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PubMed2005

AtHsfA2 modulates expression of stress responsive genes and enhances tolerance to heat and oxidative stress in Arabidopsis.

There is increasing evidence for considerable interlinking between the responses to heat stress and oxidative stress, and recent researches suggest heat shock transcription factors (Hsfs) play an important role in linking heat shock with oxidative stress signals. In this paper, we present evidence that AtHsfA2 modulated expression of stress responsive genes and enhanced tolerance to heat and oxidative stress in Arabidopsis. Using Northern blot and quantitative RT-PCR analysis, we demonstrated that the expression of AtHsfA2 was induced by not only HS but also oxidative stress. By functional analysis of AtHsfA2 knockout mutants and AtHsfA2 overexpressing transgenic plants, we also demonstrated that the mutants displayed reduced the basal and acquired thermotolerance as well as oxidative stress tolerance but the overexpression lines displayed increased tolerance to these stress. The phenotypes correlated with the expression of some Hsps and APX1, ion leakage, H202 level and degree of oxidative injuries. These results showed that, by modulated expression of stress responsive genes, AtHsfA2 enhanced tolerance to heat and oxidative stress in Arabidopsis. So we suggest that AtHsfA2 plays an important role in linking heat shock with oxidative stress signals.

Arabidopsis↗
PubMed1987

[Sexual differentiation of social play and copulatory behavior in prenatally stressed male and female offspring of the rat: the influence of simultaneous treatment by tyrosine during exposure to prenatal stress].

The environmental stress in the late gestational life has been reported to induce impairments of androgen-dependent sex differentiation of the rat brain. This study was performed to investigate the effects of prenatal stress on the features of gender role behavior and copulatory behavior which are masculinized by perinatal androgens. Further, a possible counteraction of tyrosine to the long-term effects of prenatal stress was examined, because the supplementation of amino-acid precursor of catecholamines during the stress is known to maintain the content of catecholamines in the brain, which is considered to contribute to the differentiation of the brain. Time-mated pregnant females were subjected to the forced immobilization stress daily from day 15 of pregnancy to the day of delivery, and they received simultaneous i.p. injections of either tyrosine methylester HCl (200 mg/kg) or saline, less than 60 minutes before stress. Social play in the peripubescent period was observed in the male and female offspring. After maturation, they were castrated and male copulatory behavior under androgen-substitution was tested in the male offspring, and female copulatory behavior under estrogen-substitution was tested in the female offspring. In the male offspring, prenatal stress caused a significant depletion of social play as well as male copulatory behavior, showing the demasculinization of gender role centers and mating centers. In the female offspring exposed to the prenatal stress, a significant increase of social play was observed. And their lordosis quotient did not alter, but a reduced attractivity against male partner was found. These results in the female offspring suggest some extent of masculinization occurred in both centers, probably due to the increase of androgens derived from the adrenal glands when stressed. Tyrosine seemed to reduce the engagement of social play in both sexes, independently of the prenatal stress. On the other hand, tyrosine prevented, at least partially, the long-term effects of prenatal stress in copulatory behavior which were observed in this study. Tyrosine itself had no effect on copulatory behavior. The apparent counteraction of tyrosine in copulatory behavior suggests a positive involvement of catecholamines, especially norepinephrine, in the process of masculinization of the mating centers. The different action of tyrosine to these behaviors may reflect the fact that the different regions of the brain and separate mechanisms are responsible for the sexual differentiation of social play and copulatory behavior.

Animals↗
PubMed2003

Both stress experience and age determine the impairment or enhancement effect of stress on spatial memory retrieval.

