Phan, Jenny M; Schneider, Ekaterina; Peres, Jeremy; Miocevic, Olga; Meyer, Vanessa; Shirtcliff, Elizabeth A
Laboratory stress tasks such as the Trier Social Stress Test (TSST) have provided a key piece to the puzzle for how psychosocial stress impacts the hypothalamic-pituitary-adrenal axis, other stress-responsive biomarkers, and ultimately wellbeing. These tasks are thought to work through biopsychosocial processes, specifically social evaluative threat and the uncontrollability heighten situational demands. The present study integrated an experimental modification to the design of the TSST to probe whether additional social evaluative threat, via negative verbal feedback about speech performance, can further alter stress reactivity in 63 men and women. This TSST study confirmed previous findings related to stress reactivity and stress recovery but extended this literature in several ways. First, we showed that additional social evaluative threat components, mid-task following the speech portion of the TSST, were still capable of enhancing the psychosocial stressor. Second, we considered stress-reactive hormones beyond cortisol to include dehydroepiandrosterone (DHEA) and testosterone, and found these hormones were also stress-responsive, and their release was coupled with one another. Third, we explored whether gain- and loss-framing incentive instructions, meant to influence performance motivation by enhancing the personal relevance of task performance, impacted hormonal reactivity. Results showed that each hormone was stress reactive and further had different responses to the modified TSST compared to the original TSST. Beyond the utility of showing how the TSST can be modified with heightened social evaluative threat and incentive-framing instructions, this study informs about how these three stress-responsive hormones have differential responses to the demands of a challenge and a stressor. Copyright © 2017 Elsevier Inc. All rights reserved.
Full Text Available BACKGROUND: Bisphenol A (BPA, used in the manufacture of plastics, is ubiquitously distributed in the aquatic environment. However, the effect of maternal transfer of these xenobiotics on embryonic development and growth is poorly understood in fish. We tested the hypothesis that BPA in eggs, mimicking maternal transfer, impact development, growth and stress performance in juveniles of rainbow trout (Oncorhynchus mykiss. METHODOLOGY/PRINCIPAL FINDINGS: Trout oocytes were exposed to 0, 30 and 100 microg.mL(-1 BPA for 3 h in ovarian fluid, followed by fertilization. The embryos were maintained in clean water and sampled temporally over 156-days post-fertilization (dpf, and juveniles were sampled at 400-dpf. The egg BPA levels declined steadily after exposure and were undetectable after 21- dpf. Oocyte exposure to BPA led to a delay in hatching and yolk absorption and a consistently lower body mass over 152-dpf. The growth impairment, especially in the high BPA group, correlated with higher growth hormone (GH content and lower GH receptors gene expression. Also, mRNA abundances of insulin-like growth factors (IGF-1 and IGF-2 and their receptors were suppressed in the BPA treated groups. The juvenile fish grown from the BPA-enriched eggs had lower body mass and showed perturbations in plasma cortisol and glucose response to an acute stressor. CONCLUSION: BPA accumulation in eggs, prior to fertilization, leads to hatching delays, growth suppression and altered stress response in juvenile trout. The somatotropic axis appears to be a key target for BPA impact during early embryogenesis, leading to long term growth and stress performance defects in fish.
Maranon-Jimenez, Sara; Castro, Jorge; Querejeta, José Ignacio; Fernandez-Ondono, Emilia; Allen, Craig D.
Extensive research has focused on comparing the impacts of post-fire salvage logging versus those of less aggressive management practices on forest regeneration. However, few studies have addressed the effects of different burnt-wood management options on seedling/sapling performance, or the ecophysiological mechanisms underlying differences among treatments. In this study, we experimentally assess the effects of post-fire management of the burnt wood on the growth and performance of naturally regenerating pine seedlings (Pinus pinaster). Three post-fire management treatments varying in degree of intervention were implemented seven months after a high-severity wildfire burned Mediterranean pine forests in the Sierra Nevada, southeast Spain: (a) “No Intervention” (NI, all burnt trees left standing); (b) “Partial Cut plus Lopping” (PCL, felling most of the burnt trees, cutting off branches, and leaving all the biomass on site without mastication); and (c) “Salvage Logging” (SL, felling the burnt trees, piling up the logs and masticating the fine woody debris). Three years after the fire, the growth, foliar nutrient concentrations, and leaf carbon, nitrogen and oxygen isotopic composition (δ13C, δ18O and δ15N) of naturally regenerating seedlings were measured in all the treatments. Pine seedlings showed greatest vigor and size in the PCL treatment, whereas growth was poorest in SL. The nutrient concentrations were similar among treatments, although greater growth in the two treatments with residual wood present indicated higher plant uptake. Seedlings in the SL treatment showed high leaf δ13C and δ18O values indicating severe water stress, in contrast to significantly alleviated water stress indications in the PCL treatment. Seedling growth and physiological performance in NI was intermediate between that of PCL and SL. After six growing seasons, P. pinaster saplings in PCL showed greater growth and cone production than SL saplings. In summary
Summary: The study investigated the potential alteration in the level of insulin and adiponectin, as well as the expression of insulin receptors (INSR) and glucose transporter 4 GLUT-4 in chronic restraint stress rats. Sprague-Dawley rats were randomly divided into two groups: the control group and stress group in which the ...
Moreno-Villanueva, Maria; von Scheven, Gudrun; Feiveson, Alan; Bürkle, Alexander; Wu, Honglu; Goel, Namni
Sleep deprivation is associated with impaired immune responses, cancer, and morbidity and mortality, and can degrade cognitive performance, although individual differences exist in such responses. Sleep deprivation induces DNA strand breaks and DNA base oxidation in animals, and psychological stress is associated with increased DNA damage in humans. It remains unknown whether sleep deprivation or psychological stress in humans affects DNA damage response from environmental stressors, and whether these responses predict cognitive performance during sleep deprivation. Sixteen healthy adults (ages 29-52;mean age±SD, 36.4±7.1 years;7 women) participated in a 5-day experiment involving two 8 hour time-in-bed [TIB] baseline nights, followed by 39 hours total sleep deprivation (TSD), and two 8-10 hour TIB recovery nights. A modified Trier Social Stress Test was conducted on the day after TSD. Psychomotor Vigilance Tests measured behavioral attention. DNA damage was assessed in blood cells collected at 5 time points, and blood cells were irradiated ex-vivo. TSD, alone or in combination with psychological stress, did not induce significant increases in DNA damage. By contrast, radiation-induced DNA damage decreased significantly in response to TSD, but increased back to baseline when combined with psychological stress. Cognitively-vulnerable individuals had more radiation-induced DNA strand breaks before TSD, indicating their greater sensitivity to DNA damage from environmental stressors. Our results provide novel insights into the molecular consequences of sleep deprivation, psychological stress, and performance vulnerability. They are important for situations involving sleep loss, radiation exposure and cognitive deficits, including cancer therapy, environmental toxicology, and space medicine.
Karabeg, Margherita M.; Grauthoff, Sandra; Kollert, Sina Y.; Weidner, Magdalena; Heiming, Rebecca S.; Jansen, Friederike; Popp, Sandy; Kaiser, Sylvia; Lesch, Klaus-Peter; Sachser, Norbert
The purpose of this study was to evaluate whether spatial hippocampus-dependent learning is affected by the serotonergic system and stress. Therefore, 5-HTT knockout (-/-), heterozygous (+/-) and wildtype (+/+) mice were subjected to the Barnes maze (BM) and the Morris water maze (WM), the latter being discussed as more aversive. Additionally, immediate early gene (IEG) expression, hippocampal adult neurogenesis (aN), and blood plasma corticosterone were analyzed. While the performance of 5-HTT-/- mice in the BM was undistinguishable from both other genotypes, they performed worse in the WM. However, in the course of the repeated WM trials 5-HTT-/- mice advanced to wildtype level. The experience of a single trial of either the WM or the BM resulted in increased plasma corticosterone levels in all genotypes. After several trials 5-HTT-/- mice exhibited higher corticosterone concentrations compared with both other genotypes in both tests. Corticosterone levels were highest in 5-HTT-/- mice tested in the WM indicating greater aversiveness of the WM and a greater stress sensitivity of 5-HTT deficient mice. Quantitative immunohistochemistry in the hippocampus revealed increased cell counts positive for the IEG products cFos and Arc as well as for proliferation marker Ki67 and immature neuron marker NeuroD in 5-HTT-/- mice compared to 5-HTT+/+ mice, irrespective of the test. Most differences were found in the suprapyramidal blade of the dentate gyrus of the septal hippocampus. Ki67-immunohistochemistry revealed a genotype x environment interaction with 5-HTT genotype differences in naïve controls and WM experience exclusively yielding more Ki67-positive cells in 5-HTT+/+ mice. Moreover, in 5-HTT-/- mice we demonstrate that learning performance correlates with the extent of aN. Overall, higher baseline IEG expression and increased an in the hippocampus of 5-HTT-/- mice together with increased stress sensitivity may constitute the neurobiological correlate of raised
Cavanagh, James F; Frank, Michael J; Allen, John J B
To examine how stress affects cognitive functioning, individual differences in trait vulnerability (punishment sensitivity) and state reactivity (negative affect) to social evaluative threat were examined during concurrent reinforcement learning. Lower trait-level punishment sensitivity predicted better reward learning and poorer punishment learning; the opposite pattern was found in more punishment sensitive individuals. Increasing state-level negative affect was directly related to punishment learning accuracy in highly punishment sensitive individuals, but these measures were inversely related in less sensitive individuals. Combined electrophysiological measurement, performance accuracy and computational estimations of learning parameters suggest that trait and state vulnerability to stress alter cortico-striatal functioning during reinforcement learning, possibly mediated via medio-frontal cortical systems.
Prolonged stress exposures and elevated GC levels ( cortisol in humans and corticosterone in rodents) can cause detrimental effects on the brain...body by increasing adrenaline and adrenocorticotropic hormone (ACTH) that produces cortisol . Cells in the amygdala have shown to increase after...restraint stress. Physiology and Behavior, 87(4), 643-649. Gorzalka, B. B., & Hanson, L. A. (1998). Sexual behavior and wet dog shakes in the male rat
Acute and chronic stress, as well as accompanying changes of the hypothalamic-pituitary-adrenal (HPA) axis, affect cognitive processes, including memory. In professional musicians occupational stress and music performance anxiety (MPA) are a major source of concern during a musical career, whereas a boost is to a certain extent necessary for a musical performance. ---------- A protocol was successfully designed to induce acute stress in healthy students while measuring electro-encephalography...
Youssef, Farid F; Dookeeram, Karine; Basdeo, Vasant; Francis, Emmanuel; Doman, Mekaeel; Mamed, Danielle; Maloo, Stefan; Degannes, Joel; Dobo, Linda; Ditshotlo, Phatsimo; Legall, George
While early studies of moral decision making highlighted the role of rational, conscious executive processes involving frontal lobe activation more recent work has suggested that emotions and gut reactions have a key part to play in moral reasoning. Given that stress can activate many of the same brain regions that are important for and connected to brain centres involved in emotional processing we sought to evaluate if stress could influence moral decision making. Sixty-five undergraduate volunteers were randomly assigned to control (n=33) and experimental groups (n=32). The latter underwent the Trier Social Stress Test (TSST) and induction of stress was assessed by measurement of salivary cortisol levels. Subjects were then required to provide a response to thirty moral dilemmas via a computer interface that recorded both their decision and reaction time. Three types of dilemmas were used: non-moral, impersonal moral and personal moral. Using a binary logistic model there were no significant predicators of utilitarian response in non-moral and impersonal moral dilemmas. However the stressed group and females were found to predict utilitarian responses to personal moral dilemmas. When comparing percentage utilitarian responses there were no significant differences noted for the non-moral and impersonal moral dilemmas but the stressed group showed significantly less utilitarian responses compared to control subjects. The stress response was significantly negatively correlated with utilitarian responses. Females also showed significantly less utilitarian responses than males. We conclude that activation of the stress response predisposed participants to less utilitarian responses when faced with high conflict personal moral dilemmas and suggest that this offers further support for dual process theory of moral judgment. We also conclude that females tend to make less utilitarian personal moral decisions compared to males, providing further evidence that there are
Schulz, Kalynn M.; Pearson, Jennifer N.; Neeley, Eric W.; Berger, Ralph; Leonard, Sherry; Adams, Catherine E.; Stevens, Karen E.
Prenatal stress (PS) impairs memory function; however, it is not clear whether PS-induced memory deficits are specific to spatial memory, or whether memory is more generally compromised by PS. Here we sought to distinguish between these possibilities by assessing spatial, recognition and contextual memory function in PS and nonstressed (NS) rodents. We also measured anxiety-related and social behaviors to determine whether our unpredictable PS paradigm generates a behavioral phenotype comparable to previous studies. Female Sprague-Dawley rats were exposed to daily random stress during the last gestational week and behavior tested in adulthood. In males but not females, PS decreased memory for novel objects and novel spatial locations, and facilitated memory for novel object/context pairings. In the elevated zero maze, PS increased anxiety-related behavior only in females. Social behaviors also varied with sex and PS condition. Females showed more anogenital sniffing regardless of stress condition. In contrast, prenatal stress eliminated a male-biased sex difference in nonspecific bodily sniffing by decreasing sniffing in males, and increasing sniffing in females. Finally, PS males but not females gained significantly more weight across adulthood than did NS controls. In summary, these data indicate that PS differentially impacts males and females resulting in sex-specific adult behavioral and bodily phenotypes. PMID:21334352
Blood samples of C. gariepinus were collected every seven days and evaluated for stress by measuring cortisol concentration. The gills and liver were studied and scored for Gill Alteration Index (GAI) and Hepatic Alteration Index (HAI), respectively. There was an increase in cortisol level up to the 7th and 14th day among ...
The study investigated the potential alteration in the level of insulin and adiponectin, as well as the expression of insulin receptors (INSR) and glucose transporter 4 GLUT-4 in chronic restraint stress rats. Sprague-Dawley rats were randomly divided into two groups: the control group and stress group in which the rats were ...
Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.
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.
Weizman, R.; Weizman, A.; Kook, K.A.; Vocci, F.; Deutsch, S.I.; Paul, S.M.
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 [ 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
Scheinost, Dustin; Kwon, Soo Hyun; Lacadie, Cheryl; Sze, Gordon; Sinha, Rajita; Constable, R Todd; Ment, Laura R
Exposure to prenatal and early-life stress results in alterations in neural connectivity and an increased risk for neuropsychiatric disorders. In particular, alterations in amygdala connectivity have emerged as a common effect across several recent studies. However, the impact of prenatal stress exposure on the functional organization of the amygdala has yet to be explored in the prematurely-born, a population at high risk for neuropsychiatric disorders. We test the hypothesis that preterm birth and prenatal exposure to maternal stress alter functional connectivity of the amygdala using two independent cohorts. The first cohort is used to establish the effects of preterm birth and consists of 12 very preterm neonates and 25 term controls, all without prenatal stress exposure. The second is analyzed to establish the effects of prenatal stress exposure and consists of 16 extremely preterm neonates with prenatal stress exposure and 10 extremely preterm neonates with no known prenatal stress exposure. Standard resting-state functional magnetic resonance imaging and seed connectivity methods are used. When compared to term controls, very preterm neonates show significantly reduced connectivity between the amygdala and the thalamus, the hypothalamus, the brainstem, and the insula (p amygdala and the thalamus, the hypothalamus, and the peristriate cortex (p amygdala connectivity associated with preterm birth. Functional connectivity from the amygdala to other subcortical regions is decreased in preterm neonates compared to term controls. In addition, these data, for the first time, suggest that prenatal stress exposure amplifies these decreases.
Bhattacharya, Sharmila; Hosamani, Ravikumar
Altered gravity environments can induce increased oxidative stress in biological systems. Microarray data from our previous spaceflight experiment (FIT experiment on STS-121) indicated significant changes in the expression of oxidative stress genes in adult fruit flies after spaceflight. Currently, our lab is focused on elucidating the role of hypergravity-induced oxidative stress and its impact on the nervous system in Drosophila melanogaster. Biochemical, molecular, and genetic approaches were combined to study this effect on the ground. Adult flies (2-3 days old) exposed to acute hypergravity (3g, for 1 hour and 2 hours) showed significantly elevated levels of Reactive Oxygen Species (ROS) in fly brains compared to control samples. This data was supported by significant changes in mRNA expression of specific oxidative stress and antioxidant defense related genes. As anticipated, a stress-resistant mutant line, Indy302, was less vulnerable to hypergravity-induced oxidative stress compared to wild-type flies. Survival curves were generated to study the combined effect of hypergravity and pro-oxidant treatment. Interestingly, many of the oxidative stress changes that were measured in flies showed sex specific differences. Collectively, our data demonstrate that altered gravity significantly induces oxidative stress in Drosophila, and that one of the organs where this effect is evident is the brain.
Olini, Nadja; Rothfuchs, Iru; Azzinnari, Damiano; Pryce, Christopher R; Kurth, Salome; Huber, Reto
Disturbed sleep and altered sleep homeostasis are core features of many psychiatric disorders such as depression. Chronic uncontrollable stress is considered an important factor in the development of depression, but little is known on how chronic stress affects sleep regulation and sleep homeostasis. We therefore examined the effects of chronic social stress (CSS) on sleep regulation in mice. Adult male C57BL/6 mice were implanted for electrocortical recordings (ECoG) and underwent either a 10-day CSS protocol or control handling (CON). Subsequently, ECoG was assessed across a 24-h post-stress baseline, followed by a 4-h sleep deprivation, and then a 20-h recovery period. After sleep deprivation, CSS mice showed a blunted increase in sleep pressure compared to CON mice, as measured using slow wave activity (SWA, electroencephalographic power between 1-4Hz) during non-rapid eye movement (NREM) sleep. Vigilance states did not differ between CSS and CON mice during post-stress baseline, sleep deprivation or recovery, with the exception of CSS mice exhibiting increased REM sleep during recovery sleep. Behavior during sleep deprivation was not affected by CSS. Our data provide evidence that CSS alters the homeostatic regulation of sleep SWA in mice. In contrast to acute social stress, which results in a faster SWA build-up, CSS decelerates the homeostatic build up. These findings are discussed in relation to the causal contribution of stress-induced sleep disturbance to depression. Copyright © 2017 Elsevier B.V. All rights reserved.
Stress-induced changes in human performance have been thought to result from alterations in the "multidimensional arousal state" of the individual, as indexed by alterations in the physiological and psychological mechanisms controlling performance. I...
Brown, Marishka K.; Chan, May T.; Zimmerman, John E.; Pack, Allan I.; Jackson, Nicholas E.; Naidoo, Nirinjini
Alterations in the quality, quantity and architecture of baseline and recovery sleep have been shown to occur during aging. Sleep deprivation induces endoplasmic reticular (ER) stress and upregulates a protective signaling pathway termed the unfolded protein response (UPR). The effectiveness of the adaptive UPR is diminished by age. Previously, we showed that endogenous chaperone levels altered recovery sleep in Drosophila melanogaster. We now report that acute administration of the chemical chaperone sodium 4-phenylbutyrate (PBA) reduces ER stress and ameliorates age-associated sleep changes in Drosophila. PBA consolidates both baseline and recovery sleep in aging flies. The behavioral modifications of PBA are linked to its suppression of ER stress. PBA decreased splicing of x-box binding protein 1 (XBP1) and upregulation of phosphorylated elongation initiation factor 2 α (p-eIF2α), in flies that were subjected to sleep deprivation. We also demonstrate that directly activating ER stress in young flies fragments baseline sleep and alters recovery sleep. Alleviating prolonged/sustained ER stress during aging contributes to sleep consolidation and improves recovery sleep/ sleep debt discharge. PMID:24444805
Brown, Marishka K; Chan, May T; Zimmerman, John E; Pack, Allan I; Jackson, Nicholas E; Naidoo, Nirinjini
Alterations in the quality, quantity, and architecture of baseline and recovery sleep have been shown to occur during aging. Sleep deprivation induces endoplasmic reticular (ER) stress and upregulates a protective signaling pathway termed the unfolded protein response. The effectiveness of the adaptive unfolded protein response is diminished by age. Previously, we showed that endogenous chaperone levels altered recovery sleep in Drosophila melanogaster. We now report that acute administration of the chemical chaperone sodium 4-phenylbutyrate (PBA) reduces ER stress and ameliorates age-associated sleep changes in Drosophila. PBA consolidates both baseline and recovery sleep in aging flies. The behavioral modifications of PBA are linked to its suppression of ER stress. PBA decreased splicing of X-box binding protein 1 and upregulation of phosphorylated elongation initiation factor 2 α, in flies that were subjected to sleep deprivation. We also demonstrate that directly activating ER stress in young flies fragments baseline sleep and alters recovery sleep. Alleviating prolonged or sustained ER stress during aging contributes to sleep consolidation and improves recovery sleep or sleep debt discharge. Copyright © 2014 Elsevier Inc. All rights reserved.
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
Full Text Available In the second part of twentieth century anabolic-androgenic steroids were introduced into doping practice and received continuously increasing significance. In order to prove the usage of doping substances, the determination of steroid profile in the urine came into practice. Several factors may be responsible for alterations in the normal steroid profile for example age, sex and diet. The aim of this study was to find out, whether the psychological stress may cause modifications in the steroid profile and T/Et ratio. The effect of physical activity was also considered. The steroid profile was determined in the group of 34 students being in non-stress conditions and under stress immediately before an important university exam. The intensity of stress was rated by self-reported questionnaire. The GC/MS method was applied to determine the steroid profile in the urine samples. The results of the experiment have shown that psychological stress may cause significant changes in the steroid profile, especially in females. Physical activity, independently of stress significantly modified the steroid profile. In summary, observed changes in steroid profile suggest, that major fluctuations of T/Et and A/E ratios under the influence of stressogenic factors and physical activity are unlikely.
Tymen, Stéphanie D.; Rojas, Isolde G.; Zhou, Xiaofeng; Fang, Zong Juan; Zhao, Yan; Marucha, Phillip T.
Previous studies reported that stress delays wound healing, impairs bacterial clearance, and elevates the risk for opportunistic infection. Neutrophils and macrophages are responsible for the removal of bacteria present at the wound site. The appropriate recruitment and functions of these cells are necessary for efficient bacterial clearance. In our current study we found that restraint stress induced an excessive recruitment of neutrophils extending the inflammatory phase of healing, and the gene expression of neutrophil attracting chemokines MIP-2 and KC. However, restraint stress did not affect macrophage infiltration. Stress decreased the phagocytic abilities of phagocytic cells ex vivo, yet it did not affect superoxide production. The cell surface expression of adhesion molecules CD11b and TLR4 were decreased in peripheral blood monocytes in stressed mice. The phenotype of macrophages present at the wound site was also altered. Gene expression of markers of pro-inflammatory classically activated macrophages, CXCL10 and CCL5, were down-regulated; as were markers associated with wound healing macrophages, CCL22, IGF-1, RELMα; and the regulatory macrophage marker, chemokine CCL1. Restraint stress also induced up-regulation of IL10 gene expression. In summary, our study has shown that restraint stress suppresses the phenotype shift of the macrophage population, as compared to the changes observed during normal wound healing, while the number of macrophages remains constant. We also observed a general suppression of chemokine gene expression. Modulation of the macrophage phenotype could provide a new therapeutic approach in the treatment of wounds under stress conditions in the clinical setting. PMID:22884902
Reis, Adolfo R; Jacobs, Silvana; Menegotto, Pâmela R; Silveira, Patrícia P; Lucion, Aldo B
Neonatal handling is an experimental procedure used to analyze the effects of environmental interventions during early postpartum days (PPD). Long-lasting effects of repeated stress exposure in the neonatal period on the maternal side are poorly studied in this model. The aim of this study was to verify if handling the pups induces enduring effects on damśstress responses, increasing their risk for depression. Dams were divided into two groups (NH-Non-handled and H-Handled) based on the handling procedure (pups were handled for 1 min/per day from PPD1-PPD10) and then subdivided into four groups (NH, NH + S, H, and H + S) based on the exposure or not to restraint stress after weaning (1 hr/per day for 7 days, PPD22-PPD28). We analyzed damśbehavior in the forced swimming test (FST PPD29-PPD30), plasma basal corticosterone and BDNF levels, as well as adrenal weight (PPD31). The results show that handling alters the stress response of dams to acute and chronic stress, as evidenced by dams of the H group having increased immobility in the first day of FST (p sensibility of the maternal organism to the chronic stress applied after weaning (p < .05). We show that handling may induce a long-lasting effect on maternal stress response; these changes in the damśemotional reactivity increase their susceptibility for the development of psychiatric disorders such as depression. © 2016 Wiley Periodicals, Inc. Dev Psychobiol 58: 614-622, 2016. © 2016 Wiley Periodicals, Inc.
Weiskopf, Daniela; Schwanninger, Angelika; Weinberger, Birgit
APCs operate frequently under oxidative stress induced by aging, tissue damage, pathogens, or inflammatory responses. Phagocytic cells produce peroxides and free-radical species that facilitate pathogen clearance and can in the case of APCs, also lead to oxidative modifications of antigenic...... proteins and peptides. Little information is available presently about the consequences of such modifications on the immune response. To model oxidative modification of an immunodominant antigenic peptide, we oxidized the methionine residue of the human CMV pp65(495-503) (NLVPMVATV) peptide...... of antigenic peptides may affect T cell responses severely by binding T cell clones with different affinity. This may lead to an altered immune response against infectious agents as well as against tumor or autoantigens under oxidative stress conditions....
Full Text Available Decades of research have demonstrated that physical stress (PS stimulates bone remodeling and affects bone structure and function through complex mechanotransduction mechanisms. Recent research has laid ground to the hypothesis that mental stress (MS also influences bone biology, eventually leading to osteoporosis and increased bone fracture risk. These effects are likely exerted by modulation of hypothalamic–pituitary–adrenal axis activity, resulting in an altered release of growth hormones, glucocorticoids and cytokines, as demonstrated in human and animal studies. Furthermore, molecular cross talk between mental and PS is thought to exist, with either synergistic or preventative effects on bone disease progression depending on the characteristics of the applied stressor. This mini review will explain the emerging concept of MS as an important player in bone adaptation and its potential cross talk with PS by summarizing the current state of knowledge, highlighting newly evolving notions (such as intergenerational transmission of stress and its epigenetic modifications affecting bone and proposing new research directions.
To determine the relationship of stress and academic performance in first year medical students and to identify sources of stress, levels of stress and relevant coping strategies. Mixed method sequential. Allama Iqbal Medical College, Lahore, from March to December 2010. Survey questionnaire and in-depth interviews were carried out in the first year students with their consent. Two hundred and fifty students were surveyed, out of whom 120 students responded. Twelve students with their consent were interviewed. Non-probability purposive sampling was employed for both types of data collection. SPSS version 20 was used. The qualitative data generated through structured in-depth interviews, were analyzed by content analysis. Low level of stress was found in 7.5% (score ‹150), moderate level of stress was present in 71.67% (score between 150 and 300), and high level of stress was observed in 20.83% (score ›300) of the students. There is moderate negative (-0.583) and significant (p academic performance and sources of stress. Similarly there is moderate negative (-0.478) and significant (p academic performance and levels of stress. There was strong positive (0.799) and significant (p stress level and number of stress sources. The study showed a diversity of stress sources and a high level of stress in the medical students. The results also show that higher level of stress is associated with poor academic performance.
Costa, Isis da Silva; Gamundí, Antoni; Miranda, José G Vivas; França, Lucas G Souza; De Santana, Charles Novaes; Montoya, Pedro
Fibromyalgia is a common chronic pain condition that exerts a considerable impact on patients' daily activities and quality of life. Objectives: The main objective of the present study was to evaluate kinematic parameters of gait, functional performance, and balance in women with fibromyalgia syndrome. Methods: The study included 26 female patients with fibromyalgia (49.2 ± 8.0 years) according to the criteria of the American College of Rheumatology, as well as 16 pain-free women (43.5 ± 8.5 years). Gait and balance parameters were extracted from video recordings of participants performing several motor tasks. Non-linear dynamic of body sway time series was also analyzed by computing the Hurst exponent. In addition, functional performance and clinical pain were obtained by using standardized motor tests (Berg's balance scale, 6-min walking test, timed up and go task, Romberg's balance test) and self-report questionnaires (Fibromyalgia Impact Questionnaire). Results: Walking speed was significantly diminished ( p cycle frequency ( p assessment of both psychological responses to pain and physical impairments during postural control and gait.
Full Text Available Aim: Mammary tumors are the most prevalent type of neoplasms in canines. Even though cancer induced metabolic alterations are well established, the clinical data describing the metabolic profiles of animal tumors is not available. Hence, our present investigation was carried out with the aim of studying changes in carbohydrate metabolism along with the level of oxidative stress in canine mammary tumors. Materials and Methods: Fresh mammary tumor tissues along with the adjacent healthy tissues were collected from the college surgical ward. The levels of thiobarbituric acid reactive substances (TBARS, glutathione, protein, hexose, hexokinase, glucose-6-phosphatase, fructose-1, 6-bisphosphatase, and glucose-6-phosphate dehydrogenase (G6PD were analyzed in all the tissues. The results were analyzed statistically. Results: More than two-fold increase in TBARS and three-fold increase in glutathione levels were observed in neoplastic tissues. Hexokinase activity and hexose concentration (175% was found to be increased, whereas glucose-6-phosphatase (33%, fructose-1, 6-bisphosphatase (42%, and G6PD (5 fold activities were reduced in tumor mass compared to control. Conclusion: Finally, it was revealed that lipid peroxidation was increased with differentially altered carbohydrate metabolism in canine mammary tumors.
In summary, employee empowerment is a necessary component of the corporate culture because it increases productivity and the rate of employee retention. It simultaneously diminished employee job stress and associated costs.
Dockterman, David; Weber, Chris
There is compelling evidence that stressing goals leads to stress and negatively affects the very objectives that educators are trying to achieve. Reaching testing goals matter, but if we are not careful, the goal of educating children for the 21st century becomes subsumed by the narrow measures meant to track progress. Performance measures become…
McClernon, Christopher K.; McCauley, Michael E.; O'Connor, Paul E.; Warm, Joel S.
The article of record as published may be found at http://dx.doi.org/10.1177/00187€0811405317. This study investigated whether stress training introduced during the acquisition of simulator-based flight skills enhances pilot performance during subsequent stressful flight operations in an actual aircraft.
Huang, Xunbing; Whitman, Douglas W; Ma, Jingchuan; McNeill, Mark Richard; Zhang, Zehua
We reared Oedaleus asiaticus grasshoppers under four different single-plant diets to examine the relationships among diet, performance, stress, and transcription patterns. Grasshoppers fed only Artemisia frigida (Asteraceae) were stressed, as indicated by their lower growth, size, development, and survival, in comparison to grasshoppers fed on any of three grasses, Cleistogenes squarrosa, Leymus chinensis, or Stipa krylovii (all Poaceae). We then used transcriptome analysis to examine how gene expression levels in O. asiaticus were altered by feeding on these diets. Nymphs fed A. frigida had the largest variation in gene expression profiles with a total of 299 genes significantly up- or down-regulated compared to those feeding on the three grasses: down-regulated genes included those involved in cuticle biosynthesis, DNA replication, biosynthesis and metabolism of nutrition. The up-regulated genes included stress-resistant and detoxifying enzymes. GO and KEGG enrichment analysis also showed that feeding on A. frigida could down-regulate biosynthesis and metabolism related pathways, and up-regulate stress-resistant and detoxification terms and pathways. Our results show that diet significantly altered gene-expression, and that unfavorable, stressful diets induce more transcriptional changes than favorable diets. Altered gene-expression represents phenotypic plasticity, and many such changes appear to be evolved, adaptive responses. The ease and regularity by which individuals shift phenotypes via altered transcription suggests that populations consist not of similar, fixed phenotypes, but of a collection of ever-changing, divergent phenotypes.
Remus, Jennifer L; Stewart, Luke T; Camp, Robert M; Novak, Colleen M; Johnson, John D
There is growing evidence that metabolic stressors increase an organism's risk of depression. Chronic mild stress is a popular animal model of depression and several serendipitous findings have suggested that food deprivation prior to sucrose testing in this model is necessary to observe anhedonic behaviors. Here, we directly tested this hypothesis by exposing animals to chronic mild stress and used an overnight 2-bottle sucrose test (food ad libitum) on Day 5 and 10, then food and water deprive animals overnight and tested their sucrose consumption and preference in a 1-hr sucrose test the following morning. Approximately 65% of stressed animals consumed sucrose and showed a sucrose preference similar to nonstressed controls in an overnight sucrose test, and 35% showed a decrease in sucrose intake and preference. Following overnight food and water deprivation the previously "resilient" animals showed a significant decrease in sucrose preference and greatly reduced sucrose intake. In addition, we evaluated whether the onset of anhedonia following food and water deprivation corresponds to alterations in corticosterone, epinephrine, circulating glucose, or interleukin-1 beta (IL-1β) expression in limbic brain areas. Although all stressed animals showed adrenal hypertrophy and elevated circulating epinephrine, only stressed animals that were food deprived were hypoglycemic compared with food-deprived controls. Additionally, food and water deprivation significantly increased hippocampus IL-1β while food and water deprivation only increased hypothalamus IL-1β in stress-susceptible animals. These data demonstrate that metabolic stress of food and water deprivation interacts with chronic stressor exposure to induce physiological and anhedonic responses. (c) 2015 APA, all rights reserved).
Ganster, Daniel C.; Kiersch, Christa E.; Marsh, Rachel E.; Bowen, Angela
Even though reward systems play a central role in the management of organizations, their impact on stress and the well-being of workers is not well understood. We review the literature linking performance-based reward systems to various indicators of employee stress and well-being. Well-controlled experiments in field settings suggest that certain…
Khan, Ahmad Raza; Hansen, Brian; Wiborg, Ove
Depression is a leading cause of disability worldwide and causes significant microstructural alterations in stress-sensitive brain regions. However, the potential recovery of these microstructural alterations has not previously been investigated, which we, therefore, set out to do using diffusion...... MRI (d-MRI) in the chronic mild stress (CMS) rat model of depression. This study reveals significant microstructural alterations after 8 weeks of recovery, in the opposite direction to change induced by stress in the acute phase of the experiment. Such findings may be useful in the prognosis...... of depression or for monitoring treatment response....
Taren, Adrienne A.; Gianaros, Peter J.; Greco, Carol M.; Lindsay, Emily K.; Fairgrieve, April; Brown, Kirk Warren; Rosen, Rhonda K.; Ferris, Jennifer L.; Julson, Erica; Marsland, Anna L.; Bursley, James K.; Ramsburg, Jared; Creswell, J. David
Recent studies indicate that mindfulness meditation training interventions reduce stress and improve stress-related health outcomes, but the neural pathways for these effects are unknown. The present research evaluates whether mindfulness meditation training alters resting state functional connectivity (rsFC) of the amygdala, a region known to coordinate stress processing and physiological stress responses. We show in an initial discovery study that higher perceived stress over the past month...
Hamilton, Linda H.; Kella, John J.
Performing Arts Psychology has recently emerged as a unique subspecialty comparable to that of Sports Psychology. Attention has been focused on problems common to all performers (e.g., performance anxiety); however, the various stresses within each art form often remain hidden from view. To assess the psychological aspects of different art forms,…
Patri et al. 2009). Recently, increased oxidative stress and .... increased oxidative stress. Ascorbic acid is a water-soluble antioxidant that acts as the body's primary defense against peroxyl radicals formed in the aqueous phase.
Zoladz, Phillip R; Dailey, Alison M; Nagle, Hannah E; Fiely, Miranda K; Mosley, Brianne E; Brown, Callie M; Duffy, Tessa J; Scharf, Amanda R; Earley, McKenna B; Rorabaugh, Boyd R
FK506 binding protein 51 (FKBP5) is a co-chaperone of heat shock protein 90 and significantly influences glucocorticoid receptor sensitivity. Single nucleotide polymorphisms (SNPs) in the FKBP5 gene are associated with altered hypothalamus-pituitary-adrenal (HPA) axis function, changes in the structure and function of several cognitive brain areas, and increased susceptibility to post-traumatic stress disorder, major depression, bipolar disorder and suicidal events. The mechanisms underlying these associations are largely unknown, but it has been speculated that the influence of these SNPs on emotional memory systems may play a role. In the present study, 112 participants were exposed to the socially evaluated cold pressor test (stress) or control (no stress) conditions immediately prior to learning a list of 42 words. Participant memory was assessed immediately after learning (free recall) and 24 h later (free recall and recognition). Participants provided a saliva sample that enabled the genotyping of three FKBP5 polymorphisms: rs1360780, rs3800373 and rs9296158. Results showed that stress impaired immediate recall in risk allele carriers. More importantly, stress enhanced long-term recall and recognition memory in non-carriers of the risk alleles, effects that were completely absent in risk allele carriers. Follow-up analyses revealed that memory performance was correlated with salivary cortisol levels in non-carriers, but not in carriers. These findings suggest that FKBP5 risk allele carriers may possess a sensitized stress response system, perhaps specifically for stress-induced changes in corticosteroid levels, which might aid our understanding of how SNPs in the FKBP5 gene confer increased risk for stress-related psychological disorders and their related phenotypes. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.
Sauerland, Melanie; Raymaekers, Linsey H C; Otgaar, Henry; Memon, Amina; Waltjen, Thijs T; Nivo, Maud; Slegers, Chiel; Broers, Nick J; Smeets, Tom
In the eyewitness identification literature, stress and arousal at the time of encoding are considered to adversely influence identification performance. This assumption is in contrast with findings from the neurobiology field of learning and memory, showing that stress and stress hormones are critically involved in forming enduring memories. This discrepancy may be related to methodological differences between the two fields of research, such as the tendency for immediate testing or the use of very short (1-2 hours) retention intervals in eyewitness research, while neurobiology studies insert at least 24 hours. Other differences refer to the extent to which stress-responsive systems (i.e., the hypothalamic-pituitary-adrenal axis) are stimulated effectively under laboratory conditions. The aim of the current study was to conduct an experiment that accounts for the contemporary state of knowledge in both fields. In all, 123 participants witnessed a live staged theft while being exposed to a laboratory stressor that reliably elicits autonomic and glucocorticoid stress responses or while performing a control task. Salivary cortisol levels were measured to control for the effectiveness of the stress induction. One week later, participants attempted to identify the thief from target-present and target-absent line-ups. According to regression and receiver operating characteristic analyses, stress did not have robust detrimental effects on identification performance. Copyright © 2016 John Wiley & Sons, Ltd. © 2016 The Authors Behavioral Sciences & the Law Published by John Wiley & Sons Ltd. © 2016 The Authors Behavioral Sciences & the Law Published by John Wiley & Sons Ltd.
George, Sophie A; Rodriguez-Santiago, Mariana; Riley, John; Abelson, James L; Floresco, Stan B; Liberzon, Israel
Exposure to stressful or traumatic events is associated with increased vulnerability to post-traumatic stress disorder (PTSD). This vulnerability may be partly mediated by effects of stress on the prefrontal cortex (PFC) and associated circuitry. The PFC mediates critical cognitive functions, including cognitive flexibility, which reflects an organism's ability to adaptively alter behavior in light of changing contingencies. Prior work suggests that chronic or acute stress exerts complex effects on different forms of cognitive flexibility, via actions on the PFC. Similarly, PFC dysfunction is reported in PTSD, as are executive function deficits. Animal models that permit study of the effects of stress/trauma on cognitive flexibility may be useful in illuminating ways in which stress-linked cognitive changes contribute to PTSD. Here, we examined the behavioral effects of a rodent model of PTSD - single prolonged stress (SPS) - on performance of two forms of cognitive flexibility: reversal learning and strategy set-shifting. SPS did not impair acquisition of either a response or visual-cue discrimination but did cause slight impairments in the retrieval of the visual-cue rule. During response discrimination reversal, SPS rats made more perseverative errors. In comparison, during set-shifting from the visual-cue to response discrimination, SPS rats did not show enhanced perseveration, but did display increased never-reinforced errors, indicative of impairment in selecting a novel strategy. These data demonstrate that SPS leads to a complex and intriguing pattern of deficits in flexible responding and suggest that impairments in executive functioning associated with PTSD could, in part, be a neuro-cognitive consequence of trauma exposure. Copyright © 2015 Elsevier B.V. All rights reserved.
For a large number of veterans, war does not end after they are removed from a combat zone. Traumatic stress affects nearly all veterans, but while the majority of veterans learn to live with their experiences, for some veterans traumatic stress seethes inside. In this dissertation posttraumatic
Kiss, Douglas; Ambeskovic, Mirela; Montina, Tony; Metz, Gerlinde A S
Stress is among the primary causes of mental health disorders, which are the most common reason for disability worldwide. The ubiquity of these disorders, and the costs associated with them, lends a sense of urgency to the efforts to improve prediction and prevention. Down-stream metabolic changes are highly feasible and accessible indicators of pathophysiological processes underlying mental health disorders. Here, we show that remote and cumulative ancestral stress programs central metabolic pathways linked to mental health disorders. The studies used a rat model consisting of a multigenerational stress lineage (the great-great-grandmother and each subsequent generation experienced stress during pregnancy) and a transgenerational stress lineage (only the great-great-grandmother was stressed during pregnancy). Urine samples were collected from adult male F4 offspring and analyzed using 1 H NMR spectroscopy. The results of variable importance analysis based on random variable combination were used for unsupervised multivariate principal component analysis and hierarchical clustering analysis, as well as metabolite set enrichment analysis (MSEA) and pathway analysis. We identified distinct metabolic profiles associated with the multigenerational and transgenerational stress phenotype, with consistent upregulation of hippurate and downregulation of tyrosine, threonine, and histamine. MSEA and pathway analysis showed that these metabolites are involved in catecholamine biosynthesis, immune responses, and microbial host interactions. The identification of metabolic signatures linked to ancestral programming assists in the discovery of gene targets for future studies of epigenetic regulation in pathogenic processes. Ultimately, this research can lead to biomarker discovery for better prediction and prevention of mental health disorders.
Hayase, T; Yamamoto, Y; Yamamoto, K
The present study evaluated the effects of mixed opioid drugs on the severity of cocaine (COCA) toxicity by examining stress-related behavioral alterations in mice. In order to ascertain the strength of the stress, the continuous observation of the behavioral symptoms in the cage and the forced swimming test (Porsolt test) were performed in the COCA (75 mg/kg, i.p.)-treated groups, with or without the mixed mu-kappa receptor-related opioid drugs, buprenorphine (BUP) and pentazocine (PEN). Using the high-sensitivity activity measuring instrument Supermex, both the spontaneous behaviors in the cage and the forced swimming behaviors in the water were assessed as activity counts. The behavioral alterations in the COCA-treated groups were compared with a group of mice given a 10 min immobilization stress (IM group). In the COCA-only group, a prolonged increase in the spontaneous behaviors accompanied by convulsive seizures was observed even in the surviving mice, unlike in the IM group. However, an acceleration of behavioral despair in the Porsolt test similar to that observed in the IM group was observed in the COCA group after the disappearance of the acute toxic symptoms (5 hours after the COCA treatment). Among the opioid-treated groups, the mortality rate was attenuated only in the COCA-BUP (0.25 mg/kg, i.p.) group. In the COCA-BUP group, a prolonged suppression of the morbid hyperactivity in the cage except for the convulsive seizures, and a normalization of the swimming behavior in the Porsolt test were observed in the survivors. On the other hand, in the COCA-PEN (5 mg/kg, i.p.) group, the swimming behavior in the Porsolt test was abnormally increased in addition to the prolonged morbid hyperactivity in the cage. Therefore, the COCA-induced stress-related behaviors were normalized in the group of mice treated with BUP, a group with a good prognosis.
Amanda R. Meier
Full Text Available Multitrophic species interactions are shaped by both top-down and bottom-up factors. Belowground symbionts of plants, such as arbuscular mycorrhizal fungi (AMF, can alter the strength of these forces by altering plant phenotype. For example, AMF-mediated changes in foliar toxin and nutrient concentrations may influence herbivore growth and fecundity. In addition, many specialist herbivores sequester toxins from their host plants to resist natural enemies, and the extent of sequestration varies with host plant secondary chemistry. Therefore, by altering plant phenotype, AMF may affect both herbivore performance and their resistance to natural enemies. We examined how inoculation of plants with AMF influences toxin sequestration and performance of two specialist herbivores feeding upon four milkweed species (Asclepias incarnata, A. curassavica, A. latifolia, A. syriaca. We raised aphids (Aphis nerii and caterpillars (Danaus plexippus on plants for 6 days in a fully factorial manipulation of milkweed species and level of AMF inoculation (zero, medium, and high. We then assessed aphid and caterpillar sequestration of toxins (cardenolides and performance, and measured defensive and nutritive traits of control plants. Aphids and caterpillars sequestered higher concentrations of cardenolides from plants inoculated with AMF across all milkweed species. Aphid per capita growth rates and aphid body mass varied non-linearly with increasing AMF inoculum availability; across all milkweed species, aphids had the lowest performance under medium levels of AMF availability and highest performance under high AMF availability. In contrast, caterpillar survival varied strongly with AMF availability in a plant species-specific manner, and caterpillar growth was unaffected by AMF. Inoculation with AMF increased foliar cardenolide concentrations consistently among milkweed species, but altered aboveground biomasses and foliar phosphorous concentrations in a plant
Full Text Available Psychological stress may alter gastrointestinal absorptive function by increasing the quantity of intestinal free radicals or by lowering endogenous intestinal free radical scavenging capacity. Vitamin E has been shown to be a potent endogenous antioxidant and free radical scavenger under both physiological and pathological conditions. The purpose of this study was to determine whether cold wrap restraint stress altered in vivo intestinal fluid absorption in rats, and whether vitamin E administration prior to the induction of cold wrap restraint stress could prevent such changes in intestinal secretion. Jejunal, ileal and colonic fluid and electrolyte transport rates were measured in vivo using an isolated loop technique. Cold wrap restraint stress reduced in vivo fluid absorption in the ileum and colon, but not in the jejunum. Administration of vitamin E prior to the cold wrap restraint stress procedure completely prevented this alteration of ileal and colonic fluid absorption.
Fagundes, N S; Pereira, R; Bortoluzzi, C; Rafael, J M; Napty, G S; Barbosa, J G M; Sciencia, M C M; Menten, J F M
Sorghum grain can be used to replace corn in broiler diets. However, the effects related to an abrupt change between these grains are not yet clear. The aim of this study was to evaluate the performance and intestinal health of broilers fed diets containing corn and/or sorghum during different periods of rearing. To accomplish this aim, 2100 male chicks were fed the following experimental diets: C100% (corn-based diet); S100% (sorghum-based diet); C:S50% (diet based on corn and sorghum 1:1); PC-S (corn-based diet in the pre-starter phase and sorghum-based diet in subsequent phases); and PS-C (sorghum-based diet in the pre-starter phase and corn-based diet in subsequent phases). The study was conducted with two simultaneous trials in a randomized block design as follows: a performance trial up to 40 days occurred in floor pens (n = 8), and the metabolism trial occurred in cages (n = 10). Performance, jejunal morphometry, number of goblet cells, apparent metabolizable energy (AME), apparent metabolizable energy corrected for nitrogen (AMEn) and the coefficient of apparent metabolizability of dry matter (CMDM) of the diets, and the intestinal microbiota of small intestine and caeca at 10 and 21 days of age (16S gene sequencing) were evaluated. The different experimental diets did not affect performance, jejunal epithelium, AME, AMEn or CMDM. However, the experimental diets altered the percentages of the genera Clostridium, Weissella, Bacillus and Alkaliphilus in the small intestine. In addition, the genera Lactobacillus and Desulfotomaculum in the caeca were altered. The age also affected the microbiota of the intestinal segments. In conclusion, feeding sorghum in place of corn as well as the grain change after the pre-starter phase does not alter broiler performance. However, sorghum alters the intestinal microbiota, resulting in a lower percentage of Clostridium and a higher percentage of Lactobacillus in the small intestine and caeca, respectively. Journal of
Delahaij, R.; Gaillard, A.W.K.
To be able to predict which persons are capable to perform under acute stress is important for the selection and training of professionals in the military, police, and fire- fighting domain. The present study examines how individual differences in coping (style, efficacy, and behavior) explain
Brorson Fich, Lars; Jönsson, Peter; Kirkegaard, Poul Henning
influences these mechanisms. The question that this study attempts to start addressing is therefore whether certain design, characteristics of indoor spaces can make a difference to the physiological stress response as well. Using a virtual version of the Trier Social Stress Test, in which the space...... is computer generated and properties of the space therefore can be systematically varied, we measured saliva cortisol and heart rate variability in participants in a closed room versus a room with openings. As shown by a significant linear contrast interaction between groups and TSST conditions, participants...... in the closed room responded with more pronounced cortisol reactivity to stress induction, and continued to show higher levels throughout recovery, compared to participants in the open room. No differences were found regarding any part of the autonomic nervous system....
Cavanagh, James F.; Frank, Michael J.; Allen, John J. B.
To examine how stress affects cognitive functioning, individual differences in trait vulnerability (punishment sensitivity) and state reactivity (negative affect) to social evaluative threat were examined during concurrent reinforcement learning. Lower trait-level punishment sensitivity predicted better reward learning and poorer punishment learning; the opposite pattern was found in more punishment sensitive individuals. Increasing state-level negative affect was directly related to punishme...
Coronary artery disease (CAD) is a multifactorial disease caused by the interplay of environmental risk factors with multiple predisposing genes. The present study was undertaken to evaluate the role of DNA repair efficiency and oxidative stress and antioxidant status in CAD patients. Malonaldehyde (MDA), which is an ...
Coronary artery disease (CAD) is a multifactorial disease caused by the interplay of environmental risk factors with multiple predisposing genes. The present study was undertaken to evaluate the role of DNA repair efficiency and oxidative stress and antioxidant status in CAD patients. Malonaldehyde (MDA), which is an ...
Mar 13, 2013 ... endogenous and exogenous factors such as oxidative stress, age, smoking, hypertension, hyperlipidemia and diabetes mellitus (Andreassi and Botto 2003). Such damages, if left unrepaired, can cause mutations, which can lead to disease. To prevent accumulation of mutations and the production of.
Different factors contribute to this situation; the most important are a consequence of increased temperature and humidity that result in a decreased expression of ... Plasma progesterone levels can be increased or decreased depending on whether the heat stress is acute or chronic, and on the metabolic state of the animal.
Nishigawa, Takuma; Nagamachi, Satsuki; Ikeda, Hiromi; Chowdhury, Vishwajit S; Furuse, Mitsuhiro
It is well known that maternal stress during the gestation and lactation periods induces abnormal behavior in the offspring and causes a lowering of the offspring's body weight. Various causes of maternal stress during the lactation period, relating to, for example, maternal nutritional status and reduced maternal care, have been considered. However, little is known about the effects on milk of maternal stress during the lactation period. The current study aimed to determine whether free amino acids, with special reference to sulfur-containing amino acids in milk, are altered by restraint stress in lactating mice. The dams in the stress group were restrained for 30 min at postnatal days 2, 4, 6, 8, 10 and 12. Restraint stress caused a reduction in the body weight of lactating mice. The concentration of taurine and cystathionine in milk was significantly higher in the stress group, though stress did not alter their concentration in maternal plasma. The ratio of taurine concentration in milk to its concentration in maternal plasma was significantly higher in the stress group, suggesting that stress promoted taurine transportation into milk. Furthermore, taurine concentration in milk was positively correlated with corticosterone levels in plasma. In conclusion, restraint stress in lactating mice caused the changes in the metabolism and in the transportation of sulfur-containing amino acids and resulted in higher taurine concentration in milk. Taurine concentration in milk could also be a good parameter for determining stress status in dams.
Full Text Available Food consumption and preferences may be shaped by exposure to stressful environments during sensitive periods in development, and even small changes in consumption can have important effects on long term health. Adolescence is increasingly recognized as a sensitive period, in which adverse experiences can alter development, but the specific programming effects that may occur during adolescence remain incompletely understood. The current study seeks to explore the effects of stress during late adolescence on consumption of a palatable, high-fat, high-sugar food in adulthood-under basal conditions, as well following acute stress. Male Long-Evans rats were exposed to a regimen of variable stress for seven days in late adolescence (PND 45-51. During the stress regimen, stressed animals gained significantly less weight than control animals, but weight in adulthood was unaffected by adolescent stress. Palatable food consumption differed between experimental groups, and the direction of effect depended on context; stressed rats ate significantly more palatable food than controls upon first exposure, but ate less following an acute stressor. Leptin levels and exploratory behaviors did not differ between stressed and non-stressed groups, suggesting that other factors regulate preference for a palatable food. Altered food consumption following adolescent stress suggests that rats remain sensitive to stress during late adolescence, and that adult feeding behavior may be affected by previous adverse experiences. Such programming effects highlight adolescence as a period of plasticity, with the potential to shape long term food consumption patterns and preferences.
Bhansali, Shipra; Bhansali, Anil; Walia, Rama; Saikia, Uma Nahar; Dhawan, Veena
Hyperglycemia-mediated oxidative stress impedes cell-reparative process like autophagy, which has been implicated in impairment of β-cell function in type 2 diabetes mellitus (T2DM). However, the role of mitophagy (selective mitochondrial autophagy) in progression of hyperglycemia remains elusive. This study aimed to assess the impact of increasing severity of hyperglycemia on mitochondrial stress and mitophagy. A case-control study included healthy controls, subjects with prediabetes, newly diagnosed T2DM (NDT2DM) and advanced duration of T2DM (ADT2DM) ( n = 20 each). Mitochondrial stress indices, transcriptional and translational expression of mitophagy markers ( PINK1, PARKIN, MFN2, NIX, LC3-II , and LAMP-2 ) and transmission electron microscopic (TEM) studies were performed in peripheral blood mononuclear cells. With mild hyperglycemia in subjects with prediabetes, to moderate to severe hyperglycemia in NDT2DM and ADT2DM, a progressive rise in mitochondrial oxidative stress was observed. Prediabetic subjects exhibited significantly increased expression of mitophagy-related markers and showed a positive association with HOMA-β, whereas, patients with NDT2DM and ADT2DM demonstrated decreased expression, with a greater decline in ADT2DM subjects. TEM studies revealed significantly reduced number of distorted mitochondria in prediabetics, as compared to the T2DM patients. In addition, receiver operating characteristic analysis showed HbA 1C > 7% (53 mmol/mol) was associated with attenuated mitophagy. Increasing hyperglycemia is associated with progressive rise in oxidative stress and altered mitochondrial morphology. Sustenance of mitophagy at HbA 1C < 7% (53 mmol/mol) strengthens the rationale of achieving HbA 1C below this cutoff for good glycemic control. An "adaptive" increase in mitophagy may delay progression to T2DM by preserving the β-cell function in subjects with prediabetes.
Full Text Available Background and aimHyperglycemia-mediated oxidative stress impedes cell-reparative process like autophagy, which has been implicated in impairment of β-cell function in type 2 diabetes mellitus (T2DM. However, the role of mitophagy (selective mitochondrial autophagy in progression of hyperglycemia remains elusive. This study aimed to assess the impact of increasing severity of hyperglycemia on mitochondrial stress and mitophagy.Design and methodsA case–control study included healthy controls, subjects with prediabetes, newly diagnosed T2DM (NDT2DM and advanced duration of T2DM (ADT2DM (n = 20 each. Mitochondrial stress indices, transcriptional and translational expression of mitophagy markers (PINK1, PARKIN, MFN2, NIX, LC3-II, and LAMP-2 and transmission electron microscopic (TEM studies were performed in peripheral blood mononuclear cells.ResultsWith mild hyperglycemia in subjects with prediabetes, to moderate to severe hyperglycemia in NDT2DM and ADT2DM, a progressive rise in mitochondrial oxidative stress was observed. Prediabetic subjects exhibited significantly increased expression of mitophagy-related markers and showed a positive association with HOMA-β, whereas, patients with NDT2DM and ADT2DM demonstrated decreased expression, with a greater decline in ADT2DM subjects. TEM studies revealed significantly reduced number of distorted mitochondria in prediabetics, as compared to the T2DM patients. In addition, receiver operating characteristic analysis showed HbA1C > 7% (53 mmol/mol was associated with attenuated mitophagy.ConclusionIncreasing hyperglycemia is associated with progressive rise in oxidative stress and altered mitochondrial morphology. Sustenance of mitophagy at HbA1C < 7% (53 mmol/mol strengthens the rationale of achieving HbA1C below this cutoff for good glycemic control. An “adaptive” increase in mitophagy may delay progression to T2DM by preserving the β-cell function in subjects with prediabetes.
Zheng, Wanglong; Wang, Bingjie; Si, Mengxue; Zou, Hui; Song, Ruilong; Gu, Jianhong; Yuan, Yan; Liu, Xuezhong; Zhu, Guoqiang; Bai, Jianfa; Bian, Jianchun; Liu, ZongPing
The aim of this study was to investigate the molecular mechanisms of the destruction of cytoskeletal structure by Zearalenone (ZEA) in mouse-derived TM4 cells. In order to investigate the role of autophagy, oxidative stress and endoplasmic reticulum(ER) stress in the process of destruction of cytoskeletal structure, the effects of ZEA on the cell viability, cytoskeletal structure, autophagy, oxidative stress, ER stress, MAPK and PI3K- AKT- mTOR signaling pathways were studied. The data demonstrated that ZEA damaged the cytoskeletal structure through the induction of autophagy that leads to the alteration of cytoskeletal structure via elevated oxidative stress. Our results further showed that the autophagy was stimulated by ZEA through PI3K-AKT-mTOR and MAPK signaling pathways in TM4 cells. In addition, ZEA also induced the ER stress which was involved in the induction of the autophagy through inhibiting the ERK signal pathway to suppress the phosphorylation of mTOR. ER stress was involved in the damage of cytoskeletal structure through induction of autophagy by producing ROS. Taken together, this study revealed that ZEA altered the cytoskeletal structure via oxidative stress - autophagy- ER stress pathway in mouse TM4 Sertoli cells.
Khan, Ahmad Raza; Kroenke, Christopher D; Wiborg, Ove
Chronic mild stress leads to depression in many cases and is linked to several debilitating diseases including mental disorders. Recently, neuronal tracing techniques, stereology, and immunohistochemistry have revealed persistent and significant microstructural alterations in the hippocampus......, hypothalamus, prefrontal cortex, and amygdala, which form an interconnected system known as the stress circuit. Most studies have focused only on this circuit, however, some studies indicate that manipulation of sensory and motor systems may impact genesis and therapy of mood disorders and therefore...... these areas should not be neglected in the study of brain microstructure alterations in response to stress and depression. For this reason, we explore the microstructural alterations in different cortical regions in a chronic mild stress model of depression. The study employs ex-vivo diffusion MRI (d...
Kwok Yeung Tsang
Full Text Available In protein folding and secretion disorders, activation of endoplasmic reticulum (ER stress signaling (ERSS protects cells, alleviating stress that would otherwise trigger apoptosis. Whether the stress-surviving cells resume normal function is not known. We studied the in vivo impact of ER stress in terminally differentiating hypertrophic chondrocytes (HCs during endochondral bone formation. In transgenic mice expressing mutant collagen X as a consequence of a 13-base pair deletion in Col10a1 (13del, misfolded alpha1(X chains accumulate in HCs and elicit ERSS. Histological and gene expression analyses showed that these chondrocytes survived ER stress, but terminal differentiation is interrupted, and endochondral bone formation is delayed, producing a chondrodysplasia phenotype. This altered differentiation involves cell-cycle re-entry, the re-expression of genes characteristic of a prehypertrophic-like state, and is cell-autonomous. Concomitantly, expression of Col10a1 and 13del mRNAs are reduced, and ER stress is alleviated. ERSS, abnormal chondrocyte differentiation, and altered growth plate architecture also occur in mice expressing mutant collagen II and aggrecan. Alteration of the differentiation program in chondrocytes expressing unfolded or misfolded proteins may be part of an adaptive response that facilitates survival and recovery from the ensuing ER stress. However, the altered differentiation disrupts the highly coordinated events of endochondral ossification culminating in chondrodysplasia.
Kaess, Michael; Parzer, Peter; Koenig, Julian; Resch, Franz; Brunner, Romuald
Research to elucidate early alterations of higher cognitive processes in adolescents with BPD is rare. This study investigated differences in dual-task performance in adolescents with BPD during stress and non-stress conditions. The study sample comprised 30 female adolescents with BPD and 34 healthy controls. The impact of stress on dual-task performance was measured using a standardized stressor. Self-reports of distress and measures of heart rate (HR) were obtained to measure stress reactivity. There were no group differences in task performance. Under stress conditions, the performance on the auditory task decreased in both groups but without significant group differences. Healthy controls showed an increase of mean HR after stress induction compared to no change in the BPD group. The finding of attenuated HR response to acute stress in adolescent patients with BPD may contradict current theories that the affective hyperresponsivity in BPD is based on a biologically determined mechanism.
Hammond, Max A; Wallace, Joseph M; Allen, Matthew R; Siegmund, Thomas
Trabecular bone is composed of organized mineralized collagen fibrils, which results in heterogeneous and anisotropic mechanical properties at the tissue level. Recently, biomechanical models computing stresses and strains in trabecular bone have indicated a significant effect of tissue heterogeneity on predicted stresses and strains. However, the effect of the tissue-level mechanical anisotropy on the trabecular bone biomechanical response is unknown. Here, a computational method was established to automatically impose physiologically relevant orientation inherent in trabecular bone tissue on a trabecular bone microscale finite element model. Spatially varying tissue-level anisotropic elastic properties were then applied according to the bone mineral density and the local tissue orientation. The model was used to test the hypothesis that anisotropy in both homogeneous and heterogeneous models alters the predicted distribution of stress invariants. Linear elastic finite element computations were performed on a 3 mm cube model isolated from a microcomputed tomography scan of human trabecular bone from the distal femur. Hydrostatic stress and von Mises equivalent stress were recorded at every element, and the distributions of these values were analyzed. Anisotropy reduced the range of hydrostatic stress in both tension and compression more strongly than the associated increase in von Mises equivalent stress. The effect of anisotropy was independent of the spatial redistribution high compressive stresses due to tissue elastic heterogeneity. Tissue anisotropy and heterogeneity are likely important mechanisms to protect bone from failure and should be included for stress analyses in trabecular bone.
