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Biomedical subjects

M Pospísil

Publications and source records attributed to M Pospísil.

At least 145 records · Page 8Linked to original sources
PubMed1980

Inhibition of bone marrow cell proliferation and DNA replication induced by chloramphenicol.

The effect of CAP on proliferations of bone marow cells from unirradiated and irradiated (4.78 Gy) C57BL/10 mice was investigated by 3H-dTh incorporation into DNA of individual cells using autoradiography. CAP was administered from day 7 to day 10 after irradiation. CAP decreases the rate of entry of cells into S phase and the rate of 3H-dTh incorporation into DNA during replication. Cells of the erythropoietic series are mainly involved in this decrease. CAP has roughly the same inhibitory effect on unirradiated and irradiated cell populations.

Animals↗
PubMed1979

[Vitamin C levels in the early postnatal period in calves and their mothers].

The dynamics of L-ascorbic acid was studied in 68 cows and 91 calves at an age from one to ten days in the period from November to April. The study was conducted in two maternal stocks in a supply area of a large-capacity calf-house located in the beet-growing region. L-ascorbic acid in the blood serum was determined accoring to King. The lowest average levels of L-ascorbic acid were found in February (cows 0.35 mg%, calves 1.02 mg%), and the highest in April (cows 1.00 mg%, calves 2.52 mg%). The level of L-ascorbic acid descended during ontogenesis from the value found at birth (6.72 mg%); the values of the first postpartal day are significantly higher in comparison with all the remainind observations. The results constituted a basis for a working hypothesis on the importance of colostrum as an exogenous source of L-ascorbic acid for calves.

Animals↗
PubMed1979

In vitro lymphocytes stimulation with scarlet fever toxin.

Rabbit peripheral blood, spleen and thymus lymphocytes were stimulated in vitro with scarlet fever toxin. The ultrastructure of stimulated blast cells was described; the morphological features of these cells are similar to those of T-lymphoblasts. 3H-thymidine incorporation into lymphocytes stimulated with ET or PHA was studied in correlation with blast formation. Some quantitative discrepancies between both parameters are discussed.

Animals↗
PubMed1979

The effect of preirradiation application of aspartic acid salts on hemopoietic recovery in X-irradiated mice.

The possibility of radioprotective action of K and Mg aspartate administered in tap water for ten days prior to X-irradiation was investigated in male mice of the strain C 57 Bl/10. In normal animals, thymus weight was found to be increased by 10-day treatment with K and Mg aspartate. The postirradiation regeneration of spleen weight and incorporation of radioactive iron into the spleen and femoral marrow following sublethal irradiation was favorably modified by the treatment used. Pretreatment of mice with K and Mg aspartate delays the onset of early deaths at irradiation with an absolutely lethal X-ray exposure and raises the percentage of surviving animals after nearly lethal exposures.

Animals↗
PubMed1979

The effect of postirradiation application of aspartic acid salts on hemopoietic recovery in sublethally X-irradiated mice.

The effect of aspartic acid salts, especially of K and Mg aspartates, on certain hematological changes in the peripheral blood and hemopoietic organs of sublethally X-irradiated male mice of the strain C57Bl/10 was investigated. Salts of aspartic acid were administered in tap water after irradiation. A favorable effect of aspartic acid salts on erythropoietic recovery and on regeneration of thymus weight was found during the first two weeks after irradiation.

Animals↗
PubMed1978

Effect of hyperthyroidism on haemopoietic stem cell kinetics in mice.

