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Sample records for repeated stress exposure

  1. Hippocampal ER stress and learning deficits following repeated pyrethroid exposure.

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    Hossain, Muhammad M; DiCicco-Bloom, Emanuel; Richardson, Jason R

    2015-01-01

    Endoplasmic reticulum (ER) stress is implicated as a significant contributor to neurodegeneration and cognitive dysfunction. Previously, we reported that the widely used pyrethroid pesticide deltamethrin causes ER stress-mediated apoptosis in SK-N-AS neuroblastoma cells. Whether or not this occurs in vivo remains unknown. Here, we demonstrate that repeated deltamethrin exposure (3 mg/kg every 3 days for 60 days) causes hippocampal ER stress and learning deficits in adult mice. Repeated exposure to deltamethrin caused ER stress in the hippocampus as indicated by increased levels of C/EBP-homologous protein (131%) and glucose-regulated protein 78 (96%). This was accompanied by increased levels of caspase-12 (110%) and activated caspase-3 (50%). To determine whether these effects resulted in learning deficits, hippocampal-dependent learning was evaluated using the Morris water maze. Deltamethrin-treated animals exhibited profound deficits in the acquisition of learning. We also found that deltamethrin exposure resulted in decreased BrdU-positive cells (37%) in the dentate gyrus of the hippocampus, suggesting potential impairment of hippocampal neurogenesis. Collectively, these results demonstrate that repeated deltamethrin exposure leads to ER stress, apoptotic cell death in the hippocampus, and deficits in hippocampal precursor proliferation, which is associated with learning deficits.

  2. Repeated trauma exposure does not impair distress reduction during imaginal exposure for posttraumatic stress disorder.

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    Jerud, Alissa B; Farach, Frank J; Bedard-Gilligan, Michele; Smith, Hillary; Zoellner, Lori A; Feeny, Norah C

    2017-08-01

    Based on experimental research on threat extinction, individuals exposed to repeated traumatic events may have impaired outcome in exposure therapy compared to those who have experienced a single trauma (Lang & McTeague, ). This study examined whether repeated trauma exposure predicts smaller changes in self-reported distress during imaginal exposure and worse outcomes for patients with posttraumatic stress disorder (PTSD). Adults (N = 116) with chronic PTSD received up to 10 sessions of prolonged exposure (PE) therapy. Trauma exposure was assessed via interview and number of traumatic events were summed for each participant. To examine reductions in distress during treatment, mean and peak values of distress during imaginal exposure were calculated for the first imaginal session (initial distress activation) and subsequent sessions (between-session change in distress). Change in PTSD symptoms from pre- to posttreatment and follow-up provided an additional index of outcome. In-session distress during imaginal exposure decreased over the course of treatment. PTSD symptoms also decreased over treatment, with gains being maintained through follow-up. Repeated trauma exposure was not significantly correlated with initial distress activation. Additionally, linear mixed-model analyses showed no significant association between repeated trauma exposure and between-session change in distress or PTSD symptoms. Contrary to recent speculation, repeated trauma exposure did not predict less change in self-reported distress during imaginal exposure or worse PTSD outcomes. The bench-to-bedside linkage of threat extinction to exposure therapy is discussed, noting strengths and weaknesses. Patients with repeated trauma exposure show reductions in distress with exposure treatment and benefit from PE as much as patients with single-exposure trauma histories. © 2016 Wiley Periodicals, Inc.

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

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    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.

  4. Within-session effect of repeated stress exposure on extinction circuitry function in social anxiety disorder.

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    Åhs, Fredrik; Gingnell, Malin; Furmark, Tomas; Fredrikson, Mats

    2017-03-30

    Anxiety reduction following repeated exposure to stressful experiences is generally held to depend on neural processes involved in extinction of conditioned fear. We predicted that repeated exposure to stressful experiences would change activity throughout the circuitry serving extinction, including ventromedial prefrontal cortex (vmPFC), the hippocampus and the amygdala. To test this prediction, 36 participants diagnosed with SAD performed two successive speeches in front of an observing audience while regional cerebral blood flow (rCBF) was recorded using positron emission tomography. To control for non-anxiolytic effects of repeated exposure, rCBF was also measured during repeated presentations of neutral and angry facial expressions. Results showed that anxiety ratings and heart rate decreased from the first to the second speech, indicating an anxiolytic effect of repeated exposure. Exposure attenuated rCBF in the amygdala whereas no change in rCBF was observed in the vmPFC or hippocampus. The rCBF-reductions in the amygdala were greater following repetition of the speech task than repetition of face exposure indicating that they were specific to anxiety attenuation and not due to a reduced novelty. Our findings suggest that amygdala-related attenuation processes are key to understanding the working mechanisms of exposure therapy.

  5. Perfectionism Affects Blood Pressure in Response to Repeated Exposure to Stress.

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    Albert, Phebe; Rice, Kenneth G; Caffee, Lauren

    2016-04-01

    This pilot study examined the effects of perfectionism on blood pressure (BP) in response to repeated exposure to mental arithmetic stressors. College students (N = 30) in a laboratory setting were administered a series of challenging mathematical tasks. BP was measured at baseline and after each task. Multilevel modelling analyses revealed that BP tended to decline over the course of the mathematical tasks. However, higher levels of performance standards predicted relatively stable levels of systolic BP, whereas moderate and lower levels of standards predicted declines in systolic BP. Higher levels of self-critical perfectionism predicted generally sustained levels of diastolic BP, with moderate and low self-criticism predicting declines in diastolic BP during the repeated stressors. These preliminary results suggest that students with higher levels of perfectionism may be at risk for physiological problems associated with stress reactivity, perhaps especially so in situations in which they experience persistent stress. Although results were qualified by a relatively small sample size, effects were statistically significant and supported the importance of examining the short-term and long-term implications of the effects of perfectionism on cardiovascular function and the different implications of elevations in systolic and diastolic BP.

  6. The development of behavioral and endocrine abnormalities in rats after repeated exposure to direct and indirect stress.

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    Daniels, Willie Mark Uren; de Klerk Uys, Joachim; van Vuuren, Petra; Stein, Daniel Joseph

    2008-04-01

    The present study compared the effects of direct and indirect stress on the behavior and hypothalamic-pituitary-adrenal axis of rats. Animals were placed in a two compartment box. In one compartment the direct stressed rat was subjected to electric foot shocks randomly applied for 10 minutes (0.5 mA of 1 s duration). In the adjacent compartment, the indirect stressed rats witnessed the application of these electric foot shocks. Our data showed substantial behavioral changes in the open field test, but limited effects in the elevated plus maze. The findings suggested that single and repeated stress exposure may have different consequences, that the effects of stress exposure may develop over time and persist for an extended period, and that both direct and indirect stressed rats displayed a hyposensitive HPA axis following acute restraint stress. Overall our observations moderately indicate direct exposure to elicit behavioral changes, and both direct and indirect exposure to stress to result in aberrations within the neuroendocrine system. With additional development our stress models may be considered for studying the complex interrelationship between an external stressor, and the experience of the organism.

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

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    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.

  8. Mediation of the Relationship between Maternal Phthalate Exposure and Preterm Birth by Oxidative Stress with Repeated Measurements across Pregnancy.

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    Ferguson, Kelly K; Chen, Yin-Hsiu; VanderWeele, Tyler J; McElrath, Thomas F; Meeker, John D; Mukherjee, Bhramar

    2017-03-01

    Mediation analysis is useful for understanding mechanisms and has been used minimally in the study of the environment and disease. We examined mediation of the association between phthalate exposure during pregnancy and preterm birth by oxidative stress. This nested case-control study of preterm birth (n = 130 cases, 352 controls) included women who delivered in Boston, Massachusestts, from 2006 through 2008. Phthalate metabolites and 8-isoprostane, an oxidative stress biomarker, were measured in urine from three visits in pregnancy. We applied four counterfactual mediation methods: method 1, utilizing exposure and mediator averages; method 2, using averages but allowing for an exposure-mediator interaction; method 3, incorporating longitudinal measurements of the exposure and mediator; and method 4, using longitudinal measurements and allowing for an exposure-mediator interaction. We observed mediation of the associations between phthalate metabolites and all preterm birth by 8-isoprostane, with the greatest estimated proportion mediated observed for spontaneous preterm births specifically. Fully utilizing repeated measures of the exposure and mediator improved precision of indirect (i.e., mediated) effect estimates, and including an exposure-mediator interaction increased the estimated proportion mediated. For example, for mono(2-ethyl-carboxy-propyl) phthalate (MECPP), a metabolite of di(2-ethylhexyl) phthalate (DEHP), the percent of the total effect mediated by 8-isoprostane increased from 47% to 60% with inclusion of an exposure-mediator interaction term, in reference to a total adjusted odds ratio of 1.67 or 1.48, respectively. This demonstrates mediation of the phthalate-preterm birth relationship by oxidative stress, and the utility of complex regression models in capturing mediated associations when repeated measures of exposure and mediator are available and an exposure-mediator interaction may exist. Citation: Ferguson KK, Chen YH, VanderWeele TJ, Mc

  9. Lipid Profile and Oxidative Stress Markers in Wistar Rats following Oral and Repeated Exposure to Fijk Herbal Mixture

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    Oluyomi Stephen Adeyemi

    2014-01-01

    Full Text Available This study determined the effect of the oral and repeated administration of Fijk herbal mixture on rat biochemical and morphological parameters. Twenty-four Wistar rats were distributed into four groups of 6. Group A served as control and received oral administration of distilled water daily. The experimental groups B, C, and D were daily and orally exposed to Fijk herbal mixture at 15, 30, and 45 mg/kg, respectively. Treatments lasted for 21 days. The rats were sacrificed under mild diethyl ether anesthesia 24 hr after cessation of treatment. The blood and liver samples were collected and used for the biochemical and morphological analyses. Oral exposure to Fijk caused elevated levels of rat plasma ALT, AST, triglycerides, LDL, and MDA. In contrast, rat plasma HDL, GSH, and ALP levels were lowered by Fijk oral exposure. Also, the herbal remedy caused a dose-dependent elevation in the plasma atherogenic index. The histopathology examinations of rat liver sections revealed inimical cellular alterations caused by repeated exposure to Fijk. Study provides evidence that oral and repeated exposure to Fijk in rats raised the atherogenic index and potentiated oxidative stress as well as hepatic injury.

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

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    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.

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

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

    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 D2 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.

  12. Response of the Hypothalamic-Pituitary-Adrenal System to Repeated Moderate Psychoemotional Stress Exposure Is Associated with Behavioral Parameters.

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    Goncharova, N D; Chigarova, O A; Oganyan, T E

    2017-05-01

    Individual features of the response of the hypothalamic-pituitary-adrenal axis (HPAA) to repeated moderate stress exposure (daily 2-h restraint stress for 10 days) was studied in young female rhesus monkeys with healthy normal behavior and combined group of female rhesus monkeys with abnormal depression-like and anxious behavior. No between-group differences in the response of ACTH and cortisol were found on day 1. On day 10, a rapid and less pronounced increase in ACTH secretion was observed in all animals in comparison with day 1. Analysis of between-group differences in HPAA response showed higher increase in ACTH level and lower increase in cortisol concentration in animals with depression-like and anxious behavior. These changes were similar to the previously described differences in the response of the adenohypophysis and adrenal cortex to acute restraint stress in old monkeys with similar behavior. Thus, individuals with depression-like and anxious behavior demonstrate impaired stress-induced reactivity of HPAA as early as in young age.

  13. Lactation-induced reduction in hippocampal neurogenesis is reversed by repeated stress exposure

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    Hillerer, K.M.; Neumann, I. D.; Couillard-Despres, S.; Aigner, L.; Slattery, D.A.

    2014-01-01

    The peripartum period is a time of high susceptibility for mood and anxiety disorders, some of which have recently been associated with alterations in hippocampal neurogenesis. Several factors including stress, aging, and, perhaps unexpectedly, lactation have been shown to decrease hippocampal neurogenesis. Intriguingly, lactation is also a time of reduced stress responsivity suggesting that the effect of stress on neurogenic processes may differ during this period. Therefore, the aim of the ...

  14. Exposure to repeated immobilization stress inhibits cocaine-induced increase in dopamine extracellular levels in the rat ventral tegmental area.

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    Sotomayor-Zárate, Ramón; Abarca, Jorge; Araya, Katherine A; Renard, Georgina M; Andrés, María E; Gysling, Katia

    2015-11-01

    A higher vulnerability to drug abuse has been observed in human studies of individuals exposed to chronic or persistent stress, as well as in animal models of drug abuse. Here, we explored the effect of repeated immobilization stress on cocaine-induced increase in dopamine extracellular levels in VTA and its regulation by corticotropin-releasing factor (CRF) and GABA systems. Cocaine (10mg/Kg i.p.) induced an increase of VTA DA extracellular levels in control rats. However, this effect was not observed in repeated stress rats. Considering the evidence relating stress with CRF, we decided to perfuse CRF and CP-154526 (selective antagonist of CRF1 receptor) in the VTA of control and repeated stress rats, respectively. We observed that perfusion of 20μM CRF inhibited the increase of VTA DA extracellular levels induced by cocaine in control rats. Interestingly, we observed that in the presence of 10μM CP-154526, cocaine induced a significant increase of VTA DA extracellular levels in repeated stress rats. Regarding the role of VTA GABA neurotransmission, cocaine administration induced a significant increase in VTA GABA extracellular levels only in repeated stress rats. Consistently, cocaine was able to increase VTA DA extracellular levels in repeated stress rats when 100μM bicuculline, an antagonist of GABAA receptor, was perfused intra VTA. Thus, both CRF and GABA systems are involved in the lack of response to cocaine in the VTA of repeated stress rats. It is tempting to suggest that the loss of response in VTA dopaminergic neurons to cocaine, after repeated stress, is due to an interaction between CRF and GABA systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Repeated exposure to heat stress results in a diaphragm phenotype that resists ventilator-induced diaphragm dysfunction.

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    Yoshihara, Toshinori; Ichinoseki-Sekine, Noriko; Kakigi, Ryo; Tsuzuki, Takamasa; Sugiura, Takao; Powers, Scott K; Naito, Hisashi

    2015-11-01

    Controlled mechanical ventilation (CMV) is a life-saving intervention for patients in respiratory failure. Unfortunately, prolonged mechanical ventilation (MV) results in diaphragmatic atrophy and contractile dysfunction, both of which are predicted to contribute to problems in weaning patients from the ventilator. Therefore, developing a strategy to protect the diaphragm against ventilator-induced weakness is important. We tested the hypothesis that repeated bouts of heat stress result in diaphragm resistance against CMV-induced atrophy and contractile dysfunction. Male Wistar rats were randomly divided into six experimental groups: 1) control; 2) single bout of whole body heat stress; 3) repeated bouts of whole body heat stress; 4) 12 h CMV; 5) single bout of whole body heat stress 24 h before CMV; and 6) repeated bouts of whole body heat stress 1, 3, and 5 days before 12 h of CMV. Our results revealed that repeated bouts of heat stress resulted in increased levels of heat shock protein 72 in the diaphragm and protection against both CMV-induced diaphragmatic atrophy and contractile dysfunction at submaximal stimulation frequencies. The specific mechanisms responsible for this protection remain unclear: this heat stress-induced protection against CMV-induced diaphragmatic atrophy and weakness may be partially due to reduced diaphragmatic oxidative stress, diminished activation of signal transducer/transcriptional activator-3, lower caspase-3 activation, and decreased autophagy in the diaphragm.

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

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    Mauritz, Maria W.; Van Gaal, Betsie G. I.; Jongedijk, Ruud A.; Schoonhoven, Lisette; Nijhuis-van der Sanden, Maria W. G.; Goossens, Peter J. J.

    2016-01-01

    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 enhance the

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

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    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

  18. Murine Model of Repeated Exposures to Conspecific Trained Aggressors Simulates Features of Post-Traumatic Stress Disorder

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    2012-07-20

    Rasmusson and Charney [95], Stam et al. [96], and Siegmund and Wotjak [6]. In our studies, the persis- tence of some acutely altered behaviors after...served in Iraq and Afghanistan: possible explanations. Journal of Traumatic Stress 2010;23:59–68. [6] Siegmund A, Wotjak CT. Toward an animal model...Posttraumatic Stress Disorder (PTSD). Behavioural Brain Research 2009;205:544–9. ral BrR. Hammamieh et al. / Behaviou [11] Siegmund A, Dahlhoff M, Habersetzer

  19. Physiological consequences of repeated exposures to conditioned fear.

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    Thompson, Robert S; Strong, Paul V; Fleshner, Monika

    2012-06-01

    Activation of the stress response evokes a cascade of physiological reactions that may be detrimental when repeated or chronic, and when triggered after exposure to psychological/emotional stressors. Investigation of the physiological mechanisms responsible for the health damaging effects requires animal paradigms that repeatedly evoke a response to psychological/emotional stressors. To this end, adult male Sprague Dawley rats were repeatedly exposed (2X per day for 20 days) to a context that they were conditioned to fear (conditioned fear test, CFT). Repeated exposure to CFT produced body weight loss, adrenal hypertrophy, thymic involution, and basal corticosterone elevation. In vivo biotelemetry measures revealed that CFT evokes sympathetic nervous system driven increases in heart rate (HR), mean arterial pressure (MAP), and core body temperature. Extinction of behavioral (freezing) and physiological responses to CFT was prevented using minimal reinstatement footshock. MAP responses to the CFT did not diminish across 20 days of exposure. In contrast, HR and cardiac contractility responses declined by day 15, suggesting a shift toward vascular-dominated MAP (a pre-clinical marker of CV dysfunction). Flattened diurnal rhythms, common to stress-related mood/anxiety disorders, were found for most physiological measures. Thus, repeated CFT produces adaptations indicative of the health damaging effects of psychological/emotional stress.

  20. Physiological Consequences of Repeated Exposures to Conditioned Fear

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    Robert S. Thompson

    2012-05-01

    Full Text Available Activation of the stress response evokes a cascade of physiological reactions that may be detrimental when repeated or chronic, and when triggered after exposure to psychological/emotional stressors. Investigation of the physiological mechanisms responsible for the health damaging effects requires animal paradigms that repeatedly evoke a response to psychological/emotional stressors. To this end, adult male Sprague Dawley rats were repeatedly exposed (2X per day for 20 days to a context that they were conditioned to fear (conditioned fear test, CFT. Repeated exposure to CFT produced body weight loss, adrenal hypertrophy, thymic involution, and basal corticosterone elevation. In vivo biotelemetry measures revealed that CFT evokes sympathetic nervous system driven increases in heart rate (HR, mean arterial pressure (MAP, and core body temperature. Extinction of behavioral (freezing and physiological responses to CFT was prevented using minimal reinstatement footshock. MAP responses to the CFT did not diminish across 20 days of exposure. In contrast, HR and cardiac contractility responses declined by day 15, suggesting a shift toward vascular-dominated MAP (a pre-clinical marker of CV dysfunction. Flattened diurnal rhythms, common to stress-related mood/anxiety disorders, were found for most physiological measures. Thus, repeated CFT produces adaptations indicative of the health damaging effects of psychological/emotional stress.

  1. Repeatedly stressed rats have enhanced vulnerability to amygdala kindling epileptogenesis.

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    Jones, Nigel C; Lee, Han Ee; Yang, Meng; Rees, Sandra M; Morris, Margaret J; O'Brien, Terence J; Salzberg, Michael R

    2013-02-01

    Psychiatric disorders associated with elevated stress levels, such as depression, are present in many epilepsy patients, including those with mesial Temporal Lobe Epilepsy (mTLE). Evidence suggests that these psychiatric disorders can predate the onset of epilepsy, suggesting a causal/contributory role. Prolonged exposure to elevated corticosterone, used as a model of chronic stress/depression, accelerates limbic epileptogenesis in the amygdala kindling model. The current study examined whether exposure to repeated stress could similarly accelerate experimental epileptogenesis. Female adult non-epileptic Wistar rats were implanted with a bipolar electrode into the left amygdala, and were randomly assigned into stressed (n=18) or non-stressed (n=19) groups. Rats underwent conventional amygdala kindling (two electrical stimulations per day) until 5 Class V seizures had been experienced ('the fully kindled state'). Stressed rats were exposed to 30min restraint immediately prior to each kindling stimulation, whereas non-stressed rats received control handling. Restraint stress increased circulating corticosterone levels (pre-stress: 122±17ng/ml; post-stress: 632±33ng/ml), with no habituation observed over the experiment. Stressed rats reached the 'fully kindled state' in significantly fewer stimulations than non-stressed rats (21±1 vs 33±3 stimulations; p=0.022; ANOVA), indicative of a vulnerability to epileptogenesis. Further, seizure durations were significantly longer in stressed rats (p<0.001; ANOVA). These data demonstrate that exposure to repeated experimental stress accelerates the development of limbic epileptogenesis, an effect which may be related to elevated corticosterone levels. This may have implications for understanding the effects of chronic stress and depression in disease onset and progression of mTLE in humans.

  2. Post-stress rumination predicts HPA axis responses to repeated acute stress.

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    Gianferante, Danielle; Thoma, Myriam V; Hanlin, Luke; Chen, Xuejie; Breines, Juliana G; Zoccola, Peggy M; Rohleder, Nicolas

    2014-11-01

    Failure of the hypothalamus-pituitary-adrenal (HPA) axis to habituate to repeated stress exposure is related with adverse health outcomes, but our knowledge of predictors of non-habituation is limited. Rumination, defined as repetitive and unwanted past-centered negative thinking, is related with exaggerated HPA axis stress responses and poor health outcomes. The aim of this study was to test whether post-stress rumination was related with non-habituation of cortisol to repeated stress exposure. Twenty-seven participants (n=13 females) were exposed to the Trier Social Stress Test (TSST) twice on consecutive afternoons. Post-stress rumination was measured after the first TSST, and HPA axis responses were assessed by measuring salivary cortisol 1 min before, and 1, 10, 20, 60, and 120 min after both TSSTs. Stress exposure induced HPA axis activation on both days, and this activation showed habituation indicated by lower responses to the second TSST (F=3.7, p=0.015). Post-stress rumination after the first TSST was associated with greater cortisol reactivity after the initial stress test (r=0.45, pHPA axis responses. This finding implicates rumination as one possible mechanism mediating maladaptive stress response patterns, and it might also offer a pathway through which rumination might lead to negative health outcomes.

  3. Blocking glucocorticoid receptors at adolescent age prevents enhanced freezing between repeated cue-exposures after conditioned fear in adult mice raised under chronic early life stress

    NARCIS (Netherlands)

    Arp, J.M.; ter Horst, J.P.; Loi, M.; den Blaauwen, J.; Bangert, E.L.; Fernández, G.; Joëls, M.; Oitzl, M.S.; Krugers, H.J.

    2016-01-01

    Early life adversity can have long-lasting impact on learning and memory processes and increase the risk to develop stress-related psychopathologies later in life. In this study we investigated i) how chronic early life stress (ELS) - elicited by limited nesting and bedding material from postnatal

  4. Blocking glucocorticoid receptors at adolescent age prevents enhanced freezing between repeated cue-exposures after conditioned fear in adult mice raised under chronic early life stress

    NARCIS (Netherlands)

    Marit Arp, J; Ter Horst, Judith P; Loi, Manila; den Blaauwen, Jan; Bangert, Eline; Fernández, Guillén; Joëls, Marian; Oitzl, Melly S; Krugers, Harm

    2016-01-01

    Early life adversity can have long-lasting impact on learning and memory processes and increase the risk to develop stress-related psychopathologies later in life. In this study we investigated i) how chronic early life stress (ELS) - elicited by limited nesting and bedding material from postnatal d

  5. Blocking glucocorticoid receptors at adolescent age prevents enhanced freezing between repeated cue-exposures after conditioned fear in adult mice raised under chronic early life stress

    NARCIS (Netherlands)

    Arp, J.M.; Horst, J.P. ter; Loi, M.; Blaauwen, J. den; Bangert, E.; Fernandez, G.S.E.; Joels, M.; Oitzl, M.S.; Krugers, H.J.

    2016-01-01

    Early life adversity can have long-lasting impact on learning and memory processes and increase the risk to develop stress-related psychopathologies later in life. In this study we investigated (i) how chronic early life stress (ELS) - elicited by limited nesting and bedding material from postnatal

  6. Blocking glucocorticoid receptors at adolescent age prevents enhanced freezing between repeated cue-exposures after conditioned fear in adult mice raised under chronic early life stress

    NARCIS (Netherlands)

    Arp, J.M.; ter Horst, J.P.; Loi, M.; den Blaauwen, J.; Bangert, E.L.; Fernández, G.; Joëls, M.; Oitzl, M.S.; Krugers, H.J.

    2016-01-01

    Early life adversity can have long-lasting impact on learning and memory processes and increase the risk to develop stress-related psychopathologies later in life. In this study we investigated i) how chronic early life stress (ELS) - elicited by limited nesting and bedding material from postnatal d

  7. Blocking glucocorticoid receptors at adolescent age prevents enhanced freezing between repeated cue-exposures after conditioned fear in adult mice raised under chronic early life stress

    NARCIS (Netherlands)

    Arp, J.M.; Horst, J.P. ter; Loi, M.; Blaauwen, J. den; Bangert, E.; Fernandez, G.S.E.; Joels, M.; Oitzl, M.S.; Krugers, H.J.

    2016-01-01

    Early life adversity can have long-lasting impact on learning and memory processes and increase the risk to develop stress-related psychopathologies later in life. In this study we investigated (i) how chronic early life stress (ELS) - elicited by limited nesting and bedding material from postnatal

  8. Modeling repeated measurement data for occupational exposure assessment and epidemiology

    NARCIS (Netherlands)

    Peretz, Chava

    2004-01-01

    Repeated measurements designs, occur frequently in the assessment of exposure to toxic chemicals. This thesis deals with the possibilities of using mixed effects models for occupational exposure assessment and in the analysis of exposure response relationships. The model enables simultaneous estima

  9. Repeated swim stress alters brain benzodiazepine receptors measured in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.

    1989-06-01

    The effects of repeated swim stress on brain benzodiazepine receptors were examined in the mouse using both an in vivo and in vitro binding method. Specific in vivo binding of (/sup 3/H)Ro15-1788 to benzodiazepine receptors was decreased in the hippocampus, cerebral cortex, hypothalamus, midbrain and striatum after repeated swim stress (7 consecutive days of daily swim stress) when compared to nonstressed mice. In vivo benzodiazepine receptor binding was unaltered after repeated swim stress in the cerebellum and pons medulla. The stress-induced reduction in in vivo benzodiazepine receptor binding did not appear to be due to altered cerebral blood flow or to an alteration in benzodiazepine metabolism or biodistribution because there was no difference in (14C)iodoantipyrine distribution or whole brain concentrations of clonazepam after repeated swim stress. Saturation binding experiments revealed a change in both apparent maximal binding capacity and affinity after repeated swim stress. Moreover, a reduction in clonazepam's anticonvulsant potency was also observed after repeated swim stress (an increase in the ED50 dose for protection against pentylenetetrazol-induced seizures), although there was no difference in pentylenetetrazol-induced seizure threshold between the two groups. In contrast to the results obtained in vivo, no change in benzodiazepine receptor binding kinetics was observed using the in vitro binding method. These data suggest that environmental stress can alter the binding parameters of the benzodiazepine receptor and that the in vivo and in vitro binding methods can yield substantially different results.

  10. Cataract after repeated daily in vivo exposure to ultraviolet radiation.

    Science.gov (United States)

    Galichanin, Konstantin; Löfgren, Stefan; Söderberg, Per

    2014-12-01

    Epidemiological data indicate a correlation between lifelong exposure to ultraviolet radiation and cortical cataract. However, there is no quantitative experimental data on the effect of daily repeated in vivo exposures of the eye to UVR. Therefore, this experiment was designed to verify whether the dose additivity for UVR exposures holds through periods of time up to 30 d. Eighty rats were conditioned to a rat restrainer 5 d prior to exposure. All animals were divided into four exposure period groups of 1, 3, 10, and 30 d of exposure to UVR. Each exposure period group of 20 animals was randomly divided into five cumulated UVR dose subgroups. Eighteen-wk-old non-anesthetized albino Sprague-Dawley rats were exposed daily to UVR-300 nm for 15 min. One week after the last exposure, animals were sacrificed. The lenses were extracted for macroscopic imaging of dark-field anatomy, and degree of cataract was quantified by measurement of the intensity of forward lens light scattering. Maximum tolerable dose (MTD(2.3:16)), a statistically defined standard for sensitivity for the threshold for UVR cataract, was estimated for each exposure period. Exposed lenses developed cataract with varying appearance on the anterior surface. Single low doses of UVR accumulated to cause cataract during periods up to 30 d. MTD(2.3:16) for 1, 3, 10, and 30 d of repeated exposures was estimated to 4.70, 4.74, 4.80, and 6.00 kJ m(-2), respectively. In conclusion, the lens sensitivity to UVR-B for 18-wk-old Sprague-Dawley rats decreases with the increasing number of days being exposed.

  11. Physiological responses to repeated stress in individuals with high and low trait resilience.

    Science.gov (United States)

    Lü, Wei; Wang, Zhenhong; You, Xuqun

    2016-10-01

    This study examined individual differences in trait resilience in physiological recovery from, and physiological habituation to, repeated stress (i.e. public speaking). Eighty-two college students were categorized as either high (n=40) or low (n=42) on trait resilience, based on the scores of the Connor-Davidson Resilience Scale (CD-RISC). Subjective and physiological data were collected from participants across seven laboratory stages: baseline, stress anticipation 1, stress 1, post-stress 1, stress anticipation 2, stress 2, and post-stress 2. Results indicated that high-trait-resilient participants exhibited more complete heart rate (HR), systolic and diastolic blood pressure (SBP, DBP) recovery from the first and second stress anticipation exposures as compared to low-trait-resilient participants. High-trait-resilient participants demonstrated higher resting respiratory sinus arrhythmia (RSA) coupled with more complete RSA recovery from the first and second stress anticipation exposures as compared to their low-trait-resilient counterparts. Moreover, high-trait-resilient participants exhibited pronounced SBP and DBP habituation across two successive stress anticipation exposures, with greater decreases in SBP and DBP reactivity to recurrent stress anticipation as compared to the low-trait-resilient participants. These findings suggest an adaptive physiological response pattern to recurrent stress in high-trait-resilient individuals. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Prolonged Exposure Therapy For Post Traumatic Stress Disorder

    Directory of Open Access Journals (Sweden)

    Levent SÜTÇİGİL

    2012-07-01

    Full Text Available Post-traumatic Stress Disorder (PTSD is a psychiatric illness that usually develops after an event that threatens one’s life and body integrity and it affects quality of life and impairs social functioning significantly. Many studies have shown therapeutic effect of cognitive behavioral therapies on posttraumatic stress disorder, so that these therapies take part in the first step of treatment guides. Exposure is a practice that is generally used to reduce pathological fear and related emotions common in posttraumatic stress disorder (PTSD and other anxiety disorders. During exposure, patients intentionally confront with feared objects, situations, thoughts and similar stimuli in order to reduce anxiety level. Exposure can be divided into two main techniques as in vivo exposure and imaginal exposure. Prolonged exposure therapy is a specialized treatment program configured for the treatment of posttraumatic stress disorder and it is based on emotional processing theory. Program is comprised of four main components: (a Psycho-education about trauma and posttraumatic disorders, (b Training for breathing exercises, (c repeated facing with objects, persons, situations and thoughts which causes re-experience about trauma, (d Patient are instructed for telling repeatedly and loudly about traumatic experiences . Prolonged exposure usually involves 9 to 12 sessions, each lasting about 60-90 minutes, administered once or twice a week. Prolonged exposure therapy was started to be implemented since the 1980s, during this period the effectiveness of the therapy has been shown in various empirical studies.

  13. Influence of repeated daily diving on decompression stress.

    Science.gov (United States)

    Zanchi, J; Ljubkovic, M; Denoble, P J; Dujic, Z; Ranapurwala, S; Pollock, N W

    2014-06-01

    Acclimatization (an adaptive change in response to repeated environmental exposure) to diving could reduce decompression stress. A decrease in post-dive circulating venous gas emboli (VGE or bubbles) would represent positive acclimatization. The purpose of this study was to determine whether four days of daily diving alter post-dive bubble grades. 16 male divers performed identical no-decompression air dives on 4 consecutive days to 18 meters of sea water for 47 min bottom times. VGE monitoring was performed with transthoracic echocardiography every 20 min for 120 min post-dive. Completion of identical daily dives resulted in progressively decreasing odds (or logit risk) of having relatively higher grade bubbles on consecutive days. The odds on Day 4 were half that of Day 1 (OR 0.50, 95% CI: 0.34, 0.73). The odds ratio for a >III bubble grade on Day 4 was 0.37 (95% CI: 0.20, 0.70) when compared to Day 1. The current study indicates that repetitive daily diving may reduce bubble formation, representing a positive (protective) acclimatization to diving. Further work is required to evaluate the impact of additional days of diving and multiple dive days and to determine if the effect is sufficient to alter the absolute risk of decompression sickness.

  14. Repeated stress increases catalytic TrkB mRNA in rat hippocampus.

    Science.gov (United States)

    Nibuya, M; Takahashi, M; Russell, D S; Duman, R S

    1999-05-28

    Northern blot analysis was utilized to distinguish between catalytic and truncated TrkB mRNA on the basis of transcript size. Repeated (10 days), but not acute, immobilization stress significantly increased levels of catalytic TrkB mRNA, but did not influence expression of truncated TrkB transcripts in rat hippocampus. Exposure to another paradigm, a combination of different, unpredictable stressors, also increased levels of catalytic, but not truncated, TrkB mRNA. In situ hybridization analysis demonstrated that chronic stress up-regulated TrkB mRNA in CA1 and CA3 pyramidal and dentate gyrus granule cells layers of hippocampus. As previously reported, both acute and chronic immobilization stress decreased expression of BDNF mRNA, suggesting that up-regulation of catalytic TrkB mRNA may be a compensatory adaptation to repeated stress.

  15. Contrasting effects of diazepam and repeated restraint stress on latent inhibition in mice.

    Science.gov (United States)

    Mongeau, Raymond; Marcello, Stefania; Andersen, Jacob Sparre; Pani, Luca

    2007-11-02

    The effects on latent inhibition (LI; a delay in conditioning when a CS has been pre-exposed without consequences) of repeated restraint stress and the anxiolytic drug diazepam were examined in C57BL/6 mice to know whether previous aversive events or anxiolysis are factors determining the expression of LI. The LI model was optimized for this strain particularly sensitive to stress (using both the CER and the conditioned freezing procedures) and characterized with typical (haloperidol) and atypical (clozapine and olanzapine) antipsychotic drugs administered either during the conditioning or the pre-exposure phases. An acute challenge with amphetamine, a dopamine releaser, was done to verify the enhancement of hyperactivity in C57BL/6 mice after the restraint stress sensitization. At all doses tested, diazepam decreased latent inhibition when administered during the pre-exposure phase (similarly to atypical antipsychotic drugs). Repeated restraint stress enhanced LI by blocking the CS-induced freezing in pre-exposed mice. In contrast, pre-treatment with diazepam before pre-exposure allowed the expression of CS-induced freezing in stressed mice pre-exposed to the tone. It is suggested that stress and anxiolytic drugs can have opposite effects on attention or perseveration processes during learning of conflicting contingency responses.

  16. Enhanced resistance to UV-B radiation in Anabaena sp. PCC 7120 (Cyanophyceae) by repeated exposure.

    Science.gov (United States)

    Qin, Hongjie; Li, Dunhai

    2014-07-01

    In natural habitats, organisms especially phytoplankton are not always continuously subjected to ultraviolet-B radiation (UVBR). By simulation of the natural situation, the N2-fixing cyanobacterium Anabaena sp. PCC 7120 was subjected to UV-B exposure and recovery cycles. A series of morphological and physiological changes were observed in Anabaena sp. PCC 7120 under repeated UVBR when compared with controls. Such as the breakage of filaments, intervals between heterocysts, heterocyst frequency, total carbohydrate, and carotenoids were increased, while the nitrogenase activity and photosynthetic activity were inhibited by repeated UVBR; however, these activities could recover when UV-B stress was removed. Unexpectedly, the over-compensatory growth was observed at the end of the second round of exposure and recovery cycle. Our results showed that discontinuous UVBR could increase the growth rate and the tolerance as well as repair capacity of Anabaena sp. PCC 7120. These results indicate that moderate UVBR may increase the growth of cyanobacteria in natural habitats.

  17. Activation of physiological stress responses by a natural reward: Novel vs. repeated sucrose intake.

    Science.gov (United States)

    Egan, Ann E; Ulrich-Lai, Yvonne M

    2015-10-15

    Pharmacological rewards, such as drugs of abuse, evoke physiological stress responses, including increased heart rate and blood pressure, and activation of the hypothalamic-pituitary-adrenal (HPA) axis. It is not clear to what extent the natural reward of palatable foods elicits similar physiological responses. In order to address this question, HPA axis hormones, heart rate, blood pressure and brain pCREB immunolabeling were assessed following novel and repeated sucrose exposure. Briefly, adult, male rats with ad libitum food and water were given either a single (day 1) or repeated (twice-daily for 14 days) brief (up to 30 min) exposure to a second drink bottle containing 4 ml of 30% sucrose drink vs. water (as a control for bottle presentation). Sucrose-fed rats drank more than water-fed on all days of exposure, as expected. On day 1 of exposure, heart rate, blood pressure, plasma corticosterone, and locomotion were markedly increased by presentation of the second drink bottle regardless of drink type. After repeated exposure (day 14), these responses habituated to similar extents regardless of drink type and pCREB immunolabeling in the hypothalamic paraventricular nucleus (PVN) also did not vary with drink type, whereas basolateral amygdala pCREB was increased by sucrose intake. Taken together, these data suggest that while sucrose is highly palatable, physiological stress responses were evoked principally by the drink presentation itself (e.g., an unfamiliar intervention by the investigators), as opposed to the palatability of the offered drink.

  18. Repeated Ketamine Exposure Induces an Enduring Resilient Phenotype in Adolescent and Adult Rats

    Science.gov (United States)

    Parise, Eric M.; Alcantara, Lyonna F.; Warren, Brandon L.; Wright, Katherine N.; Hadad, Roey; Sial, Omar K.; Kroeck, Kyle G.; Iñiguez, Sergio D.; Bolaños-Guzmán, Carlos A.

    2013-01-01

    Background Major Depressive Disorder (MDD) afflicts up to 10% of adolescents. However, nearly 50% of those afflicted are considered non-responsive to available treatments. Ketamine, a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist has shown potential as a rapid-acting and long-lasting treatment for MDD in adults. Thus, the effectiveness and functional consequences of ketamine exposure during adolescence were explored. Methods Adolescent male rats (postnatal day [PD] 35) received two ketamine (0, 5, 10 or 20 mg/kg) injections, 4 hours apart, after exposure to day 1 of the forced swim test (FST). The next day, rats were re-exposed to the FST to assess ketamine-induced antidepressant-like responses. Separate groups were exposed to chronic unpredictable stress (CUS) to confirm findings from the FST. After these initial experiments, adolescent naïve rats were exposed to either 1 or 15 consecutive days (PD35–49) of ketamine (20 mg/kg) twice/daily. Ketamine's influence on behavioral reactivity to rewarding (i.e., sucrose preference) and aversive (i.e., elevated plus-maze, FST) circumstances was then assessed 2 months after treatment. To control for age-dependent effects, adult rats (PD75–89) were exposed to identical experimental conditions. Results Ketamine (20 mg/kg) reversed the CUS-induced depression-like behaviors in the FST. Repeated ketamine exposure resulted in anxiolytic- and antidepressant-like responses 2 months after drug exposure. None of the ketamine doses used were capable of inducing drug-seeking behaviors as measured by place preference conditioning. Conclusions Repeated ketamine exposure induces enduring resilient-like responses regardless of age of exposure. These findings point to ketamine, and its repeated exposure, as a potentially useful antidepressant during adolescence. PMID:23790225

  19. Exaggerated phosphorylation of brain tau protein in CRH KO mice exposed to repeated immobilization stress.

    Science.gov (United States)

    Kvetnansky, Richard; Novak, Petr; Vargovic, Peter; Lejavova, Katarina; Horvathova, Lubica; Ondicova, Katarina; Manz, George; Filipcik, Peter; Novak, Michal; Mravec, Boris

    2016-07-01

    Neuroendocrine and behavioral stress responses are orchestrated by corticotropin-releasing hormone (CRH) and norepinephrine (NE) synthesizing neurons. Recent findings indicate that stress may promote development of neurofibrillary pathology in Alzheimer's disease. Therefore, we investigated relationships among stress, tau protein phosphorylation, and brain NE using wild-type (WT) and CRH-knockout (CRH KO) mice. We assessed expression of phosphorylated tau (p-tau) at the PHF-1 epitope and NE concentrations in the locus coeruleus (LC), A1/C1 and A2/C2 catecholaminergic cell groups, hippocampus, amygdala, nucleus basalis magnocellularis, and frontal cortex of unstressed, singly stressed or repeatedly stressed mice. Moreover, gene expression and protein levels of tyrosine hydroxylase (TH) and CRH receptor mRNA were determined in the LC. Plasma corticosterone levels were also measured. Exposure to a single stress increases tau phosphorylation throughout the brain in WT mice when compared to singly stressed CRH KO animals. In contrast, repeatedly stressed CRH KO mice showed exaggerated tau phosphorylation relative to WT controls. We also observed differences in extent of tau phosphorylation between investigated structures, e.g. the LC and hippocampus. Moreover, CRH deficiency leads to different responses to stress in gene expression of TH, NE concentrations, CRH receptor mRNA, and plasma corticosterone levels. Our data indicate that CRH effects on tau phosphorylation are dependent on whether stress is single or repeated, and differs between brain regions. Our findings indicate that CRH attenuates mechanisms responsible for development of stress-induced tau neuropathology, particularly in conditions of chronic stress. However, the involvement of central catecholaminergic neurons in these mechanisms remains unclear and is in need of further investigation.

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

    Science.gov (United States)

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

    2014-04-01

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

  1. Habituation to repeated stress: get used to it.

    OpenAIRE

    Grissom, Nicola; Bhatnagar, Seema

    2008-01-01

    Habituation, as described in the landmark paper by Thompson and Spencer (1966), is a form of simple, nonassociative learning in which the magnitude of the response to a specific stimulus decreases with repeated exposure to that stimulus. A variety of neuronal and behavioral responses have been shown to be subject to habituation based on the criteria presented in that paper. It has been known for several decades that the magnitude of hypothalamic-pituitary-adrenal (HPA) activation occurring in...

  2. Repeated predictable stress causes resilience against colitis-induced behavioral changes in mice

    Science.gov (United States)

    Hassan, Ahmed M.; Jain, Piyush; Reichmann, Florian; Mayerhofer, Raphaela; Farzi, Aitak; Schuligoi, Rufina; Holzer, Peter

    2014-01-01

    Inflammatory bowel disease is associated with an increased risk of mental disorders and can be exacerbated by stress. In this study which was performed with male 10-week old C57Bl/6N mice, we used dextran sulfate sodium (DSS)-induced colitis to evaluate behavioral changes caused by intestinal inflammation, to assess the interaction between repeated psychological stress (water avoidance stress, WAS) and colitis in modifying behavior, and to analyze neurochemical correlates of this interaction. A 7-day treatment with DSS (2% in drinking water) decreased locomotion and enhanced anxiety-like behavior in the open field test and reduced social interaction. Repeated exposure to WAS for 7 days had little influence on behavior but prevented the DSS-induced behavioral disturbances in the open field and SI tests. In contrast, repeated WAS did not modify colon length, colonic myeloperoxidase content and circulating proinflammatory cytokines, parameters used to assess colitis severity. DSS-induced colitis was associated with an increase in circulating neuropeptide Y (NPY), a rise in the hypothalamic expression of cyclooxygenase-2 mRNA and a decrease in the hippocampal expression of NPY mRNA, brain-derived neurotrophic factor mRNA and mineralocorticoid receptor mRNA. Repeated WAS significantly decreased the relative expression of corticotropin-releasing factor mRNA in the hippocampus. The effect of repeated WAS to blunt the DSS-evoked behavioral disturbances was associated with a rise of circulating corticosterone and an increase in the expression of hypothalamic NPY mRNA. These results show that experimental colitis leads to a particular range of behavioral alterations which can be prevented by repeated WAS, a model of predictable chronic stress, while the severity of colitis remains unabated. We conclude that the mechanisms underlying the resilience effect of repeated WAS involves hypothalamic NPY and the hypothalamic-pituitary-adrenal axis. PMID:25414650

  3. Repeated Predictable Stress Causes Resilience against Colitis-Induced Behavioral Changes in Mice

    Directory of Open Access Journals (Sweden)

    Ahmed M Hassan

    2014-11-01

    Full Text Available Inflammatory bowel disease is associated with an increased risk of mental disorders and can be exacerbated by stress. In this study which was performed with male 10-week old C57Bl/6N mice, we used dextran sulfate sodium (DSS-induced colitis to evaluate behavioral changes caused by intestinal inflammation, to assess the interaction between repeated psychological stress (water avoidance stress, WAS and colitis in modifying behavior, and to analyze neurochemical correlates of this interaction. A 7-day treatment with DSS (2 % in drinking water decreased locomotion and enhanced anxiety-like behavior in the open field test and reduced social interaction. Repeated exposure to WAS for 7 days had little influence on behavior but prevented the DSS-induced behavioral disturbances in the open field and social interaction tests. In contrast, repeated WAS did not modify colon length, colonic myeloperoxidase content and circulating proinflammatory cytokines, parameters used to assess colitis severity. DSS-induced colitis was associated with an increase in circulating neuropeptide Y (NPY, a rise in the hypothalamic expression of cyclooxygenase-2 mRNA and a decrease in the hippocampal expression of NPY mRNA, brain-derived neurotrophic factor mRNA and mineralocorticoid receptor mRNA. Repeated WAS significantly decreased the relative expression of corticotropin-releasing factor mRNA in the hippocampus. The effect of repeated WAS to blunt the DSS-evoked behavioral disturbances was associated with a rise of circulating corticosterone and an increase in the expression of hypothalamic NPY mRNA. These results show that experimental colitis leads to a particular range of behavioral alterations which can be prevented by repeated WAS, a model of predictable chronic stress, while the severity of colitis remains unabated. We conclude that the mechanisms underlying the resilience effect of repeated WAS involves hypothalamic NPY and the hypothalamic-pituitary-adrenal axis.

  4. Endocannabinoid signalling modulates susceptibility to traumatic stress exposure

    Science.gov (United States)

    Bluett, Rebecca J.; Báldi, Rita; Haymer, Andre; Gaulden, Andrew D.; Hartley, Nolan D.; Parrish, Walker P.; Baechle, Jordan; Marcus, David J.; Mardam-Bey, Ramzi; Shonesy, Brian C.; Uddin, Md. Jashim; Marnett, Lawrence J.; Mackie, Ken; Colbran, Roger J.; Winder, Danny G.; Patel, Sachin

    2017-01-01

    Stress is a ubiquitous risk factor for the exacerbation and development of affective disorders including major depression and posttraumatic stress disorder. Understanding the neurobiological mechanisms conferring resilience to the adverse consequences of stress could have broad implications for the treatment and prevention of mood and anxiety disorders. We utilize laboratory mice and their innate inter-individual differences in stress-susceptibility to demonstrate a critical role for the endogenous cannabinoid 2-arachidonoylglycerol (2-AG) in stress-resilience. Specifically, systemic 2-AG augmentation is associated with a stress-resilient phenotype and enhances resilience in previously susceptible mice, while systemic 2-AG depletion or CB1 receptor blockade increases susceptibility in previously resilient mice. Moreover, stress-resilience is associated with increased phasic 2-AG-mediated synaptic suppression at ventral hippocampal-amygdala glutamatergic synapses and amygdala-specific 2-AG depletion impairs successful adaptation to repeated stress. These data indicate amygdala 2-AG signalling mechanisms promote resilience to adverse effects of acute traumatic stress and facilitate adaptation to repeated stress exposure. PMID:28348378

  5. Exogenous daytime melatonin modulates response of adolescent mice in a repeated unpredictable stress paradigm.

    Science.gov (United States)

    Onaolapo, Adejoke Yetunde; Adebayo, Ajibola Nurudeen; Onaolapo, Olakunle James

    2017-02-01

    The immediate and short-term behavioural and physiological implications of exposure to stressful scenarios in the adolescent period are largely unknown; however, increases in occurrence of stress-related physiological and psychological disorders during puberty highlight the need to study substances that may modulate stress reactivity during a crucial stage of maturation. Seven groups of mice (12-15 g each) were administered distilled water (DW) (non-stressed and stressed controls), sertraline (10 mg/kg), diazepam (2 mg/kg) or one of three doses of melatonin (5, 10 and 15 mg/kg). Mice were exposed to 30 min of chronic mild stress (25 min of cage shaking, cage tilting, handling and 5 min of forced swimming in tepid warm water at 25 °C, in a random order) after administration of DW or drugs, daily for 21 days. Behavioural assessments were conducted on day 1 and day 21 (after which mice were sacrificed, blood taken for estimation of corticosterone levels and brain homogenates used for estimation of antioxidant activities). Administration of melatonin resulted in an increase in horizontal locomotion and self-grooming, while rearing showed a time-dependent increase, compared to non-stress and stress controls. Working memory improved with increasing doses of melatonin (compared to controls and diazepam); in comparison to setraline however, working memory decreased. A dose-related anxiolytic effect is seen when melatonin is compared to non-stressed and stressed controls. Melatonin administration reduced the systemic/oxidant response to repeated stress. Administration of melatonin in repeatedly stressed adolescent mice was associated with improved central excitation, enhancement of working memory, anxiolysis and reduced systemic response to stress.

  6. Repeated forced swim stress differentially affects formalin-evoked nociceptive behaviour and the endocannabinoid system in stress normo-responsive and stress hyper-responsive rat strains.

    Science.gov (United States)

    Jennings, Elaine M; Okine, Bright N; Olango, Weredeselam M; Roche, Michelle; Finn, David P

    2016-01-01

    Repeated exposure to a homotypic stressor such as forced swimming enhances nociceptive responding in rats. However, the influence of genetic background on this stress-induced hyperalgesia is poorly understood. The aim of the present study was to compare the effects of repeated forced swim stress on nociceptive responding in Sprague-Dawley (SD) rats versus the Wistar Kyoto (WKY) rat strain, a genetic background that is susceptible to stress, negative affect and hyperalgesia. Given the well-documented role of the endocannabinoid system in stress and pain, we investigated associated alterations in endocannabinoid signalling in the dorsal horn of the spinal cord and amygdala. In SD rats, repeated forced swim stress for 10 days was associated with enhanced late phase formalin-evoked nociceptive behaviour, compared with naive, non-stressed SD controls. In contrast, WKY rats exposed to 10 days of swim stress displayed reduced late phase formalin-evoked nociceptive behaviour. Swim stress increased levels of monoacylglycerol lipase (MAGL) mRNA in the ipsilateral side of the dorsal spinal cord of SD rats, an effect not observed in WKY rats. In the amygdala, swim stress reduced anandamide (AEA) levels in the contralateral amygdala of SD rats, but not WKY rats. Additional within-strain differences in levels of CB1 receptor and fatty acid amide hydrolase (FAAH) mRNA and levels of 2-arachidonylglycerol (2-AG) were observed between the ipsilateral and contralateral sides of the dorsal horn and/or amygdala. These data indicate that the effects of repeated stress on inflammatory pain-related behaviour are different in two rat strains that differ with respect to stress responsivity and affective state and implicate the endocannabinoid system in the spinal cord and amygdala in these differences.

  7. Facilitation of hypothalamic-pituitary-adrenal responses to novel stress following repeated social stress using the resident/intruder paradigm.

    Science.gov (United States)

    Bhatnagar, Seema; Vining, Courtenay

    2003-01-01

    Our goal in these studies was to characterize some specific aspects of hypothalamic-pituitary-adrenal (HPA) activity in rats exposed to repeated social stress. We used a modification of the resident/intruder paradigm in which male intruder rats were subjected to defeat and then separated from the resident by an enclosure for a total of 30 min on Day 1. On Days 2-7, intruder rats were exposed to different resident rats every day through a wire mesh enclosure for 30 min in order to minimize injurious physical contact between the two rats. The intruder rats gained significantly less weight than controls over the 7-day period of stress though basal corticosterone levels and adrenal and thymus weights were not significantly different between the two groups. On Day 8, repeatedly stressed rats exhibited facilitation of HPA responses to novel restraint compared to controls but no differences in negative feedback sensitivity to dexamethasone (0.05 or 0.2 mg/kg) were observed. Thus, the HPA axis of socially stressed rats remains responsive to a stimulus that has never been encountered. Using this type of repeated presentation to an aggressive resident allows us to examine the neuroendocrine and behavioral consequences, and their underlying neural mechanisms, of exposure to a stressor that is social in nature and naturalistic for rodents.

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

    Science.gov (United States)

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

    1987-06-01

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

  9. REPEATED ACUTE STRESS INDUCED ALTERATIONS IN CARBOHYDRATE METABOLISM IN RAT

    Directory of Open Access Journals (Sweden)

    Nirupama R.

    2010-09-01

    Full Text Available Acute stress induced alterations in the activity levels of rate limiting enzymes and concentration of intermediates of different pathways of carbohydrate metabolism have been studied. Adult male Wistar rats were restrained (RS for 1 h and after an interval of 4 h they were subjected to forced swimming (FS exercise and appropriate controls were maintained. Five rats were killed before the commencement of the experiment (initial controls, 5 control and equal number of stressed rats were killed 2 h after RS and remaining 5 rats in each group were killed 4 h after FS. There was a significant increase in the adrenal 3β- hydroxy steroid dehydrogenase activity following RS, which showed further increase after FS compared to controls and thereby indicated stress response of rats. There was a significant increase in the blood glucose levels following RS which showed further increase and reached hyperglycemic condition after FS. The hyperglycemic condition due to stress was accompanied by significant increases in the activities of glutamate- pyruvate transaminase, glutamate- oxaloacetate transaminase, glucose -6- phosphatase and lactate dehydrogenase and significant decrease in the glucose -6- phosphate dehydrogenase and pyruvate dehydrogenase activities, whereas pyruvate kinase activity did not show any alteration compared to controls. Further, the glycogen and total protein contents of the liver were decreased whereas those of pyruvate and lactate showed significant increase compared to controls after RS as well as FS.The results put together indicate that acute stress induced hyperglycemia results due to increased gluconeogenesis and glycogenolysis without alteration in glycolysis. The study first time reveals that after first acute stress exposure, the subsequent stressful experience augments metabolic stress response leading to hyperglycemia. The results have relevance to human health as human beings are exposed to several stressors in a day and

  10. 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 cigarett

  11. 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 cigarett

  12. 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

  13. 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

  14. 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

  15. Systemic and Local Responses to Repeated HL Stress-Induced Retrograde Signaling in Arabidopsis.

    Science.gov (United States)

    Gordon, Matthew J; Carmody, Melanie; Albrecht, Verónica; Pogson, Barry

    2012-01-01

    CHLOROPLASTS OF LEAVES UNDER HIGH LIGHT STRESS INITIATE SIGNALS TO THE NUCLEI OF BOTH EXPOSED AND DISTAL LEAVES IN ORDER TO ACCLIMATE AGAINST THE POTENTIAL THREAT OF OXIDATIVE DAMAGE: a process known as high light systemic acquired acclimation (HL SAA). This study explores the nature of HL SAA, synergistic interactions with other environmental stresses, and the impact of repeated HL stress on the acclimation response of exposed and distal leaves. This necessitated the development of novel experimental systems to investigate the initiation, perception, and response to HL SAA. These systems were used to investigate the HL SAA response by monitoring the induction of mRNA in distal leaves not exposed to the HL stress. Acclimation to HL is induced within minutes and the response is proportionally dependent on the quality and quantity of light. HL SAA treatments in conjunction with variations in temperature and humidity reveal HL SAA is influenced by fluctuations in humidity. These treatments also result in changes in auxin accumulation and auxin-responsive genes. A key question in retrograde signaling is the extent to which transient changes in light intensity result in a "memory" of the event leading to acclimation responses. Repeated exposure to short term HL resulted in acclimation of the exposed tissue and that of emerging and young leaves (but not older leaves) to HL and oxidative stress.

  16. Effect of acute and repeated restraint stress on glucose oxidation to CO2 in hippocampal and cerebral cortex slices

    Directory of Open Access Journals (Sweden)

    Torres I.L.S.

    2001-01-01

    Full Text Available It has been suggested that glucocorticoids released during stress might impair neuronal function by decreasing glucose uptake by hippocampal neurons. Previous work has demonstrated that glucose uptake is reduced in hippocampal and cerebral cortex slices 24 h after exposure to acute stress, while no effect was observed after repeated stress. Here, we report the effect of acute and repeated restraint stress on glucose oxidation to CO2 in hippocampal and cerebral cortex slices and on plasma glucose and corticosterone levels. Male adult Wistar rats were exposed to restraint 1 h/day for 50 days in the chronic model. In the acute model there was a single exposure. Immediately or 24 h after stress, the animals were sacrificed and the hippocampus and cerebral cortex were dissected, sliced, and incubated with Krebs buffer, pH 7.4, containing 5 mM glucose and 0.2 µCi D-[U-14C] glucose. CO2 production from glucose was estimated. Trunk blood was also collected, and both corticosterone and glucose were measured. The results showed that corticosterone levels after exposure to acute restraint were increased, but the increase was smaller when the animals were submitted to repeated stress. Blood glucose levels increased after both acute and repeated stress. However, glucose utilization, measured as CO2 production in hippocampal and cerebral cortex slices, was the same in stressed and control groups under conditions of both acute and chronic stress. We conclude that, although stress may induce a decrease in glucose uptake, this effect is not sufficient to affect the energy metabolism of these cells.

  17. How integrated are behavioral and endocrine stress response traits? A repeated measures approach to testing the stress-coping style model.

    Science.gov (United States)

    Boulton, Kay; Couto, Elsa; Grimmer, Andrew J; Earley, Ryan L; Canario, Adelino V M; Wilson, Alastair J; Walling, Craig A

    2015-02-01

    It is widely expected that physiological and behavioral stress responses will be integrated within divergent stress-coping styles (SCS) and that these may represent opposite ends of a continuously varying reactive-proactive axis. If such a model is valid, then stress response traits should be repeatable and physiological and behavioral responses should also change in an integrated manner along a major axis of among-individual variation. While there is some evidence of association between endocrine and behavioral stress response traits, few studies incorporate repeated observations of both. To test this model, we use a multivariate, repeated measures approach in a captive-bred population of Xiphophorus birchmanni. We quantify among-individual variation in behavioral stress response to an open field trial (OFT) with simulated predator attack (SPA) and measure waterborne steroid hormone levels (cortisol, 11-ketotestosterone) before and after exposure. Under the mild stress stimulus (OFT), (multivariate) behavioral variation among individuals was consistent with a strong axis of personality (shy-bold) or coping style (reactive-proactive) variation. However, behavioral responses to a moderate stressor (SPA) were less repeatable, and robust statistical support for repeatable endocrine state over the full sampling period was limited to 11-ketotestosterone. Although post hoc analysis suggested cortisol expression was repeatable over short time periods, qualitative relationships between behavior and glucocorticoid levels were counter to our a priori expectations. Thus, while our results clearly show among-individual differences in behavioral and endocrine traits associated with stress response, the correlation structure between these is not consistent with a simple proactive-reactive axis of integrated stress-coping style. Additionally, the low repeatability of cortisol suggests caution is warranted if single observations (or indeed repeat measures over short sampling

  18. 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.

  19. Lens opacities after repeated exposure to ultraviolet radiation.

    Science.gov (United States)

    Michael, R; Löfgren, S; Söderberg, P G

    1999-12-01

    To investigate the effect of the interval between two, near-threshold exposures to ultraviolet radiation (UVR) on cataract development. One eye of Sprague-Dawley rats was exposed twice to 4 kJ/m2 narrow band UVR (lambdaMAX=300 nm) for 15 min each. The interval between exposures was 0, 6, 24 or 48 h. One week after the first exposure both lenses were removed for photography and measurement of the intensity of forward light scattering to quantify lens opacities. All exposed lenses developed cataract. Forward light scattering was the same after double exposure with no interval or a 6 h interval. Forward light scattering after a 24 or 48 h interval was nearly twofold greater than that following no interval or a 6 h interval. The exposed lenses in all groups had mild anterior surface opacities and intense equatorial opacities as judged with a stereomicroscope. Two, near-threshold UVR exposures at 0 or a 6 h interval produce the same degree of lens opacification. When the second exposure follows 24 or 48 h after the first, lenticular damage increases. Repair processes between 24 and 48 h after exposure appear to be sensitive to UVR, and an additional exposure during this time may aggravate cataract development.

