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Sample records for chronic desiccation stress

  1. Desiccation stress induces developmental heterochrony in

    Indian Academy of Sciences (India)

    Stressful environments are known to perturb developmental patterns in insects. In the purview of desiccation as astressor, relatively little is known about the developmental consequences linked with desiccation tolerance. In thisstudy, we have particularly focused on the exploration of the temporal profile of postembryonic ...

  2. Desiccation stress induces developmental heterochrony in ...

    Indian Academy of Sciences (India)

    Stressful environments are known to perturb developmental patterns in insects. In the purview of desiccation as astressor, relatively little is known about the developmental consequences linked with desiccation tolerance. In thisstudy, we have particularly focused on the exploration of the temporal profile of postembryonic ...

  3. Factors Predicting the Ocular Surface Response to Desiccating Environmental Stress

    Science.gov (United States)

    Alex, Anastasia; Edwards, Austin; Hays, J. Daniel; Kerkstra, Michelle; Shih, Amanda; de Paiva, Cintia S.; Pflugfelder, Stephen C.

    2013-01-01

    Purpose. To identify factors predicting the ocular surface response to experimental desiccating stress. Methods. The ocular surfaces of both eyes of 15 normal and 10 dry eye subjects wearing goggles were exposed to a controlled desiccating environment (15%–25% relative humidity and 2–5 L/min airflow) for 90 minutes. Eye irritation symptoms, blink rate, tear meniscus dimensions, noninvasive (RBUT) and invasive tear break-up time, and corneal fluorescein and conjunctival lissamine green-dye staining were recorded before and after desiccating stress. Pre- and postexposure measurements were compared, and Pearson correlations between clinical parameters before and after desiccating stress were calculated. Results. Corneal and conjunctival dye staining significantly increased in all subjects following 90-minute exposure to desiccating environment, and the magnitude of change was similar in normal and dry eye subjects; except superior cornea staining was greater in dry eye. Irritation severity in the desiccating environment was associated with baseline dye staining, baseline tear meniscus height, and blink rate after 45 minutes. Desiccation-induced change in corneal fluorescein staining was inversely correlated to baseline tear meniscus width, whereas change in total ocular surface dye staining was inversely correlated to baseline dye staining, RBUT, and tear meniscus height and width. Blink rate from 30 to 90 minutes in desiccating environment was higher in the dry eye than normal group. Blink rate significantly correlated to baseline corneal fluorescein staining and environmental-induced change in corneal fluorescein staining. Conclusions. Ocular surface dye staining increases in response to desiccating stress. Baseline ocular surface dye staining, tear meniscus height, and blink rate predict severity of ocular surface dye staining following exposure to a desiccating environment. PMID:23572103

  4. Efficacy of Metarhizium anisopliae isolate MAX-2 from Shangri-la, China under desiccation stress.

    Science.gov (United States)

    Chen, Zi-Hong; Xu, Ling; Yang, Feng-lian; Ji, Guang-Hai; Yang, Jing; Wang, Jian-Yun

    2014-01-03

    Metarhizium anisopliae, a soil-borne entomopathogen found worldwide, is an interesting fungus for biological control. However, its efficacy in the fields is significantly affected by environmental conditions, particularly moisture. To overcome the weakness of Metarhizium and determine its isolates with antistress capacity, the efficacies of four M. anisopliae isolates, which were collected from arid regions of Yunnan Province in China during the dry season, were determined at different moisture levels, and the efficacy of the isolate MAX-2 from Shangri-la under desiccation stress was evaluated at low moisture level. M. anisopliae isolates MAX-2, MAC-6, MAL-1, and MAQ-28 showed gradient descent efficacies against sterile Tenebrio molitor larvae, and gradient descent capacities against desiccation with the decrease in moisture levels. The efficacy of MAX-2 showed no significant differences at 35% moisture level than those of the other isolates. However, significant differences were found at 8% to 30% moisture levels. The efficacies of all isolates decreased with the decrease in moisture levels. MAX-2 was relatively less affected by desiccation stress. Its efficacy was almost unaffected by the decrease at moisture levels > 25%, but slowly decreased at moisture levels < 25%. By contrast, the efficacies of other isolates rapidly decreased with the decrease in moisture levels. MAX-2 caused different infection characteristics on T. molitor larvae under desiccation stress and in wet microhabitat. Local black patches were found on the cuticles of the insects, and the cadavers dried without fungal growth under desiccation stress. However, dark black internodes and fungal growth were found after death of the insects in the wet microhabitat. MAX-2 showed significantly higher efficacy and superior antistress capacity than the other isolates under desiccation stress. The infection of sterile T. molitor larvae at low moisture level constituted a valid laboratory bioassay system

  5. Desiccation stress and tolerance in green algae: consequences for ultrastructure, physiological and molecular mechanisms

    Science.gov (United States)

    Holzinger, Andreas; Karsten, Ulf

    2013-01-01

    mechanisms involved in desiccation-stress physiology of these organisms. The very limited existing information is described in the present review. PMID:23986769

  6. Desiccation stress and tolerance in green algae: Consequences for ultrastructure, physiological and molecular mechanisms

    Directory of Open Access Journals (Sweden)

    Andreas eHolzinger

    2013-08-01

    Full Text Available Although most green algae typically occur in aquatic ecosystems, many species also live partly or permanently under aeroterrestrial conditions, where the cells are exposed to the atmosphere and hence regularly experience dehydration. The ability of algal cells to survive in an air-dried state is termed desiccation tolerance. The mechanisms involved in desiccation tolerance of green algae are still poorly understood, and hence the aim of this review is to summarize recent findings on the effects of desiccation and osmotic water loss. Starting from structural changes, physiological and biochemical consequences of desiccation will be addressed in different green-algal lineages. The available data clearly indicate a range of strategies, which are rather different in streptophycean and non-streptophycean green algae. For example, Trebouxiophyceae exhibit effective water loss-prevention mechanisms based on the biosynthesis and accumulation of particular organic osmolytes such as polyols, these compounds are so far not reported in representatives of the Streptophyta. In members of the Streptophyta such as Klebsormidium, the most striking observation is the appearance of cross-walls in desiccated samples, which are strongly undulating, suggesting a high degree of mechanical flexibility. This allows the cell to maintain turgor pressure for a prolonged period of time during the dehydration process. Physiological strategies in aeroterrestrial green algae generally include a rapid reduction of photosynthesis during desiccation, but also a rather quick recovery after rewetting, whereas aquatic species are sensitive to drying. The underlying mechanisms such as the affected molecular components of the photosynthetic machinery are poorly understood in green algae. Therefore, modern approaches based on transcriptomics, proteomics and/or metabolomics are urgently needed to better understand the molecular mechanisms involved in desiccation-stress physiology of

  7. Trehalose as an indicator of desiccation stress in Drosophila melanogaster larvae: A potential marker of anhydrobiosis

    Energy Technology Data Exchange (ETDEWEB)

    Thorat, Leena J. [Centre for Advanced Studies, Department of Zoology, University of Pune, Pune 411007 (India); Gaikwad, Sushama M. [Division of Biochemical Sciences, National Chemical Laboratory, Pune 411008 (India); Nath, Bimalendu B., E-mail: bbnath@unipune.ac.in [Centre for Advanced Studies, Department of Zoology, University of Pune, Pune 411007 (India)

    2012-03-23

    Highlights: Black-Right-Pointing-Pointer First report confirming anhydrobiosis in Drosophila melanogaster larvae. Black-Right-Pointing-Pointer Trehalose synthesis and accumulation in larvae that hydrolyzed on rehydration. Black-Right-Pointing-Pointer Trehalose synthesis in concert with the enzymes involved in trehalose metabolism. Black-Right-Pointing-Pointer Inhibition of trehalose hydrolysis in presence of a specific trehalase inhibitor. Black-Right-Pointing-Pointer Trehalose proposed as a reliable marker for biomonitoring of climate change studies. -- Abstract: In the current scenario of global climate change, desiccation is considered as one of the major environmental stressors for the biota exposed to altered levels of ambient temperature and humidity. Drosophila melanogaster, a cosmopolitan terrestrial insect has been chosen as a humidity-sensitive bioindicator model for the present study since its habitat undergoes frequent stochastic and/or seasonally aggravated dehydration regimes. We report here for the first time the occurrence of anhydrobiosis in D. melanogaster larvae by subjecting them to desiccation stress under laboratory conditions. Larvae desiccated for ten hours at <5% relative humidity could enter anhydrobiosis and could revive upon rehydration followed by resumption of active metabolism. As revealed by FTIR and HPLC analyzes, our findings strongly indicated the synthesis and accumulation of trehalose in the desiccating larvae. Biochemical measurements pointed out the desiccation-responsive trehalose metabolic pathway that was found to be coordinated in concert with the enzymes trehalose 6-phosphate synthase and trehalase. Further, an inhibitor-based experimental approach using deoxynojirimycin, a specific trehalase inhibitor, demonstrated the pivotal role of trehalose in larval anhydrobiosis of D. melanogaster. We therefore propose trehalose as a potential marker for the assessment of anhydrobiosis in Drosophila. The present findings thus add

  8. Trehalose as an indicator of desiccation stress in Drosophila melanogaster larvae: A potential marker of anhydrobiosis

    International Nuclear Information System (INIS)

    Thorat, Leena J.; Gaikwad, Sushama M.; Nath, Bimalendu B.

    2012-01-01

    Highlights: ► First report confirming anhydrobiosis in Drosophila melanogaster larvae. ► Trehalose synthesis and accumulation in larvae that hydrolyzed on rehydration. ► Trehalose synthesis in concert with the enzymes involved in trehalose metabolism. ► Inhibition of trehalose hydrolysis in presence of a specific trehalase inhibitor. ► Trehalose proposed as a reliable marker for biomonitoring of climate change studies. -- Abstract: In the current scenario of global climate change, desiccation is considered as one of the major environmental stressors for the biota exposed to altered levels of ambient temperature and humidity. Drosophila melanogaster, a cosmopolitan terrestrial insect has been chosen as a humidity-sensitive bioindicator model for the present study since its habitat undergoes frequent stochastic and/or seasonally aggravated dehydration regimes. We report here for the first time the occurrence of anhydrobiosis in D. melanogaster larvae by subjecting them to desiccation stress under laboratory conditions. Larvae desiccated for ten hours at <5% relative humidity could enter anhydrobiosis and could revive upon rehydration followed by resumption of active metabolism. As revealed by FTIR and HPLC analyzes, our findings strongly indicated the synthesis and accumulation of trehalose in the desiccating larvae. Biochemical measurements pointed out the desiccation-responsive trehalose metabolic pathway that was found to be coordinated in concert with the enzymes trehalose 6-phosphate synthase and trehalase. Further, an inhibitor-based experimental approach using deoxynojirimycin, a specific trehalase inhibitor, demonstrated the pivotal role of trehalose in larval anhydrobiosis of D. melanogaster. We therefore propose trehalose as a potential marker for the assessment of anhydrobiosis in Drosophila. The present findings thus add to the growing list of novel biochemical markers in specific bioindicator organisms for fulfilling the urgent need of

  9. Correlation between desiccation stress response and epigenetic modifications of genes in Drosophila melanogaster: An example of environment-epigenome interaction.

    Science.gov (United States)

    Sharma, Vineeta; Kohli, Surbhi; Brahmachari, Vani

    2017-10-01

    Animals from different phyla including arthropods tolerate water stress to different extent. This tolerance is accompanied by biochemical changes which in turn are due to transcriptional alteration. The changes in transcription can be an indirect effect on some of the genes, ensuing from the effect of stress on the regulators of transcription including epigenetic regulators. Within this paradigm, we investigated the correlation between stress response and epigenetic modification underlying gene expression modulation during desiccation stress in Canton-S. We report altered resistance of flies in desiccation stress for heterozygote mutants of PcG and TrxG members. Pc/+ mutant shows lower survival, while ash1/+ mutants show higher survival under desiccation stress as compared to Canton-S. We detect expression alteration in stress related genes as well the genes of the Polycomb and trithorax complex in Canton-S subjected to desiccation stress. Concomitant with this, there is an altered enrichment of H3K27me3 and H3K4me3 at the upstream regions of the stress responsive genes. The enrichment of activating mark, H3K4me3, is higher in non-stress condition. H3K27me3, the repressive mark, is more pronounced under stress condition, which in turn, can be correlated with the binding of Pc. Our results show that desiccation stress induces dynamic switching in expression and enrichment of PcG and TrxG in the upstream region of genes, which correlates with histone modifications. We provide evidence that epigenetic modulation could be one of the mechanisms to adapt to the desiccation stress in Drosophila. Thus, our study proposes the interaction of epigenome and environmental factors. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Impact of environmental stress desiccation, acidity, alkalinity, heat or cold on antibiotic susceptibility of Cronobacter sakazakii.

    Science.gov (United States)

    Al-Nabulsi, Anas A; Osaili, Tareq M; Elabedeen, Noor A Zain; Jaradat, Ziad W; Shaker, Reyad R; Kheirallah, Khalid A; Tarazi, Yaser H; Holley, Richard A

    2011-03-30

    Cronobacter sakazakii is an emerging foodborne pathogen that has been implicated in severe forms of meningitis, septicemia or necrotizing colitis in pre-term neonates. Although illness outbreaks (primarily associated with powdered infant formula, PIF) caused by this pathogen are rare, the case-fatality rate may reach 50%. Successful treatment of C. sakazakii infection is reliant upon clinical use of antibiotics (AB) such as ampicillin. Recent reports showed increased resistance of C. sakazakii to broad-spectrum antibiotics. The objective of this study was to evaluate the effect of extreme pH (3.5 for 30 min or 11.25 for 5 min), cold (4°C for 24h), heat (55°C for 5 min), and desiccation (cells were dried at 40°C for 2h and held at 21°C for 4 d) stresses on susceptibility of five isolated strains of C. sakazakii to streptomycin, gentamicin, kanamycin, neomycin, tetracycline, doxycycline, tilmicosin, florfenicol, ampicillin, amoxicillin, vancomycin, ciprofloxacin and enrofloxacin. All unstressed strains of C. sakazakii were sensitive to streptomycin, gentamycin, kanamycin, ciprofloxacin, enrofloxacin, ampicillin and amoxicillin, but were moderately resistant or resistant to the rest. Exposing cells to alkaline or acidic stress did not change their sensitivity toward streptomycin, gentamycin, kanamycin or ciprofloxacin, but their resistance toward the other AB was increased. Cells stressed by desiccation showed increased sensitivity toward streptomycin, gentamicin, kanamycin, ciprofloxacin, enrofloxacin, ampicillin and doxycycline, but showed resistance toward the others. Cold-stressed cells were more sensitive to streptomycin, gentamicin, kanamycin, and ciprofloxacin compared with heat-stressed cells, but both heat and cold-stressed cells showed increased resistance toward all the other AB. Results obtained will help in understanding the effect of environmental stresses during processing on C. sakazakii susceptibility to AB. Copyright © 2011 Elsevier B.V. All

  11. Facing the Heat: Does Desiccation and Thermal Stress Explain Patterns of Orientation in an Intertidal Invertebrate?

    Directory of Open Access Journals (Sweden)

    Clarissa M L Fraser

    Full Text Available A key challenge for ecologists is to quantify, explain and predict the ecology and behaviour of animals from knowledge of their basic physiology. Compared to our knowledge of many other types of distribution and behaviour, and how these are linked to individual function, we have a poor level of understanding of the causal basis for orientation behaviours. Most explanations for patterns of animal orientation assume that animals will modify their exposure to environmental factors by altering their orientation. We used a keystone grazer on rocky shores, the limpet Cellana tramoserica, to test this idea. Manipulative experiments were done to evaluate whether orientation during emersion affected limpet desiccation or body temperature. Body temperature was determined from infrared thermography, a technique that minimises disturbance to the test organism. No causal relationships were found between orientation and (i level of desiccation and (ii their body temperature. These results add to the growing knowledge that responses to desiccation and thermal stress may be less important in modifying the behaviour of intertidal organisms than previously supposed and that thermoregulation does not always reflect patterns of animal orientation. Much of what we understand about orientation comes from studies of animals able to modify orientation over very short time scales. Our data suggests that for animals whose location is less flexible, orientation decisions may have less to do with responses to environmental factors and more to do with structural habitat properties or intrinsic individual attributes. Therefore we suggest future studies into processes affecting orientation must include organisms with differing levels of behavioural plasticity.

  12. Xylem diameter changes during osmotic stress, desiccation and freezing in Pinus sylvestris and Populus tremula.

    Science.gov (United States)

    Lintunen, Anna; Lindfors, Lauri; Nikinmaa, Eero; Hölttä, Teemu

    2017-04-01

    Trees experience low apoplastic water potential frequently in most environments. Low apoplastic water potential increases the risk of embolism formation in xylem conduits and creates dehydration stress for the living cells. We studied the magnitude and rate of xylem diameter change in response to decreasing apoplastic water potential and the role of living parenchyma cells in it to better understand xylem diameter changes in different environmental conditions. We compared responses of control and heat-injured xylem of Pinus sylvestris (L.) and Populus tremula (L.) branches to decreasing apoplastic water potential created by osmotic stress, desiccation and freezing. It was shown that xylem in control branches shrank more in response to decreasing apoplastic water potential in comparison with the samples that were preheated to damage living xylem parenchyma. By manipulating the osmotic pressure of the xylem sap, we observed xylem shrinkage due to decreasing apoplastic water potential even in the absence of water tension within the conduits. These results indicate that decreasing apoplastic water potential led to withdrawal of intracellular water from the xylem parenchyma, causing tissue shrinkage. The amount of xylem shrinkage per decrease in apoplastic water potential was higher during osmotic stress or desiccation compared with freezing. During desiccation, xylem diameter shrinkage involved both dehydration-related shrinkage of xylem parenchyma and water tension-induced shrinkage of conduits, whereas dehydration-related shrinkage of xylem parenchyma was accompanied by swelling of apoplastic ice during freezing. It was also shown that the exchange of water between symplast and apoplast within xylem is clearly faster than previously reported between the phloem and the xylem. Time constant of xylem shrinkage was 40 and 2 times higher during osmotic stress than during freezing stress in P. sylvestris and P. tremula, respectively. Finally, it was concluded that the

  13. Protein and carbohydrate composition of larval food affects tolerance tothermal stress and desiccation in adult Drosophila melanogaster

    DEFF Research Database (Denmark)

    Andersen, Laila H; Kristensen, Torsten N; Loeschcke, Volker

    2010-01-01

    Larval nutrition may affect a range of different life history traits as well as responses to environmental stress in adult insects. Here we test whether raising larvae of fruit flies, Drosophila melanogaster, on two different nutritional regimes affects resistance to cold, heat and desiccation....... In contrast, flies developed on the carbohydrate-enriched growth medium recovered faster from chill coma stress compared to flies developed on a protein-enriched medium. We also found gender differences in stress tolerance, with female flies being more tolerant to chill coma, heat knockdown and desiccation...... stress compared to males. Egg production was highest in females that had developed on the protein-enriched medium. However, there was a sex-specific effect of nutrition on egg-to-adult viability, with higher viability for males developing on the sucrose-enriched medium, while female survival was highest...

  14. The response of foodborne pathogens to osmotic and desiccation stresses in the food chain

    DEFF Research Database (Denmark)

    Burgess, Catherine M.; Gianotti, Andrea; Gruzdev, Nadia

    2016-01-01

    In combination with other strategies, hyperosmolarity and desiccation are frequently used by the food processing industry as a means to prevent bacterial proliferation, and particularly that of foodborne pathogens, in food products. However, it is increasingly observed that bacteria, including...... and identifies gaps in knowledge which need to be addressed to ensure the safety of low water activity and desiccated food products....

  15. Impact of desiccation and heat exposure stress on Salmonella tolerance to acidic conditions.

    Science.gov (United States)

    Richardson, Kurt E; Cox, Nelson A; Cosby, Douglas E; Berrang, Mark E

    2018-02-01

    In a recent study, the pH of commonly used Salmonella pre-enrichment media became acidic (pH 4.0 to 5.0) when feed or feed ingredients were incubated for 24 h. Acidic conditions have been reported to injure or kill Salmonella. In this study, cultures of four known feed isolates (S. montevideo, S. senftenberg, S. tennessee, and S. schwarzengrund) and four important processing plant isolates (S. typhimurium, S. enteritidis, S. infantis, and S. heidelberg) were grown on meat and bone meal and later subjected to desiccation and heat exposure to stress the microorganism. The impact of stress on the isolates ability to survive in acidic conditions ranging from pH 4.0 to 7.0 was compared to the non-stressed isolate. Cell injury was determined on xylose lysine tergitol 4 (XLT4) and cell death determined on nutrient agar (NA). When measured by cell death in non-stressed Salmonella, S. typhimurium was the most acid tolerant and S. heidelberg was the most acid sensitive whereas in stressed Salmonella, S. senftenberg was the most acid tolerant and S. tennessee was the most acid sensitive. The pH required to cause cell injury varied among isolates. With some isolates, the pH required for 50% cell death and 50% cell injury was similar. In other isolates, cell injury occurred at a more neutral pH. These findings suggest that the pH of pre-enrichment media may influence the recovery and bias the serotype of Salmonella recovered from feed during pre-enrichment.

  16. Tolerance to oxidative stress induced by desiccation in Porphyra columbina (Bangiales, Rhodophyta).

    Science.gov (United States)

    Contreras-Porcia, Loretto; Thomas, Daniela; Flores, Verónica; Correa, Juan A

    2011-03-01

    Unravelling the mechanisms underlying desiccation tolerance is crucial in order to understand the position of algal species in the intertidal zone. The alga Porphyra columbina lives in the uppermost part of the rocky intertidal zones around the world and was selected as a model for this study. Naturally desiccated plants were collected during low tide and studied for morphological changes, oxidative burst induction, biomolecule oxidation, antioxidant responses, and photosynthetic status. Naturally hydrated plants collected during high tides were used for comparative purposes. In addition, changes induced by desiccation were assessed in vitro and the capacity to recover from desiccation was determined by rehydrating the fronds in seawater. The global results show that desiccation induces morphological and cellular alterations accompanied by a loss of ∼96% of the water content. Overproduction of reactive oxygen species (ROS) was induced by desiccation and two peaks of H(2)O(2) were detected at 1 and 3 h of desiccation. However, during in vitro rehydration post-desiccation, the ROS quickly returned to the basal levels. At the biomolecular level, only a low production of oxidized proteins was recorded during desiccation, whereas the activity of diverse antioxidant enzymes increased. However, this activity diminished to near basal levels during rehydration. The photosynthetic efficiency (F(v)/F(m)) during desiccation declined by 94-96% of the values recorded in hydrated plants. This reduction was generated by the low levels of trapped energy flux per cross-section (TRo/CS), electron transport flux per CS (ETo/CS), and density of reaction centres (RC/SCo) as well as the chlorophyll content. The inverse pattern was observed for the levels of phycocyanin and phycoerythrin content. F(v)/F(m) and the photosynthetic indicators were restored to normal levels after only 5 min of rehydration. The results indicate that desiccation in P. columbina causes overproduction of ROS

  17. Desiccating Stress-Induced MMP Production and Activity Worsens Wound Healing in Alkali-Burned Corneas

    Science.gov (United States)

    Bian, Fang; Pelegrino, Flavia S. A.; Pflugfelder, Stephen C.; Volpe, Eugene A.; Li, De-Quan; de Paiva, Cintia S.

    2015-01-01

    Purpose To evaluate the effects of dry eye on ocular surface protease activity and sight threatening corneal complications following ocular surface chemical injury. Methods C57BL/6 mice were subjected to unilateral alkali burn (AB) with or without concomitant dry eye for 2 or 5 days. Mice were observed daily for appearance of corneal perforation. Whole corneas were harvested and lysed for RNA extraction. Quantitative real-time PCR was performed to measure expression of inflammation cytokines, matrix metalloproteinases (MMP). Matrix metalloproteinase–9 activity, gelatinase activity, and myeloperoxidase (MPO) activity were evaluated in corneal lysates. Presence of infiltrating neutrophils was evaluated by immunohistochemistry and flow cytometry. Results Eyes subjected to the combined model of AB and dry eye (CM) had 20% sterile corneal perforation rate as soon as 1 day after the initial injury, which increased to 35% by 5 days, delayed wound closure and increased corneal opacity. Increased levels of IL-1β, -6, and MMPs-1, -3, -8, -9, and -13, and chemokine (C-X-C motif) ligand 1 (CSCL1) transcripts were found after 2 days in CM compared with AB corneas. Increased MMP-1, -3, -9, and -13 immunoreactivity and gelatinolytic activity were seen in CM corneas compared with AB. Increased neutrophil infiltration and MPO activity was noted in the CM group compared with AB 2 days post injury. Conclusions Desiccating stress worsens outcome of ocular AB, creating a cytokine and protease storm with greater neutrophil infiltration, increasing the risk of corneal perforation. PMID:26225631

  18. Survival of Salmonella serovars on beef carcasses and molecular mechanisms to survive low temperature stress and desiccation

    DEFF Research Database (Denmark)

    Knudsen, Gitte Maegaard; Thomsen, Line Elnif; Aabo, Søren

    2006-01-01

    . Infantis and S. Newport. This experiment indicates that storage at low temperature of beef carcasses can be used as a reduction strategy for Salmonella spp. in beef. In addition molecular mechanisms to resist low temperature stress and desiccation have been investigated. Mutants in the otsA, rpoS and clp...... at 10°C and 15°C, the ¿clpP mutant was severely affected in ability to form colonies compared to the wildtype. Neither the ¿otsA nor the ¿rpoS were affected in growth or survival at low temperature. In a desiccation model, both the ¿rpoS and ¿clpP mutant were more sensitive than the C5 wildtype...

  19. Chronic Stress and Performance

    Science.gov (United States)

    2011-09-01

    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

  20. Response of Methanogenic Microbial Communities to Desiccation Stress in Flooded and Rain-Fed Paddy Soil from Thailand

    Directory of Open Access Journals (Sweden)

    Andreas Reim

    2017-05-01

    Full Text Available Rice paddies in central Thailand are flooded either by irrigation (irrigated rice or by rain (rain-fed rice. The paddy soils and their microbial communities thus experience permanent or arbitrary submergence, respectively. Since methane production depends on anaerobic conditions, we hypothesized that structure and function of the methanogenic microbial communities are different in irrigated and rain-fed paddies and react differently upon desiccation stress. We determined rates and relative proportions of hydrogenotrophic and aceticlastic methanogenesis before and after short-term drying of soil samples from replicate fields. The methanogenic pathway was determined by analyzing concentrations and δ13C of organic carbon and of CH4 and CO2 produced in the presence and absence of methyl fluoride, an inhibitor of aceticlastic methanogenesis. We also determined the abundance (qPCR of genes and transcripts of bacterial 16S rRNA, archaeal 16S rRNA and methanogenic mcrA (coding for a subunit of the methyl coenzyme M reductase and the composition of these microbial communities by T-RFLP fingerprinting and/or Illumina deep sequencing. The abundances of genes and transcripts were similar in irrigated and rain-fed paddy soil. They also did not change much upon desiccation and rewetting, except the transcripts of mcrA, which increased by more than two orders of magnitude. In parallel, rates of CH4 production also increased, in rain-fed soil more than in irrigated soil. The contribution of hydrogenotrophic methanogenesis increased in rain-fed soil and became similar to that in irrigated soil. However, the relative microbial community composition on higher taxonomic levels was similar between irrigated and rain-fed soil. On the other hand, desiccation and subsequent anaerobic reincubation resulted in systematic changes in the composition of microbial communities for both Archaea and Bacteria. It is noteworthy that differences in the community composition were

  1. Chronic stress and social changes: socioeconomic determination of chronic stress.

    Science.gov (United States)

    Kopp, Mária S; Skrabski, Arpád; Székely, András; Stauder, Adrienne; Williams, Redford

    2007-10-01

    In the last decades in the transforming societies of Central and Eastern Europe, premature mortality increased dramatically, especially among men. Increasing disparities in socioeconomic conditions have been accompanied by a widening socioeconomic gradient in mortality among men. Social cohesion and meaning in life may help to counterbalance the widening gap in material circumstances. Not the difficult social situation in itself, but the subjective experience of relative disadvantage, the prolonged negative emotional state, that is, chronic stress seems to be the most important risk factor. The health consequences of a low socioeconomic situation among men might be mostly explained by chronic stress caused by work and close-partner-related factors, and the toxic components of this interaction are depression and hopelessness. In the case of women, the broader personal and family relations are the most important health-related factors. Weekend workload, low social support at work and low control at work accounted for a large part of variation in male premature cardiovascular mortality rates, whereas job insecurity, high weekend workload, and low control at work contribute most markedly to variations in premature cardiovascular mortality rates among women. There are two general approaches that scientists and practitioners might take: train individuals and groups to use skills that will enable them to cope better with the stressful conditions that are damaging their health; and lobby governments to adopt policies that will result in decreased chronic stress on the societal level.

  2. The use of plant stress biomarkers in assessing the effects of desiccation in zygotic embryos from recalcitrant seeds: challenges and considerations.

    Science.gov (United States)

    Sershen; Varghese, B; Naidoo, C; Pammenter, N W

    2016-05-01

    Zygotic embryos from recalcitrant seeds are sensitive to desiccation. In spite of their sensitivity, rapid partial dehydration is necessary for their successful cryopreservation. However, dehydration to water contents (WCs) that preclude lethal ice crystal formation during cooling and rewarming generally leads to desiccation damage. This study investigated the effects of rapid dehydration on selected stress biomarkers (electrolyte leakage, respiratory competence, rate of protein synthesis, superoxide production, lipid peroxidation, antioxidant activity and degree of cellular vacuolation) in zygotic embryos of four recalcitrant-seeded species. Most biomarkers indicated differences in the levels of stress/damage incurred by embryos dried to WCs 0.4 g·g(-1) , within species; however, these changes were often unrelated to viability and percentage water loss when data for the four species were pooled for regression analyses. Dehydration-induced electrolyte leakage was, however, positively related with percentage water loss, while biomarkers of cellular vacuolation were positively related with both percentage water loss and viability. This suggests that electrolyte leakage and degree of cellular vacuolation can be used to quantify dehydration-induced stress/damage. Biomarkers such as superoxide production, whilst useful in establishing the nature of the dehydration stress incurred may not be able to distinguish the effects of different WCs/drying times. Irrespective of which biomarker is used, the data suggest that understanding differences in desiccation sensitivity across recalcitrant-seeded species will remain a challenge unless these biomarkers are related to a generic desiccation stress index that integrates the effects of percentage water loss and drying time. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  3. Improvement of Outcome Measures of Dry Eye by a Novel Integrin Antagonist in the Murine Desiccating Stress Model.

    Science.gov (United States)

    Krauss, Achim H; Corrales, Rosa M; Pelegrino, Flavia S A; Tukler-Henriksson, Johanna; Pflugfelder, Stephen C; de Paiva, Cintia S

    2015-09-01

    We investigated the effects of GW559090, a novel, competitive, and high-affinity α4 integrin antagonist, in a murine model of dry eye. Through interaction with vascular cell adhesion molecule 1 (VCAM-1) and fibronectin α4β1 integrin is involved in leukocyte trafficking and activation. Female C57BL/6 mice, aged 6 to 8 weeks, were subjected to desiccating stress (DS). Bilateral topical twice daily treatment with GW559090 was compared to vehicle-treated controls. Treatment was initiated at the time of DS induction. Treatment effects were assessed on corneal staining with Oregon Green Dextran (OGD) and expression of inflammatory markers in ocular surface tissues by real time PCR. Dendritic cell activation was measured in draining cervical lymph nodes (CLN) by flow cytometry. Separate groups of mice received GW559090 subcutaneously to evaluate the effects of systemic administration on corneal staining and cells in CLN. Topical GW559090 significantly reduced corneal uptake of OGD compared to vehicle-treated disease controls in a dose-dependent manner (1, 3, 10, and 30 mg/mL) with 30 mg/mL showing the greatest reduction in OGD staining. When administered topically, corneal expression of IL-1α, matrix metalloproteinase (MMP)-9, chemokine ligand 9 (CXCL9), and TGF-β1 was reduced in GW559090-treated eyes. Topical treatment with GW559090 decreased dendritic cell activation in lymph nodes. The effects on corneal staining and cellular composition in CLN were not reproduced by systemic administration of GW559090, suggestive of a local role for integrin antagonism in the treatment of dry eye. The novel α4 integrin antagonist, GW559090, improved outcome measures of corneal staining and ocular surface inflammation in this murine model of dry eye. These results indicate the potential of this novel agent for the treatment of dry eye disease.

  4. Transcriptome-Based Identification of the Desiccation Response Genes in Marine Red Algae Pyropia tenera (Rhodophyta) and Enhancement of Abiotic Stress Tolerance by PtDRG2 in Chlamydomonas.

    Science.gov (United States)

    Im, Sungoh; Lee, Ha-Nul; Jung, Hyun Shin; Yang, Sunghwan; Park, Eun-Jeong; Hwang, Mi Sook; Jeong, Won-Joong; Choi, Dong-Woog

    2017-06-01

    Pyropia tenera (Kjellman) are marine red algae that grow in the intertidal zone and lose more than 90% of water during hibernal low tides every day. In order to identify the desiccation response gene (DRG) in P. tenera, we generated 1,444,210 transcriptome sequences using the 454-FLX platform from the gametophyte under control and desiccation conditions. De novo assembly of the transcriptome reads generated 13,170 contigs, covering about 12 Mbp. We selected 1160 differentially expressed genes (DEGs) in response to desiccation stress based on reads per kilobase per million reads (RPKM) expression values. As shown in green higher plants, DEGs under desiccation are composed of two groups of genes for gene regulation networks and functional proteins for carbohydrate metabolism, membrane perturbation, compatible solutes, and specific proteins similar to higher plants. DEGs that show no significant homology with known sequences in public databases were selected as DRGs in P. tenera. PtDRG2 encodes a novel polypeptide of 159 amino acid residues locating chloroplast. When PtDRG2 was overexpressed in Chlamydomonas, the PtDRG2 confer mannitol and salt tolerance in transgenic cells. These results suggest that Pyropia may possess novel genes that differ from green plants, although the desiccation tolerance mechanism in red algae is similar to those of higher green plants. These transcriptome sequences will facilitate future studies to understand the common processes and novel mechanisms involved in desiccation stress tolerance in red algae.

  5. Longevity factor klotho and chronic psychological stress.

    Science.gov (United States)

    Prather, A A; Epel, E S; Arenander, J; Broestl, L; Garay, B I; Wang, D; Dubal, D B

    2015-06-16

    Chronic psychological stress is associated with accelerated aging and premature morbidity and mortality; however, the biology linking chronic psychological stress and its maladaptive effects remains largely unknown. Klotho is a pleiotropic hormone that regulates the aging process and promotes better brain and body health. Whether klotho is linked to psychosocial stress or its negative impact in humans has not been investigated. To address this gap, we recruited 178 healthy women who were either chronically high-stress maternal caregivers for a child with autism spectrum disorder (n = 90) or low-stress control mothers of a typically developing child (n = 88). We found that women under high chronic stress displayed significantly lower levels of the longevity hormone klotho compared with low-stress controls (t(176) = 2.92, P = 0.004; d = 0.44), and the decrease among those under high stress was age-dependent. In addition, high-stress caregivers who reported more depressive symptoms displayed even lower klotho levels compared with low-stress participants. These findings provide the first evidence that klotho levels are sensitive to psychosocial stressors and raise the possibility that klotho may serve as a novel biological link connecting stress, depression and risk for accelerated disease development. Furthermore, these findings have important implications for understanding the plasticity of the aging process and may represent a therapeutic target for mitigating the deleterious effects of chronic psychological stress on health and well-being.

  6. Effect of UV-B Radiation and Desiccation Stress on Photoprotective Compounds Accumulation in Marine Leptolyngbya sp.

    Science.gov (United States)

    Joshi, Devika; Mohandass, C; Dhale, Mohan

    2018-01-01

    Increased awareness regarding the harmful effects of ultraviolet (UV)-B radiation has led to the search for new sources of natural UV-B protecting compounds. Mycosporine-like amino acids are one of such promising compounds found in several organisms. Cyanobacteria are ideal organisms for isolation of these compounds due to their compatibility and adaptability to thrive under harsh environmental conditions. In the following investigation, we report the production of shinorine in Leptolyngbya sp. isolated from the intertidal region. Based on the spectral characteristics and liquid chromatography-mass spectrometry analysis, the UV-absorbing compound was identified as shinorine. To the best of our knowledge, this is the first report on the occurrence of shinorine in Leptolyngbya sp. We also investigated the effect of artificial UV-B radiation and periodic desiccation on chlorophyll-a, total carotenoids, and mycosporine-like amino acids (MAAs) production. The UV-B radiation had a negative effect on growth and chlorophyll concentration, whereas it showed an inductive effect on the production of total carotenoids and MAAs. Desiccation along with UV-B radiation led to an increase in the concentration of photoprotective compounds. These results indicate that carotenoids and MAAs thus facilitate cyanobacteria to avoid and protect themselves from the deleterious effects of UV-B and desiccation.

  7. Glutathione reductase in leaves of cowpea: cloning of two cDNAs, expression and enzymatic activity under progressive drought stress, desiccation and abscisic acid treatment.

    Science.gov (United States)

    Contour-Ansel, Dominique; Torres-Franklin, Maria Lucia; Cruz DE Carvalho, Maria Helena; D'Arcy-Lameta, Agnès; Zuily-Fodil, Yasmine

    2006-12-01

    Reactive oxygen species are frequently produced when plants are exposed to abiotic stresses. Among the detoxication systems, two enzymes, ascorbate peroxidase and glutathione reductase (GR) play key roles. GR has also a central role in keeping the reduced glutathione pool during stress thus allowing the adjustments on the cellular redox reactions. The aim of this work was to study the variations in cytosolic and dual-targeted GR gene expression in the leaves of cowpea plants submitted to progressive drought, rapid desiccation and application of exogenous abscisic acid (ABA). Two cowpea (Vigna unguiculata) cultivars, one drought-resistant ('EPACE-1'), the other drought-sensitive ('1183') were submitted to progressive drought stress by withholding irrigation. Cut-off leaves were air-dried or treated with exogenous ABA. Two GR cDNAs, one cytosolic, the other dual-targeted to chloroplasts and mitochondria were isolated by PCR and cloned in plasmid vectors. Reverse-transcription PCR was used to study the variations in GR gene expression. Two new cDNAs encoding a putative dual-targeted and a cytosolic GR were cloned and sequenced from leaves of V. unguiculata. Drought stress induced an up-regulation of the expression of the cytosolic GR gene directly related to the intensity of the stress in both cultivars. The expression of dual-targeted GR was up-regulated by the drought treatment in the susceptible cultivar only. Under a fast desiccation, the '1183' cultivar responded later than the 'EPACE-1', although in 'EPACE-1' it was the cytosolic isoform which responded and in '1183' the dual-targeted one. Exogenous ABA enhanced significantly the activity and expression levels of GR in both cultivars after treatment for 24 h. These results demonstrate a noticeable activation in both cultivars of the antioxidant metabolism under a progressive water stress, which involves both GR genes in the case of the susceptible cultivar. Under a fast desiccation, the susceptible cultivar

  8. Blunted stress reactivity in chronic cannabis users.

    Science.gov (United States)

    Cuttler, Carrie; Spradlin, Alexander; Nusbaum, Amy T; Whitney, Paul; Hinson, John M; McLaughlin, Ryan J

    2017-08-01

    One of the most commonly cited reasons for chronic cannabis use is to cope with stress. Consistent with this, cannabis users have shown reduced emotional arousal and dampened stress reactivity in response to negative imagery. To our knowledge, the present study represents the first to examine the effects of an acute stress manipulation on subjective stress and salivary cortisol in chronic cannabis users compared to non-users. Forty cannabis users and 42 non-users were randomly assigned to complete either the stress or no stress conditions of the Maastricht Acute Stress Test (MAST). The stress condition of the MAST manipulates both physiological (placing hand in ice bath) and psychosocial stress (performing math under conditions of social evaluation). Participants gave baseline subjective stress ratings before, during, and after the stress manipulation. Cortisol was measured from saliva samples obtained before and after the stress manipulation. Further, cannabis cravings and symptoms of withdrawal were measured. Subjective stress ratings and cortisol levels were significantly higher in non-users in the stress condition relative to non-users in the no stress condition. In contrast, cannabis users demonstrated blunted stress reactivity; specifically, they showed no increase in cortisol and a significantly smaller increase in subjective stress ratings. The stress manipulation had no impact on cannabis users' self-reported cravings or withdrawal symptoms. Chronic cannabis use is associated with blunted stress reactivity. Future research is needed to determine whether this helps to confer resiliency or vulnerability to stress-related psychopathology as well as the mechanisms underlying this effect.

  9. Stress, intrusive imagery, and chronic distress

    International Nuclear Information System (INIS)

    Baum, A.

    1990-01-01

    Discusses the nature of stress in the context of problems with its definition and sources of confusion regarding its usefulness and specificity. Stress can be defined as a negative emotional experience accompanied by predictable biochemical, physiological, and behavioral changes that are directed toward adaptation either by manipulating the situation to alter the stressor or by accommodating its effects. Chronic stress is more complex than most definitions suggest and is clearly not limited to situations in which stressors persist for long periods of time. Responses may habituate before a stressor disappears or may persist long beyond the physical presence of the stressor. This latter case, in which chronic stress and associated biobehavioral changes outlast their original cause, is considered in light of research at Three Mile Island and among Vietnam veterans. The role of intrusive images of the stressor or uncontrollable thoughts about it in maintaining stress is explored

  10. Neural Control of Chronic Stress Adaptation

    Directory of Open Access Journals (Sweden)

    James eHerman

    2013-08-01

    Full Text Available Stress initiates adaptive processes that allow the organism to physiologically cope with prolonged or intermittent exposure to real or perceived threats. A major component of this response is repeated activation of glucocorticoid secretion by the hypothalamo-pituitary-adrenocortical (HPA axis, which promotes redistribution of energy in a wide range of organ systems, including the brain. Prolonged or cumulative increases in glucocorticoid secretion can reduce benefits afforded by enhanced stress reactivity and eventually become maladaptive. The long-term impact of stress is kept in check by the process of habituation, which reduces HPA axis responses upon repeated exposure to homotypic stressors and likely limits deleterious actions of prolonged glucocorticoid secretion. Habituation is regulated by limbic stress-regulatory sites, and is at least in part glucocorticoid feedback-dependent. Chronic stress also sensitizes reactivity to new stimuli. While sensitization may be important in maintaining response flexibility in response to new threats, it may also add to the cumulative impact of glucocorticoids on the brain and body. Finally, unpredictable or severe stress exposure may cause long-term and lasting dysregulation of the HPA axis, likely due to altered limbic control of stress effector pathways. Stress-related disorders, such as depression and PTSD, are accompanied by glucocorticoid imbalances and structural/ functional alterations in limbic circuits that resemble those seen following chronic stress, suggesting that inappropriate processing of stressful information may be part of the pathological process.

  11. Airway oxidative stress in chronic cough

    Science.gov (United States)

    2013-01-01

    Background The mechanisms of chronic cough are unclear. Many reactive oxygen species affect airway sensory C-fibres which are capable to induce cough. Several chronic lung diseases are characterised by cough and oxidative stress. In asthma, an association between the cough severity and airway oxidative stress has been demonstrated. The present study was conducted to investigate whether airway oxidative stress is associated with chronic cough in subjects without chronic lung diseases. Methods Exhaled breath condensate samples were obtained in 43 non-smoking patients with chronic cough and 15 healthy subjects. Exclusion criteria included a doctor’s diagnosis of any lung disorders and any abnormality in lung x-ray. The concentration of 8-isoprostane was measured. In addition, the patients filled in Leicester Cough Questionnaire and underwent hypertonic saline cough provocation test, spirometry, ambulatory peak flow monitoring, nitric oxide measurement, and histamine airway challenge. In a subgroup of patients the measurements were repeated during 12 weeks’ treatment with inhaled budesonide, 800 ug/day. Results The 8-isoprostane concentrations were higher in the cough patients than in the healthy subjects (24.6 ± 1.2 pg/ml vs. 10.1 ± 1.7 pg/ml, p = 0.045). The 8-isoprostane concentration was associated with the Leicester Cough Questionnaire total score (p = 0.044) but not with the cough sensitivity to saline or other tests. Budesonide treatment did not affect the 8-isoprostane concentrations. Conclusions Chronic cough seems to be associated with airway oxidative stress in subjects with chronic cough but without chronic lung diseases. This finding may help to develop novel antitussive drugs. Trial registration The study was registered in ClinicalTrials.gov database (KUH5801112), identifier NCT00859274. PMID:24294924

  12. Glucocorticoids, chronic stress, and obesity

    NARCIS (Netherlands)

    Dallman, Mary F.; Pecoraro, Norman C.; la Fleur, Susanne E.; Warne, James P.; Ginsberg, Abigail B.; Akana, Susan F.; Laugero, Kevin C.; Houshyar, Hani; Strack, Alison M.; Bhatnagar, Seema; Bell, Mary E.

    2006-01-01

    Glucocorticoids either inhibit or sensitize stress-induced activity in the hypothalamo-pituitary-adrenal (HPA) axis, depending on time after their administration, the concentration of the steroids, and whether there is a concurrent stressor input. When there are high glucocorticoids together with a

  13. Pathogenesis of Chronic Hyperglycemia: From Reductive Stress to Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Liang-Jun Yan

    2014-01-01

    Full Text Available Chronic overnutrition creates chronic hyperglycemia that can gradually induce insulin resistance and insulin secretion impairment. These disorders, if not intervened, will eventually be followed by appearance of frank diabetes. The mechanisms of this chronic pathogenic process are complex but have been suggested to involve production of reactive oxygen species (ROS and oxidative stress. In this review, I highlight evidence that reductive stress imposed by overflux of NADH through the mitochondrial electron transport chain is the source of oxidative stress, which is based on establishments that more NADH recycling by mitochondrial complex I leads to more electron leakage and thus more ROS production. The elevated levels of both NADH and ROS can inhibit and inactivate glyceraldehyde 3-phosphate dehydrogenase (GAPDH, respectively, resulting in blockage of the glycolytic pathway and accumulation of glycerol 3-phospate and its prior metabolites along the pathway. This accumulation then initiates all those alternative glucose metabolic pathways such as the polyol pathway and the advanced glycation pathways that otherwise are minor and insignificant under euglycemic conditions. Importantly, all these alternative pathways lead to ROS production, thus aggravating cellular oxidative stress. Therefore, reductive stress followed by oxidative stress comprises a major mechanism of hyperglycemia-induced metabolic syndrome.

  14. Desiccation resistance in Arcobacter butzleri

    Directory of Open Access Journals (Sweden)

    Otth Laura

    2001-01-01

    Full Text Available The desiccation resistance of A. butzleri was studied. Two, 3 and 4 of the strains did not resist desiccation for more than 2, 12 and 36 h, respectively. Two strains resisted desiccation for > 48 h. A. butzleri seems to be more resistant to desiccation than the classical enteropathogenic Campylobacter species.

  15. Multi-Axis Niche Examination of Ecological Specialization: Responses to Heat, Desiccation and Starvation Stress in Two Species of Pit-Building Antlions

    Science.gov (United States)

    Rotkopf, Ron; Barkae, Erez David; Bar-Hanin, Einav; Alcalay, Yehonatan; Ovadia, Ofer

    2012-01-01

    Classical ecological studies discussing specialization usually focus on species’ performance along one niche axis. This approach may overlook niche differentiation evident in another dimension which could explain species co-occurrence. The present research exemplifies a comprehensive approach to examining local adaptation. Specifically, we examined multiple niche axes by subjecting a model organism to various experimental conditions to monitor responses to extreme stress associated with heat, desiccation and starvation. Our model system comprised two pit-building antlions: the habitat generalist Myrmeleon hyalinus and the habitat specialist Cueta lineosa. Previous research has shown that the foraging performance of the generalist is better than that of the specialist, even in the latter’s characteristic habitat. We illustrate that this apparent superiority of the habitat generalist does not manifest itself along other niche axes; rather, the habitat specialist holds a set of traits that provide an advantage under harsh environmental conditions. Specifically, C. lineosa has an advantage over M. hyalinus at high temperatures, exhibiting a higher survival rate and improved foraging success (i.e., high-temperature specialist). C. lineosa is also more efficient in its energy budget, losing less mass during starvation and gaining mass more efficiently during feeding. This superior efficiency is a result of physiological adaptations as well as behavioural responses to harsh conditions. In conclusion, our results imply that the habitat specialization of C. lineosa has not led it towards an evolutionary dead-end. PMID:23209835

  16. Dyshomeostasis, obesity, addiction and chronic stress

    Directory of Open Access Journals (Sweden)

    David F Marks

    2016-03-01

    Full Text Available When eating control is overridden by hedonic reward, a condition of obesity dyshomeostasis occurs. Appetitive hedonic reward is a natural response to an obesogenic environment containing endemic stress and easily accessible and palatable high-energy foods and beverages. Obesity dyshomeostasis is mediated by the prefrontal cortex, amygdala and hypothalamic–pituitary–adrenal axis. The ghrelin axis provides the perfect signalling system for feeding dyshomeostasis, affect control and hedonic reward. Dyshomeostasis plays a central role in obesity causation, the addictions and chronic conditions and in persons with diverse bodies. Prevention and treatment efforts that target sources of dyshomeostasis provide ways of reducing adiposity, ameliorating the health impacts of addiction and raising the quality of life in people suffering from chronic stress.

  17. Stress modulation in desiccating crack networks for producing effective templates for patterning metal network based transparent conductors

    Science.gov (United States)

    Kumar, Ankush; Pujar, Rajashekhar; Gupta, Nikita; Tarafdar, Sujata; Kulkarni, Giridhar U.

    2017-07-01

    A drying layer of a colloidal dispersion tends to produce cracks, often in a network, due to internal stress arising from the rearrangement of particles while the substrate adhesion resists such movements. The stress can be modulated using experimental agents such as electric field, humidity, and surface structuring. In this work, repeated wet-drying cycles of the cracking layer have been used as stress modulating agents taking an aqueous dispersion of acrylic resin nanoparticles as the colloidal layer, offering cracks with widths in the sub-ten micrometer range. With increasing wet-drying cycles, the colloidal layer is seen to develop higher crack density and connectivity, as well as a well-defined hierarchy of formation. Thus developed crack layers have been used as templates for depositing metals (Cu and Au) to realize fine metal wire meshes. The latter serve as transparent conductors with excellent optoelectronic properties.

  18. Trehalose Accumulation Triggers Autophagy during Plant Desiccation.

    Directory of Open Access Journals (Sweden)

    Brett Williams

    2015-12-01

    Full Text Available Global climate change, increasingly erratic weather and a burgeoning global population are significant threats to the sustainability of future crop production. There is an urgent need for the development of robust measures that enable crops to withstand the uncertainty of climate change whilst still producing maximum yields. Resurrection plants possess the unique ability to withstand desiccation for prolonged periods, can be restored upon watering and represent great potential for the development of stress tolerant crops. Here, we describe the remarkable stress characteristics of Tripogon loliiformis, an uncharacterised resurrection grass and close relative of the economically important cereals, rice, sorghum, and maize. We show that T. loliiformis survives extreme environmental stress by implementing autophagy to prevent Programmed Cell Death. Notably, we identified a novel role for trehalose in the regulation of autophagy in T.loliiformis. Transcriptome, Gas Chromatography Mass Spectrometry, immunoblotting and confocal microscopy analyses directly linked the accumulation of trehalose with the onset of autophagy in dehydrating and desiccated T. loliiformis shoots. These results were supported in vitro with the observation of autophagosomes in trehalose treated T. loliiformis leaves; autophagosomes were not detected in untreated samples. Presumably, once induced, autophagy promotes desiccation tolerance in T.loliiformis, by removal of cellular toxins to suppress programmed cell death and the recycling of nutrients to delay the onset of senescence. These findings illustrate how resurrection plants manipulate sugar metabolism to promote desiccation tolerance and may provide candidate genes that are potentially useful for the development of stress tolerant crops.

  19. Chronic pain, perceived stress, and cellular aging: an exploratory study

    Directory of Open Access Journals (Sweden)

    Sibille Kimberly T

    2012-02-01

    Full Text Available Abstract Background Chronic pain conditions are characterized by significant individual variability complicating the identification of pathophysiological markers. Leukocyte telomere length (TL, a measure of cellular aging, is associated with age-related disease onset, psychosocial stress, and health-related functional decline. Psychosocial stress has been associated with the onset of chronic pain and chronic pain is experienced as a physical and psychosocial stressor. However, the utility of TL as a biological marker reflecting the burden of chronic pain and psychosocial stress has not yet been explored. Findings The relationship between chronic pain, stress, and TL was analyzed in 36 ethnically diverse, older adults, half of whom reported no chronic pain and the other half had chronic knee osteoarthritis (OA pain. Subjects completed a physical exam, radiographs, health history, and psychosocial questionnaires. Blood samples were collected and TL was measured by quantitative polymerase chain reaction (qPCR. Four groups were identified characterized by pain status and the Perceived Stress Scale scores: 1 no pain/low stress, 2 no pain/high stress, chronic pain/low stress, and 4 chronic pain/high stress. TL differed between the pain/stress groups (p = 0.01, controlling for relevant covariates. Specifically, the chronic pain/high stress group had significantly shorter TL compared to the no pain/low stress group. Age was negatively correlated with TL, particularly in the chronic pain/high stress group (p = 0.03. Conclusions Although preliminary in nature and based on a modest sample size, these findings indicate that cellular aging may be more pronounced in older adults experiencing high levels of perceived stress and chronic pain.

  20. Domains of Chronic Stress and Suicidal Behaviors among Inpatient Adolescents

    Science.gov (United States)

    Pettit, Jeremy W.; Green, Kelly L.; Grover, Kelly E.; Schatte, Dawnelle J.; Morgan, Sharon T.

    2011-01-01

    Little is known about the role of chronic stress in youth suicidal behaviors. This study examined the relations between specific domains of chronic stress and suicidal behaviors among 131 inpatient youth (M age = 15.02 years) who completed measures of stress, suicidal ideation, suicide attempt, and suicide intent. After controlling for…

  1. Introduction to desiccation biology: from old borders to new frontiers.

    Science.gov (United States)

    Leprince, Olivier; Buitink, Julia

    2015-08-01

    A special issue reviews the recent progress made in our understanding of desiccation tolerance across various plant and animal kingdoms. It has been known for a long time that seeds can survive near absolute protoplasmic dehydration through air drying and complete germination upon rehydration because of their desiccation tolerance. This property is present both in prokaryotes and eukaryotes across all life kingdoms. These dry organisms suspend their metabolism when dry, are extremely tolerant to acute environmental stresses and are relatively stable during long periods of desiccation. Studies aiming at understanding the mechanisms of survival in the dry state have emerged during the past 40 years, moving from in vitro to genomic models and comparative genomics, and from a view that tolerance is an all-or-nothing phenomenon to a quantitative trait. With the prospect of global climate change, understanding the mechanisms of desiccation tolerance appears to be a promising avenue as a prelude to engineering crops for improved drought tolerance. Understanding desiccation is also useful for seed banks that rely on dehydration tolerance to preserve plant genetic resources in the form of these propagules. Articles in this special issue explore the recent progress in our understanding of desiccation tolerance, including the evolutionary mechanisms that have been adopted across various plant (algae, lichens, seeds, resurrection plants) and animal model systems (Caenorhabditis elegans, brine shrimp). We propose that the term desiccation biology defines the discipline dedicated to understand the desiccation tolerance in living organisms as well as the limits and time constraints thereof.

  2. A neuroplasticity hypothesis of chronic stress in the basolateral amygdala.

    Science.gov (United States)

    Boyle, Lara M

    2013-06-01

    Chronic stress plays a role in the etiology of several affective and anxiety-related disorders. Despite this, its mechanistic effects on the brain are still unclear. Of particular interest is the effect of chronic stress on the amygdala, which plays a key role in the regulation of emotional responses and memory consolidation. This review proposes a neuroplasticity model for the effects of chronic stress in this region, emphasizing the roles of glutamate and BDNF signaling. This model provides a review of recent discoveries of the effects of chronic stress in the amygdala and reveals pathways for future research.

  3. Acute stress does not affect the impairing effect of chronic stress on memory retrieval

    Science.gov (United States)

    Ozbaki, Jamile; Goudarzi, Iran; Salmani, Mahmoud Elahdadi; Rashidy-Pour, Ali

    2016-01-01

    Objective(s): Due to the prevalence and pervasiveness of stress in modern life and exposure to both chronic and acute stresses, it is not clear whether prior exposure to chronic stress can influence the impairing effects of acute stress on memory retrieval. This issue was tested in this study. Materials and Methods: Adult male Wistar rats were randomly assigned to the following groups: control, acute, chronic, and chronic + acute stress groups. The rats were trained with six trials per day for 6 consecutive days in the water maze. Following training, the rats were either kept in control conditions or exposed to chronic stress in a restrainer 6 hr/day for 21 days. On day 22, a probe test was done to measure memory retention. Time spent in target and opposite areas, platform location latency, and proximity were used as indices of memory retention. To induce acute stress, 30 min before the probe test, animals received a mild footshock. Results: Stressed animals spent significantly less time in the target quadrant and more time in the opposite quadrant than control animals. Moreover, the stressed animals showed significantly increased platform location latency and proximity as compared with control animals. No significant differences were found in these measures among stress exposure groups. Finally, both chronic and acute stress significantly increased corticosterone levels. Conclusion: Our results indicate that both chronic and acute stress impair memory retrieval similarly. Additionally, the impairing effects of chronic stress on memory retrieval were not influenced by acute stress. PMID:27635201

  4. Composite desiccant structure

    Science.gov (United States)

    Fraioli, Anthony V.; Schertz, William W.

    1987-01-01

    A composite formed of small desiccant particles retained in a dark matrix composed of a porous binder containing a transition metal oxide with pores to provide moisture transport with respect to the particles, and metallic fibers to remove the heat of condensation during dehumidification and provide heat for the removal of moisture during regeneration. The moisture absorbing properties of the composite may be regenerated by exposure of the dark matrix to solar radiation with dehumidification occurring at night.

  5. Extended periods of hydration do not elicit dehardening to desiccation tolerance in regeneration trials of the moss Syntrichia caninervis

    Science.gov (United States)

    Dehardening (deacclimation) to water stress is seldom studied in plants, and yet is an integral phase of desiccation tolerance. Most bryophytes are desiccation tolerant (DT), and yet even fully DT species lose a significant portion of their ability to withstand desiccation if dehardened. Shoots of t...

  6. Exploring the mechanism of Physcomitrella patens desiccation tolerance through a proteomic strategy.

    Science.gov (United States)

    Wang, Xiao Qin; Yang, Ping Fang; Liu, Zheng; Liu, Wei Zhong; Hu, Yong; Chen, Hui; Kuang, Ting Yun; Pei, Zhen Ming; Shen, Shi Hua; He, Yi Kun

    2009-04-01

    The moss Physcomitrella patens has been shown to tolerate abiotic stresses, including salinity, cold, and desiccation. To better understand this plant's mechanism of desiccation tolerance, we have applied cellular and proteomic analyses. Gametophores were desiccated over 1 month to 10% of their original fresh weight. We report that during the course of dehydration, several related processes are set in motion: plasmolysis, chloroplast remodeling, and microtubule depolymerization. Despite the severe desiccation, the membrane system maintains integrity. Through two-dimensional gel electrophoresis and image analysis, we identified 71 proteins as desiccation responsive. Following identification and functional categorization, we found that a majority of the desiccation-responsive proteins were involved in metabolism, cytoskeleton, defense, and signaling. Degradation of cytoskeletal proteins might result in cytoskeletal disassembly and consequent changes in the cell structure. Late embryogenesis abundant proteins and reactive oxygen species-scavenging enzymes are both prominently induced, and they might help to diminish the damage brought by desiccation.

  7. Responses to desiccation stress in bryophytes and an important role of dithiothreitol-insensitive non-photochemical quenching against photoinhibition in dehydrated states.

    Science.gov (United States)

    Nabe, Hayase; Funabiki, Ryoko; Kashino, Yasuhiro; Koike, Hiroyuki; Satoh, Kazuhiko

    2007-11-01

    The effects of air drying and hypertonic treatments in the dark on seven bryophytes, which had grown under different water environments, were studied. All the desiccation-tolerant species tested lost most of their PSII photochemical activity when photosynthetic electron transport was inhibited by air drying, while, in all the sensitive species, the PSII photochemical activity remained at a high level even when photosynthesis was totally inhibited. The PSI reaction center remained active under drying conditions in both sensitive and tolerant species, but the activity became non-detectable in the light only in tolerant species due to deactivation of the cyclic electron flow around PSI and of the back reaction in PSI. Light-induced non-photochemical quenching (NPQ) was found to be induced not only by the xanthophyll cycle but also by a DeltapH-induced, dithiothreitol-insensitive mechanism in both the desiccation-tolerant and -intolerant bryophytes. Both mechanisms are thought to have an important role in protecting desiccation-tolerant species from photoinhibition under drying conditions. Fluorescence emission spectra at 77K showed that dehydration-induced quenching of PSII fluorescence was observed only in tolerant species and was due to neither state 1-state 2 transition nor detachment of light-harvesting chlorophyll protein complexes from PSII core complexes. The presence of dehydration-induced quenching of PSI fluorescence was also suggested.

  8. Acute Stress Decreases but Chronic Stress Increases Myocardial Sensitivity to Ischemic Injury in Rodents

    OpenAIRE

    Eisenmann, Eric D.; Rorabaugh, Boyd R.; Zoladz, Phillip R.

    2016-01-01

    Cardiovascular disease is the largest cause of mortality worldwide, and stress is a significant contributor to the development of cardiovascular disease. The relationship between acute and chronic stress and cardiovascular disease is well-evidenced. Acute stress can lead to arrhythmias and ischemic injury. However, recent evidence in rodent models suggests that acute stress can decrease sensitivity to myocardial ischemia-reperfusion injury. Conversely, chronic stress is arrythmogenic and incr...

  9. Chronic administration of quercetin prevent spatial learning and memory deficits provoked by chronic stress in rats.

    Science.gov (United States)

    Mohammadi, Hadis Said; Goudarzi, Iran; Lashkarbolouki, Taghi; Abrari, Kataneh; Elahdadi Salmani, Mahmoud

    2014-08-15

    There are several reports that cognitive impairment is observed in stress related disorders and chronic stress impairs learning and memory. However, very few studies have looked into the possible ways of preventing this stress-induced deficit. This research study was conducted to evaluate the effects of quercetin, a natural flavonoid, with strong antioxidant and free radical scavenger properties, on chronic stress induced learning and memory deficits and oxidative stress in hippocampus. For chronic stress, rats were restrained daily for 6h/day (from 9:00 to 15:00) for 21 days in well-ventilated plexiglass tubes without access to food and water. The animals were injected with quercetin or vehicle 60 min before restraint stress over a period of 21 days. Then, rats trained with six trials per day for 6 consecutive days in the water maze. On day 28, a probe test was done to measure memory retention. In addition, oxidative stress markers in the hippocampus were evaluated. Results of this study demonstrated that chronic stress exposure rats exhibited higher escape latency during training trials and reduced time spent in target quadrant, higher escape location latency and average proximity in probe trial test. Quercetin (50mg/kg) treatment during restraint stress (21 days) markedly decreased escape latency and increased time spent in target quadrant during Morris water maze task. In comparison to vehicle treated group, chronic-stress group had significantly higher malondialdehyde (MDA) levels, significantly higher superoxide dismutase (SOD) activity and significantly lower glutathione peroxidase (GPx) activity in the hippocampus. Quercetin treatment caused a significant decrease in the hippocampus MDA levels and improves SOD and GPx activities in stressed animals. Finally, quercetin significantly decreased plasma corticosterone levels in stressed animals. Based on results of this study, chronic stress has detrimental effects on learning and memory and quercetin treatment

  10. Chronic stress, catecholamines, and sleep disturbance at Three Mile Island.

    Science.gov (United States)

    Davidson, L M; Fleming, R; Baum, A

    1987-01-01

    The present study was concerned with the relationship between chronic stress and sleep disturbance. Previous research has provided evidence of chronic stress responding among people living near the Three Mile Island nuclear generating facility. Compared to control subjects, the TMI group has exhibited greater symptom reporting, poorer performance on behavioral measures of concentration, and elevated levels of urinary norepinephrine and epinephrine. Other research has suggested a relationship between arousal and insomnia. The extent to which stress and sleep disturbances were experienced by residents at TMI was examined and compared to levels of stress and sleep disturbance among a group of control subjects. The relationship between stress and sleep disturbances was also examined. Results indicated that TMI area residents exhibited more stress than the controls and reported greater disturbance of sleep. Modest relationships among stress and sleep measures suggested that the symptoms of stress measured in this study were not primary determinants of sleep problems.

  11. Chronic stress, catecholamines, and sleep disturbance at Three Mile Island

    International Nuclear Information System (INIS)

    Davidson, L.M.; Fleming, R.; Baum, A.

    1987-01-01

    The present study was concerned with the relationship between chronic stress and sleep disturbance. Previous research has provided evidence of chronic stress responding among people living near the Three Mile Island nuclear generating facility. Compared to control subjects, the TMI group has exhibited greater symptom reporting, poorer performance on behavioral measures of concentration, and elevated levels of urinary norepinephrine and epinephrine. Other research has suggested a relationship between arousal and insomnia. The extent to which stress and sleep disturbances were experienced by residents at TMI was examined and compared to levels of stress and sleep disturbance among a group of control subjects. The relationship between stress and sleep disturbances was also examined. Results indicated that TMI area residents exhibited more stress than the controls and reported greater disturbance of sleep. Modest relationships among stress and sleep measures suggested that the symptoms of stress measured in this study were not primary determinants of sleep problems

  12. Enhanced Desiccation Tolerance In Mature Cultures Of The Streptophytic Green Alga Zygnema circumcarinatum Revealed By Transcriptomics

    OpenAIRE

    Rippin, Martin; Becker, Burkhard; Holzinger, Andreas

    2017-01-01

    Desiccation tolerance is commonly regarded as one of the key features for the colonization of terrestrial habitats by green algae and the evolution of land plants. Extensive studies, focused mostly on physiology, have been carried out assessing the desiccation tolerance and resilience of the streptophytic genera Klebsormidium and Zygnema. Here we present transcriptomic analyses of Zygnema circumcarinatum exposed to desiccation stress. Cultures of Z. circumcarinatum, grown in liquid medium or ...

  13. Metabolic consequences of chronic intermittent mild stress exposure.

    Science.gov (United States)

    Thompson, Abigail K; Fourman, Sarah; Packard, Amy E B; Egan, Ann E; Ryan, Karen K; Ulrich-Lai, Yvonne M

    2015-10-15

    Chronic stress in humans has divergent effects on food intake, with some individuals reporting increased vs. decreased food intake during stress. This divergence may depend in part on stress intensity, with higher-intensity stressors preferentially promoting anorexia. Consistent with this idea, rodents given a high-intensity chronic variable stress paradigm have robustly decreased food intake and body weight gain. However, the metabolic effects of a less intense chronic stress paradigm are not clear. Thus in the present study, adult male rats were given chronic intermittent mild stress (CIMS) exposure (3 cycles, in which each cycle consists of once daily mild stress for 5 days/week for 2 weeks, followed by 2 weeks of no stress) vs. non-stress controls, combined with ongoing access to a palatable diet (PD; choice of chow, high-fat diet, 30% sucrose drink, and water) vs. control diet (chow and water). As expected, access to PD increased caloric intake, body weight gain, and adiposity, and impaired glucose tolerance. CIMS decreased body weight gain only during the first cycle of stress and did not affect body weight gain thereafter, regardless of diet. Moreover, CIMS did not alter total food intake, adiposity or glucose tolerance regardless of diet. Lastly, CIMS transiently increased high-fat diet preference in PD-fed rats during the first stress cycle. Collectively, these results suggest that CIMS has relatively modest metabolic effects that occur primarily during initial stress exposure. These results support the hypothesis that the metabolic consequences of chronic stress vary with stress intensity and/or frequency. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Subacute stress and chronic stress interact to decrease intestinal barrier function in rats.

    Science.gov (United States)

    Lauffer, Adriana; Vanuytsel, Tim; Vanormelingen, Christophe; Vanheel, Hanne; Salim Rasoel, Shadea; Tóth, Joran; Tack, Jan; Fornari, Fernando; Farré, Ricard

    2016-01-01

    Psychological stress increases intestinal permeability, potentially leading to low-grade inflammation and symptoms in functional gastrointestinal disorders. We assessed the effect of subacute, chronic and combined stress on intestinal barrier function and mast cell density. Male Wistar rats were allocated to four experimental groups (n = 8/group): 1/sham; 2/subacute stress (isolation and limited movement for 24 h); 3/chronic crowding stress for 14 days and 4/combined subacute and chronic stress. Jejunum and colon were collected to measure: transepithelial electrical resistance (TEER; a measure of epithelial barrier function); gene expression of tight junction molecules; mast cell density. Plasma corticosterone concentration was increased in all three stress conditions versus sham, with highest concentrations in the combined stress condition. TEER in the jejunum was decreased in all stress conditions, but was significantly lower in the combined stress condition than in the other groups. TEER in the jejunum correlated negatively with corticosterone concentration. Increased expression of claudin 1, 5 and 8, occludin and zonula occludens 1 mRNAs was detected after subacute stress in the jejunum. In contrast, colonic TEER was decreased only after combined stress, and the expression of tight junction molecules was unaltered. Increased mast cell density was observed in the chronic and combined stress condition in the colon only. In conclusion, our data show that chronic stress sensitizes the gastrointestinal tract to the effects of subacute stress on intestinal barrier function; different underlying cellular and molecular alterations are indicated in the small intestine versus the colon.

  15. Possible Biomarkers of Chronic Stress Induced Exhaustion - A Longitudinal Study.

    Science.gov (United States)

    Wallensten, Johanna; Åsberg, Marie; Nygren, Åke; Szulkin, Robert; Wallén, Håkan; Mobarrez, Fariborz; Nager, Anna

    2016-01-01

    Vascular endothelial growth factor (VEGF), epidermal growth factor (EGF) and monocyte chemotactic protein-1 (MCP-1) have previously been suggested to be potential biomarkers for chronic stress induced exhaustion. The knowledge about VEGF has increased during the last decades and supports the contention that VEGF plays an important role in stress and depression. There is scarce knowledge on the possible relationship of EGF and MCP-1 in chronic stress and depression. This study further examines the role of VEGF, EGF and MCP-1 in women with chronic stress induced exhaustion and healthy women during a follow-up period of two years. Blood samples were collected from 105 women with chronic stress induced exhaustion on at least 50% sick leave for at least three months, at inclusion (T0), after 12 months (T12) and after 24 months (T24). Blood samples were collected at inclusion (T0) in 116 physically and psychiatrically healthy women. The plasma levels of VEGF, EGF and MCP-1 were analyzed using Biochip Array Technology. Women with chronic stress induced exhaustion had significantly higher plasma levels of VEGF and EGF compared to healthy women at baseline, T12 and at T24. There was no significant difference in plasma levels of MCP-1. Plasma levels of VEGF and EGF decreased significantly in women with chronic stress induced exhaustion during the two years follow-up. The replicated findings of elevated levels of VEGF and EGF in women with chronic stress induced exhaustion and decreasing plasma levels of VEGF and EGF during the two years follow-up add important knowledge to the pathophysiology of chronic stress induced exhaustion.

