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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. 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...... human pathogens, encode mechanisms to survive and withstand these stresses. This review provides an overview of the mechanisms employed by Salmonella spp., Shiga toxin producing E. coli, Cronobacter spp., Listeria monocytogenes and Campylobacter spp. to tolerate osmotic and desiccation stresses...... and identifies gaps in knowledge which need to be addressed to ensure the safety of low water activity and desiccated food products....

  3. A comparative study between Solenopsis invicta and Solenopsis richteri on tolerance to heat and desiccation stresses.

    Directory of Open Access Journals (Sweden)

    Jian Chen

    Full Text Available Solenopsis invicta and Solenopsis richteri are two very closely related invasive ant species; however, S. invicta is a much more successful invader. Physiological tolerance to abiotic stress has been hypothesized to be important to the success of an invasive species. In this study, we tested the hypothesis that S. invicta is more tolerant to heat and desiccation stress than S. richteri. The data strongly support our hypothesis. S. invicta was found to be significantly less vulnerable than S. richteri to both heat and desiccation stress. Despite S. richteri having significantly higher body water content, S. invicta was less sensitive to desiccation stress due to its significantly lower water loss rate (higher desiccation resistance. After the cuticular lipid was removed, S. invicta still had a significantly lower water loss rate than S. richteri, indicating that cuticular lipids were not the only factors accounting for difference in the desiccation resistance between these two species. Since multiple biological and/or ecological traits can contribute to the invasion success of a particular species, whether the observed difference in tolerance to heat and desiccation stresses is indeed associated with the variation in invasion success between these two species can only be confirmed by further extensive comparative study.

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

    Science.gov (United States)

    2014-01-01

    Background 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. Results 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 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. Conclusions 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 in evaluating M. anisopliae efficacy under desiccation stress. PMID:24383424

  5. 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 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 in evaluating M. anisopliae efficacy under desiccation stress.

  6. Cloning and baculovirus expression of a desiccation stress gene from the beetle, Tenebrio molitor.

    Science.gov (United States)

    Graham, L A; Bendena, W G; Walker, V K

    1996-02-01

    The cDNA sequence encoding a novel desiccation stress protein (dsp28) found in the hemolymph of the common yellow mealworm beetle, Tenebrio molitor, has been determined. The sequence encodes a 225 amino acid protein containing a 20 amino acid signal peptide. Dsp28 shows no significant similarity to any known nucleic acid or protein sequence. Levels of dsp28 mRNA were found to increase approx 5-fold following desiccation. Dsp28 cDNA has been cloned into a baculovirus expression vector and the expressed protein was compared to native dsp28. Both dsp28 expressed by recombinant baculovirus and native dsp28 are glycosylated and N-terminally processed. Although dsp28 is induced by cold in addition to desiccation stress, it does not contribute to the freezing point depression (thermal hysteresis) observed in Tenebrio hemolymph.

  7. Desiccation: An environmental and food industry stress that bacteria commonly face.

    Science.gov (United States)

    Esbelin, Julia; Santos, Tiago; Hébraud, Michel

    2018-02-01

    Water is essential for all living organisms, for animals as well as for plants and micro-organisms. For these latter, the presence of water or a humid environment with a high air relative humidity (RH) is necessary for their survival and growth. Thus, variations in the availability of water or in the air relative humidity constitute widespread environmental stresses which challenge microorganisms, and especially bacteria. Indeed, in their direct environment, bacteria are often faced with conditions that remove cell-bound water through air-drying of the atmosphere. Bacterial cells are subject to daily or seasonal environmental variations, sometimes going through periods of severe desiccation. This is also the case in the food industry, where air dehumidification treatments are applied after the daily cleaning-disinfection procedures. In plants producing low-water activity products, it is also usual to significantly reduce or eliminate water usage. Periodic desiccation exposure affects bacteria viability and so they require strategies to persist. Negative effects of desiccation are wide ranging and include direct cellular damage but also changes in the biochemical and biophysical properties of cells for which planktonic cells are more exposed than cells in biofilm. Understanding the mechanisms of desiccation adaptation and tolerance has a biological and biotechnological interest. This review gives an overview of the factors influencing desiccation tolerance and the biological mechanisms involved in this stress response. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. 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

  9. 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

  10. Two Hymenophyllaceae species from contrasting natural environments exhibit a homoiochlorophyllous strategy in response to desiccation stress.

    Science.gov (United States)

    Flores-Bavestrello, Alejandra; Król, Marianna; Ivanov, Alexander G; Hüner, Norman P A; García-Plazaola, José Ignacio; Corcuera, Luis J; Bravo, León A

    2016-02-01

    Hymenophyllaceae is a desiccation tolerant family of Pteridophytes which are poikilohydric epiphytes. Their fronds are composed by a single layer of cells and lack true mesophyll cells and stomata. Although they are associated with humid and shady environments, their vertical distribution varies along the trunk of the host plant with some species inhabiting the drier sides with a higher irradiance. The aim of this work was to compare the structure and function of the photosynthetic apparatus during desiccation and rehydration in two species, Hymenophyllum dentatum and Hymenoglossum cruentum, isolated from a contrasting vertical distribution along the trunk of their hosts. Both species were subjected to desiccation and rehydration kinetics to analyze frond phenotypic plasticity, as well as the structure, composition and function of the photosynthetic apparatus. Minimal differences in photosynthetic pigments were observed upon dehydration. Measurements of ϕPSII (effective quantum yield of PSII), ϕNPQ (quantum yield of the regulated energy dissipation of PSII), ϕNO (quantum yield of non-regulated energy dissipation of PSII), and TL (thermoluminescence) indicate that both species convert a functional photochemical apparatus into a structure which exhibits maximum quenching capacity in the dehydrated state with minimal changes in photosynthetic pigments and polypeptide compositions. This dehydration-induced conversion in the photosynthetic apparatus is completely reversible upon rehydration. We conclude that H. dentatum and H. cruentum are homoiochlorophyllous with respect to desiccation stress and exhibited no correlation between inherent desiccation tolerance and the vertical distribution along the host tree trunk. Copyright © 2015 Elsevier GmbH. All rights reserved.

  11. 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

  12. 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

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

    Science.gov (United States)

    Fraser, Clarissa M L; Seebacher, Frank; Lathlean, Justin; Coleman, Ross A

    2016-01-01

    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.

  14. Physiological Response of Wheat to Chemical Desiccants Used to Simulate Post-Anthesis Drought Stress

    Directory of Open Access Journals (Sweden)

    Nasrein Mohamed Kamal

    2018-04-01

    Full Text Available Post-anthesis drought stress is one of the main constraints on the production of wheat (Triticum aestivum L.. Because field screening for post-anthesis drought tolerance is difficult, effective and validated methods to simulate drought in order to identify sources of tolerance can facilitate screening of breeding materials. Chemical desiccants are widely used to simulate post-anthesis drought stress. We aimed to identify physiological traits that respond to desiccants as they do to drought. We examined the responses of ‘Norin 61’ to six treatments in a greenhouse: irrigated control, drought after anthesis, and 2% or 4% potassium chlorate (KClO3 at anthesis (A or grain filling (GF. We measured δ13C in leaves, aboveground fresh biomass, stomatal conductance, chlorophyll content, harvest index, and grain yield. Both 2% and 4% KClO3 at both A and GF simulated the effect of drought stress. Selection of drought-tolerant genotypes can be aided by chlorophyll content and δ13C measurement of leaves when 2% or 4% KClO3 is used to simulate drought.

  15. 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.

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

    Science.gov (United States)

    Fraser, Clarissa M. L.; Seebacher, Frank; Lathlean, Justin; Coleman, Ross A.

    2016-01-01

    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. PMID:26959815

  17. 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

  18. 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

    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......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...

  19. 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.

  20. Selection for increased desiccation resistance in Drosophila melanogaster: Additive genetic control and correlated responses for other stresses

    International Nuclear Information System (INIS)

    Hoffmann, A.A.; Parsons, P.A.

    1989-01-01

    Previously we found that Drosophila melanogaster lines selected for increased desiccation resistance have lowered metabolic rate and behavioral activity levels, and show correlated responses for resistance to starvation and a toxic ethanol level. These results were consistent with a prediction that increased resistance to many environmental stresses may be genetically correlated because of a reduction in metabolic energy expenditure. Here we present experiments on the genetic basis of the selection response and extend the study of correlated responses to other stresses. The response to selection was not sex-specific and involved X-linked and autosomal genes acting additively. Activity differences contributed little to differences in desiccation resistance between selected and control lines. Selected lines had lower metabolic rates than controls in darkness when activity was inhibited. Adults from selected lines showed increased resistance to a heat shock, 60 Co-gamma-radiation, and acute ethanol and acetic acid stress. The desiccation, ethanol and starvation resistance of isofemale lines set up from the F2s of a cross between one of the selected and one of the control lines were correlated. Selected and control lines did not differ in ether-extractable lipid content or in resistance to acetone, ether or a cold shock

  1. 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

  2. Contrasting strategies used by lichen microalgae to cope with desiccation-rehydration stress revealed by metabolite profiling and cell wall analysis.

    Science.gov (United States)

    Centeno, Danilo C; Hell, Aline F; Braga, Marcia R; Del Campo, Eva M; Casano, Leonardo M

    2016-05-01

    Most lichens in general, and their phycobionts in particular, are desiccation tolerant, but their mechanisms of desiccation tolerance (DT) remain obscure. The physiological responses and cell wall features of two putatively contrasting lichen-forming microalgae, Trebouxia sp. TR9 (TR9), isolated from Ramalina farinacea (adapted to frequent desiccation-rehydration cycles), and Coccomyxa solorina-saccatae (Csol), obtained from Solorina saccata (growing in usually humid limestone crevices, subjected to seasonal dry periods) was characterized. Microalgal cultures were desiccated under 25%-30% RH and then rehydrated. Under these conditions, RWC and ψw decreased faster and simultaneously during dehydration in Csol, whereas TR9 maintained its ψw until 70% RWC. The metabolic profile indicated that polyols played a key role in DT of both microalgae. However, TR9 constitutively accumulated higher amounts of polyols, whereas Csol induced the polyol synthesis under desiccation-rehydration. Csol also accumulated ascorbic acid, while TR9 synthesized protective raffinose-family oligosaccharides (RFOs) and increased its content of phenolics. Additionally, TR9 exhibited thicker and qualitatively different cell wall and extracellular polymeric layer compared with Csol, indicating higher water retention capability. The findings were consistent with the notion that lichen microalgae would have evolved distinct strategies to cope with desiccation-rehydration stress in correspondence with the water regime of their respective habitats. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Clinical and Molecular Inflammatory Response in Sjögren Syndrome-Associated Dry Eye Patients Under Desiccating Stress.

    Science.gov (United States)

    López-Miguel, Alberto; Tesón, Marisa; Martín-Montañez, Vicente; Enríquez-de-Salamanca, Amalia; Stern, Michael E; González-García, María J; Calonge, Margarita

    2016-01-01

    To evaluate the response of the lacrimal function unit in Sjögren syndrome (SS)-associated dry eye patients exposed to 2 simulated daily life environmental conditions. Prospective crossover pilot study. Fourteen female SS dry eye patients were exposed for 2 hours to a controlled normal condition (23 C, 45% relative humidity, and air flow 0.10 m/s) and a controlled adverse condition that simulates desiccating stress (23 C, 5% relative humidity, and air flow 0.10 m/s). The following dry eye tests were performed before and after the exposure: tear osmolarity, phenol red thread test, conjunctival hyperemia, fluorescein tear break-up time, corneal fluorescein staining, conjunctival lissamine green staining, and Schirmer test. Levels of 16 molecules were analyzed in tears by multiplex immunobead analysis. Clinical evaluation showed lacrimal functional unit impairment after the desiccating stress: significantly increased tear osmolarity (315.7 ± 3.0 vs 327.7 ± 5.1 mOsm/L, P = .03), conjunctival hyperemia (1.3 ± 0.1 vs 1.6 ± 0.1, P = .05), and corneal staining in temporal (3.5 ± 0.5 vs 4.7 ± 0.4, P = .01) and nasal (3.6 ± 0.5 vs 4.5 ± 0.5, P = .04) areas. Tear concentrations increased for interleukin-1 receptor antagonist (16 557.1 ± 4047.8 vs 31 895.3 ± 5916.5 pg/mL, P = .01), interleukin-6 (63.8 ± 20.2 vs 111.5 ± 29.6 pg/mL, P = .02), interleukin-8 (2196.1 ± 737.9 vs 3753.2 ± 1106.0 pg/mL, P = .03), and matrix metalloproteinase-9 (101 515.6 ± 37 088.4 vs 145 867.1 ± 41 651.5 pg/mL, P = .03). After the simulated normal condition, only a significant increase in nasal corneal staining (2.9 ± 0.5 vs 3.6 ± 0.5, P = .03) was observed. Even a short exposure to a desiccating environment can produce a significant deterioration of the lacrimal function unit in female SS dry eye patients. The often unnoticed exposure to these conditions during daily life may increase inflammatory activity rapidly, triggering an ocular surface deterioration. Copyright © 2016

  4. Genotypes Associated with Listeria monocytogenes Isolates Displaying Impaired or Enhanced Tolerances to Cold, Salt, Acid, or Desiccation Stress

    Science.gov (United States)

    Hingston, Patricia; Chen, Jessica; Dhillon, Bhavjinder K.; Laing, Chad; Bertelli, Claire; Gannon, Victor; Tasara, Taurai; Allen, Kevin; Brinkman, Fiona S. L.; Truelstrup Hansen, Lisbeth; Wang, Siyun

    2017-01-01

    The human pathogen Listeria monocytogenes is a large concern in the food industry where its continuous detection in food products has caused a string of recalls in North America and Europe. Most recognized for its ability to grow in foods during refrigerated storage, L. monocytogenes can also tolerate several other food-related stresses with some strains possessing higher levels of tolerances than others. The objective of this study was to use a combination of phenotypic analyses and whole genome sequencing to elucidate potential relationships between L. monocytogenes genotypes and food-related stress tolerance phenotypes. To accomplish this, 166 L. monocytogenes isolates were sequenced and evaluated for their ability to grow in cold (4°C), salt (6% NaCl, 25°C), and acid (pH 5, 25°C) stress conditions as well as survive desiccation (33% RH, 20°C). The results revealed that the stress tolerance of L. monocytogenes is associated with serotype, clonal complex (CC), full length inlA profiles, and the presence of a plasmid which was identified in 55% of isolates. Isolates with full length inlA exhibited significantly (p monocytogenes sequence types, a new inlA PMSC, and several connections between CCs and the presence/absence or variations of specific genetic elements. A whole genome single-nucleotide-variants phylogeny revealed sporadic distribution of tolerant isolates and closely related sensitive and tolerant isolates, highlighting that minor genetic differences can influence the stress tolerance of L. monocytogenes. Specifically, a number of cold and desiccation sensitive isolates contained PMSCs in σB regulator genes (rsbS, rsbU, rsbV). Collectively, the results suggest that knowing the sequence type of an isolate in addition to screening for the presence of full-length inlA and a plasmid, could help food processors and food agency investigators determine why certain isolates might be persisting in a food processing environment. Additionally, increased

  5. 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

  6. 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.

  7. 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.

  8. Oxidative stress adaptation with acute, chronic, and repeated stress.

    Science.gov (United States)

    Pickering, Andrew M; Vojtovich, Lesya; Tower, John; A Davies, Kelvin J

    2013-02-01

    Oxidative stress adaptation, or hormesis, is an important mechanism by which cells and organisms respond to, and cope with, environmental and physiological shifts in the level of oxidative stress. Most studies of oxidative stress adaption have been limited to adaptation induced by acute stress. In contrast, many if not most environmental and physiological stresses are either repeated or chronic. In this study we find that both cultured mammalian cells and the fruit fly Drosophila melanogaster are capable of adapting to chronic or repeated stress by upregulating protective systems, such as their proteasomal proteolytic capacity to remove oxidized proteins. Repeated stress adaptation resulted in significant extension of adaptive responses. Repeated stresses must occur at sufficiently long intervals, however (12-h or more for MEF cells and 7 days or more for flies), for adaptation to be successful, and the levels of both repeated and chronic stress must be lower than is optimal for adaptation to acute stress. Regrettably, regimens of adaptation to both repeated and chronic stress that were successful for short-term survival in Drosophila nevertheless also caused significant reductions in life span for the flies. Thus, although both repeated and chronic stress can be tolerated, they may result in a shorter life. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. 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.

  10. 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

  11. Molecular mechanisms of desiccation tolerance in the resurrection glacial relic Haberlea rhodopensis

    NARCIS (Netherlands)

    Gechev, Tsanko S.; Benina, Maria; Obata, Toshihiro; Tohge, Takayuki; Sujeeth, Neerakkal; Minkov, Ivan; Hille, Jacques; Temanni, Mohamed-Ramzi; Marriott, Andrew S.; Bergstrom, Ed; Thomas-Oates, Jane; Antonio, Carla; Mueller-Roeber, Bernd; Schippers, Jos H. M.; Fernie, Alisdair R.; Toneva, Valentina

    Haberlea rhodopensis is a resurrection plant with remarkable tolerance to desiccation. Haberlea exposed to drought stress, desiccation, and subsequent rehydration showed no signs of damage or severe oxidative stress compared to untreated control plants. Transcriptome analysis by next-generation

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. Dysfunctional stress responses in chronic pain.

    Science.gov (United States)

    Woda, Alain; Picard, Pascale; Dutheil, Frédéric

    2016-09-01

    Many dysfunctional and chronic pain conditions overlap. This review describes the different modes of chronic deregulation of the adaptive response to stress which may be a common factor for these conditions. Several types of dysfunction can be identified within the hypothalamo-pituitary-adrenal axis: basal hypercortisolism, hyper-reactivity, basal hypocortisolism and hypo-reactivity. Neuroactive steroid synthesis is another component of the adaptive response to stress. Dehydroepiandrosterone (DHEA) and its sulfated form DHEA-S, and progesterone and its derivatives are synthetized in cutaneous, nervous, and adipose cells. They are neuroactive factors that act locally. They may have a role in the localization of the symptoms and their levels can vary both in the central nervous system and in the periphery. Persistent changes in neuroactive steroid levels or precursors can induce localized neurodegeneration. The autonomic nervous system is another component of the stress response. Its dysfunction in chronic stress responses can be expressed by decreased basal parasympathethic activity, increased basal sympathetic activity or sympathetic hyporeactivity to a stressful stimulus. The immune and genetic systems also participate. The helper-T cells Th1 secrete pro-inflammatory cytokines such as IL-1-β, IL-2, IL-6, IL-8, IL-12, IFN-γ, and TNF-α, whereas Th2 secrete anti-inflammatory cytokines: IL-4, IL-10, IGF-10, IL-13. Chronic deregulation of the Th1/Th2 balance can occur in favor of anti- or pro-inflammatory direction, locally or systemically. Individual vulnerability to stress can be due to environmental factors but can also be genetically influenced. Genetic polymorphisms and epigenetics are the main keys to understanding the influence of genetics on the response of individuals to constraints. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Transcriptomic analysis of Salmonella desiccation resistance.

    Science.gov (United States)

    Li, Haiping; Bhaskara, Anuhya; Megalis, Christina; Tortorello, Mary Lou

    2012-12-01

    The survival of Salmonella in low moisture foods and processing environments remains a great challenge for the food industry and public health. To explore the mechanisms of Salmonella desiccation resistance, we studied the transcriptomic responses in Salmonella Tennessee (Tennessee), using Salmonella Typhimurium LT2 (LT2), a strain weakly resistant to desiccation, as a reference strain. In response to 2 h of air-drying at 11% equilibrated relative humidity, approximately one-fourth of the open reading frames (ORFs) in the Tennessee genome and one-fifth in LT2 were differentially expressed (>2-fold). Among all differentially expressed functional groups (>5-fold) in both strains, the expression fold change associated with fatty acid metabolism was the highest, and constituted 51% and 35% of the total expression fold change in Tennessee and LT2, respectively. Tennessee showed greater changes in expression of genes associated with stress response and envelope modification than LT2, while showing lesser changes in protein biosynthesis expression. Expression of flagella genes was significantly more inhibited in stationary phase cells of Tennessee than LT2 both before and after desiccation. The accumulation of the osmolyte trehalose was significantly induced by desiccation in Tennessee, but no increase was detectable in LT2, which is consistent with the expression patterns of the entire trehalose biosynthesis and degradation pathways in both strains. Results from this study present a global view of the dynamic desiccation responses in Salmonella, which will guide future research efforts to control Salmonella in low moisture environments.

  18. Genotypes Associated with Listeria monocytogenes Isolates Displaying Impaired or Enhanced Tolerances to Cold, Salt, Acid, or Desiccation Stress

    DEFF Research Database (Denmark)

    Hingston, Patricia A.; Chen, Jessica; Dhillon, Bhavjinder K

    2017-01-01

    elements. A whole genome single-nucleotide-variants phylogeny revealed sporadic distribution of tolerant isolates and closely related sensitive and tolerant isolates, highlighting that minor genetic differences can influence the stress tolerance of L. monocytogenes. Specifically, a number of cold......The human pathogen Listeria monocytogenes is a large concern in the food industry where its continuous detection in food products has caused a string of recalls in North America and Europe. Most recognized for its ability to grow in foods during refrigerated storage, L. monocytogenes can also...... tolerate several other food-related stresses with some strains possessing higher levels of tolerances than others. The objective of this study was to use a combination of phenotypic analyses and whole genome sequencing to elucidate potential relationships between L. monocytogenes genotypes and food...

  19. Tolerance to environmental desiccation in moss sperm.

    Science.gov (United States)

    Shortlidge, Erin E; Rosenstiel, Todd N; Eppley, Sarah M

    2012-05-01

    • Sexual reproduction in mosses requires that sperm be released freely into the environment before finding and fertilizing a receptive female. After release from the male plant, moss sperm may experience a range of abiotic stresses; however, few data are available examining stress tolerance of moss sperm and whether there is genetic variation for stress tolerance in this important life stage. • Here, we investigated the effects of environmental desiccation and recovery on the sperm cells of three moss species (Bryum argenteum, Campylopus introflexus, and Ceratodon purpureus). • We found that a fraction of sperm cells were tolerant to environmental desiccation for extended periods (d) and that tolerance did not vary among species. We found that this tolerance occurs irrespective of ambient dehydration conditions, and that the addition of sucrose during dry-down improved cell recovery. Although we observed no interspecific variation, significant variation among individuals within species in sperm cell tolerance to environmental desiccation was observed, suggesting selection could potentially act on this basic reproductive trait. • The observation of desiccation-tolerant sperm in multiple moss species has important implications for understanding bryophyte reproduction, suggesting the presence of a significant, uncharacterized complexity in the ecology of moss mating systems. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  20. 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.

  1. Developing sporophytes transition from an inducible to a constitutive ecological strategy of desiccation tolerance in the moss Aloina ambigua: effects of desiccation on fitness.

    Science.gov (United States)

    Stark, Lloyd R; Brinda, John C

    2015-03-01

    Two ecological strategies of desiccation tolerance exist in plants, constitutive and inducible. Because of difficulties in culturing sporophytes, very little is known about desiccation tolerance in this generation and how desiccation affects sexual fitness. Cultured sporophytes and vegetative shoots from a single genotype of the moss Aloina ambigua raised in the laboratory were tested for their strategy of desiccation tolerance by desiccating the shoot-sporophyte complex and vegetative shoots at different intensities, and comparing outcomes with those of undried shoot-sporophyte complexes and vegetative shoots. By using a dehardened clonal line, the effects of field, age and genetic variance among plants were removed. The gametophyte and embryonic sporophyte were found to employ a predominantly inducible strategy of desiccation tolerance, while the post-embryonic sporophyte was found to employ a moderately constitutive strategy of desiccation tolerance. Further, desiccation reduced sporophyte fitness, as measured by sporophyte mass, seta length and capsule size. However, the effects of desiccation on sporophyte fitness were reduced if the stress occurred during embryonic development as opposed to postembryonic desiccation. The effects of desiccation on dehardened sporophytes of a bryophyte are shown for the first time. The transition from one desiccation tolerance strategy to the other in a single structure or generation is shown for only the second time in plants and for the first time in bryophytes. Finding degrees of inducible strategies of desiccation tolerance in different life phases prompts the formulation of a continuum hypothesis of ecological desiccation tolerance in mosses, where desiccation tolerance is not an either/or phenomenon, but varies in degree along a gradient of ecological inducibility. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email

  2. 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…

  3. 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.

  4. 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

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

    OpenAIRE

    Sibille, Kimberly T; Langaee, Taimour; Burkley, Ben; Gong, Yan; Glover, Toni L; King, Chris; Riley, Joseph L; Leeuwenburgh, Christiaan; Staud, Roland; Bradley, Laurence A; Fillingim, Roger B

    2012-01-01

    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...

  6. 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...

  7. The dichotomous effect of chronic stress on obesity

    OpenAIRE

    Razzoli, Maria; Bartolomucci, Alessandro

    2016-01-01

    Obesity and metabolic diseases are linked to chronic stress and low socio-economic status. The mechanistic link between stress and obesity has not been clarified, partly due to the inherent complexity exemplified by the bidirectional effect of stress on eating and body weight. Recent studies focusing on adaptive-thermogenesis and brown adipose tissue (BAT) function support a dichotomous relationship to explain the impact of stress on obesity: stress promotes obesity in the presence of hyperph...

  8. Chronic stress and neural function: accounting for sex and age.

    Science.gov (United States)

    Luine, V N; Beck, K D; Bowman, R E; Frankfurt, M; Maclusky, N J

    2007-10-01

    Cognitive responses to stress follow the temporally dependent pattern originally established by Selye (1) wherein short-term stressors elicit adaptive responses whereas continued stress (chronic) results in maladaptive changes--deleterious effects on physiological systems and impaired cognition. However, this pattern for cognitive effects appears to apply to only half the population (males) and, more specifically, to young, adult males. Females show different cognitive responses to stress. In contrast to impaired cognition in males after chronic stress, female rodents show enhanced performance on the same memory tasks after the same stress. Not only cognition, but anxiety, shows sex-dependent changes following chronic stress--stress is anxiolytic in males and anxiogenic in females. Moreover, behavioral responses to chronic stress are different in developing as well as aging subjects (both sexes) as compared to adults. In aged rats, chronic stress enhances recognition memory in both sexes, does not alter spatial memory, and anxiety effects are opposite to young adults. When pregnant dams are exposed to chronic stress, at adulthood the offspring display yet different consequences of stress on anxiety and cognition, and, in contrast to adulthood when the behavioral effects of stress are reversible, prenatal stress effects appear enduring. Changing levels of estradiol in the sexes over the lifespan appear to contribute to the differences in response to stress. Thus, theories of stress dependent modulations in CNS function--developed solely in male models, focused on peripheral physiological processes and tested in adults--may require revision when applied to a more diverse population (age- and sex-wise) at least in relation to the neural functions of cognition and anxiety. Moreover, these results suggest that other stressors and neural functions should be investigated to determine whether age, sex and gonadal hormones also have an impact.

  9. Chronic and Episodic Stress in Children of Depressed Mothers.

    Science.gov (United States)

    Feurer, Cope; Hammen, Constance L; Gibb, Brandon E

    2016-01-01

    The goal of this study was to examine chronic and episodic stress in children of mothers with and without a history of major depressive disorder (MDD) during the children's lives. Participants were 255 mothers selected according to their history of MDD (present vs. absent during child's life) and their children (age 8-14; 53% girls, 81% Caucasian). Mothers' and children's histories of MDD were assessed using diagnostic interviews, and their depressive symptoms were assessed via self-report measures. Children's levels of chronic and episodic stress were assessed using a semistructured contextual threat interview. Children of mothers with a history of recurrent MDD, compared to single MDD or no depression, experienced more chronic stress within several domains including peers, mother-child relations, and other family member relations as well as greater episodic dependent interpersonal stress. Each of these group differences was maintained after excluding children with a history of MDD themselves and controlling for their current depressive symptoms. However, only the group difference in chronic peer stress was maintained when controlling for mothers' current depression. The results suggest that children exposed to recurrent maternal MDD experience higher levels of both chronic and episodic stress, at least some of which they contribute to themselves (dependent interpersonal stress) and which is at least partially independent of the effects of children's depression. In addition, much of this stress is associated primarily with current depression in the mother, though it appears that chronic peer stress may remain elevated even after the remission of maternal depression.

  10. [Dynamics of hormone secretion during chronic emotional stress].

    Science.gov (United States)

    Amiragova, M G; Kovalev, S V; Svirskaia, R I

    1979-05-01

    Study of spontaneous secretion of corticosteroids and thyroid hormones and the direct hormonal response to stress revealed the pathogenic effect of chronic combined emotional stress upon the hormonal function of adrenal glands. The hippocampus takes part in formation of the emotional tension in response to stress stimulus and of the following hormonal secretion.

  11. 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.

  12. 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

  13. Chronic Pain and Chronic Stress: Two Sides of the Same Coin?

    Science.gov (United States)

    Abdallah, Chadi G; Geha, Paul

    2017-02-01

    Pain and stress share significant conceptual and physiological overlaps. Both phenomena challenge the body's homeostasis and necessitate decision-making to help animals adapt to their environment. In addition, chronic stress and chronic pain share a common behavioral model of failure to extinguish negative memories. Yet, they also have discrepancies such that the final brain endophenotype of posttraumatic stress disorder, depression, and chronic pain appears to be different among the three conditions, and the role of the hypothalamic-pituitary-adrenal axis remains unclear in the physiology of pain. Persistence of either stress or pain is maladaptive and could lead to compromised well-being. In this brief review, we highlight the commonalities and differences between chronic stress and chronic pain, while focusing particularly on the central role of the limbic brain. We assess the current attempts in the field to conceptualize and understand chronic pain, within the context of knowledge gained from the stress literature. The limbic brain-including hippocampus, amygdala, and ventromedial pre-frontal cortex-plays a critical role in learning. These brain areas integrate incoming nociceptive or stress signals with internal state, and generate learning signals necessary for decision-making. Therefore, the physiological and structural remodeling of this learning circuitry is observed in conditions such as chronic pain, depression, and posttraumatic stress disorder, and is also linked to the risk of onset of these conditions.

  14. Public Health Burden of Chronic Stress in a Transforming Society

    Directory of Open Access Journals (Sweden)

    Mária S. Kopp

    2007-12-01

    Full Text Available In this paper chronic stress is proposed as an integrating model that can be applied to the explanation of the suddenly changing patterns of premature mortality rates in transforming societies of Central-Eastern-Europe, especially in Hungary. The temporal factor in existing stress models is often neglected. Chronic stress has been shown to lead to typical pathogenetic results in animal experiments. Literature and the different models in the field of psychology, behavioural sciences, and epidemiology are reviewed in terms of the chronic stress theory. There are several conceptual bridges between psychological alterations and the risks, onset and prognosis of chronic disorders of great epidemiological significance. Depending on the field of research there are several parallel concepts which analyse practically the same phenomena. These are the stress theories in physiology, learned helplessness and control theory in psychology, depression research in psychiatry, the concept of vital exhaustion and the psychosocial risk research in sociology. Because chronic stress results in adverse health effects through biological, social and behavioural pathways, this theory might also havethe best explanatory power to understand the premature male morbidity and mortality crisis in Central and Eastern Europe in the last decades. The special features of premature mortality and morbidity crisis in Hungary might be regarded as an experimental model to understand better the human consequences of chronic stress and those processes where psychology meets physiology.

  15. 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.

  16. Physical activity buffers fatigue only under low chronic stress.

    Science.gov (United States)

    Strahler, Jana; Doerr, Johanna M; Ditzen, Beate; Linnemann, Alexandra; Skoluda, Nadine; Nater, Urs M

    2016-09-01

    Fatigue is one of the most commonly reported complaints in the general population. As physical activity (PA) has been shown to have beneficial effects, we hypothesized that everyday life PA improves fatigue. Thirty-three healthy students (21 women, 22.8 ± 3.3 years, 21.7 ± 2.3 kg/m(2)) completed two ambulatory assessment periods. During five days at the beginning of the semester (control condition) and five days during final examination preparation (examination condition), participants repeatedly reported on general fatigue (awakening, 10 am, 2 pm, 6 pm and 9 pm) by means of an electronic diary, collected saliva samples for the assessment of cortisol and α-amylase immediately after providing information on fatigue and wore a triaxial accelerometer to continuously record PA. Self-perceived chronic stress was assessed as a moderator. Using hierarchical linear modeling, including PA, condition (control vs. examination), sex and chronic stress as predictors, PA level during the 15 min prior to data entry did not predict momentary fatigue level. Furthermore, there was no effect of condition. However, a significant cross-level interaction of perceived chronic stress with PA was observed. In fact, the (negative) relationship between PA and fatigue was stronger in those participants with less chronic stress. Neither cortisol nor α-amylase was significantly related to physical activity or fatigue. Our study showed an immediate short-term buffering effect of everyday life PA on general fatigue, but only when experiencing lower chronic stress. There seems to be no short-term benefit of PA in the face of higher chronic stress. These findings highlight the importance of considering chronic stress when evaluating the effectiveness of PA interventions in different target populations, in particular among chronically stressed and fatigued subjects.

  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. Strategies for Coping with Stress and Chronic Pain.

    Science.gov (United States)

    Meyer, Genevieve Rogge

    This guide presents strategies used in Pain Management and Stress Reduction workshops for helping the elderly cope with stress and chronic pain. Client evaluations of the workshops are given along with an analysis of the clients' presenting problems. Coping strategies described include: the relaxation response, imagery, daily logs, journal…

  19. 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.

  20. Acute stress decreases but chronic stress increases myocardial sensitivity to ischemic injury in rodents

    Directory of Open Access Journals (Sweden)

    Eric D Eisenmann

    2016-04-01

    Full Text Available 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 increases sensitivity to myocardial ischemia-reperfusion injury. 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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. Stress-Induced Chronic Visceral Pain of Gastrointestinal Origin

    Directory of Open Access Journals (Sweden)

    Beverley Greenwood-Van Meerveld

    2017-11-01

    Full Text Available 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

  6. 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

  7. Effect of Nitrogen Starvation on Desiccation Tolerance of Arctic Microcoleus Strains (Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Daria eTashyreva

    2015-04-01

    Full Text Available Although desiccation tolerance of Microcoleus species is a well-known phenomenon, there is very little information about their limits of desiccation tolerance in terms of cellular water content, the survival rate of their cells, and the environmental factors inducing their resistance to drying. We have discovered that three Microcoleus strains, isolated from terrestrial habitats of the High Arctic, survived extensive dehydration (to 0.23 g water g-1 dry mass, but did not tolerate complete desiccation (to 0.03 g water g-1 dry mass regardless of pre-desiccation treatments. However, these treatments were critical for the survival of incomplete desiccation: cultures grown under optimal conditions failed to survive even incomplete desiccation; a low temperature enabled only 0 to 15% of cells to survive, while 39.8 to 65.9% of cells remained alive and intact after nitrogen starvation. Unlike Nostoc, which co-exists with Microcoleus in Arctic terrestrial habitats, Microcoleus strains are not truly anhydrobiotic and do not possess constitutive desiccation tolerance. Instead, it seems that the survival strategy of Microcoleus in periodically dry habitats involves avoidance of complete desiccation, but tolerance to milder desiccation stress, which is induced by suboptimal conditions (e.g. nitrogen starvation.

  8. The Dichotomous Effect of Chronic Stress on Obesity.

    Science.gov (United States)

    Razzoli, Maria; Bartolomucci, Alessandro

    2016-07-01

    Obesity and metabolic diseases are linked to chronic stress and low socioeconomic status. The mechanistic link between stress and obesity has not been clarified, partly due to the inherent complexity exemplified by the bidirectional effect of stress on eating and body weight. Recent studies focusing on adaptive thermogenesis and brown adipose tissue (BAT) function support a dichotomous relation to explain the impact of stress on obesity: stress promotes obesity in the presence of hyperphagia and unchanged BAT function; stress results in weight loss and/or obesity resistance in the presence of hypophagia, or when hyperphagia is associated with BAT recruitment and enhanced thermogenesis. Mechanistically dissecting the bidirectional effects of stress on metabolic outcomes might open new avenues for innovative pharmacotherapies for the treatment of obesity-associated diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. [Oxidative stress and antioxitant therapy of chronic periodontitis].

    Science.gov (United States)

    Shen, Y X; Guo, S J; Wu, Y F

    2016-07-01

    Chronic periodontitis is a progressive, infectious inflammation disease, caused by the dysbiosis of oral resident flora, leading to the destruction of periodontium. The onset of pathogenic microorganisms is the etiological factor of periodontitis, while the immuno-inflammatory response affects the progression of the disease. Under chronic periodontitis, oxidative stress occurs when excessive reactive oxygen species are produced and exceed the compensative capacity of the organism. Oxidative stress leads to the destruction of periodontium, in a direct way(damaging the biomolecule) or an indirect way(enhancing the produce of inflammatory cytokine and destructive enzymes). Therefore, as the antagonist of the reactive oxygen species, antioxidants may be helpful to treat the chronic periodontitis. This paper reviewed relevant literatures about the destructive role of excessive reactive oxygen species and protective role of antioxidants in chronic periodontitis.

  10. β-Thalassemia and Polycythemia vera: targeting chronic stress erythropoiesis.