  20. GSTM1 and APE1 genotypes affect arsenic-induced oxidative stress: a repeated measures study

    National Research Council Canada - National Science Library

    Breton, Carrie V; Kile, Molly L; Catalano, Paul J; Hoffman, Elaine; Quamruzzaman, Quazi; Rahman, Mahmuder; Mahiuddin, Golam; Christiani, David C

    2007-01-01

    .... Generation of oxidative stress may contribute to arsenic carcinogenesis. To investigate the association between arsenic exposure and oxidative stress, urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG...

  1. Positive affective interactions: The role of repeated exposure and copresence

    NARCIS (Netherlands)

    Shahid, S.; Krahmer, E.; Neerincx, M.; Swerts, M.

    2013-01-01

    We describe and evaluate a new interface to induce positive emotions in users: a digital, interactive adaptive mirror. We study whether the induced affect is repeatable after a fixed interval (Study 1) and how copresence influences the emotion induction (Study 2). Results show that participants syst

  2. Effects of hyperlipidemia on adaptive responses to repeated zinc exposure

    Science.gov (United States)

    In individuals with underlying atherosclerosis and coronary heart disease (CHD), exposure to near-road air pollution correlates epidemiologically with deleterious health outcome. Associated cardiotoxicity purportedly involves generation of reactive oxygen species (ROS) and activa...

  3. 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...... with a group of patients who immersed a finger into water. The nickel concentrations used also provoked significant inflammatory skin changes on sodium lauryl sulphate (SLS)-treated forearm skin of the patients, whereas inflammatory skin changes were not observed in healthy volunteers without hand eczema...

  4. Sensitization and Tolerance Following Repeated Exposure to Caffeine and Alcohol in Mice

    Science.gov (United States)

    May, Christina E.; Haun, Harold L.; Griffin, William C.

    2015-01-01

    Introduction Energy drinks are popular mixers with alcohol. While energy drinks contain many ingredients, caffeine is an important pharmacologically active component and is generally present in larger amounts than in other caffeinated beverages. In these studies, we investigated the hypothesis that caffeine would influence the effects of alcohol (ethanol) on conditioned taste aversion, ataxia and locomotor activity after repeated exposure. Methods Four groups of mice were exposed by oral gavage twice daily to vehicle, ethanol (4 g/kg), caffeine (15 mg/kg), or the ethanol/caffeine combination. Conditioned taste aversion to saccharin and ataxia in the parallel rod task were evaluated after 8 or 16 gavages, respectively, using ethanol (1–3 g/kg) or ethanol/caffeine (3mg/kg + 2 g/kg) challenges. In addition, locomotor activity was evaluated initially and after repeated exposure to oral gavage of these drugs and doses. Results Repeated oral gavage of ethanol produced significant locomotor sensitization, with those mice increasing total distance traveled by 2-fold. The locomotor response to caffeine, while significantly greater than vehicle gavage, did not change with repeated exposure. On the other hand, repeated gavage of caffeine/ethanol combination produced a substantial increase in total distance traveled after repeated exposure (~4-fold increase). After repeated ethanol exposure, there was significant tolerance to ethanol in the conditioned taste aversion and parallel rod tests. However, neither a history of caffeine exposure nor including caffeine influenced ethanol-induced conditioned taste aversion. Interestingly, a history of caffeine exposure increased the ataxic response to the caffeine/ethanol combination and appeared to reduce the ataxic response to high doses of ethanol. Conclusion The data support the general hypothesis that repeated exposure to caffeine influences the response to ethanol. Together with previously published work, these data indicate

  5. A Preliminary Evaluation of Repeated Exposure for Depersonalization and Derealization

    Science.gov (United States)

    Weiner, Elliot; McKay, Dean

    2013-01-01

    Dissociative symptoms including depersonalization and derealization are commonly experienced by individuals suffering from panic disorder or posttraumatic stress disorder (PTSD). Few studies have been published investigating the specific treatment of these symptoms in individuals diagnosed with panic disorder or PTSD, despite evidence that the…

  6. 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 (Fe2 O3 -NPs) could be toxic to mice testis. Fe2 O3 -NPs (25 and 50 mg/kg) were intraperitoneally administered into mice once a week for 4 weeks. Our study showed that Fe2 O3 -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 Fe2 O3 -NPs which was evidenced from the iron content and accumulation in the testis. Furthermore, 25 and 50 mg/kg Fe2 O3 -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 Fe2 O3 -NPs exposure. In addition, the histopathological lesions like vacuolization, detachment, and sloughing of germ cells were also observed in response to Fe2 O3 -NPs treatment. The data from our study entailed that testicular toxicity caused by Fe2 O3 -NPs exposure may be associated with Fe2 O3 -NPs accumulation leading to oxidative stress and apoptosis. Therefore, precautions should be taken in the safe use of Fe2 O3 -NPs to avoid complications in the fertility of males. Further research will unravel the possible molecular mechanisms on testicular toxicity of Fe2 O3 -NPs. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 594-608, 2017.

  7. Respiratory toxicity of repeated exposure to particles produced by traffic and sugar cane burning.

    Science.gov (United States)

    Mazzoli-Rocha, Flavia; Carvalho, Giovanna M C; Lanzetti, Manuella; Valença, Samuel S; Silva, Luiz F F; Saldiva, Paulo H N; Zin, Walter A; Faffe, Débora S

    2014-01-15

    We compared the toxicity of subchronic exposure to equivalent masses of particles from sugar cane burning and traffic. BALB/c mice received 3 intranasal instillations/week during 1, 2 or 4 weeks of either distilled water (C1, C2, C4) or particles (15μg) from traffic (UP1, UP2, UP4) or biomass burning (BP1, BP2, BP4). Lung mechanics, histology and oxidative stress were analyzed 24h after the last instillation. In all instances UP and BP groups presented worse pulmonary elastance, airway and tissue resistance, alveolar collapse, bronchoconstriction and macrophage influx into the lungs than controls. UP4, BP2 and BP4 presented more alveolar collapse than UP1 and BP1, respectively. UP and BP had worse bronchial and alveolar lesion scores than their controls; BP4 had greater bronchial lesion scores than UP4. Catalase was higher in UP4 and BP4 than in C4. In conclusion, biomass particles were more toxic than those from traffic after repeated exposures.

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

    Science.gov (United States)

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

    2015-01-01

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

  9. 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.

  10. 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.

  11. 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. Co

  12. Mid-Childhood Bone Mass After Exposure to Repeat Doses of Antenatal Glucocorticoids: A Randomized Trial.

    Science.gov (United States)

    McKinlay, Christopher J D; Cutfield, Wayne S; Battin, Malcolm R; Dalziel, Stuart R; Crowther, Caroline A; Harding, Jane E

    2017-05-01

    Treatment of women at risk for preterm birth with repeat doses of glucocorticoids reduces neonatal morbidity, but could have adverse effects on skeletal development. We assessed whether exposure to repeat antenatal betamethasone alters bone mass in children whose mothers participated in the Australasian Collaborative Trial of Repeat Doses of Corticosteroids. Women were randomized to a single dose of betamethasone or placebo, ≥7 days after an initial course of glucocorticoids, repeated each week that they remained at risk for preterm birth at children underwent whole-body dual-energy radiograph absorptiometry at 6 to 8 years' corrected age. Of 212 eligible childhood survivors, 185 were studied (87%; 91 repeat betamethasone group; 94 placebo [single course] group). Children exposed to repeat antenatal betamethasone and those exposed to placebo had similar whole-body bone mineral content (median repeat betamethasone: 553 g, interquartile range: 442-712 g; placebo: 567 g, interquartile range: 447-750 g; geometric mean ratio: 0.99; 95% confidence interval: 0.94-1.03, P = .55) and bone area (median repeat betamethasone 832 cm(2), interquartile range: 693-963 cm(2); placebo: 822 cm(2), interquartile range: 710-1020 cm(2); geometric mean ratio: 0.99, 95% confidence interval: 0.92-1.07, P = .75). Exposure to repeat doses of antenatal betamethasone compared with a single course of glucocorticoids does not alter bone mass in mid-childhood. Copyright © 2017 by the American Academy of Pediatrics.

  13. 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.

  14. Repeated exposure to noise increases tolerance in a coral reef fish.

    Science.gov (United States)

    Nedelec, Sophie L; Mills, Suzanne C; Lecchini, David; Nedelec, Brendan; Simpson, Stephen D; Radford, Andrew N

    2016-09-01

    Some anthropogenic noise is now considered pollution, with evidence building that noise from human activities such as transportation, construction and exploration can impact behaviour and physiology in a broad range of taxa. However, relatively little research has considered the effects of repeated or chronic noise; extended exposures may result in habituation or sensitisation, and thus changes in response. We conducted a field-based experiment at Moorea Island to investigate how repeated exposure to playback of motorboat noise affected a coral reef fish (Dascyllus trimaculatus). We found that juvenile D. trimaculatus increased hiding behaviour during motorboat noise after two days of repeated exposure, but no longer did so after one and two weeks of exposure. We also found that naïve individuals responded to playback of motorboat noise with elevated ventilation rates, but that this response was diminished after one and two weeks of repeated exposure. We found no strong evidence that baseline blood cortisol levels, growth or body condition were affected by three weeks of repeated motorboat-noise playback. Our study reveals the importance of considering how tolerance levels may change over time, rather than simply extrapolating from results of short-term studies, if we are to make decisions about regulation and mitigation.

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

    Science.gov (United States)

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

    2013-11-27

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

  16. Estrogen protects against the detrimental effects of repeated stress on glutamatergic transmission and cognition.

    Science.gov (United States)

    Wei, J; Yuen, E Y; Liu, W; Li, X; Zhong, P; Karatsoreos, I N; McEwen, B S; Yan, Z

    2014-05-01

    Converging evidence suggests that females and males show different responses to stress; however, little is known about the mechanism underlying the sexually dimorphic effects of stress. In this study, we found that young female rats exposed to 1 week of repeated restraint stress show no negative effects on temporal order recognition memory (TORM), a cognitive process controlled by the prefrontal cortex (PFC), which was contrary to the impairment in TORM observed in stressed males. Concomitantly, normal glutamatergic transmission and glutamate receptor surface expression in PFC pyramidal neurons were found in repeatedly stressed females, in contrast to the significant reduction seen in stressed males. The detrimental effects of repeated stress on TORM and glutamate receptors were unmasked in stressed females when estrogen receptors were inhibited or knocked down in PFC, and were prevented in stressed males with the administration of estradiol. Blocking aromatase, the enzyme for the biosynthesis of estrogen, revealed the stress-induced glutamatergic deficits and memory impairment in females, and the level of aromatase was significantly higher in the PFC of females than in males. These results suggest that estrogen protects against the detrimental effects of repeated stress on glutamatergic transmission and PFC-dependent cognition, which may underlie the stress resilience of females.

  17. GSTM1 and APE1 genotypes affect arsenic-induced oxidative stress: a repeated measures study

    Directory of Open Access Journals (Sweden)

    Quamruzzaman Quazi

    2007-12-01

    Full Text Available Abstract Background Chronic arsenic exposure is associated with an increased risk of skin, bladder and lung cancers. Generation of oxidative stress may contribute to arsenic carcinogenesis. Methods To investigate the association between arsenic exposure and oxidative stress, urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG was evaluated in a cohort of 97 women recruited from an arsenic-endemic region of Bangladesh in 2003. Arsenic exposure was measured in urine, toenails, and drinking water. Drinking water and urine samples were collected on three consecutive days. Susceptibility to oxidative stress was evaluated by genotyping relevant polymorphisms in glutathione-s transferase mu (GSTM1, human 8-oxoguanine glycosylase (hOGG1 and apurinic/apyrimidinic endonuclease (APE1 genes using the Taqman method. Data were analyzed using random effects Tobit regression to account for repeated measures and 8-OHdG values below the detection limit. Results A consistent negative effect for APE1 was observed across water, toenail and urinary arsenic models. APE1 148 glu/glu + asp/glu genotype was associated with a decrease in logged 8-OHdG of 0.40 (95%CI -0.73, -0.07 compared to APE1 148 asp/asp. An association between total urinary arsenic and 8-OHdG was observed among women with the GSTM1 null genotype but not in women with GSTM1 positive. Among women with GSTM1 null, a comparison of the second, third, and fourth quartiles of total urinary arsenic to the first quartile resulted in a 0.84 increase (95% CI 0.27, 1.42, a 0.98 increase (95% CI 033, 1.66 and a 0.85 increase (95% CI 0.27, 1.44 in logged 8-OHdG, respectively. No effects between 8-OHdG and toenail arsenic or drinking water arsenic were observed. Conclusion These results suggest the APE1 variant genotype decreases repair of 8-OHdG and that arsenic exposure is associated with oxidative stress in women who lack a functional GSTM1 detoxification enzyme.

  18. Repeated Exposure to Sublethal Doses of the Organophosphorus Compound VX Activates BDNF Expression in Mouse Brain

    Science.gov (United States)

    2012-01-01

    cresyl/-4 H-1: 3: 2-benzodioxa- phosphorin-2-oxide (CBDP) on organophosphate poisoning and its therapy. Arch. Toxicol. 42, 207–216. French, S. J... organophosphates or other environmental insults, have a greater FIG. 4. Mice that received repeated exposure to low levels of VX (0.2 LD50 and 0.4 LD50...to neuro- behavioral deficits and neuropathology. Although exposure to organophosphates such as pesticides has been shown to affect the expression of

  19. The levels of kerosene components in biological samples after repeated dermal exposure to kerosene in rats.

    Science.gov (United States)

    Fujihara, Junko; Hieda, Yoko; Tsujino, Yoshio; Xue, Yuying; Takayama, Koji; Kimura, Kojiro; Dekio, Satoshi

    2004-04-01

    The current study was experimentally investigated using rats whether or not kerosene components are accumulated from daily repeated dermal exposure. Rats received daily 1h-exposure to kerosene for 5 days (5K), daily 1h-exposure for 4 days and left for 1 day (4KL), a single 1h-exposure (1K), a single 1h-exposure and left for 1 day (1KL), or a single 1h-exposure, sacrificed and left dead for 1 day (1KLD). Kerosene components, trimethylbenzenes (TMBs) and aliphatic hydrocarbons (AHCs) in blood and tissues were determined by GC-MS. In blood, almost the same concentrations of TMBs were detected in the rats sacrificed immediately after exposure (5K, 1K and 1KLD), and only trace levels were detected in the rats sacrificed 1 day after exposure (4 and 1KL). Almost the same levels of AHCs in blood were detected among groups except for the rats sacrificed 1 day after a single exposure (1KL), in which AHCs were slightly lower. These results suggest that (1) AHCs tend to be accumulated from daily exposure, while TMBs do not, (2) the proportions of detected kerosene components in blood can be an indicator of whether the last exposure occurred just before death or not, (3) the kerosene levels last at least 1 day without blood circulation.

  20. 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 (

  1. Repeated toluene exposure increases c-Fos in catecholaminergic cells of the nucleus accumbens shell.

    Science.gov (United States)

    Tomaszycki, Michelle L; Aulerich, Kelsey E; Bowen, Scott E

    2013-01-01

    Toluene is a frequently abused solvent. Previous studies have suggested that toluene acts like other drugs of abuse, specifically on the dopaminergic system in the nucleus accumbens (NAc) and ventral tegmental area (VTA) of the mesolimbic pathway. Although changes in dopamine (DA) levels and c-Fos have been observed in both acute and repeated exposure paradigms, the extent to which c-Fos is localized to catecholaminergic cells is unknown. The present study tested the effects of repeated toluene exposure (1000-4000ppm) on locomotor activity and cells containing c-Fos, tyrosine hydroxylase (TH), or both in the core and shell of the NAc, as well as the anterior and posterior VTA. We focused our study on adolescents, since adolescence is a time of great neural change and a time when individuals tend to be more susceptible to drug abuse. In early tests, toluene dose-dependently increased locomotor activity. Repeated exposure to the highest concentration of toluene resulted in sensitization to toluene's effects on locomotor activity. Although the number of cells immunopositive for c-Fos or TH did not significantly differ across groups, cells immunopositive for TH+c-Fos were higher in the NAc shell of animals exposed to 4000ppm than in animals exposed to air (control) or 1000ppm. Taken together, these findings demonstrate that repeated high dose toluene exposure increases locomotor activity as well as activation of catecholaminergic cells in the shell of the NAc. © 2013 Elsevier Inc. All rights reserved.

  2. Effect of Repeated Exposures on Word Learning in Quiet and Noise

    Science.gov (United States)

    Blaiser, Kristina M.; Nelson, Peggy B.; Kohnert, Kathryn

    2015-01-01

    This study examines the impact of repeated exposures on word learning of preschool children with and without hearing loss (HL) in quiet and noise conditions. Participants were 19 children with HL and 17 peers with normal hearing (NH). Children were introduced to 16 words: 8 in quiet and 8 in noise conditions. Production and identification scores…

  3. 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

  4. Effect of repeated exposures and sociality on novel food acceptance and consumption by orangutans.

    Science.gov (United States)

    Hardus, Madeleine E; Lameira, Adriano R; Wich, Serge A; de Vries, Han; Wahyudi, Rachmad; Shumaker, Robert W; Menken, Steph B J

    2015-01-01

    Hundreds of rehabilitant great apes have been released into the wild, and thousands await release. However, survival rates after release can be as low as 20%. Several factors influence individuals' survival rates, one of which is the capacity to obtain an adequate diet once released. Released individuals are faced with a mixture of familiar and novel foods in an unfamiliar forest; therefore, it is important to understand how they increase acceptance and consumption of novel foods. This is especially vital for omnivorous species, such as wild great apes, which consume several hundred species of different foods. We assessed the effects of repeated exposures and sociality (i.e. co-feeding in the presence of one or more other individuals) on the acceptance and consumption of novel foods by captive orangutans (Pongo sp). Repeated exposures of food (novel, at first) did not cause an increase of acceptance of food; in other words, the orangutans did not start to eat a food item after being exposed to that food more often, but repeated exposures of food increased consumption (i.e. quantity). After repeated exposures, the orangutans also became gradually more familiar with the food, decreasing their explorative behaviour. The presence of co-feeding conspecifics resulted in an increased acceptance of the novel food by orangutans, and they ate a larger amount of said foods than when alone. Repeated exposure and sociality may benefit rehabilitant great apes in augmenting and diversifying diet and, once practiced before release, may accelerate an individuals' adaptation to their new habitat, improving survival chances. Great ape rescue, rehabilitation and reintroduction require large financial and logistic investments; however, their effectiveness may be improved at low cost and low effort through the suggested measures.

  5. Can the Palatability of Healthy, Satiety-Promoting Foods Increase with Repeated Exposure during Weight Loss?

    Science.gov (United States)

    Anguah, Katherene O.-B.; Lovejoy, Jennifer C.; Craig, Bruce A.; Gehrke, Malinda M.; Palmer, Philip A.; Eichelsdoerfer, Petra E.; McCrory, Megan A.

    2017-01-01

    Repeated exposure to sugary, fatty, and salty foods often enhances their appeal. However, it is unknown if exposure influences learned palatability of foods typically promoted as part of a healthy diet. We tested whether the palatability of pulse containing foods provided during a weight loss intervention which were particularly high in fiber and low in energy density would increase with repeated exposure. At weeks 0, 3, and 6, participants (n = 42; body mass index (BMI) 31.2 ± 4.3 kg/m2) were given a test battery of 28 foods, approximately half which had been provided as part of the intervention, while the remaining half were not foods provided as part of the intervention. In addition, about half of each of the foods (provided as part or not provided as part of the intervention) contained pulses. Participants rated the taste, appearance, odor, and texture pleasantness of each food, and an overall flavor pleasantness score was calculated as the mean of these four scores. Linear mixed model analyses showed an exposure type by week interaction effect for taste, texture and overall flavor pleasantness indicating statistically significant increases in ratings of provided foods in taste and texture from weeks 0 to 3 and 0 to 6, and overall flavor from weeks 0 to 6. Repeated exposure to these foods, whether they contained pulses or not, resulted in a ~4% increase in pleasantness ratings. The long-term clinical relevance of this small increase requires further study. PMID:28231094

  6. Mechanical Alterations Associated with Repeated Treadmill Sprinting under Heat Stress

    Science.gov (United States)

    Brocherie, Franck; Morin, Jean-Benoit; Racinais, Sébastien; Millet, Grégoire P.; Périard, Julien D.

    2017-01-01

    Purpose Examine the mechanical alterations associated with repeated treadmill sprinting performed in HOT (38°C) and CON (25°C) conditions. Methods Eleven recreationally active males performed a 30-min warm-up followed by three sets of five 5-s sprints with 25-s recovery and 3-min between sets in each environment. Constant-velocity running for 1-min at 10 and 20 km.h-1 was also performed prior to and following sprinting. Results Mean skin (37.2±0.7 vs. 32.7±0.8°C; P<0.001) and core (38.9±0.2 vs. 38.8±0.3°C; P<0.05) temperatures, together with thermal comfort (P<0.001) were higher following repeated sprinting in HOT vs. CON. Step frequency and vertical stiffness were lower (-2.6±1.6% and -5.5±5.5%; both P<0.001) and contact time (+3.2±2.4%; P<0.01) higher in HOT for the mean of sets 1–3 compared to CON. Running distance per sprint decreased from set 1 to 3 (-7.0±6.4%; P<0.001), with a tendency for shorter distance covered in HOT vs. CON (-2.7±3.4%; P = 0.06). Mean vertical (-2.6±5.5%; P<0.01), horizontal (-9.1±4.4%; P<0.001) and resultant ground reaction forces (-3.0±2.8%; P<0.01) along with vertical stiffness (-12.9±2.3%; P<0.001) and leg stiffness (-8.4±2.7%; P<0.01) decreased from set 1 to 3, independently of conditions. Propulsive power decreased from set 1 to 3 (-16.9±2.4%; P<0.001), with lower propulsive power values in set 2 (-6.6%; P<0.05) in HOT vs. CON. No changes in constant-velocity running patterns occurred between conditions, or from pre-to-post repeated-sprint exercise. Conclusions Thermal strain alters step frequency and vertical stiffness during repeated sprinting; however without exacerbating mechanical alterations. The absence of changes in constant-velocity running patterns suggests a strong link between fatigue-induced velocity decrements during sprinting and mechanical alterations. PMID:28146582

  7. Repeated stressful experiences differently affect brain dopamine receptor subtypes

    Energy Technology Data Exchange (ETDEWEB)

    Puglisi-Allegra, S.; Cabib, S. (Istituto di Psicobiologia e Psicofarmacologia (CNR), Roma (Italy)); Kempf, E.; Schleef, C. (Centre de Neurochimi, Strasbourg (Italy))

    1991-01-01

    The binding of tritiated spiperone (D2 antagonist) and tritiated SCH 23390 (D1 antagonist), in vivo, was investigated in the caudatus putamen (CP) and nucleus accumbens septi (NAS) of mice submitted to ten daily restraint stress sessions. Mice sacrificed 24 hr after the last stressful experience presented a 64% decrease of D2 receptor density (Bmax) but no changes in D1 receptor density in the NAS. In the CP a much smaller (11%) reduction of D2 receptor density was accompanied by a 10% increase of D1 receptors. These results show that the two types of dopamine (DA) receptors adapt in different or even opposite ways to environmental pressure, leading to imbalance between them.

  8. 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.

  9. Modification of hippocampal markers of synaptic plasticity by memantine in animal models of acute and repeated restraint stress: implications for memory and behavior.

    Science.gov (United States)

    Amin, Shaimaa Nasr; El-Aidi, Ahmed Amro; Ali, Mohamed Mostafa; Attia, Yasser Mahmoud; Rashed, Laila Ahmed

    2015-06-01

    Stress is any condition that impairs the balance of the organism physiologically or psychologically. The response to stress involves several neurohormonal consequences. Glutamate is the primary excitatory neurotransmitter in the central nervous system, and its release is increased by stress that predisposes to excitotoxicity in the brain. Memantine is an uncompetitive N-methyl D-aspartate glutamatergic receptors antagonist and has shown beneficial effect on cognitive function especially in Alzheimer's disease. The aim of the work was to investigate memantine effect on memory and behavior in animal models of acute and repeated restraint stress with the evaluation of serum markers of stress and the expression of hippocampal markers of synaptic plasticity. Forty-two male rats were divided into seven groups (six rats/group): control, acute restraint stress, acute restraint stress with Memantine, repeated restraint stress, repeated restraint stress with Memantine and Memantine groups (two subgroups as positive control). Spatial working memory and behavior were assessed by performance in Y-maze. We evaluated serum cortisol, tumor necrotic factor, interleukin-6 and hippocampal expression of brain-derived neurotrophic factor, synaptophysin and calcium-/calmodulin-dependent protein kinase II. Our results revealed that Memantine improved spatial working memory in repeated stress, decreased serum level of stress markers and modified the hippocampal synaptic plasticity markers in both patterns of stress exposure; in ARS, Memantine upregulated the expression of synaptophysin and brain-derived neurotrophic factor and downregulated the expression of calcium-/calmodulin-dependent protein kinase II, and in repeated restraint stress, it upregulated the expression of synaptophysin and downregulated calcium-/calmodulin-dependent protein kinase II expression.

  10. Repeated oral administration of capsaicin increases anxiety-like behaviours with prolonged stress-response in rats

    Indian Academy of Sciences (India)

    Y-J Choi; J Y Kim; S B Yoo; J-H Lee; J W Jahng

    2013-09-01

    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 counts and rostral grooming were significantly increased, and caudal grooming decreased, in capsaicin-treated rats during the ambulatory activity test. In elevated plus maze test, not only the time spent in open arms but also the percent arm entry into open arms was reduced in capsaicin-treated rats compared with control rats. In forced swim test, although swimming duration was decreased, struggling increased in the capsaicin group, immobility duration did not differ between the groups. Repeated oral capsaicin did not affect the basal levels of plasma corticosterone; however, the stress-induced elevation of plasma corticosterone was prolonged in capsaicin treated rats. Oral capsaicin exposure significantly increased c-Fos expression not only in the nucleus tractus of solitarius but also in the paraventricular nucleus. Results suggest that repeated oral exposure to capsaicin increases anxiety-like behaviours in rats, and dysfunction of the hypothalamic-pituitary-adrenal axis may play a role in its pathophysiology.

  11. The effects of repeated exposure to graphic fear appeals on cigarette packages: A field experiment.

    Science.gov (United States)

    Dijkstra, Arie; Bos, Colin

    2015-03-01

    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 cigarette packages. In this field-experiment, 118 smokers were assigned to 1 of 2 conditions with either graphic fear appeals or textual warnings on their cigarette packages. During 3 weeks, fear and disgust were assessed 6 times. The intention to quit smoking after 3 weeks and quitting activity during the 3 weeks were the dependent measures. The effects of 3 pretest individual difference moderators were tested: disengagement beliefs, number of cigarettes smoked a day, and readiness to quit. Three weeks of exposure to the graphic fear appeals led to a stronger intention to quit, but only when smokers scored low on disengagement beliefs, or were heavier smokers. In addition, smokers low in disengagement more often reported to have cut down on smoking in the graphic condition. There were no indications of habituation of fear and disgust over the 3 weeks. The effects of graphic fear appeals depended on smokers' characteristics: The moderators may explain the mixed findings in the literature. The lack of habituation may be caused by the renewal of the graphics every few days. The used field-experimental design with natural repeated exposure to graphics is promising.

  12. Acquired (dis)liking of natural cheese in different repeated exposure environment.

    Science.gov (United States)

    Go, Jung-Eun; Kim, Mi-Ran; Chung, Seo-Jin

    2017-09-01

    This study investigated the development of (dis)liking of various types of natural cheese with repeated exposures among Korean young females in two environment settings. Six types of natural cheese with varying flavor and texture characteristics were selected: Brie, Emmental, Gorgonzola, Gouda, Parmigiano-Reggiano and sharp Cheddar. The subjects were randomly divided into two groups (individual evaluation vs. social interaction) and exposed to all six types of cheeses eight times for 4 weeks. The acceptance scores for these cheeses were monitored at the beginning (first taste test) and end (second taste test) of the exposure test as well as 1 month after the completion of exposure test (third taste test). The results showed that the acceptance of cheese was affected by the cheese type and the number of test trials but not by tasting environment. The acceptance levels were higher for Brie, Gouda and sharp Cheddar than for Emmental, Gorgonzola and Parmigiano-Reggiano. When the subjects were exposed to Brie, Emmental, Gouda, and sharp Cheddar repeatedly, their acceptance level increased significantly. This study demonstrated that the liking of natural cheese can occur through repeated exposure to the cheese, but with the outcome varying with the type of cheese. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. 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.

  14. Anxiolytic profile of fluoxetine as monitored following repeated administration in animal rat model of chronic mild stress

    Directory of Open Access Journals (Sweden)

    Muhammad Farhan

    2016-09-01

    Full Text Available Background: Fluoxetine, a selective serotonin re-uptake inhibitor (SSRI, has been proposed to be more effective as an antidepressive drug as compared to other SSRIs. After chronic SSRI administration, the increase in synaptic levels of 5-HT leads to desensitization of somatodentritic 5-HT autoreceptors in the raphe nuclei. Chronic stress may alter behavioral, neurochemical and physiological responses to drug challenges and novel stressors. Methods: Twenty four male rats were used in this study. Animals of CMS group were exposed to CMS. Animals of stressed and unstressed group were administrated with fluoxetine at dose of 1.0 mg/kg s well as 5.0 mg/kg repeatedly for 07 days 1 h before exposed to CMS. The objective of the present study was to evaluate that repeated treatment with fluoxetine could attenuate CMS-induced behavioral deficits. Results: Treatment with fluoxetine attenuated CMS-induced behavioral deficits. Fluoxetine administration induced hypophagia in unstressed as well as CMS rats. Acute and repeated administration of fluoxetine increased motor activity in familiar environment but only repeated administration increased exploratory activity in open field. Anxiolytic effects of fluoxetine were greater in unstressed rats. These anxiolytic effects were produced as result of repeated administration not on acute administration of fluoxetine at 1.0 mg/kg as well as 5.0 mg/kg. Conclusion: The present study demonstrated that CMS exposure resulted into behavioral deficits and produced depressive-like symptoms. Fluoxetine, an SSRI, administration attenuated behavioral deficits induced by CMS. Anxiolytic effects of repeated fluoxetine administration were greater in unstressed than CMS animals.

  15. 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.

  16. Repeated exposure to sublethal doses of the organophosphorus compound VX activates BDNF expression in mouse brain.

    Science.gov (United States)

    Pizarro, Jose M; Chang, Wenling E; Bah, Mariama J; Wright, Linnzi K M; Saviolakis, George A; Alagappan, Arun; Robison, Christopher L; Shah, Jinesh D; Meyerhoff, James L; Cerasoli, Douglas M; Midboe, Eric G; Lumley, Lucille A

    2012-04-01

    The highly toxic organophosphorus compound VX [O-ethyl S-[2-(diisopropylamino)ethyl]methylphosphonate] is an irreversible inhibitor of the enzyme acetylcholinesterase (AChE). Prolonged inhibition of AChE increases endogenous levels of acetylcholine and is toxic at nerve synapses and neuromuscular junctions. We hypothesized that repeated exposure to sublethal doses of VX would affect genes associated with cell survival, neuronal plasticity, and neuronal remodeling, including brain-derived neurotrophic factor (BDNF). We examined the time course of BDNF expression in C57BL/6 mouse brain following repeated exposure (1/day × 5 days/week × 2 weeks) to sublethal doses of VX (0.2 LD(50) and 0.4 LD(50)). BDNF messenger RNA expression was significantly (p VX exposure. BDNF protein expression, however, was only increased in the CA3 region of the hippocampus. Whether increased BDNF in response to sublethal doses of VX exposure is an adaptive response to prevent cellular damage or a precursor to impending brain damage remains to be determined. If elevated BDNF is an adaptive response, exogenous BDNF may be a potential therapeutic target to reduce the toxic effects of nerve agent exposure.

  17. HEARING LOSS IN THE RHESUS MONKEY AFTER REPEATED EXPOSURES TO IDENTICAL NOISES,

    Science.gov (United States)

    hearing loss in monkeys. Five animals were exposed to repeated single-pulse noises alternately at 72- and 96-hour intervals, to observe intersubject and intra-subject variations in hearing behavior under similar physical-noise conditions. Audiograms were taken periodically, from two minutes after exposure to 72 hours later, for 2 and 4 kc test tones. There were distinctive differences in individual-animal patterns of hearing loss and recovery. Two animals clearly showed smaller hearing losses during the later exposure sessions, and that loss

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

    Energy Technology Data Exchange (ETDEWEB)

    Michel, Morgane; Jacob, Sophie [Institute for Radiological Protection and Nuclear Safety, IRSN/DRPH/SRBE/Laboratoire d' Epidemiologie, BP 17, 92 262 Fontenay-aux-Roses (France); Roger, Gilles [Otolaryngology Department, Trousseau Hospital, Paris (France); Pelosse, Beatrice [Ophthalmology Department, Trousseau Hospital, Paris (France); Laurier, Dominique [Institute for Radiological Protection and Nuclear Safety, IRSN/DRPH/SRBE/Laboratoire d' Epidemiologie, BP 17, 92 262 Fontenay-aux-Roses (France); Le Pointe, Hubert Ducou [Radiology Department, Trousseau Hospital, Paris (France); Bernier, Marie-Odile, E-mail: marie-odile.bernier@irsn.fr [Institute for Radiological Protection and Nuclear Safety, IRSN/DRPH/SRBE/Laboratoire d' Epidemiologie, BP 17, 92 262 Fontenay-aux-Roses (France)

    2012-08-15

    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.

  19. 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.

  20. Influence of repeated daily menthol exposure on human temperature regulation and perception.

    Science.gov (United States)

    Gillis, D Jason; Weston, Neil; House, James R; Tipton, Michael J

    2015-02-01

    A single exposure to menthol can, depending on concentration, enhance both cool sensations and encourage body heat storage. This study tested whether there is an habituation in either response after repeated-daily exposures. Twenty-two participants were assigned to one of three spray groups: Control (CON; n=6), 0.05% L-menthol (M(0.05%); n=8), and 0.2% L-menthol (M(0.2%); n=8). On Monday (20°C, 50% rh) participants were sprayed with 100 mL of solution and undertook 40 min of cycling at 45% of their peak power (Ex1), from Tuesday to Thursday (30°C, 50% rh) they were sprayed twice daily whilst resting (R1 to R6), Friday was a repeat of Monday (Ex2). Thermal sensation (TS), thermal comfort, perceived exertion, irritation, rectal and skin temperature (Tsk), skin blood flow (SkBF) and sweat rate were monitored. A two-way ANOVA (alpha=0.05) compared responses from the beginning (Ex1, R1) and end (Ex2, R5) of the testing week. M(0.2%) induced significantly (PMenthol caused a heat storage response, mediated by vasoconstriction, at the beginning and end of the week, suggesting the habituation of TS occurred in a pathway specific to sensation. In summary, the cooling influence of 0.2% menthol habituates after repeated-daily exposures, but with no habituation in heat storage.

  1. Repeated stressors do not provoke habituation or accumulation of the stress response in the catfish Rhamdia quelen

    Directory of Open Access Journals (Sweden)

    Gessi Koakoski

    2013-06-01

    Full Text Available Fish repeatedly experience stressful situations under experimental and aquaculture conditions, even in their natural habitat. Fish submitted to sequential stressors can exhibit accumulation or habituation on its cortisol response. We posed a central question about the cortisol response profiles after exposure to successive acute stressors of a similar and different nature in Rhamdia quelen. We have shown that successive acute stressors delivered with 12-h, 48-h, and 1-week intervals provoked similar cortisol responses in juvenile R. quelen, without any habituation or accumulation. The cumulative stress response is more associated to short acute stressors with very short intervals of minutes to hours. In our work, we used an interval as short as 12h, and no cumulative response was found. However, if the length of time between stressors is of a day or week as used in our work the most common and an expected phenomenon is the attenuation of the response. Thus, also, the absence of both accumulation of the stress response and the expected habituation is an intriguing result. Our results show that R. quelen does not show habituation or accumulation in its stress responses to repeated stressors, as reported for other fish species

  2. Over-representation of repeats in stress response genes: a strategy to increase versatility under stressful conditions?

    Science.gov (United States)

    Rocha, Eduardo P C; Matic, Ivan; Taddei, François

    2002-05-01

    The survival of individual organisms facing stress is enhanced by the induction of a set of changes. As the intensity, duration and nature of stress is highly variable, the optimal response to stress may be unpredictable. To face such an uncertain future, it may be advantageous for a clonal population to increase its phenotypic heterogeneity (bet-hedging), ensuring that at least a subset of cells would survive the current stress. With current techniques, assessing the extent of this variability experimentally remains a challenge. Here, we use a bioinformatic approach to compare stress response genes with the rest of the genome for the presence of various kinds of repeated sequences, elements known to increase variability during the transfer of genetic information (i.e. during replication, but also during gene expression). We investigated the potential for illegitimate and homologous recombination of 296 Escherichia coli genes related to repair, recombination and physiological adaptations to different stresses. Although long repeats capable of engaging in homologous recombination are almost absent in stress response genes, we observed a significant high number of short close repeats capable of inducing phenotypic variability by slipped-mispair during DNA, RNA or protein synthesis.

  3. 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.

  4. Seroepidemiological studies indicate frequent and repeated exposure to Campylobacter spp. during childhood.

    Science.gov (United States)

    Ang, C W; Teunis, P F M; Herbrink, P; Keijser, J; Van Duynhoven, Y H T P; Visser, C E; Van Pelt, W

    2011-09-01

    The annual number of episodes of clinical gastroenteritis caused by Campylobacter spp. in The Netherlands is estimated to be 75 000, i.e. once per 200 person life-years. This number is based on extrapolation of culture results from population-based studies. The number of culture-confirmed cases of Campylobacter infection peaks in the first 3 years of life and again between the ages of 20 and 25 years. The seroepidemiology of Campylobacter describes the relationship between age and exposure to Campylobacter and reflects both symptomatic and asymptomatic infections. Using a validated ELISA system, antibodies to Campylobacter were measured in an age-stratified sample (n=456) of the PIENTER serum collection of the Dutch general population. The seroprevalence of Campylobacter IgG antibodies increased with age, reaching almost 100% at age 20 years. Antibody levels steadily increased with age until young adulthood, suggesting repeated exposure to Campylobacter. In conclusion, seroepidemiological data demonstrated repeated exposures to Campylobacter throughout life, most of which do not lead to clinical symptoms. From young adulthood, >95% of the population in The Netherlands had serological evidence for exposure to Campylobacter.

  5. 5-Day repeated inhalation and 28-day post-exposure study of graphene.

    Science.gov (United States)

    Shin, Jae Hoon; Han, Sung Gu; Kim, Jin Kwon; Kim, Boo Wook; Hwang, Joo Hwan; Lee, Jong Seong; Lee, Ji Hyun; Baek, Jin Ee; Kim, Tae Gyu; Kim, Keun Soo; Lee, Heon Sang; Song, Nam Woong; Ahn, Kangho; Yu, Il Je

    2015-01-01

    Graphene has recently been attracting increasing attention due to its unique electronic and chemical properties and many potential applications in such fields as semiconductors, energy storage, flexible electronics, biosensors and medical imaging. However, the toxicity of graphene in the case of human exposure has not yet been clarified. Thus, a 5-day repeated inhalation toxicity study of graphene was conducted using a nose-only inhalation system for male Sprague-Dawley rats. A total of three groups (20 rats per group) were compared: (1) control (ambient air), (2) low concentration (0.68 ± 0.14 mg/m(3) graphene) and (3) high concentration (3.86 ± 0.94 mg/m(3) graphene). The rats were exposed to graphene for 6 h/day for 5 days, followed by recovery for 1, 3, 7 or 28 days. The bioaccumulation and macrophage ingestion of the graphene were evaluated in the rat lungs. The exposure to graphene did not change the body weights or organ weights of the rats after the 5-day exposure and during the recovery period. No statistically significant difference was observed in the levels of lactate dehydrogenase, protein and albumin between the exposed and control groups. However, graphene ingestion by alveolar macrophages was observed in the exposed groups. Therefore, these results suggest that the 5-day repeated exposure to graphene only had a minimal toxic effect at the concentrations and time points used in this study.

  6. Myricetin Attenuates Depressant-Like Behavior in Mice Subjected to Repeated Restraint Stress

    Directory of Open Access Journals (Sweden)

    Zegang Ma

    2015-11-01

    Full Text Available Increasing evidence has shown that oxidative stress may be implicated in chronic stress-induced depression. Several flavonoids with anti-oxidative effects have been proved to be anti-depressive. Myricetin is a well-defined flavonoid with the anti-oxidative, anti-inflammatory, anti-apoptotic, and neuroprotective properties. The aim of the present study is to investigate the possible effects of chronic administration of myricetin on depressant-like behaviors in mice subjected to repeated restraint (4 h/day for 21 days. Our results showed that myricetin administration specifically reduced the immobility time in mice exposed to chronic stress, as tested in both forced swimming test and tail suspension test. Myricetin treatment improved activities of glutathione peroxidase (GSH-PX in the hippocampus of stressed mice. In addition, myricetin treatment decreased plasma corticosterone levels of those mice subjected to repeated restraint stress. The effects of myricetin on the brain-derived neurotrophic factor (BDNF levels in hippocampus were also investigated. The results revealed that myricetin normalized the decreased BDNF levels in mice subjected to repeated restraint stress. These findings provided more evidence that chronic administration of myricetin improves helpless behaviors. The protective effects of myricetin might be partially mediated by an influence on BDNF levels and might be attributed to myricetin-mediated anti-oxidative stress in the hippocampus.

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

    Science.gov (United States)

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

    1990-05-01

    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. Exposure to the same level of benzene for an additional 2 weeks did not further increase the frequency of micronuclei in PCEs. These results indicate

  8. 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.

  9. 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.

  10. 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.

  11. Changes in Liver Proteome Expression of Senegalese Sole (Solea senegalensis) in Response to Repeated Handling Stress

    DEFF Research Database (Denmark)

    Cordeiro, O. D.; Silva, Tomé Santos; Alves, R. N.

    2012-01-01

    the detection of 287 spots significantly affected by repeated handling stress (Wilcoxon–Mann–Whitney U test, p stress seems to have affected protein synthesis, folding and turnover (40S ribosomal protein S12...... hormone metabolism (3-oxo-5-β-steroid 4-dehydrogenase), and purine salvage (hypoxanthine phosphoribosyltransferase). Further characterization is required to fully assess the potential of these markers for the monitoring of fish stress response to chronic stressors of aquaculture environment.......The Senegalese sole, a high-value flatfish, is a good candidate for aquaculture production. Nevertheless, there are still issues regarding this species’ sensitivity to stress in captivity. We aimed to characterize the hepatic proteome expression for this species in response to repeated handling...

  12. 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.

  13. The estrous cycle of the ewe is resistant to disruption by repeated, acute psychosocial stress.

    Science.gov (United States)

    Wagenmaker, Elizabeth R; Breen, Kellie M; Oakley, Amy E; Tilbrook, Alan J; Karsch, Fred J

    2010-06-01

    Five experiments were conducted to test the hypothesis that psychosocial stress interferes with the estrous cycle of sheep. In experiment 1, ewes were repeatedly isolated during the follicular phase. Timing, amplitude, and duration of the preovulatory luteinizing hormone (LH) surge were not affected. In experiment 2, follicular-phase ewes were subjected twice to a "layered stress" paradigm consisting of sequential, hourly application of isolation, restraint, blindfold, and predator cues. This reduced the LH pulse amplitude but did not affect the LH surge. In experiment 3, different acute stressors were given sequentially within the follicular phase: food denial plus unfamiliar noises and forced exercise, layered stress, exercise around midnight, and transportation. This, too, did not affect the LH surge. In experiment 4, variable acute psychosocial stress was given every 1-2 days for two entire estrous cycles; this did not disrupt any parameter of the cycle monitored. Lastly, experiment 5 examined whether the psychosocial stress paradigms of experiment 4 would disrupt the cycle and estrous behavior if sheep were metabolically stressed by chronic food restriction. Thirty percent of the food-restricted ewes exhibited deterioration of estrous cycle parameters followed by cessation of cycles and failure to express estrous behavior. However, disruption was not more evident in ewes that also encountered psychosocial stress. Collectively, these findings indicate the estrous cycle of sheep is remarkably resistant to disruption by acute bouts of psychosocial stress applied intermittently during either a single follicular phase or repeatedly over two estrous cycles.

  14. Heat stress impairs repeated jump ability after competitive elite soccer games

    DEFF Research Database (Denmark)

    Mohr, Magni; Krustrup, Peter

    2013-01-01

    ABSTRACT:: The present study examined the effect of environmental heat stress on repeated jump performance after elite competitive soccer games. Male elite soccer players (n=19) from two Scandinavian teams participated (age; 26.7±1.0 yrs, height; 181.7±1.1 cm, body mass; 75.8±1.0 kg). The players...

  15. Reversible inactivation of rostral nucleus raphe pallidus attenuates acute autonomic responses but not their habituation to repeated audiogenic stress in rats.

    Science.gov (United States)

    Nyhuis, Tara J; Masini, Cher V; Taufer, Kirsten L; Day, Heidi E W; Campeau, Serge

    2016-01-01

    The medullary nucleus raphe pallidus (RPa) mediates several autonomic responses evoked by acute stress exposure, including tachycardia and hyperthermia. The present study assessed whether the RPa contributes to the decline/habituation of these responses observed during repeated audiogenic stress. Adult male rats were implanted with cannulae aimed at the RPa, and abdominal E-mitters that wirelessly acquire heart rate and core body temperature. After surgical recovery, animals were injected with muscimol or vehicle (aCSF) in the RPa region, followed by 30 min of 95-dBA loud noise or no noise control exposures on 3 consecutive days at 24-h intervals. Forty-eight hours after the third exposure, animals were exposed to an additional, but injection-free, loud noise or no noise test to assess habituation of hyperthermia and tachycardia. Three days later, rats were restrained for 30-min to evaluate their ability to display normal acute autonomic responses following the repeated muscimol injection regimen. The results indicated that the inhibition of cellular activity induced by the GABAA-receptor agonist muscimol centered in the RPa region reliably attenuated acute audiogenic stress-evoked tachycardia and hyperthermia, compared with vehicle-injected rats. Animals in the stress groups exhibited similar attenuated tachycardia and hyperthermia during the injection-free fourth audiogenic stress exposure, and displayed similar and robust increases in these responses to the subsequent restraint test. These results suggest that cellular activity in neurons of the RPa region is necessary for the expression of acute audiogenic stress-induced tachycardia and hyperthermia, but may not be necessary for the acquisition of habituated tachycardic responses to repeated stress.

  16. Virtual nature environment with nature sound exposure induce stress recovery by enhanced parasympathetic activity

    DEFF Research Database (Denmark)

    Annerstedt, Matilda; Jönsson, Peter; Wallergård, Mattias

    2013-01-01

    Experimental research on stress recovery in natural environments is limited, as is study of the effect of sounds of nature. After inducing stress by means of a virtual stress test, we explored physiological recovery in two different virtual natural environments (with and without exposure to sounds...... of nature) and in one control condition. Cardiovascular data and saliva cortisol were collected. Repeated ANOVA measurements indicated parasympathetic activation in the group subjected to sounds of nature in a virtual natural environment, suggesting enhanced stress recovery may occur in such surroundings....... The group that recovered in virtual nature without sound and the control group displayed no particular autonomic activation or deactivation. The results demonstrate a potential mechanistic link between nature, the sounds of nature, and stress recovery, and suggest the potential importance of virtual reality...

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

    Science.gov (United States)

    Kelly, Christopher R; Grinband, Jack; Hirsch, Joy

    2007-12-05

    Media depictions of violence, although often claimed to induce viewer aggression, have not been shown to affect the cortical networks that regulate behavior. 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. 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.

  18. The response of human nasal and bronchial organotypic tissue cultures to repeated whole cigarette smoke exposure.

    Science.gov (United States)

    Talikka, Marja; Kostadinova, Radina; Xiang, Yang; Mathis, Carole; Sewer, Alain; Majeed, Shoaib; Kuehn, Diana; Frentzel, Stefan; Merg, Celine; Geertz, Marcel; Martin, Florian; Ivanov, Nikolai V; Peitsch, Manuel C; Hoeng, Julia

    2014-01-01

    Exposure to cigarette smoke (CS) is linked to the development of respiratory diseases, and there is a need to understand the mechanisms whereby CS causes damage. Although animal models have provided valuable insights into smoking-related respiratory tract damage, modern toxicity testing calls for reliable in vitro models as alternatives for animal experimentation. We report on a repeated whole mainstream CS exposure of nasal and bronchial organotypic tissue cultures that mimic the morphological, physiological, and molecular attributes of the human respiratory tract. Despite the similar cellular staining and cytokine secretion in both tissue types, the transcriptomic analyses in the context of biological network models identified similar and diverse biological processes that were impacted by CS-exposed nasal and bronchial cultures. Our results demonstrate that nasal and bronchial tissue cultures are appropriate in vitro models for the assessment of CS-induced adverse effects in the respiratory system and promising alternative to animal experimentation.

  19. Permanent relief from intermittent cold stress-induced fibromyalgia-like abnormal pain by repeated intrathecal administration of antidepressants

    Directory of Open Access Journals (Sweden)

    Mukae Takehiro

    2011-09-01

    Full Text Available Abstract Background Fibromyalgia (FM is characterized by chronic widespread pain, which is often refractory to conventional painkillers. Numerous clinical studies have demonstrated that antidepressants are effective in treating FM pain. We previously established a mouse model of FM-like pain, induced by intermittent cold stress (ICS. Results In this study, we find that ICS exposure causes a transient increase in plasma corticosterone concentration, but not in anxiety or depression-like behaviors. A single intrathecal injection of an antidepressant, such as milnacipran, amitriptyline, mianserin or paroxetine, had an acute analgesic effect on ICS-induced thermal hyperalgesia at post-stress day 1 in a dose-dependent manner. In addition, repeated daily antidepressant treatments during post-stress days 1-5 gradually reversed the reduction in thermal pain threshold, and this recovery was maintained for at least 7 days after the final treatment. In addition, relief from mechanical allodynia, induced by ICS exposure, was also observed at day 9 after the cessation of antidepressant treatment. In contrast, the intravenous administration of these antidepressants at conventional doses failed to provide relief. Conclusions These results suggest that the repetitive intrathecal administration of antidepressants permanently cures ICS-induced FM pain in mice.

  20. 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.

  1. Repeating seismicity in the shallow crust modulated by transient stress perturbations

    Science.gov (United States)

    Frank, William B.; Shapiro, Nikolaï M.; Husker, Allen L.; Kostoglodov, Vladimir; Campillo, Michel

    2016-09-01

    Recent studies have reported seismic phenomena that are modulated by small stress perturbations (∼10 kPa), revealing their critically stressed nature. Such observations have been principally limited to plate interfaces with their occurrence linked to high fluid pore-pressure. In this study, we report observations of nine repeating seismic sources in the shallow crust in Guerrero, Mexico that emit events at rates comparable to other seismic phenomena in low stress environments. Testing their susceptibility to small stress perturbations, we find that all nine sources appear to be modulated by mining activity, tides, and a large slow slip event (Mw 7.5). Our results suggest that the fault conditions necessary for low effective stress seismicity can occur away from plate interfaces.

  2. Childhood poverty and health: cumulative risk exposure and stress dysregulation.

    Science.gov (United States)

    Evans, Gary W; Kim, Pilyoung

    2007-11-01

    A massive literature documents the inverse association between poverty or low socioeconomic status and health, but little is known about the mechanisms underlying this robust relation. We examined longitudinal relations between duration of poverty exposure since birth, cumulative risk exposure, and physiological stress in two hundred seven 13-year-olds. Chronic stress was assessed by basal blood pressure and overnight cortisol levels; stress regulation was assessed by cardiovascular reactivity to a standard acute stressor and recovery after exposure to this stressor. Cumulative risk exposure was measured by multiple physical (e.g., substandard housing) and social (e.g., family turmoil) risk factors. The greater the number of years spent living in poverty, the more elevated was overnight cortisol and the more dysregulated was the cardiovascular response (i.e., muted reactivity). Cardiovascular recovery was not affected by duration of poverty exposure. Unlike the duration of poverty exposure, concurrent poverty (i.e., during adolescence) did not affect these physiological stress outcomes. The effects of childhood poverty on stress dysregulation are largely explained by cumulative risk exposure accompanying childhood poverty.

  3. Behavioural, endocrine and immune responses to repeated social stress in pregnant gilts.

    Science.gov (United States)

    Couret, D; Otten, W; Puppe, B; Prunier, A; Merlot, E

    2009-01-01

    Pregnant sows are exposed to various stressors in intensive pig husbandry that may have negative consequences on their health, reproductive performances and welfare. Social stress is one of these challenges, because gestating sows have to be housed in groups according to EU guidelines (2001/88/CE). The purpose of this study was to determine the consequences of repeated social stress in pregnant female pigs on their behavioural, endocrine and immunological responses and on pregnancy outcome. Pregnant gilts were submitted to a repeated social stress procedure induced by housing unfamiliar gilts in pairs changed twice a week between days 77 and 105 of gestation (S group, n = 18). Control gilts were housed in stable pairs during the same period (C group, n = 18). Agonistic behaviour was observed during the first 3 h after each grouping. Skin lesions were numbered 2 h after each grouping. Salivary cortisol was measured before and repeatedly during the 4 weeks of grouping. Gilts were immunized against keyhole limpet haemocyanin (KLH) on days 81 and 95 of gestation. Immunoglobulins G against KLH, proliferative responses to concanavalin A, lipopolysaccharide, pokeweed mitogen and KLH and peripheral blood leukocyte numbers were evaluated 1 week before the first grouping and 3 days after the last one. Agonistic interactions and skin lesions were observed in S gilts at each grouping, although there was a decline between the first and the last grouping (P Gestation length tended to be shorter in S gilts (P = 0.09), but litter size, piglet weight or mortality at birth were not affected. Variability of the response of S gilts to groupings was partly explained by their average success value determined according to the outcome (defeat or win) of all the groupings. In conclusion, our study demonstrates that the application of repeated social stress to pregnant gilts during the last third of their gestation repeatedly activates their hypothalamo-pituitary-adrenal axis but does not

  4. 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.

  5. Mitochondrial oxidative stress and dysfunction in rat brain induced by carbofuran exposure.

    Science.gov (United States)

    Kamboj, Sukhdev Singh; Kumar, Vikas; Kamboj, Amit; Sandhir, Rajat

    2008-11-01

    Repeated low-dose exposure to carbofuran exerts its neurotoxic effects by non-cholinergic mechanisms. Emerging evidence indicates that oxidative stress plays an important role in carbofuran neurotoxicity after sub-chronic exposure. The purpose of the present study is to evaluate the role of mitochondrial oxidative stress and dysfunction as a primary event responsible for neurotoxic effects observed after sub-chronic carbofuran exposure. Carbofuran was administered to rats at a dose of 1 mg/kg orally for a period of 28 days. There was a significant inhibition in the activity of acetylcholinesterase (66.6%) in brain samples after 28 days of carbofuran exposure. Mitochondrial respiratory chain functions were assessed in terms of MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) reduction and activity of succinate dehydrogenase in isolated mitochondria. It was observed that carbofuran exposure significantly inhibited MTT reduction (31%) and succinate dehydrogenase activity (57%). This was accompanied by decrease in low-molecular weight thiols (66.6%) and total thiols (37.4%) and an increase in lipid peroxidation (43.7%) in the mitochondria isolated from carbofuran-exposed rat brain. The changes in mitochondrial oxidative stress and functions were associated with impaired cognitive and motor functions in the animals exposed to carbofuran as compared to the control animals. Based on these results, it is clear that carbofuran exerts its neurotoxicity by impairing mitochondrial functions leading to oxidative stress and neurobehavioral deficits.

  6. Stress Exposure, Food Intake, and Emotional State

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    Ulrich-Lai, Yvonne M.; Fulton, Stephanie; Wilson, Mark; Petrovich, Gorica; Rinaman, Linda

    2016-01-01

    This manuscript summarizes the proceedings of the symposium entitled, “Stress, Palatable Food and Reward”, that was chaired by Drs. Linda Rinaman and Yvonne Ulrich-Lai at the 2014 Neurobiology of Stress Workshop held in Cincinnati, OH. This symposium comprised research presentations by four neuroscientists whose work focuses on the biological bases for complex interactions among stress, food intake and emotion. First, Dr. Ulrich-Lai describes her rodent research exploring mechanisms by which the rewarding properties of sweet palatable foods confer stress relief. Second, Dr. Stephanie Fulton discusses her work in which excessive, long-term intake of dietary lipids, as well as their subsequent withdrawal, promotes stress-related outcomes in mice. Third, Dr. Mark Wilson describes his group’s research examining the effects of social hierarchy-related stress on food intake and diet choice in group-housed female rhesus macaques, and compared the data from monkeys to results obtained in analogous work using rodents. Lastly, Dr. Gorica Petrovich discusses her research program that is aimed at defining cortical–amygdalar–hypothalamic circuitry responsible for curbing food intake during emotional threat (i.e., fear anticipation) in rats. Their collective results reveal the complexity of physiological and behavioral interactions that link stress, food intake and emotional state, and suggest new avenues of research to probe the impact of genetic, metabolic, social, experiential, and environmental factors. PMID:26303312

  7. Stress exposure, food intake and emotional state.

    Science.gov (United States)

    Ulrich-Lai, Yvonne M; Fulton, Stephanie; Wilson, Mark; Petrovich, Gorica; Rinaman, Linda

    2015-01-01

    This manuscript summarizes the proceedings of the symposium entitled, "Stress, Palatable Food and Reward", that was chaired by Drs. Linda Rinaman and Yvonne Ulrich-Lai at the 2014 Neurobiology of Stress Workshop held in Cincinnati, OH. This symposium comprised research presentations by four neuroscientists whose work focuses on the biological bases for complex interactions among stress, food intake and emotion. First, Dr Ulrich-Lai describes her rodent research exploring mechanisms by which the rewarding properties of sweet palatable foods confer stress relief. Second, Dr Stephanie Fulton discusses her work in which excessive, long-term intake of dietary lipids, as well as their subsequent withdrawal, promotes stress-related outcomes in mice. Third, Dr Mark Wilson describes his group's research examining the effects of social hierarchy-related stress on food intake and diet choice in group-housed female rhesus macaques, and compared the data from monkeys to results obtained in analogous work using rodents. Finally, Dr Gorica Petrovich discusses her research program that is aimed at defining cortical-amygdalar-hypothalamic circuitry responsible for curbing food intake during emotional threat (i.e. fear anticipation) in rats. Their collective results reveal the complexity of physiological and behavioral interactions that link stress, food intake and emotional state, and suggest new avenues of research to probe the impact of genetic, metabolic, social, experiential and environmental factors on these interactions.

  8. The role of exposure history on HIV acquisition: insights from repeated low-dose challenge studies.

    Directory of Open Access Journals (Sweden)

    Roland R Regoes

    Full Text Available To assess the efficacy of HIV vaccine candidates or preventive treatment, many research groups have started to challenge monkeys repeatedly with low doses of the virus. Such challenge data provide a unique opportunity to assess the importance of exposure history for the acquisition of the infection. I developed stochastic models to analyze previously published challenge data. In the mathematical models, I allowed for variation of the animals' susceptibility to infection across challenge repeats, or across animals. In none of the studies I analyzed, I found evidence for an immunizing effect of non-infecting challenges, and in most studies, there is no evidence for variation in the susceptibilities to the challenges across animals. A notable exception was a challenge experiment by Letvin et al. Sci Translat Med (2011 conducted with the strain SIVsmE660. The challenge data of this experiment showed significant susceptibility variation from animal-to-animal, which is consistent with previously established genetic differences between the involved animals. For the studies which did not show significant immunizing effects and susceptibility differences, I conducted a power analysis and could thus exclude a very strong immunization effect for some of the studies. These findings validate the assumption that non-infecting challenges do not immunize an animal - an assumption that is central in the argument that repeated low-dose challenge experiments increase the statistical power of preclinical HIV vaccine trials. They are also relevant for our understanding of the role of exposure history for HIV acquisition and forecasting the epidemiological spread of HIV.

  9. Exposure to Stress: Occupational Hazards in Hospitals

    Science.gov (United States)

    ... communications, and # # the balance between personal safety and duty-to- care. Health care workers who experience a ... a predictive model based on work assessments by employees. Work Stress 13 :266–281. Miles-Tapping [1992]. ...

  10. Variability in prefrontal hemodynamic response during exposure to repeated self-selected music excerpts, a near-infrared spectroscopy study.