Kosová, Klára; Vítámvás, Pavel; Urban, Milan O.; Prášil, Ilja T.; Renaut, Jenny
HIGHLIGHTS: Major environmental and genetic factors determining stress-related protein abundance are discussed.Major aspects of protein biological function including protein isoforms and PTMs, cellular localization and protein interactions are discussed.Functional diversity of protein isoforms and PTMs is discussed. Abiotic stresses reveal profound impacts on plant proteomes including alterations in protein relative abundance, cellular localization, post-transcriptional and post-translational modifications (PTMs), protein interactions with other protein partners, and, finally, protein biological functions. The main aim of the present review is to discuss the major factors determining stress-related protein accumulation and their final biological functions. A dynamics of stress response including stress acclimation to altered ambient conditions and recovery after the stress treatment is discussed. The results of proteomic studies aimed at a comparison of stress response in plant genotypes differing in stress adaptability reveal constitutively enhanced levels of several stress-related proteins (protective proteins, chaperones, ROS scavenging- and detoxification-related enzymes) in the tolerant genotypes with respect to the susceptible ones. Tolerant genotypes can efficiently adjust energy metabolism to enhanced needs during stress acclimation. Stress tolerance vs. stress susceptibility are relative terms which can reflect different stress-coping strategies depending on the given stress treatment. The role of differential protein isoforms and PTMs with respect to their biological functions in different physiological constraints (cellular compartments and interacting partners) is discussed. The importance of protein functional studies following high-throughput proteome analyses is presented in a broader context of plant biology. In summary, the manuscript tries to provide an overview of the major factors which have to be considered when interpreting data from proteomic
Lu, Huijie; Ulanov, Alexander V; Nobu, Masaru; Liu, Wen-Tso
The model ammonia-oxidizing bacterium Nitrosomonas europaea represents one of the environmentally and biotechnologically significant microorganisms. Genome-based studies over the last decade have led to many intriguing discoveries about its cellular biochemistry and physiology. However, knowledge regarding the regulation of overall metabolic routes in response to various environmental stresses is limited due to a lack of comprehensive, time-resolved metabolomic analyses. In this study, gas chromatography-mass spectrometry (GC-MS)-based metabolic profiling was performed to characterize the temporal variations of N. europaea 19718 intercellular metabolites in response to varied temperature (23 and 10 °C) and ammonia feeding patterns (shock loading and continuous feeding of 20 mg N/L). Approximately 87 metabolites were successfully identified and mapped to the existing pathways of N. europaea 19718, allowing interpretation of the influence of temperature and feeding pattern on metabolite levels. In general, varied temperature had a more profound influence on the overall metabolism than varied feeding patterns. Total extracellular metabolite concentrations (relative to internal standards and normalized to biomass weight) were lower under cold stress and shock loading conditions compared with the control (continuous feeding at 23 °C). Cold stress caused the widespread downregulation of metabolites involved in central carbon metabolism, amino acid, and lipid synthesis (e.g., malonic acid, succinic acid, putrescine, and phosphonolpyruvate). Metabolites that showed differences under varied feeding patterns were mainly involved in nucleotide acid, amino acid, and lipid metabolism (e.g., adenine, uracil, and spermidine). This study highlighted the roles of central carbon and nitrogen metabolism in countering cold stress and altered ammonia availability. In addition, transcriptomic, proteomic, and metabolomic data from three studies on N. europaea were compared to achieve a
© 2015 Springer-Verlag Berlin Heidelberg The model ammonia-oxidizing bacterium Nitrosomonas europaea represents one of the environmentally and biotechnologically significant microorganisms. Genome-based studies over the last decade have led to many intriguing discoveries about its cellular biochemistry and physiology. However, knowledge regarding the regulation of overall metabolic routes in response to various environmental stresses is limited due to a lack of comprehensive, time-resolved metabolomic analyses. In this study, gas chromatography–mass spectrometry (GC-MS)-based metabolic profiling was performed to characterize the temporal variations of N. europaea 19718 intercellular metabolites in response to varied temperature (23 and 10 °C) and ammonia feeding patterns (shock loading and continuous feeding of 20 mg N/L). Approximately 87 metabolites were successfully identified and mapped to the existing pathways of N. europaea 19718, allowing interpretation of the influence of temperature and feeding pattern on metabolite levels. In general, varied temperature had a more profound influence on the overall metabolism than varied feeding patterns. Total extracellular metabolite concentrations (relative to internal standards and normalized to biomass weight) were lower under cold stress and shock loading conditions compared with the control (continuous feeding at 23 °C). Cold stress caused the widespread downregulation of metabolites involved in central carbon metabolism, amino acid, and lipid synthesis (e.g., malonic acid, succinic acid, putrescine, and phosphonolpyruvate). Metabolites that showed differences under varied feeding patterns were mainly involved in nucleotide acid, amino acid, and lipid metabolism (e.g., adenine, uracil, and spermidine). This study highlighted the roles of central carbon and nitrogen metabolism in countering cold stress and altered ammonia availability. In addition, transcriptomic, proteomic, and metabolomic data from three
Al-Lawati, A; Al-Bahry, S; Victor, R; Al-Lawati, A H; Yaish, M W
Modification of DNA methylation status is one of the mechanisms used by plants to adjust gene expression at both the transcriptional and posttranscriptional levels when plants are exposed to suboptimal conditions. Under abiotic stress, different cultivars often show heritable phenotypic variation accompanied by epigenetic polymorphisms at the DNA methylation level. This variation may provide the raw materials for plant breeding programs that aim to enhance abiotic stress tolerance, including salt tolerance. In this study, methylation-sensitive amplified polymorphism (MSAP) analysis was used to assess cytosine methylation levels in alfalfa (Medicago spp) roots exposed to increasing NaCl concentrations (0.0, 8.0, 12.0, and 20.0 dS/m). Eleven indigenous landraces were analyzed, in addition to a salt-tolerant cultivar that was used as a control. There was a slight increase in DNA methylation upon exposure to high levels of soil salinity. Phylogenetic analysis using MSAP showed epigenetic variation within and between the alfalfa landraces when exposed to saline conditions. Based on MSAP and enzyme-linked immunosorbent assay results, we found that salinity increased global DNA methylation status, particularly in plants exposed to the highest level of salinity (20 dS/m). Quantitative reverse transcription-polymerase chain reaction indicated that this might be mediated by the overexpression of methyltransferase homolog genes after exposure to saline conditions. DNA demethylation using 5-azacytidine reduced seedling lengths and dry and fresh weights, indicating a possible decrease in salinity tolerance. These results suggest that salinity affects DNA methylation flexibility.
Ana S Vallés
Full Text Available Spermatogenesis is known to be vulnerable to temperature. Exposures of rat testis to moderate hyperthermia result in loss of germ cells with survival of Sertoli cells (SC. Because SC provide structural and metabolic support to germ cells, our aim was to test the hypothesis that these exposures affect SC functions, thus contributing to germ cell damage. In vivo, regularly repeated exposures (one of 15 min per day, once a day during 5 days of rat testes to 43 °C led to accumulation of neutral lipids. This SC-specific lipid function took 1-2 weeks after the last of these exposures to be maximal. In cultured SC, similar daily exposures for 15 min to 43 °C resulted in significant increase in triacylglycerol levels and accumulation of lipid droplets. After incubations with [3H]arachidonate, the labeling of cardiolipin decreased more than that of other lipid classes. Another specifically mitochondrial lipid metabolic function, fatty acid oxidation, also declined. These lipid changes suggested that temperature affects SC mitochondrial physiology, which was confirmed by significantly increased degrees of membrane depolarization and ROS production. This concurred with reduced expression of two SC-specific proteins, transferrin, and Wilms' Tumor 1 protein, markers of SC secretion and differentiation functions, respectively, and with an intense SC cytoskeletal perturbation, evident by loss of microtubule network (α-tubulin and microfilament (f-actin organization. Albeit temporary and potentially reversible, hyperthermia-induced SC structural and metabolic alterations may be long-lasting and/or extensive enough to respond for the decreased survival of the germ cells they normally foster.
Rioboo, Carmen; O'Connor, Jose Enrique; Prado, Raquel; Herrero, Concepcion; Cid, Angeles
Very little is known about growth and proliferation in relation to the cell cycle regulation of algae. The lack of knowledge is even greater when referring to the potential toxic effects of pollutants on microalgal cell division. To assess the effect of terbutryn, a triazine herbicide, on the proliferation of the freshwater microalga Chlorella vulgaris three flow cytometric approaches were used: (1) in vivo cell division using 5-,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) staining was measured, (2) the growth kinetics were determined by cytometric cell counting and (3) cell viability was evaluated with the membrane-impermeable double-stranded nucleic acid stain propidium iodide (PI). The results obtained in the growth kinetics study using CFSE to identify the microalgal cell progeny were consistent with those determined by cytometric cell counting. In all C. vulgaris cultures, each mother cell had undergone only one round of division through the 96 h of assay and the cell division occurred during the dark period. Cell division of the cultures exposed to the herbicide was asynchronous. Terbutryn altered the normal number of daughter cells (4 autospores) obtained from each mother cell. The number was only two in the cultures treated with 250 nM. The duration of the lag phase after the exposure to terbutryn could be dependent on the existence of a critical cell size to activate cytoplasmic division. Cell size, complexity and fluorescence of chlorophyll a of the microalgal cells presented a marked light/dark (day/night) cycle, except in the non-dividing 500 nM cultures, where terbutryn arrested cell division at the beginning of the cycle. Viability results showed that terbutryn has an algastatic effect in C. vulgaris cells at this concentration. The rapid and precise determination of cell proliferation by CFSE staining has allowed us to develop a model for assessing both the cell cycle of C. vulgaris and the in vivo effects of pollutants on growth and
Rioboo, Carmen [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n, 15008 A Coruna (Spain); O' Connor, Jose Enrique [Laboratorio de Citomica, Unidad Mixta de Investigacion CIPF-UVEG, Centro de Investigacion Principe Felipe, Avda. Autopista del Saler, 16, 46013 Valencia (Spain); Prado, Raquel; Herrero, Concepcion [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n, 15008 A Coruna (Spain); Cid, Angeles, E-mail: firstname.lastname@example.org [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n, 15008 A Coruna (Spain)
Very little is known about growth and proliferation in relation to the cell cycle regulation of algae. The lack of knowledge is even greater when referring to the potential toxic effects of pollutants on microalgal cell division. To assess the effect of terbutryn, a triazine herbicide, on the proliferation of the freshwater microalga Chlorella vulgaris three flow cytometric approaches were used: (1) in vivo cell division using 5-,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) staining was measured, (2) the growth kinetics were determined by cytometric cell counting and (3) cell viability was evaluated with the membrane-impermeable double-stranded nucleic acid stain propidium iodide (PI). The results obtained in the growth kinetics study using CFSE to identify the microalgal cell progeny were consistent with those determined by cytometric cell counting. In all C. vulgaris cultures, each mother cell had undergone only one round of division through the 96 h of assay and the cell division occurred during the dark period. Cell division of the cultures exposed to the herbicide was asynchronous. Terbutryn altered the normal number of daughter cells (4 autospores) obtained from each mother cell. The number was only two in the cultures treated with 250 nM. The duration of the lag phase after the exposure to terbutryn could be dependent on the existence of a critical cell size to activate cytoplasmic division. Cell size, complexity and fluorescence of chlorophyll a of the microalgal cells presented a marked light/dark (day/night) cycle, except in the non-dividing 500 nM cultures, where terbutryn arrested cell division at the beginning of the cycle. Viability results showed that terbutryn has an algastatic effect in C. vulgaris cells at this concentration. The rapid and precise determination of cell proliferation by CFSE staining has allowed us to develop a model for assessing both the cell cycle of C. vulgaris and the in vivo effects of pollutants on growth and
Adolescents experience stressful situations at a high rate during school. Indeed, school is the most common source of stress for teens. This high rate of stress may promote increases in adiposity during a developmental period important for establishing the adult physique. Adiposity gains may be th...
C, Jadiswami; H M, Megha; Dhadde, Shivsharan B; Durg, Sharanbasappa; Potadar, Pandharinath P; B S, Thippeswamy; V P, Veerapur
3-Nitropropionic acid (3-NP) is a fungal toxin that produces Huntington's disease like symptoms in both animals and humans. Piroxicam, a non-selective cyclooxygenase (COX) inhibitor, used as anti-inflammatory agent and also known to decrease free oxygen radical production. In this study, the effect of piroxicam was evaluated against 3-NP-induced brain oxidative stress and behavioral alteration in mice. Adult male Swiss albino mice were injected with vehicle/piroxicam (10 and 20 mg/kg, i.p.) 30 min before 3-NP challenge (15 mg/kg, i.p.) regularly for 14 days. Body weights of the mice were measured on alternative days of the experiment. At the end of the treatment schedule, mice were evaluated for behavioral alterations (movement analysis, locomotor test, beam walking test and hanging wire test) and brain homogenates were used for the estimation of oxidative stress markers (lipid peroxidation, reduced glutathione and catalase). Administration of 3-NP significantly altered the behavioral activities and brain antioxidant status in mice. Piroxicam, at both the tested doses, caused a significant reversal of 3-NP-induced behavioral alterations and oxidative stress in mice. These findings suggest piroxicam protects the mice against 3-NP-induced brain oxidative stress and behavioral alteration. The antioxidant properties of piroxicam may be responsible for the observed beneficial actions.
Doege, H. (Bezirkskrankenhaus ' Friedrich Wolf' , Abt. fuer Nuklearmedizin, Chemnitz (Germany))
This report describes our experiences with the bone imaging in athletes. We studied 10 athletes and 10 other patients with spondylolisthesis of the lumbar spine and 16 athletes with suspicion of alterations of extremities. An increased uptake of this radiopharmaceutical was detected in six of 10 athletes with spondylolisthesis caused probably by stress fracture. Bone scans were negative in seven of 16 athletes with suspicion of lesion of extremities. In the remaining 9 patients scans were abnormal and showed periosteal injuries, epiphyseal alteration, joint abnormalities, tibial stress fractures and couvert fracture. It was also abnormal in bone injuries not evident in radiography. (orig.).
Dehghan; Mobinyzadeh; Habibi
Background Job satisfaction, job performance, job stress and heat stress affect the productivity of workers. Objectives This research aimed to study the relationship between heat stress indices with job satisfaction, job performance and job stress in casting workers. Patients and Methods This descriptive-analytical cross sectional survey was performed during summer 2013 on one hund...
Suzuki, Ayumi; Iinuma, Mitsuo; Hayashi, Sakurako; Sato, Yuichi; Azuma, Kagaku; Kubo, Kin-Ya
Maternal chewing during prenatal stress attenuates both the development of stress-induced learning deficits and decreased cell proliferation in mouse hippocampal dentate gyrus. Hippocampal myelination affects spatial memory and the synaptic structure is a key mediator of neuronal communication. We investigated whether maternal chewing during prenatal stress ameliorates stress-induced alterations of hippocampal myelin and synapses, and impaired development of spatial memory in adult offspring. Pregnant mice were divided into control, stress, and stress/chewing groups. Stress was induced by placing mice in a ventilated restraint tube, and was initiated on day 12 of pregnancy and continued until delivery. Mice in the stress/chewing group were given a wooden stick to chew during restraint. In 1-month-old pups, spatial memory was assessed in the Morris water maze, and hippocampal oligodendrocytes and synapses in CA1 were assayed by immunohistochemistry and electron microscopy. Prenatal stress led to impaired learning ability, and decreased immunoreactivity of myelin basic protein (MBP) and 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) in the hippocampal CA1 in adult offspring. Numerous myelin sheath abnormalities were observed. The G-ratio [axonal diameter to axonal fiber diameter (axon plus myelin sheath)] was increased and postsynaptic density length was decreased in the hippocampal CA1 region. Maternal chewing during stress attenuated the prenatal stress-induced impairment of spatial memory, and the decreased MBP and CNPase immunoreactivity, increased G-ratios, and decreased postsynaptic-density length in the hippocampal CA1 region. These findings suggest that chewing during prenatal stress in dams could be an effective coping strategy to prevent hippocampal behavioral and morphologic impairments in their offspring. Copyright © 2016 Elsevier B.V. All rights reserved.
Full Text Available We addressed if oxidative stress in the renal cortex plays a role in the induction of hypertension and mitochondrial alterations in hyperuricemia. A second objective was to evaluate whether the long-term treatment with the antioxidant Tempol prevents renal oxidative stress, mitochondrial alterations, and systemic hypertension in this model. Long-term (11-12 weeks and short-term (3 weeks effects of oxonic acid induced hyperuricemia were studied in rats (OA, 750 mg/kg BW, OA+Allopurinol (AP, 150 mg/L drinking water, OA+Tempol (T, 15 mg/kg BW, or vehicle. Systolic blood pressure, renal blood flow, and vascular resistance were measured. Tubular damage (urine N-acetyl-β-D-glucosaminidase and oxidative stress markers (lipid and protein oxidation along with ATP levels were determined in kidney tissue. Oxygen consumption, aconitase activity, and uric acid were evaluated in isolated mitochondria from renal cortex. Short-term hyperuricemia resulted in hypertension without demonstrable renal oxidative stress or mitochondrial dysfunction. Long-term hyperuricemia induced hypertension, renal vasoconstriction, tubular damage, renal cortex oxidative stress, and mitochondrial dysfunction and decreased ATP levels. Treatments with Tempol and allopurinol prevented these alterations. Renal oxidative stress induced by hyperuricemia promoted mitochondrial functional disturbances and decreased ATP content, which represent an additional pathogenic mechanism induced by chronic hyperuricemia. Hyperuricemia-related hypertension occurs before these changes are evident.
Rowlett, Veronica W; Mallampalli, Venkata K P S; Karlstaedt, Anja; Dowhan, William; Taegtmeyer, Heinrich; Margolin, William; Vitrac, Heidi
Bacteria have evolved multiple strategies to sense and rapidly adapt to challenging and ever-changing environmental conditions. The ability to alter membrane lipid composition, a key component of the cellular envelope, is crucial for bacterial survival and adaptation in response to environmental stress. However, the precise roles played by membrane phospholipids in bacterial physiology and stress adaptation are not fully elucidated. The goal of this study was to define the role of membrane phospholipids in adaptation to stress and maintenance of bacterial cell fitness. By using genetically modified strains in which the membrane phospholipid composition can be systematically manipulated, we show that alterations in major Escherichia coli phospholipids transform these cells globally. We found that alterations in phospholipids impair the cellular envelope structure and function, the ability to form biofilms, and bacterial fitness and cause phospholipid-dependent susceptibility to environmental stresses. This study provides an unprecedented view of the structural, signaling, and metabolic pathways in which bacterial phospholipids participate, allowing the design of new approaches in the investigation of lipid-dependent processes involved in bacterial physiology and adaptation. IMPORTANCE In order to cope with and adapt to a wide range of environmental conditions, bacteria have to sense and quickly respond to fluctuating conditions. In this study, we investigated the effects of systematic and controlled alterations in bacterial phospholipids on cell shape, physiology, and stress adaptation. We provide new evidence that alterations of specific phospholipids in Escherichia coli have detrimental effects on cellular shape, envelope integrity, and cell physiology that impair biofilm formation, cellular envelope remodeling, and adaptability to environmental stresses. These findings hold promise for future antibacterial therapies that target bacterial lipid biosynthesis
Sinha, Rajita; Fox, Helen C; Hong, Kwangik A; Bergquist, Keri; Bhagwagar, Zubin; Siedlarz, Kristen M
Chronic alcohol abuse is associated with changes in stress and reward pathways that could alter vulnerability to emotional stress and alcohol craving. This study examines whether chronic alcohol abuse is associated with altered stress and alcohol craving responses. Treatment-engaged, 28-day abstinent alcohol-dependent individuals (ADs; 6F/22M), and social drinkers (SDs; 10F/18M) were exposed to a brief guided imagery of a personalized stressful, alcohol-related and neutral-relaxing situation,...
of the cellular elements normally present in peripheral nerve . 2. KEYWORDS: peripheral nerve repair , nerve injury , decellularized nerve ... nerve regeneration. The slow rate of nerve re generation in limbs results in poor prognosis for patients suffering from severe injuries , leading to...allograft, neural regeneration, stem cells, stress altered cells, peripheral nerve injury model, nerve graft 3 This comprehensive final report summarizes
Stengel, Andreas; Wang, Lixin; Taché, Yvette
Ghrelin is the only known peripherally produced and centrally acting peptide hormone that stimulates food intake and digestive functions. Ghrelin circulates as acylated and desacylated forms and recently the acylating enzyme, ghrelin-O-acyltransferase (GOAT) and the de-acylating enzyme, thioesterase 1/lysophospholipase 1 have been identified adding new layers of complexity to the regulation of ghrelin. Stress is known to alter gastrointestinal motility and food intake and was recently shown to modify circulating ghrelin and GOAT levels with differential responses related to the type of stressors including a reduction induced by physical stressors (abdominal surgery and immunological/endotoxin injection, exercise) and elevation by metabolic (cold exposure, fasting and caloric restriction) and psychological stressors. However, the pathways underlying the alterations of ghrelin under these various stress conditions are still largely to be defined and may relate to stress-associated autonomic changes. There is evidence that alterations of circulating ghrelin may contribute to the neuroendocrine and behavioral responses along with sustaining the energetic requirement needed upon repeated exposure to stressors. A better understanding of these mechanisms will allow targeting components of ghrelin signaling that may improve food intake and gastric motility alterations induced by stress. PMID:21782868
Meyer, Edward M; Long, Virginia; Fanselow, Michael S; Spigelman, Igor
Life-altering anxiety disorders, such as posttraumatic stress disorder (PTSD), can co-occur at high rates with substance use disorders. Alcoholism, compared with other substance use disorders, is particularly common. Rodent studies of acute stress effects on alcohol consumption show that stress can alter ethanol (EtOH) consumption. This study examined voluntary EtOH consumption in male Long-Evans rats that had undergone a stress-enhanced fear learning (SEFL) procedure. Adult Long-Evans rats were exposed to a stress that consisted of 15 inescapable foot-shocks (1 mA, 1 second) known to cause a long-lasting nonassociative enhancement of subsequent fear learning. Control animals received no shock. One day later, animals were placed in a novel and very different context and received a single foot-shock. On day 3, animals were returned to the single shock context and freezing was used as a measure of learned fear. The intermittent access 2-bottle choice (2BC) regimen consisted of 1 bottle of water and 1 bottle of experimental solution, either 19% EtOH or 28.4% sucrose-0.08% quinine, for a 24-hour period, 3 days a week, and all other times 2 water bottles. This regimen lasted until stable levels of experimental solution drinking were reached, at which point the experimental solution was removed for 40 days and then returned to measure the resumption of consumption. Rats that received stress prior to EtOH consumed significantly more EtOH than control rats before and after reinstatement. Rats that received stress after drinking was established did not consume significantly more EtOH when the drug was returned. Stress had no significant effect on sucrose-quinine drinking, our calorie and taste control for EtOH. A single traumatic event sufficient to produce long-lasting enhancement of fear learning increases voluntary EtOH consumption, but does not alter previously acquired EtOH drinking habits or alter the consumption of a calorically equivalent sweet
Key words: Music, Music Performance, Music Therapy, and Stress Management. Introduction. Life is full .... the challenges facing the use of music performance as therapy for stress management should be surmounted ..... hindrances to both male and female lecturers for the management of stress using music performances ...
Světlák, M; Bob, P; Roman, R; Ježek, S; Damborská, A; Chládek, J; Shaw, D J; Kukleta, M
In this study, we tested the hypothesis that experimental stress induces a specific change of left-right electrodermal activity (EDA) coupling pattern, as indexed by pointwise transinformation (PTI). Further, we hypothesized that this change is associated with scores on psychometric measures of the chronic stress-related psychopathology. Ninety-nine university students underwent bilateral measurement of EDA during rest and stress-inducing Stroop test and completed a battery of self-report measures of chronic stress-related psychopathology. A significant decrease in the mean PTI value was the prevalent response to the stress conditions. No association between chronic stress and PTI was found. Raw scores of psychometric measures of stress-related psychopathology had no effect on either the resting levels of PTI or the amount of stress-induced PTI change. In summary, acute stress alters the level of coupling pattern of cortico-autonomic influences on the left and right sympathetic pathways to the palmar sweat glands. Different results obtained using the PTI, EDA laterality coefficient, and skin conductance level also show that the PTI algorithm represents a new analytical approach to EDA asymmetry description.
Golubeva, Anna V; Crampton, Sean; Desbonnet, Lieve; Edge, Deirdre; O'Sullivan, Orla; Lomasney, Kevin W; Zhdanov, Alexander V; Crispie, Fiona; Moloney, Rachel D; Borre, Yuliya E; Cotter, Paul D; Hyland, Niall P; O'Halloran, Ken D; Dinan, Timothy G; O'Keeffe, Gerard W; Cryan, John F
Early-life adverse experiences, including prenatal stress (PNS), are associated with a higher prevalence of neurodevelopmental, cardiovascular and metabolic disorders in affected offspring. Here, in a rat model of chronic PNS, we investigate the impact of late gestational stress on physiological outcomes in adulthood. Sprague-Dawley pregnant dams were subjected to repeated restraint stress from embryonic day 14 to day 20, and their male offspring were assessed at 4 months of age. PNS induced an exaggeration of the hypothalamic-pituitary-adrenal (HPA) axis response to stress, as well as an elevation of blood pressure and impairment of cognitive function. Altered respiratory control was also observed, as demonstrated by increased variability in basal respiratory frequency and abnormal frequency responses to both hypoxic and hypercapnic challenges. PNS also affected gastrointestinal neurodevelopment and function, as measured by a decrease in the innervation density of distal colon and an increase in the colonic secretory response to catecholaminergic stimulation. Finally, PNS induced long lasting alterations in the intestinal microbiota composition. 16S rRNA gene 454 pyrosequencing revealed a strong trend towards decreased numbers of bacteria in the Lactobacillus genus, accompanied by elevated abundance of the Oscillibacter, Anaerotruncus and Peptococcus genera in PNS animals. Strikingly, relative abundance of distinct bacteria genera significantly correlated with certain respiratory parameters and the responsiveness of the HPA axis to stress. Together, these findings provide novel evidence that PNS induces long-term maladaptive alterations in the gastrointestinal and respiratory systems, accompanied by hyper-responsiveness to stress and alterations in the gut microbiota. Copyright © 2015 Elsevier Ltd. All rights reserved.
Full Text Available BACKGROUND: Human activity has a profound effect on the global environment and caused frequent occurrence of climatic fluctuations. To survive, plants need to adapt to the changing environmental conditions through altering their morphological and physiological traits. One known mechanism for phenotypic innovation to be achieved is environment-induced rapid yet inheritable epigenetic changes. Therefore, the use of molecular techniques to address the epigenetic mechanisms underpinning stress adaptation in plants is an important and challenging topic in biological research. In this study, we investigated the impact of warming, nitrogen (N addition, and warming+nitrogen (N addition stresses on the cytosine methylation status of Leymus chinensis Tzvel. at the population level by using the amplified fragment length polymorphism (AFLP, methylation-sensitive amplified polymorphism (MSAP and retrotransposon based sequence-specific amplification polymorphism (SSAP techniques. METHODOLOGY/PRINCIPAL FINDINGS: Our results showed that, although the percentages of cytosine methylation changes in SSAP are significantly higher than those in MSAP, all the treatment groups showed similar alteration patterns of hypermethylation and hypomethylation. It meant that the abiotic stresses have induced the alterations in cytosine methylation patterns, and the levels of cytosine methylation changes around the transposable element are higher than the other genomic regions. In addition, the identification and analysis of differentially methylated loci (DML indicated that the abiotic stresses have also caused targeted methylation changes at specific loci and these DML might have contributed to the capability of plants in adaptation to the abiotic stresses. CONCLUSIONS/SIGNIFICANCE: Our results demonstrated that abiotic stresses related to global warming and nitrogen deposition readily evoke alterations of cytosine methylation, and which may provide a molecular basis for rapid
Linn, Bernard S.; Zeppa, Robert
A study of student stress before and after a clinical clerkship examined the relationship of favorable or unfavorable stress, as perceived by the student, to locus of control and self-esteem. The major finding was an association of unfavorable stress with poor academic performance. Stress management training is recommended. (MSE)
Stasytyte-Buneviciene, D.; Juozulynas, A.; Bunevicius, J.
Intensified formation of free radicals is one of the most important harmful factors of ionizing radiation acting upon human organism. Under physiological conditions, anti oxidative system preserves from harmful influence of free radicals. To avoid a disturbing influence of oxidative stress upon the processes of human homeostasis, additional quantities of antioxidants are indispensable. Among native biomodulators, pollen are well known for their anti oxidative, antitoxic and radioprotective properties. Dynamics of alterations of markers of oxidative stress as well as possibilities of restitution of their qualitative and quantitative indices were studied using native pollen. Correction programme was performed on 50 persons, 9 males and 41 female, residing and working under impact of harmful factors of oxidative stress, who used pollen 10 g per day during a period of 30 days. Control group consisted of 57 persons, 10 males and 47 females living and working under the same conditions. Blood tests (diene conjugates, malonic dialdehyde and katalase) using standard spectrophotometric methodic were studied before and after the course of treatment. After the treatment, contents of metabolites of lipid peroxidation, diene conjugates and malonic dialdehyde in blood serum essentially reduced. Activity of catalase decreased significantly in blood serum of the males and regularly smoking females. In conclusion, data presented demonstrate anti oxidative efficiency of native pollen and suggest more often it's applying in cases with alterated processes of homeostasis under impact of harmful factors of oxidative stress including influence of ionizing radiation. (author)
Remus, Jennifer L.; Stewart, Luke T.; Camp, Robert M.; Novak, Colleen M.; Johnson, John D.
There is growing evidence that metabolic stressors increase an organism’s risk of depression. Chronic mild stress is a popular animal model of depression and several serendipitous findings have suggested that food deprivation prior to sucrose testing in this model is necessary to observe anhedonic behaviors. Here, we directly tested this hypothesis by exposing animals to chronic mild stress and used an overnight two bottle sucrose test (food ad libitum) on day 5 and 10, then food and water de...
Chatterjee, O; Taylor, L A; Ahmed, S; Nagaraj, S; Hall, J J; Finckbeiner, S M; Chan, P S; Suda, N; King, J T; Zeeman, M L; McCobb, D P
Large conductance calcium-activated potassium (BK) channels are very prominently expressed in adrenal chromaffin and many anterior pituitary cells, where they shape intrinsic excitability complexly. Stress- and sex-steroids regulate alternative splicing of Slo-alpha, the pore-forming subunit of BK channels, and chronic behavioural stress has been shown to alter Slo splicing in tree shrew adrenals. In the present study, we focus on mice, measuring the effects of chronic behavioural stress on total mRNA expression of the Slo-alpha gene, two key BK channel beta subunit genes (beta2 and beta4), and the 'STREX' splice variant of Slo-alpha. As a chronic stressor, males of the relatively aggressive SJL strain were housed with a different unfamiliar SJL male every 24 h for 19 days. This 'social-instability' paradigm stressed all individuals, as demonstrated by reduced weight gain and elevated corticosterone levels. Five quantitative reverse transcriptase-polymerase chain assays were performed in parallel, including beta-actin, each calibrated against a dilution series of its corresponding cDNA template. Stress-related changes in BK expression were larger in mice tested at 6 weeks than 9 weeks. In younger animals, Slo-alpha mRNA levels were elevated 44% and 116% in the adrenal medulla and pituitary, respectively, compared to individually-housed controls. beta2 and beta4 mRNAs were elevated 162% and 194% in the pituitary, but slightly reduced in the adrenals of stressed animals. In the pituitary, dominance scores of stressed animals correlated negatively with alpha and beta subunit expression, with more subordinate individuals exhibiting levels that were three- to four-fold higher than controls or dominant individuals. STREX variant representation was lower in the subordinate subset. Thus, the combination of subunits responding to stress differs markedly between adrenal and pituitary glands. These data suggest that early stress will differentially affect neuroendocrine cell
Full Text Available In the brain, the heme oxygenase (HO system has been reported to be very active and its modulation seems to play a crucial role in the pathophysiology of neurodegenerative disorders. Hemin as HO-1 inducer has been shown to attenuate neuronal injury so the goal of this study was to assess the effect of hemin therapy on the acute stress and how it would modulate neurological outcome. Thirty male albino rats were divided into three groups: control group and stressed group with six-hour water immersion restraint stress (WIRS and stressed group, treated with hemin, in which each rat received a single intraperitoneal injection of hemin at a dose level of 50 mg/kg body weight at 12 hours before exposure to WIRS. Stress hormones, oxidative stress markers, malondialdehyde (MDA, and total antioxidant capacity (TAC were measured and expressions of neuroglobin and S100B mRNA in brain tissue were assayed. Our results revealed that hemin significantly affects brain alterations induced by acute stress and this may be through increased expression of neuroglobin and through antioxidant effect. Hemin decreased blood-brain barrier damage as it significantly decreased the expression of S100B. These results suggest that hemin may be an effective therapy for being neuroprotective against acute stress.
Taren, Adrienne A; Gianaros, Peter J; Greco, Carol M; Lindsay, Emily K; Fairgrieve, April; Brown, Kirk Warren; Rosen, Rhonda K; Ferris, Jennifer L; Julson, Erica; Marsland, Anna L; Bursley, James K; Ramsburg, Jared; Creswell, J David
Recent studies indicate that mindfulness meditation training interventions reduce stress and improve stress-related health outcomes, but the neural pathways for these effects are unknown. The present research evaluates whether mindfulness meditation training alters resting state functional connectivity (rsFC) of the amygdala, a region known to coordinate stress processing and physiological stress responses. We show in an initial discovery study that higher perceived stress over the past month is associated with greater bilateral amygdala-subgenual anterior cingulate cortex (sgACC) rsFC in a sample of community adults (n = 130). A follow-up, single-blind randomized controlled trial shows that a 3-day intensive mindfulness meditation training intervention (relative to a well-matched 3-day relaxation training intervention without a mindfulness component) reduced right amygdala-sgACC rsFC in a sample of stressed unemployed community adults (n = 35). Although stress may increase amygdala-sgACC rsFC, brief training in mindfulness meditation could reverse these effects. This work provides an initial indication that mindfulness meditation training promotes functional neuroplastic changes, suggesting an amygdala-sgACC pathway for stress reduction effects. © The Author (2015). Published by Oxford University Press. For Permissions, please email: email@example.com.
Julio-Pieper, Marcela; O'Mahony, Cliona M; Clarke, Gerard; Bravo, Javier A; Dinan, Timothy G; Cryan, John F
Mood disorders and chronic stress are frequently associated with gastrointestinal (GI) symptoms including diarrhoea or constipation. Locally produced serotonin [5-hydroxytryptamine (5-HT)] regulates GI motility and is a key factor in the pathophysiology of stress-associated GI disorders. We aimed to establish whether chronic stress can differentially affect faecal output and colon 5-HT concentration in two inbred mouse strains: BALB/c and C57BL/6 which differ in their ability to cope with stress. Adult male BALB/c and C57BL/6 mice were restrained for 2 h daily for 10 days. Defecation was monitored during each stress session. Twenty-four hours after the last session of stress, plasma corticosterone concentration was higher than control in both strains, indicative of a physiological effect of chronic stress; however, stress-induced diarrhoea was more persistent in C57BL/6 mice. Basal concentration of colon 5-HT was higher in C57BL/6 mice, and stress elicited an increase in colon 5-HT only in this strain. Finally, naïve BALB/c mice had a higher sensitivity (incidence of diarrhoea) to 5-HT (0.33 mg/kg, i.p.) than C57BL/6 mice. Our results suggest that differential defecation responses to stress may be associated with colon 5-HT concentration, which may in turn reflect the individual sensitivity to 5-HT. In addition, C57BL/6 mice emerge as a relevant model for studying GI alterations induced by chronic stress.
Maciążek-Jurczyk, M; Sułkowska, A; Równicka-Zubik, J
Changes of oxidative modified albumin conformation by comparison of non-modified (HSA) and modified (oHSA) human serum albumin absorption spectra, Red Edge Excitation Shift (REES) effect and fluorescence synchronous spectra were investigated. Studies of absorption spectra indicated that changes in the value of absorbance associated with spectral changes in the region from 200 to 250nm involve structural alterations related to variations in peptide backbone conformation. Analysis of the REES effect allowed for the observation of changes caused by oxidation in the region of the hydrophobic pocket containing the tryptophanyl residue. Synchronous fluorescence spectroscopy confirmed changes of the position of the tryptophanyl and tyrosil residues fluorescent band. Effect of oxidative stress on binding of methotrexate (MTX) was investigated by spectrofluorescence, UV-VIS and (1)HNMR spectroscopy. MTX caused the fluorescence quenching of non-modified (HSA) and modified (oHSA) human serum albumin molecule. The values of binding constants, Hill's coefficients and a number of binding sites in the protein molecule in the high affinity binding site were calculated for the binary MTX-HSA and MTX-oHSA systems. For these systems, qualitative analysis in the low affinity binding sites was performed with the use of the (1)HNMR technique. Copyright © 2015 Elsevier B.V. All rights reserved.
Smit, Christian; Rietkerk, Max; Wassen, Martin J.
The stress gradient hypothesis (SGH) predicts a shift from net negative interactions in benign environments towards net positive in harsh environments in ecological communities. While several studies found support for the SGH, others found evidence against it, leading to a debate on how nature and
Metz, G A; Schwab, M E; Welzl, H
Any behavioral testing induces stress to some degree. A meaningful interpretation of behavioral results can be difficult if stress, caused by handling or the testing situation, modifies the experimental outcome. Especially for neurological animal models, it is important to know how stress affects motor and sensory performance. Therefore, we investigated the effects of varying degrees of stress on several motor and sensory tasks that are frequently used to assess functional recovery after lesion-induced impairments in adult rats. Acute, subchronic, and chronic stress impaired ladder walking and prolonged the duration of grasping a bar. Stress also altered walking patterns by increasing the base of support and foot rotation and reducing stride length. Furthermore, chronic stress induced hypersensitivity to painful stimuli, but did not significantly influence the latency to remove sticky papers from the hindpaws (sticky paper test). In the light--dark (L/D) test, stress reduced the latency to enter the dark compartment and enhanced the number of transitions supporting that cold swim stress modifies the animal's level of anxiety. These data point towards a critical influence of acute or chronic stress on motor control and sensory performance of rats, suggesting that stress might be a critical intervening variable of the outcome of behavioral tests.
The prevalence of obesity in the United States continues to rise, increasing individual vulnerability to an array of adverse health outcomes. One factor that has been implicated causally in the increased accumulation of fat and excess food intake is the activity of the limbic-hypothalamic-pituitary-adrenal (LHPA) axis in the face of relentless stressor exposure. However, translational and clinical research continues to understudy the effects sex and gonadal hormones and LHPA axis dysfunction in the etiology of obesity even though women continue to be at greater risk than men for stress-induced disorders, including depression, emotional feeding and obesity. The current review will emphasize the need for sex-specific evaluation of the relationship between stress exposure and LHPA axis activity on individual risk for obesity by summarizing data generated by animal models currently being leveraged to determine the etiology of stress-induced alterations in feeding behavior and metabolism. There exists a clear lack of translational models that have been used to study female-specific risk. One translational model of psychosocial stress exposure that has proven fruitful in elucidating potential mechanisms by which females are at increased risk for stress-induced adverse health outcomes is that of social subordination in socially housed female macaque monkeys. Data from subordinate female monkeys suggest that increased risk for emotional eating and the development of obesity in females may be due to LHPA axis-induced changes in the behavioral and physiological sensitivity of estradiol. The lack in understanding of the mechanisms underlying these alterations necessitate the need to account for the effects of sex and gonadal hormones in the rationale, design, implementation, analysis and interpretation of results in our studies of stress axis function in obesity. Doing so may lead to the identification of novel therapeutic targets with which to combat stress-induced obesity
Kirschman, Lucas J; Crespi, Erica J; Warne, Robin W
Ubiquitous environmental stressors are often thought to alter animal susceptibility to pathogens and contribute to disease emergence. However, duration of exposure to a stressor is likely critical, because while chronic stress is often immunosuppressive, acute stress can temporarily enhance immune function. Furthermore, host susceptibility to stress and disease often varies with ontogeny; increasing during critical developmental windows. How the duration and timing of exposure to stressors interact to shape critical windows and influence disease processes is not well tested. We used ranavirus and larval amphibians as a model system to investigate how physiological stress and pathogenic infection shape development and disease dynamics in vertebrates. Based on a resource allocation model, we designed experiments to test how exposure to stressors may induce resource trade-offs that shape critical windows and disease processes because the neuroendocrine stress axis coordinates developmental remodelling, immune function and energy allocation in larval amphibians. We used wood frog larvae (Lithobates sylvaticus) to investigate how chronic and acute exposure to corticosterone, the dominant amphibian glucocorticoid hormone, mediates development and immune function via splenocyte immunohistochemistry analysis in association with ranavirus infection. Corticosterone treatments affected immune function, as both chronic and acute exposure suppressed splenocyte proliferation, although viral replication rate increased only in the chronic corticosterone treatment. Time to metamorphosis and survival depended on both corticosterone treatment and infection status. In the control and chronic corticosterone treatments, ranavirus infection decreased survival and delayed metamorphosis, although chronic corticosterone exposure accelerated rate of metamorphosis in uninfected larvae. Acute corticosterone exposure accelerated metamorphosis increased survival in infected larvae. Interactions
Stress, fatigue, and workload affect worker performance. NSF reported that 61% of respondents state losing concentration at work while 79% occasionally or frequently made errors as a result of being fatigued. Shift work, altered work schedules, long hours of continuous wakefulness, and sleep loss can create sleep and circadian disruptions that degrade waking fundions causing stress and fatigue. Review of the literature has proven void of information that links the combined effects of fatigue, stress, and workload to human performance. This paper will address which occupational factors within stress, fatigue, and workload were identified as occupational contributors to performance changes. The results of this research will be apglied to underlying models and algorithms that will help predict performance changes in control room operators.
Kawakami, Takashige, E-mail: firstname.lastname@example.org; Yoshimi, Masaki; Kadota, Yoshito; Inoue, Masahisa; Sato, Masao; Suzuki, Shinya
The role of endoplasmic reticulum (ER) stress in pregnancy remains largely unknown. Pregnant mice were subcutaneously administered tunicamycin (Tun), an ER stressor, as a single dose [0, 50, and 100 μg Tun/kg/body weight (BW)] on gestation days (GDs) 8.5, 12.5, and 15.5. A high incidence (75%) of preterm delivery was observed only in the group treated with Tun 100 μg/kg BW at GD 15.5, indicating that pregnant mice during late gestation are more susceptible to ER stress on preterm delivery. We further examined whether prolonged in utero exposure to ER stress affects fetal development. Pregnant mice were subcutaneously administered a dose of 0, 20, 40, and 60 μg Tun/kg from GD 12.5 to 16.5. Tun treatment decreased the placental and fetal weights in a dose-dependent manner. Histological evaluation showed the formation of a cluster of spongiotrophoblast cells in the labyrinth zone of the placenta of Tun-treated mice. The glycogen content of the fetal liver and placenta from Tun-treated mice was lower than that from control mice. Tun treatment decreased mRNA expression of Slc2a1/glucose transporter 1 (GLUT1), which is a major transporter for glucose, but increased placental mRNA levels of Slc2a3/GLUT3. Moreover, maternal exposure to Tun resulted in a decrease in vascular endothelial growth factor receptor-1 (VEGFR-1), VEGFR-2, and placental growth factor. These results suggest that excessive and exogenous ER stress may induce functional abnormalities in the placenta, at least in part, with altered GLUT and vascular-related gene expression, resulting in low infant birth weight. - Highlights: • Maternal exposure to excessive ER stress induced preterm birth and IUGR. • Prolonged excessive ER stress altered the formation of the placental labyrinth. • ER stress decreased GLUT1 mRNA expression in the placenta, but increased GLUT3. • ER stress-induced IUGR causes decreased glycogen and altered glucose transport.
Full Text Available Aim: Withania somnifera root extracts are often used in traditionally known Indian systems of medicine for prevention and cure of psychosomatic disorders. The reported experiment was designed to test whether low daily oral doses of such extracts are also effective in suppressing marble burying behaviour in stressed mice or not. Materials and Methods: Groups of mice treated with 10, 20 or 40 mg/kg daily oral doses of Withania somnifera root (WSR extract were subjected to a foot shock stress induced hyperthermia test on the 1st, 5th, 7th and 10th day of the experiment. On the 11th and 12th treatment days, they were subjected to marble burying tests. Stress response suppressing effects of low dose WSR were estimated by its effects on body weight and basal core temperature of animals during the course of the experiment. Results: Alterations in bodyweight and basal core temperature triggered by repeated exposures to foot shock stress were absent even in the 10 mg/kg/day WSR treated group, whereas effectiveness of the extract in foot shock stress induced hyperthermia and marble burying tests increased with its increasing daily dose. Conclusion: Marble burying test in stressed mice are well suited for identifying bioactive constituents of Withania somnifera like medicinal plants with adaptogenic, anxiolytic and antidepressant activities, or for quantifying pharmacological interactions between them. [J Complement Med Res 2016; 5(3.000: 274-277
Young, D.Z.; Massachusetts General Hospital, Boston; Dimsdale, J.E.; Moore, R.H.; Barlai-Kovach, M.; Newell, J.B.; McKusick, K.A.; Boucher, C.A.; Fifer, M.A.; Strauss, H.W.
Left ventricular ejection fraction, systolic blood pressure and plasma norepinephrine were measured in six normotensive and six mildly hypertensive subjects during rest and psychological stress. Compared with rest, 8 of the 12 subjects developed significant changes in ejection fraction (increase in 6, decrease in 2); 10 of 12 subjects developed significant elevations of plasma norepinephrine; and all developed significant increases in systolic blood pressure. When the stress effects were examined for the total group, as opposed to within subjects, there were significant increases in plasma norepinephrine and systolic blood pressure but, interestingly, mean ejection fraction and stroke volume remained unchanged, implying stress led to increased left ventricular contractility. (orig.)
Choudhury, Shuvasish; Sharma, Parul
Chickpea (Cicer arietinum L.) roots were treated with aluminum (Al3+) in calcium chloride (CaCl2) solution (pH 4.7) and growth responses along with physiological and metabolic changes were investigated. Al3+ treatment for 7d resulted in a dose dependent decline of seed germination and inhibition of root growth. A significant (p ≤ 0.05) decline in fresh and dry biomass were observed after 7d of Al3+ stress.The root growth (length) was inhibited after 24 and 48 h of stress imposition. The hydrogen peroxide (H2O2) levels increased significantly (p ≤ 0.05) with respect to control in Al3+ treated roots. The hematoxylin and Evans blue assay indicated significant (p ≤ 0.05) accumulation of Al3+ in the roots and loss of plasma membrane integrity respectively. The time-course evaluation of lipid peroxidation showed increase in malondialdehyde (MDA) after 12, 24 and 48 h of stress imposition. Al3+ treatment did not alter the MDA levels after 2 or 4 h of stress, however, a minor increase was observed after 6 and 10 h of treatment. The proton (1H) nuclear magnetic resonance (NMR) spectrum of the perchloric acid extracts showed variation in the abundance of metabolites and suggested a major metabolic shift in chickpea root during Al3+ stress. The key differences that were observed include changes in energy metabolites. Accumulation of phenolic compounds suggested its possible role in Al3+ exclusion in roots during stress. The results suggested that Al3+ alters growth pattern in chickpea and induces reactive oxygen species (ROS) production that causes physiological and metabolic changes.
Baraibar, Martin A; Hyzewicz, Janek; Rogowska-Wrzesinska, Adelina
Although increased oxidative stress has been associated with the impairment of proliferation and function of adult human muscle stem cells, proteins either involved in the stress response or damaged by oxidation have not been identified. A parallel proteomics approach was performed for analyzing...... the protein expression profile as well as proteins preferentially oxidized upon hydrogen peroxide-induced oxidative stress. Fifteen proteins involved in the oxidative stress response were identified. Among them, protein spots identified as peroxiredoxins 1 and 6, glyceraldehyde-3-phosphate dehydrogenase......, and α-enolase were shifted to a more acidic isoelectric point upon oxidative stress, indicating posttranslational modifications. Oxidized proteins were evidenced by immunodetection of derivatized carbonyl groups followed by identification by mass spectrometry. The carbonylated proteins identified...
Mulak, Agata; Taché, Yvette
Stressors of different psychological, physical or immune origin play a critical role in the pathophysiology of irritable bowel syndrome participating in symptoms onset, clinical presentation as well as treatment outcome. Experimental stress models applying a variety of acute and chronic exteroceptive or interoceptive stressors have been developed to target different periods throughout the lifespan of animals to assess the vulnerability, the trigger and perpetuating factors determining stress influence on visceral sensitivity and interactions within the brain-gut axis. Recent evidence points towards adequate construct and face validity of experimental models developed with respect to animals' age, sex, strain differences and specific methodological aspects such as non-invasive monitoring of visceromotor response to colorectal distension as being essential in successful identification and evaluation of novel therapeutic targets aimed at reducing stress-related alterations in visceral sensitivity. Underlying mechanisms of stress-induced modulation of visceral pain involve a combination of peripheral, spinal and supraspinal sensitization based on the nature of the stressors and dysregulation of descending pathways that modulate nociceptive transmission or stress-related analgesic response. PMID:21860814
Neckameyer, Wendi S.
The stress response in Drosophila melanogaster reveals sex differences in behavior, similar to what has been observed in mammals. However, unlike mammals, the sex determination pathway in Drosophila is well established, making this an ideal system to identify factors involved in the modulation of sex-specific responses to stress. In this study, we show that the Drosophila fat body, which has been shown to be important for energy homeostasis and sex determination, is a dynamic tissue that is altered in response to stress in a sex and time-dependent manner. We manipulated the sex determination pathway in the fat body via targeted expression of transformer and transformer-2 and analyzed these animals for changes in their response to stress. In the majority of cases, manipulation of transformer or transformer-2 was able to change the physiological output in response to starvation and oxidative stress to that of the opposite sex. Our data also uncover the possibility of additional downstream targets for transformer and transformer-2 that are separate from the sex determination pathway and can influence behavioral and physiological responses. PMID:24789992
Laurence, A; Houdelier, C; Calandreau, L; Arnould, C; Favreau-Peigné, A; Leterrier, C; Boissy, A; Lumineau, S
Animals perceiving repeated aversive events can become chronically stressed. Chronic activation of the hypothalamic-pituitary-adrenal (HPA) axis can have deleterious consequences on physiological parameters (e.g. BW, blood chemistry) and behaviour (e.g. emotional reactivity, stereotypies, cognition). Environmental enrichment (EE) can be a mean to reduce animal stress and to improve welfare. The aim of this study was first, to assess the effects of EE in battery cages on the behaviour of young Japanese quail and second, to evaluate the impact of EE on quail exposed to chronic stress. The experiment involved quail housed in EE cages and submitted or not to a chronic stress procedure (CSP) (EE cages, control quail: n=16, CSP quail: n=14) and quail housed in standard cages and exposed or not to the CSP (standard non-EE cages, control quail: n=12, CSP quail: n=16). Our procedure consisted of repeated aversive events (e.g. ventilators, delaying access to food, physical restraint, noise) presented two to five times per 24 h, randomly, for 15 days. During CSP, EE improved quail's welfare as their stereotypic pacing decreased and they rested more. CSP decreased exploration in all quail. After the end of CSP, quail presented increased emotional reactivity in emergence test. However, the effect of EE varied with test. Finally, chronic stress effects on comfort behaviours in the emergence test were alleviated by EE. These results indicate that EE can alleviate some aspects of behavioural alterations induced by CSP.
Full Text Available Recent studies indicate multiple roles for integrin αvβ3 in adult neurons, including response to pharmacological agents such as cocaine and selective serotonin reuptake inhibitors. In this study, we examined the role of the integrin β3 gene (Itgb3 in the response to environmental stimuli by subjecting Itgb3+/+ and Itgb3−/− mice to unpredictable chronic mild stressors. We found that genetic abrogation of integrin β3 expression elicits an exaggerated vulnerability to chronic unpredictable stress in the open field test. In this test, chronic stress elicited significant decreases in stereotypic behavior and horizontal locomotor activity, including increases in anxiety behaviors. Mild chronic stress led to reductions in dopamine turnover in midbrains of Itgb3+/+, but not Itgb3−/− mice, suggesting a disruption of stress-dependent regulation of DA homeostasis. Chronic stress elicited altered synaptic expression of syntaxin and synaptophysin in midbrains of Itgb3−/− mice, when compared to Itgb3+/+. Semi-quantitative Western blot studies revealed that the synaptic expression, but not total tissue expression, of multiple signaling proteins is correlated with integrin αv levels in the midbrain. Moreover, loss of integrin β3 expression modifies this correlation network. Together, these findings demonstrate that Itgb3−/− mice display a pattern of changes indicating disrupted regulation of midbrain synaptic systems involved in conferring resilience to mild stressors.
Santosh K. Yadav
Full Text Available Pediatric HIV patients often suffer with neurodevelopmental delay and subsequently cognitive impairment. While tissue injury in cortical and subcortical regions in the brain of adult HIV patients has been well reported there is sparse knowledge about these changes in perinatally HIV infected pediatric patients. We analyzed cortical thickness, subcortical volume, structural connectivity, and neurocognitive functions in pediatric HIV patients and compared with those of pediatric healthy controls. With informed consent, 34 perinatally infected pediatric HIV patients and 32 age and gender matched pediatric healthy controls underwent neurocognitive assessment and brain magnetic resonance imaging (MRI on a 3 T clinical scanner. Altered cortical thickness, subcortical volumes, and abnormal neuropsychological test scores were observed in pediatric HIV patients. The structural network connectivity analysis depicted lower connection strengths, lower clustering coefficients, and higher path length in pediatric HIV patients than healthy controls. The network betweenness and network hubs in cortico-limbic regions were distorted in pediatric HIV patients. The findings suggest that altered cortical and subcortical structures and regional brain connectivity in pediatric HIV patients may contribute to deficits in their neurocognitive functions. Further, longitudinal studies are required for better understanding of the effect of HIV pathogenesis on brain structural changes throughout the brain development process under standard ART treatment.
Weik, Ulrike; Deinzer, Renate
Though postawakening cortisol is considered to be altered under chronic stress prospective studies proving this assumption is missing, so far. Furthermore, there is some uncertainty which aspects of postawakening cortisol alterations are strongest related to stress. The present study thus analyzed the cortisol concentration at awakening itself (0 min), the cortisol awakening response (CAR; i.e. the increase within 30 min after awakening), the area under the curve of the first hour after awakening (AUC(G)60) and the mean of samples taken 0 min and 30 min after awakening (AUC(G)30) in 12 exam students, participating in a major exam and 12 matched control students not participating in any exam. Saliva samples were taken on two consecutive days at 0, 15, 30, 45, and 60 min after awakening, respectively, at four time points (T1-T4): on the verge of exams, when students anticipated and prepared the exam (T1), in the middle of exams (T2), and shortly after (T3). T4 (weeks after exams) represents a reference measure. Repeated measures analyses of covariance revealed a significantly higher AUC(G)30 (p=0.007) and AUC(G)60 (p=0.011) and higher cortisol concentrations at awakening (p=0.016) in exam students and a significant time by group interaction for concentration at awakening (p=0.031). No effects were found for the CAR. The results of this prospective controlled study support notions that chronic stress induces increases of overall postawakening cortisol. They further indicate that the CAR is not affected by chronic stress and that the awakening concentration responds later than the AUC(G) to conditions of chronic stress as analyzed here. Copyright 2010 Elsevier Inc. All rights reserved.
Buller, K M; Crane, J W; Spencer, S J; Day, T A
Apomorphine is a dopamine receptor agonist that was recently licensed for the treatment of erectile dysfunction. However, although sexual activity can be stressful, there has been little investigation into whether treatments for erectile dysfunction affect stress responses. We have examined whether a single dose of apomorphine, sufficient to produce penile erections (50 microg/kg, i.a.), can alter basal or stress-induced plasma ACTH levels, or activity of central pathways thought to control the hypothalamic-pituitary-adrenal axis in rats. An immune challenge (interleukin-1 beta, 1 microg/kg, i.a.) was used as a physical stressor while sound stress (100 dB white noise, 30 min) was used as a psychological stressor. Intravascular administration of apomorphine had no effect on basal ACTH levels but did substantially increase the number of Fos-positive amygdala and nucleus tractus solitarius catecholamine cells. Administration of apomorphine prior to immune challenge augmented the normal ACTH response to this stressor at 90 min and there was a corresponding increase in the number of Fos-positive paraventricular nucleus corticotropin-releasing factor cells, paraventricular nucleus oxytocin cells and nucleus tractus solitarius catecholamine cells. However, apomorphine treatment did not alter ACTH or Fos responses to sound stress. These data suggest that erection-inducing levels of apomorphine interfere with hypothalamic-pituitary-adrenal axis inhibitory feedback mechanisms in response to a physical stressor, but have no effect on the response to a psychological stressor. Consequently, it is likely that apomorphine acts on a hypothalamic-pituitary-adrenal axis control pathway that is unique to physical stressors. A candidate for this site of action is the nucleus tractus solitarius catecholamine cell population and, in particular, A2 noradrenergic neurons.
Szewczyk, Bernadeta; Kotarska, Katarzyna; Daigle, Mireille; Misztak, Paulina; Sowa-Kucma, Magdalena; Rafalo, Anna; Curzytek, Katarzyna; Kubera, Marta; Basta-Kaim, Agnieszka; Nowak, Gabriel; Albert, Paul R
The effect of stress on the mRNA and protein level of the 5-HT1A receptor and two of its key transcriptional modulators, NUDR and Freud-1, was examined in the prefrontal cortex (PFC) and hippocampus (Hp) using rodent models: olfactory bulbectomy (OB) and prenatal stress (PS) in male and female rats; chronic mild stress in male rats (CMS) and pregnancy stress. In PFC, CMS induced the most widespread changes, with significant reduction in both mRNA and protein levels of NUDR, 5-HT1A receptor and in Freud-1 mRNA; while in Hp 5-HT1A receptor and Freud-1 protein levels were also decreased. In male, but not female OB rats PFC Freud-1 and 5-HT1A receptor protein levels were reduced, while in Hp 5-HT1A receptor, Freud-1 and NUDR mRNA's but not protein were reduced. In PS rats PFC 5-HT1A receptor protein was reduced more in females than males; while in Hp Freud-1 protein was increased in females. In pregnancy stress, PFC NUDR, Freud-1 and 5-HT1A protein receptor levels were reduced, and in HP 5-HT1A receptor protein levels were also reduced; in HP only NUDR and Freud-1 mRNA levels were reduced. Overall, CMS and stress during pregnancy produced the most salient changes in 5-HT1A receptor and transcription factor expression, suggesting a primary role for altered transcription factor expression in chronic regulation of 5-HT1A receptor expression. By contrast, OB (in males) and PS (in females) produced gender-specific reductions in PFC 5-HT1A receptor protein levels, suggesting a role for post-transcriptional regulation. These and previous data suggest that chronic stress might be a key regulator of NUDR/Freud-1 gene expression.
Cordero, M I; Just, N; Poirier, G L; Sandi, C
Early-life stress and biological predispositions are linked to mood and personality disorders related to aggressive behavior. We previously showed that exposure to peripubertal stress leads to increased anxiety-like behaviors and aggression against males and females, as well as increased aggression against females in their male offspring. Here, we investigated whether paternal (pS) and individual (iS) exposure to peripubertal stress may exert additive effects on the long-term programming of anxiety-like and aggressive behaviors in rats. Given the key role of the lateral septum (LS) in the regulation of anxiety and aggressive behaviors and the hypothesized alterations in balance between neural excitation and inhibition in aggression-related disorders, markers for these processes were examined in the LS. Peripubertal stress was applied both in naïve male rats and in the offspring of peripubertally stressed males, and anxiety-like and aggressive behaviors were assessed at adulthood. Proton magnetic resonance spectroscopy at 6-months, and post-mortem analysis of glutamic acid decarboxylase 67 (GAD67) at 12-months were conducted in LS. We confirmed that aggressive behavior was increased by pS and iS, while only iS increased anxiety-like behavior. Individual stress led to reduced GABA, confirmed by reduced GAD67 immunolabelling, and increased glutamate, N-acetyl-aspartate, phosphocholine and creatine; while pS specifically led to reduced phosphocreatine. pS and iS do not interact and exert a differential impact on the analyzed aspects of brain function and anxiety-like behaviors. These data support the view that early-life stress can affect the behavioral and neurodevelopmental trajectories of individuals and their offspring, which may involve different neurobiological mechanisms. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.
Macan, Therese Hoff; And Others
The relationships between time management of college students and self-reported academic performance and various affective measures of stress were explored for 123 undergraduates. The study indicates that self-reported time management is multidimensional and that there are important relationships among time management, performance, and stress.…
Sime, Wesley E.; And Others
Administered the Mathematics Anxiety Rating Scale to Introductory Statistics college students. A high mathematics anxiety was associated with lower performance on a statistics examination. Classroom stress-coping intervention reduced anxiety and physiological stress responses, but did not improve academic performance. (Author/KS)
The study investigates the relationship between occupational stress factors and job performance among some Nigerian industrial workers (n = 300, males = 133, females = 67, mean age = 47.3, SD = 5.6). The Occupational Stress Questionnaire and Workers' Performance Rating Scale were employed to collect data from ...
Kauts, Amit; Sharma, Neelam
Academic performance is concerned with the quantity and quality of learning attained in a subject or group of subjects after a long period of instruction. Excessive stress hampers students' performance. Improvement in academic performance and alertness has been reported in several yogic studies. The main objective of the study was to assess the effect of yoga on academic performance in relation to stress. The study started with 800 adolescent students; 159 high-stress students and 142 low-stress students were selected on the basis of scores obtained through Stress Battery. Experimental group and control group were given pre test in three subjects, i.e., Mathematics, Science, and Social Studies. A yoga module consisting of yoga asanas, pranayama, meditation, and a value orientation program was administered on experimental group for 7 weeks. The experimental and control groups were post-tested for their performance on the three subjects mentioned above. The results show that the students, who practiced yoga performed better in academics. The study further shows that low-stress students performed better than high-stress students, meaning thereby that stress affects the students' performance.
Full Text Available Background: Academic performance is concerned with the quantity and quality of learning attained in a subject or group of subjects after a long period of instruction. Excessive stress hampers students′ performance. Improvement in academic performance and alertness has been reported in several yogic studies. Aims and Objectives: The main objective of the study was to assess the effect of yoga on academic performance in relation to stress. Materials and Methods: The study started with 800 adolescent students; 159 high-stress students and 142 low-stress students were selected on the basis of scores obtained through Stress Battery. Experimental group and control group were given pre test in three subjects, i.e., Mathematics, Science, and Social Studies. A yoga module consisting of yoga asanas, pranayama, meditation, and a value orientation program was administered on experimental group for 7 weeks. The experimental and control groups were post-tested for their performance on the three subjects mentioned above. Results: The results show that the students, who practiced yoga performed better in academics. The study further shows that low-stress students performed better than high-stress students, meaning thereby that stress affects the students′ performance.
The evaluation of the effect of crowding stress on growth performance of juvenile Clarias gariepinus fed varying crude protein levels might be useful in determining the optimal stocking density in relation to optimal dietary crude protein level and consequently better growth performance. The effect of crowding stress on ...
