Effect of the lipid peroxide reaction caused by repeated cold stress on cisplatin-induced nephrotoxicity

The peroxide reaction in mouse kidney was examined in order to determine the relationship between the lipid peroxide reaction caused by SART (specific alternation of rhythm in temperature) stress and that caused by drug administration. After exerting SART stress for one wk on 6-wk-old male ddY mice (stress group), the peroxide reaction generated by the administration of a single dose of cis-diamminedichloroplatinum (cisplatin: CDDP, 10 mg/kg, ip) into SART-stressed mice (stress + CDDP group) was compared with the reaction of CDDP-administered nonstressed mice (CDDP group), saline-administered nonstressed mice (saline group), and saline-administered SART-stressed mice (stress + saline group). Lipid peroxidation in the kidneys was significantly higher in the stress group upon cessation of stress exertion than in the normal group. However, no significant difference in the lipid peroxide level after administration of CDDP was observed between the CDDP groups. The renal glutathione levels were significantly different between the CDDP groups and the saline administered groups. These results indicate that the peroxide reaction is generated in the kidneys by stress, but stress has no effect on the peroxide damage caused by CDDP administration. However, the contribution of stress to renal function impairment requires further evaluation.     

Modeling the effects of a bidirectional latent predictor from multivariate questionnaire data

Researchers often measure stress using questionnaire data on the occurrence of potentially stress-inducing life events and the strength of reaction to these events, characterized as negative or positive and assigned an ordinal ranking. In studying the health effects of stress, one needs to obtain measures of an individual's negative and positive stress levels to be used as predictors. Motivated by data of this type, we propose a latent variable model, which is characterized by event-specific negative and positive reaction scores. If the positive reaction score dominates the negative reaction score for an event, then the individual's reported response to that event will be positive, with an ordinal ranking determined by the value of the score. Measures of overall positive and negative stress can be obtained by summing the reactivity scores across the events that occur for an individual. By incorporating these measures as predictors in a regression model and fitting the stress and outcome models jointly using Bayesian methods, inferences can be conducted without the need to assume known weights for the different events. We propose an MCMC algorithm for posterior computation and apply the approach to study the effects of stress on preterm delivery.     

Effect of stressor factors on the behavior of monkeys. III. The behavior of rhesus macaques during immobilization stress

The three-hour immobilizational stress in two groups of males of rhesus monkeys at the age of 7-8 and 10-12 years has been investigated. The reaction on the stress has been established to depend on the age of animals. The young males bear the stress easier, their behaviour after it is practically normal. The normal behaviour of the elder animals restores during 24 hours after immobilization. A comparative analysis of hamadryas baboons and rhesus monkeys behaviour during this type of stress has been carried out. These species differ by their reaction on stress: Papio hamadryas serve as a model of hard depressive stress, the rhesus monkeys--a model of slight-stimulative stress. The peculiarities of stress bearing depend on the selected species, age of the animal, the type of social organization and individual features of behaviour.     

Stress‐Induced Evolutionary Innovation: A Mechanism for the Origin of Cell Types

Understanding the evolutionary role of environmentally induced phenotypic variation (i.e., plasticity) is an important issue in developmental evolution. A major physiological response to environmental change is cellular stress, which is counteracted by generic stress reactions detoxifying the cell. A model, stress‐induced evolutionary innovation (SIEI), whereby ancestral stress reactions and their corresponding pathways can be transformed into novel structural components of body plans, such as new cell types, is described. Previous findings suggest that the cell differentiation cascade of a cell type critical to pregnancy in humans, the decidual stromal cell, evolved from a cellular stress reaction. It is hypothesized that the stress reaction in these cells was elicited ancestrally via inflammation caused by embryo attachment. The present study proposes that SIEI is a distinct form of plasticity‐based evolutionary change leading to the origin of novel structures rather than adaptive transformation of pre‐existing characters.     

The lability of lysosomes during the response of neurons to stress

Synopsis The reactivity of neurolysosomes towards conditions of stress was studied by means of Bitensky's lysosomal permeability test, based on the histochemistry of acid phosphatase. The material used was anterior brain (cortex, Ammon horn, thalamus and hypothalamus) of animals subjected to different forms of stress (physical effort, gravitational acceleration, hyperthermia and emotional stress).The common alterations observed in most neurons were: a reduction in the minimal incubation time required for the histoenzymological reaction for acid phosphatase to become positive; an increase in the number and size of the reaction granules in the perikaryons; the tendency of the granules to conglomerate and their aggregation towards the emergence cone of the nervous processes; the induction of a positive reaction along the neural fibres and their migration towards the synapses and the vascular walls. Intense stress led to an intracytoplasmic diffuse reaction. Very intense stress resulted in a decreased or negative intraneural reaction, consequent to an intrahumoral release of the enzyme.These alterations appear to be due to the increased lability of the neuronal lysosomes, which thus seem to play an important role in the pathogenic mechanism of stress.     