    Science.gov (United States)

    Moghimi, Saba; Schudlo, Larissa; Chau, Tom; Guerguerian, Anne-Marie

    2015-01-01

    Music-induced brain activity modulations in areas involved in emotion regulation may be useful in achieving therapeutic outcomes. Clinical applications of music may involve prolonged or repeated exposures to music. However, the variability of the observed brain activity patterns in repeated exposures to music is not well understood. We hypothesized that multiple exposures to the same music would elicit more consistent activity patterns than exposure to different music. In this study, the temporal and spatial variability of cerebral prefrontal hemodynamic response was investigated across multiple exposures to self-selected musical excerpts in 10 healthy adults. The hemodynamic changes were measured using prefrontal cortex near infrared spectroscopy and represented by instantaneous phase values. Based on spatial and temporal characteristics of these observed hemodynamic changes, we defined a consistency index to represent variability across these domains. The consistency index across repeated exposures to the same piece of music was compared to the consistency index corresponding to prefrontal activity from randomly matched non-identical musical excerpts. Consistency indexes were significantly different for identical versus non-identical musical excerpts when comparing a subset of repetitions. When all four exposures were compared, no significant difference was observed between the consistency indexes of randomly matched non-identical musical excerpts and the consistency index corresponding to repetitions of the same musical excerpts. This observation suggests the existence of only partial consistency between repeated exposures to the same musical excerpt, which may stem from the role of the prefrontal cortex in regulating other cognitive and emotional processes.

  11. 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 repeate

  12. 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 repeate

  13. STRESS-STRAIN STATE IN EMBEDMENT OF REINFORCEMENT IN CASE OF REPEATED LOADINGS

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    Mirsayapov Ilshat Talgatovich

    2016-05-01

    Full Text Available The author offer transforming the diagram of ideal elastic-plastic deformations for the description of the stress-strain state of embedment of reinforcement behind a critical inclined crack at repeatedly repeating loadings. The endurance limit of the adhesion between concrete and reinforcement and its corresponding displacements in case of repeated loadings are accepted as the main indicators. This adhesion law is the most appropriate for the description of physical and mechanical phenomena in the contact zone in case of cyclic loading, because it simply and reliably describes the adhesion mechanism and the nature of the deformation, and greatly simplifies the endurance calculations compared to the standard adhesion law. On the basis of this diagram the author obtained the equations for the description of the distribution of pressures and displacements after cyclic loading with account for the development of deformations of cyclic creep of the concrete under the studs of reinforcement.

  14. Harm expectancy violation during exposure therapy for posttraumatic stress disorder.

    Science.gov (United States)

    de Kleine, Rianne A; Hendriks, Lotte; Becker, Eni S; Broekman, Theo G; van Minnen, Agnes

    2017-06-01

    Exposure therapy has proven efficacy in the treatment of posttraumatic stress disorder (PTSD). Emotional processing theory proposes that fear habituation is a central mechanism in symptom reduction, but the empirical evidence supporting this is mixed. Recently it has been proposed that violation of harm expectancies is a crucial mechanism of action in exposure therapy. But to date, changes in harm expectancies have not been examined during exposure therapy in PTSD. The goal of the current study was to examine harm expectancy violation as mechanism of change in exposure therapy for posttraumatic stress disorder (PTSD). Patients (N=50, 44 female) with a primary diagnosis of chronic PTSD received intensive exposure therapy. Harm expectancies, harm experiences and subjective units of distress (SUDs) were assessed at each imaginal exposure session, and PTSD symptoms were assessed pre- and posttreatment with the Clinician Administered PTSD Scale (CAPS). Results showed that harm expectancies were violated within and strongly declined in-between exposure therapy sessions. However, expectancy violation was not related to PTSD symptom change. Fear habituation measures were moderately related to PTSD symptom reductions. In line with theory, exposure therapy promotes expectancy violation in PTSD patients, but this is not related to exposure therapy outcome. More work is warranted to investigate mechanisms of change during exposure therapy in PTSD. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. 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.

  16. Repeated cocaine exposure increases fast-spiking interneuron excitability in the rat medial prefrontal cortex.

    Science.gov (United States)

    Campanac, Emilie; Hoffman, Dax A

    2013-06-01

    The medial prefrontal cortex plays a key role in cocaine addiction. However, how chronic cocaine exposure affects cortical networks remains unclear. Most studies have focused on layer 5 pyramidal neurons (the circuit output), while the response of local GABAergic interneurons to cocaine remains poorly understood. Here, we recorded from fast-spiking interneurons (FS-IN) after repeated cocaine exposure and found altered membrane excitability. After cocaine withdrawal, FS-IN showed an increase in the number of spikes evoked by positive current injection, increased input resistance, and decreased hyperpolarization-activated current. We also observed a reduction in miniature excitatory postsynaptic currents, whereas miniature inhibitory postsynaptic current activity was unaffected. We show that, in animals with cocaine history, dopamine receptor D(2) activation is less effective in increasing FS-IN intrinsic excitability. Interestingly, these alterations are only observed 1 wk or more after the last cocaine exposure. This suggests that the dampening of D(2)-receptor-mediated response may be a compensatory mechanism to rein down the excitability of FS-IN.

  17. Neurobehavioral risk is associated with gestational exposure to stress hormones.

    Science.gov (United States)

    Sandman, Curt A; Davis, Elysia Poggi

    2012-07-01

    The developmental origins of disease or fetal programming model predict that early exposures to threat or adverse conditions have lifelong consequences that result in harmful outcomes for health. The maternal endocrine 'fight or flight' system is a source of programming information for the human fetus to detect threats and adjust their developmental trajectory for survival. Fetal exposures to intrauterine conditions including elevated stress hormones increase the risk for a spectrum of health outcomes depending on the timing of exposure, the timetable of organogenesis and the developmental milestones assessed. Recent prospective studies, reviewed here, have documented the neurodevelopmental consequences of fetal exposures to the trajectory of stress hormones over the course of gestation. These studies have shown that fetal exposures to biological markers of adversity have significant and largely negative consequences for fetal, infant and child emotional and cognitive regulation and reduced volume in specific brain structures.

  18. Assessing variability and comparing short-term biomarkers of styrene exposure using a repeated measurements approach.

    Science.gov (United States)

    Fustinoni, S; Manini, P; Campo, L; De Palma, G; Andreoli, R; Mutti, A; Bertazzi, P A; Rappaport, S M

    2010-01-15

    The aim of this work is to compare several short-term biomarkers of styrene exposure, namely urinary styrene (StyU), mercapturic acids (M1+M2), mandelic acid (MA), phenylglyoxylic acid (PGA), phenylglycine (PHG), and 4-vinylphenol conjugates (VP), for use as biomarkers of exposure in epidemiologic studies. A repeated measurements protocol (typically 4 measurements per worker over 6 weeks) was applied to measure airborne styrene (StyA) and urinary biomarkers in 10 varnish and 8 fiberglass reinforced plastic workers. Estimated geometric mean personal exposures to StyA were 2.96mg/m(3) in varnish workers and 15.7mg/m(3) in plastic workers. The corresponding levels of StyU, M1+M2, MA, PGA, MA+PGA, PHG and VP were 5.13microg/L, 0.111, 38.2, 22.7, 62.6, 0.978, and 3.97mg/g creatinine in varnish workers and 8.38microg/L, 0.303, 146, 83.4, 232, 2.85 and 3.97mg/g creatinine in plastic workers. Within-worker (sigma(wY)(2)) and between-worker (sigma(bY)(2)) variance components were estimated from the log-transformed data as were the corresponding fold ranges containing 95% of the respective lognormal distributions of daily levels ((w)R(0.95)) and subject-specific mean levels ((b)R(0.95)). Estimates of (w)R(0.95) (range: 4-26) were generally smaller than those of (b)R(0.95) (range: 5-790) for both environmental and biological markers; this indicates that exposures varied much more between workers than within workers in these groups. Since attenuation bias in an estimated exposure-response relationship increases with the variance ratio lambda=sigma(wY)(2)/sigma(bY)(2), we estimated values of lambda for all exposure measures in our study. Values of lambda were typically much less than one (median=0.220) and ranged from 0.089 for M1+M2 in plastic workers to 1.38 for PHG in varnish workers. Since values of lambda were 0.147 and 0.271 for StyA in varnish workers and plastic workers, respectively, compared to 0.178 and 0.210 for MA in the same groups, our results suggest that either

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

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    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

  20. Distinct effects of repeated restraint stress on basolateral amygdala neuronal membrane properties in resilient adolescent and adult rats.

    Science.gov (United States)

    Hetzel, Andrea; Rosenkranz, J Amiel

    2014-08-01

    Severe and repeated stress has damaging effects on health, including initiation of depression and anxiety. Stress that occurs during development has long-lasting and particularly damaging effects on emotion. The basolateral amygdala (BLA) plays a key role in many affective behaviors, and repeated stress causes different forms of BLA hyperactivity in adolescent and adult rats. However, the mechanism is not known. Furthermore, not every individual is susceptible to the negative consequences of stress. Differences in the effects of stress on the BLA might contribute to determine whether an individual will be vulnerable or resilient to the effects of stress on emotion. The purpose of this study is to test the cellular underpinnings for age dependency of BLA hyperactivity after stress, and whether protective changes occur in resilient individuals. To test this, the effects of repeated stress on membrane excitability and other membrane properties of BLA principal neurons were compared between adult and adolescent rats, and between vulnerable and resilient rats, using in vitro whole-cell recordings. Vulnerability was defined by adrenal gland weight, and verified by body weight gain after repeated restraint stress, and fecal pellet production during repeated restraint sessions. We found that repeated stress increased the excitability of BLA neurons, but in a manner that depended on age and BLA subnucleus. Furthermore, stress resilience was associated with an opposite pattern of change, with increased slow afterhyperpolarization (AHP) potential, whereas vulnerability was associated with decreased medium AHP. The opposite outcomes in these two populations were further distinguished by differences of anxiety-like behavior in the elevated plus maze that were correlated with BLA neuronal excitability and AHP. These results demonstrate a substrate for BLA hyperactivity after repeated stress, with distinct membrane properties to target, as well as age-dependent factors that

  1. Enhanced learning deficits in female rats following lifetime pb exposure combined with prenatal stress.

    Science.gov (United States)

    Cory-Slechta, Deborah A; Stern, Sander; Weston, Doug; Allen, Joshua L; Liu, Sue

    2010-10-01

    Pb (lead) exposure and stress are co-occurring risk factors (particularly in low socioeconomic communities) that also act on common biological substrates and produce common adverse outcomes, including cognitive impairments. This study sought to determine whether lifetime Pb exposure combined with prenatal stress would enhance the cognitive deficits independently associated with each of these risk factors and to explore associated mechanisms of any observed impairments. Learning was evaluated using a multiple schedule of repeated learning and performance in female rats subjected to lifetime Pb exposure (0 or 50 ppm Pb in drinking water beginning in dams 2 months prior to breeding; blood Pb levels ∼10 μg/dl), to prenatal restraint stress on gestational days 16 and 17, or to both. Blood Pb, corticosterone levels, brain monoamines, and hippocampal nerve growth factor levels were also measured. Sequence-specific learning deficits produced by Pb, particularly the number of responses to correctly learn response sequences, were further enhanced by stress, whereas performance measures were unimpaired. Statistical analyses indicated significant relationships among corticosterone levels, frontal cortex dopamine (DA), nucleus accumbens dopamine turnover, and total responses required to learn sequences. This study demonstrates that Pb and stress can act together to produce selective and highly condition-dependent deficits in learning in female rats that may be related to glucocorticoid-mediated interactions with mesocorticolimbic regions of brain. These findings also underscore the critical need to evaluate toxicants in the context of other risk factors pertinent to human diseases and disorders.

  2. Evidence against a critical role of CB1 receptors in adaptation of the hypothalamic-pituitary-adrenal axis and other consequences of daily repeated stress.

    Science.gov (United States)

    Rabasa, Cristina; Pastor-Ciurana, Jordi; Delgado-Morales, Raúl; Gómez-Román, Almudena; Carrasco, Javier; Gagliano, Humberto; García-Gutiérrez, María S; Manzanares, Jorge; Armario, Antonio

    2015-08-01

    There is evidence that endogenous cannabinoids (eCBs) play a role in the control of the hypothalamic-pituitary-adrenal (HPA) axis, although they appear to have dual, stimulatory and inhibitory, effects. Recent data in rats suggest that eCBs, acting through CB1 receptors (CB1R), may be involved in adaptation of the HPA axis to daily repeated stress. In the present study we analyze this issue in male mice and rats. Using a knock-out mice for the CB1 receptor (CB1-/-) we showed that mutant mice presented similar adrenocorticotropic hormone (ACTH) response to the first IMO as wild-type mice. Daily repeated exposure to 1h of immobilization reduced the ACTH response to the stressor, regardless of the genotype, demonstrating that adaptation occurred to the same extent in absence of CB1R. Prototypical changes observed after repeated stress such as enhanced corticotropin releasing factor (CRH) gene expression in the paraventricular nucleus of the hypothalamus, impaired body weight gain and reduced thymus weight were similarly observed in both genotypes. The lack of effect of CB1R in the expression of HPA adaptation to another similar stressor (restraint) was confirmed in wild-type CD1 mice by the lack of effect of the CB1R antagonist AM251 just before the last exposure to stress. Finally, the latter drug did not blunt the HPA, glucose and behavioral adaptation to daily repeated forced swim in rats. Thus, the present results indicate that CB1R is not critical for overall effects of daily repeated stress or proper adaptation of the HPA axis in mice and rats.

  3. 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.

  4. Ventral tegmental area dopamine revisited: effects of acute and repeated stress.

    Science.gov (United States)

    Holly, Elizabeth N; Miczek, Klaus A

    2016-01-01

    Aversive events rapidly and potently excite certain dopamine neurons in the ventral tegmental area (VTA), promoting phasic increases in the medial prefrontal cortex and nucleus accumbens. This is in apparent contradiction to a wealth of literature demonstrating that most VTA dopamine neurons are strongly activated by reward and reward-predictive cues while inhibited by aversive stimuli. How can these divergent processes both be mediated by VTA dopamine neurons? The answer may lie within the functional and anatomical heterogeneity of the VTA. We focus on VTA heterogeneity in anatomy, neurochemistry, electrophysiology, and afferent/efferent connectivity. Second, recent evidence for a critical role of VTA dopamine neurons in response to both acute and repeated stress will be discussed. Understanding which dopamine neurons are activated by stress, the neural mechanisms driving the activation, and where these neurons project will provide valuable insight into how stress can promote psychiatric disorders associated with the dopamine system, such as addiction and depression.

  5. Increases in fruit intakes in older low consumers of fruit following two community-based repeated exposure interventions.

    Science.gov (United States)

    Appleton, K M

    2013-03-14

    The present study investigated the value of two repeated exposure interventions for increasing intakes of fruit in older people. A total of ninety-five participants (aged 65 years and over) were randomised to receive either one (E1), five (E5) or five plus (E5+) exposures to fruit over a 5-week period. Fruit exposures occurred in community-based church and social groups, through fruit-tasting sessions involving familiar fruits and novel fruit products and dishes (E1, E5, E5+), and through fruit provision (E5+). Daily intakes of fruit and vegetables were assessed before and after all interventions. Liking for all fruits was also measured during repeated exposure (E5, E5+). In low consumers of fruit (one portion/d or less), fruit intakes increased significantly in the repeated exposure groups (E5, E5+) (t(30) = 5·79, Polder low consumers of fruit, although no benefits of additional fruit provision were found. Repeated exposure was also easy to implement, of low cost and enjoyable.

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

    Directory of Open Access Journals (Sweden)

    Philip Maseghe Mwachaka

    2016-01-01

    Full Text Available 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.

  7. 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.

  8. Repeated exposure of acidic beverages on esthetic restorative materials: An in-vitro surface microhardness study.

    Science.gov (United States)

    Xavier, Arun M; Sunny, Steffy M; Rai, Kavita; Hegde, Amitha M

    2016-07-01

    A manifold increase in the consumption of aerated beverages has witnessed a twin increase in tooth wear and raised demand for esthetic restorative materials. This study aimed to evaluate the surface microhardness changes of esthetic restorative materials following treatment with aerated beverages in an in-vitro situation. The initial surface microhardness of the restorative materials GC Fuji II LC, GC Fuji IX, Nano Glass ionomer, Resin and Nano composite was recorded. These materials were studied under 3 groups that included those exposed to the acidic beverages daily, weekly once in a month and those that had no exposures at all. The final surface microhardness of the materials was recorded following experimentation and was subjected to statistical comparisons. The restorative materials were compared for their surface microhardness changes following respective treatments using the T-test and One-way ANOVA analysis. Inter-comparisons between the groups showed statistical significance (pmaterials revealed surface microhardness loss; the maximum reduction noticed with the Nano glass ionomer cement tested (pmaterials markedly reduced upon repeated exposures with acidic beverages; the product with phosphoric acid producing the maximum surface microhardness loss. Restorative materials, acidic beverages, surface microhardness, resin composites, glass ionomers.

  9. 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.

  10. 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.

  11. Gene deficiency and pharmacological inhibition of soluble epoxide hydrolase confers resilience to repeated social defeat stress.

    Science.gov (United States)

    Ren, Qian; Ma, Min; Ishima, Tamaki; Morisseau, Christophe; Yang, Jun; Wagner, Karen M; Zhang, Ji-Chun; Yang, Chun; Yao, Wei; Dong, Chao; Han, Mei; Hammock, Bruce D; Hashimoto, Kenji

    2016-03-29

    Depression is a severe and chronic psychiatric disease, affecting 350 million subjects worldwide. Although multiple antidepressants have been used in the treatment of depressive symptoms, their beneficial effects are limited. The soluble epoxide hydrolase (sEH) plays a key role in the inflammation that is involved in depression. Thus, we examined here the role of sEH in depression. In both inflammation and social defeat stress models of depression, a potent sEH inhibitor, TPPU, displayed rapid antidepressant effects. Expression of sEH protein in the brain from chronically stressed (susceptible) mice was higher than of control mice. Furthermore, expression of sEH protein in postmortem brain samples of patients with psychiatric diseases, including depression, bipolar disorder, and schizophrenia, was higher than controls. This finding suggests that increased sEH levels might be involved in the pathogenesis of certain psychiatric diseases. In support of this hypothesis, pretreatment with TPPU prevented the onset of depression-like behaviors after inflammation or repeated social defeat stress. Moreover, sEH KO mice did not show depression-like behavior after repeated social defeat stress, suggesting stress resilience. The sEH KO mice showed increased brain-derived neurotrophic factor (BDNF) and phosphorylation of its receptor TrkB in the prefrontal cortex, hippocampus, but not nucleus accumbens, suggesting that increased BDNF-TrkB signaling in the prefrontal cortex and hippocampus confer stress resilience. All of these findings suggest that sEH plays a key role in the pathophysiology of depression, and that epoxy fatty acids, their mimics, as well as sEH inhibitors could be potential therapeutic or prophylactic drugs for depression.

  12. B-type natriuretic peptide (BNP serum levels in rats after forced repeated swimming stress

    Directory of Open Access Journals (Sweden)

    Almira Hadžovic-Džuvo

    2011-02-01

    Full Text Available Aim To estimate the effects of forced repeated swimming stress on BNP serum levels in rats. Methods Adult male Wistar rats weighting between 280-330 g were divided into two groups: control group (n =8 and stress group (n =8. Rats in the stress group were exposed to forced swimming stress daily, for 7 days. The rats were forced to swim in plastic tanks (90 cm wide, 120 cm deep containing tap water (temperature ca. 25°C. The depth of water was 40 cm. Duration of each swimming session progressively increased from 10 minutes on the irst day to 40 minutes on days 6 and 7. Rats were sacriiced and blood was drawn from abdominal aorta for BNP analysis immediately after the last swimming session. B-type natriuretic serum level was determined by ELISA method using RAT BNP-32 kit (Phoenix Pharmaceutical Inc.. Results There was no statistically signiicant difference between mean BNP serum level in the stress group after the swimming period (0.81±0.14 ng/ml as compared to the unstressed group of rats (0.8 ±0.08ng/ml. After the swimming period mean body weight slightly decreased in the stress group in comparison with values before stress period (296.3 g vs.272.8 g, but this difference was not statistically signiicant. The stress period had no inluence on food intake in the stress rat group. Conclusion The workload consisting of 40-minutes long swimming session is not suficient to provoke BNP release from myocardium in rats.

  13. Adulthood stress responses in rats are variably altered as a factor of adolescent stress exposure.

    Science.gov (United States)

    Moore, Nicole L T; Altman, Daniel E; Gauchan, Sangeeta; Genovese, Raymond F

    2016-05-01

    Stress exposure during development may influence adulthood stress response severity. The present study investigates persisting effects of two adolescent stressors upon adulthood response to predator exposure (PE). Rats were exposed to underwater trauma (UWT) or PE during adolescence, then to PE after reaching adulthood. Rats were then exposed to predator odor (PO) to test responses to predator cues alone. Behavioral and neuroendocrine assessments were conducted to determine acute effects of each stress experience. Adolescent stress altered behavioral response to adulthood PE. Acoustic startle response was blunted. Bidirectional changes in plus maze exploration were revealed as a factor of adolescent stress type. Neuroendocrine response magnitude did not predict severity of adolescent or adult stress response, suggesting that different adolescent stress events may differentially alter developmental outcomes regardless of acute behavioral or neuroendocrine response. We report that exposure to two different stressors in adolescence may differentially affect stress response outcomes in adulthood. Acute response to an adolescent stressor may not be consistent across all stressors or all dependent measures, and may not predict alterations in developmental outcomes pertaining to adulthood stress exposure. Further studies are needed to characterize factors underlying long-term effects of a developmental stressor.

  14. Characterization of the cognitive impairments induced by prenatal exposure to stress in the rat

    Directory of Open Access Journals (Sweden)

    Julie A. Markham

    2010-11-01

    Full Text Available We have previously shown that male rats exposed to gestational stress exhibit phenotypes resembling what is observed in schizophrenia, including hypersensitivity to amphetamine, blunted sensory gating, disrupted social behavior, impaired stress axis regulation, and aberrant prefrontal expression of genes involved in synaptic plasticity. Maternal psychological stress during pregnancy has been associated with adverse cognitive outcomes among children, as well as an increased risk for developing schizophrenia, which is characterized by significant cognitive deficits. We sought to characterize the long-term cognitive outcome of prenatal stress using a preclinical paradigm, which is readily amenable to the development of novel therapeutic strategies. Rats exposed to repeated variable prenatal stress during the third week of gestation were evaluated using a battery of cognitive tests, including the novel object recognition task, cued and contextual fear conditioning, the Morris water maze, and iterative versions of a paradigm in which working and reference memory for both objects and spatial locations can be assessed (the ‘Can Test’. Prenatally stressed males were impaired relative to controls on each of these tasks, confirming the face validity of this preclinical paradigm and extending the cognitive implications of prenatal stress exposure beyond the hippocampus. Interestingly, in experiments where both sexes were included, the performance of females was found to be less affected by prenatal stress compared to that of males. This could be related to the finding that women are less vulnerable than men to schizophrenia, and merits further investigation.

  15. Individual differences and repeatability in vocal production: stress-induced calling exposes a songbird's personality

    Science.gov (United States)

    Guillette, Lauren M.; Sturdy, Christopher B.

    2011-11-01

    Recent research in songbirds has demonstrated that male singing behavior varies systematically with personality traits such as exploration and risk taking. Here we examine whether the production of bird calls, in addition to bird songs, is repeatable and related to exploratory behavior, using the black-capped chickadee ( Poecile atricapillus) as a model. We assessed the exploratory behavior of individual birds in a novel environment task. We then recorded the vocalizations and accompanying motor behavior of both male and female chickadees, over the course of several days, in two different contexts: a control condition with no playback and a stressful condition where chick-a-dee mobbing calls were played to individual birds. We found that several vocalizations and behaviors were repeatable within both a control and a stressful context, and across contexts. While there was no relationship between vocal output and exploratory behavior in the control context, production of alarm and chick-a-dee calls in the stressful condition was positively associated with exploratory behavior. These findings are important because they show that bird calls, in addition to bird song, are an aspect of personality, in that calls are consistent both within and across contexts, and covary with other personality measures (exploration).

  16. Repeated psychosocial stress at night, but not day, affects the central molecular clock.

    Science.gov (United States)

    Bartlang, Manuela S; Savelyev, Sergey A; Johansson, Anne-Sofie; Reber, Stefan O; Helfrich-Förster, Charlotte; Lundkvist, Gabriella B S

    2014-11-01

    We have recently demonstrated that the outcome of repeated social defeat (SD) on behavior, physiology and immunology is more negative when applied during the dark/active phase as compared with the light/inactive phase of male C57BL/6 mice. Here, we investigated the effects of the same stress paradigm, which combines a psychosocial and novelty stressor, on the circadian clock in transgenic PERIOD2::LUCIFERASE (PER2::LUC) and wildtype (WT) mice by subjecting them to repeated SD, either in the early light phase (social defeat light = SDL) or in the early dark phase (social defeat dark = SDD) across 19 days. The PER2::LUC rhythms and clock gene mRNA expression were analyzed in the suprachiasmatic nucleus (SCN) and the adrenal gland, and PER2 protein expression in the SCN was assessed. SDD mice showed increased PER2::LUC rhythm amplitude in the SCN, reduced Per2 and Cryptochrome1 mRNA expression in the adrenal gland, and increased PER2 protein expression in the posterior part of the SCN compared with single-housed control (SHC) and SDL mice. In contrast, PER2::LUC rhythms in the SCN of SDL mice were not affected. However, SDL mice exhibited a 2-hour phase advance of the PER2::LUC rhythm in the adrenal gland compared to SHC mice. Furthermore, plasma levels of brain-derived neurotrophic factor (BDNF) and BDNF mRNA in the SCN were elevated in SDL mice. Taken together, these results show that the SCN molecular rhythmicity is affected by repeated SDD, but not SDL, while the adrenal peripheral clock is influenced mainly by SDL. The observed increase in BDNF in the SDL group may act to protect against the negative consequences of repeated psychosocial stress.

  17. Harm expectancy violation during exposure therapy for posttraumatic stress disorder

    NARCIS (Netherlands)

    Kleine, R.A. de; Hendriks, L.; Becker, E.S.; Broekman, T.G.; Minnen, A. van

    2017-01-01

    Exposure therapy has proven efficacy in the treatment of posttraumatic stress disorder (PTSD). Emotional processing theory proposes that fear habituation is a central mechanism in symptom reduction, but the empirical evidence supporting this is mixed. Recently it has been proposed that violation of

  18. Trauma Exposure and Posttraumatic Stress Disorder in Delinquent Female Adolescents

    Science.gov (United States)

    Ariga, Michio; Uehara, Toru; Takeuchi, Kazuo; Ishige, Yoko; Nakano, Reiko; Mikuni, Masahiko

    2008-01-01

    Background: Although juveniles within the justice system have high psychiatric morbidity, few comprehensive investigations have shown posttraumatic stress disorder (PTSD) in female delinquents. Here, we aim to describe the nature and extent of PTSD and trauma exposure and to clarify the relationships among comorbidity and psychosocial factors in…

  19. Mild heat stress at a young age in Drosophila melanogaster leads to increased Hsp70 synthesis after stress exposure later in life

    Indian Academy of Sciences (India)

    Torsten Nygaard Kristensen; Jesper Givskov Sørensen; Volker Loeschcke

    2003-12-01

    In a number of animal species it has been shown that exposure to low levels of stress at a young age has a positive effect on stress resistance later in life, and on longevity. The positive effects have been attributed to the activation of defence/cleaning systems (heat shock proteins (Hsps), antioxidases, DNA repair) or to effects of a changed metabolic rate, or both. We investigated the effect of mild stress exposures early in life on Hsp70 synthesis after a harder stress exposure later in life in five isofemale lines of Drosophila melanogaster. Female flies were either exposed to repeated bouts of mild heat stress (3 h at 34°C) at a young age (days 2, 4 and 6 post-eclosion) or held under standard laboratory conditions. At 16 and 32 days of adult age, respectively, flies were exposed to a high temperature treatment known to induce Hsp70 in the investigated species (1 h at 37°ºC). Thereafter, the inducible Hsp70 levels were measured. Our data show a tendency towards increased Hsp70 synthesis with increased age for both ‘mild stress’ and ‘no stress’ flies. Moreover, the results show that flies exposed to mild stress at a young age synthesized more Hsp70 upon induction, compared to control flies, and that this difference was accentuated at 32 days compared to 16 days of age. Thus, bouts of mild heat stress at a young age impact on the physiological stress response system later in life. This may be caused by an increased ability to react to future stresses. Alternatively, the mild stress exposure at a young age may actually have caused cellular damages increasing the need for Hsp70 levels after stress exposure later in life. The importance of an Hsp70 upregulation (throughout life) in explaining the phenomenon of hormesis is discussed, together with alternative hypotheses, and suggestions for further studies.

  20. Variability in prefrontal hemodynamic response during exposure to repeated self-selected music excerpts, a near-infrared spectroscopy study.

    Directory of Open Access Journals (Sweden)

    Saba Moghimi

    Full Text Available Music-induced brain activity modulations in areas involved in emotion regulation may be useful in achieving therapeutic outcomes. Clinical applications of music may involve prolonged or repeated exposures to music. However, the variability of the observed brain activity patterns in repeated exposures to music is not well understood. We hypothesized that multiple exposures to the same music would elicit more consistent activity patterns than exposure to different music. In this study, the temporal and spatial variability of cerebral prefrontal hemodynamic response was investigated across multiple exposures to self-selected musical excerpts in 10 healthy adults. The hemodynamic changes were measured using prefrontal cortex near infrared spectroscopy and represented by instantaneous phase values. Based on spatial and temporal characteristics of these observed hemodynamic changes, we defined a consistency index to represent variability across these domains. The consistency index across repeated exposures to the same piece of music was compared to the consistency index corresponding to prefrontal activity from randomly matched non-identical musical excerpts. Consistency indexes were significantly different for identical versus non-identical musical excerpts when comparing a subset of repetitions. When all four exposures were compared, no significant difference was observed between the consistency indexes of randomly matched non-identical musical excerpts and the consistency index corresponding to repetitions of the same musical excerpts. This observation suggests the existence of only partial consistency between repeated exposures to the same musical excerpt, which may stem from the role of the prefrontal cortex in regulating other cognitive and emotional processes.

  1. Repeated exposure to odors induces affective habituation of perception and sniffing

    Directory of Open Access Journals (Sweden)

    Camille eFerdenzi

    2014-04-01

    Full Text Available Olfactory perception, and especially hedonic evaluation of odors, is highly flexible, but some mechanisms involved in this flexibility remain to be elucidated. In the present study we aimed at better understanding how repeated exposure to odors can affect their pleasantness. We tested the hypothesis of an affective habituation to the stimuli, namely a decrease of emotional intensity over repetitions. More specifically, we tested whether this effect is subject to inter-individual variability and whether it can also be observed at the olfactomotor level. Twenty-six participants took part in the experiment during which they had to smell two odorants, anise and chocolate, presented twenty times each. On each trial, sniff duration and volume were recorded and paired with ratings of odor pleasantness and intensity. For each smell, we distinguished between likers and dislikers, namely individuals giving positive and negative initial hedonic evaluations. Results showed a significant decrease in pleasantness with time when the odor was initially pleasant (likers, while unpleasantness remained stable or slightly decreased when the odor was initially unpleasant (dislikers. This deviation towards neutrality was interpreted as affective habituation. This effect was all the more robust as it was observed for both odors and corroborated by sniffing, an objective measurement of odor pleasantness. Affective habituation to odors can be interpreted as an adaptive response to stimuli that prove over time to be devoid of positive or negative outcome on the organism. This study contributes to a better understanding of how olfactory preferences are shaped through exposure, depending on the individual’s own initial perception of the odor.

  2. Effects of repeated psychological stress training on the spectrum of serum protein expression in special troops

    Directory of Open Access Journals (Sweden)

    Li ZHANG

    2011-10-01

    Full Text Available Objective To investigate the effects of repeated psychological stress training on the serum protein expression in soldiers under mental stress.Methods Ninety-six male commando soldiers were randomly assigned into the common psychological training group,the circulation psychological training group and the control group(32 each.After a 4-week training,all the soldiers were instructed to attend an one-day high-intensity simulated anti-riot exercise,and 3 days later attended another unannounced high-intensity simulated anti-riot exercise.Blood samples were collected from all the soldiers within 4 hours after each exercise,and the changes in serum protein expression were determined and statistically analyzed by using surface-enhanced laser desorption/ionization time of flight mass spectrometry(SELDI-TOF-MS combined with ProteinChip technology.Results The variance analysis showed that significant differences existed among the three groups(P < 0.05 in the relative contents of proteins with M/Z values of 6417.8,9134.2,15171.9 and 14972.7D after the first anti-riot exercise,and the relative contents of all the above mentioned proteins increased in the circulatory psychological training group;meanwhile,markedly increasing trends of the relative contents of all the proteins were observed in the three groups after the second anti-riot exercise(P < 0.05,and in control group the relative contents of the 4 above mentioned proteins were significantly higher than those after the first anti-riot exercise.Conclusion Psychological training may up-regulate the expression of serum proteins that are down-regulated after stress,and the repeated high-intensity mental training can rapidly improve the soldiers’ ability to counteract stress.

  3. Synaptic Impairment in Layer 1 of the Prefrontal Cortex Induced by Repeated Stress During Adolescence is Reversed in Adulthood

    Science.gov (United States)

    Negrón-Oyarzo, Ignacio; Dagnino-Subiabre, Alexies; Muñoz Carvajal, Pablo

    2015-01-01

    Chronic stress is a risk factor for the development of psychiatric disorders, some of which involve dysfunction of the prefrontal cortex (PFC). There is a higher prevalence of these chronic stress-related psychiatric disorders during adolescence, when the PFC has not yet fully matured. In the present work we studied the effect of repeated stress during adolescence on synaptic function in the PFC in adolescence and adulthood. To this end, adolescent Sprague-Dawley rats were subjected to seven consecutive days of restraint stress. Afterward, both synaptic transmission and short- and long-term synaptic plasticity were evaluated in layer 1 of medial-PFC (mPFC) slices from adolescent and adult rats. We found that repeated stress significantly reduced the amplitude of evoked field excitatory post-synaptic potential (fEPSP) in the mPFC. Isolation of excitatory transmission reveled that lower-amplitude fEPSPs were associated with a reduction in α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor-mediated transmission. We also found that repeated stress significantly decreased long-term depression (LTD). Interestingly, AMPA/kainate receptor-mediated transmission and LTD were recovered in adult animals that experienced a three-week stress-free recovery period. The data indicates that the changes in synaptic transmission and plasticity in the mPFC induced by repeated stress during adolescence are reversed in adulthood after a stress-free period. PMID:26617490

  4. 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 juic...

  5. 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...

  6. Effect of repeated and prolonged exposure to low concentrations of Low Molecular Weight chemicals on local lymph node responses

    NARCIS (Netherlands)

    Jong WH de; Beek M ter; Veenman C; Klerk A de; Loveren H van; TOX

    2006-01-01

    The results of the local lymph node assay are not for all compounds useful as starting point for a quantitative risk assessment. This study describes the effects after repeated exposure of the skin to a concentration of a sensitizer below the threshold used in the local lymph node assay. Positive re

  7. Effects of hemin and thermal stress exposure on JWA expression

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ming; CHEN Rui; LI Aiping; ZHOU Jianwei

    2007-01-01

    To investigate the expression of JWA after hemin and (or) thermal stress exposure,we treated K562 (chronic myelogenous leukemia cells) cells with different doses of hemin and thermal stress using different exposure times.The expression of JWA protein was determined by Western blot analysis.Reverse transcription-polymerase chain reaction was carried out to determine JWA mRNA expression.JWA promoter transcription activity analysis was performed by chloramphenicol acetyl transferase-enzyme linked immunosorbent assay (CAT-ELISA).The expression of JWA protein was significantly increased by up to (3.23 +0.57) folds compared to the control in K562 cells after hemin treatment (50 μM for one week),and a similar pattern was observed in the cells after treatment with thermal stress (42℃) for 2 hours [increased by (8.00+ 1.73) folds].The expression of JWA mRNA was also significantly elevated by up to (1.37 + 0.06)folds in K562 cells treated with hemin (30 μM for 48 hours),and a similar regulatory pattern [increased by (1.87±0.13)folds] was observed with thermal stress exposure (42℃) for 30 minutes.However,a combined antagonistic effect was observed in the treatment of K562 cells with hemin (30 μM,48 h) followed by thermal stress (42℃,30 min).CAT-ELISA further confirmed that either hemin or thermal stress treatment could up-regulate JWA transcription activity,however,the effects could be counteracted partly by treatment with a combination of both.Hemin and thermal stress might regulate JWA expression via distinct intracellular signal transduction pathways.

  8. Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

    Energy Technology Data Exchange (ETDEWEB)

    Zago, A. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Leão, R.M.; Carneiro-de-Oliveira, P.E. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Programa Interinstitucional de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de São Carlos/Universidade Estadual de São Paulo, Araraquara, SP (Brazil); Marin, M.T.; Cruz, F.C. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Planeta, C.S. [Laboratório de Farmacologia, Faculdade de Ciências Farmacêuticas, Universidade Estadual Paulista, Araraquara, SP (Brazil); Programa Interinstitucional de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de São Carlos/Universidade Estadual de São Paulo, Araraquara, SP (Brazil)

    2011-11-18

    Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although crosssensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P) 28-37) and adult (P60-67) rats received nicotine (0.4 mg/kg, sc) or saline (0.9% NaCl, sc) and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc) or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.

  9. GT-repeat polymorphism in the heme oxygenase-1 gene promoter and the risk of carotid atherosclerosis related to arsenic exposure

    Directory of Open Access Journals (Sweden)

    Wu Meei-Maan

    2010-08-01

    Full Text Available Abstract Background Arsenic is a strong stimulus of heme oxygenase (HO-1 expression in experimental studies in response to oxidative stress caused by a stimulus. A functional GT-repeat polymorphism in the HO-1 gene promoter was inversely correlated to the development of coronary artery disease in diabetics and development of restenosis following angioplasty in patients. The role of this potential vascular protective factor in carotid atherosclerosis remains unclear. We previously reported a graded association of arsenic exposure in drinking water with an increased risk of carotid atherosclerosis. In this study, we investigated the relationship between HO-1 genetic polymorphism and the risk of atherosclerosis related to arsenic. Methods Three-hundred and sixty-seven participants with an indication of carotid atherosclerosis and an additional 420 participants without the indication, which served as the controls, from two arsenic exposure areas in Taiwan, a low arsenic-exposed Lanyang cohort and a high arsenic-exposed LMN cohort, were studied. Carotid atherosclerosis was evaluated using a duplex ultrasonographic assessment of the extracranial carotid arteries. Allelic variants of (GTn repeats in the 5'-flanking region of the HO-1 gene were identified and grouped into a short (S allele ( Results Analysis results showed that arsenic's effect on carotid atherosclerosis differed between carriers of the class S allele (OR 1.39; 95% CI 0.86-2.25; p = 0.181 and non-carriers (OR 2.65; 95% CI 1.03-6.82; p = 0.044 in the high-exposure LMN cohort. At arsenic exposure levels exceeding 750 μg/L, difference in OR estimates between class S allele carriers and non-carriers was borderline significant (p = 0.051. In contrast, no such results were found in the low-exposure Lanyang cohort. Conclusions This exploratory study suggests that at a relatively high level of arsenic exposure, carriers of the short (GTn allele (

  10. Measuring lifetime stress exposure and protective factors in life course research on racial inequality and birth outcomes.

    Science.gov (United States)

    Malat, Jennifer; Jacquez, Farrah; Slavich, George M

    2017-07-01

    There has been a long-standing interest in better understanding how social factors contribute to racial disparities in health, including birth outcomes. A recent emphasis in this context has been on identifying the effects of stress exposure and protective factors experienced over the entire lifetime. Yet despite repeated calls for a life course approach to research on this topic, very few studies have actually assessed how stressors and protective factors occurring over women's lives relate to birth outcomes. We discuss this issue here by describing how challenges in the measurement of lifetime stress exposure and protective factors have prevented researchers from developing an empirically-based life course perspective on health. First, we summarize prevailing views on racial inequality and birth outcomes; second, we discuss measurement challenges that exist in this context; and finally, we describe both new tools and needed tools for assessing lifetime stress exposure and suggest opportunities for integrating information on stress exposure and psychosocial protective factors. We conclude that more studies are needed that integrate information about lifetime stress exposures and the protective factors that promote resilience against such exposures to inform policy and practice recommendations to reduce racial disparities in birth outcomes.

  11. Repeated stress-induced stimulation of catecholamine response is not followed by altered immune cell redistribution.

    Science.gov (United States)

    Imrich, Richard; Tibenska, Elena; Koska, Juraj; Ksinantova, Lucia; Kvetnansky, Richard; Bergendiova-Sedlackova, Katarina; Blazicek, Pavol; Vigas, Milan

    2004-06-01

    Stress response is considered an important factor in the modulation of immune function. Neuroendocrine hormones, including catecholamines, affect the process of immune cell redistribution, important for cell-mediated immunity. This longitudinal investigation was aimed at evaluating the effect of repeated stress-induced elevation of catecholamines on immune cell redistribution and expression of adhesive molecules. We assessed the responses of epinephrine (EPI), norepinephrine (NE), cortisol, changes in lymphocytes subpopulations, and percentages of CD11a+, CD11b+, and CD62L+ lymphocytes to a 20-min treadmill exercise of an intensity equal to 80% of the individual's Vo(2)max. The exercise was performed before and after 6 weeks of endurance training consisting of a 1-h run 4 times a week (ET) and after 5 days of bed rest (HDBR) in 10 healthy males. We did not observe any significant changes in the basal levels of EPI, NE, and cortisol in the plasma, nor in the immune parameters after ET and HDBR. The exercise test led to a significant (P <.001) elevation of EPI and NE levels after both ET and HDBR, a significant elevation (P <.01) of cortisol after HDBR, an increase in the absolute numbers of leukocytes, granulocytes, monocytes, CD3+, CD4+, CD8+, CD16+, CD19+ lymphocytes, percentage of CD11a+ and CD11b+ lymphocytes, and to a decrease of CD62L1 before, after ET, and after HDBR. We found comparable changes in all measured immune parameters after ET and HDBR. In conclusion, repeated stress-induced elevation of EPI and NE was not associated with an alteration in immune cell redistribution found in response to the single bout of exercise.

  12. Trauma exposure relates to heightened stress, altered amygdala morphology and deficient extinction learning: Implications for psychopathology.

    Science.gov (United States)

    Cacciaglia, Raffaele; Nees, Frauke; Grimm, Oliver; Ridder, Stephanie; Pohlack, Sebastian T; Diener, Slawomira J; Liebscher, Claudia; Flor, Herta

    2017-02-01

    Stress exposure causes a structural reorganization in neurons of the amygdala. In particular, animal models have repeatedly shown that both acute and chronic stress induce neuronal hypertrophy and volumetric increase in the lateral and basolateral nuclei of amygdala. These effects are visible on the behavioral level, where stress enhances anxiety behaviors and provokes greater fear learning. We assessed stress and anxiety levels in a group of 18 healthy human trauma-exposed individuals (TR group) compared to 18 non-exposed matched controls (HC group), and related these measurements to amygdala volume. Traumas included unexpected adverse experiences such as vehicle accidents or sudden loss of a loved one. As a measure of aversive learning, we implemented a cued fear conditioning paradigm. Additionally, to provide a biological marker of chronic stress, we measured the sensitivity of the hypothalamus-pituitary-adrenal (HPA) axis using a dexamethasone suppression test. Compared to the HC, the TR group showed significantly higher levels of chronic stress, current stress and trait anxiety, as well as increased volume of the left amygdala. Specifically, we observed a focal enlargement in its lateral portion, in line with previous animal data. Compared to HC, the TR group also showed enhanced late acquisition of conditioned fear and deficient extinction learning, as well as salivary cortisol hypo-suppression to dexamethasone. Left amygdala volumes positively correlated with suppressed morning salivary cortisol. Our results indicate differences in trauma-exposed individuals which resemble those previously reported in animals exposed to stress and in patients with post-traumatic stress disorder and depression. These data provide new insights into the mechanisms through which traumatic stress might prompt vulnerability for psychopathology.

  13. Impact of repeated stress on traumatic brain injury-induced mitochondrial electron transport chain expression and behavioral responses in rats

    Directory of Open Access Journals (Sweden)

    Guoqiang eXing

    2013-12-01

    Full Text Available A significant proportion of the military personnel returning from Iraq and Afghanistan conflicts have suffered from both mild traumatic brain injury (mTBI and post-traumatic stress disorder (PTSD. The mechanisms are unknown. We used a rat model of repeated stress and mTBI to examine brain activity and behavioral function. Adult male Sprague-Dawley rats were divided into 4 groups: Naïve; 3 days repeated tail-shock stress; lateral fluid percussion mTBI; and repeated stress followed by mTBI (S-mTBI. Open field activity, sensorimotor responses, and acoustic startle responses were measured after mTBI. The protein expression of mitochondrial electron transport chain (ETC complex subunits (CI-V and pyruvate dehydrogenase (PDHE1α1 were determined in 4 brain regions at day 7 post mTBI. Compared to Naïves, repeated stress decreased horizontal activity; repeated stress and mTBI both decreased vertical activity; and the mTBI and S-mTBI groups were impaired in sensorimotor and acoustic startle responses. Repeated stress significantly increased CI, CII, and CIII protein levels in the prefrontal cortex (PFC, but decreased PDHE1α1 protein in the PFC and cerebellum, and decreased CIV protein in the hippocampus. The mTBI treatment decreased CV protein levels in the ipsilateral hippocampus. The S-mTBI treatment resulted in increased CII, CIII, CIV, and CV protein levels in the PFC, increased CI level in the cerebellum, and increased CIII and CV levels in the cerebral cortex, but decreased CI, CII, CIV, and PDHE1α1 protein levels in the hippocampus. Thus, repeated stress or mTBI alone differentially altered ETC expression in heterogeneous brain regions. Repeated stress followed by mTBI had synergistic effects on brain ETC expression, and resulted in more severe behavioral deficits. These results suggest that repeated stress could have contributed to the high incidence of long-term neurologic and neuropsychiatric morbidity in military personnel with or without

  14. Possible stimulation of anti-tumor immunity using repeated cold stress: a hypothesis

    Directory of Open Access Journals (Sweden)

    Radoja Sasa

    2007-11-01

    Full Text Available Abstract Background The phenomenon of hormesis, whereby small amounts of seemingly harmful or stressful agents can be beneficial for the health and lifespan of laboratory animals has been reported in literature. In particular, there is accumulating evidence that daily brief cold stress can increase both numbers and activity of peripheral cytotoxic T lymphocytes and natural killer cells, the major effectors of adaptive and innate tumor immunity, respectively. This type of regimen (for 8 days has been shown to improve survival of mice infected with intracellular parasite Toxoplasma gondii, which would also be consistent with enhanced cell-mediated immunity. Presentation of the hypothesis This paper hypothesizes that brief cold-water stress repeated daily over many months could enhance anti-tumor immunity and improve survival rate of a non-lymphoid cancer. The possible mechanism of the non-specific stimulation of cellular immunity by repeated cold stress appears to involve transient activation of the sympathetic nervous system, hypothalamic-pituitary-adrenal and hypothalamic-pituitary-thyroid axes, as described in more detail in the text. Daily moderate cold hydrotherapy is known to reduce pain and does not appear to have noticeable adverse effects on normal test subjects, although some studies have shown that it can cause transient arrhythmias in patients with heart problems and can also inhibit humoral immunity. Sudden immersion in ice-cold water can cause transient pulmonary edema and increase permeability of the blood-brain barrier, thereby increasing mortality of neurovirulent infections. Testing the hypothesis The proposed procedure is an adapted cold swim (5–7 minutes at 20 degrees Celsius, includes gradual adaptation to be tested on a mouse tumor model. Mortality, tumor size, and measurements of cellular immunity (numbers and activity of peripheral CD8+ T lymphocytes and natural killer cells of the cold-exposed group would be compared to

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

    Institute of Scientific and Technical Information of China (English)

    Mustafa; Atas; Burhan; Baskan; Ayse; zkse; Fatma; Mutlu; Sarιgüzel; Süleyman; Demircan; Emine; Pangal

    2014-01-01

    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 linezolid

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

    Science.gov (United States)

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

    2004-01-01

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

  17. Change in tensile properties of neoprene and nitrile gloves after repeated exposures to acetone and thermal decontamination.

    Science.gov (United States)

    Gao, Pengfei; Tomasovic, Beth

    2005-11-01

    This study investigated the change in tensile properties of neoprene and nitrile gloves after repeated cycles of exposure to acetone, followed by thermal decontamination. The glove was exposed to acetone (outer surface in contact with chemical), subjected to thermal decontamination, and tested for the tensile strength and the ultimate elongation. Thermal decontamination was carried out inside an oven for 16 hours at 100 degrees C. The exposure/decontamination procedure was repeated for a maximum of 10 cycles. For neoprene versus acetone, the mean tensile strength consistently decreased after each exposure/decontamination cycle. Multiple comparisons indicated that the mean tensile strengths between the new swatches and each exposure/decontamination group were significantly different (p 0.05). The mean tensile strength for the new swatches was 37.1 MPa and the mean tensile strength after nine exposure/decontamination cycles was 36.0 MPa, with a loss less than 3%. The largest single cycle loss for ultimate elongation occurred during the first exposure/decontamination cycle for both glove materials. In our previous study, decisions regarding the effectiveness of the decontamination process were based on having no discernible change in the breakthrough time and steady-state permeation rate. The results of this study indicate that the effectiveness of the decontamination process cannot be based on permeation parameters alone but must also take into account the change in physical properties.

  18. 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...... and morphology) and DNA fragmentation index (DFI) were determined. CAG and GGN repeat lengths were determined by direct sequencing of leukocyte DNA. RESULTS: A statistically significant interaction was found between the CB-153 group and CAG repeat category in relation to sperm concentration and total sperm count...

  19. 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 < 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. PMID:28127418

  20. 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.

  1. Changes on expected taste perception of probiotic and conventional yogurts made from goat milk after rapidly repeated exposure.

    Science.gov (United States)

    Costa, M P; Balthazar, C F; Franco, R M; Mársico, E T; Cruz, A G; Conte, C A

    2014-05-01

    Goat milk yogurt is an excellent source of fatty acids, protein, and minerals; however, it is not well accepted by many consumers, due to its typical flavor derived from caprylic, capric, and caproic acids present in this milk and dairy products. Recently, the repeated-exposure test has been used to increase the consumption of particular foods. This methodology has been used to increase children's willingness to eat food in some settings and has also been used to reduce sodium in soup. Based on these considerations, the aim of this study was to investigate whether repeated exposures may increase acceptance of both goat milk yogurt and probiotic goat milk yogurt. In a pre-exposure session, a total of 45 panelists (28 females and 17 males) from southeastern Brazil, who were not used to consuming dairy goat milk, evaluated the expected taste perception and the perceived liking after tasting 3 yogurt preparations. Then, consumers were randomly divided into 3 groups and participated in rapidly repeated exposure sessions performed within 6 d. Each panelist consumed only the yogurt that he or she would be exposed to. The day after the exposure sessions, all panelists returned to participate in the postexposure session and were asked to evaluate acceptance, familiarity, and the "goaty taste" characteristic of each yogurt. Regarding the expected liking before tasting, results showed higher expectations for cow milk yogurt compared with goat milk yogurt, which proved that consumers were not familiar with the goat milk yogurt. Likewise, only cow milk yogurt presented high acceptance and familiarity rates, confirming that these panelists were used to consuming cow milk products. With respect to the rapidly repeated exposure, 6 d were enough to significantly increase the consumers' familiarity with goat milk yogurt and probiotic goat milk yogurt. However, this method was not suitable to significantly increase the acceptance of such products. Nonetheless, a correlation existed

  2. Reaction of chickens to graduated length of exposure to stress

    Science.gov (United States)

    Nvota, J.; Grom, A.; Faberova, A.

    1980-01-01

    The reactions of 60 day old chickens Arbor Acres 60 X Vantress to immobilization stress lasting 1/2, 1, 2, 4 hours and to application of ACTH, manifested by activity changes in the systems hypophysis-adrenal gland and hypophysis-thyroid gland were studied. The highest activity increase in the two neuro-endocrine systems of the chickens was found to occur after 1/2 hour exposure to stress. With prolonged stress the responses weakened and after 4 hours most of the values gradually regressed to their initial level. The responses of both systems were synchronized. Reactions of the chickens differed from those of laboratory rats in which an increased activity of the hypophysis-adrenal gland system coincided with attenuation of the hypophysis-thyroid gland system.

  3. DNA repair and cell cycle biomarkers of radiation exposure and inflammation stress in human blood.

    Directory of Open Access Journals (Sweden)

    Helen Budworth

    Full Text Available DNA damage and repair are hallmarks of cellular responses to ionizing radiation. We hypothesized that monitoring the expression of DNA repair-associated genes would enhance the detection of individuals exposed to radiation versus other forms of physiological stress. We employed the human blood ex vivo radiation model to investigate the expression responses of DNA repair genes in repeated blood samples from healthy, non-smoking men and women exposed to 2 Gy of X-rays in the context of inflammation stress mimicked by the bacterial endotoxin lipopolysaccharide (LPS. Radiation exposure significantly modulated the transcript expression of 12 genes of 40 tested (2.2E-06exposure, and LPS co-treatment significantly affected their radiation responses. At the protein level, BAX and pCHK2-thr68 were elevated after radiation exposure, but the pCHK2-thr68 response was significantly decreased in the presence of LPS. Our combined panel yields an estimated 4-group accuracy of ∼90% to discriminate between radiation alone, inflammation alone, or combined exposures. Our findings suggest that DNA repair gene expression may be helpful to identify biodosimeters of exposure to radiation, especially within high-complexity exposure scenarios.

  4. Dynamic damage and stress-strain relations of ultra-high performance cementitious composites subjected to repeated impact

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Ultra-high performance cementitious composites (UHPCC) were prepared by replacing 60% of cement with ultra-fine industrial waste powders.The dynamic damage and compressive stress-strain relations of UHPCC were studied using split Hopkinson pressure bar (SHPB).The damage of UHPCC subjected to repeated impact was measured by the ultrasonic pulse velocity method.Results show that the dynamic damage of UHPCC increases linearly with impact times and the abilities of repeated impact resistance of UHPCC are improved with increasing fiber volume fraction.The stress waves on impact were recorded and the average stress,strain and strain rate of UHPCC were calculated based on the wave propagation theory.The effects of strain rate,fibers volume fraction and impact times on the stress-strain relations of UHPCC were studied.Results show that the peak stress and elastic modulus decrease while the strain rate and peak strain increase gradually with increasing impact times.

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

    OpenAIRE

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

    2014-01-01

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

  6. Inhibition of Voltage-Gated Calcium Channels After Subchronic and Repeated Exposure of PC12 Cells to Different Classes of Insecticides.

    Science.gov (United States)

    Meijer, Marieke; Brandsema, Joske A R; Nieuwenhuis, Desirée; Wijnolts, Fiona M J; Dingemans, Milou M L; Westerink, Remco H S

    2015-10-01

    We previously demonstrated that acute inhibition of voltage-gated calcium channels (VGCCs) is a common mode of action for (sub)micromolar concentrations of chemicals, including insecticides. However, because human exposure to chemicals is usually chronic and repeated, we investigated if selected insecticides from different chemical classes (organochlorines, organophosphates, pyrethroids, carbamates, and neonicotinoids) also disturb calcium homeostasis after subchronic (24 h) exposure and after a subsequent (repeated) acute exposure. Effects on calcium homeostasis were investigated with single-cell fluorescence (Fura-2) imaging of PC12 cells. Cells were depolarized with high-K(+) saline to study effects of subchronic or repeated exposure on VGCC-mediated Ca(2+) influx. The results demonstrate that except for carbaryl and imidacloprid, all selected insecticides inhibited depolarization (K(+))-evoked Ca(2+) influx after subchronic exposure (IC50's: approximately 1-10 µM) in PC12 cells. These inhibitory effects were not or only slowly reversible. Moreover, repeated exposure augmented the inhibition of the K(+)-evoked increase in intracellular calcium concentration induced by subchronic exposure to cypermethrin, chlorpyrifos, chlorpyrifos-oxon, and endosulfan (IC50's: approximately 0.1-4 µM). In rat primary cortical cultures, acute and repeated chlorpyrifos exposure also augmented inhibition of VGCCs compared with subchronic exposure. In conclusion, compared with subchronic exposure, repeated exposure increases the potency of insecticides to inhibit VGCCs. However, the potency of insecticides to inhibit VGCCs upon repeated exposure was comparable with the inhibition previously observed following acute exposure, with the exception of chlorpyrifos. The data suggest that an acute exposure paradigm is sufficient for screening chemicals for effects on VGCCs and that PC12 cells are a sensitive model for detection of effects on VGCCs. © The Author 2015. Published by Oxford

  7. Telomere dynamics may link stress exposure and ageing across generations.

    Science.gov (United States)

    Haussmann, Mark F; Heidinger, Britt J

    2015-11-01

    Although exposure to stressors is known to increase disease susceptibility and accelerate ageing, evidence is accumulating that these effects can span more than one generation. Stressors experienced by parents have been reported to negatively influence the longevity of their offspring and even grand offspring. The mechanisms underlying these long-term, cross-generational effects are still poorly understood, but we argue here that telomere dynamics are likely to play an important role. In this review, we begin by surveying the current connections between stress and telomere dynamics. We then lay out the evidence that exposure to stressors in the parental generation influences telomere dynamics in offspring and potentially subsequent generations. We focus on evidence in mammalian and avian studies and highlight several promising areas where our understanding is incomplete and future investigations are critically needed. Understanding the mechanisms that link stress exposure across generations requires interdisciplinary studies and is essential to both the biomedical community seeking to understand how early adversity impacts health span and evolutionary ecologists interested in how changing environmental conditions are likely to influence age-structured population dynamics.

  8. Mitochondrial tolerance to single and repeat exposure to simulated sunlight in human epidermal and dermal skin cells.

    Science.gov (United States)

    Kelly, J; Murphy, J E J

    2016-12-01

    Sunlight represents the primary threat to mitochondrial integrity in skin given the unique nature of the mitochondrial genome and its proximity to the electron transport chain. The accumulation of mitochondrial DNA (mtDNA) mutations is a key factor in many human pathologies and this is linked to key roles of mitochondrial function in terms of energy production and cell regulation. The main objective of this study was to evaluate solar radiation induced changes in mitochondrial integrity, function and dynamics in human skin cells using a Q-Sun solar simulator to deliver a close match to the intensity of summer sunlight. Spontaneously immortalised human skin epidermal keratinocytes (HaCaT) and Human Dermal Fibroblasts (HDFn) were divided into two groups. Group A were irradiated once and Group B twice 7days apart and evaluated using cell survival, viability and mitochondrial membrane potential (MMP) and mass at 1, 4 and 7days post one exposure for Group A and 1, 4, 7 and 14days post second exposure for Group B. Viability and survival of HaCaT and HDFn cells decreased after repeat exposure to Simulated Sunlight Irradiation (SSI) with no recovery. HDFn cells showed no loss in MMP after one or two exposures to SSI compared to HaCaT cells which showed a periodic loss of MMP after one exposure with a repeat exposure causing a dramatic decrease from which cells did not recover. Mitochondrial Mass in exposed HDFn cells was consistent with control after one or two exposures to SSI; however mitochondrial mass was significantly decreased in HaCaT cells. Data presented here suggests that mitochondria in epidermal cells are more sensitive to sunlight damage compared to mitochondria in dermal cells, despite their origin, confirming a skin layer specific sensitivity to sunlight, but not as expected. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Stress exposure and psychological stress responses are related to glucose concentrations during pregnancy.

    Science.gov (United States)

    Horsch, Antje; Kang, Ji Seon; Vial, Yvan; Ehlert, Ulrike; Borghini, Ayala; Marques-Vidal, Pedro; Jacobs, Ingo; Puder, Jardena J

    2016-09-01

    The role of stress in the development of gestational diabetes mellitus (GDM) has so far been neglected. We investigated the impact of stress exposure (pregnancy-related and pregnancy-unrelated major life events), psychological stress responses (perceived stress, subjective experience of stress, anxiety, depression, sleep), and physiological stress responses (salivary cortisol, plasma copeptin levels) on glucose concentrations during pregnancy. Cross-sectional study, including 203 pregnant women at the maternity department of a Swiss university hospital. All women underwent routine screening for GDM with a 75-g oral glucose-tolerance test at 24-30 weeks of gestation. Pregnancy-related and pregnancy-unrelated major life events, perceived stress, general psychological distress, anxiety, depression, and amount of sleep were assessed by validated self-report questionnaires. Cortisol was measured using fasting and bedtime saliva samples, and copeptin using fasting plasma. All data were collected before communication of the screening test results. Significant positive associations were found between the number of pregnancy-related major life events and fasting glucose, while there was no association with pregnancy-unrelated major life events. More anxiety and depressive symptoms, a higher general level of distress, and a shorter duration of sleep were related to fasting glucose, although the latter two were no longer significant when age and BMI were controlled for. However, physiological stress responses were not associated with glucose concentrations. When testing for unique associations with fasting glucose, more general distress and shorter duration of sleep independently accounted for higher fasting glucose levels. Finally, when comparing women with and without GDM, we found that women who subsequently received the diagnosis of GDM reported more pregnancy-related life events. Some indicators of stress exposure and psychological stress responses were associated with

  10. Infectious Disease risks associated with exposure to stressful environments

    Science.gov (United States)

    Meehan, Ichard T.; Smith, Morey; Sams, Clarence

    1993-01-01

    Multiple environmental factors asociated with space flight can increase the risk of infectious illness among crewmembers thereby adversely affecting crew health and mission success. Host defences can be impaired by multiple physiological and psychological stressors including: sleep deprivation, disrupted circadian rhythms, separation from family, perceived danger, radiation exposure, and possibly also by the direct and indirect effects of microgravity. Relevant human immunological data from isolated or stressful environments including spaceflight will be reviewed. Long-duration missions should include reliable hardware which supports sophisticated immunodiagnostic capabilities. Future advances in immunology and molecular biology will continue to provide therapeutic agents and biologic response modifiers which should effectively and selectively restore immune function which has been depressed by exposure to environmental stressors.

