Study of iron,zinc, stable strontium,and lithium contents in biological fluids and tissues in an experiment simulating space flight conditions

Atomic emission spectral analysis with inductively coupled argon plasma was used to measure contents of iron, zinc, stable strontium, and lithium in blood serum and its ultrafiltered fraction, as well as the level of their excretion in 24-h urine and hair, in a ground-based experiment simulating space flight conditions. The monitoring of iron levels of serum and its ultrafiltered fraction has shown a proper balance between the indicated parameters at all stages of the experiment. The iron forms bound to protein carriers were identified only in blood serum. The study in the conditions of the experiment has shown the dependence of blood serum zinc content on the nutritional status. The level of stable strontium excretion with 24-h urine can serve as a biological indicator of changes in its homeostasis. The experimental conditions have not been found to affect the form of serum lithium; i.e., lithium was invariably present in the ionized state and its content remained equal to the amount of ultrafiltered lithium in all blood samples investigated in all experimental periods.     

A multifactorial study on the relative postradiation changes in various categories of behavioral reactions in rats

The use of the methods of multifactor, orthogonal and composition planning in studying the behavioural disturbances in rats after gamma irradiation with doses of 0.258 to 1.29 C/kg and the application of the proposed method of discrimination of effects by empirical models permitted to establish the informative and adequate dependences of the probability of these disturbances on dose of nonuniform irradiation and the degree of strengthening of the conditioned reflex. It was shown that the effect of radiation decreased, in a discrete manner, the probability of making the first decision by rats in a behavioural task (here we deal with the "dose-response" function). The average time of making the first decision after irradiation was invariable within the dose range under study. Within the range of the studied factors both the value of the dose of whole-body irradiation and the degree of strengthening of the conditioned reflex significantly affected the probability of fulfilling the task by the animals the significance of the radiation dose being several times higher. The effects of the interaction of the two factors, that is, irradiation and the degree of the radiation affection, were insignificant in changing the behavioural reactions under study.     

Radioprotective properties of a radioprotector of emergency action indraline at its adminisration after irradiation in conditions of local shielding of a rat abdomen

In experiences on white rats at a gamma-irradiation in a lethal dose LD97/30 in conditions of local schielding of an abdomen (in the field of a liver) and application of a radioprotector indraline after irradiation the expressed efficiency of combined protection up to 87.5% is scored at 31.3% of a survival in local schielding of an abdomen group and absence of effect from a drug.     

The use of the method of anomalous time dependence of viscosity for registration of changes in the nucleoide conformation. Part 1

The sensitivity of the method of anomalous time dependence of viscosity to changes in the conformation of DNA-protein complexes (such as nucleoide) by the action of increased temperature (33, 70 and 85 degrees C) and the combined action of temperature and Na+, Cl- ions on lysates of Escherichia coli AB1157 cells has been studied. The optimal conditions of the cell lysis was determined on the basis of the curve parameters of the anomalous time dependence of viscosity.     

The role of thiol redox systems in the response of <Emphasis Type="Italic">Escherichia coli</Emphasis> to far-UV irradiation

Escherichia coli mutants deficient in glutathione (gshA), glutaredoxin (grxA), thioredoxin (trxA), and thioredoxin reductase (trxB) synthesis were studied with respect to their resistance to far-UV (UV₂₅₄) exposure. The trxA, trxB, and grxA mutants subjected to a short-term UV exposure were found to be more resistant to UV irradiation than the parent cells. Under the same conditions, the trxA and trxB mutants demonstrated a high level of induction of the sulA gene, a component of the SOS regulon. The mutagenic effect of long-term UV exposure of all the mutants with redox deficiencies was more pronounced than in the case of the parent strain, and the trxA and trxB mutants were found to be the least viable microorganisms. Pretreatment of the cells with low concentrations of the thiol-oxidizing agent diamide enhanced the sulA gene expression; however, high concentrations of diamide inhibited sulA expression. The data obtained indicate that the thiol redox systems of E. coli are involved in its response to far-UV irradiation.     

Pharmacologic Protection in Distant Space: Current View

Biology Bulletin - The radiation risk for astronauts in long space flights depends on the impact of low-intensity galactic and solar radiation on the spaceship. There is a small possibility of high...     

I.M. Sechenov's creative development of ideas in aviation and space medicine

Research carried outby the great Russian scholar I. M. Sechenov has significantly contributed to development of aviation physiology, medicine and psychology. His fundamental works consisted of discovery of the constancy of alveolar air composition theory, study of interactions of analyzers systems in solving the problem of human spatial orientation under flight conditions, development of a nervous theory of fatigue. Creative development of ideas by I. M. Sechenov allowed enhancing the efficiency of performing and safety of aviation and space flights.     

The influence of combined application of quercetin and indralin on post-irradiation repair of hematopoiesis in acute radiation injury

Experiments on mice-hybrids F1(CBA x C57B1/6) have detected a favorable effect of the associated application of quercetin (30-60 minutes before y-exposure of an animal) and a radioprotectant of urgent action indralin (in the case of its application after y-exposure) on a post-irradiation repair of the hematopoietic tissue in acute radiation sickness after y-exposure at a non-lethal dose of 6.7 Gy, which manifested itself in the accelerated formation of endogenous spleen colonies and spleen mass recovery, as well as in the lesser degree of leukopenia on the 12th and the 16th day after acute radiation injury. Quercetin per se did not have a radio-protective effect.