Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “STRESS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 721 records · Page 40Linked to original sources

Oxidative stress induces E. coli aryl polyene expression, sensitizing the bacterial stress response and modulating the redox environment of innate immune cells.

UNLABELLED: Aryl polyenes (APEs) are specialized polyunsaturated outer membrane lipids that protect their producers from oxidative stress and contribute to biofilm formation. APEs are produced by an abundant biosynthetic gene cluster (BGC) family conserved across Gram-negative bacterial clades. The APE biosynthesis pathway involves 11 different enzymes and culminates in the attachment of APEs to an anchor molecule in the Gram-negative outer membrane. Unlike most other small molecule BGCs, the APE BGC does not contain a dedicated regulatory gene that controls the production of its metabolically costly compounds. Building from our prior observations of APEs' role in acute oxidative stress protection, we use a uropathogenic Escherichia coli (UPEC) strain to show that APE expression conveys a potential competitive advantage characterized by increased early-stage growth, sensitization of the bacterial oxidative stress response, and dampening of the redox stress of innate immune cells after in vitro infection. Our data indicate that APEs could act as a UPEC fitness factor, and in future work, we aim to study their contribution to overall bacterial pathogenicity and survival, as well as how APEs could facilitate the transition from an oxygen-poor environment, such as the gut, to the oxygen-rich environment of the urinary tract. IMPORTANCE: Bacterial pathogens use various mechanisms to achieve a competitive advantage under harsh conditions, such as during interactions with their host. We studied the function of aryl polyenes (APEs), specialized polyunsaturated fatty acids in the outer membrane, in the context of a uropathogenic E. coli strain. APE expression is induced by an oxidative environment and contributes to early-stage growth and sensitization of the oxidative stress response. Furthermore, APE-expressing E. coli dampen the intracellular oxidative milieu of target host phagocytes. These findings suggest a role for APEs as a fitness factor and create opportunities to study their in vivo function and explore them as a potential drug target.

Oxidative Stress↗

Oxidative stress-induced dysregulation of arteriolar wall shear stress and blood pressure in hyperhomocysteinemia is prevented by chronic vitamin C treatment.

We aimed to test the hypothesis that an enhanced level of reactive oxygen species (ROS) is primarily responsible for the impairment of nitric oxide (NO)-mediated regulation of arteriolar wall shear stress (WSS) in hyperhomocysteinemia (HHcy). Thus flow/WSS-induced dilations of pressurized gracilis muscle arterioles (basal diameter: approximately 170 microm) isolated from control (serum Hcy: 6 +/- 1 microM), methionine diet-induced HHcy rats (4 wk, serum Hcy: 30 +/- 6 microM), and HHcy rats treated with vitamin C, a known antioxidant (4 wk, 150 mg. kg body wt-1.day-1; serum Hcy: 32 +/- 10 microM), were investigated. In vessels of HHcy rats, increases in intraluminal flow/WSS-induced dilations were converted to constrictions. Constrictions were unaffected by inhibition of NO synthesis by N omega-nitro-L-arginine methyl ester (L-NAME). Vitamin C treatment of HHcy rats reversed the WSS-induced arteriolar constrictions to L-NAME-sensitive dilations but did not affect control responses. Similar changes in responses were obtained for the calcium ionophore A-23187. In addition, diastolic and mean arterial blood pressure and serum 8-isoprostane levels (a marker of in vivo oxidative stress) were significantly elevated in rats with HHcy, changes that were normalized by vitamin C treatment. Taken together, our data show that in chronic HHcy long-term vitamin C treatment, by decreasing oxidative stress in vivo, enhanced NO bioavailability, restored the regulation of shear stress in arterioles, and normalized systemic blood pressure. Thus our study provides evidence that oxidative stress is an important in vivo mechanism that is primarily responsible for the development of endothelial dysregulation of WSS in HHcy.

Animals↗

Brain environment interactions: stress, posttraumatic stress disorder, and the need for a postmortem brain collection.

Stress, especially the extreme stress of traumatic events, can alter both neurobiology and behavior. Such extreme environmental situations provide a useful model for understanding environmental influences on human biology and behavior. This paper will review some of the evidence of brain alterations that occur with exposure to environmental stress. This will include recent studies using neuroimaging and will address the need for histological confirmation of imaging study results. We will review the current scientific approaches to understanding brain environment interactions, and then make the case for the collection and study of postmortem brain tissue for the advancement of our understanding of the effects of environment on the brain. Creating a brain tissue collection specifically for the investigation of the effects of extreme environmental stressors fills a gap in the current research; it will provide another of the important pieces to the puzzle that constitutes the scientific investigation of negative effects of environmental exposures. Such a resource will facilitate new discoveries related to the psychiatric illnesses of acute stress disorder and posttraumatic stress disorder, and can enable scientists to correlate structural and functional imaging findings with tissue abnormalities, which is essential to validate the results of recent imaging studies.

