[Emotional stress as a clinical model to study the pathogenesis of the initial phase of the general adaptation syndrome]

INTRODUCTION

General adaptation syndrome (GAS), the basis of the development of which is stress phenomenon, is an essential component of the pathogenesis of many diseases and syndromes. However, the patho genesis of GAS hitherto is considered exclusively from the endocrinological viewpoint. This relates primarily to the initial phase of the GAS, a clinical model for the study of which may be psycho-emotional stress (PES), which we studied using three groups of volunteers.

METHODS

The first one consists of 25 students who were waiting for unaccustomed physical activity (17 men) and play debut on the stage (8 women). The second group consists of 48 children (2-14 years) who expected for "planned" surgery. The third group of volunteers is made up of 80 students (41 women and 39 men) during the first exam. The concentration of cortisol, endotoxin (ET), the activity of antiendotoxin immunity (AEI) and the haemostatic system parameters were determined in the blood serum of volunteers in various combinations.

RESULTS

We found laboratory evidence for PES at 92% of students of the first group, 58% of children of the second one and in 21% of students of the third group of volunteers (mostly women). The concentration of ET increased at 13 (52%) volunteers of the first group with a significant increase of average indicators in the whole group (from 0.84 ± 0.06 to 1.19 ± 0.04 EU/ml). At children of the second group, the average concentration of ET increased even more significantly (from 0.42 ± 0.02 to 1.63 ± 0.11 EU/ml), which was accompanied by the activation of the hemostasis system. A degree of the activation was directly dependent on the level of ET in the general circulation and on an activity of AEI. Examination stress in the third group of volunteers is accompanied by activation of plasma hemostasis (increased initial thrombosis rate and reduced the time it starts, lag-period) in 26% of female students and 15% of male students.

CONCLUSION

We suggest that it is possible to use the PES as a clinical model for studying the initial phase of the GAS, examine the role of excess of intestinal ET in the general blood circulation (endotoxin aggression) in the induction of systemic inflammation, which is very likely participated in the initiation of the GAS.

Stress reactivity and corticolimbic response to emotional faces in adolescents

OBJECTIVE

Adolescence is a critical period in the development of lifelong patterns of responding to stress. Understanding underpinnings of variations in stress reactivity in adolescents is important, as adolescents with altered stress reactivity are vulnerable to negative risk-taking behaviors including substance use, and have increased lifelong risk for psychopathology. Although both endocrinological and corticolimbic neural system mechanisms are implicated in the development of stress reactivity patterns, the roles of these systems and interactions between the systems in reactivity to social stimuli in adolescents are not clear. We investigated the relationship between cortisol response to a laboratory-based social stressor and regional brain responses to emotional face stimuli in adolescents.

METHOD

Changes in cortisol levels following the Trier Social Stress Test-Child version (TSST-C) were measured in 23 disadvantaged and chronically stressed adolescents who also participated in functional magnetic resonance imaging during processing of emotional faces and structural magnetic resonance imaging. The relationships between changes in cortisol following the TSST-C with regional brain activation during face processing, as well as with regional brain morphology, were assessed.

RESULTS

Cortisol change on the TSST-C showed a significant inverse relationship with left hippocampus response to fearful faces (p < .05, corrected); significant associations with volume were not observed.

CONCLUSIONS

Increased cortisol response to the Trier social stressor was associated with diminished response of the left hippocampus to faces depicting fear. This suggests that HPA-corticolimbic system mechanisms may underlie vulnerability to maladaptive responses to stress in adolescents that may contribute to development of stress-related disorders.

[Neurobiological consequences of child sexual abuse: a systematic review]

OBJECTIVE

The results of several studies suggest that there is a critical timeframe during development in which experiences of maltreatment and sexual abuse may lead to permanent or long-lasting neurobiological changes that particularly affect the hypothalamus-pituitary-adrenal axis response. The aim of the present study was to provide an updated review on the main neurobiological consequences of child sexual abuse.

METHODS

We selected articles published between January 1999 and January 2010 in English or Spanish that focused on the neurobiological consequences of child sexual abuse available through Medline, Scopus and Web of Science. We also examined the references in published articles on the consequences of sexual victimization in childhood.

