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Biomedical subjects

G V Katsiia

Publications and source records attributed to G V Katsiia.

At least 19 recordsLinked to original sources

[Dehydroepiandrosterone and the cerebral functions].

Of all steroidal hormones, dehydroepiandrosterone (DHEA) and its sulphate form, DHEAS, are synthesized by the adrenal glands in the biggest quantities. In this review the authors consider the ways of the synthesis of the neurosteroids, possible mechanisms of the regulation of these processes, and their dynamics under stressful conditions. The paper presents analysis of experimental and clinical data on the role of DHEAS in the manifestation of different cerebral functions. The authors pay special attention to the results of substitutive therapy with DHEA(S) in patients with such CNS functional disorders, as Alzheimer's disease, depression, age-relative memory and sleep disturbances, etc.

Adjuvants, Immunologic↗

[Dehydroepiandrosterone and brain functioning].

The adrenal glands synthesize dehydroepiandrosterone (DHEA) and its sulphate form (DHEAS) more intensively than they do other steroid hormones. Researchers are interested in these hormones for several reasons. Firstly, for some years they have been trying to find the reason for DHEA and DHEAS to be synthesized and present in the organism in such high concentrations. Secondly, their attention have been attracted by age-dependent regression of DHEA, which is strictly determined. Thirdly, despite longstanding efforts of scientists, the physiological role and spectrum of the biological activity of DHEA is still unclear. Evidence of that DHEA and DHEAS can be synthesized in situ in the brain tissue, received in rat experiments, urged researchers to clarify the role of these neurosteroids in the CNS. The presented review covers ways of neurosteroid synthesis, possible mechanisms of the regulation of these processes, and their dynamics under the condition of stress. The authors analyze experimental and clinical observations undertaken with a goal to clarify a possible role of DHEA in the manifestation of various brain functions. Special attention is payed to ambiguous results of modern studies, dedicated to replacement therapy of various disorders of CNS functioning (Alzheimer's disease, depression, age-specific memory impairment, sleep disturbance etc.) with DHEAS.

Adult↗

Results of hospital bypass angiography in patients with coronary artery disease undergoing arterial and vein myocardial revascularization.

This paper analyzes the results of 94 coronary artery bypass grafts accomplished at the Department of Surgical Treatment of Concomitant Lesions of Coronary and Peripheral Arteries, A.N. Bakulev SCCVS, RAMS, in patients with coronary artery disease (CAD) provided control hospital bypass angiography over the period 1998 to 2002. Control bypass angiography revealed thrombosis of 11.7% of vein and of 1.5% of arterial grafts. The main causes of vein graft thromboses were: bypass grafting of small coronary arteries, that of the coronary arteries with so-called 'immature' stenoses, and mediastinitis. The data presented herein evidence that hospital arterial bypass graft provides for a considerably higher percentage of competence versus vein bypass graft. Hospital bypass angiography is essentially safe while its findings allow to make a detailed analysis of complications whereby upgrading the efficacy of operations.

Arteries↗

[Effect of immobilization stress on the gonadotropic function of the hypophysis in male hamadryas baboons (Papio hamadryas)].

The plasma levels of luteinizing hormone (LH) and testosterone were studied in intact and castrated male baboons exposed to 2- and 10-hour periods of immobilization. Presented data have shown that immobilization stress induced a marked decrease in LH concentration both in intact and castrated monkeys. Changes in LH concentration positively correlated with plasma levels of testosterone only during the experimental procedures. During three days after immobilization there was a sharp dissociation in the dynamics of testosterone levels remained low and LH returned to normal values. We can suggest that it is not absolute LH level that is responsible for the changes in testosterone secretion during the immobilization stress.

Animals↗

[Psychopathological and hormonal manifestations of alcoholic intoxication and emotional stress in monkeys].

Ethological approach to studying mature P. hamadryas and M. mulatta males has revealed a wide spectrum of changes in individual and zoosocial behaviour in response to the administration of different alcohol doses and stress stimuli. It has been established that neuroendocrine basis for the depression of psychic and locomotor activities developing in conditions of alcohol intoxication and emotional stress is an extremely high release of catecholamines and the increase of glucocorticoid secretion accompanied by a sharp decrease in androgen products. It should be noted that the exposure to stress stimuli during consumption of small alcohol doses intensifies depression-like stress-induced behaviour of monkeys.