Kauts, Amit; Sharma, Neelam
Background: Academic performance is concerned with the quantity and quality of learning attained in a subject or group of subjects after a long period of instruction. Excessive stress hampers students’ performance. Improvement in academic performance and alertness has been reported in several yogic studies. Aims and Objectives: The main objective of the study was to assess the effect of yoga on academic performance in relation to stress. Materials and Methods: The study started with 800 adolescent students; 159 high-stress students and 142 low-stress students were selected on the basis of scores obtained through Stress Battery. Experimental group and control group were given pre test in three subjects, i.e., Mathematics, Science, and Social Studies. A yoga module consisting of yoga asanas, pranayama, meditation, and a value orientation program was administered on experimental group for 7 weeks. The experimental and control groups were post-tested for their performance on the three subjects mentioned above. Results: The results show that the students, who practiced yoga performed better in academics. The study further shows that low-stress students performed better than high-stress students, meaning thereby that stress affects the students’ performance. PMID:21234215
Borchini, Rossana; Veronesi, Giovanni; Bonzini, Matteo; Gianfagna, Francesco; Dashi, Oriana; Ferrario, Marco Mario
The deregulation of the autonomic nervous system assessed through the heart rate variability (HRV) analysis is a promising pathway linking work stress and cardiovascular diseases. We aim to investigate the associations between HRV High Frequency (HF) and Low Frequency (LF) powers and work stress in a sample of 36 healthy nurses. Perceived work stress was assessed twice one year apart, using the Job Content and Effort Reward Imbalance questionnaires. This allows to classify nurses in three exposure groups: "prolonged high stress" (PHS), "recent high stress" (RHS) and "stable low stress" (SLS). A 24-h ECG monitoring was later performed during a working day (WD) and a subsequent resting day (RD). Statistically significantly lower ( p working periods. In the subsequent resting periods, HF means showed increases over time in the RHS (beta = +0.41, p working and resting periods. Our study evidences that both prolonged and recent perceived high work stress were associated with a reduction of HF and LF powers during work. In addition, prolonged stress was associated with a lack of recovery during not-working and resting periods.
Markus, C.R.; Panhuysen, G.; Jonkman, L.M.; Bachman, M.
Cognitive performance has been found to decline after exposure to stress, particularly in stress-prone subjects. The present study investigated whether a carbohydrate-rich, protein-poor (CR/PP) diet, which may enhance cerebral serotonin function in stress-prone subjects due to increases in the
Kauts Amit; Sharma Neelam
Background: Academic performance is concerned with the quantity and quality of learning attained in a subject or group of subjects after a long period of instruction. Excessive stress hampers students′ performance. Improvement in academic performance and alertness has been reported in several yogic studies. Aims and Objectives: The main objective of the study was to assess the effect of yoga on academic performance in relation to stress. Materials and Methods: The study started ...
Hertel, Johannes; König, Johanna; Homuth, Georg
Using oral contraceptives has been implicated in the aetiology of stress-related disorders like depression. Here, we followed the hypothesis that oral contraceptives deregulate the HPA-axis by elevating circulating cortisol levels. We report for a sample of 233 pre-menopausal women increased...... circulating cortisol levels in those using oral contraceptives. For women taking oral contraceptives, we observed alterations in circulating phospholipid levels and elevated triglycerides and found evidence for increased glucocorticoid signalling as the transcript levels of the glucocorticoid-regulated genes...... DDIT4 and FKBP5 were increased in whole blood. The effects were statistically mediated by cortisol. The associations of oral contraceptives with higher FKBP5 mRNA and altered phospholipid levels were modified by rs1360780, a genetic variance implicated in psychiatric diseases. Accordingly...
de Andrade, J S; Céspedes, I C; Abrão, R O; Dos Santos, T B; Diniz, L; Britto, L R G; Spadari-Bratfisch, R C; Ortolani, D; Melo-Thomas, L; da Silva, R C B; Viana, M B
Previous results show that elevated T-maze (ETM) avoidance responses are facilitated by acute restraint. Escape, on the other hand, was unaltered. To examine if the magnitude of the stressor is an important factor influencing these results, we investigated the effects of unpredictable chronic mild stress (UCMS) on ETM avoidance and escape measurements. Analysis of Fos protein immunoreactivity (Fos-ir) was used to map areas activated by stress exposure in response to ETM avoidance and escape performance. Additionally, the effects of the UCMS protocol on the number of cells expressing the marker of migrating neuroblasts doublecortin (DCX) in the hippocampus were investigated. Corticosterone serum levels were also measured. Results showed that UCMS facilitates ETM avoidance, not altering escape. In unstressed animals, avoidance performance increases Fos-ir in the cingulate cortex, hippocampus (dentate gyrus) and basomedial amygdala, and escape increases Fos-ir in the dorsolateral periaqueductal gray and locus ceruleus. In stressed animals submitted to ETM avoidance, increases in Fos-ir were observed in the cingulate cortex, ventrolateral septum, hippocampus, hypothalamus, amygdala, dorsal and median raphe nuclei. In stressed animals submitted to ETM escape, increases in Fos-ir were observed in the cingulate cortex, periaqueductal gray and locus ceruleus. Also, UCMS exposure decreased the number of DCX-positive cells in the dorsal and ventral hippocampus and increased corticosterone serum levels. These data suggest that the anxiogenic effects of UCMS are related to the activation of specific neurobiological circuits that modulate anxiety and confirm that this stress protocol activates the hypothalamus-pituitary-adrenal axis and decreases hippocampal adult neurogenesis. Copyright © 2013 Elsevier B.V. All rights reserved.
Dembele, Korami; Yao, Xing-Hai; Chen, Li; Nyomba, B L Grégoire
Prenatal ethanol (EtOH) exposure is associated with low birth weight, followed by increased appetite, catch-up growth, insulin resistance, and impaired glucose tolerance in the rat offspring. Because EtOH can induce oxidative stress, which is a putative mechanism of insulin resistance, and because of the central role of the hypothalamus in the regulation of energy homeostasis and insulin action, we investigated whether prenatal EtOH exposure causes oxidative damage to the hypothalamus, which may alter its function. Female rats were given EtOH by gavage throughout pregnancy. At birth, their offspring were smaller than those of non-EtOH rats. Markers of oxidative stress and expression of neuropeptide Y and proopiomelanocortin (POMC) were determined in hypothalami of postnatal day 7 (PD7) and 3-mo-old (adult) rat offspring. In both PD7 and adult rats, prenatal EtOH exposure was associated with decreased levels of glutathione and increased expression of MnSOD. The concentrations of lipid peroxides and protein carbonyls were normal in PD7 EtOH-exposed offspring, but were increased in adult EtOH-exposed offspring. Both PD7 and adult EtOH-exposed offspring had normal neuropeptide Y and POMC mRNA levels, but the adult offspring had reduced POMC protein concentration. Thus only adult offspring preexposed to EtOH had increased hypothalamic tissue damage and decreased levels of POMC, which could impair melanocortin signaling. We conclude that prenatal EtOH exposure causes hypothalamic oxidative stress, which persists into adult life and alters melanocortin action during adulthood. These neuroendocrine alterations may explain weight gain and insulin resistance in rats exposed to EtOH early in life.
Courtney E. Cross
Full Text Available The relationship between oxidative stress and miRNA changes in placenta as a potential mechanism involved in preeclampsia (PE is not fully elucidated. We investigated the impact of oxidative stress on miRNAs and mRNA expression profiles of genes associated with PE in villous 3A first trimester trophoblast cells exposed to H2O2 at 12 different concentrations (0-1 mM for 0.5, 4, 24, and 48 h. Cytotoxicity, determined using the SRB assay, was used to calculate the IC50 of H2O2. RNA was extracted after 4 h exposure to H2O2 for miRNA and gene expression profiling. H2O2 exerted a concentration- and time-dependent cytotoxicity on 3A trophoblast cells. Short-term exposure of 3A cells to low concentration of H2O2 (5% of IC50 significantly altered miRNA profile as evidenced by significant changes in 195 out of 595 evaluable miRNAs. Tool for annotations of microRNAs (TAM analysis indicated that these altered miRNAs fall into 43 clusters and 34 families, with 41 functions identified. Exposure to H2O2 altered mRNA expression of 22 out of 84 key genes involved in dysregulation of placental development. In conclusion, short-term exposure of villous first trimester trophoblasts to low concentrations of H2O2 significantly alters miRNA profile and expression of genes implicated in placental development.
Marrelli, Massimo; Gentile, Stefano; Palmieri, Francesca; Paduano, Francesco; Tatullo, Marco
In the present work we analyzed the hormonal (salivary Cortisol; sC), immune (salivary Immunoglobulin A; sIgA) and cardiovascular (Heart rate, HR, and systolic blood pressure, SBP) responses induced by stress conditions in oral surgeons, randomly recruited according to their expertise level. Each surgeon performed three different surgical procedures with increasing degrees of technical difficulty and under time-limited conditions, to assess whether these variants may influence the risks of stress-induced secondary hypertension among the involved health professionals. sC and sIgA samples and cardiovascular function measurements were taken up before, during, and two hours after every surgery. Salivary samples and cardiovascular measurements were taken also during non-surgical days, as baseline controls. We observed that more experienced surgeons showed a higher stress management ability compared to those with less experience or, generally, younger, which are more exposed to the risks of developing secondary hypertension. Nevertheless, indipendently of sex and experience, oral surgeons are constantly exposed to high risks of developing stress-related diseases. On the basis of the issues addressed and the results obtained, we have highlighted the importance of the investigated stress biomarkers to monitor and to prevent stress-related pathologies among oral surgeons. This approach is aimed to emphasize the significance of these specific stress-biomarkers, which represent a powerful instrument to evaluate stress levels in oral surgeons, and that may help to reduce the most severe life-threatening risks to which they are daily exposed. In conclusion, final goal of this study is to suggest an useful guideline to monitor the stress levels of oral and maxillofacial surgeons in order to improve their quality of life, which is inevitably reflected on the quality of the performances provided and, finally, to prevent possible mistakes in their daily activities.
Full Text Available In the present work we analyzed the hormonal (salivary Cortisol; sC, immune (salivary Immunoglobulin A; sIgA and cardiovascular (Heart rate, HR, and systolic blood pressure, SBP responses induced by stress conditions in oral surgeons, randomly recruited according to their expertise level.Each surgeon performed three different surgical procedures with increasing degrees of technical difficulty and under time-limited conditions, to assess whether these variants may influence the risks of stress-induced secondary hypertension among the involved health professionals. sC and sIgA samples and cardiovascular function measurements were taken up before, during, and two hours after every surgery. Salivary samples and cardiovascular measurements were taken also during non-surgical days, as baseline controls.We observed that more experienced surgeons showed a higher stress management ability compared to those with less experience or, generally, younger, which are more exposed to the risks of developing secondary hypertension. Nevertheless, indipendently of sex and experience, oral surgeons are constantly exposed to high risks of developing stress-related diseases.On the basis of the issues addressed and the results obtained, we have highlighted the importance of the investigated stress biomarkers to monitor and to prevent stress-related pathologies among oral surgeons. This approach is aimed to emphasize the significance of these specific stress-biomarkers, which represent a powerful instrument to evaluate stress levels in oral surgeons, and that may help to reduce the most severe life-threatening risks to which they are daily exposed. In conclusion, final goal of this study is to suggest an useful guideline to monitor the stress levels of oral and maxillofacial surgeons in order to improve their quality of life, which is inevitably reflected on the quality of the performances provided and, finally, to prevent possible mistakes in their daily activities.
Shahram Hashemnia; Somayeh Abadiyan; Behnam Ghorbani Fard
This paper presents an empirical investigation on the effects of occupational stress, psychological stress as well as job burnout on women’s employee performance in city of Karaj, Iran. The proposed study designs a questionnaire in Likert scale and distributes it among all female employees who worked for Bank Maskan in this city. In our survey, employee performance consists of three parts of interpersonal performance, job performance as well as organizational performance. Cronbach alpha has b...
Lepletier, Ailin; de Carvalho, Vinicius Frias; e Silva, Patricia Machado Rodrigues; Villar, Silvina; Pérez, Ana Rosa; Savino, Wilson; Morrot, Alexandre
We have previously shown that experimental infection caused by Trypanosoma cruzi is associated with changes in the hypothalamus-pituitary-adrenal axis. Increased glucocorticoid (GC) levels are believed to be protective against the effects of acute stress during infection but result in depletion of CD4+CD8+ thymocytes by apoptosis, driving to thymic atrophy. However, very few data are available concerning prolactin (PRL), another stress-related hormone, which seems to be decreased during T. cruzi infection. Considering the immunomodulatory role of PRL upon the effects caused by GC, we investigated if intrathymic cross-talk between GC and PRL receptors (GR and PRLR, respectively) might influence T. cruzi-induced thymic atrophy. Using an acute experimental model, we observed changes in GR/PRLR cross-activation related with the survival of CD4+CD8+ thymocytes during infection. These alterations were closely related with systemic changes, characterized by a stress hormone imbalance, with progressive GC augmentation simultaneously to PRL reduction. The intrathymic hormone circuitry exhibited an inverse modulation that seemed to counteract the GC-related systemic deleterious effects. During infection, adrenalectomy protected the thymus from the increase in apoptosis ratio without changing PRL levels, whereas an additional inhibition of circulating PRL accelerated the thymic atrophy and led to an increase in corticosterone systemic levels. These results demonstrate that the PRL impairment during infection is not caused by the increase of corticosterone levels, but the opposite seems to occur. Accordingly, metoclopramide (MET)-induced enhancement of PRL secretion protected thymic atrophy in acutely infected animals as well as the abnormal export of immature and potentially autoreactive CD4+CD8+ thymocytes to the periphery. In conclusion, our findings clearly show that Trypanosoma cruzi subverts mouse thymus homeostasis by altering intrathymic and systemic stress
Full Text Available The study analyzed caryopses of barley (Hordeum vulgare cv. Stratus. Caryopses were germinated in darkness at 20°C in three experimental setups: (a in distilled water for 24 hours, followed by 100 mM NaCl for another 24 hours (salinity stress, SS, (b in 100 μM of abscisic acid for the first 24 hours, followed by rinsing with distilled water to remove residual ABA, and in 100 mM NaCl for another 24 hours (ABA pretreatment + salinity stress, ABAS, (c in distilled water only (control, C. Changes in the content of free polysomes (FP, membrane-bound polysomes (MBP, cytoskeleton-bound polysomes (CBP and cytomatrix-bound polysomes (CMBP were examined in barley sprouts germinated in SS and ABAS treatments for 48 hours. In salt-stressed barley sprouts, the concentrations of membrane-bound and cytoskeleton-bound polysomes (MBP, CBP and CMBP decreased significantly, whereas an increase was noted only in the free polysome (FP fraction. ABA pretreatment altered the distribution of polysomes in stressed plants. The content of cytoskeletonbound polysomes (CBP and CMBP increased, FP levels decreased, whereas no changes in MBP content were observed in response to ABA treatment. Our results suggest that plants respond to salt stress by increasing the concentrations of free polysomes that are probably released from damaged cell structures, mainly membranes. Our present and previous findings indicate that ABA could inhibit the release of FP in stressed plants by enhancing polysome binding to the cytoskeleton.
Sharma, Kamal Dev; Nayyar, Harsh
Cold stress at reproductive phase in susceptible chickpea (Cicer arietinum L.) leads to pollen sterility induced flower abortion. The tolerant genotypes, on the other hand, produce viable pollen and set seed under cold stress. Genomic information on pollen development in cold-tolerant chickpea under cold stress is currently unavailable. DDRT-PCR analysis was carried out to identify anther genes involved in cold tolerance in chickpea genotype ICC16349 (cold-tolerant). A total of 9205 EST bands were analyzed. Cold stress altered expression of 127 ESTs (90 up-regulated, 37 down-regulated) in anthers, more than two third (92) of which were novel with unknown protein identity and function. Remaining about one third (35) belonged to several functional categories such as pollen development, signal transduction, ion transport, transcription, carbohydrate metabolism, translation, energy and cell division. The categories with more number of transcripts were carbohydrate/triacylglycerol metabolism, signal transduction, pollen development and transport. All but two transcripts in these categories were up-regulated under cold stress. To identify time of regulation after stress and organ specificity, expression levels of 25 differentially regulated transcripts were also studied in anthers at six time points and in four organs (anthers, gynoecium, leaves and roots) at four time points. Limited number of genes were involved in regulating cold tolerance in chickpea anthers. Moreover, the cold tolerance was manifested by up-regulation of majority of the differentially expressed transcripts. The anthers appeared to employ dual cold tolerance mechanism based on their protection from cold by enhancing triacylglycerol and carbohydrate metabolism; and maintenance of normal pollen development by regulating pollen development genes. Functional characterization of about two third of the novel genes is needed to have precise understanding of the cold tolerance mechanisms in chickpea anthers.
Full Text Available BACKGROUND: Acute stress is a stereotypical, but multimodal response to a present or imminent challenge overcharging an organism. Among the different branches of this multimodal response, the consequences of glucocorticoid secretion have been extensively investigated, mostly in connection with long-term memory (LTM. However, stress responses comprise other endocrine signaling and altered neuronal activity wholly independent of pituitary regulation. To date, knowledge of the impact of such "paracorticoidal" stress responses on higher cognitive functions is scarce. We investigated the impact of an ecological stressor on the ability to direct selective attention using event-related potentials in humans. Based on research in rodents, we assumed that a stress-induced imbalance of catecholaminergic transmission would impair this ability. METHODOLOGY/PRINCIPAL FINDINGS: The stressor consisted of a single cold pressor test. Auditory negative difference (Nd and mismatch negativity (MMN were recorded in a tonal dichotic listening task. A time series of such tasks confirmed an increased distractibility occurring 4-7 minutes after onset of the stressor as reflected by an attenuated Nd. Salivary cortisol began to rise 8-11 minutes after onset when no further modulations in the event-related potentials (ERP occurred, thus precluding a causal relationship. This effect may be attributed to a stress-induced activation of mesofrontal dopaminergic projections. It may also be attributed to an activation of noradrenergic projections. Known characteristics of the modulation of ERP by different stress-related ligands were used for further disambiguation of causality. The conjuncture of an attenuated Nd and an increased MMN might be interpreted as indicating a dopaminergic influence. The selective effect on the late portion of the Nd provides another tentative clue for this. CONCLUSIONS/SIGNIFICANCE: Prior studies have deliberately tracked the adrenocortical influence
Díaz-Muñoz, Mauricio; Alvarez-Pérez, Marco Antonio; Yáñez, Lucía; Vidrio, Susana; Martínez, Lidia; Rosas, Gisele; Yáñez, Mario; Ramírez, Sotero; de Sánchez, Victoria Chagoya
Myocardial Ca(2+) overload and oxidative stress are well documented effects associated to isoproterenol (ISO)-induced myocardial necrosis, but information correlating these two issues is scarce. Using an ISO-induced myocardial infarction model, 3 stages of myocardial damage were defined: pre-infarction (0-12 h), infarction (12-24 h) and post-infarction (24-96 h). Alterations in Ca(2+) homeostasis and oxidative stress were studied in mitochondria, sarcoplasmic reticulum and plasmalemma by measuring the Ca(2+) content, the activity of Ca(2+) handling proteins, and by quantifying TBARs, nitric oxide (NO) and oxidative protein damage (changes in carbonyl and thiol groups). Free radicals generated system, antioxidant enzymes and oxidative stress (GSH/GSSG ratio) were also monitored at different times of ISO-induced cardiotoxicity. The Ca(2+) overload induced by ISO was counterbalanced by a diminution in the ryanodine receptor activity and the Na(+)-Ca(+2) exchanger as well as by the increase in both calcium ATPases activities (vanadate- and thapsigargine-sensitive) and mitochondrial Ca(2+) uptake during pre-infarction and infarction stages. Pro-oxidative reactions and antioxidant defences during the 3 stages of cardiotoxicity were observed, with maximal oxidative stress during the infarction. Significant correlations were found among pro-oxidative reactions with plasmalemma and sarcoplasmic reticulum Ca(2+) ATPases, and ryanodine receptor activities at the onset and development of ISO-induced infarction. These findings could be helpful in the design of antioxidant therapies in this pathology.
Varlinskaya, Elena I; Doremus-Fitzwater, Tamara L; Spear, Linda P
Human adolescents consume alcohol largely to enhance social interactions. Adolescent, but not adult rats likewise exhibit ethanol-induced social facilitation under low-stress circumstances. Since the relationship between stress and ethanol sensitivity across ontogeny still has yet to be well explored, the present study sought to characterize possible age-associated differences in the influence of stressor exposure on ethanol-induced changes in social behavior in adolescent [postnatal days (P) 30-36] and adult (P65-71) male and female Sprague-Dawley rats. Animals were repeatedly restrained (90min/day) for 5days, followed by examination of ethanol-induced (0, 0.25, 0.5, 0.75, or 1.0g/kg) alterations in social behaviors on the last day. Results revealed typical age-related differences in sensitivity to ethanol among controls, with adolescents being uniquely sensitive to low-dose ethanol stimulation of social investigation and play fighting, but less sensitive than adults to the social suppression emerging at higher doses. At both ages, stressor exposure decreased sensitivity to social inhibitory effects of ethanol, while augmenting expression of ethanol's social facilitatory effects. Ethanol also attenuated the stress-related suppression of social motivation at both ages. These results suggest that repeated stressor exposure diminishes age-related differences in the social consequences of ethanol, with stress enhancing ethanol-induced social facilitation across age. Copyright 2010 Elsevier Inc. All rights reserved.
Cheryl A Frye
Full Text Available Maternal-offspring interactions begin prior to birth. Experiences of the mother during gestation play a powerful role in determining the developmental programming of the central nervous system. In particular, stress during gestation alters developmental programming of the offspring resulting in susceptibility to sex-typical and stress-sensitive neurodevelopmental, neuropsychiatric and neurodegenerative disorders. However, neither these effects, nor the underlying mechanisms, are well understood. Our hypothesis is that allopregnanolone, during gestation, plays a particularly vital role in mitigating effects of stress on the developing fetus and may mediate, in part, alterations apparent throughout the lifespan. Specifically, altered balance between glucocorticoids and progestogens during critical periods of development (stemming from psychological, immunological, and/or endocrinological stressors during gestation may permanently influence behavior, brain morphology, and/or neuroendocrine-sensitive processes. 5α-reduced progestogens are integral in the developmental programming of sex-typical, stress-sensitive, and/or disorder-relevant phenotypes. Prenatal stress may alter these responses and dysregulate allopregnanolone and its normative effects on stress axis function. As an example of a neurodevelopmental, neuropsychiatric and/or neurodegenerative process, this review focuses on responsiveness to drugs of abuse, which is sensitive to prenatal stress and progestogen milieu. This review explores the notion that allopregnanolone may effect, or be influenced by, prenatal stress, with consequences for neurodevelopmental-, neuropsychiatric- and/or neurodegenerative- relevant processes, such as addiction.
the Navy, LT John Price, Psy.D. (Command Psychologist, Naval Special Warfare Center), and CDR Eric Potterat, Ph.D. (U.S. Special Operations Command...The Navy’s approach to encouraging positive self-talk is based on the ABC model (Ellis and Dryden , 1987), which represents a method for restructuring...team performance. Academy of Management Journal, 49(3), 576–589. Ellis, A., and W. Dryden (1987). The Practice of Rational-Emotive Therapy (RET
Boucher, Helene; Ryan, Charlene A.
Performance anxiety is a common experience among musicians. Recent studies have found it to be an issue not only for adult performers but also for developing musicians as early as third grade. The question as to its developed or innate nature led to the present inquiry pertaining to young children's responses to performance situations. Sixty-six…
Eui Seok Shin
Full Text Available Astrocytes are macroglial cells that have a crucial role in development of the retinal vasculature and maintenance of the blood-retina-barrier (BRB. Diabetes affects the physiology and function of retinal vascular cells including astrocytes (AC leading to breakdown of BRB. However, the detailed cellular mechanisms leading to retinal AC dysfunction under high glucose conditions remain unclear. Here we show that high glucose conditions did not induce the apoptosis of retinal AC, but instead increased their rate of DNA synthesis and adhesion to extracellular matrix proteins. These alterations were associated with changes in intracellular signaling pathways involved in cell survival, migration and proliferation. High glucose conditions also affected the expression of inflammatory cytokines in retinal AC, activated NF-κB, and prevented their network formation on Matrigel. In addition, we showed that the attenuation of retinal AC migration under high glucose conditions, and capillary morphogenesis of retinal endothelial cells on Matrigel, was mediated through increased oxidative stress. Antioxidant proteins including heme oxygenase-1 and peroxiredoxin-2 levels were also increased in retinal AC under high glucose conditions through nuclear localization of transcription factor nuclear factor-erythroid 2-related factor-2. Together our results demonstrated that high glucose conditions alter the function of retinal AC by increased production of inflammatory cytokines and oxidative stress with significant impact on their proliferation, adhesion, and migration.
Morrone, Maurilio da Silva; Behr, Guilherme Antônio; Gasparotto, Juciano; Bortolin, Rafael Calixto; da Boit Martinello, Katia; Saldanha Henkin, Bernardo; Rabello, Thallita Kelly; Zanotto-Filho, Alfeu; Gelain, Daniel Pens; Moreira, José Cláudio Fonseca
The aim of this study was to investigate the potential of curcumin oral supplementation (50 and 100 mg/Kg/day, for 30 days) in circumventing menopause-associated oxidative stress and lipid profile dysfunctions in a rat ovariectomy (OVX) model. Female Wistar rats were operated and randomly divided into either sham-operated or OVX groups. Sham-operated group (n = 8) and one OVX group (n = 11) were treated with vehicle (refined olive oil), and the other two OVX groups received curcumin at 50 or 100 mg/Kg/day doses (n = 8/group). OVX vehicle-treated animals presented a higher deposition of intestinal adipose tissue as well as increased serum levels of IL-6, LDL, and total cholesterol when compared to sham-operated rats. In addition, several oxidative stress markers in serum, blood, and liver (such as TBARS, carbonyl, reduced-sulphydryl, and nonenzymatic antioxidant defenses) were altered toward a prooxidant status by OVX. Interestingly, curcumin supplementation attenuated most of these parameters to sham comparable values. Thus, the herein presented results show that curcumin may be useful to ameliorate lipid metabolism alterations and oxidative damage associated with hormone deprivation in menopause. PMID:26640615
Figueira, Fernanda Hernandes; Aguiar, Lais Mattos de; Rosa, Carlos Eduardo da
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 Â© 2016 Elsevier Inc. All rights reserved.
Liu, Yang; Li, Baojuan; Zhang, Xi; Zhang, Linchuan; Li, Liang; Lu, Hongbing
To explore the alteration in cerebral blood flow (CBF) and functional connectivity between survivors with recent onset post-traumatic stress disorder (PTSD) and without PTSD, survived from the same coal mine flood disaster. In this study, a processing pipeline using arterial spin labeling (ASL) sequence was proposed. Considering low spatial resolution of ASL sequence, a linear regression method was firstly used to correct the partial volume (PV) effect for better CBF estimation. Then the alterations of CBF between two groups were analyzed using both uncorrected and PV-corrected CBF maps. Based on altered CBF regions detected from the CBF analysis as seed regions, the functional connectivity abnormities in PTSD patients was investigated. The CBF analysis using PV-corrected maps indicates CBF deficits in the bilateral frontal lobe, right superior frontal gyrus and right corpus callosum of PTSD patients, while only right corpus callosum was identified in uncorrected CBF analysis. Furthermore, the regional CBF of the right superior frontal gyrus exhibits significantly negative correlation with the symptom severity in PTSD patients. The resting-state functional connectivity indicates increased connectivity between left frontal lobe and right parietal lobe. These results indicate that PV-corrected CBF exhibits more subtle perfusion changes and may benefit further perfusion and connectivity analysis. The symptom-specific perfusion deficits and aberrant connectivity in above memory-related regions may be putative biomarkers for recent onset PTSD induced by a single prolonged trauma exposure and help predict the severity of PTSD.
Henderson, Roselinde K.; Snyder, Hannah R.; Gupta, Tina; Banich, Marie T.
The ability to engage in goal-directed behavior despite exposure to stress is critical to resilience. Questions of how stress can impair or improve behavioral functioning are important in diverse settings, from athletic competitions to academic testing. Previous research suggests that controllability is a key factor in the impact of stress on behavior: learning how to control stressors buffers people from the negative effects of stress on subsequent cognitively demanding tasks. In addition, research suggests that the impact of stress on cognitive functioning depends on an individual’s response to stressors: moderate responses to stress can lead to improved performance while extreme (high or low) responses can lead to impaired performance. The present studies tested the hypothesis that (1) learning to behaviorally control stressors leads to improved performance on a test of general executive functioning, the color-word Stroop, and that (2) this improvement emerges specifically for people who report moderate (subjective) responses to stress. Experiment 1: Stroop performance, measured before and after a stress manipulation, was compared across groups of undergraduate participants (n = 109). People who learned to control a noise stressor and received accurate performance feedback demonstrated reduced Stroop interference compared with people exposed to uncontrollable noise stress and feedback indicating an exaggerated rate of failure. In the group who learned behavioral control, those who reported moderate levels of stress showed the greatest reduction in Stroop interference. In contrast, in the group exposed to uncontrollable events, self-reported stress failed to predict performance. Experiment 2: In a second sample (n = 90), we specifically investigated the role of controllability by keeping the rate of failure feedback constant across groups. In the group who learned behavioral control, those who reported moderate levels of stress showed the greatest
Henderson, Roselinde K; Snyder, Hannah R; Gupta, Tina; Banich, Marie T
The ability to engage in goal-directed behavior despite exposure to stress is critical to resilience. Questions of how stress can impair or improve behavioral functioning are important in diverse settings, from athletic competitions to academic testing. Previous research suggests that controllability is a key factor in the impact of stress on behavior: learning how to control stressors buffers people from the negative effects of stress on subsequent cognitively demanding tasks. In addition, research suggests that the impact of stress on cognitive functioning depends on an individual's response to stressors: moderate responses to stress can lead to improved performance while extreme (high or low) responses can lead to impaired performance. The present studies tested the hypothesis that (1) learning to behaviorally control stressors leads to improved performance on a test of general executive functioning, the color-word Stroop, and that (2) this improvement emerges specifically for people who report moderate (subjective) responses to stress. Experiment 1: Stroop performance, measured before and after a stress manipulation, was compared across groups of undergraduate participants (n = 109). People who learned to control a noise stressor and received accurate performance feedback demonstrated reduced Stroop interference compared with people exposed to uncontrollable noise stress and feedback indicating an exaggerated rate of failure. In the group who learned behavioral control, those who reported moderate levels of stress showed the greatest reduction in Stroop interference. In contrast, in the group exposed to uncontrollable events, self-reported stress failed to predict performance. Experiment 2: In a second sample (n = 90), we specifically investigated the role of controllability by keeping the rate of failure feedback constant across groups. In the group who learned behavioral control, those who reported moderate levels of stress showed the greatest Stroop
Meerlo, P.; Koehl, M.; van der Borght, K.; Turek, F. W.
Chronic sleep restriction is an increasing problem in many countries and may have many, as yet unknown, consequences for health and well being. Studies in both humans and rats suggest that sleep deprivation may activate the hypothalamic-pituitary-adrenal (HPA) axis, one of the main neuroendocrine stress systems. However, few attempts have been made to examine how sleep loss affects the HPA axis response to subsequent stressors. Furthermore, most studies applied short-lasting total sleep deprivation and not restriction of sleep over a longer period of time, as often occurs in human society. Using the rat as our model species, we investigated: (i) the HPA axis activity during and after sleep deprivation and (ii) the effect of sleep loss on the subsequent HPA response to a novel stressor. In one experiment, rats were subjected to 48 h of sleep deprivation by placing them in slowly rotating wheels. Control rats were placed in nonrotating wheels. In a second experiment, rats were subjected to an 8-day sleep restriction protocol allowing 4 h of sleep each day. To test the effects of sleep loss on subsequent stress reactivity, rats were subjected to a 30-min restraint stress. Blood samples were taken at several time points and analysed for adrenocorticotropic hormone (ACTH) and corticosterone. The results show that ACTH and corticosterone concentrations were elevated during sleep deprivation but returned to baseline within 4 h of recovery. After 1 day of sleep restriction, the ACTH and corticosterone response to restraint stress did not differ between control and sleep deprived rats. However, after 48 h of total sleep deprivation and after 8 days of restricted sleep, the ACTH response to restraint was significantly reduced whereas the corticosterone response was unaffected. These results show that sleep loss not only is a mild activator of the HPA axis itself, but also affects the subsequent response to stress. Alterations in HPA axis regulation may gradually appear under
Samuel James Vine
Full Text Available The aim of this article is to present an integrative conceptual framework that depicts the effect of acute stress on the performance of visually guided motor skills. We draw upon seminal theories highlighting the importance of subjective interpretations of stress on subsequent performance and outline how models of disrupted attentional control might explain this effect through impairments in visuomotor control. We first synthesize and critically discuss empirical support for theories examining these relationships in isolation. We then outline our integrative framework that seeks to provide a more complete picture of the interacting influences of stress responses (challenge and threat and attention in explaining how elevated stress may lead to different visuomotor performance outcomes. We propose a number of mechanisms that explain why evaluations of stress are related to attentional control, and highlight the emotion of anxiety as the most likely candidate to explain why negative reactions to stress lead to disrupted attention and poor visuomotor skill performance. Finally, we propose a number of feedback loops that explain why stress responses are often self-perpetuating, as well as a number of proposed interventions that are designed to help improve or maintain performance in real world performance environments (e.g., sport, surgery, military, and aviation.
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.
Yarom, Orli; Maroun, Mouna; Richter-Levin, Gal
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. PMID:18301720
Hunziker, Sabina; Laschinger, Laura; Portmann-Schwarz, Simone; Semmer, Norbert K; Tschan, Franziska; Marsch, Stephan
Barriers to optimal performance of cardiopulmonary resuscitation may partly relate to human factors, such as stress and specific emotions. The aim of this study was to investigate whether mental stress and different perceived emotions have a negative impact on the performance of rescuers. This prospective, observational study was conducted at the Simulator Center of the University Hospital Basel, Switzerland. A total of 120 medical students (70% female) participated in teams of three. They reported levels of perceived stress, feeling overwhelmed, motivation and specific emotions before, during, and after a simulated resuscitation. The association of stress/overload (index of stress and feeling overwhelmed), motivation, and specific emotions with resuscitation performance defined as hands-on time during the first 180 s after cardiac arrest was investigated. During resuscitation, levels of stress/overload, motivation, and negative emotions were significantly higher as compared to the periods before and after resuscitation. In contrast, positive emotions were highest before and after resuscitation and significantly lower during resuscitation. In general, females reported higher stress/overload and negative emotions, whereas males reported more positive emotions. A multivariate linear regression model showed negative associations of stress/overload (regression coefficient -18.12, 95% CI -30.73, -5.51, p = 0.006) and positive associations of motivation (regression coefficient 13.45, 95% CI 0.95, 25.95, p = 0.036) with resuscitation performance. A simulated cardiac arrest caused substantial perceived stress/overload and negative emotions, particularly in female students, which adversely impacted resuscitation performance. Further studies are required to expand our findings to more experienced medical professionals and investigate whether stress coping strategies improve resuscitation performance.
This study examined the relationship between level of stress and students' academic performance in Universities in Kwara State, Nigeria. The study adopted a descriptive survey research design. Proportional stratified random sampling was used to select 300 students for the study. A “Students' Stress Level Questionnaire ...
This study focused on identifying whether certain factors affected the academic performance of Soldiers attending an Army educational institution. Academic performance was measured by the grade percentile average of the participant upon the completion of their course of enrollment. Factors that were considered within the study through…
Roselinde Kaiser Henderson
Full Text Available The ability to engage in goal-directed behavior despite exposure to stress is critical to resilience. Questions of how stress can impair or improve behavioral functioning are important in diverse settings, from athletic competitions to academic testing to clinical therapy. Previous research suggests that controllability is a key factor in the impact of stress on behavior: learning how to control stressors buffers people from the negative effects of stress on subsequent cognitively demanding tasks. In addition, research suggests that the impact of stress on cognitive functioning depends on an individual’s response to stressors: moderate responses to stress can lead to improved performance while extreme (high or low responses can lead to impaired performance. The present studies tested the hypothesis that 1 learning to behaviorally control stressors leads to improved performance on a test of general executive functioning, the color-word Stroop, and that 2 this improvement emerges specifically for people who report moderate (subjective responses to stress. Experiment 1: Stroop performance, measured before and after a stress manipulation, was compared across groups of undergraduate participants (n=109. People who learned to control a noise stressor and received accurate performance feedback demonstrated reduced Stroop interference compared with people exposed to uncontrollable noise stress and feedback indicating an exaggerated rate of failure. In the group who learned behavioral control, those who reported moderate levels of stress showed the greatest reduction in Stroop interference. In contrast, in the group exposed to uncontrollable events, self-reported stress failed to predict performance. Experiment 2: In a second sample (n=90, we specifically investigated the role of controllability by keeping the rate of failure feedback constant across groups. In the group who learned behavioral control, those who reported moderate levels of stress
Full Text Available Neonatal handling induces several behavioral and neurochemical alterations in pups, including decreased responses to stress and reduced fear in new environments. However, there are few reports in the literature concerning the behavioral effects of this neonatal intervention on the dams during the postpartum period. Therefore, the aim of the current study was to determine if brief postpartum separation from pups has a persistent impact on the dam's stress response and behavior. Litters were divided into two neonatal groups: 1 non-handled and 2 handled [10 min/day, from postnatal day (PND 1 to 10]. Weaning occurred at PND 21 when behavioral tasks started to be applied to the dams, including sweet food ingestion (PND 21, forced swimming test (PND 28, and locomotor response to a psychostimulant (PND 28. On postpartum day 40, plasma was collected at baseline for leptin assays and after 1 h of restraint for corticosterone assay. Regarding sweet food consumption, behavior during the forced swimming test or plasma leptin levels did not differ between dams briefly separated and non-separated from their pups during the postpartum period. On the other hand, both increased locomotion in response to diethylpropion and increased corticosterone secretion in response to acute stress were detected in dams briefly separated from their pups during the first 10 postnatal days. Taken together, these findings suggest that brief, repeated separations from the pups during the neonatal period persistently impact the behavior and induce signs of dopaminergic sensitization in the dam.
Full Text Available Neonatal handling induces several behavioral and neurochemical alterations in pups, including decreased responses to stress and reduced fear in new environments. However, there are few reports in the literature concerning the behavioral effects of this neonatal intervention on the dams during the postpartum period. Therefore, the aim of the current study was to determine if brief postpartum separation from pups has a persistent impact on the dam's stress response and behavior. Litters were divided into two neonatal groups: 1 non-handled and 2 handled [10 min/day, from postnatal day (PND 1 to 10]. Weaning occurred at PND 21 when behavioral tasks started to be applied to the dams, including sweet food ingestion (PND 21, forced swimming test (PND 28, and locomotor response to a psychostimulant (PND 28. On postpartum day 40, plasma was collected at baseline for leptin assays and after 1 h of restraint for corticosterone assay. Regarding sweet food consumption, behavior during the forced swimming test or plasma leptin levels did not differ between dams briefly separated and non-separated from their pups during the postpartum period. On the other hand, both increased locomotion in response to diethylpropion and increased corticosterone secretion in response to acute stress were detected in dams briefly separated from their pups during the first 10 postnatal days. Taken together, these findings suggest that brief, repeated separations from the pups during the neonatal period persistently impact the behavior and induce signs of dopaminergic sensitization in the dam.
Fucà, Giuseppe; Dinelli, Maurizio; Gianfranchi, Lorella; Bressan, Sabrina; Lamborghini, Catia; Alboni, Paolo
There are conflicting reports on the presence of subtle haemodynamic alterations during orthostatic stress in subjects with vasovagal syncope (VVS). The aim of the present study was to investigate whether young/middle-aged subjects with VVS show abnormal responses to orthostatic stress. Four groups of subjects underwent tilt testing (TT) during the passive phase and, if negative, after nitroglycerin administration: Group I, 20 subjects with a history of syncope and positive passive TT; Group II, 23 subjects with a history of syncope and TT positive after nitroglycerin; Group III, 23 subjects with a history of syncope and negative TT; and Group IV, 20 normal control subjects. Heart rate, systolic, diastolic, and mean blood pressure, stroke volume, cardiac output, and total peripheral resistance were computed from pressure pulsations (Modelflow). The demographic data and the values of the haemodynamic variables in the supine position did not differ significantly among the four groups. The per cent changes in these variables did not differ significantly among the four groups after 2 and 5 min of TT and among Groups II, III, and IV, 2 min after nitroglycerin administration. Young/middle-aged subjects with VVS have a normal measured haemodynamic response to orthostatic stress; therefore, the vasovagal reflex is not secondary to an impairment of the primary vasoconstrictive mechanism.
Full Text Available Armillaria mellea is a major plant pathogen. Yet, the strategies the organism uses to infect susceptible species, degrade lignocellulose and other plant material and protect itself against plant defences and its own glycodegradative arsenal are largely unknown. Here, we use a combination of gel and MS-based proteomics to profile A. mellea under conditions of oxidative stress and changes in growth matrix. 2-DE and LC-MS/MS were used to investigate the response of A. mellea to H2O2 and menadione/FeCl3 exposure, respectively. Several proteins were detected with altered abundance in response to H2O2, but not menadione/FeCl3 (i.e., valosin-containing protein, indicating distinct responses to these different forms of oxidative stress. One protein, cobalamin-independent methionine synthase, demonstrated a common response in both conditions, which may be a marker for a more general stress response mechanism. Further changes to the A. mellea proteome were investigated using MS-based proteomics, which identified changes to putative secondary metabolism (SM enzymes upon growth in agar compared to liquid cultures. Metabolomic analyses revealed distinct profiles, highlighting the effect of growth matrix on SM production. This establishes robust methods by which to utilize comparative proteomics to characterize this important phytopathogen.
Collins, Cassandra; Hurley, Rachel; Almutlaqah, Nada; O'Keeffe, Grainne; Keane, Thomas M; Fitzpatrick, David A; Owens, Rebecca A
Armillaria mellea is a major plant pathogen. Yet, the strategies the organism uses to infect susceptible species, degrade lignocellulose and other plant material and protect itself against plant defences and its own glycodegradative arsenal are largely unknown. Here, we use a combination of gel and MS-based proteomics to profile A. mellea under conditions of oxidative stress and changes in growth matrix. 2-DE and LC-MS/MS were used to investigate the response of A. mellea to H₂O₂ and menadione/FeCl₃ exposure, respectively. Several proteins were detected with altered abundance in response to H₂O₂, but not menadione/FeCl₃ (i.e., valosin-containing protein), indicating distinct responses to these different forms of oxidative stress. One protein, cobalamin-independent methionine synthase, demonstrated a common response in both conditions, which may be a marker for a more general stress response mechanism. Further changes to the A. mellea proteome were investigated using MS-based proteomics, which identified changes to putative secondary metabolism (SM) enzymes upon growth in agar compared to liquid cultures. Metabolomic analyses revealed distinct profiles, highlighting the effect of growth matrix on SM production. This establishes robust methods by which to utilize comparative proteomics to characterize this important phytopathogen.
Sun, Hongli; Su, Qian; Zhang, Huifang; Liu, Weimin; Zhang, Huiping; Ding, Ding; Zhu, Zhongliang; Li, Hui
To clarify the alterations of proliferation and differentiation of hippocampal cells in prenatally stressed rats. We investigated the impact of prenatal restraint stress on the hipocampal cell proliferation in the progeny with 5-bromo-2'-deoxyuridine (BrdU), which is a marker of proliferating cells and their progeny. In addition, we observed the differentiation of neural stem cells (NSCs) with double labeling of BrdU/neurofilament (NF), BrdU/glial fibrillary acidic protein (GFAP) in the hipocampus. Prenatal stress (PS) increased cell proliferation in the dentate gyrus (DG) only in female and neuron differentiation of newly divided cells in the DG and CA4 in both male and female. Moreover, the NF and GFAP-positive cells, but not the BrdU-positive cells, BrdU/NF and BrdU/GFAP-positive cells, were found frequently in the CA3 and CA1 in the offspring of each group. These results possibly suggest a compensatory adaptive response to neuronal damage or loss in hippocampus induced by PS. Copyright © 2014 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.
Gaoua, Nadia; Racinais, Sebastien; Grantham, Justin; El Massioui, Farid
The objectives of this study were to (1) assess the effect of passive heating upon attention and memory task performance, and (2) evaluate the effectiveness of the application of cold packs to the head on preserving these functions. Using a counter-balance design 16 subjects underwent three trials: a control (CON, 20°C, 40% rH), hot (HOT, 50°C, 50% rH) and hot with the head kept cool (HHC). In each condition, three attention tests and two memory tests were performed. Mean core, forehead and tympanic temperatures were all significantly higher (p HOT (38.6° ±0.1°, 39.6° ± 0.2° and 38.8°±0.1°C, respectively) and HHC (38° ± 0.2, 37.7° ± 0.3° and 37.7°C, respectively) than in CON (37.1° ± 0.6°, 33.3° ± 0.2° and 35.9° ± 0.3°C, respectively). Results indicate that there was impairment in working memory with heat exposure (p packs only prevented the detrimental effect of hyperthermia on short-term memory. Our results show that impairments in cognitive function with passive hyperthermia and the beneficial effect of head cooling are task dependent and suggests that exposure to a hot environment is a competing variable to the cognitive processes.
He Xuhong; Wei Li; Zhao Bingquan [Tsinghua Univ., Nuclear Power Plant Simulation Training Center, Beijing (China)
Reactor operators may be exposed to significant levels of stress during plant emergencies and their performance may be affected by the stress. This paper first identified the potential sources of stress in the nuclear power plant, then discussed the ways in which stress is likely to affect the reactor operators, and finally identified several training approaches for reducing or eliminating stress effects. The challenges for effective stress reducing training may seem daunting, yet the challenges are real and must be addressed. This paper reviewed researches in training design, knowledge and skill acquisition, and training transfer point to a number of strategies that can be used to address these challenges and lead to more effective training and development. (author)
He Xuhong; Wei Li; Zhao Bingquan
Reactor operators may be exposed to significant levels of stress during plant emergencies and their performance may be affected by the stress. This paper first identified the potential sources of stress in the nuclear power plant, then discussed the ways in which stress is likely to affect the reactor operators, and finally identified several training approaches for reducing or eliminating stress effects. The challenges for effective stress reducing training may seem daunting, yet the challenges are real and must be addressed. This paper reviewed researches in training design, knowledge and skill acquisition, and training transfer point to a number of strategies that can be used to address these challenges and lead to more effective training and development. (author)
Arora, Sonal; Russ, Stephanie; Petrides, K V; Sirimanna, Pramudith; Aggarwal, Rajesh; Darzi, Ara; Sevdalis, Nick
Poor stress management skills can compromise performance in the operating room, particularly in inexperienced trainees. Little is known about individual differences in managing stress. This study aimed to explore the relationship between trait emotional intelligence (EI) and objective and subjective measures of stress in medical students faced with unfamiliar surgical tasks. Seventeen medical undergraduates completed an unfamiliar laparoscopic task on a simulator during January to April 2008. Subjective stress before, during (retrospectively), and after the task was measured using the self-report State-Trait Anxiety Inventory. Objective stress was measured using continuous heart rate (HR) monitoring. Participants also completed the Trait Emotional Intelligence Questionnaire short form (TEIQue-SF). The authors computed scores for global trait EI and the TEIQue-SF four factors and carried out descriptive and correlational analyses. The highest levels of subjective stress were reported during the task and correlated positively with trait EI as well as with the trait EI factors of well-being and emotionality. Objective stress (mean HR) during the task was positively related to the sociability factor of trait EI. Higher trait EI scores were also associated with better after-task recovery from stress experienced during the task. Students with higher trait EI are more likely to experience stress during unfamiliar surgical scenarios but are also more likely to recover better compared with their lower-trait-EI peers. Trait EI has implications for the design of effective stress management training tailored to individual needs and potential applications to surgical trainee selection and development.
Tao, S; Monteiro, A P A; Hayen, M J; Dahl, G E
Heat stress during the dry period not only negatively affects a cow's performance but also affects her offspring. Previous studies indicate that calves born to cows heat-stressed during late gestation have lower birth weight but similar overall weight gain during the prepubertal period compared with those cooled in utero. However, it is unclear if whole-body insulin response, and thus metabolism, of calves is altered in their postnatal life after in utero heat stress. The aim of the present study was to examine the effects of maternal heat stress during the dry period on whole-body insulin response of calves after weaning. Calves (10/treatment) were born to cows exposed to heat stress (HT) or cooling (CL) when dry. Calves were immediately separated from their dams and fed 3.8L of high-quality colostrum within 1h after birth and then 1.9L 12h later. All calves were fed 1.9 to 3.8L of pasteurized milk in the morning and afternoon from 2 to 42 d of age and then only in the morning until weaning at 49 d. Calf starter and water were offered ad libitum starting at 2 d of age. All calves were managed in the same manner throughout the study. All calves were subjected to a glucose tolerance test (GTT) and an insulin challenge (IC) at 55 d of age. Calves heat-stressed in utero were born lighter (40 ± 1.4 vs. 45 ± 1.4 kg) compared with CL calves. Both groups of calves had similar weaning weights (HT: 68 ± 3.2 kg; CL: 71 ± 3.3 kg) and body weight gain from birth to weaning (HT: 28 ± 2.2 kg; CL: 26 ± 2.3 kg). Compared with those cooled in utero, HT calves had a similar insulin response to GTT and insulin clearance during IC but faster glucose clearance during GTT and IC. In conclusion, in addition to impaired fetal growth, maternal heat stress during the dry period enhances the whole-body insulin response of calves after weaning, which suggests the possibility of accelerated lipogenesis and fat deposition in early life. Copyright © 2014 American Dairy Science Association
Full Text Available Adolescence is a time of developmental changes and reorganization in the brain. It has been hypothesized that stress has a greater neurological impact on adolescents than on adults. However, scientific evidence in support of this hypothesis is still limited. We treated adolescent (4-week-old and adult (8-week-old rats with social instability stress for five weeks and compared the subsequent structural and functional changes to amygdala neurons. In the stress-free control condition, the adolescent group showed higher fear-potentiated startle responses, larger dendritic arborization, more proximal dendritic spine distribution and lower levels of truncated TrkB than the adult rats. Social instability stress exerted opposite effects on fear-potentiated startle responses in these two groups, i.e., the stress period appeared to hamper the performance in adolescents but improved it in adult rats. Furthermore, whilst the chronic social stress applied to adolescent rats reduced their dendritic field and spine density in basal and lateral amygdala neurons, the opposite stress effects on neuron morphology were observed in the adult rats. Moreover, stress in adolescence suppressed the amygdala expression of synaptic proteins, i.e., full-length TrkB and SNAP-25, whereas, in the adult rats, chronic stress enhanced full-length and truncated TrkB expressions in the amygdala. In summary, chronic social instability stress hinders amygdala neuron development in the adolescent brain, while mature neurons in the amygdala are capable of adapting to the stress. The stress induced age-dependent effects on the fear-potentiated memory may occur by altering the BDNF-TrkB signaling and neuroplasticity in the amygdala.
Jefferson, F; Ehlen, J C; Williams, N S; Montemarano, J J; Paul, K N
Although sleep disruptions that accompany stress reduce quality of life and deteriorate health, the mechanisms through which stress alters sleep remain obscure. Psychological stress can alter sleep in a variety of ways, but it has been shown to be particularly influential on rapid eye movement (REM) sleep. Prolactin (PRL), a sexually dimorphic, stress-sensitive hormone whose basal levels are higher in females, has somnogenic effects on REM sleep. In the current study, we examined the relationship between PRL secretion and REM sleep after restraint stress to determine whether: 1) the ability of stress to increase REM sleep is PRL-dependent, and 2) fluctuating PRL levels underlie sex differences in sleep responses to stress. Because dopamine D2 receptors in the pituitary gland are the primary regulator of PRL secretion, D2 receptor agonist, 1-[(6-allylergolin-8β-yl)-carbonyl]-1-[3-(dimethylamino) propyl]-3-ethylurea (cabergoline), was used to attenuate PRL levels in mice before 1 hour of restraint stress. Mice were implanted with electroencephalographic/electromyographic recording electrodes and received an ip injection of either 0.3-mg/kg cabergoline or vehicle before a control procedure of 1 hour of sleep deprivation by gentle handling during the light phase. Six days after the control procedure, mice received cabergoline or vehicle 15 minutes before 1 hour of restraint stress. Cabergoline blocked the ability of restraint stress to increase REM sleep amount in males but did not alter REM sleep amount after stress in females even though it reduced basal REM sleep amount in female controls. These data provide evidence that the ability for restraint stress to increase REM sleep is dependent on PRL and that sex differences in REM sleep amount may be driven by PRL.
Full Text Available The deregulation of the autonomic nervous system assessed through the heart rate variability (HRV analysis is a promising pathway linking work stress and cardiovascular diseases. We aim to investigate the associations between HRV High Frequency (HF and Low Frequency (LF powers and work stress in a sample of 36 healthy nurses. Perceived work stress was assessed twice one year apart, using the Job Content and Effort Reward Imbalance questionnaires. This allows to classify nurses in three exposure groups: “prolonged high stress” (PHS, “recent high stress” (RHS and “stable low stress” (SLS. A 24-h ECG monitoring was later performed during a working day (WD and a subsequent resting day (RD. Statistically significantly lower (p < 0.02 HF and LF means were found in PHS and RHS nurses during the working periods. In the subsequent resting periods, HF means showed increases over time in the RHS (beta = +0.41, p < 0.05, but not in PHS nurses. LF means did not show any substantial increases in the resting periods, in the PHS group with geometric means lower when compared to SLS, in the non-working and resting periods. Our study evidences that both prolonged and recent perceived high work stress were associated with a reduction of HF and LF powers during work. In addition, prolonged stress was associated with a lack of recovery during not-working and resting periods.
Full Text Available Objective. Stress-reducing therapies help maintain cognitive performance during stress. Aromatherapy is popular for stress reduction, but its effectiveness and mechanism are unclear. This study examined stress-reducing effects of aromatherapy on cognitive function using the go/no-go (GNG task performance and event related potentials (ERP components sensitive to stress. The study also assessed the importance of expectancy in aromatherapy actions. Methods. 81 adults were randomized to 3 aroma groups (active experimental, detectable, and undetectable placebo and 2 prime subgroups (prime suggesting stress-reducing aroma effects or no-prime. GNG performance, ERPs, subjective expected aroma effects, and stress ratings were assessed at baseline and poststress. Results. No specific aroma effects on stress or cognition were observed. However, regardless of experienced aroma, people receiving a prime displayed faster poststress median reaction times than those receiving no prime. A significant interaction for N200 amplitude indicated divergent ERP patterns between baseline and poststress for go and no-go stimuli depending on the prime subgroup. Furthermore, trends for beneficial prime effects were shown on poststress no-go N200/P300 latencies and N200 amplitude. Conclusion. While there were no aroma-specific effects on stress or cognition, these results highlight the role of expectancy for poststress response inhibition and attention.
Chamine, Irina; Oken, Barry S.
Objective. Stress-reducing therapies help maintain cognitive performance during stress. Aromatherapy is popular for stress reduction, but its effectiveness and mechanism are unclear. This study examined stress-reducing effects of aromatherapy on cognitive function using the go/no-go (GNG) task performance and event related potentials (ERP) components sensitive to stress. The study also assessed the importance of expectancy in aromatherapy actions. Methods. 81 adults were randomized to 3 aroma groups (active experimental, detectable, and undetectable placebo) and 2 prime subgroups (prime suggesting stress-reducing aroma effects or no-prime). GNG performance, ERPs, subjective expected aroma effects, and stress ratings were assessed at baseline and poststress. Results. No specific aroma effects on stress or cognition were observed. However, regardless of experienced aroma, people receiving a prime displayed faster poststress median reaction times than those receiving no prime. A significant interaction for N200 amplitude indicated divergent ERP patterns between baseline and poststress for go and no-go stimuli depending on the prime subgroup. Furthermore, trends for beneficial prime effects were shown on poststress no-go N200/P300 latencies and N200 amplitude. Conclusion. While there were no aroma-specific effects on stress or cognition, these results highlight the role of expectancy for poststress response inhibition and attention. PMID:25802539
Rossi, Lorenzo; Zhang, Weilan; Ma, Xingmao
Rapidly growing global population adds significant strains on the fresh water resources. Consequently, saline water is increasingly tapped for crop irrigation. Meanwhile, rapid advancement of nanotechnology is introducing more and more engineered nanoparticles into the environment and in agricultural soils. While some negative effects of ENPs on plant health at very high concentrations have been reported, more beneficial effects of ENPs at relatively low concentrations are increasingly noticed, opening doors for potential applications of nanotechnology in agriculture. In particular, we found that cerium oxide nanoparticles (CeO 2 NPs) improved plant photosynthesis in salt stressed plants. Due to the close connections between salt stress tolerance and the root anatomical structures, we postulated that CeO 2 NPs could modify plant root anatomy and improve plant salt stress tolerance. This study aimed at testing the hypothesis with Brassica napus in the presence of CeO 2 NPs (0, 500 mg kg -1 dry sand) and/or NaCl (0, 50 mM) in a growth chamber. Free hand sections of fresh roots were taken every seven days for three weeks and the suberin lamellae development was examined under a fluorescence microscope. The results confirmed the hypothesis that CeO 2 NPs modified the formation of the apoplastic barriers in Brassica roots. In salt stressed plants, CeO 2 NPs shortened the root apoplastic barriers which allowed more Na + transport to shoots and less accumulation of Na + in plant roots. The altered Na + fluxes and transport led to better physiological performance of Brassica and may lead to new applications of nanotechnology in agriculture. Copyright © 2017 Elsevier Ltd. All rights reserved.
Jammes, Y; Steinberg, J G; Mambrini, O; Brégeon, F; Delliaux, S
Because the muscle response to incremental exercise is not well documented in patients suffering from chronic fatigue syndrome (CFS), we combined electrophysiological (compound-evoked muscle action potential, M wave), and biochemical (lactic acid production, oxidative stress) measurements to assess any muscle dysfunction in response to a routine cycling exercise. This case-control study compared 15 CFS patients to a gender-, age- and weight-matched control group (n=11) of healthy subjects. All subjects performed an incremental cycling exercise continued until exhaustion. We measured the oxygen uptake (VO2), heart rate (HR), systemic blood pressure, percutaneous O2 saturation (SpO2), M-wave recording from vastus lateralis, and venous blood sampling allowing measurements of pH (pHv), PO2 (PvO2), lactic acid (LA), and three markers of the oxidative stress (thiobarbituric acid-reactive substances, TBARS, reduced glutathione, GSH, and ascorbic acid, RAA). Compared with control, in CFS patients (i) the slope of VO2 versus work load relationship did not differ from control subjects and there was a tendency for an accentuated PvO2 fall at the same exercise intensity, indicating an increased oxygen uptake by the exercising muscles; (ii) the HR and blood pressure responses to exercise did not vary; (iii) the anaerobic pathways were not accentuated; (iv) the exercise-induced oxidative stress was enhanced with early changes in TBARS and RAA and enhanced maximal RAA consumption; and (v) the M-wave duration markedly increased during the recovery period. The response of CFS patients to incremental exercise associates a lengthened and accentuated oxidative stress together with marked alterations of the muscle membrane excitability. These two objective signs of muscle dysfunction are sufficient to explain muscle pain and postexertional malaise reported by our patients.
Harker, A; Raza, S; Williamson, K; Kolb, B; Gibb, R
The goal of this research was to examine the effect of preconception paternal stress (PPS) on the subsequent neurodevelopment and behavior of male and female offspring. Prenatal (gestational) stress has been shown to alter brain morphology in the developing brain, and is presumed to be a factor in the development of some adult psychopathologies. Our hypothesis was that paternal stress in the preconception period could impact brain development in the offspring, leading to behavioral abnormalities later in life. The purpose of this study was to examine the effect of preconception paternal stress on developing male and female offspring brain morphology in five brain areas; medial prefrontal cortex (mPFC), orbitofrontal cortex (OFC), parietal cortex (Par1), hippocampus (CA1) and nucleus accumbens (NAc). Alterations in dendritic measures and spine density were observed in each brain area examined in paternal stress offspring. Our two main findings reveal; (1) PPS alters brain morphology and organization and these effects are different than the effects of stress observed at other ages; and, (2) the observed dendritic changes were sexually dimorphic. This study provides direct evidence that PPS modifies brain architecture in developing offspring, including dendritic length, cell complexity, and spine density. Alterations observed may contribute to the later development of psychopathologies and maladaptive behaviors in the offspring. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.
Helmreich, Dana L.; Tylee, Daniel; Christianson, John P.; Kubala, Kenneth H.; Govindarajan, Sindhuja T.; O’Neill, William E.; Becoats, Kyeesha; Watkins, Linda; Maier, Steve F.
Summary Exposure to traumatic stressors typically causes lasting changes in emotionality and behavior. However, coping strategies have been shown to prevent and alleviate many stress consequences and the biological mechanisms that underlie coping are of great interest. Whereas the laboratory stressor inescapable tail-shock induces anxiety-like behaviors, here we demonstrate that permitting a rat to chew on a wooden dowel during administration of tail-shock prevented the development of anxiety like behaviors in the open field and juvenile social exploration tests. Uncontrollable stressors increase corticosterone and decrease thyroid hormone, and we hypothesized that coping would blunt these changes. While tail-shock did produce these effects, active coping did not alter hormone levels. The dissociation between behavioral resilience and circulating hormones is discussed with regard to the utility of these molecules as biomarkers for psychiatric disease. PMID:22578266
Kou, H P; Li, Y; Song, X X; Ou, X F; Xing, S C; Ma, J; Von Wettstein, D; Liu, B
Cytosine methylation is responsive to various biotic- and abiotic-stresses, which may produce heritable epialleles. Nitrogen (N)-deficiency is an abiotic stress being repeatedly experienced by plants. To address possible epigenetic consequences of N-deficiency-stress, we investigated the stability of cytosine methylation in rice (Oryza sativa L.) subsequent to a chronic (a whole-generation) N-deficiency at two levels, moderate (20mg/L) and severe (10mg/L), under hydroponic culture. MSAP analysis revealed that locus-specific methylation alteration occurred in leaf-tissue of the stressed plants (S(0)) experiencing either level of N-deficiency, which was validated by gel-blotting. Analysis on three non-stressed self-fed progenies (S(1), S(2) and S(3)) by gel-blotting indicated that ca. 50% of the altered methylation patterns in somatic cells (leaf) of the stressed S(0) plants were recaptured in S(1), which were then stably inherited to S(2) and S(3). Bisulfite sequencing of two variant MSAP loci with homology to low-copy retrotransposons on one stressed plant (S(0)) and its non-stressed progenies (S(1) and S(2)) showed that whereas one locus exhibited limited and non-heritable CHH methylation alteration, the other locus manifested dramatic heritable hypermethylation at nearly all cytosine sites within the assayed region. Intriguingly, when two groups of S(2) plants descended from the same N-deficiency-stressed S(0) plant were re-subjected to the stress, the group inheriting the modified methylation patterns showed enhanced tolerance to the N-deficiency-stress compared with the group bearing the original patterns. Our results thus demonstrate heritability of an acquired adaptive trait in rice, which was accompanied by epigenetic inheritance of modified cytosine methylation patterns, implicating an epigenetic basis underlying the inheritance of an acquired trait in plants. Copyright © 2011 Elsevier GmbH. All rights reserved.