RESULTS

In this review we included 34 studies on neurobiological consequences, indicating different kinds of effects, namely: neuroendocrine, structural, functional and neuropsychological consequences, which affect a large number of victims.

CONCLUSIONS

The existing body of work on the neurobiological consequences of maltreatment shows the need to consider maltreatment and child sexual abuse as health problems that affect different areas of victims' lives, which would in turn favor the development of intervention and treatment programs that take these multiple effects into account.

[Immunity and health: the accelerated aging of immune system in veterans of extra risk divisions]

This article presents the data about state of health and immunity in veterans of extra risk divisions. The increased morbidity and immunity infringement in the remote terms after nuclear tests, and also while liquidation of consequences of radiating failures on nuclear submarines are shown. Changes of humoral factors of nonspecific protection, concentration of immunoglobulinums, in blood whey, a sensitization of lymphocytes to respiratory viruses, humoral and cellular autoimmune shifts are registered. Some of the revealed changes (complement, lysozyme, concentration of immunoglobulinums) are a consequence of advanced age and accompanying diseases in the people surveyed, and others (autoimmune shifts, a sensitization to respiratory viruses) can be connected with carrying out of tests of the nuclear weapon. Some of immunological changes are apparently a consequence of joined actions of radiating and not radiating factors. Among the last ones stress plays the essential role. For the characteristic of a state of health in 20-40 years after carrying out nuclear tests and possible radiating influence the estimation of autoimmune changes has a great value. The important role of such changes in morbidity of veterans of extra risk divisions is shown.

[Effects of phenibut on parameters of cerebral hemodynamics in swimmers with dysadaptation syndrome and various types of systemic hemodynamics]

Administration of phenibut (0.25 g) during 4 weeks as a means of rehabilitation promoted optimization of the biochemical status and cerebral blood circulation in swimmers with various types of systemic hemodynamics, which were examined 20 minutes after warm-up.

[Stress and stress hormones in mammals]

Stress and influence of stress hormones on organisms is interesting theme in many fields of study, e.g. human and veterinary medicine, zoology, ecology. Short time stress is not negative reaction, because it helps to alive. In stress response increase stress hormones levels (catecholamines, glucocorticoids), which cause elevated heart rate, blood pressure and acute elevation of blood glucose. These reactions cause better blood flow and acute utilization energy in vital organs, e.g. the brain, heart or muscles, and its cause better survive of organism. On the other hand, prolonged stress response is dangerous, e.g. chronically elevated blood pressure or levels blood glucose, sexual disorders, etc. If we know, which factor acts as stressor, we can eliminate or minimized its incidence. In case of transport its better to prefer the shortest way or better weather conditions. It's possible to improve welfare of animals in captivity, e.g. enrichment housing, physical conditions (temperature, humidity, light cycles, etc.), social structure in social animals.

[Effect of adrenocorticotropic hormone (ACTH4-10) on information network of the cardiovascular systems]

The polyparametric description of adaptation syndromes in students using a uniform set of parameters of cardiovascular system and their relationships is presented. An analog of adrenocorticotropic hormone (ACTH4-10) is shown to exert varying effects on the development of different adaptation syndromes. Adaptation syndromes characterized by moderately active physiological processes (as judged by EGG, rheovasogram, respiration rate) and lowered vascular tonus were associated with marked improvement of the health status.

[Application of balneotherapeutic factors in the system of rehabilitative treatment of children with environmental dysadaptation syndrome]

Combined balneotherapy including intake and external application of Zheleznovodsk-type mineral water was given to 60 children at the age from 7 to 14 years presenting with environmental dysadaptation syndrome. This treatment ensured favourable dynamics of clinical signs of asthenovegetative, dyspeptic, and pain syndromes. Moreover, it exerted beneficial influence on the mechanisms of vegetative regulation, improved the psychoemotional status of the patients and functional capacity of their immune system.

