Biomedical subjects
Publications and source records attributed to A M Genin.
The article includes excerpts from The Bioethic Rules of Research With Humans and Animals that have established on analysis of national and international bioethic guidelines for biomedical research with the use of humans and animals and are a part of the ISS human use guidelines.
Explore the source record for details and available documents.
The paper deals with ethic concerns of biomedical research involving human subjects aimed at mitigating risks for and raising the effectiveness of humans in extreme environments. Cited are the main principles of the Nuremberg Code, Helsinki Declaration, Convention of the European Council on Bioethics and other international and national documents regulating ethic implementation of research with participation of human subjects. The 6-year experience of the Bioethics Commission convened at SRC RF--IBMP is summarised.
The article describes the procedure of determining methane and some organic trace elements in expired air during simulated "dive" in a hyperbaric chamber. Partial pressures of methane breathed out by divers in 29 experiments are reported. Concentrations of 8 trace organic components have been measured in the expired air of two divers. The results obtained show that expired methane increases by 3-10 times during simulated descent down to 80-115 m.
Reactions of external respiration on catheterization of main blood vessels were studied in healthy subjects following 12 hr and 5-6 day immersion. The purpose of the investigation was to detect respiratory signs of hyperemia in pulmonary circulation under these conditions. Results of the investigation were compared with the data of great vessel catheterization in patients of a cardiological clinic afflicted with cardiac diseases with lung hyperemia and lung tissue hyperhydration. The results obtained failed to confirm suppositions about elevated blood filling of the lung and a possible increase of lung tissue hydration during water immersion. Catheterization of great vessels in patients and healthy subjects in most cases leads to an increase of respiratory minute volume. In patients with cardiac diseases the respiratory minute volume grew with an adequate rise in breathing rate, respiratory volume and gas exchange parameters unaltered; this suggested excessive blood filling of the lung and resulting higher respiratory resistance. After immersion the healthy subjects displayed an utterly different pattern, i.e. the growth of their respiratory minute volume was provided exclusively by the growth of respiratory volume while breathing rate did not change and gas exchange increased. These observations were considered an evidence of hyperemia and hyperhydration of pulmonary tissue.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The major goal of medical investigations in the USSR longterm (up to 6 months) manned space flights was to accumulate information on human responses to prolonged weightlessness. Before, during and after these flights, detailed clinical, physiological, immunological and anthropometric examinations were conducted. The examinations demonstrated that man may well adapt to long-term space flight, retaining good health and a high work capacity. The changes seen postflight were reversible and disappeared completely after a relatively short readaptation period. Postflight changes did not correlate with the flight duration. A reasonable work-rest cycle and various physiological countermeasures were used, the efficiency of which were substantiated by means of regular medical examinations. These methods helped the cosmonauts to maintain good health status and adequate performance inflight and facilitated their readaptation postflight. Medical investigations performed during the Salyut-6 flights indicate that the duration of manned space flight can be increased.
Explore the source record for details and available documents.
In the 18.5-day flight of the Soviet biosatellite Cosmos-936 (3-22, August 1977) com-parative investigations of the physiological effects of prolonged weightlessness (20 rats) and artificial gravity of 1 g (10 rats) were carried out. Throughout the flight artificial gravity was generated by means of animal rotation in two centrifuges with a radius of 320mm. Postflight examination of animals and treatment of the flight data were performed by Soviet scientists in collaboration with the specialists from Bulgaria, Czechoslovakia, the German Democratic Republic, Hungary, Poland, Rumania, France and the U.S.A. During the flight the total motor activity of the weightless rats was higher and their body temperature was lower than those of the centrifuged animals. Postflight examination of the weightless rats showed a greater percentage of errors during maze an increase in water intake and a decrease in diuresis; a fall of the resistance of peripheral red cells; an increase in the conditionally pathogenic microflora in the mouth; a decrease of oxygen consumption, carbon dioxide production and energy expenditures; a drop in the static physical endurance; a decline in the capacity to keep balance on the rail; an increase in the latent period of the lifting reflex, etc. The centrifugal animals displayed lesser or no change of the above type. These findings together with the biochemical and morphological data give evidence that during and after flight adaptive processes in the centrifuged rats developed better.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
In 1975 the Soviet Union performed two manned flights on board the orbital station Salyut 4. The first mission of 30 days was flown by A. A. Gubarev (Commander) and G. M. Grechko (Flight Engineer) and the second mission of 63 days by P.I. Klimuk (Commander) and V.I. Sevastyanov (Flight Engineer). The present paper gives preliminary data on the general health and cardiovascular investigations of the crew members during and after flight. The clinical and physiological examinations of the cosmonauts showed that the work-rest cycles and counter-measures used helped to maintain their good health and high performance in flight, to alleviate adverse reactions and to facilitate readaptation post-flight. Medical results of the post-flight investigations revealed no changes that may detract from further increasing the duration of manned space missions.