Acoustic Stimulation↗

The Psoriasis Life Stress Inventory: a preliminary index of psoriasis-related stress.

The psychosocial impact of psoriasis may result in significant daily stress for the patient. We present a questionnaire, the Psoriasis Life Stress Inventory (PLSI), which provides a rating of psoriasis-related stress. Two hundred and seventeen psoriasis patients endorsed a list of psoriasis-related items they had experienced over the previous one month and rated the degree of stress associated with each item on a 4-point scale. The final version of the PLSI consisted of 15 items, each of which had been endorsed by at least 15% of patients. A PLSI score of > or = 10 (range 0 to 43) delineated patients with greater overall psoriasis severity (p = 0.007), more cosmetically disfiguring psoriasis (p < 0.01), greater number of flare-ups of psoriasis (p = 0.009) and greater pruritus severity (p = 0.001). This preliminary instrument provides a clinically useful index of psoriasis-related stress and needs to be tested among patients from different centers and in prospective studies.

Activities of Daily Living↗

Intracellular stress transmission through actin stress fiber network in adherent vascular cells.

Intracellular stress transmission through subcellular structural components has been proposed to affect activation of localized mechano-sensing sites such as focal adhesions in adherent cells. Previous studies reported that physiological extracellular forces produced heterogeneous spatial distributions of cytoplasmic strain. However, mechanical signaling pathway involved in intracellular force transmission through basal actin stress fibers (SFs), a mechano-responsive cytoskeletal structure, remains elusive. In the present study, we investigated force balance within the basal SFs of cultured smooth muscle cells and endothelial cells by (i) removing the cell membrane and cytoplasmic constituents except for materials physically attaching to the substrate (i.e., SF-focal adhesion complexities) or (ii) dislodging either mechanically or chemically the cell processes of the cells expressing fluorescent proteins-labeled actin and focal adhesions in order, to examine stress-release-induced deformation of the basal SFs. The result showed that a removal of mechanical restrictions for SFs resulted in a decrease in the length of the remaining SFs, which means SFs bear tension. In addition, a release of the preexisting tension in a single SF was transmitted to another SF physically linked to the former, but not transmitted to the other ones physically independent of the former, suggesting that the prestress is balanced in tensed SF networks. These results support a hypothesis regarding cell structural architecture that physiological extracellular forces can produce in the basal SF network a directional intracellular stress or strain distribution. Therefore, consideration of the coexistence of the directional stretching strain along the axial direction of SFs and the heterogeneous strain in the other cytoplasmic region will be essential for understanding intracellular stress transmission in the adherent cells.

Actins↗

[Stress, endocrine, and immune system; stress induces the onset of autoimmune diseases].

Stress can affect endocrine and immune function. In this paper, we reviewed the interaction between stress and Graves disease, which is induced by thyroid-stimulating autoantibodies. Psychological stress was reported to be a risk factor for Graves' disease, although the mechanism by which stress induces autoimmune disease remains unknown. Moreover, we found that other stress, such as delivery and allergic rhinitis can induce the onset of Graves' disease. Immune rebound after delivery and the overproduction of Th 2 (type 2 helper T cells)-derived cytokines after an attack of allergic rhinitis might help produce thyroid-stimulating autoantibodies.

Autoimmune Diseases↗

From stress signaling to yield stability: physiological and molecular mechanisms of wheat resilience to heat and drought stress.

Wheat resilience depends on coordinated signaling, reproductive protection, and source-sink regulation, providing a framework to breed robust trait combinations that stabilize yield under combined heat and drought. Climate change is increasing the frequency and severity of heat and drought events, posing a major threat to wheat productivity, yield stability, and food security. Because these stresses often coincide in the field, their combined effects can impair growth, reproductive development, grain filling, and final yield more severely than either stress alone. Wheat resilience under such conditions depends on coordinated physiological adjustment and molecular regulation that sustain cellular homeostasis, protect reproductive tissues, and preserve yield-related traits. This review synthesizes current knowledge on the physiological and molecular bases of wheat resilience to heat and drought, with emphasis on their combined effects. We discuss major physiological responses, including photosynthetic adjustment, stomatal regulation, canopy cooling, osmotic balance, antioxidant defense, membrane stability, and source-sink coordination. We also examine key regulatory pathways involved in stress perception and adaptation, including calcium and reactive oxygen species signaling, mitogen-activated protein kinase cascades, phytohormonal crosstalk, transcriptional regulation, heat shock proteins, late embryogenesis abundant proteins, and osmoprotective and redox-associated pathways. In addition, we highlight the growing contribution of transcriptomics, proteomics, metabolomics, and phenomics to the identification of candidate genes, biomarkers, and adaptive traits. Finally, we consider how mechanistic insights can be translated into wheat improvement through molecular markers, genomic selection, gene editing, and climate-realistic phenotyping. An integrated understanding of stress signaling and adaptive trait deployment will be essential for developing wheat cultivars with improved resilience and yield stability under future climates.