Glenn, Daniel E; Acheson, Dean T; Geyer, Mark A; Nievergelt, Caroline M; Baker, Dewleen G; Risbrough, Victoria B
It is unknown how traumatic brain injury (TBI) increases risk for posttraumatic stress disorder (PTSD). One potential mechanism is via alteration of fear-learning processes that could affect responses to trauma memories and cues. We utilized a prospective, longitudinal design to determine if TBI is associated with altered fear learning and extinction, and if fear processing mediates effects of TBI on PTSD symptom change. Eight hundred fifty two active-duty Marines and Navy Corpsmen were assessed before and after deployment. Assessments included TBI history, PTSD symptoms, combat trauma and deployment stress, and a fear-potentiated startle task of fear acquisition and extinction. Startle response and self-reported expectancy and anxiety served as measures of fear conditioning, and PTSD symptoms were measured with the Clinician-Administered PTSD Scale. Individuals endorsing "multiple hit" exposure (both deployment TBI and a prior TBI) showed the strongest fear acquisition and highest fear expression compared to groups without multiple hits. Extinction did not differ across groups. Endorsing a deployment TBI was associated with higher anxiety to the fear cue compared to those without deployment TBI. The association of deployment TBI with increased postdeployment PTSD symptoms was mediated by postdeployment fear expression when recent prior-TBI exposure was included as a moderator. TBI associations with increased response to threat cues and PTSD symptoms remained when controlling for deployment trauma and postdeployment PTSD diagnosis. Deployment TBI, and multiple-hit TBI in particular, are associated with increases in conditioned fear learning and expression that may contribute to risk for developing PTSD symptoms. © 2017 Wiley Periodicals, Inc.
Costin Madalina - Adriana
Full Text Available Nowadays, in times of economic crisis, most managers or entrepreneurs have to cope with a lot of new job challenges which can easily transform into stressors. Work related stress is of growing concern because it has significant economic implications for the organization. Even if some stress is a normal part of life, excessive stress can influence one's productivity, health and emotions and it has to be taken under control. When people lose confidence, they refuse to take responsibilities, they get quickly irritated, they are unsatisfied of their job, their performance will be very low and the organization will be in danger. Fortunately, most managers and entrepreneurs know which stress main symptoms are and have the necessary knowledge for managing and reducing it before it can affect employees' daily work. Stress can have an impact both on the organizational welfare and on personal behavior of supervisors or employees, that's why, the ability of managing it can make the difference between job's success or failure. The purpose of this paper is to study Romanian managers and entrepreneurs from Bihor County's perception regarding the stress phenomenon, if they feel that they are affected by stress, if they promote some methods to reduce it and if they consider that stress can influence the organizational performance. As a research method we used an online questionnaire, applied to a number of 75 managers and entrepreneurs that represent the target group of the project "Flexibility and performance through management", project financed by the European Social Fund - "Invest in people". Each participant had to answer a number of 35 questions regarding stress and the results will be presented in this paper. The main conclusion is that, even if job itself is seen as a stressor, there are other important factors that can produce stress such as: family problems, personal problems or social problems.
Barreto-Medeiros, Jairza; Queiros-Santos, Adenilda; Cabral-Filho, José Eulálio; Ferreira E Silva, Wylla Tatiana; Leandro, Carol Góis; Deiró, Tereza Cristina; Manhaes-de-Castro, Raul; Machado Barbosa de-Castro, Célia Maria
Neonatal malnutrition induces metabolic and endocrine changes that have beneficial effects on the neonatal in the short term but, in the longer term, these alterations lead to maladaptations. We investigated the effect of neonatal malnutrition on immune responses in adult rats submitted or not to an aggressiveness test. Male Wistar rats were distributed to one of two groups according to their mothers' diet during lactation: the well-nourished group (group C, n = 42, receiving 23% of protein) and the malnourished group (group MN, n = 42, receiving 8% of protein). After weaning, all rats received normoproteic diet. Ninety days after birth, each group was subdivided into three subgroups: control rats (n = 14, respectively), aggressive rats (n = 14, respectively) and rats receiving foot shock (FS; n = 14, respectively). Plasma corticosterone concentration was measured after FS sessions. Leukocyte counts and humoral immunity were evaluated. In neonatal malnourished animals, FS-induced stress reduced plasma corticosterone concentration. Intraspecific aggressiveness induced alterations in leukocyte counts and antibody titers 7 and 15 days after immunization. Neonatal malnourished animals showed no changes in the immune parameters evaluated. Expression of intraspecific aggressiveness activates the immune system. Neonatal malnutrition seems to have a long-lasting effect on components of both neuroendocrine and immune functions.
Loganathan, Sundareswaran; Rathinasamy, Sheeladevi
Noise stress has different effects on memory and novelty and the link between them with an electroencephalogram (EEG) has not yet been reported. To find the effect of sub-acute noise stress on the memory and novelty along with EEG and neurotransmitter changes. Eight-arm maze (EAM) and Y-maze to analyze the memory and novelty by novel object test. Four groups of rats were used: Control, control treated with Scoparia dulcis extract, noise exposed, and noise exposed which received Scoparia extract. The results showed no marked difference observed between control and control treated with Scoparia extract on EAM, Y-maze, novel object test, and EEG in both prefrontal and occipital region, however, noise stress exposed rats showed significant increase in the reference memory and working memory error in EAM and latency delay, triad errors in Y-maze, and prefrontal and occipital EEG frequency rate with the corresponding increase in plasma corticosterone and epinephrine, and significant reduction in the novelty test, and significant reduction in the novelty test, amplitude of prefrontal, occipital EEG, and acetylcholine. These noise stress induced changes in EAM, Y-maze, novel object test, and neurotransmitters were significantly prevented when treated with Scoparia extract and these changes may be due to the normalizing action of Scoparia extract on the brain, which altered due to noise stress. Noise stress exposure causes EEG, behavior, and neurotransmitter alteration in the frontoparietal and occipital regions mainly involved in planning and recognition memoryOnly the noise stress exposed animals showed the significant alteration in the EEG, behavior, and neurotransmittersHowever, these noise stress induced changes in EEG behavior and neurotransmitters were significantly prevented when treated with Scoparia extractThese changes may be due to the normalizing action of Scoparia dulcis (adoptogen) on the brain which altered by noise stress. Abbreviations used: EEG
Morrison, S A; Ainslie, P N; Lucas, R A I; Cheung, S S; Cotter, J D
Whole-body heating increases the likelihood of syncope, whereas utilizing lower-body compression garments may reduce syncope risk. We hypothesized that graded compression garments would reduce the typically observed large postural reductions in arterial blood pressure and middle cerebral artery velocity, in normothermia and especially once passively heat stressed. Fifteen men (age: 27 ± 4 years, aerobic fitness range: 30-75 mL/kg(/) min) completed a supine-to-stand orthostatic challenge for 3 min at normothermia and after passive heating (esophageal temperature, +0.5 °C from baseline) on two occasions (> 7 days): once wearing commercially available compression trousers and once wearing low-compression placebo trousers (randomized order). Blood flow velocity in the middle cerebral artery (transcranial Doppler), mean arterial blood pressure (mean BP: Finometer) and end-tidal carbon dioxide pressure were measured continuously. During normothermia, compression, garments did not alter the magnitude of the postural changes in mean BP or middle cerebral artery velocity. After passive heating, although the magnitudes of these changes were exaggerated, they were not significantly affected by compression garments. Compression garments did not attenuate the initial or sustained orthostatic hypotension associated with posture change, either during normothermia or following passive heat stress. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
.... Despite the importance placed on the family as a source of social support, there have been few systematic studies of the relationships between pilot family life, workplace stress, and performance...
Full Text Available Abstract Background Stress during fetal life increases the risk of affective and immune disorders later in life. The altered peripheral immune response caused by prenatal stress may impact on brain function by the modification of local inflammation. In this study we have explored whether prenatal stress results in alterations in the immune response in the hippocampus of female mice during adult life. Methods Pregnant C57BL/6 mice were subjected three times/day during 45 minutes to restraint stress from gestational Day 12 to delivery. Control non-stressed pregnant mice remained undisturbed. At four months of age, non-stressed and prenatally stressed females were ovariectomized. Fifteen days after surgery, mice received an i.p. injection of vehicle or of 5 mg/kg of lipopolysaccharide (LPS. Mice were sacrificed 20 hours later by decapitation and the brains were removed. Levels of interleukin-1β (IL1β, interleukin-6 (IL-6, tumor necrosis factor α (TNF-α, interferon γ-inducible protein 10 (IP10, and toll-like receptor 4 mRNA were assessed in the hippocampus by quantitative real-time polymerase chain reaction. Iba1 immunoreactivity was assessed by immunocytochemistry. Statistical significance was determined by one-way or two-way analysis of variance. Results Prenatal stress, per se, increased IL1β mRNA levels in the hippocampus, increased the total number of Iba1-immunoreactive microglial cells and increased the proportion of microglial cells with large somas and retracted cellular processes. In addition, prenatally stressed and non-stressed animals showed different responses to peripheral inflammation induced by systemic administration of LPS. LPS induced a significant increase in mRNA levels of IL-6, TNF-α and IP10 in the hippocampus of prenatally stressed mice but not of non-stressed animals. In addition, after LPS treatment, prenatally stressed animals showed a higher proportion of Iba1-immunoreactive cells in the hippocampus with
Aquilino, Mónica; Sánchez-Argüello, Paloma; Martínez-Guitarte, José-Luis
Vinclozolin is a fungicide used in agriculture that can reach aquatic ecosystems and affect the organisms living there. Its effects have been intensively studied in vertebrates, where it acts as an antiandrogen, but there is a lack of information about its mechanistic effects on invertebrates. In this work, we analyzed the response of genes related to the endocrine system, the stress response, and the detoxification mechanisms of Chironomus riparius fourth instar larvae after 24h and 48h exposures to 20 (69.9nM), 200 (699nM), and 2000μg/L (6.99μM) of Vinclozolin. Survival analysis showed that this compound has low toxicity, as it was not lethal for this organism at the concentrations used. However, this fungicide was shown to modify the transcriptional activity of the ecdysone response pathway genes EcR, E74, and Kr-h1 by increasing their mRNA levels. While no changes were observed in disembodied, a gene related with the ecdysone synthesis metabolic pathway, Cyp18A1, which is involved in the inactivation of the active form of ecdysone, was upregulated. Additionally, the expression of two genes related to other hormones, FOXO and MAPR, did not show any changes when Vinclozolin was present. The analysis of stress response genes showed significant changes in the mRNA levels of Hsp70, Hsp24, and Gp93, indicating that Vinclozolin activates the cellular stress mechanisms. Finally, the expressions of the genes Cyp4G and GstD3, which encode enzymes involved in phase I and phase II detoxification, respectively, were analyzed. It was found that their mRNA levels were altered by Vinclozolin, suggesting their involvement in the degradation of this compound. For the first time, these results show evidence that Vinclozolin can modulate gene expression, leading to possible significant endocrine alterations of the insect endocrine system. These results also offer new clues about the mode of action of this compound in invertebrates. Copyright © 2016 Elsevier B.V. All rights
Full Text Available This paper presents an empirical investigation on the effects of occupational stress, psychological stress as well as job burnout on women’s employee performance in city of Karaj, Iran. The proposed study designs a questionnaire in Likert scale and distributes it among all female employees who worked for Bank Maskan in this city. In our survey, employee performance consists of three parts of interpersonal performance, job performance as well as organizational performance. Cronbach alpha has been used to verify the overall questionnaire, all components were within acceptable levels, and the implementation of Kolmogorov-Smirnov test has indicated that the data were not normally distributed. Using Spearman correlation ratio as well as regression techniques, the study has determined that while psychological stress influenced significantly on all three components of employee performance including interpersonal performance, job performance as well as organizational performance, the effect on job performance was greater than the other components. In addition, occupational stress only influences on organizational as well as interpersonal performance. Finally, employee burnout has no impact on any components of employee performance.
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.
Santander, Christian; Aroca, Ricardo; Ruiz-Lozano, Juan Manuel; Olave, Jorge; Cartes, Paula; Borie, Fernando; Cornejo, Pablo
At present, drought and soil salinity are among the most severe environmental stresses that affect the growth of plants through marked reduction of water uptake which lowers water potential, leading to osmotic stress. In general, osmotic stress causes a series of morphological, physiological, biochemical, and molecular changes that affect plant performance. Several studies have found that diverse types of soil microorganisms improve plant growth, especially when plants are under stressful conditions. Most important are the arbuscular mycorrhizal fungi (AMF) which form arbuscular mycorrhizas (AM) with approximately 80% of plant species and are present in almost all terrestrial ecosystems. Beyond the well-known role of AM in improving plant nutrient uptake, the contributions of AM to plants coping with osmotic stress merit analysis. With this review, we describe the principal direct and indirect mechanisms by which AM modify plant responses to osmotic stress, highlighting the role of AM in photosynthetic activity, water use efficiency, osmoprotectant production, antioxidant activities, and gene expression. We also discuss the potential for using AMF to improve plant performance under osmotic stress conditions and the lines of research needed to optimize AM use in plant production.
Roos, Leslie E; Beauchamp, Kathryn G; Giuliano, Ryan; Zalewski, Maureen; Kim, Hyoun K; Fisher, Philip A
Although prior research has characterized stress system reactivity (i.e. hypothalamic-pituitary-adrenal axis, HPAA; autonomic nervous system, ANS) in children, it has yet to examine the extent to which biological reactivity predicts concurrent goal-directed behavior. Here, we employed a stressor paradigm that allowed concurrent assessment of both stress system reactivity and performance on a speeded-response task to investigate the links between biological reactivity and cognitive function under stress. We further investigated gender as a moderator given previous research suggesting that the ANS may be particularly predictive of behavior in males due to gender differences in socialization. In a sociodemographically diverse sample of young children (N = 58, M age = 5.38 yrs; 44% male), individual differences in sociodemographic covariates (age, household income), HPAA (i.e. cortisol), and ANS (i.e. respiratory sinus arrhythmia, RSA, indexing the parasympathetic branch; pre-ejection period, PEP, indexing the sympathetic branch) function were assessed as predictors of cognitive performance under stress. We hypothesized that higher income, older age, and greater cortisol reactivity would be associated with better performance overall, and flexible ANS responsivity (i.e. RSA withdrawal, PEP shortening) would be predictive of performance for males. Overall, females performed better than males. Two-group SEM analyses suggest that, for males, greater RSA withdrawal to the stressor was associated with better performance, while for females, older age, higher income, and greater cortisol reactivity were associated with better performance. Results highlight the relevance of stress system reactivity to cognitive performance under stress. Future research is needed to further elucidate for whom and in what situations biological reactivity predicts goal-directed behavior.
Raymaekers, Linsey H.C.; Otgaar, Henry; Memon, Amina; Waltjen, Thijs T.; Nivo, Maud; Slegers, Chiel; Broers, Nick J.; Smeets, Tom
Abstract In the eyewitness identification literature, stress and arousal at the time of encoding are considered to adversely influence identification performance. This assumption is in contrast with findings from the neurobiology field of learning and memory, showing that stress and stress hormones are critically involved in forming enduring memories. This discrepancy may be related to methodological differences between the two fields of research, such as the tendency for immediate testing or the use of very short (1–2 hours) retention intervals in eyewitness research, while neurobiology studies insert at least 24 hours. Other differences refer to the extent to which stress‐responsive systems (i.e., the hypothalamic–pituitary–adrenal axis) are stimulated effectively under laboratory conditions. The aim of the current study was to conduct an experiment that accounts for the contemporary state of knowledge in both fields. In all, 123 participants witnessed a live staged theft while being exposed to a laboratory stressor that reliably elicits autonomic and glucocorticoid stress responses or while performing a control task. Salivary cortisol levels were measured to control for the effectiveness of the stress induction. One week later, participants attempted to identify the thief from target‐present and target‐absent line‐ups. According to regression and receiver operating characteristic analyses, stress did not have robust detrimental effects on identification performance. Copyright © 2016 John Wiley & Sons, Ltd. © 2016 The Authors Behavioral Sciences & the Law Published by John Wiley & Sons Ltd PMID:27417874
Zhou, Qi Tony; Morton, David A V
For dry powder inhaler formulations, micronized drug powders are commonly mixed with coarse lactose carriers to facilitate powder handling during the manufacturing and powder aerosol delivery during patient use. The performance of such dry powder inhaler formulations strongly depends on the balance of cohesive and adhesive forces experienced by the drug particles under stresses induced in the flow environment during aerosolization. Surface modification with appropriate additives has been proposed as a practical and efficient way to alter the inter-particulate forces, thus potentially controlling the formulation performance, and this strategy has been employed in a number of different ways with varying degrees of success. This paper reviews the main strategies and methodologies published on surface coating of lactose carriers, and considers their effectiveness and impact on the performance of dry powder inhaler formulations. Copyright Â© 2011 Elsevier B.V. All rights reserved.
Haider, Saida; Naqvi, Fizza; Batool, Zehra; Tabassum, Saiqa; Sadir, Sadia; Liaquat, Laraib; Naqvi, Faizan; Zuberi, Nudrat Anwer; Shakeel, Hina; Perveen, Tahira
It is observed that memories are more strengthened in a stressful condition. Studies have also demonstrated an association between stressful events and the onset of depression and anxiety. Considering the nootropic, anxiolytic and antidepressant-like properties of curcumin in various experimental approaches, we appraised the beneficial effects of this herb on acute immobilization stress-induced behavioral and neurochemical alterations. Rats in test group were administrated with curcumin (200mg/kg/day), dissolved in neutral oil, for 1 week. Both control and curcumin-treated rats were divided into unstressed and stressed groups. Rats in the stressed group were subjected to immobilization stress for 2h. After stress, the animals were subjected to behavioral tests. Immobilization stress induced an anxiogenic behavior in rats subjected to elevated plus maze test (EPM). Locomotor activity was also significantly increased following the acute immobilization stress. Pre-administration of curcumin prevented the stress-induced behavioral deficits. Highest memory performance was observed in stressed rats that were pre-treated with curcumin in Morris water maze (MWM). Brain malondialdehyde (MDA) levels, catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), and acetylcholinesterase (AChE) activities were also estimated. Present study suggests a role of antioxidant enzymes in the attenuation of acute stress induced anxiety by curcumin. The findings therefore suggest that supplementation of curcumin may be beneficial in the treatment of acute stress induced anxiety and enhancement of memory function. Copyright © 2015 Elsevier Inc. All rights reserved.
Varlinskaya, Elena I; Truxell, Eric M; Spear, Linda P
In rats, considerable differences in the social consequences of acute ethanol are seen across ontogeny, with adolescents being more sensitive to low dose ethanol-induced social facilitation and less sensitive to the social inhibition evident at higher ethanol doses relative to adults. Stressor exposure induces social anxiety-like behavior, indexed via decreases in social preference, and alters responsiveness to the social consequences of acute ethanol by enhancing ethanol-associated social facilitation and anxiolysis regardless of age. Given that substantial ontogenetic differences in the social consequences of ethanol are evident even within the adolescent period, the present study was designed to investigate whether similar stress-associated alterations in social behavior and ethanol responsiveness are evident in early and late adolescents. Juvenile-early adolescent [postnatal days (P) 24-28] and mid-late adolescent (P38-42) male and female Sprague-Dawley rats were repeatedly restrained (90 min/day) for 5 days, followed by examination of ethanol-induced (0, 0.25, 0.5, or 1.0 g/kg) alterations in social behaviors on the last day. Responsiveness to restraint stress in terms of both stress-induced behavioral alterations and stress-associated changes in sensitivity to the social consequences of acute ethanol challenge differed drastically at the two ages. Repeated restraint increased anxiety-like behavior in a social context in older adolescents, whereas previously stressed young adolescent males showed substantial increases in play fighting - an effect of stress not evident in P28 females or P42 adolescents of either sex. Unexpectedly, repeated restraint eliminated sensitivity to ethanol-induced social facilitation in P28 adolescent males and made their female counterparts less sensitive to this effect. In contrast, previously stressed late adolescents became sensitive to the socially facilitating and anxiolytic effects of acute ethanol. © 2013.
Liu, Guodong; Chen, Yun; Faergeman, Nils J.
, the mutants showed altered resistances to different exogenous stresses regarding the specific growth rate and duration of lag phase. The erg5 deletion mutant whose sterol has a saturated side chain exhibited overall robust growth under the tested stress conditions. The thermotolerant phenotype of erg5......The sterol composition of membranes is known to influence many phenotypes of yeast. However, a systematic study of the relationship between sterol composition and stress resistances has not been conducted. Here, we therefore constructed single or double gene deletion mutants of the last four...
Full Text Available Background: Physical exercise may modify biologic stress responses. Objective: To investigate the impact of exercise training on vascular alterations induced by acute stress, focusing on nitric oxide and cyclooxygenase pathways. Method: Wistar rats were separated into: sedentary, trained (60-min swimming, 5 days/week during 8 weeks, carrying a 5% body-weight load, stressed (2 h-immobilization, and trained/stressed. Response curves for noradrenaline, in the absence and presence of L-NAME or indomethacin, were obtained in intact and denuded aortas (n=7-10. Results: None of the procedures altered the denuded aorta reactivity. Intact aortas from stressed, trained, and trained/stressed rats showed similar reduction in noradrenaline maximal responses (sedentary 3.54±0.15, stressed 2.80±0.10*, trained 2.82±0.11*, trained/stressed 2.97± 0.21*, *P<0.05 relate to sedentary. Endothelium removal and L-NAME abolished this hyporeactivity in all experimental groups, except in trained/stressed rats that showed a partial aorta reactivity recovery in L-NAME presence (L-NAME: sedentary 5.23±0,26#, stressed 5.55±0.38#, trained 5.28±0.30#, trained/stressed 4.42±0.41, #P<0.05 related to trained/stressed. Indomethacin determined a decrease in sensitivity (EC50 in intact aortas of trained rats without abolishing the aortal hyporeactivity in trained, stressed, and trained/stressed rats. Conclusions: Exercise-induced vascular adaptive response involved an increase in endothelial vasodilator prostaglandins and nitric oxide. Stress-induced vascular adaptive response involved an increase in endothelial nitric oxide. Beside the involvement of the endothelial nitric oxide pathway, the vascular response of trained/stressed rats involved an additional mechanism yet to be elucidated. These findings advance on the understanding of the vascular processes after exercise and stress alone and in combination.
Huang, Peng; Zhang, Tengxiao; Miao, Danmin; Zhu, Xia
To examine Chinese soldiers' acute stress responses, we did this study. The soldiers completed the Acute Stress Response Scale (ASRS) when engaged in major tasks, such as earthquake rescue in Wenchuan, Sichuan, and maintaining social stability in Urumchi, Xinjiang. The ASRS has good reliability and validity. The study enrolled 1,832 male soldiers. The results showed significant differences among five dimensions and the overall response index when comparing four diverse military tasks. Further analysis found that reduced work efficiency and 24 symptom clusters were significantly positively correlated. The acute stress response of soldiers performing various tasks was influenced by many factors, including the task characteristics and external factors. In addition, the acute stress response affected their work efficiency.
Full Text Available Abstract Background New Delhi metallo beta-lactamase is known to compromise carbapenem therapy and leading to treatment failure. However, their response to carbapenem stress is not clearly known. Here, we have investigated the transcriptional response of bla NDM-1 and plasmid copy number alteration under carbapenem exposure. Methods Three bla NDM-1 harboring plasmids representing three incompatibility types (IncFIC, IncA/C and IncK were inoculated in LB broth with and without imipenem, meropenem and ertapenem. After each 1 h total RNA was isolated, immediately reverse transcribed into cDNA and quantitative real time PCR was used for transcriptional expression of bla NDM-1. Horizontal transferability and stability of the plasmids encoding bla NDM-1 were also determined. Changes in copy number of bla NDM-1 harboring plasmids under the exposure of different carbapenems were determined by real time PCR. Clonal relatedness among the isolates was determined by pulsed field gel electrophoresis. Results Under carbapenem stress over an interval of time there was a sharp variation in the transcriptional expression of bla NDM-1 although it did not follow a specific pattern. All bla NDM-1 carrying plasmids were transferable by conjugation. These plasmids were highly stable and complete loss was observed between 92nd to 96th serial passages when antibiotic pressure was withdrawn. High copy number of bla NDM-1 was found for IncF type plasmids compared to the other replicon types. Conclusion This study suggests that the single dose of carbapenem pressure does not significantly influence the expression of bla NDM-1 and also focus on the stability of this gene as well as the change in copy number with respect to the incompatible type of plasmid harboring resistance determinant.
Ramadasan-Nair, Renjini; Gayathri, Narayanappa; Mishra, Sudha; Sunitha, Balaraju; Mythri, Rajeswara Babu; Nalini, Atchayaram; Subbannayya, Yashwanth; Harsha, Hindalahalli Chandregowda; Kolthur-Seetharam, Ullas; Bharath, Muchukunte Mukunda Srinivas
Muscular dystrophies (MDs) and inflammatory myopathies (IMs) are debilitating skeletal muscle disorders characterized by common pathological events including myodegeneration and inflammation. However, an experimental model representing both muscle pathologies and displaying most of the distinctive markers has not been characterized. We investigated the cardiotoxin (CTX)-mediated transient acute mouse model of muscle degeneration and compared the cardinal features with human MDs and IMs. The CTX model displayed degeneration, apoptosis, inflammation, loss of sarcolemmal complexes, sarcolemmal disruption, and ultrastructural changes characteristic of human MDs and IMs. Cell death caused by CTX involved calcium influx and mitochondrial damage both in murine C2C12 muscle cells and in mice. Mitochondrial proteomic analysis at the initial phase of degeneration in the model detected lowered expression of 80 mitochondrial proteins including subunits of respiratory complexes, ATP machinery, fatty acid metabolism, and Krebs cycle, which further decreased in expression during the peak degenerative phase. The mass spectrometry (MS) data were supported by enzyme assays, Western blot, and histochemistry. The CTX model also displayed markers of oxidative stress and a lowered glutathione reduced/oxidized ratio (GSH/GSSG) similar to MDs, human myopathies, and neurogenic atrophies. MS analysis identified 6 unique oxidized proteins from Duchenne muscular dystrophy samples (n = 6) (versus controls; n = 6), including two mitochondrial proteins. Interestingly, these mitochondrial proteins were down-regulated in the CTX model thereby linking oxidative stress and mitochondrial dysfunction. We conclude that mitochondrial alterations and oxidative damage significantly contribute to CTX-mediated muscle pathology with implications for human muscle diseases. PMID:24220031
Full Text Available Four hundred and two R&D personnel were surveyed through questionnaires to study the relationship between mental toughness, stress appraisal (including experience of stress and stress control, and innovation performance. The findings reveal a significant negative correlation between mental toughness and stress experience and a significant positive correlation between mental toughness and both stress control and innovation performance. Furthermore, although the experience of stress was negatively correlated with innovation performance, stress control had the opposite effect. Experience of stress and stress control were the mediating variables for mental toughness and innovation performance, respectively. There was also a significant interaction effect between stress appraisal and mental toughness.
Victor, Victor M; Rovira-Llopis, Susana; Saiz-Alarcon, Vanessa; Sangüesa, Maria C; Rojo-Bofill, Luis; Bañuls, Celia; Falcón, Rosa; Castelló, Raquel; Rojo, Luis; Rocha, Milagros; Hernández-Mijares, Antonio
Anorexia nervosa is a common illness among adolescents and is characterised by oxidative stress. The effects of anorexia on mitochondrial function and redox state in leukocytes from anorexic subjects were evaluated. A multi-centre, cross-sectional case-control study was performed. Our study population consisted of 20 anorexic patients and 20 age-matched controls, all of which were Caucasian women. Anthropometric and metabolic parameters were evaluated in the study population. To assess whether anorexia nervosa affects mitochondrial function and redox state in leukocytes of anorexic patients, we measured mitochondrial oxygen consumption, membrane potential, reactive oxygen species production, glutathione levels, mitochondrial mass, and complex I and III activity in polymorphonuclear cells. Mitochondrial function was impaired in the leukocytes of the anorexic patients. This was evident in a decrease in mitochondrial O2 consumption (Panorexic patients (Panorexic patients and is closely related to mitochondrial dysfunction. Our results lead us to propose that the oxidative stress that occurs in anorexia takes place at mitochondrial complex I. Future research concerning mitochondrial dysfunction and oxidative stress should aim to determine the physiological mechanism involved in this effect and the physiological impact of anorexia.
Howison, Ruth A.; Olff, Han; van Puijenbroek, Marinka E. B.; Smit, Christian
The importance of positive plant-plant interactions is generally suggested to increase towards more stressful conditions, due to mutual stress amelioration between plants. Bioturbating macrodetritivores can also ameliorate stress through bioturbation, but can also become selective herbivores under
Howison, Ruth A.; Olff, H.; Puijenbroek, van M.E.B.; Smit, Christian
1.The importance of positive plant–plant interactions is generally suggested to increase towards more stressful conditions, due to mutual stress amelioration between plants. Bioturbating macrodetritivores can also ameliorate stress through bioturbation, but can also become selective herbivores under
Schwaiger, Marion; Grinberg, Marianna; Moser, Dirk; Zang, Johannes C S; Heinrichs, Markus; Hengstler, Jan G; Rahnenführer, Jörg; Cole, Steve; Kumsta, Robert
Exposure to serious or traumatic events early in life can lead to persistent alterations in physiological stress response systems, including enhanced cross talk between the neuroendocrine and immune system. These programming effects may be mechanistically involved in mediating the effects of adverse childhood experience on disease risk in adulthood. We investigated hormonal and genome-wide mRNA expression responses in monocytes to acute stress exposure, in a sample of healthy adults (n=30) with a history of early childhood adversity, and a control group (n=30) without trauma experience. The early adversity group showed altered hypothalamus-pituitary-adrenal axis responses to stress, evidenced by lower ACTH and cortisol responses. Analyses of gene expression patterns showed that stress-responsive transcripts were enriched for genes involved in cytokine activity, cytokine-cytokine receptor interaction, chemokine activity, and G-protein coupled receptor binding. Differences between groups in stress-induced regulation of gene transcription were observed for genes involved in steroid binding, hormone activity, and G-protein coupled receptor binding. Transcription factor binding motif analysis showed an increased activity of pro-inflammatory upstream signaling in the early adversity group. We also identified transcripts that were differentially correlated with stress-induced cortisol increases between the groups, enriched for genes involved in cytokine-cytokine receptor interaction and glutamate receptor signaling. We suggest that childhood adversity leads to persistent alterations in transcriptional control of stress-responsive pathways, which-when chronically or repeatedly activated-might predispose individuals to stress-related psychopathology.
Victor M Victor
Full Text Available CONTEXT: Anorexia nervosa is a common illness among adolescents and is characterised by oxidative stress. OBJECTIVE: The effects of anorexia on mitochondrial function and redox state in leukocytes from anorexic subjects were evaluated. DESIGN AND SETTING: A multi-centre, cross-sectional case-control study was performed. PATIENTS: Our study population consisted of 20 anorexic patients and 20 age-matched controls, all of which were Caucasian women. MAIN OUTCOME MEASURES: Anthropometric and metabolic parameters were evaluated in the study population. To assess whether anorexia nervosa affects mitochondrial function and redox state in leukocytes of anorexic patients, we measured mitochondrial oxygen consumption, membrane potential, reactive oxygen species production, glutathione levels, mitochondrial mass, and complex I and III activity in polymorphonuclear cells. RESULTS: Mitochondrial function was impaired in the leukocytes of the anorexic patients. This was evident in a decrease in mitochondrial O2 consumption (P<0.05, mitochondrial membrane potential (P<0.01 and GSH levels (P<0.05, and an increase in ROS production (P<0.05 with respect to control subjects. Furthermore, a reduction of mitochondrial mass was detected in leukocytes of the anorexic patients (P<0.05, while the activity of mitochondrial complex I (P<0.001, but not that of complex III, was found to be inhibited in the same population. CONCLUSIONS: Oxidative stress is produced in the leukocytes of anorexic patients and is closely related to mitochondrial dysfunction. Our results lead us to propose that the oxidative stress that occurs in anorexia takes place at mitochondrial complex I. Future research concerning mitochondrial dysfunction and oxidative stress should aim to determine the physiological mechanism involved in this effect and the physiological impact of anorexia.
Yucha, Carolyn B; Kowalski, Susan; Cross, Chad
The purpose of this study was to evaluate whether nursing students assigned to a home hospital experience less stress and improved academic performance. Students were assigned to a home hospital clinical placement (n = 78) or a control clinical placement (n = 79). Stress was measured using the Student Nurse Stress Index (SNSI) and Spielberger's State Anxiety Inventory. Academic performance included score on the RN CAT, a standardized mock NCLEX-RN(®)-type test; nursing grade point average; and first attempt pass-fail on the NCLEX-RN. There were no statistically significant differences between the two groups for age, gender, marital status, ethnicity, or score on the nurse entrance examination. There were significant changes in SNSI over time but not between groups. Academic load and state anxiety showed an interaction of time by group, with the home hospital group showing reductions over time, compared with the control group. Copyright 2009, SLACK Incorporated.
Pari, Leelavinothan; Murugavel, Ponnusamy
Cadmium (Cd) is a neurotoxic metal, which induces oxidative stress and membrane disturbances in nerve system. The garlic compound diallyl tetrasulfide (DTS) has the cytoprotective and antioxidant activity against Cd induced toxicity. The present study was carried out to investigate the efficacy of DTS in protecting the Cd induced changes in the activity of acetylcholinesterase (AChE), membrane bound enzymes, lipid peroxidation (LPO) and antioxidant status in the brain of rats. In rats exposed to Cd (3 mg/kg/day subcutaneously) for 3 weeks, a significant (P + K + -ATPase, Mg 2+ -ATPase and Ca 2+ -ATPase) were observed in brain tissue. Oral administration of DTS (40 mg/kg/day) with Cd significantly (P < 0.05) diminished the levels of LPO and protein carbonyls and significantly (P < 0.05) increased the activities of ATPases, antioxidant enzymes, GSH and TSH in brain. These results indicate that DTS attenuate the LPO and alteration of antioxidant and membrane bound enzymes in Cd exposed rats, which suggest that DTS protects the brain function from toxic effects of Cd
Puerto, María; Jos, Angeles; Pichardo, Silvia; Moyano, Rosario; Blanco, Alfonso; Cameán, Ana M
Cylindrospermopsin (CYN) is increasingly recognized as a potential threat to drinking water safety, due to its ubiquity. This cyanotoxin has been found to cause toxic effects in mammals, and although fish could be in contact with this toxin, acute toxicity studies on fish are nonexistent. This is the first study showing that single doses of CYN pure standard (200 or 400 μg CYN/kg fish bw) by oral route (gavage) generate histopathological effects in fish (Tilapia-Oreochromis niloticus) exposed to the toxin under laboratory condition. Among the morphological changes, disorganized parenchymal architecture in the liver, dilated Bowman's space in the kidney, fibrolysis in the heart, necrotic enteritis in the intestines, and hemorrhages in the gills, were observed. Moreover, some oxidative stress biomarkers in the liver and kidney of tilapias were altered. Thus, CYN exposure induced increased protein oxidation products in both organs, NADPH oxidase activity was significantly increased with the kidney being the most affected organ, and decreased GSH contents were also detected in both organs, at the higher dose assayed. Copyright © 2012 Wiley Periodicals, Inc.
Dimri, Umesh; Bandyopadhyay, S; Singh, Shanker Kumar; Ranjan, Rakesh; Mukherjee, R; Yatoo, M I; Patra, P H; De, U K; Dar, A A
The present study aimed to examine the status of antioxidant systems of the pigs naturally suffering from sarcoptic mange. Fifty nine pigs were divided into three groups, healthy control (group I, n=15), subclinical sarcoptic mange (group II, n=22) and clinical sarcoptic mange (group III, n=22). To assess the status of antioxidant systems; lipid peroxides (LPO), reduced glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), ascorbic acid, zinc and copper concentrations in the blood samples as well as LPO, SOD, CAT and glutathione-s-transferase (GST) activities in the skin were measured. The GSH, SOD, GPx, ascorbic acid, zinc, copper concentrations in blood were significantly lower in the pigs suffering from clinical and subclinical sarcoptic mange, when compared with the healthy control. However, LPO content of these infested pigs was significantly higher. The CAT, SOD and GST activities in the skin of the diseased pigs were significantly lower, whereas LPO was significantly higher as compared to the healthy control. From the present study, it may be concluded that sarcoptic mange bestows remarkable alterations in the oxidative stress markers and imposes compromisation of the antioxidant status of the infested pigs. Copyright © 2014 Elsevier B.V. All rights reserved.
Rumambie, Yuliana Fransisca
Employee Performance is an important part in a company or organization. It plays a very important role in an organization because performance of the company or organization largely depends on the performance of its employee. Recently, organizations realize that there are several factors that can affect employee performance. Several factors that can considered as the major determinants of employee performance, such as Performance Appraisal, Reward System, Job Stress, and Work life conflict. Th...
Talib, Nadeem; Zia-ur-Rehman, Muhammad
This study aims to investigate the effect of factor such as perceived stress on the academic performance of the students. A sample of 199 university graduates and undergraduates in Rawalpindi and Islamabad was selected as a statistical frame. Instrumentation used for this study is previously validated construct in order to evaluate the effect of…
The serious breakdown in health of the academics in Nigerian Federal Universities which placed them in chronic dependency on drugs has necessitated this study. The study adopted a descriptive survey approach which ascertained that music performance as therapy would be a vital tool for managing stress amongst the ...
The study assessed the association between work stress factors and employee job performance in a selected manufacturing organisation in Lagos State Nigeria. A total of 350 employees selected through stratified random sampling technique participated in the study. Questionnaire was the main instrument used for data ...
Delahaij, R.; Dam, K. van; Gaillard, A.W.K.; Soeters, J.
This prospective study examined how differences in coping style, coping self-efficacy, and metacognitive awareness influence coping behavior and performance during a realistic acute stressful exercise in 2 military samples (n = 122 and n = 132). Results showed that coping self-efficacy and coping
Badache, Soumeya; Bouslama, Slim; Brahmia, Oualid; Baïri, Abdel Madjid; Tahraoui, Abdel Krim; Ladjama, Ali
We aimed to investigate in adolescent rats the individual and combined effects of prenatal noise and restraint stress on balance control, exploration, locomotion and anxiety behavior. Three groups of pregnant rats were exposed to daily repeated stress from day 11 to day 19 of pregnancy: 3 min noise (Noise Stress, NS); 10 min restraint (restraint stress, RS); or 3 min noise followed by 10 min restraint (mixed stress, MS). On postnatal days (PND) 44, 45 and 46, four groups of male rats (Control, NS, RS:, MS; 16 rats each), were tested as follows: (1) beam walking (BW), (2) open field (OF) and (3) elevated plus maze (EPM). Our results show that the NS group had significantly impaired balance control, locomotion and both horizontal and vertical exploration (p prenatal stressors exert non-additive effects on locomotion, exploration and balance control, but induce greater anxiety through additive effects. Terminal plasma ACTH concentration was increased by prenatal stress, especially noise, which group had the largest adrenal glands. Overall, contrary to expectation, combined prenatal stressors can interact to increase anxiety level, but diminish alteration of exploration, locomotion and impaired balance control, which were strongly induced by noise stress. Lay summary: Experience of stress in pregnancy can have negative effects on the offspring that are long-lasting. Here, we used laboratory rats to see whether repeated episodes of exposure to loud noise or preventing free movement, alone or together, during pregnancy had different effects on behaviors of the adolescent offspring. Using standard tests, we found the prenatal stresses caused the offspring to be anxious, and not to balance when moving around as well as normal offspring; the degree of impairment depended on the type of stress - loud noise exposure had the greatest effects, but if the stresses were combined the effects were not worse. The results point to the need to aim to avoid stress in pregnant
Prabsattroo, Thawatchai; Wattanathorn, Jintanaporn; Iamsaard, Sitthichai; Somsapt, Pichet; Sritragool, Opass; Thukhummee, Wipawee; Muchimapura, Supaporn
Aphrodisiacs are required to improve male sexual function under stressful conditions. Due to the effects of oxidative stress and dopamine on male sexual function, we hypothesized that Moringa oleifera leaves might improve male sexual dysfunction induced by stress. Therefore, the effects on various factors playing important roles in male sexual behavior, such as antioxidant effects, the suppression of monoamine and phosphodiesterase type 5 (PDE-5) activities, serum testosterone and corticosterone levels, and histomorphological changes in the testes, of a hydroethanolic extract of M. oleifera leaves were investigated. Various doses of extract including 10, 50, and 250 mg/kg body weight (BW) were given orally to male Wistar rats before exposure to 12 h-immobilization stress for 7 d. The results demonstrated that the extract showed both antioxidant and monoamine oxidase type B (MAO-B) suppression activities. At 7 d of treatment, the low dose of extract improved sexual performance in stress-exposed rats by decreasing intromission latency and increasing intromission frequency. It also suppressed PDE-5 activity, decreased serum corticosterone level, but increased serum testosterone, numbers of interstitial cells of Leydig and spermatozoa. The increased numbers of interstitial cells of Leydig and spermatozoa might have been due to the antioxidant effect of the extract. The increased sexual performance during the intromission phase might have been due to the suppression of MAO-B and PDE-5 activities and increased testosterone. Therefore, M. oleifera is a potential aphrodisiac, but further research concerning the precise underlying mechanisms is still needed.
Prabsattroo, Thawatchai; Wattanathorn, Jintanaporn; Iamsaard, Sitthichai; Somsapt, Pichet; Sritragool, Opass; Thukhummee, Wipawee; Muchimapura, Supaporn
Aphrodisiacs are required to improve male sexual function under stressful conditions. Due to the effects of oxidative stress and dopamine on male sexual function, we hypothesized that Moringa oleifera leaves might improve male sexual dysfunction induced by stress. Therefore, the effects on various factors playing important roles in male sexual behavior, such as antioxidant effects, the suppression of monoamine and phosphodiesterase type 5 (PDE-5) activities, serum testosterone and corticosterone levels, and histomorphological changes in the testes, of a hydroethanolic extract of M. oleifera leaves were investigated. Various doses of extract including 10, 50, and 250 mg/kg body weight (BW) were given orally to male Wistar rats before exposure to 12 h-immobilization stress for 7 d. The results demonstrated that the extract showed both antioxidant and monoamine oxidase type B (MAO-B) suppression activities. At 7 d of treatment, the low dose of extract improved sexual performance in stress-exposed rats by decreasing intromission latency and increasing intromission frequency. It also suppressed PDE-5 activity, decreased serum corticosterone level, but increased serum testosterone, numbers of interstitial cells of Leydig and spermatozoa. The increased numbers of interstitial cells of Leydig and spermatozoa might have been due to the antioxidant effect of the extract. The increased sexual performance during the intromission phase might have been due to the suppression of MAO-B and PDE-5 activities and increased testosterone. Therefore, M. oleifera is a potential aphrodisiac, but further research concerning the precise underlying mechanisms is still needed. PMID:25743119
Zhang, Xiao-Dong; Yin, Yan; Hu, Xiao-Lei; Duan, Lian; Qi, Rongfeng; Xu, Qiang; Lu, Guang-Ming; Li, Ling-Jiang
The neural substrates of posttraumatic stress disorder (PTSD) are still not fully elucidated. Hence, this study is to explore topological alterations of the default mode network (DMN) in victims with PTSD after a magnitude of 8.0 earthquake using resting-state functional magnetic resonance imaging (rs-fMRI).This study was approved by the local ethical review board, and all participants signed written informed consent. Sixty-two PTSD victims from the 2008 Sichuan earthquake and 62 matched exposed controls underwent rs-fMRI. PTSD was diagnosed by Clinician-Administered PTSD Scale, and underwent PTSD Checklist-Civilian Version for symptom scoring. The DMN was analyzed by using graph theoretical approaches. Further, Pearson correlation analysis was performed to correlate neuroimaging metrics to neuropsychological scores in victims with PTSD.Victims with PTSD showed decreased DMN functional connectivity strength between the right superior frontal gyrus and left inferior parietal lobule (IPL), and showed increased functional connectivity between the right IPL and precuneus or left posterior cingulate cortex. It was also found that victims with PTSD exhibited decreased nodal efficiency in right superior frontal gyrus and precuneus, and increased nodal efficiency in right hippocampus/parahippocampus. Apart from that, PTSD showed higher nodal degree in bilateral hippocampus/parahippocampus. In addition, the functional connectivity strength between the right IPL and precuneus correlated negatively to the avoid scores (r = -0.26, P = .04).This study implicates alteration of topological features on the DMN in PTSD victims after major earthquake, and provides new insights into DMN malfunction in PTSD based on graph theory.
Peters, Eva M J; Müller, Yvonne; Snaga, Wenke; Fliege, Herbert; Reißhauer, Anett; Schmidt-Rose, Thomas; Max, Heiner; Schweiger, Dorothea; Rose, Matthias; Kruse, Johannes
Mouse models show that experimental stress mimicking prolonged life-stress exposure enhances neurogenic inflammation, induces adaptive immunity cytokine-imbalance characterized by a shift to Type 1 T-helper cell cytokines and increases apoptosis of epithelial cells. This affects hair growth in otherwise healthy animals. In this study, we investigate whether a prolonged naturalistic life-stress exposure affects cytokine balance and hair parameters in healthy humans. 33 (18 exam, 15 comparison) female medical students with comparable sociobiological status were analyzed during a stressful final examination period, at three points in time (T) 12 weeks apart. T1 was before start of the learning period, T2 between the three-day written exam and an oral examination, and T3 after a 12 week rest and recovery from the stress of the examination period. Assessments included: self-reported distress and coping strategies (Perceived Stress Questionnaire [PSQ], Trier Inventory for the Assessment of Chronic Stress [TICS]), COPE), cytokines in supernatants of stimulated peripheral blood mononucleocytes (PBMCs), and trichogram (hair cycle and pigmentation analysis). Comparison between students participating in the final medical exam at T2 and non-exam students, revealed significantly higher stress perception in exam students. Time-wise comparison revealed that stress level, TH1/TH2 cytokine balance and hair parameters changed significantly from T1 to T2 in the exam group, but not the control. However, no group differences were found for cytokine balance or hair parameters at T2. The study concludes that in humans, naturalistic stress, as perceived during participation in a major medical exam, has the potential to shift the immune response to TH1 and transiently hamper hair growth, but these changes stay within a physiological range. Findings are instructive for patients suffering from hair loss in times of high stress. Replication in larger and more diverse sample populations is
Eva M J Peters
Full Text Available Mouse models show that experimental stress mimicking prolonged life-stress exposure enhances neurogenic inflammation, induces adaptive immunity cytokine-imbalance characterized by a shift to Type 1 T-helper cell cytokines and increases apoptosis of epithelial cells. This affects hair growth in otherwise healthy animals. In this study, we investigate whether a prolonged naturalistic life-stress exposure affects cytokine balance and hair parameters in healthy humans. 33 (18 exam, 15 comparison female medical students with comparable sociobiological status were analyzed during a stressful final examination period, at three points in time (T 12 weeks apart. T1 was before start of the learning period, T2 between the three-day written exam and an oral examination, and T3 after a 12 week rest and recovery from the stress of the examination period. Assessments included: self-reported distress and coping strategies (Perceived Stress Questionnaire [PSQ], Trier Inventory for the Assessment of Chronic Stress [TICS], COPE, cytokines in supernatants of stimulated peripheral blood mononucleocytes (PBMCs, and trichogram (hair cycle and pigmentation analysis. Comparison between students participating in the final medical exam at T2 and non-exam students, revealed significantly higher stress perception in exam students. Time-wise comparison revealed that stress level, TH1/TH2 cytokine balance and hair parameters changed significantly from T1 to T2 in the exam group, but not the control. However, no group differences were found for cytokine balance or hair parameters at T2. The study concludes that in humans, naturalistic stress, as perceived during participation in a major medical exam, has the potential to shift the immune response to TH1 and transiently hamper hair growth, but these changes stay within a physiological range. Findings are instructive for patients suffering from hair loss in times of high stress. Replication in larger and more diverse sample
Prakash Atish K
Full Text Available Abstract Background A stressful stimulus is a crucial determinant of health and disease. Antidepressants are used to manage stress and their related effects. The present study was designed to investigate the effect of St. John's Wort (Hypericum perforatum in restraint stress-induced behavioral and biochemical alterations in mice. Methods Animals were immobilized for a period of 6 hr. St. John's Wort (50 and 100 mg/kg was administered 30 minutes before the animals were subjecting to acute immobilized stress. Various behavioral tests parameters for anxiety, locomotor activity and nociceptive threshold were assessed followed by biochemical assessments (malondialdehyde level, glutathione, catalase, nitrite and protein subsequently. Results 6-hr acute restraint stress caused severe anxiety like behavior, antinociception and impaired locomotor activity as compared to unstressed animals. Biochemical analyses revealed an increase in malondialdehyde, nitrites concentration, depletion of reduced glutathione and catalase activity as compared to unstressed animal brain. Five days St. John's Wort treatment in a dose of 50 mg/kg and 100 mg/kg significantly attenuated restraint stress-induced behavioral (improved locomotor activity, reduced tail flick latency and antianxiety like effect and oxidative damage as compared to control (restraint stress. Conclusion Present study highlights the modest activity of St. John's Wort against acute restraint stress induced modification.
Tariq Waseem Chohan
Full Text Available Schizophrenia is thought to arise due to a complex interaction between genetic and environmental factors during early neurodevelopment. We have recently shown that partial genetic deletion of the schizophrenia susceptibility gene neuregulin 1 (Nrg1 and adolescent stress interact to disturb sensorimotor gating, neuroendocrine activity and dendritic morphology in mice. Both stress and Nrg1 may have converging effects upon N-methyl-D-aspartate receptors (NMDARs which are implicated in the pathogenesis of schizophrenia, sensorimotor gating and dendritic spine plasticity. Using an identical repeated restraint stress paradigm to our previous study, here we determined NMDAR binding across various brain regions in adolescent Nrg1 heterozygous (HET and wild-type (WT mice using [3H] MK-801 autoradiography. Repeated restraint stress increased NMDAR binding in the ventral part of the lateral septum (LSV and the dentate gyrus (DG of the hippocampus irrespective of genotype. Partial genetic deletion of Nrg1 interacted with adolescent stress to promote an altered pattern of NMDAR binding in the infralimbic (IL subregion of the medial prefrontal cortex. In the IL, whilst stress tended to increase NMDAR binding in WT mice, it decreased binding in Nrg1 HET mice. However in the DG, stress selectively increased the expression of NMDAR binding in Nrg1 HET mice but not WT mice. These results demonstrate a Nrg1-stress interaction during adolescence on NMDAR binding in the medial prefrontal cortex.
Heloisa Aparecida Barbosa Silva Pereira
Full Text Available Here, we evaluated the relationship of diet and F-induced oxidative stress to lipid metabolism in the liver of rats eating normocaloric or hypercaloric diets for two time periods (20 or 60 days.Seventy-two 21-day-old Wistar rats were divided into 2 groups (n = 36 based on the type of diet they were eating; each of these groups was then further divided into another two groups (n = 18 based on the time periods of either 20 or 60 days, for a total of four groups. Each of these was divided into 3 subgroups (n = 6 animals/subgroup, dependent on the dose of F administered in the drinking water (0 mg/L(control, 15 mg/L or 50 mg/L. After the experimental period, blood samples and the liver were collected. Plasma samples were analyzed for HDL, cholesterol and triglycerides. Western blots were performed to probe for GRP78, Erp29, SOD2, Apo-E and SREBP in hepatic tissues.As expected,the expression of target proteins involved in oxidative stress increased in the F-treated groups, especially in liver tissue obtained from animals eating a hypercaloric diet. Most changes in the lipid levels and pathological conditions were seen earlier in the time period, at day 20. The morphometric analyses showed a reduction in steatosis in groups on ahypercaloric diet and treated with 50 mg F/L compared to the control, while no changes were obtained in normocaloric-fed rats. Accordingly, plasma TG was reduced in the F-treated group. The reduced expression of Apo-E in a time- and diet-dependent pattern may account for the particular decrease in steatosis in hypercaloric-fed F-treated rats.These results suggest that F changes liver lipid homeostasis, possibly because of the induction of oxidative stress, which seems to be higher in animals fed hypercaloric diets.
Tatli, Ozge; Sogutmaz Ozdemir, Bahar; Dinler Doganay, Gizem
For the first time, a comprehensive proteome analysis was conducted on Brachypodium leaves under drought stress. Gradual changes in response to drought stress were monitored. Drought is one of the major stress factors that dramatically affect the agricultural productivity worldwide. Improving the yield under drought is an urgent challenge in agriculture. Brachypodium distachyon is a model species for monocot plants such as wheat, barley and several potential biofuel grasses. In the current study, a comprehensive proteome analysis was conducted on Brachypodium leaves under different levels of drought application. To screen gradual changes upon drought, Brachypodium leaves subjected to drought for 4, 8 and 12 days were collected for each treatment day and relative water content of the leaves was measured for each time point. Cellular responses of Brachypodium were investigated through a proteomic approach involving two dimensional difference gel electrophoresis (2D-DIGE) and mass spectrometry (MS). Among 497 distinct spots in Brachypodium protein repertoire, a total of 13 differentially expressed proteins (DEPs) were identified as responsive to drought by mass spectrometry and classified according to their functions using bioinformatics tools. The biological functions of DEPs included roles in photosynthesis, protein folding, antioxidant mechanism and metabolic processes, which responded differentially at each time point of drought treatment. To examine further transcriptional expression of the genes that code identified protein, quantitative real time PCR (qRT-PCR) was performed. Identified proteins will contribute to the studies involving development of drought-resistant crop species and lead to the delineation of molecular mechanisms in drought response.
El-Terras, Adel; Soliman, Mohamed Mohamed; Alkhedaide, Adel; Attia, Hossam Fouad; Alharthy, Abdullah; Banaja, Abdel Elah
In Saudi Arabia, the consumption of carbonated soft drinks is common and often occurs with each meal. Carbonated soft drink consumption has been shown to exhibit effects on the liver, kidney and bone. However, the effects of these soft drinks on brain activity have not been widely examined, particularly at the gene level. Therefore, the current study was conducted with the aim of evaluating the effects of chronic carbonated soft drink consumption on oxidative stress, brain gene biomarkers associated with aggression and brain histology. In total, 40 male Wistar rats were divided into four groups: Group 1 served as a control and was provided access to food and water ad libitum; and groups 2‑4 were given free access to food and carbonated soft drinks only (Cola for group 2, Pepsi for group 3 and 7‑UP for group 4). Animals were maintained on these diets for 3 consecutive months. Upon completion of the experimental period, animals were sacrificed and serological and histopathological analyses were performed on blood and tissues samples. Reverse transcription‑polymerase chain reaction was used to analyze alterations in gene expression levels. Results revealed that carbonated soft drinks increased the serum levels of malondialdehyde (MDA). Carbonated soft drinks were also observed to downregulate the expression of antioxidants glutathione reductase (GR), catalase and glutathione peroxidase (GPx) in the brain when compared with that in the control rats. Rats administered carbonated soft drinks also exhibited decreased monoamine oxidase A (MAO‑A) and acetylcholine esterase (AChE) serum and mRNA levels in the brain. In addition, soft drink consumption upregulated mRNA expression of dopamine D2 receptor (DD2R), while 5-hydroxytryptamine transporter (5‑HTT) expression was decreased. However, following histological examination, all rats had a normal brain structure. The results of this study demonstrated that that carbonated soft drinks induced oxidative stress and
Jenewein, Josef; Erni, Jeannine; Moergeli, Hanspeter; Grillon, Christian; Schumacher, Sonja; Mueller-Pfeiffer, Christoph; Hassanpour, Katayun; Seiler, Annina; Wittmann, Lutz; Schnyder, Ulrich; Hasler, Gregor
There is growing evidence that fear-learning abnormalities are involved in the development of posttraumatic stress disorder (PTSD) and chronic pain. More than 50% of PTSD patients suffer from chronic pain. This study aimed to examine the role of fear-learning deficits in the link between pain perception and PTSD. We included 19 subjects with PTSD and 21 age- and sex-matched healthy control subjects in a fear-conditioning experiment. The conditioned stimulus (CS) consisted of visual signs flashed upon a screen in front of each subject. The unconditioned stimulus was either a low or high temperature impulse delivered through a thermal contact thermode on the subjects' hand. A designation of 'CS-' was assigned to CS always followed by nonpainful low-temperature stimuli; a designation of 'CS+' was given to CS that were randomly followed by either a low or a more painful high temperature. Skin conductance was used as a physiological marker of fear. In healthy control subjects, CS+ induced more fear than CS-, and a low-temperature stimulus induced less subjective pain after CS- than after CS+. PTSD subjects failed to demonstrate such adaptive conditioning. Fear ratings after CS presentation were significantly higher in the PTSD group than in the control group. There were significant interaction effects between group and the type of CS on fear and pain ratings. Fear-learning deficits are a potentially promising, specific psychopathological factor in altered pain perception associated with PTSD. Deficits in safety learning may increase fear and, consequently, pain sensations. These findings may contribute to elucidating the pathogenesis behind the highly prevalent comorbidity that exists between PTSD and pain disorders, and to developing new treatments. This study provides new insights into the pathogenesis of chronic pain in patients with PTSD. The findings may help to develop new treatment strategies for this highly prevalent comorbidity in PTSD. Copyright Â© 2016
Parolini, Marco; De Felice, Beatrice; Ferrario, Claudia; Salgueiro-González, Noelia; Castiglioni, Sara; Finizio, Antonio; Tremolada, Paolo
Several monitoring studies have shown that benzoylecgonine (BE) is the main illicit drug residue commonly measured in the aquatic system worldwide. Few studies have investigated the potential toxicity of this molecule towards invertebrate and vertebrate aquatic non-target organisms focusing on effects at low levels of the biological organization, but no one has assessed the consequences at higher ones. Thus, the present study was aimed at investigating the toxicity of a 48-h exposure to two concentrations of BE, similar to those found in aquatic ecosystems (0.5 μg/L and 1.0 μg/L), on the cladoceran Daphnia magna at different levels of the ecological hierarchy. We relied on a multi-level approach focusing on the effects at biochemical/biomolecular (biomarkers), individual (swimming activity) and population (reproduction) levels. We measured the amount of reactive oxygen species and of the activity of antioxidant (SOD, CAT, and GPx) and detoxifying (GST) enzymes to assess if BE exposure can alter the oxidative status of D. magna specimens, while the lipid peroxidation (TBARS) was measured as a marker of oxidative damage. Moreover, we also measured the acetylcholinesterase (AChE) activity because it is strictly related to behavioral changes in aquatic organisms. Changes in swimming behavior were investigated by a video tracking analysis, while the consequences on reproduction were assessed by a chronic toxicity test. Our results showed that BE concentrations similar to those found in aquatic ecosystems induced oxidative stress and inhibited AChE activity, affecting swimming behavior and the reproduction of Daphnia magna individuals. Copyright © 2017 Elsevier Ltd. All rights reserved.
Lakehayli, S; Said, N; El Khachibi, M; El Ouahli, M; Nadifi, S; Hakkou, F; Tazi, A
Early-life events have long-term effects on brain structures and cause behavioral alterations that persist into adulthood. The present experiments were designed to investigate the effects of prenatal stress on diazepam-induced withdrawal syndrome and serotonin-1A (5HT1A) receptor expression in the raphe nuclei of adult offspring. The results of the present study reveal that maternal exposure to chronic footshock stress increased the anxiety-like behavior in the prenatally stressed (PS) animals withdrawn from chronic diazepam (2.5mg/kg/day i.p for 1week). Moreover, prenatal stress induced a down-regulation of 5HT1A mRNA in the raphe nuclei of adult offspring. To our knowledge, this study is the first to demonstrate that maternal exposure to chronic footshock stress enhances diazepam withdrawal symptoms and alters 5HT1A receptor gene expression in the raphe nuclei of adult offspring. Thus, more studies are needed to clarify the mechanisms underlying the decrease of 5HT1A receptors expression in the raphe nuclei of PS rats. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.
Kelly M. Moench
Full Text Available Dysfunction in corticolimbic circuits that mediate the extinction of learned fear responses is thought to underlie the perseveration of fear in stress-related psychopathologies, including post-traumatic stress disorder. Chronic stress produces dendritic hypertrophy in basolateral amygdala (BLA and dendritic hypotrophy in medial prefrontal cortex, whereas acute stress leads to hypotrophy in both BLA and prelimbic cortex. Additionally, both chronic and acute stress impair extinction retrieval. Here, we examined the effects of a single elevated platform stress on extinction learning and dendritic morphology in infralimbic cortex, a region considered to be critical for extinction. Acute stress produced resistance to extinction, as well as dendritic retraction in infralimbic cortex. Spine density on apical and basilar terminal branches was unaffected by stress. However, animals that underwent conditioning and extinction had decreased spine density on apical terminal branches. Thus, whereas dendritic morphology in infralimbic cortex appears to be particularly sensitive to stress, changes in spines may more sensitively reflect learning. Further, in stressed rats that underwent conditioning and extinction, the level of extinction learning was correlated with spine densities, in that rats with poorer extinction retrieval had more immature spines and fewer thin spines than rats with better extinction retrieval, suggesting that stress may have impaired learning-related spine plasticity. These results may have implications for understanding the role of medial prefrontal cortex in learning deficits associated with stress-related pathologies.
Jaggar, Minal; Weisstaub, Noelia; Gingrich, Jay A; Vaidya, Vidita A
Chronic stress enhances risk for psychiatric disorders, and in animal models is known to evoke depression-like behavior accompanied by perturbed neurohormonal, metabolic, neuroarchitectural and transcriptional changes. Serotonergic neurotransmission, including serotonin 2A (5-HT 2A ) receptors, have been implicated in mediating specific aspects of stress-induced responses. Here we investigated the influence of chronic unpredictable stress (CUS) on depression-like behavior, serum metabolic measures, and gene expression in stress-associated neurocircuitry of the prefrontal cortex (PFC) and hippocampus in 5-HT 2A receptor knockout (5-[Formula: see text]) and wild-type mice of both sexes. While 5-[Formula: see text] male and female mice exhibited a baseline reduced anxiety-like state, this did not alter the onset or severity of behavioral despair during and at the cessation of CUS, indicating that these mice can develop stress-evoked depressive behavior. Analysis of metabolic parameters in serum revealed a CUS-evoked dyslipidemia, which was abrogated in 5-[Formula: see text] female mice with a hyperlipidemic baseline phenotype. 5-[Formula: see text] male mice in contrast did not exhibit such a baseline shift in their serum lipid profile. Specific stress-responsive genes ( Crh , Crhr1 , Nr3c1, and Nr3c2 ), trophic factors ( Bdnf , Igf1 ) and immediate early genes (IEGs) ( Arc , Fos , Fosb , Egr1-4 ) in the PFC and hippocampus were altered in 5-[Formula: see text] mice both under baseline and CUS conditions. Our results support a role for the 5-HT 2A receptor in specific metabolic and transcriptional, but not behavioral, consequences of CUS, and highlight that the contribution of the 5-HT 2A receptor to stress-evoked changes is sexually dimorphic.