Neurosteroids in the context of stress: implications for depressive disorders

Animal models indicate that the neuroactive steroids 3alpha,5alpha-THP (allopregnanolone) and 3alpha,5alpha-THDOC (allotetrahydroDOC) are stress responsive, serving as homeostatic mechanisms in restoring normal GABAergic and hypothalamic-pituitary-adrenal (HPA) function following stress. While neurosteroid increases to stress are adaptive in the short term, animal models of chronic stress and depression find lower brain and plasma neurosteroid concentrations and alterations in neurosteroid responses to acute stressors. It has been suggested that disruption in this homeostatic mechanism may play a pathogenic role in some psychiatric disorders related to stress. In humans, neurosteroid depletion is consistently documented in patients with current depression and may reflect their greater chronic stress. Women with the depressive disorder, premenstrual dysphoric disorder (PMDD), have greater daily stress and a greater rate of traumatic stress. While results on baseline concentrations of neuroactive steroids in PMDD are mixed, PMDD women have diminished functional sensitivity of GABA(A) receptors and our laboratory has found blunted allopregnanolone responses to mental stress relative to non-PMDD controls. Similarly, euthymic women with histories of clinical depression, which may represent a large proportion of PMDD women, show more severe dysphoric mood symptoms and blunted allopregnanolone responses to stress versus never-depressed women. It is suggested that failure to mount an appropriate allopregnanolone response to stress may reflect the price of repeated biological adaptations to the increased life stress that is well documented in depressive disorders and altered allopregnanolone stress responsivity may also contribute to the dysregulation seen in HPA axis function in depression.

Roadblock to recovery: the surgical stress response

Inadequately managed post-operative pain and the resulting surgical stress response (SSR) negatively affect patient outcomes. Critical care nurses need to understand that adequate pain management is critical to enabling patient recovery. A review of the physiology and pathophysiology of the SSR provides concrete evidence to substantiate the need for critical care nurses to prioritize nursing care that focuses on the prevention, early detection, and management of pain and the surgical stress response. Critical care nurses equipped with this evidence are capable of improving patient outcomes.

[The influence of stress factors on the activities of operating staff of law-enforcement bodies]

The work is devoted to the problem concerning psychiatrists, psychophysiologists and medical psychologists who render assistance to the specialists dealing with extreme activities. The study of response of law-enforcement bodies' employees on operative work stressors, comparison of stress factors influencing on them, the ways to control the stress and manifestations of psychical dysadaptation with peculiarities of professional stress in servicemen are of great interest. The authors present the detailed analysis of investigations devoted to the general idea of psychical stress and private problems connected with stress development in employees of law-enforcement bodies dealing with operative work. The revealed stress factors and typical coping-mechanisms taking part in adapting responses are discussed. The typical signs of disorders in psychical adaptation including the individual changes are shown.

[Psychological stress in oncology: the role of glucocorticoids]

During the last years, the correlations between biological processes, psychological adjustment and stress disorders have received increasing attention and a growing body of research results has been published in the general literature. In the realm of psycho-oncology, however, conceptual models on this topic and studies aimed at their validation have remained relatively scanty. On the basis of our observations and available literature in the field of post-traumatic and depressive stress disorders in oncology, we have proposed to apply the concept of allostatic load to the study and understanding of the psychological experience of cancer. This strategy has led us to the formulation of a novel classification of adjustment disorders in oncology and the creation of the clinical entity named "cancer-specific stress syndrome". Depending on clinical presentation of the syndrome, one distinguishes three subtypes, namely the depressive, post-traumatic and "dysallostatic" (mixed) forms. In the present paper, we examine the role of glucocorticoids and their relationships with one of the basic components of allostatic load--a failure to counter-regulate the immune system by the hypothalamic-pituitary-adrenal axis--in the physiopathology of stress disorders in oncology. Conflicting theories are presented--glucocorticoid cascade versus insufficient glucocorticoid signal transmission--and studies measuring potential correlations between stress and cortisol in oncology are critically reviewed. The results of this process provide substantial support for the application of the allostatic load model and post-traumatic phenomenology, but important advances have yet to be achieved before definitive conclusions can be established in this field. Such advances could lead to profound changes in the way we understand and treat psychological distress in patients with cancer, both pharmacologically and psychotherapeutically.