  11. 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.

  12. Repeated otilonium bromide administration prevents neurotransmitter changes in colon of rats underwent to wrap restraint stress.

    Science.gov (United States)

    Traini, Chiara; Evangelista, Stefano; Girod, Vincent; Faussone-Pellegrini, Maria Simonetta; Vannucchi, Maria Giuliana

    2017-04-01

    Otilonium bromide (OB) is a spasmolytic drug successfully used for the treatment of irritable bowel syndrome (IBS). Its efficacy has been attributed to the block of L- and T-type Ca(2+) channels and muscarinic and tachykinin receptors in the smooth muscle. Furthermore, in healthy rats, repeated OB administration modified neurotransmitter expression and function suggesting other mechanisms of action. On this basis, we investigated whether repeated OB treatment prevented the functional and neurochemical changes observed in the colon of rats underwent to wrap restrain stress (WRS) a psychosocial stressor considered suitable to reproduce the main IBS signs and symptoms. In control, WRS and OB/WRS rats functional parameters were measured in vivo and morphological investigations were done ex vivo in the colon. The results showed that OB counteracts most of the neurotransmitters changes caused by WRS. In particular, the drug prevents the decrease in SP-, NK1r-, nNOS-, VIP-, and S100β-immunoreactivity (IR) and the increase in CGRP-, and CRF1r-IR. On the contrary, OB does not affect the increase in CRF2r-IR neurons observed in WRS rats and does not interfere with the mild mucosal inflammation due to WRS. Finally, OB per se increases the Mr2 expression in the muscle wall and decreases the number of the myenteric ChAT-IR neurons. Functional findings show a significantly reduction in the number of spontaneous abdominal contraction in OB treated rats. The ability of OB to block L-type Ca(2+) channels, also expressed by enteric neurons, might represent a possible mechanism through which OB exerts its actions. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  13. 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

  14. 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

  15. Protective Effect of Repeatedly Preadministered Brazilian Propolis Ethanol Extract against Stress-Induced Gastric Mucosal Lesions in Rats

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    Tadashi Nakamura

    2014-01-01

    Full Text Available The present study was conducted to clarify the protective effect of Brazilian propolis ethanol extract (BPEE against stress-induced gastric mucosal lesions in rats. The protective effect of BPEE against gastric mucosal lesions in male Wistar rats exposed to water-immersion restraint stress (WIRS for 6 h was compared between its repeated preadministration (50 mg/kg/day, 7 days and its single preadministration (50 mg/kg. The repeated BPEE preadministration attenuated WIRS-induced gastric mucosal lesions and gastric mucosal oxidative stress more largely than the single BPEE preadministration. In addition, the repeated BPEE preadministration attenuated neutrophil infiltration in the gastric mucosa of rats exposed to WIRS. The protective effect of the repeated preadministration of BPEE against WIRS-induced gastric mucosal lesions was similar to that of a single preadministration of vitamin E (250 mg/kg in terms of the extent and manner of protection. From these findings, it is concluded that BPEE preadministered in a repeated manner protects against gastric mucosal lesions in rats exposed to WIRS more effectively than BPEE preadministered in a single manner possibly through its antioxidant and anti-inflammatory actions.

  16. Prediction of local irritant effects after repeated dermal and respiratory exposure to chemicals

    NARCIS (Netherlands)

    Rennen, M.A.J.; Nordheim, K.; Houben, G.F.; Heer, C. de

    2002-01-01

    Health risks resulting from occupational exposure to chemicals are controlled by the establishment of acceptable dermal and respiratory exposure levels. Due to a lack of route-specific toxicity data, acceptable levels are frequently established by means of route-to-route extrapolation. A pitfall in

  17. Prediction of local irritant effects after repeated dermal and respiratory exposure to chemicals

    NARCIS (Netherlands)

    Rennen, M.A.J.; Nordheim, K.; Houben, G.F.; Heer, C. de

    2002-01-01

    Health risks resulting from occupational exposure to chemicals are controlled by the establishment of acceptable dermal and respiratory exposure levels. Due to a lack of route-specific toxicity data, acceptable levels are frequently established by means of route-to-route extrapolation. A pitfall in

  18. NEUROBEHAVIORAL EFFECTS OF CHRONIC DIETARY AND REPEATED HIGH-LEVEL SPIKE EXPOSURE TO CHLORPYRIFOS IN RATS.

    Science.gov (United States)

    This study aimed to model long-term subtoxic human exposure to an organophosphorus pesticide, chlorpyrifos, and to examine the influence of that exposure on the response to intermittent high-dose acute challenges. Adult rats were maintained on a chlorpyrifos-containing diet to p...

  19. Repeated measures of urinary oxidative stress biomarkers during pregnancy and preterm birth.

    Science.gov (United States)

    Ferguson, Kelly K; McElrath, Thomas F; Chen, Yin-Hsiu; Loch-Caruso, Rita; Mukherjee, Bhramar; Meeker, John D

    2015-02-01

    The purpose of this study was to investigate oxidative stress as a mechanism of preterm birth in human subjects; we examined associations between urinary biomarkers of oxidative stress that were measured at multiple time points during pregnancy and preterm birth. This nested case-control study included 130 mothers who delivered preterm and 352 mothers who delivered term who were originally recruited as part of an ongoing prospective birth cohort at Brigham and Women's Hospital. Two biomarkers that included 8-hydroxydeoxyguanosine (8-OHdG) and 8-isoprostane were measured in urine samples that were collected at up to 4 time points (median 10, 18, 26, and 35 weeks) during gestation. Urinary concentrations of 8-isoprostane and 8-OHdG decreased and increased, respectively, as pregnancy progressed. Average levels of 8-isoprostane across pregnancy were associated with increased odds of spontaneous preterm birth (adjusted odds ratio, 6.25; 95% confidence interval, 2.86-13.7), and associations were strongest with levels measured later in pregnancy. Average levels of 8-OHdG were protective against overall preterm birth (adjusted odds ratio, 0.19; 95% confidence interval, 0.10-0.34), and there were no apparent differences in the protective effect in cases of spontaneous preterm birth compared with cases of placental origin. Odds ratios for overall preterm birth were more protective in association with urinary 8-OHdG concentrations that were measured early in pregnancy. Maternal oxidative stress may be an important contributor to preterm birth, regardless of subtype and timing of exposure during pregnancy. The 2 biomarkers that were measured in the present study had opposite associations with preterm birth; an improved understanding of what each represents may help to identify more precisely important mechanisms in the pathway to preterm birth. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Effect of Repeated Stress Treatments During the Follicular Phase and Early Pregnancy on Reproductive Performance of Gilts

    NARCIS (Netherlands)

    Soede, N.M.; Roelofs, J.B.; Verheijen, R.J.E.; Schouten, W.G.P.; Hazeleger, W.; Kemp, B.

    2007-01-01

    In pig husbandry, stress is being considered an important cause of impaired reproductive performance. Therefore, an experiment was performed to quantify effects of repeated stressors during the follicular phase and/or during early pregnancy on reproductive performance of gilts. Eighty-one cyclic

  1. 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.

  2. 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.

  3. Social disparities in children’s exposure to second hand smoke at home: a repeated cross-sectional survey

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    Pisinger Charlotta

    2012-09-01

    Full Text Available Abstract Background Exposure to second hand smoke (SHS is an important preventable cause of morbidity and mortality in children. We hypothesised that there has been a growth in social inequality in children’s exposure to SHS at home over time. The purpose of this study was to investigate temporal change in smoking in homes including children, focusing on the socioeconomic differences. Methods Data is from a repeated cross-sectional survey, ‘Health Profiles of the Capital Region of Denmark’ conducted in 2007 and 2010, in 29 municipalities. The response rate was 52.3%, in both surveys. Our study included persons aged 25 to 64, living with children ≤15 years of age; N=9,289 in 2007 and 12,696 in 2010. Analyses were weighted for size of municipality and for non-response, which was higher among men and among persons who were younger, had a lower income, were living alone, were unemployed, and/or were of an ethnicity other than Danish. Regression analyses were used to investigate smoking in homes including children across parent/adult education levels, focusing on temporal changes. Results There were significant large socioeconomic differences in both 2007 and 2010. In 2010 it was more than 11 times more likely for a child to be exposed to SHS at home if the parent had very low education than if they were highly educated (p Conclusions Marked social inequalities in children’s exposure to SHS and a significant temporal decrease in exposure, independent of the education level of the parent/adult, were found in repeated large cross-sectional population-based studies. Social disparities have persisted over time, but not increased. Both clinical and population policy interventions will be needed in order to control child SHS exposure. We call for legislative protection of children from tobacco smoke inside their home as a supplement to parental education and support for smoking cessation.

  4. Low Lifetime Stress Exposure Is Associated with Reduced Stimulus-Response Memory

    Science.gov (United States)

    Goldfarb, Elizabeth V.; Shields, Grant S.; Daw, Nathaniel D.; Slavich, George M.; Phelps, Elizabeth A.

    2017-01-01

    Exposure to stress throughout life can cumulatively influence later health, even among young adults. The negative effects of high cumulative stress exposure are well-known, and a shift from episodic to stimulus-response memory has been proposed to underlie forms of psychopathology that are related to high lifetime stress. At the other extreme,…

  5. Repeated exposure to amphetamine during adolescence alters inhibitory tone in the medial prefrontal cortex following drug re-exposure in adulthood

    Science.gov (United States)

    Cox, Charles L.; Gulley, Joshua M.

    2016-01-01

    Behavioral sensitization following repeated amphetamine (AMPH) exposure is associated with changes in GABA function in the medial prefrontal cortex (mPFC). In rats exposed to AMPH during adolescence compared to adulthood, there are unique patterns of sensitization that may reflect age-dependent differences in drug effects on prefrontal GABAergic function. In the current study, we used a sensitizing regimen of repeated AMPH exposure in adolescent and adult rats to determine if a post-withdrawal AMPH challenge would alter inhibitory transmission in the mPFC in a manner that depends on age of exposure. Male Sprague-Dawley rats were treated with saline or 3 mg/kg AMPH (i.p.) during adolescence [postnatal day (P) 27 to P45] or adulthood (P85 to P103) and were sacrificed either at similar ages in adulthood (~P133; Experiment 1) or after similar withdrawal times (3-4 weeks; Experiment 2). Spontaneous inhibitory postsynaptic currents (sIPSCs) were recorded in vitro from deep layer pyramidal cells in the mPFC using the whole-cell configuration. We found no effect of AMPH pre-exposure on baseline sIPSC frequency. Subsequent application of AMPH (25 μM) produced a stable increase in sIPSC frequency in controls, suggesting that AMPH increases inhibitory tone in the mPFC. However, AMPH failed to increase sIPSCs in adolescent- or adult-exposed rats. In Experiment 2, where withdrawal period was kept similar for both exposure groups, AMPH induced a suppression of sIPSC activity in adolescent-exposed rats. These results suggest that sensitizing treatment with AMPH during adolescence or adulthood dampens inhibitory influences on mPFC pyramidal cells, but potentially through different mechanisms. PMID:27085589

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Changlian [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden); Department of Pediatrics, The Third Affiliated Hospital, Zhengzhou University (China); Gao, Jianfeng [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden); Department of Pediatrics, The Third Affiliated Hospital, Zhengzhou University (China); Department of Physiology, Henan Traditional Medical University (China); Li, Qian; Huang, Zhiheng; Zhang, Yu; Li, Hongfu [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden); Department of Pediatrics, The Third Affiliated Hospital, Zhengzhou University (China); Kuhn, Hans-Georg [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden); Blomgren, Klas, E-mail: klas.blomgren@neuro.gu.se [Center for Brain Repair and Rehabilitation, University of Gothenburg (Sweden); Department of Pediatric Oncology, The Queen Silvia Children' s Hospital, Gothenburg (Sweden)

    2011-01-07

    Research highlights: {yields} The effect of MRI on the developing brain is a matter of debate. {yields} Repeated exposure to MRI did not affect neurogenesis. {yields} Memory function was not affected by repeated MRI during development. {yields} Neither late gestation nor young postnatal brains were affected by MRI. {yields} 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 {sup 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.

  7. Effects of Repeated Ethanol Exposures on NMDA Receptor Expression and Locomotor Sensitization in Mice Expressing Ethanol Resistant NMDA Receptors

    Science.gov (United States)

    den Hartog, Carolina R.; Gilstrap, Meghin; Eaton, Bethany; Lench, Daniel H.; Mulholland, Patrick J.; Homanics, Gregg. E.; Woodward, John J.

    2017-01-01

    Evidence from a large number of preclinical studies suggests that chronic exposure to drugs of abuse, such as psychostimulants or ethanol induces changes in glutamatergic transmission in key brain areas associated with reward and control of behavior. These changes include alterations in the expression of ionotropic glutamate receptors including N-methyl-D-aspartate receptors (NMDAR) that are important for regulating neuronal activity and synaptic plasticity. NMDA receptors are inhibited by ethanol and reductions in NMDA-mediated signaling are thought to trigger homestatic responses that limit ethanol's effects on glutamatergic transmission. Following repeated exposures to ethanol, these homeostatic responses may become unstable leading to an altered glutamatergic state that contributes to the escalations in drinking and cognitive deficits observed in alcohol-dependent subjects. An important unanswered question is whether ethanol-induced changes in NMDAR expression are modulated by the intrinsic sensitivity of the receptor to ethanol. In this study, we examined the effects of ethanol on NMDAR subunit expression in cortical (orbitofrontal, medial prefrontal), striatal (dorsal and ventral striatum) and limbic (dorsal hippocampus, basolateral amygdala) areas in mice genetically modified to express ethanol-resistant receptors (F639A mice). These mice have been previously shown to drink more ethanol than their wild-type counterparts and have altered behavioral responses to certain actions of ethanol. Following long-term voluntary drinking, F639A mice showed elevations in GluN2A but not GluN1 or GluN2B expression as compared to wild-type mice. Mice treated with repeated injections with ethanol (2–3.5 g/kg; i.p.) showed changes in NMDAR expression that varied in a complex manner with genotype, brain region, subunit type and exposure protocol all contributing to the observed response. F639A mice, but not wild-type mice, showed enhanced motor activity following repeated

  8. Effects of simultaneous exposure to stress and nicotine on nicotine-induced locomotor activation in adolescent and adult rats

    Directory of Open Access Journals (Sweden)

    A. Zago

    2012-01-01

    Full Text Available Preclinical studies have shown that repeated stress experiences can result in an increase in the locomotor response to the subsequent administration of drugs of abuse, a phenomenon that has been termed behavioral cross-sensitization. Behavioral sensitization reflects neuroadaptive processes associated with drug addiction and drug-induced psychosis. Although cross-sensitization between stress- and drug-induced locomotor activity has been clearly demonstrated in adult rats, few studies have evaluated this phenomenon in adolescent rats. In the present study, we determined if the simultaneous exposure to stress and nicotine was capable of inducing behavioral sensitization to nicotine in adolescent and adult rats. To this end, adolescent (postnatal day (P 28-37 and adult (P60-67 rats received nicotine (0.4 mg/kg, sc or saline (0.9% NaCl, sc and were immediately subjected to restraint stress for 2 h once a day for 7 days. The control group for stress was undisturbed following nicotine or saline injections. Three days after the last exposure to stress and nicotine, rats were challenged with a single dose of nicotine (0.4 mg/kg, sc or saline and nicotine-induced locomotion was then recorded for 30 min. In adolescent rats, nicotine caused behavioral sensitization only in animals that were simultaneously exposed to stress, while in adult rats nicotine promoted sensitization independently of stress exposure. These findings demonstrate that adolescent rats are more vulnerable to the effects of stress on behavioral sensitization to nicotine than adult rats.

  9. 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

    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....... Two hours after the end of exposure the n-decane concentration decreased to about 25% in blood and 50% in brain. A similar pattern of elimination was also observed for n-nonane, n-undecane and total white spirit in blood and brain. In fat tissue the concentrations of n-nonane, n-decane, n......-undecane, and total white spirit increased during the 3 weeks of exposure. The time to reach steady-state concentrations is longer than 3 weeks. After the 3 weeks' exposure the fat tissue concentration of n-nonane, n-decane, n-undecane, and total white spirit decreased very slowly compared with the rate of decrease...

  10. Effects of Repeated Cocaine Exposure on Habit Learning and Reversal by N-Acetylcysteine

    Science.gov (United States)

    Corbit, Laura H; Chieng, Billy C; Balleine, Bernard W

    2014-01-01

    Exposure to drugs of abuse can result in a loss of control over both drug- and nondrug-related actions by accelerating the transition from goal-directed to habitual control, an effect argued to reflect changes in glutamate homeostasis. Here we examined whether exposure to cocaine accelerates habit learning and used in vitro electrophysiology to investigate its effects on measures of synaptic plasticity in the dorsomedial (DMS) and dorsolateral (DLS) striatum, areas critical for actions and habits, respectively. We then administered N-acetylcysteine (NAC) in an attempt to normalize glutamate homeostasis and hence reverse the cellular and behavioral effects of cocaine exposure. Rats received daily injections of cocaine (30 mg/kg) for 6 days and were then trained to lever press for a food reward. We used outcome devaluation and whole-cell patch-clamp electrophysiology to assess the behavioral and cellular effects of cocaine exposure. We then examined the ability of NAC to reverse the effects of cocaine exposure on these measures. Cocaine treatment produced a deficit in goal-directed action, as assessed by outcome devaluation, and increased the frequency of spontaneous and miniature excitatory postsynaptic currents (EPSCs) in the DMS but not in the DLS. Importantly, NAC treatment both normalized EPSC frequency and promoted goal-directed control in cocaine-treated rats. The promotion of goal-directed control has the potential to improve treatment outcomes in human cocaine addicts. PMID:24531561

  11. Metabolite profiles of rats in repeated dose toxicological studies after oral and inhalative exposure.

    Science.gov (United States)

    Fabian, E; Bordag, N; Herold, M; Kamp, H; Krennrich, G; Looser, R; Ma-Hock, L; Mellert, W; Montoya, G; Peter, E; Prokudin, A; Spitzer, M; Strauss, V; Walk, T; Zbranek, R; van Ravenzwaay, B

    2016-07-25

    The MetaMap(®)-Tox database contains plasma-metabolome and toxicity data of rats obtained from oral administration of 550 reference compounds following a standardized adapted OECD 407 protocol. Here, metabolic profiles for aniline (A), chloroform (CL), ethylbenzene (EB), 2-methoxyethanol (ME), N,N-dimethylformamide (DMF) and tetrahydrofurane (THF), dosed inhalatively for six hours/day, five days a week for 4 weeks were compared to oral dosing performed daily for 4 weeks. To investigate if the oral and inhalative metabolome would be comparable statistical analyses were performed. Best correlations for metabolome changes via both routes of exposure were observed for toxicants that induced profound metabolome changes. e.g. CL and ME. Liver and testes were correctly identified as target organs. In contrast, route of exposure dependent differences in metabolic profiles were noted for low profile strength e.g. female rats dosed inhalatively with A or THF. Taken together, the current investigations demonstrate that plasma metabolome changes are generally comparable for systemic effects after oral and inhalation exposure. Differences may result from kinetics and first pass effects. For compounds inducing only weak changes, the differences between both routes of exposure are visible in the metabolome.

  12. Effect of brief, repeated hyperbaric exposures on susceptibility to nitrogen narcosis.

    Science.gov (United States)

    Rogers, W H; Moeller, G

    1989-05-01

    We investigated the effect of brief, repetitive exposures to 5.5 ATA (148 fsw) in a hyperbaric chamber on adaptation to nitrogen narcosis. A standing-steadiness task, which measures body sway, was administered to 2 groups of 3 chamber-qualified men at 5.5 ATA and 1.3 ATA [10 fsw (control)] on each of 12 successive days to determine if an initial performance decrement at 5.5 ATA would be ameliorated with time. Standing steadiness was significantly worse at 5.5 ATA than at 1.3 ATA across all 12 exposures. There were also changes in standing steadiness from day to day, but these changes occurred in both the test and control depths. There was no day-x-depth interaction that would have indicated that the initial performance decrement at 5.5 ATA was reduced with repetitive exposures. These results are taken as evidence that there is little or no behavioral adaptation to nitrogen narcosis in response to brief, repetitive exposures to narcosis-inducing hyperbaric air.

  13. Single and repeated sevoflurane or desflurane exposure does not impair spatial memory performance of young adult mice.

    Science.gov (United States)

    Kilicaslan, Alper; Belviranli, Muaz; Okudan, Nilsel; Nurullahoglu Atalik, Esra

    2013-12-01

    Volatile anesthetics are known to disturb the spatial memory in aged rodents, but there is insufficient information on their effects on young adult rodents. The aim of this study was to compare the effects of single and repeated exposure to desflurane and sevoflurane on spatial learning and memory functions in young adult mice. Balb/c mice (2 months old) were randomly divided into six equal groups (n = 8). The groups with single inhalation were exposed to 3.3% sevoflurane or 7.8% desflurane or vehicle gas for 4 h, respectively. The groups with repeated inhalation were exposed to 3.3% sevoflurane or 7.8% desflurane or vehicle gas for 2 h a day during 5 consecutive days. Spatial learning and memory were tested in the Morris water maze 24 h after exposure. In the learning phase, the parameters associated with finding the hidden platform and swimming speed, and in the memory phase, time spent in the target quadrant and the adjacent quadrants, were assessed and compared between the groups. In the 4-day learning process, there was no significant difference between the groups in terms of mean latency to platform, mean distance traveled and average speed (P > 0.05). During the memory-test phase, all mice exhibited spatial memory, but there was no significant difference between the groups in terms of time spent in the target quadrant (P > 0.05). Sevoflurane and desflurane anesthesia did not impair acquisition learning and retention memory in young adult mice.

  14. Neonatal Repeated Exposure to Isoflurane not Sevoflurane in Mice Reversibly Impaired Spatial Cognition at Juvenile-Age.

    Science.gov (United States)

    Liu, Jianhui; Zhao, Yanhong; Yang, Junjun; Zhang, Xiaoqing; Zhang, Wei; Wang, Peijun

    2017-02-01

    Inhalation anesthetics facilitate surgical procedures in millions of children each year. However, animal studies demonstrate that exposure to the inhalation anesthetic isoflurane may cause neuronal cell death in developing brains. The long-term cytotoxic effects of sevoflurane, the most popular pediatric anesthetic, have not been compared with isoflurane. Thus, this study was designed to compare the effects of equipotent doses of these two anesthetics on neonatal long-term neurotoxicity. Postnatal 7-day-old (P7) C57/BL male mice were exposed to 1.5% isoflurane or 2.2% sevoflurane 2 h a day for 3 days. Non-anesthetized mice served as controls. The effects of anesthesia on learning and memory were assessed using the Morris Water Maze (MWM) at Postnatal days 30 (P30) and P60 respectively. The hippocampal content of N-methyl-D-aspartate receptor subunits (NMDA), brain-derived neurotrophic factor (BDNF), and synaptophysin (Syn) were determined by Western Blot. Neuron structure and apoptosis were assessed via Nissl and TUNEL staining, respectively. The isoflurane group exhibited cognitive impairment at P30. Repeated inhalation of isoflurane or sevoflurane caused different degrees of apoptosis and damaged hippocampal neurons in neonatal mice, particularly isoflurane. In neonatal mice, repeated exposure to isoflurane, but not sevoflurane, caused spatial cognitive impairments in juvenile mice. Our findings suggest that isoflurane induces significantly greater neurodegeneration than an equipotent minimum alveolar concentration of sevoflurane.

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

    Science.gov (United States)

    Palomino, Ana; Pavón, Francisco-Javier; Blanco-Calvo, Eduardo; Serrano, Antonia; Arrabal, Sergio; Rivera, Patricia; Alén, Francisco; Vargas, Antonio; Bilbao, Ainhoa; Rubio, Leticia; Rodríguez de Fonseca, Fernando; Suárez, Juan

    2014-01-01

    Growing awareness of cerebellar involvement in addiction is based on the cerebellum’s intermediary position between motor and reward, potentially acting as an interface between motivational and cognitive functions. Here, we examined the impact of acute and repeated cocaine exposure on the two main signaling systems in the mouse cerebellum: the endocannabinoid (eCB) and glutamate systems. To this end, we investigated whether eCB signaling-related gene and protein expression {cannabinoid receptor type 1 receptors and enzymes that produce [diacylglycerol lipase alpha/beta (DAGLα/β) and N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD)] and degrade [monoacylglycerol lipase (MAGL) and fatty acid amino hydrolase (FAAH)] eCB} were altered. In addition, we analyzed the gene expression of relevant components of the glutamate signaling system [glutamate synthesizing enzymes liver-type glutaminase isoform (LGA) and kidney-type glutaminase isoform (KGA), metabotropic glutamatergic receptor (mGluR3/5), NMDA-ionotropic glutamatergic receptor (NR1/2A/2B/2C) and AMPA-ionotropic receptor subunits (GluR1/2/3/4)] 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-arachidonylglycerol (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

  16. Effects of repeated exposure of diazinon on cholinesterase activity and growth in snakehead fish (Channa striata).

    Science.gov (United States)

    Cong, Nguyen Van; Phuong, Nguyen Thanh; Bayley, Mark

    2009-03-01

    The organophosphate insecticide diazinon is widely used in the Mekong river delta and often applied several times per rice crop. In the present study, juvenile snakehead fish Channa striata, which is a commercially important inhabitant of rice fields, were exposed twice to 4-day pulses of 0.016, 0.079 or 0.35mg/L of diazinon, separated by a 2 week interval to imitate the exposure conditions in the field. After the 4-day exposures to these environmentally realistic concentrations, the fish were moved to clean water for recovery. During this experiment, which lasted a total of 2 months, the individual growth rates and brain cholinesterase levels were measured. We show not only that diazinon caused long term inhibition of brain ChE activity, which was still significantly depressed at the termination of the experiment, but also that the highest of these realistic concentrations caused a significant 30% growth inhibition.

  17. Better executive function under stress mitigates the effects of recent life stress exposure on health in young adults.

    Science.gov (United States)

    Shields, Grant S; Moons, Wesley G; Slavich, George M

    2017-01-01

    Executive function is a neuropsychological construct that enables controlled cognitive processing, which has been hypothesized to enhance individuals' resilience to stress. However, little empirical work has directly examined how executive function under different conditions mitigates the negative effects of stress exposure on health. To address this issue, we recruited 110 healthy young adults and assessed their recent life stress exposure, executive function in either a stressful or non-stressful context, and current health complaints. Based on existing research, we hypothesized that individuals exhibiting better executive function following a laboratory-based stressor (but not a control task) would demonstrate weaker associations between recent stress exposure and health because they perceived recent life stressors as being less severe. Consistent with this hypothesis, better executive function during acute stress, but not in the absence of stress, was associated with an attenuated link between participants' recent life stress exposure and their current health complaints. Moreover, this attenuating effect was mediated by lesser perceptions of stressor severity. Based on these data, we conclude that better executive function under stress is associated with fewer health complaints and that these effects may occur by reducing individuals' perceptions of stressor severity. The data thus suggest the possibility of reducing stress-related health problems by enhancing executive function.

  18. Better executive function under stress mitigates the effects of recent life stress exposure on health in young adults

    Science.gov (United States)

    Shields, Grant S.; Moons, Wesley G.; Slavich, George M.

    2017-01-01

    Executive function is a neuropsychological construct that enables controlled cognitive processing, which has been hypothesized to enhance individuals’ resilience to stress. However, little empirical work has directly examined how executive function under different conditions mitigates the negative effects of stress exposure on health. To address this issue, we recruited 110 healthy young adults and assessed their recent life stress exposure, executive function in either a stressful or non-stressful context, and current health complaints. Based on existing research, we hypothesized that individuals exhibiting better executive function following a laboratory-based stressor (but not a control task) would demonstrate weaker associations between recent stress exposure and health because they perceived recent life stressors as being less severe. Consistent with this hypothesis, better executive function during acute stress, but not in the absence of stress, was associated with an attenuated link between participants’ recent life stress exposure and their current health complaints. Moreover, this attenuating effect was mediated by lesser perceptions of stressor severity. Based on these data, we conclude that better executive function under stress is associated with fewer health complaints and that these effects may occur by reducing individuals’ perceptions of stressor severity. The data thus suggest the possibility of reducing stress-related health problems by enhancing executive function. PMID:28114849

  19. Effects of chronic dietary selenomethionine exposure on repeat swimming performance, aerobic metabolism and methionine catabolism in adult zebrafish (Danio rerio).

    Science.gov (United States)

    Thomas, Jith K; Wiseman, Steve; Giesy, John P; Janz, David M

    2013-04-15

    In a previous study we reported impaired swimming performance and greater stored energy in adult zebrafish (Danio rerio) after chronic dietary exposure to selenomethionine (SeMet). The goal of the present study was to further investigate effects of chronic exposure to dietary SeMet on repeat swimming performance, oxygen consumption (MO2), metabolic capacities (standard metabolic rate [SMR], active metabolic rate [AMR], factorial aerobic scope [F-AS] and cost of transport [COT]) and gene expression of energy metabolism and methionine catabolism enzymes in adult zebrafish. Fish were fed SeMet at measured concentrations of 1.3, 3.4, 9.8 or 27.5 μg Se/g dry mass (d.m.) for 90 d. At the end of the exposure period, fish from each treatment group were divided into three subgroups: (a) no swim, (b) swim, and (c) repeat swim. Fish from the no swim group were euthanized immediately at 90 d and whole body triglycerides, glycogen and lactate, and gene expression of energy metabolism and methionine catabolism enzymes were determined. Individual fish from the swim group were placed in a swim tunnel respirometer and swimming performance was assessed by determining the critical swimming speed (U(crit)). After both Ucrit and MO2 analyses, fish were euthanized and whole body energy stores and lactate were determined. Similarly, individual fish from the repeat swim group were subjected to two U(crit) tests (U(crit-1) and U(crit-2)) performed with a 60 min recovery period between tests, followed by determination of energy stores and lactate. Impaired swim performance was observed in fish fed SeMet at concentrations greater than 3 μg Se/g in the diet. However, within each dietary Se treatment group, no significant differences between single and repeat U(crits) were observed. Oxygen consumption, SMR and COT were significantly greater, and F-AS was significantly lesser, in fish fed SeMet. Whole body triglycerides were proportional to the concentration of SeMet in the diet. While

  20. Repeated exposure to neurotoxic levels of chlorpyrifos alters hippocampal expression of neurotrophins and neuropeptides.

    Science.gov (United States)

    Lee, Young S; Lewis, John A; Ippolito, Danielle L; Hussainzada, Naissan; Lein, Pamela J; Jackson, David A; Stallings, Jonathan D

    2016-01-18

    Chlorpyrifos (CPF), an organophosphorus pesticide (OP), is one of the most widely used pesticides in the world. Subchronic exposures to CPF that do not cause cholinergic crisis are associated with problems in cognitive function (i.e., learning and memory deficits), but the biological mechanism(s) underlying this association remain speculative. To identify potential mechanisms of subchronic CPF neurotoxicity, adult male Long Evans (LE) rats were administered CPF at 3 or 10mg/kg/d (s.c.) for 21 days. We quantified mRNA and non-coding RNA (ncRNA) expression profiles by RNA-seq, microarray analysis and small ncRNA sequencing technology in the CA1 region of the hippocampus. Hippocampal slice immunohistochemistry was used to determine CPF-induced changes in protein expression and localization patterns. Neither dose of CPF caused overt clinical signs of cholinergic toxicity, although after 21 days of exposure, cholinesterase activity was decreased to 58% or 13% of control levels in the hippocampus of rats in the 3 or 10mg/kg/d groups, respectively. Differential gene expression in the CA1 region of the hippocampus was observed only in the 10mg/kg/d dose group relative to controls. Of the 1382 differentially expressed genes identified by RNA-seq and microarray analysis, 67 were common to both approaches. Differential expression of six of these genes (Bdnf, Cort, Crhbp, Nptx2, Npy and Pnoc) was verified in an independent CPF exposure study; immunohistochemistry demonstrated that CRHBP and NPY were elevated in the CA1 region of the hippocampus at 10mg/kg/d CPF. Gene ontology enrichment analysis suggested association of these genes with receptor-mediated cell survival signaling pathways. miR132/212 was also elevated in the CA1 hippocampal region, which may play a role in the disruption of neurotrophin-mediated cognitive processes after CPF administration. These findings identify potential mediators of CPF-induced neurobehavioral deficits following subchronic exposure to CPF at

  1. Over-representation of repeats in stress response genes: a strategy to increase versatility under stressful conditions?

    OpenAIRE

    Rocha, Eduardo P. C.; Matic, Ivan; Taddei, François

    2002-01-01

    The survival of individual organisms facing stress is enhanced by the induction of a set of changes. As the intensity, duration and nature of stress is highly variable, the optimal response to stress may be unpredictable. To face such an uncertain future, it may be advantageous for a clonal population to increase its phenotypic heterogeneity (bet-hedging), ensuring that at least a subset of cells would survive the current stress. With current techniques, assessing the extent of this variabili...

  2. Environmental heat stress modulates thyroid status and its response to repeated endotoxin challenge in steers.

    Science.gov (United States)

    Kahl, S; Elsasser, T H; Rhoads, R P; Collier, R J; Baumgard, L H

    2015-07-01

    The objective of this study was to evaluate in cattle, the effects of acute exposure to a heat stress (HS) environment on the status of the pituitary (thyrotropin, TSH)-thyroid (thyroxine, T4)-peripheral tissue T4 deiodination (type 1 5'-deiodinase [D1]; triiodothyronine [T3]; reverse-triiodothyronine [rT3]) axis, and the further response of this pituitary-thyroid-peripheral tissue axis (PTTA) to perturbation caused by the induction of the proinflammatory innate immune state provoked by the administration of gram-negative bacteria endotoxin (lipopolysaccharide [LPS]). Ten steers (318 ± 49 kg body weight) housed in controlled environment chambers were subjected to either a thermoneutral (TN: constant 19°C) or HS temperature conditions (cyclical daily temperatures: 32.2°C-40.0°C) for a total period of 9 d. To minimize the effects of altered plane of nutrition due to HS, steers in TN were pair-fed to animals in HS conditions. Steers received 2 LPS challenges 3 d apart (LPS1 and LPS2; 0.2 μg/kg body weight, intravenously, Escherichia coli 055:B5) with the first challenge administered on day 4 relative to the start of the environmental conditioning. Jugular blood samples were collected at 0, 1, 2, 4, 7, and 24 h relative to the start of each LPS challenge. Plasma TSH, T4, T3, and rT3 were measured by radioimmunoassay. Liver D1 activity was measured in biopsy samples collected before the LPS1 (0 h) and 24 h after LPS2. Before the start of LPS1, HS decreased (P thyroid components of the PTTA, whereas a normal capacity to generate T3 from T4 in the liver is preserved. The data also suggest that LPS challenge further suppresses all components of the PTTA including liver T3 generation, and these PTTA perturbations are more pronounced in steers that encounter a HS exposure. Published by Elsevier Inc.

  3. Hyperalgesic priming (type II) induced by repeated opioid exposure: maintenance mechanisms.

    Science.gov (United States)

    Araldi, Dioneia; Ferrari, Luiz F; Levine, Jon D

    2017-07-01

    We previously developed a model of opioid-induced neuroplasticity in the peripheral terminal of the nociceptor that could contribute to opioid-induced hyperalgesia, type II hyperalgesic priming. Repeated administration of mu-opioid receptor (MOR) agonists, such as DAMGO, at the peripheral terminal of the nociceptor, induces long-lasting plasticity expressed, prototypically as opioid-induced hyperalgesia and prolongation of prostaglandin E2-induced hyperalgesia. In this study, we evaluated the mechanisms involved in the maintenance of type II priming. Opioid receptor antagonist, naloxone, induced hyperalgesia in DAMGO-primed paws. When repeatedly injected, naloxone-induced hyperalgesia, and hyperalgesic priming, supporting the suggestion that maintenance of priming involves changes in MOR signaling. However, the knockdown of MOR with oligodeoxynucleotide antisense did not reverse priming. Mitogen-activated protein kinase and focal adhesion kinase, which are involved in the Src signaling pathway, previously implicated in type II priming, also inhibited the expression, but not maintenance of priming. However, when Src and mitogen-activated protein kinase inhibitors were coadministered, type II priming was reversed, in male rats. A second model of priming, latent sensitization, induced by complete Freund's adjuvant was also reversed, in males. In females, the inhibitor combination was only able to inhibit the expression and maintenance of DAMGO-induced priming when knockdown of G-protein-coupled estrogen receptor 30 (GPR30) in the nociceptor was performed. These findings demonstrate that the maintenance of DAMGO-induced type II priming, and latent sensitization is mediated by an interaction between, Src and MAP kinases, which in females is GPR30 dependent.

  4. Anxiety Sensitivity Among First-Time Fathers Moderates the Relationship Between Exposure to Stress During Birth and Posttraumatic Stress Symptoms.

    Science.gov (United States)

    Zerach, Gadi; Magal, Ortal

    2016-05-01

    This longitudinal study examined posttraumatic stress disorder (PTSD) and anxiety symptoms among men attending the birth of their first offspring. Furthermore, we examined the moderating role of anxiety sensitivity (AS) and intolerance of uncertainty in the association between exposure to stress during birth and PTSD and anxiety symptoms. Participants were Israeli men (n = 171) who were assessed with self-report questionnaires during the third trimester of pregnancy (T1) and approximately a month following birth (T2). Results show that the rates of postnatal PTSD and anxiety symptoms were relatively low. Subjective exposure to stress during birth and AS predicted PTSD in T2, above and beyond other negative life events and PTSD in T1. In addition, AS moderated the relations between subjective exposure to stress during birth and PTSD symptoms. Pregnancy and childbirth professionals may benefit from the insight that men with high levels of AS might experience childbirth as a highly stressful situation with possible posttraumatic stress symptoms.

  5. Neurobehavioral toxicity of a repeated exposure (14 days to the airborne polycyclic aromatic hydrocarbon fluorene in adult Wistar male rats.

    Directory of Open Access Journals (Sweden)

    Julie Peiffer

    Full Text Available Fluorene is one of the most abundant polycyclic aromatic hydrocarbons in air and may contribute to the neurobehavioral alterations induced by the environmental exposure of humans to PAHs. Since no data are available on fluorene neurotoxicity, this study was conducted in adult rats to assess the behavioral toxicity of repeated fluorene inhalation exposure. Male rats (n = 18/group were exposed nose-only to 1.5 or 150 ppb of fluorene 6 hours/day for 14 consecutive days, whereas the control animals were exposed to non-contaminated air. At the end of the exposure, animals were tested for activity and anxiety in an open-field and in an elevated-plus maze, for short-term memory in a Y-maze, and for spatial learning in an eight-arm maze. The results showed that the locomotor activity and the learning performances of the animals were unaffected by fluorene. In parallel, the fluorene-exposed rats showed a lower level of anxiety than controls in the open-field, but not in the elevated-plus maze, which is probably due to a possible difference in the aversive feature of the two mazes. In the same animals, increasing blood and brain levels of fluorene monohydroxylated metabolites (especially the 2-OH fluorene were detected at both concentrations (1.5 and 150 ppb, demonstrating the exposure of the animals to the pollutant and showing the ability of this compound to be metabolized and to reach the cerebral compartment. The present study highlights the possibility for a 14-day fluorene exposure to induce some specific anxiety-related behavioral disturbances, and argues in favor of the susceptibility of the adult brain when exposed to volatile fluorene.

  6. Effects of heat exposure and 3% dehydration achieved via hot water immersion on repeated cycle sprint performance.

    Science.gov (United States)

    Kraft, Justin A; Green, James M; Bishop, Phillip A; Richardson, Mark T; Neggers, Yasmin H; Leeper, James D

    2011-03-01

    This study examined effects of heat exposure with and without dehydration on repeated anaerobic cycling. Males (n = 10) completed 3 trials: control (CT), water-bath heat exposure (∼39°C) to 3% dehydration (with fluid replacement) (HE), and similar heat exposure to 3% dehydration (DEHY). Hematocrit increased significantly from pre to postheat immersion in both HE and DEHY. Participants performed 6 × 15s cycle sprints (30s active recovery). Mean Power (MP) was significantly lower vs. CT (596 ± 66 W) for DEHY (569 ± 72 W), and the difference approached significance for HE (582 ± 76 W, p = 0.07). Peak Power (PP) was significantly lower vs. CT (900 ± 117 W) for HE (870 ± 128 W) and approached significance for DEHY (857 ± 145 W, p = 0.07). Postsprint ratings of perceived exertion was higher during DEHY (6.4 ± 2.0) and HE (6.3 ± 1.6) than CT (5.7 ± 2.1). Combined heat and dehydration impaired MP and PP (decrements greatest in later bouts) with HE performance intermediate to CT and DEHY.

  7. Tolerance to repeated stress in rats with lesions of the serotoninergic neurons of the Median Raphe Nucleus and chronically treated with imipramine.

    Science.gov (United States)

    Silva, K; Carvalho, M C; Padovan, C M

    2016-04-01

    Repeated exposure to aversive events leads to the development of tolerance to stress, which involves the serotonergic pathway originated in the Median Raphe Nucleus (MnRN) to the Dorsal Hippocampus (DH). However, it is not clear whether these lesion-induced deficits can be attenuated by treatment with antidepressants. Therefore, the aim of this work was to investigate the effects of chronic treatment with Imipramine (IMI) in rats with lesions in the MnRN and exposed to restraint stress. Male Wistar rats with or without neurochemical lesions of the MnRN serotonergic neurons with the neurotoxin 5,7-DHT were submitted to acute (2h) or chronic restraint (2h/day/seven consecutive days) and treated with saline (1 ml/kg) or imipramine (15 mg/kg) via intraperitoneal twice a day during the same period. In acutely restrained rats, stress occurred on the last day of treatment. Test in the elevated plus maze (EPM) was performed 24h later. After EPM test, animals were sacrificed and had their brains removed. Dorsal hippocampus and striatum were dissected and the levels of 5-HT and 5-hydroxy-indoleacetic acid (5-HIAA) measured by HPLC analysis. Our results showed that in control rats exposure to acute restraint stress decreased exploration of the open and enclose arms of the EPM, an effect that was attenuated by imipramine. In rats with 5,7-DHT lesions, acute restraint did not change the exploration of the EPM, independently of the treatment. On the other hand, when chronically restrained, saline treated rat with 5,7-DHT lesion showed a reduced exploration of the open arms of the EPM. This effect was attenuated by simultaneous treatment with imipramine. HPLC analysis showed significantly decreases on 5-HT and 5-HIAA levels in the hippocampus, but not in the striatum. These later results confirm that 5,7-DHT lesions of the MnRN had significant impact on the serotonergic projections to the dorsal hippocampus which seems to be essential for the development of tolerance to repeated

  8. Motion sickness severity and physiological correlates during repeated exposures to a rotating optokinetic drum

    Science.gov (United States)

    Hu, Senqi; Grant, Wanda F.; Stern, Robert M.; Koch, Kenneth L.

    1991-01-01

    Fifty-two subjects were exposed to a rotating optokinetic drum. Ten of these subjects who became motion sick during the first session completed two additional sessions. Subjects' symptoms of motion sickness, perception of self-motion, electrogastrograms (EGGs), heart rate, mean successive differences of R-R intervals (RRI), and skin conductance were recorded for each session. The results from the first session indicated that the development of motion sickness was accompanied by increased EGG 4-9 cpm activity (gastric tachyarrhythmia), decreased mean succesive differences of RRI, increased skin conductance levels, and increased self-motion perception. The results from the subjects who had three repeated sessions showed that 4-9 cpm EGG activity, skin conductance levels, perception of self-motion, and symptoms of motion sickness all increased significantly during the drum rotation period of the first session, but increased significantly less during the following sessions. Mean successive differences of RRI decreased significantly during the drum rotation period for the first session, but decreased significantly less during the following sessions. Results show that the development of motion sickness is accompanied by an increase in gastric tachyarrhythmia, and an increase in sympathetic activity and a decrease in parasympathetic activity, and that adaptation to motion sickness is accompanied by the recovery of autonomic nervous system balance.

  9. Perfluorooctanoic acid exposure triggers oxidative stress in the mouse pancreas

    Directory of Open Access Journals (Sweden)

    Lisa M. Kamendulis

    2014-01-01

    Full Text Available Perfluorooctanoic acid (PFOA is used in the manufacture of many industrial and commercial products. PFOA does not readily decompose in the environment, and is biologically persistent. Human epidemiologic and animal studies suggest that PFOA exposure elicits adverse effects on the pancreas. While multiple animal studies have examined PFOA-mediated toxicity in the liver, little is known about the potential adverse effects of PFOA on the pancreas. To address this, we treated C57Bl/6 mice with vehicle, or PFOA at doses of 0.5, 2.5 or 5.0 mg/kg BW/day for 7 days. Significant accumulation of PFOA was found in the serum, liver and pancreas of PFOA-treated animals. Histopathologic examination of the pancreas revealed focal ductal hyperplasia in mice treated with 2.5 and 5.0 mg/kg BW/day PFOA, while inflammation was observed only in the high dose group. Elevated serum levels of amylase and lipase were observed in the 2.5 mg/kg BW/day PFOA treatment group. In addition, PFOA exposure resulted in a dose-dependent increase in the level of the lipid peroxidation product 8-iso-PGF2α and induction of the antioxidant response genes Sod1, Sod2, Gpx2 and Nqo1. Our findings provide additional evidence that the pancreas is a target organ for PFOA-mediated toxicity and suggest that oxidative stress may be a mechanism through which PFOA induces histopathological changes in the pancreas.

  10. Emotion Dysregulation as a Mechanism Linking Stress Exposure to Adolescent Aggressive Behavior

    Science.gov (United States)

    Herts, Kate L.; McLaughlin, Katie A.; Hatzenbuehler, Mark L.

    2012-01-01

    Exposure to stress is associated with a wide range of internalizing and externalizing problems in adolescents, including aggressive behavior. Extant research examining mechanisms underlying the associations between stress and youth aggression has consistently identified social information processing pathways that are disrupted by exposure to…

  11. Posttraumatic Stress in U.S. Marines: The Role of Unit Cohesion and Combat Exposure

    Science.gov (United States)

    Armistead-Jehle, Patrick; Johnston, Scott L.; Wade, Nathaniel G.; Ecklund, Christofer J.

    2011-01-01

    Combat exposure is a consistent predictor of posttraumatic stress (PTS). Understanding factors that might buffer the effects of combat exposure is crucial for helping service members weather the stress of war. In a study of U.S. Marines returning from Iraq, hierarchical multiple regression analyses revealed that unit cohesion and combat exposure…

  12. Repeated administration of AC-5216, a ligand for the 18 kDa translocator protein, improves behavioral deficits in a mouse model of post-traumatic stress disorder.

    Science.gov (United States)

    Qiu, Zhi-Kun; Zhang, Li-Ming; Zhao, Nan; Chen, Hong-Xia; Zhang, You-Zhi; Liu, Yan-Qin; Mi, Tian-Yue; Zhou, Wen-Wen; Li, Yang; Yang, Ri-Fang; Xu, Jiang-Ping; Li, Yun-Feng

    2013-08-01

    Post-traumatic stress disorder (PTSD) is a severely disabling anxiety disorder that may occur following exposure to a serious traumatic event. It is a psychiatric condition that can afflict anyone who has experienced a life-threatening or violent event. Previous studies have shown that changes in 18 kDa translocator protein (TSPO) expression (or function), a promising target for treating neurological disorders without benzodiazepine-like side effects, may correlate with PTSD. However, few studies have investigated the anti-PTSD effects of TSPO ligands. AC-5216, a ligand for TSPO, induces anxiolytic- and anti-depressant-like effects in animal models. The present study aimed to determine whether AC-5216 ameliorates PTSD behavior in mice. Following the training session consisting of exposure to inescapable electric foot shocks, animals were administered AC-5216 daily during the behavioral assessments, i.e., situational reminders (SRs), the open field (OF) test, the elevated plus-maze (EPM) test, and the staircase test (ST). The results indicated that exposure to foot shocks induced long-term behavioral deficiencies in the mice, including freezing and anxiety-like behavior, which were significantly ameliorated by repeated treatment with AC-5216 but without any effect on spontaneous locomotor activity or body weight. In summary, this study demonstrated the anti-PTSD effects of AC-5216 treatment, suggesting that TSPO may represent a therapeutic target for anti-PTSD drug discovery and that TSPO ligands may be a promising new class of drugs for the future treatment of PTSD.

  13. Changes in homologous recombination frequency in Arabidopsis thaliana plants exposed to stress depend on time of exposure during development and on duration of stress exposure.

    Science.gov (United States)

    Rahavi, Seyed Mohammad Reza; Kovalchuk, Igor

    2013-10-01

    In the past, we showed that exposure to abiotic and biotic stresses changes the homologous recombination frequency (HRF) in somatic tissue and in the progeny. In current work we planned to answer the following question: do stress intensity/duration and time during exposure influence changes in somatic HRF and transgenerational changes in HRF? Here, we tested the effects of exposure to UV-C, cold and heat on HRF at 7, 14, 21 and 28 days post germination (dpg). We found that exposure at 14 and 21 dpg resulted in a higher increase in HRF as compared to exposure at 7 dpg; longer exposure to UV-C resulted in a higher frequency of HR, whereas prolonged exposure to cold or heat, especially at later developmental stages, had almost no effect on somatic HRF. Exposure at 7 dpg had a positive effect on somatic growth of plants; plants exposed to stress at this age had larger leaves. The analysis of HRF in the progeny showed that the progeny of plants exposed to stress at 7 dpg had an increase in somatic HRF and showed larger sizes of recombination spots on leaves. The progeny of plants exposed to UV-C at 7 dpg and the progeny of plants exposed to cold or heat at 28 dpg had larger leaves as compared to control plants. To summarize, our experiments showed that changes in somatic and transgenerational HRF depend on the type of stress plants are exposed to, time of exposure during development and the duration of exposure.

  14. Greater physiological and behavioral effects of interrupted stress pattern compared to daily restraint stress in rats.

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    Full Text Available Repeated stress can trigger a range of psychiatric disorders, including anxiety. The propensity to develop abnormal behaviors after repeated stress is related to the severity, frequency and number of stressors. However, the pattern of stress exposure may contribute to the impact of stress. In addition, the anxiogenic nature of repeated stress exposure can be moderated by the degree of coping that occurs, and can be reflected in homotypic habituation to the repeated stress. However, expectations are not clear when a pattern of stress presentation is utilized that diminishes habituation. The purpose of these experiments is to test whether interrupted stress exposure decreases homotypic habituation and leads to greater effects on anxiety-like behavior in adult male rats. We found that repeated interrupted restraint stress resulted in less overall homotypic habituation compared to repeated daily restraint stress. This was demonstrated by greater production of fecal boli and greater corticosterone response to restraint. Furthermore, interrupted restraint stress resulted in a lower body weight and greater adrenal gland weight than daily restraint stress, and greater anxiety-like behavior in the elevated plus maze. Control experiments demonstrated that these effects of the interrupted pattern could not be explained by differences in the total number of stress exposures, differences in the total number of days that the stress periods encompased, nor could it be explained as a result of only the stress exposures after an interruption from stress. These experiments demonstrate that the pattern of stress exposure is a significant determinant of the effects of repeated stress, and that interrupted stress exposure that decreases habituation can have larger effects than a greater number of daily stress exposures. Differences in the pattern of stress exposure are therefore an important factor to consider when predicting the severity of the effects of repeated

  15. Glucocorticoids regulation of FosB/ΔFosB expression induced by chronic opiate exposure in the brain stress system.

    Directory of Open Access Journals (Sweden)

    Daniel García-Pérez

    Full Text Available Chronic use of drugs of abuse profoundly alters stress-responsive system. Repeated exposure to morphine leads to accumulation of the transcription factor ΔFosB, particularly in brain areas associated with reward and stress. The persistent effects of ΔFosB on target genes may play an important role in the plasticity induced by drugs of abuse. Recent evidence suggests that stress-related hormones (e.g., glucocorticoids, GC may induce adaptations in the brain stress system that is likely to involve alteration in gene expression and transcription factors. This study examined the role of GC in regulation of FosB/ΔFosB in both hypothalamic and extrahypothalamic brain stress systems during morphine dependence. For that, expression of FosB/ΔFosB was measured in control (sham-operated and adrenalectomized (ADX rats that were made opiate dependent after ten days of morphine treatment. In sham-operated rats, FosB/ΔFosB was induced after chronic morphine administration in all the brain stress areas investigated: nucleus accumbens(shell (NAc, bed nucleus of the stria terminalis (BNST, central amygdala (CeA, hypothalamic paraventricular nucleus (PVN and nucleus of the solitary tract noradrenergic cell group (NTS-A(2. Adrenalectomy attenuated the increased production of FosB/ΔFosB observed after chronic morphine exposure in NAc, CeA, and NTS. Furthermore, ADX decreased expression of FosB/ΔFosB within CRH-positive neurons of the BNST, PVN and CeA. Similar results were obtained in NTS-A(2 TH-positive neurons and NAc pro-dynorphin-positive neurons. These data suggest that neuroadaptation (estimated as accumulation of FosB/ΔFosB to opiates in brain areas associated with stress is modulated by GC, supporting the evidence of a link between brain stress hormones and addiction.

  16. Chronic intermittent ethanol exposure during adolescence: Effects on stress-induced social alterations and social drinking in adulthood.

    Science.gov (United States)

    Varlinskaya, Elena I; Kim, Esther U; Spear, Linda P

    2017-01-01

    We previously observed lasting and sex-specific detrimental consequences of early adolescent intermittent ethanol exposure (AIE), with male, but not female, rats showing social anxiety-like alterations when tested as adults. The present study used Sprague Dawley rats to assess whether social alterations induced by AIE (3.5g/kg, intragastrically, every other day, between postnatal days [P] 25-45) are further exacerbated by stressors later in life. Another aim was to determine whether AIE alone or in combination with stress influenced intake of a sweetened ethanol solution (Experiment 1) or a sweetened solution ("supersac") alone (Experiment 2) under social circumstances. Animals were exposed to restraint on P66-P70 (90min/day) or left nonstressed, with corticosterone (CORT) levels assessed on day 1 and day 5 in Experiment 2. Social anxiety-like behavior emerged after AIE in non-stressed males, but not females, whereas stress-induced social anxiety was evident only in water-exposed males and females. Adult-typical habituation of the CORT response to repeated restraint was not evident in adult animals after AIE, a lack of habituation reminiscent of that normally evident in adolescents. Neither AIE nor stress affected ethanol intake under social circumstances, although AIE and restraint independently increased adolescent-typical play fighting in males during social drinking. Among males, the combination of AIE and restraint suppressed "supersac" intake; this index of depression-like behavior was not seen in females. The results provide experimental evidence associating adolescent alcohol exposure, later stress, anxiety, and depression, with young adolescent males being particularly vulnerable to long-lasting adverse effects of repeated ethanol. This article is part of a Special Issue entitled SI: Adolescent plasticity. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Icariin attenuates glucocorticoid insensitivity mediated by repeated psychosocial stress on an ovalbumin-induced murine model of asthma.

    Science.gov (United States)

    Li, Bei; Duan, Xiaohong; Xu, Changqing; Wu, Jinfeng; Liu, Baojun; Du, Yiji; Luo, Qingli; Jin, Hualiang; Gong, Weiyi; Dong, Jingcheng

    2014-04-01

    Evidence shows that psychosocial stress exacerbates asthma, but there is little intervention to alleviate negative effects of psychosocial stress on asthma. We investigated the role of icariin in anti-inflammation and anti-anxiety potential in a murine model combined psychosocial stress with allergic exposure. The results indicated that icariin administered remarkable increased activity in the center of the open field, reversed airway hyperresponsivenesss, reduced inflammatory cytokine infiltration to the lung and whole body and also in part recovered glucocorticoid responsiveness. Furthermore, our data also showed that icariin significantly inhibited increases of corticosterone and markedly increased glucocorticoid receptor mRNA and protein expression in the lungs of mice exposed to both stress and allergen. Collectively, we speculate that inducing glucocorticoid receptor modulation might be the potential mechanisms of icariin to facilitate corticosteroid responsiveness of cytokine production.

  18. Baseline and stress-induced glucocorticoid concentrations are not repeatable but covary within individual great tits (Parus major).

    Science.gov (United States)

    Baugh, Alexander T; van Oers, Kees; Dingemanse, Niels J; Hau, Michaela

    2014-11-01

    In evolutionary endocrinology, there is a growing interest in the extent and basis of individual variation in endocrine traits, especially circulating concentrations of hormones. This is important because if targeted by selection, such individual differences present the opportunity for an evolutionary response to selection. It is therefore necessary to examine whether hormone traits are repeatable in natural populations. However, research in this area is complicated by the fact that different hormone traits can be correlated. The nature of these trait correlations (i.e., phenotypic, within-, or among-individual) is critically relevant in terms of the evolutionary implications, and these in turn, depend on the repeatability of each hormone trait. By decomposing phenotypic correlations between hormone traits into their within- and among-individual components it is possible to describe the multivariate nature of endocrine traits and generate inferences about their evolution. In the present study, we repeatedly captured individual great tits (Parus major) from a wild population and measured plasma concentrations of corticosterone. Using a mixed-modeling approach, we estimated repeatabilities in both initial (cf. baseline; CORT0) and stress-induced concentrations (CORT30) and the correlations between those traits among- and within-individuals. We found a lack of repeatability in both CORT0 and CORT30. Moreover, we found a strong phenotypic correlation between CORT0 and CORT30, and due to the lack of repeatability for both traits, there was no among-individual correlation between these two traits-i.e., an individual's average concentration of CORT0 was not correlated with its average concentration of CORT30. Instead, the phenotypic correlation was the result of a strong within-individual correlation, which implies that an underlying environmental factor co-modulates changes in initial and stress-induced concentrations within the same individual over time. These results

  19. Effects of repeated exposure to 4-nonylphenol on the zooplankton community in littoral enclosures

    Energy Technology Data Exchange (ETDEWEB)

    O`Halloran, S.L.; Liber, K.; Gangl, J.A. [Univ. of Wisconsin, Superior, WI (United States). Lake Superior Research Inst.; Knuth, M.L. [Environmental Protection Agency, Duluth, MN (United States). Mid-Continent Ecology Div.

    1999-03-01

    The effects of 4-nonylphenol (NP) on freshwater zooplankton were evaluated in 18 littoral enclosure mesocosms in northeastern Minnesota. The 18 enclosures were allocated to three blocks of six units with each block including two untreated control enclosures and one enclosure for each of four NP treatments. Treated enclosures received 11 applications of NP over a 20-d period between July 8 and 28, 1993. Maximum NP concentrations measured in the water column 2 h after each application averaged ({+-} SD) 5 {+-} 4, 23 {+-} 11, 76 {+-} 21, and 243 {+-} 41 {micro}g/L over the 11 applications. Nonylphenol dissipated rapidly from the water column but was more persistent in sediments and in/on macrophytes. All cladoceran and copepod taxa were significantly reduced in abundance at 243 {+-} 41 {micro}g/L; some sensitive taxa were also affected by 76 {+-} 21 and 23 {+-} 11 {micro}g/L. While many rotifer taxa were unaffected at any of the test concentrations, several were affected at {ge} 76 {+-} 21 {micro}g/L. Ostracods were only affected at 2,243 {+-} 41 {micro}g/L. No zooplankton taxon was affected at 5 {+-} 4 {micro}g/L. The period of maximum impact usually occurred within 1 to 7 d of the last NP application, and recovery to control abundance levels generally occurred within 7 to 28 d of the last NP application. Two sensitive taxa, Acroperus and Calanoida, did not recover at {ge} 76 {+-} 21 {micro}g/L by the end of the study. The maximum acceptable toxicant concentration for protection of all zooplankton taxa was estimated at {approximately} 10 {micro}g/L, although overall community diversity was unaffected at 23 {+-} 11. The water was the most probable route of NP exposure, but the greater persistence of NP residues in/on macrophytes may have contributed to the lack of recovery of some macrophyte-associated taxa.

