membership File (DMF) of the Church of Jesus Christ of Latter-day Saints (LDS), supplemented by information from the LDS Church Census Records that were taken in 1950, 1955, and 1960-62. Control subjects were selected randomly within age strata from the DMF and were frequency-matched to the cases by age at death and for sex. Individual radiation exposures were assigned as a function of residence location and time interval for each residence during the fallout period (1951-1958) using geographic exposure data taken from the literature. Temporal distribution of exposure for subjects who resided in more than one locality or who were born or died during the fallout period was determined from data of other investigators. Calculated gamma-ray exposures for each place of residence were summed for each subject to yield the exposure to fallout from the NTS

  9. Dose-Response for Multiple Biomarkers of Exposure and Genotoxic Effect Following Repeated Treatment of Rats with the Alkylating Agents, MMS and MNU.

    Science.gov (United States)

    Ji, Zhiying; LeBaron, Matthew J; Schisler, Melissa R; Zhang, Fagen; Bartels, Michael J; Gollapudi, B Bhaskar; Pottenger, Lynn H

    2016-05-01

    The nature of the dose-response relationship for various in vivo endpoints of exposure and effect were investigated using the alkylating agents, methyl methanesulfonate (MMS) and methylnitrosourea (MNU). Six male F344 rats/group were dosed orally with 0, 0.5, 1, 5, 25 or 50mg/kg bw/day (mkd) of MMS, or 0, 0.01, 0.1, 1, 5, 10, 25 or 50 mkd of MNU, for 4 consecutive days and sacrificed 24h after the last dose. The dose-responses for multiple biomarkers of exposure and genotoxic effect were investigated. In MMS-treated rats, the hemoglobin adduct level, a systemic exposure biomarker, increased linearly with dose (r (2) = 0.9990, P agents. © The Author 2015. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Repeated short-term stress synergizes the ROS signalling through up regulation of NFkB and iNOS expression induced due to combined exposure of trichloroethylene and UVB rays.

    Science.gov (United States)

    Ali, Farrah; Sultana, Sarwat

    2012-01-01

    Restraint stress is known to catalyse the pathogenesis of the variety of chronic inflammatory disorders. The present study was designed to evaluate the effect of repeated short-term stress (RRS) on cellular transduction apart from oxidative burden and early tumour promotional biomarkers induced due to combined exposure of trichloroethylene (TCE) and Ultra-violet radiation (UVB). RRS leads to the increase in the expression of the stress responsive cellular transduction elements NFkB-p65 and activity of iNOS in the epidermal tissues of mice after toxicant exposure. RRS augments the steep depletion of the cellular antioxidant machinery which was evidenced by the marked depletion in GSH (Glutathione and GSH dependant enzymes), superoxide dismutase and catalase activity that were observed at significance level of P stressed animals and down regulation of DT-diaphorase activity (P short-term stress in the toxic response of TCE and UVB radiation.

  11. Active and realistic passive marijuana exposure tested by three immunoassays and GC/MS in urine

    Energy Technology Data Exchange (ETDEWEB)

    Mule, S.J.; Lomax, P.; Gross, S.J.

    1988-05-01

    Human urine samples obtained before and after active and passive exposure to marijuana were analyzed by immune kits (Roche, Amersham, and Syva) and gas chromatography/mass spectrometry (GC/MS). Seven of eight subjects were positive for the entire five-day test period with one immune kit. The latter correlated with GC/MS in 98% of the samples. Passive inhalation experiments under conditions likely to reflect realistic exposure resulted consistently in less than 10 ng/mL of cannabinoids. The 10-100-ng/mL cannabinoid concentration range essential for detection of occasional and moderate marijuana users is thus unaffected by realistic passive inhalation.

  12. Active and realistic passive marijuana exposure tested by three immunoassays and GC/MS in urine

    International Nuclear Information System (INIS)

    Mule, S.J.; Lomax, P.; Gross, S.J.