    Science.gov (United States)

    Crielaard, Bart J; Rivella, Stefano

    2014-06-01

    β-Thalassemia and Polycythemia vera are genetic disorders which affect the synthesis of red blood cells, also referred to as erythropoiesis. Although essentially different in clinical presentation - patients with β-thalassemia have an impairment in β-globin synthesis leading to defective erythrocytes and anemia, while patients with Polycythemia vera present with high hemoglobin levels because of excessive red blood cell synthesis - both pathologies may characterized by lasting high erythropoietic activity, i.e. chronic stress erythropoiesis. In both diseases, therapeutic strategies targeting chronic stress erythropoiesis may improve the address phenotype and prevent secondary pathology, such as iron overload. The current review will address the basic concepts of these strategies to reduce chronic stress erythropoiesis, which may have significant clinical implications in the near future. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Chronic stress disrupts neural coherence between cortico-limbic structures

    Directory of Open Access Journals (Sweden)

    João Filipe Oliveira

    2013-02-01

    Full Text Available Chronic stress impairs cognitive function, namely on tasks that rely on the integrity of cortico-limbic networks. To unravel the functional impact of progressive stress in cortico-limbic networks we measured neural activity and spectral coherences between the ventral hippocampus (vHIP and the medial prefrontal cortex (mPFC in rats subjected to short term (STS and chronic unpredictable stress (CUS. CUS exposure consistently disrupted the spectral coherence between both areas for a wide range of frequencies, whereas STS exposure failed to trigger such effect. The chronic stress-induced coherence decrease correlated inversely with the vHIP power spectrum, but not with the mPFC power spectrum, which supports the view that hippocampal dysfunction is the primary event after stress exposure. Importantly, we additionally show that the variations in vHIP-to-mPFC coherence and power spectrum in the vHIP correlated with stress-induced behavioral deficits in a spatial reference memory task. Altogether, these findings result in an innovative readout to measure, and follow, the functional events that underlie the stress-induced reference memory impairments.

  12. 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.

  13. 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...

  14. Balancing food and predator pressure induces chronic stress in songbirds.

    OpenAIRE

    Clinchy, Michael; Zanette, Liana; Boonstra, Rudy; Wingfield, John C.; Smith, James N. M.

    2004-01-01

    The never-ending tension between finding food and avoiding predators may be the most universal natural stressor wild animals experience. The 'chronic stress' hypothesis predicts: (i) an animal's stress profile will be a simultaneous function of food and predator pressures given the aforesaid tension; and (ii) these inseparable effects on physiology will produce inseparable effects on demography because of the resulting adverse health effects. This hypothesis was originally proposed to explain...

  15. Chronic Stress and Glucocorticoids: From Neuronal Plasticity to Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Sheela Vyas

    2016-01-01

    Full Text Available Stress and stress hormones, glucocorticoids (GCs, exert widespread actions in central nervous system, ranging from the regulation of gene transcription, cellular signaling, modulation of synaptic structure, and transmission and glial function to behavior. Their actions are mediated by glucocorticoid and mineralocorticoid receptors which are nuclear receptors/transcription factors. While GCs primarily act to maintain homeostasis by inducing physiological and behavioral adaptation, prolonged exposure to stress and elevated GC levels may result in neuro- and psychopathology. There is now ample evidence for cause-effect relationships between prolonged stress, elevated GC levels, and cognitive and mood disorders while the evidence for a link between chronic stress/GC and neurodegenerative disorders such as Alzheimer’s (AD and Parkinson’s (PD diseases is growing. This brief review considers some of the cellular mechanisms through which stress and GC may contribute to the pathogenesis of AD and PD.

  16. 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.

  17. 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...

  18. 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...

  19. 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.

  20. 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.

  1. 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

  2. Signs of chronic stress in women with recurrent candida vulvovaginitis.

    Science.gov (United States)

    Ehrström, Sophia M; Kornfeld, Dan; Thuresson, Jessica; Rylander, Eva

    2005-10-01

    The purpose of this study was to determine whether there is an association between recurrent vulvovaginal candida and chronic stress. Chronic stress affects the hypothalamus-pituitary-adrenal axis, which influences the immune function. Recurrent candida vulvovaginitis is increasing. Women with recurrent vulvovaginal candida (n = 35) and age-matched healthy control subjects (n = 35) collected saliva for the analysis of cortisol. Hormone analyses of blood samples and vulvovaginal examinations were performed. A questionnaire was completed. Morning rise cortisol level was significantly blunted among patients compared with control subjects (P vulvovaginal candida, compared with control subjects. More patients than control subjects reported a history of condyloma, bacterial vaginosis, and herpes genitalis. No differences were seen between patients and control subjects regarding sexual hormone binding globulin, dihydroepiandrosterone, testosterone or Hemoglobin A1c. Morning rise salivary cortisol level is blunted in women with recurrent vulvovaginal candida, which indicates signs of chronic stress. The higher incidence of vulvovaginal infections in these women compared with control subjects may reflect impaired immunity, which may be due to chronic stress.

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

    DEFF Research Database (Denmark)

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

    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...... to a differential stress-coping ability. Thus rats fostered by low maternal care dams became more prone to adopt a stress-susceptible phenotype developing an anhedonic-like condition. Moreover, low maternal care offspring had lower weight gain and lower locomotion, with no additive effect of stress. Subchronic...... exposure to chronic mild stress induced an increase in faecal corticosterone metabolites, which was only significant in rats from low maternal care dams. Examination of glucocorticoid receptor exon 17 promoter methylation in unchallenged adult, maternally characterized rats, showed an insignificant...

  4. 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.

  5. Effects of desiccation stress on adult female longevity in Aedes aegypti and Ae. albopictus (Diptera: Culicidae): results of a systematic review and pooled survival analysis.

    Science.gov (United States)

    Schmidt, Chris A; Comeau, Genevieve; Monaghan, Andrew J; Williamson, Daniel J; Ernst, Kacey C

    2018-04-25

    . Humidity is associated with mortality risk in adult female Ae. aegypti in controlled settings. Data are limited at low humidities, temperature extremes, and for Ae. albopictus, and further studies should be conducted to reduce model uncertainty in these contexts. Desiccation is likely an important factor in Aedes population dynamics and viral transmission in arid regions. Models of Aedes-borne virus transmission may be improved by more comprehensively representing humidity effects.

  6. 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.

  7. Stiffness of desiccating insect wings

    International Nuclear Information System (INIS)

    Mengesha, T E; Vallance, R R; Mittal, R

    2011-01-01

    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 μN mm -1 h -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 -1 . (communication)

  8. 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)

  9. Interplay between cytoskeletal stresses and cell adaptation under chronic flow.

    Directory of Open Access Journals (Sweden)

    Deepika Verma

    Full Text Available Using stress sensitive FRET sensors we have measured cytoskeletal stresses in α-actinin and the associated reorganization of the actin cytoskeleton in cells subjected to chronic shear stress. We show that long-term shear stress reduces the average actinin stress and this effect is reversible with removal of flow. The flow-induced changes in cytoskeletal stresses are found to be dynamic, involving a transient decrease in stress (phase-I, a short-term increase (3-6 min (Phase-II, followed by a longer-term decrease that reaches a minimum in ~20 min (Phase-III, before saturating. These changes are accompanied by reorganization of the actin cytoskeleton from parallel F-actin bundles to peripheral bundles. Blocking mechanosensitive ion channels (MSCs with Gd(3+ and GsMTx4 (a specific inhibitor eliminated the changes in cytoskeletal stress and the corresponding actin reorganization, indicating that Ca(2+ permeable MSCs participate in the signaling cascades. This study shows that shear stress induced cell adaptation is mediated via MSCs.

  10. The Role of Chronic Psychosocial Stress in Explaining Racial Differences in Stress Reactivity and Pain Sensitivity.

    Science.gov (United States)

    Gordon, Jennifer L; Johnson, Jacqueline; Nau, Samantha; Mechlin, Beth; Girdler, Susan S

    To examine the role of psychosocial factors in mediating the relationship between African American (AA) race and both increased pain sensitivity and blunted stress reactivity. Participants included 133 AA and non-Hispanic white (nHW) individuals (mean [SD] age, 37 [9]) matched for age, sex, and socioeconomic status. Participants underwent mental stress testing (Trier Social Stress Test) while cardiovascular, hemodynamic, and neuroendocrine reactivity were measured. Participants completed questionnaires assessing potential sources of psychosocial stress and were tested for pain responses to cold pain and the temporal summation of heat pulses. Mediation analyses were used to determine the extent to which exposure to psychosocial stress accounted for the observed racial differences in stress reactivity and pain. Chronic stress exposure and reactivity to mental stress was largely similar among AAs and nHWs; however, AAs exhibited heightened pain to both cold (p = .012) and heat (p = .004). Racial differences in the relationship between stress reactivity and pain were also observed: while greater stress reactivity was associated with decreased pain among nHWs, reactivity was either unrelated to or even positively associated with pain among AAs (e.g., r = -.21 among nHWs and r = .41 among AAs for stroke volume reactivity and cold pressor intensity). Adjusting for minor racial differences in chronic psychosocial stress did not change these findings. Accounting for psychosocial factors eliminated racial differences in stress reactivity but not racial differences in sensitivity to experimental pain tasks. Increased exposure to chronic stress may not explain AAs' increased pain sensitivity in laboratory settings.

  11. 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.

  12. Anti-stress effect of ethyl acetate soluble fraction of Morus alba in chronic restraint stress.

    Science.gov (United States)

    Nade, Vandana S; Yadav, Adhikrao V

    2010-09-01

    Restraint stress is a well-known method to induce chronic stress which leads to alterations in various behavioral and biochemical parameters. The present work was designed to study anti-stress effects of Morus alba in chronic restraint stress (RS)-induced perturbations in behavioral, biochemical and brain oxidative stress status. The stress was produced by restraining the animals inside an adjustable cylindrical plastic tube for 3 h once daily for ten consecutive days. The ethyl acetate soluble fraction of Morus alba (EASF) 25, 50, 100 mg/kg and diazepam (1 mg/kg) per day was administered 60 min prior to the stress procedure. The behavioral and biochemical parameters such as open field, cognitive dysfunction; leucocytes count; blood glucose and corticosteroid levels were determined. On day 10, the rats were sacrificed and biochemical assessment of superoxide dismutase (SOD), lipid peroxidation (LPO), catalase (CAT), and glutathione reductase (GSH) in whole rat brain were performed. Chronic restraint stress produced cognitive dysfunction, altered behavioral parameters, increased leucocytes count, SOD, LPO, glucose and corticosterone levels, with concomitant decrease in CAT and GSH activities. Gastric ulceration, adrenal gland and spleen weights were also used as the stress indices. All these RS induced perturbations were attenuated by EASF of Morus alba. The results of the study suggest that in addition to its classically established pharmacological activities, the plant also has immense potential as an anti-stress agent of great therapeutic relevance. This study indicates the beneficial role of Morus alba for the treatment of oxidative stress-induced disorders.

  13. Variety of immune responses to chronic stress in rats male

    Directory of Open Access Journals (Sweden)

    Іlona S Polovynko

    2016-12-01

    Full Text Available Background. Previously we have been carry out integrated quantitative estimation of neuroendocrine and immune responses to chronic restraint stress in male rats. Revealed that the value of canonical discriminant roots rats subjected to chronic stress different not only on the values of intact animals (by definition, but also among themselves. So we set a goal retrospectively divided stressed rats into three homogeneous groups. Material and methods. The experiment is at 50 white male rats. Of these 10 animals not subjected to any influences and 40 within 7 days subjected to moderate stress by daily 30-minute immobilization. The day after the completion of stressing in portion of the blood immunological parameters were determined by tests I and II levels of WHO. The spleen and thymus did smears for counting spleno- and thymocytograms. Results. The method of cluster analysis (k-means clustering formed three groups-clusters. For further analysis selected 18 parameters that members of each cluster differing minimum and maximum are different from members of other clusters (η2=0,73÷0,15; F=49,0÷3,26; p=10-6÷0,05. We stated that in 16 rats from cluster III the deviation 16 parameters in either side of the average norm almost identical and are in an acceptable range of ±0,5σ. Thus, the immune status of 40% of the rats subjected to moderate chronic stress was resistant to its factors. For the immune status of the 15 (37,5% rats cluster II typical moderate inhibition microphage, killer and T-cellular links in combination with a strong activation macrophage link. Poststressory changes in immunity in 9 rats (22,5% from cluster I differ from those in cluster II both qualitatively and quantitatively. In particular, the rats in this cluster were found no deviations from the norm or reaction blast transformation T-cells nor NK-lymphocytes levels. However, other parameters of T-link and microhage link suppressed more and settings macrophage link appeared

  14. 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.

  15. 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.

  16. 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.

  17. 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...... as having CH then further described as having medication-overuse headache (MOH) or CH without medication overuse. Associations between headache and daily smoking, physical inactivity, obesity, excessive drinking, illicit drug use, and high stress were analysed by logistic regression. RESULTS: CH...... with and without medication overuse (prevalence 1.8% and 1.6%, respectively) had strong, graded associations with stress. Associations with daily smoking, physical inactivity, and obesity were significant only for MOH. Odds for MOH were highest among people who had all three factors compared to those who had none...

  18. Sex differences in chronic stress responses and Alzheimer's disease.

    Science.gov (United States)

    Yan, Yan; Dominguez, Sky; Fisher, Daniel W; Dong, Hongxin

    2018-02-01

    Clinical studies indicate that Alzheimer's disease (AD) disproportionately affects women in both disease prevalence and severity, but the mechanisms underlying this sex divergence are unknown. Though some have suggested this difference in risk is a reflection of known differences in longevity between men and women, mounting clinical and preclinical evidence supports women also having intrinsic susceptibilities towards the disease. While a number of potential risk factors have been hypothesized to affect these differences in risks, none have been definitively verified. In this review, we discuss a novel hypothesis whereby women's susceptibility to chronic stress also mediates increased risk for AD. As stress is a risk factor for AD, and women are twice as likely to develop mood disorders where stress is a major etiology, it is possible that sex dimorphisms in stress responses contribute to the increase in women with AD. In line with this, sex divergence in biochemical responses to stress have been noted along the hypothalamic-pituitary-adrenal (HPA) axis and among known molecular effectors of AD, with crosstalk between these processes also being likely. In addition, activation of the cortical corticotrophin-releasing factor receptor 1 (CRF1) signaling pathway leads to distinct female-biased increases in molecules associated with AD pathogenesis. Therefore, the different biochemical responses to stress between women and men may represent an intrinsic, sex-dependent risk factor for AD.

  19. Chronic stress, cortisol dysfunction, and pain: a psychoneuroendocrine rationale for stress management in pain rehabilitation.

    Science.gov (United States)

    Hannibal, Kara E; Bishop, Mark D

    2014-12-01

    Pain is a primary symptom driving patients to seek physical therapy, and its attenuation commonly defines a successful outcome. A large body of evidence is dedicated to elucidating the relationship between chronic stress and pain; however, stress is rarely addressed in pain rehabilitation. A physiologic stress response may be evoked by fear or perceived threat to safety, status, or well-being and elicits the secretion of sympathetic catecholamines (epinephrine and norepinepherine) and neuroendocrine hormones (cortisol) to promote survival and motivate success. Cortisol is a potent anti-inflammatory that functions to mobilize glucose reserves for energy and modulate inflammation. Cortisol also may facilitate the consolidation of fear-based memories for future survival and avoidance of danger. Although short-term stress may be adaptive, maladaptive responses (eg, magnification, rumination, helplessness) to pain or non-pain-related stressors may intensify cortisol secretion and condition a sensitized physiologic stress response that is readily recruited. Ultimately, a prolonged or exaggerated stress response may perpetuate cortisol dysfunction, widespread inflammation, and pain. Stress may be unavoidable in life, and challenges are inherent to success; however, humans have the capability to modify what they perceive as stressful and how they respond to it. Exaggerated psychological responses (eg, catastrophizing) following maladaptive cognitive appraisals of potential stressors as threatening may exacerbate cortisol secretion and facilitate the consolidation of fear-based memories of pain or non-pain-related stressors; however, coping, cognitive reappraisal, or confrontation of stressors may minimize cortisol secretion and prevent chronic, recurrent pain. Given the parallel mechanisms underlying the physiologic effects of a maladaptive response to pain and non-pain-related stressors, physical therapists should consider screening for non-pain-related stress to

  20. Effects of chronic stress on the brain – the evidence from morphological examinations of hippocampus in a chronic unpredictable stress (CUS model in rats

    Directory of Open Access Journals (Sweden)

    Joanna Sekita-Krzak

    2016-12-01

        Abstract Background. Chronic stress exposure deteriorates memory and increases the risk of psychiatric disorders, including depression. Objectives. The objective of this study was to perform morphological studies in experimental model of neuropsychiatric disorder and to assess histologically the effect of chronic unpredictable stress procedure (CUS influence on hippocampus. Material and methods. Chronic unpredictable stress procedure (CUS was applied for 8 weeks in rats by the modified method described by Katz et al. Experimental model of neuropsychiatric disorder was used based on morphological studies of hippocampal formation. Results. Stress-induced alterations were observed in the hippocampus. Nerve cell changes included  neuron shrinkage and dendritic remodeling. The most vulnerable hippocampal cells to chronic stress were CA3 and CA4 pyramidal neurons. In dentate gyrus chronic stress led to granule neuron shrinkage and slight exacerbation of apoptosis in the polygonal cell layer. CUS led to statistically significant changes in quantitative characteristics of the CA3 and CA4 neuron size and nuclei diameter. Conclusions. Chronic stress induces degeneration of hippocampal neurons. The observed neuronal changes indicate the damage of the neurons did not involve neither apoptosis nor necrosis Similarity between histological changes obtained in 8-week long CUS procedure applied in our research and morphological changes described in depressed patients confirms the usefulness of the applied stress procedure as the experimental model of depression.   Key words: stress, depression, hippocampus, chronic unpredictable stress procedure (CUS, animal model, morphology.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. 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.

  3. Effects of stress on heart rate complexity--a comparison between short-term and chronic stress.

    Science.gov (United States)

    Schubert, C; Lambertz, M; Nelesen, R A; Bardwell, W; Choi, J-B; Dimsdale, J E

    2009-03-01

    This study examined chronic and short-term stress effects on heart rate variability (HRV), comparing time, frequency and phase domain (complexity) measures in 50 healthy adults. The hassles frequency subscale of the combined hassles and uplifts scale (CHUS) was used to measure chronic stress. Short-term stressor reactivity was assessed with a speech task. HRV measures were determined via surface electrocardiogram (ECG). Because respiration rate decreased during the speech task (pshort-term stress decreased HR D2 (calculated via the pointwise correlation dimension PD2) (pshort-term stress. Partial correlation adjusting for respiration rate showed that HR D2 was associated with chronic stress (r=-.35, p=.019). Differential effects of chronic and short-term stress were observed on several HRV measures. HR D2 decreased under both stress conditions reflecting lowered functionality of the cardiac pacemaker. The results confirm the importance of complexity metrics in modern stress research on HRV.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Identification by phenotypic and genetic approaches of an indigenous Saccharomyces cerevisiae wine strain with high desiccation tolerance.

    Science.gov (United States)

    Zambuto, Marianna; Romaniello, Rossana; Guaragnella, Nicoletta; Romano, Patrizia; Votta, Sonia; Capece, Angela

    2017-10-01

    During active dry yeast (ADY) production process, cells are exposed to multiple stresses, such as thermal, oxidative and hyperosmotic shock. Previously, by analysing cells in exponential growth phase, we selected an indigenous Saccharomyces cerevisiae wine strain, namely CD-6Sc, for its higher tolerance to desiccation and higher expression of specific desiccation stress-related genes in comparison to other yeast strains. In this study, we performed a desiccation treatment on stationary phase cells by comparing the efficacy of two different methods: a 'laboratory dry test' on a small scale (mild stress) and a treatment by spray-drying (severe stress), one of the most appropriate preservation method for yeasts and other micro-organisms. The expression of selected desiccation-related genes has been also assessed in order to validate predictive markers for desiccation tolerance. Our data demonstrate that the 'mild' and the 'severe' desiccation treatments give similar results in terms of cell recovery, but the choice of marker genes strictly depends on the growth phase in which cells undergo desiccation. The indigenous CD-6Sc was ultimately identified as a high dehydration stress-tolerant indigenous strain suitable for ADY production. This study highlights the exploitation of natural yeast biodiversity as a source of hidden technological features and as an alternative approach to strain improvement by genetic modifications. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  6. Effects of Chronic Central Arginine Vasopressin (AVP) on Maternal Behavior in Chronically Stressed Rat Dams

    Science.gov (United States)

    Coverdill, Alexander J.; McCarthy, Megan; Bridges, Robert S.; Nephew, Benjamin C.

    2012-01-01

    Exposure of mothers to chronic stressors during pregnancy or the postpartum period often leads to the development of depression, anxiety, or other related mood disorders. The adverse effects of mood disorders are often mediated through maternal behavior and recent work has identified arginine vasopressin (AVP) as a key neuropeptide hormone in the expression of maternal behavior in both rats and humans. Using an established rodent model that elicits behavioral and physiological responses similar to human mood disorders, this study tested the effectiveness of chronic AVP infusion as a novel treatment for the adverse effects of exposure to chronic social stress during lactation in rats. During early (day 3) and mid (day 10) lactation, AVP treatment significantly decreased the latency to initiate nursing and time spent retrieving pups, and increased pup grooming and total maternal care (sum of pup grooming and nursing). AVP treatment was also effective in decreasing maternal aggression and the average duration of aggressive bouts on day 3 of lactation. Central AVP may be an effective target for the development of treatments for enhancing maternal behavior in individuals exposed to chronic social stress. PMID:24349762

  7. Chronic unpredictable stress deteriorates the chemopreventive efficacy of pomegranate through oxidative stress pathway.

    Science.gov (United States)

    Hasan, Shirin; Suhail, Nida; Bilal, Nayeem; Ashraf, Ghulam Md; Zaidi, Syed Kashif; AlNohair, Sultan; Banu, Naheed

    2016-05-01

    Chronic unpredictable stress (CUS) can influence the risk and progression of cancer through increased oxidative stress. Pomegranate is known to protect carcinogenesis through its anti-oxidative properties. This study is carried out to examine whether CUS affects the chemopreventive potential of pomegranate through oxidative stress pathway. Role of CUS on early stages of 7, 12 dimethyl benz(a) anthracene (DMBA) induced carcinogenesis, and its pre-exposure effect on chemopreventive efficacy of pomegranate juice (PJ) was examined in terms of in vivo antioxidant and biochemical parameters in Swiss albino rats. Rats were divided in various groups and were subjected to CUS paradigm, DMBA administration (65 mg/kg body weight, single dose), and PJ treatment. Exposure to stress (alone) and DMBA (alone) led to increased oxidative stress by significantly decreasing the antioxidant enzymes activities and altering the glutathione (GSH), malondialdehyde (MDA), glutamate oxaloacetate transaminase (GOT), and glutamate pyruvate transaminase (GPT) levels. A significant increase in DNA damage demonstrated by comet assay was seen in the liver cells. Stress exposure to DMBA-treated rats further increased the oxidative stress and disturbed the biochemical parameters as compared to DMBA (alone)-treated rats. Chemoprevention with PJ in DMBA (alone)-treated rats restored the altered parameters. However, in the pre-stress DMBA-treated rats, the overall antioxidant potential of PJ was significantly diminished. Our results indicate that chronic stress not only increases the severity of carcinogenesis but also diminishes the anti-oxidative efficacy of PJ. In a broader perspective, special emphasis should be given to stress management and healthy diet during cancer chemoprevention.

  8. 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.

  9. 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.

  10. Stress

    Science.gov (United States)

    ... can be life-saving. But chronic stress can cause both physical and mental harm. There are at least three different types of stress: Routine stress related to the pressures of work, family, and other daily responsibilities Stress brought about ...

  11. Dysregulated stress signal sensitivity and inflammatory disinhibition as a pathophysiological mechanism of stress-related chronic fatigue.

    Science.gov (United States)

    Strahler, Jana; Skoluda, Nadine; Rohleder, Nicolas; Nater, Urs M

    2016-09-01

    Chronic stress and its subsequent effects on biological stress systems have long been recognized as predisposing and perpetuating factors in chronic fatigue, although the exact mechanisms are far from being completely understood. In this review, we propose that sensitivity of immune cells to glucocorticoids (GCs) and catecholamines (CATs) may be the missing link in elucidating how stress turns into chronic fatigue. We searched for in vitro studies investigating the impact of GCs or CATs on mitogen-stimulated immune cells in chronically stressed or fatigued populations, with 34 original studies fulfilling our inclusion criteria. Besides mixed cross-sectional findings for stress- and fatigue-related changes of GC sensitivity under basal conditions or acute stress, longitudinal studies indicate a decrease with ongoing stress. Research on CATs is still scarce, but initial findings point towards a reduction of CAT sensitivity under chronic stress. In the long run, resistance of immune cells to stress signals under conditions of chronic stress might translate into self-maintaining inflammation and inflammatory disinhibition under acute stress, which in turn lead to fatigue. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. 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.

  13. Steady state modeling of desiccant wheels

    DEFF Research Database (Denmark)

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

    2014-01-01

    Desiccant wheels are rotary desiccant dehumidifiers used in air conditioning and drying applications. The modeling of simultaneous heat and mass transfer in these components is crucial for estimating their performances, as well as for simulating and optimizing their implementation in complete...

  14. 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

  15. 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.

  16. Stress and Sleep Duration Predict Headache Severity in Chronic Headache Sufferers

    OpenAIRE

    Houle, Timothy T.; Butschek, Ross A.; Turner, Dana P.; Smitherman, Todd A.; Rains, Jeanetta C.; Penzien, Donald B.

    2012-01-01

    The objective of this study was to evaluate the time-series relationships between stress, sleep duration, and headache pain among patients with chronic headaches. Sleep and stress have long been recognized as potential triggers of episodic headache (< 15 headache days/month), though prospective evidence is inconsistent and absent in patients diagnosed with chronic headaches (≥ 15 days/month). We reanalyzed data from a 28-day observational study of chronic migraine (n = 33) and chronic tension...

  17. The effect of somatic awareness exercise on the chronic physical manifestations of the stress response

    OpenAIRE

    2013-01-01

    M.Phil. (Biokinetics) Stress is an integral part of daily living and supports the ability to adapt. However, chronic activation without the ability to express the physical response results in overloading the physiological and psychological systems. Since urban South Africans are sedentary and experience high levels of stress, they are developing stress related chronic conditions and hypokinetic diseases (obesity, hypertension, depression). This study is aimed at decreasing the chronic phys...

  18. Effects of Active Mastication on Chronic Stress-Induced Bone Loss in Mice.

    Science.gov (United States)

    Azuma, Kagaku; Furuzawa, Manabu; Fujiwara, Shu; Yamada, Kumiko; Kubo, Kin-ya

    2015-01-01

    Chronic psychologic stress increases corticosterone levels, which decreases bone density. Active mastication or chewing attenuates stress-induced increases in corticosterone. We evaluated whether active mastication attenuates chronic stress-induced bone loss in mice. Male C57BL/6 (B6) mice were randomly divided into control, stress, and stress/chewing groups. Stress was induced by placing mice in a ventilated restraint tube (60 min, 2x/day, 4 weeks). The stress/chewing group was given a wooden stick to chew during the experimental period. Quantitative micro-computed tomography, histologic analysis, and biochemical markers were used to evaluate the bone response. The stress/chewing group exhibited significantly attenuated stress-induced increases in serum corticosterone levels, suppressed bone formation, enhanced bone resorption, and decreased trabecular bone mass in the vertebrae and distal femurs, compared with mice in the stress group. Active mastication during exposure to chronic stress alleviated chronic stress-induced bone density loss in B6 mice. Active mastication during chronic psychologic stress may thus be an effective strategy to prevent and/or treat chronic stress-related osteopenia.

  19. Chronic stress-induced effects of corticosterone on brain: direct and indirect

    NARCIS (Netherlands)

    Dallman, M. F.; Akana, S. F.; Strack, A. M.; Scribner, K. S.; Pecoraro, N.; La Fleur, S. E.; Houshyar, H.; Gomez, F.

    2004-01-01

    Acutely, glucocorticoids act to inhibit stress-induced corticotrophin-releasing factor (CRF) and adrenocorticotrophic hormone (ACTH) secretion through their actions in brain and anterior pituitary (canonical feedback). With chronic stress, glucocorticoid feedback inhibition of ACTH secretion changes

  20. The brain-derived neurotrophic factor pathway, life stress, and chronic multi-site musculoskeletal pain.

    Science.gov (United States)

    Generaal, Ellen; Milaneschi, Yuri; Jansen, Rick; Elzinga, Bernet M; Dekker, Joost; Penninx, Brenda W J H

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) disturbances and life stress, both independently and in interaction, have been hypothesized to induce chronic pain. We examined whether (a) the BDNF pathway (val(66)met genotype, gene expression, and serum levels), (b) early and recent life stress, and (c) their interaction are associated with the presence and severity of chronic multi-site musculoskeletal pain. Cross-sectional data are from 1646 subjects of the Netherlands Study of Depression and Anxiety. The presence and severity of chronic multi-site musculoskeletal pain were determined using the Chronic Pain Grade (CPG) questionnaire. The BDNF val(66)met polymorphism, BDNF gene expression, and BDNF serum levels were measured. Early life stress before the age of 16 was assessed by calculating a childhood trauma index using the Childhood Trauma Interview. Recent life stress was assessed as the number of recent adverse life events using the List of Threatening Events Questionnaire. Compared to val(66)val, BDNF met carriers more often had chronic pain, whereas no differences were found for BDNF gene expression and serum levels. Higher levels of early and recent stress were both associated with the presence and severity of chronic pain (p stress in the associations with chronic pain presence and severity. This study suggests that the BDNF gene marks vulnerability for chronic pain. Although life stress did not alter the impact of BDNF on chronic pain, it seems an independent factor in the onset and persistence of chronic pain. © The Author(s) 2016.

  1. Sugars and Desiccation Tolerance in Seeds 1

    Science.gov (United States)

    Koster, Karen L.; Leopold, A. Carl

    1988-01-01

    Soluble sugars have been shown to protect liposomes and lobster microsomes from desiccation damage, and a protective role has been proposed for them in several anhydrous systems. We have studied the relationship between soluble sugar content and the loss of desiccation tolerance in the axes of germinating soybean (Glycine max L. Merr. cv Williams), pea (Pisum sativum L. cv Alaska), and corn (Zea mays L. cv Merit) axes. The loss of desiccation tolerance during imbibition was monitored by following the ability of seeds to germinate after desiccation following various periods of preimbibition and by following the rates of electrolyte leakage from dried, then rehydrated axes. Finally, we analyzed the soluble sugar contents of the axes throughout the transition from desiccation tolerance to intolerance. These analyses show that sucrose and larger oligosaccharides were consistently present during the tolerant stage, and that desiccation tolerance disappeared as the oligosaccharides were lost. The results support the idea that sucrose may serve as the principal agent of desiccation tolerance in these seeds, with the larger oligosaccharides serving to keep the sucrose from crystallizing. PMID:16666392

  2. 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.

  3. Molecular strategies of the Caenorhabditis elegans dauer larva to survive extreme desiccation.

    Directory of Open Access Journals (Sweden)

    Cihan Erkut

    Full Text Available Massive water loss is a serious challenge for terrestrial animals, which usually has fatal consequences. However, some organisms have developed means to survive this stress by entering an ametabolic state called anhydrobiosis. The molecular and cellular mechanisms underlying this phenomenon are poorly understood. We recently showed that Caenorhabditis elegans dauer larva, an arrested stage specialized for survival in adverse conditions, is resistant to severe desiccation. However, this requires a preconditioning step at a mild desiccative environment to prepare the organism for harsher desiccation conditions. A systems approach was used to identify factors that are activated during this preconditioning. Using microarray analysis, proteomics, and bioinformatics, genes, proteins, and biochemical pathways that are upregulated during this process were identified. These pathways were validated via reverse genetics by testing the desiccation tolerances of mutants. These data show that the desiccation response is activated by hygrosensation (sensing the desiccative environment via head neurons. This leads to elimination of reactive oxygen species and xenobiotics, expression of heat shock and intrinsically disordered proteins, polyamine utilization, and induction of fatty acid desaturation pathway. Remarkably, this response is specific and involves a small number of functional pathways, which represent the generic toolkit for anhydrobiosis in plants and animals.

  4. Comparing chronic interpersonal and noninterpersonal stress domains as predictors of depression recurrence in emerging adults.

    Science.gov (United States)

    Sheets, Erin S; Craighead, W Edward

    2014-12-01

    Understanding how persistent interpersonal difficulties distinctly affect the course of major depressive disorder (MDD) during emerging adulthood is critical, given that early experiences impact future coping resources and functioning. Research on stress and MDD has mostly concentrated on stressful life events, while chronic stress largely has not been explored. The present study examined interpersonal (intimate relationship, close friendships, social life, family relationships) and noninterpersonal (academic, work, financial, personal health, and family members' health) domains of chronic stress as time-varying predictors of depressive recurrence in emerging adults. Baseline assessments identified previously depressed emerging adults (N = 119), who subsequently completed 6-month, 12-month and 18-month follow-up interviews to determine chronic stress experiences and onset of new major depressive episodes. Survival analyses indicated that time-varying total chronic stress and chronic interpersonal stress predicted higher risk for depression recurrence; however, chronic noninterpersonal stress was not associated with recurrence. Intimate relationship stress, close friendship stress, family relationship stress, personal health, and family members' health independently predicted MDD recurrence, over and above well-established depression risk factors of dysfunctional cognitions and personality disorder symptoms. Evidence that interpersonal stress could have substantial impact on course of depression is consistent with theories of emerging adulthood, a time when young people are individuating from the family and experiencing significant social transition. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Chronic variable stress improves glucose tolerance in rats with sucrose-induced prediabetes

    Science.gov (United States)

    Packard, Amy E. B.; Ghosal, Sriparna; Herman, James P.; Woods, Stephen C.; Ulrich-Lai, Yvonne M.

    2014-01-01

    The incidence of type-2 diabetes (T2D) and the burden it places on individuals, as well as society as a whole, compels research into the causes, factors and progression of this disease. Epidemiological studies suggest that chronic stress exposure may contribute to the development and progression of T2D in human patients. To address the interaction between chronic stress and the progression of T2D, we developed a dietary model of the prediabetic state in rats utilizing unlimited access to 30% sucrose solution (in addition to unlimited access to normal chow and water), which led to impaired glucose tolerance despite elevated insulin levels. We then investigated the effects of a chronic variable stress paradigm (CVS; twice daily exposure to an unpredictable stressor for 2 weeks) on metabolic outcomes in this prediabetic model. Chronic stress improved glucose tolerance in prediabetic rats following a glucose challenge. Importantly, pair-fed control groups revealed that the beneficial effect of chronic stress did not result from the decreased food intake or body weight gain that occurred during chronic stress. The present work suggests that chronic stress in rodents can ameliorate the progression of diet-induced prediabetic disease independent of chronic stress-induced decreases in food intake and body weight. PMID:25001967

  12. Effect of individually tailored biopsychosocial workplace interventions on chronic musculoskeletal pain and stress among laboratory technicians

    DEFF Research Database (Denmark)

    Jay, Kenneth; Brandt, Mikkel; Hansen, Klaus

    2015-01-01

    BACKGROUND: Chronic musculoskeletal pain is prevalent among laboratory technicians and work-related stress may aggravate the problem. OBJECTIVES: This study investigated the effect of a multifaceted worksite intervention on pain and stress among laboratory technicians with chronic musculoskeletal......: neck, shoulder, lower and upper back, elbow, and hand at 10 week follow-up. The secondary outcome measure was stress assessed by Cohen´s perceived stress questionnaire. In addition, an explorative dose-response analysis was performed on the adherence to PCMT with pain and stress, respectively......, as outcome measures. RESULTS: A significant (P stress was observed (treatment by time P = 0.16). Exploratory analyses for each body...

  13. 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.

  14. Desiccation tolerance in bryophytes: The dehydration and rehydration transcriptomes in the desiccation-tolerant bryophyte Bryum argenteum.

    Science.gov (United States)

    Gao, Bei; Li, Xiaoshuang; Zhang, Daoyuan; Liang, Yuqing; Yang, Honglan; Chen, Moxian; Zhang, Yuanming; Zhang, Jianhua; Wood, Andrew J

    2017-08-08

    The desiccation tolerant bryophyte Bryum argenteum is an important component of desert biological soil crusts (BSCs) and is emerging as a model system for studying vegetative desiccation tolerance. Here we present and analyze the hydration-dehydration-rehydration transcriptomes in B. argenteum to establish a desiccation-tolerance transcriptomic atlas. B. argenteum gametophores representing five different hydration stages (hydrated (H0), dehydrated for 2 h (D2), 24 h (D24), then rehydrated for 2 h (R2) and 48 h (R48)), were sampled for transcriptome analyses. Illumina high throughput RNA-Seq technology was employed and generated more than 488.46 million reads. An in-house de novo transcriptome assembly optimization pipeline based on Trinity assembler was developed to obtain a reference Hydration-Dehydration-Rehydration (H-D-R) transcriptome comprising of 76,206 transcripts, with an N50 of 2,016 bp and average length of 1,222 bp. Comprehensive transcription factor (TF) annotation discovered 978 TFs in 62 families, among which 404 TFs within 40 families were differentially expressed upon dehydration-rehydration. Pfam term enrichment analysis revealed 172 protein families/domains were significantly associated with the H-D-R cycle and confirmed early rehydration (i.e. the R2 stage) as exhibiting the maximum stress-induced changes in gene expression.