It has been documented that stress or glucocorticoids have conflicting effects on memory under different conditions. However, it is not fully understood why stress can either impair or enhance memory. Here, we have examined the performance of six age groups of Wistar rats in a water maze spatial task to evaluate the effects of stress under different conditions. We found that the impairment or enhancement effect of an 'elevated platform' (EP) stress on memory was dependent on previous stress experience and on age. EP stress impaired memory retrieval in water maze naive animals, but enhanced rather than impaired memory retrieval in young water maze stress-experienced animals. Furthermore, exogenously applied corticosterone or foot shock stress before water maze training prevented the impairment of memory retrieval that should be induced by treatment with corticosterone or foot shock before the 'probe trial'. Again, memory retrieval was enhanced in young animals under these conditions, and this enhancement can be prevented by the glucocorticoid receptor antagonist RU 38486. Thus, glucocorticoid receptor activation not only induced impairment of memory but also increased the capacity of young animals to overcome a later stress. The present findings suggest that the effect of stress on memory can be switched from impairment to enhancement dependent on both stress experience and age.

Aging↗
PubMed2006

Urban stress and health in developing countries: development and validation of a neighborhood stress index for India.

Stress caused by chronic difficulties encountered by people residing in poor urban neighborhoods is associated with health problems and disease in developed countries, but the relationship between neighborhood stress and health in developing nations, such as India, has not been assessed. In this study, the authors administered the City Stress Inventory, a self-report measure assessing stress experienced as a function of environmental conditions unique to living in large cities that was validated in the United States, to 163 high school students in New Delhi, India. Components of urban stress in India, with some modifications, appear to be similar to components of urban stress reported by adolescents in the United States. Urban stress was predictive of high blood pressure as reported by the adolescents 'parents. In addition, urban stress also predicted health habits, such as chewing tobacco and alcohol use, and psychosocial characteristics, such as hostility. Adolescents' reports of parental stress concerning money and social pressures were also associated with city stress. The current study indicates that the City Stress Inventory is valid in an Indian sample and is predictive of health problems.

Adolescent↗
PubMed1999

[Coping with stress and personality structure in patients with and without stress-associated symptoms of gastroesophageal reflux].

BACKGROUND: Psychological aspects like stress, emotions or personality are known to affect the severity of symptoms of gastroesophageal reflux disease (GERD). The aim of the present study was to evaluate differences in coping with stress, structure of personality and also objective and subjective parameters of patients with or without a stress-related perception of symptoms in GERD. METHODS: 100 patients which underwent laparoscopic antireflux surgery at our department of surgery were included in this study. All patients answered questionnaires to evaluate their coping with stress (SVF), structure of personality (FPI-R) and quality of life (GILQI) pre- and postoperatively. Also data of physiological parameters like manometry, 24-hours pH monitoring, endoscopy and clinical history were included. Patients were divided into two groups: one with and one without a stress-related perception of symptoms. RESULTS: 46 out of 100 patients declared stress-related symptoms of reflux (group 1) and 54 out of 100 had no influence of stress to their reflux disease (group two). Those two groups showed significant differences (p < .05) in some coping strategies and their personality: Coping with stress (SVF): Trial to control the situations (18.3 vs. 13.1), trial to control reactions (18.2 vs. 13.3), requirement of social support (9.7 vs. 14.8), tendency to escape (7.7 vs. 13.9) and aggression (13.1 vs. 7.6); structure of personality (FPI-R): Standard of performance (10.8 vs. 7.2), stress (9.8 vs. 4.7) and physical discomfort (7.6 vs. 4.6). We also found significant (p < .05) differences in pre- and postoperative quality of life (GILQI: preoperative 86.3 vs. 98.5 points; postoperative 117.9 vs. 128.2 points) and the day-time of reflux perception. There were no differences in physiological parameters. CONCLUSION: These findings point out that there are no physiological differences between the two groups with or without stress-related symptoms in GERD. But we found significant differences in psychological factors. Therefore we suggest that preoperative psychological interventions may optimize the subjective outcome after antireflux surgery in patients with a stress-related perception of symptoms.

Adaptation, Psychological↗
PubMed2001

Occupational stress and psychiatric illness in the military: investigation of the relationship between occupational stress and mental illness among military mental health patients.

