999 resultados para moisture stress


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A Escala Bianchi de Stress foi construída e validada para avaliar o nível de stress do enfermeiro hospitalar no desempenho básico de suas atividades. É auto-aplicável, composta por 51 itens, divididos em seis domínios, que recebem uma pontuação com variação de 1 a 7. Os domínios são compostos por atividades envolvendo a assistência e o gerenciamento do cuidado. Com a sua utilização, pode-se verificar o domínio mais estressante para o grupo de enfermeiros ou para cada indivíduo e também avaliar as atividades mais estressantes naquela instituição. É um instrumento que auxilia na tomada de decisão para a implantação de estratégias de enfrentamento do stress do enfermeiro hospitalar.

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Background: Cells have the ability to respond and adapt to environmental changes through activation of stress-activated protein kinases (SAPKs). Although p38 SAPK signalling is known to participate in the regulation of gene expression little is known on the molecular mechanisms used by this SAPK to regulate stress-responsive genes and the overall set of genes regulated by p38 in response to different stimuli.Results: Here, we report a whole genome expression analyses on mouse embryonic fibroblasts (MEFs) treated with three different p38 SAPK activating-stimuli, namely osmostress, the cytokine TNFα and the protein synthesis inhibitor anisomycin. We have found that the activation kinetics of p38α SAPK in response to these insults is different and also leads to a complex gene pattern response specific for a given stress with a restricted set of overlapping genes. In addition, we have analysed the contribution of p38α the major p38 family member present in MEFs, to the overall stress-induced transcriptional response by using both a chemical inhibitor (SB203580) and p38α deficient (p38α-/-) MEFs. We show here that p38 SAPK dependency ranged between 60% and 88% depending on the treatments and that there is a very good overlap between the inhibitor treatment and the ko cells. Furthermore, we have found that the dependency of SAPK varies depending on the time the cells are subjected to osmostress. Conclusions: Our genome-wide transcriptional analyses shows a selective response to specific stimuli and a restricted common response of up to 20% of the stress up-regulated early genes that involves an important set of transcription factors, which might be critical for either cell adaptation or preparation for continuous extra-cellular changes. Interestingly, up to 85% of the up-regulated genes are under the transcriptional control of p38 SAPK. Thus, activation of p38 SAPK is critical to elicit the early gene expression program required for cell adaptation to stress.

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Either calorie restriction, loss of function of the nutrient-dependent PKA or TOR/SCH9 pathways, or activation of stress defences improves longevity in different eukaryotes. However, the molecular links between glucose depletion, nutrient-dependent pathways and stress responses are unknown. Here we show that either calorie restriction or inactivation of nutrient-dependent pathways induces life-span extension in fission yeast, and that such effect is dependent on the activation of the stress-dependent Sty1 MAP kinase. During transition to stationary phase in glucose-limiting conditions, Sty1 becomes activated and triggers a transcriptional stress program, whereas such activation does not occur under glucose-rich conditions. Deletion of the genes coding for the SCH9-homologue Sck2 or the Pka1 kinases, or mutations leading to constitutive activation of the Sty1 stress pathway increase life span under glucose-rich conditions, and importantly such beneficial effects depend ultimately on Sty1. Furthermore, cells lacking Pka1 display enhanced oxygen consumption and Sty1 activation under glucose-rich conditions. We conclude that calorie restriction favours oxidative metabolism, reactive oxygen species production and Sty1 MAP kinase activation, and this stress pathway favours life-span extension.

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Os objetivos deste estudo foram: identificar as representações acerca dos fatores desencadeadores do estresse, atribuídos pelos profissionais de enfermagem, na atividade laboral; e discutir a influência destes na sua atividade laboral. Optou-se por um estudo descritivo com abordagem qualitativa, para o qual foram utilizadas as premissas das Representações Sociais, tendo os estudos realizados como referencial de análise. Para coleta utilizou-se como instrumento entrevista semiestruturada e individual. A análise foi através da técnica de análise de conteúdo, a fim de buscar elementos para a compreensão das imagens como representações dos profissionais de enfermagem, o significado dos fatores estressantes, e sua influência na atividade laboral. A população estudada vive e convive com a falta de condições de trabalho, escassez de recursos materiais e humanos, e ainda com pessoal não treinado; o trabalhador sente-se insatisfeito, com fadiga mental e física - situações que podem propiciar o aparecimento do estresse no desempenho das atividades laborais.