  15. 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

  16. Chronic parenting stress and mood reactivity: The role of sleep quality.

    Science.gov (United States)

    da Estrela, Chelsea; Barker, Erin T; Lantagne, Sarah; Gouin, Jean-Philippe

    2018-04-01

    Sleep is a basic biological process supporting emotion regulation. The emotion regulation function of sleep may be particularly important in the context of chronic stress. To better understand how chronic stress and sleep interact to predict mood, 66 parents of children with autism completed daily diaries assessing parenting stress, negative mood, and sleep quality for 6 consecutive days. Hierarchical linear modelling revealed that daily negative mood was predicted by between-person differences in parenting stress and between-person differences in sleep efficiency. Further, between-person differences in sleep efficiency and within-person differences in sleep satisfaction moderated the impact of stress on mood. These data suggest that sleep disturbances may exacerbate the association between stress and mood in the context of chronic parenting stress. Further, high parenting stress appears to heighten the impact of transient sleep disturbances on mood. Copyright © 2017 John Wiley & Sons, Ltd.

  17. 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.

  18. Effects of stress on heart rate complexity—A comparison between short-term and chronic stress

    OpenAIRE

    Schubert, C.; Lambertz, M.; Nelesen, R.A.; Bardwell, W.; Choi, J.-B.; Dimsdale, J.E.

    2008-01-01

    This study examined chronic and short-term stress effects on heart rate variability (HRV), comparing time, frequency and phase domain (complexity) measures in 50 healthy adults. The hassles frequency subscale of the combined hassles and uplifts scale (CHUS) was used to measure chronic stress. Short-term stressor reactivity was assessed with a speech task. HRV measures were determined via surface electrocardiogram (ECG). Because respiration rate decreased during the speech task (p < .001), thi...

  19. 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.

  20. Desiccation induces accumulations of antheraxanthin and zeaxanthin in intertidal macro-alga Ulva pertusa (Chlorophyta.

    Directory of Open Access Journals (Sweden)

    Xiujun Xie

    Full Text Available For plants and algae, exposure to high light levels is deleterious to their photosynthetic machineries. It also can accelerate water evaporation and thus potentially lead to drought stress. Most photosynthetic organisms protect themselves against high light caused photodamages by xanthophyll cycle-dependent thermal energy dissipation. It is generally accepted that high light activates xanthophyll cycle. However, the relationship between xanthophyll cycle and drought stress remains ambiguous. Herein, Ulva pertusa (Chlorophyta, a representative perennial intertidal macro-algae species with high drought-tolerant capabilities and simple structures, was used to investigate the operation of xanthophyll cycle during desiccation in air. The results indicate that desiccation under dim light induced accumulation of antheraxanthin (Ax and zeaxanthin (Zx at the expense of violaxanthin (Vx. This accumulation could be arrested by dithiothreitol completely and by uncoupler (carbonyl cyanide p-trifluoromethoxyphenylhydrazone partially, implying the participation of Vx de-epoxidase in conversion of Vx to Ax and Zx. Treatment with inhibitors of electron transport along thylakoid membrane, e.g. DCMU, PG and DBMIB, did not significantly arrest desiccation-induced accumulation of Ax and Zx. We propose that for U. pertusa, besides excess light, desiccation itself could also induce accumulation of Ax and Zx. This accumulation could proceed without electron transport along thylakoid membrane, and is possibly resulting from the reduction of thylakoid lumen volume during desiccation. Considering the pleiotropic effects of Ax and Zx, accumulated Ax and Zx may function in protecting thylakoid membrane and enhancing thermal quenching during emersion in air.

  1. 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

  2. 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.

  3. 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

  4. Resilience to chronic stress is mediated by hippocampal brain-derived neurotrophic factor.

    Science.gov (United States)

    Taliaz, Dekel; Loya, Assaf; Gersner, Roman; Haramati, Sharon; Chen, Alon; Zangen, Abraham

    2011-03-23

    Chronic stress is a trigger for several psychiatric disorders, including depression; however, critical individual differences in resilience to both the behavioral and the neurochemical effects of stress have been reported. A prominent mechanism by which the brain reacts to acute and chronic stress is activation of the hypothalamic-pituitary-adrenal (HPA) axis, which is inhibited by the hippocampus via a polysynaptic circuit. Alterations in secretion of stress hormones and levels of brain-derived neurotrophic factor (BDNF) in the hippocampus were implicated in depression and the effects of antidepressant medications. However, the potential role of hippocampal BDNF in behavioral resilience to chronic stress and in the regulation of the HPA axis has not been evaluated. In the present study, Sprague Dawley rats were subjected to 4 weeks of chronic mild stress (CMS) to induce depressive-like behaviors after lentiviral vectors were used to induce localized BDNF overexpression or knockdown in the hippocampus. The behavioral outcome was measured during 3 weeks after the CMS procedure, then plasma samples were taken for measurements of corticosterone levels, and finally hippocampal tissue was taken for BDNF measurements. We found that hippocampal BDNF expression plays a critical role in resilience to chronic stress and that reduction of hippocampal BDNF expression in young, but not adult, rats induces prolonged elevations in corticosterone secretion. The present study describes a mechanism for individual differences in responses to chronic stress and implicates hippocampal BDNF in the development of neural circuits that control adequate stress adaptations.

  5. The effects of chronic stress on the human brain: From neurotoxicity, to vulnerability, to opportunity.

    Science.gov (United States)

    Lupien, Sonia J; Juster, Robert-Paul; Raymond, Catherine; Marin, Marie-France

    2018-04-01

    For the last five decades, science has managed to delineate the mechanisms by which stress hormones can impact on the human brain. Receptors for glucocorticoids are found in the hippocampus, amygdala and frontal cortex, three brain regions involved in memory processing and emotional regulation. Studies have shown that chronic exposure to stress is associated with reduced volume of the hippocampus and that chronic stress can modulate volumes of both the amygdala and frontal cortex, suggesting neurotoxic effects of stress hormones on the brain. Yet, other studies report that exposure to early adversity and/or familial/social stressors can increase vulnerability to stress in adulthood. Models have been recently developed to describe the roles that neurotoxic and vulnerability effects can have on the developing brain. These models suggest that developing early stress interventions could potentially counteract the effects of chronic stress on the brain and results going along with this hypothesis are summarized. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. 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

    . 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......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...

  7. [Unpredictable chronic mild stress effects on antidepressants activities in forced swim test].

    Science.gov (United States)

    Kudryashov, N V; Kalinina, T S; Voronina, T A

    2015-02-01

    The experiments has been designed to study unpredictable chronic mild stress effect on anti-depressive activities of amitriptyline (10 mg/kg) and fluoxetine (20 mg/kg) in forced swim test in male outbred mice. It is shown that acute treatment with fluoxetine does not produce any antidepressant effects in mice following stress of 14 days while the sub-chronic injections of fluoxetine result in more deep depressive-like behavior. In 28 daily stressed mice, antidepressant effect of fluoxetine is observed independently of the injection rates. Amitriptyline demonstrates the antidepressant activity regardless of the duration of stress or administration scheduling, but at the same time the severity of anti-immobilization effect of amitriptyline in stressed mice is weaker in compare to non-stressed trails. Thus, the injection rates and duration of unpredictable mild chronic stress are the parameters that determine the efficiency of antidepressants in the mouse forced swimming test.

  8. Chronic and episodic stress predict physical symptom bother following breast cancer diagnosis.

    Science.gov (United States)

    Harris, Lauren N; Bauer, Margaret R; Wiley, Joshua F; Hammen, Constance; Krull, Jennifer L; Crespi, Catherine M; Weihs, Karen L; Stanton, Annette L

    2017-12-01

    Breast cancer patients often experience adverse physical side effects of medical treatments. According to the biobehavioral model of cancer stress and disease, life stress during diagnosis and treatment may negatively influence the trajectory of women's physical health-related adjustment to breast cancer. This longitudinal study examined chronic and episodic stress as predictors of bothersome physical symptoms during the year after breast cancer diagnosis. Women diagnosed with breast cancer in the previous 4 months (N = 460) completed a life stress interview for contextual assessment of chronic and episodic stress severity at study entry and 9 months later. Physical symptom bother (e.g., pain, fatigue) was measured at study entry, every 6 weeks through 6 months, and at nine and 12 months. In multilevel structural equation modeling (MSEM) analyses, both chronic stress and episodic stress occurring shortly after diagnosis predicted greater physical symptom bother over the study period. Episodic stress reported to have occurred prior to diagnosis did not predict symptom bother in MSEM analyses, and the interaction between chronic and episodic stress on symptom bother was not significant. Results suggest that ongoing chronic stress and episodic stress occurring shortly after breast cancer diagnosis are important predictors of bothersome symptoms during and after cancer treatment. Screening for chronic stress and recent stressful life events in the months following diagnosis may help to identify breast cancer patients at risk for persistent and bothersome physical symptoms. Interventions to prevent or ameliorate treatment-related physical symptoms may confer added benefit by addressing ongoing non-cancer-related stress in women's lives.

  9. An efficient chronic unpredictable stress protocol to induce stress-related responses in C57BL/6 mice

    Directory of Open Access Journals (Sweden)

    Susana eMonteiro

    2015-02-01

    Full Text Available Exposure to chronic stress can have broad effects on health ranging from increased predisposition for neuropsychiatric disorders to deregulation of immune responses. The chronic unpredictable stress (CUS protocol has been widely used to study the impact of stress exposure in several animal models and consists in the random, intermittent and unpredictable exposure to a variety of stressors during several weeks. CUS has consistently been shown to induce behavioral and immunological alterations typical of the chronic stress response. Unfortunately C57BL/6 mice, one of the most widely used mouse strains, due to the great variety of genetically modified lines, seem to be resistant to the commonly used 4-week-long CUS protocol. The definition of an alternative CUS protocol allowing the use of C57BL/6 mice in chronic stress experiments is a need. Here we show that by extending the CUS protocol to 8 weeks is possible to induce a chronic stress response in C57BL/6 mice, as revealed by abrogated body weight gain, increased adrenals weight and an overactive hypothalamic-pituitary-adrenal (HPA axis with increased levels of serum corticosterone. Moreover, we also observed stress-associated behavioral alterations, including the potentiation of anxious-like and depressive-like behaviors and a reduction of exploratory behavior, as well as subtle stress-related changes in the cell population of the thymus and of the spleen.The present protocol for C57BL/6 mice consistently triggers the spectrum of CUS-induced changes observed in rats and, thus, will be highly useful to researchers that need to use this particular mouse strain as an animal model of neuropsychiatric disorders and/or immune deregulation related to chronic unpredictable stress.

  10. 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.

  11. Chronic stress from adolescence to aging in the prefrontal cortex: A neuroimmune perspective.

    Science.gov (United States)

    Macht, Victoria A; Reagan, Lawrence P

    2018-04-01

    The development of the organism is a critical variable which influences the magnitude, duration, and reversibility of the effects of chronic stress. Such factors are relevant to the prefrontal cortex (PFC), as this brain region is the last to mature, the first to decline, and is highly stress-sensitive. Therefore, this review will examine the intersection between the nervous system and immune system at glutamatergic synapses in the PFC across three developmental periods: adolescence, adulthood, and aging. Glutamatergic synapses are tightly juxtaposed with microglia and astrocytes, and each of these cell types exhibits their own developmental trajectory. Not only does chronic stress differentially impact each of these cell types across development, but chronic stress also alters intercellular communication within this quad-partite synapse. These observations suggest that developmental shifts in both neural and immune function across neurons, microglia, and astrocytes mediate shifting effects of chronic stress on glutamatergic transmission. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. 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.

  13. 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

  14. Posttraumatic stress disorder symptoms in youth with vs without chronic pain.

    Science.gov (United States)

    Noel, Melanie; Wilson, Anna C; Holley, Amy Lewandowski; Durkin, Lindsay; Patton, Michaela; Palermo, Tonya M

    2016-10-01

    Chronic pain and posttraumatic stress disorder (PTSD) symptoms have been found to co-occur in adults; however, research has not examined this co-occurrence in adolescence, when pediatric chronic pain often first emerges. The aims of this study were to compare the frequency and intensity of PTSD symptoms and stressful life events in cohorts of youth with (n = 95) and without (n = 100) chronic pain and their parents and to determine the association between PTSD symptoms, health-related quality of life, and pain symptoms within the chronic pain sample. All participants completed questionnaire measures through an online survey. Findings revealed that youth with chronic pain and their parents had significantly higher levels of PTSD symptoms as compared with pain-free peers. More youth with chronic pain (32%) and their parents (20%) reported clinically significant elevations in PTSD symptoms than youth without chronic pain (8%) and their parents (1%). Youth with chronic pain also reported a greater number of stressful life events than those without chronic pain, and this was associated with higher PTSD symptoms. Among the chronic pain cohort, higher levels of PTSD symptoms were predictive of worse health-related quality of life and were associated with higher pain intensity, unpleasantness, and interference. Results suggest that elevated PTSD symptoms are common and linked to reduced functioning among youth with chronic pain. Future research is needed to examine PTSD at the diagnostic level and the underlying mechanisms that may explain why this co-occurrence exists.

  15. 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.

  16. 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.

  17. The response of Asterochloris erici (Ahmadjian) Skaloud et Peksa to desiccation: a proteomic approach

    Science.gov (United States)

    The study of desiccation tolerance of lichens, and of their photobionts in particular, has frequently focused on the antioxidant system that protects the cell against photo-oxidative stress during dehydration/rehydration cycles. Thus, in this work we carried out proteomic and transcript analyses of ...

  18. Abscisic acid (ABA) sensitivity regulates desiccation tolerance in germinated Arabidopsis seeds

    NARCIS (Netherlands)

    Maia de Oliveira, J.; Dekkers, S.J.W.; Dolle, M.; Ligterink, W.; Hilhorst, H.W.M.

    2014-01-01

    During germination, orthodox seeds lose their desiccation tolerance (DT) and become sensitive to extreme drying. Yet, DT can be rescued, in a well-defined developmental window, by the application of a mild osmotic stress before dehydration. A role for abscisic acid (ABA) has been implicated in this

  19. Improved climatic chamber for desiccation simulation

    Directory of Open Access Journals (Sweden)

    Lozada Catalina

    2016-01-01

    Full Text Available The climatic chamber at the Universidad de Los Andes was improved for modeling desiccation in soil layers. This chamber allows the measurement of different environmental variables. In this research, evaporation tests were conducted in water imposing boundary conditions for drying, and then these tests were performed in a soil layer. The soil was prepared from a slurry state and was drying controlling the temperature, the infrared radiation, the wind velocity, and the relative humidity. In the first part of this paper, a description of the climatic chamber, operation ranges and theoretical work principles of the climatic chamber are presented. Then, the second part shows the results for desiccation in water and soil. The desiccation tests performed with the climatic chamber allow simulating all environmental conditions accurately during drying coupling the effect of all environmental variables. As a result, the evaporation rate increases with infrared radiation in soil and water. The rate at the beginning of the desiccation tests in clays is the same as in water. However, this evaporation rate decreases as the soil becomes desiccated.

  20. 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.

  1. 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.

  2. Chronic stress and illness in children: the role of allostatic load.

    Science.gov (United States)

    Johnston-Brooks, C H; Lewis, M A; Evans, G W; Whalen, C K

    1998-01-01

    Recent studies of stress have highlighted the contributions of chronic psychological and environmental stressors to health and well-being. Children may be especially vulnerable to the negative effects of chronic stressors. Allostasis, the body's ability to adapt and adjust to environmental demands, has been proposed as an explanatory mechanism for the stress-health link, yet empirical evidence is minimal. This study tested the proposition that allostasis may be an underlying physiological mechanism linking chronic stress to poor health outcomes in school-aged children. Specifically, we examined whether allostasis would mediate or moderate the link between chronic stress and health. To test the hypothesis that allostasis contributes to the relation between chronic stress and poor health, we examined household density as a chronic environmental stressor, cardiovascular reactivity (CVR) as a marker of allostatic load, and number of school absences due to illness as the health outcome in a sample of 81 boys. Structural equation modeling indicated that the mediating model fit the data well, accounting for 17% of the variance in days ill. Results provide the first evidence that CVR may mediate the relation between household density and medical illness in children. More generally, these findings support the role of allostasis as an underlying mechanism in the link between chronic stress and health.

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Quercetin prevents chronic unpredictable stress induced behavioral dysfunction in mice by alleviating hippocampal oxidative and inflammatory stress.

    Science.gov (United States)

    Mehta, Vineet; Parashar, Arun; Udayabanu, Malairaman

    2017-03-15

    It is now evident that chronic stress is associated with anxiety, depression and cognitive dysfunction and very few studies have focused on identifying possible methods to prevent these stress-induced disorders. Previously, we identified abundance of quercetin in Urtica dioica extract, which efficiently attenuated stress related complications. Therefore, current study was designed to investigate the effect of quercetin on chronic unpredicted stress (CUS) induced behavioral dysfunction, oxidative stress and neuroinflammation in the mouse hippocampus. Animals were subjected to unpredicted stress for 21days, during which 30mg/kg quercetin was orally administered to them. Effect of CUS and quercetin treatment on animal behavior was assessed between day 22-26. Afterward, the hippocampus was processed to evaluate neuronal damage, oxidative and inflammatory stress. Results revealed that stressed animals were highly anxious (Elevated Plus Maze and Open Field), showed depressive-like behavior (sucrose preference task), performed poorly in short-term and long-term associative memory task (passive avoidance step-through task) and displayed reduced locomotion (open field). Quercetin alleviated behavioral dysfunction in chronically stressed animals. Compared to CUS, quercetin treatment significantly reduced anxiety, attenuated depression, improved cognitive dysfunction and normalized locomotor activity. Further, CUS elevated the levels of oxidative stress markers (TBARS, nitric oxide), lowered antioxidants (total thiol, catalase), enhanced expression of pro-inflammatory cytokines (IL-6, TNF-α, IL-1β and COX-2) in the hippocampus and damaged hippocampal neurons. Quercetin treatment significantly lowered oxidative and inflammatory stress and prevented neural damage. In conclusion, quercetin can efficiently prevent stress induced neurological complications by rescuing brain from oxidative and inflammatory stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Pain Sensitivity Mediates The Relationship between Stress and Headache Intensity in Chronic Tension-Type Headache

    OpenAIRE

    Stuart Cathcart; Navjot Bhullar; Maarten Immink; Chris Della Vedova; John Hayball

    2012-01-01

    BACKGROUND: A central model for chronic tension-type headache (CTH) posits that stress contributes to headache, in part, by aggravating existing hyperalgesia in CTH sufferers. The prediction from this model that pain sensitivity mediates the relationship between stress and headache activity has not yet been examined.OBJECTIVE: To determine whether pain sensitivity mediates the relationship between stress and prospective headache activity in CTH sufferers.METHOD: Self-reported stress, pain sen...

  7. 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...

  8. In situ FTIR assessment of desiccation-tolerant tissues

    NARCIS (Netherlands)

    Wolkers, W.F.; Hoekstra, F.A.

    2003-01-01

    This essay shows how Fourier transform infrared (FTIR) microspectroscopy can be applied to study thermodynamic parameters and conformation of endogenous biomolecules in desiccation-tolerant biological tissues. Desiccation tolerance is the remarkable ability of some organisms to survive complete

  9. Influence of Chronic Stress and Oclusal Interference on Masseter Muscle Pain in Rat

    OpenAIRE

    Simonić-Kocijan, Sunčana; Uhač, Ivone; Braut, Vedrana; Kovač, Zoran; Kovačević Pavičić, Daniela; Fugošić, Vesna; Muhvić Urek, Miranda

    2009-01-01

    This study aimed to investigate the individual effects of chronic stress and occlusal interference, as well as their combined influence on masseter muscle pain. Experiments were performed on 28 male Wistar rats. Animals were submitted to chronic stress procedure, exposed to occlusal interference, or exposed to both mantioned procedures. At the end of the procedure animals were submitted to orofacial formalin test, and nociceptive behavioral response was evaluated. Statisticaly significant dif...

  10. An efficient chronic unpredictable stress protocol to induce stress-related responses in C57BL/6 mice.

    Science.gov (United States)

    Monteiro, Susana; Roque, Susana; de Sá-Calçada, Daniela; Sousa, Nuno; Correia-Neves, Margarida; Cerqueira, João José

    2015-01-01

    Exposure to chronic stress can have broad effects on health ranging from increased predisposition for neuropsychiatric disorders to deregulation of immune responses. The chronic unpredictable stress (CUS) protocol has been widely used to study the impact of stress exposure in several animal models and consists in the random, intermittent, and unpredictable exposure to a variety of stressors during several weeks. CUS has consistently been shown to induce behavioral and immunological alterations typical of the chronic stress-response. Unfortunately C57BL/6 mice, one of the most widely used mouse strains, due to the great variety of genetically modified lines, seem to be resistant to the commonly used 4-week-long CUS protocol. The definition of an alternative CUS protocol allowing the use of C57BL/6 mice in chronic stress experiments is a need. Here, we show that by extending the CUS protocol to 8 weeks is possible to induce a chronic stress-response in C57BL/6 mice, as revealed by abrogated body weight gain, increased adrenals weight, and an overactive hypothalamic-pituitary-adrenal axis with increased levels of serum corticosterone. Moreover, we also observed stress-associated behavioral alterations, including the potentiation of anxious-like and depressive-like behaviors and a reduction of exploratory behavior, as well as subtle stress-related changes in the cell population of the thymus and of the spleen. The present protocol for C57BL/6 mice consistently triggers the spectrum of CUS-induced changes observed in rats and, thus, will be highly useful to researchers that need to use this particular mouse strain as an animal model of neuropsychiatric disorders and/or immune deregulation related to CUS.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. Neurobiology of Chronic Stress-Related Psychiatric Disorders: Evidence from Molecular Imaging Studies

    Science.gov (United States)

    Davis, Margaret T.; Holmes, Sophie E.; Pietrzak, Robert H.; Esterlis, Irina

    2018-01-01

    Chronic stress accounts for billions of dollars of economic loss annually in the United States alone, and is recognized as a major source of disability and mortality worldwide. Robust evidence suggests that chronic stress plays a significant role in the onset of severe and impairing psychiatric conditions, including major depressive disorder, bipolar disorder, and posttraumatic stress disorder. Application of molecular imaging techniques such as positron emission tomography and single photon emission computed tomography in recent years has begun to provide insight into the molecular mechanisms by which chronic stress confers risk for these disorders. The present paper provides a comprehensive review and synthesis of all positron emission tomography and single photon emission computed tomography imaging publications focused on the examination of molecular targets in individuals with major depressive disorder, posttraumatic stress disorder, or bipolar disorder to date. Critical discussion of discrepant findings and broad strengths and weaknesses of the current body of literature is provided. Recommended future directions for the field of molecular imaging to further elucidate the neurobiological substrates of chronic stress-related disorders are also discussed. This article is part of the inaugural issue for the journal focused on various aspects of chronic stress. PMID:29862379

  17. 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.

  18. Are there associations between sleep bruxism, chronic stress, and sleep quality?

    Science.gov (United States)

    Ohlmann, Brigitte; Bömicke, Wolfgang; Habibi, Yasamin; Rammelsberg, Peter; Schmitter, Marc

    2018-07-01

    The purpose of this study was to identify associations between definite sleep bruxism, as defined by the American academy of sleep medicine, and chronic stress and sleep quality. Sleep bruxism was determined by use of questionnaires, assessment of clinical symptoms, and recording of electromyographic and electrocardiographic data (recorded by the Bruxoff ® device). The study included 67 participants. Of these, 38 were identified as bruxers and 29 as non-bruxers. The 38 bruxers were further classified as 17 moderate and 21 intense bruxers. Self-reported stress and self-reported sleep quality were determined by use of the validated questionnaires "Trier Inventory for the Assessment of Chronic Stress" (TICS) and the "Pittsburgh Sleep Quality Index" (PSQI). No statistically significant association was found between sleep bruxism and self-reported stress or sleep quality. However, a significant association between specific items of chronic stress and poor sleep quality was identified. The results of this study indicate an association between subjective sleep quality and subjective chronic stress, irrespective of the presence or absence of sleep bruxism. Chronic stress and sleep quality do not seem to be associated with sleep bruxism. (clinical trial no. NCT03039985). Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. 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

  20. Freezing and desiccation tolerance in entomopathogenic nematodes: diversity and correlation of traits.

    Science.gov (United States)

    Shapiro-Ilan, David I; Brown, Ian; Lewis, Edwin E

    2014-03-01

    The ability of entomopathogenic nematodes to tolerate environmental stress such as desiccating or freezing conditions, can contribute significantly to biocontrol efficacy. Thus, in selecting which nematode to use in a particular biocontrol program, it is important to be able to predict which strain or species to use in target areas where environmental stress is expected. Our objectives were to (i) compare inter- and intraspecific variation in freeze and desiccation tolerance among a broad array of entomopathogenic nematodes, and (ii) determine if freeze and desiccation tolerance are correlated. In laboratory studies we compared nematodes at two levels of relative humidity (RH) (97% and 85%) and exposure periods (24 and 48 h), and nematodes were exposed to freezing temperatures (-2°C) for 6 or 24 h. To assess interspecific variation, we compared ten species including seven that are of current or recent commercial interest: Heterorhabditis bacteriophora (VS), H. floridensis, H. georgiana, (Kesha), H. indica (HOM1), H. megidis (UK211), Steinernema carpocapsae (All), S. feltiae (SN), S. glaseri (VS), S. rarum (17C&E), and S. riobrave (355). To assess intraspecific variation we compared five strains of H. bacteriophora (Baine, Fl1-1, Hb, Oswego, and VS) and four strains of S. carpocapsae (All, Cxrd, DD136, and Sal), and S. riobrave (355, 38b, 7-12, and TP). S. carpocapsae exhibited the highest level of desiccation tolerance among species followed by S. feltiae and S. rarum; the heterorhabditid species exhibited the least desiccation tolerance and S. riobrave and S. glaseri were intermediate. No intraspecific variation was observed in desiccation tolerance; S. carpocapsae strains showed higher tolerance than all H. bacteriophora or S. riobrave strains yet there was no difference detected within species. In interspecies comparisons, poor freeze tolerance was observed in H. indica, and S. glaseri, S. rarum, and S. riobrave whereas H. georgiana and S. feltiae exhibited the

  1. 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.

  2. 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)

  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. 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/.

  5. Accelerated Aging during Chronic Oxidative Stress: A Role for PARP-1

    Directory of Open Access Journals (Sweden)

    Daniëlle M. P. H. J. Boesten

    2013-01-01

    Full Text Available Oxidative stress plays a major role in the pathophysiology of chronic inflammatory disease and it has also been linked to accelerated telomere shortening. Telomeres are specialized structures at the ends of linear chromosomes that protect these ends from degradation and fusion. Telomeres shorten with each cell division eventually leading to cellular senescence. Research has shown that poly(ADP-ribose polymerase-1 (PARP-1 and subtelomeric methylation play a role in telomere stability. We hypothesized that PARP-1 plays a role in accelerated aging in chronic inflammatory diseases due to its role as coactivator of NF-κb and AP-1. Therefore we evaluated the effect of chronic PARP-1 inhibition (by fisetin and minocycline in human fibroblasts (HF cultured under normal conditions and under conditions of chronic oxidative stress, induced by tert-butyl hydroperoxide (t-BHP. Results showed that PARP-1 inhibition under normal culturing conditions accelerated the rate of telomere shortening. However, under conditions of chronic oxidative stress, PARP-1 inhibition did not show accelerated telomere shortening. We also observed a strong correlation between telomere length and subtelomeric methylation status of HF cells. We conclude that chronic PARP-1 inhibition appears to be beneficial in conditions of chronic oxidative stress but may be detrimental under relatively normal conditions.

  6. Chronic mild stress influences nerve growth factor through a matrix metalloproteinase-dependent mechanism.

    Science.gov (United States)

    Kucharczyk, Mateusz; Kurek, Anna; Detka, Jan; Slusarczyk, Joanna; Papp, Mariusz; Tota, Katarzyna; Basta-Kaim, Agnieszka; Kubera, Marta; Lason, Wladyslaw; Budziszewska, Bogusława

    2016-04-01

    Stress is generally a beneficial experience that motivates an organism to action to overcome the stressful challenge. In particular situations, when stress becomes chronic might be harmful and devastating. The hypothalamus is a critical coordinator of stress and the metabolic response; therefore, disruptions in this structure may be a significant cause of the hormonal and metabolic disturbances observed in depression. Chronic stress induces adverse changes in the morphology of neural cells that are often associated with a deficiency of neurotrophic factors (NTFs); additionally, many studies indicate that insufficient NTF synthesis may participate in the pathogenesis of depression. The aim of the present study was to determine the expression of the nerve growth factor (NGF) in the hypothalamus of male rats subjected to chronic mild stress (CMS) or to prenatal stress (PS) and to PS in combination with an acute stress event (AS). It has been found that chronic mild stress, but not prenatal stress, acute stress or a combination of PS with AS, decreased the concentration of the mature form of NGF (m-NGF) in the rat hypothalamus. A discrepancy between an increase in the Ngf mRNA and a decrease in the m-NGF levels suggested that chronic mild stress inhibited NGF maturation or enhanced the degradation of this factor. We have shown that NGF degradation in the hypothalamus of rats subjected to chronic mild stress is matrix metalloproteinase-dependent and related to an increase in the active forms of some metalloproteinases (MMP), including MMP2, MMP3, MMP9 and MMP13, while the NGF maturation process does not seem to be changed. We suggested that activated MMP2 and MMP9 potently cleave the mature but not the pro- form of NGF into biologically inactive products, which is the reason for m-NGF decomposition. In turn, the enhanced expression of Ngf in the hypothalamus of these rats is an attempt to overcome the reduced levels of m-NGF. Additionally, the decreased level of m

  7. Parenting stress among caregivers of children with chronic illness: a systematic review.

    Science.gov (United States)

    Cousino, Melissa K; Hazen, Rebecca A

    2013-09-01

    To critically review, analyze, and synthesize the literature on parenting stress among caregivers of children with asthma, cancer, cystic fibrosis, diabetes, epilepsy, juvenile rheumatoid arthritis, and/or sickle cell disease. Method PsychInfo, MEDLINE, and Cumulative Index to Nursing and Allied Health Literature were searched according to inclusion criteria. Meta-analysis of 13 studies and qualitative analysis of 96 studies was conducted. Results Caregivers of children with chronic illness reported significantly greater general parenting stress than caregivers of healthy children (d = .40; p = ≤.0001). Qualitative analysis revealed that greater general parenting stress was associated with greater parental responsibility for treatment management and was unrelated to illness duration and severity across illness populations. Greater parenting stress was associated with poorer psychological adjustment in caregivers and children with chronic illness. Conclusion Parenting stress is an important target for future intervention. General and illness-specific measures of parenting stress should be used in future studies.

  8. Chronic Stress in Young German Adults: Who Is Affected? A Prospective Cohort Study

    OpenAIRE

    Herrera, Ronald; Berger, Ursula; Genuneit, Jon; Gerlich, Jessica; Nowak, Dennis; Schlotz, Wolff; Vogelberg, Christian; Mutius, Erika von; Weinmayr, Gudrun; Windstetter, Doris; Weigl, Matthias; Radon, Katja

    2017-01-01

    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, soc...

  9. Association between endothelial dysfunction and depression-like symptoms in chronic mild stress model of depression

    DEFF Research Database (Denmark)

    Bouzinova, Elena; Bødtkjer, Donna Marie Briggs; Kudryavtseva, Olga

    2014-01-01

    OBJECTIVE: Cardiovascular diseases have high comorbidity with major depression. Endothelial dysfunction may explain the adverse cardiovascular outcome in depression; therefore, we analyzed it in vitro. In the chronic mild stress model, some rats develop depression-like symptoms (including...... "anhedonia"), whereas others are stress resilient. METHODS: After 8 weeks of chronic mild stress, anhedonic rats reduced their sucrose intake by 55% (7%), whereas resilient rats did not. Acetylcholine-induced endothelium-dependent relaxation of norepinephrine-preconstricted mesenteric arteries was analyzed......-like response) was reduced in anhedonic rats (p depression-like symptoms are associated with reduced endothelium-dependent relaxation due to suppressed...

  10. Preventive and therapeutic effect of treadmill running on chronic stress-induced memory deficit in rats.

    Science.gov (United States)

    Radahmadi, Maryam; Alaei, Hojjatallah; Sharifi, Mohammad Reza; Hosseini, Nasrin

    2015-04-01

    Previous results indicated that stress impairs learning and memory. In this research, the effects of preventive, therapeutic and regular continually running activity on chronic stress-induced memory deficit in rats were investigated. 70 male rats were randomly divided into seven groups as follows: Control, Sham, Stress-Rest, Rest-Stress, Stress-Exercise, Exercise-Stress and Exercise-Stress & Exercise groups. Chronic restraint stress was applied 6 h/day for 21days and treadmill running 1 h/day. Memory function was evaluated by the passive avoidance test. The results revealed that running activities had therapeutic effect on mid and long-term memory deficit and preventive effects on short and mid-term memory deficit in stressed rats. Regular continually running activity improved mid and long-term memory compared to Exercise-Stress group. The beneficial effects of exercise were time-dependent in stress conditions. Finally, data corresponded to the possibility that treadmill running had a more important role on treatment rather than on prevention on memory impairment induced by stress. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Hope and fatigue in chronic illness: The role of perceived stress.

    Science.gov (United States)

    Hirsch, Jameson K; Sirois, Fuschia M

    2016-04-01

    Fatigue is a debilitating symptom of chronic illness that is deleteriously affected by perceived stress, a process particularly relevant to inflammatory disease. Hopefulness, a goal-based motivational construct, may beneficially influence stress and fatigue, yet little research has examined these associations. We assessed the relation between hope and fatigue, and the mediating effect of stress, in individuals with fibromyalgia, arthritis, and inflammatory bowel disease. Covarying age, sex, and pain, stress partially mediated the association between hope and fatigue; those with greater hope reported less stress and consequent fatigue. Therapeutically, bolstering hope may allow proactive management of stressors, resulting in less fatigue. © The Author(s) 2014.

  12. Agmatine attenuates chronic unpredictable mild stress induced behavioral alteration in mice.

    Science.gov (United States)

    Taksande, Brijesh G; Faldu, Dharmesh S; Dixit, Madhura P; Sakaria, Jay N; Aglawe, Manish M; Umekar, Milind J; Kotagale, Nandkishor R

    2013-11-15

    Chronic stress exposure and resulting dysregulation of the hypothalamic pituitary adrenal axis develops susceptibility to variety of neurological and psychiatric disorders. Agmatine, a putative neurotransmitter has been reported to be released in response to various stressful stimuli to maintain the homeostasis. Present study investigated the role of agmatine on chronic unpredictable mild stress (CUMS) induced behavioral and biochemical alteration in mice. Exposure of mice to CUMS protocol for 28 days resulted in diminished performance in sucrose preference test, splash test, forced swim test and marked elevation in plasma corticosterone levels. Chronic agmatine (5 and 10 mg/kg, ip, once daily) treatment started on day-15 and continued till the end of the CUMS protocol significantly increased sucrose preference, improved self-care and motivational behavior in the splash test and decreased duration of immobility in the forced swim test. Agmatine treatment also normalized the elevated corticosterone levels and prevented the body weight changes in chronically stressed animals. The pharmacological effect of agmatine was comparable to selective serotonin reuptake inhibitor, fluoxetine (10mg/kg, ip). Results of present study clearly demonstrated the anti-depressant like effect of agmatine in chronic unpredictable mild stress induced depression in mice. Thus the development of drugs based on brain agmatinergic modulation may represent a new potential approach for the treatment of stress related mood disorders like depression. © 2013 Published by Elsevier B.V.

  13. Lithium modulates the chronic stress-induced effect on blood glucose level of male rats

    Directory of Open Access Journals (Sweden)

    Popović Nataša

    2010-01-01

    Full Text Available In the present study we examined gross changes in the mass of whole adrenal glands and that of the adrenal cortex, as well as the serum corticosterone and glucose level of mature male Wistar rats subjected to three different treatments: animals subjected to chronic restraint-stress, animals injected with lithium (Li and chronically stressed rats treated with Li. Under all three conditions we observed hypertrophy of whole adrenals, as well as the adrenal cortices. Chronic restraint stress, solely or in combination with Li treatment, significantly elevated the corticosterone level, but did not change the blood glucose level. Animals treated only with Li exhibited an elevated serum corticosterone level and blood glucose level. The aim of our study was to investigate the modulation of the chronic stress-induced effect on the blood glucose level by lithium, as a possible mechanism of avoiding the damage caused by chronic stress. Our results showed that lithium is an agent of choice which may help to reduce stress-elevated corticosterone and replenish exhausted glucose storages in an organism.

  14. 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...

  15. 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

  16. 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

  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. A realistic appraisal of methods to enhance desiccation tolerance of entomopathogenic nematodes.