OBJECTIVE: This was a pilot study aimed at gathering preliminary data on the relationship between occupational stress and mental illness among military personnel. The primary goal of this study was to determine to what extent military mental health patients report suffering from significant occupational stress. METHODS: Eighty-five active duty military mental health outpatients at the Wilford Hall U.S. Air Force Medical Center mental health clinic answered a 65-item survey that included items on the perception of occupational stress and reported life changes. Participation in this cross-sectional study was anonymous, voluntary, and random. The 85 participants represent 83% of those surveyed and approximately 10% of the clinic's total population of military mental health outpatients. The survey incorporated the 43-item Schedule of Recent Experiences (SRE). By adding the weighted values assigned to the 43 items, each respondent was given an SRE score, which is a measure of overall stress that has been shown to be predictive of future illnesses. RESULTS: A majority (60%) reported suffering from significant work stress. A majority (52%) reported that work stress was causing them significant emotional distress. Almost half (42.5%) reported that work stress was a significant contributor to the onset of their mental illness. The average SRE score for all respondents was 266, reflecting increased risk for future illnesses. Generic work stressors were endorsed more frequently than military-specific stressors. CONCLUSIONS: The results reveal that this population of military mental health clinic outpatients perceived that work stress had a strong negative effect on their emotional health. These results raise the possibility that work stress could be a significant occupational health hazard in the U.S. military, a possibility that warrants further investigation. By gathering additional data on the relationship between work stress and emotional health in the military, interventions can be planned to mitigate the effect of stress caused by the military work environment on the mental health of military personnel.

Adult↗
PubMed2005

Stress-induced decrease of granule cell proliferation in adult rat hippocampus: assessment of granule cell proliferation using high doses of bromodeoxyuridine before and after restraint stress.

Stress is known to inhibit granule cell proliferation in the hippocampus. However, recent studies suggest that the commonly used dose of bromodeoxyuridine (BrdU) is insufficient to label all fractions of granule cells. Furthermore, stress-induced changes in BrdU availability may influence the labeling of newly born cells. To investigate whether changes in BrdU availability affect measurements of stress-induced granule cell proliferation, granule cell proliferation was assessed using injection of high doses of BrdU before and after restraint stress lasting 1 h. In addition, to determine whether stress-induced changes in plasma corticosterone levels were influenced by the BrdU, time-dependent changes in plasma corticosterone levels over 2 h after BrdU injection were compared with total accumulated plasma corticosterone levels [as determined by areas under the curve (AUC)]. Restraint stress significantly reduced the numbers of BrdU-labeled cells and clusters in the granule cell layer (GCL) of rats that received BrdU after stress, and decreases of similar magnitude were observed when the rats were given BrdU before stress. BrdU injection enhanced the stress-induced plasma corticosterone response, but there was no difference between the mean AUCs of plasma corticosterone levels of animals injected with BrdU before or after stress. These observations suggest that restraint stress decreases granule cell proliferation, and that this may be influenced by the extent and duration of plasma corticosterone increases rather than by changes in the availability of BrdU.

Animals↗
PubMed2002

Salt stress and hyperosmotic stress regulate the expression of different sets of genes in Synechocystis sp. PCC 6803.

Acclimation of microorganisms to environmental stress is closely related to the expression of various genes. We report here that salt stress and hyperosmotic stress have different effects on the cytoplasmic volume and gene expression in Synechocystis sp. PCC 6803. DNA microarray analysis indicated that salt stress strongly induced the genes for some ribosomal proteins. Hyperosmotic stress strongly induced the genes for 3-ketoacyl-acyl carrier protein reductase and rare lipoprotein A. Genes whose expression was induced both by salt stress and by hyperosmotic stress included those for heat-shock proteins and the enzymes for the synthesis of glucosylglycerol. We also found that each kind of stress induced a number of genes for proteins of unknown function. Our findings suggest that Synechocystis recognizes salt stress and hyperosmotic stress as different stimuli, although mechanisms common to the responses to each form of stress might also contribute to gene expression.

