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Biomedical subjects

E P Senchenkov

Publications and source records attributed to E P Senchenkov.

14 recordsLinked to original sources
PubMed1985

[Stereological analysis of phagocytosing cells].

Various complexes of phagocytes with adsorbed (I) and entrapped (J) particles are formed during phagocytosis. Method of stereological reconstruction is proposed that allows to demonstrate the actual distribution of these complexes on the basis of morphometric analysis of their ultrathin sections. The principle of the method lies on the probability simulation of section distribution for a given distribution of complexes and on the solution of the reverse problem by stepwise determination of the relative quantity of each complex type (from the most complicated to the most simple one, when I = 0 and J = 0). The stereological analysis of phagocytosing murine peritoneal macrophages revealed an absolutely different and more adequate kinetical picture of phagocytosis, as compared to the morphometric data.

Absorption↗
PubMed1983

[Acidification kinetics in macrophage phagosomes based on flow cytometric data].

Using flow cytofluorimetry, acidification in macrophages was studied during phagocytosis of yeast cells Candida albicans conjugated with FITC. Two phases of acidification were found: one corresponding presumably to yeast cell absorption on the macrophage surface, and the other one being due to cell incorporation into phagolysosomes. The phases are characterized by pH values of 6.3 +/- 0.5 and 4.5 +/- 0.5, respectively. Addition of 10 mM NH4Cl cancelled the observed acidification, whereas the presence of cytochalasin B (2 . 10(-5) M) prevented the very process of acidification.

Animals↗
PubMed1982

[Simultaneous measurement of radioactivity of 45Ca and 32P in tissues using a liquid scintillator and gas-discharge counter with a filter].

Optimal conditions are developed for two methods of simultaneous recording of 45Ca and 32P-radiation in the bone and other tissues. Both methods are compared from the standpoint of their efficiency. The calculation method for the 32P hard beta-radiation in the presence of 45Ca in one tissue specimen by the liquid scintillation counter is 5-10 times as efficient as that by the gas-discharge counter with the filter. The method for recording the low-energy 45Ca beta-radiation in the combination with 32P in one tissue specimen by the end-window gas-discharge counter and filter is more efficient to some extent that the calculation in the liquid scintillation counter.

Carbon Radioisotopes↗
PubMed1979

[Effect of UV-light on the structure of soluble deoxyribonucleoprotein-200 A].

The effects of UV-light (253,7 nm) on the structure of DNP and its protein and nucleic components were studied. The formation of protein-DNA covalent bonds in DNP-200 A at low ionic strength was confirmed. Under certain irradiation conditions more than 80% of protein may be linked to the DNA; all histone fractions were linked to the same extent and at the same rates. The local denaturation of DNA in the region of photo-induced thymine-thymine dimers and other photoadducts dramatically changed the rate and specificity of the effects of staphylococcal nuclease, which directly affected the composition and size of the fragments formed. A possible application of UV-irradiated DNP for various structural investigations is discussed.

Animals↗
PubMed1978

[Reaction between tetranitromethane and deoxyribonucleoproteins].

A comparative kinetic study has been made of tetranitromethane nitration of tyrosine residues in deoxyribonucleoprotein preparation (DNP) treated with EDTA and/or UV light at lambda=253.7 nm, as well as obtained by enzymatic digestion of nucleosomes. UV-light-induced protein-DNA linkages stabilize the structure of the preparation, whereas the action of chelate agents causes DNP-200 angstrom leads to DNP-100 angstrom transfer. Comparison of kinetic data and the results of the amino acid analysis of individual fractions of nitrated histones allowed to conclude that the differences observed between the degree and the rate of nitration are due to internucleosomic interactions which form the supernucleosomic structure of DNP.

Chemical Phenomena↗
PubMedDate not supplied

[Effect of chitosan on the electrophoretic motility of thymocytes].

An increase of contact interaction between macrophages and thymocytes in the presence of polysaccharide chitosan was suggested to be due to the change of surface charge of interacting cells. It was found that incubation of thymocytes in the presence of chitosan leads to the change of their charge in the positive direction. The measurement of electrophoretic mobility of the cells was carried out on " Parmoquant 2" (Carl Zeiss Jena, DDR). The change of electrophoretic mobility increases with decrease of pH, increase of chitosan concentration and decrease of the cell concentration in the medium. This phenomenon is probably due to absorption of positively charged molecules of chitosan on negatively charged cell surface.

Animals↗