  16. Chronic oxidative stress after irradiation: an unproven hypothesis

    OpenAIRE

    Cohen, Samuel R; Cohen, Eric P

    2012-01-01

    Injury and organ failure after irradiation of late-responding tissues is a substantial problem in radiation oncology and a major threat after accidental or belligerent exposures. The mechanisms of injury may include death of clonogens, vascular injury, activation of cytokine networks, and/or chronic oxidative stress. Knowledge of mechanisms may guide optimal use of mitigators. The hypothesis of chronic oxidative stress as a mechanism of late radiation injury has received much attention. We re...

  17. Chronic stress affects immunologic but not cardiovascular responsiveness to acute psychological stress in humans

    NARCIS (Netherlands)

    Benschop, R. J.; Brosschot, J. F.; Godaert, G. L.; de Smet, M. B.; Geenen, R.; Olff, M.; Heijnen, C. J.; Ballieux, R. E.

    1994-01-01

    This study deals with the effect of chronic stress on physiological responsiveness to an acute psychological stressor in male high school teachers. Chronic stress was operationalized as the self-reported number of everyday problems. Twenty-seven subjects reporting extremely low or high numbers of

  18. Proteomics of desiccation tolerance during development and germination of maize embryos.

    Science.gov (United States)

    Huang, Hui; Møller, Ian Max; Song, Song-Quan

    2012-02-02

    Maize seeds were used to identify the key embryo proteins involved in desiccation tolerance during development and germination. Immature maize embryos (28N) during development and mature embryos imbibed for 72 h (72HN) are desiccation sensitive. Mature maize embryos (52N) during development are desiccation tolerant. Thiobarbituric acid reactive substance and hydrogen peroxide contents decreased and increased with acquisition and loss of desiccation tolerance, respectively. A total of 111 protein spots changed significantly (1.5 fold increase/decrease) in desiccation-tolerant and -sensitive embryos before (28N, 52N and 72HN) and after (28D, 52D and 72HD) dehydration. Nine pre-dominantly proteins, 17.4 kDa Class I heat shock protein 3, late embryogenesis abundant protein EMB564, outer membrane protein, globulin 2, TPA:putative cystatin, NBS-LRR resistance-like protein RGC456, stress responsive protein, major allergen Bet v 1.01C and proteasome subunit alpha type 1, accumulated during embryo maturation, decreased during germination and increased in desiccation-tolerant embryos during desiccation. Two proteins, Rhd6-like 2 and low-molecular-weight heat shock protein precursor, showed the inverse pattern. We infer that these eleven proteins are involved in seed desiccation tolerance. We conclude that desiccation-tolerant embryos make more economical use of their resources to accumulate protective molecules and antioxidant systems to deal with maturation drying and desiccation treatment. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Endoplasmic reticulum stress implicated in chronic traumatic encephalopathy.

    Science.gov (United States)

    Lucke-Wold, Brandon P; Turner, Ryan C; Logsdon, Aric F; Nguyen, Linda; Bailes, Julian E; Lee, John M; Robson, Matthew J; Omalu, Bennet I; Huber, Jason D; Rosen, Charles L

    2016-03-01

    Chronic traumatic encephalopathy is a progressive neurodegenerative disease characterized by neurofibrillary tau tangles following repetitive neurotrauma. The underlying mechanism linking traumatic brain injury to chronic traumatic encephalopathy has not been elucidated. The authors investigate the role of endoplasmic reticulum stress as a link between acute neurotrauma and chronic neurodegeneration. The authors used pharmacological, biochemical, and behavioral tools to assess the role of endoplasmic reticulum stress in linking acute repetitive traumatic brain injury to the development of chronic neurodegeneration. Data from the authors' clinically relevant and validated rodent blast model were compared with those obtained from postmortem human chronic traumatic encephalopathy specimens from a National Football League player and World Wrestling Entertainment wrestler. The results demonstrated strong correlation of endoplasmic reticulum stress activation with subsequent tau hyperphosphorylation. Various endoplasmic reticulum stress markers were increased in human chronic traumatic encephalopathy specimens, and the endoplasmic reticulum stress response was associated with an increase in the tau kinase, glycogen synthase kinase-3β. Docosahexaenoic acid, an endoplasmic reticulum stress inhibitor, improved cognitive performance in the rat model 3 weeks after repetitive blast exposure. The data showed that docosahexaenoic acid administration substantially reduced tau hyperphosphorylation (t = 4.111, p < 0.05), improved cognition (t = 6.532, p < 0.001), and inhibited C/EBP homology protein activation (t = 5.631, p < 0.01). Additionally the data showed, for the first time, that endoplasmic reticulum stress is involved in the pathophysiology of chronic traumatic encephalopathy. Docosahexaenoic acid therefore warrants further investigation as a potential therapeutic agent for the prevention of chronic traumatic encephalopathy.

  20. Chronic stress promotes palatable feeding, which reduces signs of stress: feedforward and feedback effects of chronic stress.

    Science.gov (United States)

    Pecoraro, Norman; Reyes, Faith; Gomez, Francisca; Bhargava, Aditi; Dallman, Mary F

    2004-08-01

    We suggested a new model of the effects of glucocorticoids (GCs) exerted during chronic stress, in which GCs directly stimulate activities in the brain while indirectly inhibiting activity in the hypothalamo-pituitary-adrenal (HPA) axis through their metabolic shifts in energy stores in the periphery. This study is an initial test of our model. In a 2 x 2 design, we provided ad lib access to calorically dense lard and sucrose (comfort food) + chow or chow alone, and repeatedly restrained half of the rats in each group for 5 d (3 h/d). We measured caloric intake, body weight, caloric efficiency, ACTH, corticosterone (B), and testosterone during the period of restraint and leptin, insulin, and fat depot weights, as well as hypothalamic corticotropin-releasing factor mRNA at the end of the period. We hypothesized that chronically restrained rats would exhibit a relative increase in comfort food ingestion and that these rats would have reduced HPA responses to repeated restraint. Although total caloric intake was reduced in both groups of restrained rats, compared with controls, the proportion of comfort food ingested increased in the restrained rats compared with their nonrestrained controls. Moreover, caloric efficiency was rescued in the stressed, comfort food group. Furthermore, ACTH and B responses to the repeated restraint bouts were reduced in the rats with access to comfort food. Corticotropin-releasing factor mRNA was reduced in control rats eating comfort food compared with those eating chow, but there were no differences between the stressed groups. The results of this experiment tend to support our model of chronic effects of stress and GCs, showing a stressor-induced preference for comfort food, and a comfort-food reduction in activity of the HPA axis.

  1. Bile lipids in rats under chronic social stress

    Directory of Open Access Journals (Sweden)

    A. M. Liashevych

    2017-08-01

    Full Text Available Our experiments studied changes in lipid compound of bile of non-purebred male rats under the condition of social stress while the preparation “Korvitin” was used against the stress. Using the method of thin-layer chromatography, we determined the concentrations of phospholipids, cholesterol and its esters, free fatty acids and triglycerides in the animals’ bile, which was obtained through vivesection a day and a month after the rats were first subjected to chronic social stress (model of social defeat, and also in the bile of the animals which were treated intragastrically with “Korvitin” against the stress (1 mg/kg, 7 days. In the bile of the male rats which experienced chronic social stress the concentration of free cholesterol decreased and the content of its esters increased both immediately after the initiation of stress and after a month of exposure to stress. The concentration of free fatty acids in the bile decreased after modeling chronic social stress, but increased in liver secretion, taken a month after the animals had first experienced stress. In the bile of male rats immediately after the procedure of exposing the animals to stress, the content of phospholipids decreased. Using “Korvitin” during the modeling of social stress caused decrease in the content of phospholipids in the rats’ bile and caused significant increase in the concentration of free fatty acids, triglycerides and cholesterol esters in the liver secretion. The study found significant changes in the concentration of lipids in the bile and in their distribution in the organism of male rats under the conditions of experimentally induced chronic stress. The effect of stress on the bile of rats requires further study for determining its pathogenic role.

  2. Oxidative Stress among Ghanaian Patients presenting with Chronic ...

    African Journals Online (AJOL)

    Dyslipidaemia and lipid peroxidation are known risk factors for chronic kidney disease (CKD). This study assessed the lipid profile and oxidative stress/lipid peroxidation in CKD patient, using the oxidative stress marker, Malondialdehyde (MDA) and antioxidants; Vitamins A and C, Cata-lase and Uric Acid. The study ...

  3. Medication overuse, healthy lifestyle behaviour and stress in chronic headache

    DEFF Research Database (Denmark)

    Westergaard, Maria Lurenda; Glümer, Charlotte; Hansen, Ebba Holme

    2016-01-01

    AIM: This cross-sectional study investigated associations between chronic headache (CH) with and without medication overuse, healthy lifestyle behaviour, and stress. METHODS: Questionnaires were sent to 129,150 adults. Those with headache ≥15 days per month for three months were classified...... strong links between healthy lifestyle behaviour and stress in MOH. Stress reduction and promoting healthy behaviour are highly relevant in MOH management....

  4. Review of Desiccant Dehumidification Technology

    Energy Technology Data Exchange (ETDEWEB)

    Pesaran, A. A.

    1994-10-01

    This paper overviews applications of desiccant technology for dehumidifying commercial and institutional buildings. Because of various market, policy, and regulatory factors, this technology is especially attractive for dehumidification applications in the I990s.

  5. Acute Stress Decreases but Chronic Stress Increases Myocardial Sensitivity to Ischemic Injury in Rodents.

    Science.gov (United States)

    Eisenmann, Eric D; Rorabaugh, Boyd R; Zoladz, Phillip R

    2016-01-01

    Cardiovascular disease (CVD) is the largest cause of mortality worldwide, and stress is a significant contributor to the development of CVD. The relationship between acute and chronic stress and CVD is well evidenced. Acute stress can lead to arrhythmias and ischemic injury. However, recent evidence in rodent models suggests that acute stress can decrease sensitivity to myocardial ischemia-reperfusion injury (IRI). Conversely, chronic stress is arrhythmogenic and increases sensitivity to myocardial IRI. Few studies have examined the impact of validated animal models of stress-related psychological disorders on the ischemic heart. This review examines the work that has been completed using rat models to study the effects of stress on myocardial sensitivity to ischemic injury. Utilization of animal models of stress-related psychological disorders is critical in the prevention and treatment of cardiovascular disorders in patients experiencing stress-related psychiatric conditions.

  6. Acute Stress Decreases but Chronic Stress Increases Myocardial Sensitivity to Ischemic Injury in Rodents

    Science.gov (United States)

    Eisenmann, Eric D.; Rorabaugh, Boyd R.; Zoladz, Phillip R.

    2016-01-01

    Cardiovascular disease (CVD) is the largest cause of mortality worldwide, and stress is a significant contributor to the development of CVD. The relationship between acute and chronic stress and CVD is well evidenced. Acute stress can lead to arrhythmias and ischemic injury. However, recent evidence in rodent models suggests that acute stress can decrease sensitivity to myocardial ischemia–reperfusion injury (IRI). Conversely, chronic stress is arrhythmogenic and increases sensitivity to myocardial IRI. Few studies have examined the impact of validated animal models of stress-related psychological disorders on the ischemic heart. This review examines the work that has been completed using rat models to study the effects of stress on myocardial sensitivity to ischemic injury. Utilization of animal models of stress-related psychological disorders is critical in the prevention and treatment of cardiovascular disorders in patients experiencing stress-related psychiatric conditions. PMID:27199778

  7. Chronic Stress and Suicidal Thinking Among Medical Students

    Science.gov (United States)

    Rosiek, Anna; Rosiek-Kryszewska, Aleksandra; Leksowski, Łukasz; Leksowski, Krzysztof

    2016-01-01

    Introduction: The subject of chronic stress and ways of dealing with it are very broad. The aim of this study was to analyze stress and anxiety and their influence on suicidal thinking among medical students. Materials and Methods: The study was conducted in the years 2014 to 2015 in Poland, at the Medical University—Nicolaus Copernicus University, Collegium Medicum. The objective of this study was to assess chronic stress and suicidal thinking among students and how students cope with this huge problem. Descriptive statistics and chi-square analyses were conducted to detect differences. Results: Analyses showed that students’ life is full of stressors. Students toward the end of their education cope better with stress than students starting their university studies. Chronic stress has a strong impact on mental health and suicidal thinking among students. Conclusions: The results of the study confirmed that chronic stress and anxiety have a negative influence on mental health and also confirm a relation to suicidal thinking in medical students. Students cope with stress by listening to music, talking to relatives or people close to them, resting or engaging in sports, with cycling, running and swimming being the most common methods used to affect suicidal thinking. PMID:26891311

  8. Protracted effects of chronic stress on serotonin-dependent thermoregulation.

    Science.gov (United States)

    Natarajan, Reka; Northrop, Nicole A; Yamamoto, Bryan K

    2015-01-01

    Chronic stress is known to affect serotonin (5HT) neurotransmission in the brain and to alter body temperature. The body temperature is controlled in part, by the medial preoptic area (mPOA) of the hypothalamus. To investigate the effect of chronic stress on 5HT and how it affects body temperature regulation, we examined whether exposure to a chronic unpredictable stress (CUS) paradigm produces long-term alterations in thermoregulatory function of the mPOA through decreased 5HT neurotransmission. Adult male Sprague-Dawley rats underwent 21 d of CUS. Four days after the last stress exposure, basal body temperature in the home cage and body temperature in a cold room maintained at 10 °C were recorded. The CUS rats had significantly higher subcutaneous basal body temperature at 13:00 h compared to unstressed (NoStress) rats. Whereas the NoStress rats were able to significantly elevate body temperature from basal levels at 30 and 60 min of exposure to the cold room, the CUS rats showed a hypothermic response to the cold. Treatment during CUS with metyrapone, a corticosterone synthesis inhibitor, blocked stress-induced decrease in body temperature in response to the cold challenge. CUS also decreased 5HT transporter protein immunoreactivity in the mPOA and 5HT2A/C agonist injection into the mPOA after CUS exposure caused stressed rats to exhibit a sensitized hyperthermic response to cold. These results indicate that the CUS induced changes to the 5HTergic system alter mPOA function in thermoregulation. These findings help us to explain the mechanisms underlying chronic stress-induced disorders such as chronic fatigue syndrome wherein long lasting thermoregulatory deficits are observed.

  9. Protracted effects of chronic stress on serotonin dependent thermoregulation

    Science.gov (United States)

    Natarajan, Reka; Northrop, Nicole A.; Yamamoto, Bryan K.

    2016-01-01

    Chronic stress is known to affect serotonin (5HT) neurotransmission in the brain and to alter body temperature. Body temperature is controlled in part, by the medial preoptic area of the hypothalamus (mPOA). To investigate the effect of chronic stress on 5HT and how it affects body temperature regulation, we examined whether exposure to a chronic unpredictable stress paradigm (CUS) produces long-term alterations in thermoregulatory function of the mPOA through decreased 5HT neurotransmission. Adult male Sprague-Dawley rats underwent 21 days of CUS. Four days after last stress exposure, basal body temperature in the home cage and body temperature in a cold room maintained at 10°C were recorded. CUS rats had significantly higher subcutaneous basal body temperature at 13:00 h compared to unstressed (NoStress) rats. Whereas the NoStress rats were able to significantly elevate body temperature from basal levels at 30 and 60 min of exposure to the cold room, the CUS rats showed a hypothermic response to the cold. Treatment during CUS with metyrapone, a corticosterone synthesis inhibitor, blocked stress-induced decrease in body temperature in response to the cold challenge. CUS also decreased 5HT transporter protein immunoreactivity in the mPOA and 5HT2A/C agonist injection into the mPOA after CUS exposure caused stressed rats to exhibit a sensitized hyperthermic response to cold. These results indicate that CUS induced changes to the 5HTergic system alters mPOA function in thermoregulation. These findings help explain mechanisms underlying chronic stress induced disorders such as chronic fatigue syndrome wherein long lasting thermoregulatory deficits are observed. PMID:26414686

  10. Stress-Induced Chronic Visceral Pain of Gastrointestinal Origin

    Science.gov (United States)

    Greenwood-Van Meerveld, Beverley; Johnson, Anthony C.

    2017-01-01

    Visceral pain is generally poorly localized and characterized by hypersensitivity to a stimulus such as organ distension. In concert with chronic visceral pain, there is a high comorbidity with stress-related psychiatric disorders including anxiety and depression. The mechanisms linking visceral pain with these overlapping comorbidities remain to be elucidated. Evidence suggests that long term stress facilitates pain perception and sensitizes pain pathways, leading to a feed-forward cycle promoting chronic visceral pain disorders such as irritable bowel syndrome (IBS). Early life stress (ELS) is a risk-factor for the development of IBS, however the mechanisms responsible for the persistent effects of ELS on visceral perception in adulthood remain incompletely understood. In rodent models, stress in adult animals induced by restraint and water avoidance has been employed to investigate the mechanisms of stress-induce pain. ELS models such as maternal separation, limited nesting, or odor-shock conditioning, which attempt to model early childhood experiences such as neglect, poverty, or an abusive caregiver, can produce chronic, sexually dimorphic increases in visceral sensitivity in adulthood. Chronic visceral pain is a classic example of gene × environment interaction which results from maladaptive changes in neuronal circuitry leading to neuroplasticity and aberrant neuronal activity-induced signaling. One potential mechanism underlying the persistent effects of stress on visceral sensitivity could be epigenetic modulation of gene expression. While there are relatively few studies examining epigenetically mediated mechanisms involved in visceral nociception, stress-induced visceral pain has been linked to alterations in DNA methylation and histone acetylation patterns within the brain, leading to increased expression of pro-nociceptive neurotransmitters. This review will discuss the potential neuronal pathways and mechanisms responsible for stress

  11. Nonlinear associations between chronic stress and cardiovascular reactivity and recovery.

    Science.gov (United States)

    Chatkoff, David K; Maier, Karl J; Klein, Christian

    2010-08-01

    A mixed literature on the influence of chronic and acute stress on cardiovascular reactivity (CVR) and recovery suggests a need for improved modeling of these associations. We examined these associations using both linear and nonlinear (quadratic) models. Data were collected on 129 healthy adults [59% female, ages 18-29 years]. Participants completed the Perceived Stress Scale (PSS) after engaging in a mental arithmetic and a stress recall task. Heart rate (HR), systolic and diastolic blood pressure (SBP, DBP) were measured during rest, task, and recovery periods. Hierarchical ordinary least squares regression was used to examine the association of chronic stress to CVR and recovery with initial cardiovascular values and body mass index entered first as covariates. Hierarchical linear modeling (HLM) was also used for recovery. For reactivity, a quadratic relationship between PSS scores and DBP was observed in females such that those scoring at moderate levels of stress displayed lesser reactivity than those scoring either low or high. For recovery, a quadratic model was supported for SBP among females, with moderate levels of stress associated with greater recovery relative to either low or high levels. For females the quadratic model was also supported for SBP and DBP when examined using HLM. Quadratic modeling may better represent current theories of how chronic stress influences CVR and recovery. Our findings further suggest that these associations may be differentially evident by gender, perhaps due to gender differences in reported stress levels or gender-related task relevance. Copyright 2010 Elsevier B.V. All rights reserved.

  12. Chronic unpredictable stress during adolescence causes long-term anxiety.

    Science.gov (United States)

    Chaby, L E; Cavigelli, S A; Hirrlinger, A M; Caruso, M J; Braithwaite, V A

    2015-02-01

    Exposure to stress during adolescence can cause long-term changes in behavior and cognition. Anxiety diagnoses rise during adolescence and are increased by adverse experiences. Currently, it is unknown how long stress during adolescence alters anxiety in adulthood. We found that rats exposed to chronic unpredictable stress during adolescence expressed altered behavior 6.5 months later; showing increased anxiety in a feeding test in a novel environment. Although behavioral changes indicative of anxiety were detected in late adulthood, the basal levels of fecal corticoid metabolites in prior-stressed rats did not differ from unstressed, control rats. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Desiccant contamination research: Report on the desiccant contamination test facility

    Energy Technology Data Exchange (ETDEWEB)

    Pesaran, A.A.; Bingham, C.E.

    1991-07-01

    The activity in the cooling systems research involves research on high performance dehumidifiers and chillers that can operate efficiently with the variable thermal outputs and delivery temperatures associated with solar collectors. It also includes work on advanced passive cooling techniques. This report describes the work conducted to improve the durability of solid desiccant dehumidifiers by investigating the causes of degradation of desiccant materials from airborne contaminants and thermal cycling. The performance of a dehumidifier strongly depends on the physical properties and durability of the desiccant material. To make durable and reliable dehumidifiers, an understanding is needed of how and to what degree the performance of a dehumidifier is affected by desiccant degradation. This report, an account of work under Cooling Systems Research, documents the efforts to design and fabricate a test facility to investigate desiccant contamination based on industry and academia recommendations. It also discusses the experimental techniques needed for obtaining high-quality data and presents plans for next year. Researchers of the Mechanical and Industrial Technology Division performed this work at the Solar Energy Research Institute in FY 1988 for DOE's Office of Solar Heat Technologies. 7 refs., 19 figs., 1 tab.

  14. Chronic social stress leads to altered sleep homeostasis in mice.

    Science.gov (United States)

    Olini, Nadja; Rothfuchs, Iru; Azzinnari, Damiano; Pryce, Christopher R; Kurth, Salome; Huber, Reto

    2017-06-01

    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.

  15. Interaction of Metabolic Stress with Chronic Mild Stress in Altering Brain Cytokines and Sucrose Preference

    OpenAIRE

    Remus, Jennifer L.; Stewart, Luke T.; Camp, Robert M.; Novak, Colleen M.; Johnson, John D.

    2015-01-01

    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...

  16. Characteristics of Disaster Associated with Chronic Stress.

    Science.gov (United States)

    Fleming, India; Baum, Andrew

    Historically, most investigations of the social and psychological effects of disaster have focused on describing the impact of single traumatic events rather than on developing an understanding of how disasters or particular characteristics of disasters affect various groups of victims. This study investigated the hypothesis that stress caused by…

  17. Chronic restraint stress upregulates erythropoiesis through glucocorticoid stimulation.

    Directory of Open Access Journals (Sweden)

    Jeffrey L Voorhees

    Full Text Available In response to elevated glucocorticoid levels, erythroid progenitors rapidly expand to produce large numbers of young erythrocytes. Previous work demonstrates hematopoietic changes in rodents exposed to various physical and psychological stressors, however, the effects of chronic psychological stress on erythropoiesis has not be delineated. We employed laboratory, clinical and genomic analyses of a murine model of chronic restraint stress (RST to examine the influence of psychological stress on erythropoiesis. Mice exposed to RST demonstrated markers of early erythroid expansion involving the glucocorticoid receptor. In addition, these RST-exposed mice had increased numbers of circulating reticulocytes and increased erythropoiesis in primary and secondary erythroid tissues. Mice also showed increases in erythroid progenitor populations and elevated expression of the erythroid transcription factor KLF1 in these cells. Together this work reports some of the first evidence of psychological stress affecting erythroid homeostasis through glucocorticoid stimulation.

  18. Chronic stress does not impair liver regeneration in rats

    DEFF Research Database (Denmark)

    Andersen, Kasper J; Knudsen, Anders Riegels; Wiborg, Ove

    2015-01-01

    a 70 % partial hepatectomy (PHx). The animals were evaluated on postoperative day 2 or 4. Blood samples were collected to examine circulating markers of inflammation and liver cell damage. Additionally, liver tissues were sampled to evaluate liver weight and regeneration rate. RESULTS: None......BACKGROUND: Although wound healing is a simple regenerative process that is critical after surgery, it has been shown to be impaired under psychological stress. The liver has a unique capacity to regenerate through highly complex mechanisms. The aim of this study was to investigate the effects...... of chronic stress, which may induce a depression-like state, on the complex process of liver regeneration in rats. METHODS: Twenty rats were included in this study. The animals received either a standard housing protocol or were subjected to a Chronic Mild Stress (CMS) stress paradigm. All rats underwent...

  19. Influence of stress associated with chronic alcohol exposure on drinking.

    Science.gov (United States)

    Becker, Howard C

    2017-08-01

    Stress is commonly regarded as an important trigger for relapse and a significant factor that promotes increased motivation to drink in some individuals. However, the relationship between stress and alcohol is complex, likely changing in form during the transition from early moderated alcohol use to more heavy uncontrolled alcohol intake. A growing body of evidence indicates that prolonged excessive alcohol consumption serves as a potent stressor, producing persistent dysregulation of brain reward and stress systems beyond normal homeostatic limits. This progressive dysfunctional (allostatic) state is characterized by changes in neuroendocrine and brain stress pathways that underlie expression of withdrawal symptoms that reflect a negative affective state (dysphoria, anxiety), as well as increased motivation to self-administer alcohol. This review highlights literature supportive of this theoretical framework for alcohol addiction. In particular, evidence for stress-related neural, physiological, and behavioral changes associated with chronic alcohol exposure and withdrawal experience is presented. Additionally, this review focuses on the effects of chronic alcohol-induced changes in several pro-stress neuropeptides (corticotropin-releasing factor, dynorphin) and anti-stress neuropeptide systems (nocicepton, neuropeptide Y, oxytocin) in contributing to the stress, negative emotional, and motivational consequences of chronic alcohol exposure. Studies involving use of animal models have significantly increased our understanding of the dynamic stress-related physiological mechanisms and psychological underpinnings of alcohol addiction. This, in turn, is crucial for developing new and more effective therapeutics for treating excessive, harmful drinking, particularly stress-enhanced alcohol consumption. This article is part of the Special Issue entitled "Alcoholism". Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Chronic stress and pituitary-adrenal function in female pigs

    OpenAIRE

    Janssens, C.J.J.G.

    1994-01-01

    Introduction

    The main purpose of the studies described in this thesis was to gain more insight in the regulation of the hypothalamic-pituitary-adrenocorticaI (HPA) system and the mechanisms underlying adaptation to chronic stress in female pigs. The function of the HPA axis, which coordinates multiple neuroendocrine and metabolic responses to stressors, has been subject of extensive basic and clinical research. HPA-activation by stressful stimuli results in an increase in circulating ...

  1. [Neurophysiologic mechanisms of arterial hypertension under experimental chronic emotional stress].

    Science.gov (United States)

    Baumann, H; Martin, G; Urmantscheeva, T G; Degen, G; Wolter, F; Chasabova, W A; Gurk, C; Hinays, I; Läuter, J

    1976-01-01

    Neurophysiological studies were conducted with subhuman primates (macaca mulatta) in order to obtain an estimate of central nervous effects of socio-emotional stress. This was combined with continuously aggravated conditioning procedures in view of the possible significance of chronic environmental stress escalation for etiology and pathogenesis of an arterial hypertension model. Our conclusions are based on evoked potentials (EP) as integrative characteristics of cerebral information processing. The EPs were recorded by means of electrodes chronically implanted in brain structures of emotional and cardio-vascular relevance. Multivariate mathematico-statistical analyses of average EPs (AEP) provide an objective measure of stress sensibility of the individual, particularly of the effects of acute and chronic environmental stress factors upon the functional organization of the CNS. By means of a quantitative approach to AEP we were able to demonstrate a disjunction between distinct limbic and hypothalamic structures starting under stress conditions of subchronic character. We assume that the constancy of functionally antagonistic hyperactive excitation foci at diencephalic and supradiencephalic levels and their specific interaction with the equally stress related neocortical functional insufficiency constitutes a decisive pathogenetic central mechanism of neurotic behaviour. Long-term changes of amplification of external and internal afferences could be demonstrated on the basis of hypo- and hyperreactive neuroelectric functional patterns. These processes cause cerebro-visceral regulatory diseases as, e. g., a primary arterial hypertension by restriction of neocortical control and the corresponding efferent reactions for re-establishment of the dynamic homeostasis.

  2. Chronic Stress Facilitates the Development of Deep Venous Thrombosis

    Directory of Open Access Journals (Sweden)

    Tao Dong

    2015-01-01

    Full Text Available The increasing pressure of modern social life intensifies the impact of stress on the development of cardiovascular diseases, which include deep venous thrombosis (DVT. Renal sympathetic denervation has been applied as one of the clinical approaches for the treatment of drug-resistant hypertension. In addition, the close relationship between oxidative stress and cardiovascular diseases has been well documented. The present study is designed to explore the mechanism by which the renal sympathetic nerve system and the oxidative stress affect the blood coagulation system in the development of DVT. Chronic foot shock model in rats was applied to mimic a state of physiological stress similar to humans. Our results showed that chronic foot shock procedure could promote DVT which may be through the activation of platelets aggregation. The aggravation of DVT and activation of platelets were alleviated by renal sympathetic denervation or antioxidant (Tempol treatment. Concurrently, the denervation treatment could also reduce the levels of circulating oxidation factors in rats. These results demonstrate that both the renal sympathetic nerve system and the oxidative stress contribute to the development of DVT in response to chronic stress, which may provide novel strategy for treatment of clinic DVT patients.

  3. Dyshomeostasis, obesity, addiction and chronic stress

    OpenAIRE

    Marks, David F

    2016-01-01

    When eating control is overridden by hedonic reward, a condition of obesity dyshomeostasis occurs. Appetitive hedonic reward is a natural response to an obesogenic environment containing endemic stress and easily accessible and palatable high-energy foods and beverages. Obesity dyshomeostasis is mediated by the prefrontal cortex, amygdala and hypothalamic?pituitary?adrenal axis. The ghrelin axis provides the perfect signalling system for feeding dyshomeostasis, affect control and hedonic rewa...

  4. Sex differences in chronic stress effects on cognition in rodents.

    Science.gov (United States)

    Luine, Victoria; Gomez, Juan; Beck, Kevin; Bowman, Rachel

    2017-01-01

    Chronic stress causes deleterious changes in physiological function in systems ranging from neural cells in culture to laboratory rodents, sub-human primates and humans. It is notable, however, that the vast majority of research in this area has been conducted in males. In this review, we provide information about chronic stress effects on cognition in female rodents and contrast it with responses in male rodents. In general, females show cognitive resilience to chronic stressors which impair male cognitive function using spatial tasks including the radial arm maze, radial arm water maze, Morris water maze, Y-maze and object placement. Moreover, stress often enhances female performance in some of these cognitive tasks. Memory in females is not affected by stress in non-spatial memory tasks like recognition memory and temporal order recognition memory while males show impaired memory following stress. We discuss possible bases for these sex-dependent differences including the use of different strategies by the sexes to solve cognitive tasks. Whether the sex differences result from changes in non-mnemonic factors is also considered. Sex-dependent differences in alcohol and drug influences on stress responses are also described. Finally, the role of neurally derived estradiol in driving sex differences and providing resilience to stress in females is shown. The importance of determining the nature and extent of sex differences in stress responses is that such differences may provide vital information for understanding why some stress related diseases have different incidence rates between the sexes and for developing novel therapeutic treatments. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Protective effects of carnosol against oxidative stress induced brain damage by chronic stress in rats.

    Science.gov (United States)

    Samarghandian, Saeed; Azimi-Nezhad, Mohsen; Borji, Abasalt; Samini, Mohammad; Farkhondeh, Tahereh

    2017-05-04

    Oxidative stress through chronic stress destroys the brain function. There are many documents have shown that carnosol may have a therapeutic effect versus free radical induced diseases. The current research focused the protective effect of carnosol against the brain injury induced by the restraint stress. The restraint stress induced by keeping animals in restrainers for 21 consecutive days. Thereafter, the rats were injected carnosol or vehicle for 21 consecutive days. At the end of experiment, all the rats were subjected to his open field test and forced swimming test. Afterwards, the rats were sacrificed for measuring their oxidative stress parameters. To measure the modifications in the biochemical aspects after the experiment, the activities of malondialdehyde (MDA), reduced glutathione (GSH), as well as superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR) and catalase (CAT) were evaluated in the whole brain. Our data showed that the animals received chronic stress had a raised immobility time versus the non-stressed animals (p < 0.01). Furthermore, chronic stress diminished the number of crossing in the animals that were subjected to the chronic stress versus the non-stressed rats (p < 0.01). Carnosol ameliorated this alteration versus the non-treated rats (p < 0.05). In the vehicle treated rats that submitted to the stress, the level of MDA levels was significantly increased (P < 0.001), and the levels of GSH and antioxidant enzymes were significantly decreased versus the non-stressed animals (P < 0.001). Carnosol treatment reduced the modifications in the stressed animals as compared with the control groups (P < 0.001). All of these carnosol effects were nearly similar to those observed with fluoxetine. The current research shows that the protective effects of carnosol may be accompanied with enhanced antioxidant defenses and decreased oxidative injury.

  6. Low maternal care exacerbates adult stress susceptibility in the chronic mild stress rat model of depression

    DEFF Research Database (Denmark)

    Henningsen, Kim; Dyrvig, Mads; Bouzinova, Elena V

    2012-01-01

    In the present study we report the finding that the quality of maternal care, in early life, increased the susceptibility to stress exposure in adulthood, when rats were exposed to the chronic mild stress paradigm. Our results indicate that high, as opposed to low maternal care, predisposed rats ...

  7. Chronic stress and pituitary-adrenal function in female pigs

    NARCIS (Netherlands)

    Janssens, C.J.J.G.

    1994-01-01

    Introduction

    The main purpose of the studies described in this thesis was to gain more insight in the regulation of the hypothalamic-pituitary-adrenocorticaI (HPA) system and the mechanisms underlying adaptation to chronic stress in female pigs. The function of the HPA axis, which

  8. Responses of the Lichen Photobiont Trebouxia erici to Desiccation and Rehydration (II) Proteomics

    Science.gov (United States)

    Lichen desiccation tolerance is associated with cellular protection mechanisms directed against the oxidative stress produced during dehydration and/or rehydration, however, these mechanisms are not well understood. In other poikilohydric organisms, changes in the synthesis of proteins have bee...

  9. VR Mobile Solutions For Chronic Stress Reduction in Young Adults.

    Science.gov (United States)

    Gao, Kenneth; Boyd, Chelsie; Wiederhold, Mark D; Wiederhold, Brenda K

    2014-01-01

    Chronic stress in young adults has become a growing problem within recent decades and many are unable to find cost-effective and accessible treatment for psychological stress in their daily lives. We analyze the market of using a mobile application, Positive Technology, as a solution. Eleven participants, aged between 18 and 24, participated in the exercise. Self-reported stress reduction was measured via an online marketing survey, while physiological measurements were monitored via peripheral devices. Secondary goals assessed the app's ease-of-use, accessibility, and cost. Results indicate that participants enjoyed the availability of the mobile solution and found the app to be fun and easy to learn. Stress levels were reduced in 73% of the participants, with higher effects in females and in participants aged 18-24. We conclude that the mobile platform is an effective means of delivering psychological stress reduction, and could provide an accessible, cost-effective solution.

  10. [Chronic stress and epigenetics. Relation between academic sciences and theology].

    Science.gov (United States)

    Simon, Kornél

    2012-04-08

    The author gives a short account on the principles of Selye's stress theory, and discusses similarities and dissimilarities of acute and chronic stress. Both the external, and the internal environment, as well as the psycho-mental status are involved in the notion of the environment. Basic principles of epigenetics are reviewed: interaction between environment and genes, neuroendocrine and enzymatic mechanisms involved in silencing and activation of genes, notions of phenotypic plasticity, and epigenetic reprogramming are discussed. Epigenetic mechanisms of interrelation between pathological clinical states (diseases) and the characteristic phenotypes, causative role of psycho-mental status in evoking pathological somatic alterations, and the potential therapeutic consequences are briefly discussed. The etiological role of chronic, civilization stress in producing the worldwide increment of cardiovascular morbidity is cited, argumentation and criticism of the current therapeutical practice is discussed. The author concludes that recent advances in epigenetic knowledge seem to solve the controversy between the academic and theological sciences.

  11. Adaptogenic potential of Oxitard in experimental chronic stress and chronic unpredictable stress induced dysfunctional homeostasis in rodents.

    Science.gov (United States)

    Kishor, Brajnandan; Rai, Pooja; Bharatia, Rakesh; Kumar, Sanjay; Gupta, Sujeet Kumar; Sinha, Anshuman

    Oxitard, a polyherbal formulation comprising the extracts of Withania somnifera, Mangifera indica, Glycyrrhiza glabra, Daucus carota, Vitis vinifera, powders of Syzygium aromaticum, Yashada bhasma and Emblica officinalis; and oils of Triticum sativum. Current study deals with the assessment of Oxitard (a marketed polyherbal formulation) for its adaptogenic potential in chronic unpredictable stress (CUS) and chronic stress (CS) induced dysfunctional homeostasis in rodents. Animals were immobilized for 2 h every day for ten days to induce CS. In order to induce CUS, animals were employed in a battery of stressors of variable value and duration for ten days. Following administration of Oxitard, stress was induced in the animals. Stress-induced efficient changes were evaluated by assessing organ (adrenal gland) weights, ulcer index, hematological parameters and biochemical levels of reduced glutathione (GSH), thiobarbituric acid reactive substances (TBARS) and catalase (CAT). CS and CUS significantly modified the oxidative stress parameters (increased MDA and decreased GSH). Furthermore, CS and CUS lead to weight reduction, adrenal hypertrophy and gastric ulceration. Pre-treatment with Oxitard (200 and 400 mg/kg, p.o.) significantly modified CS and CUS induced hematological changes, oxidative stress parameters and pathological effects. In conclusion, Oxitard-intervened antioxidant actions are accountable for its adaptogenic effects in stress-induced dysfunctional homeostasis. Copyright © 2017 Transdisciplinary University, Bangalore and World Ayurveda Foundation. Published by Elsevier B.V. All rights reserved.

  12. The study of desiccation-tolerance in drying leaves of the desiccation-tolerant grass Sporobolus elongatus and the desiccation-sensitive grass Sporobolus pyramidalis.

    Science.gov (United States)

    Ghasempour, Hamid Reza; Kianian, Jahanbakheshe

    2007-03-01

    Hydrated leaves of the resurrection grass Sporobolus elongatus are not desiccation tolerant (DT), but moderate to severe drought stress can induce their DT with the leaves remain attach to drying intact plants. In vivo protein synthesis was studied with SDS-page of extracts of leaves of intact drying plants of S. elongatus (a desiccation-Tolerant grass (DT)) and S. pyramidalis (a desiccation-sensitive species (DS)). Free proline increased in drying leaves. Soluble sugar contents also increased with drying but were less than fully hydrated leaves at 8% RWC. Total protein also showed an increase with an exception at 8% RWC which showed a decrease. SDS-page of extracts of drying leaves of both DT and DS plants were studied as relative water contents (RWC) decreased. In first phase, DT species at 58% RWC (80-51% RWC range), two proteins increased in contents. In the second phase, at 8% (35-4% RWC range) two new bands increased and two bands decreased. In leaves of DS species some bands decreased as drying progressed. Also, as drying advanced free proline increased in DT species. Total protein increased as drying increased but at 8% RWC decreased. All data of results are consistent with current views about studied factors and their roles during drying and induction of desiccation tolerance in DT plants.

  13. Stiffness of desiccating insect wings

    Energy Technology Data Exchange (ETDEWEB)

    Mengesha, T E; Vallance, R R [Department of Mechanical Engineering, The George Washington University, 738 Phillips Hall, 801 22nd St NW, Washington, DC 20052 (United States); Mittal, R, E-mail: vallance@gwu.edu [Department of Mechanical Engineering, Johns Hopkins University, 126 Latrobe Hall, 3400 N Charles Street, Baltimore, MD 21218 (United States)

    2011-03-15

    The stiffness of insect wings is typically determined through experimental measurements. Such experiments are performed on wings removed from insects. However, the wings are subject to desiccation which typically leads to an increase in their stiffness. Although this effect of desiccation is well known, a comprehensive study of the rate of change in stiffness of desiccating insect wings would be a significant aid in planning experiments as well as interpreting data from such experiments. This communication presents a comprehensive experimental analysis of the change in mass and stiffness of gradually desiccating forewings of Painted Lady butterflies (Vanessa cardui). Mass and stiffness of the forewings of five butterflies were simultaneously measured every 10 min over a 24 h period. The averaged results show that wing mass declined exponentially by 21.1% over this time period with a time constant of 9.8 h, while wing stiffness increased linearly by 46.2% at a rate of 23.4 {mu}N mm{sup -1} h{sup -1}. For the forewings of a single butterfly, the experiment was performed over a period of 1 week, and the results show that wing mass declined exponentially by 52.2% with a time constant of 30.2 h until it reached a steady-state level of 2.00 mg, while wing stiffness increased exponentially by 90.7% until it reached a steady-state level of 1.70 mN mm{sup -1}. (communication)

  14. Slow desiccation improves dehydration tolerance and accumulation of compatible osmolytes in earthworm cocoons (Dendrobaena octaedra Savigny).

    Science.gov (United States)

    Petersen, Christina R; Holmstrup, Martin; Malmendal, Anders; Bayley, Mark; Overgaard, Johannes

    2008-06-01

    The earthworm, Dendrobaena octaedra, is a common species in temperate and subarctic regions of the northern hemisphere. The egg capsules ('cocoons') of D. octaedra are deposited in the upper soil layers where they may be exposed to desiccation. Many previous studies on desiccation tolerance in soil invertebrates have examined acute exposure to harsh desiccating conditions, however, these animals are often more likely to be exposed to a gradually increasing drought stress. In the present study we slowly desiccated D. octaedra cocoons to simulate ecologically realistic drought conditions and the results clearly demonstrate that gradually dehydrated cocoons show an increased tolerance of extreme drought compared with acutely dehydrated cocoons. NMR spectroscopic analysis of compatible osmolytes revealed the presence of sorbitol, glucose, betaine, alanine and mannitol in dehydrated embryos. The superior drought survival of gradually desiccated embryos could partly be attributed to a higher accumulation of osmolytes (especially sorbitol). Thus, gradually and acutely desiccated embryos accumulated approximately 2 mol l(-1) and 1 mol l(-1) total osmolytes, respectively. However, in addition to osmolyte accumulation, the gradually desiccated cocoons also tolerated a higher degree of water loss, demonstrating that gradually dehydrated D. octaedra cocoons are able to survive loss of approximately 95% of the original water content. Although D. octaedra embryos can probably not be categorized as a truly anhydrobiotic organism we propose that they belong in a transition zone between the desiccation sensitive and the truly anhydrobiotic organisms. Clearly, these earthworm embryos share many physiological traits with anhydrobiotic organisms.

  15. Oxidative stress and chronic renal failure: markers and management.

    Science.gov (United States)

    Massy, Ziad A; Nguyen-Khoa, Thao

    2002-01-01

    New reliable oxidative stress markers are present in chronic renal failure (CRF) patients, indicating that CRF is a pro-oxidant state. However, the pathogenesis of oxidative stress in CRF patients remains poorly defined. Moreover, the limited data available provide no clear-cut evidence in favor of the clinical benefit of antioxidant manoeuvres aimed at reducing cardiovascular disease in CRF patients or in the general population as well. Therefore, no practical recommendations can be given at this stage, and further studies are clearly needed.

  16. Chronic subordinate colony housing (CSC as a model of chronic psychosocial stress in male rats.

    Directory of Open Access Journals (Sweden)

    Kewir D Nyuyki

    Full Text Available Chronic subordinate colony housing (CSC is an adequate and reliable mouse model of chronic psychosocial stress, resulting in reduced body weight gain, reduced thymus and increased adrenal weight, long-lasting anxiety-like behaviour, and spontaneous colitis. Furthermore, CSC mice show increased corticotrophin (ACTH responsiveness to acute heterotypic stressors, suggesting a general mechanism which allows a chronically-stressed organism to adequately respond to a novel threat. Therefore, the aim of the present study was to extend the CSC model to another rodent species, namely male Wistar rats, and to characterize relevant physiological, immunological, and behavioural consequences; placing particular emphasis on changes in hypothalamo-pituitary-adrenal (HPA axis responsiveness to an acute heterotypic stressor. In line with previous mouse data, exposure of Wistar rats to 19 days of CSC resulted in a decrease in body weight gain and absolute thymus mass, mild colonic barrier defects and intestinal immune activation. Moreover, no changes in stress-coping behaviour or social preference were seen; again in agreement with the mouse paradigm. Most importantly, CSC rats showed an increased plasma corticosterone response to an acute heterotypic stressor (open arm, 5 min despite displaying similar basal levels and similar basal and stressor-induced plasma ACTH levels. In contrast to CSC mice, anxiety-related behaviour and absolute, as well as relative adrenal weights remained unchanged in CSC rats. In summary, the CSC paradigm could be established as an adequate model of chronic psychosocial stress in male rats. Our data further support the initial hypothesis that adrenal hyper-responsiveness to ACTH during acute heterotypic stressors represents a general adaptation, which enables a chronically-stressed organism to adequately respond to novel challenges.

  17. Chronic psychological stress induces vascular inflammation in rabbits.

    Science.gov (United States)

    Lu, Xiao Ting; Liu, Yun Fang; Zhao, Li; Li, Wen Jing; Yang, Rui Xue; Yan, Fang Fang; Zhao, Yu Xia; Jiang, Fan

    2013-01-01

    Psychological stress is associated with a systemic inflammatory response. It is unclear, however, whether psychological stress contributes to vascular inflammation. Here, we examined the effects of unpredictable chronic mild stress (UCMS) on vascular inflammation in rabbits. One hundred rabbits were randomly divided into control and stress groups. UCMS was induced by a set of defined adverse conditions applied in a shuffled order for 4, 8, 12, or 16 weeks, and rabbits were killed 24 h after the end of the UCMS protocol. Expression of different inflammatory molecules was analyzed by real-time polymerase chain reaction, immunohistochemistry, or enzyme-linked immunosorbent assay. UCMS resulted in depression-like behaviors, decreased body weight gain, and hypertension with no significant effects on serum lipids. Aortic mRNA and protein expression for tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), monocyte chemoattractant protein-1 (MCP-1), macrophage migration inhibitory factor, and expression of intercellular adhesion molecule-1 (ICAM-1) protein were increased. UCMS increased circulating concentrations of corticosterone, TNF-α, and CRP throughout. Moreover, stress downregulated the expression of endothelial nitric oxide synthase. At 16 weeks of UCMS, macrophage infiltration and lipid accumulation in the subendothelial space were detected in the aorta. In cultured murine vascular smooth muscle cells, treatment with serum from stressed rabbits significantly increased phosphorylation of p38 and c-Jun N-terminal kinase (JNK), and upregulated expression of MCP-1 and ICAM-1 mRNAs, in which the effect was blunted by a TNF-α neutralizing antibody or p38 and JNK inhibitors. Our results indicate that chronic psychological stress induces vascular inflammation via TNF-α and p38/JNK pathways, which may contribute to the development of atherosclerosis.

  18. Involvement of new oxidative stress markers in chronic spontaneous urticaria

    Directory of Open Access Journals (Sweden)

    Eustachio Nettis

    2017-10-01

    Full Text Available Introduction : Oxidative stress is a result of an imbalance between endogenous production of free reactive oxygen species and reduced effectiveness of antioxidant defence mechanisms. Advanced glycation end products (AGEs and advanced oxidation protein products (AOPPs are compounds formed by transformation of macromolecules, including proteins which can serve as markers of oxidative stress and inflammation in several diseases. Aim : To investigate the role of AGEs and AOPPs as new markers of oxidative stress and inflammation in patients with chronic spontaneous urticaria (CSU. Material and methods : Advanced glycation end products and AOPP levels were determined in the sera of 85 patients with CSU and 64 healthy controls, using spectrofluorimetry and spectrophotometry, respectively. Results : Advanced oxidation protein products levels in patients were statistically higher than those in controls. These levels were not affected by the presence of positive autologous serum test results or autologous plasma test results. No statistically significant differences were found between AGE levels in patients and controls. Conclusions : Formation of AGEs and AOPPs may be accelerated in immunological and allergic disorders. Depending on the sites evaluated, the presence or absence of oxidative stress in chronic urticaria is controversial. To our knowledge, this is the first study showing the possible involvement of AOPPs in CSU. The different behaviour observed for these two biomarkers is very likely due to the activation of specific related biochemical pathways associated with the condition under study.

  19. Effects of acute and chronic psychological stress on platelet aggregation in mice.

    Science.gov (United States)

    Matsuhisa, Fumikazu; Kitamura, Nobuo; Satoh, Eiki

    2014-03-01

    Although psychological stress has long been known to alter cardiovascular function, there have been few studies on the effect of psychological stress on platelets, which play a pivotal role in cardiovascular disease. In the present study, we investigated the effects of acute and chronic psychological stress on the aggregation of platelets and platelet cytosolic free calcium concentration ([Ca(2+)]i). Mice were subjected to both transportation stress (exposure to novel environment, psychological stress) and restraint stress (psychological stress) for 2 h (acute stress) or 3 weeks (2 h/day) (chronic stress). In addition, adrenalectomized mice were subjected to similar chronic stress (both transportation and restraint stress for 3 weeks). The aggregation of platelets from mice and [Ca(2+)]i was determined by light transmission assay and fura-2 fluorescence assay, respectively. Although acute stress had no effect on agonist-induced platelet aggregation, chronic stress enhanced the ability of the platelet agonists thrombin and ADP to stimulate platelet aggregation. However, chronic stress failed to enhance agonist-induced increase in [Ca(2+)]i. Adrenalectomy blocked chronic stress-induced enhancement of platelet aggregation. These results suggest that chronic, but not acute, psychological stress enhances agonist-stimulated platelet aggregation independently of [Ca(2+)]i increase, and the enhancement may be mediated by stress hormones secreted from the adrenal glands.

  20. Chronic stress, leukocyte subpopulations, and humoral response to latent viruses

    Energy Technology Data Exchange (ETDEWEB)

    McKinnon, W.; Weisse, C.S.; Reynolds, C.P.; Bowles, C.A.; Baum, A. (Uniformed Services Univ. of the Health Sciences, Bethesda, MD (USA))

    1989-01-01

    Psychological stress has been shown to affect immune system status and function, but most studies of this relationship have focused on acute stress and/or laboratory situations. The present study compared total numbers of leukocytes and lymphocyte subpopulations (determined by flow cytometry) and antibody titers to latent and nonlatent viruses among a group of chronically stressed individuals living near the damaged Three Mile Island (TMI) nuclear power plant with those of a demographically comparable control group. Urinary catecholamine and cortisol levels were also examined. Residents of the TMI area exhibited greater numbers of neutrophils, which were positively correlated with epinephrine levels. The TMI group also exhibited fewer B lymphocytes, T-suppressor/cytotoxic lymphocytes, and natural killer cells. Antibody titers to herpes simplex were significantly different across groups as well, whereas titers to nonlatent rubella virus as well as IgG and IgM levels were comparable.

  1. Chronic stress, leukocyte subpopulations, and humoral response to latent viruses

    International Nuclear Information System (INIS)

    McKinnon, W.; Weisse, C.S.; Reynolds, C.P.; Bowles, C.A.; Baum, A.

    1989-01-01

    Psychological stress has been shown to affect immune system status and function, but most studies of this relationship have focused on acute stress and/or laboratory situations. The present study compared total numbers of leukocytes and lymphocyte subpopulations (determined by flow cytometry) and antibody titers to latent and nonlatent viruses among a group of chronically stressed individuals living near the damaged Three Mile Island (TMI) nuclear power plant with those of a demographically comparable control group. Urinary catecholamine and cortisol levels were also examined. Residents of the TMI area exhibited greater numbers of neutrophils, which were positively correlated with epinephrine levels. The TMI group also exhibited fewer B lymphocytes, T-suppressor/cytotoxic lymphocytes, and natural killer cells. Antibody titers to herpes simplex were significantly different across groups as well, whereas titers to nonlatent rubella virus as well as IgG and IgM levels were comparable

  2. Toxic stress, inflammation and symptomatology of chronic complications in diabetes.

    Science.gov (United States)

    Downs, Charles A; Faulkner, Melissa Spezia

    2015-05-15

    Diabetes affects at least 382 million people worldwide and the incidence is expected to reach 592 million by 2035. The incidence of diabetes in youth is skyrocketing as evidenced by a 21% increase in type 1 diabetes and a 30.5% increase in type 2 diabetes in the United States between 2001 and 2009. The effects of toxic stress, the culmination of biological and environmental interactions, on the development of diabetes complications is gaining attention. Stress impacts the hypothalamus-pituitary-adrenal axis and contributes to inflammation, a key biological contributor to the pathogenesis of diabetes and its associated complications. This review provides an overview of common diabetic complications such as neuropathy, cognitive decline, depression, nephropathy and cardiovascular disease. The review also provides a discussion of the role of inflammation and stress in the development and progression of chronic complications of diabetes, associated symptomatology and importance of early identification of symptoms of depression, fatigue, exercise intolerance and pain.

  3. Chronic Vortioxetine Treatment Reduces Exaggerated Expression of Conditioned Fear Memory and Restores Active Coping Behavior in Chronically Stressed Rats.

    Science.gov (United States)

    Hatherall, Lauren; Sánchez, Connie; Morilak, David A

    2017-04-01

    Stress is a risk factor for depression and anxiety disorders, disrupting neuronal processes leading to exaggerated fear and compromised coping behaviors. Current antidepressants are only partially effective. Vortioxetine, a novel multimodal antidepressant, is a serotonin transporter inhibitor; 5-HT3, 5-HT7, and 5-HT1D receptor antagonist; 5-HT1B partial agonist; and 5-HT1A agonist. We have shown that chronic dietary vortioxetine administration reversed stress-induced deficits in cognitive flexibility. In the present studies, we investigated the generality of vortioxetine's effects on other stress-related behavioral changes after different types of chronic stress. In experiment 1, rats were fear-conditioned by pairing a tone with footshock, then exposed to chronic plus acute prolonged stress. In experiment 2, rats were exposed to chronic unpredictable stress. In both experiments, beginning on day 4 of chronic stress, vortioxetine was given in the diet (24 mg/kg/d). In experiment 1, effects of vortioxetine were tested on stress-induced changes in retention and extinction of cue-conditioned fear, and in experiment 2, on coping behavior on the shock probe defensive burying test after chronic stress. Chronic stress exaggerated the expression of conditioned fear memory. Vortioxetine restored fear memory to control levels and rendered extinction in stressed rats comparable with that in controls. In experiment 2, chronic unpredictable stress caused a shift from active to passive coping behavior, and vortioxetine restored active coping. Vortioxetine reduced exaggerated expression of conditioned fear and restored adaptive coping behavior following 2 different types of chronic stress, adding to the evidence of its therapeutic potential in the management of depression and anxiety disorders.

  4. Compatible bacterial mixture, tolerant to desiccation, improves maize plant growth

    Science.gov (United States)

    Molina-Romero, Dalia; Baez, Antonino; Quintero-Hernández, Verónica; Castañeda-Lucio, Miguel; Fuentes-Ramírez, Luis Ernesto; Bustillos-Cristales, María del Rocío; Rodríguez-Andrade, Osvaldo; Morales-García, Yolanda Elizabeth; Munive, Antonio

    2017-01-01

    Plant growth-promoting rhizobacteria (PGPR) increase plant growth and crop productivity. The inoculation of plants with a bacterial mixture (consortium) apparently provides greater benefits to plant growth than inoculation with a single bacterial strain. In the present work, a bacterial consortium was formulated containing four compatible and desiccation-tolerant strains with potential as PGPR. The formulation had one moderately (Pseudomonas putida KT2440) and three highly desiccation-tolerant (Sphingomonas sp. OF178, Azospirillum brasilense Sp7 and Acinetobacter sp. EMM02) strains. The four bacterial strains were able to adhere to seeds and colonize the rhizosphere of plants when applied in both mono-inoculation and multi-inoculation treatments, showing that they can also coexist without antagonistic effects in association with plants. The effects of the bacterial consortium on the growth of blue maize were evaluated. Seeds inoculated with either individual bacterial strains or the bacterial consortium were subjected to two experimental conditions before sowing: normal hydration or desiccation. In general, inoculation with the bacterial consortium increased the shoot and root dry weight, plant height and plant diameter compared to the non-inoculated control or mono-inoculation treatments. The bacterial consortium formulated in this work had greater benefits for blue maize plants even when the inoculated seeds underwent desiccation stress before germination, making this formulation attractive for future field applications. PMID:29117218

  5. Compatible bacterial mixture, tolerant to desiccation, improves maize plant growth.

    Science.gov (United States)

    Molina-Romero, Dalia; Baez, Antonino; Quintero-Hernández, Verónica; Castañeda-Lucio, Miguel; Fuentes-Ramírez, Luis Ernesto; Bustillos-Cristales, María Del Rocío; Rodríguez-Andrade, Osvaldo; Morales-García, Yolanda Elizabeth; Munive, Antonio; Muñoz-Rojas, Jesús

    2017-01-01

    Plant growth-promoting rhizobacteria (PGPR) increase plant growth and crop productivity. The inoculation of plants with a bacterial mixture (consortium) apparently provides greater benefits to plant growth than inoculation with a single bacterial strain. In the present work, a bacterial consortium was formulated containing four compatible and desiccation-tolerant strains with potential as PGPR. The formulation had one moderately (Pseudomonas putida KT2440) and three highly desiccation-tolerant (Sphingomonas sp. OF178, Azospirillum brasilense Sp7 and Acinetobacter sp. EMM02) strains. The four bacterial strains were able to adhere to seeds and colonize the rhizosphere of plants when applied in both mono-inoculation and multi-inoculation treatments, showing that they can also coexist without antagonistic effects in association with plants. The effects of the bacterial consortium on the growth of blue maize were evaluated. Seeds inoculated with either individual bacterial strains or the bacterial consortium were subjected to two experimental conditions before sowing: normal hydration or desiccation. In general, inoculation with the bacterial consortium increased the shoot and root dry weight, plant height and plant diameter compared to the non-inoculated control or mono-inoculation treatments. The bacterial consortium formulated in this work had greater benefits for blue maize plants even when the inoculated seeds underwent desiccation stress before germination, making this formulation attractive for future field applications.

  6. Compatible bacterial mixture, tolerant to desiccation, improves maize plant growth.

    Directory of Open Access Journals (Sweden)

    Dalia Molina-Romero

    Full Text Available Plant growth-promoting rhizobacteria (PGPR increase plant growth and crop productivity. The inoculation of plants with a bacterial mixture (consortium apparently provides greater benefits to plant growth than inoculation with a single bacterial strain. In the present work, a bacterial consortium was formulated containing four compatible and desiccation-tolerant strains with potential as PGPR. The formulation had one moderately (Pseudomonas putida KT2440 and three highly desiccation-tolerant (Sphingomonas sp. OF178, Azospirillum brasilense Sp7 and Acinetobacter sp. EMM02 strains. The four bacterial strains were able to adhere to seeds and colonize the rhizosphere of plants when applied in both mono-inoculation and multi-inoculation treatments, showing that they can also coexist without antagonistic effects in association with plants. The effects of the bacterial consortium on the growth of blue maize were evaluated. Seeds inoculated with either individual bacterial strains or the bacterial consortium were subjected to two experimental conditions before sowing: normal hydration or desiccation. In general, inoculation with the bacterial consortium increased the shoot and root dry weight, plant height and plant diameter compared to the non-inoculated control or mono-inoculation treatments. The bacterial consortium formulated in this work had greater benefits for blue maize plants even when the inoculated seeds underwent desiccation stress before germination, making this formulation attractive for future field applications.

  7. Desiccation resistance of Chironomid larvae

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    Jan Frouz

    2015-07-01

    Full Text Available Resistance to desiccation in larvae of eight species of aquatic, semiaquatic and terrestrial chironomids (Pseudodiamesa branickii, Macropelopia sp., Prodiamesa olivacea, Micropsectra sp., Chironomus riparius, Chironomus dorsalis, Metriocnemus martini and Camptocladius stercorarius was studied. The larvae were desiccated in exicator at constant conditions (15 °C, 80% RH and changes in moisture and body water content was recorded. The LD-50 for loss of body water was calculated. The lowest resistance to loss of body water was found in larvae from subfamilies Tanypodinae and Diamesinae Macropelopia sp. and P. branickii. They survived loss of 49.7 and 56.6% of original water content (presented values are LD-50. On the other hand the highest resistance to water loss was found in C. dorsalis. M. martini and C. stercorarius. The larvae of these species may survive loss of 67.4, 76.6 and 84.2% of original water content. Nevertheless the survival time under experimental conditions depends more closely on larval size than on lethal level of water loss. The smaller larvae desiccated faster and perished sooner than large ones despite they tolerate higher loss of body water.

  8. The contribution of posttraumatic stress symptoms to chronic pain adjustment.

    Science.gov (United States)

    Ruiz-Párraga, Gema T; López-Martínez, Alicia E

    2014-09-01

    To examine whether there are differences between non-trauma-exposed, trauma-exposed without posttraumatic stress symptoms (PSS), and trauma-exposed with PSS chronic musculoskeletal pain patients in vulnerability, protective, and pain-adjustment variables; to test the interactive relationship between PSS and the vulnerability and protective psychological variables across pain adjustment in the group of trauma-exposed-patients. Seven hundred and fourteen patients with chronic musculoskeletal pain were assessed. Of these, 346 patients (244 women and 102 men) completed the study (117 non-trauma-exposed, 119 trauma-exposed without PSS, and 110 trauma-exposed with PSS). The instruments used were the Stressful Life Event Screening Questionnaire Revised, Davidson Trauma Scale, Anxiety Sensitivity Index, Acceptance and Action Questionnaire, Pain Catastrophizing Scale, Fear-Avoidance Beliefs Questionnaire, Pain Anxiety Symptoms Scale, Pain Vigilance and Awareness Questionnaire, Resilience Scale, Chronic Pain Acceptance Questionnaire, Pain Numerical Rating Scale, Roland Morris Disability Questionnaire, and Hospital Anxiety and Depression Scale. Eight ANCOVAs showed that there were statistically significant differences in vulnerability, protection, and pain adjustment variables between the trauma-exposed with PSS patients and the other 2 groups. The moderated multiple regression analyses showed that PSS added a significantly incremental variance to pain intensity, emotional distress, and disability when interacting with vulnerability and protection variables. The current study supports the models of posttraumatic stress and chronic pain, such as the mutual maintenance and the shared vulnerability theories, providing an initial comprehensive framework for understanding the comorbidity of both disorders. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

  9. Bidirectional crosstalk between stress-induced gastric ulcer and depression under chronic stress.

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    Shuang Zhang

    Full Text Available Stress contributes to a variety of diseases and disorders such as depression and peptic ulcer. The present study aimed to investigate the correlation between stress ulcer and depression in pathogenesis and treatment by using chronic stress depression (CSD, chronic psychological stress ulcer (CPSU and water immersion restrain stress models in rats. Our data showed that the ulcer index of the animals after CSD exposure was significantly higher than that of controls. Depression-like behaviors were observed in rat after CPSU exposure. Fluoxetine hydrochloride significantly reduced the ulcer index of rats exposed to CPSU stress, while ranitidine inhibited depression-like behavior of the animals in CSD group. The ulcer index of rats administered with mifepristone after CPSU stress was markedly reduced compared to CPSU group, although there was no significant difference in the depression-like behavior between mifepristone-treated CSD group and naive controls. We also found that the rats exposed to CPSU or CSD stress displayed a lower level of corticosterone than naive controls, however, the acute stress (AS group showed an opposite result. Additionally, in order to study the relevance of H(2 receptors and depression, we treated the CSD group with cimetidine and famotidine respectively. The data showed that cimetidine inhibited depression-like behavior in CSD rats, and famotidine had no impact on depression. Overall our data suggested that the hypothalamic-pituitary-adrenal (HPA axis dysfunction may be the key role in triggering depression and stress ulcer. Acid-suppressing drugs and antidepressants could be used for treatment of depression and stress ulcer respectively. The occurrence of depression might be inhibited by blocking the central H(2 receptors.

  10. Enhanced Sleep Is an Evolutionarily Adaptive Response to Starvation Stress in Drosophila.

    Science.gov (United States)

    Slocumb, Melissa E; Regalado, Josue M; Yoshizawa, Masato; Neely, Greg G; Masek, Pavel; Gibbs, Allen G; Keene, Alex C

    2015-01-01

    Animals maximize fitness by modulating sleep and foraging strategies in response to changes in nutrient availability. Wild populations of the fruit fly, Drosophila melanogaster, display highly variable levels of starvation and desiccation resistance that differ in accordance with geographic location, nutrient availability, and evolutionary history. Further, flies potently modulate sleep in response to changes in food availability, and selection for starvation resistance enhances sleep, revealing strong genetic relationships between sleep and nutrient availability. To determine the genetic and evolutionary relationship between sleep and nutrient deprivation, we assessed sleep in flies selected for desiccation or starvation resistance. While starvation resistant flies have higher levels of triglycerides, desiccation resistant flies have enhanced glycogen stores, indicative of distinct physiological adaptations to food or water scarcity. Strikingly, selection for starvation resistance, but not desiccation resistance, leads to increased sleep, indicating that enhanced sleep is not a generalized consequence of higher energy stores. Thermotolerance is not altered in starvation or desiccation resistant flies, providing further evidence for context-specific adaptation to environmental stressors. F2 hybrid flies were generated by crossing starvation selected flies with desiccation selected flies, and the relationship between nutrient deprivation and sleep was examined. Hybrids exhibit a positive correlation between starvation resistance and sleep, while no interaction was detected between desiccation resistance and sleep, revealing that prolonged sleep provides an adaptive response to starvation stress. Therefore, these findings demonstrate context-specific evolution of enhanced sleep in response to chronic food deprivation, and provide a model for understanding the evolutionary relationship between sleep and nutrient availability.

  11. Desiccation survival in an Antarctic nematode: molecular analysis using expressed sequenced tags

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    Wall Diana H

    2009-02-01

    Full Text Available Abstract Background Nematodes are the dominant soil animals in Antarctic Dry Valleys and are capable of surviving desiccation and freezing in an anhydrobiotic state. Genes induced by desiccation stress have been successfully enumerated in nematodes; however we have little knowledge of gene regulation by Antarctic nematodes which can survive multiple environmental stresses. To address this problem we investigated the genetic responses of a nematode species, Plectus murrayi, that is capable of tolerating Antarctic environmental extremes, in particular desiccation and freezing. In this study, we provide the first insight into the desiccation induced transcriptome of an Antarctic nematode through cDNA library construction and suppressive subtractive hybridization. Results We obtained 2,486 expressed sequence tags (ESTs from 2,586 clones derived from the cDNA library of desiccated P. murrayi. The 2,486 ESTs formed 1,387 putative unique transcripts of which 523 (38% had matches in the model-nematode Caenorhabditis elegans, 107 (7% in nematodes other than C. elegans, 153 (11% in non-nematode organisms and 605 (44% had no significant match to any sequences in the current databases. The 1,387 unique transcripts were functionally classified by using Gene Ontology (GO hierarchy and the Kyoto Encyclopedia of Genes and Genomes (KEGG database. The results indicate that the transcriptome contains a group of transcripts from diverse functional areas. The subtractive library of desiccated nematodes showed 80 transcripts differentially expressed during desiccation stress, of which 28% were metabolism related, 19% were involved in environmental information processing, 28% involved in genetic information processing and 21% were novel transcripts. Expression profiling of 14 selected genes by quantitative Real-time PCR showed 9 genes significantly up-regulated, 3 down-regulated and 2 continuously expressed in response to desiccation. Conclusion The establishment of a

  12. Stellate ganglion block attenuates chronic stress induced depression in rats.

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    Weiwei Wang

    Full Text Available Stress is a significant factor in the etiology of depression. Stellate ganglion block (SGB has been shown to maintain the stability of the autonomic system and to affect the neuroendocrine system, including the hypothalamic-pituitary-adrenal (HPA axis. The objective of this study was to determine the antidepressant-like effects of SGB on the autonomic system and the HPA axis, apoptosis-related proteins, related spatial learning and memory impairment, and sensorimotor dysfunction.Forty-eight Sprague Dawley rats were assigned to four experimental groups: control + saline (sham group, control + SGB (SGB group, unpredictable chronic mild stress (UCMS + saline (UCMS group, and UCMS + SGB (UCSG group. Stress-induced effects and the function of SGB were assessed using measures of body weight, coat state, sucrose consumption, and behavior in open-field and Y-maze tests. Neuronal damage was assessed histologically using the hematoxylin-eosin (HE staining method, while western blotting was used to investigate changes in the expression of apoptosis-related proteins. Plasma corticotropin-releasing factor (CRF, adrenocorticotropic hormone (ACTH, corticosterone (CORT, noradrenaline and adrenaline were measured to evaluate changes in the autonomic system and HPA axis.SGB treatment significantly improved sensorimotor dysfunction and spatial learning and memory impairment following UCMS. Moreover, UCMS significantly decreased body weight, sucrose preference and anti-apoptotic protein Bcl-2, and increased scores on measures of coat state, adrenal gland weight, levels of CORT, CRF, ACTH, noradrenaline and adrenaline, as well as increased neuronal loss, cell shrinkage, nuclear condensation, and the pro-apoptotic protein Bax. These symptoms were attenuated by treatment with SGB.These findings suggest that SGB can attenuate depression-like behaviors induced by chronic stress. These protective effects appear to be due to an anti-apoptotic mechanism of two stress

  13. Aquatic insects dealing with dehydration: do desiccation resistance traits differ in species with contrasting habitat preferences?

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    Susana Pallarés

    2016-08-01

    Full Text Available Background Desiccation resistance shapes the distribution of terrestrial insects at multiple spatial scales. However, responses to drying stress have been poorly studied in aquatic groups, despite their potential role in constraining their distribution and diversification, particularly in arid and semi-arid regions. Methods We examined desiccation resistance in adults of four congeneric water beetle species (Enochrus, family Hydrophilidae with contrasting habitat specificity (lentic vs. lotic systems and different salinity optima from fresh- to hypersaline waters. We measured survival, recovery capacity and key traits related to desiccation resistance (fresh mass, % water content, % cuticle content and water loss rate under controlled exposure to desiccation, and explored their variability within and between species. Results Meso- and hypersaline species were more resistant to desiccation than freshwater and hyposaline ones, showing significantly lower water loss rates and higher water content. No clear patterns in desiccation resistance traits were observed between lotic and lentic species. Intraspecifically, water loss rate was positively related to specimens’ initial % water content, but not to fresh mass or % cuticle content, suggesting that the dynamic mechanism controlling water loss is mainly regulated by the amount of body water available. Discussion Our results support previous hypotheses suggesting that the evolution of desiccation resistance is associated with the colonization of saline habitats by aquatic beetles. The interespecific patterns observed in Enochrus also suggest that freshwater species may be more vulnerable than saline ones to drought intensification expected under climate change in semi-arid regions such as the Mediterranean Basin.

  14. Identification of proteins involved in desiccation tolerance in the red seaweed Pyropia orbicularis (Rhodophyta, Bangiales).