3-Oxoacyl-(Acyl-Carrier-Protein) Reductase↗
PubMed1990

Ontogeny of behavioral and hormonal responses to stress in prenatally stressed male rat pups.

Effects of prenatal stress on stress-induced behavioral and hormonal responses were investigated in preweanling rats at two ages. Prenatal stress treatments involved the application of uncontrollable electric shocks to pregnant rats every other day throughout gestation. Offspring of undisturbed rats in home cages served as controls. When male pups were 14 and 21 days old, ultrasonic vocalizations and freezing were recorded in 10-min tests involving isolation, and isolation with the application of electric foot shocks at either 0.5- or 2.0-mA intensity. Immediately before and after each test, tail-flick latencies were measured in order to assess alterations in stress-induced analgesia. Stress-induced secretion of ACTH was measured in plasma obtained after the second tail-flick test. Results indicated that 14-day-old prenatally stressed pups emitted significantly fewer ultrasonic vocalizations and exhibited significantly lower percent increases in tail-flick latencies than control pups. Plasma ACTH, however, was significantly elevated in prenatally stressed rats, suggesting that exposure to different tests was a stress-inducing event. At 21 days of age, prenatally stressed rats no longer differed significantly from control males in the exhibition of ultrasonic vocalizations, defensive freezing, and tail-flick latencies. Plasma ACTH content, however, was significantly lower in prenatally stressed than control males after exposure to the isolation with 2.0-mA shock test. The involvement of motivational, maturational, and mediational factors is examined in order to account for these age-dependent and stressor-dependent differences in behavioral and hormonal responses occurring between prenatally stressed and control pups.

Adrenocorticotropic Hormone↗
PubMed1998

Oblique alignment of stress fibers in cells reduces the mechanical stress in cyclically deforming fields.

The stress fiber (bundles of actin filaments) is one of the most prominent cytoskeletal components that contributes to the maintenance of cell architecture. It has generally been believed that upon cyclic stretching, both cells and their stress fibers become perpendicularly aligned to the direction of stretching. However, using our newly developed stretching device, we have recently found the contrary evidence that stress fibers in endothelial cells rapidly become rearranged at a specific oblique angle relative to the direction of stretching [Takemasa, T., K. Sugimoto, K. Yamashita: Exp. Cell Res. 230, 407-410 (1997)]. In light of this finding, we attempted to establish the explanation for such a phenomenon. First, we investigated the effects of possible modulators on the angle of the stress fibers; those were, modification of the stretching program, dependency of extracellular matrix types, and their reproducibility in other cell species. However, it seemed that the orientation was solely depending on the stretching amplitude applied. Next, we analyzed alterations in stress fiber length during loading tests using two kinds of deforming experiment systems. It was thus revealed that stress fibers aligned at a particular angle so as to minimize their length alterations in cyclic deforming fields. Rearrangement of the stress fibers at this angle probably occurs as a result of avoiding compressive stress and may be interpreted as a way of reducing the mechanical stress to which they are subjected during the deformation. This hypothesis well explains the reason not only for the survival of the stress fibers at a particular oblique angle, but also for the reduced numbers of stress fibers found at the other angles on cyclic deforming fields.

Actins↗
PubMed2001

Constitutive over-expression of AtGSK1 induces NaCl stress responses in the absence of NaCl stress and results in enhanced NaCl tolerance in Arabidopsis.

GSK3/shaggy-like protein kinases have been shown to play diverse roles in development and signal transduction pathways in various organisms. An Arabidopsis homologue of GSK3/shaggy-like kinase, AtGSK1, has been shown to be involved in NaCl stress responses. In order to further clarify the role of AtGSK1 in NaCl stress responses in plants, we generated transgenic Arabidopsis plants that over-expressed AtGSK1 mRNA. These plants showed enhanced resistance to NaCl stress when assayed either as whole plants or by measurement of root growth on NaCl plates. In addition, AtGSK1 transgenic plants in the absence of NaCl stress showed phenotypic changes, such as accumulation of anthocyanin, that were similar to those observed in wild-type plants under NaCl stress. Transgenic plants accumulated 30-50% more Na+ than did wild-type plants when subjected to NaCl stress, and Ca2+ content was increased by 15-30% in the transgenic plants regardless of the NaCl stress level. Northern blotting revealed that AtGSK1 over-expression induced expression of the NaCl stress-responsive genes AtCP1, RD29A and CHS1 in the absence of NaCl stress. In addition, AtCBL1 and AtCP1 were super-induced in the NaCl-stressed transgenic plants. Taken together, these results suggest that AtGSK1 is involved in the signal transduction pathway(s) of NaCl stress responses in Arabidopsis.