Stress, stress response, and health

Components of stress and the stress response differ between men and women. The tend-and-befriend response, mediated by oxytocin and endogenous opioids, may be more applicable to women than the fight-or-flight response, which was based largely on studies of men. Even within the flight-or-flight response pattern there are sex-based differences. The HPA axis interacts with reproductive function, such as menstruation. For immune function there are sex differences as well as differences within the menstrual phase. Inclusion of men and women in stress response studies is critical. Further study is needed to clarify the influence of ovarian hormones on the stress and immune responses during the reproductive stages in women's lives, including menarche. pregnancy, and perimenopause.

The deprivation syndrome is the driving force of phylogeny, ontogeny and oncogeny

Energy is the motor of life. Energy ensures the organism's survival and competitive advantage for reproductive success. For almost 3 billion years, unicellular organisms were the only life form on earth. Competition for limited energy resources and raw materials exerted an incessant selective pressure on organisms. In the adverse environment and due to their 'feast and famine' life style, hardiness to a variety of stressors, particularly to nutrient deprivation, was the selection principle. Both resistance and mutagenic adaptation to stressors were established as survival strategies by means of context-specific processes creating stability or variability of DNA sequence. The conservation of transduction pathways and functional homology of effector molecules clearly bear witness that the principles of life established during prokaryotic and eukaryotic unicellular evolution, although later diversified, have been unshakably cast to persist during metazoan phylogenesis. A wealth of evidence suggests that unicellular organisms evolved the phenomena of differentiation and apoptosis, sexual reproduction, and even aging, as responses to environmental challenges. These evolutionary accomplishments were elaborated from the dichotomous resistance/mutagenesis response and sophisticated the capacity of cells to tune their genetic information to changing environmental conditions. Notably, the social deprivation responses, differentiation and apoptosis, evolved as intercellularly coordinated events: a multitude of differentiation processes were elaborated from sporulation, the prototypic stress resistance response, while apoptosis, contrary to current concepts, is no altruistic cell suicide but was programmed as a mutagenic survival response; this response, however, is socially thwarted leading into mutagenic error catastrophe. In the hybrid differentiation-apoptosis process, cytocide and cannibalism of apoptotic cells thus serve the purpose of fueling the survival of the selfish genes in the differentiating cells. However, successful mutagenesis, although repressed, persisted in the asocial stress response of carcinogenesis as a regression to primitive unicellular behavior following failure of intercellular communication. While somatic mutagenesis was largely prevented, Metazoa elaborated germ cell mutagenesis as an evolutionary vehicle. Genetic competence, a primitive, stress-induced mating behavior, evolved into sexual reproduction which harnessed mutagenesis by subjecting highly mutable germ cells to a rigid viability selection. These processes were programmatically fixed as life- and cell-cycle events but retained their deprivation response phenotypes. Thus, the differentiation-apoptosis tandem evolved as the 'clay' to mold the specialized structures and functions of a multicellular organism while sexual reproduction elaborated the principle of quality-checked mutagenesis to create the immense diversity of Metazoa following the Cambrian explosion. Throughout these events, reactive oxygen and nitrogen species, which are regulated by energy homeostasis, shape the genetic information in a regulated but random, uncoded process providing the fitness-related feedback of phenotype to genotype. The interplay of genes and environment establishes a dynamic stimulus-response feedback cycle which, in animate nature, may be the organizing principle to contrive the reciprocal duality of energy and matter.

[Ongoing conflict situations and physical disease]

In most cases psychosomatic patients are not vitally threatened. Nevertheless almost half of the emergency patients have got psychical disturbances (e.g. neurotic heart disease, states of hyperventilation or vertigo). A reason is not only the personal development of early childhood. More often the problems are to be found within strained relations. The physical illness can be conceived as an (unconscious) attempt to master a conflict or loss, as narcissistic reparation, as adaption-effort or even as self destruction Selye's theory of stress presents the linkage between the organ pathology and the influence of the psychosocial situation. Examples of medical cases explain these correlations.