  20. Effects of lifetime stress exposure on mental and physical health in young adulthood: How stress degrades and forgiveness protects health.

    Science.gov (United States)

    Toussaint, Loren; Shields, Grant S; Dorn, Gabriel; Slavich, George M

    2016-06-01

    To examine risk and resilience factors that affect health, lifetime stress exposure histories, dispositional forgiveness levels, and mental and physical health were assessed in 148 young adults. Greater lifetime stress severity and lower levels of forgiveness each uniquely predicted worse mental and physical health. Analyses also revealed a graded Stress × Forgiveness interaction effect, wherein associations between stress and mental health were weaker for persons exhibiting more forgiveness. These data are the first to elucidate the interactive effects of cumulative stress severity and forgiveness on health, and suggest that developing a more forgiving coping style may help minimize stress-related disorders.

  1. Responses of soil ammonia-oxidizing microorganisms to repeated exposure of single-walled and multi-walled carbon nanotubes.

    Science.gov (United States)

    Chen, Qinglin; Wang, Hui; Yang, Baoshan; He, Fei; Han, Xuemei; Song, Ziheng

    2015-02-01

    The impacts of carbon nanotubes (CNTs) including single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) on soil microbial biomass and microbial community composition (especially on ammonium oxidizing microorganisms) have been evaluated. The first exposure of CNTs lowered the microbial biomass immediately, but the values recovered to the level of the control at the end of the experiment despite the repeated addition of CNTs. The abundance and diversity of ammonium-oxidizing archaea (AOA) were higher than that of ammonium-oxidizing bacteria (AOB) under the exposure of CNTs. The addition of CNTs decreased Shannon-Wiener diversity index of AOB and AOA. Two-way ANOVA analysis showed that CNTs had significant effects on the abundance and diversity of AOB and AOA. Dominant terminal restriction fragments (TRFs) of AOB exhibited a positive relationship with NH4(+), while AOA was on the contrary. It implied that AOB prefer for high-NH4(+) soils whereas AOA is favored in low NH4(+) soils in the CNT-contaminated soil. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. The sensory response to capsaicin during repeated topical exposures: differential effects on sensations of itching and pungency.

    Science.gov (United States)

    Green, B G; Shaffer, G S

    1993-06-01

    Changes in sensory irritation were measured during repeated topical exposures to capsaicin over 2 days. The perceived intensities of itching and pungent sensations, predominantly burning and stinging/pricking, were assessed every 60 sec during 5 applications of capsaicin at inter-stimulus intervals (ISI) of 90 min (Exp. 1) or 15 min (Exp. 2) and in follow-up tests 24 h later. Psychophysical measurements were obtained with a hand-held dynamometer in conjunction with the method of magnitude production. When the ISI was 90 min, itching and pungency were both significantly reduced (i.e., desensitization occurred) by the fifth exposure; however, the reduction occurred more rapidly and dramatically for itching. After 24 h, desensitization remained significant only for itching. When the ISI was 15 min, the sensations on day 1 first intensified in a manner consistent with sensitization, then declined in a manner consistent with desensitization; compared to pungency, itch exhibited less sensitization and more desensitization. On day 2, overall intensity was less for both categories of sensation, primarily because of a reduction in sensitization. Marked individual differences were observed in the overall sensitivity to capsaicin, the time course of sensation, the susceptibility to capsaicin-induced itch, and the rate and duration of sensitization and desensitization. The results are discussed in terms of current hypotheses about the sensory mechanisms that underlie chemically induced itch and the use of capsaicin as a topical analgesic and antipruritic.

  3. A Study for the Characteristic Changes Under the Repeated Thermal Exposure in the Process of Repairing Aircraft Sandwich Structures

    Science.gov (United States)

    Kim, Yun Hae; Han, Joong Won; Kim, Don Won; Choi, Byung Keun; Murakami, R.

    Delamination can be observed in the sound areas during and/or after a couple times exposure to the elevated curing temperature due to the repeated repair condition. This study was conducted for checking the degree of degradation of properties of the cured parts and delamination between skin prepreg and honeycomb core. Specimens with glass honeycomb sandwich construction and glass/epoxy prepreg were prepared. The specimens were cured 1 to 5 times at 260°F in an autoclave and each additionally exposed 50, 100 and 150 hours in the 260°F oven. Each specimen was tested for tensile strength, compressive strength, flatwise tensile strength and interlaminar shear strength. To monitor the characteristics of the resin itself, the cured resin was tested using DMA and DSC. As a results, the decrease of Tg value were observed in the specific specimen which is exposed over 50 hrs at 260°F. This means the change or degradative of resin properties is also related to the decrease of flatwise tensile properties. Accordingly, minimal exposure on the curing temperature is recommended for parts in order to prevent the delation and maintain the better condition.

  4. Psychobiology of cumulative trauma: hair cortisol as a risk marker for stress exposure in women.

    Science.gov (United States)

    Morris, Matthew C; Abelson, James L; Mielock, Alyssa S; Rao, Uma

    2017-07-01

    Childhood trauma (CT) is associated with long-lasting alterations of the hypothalamic-pituitary-adrenal (HPA) axis and elevated risk for stress exposure in adulthood. Although HPA alterations are present in the early aftermath of trauma, it remains unclear how initial HPA activity is associated with subsequent stress exposure and whether CT exposure influences the strength and direction of this association. The present study examined prospective associations between hair cortisol content (HCC) and stress exposure from baseline to 3-month follow-up in young adult women with recent (i.e. past 3 months) exposure to interpersonal violence (IPV; i.e. physical or sexual assault) and non-traumatized controls. History of significant CT abuse or neglect was determined based on clinical cutoffs for a self-report CT measure: 12 women had abuse or neglect and recent IPV exposure (CT + IPV); 7 women had abuse or neglect but no IPV exposure (CT); 15 women had no history of trauma (NTC). HCC was computed for 3 cm sections reflecting cortisol secretion during the 3 months preceding the baseline assessment. The interaction of cumulative trauma and HCC predicted stress exposure over 3-month follow-up, controlling for baseline stress exposure and depressive symptoms. Simple slopes analyses revealed that lower baseline HCC predicted greater stress exposure in the CT + IPV group compared to the CT group; HCC was not associated with stress exposure in the NTC group. The present findings highlight the potential utility of HCC as a predictor of stress exposure for women with a history of childhood abuse or neglect, particularly in the context of recent IPV. Lay summary Adults with a history of CT show long-lasting alterations in major stress response systems, including the HPA axis. They are also more likely to experience stressful life events in adulthood. However, it is not clear how altered HPA activity influences risk for stress exposure and whether CT affects their

  5. Repeated static contractions increase mitochondrial vulnerability toward oxidative stress in human skeletal muscle

    DEFF Research Database (Denmark)

    Sahlin, Kent; Nielsen, Jens Steen; Mogensen, Martin

    2006-01-01

    Repeated static contractions (RSC) induce large fluctuations in tissue oxygen tension and increase the generation of reactive oxygen species (ROS). This study investigated the effect of RSC on muscle contractility, mitochondrial respiratory function, and in vitro sarcoplasmic reticulum (SR) Ca(2+...

  6. Recovery from hybrid breakdown in a marine invertebrate is faster, stronger and more repeatable under environmental stress.

    Science.gov (United States)

    Hwang, A S; Pritchard, V L; Edmands, S

    2016-09-01

    Understanding how environmental stress alters the consequences of hybridization is important, because the rate of hybridization and the likelihood of hybrid speciation both appear elevated in harsh, disturbed or marginal habitats. We assessed fitness, morphometrics and molecular genetic composition over 14 generations of hybridization between two highly divergent populations of the marine copepod Tigriopus californicus. Replicated, experimental hybrid populations in both control and high-salinity conditions showed a decline in fitness, followed by a recovery. Recovery was faster in the salinity stress treatment, returning to parental levels up to two generations earlier than in the control. This recovery was stable in the high-salinity treatment, whereas in the control treatment, fitness dropped back below parental levels at the final time point. Recovery in the high-salinity treatment was also stronger in terms of competitive fitness and heat-shock tolerance. Finally, consequences of hybridization were more repeatable under salinity stress, where among-replicate variance for survivorship and molecular genetic composition was lower than in the control treatment. In a system with low effective population sizes (estimates ranged from 17 to 63), where genetic drift might be expected to be the predominate force, strong selection under harsh environmental conditions apparently promoted faster, stronger and more repeatable recovery from depressed hybrid fitness.

  7. Repeated Cycles of Chronic Intermittent Ethanol Exposure Increases Basal Glutamate in the Nucleus Accumbens of Mice without affecting glutamate transport

    Directory of Open Access Journals (Sweden)

    William C. Griffin

    2015-02-01

    Full Text Available Repeated cycles of chronic intermittent ethanol (CIE exposure increase voluntary consumption of ethanol in mice. Previous work has shown that extracellular glutamate in the nucleus accumbens (NAc is significantly elevated in ethanol dependent mice and that pharmacologically manipulating glutamate concentrations in the NAc will alter ethanol drinking, indicating that glutamate homeostasis plays a crucial role in ethanol drinking in this model. The present studies were designed to measure extracellular glutamate at a time point in which mice would ordinarily be allowed voluntary access to ethanol in the CIE model and, additionally, to measure glutamate transport capacity in the NAc at the same time point. Extracellular glutamate was measured using quantitative microdialysis procedures. Glutamate transport capacity was measured under Na+ dependent and Na+ independent conditions to determine whether the function of excitatory amino acid transporters (EAATs; also known as system XAG or of system Xc- (Glial cysteine-glutamate exchanger was influenced by CIE exposure. The results of the quantitative microdialysis experiment confirm increased extracellular glutamate (~2 –fold in the NAc of CIE exposed mice (i.e. ethanol-dependent compared to non-dependent mice in the NAc, consistent with earlier work. However, the increase in extracellular glutamate was not due to altered transporter function in the NAc of ethanol-dependent mice, because neither Na+ dependent nor Na+ independent glutamate transport was significantly altered by CIE exposure. These findings point to the possibility that hyperexcitability of cortical-striatal pathways underlies the increases in extracellular glutamate found in the nucleus accumbens of ethanol-dependent mice.

  8. Effect of repeated nicotine exposure on high-affinity nicotinic acetylcholine receptor density in spontaneously hypertensive rats.

    Science.gov (United States)

    Hohnadel, Elizabeth J; Hernandez, Caterina M; Gearhart, Debra A; Terry, Alvin V

    Spontaneously hypertensive rats (SHRs) are often used as a model of attention deficit hyperactivity disorder (ADHD) and to investigate the effects of hypertension on cognitive function. Further, they appear to have reduced numbers of central nicotinic acetylcholine receptors (nAChRs) and, therefore, may be useful to model certain aspects of Alzheimer's disease (AD) and other forms of dementia given that a decrease in nAChRs is thought to contribute to cognitive decline in these disorders. In the present study, based on reports that chronic nicotine exposure increases nAChRs in several mammalian models, we tested the hypothesis that repeated exposures to a relatively low dose of the alkaloid would ameliorate the receptor deficits in SHR. Thus, young-adult SHRs and age-matched Wistar-Kyoto (WKY) control rats were treated with either saline or nicotine twice a day for 14 days (total daily dose = 0.7 mg/kg nicotine base) and then sacrificed. Quantitative receptor autoradiography with [125I]-IPH, an epibatidine analog, revealed: (1) that high-affinity nAChRs were higher in saline-treated WKY (control) rats compared to saline-treated SHRs in 18 of the 19 brain region measured, although statistically different only in the mediodorsal thalamic nuclei, (2) that nicotine significantly increased nAChR binding in WKY rats in six brain areas including cortical regions and the anterior thalamic nucleus, (3) that there were no cases where nicotine significantly increased nAChR binding in SHRs. These results indicate that subjects deficient in nAChRs may be less sensitive to nAChR upregulation with nicotine than normal subjects and require higher doses or longer periods of exposure.

  9. Global gradients of coral exposure to environmental stresses and implications for local management.

    Directory of Open Access Journals (Sweden)

    Joseph Maina

    Full Text Available BACKGROUND: The decline of coral reefs globally underscores the need for a spatial assessment of their exposure to multiple environmental stressors to estimate vulnerability and evaluate potential counter-measures. METHODOLOGY/PRINCIPAL FINDINGS: This study combined global spatial gradients of coral exposure to radiation stress factors (temperature, UV light and doldrums, stress-reinforcing factors (sedimentation and eutrophication, and stress-reducing factors (temperature variability and tidal amplitude to produce a global map of coral exposure and identify areas where exposure depends on factors that can be locally managed. A systems analytical approach was used to define interactions between radiation stress variables, stress reinforcing variables and stress reducing variables. Fuzzy logic and spatial ordinations were employed to quantify coral exposure to these stressors. Globally, corals are exposed to radiation and reinforcing stress, albeit with high spatial variability within regions. Based on ordination of exposure grades, regions group into two clusters. The first cluster was composed of severely exposed regions with high radiation and low reducing stress scores (South East Asia, Micronesia, Eastern Pacific and the central Indian Ocean or alternatively high reinforcing stress scores (the Middle East and the Western Australia. The second cluster was composed of moderately to highly exposed regions with moderate to high scores in both radiation and reducing factors (Caribbean, Great Barrier Reef (GBR, Central Pacific, Polynesia and the western Indian Ocean where the GBR was strongly associated with reinforcing stress. CONCLUSIONS/SIGNIFICANCE: Despite radiation stress being the most dominant stressor, the exposure of coral reefs could be reduced by locally managing chronic human impacts that act to reinforce radiation stress. Future research and management efforts should focus on incorporating the factors that mitigate the effect of

  10. Cognitive and neuroinflammatory consequences of mild repeated stress are exacerbated in aged mice

    Science.gov (United States)

    Buchanan, J.B.; Sparkman, N.L.; Chen, J.; Johnson, R.W.

    2008-01-01

    Summary Peripheral immune stimulation as well as certain types of psychological stress increases brain levels of inflammatory cytokines such as interleukin-1β (IL-1β), IL-6 and tumor necrosis factor α (TNFα). We have demonstrated that aged mice show greater increases in central inflammatory cytokines, as well as greater cognitive deficits, compared to adults in response to peripheral lipopolysaccharide (LPS) administration. Because aged mice are typically more sensitive to systemic stressors such as LPS, and certain psychological stressors induce physiological responses similar to those that follow LPS, we hypothesized that aged mice would be more sensitive to the physiological and cognitive effects of mild stress than adult mice. Here, adult (3–5 mo) and aged (22–23 mo) male BALB/c mice were trained in the Morris water maze for 5 days. Mice were then exposed to a mild restraint stress of 30 minutes before being tested in a working memory version of the water maze over a 3 day period. On day 4 mice were stressed and then killed for collection of blood and brain. In a separate group of animals, mice were killed immediately after one, two or three 30 min restraint sessions and blood for peripheral corticosterone and cytokine protein measurement, and brains were dissected for central cytokine mRNA measurement. Stress disrupted spatial working memory in both adult and aged mice but to a much greater extent in the aged mice. In addition, aged mice showed an increase in stress-induced expression of hippocampal IL-1β mRNA and MHC class II protein compared to non-stressed controls while expression in adult mice was unaffected by stress. These data show that aged mice are more sensitive to both the cognitive and inflammatory effects of mild stress than are adult mice and suggest a possible a role for IL-1β. PMID:18407425

  11. Effect of repeated stress in early childhood on the onset of diabetes mellitus in male Spontaneously Diabetic Torii rats.

    Science.gov (United States)

    Ookawa, Katumasa; Mochizuki, Kazuo; Yokogoshi, Hidehiko

    2008-02-01

    Spontaneously Diabetic Torii (SDT) rats were discovered from SD rats and represent a confirmed spontaneous type 2 diabetes mellitus model. We investigated the effect of repeated stress in early childhood on SDT rats fed a high-fat diet, on locomotor activity and on the onset of diabetes mellitus. Regarding stress, a water immersion-restraint stress (WIRS) burden was applied 10 times every other day from 4 weeks of age. The results of the study showed, that the locomotor activity of the young SDT rats was clearly lower than that of the SD rats, and their locomotor activity was inferred to be congenitally low. In addition, the stress-burdened SDT rats showed delayed onset of diabetes mellitus and impaired glucose tolerance compared with the rats not receiving stress burden. The locomotor activity of SDT rats is less than that of SD rats, and they SDT rats are thought to have poor at spontaneous energy expenditure. On the other hand, the feeding efficiency of the WIRS-burdened SDT rats was reduced, and in comparison with the SDT rats with no WIRS burden, energy expenditure was increased; this is suggested to influence the onset of diabetes mellitus.

  12. Effects of repeated prenatal glucocorticoid exposure on long-term potentiation in the juvenile guinea-pig hippocampus.

    Science.gov (United States)

    Setiawan, Elaine; Jackson, Michael F; MacDonald, John F; Matthews, Stephen G

    2007-06-15

    Synthetic glucocorticoids (sGCs) are routinely used to treat women at risk of preterm labour to promote fetal lung maturation. There is now strong evidence that exposure to excess glucocorticoid during periods of rapid brain development has permanent consequences for endocrine function and behaviour in the offspring. Prenatal exposure to sGC alters the expression of N-methyl-D-aspartate receptor (NMDA-R) subunits in the fetal and neonatal hippocampus. Given the integral role of the NMDA-R in synaptic plasticity, we hypothesized that prenatal sGC exposure will have effects on hippocampal long-term potentiation (LTP) after birth. Further, this may occur in either the presence or absence of elevated cortisol concentrations, in vitro. Pregnant guinea-pigs were injected with betamethasone (Beta, 1 mg kg(-1)) or vehicle on gestational days (gd) 40, 41, 50, 51, 60 and 61 (term approximately 70 days), a regimen comparable to that given to pregnant women. On postnatal day 21, LTP was examined at Schaffer collateral synapses in the CA1 region of hippocampal slices prepared from juvenile animals exposed to betamethasone or vehicle, in utero. Subsequently, the acute glucocorticoid receptor (GR)- and mineralocorticoid receptor (MR)-dependent effects of cortisol (0.1-10 microM; bath applied 30 min before LTP induction) were examined. There was no effect of prenatal sGC treatment on LTP under basal conditions. The application of 10 microM cortisol depressed excitatory synaptic transmission in all treatment groups regardless of sex. Similarly, LTP was depressed by 10 microM cortisol in all groups, with the exception of Beta-exposed females, in which LTP was unaltered. Hippocampal MR and GR protein levels were increased in Beta-exposed females, but not in any other prenatal treatment group. This study reveals sex-specific effects of prenatal exposure to sGC on LTP in the presence of elevated cortisol, a situation that would occur in vivo during stress.

  13. Quantification of print, radio and television exposure among previous blood donors in Kenya: an opportunity for encouraging repeat donation in a resource-limited setting?

    Science.gov (United States)

    Basavaraju, S V; Mwangi, J; Kellogg, T A; Odawo, L; Marum, L H

    2010-10-01

    Blood services in sub-Saharan Africa experience blood shortages and low retention of voluntary, non-remunerated donors. To boost collections by encouraging repeat donations, the Kenya National Blood Transfusion Service is exploring the likelihood of reaching previous donors through targeted print, radio and television advertising. We analysed data from a national AIDS Indicator Survey to determine whether previous donors have significant exposure to media. Respondents reporting history of blood donation had significantly higher exposure to print, radio and television media than those without history of blood donation. Targeted media campaigns encouraging repeat donation are likely to reach previous donors even in resource-limited settings.

  14. Smoke Exposure Causes Endoplasmic Reticulum Stress and Lipid Accumulation in Retinal Pigment Epithelium through Oxidative Stress and Complement Activation*

    Science.gov (United States)

    Kunchithapautham, Kannan; Atkinson, Carl; Rohrer, Bärbel

    2014-01-01

    Age-related macular degeneration (AMD) is a complex disease caused by genetic and environmental factors, including genetic variants in complement components and smoking. Smoke exposure leads to oxidative stress, complement activation, endoplasmic reticulum (ER) stress, and lipid dysregulation, which have all been proposed to be associated with AMD pathogenesis. Here we examine the effects of smoke exposure on the retinal pigment epithelium (RPE). Mice were exposed to cigarette smoke or filtered air for 6 months. RPE cells grown as stable monolayers were exposed to 5% cigarette smoke extract (CSE). Effects of smoke were determined by biochemical, molecular, and histological measures. Effects of the alternative pathway (AP) of complement and complement C3a anaphylatoxin receptor signaling were analyzed using knock-out mice or specific inhibitors. ER stress markers were elevated after smoke exposure in RPE of intact mice, which was eliminated in AP-deficient mice. To examine this relationship further, RPE monolayers were exposed to CSE. Short term smoke exposure resulted in production and release of complement C3, the generation of C3a, oxidative stress, complement activation on the cell membrane, and ER stress. Long term exposure to CSE resulted in lipid accumulation, and secretion. All measures were reversed by blocking C3a complement receptor (C3aR), alternative complement pathway signaling, and antioxidant therapy. Taken together, our results provide clear evidence that smoke exposure results in oxidative stress and complement activation via the AP, resulting in ER stress-mediated lipid accumulation, and further suggesting that oxidative stress and complement act synergistically in the pathogenesis of AMD. PMID:24711457

  15. 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.

  16. Endangered North Atlantic right whales (Eubalaena glacialis) experience repeated, concurrent exposure to multiple environmental neurotoxins produced by marine algae.

    Science.gov (United States)

    Doucette, Gregory J; Mikulski, Christina M; King, Kristen L; Roth, Patricia B; Wang, Zhihong; Leandro, Luis F; DeGrasse, Stacey L; White, Kevin D; De Biase, Daniela; Gillett, Roxanne M; Rolland, Rosalind M

    2012-01-01

    The western North Atlantic population of right whales (Eubalaena glacialis) is one of the most critically endangered of any whale population in the world. Among the factors considered to have potentially adverse effects on the health and reproduction of E. glacialis are biotoxins produced by certain microalgae responsible for causing harmful algal blooms. The worldwide incidence of these events has continued to increase dramatically over the past several decades and is expected to remain problematic under predicted climate change scenarios. Previous investigations have demonstrated that N. Atlantic right whales are being exposed to at least two classes of algal-produced environmental neurotoxins-paralytic shellfish toxins (PSTs) and domoic acid (DA). Our primary aims during this six-year study (2001-2006) were to assess whether the whales' exposure to these algal biotoxins occurred annually over multiple years, and to what extent individual whales were exposed repeatedly and/or concurrently to one or both toxin classes. Approximately 140 right whale fecal samples obtained across multiple habitats in the western N. Atlantic were analyzed for PSTs and DA. About 40% of these samples were attributed to individual whales in the North Atlantic Right Whale Catalog, permitting analysis of biotoxin exposure according to sex, age class, and reproductive status/history. Our findings demonstrate clearly that right whales are being exposed to both of these algal biotoxins on virtually an annual basis in multiple habitats for periods of up to six months (April through September), with similar exposure rates for females and males (PSTs: ∼70-80%; DA: ∼25-30%). Notably, only one of 14 lactating females sampled did not contain either PSTs or DA, suggesting the potential for maternal toxin transfer and possible effects on neonatal animals. Moreover, 22% of the fecal samples tested for PSTs and DA showed concurrent exposure to both neurotoxins, leading to questions of interactive

  17. A longitudinal study of atrazine and 2,4-D exposure and oxidative stress markers among iowa corn farmers.

    Science.gov (United States)

    Lerro, Catherine C; Beane Freeman, Laura E; Portengen, Lützen; Kang, Daehee; Lee, Kyoungho; Blair, Aaron; Lynch, Charles F; Bakke, Berit; De Roos, Anneclaire J; Vermeulen, Roel C H

    2017-01-01

    Reactive oxygen species, potentially formed through environmental exposures, can overwhelm an organism's antioxidant capabilities resulting in oxidative stress. Long-term oxidative stress is linked with chronic diseases. Pesticide exposures have been shown to cause oxidative stress in vivo. We utilized a longitudinal study of corn farmers and non-farming controls in Iowa to examine the impact of exposure to the widely used herbicides atrazine and 2,4-dichlorophenoxyacetic acid (2,4-D) on markers of oxidative stress. 225 urine samples were collected during five agricultural time periods (pre-planting, planting, growing, harvest, off-season) for 30 farmers who applied pesticides occupationally and 10 controls who did not; all were non-smoking men ages 40-60. Atrazine mercapturate (atrazine metabolite), 2,4-D, and oxidative stress markers (malondialdehyde [MDA], 8-hydroxy-2'-deoxyguanosine [8-OHdG], and 8-isoprostaglandin-F2α [8-isoPGF]) were measured in urine. We calculated β estimates and 95% confidence intervals (95%CI) for each pesticide-oxidative stress marker combination using multivariate linear mixed-effect models for repeated measures. Farmers had higher urinary atrazine mercapturate and 2,4-D levels compared with controls. In regression models, after natural log transformation, 2,4-D was associated with elevated levels of 8-OHdG (β = 0.066, 95%CI = 0.008-0.124) and 8-isoPGF (β = 0.088, 95%CI = 0.004-0.172). 2,4-D may be associated with oxidative stress because of modest increases in 8-OHdG, a marker of oxidative DNA damage, and 8-isoPGF, a product of lipoprotein peroxidation, with recent 2,4-D exposure. Future studies should investigate the role of 2,4-D-induced oxidative stress in the pathogenesis of human diseases. Environ. Mol. Mutagen. 58:30-38, 2017. © 2016 Wiley Periodicals, Inc.

  18. Virtual reality exposure therapy for post-traumatic stress disorder and other anxiety disorders.

    Science.gov (United States)

    Gerardi, Maryrose; Cukor, Judith; Difede, Joann; Rizzo, Albert; Rothbaum, Barbara Olasov

    2010-08-01

    Anxiety disorders, including phobias and post-traumatic stress disorder, are common and disabling disorders that often involve avoidance behavior. Cognitive-behavioral treatments, specifically imaginal and in vivo forms of exposure therapy, have been accepted and successful forms of treatment for these disorders. Virtual reality exposure therapy, an alternative to more traditional exposure-based therapies, involves immersion in a computer-generated virtual environment that minimizes avoidance and facilitates emotional processing. In this article, we review evidence on the application of virtual reality exposure therapy to the treatment of specific phobias and post-traumatic stress disorder and discuss its advantages and cautions.

  19. Prevention of diabetes in NOD mice by repeated exposures to a contact allergen inducing a sub-clinical dermatitis.

    Directory of Open Access Journals (Sweden)

    Kaare Engkilde

    Full Text Available BACKGROUND: 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 diseases. METHOD: NOD mice 4 weeks of age were exposed, on the ears, to two allergens, p-phenylenediamine and 2,4-dinitrochlorobenzene respectively, to investigate the diabetes development. The mice were followed for a maximum of 32 weeks, and they were either repeatedly exposed to the allergens or only sensitized a week after arrival. The stimulation of NKT cells by the two allergens were additionally studied in C57BL/6 mice. The mice were sensitized and two weeks later provocated with the allergens. The mice were subsequently euthanized at different time points after the provocation. RESULTS: It was found that repeated application of p-phenylenediamine reduced the incidence of diabetes compared to application with water (47% vs. 93%, P = 0.004. Moreover it was shown that in C57BL/6 mice both allergens resulted in a slight increment in the quantity of NKT cells in the liver. Application of the allergens at the same time resulted in an increased number of NKT cells in the draining auricular lymph node, and the increase appeared to be somewhat allergen specific as the accumulation was stronger for p-phenylenediamine. CONCLUSION: The study showed that repeated topical application on the ears with a contact allergen could prevent the development of diabetes in NOD mice. The contact allergens gave a non-visible, sub-clinical dermatitis on the

  20. Prevention of Diabetes in NOD Mice by Repeated Exposures to a Contact Allergen Inducing a Sub-Clinical Dermatitis

    Science.gov (United States)

    Engkilde, Kaare; Buschard, Karsten; Hansen, Axel Kornerup; Menné, Torkil; Johansen, Jeanne Duus

    2010-01-01

    Background Type 1 diabetes is an autoimmune disease, while allergic contact dermatitis although immune mediated, is considered an exposure driven disease that develops due to epicutanous 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 diseases. Method NOD mice 4 weeks of age were exposed, on the ears, to two allergens, p-phenylenediamine and 2,4-dinitrochlorobenzene respectively, to investigate the diabetes development. The mice were followed for a maximum of 32 weeks, and they were either repeatedly exposed to the allergens or only sensitized a week after arrival. The stimulation of NKT cells by the two allergens were additionally studied in C57BL/6 mice. The mice were sensitized and two weeks later provocated with the allergens. The mice were subsequently euthanized at different time points after the provocation. Results It was found that repeated application of p-phenylenediamine reduced the incidence of diabetes compared to application with water (47% vs. 93%, P = 0.004). Moreover it was shown that in C57BL/6 mice both allergens resulted in a slight increment in the quantity of NKT cells in the liver. Application of the allergens at the same time resulted in an increased number of NKT cells in the draining auricular lymph node, and the increase appeared to be somewhat allergen specific as the accumulation was stronger for p-phenylenediamine. Conclusion The study showed that repeated topical application on the ears with a contact allergen could prevent the development of diabetes in NOD mice. The contact allergens gave a non-visible, sub-clinical dermatitis on the application site. The

  1. Treating Posttraumatic Stress Disorder in Female Victims of Trafficking Using Narrative Exposure Therapy: A Retrospective Audit.

    Science.gov (United States)

    Robjant, Katy; Roberts, Jackie; Katona, Cornelius

    2017-01-01

    Human trafficking is a form of modern slavery that involves the forced movement of people internally within countries, or externally across borders. Victims who are trafficked for sexual exploitation are subject to repeated, multiple trauma, and high rates of mental health problems including posttraumatic stress disorder (PTSD) have been found. Narrative exposure therapy (NET) is an evidence-based treatment for PTSD. In this retrospective audit, we record the results of NET to treat 10 women who had been trafficked for sexual exploitation who were diagnosed with PTSD. All 10 women completed the therapy and experienced a reduction in PTSD severity scores at posttreatment, with improvements that were maintained or further improved at 3-month follow-up. General distress was also significantly reduced following treatment. Although limited by sample size and retrospective design, this audit demonstrates that NET is a feasible treatment for PTSD in this population and warrants further evaluation in a randomized controlled trial. Further adjunctive interventions may also be necessary to treat the additional psychological problems experienced by this population.

  2. Treating Posttraumatic Stress Disorder in Female Victims of Trafficking Using Narrative Exposure Therapy: A Retrospective Audit

    Directory of Open Access Journals (Sweden)

    Katy Robjant

    2017-06-01

    Full Text Available BackgroundHuman trafficking is a form of modern slavery that involves the forced movement of people internally within countries, or externally across borders. Victims who are trafficked for sexual exploitation are subject to repeated, multiple trauma, and high rates of mental health problems including posttraumatic stress disorder (PTSD have been found. Narrative exposure therapy (NET is an evidence-based treatment for PTSD.MethodsIn this retrospective audit, we record the results of NET to treat 10 women who had been trafficked for sexual exploitation who were diagnosed with PTSD.ResultsAll 10 women completed the therapy and experienced a reduction in PTSD severity scores at posttreatment, with improvements that were maintained or further improved at 3-month follow-up. General distress was also significantly reduced following treatment.ConclusionAlthough limited by sample size and retrospective design, this audit demonstrates that NET is a feasible treatment for PTSD in this population and warrants further evaluation in a randomized controlled trial. Further adjunctive interventions may also be necessary to treat the additional psychological problems experienced by this population.

  3. Stress Levels of Agricultural Science Cooperating Teachers and Student Teachers: A Repeated Measures Comparative Assessment

    Science.gov (United States)

    McKim, Billy R.; Rayfield, John; Harlin, Julie; Adams, Andy

    2013-01-01

    This study compared job stress levels of Texas agricultural science cooperating teachers and Texas agricultural science student teachers across a semester. The research objectives included describing secondary agricultural science cooperating teachers and student teachers perceptions of stressors, by time of semester (beginning, middle, and end),…

  4. Plasma catecholamine, corticosterone and glucose responses to repeated stress in rats : Effect of interstressor interval length

    NARCIS (Netherlands)

    de Boer, S.F.; Koopmans, S.J.; Slangen, J L; Van der Gugten, J

    1990-01-01

    Plasma noradrenaline (NA), adrenaline (A), corticosterone (CS) and glucose concentrations were determined in blood frequently sampled via a cardiac catheter from freely behaving rats exposed to five successive trials of water-immersion stress (WIS) with an interval between successive trials (interst

  5. Environmental heat stress modulates thyroid status and its response to repeated endotoxin (LPS) challenge in steers

    Science.gov (United States)

    Thyroid hormones are important in the adaptation to heat stress, allowing the adjustment of metabolic rates in favor of decreased energy utilization and heat production. Thyroid status is compromised in a variety of acute and chronic infections and toxin-mediated disease states. Our objective was to...

  6. Repeated measures of inflammation and oxidative stress biomarkers in preeclamptic and normotensive pregnancies.

    Science.gov (United States)

    Ferguson, Kelly K; Meeker, John D; McElrath, Thomas F; Mukherjee, Bhramar; Cantonwine, David E

    2017-05-01

    Preeclampsia is a prevalent and enigmatic disease, in part characterized by poor remodeling of the spiral arteries. However, preeclampsia does not always clinically present when remodeling has failed to occur. Hypotheses surrounding the "second hit" that is necessary for the clinical presentation of the disease focus on maternal inflammation and oxidative stress. Yet, the studies to date that have investigated these factors have used cross-sectional study designs or small study populations. In the present study, we sought to explore longitudinal trajectories, beginning early in gestation, of a panel of inflammation and oxidative stress markers in women who went on to have preeclamptic or normotensive pregnancies. We examined 441 subjects from the ongoing LIFECODES prospective birth cohort, which included 50 mothers who experienced preeclampsia and 391 mothers with normotensive pregnancies. Participants provided urine and plasma samples at 4 time points during gestation (median, 10, 18, 26, and 35 weeks) that were analyzed for a panel of oxidative stress and inflammation markers. Oxidative stress biomarkers included 8-isoprostane and 8-hydroxydeoxyguanosine. Inflammation biomarkers included C-reactive protein, the cytokines interleukin-1β, -6, and -10, and tumor necrosis factor-α. We created Cox proportional hazard models to calculate hazard ratios based on time of preeclampsia diagnosis in association with biomarker concentrations at each of the 4 study visits. In adjusted models, hazard ratios of preeclampsia were significantly (Pinflammation biomarkers that were measured at visit 2 (median, 18 weeks; hazard ratios, 1.31-1.83, in association with an interquartile range increase in biomarker). Hazard ratios at this time point were the most elevated for C-reactive protein, for interleukin-1β, -6, and -10, and for the oxidative stress biomarker 8-isoprostane (hazard ratio, 1.68; 95% confidence interval, 1.14-2.48) compared to other time points. Hazard ratios for

  7. AN EVALUATION OF OZONE EXPOSURE METRICS FOR A SEASONALLY DROUGHT STRESSED PONDEROSA PINE ECOSYSTEM. (R826601)

    Science.gov (United States)

    Ozone stress has become an increasingly significant factor in cases of forest decline reported throughout the world. Current metrics to estimate ozone exposure for forest trees are derived from atmospheric concentrations and assume that the forest is physiologically active at ...

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

    Science.gov (United States)

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

  9. Inhibition of voltage-gated calcium channels after subchronic and repeated exposure of PC12 cells to different classes of insecticides

    NARCIS (Netherlands)

    Meijer, Marieke; Brandsema, Joske A R; Nieuwenhuis, Desirée; Wijnolts, Fiona M J; Dingemans, Milou M L; Westerink, Remco H S

    2015-01-01

    We previously demonstrated that acute inhibition of voltage-gated calcium channels (VGCCs) is a common mode of action for (sub)micromolar concentrations of chemicals, including insecticides. However, since human exposure to chemicals is usually chronic and repeated, we investigated if selected insec

  10. Inhibition of voltage-gated calcium channels after subchronic and repeated exposure of PC12 cells to different classes of insecticides

    NARCIS (Netherlands)

    Meijer, Marieke; Brandsema, Joske A R; Nieuwenhuis, Desirée; Wijnolts, Fiona M J; Dingemans, Milou M L|info:eu-repo/dai/nl/304834564; Westerink, Remco H S|info:eu-repo/dai/nl/239425952

    2015-01-01

    We previously demonstrated that acute inhibition of voltage-gated calcium channels (VGCCs) is a common mode of action for (sub)micromolar concentrations of chemicals, including insecticides. However, since human exposure to chemicals is usually chronic and repeated, we investigated if selected insec

  11. Ammonia exposure induces oxidative stress, endoplasmic reticulum stress and apoptosis in hepatopancreas of pacific white shrimp (Litopenaeus vannamei).

    Science.gov (United States)

    Liang, Zhongxiu; Liu, Rui; Zhao, Depeng; Wang, Lingling; Sun, Mingzhe; Wang, Mengqiang; Song, Linsheng

    2016-07-01

    Ammonia is one of major environmental pollutants in the aquatic system that poses a great threat to the survival of shrimp. In the present study, the mRNA expression of endoplasmic reticulum (ER) stress marker and unfolded protein response (UPR) related genes, as well as the change of redox enzyme and apoptosis were investigated in hepatopancreas of the pacific white shrimp, Litopenaeus vannamei after the exposure of 20 mg L(-1) total ammonia nitrogen (TAN). Compared with the control group, the superoxide dismutase (SOD) activity in hepatopancreas decreased significantly (p vannamei after exposure to ammonia by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. The results indicated that ammonia exposure could induce oxidative stress, which further caused ER stress and apoptosis in hepatopancreas of L. vannamei.

  12. Modulatory influence of rarely repeated of immobilization episodes on the interleukin-1β-dependent reaction of blood leukocytes and hepatoprotective effect of restraint stress.

    Science.gov (United States)

    Tseilikman, O B; Tseilikman, V E; Linin, A V; Gubkin, D A; Rudina, E A; Trubetskoy, S A; Ivanov, P V; Pozdnyakov, E A

    2011-02-01

    Repeated episodes of 1-h restraint stress were accompanied by a decrease in the sensitivity of blood leukocytes and cytochrome P450-dependent monooxygenases of the liver to recombinant IL-1β. These changes are associated with the anti-inflammatory hepatoprotective effect of chronic stress.

  13. To explore relationships between physiological stress signals and stress behaviors in preterm infants during periods of exposure to environmental stress in the hospital.

    Science.gov (United States)

    Peng, Niang-Huei; Chen, Chao-Huei; Bachman, Jean; Lin, Hong-Chin; Wang, Teh-Ming; Chang, Yue-Cune; Chang, Yu-Shan

    2011-10-01

    The purpose of this exploratory descriptive study was to examine relationships among physiological stress signals (heart rate (HR), respiratory rate (RR), and oxygen saturation) and stress behaviors (6 stress behaviors related to sleep-wake states, 10 self-regulatory behaviors, and 17 behavioral stress cues) in preterm infants during periods of environmental stress. This research used a prospective repeated-measures design in a convenience sample of preterm infants of equations were used to determine relationships. Variables were measured every 2 min over 4 hr, for a total of 4,164 observations in 37 preterm infants. There were statistically significant relationships between 9 stress behavioral responses and changes in HR (seven stress behaviors and two self-regulatory behaviors; p stress behavioral responses and changes in RR (seven stress behaviors and two self-regulatory behaviors; p stress behavioral responses and changes in oxygen saturation (seven stress behaviors and four self-regulatory behaviors; p stress are related to physiological stress signals. However, results should be investigated further in larger samples.

  14. Escitalopram or novel herbal mixture treatments during or following exposure to stress reduce anxiety-like behavior through corticosterone and BDNF modifications.

    Directory of Open Access Journals (Sweden)

    Ravid Doron

    Full Text Available Anxiety disorders are a major public health concern worldwide. Studies indicate that repeated exposure to adverse experiences early in life can lead to anxiety disorders in adulthood. Current treatments for anxiety disorders are characterized by a low success rate and are associated with a wide variety of side effects. The aim of the present study was to evaluate the anxiolytic effects of a novel herbal treatment, in comparison to treatment with the selective serotonin reuptake inhibitor escitalopram. We recently demonstrated the anxiolytic effects of these treatments in BALB mice previously exposed to one week of stress. In the present study, ICR mice were exposed to post natal maternal separation and to 4 weeks of unpredictable chronic mild stress in adolescence, and treated during or following exposure to stress with the novel herbal treatment or with escitalopram. Anxiety-like behavior was evaluated in the elevated plus maze. Blood corticosterone levels were evaluated using radioimmunoassay. Brain derived neurotrophic factor levels in the hippocampus were evaluated using enzyme-linked immunosorbent assay. We found that (1 exposure to stress in childhood and adolescence increased anxiety-like behavior in adulthood; (2 the herbal treatment reduced anxiety-like behavior, both when treated during or following exposure to stress; (3 blood corticosterone levels were reduced following treatment with the herbal treatment or escitalopram, when treated during or following exposure to stress; (4 brain derived neurotrophic factor levels in the hippocampus of mice treated with the herbal treatment or escitalopram were increased, when treated either during or following exposure to stress. This study expands our previous findings and further points to the proposed herbal compound's potential to be highly efficacious in treating anxiety disorders in humans.

  15. Electric signal emissions during repeated abrupt uniaxial compressional stress steps in amphibolite from KTB drilling

    Directory of Open Access Journals (Sweden)

    D. Triantis

    2007-01-01

    Full Text Available Laboratory experiments have confirmed that the application of uniaxial stress on rock samples is accompanied by the production of weak electric currents, to which the term Pressure Stimulated Currents – PSC has been attributed. In this work the PSC emissions in amphibolite samples from KTB drilling are presented and commented upon. After having applied sequential loading and unloading cycles on the amphibolite samples, it was ascertained that in every new loading cycle after unloading, the emitted PSC exhibits lower peaks. This attitude of the current peaks is consistent with the acoustic emissions phenomena, and in this work is verified for PSC emissions during loading – unloading procedures. Consequently, the evaluation of such signals can help to correlate the state and the remaining strength of the sample with respect to the history of its mechanical stress.

  16. Effects of Repeated Acute Stress in Obese and Non-Obese Rats

    Science.gov (United States)

    2008-04-02

    levels in the body. The effects of a dysregulated stress responses and, in particular, elevated cortisol levels are evident in the brain and...has a mutated leptin receptor gene (Duclos et aI., 2005). This gene produces the hormone leptin which is expressed in adipose tissue (Kandel...and to greater adipose tissue in diet-induced obese rats (Levin & Dunn-Meynell, 2000). Other methods to induce obesity in animals include I IU t

  17. Microstructural Evolution and Residual Stresses of Air-Plasma Sprayed Thermal Barrier Coatings Under Thermal Exposure

    Science.gov (United States)

    Kwon, Jae-Young; Kim, Jae-Hyoun; Lee, Sang-Yeop; Jung, Yeon-Gil; Cho, Hyun; Yi, Dong-Kee; Paik, Ungyu

    Microstructural evolution and fracture behavior of zirconia (ZrO2)-based thermal barrier coatings (TBCs) were investigated under thermal exposure. New ZrO2 granule with 8 wt.% yttria (Y2O3) with a deformed hollow morphology was developed through a spray drying process and employed to prepare TBCs. The thermal exposure tests were conducted at 1210°C with a dwell time of 100 h till 800 h. The residual stress at the interface between top coat and thermally grown oxide (TGO) layer was measured using a nanoindentation technique before and after thermal exposure. Vertical cracks on the top coat were newly formed and interlamellar cracks at the interface were enhanced after the thermal exposure of 800 h. Especially, partial delamination was observed at the interface after the thermal exposure of 800 h in TBC samples tested. The microstructural evolution in the top coat could be defined through load-displacement curves, showing a higher load or a less displacement after the thermal exposure of 800 h. The stress state was strongly dependent on the TGO geometry, resulting in the compressive stresses at the "valleys" or the "troughs," and the tensile stresses at the "crests" or peak areas, in the ranges of -500 to -75 MPa and of +168 to + 24 MPa, respectively. These stress terms incorporated with resintering during thermal exposure affected the mechanical properties such as hardness and elastic modulus of the top coat.

  18. Exposure to prenatal stress has deleterious effects on hippocampal function in a febrile seizure rat model.

    Science.gov (United States)

    Qulu, Lihle; Daniels, W M U; Mabandla, Musa V

    2015-10-22

    Prenatal stress has been shown to result in the development of a number of neurological disorders in the offspring. Most of these disorders are a result of an altered HPA axis resulting in higher than normal glucocorticoid levels in the affected neonate. This leaves the offspring prone to immune challenges. Therefore the aim of the present study was to investigate the effects of prenatal stress and febrile seizures on behavior and hippocampal function. Pregnant dams were exposed to restraint stress during the third trimester. Following birth, febrile seizures were induced in two week old pups using lipopolysaccharide and kainic acid. A week later, anxiety-like behavior and navigational ability was assessed. Trunk blood was used to measure basal corticosterone concentration and hippocampal tissue was collected and analyzed. Our results show that exposure to prenatal stress increased basal corticosterone concentration. Exposure to prenatal stress exacerbated anxiety-like behavior and impaired the rat's navigational ability. Exposure to prenatal stress resulted in reduced hippocampal mass that was exacerbated by febrile seizures. However, exposure to febrile seizures did not affect hippocampal mass in the absence of prenatal stress. This suggests that febrile seizures are exacerbated by exposure to early life stressors and this may lead to the development of neurological symptoms associated with a malfunctioning hippocampus. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Effects of prenatal exposure to chronic mild stress and toluene in rats

    DEFF Research Database (Denmark)

    Hougaard, Karin; Andersen, Maibritt B; Hansen, Ase M;

    2005-01-01

    The aim of the present study was to elucidate whether prenatal chronic stress, in combination with exposure to a developmental neurotoxicant, would increase effects in the offspring compared with the effects of either exposure alone. Development and neurobehavioral effects were investigated in fe...

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

    Science.gov (United States)

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

    2012-06-01

    Previously, we reported that acute treatment with propoxur or carbaryl decreased the duration of the photic after discharge (PhAD) of flash evoked potentials (FEPs). In the current studies, we compared the effects of acute or repeated exposure to a mixture of carbaryl and propoxur (1:1.45 ratio; propoxur:carbaryl) on the duration of the PhAD and brain ChE activity in Long Evans rats. Animals were exposed (po) either to a single dose (0, 3, 10, 45 or 75 mg/kg), or 14 daily dosages (0, 3, 10, 30, 45 mg/kg), of the mixture. Acute and repeated treatment with 3mg/kg (or greater) of the mixture produced dose-related inhibition of brain ChE activity. Compared to controls, the PhAD duration decreased after acute administration of 75 mg/kg or repeated treatment with 30 mg/kg of the mixture. The linear relationship between the percent of control brain ChE activity and the PhAD duration was similar for both exposure paradigms. Dose-response models for the acute and repeated exposure data did not differ for brain ChE activity or the duration of the PhAD. Repeated treatment with the mixture resulted in slightly less (13-22%) erythrocyte ChE inhibition than acute exposure. Both acute and repeated treatment resulted in dose-additive results for the PhAD duration and less than dose-additive responses (6-16%) for brain ChE activity for the middle range of dosages. Acute treatment resulted in greater than dose-additive erythrocyte ChE inhibition (15-18%) at the highest dosages. In contrast, repeated treatment resulted in less than dose-additive erythrocyte ChE inhibition (16-22%) at the middle dosages. Brain and plasma levels of propoxur and carbaryl did not differ between the acute and repeated dosing paradigms. In summary, a physiological measure of central nervous system function and brain ChE activity had similar responses after acute or repeated treatment with the carbamate mixture, and brain ChE showed only small deviations from dose-additivity. Erythrocyte ChE activity had

  1. Exogenous prenatal corticosterone exposure mimics the effects of prenatal stress on adult brain stress response systems and fear extinction behavior.

    Science.gov (United States)

    Bingham, Brian C; Sheela Rani, C S; Frazer, Alan; Strong, Randy; Morilak, David A

    2013-11-01

    Exposure to early-life stress is a risk factor for the development of cognitive and emotional disorders later in life. We previously demonstrated that prenatal stress (PNS) in rats results in long-term, stable changes in central stress-response systems and impairs the ability to extinguish conditioned fear responding, a component of post-traumatic stress disorder (PTSD). Maternal corticosterone (CORT), released during prenatal stress, is a possible mediator of these effects. The purpose of the present study was to investigate whether fetal exposure to CORT at levels induced by PNS is sufficient to alter the development of adult stress neurobiology and fear extinction behavior. Pregnant dams were subject to either PNS (60 min immobilization/day from ED 14-21) or a daily injection of CORT (10mg/kg), which approximated both fetal and maternal plasma CORT levels elicited during PNS. Control dams were given injections of oil vehicle. Male offspring were allowed to grow to adulthood undisturbed, at which point they were sacrificed and the medial prefrontal cortex (mPFC), hippocampus, hypothalamus, and a section of the rostral pons containing the locus coeruleus (LC) were dissected. PNS and prenatal CORT treatment decreased glucocorticoid receptor protein levels in the mPFC, hippocampus, and hypothalamus when compared to control offspring. Both treatments also decreased tyrosine hydroxylase levels in the LC. Finally, the effect of prenatal CORT exposure on fear extinction behavior was examined following chronic stress. Prenatal CORT impaired both acquisition and recall of cue-conditioned fear extinction. This effect was additive to the impairment induced by previous chronic stress. Thus, these data suggest that fetal exposure to high levels of maternal CORT is responsible for many of the lasting neurobiological consequences of PNS as they relate to the processes underlying extinction of learned fear. The data further suggest that adverse prenatal environments constitute a

  2. Central serotonin depletion modulates the behavioural, endocrine and physiological responses to repeated social stress and subsequent c-fos expression in the brains of male rats.

    Science.gov (United States)

    Chung, K K; Martinez, M; Herbert, J

    1999-01-01

    Intraspecific confrontation has been used to study effect of depleting central serotonin on the adaptation of male rats to repeated social stress (social defeat). Four groups of adult male rats were used (serotonin depletion/sham: stressed; serotonin depletion/sham: non-stressed). Central serotonin was reduced (by 59-97%) by a single infusion of the neurotoxin 5,7-dihydroxtryptamine (150 microg) into the cerebral ventricles; levels of dopamine and noradrenaline were unaltered (rats received appropriate uptake blockers prior to neurotoxic infusions). Sham-operated animals received solute only. Rats were then either exposed daily for 10 days to a second larger aggressive male in the latter's home cage, or simply transferred to an empty cage (control procedure). Rats with reduced serotonin failed to show the increased freezing behaviour during the pre-defeat phase of the social interaction test characteristic of sham animals. There was no change in the residents' behaviour. Core temperature increased during aggressive interaction in sham rats, and this did not adapt with repeated stress. By contrast, stress-induced hyperthermia was accentuated in serotonin-reduced rats as the number of defeat sessions increased. Basal core temperature was unaffected by serotonin depletion. Heart rate increased during social defeat, but this did not adapt with repeated stress; serotonin depletion had no effect on this cardiovascular response. Basal corticosterone was increased in serotonin-depleted rats, but the progressive reduction in stress response over days was not altered. C-fos expression in the brain was not altered in control (non-stressed) rats by serotonin reduction in the areas examined, but there was increased expression after repeated social stress in the medial amygdala of 5-HT depleted rats. These experiments show that reduction of serotonin alters responses to repeated social stress in male rats, and suggests a role for serotonin in the adaptive process.

  3. Loss of Sustained Activity in the Ventromedial Prefrontal Cortex in Response to Repeated Stress in Individuals with Early-Life Emotional Abuse: Implications for Depression Vulnerability

    Directory of Open Access Journals (Sweden)

    Lihong eWang

    2013-06-01

    Full Text Available Repeated psychosocial stress in early life has significant impact on both behavior and neural function which, together, increase vulnerability to depression. However, neural mechanisms related to repeated stress remain unclear. We hypothesize that early-life stress may result in a reduced capacity for cognitive control in response to a repeated stressor, particularly in individuals who developed maladaptive emotional processing strategies, namely trait rumination. Individuals who encountered early-life stress but have adaptive emotional processing, namely trait mindfulness, may demonstrate an opposite pattern. Using a mental arithmetic task to induce mild stress and a mindful breathing task to induce a mindful state, we tested this hypothesis by examining blood perfusion changes over time in healthy young men. We found that subjects with early-life stress, particularly emotional abuse, failed to sustain neural activation in the orbitofrontal and ventromedial prefrontal cortex (vmPFC over time. Given that the vmPFC is known to regulate amygdala activity during emotional processing, we subsequently compared the perfusion in the vmPFC and the amygdala in depression-vulnerable (having early life stress and high in rumination and resilient (having early life stress and high in mindfulness subjects. We found that depression-vulnerable subjects had increased amygdala perfusion and reduced vmPFC perfusion during the later runs than that during the earlier stressful task runs. In contrast, depression resilient individuals showed the reverse pattern. Our results indicate that the vmPFC of depression-vulnerable subjects may have a limited capacity to inhibit amygdala activation to repeated stress over time, whereas the vmPFC in resilient individuals may adapt to stress quickly. This pilot study warrants future investigation to clarify the stress-related neural activity pattern dynamically to identify depression vulnerability at an individual level.

  4. Conscientiousness and stress exposure and reactivity: a prospective study of adolescent females.

    Science.gov (United States)

    Murphy, Michael L M; Miller, Gregory E; Wrosch, Carsten

    2013-04-01

    Conscientiousness is associated with health, but the mechanisms remain poorly understood. To explore the role that stress might play, this study examined whether conscientiousness was associated with exposure and reactivity to life stress. This study followed 133 adolescent women every 6 months for 2.5 years. Participants completed a baseline measure of conscientiousness, and at each visit underwent a structured interview to catalogue episodic and chronic stress and had blood drawn to assess inflammatory processes. Participants higher in conscientiousness experienced fewer self-dependent episodic stressors and less academic and interpersonal chronic stress throughout the study. However, at times when they experienced higher levels of chronic interpersonal stress, they became more resistant to glucocorticoids. Higher levels of conscientiousness may protect adolescent women from exposure to certain stressors. However, when stress occurs, highly conscientious individuals may become more resistant to glucocorticoids, increasing their risk for processes that influence inflammatory conditions.

  5. Repeated Thermal Stress, Shading, and Directional Selection in the Florida Reef Tract

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    Robert van Woesik

    2017-06-01

    Full Text Available Over the last three decades reef corals have been subjected to an unprecedented frequency and intensity of thermal-stress events, which have led to extensive coral bleaching, disease, and mortality. Over the next century, the climate is predicted to drive sea-surface temperatures to even higher levels, consequently increasing the risk of mass bleaching and disease outbreaks. Yet, there is considerable temporal and spatial variation in coral bleaching and in disease prevalence. Using data collected from 2,398 sites along the Florida reef tract from 2005 to 2015, this study examined the temporal and spatial patterns of coral bleaching and disease in relation to coral-colony size, depth, temperature, and chlorophyll-a concentrations. The results show that coral bleaching was most prevalent during the warmest years in 2014 and 2015, and disease was also most prevalent in 2010, 2014, and 2015. Although the majority of the corals surveyed were found in habitats with low chlorophyll-a concentrations, and high irradiance, these same habitats showed the highest prevalence of coral bleaching and disease outbreaks during thermal-stress events. These results suggest that directional selection in a warming ocean may favor corals able to tolerate inshore, shaded environments with high turbidity and productivity.

  6. Comparison of exposure to stress and analysis of ways of coping with stress among freight transport and public transport drivers

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    Katarzyna Urbańska

    2016-08-01

    Full Text Available Background: Fast progress in a lot of economic sectors has greatly contributed to a growing role of road transportation systems, including freight transport and passenger transport. The job of professional drivers is regarded as extremely hard and dangerous, it is associated with high risk of health loss and even life loss. This profession is also associated with mental burden, the main cause of the absence at work and alarming number of road accidents. The aim of study was to compare exposure to stress, check the level of stress and ways to cope with stress in 2 groups of drivers (N = 187. Material and Methods: The study was carried out among public transport drivers and freight transport drivers. The authors’ own questionnaire and 2 psychological tests: Perceived Stress Scale (PSS-10 and Posttraumatic Growth Inventory and Inventory to Measure Coping Strategies with Stress (Mini-COPE were used as the study tools. Results: The level of stress is high in both groups, mostly due to a similar type of work. Both groups practice similar ways to cope with stress, but active ways predominate. Conclusions: The work of a professional driver is considered as extremely stressful. The level of stress among professional drivers should be under continuous control. Employers should introduce preventive programs and educate employees about some professional ways to cope with stress. Med Pr 2016;67(4:455–466

  7. Mother knows best, even when stressed? Effects of maternal exposure to a stressor on offspring performance at different life stages in a wild semelparous fish.

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    Sopinka, N M; Hinch, S G; Middleton, C T; Hills, J A; Patterson, D A

    2014-06-01

    The environment mothers are exposed to has resonating effects on offspring performance. In iteroparous species, maternal exposure to stressors generally results in offspring ill-equipped for survival. Still, opportunities for future fecundity can offset low quality offspring. Little is known, however, as to how intergenerational effects of stress manifest in semelparous species with only a single breeding episode. Such mothers would suffer a total loss of fitness if offspring cannot survive past multiple life stages. We evaluated whether chronic exposure of female sockeye salmon (Oncorhynchus nerka) to a chase stressor impaired offspring performance traits. Egg size and early offspring survival were not influenced by maternal exposure to the repeated acute stressor. Later in development, fry reared from stressed mothers swam for shorter periods of time but possessed a superior capacity to re-initiate bouts of burst swimming. In contrast to iteroparous species, the mechanisms driving the observed effects do not appear to be related to cortisol, as egg hormone concentrations did not vary between stressed and undisturbed mothers. Sockeye salmon appear to possess buffering strategies that protect offspring from deleterious effects of maternal stress that would otherwise compromise progeny during highly vulnerable stages of development. Whether stressed sockeye salmon mothers endow offspring with traits that are matched or mismatched for survival in the unpredictable environment they encountered is discussed. This study highlights the importance of examining intergenerational effects among species-specific reproductive strategies, and across offspring life history to fully determine the scope of impact of maternal stress.

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

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    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.

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

    Science.gov (United States)

    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 AgNPs. Besides the intestinal system, the largest silver concentrations were detected in the liver and kidneys. Silver was also found in the lungs and brain. Autometallographic (AMG) staining revealed a similar cellular localization of silver in ileum, liver, and kidney tissue in rats exposed to AgNPs or AgAc. Using transmission electron microscopy (TEM), nanosized granules were detected in the ileum of animals exposed to AgNPs or AgAc and were mainly located in the basal lamina of the ileal epithelium and in lysosomes of macrophages within the lamina propria. Using energy dispersive x-ray spectroscopy it was shown that the granules in lysosomes consisted of silver, selenium, and sulfur for both AgNP and AgAc exposed rats. The diameter of the deposited granules was in the same size range as that of the administered AgNPs. No silver granules were detected by TEM in the liver. Conclusions The results of the present study demonstrate that the organ distribution of silver was similar when AgNPs or AgAc were administered orally to rats. The presence of silver granules containing

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

    Directory of Open Access Journals (Sweden)

    Mortensen Alicja

    2011-06-01

    Full Text Available Abstract 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 AgNPs. Besides the intestinal system, the largest silver concentrations were detected in the liver and kidneys. Silver was also found in the lungs and brain. Autometallographic (AMG staining revealed a similar cellular localization of silver in ileum, liver, and kidney tissue in rats exposed to AgNPs or AgAc. Using transmission electron microscopy (TEM, nanosized granules were detected in the ileum of animals exposed to AgNPs or AgAc and were mainly located in the basal lamina of the ileal epithelium and in lysosomes of macrophages within the lamina propria. Using energy dispersive x-ray spectroscopy it was shown that the granules in lysosomes consisted of silver, selenium, and sulfur for both AgNP and AgAc exposed rats. The diameter of the deposited granules was in the same size range as that of the administered AgNPs. No silver granules were detected by TEM in the liver. Conclusions The results of the present study demonstrate that the organ distribution of silver was similar when AgNPs or AgAc were administered orally to rats. The presence of silver

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

    Science.gov (United States)

    Loeschner, Katrin; Hadrup, Niels; Qvortrup, Klaus; Larsen, Agnete; Gao, Xueyun; Vogel, Ulla; Mortensen, Alicja; Lam, Henrik Rye; Larsen, Erik H

    2011-06-01

    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. 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 AgNPs. Besides the intestinal system, the largest silver concentrations were detected in the liver and kidneys. Silver was also found in the lungs and brain. Autometallographic (AMG) staining revealed a similar cellular localization of silver in ileum, liver, and kidney tissue in rats exposed to AgNPs or AgAc. Using transmission electron microscopy (TEM), nanosized granules were detected in the ileum of animals exposed to AgNPs or AgAc and were mainly located in the basal lamina of the ileal epithelium and in lysosomes of macrophages within the lamina propria. Using energy dispersive x-ray spectroscopy it was shown that the granules in lysosomes consisted of silver, selenium, and sulfur for both AgNP and AgAc exposed rats. The diameter of the deposited granules was in the same size range as that of the administered AgNPs. No silver granules were detected by TEM in the liver. The results of the present study demonstrate that the organ distribution of silver was similar when AgNPs or AgAc were administered orally to rats. The presence of silver granules containing selenium and sulfur in the

  12. A review of the reporting and handling of missing data in cohort studies with repeated assessment of exposure measures

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    Karahalios Amalia

    2012-07-01

    Full Text Available Abstract Background Retaining participants in cohort studies with multiple follow-up waves is difficult. Commonly, researchers are faced with the problem of missing data, which may introduce biased results as well as a loss of statistical power and precision. The STROBE guidelines von Elm et al. (Lancet, 370:1453-1457, 2007; Vandenbroucke et al. (PLoS Med, 4:e297, 2007 and the guidelines proposed by Sterne et al. (BMJ, 338:b2393, 2009 recommend that cohort studies report on the amount of missing data, the reasons for non-participation and non-response, and the method used to handle missing data in the analyses. We have conducted a review of publications from cohort studies in order to document the reporting of missing data for exposure measures and to describe the statistical methods used to account for the missing data. Methods A systematic search of English language papers published from January 2000 to December 2009 was carried out in PubMed. Prospective cohort studies with a sample size greater than 1,000 that analysed data using repeated measures of exposure were included. Results Among the 82 papers meeting the inclusion criteria, only 35 (43% reported the amount of missing data according to the suggested guidelines. Sixty-eight papers (83% described how they dealt with missing data in the analysis. Most of the papers excluded participants with missing data and performed a complete-case analysis (n = 54, 66%. Other papers used more sophisticated methods including multiple imputation (n = 5 or fully Bayesian modeling (n = 1. Methods known to produce biased results were also used, for example, Last Observation Carried Forward (n = 7, the missing indicator method (n = 1, and mean value substitution (n = 3. For the remaining 14 papers, the method used to handle missing data in the analysis was not stated. Conclusions This review highlights the inconsistent reporting of missing data in cohort studies and the continuing

  13. A review of the reporting and handling of missing data in cohort studies with repeated assessment of exposure measures.