Adaptation, Physiological↗
PubMed2003

Proline induces the expression of salt-stress-responsive proteins and may improve the adaptation of Pancratium maritimum L. to salt-stress.

Proline is an important component of salt-stress responses of plants. In this study the role of proline as part of salt-stress signalling in the desert plant Pancratium maritimum L. was examined. The data showed that salt-stress brought about a reduction of the growth and protein content, particularly at 300 mM NaCl, that was significantly increased by exogenous proline. In the leaves, salt-stress up-regulated ubiquitin, a small protein targeting damaged proteins for degradation via the proteasome, up to 5-fold as detected by western blotting. This change was also affected by proline even in non-stressed leaves. However, salt-stress resulted in a decrease in the amount of ubiquitin-conjugates, particularly in the roots, and this effect was reversed by exogenous proline. Severe salt-stress resulted in an inhibition of the antioxidative enzymes catalase and peroxidase as revealed by spectrophotometric assays and activity gels, but the activity of these enzymes was also maintained significantly higher in the presence of proline. Salt-stress also up-regulated several dehydrin proteins, analysed by western blotting, even in non-stressed plants. It is concluded that proline improves the salt-tolerance of Pancratium maritimum L. by protecting the protein turnover machinery against stress-damage and up-regulating stress protective proteins.

Antioxidants↗
PubMed2000

Left ventricular wall stresses and wall stress-mass-heart rate products in hypertensive patients with electrocardiographic left ventricular hypertrophy: the LIFE study. Losartan Intervention For Endpoint reduction in hypertension.

OBJECTIVE: Left ventricular (LV) hypertrophy on echocardiogram (ECG) strongly predicts coronary heart disease events, but the mechanisms linking increased LV mass to ischemic vascular events is uncertain. DESIGN: Variables related to myocardial oxygen demand were compared among normotensive adults and patients with mild and more severe hypertension, and among groups of moderately hypertensive patients with target organ damage in relation to gender, LV geometry and LV systolic function. SETTING: The Losartan Intervention For Endpoint reduction in hypertension (LIFE) trial, in which hypertensive patients with ECG LV hypertrophy (Cornell voltage-duration product, > 2440 mm x ms and/or SV1 + RV(5-6) > 38 mm) were randomized to > or = 4 years double-blinded treatment with losartan or atenolol. PATIENTS/PARTICIPANTS: A total of 964 LIFE participants enrolled in an echocardiographic substudy, and groups of 282 employed hypertensive and 366 apparently normal adults. INTERVENTIONS: None. MAIN OUTCOME MEASURES: ECG LV parameters contributing to myocardial oxygen demand (wall stresses, LV mass, heart rate and wall stress-mass-heart rate products). RESULTS: In both women and men, stepwise increases from reference subjects to employed hypertensives to LIFE patients were observed for LV wall stresses, mass and stress-mass-heart rate products. LIFE men patients had slightly higher wall stresses and significantly higher triple products than women. Wall stresses were increased in patients with normal LV geometry, eccentric or concentric hypertrophy; triple products were about three and two times normal with eccentric and concentric hypertrophy, with smaller increases in other geometric groups. Patients with decreased LV fractional shortening had two times normal end-systolic stresses and three or four times normal triple products; smaller increases in stresses and triple products occurred with decreased LV midwall function. CONCLUSIONS: Hypertensive patients with ECG LV hypertrophy have increased LV wall stresses and stress-mass-heart rate products, suggesting a contribution of high myocardial oxygen demand to increased risk in such patients. Particularly high stresses and triple products were associated with echocardiographic LV hypertrophy, and subnormal LV chamber and midwall function.

