Adaptation of the Human Body to Simulated Weightlessness: Clinical Studies

Problems of adaptation of functional systems of the human body to conditions of continuous weightlessness are considered (prolonged stay under conditions of antiorthostatic hypokinesia and in an immersion medium). It was revealed that, during adaptation to these conditions, polymorphic clinicofunctional disorders develop, transforming into clinicophysiological syndromes, the most frequently observed being autonomic vascular malfunction, asthenoneurotic syndrome, detraining of the blood circulatory system, trophic and neuromuscular disorders, statokinetic syndrome, pain syndrome, and metabolic and hormonal disorders. The severity of the specified disorders and the duration of the recovery period depend on the duration of hypokinesia and the intensity and regularity of application of preventive measures during hypokinesia. The most probable pathophysiological mechanisms of adverse effects of continuous hypokinesia (maladaptation) on functional systems of the human body are described.     

The study of the surface layer of 3D-matrices for tissue engineering

Matrices fabricated by electrospinning from polycaprolactone solutions with human albumin or gelatin to 1,1,1,3,3,3-hexafluoroisopropanol have been investigated. Microstructure of matriх surface was analyzed using scanning electron microscopy. Protein distribution in the surface layer was studied by modification with N-(2-hydroxyethyl)phenazine and X-ray photoelectron spectroscopy. The protein concentration in the surface layer of matrices was up to 12 times higher than in the initial solution, and the lower the protein concentration in the solution, the higher the relative protein content is on the surface of matrices. During incubation of matrices in aqueous solutions protein concentration in the surface layer decreased by less than 10% during the first 30–60 min and remained at this level for a long time (seven days). Treatment with proteinase K resulted in about one-third decrease in protein concentration in the surface layer. Thus, both methods used in this study are applicable for analysis of the surface layer of materials fabricated by electrospinning from mixtures of synthetic and natural polymers; however, X-ray photoelectron spectroscopy appears to be a more informative and convenient method.     

RNA editing: Classical cases and outlook of new technologies

This article provides an overview of the studied RNA editing cases and examples of prediction errors at RNA editing sites, as well as ways to minimize them. The outlook of state-of-the-art technologies and future RNA editing studies is discussed.     

Addressed enzymatic fragmentation of RNA molecules

RNase H has been used for selective cleavage of RNA of MS2 and R17 bacteriophages and 16S RNA from E. coli ribosomes in the region of formation of heteroduplex composed of RNA and an oligodeoxyribonucleotide complementary to a certain part of it. The oligonucleotides used--d(C-T-C-A-T-G-T-T-), d(C-C-A-T-C-T-T-T-T) and d(T-T-T-C-C-A-T-C-T-T-T-T)--were synthesized by chemical methods. The molecular weight of the fragments produced on cleavage of the RNA of MS2 and R17 were estimated with the use of gel electrophoresis under denaturating conditions. The dependence of the enzyme activity on Mg2+ and Na+ concentration and of RNA cleavage on the RNA: oligodeoxyribonucleotide ratio was investigated.     

The safety of a new chemical typhoid preparation containing a complex of Vi and K antigens in tests of its acute and chronic toxicity]

Acute and chronic toxicity of a new chemical typhoid preparation containing the complex of surface Vi- and K-antigens has been studied. The study has revealed that the preparation, when introduced subcutaneously and intravenously in immunizing doses in a single injection or in multiple injections, produces no toxic effect on the organs and tissues of experimental animals. In experiments of chronic toxicity the microscopic study has shown pronounced hyperplasia of the lymphoid system with enhanced macrophage reaction in the spleen, thymus, mesenteric lymph nodes and Peyer's patches in the small intestine.     

Toxicity and pharmacological properties of carminomycin complex components]

Acute toxicity of the components of the carminomycin complex after intravenous administration to albino mice increased as follows. I less than II less than III. Component II induced a decrease in all the indices of the bone marrow and peripheral blood of the animals. It was most pronounced in dogs. The dogs died after administration of component II in the lethal doses as a result of the bone marrow aplasia. The indices of the functional state of the liver and kidneys in the animals after administration of components I and II changed slightly. Component III administered repeatedly to rabbits even in low doses induced significant impairments in the function of the liver and kidneys. Component II differed from component I by more pronounced cardiotoxicity. On the basis of the experimental data and the results published earlier component I is recommended for clinical trials as the least toxic one.     

Enterotoxigenic Escherichia in patients with acute intestinal infection

Out of 4,082 Escherichia strains isolated from 989 hospitalized patients with acute enteric infections 2,979 strains belonged to 139 O-groups and the remaining strains could not by typed with O-sera (O1-O164) or were in the serological R-form. 19.3% of the strains isolated from 354 patients showed a positive reaction for thermolabile enterotoxin (TLET) determined in the radioimmunoassay. Escherichia with pronounced reaction for TLET were isolated from 5.5% of the patients. The serological picture of Escherichia with a positive reaction for TLET comprised 78 O-groups, showed practically no variations in children of different age and adult patients and was related to the intensity of reaction for TLET. The number of enterotoxigenic Escherichia greatly varied within individual O-groups: from 3.1 +/- 3.63% (O11) to 100 +/- 9.81% (O114) of the total number of known strains in these O-groups. In most O-groups the number of enterotoxigenic strains varied from 10% to 50%. The most widely spread serovars of etiologically important enterotoxigenic Escherichia belonged to 24 O-groups and were often isolated as monocultures. The capacity for producing TLET (and, probably, some other antigenically related substances) in widely spread among Escherichia; still, the determination of enterotoxicity is a necessary, but not sufficient criterion of their etiological importance in acute enteric infections.