[Effects of small ionizing radiation doses on hemato-encephalic barrier permeability].

Goal and objectives of the study was comparative description and establishment of dose-time dependence of changes in permeability of the hemato-encephalic barrier (HEB) in phylogenetically different parts of the brain cortex, i.e. new (Fr2 and Cg3), old (hippocampal fields CA1-CA4 and dentate fascia) and paleocortex (piriform cortex) following exposure to 0.

[Morphofunctional evaluation of different parts of the cerebral cortex after ionizing radiation exposure].

The investigation has the aim to compare reactions of phylogenetically different parts of the brain cortex to single and fractionated irradiation by 1 Gy. The focus is primarily laid on unveiling the morphological stage of radiation-induced changes in the cortex. A hundred of 100 nubilous male rats with the body mass of 200-230 g were subject to whole-body uniform single and fractionated gamma-irradiation (total dose absorption over 5 days) with MeV spectrum 1.

[Adaptive process in Vietnamese military pilots during the flights on modern Russian aircraft].

Study on health status of 156 Vietnamese military pilots on Russian modern jet planes (Su-22, Su-27, Su-30, MiG-21B). The results showed that unprofitable factors in working environment (acceleration, radiation, high temperature, humidity, noise) have an impact on the health of pilots during the flight, leading to deterioration of professional health and physiological functions (cardiovascular, respiratory and nervous system) and obesity of pilots after 35 years old. Basing on the studies, we suggested some measures for health protecting, safety of flight and prolonging flight-activity of pilots (training in decompression chamber, vestibular training) and balance in food ration for prevention of professional diseases.

[Investigation into microcirculation in the vascular bed of healthy people and patients at rest and during the LBNP test].

Computer capillaroscopy during the lower body pressure test (LBNP) provided additional information about the effects of orthostasis on blood microcirculation and separate estimation of blood velocity in arterial, intermediate and venous segments of capillaries. Microcirculation was demonstrated to be sensitive to the LBNP exposure as in healthy volunteered subjects, so in ischemic, including hypertensive, patients. The highest velocity of capillary blood and the lowest Kv were determined in ischemic patients including hypertensive, in whom venous velocity in capillaries prevailed over arterial (Kv < 1), whereas in healthy subjects Kv never fell below 1.

[Mathematical algorithm for evaluation of the human cardio-respiratory homeostatic function].

Mathematical algorithm of the cardiorespiratory homeostasis was determined by oxygen demand (VO2) and carbon dioxide production (VCO2) during maximal physical loading on the bicycle ergometer; calculated and measured parameters of the physical capacity were compared in experiments with long-term (110- to 240-d) isolation of human subjects. Aerobic capacity was evaluated during incremental physical testing in the sitting position on bicycle Elema-Siemens 380-B. The following parameters were measured: peak (maximal loading) heart rate (HRpeak) and VO2, work time, and VO2 at 15 points on the Borg load scale, total aerobic test time and some others.

[Comparative evaluation of several methods preventing orthostatic disorders during simulation of the end-of-space-mission factors].

A new method for mitigation of the negative consequences of blood shift toward the cranial end as a result of simulation of the hemodynamic effects of microgravity (head-down tilt at -6 degrees) combines the lower body negative pressure (LBNP) and negative pressure respiration (NPR) to accelerate blood outflow from cerebral vessels and, additively, to restrain blood inflow from the lower body. The longitudinal hydrostatic pressure gradient is thus reproduced but main hemodynamic parameters assume values characteristic of the vertical posture. The objective was to compare the strength of LBNP and LBNP + NRP training in preventing orthostatic disorders following 7-d HDT.

[Respiration and cardiovascular mechanisms of hypobaric correction of the head-down redistribution of local blood volumes].

The focus was placed on the physiological mechanisms of correction of the blood redistribution during the head-down tilt (HDT) with a discrete or complex use of the methods of negative pressure respiration (NPR) and lower body negative pressure (LBNP). It was evidenced that rise in the intracranial hydrostatic pressure in HDT (-6 degrees) can be compensated by NPR within a range of -10 to -15 cm of water column causing decrease in the intrasternal pressure from -5.04 to -7.

[Work capacity evaluation and orthostatic tolerance in experiments with long-term isolation].

Orthostatic tolerance (OT) and physical performance were tested against the ground simulation of several spaceflight factors. Before and after prolonged isolation and confinement three human subjects were tested by tilting, LBNP, and graded incremental aerobic exercise in the sitting position. Results suggested good OT in all the subjects.

[Prediction of maximum oxygen uptake during physical exercise on bicycle ergometer].

Possibilities to predict maximum oxygen uptake (VO2max) during exercising on bicycle ergometer using the Russian Rating Perceived Exertion (RPE) was studied. Results of examination of 13 athletes demonstrate the possibility of predicting individual and group average VO2max on the basis of data from submaximum testing and the empirical formulas from the value of VO2max registered at RPE numbers 13 and 15. These VO2max values can serve as markers for assessing the dynamics of physical performance.

[Maximal anaerobic capacity of man in a modified Wingate test].

We studied the possibility of using a 380B Siemens-Elema (Sweden) bicycle ergometer to determine the maximal anaerobic capacity of healthy subjects during a modified Wingate test. Exercise was performed under stable moment conditions, with calculation of braking resistance on the basis of the subjects lean body mass. The values of total work performed and maximal power may be used for comparative evaluation of physical work capacity in participants of training and rehabilitation programs.

[Bodily heat resistance and polymorphism of liver esterases of grass frogs].

The determination of organismal heat resistance and qualitative composition of polymorphous liver esterases during heat acclimation (25 degrees) has been made on frogs Rana temporaria. During hybernation the most heat resistant frogs possess the homozygous allele of A2 esterase. Heat acclimation and the summer rise in temperature in nature lead to an increase in heat resistance of frogs and to the disappearance of selective advantage of animals possessing the isoenzyme of the A2A2 esterase.

[Method for detecting the relationship between the initial degree of cellular resistance and its changes under the effect of the stimulants].

Methods have been elaborated for detecting the individual changes in the resistance of cells on the basis of the analysis of alcohol- and heat resistance of isolated muscles of Rana temporaria L. A correlation has been determined between the initial resistance level of cells and its change induced by experimental effects. This method allows to identify a really existing relation as opposed to the seeming one caused by random factors.