Adult↗
PubMed1996

Comparative diagnostic value of dobutamine stress echocardiography and stress thallium-201 single-photon-emission computed tomography for detecting coronary artery disease in women.

BACKGROUND: The non-invasive diagnosis of coronary artery disease in women remains a difficult clinical problem. The aim of this study was to investigate the comparative diagnostic accuracy of dobutamine stress echocardiography and stress thallium-201 single-photon-emission computed tomography (SPECT) in women who were suspected to have coronary artery disease. METHODS: We studied 70 consecutive women who had not had a previous myocardial infarction (mean age 65 years) who underwent dobutamine stress echocardiography and quantitative coronary angiography. Sixty-one of the 70 women were also subjected to thallium-201 SPECT, with exercise or dipyridamole administration as the stressor, during the same period. A positive diagnosis was based on the detection of inducible wall motion abnormality and the presence of stress-induced abnormalities of perfusion. RESULTS: No significant complication occurred in any patient during dobutamine stress echocardiography (peak dose 31 +/- 9 micrograms/kg per min, atropine administered to 13 patients, peak heart rate 120 +/- 19 beats/min). Coronary artery disease (> or = 50% diameter stenosis) was present in 20 (29%) patients, nine with one-vessel and 11 with multivessel disease. The sensitivity, specificity and diagnostic accuracy of dobutamine stress echocardiography for detecting coronary artery disease were 75, 92 and 87% respectively. In 61 patients who underwent both stress tests, the sensitivity, specificity and accuracy of dobutamine stress echocardiography and stress thallium-201 SPECT were 72 versus 78%, 91 versus 70% (P < 0.05) and 85 versus 72%, respectively. CONCLUSIONS: Dobutamine stress echocardiography appears to be of comparable sensitivity and higher specificity with stress thallium-201 SPECT for noninvasive detection of coronary artery disease in women.

Adult↗
PubMed2004

Palliative care stress in a UK community hospital: evaluation of a stress-reduction programme.

In this study the Nurses Stress Scale and Nurses Coping With Stress Questionnaire were used to investigate work-related stress in 18 nurses providing palliative care in a UK NHS community hospital. These instruments were administered twice before and twice after a stress-reduction programme. In depth qualitative interviews were conducted before and after the programme and a 12-item questionnaire was used to assess whether the nurses found the programme useful. The findings indicated that most nurses did not find their work particularly stressful, and most felt well equipped to cope with palliative care stress. However, the interviews identified a small group of nurses who felt ill equipped to cope and routinely found their work stressful. The principal sources of support for both groups of nurses were family and friends at home rather than colleagues at work, and most felt there was little opportunity to share experiences and feelings with their colleagues. Likewise, few (only 33%) had found an opportunity to practice the relaxation skills they had learnt during the stress-reduction programme. This might explain why there was no evidence of any general improvement in stress and coping scores following the stress-reduction programme. Although the nurses enjoyed the programme and found it helpful, such programmes need to tackle contextual barriers to coping with stress as well as improving the individual coping skills of staff.

Adaptation, Psychological↗
PubMed2003

Bicycle exercise stress in PET for assessment of coronary flow reserve: repeatability and comparison with adenosine stress.