Triticum↗

Acute stress disorder, subsequent posttraumatic stress disorder and depression after a series of typhoons.

From August to November 1992, five typhoons struck the U.S. Pacific island territory of Guam. Three hundred and twenty subjects exposed to all five typhoons participated in a population survey measuring their acute stress symptoms and subsequent diagnoses of posttraumatic stress disorder (PTSD) and depression. A 23-item scale approximating the new DSM-IV diagnosis of acute stress disorder (ASD) was used to classify subjects into three groups based on their symptoms one week after the first typhoon: (1) probable ASD, (2) an early traumatic stress response (ETSR) of fear, intrusion, avoidance, and arousal, without dissociation, and (3) no acute diagnosis. A multi-dimensional measure of PTSD and the Zung Self-Rating Depression Scale were used to assess PTSD and depression 8 months after the first storm. The point prevalence of ASD at one week was 7.2%. An additional 15% of subjects had ETSR. Subjects with probable ASD at one week had significantly increased rates of PTSD and somewhat higher rates of depression at 8 months than those without ASD. In contrast, subjects with ETSR at one week did not have a poorer outcome than those with no acute diagnosis. These findings suggest that ASD is prognostically important, but also indicate that all acute stress symptoms do not have the same discriminative value. In this study, the acute dissociative symptoms of emotional numbing and derealization differentiated highly symptomatic subjects at risk for subsequent psychopathology (ASD) from others who were highly symptomatic at one week, but then had a more benign, posttraumatic course (ETSR).

Adult↗

Circuits and systems in stress. II. Applications to neurobiology and treatment in posttraumatic stress disorder.

This paper follows the preclinical work on the effects of stress on neurobiological and neuroendocrine systems and provides a comprehensive working model for understanding the pathophysiology of posttraumatic stress disorder (PTSD). Studies of the neurobiology of PTSD in clinical populations are reviewed. Specific brain areas that play an important role in a variety of types of memory are also preferentially affected by stress, including hippocampus, amygdala, medial prefrontal cortex, and cingulate. This review indicates the involvement of these brain systems in the stress response, and in learning and memory. Affected systems in the neural circuitry of PTSD are reviewed (hypothalamic-pituitary-adrenal axis (HPA-axis), catecholaminergic and serotonergic systems, endogenous benzodiazepines, neuropeptides, hypothalamic-pituitary-thyroid axis (HPT-axis), and neuro-immunological alterations) as well as changes found with structural and functional neuroimaging methods. Converging evidence has emphasized the role of early-life trauma in the development of PTSD and other trauma-related disorders. Current and new targets for systems that play a role in the neural circuitry of PTSD are discussed. This material provides a basis for understanding the psychopathology of stress-related disorders, in particular PTSD.

Animals↗

Prenatal stress has long-term effects on behavioral responses to stress in juvenile rhesus monkeys.

The effect of maternal psychological disturbance during pregnancy on postnatal responses of the offspring to stressful events was investigated in juvenile rhesus monkeys. Six pregnant monkeys were repeatedly removed from their home cages and briefly exposed to unpredictable noise during mid to late gestation (Days 90-145 postconception). Six undisturbed pregnant mothers served as controls. Behavioral data were later collected from the 18-month-old offspring under a baseline and four progressively stressful conditions. Social behaviors were considerably more affected by prenatal treatment than nonsocial behaviors. Prenatally stressed offspring showed more abnormal social behavior (mutual clinging) and less normal social behavior (proximity, contact) than controls. These results suggest that offspring of mothers stressed during pregnancy may show enhanced responsivity to stressors later in life, and concur with rodent findings indicating that prenatal stress may have long-term effects on behavioral reactivity.

Animals↗

Teacher stress and coping strategies used to reduce stress.