    Science.gov (United States)

    Perry, Roland N; Ehlers, Ralf-Udo; Glazer, Itamar

    2012-06-01

    Understanding the desiccation survival attributes of infective juveniles of entomopathogenic nematodes (EPN) of the genera Steinernema and Heterorhabditis, is central to evaluating the reality of enhancing the shelf-life and field persistence of commercial formulations. Early work on the structural and physiological aspects of desiccation survival focused on the role of the molted cuticle in controlling the rate of water loss and the importance of energy reserves, particularly neutral lipids. The accumulation of trehalose was also found to enhance desiccation survival. Isolation of natural populations that can survive harsh environments, such as deserts, indicated that some populations have enhanced abilities to survive desiccation. However, survival abilities of EPN are limited compared with those of some species of plant-parasitic nematodes inhabiting aerial parts of plants. Research on EPN stress tolerance has expanded on two main lines: i) to select strains of species, currently in use commercially, which have increased tolerance to environmental extremes; and ii) to utilize molecular information, including expressed sequence tags and genome sequence data, to determine the underlying genetic factors that control longevity and stress tolerance of EPN. However, given the inherent limitations of EPN survival ability, it is likely that improved formulation will be the major factor to enhance EPN longevity and, perhaps, increase the range of applications.

  19. 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

    The work that constitutes this Final Addendum Report derived from the hypothesis that individual differences in stress reactivity derived from selective breeding generalize to a behavioral phenotype...

  20. 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

  1. Influence of chronic stress and oclusal interference on masseter muscle pain in rat.

    Science.gov (United States)

    Simonić-Kocijan, Suncana; Uhac, Ivone; Braut, Vedrana; Kovac, Zoran; Pavicić, Daniela Kovacević; Fugosić, Vesna; Urek, Miranda Muhvić

    2009-09-01

    This study aimed to investigate the individual effects of chronic stress and occlusal interference, as well as their combined influence on masseter muscle pain. Experiments were performed on 28 male Wistar rats. Animals were submitted to chronic stress procedure, exposed to occlusal interference, or exposed to both mantioned procedures. At the end of the procedure animals were submitted to orofacial formalin test, and nociceptive behavioral response was evaluated. Statisticaly significant difference of nociceptive behavioral response in chronicaly stressed rats and in the animals with occlusal interference in comparation to the control group were not obtained (p > 0.05). In contrast, nociceptive behavioral response was significantly increased in rats submitted to both of experimental procedures (p occlusal interference and chronic stress influence masseter muscle pain.

  2. 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.

  3. 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.

  4. Chronic stress and coping among cardiac surgeons: a single center study

    Directory of Open Access Journals (Sweden)

    Kyriakos Spiliopoulos

    2014-09-01

    Full Text Available Introduction: Cardiac surgeons stress may impair their quality of life and professional practice. Objective: To assess perceived chronic stress and coping strategies among cardiac surgeons. Methods: Twenty-two cardiac surgeons answered two self-assessment questionnaires, the Trier Inventory for Chronic Stress and the German SGV for coping strategies. Results: Participants mean age was 40±14.1 years and 13 were male; eight were senior physicians and 14 were residents. Mean values for the Trier Inventory for Chronic Stress were within the normal range. Unexperienced physicians had significantly higher levels of dissatisfaction at work, lack of social recognition, and isolation (P<0.05. Coping strategies such as play down, distraction from situation, and substitutional satisfaction were also significantly more frequent among unexperienced surgeons. "Negative" stress-coping strategies occur more often in experienced than in younger colleagues (P=0.029. Female surgeons felt more exposed to overwork (P=0.04 and social stress (P=0.03. Conclusion: Cardiac surgeons show a tendency to high perception of chronic stress phenomena and vulnerability for negative coping strategies.

  5. A Presence-Based Context-Aware Chronic Stress Recognition System

    Directory of Open Access Journals (Sweden)

    Andrej Kos

    2012-11-01

    Full Text Available Stressors encountered in daily life may play an important role in personal well-being. Chronic stress can have a serious long-term impact on our physical as well as our psychological health, due to ongoing increased levels of the chemicals released in the ‘fight or flight’ response. The currently available stress assessment methods are usually not suitable for daily chronic stress measurement. The paper presents a context-aware chronic stress recognition system that addresses this problem. The proposed system obtains contextual data from various mobile sensors and other external sources in order to calculate the impact of ongoing stress. By identifying and visualizing ongoing stress situations of an individual user, he/she is able to modify his/her behavior in order to successfully avoid them. Clinical evaluation of the proposed methodology has been made in parallel by using electrodermal activity sensor. To the best of our knowledge, the system presented herein is the first one that enables recognition of chronic stress situations on the basis of user context.

  6. 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.…

  7. 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....

  8. 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 ...

  9. Stress and sleep duration predict headache severity in chronic headache sufferers.

    Science.gov (United States)

    Houle, Timothy T; Butschek, Ross A; Turner, Dana P; Smitherman, Todd A; Rains, Jeanetta C; Penzien, Donald B

    2012-12-01

    The objective of this study was to evaluate the time-series relationships between stress, sleep duration, and headache pain among patients with chronic headaches. Sleep and stress have long been recognized as potential triggers of episodic headache (headache days/month), though prospective evidence is inconsistent and absent in patients diagnosed with chronic headaches (≥15 days/month). We reanalyzed data from a 28-day observational study of chronic migraine (n=33) and chronic tension-type headache (n=22) sufferers. Patients completed the Daily Stress Inventory and recorded headache and sleep variables using a daily sleep/headache diary. Stress ratings, duration of previous nights' sleep, and headache severity were modeled using a series of linear mixed models with random effects to account for individual differences in observed associations. Models were displayed using contour plots. Two consecutive days of either high stress or low sleep were strongly predictive of headache, whereas 2 days of low stress or adequate sleep were protective. When patterns of stress or sleep were divergent across days, headache risk was increased only when the earlier day was characterized by high stress or poor sleep. As predicted, headache activity in the combined model was highest when high stress and low sleep occurred concurrently during the prior 2 days, denoting an additive effect. Future research is needed to expand on current findings among chronic headache patients and to develop individualized models that account for multiple simultaneous influences of headache trigger factors. Copyright © 2012 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  10. Anhedonia but not passive floating is an indicator of depressive-like behavior in two chronic stress paradigms.

    Science.gov (United States)

    Stepanichev, Mikhail Yu; Tishkina, Anna O; Novikova, Margarita R; Levshina, Irina P; Freiman, Sofiya V; Onufriev, Mikhail V; Levchenko, Olga A; Lazareva, Natalia A; Gulyaeva, Natalia V

    2016-01-01

    Depression is the most common form of mental disability in the world. Depressive episodes may be precipitated by severe acute stressful events or by mild chronic stressors. Studies on the mechanisms of depression require both appropriate experimental models (most of them based on the exposure of animals to chronic stressors), and appropriate tests for assessment of depressive states. In this study male Wistar rats were exposed to two different chronic stress paradigms: an eight-week chronic unpredictable mild stress or a two-week combined chronic stress. The behavioral effects of stress were evaluated using sucrose preference, forced swim and open field tests. After the exposure to chronic unpredictable mild stress, anhedonia was developed, activity in the open field increased, while no changes in the duration of passive floating could be detected. After chronic combined stress, anhedonia was also evident, whereas behavior in the open field and forced swim test did not change. The levels of corticosterone in the blood and brain structures involved in stress-response did not differ from control in both experiments. The absence of significant changes in corticosterone levels and passive floating may be indicative of the adaptation of animals to chronic stress. Anhedonia appears to be a more sensitive indicator of depressive-like behavioral effects of chronic stress as compared to behavior in the forced swim or open field tests.

  11. Occurrence of hypermutable Pseudomonas aeruginosa in cystic fibrosis patients is associated with the oxidative stress caused by chronic lung inflammation

    DEFF Research Database (Denmark)

    Ciofu, Oana; Riis, Bente; Pressler, Tacjana

    2005-01-01

    Oxidative stress caused by chronic lung inflammation in patients with cystic fibrosis (CF) and chronic lung infection with Pseudomonas aeruginosa is characterized by the reactive oxygen species (ROS) liberated by polymorphonuclear leukocytes (PMNs). We formulated the hypothesis that oxidation...

  12. Decreased MORF leads to prolonged endoplasmic reticulum stress in periodontitis-associated chronic inflammation.

    Science.gov (United States)

    Xue, Peng; Li, Bei; An, Ying; Sun, Jin; He, Xiaoning; Hou, Rui; Dong, Guangying; Fei, Dongdong; Jin, Fang; Wang, Qintao; Jin, Yan

    2016-11-01

    The association between inflammation and endoplasmic reticulum (ER) stress has been described in many diseases. However, if and how chronic inflammation governs the unfolded protein response (UPR) and promotes ER homeostasis of chronic inflammatory disease remains elusive. In this study, chronic inflammation resulted in ER stress in mesenchymal stem cells in the setting of periodontitis. Long-term proinflammatory cytokines induced prolonged ER stress and decreased the osteogenic differentiation of periodontal ligament stem cells (PDLSCs). Interestingly, we showed that chronic inflammation decreases the expression of lysine acetyltransferase 6B (KAT6B, also called MORF), a histone acetyltransferase, and causes the upregulation of a key UPR sensor, PERK, which lead to the persistent activation of the UPR in PDLSCs. Furthermore, we found that the activation of UPR mediated by MORF in chronic inflammation contributes to the PERK-related deterioration of the osteogenic differentiation of PDLSCs both in vivo and in vitro. Taken together, our results suggest that chronic inflammation compromises UPR function through MORF-mediated-PERK transcription, which is a previously unrecognized mechanism that contributes to impaired ER function, prolonged ER stress and defective osteogenic differentiation of PDLSCs in periodontitis.

  13. [Damage effects of chronic hypoxia on medulla oblongata associated with oxidative stress and cell apoptosis].

    Science.gov (United States)

    Hou, Xuefei; Ding, Yan; Nie, Zheng; Li, Hui; Tang, Yuhong; Zhou, Hua; Chen, Li; Zheng, Yu

    2012-08-01

    The aim of this study is to study the damage effects of chronic hypoxia on medulla oblongata and to explore whether the damage is associated with oxidative stress and cell apoptosis. Adult male SD rats were randomly divided into two groups: control group and chronic hypoxia group. Medulla oblongata was obtained for the following methods of analyses. Nissl's staining was used to examine the Niss bodies of neurons in medullary respiratory related nuclei, biochemistry methods were utilized to examine oxidant stress damage induced by chronic hypoxia on medulla oblongata through measuring malondialdehyde (MDA) content and superoxide dismutase (SOD) activity, and RT-PCR technique was used to study the influence of apoptosis induced by chronic hypoxia on medulla oblongata through analyzing the levels of Bax mRNA and Bcl-2 mRNA. The results showed the optical densities of Nissl's staining in pre-BötC, NA, NTS, FN, and 12N were significantly decreased in chronic hypoxia group in comparison with that in control group (P 0.05). Bax mRNA expression had no obvious change and Bcl-2 mRNA expression significantly decreased in chronic hypoxia group in comparison with that in control group (P < 0.05). The results suggest that chronic hypoxia could bring about serious damage to medullary respiratory centers through aggravating oxidative stress and increasing cell apoptosis.

  14. 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.

  15. Effects of fluoxetine on changes of pain sensitivity in chronic stress model rats.

    Science.gov (United States)

    Lian, Yan-Na; Chang, Jin-Long; Lu, Qi; Wang, Yi; Zhang, Ying; Zhang, Feng-Min

    2017-06-09

    Exposure to stress could facilitate or inhibit pain responses (stress-induced hyperalgesia or hypoalgesia, respectively). Fluoxetine is a selective serotonin (5-HT) reuptake inhibitor antidepressant. There have been contradictory reports on whether fluoxetine produces antinociceptive effects. The purpose of this study was to elucidate changes in pain sensitivity after chronic stress exposure, and the effects of fluoxetine on these changes. We measured thermal, mechanical, and formalin-induced acute and inflammatory pain by using the tail-flick, von Frey, and formalin tests respectively. The results showed that rats exposed to chronic stress exhibited thermal and formalin-induced acute and inflammatory hypoalgesia and transient mechanical hyperalgesia. Furthermore, fluoxetine promoted hypoalgesia in thermal and inflammatory pain and induced mechanical hyperalgesia. Our results indicate that the 5-HT system could be involved in hypoalgesia of thermal and inflammatory pain and induce transient mechanical hyperalgesia after stress exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Educators' emotion regulation strategies and their physiological indicators of chronic stress over 1 year.

    Science.gov (United States)

    Katz, Deirdre A; Harris, Alexis; Abenavoli, Rachel; Greenberg, Mark T; Jennings, Patricia A

    2018-04-01

    Studies show teaching is a highly stressful profession and that chronic work stress is associated with adverse health outcomes. This study analysed physiological markers of stress and self-reported emotion regulation strategies in a group of middle school teachers over 1 year. Chronic physiological stress was assessed with diurnal cortisol measures at three time points over 1 year (fall, spring, fall). The aim of this longitudinal study was to investigate the changes in educators' physiological level of stress. Results indicate that compared to those in the fall, cortisol awakening responses were blunted in the spring. Further, this effect was ameliorated by the summer break. Additionally, self-reported use of the emotion regulation strategy reappraisal buffered the observed blunting that occurred in the spring. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Chronic stress as a factor in aircraft mishaps

    Science.gov (United States)

    Alkov, Robert A.

    1988-01-01

    Naval aviation is an unusually stressful career because of the inherent demands of the work. Stress is recognized as a cause of mishaps which involve pilot error. A questionnaire was adapted from Rahe and Homes' list of stressful life events in order to determine the relationship between pilot behavioral, personality, and life change factors on the one hand and responsibility for accidents on the other. A number of factors regarding interpersonal relationships, changes in personal behavior, personality factors, and life changes were found to discriminate between pilots who were and were not at fault in accidents.

  18. Intrinsic and extrinsic apoptotic pathways are involved in rat testis by cold water immersion-induced acute and chronic stress.

    Science.gov (United States)

    Juárez-Rojas, Adriana Lizbeth; García-Lorenzana, Mario; Aragón-Martínez, Andrés; Gómez-Quiroz, Luis Enrique; Retana-Márquez, María del Socorro

    2015-01-01

    Testicular apoptosis is activated by stress, but it is not clear which signaling pathway is activated in response to stress. The aim of this study was to investigate whether intrinsic, extrinsic, or both apoptotic signaling pathways are activated by acute and chronic stress. Adult male rats were subjected to cold water immersion-induced stress for 1, 20, 40, and 50 consecutive days. The seminiferous tubules:apoptotic cell ratio was assayed on acute (1 day) and chronic (20, 40, 50 days) stress. Apoptotic markers, including cleaved-caspase 3 and 8, the pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins were also determined after acute and chronic stress induction. Additionally, epididymal sperm quality was evaluated, as well as corticosterone and testosterone levels. An increase in tubule apoptotic cell count percentage after an hour of acute stress and during chronic stress induction was observed. The apoptotic cells rate per tubule increment was only detected one hour after acute stress, but not with chronic stress. Accordingly, there was an increase in Bax, cleaved caspase-8 and caspase-3 pro-apoptotic proteins with a decrease of anti-apoptotic Bcl-2 in both acutely and chronically stressed male testes. In addition, sperm count, viability, as well as total and progressive motility were low in chronically stressed males. Finally, the levels of corticosterone increased whereas testosterone levels decreased in chronically stressed males. Activation of the extrinsic apoptotic pathway was shown by cleaved caspase-8 increase whereas the intrinsic apoptotic pathway activation was determined by the increase of Bax, along with Bcl-2 decrease, making evident a cross-talk between these two pathways with the activation of caspase-3. These results suggest that both acute and chronic stress can potentially activate the intrinsic/extrinsic apoptosis pathways in testes. Chronic stress also reduces the quality of epididymal spermatozoa, possibly due to a decrease in testosterone.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Role of insular cortex in visceral hypersensitivity model in rats subjected to chronic stress.

    Science.gov (United States)

    Yi, LiSha; Sun, HuiHui; Ge, Chao; Chen, Ying; Peng, HaiXia; Jiang, YuanXi; Wu, Ping; Tang, YinHan; Meng, QingWei; Xu, ShuChang

    2014-12-30

    Abnormal processing of visceral sensation at the level of the central nervous system has been proven to be important in the pathophysiologic mechanisms of stress related functional gastrointestinal disorders. However, the specific mechanism is still not clear. The insular cortex (IC) was considered as one important visceral sensory area. Moreover, the IC has been shown to be involved in various neuropsychiatric diseases such as panic disorders and post-traumatic stress disorder. However, whether the IC is important in psychological stress related visceral hypersensitivity has not been studied yet. In our study, through destruction of the bilateral IC, we explored whether the IC played a critical role in the formation of visceral hypersensitivity induced by chronic stress on rats. Chronic partial restraint stress was used to establish viscerally hypersensitive rat model. Bilateral IC lesions were generated by N-methyl-D-day (door) aspartate. After a recovery period of 7 days, 14-day consecutive restraint stress was performed. The visceromotor response to colorectal distension was monitored by recording electromyogram to measure rats׳ visceral sensitivity. We found that bilateral insular cortex lesion could markedly inhibit the formation of visceral hypersensitivity induced by chronic stress. The insular cortex plays a critical role in the pathophysiology of stress-related visceral hypersensitivity.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. 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...

  3. An aberrant parasympathetic response: a new perspective linking chronic stress and itch.

    Science.gov (United States)

    Kim, Hei Sung; Yosipovitch, Gil

    2013-04-01

    Perceived stress has long been known to alter the dynamic equilibrium established between the nervous, endocrine and immune system and is widely recognised to trigger or enhance pruritus. However, the exact mechanism of how the major stress response systems, such as the hypothalamus-pituitary adrenal (HPA) axis and the autonomic nervous system induce or aggravate chronic itch, has not been elucidated. The limbic regions of the brain such as the prefrontal cortex and hippocampus are deeply involved in the regulation of the stress response and intersect with circuits that are responsible for memory and reward. According to the 'Polyvagal Theory', certain limbic structures that serve as a 'higher brain equivalent of the parasympathetic nervous system' play a foremost role in maintaining body homoeostasis by functioning as an active vagal brake. In addition, the limbic system has been postulated to regulate two distinct, yet related aspects of itch: (i) the sensory-discriminative aspect; and (ii) the affective-cognitive aspect. Chronic stress-induced itch is hypothesised to be caused by stress-related changes in limbic structure with subsequent rewiring of both the peripheral and central pruriceptive circuits. Herein, we review data suggesting that a dysfunctional parasympathetic nervous system associated with chronic stress may play a critical role in the regulatory control of key candidate molecules, receptors and brain structures involved in chronic itch. © 2012 John Wiley & Sons A/S.

  4. 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.

  5. 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.

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

    Science.gov (United States)

    2014-10-15

    of oxidative stress in atherosclerosis. American of Journal in Cardiology , 91, 7A–11A. 11. Balkaya, M., Prinz, V., Custodis, F., et al. (2011...femoral artery occlusion (Figs. 2 and 5). Fig. 2 Blood flow recovery measurement after FAL. Blood flow mea- sured for control ( open circle) and stressed...peripheral arterial disease. Journal General and International Medication, 18(6), 461–467. 5. Yan, L. L., Liu, K., Matthews, K. A., et al. (2003). Psychosocial

  7. Chronic stress may facilitate the recruitment of habit- and addiction-related neurocircuitries through neuronal restructuring of the striatum.

    Science.gov (United States)

    Taylor, S B; Anglin, J M; Paode, P R; Riggert, A G; Olive, M F; Conrad, C D

    2014-11-07

    Chronic stress is an established risk factor in the development of addiction. Addiction is characterized by a progressive transition from casual drug use to habitual and compulsive drug use. The ability of chronic stress to facilitate the transition to addiction may be mediated by increased engagement of the neurocircuitries underlying habitual behavior and addiction. In the present study, striatal morphology was evaluated after 2 weeks of chronic variable stress in male Sprague-Dawley rats. Dendritic complexity of medium spiny neurons was visualized and quantified with Golgi staining in the dorsolateral and dorsomedial striatum, as well as in the nucleus accumbens core and shell. In separate cohorts, the effects of chronic stress on habitual behavior and the acute locomotor response to methamphetamine were also assessed. Chronic stress resulted in increased dendritic complexity in the dorsolateral striatum and nucleus accumbens core, regions implicated in habitual behavior and addiction, while decreased complexity was found in the nucleus accumbens shell, a region critical for the initial rewarding effects of drugs of abuse. Chronic stress did not affect dendritic complexity in the dorsomedial striatum. A parallel shift toward habitual learning strategies following chronic stress was also identified. There was an initial reduction in acute locomotor response to methamphetamine, but no lasting effect as a result of chronic stress exposure. These findings suggest that chronic stress may facilitate the recruitment of habit- and addiction-related neurocircuitries through neuronal restructuring in the striatum. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  8. Chronic daily headache: stress and impact on the quality of life.

    Science.gov (United States)

    Galego, José Carlos Busto; Moraes, Avelina Maria; Cordeiro, José Antonio; Tognola, Waldir Antonio

    2007-12-01

    To evaluate the stress presence and its influence in the quality of life of patients with chronic daily headache (CDH). A hundred patients with at least 18 years old, with primary headache with duration greater than 4 hours a day, and frequency of 15 or more days monthly for at least three months were studied. Lipp's Inventory of Stress Symptoms and the Medical Outcomes Study Short Form (SF-36) were used. Stress was observed in 90% of the patients; nearly half of them was in the phase almost exhaustion. Patients with stress when compared with the ones with no stress presented significantly lower scores in all the domains of SF-36; except in physical functioning. The resistance phase presented scores significantly higher than almost exhaustion; except for bodily pain. The majority of the patients presented stress with significant reduction in their quality of life. Consequently, the stress could be related with both the development and the maintenance of CDH.

  9. Pain sensitivity mediates the relationship between stress and headache intensity in chronic tension-type headache.

    Science.gov (United States)

    Cathcart, Stuart; Bhullar, Navjot; Immink, Maarten; Della Vedova, Chris; Hayball, John

    2012-01-01

    A central model for chronic tension-type headache (CTH) posits that stress contributes to headache, in part, by aggravating existing hyperalgesia in CTH sufferers. The prediction from this model that pain sensitivity mediates the relationship between stress and headache activity has not yet been examined. To determine whether pain sensitivity mediates the relationship between stress and prospective headache activity in CTH sufferers. Self-reported stress, pain sensitivity and prospective headache activity were measured in 53 CTH sufferers recruited from the general population. Pain sensitivity was modelled as a mediator between stress and headache activity, and tested using a nonparametric bootstrap analysis. Pain sensitivity significantly mediated the relationship between stress and headache intensity. The results of the present study support the central model for CTH, which posits that stress contributes to headache, in part, by aggravating existing hyperalgesia in CTH sufferers. Implications for the mechanisms and treatment of CTH are discussed.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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.

  17. 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...

  18. 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

  19. [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.

  20. Chronic and acute effects of stress on energy balance: are there appropriate animal models?

    Science.gov (United States)

    Harris, Ruth B S

    2015-02-15

    Stress activates multiple neural and endocrine systems to allow an animal to respond to and survive in a threatening environment. The corticotropin-releasing factor system is a primary initiator of this integrated response, which includes activation of the sympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis. The energetic response to acute stress is determined by the nature and severity of the stressor, but a typical response to an acute stressor is inhibition of food intake, increased heat production, and increased activity with sustained changes in body weight, behavior, and HPA reactivity. The effect of chronic psychological stress is more variable. In humans, chronic stress may cause weight gain in restrained eaters who show increased HPA reactivity to acute stress. This phenotype is difficult to replicate in rodent models where chronic psychological stress is more likely to cause weight loss than weight gain. An exception may be hamsters subjected to repeated bouts of social defeat or foot shock, but the data are limited. Recent reports on the food intake and body composition of subordinate members of group-housed female monkeys indicate that these animals have a similar phenotype to human stress-induced eaters, but there are a limited number of investigators with access to the model. Few stress experiments focus on energy balance, but more information on the phenotype of both humans and animal models during and after exposure to acute or chronic stress may provide novel insight into mechanisms that normally control body weight. Copyright © 2015 the American Physiological Society.

  1. Acute and chronic stress and the inflammatory response in hyperprolactinemic rats.

    Science.gov (United States)

    Ochoa-Amaya, J E; Malucelli, B E; Cruz-Casallas, P E; Nasello, A G; Felicio, L F; Carvalho-Freitas, M I R

    2010-01-01

    Prolactin (PRL), a hormone produced by the pituitary gland, has multiple physiological functions, including immunoregulation. PRL can also be secreted in response to stressful stimuli. During stress, PRL has been suggested to oppose the immunosuppressive effects of inflammatory mediators. Therefore, the aim of the present study was to analyze the effects of short- and long-term hyperprolactinemia on the inflammatory response in rats subjected to acute or chronic cold stress. Inflammatory edema was induced by carrageenan in male rats, and hyperprolactinemia was induced by injections of the dopamine receptor antagonist domperidone. The volume of inflammatory edema was measured by plethysmography after carrageenan injection. Additionally, the effects of hyperprolactinemia on body weight and serum corticosterone levels were evaluated. Five days of domperidone-induced hyperprolactinemia increased the volume of inflammatory edema. No differences in serum corticosterone levels were observed between groups. No significant differences were found among 30 days domperidone-induced hyperprolactinemic animals subjected to acute stress and the inflammatory response observed in chronic hyperprolactinemic animals subjected to chronic stress. The results suggest that short-term hyperprolactinemia has pro-inflammatory effects. Because such an effect was not observed in long-term hyperprolactinemic animals, PRL-induced tolerance seems likely. We suggest that short-term hyperprolactinemia may act as a protective factor in rats subjected to acute stress. These data suggest that hyperprolactinemia and stress interact differentially according to the time period. Copyright 2010 S. Karger AG, Basel.

  2. 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)

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. ProBDNF Signaling Regulates Depression-Like Behaviors in Rodents under Chronic Stress.

    Science.gov (United States)

    Bai, Yin-Yin; Ruan, Chun-Sheng; Yang, Chun-Rui; Li, Jia-Yi; Kang, Zhi-Long; Zhou, Li; Liu, Dennis; Zeng, Yue-Qing; Wang, Ting-Hua; Tian, Chang-Fu; Liao, Hong; Bobrovskaya, Larisa; Zhou, Xin-Fu

    2016-11-01

    Chronic exposure to stressful environment is a key risk factor contributing to the development of depression. However, the mechanisms involved in this process are still unclear. Brain-derived neurotropic factor (BDNF) has long been investigated for its positive role in regulation of mood, although the role of its precursor, proBDNF, in regulation of mood is not known. In this study, using an unpredictable chronic mild stress (UCMS) paradigm we found that the protein levels of proBDNF were increased in the neocortex and hippocampus of stressed mice and this UCMS-induced upregulation of proBDNF was abolished by chronic administration of fluoxetine. We then established a rat model of UCMS and found that the expression of proBDNF/p75 NTR /sortilin was upregulated, whereas the expression of mature BDNF and TrkB was downregulated in both neocortex and hippocampus of chronically stressed rats. Finally, we found that the injection of anti-proBDNF antibody via intracerebroventricular (i.c.v.) and intraperitoneal (i.p.) approaches into the UCMS rats significantly reversed the stress-induced depression-like behavior and restored the exploratory activity and spine growth. Although intramuscular injection of AAV-proBDNF did not exacerbate the UCMS-elicited rat mood-related behavioral or pathological abnormalities, i.c.v. injection of AAV-proBDNF increased the depression-like behavior in naive rats. Our findings suggest that proBDNF plays a role in the development of chronic stress-induced mood disturbances in rodents. Central (i.c.v.) or peripheral (i.p.) inhibition of proBDNF by injecting specific anti-proBDNF antibodies may provide a novel therapeutic approach for the treatment of stress-related mood disorders.

  8. Chronic traumatic stress impairs memory in mice: Potential roles of acetylcholine, neuroinflammation and corticotropin releasing factor expression in the hippocampus.

    Science.gov (United States)

    Bhakta, Ami; Gavini, Kartheek; Yang, Euitaek; Lyman-Henley, Lani; Parameshwaran, Kodeeswaran

    2017-09-29

    Chronic stress in humans can result in multiple adverse psychiatric and neurobiological outcomes, including memory deficits. These adverse outcomes can be more severe if each episode of stress is very traumatic. When compared to acute or short term stress relatively little is known about the effects of chronic traumatic stress on memory and molecular changes in hippocampus, a brain area involved in memory processing. Here we studied the effects of chronic traumatic stress in mice by exposing them to adult Long Evan rats for 28 consecutive days and subsequently analyzing behavioral outcomes and the changes in the hippocampus. Results show that stressed mice developed memory deficits when assayed with radial arm maze tasks. However, chronic traumatic stress did not induce anxiety, locomotor hyperactivity or anhedonia. In the hippocampus of stressed mice interleukin-1β protein expression was increased along with decreased corticotropin releasing hormone (CRH) gene expression. Furthermore, there was a reduction in acetylcholine levels in the hippocampus of stressed mice. There were no changes in brain derived neurotrophic factor (BDNF) or nerve growth factor (NGF) levels in the hippocampus of stressed mice. Gene expression of immediate early genes (Zif268, Arc, C-Fos) as well as glucocorticoid and mineralocorticoid receptors were also not affected by chronic stress. These data demonstrate that chronic traumatic stress followed by a recovery period might lead to development of resilience resulting in the development of selected, most vulnerable behavioral alterations and molecular changes in the hippocampus. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Posttraumatic stress symptoms and the diathesis-stress model of chronic pain and disability in patients undergoing major surgery.

    Science.gov (United States)

    Martin, Andrea L; Halket, Eileen; Asmundson, Gordon J G; Flora, David B; Katz, Joel

    2010-01-01

    To (1) use structural equation modeling (SEM) to examine relationships proposed in Turk's diathesis-stress model of chronic pain and disability as well as (2) investigate what role, if any, posttraumatic stress symptoms (PTSS) play in predicting pain disability, relative to some of the other factors in the model. The study sample consisted of 208 patients scheduled for general surgery, 21 to 60 years of age (mean age=47.18 y, SD=9.72 y), who reported experiencing persistent pain for an average of 5.56 years (SD=7.90 y). At their preadmission hospital visit, patients completed the Anxiety Sensitivity Index, Pain Catastrophizing Scale, Pain Anxiety Symptoms Scale-20, Pain Disability Index, posttraumatic stress disorder Checklist, and rated the average intensity of their pain (0 to 10 numeric rating scale). SEM was used to test a model of chronic pain disability and to explore potential relationships between PTSS and factors in the diathesis-stress model. SEM results provided support for a model in which anxiety sensitivity predicted fear of pain and catastrophizing, fear of pain predicted escape/avoidance, and escape/avoidance predicted pain disability. Results also provided support for a feedback loop between disability and fear of pain. SEM analyses provided preliminary support for the inclusion of PTSS in the diathesis-stress model, with PTSS accounting for a significant proportion of the variance in pain disability. Results provide empirical support for aspects of Turk's diathesis-stress model in a sample of patients with persistent pain. Findings also offer preliminary support for the role of PTSS in fear-avoidance models of chronic pain.

  10. Sex hormones affect acute and chronic stress responses in sexually dimorphic patterns: Consequences for depression models.

    Science.gov (United States)

    Guo, Lei; Chen, Yi-Xi; Hu, Yu-Ting; Wu, Xue-Yan; He, Yang; Wu, Juan-Li; Huang, Man-Li; Mason, Matthew; Bao, Ai-Min

    2018-05-21

    Alterations in peripheral sex hormones may play an important role in sex differences in terms of stress responses and mood disorders. It is not yet known whether and how stress-related brain systems and brain sex steroid levels fluctuate in relation to changes in peripheral sex hormone levels, or whether the different sexes show different patterns. We aimed to investigate systematically, in male and female rats, the effect of decreased circulating sex hormone levels following gonadectomy on acute and chronic stress responses, manifested as changes in plasma and hypothalamic sex steroids and hypothalamic stress-related molecules. Experiment (Exp)-1: Rats (14 males, 14 females) were gonadectomized or sham-operated (intact); Exp-2: gonadectomized and intact rats (28 males, 28 females) were exposed to acute foot shock or no stressor; and Exp-3: gonadectomized and intact rats (32 males, 32 females) were exposed to chronic unpredictable mild stress (CUMS) or no stressor. For all rats, plasma and hypothalamic testosterone (T), estradiol (E2), and the expression of stress-related molecules were determined, including corticotropin-releasing hormone, vasopressin, oxytocin, aromatase, and the receptors for estrogens, androgens, glucocorticoids, and mineralocorticoids. Surprisingly, no significant correlation was observed in terms of plasma sex hormones, brain sex steroids, and hypothalamic stress-related molecule mRNAs (p > 0.113) in intact or gonadectomized, male or female, rats. Male and female rats, either intact or gonadectomized and exposed to acute or chronic stress, showed different patterns of stress-related molecule changes. Diminished peripheral sex hormone levels lead to different peripheral and central patterns of change in the stress response systems in male and female rats. This has implications for the choice of models for the study of the different types of mood disorders which also show sex differences. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Effects of acute and chronic stress on telencephalic neurochemistry and gene expression in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Moltesen, Maria; Laursen, Danielle Caroline; Thörnqvist, Per Ove

    2016-01-01

    By filtering relevant sensory inputs and initiating stress responses, the brain is an essential organ in stress coping and adaptation. However, exposure to chronic or repeated stress can lead to allostatic overload, where neuroendocrinal and behavioral reactions to stress become maladaptive. This...

  12. Study of an aqueous lithium chloride desiccant system Part II: Desiccant regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Fumo, Nelson [Universidad Nacional Experimental del Tachira, San Cristobal (Venezuela); Goswami, Yogi [University of Florida, Gainesville (United States)

    2000-07-01

    Desiccant systems have been proposed as alternative to handle the latent load in vapor compression air conditioning for energy saving. The air dehumidification occurs because of the difference in vapor pressure which let the moisture diffuse from the air to the liquid desiccant. The diffused moisture cause a dilution of the desiccant which must be regenerated to return it to the original conditions. This paper presents the results from a study of the performance of a packed tower regenerator for an aqueous lithium chloride desiccant dehumidification system. The rate of water evaporation, as well as the effectiveness of the regeneration process were assessed under the effects of variables such as air and desiccant flow rates, air temperature and humidity, and desiccant temperature and concentration. A variation of the oeberg and Goswami mathematical model was used to predict the experimental findings given satisfactory results. [Spanish] Se han propuesto sistemas desecantes para hacerse cargo de la carga latente en acondicionamiento de aire por compresion de vapor para el ahorro de energia. La deshumidificacion del aire ocurre en razon de la diferencia de presion de vapor que deja la humedad difusa del aire en el desecante liquido. La humedad difusa del aire origina una dilucion del desecante el cual debe de ser regenerado para regresarlo a sus condiciones originales. Este documento presenta los resultados de un estudio sobre el comportamiento de un regenerador de torre empacada para un sistema de deshumidificacion de solucion desecante de cloruro de litio. El regimen de evaporacion de agua, asi como tambien la efectividad del proceso de regeneracion que se evaluo bajo los efectos de variables tales como los regimenes de flujo de aire y de desecante, temperatura del aire y humedad, y temperatura y concentracion del desecante. Una variacion del modelo matematico de Oberg y Goswami se uso para predecir los resultados experimentales que dieron resultados satisfactorios.

  13. 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...... and pharmacologic therapies for hyperuricemia are discussed. Finally, we review some new therapy options in diabetic nephropathy including antidiabetic agents (noninsulin dependent), plant antioxidants, and food components as alternative antioxidant therapies....

  14. 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...

  15. [Corticotropic axis and chronic stress in abdominal obesity and metabolic syndrome].

    Science.gov (United States)

    Boullu-Ciocca, S; Verger, P; Bocquier, A; Oliver, C

    2005-12-03

    Several indicators of corticotropic axis hyperactivity have been observed in common abdominal obesity, which is clinically similar to the obesity found in Cushing's syndrome. Corticotropic axis hyperactivity may be involved in the development and metabolic and cardiovascular complications of abdominal obesity. Several mechanisms may be responsible for this hormonal dysregulation: genetic, lifestyle, and nutritional factors, and chronic stress. We note the necessity of methodologically-impeccable clinical studies for an objective evaluation of the role of stress in obesity.

  16. Cannabinoids ameliorate impairments induced by chronic stress to synaptic plasticity and short-term memory.

    Science.gov (United States)

    Abush, Hila; Akirav, Irit

    2013-07-01

    Repeated stress is one of the environmental factors that precipitates and exacerbates mental illnesses like depression and anxiety as well as cognitive impairments. We have previously shown that cannabinoids can prevent the effects of acute stress on learning and memory. Here we aimed to find whether chronic cannabinoid treatment would alleviate the long-term effects of exposure to chronic restraint stress on memory and plasticity as well as on behavioral and neuroendocrine measures of anxiety and depression. Late adolescent rats were exposed to chronic restraint stress for 2 weeks followed each day by systemic treatment with vehicle or with the CB1/2 receptor agonist WIN55,212-2 (1.2 mg/kg). Thirty days after the last exposure to stress, rats demonstrated impaired long-term potentiation (LTP) in the ventral subiculum-nucleus accumbens (NAc) pathway, impaired performance in the prefrontal cortex (PFC)-dependent object-recognition task and the hippocampal-dependent spatial version of this task, increased anxiety levels, and significantly reduced expression of glucocorticoid receptors (GRs) in the amygdala, hippocampus, PFC, and NAc. Chronic WIN55,212-2 administration prevented the stress-induced impairment in LTP levels and in the spatial task, with no effect on stress-induced alterations in unconditioned anxiety levels or GR levels. The CB1 antagonist AM251 (0.3 mg/kg) prevented the ameliorating effects of WIN55,212-2 on LTP and short-term memory. Hence, the beneficial effects of WIN55,212-2 on memory and plasticity are mediated by CB1 receptors and are not mediated by alterations in GR levels in the brain areas tested. Our findings suggest that cannabinoid receptor activation could represent a novel approach to the treatment of cognitive deficits that accompany a variety of stress-related neuropsychiatric disorders.