UNLABELLED: PET allows absolute measurements of myocardial blood flow (MBF). The aim of the present study was to evaluate the feasibility and repeatability of supine bicycle exercise stress, compared with standard adenosine stress, in PET. METHODS: In 11 healthy volunteers, MBF was assessed at rest, during adenosine-induced (140 microg/kg/min over 7 min) hyperemia, and immediately after supine bicycle exercise (mean workload, 130 W, which is 70% of the predicted value) using PET and (15)O-H(2)O. The assessment was then repeated after 20 min. Coronary flow reserve (CFR) was calculated as hyperemic/resting MBF for adenosine stress and exercise stress. Repeatability was evaluated according to the method of Bland and Altman. RESULTS: No significant differences were found between the paired resting MBF (1.22 +/- 0.16 vs. 1.26 +/- 0.21 mL/min/g; mean difference, 3% +/- 11%) and the hyperemic MBF with adenosine stress (5.13 +/- 0.74 vs. 4.97 +/- 1.05; mean difference, -4% +/- 14%) or exercise stress (2.35 +/- 0.66 vs. 2.25 +/- 0.61; mean difference, -4% +/- 19%). CFR was reproducible with adenosine stress (4.23 +/- 0.62 vs. 4.05 +/- 1.06, P = not statistically significant; mean difference, -5% +/- 19%) and exercise stress (1.91 +/- 0.46 vs. 1.80 +/- 0.44, P = not statistically significant; mean difference, -5% +/- 15%). Repeatability coefficients for MBF were 0.26 (rest), 1.34 (adenosine stress), and 0.82 (exercise stress) mL/min/g. CONCLUSION: Assessment of CFR with (15)O-H(2)O and PET using bicycle exercise in the PET scanner is feasible and at least as repeatable as using adenosine stress.

Adenosine↗
PubMedDate not supplied

[Stress granules: RNP-containing cytoplasmic bodies springing up under stress. The structure and mechanism of organization].

In this review recent data describing stress granules are summarized. Stress granules are specific RNA-containing structures in the cytoplasm of living cells which arise under stress conditions (e. g. heat shock, UV irradiation, energy depletion and oxidative stress). It became evident that stress granules accumulate non-canonical 48S initiation complexes and contain mRNA with associated proteins, small ribosomal subunits and some initiation factors. Stress granules are depleted with ternary complex and large ribosomal subunit. It's proposed that eIF2alpha phosphorylation and ternary complex decrease can be a trigger for stress granule formation. Shuttling nuclear and cytoplasmic RNA-binding protein TIA-1 plays a crucial role in this process. It's proposed that TIA-1 forms prion-like aggregates, and these aggregates are scaffolds for other components of stress granules. Cytoskeletal structures facilitate the accumulation of stress granule components in local cytoplasmic sites. Investigation of process of stress granule formation is important for understanding of cell reaction to stress and translation regulation mechanisms.

Animals↗
PubMed2006

Effect of Triphala on oxidative stress and on cell-mediated immune response against noise stress in rats.

Stress is one of the basic factors in the etiology of number of diseases. The present study was aimed to investigate the effect of Triphala (Terminalia chebula, Terminalia belerica and Emblica officinalis) on noise-stress induced alterations in the antioxidant status and on the cell-mediated immune response in Wistar strain male albino rats. Noise-stress employed in this study was 100 dB for 4 h/d/15 days and Triphala was used at a dose of 1 g/kg/b.w/48 days. Eight different groups of rats namely, non-immunized: control, Triphala, noise-stress, Triphala with noise-stress, and corresponding immunized groups were used. Sheep red blood cells (5 x 10(9) cells/ml) were used to immunize the animals. Biochemical indicators of oxidative stress namely lipid peroxidation, antioxidants superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), ascorbic acid in plasma and tissues (thymus and spleen) and SOD, GPx and corticosterone level in plasma were estimated. Cell-mediated immune response namely foot pad thickness (FPT) and leukocyte migration inhibition (LMI) test were performed only in immunized groups. Results showed that noise-stress significantly increased the lipid peroxidation and corticosterone level with concomitant depletion of antioxidants in plasma and tissues of both non-immunized and immunized rats. Noise-stress significantly suppressed the cell-mediated immune response by decreased FPT with an enhanced LMI test. The supplementation with Triphala prevents the noise-stress induced changes in the antioxidant as well as cell-mediated immune response in rats. This study concludes that Triphala restores the noise-stress induced changes may be due to its antioxidant properties.

Animals↗