Alcoholic Intoxication↗

[Effect of ACTH on the corticosteroid and progesterone levels in female hamadryas baboons in relation to the menstrual cycle phase].

The effect of exogenous ACTH on the endogenous function of the steroid-producing glands has been investigated in hamadryas baboon females depending on the level of sex hormones in the body. The content of corticosteroids and progesterone in peripheral blood plasma was measured by radioimmunoassay. It has been established that the time course of changes in the adrenal gland response to administration of a standard ACTH dose was of the same type in the different menstrual cycle phases. The inhibitory effect of ACTH on progesterone secretion in ovarian corpus luteum being active has been revealed.

Adrenal Cortex Hormones↗

[Circadian rhythms of the sex steroids of female Papio hamadryas in long-term hypokinesia].

Radioimmunoassay was used to study the effect of restricted motor activity on circadian rhythms of blood plasma sexual steroids and cortisol in female Papio hamadryas during different phases of the menstrual cycle. Instact animals manifested clear-cut circadian rhythms of the testosterone and cortisol content during both the phases and those of estradiol and progesterone during the follicular phase of the cycle. Two-week immobilization did not produce any changes in the general pattern of circadian rhythms of cortisol and testosterone but led to a decrease in their mean daily concentrations, with that decrease being more pronounced for testosterone of females immobilized during the luteal phase. The authors established unbalance of sexual steroids with a dramatic fall of the mean daily concentrations of estradiol and progesterone and desynchronism of their circadian rhythms regardless of the cycle phase at the moment of immobilization. The mechanisms responsible for alterations in circadian rhythms of sexual steroids in hypokinetic females are discussed.

Animals↗

[Testicular endocrine function in hamadryas baboons (Papio hamadryas) during chronic emotional stress].

Radioimmunoassay was applied to examine the time course of blood plasma testosterone content in 10 adult male hamadryas baboons under repeated immobilization stress (IS). In the first series of experiments, the monkeys (5) were subjected to daily IS for 2 h during 6 days. In the second series, 5 animals were exposed to 2-hour immobilization 3 days prior to the analogous stressful cycle. In response to intermittent IS the first series males demonstrated profound and long-term suppression of blood testosterone that persisted for 2 days after IS cessation. Preliminary application of a stressful stimulus substantially reduced the degree of blood testosterone suppression. Transitory decrease in blood testosterone was observed 2 hours after the outset of each stressful exposure, followed by complete recovery of testosterone blood level after 6 hours. The differences in the time course of testosterone indicate that the response of the pituitary-gonadal system is dependent on the regimen of stressful stimulus application.

Animals↗

[Nature of changes in the level of steroid hormones and their precursors in peripheral blood of Papio monkeys under stress].

The radioimmunological method was applied to determination of changes in the peripheral blood plasma level of 12 steroids in male Papio hamadryas under immobilization and surgical stress. Androgen content decreased, and the concentration of steroid hormone precursors and hydrocortisone blood plasma content rose in response to stress. These changes were in contraphase with the circadian steroid rhythms. The most objective and sensitive criteria of the stress situation evaluation were decrease of testosterone and dihydrotestosterone level, increase of pregnenolone concentration, as well as of 17-alpha-hydroxypregnenolone, 17alpha-hydroxyprogesterone in the blood plasma.

Androgens↗

[Radioimmunologic method of determining 11 steroids in small samples of monkey blood plasma].

A radioimmunological method is described for simultaneous estimation of hestagenes, estrogenes, androgenes and their precursors in small samples of blood plasma obtained from peripheric blood of hamadryads (Papio hamadryas) and macaques (Macaca rhesus). Use of highly specific antisera and of chromatographic isolation of each steroid on columns with celite enabled to estimate the concentration of 11 steroids in 1.1 ml of blood plasma with high accuracy. Standard curve and analysis of its linearity were carried out in the coordinate system logit-log.

Androgens↗