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Abstract Sexual selection theory posits that ornaments can signal the genetic quality of an individual. Eumelanin-based coloration is such an ornament and can signal the ability to cope with a physiological stress response because the melanocortin system regulates eumelanogenesis as well as physiological stress responses. In the present article, we experimentally investigated whether the stronger stress sensitivity of light than dark eumelanic individuals stems from differential regulation of stress hormones. Our study shows that darker eumelanic barn owl nestlings have a lower corticosterone release after a stressful event, an association, which was also inherited from the mother (but not the father) to the offspring. Additionally, nestlings sired by darker eumelanic mothers more quickly reduced experimentally elevated corticosterone levels. This provides a solution as to how ornamented individuals can be more resistant to various sources of stress than drab conspecifics. Our study suggests that eumelanin-based coloration can be a sexually selected signal of resistance to stressful events.

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(from the journal abstract) Objectives: The birth of a high risk infant--such as a very or extremely premature infant--can represent an important traumatic experience for parents. R. DeMier, M. Hynan et al's "Perinatal PTSD Questionnaire" aims at exploring, retrospectively, parent's posttraumatic stress reactions following the birth of a high risk infant. This paper describes the French validation of this questionnaire. Methods: Fifty-two families with a very or extremely premature infant and 25 families with a full term infant responded to the "Perinatal PTSD Questionnaire" and the "Impact of Event Scale" when children were 18 months old. Results: Parents of high risk infants can present posttraumatic stress reactions such as intrusion, avoidance or arousal symptoms. The French version of the "Perinatal PTSD Questionnaire" has satisfactory psychometric properties. Conclusions: As posttraumatic reactions are not directly related to objective descriptions of the stressful event, it may be essential to the liaison child psychiatrist to consider individual posttraumatic reactions in order to optimise preventive intervention with the parents. A questionnaire should not replace a clinical interview, however it may represent a useful screening tool. Also, this questionnaire should be useful for research purposes. (PsycINFO Database Record (c) 2005 APA, all rights reserved)

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Cell-to-cell communication mediated by gap junctions made of Connexin36 (Cx36) contributes to pancreatic β-cell function. We have recently demonstrated that Cx36 also supports β-cell survival by a still unclear mechanism. Using specific Cx36 siRNAs or adenoviral vectors, we now show that Cx36 downregulation promotes apoptosis in INS-1E cells exposed to the pro-inflammatory cytokines (IL-1β, TNF-α and IFN-γ) involved at the onset of type 1 diabetes, whereas Cx36 overexpression protects against this effect. Cx36 overexpression also protects INS-1E cells against endoplasmic reticulum (ER) stress-mediated apoptosis, and alleviates the cytokine-induced production of reactive oxygen species, the depletion of the ER Ca(2+) stores, the CHOP overexpression and the degradation of the anti-apoptotic protein Bcl-2 and Mcl-1. We further show that cytokines activate the AMP-dependent protein kinase (AMPK) in a NO-dependent and ER-stress-dependent manner and that AMPK inhibits Cx36 expression. Altogether, the data suggest that Cx36 is involved in Ca(2+) homeostasis within the ER and that Cx36 expression is downregulated following ER stress and subsequent AMPK activation. As a result, cytokine-induced Cx36 downregulation elicits a positive feedback loop that amplifies ER stress and AMPK activation, leading to further Cx36 downregulation. The data reveal that Cx36 plays a central role in the oxidative stress and ER stress induced by cytokines and the subsequent regulation of AMPK activity, which in turn controls Cx36 expression and mitochondria-dependent apoptosis of insulin-producing cells.