    1988-01-01

    Human urine samples obtained before and after active and passive exposure to marijuana were analyzed by immune kits (Roche, Amersham, and Syva) and gas chromatography/mass spectrometry (GC/MS). Seven of eight subjects were positive for the entire five-day test period with one immune kit. The latter correlated with GC/MS in 98% of the samples. Passive inhalation experiments under conditions likely to reflect realistic exposure resulted consistently in less than 10 ng/mL of cannabinoids. The 10-100-ng/mL cannabinoid concentration range essential for detection of occasional and moderate marijuana users is thus unaffected by realistic passive inhalation

  13. Repeated exposure to enhanced UV-B radiation in successive generations increases developmental instability (leaf fluctuating asymmetry) in a desert annual

    International Nuclear Information System (INIS)

    Midgley, G.F.; Wand, S.J.E.; Musil, C.F.

    1998-01-01

    Populations of the desert annual Dimorphotheca sinuata, derived from a common seed stock, were exposed concurrently over four successive generations to either ambient (representing no stratospheric ozone depletion) or elevated (representing 20% stratospheric ozone depletion) UV-B levels during their complete life cycle. Leaf fluctuating asymmetry (FA) was measured in populations of plants grown from seeds of selected generations which had experienced different UV-B exposure histories, and from seeds collected from a wild population of this species which grows in a naturally enhanced UV-B environment. These measured plants had been grown in a greenhouse under essentially UV-B-free conditions. Leaf FA was significantly increased by greater numbers of enhanced UV-B exposures in the parentage of the seed. There was a linear to exponential dose–response relationship between number of UV-B exposure iterations in seed parentage and leaf FA, suggesting that damage to DNA caused by UV-B exposure during plant development may not be fully repaired, and thus be inherited by offspring and accumulated over successive generations in this species. Leaf FA of plants grown from seed from the wild population was not significantly greater than that of control plants whose parentage experienced only ambient UV-B exposures, although this negative result may have been due to low sampling intensity and measurement resolution, and the relatively low UV-B enhancement experienced by the wild population. We conclude that leaf FA may constitute a relatively sensitive yet inexpensive means of quantifying UV-B damage to plants. (author)

  14. Passive cannabis smoke exposure and oral fluid testing. II. Two studies of extreme cannabis smoke exposure in a motor vehicle.

    Science.gov (United States)

    Niedbala, R Sam; Kardos, Keith W; Fritch, Dean F; Kunsman, Kenneth P; Blum, Kristen A; Newland, Gregory A; Waga, Joe; Kurtz, Lisa; Bronsgeest, Matth; Cone, Edward J

    2005-10-01

    ng/mL cutoff), and analyzed by GC-MS-MS for THCCOOH (LOD/LOQ = 1.0 ng/mL). Peak oral fluid THC concentrations in passive subjects recorded at the end of cannabis smoke exposure were up to 7.5 ng/mL (Study 1) and 1.2 ng/mL (Study 2). Thereafter, THC concentrations quickly declined to negative levels within 30-45 min in Study 1. It was found that environmentally exposed Collectors contained 3-14 ng/mL in Study 1. When potential contamination during collection was eliminated in Study 2, all passive subjects were negative at screening/confirmation cutoff concentrations throughout the study. Oral fluid specimens from active smokers had peak concentrations of THC approximately 100-fold greater than passive subjects in both studies. Positive oral fluid results were observed for active smokers 0-8 h. Urine analysis confirmed oral fluid results. These studies clarify earlier findings on the effects of passive cannabis smoke on oral fluid results. Oral fluid specimens collected in the presence of cannabis smoke appear to have been contaminated, thereby falsely elevating THC concentrations in oral fluid. The risk of a positive test for THC was virtually eliminated when specimens were collected in the absence of THC smoke.

  15. Estimation of the Altai region population exposure resulting from the nuclear tests at the Semipalatinsk test site

    International Nuclear Information System (INIS)

    Djachenko, V.I.; Gabbasov, M.N.; Laborev, V.M.; Markovtsev, A.S.; Sudakov, V.V.; Volobuyev, N.M.; Zelenov, V.I.; Lagutin, A.A.; Shoikher, J.N.