Brain norepinephrine changes with simulated weightlessness and relation to exercise training

Maintenance of nervous system function during periods of a deconditioning syndrome is important to prevent diminished psychological/behavioral, and physiological function observed during periods of bed rest, physical inactivity, and weightlessness. A main neurotransmitter is norepinephrine (NE), and its regulation yields insight into nervous system function. This research tested the hypotheses that, 1) deconditioning syndrome induced by simulated weightlessness of 9 days via the head-down tilt (HDT) model results in a blunted noradrenergic turnover rate in selected brain tissue and, 2) that exercise training acts as a countermeasure for these changes in noradrenergic activity. Male Sprague-Dawley rats (3 months, n = 60) were divided into either a HDT (HDT, n = 20), cage control (CAGE-CN, n = 20) or an exercise trained HDT (HDT-EX, n = 20) group. Each group was further subdivided into a saline (n = 10) or alpha-methyl-tyrosine (AM, n = 10) (200 mg/kg) injected subgroup. Animals in the HDT groups were tail suspended in a 30 degrees head-down tilt position for 9 days. Norepinephrine turnover was determined 3 h following administration of saline or alpha-methyl-para-tyrosine. The NE turnover rate (ng gm(-1) x h(-1)) for the CN, HDT, and HDT-EX groups, respectively, were as follows: locus coeruleus, 63 +/- 33, *134 +/- 65, 85 +/- 61; hypothalamus, 195 +/- 50, *47 +/- 47; *93 +/- 34; cerebellum, 10 +/- 18, *65 +/- 15, *53 +/- 19; cerebral cortex, 6 +/- 20, *28 +/- 15, *68 +/- 22. (*Denotes significant difference from the control group at the p < or = 0.05 level of significance; +denotes significant difference from the HDT group at the p < or = 0.05 level of significance.) These findings suggest that: 1) norepinephrine turnover rate adapts in a tissue-specific manner following a 9-day tail suspension, 2) increased norepinephrine turnover rates and norepinephrine tissue content in the HDT group are consistent with neural adaptation to a chronic stress response.

[The significance of physical activity on the physiological stress reaction]

The extent of physical activity and the dynamic performance capacity show an inverse relationship to cardiovascular mortality, independent of the influence of other risk factors, but the underlying mechanism remains uncertain. Most concepts assume that the aerobic capacity of the peripheral musculature is increased by training, and thus improved cardiocirculatory regulation and especially a more favorable stress reaction pattern are attained. This adaptation is essentially an inverse adaptation mechanism as in established cardiocirculatory insufficiency. Based on an extended stress concept, it can be seen that training effects, especially in autonomic circulatory regulation, occur under physiological conditions to a lower degree in the renin-angiotensin-aldosterone system and in inflammatory reaction. The training effects depend on the form of exercise, the baseline condition, the extent of training, and genetic predisposition. It can be particularly demonstrated when the aerobic capacity has been sufficiently enlarged in an adequate proportion of the peripheral musculature. To what extent and under what conditions these training effects can be used under the pathophysiological conditions of established cardiocirculatory insufficiency is presently under investigation.

Physiological consequences of everyday psychosocial stress

A large body of data has been accumulated concerning physiological responses in people exposed to stressors in laboratories. Adrenaline and cortisol have become known as "stress hormones" because, in men, levels of both hormones consistently rise in response to stress in laboratory-based investigations. If chronically repeated, elevation of adrenaline and cortisol is likely to have long-term consequences for health, especially cardiovascular health, partly via the effects of the hormones on blood pressure and serum cholesterol levels. Research on people conducting their everyday lives is necessary to establish whether the same responses are shown on a day to day basis. Such research requires new methodologies and careful data collection. So far, it has been shown that adrenaline and blood pressure do seem to vary in expected ways. Other responses in everyday life, including those of cholesterol, cortisol and the immune system, are less well characterised.

[Stress]

The general adaptation syndrome is discussed on the light of recent discoveries on hypothalamic peptides and of their possible influence in survival and in induction of diseases. The problem of stress in alcoholism is reviewed. The author ends with a short souvenir of Hans Selye.