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 During a search for genes controlling conidial dormancy in Aspergillus fumigatus, two dehydrin-like genes, DprA and DprB, were identified. The deduced proteins had repeated stretches of 23 amino acids that contained a conserved dehydrin-like protein (DPR) motif. Disrupted DprAΔ mutants were hypersensitive to oxidative stress and to phagocytic killing, whereas DprBΔ mutants were impaired in osmotic and pH stress responses. However, no effect was observed on their pathogenicity in our experimental models of invasive aspergillosis. Molecular dissection of the signaling pathways acting upstream showed that expression of DprA was dependent on the stress-activated kinase SakA and the cyclic AMP-protein kinase A (cAMP-PKA) pathways, which activate the bZIP transcription factor AtfA, while expression of DprB was dependent on the SakA mitogen-activated protein kinase (MAPK) pathway, and the zinc finger transcription factor PacC. Fluorescent protein fusions showed that both proteins were associated with peroxisomes and the cytosol. Accordingly, DprA and DprB were important for peroxisome function. Our findings reveal a novel family of stress-protective proteins in A. fumigatus and, potentially, in filamentous ascomycetes.

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Many inflammatory and infectious diseases are characterized by the activation of signaling pathways steaming from the endoplasmic reticulum (ER). These pathways, primarily associated with loss of ER homeostasis, are emerging as key regulators of inflammation and infection. Recent advances shed light on the mechanisms linking ER-stress and immune responses.

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Contexte: Impression clinique que l'Etat de Stress Post-traumatique (ESPT) est sous-diagnostiqué dans la prise en charge des patients qui sont évalués dans le cadre d'une urgence psychiatrique. Objectifs: (i) identifier la prévalence de l'ESPT dans une unité d'urgence psychiatrique au moyen d'un instrument diagnostic et la comparer avec le diagnostic clinique retenu dans un échantillon historique (ii) évaluer la perception des cliniciens quant à l'utilisation systématique d'un instrument diagnostic Méthodes: la prévalence de l'ESPT a été évaluée chez des patients consécutifs (N = 403) qui ont bénéficié d'une consultation par des psychiatres de l'Unité urgence-crise du Service de Psychiatrie de Liaison (PLI) du CHUV, en utilisant le module J du Mini Mental Neuropsychologic Interview (MINI 5.0.0, version CIM-10). Ce résultat a été comparé avec la prévalence de l'ESPT mentionné comme diagnostic dans les dossiers (N = 350) d'un échantillon historique. La perception des médecins-assistants de psychiatrie quant au dépistage systématique de l'ESPT avec un instrument a été étudiée en se basant sur la conduite d'un focus group d'assistants travaillant dans l'Unité urgence-crise du PLI. Résultats: Parmi les patients (N = 316) évalués à l'aide de l'instrument diagnostic, 20,3% (n = 64) réunissaient les critères de l'ESPT. Cela constitue un taux de prévalence significativement plus élevé que la prévalence d'ESPT documentée dans les dossiers de l'échantillon historique (0,57%). Par ailleurs, la prévalence de l'ESPT est significativement plus élevée parmi les groupes socio- économiques précarisés, tels que réfugiés et sans papiers (50%), patients venant d'un pays à histoire de guerre récente (47,1%), patients avec quatre (44,4%) ou trois comorbidités psychiatriques (35,3%), migrants (29,8%) et patients sans revenus professionnels (25%). Le focus groupe composé de 8 médecins-assistants a révélé que l'utilisation systématique d'un outil- diagnostic ne convenait pas dans le setting d'urgence psychiatrique, notamment parce que l'instrument a été considéré comme non adapté à une première consultation ou jugé avoir un impact négatif sur l'entretien clinique. Toutefois, après la fin de l'étude, les médecins-assistants estimaient qu'il était important de rechercher activement l'ESPT et continuaient à intégrer les éléments principaux du questionnaire dans leur travail clinique. Conclusion et perspectives: cette étude confirme que l'ESPT est largement sous-diagnostiqué dans le contexte des urgences psychiatriques, mais que l'usage systématique d'un outil diagnostic dans ce cadre ne satisfait pas les praticiens concernés. Pour améliorer la situation et au vu du fait qu'un instrument diagnostic est considéré comme non-adapté dans ce setting, il serait peut-être bénéfique d'envisager un dépistage ciblé et/ou de mettre en place une stratégie de formation institutionnelle.

