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Biomedical subjects

L Viktora

Publications and source records attributed to L Viktora.

At least 19 recordsLinked to original sources
PubMed1989

Dual effect of calcium on erythrocyte membrane contraction.

Effect of different calcium concentrations on erythrocyte ghost shape and size has been studied. Erythrocyte ghosts are smallest at approximately 10 microM of total calcium content and in the absence of EDTA; both decrease and increase of free Ca2+ results in expansion of ghosts. Changes in erythrocyte ghost size occur at equal Ca2+ concentrations which, as it has been already found, alter ATPase activity of contractile membrane protein. The possibility is discussed that under physiologic conditions contractile membrane protein causes weak membrane contraction which differs from aphysiologic membrane shrinkage brought about particularly by cross-bridges at high Ca2+ concentrations.

Adenosine Triphosphate↗
PubMed1979

Cultivation of frozen mouse bone marrow cells in agar.

The authors attempted to cultivate frozen mouse bone marrow cells in a semisolid medium. They demonstrated that the stem haematopoietic cells of frozen mouse bone marrow were capable of proliferation and of colony formation on agar. The much smaller number of colonies from frozen mouse bone marrow (about 80% fewer) compared with fresh marrow is evidence that part of the stem haematopoietic cell population retains proliferative capacity even after freezing.

Agar↗
PubMed1979

Changes in hemopoiesis of mice of the C3H strain following transplantation of Gardner lymphosarcoma and infection with LDH-virus. I. Circulating blood.

The values of red and white blood count, of spleen and liver weight were determined in mice of the C3H strain after transplantation of Gardner solid lymphosarcoma contaminated with LDH-virus and after infection of LDH-virus, and compared with those found in normal intact mice. Special attention was devoted to early post-transplantation period and the final stage of tumor growth. The second day after infection of mice with LDH-virus, leukopenia with marked lymphopenia was observed, together with a reduced number of reticulocytes and spleen enlargement. The same changes became more pronounced in tumorous mice on the second posttransplantation day. The changes--with the exception of spleen enlargement--following LDH-virus infection became normalized within the period of the final stage of tumor growth. Contrarily, in mice with tumors in the final stage of the disease besides spleen enlargement also the reduced erythrocyte counts, leukopenia with pronounced lymphopenia and thrombocytopenia were found.

Animals↗
PubMed1978

Cultivation of fresh and frozen mouse bone marrow. - Application of methyl cellulose.

The culture of cells of both fresh and frozen mouse bone marrow on methyl cellulose (MC) was approached. We used 1.5%-concentration of MC and proved the stem cells of fresh and frozen mouse bone marrow to proliferate and form haemopoietic colonies on MC. We established that the freezing process did not significantly decrease the proliferative capacity of CFU-C stem cells.

Animals↗
PubMed1977

The change of erythrocyte shape following action of different substances altering mg++-dependent ATPase activity (actomyosin-like protein).

It was found that some substances as aspartate, glutamate, atropine, physostigmine, ephedrine, caffeine and theophylline tended to alter the erythrocyte shape in the same concentration in which also the Mg++-dependent ATPase activity had been changed. The employment of various concentrations of barbiturate revealed that changes of the erythrocyte shape were dependent on its concentration. In the present study the relationship between Mg++-dependent ATPase and biconcave erythrocyte shape is discussed.

Adenosine Triphosphatases↗