Mary C Vázquez
Full Text Available BACKGROUND: Niemann-Pick type C disease (NPC is a neurovisceral lipid storage disorder mainly characterized by unesterified cholesterol accumulation in lysosomal/late endosomal compartments, although there is also an important storage for several other kind of lipids. The main tissues affected by the disease are the liver and the cerebellum. Oxidative stress has been described in various NPC cells and tissues, such as liver and cerebellum. Although considerable alterations occur in the liver, the pathological mechanisms involved in hepatocyte damage and death have not been clearly defined. Here, we assessed hepatic tissue integrity, biochemical and oxidative stress parameters of wild-type control (Npc1(+/+; WT and homozygous-mutant (Npc1(-/-; NPC mice. In addition, the mRNA abundance of genes encoding proteins associated with oxidative stress, copper metabolism, fibrosis, inflammation and cholesterol metabolism were analyzed in livers and cerebella of WT and NPC mice. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed various oxidative stress parameters in the liver and hepatic and cerebellum gene expression in 7-week-old NPC1-deficient mice compared with control animals. We found signs of inflammation and fibrosis in NPC livers upon histological examination. These signs were correlated with increased levels of carbonylated proteins, diminished total glutathione content and significantly increased total copper levels in liver tissue. Finally, we analyzed liver and cerebellum gene expression patterns by qPCR and microarray assays. We found a correlation between fibrotic tissue and differential expression of hepatic as well as cerebellar genes associated with oxidative stress, fibrosis and inflammation in NPC mice. CONCLUSIONS/SIGNIFICANCE: In NPC mice, liver disease is characterized by an increase in fibrosis and in markers associated with oxidative stress. NPC is also correlated with altered gene expression, mainly of genes involved in oxidative stress
Distler, Mijal J; Jungblut, Lucas D; Ceballos, Nora R; Paz, Dante A; Pozzi, Andrea G
Exposure to adverse environmental conditions can elicit a stress response, which results in an increase in endogenous corticosterone levels. In early life stages, it has been thoroughly demonstrated that amphibian larval growth and development is altered as a consequence of chronic stress by interfering with the metamorphic process, however, the underlying mechanisms involved have only been partially disentangled. We examined the effect of intraspecific competition on corticosterone levels during larval development of the toad Rhinella arenarum and its ultimate effects on cell proliferation in particular brain areas as well as the pituitary gland. While overcrowding altered the number of proliferating cells in the pituitary gland, hypothalamus, and third ventricle of the brain, no differences were observed in areas which are less associated with neuroendocrine processes, such as the first ventricle of the brain. Apoptosis was increased in hypothalamic regions but not in the pituitary. With regards to pituitary cell populations, thyrotrophs but not somatoatrophs and corticotrophs showed a decrease in the cell number in overcrowded larvae. Our study shows that alterations in growth and development, produced by stress, results from an imbalance in the neuroendocrine systems implicated in orchestrating the timing of metamorphosis. © 2016 Wiley Periodicals, Inc.
Kim, Yong-Ku; Won, Eunsoo
Major depressive disorder (MDD) is a condition which has often been associated with chronic stress. The sympathetic nervous system is continuously activated without the normal counteraction of the parasympathetic nervous system under the influence of chronic stress. As a result, epinephrine and norepinephrine levels are increased, and acetylcholine levels are decreased, which in turn can increase the levels of pro-inflammatory cytokines. Peripheral inflammatory responses can access the brain, with neuroinflammation contributing to the increase in neurotoxic kynurenine pathway metabolites such as 3-hydroxykynurenine, 3-hydroxyanthranilic acid and quinolinic acid, and decrease in neuroprotective metabolites such as kynurenic acid. Pro-inflammatory cytokines can also exert direct neurotoxic effects on specific brain regions. Previous imaging studies have reported associations between pro-inflammatory states and alterations in brain regions involved in emotional regulation, including the hippocampus, amygdala and anterior cingulate cortex. Alterations in structure and function of such brain areas due to the neurotoxic effects of increased inflammation may be associated with the pathophysiology of depression. This review focuses the influence of stress on neuroinflammation which may cause alterations in brain structure and function in MDD. Copyright © 2017. Published by Elsevier B.V.
Nippert, Angela H; Smith, Aynsley M
Injury rates are high among children and adolescent athletes. Psychosocial stressors, such as personality, history of stressors, and life event stress can influence injury occurrence. After injury, those same factors plus athletic identity, self-esteem, and significant others-such as parents, coaches, and teammates-can affect injury response, recovery and subsequent sport performance. Goal setting, positive self-talk, attribution theory, and relaxation or mental imagery are psychologic interventions that can help injured athletes cope with psychosocial stressors. Medical professionals should be aware of the potential influence that psychosocial stressors and psychologic interventions can have on injury occurrence, injury recovery, and sport performance.
Liu, Xin; Dornbos, David; Pu, Yuehua; Leng, Xinyi; Song, Ligang; Jia, Baixue; Pan, Yuesong; Wang, David; Miao, Zhongrong; Wang, Yilong; Liu, Liping; Wang, Yongjun
Fractional flow reserve (FFR) accurately predicts the degree of stenosis and is now widely used to identify clinically significant severe coronary artery lesions. In the current study, we utilized a similar indicator, fractional flow (FF), to determine the hemodynamic impact of symptomatic intracranial atherosclerotic stenosis (ICAS) and to assess the correlation of FF with the severity of stenosis and collateral circulation. Patients with symptomatic ICAS (70-99% stenosis) confirmed on digital subtraction angiography (DSA) were consecutively recruited. FF was obtained during DSA examination with the use of pressure sensors and was measured as a ratio, comparing measurements distal to an ICAS lesion (Pd) and within the aorta (Pa). The degree of leptomeningeal collateralization was graded from zero (absent) to four (complete compensatory). The correlation between FF, anatomical stenosis, and collateral status was then analyzed. Twenty-five patients with a mean age of 55.6 years were analyzed. The median percentage of stenosis and median FF were 82.3 and 0.68%, respectively. Eleven patients were found to have poor collateralization (grade 0-2), and fourteen patients were identified with good collateral circulation (grade 3-4). Overall, the hemodynamic impact of an atherosclerotic lesions worsened (decreased FF) as the percentage of stenosis increased, although this did not reach statistical significance (r = -0.398, p = 0.06). However, the status of collateralization significantly altered this correlation, worsening the hemodynamic impact in patients with poor collateral circulation (r = -0.677, p = 0.032). There was no difference in patients with good collateral circulation (r = -0.279, p = 0.356). An anatomically severe (70-99%) symptomatic ICAS lesion may generate significant hemodynamic stress downstream as assessed by the indicator FF, particularly in patients with poor collateral circulation. Further, good collateralization may mitigate this
Marais, Thomas L Des; Kluz, Thomas; Xu, Dazhong; Zhang, Xiaoru; Gesumaria, Lisa; Matsui, Mary S; Costa, Max; Sun, Hong
Ultraviolet radiation (UVR) from sunlight is the major effector for skin aging and carcinogenesis. However, genes and pathways altered by solar-simulated UVR (ssUVR), a mixture of UVA and UVB, are not well characterized. Here we report global changes in gene expression as well as associated pathways and upstream transcription factors in human keratinocytes exposed to ssUVR. Human HaCaT keratinocytes were exposed to either a single dose or 5 repetitive doses of ssUVR. Comprehensive analyses of gene expression profiles as well as functional annotation were performed at 24 hours post irradiation. Our results revealed that ssUVR modulated genes with diverse cellular functions changed in a dose-dependent manner. Gene expression in cells exposed to a single dose of ssUVR differed significantly from those that underwent repetitive exposures. While single ssUVR caused a significant inhibition in genes involved in cell cycle progression, especially G2/M checkpoint and mitotic regulation, repetitive ssUVR led to extensive changes in genes related to cell signaling and metabolism. We have also identified a panel of ssUVR target genes that exhibited persistent changes in gene expression even at 1 week after irradiation. These results revealed a complex network of transcriptional regulators and pathways that orchestrate the cellular response to ssUVR.
Liu, Yiting; Neely, Elizabeth; Simmons, Zachary; Connor, James R
The ability to respond to perturbations in endoplasmic reticulum (ER) function is a critical property for all cells. In the presence of chronic ER stress, the cell must adapt so that cell survival is favored or the stress may promote apoptosis. In some pathological processes, such as neurodengeneration, persistent ER stress can be tolerated for an extended period, but eventually cell death occurs. It is not known how an adaptive response converts from survival into apoptosis. To gain a better understanding of the role of adaptive ER stress in neurodegeneration, in this study, with a neuronal cell line SH-SY5Y and primary motor neuron-glia cell mixed cultures, we induced adaptive ER stress and modified the extracellular environment with physiologically relevant changes that alone did not activate ER stress. Our data demonstrate that an adaptive ER stress favored neuronal cell survival, but when cells were exposed to additional physiological insults the level of ER stress was increased, followed by activation of the caspase pathway. Our results indicate that an adaptive ER stress response could be converted to apoptosis when the external cellular milieu changed, suggesting that the conversion from prosurvival to proapoptotic pathways can be driven by the external milieu. This conversion was due at least partially to an increased level of ER stress. © 2015 Wiley Periodicals, Inc.
Full Text Available Since the recognition of asthma as a syndrome with complex pathophysiological signs and symptoms, recent research has sought to classify asthma phenotypes based on its clinical and molecular pathological features. Psychological stress was first recognized as a potential immune system modulator of asthma at the end of the 19th century. The activation of the central nervous system (CNS upon exposure to psychological stress is integral for the initiation of signal transduction processes. The stress hormones, including glucocorticoids, epinephrine, and norepinephrine, which are secreted following CNS activation, are involved in the immunological alterations involved in psychological stress-induced asthma exacerbation. The mechanisms underlying this process may involve a pathological series of events from the brain to the lungs, which is attracting attention as a conceptually advanced phenotype in asthma pathogenesis. This review presents insights into the critical role of psychological stress in the development and exacerbation of allergic asthma, with a special focus on our own data that emphasizes on the continuity from the central sensing of psychological stress to enhanced eosinophilic airway inflammation.
Since the recognition of asthma as a syndrome with complex pathophysiological signs and symptoms, recent research has sought to classify asthma phenotypes based on its clinical and molecular pathological features. Psychological stress was first recognized as a potential immune system modulator of asthma at the end of the 19th century. The activation of the central nervous system (CNS) upon exposure to psychological stress is integral for the initiation of signal transduction processes. The stress hormones, including glucocorticoids, epinephrine, and norepinephrine, which are secreted following CNS activation, are involved in the immunological alterations involved in psychological stress-induced asthma exacerbation. The mechanisms underlying this process may involve a pathological series of events from the brain to the lungs, which is attracting attention as a conceptually advanced phenotype in asthma pathogenesis. This review presents insights into the critical role of psychological stress in the development and exacerbation of allergic asthma, with a special focus on our own data that emphasizes on the continuity from the central sensing of psychological stress to enhanced eosinophilic airway inflammation. Copyright © 2017 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.
Full Text Available Bicuspid aortic valve (BAV is the most common congenital cardiac disease and is a foremost risk factor for aortopathies. Despite the genetic basis of BAV and of the associated aortopathies, BAV-related alterations in aortic fluid-dynamics, and particularly in wall shear stresses (WSSs, likely play a role in the progression of aortopathy, and may contribute to its pathogenesis. To test whether WSS may trigger aortopathy, in this study we used 4D Flow sequences of phase-contrast cardiac magnetic resonance imaging (CMR to quantitatively compare the in vivo fluid dynamics in the thoracic aorta of two groups of subjects: (i five prospectively enrolled young patients with normo-functional BAV and with no aortic dilation and (ii ten age-matched healthy volunteers. Through the semi-automated processing of 4D Flow data, the aortic bulk flow at peak systole was quantified, and WSSs acting on the endothelium of the ascending aorta were characterized throughout the systolic phase in terms of magnitude and time-dependency through a method recently developed by our group. Variables computed for each BAV patient were compared vs. the corresponding distribution of values obtained for healthy controls. In BAV patients, ascending aorta diameter was measured on cine-CMR images at baseline and at 3-year follow-up. As compared to controls, normo-functional BAV patients were characterized by minor bulk flow disturbances at peak systole. However, they were characterized by evident alterations of WSS distribution and peak values in the ascending aorta. In particular, in four BAV patients, who were characterized by right-left leaflet fusion, WSS peak values exceeded by 27–46% the 90th percentile of the distribution obtained for healthy volunteers. Only in the BAV patient with right-non-coronary leaflet fusion the same threshold was exceeded by 132%. Also, evident alterations in the time-dependency of WSS magnitude and direction were observed. Despite, these fluid
Four hundred and two R&D personnel were surveyed through questionnaires to study the relationship between mental toughness, stress appraisal (including experience of stress and stress control), and innovation performance. The findings reveal a significant negative correlation between mental toughness and stress experience and a significant positive correlation between mental toughness and both stress control and innovation performance. Furthermore, although the experience of stress was negati...
Forche, A; Abbey, D; Pisithkul, T; Weinzierl, M A; Ringstrom, T; Bruck, D; Petersen, K; Berman, J
Genetic diversity is often generated during adaptation to stress, and in eukaryotes some of this diversity is thought to arise via recombination and reassortment of alleles during meiosis. Candida albicans, the most prevalent pathogen of humans, has no known meiotic cycle, and yet it is a heterozygous diploid that undergoes mitotic recombination during somatic growth. It has been shown that clinical isolates as well as strains passaged once through a mammalian host undergo increased levels of recombination. Here, we tested the hypothesis that stress conditions increase rates of mitotic recombination in C. albicans, which is measured as loss of heterozygosity (LOH) at specific loci. We show that LOH rates are elevated during in vitro exposure to oxidative stress, heat stress, and antifungal drugs. In addition, an increase in stress severity correlated well with increased LOH rates. LOH events can arise through local recombination, through homozygosis of longer tracts of chromosome arms, or by whole-chromosome homozygosis. Chromosome arm homozygosis was most prevalent in cultures grown under conventional lab conditions. Importantly, exposure to different stress conditions affected the levels of different types of LOH events, with oxidative stress causing increased recombination, while fluconazole and high temperature caused increases in events involving whole chromosomes. Thus, C. albicans generates increased amounts and different types of genetic diversity in response to a range of stress conditions, a process that we term "stress-induced LOH" that arises either by elevating rates of recombination and/or by increasing rates of chromosome missegregation. Stress-induced mutagenesis fuels the evolution of bacterial pathogens and is mainly driven by genetic changes via mitotic recombination. Little is known about this process in other organisms. Candida albicans, an opportunistic fungal pathogen, causes infections that require adaptation to different host environmental
This experiment examined the relationship between prenatal stress and subsequent calf temperament through weaning. The prenatal stressor utilized was repeated transportation of pregnant Brahman cows for 2 hours at 60, 80, 100, 120, and 140 days of gestation. Prenatally stressed calves (n = 41) were ...
Houtepen, Lotte C.; Vinkers, Christiaan H.; Carrillo-Roa, Tania; Hiemstra, Marieke; Van Lier, Pol A.; Meeus, Wim; Branje, Susan J. T.; Heim, Christine M.; Nemeroff, Charles B.; Mill, Jonathan; Schalkwyk, Leonard C.; Creyghton, Menno P.; Kahn, René S.; Joëls, Marian; Binder, Elisabeth B.; Boks, Marco P
DNA methylation likely plays a role in the regulation of human stress reactivity. Here we show that in a genome-wide analysis of blood DNA methylation in 85 healthy individuals, a locus in the Kit ligand gene (KITLG; cg27512205) showed the strongest association with cortisol stress reactivity (P=5.8
Cacciaglia, Raffaele; Nees, Frauke; Grimm, Oliver; Ridder, Stephanie; Pohlack, Sebastian T; Diener, Slawomira J; Liebscher, Claudia; Flor, Herta
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. Copyright © 2016 Elsevier Ltd. All rights reserved.
Bershad, Anya K; Miller, Melissa A; de Wit, Harriet
±3,4-Methylenedioxymethamphetamine (MDMA, "ecstasy") is a stimulant-psychedelic drug with unique social effects. It may dampen reactivity to negative social stimuli such as social threat and rejection. Perhaps because of these effects, MDMA has shown promise as a treatment for post-traumatic stress disorder (PTSD). However, the effect of single doses of MDMA on responses to an acute psychosocial stressor has not been tested. In this study, we sought to test the effects of MDMA on responses to stress in healthy adults using a public speaking task. We hypothesized that the drug would reduce responses to the stressful task. Volunteers (N = 39) were randomly assigned to receive placebo (N = 13), 0.5 mg/kg MDMA (N = 13), or 1.0 mg/kg MDMA (N = 13) during a stress and a no-stress session. Dependent measures included subjective reports of drug effects and emotional responses to the task, as well as salivary cortisol, heart rate, and blood pressure. The stress task produced its expected increase in physiological responses (cortisol, heart rate) and subjective ratings of stress in all three groups, and MDMA produced its expected subjective and physiological effects. MDMA alone increased ratings of subjective stress, heart rate, and saliva cortisol concentrations, but contrary to our hypothesis, it did not moderate responses to the Trier Social Stress Test. Despite its efficacy in PTSD and anxiety, MDMA did not reduce either the subjective or objective responses to stress in this controlled study. The conditions under which MDMA relieves responses to negative events or memories remain to be determined.
Creswell, J David; Pacilio, Laura E; Lindsay, Emily K; Brown, Kirk Warren
To test whether a brief mindfulness meditation training intervention buffers self-reported psychological and neuroendocrine responses to the Trier Social Stress Test (TSST) in young adult volunteers. A second objective evaluates whether pre-existing levels of dispositional mindfulness moderate the effects of brief mindfulness meditation training on stress reactivity. Sixty-six (N=66) participants were randomly assigned to either a brief 3-day (25-min per day) mindfulness meditation training or an analytic cognitive training control program. All participants completed a standardized laboratory social-evaluative stress challenge task (the TSST) following the third mindfulness meditation or cognitive training session. Measures of psychological (stress perceptions) and biological (salivary cortisol, blood pressure) stress reactivity were collected during the social evaluative stress-challenge session. Brief mindfulness meditation training reduced self-reported psychological stress reactivity but increased salivary cortisol reactivity to the TSST, relative to the cognitive training comparison program. Participants who were low in pre-existing levels of dispositional mindfulness and then received mindfulness meditation training had the greatest cortisol reactivity to the TSST. No significant main or interactive effects were observed for systolic or diastolic blood pressure reactivity to the TSST. The present study provides an initial indication that brief mindfulness meditation training buffers self-reported psychological stress reactivity, but also increases cortisol reactivity to social evaluative stress. This pattern may indicate that initially brief mindfulness meditation training fosters greater active coping efforts, resulting in reduced psychological stress appraisals and greater cortisol reactivity during social evaluative stressors. Copyright © 2014 Elsevier Ltd. All rights reserved.
Williams, John M.; And Others
Assessed the impact of stress management training as part of an academic skills training program upon students' (N=22) self-reported symptoms of stress and academic performance. Results indicated that success-stress management treatment was more effective in reducing stress and increasing academic performance than success treatment alone. (LLL)
Cox, Pete J; Kirk, Tom; Ashmore, Tom; Willerton, Kristof; Evans, Rhys; Smith, Alan; Murray, Andrew J; Stubbs, Brianna; West, James; McLure, Stewart W; King, M Todd; Dodd, Michael S; Holloway, Cameron; Neubauer, Stefan; Drawer, Scott; Veech, Richard L; Griffin, Julian L; Clarke, Kieran
Ketosis, the metabolic response to energy crisis, is a mechanism to sustain life by altering oxidative fuel selection. Often overlooked for its metabolic potential, ketosis is poorly understood outside of starvation or diabetic crisis. Thus, we studied the biochemical advantages of ketosis in humans using a ketone ester-based form of nutrition without the unwanted milieu of endogenous ketone body production by caloric or carbohydrate restriction. In five separate studies of 39 high-performance athletes, we show how this unique metabolic state improves physical endurance by altering fuel competition for oxidative respiration. Ketosis decreased muscle glycolysis and plasma lactate concentrations, while providing an alternative substrate for oxidative phosphorylation. Ketosis increased intramuscular triacylglycerol oxidation during exercise, even in the presence of normal muscle glycogen, co-ingested carbohydrate and elevated insulin. These findings may hold clues to greater human potential and a better understanding of fuel metabolism in health and disease. Copyright © 2016 Elsevier Inc. All rights reserved.
Tsai, Ming-Ling; Horng, Chi-Ting; Liu, Chun-Cheng; Shieh, Pochuen; Hung, Chun-Ling; Lu, Da-Wen; Chiang, Shang-Yi; Wu, Yi-Cheng; Chiou, Wen-Yaw
To evaluate visual function after emergent acceleration stress. Sixteen subjects were enrolled in this study. Human ejection seat trainer was used to induce six times gravitational force in the head-to-toe (z-axis) direction (+6 Gz). Visual performance was evaluated using the visual chart and contrast sensitivity (CS) at indicated times. Ocular reactions were assessed with biomicroscopy and topographic mapping. Temporary visual acuity reduction (0.02 ± 0.05 vs. 0.18 ± 0.08 logMAR visual acuity [VA]; P gravitational stress (5.42 ± 0.54 mm, P acceleration force induces significant ocular responses and visual fluctuation. Prolonged ACD deepening (>15 minutes) and PD (>30 minutes) were noted, but cornea and refraction remain stable. CS at all spatial frequencies revealed remarkable reduction immediately after ejection, and recovered to baseline levels within 30 minutes only at high spatial frequency. Neuroretinal function may involve visual fluctuation after acceleration stress, because visual fluctuation corresponds with the characters of neuroretinal function. However, further studies are necessary.
Wibowo, F.; Armaniar
Plants grown in saline soils will experience salinity stress. Salinity stresses, one of which causes oxidative stress, that cause an imbalance in the production ROS compounds (Reactive Oxygen Species), antioxidants and chlorophyll. Where the reaction of this compound can affect plant growth and plant production. This study aims to inform performance and action gene to soybean physiological character that potential to tolerant from salinity soil that characterized by the presence of SOD and POD antioxidant compounds and chlorophyll. This research used a destructive analysis from crossbred (AxN) and (GxN). A = Anjasmoro varieties and G = Grobogan varieties as female elders and N = Grobogan varieties as male elders (N1, N2, N3, N4, N5) that have been through the stage of saline soil selection. Research result can be concluded that GxN cross is more potential for Inheritance of the offspring. This can be seen from the observed skewness of character SOD, POD compounds, Chlorophyll a and chlorophyll b.
Langevin, Ariel M; Dunlop, Mary J
Stress tolerance studies are typically conducted in an all-or-none fashion. However, in realistic settings-such as in clinical or metabolic engineering applications-cells may encounter stresses at different rates. Therefore, how cells tolerate stress may depend on its rate of appearance. To address this, we studied how the rate of stress introduction affects bacterial stress tolerance by focusing on a key stress response mechanism. Efflux pumps, such as AcrAB-TolC of Escherichia coli , are membrane transporters well known for the ability to export a wide variety of substrates, including antibiotics, signaling molecules, and biofuels. Although efflux pumps improve stress tolerance, pump overexpression can result in a substantial fitness cost to the cells. We hypothesized that the ideal pump expression level would involve a rate-dependent trade-off between the benefit of pumps and the cost of their expression. To test this, we evaluated the benefit of the AcrAB-TolC pump under different rates of stress introduction, including a step, a fast ramp, and a gradual ramp. Using two chemically diverse stresses, the antibiotic chloramphenicol and the jet biofuel precursor pinene, we assessed the benefit provided by the pumps. A mathematical model describing these effects predicted the benefit as a function of the rate of stress introduction. Our findings demonstrate that as the rate of introduction is lowered, stress response mechanisms provide a disproportionate benefit to pump-containing strains, allowing cells to survive beyond the original inhibitory concentrations. IMPORTANCE Efflux pumps are ubiquitous in nature and provide stress tolerance in the cells of species ranging from bacteria to mammals. Understanding how pumps provide tolerance has far-reaching implications for diverse fields, from medicine to biotechnology. Here, we investigated how the rate of stressor appearance impacts tolerance. We focused on two distinct substrates of AcrAB-TolC efflux pumps, the
Said, N; Lakehayli, S; El Khachibi, M; El Ouahli, M; Nadifi, S; Hakkou, F; Tazi, A
Prenatal stress (PS) can induce several long-lasting behavioral and molecular abnormalities in rats. It can also be considered as a risk factor for many psychiatric diseases like schizophrenia, depression or PTSD and predispose to addiction. In this study, we investigated the effect of prenatal stress on the reinforcing properties of nicotine in the CPP paradigm. Then, we examined the mRNA expression of the D2 dopaminergic receptors using the quantitative real-time PCR technique in the nucleus accumbens (NAcc). We found that prenatally stressed rats exhibited a greater place preference for the nicotine-paired compartment than the control rats. Moreover, we observed an overexpression of the DRD2 gene in adult offspring stressed in utero and a downregulation in the PS NIC group (PS rats treated with nicotine) compared with their control counterparts (C NIC). These data suggest that maternal stress can permanently alter the offspring's addictive behavior and D2 receptors' expression. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.
Amir, O; Yamin, C; Sagiv, M; Eynon, N; Shnizer, S; Kagan, T; Reznick, A Z; Sagiv, M; Amir, R E
This study was designed to analyze serum oxidative stress (OS) levels in healthy young individuals performing a routine maximal aerobic exercise and to evaluate the correlation between OS levels and physiological parameters. Serum OS levels were studied by thermochemiluminescence (TCL) parameters at rest and following maximal aerobic exercise in 85 healthy young subjects. Levels were measured by a real time on line TCL assay (higher TCL-Ratio and TCL-H3 = lower OS level). Aerobic capacity had no effect on baseline OS levels. Post-exercise OS levels correlated with maximal oxygen uptake (V.O(2max)) (Pexercise OS levels for the whole study group did not vary from baseline values. However, individuals with higher fitness level (V.O(2max) >percentile 60) had significantly lower values of TCL-H3 (P=0.04) and tended to have lower TCL-Ratio, indicating they had elevated OS levels. In a multivariate analysis OS level was most affected by V.O(2) after VTH (anaerobic phase of the test) (P=0.003; adjusted odds ratio of 3.41, 95% confidence interval: 1.55-7.48). In conclusion, acute incremental exercise to maximal performance does not cause alterations in serum oxidant levels of healthy young individuals. In healthy individuals performing maximal aerobic exercise, OS levels correlate with maximal aerobic power.
de Zambotti, Massimiliano; Sugarbaker, David; Trinder, John; Colrain, Ian M; Baker, Fiona C
Hot flashes, hormones, and psychosocial factors contribute to insomnia risk in the context of the menopausal transition. Stress is a well-recognized factor implicated in the pathophysiology of insomnia; however the impact of stress on sleep and sleep-related processes in perimenopausal women remains largely unknown. We investigated the effect of an acute experimental stress (impending Trier Social Stress Task in the morning) on pre-sleep measures of cortisol and autonomic arousal in perimenopausal women with and without insomnia that developed in the context of the menopausal transition. In addition, we assessed the macro- and micro-structure of sleep and autonomic functioning during sleep. Following adaptation to the laboratory, twenty two women with (age: 50.4 ± 3.2 years) and eighteen women without (age: 48.5 ± 2.3 years) insomnia had two randomized in-lab overnight recordings: baseline and stress nights. Anticipation of the task resulted in higher pre-sleep salivary cortisol levels and perceived tension, faster heart rate and lower vagal activity, based on heart rate variability measures, in both groups of women. The effect of the stress manipulation on the autonomic nervous system extended into the first 4 h of the night in both groups. However, vagal tone recovered 4-6 h into the stress night in controls but not in the insomnia group. Sleep macrostructure was largely unaltered by the stress, apart from a delayed latency to REM sleep in both groups. Quantitative analysis of non-rapid eye movement sleep microstructure revealed greater electroencephalographic (EEG) power in the beta1 range (15-≤23 Hz), reflecting greater EEG arousal during sleep, on the stress night compared to baseline, in the insomnia group. Hot flash frequency remained similar on both nights for both groups. These results show that pre-sleep stress impacts autonomic nervous system functioning before and during sleep in perimenopausal women with and without insomnia. Findings also indicate
Gao, Shang-Feng; Lu, Yun-Rong; Shi, Li-Gen; Wu, Xue-Yan; Sun, Bo; Fu, Xin-Yan; Luo, Jian-Hong; Bao, Ai-Min
Nitric oxide (NO) and NO synthase-1 (NOS1) are involved in the stress response and in depression. We compared NOS-NO alterations in rats exposed to chronic unpredictable stress (CUS) with alterations in major depressive disorder (MDD) in humans. In the hypothalamus of male CUS rats we determined NOS activity, and in the paraventricular nucleus (PVN) we determined NOS1-immunoreactive (ir) cell densities and co-localization of NOS1 with stress-related neuropeptides corticotropin-releasing hormone (CRH), vasopressin (AVP) or oxytocin (OXT). We measured plasma NO levels and cortisol in male medicine-naïve MDD patients and plasma NO and corticosterone (CORT) in CUS rats. In the CUS rat total NOS activity in the hypothalamus (P=0.018) and NOS1-ir cell density in the PVN were both significantly decreased (P=0.018), while NOS1 staining was mainly expressed in OXT-ir neurons in this nucleus. Interestingly, plasma NO levels were significantly increased both in male CUS rats (P=0.001) and in male MDD patients (Pdepression. Copyright © 2014 Elsevier Ltd. All rights reserved.
Caitlin A Durkee
Full Text Available Many brain imaging studies have demonstrated reductions in gray and white matter volumes in alcoholism, with fewer investigators using diffusion tensor imaging (DTI to examine the integrity of white matter pathways. Among various medical conditions, alcoholism and post-traumatic stress disorder (PTSD are two comorbid diseases that have similar degenerative effects on the white matter integrity. Therefore, understanding and differentiating these effects would be very important in characterizing alcoholism and PTSD. Alcoholics are known to have neurocognitive deficits in decision-making, particularly in decisions related to emotionally-motivated behavior, while individuals with PTSD have deficits in emotional regulation and enhanced fear response. It is widely believed that these types of abnormalities in both alcoholism and PTSD are related to fronto-limbic dysfunction. In addition, previous studies have shown cortico-limbic fiber degradation through fiber tracking in alcoholism. DTI was used to measure white matter fractional anisotropy (FA, which provides information about tissue microstructure, possibly indicating white matter integrity. We quantitatively investigated the microstructure of white matter through whole brain DTI analysis in healthy volunteers (HV and alcohol dependent subjects without PTSD (ALC and with PTSD (ALC+PTSD. These data show significant differences in FA between alcoholics and non-alcoholic HVs, with no significant differences in FA between ALC and ALC+PTSD in any white matter structure. We performed a post-hoc region of interest analysis that allowed us to incorporate multiple covariates into the analysis and found similar results. HV had higher FA in several areas implicated in the reward circuit, emotion, and executive functioning, suggesting that there may be microstructural abnormalities in white matter pathways that contribute to neurocognitive and executive functioning deficits observed in alcoholics. Furthermore
Sarro, E C; Sullivan, R M; Barr, G
Anxiety-related disorders are among the most common psychiatric illnesses, thought to have both genetic and environmental causes. Early-life trauma, such as abuse from a caregiver, can be predictable or unpredictable, each resulting in increased prevalence and severity of a unique set of disorders. In this study, we examined the influence of early unpredictable trauma on both the behavioral expression of adult anxiety and gene expression within the amygdala. Neonatal rats were exposed to unpaired odor-shock conditioning for 5 days, which produces deficits in adult behavior and amygdala dysfunction. In adulthood, we used the Light/Dark box test to measure anxiety-related behaviors, measuring the latency to enter the lit area and quantified urination and defecation. The amygdala was then dissected and a microarray analysis was performed to examine changes in gene expression. Animals that had received early unpredictable trauma displayed significantly longer latencies to enter the lit area and more defecation and urination. The microarray analysis revealed over-represented genes related to learning and memory, synaptic transmission and trans-membrane transport. Gene ontology and pathway analysis identified highly represented disease states related to anxiety phenotypes, including social anxiety, obsessive-compulsive disorders, post-traumatic stress disorder and bipolar disorder. Addiction-related genes were also overrepresented in this analysis. Unpredictable shock during early development increased anxiety-like behaviors in adulthood with concomitant changes in genes related to neurotransmission, resulting in gene expression patterns similar to anxiety-related psychiatric disorders. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.
Li, Baojuan; Liu, Jian; Liu, Yang; Lu, Hong-Bing; Yin, Hong
The majority of studies on posttraumatic stress disorder (PTSD) so far have focused on delineating patterns of activations during cognitive processes. Recently, more and more researches have started to investigate functional connectivity in PTSD subjects using BOLD-fMRI. Functional connectivity analysis has been demonstrated as a powerful approach to identify biomarkers of different brain diseases. This study aimed to detect resting-state functional connectivity abnormities in patients with PTSD using arterial spin labeling (ASL) fMRI. As a completely non-invasive technique, ASL allows quantitative estimates of cerebral blood flow (CBF). Compared with BOLD-fMRI, ASL fMRI has many advantages, including less low-frequency signal drifts, superior functional localization, etc. In the current study, ASL images were collected from 10 survivors in mining disaster with recent onset PTSD and 10 survivors without PTSD. Decreased regional CBF in the right middle temporal gyrus, lingual gyrus, and postcentral gyrus was detected in the PTSD patients. Seed-based resting-state functional connectivity analysis was performed using an area in the right middle temporal gyrus as region of interest. Compared with the non-PTSD group, the PTSD subjects demonstrated increased functional connectivity between the right middle temporal gyrus and the right superior temporal gyrus, the left middle temporal gyrus. Meanwhile, decreased functional connectivity between the right middle temporal gyrus and the right postcentral gyrus, the right superior parietal lobule was also found in the PTSD patients. This is the first study which investigated resting-state functional connectivity in PTSD using ASL images. The results may provide new insight into the neural substrates of PTSD.
Kazi, Amajad Iqbal; Oommen, Anna
Chronic stress induces neurochemical changes that include neurotransmitter imbalance in the brain. Noise is an environmental factor inducing stress. Chronic noise stress affects monoamine neurotransmitter systems in the central nervous system. The effect on other excitatory and inhibitory neurotransmitter systems is not known. The aim was to study the role of chronic noise stress on the glutamatergic and gamma-aminobutyric acid (GABA)ergic systems of the brain. Female Wistar rats (155 ± 5 g) were unintentionally exposed to noise due to construction (75-95 db, 3-4 hours/day, 5 days a week for 7-8 weeks) in the vicinity of the animal care facility. Glutamate/GABA levels and their metabolic enzymes were evaluated in different rat brain regions (cortex, hippocampus, striatum, and cerebellum) and compared with age and gender matched nonexposed rats. Chronic noise stress decreased glutamate levels and glutaminase activity 27% and 33% in the cortex, 15% and 24% in the cerebellum. Glutamate levels increased 10% in the hippocampus, 28% in striatum and glutaminase activity 15% in striatum. Glutamine synthetase activity increased significantly in all brain regions studied, that is, cortex, hippocampus, striatum, and cerebellum (P Noise stress-increased GABA levels and glutamate alpha decarboxylase activity 20% and 45% in the cortex, 13% and 28% in the hippocampus respectively. GABA levels and glutamate alpha decarboxylase activity decreased 15% and 14%, respectively in the striatum. GABA transaminase activity was significantly reduced in the cortex (55%), hippocampus (17%), and cerebellum (33%). Chronic noise stress differentially affected glutamatergic and GABAergic neurotransmitter systems in the rat brain, which may alter glutamate and GABA neurotransmission.
Malisch, Jessica L; deWolski, Karen; Meek, Thomas H; Acosta, Wendy; Middleton, Kevin M; Crino, Ondi L; Garland, Theodore
In vertebrates, acute stressors-although short in duration-can influence physiology and behavior over a longer time course, which might have important ramifications under natural conditions. In laboratory rats, for example, acute stress has been shown to increase anxiogenic behaviors for days after a stressor. In this study, we quantified voluntary wheel-running behavior for 22 h following a restraint stress and glucocorticoid levels 24 h postrestraint. We utilized mice from four replicate lines that have been selectively bred for high voluntary wheel-running activity (HR mice) for 60 generations and their nonselected control (C) lines to examine potential interactions between exercise propensity and sensitivity to stress. Following 6 d of wheel access on a 12L∶12D photo cycle (0700-1900 hours, as during the routine selective breeding protocol), 80 mice were physically restrained for 40 min, beginning at 1400 hours, while another 80 were left undisturbed. Relative to unrestrained mice, wheel running increased for both HR and C mice during the first hour postrestraint (P Wheel running was also examined at four distinct phases of the photoperiod. Running in the period of 1600-1840 hours was unaffected by restraint stress and did not differ statistically between HR and C mice. During the period of peak wheel running (1920-0140 hours), restrained mice tended to run fewer revolutions (-11%; two-tailed P = 0.0733), while HR mice ran 473% more than C (P = 0.0008), with no restraint × line type interaction. Wheel running declined for all mice in the latter part of the scotophase (0140-0600 hours), restraint had no statistical effect on wheel running, but HR again ran more than C (+467%; P = 0.0122). Finally, during the start of the photophase (0720-1200 hours), restraint increased running by an average of 53% (P = 0.0443) in both line types, but HR and C mice did not differ statistically. Mice from HR lines had statistically higher plasma corticosterone concentrations
Conclusions: Restraint stress aggravated allergic airway inflammation in association with alterations in local immunity characterized by greater Th2-associated cytokine production and a reduced development of regulatory T cells, mediated by MORs.
Světlák, M.; Bob, P.; Roman, R.; Ježek, S.; Damborská, A.; Chládek, Jan; Shaw, D. J.; Kukleta, M.
Roč. 62, č. 6 (2013), s. 711-719 ISSN 0862-8408 Institutional support: RVO:68081731 Keywords : electrodermal activity * pointwise trasinformation * autonomic nervous system * asymmetry * stress Subject RIV: CE - Biochemistry Impact factor: 1.487, year: 2013
Pavlović, I.; Pěnčík, Aleš; Novák, Ondřej; Vujčić, V.; Radić Brkanac, S.; Lepeduš, H.; Strnad, Miroslav; Salopek-Sondi, B.
Roč. 125, APR (2018), s. 74-84 ISSN 0981-9428 R&D Projects: GA MŠk(CZ) LO1204; GA ČR(CZ) GA17-06613S Institutional support: RVO:61389030 Keywords : Auxin metabolism * Brassica rapa ssp. pekinensis * Growth inhibition * Principal component analysis * Reactive oxygen species * Short-term salinity stress * Stress hormones Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Plant sciences, botany Impact factor: 2.724, year: 2016
Mankgopo Magdeline Kgatle
Full Text Available Approximately 20% of human cancers is attributable to DNA oncogenic viruses such as human papillomavirus (HPV, hepatitis B virus (HBV, and Epstein-Barr virus (EBV. Unrepaired DNA damage is the most common and overlapping feature of these DNA oncogenic viruses and a source of genomic instability and tumour development. Sustained DNA damage results from unceasing production of reactive oxygen species and activation of inflammasome cascades that trigger genomic changes and increased propensity of epigenetic alterations. Accumulation of epigenetic alterations may interfere with genome-wide cellular signalling machineries and promote malignant transformation leading to cancer development. Untangling and understanding the underlying mechanisms that promote these detrimental effects remain the major objectives for ongoing research and hope for effective virus-induced cancer therapy. Here, we review current literature with an emphasis on how DNA damage influences HPV, HVB, and EBV replication and epigenetic alterations that are associated with carcinogenesis.
Full Text Available Chronic stress enhances risk for psychiatric disorders, and in animal models is known to evoke depression-like behavior accompanied by perturbed neurohormonal, metabolic, neuroarchitectural and transcriptional changes. Serotonergic neurotransmission, including serotonin2A (5-HT2A receptors, have been implicated in mediating specific aspects of stress-induced responses. Here we investigated the influence of chronic unpredictable stress (CUS on depression-like behavior, serum metabolic measures, and gene expression in stress-associated neurocircuitry of the prefrontal cortex (PFC and hippocampus in 5-HT2A receptor knockout (5-HT2Aâ/â and wild-type mice of both sexes. While 5-HT2Aâ/â male and female mice exhibited a baseline reduced anxiety-like state, this did not alter the onset or severity of behavioral despair during and at the cessation of CUS, indicating that these mice can develop stress-evoked depressive behavior. Analysis of metabolic parameters in serum revealed a CUS-evoked dyslipidemia, which was abrogated in 5-HT2Aâ/â female mice with a hyperlipidemic baseline phenotype. 5-HT2Aâ/â male mice in contrast did not exhibit such a baseline shift in their serum lipid profile. Specific stress-responsive genes (Crh, Crhr1, Nr3c1, and Nr3c2, trophic factors (Bdnf, Igf1 and immediate early genes (IEGs (Arc, Fos, Fosb, Egr1-4 in the PFC and hippocampus were altered in 5-HT2Aâ/â mice both under baseline and CUS conditions. Our results support a role for the 5-HT2A receptor in specific metabolic and transcriptional, but not behavioral, consequences of CUS, and highlight that the contribution of the 5-HT2A receptor to stress-evoked changes is sexually dimorphic. Keywords: 5-HT2Aâ/â mice, Prefrontal cortex, Hippocampus, Gene expression, Sexual dimorphism, Despair
George, Iniga S; Pascovici, Dana; Mirzaei, Mehdi; Haynes, Paul A
Grapes (Vitis vinifera) are a valuable fruit crop and wine production is a major industry. Global warming and expanded range of cultivation will expose grapes to more temperature stresses in future. Our study investigated protein level responses to abiotic stresses, with particular reference to proteomic changes induced by the impact of four different temperature stress regimes, including both hot and cold temperatures, on cultured grape cells. Cabernet Sauvignon cell suspension cultures grown at 26°C were subjected to 14 h of exposure to 34 and 42°C for heat stress, and 18 and 10°C for cold stress. Cells from the five temperatures were harvested in biological triplicates and label-free quantitative shotgun proteomic analysis was performed. A total of 2042 non-redundant proteins were identified from the five temperature points. Fifty-five proteins were only detected in extreme heat stress conditions (42°C) and 53 proteins were only detected at extreme cold stress conditions (10°C). Gene Ontology (GO) annotations of differentially expressed proteins provided insights into the metabolic pathways that are involved in temperature stress in grape cells. Sugar metabolism displayed switching between alternative and classical pathways during temperature stresses. Additionally, nine proteins involved in the phenylpropanoid pathway were greatly increased in abundance at extreme cold stress, and were thus found to be cold-responsive proteins. All MS data have been deposited in the ProteomeXchange with identifier PXD000977 (http://proteomecentral.proteomexchange.org/dataset/PXD000977). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Lester, Barry M.; LaGasse, Linda L.; Shankaran, Seetha; Bada, Henrietta S.; Bauer, Charles R.; Lin, Richard; Das, Abhik; Higgins, Rosemary
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
Leimu, Roosa; Kloss, Lena; Fischer, Markus
Pathogenesis-related proteins, chitinases (CHT) and β-1,3-glucanases (GLU), are stress proteins up-regulated as response to extrinsic environmental stress in plants. It is unknown whether these PR proteins are also influenced by inbreeding, which has been suggested to constitute intrinsic genetic stress, and which is also known to affect the ability of plants to cope with environmental stress. We investigated activities of CHT and GLU in response to inbreeding in plants from 13 Ragged Robin (Lychnis flos-cuculi) populations. We also studied whether activities of these enzymes were associated with levels of herbivore damage and pathogen infection in the populations from which the plants originated. We found an increase in pathogenesis-related protein activity in inbred plants from five out of the 13 investigated populations, which suggests that these proteins may play a role in how plants respond to intrinsic genetic stress brought about by inbreeding in some populations depending on the allele frequencies of loci affecting the expression of CHT and the past levels of inbreeding. More importantly, we found that CHT activities were higher in plants from populations with higher levels of herbivore or pathogen damage, but inbreeding reduced CHT activity in these populations disrupting the increased activities of this resistance-related enzyme in populations where high resistance is beneficial. These results provide novel information on the effects of plant inbreeding on plant-enemy interactions on a biochemical level.
Full Text Available Pathogenesis-related proteins, chitinases (CHT and β-1,3-glucanases (GLU, are stress proteins up-regulated as response to extrinsic environmental stress in plants. It is unknown whether these PR proteins are also influenced by inbreeding, which has been suggested to constitute intrinsic genetic stress, and which is also known to affect the ability of plants to cope with environmental stress. We investigated activities of CHT and GLU in response to inbreeding in plants from 13 Ragged Robin (Lychnis flos-cuculi populations. We also studied whether activities of these enzymes were associated with levels of herbivore damage and pathogen infection in the populations from which the plants originated. We found an increase in pathogenesis-related protein activity in inbred plants from five out of the 13 investigated populations, which suggests that these proteins may play a role in how plants respond to intrinsic genetic stress brought about by inbreeding in some populations depending on the allele frequencies of loci affecting the expression of CHT and the past levels of inbreeding. More importantly, we found that CHT activities were higher in plants from populations with higher levels of herbivore or pathogen damage, but inbreeding reduced CHT activity in these populations disrupting the increased activities of this resistance-related enzyme in populations where high resistance is beneficial. These results provide novel information on the effects of plant inbreeding on plant-enemy interactions on a biochemical level.
Boeck, Christina; Koenig, Alexandra Maria; Schury, Katharina; Geiger, Martha Leonie; Karabatsiakis, Alexander; Wilker, Sarah; Waller, Christiane; Gündel, Harald; Fegert, Jörg Michael; Calzia, Enrico; Kolassa, Iris-Tatjana
The experience of maltreatment during childhood is associated with chronic low-grade inflammation in adulthood. However, the molecular mechanisms underlying this pro-inflammatory phenotype remain unclear. Mitochondria were recently found to principally coordinate inflammatory processes via both inflammasome activation and inflammasome-independent pathways. To this end, we hypothesized that alterations in immune cell mitochondrial functioning and oxidative stress might be at the interface between the association of maltreatment experiences during childhood and inflammation. We analyzed pro-inflammatory biomarkers (levels of C-reactive protein, cytokine secretion by peripheral blood mononuclear cells (PBMC) in vitro, PBMC composition, lysophosphatidylcholine levels), serum oxidative stress levels (arginine:citrulline ratio, l-carnitine and acetylcarnitine levels) and mitochondrial functioning (respiratory activity and density of mitochondria in PBMC) in peripheral blood samples collected from 30 women (aged 22-44years) with varying degrees of maltreatment experiences in form of abuse and neglect during childhood. Exposure to maltreatment during childhood was associated with an increased ROS production, higher levels of oxidative stress and an increased mitochondrial activity in a dose-response relationship. Moreover, the increase in mitochondrial activity and ROS production were positively associated with the release of pro-inflammatory cytokines by PBMC. Decreased serum levels of lysophosphatidylcholines suggested higher inflammasome activation with increasing severity of child maltreatment experiences. Together these findings offer preliminary evidence for the association of alterations in immune cell mitochondrial functioning, oxidative stress and the pro-inflammatory phenotype observed in individuals with a history of maltreatment during childhood. The results emphasize that the early prevention of child abuse and neglect warrants more attention, as the
Ghosh, S; Banerjee, K K; Vaidya, V A; Kolthur-Seetharam, U
Early-life adversity is associated with an enhanced risk for adult psychopathology. Psychiatric disorders such as depression exhibit comorbidity for metabolic dysfunction, including obesity and diabetes. However, it is poorly understood whether, besides altering anxiety and depression-like behaviour, early stress also evokes dysregulation of metabolic pathways and enhances vulnerability for metabolic disorders. We used the rodent model of the early stress of maternal separation (ES) to examine the effects of early stress on serum metabolites, insulin-like growth factor (IGF)-1 signalling, and muscle mitochondrial content. Adult ES animals exhibited dyslipidaemia, decreased serum IGF1 levels, increased expression of liver IGF binding proteins, and a decline in the expression of specific metabolic genes in the liver and muscle, including Pck1, Lpl, Pdk4 and Hmox1. These changes occurred in the absence of alterations in body weight, food intake, glucose tolerance, insulin tolerance or insulin levels. ES animals also exhibited a decline in markers of muscle mitochondrial content, such as mitochondrial DNA levels and expression of TFAM (transcription factor A, mitochondrial). Furthermore, the expression of several genes involved in mitochondrial function, such as Ppargc1a, Nrf1, Tfam, Cat, Sesn3 and Ucp3, was reduced in skeletal muscle. Adult-onset chronic unpredictable stress resulted in overlapping and distinct consequences from ES, including increased circulating triglyceride levels, and a decline in the expression of specific metabolic genes in the liver and muscle, with no change in the expression of genes involved in muscle mitochondrial function. Taken together, our results indicate that a history of early adversity can evoke persistent changes in circulating IGF-1 and muscle mitochondrial function and content, which could serve to enhance predisposition for metabolic dysfunction in adulthood. © 2016 British Society for Neuroendocrinology.
Full Text Available Stress is a major risk factor in the onset of several neuropsychiatric disorders including anxiety and depression. Although several studies have shown that social isolation stress during postweaning period induces behavioral and brain molecular changes, the effects of social isolation on behavior during adulthood have been less characterized. Aim of this work was to investigate the relationship between the behavioral alterations and brain molecular changes induced by chronic social isolation stress in adult male mice. Plasma corticosterone levels and adrenal glands weight were also analyzed. Socially isolated (SI mice showed higher locomotor activity, spent less time in the open field center, and displayed higher immobility time in the tail suspension test compared to group-housed (GH mice. SI mice exhibited reduced plasma corticosterone levels and reduced difference between right and left adrenal glands. SI showed lower mRNA levels of the BDNF-7 splice variant, c-Fos, Arc, and Egr-1 in both hippocampus and prefrontal cortex compared to GH mice. Finally, SI mice exhibited selectively reduced mGluR1 and mGluR2 levels in the prefrontal cortex. Altogether, these results suggest that anxious- and depressive-like behavior induced by social isolation stress correlates with reduction of several neuroplasticity-related genes in the hippocampus and prefrontal cortex of adult male mice.
Full Text Available Salinity is one the major limiting environmental factors which has negative side effects on crop production. The purpose of this study was to investigate the differences between the gradual and sudden salt stress effects on biomass accumulation associated with whole plant development in three different tissues of two wheat species ( Triticum aestivum and Triticum durum under hydroponic conditions in the long term. Considering the effects of sudden and gradual stress for biomass accumulation, while importance of salinity x genotype interaction for fresh weights was 5%, association for salinity x tissue type was found as 1% important. Interestingly, root branching and development of lateral roots were much more negatively affected by gradual stress rather than sudden salt application. Our results demonstrated that root and leaf were both critical tissues to test the salt tolerance by physiologically but sheath tissue might be used as an alternative source of variation for solving the interactions between root and leaves in wheat.
Olesen, Mikkel V.; Wörtwein, Gitta; Pakkenberg, Bente
The neurobiological mechanisms underlying depression are not fully understood. Only a few previous studies have used validated stereological methods to test how stress and animal paradigms of depression affect adult hippocampal neurogenesis and whether antidepressant therapy can counteract possible...... changes in an animal model. Thus, in this study we applied methods that are state of the art in regard to stereological cell counting methods. Using a validated rat model of depression in combination with a clinically relevant schedule of electroconvulsive stimulation, we estimated the total number...... of newly formed neurons in the hippocampal subgranular zone. Also estimated were the total number of neurons and the volume of the granule cell layer in adult rats subjected to chronic restraint stress and electroconvulsive stimulation either alone or in combination. We found that chronic restraint stress...
Kurhe, Yeshwant; Radhakrishnan, Mahesh; Gupta, Deepali; Devadoss, Thangaraj
The inconsistent therapeutic outcome necessitates identifying novel compounds for the treatment of depression. Therefore, the present study is aimed at evaluating the antidepressant-like effects of a novel 5-HT3 receptor antagonist 3-methoxy-N-p-tolylquinoxalin-2-carboxamide (QCM-4) on chronic unpredictable mild stress (CUMS) induced behavioral and biochemical alterations in mice. Animals were subjected to different stressors for a period of 28 days. Thereafter, battery tests like locomotor score, sucrose preference test, forced swim test (FST), tail suspension test (TST), elevated plus maze (EPM) and open field test (OFT) were performed. Biochemical assays like lipid peroxidation, nitrite levels, reduced glutathione (GSH), catalase and superoxide dismutase (SOD) were assessed in brain homogenate. QCM-4 dose dependently reversed the CUMS induced behavioral and biochemical alterations by increasing the sucrose consumption, reducing the immobility time in FST and TST, increasing the percent time in open arm in EPM and increasing the ambulation along with the rearings and decreased number of fecal pellets in OFT. Further, biochemical alterations were attenuated by QCM-4 as indicated by reduced lipid peroxidation and nitrite levels and elevated antioxidant enzyme levels like GSH, catalase and SOD. QCM-4 attenuated the behavioral and biochemical derangements induced by CUMS in mice, indicating antidepressant behavior of the novel compound. © 2013 Royal Pharmaceutical Society.
.... Hardiness has also been thought to exert main effects on health and performance outcomes. In Study 1, relationships between hardiness, perceived stress, depression, and academic performance were investigated...
The chilling conditions of apple cold storage can provoke an economically significant necrotic peel disorder called superficial scald (scald) in susceptible cultivars. Disorder development can be reduced by inhibiting ethylene action or oxidative stress. We found previously that scald is preceded b...
Fich, Lars Brorson; Jönsson, Peter; Kirkegaard, Poul Henning; Wallergård, Mattias; Garde, Anne Helene; Hansen, Åse
Is has long been established, that views to natural scenes can a have a dampening effect on physiological stress responses. However, as people in Europe, Canada and North America today spent 50-85% of their time indoors, attention might also be paid to how the artificial man-made indoor environment influences these mechanisms. The question that this study attempts to start addressing is therefore whether certain design, characteristics of indoor spaces can make a difference to the physiological stress response as well. Using a virtual version of the Trier Social Stress Test, in which the space is computer generated and properties of the space therefore can be systematically varied, we measured saliva cortisol and heart rate variability in participants in a closed room versus a room with openings. As shown by a significant linear contrast interaction between groups and TSST conditions, participants in the closed room responded with more pronounced cortisol reactivity to stress induction, and continued to show higher levels throughout recovery, compared to participants in the open room. No differences were found regarding any part of the autonomic nervous system. Copyright © 2014 Elsevier Inc. All rights reserved.
Campus, P; Maiolati, M; Orsini, C; Cabib, S
Genetic and stress-related factors interact to foster mental disorders, possibly through dysfunctional learning. In a previous study we reported that a temporary experience of reduced food availability increases forced swim (FS)-induced helplessness tested 14days after a first experience in mice of the standard inbred C57BL/6(B6) strain but reduces it in mice of the genetically unrelated DBA/2J (D2) strain. Because persistence of FS-induced helplessness influences adaptive coping with stress challenge and involve learning processes the present study tested whether the behavioral effects of restricted feeding involved altered consolidation of FS-related learning. First, we demonstrated that restricted feeding does not influence behavior expressed on the first FS experience, supporting a specific effect on persistence rather then development of helplessness. Second, we found that FS-induced c-fos expression in the infralimbic cortex (IL) was selectively enhanced in food-restricted (FR) B6 mice and reduced in FR D2 mice, supporting opposite alterations of consolidation processes involving this brain area. Third, we demonstrated that immediate post-FS inactivation of IL prevents 24h retention of acquired helplessness by continuously free-fed mice of both strains, indicating the requirement of a functioning IL for consolidation of FS-related learning in either mouse strain. Finally, in line with the known role of IL in consolidation of extinction memories, we found that restricted feeding selectively facilitated 24h retention of an acquired extinction in B6 mice whereas impairing it in D2 mice. These findings support the conclusion that an experience of reduced food availability strain-specifically affects persistence of newly acquired passive coping strategies by altering consolidation of extinction-like inhibitory learning. Copyright © 2016 Elsevier B.V. All rights reserved.
Eltahawy, N A; Elsonbaty, S M; Abunour, S; Zahran, W E
Environmental and occupational exposure to aluminum along with ionizing radiation results in serious health problems. This study was planned to investigate the impact of oxidative stress provoked by exposure to ionizing radiation with aluminum administration upon cellular ultra structure and apoptotic changes in Paneth cells of rat small intestine . Animals received daily aluminum chloride by gastric gavage at a dose 0.5 mg/Kg BW for 4 weeks. Whole body gamma irradiation was applied at a dose 2 Gy/week up to 8 Gy. Ileum malondialdehyde, advanced oxidative protein products, protein carbonyl and tumor necrosis factor-alpha were assessed as biomarkers of lipid peroxidation, protein oxidation and inflammation respectively along with superoxide dismutase, catalase, and glutathione peroxidase activities as enzymatic antioxidants. Moreover, analyses of cell cycle division and apoptotic changes were evaluated by flow cytometry. Intestinal cellular ultra structure was investigated using transmission electron microscope.Oxidative and inflammatory stresses assessment in the ileum of rats revealed that aluminum and ionizing radiation exposures exhibited a significant effect upon the increase in oxidative stress biomarkers along with the inflammatory marker tumor necrosis factor-α accompanied by a significant decreases in the antioxidant enzyme activities. Flow cytometric analyses showed significant alterations in the percentage of cells during cell cycle division phases along with significant increase in apoptotic cells. Ultra structurally, intestinal cellular alterations with marked injury in Paneth cells at the sites of bacterial translocation in the crypt of lumens were recorded. The results of this study have clearly showed that aluminum and ionizing radiation exposures induced apoptosis with oxidative and inflammatory disturbance in the Paneth cells of rat intestine, which appeared to play a major role in the pathogenesis of cellular damage. Furthermore, the
Full Text Available Exposure to early life stress may profoundly influence the developing brain in lasting ways. Neuropsychiatric disorders associated with early life adversity may involve neural changes reflected in EEG power as a measure of brain activity and disturbed sleep. The main aim of the present study was for the first time to characterize possible changes in adult EEG power after postnatal maternal separation in rats. Furthermore, in the same animals, we investigated how EEG power and sleep architecture were affected after exposure to a chronic mild stress protocol. During postnatal day 2-14 male rats were exposed to either long maternal separation (180 min or brief maternal separation (10 min. Long maternally separated offspring showed a sleep-wake nonspecific reduction in adult EEG power at the frontal EEG derivation compared to the brief maternally separated group. The quality of slow wave sleep differed as the long maternally separated group showed lower delta power in the frontal-frontal EEG and a slower reduction of the sleep pressure. Exposure to chronic mild stress led to a lower EEG power in both groups. Chronic exposure to mild stressors affected sleep differently in the two groups of maternal separation. Long maternally separated offspring showed more total sleep time, more episodes of rapid eye movement sleep and higher percentage of non-rapid eye movement episodes ending in rapid eye movement sleep compared to brief maternal separation. Chronic stress affected similarly other sleep parameters and flattened the sleep homeostasis curves in all offspring. The results confirm that early environmental conditions modulate the brain functioning in a long-lasting way.
Stricker, Nikki H; Keller, Jenna E; Castillo, Diane T; Haaland, Kathleen Y
Neurocognitive problems are common with posttraumatic stress disorder (PTSD) and are important to understand because of their association with the success of PTSD treatment and its potential neural correlates. To our knowledge, this is the first neurocognitive study in an all-female U.S. veteran sample, some of whom had PTSD. We examined neurocognitive performance and assessed whether learning deficits, common in PTSD, were associated with executive functioning. Veterans with PTSD (n = 56) and without (n = 53) were evaluated for psychiatric and neurocognitive status. The PTSD group had a lower estimated IQ (d = 0.53) and performed more poorly on all neurocognitive domains (d range = 0.57-0.88), except verbal retention (d = 0.04). A subset of the 2 groups that were matched on IQ and demographics similarly demonstrated poorer performance for the PTSD group on all neurocognitive domains (d range = 0.52-0.79), except verbal retention (d = 0.15). Within the PTSD group, executive functioning accounted for significant variance in verbal learning over and above IQ and processing speed (ΔR(2) = .06), as well as depression (ΔR(2) = .07) and PTSD severity (ΔR(2) = .06). This study demonstrated that female veterans with PTSD performed more poorly than females without PTSD on several neurocognitive domains, including verbal learning, processing speed, and executive functioning. Replication of these results using a control group of veterans with more similar trauma exposure, history of mild traumatic brain injury, and psychiatric comorbidities would solidify these findings. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.
Myburgh, Kathryn H
Supplement use among athletes is widespread, including non-traditional and biological compounds. Despite increasing research, a comprehensive and critical review on polyphenol supplementation and exercise is still lacking. This review is relevant for researchers directly involved in the topic, as well as those with a broad interest in athletic performance enhancement and sports nutrition. The purpose of this review is to present background information on groups of polyphenols and their derivatives because their differing chemical structures influence mechanisms of action; to discuss the potential of plant, fruit and vegetable-based biological supplements, high in polyphenol content, to affect exercise performance and biomarkers of oxidative stress and exercise-induced muscle damage; and to critically discuss the exercise studies and biomarkers used. Subjects in the studies reviewed were either sedentary, healthy individuals, or active, recreationally trained or well-trained athletes. Polyphenol supplementation in exercise studies included mainly extracts (multicomponent or purified), juices, infusions or an increased intake of polyphenol-rich foods. This review includes details of supplement doses and exercise test protocols. Many studies considered only the performance or one or two selected biomarkers of antioxidant capacity instead of a comprehensive choice of biomarkers to assess damage to lipids or proteins. Evidence is insufficient to make recommendations for or against the use of polyphenol supplementation (neither specific polyphenols nor specific doses) for either recreational, competitive or elite athletes. Polyphenols have multiple biological effects, and future exercise studies must be designed appropriately and specifically to determine physiological interactions between exercise and the selected supplement, rather than considering performance alone.
Murray, Kevin O.; Paris, Hunter L.; Fly, Alyce D.; Chapman, Robert F.; Mickleborough, Timothy D.
Rinsing the mouth with a carbohydrate solution has been shown to improve exercise performance in a manner similar to carbohydrate ingestion. However, the underlying mechanisms behind these ergogenic benefits remain unclear. This study evaluated whether rinsing the mouth with a carbohydrate solution alters plasma insulin and glucose concentration during the initial stages of a 40 km cycling time-trial. Eight trained, competitive cyclists [age (mean ± SEM) = 24 ± 2 y; V̇O2max = 64.5 ± 2.2 ml·kg-1·min-1] completed three simulated 40 km time-trials comprised of a familiarization trial, a carbohydrate condition (CHO) and a placebo mouth rinse condition (PLA). In the two mouth rinse conditions, rinsing was administered prior to onset of exercise and every 5 km throughout exercise. Plasma insulin was collected at 5 km intervals throughout the first 25 km, and glucose samples were collected at 5 km intervals throughout the exercise bout. No change in plasma insulin was detected between conditions (p = 0.638, ES stable throughout exercise. Time to complete the 40 km time-trial was significantly faster for CHO (67.1 ± 1.1 min) compared to PLA [67.9 ± 1.0 min; (P = 0.028, ES 0.27)]. Performance time was faster by an average of 1.1% (95% confidence interval range 0.2-2.0%) in the CHO condition. Exercise intensity (% V̇O2max) throughout the trial was similar between conditions (p = 0.846). Respiratory exchange ratio was not significantly different between conditions (0.88 ± 0.01 for PLA, and 0.91 ± 0.01 for GLC; p = 0.081). Performance gains elicited by a carbohydrate mouth rinse occurred independently of changes in plasma insulin concentration. Key points Carbohydrate mouth rinsing has been shown to improve endurance performance for exercise lasting approximately 1 h in duration. The mechanisms responsible for performance gains are yet to be fully understood. Although 40 km cycling time-trial performance improved when rinsing the mouth with a carbohydrate solution
Seher, M.; Shabbir, G.; Rasheed, A.