Changes in the pool of haemopoietic colony-forming units (CFUs) of bone marrow and spleen were studied in experiments with mice fed dried thyroid gland (TH) for 21 days, and during the 13 days that followed feeding. After HU treatment, the number of CFUs in DNA synthesis was estimated. As early as the second day of TH treatment, the pool of CFUs is gradually increased, leading to an increase in the total number of splenic and bone marrow CFUs persisting after TH treatment for the period examined. Simultaneously, the numbers of nucleated cells in the bone marrow and spleen are increased. During TH feeding and following its termination, the total number of erythrocytes and the haematocrit values did not change significantly, whereas an increased number of leucocytes was observed in the peripheral blood after TH treatment. Elevation of the proliferative activity of CFUs occurred early in the period of TH treatment, with the maximum attained by end of the first week of TH feeding. This suggests a rapid response of the haemopoietic stem cell compartment to the administration of TH hormones. The participation of humoral factors controlling CFUs compartments in the mechanism of the stimulatory effect of TH hormones on haemopoietic stem cells is discussed.

Animals↗
PubMed1978

Effect of immunosuppressive agents on the blastogenic response of mouse spleen T and B lymphocytes. I. Culture conditions and the evaluation system.

A microplate culture system has been standardized for blastic transformation of lymphocytes, using various mitogens more or less specific to T lymphocytes (concanavalin A, phytohaemagglutinin, erythrogenic toxin) or B lymphocytes (lipopolysaccharides and their lipids A, pokeweed mitogen). The mitogen-stimulated lymphocyte activation was examined by the use of the nucleolar test determining the state of nucleolar RNA synthesis by morphologic criteria. In this introductory paper to a series of papers analyzing the specificity of action of the various chemical and biological immunosuppressive agents on the blastogenic responses of T and B lymphocytes, optimal concentrations of cells and blastogenic substances and other parameters were tested, and the kinetics of transformation was investigated in detail.

Animals↗
PubMed1977

Surface immunoglobulins on stimulated lymphocytes.

The effect of phytohaemagglutinin, lipopolysaccharide, lipid A and streptococcal erythrogenic toxin on the expression of surface immunoglobulins on nerborn piglet spleen lymphocytes was studied, using iodinated anti-pig Ig, L-, mu- or gamma-antisera. It has been concluded that only IgM is the surface immunoglobulin on non-stimulated as well as LPS-stimulated piglet lymphoid cells. An increase in the numberof labelled cells was observed after cultivation of piglet spleen cells with all the mitogens tested.

Animals↗
PubMed1976

Feto-maternal relationship in normal pregnancy in mixed lymphocyte cultures.

In eight wife-husband pairs during the whole pregnancy the reactivity of lymphocytes to PHA, to lymphocytes of unrelated donor and to lymphocytes of husband was studied. No statistically significant differences were found in reactivity of wife's and husband's lymphocytes. In eleven women at delivery a statistically significant decline of MLC reaction to lymphocytes of own and unrelated newborn was found, while the reactivity to PHA and to lymphocytes of unrelated adult donor remained unchanged. Similarly, the lymphocytes of eleven newborn infants reacted statistical significantly less to lymphocytes of own mother and unrelated mother, while the reaction to PHA and to lymphocytes of unrelated donor was well expressed.

Cells, Cultured↗
PubMed1976

A radioprotective effect of calcium chloride in combination with cystamine, mexamine, and hypoxemic hypoxia in mice.

A mild protective effect of a solution of CaCl2 (3.21 g%) injected in a volume of 0.2 ml i.p. 30 minutes prior to irradiation was demonstrated in experiments with male mice in the strain C 57 B1/10. The pre-irradiation administration of CaCl2 increased the LD50/30 by approximately 60R as compared with control animals, to which an isoosmotic NaCl solution was injected. A more pronounced decrease of the post-irradiation mortality of the animals was reached by combined administration of CaCl2 with chemical protectors- cystamine or mexamine administered in relatively low s.c. doses, as well as by a combination of CaCl2 with the protective action of hypoxemic hypoxia. Under the conditions of combined protection, the administration of CaCl2 increased LD50/30 by approximately 100 to 130R. A higher rate of formation of endogenous spleen hematopoietic colonies was observed in the animals protected by calcium. Possible mechanisms of the radioprotective effect of calcium on the level of the hematopoietic stem cells are discussed.

Animals↗