Development of the hormonal reaction to stress in the ontogenesis of the baboon Papio hamadryas

The hormonal reaction of adrenal and gonadal glands of baboons at various ages was studied under 2 hr immobilization stress condition. Concentrations of cortisol, 11-deoxycortisol, 17-hydroxypregnenolone, dehydroepiandrosterone and testosterone were determined by radioimmunoassay in the monkey blood plasma at different times during the stress reaction. A more pronounced reaction of adrenal cortex was shown in 1 year old baboons. The peak of cortisol level in immature monkeys under stress conditions was registered much earlier than in adult monkeys.     

A study of mast cell funcntional activity during immobilization stress

Response of mast cells to stress has a systemic character, being observed in organs both determining development of stress reaction (thymus, bone marrow, adrenals, stomach, duodenum) and not participating in this process (skin, liver). The reaction of mastocytes is manifested as a total degranulation. Mast cell secretion is regulatory by its nature, and biologically active compound are released directly on the target cells. Along with degranulation, which is observed in organs participating in stress reaction formation, migration of mast cells takes place, resulting in their redistribution.     

Individual behavioral and autonomic response to emotional stress in humans

Healthy subjects (n = 53) performed a sound version of the proof-reading test under normal conditions and in the state of emotional stress. Stress resistance was evaluated by the overall number of errors. The propensity to active or passive response to stress was evaluated by the number of "false alarms" and signal omissions. The reaction pattern to emotional stress in stress-resistant subjects, irrespective of their behavioral features, consisted in an increase in sympathetic effects on the cardiac rhythm and a decrease in the reaction time to significant signals. In subjects with low stress resistance, no statistically significant changes in the level of sympathetic tone and reaction time were revealed in the state of stress. Subjects with active behavioral response to stress, irrespective of their level of stress resistance, were characterized by aggressiveness, boldness and independence. Subjects with passive response to stress were inclined to conformism, dependence, and passivity.     

下丘脑-垂体-肾上腺皮质轴应激反应的中枢控制

应激反应是所有生物对紧张性事件的适应性反应,对生物的存活具有十分重要的意义。应激反应的主要特征是下丘脑－垂体－肾上腺皮质（ＨＰＡ）轴激活。ＨＰＨ轴激活的呆区控制十分复杂。海马参与整合感知的信息、解释环境信息的意义及定调行为反应和神经内分泌反应。杏仁核是应激性行为反应以及自主神经和神经内分泌反应的行旅地部位。下丘脑室６ 有直接激活ＨＰＡ轴的作用。负反馈机制、下丘脑局部回路和细胞因子也可能参与了调节Ｈ     

Evidence for the Contribution of the Mehler-Peroxidase Reaction in Dissipating Excess Electrons in Drought-Stressed Wheat

Gross O2 evolution and uptake by attached, drought-stressed leaves of wheat (Triticum aestivum) were measured using a 16O2/ 18O2 isotope technique and mass spectrometry. The activity of photosystem II, determined from the rate of 16O2 evolution, is only slightly affected under drought conditions. During drought stress, net CO2 uptake decreases due to stomatal closure, whereas the uptake of 18O2 is stimulated. The main O2-consuming reactions in the light are the Mehler-peroxidase (MP) reaction and the photorespiratory pathway. From measurements of the rate of carbon flux through the photorespiratory pathway, estimated by the analysis of the specific radioactivities of glycolate, we conclude that the rate of photorespiration is decreased with drought stress. Therefore, the O2 taken up in the light appears to be preferentially used by the MP reaction. In stressed leaves, 29.1% of the photosynthetic electrons are consumed in the MP reaction and 18.4% drive the photorespiratory pathway. Thus, overreduction of the electron transport chain is avoided preferably by the MP reaction when drought stress restricts CO2 reduction.     

Tyrosine Decarboxylase and Dopa Decarboxylase in Drosophila virilis Under Normal Conditions and Heat Stress: Genetic and Physiological Aspects

The activity of tyrosine decarboxylase (TDC) and dopa decarboxylase (DDC) was studied in adults of two lines of Drosophila virilis,contrasting in their reaction to stress conditions. Differences were found in the activity of both enzymes between individuals of the examined lines. Genetic analysis of these differences was made. Each of the two enzymes was found to be controlled by a single gene or, possibly, by a block of closely linked genes. The gene responsible for TDC activity is located on one of the autosomes (excluding chromosome II). DDC activity in D. virilisis regulated by a gene located, apparently, on chromosome II. Adults of the line responding to stress by a stress reaction (r-line) were shown to react to a short-term heat stress (38°C, 60 min) by a decrease in TDC activity. TDC activity in flies of the line incapable of the stress reaction (nr-line) did not alter in such conditions. DDC activity of adults of both lines was found to be unchangeable under stress conditions.     