  17. Variations in biofilm formation, desiccation resistance and Benzalkonium chloride susceptibility among Listeria monocytogenes strains isolated in Canada.

    Science.gov (United States)

    Piercey, Marta J; Ells, Timothy C; Macintosh, Andrew J; Truelstrup Hansen, Lisbeth

    2017-09-18

    Listeria monocytogenes is a pathogenic foodborne microorganism noted for its ability to survive in the environment and food processing facilities. Survival may be related to the phenotype of individual strains including the ability to form biofilms and resist desiccation and/or sanitizer exposure. The objectives of this research were to compare 14 L. monocytogenes strains isolated from blood (3), food (6) and water (5) with respect to their benzalkonium chloride (BAC) sensitivity, desiccation resistance, and ability to form biofilm. Correlations were tested between those responses, and the presence of the SSI-1 (Stress Survival Islet) and LGI1/CC8 (Listeria Genomic Island 1 in a clonal complex 8 background) genetic markers. Genetic sequences from four strains representing different phenotypes were also probed for predicted amino acid differences in biofilm, desiccation, and membrane related genes. The water isolates were among the most desiccation susceptible strains, while strains exhibiting desiccation resistance harboured SSI-1 or both the SSI-1 and LGI1/CC8 markers. BAC resistance was greatest in planktonic LGI1/CC8 cells (relative to non-LGI1/CC8 cells), and higher BAC concentrations were also needed to inhibit the formation of biofilm by LGI1/CC8 strains during incubation for 48h and 6days compared to other strains. Formation of biofilm on stainless steel was not significantly (p>0.05) different among the strains. Analysis of genetic sequence data from desiccation and BAC sensitive (CP4 5-1, CP5 2-3, both from water), intermediate (Lm568, food) and desiccation and BAC resistant (08 5578, blood, human outbreak) strains led to the finding of amino acid differences in predicted functional protein domains in several biofilm, desiccation and peptidoglycan related genes (e.g., lmo0263, lmo0433, lmo0434, lmo0771, lmo0973, lmo1080, lmo1224, lmo1370, lmo1744, and lmo2558). Notably, the LGI1/CC8 strain 08-5578 had a frameshift mutation in lmo1370, a gene previously

  18. 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.

  19. [Stress related correlates of anxiety and depression in girls with chronic headache].

    Science.gov (United States)

    Bung, Simone; Saile, Helmut; Laessle, Reinhold

    2018-01-01

    Chronic headache in adolescents is frequent and often associated with anxiety and depression. The present study investigated, whether psychological and physical stress symptoms have an infl uence on the occurrence of anxiety and depression and what is the role of stress coping. The sample consisted of 77 15 years old girls with chronic headache and 72 girls, who served as controls. Stress symptoms and stress coping were measured with the Stressverarbeitungsfragebogen für Kinder und Jugendliche (Coping with Stress Questionnaire for Children and Adolescents), depression was assessed by the Depression Inventory for Children and Adolescents, anxiety by the State-Trait Anxiety Inventory for Children. Linear regression was used to analyze the relationship between stress factors and anxiety resp. depression. Physical stress symptoms were related to anxiety, but not to depression. Coping strategies of the depressed as well as the anxious children were characterized by stress reinforcing behaviors. The results point to focusing on physical symptoms in the anxious headache patients and to avoidance coping in the depressed children.

  20. Cognitive deficits in the rat chronic mild stress model for depression: relation to anhedonic-like responses

    DEFF Research Database (Denmark)

    Henningsen, Kim; Andreasen T., Jesper; Bouzinova, Elena V.

    2009-01-01

    in the spontaneous alternation test, possibly reflecting a deficit in working memory. This effect was independent of whether the stressed rats were anhedonic-like or stress-resilient as measured by their sucrose intake. CMS did not influence performance in passive avoidance and auditory cued fear conditioning......The chronic mild stress (CMS) protocol is widely used to evoke depressive-like behaviours in laboratory rats. The aim of the present study was to examine the effects of chronic stress on cognitive performance. About 70% of rats exposed to 7 weeks of chronic mild stress showed a gradual reduction...... in consumption of a sucrose solution, indicating an anhedonic-like state. The remaining rats did not reduce their sucrose intake, but appeared resilient to the stress-induced effects on sucrose intake. Cognitive profiling of the CMS rats revealed that chronic stress had a negative effect on performance...

  1. 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.

  2. Effects of ethanol on social avoidance induced by chronic social defeat stress in mice.

    Science.gov (United States)

    Favoretto, Cristiane A; Macedo, Giovana C; Quadros, Isabel M H

    2017-01-01

    In rodents, chronic social defeat stress promotes deficits in social interest and social interaction. We further explored these antisocial effects by comparing the consequences of two different defeat stress protocols (episodic vs. continuous stress) in a social investigation test. We expected that continuous, but not episodic, stress would induce social deficits in this model. Furthermore, we tested whether a potentially anxiolytic dose of ethanol reverses social deficits induced by defeat stress. Male Swiss mice were exposed to a 10-day social defeat protocol, using daily confrontations with an aggressive resident mouse. Episodic stress consisted of brief defeat episodes, after which the defeated mouse was returned to its home cage, until the next defeat 24 h later (n = 7-11/group). For continuous stress, similar defeat episodes were followed by cohabitation with the aggressive resident for 24 h, separated by a perforated divider, until the following defeat (n = 8-14/group). Eight days after stress termination, defeated and control mice were assessed in a social investigation test, after treatment with ethanol (1.0 g/kg, i.p.) or 0.9% saline. Considering the time spent investigating a social target, mice exposed to episodic or continuous social stress showed less social investigation than controls (p stress or ethanol. Thus, a history of social defeat stress, whether episodic or continuous, promotes deficits in social investigation that were not reversed by acute treatment with ethanol.

  3. Chronic work stress and decreased vagal tone impairs decision making and reaction time in jockeys.

    Science.gov (United States)

    Landolt, Kathleen; Maruff, Paul; Horan, Ben; Kingsley, Michael; Kinsella, Glynda; O'Halloran, Paul D; Hale, Matthew W; Wright, Bradley J

    2017-10-01

    The inverse relationship between acute stress and decision-making is well documented, but few studies have investigated the impact of chronic stress. Jockeys work exhaustive schedules and have extremely dangerous occupations, with safe performance requiring quick reaction time and accurate decision-making. We used the effort reward imbalance (ERI) occupational stress model to assess the relationship of work stress with indices of stress physiology and decision-making and reaction time. Jockeys (N=32) completed computerised cognitive tasks (Cogstate) on two occasions; September and November (naturally occurring lower and higher stress periods), either side of an acute stress test. Higher ERI was correlated with the cortisol awakening responses (high stress r=-0.37; low stress r=0.36), and with decrements in decision-making comparable to having a blood alcohol concentration of 0.08 in the high stress period (pdecision-making. Potentially, this may be attributed to a 'tipping point' whereby the higher ERI reported by jockeys in the high stress period decreases vagal tone, which may contribute to reduced decision-making abilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. 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

  5. The chicken or the egg? Adaptation to desiccation and salinity tolerance in a lineage of water beetles.

    Science.gov (United States)

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

    2017-10-01

    Transitions from fresh to saline habitats are restricted to a handful of insect lineages, as the colonization of saline waters requires specialized mechanisms to deal with osmotic stress. Previous studies have suggested that tolerance to salinity and desiccation could be mechanistically and evolutionarily linked, but the temporal sequence of these adaptations is not well established for individual lineages. We combined molecular, physiological and ecological data to explore the evolution of desiccation resistance, hyporegulation ability (i.e., the ability to osmoregulate in hyperosmotic media) and habitat transitions in the water beetle genus Enochrus subgenus Lumetus (Hydrophilidae). We tested whether enhanced desiccation resistance evolved before increases in hyporegulation ability or vice versa, or whether the two mechanisms evolved in parallel. The most recent ancestor of Lumetus was inferred to have high desiccation resistance and moderate hyporegulation ability. There were repeated shifts between habitats with differing levels of salinity in the radiation of the group, those to the most saline habitats generally occurring more rapidly than those to less saline ones. Significant and accelerated changes in hyporegulation ability evolved in parallel with smaller and more progressive increases in desiccation resistance across the phylogeny, associated with the colonization of meso- and hypersaline waters during global aridification events. All species with high hyporegulation ability were also desiccation-resistant, but not vice versa. Overall, results are consistent with the hypothesis that desiccation resistance mechanisms evolved first and provided the physiological basis for the development of hyporegulation ability, allowing these insects to colonize and diversify across meso- and hypersaline habitats. © 2017 John Wiley & Sons Ltd.

  6. 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...

  7. 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.

  8. If It Goes up, Must It Come Down? Chronic Stress and the Hypothalamic-Pituitary Adrenocortical Axis in Humans

    Science.gov (United States)

    Miller, Gregory E.; Chen, Edith; Zhou, Eric S.

    2007-01-01

    The notion that chronic stress fosters disease by activating the hypothalamic-pituitary adrenocortical (HPA) axis is featured prominently in many theories. The research linking chronic stress and HPA function is contradictory, however, with some studies reporting increased activation, and others reporting the opposite. This meta-analysis showed…

  9. Opposite effects of glucocorticoid receptor activation on hippocampal CA1 dendritic complexity in chronically stressed and handled animals

    NARCIS (Netherlands)

    Alfarez, D.N.; Karst, H.; Velzing, E.H.; Joëls, M.; Krugers, H.J.

    2008-01-01

    Remodeling of synaptic networks is believed to contribute to synaptic plasticity and long-term memory performance, both of which are modulated by chronic stress. We here examined whether chronic stress modulates dendritic complexity of hippocampal CA1 pyramidal cells, under conditions of basal as

  10. 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…

  11. Chronic mitochondrial uncoupling treatment prevents acute cold-induced oxidative stress in birds.

    Science.gov (United States)

    Stier, Antoine; Massemin, Sylvie; Criscuolo, François

    2014-12-01

    Endotherms have evolved two major types of thermogenesis that allow them to actively produce heat in response to cold exposure, either through muscular activity (i.e. shivering thermogenesis) or through futile electro-chemical cycles (i.e. non-shivering thermogenesis). Amongst the latter, mitochondrial uncoupling is of key importance because it is suggested to drive heat production at a low cost in terms of oxidative stress. While this has been experimentally shown in mammals, the oxidative stress consequences of cold exposure and mitochondrial uncoupling are clearly less understood in the other class of endotherms, the birds. We compared metabolic and oxidative stress responses of zebra finches chronically treated with or without a chemical mitochondrial uncoupler (2,4-dinitrophenol: DNP), undergoing an acute (24 h) and a chronic (4 weeks) cold exposure (12 °C). We predicted that control birds should present at least a transient elevation of oxidative stress levels in response to cold exposure. This oxidative stress cost should be more pronounced in control birds than in DNP-treated birds, due to their lower basal uncoupling state. Despite similar increase in metabolism, control birds presented elevated levels of DNA oxidative damage in response to acute (but not chronic) cold exposure, while DNP-treated birds did not. Plasma antioxidant capacity decreased overall in response to chronic cold exposure. These results show that acute cold exposure increases oxidative stress in birds. However, uncoupling mitochondrial functioning appears as a putative compensatory mechanism preventing cold-induced oxidative stress. This result confirms previous observations in mice and underlines non-shivering thermogenesis as a putative key mechanism for endotherms in mounting a response to cold at a low oxidative cost.

  12. 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.

  13. 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…

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

    DEFF Research Database (Denmark)

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

    2005-01-01

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

  15. Symptom Differences in Acute and Chronic Presentation of Childhood Post-Traumatic Stress Disorder.

    Science.gov (United States)

    Famularo, Richard; And Others

    1990-01-01

    Twenty-four child abuse victims, age 5-13, were diagnosed with posttraumatic stress disorder (PTSD). Children with the acute form of PTSD exhibited such symptoms as difficulty falling asleep, hypervigilance, nightmares, and generalized anxiety. Children exhibiting chronic PTSD exhibited increased detachment, restricted range of affect,…

  16. Stress in adolescents with a chronically ill parent: inspiration from Rolland's Family Systems-Illness model

    NARCIS (Netherlands)

    Sieh, D.S.; Dikkers, A.L.C.; Visser-Meily, J.M.A.; Meijer, A.M.

    2012-01-01

    This article was inspired by Rolland’s Family Systems-Illness (FSI) model, aiming to predict adolescent stress as a function of parental illness type. Ninety-nine parents with a chronic medical condition, 82 partners, and 158 adolescent children (51 % girls; mean age = 15.1 years) participated in

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

    Indian Academy of Sciences (India)

    2012-08-03

    Aug 3, 2012 ... 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 ...

  18. Association between objectively measured physical activity, chronic stress and leukocyte telomere length.

    Science.gov (United States)

    von Känel, Roland; Bruwer, Erna J; Hamer, Mark; de Ridder, J Hans; Malan, Leoné

    2017-10-01

    Physical activity (PA) attenuates chronic stress and age-related and cardiovascular disease risks, whereby potentially slowing telomere shortening. We aimed to study the association between seven-day objectively measured habitual PA, chronic stress and leukocyte telomere length. Study participants were African (N.=96) and Caucasian (N.=107) school teachers of the Sympathetic activity and Ambulatory Blood Pressure in Africans study. All lifestyle characteristics (including PA) were objectively measured. The general health questionnaire and serum cortisol were assessed as psychological and physical measures of chronic stress. Leukocyte telomere length was measured using the quantitative real-time polymerase chain reaction. Africans had significantly shorter telomeres (Pstress or telomere length. However, more time spent with light intensity PA time was significantly and independently correlated with lower waist circumference (r=-0.21, P=0.004); in turn, greater waist circumference was significantly associated shorter telomeres (β=-0.17 [-0.30, -0.03], P=0.017). Habitual PA of different intensity was not directly associated with markers of chronic stress and leukocyte telomere length in this biethnic cohort. However, our findings suggest that light intensity PA could contribute to lowered age-related disease risk and healthy ageing by facilitating maintenance of a normal waist circumference.

  19. 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.

  20. Incoordination among Subcellular Compartments Is Associated with Depression-Like Behavior Induced by Chronic Mild Stress

    Science.gov (United States)

    Xu, Aiping; Cui, Shan

    2016-01-01

    Background: Major depressive disorder is characterized as persistent low mood. A chronically stressful life in genetically susceptible individuals is presumably the major etiology that leads to dysfunctions of monoamine and hypothalamus-pituitary-adrenal axis. These pathogenic factors cause neuron atrophy in the limbic system for major depressive disorder. Cell-specific pathophysiology is unclear, so we investigated prelimbic cortical GABAergic neurons and their interaction with glutamatergic neurons in depression-like mice. Methods: Mice were treated with chronic unpredictable mild stress for 3 weeks until they expressed depression-like behaviors confirmed by sucrose preference, Y-maze, and forced swimming tests. The structures and functions of GABAergic and glutamatergic units in prelimbic cortices were studied by cell imaging and electrophysiology in chronic unpredictable mild stress-induced depression mice vs controls. Results: In depression-like mice, prelimbic cortical GABAergic neurons show incoordination among the subcellular compartments, such as decreased excitability and synaptic outputs as well as increased reception from excitatory inputs. GABAergic synapses on glutamatergic cells demonstrate decreased presynaptic innervation and increased postsynaptic responsiveness. Conclusions: Chronic unpredictable mild stress-induced incoordination in prelimbic cortical GABAergic and glutamatergic neurons dysregulates their target neurons, which may be the pathological basis for depressive mood. The rebalance of compatibility among subcellular compartments would be an ideal strategy to treat neural disorders. PMID:26506857

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

    NARCIS (Netherlands)

    Kole, MHP; Czeh, B; Fuchs, E

    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

  2. Chronic light reduction reduces overall resilience to additional shading stress in the seagrass

    NARCIS (Netherlands)

    Yaakub, S.M.; Chen, E.; Bouma, T.; Erftemeijer, P.L.A.; Todd, P.A.

    2014-01-01

    Seagrasses have substantial capacity to survive long periods of light reduction, but how acclimation to chronic low light environments may influence their ability to cope with additional stress is poorly understood. This study examines the effect of temporal light reduction by adding two levels of

  3. Correlates of cortisol in human hair: implications for epidemiologic studies on health effects of chronic stress.

    Science.gov (United States)

    Wosu, Adaeze C; Valdimarsdóttir, Unnur; Shields, Alexandra E; Williams, David R; Williams, Michelle A

    2013-12-01

    Assessment of cortisol concentrations in hair is one of the latest innovations for measuring long-term cortisol exposure. We performed a systematic review of correlates of cortisol in human hair to inform the design, analysis, and interpretation of future epidemiologic studies. Relevant publications were identified through electronic searches on PubMed, WorldCat, and Web of Science using keywords, "cortisol," "hair," "confounders," "chronic," "stress," and "correlates." Thirty-nine studies were included in this review. Notwithstanding scarce data and some inconsistencies, investigators have found hair cortisol concentrations to be associated with stress-related psychiatric symptoms and disorders (e.g., post-traumatic stress disorder), medical conditions indicating chronic activation of the hypothalamic-pituitary-adrenal axis (e.g., Cushing's syndrome), and other life situations associated with elevated risk of chronic stress (e.g., shiftwork). Results from some studies suggest that physical activity, adiposity, and substance abuse may be correlates of hair cortisol concentrations. In contrast to measures of short-term cortisol release (saliva, blood, and urine), cigarette smoking and use of oral contraceptives appear not to be associated with hair cortisol concentrations. Studies of pregnant women indicate increased hair cortisol concentrations across successive trimesters. The study of hair cortisol presents a unique opportunity to assess chronic alterations in cortisol concentrations in epidemiologic studies. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Chicken hepatic response to chronic heat stress using integrated transcriptome and metabolome analysis.

    Directory of Open Access Journals (Sweden)

    Sara F Jastrebski

    Full Text Available The liver plays a central role in metabolism and is important in maintaining homeostasis throughout the body. This study integrated transcriptomic and metabolomic data to understand how the liver responds under chronic heat stress. Chickens from a rapidly growing broiler line were heat stressed for 8 hours per day for one week and liver samples were collected at 28 days post hatch. Transcriptome analysis reveals changes in genes responsible for cell cycle regulation, DNA replication, and DNA repair along with immune function. Integrating the metabolome and transcriptome data highlighted multiple pathways affected by heat stress including glucose, amino acid, and lipid metabolism along with glutathione production and beta-oxidation.

  5. [Effects of chronic experimental stress and endogenous opioids on histophysiological parameters of the thyroid gland].

    Science.gov (United States)

    Krasnoperov, R A; Glumova, V A; Riashchikov, S N; Proshutina, N E

    1992-01-01

    In adult rabbits stress was modelled by electrostimulation of the hypothalamus ventromedial nucleus (15-hour-long session during 30 days) and medulla's raphe big nucleus which is one of the central places of the opioid peptides synthesis was irritated. It is revealed, that under stress thyroid gland responds by serum T3 increase in comparison with control animals with statistically significant variability of the T4 profile. Chronicity of the emotional agitation involves destructive changes in the thyroid parenchyma the hurting effect of the negative emotional factor is expressed less during opioid peptides complex activation. It is suggested that there are its own stress-limiting mechanisms in thyroid gland.

  6. 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.

  7. 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.

  8. 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)

    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 mesenteric fat and inhibits acute stress-induced hypothalamic-pituitary-adrenal (HPA) axis activity. The effect of...

  9. 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.

  10. Chronic stress associated with hypercaloric diet changes the hippocampal BDNF levels in male Wistar rats.

    Science.gov (United States)

    Macedo, I C; Rozisky, J R; Oliveira, C; Oliveira, C M; Laste, G; Nonose, Y; Santos, V S; Marques, P R; Ribeiro, M F M; Caumo, W; Torres, I L S

    2015-06-01

    Chronic stress, whether associated with obesity or not, leads to different neuroendocrine and psychological changes. Obesity or being overweight has become one of the most serious worldwide public health problems. Additionally, it is related to a substantial increase in daily energy intake, which results in substituting nutritionally adequate meals for snacks. This metabolic disorder can lead to morbidity, mortality, and reduced quality of life. On the other hand, brain-derived neurotrophic factor (BDNF) is widely expressed in all brain regions, particularly in the hypothalamus, where it has important effects on neuroprotection, synaptic plasticity, mammalian food intake-behavior, and energy metabolism. BDNF is involved in many activities modulated by the hypothalamic-pituitary-adrenal (HPA) axis. Therefore, this study aims to evaluate the effect of obesity associated with chronic stress on the BDNF central levels of rats. Obesity was controlled by analyzing the animals' caloric intake and changes in body weight. As a stress parameter, we analyzed the relative adrenal gland weight. We found that exposure to chronic restraint stress during 12 weeks increases the adrenal gland weight, decreases the BDNF levels in the hippocampus and is associated with a decrease in the calorie and sucrose intake, characterizing anhedonia. These effects can be related stress, a phenomenon that induces depression-like behavior. On the other hand, the rats that received the hypercaloric diet had an increase in calorie intake and became obese, which was associated with a decrease in hypothalamus BDNF levels. Copyright © 2015. Published by Elsevier Ltd.

  11. 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.

  12. Chronic shin splints. Classification and management of medial tibial stress syndrome.

    Science.gov (United States)

    Detmer, D E

    1986-01-01

    A clinical classification and treatment programme has been developed for chronic medial tibial stress syndrome. Medial tibial stress syndrome has been reported to be either tibial stress fracture or microfracture, tibial periostitis, or distal deep posterior chronic compartment syndrome. Three chronic types exist and may coexist: Type I (tibial microfracture, bone stress reaction or cortical fracture); type II (periostalgia from chronic avulsion of the periosteum at the periosteal-fascial junction); and type III (chronic compartment syndrome syndrome). Type I disease is treated nonoperatively. Operations for resistant types II and III medial tibial stress syndrome were performed in 41 patients. Bilaterality was common (type II, 50% type III, 88%). Seven had coexistent type II/III; one had type I/II. Preoperative symptoms averaged 24 months in type II, 6 months in type III, and 33 months in types II/III. Mean age was 22 years (15 to 51). Resting compartment pressures were normal in type II (mean 12 mm Hg) and elevated in type III and type II/III (mean 23 mm Hg). Type II and type II/III patients received fasciotomy plus periosteal cauterisation. Type III patients had fasciotomy only. All procedures were performed on an outpatient basis using local anaesthesia. Follow up was complete and averaged 6 months (2 to 14 months). Improved performance was as follows: type II, 93%, type III, 100%; type II/III, 86%. Complete cures were as follows: type II, 78%; type III, 75%; and type II/III, 57%. This experience suggests that with precise diagnosis and treatment involving minimal risk and cost the athlete has a reasonable chance of return to full activity.

  13. 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.

  14. [Clinical, functional and biochemical characteristics of arterial hypertension in military men under chronic stress].

    Science.gov (United States)

    Shpagina, L A; Ermakova, M A; Volkova, E A; Iakovleva, S A

    2008-01-01

    Peculiarities of military occupational activities are repeated stress and high degree of psychoemotional strain. The article deals with results of momentary study covering a select from military men cohort, with thyroid tests, renal functional tests, diurnal monitoring of blood pressure and psychologic state assessment. Course of arterial hypertension in military men subjected to chronic stress presents prevailing systolic-diastolic and diastolic variants with excessive decrease of blood pressure at night, with high values of albuminuria. Psychologic state of the military men examined, whe were subjects to chronic stress, was mostly mixed reactivity type with general overstrain and somatization of inner conflict (psychosomatic variant of dysadaptation). The authors demonstrated close correlation between intrinsic emotional strain degree with arterial hypertension type according to "hyper-dipper" variant and free T3 level.

  15. 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...

  16. Dietary antioxidents and oxidative stress in predialysis chronic kidney disease patients.

    Science.gov (United States)

    L Gupta, Krishan; Sahni, Nancy

    2012-10-01

    Dietary antioxidants are important in protecting against human diseases. Oxidative stress, a non- traditional risk factors of cardio-vascular disease is far more prevalent in chronic kidney disease (CKD) patients than in normal subjects. Directory of Open Access Journals (DOAJ), Google Scholar, Pubmed (NLM), LISTA (EBSCO) and Web of Science have been searched. Oxidative stress could be a consequence of an increase in reactive oxygen species as well as a decrease in antioxidant defenses. Among the important factors that can be involved in triggering oxidative stress is insufficient dietary intake of antioxidants. Malnourished CKD patients are reported to have more oxidative stress than well nourished ones. Moving beyond the importance of assessment of dietary protein and energy in pre dialysis CKD patients to the assessment of dietary antioxidants is of utmost importance to help combat enhanced oxidative stress levels in such patients.

  17. Chronic stress effects and their reversibility on the Fallopian tubes and uterus in rats.

    Science.gov (United States)

    Divyashree, S; Yajurvedi, H N

    2018-01-01

    The durational effects of chronic stress on the Fallopian tubes and uterus were studied by exposing rats to stressors in the form of restraint (1h) and forced swimming (15min) daily for 4, 8 or 12 weeks. One group of stressed rats from each time period was then maintained without exposure to stressors for a further 4 weeks to assess their ability to recover from stress. All time periods of stress exposure resulted in decreased weight of the body and Fallopian tubes; however, the relative weight of the uterus and serum concentrations of oestradiol and insulin increased significantly. The antioxidant potential was decreased with increased malondialdehyde concentrations in the Fallopian tubes following all durations of exposure and after 4 and 8 weeks of stress exposure in the uterus. Interestingly, rats stressed for 12 weeks showed an increase in serum testosterone concentration and antioxidant enzyme activities with a decrease in malondialdehyde concentration in the uterus. The antioxidant enzyme activities and malondialdehyde concentration in the Fallopian tubes of all recovery group rats were similar to stressed rats. However, in the uterus these parameters were similar to controls in recovery group rats after 4 weeks or 8 weeks of exposure, but after 12 weeks of stress exposure these parameters did not return to control levels following the recovery period. These results reveal, for the first time, that chronic stress elicits an irreversible decrease in antioxidant defence in the Fallopian tubes irrespective of exposure duration, whereas the uterus develops reversible oxidative stress under short-term exposure but increased antioxidant potential with endometrial proliferation following long-term exposure.

  18. 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.

  19. Selective amotivation deficits following chronic psychosocial stress in mice.

    Science.gov (United States)

    Tsai Cabal, Alejandro; Ioanas, Horea-Ioan; Seifritz, Erich; Saab, Bechara J

    2017-01-15

    Amotivation is a major symptom of several psychiatric disorders. However, which specific motivations are most affected in various illnesses is not well understood. In major depressive disorder (MDD), anecdotal evidence suggests the motivation to explore may be especially affected, but direct evidence from either patients or animal models is lacking. To investigate the potential for, and nature of, exploratory drive deficits in MDD, we subjected mice to a chronic social defeat (CSD) manipulation that gives rise to a MDD-like behavioural ensemble, and performed a behavioural battery to examine bodyweight homeostasis, ambulation, anxiety, exploratory behaviour motivated by either novelty or fear, and short-term memory. Consistent with previous reports, we found a disruption of bodyweight homeostasis and reduced ambulation following CSD treatment, but we found no evidence for anxiogenic effects or impairments in short-term memory. Surprisingly, we also observed profoundly delayed and diminished exploration of novel, safe space following CSD, while exploration motivated by fear remained intact. These results extend our knowledge of the behavioural phenotypes in mice resulting from CSD by homing in on specific motivational drives. In MDD patients, reduced exploration could compound disease symptomatology by preventing engagement in what could be rewarding exploration experiences, and targeting deficits in the motivation to explore may represent a novel avenue for treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Biomarkers of cardiovascular stress and incident chronic kidney disease.

    Science.gov (United States)

    Ho, Jennifer E; Hwang, Shih-Jen; Wollert, Kai C; Larson, Martin G; Cheng, Susan; Kempf, Tibor; Vasan, Ramachandran S; Januzzi, James L; Wang, Thomas J; Fox, Caroline S

    2013-11-01

    Growth differentiation factor-15 (GDF-15), soluble ST2 (sST2), and high-sensitivity troponin I (hsTnI) are emerging predictors of adverse clinical outcomes. We examined whether circulating concentrations are related to the development of kidney disease in the community. Plasma GDF-15, sST2, and hsTnI concentrations were measured in 2614 Framingham Offspring cohort participants (mean age 57 years, 54% women) at the sixth examination cycle (1995-1998). Associations of biomarkers with incident chronic kidney disease [CKD, eGFR statistically significant in primary analyses. Participants were followed over a mean of 9.5 years. Higher plasma GDF-15 was associated with incident CKD [multivariable-adjusted odds ratio (OR) 1.9 per 1-U increase in log-GDF-15, 95% CI 1.6-2.3, P statistic increased from 0.826 to 0.845 (P = 0.0007), and categorical net reclassification was 6.3% (95% CI, 2.7-9.9%). Higher circulating GDF-15 is associated with incident renal outcomes and improves risk prediction of incident CKD. These findings may provide insights into the mechanisms of renal injury.

  1. Regulation of brain-derived neurotrophic factor (BDNF) in the chronic unpredictable stress rat model and the effects of chronic antidepressant treatment

    DEFF Research Database (Denmark)

    Larsen, Marianne H; Mikkelsen, Jens D; Hay-Schmidt, Anders

    2010-01-01

    Chronic unpredictable stress (CUS) is a widely used animal model of depression. The present study was undertaken to investigate behavioral, physiological and molecular effects of CUS and/or chronic antidepressant treatment (venlafaxine or imipramine) in the same set of animals. Anhedonia, a core ...

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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.

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

    KAUST Repository

    Lefers, Ryan; Srivatsa Bettahalli, N.M.; Fedoroff, Nina V.; Nunes, Suzana Pereira; Leiknes, TorOve

    2018-01-01

    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.

  10. 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)

  11. 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.

  12. Chronic unpredictable stress decreases expression of brain-derived neurotrophic factor (BDNF) in mouse ovaries: relationship to oocytes developmental potential.

    Science.gov (United States)

    Wu, Li-Min; Hu, Mei-Hong; Tong, Xian-Hong; Han, Hui; Shen, Ni; Jin, Ren-Tao; Wang, Wei; Zhou, Gui-Xiang; He, Guo-Ping; Liu, Yu-Sheng

    2012-01-01

    Brain-derived neurotropic factor (BDNF) was originally described in the nervous system but has been shown to be expressed in ovary tissues recently, acting as a paracrine/autocrine regulator required for developments of follicles and oocytes. Although it is generally accepted that chronic stress impairs female reproduction and decreases the expression of BDNF in limbic structures of central nervous system, which contributes to mood disorder. However, it is not known whether chronic stress affects oocytes developments, nor whether it affects expression of BDNF in ovary. Mice were randomly assigned into control group, stressed group, BDNF-treated group and BDNF-treated stressed group. The chronic unpredictable mild stress model was used to produce psychosocial stress in mice, and the model was verified by open field test and hypothalamic-pituitary-adrenal (HPA) axis activity. The methods of immunohistochemistry and western blotting were used to detect BDNF protein level and distribution. The number of retrieved oocytes, oocyte maturation, embryo cleavage and the rates of blastocyst formation after parthenogenetic activation were evaluated. Chronic unpredictable stress decreased the BDNF expression in antral follicles, but didn't affect the BDNF expression in primordial, primary and secondary follicles. Chronic unpredictable stress also decreased the number of retrieved oocytes and the rate of blastocyst formation, which was rescued by exogenous BDNF treatment. BDNF in mouse ovaries may be related to the decreased number of retrieved oocytes and impaired oocytes developmental potential induced by chronic unpredictable stress.

  13. Chronic unpredictable stress decreases expression of brain-derived neurotrophic factor (BDNF in mouse ovaries: relationship to oocytes developmental potential.

    Directory of Open Access Journals (Sweden)

    Li-Min Wu

    Full Text Available BACKGROUND: Brain-derived neurotropic factor (BDNF was originally described in the nervous system but has been shown to be expressed in ovary tissues recently, acting as a paracrine/autocrine regulator required for developments of follicles and oocytes. Although it is generally accepted that chronic stress impairs female reproduction and decreases the expression of BDNF in limbic structures of central nervous system, which contributes to mood disorder. However, it is not known whether chronic stress affects oocytes developments, nor whether it affects expression of BDNF in ovary. METHODS: Mice were randomly assigned into control group, stressed group, BDNF-treated group and BDNF-treated stressed group. The chronic unpredictable mild stress model was used to produce psychosocial stress in mice, and the model was verified by open field test and hypothalamic-pituitary-adrenal (HPA axis activity. The methods of immunohistochemistry and western blotting were used to detect BDNF protein level and distribution. The number of retrieved oocytes, oocyte maturation, embryo cleavage and the rates of blastocyst formation after parthenogenetic activation were evaluated. RESULTS: Chronic unpredictable stress decreased the BDNF expression in antral follicles, but didn't affect the BDNF expression in primordial, primary and secondary follicles. Chronic unpredictable stress also decreased the number of retrieved oocytes and the rate of blastocyst formation, which was rescued by exogenous BDNF treatment. CONCLUSION: BDNF in mouse ovaries may be related to the decreased number of retrieved oocytes and impaired oocytes developmental potential induced by chronic unpredictable stress.

  14. 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.

  15. Chronic exertional compartment syndrome with medial tibial stress syndrome in twins.

    Science.gov (United States)

    Banerjee, Purnajyoti; McLean, Christopher

    2011-06-14

    Chronic exertional compartment syndrome and medial tibial stress syndrome are uncommon conditions that affect long-distance runners or players involved in team sports that require extensive running. We report 2 cases of bilateral chronic exertional compartment syndrome, with medial tibial stress syndrome in identical twins diagnosed with the use of a Kodiag monitor (B. Braun Medical, Sheffield, United Kingdom) fulfilling the modified diagnostic criteria for chronic exertional compartment syndrome as described by Pedowitz et al, which includes: (1) pre-exercise compartment pressure level >15 mm Hg; (2) 1 minute post-exercise pressure >30 mm Hg; and (3) 5 minutes post-exercise pressure >20 mm Hg in the presence of clinical features. Both patients were treated with bilateral anterior fasciotomies through minimal incision and deep posterior fasciotomies with tibial periosteal stripping performed through longer anteromedial incisions under direct vision followed by intensive physiotherapy resulting in complete symptomatic recovery. The etiology of chronic exertional compartment syndrome is not fully understood, but it is postulated abnormal increases in intramuscular pressure during exercise impair local perfusion, causing ischemic muscle pain. No familial predisposition has been reported to date. However, some authors have found that no significant difference exists in the relative perfusion, in patients, diagnosed with chronic exertional compartment syndrome. Magnetic resonance images of affected compartments have indicated that the pain is not due to ischemia, but rather from a disproportionate oxygen supply versus demand. We believe this is the first report of chronic exertional compartment syndrome with medial tibial stress syndrome in twins, raising the question of whether there is a genetic predisposition to the causation of these conditions. Copyright 2011, SLACK Incorporated.

  16. 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.

  17. 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.

  18. 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.

  19. Efficacy of subantimicrobial-dose doxycycline against nitrosative stress in chronic periodontitis.

    Science.gov (United States)

    Pârvu, Alina Elena; Alb, Sandu Florin; Crăciun, Alexandra; Taulescu, Marian Aurel

    2013-02-01

    To evaluate the effectiveness of subantimicrobial-dose doxycycline (SDD) as an adjunct to scaling and root planing (SRP) treatment against the nitrosative stress of moderate to advanced chronic periodontitis. Adults with untreated chronic periodontitis (n=174) were randomly administered SRP+SDD (n=87) (20 mg of doxycycline twice daily) or SRP+placebo (n=87) treatment for 3 months. At baseline and after 3 months, the probing depths (PD), bleeding on probing (BOP) and clinical attachment level (CAL) were measured, and a gingivomucosal biopsy was collected to assay the induction of nitric oxide synthase (iNOS) and 3-nitrotyrosine (3NT), and blood was collected to assay for total nitrites and nitrates (NO(x)) and 3NT. Compared to baseline, at the completion of treatment, significant decreases in the levels of tissue iNOS and 3NT and serum NO(x) and 3NT were observed in both groups. SRP+SDD yielded a greater reduction in the gingivomucosal and serum nitrosative stress markers than did SRP+placebo. PD, BOP, and CAL reduction were correlated with the nitrosative stress parameters. On a short-term basis, SDD therapy may be used as an adjunct to SRP treatment against nitrosative stress in moderate to advanced chronic periodontitis.

  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. Adverse effect of combination of chronic psychosocial stress and high fat diet on hippocampus-dependent memory in rats.