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Rapport de synthèse : La consommation de boissons sucrées contenant du fructose a remarquablement augmenté ces dernières décennies et, on pense qu'elle joue un rôle important dans l'épidémie actuelle d'obésité et de troubles métaboliques. Des études faites sur des rats ont montré qu'une alimentation riche en sucre ou fructose induisait une obésité, une résistance à l'insuline, diabète, dyslipidémie et une hypertension artérielle, tandis que chez l'homme, une alimentation riche en fructose conduit, après quelques jours, au développement d'une hypertryglycémie et une résistance hépatique à l'insuline. Nous avons entrepris une étude de 7 jours d'alimentation riche en fructose ou d'une alimentation contrôlée chez six hommes en bonne santé. Les NEFA plasmatiques et la beta-hydroxybutyrate, l'oxydation nette de lipide (calorimétrie indirecte) et l'oxydation exogène de lipide (13 CO2) ont été surveillés dans des conditions basales, et après un chargement en lipide (huile d'olive marqué au 13C-trioléine), puis durant un stress mental standardisé. La clearance de lactate et les effets métaboliques de la perfusion de lactate exogène ont également été évalués. Nos résultats ont montré que l'alimentation riche en fructose diminue la concentration plasmatique de NEFA, de beta-hydroxybutyrate de même que l'oxydation des lipides dans les conditions de bases et après surcharge en lipides. De plus, l'alimentation riche en fructose amortie l'augmentation des NEFA plasmatique et l'oxydation des lipides exogènes durant le stress mental. Elle augmente également la concentration basale de lactate et la production de lactate de respectivement 31.8% et 53.8%, tandis que la clearance du lactate reste inchangée. L'injection de lactate diminue le taux des NEFA lors de l'alimentation de contrôle et l'alimentation de base, et l'oxydation nette de lipide lors de l'alimentation de contrôle et l'alimentation riche en fructose. Ces résultats indiquent que 7 jours d'alimentation riche en fructose inhibent remarquablement la lipolyse et l'oxydation des lipides. L'alimentation riche en fructose augmente aussi la production de lactate, et l'augmentation de l'utilisation de lactate peut contribuer à supprimer l'oxydation des lipides. Abstact : The effects of a 7 d high-fructose diet (HFrD) or control diet on lipid metabolism were studied in a group of six healthy lean males. Plasma NEFA and β-hydroxybutyrate concentrations, net lipid oxidation (indirect calorimetry) and exogenous lipid oxidation (13CO2 production) were monitored in basal conditions, after lipid loading (olive oil labelled with [13C] triolein) and during a standardised mental stress. Lactate clearance and the metabolic effects of an exogenous lactate infusion were also monitored. The HFrD lowered plasma concentrations of NEFA and (β-hydroxybutyrate as well as lipid oxidation in both basal and after lipid-loading conditions. In addition, the HFrD blunted the increase in plasma NEFA and exogenous lipid oxidation during mental stress. The HFrD also increased basal lactate concentrations by 31.8%, and lactate production by 53.8 %, while lactate clearance remained unchanged. Lactate infusion lowered plasma NEFA with the control diet, and net lipid oxidation with both the HFrD and control diet. These results indicate that a 7 d HFrD markedly inhibits lipolysis and lipid oxidation. The HFrD also increases lactate production, and the ensuing increased lactate utilisation may contribute to suppress lipid oxidation.