蚕豆叶片几丁质酶活性的蚜虫诱导──植物生理应激反应的趋同性

在蚜虫和蚕豆构成的种群作用系统中,证实蚜虫的取食危害能诱导植物几丁质酶活性的增加,并且诱导反应的强度与昆虫危害程度相关．实验结果表明,诱导效应能在植物体内传导,诱导反应随时间呈动态变化．综合目前几丁质酶的诱导研究,认为几丁质酶不是特异性的抗性蛋白,而是应激反应的伴随产物,并提出在逆境条件下植物的应激反应模式．     

Individual propensity to active or passive behavior during exposure to emotional stress in individuals with various blood cortisol levels

Effects of baseline and reactive blood cortisol on operator's performance were studied in subjects with active of passive behavioral reactions under exposure to stress. The type of behavioral reaction to stress (shift in the rates of omissions or false alarms) was found to be associated with the baseline blood cortisol and its levels averaged in the course of the experiment. Subjects with active reaction (stress produces an increase in the rate of errors of the false-alarm type) were characterized by the low cortisol level, whereas its high level was observed in subjects with passive reaction (stress produces an increase in the rate of errors of the omission type). Individuals with high baseline cortisol level and those with the passive reaction to stress exhibited enhanced cardiovascular reactivity during performance in normal conditions and its reduction during the performance under exposure to stress.     

The abiotic stress as a factor responsible for gypsy moth outbreaks

The close quantitative interrelation between the reaction of birch to abiotic stress (spring–summer droughts) (the degree to which the yearly radial increment of trees decreases) and entomoresistance has been established. Tree stands that were heavily defoliated by gypsy moth showed a much stronger reaction to the droughts which preceded the outbreaks by the decrease in their radial increment than those weakly defoliated by this phytophagous insect. The reaction of trees to the abiotic stress is regarded as the key factor that controls the drop in their entomoresistance during outbreaks of gypsy moth in woods damaged by anthropogenic effects.     

Do oxidative stress conditions impairing photosynthesis in the light manifest as photoinhibition?

We compared the effect of photoinhibition by excess photosynthetically active radiation (PAR), UV-B irradiation combined with PAR, low temperature stress and paraquat treatment on photosystem (PS) II. Although the experimental conditions ensured that the four studied stress conditions resulted in approximately the same extent of PS II inactivation, they clearly followed different molecular mechanisms. Our results show that singlet oxygen production in inactivated PS II reaction centres is a unique characteristic of photoinhibition by excess PAR. Neither the accumulation of inactive PS II reaction centres (as in UV-B or chilling stress), nor photo-oxidative damage of PS II (as in paraquat stress) is able to produce the special oxidizing conditions characteristic of acceptor-side-induced photoinhibition.     

Genotypic differences in the reactivity of the hypophyseo-adrenal system and the resistance of mice to cooling

The response of pituitary-adrenal axis (non-specific stress reaction) and body temperature change (specific reaction to cold) to mild and extreme cold was studied in ten mice strains. Genotypic systems controlling the activity of pituitary-adrenal axis under the cold of various intensity seem to be different. It is possible that the extent of decrease in body temperature under the cold of various intensity is determined by the same hereditary mechanisms. It was shown that the considerable phenotypic variability in response of pituitary-adrenal axis and body temperature depends on environmental conditions as well, i.e. on the intensity and duration of cold stress. Significant variability in the survival under cold conditions in different mice strains and the important role of specific reaction to forecast of resistance to cold were discussed.     

Effect of stress on the cardiovascular system activity in operators of predominantly mental work at different times of the day and the working week

The heart rate and systolic and diastolic blood pressures (HR, BP_s, and BP_d, respectively) were measured in controllers of electricity distribution at the beginning and end of 12-h shifts. Hemodynamic parameters were calculated. The stress was assessed with a five-point scale. It was found that the stress of mental work of the operator type activated the functioning of the cardiovascular system (CVS). The CVS reaction was more pronounced and interactive during the first shifts in each block than during the second shifts. The CVS reaction was more pronounced and interactive during day shifts than during night shifts. An increase in stress during the first day shifts was accompanied by a decrease in HR and an increase in minimum BP_d during the shift, in the absence of a BP_s reaction. The minimum levels of all three parameters (HR, BP_s, and BP_d) were increased during the first night shifts, which indicates that the effectiveness of CVS activation in the nighttime was decreased as compared to the daytime. The BP_d is specifically sensitive to the work stress of controllers: its reaction to an increase in stress is classic during the first shifts and inverted during the second night shifts. This reflects exhaustion of adaptation reserves. The HR showed attenuated reactivity during the daytime, but not during the nighttime, when it reacted in the classic way.     

高尔基体应激信号传导通路研究进展

高尔基体应激是因脑缺血再灌注等应激反应中,导致高尔基体蛋白质加工运输、分泌等功能改变,与多种细胞内的信号通路是密切相关的。我们综观近年相关文献,并综述其研究进展,结果认为高尔基体应激通过磷酸肌醇、蛋白激酶C/蛋白激酶D、RAS/MAPK激酶、c AMP/PKA等信号通路发挥作用,参与缺血性脑卒中、脊髓损伤及神经变性疾病等发病机制。