Short- and long-term association between uric acid and a natural disaster

OBJECTIVE

This paper analyzes the longitudinal relationship between serum uric acid level and a natural disaster.

METHODS

The sample consists of factory workers who were participating in a longitudinal epidemiological study of coronary heart disease risk factors. Participants were seen in 1975 (baseline), 1980 (5 year follow-up), and 1987 (12 year follow-up). The 5 year (1980) follow-up examination was interrupted by a major earthquake and resumed 2 weeks after the quake. At this examination, participants seen after the quake had, on the average, significantly lower serum uric acid than those seen before the earthquake. In 1987 (7 years after the quake), participants were questioned whether or not (in their own perception) they were still suffering from damages due to the 1980 earthquake.

RESULTS

At the examination in 1987, participants who reported suffering from damage due to the 1980 quake showed on the average significantly increased serum uric acid compared with participants who reported not suffering from damages due to the 1980 quake. The analyses of the data of 578 individuals who participated in all three examinations confirmed these findings and showed that they were independent from levels of uric acid measured prior to the disaster.

CONCLUSIONS

The reason for this apparent different association with uric acid and acute and long-term exposure to the quake remains to be clarified but these findings are consistent with the existence of diverse patterns of physiologic response to different stressors.

Vestibular function and sensory interaction in altered gravity

The effects of weightlessness on vestibular function have been studied since the beginning of manned spaceflight. The results of these studies have been highly variable and to some extent even contradictory, which makes it difficult to draw unambiguous conclusions. This variability is probably due to at least three factors: (1) individual differences in the adaptive process, (2) non-standardized experimental methods and conditions, (3) a lack of integrated experiments. For this reason, we have used a single integrated approach with a specially developed battery of tests. The results thus obtained for 21 cosmonauts on short- and long-term flights are reviewed here, and discussed in the light of the results obtained by others. Changes in the operation of the vestibular system and in all functions based on vestibular afferent input are commonly observed in spaceflight. These changes are characteristic for the process of adaptation and re-adaptation to altered gravity. They occur in a high proportion of persons exposed to such conditions, although there are individual differences with regard to severity, nature, time and duration of occurrence, and the dynamics of the process. Analysis of the observations in a large number of cosmonauts has permitted to distinguish three types of adaptation of the system to altered gravity. The first type of adaptation is characterized by a strong response to any stimulus during the initial adaptation period. The second type of adaptation is characterized by responses that are drastically decreased or even absent. The third type of adaptation is distinguished by the selective response of the sensory system to certain types of stimulation only. After long-term missions the process of re-adaptation usually takes a more severe course than the earlier process of adaptation to microgravity. Both adaptation and re-adaptation follow an undulating course, in which adaptation and re-adaptation are alternating. This is most conspicuous during long-term flights, and it suggests that in the initial stage of adaptation to weightlessness the vestibular input plays a dominant role, while at the end of the adaptation process the visual input prevails.

The central adaptation syndrome: psychosocial stress as a trigger for adaptive modifications of brain structure and brain function

This review makes an attempt to combine data from biological and psychosocial stress literature and to suggest an alternative interpretation of the relationship between stress and disease. It rearranges the presently available knowledge on the short- and long-term effects of stress on many different aspects of brain structure and brain function in the form of a new conceptualization of the biological role of the stress response. The higher associative brain structures are not only the sites in which environmental and psychosocial demands are recognized and from which a less or more systemic, i.e. controllable or uncontrollable, stress response is initiated. They are also the sites which are primarily affected in the course of the stress response: the stress response acts as a trigger for the adaptive modification of the structure and the function of the brain of higher vertebrates and serves thus to adjust, in a self-optimizing manner, the behavior of an individual to the ever-changing requirements of its external world. This novel concept summarizes a large amount of information into a framework that lends itself to testable strategies for future research.