    Science.gov (United States)

    Karahalios, Amalia; Baglietto, Laura; Carlin, John B; English, Dallas R; Simpson, Julie A

    2012-07-11

    Retaining participants in cohort studies with multiple follow-up waves is difficult. Commonly, researchers are faced with the problem of missing data, which may introduce biased results as well as a loss of statistical power and precision. The STROBE guidelines von Elm et al. (Lancet, 370:1453-1457, 2007); Vandenbroucke et al. (PLoS Med, 4:e297, 2007) and the guidelines proposed by Sterne et al. (BMJ, 338:b2393, 2009) recommend that cohort studies report on the amount of missing data, the reasons for non-participation and non-response, and the method used to handle missing data in the analyses. We have conducted a review of publications from cohort studies in order to document the reporting of missing data for exposure measures and to describe the statistical methods used to account for the missing data. A systematic search of English language papers published from January 2000 to December 2009 was carried out in PubMed. Prospective cohort studies with a sample size greater than 1,000 that analysed data using repeated measures of exposure were included. Among the 82 papers meeting the inclusion criteria, only 35 (43%) reported the amount of missing data according to the suggested guidelines. Sixty-eight papers (83%) described how they dealt with missing data in the analysis. Most of the papers excluded participants with missing data and performed a complete-case analysis (n=54, 66%). Other papers used more sophisticated methods including multiple imputation (n=5) or fully Bayesian modeling (n=1). Methods known to produce biased results were also used, for example, Last Observation Carried Forward (n=7), the missing indicator method (n=1), and mean value substitution (n=3). For the remaining 14 papers, the method used to handle missing data in the analysis was not stated. This review highlights the inconsistent reporting of missing data in cohort studies and the continuing use of inappropriate methods to handle missing data in the analysis. Epidemiological journals

  14. Protection Efficacy of the Extract of Ginkgo biloba against the Learning and Memory Damage of Rats under Repeated High Sustained +Gz Exposure

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    Liang-En Chen

    2016-01-01

    Full Text Available Repeated high sustained positive Gz (+Gz exposures are known for the harmful pathophysiological impact on the brain of rats, which is reflected as the interruption of normal performance of learning and memory. Interestingly, extract of Ginkgo biloba (EGb has been reported to have neuroprotective effects and cognition-enhancing effects. In this study, we are interested in evaluating the protective effects of EGb toward the learning and memory abilities. Morris Water Maze Test (MWM was used to evaluate the cognitive function, and the physiological status of the key components in central cholinergic system was also investigated. Our animal behavioral tests indicated that EGb can release the learning and memory impairment caused by repeated high sustained +Gz. Administration of EGb to rats can diminish some of the harmful physiological effects caused by repeated +Gz exposures. Moreover, EGb administration can increase the biological activities of superoxide dismutase (SOD and glutathione peroxidase (GSH-Px but reduce the production of malondialdehyde (MDA. Taken together, our study showed that EGb can ameliorate the impairment of learning and memory abilities of rats induced by repeated high sustained +Gz exposure; the underlying mechanisms appeared to be related to the signal regulation on the cholinergic system and antioxidant enzymes system.

  15. Physical exercise affects the epigenetic programming of rat brain and modulates the adaptive response evoked by repeated restraint stress.

    Science.gov (United States)

    Kashimoto, R K; Toffoli, L V; Manfredo, M H F; Volpini, V L; Martins-Pinge, M C; Pelosi, G G; Gomes, M V

    2016-01-01

    Epigenetics has recently been linked to molecular adaptive responses evoked by physical exercise and stress. Herein we evaluated the effects of physical exercise on global DNA methylation and expression of the Dnmt1 gene in the rat brain and also verified its potential to modulate responses evoked by repeated restraint stress (RRS). Wistar rats were classified into the following experimental groups: (1) physically active (EX): animals submitted to swimming during postnatal days 53-78 (PND); (2) stress (ST): animals submitted to RRS during 75-79PND; (3) exercise-stress (EX-ST): animals submitted to swimming during 53-78PND and to RRS during 75-79PND, and (4) control (CTL): animals that were not submitted to intervention. Samples from the hippocampus, cortex and hypothalamus were obtained at 79PND. The global DNA methylation profile was assessed using an ELISA-based method and the expression of Dnmt1 was evaluated by real-time PCR. Significantly increased methylation was observed in the hypothalamus of animals from the EX group in comparison to CTL. Comparative analysis involving the EX-ST and ST groups revealed increased global DNA methylation in the hippocampus, cortex, and hypothalamus of EX-ST, indicating the potential of physical exercise in modulating the responses evoked by RRS. Furthermore, decreased expression of the Dnmt1 gene was observed in the hippocampus and hypothalamus of animals from the EX-ST group. In summary, our data indicate that physical exercise affects DNA methylation of the hypothalamus and might modulate epigenetic responses evoked by RRS in the hippocampus, cortex, and hypothalamus. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Corticosterone stress response shows long-term repeatability and links to personality in free-living Nazca boobies.

    Science.gov (United States)

    Grace, Jacquelyn K; Anderson, David J

    2014-11-01

    The concept of "coping styles", or consistently different responses to stressors, is of broad interest in behavioral ecology and biomedicine. Two critical predictions of this concept are individual consistency of neurophysiological and behavioral responses (relative to population variability) and a negative relationship between aggression/proactivity and hypothalamic-pituitary-adrenal axis reactivity. Recent studies failed to provide strong support for these predictions, especially outside of strictly controlled conditions, and long-term measures to test the first prediction are rare. Here, we demonstrate individual repeatability across 2-3years of maximum circulating corticosterone concentration [CORT] and area under the [CORT] response curve (AUCI) during a standard capture-restraint test in wild, free-living adult Nazca boobies (Sula granti). We also show that the stress response predicts the personality traits aggression and anxiety in these birds (measured in the wild); however, the strength of these results was weak. Maximum [CORT] and AUCI showed higher repeatability between years than baseline [CORT]. After controlling breeding status, sex, mass, date sampled, and their interactions, baseline [CORT] was most closely related to personality traits, followed by AUCI, and then maximum [CORT]. The direction of these relationships depended on whether the testing context was social or non-social. [CORT] parameters had little to no relationship with cross-context plasticity in personality traits. Our results generally affirm two critical predictions of coping styles, but match the emerging trend that these relationships are weak in the wild, and may depend on testing context.

  17. Childhood trauma exposure and toxic stress: what the PNP needs to know.

    Science.gov (United States)

    Hornor, Gail

    2015-01-01

    Trauma exposure in childhood is a major public health problem that can result in lifelong mental and physical health consequences. Pediatric nurse practitioners must improve their skills in the identification of trauma exposure in children and their interventions with these children. This continuing education article will describe childhood trauma exposure (adverse childhood experiences) and toxic stress and their effects on the developing brain and body. Adverse childhood experiences include a unique set of trauma exposures. The adverse childhood experiences or trauma discussed in this continuing education offering will include childhood exposure to emotional abuse, physical abuse, sexual abuse, emotional neglect, physical neglect, domestic violence, household substance abuse, household mental illness, parental separation or divorce, and a criminal household member. Thorough and efficient methods of screening for trauma exposure will be discussed. Appropriate intervention after identification of trauma exposure will be explored.

  18. Evaluation of oxidative stress induction in rats following exposure to silver nanorods.

    Science.gov (United States)

    Lingabathula, Harikiran; Yellu, Narsimhareddy

    2017-01-25

    The study investigated the oxidative stress induction by the 10 and 25 nm silver nanorods (SNRs) following intra-tracheal instillation in rats after 1 day, 1 week, 1 month and 3 months post instillation periods at 1 and 5 mg/kg b.w. doses. The blood was withdrawn by retro orbital plexus method after exposure periods and different oxidative stress markers were estimated. The results showed that the both sizes of SNRs induced increased levels of malondialdehyde (MDA) and depleted glutathione (GSH) levels after 1 day and 1 week post exposure periods. The 10 and 25 nm SNRs at both doses displayed that significantly reduced levels of superoxide dismutase (SOD) and catalase following 1 day and 1 week post exposure periods. Also, the results have shown that decrease in total antioxidant capacity (TAC) of both sizes of SNRs significantly following 1 day and 1 week post exposure periods, indicating the oxidative stress induction by SNRs. In spite, there were no significant changes in oxidative stress markers following 1 month and 3 months post exposure periods may be due to recovery. The increased levels of MDA and decreased levels of GSH, SOD, catalase and TAC activity are strongly associated to ROS production and lipid peroxidation, suggesting the induction of oxidative stress in rats. The 10 nm SNRs at 5 mg/kg b.w. dose exposures in rats have shown greater changes in all oxidative stress parameters, indicating the greater induction of oxidative stress when compared with the 25 nm SNRs, representing the size-dose-dependent induction of oxidative stress of SNRs.

  19. Physiological Stress Responses to Prolonged Exposure to MS-222 and Surgical Implantation in Juvenile Chinook Salmon

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Katie A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Woodley, Christa M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Seaburg, Adam [Univ. of Washington, Seattle, WA (United States); Skalski, John R. [Univ. of Washington, Seattle, WA (United States); Eppard, Matthew B. [U.S. Army Corps of Engineers, Portland, OR (United States)

    2014-07-17

    While many studies have investigated the effects of transmitters on fish condition, behavior, and survival, to our knowledge, no studies have taken into account anesthetic exposure time in addition to tag and surgery effects. We investigated stress responses to prolonged MS-222 exposure after stage 4 induction in surgically implanted juvenile Chinook salmon (Oncorhynchus tshawytscha). Survival, tag loss, plasma cortisol concentration, and blood Na+, K+, Ca2+, and pH were measured immediately following anesthetic exposure and surgical implantation and 1, 7, and 14 days post-treatment. Despite the prolonged anesthetic exposure, 3-15 minutes post Stage 4 induction, there were no mortalities or tag loss in any treatment. MS-222 was effective at delaying immediate cortisol release during surgical implantation; however, osmotic disturbances resulted, which were more pronounced in longer anesthetic time exposures. From day 1 to day 14, Na+, Ca2+, and pH significantly decreased, while cortisol significantly increased. The cortisol increase was exacerbated by surgical implantation. There was a significant interaction between MS-222 time exposure and observation day for Na+, Ca2+, K+, and pH; variations were seen in the longer time exposures, although not consistently. In conclusion, stress response patterns suggest stress associated with surgical implantation is amplified with increased exposure to MS-222.

  20. Maternal serotonin transporter genotype affects risk for ASD with exposure to prenatal stress.

    Science.gov (United States)

    Hecht, Patrick M; Hudson, Melissa; Connors, Susan L; Tilley, Michael R; Liu, Xudong; Beversdorf, David Q

    2016-11-01

    Stress exposure during gestation is implicated in several neuropsychiatric conditions, including autism spectrum disorder (ASD). Previous research showed that prenatal stress increases risk for ASD with peak exposure during the end of the second and the beginning of the third trimester. However, exposures to prenatal stress do not always result in ASD, suggesting that other factors may interact with environmental stressors to increase ASD risk. The present study examined a maternal genetic variation in the promoter region of the serotonin transporter gene (5-HTTLPR) affecting stress tolerance and its interaction with the effect of environmental stressors on risk for ASD. Two independent cohorts of mothers of ASD children recruited by the University of Missouri and Queen's University were surveyed regarding the prenatal environment and genotyping on 5-HTTLPR was performed to explore this relationship. In both samples, mothers of children with ASD carrying the stress susceptible short allele variant of 5-HTTLPR experienced a greater number of stressors and greater stress severity when compared to mothers carrying the long allele variant. The temporal peak of stressors during gestation in these mothers was consistent with previous findings. Additionally, increased exposure to prenatal stress was not reported in the pregnancies of typically developing siblings from the same mothers, regardless of maternal genotype, suggesting against the possibility that the short allele might increase the recall of stress during pregnancy. The present study provides further evidence of a specific maternal polymorphism that may affect the risk for ASD with exposure to prenatal stress. Autism Res 2016, 9: 1151-1160. © 2016 International Society for Autism Research, Wiley Periodicals, Inc. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

  1. Montmorency cherries reduce the oxidative stress and inflammatory responses to repeated days high-intensity stochastic cycling.

    Science.gov (United States)

    Bell, Phillip G; Walshe, Ian H; Davison, Gareth W; Stevenson, Emma; Howatson, Glyn

    2014-02-21

    This investigation examined the impact of Montmorency tart cherry concentrate (MC) on physiological indices of oxidative stress, inflammation and muscle damage across 3 days simulated road cycle racing. Trained cyclists (n = 16) were divided into equal groups and consumed 30 mL of MC or placebo (PLA), twice per day for seven consecutive days. A simulated, high-intensity, stochastic road cycling trial, lasting 109 min, was completed on days 5, 6 and 7. Oxidative stress and inflammation were measured from blood samples collected at baseline and immediately pre- and post-trial on days 5, 6 and 7. Analyses for lipid hydroperoxides (LOOH), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), interleukin-8 (IL-8), interleukin-1-beta (IL-1-β), high-sensitivity C-reactive protein (hsCRP) and creatine kinase (CK) were conducted. LOOH (p < 0.01), IL-6 (p < 0.05) and hsCRP (p < 0.05) responses to trials were lower in the MC group versus PLA. No group or interaction effects were found for the other markers. The attenuated oxidative and inflammatory responses suggest MC may be efficacious in combating post-exercise oxidative and inflammatory cascades that can contribute to cellular disruption. Additionally, we demonstrate direct application for MC in repeated days cycling and conceivably other sporting scenario's where back-to-back performances are required.

  2. Montmorency Cherries Reduce the Oxidative Stress and Inflammatory Responses to Repeated Days High-Intensity Stochastic Cycling

    Directory of Open Access Journals (Sweden)

    Phillip G. Bell

    2014-02-01

    Full Text Available This investigation examined the impact of Montmorency tart cherry concentrate (MC on physiological indices of oxidative stress, inflammation and muscle damage across 3 days simulated road cycle racing. Trained cyclists (n = 16 were divided into equal groups and consumed 30 mL of MC or placebo (PLA, twice per day for seven consecutive days. A simulated, high-intensity, stochastic road cycling trial, lasting 109 min, was completed on days 5, 6 and 7. Oxidative stress and inflammation were measured from blood samples collected at baseline and immediately pre- and post-trial on days 5, 6 and 7. Analyses for lipid hydroperoxides (LOOH, interleukin-6 (IL-6, tumor necrosis factor-alpha (TNF-α, interleukin-8 (IL-8, interleukin-1-beta (IL-1-β, high-sensitivity C-reactive protein (hsCRP and creatine kinase (CK were conducted. LOOH (p < 0.01, IL-6 (p < 0.05 and hsCRP (p < 0.05 responses to trials were lower in the MC group versus PLA. No group or interaction effects were found for the other markers. The attenuated oxidative and inflammatory responses suggest MC may be efficacious in combating post-exercise oxidative and inflammatory cascades that can contribute to cellular disruption. Additionally, we demonstrate direct application for MC in repeated days cycling and conceivably other sporting scenario’s where back-to-back performances are required.

  3. De novo characterization of the Dialeurodes citri transcriptome: mining genes involved in stress resistance and simple sequence repeats (SSRs) discovery.

    Science.gov (United States)

    Chen, E-H; Wei, D-D; Shen, G-M; Yuan, G-R; Bai, P-P; Wang, J-J

    2014-02-01

    The citrus whitefly, Dialeurodes citri (Ashmead), is one of the three economically important whitefly species that infest citrus plants around the world; however, limited genetic research has been focused on D. citri, partly because of lack of genomic resources. In this study, we performed de novo assembly of a transcriptome using Illumina paired-end sequencing technology (Illumina Inc., San Diego, CA, USA). In total, 36,766 unigenes with a mean length of 497 bp were identified. Of these unigenes, we identified 17,788 matched known proteins in the National Center for Biotechnology Information database, as determined by Blast search, with 5731, 4850 and 14,441 unigenes assigned to clusters of orthologous groups (COG), gene ontology (GO), and SwissProt, respectively. In total, 7507 unigenes were assigned to 308 known pathways. In-depth analysis of the data showed that 117 unigenes were identified as potentially involved in the detoxification of xenobiotics and 67 heat shock protein (Hsp) genes were associated with environmental stress. In addition, these enzymes were searched against the GO and COG database, and the results showed that the three major detoxification enzymes and Hsps were classified into 18 and 3, 6, and 8 annotations, respectively. In addition, 149 simple sequence repeats were detected. The results facilitate the investigation of molecular resistance mechanisms to insecticides and environmental stress, and contribute to molecular marker development. The findings greatly improve our genetic understanding of D. citri, and lay the foundation for future functional genomics studies on this species.

  4. Prenatal flavor exposure affects flavor recognition and stress-related behavior of piglets.

    Science.gov (United States)

    Oostindjer, Marije; Bolhuis, J Elizabeth; van den Brand, Henry; Kemp, Bas

    2009-11-01

    Exposure to flavors in the amniotic fluid and mother's milk derived from the maternal diet has been shown to modulate food preferences and neophobia of young animals of several species. Aim of the experiment was to study the effects of pre- and postnatal flavor exposure on behavior of piglets during (re)exposure to this flavor. Furthermore, we investigated whether varying stress levels, caused by different test settings, affected behavior of animals during (re)exposure. Piglets were exposed to anisic flavor through the maternal diet during late gestation and/or during lactation or never. Piglets that were prenatally exposed to the flavor through the maternal diet behaved differently compared with unexposed pigs during reexposure to the flavor in several tests, suggesting recognition of the flavor. The differences between groups were more pronounced in tests with relatively high stress levels. This suggests that stress levels, caused by the design of the test, can affect the behavior shown in the presence of the flavor. We conclude that prenatal flavor exposure affects behaviors of piglets that are indicative of recognition and that these behaviors are influenced by stress levels during (re)exposure.

  5. Mercury and psychosocial stress exposure interact to predict maternal diurnal cortisol during pregnancy.

    Science.gov (United States)

    Schreier, Hannah M C; Hsu, Hsiao-Hsien; Amarasiriwardena, Chitra; Coull, Brent A; Schnaas, Lourdes; Téllez-Rojo, Martha María; Tamayo y Ortiz, Marcela; Wright, Rosalind J; Wright, Robert O

    2015-03-27

    Disrupted maternal prenatal cortisol production influences offspring development. Factors influencing the hypothalamic-pituitary-adrenal axis include social (e.g., stressful life events) and physical/chemical (e.g., toxic metals) pollutants. Mercury (Hg) is a common contaminant of fish and exposure is widespread in the US. No prior study has examined the joint associations of stress and mercury with maternal cortisol profiles in pregnancy. To investigate potential synergistic influences of prenatal stress and Hg exposures on diurnal cortisol in pregnant women. Analyses included 732 women (aged 27.4 ± 5.6 years) from a Mexico City pregnancy cohort. Participants collected saliva samples on two consecutive days (mean 19.52 ± 3.00 weeks gestation) and reported life stressors over the past 6 months. Hg was assessed in toe nail clippings collected during pregnancy. There were no main effects of Hg or psychosocial stress exposure on diurnal cortisol (ps > .20) but strong evidence of interaction effects on cortisol slope (interaction B = .006, SE = .003, p = .034) and cortisol at times 1 and 2 (interaction B = -.071, SE = .028, p = .013; B = -.078, SE = .032, p = .014). Women above the median for Hg and psychosocial stress exposure experienced a blunted morning cortisol response compared to women exposed to higher stress but lower Hg levels. Social and physical environmental factors interact to alter aspects of maternal diurnal cortisol during pregnancy. Research focusing solely on either domain may miss synergistic influences with potentially important consequences to the offspring.

  6. '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.

  7. Real-world exposure of airborne particulate matter triggers oxidative stress in an animal model

    Science.gov (United States)

    Wan, Guohui; Rajagopalan, Sanjay; Sun, Qinghua; Zhang, Kezhong

    2010-01-01

    Epidemiological studies have shown a strong link between air pollution and the increase of cardio-pulmonary mortality and morbidity. In particular, inhaled airborne particulate matter (PM) exposure is closely associated with the pathogenesis of air pollution-induced systemic diseases. In this study, we exposed C57BIV6 mice to environmentally relevant PM in fine and ultra fine ranges (diameter < 2.5 μm, PM2.5) using a “real-world” airborne PM exposure system. We investigated the pathophysiologic impact of PM2.5 exposure in the animal model and in cultured primary pulmonary macrophages. We demonstrated that PM2.5 exposure increased the production of reactive oxygen species (ROS) in blood vessels in vivo. Furthermore, in vitro PM2.5 exposure experiment suggested that PM2.5 could trigger oxidative stress response, reflected by an increased expression of the anti-oxidative stress enzymes superoxide dismutase-1 (SOD-1) and heme oxygenase-1(HO-1), in mouse primary macrophages. Together, the results obtained through our “real-world” PM exposure approach demonstrated the pathophysiologic effect of ambient PM2.5 exposure on triggering oxidative stress in the specialized organ and cell type of an animal model. Our results and approach will be informative for the research in air pollution-associated physiology and pathology. PMID:21383899

  8. Exposure to toluene and stress during pregnancy impairs pups' growth and dams' lactation.

    Science.gov (United States)

    Soberanes-Chávez, Paulina; López-Rubalcava, Carolina; de Gortari, Patricia; Cruz, Silvia L

    2013-01-01

    Inhalant misuse starts at an early age, and a large number of users are women in reproductive age. This study investigates whether exposure to toluene, a commonly misused solvent, alone or combined with restraint stress during pregnancy, produces adverse effects in pregnant mice and their offspring during lactation and adulthood. Pregnant animals were exposed to either 8000ppm toluene (30min/twice daily from gestational days 7-19), restraint stress (three times/day during the same gestation period) or both; control mice were only exposed to air. Our results show that toluene, stress and their combination reduced body weight gain in pregnant females without changing food consumption. In the offspring, all treatments resulted in low body weight at weaning, but with the toluene and stress combination this effect was seen from birth. Weight deficiency could not be attributed to poor maternal behavior during the first 3weeks of age, but to a reduction in pro-TRH mRNA expression in the hypothalamic paraventricular nucleus and serum prolactin levels in dams. After weaning, pups that were subjected to toluene and stress during gestation had lower body weight and ate less than control animals. In conclusion, the combined exposure to toluene and stress during pregnancy lead to more pronounced effects in dams and longer-lasting actions in pups than exposure to either toluene or stress. © 2013 Elsevier Inc. All rights reserved.

  9. Effects of prenatal exposure to chronic mild stress and toluene in rats

    DEFF Research Database (Denmark)

    Hougaard, K. S.; Andersen, Maud Bering; Hansen, A. M.

    2005-01-01

    The aim of the present study was to elucidate whether prenatal chronic stress, in combination with exposure to a developmental neurotoxicant, would increase effects in the offspring compared with the effects of either exposure alone. Development and neurobehavioral effects were investigated...... in female offspring of pregnant rats (Mol:WIST) exposed to chronic mild stress (CMS) during gestational days (GD) 9-20, or 1500 ppm toluene, 6 h/day during gestational days 7-20, or a combination of the two. Prenatal CMS was associated with decreased thymic weight and increased auditory startle response...... function due to CMS were observed. In the present experimental setting, there was no indication of the two exposures potentiating each other with respect to adverse effects on the nervous system. However, the effects of prenatal CMS indicate that stress during fetal life may interfere with the development...

  10. Influence of single and repeated cannabidiol administration on emotional behavior and markers of cell proliferation and neurogenesis in non-stressed mice.

    Science.gov (United States)

    Schiavon, Angélica Pupin; Bonato, Jéssica Mendes; Milani, Humberto; Guimarães, Francisco Silveira; Weffort de Oliveira, Rúbia Maria

    2016-01-04

    Therapeutic effects of antidepressants and atypical antipsychotics may arise partially from their ability to stimulate neurogenesis. Cannabidiol (CBD), a phytocannabinoid present in Cannabis sativa, presents anxiolytic- and antipsychotic-like effects in preclinical and clinical settings. Anxiolytic-like effects of repeated CBD were shown in chronically stressed animals and these effects were parallel with increased hippocampal neurogenesis. However, antidepressant-like effects of repeated CBD administration in non-stressed animals have been scarcely reported. Here we investigated the behavioral consequences of single or repeated CBD administration in non-stressed animals. We also determined the effects of CBD on cell proliferation and neurogenesis in the dentate gyrus (DG) and subventricular zone (SVZ). Single CBD 3mg/kg administration resulted in anxiolytic-like effect in mice submitted to the elevated plus maze (EPM). In the tail suspension test (TST), single or repeated CBD administration reduced immobility time, an effect that was comparable to those of imipramine (20 mg/kg). Moreover, repeated CBD administration at a lower dose (3 mg/kg) increased cell proliferation and neurogenesis, as seen by an increased number of Ki-67-, BrdU- and doublecortin (DCX)-positive cells in both in DG and SVZ. Despite its antidepressant-like effects in the TST, repeated CBD administration at a higher dose (30 mg/kg) decreased cell proliferation and neurogenesis in the hippocampal DG and SVZ. Our findings show a dissociation between behavioral and proliferative effects of repeated CBD and suggest that the antidepressant-like effects of CBD may occur independently of adult neurogenesis in non-stressed Swiss mice.

  11. 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...

  12. Exposure and peritraumatic response as predictors of posttraumatic stress in children following the 1995 Oklahoma City bombing

    OpenAIRE

    Pfefferbaum, Betty; Doughty, Debby E.; Reddy, Chandrashekar; Patel, Nilam; Gurwitch, Robin H.; Nixon, Sara Jo; Tivis, Rick D.

    2002-01-01

    Studies have demonstrated a positive relationship between exposure and posttraumatic stress, but one's subjective appraisal of danger and threat at the time of exposure may be a better predictor of posttraumatic stress than more objective measures of exposure. We examined the role of peritraumatic response in posttraumatic stress reactions in over 2,000 middle school children 7 weeks after the 1995 Oklahoma City, Oklahoma, bombing. While many children reported hearing and feeling the blast an...

  13. The role of parenting stress in young children's mental health functioning after exposure to family violence.

    Science.gov (United States)

    Roberts, Yvonne Humenay; Campbell, Christina A; Ferguson, Monette; Crusto, Cindy A

    2013-10-01

    This study evaluates the associations of young children's exposure to family violence events, parenting stress, and children's mental health functioning. Caregivers provided data for 188 children ages 3 to 5 years attending Head Start programming. Caregivers reported 75% of children had experienced at least 1 type of trauma event, and 27% of children had experienced a family violence event. Child mental health functioning was significantly associated with family violence exposure after controlling for children's age, gender, household income, and other trauma exposure (β = .14, p = .033). Stress in the parenting role partially mediated the relationship between family violence exposure and young children's mental health functioning (β = .12, p = .015, 95% confidence interval [0.02, 0.21]). Interventions for young children exposed to family violence should address the needs of the child, as well as the caregiver while also building healthy parent-child relationships to facilitate positive outcomes in children faced with trauma.

  14. Alteration of brain levels of neurotransmitters and amino acids in male F344 rats induced by three-week repeated inhalation exposure to 1-bromopropane.

    Science.gov (United States)

    Suda, Megumi; Honma, Takeshi; Miyagawa, Muneyuki; Wang, Rui-Sheng

    2008-08-01

    The present study investigated the effects of 1-bromopropane (1BP) on brain neuroactive substances of rats to determine the extent of its toxicity to the central nervous system (CNS). We measured the changes in neurotransmitters (acetylcholine, catecholamine, serotonin and amino acids) and their metabolites or precursors in eight brain regions after inhalation exposure to 1BP at 50 to 1,000 ppm for 8 h per day for 7 d per week for 3 wk. Rats were sacrificed at 2 h (Case 1), or at 19 h (Case 2) after the end of exposure. In Case 1, the level of 5-hydroxyindoleacetic acid (5HIAA) was lowered in some brain regions by 1BP exposure. The decrease of 5HIAA in the frontal cortex was statistically significant at 50 ppm 1BP exposure. In Case 2, gamma-amino butyric acid (GABA) and taurine were decreased in many brain regions of exposed rats, and a significant decrease of taurine in the midbrain occurred at 50 ppm 1BP exposure. In both cases of 2-h and 19-h intervals from the end of exposure to sacrifice, aspartate and glutamine levels were elevated in many brain regions, but the acetylcholine level did not change in any brain region. Three-week repeated exposure to 1BP produced significantly changes in amino acid contents of rat brains, particularly at 1,000 ppm.

  15. Effects of maternal exposure to social stress during pregnancy: consequences for mother and offspring.

    Science.gov (United States)

    Brunton, Paula J

    2013-01-01

    A suboptimal in utero environment, for example, as a result of maternal stress, can have detrimental effects on the pregnancy and long-term adverse 'programming' effects on the offspring. This article focuses on the effects of prenatal social stress on the mother, her pregnancy and the offspring, since these issues have ethological relevance in both animals and humans. The consequences of social stress exposure depend on when during pregnancy the stress occurs, and many of the effects on the offspring are sex specific. Social stress during early pregnancy tends to result in pregnancy loss, whereas stress exposure later in pregnancy, when the mother has already invested considerable resources in the foetuses, results in programmed offspring of low birth weight: a risk factor for various adulthood diseases. Neuroendocrine and behavioural responses to stress in the offspring are particularly sensitive to foetal programming by prenatal stress, indicated by enhanced hypothalamo-pituitary-adrenal (HPA) axis responses and increased anxiety behaviour, which result from permanent changes in the offspring's brain. The dysregulation of HPA axis function may also interfere with other systems, for example, the hypothalamic-pituitary-gonadal axis, as there is evidence for alterations in steroidogenesis, reproductive potential and impaired reproductive/social behaviours in prenatally stressed offspring. Prenatal social stress also programmes future maternal behaviour, highlighting the potential for negative phenotypes to be transmitted to future generations. The possible mechanisms through which maternal stress during pregnancy is transmitted to the foetuses and the foetal brain is programmed by prenatal stress and the potential to overwrite programming of the offspring are discussed.

  16. Heat exposure induces tissue stress in heat-intolerant, but not heat-tolerant, mice.

    Science.gov (United States)

    Islam, Aminul; Abraham, Preetha; Hapner, Christopher D; Andrews-Shigaki, Brian; Deuster, Patricia; Chen, Yifan

    2013-03-01

    We investigated the association of systemic and local tissue stress responses with heat-tolerant (TOL) levels in mice. Thirty-eight mice were assigned into control and three heat exposure groups-TOL, moderately tolerant, and intolerant (INT), based on their overall thermal responses. Real-time core temperature, blood pressure, and heart rate (HR) were assessed during heat exposure (39.5 °C) under conscious condition. Tissue samples were collected 18-22 h following heat exposure. INT mice had significantly higher peak mean arterial pressure and HR than TOL mice during heat exposure. Plasma corticosterone levels were significantly higher in INT than in control mice. No significant changes in plasma cytokines or markers of oxidative status were observed. INT mice showed significant increases in HSP72 and HSP90 protein and mRNA levels in liver, heart, and gastrocnemius muscles compared to TOL and control mice. In contrast, INT mice had significantly lower heat shock factor 1 and glucocorticoid receptor protein and mRNA levels in these tissues than TOL and control mice. These results indicate that acute heat exposure induces stress responses in various tissues of INT mice, but not TOL mice. Upregulation of stress proteins by acute heat exposure involves both transcriptional and translational pathways.

  17. [Occupational hazards, DNA damage, and oxidative stress on exposure to waste anesthetic gases].

    Science.gov (United States)

    Lucio, Lorena M C; Braz, Mariana G; do Nascimento Junior, Paulo; Braz, José Reinaldo C; Braz, Leandro G

    2017-06-24

    The waste anesthetic gases (WAGs) present in the ambient air of operating rooms (OR), are associated with various occupational hazards. This paper intends to discuss occupational exposure to WAGs and its impact on exposed professionals, with emphasis on genetic damage and oxidative stress. Despite the emergence of safer inhaled anesthetics, occupational exposure to WAGs remains a current concern. Factors related to anesthetic techniques and anesthesia workstations, in addition to the absence of a scavenging system in the OR, contribute to anesthetic pollution. In order to minimize the health risks of exposed professionals, several countries have recommended legislation with maximum exposure limits. However, developing countries still require measurement of WAGs and regulation for occupational exposure to WAGs. WAGs are capable of inducing damage to the genetic material, such as DNA damage assessed using the comet assay and increased frequency of micronucleus in professionals with long-term exposure. Oxidative stress is also associated with WAGs exposure, as it induces lipid peroxidation, oxidative damage in DNA, and impairment of the antioxidant defense system in exposed professionals. The occupational hazards related to WAGs including genotoxicity, mutagenicity and oxidative stress, stand as a public health issue and must be acknowledged by exposed personnel and responsible authorities, especially in developing countries. Thus, it is urgent to stablish maximum safe limits of concentration of WAGs in ORs and educational practices and protocols for exposed professionals. Copyright © 2017 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

  18. Impact of exposure to trauma on posttraumatic stress disorder symptomatology in Swedish tourist tsunami survivors.

    Science.gov (United States)

    Johannesson, Kerstin Bergh; Michel, Per-Olof; Hultman, Christina M; Lindam, Anna; Arnberg, Filip; Lundin, Tom

    2009-05-01

    The aim was to examine long-term mental health and posttraumatic stress symptomatology in a Swedish tourist population after exposure to the 2004 Southeast Asian tsunami. Data from 4822 returned questionnaires 14 months after the disaster were analyzed. Respondents were categorized into 3 subgroups: (1) danger-to-life exposure group (having been caught or chased by the waves), (2) nondanger-to-life exposure group (exposed to other disaster-related stressors), and (3) low exposure group. Main outcome measures were General Health Questionnaire-12 and Impact of Event Scale-22-Revised. Danger-to-life exposure was an important factor in causing more severe posttraumatic stress symptoms and in affecting mental health. Female gender, single status, and former trauma experiences were associated with greater distress. Other factors related to more severe symptoms were loss of relatives, physical injuries, viewing many dead bodies, experiencing life threat, and showing signs of cognitive confusion. Disaster exposure has a substantial impact on survivors, which stresses the need for long-lasting support.

  19. Increasing the repeating units of ethylene glycol-based dimethacrylates directed toward reduced oxidative stress and co-stimulatory factors expression in human monocytic cells.

    Science.gov (United States)

    Tamura, Atsushi; Fukumoto, Izumi; Yui, Nobuhiko; Matsumura, Mitsuaki; Miura, Hiroyuki

    2015-03-01

    The ethylene glycol-based dimethacrylates are commonly used in biomaterials and dental restorative materials as a cross-linking agent. In this study, toxic effect of triethylene glycol dimethacrylate (TEGDMA) and poly(ethylene glycol) dimethacrylates (PEG-DMAs) with various ethylene glycol repeating units was investigated in terms of cytotoxicity, oxidative stress, and the expression of co-stimulatory factors in human leukemia cell line (THP-1 cells) to verify the effect of ethylene glycol repeating units. Note that the 1-octanol/water partition coefficient of PEG-based dimethacrylates decreased with increasing the ethylene glycol repeating units, indicating that the hydrophilicity of PEG-DMAs increased with ethylene glycol repeating units. The toxic effect of PEG-DMAs such as cytotoxicity, oxidative stress, and the expression of CD86 in treated THP-1 cells are reduced with increasing the ethylene glycol repeating units in PEG-DMAs. However, the expression of CD54 in treated THP-1 cells was not influenced with the ethylene glycol repeating units and the maximal expression level of CD54 was observed at the concentration range of 2-4 mM for all samples. Accordingly, hydrophilic character of PEG-DMAs with long ethylene glycol chains definitely alleviates the some toxic aspect of PEG-based DMAs. This finding would provide important insight into the design of new biomaterials and dental materials with superior biocompatibility. © 2014 Wiley Periodicals, Inc.

  20. Residual Stress in TGO and Interfacial Damage in Thermal Barrier Coating after Thermal Exposure and Cyclic Indentation

    Science.gov (United States)

    Zhu, Shijie; Fukuda, Kunihisa; Osaki, Toru

    The local stress distributions in thermally grown oxide (TGO) layer of thermal barrier coating before and after thermal exposure were measured by photo-stimulated luminescence spectrum. The effect of isothermal oxidation on the residual stress in the TGO was investigated. It was found that the compressive stress in the TGO increased with an increase in thermal exposure time up to 100 hours and then decreased. The residual stresses in the TGO were also influenced by interfacial damage introduced by cyclic indentation.

  1. Histopathology of repeated, intermittent exposure of chloramine-T to walleye (Sander vitreum) and (Ictalurus punctalus) channel catfish

    Science.gov (United States)

    Gaikowski, M.P.; Densmore, Christine L.; Blazer, V.S.

    2009-01-01

    Chloramine-T (Cl-T) has been used safely and effectively to control bacterial gill disease in salmonids at a maximum exposure regimen of up to four consecutive, once-daily exposures administered for 60??min at 20??mg/L. However, data to document safe treatment concentrations of Cl-T are lacking for freshwater-reared fish other than salmonids. We report the histopathology resultant from the administration of 12 consecutive, once-daily, 180-min static immersion baths of 0, 20, 50, or 80??mg Cl-T/L to walleye (20????C) and channel catfish (27????C). Twelve fish of each species were euthanized immediately before the first exposure (initial controls) and then after the twelfth exposure and 7 and 14??days after the twelfth exposure. Only initial controls and fish euthanized immediately after the twelfth exposure were processed for histological review because of the general lack of exposure-related lesions in exposed fish. The only exposure-related histological changes were in the spleen where significantly greater erythrocyte swelling and necrosis was observed in channel catfish exposed at 80??mg/L relative to exposure at 0??mg/L; similar histological changes were insignificant for walleye, though there appeared to be a shift in the general category of histological change with degenerative changes (necrosis, etc.) observed following exposure at 50 or 80??mg/L compared to the inflammatory and hemodynamic changes (congestion, leukocyte infiltrate, etc.) observed in walleye exposed at 0 or 20??mg/L. The only significant change in peripheral blood cytology was that walleye fingerlings exposed at 80??mg/L had significantly fewer mature red blood cells and significantly more immature red blood cells per oil-immersion field than controls. The histopathological changes observed following exposure to Cl-T under an exaggerated exposure regimen suggest that walleye or channel catfish therapeutically exposed to Cl-T will not have treatment-related histological changes.

  2. Effects of prenatal exposure to combined stress on memory retention of passive avoidance learning in rats

    Directory of Open Access Journals (Sweden)

    Z. Homauni Afshari

    2015-10-01

    Full Text Available Background: Many studies have shown that prenatal stress affects development of fetal brain. Objective: The aim of this study was to evaluate the effect of prenatal exposure to combined stress on memory retention of passive avoidance learning in rats. Methods: This experimental study was performed on 16 male and 16 female Wistar rats in 2014. The rats were divided into four groups: male and female control groups, with natural pregnancy and two male and female treatment groups with exposure to combined stress (electromagnetic field, immobility and social stress in the second and third weeks of embryonic development. The learning was evaluated using shuttle box setup. Data were analyzed using ANOVA and Tukey test. Findings: The prenatal combined stress caused decrease in the latency time to enter the dark chamber in male and female new born rats in post-training periods especially the second week compared to the control groups. Conclusion: With regards to the results, prenatal exposure to combined stress can reduce the memory retention of passive avoidance learning.

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

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  4. Elodea nuttallii exposure to mercury exposure under enhanced ultraviolet radiation: Effects on bioaccumulation, transcriptome, pigment content and oxidative stress.

    Science.gov (United States)

    Regier, Nicole; Beauvais-Flück, Rebecca; Slaveykova, Vera I; Cosio, Claudia

    2016-11-01

    The hypothesis that increased UV radiation result in co-tolerance to Hg toxicity in aquatic plants was studied at the physiological and transcriptomic level in Elodea nuttallii. At the transcriptomic level, combined exposure to UV+Hg enhanced the stress response in comparison with single treatments, affecting the expression level of transcripts involved in energy metabolism, lipid metabolism, nutrition, and redox homeostasis. Single and combined UV and Hg treatments dysregulated different genes but with similar functions, suggesting a fine regulation of the plant to stresses triggered by Hg, UV and their combination but lack of co-tolerance. At the physiological level, UV+Hg treatment reduced chlorophyll content and depleted antioxidative compounds such as anthocyanin and GSH/GSSG in E. nuttallii. Nonetheless, combined exposure to UV+Hg resulted in about 30% reduction of Hg accumulation into shoots vs exposure to Hg alone, which was congruent with the level of expression of several transporter genes, as well as the UV effect on Hg bioavailability in water. The findings of the present work underlined the importance of performing experimentation under environmentally realistic conditions and to consider the interplay between contaminants and environmental variables such as light that might have confounding effects to better understand and anticipate the effects of multiple stressors in aquatic environment.

  5. Differential Effects of Controllable Stress Exposure on Subsequent Extinction Learning in Adult Rats.

    Science.gov (United States)

    Hadad-Ophir, Osnat; Brande-Eilat, Noa; Richter-Levin, Gal

    2015-01-01

    Deficits in fear extinction are thought to be related to various anxiety disorders. While failure to extinguish conditioned fear may result in pathological anxiety levels, the ability to quickly and efficiently attenuate learned fear through extinction processes can be extremely beneficial for the individual. One of the factors that may affect the efficiency of the extinction process is prior experience of stressful situations. In the current study, we examined whether exposure to controllable stress, which is suggested to induce stress resilience, can affect subsequent fear extinction. Here, following prolonged two-way shuttle (TWS) avoidance training and a validation of acquired stress controllability, adult rats underwent either cued or contextual fear-conditioning (FC), followed by an extinction session. We further evaluated long lasting alterations of GABAergic targets in the medial pre-frontal cortex (mPFC), as these were implicated in FC and extinction and stress controllability. In cued, but not in contextual fear extinction, within-session extinction was enhanced following controllable stress compared to a control group. Interestingly, impaired extinction recall was detected in both extinction types following the stress procedure. Additionally, stress controllability-dependent alterations in GABAergic markers expression in infralimbic (IL), but not prelimbic (PL) cortex, were detected. These alterations are proposed to be related to the within-session effect, but not the recall impairment. The results emphasize the contribution of prior experience on coping with subsequent stressful experiences. Moreover, the results emphasize that exposure to controllable stress does not generally facilitate future stress coping as previously claimed, but its effects are dependent on specific features of the events taking place.

  6. Cognitive behavioral therapy for insomnia as a preparatory treatment for exposure therapy for posttraumatic stress disorder.

    Science.gov (United States)

    Baddeley, Jenna L; Gros, Daniel F

    2013-01-01

    Insomnia is present in a majority of individuals with posttraumatic stress disorder (PTSD). However, when both disorders are present, disagreements exist about whether to provide exposure therapy for PTSD before insomnia treatment, or vice versa. The current case study describes the psychological treatment of a psychotherapy-naive veteran with comorbid insomnia and PTSD. The patient initially refused exposure therapy for PTSD; thus, cognitive-behavioral therapy for insomnia (CBTi) was a first-step treatment. Cognitive Behavior Therapy for Insomnia provided insomnia symptom relief psychoeducation and self-monitoring of PTSD symptoms prepared the patient to enter exposure therapy. After six CBTi sessions, the patient completed seven sessions of trauma-specific exposure therapy. At the conclusion of treatment and at 90-day follow up, the patient demonstrated significant reductions in insomnia and PTSD symptoms. Findings support the safe and effective use of CBTi in patients with comorbid insomnia and PTSD to improve sleep and facilitate entry into exposure therapy for PTSD.

  7. Effects of electromagnetic radiation exposure on stress-related behaviors and stress hormones in male wistar rats.

    Science.gov (United States)

    Mahdavi, Seyed Mohammad; Sahraei, Hedayat; Yaghmaei, Parichehreh; Tavakoli, Hassan

    2014-11-01

    Studies have demonstrated that electromagnetic waves, as the one of the most important physical factors, may alter cognitive and non-cognitive behaviors, depending on the frequency and energy. Moreover, non-ionizing radiation of low energy waves e.g. very low frequency waves could alter this phenomenon via alterations in neurotransmitters and neurohormones. In this study, short, medium, and long-term exposure to the extremely low frequency electromagnetic field (ELF-EMF) (1 and 5 Hz radiation) on behavioral, hormonal, and metabolic changes in male Wistar rats (250 g) were studied. In addition, changes in plasma concentrations for two main stress hormones, noradrenaline and adrenocorticotropic hormone (ACTH) were evaluated. ELF-EMF exposure did not alter body weight, and food and water intake. Plasma glucose level was increased and decreased in the groups which exposed to the 5 and 1Hz wave, respectively. Plasma ACTH concentration increased in both using frequencies, whereas nor-adrenaline concentration showed overall reduction. At last, numbers of rearing, sniffing, locomotor activity was increased in group receiving 5 Hz wave over the time. In conclusions, these data showed that the effects of 1 and 5 Hz on the hormonal, metabolic and stress-like behaviors may be different. Moreover, the influence of waves on stress system is depending on time of exposure.

  8. Exposure to radiofrequency radiation induces oxidative stress in duckweed Lemna minor L

    Energy Technology Data Exchange (ETDEWEB)

    Tkalec, Mirta [Department of Botany, Division of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, HR-10000 Zagreb (Croatia)], E-mail: mtkalec@zg.biol.pmf.hr; Malaric, Kresimir [Faculty of Electrical Engineering and Computing, University of Zagreb, Unska 3, HR-10000 Zagreb (Croatia); Pevalek-Kozlina, Branka [Department of Botany, Division of Biology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, HR-10000 Zagreb (Croatia)

    2007-12-15

    Widespread use of radiofrequency radiation emitting devices increased the exposure to electromagnetic fields (EMFs) from 300 MHz to 300 GHz. Various biological effects of exposure to these fields have been documented so far, but very little work has been carried out on plants. The aim of the present work was to investigate the physiological responses of the plant Lemna minor after exposure to radiofrequency EMFs, and in particular, to clarify the possible role of oxidative stress in the observed effects. Duckweed was exposed for 2 h to EMFs of 400 and 900 MHz at field strengths of 10, 23, 41 and 120 V m{sup -1}. The effect of a longer exposure time (4 h) and modulation was also investigated. After exposure, parameters of oxidative stress, such as lipid peroxidation, H{sub 2}O{sub 2} content, activities and isoenzyme pattern of antioxidative enzymes as well as HSP70 expression were evaluated. At 400 MHz, lipid peroxidation and H{sub 2}O{sub 2} content were significantly enhanced in duckweed exposed to EMFs of 23 and 120 V m{sup -1} while other exposure treatments did not have an effect. Compared to the controls, the activities of antioxidative enzymes showed different behaviour: catalase (CAT) activity increased after most exposure treatments while pyrogallol (PPX) and ascorbate peroxidase (APX) activities were not changed. Exceptions were reduced PPX and APX activity after longer exposure at 23 V m{sup -1} and increased PPX activity after exposures at 10 and 120 V m{sup -1}. By contrast, at 900 MHz almost all exposure treatments significantly increased level of lipid peroxidation and H{sub 2}O{sub 2} content but mostly decreased PPX activity and did not affect CAT activity. Exceptions were exposures to a modulated field and to the field of 120 V m{sup -1} which increased PPX and CAT activity. At this frequency APX activity was significantly decreased after exposure at 10 V m{sup -1} and longer exposure at 23 V m{sup -1} but it increased after a shorter exposure at

  9. Heart Rate, Stress, and Occupational Noise Exposure among Electronic Waste Recycling Workers

    Directory of Open Access Journals (Sweden)

    Katrina N. Burns

    2016-01-01

    Full Text Available Electronic waste (e-waste is a growing occupational and environmental health issue around the globe. E-waste recycling is a green industry of emerging importance, especially in low-and middle-income countries where much of this recycling work is performed, and where many people’s livelihoods depend on this work. The occupational health hazards of e-waste recycling have not been adequately explored. We performed a cross-sectional study of noise exposures, heart rate, and perceived stress among e-waste recycling workers at a large e-waste site in Accra, Ghana. We interviewed 57 workers and continuously monitored their individual noise exposures and heart rates for up to 24 h. More than 40% of workers had noise exposures that exceeded recommended occupational (85 dBA and community (70 dBA noise exposure limits, and self-reported hearing difficulties were common. Workers also had moderate to high levels of perceived stress as measured via Cohen’s Perceived Stress Scale, and reported a variety of symptoms that could indicate cardiovascular disease. Noise exposures were moderately and significantly correlated with heart rate (Spearman’s ρ 0.46, p < 0.001. A mixed effects linear regression model indicated that a 1 dB increase in noise exposure was associated with a 0.17 increase in heart rate (p-value = 0.01 even after controlling for work activities, age, smoking, perceived stress, and unfavorable physical working conditions. These findings suggest that occupational and non-occupational noise exposure is associated with elevations in average heart rate, which may in turn predict potential cardiovascular damage.

  10. Heart Rate, Stress, and Occupational Noise Exposure among Electronic Waste Recycling Workers.

    Science.gov (United States)

    Burns, Katrina N; Sun, Kan; Fobil, Julius N; Neitzel, Richard L

    2016-01-19

    Electronic waste (e-waste) is a growing occupational and environmental health issue around the globe. E-waste recycling is a green industry of emerging importance, especially in low-and middle-income countries where much of this recycling work is performed, and where many people's livelihoods depend on this work. The occupational health hazards of e-waste recycling have not been adequately explored. We performed a cross-sectional study of noise exposures, heart rate, and perceived stress among e-waste recycling workers at a large e-waste site in Accra, Ghana. We interviewed 57 workers and continuously monitored their individual noise exposures and heart rates for up to 24 h. More than 40% of workers had noise exposures that exceeded recommended occupational (85 dBA) and community (70 dBA) noise exposure limits, and self-reported hearing difficulties were common. Workers also had moderate to high levels of perceived stress as measured via Cohen's Perceived Stress Scale, and reported a variety of symptoms that could indicate cardiovascular disease. Noise exposures were moderately and significantly correlated with heart rate (Spearman's ρ 0.46, p < 0.001). A mixed effects linear regression model indicated that a 1 dB increase in noise exposure was associated with a 0.17 increase in heart rate (p-value = 0.01) even after controlling for work activities, age, smoking, perceived stress, and unfavorable physical working conditions. These findings suggest that occupational and non-occupational noise exposure is associated with elevations in average heart rate, which may in turn predict potential cardiovascular damage.

  11. Field study of the urinary excretion of ethoxyacetic acid during repeated daily exposure to the ethyl ether of ethylene glycol and the ethyl ether of ethylene glycol acetate.

    Science.gov (United States)

    Veulemans, H; Groeseneken, D; Masschelein, R; Van Vlem, E

    1987-06-01

    The urinary excretion of ethoxyacetic acid (EAA) was studied in a group of five women daily exposed to the ethyl ether of ethylene glycol (EGEE) and the ethyl ether of ethylene glycol acetate (EGEE-Ac) during 5 d of normal production and 7 d after a 12-d production stop. The mean combined exposure concentration of EGEE and EGEE-Ac (expressed in equivalent weight of EGEE) was 14.0 mg/m3 with occasional slight excursions above the current Belgian occupational exposure limit. The daily combined exposure profiles for EGEE and EGEE-Ac were rather constant during the first observation period, but they tended to decrease during the last week. The urinary EAA excretion clearly increased during the work week. Over the weekends the elimination was far from complete, and even after a prolonged nonexposure period of 12 d traces of the metabolite were still detectable. Based on the observations from the first period, a good linear correlation (r = 0.92) was found between the average exposure over 5 d (14.4 mg/m3) and the EAA excretion at the end of the week (105.7 mg/g creatinine). An EAA estimate of 150 +/- 35 mg/g was found to correspond with repeated 5-d full-shift exposures to the respective occupational exposure limit of EGEE (19 mg/m3) or EGEE-Ac (27 mg/m3).

  12. Association between changes in exposure to air pollution and biomarkers of oxidative stress in children before and during the Beijing Olympics.

    Science.gov (United States)

    Lin, Weiwei; Zhu, Tong; Xue, Tao; Peng, Wei; Brunekreef, Bert; Gehring, Ulrike; Huang, Wei; Hu, Min; Zhang, Yuanhang; Tang, Xiaoyan

    2015-04-15

    It is not known whether exposure to air pollutants causes systemic oxidative stress in children. We investigated the association between exposure to air pollution and biomarkers of oxidative stress in relation to a governmental air quality intervention implemented during the 2008 Beijing Olympic Games. We studied 36 schoolchildren during 5 time periods before and during the Olympic Games in Beijing (June 2007-September 2008). The oxidative stress biomarkers 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and malondialdehyde were measured in urine samples collected daily during each period. Generalized estimating equations were used to examine the relationship between repeated biomarker measurements and ambient air pollutant levels. During the Olympic intervention period, substantial reductions in air pollution (-19% to -72%), urinary 8-oxodG concentrations (-37.4%; 95% confidence interval: -53.5, -15.7), and urinary malondialdehyde concentrations (-25.3%; 95% confidence interval: -34.3, -15.1) were found. Malondialdehyde and 8-oxodG were significantly associated with concentrations of black carbon, fine particulate matter with an aerodynamic with diameter less than 2.5 μm, sulfur dioxide, nitrogen dioxide, and carbon monoxide. Biomarker changes per each interquartile-range increase in pollutants were largest at lag 0 or lag 1. In a 2-pollutant model, the most robust associations were for black carbon. These findings suggest that exposure to black carbon leads to systemic oxidative stress in children.

  13. Trauma exposure, posttraumatic stress, and preventive health behaviours: a systematic review.

    Science.gov (United States)

    Lee, Sharon Y; Park, Crystal L

    2017-09-19

    Psychological trauma has implications for many aspects of physical health, including preventive health behaviours (PHBs). However, whether trauma exposure additionally contributes to PHBs above and beyond the effects of posttraumatic stress disorder (PTSD) symptoms remains unclear. In this systematic review, 32 studies were analysed to characterise: (1) the relationships between trauma exposure and PHBs, (2) the relationships between PTSD symptoms and PHBs, (3) the unique associations between trauma exposure and PHBs, independent of PTSD symptoms, and (4) the unique associations between PTSD symptoms and PHBs, independent of trauma exposure. Findings were variable across the three examined PHBs (physical activity, diet, medical screening) when only trauma exposure or PTSD symptoms were taken into account. Clearer relationships emerged between trauma exposure and PHBs when PTSD symptoms were taken into account, demonstrating that trauma exposure is related to PHB engagement above and beyond the effects of PTSD symptoms. Additionally, PTSD symptoms shared unique associations with physical activity and screening frequency, which were not explained by trauma exposure. Our review reveals that teasing apart the effects of trauma exposure and PTSD symptoms on PHBs brings greater clarity to the strength and direction of these associations.

  14. Early Maternal Deprivation Enhances Voluntary Alcohol Intake Induced by Exposure to Stressful Events Later in Life

    Directory of Open Access Journals (Sweden)

    Sara Peñasco

    2015-01-01

    Full Text Available In the present study, we aimed to assess the impact of early life stress, in the form of early maternal deprivation (MD, 24 h on postnatal day, pnd, 9, on voluntary alcohol intake in adolescent male and female Wistar rats. During adolescence, from pnd 28 to pnd 50, voluntary ethanol intake (20%, v/v was investigated using the two-bottle free choice paradigm. To better understand the relationship between stress and alcohol consumption, voluntary alcohol intake was also evaluated following additional stressful events later in life, that is, a week of alcohol cessation and a week of alcohol cessation combined with exposure to restraint stress. Female animals consumed more alcohol than males only after a second episode of alcohol cessation combined with restraint stress. MD did not affect baseline voluntary alcohol intake but increased voluntary alcohol intake after stress exposure, indicating that MD may render animals more vulnerable to the effects of stress on alcohol intake. During adolescence, when animals had free access to alcohol, MD animals showed lower body weight gain but a higher growth rate than control animals. Moreover, the higher growth rate was accompanied by a decrease in food intake, suggesting an altered metabolic regulation in MD animals that may interact with alcohol intake.

  15. Early maternal deprivation enhances voluntary alcohol intake induced by exposure to stressful events later in life.

    Science.gov (United States)

    Peñasco, Sara; Mela, Virginia; López-Moreno, Jose Antonio; Viveros, María-Paz; Marco, Eva M

    2015-01-01

    In the present study, we aimed to assess the impact of early life stress, in the form of early maternal deprivation (MD, 24 h on postnatal day, pnd, 9), on voluntary alcohol intake in adolescent male and female Wistar rats. During adolescence, from pnd 28 to pnd 50, voluntary ethanol intake (20%, v/v) was investigated using the two-bottle free choice paradigm. To better understand the relationship between stress and alcohol consumption, voluntary alcohol intake was also evaluated following additional stressful events later in life, that is, a week of alcohol cessation and a week of alcohol cessation combined with exposure to restraint stress. Female animals consumed more alcohol than males only after a second episode of alcohol cessation combined with restraint stress. MD did not affect baseline voluntary alcohol intake but increased voluntary alcohol intake after stress exposure, indicating that MD may render animals more vulnerable to the effects of stress on alcohol intake. During adolescence, when animals had free access to alcohol, MD animals showed lower body weight gain but a higher growth rate than control animals. Moreover, the higher growth rate was accompanied by a decrease in food intake, suggesting an altered metabolic regulation in MD animals that may interact with alcohol intake.

  16. Long-term effects of early life stress exposure: Role of epigenetic mechanisms.

    Science.gov (United States)

    Silberman, Dafne M; Acosta, Gabriela B; Zorrilla Zubilete, María A

    2016-07-01

    Stress is an adaptive response to demands of the environment and thus essential for survival. Exposure to stress during the first years of life has been shown to have profound effects on the growth and development of an adult individual. There are evidences demonstrating that stressful experiences during gestation or in early life can lead to enhanced susceptibility to mental disorders. Early-life stress triggers hypothalamic-pituitary-adrenocortical (HPA) axis activation and the associated neurochemical reactions following glucocorticoid release are accompanied by a rapid physiological response. An excessive response may affect the developing brain resulting in neurobehavioral and neurochemical changes later in life. This article reviews the data from experimental studies aimed to investigate hormonal, functional, molecular and epigenetic mechanisms involved in the stress response during early-life programming. We think these studies might prove useful for the identification of novel pharmacological targets for more effective treatments of mental disorders.

  17. Modifying Exposure-Based CBT for Cambodian Refugees with Posttraumatic Stress Disorder

    Science.gov (United States)

    Otto, Michael W.; Hinton, Devon E.

    2006-01-01

    Cambodian refugees represent a severely traumatized population living in the United States. In this paper, we describe the modification of a cognitive-behavior therapy program to facilitate delivery of an exposure-based treatment for posttraumatic stress disorder while addressing some of the challenges brought by differences in language and…

  18. Beyond Exposure for Posttraumatic Stress Disorder (PTSD) Symptoms: Broad-Spectrum PTSD Treatment Strategies

    Science.gov (United States)

    Lombardo, Thomas W.; Gray, Matt J.