The purpose of the medical investigations carried out in flights of the Soviet orbital station Salyut were: to further studies and clarification of the phenomenology and mechanisms of changes in the main functions of the human body during prolonged weightlessness; to accumulate additional data on human responses at an early stage of adaptation to weightlessness; to assess the effectiveness of countermeasures against adverse effects of weightlessness during and after flight. The orbital station was equipped with a set of countermeasuring devices: a trainer for physical exercises (a treadmill), gravity simulation suit for long wear, bicycle ergometer, anti-G suit to be worn immediately post-flight, drugs, etc. The system of medical control included daily recordings of electrocardiography and respiration and regular physical examinations using provocative tests (physical exercises of a known force, lower-body negative pressure). Specific biomedical investigations were performed before, during and after flight. As in previous flights, the atmosphere in the habitable modules was similar to that on the earth. Food supply met the requirements for basic nutrients and satisfied individual preferences of the crew members. In addition to the time required to fulfil the flight programme, the work-rest schedule allowed the cosmonauts 8 hours sleep, four meals, 2.5 hours physical training and personal time. The biomedical investigations carried out during and after flight furnished information towards a better understanding of human responses to the effects of space flight factors and the mechanisms underlying their development.
The results of biomedical investigations carried out in the U.S.S.R. manned space missions are discussed. Their basic result is well-documented evidence that man can perform space flights of long duration. The investigations have demonstrated no direct correlation between inflight or postflight physiological reactions of crewmembers and flight duration. In all likelihood, this can be attributed to the fact that special exercises done inflight efficiently prevented adverse effects of weightlessness. However, human reactions to weightlessness need further study. They include negative calcium balance and anemia as well as vestibulo-autonomic disorders shown by crewmembers at early stages of weightlessness. Attention should be given to psychological, social-psychological and ethical problems that may also limit further increase in flight duration.
Three cosmic experiments were performed in which rats spent 18-20 days in space on board the biosatellites "COSMOS 782", "COSMOS 936" and "COSMOS 1129". The following indicators of the sympathetic-adrenomedullary system (SAS) activity were measured: tissue and plasma catecholamines (CA), CA-synthesizing enzymes--tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH), phenylethanolamine-N-methyltransferase (PNMT)--as well as CA-degrading enzymes-monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT). Adrenal epinephrine (EPI) and norepinephrine (NE) as well as CA-synthesizing and degrading enzymes were not significantly changed in the animals after flight on COSMOS 782. On the other hand, a significant increase was found in heart CA, the indicator which is usually decreased after stress. 26 days after landing all values were at control levels. The results obtained, compared to our previous stress experiments on Earth, suggest that prolonged weightlessness does not appear to be a pronounced stressful stimulus for the SAS. Heart and plasma CA, mainly NE, were increased both in the group living in the state of weightlessness and the group living in a centrifuge and exposed to artificial gravitation 1 g (COSMOS 936), suggesting again that prolonged weightlessness is not an intensive stressful stimulus for the SAS. The animals exposed after space flight on COSMOS 1129 to repeated immobilization stress on Earth showed a significant decrease of adrenal EPI and an expressive increase of adrenal TH activity compared to stressed animals which were not in space. Thus, the results corroborate that prolonged state of weightlessness during space flight though not representing by itself an intensive stressful stimulus for the sympathetic-adrenomedullary system, was found to potentiate the response of "cosmic rats" to stress exposure after return to Earth.