This study was conducted to evaluate divergent wheat germplasm for their performance under drought and control conditions. The germplasm consists of wheat land races of Pakistan, advanced D-genome synthetic derivatives and high yielding varieties of Pakistan. This wide array of germplasm was selected to identify sources, which can be opted later by the wheat breeders while breeding for drought tolerance. The evaluation parameters involved some important physiochemical testing and morphological characteristics in the field under drought and control conditions. Based on these parameters, 13 wheat genotypes were selected on the basis of their best performance regarding morphological and physiological parameters. These genotypes exhibited higher yield under drought stress conditions and increased percentage of proline, sugar, SOD and protein content under laboratory conditions as compared to the susceptible genotypes. Correlation studies revealed that grains per spike (GPS) and thousand grain weight (TGW) had direct relationship with spike length (SL), proline and sugar content under both control and drought conditions. Thus, these parameters can be used as selection criteria for the identification of tolerant genotypes. (author)
Pleizier, Naomi; Wilson, Alexander D M; Shultz, Aaron D; Cooke, Steven J
Although consistent individual-level differences in behaviour are widespread and potentially important in evolutionary and ecological processes, relatively few studies focus on the physiological mechanisms that might underlie and regulate these individual-level differences in wild populations. We conducted experiments to determine whether checkered pufferfish (Sphoeroides testudineus), which were collected from a dynamic (in terms of depth and water temperature) tidal mangrove creek environment in The Bahamas, have consistent individual-level differences in locomotor activity and the response to a simulated predator threat, as well as swimming performance and puffing in response to stressors. The relationships between personality and performance traits were evaluated to determine whether they represented stress-coping styles or syndromes. Subsequently, a displacement study was conducted to determine how personality and performance in the laboratory compared to movements in the field. In addition, we tested whether a physiological dose of the stress hormone cortisol would alter individual consistency in behavioural and performance traits. We found that pufferfish exhibited consistent individual differences in personality traits over time (e.g., activity and the duration of a response to a threat) and that performance was consistent between the lab and the natural enclosure. Locomotor activity and the duration of startled behaviour were not associated with swimming and puffing performance. Locomotor activity, puffing performance, and swimming performance were not related to whether fish returned to the tidal creek of capture after displacement. Similarly, a cortisol treatment did not modify behaviour or performance in the laboratory. The results reveal that consistent individual-level differences in behaviour and performance were present in a population from a fluctuating and physiologically challenging environment but that such traits are not necessarily correlated
Rosa, Elena; Saastamoinen, Marjo
Organisms with complex life-cycles acquire essential nutrients as juveniles, and hence even a short-term food stress during development can impose serious fitness costs apparent in adults. We used the Glanville fritillary butterfly to investigate the effects of larval food stress on adult performance under semi-natural conditions in a population enclosure. We were specifically interested in whether the negative effects observed were due to body mass reduction only or whether additional effects unrelated to pupal mass were evident. The two sexes responded differently to the larval food stress. In females, larval food stress reduced pupal mass and reproductive performance. The reduced reproductive performance was partially mediated by pupal mass reduction. Food stressed females also had reduced within-patch mobility, and this effect was not dependent on pupal mass. Conversely, food stress had no effect on male pupal mass, suggesting a full compensation via prolonged development time. Nonetheless, food stressed males were less likely to sire any eggs, potentially due to changes in their territorial behavior, as indicated by food stress also increasing male within-patch mobility (i.e., patrolling behavior). When males did sire eggs, the offspring number and viability were unaffected by male food stress treatment. Viability was in general higher for offspring sired by lighter males. Our study highlights how compensatory mechanisms after larval food stress can act in a sex-specific manner and that the alteration in body mass is only partially responsible for the reduced adult performance observed.
Morales, Anderson Pontes; Sampaio-Jorge, Felipe; da Cruz Rangel, Luiz Felipe; de Souza Menezes, Jackson; Leite, Tiago Costa; Ribeiro, Beatriz Gonçalves
The aim of this study was to evaluate the curves of cardiorespiratory variables during cardiopulmonary exercise testing (CPET) in soccer players who had acute alterations in the glomerular filtration rate (GFR) after performing the pre-season training protocol. Sixteen male professional soccer players (25 ± 3 years; 179 ± 2 cm; and 77 ± 6 kg) were evaluated for oxygen uptake (VO 2 ), heart rate (HR) and pulse relative oxygen (relative O 2 Pulse) curves with intervals corresponding to 10% of the total duration of CPET. Athletes were grouped according to the GFR and classified as decreased GFR (dGFR; n = 8) and normal GFR (nGFR; n = 8). Athletes from the dGFR group exhibited lower VO 2 values (p values (p values (p < 0.05) when 70% (dGFR 25.6 ± 8.4 vs. nGFR 27.9 ± 9.7 ml·beat -1 ·kg -1 ), 80% (dGFR 26.6 ± 8.8 vs. nGFR 29.1 ± 10.0 ml·beat -1 ·kg -1 ), 90% (dGFR 27.1 ± 9.0 vs. nGFR 30.8 ± 10.6 ml·beat -1 ·kg -1 ) and 100% (dGFR 28 ± 9.2 vs. nGFR 31.8 ± 10.9 ml·beat -1 ·kg -1 ) of the test was complete. A correlation was found (r = -0.66, R 2 = 0.44, p = 0.00) between lower VO 2 peak and elevated levels of urinary protein excretion. In conclusion, soccer players with reduced kidney function after performing the pre-season training protocol also presented alterations in cardiopulmonary variables. We suggest that monitoring of renal function may be used to identify less conditioned soccer players.
Full Text Available Abstract Background Erythropoietin (EPO is known to improve exercise performance by increasing oxygen blood transport and thus inducing a higher maximum oxygen uptake (VO2max. Furthermore, treatment with (or overexpression of EPO induces protective effects in several tissues, including the myocardium. However, it is not known whether EPO exerts this protective effect when present at physiological levels. Given that EPO receptors have been identified in skeletal muscle, we hypothesized that EPO may have a direct, protective effect on this tissue. Thus, the objectives of the present study were to confirm a decrease in exercise performance and highlight muscle transcriptome alterations in a murine EPO functional knock-out model (the EPO-d mouse. Methods We determined VO2max peak velocity and critical speed in exhaustive runs in 17 mice (9 EPO-d animals and 8 inbred controls, using treadmill enclosed in a metabolic chamber. Mice were sacrificed 24h after a last exhaustive treadmill exercise at critical speed. The tibialis anterior and soleus muscles were removed and total RNA was extracted for microarray gene expression analysis. Results The EPO-d mice’s hematocrit was about 50% lower than that of controls (p 1.4 and 115 were strongly down-regulated (normalized ratio Conclusions Our results showed that the lack of functional EPO induced a decrease in the aerobic exercise capacity. This decrease was correlated with the hematocrit and reflecting poor oxygen supply to the muscles. The observed alterations in the muscle transcriptome suggest that physiological concentrations of EPO exert both direct and indirect muscle-protecting effects during exercise. However, the signaling pathway involved in these protective effects remains to be described in detail.
Canto Maya, Christian M.
In oil and gas production, internal corrosion of pipelines causes the highest incidence of recurring failures. Ensuring the integrity of ageing pipeline infrastructure is an increasingly important requirement. One of the most widely applied methods to reduce internal corrosion rates is the continuous injection of chemicals in very small quantities, called corrosion inhibitors. These chemical substances form thin films at the pipeline internal surface that reduce the magnitude of the cathodic and/or anodic reactions. However, the efficacy of such corrosion inhibitor films can be reduced by different factors such as multiphase flow, due to enhanced shear stress and mass transfer effects, loss of inhibitor due to adsorption on other interfaces such as solid particles, bubbles and droplets entrained by the bulk phase, and due to chemical interaction with other incompatible substances present in the stream. The first part of the present project investigated the electrochemical behavior of two organic corrosion inhibitors (a TOFA/DETA imidazolinium, and an alkylbenzyl dimethyl ammonium chloride), with and without an inorganic salt (sodium thiosulfate), and the resulting enhancement. The second part of the work explored the performance of corrosion inhibitor under multiphase (gas/liquid, solid/liquid) flow. The effect of gas/liquid multiphase flow was investigated using small and large scale apparatus. The small scale tests were conducted using a glass cell and a submersed jet impingement attachment with three different hydrodynamic patterns (water jet, CO 2 bubbles impact, and water vapor cavitation). The large scale experiments were conducted applying different flow loops (hilly terrain and standing slug systems). Measurements of weight loss, linear polarization resistance (LPR), and adsorption mass (using an electrochemical quartz crystal microbalance, EQCM) were used to quantify the effect of wall shear stress on the performance and integrity of corrosion inhibitor
Victoria, Nicole C; Karom, Mary C; Eichenbaum, Hila; Murphy, Anne Z
Less than 60% of infants undergoing invasive procedures in the neonatal intensive care unit receive analgesic therapy. These infants show long-term decreases in pain sensitivity and cortisol reactivity. In rats, we have previously shown that inflammatory pain experienced on the day of birth significantly decreases adult somatosensory thresholds and responses to anxiety- and stress-provoking stimuli. These long-term changes in pain and stress responsiveness are accompanied by two-fold increases in central met-enkephalin and β-endorphin expression. However, the time course over which these changes in central opioid peptide expression occur, relative to the time of injury, are not known. The present studies were conducted to determine whether the observed changes in adult opioid peptide expression were present within the first postnatal week following injury. The impact of neonatal inflammation on plasma corticosterone, a marker for stress reactivity, was also determined. Brain, spinal cord, and trunk blood were harvested at 24 h, 48 h, and 7 d following intraplantar administration of the inflammatory agent carrageenan on the day of birth. Radioimmunoassay was used to determine plasma corticosterone and met-enkephalin and β-endorphin levels within the forebrain, cortex, midbrain, and spinal cord. Within 24 h of injury, met-enkephalin levels were significantly increased in the midbrain, but decreased in the spinal cord and cortex; forebrain β-endorphin levels were significantly increased as a result of early life pain. Corticosterone levels were also significantly increased. At 7 d post-injury, opioid peptides remained elevated relative to controls, suggesting a time point by which injury-induced changes become programmed and permanent. Copyright © 2013 Wiley Periodicals, Inc.
Model, Camila S; Gomes, Lara M; Scaini, Giselli; Ferreira, Gabriela K; Gonçalves, Cinara L; Rezin, Gislaine T; Steckert, Amanda V; Valvassori, Samira S; Varela, Roger B; Quevedo, João; Streck, Emilio L
Studies have consistently reported the participation of oxidative stress in bipolar disorder (BD). Evidences indicate that omega-3 (ω3) fatty acids play several important roles in brain development and functioning. Moreover, preclinical and clinical evidence suggests roles for ω3 fatty acids in BD. Considering these evidences, the present study aimed to investigate the effects of ω3 fatty acids on locomotor behavior and oxidative stress parameters (TBARS and protein carbonyl content) in brain of rats subjected to an animal model of mania induced by fenproporex. The fenproporex treatment increased locomotor behavior in saline-treated rats under reversion and prevention model, and ω3 fatty acids prevented fenproporex-related hyperactivity. Moreover, fenproporex increased protein carbonyls in the prefrontal cortex and cerebral cortex, and the administration of ω3 fatty acids reversed this effect. Lipid peroxidation products also are increased in prefrontal cortex, striatum, hippocampus and cerebral after fenproporex administration, but ω3 fatty acids reversed this damage only in the hippocampus. On the other hand, in the prevention model, fenproporex increased carbonyl content only in the cerebral cortex, and administration of ω3 fatty acids prevented this damage. Additionally, the administration of fenproporex resulted in a marked increased of TBARS in the prefrontal cortex, hippocampus, striatum and cerebral cortex, and prevent this damage in the prefrontal cortex, hippocampus and striatum. In conclusion, we are able to demonstrate that fenproporex-induced hyperlocomotion and damage through oxidative stress were prevented by ω3 fatty acids. Thus, the ω3 fatty acids may be important adjuvant therapy of bipolar disorder.
Noriyuki, Kushida; Hiroshi, Okuda; Genki, Yagawa
In this study, the thermal stress finite element analysis code optimized for the earth simulator was developed. A processor node of which of the earth simulator is the 8-way vector processor, and each processor can communicate using the message passing interface. Thus, there are two ways to parallelize the finite element method on the earth simulator. The first method is to assign one processor for one sub-domain, and the second method is to assign one node (=8 processors) for one sub-domain considering the shared memory type parallelization. Considering that the preconditioned conjugate gradient (PCG) method, which is one of the suitable linear equation solvers for the large-scale parallel finite element methods, shows the better convergence behavior if the number of domains is the smaller, we have determined to employ PCG and the hybrid parallelization, which is based on the shared and distributed memory type parallelization. It has been said that it is hard to obtain the good parallel or vector performance, since the finite element method is based on unstructured grids. In such situation, the reordering is inevitable to improve the computational performance . In this study, we used three reordering methods, i.e. Reverse Cuthil-McKee (RCM), cyclic multicolor (CM) and diagonal jagged descending storage (DJDS). RCM provides the good convergence of the incomplete lower-upper (ILU) PCG, but causes the load imbalance. On the other hand, CM provides the good load balance, but worsens the convergence of ILU PCG if the vector length is so long. Therefore, we used the combined-method of RCM and CM. DJDS is the method to store the sparse matrices such that longer vector length can be obtained. For attaining the efficient inter-node parallelization, such partitioning methods as the recursive coordinate bisection (RCM) or MeTIS have been used. Computational performance of the practical large-scale engineering problems will be shown at the meeting. (author)
Full Text Available Marijuana (MJ use is on the rise, particularly among teens and emerging adults. This poses serious public health concern, given the potential deleterious effects of MJ on the developing brain. We examined 50 chronic MJ smokers divided into early onset (regular MJ use prior to age 16; n = 24 and late onset (age 16 or later; n = 26, and 34 healthy control participants (HCs. All completed a modified Stroop Color Word Test during fMRI. Results demonstrated that MJ smokers exhibited significantly poorer performance on the Interference subtest of the Stroop, as well as altered patterns of activation in the cingulate cortex relative to HCs. Further, early onset MJ smokers exhibited significantly poorer performance relative to both HCs and late onset smokers. Additionally, earlier age of MJ onset as well as increased frequency and magnitude (grams/week of MJ use were predictive of poorer Stroop performance. fMRI results revealed that while late onset smokers demonstrated a more similar pattern of activation to the control group, a different pattern was evident in the early onset group. These findings underscore the importance of assessing age of onset and patterns of MJ use and support the need for widespread education and intervention efforts among youth.
Sharma, Shashi; Saxena, Sandeep; Srivastav, Khushboo; Shukla, Rajendra K; Mishra, Nibha; Meyer, Carsten H; Kruzliak, Peter; Khanna, Vinay K
The aim of the study was to determine plasma nitric oxide (NO) and lipid peroxide (LPO) levels in diabetic retinopathy and its association with severity of disease. Prospective observational study. A total of 60 consecutive cases and 20 healthy controls were included. Severity of retinopathy was graded according to early treatment diabetic retinopathy study (ETDRS) classification. Photoreceptor inner segment ellipsoid band (ISel) disruption and retinal pigment epithelium (RPE) alteration were graded using spectral domain optical coherence tomography. Data were statistically analyzed. Plasma thiobarbituric acid reactive substances, NO assay and reduced glutathione (GSH) were measured using standard protocol. Increased severity of diabetic retinopathy was significantly associated with increase in plasma levels of LPO (P diabetic retinopathy. For the first time, it has been demonstrated that increased plasma LPO, NO and decreased GSH levels are associated with in vivo structural changes in inner segment ellipsoid and RPE. © 2015 Royal Australian and New Zealand College of Ophthalmologists.
Chen, Guanliang; Zhang, Songbin; Jin, Yuanxiang; Wu, Yan; Liu, Ling; Qian, Haifeng; Fu, Zhengwei
Effects of triphenyl phosphate (TPP) and tris-(2-chloroethyl) phosphate (TCEP) exposure on induction of oxidative stress and endocrine disruption were investigated in TM3 cells. After 24h exposure, cell growth declined and morphology changed in TPP and TCEP treated groups with high dosages. Significant increases in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and glutathione S-transferase (GST) activities and their respective gene expressions in a dose-dependent and/or time-dependent manner in TPP or TCEP groups. Moreover, the expression of main genes related to testosterone (T) synthesis including cytochrome P450 cholesterol side-chain cleavage enzyme (P450scc), cytochrome P450 17α-hydroxysteroid dehydrogenase (P450-17α), 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase (17β-HSD) were dramatically reduced by TPP and TCEP treatments, especially with the high dosage for 24h. TPP and TCEP treatments for 24h caused significant decreases in T levels in the medium. Furthermore, co-treatments of hCG with TPP or TCEP could inhibit hCG-induced changes in the expression of P450scc, P450-17α and 17β-HSD and T levels. Taken together, TPP and TCEP could induce oxidative stress and endocrine disruption in TM3 cells. Copyright © 2015 Elsevier Inc. All rights reserved.
Lane, Richard D.; Reis, Harry T.; Peterson, Derick R.; Zareba, Wojciech; Moss, Arthur J.
Objective We sought to determine whether the circumstances preceding an arrhythmic event differed from those preceding a prior control occasion in patients with Long QT Syndrome (LQTS), a well-characterized genetically-based disorder that puts affected individuals at risk for sudden cardiac death. Methods 38 patients (89% female) with LQTS completed a “case-crossover interview” in which each patient served as his/her own control by reporting on circumstances preceding an arrhythmic event (syncope, aborted cardiac arrest or defibrillator discharge) and preceding a control occasion (the next-to-last birthday). On average the interview was conducted 17 months after the cardiac event and control occasion. Results During the 24-hour period preceding the cardiac event compared to the day before the control occasion, psychological stress was elevated, peak happiness was reduced, and peak exertion was not significantly different. Rated for the 6-month intervals preceding the event and control occasions, none of these three variables was significantly associated with events. Conclusions Happiness is associated with a reduction in the 24-hour risk of cardiac events in patients with LQTS, with stress having an opposite effect. To our knowledge this is the first report indicating that positive emotion may have a protective effect on life-threatening ventricular arrhythmias. This study lends further support to the role of emotions in influencing cardiac events in arrhythmia-prone patients. PMID:19419405
Kang, David S; Alcalay, Yehonatan; Lovin, Diane D; Cunningham, Joanne M; Eng, Matthew W; Chadee, Dave D; Severson, David W
In addition to genetic history, environmental conditions during larval stages are critical to the development, success and phenotypic fate of the Aedes aegypti mosquito. In particular, previous studies have shown a strong genotype-by-environment component to adult mosquito body size in response to optimal vs stressed larval conditions. Here, we expand upon those results by investigating the effects of larval-stage crowding and nutritional limitation on the susceptibility of a recent field isolate of Aedes aegypti to dengue virus serotype-2. Interestingly, female mosquitoes from larvae subjected to a stressed regime exhibited significantly reduced susceptibility to disseminated dengue infection 14days post infection compared to those subjected to optimal regimes. Short term survivorship post-infected blood feeding was not significantly different. As with body size, dengue virus susceptibility of a mosquito population is determined by a combination of genetic and environmental factors and is likely maintained by balancing selection. Here, we provide evidence that under different environmental conditions, the innate immune response of field-reared mosquitoes exhibits a large range of phenotypic variability with regard to dengue virus susceptibility. Further, as with body size, our results suggest that mosquitoes reared under optimal laboratory conditions, as employed in all mosquito-pathogen studies to date, may not always be realistic proxies for natural populations. Copyright © 2017 Elsevier B.V. All rights reserved.
Wilson, James W.; Ott, C. Mark; Ramamurthy, Rajee; Porwollik, Steffen; McClelland, Michael; Pierson, Duane L.; Nickerson, Cheryl A.
We have previously demonstrated that low-shear modeled microgravity (low-shear MMG) serves to enhance the virulence of a bacterial pathogen, Salmonella enterica serovar Typhimurium. The Salmonella response to low-shear MMG involves a signaling pathway that we have termed the low-shear MMG stimulon, though the identities of the low-shear MMG stimulon genes and regulatory factors are not known. RpoS is the primary sigma factor required for the expression of genes that are induced upon exposure to different environmental-stress signals and is essential for virulence in mice. Since low-shear MMG induces a Salmonella acid stress response and enhances Salmonella virulence, we reasoned that RpoS would be a likely regulator of the Salmonella low-shear MMG response. Our results demonstrate that low-shear MMG provides cross-resistance to several environmental stresses in both wild-type and isogenic rpoS mutant strains. Growth under low-shear MMG decreased the generation time of both strains in minimal medium and increased the ability of both strains to survive in J774 macrophages. Using DNA microarray analysis, we found no evidence of induction of the RpoS regulon by low-shear MMG but did find that other genes were altered in expression under these conditions in both the wild-type and rpoS mutant strains. Our results indicate that, under the conditions of these studies, RpoS is not required for transmission of the signal that induces the low-shear MMG stimulon. Moreover, our studies also indicate that low-shear MMG can be added to a short list of growth conditions that can serve to preadapt an rpoS mutant for resistance to multiple environmental stresses.
Matthews, Gerald; Warm, Joel S; Washburn, David
.... The research focuses especially on the measurement of cerebral bloodflow using transcranial doppler sonography, together with additional indices including salivary cortisol and subjective stress state...
Horak, Peter; Tomasich, Erwin; Vaňhara, Petr; Kratochvílová, Kateřina; Anees, Mariam; Marhold, Maximilian; Lemberger, Christof E.; Gerschpacher, Marion; Horvat, Reinhard; Sibilia, Maria; Pils, Dietmar; Krainer, Michael
Prostate cancer is the most prevalent cancer in males in developed countries. Tumor suppressor candidate 3 (TUSC3) has been identified as a putative tumor suppressor gene in prostate cancer, though its function has not been characterized. TUSC3 shares homologies with the yeast oligosaccharyltransferase (OST) complex subunit Ost3p, suggesting a role in protein glycosylation. We provide evidence that TUSC3 is part of the OST complex and affects N-linked glycosylation in mammalian cells. Loss of TUSC3 expression in DU145 and PC3 prostate cancer cell lines leads to increased proliferation, migration and invasion as well as accelerated xenograft growth in a PTEN negative background. TUSC3 downregulation also affects endoplasmic reticulum (ER) structure and stress response, which results in increased Akt signaling. Together, our findings provide first mechanistic insight in TUSC3 function in prostate carcinogenesis in general and N-glycosylation in particular.
Full Text Available Oxidative stress (OS is known to be strongly involved in a large number of fetal, neonatal, and adult diseases, including placental disorders, leading to pregnancy loss and stillbirths. A growing body of research links OS to preeclampsia, gestational diabetes, obesity, spontaneous abortion, recurrent pregnancy, preterm labor, and intrauterine growth restriction. While a considerable number of miRNAs have been related to physiological functions and pathological conditions of the placenta, a direct link among these miRNAs, placental functions, and OS is still lacking. This review summarizes data describing the role of miRNAs in placental pathophysiological processes and their possible impact on OS damaging responses. As miRNAs can be found in circulation, improving our understanding on their role in the pathogenesis of pregnancy related disorders could have an important impact on the diagnosis and prognosis of these diseases.
Pandey, Renu; Zinta, Gaurav; AbdElgawad, Hamada; Ahmad, Altaf; Jain, Vanita; Janssens, Ivan A
Atmospheric [CO2] has increased substantially in recent decades and will continue to do so, whereas the availability of phosphorus (P) is limited and unlikely to increase in the future. P is a non-renewable resource, and it is essential to every form of life. P is a key plant nutrient controlling the responsiveness of photosynthesis to [CO2]. Increases in [CO2] typically results in increased biomass through stimulation of net photosynthesis, and hence enhance the demand for P uptake. However, most soils contain low concentrations of available P. Therefore, low P is one of the major growth-limiting factors for plants in many agricultural and natural ecosystems. The adaptive responses of plants to [CO2] and P availability encompass alterations at morphological, physiological, biochemical and molecular levels. In general low P reduces growth, whereas high [CO2] enhances it particularly in C3 plants. Photosynthetic capacity is often enhanced under high [CO2] with sufficient P supply through modulation of enzyme activities involved in carbon fixation such as ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). However, high [CO2] with low P availability results in enhanced dry matter partitioning towards roots. Alterations in below-ground processes including root morphology, exudation and mycorrhizal association are influenced by [CO2] and P availability. Under high P availability, elevated [CO2] improves the uptake of P from soil. In contrast, under low P availability, high [CO2] mainly improves the efficiency with which plants produce biomass per unit P. At molecular level, the spatio-temporal regulation of genes involved in plant adaptation to low P and high [CO2] has been studied individually in various plant species. Genome-wide expression profiling of high [CO2] grown plants revealed hormonal regulation of biomass accumulation through complex transcriptional networks. Similarly, differential transcriptional regulatory networks are involved in P
Ormsbee, Michael J; Gorman, Katherine A; Miller, Elizabeth A; Baur, Daniel A; Eckel, Lisa A; Contreras, Robert J; Panton, Lynn B; Spicer, Maria T
The timing of morning endurance competition may limit proper pre-race fueling and resulting performance. A nighttime, pre-sleep nutritional strategy could be an alternative method to target the metabolic and hydrating needs of the early morning athlete without compromising sleep or gastrointestinal comfort during exercise. Therefore, the purpose of this investigation was to examine the acute effects of pre-sleep chocolate milk (CM) ingestion on next-morning running performance, metabolism, and hydration status. Twelve competitive female runners and triathletes (age, 30 ± 7 years; peak oxygen consumption, 53 ± 4 mL·kg(-1)·min(-1)) randomly ingested either pre-sleep CM or non-nutritive placebo (PL) ∼30 min before sleep and 7-9 h before a morning exercise trial. Resting metabolic rate (RMR) was assessed prior to exercise. The exercise trial included a warm-up, three 5-min incremental workloads at 55%, 65%, and 75% peak oxygen consumption, and a 10-km treadmill time trial (TT). Physiological responses were assessed prior, during (incremental and TT), and postexercise. Paired t tests and magnitude-based inferences were used to determine treatment differences. TT performances were not different ("most likely trivial" improvement with CM) between conditions (PL: 52.8 ± 8.4 min vs CM: 52.8 ± 8.0 min). RMR was "likely" increased (4.8%) and total carbohydrate oxidation (g·min(-1)) during exercise was "possibly" or likely increased (18.8%, 10.1%, 9.1% for stage 1-3, respectively) with CM versus PL. There were no consistent changes to hydration indices. In conclusion, pre-sleep CM may alter next-morning resting and exercise metabolism to favor carbohydrate oxidation, but effects did not translate to 10-km running performance improvements.
Sambataro, Fabio; Visintin, Eleonora; Doerig, Nadja; Brakowski, Janis; Holtforth, Martin Grosse; Seifritz, Erich; Spinelli, Simona
Major depressive disorder (MDD) has been associated with alterations in several functional brain networks. Previous studies investigating brain networks in MDD during the performance of a task have yielded inconsistent results with the function of the brain at rest. In this study, we used functional magnetic resonance imaging at rest and during a goal-directed task to investigate dynamics of functional connectivity in 19 unmedicated patients with MDD and 19 healthy controls across both experimental paradigms. Patients had spatial differences in the default mode network (DMN), in the executive network (EN), and in the dorsal attention network (DAN) compared to controls at rest and during task performance. In patients the amplitude of the low frequency (LFO) oscillations was reduced in the motor and in the DAN networks during both paradigms. There was a diagnosis by paradigm interaction on the LFOs amplitude of the salience network, with increased amplitude change between task and rest in patients relative to controls. Our findings suggest that the function of several networks could be intrinsically affected in MDD and this could be viable phenotype for the investigation on the neurobiological mechanisms of this disorder and its treatment. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.
Comim, Clarissa M; Gomes, Karin M; Réus, Gislaine Z; Petronilho, Fabrícia; Ferreira, Gabriela K; Streck, Emílio L; Dal-Pizzol, Felipe; Quevedo, João
To evaluate oxidative damage through the thiobarbituric acid-reactive species (TBARS) and protein carbonyl groups; antioxidant enzymatic system - superoxide dismutase (SOD) and catalase (CAT); and energetic metabolism in the brain of spontaneously hypertensive adult rats (SHR) after both acute and chronic treatment with methylphenidate hydrochloride (MPH). Adult (60 days old) SHRs were treated during 28 days (chronic treatment), or 1 day (acute treatment). The rats received one i.p. injection per day of either saline or MPH (2 mg/kg). Two hours after the last injection, oxidative damage parameters and energetic metabolism in the cerebellum, prefrontal cortex, hippocampus, striatum and cortex were evaluated. We observed that both acute and/or chronic treatment increased TBARS and carbonyl groups, and decreased SOD and CAT activities in many of the brain structures evaluated. Regarding the energetic metabolism evaluation, the acute and chronic treatment altered the energetic metabolism in many of the brain structures evaluated. We observed that both acute and chronic use of methylphenidate hydrochloride (MPH) in adult spontaneously hypertensive rats (SHRs) was associated with increased oxidative stress and energetic metabolism alterations. These data also reinforce the importance of the SHR animal model in further studies regarding MPH.
Full Text Available Venkat Keshav Chivukula,1 Benjamin L Krog,1,2 Jones T Nauseef,2 Michael D Henry,2 Sarah C Vigmostad1 1Department of Biomedical Engineering, 2Department of Molecular Physiology and Biophysics, Holden Comprehensive Cancer Center, University of Iowa, Seamans Center for the Engineering Arts and Sciences, Iowa City, IA, USA Abstract: Over 90% of cancer deaths result not from primary tumor development, but from metastatic tumors that arise after cancer cells circulate to distal sites via the circulatory system. While it is known that metastasis is an inefficient process, the effect of hemodynamic parameters such as fluid shear stress (FSS on the viability and efficacy of metastasis is not well understood. Recent work has shown that select cancer cells may be able to survive and possibly even adapt to FSS in vitro. The current research seeks to characterize the effect of FSS on the mechanical properties of suspended cancer cells in vitro. Nontransformed prostate epithelial cells (PrEC LH and transformed prostate cancer cells (PC-3 were used in this study. The Young's modulus was determined using micropipette aspiration. We examined cells in suspension but not exposed to FSS (unsheared and immediately after exposure to high (6,400 dyn/cm2 and low (510 dyn/cm2 FSS. The PrEC LH cells were ~140% stiffer than the PC-3 cells not exposed to FSS. Post-FSS exposure, there was an increase of ~77% in Young's modulus after exposure to high FSS and a ~47% increase in Young's modulus after exposure to low FSS for the PC-3 cells. There was no significant change in the Young's modulus of PrEC LH cells post-FSS exposure. Our findings indicate that cancer cells adapt to FSS, with an increased Young's modulus being one of the adaptive responses, and that this adaptation is specific only to PC-3 cells and is not seen in PrEC LH cells. Moreover, this adaptation appears to be graded in response to the magnitude of FSS experienced by the cancer cells. This is the first study
Bunpo, Piyawan; Anthony, Tracy G
The purpose of this study was to investigate the impact of ascorbic acid (AA) consumption on the oxidative stress status of untrained volunteers participating in a supervised exercise program. The study included 46 young adults (average age, 23.5 ± 0.59 years; 37 females, 9 males) who remained sedentary (n = 16) or participated in 30 min of outdoor aerobic running (n = 30) at an intensity corresponding to 65%-75% of maximum heart rate for 3 times per week for 12 weeks. Exercised subjects were randomly assigned to an exercise group without AA supplementation (control; n = 10) or received either 250 mg (n = 10) or 500 mg (n = 10) of AA supplementation previous to each exercise session. Blood samples were taken on day 0 and day 84 to evaluate metabolic profiles and antioxidant status. Sedentary subjects underwent in a single bout of aerobic running to determine total antioxidant status (TAS) and malondiadehyde (MDA) at pre- and postexercise with or without AA supplementation. No significant change in TAS was observed. Plasma MDA significantly increased at postexercise (P exercise, there was no significant change in blood glucose, lipid profile, MDA, TAS, superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase activities amongst groups. Supplementation of AA was associated with minor and inconsistent reductions in SOD, GPx, and catalase activities (P exercise supplementation of ascorbic acid does not alter oxidative stress markers in the plasma and erythrocytes of young adults engaged in a supervised exercise program.
3. Horvath, S. M. Exercise in a cold environment. Exercise Sport Sci. Rev. 4. Horvath, S. M., and R. L. Jackson. Significance of PSO under stress ...7 AD-AI3 010 CALIFORNIA UNIV SANTA BARBARA NST OP ENVIRONMENTAL --ETC F/6 6/19-7PHY IOL GICAL PERFORMANCE RELATED TO MULTIPLE STRESSES SUCH AS...Performance Related to Multiple Interim Scientific Report Stresses Such as Those Experienced in Air Force - 1//81-12/31/81 Operations 6. PERFORMING ORG
Conclusion: Perceived stress has negative direct relationship with social support and positive direct relationship with academic burnout. Social support also has positive direct relationship with academic performance. Relationship of maladaptive perfectionism with academic burnout and also the relationship of adaptive perfectionism with academic performance is direct positive. Relationship of perceived stress with academic performance is indirect mediated by social support.
Wafa, Tayeb; Nadia, Koubaa; Amel, Nakbi; Ikbal, Chaieb; Insaf, Tayeb; Asma, Kassab; Hedi, Miled Abdel; Mohamed, Hammami
In this study, a cohort of farmers from the Mateur region in the North of Tunisia, were interviewed and examined for the biochemical effects of pesticides. We studied their haematological profile, lipid parameters, serum markers of nephrotoxicity and hepatotoxicity. We also evaluated the activities of Butyrylcholinesterase (BChE), Acetylcholinesterase (AChE) and thiolactonase-paroxonase (PON). Moreover, lipid peroxidation and activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were determined. The duration of pesticide use and the farmers' age were considered in the analysis. Our results revealed significant differences in some haematological parameters, in liver and kidney functions, in the lipidic status of the pesticide-exposed group. We also reported an increase in the index of incidence of cardiovascular risk in farmer populations. A significant decrease in AChE, BChE and PON levels was found among farmers. Lipid peroxidation, however, increased. The activities of SOD and CAT were remarkably elevated in farmer populations. There was a significant relation between changes in biological markers, the duration of pesticide use and the farmers' age. This study indicates that a long-term exposure to pesticides may play an important role in the development of vascular diseases via metabolic disorders of lipoproteins, lipid peroxidation and oxidative stress, inhibition of BChE and decrease in thiolactonase-PON levels.
Vitousek, Maren N; Romero, L Michael; Tarlow, Elisa; Cyr, Nicole E; Wikelski, Martin
Island tameness is a widely documented phenomenon in which island species, particularly those that have evolved with no or few natural predators, show a greatly reduced behavioral response when faced with unfamiliar predators. This insufficient anti-predator response has led to widespread population declines among many island species exposed to novel predators, and has become a serious conservation problem. Despite its prevalence, the underlying physiology of island tameness is not known. Here we report that although Galápagos marine iguanas (Amblyrhynchus cristatus) initiated flight from an evolutionarily recent and unfamiliar potential predator (humans), they failed to show the cardiovascular stress response that facilitates successful escape, even after a prior capture experience. In contrast, when approached by a native predator (the Galápagos hawk; Buteo galapagoensis), marine iguanas show markedly increased heart rate independent of initiating escape movement. The secretion of catecholamines appears to be central to the initiation of escape behavior: naïve animals remotely injected with epinephrine immediately increased flight initiation distance, whereas those injected with corticosterone did not. Our results provide the first evidence that muted escape behavior in predator-naïve species is indicative of both a cognitive deficit in recognizing potential predators and a catecholamine deficit in response. Understanding how the response to predators differs in predator-naïve species could enable the design of maximally effective techniques for inducing an anti-predator response in these vulnerable species. (c) 2010 Elsevier Inc. All rights reserved.
Lopes Júnior, Cícero Alves; Barbosa, Herbert de Sousa; Moretto Galazzi, Rodrigo; Ferreira Koolen, Hector Henrique; Gozzo, Fábio Cesar; Arruda, Marco Aurélio Zezzi
The present study evaluates, at a proteomic level, changes in protein abundance in sunflower leaves in the absence or presence (at 50 or 700mg) of cadmium (as CdCl2). At the end of the cultivation period (45 days), proteins are extracted from leaves with phenol, separated by two-dimensional difference gel electrophoresis (2-D DIGE), and excised from the gels. The differential protein abundances (for proteins differing by more than 1.8 fold, which corresponds to 90% variation) are characterized using nESI-LC-MS/MS. The protein content decreases by approximately 41% in plants treated with 700mg Cd compared with control plants. By comparing all groups of plants evaluated in this study (Control vs. Cd-lower, Control vs. Cd-higher and Cd-lower vs. Cd-higher), 39 proteins are found differential and 18 accurately identified; the control vs. Cd-higher treatment is that presenting the most differential proteins. From identified proteins, those involved in energy and disease/defense (including stress), are the ribulose bisphosphate carboxylase large chain, transketolase, and heat shock proteins are the most differential abundant proteins. Thus, at the present study, photosynthesis is the main process affected by Cd in sunflowers, although these plants are highly tolerant to Cd. Copyright © 2015 Elsevier Inc. All rights reserved.
Otabi, Hikari; Goto, Tatsuhiko; Okayama, Tsuyoshi; Kohari, Daisuke; Toyoda, Atsushi
Behavioral and physiological evaluations of animal models of depression are essential to thoroughly understand the mechanisms of depression in humans. Various models have been developed and characterized, and the socially defeated mouse has been widely used for studying depression. Here, we developed and characterized a mouse model of social aversion using a subchronic and mild social defeat stress (sCSDS) paradigm. Compared to control mice, sCSDS mice showed significantly increased body weight gain, water intake, and social aversion to dominant mice on the social interaction test. We observed nest building behavior in sCSDS mice using the pressed cotton as a nest material. Although sCSDS mice eventually successfully built nests, the onset of nest building was severely delayed compared to control mice. The underlying mechanism of this significant delay in nest building by sCSDS mice is unclear. However, our results demonstrate that nest building evaluation is a simple and useful assay for understanding behavior in socially defeated mice and screening drugs such as antidepressants. Copyright © 2015 Elsevier B.V. All rights reserved.
Mina, Sara G; Huang, Peter; Murray, Bruce T; Mahler, Gretchen J
Tumor development is influenced by stromal cells in aspects including invasion, growth, angiogenesis, and metastasis. Activated fibroblasts are one group of stromal cells involved in cancer metastasis, and one source of activated fibroblasts is endothelial to mesenchymal transformation (EndMT). EndMT begins when the endothelial cells delaminate from the cell monolayer, lose cell-cell contacts, lose endothelial markers such as vascular endothelial-cadherin (VE-cadherin), gain mesenchymal markers like alpha-smooth muscle actin (α-SMA), and acquire mesenchymal cell-like properties. A three-dimensional (3D) culture microfluidic device was developed for investigating the role of steady low shear stress (1 dyne/cm 2 ) and altered extracellular matrix (ECM) composition and stiffness on EndMT. Shear stresses resulting from fluid flow within tumor tissue are relevant to both cancer metastasis and treatment effectiveness. Low and oscillatory shear stress rates have been shown to enhance the invasion of metastatic cancer cells through specific changes in actin and tubulin remodeling. The 3D ECM within the device was composed of type I collagen and glycosaminoglycans (GAGs), hyaluronic acid and chondroitin sulfate. An increase in collagen and GAGs has been observed in the solid tumor microenvironment and has been correlated with poor prognosis in many different cancer types. In this study, it was found that ECM composition and low shear stress upregulated EndMT, including upregulation of mesenchymal-like markers (α-SMA and Snail) and downregulated endothelial marker protein and gene expression (VE-cadherin). Furthermore, this novel model was utilized to investigate the role of EndMT in breast cancer cell proliferation and migration. Cancer cell spheroids were embedded within the 3D ECM of the microfluidic device. The results using this device show for the first time that the breast cancer spheroid size is dependent on shear stress and that the cancer cell migration rate
Nilsson-Örtman, Viktor; Johansson, Frank
How the ability to acclimate will impact individual performance and ecological interactions under climate change remains poorly understood. Theory predicts that the benefit an organism can gain from acclimating depends on the rate at which temperatures change relative to the time it takes to induce beneficial acclimation. Here, we present a conceptual model showing how slower seasonal changes under climate change can alter species' relative performance when they differ in acclimation rate and magnitude. To test predictions from theory, we performed a microcosm experiment where we reared a mid- and a high-latitude damselfly species alone or together under the rapid seasonality currently experienced at 62°N and the slower seasonality predicted for this latitude under climate change and measured larval growth and survival. To separate acclimation effects from fixed thermal responses, we simulated growth trajectories based on species' growth rates at constant temperatures and quantified how much and how fast species needed to acclimate to match the observed growth trajectories. Consistent with our predictions, the results showed that the midlatitude species had a greater capacity for acclimation than the high-latitude species. Furthermore, since acclimation occurred at a slower rate than seasonal temperature changes, the midlatitude species had a small growth advantage over the high-latitude species under the current seasonality but a greater growth advantage under the slower seasonality predicted for this latitude under climate change. In addition, the two species did not differ in survival under the current seasonality, but the midlatitude species had higher survival under the predicted climate change scenario, possibly because rates of cannibalism were lower when smaller heterospecifics were present. These findings highlight the need to incorporate acclimation rates in ecological models.
Full Text Available We have previously reported that acetylsalicylic acid (aspirin, ASA induces cell cycle arrest, oxidative stress and mitochondrial dysfunction in HepG2 cells. In the present study, we have further elucidated that altered glutathione (GSH-redox metabolism in HepG2 cells play a critical role in ASA-induced cytotoxicity. Using selected doses and time point for ASA toxicity, we have demonstrated that when GSH synthesis is inhibited in HepG2 cells by buthionine sulfoximine (BSO, prior to ASA treatment, cytotoxicity of the drug is augmented. On the other hand, when GSH-depleted cells were treated with N-acetyl cysteine (NAC, cytotoxicity/apoptosis caused by ASA was attenuated with a significant recovery in oxidative stress, GSH homeostasis, DNA fragmentation and some of the mitochondrial functions. NAC treatment, however, had no significant effects on the drug-induced inhibition of mitochondrial aconitase activity and ATP synthesis in GSH-depleted cells. Our results have confirmed that aspirin increases apoptosis by increased reactive oxygen species production, loss of mitochondrial membrane potential and inhibition of mitochondrial respiratory functions. These effects were further amplified when GSH-depleted cells were treated with ASA. We have also shown that some of the effects of aspirin might be associated with reduced GSH homeostasis, as treatment of cells with NAC attenuated the effects of BSO and aspirin. Our results strongly suggest that GSH dependent redox homeostasis in HepG2 cells is critical in preserving mitochondrial functions and preventing oxidative stress associated complications caused by aspirin treatment.
Raza, Haider; John, Annie
We have previously reported that acetylsalicylic acid (aspirin, ASA) induces cell cycle arrest, oxidative stress and mitochondrial dysfunction in HepG2 cells. In the present study, we have further elucidated that altered glutathione (GSH)-redox metabolism in HepG2 cells play a critical role in ASA-induced cytotoxicity. Using selected doses and time point for ASA toxicity, we have demonstrated that when GSH synthesis is inhibited in HepG2 cells by buthionine sulfoximine (BSO), prior to ASA treatment, cytotoxicity of the drug is augmented. On the other hand, when GSH-depleted cells were treated with N-acetyl cysteine (NAC), cytotoxicity/apoptosis caused by ASA was attenuated with a significant recovery in oxidative stress, GSH homeostasis, DNA fragmentation and some of the mitochondrial functions. NAC treatment, however, had no significant effects on the drug-induced inhibition of mitochondrial aconitase activity and ATP synthesis in GSH-depleted cells. Our results have confirmed that aspirin increases apoptosis by increased reactive oxygen species production, loss of mitochondrial membrane potential and inhibition of mitochondrial respiratory functions. These effects were further amplified when GSH-depleted cells were treated with ASA. We have also shown that some of the effects of aspirin might be associated with reduced GSH homeostasis, as treatment of cells with NAC attenuated the effects of BSO and aspirin. Our results strongly suggest that GSH dependent redox homeostasis in HepG2 cells is critical in preserving mitochondrial functions and preventing oxidative stress associated complications caused by aspirin treatment.
Yiu Chung Tse
Full Text Available Stress exerts a profound impact on learning and memory, in part, through the actions of adrenal corticosterone (CORT on synaptic plasticity, a cellular model of learning and memory. Increasing findings suggest that CORT exerts its impact on synaptic plasticity by altering the functional properties of glutamate receptors, which include changes in the motility and function of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid subtype of glutamate receptor (AMPAR that are responsible for the expression of synaptic plasticity. Here we provide evidence that CORT could also regulate synaptic plasticity by modulating the function of synaptic N-methyl-D-aspartate receptors (NMDARs, which mediate the induction of synaptic plasticity. We found that stress level CORT applied to adult rat hippocampal slices potentiated evoked NMDAR-mediated synaptic responses within 30 min. Surprisingly, following this fast-onset change, we observed a slow-onset (>1 hour after termination of CORT exposure increase in synaptic expression of GluN2A-containing NMDARs. To investigate the consequences of the distinct fast- and slow-onset modulation of NMDARs for synaptic plasticity, we examined the formation of long-term potentiation (LTP and long-term depression (LTD within relevant time windows. Paralleling the increased NMDAR function, both LTP and LTD were facilitated during CORT treatment. However, 1-2 hours after CORT treatment when synaptic expression of GluN2A-containing NMDARs is increased, bidirectional plasticity was no longer facilitated. Our findings reveal the remarkable plasticity of NMDARs in the adult hippocampus in response to CORT. CORT-mediated slow-onset increase in GluN2A in hippocampal synapses could be a homeostatic mechanism to normalize synaptic plasticity following fast-onset stress-induced facilitation.
Full Text Available Mammalian bile acids (BAs are oxidized metabolites of cholesterol whose amphiphilic properties serve in lipid and cholesterol uptake. BAs also act as hormone-like substances that regulate metabolism. The Caenorhabditis elegans clk-1 mutants sustain elevated mitochondrial oxidative stress and display a slow defecation phenotype that is sensitive to the level of dietary cholesterol. We found that: 1 The defecation phenotype of clk-1 mutants is suppressed by mutations in tat-2 identified in a previous unbiased screen for suppressors of clk-1. TAT-2 is homologous to ATP8B1, a flippase required for normal BA secretion in mammals. 2 The phenotype is suppressed by cholestyramine, a resin that binds BAs. 3 The phenotype is suppressed by the knock-down of C. elegans homologues of BA-biosynthetic enzymes. 4 The phenotype is enhanced by treatment with BAs. 5 Lipid extracts from C. elegans contain an activity that mimics the effect of BAs on clk-1, and the activity is more abundant in clk-1 extracts. 6 clk-1 and clk-1;tat-2 double mutants show altered cholesterol content. 7 The clk-1 phenotype is enhanced by high dietary cholesterol and this requires TAT-2. 8 Suppression of clk-1 by tat-2 is rescued by BAs, and this requires dietary cholesterol. 9 The clk-1 phenotype, including the level of activity in lipid extracts, is suppressed by antioxidants and enhanced by depletion of mitochondrial superoxide dismutases. These observations suggest that C. elegans synthesizes and secretes molecules with properties and functions resembling those of BAs. These molecules act in cholesterol uptake, and their level of synthesis is up-regulated by mitochondrial oxidative stress. Future investigations should reveal whether these molecules are in fact BAs, which would suggest the unexplored possibility that the elevated oxidative stress that characterizes the metabolic syndrome might participate in disease processes by affecting the regulation of metabolism by BAs.
Full Text Available Patients with Panic Disorder (PD direct their attention towards potential threat, followed by panic attacks, and increased sweat production. Onés own anxiety sweat odor influences the attentional focus, and discrimination of threat or non-threat. Since olfactory projection areas overlap with neuronal areas of a panic-specific fear network, the present study investigated the neuronal processing of odors in general and of stress-related sweat odors in particular in patients with PD.A sample of 13 patients with PD with/ without agoraphobia and 13 age- and gender-matched healthy controls underwent an fMRI investigation during olfactory stimulation with their stress-related sweat odors (TSST, ergometry as well as artificial odors (peach, artificial sweat as non-fearful non-body odors.The two groups did not differ with respect to their olfactory identification ability. Independent of the kind of odor, the patients with PD showed activations in fronto-cortical areas in contrast to the healthy controls who showed activations in olfaction-related areas such as the amygdalae and the hippocampus. For artificial odors, the patients with PD showed a decreased neuronal activation of the thalamus, the posterior cingulate cortex and the anterior cingulate cortex. Under the presentation of sweat odor caused by ergometric exercise, the patients with PD showed an increased activation in the superior temporal gyrus, the supramarginal gyrus, and the cingulate cortex which was positively correlated with the severity of the psychopathology. For the sweat odor from the anxiety condition, the patients with PD showed an increased activation in the gyrus frontalis inferior, which was positively correlated with the severity of the psychopathology.The results suggest altered neuronal processing of olfactory stimuli in PD. Both artificial odors and stress-related body odors activate specific parts of a fear-network which is associated with an increased severity of the
Eckart, Cindy; Stoppel, Christian; Kaufmann, Jörn; Tempelmann, Claus; Hinrichs, Hermann; Elbert, Thomas; Heinze, Hans-Jochen; Kolassa, Iris-Tatjana
So far, the neural network associated with posttraumatic stress disorder (PTSD) has been suggested to mainly involve the amygdala, hippocampus and medial prefrontal cortex. However, increasing evidence indicates that cortical regions extending beyond this network might also be implicated in the pathophysiology of PTSD. We aimed to investigate PTSD-related structural alterations in some of these regions. We enrolled highly traumatized refugees with and without (traumatized controls) PTSD and nontraumatized controls in the study. To increase the validity of our results, we combined an automatic cortical parcellation technique and voxel-based morphometry. In all, 39 refugees (20 with and 19 without PTSD) and 13 controls participated in the study. Participants were middle-aged men who were free of psychoactive substances and consumed little to no alcohol. Patients with PTSD (and to a lesser extent traumatized controls) showed reduced volumes in the right inferior parietal cortex, the left rostral middle frontal cortex, the bilateral lateral orbitofrontal cortex and the bilateral isthmus of the cingulate. An influence of cumulative traumatic stress on the isthmus of the cingulate and the lateral orbitofrontal cortex indicated that, at least in these regions, structural alterations might be associated with repeated stress experiences. Voxel-based morphometry analyses produced largely consistent results, but because of a poorer signal-to-noise ratio, conventional statistics did not reach significance. Although we controlled for several important confounding variables (e.g., sex, alcohol abuse) with our particular sample, this might limit the generalizibility of our data. Moreover, high comorbidity of PTSD and major depression hinders a definite separation of these conditions in our findings. Finally, the results concerning the lateral orbito frontal cortex should be interpreted with caution, as magnetic resonance imaging acquisition in this region is affected by a general
Inam, Qurrat-ul-Aen; Shireen, Erum; Haider, Saida; Haleem, Darakhshan Jabeen
Examination stress is a psychological stress that activate hypothalamic-pituitary adrenocortical (HPA) axis to increase circulating levels of glucocorticoids. The fat derived hormone leptin is also released in response to stress-inducing condition. To workout the role of leptin and cortisol in response to perceived levels of examination stress and their effects on academic performance. The present study was designed to monitor the relationship of self reported perceived levels of examination stress on serum levels of cortisol and leptin in female students going to appear in university examination. Fifty-six female undergraduate students participated in the study. Examination stress, appetite levels were assessed by a questionnaire and blood samples were collected one hour before appearing in the examination. Performance was evaluated from the marks obtained in that particular examination. Serum cortisol levels increased with an increase in the intensity of perceived examination stress. Serum leptin levels increased only in the group under moderate stress while increases in mild and severe stress group were not significant. Mild to moderate stress enhanced performance but severe stress decreased it. The present study shows an inverted U-shaped relationship between self reported different levels of perceived examination stress and academic performance.
Khanehkeshi, Ali; Basavarajappa
This paper investigates the relationship of academic stress with aggression, depression and academic performance of college students. Using a random sampling technique, 60 students consist of boys and girls were selected as students having academic stress. The scale for assessing academic stress (Sinha, Sharma and Mahendra, 2001); the Buss-Perry…
Full Text Available A new method was developed to apply pull-and-shear loads to the bolt specimen in order to evaluate the anchorage performance of the rebar bolt and the D-Bolt. In the tests, five displacing angles (0°, 20°, 40°, 60°, and 90°, two joint gaps (0 mm and 30 mm, and three kinds of host rock materials (weak concrete, strong concrete, and concrete-granite were considered, and stress–strain measurements were conducted. Results show that the ultimate loads of both the D-Bolt and the rebar bolt remained constant with any displacing angles. The ultimate displacement of the D-Bolt changed from 140 mm at the 0° displacing angle (pure pull to approximately 70 mm at a displacing angle greater than 40°. The displacement capacity of the D-Bolt is approximately 3.5 times that of the rebar bolt under pure pull and 50% higher than that of the rebar bolt under pure shear. The compressive stress exists at 50 mm from the bolt head, and the maximum bending moment value rises with the increasing displacing angle. The rebar bolt mobilises greater applied load than the D-Bolt when subjected to the maximum bending. The yielding length (at 0° of the D-Bolt is longer than that of the rebar bolt. The displacement capacity of the bolts increased with the joint gap. The bolt subjected to joint gap effect yields more quickly with greater bending moment and smaller applied load. The displacement capacities of the D-Bolt and the rebar bolt are greater in the weak host rock than that in the hard host rock. In pure shear condition, the ultimate load of the bolts slightly decreases in the hard rock. The yielding speed in the hard rock is higher than that in the weak rock.
Shen, Haitao; Wu, Na; Wang, Yu; Zhao, Hongyu; Zhang, Lichun; Li, Tiegang; Zhao, Min
Paraquat is one of the most extensively used herbicides and has high toxicity for humans and animals. However, there is no effective treatment for paraquat poisoning. The aim of the present study was to evaluate the effects of chloroquine on paraquat-induced lung injury in mice. Mice received a single intraperitoneal injection of paraquat and a daily intraperitoneal injection of the indicated dosages of chloroquine or dexamethasone. The histological changes, inflammation and oxidative stress in the lungs were examined at day 3, and the degree of pulmonary fibrosis was examined at day 28. H&E staining showed that chloroquine markedly attenuated lung injury induced by paraquat. In addition, the inflammatory responses induced by paraquat were inhibited after treatment with chloroquine, as indicated by the decreased number of leukocytes, the reduced levels of TNF-α, IL-1β and IL-6 in the bronchoalveolar lavage fluid, the reduced NO content, and downregulation of iNOS expression in lung tissues. No different effect was found between high-dose chloroquine and dexamethasone. Additionally, the treatment with chloroquine increased the activity of SOD and decreased the level of MDA in the lung tissues. The expressions of the anti-oxidative proteins, Nrf2, HO-1 and NQO1, were also upregulated by chloroquine treatment. The high-dose chloroquine was more effective than dexamethasone in its anti-oxidation ability. Finally, the results of Masson's staining illustrated that chloroquine markedly attenuated fibrosis in the paraquat-exposed lungs. Immunohistochemistry staining showed that the expressions of the pro-fibrotic proteins TGF-β and α-SMA were downregulated after treatment with chloroquine. In conclusion, chloroquine effectively attenuated paraquat-induced lung injury in mice. Copyright © 2017 Elsevier B.V. All rights reserved.
Full Text Available Iron stress is a major stress factor in irrigated rice. The complete mechanism underlying iron metabolism andtransport is still unknown. Irrigated rice (Oryza sativa L. cultivars were exposed to Fe2+ stress in hydroponic conditions,aiming to assess genotype performance under stress as well as to develop a protocol for genotype selection. The experimentaldesign was completely randomized, using a triple factorial scheme 2 x 5 x 6 (time x dose x genotype. The trait shoot length andnine days under stress were favorable for genotype discrimination under iron stress. The genotypes BR IRGA 409 and BRSAGRISUL were, respectively, the most sensitive and tolerant genotypes to iron stress. According to the genotype performance,hydroponics can be recommended as an efficient cultivation technique for the selection of iron stress-tolerant rice genotypes.
Huang, Peng; Zhang, Tengxiao; Miao, Danmin; Zhu, Xia
Background To examine Chinese soldiers’ acute stress responses, we did this study. Methods The soldiers completed the Acute Stress Response Scale (ASRS) when engaged in major tasks, such as earthquake rescue in Wenchuan, Sichuan, and maintaining social stability in Urumchi, Xinjiang. The ASRS has good reliability and validity. The study enrolled 1,832 male soldiers. Results The results showed significant differences among five dimensions and the overall response index when comparing four dive...
Maraisa Crestani; José Antonio Gonzalez da Silva; Velci Queiróz de Souza; Irineu Hartwig; Henrique de Souza Luche; Rogério Oliveira de Sousa; Fernando Irajá Félix de Carvalho; Antonio Costa de Oliveira
Iron stress is a major stress factor in irrigated rice. The complete mechanism underlying iron metabolism andtransport is still unknown. Irrigated rice (Oryza sativa L.) cultivars were exposed to Fe2+ stress in hydroponic conditions,aiming to assess genotype performance under stress as well as to develop a protocol for genotype selection. The experimentaldesign was completely randomized, using a triple factorial scheme 2 x 5 x 6 (time x dose x genotype). The trait shoot length andnine days un...
Ramlani Lina Sinaulan
Performance is a form of behavior of a person or organization with achievement orientation. The study results are known (a) the school climate affect performance of teachers, b) there is influence of work stress on teacher performance, (c) work motivation effect on teacher performance, d) school climate influence on job motivation of teachers, and (e) work stress effect on work motivation of teachers. Suggestions studies (a) improving teacher performance should the top priority schools in sch...
After having recalled some aspects of radiobiology (effects of ionizing radiations, molecular targets of radiations, cellular responses with respect to the radiation), the author discusses various aspects of radio-sensitivity: intrinsic radio-sensitivity of tumoral and normal cells, DNA injuries and in vitro radio-sensitivity, genes of susceptibility to ionizing radiations, clustered injuries. Then she reports investigations performed by infrared micro-spectroscopy: characterization of pathological lines, of biological processes, of oxidative injuries induced by xenobiotics, of injuries induced by ionizing radiations
O'Brien, Katharine R; McAbee, Samuel T; Hebl, Michelle R; Rodgers, John R
The present study examines the consequences of perceived interpersonal discrimination on stress, health, and performance in a sample of 210 science, technology, engineering, and mathematics (STEM) academicians. Using a path model, we test the relation that perceived interpersonal discrimination has on stress and the relation of stress to physical health maladies and on current and future performance. In so doing, we assess the link between discrimination and decrements in performance over time. Additionally, we test supervisor social support as a moderator of the discrimination-stress relation. Findings support relations between perceived interpersonal discrimination and stress, which in turn relates to declines in physical health and performance outcomes. Moreover, supervisory support is shown to mitigate the influence of interpersonal discrimination on stress in STEM academicians.
O’Brien, Katharine R.; McAbee, Samuel T.; Hebl, Michelle R.; Rodgers, John R.
The present study examines the consequences of perceived interpersonal discrimination on stress, health, and performance in a sample of 210 science, technology, engineering, and mathematics (STEM) academicians. Using a path model, we test the relation that perceived interpersonal discrimination has on stress and the relation of stress to physical health maladies and on current and future performance. In so doing, we assess the link between discrimination and decrements in performance over time. Additionally, we test supervisor social support as a moderator of the discrimination–stress relation. Findings support relations between perceived interpersonal discrimination and stress, which in turn relates to declines in physical health and performance outcomes. Moreover, supervisory support is shown to mitigate the influence of interpersonal discrimination on stress in STEM academicians. PMID:27199848
Liiv, Helena; Jurimae, Toivo; Klonova, Alina; Cicchella, Antonio
Like other athletes, ballroom dancers often compete in short time in different countries under condition of high stress, subjecting them to risk of injury and burnout. In the present study, we measured the aerobic and anaerobic capacities (both during dance and during a simulated ballroom competition), agility, hand and abdominal strength, jumping capacity, flexibility, and balance in 16 top-level couples of ballroom dancers (8 males, 8 females). The in-season level of perceived stress and recovery was assessed using the Rest Q 76 questionnaire, and the relationship with aerobic and anaerobic capacity and with the other tests was studied. Our results show a very high level of aerobic/anaerobic fitness in this population, as well as a high level of stress in males. Balance and experience (age of the subjects) appear to be key characteristics linked to the position in the IDSF World Ranking (world ranking points = 8.67 x age + 5.86 x balance + 1174.65; R2 = 0.740). Emotional stress (r = 0.83, p = 0.04), social stress (r = 0.72, p = 0.032), and sleep quality (r = 0.92, p = 0.001) scales of the Rest Q appear also to be linked with balance but only in females.
Kötter, Thomas; Wagner, Josefin; Brüheim, Linda; Voltmer, Edgar
Medical students are exposed to high amounts of stress. Stress and poor academic performance can become part of a vicious circle. In order to counteract this circularity, it seems important to better understand the relationship between stress and performance during medical education. The most widespread stress questionnaire designed for use in Medical School is the "Perceived Medical School Stress Instrument" (PMSS). It addresses a wide range of stressors, including workload, competition, social isolation and financial worries. Our aim was to examine the relation between the perceived Medical School stress of undergraduate medical students and academic performance. We measured Medical School stress using the PMSS at two different time points (at the end of freshman year and at the end of sophomore year) and matched stress scores together with age and gender to the first medical examination (M1) grade of the students (n = 456). PMSS scores from 2 and 14 months before M1 proved to be significant predictors for medical students' M1 grade. Age and gender also predict academic performance, making older female students with high stress scores a potential risk group for entering the vicious circle of stress and poor academic performance. PMSS sum scores 2 and 14 months before the M1 exam seem to have an independent predictive validity for medical students' M1 grade. More research is needed to identify potential confounders.
Harkema Jack R
Full Text Available Abstract Background Prior studies have demonstrated a link between air pollution and metabolic diseases such as type II diabetes. Changes in adipose tissue and its mitochondrial content/function are closely associated with the development of insulin resistance and attendant metabolic complications. We investigated changes in adipose tissue structure and function in brown and white adipose depots in response to chronic ambient air pollutant exposure in a rodent model. Methods Male ApoE knockout (ApoE-/- mice inhaled concentrated fine ambient PM (PM 2.5 or filtered air (FA for 6 hours/day, 5 days/week, for 2 months. We examined superoxide production by dihydroethidium staining; inflammatory responses by immunohistochemistry; and changes in white and brown adipocyte-specific gene profiles by real-time PCR and mitochondria by transmission electron microscopy in response to PM2.5 exposure in different adipose depots of ApoE-/- mice to understand responses to chronic inhalational stimuli. Results Exposure to PM2.5 induced an increase in the production of reactive oxygen species (ROS in brown adipose depots. Additionally, exposure to PM2.5 decreased expression of uncoupling protein 1 in brown adipose tissue as measured by immunohistochemistry and Western blot. Mitochondrial number was significantly reduced in white (WAT and brown adipose tissues (BAT, while mitochondrial size was also reduced in BAT. In BAT, PM2.5 exposure down-regulated brown adipocyte-specific genes, while white adipocyte-specific genes were differentially up-regulated. Conclusions PM2.5 exposure triggers oxidative stress in BAT, and results in key alterations in mitochondrial gene expression and mitochondrial alterations that are pronounced in BAT. We postulate that exposure to PM2.5 may induce imbalance between white and brown adipose tissue functionality and thereby predispose to metabolic dysfunction.