    Science.gov (United States)

    López-Cristoffanini, Camilo; Zapata, Javier; Gaillard, Fanny; Potin, Philippe; Correa, Juan A; Contreras-Porcia, Loretto

    2015-12-01

    Extreme reduction in cellular water content leads to desiccation, which, if persistent, affects the physiology of organisms, mainly through oxidative stress. Some organisms are highly tolerant to desiccation, including resurrection plants and certain intertidal seaweeds. One such species is Pyropia orbicularis, a rhodophycean that colonizes upper intertidal zones along the Chilean coast. Despite long, daily periods of air exposure due to tides, this alga is highly tolerant to desiccation. The present study examined the proteome of P. orbicularis by 2DE and LC-MS/MS analyses to determine the proteins associated with desiccation tolerance (DT). The results showed that, under natural conditions, there were significant changes in the protein profile during low tide as compared to naturally hydrated plants at high tide. These changes were mainly in newly appeared proteins spots such as chaperones, monodehydroascorbate reductase, and manganese superoxide dismutase, among others. Previously undescribed proteins under desiccation conditions included phycobiliproteins, glyoxalase I, and phosphomannomutase. These changes evidenced that several physiological responses involved in DT are activated during low tide, including decreased photosynthetic activity, increased antioxidant capacity, and the preservation of cell physiology by regulating water content, cell wall structure, and cell volume. Similar responses have been observed in resurrection plants and bryophytes exposed to desiccation. Therefore, the coordinated activation of different desiccation tolerance pathways in P. orbicularis could explain the successful biological performance of this seaweed in the upper intertidal rocky zones. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Aquatic insects dealing with dehydration: do desiccation resistance traits differ in species with contrasting habitat preferences?

    Science.gov (United States)

    Pallarés, Susana; Velasco, Josefa; Millán, Andrés; Bilton, David T; Arribas, Paula

    2016-01-01

    Desiccation resistance shapes the distribution of terrestrial insects at multiple spatial scales. However, responses to drying stress have been poorly studied in aquatic groups, despite their potential role in constraining their distribution and diversification, particularly in arid and semi-arid regions. We examined desiccation resistance in adults of four congeneric water beetle species (Enochrus, family Hydrophilidae) with contrasting habitat specificity (lentic vs. lotic systems and different salinity optima from fresh- to hypersaline waters). We measured survival, recovery capacity and key traits related to desiccation resistance (fresh mass, % water content, % cuticle content and water loss rate) under controlled exposure to desiccation, and explored their variability within and between species. Meso- and hypersaline species were more resistant to desiccation than freshwater and hyposaline ones, showing significantly lower water loss rates and higher water content. No clear patterns in desiccation resistance traits were observed between lotic and lentic species. Intraspecifically, water loss rate was positively related to specimens' initial % water content, but not to fresh mass or % cuticle content, suggesting that the dynamic mechanism controlling water loss is mainly regulated by the amount of body water available. Our results support previous hypotheses suggesting that the evolution of desiccation resistance is associated with the colonization of saline habitats by aquatic beetles. The interespecific patterns observed in Enochrus also suggest that freshwater species may be more vulnerable than saline ones to drought intensification expected under climate change in semi-arid regions such as the Mediterranean Basin.

  16. Impact of chronic maternal stress during early gestation on maternal-fetal stress transfer and fetal stress sensitivity in sheep.

    Science.gov (United States)

    Dreiling, Michelle; Schiffner, Rene; Bischoff, Sabine; Rupprecht, Sven; Kroegel, Nasim; Schubert, Harald; Witte, Otto W; Schwab, Matthias; Rakers, Florian

    2018-01-01

    Acute stress-induced reduction of uterine blood flow (UBF) is an indirect mechanism of maternal-fetal stress transfer during late gestation. Effects of chronic psychosocial maternal stress (CMS) during early gestation, as may be experienced by many working women, on this stress signaling mechanism are unclear. We hypothesized that CMS in sheep during early gestation augments later acute stress-induced decreases of UBF, and aggravates the fetal hormonal, cardiovascular, and metabolic stress responses during later development. Six pregnant ewes underwent repeated isolation stress (CMS) between 30 and 100 days of gestation (dGA, term: 150 dGA) and seven pregnant ewes served as controls. At 110 dGA, ewes were chronically instrumented and underwent acute isolation stress. The acute stress decreased UBF by 19% in both the CMS and control groups (p stress-induced cortisol and norepinephrine concentrations indicating a hyperactive hypothalamus-pituitary-adrenal (HPA)-axis and sympathetic-adrenal-medullary system. Increased fetal norepinephrine is endogenous as maternal catecholamines do not cross the placenta. Cortisol in the control but not in the CMS fetuses was correlated with maternal cortisol blood concentrations; these findings indicate: (1) no increased maternal-fetal cortisol transfer with CMS, (2) cortisol production in CMS fetuses when the HPA-axis is normally inactive, due to early maturation of the fetal HPA-axis. CMS fetuses were better oxygenated, without shift towards acidosis compared to the controls, potentially reflecting adaptation to repeated stress. Hence, CMS enhances maternal-fetal stress transfer by prolonged reduction in UBF and increased fetal HPA responsiveness.

  17. Desiccant cooling system performance: A simple approach

    Science.gov (United States)

    Epstein, M.; Grolmes, M. A.

    1982-10-01

    The wave nature of heat and mass transfer in fixed desiccant bed adsorption is explained. A simple algebraic model of wave motion under single low desiccant bed operation is developed and applied to the prediction of the performance potential of the overall desiccant cooling system. The model is used to explain the increase in cooling system performance that is realized through the use of mixed inert desiccant material adsorption beds. The response of cooling system performance to changes in external process conditions is examined and conclusions are drawn relative to optimization of system characteristics.

  18. 3, 4-methylenedioximethamphetamin reverses anxiety induced by chronic mild stress

    Directory of Open Access Journals (Sweden)

    Laura Andrea León A

    2013-01-01

    Full Text Available Here we report the effects of subchronic 3, 4 methylenedioximethamphetamine (MDMA on the elevated plusmaze, a widely used animal model of anxiety. Rats exposed to a mild chronic stress (MCS protocol received intracerebroventricular microinjections of the selective serotonin reuptake inhibitor (SSRI – fluoxetine (2.0 ug/ul or MDMA, (2.0 ug/ul for seven days. On the eighth day rats were tested in the elevated plus-maze. Our results showed that sub chronic MDMA interacted with MCS leading to a decrease in anxiety related behaviors including: percentage of open arms entries (F [2, 26] = 4.00; p = 0.031, time spent in the open arms (F [2, 26] = 3.656; p = 0.040 and time spent in the open arms extremities (F [2, 26] = 5.842; p = 0.008. These results suggest a potential effect of MDMA in the reversion of the emotional significance of aversive stimuli.

  19. Interaction of metabolic stress with chronic mild stress in altering brain cytokines and sucrose preference.

    Science.gov (United States)

    Remus, Jennifer L; Stewart, Luke T; Camp, Robert M; Novak, Colleen M; Johnson, John D

    2015-06-01

    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).

  20. Enhanced Desiccation Tolerance in Mature Cultures of the Streptophytic Green Alga Zygnema circumcarinatum Revealed by Transcriptomics.

    Science.gov (United States)

    Rippin, Martin; Becker, Burkhard; Holzinger, Andreas

    2017-12-01

    Desiccation tolerance is commonly regarded as one of the key features for the colonization of terrestrial habitats by green algae and the evolution of land plants. Extensive studies, focused mostly on physiology, have been carried out assessing the desiccation tolerance and resilience of the streptophytic genera Klebsormidium and Zygnema. Here we present transcriptomic analyses of Zygnema circumcarinatum exposed to desiccation stress. Cultures of Z. circumcarinatum grown in liquid medium or on agar plates were desiccated at ∼86% relative air humidity until the effective quantum yield of PSII [Y(II)] ceased. In general, the response to dehydration was much more pronounced in Z. circumcarinatum cultured in liquid medium for 1 month compared with filaments grown on agar plates for 7 and 12 months. Culture on solid medium enables the alga to acclimate to dehydration much better and an increase in desiccation tolerance was clearly correlated to increased culture age. Moreover, gene expression analysis revealed that photosynthesis was strongly repressed upon desiccation treatment in the liquid culture while only minor effects were detected in filaments cultured on agar plates for 7 months. Otherwise, both samples showed induction of stress protection mechanisms such as reactive oxygen species scavenging (early light-induced proteins, glutathione metabolism) and DNA repair as well as the expression of chaperones and aquaporins. Additionally, Z. circumcarinatum cultured in liquid medium upregulated sucrose-synthesizing enzymes and strongly induced membrane modifications in response to desiccation stress. These results corroborate the previously described hardening and associated desiccation tolerance in Zygnema in response to seasonal fluctuations in water availability. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  1. Comfort food is comforting to those most stressed: evidence of the chronic stress response network in high stress women.

    Science.gov (United States)

    Tomiyama, A Janet; Dallman, Mary F; Epel, Elissa S

    2011-11-01

    Chronically stressed rodents who are allowed to eat calorie-dense "comfort" food develop greater mesenteric fat, which in turn dampens hypothalamic-pituitary-adrenocortical (HPA) axis activity. We tested whether similar relations exist in humans, at least cross-sectionally. Fifty-nine healthy premenopausal women were exposed to a standard laboratory stressor to examine HPA response to acute stress and underwent diurnal saliva sampling for basal cortisol and response to dexamethasone administration. Based on perceived stress scores, women were divided into extreme quartiles of low versus high stress categories. We found as hypothesized that the high stress group had significantly greater BMI and sagittal diameter, and reported greater emotional eating. In response to acute lab stressor, the high stress group showed a blunted cortisol response, lower diurnal cortisol levels, and greater suppression in response to dexamethasone. These cross-sectional findings support the animal model, which suggests that long-term adaptation to chronic stress in the face of dense calories result in greater visceral fat accumulation (via ingestion of calorie-dense food), which in turn modulates HPA axis response, resulting in lower cortisol levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Lysozyme association with circulating RNA, extracellular vesicles, and chronic stress.

    Science.gov (United States)

    Abey, Sarah K; Yuana, Yuana; Joseph, Paule V; Kenea, Natnael D; Fourie, Nicolaas H; Sherwin, LeeAnne B; Gonye, Gregory E; Smyser, Paul A; Stempinski, Erin S; Boulineaux, Christina M; Weaver, Kristen R; Bleck, Christopher K E; Henderson, Wendy A

    2017-06-01

    Stress has demonstrated effects on inflammation though underlying cell-cell communication mechanisms remain unclear. We hypothesize that circulating RNAs and extracellular vesicles (EVs) in patients with chronic stress contain signals with functional roles in cell repair. Blood transcriptome from patients with Irritable Bowel Syndrome versus controls were compared to identify signaling pathways and effectors. Plasma EVs were isolated (size-exclusion chromatography) and characterized for effectors' presence (immunogold labelling-electron microscopy). Based on transcriptome pathways and EV-labelling, lysozyme's effects on cell migration were tested in human colon epithelial CRL-1790 cells and compared to the effects of CXCL12, a migration inducer (wound assay). The effect of lysozyme on immune-linked mRNA and protein levels in cells which survived following serum starvation and scratch wound were investigated (NanoString). Blood transcriptomes revealed pyridoxal 5'phosphate salvage, pyrimidine ribonucleotides salvage pathways, atherosclerosis, and cell movement signaling with membrane CD9 and extracellular lysozyme as effectors. Plasma EVs showed labelling with CD9, mucins, and lysozyme. This is the first identification of lysozyme on plasma EVs. In CRL-1790 cells, lysozyme induced migration and repaired scratch wound as well as CXCL12. Immune mRNA and protein expressions were altered in cells which survived following serum starvation and scratch wound, with or without lysozyme in serum-free media post-wounding: CD9, IL8, IL6 mRNAs and CD9, NT5E, PD-L1 proteins. Repair and inflammatory signals are identified in plasma EVs and circulating RNAs in chronic stress. Registered clinicaltrials.gov #NCT00824941. This study highlights the role of circulating RNAs and EVs in stress.

  3. Desiccation and heat tolerance of Enterobacter sakazakii.

    Science.gov (United States)

    Breeuwer, P; Lardeau, A; Peterz, M; Joosten, H M

    2003-01-01

    Enterobacter sakazakii is an opportunistic pathogen which has been isolated at low levels from powdered infant formulas. This study was performed to demonstrate that Ent. sakazakii is not particularly thermotolerant, but can adapt to osmotic and dry stress. We determined the heat, osmotic and dry stress resistance of Ent. sakazakii. The D-value at 58 degrees C ranged from 0.39 to 0.60 min, which is comparable with that of other Enterobacteriaceae, but much lower than reported previously (Nazarowec-White and Farber 1997, Letters in Applied Microbiology 24: 9-13). However, stationary phase Ent. sakazakii cells were found to be more resistant to osmotic and dry stress than Escherichia coli, Salmonella and other strains of Enterobacteriaceae tested. Further analysis indicated that the dry resistance is most likely linked to accumulation of trehalose in the cells. The high tolerance to desiccation provides a competitive advantage for Ent. sakazakii in dry environments, as found in milk powder factories, and thereby increases the risk of postpasteurization contamination of the finished product. Understanding of the physiology and survival strategies of Ent. sakazakii is an important step in the efforts to eliminate this bacterium from the critical food production environments.

  4. A consensus endocrine profile for chronically stressed wild animals does not exist.

    Science.gov (United States)

    Dickens, Molly J; Romero, L Michael

    2013-09-15

    Given the connection between chronic stress and health, there has been a growing emphasis on identifying chronically stressed wild animals, especially in relation to anthropogenic disturbances. There is considerable confusion, however, in how to identify chronically stressed wild animals, but the most common assumption is that measures of glucocorticoid (GC) function will increase. In an attempt to determine an "endocrine profile" of a chronically stressed wild animal, this review collected papers from the literature that measured baseline GC, stress-induced GC, measures of integrated GC, negative feedback, hypothalamic-pituitary-adrenal axis sensitivity, and/or body weight in chronically stressed animals. The collected studies encompassed laboratory and field studies, numerous diverse species, and multiple techniques for inducing chronic stress. Each paper was ranked according to its relevance to wild animals and scored as to whether the measured response increased, decreased, or stayed the same after exposure to chronic stress. The analyses uncovered so much variation between studies that the literature does not support a generalized endocrine profile in how wild animals respond to chronic stress. The common predictions appear to be based almost entirely on theoretical models rather than empirical data. The three most important variables affecting GC responses were the stressors used to induce chronic stress, the potential for those stressors to induce habituation, and the taxon of the focal species. The best approach for identifying a chronically stressed population appears to be documentation of changes at multiple levels of GC regulation, but the direction of the change (increase or decrease) may be relatively unimportant compared to the fact that the response changes at all. The conclusion is that a consistent, predictable, endocrine response to chronic stress, regardless of the protocol used to induce chronic stress and the species under study, does not

  5. Stressful Presentations: Mild Chronic Cold Stress in Mice Influences Baseline Properties of Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Kathleen Marie Kokolus

    2014-02-01

    Full Text Available The ability of dendritic cells to stimulate and regulate T cells is critical to effective anti-tumor immunity. Therefore, it is important to fully recognize any inherent factors which may influence DC function under experimental conditions, especially in laboratory mice since they are used so heavily to study immune responses. Physiological stress is well recognized to impair several arms of immune protection. The goals of this report are to briefly summarize previous work revealing how DCs respond to various forms of physiologically relevant stress and to present new data highlighting the potential for chronic mild cold stress inherent in mice housed at standard ambient temperatures required for laboratory mice to influence baseline DCs properties. Since recent data from our group shows that CD8+ T cell function is altered by mild chronic cold stress and since DC function is crucial for CD8+ T cell activation, we wondered whether mild cold stress may also be influencing DC properties. We found increased numbers of splenic DCs (CD11c+ in cold stressed mice compared to mice housed at a thermoneutral temperature, which significantly reduces cold stress. However, many of the DCs which are expanded in cold stressed mice express an immature phenotype. We also found that antigen presentation and ability of splenocytes to activate T cells were impaired compared to that seen in DCs isolated from mice at thermoneutrality. The new data presented here strongly suggest that the housing temperature of mice can affect fundamental properties of DC function which in turn could be influencing the response of DCs to added experimental stressors or other treatments.

  6. Differential longevities in desiccated anhydrobiotic plant systems

    NARCIS (Netherlands)

    Hoekstra, F.A.

    2005-01-01

    Desiccation tolerance is a wide-spread phenomenon in the plant kingdom, particularly in small propagules lacking own root or rhizome system, such as seeds, pollen, spores of spore plants, and whole moss plants, but rare in whole, vascular plants. Longevities in the desiccated state vary from a few

  7. Unravelling desiccation tolerance in germinated Arabidopsis seeds

    NARCIS (Netherlands)

    Maia de Oliveira, J.

    2014-01-01

    How different organisms survive in the absence or under very limited amounts of water is still an open question. The aim of the research presented in this thesis is to explore the molecular basis of desiccation tolerance in seeds. We investigated the possibilities of using germinated desiccation

  8. Steady state modeling of desiccant wheels

    DEFF Research Database (Denmark)

    Bellemo, Lorenzo; Elmegaard, Brian; Kærn, Martin Ryhl

    2014-01-01

    systems. A steady state two-dimensional model is formulated and implemented aiming to obtain good accuracy and short computational times. Comparison with experimental data from the literature shows that the model reproduces the physical behavior of desiccant wheels. Mass diffusion in the desiccant should...

  9. Variation of desiccation tolerance and longevity in fern spores.

    Science.gov (United States)

    Ballesteros, Daniel; Hill, Lisa M; Walters, Christina

    2017-04-01

    This work contributes to the understanding of plant cell responses to extreme water stress when it is applied at different intensity and duration. Fern spores are used to explore survival at relative humidity (RH)moisture level. A RH of 10-25% corresponds well to sorption behavior parameters and is below the glass transition, measured using differential scanning calorimetry. Though response to RH was similar among species, the kinetics of deterioration varied considerably among species and this implies differences in the structure or mobility of molecules within the solidified cytoplasm. Our work suggests that desiccation damage occurs in desiccation tolerant cells, and that it is expressed as a time-dependent response, otherwise known as aging. Copyright © 2017 Elsevier GmbH. All rights reserved.

  10. Extreme stress and mental health: immigrant syndrome with chronic and multiple stress (the Ulysses syndrome

    Directory of Open Access Journals (Sweden)

    Joseba Achotegui Loizate

    2014-11-01

    Full Text Available Today, for millions of individuals, emigration presents stress levels of such intensity that they exceed the human capacity of adaptation: loneliness and the enforced separation from one’s loved ones, the failure of the migratory project, the experiencing of extreme hard ships and terror... These persons are, therefore, highly vulnerable to the Immigrant Syndrome with Chronic and Multiple Stress (the Ulysses Syndrome, in reference to the Greek hero who suffered countless adversities and dangers in lands far from his loved ones.We consider that a direct and unequivocal relationship exists between the stress limits which these immigrants experience and the symptomatology of The Ulysses Syndrome and that this Syndromeis found in the limit between the area of mental health and the area of psychopathology.

  11. Food cravings mediate the relationship between chronic stress and body mass index.

    Science.gov (United States)

    Chao, Ariana; Grilo, Carlos M; White, Marney A; Sinha, Rajita

    2015-06-01

    This study examined the relationships between chronic stress, food cravings, and body mass index. A community-based sample of adults (N = 619) completed a comprehensive assessment battery and heights and weights were measured. Chronic stress had a significant direct effect on food cravings, and food cravings had a significant direct effect on body mass index. The total effect of chronic stress on body mass index was significant. Food cravings partially mediated the relationship between chronic stress and body mass index. These findings are consistent with research that chronic stress may potentiate motivation for rewarding substances and behaviors and indicate that high food cravings may contribute to stress-related weight gain. © The Author(s) 2015.

  12. The Community Child Health Network Life Stress Interview: a brief chronic stress measure for community health research.

    Science.gov (United States)

    Tanner Stapleton, Lynlee R; Dunkel Schetter, Christine; Dooley, Larissa N; Guardino, Christine M; Huynh, Jan; Paek, Cynthia; Clark-Kauffman, Elizabeth; Schafer, Peter; Woolard, Richard; Lanzi, Robin Gaines

    2016-07-01

    Chronic stress is implicated in many theories as a contributor to a wide range of physical and mental health problems. The current study describes the development of a chronic stress measure that was based on the UCLA Life Stress Interview (LSI) and adapted in collaboration with community partners for use in a large community health study of low-income, ethnically diverse parents of infants in the USA (Community Child Health Network [CCHN]). We describe the instrument, its purpose and adaptations, implementation, and results of a reliability study in a subsample of the larger study cohort. Interviews with 272 mothers were included in the present study. Chronic stress was assessed using the CCHN LSI, an instrument designed for administration by trained community interviewers to assess four domains of chronic stress, each rated by interviewers. Significant correlations ranging from small to moderate in size between chronic stress scores on this measure, other measures of stress, biomarkers of allostatic load, and mental health provide initial evidence of construct and concurrent validity. Reliability data for interviewer ratings are also provided. This relatively brief interview (15 minutes) is available for use and may be a valuable tool for researchers seeking to measure chronic stress reliably and validly in future studies with time constraints.

  13. Ghrelin, Appetite Regulation, and Food Reward: Interaction with Chronic Stress

    Directory of Open Access Journals (Sweden)

    Yolanda Diz-Chaves

    2011-01-01

    Full Text Available Obesity has become one of the leading causes of illness and mortality in the developed world. Preclinical and clinical data provide compelling evidence for ghrelin as a relevant regulator of appetite, food intake, and energy homeostasis. In addition, ghrelin has recently emerged as one of the major contributing factors to reward-driven feeding that can override the state of satiation. The corticotropin-releasing-factor system is also directly implicated in the regulation of energy balance and may participate in the pathophysiology of obesity and eating disorders. This paper focuses on the role of ghrelin in the regulation of appetite, on its possible role as a hedonic signal involved in food reward, and on its interaction with the corticotropin-releasing-factor system and chronic stress.

  14. Increased risk taking in relation to chronic stress in young adults

    Directory of Open Access Journals (Sweden)

    Smarandita eCeccato

    2016-01-01

    Full Text Available Chronic stress is a public health problem that affects a significant part of the population. While the physiological damage it causes is under ongoing scrutiny, its behavioral effects have been overlooked. This is one of the first studies to examine the relation between chronic stress and decision-making, using a standard lottery paradigm. We measured learning-independent risk taking in the gain domain through binary choices between financially incentivized lotteries. We then measured self-reported chronic stress with the Trier Inventory for the Assessment of Chronic Stress (TICS. We additionally collected hair samples in a subsample of volunteers, in order to quantify chronic cortisol exposure. We discovered a significant, positive correlation between self-reported chronic stress and risk taking that is stronger for women than for men. This confirms part of the findings in acute stress research that show a connection between higher stress and increased risk taking. However, unlike the biologically-based results from acute stress research, we did not identify a significant relation between hair cortisol and behavior. In line with previous literature, we found a clear gender difference in risk taking and self-reports: women generally take less risk and report slightly higher stress levels than men. We conclude that perceived chronic stress can impact behavior in risky situations.

  15. Oxidative Stress in Diabetic Nephropathy with Early Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Alejandra Guillermina Miranda-Díaz

    2016-01-01

    Full Text Available The increase in the prevalence of diabetes mellitus (DM and the secondary kidney damage produces diabetic nephropathy (DN. Early nephropathy is defined as the presence of microalbuminuria (30–300 mg/day, including normal glomerular filtration rate (GFR or a mildly decreased GFR (60–89 mL/min/1.73 m2, with or without overt nephropathy. The earliest change caused by DN is hyperfiltration with proteinuria. The acceptable excretion rate of albumin in urine is 300 mg/day. Chronic kidney disease (CKD is characterized by abnormalities in renal function that persist for >3 months with health implications. Alterations in the redox state in DN are caused by the persistent state of hyperglycemia and the increase in advanced glycation end products (AGEs with ability to affect the renin-angiotensin system and the transforming growth factor-beta (TGF-β, producing chronic inflammation and glomerular and tubular hypertrophy and favoring the appearance of oxidative stress. In DN imbalance between prooxidant/antioxidant processes exists with an increase in reactive oxygen species (ROS. The overproduction of ROS diminishes expression of the antioxidant enzymes (manganese superoxide dismutase, glutathione peroxidase, and catalase. The early detection of CKD secondary to DN and the timely identification of patients would permit decreasing its impact on health.

  16. Adaptation to desiccation fails to generate pre- and postmating isolation in replicate Drosophila melanogaster laboratory populations.

    Science.gov (United States)

    Kwan, Lucia; Rundle, Howard D

    2010-03-01

    Many laboratory speciation experiments have raised allopatric populations in different environments to determine whether reproductive isolation evolves as a byproduct of adaptation (a form of ecological speciation). Few, however, have addressed the evolution of both pre- and postmating isolation or investigated the conditions affecting the process. We present results of an evolution experiment in which 12 lines of Drosophila melanogaster were derived from a common population and then independently evolved for more than 57 generations under alternative selection treatments. Six "desiccation" populations had access to food and water removed during a period of their adult lives generating strong desiccation selection, and six "starvation" populations had access to food but not water removed for the same period, generating a mild starvation stress. Substantial divergence of cuticular hydrocarbons occurred between the desiccation and starvation populations, key traits that have been implicated in sexual isolation in Drosophila. Despite this divergence, there was no detectable premating isolation between desiccation and starvation populations and postmating isolation was asymmetrical: the fitness of F1 hybrids was reduced in the desiccation but not the starvation environment. This asymmetry was likely caused by the absence of divergent selection: adaptation to desiccation appears to have come at no cost to performance in the starvation environment. Novel environments are thought to promote the evolution of reproductive isolation. Understanding the conditions that favor or hamper this remains a key challenge for speciation research.

  17. Desiccation tolerance in Physcomitrella patens: Rate of dehydration and the involvement of endogenous abscisic acid (ABA).

    Science.gov (United States)

    Xiao, Lihong; Yobi, Abou; Koster, Karen L; He, Yikun; Oliver, Melvin J

    2018-01-01

    The moss Physcomitrella patens, a model system for basal land plants, tolerates several abiotic stresses, including dehydration. We previously reported that Physcomitrella patens survives equilibrium dehydration to -13 MPa in a closed system at 91% RH. Tolerance of desiccation to water potentials below -100 MPa was only achieved by pretreatment with exogenous abscisic acid (ABA). We report here that gametophores, but not protonemata, can survive desiccation below -100 MPa after a gradual drying regime in an open system, without exogenous ABA. In contrast, faster equilibrium drying at 90% RH for 3-5 days did not induce desiccation tolerance in either tissue. Endogenous ABA accumulated in protonemata and gametophores under both drying regimes, so did not correlate directly with desiccation tolerance. Gametophores of a Ppabi3a/b/c triple knock out transgenic line also survived the gradual dehydration regime, despite impaired ABA signaling. Our results suggest that the initial drying rate, and not the amount of endogenous ABA, may be critical in the acquisition of desiccation tolerance. Results from this work will provide insight into ongoing studies to uncover the role of ABA in the dehydration response and the underlying mechanisms of desiccation tolerance in this bryophyte. © 2017 John Wiley & Sons Ltd.

  18. Impaired Functional Connectivity in the Prefrontal Cortex: A Mechanism for Chronic Stress-Induced Neuropsychiatric Disorders

    Directory of Open Access Journals (Sweden)

    Ignacio Negrón-Oyarzo

    2016-01-01

    Full Text Available Chronic stress-related psychiatric diseases, such as major depression, posttraumatic stress disorder, and schizophrenia, are characterized by a maladaptive organization of behavioral responses that strongly affect the well-being of patients. Current evidence suggests that a functional impairment of the prefrontal cortex (PFC is implicated in the pathophysiology of these diseases. Therefore, chronic stress may impair PFC functions required for the adaptive orchestration of behavioral responses. In the present review, we integrate evidence obtained from cognitive neuroscience with neurophysiological research with animal models, to put forward a hypothesis that addresses stress-induced behavioral dysfunctions observed in stress-related neuropsychiatric disorders. We propose that chronic stress impairs mechanisms involved in neuronal functional connectivity in the PFC that are required for the formation of adaptive representations for the execution of adaptive behavioral responses. These considerations could be particularly relevant for understanding the pathophysiology of chronic stress-related neuropsychiatric disorders.

  19. Identification of Novel Desiccation-Tolerant S. cerevisiae Strains for Deep Space Biosensors

    Science.gov (United States)

    Tieze, Sofia Massaro; Santa Maria, Sergio R.; Liddell, Lauren C.; Bhattacharya, Sharmila

    2017-01-01

    NASA's BioSentinel mission, a secondary payload that will fly on the Space Launch System's first Exploration Mission (EM-1), utilizes the budding yeast S. cerevisiae to study the biological response to the deep space radiation environment. Yeast samples are desiccated prior to launch to suspend growth and metabolism while the spacecraft travels to its target heliocentric orbit beyond Low Earth Orbit. Each sample is then rehydrated at the desired time points to reactivate the cells. A major risk in this mission is the loss of cell viability that occurs in the recovery period following the desiccation and rehydration process. Cell survival is essential for the detection of the biological response to features in the deep space environment, including ionizing radiation. The aim of this study is to mitigate viable cell loss in future biosensors by identifying mutations and genes that confer tolerance to desiccation stress in rad51, a radiation-sensitive yeast strain. We initiated a screen for desiccation-tolerance after rehydrating cells that were desiccated for three years, and selected various clones exhibiting robust growth. To verify retention of radiation sensitivity in the isolated clones - a crucial feature for a successful biosensor - we exposed them to ionizing radiation. Finally, to elucidate the genetic and molecular bases for observed desiccation-tolerance, we will perform whole-genome sequencing of those rad51 clones that exhibit both robust growth and radiation sensitivity following desiccation. The identification and characterization of desiccation-tolerant strains will allow us to engineer a biological model that will be resilient in face of the challenges of the deep space environment, and will thus ensure the experimental success of future biosensor missions.

  20. Identification of Novel Desiccation-Tolerant S. cerevisiae Strains for Deep Space Biosensors

    Science.gov (United States)

    Tieze, Sofia Massaro; Santa Maria, Sergio R.; Liddell, Lauren; Bhattacharya, Sharmila

    2017-01-01

    NASA's BioSentinel mission, a secondary payload that will fly on the Space Launch Systems first Exploration Mission (EM-1), utilizes the budding yeast S. cerevisiae to study the biological response to the deep space radiation environment. Yeast samples are desiccated prior to launch to suspend growth and metabolism while the spacecraft travels to its target heliocentric orbit beyond Low Earth Orbit. Each sample is then rehydrated at the desired time points to reactivate the cells. A major risk in this mission is the loss of cell viability that occurs in the recovery period following the desiccation and rehydration process. Cell survival is essential for the detection of the biological response to features in the deep space environment, including ionizing radiation.The aim of this study is to mitigate viable cell loss in future biosensors by identifying mutations and genes that confer tolerance to desiccation stress in rad51, a radiation-sensitive yeast strain. We initiated a screen for desiccation-tolerance after rehydrating cells that were desiccated for three years, and selected various clones exhibiting robust growth. To verify retention of radiation sensitivity in the isolated clonesa crucial feature for a successful biosensorwe exposed them to ionizing radiation. Finally, to elucidate the genetic and molecular bases for observed desiccation-tolerance, we will perform whole-genome sequencing of those rad51 clones that exhibit both robust growth and radiation sensitivity following desiccation. The identification and characterization of desiccation-tolerant strains will allow us to engineer a biological model that will be resilient in face of the challenges of the deep space environment, and will thus ensure the experimental success of future biosensor missions.

  1. Family-School Strategies for Responding to the Needs of Children Experiencing Chronic Stress

    Science.gov (United States)

    Swick, Kevin J.; Knopf, Herman; Williams, Reginald; Fields, M. Evelyn

    2013-01-01

    Children experience chronic stress in ways that can impair their brain functioning and overall development. This article articulates the unique needs of children experiencing chronic stress and discusses strategies that families and schools can use to support and strengthen children's development across the social, emotional, and cognitive domains.

  2. Having your cake and eating it too: a habit of comfort food may link chronic social stress exposure and acute stress-induced cortisol hyporesponsiveness.

    Science.gov (United States)

    Tryon, M S; DeCant, Rashel; Laugero, K D

    2013-04-10

    Stress has been tied to changes in eating behavior and food choice. Previous studies in rodents have shown that chronic stress increases palatable food intake which, in turn, increases visceral fat and inhibits acute stress-induced hypothalamic-pituitary-adrenal (HPA) axis activity. The effect of chronic stress on eating behavior in humans is less understood, but it may be linked to HPA responsivity. The purpose of this study was to investigate the influence of chronic social stress and acute stress reactivity on food choice and food intake. Forty-one women (BMI=25.9±5.1 kg/m(2), age range=41 to 52 years) were subjected to the Trier Social Stress Test or a control task (nature movie) to examine HPA responses to an acute laboratory stressor and then invited to eat from a buffet containing low- and high-calorie snacks. Women were also categorized as high chronic stress or low chronic stress based on Wheaton Chronic Stress Inventory scores. Women reporting higher chronic stress and exhibiting low cortisol reactivity to the acute stress task consumed significantly more calories from chocolate cake on both stress and control visits. Chronic stress in the low cortisol reactor group was also positively related to total fat mass, body fat percentage, and stress-induced negative mood. Further, women reporting high chronic stress consumed significantly less vegetables, but only in those aged 45 years and older. Chronic stress in women within the higher age category was positively related to total calories consumed at the buffet, stress-induced negative mood and food craving. Our results suggest an increased risk for stress eating in persons with a specific chronic stress signature and imply that a habit of comfort food may link chronic social stress and acute stress-induced cortisol hyporesponsiveness. Published by Elsevier Inc.

  3. Age-dependent effects of chronic stress on ACTH and corticosterone responses to an acute novel stress.

    Science.gov (United States)

    Brodish, A; Odio, M

    1989-05-01

    Aging effects on the hypothalamic-pituitary-adrenocortical system have been studied primarily in the sedentary, environmentally deprived laboratory rat. Since it is known that chronic activation changes the responsiveness of the hypothalamic-pituitary-adrenocortical system, the present experiments were undertaken to determine whether age-related effects on this system would differ between sedentary and chronically stressed rats. Groups of 6- and 20-month-old F-344 rats were exposed to daily sessions of a 2-way shock-escape procedure over a 6-month period. When the rats were 12 (adult) and 26 months of age (old), pituitary-adrenocortical responses to an acute, novel stimulus were examined in young and old chronically stressed and age-matched control rats. Young and old control rats showed essentially the same corticosterone response to an acute motion stress. Chronic stress exposure increased the corticosterone response to the novel acute stressor in young but not in old rats. ACTH levels in response to acute stress were significantly reduced in old control rats compared to young control animals. Chronic stress did not change the ACTH acute stress response in young animals, whereas in old animals chronic stress elevated the ACTH responsiveness so that the old rats showed stress-induced ACTH levels that were comparable to the young animals. In conclusion, the effects of chronic stress on the function of the hypothalamic-pituitary-adrenocortical system are age-dependent, and environmental factors can significantly influence the progression of aging of the hypothalamic-pituitary-adrenal system.

  4. Chronic stress experience in young physicians: impact of person- and workplace-related factors.

    Science.gov (United States)

    Buddeberg-Fischer, Barbara; Stamm, Martina; Buddeberg, Claus; Klaghofer, Richard

    2010-04-01

    The objectives of the present study are to investigate and compare the relative impact of workplace-related factors and personal characteristics on chronic psychosocial stress experience in young physicians. In a prospective study, a cohort of Swiss medical school graduates was followed up, beginning in 2001. In their fourth and eighth year after graduation, 443 physicians assessed their workplace conditions, the experienced effort-reward imbalance, the received professional and emotional support as well as their personal characteristics. The chronic stress experience was measured by the Trier Inventory for the Assessment of Chronic Stress-Screening Subscale of Chronic Stress (TICS-SCSS), 7 years after graduation. The model of influencing factors on chronic stress experience was tested with a hierarchical regression analysis. The mean in chronic stress (TICS-SCSS) in our study sample is significantly higher (p stress, the workplace-related factor effort-reward imbalance as well as the personal characteristic overcommitment turned out to be the most important risk factors. Stress protective are high satisfaction with career support, sense of coherence and occupational self-efficacy. The whole set of variables used in the regression model explains 51% of the variance of chronic stress experience. In the prediction of chronic stress, gender has no significant moderator effect. It is a matter of concern that young physicians report to feel chronically stressed early in their professional career. Actions have to be taken to reduce the stress level mainly in regard to re-establish reciprocity between perceived effort invested and rewards received, in the form of esteem, monetary gain and career opportunities including job security.

  5. Hypercaloric diet modulates effects of chronic stress: a behavioral and biometric study on rats.

    Science.gov (United States)

    Oliveira, Carla de; Oliveira, Cleverson Moraes de; de Macedo, Isabel Cristina; Quevedo, Alexandre S; Filho, Paulo Ricardo Marques; Silva, Fernanda Ribeiro da; Vercelino, Rafael; de Souza, Izabel C Custodio; Caumo, Wolnei; Torres, Iraci L S

    2015-01-01

    Obesity is a chronic disease that has been associated with chronic stress and hypercaloric diet (HD) consumption. Increased ingestion of food containing sugar and fat ingredients (comfort food) is proposed to "compensate" chronic stress effects. However, this eating habit may increase body fat depositions leading to obesity. This study evaluated behavioral/physiological parameters seeking to establish whether there is an association between the effects of HD intake and stress, and to test the hypothesis that the development of anxious behavior and obesity during chronic stress periods depends on the type of diet. Sixty-day-old male Wistar rats (n = 100) were divided into four groups: standard chow, hypercaloric diet, chronic stress/standard chow and chronic stress/hypercaloric diet. Chronic stress was induced by restraint stress exposure for 1 h/day, for 80 d. At the end of this period, rat behavior was evaluated using open-field and plus-maze tests. The results showed that HD alone increased weight gain and adipose deposition in subcutaneous and mesenteric areas. However, stress reduced weight gain and adipose tissue in these areas. HD also increased naso-anal length and concurrent stress prevented this. Behavioral data indicated that stress increased anxiety-like behaviors and comfort food reduced these anxiogenic effects; locomotor activity increased in rats fed with HD. Furthermore, HD decreased corticosterone levels and stress increased adrenal weight. The data indicate that when rats are given HD and experience chronic stress this association reduces the pro-obesogenic effects of HD, and decreases adrenocortical activity.

  6. Salinity effects on the dynamics and patterns of desiccation cracks

    Science.gov (United States)

    Shokri, N.; Zhou, P.

    2012-12-01

    Cracking arising from desiccation is a ubiquitous phenomenon encountered in various industrial and geo-environmental applications including drying of clayey soil, cement, ceramics, gels, and many more colloidal suspensions. Presence of cracks in muddy sediments modifies the characteristics of the medium such as pore structure, porosity, and permeability which in turn influence various flow and transport processes. Thus it remains a topic of great interest in many disciplines to describe the dynamics of desiccation cracking under various boundary conditions. To this end, we conducted a comprehensive study to investigate effects of NaCl concentrations on cracking dynamics and patterns during desiccation of Bentonite. Mixtures of Bentonite and NaCl solutions were prepared with NaCl concentration varying from 2 to 10 percent in 0.5 percent increment (totally 17 configurations). The slurry was placed in a Petri dish mounted on a digital balance to record the evaporation dynamics. The atmospheric conditions were kept constant using an environmental chamber. An automatic camera was used to record the dynamics of macro-cracks (mm scale) at the surface of desiccating clay each minute. The obtained results illustrate the significant effects of salt concentration on the initiation, propagation, morphology and general dynamics of macro-cracks. We found that higher salt concentrations results in larger macro cracks' lengths attributed to the effects of NaCl on compressing the electric double layer of particles at increasing electrolyte concentrations which reduce considerably the repulsive forces among the particles and causing instability of the slurry and flocculation of the colloidal particles. Rheological measurements by means of a stress controlled rheometer revealed that the yield stress of the slurry decreases as NaCl concentration increases which may indicate aggregation of larger units in the slurry as a result of flocculation causing larger cracks' lengths due to

  7. The theory of chronic stress as a scientific model in Cognitive Neuroscience

    OpenAIRE

    Moscoso, Manolete; University of South Florida, Tampa Bay; Delgado, Eliana; Universidad Nacional Mayor de San Marcos

    2016-01-01

    The scientific study of stress presents serious conceptual and methodological limitations. The theory and concepts of allostasis and allostasis load allowed a new integrative framework of the concept of chronic stress, that identifies the brain as the mediator of the interactions among the central nervous system and immune system in the development of disease. We examined the negative impact of chronic stress and the perceived emotional distress on illness. Our research on the Mindfulness Bas...

  8. Behavioral effects of chronic adolescent stress are sustained and sexually dimorphic

    Science.gov (United States)

    Bourke, Chase H.; Neigh, Gretchen N.

    2011-01-01

    Evidence suggests that women are more susceptible to stress-related disorders than men. Animal studies demonstrate a similar female sensitivity to stress and have been used to examine the underlying neurobiology of sex-specific effects of stress. Although our understanding of the sex-specific effects of chronic adolescent stress has grown in recent years, few studies have reported the effects of adolescent stress on depressive-like behavior. The purpose of this study was to determine if a chronic mixed modality stressor (consisting of isolation, restraint, and social defeat) during adolescence (PND37-49) resulted in differential and sustained changes in depressive-like behavior in male and female Wistar rats. Female rats exposed to chronic adolescent stress displayed decreased sucrose consumption, hyperactivity in the elevated plus maze, decreased activity in the forced swim test, and a blunted corticosterone response to an acute forced swim stress compared to controls during both adolescence (PND48-57) and adulthood (PND96-104). Male rats exposed to chronic adolescent stress did not manifest significant behavioral changes at either the end of adolescence or in adulthood. These data support the proposition that adolescence may be a stress sensitive period for females and exposure to stress during adolescence results in behavioral effects that persist in females. Studies investigating the sex-specific effects of chronic adolescent stress may lead to a better understanding of the sexually dimorphic incidence of depressive and anxiety disorders in humans and ultimately improve prevention and treatment strategies. PMID:21466807

  9. Peripheral markers of oxidative stress in chronic mercuric chloride intoxication

    Directory of Open Access Journals (Sweden)

    Gutierrez L.L.P.

    2006-01-01

    Full Text Available The present study was designed to evaluate the time course changes in peripheral markers of oxidative stress in a chronic HgCl2 intoxication model. Twenty male adult Wistar rats were treated subcutaneously daily for 30 days and divided into two groups of 10 animals each: Hg, which received HgCl2 (0.16 mg kg-1 day-1, and control, receiving the same volume of saline solution. Blood was collected at the first, second and fourth weeks of Hg administration to evaluate lipid peroxidation (LPO, total radical trapping antioxidant potential (TRAP, and superoxide dismutase (Cu,Zn-SOD, glutathione peroxidase (GPx, glutathione-S-transferase (GST, and catalase (CAT. HgCl2 administration induced a rise (by 26% in LPO compared to control (143 ± 10 cps/mg hemoglobin in the second week and no difference was found at the end of the treatment. At that time, GST and GPx were higher (14 and 24%, respectively in the Hg group, and Cu,Zn-SOD was lower (54% compared to control. At the end of the treatment, Cu,Zn-SOD and CAT were higher (43 and 10%, respectively in the Hg group compared to control (4.6 ± 0.3 U/mg protein; 37 ± 0.9 pmol/mg protein, respectively. TRAP was lower (69% in the first week compared to control (43.8 ± 1.9 mM Trolox. These data provide evidence that HgCl2 administration is accompanied by systemic oxidative damage in the initial phase of the process, which leads to adaptive changes in the antioxidant reserve, thus decreasing the oxidative injury at the end of 30 days of HgCl2 administration. These results suggest that a preventive treatment with antioxidants would help to avoid oxidative damage in subjects with chronic intoxication.

  10. Chronic obstructive lung disease and posttraumatic stress disorder: current perspectives

    Directory of Open Access Journals (Sweden)

    Abrams TE

    2015-10-01

    Full Text Available Thad E Abrams,1,2 Amy Blevins,1,3 Mark W Vander Weg1,2,4 1Department of Internal Medicine, University of Iowa, 2Center for Comprehensive Access and Delivery Research and Evaluation, Iowa City VA Health Care System, 3Hardin Health Sciences Library, 4Department of Psychological and Brain Sciences, University of Iowa, Iowa City, IA, USA Background: Several studies have reported on the co-occurrence of chronic obstructive pulmonary disease (COPD and psychiatric conditions, with the most robust evidence base demonstrating an impact of comorbid anxiety and depression on COPD-related outcomes. In recent years, research has sought to determine if there is a co-occurrence between COPD and posttraumatic stress disorder (PTSD as well as for associations between PTSD and COPD-related outcomes. To date, there have been no published reviews summarizing this emerging literature.Objectives: The primary objective of this review was to determine if there is adequate evidence to support a co-occurrence between PTSD and COPD. Secondary objectives were to: 1 determine if there are important clinical considerations regarding the impact of PTSD on COPD management, and 2 identify targeted areas for further research.Methods: A structured review was performed using a systematic search strategy limited to studies in English, addressing adults, and to articles that examined: 1 the co-occurrence of COPD and PTSD and 2 the impact of PTSD on COPD-related outcomes. To be included, articles must have addressed some type of nonreversible obstructive lung pathology.Results: A total of 598 articles were identified for initial review. Upon applying the inclusion and exclusion criteria, n=19 articles or abstracts addressed our stated objectives. Overall, there is inconclusive evidence to support the co-occurrence between PTSD and COPD. Studies finding a significant co-occurrence generally had inferior methods of identifying COPD; in contrast, studies that utilized more robust COPD

  11. Surviving metabolic arrest: photosynthesis during desiccation and rehydration in resurrection plants.

    Science.gov (United States)

    Challabathula, Dinakar; Puthur, Jos T; Bartels, Dorothea

    2016-02-01

    Photosynthesis is the key process that is affected by dehydration in plants. Desiccation-tolerant resurrection plants can survive conditions of very low relative water content. During desiccation, photosynthesis is not operational, but is recovered within a short period after rehydration. While homoiochlorophyllous resurrection plants retain their photosynthetic apparatus during desiccation, poikilochlorophyllous resurrection species dismantle chloroplasts and degrade chlorophyll but resynthesize them again during rehydration. Dismantling the chloroplasts avoids the photooxidative stress in poikilochlorophyllous resurrection plants, whereas it is minimized in homoiochlorophyllous plants through the synthesis of antioxidant enzymes and protective proteins or metabolites. Although the cellular protection mechanisms in both of these species vary, these mechanisms protect cells from desiccation-induced damage and restore photosynthesis upon rehydration. Several of the proteins synthesized during dehydration are localized in chloroplasts and are believed to play major roles in the protection of photosynthetic structures and in recovery in resurrection species. This review focuses on the strategies of resurrection plants in terms of how they protect their photosynthetic apparatus from oxidative stress during desiccation without membrane damage and with full recovery during rehydration. We review the role of the dehydration-induced protection mechanisms in chloroplasts and how photosynthesis is restored during rehydration. © 2015 New York Academy of Sciences.

  12. Reboxetine Improves Auditory Attention and Increases Norepinephrine Levels in the Auditory Cortex of Chronically Stressed Rats.

    Science.gov (United States)

    Pérez-Valenzuela, Catherine; Gárate-Pérez, Macarena F; Sotomayor-Zárate, Ramón; Delano, Paul H; Dagnino-Subiabre, Alexies

    2016-01-01

    Chronic stress impairs auditory attention in rats and monoamines regulate neurotransmission in the primary auditory cortex (A1), a brain area that modulates auditory attention. In this context, we hypothesized that norepinephrine (NE) levels in A1 correlate with the auditory attention performance of chronically stressed rats. The first objective of this research was to evaluate whether chronic stress affects monoamines levels in A1. Male Sprague-Dawley rats were subjected to chronic stress (restraint stress) and monoamines levels were measured by high performance liquid chromatographer (HPLC)-electrochemical detection. Chronically stressed rats had lower levels of NE in A1 than did controls, while chronic stress did not affect serotonin (5-HT) and dopamine (DA) levels. The second aim was to determine the effects of reboxetine (a selective inhibitor of NE reuptake) on auditory attention and NE levels in A1. Rats were trained to discriminate between two tones of different frequencies in a two-alternative choice task (2-ACT), a behavioral paradigm to study auditory attention in rats. Trained animals that reached a performance of ≥80% correct trials in the 2-ACT were randomly assigned to control and stress experimental groups. To analyze the effects of chronic stress on the auditory task, trained rats of both groups were subjected to 50 2-ACT trials 1 day before and 1 day after of the chronic stress period. A difference score (DS) was determined by subtracting the number of correct trials after the chronic stress protocol from those before. An unexpected result was that vehicle-treated control rats and vehicle-treated chronically stressed rats had similar performances in the attentional task, suggesting that repeated injections with vehicle were stressful for control animals and deteriorated their auditory attention. In this regard, both auditory attention and NE levels in A1 were higher in chronically stressed rats treated with reboxetine than in vehicle

  13. High radiation and desiccation tolerance of nitrogen-fixing cultures of the cyanobacterium Anabaena sp. strain PCC 7120 emanates from genome/proteome repair capabilities.

    Science.gov (United States)

    Singh, Harinder; Anurag, Kirti; Apte, Shree Kumar

    2013-10-12

    The filamentous nitrogen-fixing cyanobacterium, Anabaena sp. strain PCC 7120 was found to tolerate very high doses of 60 Co-gamma radiation or prolonged desiccation. Post-stress, cells remained intact and revived all the vital functions. A remarkable capacity to repair highly disintegrated genome and recycle the damaged proteome appeared to underlie such high radioresistance and desiccation tolerance. The close similarity observed between the cellular response to irradiation or desiccation stress lends strong support to the notion that tolerance to these stresses may involve similar mechanisms.

  14. Is the Thoroughbred race-horse under chronic stress?

    Directory of Open Access Journals (Sweden)

    Nogueira G.P.

    1997-01-01

    Full Text Available Thoroughbred fillies were divided into three groups according to age: group 1, 7 fillies aged 1 to 2 years (G1 starting the training program; group 2, 9 fillies aged 2 to 3 years (G2 in a full training program; group 3, 8 older fillies 3 to 4 years of age (G3 training and racing. Blood samples were collected weekly from July to December. Cortisol was quantified using a solid phase DPC kit. The intra- and interassay coefficients of variation were 12.5% and 15.65% and sensitivity was 1.9 ± 0.2 nmol/l. The semester average of cortisol levels varied between groups: G1 = 148.8 ± 6.7, G2 = 125.7 ± 5.8, G3 = 101.1 ± 5.4 nmol/l, with G3 differing statistically from the other groups. The lower cortisol levels observed in the older fillies lead us to propose that the stress stimulus, when maintained over a long period of time, may become chronic and result in a reduction of hypophyseal corticotropin-releasing hormone receptors. The secretion of endogenous opioids may also lead to low serum cortisol levels.

  15. Effects of chronic stress on in vivo pituitary-adrenocortical responses to corticotropin releasing hormone.

    Science.gov (United States)

    Odio, M R; Brodish, A

    1990-03-01

    Experimental evidence indicates that animals exposed to chronic stress demonstrate increased adrenocorticotropin (ACTH) and corticosterone (CORT) responses to novel stimuli (facilitation) but attenuated ACTH and CORT responses to the chronic stressor (adaptation). The mechanisms responsible for facilitation and adaptation of ACTH and CORT responses are not known. In the present experiments, we chronically exposed male Fischer-344 rats to sessions of a two-way shock-escape stress procedure following a schedule which we had previously shown to elicit adaptation of ACTH and CORT responses. To determine if pituitary-adrenocortical adaptation to stress was mediated by alterations in pituitary responsiveness to corticotropin-releasing hormone (CRH), control and chronically stressed rats received intra-arterial injections of a low and a high dose of CRH and blood samples from each animal were assayed for ACTH and CORT levels. The results showed that ACTH responses to the low (but not the high) dose of CRH were attenuated by chronic stress. In addition we confirmed previous reports which showed that chronic stress increased adrenocortical sensitivity to ACTH. Thus, we concluded that adaptation of ACTH responses to chronic stress may be in part mediated by a reduction of the CRH-induced ACTH secretory response.

  16. History of chronic stress modifies acute stress-evoked fear memory and acoustic startle in male rats.

    Science.gov (United States)

    Schmeltzer, Sarah N; Vollmer, Lauren L; Rush, Jennifer E; Weinert, Mychal; Dolgas, Charles M; Sah, Renu

    2015-01-01

    Chronicity of trauma exposure plays an important role in the pathophysiology of posttraumatic stress disorder (PTSD). Thus, exposure to multiple traumas on a chronic scale leads to worse outcomes than acute events. The rationale for the current study was to investigate the effects of a single adverse event versus the same event on a background of chronic stress. We hypothesized that a history of chronic stress would lead to worse behavioral outcomes than a single event alone. Male rats (n = 14/group) were exposed to either a single traumatic event in the form of electric foot shocks (acute shock, AS), or to footshocks on a background of chronic stress (chronic variable stress-shock, CVS-S). PTSD-relevant behaviors (fear memory and acoustic startle responses) were measured following 7 d recovery. In line with our hypothesis, CVS-S elicited significant increases in fear acquisition and conditioning versus the AS group. Unexpectedly, CVS-S elicited reduced startle reactivity to an acoustic stimulus in comparison with the AS group. Significant increase in FosB/ΔFosB-like immunostaining was observed in the dentate gyrus, basolateral amygdala and medial prefrontal cortex of CVS-S rats. Assessments of neuropeptide Y (NPY), a stress-regulatory transmitter associated with chronic PTSD, revealed selective reduction in the hippocampus of CVS-S rats. Collectively, our data show that cumulative stress potentiates delayed fear memory and impacts defensive responding. Altered neuronal activation in forebrain limbic regions and reduced NPY may contribute to these phenomena. Our preclinical studies support clinical findings reporting worse PTSD outcomes stemming from cumulative traumatization in contrast to acute trauma.

  17. Chronic Stress Impairs Prefrontal Cortex-Dependent Response Inhibition and Spatial Working Memory

    Science.gov (United States)

    Mika, Agnieszka; Mazur, Gabriel J.; Hoffman, Ann N.; Talboom, Joshua S.; Bimonte-Nelson, Heather A.; Sanabria, Federico; Conrad, Cheryl D.

    2012-01-01

    Chronic stress leads to neurochemical and structural alterations in the prefrontal cortex (PFC) that correspond to deficits in PFC-mediated behaviors. The present study examined the effects of chronic restraint stress on response inhibition (using a response-withholding task, fixed-minimum interval schedule of reinforcement, or FMI), and working memory (using a radial arm water maze, RAWM). Adult male Sprague Dawley rats were first trained on the RAWM and subsequently trained on FMI. Following acquisition of FMI, rats were assigned to a restraint stress (6h/d/28d in wire mesh restrainers) or control condition. Immediately after chronic stress, rats were tested on FMI and subsequently on RAWM. FMI results suggest that chronic stress reduces response inhibition capacity and motivation to initiate the task on selective conditions when food reward was not obtained on the preceding trial. RAWM results suggest that chronic stress produces transient deficits in working memory without altering previously consolidated reference memory. Behavioral measures from FMI failed to correlate with metrics from RAWM except for one in which changes in FMI timing precision negatively correlated with changes in RAWM working memory errors for the controls, a finding that was not observed following chronic stress. Fisher’s r to z transformation revealed no significant differences between control and stress with correlation coefficients. These findings are the first to show that chronic stress impairs both response inhibition and working memory, two behaviors that have never been direct compared within the same animals following chronic stress, using FMI, an appetitive task, and RAWM, a non-appetitive task. PMID:22905921

  18. Effects of a chronic stress treatment on vaccinal response in lambs.

    Science.gov (United States)

    Destrez, A; Boissy, A; Guilloteau, L; Andanson, S; Souriau, A; Laroucau, K; Chaillou, E; Deiss, V

    2017-05-01

    Farming systems can expose animals to chronic mild stress which is known to induce negative affective state. Affective state in animals, as in humans, can be assessed through behavioral cues. This study aimed to describe the effect of a chronic mild stress, known to induce a negative affective state, on sheep health through their response to vaccination. The study used 15 lambs subjected to a model of chronic mild stress for 15 weeks and 15 lambs reared under conventional farming as a control group. After 7 weeks of stressful treatment, the lambs were individually exposed to a judgment bias test to assess a putative stress-induced 'pessimism.' After 15 weeks of stressful treatment, antibody immune response was measured after an injection of a live vaccine challenge (Chlamydia abortus attenuated vaccine strain 1B). Stressed lambs displayed a pessimistic-like perception in the judgment bias test, revealing a negative affective state. Stressed and control animals showed different immunological reactions to vaccine challenge: stressed sheep had lower hemoglobin concentrations and higher platelet, granulocyte and acute-phase protein concentrations. Antibody response induced by the vaccine strain was not different between stressed and control sheep. Our results suggest that negative affective state induced by chronic stress treatment may induce a stronger inflammatory response to vaccine challenge in sheep. Improvement of animal health may be achieved through consideration of stressors that may affect the emotional and immunological state of sheep.

  19. Differential effects of mild chronic stress on cortisol and S-IgA responses to an acute stressor.

    Science.gov (United States)

    Viena, Tatiana D; Banks, Jonathan B; Barbu, Isabelle M; Schulman, Allan H; Tartar, Jaime L

    2012-10-01

    While acute stress is adaptive in the short term, chronic stress may interfere with HPA axis functioning and self-regulation that can, in turn, alter the body's immune response. Several studies suggest that acute and chronic stress consistently increase cortisol levels; however, the same cannot be said about S-IgA levels. We tested the effects of a mild chronic stress (an academic exam period), on cortisol and S-IgA responses to an acute stress. Exposure to an acute stressor significantly increases cortisol levels during periods of no-stress, but not during mild chronic stress, while S-IgA levels consistently increase during both sessions. Furthermore, we find that during the period of chronic mild stress, the perception of stress is related to increased cortisol response to an acute stressor. Combined, these findings shed light on the impact of increased background stress on acute stress responses. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Glucoregulatory responses of adult and aged rats after exposure to chronic stress.

    Science.gov (United States)

    Odio, M R; Brodish, A

    1990-01-01

    Stress has been implicated as an environmental factor that may accelerate the process of biological aging. However, this proposal has remained largely anecdotal due to relatively few studies that directly tested this hypothesis. In the present experiments groups of 6-month-old and 20-month-old male F-344 rats were chronically stressed for a six-month period. After the last stress session, when the animals were 12 months of age (adult) and 26 months of age (old), control and chronically stressed rats were tested for their ability to: (a) elicit glucose and insulin responses to an acute, novel stressor; (b) remove a circulatory glucose load elicited either by acute stress exposure or by injection of d-glucose; and (c) raise insulin levels after a glucose challenge. In control rats, we observed a deficit in each of these parameters in old compared to adult rats. Exposure to chronic stress did not exacerbate deterioration of these response mechanisms in either adult or old rats. In fact, the data showed a modest improvement in glucose tolerance in chronically stressed compared to age-matched control rats. We conclude that chronic stress did not exacerbate age-dependent decline of glucoregulatory capacity. From these results and from our earlier work, we speculate that the decline during aging of the functional integrity of systems involved in the response to stress may be sustained by periodic challenges from the organism's external environment.

  1. Desiccation resistance: effect of cuticular hydrocarbons and water content in Drosophila melanogaster adults

    Directory of Open Access Journals (Sweden)

    Jean-Francois Ferveur

    2018-02-01

    Full Text Available Background The insect cuticle covers the whole body and all appendages and has bi-directionnal selective permeability: it protects against environmental stress and pathogen infection and also helps to reduce water loss. The adult cuticle is often associated with a superficial layer of fatty acid-derived molecules such as waxes and long chain hydrocarbons that prevent rapid dehydration. The waterproofing properties of cuticular hydrocarbons (CHs depend on their chain length and desaturation number. Drosophila CH biosynthesis involves an enzymatic pathway including several elongase and desaturase enzymes. Methods The link between desiccation resistance and CH profile remains unclear, so we tested (1 experimentally selected desiccation-resistant lines, (2 transgenic flies with altered desaturase expression and (3 natural and laboratory-induced CH variants. We also explored the possible relationship between desiccation resistance, relative water content and fecundity in females. Results We found that increased desiccation resistance is linked with the increased proportion of desaturated CHs, but not with their total amount. Experimentally-induced desiccation resistance and CH variation both remained stable after many generations without selection. Conversely, flies with a higher water content and a lower proportion of desaturated CHs showed reduced desiccation resistance. This was also the case in flies with defective desaturase expression in the fat body. Discussion We conclude that rapidly acquired desiccation resistance, depending on both CH profile and water content, can remain stable without selection in a humid environment. These three phenotypes, which might be expected to show a simple relationship, turn out to have complex physiological and genetic links.

  2. Diffusion-weighted MRI and quantitative biophysical modeling of hippocampal neurite loss in chronic stress.

    Directory of Open Access Journals (Sweden)

    Peter Vestergaard-Poulsen

    Full Text Available Chronic stress has detrimental effects on physiology, learning and memory and is involved in the development of anxiety and depressive disorders. Besides changes in synaptic formation and neurogenesis, chronic stress also induces dendritic remodeling in the hippocampus, amygdala and the prefrontal cortex. Investigations of dendritic remodeling during development and treatment of stress are currently limited by the invasive nature of histological and stereological methods. Here we show that high field diffusion-weighted MRI combined with quantitative biophysical modeling of the hippocampal dendritic loss in 21 day restraint stressed rats highly correlates with former histological findings. Our study strongly indicates that diffusion-weighted MRI is sensitive to regional dendritic loss and thus a promising candidate for non-invasive studies of dendritic plasticity in chronic stress and stress-related disorders.

  3. The effects of chronic social defeat stress on mouse self-grooming behavior and its patterning.

    Science.gov (United States)

    Denmark, Ashley; Tien, David; Wong, Keith; Chung, Amanda; Cachat, Jonathan; Goodspeed, Jason; Grimes, Chelsea; Elegante, Marco; Suciu, Christopher; Elkhayat, Salem; Bartels, Brett; Jackson, Andrew; Rosenberg, Michael; Chung, Kyung Min; Badani, Hussain; Kadri, Ferdous; Roy, Sudipta; Tan, Julia; Gaikwad, Siddharth; Stewart, Adam; Zapolsky, Ivan; Gilder, Thomas; Kalueff, Allan V

    2010-04-02

    Stress induced by social defeat is a strong modifier of animal anxiety and depression-like phenotypes. Self-grooming is a common rodent behavior, and has an ordered cephalo-caudal progression from licking of the paws to head, body, genitals and tail. Acute stress is known to alter grooming activity levels and disrupt its patterning. Following 15-17 days of chronic social defeat stress, grooming behavior was analyzed in adult male C57BL/6J mice exhibiting either dominant or subordinate behavior. Our study showed that subordinate mice experience higher levels of anxiety and display disorganized patterning of their grooming behaviors, which emerges as a behavioral marker of chronic social stress. These findings indicate that chronic social stress modulates grooming behavior in mice, thus illustrating the importance of grooming phenotypes for neurobehavioral stress research. Copyright 2010 Elsevier B.V. All rights reserved.

  4. Effects of age on metabolic responses to acute and chronic stress.

    Science.gov (United States)

    Odio, M R; Brodish, A

    1988-05-01

    The effect of age on the capacity of an organism to mobilize glucose and free fatty acids during stress and to adapt these responses from an acute to a chronic stress situation is not known. The purpose of this study was to determine whether aging impaired the capacity to 1) raise glucose and free fatty acid levels and suppress insulin release in acute stress situations and 2) develop adaptation of these responses to exposure to chronic stress. Our results indicate that 6-mo-old rats (young) trained to escape electric shock (short-term modulation) showed greater acute stress-induced hyperglycemic, hypoinsulinemic, and lipolytic responses than untrained young rats. By contrast, in 22-mo-old rats (old), responses of trained and untrained animals were not different. In the chronic stress (long-term adaptation) experiments, it was found that 1) adaptation of stress-induced hyperglycemia occurred at a faster rate in young than in old animals; 2) in young but not in aged rats, a strong positive correlation was observed between adaptation of stress-induced hyperglycemia and hypoinsulinemia; and 3) in young rats, stress-induced lipolytic responses declined proportionately to the duration of chronic stress exposure, whereas by contrast in chronically stressed aged rats steady-state levels of free fatty acids were not raised during exposure to stress. Thus we conclude that 1) glucose intolerance may play a key role in the altered stress-induced metabolic responses of aged rats; 2) with age, there is a loss of plasticity in physiological adaptive response mechanisms associated with metabolic responses to stress.

  5. [Coping with chronic somatic disease according to the concept of psychological stress].

    Science.gov (United States)

    Miniszewska, Joanna; Chodkiewicz, Jan

    2013-01-01

    The article presents the problem of coping with chronic disease according to the concept of psychological stress. The Lazarus and Folkman theory in which stress is regarded as a relational concept, the importance of cognitive assessment and functions of coping with disease are described. The attention is paid to the illness perception and its impact on the behavioral and emotional processes. The most known tools for stress assessment and coping with stress and current research directions are shown.

  6. Variation in adult life history and stress resistance across five ...

    Indian Academy of Sciences (India)

    Unknown

    Dry weight at eclosion, adult lifespan, lifetime fecundity, lipid and carbohydrate content at eclosion, and starvation and desiccation ... Keywords. life-history evolution; lifespan; fecundity; starvation; desiccation; lipid; glycogen; sexual dimorphism; laboratory ...... Rapid loss of stress resistance in Drosophila melanogaster.

  7. Mental Strain and Chronic Stress among University Students with Symptoms of Irritable Bowel Syndrome

    Directory of Open Access Journals (Sweden)

    Marco D. Gulewitsch

    2013-01-01

    Full Text Available Aim. To investigate the degree of mental strain and chronic stress in a German community sample of students with IBS-like symptoms. Methods and Materials. Following an internet-based survey about stress, this study recruited 176 German university students (23.45±2.48 years; 48.3% males with IBS-like symptoms according to Rome III and 181 students without IBS (23.55±2.82 years; 50.3% males and compared them regarding current mental strain (SCL-90-R and the extend of chronic stress. Beyond this, IBS subtypes, IBS severity, and health care utilization were assessed. Results. Students fulfilling IBS criteria showed significantly elevated values of mental strain and chronic stress. Nearly 40% of the IBS group (versus 20% of the controls reached a clinically relevant value on the SCL-90-R global severity scale. IBS subtypes did not differ in terms of mental distress or chronic stress. Somatization, anxiety, and the chronic stressors “work overload,” “social tension,” and “dissatisfaction with job” were most closely connected to IBS symptom severity. Regarding health care utilization, our results show that consulting a physician frequently was not associated significantly with elevated mental strain or chronic stress but with IBS symptom severity. Conclusion. Our data contribute additional evidence to the distinct association between psychological stress and IBS in community samples.

  8. Depressive symptoms and perceived chronic stress predict test anxiety in nursing students

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    Christoph Augner

    2015-09-01

    Full Text Available Aim: The aim of this study is to identify predictors of test anxiety in nursing students. Design: Cross sectional pilot study. Methods: A questionnaire was administered to 112 students of an Austrian nursing school (mean age = 21.42, SD = 5.21. Test anxiety (measured by the standardized PAF Test Anxiety Questionnaire, perceived chronic stress, depressive symptoms, pathological eating and further psychological and health parameters were measured. Results: We found highly significant correlations between test anxiety and working hours (0.25, depression score (0.52, emotional stability (-0.31, and perceived chronic stress (0.65 (p < 0.01, for all. Regression analysis revealed chronic stress and emotional instability as best predictors for test anxiety. Furthermore, path analysis revealed that past negative academic performance outcomes contribute to test anxiety via depressive symptoms and perceived chronic stress. Conclusion: Depressive symptoms and perceived chronic stress are strongly related to test anxiety. Therefore therapy and training methods that address depressive symptoms and perceived chronic stress, and thereby aim to modify appraisal of potential stressful situations, may be successful in addressing test anxiety.

  9. Variable impact of chronic stress on spatial learning and memory in BXD mice.

    Science.gov (United States)

    Shea, Chloe J A; Carhuatanta, Kimberly A K; Wagner, Jessica; Bechmann, Naomi; Moore, Raquel; Herman, James P; Jankord, Ryan

    2015-10-15

    The effects of chronic stress on learning are highly variable across individuals. This variability stems from gene-environment interactions. However, the mechanisms by which stress affects genetic predictors of learning are unclear. Thus, we aim to determine whether the genetic pathways that predict spatial memory performance are altered by previous exposure to chronic stress. Sixty-two BXD recombinant inbred strains of mice, as well as parent strains C57BL/6J and DBA/2J, were randomly assigned as behavioral control or to a chronic variable stress paradigm and then underwent behavioral testing to assess spatial memory and learning performance using the Morris water maze. Quantitative trait loci (QTL) mapping was completed for average escape latency times for both control and stress animals. Loci on chromosomes 5 and 10 were found in both control and stress environmental populations; eight additional loci were found to be unique to either the control or stress environment. In sum, results indicate that certain genetic loci predict spatial memory performance regardless of prior stress exposure, while exposure to stress also reveals unique genetic predictors of training during the memory task. Thus, we find that genetic predictors contributing to spatial learning and memory are susceptible to the presence of chronic stress. Published by Elsevier Inc.

  10. Sex Differences and the Impact of Chronic Stress and Recovery on Instrumental Learning

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    Angela L. McDowell

    2015-01-01

    Full Text Available We have previously shown that 21-day chronic restraint stress impacts instrumental learning, but overall few studies have examined sex differences on the impact of stress on learning. We further examined sex differences in response to extended 42-day chronic stress on instrumental learning, as well as recovery from chronic stress. Rats were tested in aversive training tasks with or without prior appetitive experience, and daily body weight data was collected as an index of stress. Relative to control animals, reduced body weight was maintained from day 22 through day 42 across the stress period for males, but not for females. Stressed males had increased response speed and lower learning efficiency during appetitive acquisition and aversive learning. Males overall showed slower escape shaping times and more shock exposure. In contrast, stressed females showed slower appetitive response speeds and higher appetitive and aversive efficiency but overall reduced avoidance rates during acquisition and maintenance for transfer animals and during maintenance for aversive-only animals. These tasks reveal important nuances on the effect of stress on goal-directed behavior and further highlight sexually divergent effects on appetitive versus aversive motivation. Furthermore, these data underscore that systems are temporally impacted by chronic stress in a sexually divergent pattern.