    Science.gov (United States)

    Alzoubi, K H; Abdul-Razzak, K K; Khabour, O F; Al-Tuweiq, G M; Alzubi, M A; Alkadhi, K A

    2009-12-01

    The combined effects of high fat diet (HFD) and chronic stress on the hippocampus-dependent spatial learning and memory were studied in rats using the radial arm water maze (RAWM). Chronic psychosocial stress and/or HFD were simultaneously administered for 3 months to young adult male Wister rats. In the RAWM, rats were subjected to 12 learning trials as well as short-term and long-term memory tests. This procedure was applied on a daily basis until the animal reaches days to criterion (DTC) in the 12th learning trial and in memory tests. DTC is the number of days that the animal takes to make zero error in two consecutive days. Groups were compared based on the number of errors per trial or test as well as on the DTC. Chronic stress, HFD and chronic stress/HFD animal groups showed impaired learning as indicated by committing significantly (Pchronic stress, HFD and chronic stress/HFD groups showed significantly impaired performance compared to control group. Additionally, the stress/HFD was the only group that showed significantly impaired performance in memory tests on the 5th training day, suggesting more severe memory impairment in that group. Furthermore, DTC value for above groups indicated that chronic stress or HFD, alone, resulted in a mild impairment of spatial memory, but the combination of chronic stress and HFD resulted in a more severe and long-lasting memory impairment. The data indicated that the combination of stress and HFD produced more deleterious effects on hippocampal cognitive function than either chronic stress or HFD alone.

  2. Effects of chronic administration of caffeine and stress on feeding behavior of rats.

    Science.gov (United States)

    Pettenuzzo, Leticia Ferreira; Noschang, Cristie; von Pozzer Toigo, Eduardo; Fachin, Andrelisa; Vendite, Deusa; Dalmaz, Carla

    2008-10-20

    Anorectic effects of caffeine are controversial in the literature, while stress and obesity are growing problems in our society. Since many stressed people are coffee drinkers, the objective of the present study was to evaluate the effect of stress and chronic administration of caffeine on feeding behavior and body weight in male and female rats. Wistar rats (both males and females) were divided into 3 groups: control (receiving water), caffeine 0.3 g/L and caffeine 1.0 g/L (in the drinking water). These groups were subdivided into non-stressed and stressed (repeated-restraint stress for 40 days). During the entire treatment, chow consumption was monitored and rats were weighed monthly. Afterwards, feeding behavior was evaluated during 3-min trials in food-deprived and ad libitum fed animals and also in repeated exposures, using palatable food (Froot Loops and Cheetos). Chronic administration of caffeine did not affect rat chow consumption or body weight gain, but diminished the consumption of both salty (Cheetos) and sweet (Froot Loops) palatable food. In the repeated trial tests, stress diminished savory snack consumption in the later exposures [I.S. Racotta, J. Leblanc, D. Richard The effect of caffeine on food intake in rats: involvement of corticotropin-releasing factor and the sympatho-adrenal system. Pharmacol Biochem Behav. 1994, 48:887-892; S.D. Comer, M. Haney, R.W. Foltin, M.W. Fischman Effects of caffeine withdrawal on humans living in a residential laboratory. Exp Clin Psychopharmacol. 1997, 5:399-403; A. Jessen, B. Buemann, S. Toubro, I.M. Skovgaard, A. Astrup The appetite-suppressant effect of nicotine is enhanced by caffeine. Diab Ob Metab. 2005, 7:327-333; J.M. Carney Effects of caffeine, theophylline and theobromine on scheduled controlled responding in rats. Br J Pharmacol. 1982, 75:451-454] and caffeine diminished consumption of both palatable foods (savory and sweet) during the early and later exposures. Most responses to caffeine were stronger

  3. Caffeine prevents cognitive impairment induced by chronic psychosocial stress and/or high fat-high carbohydrate diet.

    Science.gov (United States)

    Alzoubi, K H; Abdul-Razzak, K K; Khabour, O F; Al-Tuweiq, G M; Alzubi, M A; Alkadhi, K A

    2013-01-15

    Caffeine alleviates cognitive impairment associated with a variety of health conditions. In this study, we examined the effect of caffeine treatment on chronic stress- and/or high fat-high carbohydrate Western diet (WD)-induced impairment of learning and memory in rats. Chronic psychosocial stress, WD and caffeine (0.3 g/L in drinking water) were simultaneously administered for 3 months to adult male Wistar rats. At the conclusion of the 3 months, and while the previous treatments continued, rats were tested in the radial arm water maze (RAWM) for learning, short-term and long-term memory. This procedure was applied on a daily basis to all animals for 5 consecutive days or until the animal reaches days to criterion (DTC) in the 12th learning trial and memory tests. DTC is the number of days that the animal takes to make zero error in two consecutive days. Chronic stress and/or WD groups caused impaired learning, which was prevented by chronic caffeine administration. In the memory tests, chronic caffeine administration also prevented memory impairment during chronic stress conditions and/or WD. Furthermore, DTC value for caffeine treated stress, WD, and stress/WD groups indicated that caffeine normalizes memory impairment in these groups. These results showed that chronic caffeine administration prevented stress and/or WD-induced impairment of spatial learning and memory. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. 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 good aerobic fitness on the varied level of perceived 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.

  5. 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.

  6. The hypothalamic–pituitary–adrenal axis and sex hormones in chronic stress and obesity: pathophysiological and clinical aspects

    Science.gov (United States)

    Pasquali, Renato

    2012-01-01

    Obesity, particularly the abdominal phenotype, has been ascribed to an individual maladaptation to chronic environmental stress exposure mediated by a dysregulation of related neuroendocrine axes. Alterations in the control and action of the hypothalamic–pituitary–adrenal axis play a major role in this context, with the participation of the sympathetic nervous system. The ability to adapt to chronic stress may differ according to sex, with specific pathophysiological events leading to the development of stress-related chronic diseases. This seems to be influenced by the regulatory effects of sex hormones, particularly androgens. Stress may also disrupt the control of feeding, with some differences according to sex. Finally, the amount of experimental data in both animals and humans may help to shed more light on specific phenotypes of obesity, strictly related to the chronic exposure to stress. This challenge may potentially imply a different pathophysiological perspective and, possibly, a specific treatment. PMID:22612409

  7. 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.

  8. 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.

  9. α2-adrenergic blockade mimics the enhancing effect of chronic stress on breast cancer progression

    Science.gov (United States)

    Lamkin, Donald M.; Sung, Ha Yeon; Yang, Gyu Sik; David, John M.; Ma, Jeffrey C.Y.; Cole, Steve W.; Sloan, Erica K.

    2014-01-01

    Experimental studies in preclinical mouse models of breast cancer have shown that chronic restraint stress can enhance disease progression by increasing catecholamine levels and subsequent signaling of β-adrenergic receptors. Catecholamines also signal α-adrenergic receptors, and greater α-adrenergic signaling has been shown to promote breast cancer in vitro and in vivo. However, antagonism of α-adrenergic receptors can result in elevated catecholamine levels, which may increase β-adrenergic signaling, because pre-synaptic α2-adrenergic receptors mediate an autoinhibition of sympathetic transmission. Given these findings, we examined the effect of α-adrenergic blockade on breast cancer progression under non-stress and stress conditions (chronic restraint) in an orthotopic mouse model with MDA-MB-231HM cells. Chronic restraint increased primary tumor growth and metastasis to distant tissues as expected, and non-selective α-adrenergic blockade by phentolamine significantly inhibited those effects. However, under non-stress conditions, phentolamine increased primary tumor size and distant metastasis. Sympatho-neural gene expression for catecholamine biosynthesis enzymes was elevated by phentolamine under non-stress conditions, and the non-selective β-blocker propranolol inhibited the effect of phentolamine on breast cancer progression. Selective α2-adrenergic blockade by efaroxan also increased primary tumor size and distant metastasis under non-stress conditions, but selective α1-adrenergic blockade by prazosin did not. These results are consistent with the hypothesis that α2-adrenergic signaling can act through an autoreceptor mechanism to inhibit sympathetic catecholamine release and, thus, modulate established effects of β-adrenergic signaling on tumor progression-relevant biology. PMID:25462899

  10. Sweet food improves chronic stress-induced irritable bowel syndrome-like symptoms in rats.

    Science.gov (United States)

    Rho, Sang-Gyun; Kim, Yong Sung; Choi, Suck Chei; Lee, Moon Young

    2014-03-07

    To investigate whether palatable sweet foods have a beneficial effect on chronic stress-induced colonic motility and inflammatory cytokines. Adult male rats were divided into 3 groups: control (CON, n = 5), chronic variable stress with chow (CVS-A, n = 6), and chronic variable stress with chow and sweet food (CVS-B, n = 6). The rats were fed standard rodent chow as the chow food and/or AIN-76A as the sweet food. A food preference test for AIN-76A was performed in another group of normal rats (n = 10) for twelve days. Fecal pellet output (FPO) was measured for 6 wk during water bedding stress in the CVS groups. The weight of the adrenal glands, adrenocorticotropic hormone (ACTH) and corticosterone levels in plasma were measured. The expression levels of transforming growth factor-β, interleukin (IL)-2, and interferon-gamma (IFN-γ) were measured in the distal part of colonic tissues and plasma using Western blot analysis. In sweet preference test, all rats initially preferred sweet food to chow food. However, the consumption rate of sweet food gradually decreased and reduced to below 50% of total intake eight days after sweet food feeding. Accumulated FPO was higher in the CVS-A group compared with the CVS-B group over time. All stress groups showed significant increases in the adrenal to body weight ratio (CVS-A, 0.14 ± 0.01; CVS-B, 0.14 ± 0.01) compared with the control group (0.12 ± 0.01, P food ingestion during CVS might have an effect on the reduction of stress-induced colonic hyper-motility and pro-inflammatory cytokine production in rats.

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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.

  16. 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....... The corticosterone response to restraint seemed modified by prenatal exposure to toluene. Lactational body weight was decreased in offsprings subjected to CMS, primarily due to effects in the combined exposure group. Cognitive function was investigated in the Morris water maze, and some indications of improved...

  17. The Role of Musk in Relieving the Neurodegenerative Changes Induced After Exposure to Chronic Stress.

    Science.gov (United States)

    Abd El Wahab, Manal Galal; Ali, Soad Shaker; Ayuob, Nasra Naeim

    2018-06-01

    This study aimed to evaluate the effect induced by musk on Alzheimer's disease-such as neurodegenerative changes in mice exposed to chronic unpredictable mild stress (CUMS). Forty male Swiss albino mice were divided into 4 groups (n = 10); control, CUMS, CUMS + fluoxetine, CUMS + musk. At the end of the experiment, behavior of the mice was assessed. Serum corticosterone level, hippocampal protein level of the glucocorticoid receptors, and brain-derived neurotropic factor were also assessed. Hippocampus was histopathologically examined. Musk improved depressive status induced after exposure to CUMS as evidenced by the forced swimming and open field tests and improved the short-term memory as evidenced by the elevated plus maze test. Musk reduced both corticosterone levels and the hippocampal neurodegenerative changes observed after exposure to CUMS. These improvements were comparable to those induced by fluoxetine. Musk alleviated the memory impairment and neurodegenerative changes induced after exposure to the chronic stress.

  18. Acceleration of vertical migration of corneal epithelial cells in albino rats during chronic immobilization stress

    International Nuclear Information System (INIS)

    Timoshin, S.S.; Berezhnova, N.I.

    1986-01-01

    This paper studies the effect of chronic immobilization stress on the kinetics of corneal epithelial cells from the basal layer into higher layers. Experiments were carried out on 49 male rats. The animals were given an intraperitoneal injection of tritium-thymidine and an additional application of 5 microCi of tritium-thymidine was made to its surface because the cornea has no blood supply. The animals were killed and the cornea removed for investigation. Values of the index of labeled nuclei and intensity of thymidine labeling, characterizing DNA synthesis in the corneas of the control and experimental animals showed no significant change compared with their values in a pervious series of experiments. Chronic exposure to stress increased the velocity of vertical migration of the cells from the basal layer toward the outer layers of the cornea

  19. 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

  20. Chronic restraint stress impairs endocannabinoid mediated suppression of GABAergic signaling in the hippocampus of adult male rats.

    Science.gov (United States)

    Hu, Wen; Zhang, Mingyue; Czéh, Boldizsár; Zhang, Weiqi; Flügge, Gabriele

    2011-07-15

    Chronic stress, a risk factor for the development of psychiatric disorders, is known to induce alterations in neuronal networks in many brain areas. Previous studies have shown that chronic stress changes the expression of the cannabinoid receptor 1 (CB1) in the brains of adult rats, but neurophysiological consequences of these changes remained unclear. Here we demonstrate that chronic restraint stress causes a dysfunction in CB1 mediated modulation of GABAergic transmission in the hippocampus. Using an established protocol, adult male Sprague Dawley rats were daily restrained for 21 days and whole-cell voltage clamp was performed at CA1 pyramidal neurons. When recording carbachol-evoked inhibitory postsynaptic currents (IPSCs) which presumably originate from CB1 expressing cholecystokinin (CCK) interneurons, we found that depolarization-induced suppression of inhibition (DSI) was impaired by the stress. DSI is a form of short-term plasticity at GABAergic synapses that is known to be CB1 mediated and has been suggested to be involved in hippocampal information encoding. Chronic stress attenuated the depolarization-induced suppression of the frequency of carbachol-evoked IPSCs. Incubation with a CB1 receptor antagonist prevented this DSI effect in control but not in chronically stressed animals. The stress-induced impairment of CB1-mediated short-term plasticity at GABAergic synapses may underlie cognitive deficits which are commonly observed in animal models of stress as well as in patients with stress-related psychiatric disorders. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Increased oxidative stress in asymptomatic current chronic smokers and GOLD stage 0 COPD

    OpenAIRE

    Rytilä, Paula; Rehn, Tiina; Ilumets, Helen; Rouhos, Annamari; Sovijärvi, Anssi; Myllärniemi, Marjukka; Kinnula, Vuokko L

    2006-01-01

    Abstract Background Chronic obstructive pulmonary disease (COPD) is associated with increased oxidative and nitrosative stress. The aim of our study was to assess the importance of these factors in the airways of healthy smokers and symptomatic smokers without airway obstruction, i.e. individuals with GOLD stage 0 COPD. Methods Exhaled NO (FENO) and induced sputum samples were collected from 22 current smokers (13 healthy smokers without any respiratory symptoms and 9 with symptoms i.e. stage...

  2. 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

  3. Adrenocortical and behavioural response to chronic restraint stress in neurokinin-1 receptor knockout mice.

    Science.gov (United States)

    Delgado-Morales, Raúl; del Río, Eva; Gómez-Román, Almudena; Bisagno, Verónica; Nadal, Roser; de Felipe, Carmen; Armario, Antonio

    2012-02-01

    Brain substance P and its receptor (neurokinin-1, NK1) have a widespread brain distribution and are involved in an important number of behavioural and physiological responses to emotional stimuli. However, the role of NK1 receptors in the consequences of exposure to chronic stress has not been explored. The present study focused on the role of these receptors in the hypothalamic-pituitary-adrenal (HPA) response to daily repeated restraint stress (evaluated by plasma corticosterone levels), as well as on the effect of this procedure on anxiety-like behaviour, spatial learning and memory in the Morris water maze (MWM), a hippocampus-dependent task. Adult null mutant NK1-/- mice, with a C57BL/6J background, and the corresponding wild-type mice showed similar resting corticosterone levels and, also, did not differ in corticosterone response to a first restraint. Nevertheless, adaptation to the repeated stressor was faster in NK1-/- mice. Chronic restraint modestly increased anxiety-like behaviour in the light-dark test, irrespective of genotype. Throughout the days of the MWM trials, NK1-/- mice showed a similar learning rate to that of wild-type mice, but had lower levels of thigmotaxis and showed a better retention in the probe trial. Chronic restraint stress did not affect these variables in either genotype. These results indicate that deletion of the NK1 receptor does not alter behavioural susceptibility to chronic repeated stress in mice, but accelerates adaptation of the HPA axis. In addition, deletion may result in lower levels of thigmotaxis and improved short-term spatial memory, perhaps reflecting a better learning strategy in the MWM. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. 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.

  5. 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)

  6. 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.

  7. 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.

  8. 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.

  9. Effect of chronic exposure to aspartame on oxidative stress in the brain of albino rats.

    Science.gov (United States)

    Iyyaswamy, Ashok; Rathinasamy, Sheeladevi

    2012-09-01

    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 investigate whether chronic aspartame (75 mg/kg) administration could release methanol and induce oxidative stress in the rat brain. To mimic the human methanol metabolism, methotrexate (MTX)-treated rats were included to study the aspartame effects. Wistar strain male albino rats were administered with aspartame orally and studied along with controls and MTX-treated controls. The blood methanol level was estimated, the animal was sacrificed and the free radical changes were observed in brain discrete regions by assessing the scavenging enzymes, reduced glutathione, lipid peroxidation (LPO) and protein thiol levels. It was observed that there was a significant increase in LPO levels, superoxide dismutase (SOD) activity, GPx levels and CAT activity with a significant decrease in GSH and protein thiol. Moreover, the increases in some of these enzymes were region specific. Chronic exposure of aspartame resulted in detectable methanol in blood. Methanol per se and its metabolites may be responsible for the generation of oxidative stress in brain regions.

  10. Effect of desiccation on the dynamics of genome-wide DNA methylation in orthodox seeds of Acer platanoides L.

    Science.gov (United States)

    Plitta, Beata P; Michalak, Marcin; Bujarska-Borkowska, Barbara; Barciszewska, Mirosława Z; Barciszewski, Jan; Chmielarz, Paweł

    2014-12-01

    5-methylcytosine, an abundant epigenetic mark, plays an important role in the regulation of plant growth and development, but there is little information about stress-induced changes in DNA methylation in seeds. In the present study, changes in a global level of m5C were measured in orthodox seeds of Acer platanoides L. during seed desiccation from a WC of 1.04 to 0.05-0.06 g H2O g g(-1) dry mass (g g(-1)). Changes in the level of DNA methylation were measured using 2D TLC e based method. Quality of desiccated seeds was examined by germination and seedling emergence tests. Global m5C content (R2)increase was observed in embryonic axes isolated from seeds collected at a high WC of 1.04 g g(-1) after their desiccation to significantly lower WC of 0.17 and 0.19 g g(-1). Further desiccation of these seeds to a WC of 0.06 g g(-1), however, resulted in a significant DNA demethylation to R2 ¼ 11.52-12.22%. Similar m5C decrease was observed in seeds which undergo maturation drying on the tree and had four times lower initial WC of 0.27 g g(-1) at the time of harvest, as they were dried to a WC of 0.05 g g(-1). These data confirm that desiccation induces changes in seed m5C levels. Results were validated by seed lots derived from tree different A. platanoides provenances. It is plausible that sine wave-like alterations in m5C amount may represent a specific response of orthodox seeds to drying and play a relevant role in desiccation tolerance in seeds.

  11. 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.

  12. 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.

  13. A Trigger for Opioid Misuse: Chronic Pain and Stress Dysregulate the Mesolimbic Pathway and Kappa Opioid System.

    Science.gov (United States)

    Massaly, Nicolas; Morón, Jose A; Al-Hasani, Ream

    2016-01-01

    Pain and stress are protective mechanisms essential in avoiding harmful or threatening stimuli and ensuring survival. Despite these beneficial roles, chronic exposure to either pain or stress can lead to maladaptive hormonal and neuronal modulations that can result in chronic pain and a wide spectrum of stress-related disorders including anxiety and depression. By inducing allostatic changes in the mesolimbic dopaminergic pathway, both chronic pain and stress disorders affect the rewarding values of both natural reinforcers, such as food or social interaction, and drugs of abuse. Despite opioids representing the best therapeutic strategy in pain conditions, they are often misused as a result of these allostatic changes induced by chronic pain and stress. The kappa opioid receptor (KOR) system is critically involved in these neuronal adaptations in part through its control of dopamine release in the nucleus accumbens. Therefore, it is likely that changes in the kappa opioid system following chronic exposure to pain and stress play a key role in increasing the misuse liability observed in pain patients treated with opioids. In this review, we will discuss how chronic pain and stress-induced pathologies can affect mesolimbic dopaminergic transmission, leading to increased abuse liability. We will also assess how the kappa opioid system may underlie these pathological changes.

  14. A trigger for opioid misuse: Chronic pain and stress dysregulate the mesolimbic pathway and kappa opioid system

    Directory of Open Access Journals (Sweden)

    Nicolas Massaly

    2016-11-01

    Full Text Available Pain and stress are protective mechanisms essential in avoiding harmful or threatening stimuli and ensuring survival. Despite these beneficial roles, chronic exposure to either pain or stress can lead to maladaptive hormonal and neuronal modulations that can result in chronic pain and a wide spectrum of stress-related disorders including anxiety and depression. By inducing allostatic changes in the mesolimbic dopaminergic pathway, both chronic pain and stress disorders affect the rewarding values of both natural reinforcers, such as food or social interaction, and drugs of abuse. Despite opioids representing the best therapeutic strategy in acute pain conditions, they are often misused as a result of these allostatic changes induced by chronic pain and stress. The kappa opioid receptor system is critically involved in these neuronal adaptations in part through its control of dopamine release in the nucleus accumbens. Therefore, it is likely that changes in the kappa opioid system following chronic exposure to pain and stress play a key role in increasing the misuse liability observed in pain patients treated with opioids. In this review, we will discuss how chronic pain and stress-induced pathologies can affect mesolimbic dopaminergic transmission, leading to increased abuse liability. We will also assess how the kappa opioid system may underlie these pathological changes.

  15. Heart Rate Variability as an Indicator of Chronic Stress Caused by Lameness in Dairy Cows.

    Directory of Open Access Journals (Sweden)

    Levente Kovács

    Full Text Available Most experimental studies on animal stress physiology have focused on acute stress, while chronic stress, which is also encountered in intensive dairy cattle farming--e.g. in case of lameness--, has received little attention. We investigated heart rate (HR and heart rate variability (HRV as indicators of the autonomic nervous system activity and fecal glucocorticoid concentrations as the indicator of the hypothalamic-pituitary-adrenal axis activity in lame (with locomotion scores 4 and 5; n = 51 and non-lame (with locomotion scores 1 and 2; n = 52 Holstein-Friesian cows. Data recorded during the periods of undisturbed lying--representing baseline cardiac activity--were involved in the analysis. Besides linear analysis methods of the cardiac inter-beat interval (time-domain geometric, frequency domain and Poincaré analyses non-linear HRV parameters were also evaluated. With the exception of standard deviation 1 (SD1, all HRV indices were affected by lameness. Heart rate was lower in lame cows than in non-lame ones. Vagal tone parameters were higher in lame cows than in non-lame animals, while indices of the sympathovagal balance reflected on a decreased sympathetic activity in lame cows. All geometric and non-linear HRV measures were lower in lame cows compared to non-lame ones suggesting that chronic stress influenced linear and non-linear characteristics of cardiac function. Lameness had no effect on fecal glucocorticoid concentrations. Our results demonstrate that HRV analysis is a reliable method in the assessment of chronic stress, however, it requires further studies to fully understand the elevated parasympathetic and decreased sympathetic tone in lame animals.

  16. 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

  17. Chronic Stress in Young German Adults: Who Is Affected? A Prospective Cohort Study

    Directory of Open Access Journals (Sweden)

    Ronald Herrera

    2017-10-01

    Full Text Available 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.

  18. 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 

  19. 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.

  20. [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.

  1. [Correlations of central nervous system and thyroid function under chronic emotional stress].

    Science.gov (United States)

    Amiragova, M G; Arkhangel'skaia, M I

    1982-06-01

    Experiments on cats exposed to chronic emotional stress induced during one week by 4-hour immobilization of the animals in conjunction with aperiodic electrocutaneous stimulation were made to study correlations of the time course of changes in the EEG of the cortical and subcortical structures and the content of thyroxin in the peripheral blood at varying time of the experiments. It was demonstrated that in the course of stress, the EEG manifests the cycles of "burst" activity of slow waves, which are first recorded in the posterior hypothalamus and then get generalized. This is accompanied by a significantly high thyroxin secretion. As the stress exposures are repeated, the EEG changes become dominant, also corresponding with high thyroxin secretion. After the experiments are over, the cycles of "burst" activity accompanied by enhanced thyroid function are still recordable over several days.

  2. Chronic vitamin C deficiency does not accelerate oxidative stress in ageing brains of guinea pigs

    DEFF Research Database (Denmark)

    Tveden-Nyborg, Pernille; Andersen, Stine Hasselholt; 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...

  3. 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.

  4. 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

  5. Chronic plus binge ethanol feeding induces myocardial oxidative stress, mitochondrial and cardiovascular dysfunction, and steatosis.

    Science.gov (United States)

    Matyas, Csaba; Varga, Zoltan V; Mukhopadhyay, Partha; Paloczi, Janos; Lajtos, Tamas; Erdelyi, Katalin; Nemeth, Balazs T; Nan, Mintong; Hasko, Gyorgy; Gao, Bin; Pacher, Pal

    2016-06-01

    Alcoholic cardiomyopathy in humans develops in response to chronic excessive alcohol consumption; however, good models of alcohol-induced cardiomyopathy in mice are lacking. Herein we describe mouse models of alcoholic cardiomyopathies induced by chronic and binge ethanol (EtOH) feeding and characterize detailed hemodynamic alterations, mitochondrial function, and redox signaling in these models. Mice were fed a liquid diet containing 5% EtOH for 10, 20, and 40 days (d) combined with single or multiple EtOH binges (5 g/kg body wt). Isocalorically pair-fed mice served as controls. Left ventricular (LV) function and morphology were assessed by invasive pressure-volume conductance approach and by echocardiography. Mitochondrial complex (I, II, IV) activities, 3-nitrotyrosine (3-NT) levels, gene expression of markers of oxidative stress (gp91phox, p47phox), mitochondrial biogenesis (PGC1α, peroxisome proliferator-activated receptor α), and fibrosis were examined. Cardiac steatosis and fibrosis were investigated by histological/immunohistochemical methods. Chronic and binge EtOH feeding (already in 10 days EtOH plus single binge group) was characterized by contractile dysfunction (decreased slope of end-systolic pressure-volume relationship and preload recruitable stroke work), impaired relaxation (decreased time constant of LV pressure decay and maximal slope of systolic pressure decrement), and vascular dysfunction (impaired arterial elastance and lower total peripheral resistance). This was accompanied by enhanced myocardial oxidative/nitrative stress (3-NT; gp91phox; p47phox; angiotensin II receptor, type 1a) and deterioration of mitochondrial complex I, II, IV activities and mitochondrial biogenesis, excessive cardiac steatosis, and higher mortality. Collectively, chronic plus binge EtOH feeding in mice leads to alcohol-induced cardiomyopathies (National Institute on Alcohol Abuse and Alcoholism models) characterized by increased myocardial oxidative

  6. 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.

  7. 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

  8. CHRONIC ALCOHOL NEUROADAPTATION AND STRESS CONTRIBUTE TO SUSCEPTIBILITY FOR ALCOHOL CRAVING AND RELAPSE

    Science.gov (United States)

    BREESE, GEORGE R.; SINHA, RAJITA; HEILIG, MARKUS

    2010-01-01

    Alcoholism is a chronic relapsing disorder. Major characteristics observed in alcoholics during an initial period of alcohol abstinence are altered physiological functions and a negative emotional state. Evidence suggests that a persistent, cumulative adaptation involving a kindling/allostasis-like process occurs during the course of repeated chronic alcohol exposures that is critical for the negative symptoms observed during alcohol withdrawal. Basic studies have provided evidence for specific neurotransmitters within identified brain sites being responsible for the negative emotion induced by the persistent cumulative adaptation following intermittent-alcohol exposures. After an extended period of abstinence, the cumulative alcohol adaptation increases susceptibility to stress- and alcohol cue-induced negative symptoms and alcohol seeking, both of which can facilitate excessive ingestion of alcohol. In the alcoholic, stressful imagery and alcohol cues alter physiological responses, enhance negative emotion, and induce craving. Brain fMRI imaging following stress and alcohol cues has documented neural changes in specific brain regions of alcoholics not observed in social drinkers. Such altered activity in brain of abstinent alcoholics to stress and alcohol cues is consistent with a continuing ethanol adaptation being responsible. Therapies in alcoholics found to block responses to stress and alcohol cues would presumably be potential treatments by which susceptibility for continued alcohol abuse can be reduced. By continuing to define the neurobiological basis of the sustained alcohol adaptation critical for the increased susceptibility of alcoholics to stress and alcohol cues that facilitate craving, a new era is expected to evolve in which the high rate of relapse in alcoholism is minimized. 250 PMID:20951730

  9. 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.

  10. 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

    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......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...

  11. Neuroprotective mechanism of losartan and its interaction with nimesulide against chronic fatigue stress.

    Science.gov (United States)

    Kumar, Anil; Singh, Barinder; Mishra, Jitendriya; Sah, Sangeeta Pilkhwal; Pottabathini, Raghavender

    2015-12-01

    Potential role of angiotensin-II and cyclooxygenase have been suggested in the pathophysiology of chronic fatigue stress. The present study has been designed to evaluate the neuroprotective effect of losartan and its interaction with nimesulide against chronic fatigue stress and related complications in mice. In the present study, male Laca mice (20-30 g) were subjected to running wheel activity test session (RWATS) for 6 min daily for 21 days. Losartan, nimesulide and their combinations were administered daily for 21 days, 45 min before being subjected to RWATS. Various behavioral and biochemical and neuroinflammatory mediators were assessed subsequently. 21 days RWATS treatment significantly decreased number of wheel rotations/6 min indicating fatigue stress like behaviors as compared to naive group. 21 days treatment with losartan (10 and 20 mg/kg, ip), nimesulide (5 and 10 mg/kg, po) and their combinations significantly improved behavior [increased number of wheel rotations, reversal of post-exercise fatigue, locomotor activity, antianxiety-like behavior (number of entries, latency to enter and time spent in mirror chamber), and memory performance (transfer latency in plus-maze performance task)], biochemical parameters (reduced serum corticosterone, brain lipid peroxidation, nitrite concentration, acetylcholinesterase activity, restored reduced glutathione levels and catalase activity) as compared to RWATS control. Besides, TNF-α, CRP levels were significantly attenuated by these drugs and their combinations as compared to control. The present study highlights the role of cyclooxygenase modulation in the neuroprotective effect of losartan against chronic fatigue stress-induced behavioral, biochemical and cellular alterations in mice.

  12. Effect of Inhaling Bergamot Oil on Depression-Related Behaviors in Chronic Stressed Rats.

    Science.gov (United States)

    Saiyudthong, Somrudee; Mekseepralard, Chantana

    2015-10-01

    Bergamot essential oil (BEO) possesses sedation and anxiolytic properties similar to diazepam. After long period of exposure to stressors, including restrained stress, depressive-like behavior can be produced. BEO has been suggested to reduce depression. However, there is no scientific evidence supporting this property. To investigate the effect of BEO in chronic stressed rats on: 1) behavior related depressive disorder, 2) hypothalamic pituitary adrenal (HPA) axis response, and iii) brain-derived neurotrophic factor (BDNF) protein levels in hippocampus. Male Wistar rats, weighing 200 to 250 g, were induced chronic restrained stress 15 minutes dailyfor two weeks. For the next two weeks, these rats were divided intofour groups, control-i.p., fluoxetine-i.p., control-inhale, and BEO-inhale. Fluoxetine (10 mg/kg i.p.) or saline was intraperitoneally administered daily while 2.5% BEO or saline was inhaled daily. At the end of the treatment, rats were assessed for depressive-like behavior using the forced swimming test (FST). After the behavioral test, the animals were immediately decapitated and trunk blood samples were collected for the measurement ofcorticosterone and adrenocorticotropic hormone (ACTH) levels and hippocampus was dissected and stored in afreezer at -80 °C until assay for BDNF protein. BEO andfluoxetine significantly decreased the immobility time in the FST (p BDNF protein determination, neither BEO norfluoxetine had any effect on BDNF protein levels in hippocampus compared to their controls. The inhalation ofBEO decrease behavior related depressive disorder similar tofluoxetine but has no effect on HPA axis response and BDNF protein levels in chronic restrained stress.

  13. Clonidine reduces norepinephrine and improves bone marrow function in a rodent model of lung contusion, hemorrhagic shock, and chronic stress.

    Science.gov (United States)

    Alamo, Ines G; Kannan, Kolenkode B; Ramos, Harry; Loftus, Tyler J; Efron, Philip A; Mohr, Alicia M

    2017-03-01

    Propranolol has been shown previously to restore bone marrow function and improve anemia after lung contusion/hemorrhagic shock. We hypothesized that daily clonidine administration would inhibit central sympathetic outflow and restore bone marrow function in our rodent model of lung contusion/hemorrhagic shock with chronic stress. Male Sprague-Dawley rats underwent 6 days of restraint stress after lung contusion/hemorrhagic shock during which the animals received clonidine (75 μg/kg) after the restraint stress. On postinjury day 7, we assessed urine norepinephrine, blood hemoglobin, plasma granulocyte colony stimulating factor, and peripheral blood mobilization of hematopoietic progenitor cells, as well as bone marrow cellularity and erythroid progenitor cell growth. The addition of clonidine to lung contusion/hemorrhagic shock with chronic restraint stress significantly decreased urine norepinephrine levels, improved bone marrow cellularity, restored erythroid progenitor colony growth, and improved hemoglobin (14.1 ± 0.6 vs 10.8 ± 0.6 g/dL). The addition of clonidine to lung contusion/hemorrhagic shock with chronic restraint stress significantly decreased hematopoietic progenitor cells mobilization and restored granulocyte colony stimulating factor levels. After lung contusion/hemorrhagic shock with chronic restraint stress, daily administration of clonidine restored bone marrow function and improved anemia. Alleviating chronic stress and decreasing norepinephrine is a key therapeutic target to improve bone marrow function after severe injury. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Desiccant Dewpoint Cooling System Independent of External Water Sources

    DEFF Research Database (Denmark)

    Bellemo, Lorenzo; Elmegaard, Brian; Markussen, Wiebke B.

    2015-01-01

    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...... to the desiccant dew-point system without water recovery, the required regeneration temperature increases and the system thermal efficiency decreases....

  15. Death by desiccation: Effects of hermetic storage on cowpea bruchids

    KAUST Repository

    Murdock, Larry L.; Margam, Venu; Baoua, Ibrahim B.; Balfe, Susan; Shade, Richard E.

    2012-01-01

    't reproduce. As a result, population growth ceases and damaging infestations don't develop. . C. maculatus eggs, larvae, and pupae subjected to hypoxia eventually die after exposures of various duration. The cause of death is desiccation resulting from

  16. Extended effect of chronic social defeat stress in childhood on behaviors in adulthood.

    Directory of Open Access Journals (Sweden)

    Irina L Kovalenko

    Full Text Available Individuals exposed to social stress in childhood are more predisposed to developing psychoemotional disorders in adulthood. Here we use an animal model to determine the influence of hostile social environment in adolescence on behavior during adult life. One-month-old adolescent male mice were placed for 2 weeks in a common cage with an adult aggressive male. Animals were separated by a transparent perforated partition, but the adolescent male was exposed daily to short attacks from the adult male. After exposure to social stress, some of the adolescent mice were placed for 3 weeks in comfortable conditions. Following this rest period, stressed young males and adult males were studied in a range of behavioral tests to evaluate the levels of anxiety, depressiveness, and communicativeness with an unfamiliar partner. In addition, adult mice exposed to social stress in adolescence were engaged in agonistic interactions. We found that 2 weeks of social stress result in a decrease of communicativeness in the home cage and diminished social interactions on the novel territory. Stressed adolescents demonstrated a high level of anxiety in the elevated plus-maze test and helplessness in the Porsolt test. Furthermore, the number of dividing (BrdU-positive cells in the subgranular zone of the dentate gyrus was significantly lower in stressed adolescents. After 3 weeks of rest, most behavioral characteristics in different tests, as well as the number of BrdU-positive cells in the hippocampus, did not differ from those of the respective control mice. However, the level of anxiety remained high in adult males exposed to chronic social stress in childhood. Furthermore, these males were more aggressive in the agonistic interactions. Thus, hostile social environment in adolescence disturbs psychoemotional state and social behaviors of animals in adult life.

  17. Extended Effect of Chronic Social Defeat Stress in Childhood on Behaviors in Adulthood

    Science.gov (United States)

    Kovalenko, Irina L.; Galyamina, Anna G.; Smagin, Dmitry A.; Michurina, Tatyana V.; Kudryavtseva, Natalia N.; Enikolopov, Grigori

    2014-01-01

    Individuals exposed to social stress in childhood are more predisposed to developing psychoemotional disorders in adulthood. Here we use an animal model to determine the influence of hostile social environment in adolescence on behavior during adult life. One-month-old adolescent male mice were placed for 2 weeks in a common cage with an adult aggressive male. Animals were separated by a transparent perforated partition, but the adolescent male was exposed daily to short attacks from the adult male. After exposure to social stress, some of the adolescent mice were placed for 3 weeks in comfortable conditions. Following this rest period, stressed young males and adult males were studied in a range of behavioral tests to evaluate the levels of anxiety, depressiveness, and communicativeness with an unfamiliar partner. In addition, adult mice exposed to social stress in adolescence were engaged in agonistic interactions. We found that 2 weeks of social stress result in a decrease of communicativeness in the home cage and diminished social interactions on the novel territory. Stressed adolescents demonstrated a high level of anxiety in the elevated plus-maze test and helplessness in the Porsolt test. Furthermore, the number of dividing (BrdU-positive) cells in the subgranular zone of the dentate gyrus was significantly lower in stressed adolescents. After 3 weeks of rest, most behavioral characteristics in different tests, as well as the number of BrdU-positive cells in the hippocampus, did not differ from those of the respective control mice. However, the level of anxiety remained high in adult males exposed to chronic social stress in childhood. Furthermore, these males were more aggressive in the agonistic interactions. Thus, hostile social environment in adolescence disturbs psychoemotional state and social behaviors of animals in adult life. PMID:24667609

  18. 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.

