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Biomedical subjects

L A Gromova

Publications and source records attributed to L A Gromova.

11 recordsLinked to original sources
PubMed1991

Chronobiological analysis of peripheral lymphocyte dehydrogenase activities in rats with Walker 256 carcinosarcoma.

Alpha-glycerophosphate dehydrogenase (alpha-GPD) and succinate dehydrogenase (SD) activities were investigated in lymphocytes from peripheral blood of normal rats and rats bearing the Walker 256 carcinosarcoma. Computer analysis using an original algorithm revealed a hierarchy of biorhythmic patterns of dehydrogenase activities. In all rats, mean SD activity was higher than mean alpha-GPD activity. In rats without tumor, SD and alpha-GPD activities were both higher than in rats with the Walker tumor. Biorhythm spectra for both dehydrogenases were very similar in rats with or without tumor, but tumor implantation resulted in a change of the phase relationship between alpha-GPD and SD.

Animals↗
PubMed1990

[A chronobiological analysis of the lymphocyte dehydrogenase activity in the peripheral blood of rats with Walker 256 carcinosarcoma].

In a series of experiments the alpha-glycerophosphate dehydrogenase and succinate dehydrogenase (SDH) activities were daily determined simultaneously by the cytochemical method in peripheral blood lymphocytes of normal rats and those with the Walker carcinosarcoma. Using an original algorithm a hierarchy of biorhythms was singled out by a computer according to individual changes in the dehydrogenase activity for each rat. The mean level of succinate dehydrogenase activity was higher than that of alpha-glycerophosphate dehydrogenase. A set of discovered biorhythms and their representation were identical in the both enzymes. The tumor transplantation caused changes in the phase coordination of investigated dehydrogenases in all rhythms and promoted an increase of the succinate dehydrogenase amplitude as compared with the alpha-glycerophosphate dehydrogenase amplitude in certain rhythms. It is concluded that biorhythmological parameters of these enzymes may be used for characterization of the tumor-bearing host.

Animals↗
PubMed1989

[Biorhythm study of the alpha-glycerophosphate dehydrogenase activity of the peripheral blood lymphocytes in rats with Walker carcinosarcoma].

In the series of experiments alpha-glycerophosphate dehydrogenase activity was daily determined at the same time by cytochemical method in the peripheral lymphocyte of normal rats and those with Walker carcinosarcoma. Using an original algorithm a hierarchy of biorhythms was singled out on a computer according to the individual changes in alpha-glycerophosphate dehydrogenase activity in each rat. It was shown that tumor development resulted in the reduction of the mean level of alpha-glycerophosphate dehydrogenase activity and considerable changes in diverse rhythms. Particular attention is paid to the phase changes, which can reveal changes in phase coordination of glycerophosphate shuttle cycle components.

Animals↗
PubMed1976

[Changes in the surface structures of bacteria as a cause of weak immunogenicity of vaccines from several strains of Citrobacter].

The authors present the results of studying the weakly immunogenic Citrobacter strains; some O-antigens of Citrobacter (11, 14, 19, 21a, 21b, 26) caused in immunization of rabbits a weak immune response (antibody titre--1:400-1:800). An electron microscopic study of the vaccines (obtained from these strains) and their fragments showed that a partial desquamation and denaturing of the antigenic material occurred in the process of preparation of heated vaccines. Formalin-treated vaccine subjected to preliminary deflaggelation for 2 min at 3000 cps was used for obtaining the O-sera against the mentioned antigens.

Agglutination Tests↗
PubMedDate not supplied

[Effect of ionizing radiation on the structural and ultrastructural organization of Mycobacterium rubrum].