  11. Chronic mild stress affects sucrose intake and sleep in rats.

    Science.gov (United States)

    Grønli, Janne; Murison, Robert; Bjorvatn, Bjørn; Sørensen, Eli; Portas, Chiara M; Ursin, Reidun

    2004-04-02

    Depression in humans is associated with sleep abnormalities of three types: altered rapid eye movement (REM) sleep, fragmented sleep, and reduced delta sleep. In an animal model of depression, chronic exposure to mild stressors (CMS, e.g. periods of soiled cage, reversed light/dark cycle, grouped housing, food and/or water deprivation) causes behavioral and hormonal changes which, in humans, often are associated with depression. In the CMS model, a reduced sucrose intake has been defined as one of the core symptoms of depression, anhedonia, although this finding is not consistent among various laboratories. In the present study, we investigated if the CMS procedure, in our laboratory, would cause decreased sucrose intake and, also, give sleep changes similar to what is found in depressed patients. Exposure to CMS decreased sucrose intake in our rats. The largest effect was obtained after 2 weeks of the stress protocol. CMS rats spent more time in REM sleep and showed more fragmented sleep compared to their baseline recording, while there were no changes in the control rats. Increased sleep fragmentation in CMS rats was particularly evident by increased number of arousals, and increased REM sleep and slow-wave-sleep-1 (SWS-1) episodes. The duration of sleep stage episodes was decreased. The amount of slow-wave-sleep-2 (SWS-2) was not decreased, however SWS-2 in percent of total SWS was reduced. Correlation analysis showed that animals that had less consumption of sucrose spent more time in REM sleep and had increased number of REM sleep episodes. In this study, CMS appears to be a model of depression.

  12. Adaptogenic potential of royal jelly in liver of rats exposed to chronic stress.

    Directory of Open Access Journals (Sweden)

    Douglas Carvalho Caixeta

    Full Text Available Restraint and cold stress increase both corticosterone and glycemia, which lead to oxidative damages in hepatic tissue. This study assessed the effect of royal jelly (RJ supplementation on the corticosterone level, glycemia, plasma enzymes and hepatic antioxidant system in restraint and cold stressed rats. Wistar rats were allocated into no-stress, stress, no-stress supplemented with RJ and stress supplemented with RJ groups. Initially, RJ (200mg/Kg was administered for fourteen days and stressed groups were submitted to chronic stress from the seventh day. The results showed that RJ supplementation decreases corticosterone levels and improves glycemia control after stress induction. RJ supplementation also decreased the body weight, AST, ALP and GGT. Moreover, RJ improved total antioxidant capacity, SOD activity and reduced GSH, GR and lipoperoxidation in the liver. Thus, RJ supplementation reestablished the corticosterone levels and the hepatic antioxidant system in stressed rats, indicating an adaptogenic and hepatoprotective potential of RJ.

  13. Desiccant-assisted cooling fundamentals and applications

    CERN Document Server

    Brum, Nisio

    2014-01-01

    The increasing concern with indoor air quality has led to air-quality standards with increased ventilation rates. Although increasing the volume flow rate of outside air is advisable from the perspective of air-quality, it is detrimental to energy consumption, since the outside air has to be brought to the comfort condition before it is insufflated to the  conditioned ambient. Moreover, the humidity load carried within outside air has challenging HVAC engineers to design cooling units which are able to satisfactorily handle both sensible and latent contributions to the thermal load. This constitutes a favorable scenario for the use of solid desiccants to assist the cooling units. In fact, desiccant wheels have been increasingly applied by HVAC designers, allowing distinct processes for the air cooling and dehumidification. In fact, the ability of solid desiccants in moisture removal is effective enough to allow the use of evaporative coolers, in opposition to the traditional vapor-compression cycle, resultin...

  14. Unpredictable chronic mild stress differentially impairs social and contextual discrimination learning in two inbred mouse strains.

    Directory of Open Access Journals (Sweden)

    Michiel van Boxelaere

    Full Text Available Alterations in the social and cognitive domain are considered important indicators for increased disability in many stress-related disorders. Similar impairments have been observed in rodents chronically exposed to stress, mimicking potential endophenotypes of stress-related psychopathologies such as major depression disorder (MDD, anxiety, conduct disorder, and posttraumatic stress disorder (PTSD. Data from numerous studies suggest that deficient plasticity mechanisms in hippocampus (HC and prefrontal cortex (PFC might underlie these social and cognitive deficits. Specifically, stress-induced deficiencies in neural plasticity have been associated with a hypodopaminergic state and reduced neural plasticity persistence. Here we assessed the effects of unpredictable chronic mild stress (UCMS on exploratory, social and cognitive behavior of females of two inbred mouse strains (C57BL/6J and DBA/2J that differ in their dopaminergic profile. Exposure to chronic stress resulted in impaired circadian rhythmicity, sociability and social cognition in both inbred strains, but differentially affected activity patterns and contextual discrimination performance. These stress-induced behavioral impairments were accompanied by reduced expression levels of brain derived neurotrophic factor (BDNF in the prefrontal cortex. The strain-specific cognitive impairment was coexistent with enhanced plasma corticosterone levels and reduced expression of genes related to dopamine signaling in hippocampus. These results underline the importance of assessing different strains with multiple test batteries to elucidate the neural and genetic basis of social and cognitive impairments related to chronic stress.

  15. Long-lasting delayed hyperalgesia after chronic restraint stress in rats-effect of morphine administration.

    Science.gov (United States)

    da Silva Torres, Iraci Lucena; Cucco, Simone N S; Bassani, Marcio; Duarte, Marcelo S; Silveira, Patricia P; Vasconcellos, Ana Paula; Tabajara, Angela Sampaio; Dantas, Giovana; Fontella, Fernanda U; Dalmaz, Carla; Ferreira, Maria Beatriz C

    2003-03-01

    Different effects upon the nociceptive response have been observed with exposure to acute and chronic stress in rats. In the present study we repeatedly submitted rats to restraint for 40 days, inducing hyperalgesia using the tail-flick test. A new session of acute stress was applied at the end of 40 days period, and the chronically-stressed animals demonstrated analgesia after forced swimming, but not after restraint. The effect of stress interruption for 14 or 28 days on the nociceptive threshold was then investigated. The basal tail-flick latency remained decreased for at least 28 days (hyperalgesic effect). Following the periods of suspension, the animals were submitted to new session of acute restraint, and stress-induced analgesia was observed only after 28 days of stress interruption. Thus, the mechanisms involved in the long-lasting hyperalgesia presented in this study are not exactly the same as those responsible for the analgesia induced by acute stressors. After 40 days of chronic stress treatment, morphine was injected i.p. (1.0, 5.0 mg/kg or saline). The repeatedly stressed rats displayed decreased morphine effects on nociception compared to unstressed controls. The tolerance of the response to morphine agrees with previous studies suggesting that chronic restraint stress could modify the activity of opioid systems.

  16. Unpredictable chronic mild stress differentially impairs social and contextual discrimination learning in two inbred mouse strains.

    Science.gov (United States)

    van Boxelaere, Michiel; Clements, Jason; Callaerts, Patrick; D'Hooge, Rudi; Callaerts-Vegh, Zsuzsanna

    2017-01-01

    Alterations in the social and cognitive domain are considered important indicators for increased disability in many stress-related disorders. Similar impairments have been observed in rodents chronically exposed to stress, mimicking potential endophenotypes of stress-related psychopathologies such as major depression disorder (MDD), anxiety, conduct disorder, and posttraumatic stress disorder (PTSD). Data from numerous studies suggest that deficient plasticity mechanisms in hippocampus (HC) and prefrontal cortex (PFC) might underlie these social and cognitive deficits. Specifically, stress-induced deficiencies in neural plasticity have been associated with a hypodopaminergic state and reduced neural plasticity persistence. Here we assessed the effects of unpredictable chronic mild stress (UCMS) on exploratory, social and cognitive behavior of females of two inbred mouse strains (C57BL/6J and DBA/2J) that differ in their dopaminergic profile. Exposure to chronic stress resulted in impaired circadian rhythmicity, sociability and social cognition in both inbred strains, but differentially affected activity patterns and contextual discrimination performance. These stress-induced behavioral impairments were accompanied by reduced expression levels of brain derived neurotrophic factor (BDNF) in the prefrontal cortex. The strain-specific cognitive impairment was coexistent with enhanced plasma corticosterone levels and reduced expression of genes related to dopamine signaling in hippocampus. These results underline the importance of assessing different strains with multiple test batteries to elucidate the neural and genetic basis of social and cognitive impairments related to chronic stress.

  17. The effects of acute and chronic stress on motor and sensory performance in male Lewis rats.

    Science.gov (United States)

    Metz, G A; Schwab, M E; Welzl, H

    2001-01-01

    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.

  18. Chronic Mild Prenatal Stress Exacerbates the Allergen-Induced Airway Inflammation in Rats

    Directory of Open Access Journals (Sweden)

    Paulo J. Nogueira

    1999-01-01

    Full Text Available The effects of chronic mild prenatal stress on leukocyte infiltration into the airways was investigated in rat offspring. The chronic prenatal stress consisted of transitory and variable changes in the rat's living conditions. Offspring at adult age were actively sensitized (day 0 and intratracheally challenged (day 14 with ovalbumin. Bronchoalveolar lavage was performed in the offspring at 48 h after intratracheal challenge with ovalbumin. A significant increase in total leukocyte infiltration was observed in the nonstressed offspring group and this was associated with a marked recruitment of eosinophils without a significant effect on the influx of neutrophils and mononuclear cells. In the prenatal stressed offspring, the counts of both total leukocyte and eosinophils, as well as mononuclear cells, was increased by 50% compared to the non-stressed offspring. We provide here the first experimental evidence that chronic mild unpredictable prenatal stress produces a marked increase in the allergen-induced airway inflammation in the rat offspring.

  19. Dispositional resilience as a moderator of the relationship between chronic stress and irregular menstrual cycle.

    Science.gov (United States)

    Palm-Fischbacher, Simona; Ehlert, Ulrike

    2014-06-01

    Menstrual-cycle irregularity may have an important influence on the subsequent development of chronic diseases. Several risk factors for irregular menstrual cycles have been detected, including stress. Our aim was to extend research on the link between chronic stress and menstrual-cycle irregularity and to assess potential protective factors, such as dispositional resilience, which we hypothesize to be associated with the maintenance or promotion of a healthy menstrual cycle. For this cross-sectional study, data on 696 healthy women aged 20-40 years were obtained. The women completed measures of chronic stress, dispositional resilience and menstrual-cycle irregularity. Furthermore, potential confounds were assessed. Of the participants, 383 (55%) reported no current use of hormonal contraceptives; 313 (45%) reported current use hormonal contraception and were included as a control group. The results suggest that in women not using hormonal contraception, chronic stress (OR = 1.05, 95%CI = 1.02-1.08, p = 0.001) and dispositional resilience (OR = 0.43, 95%CI = 0.31-0.59, p menstrual cycle regularity. In addition, women with greater dispositional resilience have reduced risk for irregular menstrual cycles in the face of low to moderate chronic stress; however, this association is changed at the highest level of chronic stress. These findings suggest that dispositional resilience may be a protective psychological trait that modulates reproductive functioning.

  20. Neurological and cellular regulation of visceral hypersensitivity induced by chronic stress and colonic inflammation in rats

    Science.gov (United States)

    Chen, Jinghong; Winston, John H.; Sarna, Sushil K.

    2013-01-01

    The role of inflammation in inducing visceral hypersensitivity (VHS) in ulcerative colitis patients remains unknown. We tested the hypothesis that acute ulcerative colitis-like inflammation does not induce VHS. However, it sets up molecular conditions such that chronic stress following inflammation exaggerates single unit afferent discharges to colorectal distension. We used dextran sodium sulfate (DSS) to induce ulcerative colitis-like inflammation and a 9-day heterotypic chronic stress protocol in rats. DSS upregulated Nav1.8 mRNA in colon-responsive DRG neurons, TRPV1 in colonic muscularis externae (ME) and BDNF in spinal cord without affecting the spike frequency in spinal afferents or VMR to CRD. By contrast, chronic stress did not induce inflammation but it downregulated Kv1.1 and Kv1.4 mRNA in DRG neurons, and upregulated TRPA1 and NGF in ME, which mediated the increase of spike frequency and VMR to CRD. Chronic stress following inflammation exacerbated spike frequency in spinal afferent neurons. TRPA1 antagonist suppressed the sensitization of afferent neurons. DSS-inflammation did not affect the composition or excitation thresholds of low-threshold and high-threshold fibers. Chronic stress following inflammation increased the percent composition of high-threshold fibers and lowered the excitation threshold of both types of fibers. We conclude that not all types of inflammation induce VHS, whereas chronic stress induces VHS in the absence of inflammation. PMID:23806714

  1. Preliminary behavioral assessment of cagemates living with conspecifics submitted to chronic restraint stress in mice.

    Science.gov (United States)

    Carneiro de Oliveira, P E; Zaniboni, Caroline R; Carmona, Isabela M; Fonseca, Aura R; Canto-de-Souza, Azair

    2017-09-14

    The capacity of rodents to recognize and respond to emotional signs from a conspecific is a valuable adaptive behavior, which provides essential skills for species survival. However, repeated exposure to aversive situations may elicit maladaptive behavioral responses in subjects that experience noxious episodes and their colony members. Previous findings by our group demonstrated that living with a subject in neuropathic pain induces anxiogenic-like behaviors and hypernociception in mice. Whereas chronic pain may be considered a stressful stimulus, we extended our findings on stress-induced emotional transfer. For this purpose, we investigated whether cohabitation with a partner subjected to chronic restraint stress was able to promote alterations in anxiety-like behaviors, pain sensibility and defensive responses. Male Swiss mice were housed in pairs for 14days and then separated into control, stress, and cagemate groups. The stress group was subjected to 14days of restraint stress (1h/day) in the presence of the cagemates, while the pair-housed control group was left undisturbed. A day after last stress session control, stress, and cagemate groups were evaluated using elevated plus maze test, writhing test, and rat exposure test. Results demonstrated that chronic stress attenuated weight gain in the stress group. Moreover, cohabitation with mice subjected to chronic restraint stress induced anxiogenic-like behaviors, pain hypernociception, and alterations in defensive responses in both cagemate and stress groups. These preliminary findings suggest that chronic exposure to aversive stimulus may induce behavioral alterations even in observers. Copyright © 2017. Published by Elsevier B.V.

  2. Moderators and Mediators of the Relationship Between Stress and Insomnia: Stressor Chronicity, Cognitive Intrusion, and Coping

    Science.gov (United States)

    Pillai, Vivek; Roth, Thomas; Mullins, Heather M.; Drake, Christopher L.

    2014-01-01

    Study Objectives: To assess moderators, such as stressor chronicity, and mediators, including stress response in the form of cognitive intrusion and coping behavior, of the prospective association between naturalistic stress and incident insomnia. Design: Longitudinal. Setting: Epidemiological. Participants: A community-based sample of good sleepers (n = 2,892) with no lifetime history of insomnia. Interventions: None. Measurements and Results: Participants reported the number of stressful events they had encountered at baseline, as well as the perceived severity and chronicity of each event. Similarly, volitional stress responses such as coping, as well as more involuntary responses such as cognitive intrusion were assayed for each stressor. Follow-up assessment 1 y hence revealed an insomnia incidence rate of 9.1%. Stress exposure was a significant predictor of insomnia onset, such that the odds of developing insomnia increased by 19% for every additional stressor. Chronicity significantly moderated this relationship, such that the likelihood of developing insomnia as a result of stress exposure increased as a function of chronicity. Cognitive intrusion significantly mediated the association between stress exposure and insomnia. Finally, three specific coping behaviors also acted as mediators: behavioral disengagement, distraction, and substance use. Conclusions: Most studies characterize the relationship between stress exposure and insomnia as a simple dose-response phenomenon. However, our data suggest that certain stressor characteristics significantly moderate this association. Stress response in the form of cognitive intrusion and specific maladaptive coping behaviors mediate the effects of stress exposure. These findings highlight the need for a multidimensional approach to stress assessment in future research and clinical practice. Citation: Pillai V, Roth T, Mullins HM, Drake CL. Moderators and mediators of the relationship between stress and insomnia

  3. Chronic Stress is Prospectively Associated with Sleep in Midlife Women: The SWAN Sleep Study.

    Science.gov (United States)

    Hall, Martica H; Casement, Melynda D; Troxel, Wendy M; Matthews, Karen A; Bromberger, Joyce T; Kravitz, Howard M; Krafty, Robert T; Buysse, Daniel J

    2015-10-01

    Evaluate whether levels of upsetting life events measured over a 9-y period prospectively predict subjective and objective sleep outcomes in midlife women. Prospective cohort study. Four sites across the United States. 330 women (46-57 y of age) enrolled in the Study of Women's Health Across the Nation (SWAN) Sleep Study. N/A. Upsetting life events were assessed annually for up to 9 y. Trajectory analysis applied to life events data quantitatively identified three distinct chronic stress groups: low stress, moderate stress, and high stress. Sleep was assessed by self-report and in-home polysomnography (PSG) during the ninth year of the study. Multivariate analyses tested the prospective association between chronic stress group and sleep, adjusting for race, baseline sleep complaints, marital status, body mass index, symptoms of depression, and acute life events at the time of the Sleep Study. Women characterized by high chronic stress had lower subjective sleep quality, were more likely to report insomnia, and exhibited increased PSG-assessed wake after sleep onset (WASO) relative to women with low to moderate chronic stress profiles. The effect of chronic stress group on WASO persisted in the subsample of participants without baseline sleep complaints. Chronic stress is prospectively associated with sleep disturbance in midlife women, even after adjusting for acute stressors at the time of the sleep study and other factors known to disrupt sleep. These results are consistent with current models of stress that emphasize the cumulative effect of stressors on health over time. © 2015 Associated Professional Sleep Societies, LLC.

  4. Treadmill exercise does not change gene expression of adrenal catecholamine biosynthetic enzymes in chronically stressed rats

    Directory of Open Access Journals (Sweden)

    LJUBICA GAVRILOVIC

    2013-09-01

    Full Text Available ABSTRACT Chronic isolation of adult animals represents a form of psychological stress that produces sympatho-adrenomedullar activation. Exercise training acts as an important modulator of sympatho-adrenomedullary system. This study aimed to investigate physical exercise-related changes in gene expression of catecholamine biosynthetic enzymes (tyrosine hydroxylase, dopamine-ß-hydroxylase and phenylethanolamine N-methyltransferase and cyclic adenosine monophosphate response element-binding (CREB in the adrenal medulla, concentrations of catecholamines and corticosterone (CORT in the plasma and the weight of adrenal glands of chronically psychosocially stressed adult rats exposed daily to 20 min treadmill running for 12 weeks. Also, we examined how additional acute immobilization stress changes the mentioned parameters. Treadmill running did not result in modulation of gene expression of catecholamine synthesizing enzymes and it decreased the level of CREB mRNA in the adrenal medulla of chronically psychosocially stressed adult rats. The potentially negative physiological adaptations after treadmill running were recorded as increased concentrations of catecholamines and decreased morning CORT concentration in the plasma, as well as the adrenal gland hypertrophy of chronically psychosocially stressed rats. The additional acute immobilization stress increases gene expression of catecholamine biosynthetic enzymes in the adrenal medulla, as well as catecholamines and CORT levels in the plasma. Treadmill exercise does not change the activity of sympatho-adrenomedullary system of chronically psychosocially stressed rats.

  5. Effect of chronic restraint stress on immune status of male Sprague Dawley rats.

    Science.gov (United States)

    Moazzam, Sadia; Hussain, M Mazhar; Ahmad, Tahir Aziz

    2013-07-01

    To determine the effect of chronic restraint stress on immune status of Sprague Dawley rats by comparing total leukocyte count (TLC), total lymphocyte count and levels of serum immunoglobulins A, E, G and M of the rats exposed to chronic restraint stress with that of healthy control rats. Quasi-experimental study. Centre of Research in Experimental and Applied Medicine (CREAM), Army Medical College, Rawalpindi, in collaboration of National Institute of Health (NIH), Islamabad, from June 2008 to June 2009. Sixty healthy male Sprague Dawley rats were obtained from NIH. Rats were divided into two groups, each having 30 rats. The rats of group-I were not exposed to chronic restraint stress, while rats of group-II were exposed to chronic restraint stress in meshwire restrainer for 6 hours daily for 15 days. Estimation of total lymphocyte count and serum immunoglobulins (IgG, IgA, IgM and IgE) was carried out and compared between the groups. TLC, lymphocyte count and serum IgA, IgE, IgG and IgM levels were found significantly lower in rats exposed to chronic restraint stress as compared to the rats which were not exposed to stress (p stress compromises immune status of rats by decreasing the levels of immunoglobulins and lymphocyte count.

  6. Chronic obstructive lung disease and posttraumatic stress disorder: current perspectives.

    Science.gov (United States)

    Abrams, Thad E; Blevins, Amy; Weg, Mark W Vander

    2015-01-01

    Several studies have reported on the co-occurrence of chronic obstructive pulmonary disease (COPD) and psychiatric conditions, with the most robust evidence base demonstrating an impact of comorbid anxiety and depression on COPD-related outcomes. In recent years, research has sought to determine if there is a co-occurrence between COPD and posttraumatic stress disorder (PTSD) as well as for associations between PTSD and COPD-related outcomes. To date, there have been no published reviews summarizing this emerging literature. The primary objective of this review was to determine if there is adequate evidence to support a co-occurrence between PTSD and COPD. Secondary objectives were to: 1) determine if there are important clinical considerations regarding the impact of PTSD on COPD management, and 2) identify targeted areas for further research. A structured review was performed using a systematic search strategy limited to studies in English, addressing adults, and to articles that examined: 1) the co-occurrence of COPD and PTSD and 2) the impact of PTSD on COPD-related outcomes. To be included, articles must have addressed some type of nonreversible obstructive lung pathology. A total of 598 articles were identified for initial review. Upon applying the inclusion and exclusion criteria, n=19 articles or abstracts addressed our stated objectives. Overall, there is inconclusive evidence to support the co-occurrence between PTSD and COPD. Studies finding a significant co-occurrence generally had inferior methods of identifying COPD; in contrast, studies that utilized more robust COPD measures (such as a physician exam) generally failed to find a relationship. Among studies that examined the impact of PTSD on COPD-related outcomes, there was more consistent evidence that PTSD affects the perception of respiratory symptom burden and management. In addition, methods for measuring an important confounder (smoking) were generally lacking. There is inconclusive evidence to

  7. Chronic caffeine treatment enhances the resilience to social defeat stress in mice.

    Science.gov (United States)

    Yin, Yong-Qin; Zhang, Chun; Wang, Jian-Xin; Hou, Jia; Yang, Xu; Qin, Jing

    2015-02-01

    Strong evidence has shown that caffeine exerts antidepressant-like effects in chronic stress situations by increasing dopamine levels. However, whether caffeine mediates the dopaminergic system and interferes with the resilience to social defeat stress in mice is unknown. The aim of this study is to investigate the role of caffeine in the behavioral responses to social defeat stress and the possible regulatory role of the dopaminergic system. Mice experienced chronic social defeat stress for 10 days. Caffeine was administered intraperitoneally before, during and after social defeat stress. The time spent in interaction zone, social interaction ratio and sucrose preference test was used to measure the social avoidance and anhedonia in mice. The results showed that chronic pretreatment with caffeine for 14 days and for 10 days during stress reversed the avoidance of social behavior and anhedonia induced by social defeat stress in mice, suggesting the enhancement of the resilience to social defeat stress induced by caffeine. However, neither the treatment with caffeine only during the social defeat stress for 10 days nor the treatment with acute caffeine after defeat stress altered the resilience to stress. Furthermore, chronic caffeine treatment did not affect the normal locomotor activity and the desperate behavior in naïve mice. Moreover, the antagonism of dopamine D1 receptor and not D2 receptor reversed the effect of caffeine on the social avoidance and depressive-like behavior. Finally, pretreatment with higher doses of caffeine did not affect the behavioral response to social defeat stress. Taken together, our findings provide new insight into the effects of caffeine on social avoidance and anhedonia in mice. In addition, our results illustrated the value of measuring changes in depressive-like behavior before and after social defeat stress to determine the potential treatment of caffeine on depression through the regulation of dopaminergic system.

  8. Anxiolytic effects of standardized extract of Centella asiatica (ECa 233) after chronic immobilization stress in mice.

    Science.gov (United States)

    Wanasuntronwong, Aree; Tantisira, Mayuree H; Tantisira, Boonyong; Watanabe, Hiroshi

    2012-09-28

    Centella asiatica has long been used for various neurological disturbances in Southeast Asian countries. The present study aims to demonstrate the anxiolytic effect of ECa 233, a standardized extract of C. asiatica containing triterpenoids not less than 80%, in comparison to diazepam. The test compound was given orally to non-stressed mice and mice subjected to chronic immobilization stress. Anxiolytic effect was assessed by an elevated plus maze (EPM), a dark-light box and an open-field tests. Anxiolytic effect of ECa 233 was clearly demonstrated in non-stressed mice subjected to acute stress in all behavioral tests employed. In the EPM test, chronically stressed mice showed significant decrease in the number of open arm entries, shortening the time spent in open arms and an increase of the latency to leave the central area, suggesting their release from the stress. In addition, ameliorating effect of ECa 233 was observed on the body weight and serum corticosterone which were adversely affected by immobilization stress. Madecassoside and asiaticoside, equal to their respective contents of the effective doses of ECa 233, exclusively presented anxiolytic effects in EPM, while no distinct effect was observed on the body weight and serum corticosterone. The present study demonstrated anxiolytic effect of ECa 233 in both acutely and chronically stressed animals. These effects could be mainly accounted by madecassoside and asiaticoside, suggesting a possible use of ECa 233 for the treatment of both acute and chronic anxiety in the pathological state. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  9. Brief treatment with the glucocorticoid receptor antagonist mifepristone normalizes the reduction in neurogenesis after chronic stress.

    NARCIS (Netherlands)

    Oomen, C.A.; Mayer, J.L.; de Kloet, E.R.; Joëls, M.; Lucassen, P.J.

    2007-01-01

    In rodents, stress suppresses adult neurogenesis. This is thought to involve activation of glucocorticoid receptors in the brain. In the present study, we therefore questioned whether glucocorticoid receptor blockade by mifepristone can normalize the effects of chronic stress on adult neurogenesis.

  10. Protective Effect of Self-Compassion to Emotional Response among Students with Chronic Academic Stress.

    Science.gov (United States)

    Zhang, Yonghong; Luo, Xi; Che, Xianwei; Duan, Wenjie

    2016-01-01

    The literature has shown that self-compassion is a protective factor of an individual's emotional response to chronic stress. However, this stress-buffering effect has not been completely analyzed in individuals who report significantly high academic stress. The present study explored the role of self-compassion in a group of undergraduate students who experience chronic academic stress. A total of 208 undergraduate students who were preparing for the Postgraduate Entrance Examination (PEE) were recruited and completed the Self-Compassion Scale, Adolescent Self-Rating Life Event Check List, and Positive and Negative Affect Schedule. Differences analysis confirmed that the participants reported significantly higher academic stress than their peers who were not preparing for PEE. Self-compassion positively related to positive affect but negatively related to negative affect and learning stress. Further analysis showed that self-compassion negatively mediated the relationship between chronic academic stress and negative affect. Findings imply that self-compassion-centered interventions can be developed in the educational context to assist students cope with chronic academic stress.

  11. Chronic Stress Improves NO- and Ca2+ Flux-Dependent Vascular Function: A Pharmacological Study

    Energy Technology Data Exchange (ETDEWEB)

    Bruder-Nascimento, Thiago, E-mail: bruderthiago@usp.br [Departamento de Farmacologia - Instituto de Biociências de Botucatu - Universidade do Estado de São Paulo (UNESP), Botucatu, São Paulo (Brazil); Departamento de Clínica Médica - Faculdade de Medicina de Botucatu - Universidade do Estado de São Paulo (UNESP), Botucatu, São Paulo (Brazil); Campos, Dijon Henrique Salome [Departamento de Clínica Médica - Faculdade de Medicina de Botucatu - Universidade do Estado de São Paulo (UNESP), Botucatu, São Paulo (Brazil)

    2015-03-15

    Stress is associated with cardiovascular diseases. This study aimed at assessing whether chronic stress induces vascular alterations, and whether these modulations are nitric oxide (NO) and Ca2+ dependent. Wistar rats, 30 days of age, were separated into 2 groups: control (C) and Stress (St). Chronic stress consisted of immobilization for 1 hour/day, 5 days/week, 15 weeks. Systolic blood pressure was assessed. Vascular studies on aortic rings were performed. Concentration-effect curves were built for noradrenaline, in the presence of L-NAME or prazosin, acetylcholine, sodium nitroprusside and KCl. In addition, Ca{sup 2+} flux was also evaluated. Chronic stress induced hypertension, decreased the vascular response to KCl and to noradrenaline, and increased the vascular response to acetylcholine. L-NAME blunted the difference observed in noradrenaline curves. Furthermore, contractile response to Ca{sup 2+} was decreased in the aorta of stressed rats. Our data suggest that the vascular response to chronic stress is an adaptation to its deleterious effects, such as hypertension. In addition, this adaptation is NO- and Ca{sup 2+}-dependent. These data help to clarify the contribution of stress to cardiovascular abnormalities. However, further studies are necessary to better elucidate the mechanisms involved in the cardiovascular dysfunction associated with stressors. (Arq Bras Cardiol. 2014; [online].ahead print, PP.0-0)

  12. Protective Effect of Self-compassion to Emotional Response among Students with Chronic Academic Stress

    Directory of Open Access Journals (Sweden)

    Yonghong Zhang

    2016-11-01

    Full Text Available The literature has shown that self-compassion is a protective factor of an individual’s emo-tional response to chronic stress. However, this stress-buffering effect has not been complete-ly analyzed in individuals who report significantly high academic stress. The present study explored the role of self-compassion in a group of undergraduate students who experience chronic academic stress. A total of 208 undergraduate students who were preparing for the Postgraduate Entrance Examination (PEE were recruited and completed the Self-Compassion Scale, Adolescent Self-Rating Life Event Check List, and Positive and Negative Affect Schedule. Differences analysis confirmed that the participants reported significantly higher academic stress than their peers who were not preparing for PEE. Self-compassion positively related to positive affect but negatively related to negative affect and learning stress. Further analysis showed that self-compassion negatively mediated the relationship be-tween chronic academic stress and negative affect. Findings imply that self-compassion-centered interventions can be developed in the educational context to assist students cope with chronic academic stress.

  13. Chronic Stress Improves NO- and Ca2+ Flux-Dependent Vascular Function: A Pharmacological Study

    Directory of Open Access Journals (Sweden)

    Thiago Bruder-Nascimento

    2015-03-01

    Full Text Available Background: Stress is associated with cardiovascular diseases. Objective: This study aimed at assessing whether chronic stress induces vascular alterations, and whether these modulations are nitric oxide (NO and Ca2+ dependent. Methods: Wistar rats, 30 days of age, were separated into 2 groups: control (C and Stress (St. Chronic stress consisted of immobilization for 1 hour/day, 5 days/week, 15 weeks. Systolic blood pressure was assessed. Vascular studies on aortic rings were performed. Concentration-effect curves were built for noradrenaline, in the presence of L-NAME or prazosin, acetylcholine, sodium nitroprusside and KCl. In addition, Ca2+ flux was also evaluated. Results: Chronic stress induced hypertension, decreased the vascular response to KCl and to noradrenaline, and increased the vascular response to acetylcholine. L-NAME blunted the difference observed in noradrenaline curves. Furthermore, contractile response to Ca2+ was decreased in the aorta of stressed rats. Conclusion: Our data suggest that the vascular response to chronic stress is an adaptation to its deleterious effects, such as hypertension. In addition, this adaptation is NO- and Ca2+-dependent. These data help to clarify the contribution of stress to cardiovascular abnormalities. However, further studies are necessary to better elucidate the mechanisms involved in the cardiovascular dysfunction associated with stressors. (Arq Bras Cardiol. 2014; [online].ahead print, PP.0-0

  14. Chronic stress and social housing differentially affect neurogenesis in male and female rats

    NARCIS (Netherlands)

    Westenbroek, Christel; Boer, Johan A. den; Veenhuis, Maarten; Horst, Gert J. ter

    2004-01-01

    Stress plays an important role in the development of affective disorders. Women show a higher prevalence for these disorders than men. The course of a depression is thought to be positively influenced by social support. We have used a chronic stress model in which rats received foot-shocks daily for

  15. Stress effects on rats chronically receiving a highly palatable diet are sex-specific.

    Science.gov (United States)

    Fachin, Andrelisa; Silva, Rachel Krolow S; Noschang, Cristie G; Pettenuzzo, Leticia; Bertinetti, Liane; Billodre, Mauro Nör; Peres, William; Busnello, Fernanda; Dalmaz, Carla

    2008-11-01

    The stress response is known to lead to behavioral and metabolic changes. Exposure to chronic stress can promote the development of physiological and behavioral dysfunctions, including alterations in feeding behavior. The aim of this study was to verify whether chronic restraint stress alters the consumption of a highly palatable, highly caloric diet (chocolate), chronically offered to the animals. Male rats ate more chocolate than females, and they also exhibited a higher weight gain, abdominal fat deposition, and higher plasma levels of total cholesterol, LDL-cholesterol and glucose. The stress exposure decreased body weight, increased adrenal weight and decreased plasma insulin levels. Overall, female rats had lower plasma insulin levels and chocolate consumption prevented the increased adrenal gland weight after exposure to chronic stress, suggesting a reduction of stress effects induced by palatable food consumption. Taken together, these results suggest a peculiar metabolic pattern, related to energy store and expenditure, in stressed animals receiving a palatable diet. Since these effects were sex-specific, we may also propose that females and males subjected to restraint stress and chocolate consumption are differentially affected.

  16. Stress activates pronociceptive endogenous opioid signalling in DRG neurons during chronic colitis.

    Science.gov (United States)

    Guerrero-Alba, Raquel; Valdez-Morales, Eduardo E; Jimenez-Vargas, Nestor N; Lopez-Lopez, Cintya; Jaramillo-Polanco, Josue; Okamoto, Takanobu; Nasser, Yasmin; Bunnett, Nigel W; Lomax, Alan E; Vanner, Stephen J

    2017-12-01

    Psychological stress accompanies chronic inflammatory diseases such as IBD, and stress hormones can exacerbate pain signalling. In contrast, the endogenous opioid system has an important analgesic action during chronic inflammation. This study examined the interaction of these pathways. Mouse nociceptive dorsal root ganglia (DRG) neurons were incubated with supernatants from segments of inflamed colon collected from patients with chronic UC and mice with dextran sodium sulfate (cDSS)-induced chronic colitis. Stress effects were studied by adding stress hormones (epinephrine and corticosterone) to dissociated neurons or by exposing cDSS mice to water avoidance stress. Changes in excitability of colonic DRG nociceptors were measured using patch clamp and Ca 2+ imaging techniques. Supernatants from patients with chronic UC and from colons of mice with chronic colitis caused a naloxone-sensitive inhibition of neuronal excitability and capsaicin-evoked Ca 2+ responses. Stress hormones decreased signalling induced by human and mouse supernatants. This effect resulted from stress hormones signalling directly to DRG neurons and indirectly through signalling to the immune system, leading to decreased opioid levels and increased acute inflammation. The net effect of stress was a change endogenous opioid signalling in DRG neurons from an inhibitory to an excitatory effect. This switch was associated with a change in G protein-coupled receptor excitatory signalling to a pathway sensitive to inhibitors of protein kinase A-protein, phospholipase C-protein and G protein βϒ subunits. Stress hormones block the inhibitory actions of endogenous opioids and can change the effect of opioid signalling in DRG neurons to excitation. Targeting these pathways may prevent heavy opioid use in IBD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  17. Acute and Chronic Posttraumatic Stress Symptoms in the Emergence of Posttraumatic Stress Disorder: A Network Analysis.

    Science.gov (United States)

    Bryant, Richard A; Creamer, Mark; O'Donnell, Meaghan; Forbes, David; McFarlane, Alexander C; Silove, Derrick; Hadzi-Pavlovic, Dusan

    2017-02-01

    Little is understood about how the symptoms of posttraumatic stress develop over time into the syndrome of posttraumatic stress disorder (PTSD). To use a network analysis approach to identify the nature of the association between PTSD symptoms in the acute phase after trauma and the chronic phase. A prospective cohort study enrolled 1138 patients recently admitted with traumatic injury to 1 of 4 major trauma hospitals across Australia from March 13, 2004, to February 26, 2006. Participants underwent assessment during hospital admission (n = 1388) and at 12 months after injury (n = 852). Networks of symptom associations were analyzed in the acute and chronic phases using partial correlations, relative importance estimates, and centrality measures of each symptom in terms of its association strengths, closeness to other symptoms, and importance in connecting other symptoms to each other. Data were analyzed from March 3 to September 5, 2016. Severity of PTSD was assessed at each assessment with the Clinician-Administered PTSD Scale. Of the 1138 patients undergoing assessment at admission (837 men [73.6%] and 301 women [26.4%]; mean [SD] age, 37.90 [13.62] years), strong connections were found in the acute phase. Reexperiencing symptoms were central to other symptoms in the acute phase, with intrusions and physiological reactivity among the most central symptoms in the networks in terms of the extent to which they occur between other symptoms (mean [SD], 1.2 [0.7] and 1.0 [0.9], respectively), closeness to other symptoms (mean [SD], 0.9 [0.3] and 1.1 [0.9], respectively), and strength of the associations (mean [SD], 1.6 [0.3] and 1.5 [0.3] respectively) among flashbacks, intrusions, and avoidance of thoughts, with moderately strong connections between intrusions and nightmares, being upset by reminders, and physiological reactivity. Intrusions and physiological reactivity were central in the acute phase. Among the 852 patients (73.6%) who completed the 12-month

  18. Identification of Risk Factors for Chronic Posttraumatic Stress Disorder (PTSD)

    National Research Council Canada - National Science Library

    Shea, M. T; Hebert, Norman J

    2007-01-01

    The primary research aims are to examine the early longitudinal course of PTSD symptoms and test hypotheses regarding risk factors for chronic PTSD in military personnel returning from Iraq or Afghanistan...

  19. Chronic stress and obesity: a new view of "comfort food"

    NARCIS (Netherlands)

    Dallman, Mary F.; Pecoraro, Norman; Akana, Susan F.; la Fleur, Susanne E.; Gomez, Francisca; Houshyar, Hani; Bell, M. E.; Bhatnagar, Seema; Laugero, Kevin D.; Manalo, Sotara

    2003-01-01

    The effects of adrenal corticosteroids on subsequent adrenocorticotropin secretion are complex. Acutely (within hours), glucocorticoids (GCs) directly inhibit further activity in the hypothalamo-pituitary-adrenal axis, but the chronic actions (across days) of these steroids on brain are directly

  20. Polymers as advanced materials for desiccant applications

    Energy Technology Data Exchange (ETDEWEB)

    Czanderna, A.W.

    1990-12-01

    This research is concerned with solid materials used as desiccants for desiccant cooling systems (DCSs) that process water vapor in an atmosphere to produce cooling. Background information includes an introduction to DCSs and the role of the desiccant as a system component. The water vapor sorption performance criteria used for screening the modified polymers prepared include the water sorption capacity from 5% to 80% relative humidity (R.H.), isotherm shape, and rate of adsorption and desorption. Measurements are presented for the sorption performance of modified polymeric advanced desiccant materials with the quartz crystal microbalance. Isotherms of polystyrene sulfonic acid (PSSA) taken over a 5-month period show that the material has a dramatic loss in capacity and that the isotherm shape is time dependent. The adsorption and desorption kinetics for PSSA and all the ionic salts of it studied are easily fast enough for commercial DCS applications with a wheel rotation speed of 6 min per revolution. Future activities for the project are addressed, and a 5-year summary of the project is included as Appendix A. 34 refs., 20 figs., 3 tabs.

  1. Soil nitrogen dynamics after Brachiaria desiccation

    Directory of Open Access Journals (Sweden)

    Gustavo Castoldi

    2013-12-01

    Full Text Available Brachiaria species, particularly B. humidicola, can synthesize and release compounds from their roots that inhibit nitrification, which can lead to changes in soil nitrogen (N dynamics, mainly in N-poor soils. This may be important in crop-livestock integration systems, where brachiarias are grown together with or in rotation with grain crops. The objective of the present study was to determine whether this holds true in N-rich environments and if other Brachiaria species have the same effect. The soil N dynamics were evaluated after the desiccation of the species B. brizantha, B. decumbens, B. humidicola, and B. ruziziensis, which are widely cultivated in Brazil. The plants were grown in pots with a dystroferric Red Latosol in a greenhouse. Sixty days after sowing, the plants were desiccated using glyphosate herbicide. The plants and soil were analyzed on the day of desiccation and 7, 14, 21 and 28 days after desiccation. The rhizosphere soil of the grasses contained higher levels of organic matter, total N and ammonium than the non-rhizosphere soil. The pH was lowest in the rhizosphere of B. humidicola, which may indicate that this species inhibits the nitrification process. However, variations in the soil ammonium and nitrate levels were not sufficient to confirm the suppressive effect of B. humidicola. The same was observed for B. brizantha, B. decumbens and B. ruziziensis, thereby demonstrating that, where N is abundant, none of the brachiarias studied has a significant effect on the nitrification process in soil.

  2. Desiccation tolerance in seeds and plants

    NARCIS (Netherlands)

    Dias Costa, M.C.

    2016-01-01

    The interest of research groups in desiccation tolerance (DT) has increased substantially over the last decades. The emergence of germinated orthodox seeds and resurrection plants as main research models has pushed the limits of our knowledge beyond boundaries. At the same time, new questions and

  3. Desiccation tolerance in seeds and plants

    NARCIS (Netherlands)

    Dias Costa, M.C.

    2016-01-01

    The interest of research groups in desiccation tolerance (DT) has increased substantially over the last decades. The emergence of germinated orthodox seeds and resurrection plants as main research models has pushed the limits of our knowledge beyond boundaries. At the same time, new questions and

  4. Molecular Signatures of Psychosocial Stress and Cognition Are Modulated by Chronic Lithium Treatment.

    Science.gov (United States)

    Brzózka, Magdalena M; Havemann-Reinecke, Ursula; Wichert, Sven P; Falkai, Peter; Rossner, Moritz J

    2016-07-01

    Chronic psychosocial stress is an important environmental risk factor of psychiatric diseases such as schizophrenia. Social defeat in rodents has been shown to be associated with maladaptive cellular and behavioral consequences including cognitive impairments. Although gene expression changes upon psychosocial stress have been described, a comprehensive transcriptome profiling study at the global level in precisely defined hippocampal subregions which are associated with learning has been lacking. In this study, we exposed adult C57Bl/6N mice for 3 weeks to "resident-intruder" paradigm and combined laser capture microdissection with microarray analyses to identify transcriptomic signatures of chronic psychosocial stress in dentate gyrus and CA3 subregion of the dorsal hippocampus. At the individual transcript level, we detected subregion specific stress responses whereas gene set enrichment analyses (GSEA) identified several common pathways upregulated upon chronic psychosocial stress related to proteasomal function and energy supply. Behavioral profiling revealed stress-associated impairments most prominent in fear memory formation which was prevented by chronic lithium treatment. Thus, we again microdissected the CA3 region and performed global transcriptome analysis to search for molecular signatures altered by lithium treatment in stressed animals. By combining GSEA with unsupervised clustering, we detected pathways that are regulated by stress and lithium in the CA3 region of the hippocampus including proteasomal components, oxidative phosphorylation, and anti-oxidative mechanisms. Our study thus provides insight into hidden molecular phenotypes of chronic psychosocial stress and lithium treatment and proves a beneficial role for lithium treatment as an agent attenuating negative effects of psychosocial stress on cognition. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For

  5. Decreased plasticity of glucoregulatory responses in aged rats: effects of chronic stress.

    Science.gov (United States)

    Odio, M; Brodish, A

    1991-09-01

    These experiments were conducted to determine the effects of age and chronic stress on the ability of rats to attenuate stimulus-induced glucose and insulin responses during repeated exposure to a mild stressor. Young (5-month) and old (21-month) Fischer 344 male rats were either exposed to intermittent sessions of an escapable footshock stress for 3 months, or to no chronic stress. Afterwards, blood samples were obtained from each rat before, during, and after the first and fourth exposure to a novel motion stimulus. Between the first and the fourth exposure to the motion stimulus a pronounced attenuation of glucose and insulin responses was seen in both groups of young rats, and in old chronically stressed rats, but not in old control animals. Thus, it appears that the adverse effects of aging on plasticity of glucoregulatory response processes were significantly diminished by exposure of the animals to periodic challenges from their external environment.

  6. Modified Aloe Polysaccharide Restores Chronic Stress-Induced Immunosuppression in Mice.

    Science.gov (United States)

    Lee, Youngjoo; Im, Sun-A; Kim, Jiyeon; Lee, Sungwon; Kwon, Junghak; Lee, Heetae; Kong, Hyunseok; Song, Youngcheon; Shin, Eunju; Do, Seon-Gil; Lee, Chong-Kil; Kim, Kyungjae

    2016-09-30

    Chronic stress generally experienced in our daily lives; is known to augment disease vulnerability by suppressing the host immune system. In the present study; the effect of modified Aloe polysaccharide (MAP) on chronic stress-induced immunosuppression was studied; this Aloe compound was characterized in our earlier study. Mice were orally administered with MAP for 24 days and exposed to electric foot shock (EFS; duration; 3 min; interval; 10 s; intensity; 2 mA) for 17 days. The stress-related immunosuppression and restorative effect of MAP were then analyzed by measuring various immunological parameters. MAP treatment alleviated lymphoid atrophy and body weight loss. The numbers of lymphocyte subsets were significantly normalized in MAP-treated mice. Oral administration of MAP also restored the proliferative activities of lymphocytes; ovalbumin (OVA)-specific T cell proliferation; antibody production; and the cell killing activity of cytotoxic T lymphocytes. In summary; oral administration of MAP ameliorated chronic EFS stress-induced immunosuppression.

  7. Overgeneral autobiographical memory and chronic interpersonal stress as predictors of the course of depression in adolescents.

    Science.gov (United States)

    Sumner, Jennifer A; Griffith, James W; Mineka, Susan; Rekart, Kathleen Newcomb; Zinbarg, Richard E; Craske, Michelle G

    2011-01-01

    This study investigated whether overgeneral autobiographical memory (OGM) predicts the course of depression in adolescents. As part of a larger longitudinal study of risk for emotional disorders, 55 adolescents with a past history of major depressive disorder or minor depressive disorder completed the Autobiographical Memory Test. Fewer specific memories predicted the subsequent onset of a major depressive episode (MDE) over a 16-month follow-up period, even when covarying baseline depressive symptoms. This main effect was qualified by an interaction between specific memories and chronic interpersonal stress: Fewer specific memories predicted greater risk of MDE onset over follow-up at high (but not low) levels of chronic interpersonal stress. Thus, our findings suggest that OGM, in interaction with chronic interpersonal stress, predicts the course of depression among adolescents, and highlight the importance of measuring interpersonal stress in OGM research. © 2010 Psychology Press, an imprint of the Taylor & Francis Group, an Informa business

  8. Some physiological and biochemical methods for acute and chronic stress evaluation in dairy cows

    Directory of Open Access Journals (Sweden)

    Giuseppe Bertoni

    2010-01-01

    Full Text Available Stress factors are so numerous and so diverse in their strength and duration that the consequences on animal welfare can be quite varied. The first important distinction concerns the characterization of acute and chronic stress conditions. Acute stress is a short-lived negative situation that allows a quick and quite complete recovery of the physiological balance (adaptation, while chronic stress is a long lasting condition from which the subject cannot fully recover (maladaptation. In the latter case, the direct effects of the stress factors (heat, low energy, anxiety, suffering etc., as well as the indirect ones (changes occurring at endocrinological, immune system or function level can be responsible for pre-pathological or pathological consequences which reduce animal welfare. To evaluate the possible chronic stress conditions in single animals or on a farm (in particular a farm of dairy cows, some parameters of the direct or indirect effects can be utilised. They are physiological (mainly hormone changes: cortisol, β-endorphin, behavioural (depression, biochemical (metabolites, acute phase proteins, glycated proteins etc., as well as performance parameters (growing rate, milk yield, fertility, etc.. Special attention has been paid to the interpretation of cortisol levels and to its changes after an ACTH challenge. Despite fervent efforts, well established and accepted indices of chronic stress (distress are currently lacking; but without this objective evaluation, the assessment of animal welfare and, therefore, the optimization of the livestock production, could prove more difficult.

  9. Chronic stress and decreased physical exercise: impact on weight for African American women.

    Science.gov (United States)

    Moore-Greene, Gracie M; Gross, Susan M; Silver, Kristi D; Perrino, Carrol S

    2012-01-01

    African American women continue to have the highest prevalence of obesity in the United States and in the state of Maryland they are disproportionately affected by overweight and obesity. There are many contributing factors including chronic stress and the use of health behaviors such as physical exercise that play a role in increased weight for African American women. We examined the relationship of stress to weight and the role of physical exercise in African American paraprofessional women. Cross-sectional study African American paraprofessionals were asked about their perspectives regarding association with chronic stress and physical exercise. The three most salient stressors for the women were finances (33%), work (28%) and family/friends (19%). Ninety percent of the women were overweight or obese. Significant predictors of increased BMI were lack of physical exercise (P = .004) and health compared to others (P = .006). Ethnic discrimination was a form of chronic stress (r = .319) but was not correlated with BMI (r = .095). Decreased physical exercise (P = .02) mediated the relationship between chronic stress and BMI. Findings regarding finance and work stress suggest the need for employers to consider the impact of job strain when implementing employee health programs to decrease stress and improve health. A focus on decreased physical exercise, unhealthy eating habits and misperceptions regarding increased risk for obesity related diseases with health status may be helpful to include in intervention strategies to decrease obesity for this population.

  10. High-fat diet effects on metabolic responses to chronic stress.

    Science.gov (United States)

    Nemati, Marzieh; Zardooz, Homeira; Rostamkhani, Fatemeh; Abadi, Alireza; Foroughi, Forough

    2017-07-01

    High-fat diets and chronic stress are prevalent risk factors for various chronic diseases in modern societies. This study investigated the effect of high-fat diet on glucose-related metabolic responses to chronic foot-shock stress. Male rats were divided into high-fat diet (containing 54.21% saturated and 44.89% unsaturated fatty acids) and normal diet groups and then into stress and non-stress subgroups. The diets were applied for 5 weeks, and stress was induced during the last week of the diet course. Plasma levels of metabolic parameters, HOMA-IR index, intra-abdominal fat weight, and islets' insulin secretion were assessed. High-fat diet increased abdominal fat weight and plasma leptin, and insulin levels in response to stress without affecting HOMA-IR index and islets' insulin secretion. High proportion of unsaturated fat may not lead to deleterious metabolic responses; however combined with chronic stress has a synergistic and adverse effect on visceral adiposity and results in elevated plasma leptin.

  11. Ex-vivo diffusion MRI reveals microstructural alterations in stress-sensitive brain regions: A chronic mild stress recovery study

    DEFF Research Database (Denmark)

    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....

  12. Chronic Stress and Three Mile Island: Toxic Exposure and Uncertainty.

    Science.gov (United States)

    Davidson, Laura M.; And Others

    Although many researchers expected the psychological effects of the accident at the Three Mile Island (TMI) nuclear plant to be short-lived, area residents continued to show elevated levels of stress. To examine stress levels of TMI residents 28 months after the accident, 141 subjects were chosen from nearby areas, and from a town 80 miles away.…

  13. Low pressure and desiccation effects on methanogens: Implications for life on Mars

    Science.gov (United States)

    Kral, Timothy A.; Altheide, Travis S.; Lueders, Adrienne E.; Schuerger, Andrew C.

    2011-02-01

    Conditions on the surface of Mars would appear to be too hostile for life as we know it. But the subsurface is another matter. If liquid water is present, even intermittently, life forms present would at least be protected from the lethal radiation bombarding the surface. However, life would have to contend with variations in pressure and possibly extended periods of desiccation. The research reported here involves both active metabolism (methanogenesis) at 400 and 50 mbar of pressure, pressures that would be found in the near subsurface of Mars, and survival following desiccation at both 1 bar (a pressure that would be found in the Martian subsurface) and 6 mbar (the lowest pressure at the surface and very near subsurface). The three methanogens tested for active metabolism, Methanothermobacter wolfeii, Methanosarcina barkeri and Methanobacterium formicicum, all demonstrated methane production at both 400 and 50 mbar on JSC Mars-1, a Mars soil simulant. Methane production at 50 mbar was much reduced compared to that at 400 mbar, most likely due to the greater stress at the lower pressure. In desiccation survival experiments, M. barkeri had survived 330 days of desiccation at 1 bar, while M. wolfeii and M. formicicum survived 180 and 120 days, respectively. Methanococcus maripaludis did not survive desiccation at all at 1 bar. At 6 mbar, M. wolfeii, M. barkeri and M. formicicum survived 120 days of desiccation while M. maripaludis survived 60 days. These results along with results from previous research would seem to indicate that there is no reason that methanogens could not inhabit the subsurface of Mars.

  14. Biosentinel: Improving Desiccation Tolerance of Yeast Biosensors for Deep-Space Missions

    Science.gov (United States)

    Dalal, Sawan; Santa Maria, Sergio R.; Liddell, Lauren; Bhattacharya, Sharmila

    2017-01-01

    BioSentinel is one of 13 secondary payloads to be deployed on Exploration Mission 1 (EM-1) in 2019. We will use the budding yeast Saccharomyces cerevisiae as a biosensor to determine how deep-space radiation affects living organisms and to potentially quantify radiation levels through radiation damage analysis. Radiation can damage DNA through double strand breaks (DSBs), which can normally be repaired by homologous recombination. Two yeast strains will be air-dried and stored in microfluidic cards within the payload: a wild-type control strain and a radiation sensitive rad51 mutant that is deficient in DSB repairs. Throughout the mission, the microfluidic cards will be rehydrated with growth medium and an indicator dye. Growth rates of each strain will be measured through LED detection of the reduction of the indicator dye, which correlates with DNA repair and the amount of radiation damage accumulated. Results from BioSentinel will be compared to analog experiments on the ISS and on Earth. It is well known that desiccation can damage yeast cells and decrease viability over time. We performed a screen for desiccation-tolerant rad51 strains. We selected 20 re-isolates of rad51 and ran a weekly screen for desiccation-tolerant mutants for five weeks. Our data shows that viability decreases over time, confirming previous research findings. Isolates L2, L5 and L14 indicate desiccation tolerance and are candidates for whole-genome sequencing. More time is needed to determine whether a specific strain is truly desiccation tolerant. Furthermore, we conducted an intracellular trehalose assay to test how intracellular trehalose concentrations affect or protect the mutant strains against desiccation stress. S. cerevisiae cell and reagent concentrations from a previously established intracellular trehalose protocol did not yield significant absorbance measurements, so we tested varying cell and reagent concentrations and determined proper concentrations for successful

  15. Plasma omega 3 polyunsaturated fatty acid status and monounsaturated fatty acids are altered by chronic social stress and predict endocrine responses to acute stress in titi monkeys

    Science.gov (United States)

    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 ...

  16. Chronic stress-induced alterations in mouse colonic 5-HT and defecation responses are strain dependent.

    Science.gov (United States)

    Julio-Pieper, Marcela; O'Mahony, Cliona M; Clarke, Gerard; Bravo, Javier A; Dinan, Timothy G; Cryan, John F

    2012-03-01

    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.

  17. Chronic stress exposure decreases the cortisol awakening response in healthy young men.

    Science.gov (United States)

    Duan, Hongxia; Yuan, Yiran; Zhang, Liang; Qin, Shaozheng; Zhang, Kan; Buchanan, Tony W; Wu, Jianhui

    2013-11-01

    Academic examination is a major stressor for students in China. Investigation of stress-sensitive endocrine responses to major examination stress serves as a good model of naturalistic chronic psychological stress in an otherwise healthy population. The cortisol awakening response (CAR) is an endocrine marker of the hypothalamic-pituitary-adrenocortical (HPA) axis in response to stress. However, it remains unknown how chronic examination stress impacts the CAR in a young healthy population To exclude the influence of sex effects on hormone level, the CAR and psychological stress responses were assessed on two consecutive workdays in 42 male participants during their preparations for the Chinese National Postgraduate Entrance Exam (NPEE) and 21 non-exam, age-matched male comparisons. On each day, four saliva samples were collected immediately after awakening, 15 minutes, 30 minutes and 60 minutes after awakening. The waking level (S1), the increase within 30 minutes after awakening (R30), the area under the curve with respect to ground (AUCg), and the area under the curve with respect to increase (AUCi) were used to quantify the CAR. Psychological stress and anxiety were assessed by the Perceived Stress Scale and the Spielberger State-Trait Anxiety Inventory, respectively. Male participants in the exam group had greater perceived stress and anxiety scores relatibe to the non-exam group. Both R30 and AUCi in the exam group were significantly lower than the comparison group and this effect was most pronounced for participants with high levels of perceived stress in the exam group. Perceived stress and anxiety levels were negatively correlated with both R30 and AUCi. Chronic examination stress can lead to the decrease of CAR in healthy young men, possibly due to reduced HPA axis activity under long-term sustained stress.

  18. Perceived Chronic Stress Exposure Modulates Reward-Related Medial Prefrontal Cortex Responses to Acute Stress in Depression

    Science.gov (United States)

    Kumar, Poornima; Slavich, George M.; Berghorst, Lisa H.; Treadway, Michael T.; Brooks, Nancy H.; Dutra, Sunny J.; Greve, Douglas N.; O'Donovan, Aoife; Bleil, Maria E.; Maninger, Nicole; Pizzagalli, Diego A.

    2015-01-01

    Introduction Major depressive disorder (MDD) is often precipitated by life stress and growing evidence suggests that stress-induced alterations in reward processing may contribute to such risk. However, no human imaging studies have examined how recent life stress exposure modulates the neural systems that underlie reward processing in depressed and healthy individuals. Methods In this proof-of-concept study, 12 MDD and 10 psychiatrically healthy individuals were interviewed using the Life Events and Difficulties Schedule (LEDS) to assess their perceived levels of recent acute and chronic life stress exposure. Additionally, each participant performed a monetary incentive delay task under baseline (no-stress) and stress (social-evaluative) conditions during functional MRI. Results Across groups, medial prefrontal cortex (mPFC) activation to reward feedback was greater during acute stress versus no-stress conditions in individuals with greater perceived stressor severity. Under acute stress, depressed individuals showed a positive correlation between perceived stressor severity levels and reward-related mPFC activation (r = 0.79, p = 0.004), whereas no effect was found in healthy controls. Moreover, for depressed (but not healthy) individuals, the correlations between the stress (r = 0.79) and no-stress (r = −0.48) conditions were significantly different. Finally, relative to controls, depressed participants showed significantly reduced mPFC grey matter, but functional findings remained when accounting for structural differences. Limitation Small sample size, which warrants replication. Conclusion Depressed individuals experiencing greater recent life stress recruited the mPFC more under stress when processing rewards. Our results represent an initial step toward elucidating mechanisms underlying stress sensitization and recurrence in depression. PMID:25898329

  19. Survival of Deinococcus geothermalis in Biofilms under Desiccation and Simulated Space and Martian Conditions

    Science.gov (United States)

    Frösler, Jan; Panitz, Corinna; Wingender, Jost; Flemming, Hans-Curt; Rettberg, Petra

    2017-05-01

    Biofilm formation represents a successful survival strategy for bacteria. In biofilms, cells are embedded in a matrix of extracellular polymeric substances (EPS). As they are often more stress-tolerant than single cells, biofilm cells might survive the conditions present in space and on Mars. To investigate this topic, the bacterium Deinococcus geothermalis was chosen as a model organism due to its tolerance toward desiccation and radiation. Biofilms cultivated on membranes and, for comparison, planktonically grown cells deposited on membranes were air-dried and exposed to individual stressors that included prolonged desiccation, extreme temperatures, vacuum, simulated martian atmosphere, and UV irradiation, and they were exposed to combinations of stressors that simulate space (desiccation + vacuum + UV) or martian (desiccation + Mars atmosphere + UV) conditions. The effect of sulfatic Mars regolith simulant on cell viability during stress was investigated separately. The EPS produced by the biofilm cells contained mainly polysaccharides and proteins. To detect viable but nonculturable (VBNC) cells, cultivation-independent viability indicators (membrane integrity, ATP, 16S rRNA) were determined in addition to colony counts. Desiccation for 2 months resulted in a decrease of culturability with minor changes of membrane integrity in biofilm cells and major loss of membrane integrity in planktonic bacteria. Temperatures between -25°C and +60°C, vacuum, and Mars atmosphere affected neither culturability nor membrane integrity in both phenotypes. Monochromatic (254 nm; ≥1 kJ m-2) and polychromatic (200-400 nm; >5.5 MJ m-2 for planktonic cells and >270 MJ m-2 for biofilms) UV irradiation significantly reduced the culturability of D. geothermalis but did not affect cultivation-independent viability markers, indicating the induction of a VBNC state in UV-irradiated cells. In conclusion, a substantial proportion of the D. geothermalis population remained viable under

  20. Stress resilience: a low-anxiety genotype protects male mice from the consequences of chronic psychosocial stress.

    Science.gov (United States)

    Füchsl, Andrea M; Neumann, Inga D; Reber, Stefan O

    2014-01-01

    Chronic psychosocial stress is a risk factor for the development of affective as well as somatic disorders. However, vulnerability to adverse stress effects varies between individuals, with previous negative life events along with genetic predisposition playing a major role. In support, we previously showed that the consequences of chronic psychosocial stress induced by chronic subordinate colony housing (CSC, 19 days) can be amplified by pre-exposing mice to repeated maternal separation during early life. To test the significance of the genetic predisposition on the effects of CSC, mice selectively bred for high (mHAB) and low (mLAB) anxiety-related behavior and nonselected CD1 mice (mNAB) were exposed to CSC in the present study. In confirmation of our previous results, CSC mice of both mHAB and mNAB lines displayed chronic stress-related symptoms including increased adrenal weight, decreased adrenal in vitro ACTH sensitivity, lower plasma corticosterone to ACTH ratio, and increased interferon-γ secretion from isolated mesenteric lymph node cells compared with single-housed controls of the respective line. However, the CSC-induced anxiogenic effect found in mNAB was not confirmed in mHAB mice, possibly due to a ceiling effect in these highly anxious mice. Interestingly, mHAB were not more vulnerable to CSC than mNAB mice, whereas mLAB mice were resilient to CSC as indicated by all of the above mentioned parameters assessed. Taken together, our findings indicate that the genetic predisposition, in this case the innate anxiety of an individual, affects vulnerability to chronic psychosocial stress, with a low-anxiety phenotype mediating resilience to both affective and somatic consequences of CSC.

  1. Chronic stress impacts the cardiovascular system: animal models and clinical outcomes.

    Science.gov (United States)

    Golbidi, Saeid; Frisbee, Jefferson C; Laher, Ismail

    2015-06-15

    Psychological stresses are associated with cardiovascular diseases to the extent that cardiovascular diseases are among the most important group of psychosomatic diseases. The longstanding association between stress and cardiovascular disease exists despite a large ambiguity about the underlying mechanisms. An array of possibilities have been proposed including overactivity of the autonomic nervous system and humoral changes, which then converge on endothelial dysfunction that initiates unwanted cardiovascular consequences. We review some of the features of the two most important stress-activated systems, i.e., the humoral and nervous systems, and focus on alterations in endothelial function that could ensue as a result of these changes. Cardiac and hematologic consequences of stress are also addressed briefly. It is likely that activation of the inflammatory cascade in association with oxidative imbalance represents key pathophysiological components of stress-induced cardiovascular changes. We also review some of the commonly used animal models of stress and discuss the cardiovascular outcomes reported in these models of stress. The unique ability of animals for adaptation under stressful conditions lessens the extrapolation of laboratory findings to conditions of human stress. An animal model of unpredictable chronic stress, which applies various stress modules in a random fashion, might be a useful solution to this predicament. The use of stress markers as indicators of stress intensity is also discussed in various models of animal stress and in clinical studies. Copyright © 2015 the American Physiological Society.

  2. Environmental enrichment reduces behavioural alterations induced by chronic stress in Japanese quail.

    Science.gov (United States)

    Laurence, A; Houdelier, C; Calandreau, L; Arnould, C; Favreau-Peigné, A; Leterrier, C; Boissy, A; Lumineau, S

    2015-02-01

    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.

  3. Mice lacking integrin β3 expression exhibit altered response to chronic stress

    Directory of Open Access Journals (Sweden)

    Seth Varney

    2015-01-01

    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.

  4. Unique genetic loci identified for emotional behavior in control and chronic stress conditions.

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    Kimberly AK Carhuatanta

    2014-10-01

    Full Text Available An individual’s genetic background affects their emotional behavior and response to stress. Although studies have been conducted to identify genetic predictors for emotional behavior or stress response, it remains unknown how prior stress history alters the interaction between an individual’s genome and their emotional behavior. Therefore, the purpose of this study is to identify chromosomal regions that affect emotional behavior and are sensitive to stress exposure. We utilized the BXD behavioral genetics mouse model to identify chromosomal regions that predict fear learning and emotional behavior following exposure to a control or chronic stress environment. 62 BXD recombinant inbred strains and C57BL/6 and DBA/2 parental strains underwent behavioral testing including a classical fear conditioning paradigm and the elevated plus maze. Distinct quantitative trait loci (QTLs were identified for emotional learning, anxiety and locomotion in control and chronic stress populations. Candidate genes, including those with already known functions in learning and stress were found to reside within the identified QTLs. Our data suggest that chronic stress history reveals novel genetic predictors of emotional behavior.

  5. Adolescent vulnerability to cardiovascular consequences of chronic emotional stress: Review and perspectives for future research.

    Science.gov (United States)

    Crestani, Carlos C

    2017-03-01

    Emotional stress has been recognized as a modifiable risk factor for cardiovascular diseases. Adolescence has been proposed as a developmental period of vulnerability to stress. This idea has been mainly supported by experimental research in animals demonstrating a higher impact of chronic emotional stress in adolescents compared with adults. Adolescent vulnerability is also based on evidence that stress during this developmental period affects development, so that enduring changes are found in adult animals that experienced stress during adolescence. The purpose of the present review is to discuss experimental research in rodent models that investigated the impact of long-term exposure to stressful events during adolescence on cardiovascular function. The development of cardiovascular function and autonomic activity in rodents is initially reviewed. Then, a discussion of an adolescent vulnerability to cardiovascular effects of chronic stress is presented. From the reviewed literature, perspective for future research is proposed to better elucidate adolescent vulnerability to cardiovascular complications evoked by chronic emotional stress. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Impaired Latent Inhibition in GDNF-Deficient Mice Exposed to Chronic Stress

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    Mona Buhusi

    2017-10-01

    Full Text Available Increased reactivity to stress is maladaptive and linked to abnormal behaviors and psychopathology. Chronic unpredictable stress (CUS alters catecholaminergic neurotransmission and remodels neuronal circuits involved in learning, attention and decision making. Glial-derived neurotrophic factor (GDNF is essential for the physiology and survival of dopaminergic neurons in substantia nigra and of noradrenergic neurons in the locus coeruleus. Up-regulation of GDNF expression during stress is linked to resilience; on the other hand, the inability to up-regulate GDNF in response to stress, as a result of either genetic or epigenetic modifications, induces behavioral alterations. For example, GDNF-deficient mice exposed to chronic stress exhibit alterations of executive function, such as increased temporal discounting. Here we investigated the effects of CUS on latent inhibition (LI, a measure of selective attention and learning, in GDNF-heterozygous (HET mice and their wild-type (WT littermate controls. No differences in LI were found between GDNF HET and WT mice under baseline experimental conditions. However, following CUS, GDNF-deficient mice failed to express LI. Moreover, stressed GDNF-HET mice, but not their WT controls, showed decreased neuronal activation (number of c-Fos positive neurons in the nucleus accumbens shell and increased activation in the nucleus accumbens core, both key regions in the expression of LI. Our results add LI to the list of behaviors affected by chronic stress and support a role for GDNF deficits in stress-induced pathological behaviors relevant to schizophrenia and other psychiatric disorders.

  7. Enhanced Sleep Is an Evolutionarily Adaptive Response to Starvation Stress in Drosophila.

    Directory of Open Access Journals (Sweden)

    Melissa E Slocumb

    Full Text Available Animals maximize fitness by modulating sleep and foraging strategies in response to changes in nutrient availability. Wild populations of the fruit fly, Drosophila melanogaster, display highly variable levels of starvation and desiccation resistance that differ in accordance with geographic location, nutrient availability, and evolutionary history. Further, flies potently modulate sleep in response to changes in food availability, and selection for starvation resistance enhances sleep, revealing strong genetic relationships between sleep and nutrient availability. To determine the genetic and evolutionary relationship between sleep and nutrient deprivation, we assessed sleep in flies selected for desiccation or starvation resistance. While starvation resistant flies have higher levels of triglycerides, desiccation resistant flies have enhanced glycogen stores, indicative of distinct physiological adaptations to food or water scarcity. Strikingly, selection for starvation resistance, but not desiccation resistance, leads to increased sleep, indicating that enhanced sleep is not a generalized consequence of higher energy stores. Thermotolerance is not altered in starvation or desiccation resistant flies, providing further evidence for context-specific adaptation to environmental stressors. F2 hybrid flies were generated by crossing starvation selected flies with desiccation selected flies, and the relationship between nutrient deprivation and sleep was examined. Hybrids exhibit a positive correlation between starvation resistance and sleep, while no interaction was detected between desiccation resistance and sleep, revealing that prolonged sleep provides an adaptive response to starvation stress. Therefore, these findings demonstrate context-specific evolution of enhanced sleep in response to chronic food deprivation, and provide a model for understanding the evolutionary relationship between sleep and nutrient availability.

  8. Chronic treatment with paeonol improves endothelial function in mice through inhibition of endoplasmic reticulum stress-mediated oxidative stress.

