Search PubMed⌕ Search

Biomedical subjects

O G Gazenko

Publications and source records attributed to O G Gazenko.

97 records · Page 6Linked to original sources

[State of the microscopic and crystalline structures, the microhardness and mineral saturation of human bone tissue after prolonged space flight].

The bone tissue removed by autopsy from the crewmembers of the orbital station Salyut-1 after their 23-day space flight was investigated histologically, crystallographically, biophysically and biochemically. The comprehensive studies showed good correlation of the parameters studied. The microscopic and crystalline structures of bone tissue of every skeletal bone tested (ox calcis, frmoral epiphysis and diaphysis, vertebrae, ribs, sternum) did not differ from the normal. The data were in agreement with the parameters of bone microhardness and mineralization which also remained within the normal limits. No pathological changes in the above parameters were noted. Greater packing of the crystal lattice, increased microhardness and mineralization of bone tissue can be attributed to the effect of exercises.

Adult↗

[Basic results of the medical research performed during the flight of 2 crews on the "Saliut-5" orbital station].

The paper presents the results of medical examinations of the cosmonauts B. V. Volynov, V. M. Zholobov, V. V. Gorbatko and Yu. N. Glazkov during their 49- and 18-day flights aboard the orbital station Salyut-5. During the prolonged 49-day flight the cosmonauts developed symptoms of asthenization and fatigue. The medical monitoring of the cosmonauts showed increased blood filling of the head veins, increased arterial pressure and cardiac output. No significant changes were noted in the bioelectrical or contractile function of the myocardium. By the end of the flight the 49-day crewmembers showed a 4.5--7.0 kg decrease of body weight. They displayed a decline of orthostatic tolerance. This was especially marked in V. M Zholobov. Postflight biochemical changes were as usual but in the 49-day crewmembers they were more distinct. B. V. Volynov and V. M. Zholobov had moderate counts of protein and cell elements in the urine. It is concluded that space crewmembers ought to adhere strictly to their work-rest cycle and perform actively pressigned exercises.

Blood Pressure↗

[Use of the method of selective catheterization of the heart and major vessels in biomedical research with the participation of healthy persons].

The paper discusses the application of direct techniques to the study of circulation--catheterization of the heart and central vessels in biomedical experiments with the participation of healthy volunteers and during examinations of pilots, athletes, etc. The experiments showed high informativeness and reliability of the techniques and demonstrated their applicability to the study of gravity effects on the circulation and metabolism of different organs of healthy men as applied to aerospace and clinical medicine. These investigations allow clinical modelling of hemodynamic and metabolic changes that may develop in various organs and tissues in weightlessness, development of pathogenetically substantiated countermeasures against its adverse effects, formulation of certain requirements for artificial organs whose function should be as close as possible to that of natural organs of a healthy man. The paper presents the protocol and results of the first study of the effects of short-term simulated weightlessness on the circulation and metabolism of various organs of a healthy man: brain, heart, lungs, liver, kidneys, and musculoskeletal formations of the lower limbs.

Blood Circulation↗

[Protein and ribonucleic acid metabolism in the central nervous system of rats during space flight in the "Kosmos-605" satellite].

On the 2nd postflight day the activity of neutral protamine peptide hydrolase of different compartments of the rat brain did not differ from the control level. With respect to the protein and RNA content and concentration motoneurons of anterior horns of the spinal cord and their glial-cells-satellites of rats exposed to the ground-based synchronous experiment did not differ from those of vivarium controls, except cells of the supraoptic nucleus. That was found on the 2nd and 27th postflight days. On the 2nd postflight day the protein and RNA concentration in neurons decreased and the protein concentration and content in gliocytes lowered; the RNA concentration and content in Purkinje cells of the cerebellum became reduced. On the 27th postflight day the RNA concentration in neurons of the supraoptic nucleus remained diminished whereas the protein content increased; in spinal motoneurons the protein concentration decreased and in adjacent gliocytes the protein concentration and content lowered. All the above changes made no more than 15% of the control values.

Animals↗

[Preliminary results of medical research completed during the flight of the second expedition of orbital station "Salyut-4"].

The 63-day flight of cosmonauts P. I. Klimuk and V. I. Sevastyanov onboard the orbital station Salyut-4 has shown that man can well adapt to weightlessness and carry out diverse and intensive activities in the weightless state. Weightlessness effects on the human body may be both direct and indirect. The direct effects include reversal of deformations and mechanical tensions in tissue structures, change in the afferent impulsation from receptor zones reacting to the gravity effect, blood redistribution, disturbance in the function of sensory system. The indirect effects of weightlessness are associated with an unusual environment and unusual conditions of work rest, food and water consumption, etc. In the course of flight the human body adapts itself to the new environment; this is assured by self-regulation of physiological functions aimed at the maintenance of a constant level of vitally important parameters. Human adaptation to the weightless state can be subdivided into two periods: 1) period of adaptive rearrangement and 2) period of relative stabilization. The first period includes a rearrangement of functions and regulatory systems of the body. The second period can be defined as attainment of an intersystem homeostasis in the human body and a relatively stable equilibrium of the body with the environment. Incomplete adaptive reactions in shorter flights, e. g. during the first expedition of the orbital station Salyut-4 (G. M. Grechko, A. A. Gubarev), may be one of the factors responsible for a less favourable development of postflight readaptation. Thus, the most important purpose of the medical monitoring and prediction in prolonged space missions is to determine how complete or incomplete these adaptive reactions are. Relative stabilization can be reached, as a rule, after a 1.5 month exposure to weightlessness. However, this time period is rather relative since it depends on the characteristic features of the human body. The results of medical investigations carried out during and after the 63-day flight demonstrated no changes that could prevent from a further increase in the duration of future space missions.

Adaptation, Physiological↗