    1998-01-01

    The historical roots of reconstruction of doses received by populations from nuclear tests date back to the 60''s, when the world faced a problem of growing radioactive contamination by radioactive fallout resulting from atmospheric nuclear tests. Since then, only one aspect of this problem has been properly developed, namely: public-exposure doses resulting from the global radioactive fallout have been estimated. Local fallout, which occurred mainly in the territories of the test sites and regions adjacent to their boundaries, was considered and studied as an internal affair of the states. The first steps in creating the above-mentioned methodological basis were taken in Russia, where, by now, the methodology of dose estimation in regions of local radioactive fallout has been determined and acknowledged nationwide as a standard document (Federal Committee on Sanitay Epidemiological Control of RF, 1994). It was this methodology that was used for calculations and dose estimation of the exposure of the Altai population from the Semipalatinsk Test Site (STS). (orig./GL)

  16. Design of Fire/Gas Penetration Seals and fire exposure tests for Tokamak Fusion Test Reactor experimental areas

    International Nuclear Information System (INIS)

    Cavalluzzo, S.

    1983-01-01

    A Fire/Gas Penetration Seal is required in every penetration through the walls and ceilings into the Test Cell housing the Tokamak Fusion Test Reactor (TFTR), as well as other adjacent areas to protect the TFTR from fire damage. The penetrations are used for field coil lead stems, diagnostics systems, utilities, cables, trays, mechanical devices, electrical conduits, vacuum liner, air conditioning ducts, water pipes, and gas pipes. The function of the Fire/Gas Penetration Seals is to prevent the passage of fire and products of combustion through penetrations for a period of time up to three hours and remain structurally intact during fire exposure. The Penetration Seal must withstand, without rupture, a fire hose water stream directed at the hot surface. There are over 3000 penetrations ranging in size from several square inches to 100 square feet, and classified into 90 different types. The material used to construct the Fire/Gas Penetration Seals consist of a single and a two-component room temperature vulcanizing (RTV) silicone rubber compound. Miscellaneous materials such as alumina silica refractory fibers in board, blanket and fiber forms are also used in the construction and assembly of the Seals. This paper describes some of the penetration seals and the test procedures used to perform the three-hour fire exposure tests to demonstrate the adequacy of the seals

  17. The relationship of thyroid cancer with radiation exposure from nuclear weapon testing in the Marshall Islands.

    Science.gov (United States)

    Takahashi, Tatsuya; Schoemaker, Minouk J; Trott, Klaus R; Simon, Steven L; Fujimori, Keisei; Nakashima, Noriaki; Fukao, Akira; Saito, Hiroshi

    2003-03-01

    The US nuclear weapons testing program in the Pacific conducted between 1946 and 1958 resulted in radiation exposure in the Marshall Islands. The potentially widespread radiation exposure from radio-iodines of fallout has raised concerns about the risk of thyroid cancer in the Marshallese population. The most serious exposures and its health hazards resulted from the hydrogen-thermonuclear bomb test, the Castle BRAVO, on March 1, 1954. Between 1993 and 1997, we screened 3,709 Marshallese for thyroid disease who were born before the BRAVO test. It was 60% of the entire population at risk and who were still alive at the time of our examinations. We diagnosed 30 thyroid cancers and found 27 other study participants who had been operated for thyroid cancer before our screening in this group. Fifty-seven Marshallese born before 1954 (1.5%) had thyroid cancer or had been operated for thyroid cancer. Nearly all (92%) of these cancers were papillary carcinoma. We derived estimates of individual thyroid dose proxy from the BRAVO test in 1954 on the basis of published age-specific doses estimated on Utirik atoll and 137Cs deposition levels on the atolls where the participants came from. There was suggestive evidence that the prevalence of thyroid cancer increased with category of estimated dose to the thyroid.

  18. The relationship of thyroid cancer with radiation exposure from nuclear weapon testing in the Marshall Islands

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Tatsuya; Fukao, Akira [Yamagata Univ. (Japan). School of Medicine; Schoemaker, M.J. [Inst. of Cancer Research, Sutton, Surry (United Kingdom); Trott, K.R. [Gray Cancer Inst., Northwood, Middlesex (United Kingdom); Simon, S.L. [National Cancer Inst., Rockville, MD (United States); Fujimori, Keisei; Nakashima, Noriaki [Tohoku Univ., Sendai (Japan). Graduate School of Medicine; Saito, Hiroshi [Nagasaki Univ. (Japan). School of Medicine