    2005-01-01

    Although cases of posttraumatic stress disorder (PTSD) with comorbid disorders are common, the first generation of PTSD treatment approaches, including exposure and cognitive-behavioral therapy, generally ignore symptoms beyond those specific to PTSD. Optimum PTSD treatment outcome requires more comprehensive strategies, and the development and…

  19. Exposure to Political Conflict and Violence and Posttraumatic Stress in Middle East Youth: Protective Factors

    Science.gov (United States)

    Dubow, Eric F.; Huesmann, L. Rowell; Boxer, Paul; Landau, Simha; Dvir, Shira; Shikaki, Khalil; Ginges, Jeremy

    2012-01-01

    We examine the role of family- and individual-level protective factors in the relation between exposure to ethnic-political conflict and violence and posttraumatic stress among Israeli and Palestinian youth. Specifically, we examine whether parental mental health (lack of depression), positive parenting, children's self-esteem, and academic…

  20. Cumulative Effects of Exposure to Violence on Posttraumatic Stress in Palestinian and Israeli Youth

    Science.gov (United States)

    Dubow, Eric F.; Boxer, Paul; Huesmann, L. Rowell; Landau, Simha; Dvir, Shira; Shikaki, Khalil; Ginges, Jeremy

    2012-01-01

    We examine cumulative and prospective effects of exposure to conflict and violence across four contexts (ethnic-political, community, family, school) on posttraumatic stress (PTS) symptoms in Palestinian and Israeli youth. Interviews were conducted with 600 Palestinian and 901 Israeli (Jewish and Arab) children (ages 8, 11, and 14) and their…

  1. Heart Rate, Stress, and Occupational Noise Exposure among Electronic Waste Recycling Workers

    National Research Council Canada - National Science Library

    Burns, Katrina N; Sun, Kan; Fobil, Julius N; Neitzel, Richard L

    2016-01-01

    .... The occupational health hazards of e-waste recycling have not been adequately explored. We performed a cross-sectional study of noise exposures, heart rate, and perceived stress among e-waste recycling workers at a large e-waste site in Accra, Ghana...

  2. Heart Rate, Stress, and Occupational Noise Exposure among ElectronicWaste Recycling Workers

    National Research Council Canada - National Science Library

    Katrina N Burns; Kan Sun; Julius N Fobil; Richard L Neitzel

    2016-01-01

    .... The occupational health hazards of e-waste recycling have not been adequately explored. We performed a cross-sectional study of noise exposures, heart rate, and perceived stress among e-waste recycling workers at a large e-waste site in Accra, Ghana...

  3. Visual feedback in written imaginal exposure for posttraumatic stress: a preliminary study

    NARCIS (Netherlands)

    Truijens, F.L.; van Emmerik, A.A.P.

    2014-01-01

    This study investigated the visual feedback hypothesis, which states that visual feedback from written trauma narratives contributes to the efficacy of written imaginal exposure in reducing posttraumatic stress, as visual feedback allows for the reuptake of traumatic content during the production of

  4. Childhood exposure to violence and lifelong health: Clinical intervention science and stress biology research join forces

    Science.gov (United States)

    Moffitt, Terrie E.

    2013-01-01

    Many young people who are mistreated by an adult, victimized by bullies, criminally assaulted, or who witness domestic violence react to this violence exposure by developing behavioral, emotional, or learning problems. What is less well known is that adverse experiences like violence exposure can lead to hidden physical alterations inside a child’s body, alterations which may have adverse effects on life-long health. We discuss why this is important for the field of developmental psychopathology and for society, and we recommend that stress-biology research and intervention science join forces to tackle the problem. We examine the evidence base in relation to stress-sensitive measures for the body (inflammatory reactions, telomere erosion, epigenetic methylation, and gene expression) and brain (mental disorders, neuroimaging, and neuropsychological testing). We also review promising interventions for families, couples, and children that have been designed to reduce the effects of childhood violence exposure. We invite intervention scientists and stress-biology researchers to collaborate in adding stress-biology measures to randomized clinical trials of interventions intended to reduce effects of violence exposure and other traumas on young people. PMID:24342859

  5. Understanding the Impact of Trauma Exposure on Posttraumatic Stress Symptomatology: A Structural Equation Modeling Approach

    Science.gov (United States)

    Chen, Wei; Wang, Long; Zhang, Xing-Li; Shi, Jian-Nong

    2012-01-01

    The objective of this study was to investigate the impact of trauma exposure on the posttraumatic stress symptomatology (PTSS) of children who resided near the epicenter of the 2008 Wenchuan earthquake. The mechanisms of this impact were explored via structural equation models with self-esteem and coping strategies included as mediators. The…

  6. Exposure to Political Conflict and Violence and Posttraumatic Stress in Middle East Youth: Protective Factors

    Science.gov (United States)

    Dubow, Eric F.; Huesmann, L. Rowell; Boxer, Paul; Landau, Simha; Dvir, Shira; Shikaki, Khalil; Ginges, Jeremy

    2012-01-01

    We examine the role of family- and individual-level protective factors in the relation between exposure to ethnic-political conflict and violence and posttraumatic stress among Israeli and Palestinian youth. Specifically, we examine whether parental mental health (lack of depression), positive parenting, children's self-esteem, and academic…

  7. Understanding the Impact of Trauma Exposure on Posttraumatic Stress Symptomatology: A Structural Equation Modeling Approach

    Science.gov (United States)

    Chen, Wei; Wang, Long; Zhang, Xing-Li; Shi, Jian-Nong

    2012-01-01

    The objective of this study was to investigate the impact of trauma exposure on the posttraumatic stress symptomatology (PTSS) of children who resided near the epicenter of the 2008 Wenchuan earthquake. The mechanisms of this impact were explored via structural equation models with self-esteem and coping strategies included as mediators. The…

  8. Allergic inflammation in the upper respiratory tract of the rat upon repeated inhalation exposure to the contact allergen dinitrochlorobenzene (DNCB).

    NARCIS (Netherlands)

    Triel, J.J. van; Arts, J.H.; Muijser, H.; Kuper, C.F.

    2010-01-01

    Previously, the contact allergen dinitrochlorobenzene (DNCB) was identified as a sensitizer by inhalation in BALB/c mice; in addition, DNCB induced a lymphocytic infiltrate in the larynx of dermally sensitized Th1-prone Wistar rats upon a single inhalation challenge. In the present study, repeated

  9. Allergic inflammation in the upper respiratory tract of the rat upon repeated inhalation exposure to the contact allergen dinitrochlorobenzene (DNCB).

    NARCIS (Netherlands)

    Triel, J.J. van; Arts, J.H.; Muijser, H.; Kuper, C.F.

    2010-01-01

    Previously, the contact allergen dinitrochlorobenzene (DNCB) was identified as a sensitizer by inhalation in BALB/c mice; in addition, DNCB induced a lymphocytic infiltrate in the larynx of dermally sensitized Th1-prone Wistar rats upon a single inhalation challenge. In the present study, repeated i

  10. 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 Damgård; 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 ...

  11. Effects of repeated hyperbaric nitrogen-oxygen exposures on the striatal dopamine release and on motor disturbances in rats.

    Science.gov (United States)

    Lavoute, Cécile; Weiss, Michel; Rostain, Jean-Claude

    2005-09-14

    Previous studies have demonstrated disruptions of motor activities and a decrease of extracellular dopamine level in the striatum of rats exposed to high pressure of nitrogen. Men exposed to nitrogen pressure develop also motor and cognitive disturbances related to inert gas narcosis. After repetitive exposures, adaptation to narcosis was subjectively reported. To study the effects of repetitive exposures to hyperbaric nitrogen-oxygen, male Sprague-Dawley rats were implanted in the striatum with multifiber carbon dopamine-sensitive electrodes. After recovery from surgery, free-moving rats were exposed for 2 h up to 3 MPa of nitrogen-oxygen mixture before and after one daily exposure to 1 MPa of nitrogen-oxygen, for 5 consecutive days. Dopamine release was measured by differential pulse voltammetry and motor activities were quantified using piezo-electric captor. At the first exposure to 3 MPa, the striatal dopamine level decreased during the compression (-15%) to reach -20% during the stay at 3 MPa. Motor activities were increased during compression (+15%) and the first 60 min at constant pressure (+10%). In contrast, at the second exposure to 3 MPa, an increase of dopamine of +15% was obtained during the whole exposure. However, total motor activities remained unchanged as compared to the first exposure. Our results confirm that nitrogen exposure at 3 MPa led to a decreased striatal dopamine release and increased motor disturbances in naïve rats. Repetitive exposures to 1 MPa of nitrogen induced a reversal effect on the dopamine release which suggests a neurochemical change at the level of the neurotransmitter regulation processes of the basal ganglia. In contrast, motor activity remained quantitatively unchanged, thus suggesting that dopamine is not involved alone in modulating these motor disturbances.

  12. 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

  13. Prenatal Cocaine Exposure Alters Cortisol Stress Reactivity in 11 Year Old Children

    Science.gov (United States)

    Lester, Barry M.; LaGasse, Linda L.; Shankaran, Seetha; Bada, Henrietta S.; Bauer, Charles R.; Lin, Richard; Das, Abhik; Higgins, Rosemary

    2011-01-01

    Objective Determine the association between prenatal cocaine exposure and postnatal environmental adversity on salivary cortisol stress reactivity in school aged children. Study design Subjects included 743 11 year old children (n=320 cocaine exposed; 423 comparison) followed since birth in a longitudinal prospective multisite study. Saliva samples were collected to measure cortisol at baseline and after a standardized procedure to induce psychological stress. Children were divided into those who showed an increase in cortisol from baseline to post stress and those who showed a decrease or blunted cortisol response. Covariates measured included site, birthweight, maternal pre and postnatal use of alcohol, tobacco or marijuana, social class, changes in caretakers, maternal depression and psychological symptoms, domestic and community violence, child abuse and quality of the home. Results With adjustment for confounding variables, cortisol reactivity to stress was more likely to be blunted in children with prenatal cocaine exposure. Cocaine exposed children exposed to domestic violence showed the strongest effects. Conclusion The combination of prenatal cocaine exposure and an adverse postnatal environment could down regulate the hypothalamic-pituitary-adrenal axis (HPA) resulting in the blunted cortisol response to stress possibly increasing risk for later psychopathology and adult disease. PMID:20400094

  14. Re-exposure and environmental enrichment reveal NPY-Y1 as a possible target for post-traumatic stress disorder.

    Science.gov (United States)

    Hendriksen, Hendrikus; Bink, Diewertje I; Daniels, Eileen G; Pandit, Rahul; Piriou, Carole; Slieker, Roderick; Westphal, Koen G C; Olivier, Berend; Oosting, Ronald S

    2012-09-01

    Exposure-based cognitive behavioral therapy in post-traumatic stress disorder (PTSD) patients relieves symptoms caused by fear association as well as symptoms that are not the result of associative learning. We used the inescapable foot shock model (IFS), an animal model for PTSD, to study the possible involvement of glutamate receptors, the corticotropin-releasing factor (CRF) system, and the neuropeptide Y (NPY) system in the reduction of stress sensitization following repeated re-exposure to the conditioning context. Starting one week after the IFS procedure, the rats were repeatedly re-exposed to the shock environment. Stress sensitivity was measured in a modified open field test (sudden silence was used as a stressor). Selected mRNAs (GluN1, -2A-C, GluA1-4, GluK1-5, CRF, CRF-R1, NPY, NPY-Y1) were quantified in the amygdala. Repeated re-exposure (RE) to the IFS context reduced both trauma-associated anxiety (to the IFS context) and the enhanced stress sensitivity (in the open field). Changes in glutamate receptor subunits (GluN1, GluN2A-B, GluA1, GluA4, GluK3, GluK4) were detected in the amygdala that were normalized by RE. However, infusion of the AMPA/kainate antagonist NBQX in the BLA (basolateral amygdala) did not improve the anxious behavior. RE normalized IFS-induced increases in CRF-R1 mRNA and increased NPY-Y1 mRNA expression in the amygdala. Previously, and repeated here, we showed that environmental enrichment (EE) enhances recovery from IFS. EE led to similar changes in CRF-R1 and NPY-Y1 expression as RE did. Importantly, administration of [Leu31, Pro34]-NPY (Y1 agonist) in the BLA normalized the enhanced sensitivity to stress after IFS. Our data suggest that the NPY-Y1 receptor in the amygdala may serve as a therapeutic target for the treatment of PTSD.

  15. Lung injury via oxidative stress in mice induced by inhalation exposure to rocket kerosene.

    Science.gov (United States)

    Xu, Bingxin; Li, Chenglin; Wang, Jianying; Wu, Jihua; Si, Shaoyan; Liu, Zhiguo; Li, Jianzhong; Zhang, Jianzhong; Cui, Yan

    2015-01-01

    Rocket kerosene (RK) is a new rocket propellant. Toxicity occurs if a high level of RK is inhaled. To study the toxicity of RK in lung and the mechanisms of RK-induced lung jury, a total of 72 male ICR mice (1.5 months, adult) were randomly assigned to the RK exposure group (RKEG) and normal control group (NCG). Mice were whole-body exposed to room air or aerosol of 18000 mg/m3 RK for 4 hours. Histopathological analysis was performed to evaluate the pulmonary lesions. Oxidative stress was assessed by assay of MDA, SOD, GSH-PX and TAOC. Inflammatory response was estimated by detecting inflammatory cell counts, TNF-α and IL-6 protein levels in serum. The results showed that after 2 to 6 hours of RK exposure, pulmonary vascular dilatation, congestion and edematous widening of the alveolar septum were noted. After 12 to 24 hours post-exposure, diffuse hemorrhage in alveolar space were found, along with the progressive pulmonary vascular dilatation and edematous widening of alveolar septum. During 3 to 7 days of RK-exposure, inflammatory cells were scattered in the lung tissue. The pathological alterations of the lung were alleviated after 14 days post-exposure, and showed significant improvement after 21 days post-exposure. After 30 days of RK exposure, the pathological changes in the lung tissue were nearly recovered except the local thickening of the alveolar wall. Compared with NCG, RK inhalation produced a significant increase of MDA levels and a significant decrease of SOD, GSH-Px and TAOC activity in the lung after 2 hours post-exposure (P<0.05). There were significant increases of TNF-α and IL-6 protein levels in serum of mice in RKEG after 2, 6 and 12 hours and 1, 4 and 7 days post-exposure compared with NCG (P<0.05). TNF-α protein levels had a sharp increase after 4 days of exposure. IL-6 protein level was increased at early phase of experiment and then gradually decreased along with the prolonged course of exposure. Considering that the RK-induced lung

  16. Does uranium exposure induce oxidative stress and genotoxicity in the teleostean Danio rerio? first experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Barillet, S.; Devaux, A.; Simon, O.; Buet, A.; Pradines, C. [CEA Cadarache (DEI/SECRE/LRE), Laboratory of Radioecology and Ecotoxicology, Institute for Radioprotection and Nuclear Safety, 13 - Saint-Paul-lez-Durance (France)

    2004-07-01

    Within the Envirhom research program, key advances have been obtained in uranium bioaccumulation and underlying mechanisms understanding in various biological models at the individual level. However, considering different scales of biological effects (from early to delayed ones, from low to high level of organization) is crucial to provide ecologically relevant indicators. Organisms counteract stress induced by pollutant exposure through a wide range of physiological responses being both dose and time dependent. Effects at higher hierarchical levels are always preceded by early changes in biological processes, from subtle biochemical disturbances to impaired physiological functions, increased susceptibility to other stresses, reduced life-span Within this global context, preliminary experiments were carried out on adult zebra fish (Danio rerio), to assess early changes after short-term uranium exposure. Among the subsequent primary subcellular damages oxidative stress and genotoxicity (characterizing both chemo-toxicity and radiotoxicity) are relevant endpoints, thus requiring the knowledge of dose-effects relationships as a first operational approach to provide useful tool in predicting possible effects of U exposure. Zebra fish has been selected due to its small size (facilitating its maintenance) and its extended use in eco-toxicological studies. Moreover, its short life-cycle will allow to carry out chronic exposure experiments (along the whole life-cycle). Four uranium concentrations (0, 20, 100 and 500{mu}g.L{sup -1}) and five sampling times (0, 0.5, 1, 5 and 10 days) were selected. Catalase, glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were measured as oxidative stress bio-markers. DNA damage level was assessed in zebra fish erythrocytes using the comet assay. Uranium bioaccumulation was concurrently studied to understand observed bio-marker responses. Further experiments, dedicated to the assessment of the impact of chronic uranium

  17. Decreased level of Nurr1 in heterozygous young adult mice leads to exacerbated acute and long-term toxicity after repeated methamphetamine exposure.

    Directory of Open Access Journals (Sweden)

    Yu Luo

    Full Text Available The abuse of psychostimulants, such as methamphetamine (METH, is prevalent in young adults and could lead to long-term adaptations in the midbrain dopamine system in abstinent human METH abusers. Nurr1 is a gene that is critical for the survival and maintenance of dopaminergic neurons and has been implicated in dopaminergic neuron related disorders. In this study, we examined the synergistic effects of repeated early exposure to methamphetamine in adolescence and reduction in Nurr1 gene levels. METH binge exposure in adolescence led to greater damage in the nigrostrial dopaminergic system when mice were exposed to METH binge later in life, suggesting a long-term adverse effect on the dopaminergic system. Compared to naïve mice that received METH binge treatment for the first time, mice pretreated with METH in adolescence showed a greater loss of tyrosine hydroxylase (TH immunoreactivity in striatum, loss of THir fibers in the substantia nigra reticulata (SNr as well as decreased dopamine transporter (DAT level and compromised DA clearance in striatum. These effects were further exacerbated in Nurr1 heterozygous mice. Our data suggest that a prolonged adverse effect exists following adolescent METH binge exposure which may lead to greater damage to the dopaminergic system when exposed to repeated METH later in life. Furthermore, our data support that Nurr1 mutations or deficiency could be a potential genetic predisposition which may lead to higher vulnerability in some individuals.

  18. Repeated measures of inflammation, blood pressure, and heart rate variability associated with personal traffic exposures in healthy adults

    Science.gov (United States)

    BACKGROUND: Previous human exposure studies of traffic-related air pollutants have demonstrated adverse health effects in human populations by comparing areas of high and low traffic, but few studies have utilized microenvironmental monitoring of pollutants at multiple traffic lo...

  19. Repeated measures of inflammation, blood pressure, and heart rate variability associated with personal traffic exposures in healthy adults

    Science.gov (United States)

    BACKGROUND: Previous human exposure studies of traffic-related air pollutants have demonstrated adverse health effects in human populations by comparing areas of high and low traffic, but few studies have utilized microenvironmental monitoring of pollutants at multiple traffic lo...

  20. 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.

  1. Quantifying Chronic Stress Exposure for Cumulative Risk Assessment: Lessons Learned from a Case Study of Allostatic Load

    Science.gov (United States)

    Although multiple methods of quantifying environmental chemical exposures have been validated for use in human health risk assessment, quantifying chronic stress exposure is more challenging. Stress is a consequence of perceiving an “exposure” (e.g., violence, poverty) as more th...

  2. Upregulation of CB₁ receptor binding in the ventromedial prefrontal cortex promotes proactive stress-coping strategies following chronic stress exposure.

    Science.gov (United States)

    McLaughlin, R J; Hill, M N; Dang, S S; Wainwright, S R; Galea, L A M; Hillard, C J; Gorzalka, B B

    2013-01-15

    Accumulating evidence has revealed that dysregulation of the endocannabinoid system could contribute to the development of major depression. Studies carried out post-mortem in depressed suicide victims have revealed increased CB(1) receptor binding site density in the prefrontal cortex (PFC). Accordingly, exposure of rodents to chronic unpredictable stress (CUS) results in phenotypic changes that mirror those of human depression, including increased CB(1) receptor binding site density in the PFC. Our goal in these studies was to examine the effects of CUS on the density of CB(1) receptor binding sites in the rodent medial PFC and to explore the role of this alteration in the behavioral changes invoked by CUS. Rodents exposed to CUS exhibited increased CB(1) receptor maximal binding site density (B(max)) within the ventromedial PFC, but not the dorsomedial PFC. To determine whether this change in the ventromedial PFC is an adaptive response, or alternatively, a consequence of chronic stress that contributes to the adoption of passive coping, we examined whether local CB(1) receptor blockade within the ventromedial PFC following CUS would significantly alter behaviors in the forced swim test (FST). CUS exposure significantly increased passive coping in the FST, and this was further augmented by discrete ventromedial PFC microinfusions of the CB(1) receptor antagonist AM251 prior to swim stress. Moreover, local CB(1) receptor blockade reduced active coping responses in CUS-exposed rats. These findings suggest that the increase in CB(1) receptor B(max) observed in the ventromedial PFC of rodents exposed to CUS maintains proactive coping strategies following chronic stress exposure.

  3. Comparative systems toxicology analysis of cigarette smoke and aerosol from a candidate modified risk tobacco product in organotypic human gingival epithelial cultures: A 3-day repeated exposure study.

    Science.gov (United States)

    Zanetti, Filippo; Titz, Bjoern; Sewer, Alain; Lo Sasso, Giuseppe; Scotti, Elena; Schlage, Walter K; Mathis, Carole; Leroy, Patrice; Majeed, Shoaib; Torres, Laura Ortega; Keppler, Brian R; Elamin, Ashraf; Trivedi, Keyur; Guedj, Emmanuel; Martin, Florian; Frentzel, Stefan; Ivanov, Nikolai V; Peitsch, Manuel C; Hoeng, Julia

    2017-03-01

    Smoking is one of the major lifestyle-related risk factors for periodontal diseases. Modified risk tobacco products (MRTP) offer a promising alternative in the harm reduction strategy for adult smokers unable to quit. Using a systems toxicology approach, we investigated and compared the exposure effects of a reference cigarette (3R4F) and a heat-not-burn technology-based candidate MRTP, the Tobacco Heating System (THS) 2.2. Human gingival epithelial organotypic cultures were repeatedly exposed (3 days) for 28 min at two matching concentrations of cigarette smoke (CS) or THS2.2 aerosol. Results showed only minor histopathological alterations and minimal cytotoxicity upon THS2.2 aerosol exposure compared to CS (1% for THS2.2 aerosol vs. 30% for CS, at the high concentration). Among the 14 proinflammatory mediators analyzed, only 5 exhibited significant alterations with THS2.2 exposure compared with 11 upon CS exposure. Transcriptomic and metabolomic analysis indicated a general reduction of the impact in THS2.2 aerosol-exposed samples with respect to CS (∼79% lower biological impact for the high THS2.2 aerosol concentration compared to CS, and 13 metabolites significantly perturbed for THS2.2 vs. 181 for CS). This study indicates that exposure to THS2.2 aerosol had a lower impact on the pathophysiology of human gingival organotypic cultures than CS. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Emotion dysregulation as a mechanism linking stress exposure to adolescent aggressive behavior.

    Science.gov (United States)

    Herts, Kate L; McLaughlin, Katie A; Hatzenbuehler, Mark L

    2012-10-01

    Exposure to stress is associated with a wide range of internalizing and externalizing problems in adolescents, including aggressive behavior. Extant research examining mechanisms underlying the associations between stress and youth aggression has consistently identified social information processing pathways that are disrupted by exposure to violence and increase risk of aggressive behavior. In the current study, we use longitudinal data to examine emotion dysregulation as a potential mechanism linking a broader range of stressful experiences to aggressive behavior in a diverse sample of early adolescents (N = 1065). Specifically, we examined the longitudinal associations of peer victimization and stressful life events with emotion dysregulation and aggressive behavior. Structural equation modeling was used to create latent constructs of emotion dysregulation and aggression. Both stressful life events and peer victimization predicted subsequent increases in emotion dysregulation over a 4-month period. These increases in emotion dysregulation, in turn, were associated with increases in aggression over the subsequent 3 months. Longitudinal mediation models showed that emotion dysregulation mediated the relationship of both peer victimization (z = 2.35, p = 0.019) and stressful life events (z = 2.32, p = 0.020) with aggressive behavior. Increasing the use of adaptive emotion regulation strategies is an important target for interventions aimed at preventing the onset of adolescent aggressive behavior.

  5. Transgenerational effects of stress exposure on offspring phenotypes in apomictic dandelion.

    Directory of Open Access Journals (Sweden)

    Koen J F Verhoeven

    Full Text Available Heritable epigenetic modulation of gene expression is a candidate mechanism to explain parental environmental effects on offspring phenotypes, but current evidence for environment-induced epigenetic changes that persist in offspring generations is scarce. In apomictic dandelions, exposure to various stresses was previously shown to heritably alter DNA methylation patterns. In this study we explore whether these induced changes are accompanied by heritable effects on offspring phenotypes. We observed effects of parental jasmonic acid treatment on offspring specific leaf area and on offspring interaction with a generalist herbivore; and of parental nutrient stress on offspring root-shoot biomass ratio, tissue P-content and leaf morphology. Some of the effects appeared to enhance offspring ability to cope with the same stresses that their parents experienced. Effects differed between apomictic genotypes and were not always consistently observed between different experiments, especially in the case of parental nutrient stress. While this context-dependency of the effects remains to be further clarified, the total set of results provides evidence for the existence of transgenerational effects in apomictic dandelions. Zebularine treatment affected the within-generation response to nutrient stress, pointing at a role of DNA methylation in phenotypic plasticity to nutrient environments. This study shows that stress exposure in apomictic dandelions can cause transgenerational phenotypic effects, in addition to previously demonstrated transgenerational DNA methylation effects.

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

    Science.gov (United States)

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

    2016-05-01

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

  7. Transgenerational effects of stress exposure on offspring phenotypes in apomictic dandelion.

    Science.gov (United States)

    Verhoeven, Koen J F; van Gurp, Thomas P

    2012-01-01

    Heritable epigenetic modulation of gene expression is a candidate mechanism to explain parental environmental effects on offspring phenotypes, but current evidence for environment-induced epigenetic changes that persist in offspring generations is scarce. In apomictic dandelions, exposure to various stresses was previously shown to heritably alter DNA methylation patterns. In this study we explore whether these induced changes are accompanied by heritable effects on offspring phenotypes. We observed effects of parental jasmonic acid treatment on offspring specific leaf area and on offspring interaction with a generalist herbivore; and of parental nutrient stress on offspring root-shoot biomass ratio, tissue P-content and leaf morphology. Some of the effects appeared to enhance offspring ability to cope with the same stresses that their parents experienced. Effects differed between apomictic genotypes and were not always consistently observed between different experiments, especially in the case of parental nutrient stress. While this context-dependency of the effects remains to be further clarified, the total set of results provides evidence for the existence of transgenerational effects in apomictic dandelions. Zebularine treatment affected the within-generation response to nutrient stress, pointing at a role of DNA methylation in phenotypic plasticity to nutrient environments. This study shows that stress exposure in apomictic dandelions can cause transgenerational phenotypic effects, in addition to previously demonstrated transgenerational DNA methylation effects.

  8. 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

  9. Reactive Oxygen Species-mediated Loss of Phenotype of Parvalbumin Interneurons Contributes to Long-term Cognitive Impairments After Repeated Neonatal Ketamine Exposures.

    Science.gov (United States)

    Zhang, Hui; Sun, Xiao-Ru; Wang, Jing; Zhang, Zhen-Zhen; Zhao, Hong-Ting; Li, Hui-Hui; Ji, Mu-Huo; Li, Kuan-Yu; Yang, Jian-Jun

    2016-11-01

    Ketamine, a common anesthetic used for pediatric patients, has been shown to induce neurotoxicity and alter adolescent behaviors in rats when administered during neonatal period. However, the mechanisms underlying this kind of neurotoxicity remain largely to be determined. Herein, we studied whether the reactive oxygen species (ROS) due to the increased NOX2 mediates loss of phenotype of PV interneurons and thus contributes to long-term cognitive impairments after repeated ketamine exposures. Sprague-Dawley male rat pups received a daily administration of ketamine intraperitoneally (75 mg/kg) from postnatal day 6 (P6) to P8 for three consecutive days. For the interventional study, pups were treated with a NADPH oxidase inhibitor, apocynin (Apo). Learning and memory abilities were tested by the open field, fear conditioning, and Morris water maze on P40, P42-44, and P50-56, respectively. For histological and biochemical assays, a separate cohort of rats was killed on P9 or P60, and the brain tissues were harvested. Our results showed the upregulation of 8-OHdG and gp91/NOX2 and downregulation of PV and glutamic acid decarboxylase 67 (GAD67) after repeated ketamine exposures, which co-occurred with the long-term cognitive impairments as evidenced by the decreased freezing time to context. However, Apo treatment attenuated these abnormalities. Our results suggest that oxidative damage, probably due to the increased NOX2, mediates loss of phenotype of PV interneurons and thus contributes to long-term cognitive impairments after repeated ketamine exposures. Moreover, the inhibition of NADPH oxidase may protect against cognitive dysfunction.

  10. Personal PM2.5 exposure and markers of oxidative stress in blood

    DEFF Research Database (Denmark)

    Sørensen, Mettte; Daneshvar, Bahram; Hansen, Max

    2003-01-01

    found only in women (p oxidative stress and increase RBCs in peripheral blood. Personal exposure appears more...... and the involved mechanisms remain uncertain. We measured personal PM2.5 and carbon black exposure in 50 students four times in 1 year and analyzed blood samples for markers of protein and lipid oxidation, for red blood cell (RBC) and platelet counts, and for concentrations of hemoglobin and fibrinogen. We...... analyzed protein oxidation in terms of gamma-glutamyl semialdehyde in hemoglobin (HBGGS) and 2-aminoadipic semialdehyde in hemoglobin (HBAAS) and plasma proteins (PLAAS), and lipid peroxidation was measured as malondialdehyde (MDA) in plasma. Median exposures were 16.1 mug/m(3) for personal PM2.5 exposure...

  11. A decision support system for real-time stress detection during virtual reality exposure.

    Science.gov (United States)

    Gaggioli, Andrea; Cipresso, Pietro; Serino, Silvia; Pioggia, Giovanni; Tartarisco, Gennaro; Baldus, Giovanni; Corda, Daniele; Ferro, Marcello; Carbonaro, Nicola; Tognetti, Alessandro; De Rossi, Danilo; Giakoumis, Dimitris; Tzovaras, Dimitrios; Riera, Alejandro; Riva, Giuseppe

    2014-01-01

    Virtual Reality (VR) is increasingly being used in combination with psycho-physiological measures to improve assessment of distress in mental health research and therapy. However, the analysis and interpretation of multiple physiological measures is time consuming and requires specific skills, which are not available to most clinicians. To address this issue, we designed and developed a Decision Support System (DSS) for automatic classification of stress levels during exposure to VR environments. The DSS integrates different biosensor data (ECG, breathing rate, EEG) and behavioral data (body gestures correlated with stress), following a training process in which self-rated and clinical-rated stress levels are used as ground truth. Detected stress events for each VR session are reported to the therapist as an aggregated value (ranging from 0 to 1) and graphically displayed on a diagram accessible by the therapist through a web-based interface.

  12. A meta-analytic review of exposure in group cognitive behavioral therapy for posttraumatic stress disorder.

    Science.gov (United States)

    Barrera, T L; Mott, J M; Hofstein, R F; Teng, E J

    2013-02-01

    Although the efficacy of exposure is well established in individual cognitive behavioral treatments for posttraumatic stress disorder (PTSD), some clinicians and researchers have expressed concerns regarding the use of in-session disclosure of trauma details through imaginal exposure in group cognitive behavioral therapy (GCBT) for PTSD. Thus, the aim of the present study was to conduct a systematic review of the empirical support for GCBT in the treatment of PTSD and to compare GCBT protocols that encourage the disclosure of trauma details via in-session exposure to GCBT protocols that do not include in-session exposure. Randomized controlled trials that assessed the efficacy of GCBT for PTSD were included in the meta-analysis. A total of 651 participants with PTSD were included in the 12 eligible GCBT treatment conditions (5 conditions included in-group exposure, 7 conditions did not include in-group exposure). The overall pre-post effect size of GCBT for PTSD (ES=1.13 [SE=0.22, 95% CI: 0.69 to 1.56, pPTSD. No significant differences in effect sizes were found between GCBT treatments that included in-group exposure and those that did not. Although the attrition rate was higher in treatments that included exposure in-group, this rate is comparable to attrition rates in individual CBT treatments and pharmacotherapy for PTSD. The results from this meta-analysis suggest that concerns about the potentially negative impact of group exposure may be unwarranted, and support the use of exposure-based GCBT as a promising treatment option for PTSD.

  13. Ventilatory long-term facilitation is evident after initial and repeated exposure to intermittent hypoxia in mice genetically depleted of brain serotonin.

    Science.gov (United States)

    Hickner, Stephen; Hussain, Najaah; Angoa-Perez, Mariana; Francescutti, Dina M; Kuhn, Donald M; Mateika, Jason H

    2014-02-01

    Our study was designed to determine if central nervous system (CNS) serotonin is required for the induction of ventilatory long-term facilitation (LTF) in intact, spontaneously breathing mice. Nineteen tryptophan hydroxylase 2-deficient (Tph2(-/-)) mice, devoid of serotonin in the CNS, and their wild-type counterparts (Tph2(+/+)) were exposed to intermittent hypoxia each day for 10 consecutive days. The ventilatory response to intermittent hypoxia was greater in the Tph2(+/+) compared with the Tph2(-/-) mice (1.10 ± 0.10 vs. 0.77 ± 0.01 ml min(-1)·percent(-1) oxygen; P ≤ 0.04). Ventilatory LTF, caused by increases in breathing frequency, was evident in Tph2(+/+) and Tph2(-/-) mice following exposure to intermittent hypoxia each day; however, the magnitude of the response was greater in the Tph2(+/+) compared with the Tph2(-/-) mice (1.11 ± 0.02 vs. 1.05 ± 0.01 normalized to baseline on each day; P ≤ 0.01). The magnitude of ventilatory LTF increased significantly from the initial to the finals days of the protocol in the Tph2(-/-) (1.06 ± 0.02 vs. 1.11 ± 0.03 normalized to baseline on the initial days; P ≤ 0.004) but not in the Tph2(+/+) mice. This enhanced response was mediated by increases in tidal volume. Body temperature and metabolic rate did not account for differences in the magnitude of ventilatory LTF observed between groups after acute and repeated daily exposure to intermittent hypoxia. We conclude that ventilatory LTF, after acute exposure to intermittent hypoxia, is mediated by increases in breathing frequency and occurs in the absence of serotonin, although the magnitude of the response is diminished. This weakened response is enhanced following repeated daily exposure to intermittent hypoxia, via increases in tidal volume, to a similar magnitude evident in Tph2(+/+) mice. Thus the magnitude of ventilatory LTF following repeated daily exposure to intermittent hypoxia is not dependent on the presence of CNS serotonin.

  14. Interactive effects of early and recent exposure to stressful contexts on cortisol reactivity in middle childhood.

    Science.gov (United States)

    Jaffee, Sara R; McFarquhar, Tara; Stevens, Suzanne; Ouellet-Morin, Isabelle; Melhuish, Edward; Belsky, Jay

    2015-02-01

    Given mixed findings as to whether stressful experiences and relationships are associated with increases or decreases in children's cortisol reactivity, we tested whether a child's developmental history of risk exposure explained variation in cortisol reactivity to an experimentally induced task. We also tested whether the relationship between cortisol reactivity and children's internalizing and externalizing problems varied as a function of their developmental history of stressful experiences and relationships. Participants included 400 children (M = 9.99 years, SD = 0.74 years) from the Children's Experiences and Development Study. Early risk exposure was measured by children's experiences of harsh, nonresponsive parenting at 3 years. Recent risk exposure was measured by children's exposure to traumatic events in the past year. Children's cortisol reactivity was measured in response to a social provocation task and parents and teachers described children's internalizing and externalizing problems. The effect of recent exposure to traumatic events was partially dependent upon a child's early experiences of harsh, nonresponsive parenting: the more traumatic events children had recently experienced, the greater their cortisol reactivity if they had experienced lower (but not higher) levels of harsh, nonresponsive parenting at age 3. The lowest levels of cortisol reactivity were observed among children who had experienced the most traumatic events in the past year and higher (vs. lower) levels of harsh, nonresponsive parenting in early childhood. Among youth who experienced harsh, nonresponsive parent-child relationships in early childhood and later traumatic events, lower levels of cortisol reactivity were associated with higher levels of internalizing and externalizing problems. Hypothalamic-pituitary-adrenal (HPA) axis reactivity to psychological stressors and the relationship between HPA axis reactivity and children's internalizing and externalizing

  15. Postnatal exposure history and airways: oxidant stress responses in airway explants.

    Science.gov (United States)

    Murphy, Shannon R; Schelegle, Edward S; Edwards, Patricia C; Miller, Lisa A; Hyde, Dallas M; Van Winkle, Laura S

    2012-12-01

    Postnatally, the lung continues to grow and differentiate while interacting with the environment. Exposure to ozone (O(3)) and allergens during postnatal lung development alters structural elements of conducting airways, including innervation and neurokinin abundance. These changes have been linked with development of asthma in a rhesus monkey model. We hypothesized that O(3) exposure resets the ability of the airways to respond to oxidant stress and that this is mediated by changes in the neurokinin-1 receptor (NK-1R). Infant rhesus monkeys received episodic exposure to O(3) biweekly with or without house dust mite antigen (HDMA) from 6 to 12 months of age. Age-matched monkeys were exposed to filtered air (FA). Microdissected airway explants from midlevel airways (intrapulmonary generations 5-8) for four to six animals in each of four groups (FA, O(3), HDMA, and HDMA+O(3)) were tested for NK-1R gene responses to acute oxidant stress using exposure to hydrogen peroxide (1.2 mM), a lipid ozonide (10 μM), or sham treatment for 4 hours in vitro. Airway responses were measured using real-time quantitative RT-PCR of NK-1R and IL-8 gene expression. Basal NK-1R gene expression levels were not different between the exposure groups. Treatment with ozonide or hydrogen peroxide did not change NK-1R gene expression in animals exposed to FA, HDMA, or HDMA+O(3). However, treatment in vitro with lipid ozonide significantly increased NK-1R gene expression in explants from O(3)-exposed animals. We conclude that a history of prior O(3) exposure resets the steady state of the airways to increase the NK-1R response to subsequent acute oxidant stresses.

  16. Israeli adolescents with ongoing exposure to terrorism: suicidal ideation, posttraumatic stress disorder, and functional impairment.

    Science.gov (United States)

    Chemtob, Claude M; Pat-Horenczyk, Ruth; Madan, Anita; Pitman, Seth R; Wang, Yanping; Doppelt, Osnat; Burns, Kelly Dugan; Abramovitz, Robert; Brom, Daniel

    2011-12-01

    In this study, we examined the relationships among terrorism exposure, functional impairment, suicidal ideation, and probable partial or full posttraumatic stress disorder (PTSD) from exposure to terrorism in adolescents continuously exposed to this threat in Israel. A convenience sample of 2,094 students, aged 12 to 18, was drawn from 10 Israeli secondary schools. In terms of demographic factors, older age was associated with increased risk for suicidal ideation, OR = 1.33, 95% CI [1.09, 1.62], p terrorism was associated with increased risk for each of the measured outcomes including probable partial or full PTSD, functional impairment, and suicidal ideation. When age, gender, level of exposure to terrorism, probable partial or full PTSD, and functional impairment were examined together, only terrorism exposure and functional impairment were associated with suicidal ideation. This study underscores the importance and feasibility of examining exposure to terrorism and functional impairment as risk factors for suicidal ideation. Copyright © 2011 International Society for Traumatic Stress Studies.

  17. Heat stress and sudden infant death syndrome-Stress gene expression after exposure to moderate heat stress

    DEFF Research Database (Denmark)

    Rohde, Marianne Cathrine; Corydon, Thomas Juhl; Hansen, Jakob

    2013-01-01

    The aim of the present study was to investigate stress gene expression in cultured primary fibroblasts established from Achilles tendons collected during autopsies from sudden infant death syndrome (SIDS) cases, and age-matched controls (infants dying in a traumatic event). Expression of 4 stress...... studies using cultured fibroblasts established from deceased individuals as a tool for molecular and pathological investigations in forensic and biomedical sciences....

  18. Biomarkers of oxidative stress and inflammation after wood smoke exposure in a reconstructed Viking Age house

    DEFF Research Database (Denmark)

    Jensen, Annie; Karottki, Dorina Gabriela; Christensen, Jannie Marie

    2014-01-01

    dehydrogenase, cholesterol, triglycerides, and high-density lipoproteins. The wood smoke exposure was associated with decreased serum levels of sICAM-1, and a tendency to decreased sVCAM-1 levels. There was a minor increase in the levels of circulating monocytes expressing CD31, whereas there were unaltered...... expression levels of CD11b, CD49d, and CD62L on monocytes after the stay in the house. In conclusion, even a high inhalation exposure to wood smoke was associated with limited systemic effects on markers of oxidative stress, DNA damage, inflammation, and monocyte activation....

  19. Transcriptional response of stress genes to metal exposure in zebra mussel larvae and adults

    Energy Technology Data Exchange (ETDEWEB)

    Navarro, Anna; Faria, Melissa; Barata, Carlos [Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18, 08034 Barcelona (Spain); Pina, Benjamin, E-mail: bpcbmc@cid.csic.e [Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18, 08034 Barcelona (Spain)

    2011-01-15

    Development of stress markers for the invader freshwater zebra mussel (Dreissena polymorpha) is of great interest for both conservation and biomonitoring purposes. Gene expression profiles of several putative or already established gene expression stress markers (Metallothionein, Superoxide dismutase, Catalase, Glutathione S transferase, Glutathione peroxidase, Cytochrome c oxidase, the multixenobiotic resistance P-gp1, and heat shock proteins HSP70 and HSP90) were analyzed by quantitative Real-Time PCR in adults and pediveliger larvae after exposure to metals (Hg, Cu, Cd). A defined pattern of coordinated responses to metal exposure and, presumably, to oxidative stress was observed in gills and digestive gland from adults. A similar, albeit partial response was observed in larvae, indicating an early development of stress-related gene responses in zebra mussel. The tools developed in this study may be useful both for future control strategies and for the use of zebra mussel as sentinel species in water courses with stable populations. - Coordinated expression of stress genes in zebra mussel.

  20. 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

    J mice were exposed four times during gestation by intratracheal instillation of 67μg/animal of nanosized carbon black Printex90 or vehicle (gestation days 7, 10, 15 and 18). Female offspring were raised to maturity and mated with unexposed CBA males. Expanded simple tandem repeat (ESTR) germline...... 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....

  1. Organism/Organic Exposure to Orbital Stresses (OOREOS) Satellite: Radiation Exposure in LEO and Supporting Laboratory Studies

    Science.gov (United States)

    Mattioda, Andrew Lige; Cook, Amanda Marie; Quinn, Richard C.; Elsaesser, Andreas; Ehrenfreund, Pascale; Ricca,Alessandra; Jones, Nykola C.; Hoffman, Soren; Ricco,Antonio

    2014-01-01

    We will present the results from the exposure of the metalloporphyrin iron tetraphenylporphyrin chloride (FeTPPCI), anthraufin (C(sub 14)H(sub 8)(O sub 4) (Anth) and Isoviolanthrene (C(sub 34H sub 18) (IVA) to the outher space environment, measured in situ aboard the Organism/Organic Exposure to Orbital Stresses nanosatellite. The compounds were exposed for a period of 17 months (3700 hours of direct solar exposure) including broad-spectrum solar radiation (approx. 122 nm to the near infrared). The organic films are enclosed in hermetically sealed sample cells that contain one of four astrobiologically relevant microenvironments. Transmission spectra (200-1000 nm) were recorded for each film, at first daily and subsequently every 15 days, along with a solar spectrum and the dark response of the detector array. In addition to analysis via UV-Vis spectroscopy, the laboratory controls were also monitored via infrared and far-UV spectroscopy. The results presented will include the finding that the FeTPPCI and IVA organic films in contact with a humid headspace gas (0.8-2.3%) exhibit faster degradation times, upon irradiation, in comparison with identical films under dry headspaces gases, whereas the Anth thin film exhibited a higher degree of photostability. In the companion laboratory experiments, simulated solar exposure of FeTPI films in contact with either Ar or CO(sub -2):O(sub -2):Ar (10:0.01:1000) headspace gas results in growth of a band in the films infrared spectra at 1961 cm(sup 1). Our assignment of this new spectral feature and the corresponding rational will be presented. The relevance of O/OREOS findings to planetary science, biomarker research, and the photostability of organic materials in astrobiologically relevant environments will also be discussed.

  2. Expression of nuclear factor-kappa B in hepatic tissue and its significance in rats after repeated and sustained +10Gz exposure

    Directory of Open Access Journals (Sweden)

    Lei LIU

    2015-07-01

    Full Text Available Objective To observe the injury to liver cells, and to investigate the changes in nuclear factor-kappa B (NF-κB in the liver tissue after exposure to positive ten acceleration (+10Gz. Methods Twenty-four adult male Wistar rats were randomly assigned to four groups: blank control, exposure groups A, B, and C. The rats of three exposure groups were subjected to centrifugal force of +10Gz for 0.5, 24, and 48h respectively, which was carried out in an Air Force Institute of Aviation Medicine. Plasma aspartate aminotransferase (AST and alanine aminotransferase (ALT were determined. Liver tissue was harvested for immunohistochemistry, and Western blotting was performed for expression of NF-κB. Results After +10 Gz exposure, rats of the group A showed shaggy hair, apathetic to food, and laid still, while group B rats showed shaggy hair, took a little food with lowering of activity level. The rats in group C showed normal activities. Both the levels of serum AST and ALT were elevated, and they were higher in group B than that of groups A and C (P0.05. Western blotting and immunohistochemical staining showed that the NF-κB expression levels were significantly higher in exposure groups than in control group (P0.05. Immunohistochemical examination revealed NF-κBpositive products were localized predominantly in the hepatocytes, and also in the inflammatory cells and Kupffer cells. These products could be divided into three types: cytosolic type, karyotype, and nuclear-cytoplasm type, and they existed alone or in combination. Conclusion Exposure to +10Gz, especially in the early stage, acts as a stress to induce the activation of NF-κB, suggesting that NF-κB plays an important role in the cascade reactions and adaptation to the acceleration stress. DOI: 10.11855/j.issn.0577-7402.2015.07.17

  3. Enhanced hepatotoxicity induced by repeated exposure to polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin in combination in male rats

    Institute of Scientific and Technical Information of China (English)

    Yimei Wang; Chunfeng Lu; Zhiguo Sheng; Gang Liu; Ze Fu; Benzhan Zhu; Shuangqing Peng

    2011-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls (PCBs) are among persistent polyhalogenated aromatic hydrocarbons that exist as complex mixtures in the environment worldwide. The present study was attempted to investigate the hepatotoxicity following repeated exposure to TCDD and PCBs in combination in male rats, and to reveal the involvement of potential mechanisms. Male Sprague-Dawley rats were exposed to TCDD (10 μg/kg) and Aroclor 1254 (10 mg/kg, a representative mixture of PCBs) alone or in combination by intragastric administration. After 12-day exposure, all treatments produced significant hepatotoxicity as characterized by changes of plasma biochemistry and histopathological changes. These effects were more prominent in the combined group. Furthermore, all treatments induced hepatic cytochrome P450 1A1 (CYP1A1) expression, and the maximal level of CYP1A1 expression was observed in the combined group, as in the case of the most severe hepatotoxicity evoked by the combined exposure.These findings indicated that the hepatotoxicity induced by TCDD and Aroclor 1254 might be ascribed to the high expression of hepatic CYP1A1. The present study demonstrates the enhanced hepatotoxicity after exposure to TCDD and PCBs in combination in rats.

  4. An integrated approach to biomonitoring exposure to styrene and styrene-(7,8)-oxide using a repeated measurements sampling design.

    Science.gov (United States)

    Fustinoni, S; Campo, L; Manini, P; Buratti, M; Waidyanatha, S; De Palma, G; Mutti, A; Foa, V; Colombi, A; Rappaport, S M

    2008-09-01

    The aim of this work was to investigate urinary analytes and haemoglobin and albumin adducts as biomarkers of exposure to airborne styrene (Sty) and styrene-(7,8)-oxide (StyOX) and to evaluate the influence of smoking habit and genetic polymorphism of metabolic enzymes GSTM1 and GSTT1 on these biomarkers. We obtained three or four air and urine samples from each exposed worker (eight reinforced plastics workers and 13 varnish workers), one air and urine samples from 22 control workers (automobile mechanics) and one blood sample from all subjects. Median levels of exposure to Sty and StyOX, respectively, were 18.2 mg m(-3) and 133 microg m(-3) for reinforced plastics workers, 3.4 mg m(-3) and 12 microg m(-3) for varnish workers, and <0.3 mg m(-3) and <5 microg m(-3) for controls. Urinary levels of styrene, mandelic acid, phenylglyoxylic acid, phenylglycine (PHG), 4-vinylphenol (VP) and mercapturic acids (M1+M2), as well as cysteinyl adducts of serum albumin (but not those of haemoglobin) were significantly associated with exposure status (controlsexposure, suggestive of saturable metabolism. Levels of the protein adducts were not associated with exposure to either Sty or StyOX among exposed subjects.

  5. Oxidative stress generated damage to DNA by gastrointestinal exposure to insoluble particles

    DEFF Research Database (Denmark)

    Møller, Peter; Folkmann, J K; Danielsen, P H

    2012-01-01

    There is growing concern that gastrointestinal exposure to particles is associated with increased risk of toxicity to internal organs and carcinogenicity. The mechanism of action is related to particle-induced oxidative stress and oxidation of DNA. Observations from animal models indicate...... level of lipid peroxidation derived exocyclic DNA adducts in the liver, suggesting multiple pathways of oxidative stress for particle-generated damage to DNA. At equal dose, diesel exhaust particles (SRM2975) generated larger levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine in rat liver than carbon black...... to particulate matter is associated with oxidative damage to DNA and this might be associated with increased risk of cancer....

  6. 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/

  7. Involvement of Oxidative Stress and Inflammation in Liver Injury Caused by Perfluorooctanoic Acid Exposure in Mice

    Directory of Open Access Journals (Sweden)

    Bei Yang

    2014-01-01

    Full Text Available Perfluorooctanoic acid (PFOA is widely present in the environment and has been reported to induce hepatic toxicity in animals and humans. In this study, mice were orally administered different concentrations of PFOA (2.5, 5, or 10 mg/kg/day. Histological examination showed that the exposure to PFOA for 14 consecutive days led to serious hepatocellular injury and obvious inflammatory cell infiltration. In addition, malondialdehyde formation and hydrogen peroxide generation, indicators of oxidative stress, were significantly induced by PFOA treatment in the liver of mice. Furthermore, hepatic levels of interleukin-6, cyclooxygenase-2, and C-reactive protein, markers of inflammatory response, were markedly increased by exposure to PFOA in mice. These results demonstrated that PFOA-induced hepatic toxicity may be involved in oxidative stress and inflammatory response in mice.

  8. Dexmedetomidine attenuates repeated propofol exposure-induced hippocampal apoptosis, PI3K/Akt/Gsk-3β signaling disruption, and juvenile cognitive deficits in neonatal rats.

    Science.gov (United States)

    Wang, Yujie; Wu, Changyi; Han, Bin; Xu, Fei; Mao, Mingfeng; Guo, Xiangyang; Wang, Jun

    2016-07-01

    Propofol is one of the most widely used intravenous anesthetics. However, repeated exposure to propofol may cause neurodegeneration in the developing brain. Dexmedetomidine (Dex), an α2 adrenoceptor agonist, has been previously demonstrated to provide neuroprotection against neuroapoptosis and neurocognitive impairments induced by several anesthetics. Thus, the current study aimed to investigate the effect of Dex on neonatal propofol-induced neuroapoptosis and juvenile spatial learning/memory deficits. Propofol (30 mg/kg) was intraperiotoneally administered to 7‑day‑old Sprague Dawley rats (n=75) three times each day at 90 min intervals for seven consecutive days with or without Dex (75 µg/kg) treatment 20 min prior to propofol injection. Following repeated propofol exposure, reduced Akt and GSK‑3β phosphorylation, increased cleaved caspase‑3 expression levels, an increased Bax/Bcl‑2 ratio, and increased terminal deoxynucleotidyl transferase‑mediated dUTP nick‑end labeling (TUNEL)‑positive cells in the CA1 hippocampal subregion were observed. Morris Water Maze testing at postnatal day 29 also demonstrated spatial learning and memory deficits following propofol treatment compared with the control group. Notably, these changes were significantly attenuated by Dex pretreatment. The results of the current study demonstrated that Dex ameliorates the neurocognitive impairment induced by repeated neonatal propofol challenge in rats, partially via its anti‑apoptotic action and normalization of the disruption to the PI3K/Akt/GSK‑3β signaling pathway. The present study provides preliminary evidence demonstrating the safety of propofol on the neonatal brain and the potential use of dexmedetomidine pretreatment in pediatric patients.

  9. Exposure to prenatal psychobiological stress exerts programming influences on the mother and her fetus.

    Science.gov (United States)

    Sandman, Curt A; Davis, Elysia P; Buss, Claudia; Glynn, Laura M

    2012-01-01

    Accumulating evidence from a relatively small number of prospective studies indicates that exposure to prenatal stress profoundly influences the developing human fetus with consequences that persist into childhood and very likely forever. Maternal/fetal dyads are assessed at ∼20, ∼25, ∼31 and ∼36 weeks of gestation. Infant assessments begin 24 h after delivery with the collection of cortisol and behavioral responses to the painful stress of the heel-stick procedure and measures of neonatal neuromuscular maturity. Infant cognitive, neuromotor development, stress and emotional regulation are evaluated at 3, 6 12 and 24 months of age. Maternal psychosocial stress and demographic information is collected in parallel with infant assessments. Child neurodevelopment is assessed with cognitive tests, measures of adjustment and brain imaging between 5 and 8 years of age. Psychobiological markers of stress during pregnancy, especially early in gestation, result in delayed fetal maturation, disrupted emotional regulation and impaired cognitive performance during infancy and decreased brain volume in areas associated with learning and memory in 6- to 8-year-old children. We review findings from our projects that maternal endocrine alterations that accompany pregnancy and influence fetal/infant/child development are associated with decreased affective responses to stress, altered memory function and increased risk for postpartum depression. Our findings indicate that the mother and her fetus both are influenced by exposure to psychosocial and biological stress. The findings that fetal and maternal programming occur in parallel may have important implications for long-term child development and mother/child interactions. Copyright © 2011 S. Karger AG, Basel.

  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. Scrambled and fried: Cigarette smoke exposure causes antral follicle destruction and oocyte dysfunction through oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Sobinoff, A.P. [Reproductive Science Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308 (Australia); Priority Research Centre for Chemical Biology, University of Newcastle, Callaghan, NSW 2308 (Australia); Beckett, E.L.; Jarnicki, A.G. [Centre for Asthma and Respiratory Disease, The University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW 2308 (Australia); Sutherland, J.M. [Reproductive Science Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308 (Australia); Priority Research Centre for Chemical Biology, University of Newcastle, Callaghan, NSW 2308 (Australia); McCluskey, A. [Priority Research Centre for Chemical Biology, University of Newcastle, Callaghan, NSW 2308 (Australia); Hansbro, P.M. [Centre for Asthma and Respiratory Disease, The University of Newcastle and Hunter Medical Research Institute, Callaghan, NSW 2308 (Australia); McLaughlin, E.A., E-mail: eileen.mclaughlin@newcastle.edu.au [Reproductive Science Group, School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308 (Australia); Priority Research Centre for Chemical Biology, University of Newcastle, Callaghan, NSW 2308 (Australia)

    2013-09-01

    Cigarette smoke is a reproductive hazard associated with pre-mature reproductive senescence and reduced clinical pregnancy rates in female smokers. Despite an increased awareness of the adverse effects of cigarette smoke exposure on systemic health, many women remain unaware of the adverse effects of cigarette smoke on female fertility. This issue is compounded by our limited understanding of the molecular mechanisms behind cigarette smoke induced infertility. In this study we used a direct nasal exposure mouse model of cigarette smoke-induced chronic obstructive pulmonary disease to characterise mechanisms of cigarette-smoke induced ovotoxicity. Cigarette smoke exposure caused increased levels of primordial follicle depletion, antral follicle oocyte apoptosis and oxidative stress in exposed ovaries, resulting in fewer follicles available for ovulation. Evidence of oxidative stress also persisted in ovulated oocytes which escaped destruction, with increased levels of mitochondrial ROS and lipid peroxidation resulting in reduced fertilisation potential. Microarray analysis of ovarian tissue correlated these insults with a complex mechanism of ovotoxicity involving genes associated with detoxification, inflammation, follicular activation, immune cell mediated apoptosis and membrane organisation. In particular, the phase I detoxifying enzyme cyp2e1 was found to be significantly up-regulated in developing oocytes; an enzyme known to cause molecular bioactivation resulting in oxidative stress. Our results provide a preliminary model of cigarette smoke induced sub-fertility through cyp2e1 bioactivation and oxidative stress, resulting in developing follicle depletion and oocyte dysfunction. - Highlights: • Cigarette smoke exposure targets developing follicle oocytes. • The antral follicle oocyte is a primary site of ovarian cigarette smoke metabolism. • Cyp2e1 is a major enzyme involved in ameliorating smoke-induced ovotoxicity. • Cigarette smoke causes oocyte

  12. Transgenerational Effects of Stress Exposure on Offspring Phenotypes in Apomictic Dandelion

    OpenAIRE

    Koen J F Verhoeven; Thomas P van Gurp

    2012-01-01

    Heritable epigenetic modulation of gene expression is a candidate mechanism to explain parental environmental effects on offspring phenotypes, but current evidence for environment-induced epigenetic changes that persist in offspring generations is scarce. In apomictic dandelions, exposure to various stresses was previously shown to heritably alter DNA methylation patterns. In this study we explore whether these induced changes are accompanied by heritable effects on offspring phenotypes. We o...

  13. The E-subgroup Pentatricopeptide Repeat Protein family in Arabidopsis thaliana and confirmation of the responsiveness PPR96 to abiotic stresses

    Directory of Open Access Journals (Sweden)

    Jia-Ming Liu

    2016-12-01

    Full Text Available Pentatricopeptide repeat (PPR proteins are extensive in all eukaryotes. Their functions remain as yet largely unknown. Mining potential stress responsive PPRs, and checking whether known PPR editing factors are affected in the stress treatments. It is beneficial to elucidate the regulation mechanism of PPRs involved in biotic and abiotic stress. Here, we explored the characteristics and origin of the 105 E subgroup PPRs in Arabidopsis thaliana. Phylogenetic analysis categorized the E subgroup PPRs into five discrete groups (Cluster I to V, and they may have a common origin in both A. thaliana and rice. An in silico expression analysis of the 105 E subgroup PPRs in A. thaliana was performed using available microarray data. 34 PPRs were differentially expressed during A. thaliana seed imbibition, seed development stage(s, and flowers development processes. To explore potential stress responsive PPRs, differential expression of 92 PPRs was observed in A. thaliana seedlings subjected to different abiotic stresses. qPCR data of E subgroup PPRs under stress conditions revealed that the expression of 5 PPRs was responsive to abiotic stresses. In addition, PPR96 is involved in plant responses to salt, abscisic acid (ABA, and oxidative stress. The T-DNA insertion mutation inactivating PPR96 expression results in plant insensitivity to salt, ABA, and oxidative stress. The PPR96 protein is localized in the mitochondria, and altered transcription levels of several stress-responsive genes under abiotic stress treatments. Our results suggest that PPR96 may important function in a role connecting the regulation of oxidative respiration and environmental responses in A. thaliana.

  14. Childhood antecedents of exposure to traumatic events and posttraumatic stress disorder.

    Science.gov (United States)

    Storr, Carla L; Ialongo, Nicholas S; Anthony, James C; Breslau, Naomi

    2007-01-01

    The authors prospectively examined childhood antecedents of exposure to traumatic events to estimate the risk of posttraumatic stress disorder (PTSD) among those exposed to trauma. Two consecutive cohorts of children entering first grade of a public school system in a large mid-Atlantic city in the mid-1980s were followed into young adulthood (mean age=21). Exposure to traumatic events and PTSD were assessed in 75% of the original cohort (N=1,698). Childhood assessments, conducted upon entry into the first grade, included standardized measures of reading readiness, teacher ratings of behavioral problems, and child self-reports about depression and anxiety. Family characteristics were assessed by parental report. Young adults who had been rated by their first grade teacher as having aggressive/disruptive behavior problems were more likely to experience traumatic assaultive violence events (e.g., being mugged/threatened with a weapon, badly beaten-up) (relative risk=2.6) but not PTSD following trauma exposure. Youths with high levels of self-rated depressive and anxious feelings in first grade were more likely to experience PTSD once exposed to trauma (relative risk=1.5). Youths who scored in the highest quartile on a reading test in the first grade were at lower risk for exposure to assaultive violence traumas. Childhood behavioral and depressive/anxious problems may influence the risk for PTSD directly by increasing the vulnerability to the PTSD effects of trauma exposure, and indirectly by increasing the likelihood of exposure to assaultive violence.