Explaining fatigue in congestive heart failure

Fatigue is a prominent symptom in patients with chronic heart failure, limiting physical activity and impairing quality of life. Although the underlying mechanisms are not clearly identified, alterations associated with peripheral adaptation in heart failure appear to play an important role, including a variably impaired peripheral perfusion during exercise, reduced oxidative capacity of skeletal muscle, impaired muscle strength, and possibly reflex mechanisms associated with alterations in the metabolism of skeletal muscle. Exercise training can, in part, reverse these peripheral alterations, improve exercise capacity, and alleviate fatigue.

The stress response in critical illness

Under normal, unstressed conditions, the body maintains a dynamic equilibrium known as homeostasis--a complex interplay balancing the conflicting demands presented by many internal and external forces. In the face of threatened or actual disruptions (i.e., stress), molecular, cellular, physiologic, and behavioral responses act to restore homeostasis. These responses can be specific to a particular stressor and relatively circumscribed (e.g., secretion of insulin in response to an increase in blood glucose), or can be generalized and relatively nonspecific (e.g., behavioral manifestations of severe anxiety). Typically, more nonspecific and generalized responses occur in the setting of severe and threatening disruptions in homeostasis, and taken together, these responses are known as the "general adaptation or stress syndrome". We will describe the elements and organization of the generalized stress response with particular attention to the hypothalamic-pituitary-adrenal axis as it interacts with the immune system, and we will review what is known about this interactive network in the setting of critical illness.

Stress-induced arrhythmic disease of the heart--Part I

This review deals with the following principal concepts: (1) Heart injuries in single severe stress episodes manifested primarily in disturbances of membrane lipid bilayer, sarcolemmal Na, K-pump, and sarcoplasmic Ca-pump with concurrent limited disturbances of the heart energy supply, namely, of the creatine kinase and glycolysis systems. These disturbances cause small focal myocardial lesions and reduce cardiac electrical stability: the fibrillation threshold falls and ectopic activity increases. In repeated stress, this damage, localized mainly in the richly innervated conduction system, accumulates to cause even more pronounced disturbances of electrical stability and severe arrhythmias. (2) Severe stress and beta-adrenergic effects on the heart regularly result in coronary vasodilation and increased coronary blood flow. However, the entire primary complex of stress-induced injuries and disturbances of the heart's electrical stability occurs despite the increased coronary blood flow. Thus, beta-adrenergic stress-induced injuries may indeed develop as primary stress damage to cardiomyocytes without any relation to ischemia. (3) The main factor determining high vulnerability or, on the contrary, resistance of the heart to stress is the state of stress-limiting systems, namely, the opioidergic, GABAergic, cholinergic, adenosinergic, and other systems. Activation of these systems by adaptation to repeated stress or other factors prevents serious injuries to the heart in severe stress. Conversely, genetically determined or acquired dysfunction of these systems predisposes to severe arrhythmias and sudden death. Thus, in stress-induced arrhythmic disease as well as in ischemic heart disease, the main pathogenetic links are outside the heart, but they differ from those observed in ischemia. (4) The clinical picture of stress-induced arrhythmic disease, that is, alterations in electrocardiogram, coronarogram, and patient responses to stress, physical loads, and tranquilizers differ, as do pathologic alterations in the heart. These differences are summarized at the end of this review.

Changes in blood glucose induced by upper GI diagnostic endoscopy: the influence of various premedications

In this study we measured the blood glucose before and after diagnostic upper GI endoscopy as an index of the stress induced by the procedure. The possible influence of various premedications in the blood glucose was also studied. One hundred and twenty consecutive non-diabetic patients of both sexes aged 20-75 years were randomly allocated into four groups (A,B,C,D) according to the premedication used. Sixty non-diabetic patients, who were not endoscoped, were allocated into three groups (C1, C2, C3) and served as controls. Blood glucose increased significantly in the patients but not in the controls. No correlation was found between the changes in the blood glucose and the time needed for the endoscopy. Changes in the blood glucose did not differ among the patients (F = 0.214; p = 0.886) irrespective of the premedication; however the increase was numerically less when 10% lidocaine spray was used as a premedication (Groups A and C). It is concluded that diagnostic upper GI endoscopy induced a significant increase in blood glucose, irrespective of the premedication. This increase seemed to be mainly the result of the stress induced by the irritation of the pharynx during the intubation.