  19. Decreased hedonic responsiveness following chronic mild stress is not secondary to loss of body weight.

    Science.gov (United States)

    Willner, P; Moreau, J L; Nielsen, C K; Papp, M; Sluzewska, A

    1996-07-01

    Chronic exposure to mild unpredictable stress (CMS) has previously been found to decrease hedonic responsiveness, as measured by the consumption of palatable sweet solutions or sensitivity to brain stimulation reward. These effects are reversed by chronic treatment with antidepressant drugs, and the CMS procedure has been proposed as a relatively valid animal model of depression. It has recently been suggested that the behavioural effects of CMS may be secondary to loss of body weight. This article collates data from five laboratories using the CMS procedure. Data are presented from seven studies using five different rat strains, as well as CD1 mice. Three-week exposure to CMS significantly decreased sucrose consumption by Lister hooded, PVG hooded, Wistar, and Wistar WU rats, and by CD1 mice, and sensitivity to brain stimulation reward in Ibm:Ro Ro rats. Weight loss in different experiments varied between 0 and 10%. Hedonic sensitivity relative to body weight (e.g., mg sucrose/g body weight) decreased significantly in all experiments. Animals maintained on a restricted feeding regime lost weight but did not show decreases in sucrose intake. It is concluded that decreased hedonic sensitivity following chronic mild stress cannot be attributed to loss of body weight.

  20. Correlates of Cortisol in Human Hair: Implications for Epidemiologic Studies on Health Effects of Chronic Stress

    Science.gov (United States)

    Wosu, Adaeze C.; Valdimarsdóttir, Unnur; Shields, Alexandra E.; Williams, David R.; Williams, Michelle A.

    2013-01-01

    Assessment of cortisol concentrations in hair is one of the latest innovations for measuring long-term cortisol exposure. We performed a systematic review of correlates of cortisol in human hair to inform the design, analysis and interpretation of future epidemiologic studies. Relevant publications were identified through electronic searches on PubMed, WorldCat, and Web of Science using keywords, “cortisol” “hair” “confounders” “chronic” “stress” and “correlates.” Thirty-nine studies were included in this review. Notwithstanding scarce data and some inconsistencies, investigators have found hair cortisol concentrations to be associated with stress-related psychiatric symptoms and disorders (e.g., PTSD), medical conditions indicating chronic activation of the hypothalamic-pituitary-adrenal axis (e.g., Cushing´s syndrome) and other life situations associated with elevated risk of chronic stress (e.g., shiftwork). Results from some studies suggest that physical activity, adiposity, and substance abuse may be correlates of hair cortisol concentrations. In contrast to measures of short-term cortisol release (saliva, blood, and urine), cigarette smoking and use of oral contraceptives appear to not be associated with hair cortisol concentrations. Studies of pregnant women indicate increased hair cortisol concentrations across successive trimesters. The study of hair cortisol presents a unique opportunity to assess chronic alterations in cortisol concentrations in epidemiologic studies. PMID:24184029

  1. Chronic stress accelerates the development of endometriosis in mouse through adrenergic receptor β2.

    Science.gov (United States)

    Long, Qiqi; Liu, Xishi; Qi, Qiuming; Guo, Sun-Wei

    2016-11-01

    Does chronic stress in mice accelerate the development of endometriosis, and, if so, through what mechanism? Exposure to chronic stress accelerates the development of endometriosis and exacerbates the endometriosis-associated generalized hyperalgesia, most likely through activation of the adrenoceptor β2 (ADRB2) and cAMP responsive element-binding protein (CREB). Women with endometriosis tend to have higher levels of psychological stress, which is known to impact negatively on health in general and to promote tumor growth and metastasis in particular. Exposure to chronic stress before and after the induction of endometriosis is reported to increase lesion sizes in rodents, but it is unclear whether adrenoceptors are involved or not in the stress-promoted development of endometriosis. Three independent, prospective, randomized mouse experimentations. A total of 184 virgin female Balb/C mice were used. In Experiment 1, the mice were randomly divided into four groups: the control group, which received no stress; the before, after and both groups, which received immobilization stress before, after and both before and after the induction of endometriosis, respectively. In Experiment 2, mice were randomly divided into four groups one day after the induction of endometriosis: phosphate buffer saline (PBS) and propranolol (PROP) groups, which received the mini-pump containing, respectively, PBS only and propranolol (a non-selective ADRB antagonist) but no stress, STR+PROP and STR+PBS groups, which received stress and the mini-pump containing, respectively, propranolol and PBS. The immobilization stress started after the insertion of mini-pumps. In Experiment 3, mice were induced with endometriosis. Three days after the induction, they were randomly divided into four groups: control, ADRAa, ADRB2a, and ADRBa, which received the mini-pump containing solution only, metaraminol (a non-specific α adrenoceptor agonist), tebutaline (a specific ADRB2 agonist), or isoproterenol

  2. 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.

  3. THE TEAM BUILDING IN COLLECTIVES AS PREVENTIVE AND THERAPEUTIC ACTIVITY IN ACUTE AND CHRONIC STRESS

    Directory of Open Access Journals (Sweden)

    Tsvetelina Mihaylova

    2018-04-01

    Full Text Available The stress contributes to almost all medical illnesses while the acute and chronic stress - related to work - is a primary cause of such life-threatening conditions as myocardial infarction, brain stroke, etc. The aim of the current study is an investigation of the methods for team building related to prevention and therapy in connection with acute or chronic stress. The accomplishment of the aim set is achieved by means of assessment of the applicability of laughter therapy, as a method for team building suitable in practice. It was found that the laughter therapy may help reduction of stress and tension, improvement of the quality of work, strengthening of the social relations and interrelations, etc. Increasingly more studies maintain the theory that the laughter may have therapeutic value and brings about physical benefits to the particular individual, as a member of the personnel. The laughter is a part of human behavior, and it helps people to clarify their intentions in the social interaction. The laughter is used as a signal for accepting the positive interactions with other people and is a precondition for friendly attitude in the working environment as well. Conclusions may be drawn that the laughter therapy is a suitable method for team building; the laughter therapy is appropriate for everyone as a means for the alleviation of stress, and it has a positive impact on the working process. In terms of business, a positive assessment of the methods for pulling together of members of the collective (team building may be given by a way which has subsequent positive consequences on their work.

  4. Role of Tyrosine Isomers in Acute and Chronic Diseases Leading to Oxidative Stress - A Review.

    Science.gov (United States)

    Molnár, Gergő A; Kun, Szilárd; Sélley, Eszter; Kertész, Melinda; Szélig, Lívia; Csontos, Csaba; Böddi, Katalin; Bogár, Lajos; Miseta, Attila; Wittmann, István

    2016-01-01

    Oxidative stress plays a major role in the pathogenesis of a variety of acute and chronic diseases. Measurement of the oxidative stress-related end products may be performed, e.g. that of structural isomers of the physiological para-tyrosine, namely meta- and ortho-tyrosine, that are oxidized derivatives of phenylalanine. Recent data suggest that in sepsis, serum level of meta-tyrosine increases, which peaks on the 2(nd) and 3(rd) days (ptyrosine excretion correlated with both need of daily insulin dose and the insulin-glucose product in non-diabetic septic cases (ptyrosine excretion, urinary meta-tyrosine/para-tyrosine, urinary ortho-tyrosine/para-tyrosine and urinary (meta- + orthotyrosine)/ para-tyrosine proved to be markers of carbohydrate homeostasis. In a chronic rodent model, we tried to compensate the abnormal tyrosine isomers using para-tyrosine, the physiological amino acid. Rats were fed a standard high cholesterol-diet, and were given para-tyrosine or vehicle orally. High-cholesterol feeding lead to a significant increase in aortic wall meta-tyrosine content and a decreased vasorelaxation of the aorta to insulin and the glucagon-like peptide-1 analogue, liraglutide, that both could be prevented by administration of para-tyrosine. Concluding, these data suggest that meta- and ortho-tyrosine are potential markers of oxidative stress in acute diseases related to oxidative stress, and may also interfere with insulin action in septic humans. Competition of meta- and ortho-tyrosine by supplementation of para-tyrosine may exert a protective role in oxidative stress-related diseases.

  5. Ocimum basilicum improve chronic stress-induced neurodegenerative changes in mice hippocampus.

    Science.gov (United States)

    Ayuob, Nasra Naeim; El Wahab, Manal Galal Abd; Ali, Soad Shaker; Abdel-Tawab, Hanem Saad

    2018-01-22

    Alzheimer's disease (AD), one of the progressive neurodegenerative diseases might be associated with exposure to stress and altered living conditions. This study aimed to evaluate the effectiveness of Ocimum basilicum (OB) essential oils in improving the neurodegenerative-like changes induced in mice after exposed to chronic unpredictable mild stress (CUMS). Forty male Swiss albino mice divided into four groups (n = 10); the control, CUMS, CUMS + Fluoxetine, CUMS + OB were used. Behavioral tests, serum corticosterone level, hippocampus protein level of the glucocorticoid receptors (GRs) and brain-dreived neurotropic factor (BDNF) were determined after exposure to CUMS. Hippocampus was histopathologically examined. Data were analyzed using statistical package for the social sciences (SPSS) and P value of less than 0.05 was considered significant. OB diminished the depression manifestation as well as impaired short term memory observed in the mice after exposure to the CUMS as evidenced by the forced swimming and elevated plus maze test. OB also up-regulated the serum corticosterone level, hippocampal protein level of the glucocorticoid receptor and the brain-derived neurotropic factor and reduced the neurodegenerative and atrophic changes induced in the hippocampus after exposure to CUMS. Essential oils of OB alleviated the memory impairment and hippocampal neurodegenerative changes induced by exposure to the chronic unpredictable stress indicating that it is the time to test its effectiveness on patients suffering from Alzheimer disease.

  6. 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.

  7. Salivary DNA and markers of oxidative stress in patients with chronic periodontitis.

    Science.gov (United States)

    Baňasová, Lenka; Kamodyová, Natália; Janšáková, Katarína; Tóthová, Ľubomíra; Stanko, Peter; Turňa, Ján; Celec, Peter

    2015-03-01

    Previous observational studies have shown that periodontal status is associated with salivary markers of oxidative damage. A direct comparison of periodontitis patients and controls using a wide palette of salivary markers of oxidative stress is lacking. Characteristics of salivary DNA in periodontitis are unknown. The aim of this study was to compare the salivary markers of oxidative stress and characteristics of salivary DNA between patients with chronic periodontitis and periodontitis-free controls. Saliva was collected from 23 patients with chronic periodontitis and 19 periodontitis-free controls. All participants underwent a clinical periodontal examination. Markers of oxidative and carbonyl stress were measured in saliva. Human and bacterial DNA was quantified, and human DNA integrity was assessed. Salivary thiobarbituric acid-reacting substances were higher in patients than in controls; at least in men, the difference was significant (p periodontitis patients. The results confirmed the association of salivary thiobarbituric acid-reacting substances with periodontitis. Lipid peroxidation in periodontitis seems to be caused by increased production of reactive oxygen species in men and by decreased antioxidant status in women. Whether lower salivary DNA integrity is involved in the pathogenesis of periodontitis remains to be elucidated. Salivary thiobarbituric acid-reacting substances are associated with periodontitis at least on a population level. Sex-specific causes of lipid peroxidation might point towards different pathogenic mechanisms.

  8. Stress management skills, neuroimmune processes and fatigue levels in persons with chronic fatigue syndrome.

    Science.gov (United States)

    Lattie, Emily G; Antoni, Michael H; Fletcher, Mary Ann; Penedo, Frank; Czaja, Sara; Lopez, Corina; Perdomo, Dolores; Sala, Andreina; Nair, Sankaran; Fu, Shih Hua; Klimas, Nancy

    2012-08-01

    Stressors and emotional distress responses impact chronic fatigue syndrome (CFS) symptoms, including fatigue. Having better stress management skills might mitigate fatigue by decreasing emotional distress. Because CFS patients comprise a heterogeneous population, we hypothesized that the role of stress management skills in decreasing fatigue may be most pronounced in the subgroup manifesting the greatest neuroimmune dysfunction. In total, 117 individuals with CFS provided blood and saliva samples, and self-report measures of emotional distress, perceived stress management skills (PSMS), and fatigue. Plasma interleukin-1-beta (IL-1β, IL-2, IL-6, IL-10, and tumor necrosis factor-alpha (TNF-α), and diurnal salivary cortisol were analyzed. We examined relations among PSMS, emotional distress, and fatigue in CFS patients who did and did not evidence neuroimmune abnormalities. Having greater PSMS related to less fatigue (p=.019) and emotional distress (pfatigue levels most strongly in CFS patients in the top tercile of IL-6, and emotional distress mediated the relationship between PSMS and fatigue most strongly in patients with the greatest circulating levels of IL-6 and a greater inflammatory (IL-6):anti-inflammatory (IL-10) cytokine ratio. CFS patients having greater PSMS show less emotional distress and fatigue, and the influence of stress management skills on distress and fatigue appear greatest among patients who have elevated IL-6 levels. These findings support the need for research examining the impact of stress management interventions in subgroups of CFS patients showing neuroimmune dysfunction. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. 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 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.

  10. Desiccants for retrospective dosimetry using optically stimulated luminescence (OSL)

    International Nuclear Information System (INIS)

    Geber-Bergstrand, Therése; Bernhardsson, Christian; Christiansson, Maria; Mattsson, Sören; Rääf, Christopher L.

    2015-01-01

    Optically stimulated luminescence (OSL) was used to test different kinds of desiccants for their potential use in retrospective dosimetry. Desiccants are used for the purpose of absorbing liquids and can be found in a number of items which may be found in the immediate environment of a person, including hand bags, drug packages, and the vehicles of rescue service teams. Any material exhibiting OSL properties suitable for retrospective dosimetry is a useful addition to the existing dosimetry system available in emergency preparedness. Eleven kinds of desiccants were investigated in order to obtain an overview of the fundamental OSL properties necessary for retrospective dosimetry. Measurements were made using a Risø TL/OSL reader and irradiations were achieved with the 90 Sr/ 90 Y source incorporated in the reader. Several of the desiccants exhibited promising properties as retrospective dosemeters. Some of the materials exhibited a strong as-received signal, i.e. without any laboratory irradiation, but the origin of this signal has not yet been established. The minimum detectable dose ranged from 8 to 450 mGy for ten of the materials and for one material (consisting of natural clay) the minimum detectable dose was 1.8 Gy. - Highlights: • Desiccants can be used as fortuitous dosemeters using OSL. • The minimum detectable dose for processed desiccants range from 8 to 450 mGy. • The minimum detectable dose for natural clay was 1.8 Gy

  11. 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…

  12. Overexpression of mineralocorticoid receptors partially prevents chronic stress-induced reductions in hippocampal memory and structural plasticity

    NARCIS (Netherlands)

    Kanatsou, Sofia; Fearey, Brenna C.; Kuil, Laura E.; Lucassen, Paul J.; Harris, Anjanette P.; Seckl, Jonathan R.; Krugers, Harm; Joels, Marian

    2015-01-01

    Exposure to chronic stress is a risk factor for cognitive decline and psychopathology in genetically predisposed individuals. Preliminary evidence in humans suggests that mineralocorticoid receptors (MRs) may confer resilience to these stress-related changes. We specifically tested this idea using a

  13. 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 ) Healthy 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

  14. Chronic stress alters concentrations of corticosterone receptors in a tissue-specific manner in wild house sparrows (Passer domesticus).

    Science.gov (United States)

    Lattin, Christine R; Romero, L Michael

    2014-07-15

    The physiological stress response results in release of glucocorticoid hormones such as corticosterone (CORT). Whereas short-term activation of this response helps animals cope with environmental stressors, chronic activation can result in negative effects including metabolic dysregulation and reproductive failure. However, there is no consensus hormonal profile of a chronically stressed animal, suggesting that researchers may need to look beyond hormone titers to interpret the impacts of chronic stress. In this study, we brought wild house sparrows (Passer domesticus) into captivity. We then compared glucocorticoid and mineralocorticoid receptor concentrations in sparrows exposed either to a standardized chronic stress protocol (n=26) or to standard husbandry conditions (controls; n=20). We used radioligand binding assays to quantify receptors in whole brain, liver, kidneys, spleen, gonads, gastrocnemius and pectoralis muscle, omental and subcutaneous fat, and bib and back skin. In most tissues, CORT receptors did not differ between controls and stressed animals, although we found marginal increases in receptor density in kidney and testes in stressed birds at some time points. Only in pectoralis muscle was there a robust effect of chronic stress, with both receptor types higher in stressed animals. Increased pectoralis sensitivity to CORT with chronic stress may be part of the underlying mechanism for muscle wasting in animals administered exogenous CORT. Furthermore, the change in pectoralis was not paralleled by gastrocnemius receptors. This difference may help explain previous reports of a greater effect of CORT on pectoralis than on other muscle types, and indicate that birds use this muscle as a protein reserve. © 2014. Published by The Company of Biologists Ltd.

  15. Chronic stress and peripheral pain: Evidence for distinct, region-specific changes in visceral and somatosensory pain regulatory pathways.

    Science.gov (United States)

    Zheng, Gen; Hong, Shuangsong; Hayes, John M; Wiley, John W

    2015-11-01

    Chronic stress alters the hypothalamic-pituitary-adrenal (HPA) axis and enhances visceral and somatosensory pain perception. It is unresolved whether chronic stress has distinct effects on visceral and somatosensory pain regulatory pathways. Previous studies reported that stress-induced visceral hyperalgesia is associated with reciprocal alterations of endovanilloid and endocannabinoid pain pathways in DRG neurons innervating the pelvic viscera. In this study, we compared somatosensory and visceral hyperalgesia with respect to differential responses of peripheral pain regulatory pathways in a rat model of chronic, intermittent stress. We found that chronic stress induced reciprocal changes in the endocannabinoid 2-AG (increased) and endocannabinoid degradation enzymes COX-2 and FAAH (decreased), associated with down-regulation of CB1 and up-regulation of TRPV1 receptors in L6-S2 DRG but not L4-L5 DRG neurons. In contrast, sodium channels Nav1.7 and Nav1.8 were up-regulated in L4-L5 but not L6-S2 DRGs in stressed rats, which was reproduced in control DRGs treated with corticosterone in vitro. The reciprocal changes of CB1, TRPV1 and sodium channels were cell-specific and observed in the sub-population of nociceptive neurons. Behavioral assessment showed that visceral hyperalgesia persisted, whereas somatosensory hyperalgesia and enhanced expression of Nav1.7 and Nav1.8 sodium channels in L4-L5 DRGs normalized 3 days after completion of the stress phase. These data indicate that chronic stress induces visceral and somatosensory hyperalgesia that involves differential changes in endovanilloid and endocannabinoid pathways, and sodium channels in DRGs innervating the pelvic viscera and lower extremities. These results suggest that chronic stress-induced visceral and lower extremity somatosensory hyperalgesia can be treated selectively at different levels of the spinal cord. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Trauma and posttraumatic stress disorder in women with chronic pelvic pain.

    Science.gov (United States)

    Meltzer-Brody, Samantha; Leserman, Jane; Zolnoun, Denniz; Steege, John; Green, Emily; Teich, Alice

    2007-04-01

    To examine the effect of abuse history, other major trauma, and posttraumatic stress disorder (PTSD) on medical symptoms and health-related daily functioning in women with chronic pelvic pain. We administered a questionnaire to 713 consecutive women seen in a referral-based pelvic pain clinic. We found that 46.8% reported having either a sexual or physical abuse history. A total of 31.3% had a positive screen for PTSD. Using regression and path analysis, controlling for demographic variables, we found that a trauma history was associated with worse daily physical functioning due to poor health (Pscreen for PTSD was highly related to most measures of poor health status (Pscreening for trauma and PTSD in women with chronic pelvic pain. II.

  17. 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.

  18. Omega-3 polyunsaturated fatty acids and chronic stress-induced modulations of glutamatergic neurotransmission in the hippocampus.

    Science.gov (United States)

    Hennebelle, Marie; Champeil-Potokar, Gaëlle; Lavialle, Monique; Vancassel, Sylvie; Denis, Isabelle

    2014-02-01

    Chronic stress causes the release of glucocorticoids, which greatly influence cerebral function, especially glutamatergic transmission. These stress-induced changes in neurotransmission could be counteracted by increasing the dietary intake of omega-3 polyunsaturated fatty acids (n-3 PUFAs). Numerous studies have described the capacity of n-3 PUFAs to help protect glutamatergic neurotransmission from damage induced by stress and glucocorticoids, possibly preventing the development of stress-related disorders such as depression or anxiety. The hippocampus contains glucocorticoid receptors and is involved in learning and memory. This makes it particularly sensitive to stress, which alters certain aspects of hippocampal function. In this review, the various ways in which n-3 PUFAs may prevent the harmful effects of chronic stress, particularly the alteration of glutamatergic synapses in the hippocampus, are summarized. © 2014 International Life Sciences Institute.

  19. 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.

  20. Emotionality Modulates the Effect of Chronic Stress on Feeding Behaviour in Birds

    Science.gov (United States)

    Favreau-Peigné, Angélique; Calandreau, Ludovic; Constantin, Paul; Gaultier, Bernard; Bertin, Aline; Arnould, Cécile; Laurence, Agathe; Richard-Yris, Marie-Annick; Houdelier, Cécilia; Lumineau, Sophie; Boissy, Alain; Leterrier, Christine

    2014-01-01

    Chronic stress is a long-lasting negative emotional state that induces negative consequences on animals’ psycho-physiological state. This study aimed at assessing whether unpredictable and repeated negative stimuli (URNS) influence feeding behaviour in quail. Sixty-four quail were exposed to URNS from day 17 to 40, while 64 quail were undisturbed. Two lines divergently selected on their inherent emotionality were used to assess the effect of genetic factors on the sensitivity to URNS. All quail were submitted to a sequential feeding procedure (using two diets of different energetic values) which placed them in a contrasting situation. Behavioural tests were performed to assess the emotional reactivity of the two lines. Results confirmed that differences exist between them and that their emotional reactivity was enhanced by URNS. Diet preferences, motivation and daily intake were also measured. URNS did not change the preferences for the hypercaloric diet compared to the hypocaloric diet in choice tests, but they reduced daily intakes in both lines. Motivations for each diet were differently affected by URNS: they decreased the motivation to eat the hypercaloric diet in quail selected for their low inherent fearfulness whereas they increased the motivation to eat the hypocaloric diet in quail selected for their high inherent fearfulness, which suggested a devaluation process in the former and a compensatory behaviour in the later. Growth was furthermore reduced and laying delayed by URNS in both lines. In conclusion, the exposure to URNS induced interesting changes in feeding behaviour added with an increase in emotional reactivity and an alteration of production parameters. This confirms that both lines of quail experienced a chronic stress state. However differences in feed motivation and emotional reactivity between lines under chronic stress suggested that they experienced different emotional state and use different ways to cope with it depending on their

  1. Emotionality modulates the effect of chronic stress on feeding behaviour in birds.

    Directory of Open Access Journals (Sweden)

    Angélique Favreau-Peigné

    Full Text Available Chronic stress is a long-lasting negative emotional state that induces negative consequences on animals' psycho-physiological state. This study aimed at assessing whether unpredictable and repeated negative stimuli (URNS influence feeding behaviour in quail. Sixty-four quail were exposed to URNS from day 17 to 40, while 64 quail were undisturbed. Two lines divergently selected on their inherent emotionality were used to assess the effect of genetic factors on the sensitivity to URNS. All quail were submitted to a sequential feeding procedure (using two diets of different energetic values which placed them in a contrasting situation. Behavioural tests were performed to assess the emotional reactivity of the two lines. Results confirmed that differences exist between them and that their emotional reactivity was enhanced by URNS. Diet preferences, motivation and daily intake were also measured. URNS did not change the preferences for the hypercaloric diet compared to the hypocaloric diet in choice tests, but they reduced daily intakes in both lines. Motivations for each diet were differently affected by URNS: they decreased the motivation to eat the hypercaloric diet in quail selected for their low inherent fearfulness whereas they increased the motivation to eat the hypocaloric diet in quail selected for their high inherent fearfulness, which suggested a devaluation process in the former and a compensatory behaviour in the later. Growth was furthermore reduced and laying delayed by URNS in both lines. In conclusion, the exposure to URNS induced interesting changes in feeding behaviour added with an increase in emotional reactivity and an alteration of production parameters. This confirms that both lines of quail experienced a chronic stress state. However differences in feed motivation and emotional reactivity between lines under chronic stress suggested that they experienced different emotional state and use different ways to cope with it

  2. 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). 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)

  3. Chronic psychosocial stress disturbs long-bone growth in adolescent mice

    Directory of Open Access Journals (Sweden)

    Sandra Foertsch

    2017-12-01

    Full Text Available Although a strong association between psychiatric and somatic disorders is generally accepted, little is known regarding the interrelationship between mental and skeletal health. Although depressive disorders have been shown to be strongly associated with osteoporosis and increased fracture risk, evidence from post-traumatic stress disorder (PTSD patients is less consistent. Therefore, the present study investigated the influence of chronic psychosocial stress on bone using a well-established murine model for PTSD. C57BL/6N mice (7 weeks old were subjected to chronic subordinate colony housing (CSC for 19 days, whereas control mice were singly housed. Anxiety-related behavior was assessed in the open-field/novel-object test, after which the mice were euthanized to assess endocrine and bone parameters. CSC mice exhibited increased anxiety-related behavior in the open-field/novel-object test, increased adrenal and decreased thymus weights, and unaffected plasma morning corticosterone. Microcomputed tomography and histomorphometrical analyses revealed significantly reduced tibia and femur lengths, increased growth-plate thickness and reduced mineral deposition at the growth plate, suggesting disturbed endochondral ossification during long-bone growth. This was associated with reduced Runx2 expression in hypertrophic chondrocytes in the growth plate. Trabecular thicknesses and bone mineral density were significantly increased in CSC compared to singly housed mice. Tyrosine hydroxylase expression was increased in bone marrow cells located at the growth plates of CSC mice, implying that local adrenergic signaling might be involved in the effects of CSC on the skeletal phenotype. In conclusion, chronic psychosocial stress negatively impacts endochondral ossification in the growth plate, affecting both longitudinal and appositional bone growth in adolescent mice.

  4. 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.

  5. Combat-related, chronic posttraumatic stress disorder: implications for group-therapy intervention.

    Science.gov (United States)

    Makler, S; Sigal, M; Gelkopf, M; Kochba, B B; Horeb, E

    1990-07-01

    The patient with combat-related chronic Posttraumatic Stress Disorder suffers from a wide spectrum of maladaptive behaviors. This paper delineates the work that has been done with such a population in group therapy. The plan that is proposed takes into account three interrelated sets of factors: factors important for creating an effective working relation; curative factors; and particular themes. Each of these factors is analyzed in the light of the particularities of group work with such a population. Each of the points discussed is based upon the relevant literature, upon the experience of the therapist, and illustrated with examples.

  6. Swim stress reduces chronic pain in mice through an opioid mechanism.

    Science.gov (United States)

    Carmody, J; Cooper, K

    1987-03-09

    Chronic nociception has been studied in male mice by means of the formalin test in which forelimb motor behaviour is scored after subcutaneous formalin injection. The rating remained above 2.0 for 30 min after the injection (scale range 0-3). The magnitude of the nociception has been compared with that reported in other animal types. Mice are more sensitive than rats, cats and monkeys. The stress of a swim of 3 min has been found to reduce nociception by up to 25%. This analgesia is wholly opioid in nature, being abolished by a moderate dose of naloxone (1 mg/kg).

  7. Effect of chronic psychogenic stress on some behavioral and neurochemical characteristics of rats

    International Nuclear Information System (INIS)

    Danchev, N.D.; Rozhanets, V.V.; Val'dman, A.V.

    1986-01-01

    This paper studies the behavioral, somatic, and certain neurochemical parameters in rats under conditions of unavoidable chronic stress, according to Hecht et al. in a situation of possible avoidance, with the same total number of aversive stimuli. Specific binding of tritium-flunitrazepam and tritium-dihydroalprenolol was studied. The dissociatin constant and the maximal concentration of ligand-receptor complexes were determined in Scatchard plots by means of an HP-33E computer. The protein concentration in the samples was determined by Peterson's method

  8. Examination of the interaction of different lighting conditions and chronic mild stress in animal model.

    Science.gov (United States)

    Muller, A; Gal, N; Betlehem, J; Fuller, N; Acs, P; Kovacs, G L; Fusz, K; Jozsa, R; Olah, A

    2015-09-01

    We examined the effects of different shift work schedules and chronic mild stress (CMS) on mood using animal model. The most common international shift work schedules in nursing were applied by three groups of Wistar-rats and a control group with normal light-dark cycle. One subgroup from each group was subjected to CMS. Levels of anxiety and emotional life were evaluated in light-dark box. Differences between the groups according to independent and dependent variables were examined with one- and two-way analysis of variance, with a significance level defined at p animals.

  9. 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.

  10. Performance investigation on the ultrasonic atomization liquid desiccant regeneration system

    International Nuclear Information System (INIS)

    Yang, Zili; Zhang, Kaisheng; Hwang, Yunho; Lian, Zhiwei

    2016-01-01

    Highlights: • We applied ultrasonic atomization technology to boost liquid desiccant regeneration. • We established a novel UARS and made a thorough study on its performance. • We developed a performance prediction model for UARS and validated its accuracy. • The necessary regeneration temperature dropped significantly (4.4 °C) in UARS. • Energy consumption for regenerating desiccant was reduced greatly (60.4%) in UARS. - Abstract: Liquid desiccant dehumidification systems have accumulated considerable research interest in recent years for their great energy saving potential in buildings. Within the system, the regenerator recovering liquid desiccant plays a major role in its performance. When the ultrasonic atomization technology is applied to atomize the desiccant solution into numerous tiny droplets with diameters around 50 μm, the regeneration process could be greatly enhanced. To validate this approach, a novel ultrasonic atomization liquid desiccant regeneration system (UARS) was studied in this work. An Ideal Regeneration Model (IRM) was developed to predict the regeneration performance of the UARS. Additionally, thorough experiments were carried out to validate the model under different operating conditions of the desiccant solution and air stream. The model predicted values and the experimental results coincided, with the average deviation less than 7.9%. The performance of UARS was compared with other regeneration systems from the open literature, while a case study was conducted for the power consumption and energy saving potential of UARS. It was found that the ultrasonic atomization technology enabled utilization of lower-grade energy for desiccant regeneration with the regeneration temperature lowered as much as 4.4 °C. In addition, a considerable energy saving potential of up to 23.4% could be achieved by the UARS for regenerating per unit mass flow of desiccant solution, while the power consumption of the ultrasonic atomization system

  11. DISTURBANCES OF BIOLOGICAL RHYTHMS IN A RAT CHRONIC MILD STRESS MODEL OF DEPRESSION

    DEFF Research Database (Denmark)

    Christiansen, Sofie; Wiborg, Ove; Bouzinova, Elena

    validated animal model of depression, the chronic mild stress model (CMS). Depression-like and control rats were killed by decapitation within 24 h. Trunk blood, brain and liver tissue were collected. The quantitative amount of plasma corticosterone and melatonin were measured using an ELISA and RIA kit...... that depression-like animals showed an abnormal circadian rhythm in the liver and in subregions of the rat brains related to depression. However, the SCN was partly protected against stress. We found an increased level of corticosteron and melatonin, in the depression-like animals as well as a shifted circadian......Aim: The focus of this project is to identify biomarkers related to circadian disturbances in major depressive disorder. Background: A large body of clinical data from depressed individuals showed that sleep, temperature, hormones, physiological states and moodchanges are consistent...

  12. Increased limbic phosphorylated extracellular-regulated kinase 1 and 2 expression after chronic stress is reduced by cyclic 17 beta-estradiol administration

    NARCIS (Netherlands)

    Gerrits, M.; Westenbroek, C.; Koch, T.; Grootkarzijn, A.; Ter Horst, G. J.

    2006-01-01

    Chronic stress induced neuronal changes that may have consequences for subsequent stress responses. For example, chronic stress in rats rearranges dendritic branching patterns and disturbs the phosphorylation of extracellular-regulated kinase 1 and 2 (ERK) 1/2 throughout the limbic system.

  13. Curcumin reverses the effects of chronic stress on behavior, the HPA axis, BDNF expression and phosphorylation of CREB.

    Science.gov (United States)

    Xu, Ying; Ku, Baoshan; Tie, Lu; Yao, Haiyan; Jiang, Wengao; Ma, Xing; Li, Xuejun

    2006-11-29

    Curcuma longa is a major constituent of the traditional Chinese medicine Xiaoyao-san, which has been used to effectively manage stress and depression-related disorders in China. Curcumin is the active component of curcuma longa, and its antidepressant effects were described in our prior studies in mouse models of behavioral despair. We hypothesized that curcumin may also alleviate stress-induced depressive-like behaviors and hypothalamic-pituitary-adrenal (HPA) axis dysfunction. Thus in present study we assessed whether curcumin treatment (2.5, 5 and 10 mg/kg, p.o.) affects behavior in a chronic unpredictable stress model of depression in rats and examined what its molecular targets may be. We found that subjecting animals to the chronic stress protocol for 20days resulted in performance deficits in the shuttle-box task and several physiological effects, such as an abnormal adrenal gland weight to body weight (AG/B) ratio and increased thickness of the adrenal cortex as well as elevated serum corticosterone levels and reduced glucocorticoid receptor (GR) mRNA expression. These changes were reversed by chronic curcumin administration (5 or 10 mg/kg, p.o.). In addition, we also found that the chronic stress procedure induced a down-regulation of brain-derived neurotrophic factor (BDNF) protein levels and reduced the ratio of phosphorylated cAMP response element-binding protein (pCREB) to CREB levels (pCREB/CREB) in the hippocampus and frontal cortex of stressed rats. Furthermore, these stress-induced decreases in BDNF and pCREB/CREB were also blocked by chronic curcumin administration (5 or 10 mg/kg, p.o.). These results provide compelling evidence that the behavioral effects of curcumin in chronically stressed animals, and by extension humans, may be related to their modulating effects on the HPA axis and neurotrophin factor expressions.

  14. Obesity and chronic stress are able to desynchronize the temporal pattern of serum levels of leptin and triglycerides.

    Science.gov (United States)

    de Oliveira, Carla; Scarabelot, Vanessa Leal; de Souza, Andressa; de Oliveira, Cleverson Moraes; Medeiros, Liciane Fernandes; de Macedo, Isabel Cristina; Marques Filho, Paulo Ricardo; Cioato, Stefania Giotti; Caumo, Wolnei; Torres, Iraci L S

    2014-01-01

    Disruption of the circadian system can lead to metabolic dysfunction as a response to environmental alterations. This study assessed the effects of the association between obesity and chronic stress on the temporal pattern of serum levels of adipogenic markers and corticosterone in rats. We evaluated weekly weight, delta weight, Lee index, and weight fractions of adipose tissue (mesenteric, MAT; subcutaneous, SAT; and pericardial, PAT) to control for hypercaloric diet-induced obesity model efficacy. Wistar rats were divided into four groups: standard chow (C), hypercaloric diet (HD), stress plus standard chow (S), and stress plus hypercaloric diet (SHD), and analyzed at three time points: ZT0, ZT12, and ZT18. Stressed animals were subjected to chronic stress for 1h per day, 5 days per week, during 80 days. The chronic exposure to a hypercaloric diet was an effective model for the induction of obesity and metabolic syndrome, increasing delta weight, Lee index, weight fractions of adipose tissue, and triglycerides and leptin levels. We confirmed the presence of a temporal pattern in the release of triglycerides, corticosterone, leptin, and adiponectin in naïve animals. Chronic stress reduced delta weight, MAT weight, and levels of triglycerides, total cholesterol, and leptin. There were interactions between chronic stress and obesity and serum total cholesterol levels, between time points and obesity and adiponectin and corticosterone levels, and between time points and chronic stress and serum leptin levels. In conclusion, both parameters were able to desynchronize the temporal pattern of leptin and triglyceride release, which could contribute to the development of metabolic diseases such as obesity and metabolic syndrome. Copyright © 2013 Elsevier Inc. All rights reserved.

  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. Greenness and job-related chronic stress in young adults: a prospective cohort study in Germany.