Harris, Breanna N; de Jong, Trynke R; Yang, Vanessa; Saltzman, Wendy
Stress and chronically elevated glucocorticoid levels have been shown to disrupt parental behavior in mothers; however, almost no studies have investigated corresponding effects in fathers. The present experiment tested the hypothesis that chronic variable stress inhibits paternal behavior and consequently alters pup development in the monogamous, biparental California mouse (Peromyscus californicus). First-time fathers were assigned to one of three experimental groups: chronic variable stress (CVS, n=8), separation control (SC, n=7), or unmanipulated control (UC, n=8). The CVS paradigm (3 stressors per day for 7 days) successfully stressed mice, as evidenced by increased baseline plasma corticosterone concentrations, increased adrenal mass, decreased thymus mass, and a decrease in body mass over time. CVS altered paternal and social behavior of fathers, but major differences were observed only on day 6 of the 7-day paradigm. At that time point, CVS fathers spent less time with their pairmate and pups, and more time autogrooming, as compared to UC fathers; SC fathers spent more time behaving paternally and grooming the female mate than CVS and UC fathers. Thus, CVS blocked the separation-induced increase in social behaviors observed in the SC fathers. Nonetheless, chronic stress in fathers did not appear to alter survival or development of their offspring: pups from the three experimental conditions did not differ in body mass gain over time, in the day of eye opening, or in basal or post-stress corticosterone levels. These results demonstrate that chronic stress can transiently disrupt paternal and social behavior in P. californicus fathers, but does not alter pup development or survival under controlled, non-challenging laboratory conditions. © 2013.
LePine, Jeffrey A.; LePine, Marcie A.; Jackson, Christine L.
In a study of 696 learners, the authors found that stress associated with challenges in the learning environment had a positive relationship with learning performance and that stress associated with hindrances in the learning environment had a negative relationship with learning performance. They also found evidence suggesting that these…
Cheng, Vivienne; Catling, Jonathan
Transition to university is an important and potentially stressful life event for students. Previous studies have shown that resilience, delay of gratification and stress can affect the academic performance of students. However, none have shown the effect of these factors in predicting academic performance, hence the current study aimed to look at…
van der Does, H. T. D.; Brink, M. S.; Visscher, C.; Huijgen, B. C. H.; Frencken, W. G. P.; Lemmink, K. A. P. M.
Physical and psychosocial stress and recovery are important performance determinants. A holistic approach that monitors these performance determinants over a longer period of time is lacking. Therefore this study aims to investigate the effect of a player's physical and psychosocial stress and
Suandi, Turiman; Ismail, Ismi Arif; Othman, Zulfadli
This research aims at finding out the relationship between Organizational Climate, job stress and job performance among State Education Department (JPN) officers . The focus of the research is to determine the job performance of state education department officers, level of job stress among the officers, level of connection between organizational…
Sonoda, Yukio; Onozuka, Daisuke; Hagihara, Akihito
To evaluate operating room nurses' perception of teamwork performance and their level of mental stress and to identify related factors. Little is known about the factors affecting teamwork and the mental stress of surgical nurses, although the performance of the surgical team is essential for patient safety. The questionnaire survey for operation room nurses consisted of simple questions about teamwork performance and mental stress. Multivariate analyses were used to identify factors causing a sense of teamwork performance or mental stress. A large number of surgical nurses had a sense of teamwork performance, but 30-40% of operation room nurses were mentally stressed during surgery. Neither the patient nor the operation factors were related to the sense of teamwork performance in both types of nurses. Among scrub nurses, endoscopic and abdominal surgery, body mass index, blood loss and the American Society of Anesthesiologists physical status class were related to their mental stress. Conversely, circulating nurses were stressed about teamwork performance. The factors related to teamwork performance and mental stress during surgery differed between scrub and circulating nurses. Increased support for operation room nurses is necessary. The increased support leads to safer surgical procedures and better patient outcomes. © 2017 John Wiley & Sons Ltd.
Acrolein is an irritating aldehyde generated during combustion of organic compounds. Altered autonomic activity has been documented following acrolein inhalation, possibly impacting myocardial synchrony and function. Given the ubiquitous nature of acrolein in the environment, we ...
Full Text Available The objective of the present study was to evaluate academic stress, social support and their relationships with mental health and academic performance in university students. Three hundred and twenty one students from a technological university in Caracas, Venezuela, responded instruments on academic stress, social support and mental health during the most academically stressful period. The results indicate that favorable conditions of mental health were associated to more social support and less academic stress. In women, higher stress levels were associated to a lesser amount of social support from friends whereas in men stress was related to less social support coming from close people and general social support. Both displayed better performance when perceived higher levels of academic stress and the social support of the near people was moderate. Results are discussed in terms of their implications for academic life and mental health in university students.
Kumar, Mukesh; Sharma, Sachin; Gupta, Surbhi; Vaish, Supriya; Misra, Rajesh
Stress, a universal phenomenon, affects an individual's productivity either by increasing it ('eustress') or decreasing it ('distress'). It is widely acknowledged that the medical fraternity is predisposed to enormous stress. The same may be true for the budding medicos- the undergraduate medical students. In our study we attempted to identify situations that predisposed the medical students to stress and their effects on academic performance and to suggest certain coping mechanisms. firstly to explore common sources of stress in medical students, secondly to establish correlation of stress, gender, attendance, and academic performance if any. 114 medical undergraduates were assessed for the common sources of stress and the level of stress using semi structured Performa and stress scale. The results were compared and correlated with various variables like attendance, demographic factors, average marks etc. Pearson correlation coefficient was used for statistical correlation amongst different variables. Stress shows beneficial effects in females when compared to males. High attendance and better day to day performance in female medical students was associated with more amount of stress when compared to male students. Thus, stress among medical students should be acknowledged and attempts should be made to alleviate it.
Hogarth, Kaley A; Costford, Sheila R; Yoon, Grace; Sondheimer, Neal; Maynes, Jason T
Mitochondria play vital roles in brain development and neuronal activity, and mitochondrial dynamics (fission and fusion) maintain organelle function through the removal of damaged components. Dynamin-like protein-1 (DRP-1), encoded by DNM1L, is an evolutionarily conserved GTPase that mediates mitochondrial fission by surrounding the scission site in concentric ring-like structures via self-oligomerization, followed by GTPase-dependant constriction. Here, we describe the clinical characteristics and cellular phenotype of a patient with severe neurological dysfunction, possessing a homozygous DNM1L variant c.305C>T (p.T115M) in the GTPase domain. For comparative analysis, we also describe a previously identified heterozygous variant demonstrating a rapidly fatal neurocognitive phenotype (c.261dup/c.385:386del, p.W88M*9/E129K*6). Using patient-generated fibroblasts, we demonstrated both DNM1L variants undergo adverse alterations to mitochondrial structure and function, including impaired mitochondrial fission, reduced membrane potential, and lower oxidative capacity including an increased cellular level of reactive oxygen species (ROS) and dsDNA breaks. Mutation of DNM1L was also associated with impaired responses to oxidative stress, as treatment with hydrogen peroxide dramatically increased cellular ROS, with minimal exacerbation of already impaired mitochondrial function. Taken together, our observations indicate that homozygous p.T115M variant of DNM1L produces a neurological and neurodevelopmental phenotype, consistent with impaired mitochondrial architecture and function, through a diminished ability to oligomerize, which was most prevalent under oxidative stress.
Cheng, P.-W.; Liu, S.-H.; Young, Y.-H.; Lin-Shiau, Shoei-Yn
Cisplatin has been used as a chemotherapeutic agent to treat many kinds of malignancies. Its damage to the vestibulo-ocular reflex (VOR) system has been reported. However, the underlying biochemical change in the inner ear or central vestibular nervous system is not fully understood. In this study, we attempted to examine whether cisplatin-induced vestibulotoxicity and D-methionine protection were correlated with the changes of ATPase activities and oxidative stress of ampullary tissue of vestibules as well as cerebellar cortex (the inhibitory center of VOR system) of guinea pigs. By means of a caloric test coupled with electronystagmographic recordings, we found that cisplatin exposure caused a dose-dependent (1, 3, or 5 mg/kg) vestibular dysfunction as revealed by a decrease of slow phase velocity (SPV). In addition, cisplatin significantly inhibited the Na + , K + -ATPase and Ca 2+ -ATPase activities in the ampullary tissue with a good dose-response relationship but not those of cerebellar cortex. Regression analysis indicated that a decrease of SPV was well correlated with the reduction of Na + , K + -ATPase and Ca 2+ -ATPase activities of the ampullary tissue. D-Methionine (300 mg/kg) reduced both abnormalities of SPV and ATPase activities in a correlated manner. Moreover, cisplatin exposure led to a significant dose-dependent increase of lipid peroxidation and nitric oxide concentrations of the vestibules, which could be significantly suppressed by D-methionine. However, cisplatin did not alter the levels of lipid peroxidation and nitric oxide of the cerebellum. In conclusion, cisplatin inhibited ATPase activities and increased oxidative stress in guinea pig vestibular labyrinths. D-Methionine attenuated cisplatin-induced vestibulotoxicity associated with ionic disturbance through its antioxidative property
Bentli, Recep; Ciftci, Osman; Cetin, Asli; Otlu, Ali
This study aimed to investigate the potential beneficial effects of the montelukast (ML) on oxidative stress and histological alterations in liver tissues and cytokine levels in rats intoxicated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Rats were divided randomly into four equal groups (control, TCDD, ML, TCDD + ML). TCDD were administered by gavages dissolved in corn oil at the doses of 2 µg/kg/week, and ML was given intraperitoneally at the dose of 10 mg/kg/day. Oxidative status, histological alterations, and cytokine levels were analyzed on day 60. The results showed that although TCDD induced oxidative stress via significant increase in formation of thiobarbituric acid reactive substance, it caused a significant decline in glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD) levels in liver. Besides, TCDD led to significant histopathological damage in liver and serum cytokine levels alterations (increase in tumor necrosis factor α and interleukin 1β levels). In contrast, ML treatment reversed oxidative effects of TCDD by increasing the levels of GSH, CAT, and SOD and decreasing the formation of TBARS. Also, it can normalize the levels of histological and cytokine alterations induced by TCDD. In conclusion, it was determined that TCDD exposure caused adverse effects on cytokine levels, histological alterations, and oxidative stress in rats. However, ML treatment partially eliminated toxic effects of TCDD. Thus, it was judged that coadministration of ML with TCDD may be useful to attenuate the negative effects of TCDD. © The Author(s) 2013.
McGovern, F M; Campion, F P; Lott, S; Boland, T M
The present study was conducted to examine the effects of offering a single diet rationed to 80% (80% ME), 100% (100% ME), or 120% (120% ME) of recommended ME requirements from d 119 of gestation to lambing, with concurrent changes in other dietary nutrients. The effects on pre- and postpartum ewe performance, including estimated milk yield and milk fatty acid concentrations, were monitored. Sixty twin-bearing ewes were allocated to 1 of 3 dietary treatments ( = 20 per treatment) and individually fed for the final 4 wk of gestation. Metabolizable energy requirements were individually calculated for each ewe and amended according to treatment. Ewes were rationed daily on the basis of their treatment ME allocation, which led to concurrent alterations in other nutrient intakes. Diets were grass silage based and supplemented with concentrates to meet treatment ME allocation on an individual ewe basis. Ewes offered the 80% ME treatment had a lower liveweight ( = 0.04) and BCS ( = 0.03) at 24 h postpartum when compared with ewes offered the 120% ME diet. Although there was no difference in liveweight at either d 40 ( = 0.18) or 98 postpartum ( = 0.20), the difference in BCS persisted until d 40 postpartum ( = 0.02). Colostrum yield at 1 h postpartum ( = 0.03) and total yield up to 18 h postpartum ( = 0.04) was greater for ewes offered the 120% ME diet than either of the other treatment groups. Similarly, these ewes had a greater estimated milk yield during wk 3 of lactation ( = 0.04) and elevated concentrations of short-chain SFA ( = 0.02) and long-chain SFA ( ≤ 0.05) from wk 2 through 6 of lactation. In summary, the negative impact of applying a dietary insult to ewes in late gestation is reflected in colostrum and estimated milk yield and fatty acid composition, thus potentially influencing postpartum growth and development of the offspring.
Turner, Michael J; Guderian, Sophie; Wikstrom, Erik A; Huot, Joshua R; Peck, Bailey D; Arthur, Susan T; Marino, Joseph S; Hubbard-Turner, Tricia
We assessed the impact of differing physical activity levels throughout the lifespan, using a musculoskeletal injury model, on the age-related changes in left ventricular (LV) parameters in active mice. Forty male mice (CBA/J) were randomly placed into one of three running wheel groups (transected CFL group, transected ATFL/CFL group, SHAM group) or a SHAM Sedentary group (SHAMSED). Before surgery and every 6 weeks after surgery, LV parameters were measured under 2.5 % isoflurane inhalation. Group effects for daily distance run was significantly greater for the SHAM and lesser for the ATLF/CFL mice (p = 0.013) with distance run decreasing with age for all mice (p age, interaction (group × age) was noted with LV posterior wall thickness-to-radius ratios (h/r) where h/r increased with age in the ATFL/CFL and SHAMSED mice while the SHAM and CFL mice exhibited decreased h/r with age (p = 0.0002). Passive filling velocity (E wave) was significantly greater in the SHAM mice and lowest for the ATFL/CFL and SHAMSED mice (p age. Active filling velocity (A wave) was not different between groups (p = 0.10). Passive-to-active filling velocity ratio (E/A ratio) was different between groups (p activity beginning at 9 months of age. Passive-to-active filling velocity ratio decreased with age (p activity throughout the lifespan improved LV structure, passive filling velocity, and E/A ratio by 6 to 9 months of age and attenuated any negative alterations throughout the second half of life. The diastolic filling differences were found to be significantly related to the amount of activity performed by 9 months and at the end of the lifespan.
Delwing-de Lima, Daniela; Fröhlich, Monique; Dalmedico, Leticia; Aurélio, Juliana Gruenwaldt Maia; Delwing-Dal Magro, Débora; Pereira, Eduardo Manoel; Wyse, Angela T S
We evaluated the in vitro effects of galactose at 0.1, 3.0, 5.0 and 10.0 mM on thiobarbituric acid-reactive substances (TBA-RS), total sulfhydryl content, protein carbonyl content, on the activities of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and on acetylcholinesterase (AChE) activity in the cerebral cortex, cerebellum and hippocampus of rats. We also investigated the influence of the antioxidants (each at 1 mM), α-tocopherol, ascorbic acid and glutathione, on the effects elicited by galactose on the parameters tested. Results showed that galactose, at a concentration of 3.0 mM, enhanced TBA-RS levels in the hippocampus, cerebral cortex and cerebellum of rats. In the cerebral cortex, galactose at concentrations of 5.0 and 10.0 mM increased TBA-RS and protein carbonyl content, and at 10.0 mM increased CAT activity and decreased AChE activity. In the cerebellum, galactose at concentrations of 5.0 and 10.0 mM increased TBA-RS, SOD and GSH-Px activities. In the hippocampus, galactose at concentrations of 5.0 and 10.0 mM increased TBA-RS and CAT activity and at 10.0 mM decreased GSH-Px. Data showed that at the pathologically high concentration (greater than 5.0 mM), galactose induces lipid peroxidation, protein carbonylation, alters antioxidant defenses in the cerebrum, and also alters cholinesterase activity. Trolox, ascorbic acid and glutathione addition prevented the majority of alterations in oxidative stress parameters and the decrease in AChE activity that were caused by galactose. Our findings lend support to a potential therapeutic strategy for this condition, which may include the use of appropriate antioxidants for ameliorating the damage caused by galactose.
Full Text Available Abstract Background Molecular hydrogen (H2 functions as an extensive protector against oxidative stress, inflammation and allergic reaction in various biological models and clinical tests; however, its essential mechanisms remain unknown. H2 directly reacts with the strong reactive nitrogen species peroxynitrite (ONOO- as well as hydroxyl radicals (•OH, but not with nitric oxide radical (NO•. We hypothesized that one of the H2 functions is caused by reducing cellular ONOO-, which is generated by the rapid reaction of NO• with superoxides (•O2-. To verify this hypothesis, we examined whether H2 could restore cytotoxicity and transcriptional alterations induced by ONOO- derived from NO• in chondrocytes. Methods We treated cultured chondrocytes from porcine hindlimb cartilage or from rat meniscus fibrecartilage with a donor of NO•, S-nitroso-N-acetylpenicillamine (SNAP in the presence or absence of H2. Chondrocyte viability was determined using a LIVE/DEAD Viability/Cytotoxicity Kit. Gene expressions of the matrix proteins of cartilage and the matrix metalloproteinases were analyzed by reverse transcriptase-coupled real-time PCR method. Results SNAP treatment increased the levels of nitrated proteins. H2 decreased the levels of the nitrated proteins, and suppressed chondrocyte death. It is known that the matrix proteins of cartilage (including aggrecan and type II collagen and matrix metalloproteinases (such as MMP3 and MMP13 are down- and up-regulated by ONOO-, respectively. H2 restoratively increased the gene expressions of aggrecan and type II collagen in the presence of H2. Conversely, the gene expressions of MMP3 and MMP13 were restoratively down-regulated with H2. Thus, H2 acted to restore transcriptional alterations induced by ONOO-. Conclusions These results imply that one of the functions of H2 exhibits cytoprotective effects and transcriptional alterations through reducing ONOO-. Moreover, novel pharmacological strategies
Calabria, Jaqueline Alves de Almeida
The radioactive wastes from nuclear technology applications must be properly disposed in a repository, during the necessary time to ensure the human and the environment protection. The surface systems are largely considered for disposal of low and intermediate level radioactive waste, but generally require the use of engineering barriers to control the radionuclides release. An important engineering barrier is the backfill which is situated between the package and structural material, and has the functions of reducing the water infiltration and to promote the retardation of the radionuclide migration, among others. Therefore, the material to be used as backfill such as clays, cement, soils, rocks, must has good sorption, permeability and mechanical properties. The selection of the material will depend also largely on the material availability and installation design. The concrete is also used in the construction of repository, and its interaction with water induces its degradation, resulting in a high pH solution. This solution interacts with the backfilling materials promoting mineralogical alterations that results in significant changes in their key properties and performance as safety component of the repository. In this work, five Brazilian soils of Minas Gerais state, selected according to their generic characteristics along with information from Sistema Brasileiro de Classificacao de Solos (SiBCS) were investigated concerning their potential use as backfilling material in a superficial repository by the determination of retention capacity for cesium and iodine. Sorption-related parameters, used in the performance assessment of the soils, were obtained from experimental data fitting to different sorption isotherms models. The soil that showed the best sorption of Cs, was a clay soil that presented distribution coefficient (K d ) of 90.5 mL.g -1 and maximum sorption capacity (Q max ) of 18.372 mg.g -1 . Regarding the iodine, the sorption was very low for all
Steel fiber reinforced concrete (SFRC) is increasingly being used day by day as a structural material for various applications. The complete stress-strain curve of this material in compression is needed for the analysis and design of structural elements. An experimental investigation was carried out to generate the complete ...
Lee, Wincy Wing Sze
The present study examined the relationships among grit, academic performance, perceived academic failure, and stress levels of Hong Kong associate degree students using path analysis. Three hundred and forty-five students from a community college in Hong Kong voluntarily participated in the study. They completed a questionnaire that measured their grit (operationalized as interest and perseverance) and stress levels. The students also provided their actual academic performance and evaluated their perception of their academic performance as a success or a failure. The results of the path analysis showed that interest and perseverance were negatively associated with stress, and only perceived academic failure was positively associated with stress. These findings suggest that psychological appraisal and resources are more important antecedents of stress than objective negative events. Therefore, fostering students' psychological resilience may alleviate the stress experienced by associate degree students or college students in general. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.
Full Text Available This paper examines the impact of information on psychology of music on Stress and Anxiety Levels of Brazilian students of music performance, both undergraduate and graduate, and cross information on their levels of stress and anxiety. It includes an investigation on curricular programs of Brazilian public universities based on previous investigation by the authors (RAY; et al, 2011. The main goals: 1 to investigate how much information Brazilian music performance students has access to access during their courses; and 2 to identify potential indicators of the impact this information may have on the levels of stress and anxiety in the performances of these students; Methodology: Students from six Brazilian public universities were requested to fill out three forms: the Kenny Music Performance Anxiety Inventory (K-MPAI; the Inventory of Stress Symptoms LIPP and an additional form that investigated the participants routine for preparation to performance. Results: information on music performance psychology is only presented privately at teacher’s discretion. As compulsory classes have not been included in the curriculum, it was not possible to infer results on this subject. More than half of the participants (51,72% don’t present stress condition. Almost half of them (48,27% have some level of stress. All participants fit within some level of anxiety.
Lees, Ty; Lal, Sara
Nurses function inside a particularly stressful occupation that requires the provision of continuous care to individuals who are often in great need. Stress has been shown to impair performance and specifically shown to impair nursing quality. However, we do not yet know how stress influences the cognitive performance of nurses, and hence, the present study investigated the associations between stress and cognitive performance in nurses using electroencephalography and administered cognitive assessments. Thirty-six nurses (34 women) of mean age 37.77 ± 11.40 years were recruited. Stress was examined using the Lifestyle Appraisal Questionnaire. Broad spectrum electroencephalogram activity at positions Fp1, Fp2, C3 and C4 was recorded for a 5-min baseline and active phase to physiologically assess cognitive performance. Additionally, the Mini-Mental State Exam and Cognistat were also used to measure cognitive performance. Assessed cognitive performance was not associated to stress, however, lifestyle factors, as well as a number of the examined cognitive electroencephalographic variables including changes in theta, alpha activity and gamma reactivity were. Definitively determining how stress affects the cognitive performance of nurses requires additional research; the present study forms a foundation from which future research can further expand the examination of stress exposure in nurses. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
Machida, Mayumi; Wellman, Laurie L; Fitzpatrick Bs, Mairen E; Hallum Bs, Olga; Sutton Bs, Amy M; Lonart, György; Sanford, Larry D
Stressful events can directly produce significant alterations in subsequent sleep, in particular rapid eye movement sleep (REM); however, the neural mechanisms underlying the process are not fully known. Here, we investigated the role of the basolateral nuclei of the amygdala (BLA) in regulating the effects of stressful experience on sleep. We used optogenetics to briefly inhibit glutamatergic cells in BLA during the presentation of inescapable footshock (IS) and assessed effects on sleep, the acute stress response, and fear memory. c-Fos expression was also assessed in the amygdala and the medial prefrontal cortex (mPFC), both regions involved in coping with stress, and in brain stem regions implicated in the regulation of REM. Compared to control mice, peri-shock inhibition of BLA attenuated an immediate reduction in REM after IS and produced a significant overall increase in REM. Moreover, upon exposure to the shock context alone, mice receiving peri-shock inhibition of BLA during training showed increased REM without altered freezing (an index of fear memory) or stress-induced hyperthermia (an index of acute stress response). Inhibition of BLA during REM under freely sleeping conditions enhanced REM only when body temperature was high, suggesting the effect was influenced by stress. Peri-shock inhibition of BLA also led to elevated c-Fos expression in the central nucleus of the amygdala and mPFC and differentially altered c-Fos activity in the selected brain stem regions. Glutamatergic cells in BLA can modulate the effects of stress on REM and can mediate effects of fear memory on sleep that can be independent of behavioral fear. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail email@example.com.
Serpil M. Deger
Full Text Available In contrast to the adverse outcomes of obesity in general population, increased body mass index (BMI is associated with improved survival in hemodialysis (CHD patients. The aim of this retrospective study was to evaluate the association between obesity and mortality by diabetic status among 98 maintenance CHD patients. The median follow up was 33 (19, 56 months. Mean age was 49±13 years, 66% were male and 48 % had obesity. 45% of obese subjects were diabetic. Among the subgroups of study population, survival of diabetic obese patients was significantly lower compared to non-diabetic obese subjects (p=0.007 (Figure 1. The subgroup comparisons showed that diabetic obese patients tend to have higher truncal fat percentage (p<0.001 and lower lean body mass standardized by body surface area compared to nondiabetic counterparts although difference was not statistically significance. Diabetic obese patients had higher leptin (p=0.001 and high sensitivity C-reactive protein levels (0.005. Additionally, protein thiols (P-SH were significantly decreased in diabetic obese participants (p=0.03. Although, elevated body fatness appears to be protective for CHD population, presence of overt diabetes alters this advantage by increasing inflammation and oxidative stress.fx1
Stress is a common element in any kind of job and people face it in almost every walk of life. In the banking sector particularly, higher management do not realize the impact of stress on employee performance which ultimately results in critical managerial dilemmas. Work overload & time pressure to complete too much work in short span of time is big source of stress which decrease the performance of employees. The purpose of this research are to analyze the influence of work stress on employe...
Ko, Sung Min; Song, Meong Gun; Chee, Hyun Kun; Hwang, Hweung Kon; Feuchtner, Gudrun Maria; Min, James K.
OBJECTIVE The purpose of this study was to assess the diagnostic performance of stress perfusion dual-energy CT (DECT) and its incremental value when used with coronary CT angiography (CTA) for identifying hemodynamically significant coronary artery disease. SUBJECTS AND METHODS One hundred patients with suspected or known coronary artery disease without chronic myocardial infarction detected with coronary CTA underwent stress perfusion DECT, stress cardiovascular perfusion MRI, and invasive coronary angiography (ICA). Stress perfusion DECT and cardiovascular stress perfusion MR images were used for detecting perfusion defects. Coronary CTA and ICA were evaluated in the detection of ≥ 50% coronary stenosis. The diagnostic performance of coronary CTA for detecting hemodynamically significant stenosis was assessed before and after stress perfusion DECT on a pervessel basis with ICA and cardiovascular stress perfusion MRI as the reference standard. RESULTS The performance of stress perfusion DECT compared with cardiovascular stress perfusion MRI on a per-vessel basis in the detection of perfusion defects was sensitivity, 89%; specificity, 74%; positive predictive value, 73%; negative predictive value, 90%. Per segment, these values were sensitivity, 76%; specificity, 80%; positive predictive value, 63%; and negative predictive value, 88%. Compared with ICA and cardiovascular stress perfusion MRI per vessel territory the sensitivity, specificity, positive predictive value, and negative predictive value of coronary CTA were 95%, 61%, 61%, and 95%. The values for stress perfusion DECT were 92%, 72%, 68%, and 94%. The values for coronary CTA and stress perfusion DECT were 88%, 79%, 73%, and 91%. The ROC AUC increased from 0.78 to 0.84 (p = 0.02) with the use of coronary CTA and stress perfusion DECT compared with coronary CTA alone. CONCLUSION Stress perfusion DECT plays a complementary role in enhancing the accuracy of coronary CTA for identifying hemodynamically
Otter, R T A; Brink, M S; van der Does, H T D; Lemmink, K A P M
The purpose was to investigate perceived stress and recovery related to cycling performance of female athletes over one full year. 20 female athletes (age, 27±8 years; ˙VO2max, 50.3±4.6 mL·kg(-1)·min(-1)) were measured 8 times in one year to determine perceived stress and recovery (RESTQ-Sport) in relation to cycling performance (Lamberts and Lambert Submaximal Cycle Test (LSCT)). All 19 RESTQ-Sport scales were calculated and scores of the 4 main categories were determined (i. e., general stress, general recovery, sport-specific stress and sport-specific recovery). A balance score of total stress and recovery was calculated by recovery-stress. Power at the second stage (P80), third stage (P90) and heart rate recovery (HRR60 s) of the LSCT were determined as performance parameters. 110 RESTQ-Sports and LSCTs were analysed using a multilevel approach (random intercepts model). Higher self-efficacy was related to improvement of all performance parameters. Higher total recovery stress, and lower emotional stress were related to improvement of P90 and HRR60 s. Higher sport-specific recovery was related to P80, higher general stress, fatigue and physical complaints were related to decreased P90 and higher social stress and injury were related to decreased HRR60 s. Improved perceived recovery and stress contributed to an improved performance. Relevant information could be provided by monitoring changes in perceived stress and recovery of female athletes. © Georg Thieme Verlag KG Stuttgart · New York.
Raja Abdul Ghafoor Khan; Furqan Ahmad Khan; Dr. Muhammad Aslam Khan; Mohsin Shakeel
Stress, work-family conflicts and flexible scheduling are three of the most important elements in organizational studies. The focus of current study is to understand the effect of Stress,work family conflicts and flexible scheduling on employee’s performance and also to understand whether flexible scheduling helps in reducing stress and work-family conflicts or not. The back bone of this study is the secondary data comprised of comprehensive literature review. A survey has also been conducted...
LYA FELDMAN; LILA GONCALVES; GRACE CHACÓN-PUIGNAU; JOANMIR ZARAGOZA; NURI BAGÉS; JOAN DE PABLO
The objective of the present study was to evaluate academic stress, social support and their relationships with mental health and academic performance in university students. Three hundred and twenty one students from a technological university in Caracas, Venezuela, responded instruments on academic stress, social support and mental health during the most academically stressful period. The results indicate that favorable conditions of mental health were associated to more social support and ...
Baker, B G; Bhalla, A; Doleman, B; Yarnold, E; Simons, S; Lund, J N; Williams, J P
Simulation-based training (SBT) has become an increasingly important method by which doctors learn. Stress has an impact upon learning, performance, technical, and non-technical skills. However, there are currently no studies that compare stress in the clinical and simulated environment. We aimed to compare objective (heart rate variability, HRV) and subjective (state trait anxiety inventory, STAI) measures of stress theatre with a simulated environment. HRV recordings were obtained from eight anesthetic trainees performing an uncomplicated rapid sequence induction at pre-determined procedural steps using a wireless Polar RS800CX monitor © in an emergency theatre setting. This was repeated in the simulated environment. Participants completed an STAI before and after the procedure. Eight trainees completed the study. The theatre environment caused an increase in objective stress vs baseline (p = .004). There was no significant difference between average objective stress levels across all time points (p = .20) between environments. However, there was a significant interaction between the variables of objective stress and environment (p = .045). There was no significant difference in subjective stress (p = .27) between environments. Simulation was unable to accurately replicate the stress of the technical procedure. This is the first study that compares the stress during SBT with the theatre environment and has implications for the assessment of simulated environments for use in examinations, rating of technical and non-technical skills, and stress management training.
Das, Saroj Kumar; Baitharu, Iswar; Barhwal, Kalpana; Hota, Sunil Kumar; Singh, Shashi Bala
Social isolation stress and its effect on mood have been well reported, but the effect of monotony (a state of repetition of events for a considerable period of time without variation) on mood and hippocampal synaptic plasticity needs to be addressed. Present study was conducted on male Sprague-Dawley rats. Singly housed (SH) rats were subjected to monotony stress by physical, visual and pheromonal separation in specially designed animal segregation chamber. Fluoxetine (a selective serotonin reuptake inhibitor) was administered orally. Behavioral assessment showed anxiety and depression like traits in SH group. Monotony stress exposure to SH group resulted in increased pyknosis, decreased apical dendritic arborization and increased asymmetric (excitatory) synapses with the corresponding decrease in the symmetric (inhibitory) synapses in the hippocampal CA3 region. Monotonous environment during isolation stress also decreased the serotonin level and reduced the expression of synaptophysin and pCREB in the hippocampus. Fluoxetine administration to singly housed rats resulted in amelioration of altered mood along with improvement in serotonin and decrease in excitatory synaptic density but no change in altered inhibitory synaptic density in the hippocampus. These findings suggest that monotony during isolation contributes to early impairment in mood state by altering hippocampal synaptic density and neuronal morphology. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
María Eugenia Hernandez
Full Text Available Major depressive disorder patients present chronic stress and decreased immunity. The Wistar-Kyoto rat (WKY is a strain in which the hypothalamic-pituitary-adrenal axis is overactivated. To determine whether chronic stress induces changes in corticosterone levels and splenic lymphoid tissue, 9-week-old male rats were subject to restraint stress (3 h daily, chemical stress (hydrocortisone treatment, 50 mg/Kg weight, mixed stress (restraint plus hydrocortisone, or control treatment (without stress for 1, 4, and 7 weeks. The serum corticosterone levels by RIA and spleens morphology were analyzed. Corticosterone levels as did the structure, size of the follicles and morphology of the parenchyma (increase in red pulp in the spleen, varied depending on time and type of stressor. These changes indicate that chronic stress alters the immune response in the spleen in WKY rats by inducing morphological changes, explaining in part the impaired immunity that develops in organisms that are exposed to chronic stress.
Afsar, Tayyaba; Razak, Suhail; Almajwal, Ali; Khan, Muhammad Rashid
Cisplatin (CP) drug is platinum compounds used for the treatment of various human malignancies. However, adverse outcomes related to CP restrict its usage. Acacia hydaspica is a natural shrub with various pharmacological properties. The current investigation aimed to assess the protective potential of A. hydaspica polyphenol rich ethyl acetate extract (AHE) against cisplatin (CP) induced pulmonary toxicity. Rats were divided into six groups. Group 1 served as control (saline); Group 2 (drug control) recieved single dose of CP (7.5 mg/kg i.p.) on 1st day; Group 3 (extract control) (400 mg/kg bw, p.o.) received AHE for one week; Group 4 (Post-treated) and Group 5 (pretreated) received AHE (400 mg/kg bw/day, p.o) for 7 days after and before CP (7.5 mg/kg b.w., i.p.) respectively; Group 6 (Standard control) received silymarin (100 mg/kg b.w/7 days) before CP. At the end of dosing rats were sacrificed and pulmonary tissue samples were processed for the evaluation of antioxidant enzymes, oxidative stress markers, genotoxicity and histopathological alterations. CP caused body weights loss and increase pulmonary tissue weight. The CP significantly increases oxidative stress markers and decreases tissue antioxidant enzyme levels. Furthermore, CP induced deleterious changes in the microanatomy of pulmonary tissue by rupturing the alveolar septa, thickening of alveolar walls, and injuring the cells with subsequent collapse of blood vessels. AHE pretreatment returned MDA, NO, H 2 O 2 production and improved tissue antioxidant enzyme levels to near normalcy. The histological observations evidenced that AHE effectively rescues the lungs from CP-mediated oxidative damage. CP induction in rats also caused DNA fragmentation which was restored by AHE treatment. Our results suggest that pretreatment more significantly improve CP induced deleterious effects compared with post treatment indicating protective effect. Potency of AHE pretreatment is similar to silymarin. These
Mense, Sarah M.; Remotti, Fabrizio; Bhan, Ashima; Singh, Bhupendra; El-Tamer, Mahmoud; Hei, Tom K.; Bhat, Hari K.
Epidemiological evidence indicates that prolonged lifetime exposure to estrogen is associated with elevated breast cancer risk in women. Oxidative stress and estrogen receptor-associated proliferative changes are suggested to play important roles in estrogen-induced breast carcinogenesis. In the present study, we investigated changes in breast morphology and oxidative stress following estrogen exposure. Female ACI rats were treated with 17β-estradiol (E 2 , 3 mg, s.c.) for either 7, 15, 120 or 240 days. Animals were euthanized, tissues were excised, and portions of the tissues were either fixed in 10% buffered formalin or snap-frozen in liquid nitrogen. Paraffin-embedded tissues were examined for histopathologic changes. Proliferative changes appeared in the breast after 7 days of E 2 exposure. Atypical ductal proliferation and significant reduction in stromal fat were observed following 120 days of E 2 exposure. Both in situ and invasive carcinomas were observed in the majority of the mammary glands from rats treated with E 2 for 240 days. Palpable breast tumors were observed in 82% of E 2 -treated rats after 228 days, with the first palpable tumor appearing after 128 days. No morphological changes were observed in the livers, kidneys, lungs or brains of rats treated with E 2 for 240 days compared to controls. Furthermore, 8-isoprostane (8-isoPGF 2α ) levels as well as the activities of antioxidant enzymes, such as glutathione peroxidase, superoxide dismutase and catalase, were quantified in the breast tissues of rats treated with E 2 for 7, 15, 120 and 240 days and compared to activity levels in age-matched controls. 8-isoPGF 2α levels displayed time-dependent increases upon E 2 treatment and were significantly higher than control levels at the 15, 120 and 240 day time-points. 8-isoPGF 2α observed in E 2 -induced mammary tumors were significantly higher than levels found in control mammary tissue from age-matched animals. Similarly, alterations in glutathione
Full Text Available This study was conducted to examine the effect of emotional intelligence in the relationship between occupational stress and job performance using 104 usable questionnaires gathered from academic employees who work in private institutions of higher learning in Kuching City, Malaysia. The outcomes of testing research hypothesis using a stepwise regression analysis showed that relationship between occupational stress and emotional intelligence significantly correlated with job performance. Statistically, the result confirms that the inclusion of emotional intelligence in the analysis has mediated the effect of occupational stress on job performance in the organizational sector sample. Further, implications and discussion are elaborated.
Stojanovska-Georgievska, L.; Atanassova, E.; Novkovski, N.
Tantalum pentoxide thin films with their high dielectric constant are very promising material for various application, especially in microelectronics. Their behavior when high electrical field is applied is of special interest. In the present work we study MOS structures containing tantalum pentoxide films obtained by thermal oxidation of Ta films deposited on Si. The influence of top electrode ( Al, Au and W) on wear out and the degradation of the films are experimentally studied, by estimating the value of created oxide charges and the value of degradation of the intermediate SiO 2 layer thickness, when constant voltage is applied. The calculations for oxide charges are made by using the extracted value for capacitance in accumulation regime, from high frequency C-V measurements, by known extrapolation method. The measurements were performed for consequent constant voltage stress in time intervals of 20 s. The degradation of the intermediate SiO 2 layer is estimated in terms of calculating the changes of EOT after each voltage stress. (Author)
Stewart, S M; Lam, T H; Betson, C L; Wong, C M; Wong, A M
This study provides prospective, longitudinal data on the relationship between stress-related measures and academic performance during the first two years of medical school. First year medical students (n = 121) were surveyed prior to beginning classes (wave 1), and again 8 months later (wave 2). Personality variables predisposing to distress (optimism and trait anxiety), stress response (depression and state anxiety), and stress management strategies were assessed at wave 1 and wave 2. Pre-medical academic scores, and grades at the end of five assessment periods over the course of the first 2 years of medical school were also obtained. As expected, pre-medical-school academic performance strongly predicted performance in medical school. Academic performance before and during medical school was negatively related to reported stress levels. On bivariate correlations, there were numerous significant relationships between stress reported at waves 1 and 2, and medical school academic performance assessed after these measures. In addition there were modest negative correlations between self-reported coping strategies of 'humour' and 'wishful thinking', and consequent academic performance. However, the predictive value of stress and its management on prospective academic performance was much decreased once pre-medical-school performance was statistically controlled.
Dieleman, Gwendolyn C; Huizink, Anja C; Tulen, Joke H M; Utens, Elisabeth M W J; Creemers, Hanneke E; van der Ende, Jan; Verhulst, Frank C
It is of debate whether or not childhood anxiety disorders (AD) can be captured by one taxonomic construct. This study examined whether perceived arousal (PA), autonomic nervous system (ANS) and hypothalamic-pituitary-adrenal (HPA) axis measures can distinguish children with different primary diagnoses of clinical anxiety disorders (AD) from each other, and from a general population reference group (GP). The study sample consisted of 152 AD children (comparing separation anxiety disorder, generalized anxiety disorder, social phobia and specific phobia), aged 8- to 12-years, and 200 same-aged reference children. HPA-axis functioning was measured by a diurnal cortisol profile. ANS functioning was measured by continuous measures of skin conductance level in rest and during a mental arithmetic task and high frequency heart rate variability in rest. PA was assessed by a questionnaire. The AD sample showed lower high frequency heart rate variability during rest, heightened anticipatory PA, higher basal and reactive skin conductance levels and lower basal HPA-axis functioning compared to the GP sample. The existence of three or more clinical disorders, i.e. a high clinical 'load', was associated with lower basal HPA-axis functioning, higher skin conductance level and lower posttest PA. Specific phobia could be discerned from social phobia and separation anxiety disorder on higher skin conductance level. Our findings indicated that children with AD have specific psychophysiological characteristics, which resemble the psychophysiological characteristics of chronic stress. A high clinical 'load' is associated with an altered ANS and HPA-axis functioning. Overall, ANS and HPA-axis functioning relate to AD in general, accept for specific phobia. Copyright © 2014 Elsevier Ltd. All rights reserved.
Whitfield, Matthew; Cachia, Moira
This study looks at the effect of perceived stress upon employees within the workplace environment and how it impacts their operating performance. Qualitative methodology was applied to gather in-depth information about the participants’ experience of employment and associated factors that induce stress. This article reports the research outcome, relating the results to previous research on the topic.
L. E. Hislop; M. A. Ritter
The Connell Lake bridge was constructed in early 1991 on the Tongass National Forest, Alaska, as a demonstration bridge under the Timber Bridge Initiative. The bridge is a stress-laminated deck structure with an approximate 36-ft length and 18-ft width and is the first known stress-laminated timber bridge constructed in Alaska. Performance of the bridge was monitored...
Star, L.; Kemp, B.; Anker, van den I.; Parmentier, H.K.
Effects of long-term climatic stress (heat exposure), short-term hygienic stress [lipopolysaccharide (LPS)], or a combination of both challenges on performance of 4 layer lines were investigated. The lines were earlier characterized by natural humoral immune competence and survival rate. At 22 wk of
M. A. Ritter; P. D. Hilbrich Lee; G. J. Porter
The Hoffman Run bridge, located just outside Dahoga, Pennsylvania, was constructed in October 1990. The bridge is a simple-span, single-lane, stress-laminated deck superstructure that is approximately 26 ft long and 16 ft wide. It is the second stress-laminated timber bridge to be constructed of hardwood lumber in Pennsylvania. The performance of the bridge was...
Albeg, Loren J.; Castro-Olivo, Sara M.
This study evaluated the relationship between acculturative stress, symptoms of internalizing mental health problems, and academic performance in a sample of 94 Latino middle school students. Students reported on symptoms indicative of depression and anxiety related problems and acculturative stress. Teachers reported on students' academic…
Pettit, Michele L.; DeBarr, Kathy A.
Objective: This study explored relationships regarding perceived stress, energy drink consumption, and academic performance among college students. Participants: Participants included 136 undergraduates attending a large southern plains university. Methods: Participants completed surveys including items from the Perceived Stress Scale and items to…
Otter, R. T. A.; Brink, M. S.; van der Does, H. T. D.; Lemmink, K. A. P. M.
The purpose was to investigate perceived stress and recovery related to cycling performance of female athletes over one full year. 20 female athletes ( age, 27 +/- 8 years; VO2max, 50.3 +/- 4.6 mL center dot kg(-1) center dot min(-1)) were measured 8 times in one year to determine perceived stress
Disturbances in fatty acid (FA) metabolism may link chronic psychological stress, endocrine responsiveness, and psychopathology. Therefore, lipid metabolome-wide responses and their relationships with endocrine (cortisol; insulin; adiponectin) responsiveness to acute stress (AS) were assessed in a ...
Full Text Available This research aims at finding out the relationship between Organizational Climate, job stress and job performance among State Education Department (JPN officers . The focus of the research is to determeane the job performance of state education department officers, level of job stress among the officers, level of connection between organizational climate with job stress of State Education Department officers, looking at the difference in level of performance according to demographic factors and looking at the influence of organizational climate and job stress towards job performance . Research findings pertaining level of job performance showed that 75.8% of the respondents are at a high level, 23.7% respondents are at a moderate level while 0.5% respondents are at a low level. For organizational climate, findings show that 79.0% respondents are in the moderate level, 1.6 % respondents are at a highlevel and 19.4% respondents are at a low level. Findings on overall level of job stress found that as many as 92.5% respondents are at a normal job stress. Only about 7.5% respondents are at a moderate level of job stress. There is not even one respondent who are facing a high level of job stress. In terms of the relationship between independent variables (organizational climate, job stress and dependent variable (job performance, the research findings show that there is a moderate level of positive relationship which is quite significant between organizational climate and job performance of the State Education Department officers at α = 0.01 (p < 0.01; r = 0.396.
Morita, V S; Almeida, V R; Matos Junior, J B; Vicentini, T I; van den Brand, H; Boleli, I C
The current study aimed to investigate whether embryonic temperature manipulation may alter thermal preference throughout the rearing phase of broiler chickens and how this manipulation may affect response to thermal challenge, metabolism, growth rate and feed intake rate. Eggs were exposed to a constant incubation temperature [machine temperatures: 36°C (Low), 37.5°C (Control), and 39°C (High); eggshell temperature of 37.4 ± 0.08°C, 37.8 ± 0.15°C, and 38.8 ± 0.33°C, respectively] from d 13 till hatching. Low treatment chickens showed lower plasma T3 and GH levels at d 1 of age and lower T3 level at d 42 of age compared to the Control treatment. Preferred ambient, rectal temperature, T4 level, growth rate, food intake rate, and response to thermal challenge were not altered in these chickens. On the other hand, High-treatment chickens exhibited high preferred ambient temperature and rectal temperature during the first 2 wk post-hatch, lower plasma T3 level at d 21 and 42 and a delayed increase in respiratory movement in response to thermal challenge compared to the Control treatment. However, chickens subjected to the Control and High treatments did not differ in T4 and GH level and performance. We conclude that exposure to high temperature during late embryonic development has long-lasting effects on the thermoregulatory system of broiler chickens by affecting the heat tolerance of these chickens. Moreover, the preferred ambient temperature of the chickens from heat-treated eggs correspond to those recommended for the strain under study, whereas for the cold-treated and control-chickens it was 1°C below, indicating that incubation temperature might have consequences on the ambient temperature chickens require during the rearing phase. © 2016 Poultry Science Association Inc.
Full Text Available Researchers and scholars of management and behavioral sciences have tried to determine effective factors, which influence on efficiency and effectiveness in order to increase organization performance and they have tried to identify factors, which create job stress. In this research, we investigate the effect of job stress on job performance through emotional, organizational and moral intelligence. The study is a descriptive-analytic one, which is based on correlation, uses survey method to gather data and they are analyzed using structural equation modeling. The population of this research includes all the personnel of Registry Organization in Arak city. The results suggest that job stress influences on job performance through organizational intelligence and moral intelligence, but job stress does not influence on job performance through emotional intelligence. Regarding research hypotheses, results and findings after analyzing obtained data suggest that job stress influences on emotional, organizational and moral intelligence, but job stress does not influence on job performance. In addition, the results show that organizational and moral intelligence influence on job performance but emotional intelligence does not influence on job performance.
Hazzard MP, Quinn TJ, Castellani JW. Hypohydration effects on thermoregulation during moderate exercise in the cold . Eur J Appl Physiol 92: 565–570, 2004...compared with cold exposure (13, 41, 55). The strong modifying effect of Tsk on aerobic performance when dehydrated supports the proposed underly- ing...13. Cheuvront SN, Carter R 3rd, Castellani JW, Sawka MN. Hypohy- dration impairs endurance exercise performance in temperate but not cold air. J Appl
Azman Ismail; Yeo Suh-Suh; Mohd Na’eim Ajis; Noor Faizzah Dollah
This study was conducted to examine the effect of emotional intelligence in the relationship between occupational stress and job performance using 104 usable questionnaires gathered from academic employees who work in private institutions of higher learning in Kuching City, Malaysia. The outcomes of testing research hypothesis using a stepwise regression analysis showed that relationship between occupational stress and emotional intelligence significantly correlated with job performance. Stat...
Mojtaba Rafiee; Hojat Kazemi; Mustafa Alimiri
Researchers and scholars of management and behavioral sciences have tried to determine effective factors, which influence on efficiency and effectiveness in order to increase organization performance and they have tried to identify factors, which create job stress. In this research, we investigate the effect of job stress on job performance through emotional, organizational and moral intelligence. The study is a descriptive-analytic one, which is based on correlation, uses survey method to ga...
Melaku, Leta; Mossie, Andualem; Negash, Alemayehu
Background. Chronic stress among medical students affects academic performance of students and leads to depression, substance use, and suicide. There is, however, a shortage of such research evidence in Ethiopia. Objective. We aimed to estimate the prevalence and severity of stress and its association with substance use and academic performance among medical students. Methods. A cross-sectional survey was conducted on a sample of 329 medical students at Jimma University. Data were collected u...
Park, Hyung Woo; Kee, Baik Seok; Na, Churl; Na, Do-Hyun E.; Zaichkowsky, Leonard
Objective The purpose of this study was to compare cognitive flexibility abilities, stress, and anxiety between starters and non-starter athletes. Methods A total of 30 male professional-soccer and 40 professional-baseball athletes were recruited. Wisconsin Card Sorting Test (WCST) and Trail Making Test A & B (TMT A & B) were administered to assess cognitive flexibility during competition. The Korean version of the STAI form Y (STAI-KY) and Visual analogue scale for anxiety and stress were used to assess the anxiety and stress. Results The starter group had better cognitive function (fewer perseverative errors and rapid TMTB times) (Z=3.32, panxiety (F=4.34, p=0.01; F=6.61, pcognitive performances were negatively correlated with stress and anxiety. Current results suggested that cognitive flexibility would enhance human performance by modulation of the anxiety and stress during competition. PMID:21994509
López, E; Mellado, M; Martínez, A M; Véliz, F G; García, J E; de Santiago, A; Carrillo, E
This study aimed to investigate the effect of heat stress and month of birth on growth performance, pelleted starter intake, and stress-related hormones in Holstein calves. Birth weight and growth records, representing 4735 Holstein calves from a large commercial dairy herd in northern Mexico (25° N; 22.3 °C mean annual temperature) from 2013 to 2015, were analyzed. Temperature-humidity index (THI) at calving, season of birth, and month of birth were the independent variables, whereas growth traits were the dependent variables. Increased THI at birth from 85 units was associated with a decrease in birth weight from 39.3 to 38.7 kg. Calves subjected to high THI (> 75 units) at calving showed lesser (P calves born with THI calves born in the fall was about 70 g less (P calves delivered in winter months. Plasma triiodothyronine and tetraiodothyronine levels were lower (1.02 ± 0.21 and 48 ± 7.9 ng/mL, respectively; P calves born in summer (59 ± 40 ng/mL) than calves born in winter (20 ± 28 ng/mL). Pelleted starter intake 1 week before weaning was lowest (P calves. Thus, environmental management of the newborn calf during hot spring and summer months is warranted to optimize pelleted starter intake and calf growth rates.
Brown, Rhonda; Dunn, Stewart; Byrnes, Karen; Morris, Richard; Heinrich, Paul; Shaw, Joanne
No studies have previously evaluated factors associated with high stress levels and poor communication performance in breaking bad news (BBN) consultations. This study determined factors that were most strongly related to doctors' stress responses and poor communication performance during a simulated BBN task. In 2007, the authors recruited 24 doctors comprising 12 novices (i.e., interns/residents with 1-3 years' experience) and 12 experts (i.e., registrars, medical/radiation oncologists, or cancer surgeons, with more than 4 years' experience). Doctors participated in simulated BBN consultations and a number of control tasks. Five-minute-epoch heart rate (HR), HR variability, and communication performance were assessed in all participants. Subjects also completed a short questionnaire asking about their prior experience BBN, perceived stress, psychological distress (i.e., anxiety, depression), fatigue, and burnout. High stress responses were related to inexperience with BBN, fatigue, and giving bad versus good news. Poor communication performance in the consultation was related to high burnout and fatigue scores. These results suggest that BBN was a stressful experience for doctors even in a simulated encounter, especially for those who were inexperienced and/or fatigued. Poor communication performance was related to burnout and fatigue, but not inexperience with BBN. These results likely indicate that burnout and fatigue contributed to stress and poor work performance in some doctors during the simulated BBN task.
Cohen, Miri; Khalaila, Rabia
Salivary pH is regulated by the sympathetic and parasympathetic nervous system; therefore, it may serve as a biomarker of stress. To assess the associations between the cognitive and emotional dimensions of exam stress and pH levels, and the predictability of salivary pH in relation to test performance. A prospective study. Eighty-three nursing students answered a questionnaire on stress appraisals, experienced stress, test anxiety (including worry and emotionality subscales) and health behaviors, and gave a saliva sample for measuring pH on the morning of their first term exam and three months later. Their performance on the test (grades) was also recorded. Levels of pH in saliva were higher (levels of acidity were lower) in the post exam compared to the exam period, in parallel to lower threat appraisal, experienced stress, and test anxiety levels post exam. Controlling for smoking, physical activity and working hours per week, pH levels at both time points were predicted by appraised threat regarding the exam situation, experienced stress, and the emotionality dimension of test anxiety. pH at Time 1 predicted performance on the exams and mediated the associations of experienced stress and emotionality subscale with test performance. the present study indicates that pH levels may serve as a reliable, accessible and inexpensive means by which to assess the degree of physiological reactions to exams and other naturalistic stressors. Copyright © 2014 Elsevier Inc. All rights reserved.
Our previous research, conducted under well-watered conditions without fertilizer application, showed that fuzziness cottonseed trait resulted in cottonseed nutrition differences between fuzzy (F) and fuzzless (N) cottonseed. Under water stress conditions, B mobility is further limited, inhibiting B movement within the plant, affecting seed nutrition (quality). Therefore, we hypothesized that both foliar B and water stress can affect B mobility, altering cottonseed protein, oil, and mineral nutrition. The objective of the current research was to evaluate the effects of the fuzziness seed trait on boron (B) and seed nutrition under water stress and foliar B application using near-isogenic cotton lines (NILs) grown in a repeated greenhouse experiment. Plants were grown under-well watered conditions (The soil water potential was kept between -15 to -20 kPa, considered field capacity) and water stress conditions (soil water potential between -100 and -150 kPa, stressed conditions). Foliar B was applied at a rate of 1.8 kg B ha-1 as H3BO3. Under well-watered conditions without B the concentrations of seed oil in N lines were higher than in F lines, and seed K and N levels were lower in N lines than in F lines. Concentrations of K, N, and B in leaves were higher in N lines than in F lines, opposing the trend in seeds. Water-stress resulted in higher seed protein concentrations, and the contribution of cell wall (structural) B to the total B exceeded 90%, supporting the structural role of B in plants. Foliar B application under well-watered conditions resulted in higher seed protein, oil, C, N, and B in only some lines. This research showed that cottonseed nutrition differences can occur due to seed fuzziness trait, and water stress and foliar B application can alter cottonseed nutrition. PMID:26098564
141 (26%) Race/Ethnicity Black/ African -American = 194 (36%) White/ Caucasian = 189 (35%) Asian = 71 (14%) Hispanic = 33 (6%) Other = 53 (9...after testing. These biosamples were analyzed for cortisol and testosterone changes that might relate to task performance or CBFv. Additional
Chen, Yinglong; Wang, Haimiao; Hu, Wei; Wang, Shanshan; Wang, Youhua; Snider, John L; Zhou, Zhiguo
Soil waterlogging events and high temperature conditions occur frequently in the Yangtze River Valley, yet the effects of these co-occurring stresses on fiber elongation have received little attention. In the current study, the combined effect of elevated temperature (ET) and soil waterlogging (SW) more negatively affected final fiber length (reduced by 5.4%-11.3%) than either stress alone by altering the composition of osmotically active solutes (sucrose, malate, and K + ), where SW had the most pronounced effect. High temperature accelerated early fiber development, but limited the duration of elongation, thereby limiting final fiber length. Treatment of ET alone altered fiber sucrose content mainly through decreased source strength and the expression of the sucrose transporter gene GhSUT-1, making sucrose availability the primary determinant of final fiber length under ET. Waterlogging stress alone decreased source strength, down-regulated GhSUT-1 expression and enhanced SuSy catalytic activity for sucrose reduction. Waterlogging treatment alone also limited fiber malate production by down-regulating GhPEPC-1 & -2. However, combined elevated temperature and waterlogging limited primary cell wall synthesis by affecting GhCESAs genes and showed a negative impact on all three major osmotic solutes through the regulation of GhSUT-1, GhPEPC-1 & -2 and GhKT-1 expression and altered SuSy activity, which functioned together to produce a shorter fiber length. Copyright © 2017 Elsevier B.V. All rights reserved.
Wheelan, Nicola; Kenyon, Christopher J; Harris, Anjanette P; Cairns, Carolynn; Al Dujaili, Emad; Seckl, Jonathan R; Yau, Joyce L W
Chronic exposure to stress during midlife associates with subsequent age-related cognitive decline and may increase the vulnerability to develop psychiatric conditions. Increased hypothalamic-pituitary-adrenal (HPA) axis activity has been implicated in pathogenesis though any causative role for glucocorticoids is unestablished. This study investigated the contribution of local glucocorticoid regeneration by the intracellular enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), in persisting midlife stress-induced behavioral effects in mice. Middle-aged (10 months old) 11β-HSD1-deficient mice and wild-type congenic controls were randomly assigned to 28 days of chronic unpredictable stress or left undisturbed (non-stressed). All mice underwent behavioral testing at the end of the stress/non-stress period and again 6-7 months later. Chronic stress impaired spatial memory in middle-aged wild-type mice. The effects, involving a wide spectrum of behavioral modalities, persisted for 6-7 months after cessation of stress into early senescence. Enduring effects after midlife stress included impaired spatial memory, enhanced contextual fear memory, impaired fear extinction, heightened anxiety, depressive-like behavior, as well as reduced hippocampal glucocorticoid receptor mRNA expression. In contrast, 11β-HSD1 deficient mice resisted both immediate and enduring effects of chronic stress, despite similar stress-induced increases in systemic glucocorticoid activity during midlife stress. In conclusion, chronic stress in midlife exerts persisting effects leading to cognitive and affective dysfunction in old age via mechanisms that depend, at least in part, on brain glucocorticoids generated locally by 11β-HSD1. This finding supports selective 11β-HSD1 inhibition as a novel therapeutic target to ameliorate the long-term consequences of stress-related psychiatric disorders in midlife. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.
..., are listed in appendix A. (b) The holder of a mechanic certificate may perform maintenance, preventive... is no certificated mechanic available to perform preventive maintenance; (4) The certificate holder... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Persons authorized to perform maintenance...
Ivancevic, Tijana; Greenberg, Ronald
This book is designed to help athletes and individuals interested in high sports performance in their journey towards the perfection of human sports abilities and achievements. It has two main goals: accelerating the acquisition of motor skills and preparing and vigilantly reducing the recovery time after training and competition. The Diamond Sports Protocol (DSP) presents state-of-the-art techniques for current sport and health technologies, particularly neuromuscular electrical stimulation (Sports Wave), oxygen infusion (Oxy Sports), infrared (Sports Infrared Dome) and lactic acid cleaning (Turbo Sports). The book suggest DSP as an essential part of every future athlete's training, competition and health maintenance. The book is for everyone interested in superior sports performance, fast and effective rehabilitation from training and competition and sports injury prevention.
Hughes, Brian M
This study sought to establish the impact of performance-related feedback on cardiovascular responses to stressors, and whether this impact is influenced by individual differences in self-esteem. A total of 66 college women were categorized as either high or low in self-esteem on the basis of their scores in a standardized psychometric test. They then took part in a laboratory experiment, in which they were assigned to one of three performance-feedback manipulations. Following the provision of feedback on an initial laboratory task (picture-matching), they undertook a second task (mental arithmetic). Cardiovascular functioning was monitored throughout. Provision of negative feedback to the initial task exerted an adverse impact on cardiovascular responses, suggestive of unhappiness with performance. Provision of positive feedback to the initial task exerted an impact on cardiovascular functioning during the second task, suggestive of task engagement. Importantly, low self-esteem exacerbated the adverse impact of negative feedback. The impact of feedback and the buffering role of self-esteem may have important consequences for cardiovascular health. Further, discrepancies in the findings of previous feedback research may be accounted for by dispositional individual differences.
Moore, Dale A; Truscott, Marla L; St Clair, Lisa; Klingborg, Donald J
Assuming leadership roles in veterinary student governance or club activities could be considered an added stressor for students because of the impact on time available for personal and academic activities. The study reported here evaluated the effects of participation in a leadership program and leadership activity across two classes of veterinary students on measures of stress, using the Derogatis Stress Profile (DSP), and on veterinary school academic performance, measured as annual grade-point average (GPA) over a three-year period. Program participants and their classmates completed the DSP three times across the first three years of veterinary school. On average, participating students reported self-declared stress levels that were higher and measured DSP stress levels that were lower than those of the general population. Students were more likely to assume elected or appointed leadership roles while in their first three years of the veterinary degree program if they participated in the optional leadership program and demonstrated lower stress in several dimensions. Some increased stress, as measured in some of the DSP stress dimensions, had a small but statistically significant influence on professional school GPA. The study determined that the most important predictors of students' cumulative GPA across the three-year period were the GPA from the last 45 credits of pre-veterinary coursework and their quantitative GRE scores. The results of the study indicate that neither participation in the leadership program nor taking on leadership roles within veterinary school appeared to influence veterinary school academic performance or to increase stress.
Full Text Available This study analyses the role played by daily stress, assessed through self-report and at the psychobiological level, in relation to basic cognitive function when predicting school performance. The sample comprised 100 schoolchildren (55 girls and 45 boys, age range 8 to 11 years from a state school in the city of Malaga (Spain. Daily stress was assessed through the Children's Daily Stress Inventory (IIEC m Spanish; Tnanes et al., 2009. Psychobiological stress was measured through the cortisol/DHEAS ratio, derived from saliva samples taken in the morning on two consecutive days. Basic cognitive skills were assessed by means of the Computerized Cognitive Assessment System (CDR battery; Wesnes et al., 2003, 2000. Finally, the measure of school performance was the mean value of the final grades recorded in the child's school report. In addition to descriptive and correlational statistical analyses, multiple regression analyses were conducted in order to assess the model. The results show that children's daily stress self-reported contributes to predict school performance, and has proven to be more influential than basic cognitive function when it comes to predict school performance. Therefore, in order to achieve good school performance, a pupil not only requires good basic cognitive function, but must also present low levels of self-reported daily stress. These findings suggest a new way of explaining and predicting school failure.
Bárzana, Gloria; Aroca, Ricardo; Bienert, Gerd Patrick; Chaumont, François; Ruiz-Lozano, Juan Manuel
The relationship between modulation by arbuscular mycorrhizae (AM) of aquaporin expression in the host plant and changes in root hydraulic conductance, plant water status, and performance under stressful conditions is not well known. This investigation aimed to elucidate how the AM symbiosis modulates the expression of the whole set of aquaporin genes in maize plants under different growing and drought stress conditions, as well as to characterize some of these aquaporins in order to shed further light on the molecules that may be involved in the mycorrhizal responses to drought. The AM symbiosis regulated a wide number of aquaporins in the host plant, comprising members of the different aquaporin subfamilies. The regulation of these genes depends on the watering conditions and the severity of the drought stress imposed. Some of these aquaporins can transport water and also other molecules which are of physiological importance for plant performance. AM plants grew and developed better than non-AM plants under the different conditions assayed. Thus, for the first time, this study relates the well-known better performance of AM plants under drought stress to not only the water movement in their tissues but also the mobilization of N compounds, glycerol, signaling molecules, or metalloids with a role in abiotic stress tolerance. Future studies should elucidate the specific function of each aquaporin isoform regulated by the AM symbiosis in order to shed further light on how the symbiosis alters the plant fitness under stressful conditions.