    Directory of Open Access Journals (Sweden)

    Ker Woon Choy

    Full Text Available Endoplasmic reticulum (ER stress leads to endothelial dysfunction which is commonly associated in the pathogenesis of several cardiovascular diseases. We explored the vascular protective effects of chronic treatment with paeonol (2'-hydroxy-4'-methoxyacetophenone, the major compound from the root bark of Paeonia suffruticosa on ER stress-induced endothelial dysfunction in mice. Male C57BL/6J mice were injected intraperitoneally with ER stress inducer, tunicamycin (1 mg/kg/week for 2 weeks to induce ER stress. The animals were co-administered with or without paeonol (20 mg/kg/oral gavage, reactive oxygen species (ROS scavenger, tempol (20 mg/kg/day or ER stress inhibitor, tauroursodeoxycholic acid (TUDCA, 150 mg/kg/day respectively. Blood pressure and body weight were monitored weekly and at the end of treatment, the aorta was isolated for isometric force measurement. Protein associated with ER stress (GRP78, ATF6 and p-eIF2α and oxidative stress (NOX2 and nitrotyrosine were evaluated using Western blotting. Nitric oxide (NO bioavailability were determined using total nitrate/nitrite assay and western blotting (phosphorylation of eNOS protein. ROS production was assessed by en face dihydroethidium staining and lucigenin-enhanced chemiluminescence assay, respectively. Our results revealed that mice treated with tunicamycin showed an increased blood pressure, reduction in body weight and impairment of endothelium-dependent relaxations (EDRs of aorta, which were ameliorated by co-treatment with either paeonol, TUDCA and tempol. Furthermore, paeonol reduced the ROS level in the mouse aorta and improved NO bioavailability in tunicamycin treated mice. These beneficial effects of paeonol observed were comparable to those produced by TUDCA and tempol, suggesting that the actions of paeonol may involve inhibition of ER stress-mediated oxidative stress pathway. Taken together, the present results suggest that chronic treatment with paeonol preserved

  9. Blocking metabotropic glutamate receptor subtype 5 relieves maladaptive chronic stress consequences.

    Science.gov (United States)

    Peterlik, Daniel; Stangl, Christina; Bauer, Amelie; Bludau, Anna; Keller, Jana; Grabski, Dominik; Killian, Tobias; Schmidt, Dominic; Zajicek, Franziska; Jaeschke, Georg; Lindemann, Lothar; Reber, Stefan O; Flor, Peter J; Uschold-Schmidt, Nicole

    2017-01-01

    Etiology and pharmacotherapy of stress-related psychiatric conditions and somatoform disorders are areas of high unmet medical need. Stressors holding chronic plus psychosocial components thereby bear the highest health risk. Although the metabotropic glutamate receptor subtype 5 (mGlu5) is well studied in the context of acute stress-induced behaviors and physiology, virtually nothing is known about its potential involvement in chronic psychosocial stress. Using the mGlu5 negative allosteric modulator CTEP (2-chloro-4-[2-[2,5-dimethyl-1-[4-(trifluoromethoxy)phenyl]imidazol-4yl]ethynyl]pyridine), a close analogue of the clinically active drug basimglurant - but optimized for rodent studies, as well as mGlu5-deficient mice in combination with a mouse model of male subordination (termed CSC, chronic subordinate colony housing), we demonstrate that mGlu5 mediates multiple physiological, immunological, and behavioral consequences of chronic psychosocial stressor exposure. For instance, CTEP dose-dependently relieved hypothalamo-pituitary-adrenal axis dysfunctions, colonic inflammation as well as the CSC-induced increase in innate anxiety; genetic ablation of mGlu5 in mice largely reproduced the stress-protective effects of CTEP and additionally ameliorated CSC-induced physiological anxiety. Interestingly, CSC also induced an upregulation of mGlu5 in the hippocampus, a stress-regulating brain area. Taken together, our findings provide evidence that mGlu5 is an important mediator for a wide range of chronic psychosocial stress-induced alterations and a potentially valuable drug target for the treatment of chronic stress-related pathologies in man. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Chronic Stress and Neuropathology: Neurochemical, Molecular, and Genetic Factors

    National Research Council Canada - National Science Library

    Koob, George F; Zorrilla, Eric P

    2005-01-01

    ... to selective breeding in the rat. Genetic differences in stress responsiveness in replicate line 1 were associated with differences in anxiety-like behavior, body weight gain and voluntary intake of sweet solutions and ethanol...

  11. Chronic environmental stress enhances tolerance to seasonal gradual warming in marine mussels.

    Directory of Open Access Journals (Sweden)

    Ionan Marigómez

    Full Text Available In global climate change scenarios, seawater warming acts in concert with multiple stress sources, which may enhance the susceptibility of marine biota to thermal stress. Here, the responsiveness to seasonal gradual warming was investigated in temperate mussels from a chronically stressed population in comparison with a healthy one. Stressed and healthy mussels were subjected to gradual temperature elevation for 8 days (1°C per day; fall: 16-24°C, winter: 12-20°C, summer: 20-28°C and kept at elevated temperature for 3 weeks. Healthy mussels experienced thermal stress and entered the time-limited survival period in the fall, became acclimated in winter and exhibited sublethal damage in summer. In stressed mussels, thermal stress and subsequent health deterioration were elicited in the fall but no transition into the critical period of time-limited survival was observed. Stressed mussels did not become acclimated to 20°C in winter, when they experienced low-to-moderate thermal stress, and did not experience sublethal damage at 28°C in summer, showing instead signs of metabolic rate depression. Overall, although the thermal threshold was lowered in chronically stressed mussels, they exhibited enhanced tolerance to seasonal gradual warming, especially in summer. These results challenge current assumptions on the susceptibility of marine biota to the interactive effects of seawater warming and pollution.

  12. [Cholesterolemia and arterial pressure levels. Relationship with different chronic stress configurations].

    Science.gov (United States)

    Bianca de Juárez, M; Iglesias, R; Scoppa, H G; Agnelli, H; Gauna, H F

    2000-01-01

    Several experimental studies refer to the relationship between chronic stress, cholesterolaemia levels and variations in the arterial blood pressure. Our objective is to establish a significant statistical correlation between stress factors, hypertension and hypercholesterolaemia in the studied people. 146 agents were tested among teachers an others employees from the National University of Río Cuarto, who voluntarily went clinical control, reporting data such as arterial pressure, cholesterolaemia, patholgoic records; an standized survey was done considering potentially stress factors, grouped in four different types of stress: (1)-psychoalimentary, (2)-pure psychic, (3)-laboral, (4)-psychofamiliar, giving each of them a value whose addition gane a stress potential factor. The results show that 45.89% of the people studied have hypercholesterolaemia (higher 200 mg% with a mean 237.09 +/- 29.97) being significantly higher (P = 0.001) in the group of employees older than 40 years old., 7.53% of the people showed high arterial pressure, and the 90.90% of this people have hypercholesterolaemia. The hypercholesterolaemic group showed a marked incidence of stress rates higher, with respect to the total people in the four types of stress studied. Significative higher values were observed in the laboral and familiar stress types coinciding with the hypertense group of individuals. According to the collected data we conclude that the relationship between cholesterolaemia, arterial pressure and chronic stress varies with the different types of stress considered, and seem adequate index of stressors levels of studied people.

  13. Oxidative and Anti-Oxidative Stress Markers in Chronic Glaucoma: A Systematic Review and Meta-Analysis

    OpenAIRE

    Benoist d?Azy, C?dric; Pereira, Bruno; Chiambaretta, Fr?d?ric; Dutheil, Fr?d?ric

    2016-01-01

    Chronic glaucoma is a multifactorial disease among which oxidative stress may play a major pathophysiological role. We conducted a systematic review and meta-analysis to evaluate the levels of oxidative and antioxidative stress markers in chronic glaucoma compared with a control group. The PubMed, Cochrane Library, Embase and Science Direct databases were searched for studies reporting oxidative and antioxidative stress markers in chronic glaucoma and in healthy controls using the following k...

  14. Adrenergic Stimulation Mediates Visceral Hypersensitivity to Colorectal Distension following Heterotypic Chronic Stress

    Science.gov (United States)

    Winston, John H.; Xu, Guang-Yin; Sarna, Sushil K.

    2009-01-01

    Background & Aims Chronic stress exacerbates or causes relapse of symptoms such as abdominal pain and cramping in patients with irritable bowel syndrome (IBS). We investigated whether chronic stress increases plasma norepinephrine and sensitizes colon-specific dorsal root ganglion (DRG) neurons by increasing the expression of nerve growth factor (NGF) in the colon wall. Methods Heterotypic chronic stress (HeCS) was induced in male Wistar rats and neurologic and molecular responses were analyzed. Tissues were analyzed for NGF expression. Results HeCS significantly increased the visceromoter response to colorectal distension; expression of NGF increased in colonic muscularis externa and mucosa/submucosa. Rheobase decreased, resting membrane potential was depolarized, and electrogenesis of action potentials increased in colon-specific thoracolumbar DRG neurons. Luminal administration of resiniferatoxin in distal colon, systemic administration of anti-NGF antibody, or inhibition of the NGF receptor TrkA by k252A or antisense oligonucleotides in thoracolumbar DRG blocked the chronic stress-induced visceral hypersensitivity to colorectal distension. Blockade of α1/α2- and β1/β2-adrenergic receptors prevented the stress-induced visceral hypersensitivity and increased expression of NGF in the colon wall. HeCS did not induce any inflammatory response in the colon wall. Conclusion The peripheral stress mediator norepinephrine induces visceral hypersensitivity to colorectal distension in response to HeCS by increasing the expression of NGF in the colon wall, which sensitizes primary afferents in the absence of an inflammatory response. PMID:19800336

  15. Enhanced fear recall and emotional arousal in rats recovering from chronic variable stress.

    Science.gov (United States)

    McGuire, Jennifer; Herman, James P; Horn, Paul S; Sallee, Floyd R; Sah, Renu

    2010-11-02

    Emergence of posttraumatic-like behaviors following chronic trauma is of interest given the rising prevalence of combat-related posttraumatic stress disorder (PTSD). Stress associated with combat usually involves chronic traumatization, composed of multiple, single episode events occurring in an unpredictable fashion. In this study, we investigated whether rats recovering from repeated trauma in the form of chronic variable stress (CVS) express posttraumatic stress-like behaviors and dysregulated neuroendocrine responses. Cohorts of Long-Evans rats underwent a 7 day CVS paradigm followed by behavioral and neuroendocrine testing during early (16 h post CVS) and delayed (7 day) recovery time points. A fear conditioning-extinction-reminder shock paradigm revealed that CVS induces exaggerated fear recall to reminder shock, suggestive of potentiated fear memory. Rats with CVS experience also expressed a delayed expression of fearful arousal under aversive context, however, social anxiety was not affected during post-CVS recovery. Persistent sensitization of the hypothalamic-pituitary-adrenocorticotropic response to a novel acute stressor was observed in CVS exposed rats. Collectively, our data are consistent with the constellation of symptoms associated with posttraumatic stress syndrome, such as re-experiencing, and arousal to fearful contexts. The CVS-recovery paradigm may be useful to simulate trauma outcomes following chronic traumatization that is often associated with repeated combat stress. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. Associations of chronic stress burden, perceived stress, and traumatic stress with cardiovascular disease prevalence and risk factors in the HCHS/SOL Sociocultural Ancillary Study

    Science.gov (United States)

    Gallo, Linda C.; Roesch, Scott C.; Fortmann, Addie L.; Carnethon, Mercedes R.; Penedo, Frank J.; Perreira, Krista; Birnbaum-Weitzman, Orit; Wassertheil-Smoller, Sylvia; Castañeda, Sheila F.; Talavera, Gregory A.; Sotres-Alvarez, Daniela; Daviglus, Martha L.; Schneiderman, Neil; Isasi, Carmen R.

    2015-01-01

    Objective The current study examined multiple stress indicators (chronic, perceived, traumatic) in relation to prevalent coronary heart disease (CHD), stroke, and major cardiovascular disease (CVD) risk factors (i.e., diabetes, dyslipidemia, hypertension, current smoking) in the multi-site Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Sociocultural Ancillary Study (2010–2011). Methods Participants were 5313 men and women, 18–74 years old, representing diverse Hispanic/Latino ethnic backgrounds, who underwent a comprehensive baseline clinical exam and sociocultural exam with measures of stress. Results Chronic stress burden was related to a higher prevalence of CHD after adjusting for sociodemographic, behavioral and biological risk factors [OR (95% CI) = 1.22, (1.10–1.36)] and related to stroke prevalence in the model adjusted for demographic and behavioral factors [OR (95% CI) = 1.26, (1.03–1.55∂)]. Chronic stress was also related to a higher prevalence of diabetes [OR=1.20, (1.11–1.31)] and hypertension [OR=1.10 (1.02–1.19)] in individuals free from CVD (N=4926). Perceived stress [OR=1.03 (1.01–1.05)] and traumatic stress [OR=1.15 (1.05–1.26)] were associated with a higher prevalence of smoking. Participants who reported a greater number of lifetime traumatic events also unexpectedly showed a lower prevalence of diabetes [OR=.89 (.83–.97)] and hypertension [OR=.88 (.82–.93)]. Effects were largely consistent across age and sex groups. Conclusions The study underscores the utility of examining multiple indicators of stress in relation to health, since the direction and consistency of associations may vary across distinct stress conceptualizations. In addition, the study suggests that chronic stress is related to higher CVD risk and prevalence in Hispanics/Latinos, the largest U.S. ethnic minority group. PMID:24979579

  17. Aggravation of chronic stress effects on hippocampal neurogenesis and spatial memory in LPA₁ receptor knockout mice.

    Directory of Open Access Journals (Sweden)

    Estela Castilla-Ortega

    Full Text Available The lysophosphatidic acid LPA₁ receptor regulates plasticity and neurogenesis in the adult hippocampus. Here, we studied whether absence of the LPA₁ receptor modulated the detrimental effects of chronic stress on hippocampal neurogenesis and spatial memory.Male LPA₁-null (NULL and wild-type (WT mice were assigned to control or chronic stress conditions (21 days of restraint, 3 h/day. Immunohistochemistry for bromodeoxyuridine and endogenous markers was performed to examine hippocampal cell proliferation, survival, number and maturation of young neurons, hippocampal structure and apoptosis in the hippocampus. Corticosterone levels were measured in another a separate cohort of mice. Finally, the hole-board test assessed spatial reference and working memory. Under control conditions, NULL mice showed reduced cell proliferation, a defective population of young neurons, reduced hippocampal volume and moderate spatial memory deficits. However, the primary result is that chronic stress impaired hippocampal neurogenesis in NULLs more severely than in WT mice in terms of cell proliferation; apoptosis; the number and maturation of young neurons; and both the volume and neuronal density in the granular zone. Only stressed NULLs presented hypocortisolemia. Moreover, a dramatic deficit in spatial reference memory consolidation was observed in chronically stressed NULL mice, which was in contrast to the minor effect observed in stressed WT mice.These results reveal that the absence of the LPA₁ receptor aggravates the chronic stress-induced impairment to hippocampal neurogenesis and its dependent functions. Thus, modulation of the LPA₁ receptor pathway may be of interest with respect to the treatment of stress-induced hippocampal pathology.

  18. Role of trehalose in heat and desiccation tolerance in the soil bacterium Rhizobium etli

    Directory of Open Access Journals (Sweden)

    Reina-Bueno Mercedes

    2012-09-01

    Full Text Available Abstract Background The compatible solute trehalose is involved in the osmostress response of Rhizobium etli, the microsymbiont of Phaseolus vulgaris. In this work, we reconstructed trehalose metabolism in R. etli, and investigated its role in cellular adaptation and survival to heat and desiccation stress under free living conditions. Results Besides trehalose as major compatible solute, R. etli CE3 also accumulated glutamate and, if present in the medium, mannitol. Putative genes for trehalose synthesis (otsAB/treS/treZY, uptake (aglEFGK/thuEFGK and degradation (thuAB/treC were scattered among the chromosome and plasmids p42a, p42c, p42e, and p42f, and in some instances found redundant. Two copies of the otsA gene, encoding trehalose-6-P-synthase, were located in the chromosome (otsAch and plasmid p42a (otsAa, and the latter seemed to be acquired by horizontal transfer. High temperature alone did not influence growth of R. etli, but a combination of high temperature and osmotic stress was more deleterious for growth than osmotic stress alone. Although high temperature induced some trehalose synthesis by R. etli, trehalose biosynthesis was mainly triggered by osmotic stress. However, an otsAch mutant, unable to synthesize trehalose in minimal medium, showed impaired growth at high temperature, suggesting that trehalose plays a role in thermoprotection of R. etli. Desiccation tolerance by R. etli wild type cells was dependent of high trehalose production by osmotic pre-conditioned cells. Cells of the mutant strain otsAch showed ca. 3-fold lower survival levels than the wild type strain after drying, and a null viability after 4 days storage. Conclusions Our findings suggest a beneficial effect of osmotic stress in R. etli tolerance to desiccation, and an important role of trehalose on the response of R. etli to high temperature and desiccation stress.

  19. Chronic HPA Axis Response to Stress in Temporomandibular Disorder

    Science.gov (United States)

    Lambert, Cynthia Ann; Sanders, Anne; Wilder, Rebecca S.; Slade, Gary D.; Van Uum, Stan; Russell, Evan; Koren, Gideon; Maixner, William

    2014-01-01

    Purpose Perceived stress is associated with temporomandibular disorder (TMD), but whether cortisol levels are elevated in individuals with TMD is unknown. We hypothesized that cortisol concentration, a biomarker of hypothalamic-pituitary-adrenal (HPA) axis function, was elevated in TMD cases relative to controls, and that perceived stress was positively correlated with cortisol concentration. Methods In this case control study, TMD case status was determined by examiners using TMD Research Diagnostic Criteria. Participants (n=116) aged 18 to 59 years were recruited from within a 50 mile radius of the University of North Carolina at Chapel Hill. Following examination, cases (n=45) and controls (n=71) completed the 14-item Perceived Stress Scale using a reference interval of the past 3 months. Approximately 100 strands of hair were cut from the posterior vertex segment of their scalp. The 3 centimeters of hair most proximal to the scalp was analyzed with a commercially available salivary cortisol enzyme immunoassay adapted for hair cortisol. This length corresponds to the last 3 months of systemic HPA axis activity. Results TMD cases perceived higher stress than controls (p=0.001). However, hair cortisol concentration was lower in TMD cases than controls (pstress and hair cortisol concentration (p=0.044). In analysis stratified by case status, the relationship of perceived stress and hair cortisol concentration was non-significant for cases (p=0.169) and controls (p=0.498). Conclusion Despite greater perceived stress, TMD cases had lower hair cortisol concentrations than controls and the 2 measures of stress were weakly and negatively correlated. PMID:23986140

  20. Protective effect of epigallocatechin gallate in murine water-immersion stress model of chronic fatigue syndrome.

    Science.gov (United States)

    Sachdeva, Anand Kamal; Kuhad, Anurag; Tiwari, Vinod; Arora, Vipin; Chopra, Kanwaljit

    2010-06-01

    Chronic fatigue syndrome (CFS) is a specific clinical condition that characterizes unexplained disabling fatigue. In the present study, chronic fatigue was produced in mice by subjecting them to forced swim inside a rectangular jar of specific dimensions for 6 min. daily for 15 days. Epigallocatechin gallate (EGCG; 25, 50 and 100 mg/kg, p.o.) was administered daily 30 min. before forced swim session. Immobility period and post-swim fatigue was assessed on alternate days. On the 16th day, after assessment of various behavioural parameters, mice were killed to harvest the brain, spleen and thymus. There was significant increase in oxidative-nitrosative stress and tumour necrosis factor-alpha levels in the brain of mice subjected to water-immersion stress as compared with naive group. These behavioural and biochemical alterations were restored after chronic treatment with EGCG. The present study points out that EGCG could be of therapeutic potential in the treatment of chronic fatigue.

  1. Response patterns in adult forest trees to chronic ozone stress: identification of variations and consistencies

    International Nuclear Information System (INIS)

    Nunn, Angela J.; Reiter, Ilja M.; Haeberle, Karl-Heinz; Langebartels, Christian; Bahnweg, Guenther; Pretzsch, Hans; Sandermann, Heinrich; Matyssek, Rainer

    2005-01-01

    The responsiveness of adult beech and spruce trees to chronic O 3 stress was studied at a free-air O 3 exposure experiment in Freising/Germany. Over three growing seasons, gas exchange characteristics, biochemical parameters, macroscopic O 3 injury and the phenology of leaf organs were investigated, along with assessments of branch and stem growth as indications of tree performance. To assess response pattern to chronic O 3 stress in adult forest trees, we introduce a new evaluation approach, which provides a comprehensive, readily accomplishable overview across several tree-internal scaling levels, different canopy regions and growing seasons. This new approach, based on a three-grade colour coding, combines statistical analysis and the proficient ability of the 'human eye' in pattern recognition. - Responses of adult forest trees to chronic O 3 stress can be visualized in a survey table applying a three-grade colour coding to each investigated parameter

  2. Evaluation and Adaption of the Trier Inventory for Chronic Stress (TICS) for Assessment in Competitive Sports.

    Science.gov (United States)

    Sallen, Jeffrey; Hirschmann, Florian; Herrmann, Christian

    2018-01-01

    The demands of a career in competitive sports can lead to chronic stress perception among athletes if there is a non-conformity of requirements and available coping resources. The Trier Inventory for Chronic Stress (TICS) (Schulz et al., 2004) is said to be thoroughly validated. Nevertheless, it has not yet been subjected to a confirmatory factor analysis. The present study aims (1) to evaluate the factorial validity of the TICS within the context of competitive sports and (2) to adapt a short version (TICS-36). The total sample consisted of 564 athletes (age in years: M = 19.1, SD = 3.70). The factor structure of the original TICS did not adequately fit the present data, whereas the short version presented a satisfactory fit. The results indicate that the TICS-36 is an economical instrument for gathering interpretable information about chronic stress. For assessment in competitive sports with TICS-36, we generated overall and gender-specific norm values.

  3. Evaluation and Adaption of the Trier Inventory for Chronic Stress (TICS) for Assessment in Competitive Sports

    Science.gov (United States)

    Sallen, Jeffrey; Hirschmann, Florian; Herrmann, Christian

    2018-01-01

    The demands of a career in competitive sports can lead to chronic stress perception among athletes if there is a non-conformity of requirements and available coping resources. The Trier Inventory for Chronic Stress (TICS) (Schulz et al., 2004) is said to be thoroughly validated. Nevertheless, it has not yet been subjected to a confirmatory factor analysis. The present study aims (1) to evaluate the factorial validity of the TICS within the context of competitive sports and (2) to adapt a short version (TICS-36). The total sample consisted of 564 athletes (age in years: M = 19.1, SD = 3.70). The factor structure of the original TICS did not adequately fit the present data, whereas the short version presented a satisfactory fit. The results indicate that the TICS-36 is an economical instrument for gathering interpretable information about chronic stress. For assessment in competitive sports with TICS-36, we generated overall and gender-specific norm values. PMID:29593611

  4. A Daily Diary Approach to the Examination of Chronic Stress, Daily Hassles and Safety Perceptions in Hospital Nursing.

    Science.gov (United States)

    Louch, Gemma; O'Hara, Jane; Gardner, Peter; O'Connor, Daryl B

    2017-12-01

    Stress is a significant concern for individuals and organisations. Few studies have explored stress, burnout and patient safety in hospital nursing on a daily basis at the individual level. This study aimed to examine the effects of chronic stress and daily hassles on safety perceptions, the effect of chronic stress on daily hassles experienced and chronic stress as a potential moderator. Utilising a daily diary design, 83 UK hospital nurses completed three end-of-shift diaries, yielding 324 person days. Hassles, safety perceptions and workplace cognitive failure were measured daily, and a baseline questionnaire included a measure of chronic stress. Hierarchical multivariate linear modelling was used to analyse the data. Higher chronic stress was associated with more daily hassles, poorer perceptions of safety and being less able to practise safely, but not more workplace cognitive failure. Reporting more daily hassles was associated with poorer perceptions of safety, being less able to practise safely and more workplace cognitive failure. Chronic stress did not moderate daily associations. The hassles reported illustrate the wide-ranging hassles nurses experienced. The findings demonstrate, in addition to chronic stress, the importance of daily hassles for nurses' perceptions of safety and the hassles experienced by hospital nurses on a daily basis. Nurses perceive chronic stress and daily hassles to contribute to their perceptions of safety. Measuring the number of daily hassles experienced could proactively highlight when patient safety threats may arise, and as a result, interventions could usefully focus on the management of daily hassles.

  5. Behavioral phenotype predicts physiological responses to chronic stress in proactive and reactive birds.

    Science.gov (United States)

    Pusch, Elizabeth A; Bentz, Alexandra B; Becker, Daniel J; Navara, Kristen J

    2018-01-01

    Animal species display significant variation in personality traits among individuals, and two main coping styles have been identified and termed "proactive" and "reactive". Further, these coping styles appear to correlate directly with the strength of the physiological stress response exhibited by those individuals. In our study system, white laying hens are reactive, flighty, and exhibit large hormonal and behavioral responses to acute stress, while brown laying hens are proactive, exploratory, and exhibit low hormonal and behavioral responses to acute stress. The objective of the current study was to determine if personality type also corresponds to differences in multiple measures of stress when birds are subjected to a chronic stressor. We tested the responses of hens to chronic stress applied by providing feed according to an unpredictable schedule for 14 days, and measured corticosterone concentrations in circulation, expression of heat shock proteins (HSPs), molecules known to protect cells in response to stress, and the ratios of heterophils:lymphocytes in blood, two immune cells known to change in quantity in circulation during chronic stress. We predicted that white hens would show greater physiological responses to the chronic stress treatment. Plasma corticosterone levels significantly increased after 7 days of treatment and returned to baseline levels on day 14, but did not differ significantly between strains. H:L ratios, on the other hand, were significantly elevated by day 7 of treatment, and increased significantly more in brown hens than white. HSP70 and HSP90 expression levels were significantly higher after stress began in white hens than brown. Our results showed that brown hens were more reactive in one response (H:L ratios) while white hens were more reactive in another (HSP expression). These different reactions to the same stressor may represent different strategies for dealing with the same stressor. Copyright © 2017. Published by

  6. Effects of chronic stress on the auditory system and fear learning: an evolutionary approach.

    Science.gov (United States)

    Dagnino-Subiabre, Alexies

    2013-01-01

    Stress is a complex biological reaction common to all living organisms that allows them to adapt to their environments. Chronic stress alters the dendritic architecture and function of the limbic brain areas that affect memory, learning, and emotional processing. This review summarizes our research about chronic stress effects on the auditory system, providing the details of how we developed the main hypotheses that currently guide our research. The aims of our studies are to (1) determine how chronic stress impairs the dendritic morphology of the main nuclei of the rat auditory system, the inferior colliculus (auditory mesencephalon), the medial geniculate nucleus (auditory thalamus), and the primary auditory cortex; (2) correlate the anatomic alterations with the impairments of auditory fear learning; and (3) investigate how the stress-induced alterations in the rat limbic system may spread to nonlimbic areas, affecting specific sensory system, such as the auditory and olfactory systems, and complex cognitive functions, such as auditory attention. Finally, this article gives a new evolutionary approach to understanding the neurobiology of stress and the stress-related disorders.

  7. Biological stress systems, adverse life events and the onset of chronic multisite musculoskeletal pain : a six-year cohort study

    NARCIS (Netherlands)

    Generaal, E.; Vogelzangs, N.; Macfarlane, G.J.; Geenen, R.; de Geus, E.; Smit, J.H.; Penninx, B.W.; Dekker, J.

    2015-01-01

    Background Dysregulated biological stress systems and adverse life events, both independently and in interaction, have been hypothesized to initiate chronic pain. Objectives We examine whether (i) function of biological stress systems, (ii) adverse life events, and (iii) their combination predict

  8. Effects of dietary L-tryptophan supplementation on intestinal response to chronic unpredictable stress in broilers.

    Science.gov (United States)

    Yue, Yunshuang; Guo, Yuming; Yang, Ying

    2017-07-01

    Stress has been recognized as a critical risk factor for gastrointestinal diseases in both humans and animals. However, nutritional strategies to attenuate stress-induced intestinal barrier function and underlying mechanisms remain largely unknown. This study tested the hypothesis that L-tryptophan enhanced intestinal barrier function by regulating mucosal serotonin metabolism in chronic unpredictable stress-exposed broilers. One-day-old male broilers (Arbor Acres) were fed a basal diet supplemented with or without L-tryptophan in the absence or presence of chronic unpredictable stress. Feed intake, body weight gain, plasma corticosterone and 5-hydroxytryptamine (5-HT), intestinal permeability, mucosal secretory IgA (sIgA), and mRNA levels for tryptophan hydroxylase 1 (TPH1), IL-1β, IL-6, TNF-α, IL-10, protein abundance for claudin-1, occludin, and ZO-1 were determined. Stress exposure led to elevated plasma corticosterone (P tryptophan supplementation. Western blot analysis showed that stress exposure resulted in decreased protein abundance for occludin, claudin-1, and ZO-1, which was attenuated by L-tryptophan. mRNA levels for IL-1β, IL-6, and TNF-α were increased, but those for IL-10 were decreased, in the jejunal tissue of broilers subjected to stress. This effect of stress on cytokine expression was abolished by L-tryptophan treatment. The effects of stress were associated with decreased plasma concentration of 5-HT (P Tryptophan supplementation markedly attenuated stress-induced alterations in 5-HT and TPH1 mRNA level in jejunal tissues of broilers. Collectively, these results indicate that L-tryptophan supplementation alleviates chronic unpredictable stress-induced intestinal barrier dysfunction by regulating 5-HT metabolism in broilers.

  9. Chronic fatigue and strategies of coping with occupational stress in police officers

    Directory of Open Access Journals (Sweden)

    Ewa Stępka

    2014-04-01

    Full Text Available Background: Work as one of the most important activities in human life is related to stressful and difficult situations. Police officers make one of the many occupational groups that are particularly threatened by contact with a number of stressors. Therefore, their strategies of coping with stress are particularly important, because they play an important role in their functioning at work. The nature of the service as well as shift work and psychological costs incurred by police officers contribute to the emergence of chronic fatigue. The aim of this study was to evaluate the level of chronic fatigue in police officers and its relationship with the strategies of coping with occupational stress. Material and Methods: A group of 61 police officers was examined. The following research methods were used: 1 Latack Coping Scale examining stress coping strategies at work (positive thinking, direct action, avoidance/resignation, seeking help, alcohol or stimulants use; 2 Mood Assessment Questionnaire CIS-20R examining the level of chronic fatigue and its components (subjective feeling of fatigue, impaired attention and concentration, reduced motivation, reduced activity; 3 Personal questionnaire providing socio-demographic data. Results: It was found that the level of chronic fatigue in the group of the examined police officers was high (sten 8th. The most often used strategies of coping with stress were direct action and positive thinking, and the least often used strategy was the use of alcohol and stimulants. A significant negative correlation between the general level of chronic fatigue and the avoidance/ resignation strategy was found. Conclusions: The results indicate that chronic fatigue is a problem affecting police officers and it is related to the stress coping strategies used. Med Pr 2014;65(2:229–238

  10. [Chronic fatigue and strategies of coping with occupational stress in police officers].

    Science.gov (United States)

    Stepka, Ewa; Basińska, Małgorzata Anna

    2014-01-01

    Work as one of the most important activities in human life is related to stressful and difficult situations. Police officers make one of the many occupational groups that are particularly threatened by contact with a number of stressors. Therefore, their strategies of coping with stress are particularly important, because they play an important role in their functioning at work. The nature of the service as well as shift work and psychological costs incurred by police officers contribute to the emergence of chronic fatigue. The aim of this study was to evaluate the level of chronic fatigue in police officers and its relationship with the strategies of coping with occupational stress. A group of 61 police officers was examined. The following research methods were used: 1) Latack Coping Scale examining stress coping strategies at work (positive thinking, direct action, avoidance/resignation, seeking help, alcohol or stimulants use); 2) Mood Assessment Questionnaire CIS-20R examining the level of chronic fatigue and its components (subjective feeling of fatigue, impaired attention and concentration, reduced motivation, reduced activity); 3) Personal questionnaire providing socio-demographic data. It was found that the level of chronic fatigue in the group of the examined police officers was high (sten 8th). The most often used strategies of coping with stress were direct action and positive thinking, and the least often used strategy was the use of alcohol and stimulants. A significant negative correlation between the general level of chronic fatigue and the avoidance/resignation strategy was found. The results indicate that chronic fatigue is a problem affecting police officers and it is related to the stress coping strategies used.

  11. Update in the methodology of the chronic stress paradigm: internal control matters

    Directory of Open Access Journals (Sweden)

    Boyks Marco

    2011-04-01

    Full Text Available Abstract To date, the reliability of induction of a depressive-like state using chronic stress models is confronted by many methodological limitations. We believe that the modifications to the stress paradigm in mice proposed herein allow some of these limitations to be overcome. Here, we discuss a variant of the standard stress paradigm, which results in anhedonia. This anhedonic state was defined by a decrease in sucrose preference that was not exhibited by all animals. As such, we propose the use of non-anhedonic, stressed mice as an internal control in experimental mouse models of depression. The application of an internal control for the effects of stress, along with optimized behavioural testing, can enable the analysis of biological correlates of stress-induced anhedonia versus the consequences of stress alone in a chronic-stress depression model. This is illustrated, for instance, by distinct physiological and molecular profiles in anhedonic and non-anhedonic groups subjected to stress. These results argue for the use of a subgroup of individuals who are negative for the induction of a depressive phenotype during experimental paradigms of depression as an internal control, for more refined modeling of this disorder in animals.

  12. Update in the methodology of the chronic stress paradigm: internal control matters.

    Science.gov (United States)

    Strekalova, Tatyana; Couch, Yvonne; Kholod, Natalia; Boyks, Marco; Malin, Dmitry; Leprince, Pierre; Steinbusch, Harry Mw

    2011-04-27

    To date, the reliability of induction of a depressive-like state using chronic stress models is confronted by many methodological limitations. We believe that the modifications to the stress paradigm in mice proposed herein allow some of these limitations to be overcome. Here, we discuss a variant of the standard stress paradigm, which results in anhedonia. This anhedonic state was defined by a decrease in sucrose preference that was not exhibited by all animals. As such, we propose the use of non-anhedonic, stressed mice as an internal control in experimental mouse models of depression. The application of an internal control for the effects of stress, along with optimized behavioural testing, can enable the analysis of biological correlates of stress-induced anhedonia versus the consequences of stress alone in a chronic-stress depression model. This is illustrated, for instance, by distinct physiological and molecular profiles in anhedonic and non-anhedonic groups subjected to stress. These results argue for the use of a subgroup of individuals who are negative for the induction of a depressive phenotype during experimental paradigms of depression as an internal control, for more refined modeling of this disorder in animals.

  13. Detection of Chronic Stress in Corals Exposed to Invasive Algae Mats

    Science.gov (United States)

    Sindorf, V.; Richmond, R. H.

    2016-02-01

    Invasive algae mats like those common in Kāne`ohe Bay, O`ahu, are known to negatively affect coral health and recruitment through a variety of mechanisms including shading, abrasion, oxidative stress, and allelopathic interactions. Algae-induced stress has thus far been documented through changes in photosynthetic efficiency and coloration (bleaching) of the coral, and these studies have been largely accomplished through experimental manipulation, inflicting acute stress on coral nubbins. Few studies have investigated the stress response of corals chronically exposed to algae-induced stress, and fewer have used molecular methods to demonstrate and quantify this stress. This study focuses on Porites compressa colonies in chronic contact with the invasive alga Kappaphycus alvarezii on naturally occurring patch reefs in Kāne`ohe Bay, O`ahu, Hawai`i. Our findings demonstrate the ability of these methods to detect and monitor coral stress before outward signs of stress such as bleaching are evident, which will allow for more proactive management of at-risk coral reef ecosystems. The differential expression of genes and gene products (proteins) between corals in long-term contact with invasive algae and those not in contact with algae highlight the specific metabolic pathways involved in algae-induced stress response of corals and lays the foundation for understanding mechanisms of acclimation and resilience towards these stressors.

  14. Curcumin, a polyphenolic antioxidant, attenuates chronic fatigue syndrome in murine water immersion stress model.

    Science.gov (United States)

    Gupta, Amit; Vij, Garima; Sharma, Sameer; Tirkey, Naveen; Rishi, Praveen; Chopra, Kanwaljit

    2009-01-01

    Chronic fatigue syndrome, infection and oxidative stress are interrelated in epidemiological case studies. However, data demonstrating scientific validation of epidemiological claims regarding effectiveness of nutritional supplements for chronic fatigue syndrome are lacking. This study is designed to evaluate the effect of natural polyphenol, curcumin, in a mouse model of immunologically induced fatigue, where purified lipopolysaccharide (LPS) and Brucella abortus (BA) antigens were used as immunogens. The assessment of chronic fatigue syndrome was based on chronic water-immersion stress test for 10 min daily for 19 days and the immobility time was taken as the marker of fatigue. Mice challenged with LPS or BA for 19 days showed significant increase in the immobility time and hyperalgesia on day 19, as well as marked increase in serum tumor necrosis factor-alpha (TNF-alpha) levels. Concurrent treatment with curcumin resulted in significantly decreased immobility time as well as hyperalgesia. There was significant attenuation of oxidative stress as well as TNF-alpha levels. These findings strongly suggest that during immunological activation, there is significant increase in oxidative stress and curcumin can be a valuable option in the treatment of chronic fatigue syndrome.

  15. Role of anuloma viloma pranayama in reducing stress in chronic alcoholics

    International Nuclear Information System (INIS)

    Kumar, L.R.

    2011-01-01

    Despite improved clinical care, heightened public awareness and wide spread use of health innovations, alcoholism remains a leading cause of death in many parts of the world. Chronic alcoholics suffer from stress and multitude of symptoms. The progressive addiction to alcohol will gradually nullify all other interests in the patient's life so that a deterioration of the physical, psychological, social, cultural and religious values takes place. The role of yoga in healing asthma, arthritis and other disorders has been known. Methods: Breathing technique (Anuloma Viloma Pranayama) was taught to chronic alcoholics. Using galvanic skin resistance, stress levels were measured before and after anuloma viloma yoga in controls and chronic alcoholics. Results: Reduced stress levels were noted using the galvanic skin resistance in both controls and chronic alcoholics after yogic breathing. Conclusion: There is a promising effect of simple yoga techniques in organising effective rehabilitation and treatment programmes to reduce stress in chronic alcoholics. This study would help to chart out a better management programme for enhancing relapse and alleviate the symptoms. (author)

  16. Desiccant cooling: State-of-the-art assessment

    Energy Technology Data Exchange (ETDEWEB)

    Pesaran, A.A.; Penney, T.R.; Czanderna, A.W.

    1992-10-01

    The objectives of this document are to present an overview of the work accomplished to date on desiccant cooling to provide assessment of the state of the art of desiccant cooling technology in the field of desiccant material dehumidifier components, desiccant systems, and models. The report also discusses the factors that affect the widespread acceptance of desiccant cooling technology. This report is organized as follows. First, a basic description and historical overview of desiccant cooling technology is provided. Then, the recent research and development (R&D) program history (focusing on DOE`s funded efforts) is discussed. The status of the technology elements (materials, components, systems) is discussed in detail and a preliminary study on the energy impact of desiccant technology is presented. R&D needs for advancing the technology in the market are identified. The National Renewable Energy Laboratory`s unique desiccant test facilities and their typical outputs are described briefly. Finally, the results of a comprehensive literature search on desiccant cooling are presented in a bibliography. The bibliography contains approximately 900 citations on desiccant cooling.

  17. Desiccant cooling: State-of-the-art assessment

    Energy Technology Data Exchange (ETDEWEB)

    Pesaran, A.A.; Penney, T.R.; Czanderna, A.W.

    1992-10-01

    The objectives of this document are to present an overview of the work accomplished to date on desiccant cooling to provide assessment of the state of the art of desiccant cooling technology in the field of desiccant material dehumidifier components, desiccant systems, and models. The report also discusses the factors that affect the widespread acceptance of desiccant cooling technology. This report is organized as follows. First, a basic description and historical overview of desiccant cooling technology is provided. Then, the recent research and development (R D) program history (focusing on DOE's funded efforts) is discussed. The status of the technology elements (materials, components, systems) is discussed in detail and a preliminary study on the energy impact of desiccant technology is presented. R D needs for advancing the technology in the market are identified. The National Renewable Energy Laboratory's unique desiccant test facilities and their typical outputs are described briefly. Finally, the results of a comprehensive literature search on desiccant cooling are presented in a bibliography. The bibliography contains approximately 900 citations on desiccant cooling.

  18. Stress Management as an Adjunct to Physical Therapy for Chronic Neck Pain

    Science.gov (United States)

    Bruflat, Angela K.; Balter, Jaclyn E.; McGuire, Denise; Fethke, Nathan B.

    2012-01-01

    Background and Purpose Chronic neck pain is prevalent in the workplace. Research suggests that psychosocial stress may contribute to the development of neck pain by causing excessive or prolonged muscle activity in some individuals. The purpose of this case report is to describe the rationale, development, and implementation of stress management as an adjunct to standard physical therapist management of chronic neck pain in a female office worker who responded to psychosocial stress with elevated muscle activity prior to treatment. Case Description A 44-year-old female office employee with an 8-year history of chronic neck pain participated in this case report. The patient was selected from a group of research participants who demonstrated elevated electromyographic (EMG) activity of the trapezius muscle in response to simulated occupational stressors. The multidisciplinary intervention consisted of 8 physical therapy sessions, supplemented by 8 stress management sessions that included EMG biofeedback and psychotherapy to facilitate muscle relaxation. Outcomes Neck disability decreased by 50%, trait anxiety decreased by 21%, and the duration of trapezius muscle rest in the workplace increased by 56% immediately after the 8-week intervention. These improvements were maintained 6 months after treatment, and the patient reported a complete absence of neck disability at the 2-year follow-up assessment. Discussion A sustained reduction in neck disability was observed for a patient with chronic neck pain after participating in a multidisciplinary intervention that combined physical therapy and stress management approaches to facilitate muscle relaxation in the workplace. Future clinical trials are needed to assess whether stress management is a useful adjunct therapy for patients with chronic neck pain who show elevated muscle activity in response to psychosocial stress. PMID:22700538

  19. Experimental Analysis on Solar Desiccant Air Conditioner

    OpenAIRE

    Dr. U. V. Kongre, C. M. Singh, A. B. Biswas

    2014-01-01

    The experiment investigated and evaluated the feasibility of an solar desiccant air conditioner. Its effectiveness as a possible air conditioner option used in household air conditioner or as an energy efficient and environmentally friendly alternative to conventional air conditioning units used in houses are evaluated. A solar water heater was used as heat gain. The model utilizes the technology of solar air conditioner system. The purpose in the long term wou...

  20. Heterogeneity in Desiccated Solutions: Implications for Biostabilization

    OpenAIRE

    Ragoonanan, Vishard; Aksan, Alptekin

    2007-01-01

    Biopreservation processes such as freezing and drying inherently introduce heterogeneity. We focused on exploring the mechanisms responsible for heterogeneity in isothermal, diffusively dried biopreservation solutions that contain a model protein. The biopreservation solutions used contained trehalose (a sugar known for its stabilization effect) and salts (LiCl, NaCl, MgCl2, and CaCl2). Performing Fourier transform infrared spectroscopy analysis on the desiccated droplets, spatial distributio...

  1. Effects of the chronic restraint stress induced depression on reward-related learning in rats.

    Science.gov (United States)

    Xu, Pan; Wang, Kezhu; Lu, Cong; Dong, Liming; Chen, Yixi; Wang, Qiong; Shi, Zhe; Yang, Yanyan; Chen, Shanguang; Liu, Xinmin

    2017-03-15

    Chronic mild or unpredictability stress produces a persistent depressive-like state. The main symptoms of depression include weight loss, despair, anhedonia, diminished motivation and mild cognition impairment, which could influence the ability of reward-related learning. In the present study, we aimed to evaluate the effects of chronic restraint stress on the performance of reward-related learning of rats. We used the exposure of repeated restraint stress (6h/day, for 28days) to induce depression-like behavior in rats. Then designed tasks including Pavlovian conditioning (magazine head entries), acquisition and maintenance of instrumental conditioning (lever pressing) and goal directed learning (higher fixed ratio schedule of reinforcement) to study the effects of chronic restraint stress. The results indicated that chronic restraint stress influenced rats in those aspects including the acquisition of a Pavlovian stimulus-outcome (S-O) association, the formation and maintenance of action-outcome (A-O) causal relation and the ability of learning in higher fixed ratio schedule. In conclusion, depression could influence the performances in reward-related learning obviously and the series of instrumental learning tasks may have potential as a method to evaluate cognitive changes in depression. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Chronic stress impairs learning and hippocampal cell proliferation in senescence-accelerated prone mice.

    Science.gov (United States)

    Yan, Weihong; Zhang, Ting; Jia, Weiping; Sun, Xiaojiang; Liu, Xueyuan

    2011-02-25

    Chronic stress can induce cognitive impairment. It is unclear whether a higher susceptibility to chronic stress is associated with the progression of pathological brain aging. Senescence-accelerated prone mouse 8 (SAMP8) is a naturally occurring animal model of accelerated brain aging. Senescence-accelerated resistant mouse 1 (SAMR1) is usually used as the normal control. In this study, we examined the effects of chronic restraint stress (CRS) on learning in the Y-maze, hippocampal cell proliferation, and the expression of brain-derived neurotrophic factor (BDNF) in the hippocampus of 4-month-old SAMP8 and SAMR1. The results showed that exposure to CRS impaired learning and hippocampal cell proliferation in SAMP8 and SAMR1 but to a much greater extent in SAMP8. Furthermore, CRS significantly decreased the expression of BDNF protein and mRNA in the hippocampus of SAMP8 and SAMR1. These data indicated that SAMP8 is more sensitive to the deleterious effects of CRS on learning than SAMR1. A greater decrease in hippocampal cell proliferation caused by chronic stress may be part of the underlying mechanism for the more severe learning deficit observed in SAMP8. In addition, our findings suggested a role of BDNF in the stress-induced impairment of learning and hippocampal cell proliferation in both strains. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  3. Influencing Genomic Change and Cancer Disparities through Neighborhood Chronic Toxic Stress Exposure: A Research Framework.

    Science.gov (United States)

    DeGuzman, Pamela B; Schminkey, Donna L

    2016-11-01

    Black Americans have disproportionately higher incidence and mortality rates for many cancers. These disparities may be related to genomic changes that occur from exposure to chronic toxic stress and may result from conditions associated with living in racially segregated neighborhoods with high rates of concentrated poverty. The purpose of this article is to present a nursing research framework for developing and testing neighborhood-level interventions that have the potential to mitigate exposure to neighborhood-associated chronic toxic stress, improve individual-level genomic sequelae and cancer outcomes, and reduce cancer health disparities of Black Americans. Public health nursing researchers should collaborate with local officials to determine ways to reduce neighborhood-level stress. Intermediate outcomes can be measured using genomic or other stress biomarkers, and long-term outcomes can be measured by evaluating population-level cancer incidence and mortality. © 2016 Wiley Periodicals, Inc.

  4. Differential microstructural alterations in rat cerebral cortex in a model of chronic mild stress depression

    DEFF Research Database (Denmark)

    Khan, Ahmad Raza; Kroenke, Christopher D; Wiborg, Ove

    2018-01-01

    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...

  5. Desiccation resistance of wild and mass-reared Bactrocera tryoni (Diptera: Tephritidae).

    Science.gov (United States)

    Weldon, C W; Yap, S; Taylor, P W

    2013-12-01

    In pest management programmes that incorporate the sterile insect technique (SIT), the ability of mass-reared insects to tolerate dry conditions may influence their survival after release in the field. In the present study, desiccation resistance of adult mass-reared Queensland fruit flies, Bactrocera tryoni (Frogatt) (Diptera: Tephritidae), that are routinely released in SIT programmes was compared with that of wild flies at 1, 10 and 20 days after adult eclosion. Under dry conditions without access to food or water, longevity of mass-reared B. tryoni was significantly less than that of their wild counterparts. Desiccation resistance of mass-reared flies declined monotonically with age, but this was not the case for wild flies. The sharp decline in desiccation resistance of mass-reared flies as they aged was likely explained by decreased dehydration tolerance. As in an earlier study, desiccation resistance of females was significantly lower than that of males but this was particularly pronounced in mass-reared females. Female susceptibility to dry conditions corresponded with declining dehydration tolerance with age and associated patterns of reproductive development, which suggests that water content of their oocyte load is not available for survival during periods of water stress.

  6. Effects of desiccation and starvation on thermal tolerance and the heat-shock response in forest ants.

    Science.gov (United States)

    Nguyen, Andrew D; DeNovellis, Kerri; Resendez, Skyler; Pustilnik, Jeremy D; Gotelli, Nicholas J; Parker, Joel D; Cahan, Sara Helms

    2017-12-01

    Temperature increases associated with global climate change are likely to be accompanied by additional environmental stressors such as desiccation and food limitation, which may alter how temperature impacts organismal performance. To investigate how interactions between stressors influence thermal tolerance in the common forest ant, Aphaenogaster picea, we compared the thermal resistance of workers to heat shock with and without pre-exposure to desiccation or starvation stress. Knockdown (KD) time at 40.5 °C of desiccated ants was reduced 6% compared to controls, although longer exposure to desiccation did not further reduce thermal tolerance. Starvation, in contrast, had an increasingly severe effect on thermal tolerance: at 21 days, average KD time of starved ants was reduced by 65% compared to controls. To test whether reduction in thermal tolerance results from impairment of the heat-shock response, we measured basal gene expression and transcriptional induction of two heat-shock proteins (hsp70 and hsp40) in treated and control ants. We found no evidence that either stressor impaired the Hsp response: both desiccation and starvation slightly increased basal Hsp expression under severe stress conditions and did not affect the magnitude of induction under heat shock. These results suggest that the co-occurrence of multiple environmental stressors predicted by climate change models may make populations more vulnerable to future warming than is suggested by the results of single-factor heating experiments.

  7. Salivary Biomarkers of Chronic Psychosocial Stress and CVD Risks: A Systematic Review.

    Science.gov (United States)

    An, Kyungeh; Salyer, Jeanne; Brown, Roy E; Kao, Hsueh-Fen Sabrina; Starkweather, Angela; Shim, Insop

    2016-05-01

    The use of salivary biomarkers in stress research is increasing, and the precision and accuracy with which researchers are able to measure these biomarkers have dramatically improved. Chronic psychosocial stress is often linked to the pathogenesis of cardiovascular disease (CVD). Salivary biomarkers represent a noninvasive biological method of characterizing the stress phenomenon that may help to more fully describe the mechanism by which stress contributes to the pathogenesis and outcomes of CVD. We conducted a systematic review of 40 research articles to identify the salivary biomarkers researchers have most commonly used to help describe the biological impact of chronic psychosocial stress and explore its associations with CVD risk. We address strengths and weaknesses of specimen collection and measurement. We used PubMed, CINAHL, EBSCOhost, Web of Science, BIOSIS Previews, Biological Sciences (ProQuest), and Dissertations/Theses (ProQuest) to retrieve 387 initial articles. Once we applied our inclusion/exclusion criteria to specifically target adult human studies dealing with chronic stress rather than acute/laboratory-induced stress, 40 studies remained, which we synthesized using Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Cortisol was the biomarker used most frequently. Sources of psychosocial stress included job strain, low socioeconomic status, and environmental factors. Overall, psychosocial stress was associated with CVD risks such as vascular pathology (hypertension, blood pressure fluctuation, and carotid artery plaque) as well as metabolic factors such as abnormal blood glucose, dyslipidemia, and elevated cardiac enzymes. Diverse salivary biomarkers have been useful in stress research, particularly when linked to CVD risks. © The Author(s) 2015.

  8. Chronic stress-induced oxidative damage and hyperlipidemia are accompanied by atherosclerotic development in rats.

    Science.gov (United States)

    Devaki, M; Nirupama, R; Yajurvedi, H N

    2013-03-01

    Although stress-induced hyperlipidemia and increased oxidative stress have been reported and implicated in etiology of atherosclerosis, experimental evidence for stress-induced atherosclerotic development concomitant with these alterations is lacking. In this study, exposure of adult male albino Wistar rats (Rattus norvegicus) to restraint for 1 h and after a gap of 4 h to forced swimming for 15 min every day for 2, 4, or 24 weeks resulted in a duration of exposure-dependent hyperlipidemia as shown by significant increases in concentrations of blood cholesterol, low-density lipoproteins, and triglycerides and decrease in high-density lipoprotein concomitant with increased oxidative stress as indicated by decrease in hepatic antioxidant enzyme activities and increase in lipid peroxidation in the liver, kidney, and heart. These alterations were accompanied by development of fibrous layer, formation of foam cells, reduction in elastic fibers, and accumulation of Oil-Red-O-positive lipid droplets in the intima of thoracic aorta following 24 weeks of stress exposure, but not after 4 weeks. The study demonstrates for the first time that (i) chronic stress-induced hyperlipidemia and oxidative damage are coupled with atherosclerotic development in rats fed with normal diet and (ii) chronic stress effects prevail even after the cessation of stress exposure as indicated by high concentration of blood cholesterol and reduced hepatic superoxide dismutase activity 20 weeks after 2 or 4 weeks of stress. This study exemplifies long-term allostatic regulation leading to a pathological state, with long-term hyperlipidemia and oxidative damage from chronic stress resulting in atherosclerosis.

  9. Effect of Xiaoyaosan Decoction on Learning and Memory Deficit in Rats Induced by Chronic Immobilization Stress

    OpenAIRE

    Meng, Zhen-Zhi; Chen, Jia-Xu; Jiang, You-Ming; Zhang, Han-Ting

    2013-01-01

    Xiaoyaosan (XYS) decoction is a famous prescription which can protect nervous system from stress and treat liver stagnation and spleen deficiency syndrome (LSSDS). In this experiment, we observed the effect of XYS decoction on chronic immobilization stress (CIS) induced learning and memory deficit in rats from behaviors and changes of proteins in hippocampus. We used XYS decoction to treat CIS induced learning and memory deficit in rats with rolipram as positive control, used change of body w...

  10. New Pathogenic Concepts and Therapeutic Approaches to Oxidative Stress in Chronic Kidney Disease

    DEFF Research Database (Denmark)

    Pedraza-Chaverri, José; Sánchez-Lozada, Laura G; Osorio-Alonso, Horacio

    2016-01-01

    In chronic kidney disease inflammatory processes and stimulation of immune cells result in overproduction of free radicals. In combination with a reduced antioxidant capacity this causes oxidative stress. This review focuses on current pathogenic concepts of oxidative stress for the decline...... of kidney function and development of cardiovascular complications. We discuss the impact of mitochondrial alterations and dysfunction, a pathogenic role for hyperuricemia, and disturbances of vitamin D metabolism and signal transduction. Recent antioxidant therapy options including the use of vitamin D...

  11. The appraisal of chronic stress and the development of the metabolic syndrome

    DEFF Research Database (Denmark)

    Bergmann, N; Gyntelberg, F; Faber, J

    2014-01-01

    studies supported perceived stress and distress as risk factors for the development of DM2 among men, but not among women, while WS was generally not supported as a risk factor among neither men nor women; iv) hypertension: marital stress and perceived stress might have an influence on blood pressure (BP...... the studies on work-related stress (WS) showed conflicting results; ii) dyslipidemi: too few studies on psychosocial stress as a risk factor for dyslipidemia were available to draw a conclusion; however, a trend toward a positive association was present; iii) type 2 diabetes mellitus (DM2): prospective......), while no association was found regarding distress. Evaluating WS the results were equivocal and indicated that different types of WS affected the BP differently between men and women. In conclusion, a longitudinal association between chronic psychosocial stress and the development of MES seems present...

  12. Social overcrowding as a chronic stress model that increases adiposity in mice.

    Science.gov (United States)

    Lin, En-Ju D; Sun, Meng; Choi, Eugene Y; Magee, Daniel; Stets, Colin W; During, Matthew J

    2015-01-01

    Stress is a widely recognized risk factor for psychiatric and metabolic disorders. A number of animal models utilizing various stressors have been developed to facilitate our understanding in the pathophysiology of stress-related dysfunctions. The most commonly used chronic stress paradigms include the unpredictable chronic mild stress paradigm, the social defeat paradigm and the social deprivation paradigm. Here we assess the potential of social crowding as an alternative chronic stress model to study the effects on affective behaviors and metabolic disturbances. Ten-week-old male C57BL/6 mice were housed in groups of four (control) or eight (social crowding; SC) in standard cage for 9 weeks. Exploration, anxiety- and depressive-like behaviors were assessed in the open field test, the elevated T-maze, the novelty-suppressed feeding test and the forced swim test. SC mice exhibited a modest anxiety-like phenotype without change in depressive-like behaviors. Nine weeks of social crowding did not affect the body weight, but robustly increased adiposity as determined by increased mass of fat depots. Consistent with the increased fat content, serum leptin was markedly elevated in the SC mice. Specific changes in gene expression were also observed in the hypothalamus and the white adipose tissue following SC housing. Our study demonstrates the potential of social crowding as an alternative model for the study of stress-related metabolic and behavioral dysfunctions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Effects on immune responses by chronic stress are modulated by aging.

    Science.gov (United States)

    Odio, M; Brodish, A; Ricardo, M J

    1987-09-01

    Male Fischer-344 rats at 5, 11, and 18 months of age were exposed to chronic stress for 6 months and subsequently allowed a 1-month interval with no stress before examination of splenic lymphocyte proliferative responses, IL-2 secretion by T cells, and NK cell activity in stressed and age- and sex-matched control animals. All four responses declined as a function of age in control rats. Stress exposure significantly decreased concanavalin A and lipopolysaccharide proliferative responses in 12- and 18-month-old compared to control rats without altering IL-2 secretory capacity. NK cell activity was slightly depressed by stress only in 18-month-old rats. By contrast, in 25-month-old animals that already demonstrated immune response levels lower than those of younger animals, stress did not significantly affect the responses examined. Thus, younger rats were more susceptible to a decline in host-defense responses induced by long-term chronic stress than older rats. Overall, the data suggest that aging significantly and differentially modulates the ability of environmental stress to influence the immunocompetent status of the organism.

  14. Chronic Stress Reduces Nectin-1 mRNA Levels and Disrupts Dendritic Spine Plasticity in the Adult Mouse Perirhinal Cortex

    Directory of Open Access Journals (Sweden)

    Qian Gong

    2018-03-01

    Full Text Available In adulthood, chronic exposure to stressful experiences disrupts synaptic plasticity and cognitive function. Previous studies have shown that perirhinal cortex-dependent object recognition memory is impaired by chronic stress. However, the stress effects on molecular expression and structural plasticity in the perirhinal cortex remain unclear. In this study, we applied the chronic social defeat stress (CSDS paradigm and measured the mRNA levels of nectin-1, nectin-3 and neurexin-1, three synaptic cell adhesion molecules (CAMs implicated in the adverse stress effects, in the perirhinal cortex of wild-type (WT and conditional forebrain corticotropin-releasing hormone receptor 1 conditional knockout (CRHR1-CKO mice. Chronic stress reduced perirhinal nectin-1 mRNA levels in WT but not CRHR1-CKO mice. In conditional forebrain corticotropin-releasing hormone conditional overexpression (CRH-COE mice, perirhinal nectin-1 mRNA levels were also reduced, indicating that chronic stress modulates nectin-1 expression through the CRH-CRHR1 system. Moreover, chronic stress altered dendritic spine morphology in the main apical dendrites and reduced spine density in the oblique apical dendrites of perirhinal layer V pyramidal neurons. Our data suggest that chronic stress disrupts cell adhesion and dendritic spine plasticity in perirhinal neurons, which may contribute to stress-induced impairments of perirhinal cortex-dependent memory.

  15. Self-desiccation and its importance in concrete technology : Proceedings of the second international research seminar in Lund, June 18, 1999.

    OpenAIRE

    Persson, Bertil; Fagerlund, Göran

    1999-01-01

    Papers: - Early age chemical shrinkage and autogenous deformation of cement pastes. - Shrinkage of high-strength concrete at different ambient humidities. - A computer program to calculate drying of and desiccation in concrete. - Aspects of monitoring moisture changes using electrical impedance spectroscopy. - A Nordtest method for verification of self-desiccation in concrete. - Early age autogenous restrained shrinkage: Stress build up and relaxation. - Chemical shrinkage of cementitious pas...

  16. Chronic Stress Impairs Collateral Blood Flow Recovery in Aged Mice

    Science.gov (United States)

    2014-10-15

    sleeping , are associated with vas- cular dysfunction [21]; however, depression, as a cause of vascular dysfunction, remains a matter of debate [22, 23...uninterrupted). Control animals for the CSD group were housed for 6 h in a small wire box in their own home cage in a similar food/ liquid- deprived ...Behavioral Test The behavioral actions of the CSD and control groups were measured before and after the stress protocol. Avoidance of stressor (fear response

  17. A Unique ISR Program Determines Cellular Responses to Chronic Stress

    Czech Academy of Sciences Publication Activity Database

    Guan, B.J.; van Hoef, V.; Jobava, R.; Elroy-Stein, O.; Valášek, Leoš Shivaya; Cargnello, M.; Gao, X.H.; Krokowski, D.; Merrick, W.C.; Kimball, S.R.; Komar, A.A.; Koromilas, A.E.; Wynshaw-Boris, A.; Topisirovic, I.; Larsson, O.; Hatzoglou, M.

    2017-01-01

    Roč. 68, č. 5 (2017), s. 885-900 ISSN 1097-2765 R&D Projects: GA ČR(CZ) GA17-06238S EU Projects: Wellcome Trust(GB) 090812/B/09/A Institutional support: RVO:61388971 Keywords : UNFOLDED PROTEIN RESPONSE * EUKARYOTIC TRANSLATION INITIATION * ENDOPLASMIC-RETICULUM STRESS Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 14.714, year: 2016

  18. Chronic work stress and exhaustion is associated with higher allostastic load in female school teachers.

    Science.gov (United States)

    Bellingrath, Silja; Weigl, Tobias; Kudielka, Brigitte M

    2009-01-01

    Epidemiological studies have shown that chronic work stress or unfavourable psychosocial work conditions are prospectively associated with different adverse health outcomes. The aim of the present cross-sectional study was to investigate the relationship between work-related chronic stress as well as exhaustion and a cumulative measure of physiological wear-and-tear called allostastic load (AL). AL could be a possible biological pathway for how chronic work stress and exhaustion lead to health impairments in the long run. As the teaching profession has been proposed to be a potentially high stressful occupation, chronic work stress (effort-reward-imbalance) and exhaustion were assessed in 104 female school teachers. AL was first analyzed according to McEwen's classical model comprised of ten parameters including cortisol, epinephrine and norepinephrine, dehydroepiandrosterone-sulphate (DHEA-S), waist/hip-ratio (WHR), glycosylated haemoglobin (HbA1c), high-density lipoprotein (HDL), total cholesterol/HDL-ratio, and systolic and diastolic blood pressure. Additionally it was extended to include tumor-necrosis-factor-alpha (TNF-alpha), C-reactive protein (CRP), fibrinogen, D-dimer, percent-body-fat, triglycerides, and glucose levels. A substantial proportion of our sample was highly exhausted whereas relatively few teachers showed high effort-reward-imbalance. AL scores were significantly higher in women high on effort-reward-imbalance or suffering from exhaustion. Although all teachers had been in a good health status, chronic work stress as well as exhaustion appears to be associated with changes in a multi-system summary indicator of physiological risk.

  19. Norepinephrine mediates the transcriptional effects of heterotypic chronic stress on colonic motor function

    Science.gov (United States)

    Choudhury, Barun K.; Shi, Xuan-Zheng; Sarna, Sushil K.

    2009-01-01

    Chronic stress precipitates or exacerbates the symptoms of functional bowel disorders, including motility dysfunction. The cellular mechanisms of these effects are not understood. We tested the hypothesis that heterotypic chronic stress (HeCS) elevates the release of norepinephrine from the adrenal medulla, which enhances transcription of the gene-regulating expression of Cav1.2 (L-type) channels in colonic circular smooth muscle cells, resulting in enhanced colonic motor function. The experiments were performed in rats using a 9-day heterotypic chronic stress (HeCS) protocol. We found that HeCS, but not acute stress, time dependently enhances the contractile response to ACh in colonic circular smooth muscle strips and in single dissociated smooth muscle cells, the plasma levels of norepinephrine and the mRNA and protein expressions of the α1C subunit of Cav1.2 channels. These effects result in faster colonic transit and increase in defecation rate. The effects of HeCS are blocked by adrenalectomy but not by depletion of norepinephrine in sympathetic neurons. The inhibition of receptors for glucocortocoids, corticotropin-releasing hormone or nicotine also does not block the effects of heterotypic chronic stress. Norepinephrine acts on α- and β3-adrenergic receptors to induce the transcription of α1C subunit. We conclude that HeCS alters colonic motor function by elevating the plasma levels of norepinephrine. Colonic motor dysfunction is associated with enhanced gene transcription of Cav1.2 channels in circular smooth muscle cells. These findings suggest the potential cellular mechanisms by which heterotypic chronic stress may exacerbate motility dysfunction in patients with irritable bowel syndrome. PMID:19359422

  20. Effect of chronic restraint stress on inhibitory gating in the auditory cortex of rats.

    Science.gov (United States)

    Ma, Lanlan; Li, Wai; Li, Sibin; Wang, Xuejiao; Qin, Ling

    2017-05-01

    A fundamental adaptive mechanism of auditory function is inhibitory gating (IG), which refers to the attenuation of neural responses to repeated sound stimuli. IG is drastically impaired in individuals with emotional and cognitive impairments (i.e. posttraumatic stress disorder). The objective of this study was to test whether chronic stress impairs the IG of the auditory cortex (AC). We used the standard two-tone stimulus paradigm and examined the parametric qualities of IG in the AC of rats by recording the electrophysiological signals of a single-unit and local field potential (LFP) simultaneously. The main results of this study were that most of the AC neurons showed a weaker response to the second tone than to the first tone, reflecting an IG of the repeated input. A fast negative wave of LFP showed consistent IG across the sampled AC sites, whereas a slow positive wave of LFP had less IG effect. IG was diminished following chronic restraint stress at both, the single-unit and LFP level, due to the increase in response to the second tone. This study provided new evidence that chronic stress disrupts the physiological function of the AC. Lay Summary The effects of chronic stress on IG were investigated by recording both, single-unit spike and LFP activities, in the AC of rats. In normal rats, most of the single-unit and N25 LFP activities in the AC showed an IG effect. IG was diminished following chronic restraint stress at both, the single-unit and LFP level.

  1. The number of granule cells in rat hippocampus is reduced after chronic mild stress and re-established after chronic escitalopram treatment

    DEFF Research Database (Denmark)

    Jayatissa, Magdalena N; Bisgaard, Christina; West, Mark J

    2008-01-01

    mild stress and chronic escitalopram treatment. Furthermore, we investigated which classes of immature granule cells are affected by stress and targeted by escitalopram. Rats were initially exposed to 2weeks of CMS and 4weeks of escitalopram treatment with concurrent exposure to stress. The behavioral...... changes, indicating a decrease in sensitivity to a reward, were assessed in terms of sucrose consumption. We found a significant 22.4% decrease in the total number of granule cells in the stressed rats. This decrease was reversed in the stressed escitalopram treated rats that responded to the treatment......, but not in the rats that did not respond to escitalopram treatment. These changes were not followed by alterations in the volume of the granule cell layer. We also showed a differential regulation of dentate neurons, in different stages of development, by chronic stress and chronic escitalopram treatment. Our study...

  2. RU486 Reverses Emotional Disorders by Influencing Astrocytes and Endoplasmic Reticulum Stress in Chronic Restraint Stress Challenged Rats

    Directory of Open Access Journals (Sweden)

    Liru Dong

    2017-06-01

    Full Text Available Aims: To investigate the effect of RU486 (mifepristone on emotional disorders in chronic restraint stress-induced rats and to explore the mechanisms of that phenomenon. Methods: For this purpose, 80 healthy male Sprague Dawley rats were randomly divided into four groups: the normal group (Con group, The Con group members received no treatment, eating and drinking freely, the chronic restraint stress group (CRS group, normal Sprague Dawley rats treated with chronic restraint stress, 6 h/day for 21days, the propylene glycol group (CRS+propylene glycol and the RU486 group (CRS+RU486. RU486 or propylene glycol was administered 30 mins before each CRS procedure. Twenty-four hours after CRS exposure, we investigated the effects of CRS on the anxiety-like behavior using an elevated plus-maze (EPM. To explore the mechanisms of RU486 on anxiety, we measured the expression of glial fibrillary acid protein (GFAP and β-subunit of S100 (S100β via immunohistochemistry and western blot analysis. Apoptosis was demonstrated by flow cytometry. In addition, endoplasmic reticulum (ER stress markers, glucose regulated protein 78 (GRP78, C/EBP homologous protein (CHOP and Cysteine aspartic acid specific protease-12 (Caspase-12, were detected by western blot analysis. Results: Compared to the control group, rats in the CRS and propylene glycol group showed decreased exploratory behavior on the open arms during EPM testing, and these reductions were accompanied by significantly reduced GFAP and S100β expression, increased apoptosis and GRP78, CHOP, and caspase-12 expression in the amygdala. However, RU486 increases the exploratory behavior and reverses the changes of GFAP, S100β, GRP78, CHOP, and caspase-12 and protects cells against apoptosis. Conclusions: Taken together, these data suggest that exposure to chronic restraint stress decreases the number of astrocytes and induces apoptosis and ER stress in the amygdala, which are possible causes for psychiatric

  3. Chronic water stress reduces tree growth and the carbon sink of deciduous hardwood forests.

    Science.gov (United States)

    Brzostek, Edward R; Dragoni, Danilo; Schmid, Hans Peter; Rahman, Abdullah F; Sims, Daniel; Wayson, Craig A; Johnson, Daniel J; Phillips, Richard P

    2014-08-01

    Predicted decreases in water availability across the temperate forest biome have the potential to offset gains in carbon (C) uptake from phenology trends, rising atmospheric CO2 , and nitrogen deposition. While it is well established that severe droughts reduce the C sink of forests by inducing tree mortality, the impacts of mild but chronic water stress on forest phenology and physiology are largely unknown. We quantified the C consequences of chronic water stress using a 13-year record of tree growth (n = 200 trees), soil moisture, and ecosystem C balance at the Morgan-Monroe State Forest (MMSF) in Indiana, and a regional 11-year record of tree growth (n > 300 000 trees) and water availability for the 20 most dominant deciduous broadleaf tree species across the eastern and midwestern USA. We show that despite ~26 more days of C assimilation by trees at the MMSF, increasing water stress decreased the number of days of wood production by ~42 days over the same period, reducing the annual accrual of C in woody biomass by 41%. Across the deciduous forest region, water stress induced similar declines in tree growth, particularly for water-demanding 'mesophytic' tree species. Given the current replacement of water-stress adapted 'xerophytic' tree species by mesophytic tree species, we estimate that chronic water stress has the potential to decrease the C sink of deciduous forests by up to 17% (0.04 Pg C yr(-1) ) in the coming decades. This reduction in the C sink due to mesophication and chronic water stress is equivalent to an additional 1-3 days of global C emissions from fossil fuel burning each year. Collectively, our results indicate that regional declines in water availability may offset the growth-enhancing effects of other global changes and reduce the extent to which forests ameliorate climate warming. © 2014 John Wiley & Sons Ltd.

  4. Japanese quail's genetic background modulates effects of chronic stress on emotional reactivity but not spatial learning.

    Directory of Open Access Journals (Sweden)

    Agathe Laurence

    Full Text Available Chronic stress is known to enhance mammals' emotional reactivity and alters several of their cognitive functions, especially spatial learning. Few studies have investigated such effects in birds. We investigated the impact of a two-week stress on Japanese quail's emotional reactivity and spatial learning. Quail is an avian model widely used in laboratory studies and for extrapolation of data to other poultry species. As sensitivity to chronic stress can be modulated by intrinsic factors, we tested juvenile female Japanese quail from three lines, two of them divergently selected on tonic immobility duration, an indicator of general fearfulness. The different emotional reactivity levels of quail belonging to these lines can be revealed by a large variety of tests. Half of the birds were submitted to repeated unpredictable aversive events for two weeks, whereas the other half were left undisturbed. After this procedure, two tests (open field and emergence tests evaluated the emotional reactivity of treated and control quails. They were then trained in a T-maze for seven days and their spatial learning was tested. The chronic stress protocol had an impact on resting, preening and foraging in the home cage. As predicted, the emotional reactivity of treated quails, especially those selected for long tonic immobility duration, was higher. Our spatial learning data showed that the treatment enhanced acquisition but not memorization. However, intrinsic fearfulness did not seem to interact with the treatment in this test. According to an inverted U-shaped relationship between stress and cognition, chronic stress can improve the adaptability of birds to a stressful environment. We discussed the mechanisms possibly implied in the increase of emotional reactivity and spatial abilities.