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Moisture sensitivity of Hot Mix Asphalt (HMA) mixtures, generally called stripping, is a major form of distress in asphalt concrete pavement. It is characterized by the loss of adhesive bond between the asphalt binder and the aggregate (a failure of the bonding of the binder to the aggregate) or by a softening of the cohesive bonds within the asphalt binder (a failure within the binder itself), both of which are due to the action of loading under traffic in the presence of moisture. The evaluation of HMA moisture sensitivity has been divided into two categories: visual inspection test and mechanical test. However, most of them have been developed in pre-Superpave mix design. This research was undertaken to develop a protocol for evaluating the moisture sensitivity potential of HMA mixtures using the Nottingham Asphalt Tester (NAT). The mechanisms of HMA moisture sensitivity were reviewed and the test protocols using the NAT were developed. Different types of blends as moisture-sensitive groups and non-moisture-sensitive groups were used to evaluate the potential of the proposed test. The test results were analyzed with three parameters based on performance character: the retained flow number depending on critical permanent deformation failure (RFNP), the retained flow number depending on cohesion failure (RFNC), and energy ratio (ER). Analysis based on energy ratio of elastic strain (EREE ) at flow number of cohesion failure (FNC) has higher potential to evaluate the HMA moisture sensitivity than other parameters. If the measurement error in data-acquisition process is removed, analyses based on RFNP and RFNC would also have high potential to evaluate the HMA moisture sensitivity. The vacuum pressure saturation used in AASHTO T 283 and proposed test has a risk to damage specimen before the load applying.

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Genetic background, prenatal and post-natal early-life conditions influence the development of interconnected physiological systems and thereby shape the phenotype. Certain combinations of genotypes and pre- and post-natal conditions may provide higher fitness in a specific environmental context. Here, we investigated how grey partridges Perdix perdix of two strains (wild and domesticated) cope physiologically with pre- and post-natal predictable vs. unpredictable food supply. Food unpredictability occurs frequently in wild environments and requires physiological and behavioural adjustments. Well-orchestrated and efficient physiological systems are presumably more vital in a wild environment as compared to captivity. We thus predicted that wild-strain grey partridges have a stronger immunity, glucocorticoid (GC) stress response and oxidative stress resistance (OSR) than domesticated birds, which have undergone adaptations to captivity. We also predicted that wild-strain birds react more strongly to environmental stimuli and, when faced with harsh prenatal conditions, are better able to prepare their offspring for similarly poor post-natal conditions than birds of domesticated origin. We found that wild-strain offspring were physiologically better prepared for stressful situations as compared to the domesticated strain. They had a high GC stress response and a high OSR when kept under predictable food supply. Wild-strain parents reacted to prenatal unpredictable food supply by lowering their offspring's GC stress response, which potentially lowered GC-induced oxidative pressure. No such pattern was evident in the domesticated birds. Irrespective of strain and prenatal feeding scheme, post-natal unpredictable food supply boosted immune indices, and GC stress response was negatively related to antibody response in females and to mitochondrial superoxide production. Wild-strain grey partridge showed fitness-relevant physiological advantages and appeared to prepare their offspring for the prospective environment. Negative relationships between GC stress response, immunity and oxidative indices imply a pivotal role of an organism's oxidative balance and support the importance of considering multiple physiological systems simultaneously.

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The aim of this work was to use the Urinary Distress Inventory (UDI-6) and Incontinence Impact Quality of Life (IIQ-7) questionnaires to compare 3 surgical techniques for stress urinary incontinence: the transvaginal tape (TVT) (105 women), the transobturator tape outside-in (TOT) (43 women), and the transvaginal tape-obturator inside-out (TVT-O) (54 women). There were no significant differences in frequent urination, urine leakage related to the feeling of urgency, urine leakage related to physical activity, or small amounts of urine leakage. TVT-operated women had a lower percentage of micturition difficulties compared with TOT women. TVT-O-operated women described slight discomfort in the genital area compared with the TVT technique, but this difference was not significant when compared with the TOT technique. When utilizing the UDI-6 and IIQ-7 scoring modifications before and after surgery, no difference among these 3 techniques is apparent.