Full Text Available Background. Chronic stress among medical students affects academic performance of students and leads to depression, substance use, and suicide. There is, however, a shortage of such research evidence in Ethiopia. Objective. We aimed to estimate the prevalence and severity of stress and its association with substance use and academic performance among medical students. Methods. A cross-sectional survey was conducted on a sample of 329 medical students at Jimma University. Data were collected using the General Health Questionnaire (GHQ-12, Medical Students Stress Questionnaire (MSSQ-20, and Drug Abuse Surveillance Test (DAST. Data were analyzed using SPSS version 20.0. Logistic regression analysis and Student’s t-test were applied. Results. The mean age of the respondents was 23.02 (SD = 2.074 years. The current prevalence of stress was 52.4%. Academic related stressor domain was the main source of stress among 281 (88.6% students. Stress was significantly associated with khat chewing [AOR = 3.03, 95% CI (1.17, 7.85], smoking [AOR = 4.55, 95% CI (1.05, 19.77], and alcohol intake [AOR = 1.93, 95% CI (1.03, 3.60]. The prevalence of stress was high during the initial three years of study. Stress was significantly (p=0.001 but negatively (r=-0.273 correlated with academic achievement. Conclusion. Stress was a significant problem among medical students and had a negative impact on their academic performance. Year of study, income, and substance use were associated with stress. Counseling and awareness creation are recommended.
Shah, S J; Rehman, A; Shaukat, M H S; Awais, M
An executive health examination is offered at many hospitals for "busy executives" that comprises of a typical history and examination along with screening tests for major cardiovascular and respiratory illnesses. Exercise stress tests are also frequently included in such packages, though the appropriateness of such stress testing remains uncertain. To assess the appropriateness and cost-effectiveness of exercise stress tests performed as part of executive health examinations. Records of all individuals who underwent an executive health examination at our institution between January, 2007 and December, 2012 were retrospectively reviewed. Data were collected pertaining to demographics, cardiovascular risk factors, indication of stress testing and results of exercise stress tests. Of a total of 1650 subjects who underwent exercise stress tests as part of executive health examinations, indication for exercise stress testing was class IIb or III (as per American College of Cardiology's appropriateness criteria) in 96.1 % of subjects. The cumulative cost and time burden of testing for these subjects were Rs. 11,419,200/- PKR (≈$114,192 USD) and 2 weeks and 4 days, respectively. Exercise stress tests were not positive for ischemia in any such cases. Based on the results of this study, exercise stress tests should not be routinely offered as part of executive health examinations.
Full Text Available Individuals under chronic psychological stress can be difficult to identify clinically. There is often no outwardly visible phenotype. Chronic stress of sufficient magnitude not only impacts reproductive function, but also concomitantly elicits a constellation of neuroendocrine changes that may accelerate aging in general and brain aging in particular. Functional hypothalamic amenorrhea, a phenotypically recognizable form of stress, is due to stress-induced suppression of endogenous gonadotropin-releasing hormone secretion. Reversal of functional hypothalamic amenorrhea includes restoration of ovulatory ovarian function and fertility and amelioration of hypercortisolism and hypothyroidism. Taken together, recovery from functional hypothalamic amenorrhea putatively offers neuroprotection and ameliorates stress-induced premature brain aging and possibly syndromic Alzheimer’s disease. Amenorrhea may be viewed as a sentinel indicator of stress. Hypothalamic hypogonadism is less clinically evident in men and the diagnosis is difficult to establish. Whether there are other sex differences in the impact of stress on brain aging remains to be better investigated, but it is likely that both low estradiol from stress-induced anovulation and low testosterone from stress-induced hypogonadism compromise brain health.
Full Text Available The present study was conducted to find out role of personal and job related variables in teacher stress and job performance of school teachers. Furthermore, levels and sources of stress and their relationship with job performance among teachers were also explored. The measures used in this study were indigenously developed i.e., Teacher Stress Inventory (TSI-Urdu, Teachers Job Performance Scale and personal and job related Information sheet. Two independent samples were selected from Government and Private Schools of Islamabad (Pakistan. Sample I was comprised of 400 teachers (men and women from Primary and secondary schools. For the evaluation of teachers’ job performance another sample of 1200 students from the classes of teachers of sample I was selected. Three students were randomly selected from each teacher’s class. The students were requested to evaluate their respective teachers’ job performance. The findings revealed that negative significant relationship exists between teachers stress and job performance. The step-wise regression analysis revealed school system, gender, job experience, number of family members, and number of students as significant predictors of teacher stress and gender, school system, family members, job experience and age as significant predictors of teachers’ job performance.
Alkjaer, Tine; Pilegaard, Marianne; Bakke, Merete
' perception of the stress and difficulty related to the tasks. RESULTS: Performance decreased significantly in both groups during the color word test in comparison with performance on the reference task. However, the performance reduction was more pronounced in the elderly group than in the young group......OBJECTIVES: This study examined the effects of age on performance, muscle activation, and perceived stress during computer tasks with different levels of mental demand. METHODS: Fifteen young and thirteen elderly women performed two computer tasks [color word test and reference task] with different....... Likewise, a higher level of self-reported stress was found for the elderly participants after the color word test. During the reference task higher electromyographic levels and reported difficulty were recorded for the elderly group than for the young group. CONCLUSIONS: The findings suggest that mental...
Alkjaer, Tine; Pilegaard, Marianne; Bakke, Merete
OBJECTIVES: This study examined the effects of age on performance, muscle activation, and perceived stress during computer tasks with different levels of mental demand. METHODS: Fifteen young and thirteen elderly women performed two computer tasks [color word test and reference task] with different......' perception of the stress and difficulty related to the tasks. RESULTS: Performance decreased significantly in both groups during the color word test in comparison with performance on the reference task. However, the performance reduction was more pronounced in the elderly group than in the young group....... Likewise, a higher level of self-reported stress was found for the elderly participants after the color word test. During the reference task higher electromyographic levels and reported difficulty were recorded for the elderly group than for the young group. CONCLUSIONS: The findings suggest that mental...
Stroud, Laura R; Foster, Elizabeth; Papandonatos, George D; Handwerger, Kathryn; Granger, Douglas A; Kivlighan, Katie T; Niaura, Raymond
Little is known about normative variation in stress response over the adolescent transition. This study examined neuroendocrine and cardiovascular responses to performance and peer rejection stressors over the adolescent transition in a normative sample. Participants were 82 healthy children (ages 7-12 years, n = 39, 22 females) and adolescents (ages 13-17, n = 43, 20 females) recruited through community postings. Following a habituation session, participants completed a performance (public speaking, mental arithmetic, mirror tracing) or peer rejection (exclusion challenges) stress session. Salivary cortisol, salivary alpha amylase (sAA), systolic and diastolic blood pressure (SBP, DBP), and heart rate were measured throughout. Adolescents showed significantly greater cortisol, sAA, SBP, and DBP stress response relative to children. Developmental differences were most pronounced in the performance stress session for cortisol and DBP and in the peer rejection session for sAA and SBP. Heightened physiological stress responses in typical adolescents may facilitate adaptation to new challenges of adolescence and adulthood. In high-risk adolescents, this normative shift may tip the balance toward stress response dysregulation associated with depression and other psychopathology. Specificity of physiological response by stressor type highlights the importance of a multisystem approach to the psychobiology of stress and may also have implications for understanding trajectories to psychopathology.
Flynn, M G; Carroll, K K; Hall, H L; Bushman, B A; Brolinson, P G; Weideman, C A
Twenty well-trained runners (VO2max 4.6+/-0.5 L x min[-1]) were age and ability matched and assigned to either a cross training (CT) or run only group (RT). All subjects maintained normal running distance and intensity for 6 wk and reported for three additional training sessions per week. These workouts were performed outdoors on a 400-m track or measured road course (RT) or on a bicycle ergometer (CT). The sessions were as follows: (work x rest(-1) ratio = 1): 5 x 5 min at >95% VO2max/peak (Monday), 50-60 min at 70% VO2max/peak (Wednesday), and 3 x 2.5 min at >105% VO2max/peak, plus 6 x 1.25 min at >115% VO2max/peak (Friday). Subjects were tested before (PRE), after 3 wk (MID), and after 6 wk (POST) of intensified training. Blood samples were obtained from RT, CT, and ten controls (CON) at each time point (0600 h). Runners also completed a 10-min submaximal run at the same absolute intensity (velocity to elicit 75% of initial V02max) during which heart rate, RPE, and VO2 were measured. Each runner then completed a simulated 5-km race (time trial) on a treadmill. Total testosterone (TT), free testosterone (FT), cortisol (C), and creatine kinase activity (CK) were determined. Running economy was similar between RT and CT; however, RPE decreased significantly at MID and POST compared with that at PRE (P < 0.05; time effect). There were no significant differences among groups for TT, FT, or CK, but C was significantly lower in CON than in RT and CT. Performance was significantly faster (P < 0.05; time effect) in the 5-km race at MID (1076.1+/-81.4 s) and POST (1068.6+/-83.9) compared with PRE (1096.6+/-79.5) but was not different between CT and RT. In conclusion, RT and CT responded similarly to 6 wk of increased training, and both groups improved 5-km performance to a similar extent.
Harvey, Brian H; Oosthuizen, Frasia; Brand, Linda
. The NOS isoform involved, and the role of stress-mediated corticosterone release in NOS activation, was verified with the administration of selective iNOS and nNOS inhibitors, aminoguanidine (50 mg/kg/day i.p.) and 7-nitroindazole (12.5 mg/kg/day i.p.), and the steroid synthesis inhibitor, ketoconazole...... (24 mg/kg/day i.p.), administered for 21 days prior to and during the stress procedure. RESULTS: Stress evoked a sustained increase in NOS activity, but reduced NMDA receptor density and total GABA levels. Aminoguanidine or ketoconazole, but not 7-nitroindazole or saline, blocked stress-induced NOS...
Sharp, K H; Vaughn, G M; Cosby, P W; Sewell, C E; Kennaway, D J
Residency training may disrupt normal sleep/wake cycles, resulting in mood and performance deficits and alterations in biological rhythms. To characterize such disturbances and determine whether they are associated with an alteration in the day/night pattern of melatonin excretion, measurements were obtained around-the-clock in seven male subjects, each studied in two 48-h sessions. Session 1 was conducted during the week before beginning a residency, and session 2 at 6 months into a first-year surgical residency. The mean time of the end of nocturnal sleep and the timing of the temperature rhythm were both (P less than .01) approximately 2.3 h earlier in session 2 (vs. 1). The sleepiness rhythm and the overall mood score rhythm were also phase-advanced (P less than .05) in session 2. The mean value of mood around-the-clock was significantly worse due to increased anger, tension, confusion, depression, and fatigue in session 2. Vigilance, tested by simple reaction time, did not exhibit a 25-h rhythm and was worse in session 2 with an increase (P less than .05) in mean response latency less than 1 s and an increase (P less than .01) in lapse time (microsleep, greater than 1- s latency). The urinary cortisol rhythm exhibited a raised curve average value (mesor) in session 2 (vs. 1, P less than .05), but no difference was revealed in amplitude or acrophase. Urinary excretion of Na+, K+, and Cl- did not differ between sessions, though the Na+/K+ ratio peaked earlier in session 2 (P less than .05). The urinary 6-sulfatoxymelatonin rhythm did not differ in timing, amplitude, or mesor between sessions. A residency training schedule can be associated with altered timing in rhythms of sleep, sleepiness, temperature, and mood and with deterioration of mood and performance without detectable alteration of the endogenous melatonin pattern as exhibited by the excretion rate of the principal urinary metabolite.
Full Text Available Background Some studies have shown working memory impairment following stressful situations. Also, researchers have found that working memory performance depends on many different factors such as emotional load of stimuli and gender. Objectives The present study aimed to determine the effects of stress induction on visual working memory (VWM performance among female and male university students. Methods This quasi-experimental research employed a posttest with only control group design (within-group study. A total of 62 university students (32 males and 30 females were randomly selected and allocated to experimental and control groups (mean age of 23.73. Using cold presser test (CPT, stress was induced and then, an n-back task was implemented to evaluate visual working memory function (such as the number of true items, time reactions, and the number of wrong items through emotional and non-emotional pictures. 100 pictures were selected from the international affective picture system (IASP with different valences. Results Results showed that stress impaired different visual working memory functions (P < 0.002 for true scores, P < 0.001 for reaction time, and P < 0.002 for wrong items. Conclusions In general, stress significantly decreases the VWM performances. On the one hand, females were strongly impressed by stress more than males and on the other hand, the VWM performance was better for emotional stimuli than non-emotional stimuli.
Kulac, S.; Clcek, E.; Tasdemir, U.
Scots pine (Pinus sylvestris) has a large natural distribution throughout the world, including semi-arid areas of Turkey, where it is being used for afforestation. Determining the drought resistance of Scots pine provenances can increase the success of afforestation efforts in semi-arid regions. In the first stage of this study, water-stress treatments were applied to ten provenances of one-year-old Scots pine seedlings in their second vegetation period (between April and November). The diameter and height of the seedlings were evaluated in the nursery in order to determine their morphology. The four drought-stress treatments consisted of once-weekly irrigation (IR1), twice-weekly irrigation (IR2-Control), biweekly irrigation (IR3) and open field conditions (IR4). Later, the water-stressed seedlings were planted in a semi-arid district in Bayburt, Turkey, and their survival and growth performances were evaluated over a five-year period. The nursery study showed that drought stress and provenance as well as the interaction of the two significantly affected the morphological characteristics of the seedlings. Under water-stress conditions, the best growth performance was found in the Dokurcun, Degirmendere and Dirgine provenance seedlings. Water-stress and provenance factors and their interaction also affected the open field performance of the seedlings, where the Degirmendere, Dirgine and Dokurcun provenances again exhibited the best performance. Consequently, these Scots pine provenances can be recommended for afforestation sites having conditions similar to those of the study site. (author)
Cabral, João Carlos Centurion; Veleda, Gessyka Wanglon; Mazzoleni, Martina; Colares, Elton Pinto; Neiva-Silva, Lucas; Neves, Vera Torres das
Exposure to high levels of cortisol and self-reported stress, as well as cognitive reserve, have been linked to Alzheimer's disease pathology. However, there are no studies on the interaction of these variables. The present study aims to assess the associations of measures of cortisol, self-reported stress, and cognitive reserve with neuropsychological performance in healthy elderly people; besides, to test the interactions between these variables. Cross-sectional analyzes were conducted using data on stress, cognitive reserve and clinical conditions in 145 healthy elderly adults. A neuropsychological battery was used to assess executive functions, verbal memory and processing speed. Measurement of salivary cortisol at the circadian nadir was taken. A negative association between different stress measures and performance on tasks of memory, executive functions and processing speed was observed. Elderly people with higher cognitive reserve showed superior performance on all neuropsychological measures. No significant interaction between stress and cognitive reserve to neuropsychological performance was observed. These results indicate that older adults with high levels of stress and reduced cognitive reserve may be more susceptible to cognitive impairment.
João Carlos Centurion Cabral
Full Text Available Abstract Exposure to high levels of cortisol and self-reported stress, as well as cognitive reserve, have been linked to Alzheimer’s disease pathology. However, there are no studies on the interaction of these variables. The present study aims to assess the associations of measures of cortisol, self-reported stress, and cognitive reserve with neuropsychological performance in healthy elderly people; besides, to test the interactions between these variables. Cross-sectional analyzes were conducted using data on stress, cognitive reserve and clinical conditions in 145 healthy elderly adults. A neuropsychological battery was used to assess executive functions, verbal memory and processing speed. Measurement of salivary cortisol at the circadian nadir was taken. A negative association between different stress measures and performance on tasks of memory, executive functions and processing speed was observed. Elderly people with higher cognitive reserve showed superior performance on all neuropsychological measures. No significant interaction between stress and cognitive reserve to neuropsychological performance was observed. These results indicate that older adults with high levels of stress and reduced cognitive reserve may be more susceptible to cognitive impairment.
Zou, Dujian; Liu, Tiejun; Yang, Antai; Zhao, Yanru; Du, Chengcheng
The reliability of piezoceramic based smart aggregate (SA) used for damage detection of concrete structures has already been validated by laboratory tests. However, the in situ concrete members are generally under a big range of stress levels, and the performance of SA under various compressive stresses is still unclear. In this study, an electronic universal testing machine was employed to apply different stresses on the SAs. The received signals of SA sensor accompanying with different drive signals were recorded. The experimental results show that the amplitude of received signals increases firstly, and then tends to be stable with stress. This enhancement is mainly induced by the decrease in thickness of epoxy resin layer caused by compressive stress. It indicates that the change of load applied on monitored concrete members embedded with SAs may lead to a change in monitoring signal amplitude even in elastic range, but it does not stand for the change of health state of monitored concrete member.
Zhang, Wenjin; Xie, Zhicai; Wang, Lianhong; Li, Ming; Lang, Duoyong; Zhang, Xinhui
This study was conducted to determine effect and mechanism of exogenous silicon (Si) on salt and drought tolerance of Glycyrrhiza uralensis seedling by focusing on the pathways of antioxidant defense and osmotic adjustment. Seedling growth, lipid peroxidation, antioxidant metabolism, osmolytes concentration and Si content of G. uralensis seedlings were analyzed under control, salt and drought stress [100 mM NaCl with 0, 10 and 20% of PEG-6000 (Polyethylene glycol-6000)] with or without 1 mM Si. Si addition markedly affected the G. uralensis growth in a combined dose of NaCl and PEG dependent manner. In brief, Si addition improved germination rate, germination index, seedling vitality index and biomass under control and NaCl; Si also increased radicle length under control, NaCl and NaCl-10% PEG, decreased radicle length, seedling vitality index and germination parameters under NaCl-20% PEG. The salt and drought stress-induced-oxidative stress was modulated by Si application. Generally, Si application increased catalase (CAT) activity under control and NaCl-10% PEG, ascorbate peroxidase (APX) activity under all treatments and glutathione (GSH) content under salt combined drought stress as compared with non-Si treatments, which resisted to the increase of superoxide radicals and hydrogen peroxide caused by salt and drought stress and further decreased membrane permeability and malondialdehyde (MDA) concentration. Si application also increased proline concentration under NaCl and NaCl-20% PEG, but decreased it under NaCl-10% PEG, indicating proline play an important role in G. uralensis seedling response to osmotic stress. In conclusion, Si could ameliorate adverse effects of salt and drought stress on G. uralensis likely by reducing oxidative stress and osmotic stress, and the oxidative stress was regulated through enhancing of antioxidants (mainly CAT, APX and GSH) and osmotic stress was regulated by proline.
Christensen, Janne Winther; Ahrendt, Line Peerstrup; Lintrup, Randi
affect neurons within the hippocampus; a brain region central to learning and memory. In a series of experiments, we aimed to investigate the link between performance in two learning tests, the baseline level of stress hormones, measured as faecal cortisol metabolites (FCM), fearfulness, and social rank......The ability of horses to learn and remember new tasks is fundamentally important for their use by humans. Fearfulness may, however, interfere with learning, because stimuli in the environment can overshadow signals from the rider or handler. In addition, prolonged high levels of stress hormones can...... in the novel environment (e.g. object alertness and final stage: rS = −0.43, P = 0.04), suggesting that performance under unfamiliar, stressful conditions may be predicted by behavioural responses in a fear test. There was a negative correlation between social rank and baseline stress hormones (rS = −0.43, P...
Modin, Bitte; Karvonen, Sakari; Rahkonen, Ossi; Östberg, Viveca
This study investigates cross-cultural differences in the interrelation between school performance, school segregation, and stress-related health among 9th-grade students in the greater Stockholm and Helsinki areas. Contrary to the Swedish case, it has been proposed that school performance in Finland is largely independent of the specific school…
Bloomer, Steven A; Han, Okhee; Kregel, Kevin C; Brown, Kyle E
An increasing body of evidence suggests that dysregulation of iron metabolism contributes to age-related pathologies. We have previously observed increased hepatic iron with aging, and that environmental heat stress stimulates a further increase in iron and oxidative liver injury in old rats. The purpose of this study was to determine a mechanism for the increase in hepatic iron in old rats after heat stress. Young (6 mo) and old (24 mo) Fischer 344 rats were exposed to two heating bouts separated by 24 h. Livers were harvested after the second heat stress, and protein levels of the iron import protein, transferrin receptor-1 (TFR1), and the iron export protein, ferroportin (Fpn) were determined by immunoblot. In the nonheated condition, old rats had lower TFR1 expression, and higher Fpn expression. After heat stress, TFR1 declined in the old rats, and iron chelation studies demonstrated that this decline was dependent on a hyperthermia-induced increase in iron. TFR1 did not change in the young rats after heat stress. Since TFR1 is inversely regulated by iron, our results suggest that the increase in intracellular iron with aging and heat stress lower TFR1 expression. Fpn expression increased in both age groups after heat stress, but this response was delayed in old rats. This delay in the induction of an iron exporter suggests a mechanism for the increase in hepatic iron and oxidative injury after heat stress in aged organisms. © 2013.
Milivojevic, Verica; Fox, Helen C; Jayaram-Lindstrom, Nitya; Hermes, Gretchen; Sinha, Rajita
Chronic drug abuse leads to sex-specific changes in drug cue and stress physiologic and neuroendocrine reactivity as well as in neural responses to stress and cue-related challenges and in executive function such as inhibitory control, cognitive flexibility and self control. Importantly, these functions have been associated with high risk of relapse and treatment. Alpha-2 agonism may enhance inhibitory cognitive processes in the face of stress with sex-specific effects, however this has not been previously assessed in cocaine dependence. Forty inpatient treatment-seeking cocaine dependent individuals (13F/27M) were randomly assigned to receive either placebo or up to 3mgs of Guanfacine. Three laboratory sessions were conducted following 3-4 weeks of abstinence, where patients were exposed to three 10-min personalized guided imagery conditions (stress, drug cue, combined stress/cue), one per day, on consecutive days in a random, counterbalanced order. The Stroop task was administered at baseline and immediately following imagery exposure. Guanfacine treated women improved their performance on the Stroop task following exposure to all 3 imagery conditions compared with placebo women (p=0.02). This improvement in cognitive inhibitory performance was not observed in the men. Enhancing the ability to cognitively regulate in the face of stress, drug cues and combined stress and drug cue reactivity may be key targets for medications development in cocaine dependent women. Copyright © 2017 Elsevier B.V. All rights reserved.
Jacometo, Carolina B; Osorio, Johan S; Socha, Michael; Corrêa, Marcio N; Piccioli-Cappelli, Fiorenzo; Trevisi, Erminio; Loor, Juan J
Organic trace mineral (ORG) supplementation to dairy cows in substitution of sulfate (INO) sources has been associated with improvement in immune function during stressful states such as the peripartal period. However, the effect of supplemental ORG during pregnancy on the neonatal calf is unknown. Therefore, our aim was to investigate the effects of ORG supplementation during late pregnancy on the immune system and growth of the neonatal calf. Of specific interest was the evaluation of inflammation-related microRNA (miRNA) and target gene expression in blood neutrophils as indicators of possible nutritional programming. Forty multiparous cows were supplemented for 30d prepartum with 40 mg/kg of Zn, 20 mg/kg of Mn, 5 mg/kg of Cu, and 1mg/kg of Co from either organic (ORG) or sulfate (INO) sources (total diet contained supplemental 75 mg/kg of Zn, 65 mg/kg of Mn, 11 mg/kg of Cu, and 1 mg/kg of Co, and additional Zn, Mn, and Co provided by sulfates), and a subset of calves (n=8/treatment) was used for blood immunometabolic marker and polymorphonuclear leukocyte (PMNL) gene and miRNA expression analyses. Samples were collected at birth (before colostrum feeding), 1d (24 h after colostrum intake), and 7 and 21d of age. Data were analyzed as a factorial design with the PROC MIXED procedure of SAS. No differences were detected in BW, but maternal ORG tended to increase calf withers height. Calves from INO-fed cows had greater concentrations of blood glucose, GOT, paraoxonase, myeloperoxidase, and reactive oxygen metabolites. Antioxidant capacity also was greater in INO calves. The PMNL expression of toll-like receptor pathway genes indicated a pro-inflammatory state in INO calves, with greater expression of the inflammatory mediators MYD88, IRAK1, TRAF6, NFKB, and NFKBIA. The lower expression of miR-155 and miR-125b in ORG calves indicated the potential for maternal organic trace minerals in regulating the PMNL inflammatory response at least via alterations in mRNA and
Park, Jangho; Chung, Seockhoon; An, Hoyoung; Park, Seungjin; Lee, Chul; Kim, Seong Yoon; Lee, Jae-Dam; Kim, Ki-Soo
The purpose of the present study was 1) to identify factors that may influence academic stress in medical students and 2) to investigate the causal relationships among these variables with path analysis. One hundred sixty medical students participated in the present study. Psychological parameters were assessed with the Medical Stress Scale, Minnesota Multiphasic Personality Inventory, Hamilton Depression Scale, Beck Depression Inventory, and Academic Motivation Scale. Linear regression and path analysis were used to examine the relationships among variables. Significant correlations were noted between several factors and Medical Stress scores. Specifically, Hamilton Depression Scale scores (β=0.26, p=0.03) and amotivation (β=0.20, p=0.01) and extrinsically identified regulation (β=0.27, pAcademic Motivation Scale had independent and significant influences on Medical Stress Scale scores. A path analysis model indicated that stress, motivation, and academic performance formed a triangular feedback loop. Moreover, depression was associated with both stress and motivation, and personality was associated with motivation. The triangular feedback-loop structure in the present study indicated that actions that promote motivation benefit from interventions against stress and depression. Moreover, stress management increases motivation in students. Therefore, strategies designed to reduce academic pressures in medical students should consider these factors. Additional studies should focus on the relationship between motivation and depression.
Park, Jangho; An, Hoyoung; Park, Seungjin; Lee, Chul; Kim, Seong Yoon; Lee, Jae-Dam; Kim, Ki-Soo
Objective The purpose of the present study was 1) to identify factors that may influence academic stress in medical students and 2) to investigate the causal relationships among these variables with path analysis. Methods One hundred sixty medical students participated in the present study. Psychological parameters were assessed with the Medical Stress Scale, Minnesota Multiphasic Personality Inventory, Hamilton Depression Scale, Beck Depression Inventory, and Academic Motivation Scale. Linear regression and path analysis were used to examine the relationships among variables. Results Significant correlations were noted between several factors and Medical Stress scores. Specifically, Hamilton Depression Scale scores (β=0.26, p=0.03) and amotivation (β=0.20, p=0.01) and extrinsically identified regulation (β=0.27, pAcademic Motivation Scale had independent and significant influences on Medical Stress Scale scores. A path analysis model indicated that stress, motivation, and academic performance formed a triangular feedback loop. Moreover, depression was associated with both stress and motivation, and personality was associated with motivation. Conclusion The triangular feedback-loop structure in the present study indicated that actions that promote motivation benefit from interventions against stress and depression. Moreover, stress management increases motivation in students. Therefore, strategies designed to reduce academic pressures in medical students should consider these factors. Additional studies should focus on the relationship between motivation and depression. PMID:22707964
Mandrick, Kevin; Peysakhovich, Vsevolod; Rémy, Florence; Lepron, Evelyne; Causse, Mickaël
In our anxiogenic and stressful world, the maintenance of an optimal cognitive performance is a constant challenge. It is particularly true in complex working environments (e.g. flight deck, air traffic control tower), where individuals have sometimes to cope with a high mental workload and stressful situations. Several models (i.e. processing efficiency theory, cognitive-energetical framework) have attempted to provide a conceptual basis on how human performance is modulated by high workload and stress/anxiety. These models predict that stress can reduce human cognitive efficiency, even in the absence of a visible impact on the task performance. Performance may be protected under stress thanks to compensatory effort, but only at the expense of a cognitive cost. Yet, the psychophysiological cost of this regulation remains unclear. We designed two experiments involving pupil diameter, cardiovascular and prefrontal oxygenation measurements. Participants performed the Toulouse N-back Task that intensively engaged both working memory and mental calculation processes under the threat (or not) of unpredictable aversive sounds. The results revealed that higher task difficulty (higher n level) degraded the performance and induced an increased tonic pupil diameter, heart rate and activity in the lateral prefrontal cortex, and a decreased phasic pupil response and heart rate variability. Importantly, the condition of stress did not impact the performance, but at the expense of a psychophysiological cost as demonstrated by lower phasic pupil response, and greater heart rate and prefrontal activity. Prefrontal cortex seems to be a central region for mitigating the influence of stress because it subserves crucial functions (e.g. inhibition, working memory) that can promote the engagement of coping strategies. Overall, findings confirmed the psychophysiological cost of both mental effort and stress. Stress likely triggered increased motivation and the recruitment of additional
Full Text Available The hippocampus is sensitive to high levels of glucocorticoids during stress responses; it suffers biochemical and cellular changes that affect spatial memory and exploratory behavior, among others. We analyzed the influence of the neurosteroid progesterone (PROG on stress-induced changes in urinary corticosterone (CORT levels, spatial memory and exploratory behavior.Castrated adult male rats were implanted with PROG or vehicle (VEHI,and then exposed for ten days to chronic stress created by overcrowding or ultrasonic noise. PROG and CORT levels were assessed in urine using highperformanceliquid chromatography (HPLC. Implanted PROG inhibited the rise of stress-induced CORT, prevented spatial memory impairment in the Morris water maze, and eliminated increased exploratory behavior in the hole-board test. These results suggest a protective role of PROG, possibly mediated by its anxiolytic mechanisms, against corticosteroids elevation and the behavioral deficit generated by stressful situations.
Mohammad Navid Forsatkar
Full Text Available Background: Fluoxetine (ProzacTM is one of the most popular antidepressant that can be released to aquatic systems via sewage-treatment effluents. It is suspected to provoke substantial effects in the aquatic environment. Methods: In spawning tanks, specimens were exposed to concentrations of 0 and 0.54 µgl-1 fluoxetine from male introduction until the larvae had hatched. Prior to spawning, nest area and time spent for nest building were measured. Also, spawning duration, number of copulations per spawning and eggs per copulation, total produced eggs and hatching rate were recorded. Results: The number of copulations, eggs per copulation and total produced eggs did not differ between the two treatments. Fluoxetine treatment significantly decreased the nest size, time spent for nest building and spawning duration. Also hatching rate was significantly lower during fluoxetine treatment than in the control condition. Notably, five fluoxetine treated males cannibalized their eggs and larvae. Conclusion: We showed that environmental exposure of fighting fish to fluoxetine potentially alters specific aspects of nest building and sexual behavior and, as a consequence, reproductive output.
Verheyden, Geert; Ruesen, Carolien; Gorissen, Monique; Brumby, Victoria; Moran, Rachel; Burnett, Malcolm; Ashburn, Ann
Trunk control is impaired after stroke but little is known about how changes in posture relate to other deficits. We examined spinal postural alignment in people with chronic stroke and explored the relationship between postural alignment and clinical measures. Twenty-one subjects with stroke and 22 age-matched healthy comparison subjects participated in this observational, cross-sectional study. Data collection included measurements of thoracic, lumbar, sacral, and overall postural alignment in the sagittal plane in both sitting and standing. Measurements were made in different postures, including: upright, flexed forward, and extended backward. Clinical outcome measures included the Trunk Impairment Scale and its subscales, Fugl-Meyer Scale, Berg Balance Scale, Barthel Index, and Stroke Impact Scale. Significant deviations in postural alignment for participants with stroke compared with comparison subjects were apparent in sacral alignment (P Scale (r = -0.61) and Berg Balance Scale (r = -0.64). Participants with greater anterior pelvic tilt when flexed forward and more overall inclination when flexed forward and extended backward scored better on the Trunk Impairment Scale, its subscales, and Berg Balance Scale (r = -0.6-0.7). People with chronic stroke have altered postural alignment in standing compared with subjects without neurological deficits. Investigating interventions focusing on increasing anterior and posterior pelvic tilt seem warranted.Video Abstract available. See video (Supplemental Digital Content 1, http://links.lww.com/JNPT/A76) for more insights from the authors.
Casati, Riccardo; Vedani, Maurizio; Tuissi, Ausonio
A novel approach to achieve an extraordinary high stress recovery shape memory effect based on thermal cycling of stress-induced martensite is proposed. An alternative thermodynamic path is considered in order to achieve outstanding functional properties of Ni-rich NiTi alloys, which are commonly used at room or body temperature as superelastic materials. Fatigue tests revealed excellent stability of the material subjected to the novel thermomechanical path, confirming its suitability for employment in high-performance shape memory actuators
Dulmen, S.; Tromp, F.; Grosfeld, F.; ten Cate, Th.J.; Bensing, J.
Seventy second-year medical students volunteered to participate in a study with the aim of evaluating the impact of the assessment of simulated bad news consultations on their physiological and psychological stress and communication performance. Measurements were taken of salivary cortisol, systolic and diastolic blood pressure, heart rate, state anxiety and global stress using a Visual Analogue Scale. The subjects were asked to take three salivary cortisol samples on the assessment day as we...
Czerniak, Efrat; Biegon, Anat; Ziv, Amitai; Karnieli-Miller, Orit; Weiser, Mark; Alon, Uri; Citron, Atay
Performance is paramount in traditional healing rituals. From a Western perspective, such performative behavior can be understood principally as inducing patients' faith in the performer's supernatural healing powers and effecting positive changes through the same mechanisms attributed to the placebo response, which is defined as improvement of clinical outcome in individuals receiving inactive treatment. Here we examined the possibility of using theatrical performance tools, including stage directions and scripting, to reproducibly manipulate the style and content of a simulated doctor-patient encounter and influence the placebo response in experimental pain. A total of 122 healthy volunteers (18-45 years, 76 men) exposed to experimental pain (the cold pressor test) were assessed for pain threshold and tolerance before and after receiving a placebo cream from a "doctor" impersonated by a trained actor. The actor alternated between two distinct scripts and stage directions, i.e., performance styles created by a theater director/playwright, one emulating a standard doctor-patient encounter (scenario A) and the other emphasizing attentiveness and strong suggestion, elements also present in ritual healing (scenario B). The placebo response size was calculated as the %difference in pain threshold and tolerance after exposure relative to baseline. In addition, subjects demonstrating a ≥30% increase in pain threshold or tolerance relative to baseline were defined as responders. Each encounter was videotaped in its entirety. Inspection of the videotapes confirmed the reproducibility and consistency of the distinct scenarios enacted by the "doctor"-performer. Furthermore, scenario B resulted in a significant increase in pain threshold relative to scenario A. Interestingly, this increase derived from the placebo responder subgroup; as shown by two-way analysis of variance (performance style, F = 4.30; p = 0.040; η(2) = 0.035; style × responder status interaction term, F
Negro, Sara; Bartolomé, Ester; Molina, Antonio; Solé, Marina; Gómez, Mª Dolores; Valera, Mercedes
The stress level is suggested to have a negative effect on horses during equestrian competitions, specifically in trotter racing. The main objectives of this study were to measure stress levels in Spanish Trotter Horse races with a reliable non-invasive method, and determining the threshold level of stress that leads to the best performance results and also shows when the stress perceived by the horse becomes distress. One hundred and thirty individuals were evaluated, measuring their performance (based on racing time per kilometre (TPK)) and their stress (based on eye temperature, assessed with infrared thermography, and heart rate) in different competitions. Eye temperature and heart rate measurements were collected 2h before the race and immediately following the race, and the increases of eye temperature (∆ET) and heart rate were estimated. ∆ET and eye temperature before the race showed significant differences related to the performance level after a GLM analysis. The segmented regression analysis indicated that when the animal was more stressed before the race than just after finishing it (∆ET<0), it showed the poorest competition results, and from the breakpoint (reached at ∆ET=-0.97%), horse's performance started to improve. When comparing eye temperature variables and TPK with a response surface plot, TPK was optimum (77.27s) when the eye temperature before the race and ∆ET reached values of 37.61°C and 7.57%, respectively. Therefore, the stress levels of the horse before the race influence its competition results, and ∆ET during competitions reaching a threshold point is related to an improvement in performance results. Copyright © 2018 Elsevier Ltd. All rights reserved.
Czerniak, Efrat; Biegon, Anat; Ziv, Amitai; Karnieli-Miller, Orit; Weiser, Mark; Alon, Uri; Citron, Atay
Background: Performance is paramount in traditional healing rituals. From a Western perspective, such performative behavior can be understood principally as inducing patients’ faith in the performer’s supernatural healing powers and effecting positive changes through the same mechanisms attributed to the placebo response, which is defined as improvement of clinical outcome in individuals receiving inactive treatment. Here we examined the possibility of using theatrical performance tools, including stage directions and scripting, to reproducibly manipulate the style and content of a simulated doctor–patient encounter and influence the placebo response in experimental pain. Methods: A total of 122 healthy volunteers (18–45 years, 76 men) exposed to experimental pain (the cold pressor test) were assessed for pain threshold and tolerance before and after receiving a placebo cream from a “doctor” impersonated by a trained actor. The actor alternated between two distinct scripts and stage directions, i.e., performance styles created by a theater director/playwright, one emulating a standard doctor–patient encounter (scenario A) and the other emphasizing attentiveness and strong suggestion, elements also present in ritual healing (scenario B). The placebo response size was calculated as the %difference in pain threshold and tolerance after exposure relative to baseline. In addition, subjects demonstrating a ≥30% increase in pain threshold or tolerance relative to baseline were defined as responders. Each encounter was videotaped in its entirety. Results: Inspection of the videotapes confirmed the reproducibility and consistency of the distinct scenarios enacted by the “doctor”-performer. Furthermore, scenario B resulted in a significant increase in pain threshold relative to scenario A. Interestingly, this increase derived from the placebo responder subgroup; as shown by two-way analysis of variance (performance style, F = 4.30; p = 0.040; η2 = 0
Wilkin, Meaghan M; Waters, Pattti; McCormick, Cheryl M; Menard, Janet L
Prior work showed that exposing rats to stress from weaning through to late adolescence (PD23-51) increased anxiety- and depression-related responses in adulthood. In the current study, we tested the hypothesis that the outcome of adolescent stress depends on the specific timing of adversity in adolescence. Male and female rats were exposed to intermittent, physical stress during either early (PD22-33) or mid -(PD35-46) adolescence, and then their anxiety- and depression-related responses to acute stressors were tested in adulthood. Early adolescent stress decreased rats' open-arm exploration in the elevated plus-maze in both male and female rats. Early adolescent stress also increased the duration of time rats spent burying in the shock-probe test and the duration of time they spent immobile in the forced swim test, but these effects were only seen in males. Stress in mid-adolescence did not increase rats' anxiety-related responding in adulthood. Instead, we observed paradoxical increases in open-arm exploration and only modest increases in shock-probe burying that failed to reach significance. Mid-adolescent stress also tended to increase depression-related immobility in the swim test. Thus, the current findings underscore the importance of timing of adolescent adversity to long-term outcomes. It appears that stress in early adolescence leads to a broader range of outcomes in adulthood, at least in male rats. By contrast, stress in mid-adolescence might have more predominant effects on risk-taking behavior (indexed by increases in open-arm activity), a possibility that merits further investigation. (c) 2012 APA, all rights reserved
Mishra, Jennifer; Backlin, William
Three experiments investigated whether musical memory was context dependent. Instrumental musicians memorized music in one context and recalled in either the same or a different context. Contexts included atypical performing environments (Experiment 1: lobby/conference room) or commonly encountered environments (Experiment 2: practice room,…
Crossbreed steers (n = 180; 507 +/- 13 lb) were fed during a 56-d receiving period to determine if supplementing chromium (Cr; KemTRACEbrandChromiumPropionate 0.04%, Kemin Industries) would improve feedlot performance and health of newly received cattle. A completely randomized block design (36 pens...
A study was designed to determine the effect of feeding yeast cell wall (YCW) on performance of newly received crossbred heifers (n = 140; 225 ± 9.4 kg) Heifers were sorted by source (n = 2) and arranged in a completely randomized block design (35 pens; 7 pens/treatment; 4 heifers/pen). Heifers were...
Abhimanyu Kumar; Reena Kulkarni
Background:School children and academics are not exempted from stress. In Indian context, especially for high school children, the demands to be placed high, parental pressures, the future career option and time bound targets along with inherent biological variations of adolescence create paramount stress. Such stress can be detrimental if not well managed. Despite of loss of lives consequent upon stress and poor performance, academic stress is less researched. Psychotherapy is the current go...
Maleszewska, Monika; Vanchin, Byambasuren; Harmsen, Martin C; Krenning, Guido
High uniform fluid shear stress (FSS) is atheroprotective and preserves the endothelial phenotype and function through activation of downstream mediators such as MAPK7 (Erk5). Endothelial cells respond to FSS thanks to mechanotransduction. However, how the resulting signaling is integrated and resolved at the epigenetic level remains elusive. We hypothesized that Polycomb methyltransferase EZH2 is involved in the effects of FSS in human endothelial cells. We showed that FSS decreases the expression of the Polycomb methyltransferase EZH2. Despite simultaneous activation of MAPK7, MAPK7 pathway does not directly influence the transcription of EZH2. Interestingly though, the knockdown of EZH2 activates the protective MAPK7 signaling in endothelial cells, even in the absence of FSS. To understand the influence of the FSS-decreased expression of EZH2 on endothelial transcriptome, we performed RNA-seq and differential gene expression analysis. We identified candidate groups of genes dependent on both EZH2 and FSS. Among those, Gene Ontology overrepresentation analysis revealed highly significant enrichment of the cell cycle-related genes, suggesting changes in proliferation. Indeed, the depletion of EZH2 strongly inhibited endothelial proliferation, indicating cell cycle arrest. The concomitant decrease in CCNA expression suggests the transition of endothelial cells into a quiescent phenotype. Further bioinformatical analysis suggested TXNIP as a possible mediator between EZH2 and cell cycle-related gene network. Our data show that EZH2 is a FSS-responsive gene. Decreased EZH2 levels enhance the activation of the atheroprotective MAPK7 signaling. Decrease in EZH2 under FSS mediates the decrease in the expression of the network of cell cycle-related genes, which allows the cells to enter quiescence. EZH2 is therefore important for the protective effects of FSS in endothelium.
Nicoleta Valentina FLOREA
Full Text Available The world is a dangerous place, offering people less safe conditions to live, to develop, to work and to perform. The organizations are also under a lot of pressure and stressor factors. Yet, the employees must work, communicate, interrelate and obtain performance and organizations competitive advantage. The article analyze the main stressor factors which are influencing the individual and the organization activity, the different causes of stress appearance and its negative influence over the normal activity of employees. It also analyze the best practices which may be implemented by the organization in order to reduce the impact of stress and obtain performance This article suggests some ways of minimizing the stress appearance, by implementing efficient measures at strategic level, such as implementing efficient regulation and procedures, developing efficient programs of communication, creating a strong organizational culture and implicating the management function in solving the problems and finding pertinent solutions.
Turner, J; Bartlett, D; Andiappan, M; Cabot, L
To identify students' perceptions of barriers to effective study and the relationship between these and demographic characteristics, levels of perceived stress and examination performance. A questionnaire was distributed to first (BDS1) and final year (BDS5) King's College London dental undergraduates, during Spring 2013. Data were collected on students' social and working environment using a Likert scale from zero to four. Levels of perceived stress and end-of-year examination results were collected. Statistical analyses were undertaken using SPSS® and Stata® software. A response rate of 83.0% (BDS1) and 82.9% (BDS5) was achieved. Social distractions were perceived to hinder study, with median scores of two and three for females and males respectively. The mean perceived stress score differed significantly (p=0.001) between males and females. Difficulties with journey was a significant predictor of perceived stress (p=0.03) as were family responsibilities (p=0.02). Social distractions were significantly related to examination performance (p=0.001). Social distractions were the barrier most highly rated as hindering effective study. Levels of perceived stress were high and were significantly associated with gender, a difficult journey to university and family responsibilities. Social distractions were significantly related to examination performance; students rating social distractions highly, performed less well.
Nieto Fernández-Pacheco, Antonio; Castro Delgado, Rafael; Arcos González, Pedro; Navarro Fernández, José Luis; Cerón Madrigal, José Joaquín; Juguera Rodriguez, Laura; Perez Alonso, Nuria; Armero-Barranco, David; Lidon López Iborra, María; Damian, Escribano Tortosa; Pardo Rios, Manuel
To determine the stress that is potentially produced in professional health workers due to a mass casualty incident (MCI) simulated exercise, and its relation to prior academic training and the role played in the simulation. Observational study of stress in a MCI. For this work, two MCI drills comprised of 40 victims each were conducted. Two randomized groups of 36 students each were created: Master's Students Group (MSG) and Undergraduate Student Group (USG). The role performed by each student (triage or sectorization) was assessed. The stress level was determined by prior and subsequent measurements of alpha-amylase (αA), HR, SBP and DBP. The percentage of victims that were correctly triaged was 88.6%, 91.84% for MSG and 83.76% for the USG (p=0.004). The basal αA was 97,107.50±72,182.67IU/L and the subsequent αA was 136,195.55±90,176.46±IU/L (pperformed the triage and those who performed sectorization but there were no differences between undergraduate and Masters' students. Conducting a simulated exercise caused stress in personnel involved in the MCI, with a greater impact on participants who performed triage, although it was not influenced by their prior academic level. The stress level in our case did not affect or determine the performance of acquired skills. Copyright © 2017 Elsevier Ltd. All rights reserved.
Laurent, Heidemarie; Vergara-Lopez, Chrystal; Stroud, Laura R
Efforts to define hypothalamic-pituitary-adrenal (HPA) axis profiles conferring risk for psychopathology have yielded inconclusive results, perhaps in part due to limited assessment of the stress response. In particular, research has typically focused on HPA responses to performance tasks, while neglecting the interpersonal stressors that become salient during adolescence. In this study we investigated links between psychosocial adjustment - youth internalizing and externalizing problems, as well as competence - and HPA responses to both performance and interpersonal stressors in a normative sample of children and adolescents. Participants (n = 59) completed a set of performance (public speaking, mental arithmetic, mirror tracing) and/or interpersonal (peer rejection) tasks and gave nine saliva samples, which were assayed for cortisol. Hierarchical linear models of cortisol response trajectories in relation to child behavior checklist (CBCL) scores revealed stressor- and sex-specific associations. Whereas internalizing problems related to earlier peaking, less dynamic cortisol responses to interpersonal stress (across males and females), externalizing problems related to lower, earlier peaking and less dynamic cortisol responses to performance stress for males only, and competence-related to later peaking cortisol responses to interpersonal stress for females only. Implications for understanding contextual stress profiles underlying different forms of psychopathology are discussed.
Rossi-George, A.; Virgolini, M.B.; Weston, D.; Cory-Slechta, D.A.
Combined exposures to maternal lead (Pb) and prenatal stress (PS) can act synergistically to enhance behavioral and neurochemical toxicity in offspring. Maternal Pb itself causes permanent dysfunction of the body's major stress system, the hypothalamic pituitary adrenal (HPA) axis. The current study sought to determine the potential involvement of altered negative glucocorticoid feedback as a mechanistic basis of the effects in rats of maternal Pb (0, 50 or 150 ppm in drinking water beginning 2 mo prior to breeding), prenatal stress (PS; restraint on gestational days 16-17) and combined maternal Pb + PS in 8 mo old male and female offspring. Corticosterone changes were measured over 24 h following an i.p. injection stress containing vehicle or 100 or 300 μg/kg (females) or 100 or 150 μg/kg (males) dexamethasone (DEX). Both Pb and PS prolonged the time course of corticosterone reduction following vehicle injection stress. Pb effects were non-monotonic, with a greater impact at 50 vs. 150 ppm, particularly in males, where further enhancement occurred with PS. In accord with these findings, the efficacy of DEX in suppressing corticosterone was reduced by Pb and Pb + PS in both genders, with Pb efficacy enhanced by PS in females, over the first 6 h post-administration. A marked prolongation of DEX effects was found in males. Thus, Pb, PS and Pb + PS, sometimes additively, produced hypercortisolism in both genders, followed by hypocortisolism in males, consistent with HPA axis dysfunction. These findings may provide a plausible unifying biological mechanism for the reported links between Pb exposure and stress-associated diseases and disorders mediated via the HPA axis, including obesity, hypertension, diabetes, anxiety, schizophrenia and depression. They also suggest broadening of Pb screening programs to pregnant women in high stress environments
Lu, X K; Shu, N; Wang, J J; Chen, X G; Wang, D L; Wang, S; Fan, W L; Guo, X N; Guo, L X; Ye, W W
Cytosine DNA methylation is a significant form of DNA modification closely associated with gene expression in eukaryotes, fungi, animals, and plants. Although the reference genomes of cotton (Gossypium hirsutum L.) have been publically available, the salinity-stress-induced DNA methylome alterations in cotton are not well understood. Here, we constructed a map of genome-wide DNA methylation characteristics of cotton leaves under salt stress using the methylated DNA immunoprecipitation sequencing method. The results showed that the methylation reads on chromosome 9 were most comparable with those on the other chromosomes, but the greatest changes occurred on chromosome 8 under salt stress. The DNA methylation pattern analysis indicated that a relatively higher methylation density was found in the upstream2k and downstream2k elements of the CDS region and CG-islands. Almost 94% of the reads belonged to LTR-gspsy and LTR-copia, and the number of methylation reads in LTR-gypsy was four times greater than that in LTR-copia in both control and stressed samples. The analysis of differentially methylated regions (DMRs) showed that the gene elements upstream2k, intron, and downstream2k were hypomethylated, but the CDS regions were hypermethylated. The GO (Gene Ontology) analysis suggested that the methylated genes were most enriched in cellular processes, metabolic processes, cell parts and catalytic activities, which might be closely correlated with response to NaCl stress. In this study, we completed a genomic DNA methylation profile and conducted a DMR analysis under salt stress, which provided valuable information for the better understanding of epigenetics in response to salt stress in cotton.
Brewer, Jacob S.
It is well known that exposure to severe stress increases the risk for developing mood disorders. Currently, the neurobiological and genetic mechanisms underlying the functional effects of psychological stress are poorly understood. Presenting a major obstacle to the study of psychological stress is the inability of current animal models of stress to distinguish between physical and psychological stressors. A novel paradigm recently developed by Warren et al., is able to tease apart the effects of physical and psychological stress in adult mice by allowing these mice to "witness," the social defeat of another mouse thus removing confounding variables associated with physical stressors. Using this 'witness' model of stress and RNA-Seq technology, the current study aims to study the genetic effects of psychological stress. After, witnessing the social defeat of another mouse, VTA tissue was extracted, sequenced, and analyzed for differential expression. Since genes often work together in complex networks, a pathway and gene ontology (GO) analysis was performed using data from the differential expression analysis. The pathway and GO analyzes revealed a perturbation of the glutamatergic synapse pathway and an enrichment of positive excitatory post-synaptic potential regulation. This is consistent with the excitatory synapse theory of depression. Together these findings demonstrate a dysregulation of the mesolimbic reward pathway at the gene level as a result of psychological stress potentially contributing to depressive like behaviors.
Khoo, Jeffrey P; Davies, Joan E; Ang, Keng Leong; Galiñanes, Manuel; Chin, Derek T
In patients being considered for aortic valve replacement, there remains controversy over which design or tissue offers the best performance. We aimed to evaluate in a single study the haemodynamic performances of five different widely used aortic valve prostheses: stentless porcine xenograft (Elan), stentless bovine pericardium (Pericarbon Freedom), stented porcine xenograft (Aspire), stented bovine pericardium (More) and mechanical (Ultracor). We also compared them with normal aortic valves and stenosed valves of variable severity. Preoperative echocardiography and dobutamine stress echocardiography at 1 year postoperatively were undertaken in 106 patients (n=18-24 from each group). Stentless bioprostheses, whether porcine or bovine, displayed superior haemodynamics across nearly all echocardiographic parameters: lower gradients, larger effective orifice area, higher dimensionless severity index (DSI) and lower resistance, when compared with stented or mechanical prostheses. Comparing both stented designs, bovine tissue performed the worst at rest, but with stress, there was no difference. The stress performances of the stentless bioprostheses were similar to the mildly stenosed native aortic valve, whereas the performances of the stented and mechanical prostheses resembled that of native valves with mild-to-moderate stenoses. Haemodynamic differences, however, did not translate into differences in left ventricular mass reduction at 1 year. Stentless bioprostheses displayed haemodynamics superior to stented or mechanical prostheses and had the closest performance to a normal, native aortic valve. Stress DSI data, least reliant on variable annulus/valve sizes and flow rates, provided the best haemodynamic discrimination.
Ehrlich, David E.; Neigh, Gretchen N.; Bourke, Chase H.; Nemeth, Christina L.; Hazra, Rimi; Ryan, Steven J.; Rowson, Sydney; Jairam, Nesha; Sholar, Courtney; Rainnie, Donald G.; Stowe, Zachary N.; Owens, Michael J.
Depression during pregnancy has been linked to in utero stress and is associated with long-lasting symptoms in offspring, including anxiety, helplessness, attentional deficits, and social withdrawal. Depression is diagnosed in 10-20% of expectant mothers, but the impact of antidepressant treatment on offspring development is not well documented, particularly for females. Here, we used a prenatal stress model of maternal depression to test the hypothesis that in utero antidepressant treatment could mitigate the effects of prenatal stress. We also investigated the effects of prenatal stress and antidepressant treatment on gene expression related to GABAergic and serotonergic neurotransmission in the amygdala, which may underlie behavioral effects of prenatal stress. Nulliparous female rats were implanted with osmotic minipumps delivering clinically-relevant concentrations of escitalopram and mated. Pregnant dams were exposed to 12 days of mixed-modality stressors, and offspring were behaviorally assessed in adolescence (postnatal day 28) and adulthood (beyond day 90) to determine the extent of behavioral change. We found that in utero stress exposure, regardless of escitalopram treatment, increased anxiety-like behavior in adolescent females and profoundly influenced amygdala expression of the chloride transporters KCC2 and NKCC1, which regulate GABAergic function. In contrast, prenatal escitalopram exposure alone elevated amygdala expression of 5-HT1A receptors. In adulthood, anxiety-like behavior returned to baseline and gene expression effects in the amygdala abated, whereas deficits emerged in novel object recognition for rats exposed to stress during gestation. These findings suggest prenatal stress causes age-dependent deficits in anxiety-like behavior and amygdala function in female offspring, regardless of antidepressant exposure. PMID:26032436
Lv, Xin; Li, Qiang; Wu, Shun; Sun, Jing; Zhang, Min; Chen, Yong-Jin
Psychological factors can be correlated with temporomandibular disorders (TMDs), but the mechanisms are unknown. In the present study, we examined the microstructural changes and expression of proinflammatory cytokines in mandibular condylar cartilage of the temporomandibular joint (TMJ) in a psychological stress animal model. Male Sprague-Dawley rats (8 weeks old, 210 ± 10 g) were randomly divided into 3 groups: psychological stress (PS, N = 48), foot shock (FS, N = 24), and control (N = 48). After inducing psychological stress using a communication box with the FS rats for 1, 3, or 5 weeks, PS rats were sacrificed and compared to their matched control littermates, which received no stress and were killed at the same times as the PS rats. Body and adrenal gland weight were measured and corticosterone and adrenocorticotropic hormone levels were determined by radioimmunoassay. After hematoxylin-eosin staining for histological observation, the ultrastructure of the TMJ was examined by scanning electron microscopy. Transcription and protein levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were evaluated by ELISA and semi-quantitative RT-PCR. The PS group showed a significantly higher adrenal gland weight after 3 weeks of stress and higher hormone levels at weeks 1, 3, and 5. Histopathological changes and thinning cartilage were apparent at weeks 3 and 5. In the PS group, TNF-α increased at 1, 3, and 5 weeks and IL-1β increased significantly after 1 and 3 weeks of stress, and then decreased to normal levels by 5 weeks. Psychological stress increased plasma hormone levels and RT-PCR indicated increased IL-1β and TNF-α expression in the TMJ in a time-dependent manner. These results suggest that cytokine up-regulation was accompanied by stress-induced cartilage degeneration in the mandibular condyle. The proinflammatory cytokines play a potential role in initiating the cartilage destruction that eventually leads to the TMDs
Lv, Xin; Li, Qiang; Wu, Shun; Sun, Jing; Zhang, Min; Chen, Yong-Jin [Department of General Dentistry and Emergency, School of Stomatology, Fourth Military Medical University, Xi' an, Shaanxi (China)
Psychological factors can be correlated with temporomandibular disorders (TMDs), but the mechanisms are unknown. In the present study, we examined the microstructural changes and expression of proinflammatory cytokines in mandibular condylar cartilage of the temporomandibular joint (TMJ) in a psychological stress animal model. Male Sprague-Dawley rats (8 weeks old, 210 ± 10 g) were randomly divided into 3 groups: psychological stress (PS, N = 48), foot shock (FS, N = 24), and control (N = 48). After inducing psychological stress using a communication box with the FS rats for 1, 3, or 5 weeks, PS rats were sacrificed and compared to their matched control littermates, which received no stress and were killed at the same times as the PS rats. Body and adrenal gland weight were measured and corticosterone and adrenocorticotropic hormone levels were determined by radioimmunoassay. After hematoxylin-eosin staining for histological observation, the ultrastructure of the TMJ was examined by scanning electron microscopy. Transcription and protein levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) were evaluated by ELISA and semi-quantitative RT-PCR. The PS group showed a significantly higher adrenal gland weight after 3 weeks of stress and higher hormone levels at weeks 1, 3, and 5. Histopathological changes and thinning cartilage were apparent at weeks 3 and 5. In the PS group, TNF-α increased at 1, 3, and 5 weeks and IL-1β increased significantly after 1 and 3 weeks of stress, and then decreased to normal levels by 5 weeks. Psychological stress increased plasma hormone levels and RT-PCR indicated increased IL-1β and TNF-α expression in the TMJ in a time-dependent manner. These results suggest that cytokine up-regulation was accompanied by stress-induced cartilage degeneration in the mandibular condyle. The proinflammatory cytokines play a potential role in initiating the cartilage destruction that eventually leads to the TMDs.
Full Text Available Psychological factors can be correlated with temporomandibular disorders (TMDs, but the mechanisms are unknown. In the present study, we examined the microstructural changes and expression of proinflammatory cytokines in mandibular condylar cartilage of the temporomandibular joint (TMJ in a psychological stress animal model. Male Sprague-Dawley rats (8 weeks old, 210 ± 10 g were randomly divided into 3 groups: psychological stress (PS, N = 48, foot shock (FS, N = 24, and control (N = 48. After inducing psychological stress using a communication box with the FS rats for 1, 3, or 5 weeks, PS rats were sacrificed and compared to their matched control littermates, which received no stress and were killed at the same times as the PS rats. Body and adrenal gland weight were measured and corticosterone and adrenocorticotropic hormone levels were determined by radioimmunoassay. After hematoxylin-eosin staining for histological observation, the ultrastructure of the TMJ was examined by scanning electron microscopy. Transcription and protein levels of interleukin-1β (IL-1β and tumor necrosis factor-α (TNF-α were evaluated by ELISA and semi-quantitative RT-PCR. The PS group showed a significantly higher adrenal gland weight after 3 weeks of stress and higher hormone levels at weeks 1, 3, and 5. Histopathological changes and thinning cartilage were apparent at weeks 3 and 5. In the PS group, TNF-α increased at 1, 3, and 5 weeks and IL-1β increased significantly after 1 and 3 weeks of stress, and then decreased to normal levels by 5 weeks. Psychological stress increased plasma hormone levels and RT-PCR indicated increased IL-1β and TNF-α expression in the TMJ in a time-dependent manner. These results suggest that cytokine up-regulation was accompanied by stress-induced cartilage degeneration in the mandibular condyle. The proinflammatory cytokines play a potential role in initiating the cartilage destruction that eventually leads to the TMDs.
Marina, Djordje; Klose, Marianne; Nordenbo, Annette
OBJECTIVE: Severe brain injury poses a risk of developing acute and chronic hypopituitarism. Pituitary hormone alterations developed in the early recovery phase after brain injury may have implications for long-term functional recovery. The objective was to assess the pattern and prevalence...... of pituitary hormone alterations three months after severe brain injury with relation to functional outcome at one year follow-up. DESIGN: Prospective study at a tertiary university referral centre. METHODS: A total of 163 patients admitted to neurorehabilitation after severe traumatic (N=111) or non......-traumatic (N=52) brain injury were included. Main outcome measures were endocrine alterations 3.3 months (median) after the brain injury and their relationship to functioning and ability of the patients at one year follow-up, as measured by Functional Independence Measure and Glasgow Outcome Scale...
Therese A. Kosten
Full Text Available Stress enhances the behavioral effects of cocaine, perhaps via hypothalamic-pituitary-adrenal (HPA axis activity. Yet, compared to Fischer 344 (F344 rats, Lewis rats have hyporesponsive HPA axis function and more readily acquire cocaine self-administration. We hypothesized that stress would differentially affect cocaine behaviors in these strains. The effects of three stressors on the discriminative stimulus and response rate effects of cocaine were investigated. Rats of both strains were trained to discriminate cocaine (10 mg/kg from saline using a two-lever, food-reinforced (FR10 procedure. Immediately prior to cumulative dose (1, 3, 10 mg/kg cocaine test sessions, rats were restrained for 15-min, had 15-min of footshock in a distinct context, or were placed in the shock-paired context. Another set of F344 and Lewis rats were tested similarly except they received vehicle injections to test if stress substituted for cocaine. Most vehicle-tested rats failed to respond after stressor exposures. Among cocaine-tested rats, restraint stress enhanced cocaine’s discriminative stimulus effects in F344 rats. Shock and shock-context increased response rates in Lewis rats. Stress-induced increases in corticosterone levels showed strain differences but did not correlate with behavior. These data suggest that the behavioral effects of cocaine can be differentially affected by stress in a strain-selective manner.
Jia, Xia; Zhao, YongHua; Wang, WenKe; He, Yunhua
The objective of this study was to investigate the effects of slightly elevated atmospheric temperature in the spring on photosynthetic products in wheat seedlings and on organic compounds and biological activity in rhizosphere soil under cadmium (Cd) stress. Elevated temperature was associated with increased soluble sugars, reducing sugars, starch, and total sugars, and with decreased amino acids in wheat seedlings under Cd stress. Elevated temperature improved total soluble sugars, free amino acids, soluble phenolic acids, and organic acids in rhizosphere soil under Cd stress. The activity of amylase, phenol oxidase, invertase, β-glucosidase, and l-asparaginase in rhizosphere soil was significantly improved by elevated temperature under Cd stress; while cellulase, neutral phosphatase, and urease activity significantly decreased. Elevated temperature significantly improved bacteria, fungi, actinomycetes, and total microorganisms abundance and fluorescein diacetate activity under Cd stress. In conclusion, slightly elevated atmospheric temperature in the spring improved the carbohydrate levels in wheat seedlings and organic compounds and biological activity in rhizosphere soil under Cd stress in the short term. In addition, elevated atmospheric temperature in the spring stimulated available Cd by affecting pH, DOC, phenolic acids, and organic acids in rhizosphere soil, which resulted in the improvement of the Cd uptake by wheat seedlings.
Greene, Elizabeth; Khaldi, Stephanie; Ishola, Peter; Bottje, Walter; Ohkubo, Takeshi; Anthony, Nicholas; Dridi, Sami
Orexins (A and B) or hypocretins (1 and 2) are hypothalamic orexigenic neuropeptides that are involved in the regulation of several physiological processes in mammals. Recently, orexin has been shown to activate the hypothalamic-pituitary-adrenal (HPA) stress axis and emerging evidences identify it as a stress modulator in mammals. However, the regulation of