  5. Functional recovery from sciatic nerve crush lesion in the rat correlates with individual differences in responses to chronic intermittent stress

    NARCIS (Netherlands)

    Gispen, W.H.; Meeteren, N.L.U.; Brakkee, J.H.; Helders, P.J.M.; Wiegant, V.M.

    1997-01-01

    The aim of the present study was to monitor the influence of chronic stress on functional recovery from a sciatic nerve crush lesion in the rat. Male Wistar rats underwent standard unilateral sciatic nerve crush. Subsequently, chronic stress was induced during the recovery phase using a daily 30 min

  6. Chronic psychological stress seems associated with elements of the metabolic syndrome in patients with ischaemic heart disease

    DEFF Research Database (Denmark)

    Bergmann, Natasha; Ballegaard, Søren; Krogh, Jesper

    2017-01-01

    Background and objectives: Chronic psychological stress, the metabolic syndrome (MS) and ischaemic heart disease (IHD) seem closely connected. In this study, we evaluate the association between chronic stress and elements of MS in patients with stable IHD. Design: Cross-sectional cohort study...

  7. Childhood Poverty, Chronic Stress, and Young Adult Working Memory: The Protective Role of Self-Regulatory Capacity

    Science.gov (United States)

    Evans, Gary W.; Fuller-Rowell, Thomas E.

    2013-01-01

    Prior research shows that childhood poverty as well as chronic stress can damage children's executive functioning (EF) capacities, including working memory. However, it is also clear that not all children suffer the same degree of adverse consequences from risk exposure. We show that chronic stress early in life (ages 9-13) links childhood…

  8. The effect of Brazilian propolis on serum thyroid hormones in broilers reared under chronic heat stress

    Science.gov (United States)

    This experiment evaluated the effect of dietary supplement with green Brazilian propolis on serum thyroxin (T4) and tri-iodothyronine (T3) levels in broiler chickens exposed to chronic heat stress for 4 wks (from 15 to 42 d of age). Five hundred and four 15-d-old, male broiler chickens (Ross 708) w...

  9. Habitat disturbance results in chronic stress and impaired health status in forest-dwelling paleotropical bats.

    Science.gov (United States)

    Seltmann, Anne; Czirják, Gábor Á; Courtiol, Alexandre; Bernard, Henry; Struebig, Matthew J; Voigt, Christian C

    2017-01-01

    Anthropogenic habitat disturbance is a major threat to biodiversity worldwide. Yet, before population declines are detectable, individuals may suffer from chronic stress and impaired immunity in disturbed habitats, making them more susceptible to pathogens and adverse weather conditions. Here, we tested in a paleotropical forest with ongoing logging and fragmentation, whether habitat disturbance influences the body mass and immunity of bats. We measured and compared body mass, chronic stress (indicated by neutrophil to lymphocyte ratios) and the number of circulating immune cells between several bat species with different roost types living in recovering areas, actively logged forests, and fragmented forests in Sabah, Malaysia. In a cave-roosting species, chronic stress levels were higher in individuals from fragmented habitats compared with conspecifics from actively logged areas. Foliage-roosting species showed a reduced body mass and decrease in total white blood cell counts in actively logged areas and fragmented forests compared with conspecifics living in recovering habitats. Our study highlights that habitat disturbance may have species-specific effects on chronic stress and immunity in bats that are potentially related to the roost type. We identified foliage-roosting species as particularly sensitive to forest habitat deterioration. These species may face a heightened extinction risk in the near future if anthropogenic habitat alterations continue.

  10. Brain opioid receptor density relates to stereotypies in chronically stressed pigs

    NARCIS (Netherlands)

    Loijens, L.W.S.; Schouten, W.G.P.; Wiepkema, P.R.; Wiegant, V.M.

    1999-01-01

    Opioid receptor densities were measured in the hippocampus of chronically stressed (tethered) pigs to study the involvement of endogenous opioid systems in stereotypy performance. Three groups of animals were housed tethered for 2 (n = 12), 5.5 (n = 12) and 8-9 months (n = 8), respectively, and the

  11. Effect of chronic exposure to aspartame on oxidative stress in the

    Indian Academy of Sciences (India)

    This study was aimed at investigating the chronic effect of the artificial sweetener aspartame on oxidative stress in brain regions of Wistar strain albino rats. Many controversial reports are available on the use of aspartame as it releases methanol as one of its metabolite during metabolism. The present study proposed to ...

  12. Effect of chronic exposure to aspartame on oxidative stress in the ...

    Indian Academy of Sciences (India)

    2012-08-03

    Aug 3, 2012 ... chronic aspartame (75 mg/kg) administration could release methanol and induce oxidative stress in the rat brain. To mimic the ..... Effect of aspartame (75 mg/kg body weight) on LPO activity (mmol/mg tissue) in rat brain discrete regions. ..... Oberly LW and Oberly TD 1986 Free radicals, cancer and aging; in.

  13. Efficacy of intravenous ketamine for treatment of chronic posttraumatic stress disorder : A randomized clinical trial

    NARCIS (Netherlands)

    Feder, Adriana; Parides, Michael K.; Murrough, James W.; Perez, Andrew M.; Morgan, Julia E.; Saxena, Shireen; Kirkwood, Katherine; Aan Het Rot, Marije; Lapidus, Kyle A.B.; Wan, Le-Ben; Iosifescu, Dan; Charney, Dennis S.

    2014-01-01

    IMPORTANCE Few pharmacotherapies have demonstrated sufficient efficacy in the treatment of posttraumatic stress disorder (PTSD), a chronic and disabling condition. OBJECTIVE To test the efficacy and safety of a single intravenous subanesthetic dose of ketamine for the treatment of PTSD and

  14. Early Intervention for Families Exposed to Chronic Stress and Trauma: The Attachment Vitamins Program

    Science.gov (United States)

    Hulette, Annmarie C.; Dunham, Mackenzie; Davis, Mindy; Gortney, Jason; Lieberman, Alicia F.

    2016-01-01

    This article describes the Attachment Vitamins program, a trauma-informed parent group intervention for families with young children. Attachment Vitamins is a relational psychoeducational intervention based on the principles of Child-Parent Psychotherapy (CPP). Its goal is to repair the impact of chronic stress and trauma through strengthening the…

  15. Homeostatic maintenance in excitability of tree shrew hippocampal CA3 pyramidal neurons after chronic stress

    NARCIS (Netherlands)

    Kole, Maarten H. P.; Czéh, Boldizsár; Fuchs, Eberhard

    2004-01-01

    The experience of chronic stress induces a reversible regression of hippocampal CA3 apical neuron dendrites. Although such postsynaptic membrane reduction will obviously diminish the possibility of synaptic input, the consequences for the functional membrane properties of these cells are not well

  16. The power of exercise: buffering the effect of chronic stress on telomere length.

    Directory of Open Access Journals (Sweden)

    Eli Puterman

    2010-05-01

    Full Text Available Chronic psychological stress is associated with detrimental effects on physical health, and may operate in part through accelerated cell aging, as indexed by shorter telomeres at the ends of chromosomes. However, not all people under stress have distinctly short telomeres, and we examined whether exercise can serve a stress-buffering function. We predicted that chronic stress would be related to short telomere length (TL in sedentary individuals, whereas in those who exercise, stress would not have measurable effects on telomere shortening.63 healthy post-menopausal women underwent a fasting morning blood draw for whole blood TL analysis by a quantitative polymerase chain reaction method. Participants completed the Perceived Stress Scale (Cohen et al., 1983, and for three successive days reported daily minutes of vigorous activity. Participants were categorized into two groups-sedentary and active (those getting Centers for Disease Control-recommended daily amount of activity. The likelihood of having short versus long telomeres was calculated as a function of stress and exercise group, covarying age, BMI and education. Logistic regression analyses revealed a significant moderating effect of exercise. As predicted, among non-exercisers a one unit increase in the Perceived Stress Scale was related to a 15-fold increase in the odds of having short telomeres (p<.05, whereas in exercisers, perceived stress appears to be unrelated to TL (B = -.59, SE = .78, p = .45.Vigorous physical activity appears to protect those experiencing high stress by buffering its relationship with TL. We propose pathways through which physical activity acts to buffer stress effects.

  17. Uncontrollable chronic stress reduces growth disparities in farmed Atlantic salmon

    DEFF Research Database (Denmark)

    Vindas, Marco A; Madaro, Angelico; Fraser, Thomas W.K.

    2017-01-01

    the final sampling. Biometric data was collected at the end of each period. Sampling on the final day was conducted in order to analyze basal monoaminergic activity in the brain stem and hypothalamus, as well as gene expression of target genes in the telencephalon. We found that post-hoc sorting...... releasing factor binding protein expression were positively associated with brain stem serotonergic activity, which is consistent with fish showing a stress reactivity neurophysiological profile. In conclusion, we here submit evidence that sorting individuals by their basal serotonergic activity levels may...

  18. Higher chronic stress is associated with a decrease in temporal sensitivity but not in subjective duration in healthy young men

    Directory of Open Access Journals (Sweden)

    Zhuxi eYao

    2015-07-01

    Full Text Available Maintaining accurate and precise temporal perception under conditions of stress is important. Studies in animal models and clinic patients have suggested that time perception can change under chronic stress. Little is known, however, about the relationship between chronic stress and time perception in healthy individuals. Here, a sample of 62 healthy young men completed Cohen’s Perceived Stress Scale (PSS as a measure of chronic stress levels, while time perception was measured using a temporal bisection task. This task used short (400 ms and long (1600 ms visual signals as anchor durations. Participants were presented with a range of intermediate probe durations and were required to judge whether the durations were more similar to the short or the long anchor. Results showed that chronic stress was negatively related to temporal sensitivity indexed by the Weber ratio. However, there was no significant correlation between chronic stress and subjective duration indexed by the bisection point. These results demonstrate that higher chronic stress is associated with lower temporal sensitivity and thus provide evidence for a link between chronic stress and time perception in healthy adults.

  19. Chronic stress during adolescence impairs and improves learning and memory in adulthood

    Directory of Open Access Journals (Sweden)

    Lauren Evelyn Chaby

    2015-12-01

    Full Text Available Exposure to acute stress can cause a myriad of cognitive impairments, but whether negative experiences continue to hinder individual as they age is not well understood. We determined how chronic unpredictable stress during adolescence affects multiple learning and memory processes in adulthood. Using male Sprague Dawley rats, we measured learning (both associative and reversal and memory (both reference and working starting 110 days after completion of the adolescent-stress treatment. We found that adolescent stress affected adult cognitive abilities in a context-dependent way. Compared to rats reared without stress, adolescent-stressed rats exhibited enhanced reversal learning, an indicator of behavioral flexibility, but showed no change in associative learning and reference memory abilities. Working memory, which in humans is thought to underpin reasoning, mathematical skills, and reading comprehension, may be enhanced by exposure to adolescent stress. However, when adolescent-stressed animals were tested after a novel disturbance, they exhibited a 5-fold decrease in working memory performance while unstressed rats continued to exhibit a linear learning curve. These results emphasize the capacity for stress during adolescence to transform the cognitive abilities of adult animals, even after stress exposure has ceased and animals have resided in safe environments for the majority of their lifespans.

  20. Nitrogen limitation and slow drying induce desiccation tolerance in conjugating green algae (Zygnematophyceae, Streptophyta from polar habitats.

    Directory of Open Access Journals (Sweden)

    Martina Pichrtová

    Full Text Available Filamentous Zygnematophyceae are typical components of algal mats in the polar hydro-terrestrial environment. Under field conditions, they form senescent vegetative cells, designated as pre-akinetes, which are tolerant to desiccation and osmotic stress.Pre-akinete formation and desiccation tolerance was investigated experimentally under monitored laboratory conditions in four strains of Arctic and Antarctic isolates with vegetative Zygnema sp. morphology. Phylogenetic analyses of rbcL sequences revealed one Arctic strain as genus Zygnemopsis, phylogenetically distant from the closely related Zygnema strains. Algae were cultivated in liquid or on solidified medium (9 weeks, supplemented with or lacking nitrogen. Nitrogen-free cultures (liquid as well as solidified consisted of well-developed pre-akinetes after this period. Desiccation experiments were performed at three different drying rates (rapid: 10% relative humidity, slow: 86% rh and very slow; viability, effective quantum yield of PS II, visual and ultrastructural changes were monitored. Recovery and viability of pre-akinetes were clearly dependent on the drying rate: slower desiccation led to higher levels of survival. Pre-akinetes survived rapid drying after acclimation by very slow desiccation.The formation of pre-akinetes in polar Zygnema spp. and Zygnemopsis sp. is induced by nitrogen limitation. Pre-akinetes, modified vegetative cells, rather than specialized stages of the life cycle, can be hardened by mild desiccation stress to survive rapid drying. Naturally hardened pre-akinetes play a key role in stress tolerance and dispersal under the extreme conditions of polar regions, where sexual reproduction and production of dormant stages is largely suppressed.

  1. Nitrogen limitation and slow drying induce desiccation tolerance in conjugating green algae (Zygnematophyceae, Streptophyta) from polar habitats.

    Science.gov (United States)

    Pichrtová, Martina; Kulichová, Jana; Holzinger, Andreas

    2014-01-01

    Filamentous Zygnematophyceae are typical components of algal mats in the polar hydro-terrestrial environment. Under field conditions, they form senescent vegetative cells, designated as pre-akinetes, which are tolerant to desiccation and osmotic stress. Pre-akinete formation and desiccation tolerance was investigated experimentally under monitored laboratory conditions in four strains of Arctic and Antarctic isolates with vegetative Zygnema sp. morphology. Phylogenetic analyses of rbcL sequences revealed one Arctic strain as genus Zygnemopsis, phylogenetically distant from the closely related Zygnema strains. Algae were cultivated in liquid or on solidified medium (9 weeks), supplemented with or lacking nitrogen. Nitrogen-free cultures (liquid as well as solidified) consisted of well-developed pre-akinetes after this period. Desiccation experiments were performed at three different drying rates (rapid: 10% relative humidity, slow: 86% rh and very slow); viability, effective quantum yield of PS II, visual and ultrastructural changes were monitored. Recovery and viability of pre-akinetes were clearly dependent on the drying rate: slower desiccation led to higher levels of survival. Pre-akinetes survived rapid drying after acclimation by very slow desiccation. The formation of pre-akinetes in polar Zygnema spp. and Zygnemopsis sp. is induced by nitrogen limitation. Pre-akinetes, modified vegetative cells, rather than specialized stages of the life cycle, can be hardened by mild desiccation stress to survive rapid drying. Naturally hardened pre-akinetes play a key role in stress tolerance and dispersal under the extreme conditions of polar regions, where sexual reproduction and production of dormant stages is largely suppressed.

  2. Chronic Stress During Adolescence Impairs and Improves Learning and Memory in Adulthood.

    Science.gov (United States)

    Chaby, Lauren E; Cavigelli, Sonia A; Hirrlinger, Amy M; Lim, James; Warg, Kendall M; Braithwaite, Victoria A

    2015-01-01

    HIGHLIGHTS This study tested the effects of adolescent-stress on adult learning and memory.Adolescent-stressed rats had enhanced reversal learning compared to unstressed rats.Adolescent-stress exposure made working memory more vulnerable to disturbance.Adolescent-stress did not affect adult associative learning or reference memory. Exposure to acute stress can cause a myriad of cognitive impairments, but whether negative experiences continue to hinder individual as they age is not as well understood. We determined how chronic unpredictable stress during adolescence affects multiple learning and memory processes in adulthood. Using male Sprague Dawley rats, we measured learning (both associative and reversal) and memory (both reference and working) starting 110 days after completion of an adolescent-stress treatment. We found that adolescent-stress affected adult cognitive abilities in a context-dependent way. Compared to rats reared without stress, adolescent-stressed rats exhibited enhanced reversal learning, an indicator of behavioral flexibility, but showed no change in associative learning and reference memory abilities. Working memory, which in humans is thought to underpin reasoning, mathematical skills, and reading comprehension, may be enhanced by exposure to adolescent-stress. However, when adolescent-stressed animals were tested after a novel disturbance, they exhibited a 5-fold decrease in working memory performance while unstressed rats continued to exhibit a linear learning curve. These results emphasize the capacity for stress during adolescence to transform the cognitive abilities of adult animals, even after stress exposure has ceased and animals have resided in safe environments for the majority of their lifespans.

  3. Vortioxetine restores reversal learning impaired by 5-HT depletion or chronic intermittent cold stress in rats.

    Science.gov (United States)

    Wallace, Ashley; Pehrson, Alan L; Sánchez, Connie; Morilak, David A

    2014-10-01

    Current treatments for depression, including serotonin-specific reuptake inhibitors (SSRIs), are only partially effective, with a high incidence of residual symptoms, relapse, and treatment resistance. Loss of cognitive flexibility, a component of depression, is associated with dysregulation of the prefrontal cortex. Reversal learning, a form of cognitive flexibility, is impaired by chronic stress, a risk factor for depression, and the stress-induced impairment in reversal learning is sensitive to chronic SSRI treatment, and is mimicked by serotonin (5-HT) depletion. Vortioxetine, a novel, multimodal-acting antidepressant, is a 5-HT3, 5-HT7 and 5-HT1D receptor antagonist, a 5-HT1B receptor partial agonist, a 5-HT1A receptor agonist, and inhibits the 5-HT transporter. Using adult male rats, we first investigated the direct effects of vortioxetine, acting at post-synaptic 5-HT receptors, on reversal learning that was compromised by 5-HT depletion using 4-chloro-DL-phenylalanine methyl ester hydrochloride (PCPA), effectively eliminating any contribution of 5-HT reuptake blockade. PCPA induced a reversal learning impairment that was alleviated by acute or sub-chronic vortioxetine administration, suggesting that post-synaptic 5-HT receptor activation contributes to the effects of vortioxetine. We then investigated the effects of chronic dietary administration of vortioxetine on reversal learning that had been compromised in intact animals exposed to chronic intermittent cold (CIC) stress, to assess vortioxetine's total pharmacological effect. CIC stress impaired reversal learning, and chronic vortioxetine administration prevented the reversal-learning deficit. Together, these results suggest that the direct effect of vortioxetine at 5-HT receptors may contribute to positive effects on cognitive flexibility deficits, and may enhance the effect of 5-HT reuptake blockade.

  4. Chronic Stress in Adolescents and Its Neurobiological and Psychopathological Consequences: An RDoC Perspective.

    Science.gov (United States)

    Sheth, Chandni; McGlade, Erin; Yurgelun-Todd, Deborah

    2017-01-01

    The Research Domain Criteria (RDoC) initiative provides a strategy for classifying psychopathology based on behavioral dimensions and neurobiological measures. Neurodevelopment is an orthogonal dimension in the current RDoC framework; however, it has not yet been fully incorporated into the RDoC approach. A combination of both a neurodevelopmental and RDoC approach offers a multidimensional perspective for understanding the emergence of psychopathology during development. Environmental influence (e.g., stress) has a profound impact on the risk for development of psychiatric illnesses. It has been shown that chronic stress interacts with the developing brain, producing significant changes in neural circuits that eventually increase the susceptibility for development of psychiatric disorders. This review highlights effects of chronic stress on the adolescent brain, as adolescence is a period characterized by a combination of significant brain alterations, high levels of stress, and emergence of psychopathology. The literature synthesized in this review suggests that chronic stress-induced changes in neurobiology and behavioral constructs underlie the shared vulnerability across a number of disorders in adolescence. The review particularly focuses on depression and substance use disorders; however, a similar argument can also be made for other psychopathologies, including anxiety disorders. The summarized findings underscore the need for a framework to integrate neurobiological findings from disparate psychiatric disorders and to target transdiagnostic mechanisms across disorders.

  5. Overlapping mechanisms of stress-induced relapse to opioid use disorder and chronic pain: Clinical implications

    Directory of Open Access Journals (Sweden)

    Udi E Ghitza

    2016-05-01

    Full Text Available Over the past two decades, a steeply growing number of persons with chronic non-cancer pain have been using opioid analgesics chronically to treat it, accompanied by a markedly increased prevalence of individuals with opioid-related misuse, opioid use disorders, emergency department visits, hospitalizations, admissions to drug treatment programs, and drug overdose deaths. This opioid misuse and overdose epidemic calls for well-designed randomized-controlled clinical trials into more skillful and appropriate pain management and for developing effective analgesics which have lower abuse liability and are protective against stress induced by chronic non-cancer pain. However, incomplete knowledge regarding effective approaches to treat various types of pain has been worsened by an under-appreciation of overlapping neurobiological mechanisms of stress, stress-induced relapse to opioid use, and chronic non-cancer pain in patients presenting for care for these conditions. This insufficient knowledge base has unfortunately encouraged common prescription of conveniently-available opioid pain-relieving drugs with abuse liability, as opposed to treating underlying problems using team-based multidisciplinary, patient-centered, collaborative-care approaches for addressing pain and co-occurring stress and risk for opioid use disorder. This paper reviews recent neurobiological findings regarding overlapping mechanisms of stress-induced relapse to opioid misuse and chronic non-cancer pain, and then discusses these in the context of key outstanding evidence gaps and clinical-treatment research directions which may be pursued to fill these gaps. Such research directions, if conducted through well-designed randomized controlled trials, may substantively inform clinical practice in general medical settings on how to effectively care for patients presenting with pain-related distress and these common co-occurring conditions.

  6. Exacerbation of N-nitrosodiethylamine Induced Hepatotoxicity and DNA Damage in Mice Exposed to Chronic Unpredictable Stress

    Directory of Open Access Journals (Sweden)

    Nayeem Bilal

    2017-06-01

    Full Text Available Psychological stress contributes to increased susceptibility to a number of diseases including cancer. The present study was designed to assess the effect of chronic unpredictable stress on N-nitrosodiethylamine induced liver toxicity in terms of in vivo antioxidant status and DNA damage in Swiss albino mice. The animals used in this study were randomized into different groups based on the treatment with N-nitrosodiethylamine or chronic unpredictable stress alone and post-stress administration of N-nitrosodiethylamine. The mice were sacrificed after 12 weeks of treatment, and the status of major enzymatic and non-enzymatic antioxidants, liver function markers, lipid peroxidation and the extent of DNA damage were determined in circulation and liver tissues of all the groups. The N-nitrosodiethylamine treated group showed significantly compromised levels of the antioxidant enzymes, lipid peroxidation, and the liver function markers with enhanced DNA damage as compared to chronic unpredictable stress or control groups. A similar but less typical pattern observed in the chronic unpredictable stress treated mice. All the measured biochemical parameters were significantly altered in the group treated with the combination of chronic unpredictable stress and N-nitrosodiethylamine when compared to controls, or chronic unpredictable stress alone and/or N-nitrosodiethylamine alone treated groups. Thus, exposure to continuous, unpredictable stress conditions even in general life may significantly enhance the hepatotoxic potential of N-nitrosodiethylamine through an increase in the oxidative stress and DNA damage.

  7. Electroconvulsive Stimulation, but not Chronic Restraint Stress, Causes Structural Alterations in Adult Rat Hippocampus

    DEFF Research Database (Denmark)

    Olesen, Mikkel V.; Wörtwein, Gitta; Pakkenberg, Bente

    2015-01-01

    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...

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

    DEFF Research Database (Denmark)

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

    2005-01-01

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

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

    DEFF Research Database (Denmark)

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

    2005-01-01

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

  10. Electroconvulsive stimulation reverses anhedonia and cognitive impairments in rats exposed to chronic mild stress

    DEFF Research Database (Denmark)

    Henningsen, K; Woldbye, D P D; Wiborg, O

    2013-01-01

    treatment on working memory and the chronic effect of repeated ECS treatments on depression-like behavior and working memory. The results indicated that, in the acute phase, ECS treatment induced a working memory deficit in healthy controls unexposed to stress, while repeated treatments reversed stress...... to reverse a depression-like state in the chronic mild stress model of depression (CMS), but the effect of ECS on cognition has not previously been investigated. In this study the CMS model was used to induce a depressive-like condition in rats. The study was designed to investigate the acute effect of ECS......-induced decline in working memory, as well as recovering rats submitted to the CMS paradigm from the anhedonic-like state. Like in the clinical setting, a single ECS exposure was ineffective in inducing remission from a depression-like state....

  11. Chronic workplace stress and insufficient physical activity: a cohort study.

    Science.gov (United States)

    Kouvonen, Anne; Vahtera, Jussi; Oksanen, Tuula; Pentti, Jaana; Väänänen, Ari K P; Heponiemi, Tarja; Salo, Paula; Virtanen, Marianna; Kivimäki, Mika

    2013-01-01

    To examine whether exposure to workplace stressors predicts changes in physical activity and the risk of insufficient physical activity. Prospective data from the Finnish Public Sector Study. Repeated exposure to low job control, high job demands, low effort, low rewards and compositions of these (job strain and effort-reward imbalance) were assessed at Time 1 (2000-2002) and Time 2 (2004). Insufficient physical activity (workplace stressors on change in physical activity was examined using fixed-effects (within-subject) logistic regression models (N=6665). In addition, logistic regression analysis was applied to examine the associations between repeated exposure to workplace stressors and insufficient physical activity (N=13 976). In these analyses, coworker assessed workplace stressor scores were used in addition to individual level scores. The proportion of participants with insufficient physical activity was 24% at baseline and 26% at follow-up. 19% of the participants who were sufficiently active at baseline became insufficiently active at follow-up. In the fixed-effect analysis, an increase in workplace stress was weakly related to an increase in physical inactivity within an individual. In between-subjects analysis, employees with repeated exposure to low job control and low rewards were more likely to be insufficiently active at follow-up than those with no reports of these stressors; fully adjusted ORs ranged from 1.11 (95% CI 1.00 to 1.24) to 1.21 (95% CI 1.05 to 1.39). Workplace stress is associated with a slightly increased risk of physical inactivity.

  12. Stress vulnerability during adolescence: comparison of chronic stressors in adolescent and adult rats.

    Science.gov (United States)

    Duarte, Josiane O; Cruz, Fábio C; Leão, Rodrigo M; Planeta, Cleopatra S; Crestani, Carlos C

    2015-01-01

    This study investigated the physiological and somatic changes evoked by daily exposure to the same type of stressor (homotypic) or different aversive stressor stimuli (heterotypic) in adolescent and adult rats, with a focus on cardiovascular function. The long-term effects of stress exposure during adolescence were also investigated longitudinally. Male Wistar rats were exposed to repeated restraint stress (RRS, homotypic) or chronic variable stress (CVS, heterotypic). Adrenal hypertrophy, thymus involution, and elevated plasma glucocorticoid were observed only in adolescent animals, whereas reduction in body weight was caused by both stress regimens in adults. CVS increased mean arterial pressure (adolescent: p = .001; adult: p = .005) and heart rate (HR; adolescent: p = .020; adult: p = .011) regardless of the age, whereas RRS increased blood pressure selectively in adults (p = .001). Rest tachycardia evoked by CVS was associated with increased cardiac sympathetic activity in adults, whereas a decreased cardiac parasympathetic activity was observed in adolescent animals. Changes in cardiovascular function and cardiac autonomic activity evoked by both CVS and RRS were followed by alterations in baroreflex activity and vascular reactivity to vasoconstrictor and vasodilator agents in adolescent adult animals. Except for the circulating glucocorticoid change, all alterations observed during adolescence were reversed in adulthood. These findings suggest a stress vulnerability of adolescents to somatic and neuroendocrine effects regardless of stress regimen. Our results indicated an age-stress type-specific influence in stress-evoked cardiovascular/autonomic changes. Data suggest minimal consequences in adulthood of stress during adolescence.

  13. [Protective effect of Shuyu Yiban decoction on atherosclerosis in rats induced by chronic unpredictable mild stress].

    Science.gov (United States)

    Zheng, Xiao-Jun; Hu, Zhi-Qiang; Luan, Shu-Wei; Li, Ran; Li, Yun; Li, Jian-Liang; Li, Yu-Jie; Zhu, Xiao-Xin

    2017-03-01

    Shuyu Yiban decoction(SYYB) has significant effect in treating the patients with coronary heart disease combined with chronic psychological stress. In this study, in order to observe the effects of SYYB on early formation of atherosclerosis(As) and inflammation response induced by chronic psychological stress, high-fat diet+intraperitoneal injections of Vitamin D3 were given to establish As early lesion models, and based on these models, chronic unpredictable mild stress(CUMS) was used to observe whether the chronic psychological stress could increase coronary atherosclerotic lesions investigate the intervention effect of SYYB(6.6, 13.2, 26.4 mg•kg⁻¹). The tail suspension test and novelty-feeding test were adopted to detectadrenocortico-tropic hormone(ACTH), cortisol(Cor) andnoradrenaline(NE) in serum and weigh thymus and adrenal gland, in order to assess the effects of SYYB on CUMS model rats. The pathological changes of vascular tissues in aortic arch were observed by using hematoxylin and eosin(HE) staining, and then the levels of triglycerides(TG), total cholesterol(TC) and high density lipoprotein(HDL-C) in serum were determined to assess effects of SYYB on As lesions. The effects of SYYB on the inflammatory response in As rats were assessed by detecting high-sensitivity C-reactive protein(hsCRP), interleukin-1β(IL-1β) and interleukin-6(IL-6) in serum. The results showed that as compared with the blank control group, TC and TG levels in As group were increased while HDL-C was markedly decreased; furthermore, the aortic wall was thickened in HE staining. Meanwhile, foam cells were formed, and the behavioral assessment and serum stress hormone test showed that there was a chronic stress response, indicating successful establishment of As+CUMS models in this study. The experiment demonstrated that SYYB could lower the levels of serum TC and TG, reduce foam cells, calcification and inflammatory cells infiltration. Moreover, SYYB could obviously lower levels

  14. Lack of correlation of desiccation and radiation tolerance in microorganisms from diverse extreme environments tested under anoxic conditions.

    Science.gov (United States)

    Beblo-Vranesevic, Kristina; Bohmeier, Maria; Perras, Alexandra K; Schwendner, Petra; Rabbow, Elke; Moissl-Eichinger, Christine; Cockell, Charles S; Vannier, Pauline; Marteinsson, Viggo T; Monaghan, Euan P; Ehrenfreund, Pascale; Garcia-Descalzo, Laura; Gómez, Felipe; Malki, Moustafa; Amils, Ricardo; Gaboyer, Frédéric; Westall, Frances; Cabezas, Patricia; Walter, Nicolas; Rettberg, Petra

    2018-03-01

    Four facultative anaerobic and two obligate anaerobic bacteria were isolated from extreme environments (deep subsurface halite mine, sulfidic anoxic spring, mineral-rich river) in the frame MASE (Mars Analogues for Space Exploration) project. The isolates were investigated under anoxic conditions for their survivability after desiccation up to 6 months and their tolerance to ionizing radiation up to 3000 Gy. The results indicated that tolerances to both stresses are strain-specific features. Yersinia intermedia MASE-LG-1 showed a high desiccation tolerance but its radiation tolerance was very low. The most radiation-tolerant strains were Buttiauxella sp. MASE-IM-9 and Halanaerobium sp. MASE-BB-1. In both cases, cultivable cells were detectable after an exposure to 3 kGy of ionizing radiation, but cells only survived desiccation for 90 and 30 days, respectively. Although a correlation between desiccation and ionizing radiation resistance has been hypothesized for some aerobic microorganisms, our data showed that there was no correlation between tolerance to desiccation and ionizing radiation, suggesting that the physiological basis of both forms of tolerances is not necessarily linked. In addition, these results indicated that facultative and obligate anaerobic organisms living in extreme environments possess varied species-specific tolerances to extremes.

  15. An assessment of desiccant cooling and dehumidification technology

    Energy Technology Data Exchange (ETDEWEB)

    Mei, V.C.; Chen, F.C. [Oak Ridge National Lab., TN (United States); Lavan, Z. [Illinois Inst. of Tech., Chicago, IL (United States); Collier, R.K. Jr. [Collier Engineering Services, Merritt Island, FL (United States); Meckler, G. [Gershon Meckler Associates, P.C., Herndon, VA (United States)

    1992-07-01

    Desiccant systems are heat-actuated cooling and dehumidification technology. With the recent advances in this technology, desiccant systems can now achieve a primary energy coefficient of performance (COP) between 1.3 and 1.5, with potential to go to 1.7 and higher. It is becoming one of the most promising alternatives to conventional cooling systems. Two important and well-known advantages of desiccant cooling systems are that they are CFC free and they can reduce the electricity peak load. Another important but lesser-known advantage of desiccant technology is its potential for energy conservation. The energy impact study in this report indicated that a possible 13% energy saving in residential cooling and 8% in commercial cooling is possible. Great energy saving potential also exists in the industrial sector if industrial waste heat can be used for desiccant regeneration. The latest study on desiccant-integrated building heating, ventilating, and air conditioning (HVAC) systems indicated that the initial cost for the conventional cooling equipment was greatly reduced by using desiccant technology because of downsized compressors, fans, and ductworks. This cost reduction was more than enough to offset the cost of desiccant equipment. Besides, the system operation cost was also reduced. All these indicate that desiccant systems are also cost effective. This study provides an updated state-of-the-art assessment forsiccant technology in the field of desiccant materials, systems, computer models, and theoretical analyses. From this information the technology options were derived and the future research and development needs were identified. Because desiccant technology has already been applied in the commercial building sector with very encouraging results, it is expected that future market breakthroughs will probably start in this sector. A market analysis for the commercial building application is therefore included.

  16. Effects of acute and chronic administration of methylprednisolone on oxidative stress in rat lungs

    Directory of Open Access Journals (Sweden)

    Ronaldo Lopes Torres

    2014-06-01

    Full Text Available Objective: To determine the effects of acute and chronic administration of methylprednisolone on oxidative stress, as quantified by measuring lipid peroxidation (LPO and total reactive antioxidant potential (TRAP, in rat lungs. Methods: Forty Wistar rats were divided into four groups: acute treatment, comprising rats receiving a single injection of methylprednisolone (50 mg/kg i.p.; acute control, comprising rats i.p. injected with saline; chronic treatment, comprising rats receiving methylprednisolone in drinking water (6 mg/kg per day for 30 days; and chronic control, comprising rats receiving normal drinking water. Results: The levels of TRAP were significantly higher in the acute treatment group rats than in the acute control rats, suggesting an improvement in the pulmonary defenses of the former. The levels of lung LPO were significantly higher in the chronic treatment group rats than in the chronic control rats, indicating oxidative damage in the lung tissue of the former. Conclusions: Our results suggest that the acute use of corticosteroids is beneficial to lung tissue, whereas their chronic use is not. The chronic use of methylprednisolone appears to increase lung LPO levels.

  17. Neuroinflammation and Behavior in HIV-1 Transgenic Rats Exposed to Chronic Adolescent Stress.

    Science.gov (United States)

    Rowson, Sydney A; Harrell, Constance S; Bekhbat, Mandakh; Gangavelli, Apoorva; Wu, Matthew J; Kelly, Sean D; Reddy, Renuka; Neigh, Gretchen N

    2016-01-01

    Highly active antiretroviral therapy (HAART) has improved prognosis for people living with HIV (PLWH) and dramatically reduced the incidence of AIDS. However, even when viral load is controlled, PLWH develop psychiatric and neurological disorders more frequently than those living without HIV. Adolescents with HIV are particularly susceptible to the development of psychiatric illnesses and neurocognitive impairments. While both psychiatric and neurocognitive disorders have been found to be exacerbated by stress, the extent to which chronic stress and HIV-1 viral proteins interact to impact behavior and relevant neuroinflammatory processes is unknown. Determination of the individual contributions of stress and HIV to neuropsychiatric disorders is heavily confounded in humans. In order to isolate the influence of HIV-1 proteins and chronic stress on behavior and neuroinflammation, we employed the HIV-1 transgenic (Tg) rat model, which expresses HIV-1 proteins with a gag and pol deletion, allowing for viral protein expression without viral replication. This Tg line has been characterized as a model of HAART-controlled HIV-1 infection due to the lack of viral replication but continued presence of HIV-1 proteins. We exposed male and female adolescent HIV-1 Tg rats to a mixed-modality chronic stress paradigm consisting of isolation, social defeat and restraint, and assessed behavior, cerebral vascularization, and neuroinflammatory endpoints. Stress, sex, and presence of the HIV-1 transgene impacted weight gain in adolescent rats. Female HIV-1 Tg rats showed decreases in central tendency during the light cycle in the open field regardless of stress exposure. Both male and female HIV-1 Tg rats exhibited decreased investigative behavior in the novel object recognition task, but no memory impairments. Adolescent stress had no effect on the tested behaviors. Microglia in female HIV-1 Tg rats exhibited a hyper-ramified structure, and gene expression of complement factor B was

  18. Individual differences in the effects of chronic stress on memory: behavioral and neurochemical correlates of resiliency.

    Science.gov (United States)

    Sweis, B M; Veverka, K K; Dhillon, E S; Urban, J H; Lucas, L R

    2013-08-29

    Chronic stress has been shown to impair memory, however, the extent to which memory can be impaired is often variable across individuals. Predisposed differences in particular traits, such as anxiety, may reveal underlying neurobiological mechanisms that could be driving individual differences in sensitivity to stress and, thus, stress resiliency. Such pre-morbid characteristics may serve as early indicators of susceptibility to stress. Neuropeptide Y (NPY) and enkephalin (ENK) are neurochemical messengers of interest implicated in modulating anxiety and motivation circuitry; however, little is known about how these neuropeptides interact with stress resiliency and memory. In this experiment, adult male rats were appetitively trained to locate sugar rewards in a motivation-based spatial memory task before undergoing repeated immobilization stress and then being tested for memory retention. Anxiety-related behaviors, among other characteristics, were monitored longitudinally. Results indicated that stressed animals which showed little to no impairments in memory post-stress (i.e., the more stress-resilient individuals) exhibited lower anxiety levels prior to stress when compared to stressed animals that showed large deficits in memory (i.e., the more stress-susceptible individuals). Interestingly, all stressed animals, regardless of memory change, showed reduced body weight gain as well as thymic involution, suggesting that the effects of stress on metabolism and the immune system were dissociated from the effects of stress on higher cognition, and that stress resiliency seems to be domain-specific rather than a global characteristic within an individual. Neurochemical analyses revealed that NPY in the hypothalamus and amygdala and ENK in the nucleus accumbens were modulated differentially between stress-resilient and stress-susceptible individuals, with elevated expression of these neuropeptides fostering anxiolytic and pro-motivation function, thus driving

  19. INFLUENCE OF ACUTE EXERCISE ON OXIDATIVE STRESS IN CHRONIC SMOKERS

    Directory of Open Access Journals (Sweden)

    Zehra Serdar

    2003-09-01

    Full Text Available The relative oxidative insult caused by exercise and smoking on biological systems are well documented, however, their cumulative influence needs to be clarified. In order to examine the collective effects of exercise and smoking on oxidant and antioxidant parameters, young male smokers (n=10 and non-smokers (n=10 made to perform a negative slope (10% cycling exercise for 30 minutes at individual load equivalent to 60% maximal oxygen consumption (VO2max. Pre- and post-exercise (post-ex haematocrit, haemoglobin, white blood cells, plasma malondialdehyde (MDA levels, protein carbonyl formation and non-HDL oxidation, erythrocyte superoxide dismutase (SOD and glutathione peroxidase (GPX activities, serum ceruloplasmin (CER and urinary cotinine concentrations were evaluated. Pre-ex CER and urinary cotinine concentrations of smokers were significantly higher (p<0.05 and p<0.01, respectively compared to that of non-smokers and pre-ex CER concentrations were significantly correlated with cotinine levels in all subjects (p<0.05. Significant (p<0.01 increases were observed in non-HDL oxidation following the exercise in both groups and the elevations were more pronounced in smokers. Pre-ex SOD and GPX activities were not different between the two groups, however post-ex enzyme activities were significantly reduced in smokers (p<0.05. MDA and protein carbonyl concentrations were not different between the two groups and there were not any significant changes due to exercise.In conclusion, according to the results of the present study, we suggest that erythrocyte antioxidants SOD and GPX and plasma non-HDL are more prone to the possible oxidant damage of acute physical exercise in chronic smokers.

  20. Inactivation of basolateral amygdala prevents chronic immobilization stress-induced memory impairment and associated changes in corticosterone levels.

    Science.gov (United States)

    Tripathi, Sunil Jamuna; Chakraborty, Suwarna; Srikumar, B N; Raju, T R; Shankaranarayana Rao, B S

    2017-07-01

    Chronic stress causes detrimental effects on various forms of learning and memory. The basolateral amygdala (BLA) not only plays a crucial role in mediating certain forms of memory, but also in the modulation of the effects of stress. Chronic immobilization stress (CIS) results in hypertrophy of the BLA, which is believed to be one of the underlying causes for stress' effects on learning. Thus, it is plausible that preventing the effects of CIS on amygdala would preclude its deleterious cognitive effects. Accordingly, in the first part, we evaluated the effect of excitotoxic lesion of the BLA on chronic stress-induced hippocampal-dependent spatial learning using a partially baited radial arm maze task. The BLA was ablated bilaterally using ibotenic acid prior to CIS. Chronically stressed rats showed impairment in spatial learning with decreased percentage correct choice and increased reference memory errors. Excitotoxic lesion of the BLA prevented the impairment in spatial learning and reference memory. In the retention test, lesion of the BLA was able to rescue the chronic stress-induced impairment. Interestingly, stress-induced enhanced plasma corticosterone levels were partially prevented by the lesion of BLA. These results motivated us to evaluate if the same effects can be observed with temporary inactivation of BLA, only during stress. We found that chronic stress-induced spatial learning deficits were also prevented by temporary inactivation of the BLA. Additionally, temporary inactivation of BLA partially precluded the stress-induced increase in plasma corticosterone levels. Thus, inactivation of BLA precludes stress-induced spatial learning deficits, and enhanced plasma corticosterone levels. It is speculated that BLA inactivation-induced reduction in corticosterone levels during stress, might be crucial in restoring spatial learning impairments. Our study provides evidence that amygdalar modulation during stress might be beneficial for strategic

  1. Impact of chronic and acute academic stress on lymphocyte subsets and monocyte function.

    Directory of Open Access Journals (Sweden)

    Viktoriya Maydych

    Full Text Available This study investigated the effects of a temporally confined naturalistic stressor (academic stress on immune functions. Furthermore, moderating influences of a number of psychological variables were assessed. Five blood samples were obtained from 20 students during an observation period of 8 weeks, starting 4.5 weeks before an exam period up to 1 week following the last exam. The analysis of 45 immune parameters revealed several time-dependent changes attributable to examination stress. We observed a reduction in the absolute numbers of natural killer (NK cells and monocytes in peripheral blood and a shift towards more immature and naïve cells within NK and T cell populations. In addition, IL-6 and TNF-α production by LPS-stimulated monocytes was increased. Psychological variables were grouped by means of factor analyses into two factors. One factor, which was interpreted as an indication of chronic stress, moderated the relationships between academic stress and percentages of mature CD57+ NK cells. This chronic stress factor was also associated with an increase in memory and a decrease in naïve CD8 T cells and increased serum levels of IL-17. The present study identifies important potential psychological mediators of stress-induced changes in specific immunological parameters.

  2. Impact of chronic and acute academic stress on lymphocyte subsets and monocyte function.

    Science.gov (United States)

    Maydych, Viktoriya; Claus, Maren; Dychus, Nicole; Ebel, Melanie; Damaschke, Jürgen; Diestel, Stefan; Wolf, Oliver T; Kleinsorge, Thomas; Watzl, Carsten

    2017-01-01

    This study investigated the effects of a temporally confined naturalistic stressor (academic stress) on immune functions. Furthermore, moderating influences of a number of psychological variables were assessed. Five blood samples were obtained from 20 students during an observation period of 8 weeks, starting 4.5 weeks before an exam period up to 1 week following the last exam. The analysis of 45 immune parameters revealed several time-dependent changes attributable to examination stress. We observed a reduction in the absolute numbers of natural killer (NK) cells and monocytes in peripheral blood and a shift towards more immature and naïve cells within NK and T cell populations. In addition, IL-6 and TNF-α production by LPS-stimulated monocytes was increased. Psychological variables were grouped by means of factor analyses into two factors. One factor, which was interpreted as an indication of chronic stress, moderated the relationships between academic stress and percentages of mature CD57+ NK cells. This chronic stress factor was also associated with an increase in memory and a decrease in naïve CD8 T cells and increased serum levels of IL-17. The present study identifies important potential psychological mediators of stress-induced changes in specific immunological parameters.

  3. Chronic stress is associated with reduced circulating hematopoietic progenitor cell number: A maternal caregiving model.

    Science.gov (United States)

    Aschbacher, Kirstin; Milush, Jeffrey M; Gilbert, Amanda; Almeida, Carlos; Sinclair, Elizabeth; Epling, Lorrie; Grenon, S Marlene; Marco, Elysa J; Puterman, Eli; Epel, Elissa

    2017-01-01

    Chronic psychological stress is a risk factor for cardiovascular disease and mortality. Circulating hematopoietic progenitor cells (CPCs) maintain vascular homeostasis, correlate with preclinical atherosclerosis, and prospectively predict cardiovascular events. We hypothesize that (1) chronic caregiving stress is related to reduced CPC number, and (2) this may be explained in part by negative interactions within the family. We investigated levels of stress and CPCs in 68 healthy mothers - 31 of these had children with an autism spectrum disorder (M-ASD) and 37 had neurotypical children (M-NT). Participants provided fasting blood samples, and CD45 + CD34 + KDR + and CD45 + CD133 + KDR + CPCs were assayed by flow cytometry. We averaged the blom-transformed scores of both CPCs to create one index. Participants completed the perceived stress scale (PSS), the inventory for depressive symptoms (IDS), and reported on daily interactions with their children and partners, averaged over 7 nights. M-ASD exhibited lower CPCs than M-NT (Cohen's d=0.83; p⩽0.01), controlling for age, BMI, and physical activity. Across the whole sample, positive interactions were related to higher CPCs, and negative interactions to lower CPCs (allp'scaregivers, child-related interpersonal stress appears to be a key psychological predictor of stress-related CVD risk. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. STRESS AS PREDISPOSING FACTOR OF SOME CHRONIC DISEASES INCLUDING PERIODONTAL DISEASE

    Directory of Open Access Journals (Sweden)

    Dewi-Nurul M Dewi-Nurul

    2006-04-01

    Full Text Available Stress is hypothesized as a common pathway for several related chronic diseases of man. Psychosocial stress as modified by perceptions and coping by patients can lead to physical processes. Psychoneuroimmunologic (PNI studies have suggested that psychosocial stress can alter immune function and increase vulnerability to illnesses. The patients also have high sensitivity to periodontal disease (PD. This article describes the association of stress as a physiological response to diseases such as PD, rheumatoid arthritis (RA, and inflammatory bowel disease. The psychosocial stress can lead to physiological processes through 1 the hypothalamic-pituitary-adrenal (HPA axis leading to glucocortico-steroid secretion; 2 the autonomic nervous system, resulting in the release of catecholamine; or 3 the hypothalamic-pituitary-gonadal axis, resulting in the release of sex hormones. These processes may affect chronic diseases. It can be concluded that psychosocial stress in periodontal disease patients must be considered and social support must be provided in order to achieve an optimum periodontal therapy result.

  5. Housing in Pyramid Counteracts Neuroendocrine and Oxidative Stress Caused by Chronic Restraint in Rats

    Directory of Open Access Journals (Sweden)

    M. Surekha Bhat

    2007-01-01

    Full Text Available The space within the great pyramid and its smaller replicas is believed to have an antistress effect. Research has shown that the energy field within the pyramid can protect the hippocampal neurons of mice from stress-induced atrophy and also reduce neuroendocrine stress, oxidative stress and increase antioxidant defence in rats. In this study, we have, for the first time, attempted to study the antistress effects of pyramid exposure on the status of cortisol level, oxidative damage and antioxidant status in rats during chronic restraint stress. Adult female Wistar rats were divided into four groups as follows: normal controls (NC housed in home cage and left in the laboratory; restrained rats (with three subgroups subject to chronic restraint stress by placing in a wire mesh restrainer for 6 h per day for 14 days, the restrained controls (RC having their restrainers kept in the laboratory; restrained pyramid rats (RP being kept in the pyramid; and restrained square box rats (RS in the square box during the period of restraint stress everyday. Erythrocyte malondialdehyde (MDA and plasma cortisol levels were significantly increased and erythrocyte-reduced glutathione (GSH levels, erythrocyte glutathione peroxidase (GSH-Px and superoxide dismutase (SOD activities were significantly decreased in RC and RS rats as compared to NC. However, these parameters were maintained to near normal levels in RP rats which showed significantly decreased erythrocyte MDA and plasma cortisol and significantly increased erythrocyte GSH levels, erythrocyte GSH-Px and SOD activities when compared with RS rats. The results showed that housing in pyramid counteracts neuroendocrine and oxidative stress caused by chronic restraint in rats.

  6. Nicotine Significantly Improves Chronic Stress-Induced Impairments of Cognition and Synaptic Plasticity in Mice.

    Science.gov (United States)

    Shang, Xueliang; Shang, Yingchun; Fu, Jingxuan; Zhang, Tao

    2017-08-01

    The aim of this study was to examine if nicotine was able to improve cognition deficits in a mouse model of chronic mild stress. Twenty-four male C57BL/6 mice were divided into three groups: control, stress, and stress with nicotine treatment. The animal model was established by combining chronic unpredictable mild stress (CUMS) and isolated feeding. Mice were exposed to CUMS continued for 28 days, while nicotine (0.2 mg/kg) was also administrated for 28 days. Weight and sucrose consumption were measured during model establishing period. The anxiety and behavioral despair were analyzed using the forced swim test (FST) and open-field test (OFT). Spatial cognition was evaluated using Morris water maze (MWM) test. Following behavioral assessment, both long-term potentiation (LTP) and depotentiation (DEP) were recorded in the hippocampal dentate gyrus (DG) region. Both synaptic and Notch1 proteins were measured by Western. Nicotine increased stressed mouse's sucrose consumption. The MWM test showed that spatial learning and reversal learning in stressed animals were remarkably affected relative to controls, whereas nicotine partially rescued cognitive functions. Additionally, nicotine considerably alleviated the level of anxiety and the degree of behavioral despair in stressed mice. It effectively mitigated the depression-induced impairment of hippocampal synaptic plasticity, in which both the LTP and DEP were significantly inhibited in stressed mice. Moreover, nicotine enhanced the expression of synaptic and Notch1 proteins in stressed animals. The results suggest that nicotine ameliorates the depression-like symptoms and improves the hippocampal synaptic plasticity closely associated with activating transmembrane ion channel receptors and Notch signaling components. Graphical Abstract ᅟ.

  7. A cafeteria diet modifies the response to chronic variable stress in rats.

    Science.gov (United States)

    Zeeni, N; Daher, C; Fromentin, G; Tome, D; Darcel, N; Chaumontet, C

    2013-03-01

    Stress is known to lead to metabolic and behavioral changes. To study the possible relationships between stress and dietary intake, male Sprague-Dawley rats were fed one of three diets for 6 weeks: high carbohydrate (HC), high fat (HF), or "Cafeteria" (CAF) (Standard HC plus a choice of highly palatable cafeteria foods: chocolate, biscuits, and peanut butter). After the first 3 weeks, half of the animals from each group (experimental groups) were stressed daily using a chronic variable stress (CVS) paradigm, while the other half of the animals (control groups) were kept undisturbed. Rats were sacrificed at the end of the 6-week period. The effects of stress and dietary intake on animal adiposity, serum lipids, and corticosterone were analyzed. Results showed that both chronic stress and CAF diet resulted in elevated total cholesterol, increased low-density lipoprotein (LDL), and lower high-density lipoprotein (HDL). In addition, increases in body weight, food intake, and intra-abdominal fat were observed in the CAF group compared with the other dietary groups. In addition, there was a significant interaction between stress and diet on serum corticosterone levels, which manifest as an increase in corticosterone levels in stressed rats relative to non-stressed controls in the HC and HF groups but not in the CAF group. These results show that a highly palatable diet, offering a choice of food items, is associated with a reduction in the response to CVS and could validate a stressor-induced preference for comfort food that in turn could increase body weight.

  8. Hierarchical Status Predicts Behavioral Vulnerability and Nucleus Accumbens Metabolic Profile Following Chronic Social Defeat Stress.

    Science.gov (United States)

    Larrieu, Thomas; Cherix, Antoine; Duque, Aranzazu; Rodrigues, João; Lei, Hongxia; Gruetter, Rolf; Sandi, Carmen

    2017-07-24

    Extensive data highlight the existence of major differences in individuals' susceptibility to stress [1-4]. While genetic factors [5, 6] and exposure to early life stress [7, 8] are key components for such neurobehavioral diversity, intriguing observations revealed individual differences in response to stress in inbred mice [9-12]. This raised the possibility that other factors might be critical in stress vulnerability. A key challenge in the field is to identify non-invasively risk factors for vulnerability to stress. Here, we investigated whether behavioral factors, emerging from preexisting dominance hierarchies, could predict vulnerability to chronic stress [9, 13-16]. We applied a chronic social defeat stress (CSDS) model of depression in C57BL/6J mice to investigate the predictive power of hierarchical status to pinpoint which individuals will exhibit susceptibility to CSDS. Given that the high social status of dominant mice would be the one particularly challenged by CSDS, we predicted and found that dominant individuals were the ones showing a strong susceptibility profile as indicated by strong social avoidance following CSDS, while subordinate mice were not affected. Data from 1 H-NMR spectroscopy revealed that the metabolic profile in the nucleus accumbens (NAc) relates to social status and vulnerability to stress. Under basal conditions, subordinates show lower levels of energy-related metabolites compared to dominants. In subordinates, but not dominants, levels of these metabolites were increased after exposure to CSDS. To the best of our knowledge, this is the first study that identifies non-invasively the origin of behavioral risk factors predictive of stress-induced depression-like behaviors associated with metabolic changes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Reduced synapse and axon numbers in the prefrontal cortex of rats subjected to a chronic stress model for depression

    DEFF Research Database (Denmark)

    Csabai, Dávid; Wiborg, Ove; Czéh, Boldizsár

    2018-01-01

    Stressful experiences can induce structural changes in neurons of the limbic system. These cellular changes contribute to the development of stress-induced psychopathologies like depressive disorders. In the prefrontal cortex of chronically stressed animals, reduced dendritic length and spine loss...... have been reported. This loss of dendritic material should consequently result in synapse loss as well, because of the reduced dendritic surface. But so far, no one studied synapse numbers in the prefrontal cortex of chronically stressed animals. Here, we examined synaptic contacts in rats subjected...... to an animal model for depression, where animals are exposed to a chronic stress protocol. Our hypothesis was that long term stress should reduce the number of axo-spinous synapses in the medial prefrontal cortex. Adult male rats were exposed to daily stress for 9 weeks and afterward we did a post mortem...

  10. Assessment of fructosamine concentrations in cats with acute and chronic stress

    Directory of Open Access Journals (Sweden)

    Lívia Fagundes Moraes

    2011-10-01

    Full Text Available Fructosamine are glycated serum proteins that are formed continuously due to the reaction between glucose and circulating proteins, and corresponding to the blood glucose control assessment over the last one to two weeks in cats. The fructosamine concentration has been used for differentiation between persistent and transient hyperglycemia. Therefore, the determination of fructosamine is considered the gold standard for monitoring glycemia into control in diabetic cats. The objective of this study was to evaluate the influence of acute and chronic stress of cats on serum fructosamine. 62 cats were selected from the Veterinary Hospital of FMVZ - UNESP, Botucatu campus. They were distributed into three groups: cats with a history of any illness or stress condition, excluding Diabetes Mellitus (DM, for a maximum of 48 hours (Group A, n = 21 or for a period exceeding 120 hours (Group B n = 27. The third group (Group C = control was formed by 14 health cats. The groups were evaluated for serum fructosamine, glucose, protein and albumin. In this study, there was a significant increase in the values of fructosamine in animals subjected to acute and chronic stress, but these values remained within the reference range. The animals were, on average, normoglycemic, despite the positive correlation between fructosamine and glucose concentrations. We conclude that the fructosamine concentration is influenced by acute and chronic stress in cats, remaining, however, within the reference range, and therefore, still useful in the diagnosis of DM.

  11. FILLING IN THE GAPS OF CHRONIC PSYCHOLOGICAL STRESS DISEASE MODELS: WHAT'S METABOLIC PROFILING HAVE TO DO WITH IT?

    Science.gov (United States)

    Chronic psychological stress has profound effects on human health and well being, and it is generally accepted that psychological stress is a burgeoning public health problem in modern day life. However, models used to describe or predict stress-related disease are generally plagued by the paucity o...

  12. Streptococcus pneumoniae Is Desiccation Tolerant and Infectious upon Rehydration

    Science.gov (United States)

    Walsh, Rebecca L.; Camilli, Andrew

    2011-01-01

    ABSTRACT Streptococcus pneumoniae (pneumococcus) is a frequent colonizer of the nasopharynx and one of the leading causative agents of otitis media, pneumonia, and meningitis. The current literature asserts that S. pneumoniae is transmitted person to person via respiratory droplets; however, environmental surfaces (fomites) have been linked to the spread of other respiratory pathogens. Desiccation tolerance has been to shown to be essential for long-term survival on dry surfaces. This study investigated the survival and infectivity of S. pneumoniae following desiccation under ambient conditions. We recovered viable bacteria after all desiccation periods tested, ranging from 1 h to 4 weeks. Experiments conducted under nutrient limitation indicate that desiccation is a condition separate from starvation. Desiccation of an acapsular mutant and 15 different clinical isolates shows that S. pneumoniae desiccation tolerance is independent of the polysaccharide capsule and is a species-wide phenomenon, respectively. Experiments demonstrating that nondesiccated and desiccated S. pneumoniae strains colonize the nasopharynx at comparable levels, combined with their ability to survive long-term desiccation, suggest that fomites may serve as alternate sources of pneumococcal infection. PMID:21610120

  13. Vacuum membrane distillation of liquid desiccants Utilizing Hollow Fiber Membranes

    KAUST Repository

    Lefers, Ryan

    2018-01-31

    This paper documents the testing of a vacuum membrane distillation system intended for use with liquid desiccants. Liquid desiccants offer the possibility for low-energy, ambient temperature dehumidification. Effective desalination and purification of diluted desiccants outputs two important products: a concentrated desiccant for reuse in dehumidification and fresh water. In this study, vacuum membrane distillation was used in the laboratory to purify diluted liquid desiccants. Calcium chloride and magnesium chloride were the desiccants selected for testing. Desiccant solutions were pumped through the lumens of poly(vinylidene fluoride) (PVDF) hollow fiber membranes at varying feed inlet temperatures, solution velocity rates and vacuum set points during membrane distillation. An average flux of 8 kg m-2 h-1 was obtained using 30 wt% magnesium chloride solution at a temperature of 50 °C while applying vacuum to achieve 25 mbar absolute pressure on the air side of the membrane. The results are promising for the development of a full-scale vacuum membrane distillation process for desiccant solution regeneration and fresh water recovery. In addition, the recovered condensate was of sufficient quality for use in agricultural irrigation or drinking water.

  14. Desiccation and storage of Lannea microcarpa from Burkina Faso

    NARCIS (Netherlands)

    Daws, M.I.; Gaméné, C.E.; Sacandé, M.; Pritchard, H.W.; Groot, S.P.C.; Hoekstra, F.

    2004-01-01

    Seeds of Lannea microcarpa collected from Brurkina Faso in 1997 and 1998 were subjected to desiccation and a range of storage conditions.Seeds were able to tolerate desiccation to low moisture contents (ca 5%) with little loss of viability. In addition, it was possible to store seeds at 25 degrees

  15. Analysis on a hybrid desiccant air-conditioning system

    International Nuclear Information System (INIS)

    Jia, C.X.; Dai, Y.J.; Wu, J.Y.; Wang, R.Z.

    2006-01-01

    Hybrid desiccant-assisted preconditioner and split cooling coil system, which combines the merits of moisture removal by desiccant and cooling coil for sensible heat removal, is a potential alternative to conventional vapor compression cooling systems. In this paper, experiments on a hybrid desiccant air-conditioning system, which is actually an integration of a rotary solid desiccant dehumidification and a vapor compression air-conditioning unit, had been carried out. It is found that, compared with the conventional VC (vapor compression) system, the hybrid desiccant cooling system economizes 37.5% electricity powers when the process air temperature and relative humidity are maintained at 30 o C, and 55% respectively. The reason why the hybrid desiccant cooling system features better performance relative to the VC system lies in the improvement brought about in the performance of the evaporator in VC unit due to desiccant dehumidification. A thermodynamic model of the hybrid desiccant system with R-22 as the refrigerant has been developed and the impact of operating parameters on the sensible heat ratio of the evaporator and the electric power saving rate has been analyzed. It is found that a majority of evaporators can operate in the dry condition even if the regeneration temperature is lower (i.e. 80 o C)

  16. Physical fitness level affects perception of chronic stress in military trainees.

    Science.gov (United States)

    Tuch, Carolin; Teubel, Thomas; La Marca, Roberto; Roos, Lilian; Annen, Hubert; Wyss, Thomas

    2017-12-01

    This study investigated whether physical fitness affects the perception of chronic stress in military trainees while controlling for established factors influencing stress perception. The sample consisted of 273 men (20.23 ± 1.12 years, 73.56 ± 10.52 kg, 1.78 ± 0.06 m). Physical fitness was measured by progressive endurance run (maximum oxygen uptake; VO 2 max), standing long jump, seated shot put, trunk muscle strength, and one leg standing test. Perceived stress was measured using the Perceived Stress Questionnaire in Weeks 1 and 11 of basic military training (BMT). VO 2 max and four influencing variables (perceived stress in Week 1, neuroticism, transformational leadership style, and education level) explained 44.44% of the variance of the increase in perceived stress during 10 weeks of BMT (R 2  = 0.444, F = 23.334, p stress. We conclude that it is advisable to provide conscripts with a specific endurance training program prior to BMT for stress prevention reasons. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Dormancy induction by summer temperatures and/or desiccation in imbibed seeds of trumpet daffodils Narcissus alcaracensis and N. longispathus (Amaryllidaceae).

    Science.gov (United States)

    Herranz, J M; Copete, E; Copete, M A; Márquez, J; Ferrandis, P

    2017-01-01

    We analysed the effects of summer temperatures (28/14 °C) and/or desiccation (from 48% to 8% humidity) on imbibed Narcissus alcaracensis and N. longispathus seeds with an elongating embryo. In the N. alcaracensis seeds that overcame dormancy (embryo elongation = 27.14%), exposure to high temperatures induced secondary dormancy and reduced subsequent embryo growth. A further 3-month cold stratification (5 °C) was required to break secondary dormancy. Desiccation in early embryo growth stages (elongation = 11.42%) also reduced germination. Desiccation in the seeds in a more advanced growth stage (i.e. embryo elongation = 27.14%) induced secondary dormancy, which the further 3-month cold stratification did not overcome. When desiccation was preceded by high temperatures, seeds better overcame secondary dormancy (i.e. longer embryo elongation and seed germination). Treatments did not affect seed viability. In the N. longispathus seeds that overcame dormancy (embryo elongation = 59.21%), exposure to high temperatures induced secondary dormancy and they needed a further 1-month stratification at 15/4 °C + 2 months at 5 °C to reactivate the germination process. When embryo elongation was 42.10%, seed desiccation totally impeded subsequent germination. When embryo elongation reached 59.21%, desiccation induced secondary dormancy, which was not overcome by the above-described stratification treatment. When desiccation was preceded by high temperatures, seeds better overcame dormancy. Stress treatments killed 5-10% of seeds. This study suggests that the seeds of species with complex morphophysiological dormancy (MPD) levels are sensitive to desiccation in early embryo development stages, as opposed to the seeds of species with deep simple epicotyl MPD, which better tolerate water stress. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  18. The effect of basolateral amygdala nucleus lesion on memory under acute,mid and chronic stress in male rats.

    Science.gov (United States)

    Ranjbar, Hoda; Radahmadi, Maryam; Alaei, Hojjatallah; Reisi, Parham; Karimi, Sara

    2016-12-20

    The basolateral amygdala (BLA) modulates memory for emotional events and is involved in both stress and memory. This study investigated different durations of stress and the role of BLA on serum corticosterone level and spatial and cognitive memory. Different durations of stress (acute, mid, and chronic stress), with and without BLA lesion were induced in rats by 6 h/day restraint stress for 1, 7, and 21 days. Memory functions were evaluated by novel object recognition (NOR) and object location test (OLT). The OLT findings showed locomotor activity and spatial memory slightly decreased with different durations of stress. The NOR findings significantly showed locomotor activity impairment in different durations of stress. Cognitive memory deficit was observed in mid stress. The corticosterone level significantly increased in the mid and chronic stress groups. Moreover, the mid stress was the strongest stress condition. There is a possibility that different stress durations act by different mechanisms. The recognition of a novel location decreased in all lesion groups. It was more severe in the NOR. The BLA lesion significantly decreased corticosterone level in the mid and chronic stress groups compared to similar groups without lesion. The BLA lesion caused more damage to cognitive than spatial memory in stressed groups.

  19. Timing matters: the interval between acute stressors within chronic mild stress modifies behavioral and physiologic stress responses in male rats.

    Science.gov (United States)

    Cavigelli, Sonia A; Bao, Alexander D; Bourne, Rebecca A; Caruso, Michael J; Caulfield, Jasmine I; Chen, Mary; Smyth, Joshua M

    2018-04-12

    Chronic mild stress can lead to negative health outcomes. Frequency, duration, and intensity of acute stressors can affect health-related processes. We tested whether the temporal pattern of daily acute stressors (clustered or dispersed across the day) affects depression-related physiology. We used a rodent model to keep stressor frequency, duration, and intensity constant, and experimentally manipulated the temporal pattern of acute stressors delivered during the active phase of the day. Adult male Sprague-Dawley rats were exposed to one of three chronic mild stress groups: Clustered: stressors that occurred within 1 hour of each other (n = 21), Dispersed: stressors that were spread out across the active phase (n = 21), and Control: no stressors presented (n = 21). Acute mild stressors included noise, strobe lights, novel cage, cage tilt, wet bedding, and water immersion. Depression-related outcomes included: sucrose preference, body weight, circulating glucocorticoid (corticosterone) concentration after a novel acute stressor and during basal morning and evening times, and endotoxin-induced circulating interleukin-6 concentrations. Compared to control rats, those in the Clustered group gained less weight, consumed less sucrose, had a blunted acute corticosterone response, and an accentuated acute interleukin-6 response. Rats in the Dispersed group had an attenuated corticosterone decline during the active period and after an acute stressor compared to the Control group. During a chronic mild stress experience, the temporal distribution of daily acute stressors affected health-related physiologic processes. Regular exposure to daily stressors in rapid succession may predict more depression-related symptoms, whereas exposure to stressors dispersed throughout the day may predict diminished glucocorticoid negative feedback.

  20. Efficient energy storage in liquid desiccant cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Hublitz, Astrid

    2008-07-18

    Liquid Desiccant Cooling Systems (LDCS) are open loop sorption systems for air conditioning that use a liquid desiccant such as a concentrated salt solution to dehumidify the outside air and cool it by evaporative cooling. Thermochemical energy storage in the concentrated liquid desiccant can bridge power mismatches between demand and supply. Low-flow LDCS provide high energy storage capacities but are not a state-of-the-art technology yet. The key challenge remains the uniform distribution of the liquid desiccant on the heat and mass transfer surfaces. The present research analyzes the factors of influence on the energy storage capacity by simulation of the heat and mass transfer processes and specifies performance goals for the distribution of the process media. Consequently, a distribution device for the liquid desiccant is developed that reliably meets the performance goals. (orig.)

  1. Environmental enrichment and cafeteria diet attenuate the response to chronic variable stress in rats.

    Science.gov (United States)

    Zeeni, N; Bassil, M; Fromentin, G; Chaumontet, C; Darcel, N; Tome, D; Daher, C F

    2015-02-01

    Exposure to an enriched environment (EE) or the intake of a highly palatable diet may reduce the response to chronic stress in rodents. To further explore the relationships between EE, dietary intake and stress, male Sprague-Dawley rats were fed one of two diets for 5 weeks: high carbohydrate (HC) or "cafeteria" (CAF) (Standard HC plus a choice of highly palatable cafeteria foods: chocolate, biscuits, and peanut butter). In addition, they were either housed in empty cages or cages with EE. After the first two weeks, half of the animals from each group were stressed daily using a chronic variable stress (CVS) paradigm, while the other half were kept undisturbed. Rats were sacrificed at the end of the 5-week period. The effects of stress, enrichment and dietary intake on animal adiposity, serum lipids, and stress hormones were analyzed. Results showed an increase in intra-abdominal fat associated with the CAF diet and an increase in body weight gain associated with both the CAF diet and EE. Furthermore, the increase in ACTH associated with CVS was attenuated in the presence of EE and the CAF diet independently while the stress-induced increase in corticosterone was reduced by the combination of EE and CAF feeding. The present study provides evidence that the availability of a positive environment combined to a highly palatable diet increases resilience to the effects of CVS in rats. These results highlight the important place of palatable food and supportive environments in reducing central stress responses. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Influence of omega-3 fatty acid status on the way rats adapt to chronic restraint stress.

    Directory of Open Access Journals (Sweden)

    Marie Hennebelle

    Full Text Available Omega-3 fatty acids are important for several neuronal and cognitive functions. Altered omega-3 fatty acid status has been implicated in reduced resistance to stress and mood disorders. We therefore evaluated the effects of repeated restraint stress (6 h/day for 21 days on adult rats fed omega-3 deficient, control or omega-3 enriched diets from conception. We measured body weight, plasma corticosterone and hippocampus glucocorticoid receptors and correlated these data with emotional and depression-like behaviour assessed by their open-field (OF activity, anxiety in the elevated-plus maze (EPM, the sucrose preference test and the startle response. We also determined their plasma and brain membrane lipid profiles by gas chromatography. Repeated restraint stress caused rats fed a control diet to lose weight. Their plasma corticosterone increased and they showed moderate behavioural changes, with increases only in grooming (OF test and entries into the open arms (EPM. Rats fed the omega-3 enriched diet had a lower stress-induced weight loss and plasma corticosterone peak, and reduced grooming. Rats chronically lacking omega-3 fatty acid exhibited an increased startle response, a stress-induced decrease in locomotor activity and exaggerated grooming. The brain omega-3 fatty acids increased as the dietary omega-3 fatty acids increased; diets containing preformed long-chain omega-3 fatty acid were better than diets containing the precursor alpha-linolenic acid. However, the restraint stress reduced the amounts of omega-3 incorporated. These data showed that the response to chronic restraint stress was modulated by the omega-3 fatty acid supply, a dietary deficiency was deleterious while enrichment protecting against stress.