This pilot study investigated teachers' symptoms of stress and their coping strategies. Measurements of 'stress levels' and 'coping strategies' used were acquired by constructing a questionnaire made up of four individual standardized questionnaires. The data were analysed by a series of correlational analyses that highlighted significant relationships between ways of coping and levels of distress. Differences between the stress-related areas were measured using the Friedman test and Wilcoxon signed rank test for hierarchy. The findings implied that 'escape avoidance', 'accepting responsibility' and 'uncontrolled aggression' were used as negative coping strategies and only one strategy, 'exercise', was indicated to be an effective way of coping. The teachers' strategies were examined for similarities and differences with those recommended by occupational therapists. This pilot study was limited to two schools and it is recommended that it be extended to better generalize the results. Furthermore, ways of coping, as measured by psychological measures, do not seem to reduce stress so it is possible that the activity-based Stress Management Questionnaire, as advocated by Stein et al. (2003), might be more advantageous.

Adaptation, Psychological↗

Prior stress attenuates the analgesic response but sensitizes the corticosterone and cortical dopamine responses to stress 10 days later.

This study demonstrates that pre-exposure to stress influences subsequent effects of stress on pain sensitivity (stress-induced analgesia) and on plasma corticosterone and brain catecholamine activity. Animals exposed to a 30 min shock session (S1 = 8, 5.0 s shocks) 10 days earlier showed a significant attenuation of shock-induced analgesia, as measured by increased latency of tail withdrawal from a hot water bath immediately after a 40 s, 1.6 mA footshock (S2). Animals exposed to shock 10 days before testing also exhibited a higher plasma corticosterone response to testing than did all other groups. Norepinephrine (NE) levels in the frontal cortex and dopamine (DA) and dihydroxyphenylacetic acid (DOPAC) levels in the frontal cortex and nucleus accumbens were not altered in any group. However, the DOPAC/DA ratio in the frontal cortex was increased by analgesia testing, and this increase was enhanced only by the combination of shock 10 days before testing and shock immediately before the test (S1 + S2). These results are consistent with previous reports from this laboratory which indicate that an animal's acute response to stress is strongly influenced by its past history of stress.

3,4-Dihydroxyphenylacetic Acid↗

Improving the diagnosis of genuine stress incontinence in symptomatic women with negative cough stress test: the Distal Urethral Electrical Conductance test (DUEC) revisited.

This retrospective descriptive study was performed to assess the practice of using the distal urethral electrical conductance (DUEC) test to objectively demonstrate urinary incontinence in symptomatic women with a negative cough stress test on examination. One hundred women had stable bladders on cystometry (CMG). Genuine stress incontinence (GSI) was diagnosed during CMG in 45 (45%). DUEC performed prior to cystometry had revealed stress incontinence in an additional 13 with negative CMG, thereby improving the diagnosis of GSI by 13%. The test detected urge incontinence in one (1%). The DUEC test improves the detection of stress incontinence. However, it should not be considered as an alternative to cystometry, but as an additional test when stress incontinence cannot be demonstrated clinically.

Cough↗

The ability of history and a negative cough stress test to detect occult stress incontinence in patients undergoing surgical repair of advanced pelvic organ prolapse.

To determine if a negative preoperative reduction cough stress test is a viable method of detecting occult stress incontinence or urge incontinence in women undergoing surgical repair of advanced pelvic organ prolapse. A retrospective chart review was done on all patients who denied any urinary complaints and had repair of advanced pelvic organ prolapse, grade two or greater, without the addition of an anti-incontinence procedure. Additionally patients had a simple office filling study done at the time of initial examination that failed to show the sign of stress incontinence or detrusor instability. Any urinary dysfunction that developed postoperatively was noted. A total of 53 patients met the inclusion criteria. Of these patients, one patient (1.9%) developed genuine stress incontinence, and one patient complained of urgency (1.9%). Patients without urinary complaints and a negative office filling study, who were present for surgical correction of advanced pelvic organ prolapse, have a low incidence of developing occult stress incontinence. Further work-up would not be cost effective.

Comorbidity↗

Impairments produced by amphetamine and stress on memory storage are reduced following a chronic stressful experience.