The structural and ultrastructural organization of Mycobacterium rubrum cells was studied in the course of normal growth and in the conditions of irradiation. The cytomorphological differentiation of the bacterial membrane structure was shown as well as their functional role. Ionizing radiation was used as a tool for revealing the role of the membrane structures; the latter were found to be related to a certain cellular function. Damages of various, individually functioning membrane systems upon the action of ionizing radiation on the cell are described. Mesosomes are absent from the cells if the synthesis of peptidoglycan is inhibited, whereas hypersynthesis of the cell wall material is observed upon their hypertrophy. The content of mitochondrial analogs in the cell increases with the rate of metabolic processes. The function of cellular division is disturbed as a result of damages in the nucleoid DNA structure and degradation of nucleoidosomes. Changes in carbohydrate and lipid metabolism are also observed.

Cell Membrane↗
PubMedDate not supplied

[Spheroplast study of Thiobacillus ferrooxidans].

Spheroplasts were prepared, under the action of lysozyme (200 and 400 mcg/ml) from the cells of Thiobacillus ferrooxidans grown on the Waksman medium with elementary sulfur after their treatment with 0.5M NaCl solutions and exact exposure to sucrose (0.5M). Intracellular structures were revealed on the spheroplasts which could not be detected on intact cells.

Microscopy, Electron↗
PubMedDate not supplied

[The effect of biologically active compounds on the enzymatic activity of sarcoplasmic reticulum (Ca2+,Mg2+)-dependent ATPase transformed by synthetic phospholipids].

Aminasine, BeSO4 and Pt-5-sulfomercaptoquinolinate action on Ca-ATPase of SR showed a considerably less inhibiting effect as compared with that produced on the native membranes. The inhibiting action of the chemical compounds on those of native SR membranes is followed by the increase of mobility of hydrophobic segments of the membrane. The kinetic study of ATPase reaction at various temperatures showed on low-temperature transformation after the action by chemical compounds. Both structural transformations retain in the modified SR membrane independent of the chemical treatment. The activation energies considerably differ from those of native an modified membranes without chemical treatment (particularly in the region of 10-20 degrees). The data obtained allow to suggest that the inhibiting action of chemical compounds is followed by the changes in microviscosity (in the region of protein-lipid interaction of SR membrane, in particular), which by conformation transformations affect the configuration of the enzyme active center, alternating its geometry and catalytic activity.

Animals↗
PubMedDate not supplied

[Thiobacillus ferrooxidans pili].

The surface structures of Thiobacillus ferrooxidans were studied. When growing on a medium containing elemental sulphur, the cells possess peritrichously located filaments (piles) whose diameter varies from 4.5 to 7.0 nm and length, from 0.7 to 3.0 mcm. The cells of T. ferrooxidans do not have piles on a medium with ferrous iron. The physiological role of these structures for thiobacilli is discussed.

Ferrous Compounds↗
PubMedDate not supplied

[Identification and distribution of sulfur in Thiobacillus ferrooxidans cells].

Sulfur localization was studied in Thiobacillus ferrooxidans cells grown in the medium 9K containing elemental sulfur. When sulfur is oxidized to sulfuric acid, it is located on the surface of the cell wall and within the cell wall at different levels of the periplasmic space, as well as in large spherical structures arranged at the poles or in the center of the cell. The authors discuss the mechanism of sulfur transport and distribution in T. ferrooxidans cells when sulfur is oxidized to sulfuric acid.

Cell Wall↗
PubMedDate not supplied

[Nature of the sulfur-containing component and its function in Thiobacillus ferrooxidans].

As was shown using various reagents (Ag+, Cd2+) and solvents (ethanol, methanol), Thiobacillus ferrooxidans cells accumulate colloidal sulfur when they grow in the medium 9K containing elemental sulfur. Colloidal sulfur is accumulated in the periplasmic space, in large, bipolarly arranged spherical structures and in simple invaginates of the cytoplasmic membrane. T. ferrooxidans cells accumulate the sulfur at a highest rate during the stationary phase of growth and can use it as a source of energy under the conditions of starvation. The factors causing sulfur accumulation in T. ferrooxidans cells are discussed.

Cell Wall↗