  3. Prevalence and Determinants of Chronic Post-Traumatic Stress Disorder After Floods.

    Science.gov (United States)

    Chen, Long; Tan, Hongzhuan; Cofie, Reuben; Hu, Shimin; Li, Yan; Zhou, Jia; Yang, Tubao; Tang, Xuemin; Cui, Guanghui; Liu, Aizhong

    2015-10-01

    To explore the prevalence and determinants of chronic post-traumatic stress disorder (PTSD) among flood victims. A cross-sectional survey was carried out in 2014 among individuals who had experienced the 1998 floods and had been diagnosed with PTSD in 1999 in Hunan, China. Cluster sampling was used to select subjects from the areas that had been surveyed in 1999. PTSD was diagnosed according to DSM-IV criteria, social support was measured according to a Social Support Rating Scale, coping style was measured according to a Simplified Coping Style Questionnaire, and personality was measured by use of the revised Eysenck Personality Questionnaire Short Scale for Chinese. Data were collected through face-to-face interviews by use of a structured questionnaire. Multivariate logistic regression analysis was used to reveal the determinants of chronic PTSD. A total of 123 subjects were interviewed, 17 of whom (14.4%) were diagnosed with chronic PTSD. Chronic PTSD was significantly associated with disaster stressors (odds ratio [OR]: 1.74; 95% confidence interval [CI]: 1.22-2.47), nervousness (OR: 1.09; 95% CI: 1.01-1.17), and social support (OR: 0.85; 95 CI%: 0.74-0.98). Chronic PTSD in flood victims is significantly associated with disaster stressors, nervousness, and social support. These factors may play important roles in identifying persons at high risk of chronic PTSD.

  4. Chronic restraint stress inhibits hair growth via substance P mediated by reactive oxygen species in mice.

    Science.gov (United States)

    Liu, Nan; Wang, Lin-Hui; Guo, Ling-Ling; Wang, Guo-Qing; Zhou, Xi-Ping; Jiang, Yan; Shang, Jing; Murao, Koji; Chen, Jing-Wei; Fu, Wen-Qing; Zhang, Guo-Xing

    2013-01-01

    Solid evidence has demonstrated that psychoemotional stress induced alteration of hair cycle through neuropeptide substance P (SP) mediated immune response, the role of reactive oxygen species (ROS) in brain-skin-axis regulation system remains unknown. The present study aims to investigate possible mechanisms of ROS in regulation of SP-mast cell signal pathway in chronic restraint stress (CRS, a model of chronic psychoemotional stress) which induced abnormal of hair cycle. Our results have demonstrated that CRS actually altered hair cycle by inhibiting hair follicle growth in vivo, prolonging the telogen stage and delaying subsequent anagen and catagen stage. Up-regulation of SP protein expression in cutaneous peripheral nerve fibers and activation of mast cell were observed accompanied with increase of lipid peroxidation levels and reduction of the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in CRS mice skin. In addition, SP receptor antagonist (RP67580) reduced mast cell activations and lipid peroxidation levels as well as increased GSH-Px activity and normalized hair cycle. Furthermore, antioxidant Tempol (a free radical scavenger) also restored hair cycle, reduced SP protein expression and mast cell activation. Our study provides the first solid evidence for how ROS play a role in regulation of psychoemotional stress induced SP-Mast cell pathway which may provide a convincing rationale for antioxidant application in clinical treatment with psychological stress induced hair loss.

  5. Studies on protein turnover and energy expenditure in chronically undernourished adults during stress of infection

    International Nuclear Information System (INIS)

    Kurpad, A.V.; Shetty, P.S.; Reeds, P.J.

    1994-01-01

    Chronic undernutrition in man leads to adaptive responses which could reduce the requirements for dietary energy and protein. It is also possible that these adaptive responses, which are economical in nature, could lead to a decreased capacity for combating stress. Undernourished people are more susceptible to infections, and during these stresses, show different patterns of protein and energy metabolism from well-nourished subjects. Animal models have clearly shown a diminished response to tissue injury, in terms of the anabolic acute phase response. It is proposed to study the effect of prior nutritional status on the degree to which an infective stress stimulates the acute phase protein synthesis by the liver. In addition, the supply of amino acids to the liver in conditions of stress could come from the breakdown of body tissue proteins, particularly muscle. It is intended to study muscle protein turnover by the use of 13 C-leucine in undernourished subjects under conditions of stress. Since whole body protein turnover can be measured by two methods, using 15 N-glycine and 13 C-leucine, a comparison of these two methods will initially be made in chronically undernourished subjects. It is also intended to study daily energy expenditure in the subject by an isotopic method, i.e. the appearance of 13 CO 2 in the breath after the administration of 13 C-bicarbonate. (author). 8 refs

  6. DNA damage in a human population affected by chronic psychogenic stress.

    Science.gov (United States)

    Dimitroglou, Eva; Zafiropoulou, Maria; Messini-Nikolaki, Niki; Doudounakis, Stavros; Tsilimigaki, Smaragdi; Piperakis, Stylianos M

    2003-01-01

    The effects of chronic psychogenic stress on the expression of DNA damage and cellular response to the damage were investigated. Using the comet assay, basal DNA damage was found to be similar in lymphocytes of both affected and non-affected populations (n = 30 in both groups). The induction of DNA damage in lymphocytes by external factors (H2O2 and gamma-irradiation), was also investigated. In these studies, cells were treated with 50, 100 and 150 microM H2O2 for 5 minutes or with 0.8, 2.5 and 4.2 Gy gamma-rays. A significant difference was found between the chronically stressed and the control populations, indicating the enhanced sensitivity of the former population. Cells were also held for 2 hours after the treatment, allowing time for the cells to deal with the induced DNA damage. Based on the level of residual DNA strand breaks, cells from the stressed population had more breaks than the controls. Gender does not alter these findings. In conclusion, our data indicate that cells from the stressed population were more sensitive to the induction of DNA damage and had higher level of residual damage. Therefore, stress conditions may cause the affected individuals to be susceptible to environmental mutagenic agents.

  7. Chronic restraint stress inhibits hair growth via substance P mediated by reactive oxygen species in mice.

    Directory of Open Access Journals (Sweden)

    Nan Liu

    Full Text Available BACKGROUNDS: Solid evidence has demonstrated that psychoemotional stress induced alteration of hair cycle through neuropeptide substance P (SP mediated immune response, the role of reactive oxygen species (ROS in brain-skin-axis regulation system remains unknown. OBJECTIVES: The present study aims to investigate possible mechanisms of ROS in regulation of SP-mast cell signal pathway in chronic restraint stress (CRS, a model of chronic psychoemotional stress which induced abnormal of hair cycle. METHODS AND RESULTS: Our results have demonstrated that CRS actually altered hair cycle by inhibiting hair follicle growth in vivo, prolonging the telogen stage and delaying subsequent anagen and catagen stage. Up-regulation of SP protein expression in cutaneous peripheral nerve fibers and activation of mast cell were observed accompanied with increase of lipid peroxidation levels and reduction of the activities of superoxide dismutase (SOD and glutathione peroxidase (GSH-Px in CRS mice skin. In addition, SP receptor antagonist (RP67580 reduced mast cell activations and lipid peroxidation levels as well as increased GSH-Px activity and normalized hair cycle. Furthermore, antioxidant Tempol (a free radical scavenger also restored hair cycle, reduced SP protein expression and mast cell activation. CONCLUSIONS: Our study provides the first solid evidence for how ROS play a role in regulation of psychoemotional stress induced SP-Mast cell pathway which may provide a convincing rationale for antioxidant application in clinical treatment with psychological stress induced hair loss.

  8. The appraisal of chronic stress and the development of the metabolic syndrome: a systematic review of prospective cohort studies

    Science.gov (United States)

    Bergmann, N; Gyntelberg, F; Faber, J

    2014-01-01

    Chronic psychosocial stress has been proposed as a risk factor for the development of the metabolic syndrome (MES). This review gives a systematic overview of prospective cohort studies investigating chronic psychosocial stress as a risk factor for incident MES and the individual elements of MES. Thirty-nine studies were included. An association between chronic psychosocial stress and the development of MES was generally supported. Regarding the four elements of MES: i) weight gain: the prospective studies supported etiological roles for relationship stress, perceived stress, and distress, while the studies on work-related stress (WS) showed conflicting results; ii) dyslipidemi: too few studies on psychosocial stress as a risk factor for dyslipidemia were available to draw a conclusion; however, a trend toward a positive association was present; iii) type 2 diabetes mellitus (DM2): prospective studies supported perceived stress and distress as risk factors for the development of DM2 among men, but not among women, while WS was generally not supported as a risk factor among neither men nor women; iv) hypertension: marital stress and perceived stress might have an influence on blood pressure (BP), while no association was found regarding distress. Evaluating WS the results were equivocal and indicated that different types of WS affected the BP differently between men and women. In conclusion, a longitudinal association between chronic psychosocial stress and the development of MES seems present. However, the number of studies with sufficient quality is limited and the design of the studies is substantially heterogeneous. PMID:24743684

  9. Hippocampal activation of microglia may underlie the shared neurobiology of comorbid posttraumatic stress disorder and chronic pain.

    Science.gov (United States)

    Sun, Rao; Zhang, Zuoxia; Lei, Yishan; Liu, Yue; Lu, Cui'e; Rong, Hui; Sun, Yu'e; Zhang, Wei; Ma, Zhengliang; Gu, Xiaoping

    2016-01-01

    The high comorbidity rates of posttraumatic stress disorder and chronic pain have been widely reported, but the underlying mechanisms remain unclear. Emerging evidence suggested that an excess of inflammatory immune activities in the hippocampus involved in the progression of both posttraumatic stress disorder and chronic pain. Considering that microglia are substrates underlying the initiation and propagation of the neuroimmune response, we hypothesized that stress-induced activation of hippocampal microglia may contribute to the pathogenesis of posttraumatic stress disorder-pain comorbidity. We showed that rats exposed to single prolonged stress, an established posttraumatic stress disorder model, exhibited persistent mechanical allodynia and anxiety-like behavior, which were accompanied by increased activation of microglia and secretion of pro-inflammatory cytokines in the hippocampus. Correlation analyses showed that hippocampal activation of microglia was significantly correlated with mechanical allodynia and anxiety-like behavior. Our data also showed that both intraperitoneal and intra-hippocampal injection of minocycline suppressed single prolonged stress-induced microglia activation and inflammatory cytokines accumulation in the hippocampus, and attenuated both single prolonged stress-induced mechanical allodynia and anxiety-like behavior. Taken together, the present study suggests that stress-induced microglia activation in the hippocampus may serve as a critical mechanistic link in the comorbid relationship between posttraumatic stress disorder and chronic pain. The novel concept introduces the possibility of cotreating chronic pain and posttraumatic stress disorder. © The Author(s) 2016.

  10. Modeling and experimental validation of the desiccant wheel in a hybrid desiccant air conditioning system

    International Nuclear Information System (INIS)

    Wrobel, Jan; Morgenstern, Paula; Schmitz, Gerhard

    2013-01-01

    Modeling can be strong asset to the operation of air conditioning plants taking into account e.g. the strong dependency of local climate conditions for the operation of HVAC systems. This paper presents a validated physical model and a simplified model based on the results of the physical model for a desiccant wheel, which is the central part of a hybrid air conditioning system. The two models offer different advantages: While the physical model is complex and can be adapted flexibly to different wheel dimensions, desiccant materials or climatic conditions; the simplified model requires no knowledge of underlying equations and modeling language utilized and can be used for a first assessment of the potential of a desiccant cooling system in a certain location or for the use within online control systems. The coexistence of both models ensures that information tailored to the users' needs are made available. The validity of the physical model, and therewith the simplified model, is ensured through comparison with measurement obtained from a hybrid air conditioning system situated in northern Europe. The demonstration plant combines the advantages of a dedicated outdoor air system (DOAS) with the advantages of the common hybrid desiccant system to allow for energy efficient air conditioning in one installation. The availability of primary measurement data is extremely valuable to the process of model validation because knowledge about uncertainties and bias in measurement data unlikely to be known for secondary data can be used to understand and validate model results. A comparison of simulation results from the physical model to measurement data from the demonstration plant shows good compliance for a typical day of wheel operation after adjusting relevant model parameters. -- Highlights: ► The desiccant wheel as core component of a highly efficient HVAC pilot installation based on renewable energies. ► Modeling and experimental validation of a desiccant wheel

  11. The chronic mild stress (CMS) model of depression: History, evaluation and usage.

    Science.gov (United States)

    Willner, Paul

    2017-02-01

    Now 30 years old, the chronic mild stress (CMS) model of depression has been used in >1300 published studies, with a year-on-year increase rising to >200 papers in 2015. Data from a survey of users show that while a variety of names are in use (chronic mild/unpredictable/varied stress), these describe essentially the same procedure. This paper provides an update on the validity and reliability of the CMS model, and reviews recent data on the neurobiological basis of CMS effects and the mechanisms of antidepressant action: the volume of this research may be unique in providing a comprehensive account of antidepressant action within a single model. Also discussed is the use of CMS in drug discovery, with particular reference to hippocampal and extra-hippocampal targets. The high translational potential of the CMS model means that the neurobiological mechanisms described may be of particular relevance to human depression and mechanisms of clinical antidepressant action.

  12. Total Flavonoids Extracted from Xiaobuxin-Tang on the Hyperactivity of Hypothalamic-Pituitary-Adrenal Axis in Chronically Stressed Rats

    Directory of Open Access Journals (Sweden)

    Lei An

    2011-01-01

    Full Text Available Our previous studies have demonstrated that the total flavonoids (XBXT-2 isolated from the extract of Xiaobuxin-Tang (XBXT, a traditional Chinese herbal decoction, ameliorated behavioral alterations and hippocampal dysfunctions in chronically stressed rats. Studies over the last decades have suggested that the hyperactivity of hypothalamic-pituitary-adrenal (HPA axis is one of the most consistent findings in stress-related depression. Herein, we used the same chronic mild stress model of rats as before to further investigate the effect of XBXT-2 on the hyperactivity of HPA axis, including the stress hormones levels and glucocorticoid receptors (GRs expression. Our ELISA results showed that chronic administration of XBXT-2 (25, 50 mg kg−1, p.o., 28 days, the effective doses for behavioral responses significantly decreased serum corticosterone level and its upstream stress hormone adrenocorticotropic hormone (ACTH level in chronically stressed rats. Furthermore, western blotting result demonstrated XBXT-2 treatment ameliorated stress-induced decrease of GRs expression in hippocampus, an important target involved in the hyperactivity of HPA axis. These results were similar to that of classic antidepressant imipramine treatment (10 mg kg−1, p.o.. In conclusion, the modulation of HPA axis produced by XBXT-2, including the inhibition of stress hormones levels and up-regulation of hippocampal GRs expression, may be an important mechanism underlying its antidepressant-like effect in chronically stressed rats.

  13. Chronic juvenile stress produces corticolimbic dendritic architectural remodeling and modulates emotional behavior in male and female rats.

    Science.gov (United States)

    Eiland, Lisa; Ramroop, Johnny; Hill, Matthew N; Manley, Jasmine; McEwen, Bruce S

    2012-01-01

    Nearly 12% of US children are exposed to intense adverse experiences. Research has demonstrated that these experiences can negatively impact adult health, often resulting in psychopathology. Less attention, however, is given to the impact of childhood adverse experiences on childhood health and wellbeing. Using a rodent model of chronic juvenile stress (restraint 6 h daily from postnatal day 20 to 41), we report that chronic stress has significant immediate morbidities in both males and females during this developmental window. Specifically, we demonstrate that chronic juvenile stress produces depressive-like behavior and significant neuronal remodeling of brain regions likely involved in these behavioral alterations: the hippocampus, prefrontal cortex and amygdala. Chronically stressed males and females exhibit anhedonia, increased locomotion when exposed to novelty, and altered coping strategies when exposed to acute stress. Coincident with these behavioral changes, we report simplification of dendrites in the hippocampus and prefrontal cortex and concurrent hypertrophy of dendrites in the amygdala. Taken together, these results demonstrate that chronically stressed juveniles exhibit aberrant behavioral responses to acute challenges that occur in conjunction with stress-induced remodeling of brain regions intimately involved in regulating emotionality and stress reactivity. Further, the absence of sex differences in our reported stress responses, likely speaks to the decreased sensitivity of immature HPA regulating brain regions to sex hormones. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Chronic ethanol consumption induces mitochondrial protein acetylation and oxidative stress in the kidney

    OpenAIRE

    Harris, Peter S.; Roy, Samantha R.; Coughlan, Christina; Orlicky, David J.; Liang, Yongliang; Shearn, Colin T.; Roede, James R.; Fritz, Kristofer S.

    2015-01-01

    In this study, we present the novel findings that chronic ethanol consumption induces mitochondrial protein hyperacetylation in the kidney and correlates with significantly increased renal oxidative stress. A major proteomic footprint of alcoholic liver disease (ALD) is an increase in hepatic mitochondrial protein acetylation. Protein hyperacetylation has been shown to alter enzymatic function of numerous proteins and plays a role in regulating metabolic processes. Renal mitochondrial targets...

  15. Chronic low dose radiation exposure and oxidative stress in radiation workers

    International Nuclear Information System (INIS)

    Ali, S.S.; Bhatt, M.B.; Kulkarni, MM.; Rajan, R.; Singh, B.B.; Venkataraman, G.

    1996-01-01

    Free radicals have been implicated in the pathogenesis of several human diseases. In this study free radical stress due to low dose chronic radiation exposures of radiation workers was examined as a possible atherogenic risk factor. Data on lipid profiles, lipid peroxidation and reduced glutathione content in blood indicated an absence of correlation with radiation doses up to 125 mSv. (author). 13 refs., 1 fig

  16. Metabolic consequences and vulnerability to diet-induced obesity in male mice under chronic social stress.

    Directory of Open Access Journals (Sweden)

    Alessandro Bartolomucci

    Full Text Available Social and psychological factors interact with genetic predisposition and dietary habit in determining obesity. However, relatively few pre-clinical studies address the role of psychosocial factors in metabolic disorders. Previous studies from our laboratory demonstrated in male mice: 1 opposite status-dependent effect on body weight gain under chronic psychosocial stress; 2 a reduction in body weight in individually housed (Ind male mice. In the present study these observations were extended to provide a comprehensive characterization of the metabolic consequences of chronic psychosocial stress and individual housing in adult CD-1 male mice. Results confirmed that in mice fed standard diet, dominant (Dom and Ind had a negative energy balance while subordinate (Sub had a positive energy balance. Locomotor activity was depressed in Sub and enhanced in Dom. Hyperphagia emerged for Dom and Sub and hypophagia for Ind. Dom also showed a consistent decrease of visceral fat pads weight as well as increased norepinephrine concentration and smaller adipocytes diameter in the perigonadal fat pad. On the contrary, under high fat diet Sub and, surprisingly, Ind showed higher while Dom showed lower vulnerability to obesity associated with hyperphagia. In conclusion, we demonstrated that social status under chronic stress and individual housing deeply affect mice metabolic functions in different, sometime opposite, directions. Food intake, the hedonic response to palatable food as well as the locomotor activity and the sympathetic activation within the adipose fat pads all represent causal factors explaining the different metabolic alterations observed. Overall this study demonstrates that pre-clinical animal models offer a suitable tool for the investigation of the metabolic consequences of chronic stress exposure and associated psychopathologies.

  17. Metabolic Consequences and Vulnerability to Diet-Induced Obesity in Male Mice under Chronic Social Stress

    Science.gov (United States)

    Bartolomucci, Alessandro; Cabassi, Aderville; Govoni, Paolo; Ceresini, Graziano; Cero, Cheryl; Berra, Daniela; Dadomo, Harold; Franceschini, Paolo; Dell'Omo, Giacomo

    2009-01-01

    Social and psychological factors interact with genetic predisposition and dietary habit in determining obesity. However, relatively few pre-clinical studies address the role of psychosocial factors in metabolic disorders. Previous studies from our laboratory demonstrated in male mice: 1) opposite status-dependent effect on body weight gain under chronic psychosocial stress; 2) a reduction in body weight in individually housed (Ind) male mice. In the present study these observations were extended to provide a comprehensive characterization of the metabolic consequences of chronic psychosocial stress and individual housing in adult CD-1 male mice. Results confirmed that in mice fed standard diet, dominant (Dom) and Ind had a negative energy balance while subordinate (Sub) had a positive energy balance. Locomotor activity was depressed in Sub and enhanced in Dom. Hyperphagia emerged for Dom and Sub and hypophagia for Ind. Dom also showed a consistent decrease of visceral fat pads weight as well as increased norepinephrine concentration and smaller adipocytes diameter in the perigonadal fat pad. On the contrary, under high fat diet Sub and, surprisingly, Ind showed higher while Dom showed lower vulnerability to obesity associated with hyperphagia. In conclusion, we demonstrated that social status under chronic stress and individual housing deeply affect mice metabolic functions in different, sometime opposite, directions. Food intake, the hedonic response to palatable food as well as the locomotor activity and the sympathetic activation within the adipose fat pads all represent causal factors explaining the different metabolic alterations observed. Overall this study demonstrates that pre-clinical animal models offer a suitable tool for the investigation of the metabolic consequences of chronic stress exposure and associated psychopathologies. PMID:19180229

  18. Impact of chronic kidney disease and stress myocardial perfusion imaging as a predictor of cardiovascular events

    International Nuclear Information System (INIS)

    Furuhashi, Tatsuhiko; Joki, Nobuhiko; Hase, Hiroki; Masai, Hirofumi; Kunimasa, Taeko; Nakazato, Ryo; Fukuda, Hiroshi; Sugi, Kaoru; Moroi, Masao

    2011-01-01

    Stress myocardial perfusion imaging (MPI) is an established means of predicting cardiovascular events and is suitable in chronic kidney disease (CKD) patients. We aimed to evaluate the prognostic value of CKD parameters and an abnormal stress MPI for cardiovascular events. A total of 495 patients with suspected coronary artery disease (CAD) or history of CAD including 130 CKD patients not undergoing hemodialysis, underwent stress MPI (313 males, mean age 70 years) and were followed up for 14 months (mean period). CKD was defined as an estimated GFR of 2 and/or persistent proteinuria. Cardiovascular events were defined as sudden cardiac death, acute coronary syndrome and congestive heart failure requiring hospitalization. Cardiovascular events occurred in 41 (8.3%) patients. Multivariate Cox regression analysis indicated that CKD [hazard ratio (HR) =3.76, p<0.001] and a stress MPI summed difference score (SDS) of ≥2 (HR=3.78, p<0.001) were independent predictors of cardiovascular events; CKD plus abnormal stress MPI was also a strong predictor of cardiovascular events (non-CKD and SDS <2 vs. CKD and SDS ≥2, HR=15.9, p<0.001). Both CKD and myocardial ischemia detected by stress MPI are independent predictors for cardiovascular events. Coexistence of CKD and myocardial ischemia detected by stress MPI is more useful for short-term risk stratification of cardiovascular events. (author)

  19. Effects of chronic restraint stress on body weight, food intake, and hypothalamic gene expressions in mice.

    Science.gov (United States)

    Jeong, Joo Yeon; Lee, Dong Hoon; Kang, Sang Soo

    2013-12-01

    Stress affects body weight and food intake, but the underlying mechanisms are not well understood. We evaluated the changes in body weight and food intake of ICR male mice subjected to daily 2 hours restraint stress for 15 days. Hypothalamic gene expression profiling was analyzed by cDNA microarray. Daily body weight and food intake measurements revealed that both parameters decreased rapidly after initiating daily restraint stress. Body weights of stressed mice then remained significantly lower than the control body weights, even though food intake slowly recovered to 90% of the control intake at the end of the experiment. cDNA microarray analysis revealed that chronic restraint stress affects the expression of hypothalamic genes possibly related to body weight control. Since decreases of daily food intake and body weight were remarkable in days 1 to 4 of restraint, we examined the expression of food intake-related genes in the hypothalamus. During these periods, the expressions of ghrelin and pro-opiomelanocortin mRNA were significantly changed in mice undergoing restraint stress. Moreover, daily serum corticosterone levels gradually increased, while leptin levels significantly decreased. The present study demonstrates that restraint stress affects body weight and food intake by initially modifying canonical food intake-related genes and then later modifying other genes involved in energy metabolism. These genetic changes appear to be mediated, at least in part, by corticosterone.

  20. Possible antidepressant effects of vanillin against experimentally induced chronic mild stress in rats

    Directory of Open Access Journals (Sweden)

    Amira M. Abo-youssef

    2016-06-01

    Full Text Available Vanillin is a flavoring agent widely used in food and beverages such as chocolates and dairy products and it is also used to mask unpleasant tastes in medicine. It has been reported to have antioxidant, anti-inflammatory and antiapoptotic properties. The current study was designed to investigate the protective effects of vanillin against experimentally induced stress in rats. Briefly rats were subdivided into four groups. Three groups were subjected to chronic mild stress and the fourth group served as normal control group. One week before induction of stress drugs or saline was administered daily and continued for another nine weeks. At the end of the experimental period behavioral tests including sucrose preference test, forced swim test and elevated plus maze test were assessed. In addition, brain biochemical parameters including MDA, GSH, NO and serotonin were determined. Vanillin succeeded to restore the behavioral and biochemical changes associated with stress. It significantly increased sucrose consumption in sucrose preference test and time spent in open arm in elevated plus maze test as compared to stress control group. It also reduced immobility time in forced swim test and time spent in closed arm in elevated plus maze test. Additionally, it significantly decreased brain MDA and NO levels and significantly increased brain GSH and Serotonin levels compared to stress control group. It could be concluded that vanillin showed beneficial protective effects against experimentally induced stress in rats.

  1. Stress and psychopathology and its impact on quality of life in chronic anal fissure (CAF) patients.

    Science.gov (United States)

    Arısoy, Özden; Şengül, Neriman; Çakir, Affan

    2017-06-01

    Chronic anal fissure (CAF) onset, exacerbation, and impact on quality of life are influenced by a host of psychological, physiological, and social factors. We aimed to investigate the difference in psychopathology and stress between normal and CAF groups. Thirty CAF patients and 20 age-sex matched healthy controls were evaluated for Axis I psychopathology, depression, anxiety, and stress with Hamilton and Hospital Depression-Anxiety Scales, Perceived Stress Scale, and SF-36. With a mean age of 39.47, 83.3% of CAF patients were female. Anxiety-depression and stress scores were all significantly higher and functionality was lower in the CAF group compared to controls (p stress factor and 56.6% had an exacerbating stress factor; 56.7% of the patients had an ongoing Axis I psychopathology while 50% had a previous psychopathology. Pain (96.7% had pain (VAS = 6.55)) and bleeding (83.3% had bleeding (VAS = 4.14)) severity showed a negative impact on bodily pain and role limitations emotional subscales of SF36. There is a high comorbidity of psychopathology in the CAF patients and depression and anxiety severities show a negative impact on the quality of life. Stress acts as both a triggering and an exacerbating factor in CAF.

  2. Does Chronic Unpredictable Stress during Adolescence Affect Spatial Cognition in Adulthood?

    Science.gov (United States)

    Chaby, Lauren E; Sheriff, Michael J; Hirrlinger, Amy M; Lim, James; Fetherston, Thomas B; Braithwaite, Victoria A

    2015-01-01

    Spatial abilities allow animals to retain and cognitively manipulate information about their spatial environment and are dependent upon neural structures that mature during adolescence. Exposure to stress in adolescence is thought to disrupt neural maturation, possibly compromising cognitive processes later in life. We examined whether exposure to chronic unpredictable stress in adolescence affects spatial ability in late adulthood. We evaluated spatial learning, reference and working memory, as well as long-term retention of visuospatial cues using a radial arm water maze. We found that stress in adolescence decreased the rate of improvement in spatial learning in adulthood. However, we found no overall performance impairments in adult reference memory, working memory, or retention caused by adolescent-stress. Together, these findings suggest that adolescent-stress may alter the strategy used to solve spatial challenges, resulting in performance that is more consistent but is not refined by incorporating available spatial information. Interestingly, we also found that adolescent-stressed rats showed a shorter latency to begin the water maze task when re-exposed to the maze after an overnight delay compared with control rats. This suggests that adolescent exposure to reoccurring stressors may prepare animals for subsequent reoccurring challenges. Overall, our results show that stress in adolescence does not affect all cognitive processes, but may affect cognition in a context-dependent manner.

  3. Chronic stress and comfort foods: self-medication and abdominal obesity.

    Science.gov (United States)

    Dallman, Mary F; Pecoraro, Norman C; la Fleur, Susanne E

    2005-07-01

    Central corticotropin-releasing factor (CRF) networks are recruited by chronic stressors and elevated glucocorticoids (GCs) that initiate recruitment of central CRF activity in the amygdala. Increased central activity of the CRF network stimulates all monoaminergic cell groups, as well as premotor autonomic and other limbic structures resulting in the typical arousal, behavioral changes, autonomic, and neuroendocrine changes that accompany the chronic imposition of a stressor. By contrast, elevated GCs appear, through a variety of means to counteract the effects of central CRF, which they have initiated. Together with insulin, the GCs stimulate drive for and ingestion of "comfort foods" that may directly result in reduction of the negative effects of the chronic stressor in the nucleus Accumbens, through stimulation of the anterior, more pleasure-associated part of this cell group, thus reducing the weight of the stress-stimulated posterior, more defensive part. Furthermore, the shift in caloric intake from chow to preference for "comfort foods," together with elevated GCs and insulin, reorganize energy stores from a peripheral to a central distribution, primarily as abdominal fat. A signal associated with this fat depot appears, as with eating "comfort foods," to reduce the influence of the chronic stress network on behaviors, autonomic, and neuroendocrine outflow.

  4. Systemic Oxidative Stress Biomarkers in Chronic Periodontitis: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Zhiqiang Liu

    2014-01-01

    Full Text Available Oxidative stress biomarkers have been observed in peripheral blood of chronic periodontitis patients; however, their associations with periodontitis were not consistent. This meta-analysis was performed to clarify the associations between chronic periodontitis and oxidative biomarkers in systemic circulation. Electronic searches of PubMed and Embase databases were performed until October 2014 and articles were selected to meet inclusion criteria. Data of oxidative biomarkers levels in peripheral blood of periodontitis patients and periodontal healthy controls were extracted to calculate standardized mean differences (SMDs and 95% confidence intervals (CIs by using random-effects model. Of 31 eligible articles, 16 articles with available data were included in meta-analysis. Our results showed that periodontitis patients had significantly lower levels of total antioxidant capacity (SMD = −2.02; 95% CI: −3.08, −0.96; P=0.000 and higher levels of malondialdehyde (SMD = 0.99; 95% CI: 0.12, 1.86; P=0.026 and nitric oxide (SMD = 4.98; 95% CI: 2.33, 7.63; P=0.000 than periodontal healthy control. Superoxide dismutase levels between two groups were not significantly different (SMD = −1.72; 95% CI: −3.50, 0.07; P=0.059. In conclusion, our meta-analysis showed that chronic periodontitis is significantly associated with circulating levels of three oxidative stress biomarkers, indicating a role of chronic periodontitis in systemic diseases.

  5. Transcriptomics of desiccation tolerance in the streptophyte green alga Klebsormidium reveal a land plant-like defense reaction.

    Directory of Open Access Journals (Sweden)

    Andreas Holzinger

    Full Text Available Water loss has significant effects on physiological performance and survival rates of algae. However, despite the prominent presence of aeroterrestrial algae in terrestrial habitats, hardly anything is known about the molecular events that allow aeroterrestrial algae to survive harsh environmental conditions. We analyzed the transcriptome and physiology of a strain of the alpine aeroterrestrial alga Klebsormidium crenulatum under control and strong desiccation-stress conditions.For comparison we first established a reference transcriptome. The high-coverage reference transcriptome includes about 24,183 sequences (1.5 million reads, 636 million bases. The reference transcriptome encodes for all major pathways (energy, carbohydrates, lipids, amino acids, sugars, nearly all deduced pathways are complete or missing only a few transcripts. Upon strong desiccation, more than 7000 transcripts showed changes in their expression levels. Most of the highest up-regulated transcripts do not show similarity to known viridiplant proteins, suggesting the existence of some genus- or species-specific responses to desiccation. In addition, we observed the up-regulation of many transcripts involved in desiccation tolerance in plants (e.g. proteins similar to those that are abundant in late embryogenesis (LEA, or proteins involved in early response to desiccation ERD, and enzymes involved in the biosynthesis of the raffinose family of oligosaccharides (RFO known to act as osmolytes. Major physiological shifts are the up-regulation of transcripts for photosynthesis, energy production, and reactive oxygen species (ROS metabolism, which is supported by elevated cellular glutathione content as revealed by immunoelectron microscopy as well as an increase in total antiradical power. However, the effective quantum yield of Photosystem II and CO2 fixation decreased sharply under the applied desiccation stress. In contrast, transcripts for cell integrative functions such as

  6. Relief from detrimental consequences of chronic psychosocial stress in mice deficient for the metabotropic glutamate receptor subtype 7.

    Science.gov (United States)

    Peterlik, Daniel; Stangl, Christina; Bludau, Anna; Grabski, Dominik; Strasser, Robert; Schmidt, Dominic; Flor, Peter J; Uschold-Schmidt, Nicole

    2017-03-15

    Chronic stress-related psychiatric conditions and comorbid somatic pathologies are an enormous public health concern in modern society. The etiology of these disorders is complex, with stressors holding a chronic and psychosocial component representing the most acknowledged risk factor. During the last decades, research on the metabotropic glutamate receptor (mGlu) system advanced dramatically and much attention was given to the role of the metabotropic glutamate receptor subtype 7 (mGlu7) in acute stress-related behavior and physiology. However, virtually nothing is known about the potential involvement of mGlu7 in chronic psychosocial stress-related conditions. Using the chronic subordinate colony housing (CSC, 19 days) in male mice, we addressed whether central mGlu7 is altered upon chronic psychosocial stressor exposure and whether genetic ablation of mGlu7 interferes with the multitude of chronic stress-induced alterations. CSC exposure resulted in a downregulation of mGlu7 mRNA transcript levels in the prefrontal cortex, a brain region relevant for stress-related behaviors and physiology. Interestingly, mGlu7 deficiency relieved multiple chronic stress-induced alterations including the CSC-induced anxiety-prone phenotype; mGlu7 ablation also ameliorated CSC-induced physiological and immunological consequences such as hypothalamo-pituitary-adrenal (HPA) axis dysfunctions and colonic inflammation, respectively. Together, our findings provide first evidence for the involvement of mGlu7 in a wide range of behavioral and physiological alterations in response to chronic psychosocial stressor exposure. Moreover, the stress-protective phenotype of genetic mGlu7 ablation suggests mGlu7 pharmacological blockade to be a relevant option for the treatment of chronic stress-related emotional and somatic dysfunctions. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. The different roles of glucocorticoids in the hippocampus and hypothalamus in chronic stress-induced HPA axis hyperactivity.

    Directory of Open Access Journals (Sweden)

    Li-Juan Zhu

    Full Text Available Hypothalamus-pituitary-adrenal (HPA hyperactivity is observed in many patients suffering from depression and the mechanism underling the dysfunction of HPA axis is not well understood. Chronic stress has a causal relationship with the hyperactivity of HPA axis. Stress induces the over-synthesis of glucocorticoids, which will arrive at all the body containing the brain. It is still complicated whether glucocorticoids account for chronic stress-induced HPA axis hyperactivity and in which part of the brain the glucocorticoids account for chronic stress-induced HPA axis hyperactivity. Here, we demonstrated that glucocorticoids were indispensable and sufficient for chronic stress-induced hyperactivity of HPA axis. Although acute glucocorticoids elevation in the hippocampus and hypothalamus exerted a negative regulation of HPA axis, we found that chronic glucocorticoids elevation in the hippocampus but not in the hypothalamus accounted for chronic stress-induced hyperactivity of HPA axis. Chronic glucocorticoids exposure in the hypothalamus still exerted a negative regulation of HPA axis activity. More importantly, we found mineralocorticoid receptor (MR - neuronal nitric oxide synthesis enzyme (nNOS - nitric oxide (NO pathway mediated the different roles of glucocorticoids in the hippocampus and hypothalamus in regulating HPA axis activity. This study suggests that the glucocorticoids in the hippocampus play an important role in the development of HPA axis hyperactivity and the glucocorticoids in the hypothalamus can't induce hyperactivity of HPA axis, revealing new insights into understanding the mechanism of depression.

  8. The Different Roles of Glucocorticoids in the Hippocampus and Hypothalamus in Chronic Stress-Induced HPA Axis Hyperactivity

    Science.gov (United States)

    Liu, Xiao; Chen, Chen; Han, Zhou; Wu, Hai-Yin; Jing, Xing; Zhou, Hai-Hui; Suh, Hoonkyo; Zhu, Dong-Ya; Zhou, Qi-Gang

    2014-01-01

    Hypothalamus-pituitary-adrenal (HPA) hyperactivity is observed in many patients suffering from depression and the mechanism underling the dysfunction of HPA axis is not well understood. Chronic stress has a causal relationship with the hyperactivity of HPA axis. Stress induces the over-synthesis of glucocorticoids, which will arrive at all the body containing the brain. It is still complicated whether glucocorticoids account for chronic stress-induced HPA axis hyperactivity and in which part of the brain the glucocorticoids account for chronic stress-induced HPA axis hyperactivity. Here, we demonstrated that glucocorticoids were indispensable and sufficient for chronic stress-induced hyperactivity of HPA axis. Although acute glucocorticoids elevation in the hippocampus and hypothalamus exerted a negative regulation of HPA axis, we found that chronic glucocorticoids elevation in the hippocampus but not in the hypothalamus accounted for chronic stress-induced hyperactivity of HPA axis. Chronic glucocorticoids exposure in the hypothalamus still exerted a negative regulation of HPA axis activity. More importantly, we found mineralocorticoid receptor (MR) - neuronal nitric oxide synthesis enzyme (nNOS) - nitric oxide (NO) pathway mediated the different roles of glucocorticoids in the hippocampus and hypothalamus in regulating HPA axis activity. This study suggests that the glucocorticoids in the hippocampus play an important role in the development of HPA axis hyperactivity and the glucocorticoids in the hypothalamus can't induce hyperactivity of HPA axis, revealing new insights into understanding the mechanism of depression. PMID:24831808

  9. Chronic subordination stress phase advances adrenal and anterior pituitary clock gene rhythms.

    Science.gov (United States)

    Razzoli, Maria; Karsten, Carley; Yoder, J Marina; Bartolomucci, Alessandro; Engeland, William C

    2014-07-15

    Circadian rhythms in glucocorticoids are the product of interactions between the hypothalamic-pituitary-adrenal (HPA) axis and the mammalian clock gene system. The adrenal clock can generate the glucocorticoid rhythm that in turn synchronizes other peripheral clocks to maintain homeostasis. Stress acutely activates and chronically upregulates the HPA axis, suggesting that the adrenal clock could be modulated by stress. However, there is no direct evidence that stress affects the adrenal clock rhythm. We tested the hypothesis that a model of chronic subordination stress (CSS) that has a major impact on HPA axis regulation, metabolism, and emotional behavior alters adrenal and pituitary clock gene rhythms. Clock gene rhythms were assessed using mPER2::Luciferase (PER2Luc) knockin mice in which in vitro bioluminescence rhythms reflect the Per2 clock gene expression. PER2Luc mice that experienced CSS for 2 wk showed positive energy balance reflected by increased body weight and food intake. Additionally, CSS phase advanced the adrenal (∼2 h) and the pituitary (∼1 h) PER2Luc rhythm compared with control mice. The activity rhythm was not affected. The adrenal clock phase shift was associated with increased feed conversion efficiency, suggesting that the metabolic phenotype in CSS mice may be related to altered adrenal clock rhythmicity. Interestingly, a single subordination experience followed by 8 h sensory housing also phase advanced the adrenal, but not the pituitary, PER2Luc rhythm. Overall, these data demonstrate a stress-induced phase shift in a peripheral clock gene rhythm and differential stress sensitivity of two peripheral clocks within the HPA axis, suggesting a link between clock desynchrony and individual vulnerability to stress. Copyright © 2014 the American Physiological Society.

  10. Desiccant-Based Preconditioning Market Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, J.

    2001-01-11

    A number of important conclusions can be drawn as a result of this broad, first-phase market evaluation. The more important conclusions include the following: (1) A very significant market opportunity will exist for specialized outdoor air-handling units (SOAHUs) as more construction and renovation projects are designed to incorporate the recommendations made by the ASHRAE 62-1989 standard. Based on this investigation, the total potential market is currently $725,000,000 annually (see Table 6, Sect. 3). Based on the market evaluations completed, it is estimated that approximately $398,000,000 (55%) of this total market could be served by DBC systems if they were made cost-effective through mass production. Approximately $306,000,000 (42%) of the total can be served by a non-regenerated, desiccant-based total recovery approach, based on the information provided by this investigation. Approximately $92,000,000 (13%) can be served by a regenerated desiccant-based cooling approach (see Table 7, Sect. 3). (2) A projection of the market selling price of various desiccant-based SOAHU systems was prepared using prices provided by Trane for central-station, air-handling modules currently manufactured. The wheel-component pricing was added to these components by SEMCO. This resulted in projected pricing for these systems that is significantly less than that currently offered by custom suppliers (see Table 4, Sect. 2). Estimated payback periods for all SOAHU approaches were quite short when compared with conventional over-cooling and reheat systems. Actual paybacks may vary significantly depending on site-specific considerations. (3) In comparing cost vs benefit of each SOAHU approach, it is critical that the total system design be evaluated. For example, the cost premium of a DBC system is very significant when compared to a conventional air handling system, yet the reduced chiller, boiler, cooling tower, and other expense often equals or exceeds this premium, resulting in a

  11. Chronic intermittent hypoxia sensitizes acute hypothalamic-pituitary-adrenal stress reactivity and Fos induction in the rat locus coeruleus in response to subsequent immobilization stress.

    Science.gov (United States)

    Ma, S; Mifflin, S W; Cunningham, J T; Morilak, D A

    2008-07-17

    Obstructive sleep apnea (OSA) is associated with several pathophysiological conditions, including hypertension, obesity, insulin resistance, hypothalamic-pituitary-adrenal (HPA) dysregulation, and other endocrine and metabolic disturbances comprising the "metabolic syndrome." Repeated episodes of hypoxia in OSA may represent a chronic intermittent stress, leading to HPA dysregulation. Alterations in HPA reactivity could then contribute to or exacerbate other pathophysiological processes. We showed previously that another metabolic stressor, chronic intermittent cold stress, enhanced noradrenergic facilitation of acute HPA stress reactivity. In this study, we investigated whether chronic intermittent hypoxia (CIH), a rat model for the arterial hypoxemia that accompanies OSA, similarly sensitizes the HPA response to novel acute stress. Rats were exposed to CIH (alternating cycles of normoxia [3 min at 21% O(2)] and hypoxia [3 min at 10% O(2)], repeated continuously for 8 h/day during the light portion of the cycle for 7 days). On the day after the final CIH exposure, there were no differences in baseline plasma adrenocorticotropic hormone (ACTH), but the peak ACTH response to 30 min acute immobilization stress was greater in CIH-stressed rats than in controls. Induction of Fos expression by acute immobilization stress was comparable following CIH in several HPA-modulatory brain regions, including the paraventricular nucleus, bed nucleus of the stria terminalis, and amygdala. Fos induction was attenuated in lateral hypothalamus, an HPA-inhibitory region. By contrast, acute Fos induction was enhanced in noradrenergic neurons in the locus coeruleus following CIH exposure. Thus, similar to chronic cold stress, CIH sensitized acute HPA and noradrenergic stress reactivity. Plasticity in the acute stress response is important for long-term adaptation, but may also contribute to pathophysiological conditions associated with states of chronic or repeated stress, such as OSA

  12. Downregulation of dTps1 in Drosophila melanogaster larvae confirms involvement of trehalose in redox regulation following desiccation.

    Science.gov (United States)

    Thorat, Leena; Mani, Krishna-Priya; Thangaraj, Pradeep; Chatterjee, Suvro; Nath, Bimalendu B

    2016-03-01

    As a survival strategy to environmental water deficits, desiccation-tolerant organisms are commonly known for their ability to recruit stress-protective biomolecules such as trehalose. We have previously reported the pivotal role of trehalose in larval desiccation tolerance in Drosophila melanogaster. Trehalose has emerged as a versatile molecule, serving mainly as energy source in insects and also being a stress protectant. While several recent reports have revealed the unconventional role of trehalose in scavenging reactive oxygen species in yeast and plants, this aspect has not received much attention in animals. We examined the status of desiccation-induced generation of reactive oxygen species in D. melanogaster larvae and the possible involvement of trehalose in ameliorating the harmful consequences thereof. Insect trehalose synthesis is governed by the enzyme trehalose 6-phosphate synthase 1 (TPS1). Using the ubiquitous da-GAL4-driven expression of the dTps1-RNAi transgene, we generated dTps1-downregulated Drosophila larvae possessing depleted levels of dTps1 transcripts. This resulted in the inability of the larvae for trehalose synthesis, thereby allowing us to elucidate the significance of trehalose in the regulation of desiccation-responsive redox homeostasis. Furthermore, the results from molecular genetics studies, biochemical assays, electron spin resonance analyses and a simple, non-invasive method of whole larval live imaging suggested that trehalose in collaboration with superoxide dismutase (SOD) is involved in the maintenance of redox state in D. melanogaster.

  13. Chronic Stress in Young German Adults: Who Is Affected? A Prospective Cohort Study.

    Science.gov (United States)

    Herrera, Ronald; Berger, Ursula; Genuneit, Jon; Gerlich, Jessica; Nowak, Dennis; Schlotz, Wolff; Vogelberg, Christian; von Mutius, Erika; Weinmayr, Gudrun; Windstetter, Doris; Weigl, Matthias; Radon, Katja

    2017-10-31

    We aimed to prospectively assess changes in chronic stress among young adults transitioning from high school to university or working life. A population-based cohort in Munich and Dresden (Germany) was followed from age 16-18 (2002-2003) to age 20-23 (2007-2009) ( n = 1688). Using the Trier Inventory for the Assessment of Chronic Stress, two dimensions of stress at university or work were assessed: work overload and work discontent. In the multiple ordinal generalized estimating equations, socio-demographics, stress outside the workplace, and job history were additionally considered. At follow-up, 52% of the population were university students. Work overload increased statistically significantly from first to second follow-up, while work discontent remained constant at the population level. Students, compared to employees, reported a larger increase in work overload (adjusted odds ratio (OR): 1.33; 95% confidence interval (95% CI): 1.07, 1.67), while work discontent did not differ between the groups. In conclusion, work overload increases when young adults transition from school to university/job life, with university students experiencing the largest increase.

  14. Dealing with Stress: Defective Metabolic Adaptation in Chronic Obstructive Pulmonary Disease Pathogenesis.

    Science.gov (United States)

    Michaeloudes, Charalambos; Bhavsar, Pankaj K; Mumby, Sharon; Chung, Kian Fan; Adcock, Ian M

    2017-11-01

    The mitochondrion is the main site of energy production and a hub of key signaling pathways. It is also central in stress-adaptive response due to its dynamic morphology and ability to interact with other organelles. In response to stress, mitochondria fuse into networks to increase bioenergetic efficiency and protect against oxidative damage. Mitochondrial damage triggers segregation of damaged mitochondria from the mitochondrial network through fission and their proteolytic degradation by mitophagy. Post-translational modifications of the mitochondrial proteome and nuclear cross-talk lead to reprogramming of metabolic gene expression to maintain energy production and redox balance. Chronic obstructive pulmonary disease (COPD) is caused by chronic exposure to oxidative stress arising from inhaled irritants, such as cigarette smoke. Impaired mitochondrial structure and function, due to oxidative stress-induced damage, may play a key role in causing COPD. Deregulated metabolic adaptation may contribute to the development and persistence of mitochondrial dysfunction in COPD. We discuss the evidence for deregulated metabolic adaptation and highlight important areas for investigation that will allow the identification of molecular targets for protecting the COPD lung from the effects of dysfunctional mitochondria.

  15. Changes in proinflammatory cytokines and white matter in chronically stressed rats

    Directory of Open Access Journals (Sweden)

    Yang P

    2015-03-01

    Full Text Available Ping Yang,1 Zhenyong Gao,1 Handi Zhang,1 Zeman Fang,1 Cairu Wu,1 Haiyun Xu,1,2 Qing-Jun Huang1 1Mental Health Center, 2Department of Anatomy, Shantou University Medical College, Shantou, Guangdong, People’s Republic of China Abstract: Although the pathogenesis of depression, an incapacitating psychiatric ailment, remains largely unknown, previous human and animal studies have suggested that both proinflammatory cytokines and altered oligodendrocytes play important roles in the condition. This study examined these two factors in the brains of rats following unpredictable chronic mild stress for 4 weeks, with the hypothesis that chronic stress may affect oligodendrocytes and elevate proinflammatory cytokines in the brain. After suffering unpredictable stressors for 4 weeks, the rats showed depression-like behaviors, including decreased locomotion in the open field, increased immobility time in the forced swim test, and decreased sucrose consumption and less sucrose preference when compared with controls. Immunohistochemical staining of brain sections showed higher immunoreactivity of proinflammatory cytokines in certain brain regions of stressed rats compared with controls; lower immunoreactivity of myelin basic protein and fewer mature oligodendrocytes were seen in the prefrontal cortex, but no demyelination was detected. These results are interpreted and discussed in the context of recent findings from human and animal studies. Keywords: cytokines, depression, myelination, oligodendrocytes, stress 

  16. Solar assisted liquid desiccant cooling using clay based membranes

    Directory of Open Access Journals (Sweden)

    Priya S. Shanmuga

    2018-01-01

    Full Text Available The environmental concerns have led to the urge of the usage of non-conventional energy resources like solar, wind, thermal, geothermal etc. which provide enormous source of energy without causing any further diminution of the environment. Instead of the conventional HVAC systems that cause colossal environmental perils, usage of liquid desiccants in coming in vogue whereby reducing ecological threats. Moreover, solar assisted systems provide further impulse to such systems. This paper discusses about the various comparisons between liquid desiccants: Lithium chloride, Potassium formate and Calcium chloride and concludes that potassium formate is the best desiccant to be used among the three. Potassium formate (HCOOK is used which is cheaper and less corrosive as compared to the other aqueous salts, and has a negative crystallization temperature. Potassium formate is a new liquid desiccant and thus, not much research is available currently. The weather conditions of Manipal provide an appropriate condition for the experimentations of solar aided liquid desiccant evaporative cooling systems due to its humid climate and intense solar radiation obtained. The small scale experimentation also encounters the problem of liquid desiccant carryover by the air flow, with the help of clay based membranes which are again cheap, environmentally benign and obtained in a facile way. The projected system takes complete advantage of pure solar energy aimed at the regeneration of liquid desiccant.

  17. Polymers as advanced materials for desiccant applications, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Czanderna, A.W.; Neidlinger, H.H.

    1990-09-01

    This report documents work to identify a next-generation, low-cost material with which solar energy or heat from another low-cost energy source can be used for regenerating the water vapor sorption activity of the desiccant. The objective of the work is to determine how the desired sorption performance of advanced desiccant materials can be predicted by understanding the role of the material modifications and material surfaces. The work concentrates on solid materials to be used for desiccant cooling systems and which process water vapor in an atmosphere to produce cooling. The work involved preparing modifications of polystyrene sulfonic acid sodium salt, synthesizing a hydrogel, and evaluating the sorption performances of these and similar commercially available polymeric materials; all materials were studied for their potential application in solid commercial desiccant cooling systems. Background information is also provided on desiccant cooling systems and the role of a desiccant material within such a system, and it includes the use of polymers as desiccant materials. 31 refs., 16 figs., 5 tabs.

  18. Chronic Stress and Adolescents' Mental Health : Modifying Effects of Basal Cortisol and Parental Psychiatric History. The TRAILS Study

    NARCIS (Netherlands)

    Zandstra, Anna Roos E.; Hartman, Catharina A.; Nederhof, Esther; van den Heuvel, Edwin R.; Dietrich, Andrea; Hoekstra, Pieter J.; Ormel, Johan

    Large individual differences in adolescent mental health following chronic psychosocial stress suggest moderating factors. We examined two established moderators, basal cortisol and parental psychiatric history, simultaneously. We hypothesized that individuals with high basal cortisol, assumed to

  19. Experimental occlusal disharmony - A promoting factor for anxiety in rats under chronic psychological stress.

    Science.gov (United States)

    Tang, Xuan; Li, Jian; Jiang, Ting; Han, Shu-Hui; Yao, Dong-Yuan

    2017-04-03

    Clinically, patients under chronic psychological stress (PS) appear to be more susceptible to occlusal disharmony (OD) compared with those without PS. OD was proved to introduce anxiety-like stress. Therefore, the purpose of the study was to investigate whether OD would affect psychological stress-induced anxiety and its underlying mechanisms. Chronic PS was induced by a communication box, and OD was produced by bonding a 0.3mm-thick crown on the right maxillary first molar of male Sprague-Dawley rats. Sixty-seven rats were randomly divided into 8 groups: (A) chronic PS plus OD group (n=6); (B) chronic PS plus sham OD group (n=6); (C) chronic PS only group (n=6); (D) OD group (n=6); (E) sham OD group (n=6); (F) control group (n=6); (G) naive group (n=6); (H) foot-shock group (n=25). Open-field test (OFT) and elevated plus maze test (EPM) were conducted on the 7th, 21th, 35th day to measure the anxiety level of each group except naive and foot-shock group. In addition, corticosterone (CORT) level in serum, 5-hydroxytryptamine (5-HT) and 5-HT 2A receptor (5-HT 2A R) expressions in prefrontal cortex (PFC), hippocampal CA1 and dentate gyrus (DG) areas were measured on the 35th day to elucidate the mechanism(s) by which the exacerbation occurred. The significant differences in OFT and EPM tests on day 21 or day 35 between groups (p0.05), together with a gradual decrease in values of all the parameters mentioned above from group A to group G. The significant changes in exploratory behaviors, serum CORT concentration, 5-HT and 5-HT 2A R expressions induced by OD in rats with or without chronic PS, and more obvious alterations in rats with chronic PS, may indicate that OD may be a promoting factor for anxiety through both peripheral and central pathways via the hypothalamus-pituitary-adrenal (HPA) axis and 5-HT system. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Accelerated invagination of vacuoles as a stress response in chronically heat-stressed yeasts.

    Science.gov (United States)

    Ishii, Ayane; Kawai, Masahito; Noda, Haruka; Kato, Hiroyuki; Takeda, Kohei; Asakawa, Kotomi; Ichikawa, Yoshinobu; Sasanami, Tomohiro; Tanaka, Keiji; Kimura, Yoko

    2018-02-08

    When exposed to sublethal high temperatures, budding yeast cells can survive for a period of time; however, a sufficient amount of ubiquitin is necessary for this survival. To understand the nature of the stress, we examined the morphological changes in yeast cells, focusing on the vacuoles. Changes in vacuolar morphology were notable, and ruffled vacuolar membranes, accelerated invaginations of vacuolar membranes, and vesicle-like formations were observed. These changes occurred in the absence of Atg1, Atg9 or Ivy1 but appeared to require endosomal sorting proteins, such as Vps23, Vps24 or Pep12. Furthermore, the serial sections of the vacuoles analysed using an electron microscopic analysis revealed that spherical invaginated structures were linked together in a vacuole. Because degradation of cell surface proteins is induced from heat stress, fusion of endosomal and vacuolar membranes might occur frequently in heat-stressed cells, and yeast cells might be able to cope with a rapid increase in vacuolar surface area by such invaginations.

  1. Evaluation of chronic stress indicators in geriatric and oncologic caregivers: a cross-sectional study.

    Science.gov (United States)

    Aguiló, Sira; García, Esther; Arza, Adriana; Garzón-Rey, Jorge M; Aguiló, Jordi

    2018-01-01

    Caregiving induces chronic stress with physical and psychological impact on informal caregivers health. Therefore, subjective and objective indicators are needed for the early diagnosis of pathologic stress to prevent the risk of developing stress-related diseases in caregivers. Our aim was to assess the self-perceived stress, that is, how and how much the stressor affects the individual, through endocrine, metabolic, and immunologic biomarkers levels in geriatric and oncologic informal caregivers. Informal caregivers and non-caregivers were invited to participate in a cross-sectional study at the Clinic Hospital of Barcelona. Demographic and lifestyle characteristics, self-perceived stress (Perceived Stress Scale, State-Trait Anxiety Inventory and Stress Visual Analogue Scale), and biomarkers (copeptin, glucose, glycated hemoglobin, low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), cholesterol, triglycerides, α-amylase, cortisol, tumor necrosis factor (TNF-α), and Interleukins (IL-6 and IL-10)) were evaluated. Descriptive and non-parametric statistical data analysis were performed. Fifty-six subjects (19 non-caregivers, 17 geriatric caregivers, and 20 oncologic caregivers) participated. Median age (IQR) was 57 years (47-66) and 71.46% were women. Self-perceived stress was higher in oncologic caregivers than geriatric caregivers in all psychometric test analyzed (Wilcoxon Rank Sum test, p value  .05). These findings suggest that perceived stress is not homogeneous in the caregivers community and thus these two groups could be differentiated. These results provide the baseline information to initiate social actions addressed to each group of caregivers to increase their wellbeing.

  2. [Galectin-3, Markers of Oxidative Stress and Renal Dysfunction in Patients With Chronic Heart Failure].

    Science.gov (United States)

    Medvedeva, E A; Berezin, I I; Shchukin, Y V

    2017-03-01

    to determine levels of galectin-3, markers of renal dysfunction, and plasma oxidative stress; to assess their correlation in patients with chronic heart failure (CHF) of various severity. We included in this study 157 CHF patients (with documented prior myocardial infarction. Patients were divided into 3 groups according to their NYHA functional class (group 1 - class II n=60, group 2 - class III n=52, group 3 - class IV n=45). All patients underwent clinical examination, echocardiography. Laboratory parameters included measurement of plasma levels of galectin-3, NT-proBNP, as well as markers of oxidative stress (oxidized low density lipoprotein cholesterol [oxLDLC], SH-groups) and renal dysfunction (creatinine, uric acid, cystatin-C). The level of galectin-3 (median) in groups 1, 2, and 3 was 10, 19 and 38 ng/ml respectively. There were significant differences between groups (pmarkers of renal dysfunction and plasma oxidative stress.

  3. Pathophysiology and therapeutics of premature ageing in chronic kidney disease, with a focus on glycative stress.

    Science.gov (United States)

    Hirakawa, Yosuke; Jao, Tzu-Ming; Inagi, Reiko

    2017-12-01

    Chronic kidney disease (CKD) is a major concern in public health. The pathology of CKD includes premature ageing in the kidney and vessels, which results in a high risk of cardiovascular events and end-stage renal disease. Many factors are involved in premature ageing in CKD, including hormonal imbalance, glycative stress, nitrogenous metabolites, and oxidative stress. Of these, the most important role in premature ageing in CKD is played by glycative stress, namely a massive and unfavourable glycation state, since the kidney is responsible for the clearance of advanced glycation endproducts (AGEs). In an animal model, overexpression of glyoxalase I (GLO-1), a detoxifier of AGEs, has been found to alleviate premature ageing in the kidney and vessels. Both lifestyle changes and drug therapy have shown promise in overcoming premature ageing. Promising drug therapies include a GLO-1 activator and an absorbent against glycotoxin and nitrogenous metabolites. © 2017 John Wiley & Sons Australia, Ltd.

  4. [Emigration in hard conditions: the Immigrant Syndrome with chronic and multiple stress (Ulysses' Syndrome)].

    Science.gov (United States)

    Achotegui, Joseba

    2005-01-01

    During the latest years, immigrant populations have been living in very hard conditions. To million people, migration is becoming a process with a high level of stress surpassing the human being capacity of adaptation. This people are prone to suffer the Immigrant Syndrome with chronic and multiple stress and the so called Ulysses Syndrome, what is becoming a serious health problem in the countries that receive the immigrants. This situation is the by-product of the unjust globalization and of the worsening of the living and health conditions of those undergoing such a displacement. In this article, the author postulates a relationship between the high level of stress suffered by the immigrants and their presentation of psychopathological symptoms.

  5. Chronic vitamin C deficiency does not accelerate oxidative stress in ageing brains of guinea pigs

    DEFF Research Database (Denmark)

    Tveden-Nyborg, Pernille; Hasselholt, Stine; Miyashita, Namiyo

    2012-01-01

      Increased oxidative stress in the brain has consistently been implied in ageing and in several degenerative brain disorders. Acting as a pivotal antioxidant in the brain, vitamin C is preferentially retained during deficiency and may play an essential role in neuroprotection during ageing. Thus......, a lack of vitamin C could be associated with an increase in redox imbalance in the ageing brain. The present study compared oxidative stress of ageing to that of a long-term non-scorbutic vitamin C deficiency in guinea pigs. Adults (3-9 months old) were compared to old (36-42 months old) animals during...... a six-month dietary intervention by assessing vitamin C transport and redox homeostasis in the brain. In contrast to our hypothesis, chronic vitamin C deficiency did not affect the measured markers of oxidative stress in the brains of adult and aged animals. However, aged animals generally showed...

  6. The consequences of adolescent chronic unpredictable stress exposure on brain and behavior.

    Science.gov (United States)

    Hollis, F; Isgor, C; Kabbaj, M

    2013-09-26

    There is increasing evidence for adolescence as a time period vulnerable to environmental perturbations such as stress. What is unclear is the persistent nature of the effects of stress and how specific these effects are to the type of stressor. In this review, we describe the effects of chronic, unpredictable stress (CUS) exposure during adolescence on adult behavior and brain morphology and function in animal models. We provide evidence for adolescence as a critical window for the effects of physical CUS that persist into adulthood, with ramifications for morphological development, associated hippocampal-dependent tasks, and anxiety- and depressive-like behaviors. The results of this investigation are contrasted against those of social CUS stress exposure from the same time period that show reversible and, in the case of responses to drugs of abuse, potentially protective effects in adulthood. Finally, we discuss potential underlying mechanisms for these morphological and behavioral findings. It is our aim that the research highlighted in this review will aid in our understanding of the role of stress in adolescent mental health and development. This article is part of a Special Issue entitled: Stress, Emotional Behavior and the Endocannabinoid System. Copyright © 2012. Published by Elsevier Ltd.

  7. Oxidative stress and ischemia-modified albumin in chronic ischemic heart failure.

    Science.gov (United States)

    Ellidag, Hamit Yasar; Eren, Esin; Yılmaz, Necat; Cekin, Yesim

    2014-05-01

    Knowledge about the role of oxidative stress in human diseases, including cardiovascular system disorders, emphasizes the need for reliable markers of oxidative stress. Here, we evaluated the levels of the novel marker ischemia-modified albumin (IMA), albumin-adjusted IMA (adj-IMA), and the IMA/serum albumin ratio (IMAR) in patients with chronic ischemic heart failure (CIHF). A total of 55 patients with CIHF and 40 age- and sex-matched healthy individuals were included in the study. Serum levels of IMA, total antioxidant status, and total oxidant status were analyzed, and the adj-IMA level, IMAR, and oxidative stress index were calculated. Serum IMA, IMAR, total oxidant status levels, and oxidative stress index were significantly higher in patients with CIHF than in the controls (all P stress in CIHF patients. Oxidative stress may be a key factor in the development of hypoalbuminemia in CIHF. Further studies are needed to establish the relationships among IMA, albumin, and redox balance in CIHF.

  8. The Role of Neuroticism in the Maintenance of Chronic Baseline Stress Perception and Negative Affect.

    Science.gov (United States)

    Abbasi, Irum Saeed

    2016-03-04

    The influence of neuroticism on stress perception and its associated negative affect is explored in a quasi-experimental repeated measure study. The study involves manipulating the stress perception and affect of high N group (n = 24) and low N group (n = 28) three times; first, through exposure to neutral stimuli; second, through exposure to a laboratory stressor; third, through exposure to positive stimuli. The results reveal that after exposure to neutral stimuli, there is a significant difference in the baseline Perceived Stress Scores (PSS) (p = .005) and Negative Affect (NA) scores (p = .001) of the two groups. During the stress task, however, both groups show a non-significant difference in the PSS (p = .200) and NA scores (p = .367). After exposure to positive stimuli, there is a significant difference in the PSS scores (p = .001), but a non-significant difference in the NA scores (p = .661) of the two groups. When compared across three conditions, the high N group report significantly higher perceived stress (p = .002), but not significantly higher negative affect (p = .123) than the low N group. Finally for both PSS and NA scores, there is no interaction between neuroticism and any of the three treatment conditions (p = .176; p = .338, respectively). This study shows that the high N group may be at risk for health disparities due to maintaining a chronic higher baseline stress perception and negative affect state under neutral conditions, than the low N group. Implications of the study are discussed.

  9. Change in desiccation tolerance of maize embryos during development and germination at different water potential PEG-6000 in relation to oxidative process.

    Science.gov (United States)

    Huang, Hui; Song, Songquan

    2013-07-01

    Desiccation tolerance is one of the most important traits determining seed survival during storage and under stress conditions. However, the mechanism of seed desiccation tolerance is still unclear in detail. In the present study, we used a combined model system, desiccation-tolerant and -sensitive maize embryos with identical genetic background, to investigate the changes in desiccation tolerance, malonyldialdehyde (MDA) level, hydrogen peroxide (H₂O₂) content and antioxidant enzyme activity during seed development and germination in 0, -0.6 and -1.2 MPa polyethylene glycol (PEG)-6000 solutions. Our results indicated that maize embryos gradually acquired and lost desiccation tolerance during development and germination, respectively. The acquirement and loss of desiccation tolerance of embryos during development and germination were related to the ability of antioxidant enzymes including superoxide dismutase (SOD, EC 1.15.1.1), ascorbate peroxidase (APX, EC 1.11.1.11), catalase (CAT, EC 1.11.1.6), glutathione reductase (GR, EC 1.6.4.2) and dehydroascorbate reductase (DHAR, EC 1.8.5.1) to scavenge reactive oxygen species (ROS) and to control MDA content. Compared with treatment in water, PEG-6000 treatment could markedly delay the loss of desiccation tolerance of germinating embryos by delaying water uptake and time course of germination, increasing GR activity and decreasing MDA content. Our data showed the combination of antioxidant enzyme activity and MDA content is a good parameter for assessing the desiccation tolerance of maize embryos. In addition, H₂O₂ accumulated in mature embryos and PEG-treated embryos after drying, which was at least partially related to a longer embryo/seedling length in rehydration and the physiological mechanisms of priming. Copyright © 2013. Published by Elsevier Masson SAS.

  10. Chronic Psychological Stress Was Not Ameliorated by Omega-3 Eicosapentaenoic Acid (EPA

    Directory of Open Access Journals (Sweden)

    Joanne Bradbury

    2017-10-01

    Full Text Available Background: Chronic psychological stress and mental health disorders are endemic in Western culture where population dietary insufficiencies of omega-3 fatty acids (n-3FA from seafood have been observed.Objective: This study was designed to test for a causal relationship between one of the most active components of fish oil, eicosapentaenoic acid (EPA, and chronic psychological stress.Method: A randomized double-blind, placebo-controlled clinical trial with parallel-assignment to two groups was designed (Trial Id: ACTRN12610000404022. The interventions were four EPA-rich fish oil capsules per day, delivering 2.2 g/d EPA (and 0.44 g/d DHA, or identical placebo (low-phenolic olive oil capsules with 5% fish oil to aid blinding. The primary outcome was the between-group difference on the Perceived Stress Scale (PSS-10 after 12 weeks supplementation. An a priori power analysis determined that group sizes of 43 would provide 80% power to detect a significant between-group difference of 12.5%, at α = 0.05. Ninety community members (64 females, 26 males reporting chronic work stress were recruited via public advertising in northern NSW, Australia.Results: At baseline the omega-3 index (EPA + DHA as % to total fatty acids in red blood cell membranes was 5.2% in both groups (SD = 1.6% control group; 1.8% active group. After supplementation this remained stable at 5.3% (SD = 1.6% for the control group but increased to 8.9% (SD = 1.5% for the active group, demonstrating successful incorporation of EPA into cells. Intention-to-treat (ITT analysis found no significant between-group differences in PSS outcome scores post-intervention (b = 1.21, p = 0.30 after adjusting for sex (b = 2.36, p = 0.079, baseline PSS (b = 0.42, p = 0.001 and baseline logEPA [b = 1.41, p = 0.185; F(3, 86 = 8.47, p < 0.01, n = 89, R-square = 0.243].Discussion: Treatment increased cell membrane EPA but, contrary to the hypothesis, there was no effect on perceived stress. Limitations

  11. Chronic Psychological Stress Was Not Ameliorated by Omega-3 Eicosapentaenoic Acid (EPA).

    Science.gov (United States)

    Bradbury, Joanne; Myers, Stephen P; Meyer, Barbara; Brooks, Lyndon; Peake, Jonathan; Sinclair, Andrew J; Stough, Con

    2017-01-01

    Background: Chronic psychological stress and mental health disorders are endemic in Western culture where population dietary insufficiencies of omega-3 fatty acids (n-3FA) from seafood have been observed. Objective: This study was designed to test for a causal relationship between one of the most active components of fish oil, eicosapentaenoic acid (EPA), and chronic psychological stress. Method: A randomized double-blind, placebo-controlled clinical trial with parallel-assignment to two groups was designed (Trial Id: ACTRN12610000404022). The interventions were four EPA-rich fish oil capsules per day, delivering 2.2 g/d EPA (and 0.44 g/d DHA), or identical placebo (low-phenolic olive oil capsules with 5% fish oil to aid blinding). The primary outcome was the between-group difference on the Perceived Stress Scale (PSS-10) after 12 weeks supplementation. An a priori power analysis determined that group sizes of 43 would provide 80% power to detect a significant between-group difference of 12.5%, at α = 0.05. Ninety community members (64 females, 26 males) reporting chronic work stress were recruited via public advertising in northern NSW, Australia. Results: At baseline the omega-3 index (EPA + DHA as % to total fatty acids in red blood cell membranes) was 5.2% in both groups ( SD = 1.6% control group; 1.8% active group). After supplementation this remained stable at 5.3% ( SD = 1.6%) for the control group but increased to 8.9% ( SD = 1.5%) for the active group, demonstrating successful incorporation of EPA into cells. Intention-to-treat (ITT) analysis found no significant between-group differences in PSS outcome scores post-intervention ( b = 1.21, p = 0.30) after adjusting for sex ( b = 2.36, p = 0.079), baseline PSS ( b = 0.42, p = 0.001) and baseline logEPA [ b = 1.41, p = 0.185; F (3, 86) = 8.47, p stress. Limitations included an imbalance of gender in groups after randomization (68% of the males were in the placebo group). While we found no significant

  12. Chronic Juvenile Stress Produces Corticolimbic Dendritic Architectural Remodeling and Modulates Emotional Behavior in Male and Female Rats

    OpenAIRE

    Eiland, Lisa; Ramroop, Johnny; Hill, Matthew N.; Manley, Jasmine; McEwen, Bruce S.