Post-training administration of the psycho-stimulant, amphetamine or post-trial exposure to restraint stress impaired retention of an inhibitory avoidance response in DBA/2 (DBA) mice. The effect of amphetamine was dose-dependent (1-3 mg/kg) whilst the effect of stress depended on restraint duration (15, 30, or 60 min). Both effects on retention performance appeared to be due to an effect on memory consolidation. In fact, they were observed when the drug and the stressor were experienced at short, but not long, periods of time after training, which is when the memory trace is susceptible to modulation. Moreover, these effects could not be ascribed to a rewarding or non-specific action of the two treatments on retention performance, as the latencies during the retention test of those mice that had not received a footshock during the training, were not affected by the post-training treatments. Administration of either D1 (SCH23390) or D2 [(-)-sulpiride] dopamine (DA) receptor against prior to amphetamine injection or stress exposure antagonized the impairing effects of both treatments. These data indicate that brain dopamine was involved in both cases. Finally, when mice were food restricted for 13 days than allowed free access to food for 24 h before training, either the effects of amphetamine or restraint stress were reduced. Food restricted mice did not differ from control for stepthrough latencies either on the training or the test days, indicating the absence of amnesic or otherwise impairing effects of the experimental procedure per se. Instead, the results indicated hyposensitization to the effects of amphetamine and stress on memory consolidation in food restricted animals.

Amphetamine↗

Diauxic shift-induced stress resistance against hydroperoxides in Saccharomyces cerevisiae is not an adaptive stress response and does not depend on functional mitochondria.

Respiring Saccharomyces cerevisiae cells grown on a non-fermentable carbon source are intrinsically more resistant to several stresses, including oxidative stress. The mechanisms leading to increased stress resistance are not yet well understood. Active mitochondria are the major source of intracellular reactive oxygen species (ROS), which could cause the up-regulation of the antioxidant defense systems. We investigated the role of mitochondria in the intrinsic stress resistance against the hydroperoxides H2O2 and tert-butylhydroperoxide 4 h after a shift in carbon source. We found that, independently of functional mitochondria, the yeast acquired the intrinsic resistance of respiring cells against hydroperoxides solely as a response to a change of carbon source in the growth medium. Furthermore, utilizing reporter gene fusion constructs, we monitored the expression of the gamma-glutamylcysteinyl synthetase (encoded by GSH1) and the two superoxide dismutases (encoded by SOD1 and SOD2) during the metabolic transition from fermentation to respiration; and we detected an up-regulation of all three genes during the diauxic shift. Overall available data allowed us to propose that the antioxidant system of S. cerevisiae could be considered as a class of genes under glucose/carbon catabolite regulation. This control system is different from the well-known adaptive response to oxidative stress.

Antioxidants↗

The effects of a mindfulness meditation-based stress reduction program on mood and symptoms of stress in cancer outpatients: 6-month follow-up.

The goals of this work were to assess the effects of participation in a mindfulness meditation-based stress reduction program on mood disturbance and symptoms of stress in cancer outpatients immediately after and 6 months after program completion. A convenience sample of eligible cancer patients were enrolled after they had given informed consent. All patients completed the Profile of Mood States (POMS) and Symptoms of Stress Inventory (SOSI) both before and after the intervention and 6 months later. The intervention consisted of a mindfulness meditation group lasting 1.5 h each week for 7 weeks, plus daily home meditation practice. A total of 89 patients, average age 51, provided pre-intervention data. Eighty patients provided post-intervention data, and 54 completed the 6-month follow-up The participants were heterogeneous with respect to type and stage of cancer. Patients' scores decreased significantly from before to after the intervention on the POMS and SOSI total scores and most subscales, indicating less mood disturbance and fewer symptoms of stress, and these improvements were maintained at the 6-month follow-up. More advanced stages of cancer were associated with less initial mood disturbance, while more home practice and higher initial POMS scores predicted improvements on the POMS between the pre- and post-intervention scores. Female gender and more education were associated with higher initial SOSI scores, and improvements on the SOSI were predicted by more education and greater initial mood disturbance. This program was effective in decreasing mood disturbance and stress symptoms for up to 6 months in both male and female patients with a wide variety of cancer diagnoses, stages of illness, and educational background, and with disparate ages.

Female↗

The stress-vulnerability hypothesis in psychotic disorders: focus on the stress response systems.

The vulnerabilty stress model is an intriguing concept to look into the etiology of psychotic disorders and, in particular, into the "nature nurture" principle. That stress affects a vulnerable nature may be obvious, but its mechanism is not well understood, and many questions remain to be answered, let alone how to define "vulnerability". The present review tries to focus on the core issues of the vulnerability stress concept--identifying vulnerability, the way stress interferes with it, and the possiblilities of modulating their interaction. Attention is drawn to the biologic stress response systems, the autonomic nervous system (ANS), the hypothalamic pituitary adrenal (HPA) system, and the immune system, and highlights the plasticity of the HPA system as the mediator of adaptation.

Affect↗