    Science.gov (United States)

    Herrera, Ronald; Markevych, Iana; Berger, Ursula; Genuneit, Jon; Gerlich, Jessica; Nowak, Dennis; Schlotz, Wolff; Vogelberg, Christian; von Mutius, Erika; Weinmayr, Gudrun; Windstetter, Doris; Weigl, Matthias; Heinrich, Joachim; Radon, Katja

    2018-06-04

    We aimed to prospectively study the association between normalised difference vegetation index (NDVI) as a measure of greenness around homes and occupational stress. A population-based cohort in Munich and Dresden cities was followed from age 16-18 years to age 20-23 years (n=1632). At baseline, all participants attended high-school while at follow-up some had started working and others studying at university. At baseline and in each follow-up, we assigned NDVI based on participants' residential geocoded addresses and categorised it by quartiles. School-related, university-related or job-related self-reported chronic stress was assessed at the two follow-ups by the Trier Scale for Assessment of Chronic Stress using work discontent and work overload as outcomes. We modelled the association employing ordinal generalised estimating equations model accounting for changes in sociodemographics, non-job-related stress, job history and environmental covariates. Stratified analysis by each city was performed. NVDI at baseline was higher for participants from Dresden (median=0.36; IQR 0.31-0.41) than Munich (0.31; 0.26-0.34). At follow-up, it decreased only for participants in Dresden (0.34; 0.30-0.40). Higher greenness (quartile 4 vs quartile 1) was associated with less work discontent (OR 0.89; 95% CI 0.80 to 0.99) and less work overload (OR 0.87; 95% CI 0.78 to 0.96). In stratified analyses, results were more consistent for Munich than for Dresden. Our results suggest that residential green spaces, using the vegetation index as a proxy for exposure, are inversely associated with two types of job-related chronic stress in German young adults transitioning from school to university or working life. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  17. Neuropeptide Y stimulation as primary target for preventive measures of maladaptative cardiovascular reactions in occupational chronic stress exposure.

    Science.gov (United States)

    Ciumaşu-Rîmbu, Mălina; Popa, Livia; Vulpoi, Carmen

    2012-01-01

    Chronic stress may produce a decrease in central NPY expression and subjects exposed to it may prove hypersensitivity to a novel stressor with dysfunctions in the NPY system and cardiovascular maladaptation to stress, even hypertension. Upregulation of NPY expression may contribute to successful behavioral adaptation to stress by reducing cardiovascular tone and suppressing anxious behaviors. Adaptogens, a new class of metabolic regulators stimulate NPY expression and release. The aim of this study is to increase tolerance and adaptation to stress of hypersensitive to novel stressor, occupational chronic stress exposed subjects with cardiovascular maladaptation to mild new stressor using adaptogens as part of prevention protocol. 40 military personnel with known cardiostressor reactional mode and occupational chronic stress exposure were exposed to mild novel stressor: occupational medicine routine evaluation and clinically assessed for maladaptative cardiovascular response prior and before application of 30 day prevention protocol. Employees were randomly split in two groups, one receiving standard prevention protocol (lifestyle counseling) plus adaptogens in multiple dose administration, twice daily and the other receiving only standard prevention protocol. We found significant statistic differences in all cardiovascular parameters in adaptogen group and only in diastolic blood pressure in control group. Adaptogens could be an important factor in successful prevention protocols of chronic occupational stress dysfunctions involving NPY systems.

  18. 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.

  19. The effect of synchronized running activity with chronic stress on passive avoidance learning and body weight in rats

    Directory of Open Access Journals (Sweden)

    Maryam Radahmadi

    2013-01-01

    Results: Our results showed that: (1 Exercise under no stress provides beneficial effects on memory acquisition and retention time compared to Control group; especially retention time had significantly (P < 0.05 increased in exercised group. (2 Chronic stress with and without synchronized exercise significantly (P < 0.01, P < 0.05, respectively impaired acquisition and retention time. (3 Body weight differences were significantly (P < 0.01, P < 0.001 and P < 0.001 lower than Control group in exercise, stress and synchronized exercise with stress groups, respectively. (4 Adverse effects of restraint stress (psychical stress were probably greater than physical activity effects on learning, memory and weight loss. Conclusions: The data confirmed that synchronized exercise with stress had not significantly protective role in improvement of passive avoidance acquisition and retention time; hence it did not significantly improve learning and memory deficit in stressed rats; whereas exercise alone could improve memory deficit in rats.

  20. 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.

  1. The relation of illness perceptions to stress, depression, and fatigue in patients with chronic lymphocytic leukaemia.

    Science.gov (United States)

    Westbrook, Travis D; Maddocks, Kami; Andersen, Barbara L

    2016-07-01

    Chronic lymphocytic leukaemia (CLL) is the most prevalent adult leukaemia and is incurable. The course and treatment of CLL is unique and characterised by repeated cycles of treatment, stable disease and relapse. Utilising a Self-Regulatory Model framework, we examined the relationship between patients' illness perceptions and cancer-specific stress, depressive symptoms and fatigue. Our aim was to test illness perceptions as predictors of these outcomes when variance due to disease and treatment variables was controlled. Data were collected on 147 patients with relapsed/refractory CLL as they entered a phase II clinical trial of an investigational medication at a university affiliated, National Cancer Institute designated comprehensive cancer center. Cancer-specific stress, depressive symptoms and fatigue interference. . Hierarchical multiple regression was used. Consequences and emotional representation were related to all outcomes (ps stress (p fatigue interference (p stress, depressive symptoms and fatigue interference in relapsed/refractory CLL. Interventions targeted at restructuring maladaptive illness perceptions may have clinical benefit in this population.

  2. Protective effects of chronic mild stress during adolescence in the low-novelty responder rat.

    Science.gov (United States)

    Rana, Samir; Nam, Hyungwoo; Glover, Matthew E; Akil, Huda; Watson, Stanley J; Clinton, Sarah M; Kerman, Ilan A

    2016-01-01

    Stress-elicited behavioral and physiologic responses vary widely across individuals and depend on a combination of environmental and genetic factors. Adolescence is an important developmental period when neural circuits that guide emotional behavior and stress reactivity are still maturing. A critical question is whether stress exposure elicits contrasting effects when it occurs during adolescence versus adulthood. We previously found that Sprague-Dawley rats selectively bred for low-behavioral response to novelty (bred Low Responders; bLRs) are particularly sensitive to chronic unpredictable mild stress (CMS) exposure in adulthood, which exacerbates their typically high levels of spontaneous depressive- and anxiety-like behavior. Given developmental processes known to occur during adolescence, we sought to determine whether the impact of CMS on bLR rats is equivalent when they are exposed to it during adolescence as compared with adulthood. Young bLR rats were either exposed to CMS or control condition from postnatal days 35-60. As adults, we found that CMS-exposed bLRs maintained high levels of sucrose preference and exhibited increased social exploration along with decreased immobility on the forced swim test compared with bLR controls. These data indicate a protective effect of CMS exposure during adolescence in bLR rats.

  3. Chronic Stress and Limbic-Hypothalamopituitary-Adrenal Axis (LHPA Response in Female Reproductive system

    Directory of Open Access Journals (Sweden)

    Farideh Zafari Zangeneh

    2009-12-01

    Full Text Available The hypothalamo-pituitary-adrenocortical (HPA axis is a critical adaptive system that maximizes survival potential in the face of physical or psychological challenge. The principal end products of the HPA axis, glucocorticoid hormones, act on multiple organ systems, including the brain, to maintain homeostatic balance. The brain is a target of stress, and the hippocampus is the first brain region, besides the hypothalamus, to be recognized as a target of glucocorticoids. These anatomical areas in brain are limbic system, and in particular the hippocampus, medial prefrontal cortex (mPFC and amigdal that have multiple control points in regulation of the hypothalamic–pituitary–adrenal (HPA axis. The studies show the prefrontal cortex (PFC plays an important role in the regulation of stress-induced hypothalamic–pituitary–adrenal (HPA activity and regulation of gonadal function in men and women is under the control of the HPA. This regulation is complex and sex steroids are important regulators of GnRH and gonadotropin release through classic feedback mechanisms in the hypothalamus and pituitary gland. Chronic stress can have a deleterious effect on the reproductive axis that, for females, is manifested in reduced pulsatile gonadotropin secretion and increased incidence of ovulatory abnormalities and infertility. The limbic–hypothalamic–pituitary–adrenal (LHPA axis suggests a functional role for gonadal steroids in the regulation of a female’s response to stress.

  4. Comorbidity of Alcohol Use Disorder and Chronic Pain: Genetic Influences on Brain Reward and Stress Systems.

    Science.gov (United States)

    Yeung, Ellen W; Craggs, Jason G; Gizer, Ian R

    2017-11-01

    Alcohol use disorder (AUD) is highly comorbid with chronic pain (CP). Evidence has suggested that neuroadaptive processes characterized by reward deficit and stress surfeit are involved in the development of AUD and pain chronification. Neurological data suggest that shared genetic architecture associated with the reward and stress systems may contribute to the comorbidity of AUD and CP. This monograph first delineates the prevailing theories of the development of AUD and pain chronification focusing on the reward and stress systems. It then provides a brief summary of relevant neurological findings followed by an evaluation of evidence documented by molecular genetic studies. Candidate gene association studies have provided some initial support for the genetic overlap between AUD and CP; however, these results must be interpreted with caution until studies with sufficient statistical power are conducted and replications obtained. Genomewide association studies have suggested a number of genes (e.g., TBX19, HTR7, and ADRA1A) that are either directly or indirectly related to the reward and stress systems in the AUD and CP literature. Evidence reviewed in this monograph suggests that shared genetic liability underlying the comorbidity between AUD and CP, if present, is likely to be complex. As the advancement in molecular genetic methods continues, future studies may show broader central nervous system involvement in AUD-CP comorbidity. Copyright © 2017 by the Research Society on Alcoholism.

  5. 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.

  6. 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 amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs). Given the numerous changes observed in the hippocampus following stress, it is difficult to pinpoint the pertinent contributing pathophysiological factors. Here we directly assess the impact of a reduction in tonic GABAergic inhibition of dentate gyrus granule cells on learning and memory using a mouse model with a decrease in GABAA R δ subunit expression specifically in dentate gyrus granule cells (Gabrd/Pomc mice). Reduced GABAA R δ subunit expression and function in dentate gyrus granule cells is sufficient to induce deficits in learning and memory. Collectively, these findings suggest that the reduction in GABAA R δ subunit-mediated tonic inhibition

  7. Reduced tonic inhibition in the dentate gyrus contributes to chronic stress-induced impairments in learning and memory

    Science.gov (United States)

    Hooper, Andrew; Maguire, Jamie

    2016-01-01

    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 (GABAAR) 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 amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs). Given the numerous changes observed in the hippocampus following stress, it is difficult to pinpoint the pertinent contributing pathophysiological factors. Here we directly assess the impact of a reduction in tonic GABAergic inhibition of dentate gyrus granule cells on learning and memory using a mouse model with a decrease in GABAAR δ subunit expression specifically in dentate gyrus granule cells (Gabrd/Pomc mice). Reduced GABAAR δ subunit expression and function in dentate gyrus granule cells is sufficient to induce deficits in learning and memory. Collectively, these findings suggest that the reduction in GABAAR δ subunit-mediated tonic inhibition in

  8. Desiccation tolerance of Sphagnum revisited: a puzzle resolved.

    Science.gov (United States)

    Hájek, T; Vicherová, E

    2014-07-01

    As ecosystem engineers, Sphagnum mosses control their surroundings through water retention, acidification and peat accumulation. Because water retention avoids desiccation, sphagna are generally intolerant to drought; however, the literature on Sphagnum desiccation tolerance (DT) provides puzzling results, indicating the inducible nature of their DT. To test this, various Sphagnum species and other mesic bryophytes were hardened to drought by (i) slow drying; (ii) ABA application and (iii) chilling or frost. DT tolerance was assessed as recovery of chlorophyll fluorescence parameters after severe desiccation. We monitored the seasonal course of DT in bog bryophytes. Under laboratory conditions, following initial de-hardening, untreated Sphagnum shoots lacked DT; however, DT was induced by all hardening treatments except chilling, notably by slow drying, and in Sphagnum species of the section Cuspidata. In the field, sphagna in hollows and lawns developed DT several times during the growing season, responding to reduced precipitation and a lowered water table. Hummock and aquatic species developed DT only in late autumn, probably as a response to frost. Sphagnum protonemata failed to develop DT; hence, desiccation may limit Sphagnum establishment in drier habitats with suitable substrate chemistry. Desiccation avoiders among sphagna form compact hummocks or live submerged; thus, they do not develop DT in the field, lacking the initial desiccation experience, which is frequent in hollow and lawn habitats. We confirmed the morpho-physiological trade-off: in contrast to typical hollow sphagna, hummock species invest more resources in water retention (desiccation avoidance), while they have a lower ability to develop physiological DT. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  9. Biological stress systems, adverse life events and the improvement of chronic multi-site musculoskeletal pain across a 6-year follow-up

    NARCIS (Netherlands)

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

    Dysfunction of biological stress systems and adverse life events, independently and in interaction, have been hypothesized to predict chronic pain persistence. Conversely, these factors may hamper the improvement of chronic pain. Longitudinal evidence is currently lacking. We examined whether: 1)

  10. Biological Stress Systems, Adverse Life Events, and the Improvement of Chronic Multisite Musculoskeletal Pain Across a 6-Year Follow-Up

    NARCIS (Netherlands)

    Generaal, Ellen; Vogelzangs, Nicole; Macfarlane, Gary J; Geenen, Rinie; Smit, Johannes H; de Geus, Eco J C N; Dekker, Joost; Penninx, Brenda W J H

    Dysfunction of biological stress systems and adverse life events, independently and in interaction, have been hypothesized to predict chronic pain persistence. Conversely, these factors may hamper the improvement of chronic pain. Longitudinal evidence is currently lacking. We examined whether: 1)

  11. Voluntary exercise and increased food intake after mild chronic stress improve social avoidance behavior in mice.

    Science.gov (United States)

    Otsuka, Airi; Shiuchi, Tetsuya; Chikahisa, Sachiko; Shimizu, Noriyuki; Séi, Hiroyoshi

    2015-11-01

    It is well-established that exercise can influence psychological conditions, cognitive function, and energy metabolism in peripheral tissues including the skeletal muscle. However, it is not clear whether exercise can influence social interaction with others and alleviate defeat stress. This study investigated the effect of voluntary wheel running on impaired social interaction induced by chronic social defeat stress (SDS) using the resident-intruder social defeat model. Mice were divided into three groups: control, stress alone, and stress+exercise. SDS was performed by exposing C57BL/6 mice to retired ICR mice for 2.5 min. The C57BL/6 mice were continuously defeated by these resident (aggressor) mice and, following 5 days of SDS, experienced 2 days of rest with no SDS. Mice in the stress+exercise group were allowed to voluntarily run on a wheel for 2h after every SDS exposure. Two weeks later, compared to the control group, the stress group showed a higher ratio of time spent in the corner zone of a social interaction paradigm even though SDS did not elicit depressive- and anxiety-like behaviors. We also observed that voluntary exercise, which did not affect muscle weight and gene expression, decreased social avoidance behavior of stressed mice without clear changes in brain monoamine levels. Interestingly, food intake in the stress+exercise group was the greatest among the three groups. To test the effect of the exercise-induced increase in food intake on social behavior, we set up a pair-fed group where food intake was restricted. We then compared these mice to mice in the stress alone group. We found that the ratio of time spent in the corner zone of the social interaction test was not different between ad libitum- and pair-fed groups, although pair-fed mice spent more time in the corner zone when an aggressor mouse was present than when it was absent. In addition, pair-feeding did not show exercise-induced reductions of adrenal gland weight and enhanced the

  12. Chronic inflammatory diseases are stimulated by current lifestyle: how diet, stress levels and medication prevent our body from recovering

    Directory of Open Access Journals (Sweden)

    Bosma-den Boer Margarethe M

    2012-04-01

    Full Text Available Abstract Serhan and colleagues introduced the term "Resoleomics" in 1996 as the process of inflammation resolution. The major discovery of Serhan's work is that onset to conclusion of an inflammation is a controlled process of the immune system (IS and not simply the consequence of an extinguished or "exhausted" immune reaction. Resoleomics can be considered as the evolutionary mechanism of restoring homeostatic balances after injury, inflammation and infection. Under normal circumstances, Resoleomics should be able to conclude inflammatory responses. Considering the modern pandemic increase of chronic medical and psychiatric illnesses involving chronic inflammation, it has become apparent that Resoleomics is not fulfilling its potential resolving capacity. We suggest that recent drastic changes in lifestyle, including diet and psycho-emotional stress, are responsible for inflammation and for disturbances in Resoleomics. In addition, current interventions, like chronic use of anti-inflammatory medication, suppress Resoleomics. These new lifestyle factors, including the use of medication, should be considered health hazards, as they are capable of long-term or chronic activation of the central stress axes. The IS is designed to produce solutions for fast, intensive hazards, not to cope with long-term, chronic stimulation. The never-ending stress factors of recent lifestyle changes have pushed the IS and the central stress system into a constant state of activity, leading to chronically unresolved inflammation and increased vulnerability for chronic disease. Our hypothesis is that modern diet, increased psycho-emotional stress and chronic use of anti-inflammatory medication disrupt the natural process of inflammation resolution ie Resoleomics.

  13. Interaction of CD38 Variant and Chronic Interpersonal Stress Prospectively Predicts Social Anxiety and Depression Symptoms Over Six Years

    Science.gov (United States)

    Tabak, Benjamin A.; Vrshek-Schallhorn, Suzanne; Zinbarg, Richard E.; Prenoveau, Jason M.; Mineka, Susan; Redei, Eva E.; Adam, Emma K.; Craske, Michelle G.

    2015-01-01

    Variation in the CD38 gene, which regulates secretion of the neuropeptide oxytocin, has been associated with several social phenotypes. Specifically, rs3796863 A allele carriers have demonstrated increased social sensitivity. In 400 older adolescents, we used trait-state-occasion modeling to investigate how rs3796863 genotype, baseline ratings of chronic interpersonal stress, and their gene-environment (GxE) interaction predicted trait social anxiety and depression symptoms over six years. We found significant GxE effects for CD38 A-carrier genotypes and chronic interpersonal stress at baseline predicting greater social anxiety and depression symptoms. A significant GxE effect of smaller magnitude was also found for C/C genotype and chronic interpersonal stress predicting greater depression; however, this effect was small compared to the main effect of chronic interpersonal stress. Thus, in the context of chronic interpersonal stress, heightened social sensitivity associated with the rs3796863 A allele may prospectively predict risk for social anxiety and (to a lesser extent) depression. PMID:26958455

  14. Chronic early postnatal scream sound stress induces learning deficits and NMDA receptor changes in the hippocampus of adult mice.

    Science.gov (United States)

    Hu, Lili; Han, Bo; Zhao, Xiaoge; Mi, Lihua; Song, Qiang; Wang, Jue; Song, Tusheng; Huang, Chen

    2016-04-13

    Chronic scream sounds during adulthood affect spatial learning and memory, both of which are sexually dimorphic. The long-term effects of chronic early postnatal scream sound stress (SSS) during postnatal days 1-21 (P1-P21) on spatial learning and memory in adult mice as well as whether or not these effects are sexually dimorphic are unknown. Therefore, the present study examines the performance of adult male and female mice in the Morris water maze following exposure to chronic early postnatal SSS. Hippocampal NR2A and NR2B levels as well as NR2A/NR2B subunit ratios were tested using immunohistochemistry. In the Morris water maze, stress males showed greater impairment in spatial learning and memory than background males; by contrast, stress and background females performed equally well. NR2B levels in CA1 and CA3 were upregulated, whereas NR2A/NR2B ratios were downregulated in stressed males, but not in females. These data suggest that chronic early postnatal SSS influences spatial learning and memory ability, levels of hippocampal NR2B, and NR2A/NR2B ratios in adult males. Moreover, chronic early stress-induced alterations exert long-lasting effects and appear to affect performance in a sex-specific manner.

  15. Quercetin Attenuates Vascular Calcification through Suppressed Oxidative Stress in Adenine-Induced Chronic Renal Failure Rats

    Directory of Open Access Journals (Sweden)

    Xue-ying Chang

    2017-01-01

    Full Text Available Background. This study investigated whether quercetin could alleviate vascular calcification in experimental chronic renal failure rats induced by adenine. Methods. 32 adult male Wistar rats were randomly divided into 4 groups fed normal diet, normal diet with quercetin supplementation (25 mg/kg·BW/d, 0.75% adenine diet, or adenine diet with quercetin supplementation. All rats were sacrificed after 6 weeks of intervention. Serum renal functions biomarkers and oxidative stress biomarkers were measured and status of vascular calcification in aorta was assessed. Furthermore, the induced nitric oxide synthase (iNOS/p38 mitogen activated protein kinase (p38MAPK pathway was determined to explore the potential mechanism. Results. Adenine successfully induced renal failure and vascular calcification in rat model. Quercetin supplementation reversed unfavorable changes of phosphorous, uric acid (UA and creatinine levels, malonaldehyde (MDA content, and superoxide dismutase (SOD activity in serum and the increases of calcium and alkaline phosphatase (ALP activity in the aorta (P<0.05 and attenuated calcification and calcium accumulation in the medial layer of vasculature in histopathology. Western blot analysis showed that iNOS/p38MAPK pathway was normalized by the quercetin supplementation. Conclusions. Quercetin exerted a protective effect on vascular calcification in adenine-induced chronic renal failure rats, possibly through the modulation of oxidative stress and iNOs/p38MAPK pathway.

  16. Short-Term Caloric Restriction Suppresses Cardiac Oxidative Stress and Hypertrophy Caused by Chronic Pressure Overload.

    Science.gov (United States)

    Kobara, Miyuki; Furumori-Yukiya, Akiko; Kitamura, Miho; Matsumura, Mihoko; Ohigashi, Makoto; Toba, Hiroe; Nakata, Tetsuo

    2015-08-01

    Caloric restriction (CR) prevents senescent changes, in which reactive oxygen species (ROS) have a critical role. Left ventricular (LV) hypertrophy is a risk factor for cardiovascular diseases. We examined whether CR alters cardiac redox state and hypertrophy from chronic pressure overload. Male c57BL6 mice were subjected to ascending aortic constriction (AAC) with ad libitum caloric intake (AL + AAC group) or 40% restricted caloric intake (CR + AAC group). CR was initiated 2 weeks before AAC and was continued for 4 weeks. Two weeks after constriction, AAC increased LV wall thickness, impaired transmitral flow velocity, and augmented myocyte hypertrophy and fibrosis, in association with enhancement of BNP and collagen III expressions in the AL + AAC group. In the AL + AAC group, oxidative stress in cardiac tissue and mitochondria were enhanced, and NADPH oxidase activity and mitochondrial ROS production were elevated. These changes were significantly attenuated in the CR + AAC group. Additionally, in antioxidant systems, myocardial glutathione peroxidase and superoxide dismutase activities were enhanced in the CR + AAC group. Chronic pressure overload increased cardiac oxidative damage, in association with cardiac hypertrophy and fibrosis. Short-term CR suppressed oxidative stress and improved cardiac function, suggesting that short-term CR could be a useful strategy to prevent pressure overload-induced cardiac injury. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Quercetin Attenuates Vascular Calcification through Suppressed Oxidative Stress in Adenine-Induced Chronic Renal Failure Rats.

    Science.gov (United States)

    Chang, Xue-Ying; Cui, Lei; Wang, Xing-Zhi; Zhang, Lei; Zhu, Dan; Zhou, Xiao-Rong; Hao, Li-Rong

    2017-01-01

    This study investigated whether quercetin could alleviate vascular calcification in experimental chronic renal failure rats induced by adenine. 32 adult male Wistar rats were randomly divided into 4 groups fed normal diet, normal diet with quercetin supplementation (25 mg/kg·BW/d), 0.75% adenine diet, or adenine diet with quercetin supplementation. All rats were sacrificed after 6 weeks of intervention. Serum renal functions biomarkers and oxidative stress biomarkers were measured and status of vascular calcification in aorta was assessed. Furthermore, the induced nitric oxide synthase (iNOS)/p38 mitogen activated protein kinase (p38MAPK) pathway was determined to explore the potential mechanism. Adenine successfully induced renal failure and vascular calcification in rat model. Quercetin supplementation reversed unfavorable changes of phosphorous, uric acid (UA) and creatinine levels, malonaldehyde (MDA) content, and superoxide dismutase (SOD) activity in serum and the increases of calcium and alkaline phosphatase (ALP) activity in the aorta ( P chronic renal failure rats, possibly through the modulation of oxidative stress and iNOs/p38MAPK pathway.

  18. Quercetin Attenuates Vascular Calcification through Suppressed Oxidative Stress in Adenine-Induced Chronic Renal Failure Rats

    Science.gov (United States)

    Chang, Xue-ying; Cui, Lei; Wang, Xing-zhi; Zhang, Lei; Zhu, Dan

    2017-01-01

    Background This study investigated whether quercetin could alleviate vascular calcification in experimental chronic renal failure rats induced by adenine. Methods 32 adult male Wistar rats were randomly divided into 4 groups fed normal diet, normal diet with quercetin supplementation (25 mg/kg·BW/d), 0.75% adenine diet, or adenine diet with quercetin supplementation. All rats were sacrificed after 6 weeks of intervention. Serum renal functions biomarkers and oxidative stress biomarkers were measured and status of vascular calcification in aorta was assessed. Furthermore, the induced nitric oxide synthase (iNOS)/p38 mitogen activated protein kinase (p38MAPK) pathway was determined to explore the potential mechanism. Results Adenine successfully induced renal failure and vascular calcification in rat model. Quercetin supplementation reversed unfavorable changes of phosphorous, uric acid (UA) and creatinine levels, malonaldehyde (MDA) content, and superoxide dismutase (SOD) activity in serum and the increases of calcium and alkaline phosphatase (ALP) activity in the aorta (P chronic renal failure rats, possibly through the modulation of oxidative stress and iNOs/p38MAPK pathway. PMID:28691026

  19. Desipramine rescues age-related phenotypes in depression-like rats induced by chronic mild stress.

    Science.gov (United States)

    Xie, Xiaoxian; Chen, Yangyang; Wang, Qi; Shen, Qichen; Ma, Lingyan; Huang, Liangfeng; Wu, Tao; Fu, Zhengwei

    2017-11-01

    Our previous finding demonstrates that major depressive disorder can mediate accelerated aging in rats. Desipramine is a typical tricyclic antidepressant, and can provide neuroprotection and counteract depression-like behaviors. However, whether desipramine can rescue age-related phenotypes in depressed individuals is not understood. In the present study, we investigated the physiological function of desipramine on rescuing the age-related phenotypes in these animals. The rats were induced by chronic mild stress paradigm, and the depression-like behaviors of rats were detected by sucrose intake test, open field test (OFT) and forced swimming test (FST). Then the depressed rats were treated by desipramine. Desipramine administration was effective in counteracting depression-like behaviors by increasing the sucrose solution intake, reducing the immobility time in the FST, and increasing total distance travelled and numbers of grid line crossed in the OFT. Moreover, desipramine treatment was able to reduce the oxidative damage to rat liver, and to increase the expression of telomerase reverse transcriptase (TERT), leading to correspondingly restored telomerase activity. Our findings identify that one function of desipramine may partly be to rescue age-related phenotypes in depressed individuals induced by chronic stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Hyperoside protects against chronic mild stress-induced learning and memory deficits.

    Science.gov (United States)

    Gong, Yeli; Yang, Youhua; Chen, Xiaoqing; Yang, Min; Huang, Dan; Yang, Rong; Zhou, Lianying; Li, Changlei; Xiong, Qiuju; Xiong, Zhe

    2017-07-01

    Hyperoside (quercetin-3-O-b-d-galactosidepyranose) is a plant-derived flavonoid mainly found in fruits, fruit juices (most notably flavanols, flavanones, and anthocyanins) and Chinese traditional medicines. It has been applied to relieve pain and improve cardiovascular functions in clinic. However, the effects of hyperoside on cognitive impairment induced by chronic stress and the underlying molecular mechanisms remain unclear. In the current study, we used chronic mild stress (CMS) rats to investigate the effects of hyperoside on learning and memory and further explore the possible mechanisms. Our results demonstrated that hyperoside reduced the escape latency and the swimming distance of CMS rats in Morris water maze test and reversed depressive symptoms in forced swim test (FST) and sucrose preference test. In addition, hyperoside increased the expression of brain-derived neurotrophic factor (BDNF) in hippocampus of CMS rats without influencing the corticosterone (CORT) level in blood plasma. Furthermore, K252a, an inhibitor of the BDNF receptor TrkB, prevented the protective effects of hyperoside on learning and memory in CMS rats. Taken together, these results indicate that hyperoside reverses the cognitive impairment induced by CMS, which is associated with the regulation of BDNF signaling pathway. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  1. How specialized volatiles respond to chronic and short-term physiological and shock heat stress in Brassica nigra.

    Science.gov (United States)

    Kask, Kaia; Kännaste, Astrid; Talts, Eero; Copolovici, Lucian; Niinemets, Ülo

    2016-09-01

    Brassicales release volatile glucosinolate breakdown products upon tissue mechanical damage, but it is unclear how the release of glucosinolate volatiles responds to abiotic stresses such as heat stress. We used three different heat treatments, simulating different dynamic temperature conditions in the field to gain insight into stress-dependent changes in volatile blends and photosynthetic characteristics in the annual herb Brassica nigra (L.) Koch. Heat stress was applied by either heating leaves through temperature response curve measurements from 20 to 40 °C (mild stress), exposing plants for 4 h to temperatures 25-44 °C (long-term stress) or shock-heating leaves to 45-50 °C. Photosynthetic reduction through temperature response curves was associated with decreased stomatal conductance, while the reduction due to long-term stress and collapse of photosynthetic activity after heat shock stress were associated with non-stomatal processes. Mild stress decreased constitutive monoterpene emissions, while long-term stress and shock stress resulted in emissions of the lipoxygenase pathway and glucosinolate volatiles. Glucosinolate volatile release was more strongly elicited by long-term stress and lipoxygenase product released by heat shock. These results demonstrate that glucosinolate volatiles constitute a major part of emission blend in heat-stressed B. nigra plants, especially upon chronic stress that leads to induction responses. © 2016 John Wiley & Sons Ltd.

  2. Flexibility-Rigidity Coordination of the Dense Exopolysaccharide Matrix in Terrestrial Cyanobacteria Acclimated to Periodic Desiccation.

    Science.gov (United States)

    Liu, Wen; Cui, Lijuan; Xu, Haiyan; Zhu, Zhaoxia; Gao, Xiang

    2017-11-15

    A dense exopolysaccharide (EPS) matrix is crucial for cyanobacterial survival in terrestrial xeric environments, in which cyanobacteria undergo frequent expansion and shrinkage processes during environmental desiccation-rehydration cycles. However, it is unclear how terrestrial cyanobacteria coordinate the structural dynamics of the EPS matrix upon expansion and shrinkage to avoid potential mechanical stress while benefiting from the matrix. In the present study, we sought to answer this question by investigating the gene expression, protein dynamics, enzymatic characteristics, and biological roles of WspA, an abundantly secreted protein, in the representative terrestrial cyanobacterium Nostoc flagelliforme The results demonstrated that WspA is a novel β-galactosidase that facilitates softening of the EPS matrix by breaking the polysaccharide backbone under substantial moisture or facilitates the thickening and relinkage of the broken matrix during the drying process, and thus these regulations are well correlated with moisture availability or desiccation-rehydration cycles. This coordination of flexibility and rigidity of the cyanobacterial extracellular matrix may contribute to a favorable balance of cell growth and stress resistance in xeric environments. IMPORTANCE How the exopolysaccharide matrix is dynamically coordinated by exoproteins to cope with frequent expansion and shrinkage processes in terrestrial colonial cyanobacteria remains unclear. Here we elucidated the biochemical identity and biological roles of a dominant exoprotein in these regulation processes. Our study thus gained insight into this regulative mechanism in cyanobacteria to combat periodic desiccation. In addition, the filamentous drought-adapted cyanobacterium Nostoc flagelliforme serves as an ideal model for us to explore this issue in this study. Copyright © 2017 American Society for Microbiology.

  3. The Influence of Work-Related Chronic Stress on the Regulation of Emotion and on Functional Connectivity in the Brain

    Science.gov (United States)

    Golkar, Armita; Johansson, Emilia; Kasahara, Maki; Osika, Walter; Perski, Aleksander; Savic, Ivanka

    2014-01-01

    Despite mounting reports about the negative effects of chronic occupational stress on cognitive and emotional functions, the underlying mechanisms are unknown. Recent findings from structural MRI raise the question whether this condition could be associated with a functional uncoupling of the limbic networks and an impaired modulation of emotional stress. To address this, 40 subjects suffering from burnout symptoms attributed to chronic occupational stress and 70 controls were investigated using resting state functional MRI. The participants' ability to up- regulate, down-regulate, and maintain emotion was evaluated by recording their acoustic startle response while viewing neutral and negatively loaded images. Functional connectivity was calculated from amygdala seed regions, using explorative linear correlation analysis. Stressed subjects were less capable of down-regulating negative emotion, but had normal acoustic startle responses when asked to up-regulate or maintain emotion and when no regulation was required. The functional connectivity between the amygdala and the anterior cingulate cortex correlated with the ability to down-regulate negative emotion. This connectivity was significantly weaker in the burnout group, as was the amygdala connectivity with the dorsolateral prefrontal cortex and the motor cortex, whereas connectivity from the amygdala to the cerebellum and the insular cortex were stronger. In subjects suffering from chronic occupational stress, the functional couplings within the emotion- and stress-processing limbic networks seem to be altered, and associated with a reduced ability to down-regulate the response to emotional stress, providing a biological substrate for a further facilitation of the stress condition. PMID:25184294

  4. Antidepressant-Like Effects of Cordycepin in a Mice Model of Chronic Unpredictable Mild Stress

    Directory of Open Access Journals (Sweden)

    Zhang Tianzhu

    2014-01-01

    Full Text Available Cordycepin (3′-deoxyadenosine, a major bioactive component isolated from Cordyceps militaris, has multiple pharmacological activities. This study is attempted to investigate whether cordycepin (COR possesses beneficial effects on chronic unpredictable mild stress- (CUMS- induced behavioral deficits (depression-like behaviors and explore the possible mechanisms. ICR mice were subjected to chronic unpredictable mild stress for 42 consecutive days. Then, COR and fluoxetine (FLU, positive control drug were administered for 21 consecutive days at the last three weeks of CUMS procedure. The classical behavioral tests, open field test (OFT, sucrose preference test (SPT, tail suspension test (TST, and forced swimming test (FST, were applied to evaluate the antidepressant effects of COR. Then the serotonin (5-HT and noradrenaline (NE concentrations in hippocampal were evaluated by HPLC; tumor necrosis factor-α (TNF-α and interleukin-6 (IL-6 in hippocampal were evaluated, and the proteins of TNF-α, IL-6, NF-κBP65 5-HT receptor (5-HTR, and brain-derived neurotrophic factor (BDNF in hippocampal were evaluated by Western blot. Our results indicated that 6 weeks of CUMS exposure induced significant depression-like behavior, with low 5-HT and NE levels, high TNF-α and IL-6 in brain and high hippocampal TNF-α, IL-6, P-NF-κBP65, and 5-HTR levels, and low BDNF expression levels. Whereas, chronic COR (20, 40 mg/kg treatments reversed the behavioral deficiency induced by CUMS exposure, treatment with COR normalized the change of TNF-α, IL-6, 5-HT, and NE levels, which demonstrated that COR could partially restore CUMS-induced 5-HT receptor impairments and inflammation. Besides, hippocampal BDNF expressions were also upregulated after COR treatments. In conclusion, COR remarkably improved depression-like behavior in CUMS mice and its antidepressant activity is mediated, at least in part, by the upregulating BDNF and downregulating 5-HTR levels and

  5. Environmental enrichment reduces chronic psychosocial stress-induced anxiety and ethanol-related behaviors in mice.

    Science.gov (United States)

    Bahi, Amine

    2017-07-03

    Previous research from our laboratory has shown that exposure to chronic psychosocial stress increased voluntary ethanol consumption and preference as well as acquisition of ethanol-induced conditioned place preference (CPP) in mice. This study was done to determine whether an enriched environment could have "curative" effects on chronic psychosocial stress-induced ethanol intake and CPP. For this purpose, experimental mice "intruders" were exposed to the chronic subordinate colony (CSC) housing for 19 consecutive days in the presence of an aggressive "resident" mouse. At the end of that period, mice were tested for their anxiety-like behavior using the elevated plus maze (EPM) test then housed in a standard or enriched environment (SE or EE respectively). Anxiety and ethanol-related behaviors were investigated using the open field (OF) test, a standard two-bottle choice drinking paradigm, and the CPP procedure. As expected, CSC exposure increased anxiety-like behavior and reduced weight gain as compared to single housed colony (SHC) controls. In addition, CSC exposure increased voluntary ethanol intake and ethanol-CPP. Interestingly, we found that EE significantly and consistently reduced anxiety and ethanol consumption and preference. However, neither tastants' (saccharin and quinine) intake nor blood ethanol metabolism were affected by EE. Finally, and most importantly, EE reduced the acquisition of CPP induced by 1.5g/kg ethanol. Taken together, these results support the hypothesis that EE can reduce voluntary ethanol intake and ethanol-induced conditioned reward and seems to be one of the strategies to reduce the behavioral deficits and the risk of anxiety-induced alcohol abuse. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Active Desiccant-Based Preconditioning Market Analysis and Product Development

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, J.

    2001-01-11

    The Phase 1 report (ORNL/Sub/94-SVO44/1), completed earlier in this program, involved a comprehensive field survey and market analysis comparing various specialized outdoor air handling units. This initial investigation included conventional cooling and reheat, conventional cooling with sensible recovery, total energy recovery systems (passive desiccant technology) and various active desiccant systems. The report concluded that several markets do promise a significant sales opportunity for a Climate Changer-based active desiccant system offering. (Climate Changer is a registered trademark of Trane Company.) This initial market analysis defined the wants and needs of the end customers (design engineers and building owners), which, along with subsequent information included in this report, hav