    2011-01-01

    Nearly 12% of US children are exposed to intense adverse experiences. Research has demonstrated that these experiences can negatively impact adult health, often resulting in psychopathology. Less attention, however, is given to the impact of childhood adverse experiences on childhood health and wellbeing. Using a rodent model of chronic juvenile stress (restraint 6h daily from postnatal day 20–41), we report that chronic stress has significant immediate morbidities in both males and females d...

  13. The effect of neuroscience education on pain, disability, anxiety, and stress in chronic musculoskeletal pain.

    Science.gov (United States)

    Louw, Adriaan; Diener, Ina; Butler, David S; Puentedura, Emilio J

    2011-12-01

    To evaluate the evidence for the effectiveness of neuroscience education (NE) for pain, disability, anxiety, and stress in chronic musculoskeletal (MSK) pain. Systematic searches were conducted on Biomed Central, BMJ.com, CINAHL, the Cochrane Library, NLM Central Gateway, OVID, ProQuest (Digital Dissertations), PsycInfo, PubMed/Medline, ScienceDirect, and Web of Science. Secondary searching (PEARLing) was undertaken, whereby reference lists of the selected articles were reviewed for additional references not identified in the primary search. All experimental studies including randomized controlled trials (RCTs), nonrandomized clinical trials, and case series evaluating the effect of NE on pain, disability, anxiety, and stress for chronic MSK pain were considered for inclusion. Additional limitations: studies published in English, published within the last 10 years, and patients older than 18 years. No limitations were set on specific outcome measures of pain, disability, anxiety, and stress. Data were extracted using the participants, interventions, comparison, and outcomes (PICO) approach. Methodological quality was assessed by 2 reviewers using the Critical Review Form-Quantitative Studies. This review includes 8 studies comprising 6 high-quality RCTs, 1 pseudo-RCT, and 1 comparative study involving 401 subjects. Most articles were of good quality, with no studies rated as poor or fair. Heterogeneity across the studies with respect to participants, interventions evaluated, and outcome measures used prevented meta-analyses. Narrative synthesis of results, based on effect size, established compelling evidence that NE may be effective in reducing pain ratings, increasing function, addressing catastrophization, and improving movement in chronic MSK pain. For chronic MSK pain disorders, there is compelling evidence that an educational strategy addressing neurophysiology and neurobiology of pain can have a positive effect on pain, disability, catastrophization, and

  14. Ghrelin alleviates anxiety- and depression-like behaviors induced by chronic unpredictable mild stress in rodents.

    Science.gov (United States)

    Huang, Hui-Jie; Zhu, Xiao-Cang; Han, Qiu-Qin; Wang, Ya-Lin; Yue, Na; Wang, Jing; Yu, Rui; Li, Bing; Wu, Gen-Cheng; Liu, Qiong; Yu, Jin

    2017-05-30

    As a regulator of food intake, ghrelin also plays a key role in mood disorders. Previous studies reported that acute ghrelin administration defends against depressive symptoms of chronic stress. However, the effects of long-term ghrelin on rodents under chronic stress hasn't been revealed. In this study, we found chronic peripheral administration of ghrelin (5nmol/kg/day for 2 weeks, i.p.) could alleviate anxiety- and depression-like behaviors induced by chronic unpredictable mild stress (CUMS). The depression-like behaviors were assessed by the forced swimming test (FST), and anxiety-like behaviors were assessed by the open field test (OFT) and the elevated plus maze test (EPM). Meanwhile, we observed that peripheral acylated ghrelin, together with gastral and hippocampal ghrelin prepropeptide mRNA level, were significantly up-regulated in CUMS mice. Besides, the increased protein level of growth hormone secretagogue receptor (GHSR) in hippocampus were also detected. These results suggested that the endogenous ghrelin/GHSR pathway activated by CUMS plays a role in homeostasis. Further results showed that central treatment of ghrelin (10μg/rat/day for 2 weeks, i.c.v.) or GHRP-6 (the agonist of GHSR, 10μg/rat/day for 2 weeks, i.c.v.) significantly alleviated the depression-like behaviors induced by CUMS in FST and sucrose preference test (SPT). Based on these results, we concluded that central GHSR is involved in the antidepressant-like effect of exogenous ghrelin treatment, and ghrelin/GHSR may have the inherent neuromodulatory properties against depressive symptoms. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Feasible study on desiccant wheel with CO2 heat pump

    Science.gov (United States)

    Liu, Yefeng; Meng, Deren; Sun, Ying

    2017-12-01

    A kind of desiccant wheel with CO2 heat pump is proposed. The main features of this proposed system include: (1) there are two optional ways of desiccant dehumidification and cooling dehumidification; (2) for the subsystem of desiccant dehumidification process, the air regeneration process occurs inside a closed loop, and a CO2 heat pump is utilized inside this loop for air regeneration, which has the potential to significantly reduce energy consumption compared to a traditional regeneration process. The operating performance of the system is simulated and analysed. Compared to the traditional vapor compression air conditioning system, the hybrid system can save approximately 50% to 90% of energy.

  16. Chronic family stress moderates the association between a TOMM40 variant and triglyceride levels in two independent Caucasian samples

    DEFF Research Database (Denmark)

    Jiang, Rong; Brummett, Beverly H; Hauser, Elizabeth R

    2013-01-01

    TOMM40 SNP rs157580 has been associated with triglyceride levels in genome-wide association studies (GWAS). Chronic caregiving stress moderates the association between triglyceride levels and a nearby SNP rs439401 that is associated with triglyceride levels in GWAS. Here, we report data from two...... independent Caucasian samples (242 U.S. women and men; 466 Danish men) testing the hypothesis that chronic family stress also moderates the association between rs157580 and triglyceride levels. The interaction of rs157580 and family stress in predicting triglyceride levels was statistically significant...... in the U.S. sample (p=0.004) and marginally significant (p=0.075) in the Danish sample. The G allele of rs157580 was associated with increased triglyceride levels among family stressed cases in both samples compared with A/A cases, but not among controls. Chronic family stress moderates the association...

  17. Re-evaluation of the interrelationships among the behavioral tests in rats exposed to chronic unpredictable mild stress.

    Directory of Open Access Journals (Sweden)

    Congli Hu

    Full Text Available The chronic unpredictable mild stress model of depression has been widely used as an experimental tool to investigate human psychopathology. Our objective was to provide an update on the validity and reliability of the chronic unpredictable mild stress model, by analyzing the interrelationships among the indexes using stepwise discriminant analysis and Pearson correlation coefficient to examine the possible combinations. We evaluated the depressive rats in both the presence and the absence of chronic unpredictable mild stress, using weight change, percentage of sucrose preference, coat state, splash test, open-field test, elevated plus-maze test, forced swimming test, and Morris water maze test. The results showed that 6-week-long chronic unpredictable mild stress produces significant depression and anxiety-like behavior. The combination of body weight change, percentage of sucrose preference, coat state score, open-field score, grooming latency of splash test, immobility time in force swimming test, and platform crossing in the Morris water maze test can effectively discriminate between normal and chronic unpredictable mild stress rats. Strong interrelationships were noted among these indexes in both open-field test and elevated plus-maze test. In conclusion, there might be certain criteria for the combination of behavioral endpoints, which is advantageous to more effectively and reliably assess the chronic unpredictable mild stress induced depression model.

  18. Central ghrelin signaling mediates the metabolic response of C57BL/6 male mice to chronic social defeat stress.

    Science.gov (United States)

    Patterson, Z R; Khazall, R; Mackay, H; Anisman, H; Abizaid, A

    2013-03-01

    Chronic stressors promote metabolic disturbances, including obesity and metabolic syndrome. Ghrelin, a peptide that promotes appetite and the accumulation of adipose tissue, is also secreted in response to stressors to protect the brain and peripheral tissues from the effects of these stressors. Here we demonstrate that elevated ghrelin levels produced by chronic exposure to social stress are associated with increased caloric intake and body weight gain in male C57BL mice. In contrast, stressed mice lacking ghrelin receptors (GHSR KO mice) or C57BL mice receiving chronic intracerebroventricular delivery of the ghrelin receptor antagonist [d-Lys(3)]-GHRP-6 show attenuated weight gain and feeding responses under the same social stress paradigm. Interestingly, stressed GHSR KO mice showed depleted sc and intrascapular brown fat depots, whereas stressed young wild-type mice did not. In old wild-type mice, chronic social defeat increased visceral and intrascapular brown fat depots in association with increases in obesity markers like hyperleptinemia and hyperinsulinemia along with increased hypothalamic expression of neuropeptide Y and Agouti related peptide. Importantly, the elevated expression of these peptides persisted least for 2 weeks after cessation of the stressor regimen. In contrast, old GHSR KO mice did not show these alterations after chronic social defeat. These results suggest that ghrelin plays an important role in the metabolic adaptations necessary to meet the energetic demands posed by stressors, but chronic exposure to stress-induced ghrelin elevations ultimately could lead to long lasting metabolic dysfunctions.

  19. Increased anxiety, voluntary alcohol consumption and ethanol-induced place preference in mice following chronic psychosocial stress.

    Science.gov (United States)

    Bahi, Amine

    2013-07-01

    Stress exposure is known to be a risk factor for alcohol use and anxiety disorders. Comorbid chronic stress and alcohol dependence may lead to a complicated and potentially severe treatment profile. To gain an understanding of the interaction between chronic psychosocial stress and drug exposure, we studied the effects of concomitant chronic stress exposure on alcohol reward using two-bottle choice and ethanol-conditioned place preference (CPP). The study consisted of exposure of the chronic subordinate colony (CSC) mice "intruders" to an aggressive "resident" mouse for 19 consecutive days. Control mice were single housed (SHC). Ethanol consumption using two-bottle choice paradigm and ethanol CPP acquisition was assessed at the end of this time period. As expected, CSC exposure increased anxiety-like behavior and reduced weight gain as compared to SHC controls. Importantly, in the two-bottle choice procedure, CSC mice showed higher alcohol intake than SHC. When testing their response to ethanol-induced CPP, CSC mice achieved higher preference for the ethanol-paired chamber. In fact, CSC exposure increased ethanol-CPP acquisition. Taken together, these data demonstrate the long-term consequences of chronic psychosocial stress on alcohol intake in male mice, suggesting chronic stress as a risk factor for developing alcohol consumption and/or anxiety disorders.

  20. The potential role of exercise in chronic stress-related changes in AMPA receptor phenotype underlying synaptic plasticity.

    Science.gov (United States)

    Leem, Yea-Hyun

    2017-12-31

    Chronic stress can cause disturbances in synaptic plasticity, such as longterm potentiation, along with behavioral defects including memory deficits. One major mechanism sustaining synaptic plasticity involves the dynamics and contents of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) in the central nervous system. In particular, chronic stress-induced disruption of AMPARs includes it abnormal expression, trafficking, and calcium conductance at glutamatergic synapses, which contributes to synaptic plasticity at excitatory synapses. Exercise has the effect of promoting synaptic plasticity in neurons. However, the contribution of exercise to AMPAR behavior under chronic stressful maladaptation remains unclear. The present article reviews the information about the chronic stress-related synaptic plasticity and the role of exercise from the previous-published articles. AMPAR-mediated synaptic transmission is an important for chronic stress-related changes of synaptic plasticity, and exercise may at least partly contribute to these episodes. The present article discusses the relationship between AMPARs and synaptic plasticity in chronic stress, as well as the potential role of exercise.

  1. Inversion 2La is associated with enhanced desiccation resistance in Anopheles gambiae

    Directory of Open Access Journals (Sweden)

    Costantini Carlo

    2009-09-01

    Full Text Available Abstract Background Anopheles gambiae, the principal vector of malignant malaria in Africa, occupies a wide range of habitats. Environmental flexibility may be conferred by a number of chromosomal inversions non-randomly associated with aridity, including 2La. The purpose of this study was to determine the physiological mechanisms associated with the 2La inversion that may result in the preferential survival of its carriers in hygrically-stressful environments. Methods Two homokaryotypic populations of A. gambiae (inverted 2La and standard 2L+a were created from a parental laboratory colony polymorphic for 2La and standard for all other known inversions. Desiccation resistance, water, energy and dry mass of adult females of both populations were compared at several ages and following acclimation to a more arid environment. Results Females carrying 2La were significantly more resistant to desiccation than 2L+a females at emergence and four days post-emergence, for different reasons. Teneral 2La females had lower rates of water loss than their 2L+a counterparts, while at four days, 2La females had higher initial water content. No differences in desiccation resistance were found at eight days, with or without acclimation. However, acclimation resulted in both populations significantly reducing their rates of water loss and increasing their desiccation resistance. Acclimation had contrasting effects on the body characteristics of the two populations: 2La females boosted their glycogen stores and decreased lipids, whereas 2La females did the contrary. Conclusion Variation in rates of water loss and response to acclimation are associated with alternative arrangements of the 2La inversion. Understanding the mechanisms underlying these traits will help explain how inversion polymorphisms permit exploitation of a heterogeneous environment by this disease vector.

  2. Chronic stress, inflammation, and glucose regulation in U.S. Hispanics from the HCHS/SOL Sociocultural Ancillary Study.

    Science.gov (United States)

    McCurley, Jessica L; Mills, Paul J; Roesch, Scott C; Carnethon, Mercedes; Giacinto, Rebeca E; Isasi, Carmen R; Teng, Yanping; Sotres-Alvarez, Daniela; Llabre, Maria M; Penedo, Frank J; Schneiderman, Neil; Gallo, Linda C

    2015-08-01

    Diabetes prevalence is rising rapidly, and diabetes disproportionately affects Hispanics and other underserved groups. Chronic stress may contribute to diabetes risk, but few studies have examined this relationship in U.S. Hispanics. We examined associations of chronic stress with fasting glucose, glucose tolerance, and glycosylated hemoglobin (HbA1c) in Hispanics without diabetes, and also assessed indirect effects of stress through inflammation (CRP). Participants were 3,923 men and women, aged 18-74, without diabetes, from the four U.S. field centers (Bronx, NY; Chicago, IL; Miami, FL; San Diego, CA) of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Sociocultural Ancillary study. Participants completed a measure of chronic life stress and a physical exam with oral glucose tolerance test. In a multivariate regression analysis with adjustment for demographic and health covariates, higher chronic stress was related to higher fasting glucose (standardized regression coefficient: β = .09, p stress through inflammation. Findings suggest that higher chronic stress is associated with poorer glucose regulation in Hispanics, prior to the onset of a clinical diabetes diagnosis. © 2015 Society for Psychophysiological Research.

  3. Increased markers of oxidative stress in plasma of patients with chronic pancreatitis.

    Science.gov (United States)

    Podborska, Martina; Sevcikova, Arona; Trna, Jan; Dite, Petr; Lojek, Antonin; Kubala, Lukas

    2009-01-01

    Chronic pancreatitis (CP) is a heterogeneous disease defined as chronic inflammatory changes of the pancreatic tissue caused by variety of aetiologies. Oxidative stress accompanying the inflammatory processes has been suggested as an important factor contributing to CP development. The aim of this study was to determine levels of lipid peroxidation products malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), together with nitrites and the total antioxidant capacity in the plasma of patients with CP and control subjects. One hundred and five patients with chronic pancreatitis and twenty seven healthy controls were included into this study. Levels of MDA and 4-HNE were analyzed using high-performance liquid chromatography. The total antioxidant capacity of plasma against peroxyl radicals was evaluated using chemiluminescent determination. Nitrites were determined using Griess reaction. Biochemical and haematological parameters were measured by standard methods. The plasma levels of both MDA and 4-HNE, together with the plasma levels of nitrites, were significantly higher in CP patients, compared to healthy controls. The total antioxidant capacity did not differ significantly. Biochemical parameters were in the normal range. The MDA and 4-HNE levels correlated positively with the levels of high-density lipoprotein cholesterol. Nitrite levels correlated positively with C-reactive protein, total white blood cells, and triglycerides. The significantly increased plasma levels of MDA, 4-HNE, and nitrites indicate that oxidative stress is present in patients with CP and that it may play a role in initiation and maintenance of inflammation within the pancreatic tissue in CP patients.

  4. Implications of red Panax ginseng in oxidative stress associated chronic diseases

    Directory of Open Access Journals (Sweden)

    Yoon-Mi Lee

    2017-04-01

    Full Text Available The steaming process of Panax ginseng has been reported to increase its major known bioactive components, ginsenosides, and, therefore, its biological properties as compared to regular Panax ginseng. Biological functions of red Panax ginseng attenuating pro-oxidant environments associated with chronic diseases are of particular interest, since oxidative stress can be a key contributor to the pathogenesis of chronic diseases. Additionally, proper utilization of various biomarkers for evaluating antioxidant activities in natural products, such as ginseng, can also be important to providing validity to their activities. Thus, studies on the effects of red ginseng against various diseases as determined in cell lines, animal models, and humans were reviewed, along with applied biomarkers for verifying such effects. Limitations and future considerations of studying red ginseng were been discussed. Although further clinical studies are warranted, red ginseng appears to be beneficial for attenuating disease-associated symptoms via its antioxidant activities, as well as for preventing oxidative stress-associated chronic diseases.

  5. Personality variables in coping with the stress of a spouse's chronic illness.

    Science.gov (United States)

    Schoeneman, S Z; Reznikoff, M; Bacon, S J

    1983-05-01

    Identified systematically those spouses of male VA hemodialysis patients who are at risk for experiencing difficulties in adapting to their husband's chronic kidney failure and hemodialysis treatment. To this end, an exploration was made of personality variables that might enhance a spouse's ability to cope with the unique stress of living with chronic illness. Fifty-six wives of VA dialysis patients were administered the Rotter Internal-External Locus of Control Scale (I-E), the Multidimensional Locus of Control Scale (MLC), the Multidimensional Health Locus of Control Scale (MHLC), the State-Trait Anxiety Inventory (STAI), and the Beck Depression Inventory (BDI). Significant relationships were found between I-E scores and all measures of emotional adjustment (state anxiety, trait anxiety, and depression) for the entire sample of spouses in general, and also for a subgroup of home dialysis spouses who were analyzed separately. Results were discussed in terms of the role that locus of control orientation plays in mediating the stress of living with chronic illness, as well as the failure to find relationships between adjustment and the MLC or the area-specific MHLC.

  6. Proteomics of seed development, desiccation tolerance, germination and vigor.

    Science.gov (United States)

    Wang, Wei-Qing; Liu, Shu-Jun; Song, Song-Quan; Møller, Ian Max

    2015-01-01

    Proteomics, the large-scale study of the total complement of proteins in a given sample, has been applied to all aspects of seed biology mainly using model species such as Arabidopsis or important agricultural crops such as corn and rice. Proteins extracted from the sample have typically been separated and quantified by 2-dimensional polyacrylamide gel electrophoresis followed by liquid chromatography and mass spectrometry to identify the proteins in the gel spots. In this way, qualitative and quantitative changes in the proteome during seed development, desiccation tolerance, germination, dormancy release, vigor alteration and responses to environmental factors have all been studied. Many proteins or biological processes potentially important for each seed process have been highlighted by these studies, which greatly expands our knowledge of seed biology. Proteins that have been identified to be particularly important for at least two of the seed processes are involved in detoxification of reactive oxygen species, the cytoskeleton, glycolysis, protein biosynthesis, post-translational modifications, methionine metabolism, and late embryogenesis-abundant (LEA) proteins. It will be useful for molecular biologists and molecular plant breeders to identify and study genes encoding particularly interesting target proteins with the aim to improve the yield, stress tolerance or other critical properties of our crop species. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  7. Value of stress ultrasound for the diagnosis of chronic ankle instability compared to manual anterior drawer test, stress radiography, magnetic resonance imaging, and arthroscopy.

    Science.gov (United States)

    Cho, Jae Ho; Lee, Doo Hyung; Song, Hyung Keun; Bang, Joon Young; Lee, Kyung Tai; Park, Young Uk

    2016-04-01

    Clinicians frequently diagnose chronic ankle instability using the manual anterior drawer test and stress radiography. However, both examinations can yield incorrect results and do not reveal the extent of ankle instability. Stress ultrasound has been reported to be a new diagnostic tool for the diagnosis of chronic ankle instability. The purpose of this study was to assess the diagnostic value of stress ultrasound for chronic ankle instability compared to the manual anterior drawer test, stress radiography, magnetic resonance imaging (MRI), and arthroscopy. Twenty-eight consecutive patients who underwent ankle arthroscopy and subsequent modified Broström repair for treatment of chronic ankle instability were included. The arthroscopic findings were used as the reference standard. A standardized physical examination (manual anterior drawer test), stress radiography, MRI, and stress ultrasound were performed to assess the anterior talofibular ligament (ATFL) prior to operation. Ultrasound images were taken in the resting position and the maximal anterior drawer position. Grade 3 lateral instability was verified arthroscopically in all 28 cases with a clinical diagnosis (100%). Twenty-two cases showed grade III instability on the manual anterior drawer test (78.6%). Twenty-four cases displayed anterior translation exceeding 5 mm on stress radiography (86%), and talar tilt angle exceeded 15° in three cases (11 %). Nineteen cases displayed a partial chronic tear (change in thickness or signal intensity), and nine cases displayed complete tear on MRI (100%). Lax and wavy ATFL was evident on stress ultrasound in all cases (100 %). The mean value of the ATFL length was 2.8 ± 0.3 cm for the stressed condition and 2.1 ± 0.2 cm for the resting condition (p radiography. III.

  8. Hypothermia after chronic mild stress exposure in rats with a history of postnatal maternal separations.

    Science.gov (United States)

    Mrdalj, Jelena; Lundegaard Mattson, Ase; Murison, Robert; Konow Jellestad, Finn; Milde, Anne Marita; Pallesen, Ståle; Ursin, Reidun; Bjorvatn, Bjørn; Grønli, Janne

    2014-03-01

    The circadian system develops and changes in a gradual and programmed process over the lifespan. Early in life, maternal care represents an important zeitgeber and thus contributes to the development of circadian rhythmicity. Exposure to early life stress may affect circadian processes and induce a latent circadian disturbance evident after exposure to later life stress. Disturbance of the normal regulation of circadian rhythmicity is surmised to be an etiological factor in depression. We used postnatal maternal separation in rats to investigate how the early life environment might modify the circadian response to later life unpredictable and chronic stress. During postnatal days 2-14, male Wistar rats (n = 8 per group) were daily separated from their mothers for a period of either 180 min (long maternal separation; LMS) or 10 min (brief maternal separation; BMS). In adulthood, rats were exposed to chronic mild stress (CMS) for 4 weeks. Body temperature, locomotor activity and heart rate were measured and compared before and after CMS exposure. LMS offspring showed a delayed body temperature acrophase compared to BMS offspring. Otherwise, adult LMS and BMS offspring demonstrated similar diurnal rhythms of body temperature, locomotor activity and heart rate. Exposure to CMS provoked a stronger and longer lasting hypothermia in LMS rats than in BMS rats. The thermoregulatory response appears to be moderated by maternal care following reunion, an observation made in the LMS group only. The results show that early life stress (LMS) in an early developmental stage induced a thermoregulatory disturbance evident upon exposure to unpredictable adult life stressors.

  9. Oxidative Stress and Nucleic Acid Oxidation in Patients with Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Chih-Chien Sung

    2013-01-01

    Full Text Available Patients with chronic kidney disease (CKD have high cardiovascular mortality and morbidity and a high risk for developing malignancy. Excessive oxidative stress is thought to play a major role in elevating these risks by increasing oxidative nucleic acid damage. Oxidative stress results from an imbalance between reactive oxygen/nitrogen species (RONS production and antioxidant defense mechanisms and can cause vascular and tissue injuries as well as nucleic acid damage in CKD patients. The increased production of RONS, impaired nonenzymatic or enzymatic antioxidant defense mechanisms, and other risk factors including gene polymorphisms, uremic toxins (indoxyl sulfate, deficiency of arylesterase/paraoxonase, hyperhomocysteinemia, dialysis-associated membrane bioincompatibility, and endotoxin in patients with CKD can inhibit normal cell function by damaging cell lipids, arachidonic acid derivatives, carbohydrates, proteins, amino acids, and nucleic acids. Several clinical biomarkers and techniques have been used to detect the antioxidant status and oxidative stress/oxidative nucleic acid damage associated with long-term complications such as inflammation, atherosclerosis, amyloidosis, and malignancy in CKD patients. Antioxidant therapies have been studied to reduce the oxidative stress and nucleic acid oxidation in patients with CKD, including alpha-tocopherol, N-acetylcysteine, ascorbic acid, glutathione, folic acid, bardoxolone methyl, angiotensin-converting enzyme inhibitor, and providing better dialysis strategies. This paper provides an overview of radical production, antioxidant defence, pathogenesis and biomarkers of oxidative stress in patients with CKD, and possible antioxidant therapies.

  10. Oxidative stress is associated with decreased heart rate variability in patients with chronic kidney disease.

    Science.gov (United States)

    Fadaee, Shannon B; Beetham, Kassia S; Howden, Erin J; Stanton, Tony; Isbel, Nicole M; Coombes, Jeff S

    2017-09-01

    Elevated oxidative stress and reduced heart rate variability (HRV) is prevalent in patients with chronic kidney disease (CKD) and is associated with increased morbidity and mortality. Previous studies have identified a positive association between elevated oxidative stress and autonomic dysfunction, however this relationship has not yet been investigated in the CKD population. Plasma was collected from 78 patients with stage 3-4 CKD (estimated glomerular filtration rate 25-60 ml/min/1.73 m 2 ) for the assessment of oxidative stress, including plasma total F2-isoprostanes, glutathione peroxidase activity and total antioxidant capacity. Time and frequency HRV parameters were measured from a three lead electrocardiogram. Participants with elevated F2-isoprostanes had reduced HRV compared to patients with normal levels of F2-isoprostanes. A number of HRV parameters were found to be inversely correlated with F2-isoprostanes in all CKD patients, including SDNN (r = -0.337; P stress is significantly and independently associated with HRV in patients with CKD. Identifying oxidative stress in the pathogenesis of autonomic dysfunction may help target therapeutic strategies.

  11. Chromatin remodeling regulates catalase expression during cancer cells adaptation to chronic oxidative stress.

    Science.gov (United States)

    Glorieux, Christophe; Sandoval, Juan Marcelo; Fattaccioli, Antoine; Dejeans, Nicolas; Garbe, James C; Dieu, Marc; Verrax, Julien; Renard, Patricia; Huang, Peng; Calderon, Pedro Buc

    2016-10-01

    Regulation of ROS metabolism plays a major role in cellular adaptation to oxidative stress in cancer cells, but the molecular mechanism that regulates catalase, a key antioxidant enzyme responsible for conversion of hydrogen peroxide to water and oxygen, remains to be elucidated. Therefore, we investigated the transcriptional regulatory mechanism controlling catalase expression in three human mammary cell lines: the normal mammary epithelial 250MK primary cells, the breast adenocarcinoma MCF-7 cells and an experimental model of MCF-7 cells resistant against oxidative stress resulting from chronic exposure to H 2 O 2 (Resox), in which catalase was overexpressed. Here we identify a novel promoter region responsible for the regulation of catalase expression at -1518/-1226 locus and the key molecules that interact with this promoter and affect catalase transcription. We show that the AP-1 family member JunB and retinoic acid receptor alpha (RARα) mediate catalase transcriptional activation and repression, respectively, by controlling chromatin remodeling through a histone deacetylases-dependent mechanism. This regulatory mechanism plays an important role in redox adaptation to chronic exposure to H 2 O 2 in breast cancer cells. Our study suggests that cancer adaptation to oxidative stress may be regulated by transcriptional factors through chromatin remodeling, and reveals a potential new mechanism to target cancer cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Behavior and influence of desiccation cracking in loess landfill covers

    Science.gov (United States)

    Wu, Tao; Lan, Ji-wu; Qiu, Qing-wen; He, Hai-jie; Li, He

    2017-11-01

    In the northwest region of China, loess was the main closure cover material of local landfills. Tests in a full-scale testing facility were conducted to investigate the behavior and influence of desiccation cracking in loess landfill covers. The desiccation cracks in the loess landfill cover intersected with T-shape, and the intersection angles were close to 90 degrees. The desiccation cracks formed as a result of drying, and would heal with the increase of moisture content of the loess. In addition, desiccation cracking in loess covers would promote the formation of preferential flow channels. As a consequence, the gas permeability of the loess cover was improved, and methane emissions increased obviously.

  13. Desiccant Dewpoint Cooling System Independent of External Water Sources

    DEFF Research Database (Denmark)

    Bellemo, Lorenzo; Elmegaard, Brian; Markussen, Wiebke B.

    2015-01-01

    This paper presents a patent pending technical solution aiming to make desiccant cooling systems independent of external water sources, hence solving problems of water availability, cost and treatment that can decrease the system attractiveness. The solution consists in condensing water from...... the air that regenerates the desiccant dehumidifier, and using it for running the evaporative coolers in the system. A closed regeneration circuit is used for maximizing the amount of condensed water. This solution is applied to a system with a desiccant wheel dehumidifier and a dew point cooler, termed...... desiccant dew-point cooling system, for demonstrating its function and applicability. Simulations are carried out for varying outdoor conditions under constant supply conditions. The results show that the system is independent of external water supply for the majority of simulated conditions. In comparison...

  14. Chronic and Acute Stress, Gender, and Serotonin Transporter Gene-Environment Interactions Predicting Depression Symptoms in Youth

    Science.gov (United States)

    Hammen, Constance; Brennan, Patricia A.; Keenan-Miller, Danielle; Hazel, Nicholas A.; Najman, Jake M.

    2010-01-01

    Background: Many recent studies of serotonin transporter gene by environment effects predicting depression have used stress assessments with undefined or poor psychometric methods, possibly contributing to wide variation in findings. The present study attempted to distinguish between effects of acute and chronic stress to predict depressive…

  15. Chronic hypoxia during gestation enhances uterine arterial myogenic tone via heightened oxidative stress.

    Directory of Open Access Journals (Sweden)

    Daliao Xiao

    Full Text Available Chronic hypoxia during gestation has profound adverse effects on the adaptation of uteroplacental circulation in pregnancy. Yet, the underlying mechanisms are not fully understood. The present study tested the hypothesis that enhanced production of reactive oxygen species (ROS in uterine arteries plays a critical role in the maladaptation of uterine circulation associated with chronic hypoxia. Uterine arteries were isolated from nonpregnant and near-term pregnant sheep maintained at sea level (~300 m or exposed to high-altitude (3801 m hypoxia for 110 days. Hypoxia significantly increased ROS production in uterine arteries of pregnant, but not nonpregnant, sheep. This was associated with a significant increase in NADPH oxidase (Nox 2, but not Nox1 or Nox4, protein abundance and total Nox activity in uterine arteries of pregnant animals. Chronic hypoxia significantly increased pressure-dependent uterine arterial myogenic tone in pregnant sheep, which was abrogated by a Nox inhibitor apocynin. Additionally, the hypoxia-induced increase in myogenic reactivity of uterine arteries to phorbol 12,13-dibutyrate in pregnant sheep was blocked by apocynin and tempol. In consistence with the myogenic responses, the hypoxia-mediated down-regulation of BKCa channel activity in uterine arteries of pregnant animals was reversed by apocynin. The findings suggest that heightened oxidative stress in uterine arteries plays a key role in suppressing the BKCa channel activity, resulting in increased myogenic reactivity and maladaptation of uteroplacental circulation caused by chronic hypoxia during gestation.

  16. The Impact of Emotional Characteristics in the Chronicity of Posttraumatic Stress Disorder.

    Science.gov (United States)

    Milenković, Tatjana; Jovanović, Aleksandar

    2016-06-01

    The research objective was to identify overstated emotional characteristics in armed conflict veterans as well as both the similarities and differences in personality profiles between patients suffering from acute and chronic forms of posttraumatic stress disorder (PTSD). Our study's sample consisted of 60 participants in the armed conflict in Kosovo that lasted from 28 February, 1998 until 11 June, 1999. All of them were diagnosed with PTSD, during the six months period after their return from active duty. In 2014 we retested the same subjects to see their current psychological state. Diagnoses of PTSD were made using Structure Clinical Interview for DSM-IV (SCID-I), while the assessment of emotional characteristics was made using Plutchik's emotion profile index (PIE). We established no statistically significant difference in PIE profiles between both groups in recent re-testing. The only significant difference as per PIE classification was found earlier when the subjects were initially diagnosed. The amplified emotional dimension was exploration, and only the group of chronic PTSD patients displayed significantly higher values (pPTSD. The only noted difference is in the significantly higher values of exploration emotional dimension, but only at the time when they were first given initial diagnosis, and only in the group of subjects who later developed the chronic form of PTSD which can indicate that exploration is a factor of vulnerability which is important in chronicity.

  17. Regulation of ethanol intake under chronic mild stress: roles of dopamine receptors and transporters

    Science.gov (United States)

    Delis, Foteini; Rombola, Christina; Bellezza, Robert; Rosko, Lauren; Grandy, David K.; Volkow, Nora D.; Thanos, Panayotis K.

    2015-01-01

    Studies have shown that exposure to chronic mild stress decreases ethanol intake and preference in dopamine D2 receptor wild-type mice (Drd2+/+), while it increases intake in heterozygous (Drd2+/−) and knockout (Drd2−/−) mice. Dopaminergic neurotransmission in the basal forebrain plays a major role in the reinforcing actions of ethanol as well as in brain responses to stress. In order to identify neurochemical changes associated with the regulation of ethanol intake, we used in vitro receptor autoradiography to measure the levels and distribution of dopamine D1 and D2 receptors and dopamine transporters (DAT). Receptor levels were measured in the basal forebrain of Drd2+/+, Drd2+/−, and Drd2−/− mice belonging to one of four groups: control (C), ethanol intake (E), chronic mild stress exposure (S), and ethanol intake under chronic mild stress (ES). D2 receptor levels were higher in the lateral and medial striatum of Drd2+/+ ES mice, compared with Drd2+/+ E mice. Ethanol intake in Drd2+/+ mice was negatively correlated with striatal D2 receptor levels. D2 receptor levels in Drd2+/− mice were the same among the four treatment groups. DAT levels were lower in Drd2+/− C and Drd2−/− C mice, compared with Drd2+/+ C mice. Among Drd2+/− mice, S and ES groups had higher DAT levels compared with C and E groups in most regions examined. In Drd2−/− mice, ethanol intake was positively correlated with DAT levels in all regions studied. D1 receptor levels were lower in Drd2+/− and Drd2−/− mice, compared with Drd2+/+, in all regions examined and remained unaffected by all treatments. The results suggest that in normal mice, ethanol intake is associated with D2 receptor-mediated neurotransmission, which exerts a protective effect against ethanol overconsumption under stress. In mice with low Drd2 expression, where DRD2 levels are not further modulated, ethanol intake is associated with DAT function which is upregulated under stress leading to ethanol

  18. Chronic Stress Is Associated with Indicators of Diet Quality in Habitual Breakfast Skippers.

    Science.gov (United States)

    Widaman, Adrianne M; Witbracht, Megan G; Forester, Shavawn M; Laugero, Kevin D; Keim, Nancy L

    2016-11-01

    Previous studies suggest skipping breakfast is associated with lower diet quality, but possible reasons underlying this relationship are not clear. Our aim was to determine the relationship between chronic stress and variations in diet quality in the context of breakfast eating or breakfast skipping. Based on morning eating habits, 40 breakfast eaters and 35 breakfast skippers participated in a cross-sectional study. Diet assessment was based on unannounced 24-hour recalls. Women, ages 18 to 45 years, with a body mass index (calculated as kg/m 2 ) Eating Index 2010 (HEI-2010). Stress and executive function were evaluated with validated questionnaires and a computer-based task, respectively. Diet characteristics of breakfast eating and breakfast skipping were evaluated as nutrient densities (amounts per 1,000 kcal) and compared using a one-way analysis of covariance, with body mass index as covariate. Diet and stress variable associations were assessed using Pearson correlations. Despite no observed differences in daily energy intake between breakfast skipping and breakfast eating, overall diet quality (P=0.001), whole grains (P=0.002), fruit (P=0.002), empty calories (P=0.050), fiber (P=0.001), calcium (P=0.001), potassium (P=0.033), and folate (P=0.013) intakes were higher in breakfast eating. In the evening, breakfast skipping consumed more added sugars (P=0.012) and saturated fat (P=0.006). In breakfast skipping, reported stress was associated with empty calories (r=-0.39; P=0.027) and evening intake of added sugars (r=0.501; P=0.005). These relationships were not observed in breakfast eating. Breakfast skippers were less likely to meet the Dietary Guidelines for Americans and consumed more empty calories at night. Chronic stress was related to evening eating choices and overall empty calories in the diet of breakfast skippers, whereas breakfast eaters' dietary intake did not appear to be affected by chronic stress. Copyright © 2016 Academy of Nutrition and

  19. TBHQ Alleviated Endoplasmic Reticulum Stress-Apoptosis and Oxidative Stress by PERK-Nrf2 Crosstalk in Methamphetamine-Induced Chronic Pulmonary Toxicity

    Directory of Open Access Journals (Sweden)

    Yun Wang

    2017-01-01

    Full Text Available Methamphetamine (MA leads to cardiac and pulmonary toxicity expressed as increases in inflammatory responses and oxidative stress. However, some interactions may exist between oxidative stress and endoplasmic reticulum stress (ERS. The current study is designed to investigate if both oxidative stress and ERS are involved in MA-induced chronic pulmonary toxicity and if antioxidant tertiary butylhydroquinone (TBHQ alleviated ERS-apoptosis and oxidative stress by PERK-Nrf2 crosstalk. In this study, the rats were randomly divided into control group, MA-treated group (MA, and MA plus TBHQ-treated group (MA + TBHQ. Chronic exposure to MA resulted in slower growth of weight and pulmonary toxicity of the rats by increasing the pulmonary arterial pressure, promoting the hypertrophy of right ventricle and the remodeling of pulmonary arteries. MA inhibited the Nrf2-mediated antioxidative stress by downregulation of Nrf2, GCS, and HO-1 and upregulation of SOD2. MA increased GRP78 to induce ERS. Overexpression and phosphorylation of PERK rapidly phosphorylated eIF2α, increased ATF4, CHOP, bax, caspase 3, and caspase 12, and decreased bcl-2. These changes can be reversed by antioxidant TBHQ through upregulating expression of Nrf2. The above results indicated that TBHQ can alleviate MA-induced oxidative stress which can accelerate ERS to initiate PERK-dependent apoptosis and that PERK/Nrf2 is likely to be the key crosstalk between oxidative stress and ERS in MA-induced chronic pulmonary toxicity.

  20. Running exercise mitigates the negative consequences of chronic stress on dorsal hippocampal long-term potentiation in male mice.

    Science.gov (United States)

    Miller, Roxanne M; Marriott, David; Trotter, Jacob; Hammond, Tyler; Lyman, Dane; Call, Timothy; Walker, Bethany; Christensen, Nathanael; Haynie, Deson; Badura, Zoie; Homan, Morgan; Edwards, Jeffrey G

    2018-03-01

    In the hippocampus, learning and memory are likely mediated by synaptic plasticity, known as long-term potentiation (LTP). While chronic intermittent stress is negatively correlated, and exercise positively correlated to LTP induction, we examined whether exercise could mitigate the negative consequences of stress on LTP when co-occurring with stress. Mice were divided into four groups: sedentary no stress, exercise no stress, exercise with stress, and sedentary with stress. Field electrophysiology performed on brain slices confirmed that stress alone significantly reduced dorsal CA1 hippocampal LTP and exercise alone increased LTP compared to controls. Exercise with stress mice exhibited LTP that was significantly greater than mice undergoing stress alone but were not different from sedentary no stress mice. An ELISA illustrated increased corticosterone in stressed mice compared to no stress mice. In addition, a radial arm maze was used to examine behavioral changes in memory during 6 weeks of stress and/or exercise. Exercised mice groups made fewer errors in week 2. RT-qPCR was used to examine the mRNA expression of components in the stress and exercise pathways in the four groups. Significant changes in the expression of the following targets were detected: BDNF, TrkB, glucocorticoid, mineralocorticoid, and dopamine 5 receptors. Collectively, exercise can mitigate some of the negative impact stress has on hippocampal function when both occur concurrently. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Desiccation and storage of Lannea microcarpa from Burkina Faso

    OpenAIRE

    Daws, M.I.; Gaméné, C.E.; Sacandé, M.; Pritchard, H.W.; Groot, S.P.C.; Hoekstra, F.

    2004-01-01

    Seeds of Lannea microcarpa collected from Brurkina Faso in 1997 and 1998 were subjected to desiccation and a range of storage conditions.Seeds were able to tolerate desiccation to low moisture contents (ca 5%) with little loss of viability. In addition, it was possible to store seeds at 25 degrees centigrade at reduced moisture contents (approx. 6%), for up to 14 months. However, seeds stored at -20 or 4 degrees centigrade exhibited a reduction in viability within three months of storage. Thi...

  2. T-cell dysregulation caused by chronic antigenic stress: the role of CMV in immunosenescence?

    Science.gov (United States)

    Pawelec, Graham; Gouttefangeas, Cécile

    2006-04-01

    Dysfunctional T-cell immunity contributes to susceptibility to infectious disease in the elderly. A characteristic feature of this "immunosenescence" is the predominance of clonal expansions of CD8 cells and decreased diversity of the T-cell antigen receptor repertoire. Lifelong chronic antigenic stress commonly caused by infection with persistent activating herpes viruses causes the accumulation of anergic, apoptosis-resistant CD8 T cells. These dysfunctional cells are indirectly immunosuppressive by tasking up the "immunological space" as well as directly suppressive via blockade of antigen presenting cells or cytokine secretion. They are associated with an emerging "immunological risk profile" predicting mortality in longitudinal studies of very old people. It is therefore hypothesized that for that majority of elderly people infected with cytomegalovirus (CMV), which seems to act as the dominant chronic stressor, anti-viral strategies would be of benefit in abrogating some of the detrimental clinical manifestations of immunosenescence.

  3. Increased pain sensitivity in accident-related chronic pain patients with comorbid posttraumatic stress

    DEFF Research Database (Denmark)

    Vaegter, Henrik Bjarke; Andersen, Tonny Elmose; Harvold, Mathea

    2018-01-01

    OBJECTIVES: Posttraumatic stress disorder (PTSD) is prevalent in chronic pain, and associated with increased pain, hyperalgesia and psychological distress. This study aimed to investigate anti-nociceptive and pro-nociceptive pain mechanisms, pain intensity, and psychological distress (depression......, anxiety, pain catastrophizing, and fear of movement) in patients with accident-related chronic spinal pain with (N=44) and without (N=64) comorbid PTSD characteristics. METHODS: Cuff algometry was performed on lower legs to assess pressure pain threshold (cPPT), tolerance (cPTT), temporal summation...... of pain (TSP: increase in pain scores to ten repeated stimulations), and conditioning pain modulation (CPM: increase in cPPT during cuff pain conditioning on the contralateral leg). Warmth detection threshold (WDT) and heat pain threshold (HPT) at the hand were also assessed. Clinical pain intensity...

  4. Chronic stress and calcium oxalate stone disease: influence on blood cortisol and urine composition.

    Science.gov (United States)

    Arzoz-Fàbregas, Montserrat; Ibarz-Servio, Luis; Fernández-Castro, Jordi; Valiente-Malmagro, Manuel; Roca-Antonio, Josep; Edo-Izquierdo, Sílvia; Buisan-Rueda, Oscar

    2013-12-01

    To evaluate the influence of chronic stress (CS) on urine composition of calcium oxalate (CaOx) stone patients and controls. This case-control study enrolled 128 patients during a period of 20 months. The cases were CaOx stone formers with a recent stone episode. Controls were matched by sex and age. Dimensions of CS were evaluated in cases and controls by validated self-report questionnaires measuring stressful life events, perceived stress, anxiety, depression, burnout, and satisfaction with life. Blood and urine samples were collected to determine cortisol levels and urinary composition. More relations between CS dimensions and blood and urine parameters were observed in cases than in controls. In cases, the blood cortisol level was related positively with the number of stressful life events (P = .03), intensity of these events (P = .04), and anxiety (P = .04). In addition, urinary magnesium (P = .03) and pyrophosphate (P = .05) levels were positively related with satisfaction with life and burnout, respectively. In contrast, urinary magnesium levels were negatively related with perceived stress (P = .01), anxiety (P = .016), and depression (P = .03). In controls, the number of stressful life events and the intensity of stressful life events was related positively with magnesium (P = .06, P = .02) levels and negatively with blood cortisol levels (P = .03, P = .004). Based on the variation between cases and controls in relations between CS dimensions and biochemical parameters, we hypothesize that CS may trigger a differential biological response in CaOx stone formers and controls, which in turn may promote or protect against CaOx stone formation. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Chronic Stress Contributes to Cognitive Dysfunction and Hippocampal Metabolic Abnormalities in APP/PS1 Mice

    Directory of Open Access Journals (Sweden)

    Bing Han

    2017-03-01

    Full Text Available Background/Aims: Stress response is determined by the brain, and the brain is a sensitive target for stress. Our previous experiments have confirmed that once the stress response is beyond the tolerable limit of the brain, particularly that of the hippocampus, it will have deleterious effects on hippocampal structure and function; however, the metabolic mechanisms for this are not well understood. Methods: Here, we used morris water maze, elisa and gas chromatography-time of flight/mass spectrometry to observe the changes in cognition, neuropathology and metabolomics in the hippocampus of APP/PS1 mice and wild-type (C57 mice caused by chronic unpredictable mild stress (CUMS, we also further explored the correlation between cognition and metabolomics. Results: We found that 4 weeks of CUMS aggravated cognitive impairment and increased amyloid-β deposition in APP/PS1 mice, but did not affect C57 mice. Under non-stress conditions, compared with C57 mice, there were 8 different metabolites in APP/PS1 mice. However, following CUMS, 3 different metabolites were changed compared with untreated C57 mice. Compared to APP/PS1 mice, there were 7 different metabolites in APP/PS1+CUMS mice. Among these alterations, 3-hydroxybutyric acid, valine, serine, beta-alanine and o-phosphorylethanolamine, which are involved in sphingolipid metabolism, synthesis and degradation of ketone bodies, and amino acid metabolism. Conclusion: The results indicate that APP/PS1 mice are more vulnerable to stress than C57 mice, and the metabolic mechanisms of stress-related cognitive impairment in APP/PS1 mice are related to multiple pathways and networks, including sphingolipid metabolism, synthesis and degradation of ketone bodies, and amino acid metabolism.

  6. Impact of Stressful Life Events on Patients with Chronic Obstructive Pulmonary Disease.

    Science.gov (United States)

    Yu, Tsung; Frei, Anja; Ter Riet, Gerben; Puhan, Milo A

    2018-01-01

    There is a general notion that stressful life events may cause mental and physical health problems. We aimed to describe stressful life events reported by patients with chronic obstructive pulmonary disease (COPD) and to assess their impact on health outcomes and behaviors. Two hundred and sixty-six primary care patients who participated in the ICE COLD ERIC cohort study were asked to document any stressful life events in the past 3 years. We assessed the before-after (the event) changes for symptoms of depression and anxiety, health status, dyspnea-related quality of life, exacerbations, cigarette use, and physical activity. We used linear regression analysis to estimate the crude and adjusted magnitude of the before-after changes. About 41% (110/266) of patients reported the experience of any stressful life events and "death of relatives/important persons" was most common (31%). After accounting for age, sex, living status, lung function, and anxiety/depression status at baseline, experiencing any stressful life events was associated with a 0.9-point increase on the depression scale (95% CI 0.3 to 1.4), a 0.8-point increase on the anxiety scale (95% CI 0.3 to 1.3), and a 0.8-point decrease in the physical activity score (95% CI -1.6 to 0). Experiencing stressful life events was associated with a small to moderate increase in symptoms of depression and anxiety in COPD, but no discernable effect was found for other physical outcomes. However, confirmation of these results in other COPD cohorts and identification of patients particularly vulnerable to stressful life events are needed. © 2017 S. Karger AG, Basel.

  7. Behavioral and neuroendocrine effects of the exposure to chronic restraint or variable stress in early adolescent rats.

    Science.gov (United States)

    Cruz, Fábio C; Marin, Marcelo T; Leão, Rodrigo M; Planeta, Cleopatra S

    2012-02-01

    Stress events during adolescence may contribute to the expression or exacerbation of physical and behavioral disorders. However, little attention has been given to the physiological and behavioral changes promoted by stress during this period of ontogeny. In the present study we investigated, in adolescent male rats, the effects of repeated exposure to restraint or variable stress on: (a) locomotor activity and corticosterone levels after exposure to a novel environment; (b) corticosterone levels in response to the exposure to restraint stress; and (c) changes in body, thymus and adrenal weights. The results demonstrated that repeated exposure to restraint or variable stress reduced the locomotor response, but did not affect corticosterone secretion, in response to a novel environment. Moreover, both chronic stress procedures did not change corticosterone secretion in response to acute restraint stress. Furthermore, our results showed that repeated restraint, but not variable stress, produced a decrease in body weight along the stress exposure. Finally, we observed that the exposure to variable stress reduced the thymus relative weight. Taken together our results suggest that behavioral and physiological changes induced by exposure to chronic stress during adolescence depend on the stress regimen. Copyright © 2011 ISDN. Published by Elsevier Ltd. All rights reserved.

  8. Effect of chronic forced swimming stress on whole brain radiation induced cognitive dysfunction and related mechanism

    International Nuclear Information System (INIS)

    Zhang Yuan; Sun Rui; Zhu Yaqun; Zhang Liyuan; Ji Jianfeng; Li Kun; Tian Ye

    2014-01-01

    Objective: To explore whether chronic forced swimming stress could improve whole brain radiation induced cognitive dysfunction and possible mechanism. Methods: Thirty-nine one month old male Sprague-Dawley rats were randomized into sham control group(C), swimming group(C-S), radiation group(R), and radiation plus swimming group(R-S). Radiation groups were given a single dose of 20 Gy on whole-brain. Rats in the swimming groups were trained with swimming of 15 min/d, 5 d/w. Rat behavior was performed 3 months after radiation in an order of free activity in an open field and the Morris water maze test including the place navigation and spatial probe tests. Then, the protein expressions of BDNF, P-ERK, T-ERK, P-CREB and T-CREB in the rat hippocampus tissue were assayed by Western blot. Results: On the day 2, in the place navigation test of Morris water maze, the latency of swimming group was significantly shorter than that of sham group, the latency of sham group was significantly shorter than that of radiation group, and the latency of radiation swimming group was significantly shorter than that of radiation group(P < 0.05). In the open field test, the latencies of the place navigation and spatial probe tests of Morris water maze had no significant difference among four groups (P > 0.05). Western blot assay showed that the expressions of BDNF and its downstream signals including P-ERK and P-CREB were markedly reduced by radiation (P < 0.05), but this reduction was attenuated by the chronic forced swimming stress. Conclusion: The chronic forced swimming stress could improve whole brain radiation induced cognitive dysfunction by up-regulating the expressions of BDNF and its downstream signal molecules of P-ERK and P-CREB in hippocampus. (authors)

  9. Chronic psychological stress seems associated with elements of the metabolic syndrome in patients with ischaemic heart disease.

    Science.gov (United States)

    Bergmann, Natasha; Ballegaard, Søren; Krogh, Jesper; Bech, Per; Hjalmarson, Åke; Gyntelberg, Finn; Faber, Jens

    2017-11-01

    Chronic psychological stress, the metabolic syndrome (MS) and ischaemic heart disease (IHD) seem closely connected. In this study, we evaluate the association between chronic stress and elements of MS in patients with stable IHD. Cross-sectional cohort study. Three hundred and fifty patients with stable IHD were included. Chronic stress was evaluated by the two questionnaires, Major Depression Inventory (MDI) and the psychological wellbeing index WHO-5, as well as by Pressure Pain Sensitivity (PPS), a physiological measure of hyperalgesia at the sternum known to be associated to elements of the chronic stress syndrome. Elements of MS were evaluated by dual-energy X-ray absorptiometry, body weight, HOMA-IR and blood lipids. Depressive symptoms were associated with a high percentage of body fat (β = 0.179, p = .001), and high level of triglycerides (β = 0.150, p = .007). Low psychological wellbeing was associated with a high percentage of body fat (β = -0.165, p = .002) and low level of HDL cholesterol (β = 0.128, p = .024). Chronic stress measured by PPS was associated with a high percentage body fat (β = 0.327, p stress seem associated with a high percentage of body fat and adverse blood lipids independent of several lifestyle factors.

  10. TGF-β1/Smad2/3/Foxp3 signaling is required for chronic stress-induced immune suppression.

    Science.gov (United States)

    Zhang, Haiju; Caudle, Yi; Wheeler, Clay; Zhou, Yu; Stuart, Charles; Yao, Baozhen; Yin, Deling

    2018-01-15

    Depending on the duration and severity, psychological tension and physical stress can enhance or suppress the immune system in both humans and animals. Although it has been established that chronic stress exerts a significant suppressive effect on immune function, the mechanisms by which affects immune responses remain elusive. By employing an in vivo murine system, we revealed that TGF-β1/Smad2/3/Foxp3 axis was remarkably activated following chronic stress. Furthermore, TLR9 and p38 MAPK played a critical role in the activation of TGF-β1/Smad2/3/Foxp3 signaling cascade. Moreover, inhibition of TGF-β1/Smad2/3/Foxp3 or p38 significantly attenuated chronic stress-induced lymphocyte apoptosis and apoptosis-related proteins, as well as the differentiation of T regulatory cells in spleen. Interestingly, disequilibrium of pro-inflammatory and anti-inflammatory cytokines balance caused by chronic stress was also rescued by blocking TGF-β1/Smad2/3/Foxp3 axis. These findings yield insight into a novel mechanism by which chronic stress modulates immune functions and identifies new targets for the development of novel anti-immune suppressant medications. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Exposure to chronic mild stress prevents kappa opioid-mediated reinstatement of cocaine and nicotine place preference

    Directory of Open Access Journals (Sweden)

    Ream eAl-Hasani

    2013-08-01

    Full Text Available Stress increases the risk of drug abuse, causes relapse to drug seeking, and potentiates the rewarding properties of both nicotine and cocaine. Understanding the mechanisms by which stress regulates the rewarding properties of drugs of abuse provides valuable insight into potential treatments for drug abuse. Prior reports have demonstrated that stress causes dynorphin release, activating kappa-opioid receptors (KOR in monoamine circuits resulting in both potentiation and reinstatement of cocaine and nicotine conditioned place preference. Here we report that kappa-opioid dependent reinstatement of cocaine and nicotine place preference is reduced when the mice are exposed to a randomized chronic mild stress regime prior to training in a conditioned place preference-reinstatement paradigm. The chronic mild stress schedule involves seven different stressors (removal of nesting for 24hr, 5min forced swim stress at 15°C, 8hr food and water deprivation, damp bedding overnight, white noise, cage tilt and disrupted home cage lighting rotated over a three-week period. This response is KOR-selective, because chronic mild stress does not protect against cocaine or nicotine drug-primed reinstatement. This protection from reinstatement is also observed following sub-chronic social defeat stress, where each mouse is placed in an aggressor mouse home cage for a period of 20 min over five days. In contrast, a single acute stressor resulted in a potentiation of KOR-induced reinstatement, similarly to previously reported. Prior studies have shown that stress alters sensitivity to opioids and prior stress can influence the pharmacodynamics of the opioid receptor system. Together, these findings suggest that exposure to different forms of stress may cause a dysregulation of kappa opioid circuitry and that changes resulting from mild stress can have protective and adaptive effects against drug relapse.

  12. A rapid transcriptome response is associated with desiccation resistance in aerially-exposed killifish embryos.

    Directory of Open Access Journals (Sweden)

    Angèle Tingaud-Sequeira

    Full Text Available Delayed hatching is a form of dormancy evolved in some amphibian and fish embryos to cope with environmental conditions transiently hostile to the survival of hatchlings or larvae. While diapause and cryptobiosis have been extensively studied in several animals, very little is known concerning the molecular mechanisms involved in the sensing and response of fish embryos to environmental cues. Embryos of the euryhaline killifish Fundulus heteroclitus advance dvelopment when exposed to air but hatching is suspended until flooding with seawater. Here, we investigated how transcriptome regulation underpins this adaptive response by examining changes in gene expression profiles of aerially incubated killifish embryos at ∼100% relative humidity, compared to embryos continuously flooded in water. The results confirm that mid-gastrula embryos are able to stimulate development in response to aerial incubation, which is accompanied by the differential expression of at least 806 distinct genes during a 24 h period. Most of these genes (∼70% appear to be differentially expressed within 3 h of aerial exposure, suggesting a broad and rapid transcriptomic response. This response seems to include an early sensing phase, which overlaps with a tissue remodeling and activation of embryonic development phase involving many regulatory and metabolic pathways. Interestingly, we found fast (0.5-1 h transcriptional differences in representatives of classical "stress" proteins, such as some molecular chaperones, members of signalling pathways typically involved in the transduction of sensor signals to stress response genes, and oxidative stress-related proteins, similar to that described in other animals undergoing dormancy, diapause or desiccation. To our knowledge, these data represent the first transcriptional profiling of molecular processes associated with desiccation resistance during delayed hatching in non-mammalian vertebrates. The exceptional transcriptomic

  13. Proteomic Analysis of Liver Proteins in a Rat Model of Chronic Restraint Stress-Induced Depression

    Directory of Open Access Journals (Sweden)

    Cong Li

    2017-01-01

    Full Text Available Depression is a global mental disorder disease and greatly threatened human health and stress is considered to be one of the important factors that lead to depression. In this study, we used newly developed iTRAQ labeling and high performance liquid chromatography (HPLC and mass spectrum united analysis technology obtained the 2176 accurate proteins. Successively, we used the GO analysis and IPA software to analyze the 98 differentially expressed proteins of liver in depression rats due to chronic restraint stress, showing a map of proteomics analysis of liver proteins from the aspects of related functions, disease and function analysis, canonical pathway analysis, and associated network. This study provide important information for comprehensively understanding the mechanisms of dysfunction or injury in the liver in depression.

  14. Chronic Stress Improves NO- and Ca2+ Flux-Dependent Vascular Function: A Pharmacological Study.

    Science.gov (United States)

    Bruder-Nascimento, Thiago; Campos, Dijon Henrique Salome

    2015-01-23

    Background: Stress is associated with cardiovascular diseases. Objective: This study aimed at assessing whether chronic stress induces vascular alterations, and whether these modulations are nitric oxide (NO) and Ca2+ dependent. Methods: Wistar rats, 30 days of age, were separated into 2 groups: control (C) and Stress (St). Chronic stress consisted of immobilization for 1 hour/day, 5 days/week, 15 weeks. Systolic blood pressure was assessed. Vascular studies on aortic rings were performed. Concentration-effect curves were built for noradrenaline, in the presence of L-NAME or prazosin, acetylcholine, sodium nitroprusside and KCl. In addition, Ca2+ flux was also evaluated. Results: Chronic stress induced hypertension, decreased the vascular response to KCl and to noradrenaline, and increased the vascular response to acetylcholine. L-NAME blunted the difference observed in noradrenaline curves. Furthermore, contractile response to Ca2+ was decreased in the aorta of stressed rats. Conclusion: Our data suggest that the vascular response to chronic stress is an adaptation to its deleterious effects, such as hypertension. In addition, this adaptation is NO- and Ca2+-dependent. These data help to clarify the contribution of stress to cardiovascular abnormalities. However, further studies are necessary to better elucidate the mechanisms involved in the cardiovascular dysfunction associated with stressors. (Arq Bras Cardiol. 2014; [online].ahead print, PP.0-0)Fundamento: Estresse está associado com complicações cardiovasculares. Objetivos: O objetivo do presente estudo foi avaliar se o estresse crônico induz alterações vasculares, e se essas alterações são dependentes de óxido nítrico (NO) e Ca2+. Métodos: Ratos machos Wistar com 30 dias de idade foram separados em 2 grupos: controle (C) e Estresse (St). Utilizou-se estresse crônico de imobilização por 1 hora/dia, 5 dias/semana, 15 semanas. Pressão arterial sistólica foi avaliada. A função vascular foi

  15. Tension Band Plating for Chronic Anterior Tibial Stress Fractures in High-Performance Athletes.

    Science.gov (United States)

    Zbeda, Robert M; Sculco, Peter K; Urch, Ekaterina Y; Lazaro, Lionel E; Borens, Olivier; Williams, Riley J; Lorich, Dean G; Wellman, David S; Helfet, David L

    2015-07-01

    Anterior tibial stress fractures are associated with high rates of delayed union and nonunion, which can be particularly devastating to a professional athlete who requires rapid return to competition. Current surgical treatment strategies include intramedullary nailing, which has satisfactory rates of fracture union but an associated risk of anterior knee pain. Anterior tension band plating is a biomechanically sound alternative treatment for these fractures. Tension band plating of chronic anterior tibial stress fractures leads to rapid healing and return to physical activity and avoids the anterior knee pain associated with intramedullary nailing. Case series; Level of evidence, 4. Between 2001 and 2013, there were 13 chronic anterior tibial stress fractures in 12 professional or collegiate athletes who underwent tension band plating after failing nonoperative management. Patient charts were retrospectively reviewed for demographics, injury history, and surgical details. Radiographs were used to assess time to osseous union. Follow-up notes and phone interviews were used to determine follow-up time, return to training time, and whether the patient was able to return to competition. Cases included 13 stress fractures in 12 patients (9 females, 3 males). Five patients were track-and-field athletes, 4 patients played basketball, 2 patients played volleyball, and 1 was a ballet dancer. Five patients were Division I collegiate athletes and 7 were professional or Olympic athletes. Average age at time of surgery was 23.6 years (range, 20-32 years). Osseous union occurred on average at 9.6 weeks (range, 5.3-16.9 weeks) after surgery. Patients returned to training on average at 11.1 weeks (range, 5.7-20 weeks). Ninety-two percent (12/13) eventually returned to preinjury competition levels. Thirty-eight percent (5/13) underwent removal of hardware for plate prominence. There was no incidence of infection or nonunion. Anterior tension band plating for chronic tibial stress

  16. Quality of life among pediatric patients with cancer: Contributions of time since diagnosis and parental chronic stress.

    Science.gov (United States)

    Hamner, Taralee; Latzman, Robert D; Latzman, Natasha E; Elkin, T David; Majumdar, Suvankar

    2015-07-01

    Pediatric cancer is associated with a host of negative psychosocial consequences; however, outcomes vary extensively suggesting a need to better understand this variation. Empirical research suggests a positive association between time since diagnosis (TSD) and Quality of Life (QoL). In addition to TSD, family stressors have been found to be particularly important in predicting QoL among children. The current study examined parental chronic stress beyond TSD in explanation of QoL functioning among a sample of pediatric patients with cancer. Participants included 43 pediatric patients aged 5-18 years (M(age) = 10.2 ± 3.6) who were undergoing oncological treatment. Parents reported on TSD, child's QoL, and their own chronic stress. TSD was associated with greater physical functioning (r = 0.30, P stress was associated with poorer emotional (r = -0.54, P stress contributed incrementally beyond TSD in the explanation of physical (β = -0.37, t = -2.58, P stress is associated with reduced levels of emotional, physical, and social functioning among pediatric patients. Future research is needed to further investigate the process by which chronic stress within the family interferes with adaptive coping among pediatric patients. In addition, clinical services may benefit from increased consideration of family factors, such as parental chronic stress, during oncological treatment. © 2015 Wiley Periodicals, Inc.

  17. Hypericum perforatum treatment: effect on behaviour and neurogenesis in a chronic stress model in mice

    Directory of Open Access Journals (Sweden)

    Cuzzocrea Salvatore

    2011-01-01

    Full Text Available Abstract Background Extracts of Hypericum perforatum (St. John's wort have been traditionally recommended for a wide range of medical conditions, in particular mild-to-moderate depression. The present study was designed to investigate the effect of Hypericum perforatum treatment in a mouse model of anxiety/depressive-like behavior, induced by chronic corticosterone administration. Methods CD1 mice were submitted to 7 weeks corticosterone administration and then behavioral tests as Open Field (OF, Novelty-Suppressed Feeding (NSF, Forced Swim Test (FST were performed. Cell proliferation in hippocampal dentate gyrus (DG was investigated by both 5-bromo-2'-deoxyuridine (BrdU and doublecortin (DCX immunohistochemistry techniques and stereological procedure was used to quantify labeled cells. Golgi-impregnation method was used to evaluate changes in dendritic spines in DG. Hypericum perforatum (30 mg/Kg has been administered for 3 weeks and then neural development in the adult hippocampus and behavioral changes have been examined. Results The anxiety/depressive-like state due to chronic corticosterone treatment was reversed by exogenous administration of Hypericum perforatum; the proliferation of progenitor cells in mice hippocampus was significantly reduced under chronic corticosterone treatment, whereas a long term treatment with Hypericum perforatum prevented the corticosterone-induced decrease in hippocampal cell proliferation. Corticosterone-treated mice exhibited a reduced spine density that was ameliorated by Hypericum perforatum administration. Conclusion These results provide evidence of morphological adaptations occurring in mature hippocampal neurons that might underlie resilient responses to chronic stress and contribute to the therapeutic effects of chronic Hypericum perforatum treatment.

  18. What worries parents of a child with Autism? Evidence from a biomarker for chronic stress.

    Science.gov (United States)

    Bitsika, Vicki; Sharpley, Christopher F; Andronicos, Nicholas M; Agnew, Linda L

    2017-03-01

    Previous studies have reported correlations between various aspects of the behaviour and symptomatology of children with Autism Spectrum Disorder (ASD) and their parents' self-reports of stress via standardised scales. To extend that literature, a physiological index of parental chronic stress was used instead of their self-reports-dysregulation of the Diurnal Rhythm (DR) of the Hypothalamic-Pituitary-Adrenal (HPA) axis. A sample of 149 parents of a child with ASD provided salivary cortisol at the predicted time of daily maximum cortisol concentration and at a time of daily lower concentration. Adherence to the predicted DR was assessed via a dichotomous (present/not-present) as well as a continuous measure, and MANOVA and linear regression were used to detect significant associations between ASD-related variables in their children and parents' DR. Identified only a single significant correlate of DR dysregulation in both statistical procedures-Self-Injurious Behaviour (SIB) exhibited by their child and observed by the parents. These findings extend previous data using self-report indices of parental stress and should be included in parent-support settings to alert parents to the long-term health effects of the stress they experience in regard to their child's SIB. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Individual-based analysis of hair corticosterone reveals factors influencing chronic stress in the American pika.

    Science.gov (United States)

    Waterhouse, Matthew D; Sjodin, Bryson; Ray, Chris; Erb, Liesl; Wilkening, Jennifer; Russello, Michael A

    2017-06-01

    . Interestingly, our data suggest evidence for cold stress likely induced during the summer molting period. This technique should provide a useful tool to researchers wishing to assess chronic stress in climate-sensitive mammals.

  20. Performance comparison between a solar driven rotary desiccant cooling system and conventional vapor compression system (performance study of desiccant cooling)

    International Nuclear Information System (INIS)

    Ge, T.S.; Ziegler, F.; Wang, R.Z.; Wang, H.

    2010-01-01

    Solar driven rotary desiccant cooling systems have been widely recognized as alternatives to conventional vapor compression systems for their merits of energy-saving and being eco-friendly. In the previous paper, the basic performance features of desiccant wheel have been discussed. In this paper, a solar driven two-stage rotary desiccant cooling system and a vapor compression system are simulated to provide cooling for one floor in a commercial office building in two cities with different climates: Berlin and Shanghai. The model developed in the previous paper is adopted to predict the performance of the desiccant wheel. The objectives of this paper are to evaluate and compare the thermodynamic and economic performance of the two systems and to obtain useful data for practical application. Results show that the desiccant cooling system is able to meet the cooling demand and provide comfortable supply air in both of the two regions. The required regeneration temperatures are 55 deg. C in Berlin and 85 deg. C in Shanghai. As compared to the vapor compression system, the desiccant cooling system has better supply air quality and consumes less electricity. The results of the economic analysis demonstrate that the dynamic investment payback periods are 4.7 years in Berlin and 7.2 years in Shanghai.

  1. Interactive effects of chronic stress and a high-sucrose diet on nonalcoholic fatty liver in young adult male rats.

    Science.gov (United States)

    Corona-Pérez, Adriana; Díaz-Muñoz, Mauricio; Cuevas-Romero, Estela; Luna-Moreno, Dalia; Valente-Godínez, Héctor; Vázquez-Martínez, Olivia; Martínez-Gómez, Margarita; Rodríguez-Antolín, Jorge; Nicolás-Toledo, Leticia

    2017-11-01

    Glucocorticoids have been implicated in nonalcoholic fatty liver diseases (NAFLD). The influence of a palatable diet on the response to stress is controversial. This study explored whether a high-sucrose diet could protect from hepatic steatosis induced by chronic restraint stress in young adult rats. Male Wistar rats aged 21 days were allocated into four groups (n = 6-8 per group): control, chronic restraint stress, 30% sucrose diet, and 30% sucrose diet plus chronic restraint stress. After being exposed to either tap water or sucrose solution during eight weeks, half of the rats belonging to each group were subject or not to repeated restraint stress (1 h per day, 5 days per week) during four weeks. Triacylglycerol (TAG), oxidative stress, activity of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1), infiltration of immune cells, and glycogen amount in the liver were quantified. Serum concentrations of corticosterone and testosterone were also measured. The stressed group showed normal serum concentrations of corticosterone and did not have hepatic steatosis. However, this group showed increased glycogen, inflammation, mild fibrosis, oxidative stress, and a high activity of 11β-HSD-1 in the liver. The group exposed to the high-sucrose diet had lower concentrations of corticosterone, hepatic steatosis and moderate fibrosis. The group subject to high-sucrose diet plus chronic restraint stress showed low concentrations of corticosterone, hepatic steatosis, oxidative stress, and high concentrations of testosterone. Thus, restraint stress and a high-sucrose diet each generate different components of nonalcoholic fatty liver in young adult rats. The combination of both the factors could promote a faster development of NAFLD.

  2. Reduced tonic inhibition in the dentate gyrus contributes to chronic stress-induced impairments in learning and memory.

    Science.gov (United States)

    Lee, Vallent; MacKenzie, Georgina; Hooper, Andrew; Maguire, Jamie

    2016-10-01

    It is well established that stress impacts the underlying processes of learning and memory. The effects of stress on memory are thought to involve, at least in part, effects on the hippocampus, which is particularly vulnerable to stress. Chronic stress induces hippocampal alterations, including but not limited to dendritic atrophy and decreased neurogenesis, which are thought to contribute to chronic stress-induced hippocampal dysfunction and deficits in learning and memory. Changes in synaptic transmission, including changes in GABAergic inhibition, have been documented following chronic stress. Recently, our laboratory demonstrated shifts in EGABA in CA1 pyramidal neurons following chronic stress, compromising GABAergic transmission and increasing excitability of these neurons. Interestingly, here we demonstrate that these alterations are unique to CA1 pyramidal neurons, since we do not observe shifts in EGABA following chronic stress in dentate gyrus granule cells. Following chronic stress, there is a decrease in the expression of the GABAA receptor (GABAA R) δ subunit and tonic GABAergic inhibition in dentate gyrus granule cells, whereas there is an increase in the phasic component of GABAergic inhibition, evident by an increase in the peak a