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Biomedical subjects

Z G Shishkanova

Publications and source records attributed to Z G Shishkanova.

At least 19 recordsLinked to original sources

[Influence of space flight factors on peripheral red blood cells in humans].

Investigations of cosmonauts' peripheral red blood prior to and on days 1, 7 and 14 post long-term MIR-19 and -20 missions dealt with the morphological composition of blood, indices of iron exchange, correlation of erythrocyte shapes, and the lipid and phospholipid profiles of the erythrocyte membrane. To this avail, methods of light electron microscopy, radioimmune analysis, and thin-layer microscopy were used. Among the unidirectional shifts in the crewmembers of these missions were changes in ion exchange indices and the lipid and phospholipid profiles of erythrocyte membrane which were indicative of increased microviscosity of the lipid layer. Number of erythrocytes and hemoglobin content were reduced; transformed erythrocytes were present. It was also discovered that the fraction of normal erythrocytes (diskocytes) was partially replaced by spherocytes, cnisocytes in flight and typically by echinocytosis post flight. By and large, the observed shifts do not have any clinical implications and are most likely the blood system reaction to the stress of readaptation to the terrestrial conditions.

Astronauts↗

[Hematological investigations in conditions of long-term space flights].

In the nearly 15-month mission aboard MIR the cosmonaut-physician and members of three crews (MIR-15, -16, and -17) carried out a program of hematological investigations. Most of the changes related to the red blood system and included reduction in hemoglobin and hematocrit. Erythrocytes had decreased concentration and took on abnormal forms. There were also signs of altered metabolism of erythrocytes. Of interest are phase-by-phase variations in the levels of erythrocytes in the course of long-term stay in microgravity, and absence of a convincing correlation between hemoglobin, erythrocyte and hematocrit levels. But for lymphocytosis that returned to the norm already on the first day of recovery, no material changes occurred to the leukocyte profile. Investigations at the landing site displayed erythropenia, decreased reticulocytes and ensuing reticulocyte reaction, and gradual regain of the erythrocyte number that can be viewed as a normal physiological reaction of the blood system to the set of factors of spaceflight and early readaptation. Besides, the investigations showed a large individually of blood reactions to prolonged stay in space flight.

Adaptation, Physiological↗

[The effect of head-down tilt bed rest on metabolism of erythrocytes and functional state of membranes in females].

Metabolism of erythrocytes and the structural/functional state of membranes were studied in females in the 120-day head-down bed rest and the subsequent period of recovery. As was stated, prolonged bed rest and early recovery cause shifts in the metabolic and structural parameters of erythrocytes and ensuing degradation of the functional state of erythrocytes, i.e. changes in deformability and echinocytosis. The system of countermeasures including exercise and a set of alimentary supplements with polysaturated fat acids and antioxidants, proved to moderate the changes although it failed to fully eliminate them.

Adult↗

[Metabolic and structural aspects of cellular homeostasis in long-term isolation].

Metabolism and structural/functional status of membrane of blood cells (erythrocytes, lymphocytes) were investigated in human subjects during simulation of MIR environment and operations, and postflight activities. Homeostasis of the blood count cells was assessed by the parameters of intercellular metabolism. Histochemical technique was used to evaluate the activity of mitochondrial enzymes succinate dehydrogenase and alpha-glycerphosphate dehydrogenase in lymphocytes. State of the erythrocyte membrane was judged about by the lipid and phospholipid spectra, activity of transport ATPase and shape of erythrocytes were determined with the electronscan microscopy. Adaptational shifts in erythrocyte metabolism were particularly marked on days 22 and 113 in the experiment, and day 1 of recovery. They appear to be associated with alterations on the membrane level. Therefore, simulation of a long-term MIR mission produces changes in cellular metabolism and status of cellular membranes concurrent to the readjustment of body controls due to, probably, shifts in the sympathoadrenal system. Destabilization of the cellular membrane could be also linked with plasmic factors, e.g. increases in bile acids, lysolecithin, Ca ions, etc., in consequence to changes in lipid metabolism and electrolyte status.

Adaptation, Physiological↗