    2003-03-01

    The US nuclear weapons testing program in the Pacific conducted between 1946 and 1958 resulted in radiation exposure in the Marshall Islands. The potentially widespread radiation exposure from radioiodines of fallout has raised concerns about the risk of thyroid cancer in the Marshallese population. The most serious exposures and its health hazards resulted from the hydrogen-thermonuclear bomb test, the Castle BRAVO, on March 1, 1954. Between 1993 and 1997, we screened 3,709 Marshallese for thyroid disease who were born before the BRAVO test. It was 60% of the entire population at risk and who were still alive at the time of our examinations. We diagnosed 30 thyroid cancers and found 27 other study participants who had been operated for thyroid cancer before our screening in this group. Fifty-seven Marshallese born before 1954 (1.5%) had thyroid cancer or had been operated for thyroid cancer. Nearly all (92%) of these cancers were papillary carcinoma. We derived estimates of individual thyroid dose proxy from the BRAVO test in 1954 on the basis of published age-specific doses estimated on Utirik atoll and {sup 137}Cs deposition levels on the atolls where the participants came from. There was suggestive evidence that the prevalence of thyroid cancer increased with category of estimated dose to the thyroid. (author)

  19. The relationship of thyroid cancer with radiation exposure from nuclear weapon testing in the Marshall Islands

    International Nuclear Information System (INIS)

    Takahashi, Tatsuya; Fukao, Akira; Trott, K.R.; Simon, S.L.; Fujimori, Keisei; Nakashima, Noriaki; Saito, Hiroshi

    2003-01-01

    The US nuclear weapons testing program in the Pacific conducted between 1946 and 1958 resulted in radiation exposure in the Marshall Islands. The potentially widespread radiation exposure from radioiodines of fallout has raised concerns about the risk of thyroid cancer in the Marshallese population. The most serious exposures and its health hazards resulted from the hydrogen-thermonuclear bomb test, the Castle BRAVO, on March 1, 1954. Between 1993 and 1997, we screened 3,709 Marshallese for thyroid disease who were born before the BRAVO test. It was 60% of the entire population at risk and who were still alive at the time of our examinations. We diagnosed 30 thyroid cancers and found 27 other study participants who had been operated for thyroid cancer before our screening in this group. Fifty-seven Marshallese born before 1954 (1.5%) had thyroid cancer or had been operated for thyroid cancer. Nearly all (92%) of these cancers were papillary carcinoma. We derived estimates of individual thyroid dose proxy from the BRAVO test in 1954 on the basis of published age-specific doses estimated on Utirik atoll and 137 Cs deposition levels on the atolls where the participants came from. There was suggestive evidence that the prevalence of thyroid cancer increased with category of estimated dose to the thyroid. (author)

  20. No effects of power line frequency extremely low frequency electromagnetic field exposure on selected neurobehavior tests of workers inspecting transformers and distribution line stations versus controls.

    Science.gov (United States)

    Li, Li; Xiong, De-fu; Liu, Jia-wen; Li, Zi-xin; Zeng, Guang-cheng; Li, Hua-liang

    2014-03-01

    We aimed to evaluate the interference of 50 Hz extremely low frequency electromagnetic field (ELF-EMF) occupational exposure on the neurobehavior tests of workers performing tour-inspection close to transformers and distribution power lines. Occupational short-term "spot" measurements were carried out. 310 inspection workers and 300 logistics staff were selected as exposure and control. The neurobehavior tests were performed through computer-based neurobehavior evaluation system, including mental arithmetic, curve coincide, simple visual reaction time, visual retention, auditory digit span and pursuit aiming. In 500 kV areas electric field intensity at 71.98% of total measured 590 spots were above 5 kV/m (national occupational standard), while in 220 kV areas electric field intensity at 15.69% of total 701 spots were above 5 kV/m. Magnetic field flux density at all the spots was below 1,000 μT (ICNIRP occupational standard). The neurobehavior score changes showed no statistical significance. Results of neurobehavior tests among different age, seniority groups showed no significant changes. Neurobehavior changes caused by daily repeated ELF-EMF exposure were not observed in the current study.