  15. Neuronal cellular responses to extremely low frequency electromagnetic field exposure: implications regarding oxidative stress and neurodegeneration.

    Science.gov (United States)

    Reale, Marcella; Kamal, Mohammad A; Patruno, Antonia; Costantini, Erica; D'Angelo, Chiara; Pesce, Miko; Greig, Nigel H

    2014-01-01

    Neurodegenerative diseases comprise both hereditary and sporadic conditions characterized by an identifying progressive nervous system dysfunction and distinctive neuopathophysiology. The majority are of non-familial etiology and hence environmental factors and lifestyle play key roles in their pathogenesis. The extensive use of and ever increasing worldwide demand for electricity has stimulated societal and scientific interest on the environmental exposure to low frequency electromagnetic fields (EMFs) on human health. Epidemiological studies suggest a positive association between 50/60-Hz power transmission fields and leukemia or lymphoma development. Consequent to the association between EMFs and induction of oxidative stress, concerns relating to development of neurodegenerative diseases, such as Alzheimer disease (AD), have been voiced as the brain consumes the greatest fraction of oxygen and is particularly vulnerable to oxidative stress. Exposure to extremely low frequency (ELF)-EMFs are reported to alter animal behavior and modulate biological variables, including gene expression, regulation of cell survival, promotion of cellular differentiation, and changes in cerebral blood flow in aged AD transgenic mice. Alterations in inflammatory responses have also been reported, but how these actions impact human health remains unknown. We hence evaluated the effects of an electromagnetic wave (magnetic field intensity 1 mT; frequency, 50-Hz) on a well-characterized immortalized neuronal cell model, human SH-SY5Y cells. ELF-EMF exposure elevated the expession of NOS and O2(-), which were countered by compensatory changes in antioxidant catylase (CAT) activity and enzymatic kinetic parameters related to CYP-450 and CAT activity. Actions of ELF-EMFs on cytokine gene expression were additionally evaluated and found rapidly modified. Confronted with co-exposure to H2O2-induced oxidative stress, ELF-EMF proved not as well counteracted and resulted in a decline in CAT

  16. Prenatal glucocorticoid exposure in rats: programming effects on stress reactivity and cognition in adult offspring.

    Science.gov (United States)

    Zeng, Yan; Brydges, Nichola M; Wood, Emma R; Drake, Amanda J; Hall, Jeremy

    2015-01-01

    Human epidemiological studies have provided compelling evidence that prenatal exposure to stress is associated with significantly increased risks of developing psychiatric disorders in adulthood. Exposure to excessive maternal glucocorticoids may underlie this fetal programming effect. In the current study, we assessed how prenatal dexamethasone administration during the last week of gestation affects stress reactivity and cognition in adult offspring. Stress reactivity was assessed by evaluating anxiety-like behavior on an elevated plus maze and in an open field. In addition, to characterize the long-term cognitive outcomes of prenatal exposure to glucocorticoids, animals were assessed on two cognitive tasks, a spatial reference memory task with reversal learning and a delayed matching to position (DMTP) task. Our results suggest that prenatal exposure to dexamethasone had no observable effect on anxiety-like behavior, but affected cognition in the adult offspring. Prenatally dexamethasone-exposed animals showed a transient deficit in the spatial reference memory task and a trend to faster acquisition during the reversal-learning phase. Furthermore, prenatally dexamethasone-treated animals also showed faster learning of new platform positions in the DMTP task. These results suggest that fetal overexposure to glucocorticoids programs a phenotype characterized by cognitive flexibility and adaptability to frequent changes in environmental circumstances. This can be viewed as an attempt to increase the fitness of survival in a potentially hazardous postnatal environment, as predicted by intrauterine adversity. Collectively, our data suggest that prenatal exposure to dexamethasone in rats could be used as an animal model for studying some cognitive components of related psychiatric disorders.

  17. Exposure to 1-bromopropane induces microglial changes and oxidative stress in the rat cerebellum.

    Science.gov (United States)

    Subramanian, Kaviarasan; Mohideen, Sahabudeen Sheik; Suzumura, Akio; Asai, Naoya; Murakumo, Yoshiki; Takahashi, Masahide; Jin, Shijie; Zhang, Lingyi; Huang, Zhenlie; Ichihara, Sahoko; Kitoh, Junzoh; Ichihara, Gaku

    2012-12-08

    1-Bromopropane (1-BP), an alternative to ozone-depleting solvents, is reported to exhibit neurotoxicity and reproductive toxicity in animals and humans. However, the underlying mechanism of the toxicity remains elusive. This study was designed to identify the microglial changes and oxidative stress in the central nervous system (CNS) after 1-BP exposure. Four groups of Wistar-ST rats (n=12 each) were exposed to 0, 400, 800 and 1000ppm of 1-BP, 8h/day for 28 consecutive days. The cerebellum was dissected out in 9 rats of each group and subjected to biochemical analysis, while the brains of the remaining 3 rats were examined immunohistochemically. Exposure to 1-BP increased the levels of oxidative stress markers [thiobarbituric acid reactive substances (TBARS), protein carbonyl and reactive oxygen species (ROS)] in a dose-dependent manner. Likewise, there was also 1-BP dose-dependent increase in nitric oxide (NO) and dose-dependent decrease in protein concentrations in the cerebellum. Immunohistochemical studies showed 1-BP-induced increase in cd11b/c-positive microglia area in the white matter of the cerebellar hemispheres. The results showed that exposure to 1-BP induced morphological change in the microglia and oxidative stress, suggesting that these effects are part of the underlying neurotoxic mechanism of 1-BP in the CNS.

  18. Impact of antenatal synthetic glucocorticoid exposure on endocrine stress reactivity in term-born children.

    Science.gov (United States)

    Alexander, Nina; Rosenlöcher, Franziska; Stalder, Tobias; Linke, Julia; Distler, Wolfgang; Morgner, Joachim; Kirschbaum, Clemens

    2012-10-01

    Antenatal glucocorticoid (GC) exposure has been discussed as a potent programming factor of hypothalamus-pituitary-adrenal (HPA) axis activity, producing sustained alterations in cortisol secretion throughout life. So far, the assessment of HPA-axis activity in offspring of mothers treated with synthetic GC has been limited to a time period shortly after birth, with prematurity being an important confound in most prior studies. The present study aimed to investigate HPA-axis reactivity of term-born children with antenatal GC exposure in a larger sample, allowing us to further address sex- and drug-specific effects. This was a cross-sectional study comprised of 209 term-born children between 6 and 11 yr of age. Cortisol secretion patterns in response to a standardized laboratory stressor (Trier Social Stress Test for Children) were assessed in children with antenatal GC exposure (a single course of either dexamethasone or betamethasone) and compared to different control groups. We observed significantly increased cortisol reactivity to acute psychosocial stress in 6- to 11-yr-old, term-born children exposed to antenatal synthetic GC treatment compared to controls (F(3.4,345.9)=5.8; Pchildren. These findings may bear important implications regarding the vulnerability for stress-related physical and psychiatric disorders, for which dysregulation of the HPA-axis has been discussed as a potential causal factor.

  19. Childhood maltreatment, 9/11 exposure, and latent dimensions of psychopathology: A test of stress sensitization.

    Science.gov (United States)

    Meyers, Jacquelyn L; Lowe, Sarah R; Eaton, Nicholas R; Krueger, Robert; Grant, Bridget F; Hasin, Deborah

    2015-09-01

    On September 11, 2001, a terrorist attack occurred in the U.S. (9/11). Research on 9/11 and psychiatric outcomes has focused on individual disorders rather than the broader internalizing (INT) and externalizing (EXT) domains of psychopathology, leaving unknown whether direct and indirect 9/11 exposure differentially impacted these domains rather than individual disorders. Further, whether such effects were exacerbated by earlier childhood maltreatment (i.e. stress sensitization) is unknown. 18,713 participants from a U.S. national sample with no history of psychiatric disorders prior to 9/11 were assessed using a structured in-person interview. Structural equation modeling conducted in a sample who endorsed no psychiatric history prior to 9/11, indicated that indirect exposure to 9/11 (i.e. media, friends/family) was related to both EXT (alcohol, nicotine, and cannabis dependence, and antisocial personality disorder) and INT (major depression, generalized anxiety, and post-traumatic stress disorder (PTSD)) dimensions of psychopathology (EXT: β = 0.10, p childhood maltreatment, the risk for EXT and INT dimensions associated with 9/11 was exacerbated (Interactions: β = 0.06, p psychopathology in the US general population rather than specific disorders with the exception of PTSD, which had independent effects beyond INT (as indicated by a significant (p childhood maltreatment increases the risk associated with adult trauma exposure, providing further evidence for the concept of stress sensitization.

  20. Low Vagal Tone Magnifies the Association Between Psychosocial Stress Exposure and Internalizing Psychopathology in Adolescents

    Science.gov (United States)

    McLaughlin, Katie A.; Rith-Najarian, Leslie; Dirks, Melanie A.; Sheridan, Margaret A.

    2014-01-01

    Vagal tone is a measure of cardiovascular function that facilitates adaptive responses to environmental challenge. Low vagal tone is associated with poor emotional and attentional regulation in children and has been conceptualized as a marker of sensitivity to stress. We investigated whether the associations of a wide range of psychosocial stressors with internalizing and externalizing psychopathology were magnified in adolescents with low vagal tone. Resting heart period data were collected from a diverse community sample of adolescents (ages 13–17; N =168). Adolescents completed measures assessing internalizing and externalizing psychopathology and exposure to stressors occurring in family, peer, and community contexts. Respiratory sinus arrhythmia (RSA) was calculated from the interbeat interval time series. We estimated interactions between RSA and stress exposure in predicting internalizing and externalizing symptoms and evaluated whether interactions differed by gender. Exposure to psychosocial stressors was associated strongly with psychopathology. RSA was unrelated to internalizing or externalizing problems. Significant interactions were observed between RSA and child abuse, community violence, peer victimization, and traumatic events in predicting internalizing but not externalizing symptoms. Stressors were positively associated with internalizing symptoms in adolescents with low RSA but not in those with high RSA. Similar patterns were observed for anxiety and depression. These interactions were more consistently observed for male than female individuals. Low vagal tone is associated with internalizing psychopathology in adolescents exposed to high levels of stressors. Measurement of vagal tone in clinical settings might provide useful information about sensitivity to stress in child and adolescent clients. PMID:24156380

  1. Repeated exposure of adolescent rats to oral methylphenidate does not induce behavioral sensitization or cross-sensitization to nicotine

    Directory of Open Access Journals (Sweden)

    C.C. Justo

    2010-07-01

    Full Text Available Several lines of evidence indicate that the use of stimulant drugs, including methylphenidate (MPD, increases tobacco smoking. This has raised concerns that MPD use during adolescence could facilitate nicotine abuse. Preclinical studies have shown that repeated treatment with an addictive drug produces sensitization to that drug and usually cross-sensitization to other drugs. Behavioral sensitization has been implicated in the development of drug addiction. We examined whether repeated oral MPD administration during adolescence could induce behavioral sensitization to MPD and long-lasting cross-sensitization to nicotine. Adolescent male Wistar rats were treated orally with 10 mg/kg MPD or saline (SAL from postnatal day (PND 27 to 33. To evaluate behavioral sensitization to MPD in adolescent rats (PND 39, the SAL pretreated group was subdivided into two groups that received intragastric SAL (1.0 mL/kg or MPD (10 mg/kg; MPD pretreated rats received MPD (10 mg/kg. Cross-sensitization was evaluated on PND 39 or PND 70 (adulthood. To this end, SAL- and MPD-pretreated groups received subcutaneous injections of SAL (1.0 mL/kg or nicotine (0.4 mg/kg. All groups had 8 animals. Immediately after injections, locomotor activity was determined. The locomotor response to MPD challenge of MPD-pretreated rats was not significantly different from that of the SAL-pretreated group. Moreover, the locomotor response of MPD-pretreated rats to nicotine challenge was not significantly different from that of the SAL-pretreated group. This lack of sensitization and cross-sensitization suggests that MPD treatment during adolescence does not induce short- or long-term neuroadaptation in rats that could increase sensitivity to MPD or nicotine.

  2. Personal PM2.5 exposure and markers of oxidative stress in blood

    DEFF Research Database (Denmark)

    Sørensen, Mette; Daneshvar, Bahram; Hansen, Max;

    2003-01-01

    concentrations were found only in women (p oxidative stress and increase RBCs in peripheral blood. Personal exposure...... and the involved mechanisms remain uncertain. We measured personal PM(2.5) and carbon black exposure in 50 students four times in 1 year and analyzed blood samples for markers of protein and lipid oxidation, for red blood cell (RBC) and platelet counts, and for concentrations of hemoglobin and fibrinogen. We...... analyzed protein oxidation in terms of gamma-glutamyl semialdehyde in hemoglobin (HBGGS) and 2-aminoadipic semialdehyde in hemoglobin (HBAAS) and plasma proteins (PLAAS), and lipid peroxidation was measured as malondialdehyde (MDA) in plasma. Median exposures were 16.1 micro g/m(3) for personal PM(2...

  3. Embryo-larval exposure to atrazine reduces viability and alters oxidative stress parameters in Drosophila melanogaster.

    Science.gov (United States)

    Figueira, Fernanda Hernandes; Aguiar, Lais Mattos de; Rosa, Carlos Eduardo da

    2017-01-01

    The herbicide atrazine has been used worldwide with subsequent residual contamination of water and food, which may cause adverse effects on non-target organisms. Animal exposure to this herbicide may affect development, reproduction and energy metabolism. Here, the effects of atrazine regarding survival and redox metabolism were assessed in the fruit fly D. melanogaster exposed during embryonic and larval development. The embryos (newly fertilized eggs) were exposed to different atrazine concentrations (10μM and 100μM) in the diet until the adult fly emerged. Pupation and emergence rates, developmental time and sex ratio were determined as well as oxidative stress parameters and gene expression of the antioxidant defence system were evaluated in newly emerged male and female flies. Atrazine exposure reduced pupation and emergence rates in fruit flies without alterations to developmental time and sex ratio. Different redox imbalance patterns were observed between males and females exposed to atrazine. Atrazine caused an increase in oxidative damage, reactive oxygen species generation and antioxidant capacity and decreased thiol-containing molecules. Further, atrazine exposure altered the mRNA expression of antioxidant genes (keap1, sod, sod2, cat, irc, gss, gclm, gclc, trxt, trxr-1 and trxr-2). Reductions in fruit fly larval and pupal viability observed here are likely consequences of the oxidative stress induced by atrazine exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Direct and correlated effects of selection on flight after exposure to thermal stress in Drosophila melanogaster.

    Science.gov (United States)

    Krebs, Robert A; Thompson, Kimberly A

    2006-01-01

    To demonstrate how insects may adapt to ecologically relevant levels of heat stress, we performed artificial selection on the ability of Drosophila melanogaster to fly after an exposure to a high but non-lethal thermal stress. Both tolerance and intolerance to heat stress arose very quickly, as only a few generations of selection were necessary to cause significant separation between high and low lines for heat tolerance. Estimates of heritability based on the lines artificially selected for increased flight ability ranged from 0.024 to 0.052, while estimates of heritability based on the lines selected for the inability to fly after heat stress varied between 0.035 and 0.091. Reciprocal F1 crosses among these lines revealed strong additive effects of one or more autosomes and a weaker X-chromosome effect. This variation apparently affected flight specifically; neither survival to a more extreme stress nor knockdown by high temperature changed between lines selected for high and low heat tolerance as measured by flight ability. As the well-studied heat-shock response is associated with heat tolerance as measured by survival and knockdown, the aspects of the stress physiology that actually affect flight ability remains unknown.

  5. Cellular stress response in Eca-109 cells inhibits apoptosis during early exposure to isorhamnetin.

    Science.gov (United States)

    Shi, C; Fan, L Y; Cai, Z; Liu, Y Y; Yang, C L

    2012-01-01

    The flavonol aglycone isorhamnetin shows anti-proliferative activity in a variety of cancer cells. Previous work, from our laboratory showed that isorhamnetin inhibits the proliferation of human esophageal squamous carcinoma Eca-109 cells in vitro, but only after 72 h of exposure. This led us to propose that isorhamnetin exposure induces a cellular stress response that inhibits the antiproliferative and apoptotic effects of the compound during early exposure. To test this hypothesis, the present study examined the effects of isorhamnetin on Eca-109 cells during the first 72 h of exposure. Cell growth was assessed using the trypan blue exclusion assay, and expression of IκBα, NF-κB/p65, NF-κB/p50, phospho-Akt, Bcl-2, COX-2, Mcl-1, Bax, p53 and Id-1 were analyzed by Western blot. During the first 72 h of exposure, NF-κB/p65 and NF-κB/p50 accumulated in nuclei and expression of COX-2, Bcl-2 and Mcl-1 increased. In contrast, expression of IκBα and Bax fell initially but later increased. Expression of phospho-Akt and p53 showed no detectable change during the first 48 h. Pretreatment with the NF-κB inhibitor MG132 before exposure to isorhamnetin blocked the nuclear accumulation of p50 and p65, thereby inhibiting cell proliferation. These results show that during early exposure of Eca-109 cells to isorhamnetin, the NF-κB signaling pathway is activated and COX-2 expression increases, and this increase in expression partially inhibits isorhamnetin-induced apoptosis. Beyond 72 h of exposure, however, the apoptotic effect of isorhamnetin dominates, leading to inhibition of the NF-κB pathway and of cellular proliferation. These results will need to be taken into account when exploring the use of isorhamnetin against cancer in vivo.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  7. 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.

  8. The Effects of Mediated Exposure to Ethnic-Political Violence on Middle East Youth's Subsequent Post-Traumatic Stress Symptoms and Aggressive Behavior.

    Science.gov (United States)

    Gvirsman, Shira Dvir; Huesmann, L Rowell; Dubow, Eric F; Landau, Simha F; Shikaki, Khalil; Boxer, Paul

    2014-10-01

    This study introduces the concept of chronic (i.e., repeated and cumulative) mediated exposure to political violence and investigates its effects on aggressive behavior and post-traumatic stress (PTS) symptoms in young viewers. Embracing the risk-matrix approach, these effects are studied alongside other childhood risk factors that influence maladjustment. A longitudinal study was conducted on a sample of youth who experience the Israeli-Palestinian conflict firsthand (N = 1,207). As hypothesized, higher levels of chronic mediated exposure were longitudinally related to higher levels of PTS symptoms and aggression at peers independently of exposure to violence in other contexts. In the case of aggressive behavior, structural equation analysis (SEM) analyses suggest that, while it is likely there are causal effects in both directions, the bigger effect is probably for exposure to violence stimulating aggression than for aggression stimulating exposure to violence. Both the longitudinal effects on aggression and PTS symptoms were especially strong among youth who demonstrated initially higher levels of the same type of maladjustment. These results support the conceptualization of the relation between media violence and behaviors as "reciprocally determined" or "downward spirals" and highlight the contribution of the risk-matrix approach to the analysis of childhood maladjustment.

  9. The Effects of Mediated Exposure to Ethnic-Political Violence on Middle East Youth’s Subsequent Post-Traumatic Stress Symptoms and Aggressive Behavior

    Science.gov (United States)

    Gvirsman, Shira Dvir; Huesmann, L. Rowell; Dubow, Eric F.; Landau, Simha F.; Shikaki, Khalil; Boxer, Paul

    2015-01-01

    This study introduces the concept of chronic (i.e., repeated and cumulative) mediated exposure to political violence and investigates its effects on aggressive behavior and post-traumatic stress (PTS) symptoms in young viewers. Embracing the risk-matrix approach, these effects are studied alongside other childhood risk factors that influence maladjustment. A longitudinal study was conducted on a sample of youth who experience the Israeli-Palestinian conflict firsthand (N = 1,207). As hypothesized, higher levels of chronic mediated exposure were longitudinally related to higher levels of PTS symptoms and aggression at peers independently of exposure to violence in other contexts. In the case of aggressive behavior, structural equation analysis (SEM) analyses suggest that, while it is likely there are causal effects in both directions, the bigger effect is probably for exposure to violence stimulating aggression than for aggression stimulating exposure to violence. Both the longitudinal effects on aggression and PTS symptoms were especially strong among youth who demonstrated initially higher levels of the same type of maladjustment. These results support the conceptualization of the relation between media violence and behaviors as “reciprocally determined” or “downward spirals” and highlight the contribution of the risk-matrix approach to the analysis of childhood maladjustment. PMID:26456988

  10. 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...

  11. Posttraumatic Stress Symptoms and Nonmedical Prescription Drug Use Among College Students With Trauma Exposure.

    Science.gov (United States)

    Ham, Lindsay S; Wiersma-Mosley, Jacquelyn D; Feldner, Matthew T; Melkonian, Alexander J; Milner, Lauren A; Lewis, Sarah F

    2016-01-01

    Nonmedical prescription drug use, defined as using the drug without a prescription or in ways for which it is not prescribed, and traumatic event exposure are highly prevalent among college students. Despite evidence that posttraumatic stress symptoms could place college students at risk for nonmedical prescription drug problems, no studies have examined this relationship. This study was a preliminary examination of posttraumatic stress symptoms, lifetime nonmedical prescription drug use, hazardous use, and dependence symptoms among college students with trauma exposure. Participants were students attending a rural college in Virginia, recruited through psychology classes, flyers, LISTSERVs, and announcements at student events. All students who reported experiencing at least one traumatic event were included (N = 119); participants' mean age was 19.7 years (SD = 1.90), about half were women (n = 63, 53%), and most were Caucasian (n = 103, 87%). Nearly 60% of participants (n = 71) reported using nonmedical prescription drugs at least once during their lifetime and were more likely than those with no use to report hazardous alcohol use (p stress symptom frequency was positively associated with hazardous nonmedical prescription drug use, after controlling for gender, depressive symptoms, and hazardous alcohol use (p stress symptom frequency was higher for those with any nonmedical prescription drug dependence symptoms (p student had ever engaged in nonmedical prescription drug use. Findings suggest that consideration of the types of behaviors and problems a college student is experiencing related to nonmedical prescription drug use may be more relevant to posttraumatic stress symptom frequency than dichotomous measures of nonmedical prescription drug use alone. Further, the association between the frequency of posttraumatic stress symptoms and both hazardous nonmedical prescription drug use and dependence symptoms among college students with a trauma history deserves

  12. Trait anxiety mediates the effect of stress exposure on post-traumatic stress disorder and depression risk in cardiac surgery patients

    NARCIS (Netherlands)

    Kok, Lotte; Sep, Milou S; Veldhuijzen, Dieuwke S; Cornelisse, Sandra; Nierich, Arno P; van der Maaten, Joost; Rosseel, Peter M; Hofland, Jan; Dieleman, Jan M; Vinkers, Christiaan H; Joëls, Marian; van Dijk, Diederik; Hillegers, Manon H

    2016-01-01

    BACKGROUND: Post-traumatic stress disorder (PTSD) and depression are common after cardiac surgery. Lifetime stress exposure and personality traits may influence the development of these psychiatric conditions. METHODS: Self-reported rates of PTSD and depression and potential determinants (i.e.,

  13. Exposure to Fine Particulate Air Pollution Causes Vascular Insulin Resistance by Inducing Pulmonary Oxidative Stress.

    Science.gov (United States)

    Haberzettl, Petra; O'Toole, Timothy E; Bhatnagar, Aruni; Conklin, Daniel J

    2016-12-01

    Epidemiological evidence suggests that exposure to ambient air fine particulate matter (PM2.5) increases the risk of developing type 2 diabetes and cardiovascular disease. However, the mechanisms underlying these effects of PM2.5 remain unclear. We tested the hypothesis that PM2.5 exposure decreases vascular insulin sensitivity by inducing pulmonary oxidative stress. Mice fed control (10-13% kcal fat) and high-fat (60% kcal fat, HFD) diets, treated with 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPOL) or mice overexpressing lung-specific extracellular superoxide dismutase (ecSOD) were exposed to HEPA-filtered air or to concentrated PM2.5 (CAP) for 9 or 30 days, and changes in systemic and organ-specific insulin sensitivity and inflammation were measured. In control diet-fed mice, exposure to CAP for 30 days decreased insulin-stimulated Akt phosphorylation in lung, heart, and aorta but not in skeletal muscle, adipose tissue, and liver and did not affect adiposity or systemic glucose tolerance. In HFD-fed mice, 30-day CAP exposure suppressed insulin-stimulated endothelial nitric oxide synthase (eNOS) phosphorylation in skeletal muscle and increased adipose tissue inflammation and systemic glucose intolerance. In control diet-fed mice, a 9-day CAP exposure was sufficient to suppress insulin-stimulated Akt and eNOS phosphorylation and to decrease IκBα (inhibitor of the transcription factor NF-κB levels in the aorta. Treatment with the antioxidant TEMPOL or lung-specific overexpression of ecSOD prevented CAP-induced vascular insulin resistance and inflammation. Short-term exposure to PM2.5 induces vascular insulin resistance and inflammation triggered by a mechanism involving pulmonary oxidative stress. Suppression of vascular insulin signaling by PM2.5 may accelerate the progression to systemic insulin resistance, particularly in the context of diet-induced obesity. Citation: Haberzettl P, O'Toole TE, Bhatnagar A, Conklin DJ. 2016. Exposure to fine

  14. Mechanisms of adaptation from a multiple to a single step recovery strategy following repeated exposure to forward loss of balance in older adults.

    Directory of Open Access Journals (Sweden)

    Christopher P Carty

    Full Text Available When released from an initial, static, forward lean angle and instructed to recover with a single step, some older adults are able to meet the task requirements, whereas others either stumble or fall. The purpose of the present study was to use the concept of margin of stability (MoS to investigate balance recovery responses in the anterior-posterior direction exhibited by older single steppers, multiple steppers and those that are able to adapt from multiple to single steps following exposure to repeated forward loss of balance. One hundred and fifty-one healthy, community dwelling, older adults, aged 65-80 years, participated in the study. Participants performed four trials of the balance recovery task from each of three initial lean angles. Balance recovery responses in the anterior-posterior direction were quantified at three events; cable release (CR, toe-off (TO and foot contact (FC, for trials performed at the intermediate lean angle. MoS was computed as the anterior-posterior distance between the forward boundary of the Base of Support (BoS and the vertical projection of the velocity adjusted centre of mass position (XCoM. Approximately one-third of participants adapted from a multiple to a single step recovery strategy following repeated exposure to the task. MoS at FC for the single and multiple step trials in the adaptation group were intermediate between the exclusively single step group and the exclusively multiple step group, with the single step trials having a significant, 3.7 times higher MoS at FC than the multiple step trials. Consistent with differences between single and multiple steppers, adaptation from multiple to single steps was attributed to an increased BoS at FC, a reduced XCoM at FC and an increased rate of BoS displacement from TO to FC. Adaptations occurred within a single test session and suggest older adults that are close to the threshold of successful recovery can rapidly improve dynamic stability following

  15. REPEATED EXPOSURE OF SODIUM TELLURITE ON THE RAT LIVER AND ON THE POTENTIAL MECHANISMS OF THE METALLOID-INDUCED HEPATOTOXICITY.

    Science.gov (United States)

    Safhi, Mohammed M; Alam, Mohammad Firoz; Khuwaja, Gulrana; Islam, Farah; Hussain, Sohail; Fageeh, Mohsen Mohammed; Anwer, Tarique; Islam, Fakhrul

    2016-01-01

    Tellurium (Te) is a semiconductor and is frequently doped with copper, tin, gold or silver. It is also used to color glass and ceramics and is one of the primary ingredients in blasting caps. Little is known about Te biological activity but it is well known for toxicity to human and animals. It has inhibited the lipids profiles and oxidative stress in the brain of mice. Sodium tellurite 4.15, 8.3 and 16.6 mg/kg (1/20, 1/10 and 1/5 of LD50, respectively) was given to male Wistar rats orally in saline for a period of 15 days. On day 16, the blood was collected and the livers were dissected out for biochemical assays. The hepatotoxicity biomarkers [bilirubin, aspartate aminotransferase (AST), alanine transaminase (ALT) and alkaline phosphatase (ALP)] were elevated significantly and dose dependently in the serum of Te treated groups as compared to control group. The content of thiobarbituric reactive substances in Te treated groups was increased significantly and dose-dependently as compared to control group. Conversely, the content of glutathione and activities of antioxidant enzymes (glutathione peroxidase, glutathione reductase, glutathione-S-transferase, superoxide dismutase and catalase) were decreased significantly in Te treated groups as compared to control group. No data of inorganic Te compounds on the liver toxicity of rats are available. The aim of the present study was to evaluate the hepatotoxicity of inorganic Te compound. In conclusion, Te accelerated hepatotoxicity and oxidative stress in liver tissue of rats.

  16. Acute Onset of Vancomycin Anaphylaxis With Disseminated Intravascular Coagulation in an Orthopedic Patient Despite Prior Repeated Exposure.

    Science.gov (United States)

    Adams, Brock; Roboubi, Babak; Henshaw, Robert

    2015-12-01

    Vancomycin is a glycopeptide antibiotic that exhibits bactericidal activity against gram-positive cocci. It is commonly recommended for surgical prophylaxis in cases of suspected bacterial resistance or penicillin allergy. There are 2 main types of hypersensitivity reactions associated with vancomycin. Red man syndrome is an anaphylactoid reaction caused by direct release of histamine. The second is an anaphylactic reaction, which is an immunoglobulin E-mediated response. We present the case of a 55-year-old woman with a history of metastatic giant cell tumor of the right proximal tibia. She had undergone multiple surgeries for this and other nonorthopedic conditions. The patient received vancomycin for the majority of these procedures and extended courses of vancomycin on 2 separate occasions. In the present case, the patient was taken to the operating room for a prosthetic infection, and vancomycin was given after cultures were taken. The patient immediately developed signs consistent with anaphylaxis and disseminated intravascular coagulation. This was treated acutely with hemodynamic resuscitation, replacement of blood components, steroids, and repeated boluses of epinephrine. She recovered and was taken back to the operating room during that same admission without incident. The patient has since been treated with systemic daptomycin and a tobramycin cement spacer without further incident.

  17. Repeated sedimentation and exposure of glacial Lake Missoula sediments: A lake-level history at Garden Gulch, Montana, USA

    Science.gov (United States)

    Smith, Larry N.

    2017-01-01

    Glaciolacustrine sediments record lake transgression, regression, and subaerial modification of the silty lake-bottom of glacial Lake Missoula in the Clark Fork River valley. The sequence preserved at Garden Gulch, MT documents lake-level fluctuations at >65% of its full-pool volume. Twelve sedimentary cycles fine upwards from (1) very fine-grained sandy silt to (2) silt with climbing ripples to (3) rhythmically laminated silt and some clay. The cycles are fine-grained turbidites capped locally by thin layers of angular gravel derived from local bedrock outcrops. The gravels appear to be the toes of mass wasting lobes carried onto the exposed lakebed surface during repeated lake-level lowerings. Periglacial wedges, small rotational faults, involutions, and clastic dikes deform the tops of eleven cycles. The wedges are 10-30 cm wide, penetrate 30-70 cm deep, are spaced seven cycles. The Garden Gulch section may represent as few as seven and as many as twelve substantial fillings and partial to complete drainings of glacial Lake Missoula.

  18. Early life low-level cadmium exposure is positively associated with increased oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Kippler, Maria [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Bakhtiar Hossain, Mohammad [International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka 1212 (Bangladesh); Department of Laboratory Medicine, Section of Occupational and Environmental Medicine, Lund University, Lund (Sweden); Lindh, Christian [International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka 1212 (Bangladesh); Moore, Sophie E. [MRC Keneba, MRC Laboratories (Gambia); Kabir, Iqbal [Department of Laboratory Medicine, Section of Occupational and Environmental Medicine, Lund University, Lund (Sweden); Vahter, Marie [Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm (Sweden); Broberg, Karin, E-mail: karin.broberg_palmgren@med.lu.se [International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), Dhaka 1212 (Bangladesh)

    2012-01-15

    Environmental exposure to cadmium (Cd) is known to induce oxidative stress, a state of imbalance between the production of reactive oxygen species (ROS) and the ability to detoxify them, in adults. However, data are lacking on potential effects in early-life. We evaluated urinary concentrations of 8-oxo-7,8-dihydro-2 Prime -deoxyguanosine (8-oxodG), a recognized marker of oxidative DNA damage, in relation to Cd exposure in 96 predominantly breast-fed infants (11-17 weeks of age) in rural Bangladesh. Urinary 8-oxodG was measured using liquid chromatography tandem mass spectrometry and Cd in urine and breast milk by inductively coupled plasma mass spectrometry. Median concentration of 8-oxodG was 3.9 nmol/L, urinary Cd 0.30 {mu}g/L, and breast-milk Cd 0.13 {mu}g/L. In linear regression analyses, urinary 8-oxodG was positively associated with Cd in both urine (p=0.00067) and breast milk (p=0.0021), and negatively associated with body weight (kg; p=0.0041). Adjustment for age, body weight, socio-economic status, urinary arsenic, as well as magnesium, calcium, and copper in breast milk did not change the association between Cd exposure and urinary 8-oxodG. These findings suggest that early-life low-level exposure to Cd via breast milk induces oxidative stress. Further studies are warranted to elucidate whether this oxidative stress is associated with impaired child health and development.

  19. Transcriptional response of stress-regulated genes to industrial effluent exposure in the cockle Cerastoderma glaucum.

    Science.gov (United States)

    Karray, Sahar; Tastard, Emmanuelle; Moreau, Brigitte; Delahaut, Laurence; Geffard, Alain; Guillon, Emmanuel; Denis, Françoise; Hamza-Chaffai, Amel; Chénais, Benoît; Marchand, Justine

    2015-11-01

    This study assessed the responses of molecular biomarkers and heavy metal levels in Cerastoderma glaucum exposed for 1 week to two industrial effluents (1%) discharged into the Tunisian coastal area, F1 and F2, produced by different units of production of a phosphate treatment plant. A significant uptake of metals (Cd, Cu, Zn, and Ni) was observed in exposed cockles compared to controls, with an uptake higher for F1 than for F2. A decrease in LT50 (stress on stress test) was also observed after an exposure to the effluent F1. Treatments resulted in different patterns of messenger RNA (mRNA) expression of the different genes tested in this report. Gene transcription monitoring performed on seven genes potentially involved in the tolerance to metal exposure showed that for both exposures, mechanisms are rapidly and synchronically settled down to prevent damage to cellular components, by (1) handling and exporting out metal ions through the up-regulation of ATP-binding cassette xenobiotic transporter (ABCB1) and metallothionein (MT), (2) increasing the mRNA expression of antioxidant enzymes (catalase (CAT), superoxide dismutases, CuZnSOD and MnSOD), (3) protecting and/or repairing proteins through the expression of heat shock protein 70 (HSP70) mRNAs, and (4) increasing ATP production (through the up-regulation of cytochrome c oxidase 1 (CO1)) to provide energy for cells to tolerate stress exposure. The tools developed may be useful both for future control strategies and for the use of the cockle C. glaucum as a sentinel species.

  20. Long-term effects of prenatal atrazine exposure on physiology, body composition, and stress reactivity in rats

    Science.gov (United States)

    Low birth weight in humans is associated with increased risk of coronary heart disease, hypertension, and diabetes in adulthood. Experimental studies have also reported that undernutrition, stress or exposure to glucocorticoids during pregnancy is associated with hypertension, gl...

  1. Long-term effects of prenatal atrazine exposure on physiology, body composition, and stress reactivity in rats

    Science.gov (United States)

    Low birth weight in humans is associated with increased risk of coronary heart disease, hypertension, and diabetes in adulthood. Experimental studies have also reported that undernutrition, stress or exposure to glucocorticoids during pregnancy is associated with hypertension, gl...

  2. Repeatability of baseline corticosterone and short-term corticosterone stress responses, and their correlation with testosterone and body condition in a terrestrial breeding anuran (Platymantis vitiana).

    Science.gov (United States)

    Narayan, Edward J; Cockrem, John F; Hero, Jean-Marc

    2013-06-01

    Repeatability of physiological response variables, such as the stress hormone corticosterone, across numerous sampling occasions is an important assumption for their use as predictors of behaviour, reproduction and fitness in animals. Very few studies have actually tested this assumption in free-living animals under uncontrolled natural conditions. Non-invasive urine sampling and standard capture handling protocol have enabled the rapid quantification of baseline corticosterone and short-term corticosterone stress responses in anuran amphibians. In this study, established non-invasive methods were used to monitor physiological stress and urinary testosterone levels in male individuals of the terrestrial breeding Fijian ground frog (Platymantis vitiana). Adult male frogs (n = 20) were sampled at nighttime on three repeated occasions at intervals of 14 days during their annual breeding season on Viwa Island, Fiji. All frogs expressed urinary corticosterone metabolite responses to the capture and handling stressor, with some frogs showing consistently higher urinary corticosterone responses than others. Ranks of corticosterone values at 0, 4 and 8 h, and the corrected rank were highly significant (r = 0.75-0.99) between the three repeated sampling occasions. Statistical repeatabilities were high for baseline corticosterone (r = 0.973) and for corticosterone values at 2 h (r = 0.862), 4 h (r = 0.861), 6 h (r = 0.820) and 8 h (r = 0.926), and also for the total (inclusive of baseline corticosterone values) and the corrected integrated responses (index of the acute response) [r = 0.867 and r = 0.870]. Urinary testosterone levels also showed high statistical repeatability (r = 0.78). Furthermore, variation in baseline and short-term corticosterone stress responses was greater between individuals than within individuals. Baseline urinary corticosterone was significantly negatively correlated with the corrected integrated corticosterone response (r = -0.3, p breeding period

  3. Controlled human wood smoke exposure: oxidative stress, inflammation and microvascular function

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    Forchhammer Lykke

    2012-03-01

    Full Text Available Abstract Background Exposure to wood smoke is associated with respiratory symptoms, whereas knowledge on systemic effects is limited. We investigated effects on systemic inflammation, oxidative stress and microvascular function (MVF after controlled wood smoke exposure. Methods In a randomised, double-blinded, cross-over study 20 non-smoking atopic subjects were exposed at rest to 14, 220, or 354 μg/m3 of particles from a well-burning modern wood stove for 3 h in a climate controlled chamber with 2 week intervals. We investigated the level of oxidatively damaged DNA, inflammatory markers and adhesion molecules before and 0, 6 and 20 h after exposure. Six h after exposure we measured MVF non-invasively by digital peripheral artery tonometry following arm ischemia. Results The MVF score was unaltered after inhalation of clean air (1.58 ± 0.07; mean ± SEM, low (1.51 ± 0.07 or high (1.61 ± 0.09 concentrations of wood smoke particles in atopic subjects, whereas unexposed non-atopic subjects had higher score (1.91 ± 0.09. The level of oxidatively damaged DNA, mRNA of ITGAL, CCL2, TNF, IL6, IL8, HMOX1, and OGG1 and surface marker molecules ICAM1, ITGAL and L-selectin in peripheral blood mononuclear cells were not affected by inhalation of wood smoke particles. Conclusions Exposure to wood smoke had no effect on markers of oxidative stress, DNA damage, cell adhesion, cytokines or MVF in atopic subjects.

  4. Exposure to political conflict and violence and posttraumatic stress in Middle East youth: protective factors.

    Science.gov (United States)

    Dubow, Eric F; Huesmann, L Rowell; Boxer, Paul; Landau, Simha; Dvir, Shira; Shikaki, Khalil; Ginges, Jeremy

    2012-01-01

    We examine the role of family- and individual-level protective factors in the relation between exposure to ethnic-political conflict and violence and posttraumatic stress among Israeli and Palestinian youth. Specifically, we examine whether parental mental health (lack of depression), positive parenting, children's self-esteem, and academic achievement moderate the relation between exposure to ethnic-political conflict/violence and subsequent posttraumatic stress (PTS) symptoms. We collected three waves of data from 901 Israeli and 600 Palestinian youths (three age cohorts: 8, 11, and 14 years old; approximately half of each gender) and their parents at 1-year intervals. Greater cumulative exposure to ethnic-political conflict/violence across the first 2 waves of the study predicted higher subsequent PTS symptoms even when we controlled for the child's initial level of PTS symptoms. This relation was significantly moderated by a youth's self-esteem and by the positive parenting received by the youth. In particular, the longitudinal relation between exposure to violence and subsequent PTS symptoms was significant for low self-esteem youth and for youth receiving little positive parenting but was non-significant for children with high levels of these protective resources. Our findings show that youth most vulnerable to PTS symptoms as a result of exposure to ethnic-political violence are those with lower levels of self-esteem and who experience low levels of positive parenting. Interventions for war-exposed youth should test whether boosting self-esteem and positive parenting might reduce subsequent levels of PTS symptoms.

  5. Oxidative stress and air pollution exposure during pregnancy: A molecular assessment.

    Science.gov (United States)

    Nagiah, S; Phulukdaree, A; Naidoo, D; Ramcharan, K; Naidoo, R N; Moodley, D; Chuturgoon, A

    2015-08-01

    Chronic air pollution exposure during pregnancy can cause oxidative stress leading to adverse birth outcomes. The aim of this study was to assess and compare oxidative stress response in peripheral lymphocytes isolated from pregnant women from a highly industrialized locale (south Durban (SD); n = 50) and a control with lower air pollutant levels (north Durban (ND); n = 50). Oxidative stress response was measured by quantifying malondialdehyde (MDA) levels and a SuperArray gene panel. Mitochondrial function (adenosine triphosphate (ATP) levels and mitochondrial depolarization), DNA integrity (comet assay and mitochondrial DNA (mtDNA) viability) and DNA repair (OGG1) were assessed. Antioxidant response was assessed by quantification of glutathione (GSH) and SOD2, nuclear factor erythroid 2-related factor 2 (Nrf2) and uncoupling protein 2 (UCP2) protein and messenger RNA (mRNA) expression. Levels of MDA (p = 0.9), mitochondrial depolarization (p = 0.88), ATP (1.89-fold), SOD2 (1.23-fold) and UCP2 (1.58-fold) gene expression were elevated in the SD group with significantly higher UCP2 protein levels (p = 0.05) and longer comet tail length (p = 0.0004). The expression of Nrf2 protein (p = 0.03) and mRNA levels (-1.37-fold), GSH concentration (p stress-related genes evaluated, 26 were differentially regulated. Pregnant women exposed to higher air pollutant levels showed increased markers for oxidative stress and compromised DNA integrity and repair. © The Author(s) 2014.

  6. Exposure to forced swim stress alters local circuit activity and plasticity in the dentate gyrus of the hippocampus.

    Science.gov (United States)

    Yarom, Orli; Maroun, Mouna; Richter-Levin, Gal

    2008-01-01

    Studies have shown that, depending on its severity and context, stress can affect neural plasticity. Most related studies focused on synaptic plasticity and long-term potentiation (LTP) of principle cells. However, evidence suggests that following high-frequency stimulation, which induces LTP in principal cells, modifications also take place at the level of complex interactions with interneurons within the dentate gyrus, that is, at the local circuit level. So far, the possible effects of stress on local circuit activity and plasticity were not studied. Therefore, we set out to examine the possible alterations in local circuit activity and plasticity following exposure to stress. Local circuit activity and plasticity were measured by using frequency dependant inhibition (FDI) and commissural modulation protocols following exposure to a 15 minute-forced swim trial. Exposure to stress did not alter FDI. The application of theta-burst stimulation (TBS) reduced FDI in both control and stressed rats, but this type of plasticity was greater in stressed rats. Commissural-induced inhibition was significantly higher in stressed rats both before and after applying theta-burst stimulation. These findings indicate that the exposure to acute stress affects aspects of local circuit activity and plasticity in the dentate gyrus. It is possible that these alterations underlie some of the behavioral consequences of the stress experience.

  7. Exposure to Forced Swim Stress Alters Local Circuit Activity and Plasticity in the Dentate Gyrus of the Hippocampus

    Directory of Open Access Journals (Sweden)

    Orli Yarom

    2008-01-01

    Full Text Available Studies have shown that, depending on its severity and context, stress can affect neural plasticity. Most related studies focused on synaptic plasticity and long-term potentiation (LTP of principle cells. However, evidence suggests that following high-frequency stimulation, which induces LTP in principal cells, modifications also take place at the level of complex interactions with interneurons within the dentate gyrus, that is, at the local circuit level. So far, the possible effects of stress on local circuit activity and plasticity were not studied. Therefore, we set out to examine the possible alterations in local circuit activity and plasticity following exposure to stress. Local circuit activity and plasticity were measured by using frequency dependant inhibition (FDI and commissural modulation protocols following exposure to a 15 minute-forced swim trial. Exposure to stress did not alter FDI. The application of theta-burst stimulation (TBS reduced FDI in both control and stressed rats, but this type of plasticity was greater in stressed rats. Commissural-induced inhibition was significantly higher in stressed rats both before and after applying theta-burst stimulation. These findings indicate that the exposure to acute stress affects aspects of local circuit activity and plasticity in the dentate gyrus. It is possible that these alterations underlie some of the behavioral consequences of the stress experience.

  8. Patient-specific finite element analysis of chronic contact stress exposure after intraarticular fracture of the tibial plafond.

    Science.gov (United States)

    Li, Wendy; Anderson, Donald D; Goldsworthy, Jane K; Marsh, J Lawrence; Brown, Thomas D

    2008-08-01

    The role of altered contact mechanics in the pathogenesis of posttraumatic osteoarthritis (PTOA) following intraarticular fracture remains poorly understood. One proposed etiology is that residual incongruities lead to altered joint contact stresses that, over time, predispose to PTOA. Prevailing joint contact stresses following surgical fracture reduction were quantified in this study using patient-specific contact finite element (FE) analysis. FE models were created for 11 ankle pairs from tibial plafond fracture patients. Both (reduced) fractured ankles and their intact contralaterals were modeled. A sequence of 13 loading instances was used to simulate the stance phase of gait. Contact stresses were summed across loadings in the simulation, weighted by resident time in the gait cycle. This chronic exposure measure, a metric of degeneration propensity, was then compared between intact and fractured ankle pairs. Intact ankles had lower peak contact stress exposures that were more uniform and centrally located. The series-average peak contact stress elevation for fractured ankles was 38% (p = 0.0015; peak elevation was 82%). Fractured ankles had less area with low contact stress exposure than intact ankles and a greater area with high exposure. Chronic contact stress overexposures (stresses exceeding a damage threshold) ranged from near zero to a high of 18 times the matched intact value. The patient-specific FE models represent substantial progress toward elucidating the relationship between altered contact stresses and the outcome of patients treated for intraarticular fractures.

  9. Repeated inhalation exposure to octamethylcyclotetrasiloxane produces hepatomegaly, transient hepatic hyperplasia, and sustained hypertrophy in female Fischer 344 rats in a manner similar to phenobarbital.

    Science.gov (United States)

    McKim, J M; Kolesar, G B; Jean, P A; Meeker, L S; Wilga, P C; Schoonhoven, R; Swenberg, J A; Goodman, J I; Gallavan, R H; Meeks, R G

    2001-04-15

    Octamethylcyclotetrasiloxane (D4) has been described as a phenobarbital-like inducer of hepatic enzymes. Phenobarbital (PB) and phenobarbital-like chemicals induce transient hepatic and thyroid hyperplasia and sustained hypertrophy in rats and mice. The extent to which these processes are involved with D4-induced hepatomegaly is not known. The present study has evaluated the effects of repeated inhalation exposure to D4 vapors on hepatic and thyroid cell proliferation and hypertrophy with respect to time and exposure concentration. Female Fischer 344 rats were exposed via whole body inhalation to 0 ppm D4, 700 ppm D4 vapors (6 h/day; 5 days/week), or 0.05% PB in drinking water over a 4-week period. Incorporation of 5'-bromo-2-deoxyuridine (BrdU) and the abundance of proliferating cell nuclear antigen were used as indicators of cell proliferation. Designated animals from each treatment group were euthanized on study days 6, 13, and 27. The effect of D4 exposure concentration on hepatic cell proliferation was evaluated at 0, 7, 30, 70, 150, 300, or 700 ppm. Liver-to-body weight ratios in animals exposed to 700 ppm D4 were increased 18, 20, and 22% over controls while PB-treated animals showed increases of 33, 27, and 27% over controls on days 6, 13, and 27 respectively. Hepatic incorporation of BrdU following exposure to D4 was highest on day 6 (labeling index = 15-22%) and was at or below control values by day 27. This pattern of transient hyperplasia was observed in all hepatic lobes examined and was similar to the pattern observed following treatment with PB.

  10. 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

  11. Posttraumatic stress disorder and exposure to trauma reminders after a terrorist attack.

    Science.gov (United States)

    Glad, Kristin A; Jensen, Tine K; Hafstad, Gertrud S; Dyb, Grete

    2016-01-01

    The aims of this study were twofold: (a) to systematically describe the type and frequency of trauma reminders reported after a terrorist attack and (b) to examine whether posttraumatic stress disorder (PTSD) is associated with frequency of exposure to trauma reminders. A total of 285 survivors (M age = 22.2, SD = 4.3, 53% males) of the 2011 massacre on Utøya Island, Norway, were interviewed face to face 14-15 months after the terror. Participants were asked how often they had experienced a range of different trauma reminders in the past month and which was most distressing. Current posttraumatic stress reactions were measured using the University of California at Los Angeles PTSD Reaction Index. In all, 33.3% of the survivors reported having experienced 1 or more trauma reminders often/very often in the past month. Auditory reminders were most frequently encountered and were reported to be the most distressing, especially sudden and sharp noises. Meeting the diagnostic criteria for PTSD was significantly associated with frequency of exposure to trauma reminders. The findings suggest that trauma reminders are common among survivors of a terrorist attack almost 1.5 years after the trauma and that PTSD is strongly related to the frequency of exposure to reminders. It is important that clinicians are aware of the significant role trauma reminders may play in maintaining PTSD and help trauma survivors recognize and manage reminders.

  12. 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

  13. Greater sensitivity to novelty in rats is associated with increased motor impulsivity following repeated exposure to a stimulating environment: implications for the etiology of impulse control deficits.

    Science.gov (United States)

    Ferland, Jacqueline-Marie N; Zeeb, Fiona D; Yu, Katrina; Kaur, Sukhbir; Taves, Matthew D; Winstanley, Catharine A

    2014-12-01

    Heightened motor impulsivity and increased novelty-seeking commonly co-occur in psychiatric disorders, including drug addiction. However, the relationship between these two phenomena remains unclear. One-time tests of novelty sensitivity commonly used in preclinical experiments, such as the open-field or novel-object test, fail to capture the fact that novelty-seekers repeatedly experience novel, stimulating situations. The present study therefore investigated whether repeated exposure to a novel, stimulating environment (SE) altered impulsive action. Male Long-Evans rats were trained to perform the five-choice serial reaction time task (5CSRTT) which measures motor impulsivity in the form of premature responding as well as attention and motivation. Animals were then exposed to a novel SE (1 h/day for 16 days) immediately prior to the 5CSRTT. Significant increases in premature responding were observed in a subgroup of reactive animals termed high responders (HR-SE). These rats were not more impulsive at baseline, and levels of impulsivity normalised once exposure to the SE was discontinued. No other aspect of 5CSRTT performance was affected by the SE challenge. We also determined that HR-SE rats were hyperactive in a novel environment. Biochemical analyses revealed changes in gene and protein expression within the dorsal hippocampus of HR-SE rats, including decreases in mRNA encoding the dopamine D1 receptor and brain-derived neurotrophic factor. These results indicate a novel mechanism by which impulsivity and novelty-reactivity interact that may enhance addiction vulnerability synergistically. Furthermore, studying such context-induced impulsivity may provide insight into the process by which environmental load precipitates psychiatric symptoms in impulse control disorders.

  14. Effects of repeated low-dose exposure of the nerve agent VX on monoamine levels in different brain structures in mice.

    Science.gov (United States)

    Graziani, S; Christin, D; Daulon, S; Breton, P; Perrier, N; Taysse, L

    2014-05-01

    In a previous report, alterations of the serotonin metabolism were previously reported in mice intoxicated with repeated low doses of soman. In order to better understand the effects induced by repeated low-dose exposure to organophosphorus compounds on physiological and behavioural functions, the levels of endogenous monoamines (serotonin and dopamine) in different brain areas in mice intoxicated with sublethal dose of (O-ethyl-S-[2(di-isopropylamino) ethyl] methyl phosphonothioate) (VX) were analysed by HPLC method with electrochemical detection. Animals were injected once a day for three consecutive days with 0.10 LD50 of VX (5 μg/kg, i.p). Neither severe signs of cholinergic toxicity nor pathological changes in brain tissue of exposed animals were observed. Cholinesterase (ChE) activity was only inhibited in plasma (a maximum of 30% inhibition 24 h after the last injection of VX), but remained unchanged in the brain. Serotonin and dopamine (DA) metabolism appeared significantly modified. During the entire period of investigation, at least one of the three parameters investigated (i.e. DA and DOPAC levels and DOPAC/DA ratio) was modified. During the toxic challenge, an increase of the serotonin metabolism was noted in hippocampus (HPC), hypothalamus/thalamus, pons medulla and cerebellum (CER). This increase was maintained 4 weeks after exposure in HPC, pons medulla and CER whereas a decrease in cortex 3 weeks after the toxic challenge was observed. The lack of correlation between brain ChE activity and neurochemical outcomes points out to independent mechanisms. The involvement in possibly long-lasting behavioural disorders is discussed.

  15. Anxiolytic Effects of Herbal Ethanol Extract from Gynostemma pentaphyllum in Mice after Exposure to Chronic Stress

    Directory of Open Access Journals (Sweden)

    Myung Koo Lee

    2013-04-01

    Full Text Available In this study, the effects of herbal ethanol extracts of Gynostemma pentaphyllum (GP-EX, on chronic electric footshock (EF stress-induced anxiety disorders were investigated in mice, which were orally treated with GP-EX (30 mg/kg and 50 mg/kg once a day for 14 days, followed by exposure to EF stress (2 mA, with an interval and duration of 10 s for 3 min. After the final exposure to EF stress, the elevated plus-maze and marble burying tests were performed, and the levels of dopamine and serotonin in the brain, the serum levels of corticosterone, and the expression of c-Fos in the paraventricular nuclei (PVN were determined. Treatment with GP-EX (30 mg/kg and 50 mg/kg significantly recovered the number of entries into open arms and time spent on open arms, which was reduced by chronic EF stress. GP-EX (30 mg/kg and 50 mg/kg also reduced the number of marbles buried, which was increased by chronic EF stress. In addition, electric EF stress significantly decreased the levels of dopamine and serotonin in the brain, which was recovered by treatment with GP-EX (30 mg/kg and 50 mg/kg. The serum levels of corticosterone, which were markedly increased by chronic EF stress, were reduced by treatment with GP-EX (30 mg/kg and 50 mg/kg. Chronic EF stress-induced increases in c-Fos expression were also markedly reduced by GP-EX (30 mg/kg and 50 mg/kg in the PVN. These results suggest that GP-EX shows anxiolytic functions, determined by the elevated plus-maze and marble burying tests, which are mediated by modulating the activity of dopamine and serotonin neurons as well as the expression of c-Fos in the brain, and the serum levels of corticosterone. Clinical trials of herbal GP-EX and its bioactive components need further investigation.

  16. Anxiolytic effects of herbal ethanol extract from Gynostemma pentaphyllum in mice after exposure to chronic stress.

    Science.gov (United States)

    Choi, Hyun Sook; Zhao, Ting Ting; Shin, Keon Sung; Kim, Seung Hwan; Hwang, Bang Yeon; Lee, Chong Kil; Lee, Myung Koo

    2013-04-12

    In this study, the effects of herbal ethanol extracts of Gynostemma pentaphyllum (GP-EX), on chronic electric footshock (EF) stress-induced anxiety disorders were investigated in mice, which were orally treated with GP-EX (30 mg/kg and 50 mg/kg) once a day for 14 days, followed by exposure to EF stress (2 mA, with an interval and duration of 10 s for 3 min). After the final exposure to EF stress, the elevated plus-maze and marble burying tests were performed, and the levels of dopamine and serotonin in the brain, the serum levels of corticosterone, and the expression of c-Fos in the paraventricular nuclei (PVN) were determined. Treatment with GP-EX (30 mg/kg and 50 mg/kg) significantly recovered the number of entries into open arms and time spent on open arms, which was reduced by chronic EF stress. GP-EX (30 mg/kg and 50 mg/kg) also reduced the number of marbles buried, which was increased by chronic EF stress. In addition, electric EF stress significantly decreased the levels of dopamine and serotonin in the brain, which was recovered by treatment with GP-EX (30 mg/kg and 50 mg/kg). The serum levels of corticosterone, which were markedly increased by chronic EF stress, were reduced by treatment with GP-EX (30 mg/kg and 50 mg/kg). Chronic EF stress-induced increases in c-Fos expression were also markedly reduced by GP-EX (30 mg/kg and 50 mg/kg) in the PVN. These results suggest that GP-EX shows anxiolytic functions, determined by the elevated plus-maze and marble burying tests, which are mediated by modulating the activity of dopamine and serotonin neurons as well as the expression of c-Fos in the brain, and the serum levels of corticosterone. Clinical trials of herbal GP-EX and its bioactive components need further investigation.

  17. Oxidative stress and DNA damage responses to phenanthrene exposure in the estuarine guppy Poecilia vivipara.

    Science.gov (United States)

    Machado, Anderson Abel de Souza; Hoff, Mariana Leivas Müller; Klein, Roberta Daniele; Cordeiro, Gilson Junior; Lencina Avila, Jannine Marquez; Costa, Patrícia Gomes; Bianchini, Adalto

    2014-07-01

    Despite ubiquitous phenanthrene contamination in aquatic coastal areas, little is known regarding its potential effects on estuarine fishes. The present work evaluated the response of a large suite of oxidative stress- and DNA damage-related biomarkers to phenanthrene exposure (10, 20 and 200 μg L(-1), 96 h) using DMSO as the solvent in estuarine guppy Poecilia vivipara (salinity 24 psu). Phenanthrene affected oxidative stress-related parameters, and decreased antioxidant defenses and reactive oxygen species in the gills and muscle overall. Lipid peroxidation occurred in muscle at 200 μg L(-1) phenanthrene. Genotoxicity was increased at 20 μg L(-1), while 200 μg L(-1) caused a relative decrease in erythrocyte release into the bloodstream. These findings indicated that phenanthrene is genotoxic and can induce oxidative stress, depending on tissue and phenanthrene concentration analyzed. Thus, some of the biomarkers analyzed in the present study are sufficiently sensitive to monitor the exposure of the guppy P. vivipara to phenanthrene in salt water. However, further studies are required for a better interpretation of the dose-response patterns observed.

  18. Thermoregulatory responses to environmental toxicants: the interaction of thermal stress and toxicant exposure.

    Science.gov (United States)

    Leon, Lisa R

    2008-11-15

    Thermal stress can have a profound impact on the physiological responses that are elicited following environmental toxicant exposure. The efficacy by which toxicants enter the body is directly influenced by thermoregulatory effector responses that are evoked in response to high ambient temperatures. In mammals, the thermoregulatory response to heat stress consists of an increase in skin blood flow and moistening of the skin surface to dissipate core heat to the environment. These physiological responses may exacerbate chemical toxicity due to increased permeability of the skin, which facilitates the cutaneous absorption of many environmental toxicants. The core temperature responses that are elicited in response to high ambient temperatures, toxicant exposure or both can also have a profound impact on the ability of an organism to survive the insult. In small rodents, the thermoregulatory response to thermal stress and many environmental toxicants (such as organophosphate compounds) is often biphasic in nature, consisting initially of a regulated reduction in core temperature (i.e., hypothermia) followed by fever. Hypothermia is an important thermoregulatory survival strategy that is used by small rodents to diminish the effect of severe environmental insults on tissue homeostasis. The protective effect of hypothermia is realized by its effects on chemical toxicity as molecular and cellular processes, such as lipid peroxidation and the formation of reactive oxygen species, are minimized at reduced core temperatures. The beneficial effects of fever are unknown under these conditions. Perspective is provided on the applicability of data obtained in rodent models to the human condition.

  19. 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,

  20. Allopurinol Reduces Oxidative Stress in the Ovine Fetal Cardiovascular System After Repeated Episodes of Ischemia-Reperfusion

    NARCIS (Netherlands)

    Derks, Jan B.; Oudijk, Martijn A.; Torrance, Helen L.; Rademaker, Carin M. A.; Benders, Manon J.; Rosen, Karl G.; Cindrova-Davies, Tereza; Thakor, Avnesh S.; Visser, Gerard H. A.; Burton, Graham J.; van Bel, Frank; Giussani, Dino A.

    2010-01-01

    In complicated lab