The stress response and autoimmunoregulation

Using the recent burgeoning of information on how the stress response systems interact, and combining this with advances in our understanding of neuroimmune communication, a proposed neuroendocrine-neuroimmune stress response system incorporating autoimmunoregulation is reviewed. The study of immunocyte behavior in certain clinical conditions associated with a variant stress response may help illuminate the functioning of the neuroendocrine-neuroimmune stress response system.

[Elements of the theory of the extreme body state]

A concept of extreme state as a specific physiological category different from the general adaptation syndrome (stress-response), is presented. The extreme state occurs in case of a functional supertask when the price of urgent adaptation of the organism can involve life-threatening. The author presents a bio-economic approach to analysis of redistribution of the energy balance for maintenance of the organism's functioning in a critical situation, and suggests some ways of scientific-practical realisation of this approach.

[Stress]

Any change in the social or physical environment that threatens the needs or interests of a mammal, induces a state of tension ('stress') in the animal. Driven by this tension, the animal changes its behaviour. At the same time, alterations occur in bodily functions. All organs and regulatory systems (central and peripheral nervous systems, endocrine and immune systems) participate in these behaviour-physiological response and are affected in their activities. The character of the reactions (e.g. fight, flight, passivity) is mainly determined by the animals appraisal of the environmental change and of the possible impact of its response. Aim of the reactions is neutralising the threat and gaining control over the environment (adaptation). When this is achieved, the tension recedes. In case the response is unsuccessful, the state of tension persists ('chronic stress'). Prolonged exposure of brain and/or bodily functions to stress can result in pathological states.

[The dependence of the formation of stress stomach ulcers on the function of the hypothalamo-hypophyseal-adrenal cortical system]

The effect of supraphysiological doses of corticosteroids on mucosal ulceration of stomach was studied in rats. Cortisol (30 mg/100 g) blocked the PACS. During the PACS block, ulcerogenic properties of stressor increased. This effect was reduced by subsequent corticosterone replacement therapy. The new concept of supraphysiological doses of corticosteroids effect is discussed. The stomach ulceration seems to result from the corticosteroid insufficiency.

[The current concepts of the adaptation of the human body to hyperbarism and its readaptation after decompression]

The data presented in the recent literature and the authors' results allow formulating basic positions of the conception on the phase adaptation to the increased density of gas mixtures (nitrogen, helium) with complete saturation. Each of the three phases is shown to depend on the intensity of hyperbaric stress and the organism state. A hypothesis is advanced that formation of the system functional and then a structural trace in possible in response to the repeated influences of prolonged hyperbarism. Cross deadaptation and decompensation of the systems which endure the highest functional load under hyperbarism are shown to be possible. A general syndrome of high pressures which unite nerve, respiratory, circulatory and metabolic components is characterized. Phases of the readaptation period are determined. Changes in main systems depending on periods after decompression are described.

[Morphofunctional features of lymph nodes, thyroid gland and testis of rats during adaptation reactions to stress and activation]

The morphofunctional state of lymphatic nodes, thyroid gland and testis have been studied with morphometric, cell photometric and biochemical methods in experiments on adult white rats under the influence of nonspecific adaptation stress and activation reactions caused by small doses of adrenaline (125 mg/kg and 5 mg/kg). The research showed that the changes in the structure and function of the lymphatic organs under stress and activation were markedly different. If stress results in depression of functional state of these organs, the activation reaction, on the contrary, stimulates it.

[Ultrastructural changes in somatotropinocytes of the adenohypophysis during development of transplantation immunity]

The authors conducted two series of experiments on 144 mice of BAL/c and C57B1 line. It was established that in autotransplantation submicroscopical changes developing in somatotropinocytes are typical of stressor situation and reflect various phases of general adaptation syndrome. An increase in the number of cells in the phase of active proteinic synthesis and degranulation is observed in allotransplantation in inductive phase of immunogenesis. Before rejection the number of cells in the phase of active proteinic synthesis is decreased, and in degranulation phase--is increased.