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Biomedical subjects

I Kalina

Publications and source records attributed to I Kalina.

At least 55 records · Page 3Linked to original sources
PubMed1985

[Effect of cytosine arabinoside on the cell cycle and level of radiation-induced chromosome anomalies in lymphocytes of mammals].

A treatment by cytosine arabinoside (ara-C), an inhibitor of repair, and by deoxycytidine, which reverse the inhibition activity of ara-C, has been used to study the duration of repair in X-irradiated mammalian lymphocytes. In human the repair requires at least three hours but is already completed within two hours for rabbit lymphocytes. The results appear rather surprising for pig lymphocytes because addition of ara-C to culture medium does not modify apparently the yield of aberrations.

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PubMed1983

Effect of continuous irradiation on the thrombopoietic system in mice.

In this paper the changes of the megakaryocyte number of the spleen and those of thrombocyte number of the peripheral blood were studied during continuous irradiation with a dose rate of 9.57 to 957 mGy/day. Beginning with a dose rate of 95.7 mGy/day the thrombocyte number of the blood and the megakaryocyte number of the spleen of irradiated animals decreased significantly. Whereas the thrombocyte number remained permanently decreased, the cell number of the megakaryocyte type is increased temporarily to a clearly higher level as compared with the controls on the 100th day of irradiation approximately. This is especially true for the middle dose rate. During this time of irradiation nucleolar hyperchromatosis as well as pycnosis were observed in many megakaryocytes.

Animals↗
PubMed1982

DNA-synthesizing cells in the blood of rats exposed to X-radiation.

The quantitative changes in nucleic acids, 3H-thymidine incorporation and the colony-forming capacity of haemopoietic stem cells were followed in the blood of rats during 28 days after a single exposure to 5.5 Gy of X-radiation. The concentration of nucleic acids, especially that of DNA, decreased sharply already during the first day, falling to the minimum values by day 10 after irradiation. The RNA concentration recovered by day 21 and the DNA concentration by day 28. 3H-thymidine incorporation into DNA in the blood of the irradiated animals was increased, especially at 10-14 days. From the increased incorporation of the precursor into DNA after short-term (4h) labelling in vitro and without additional stimulation we judged that at that time the DNA-synthesizing cells occurred in increased numbers in the blood of the irradiated rats. Simultaneously we examined the colony-forming capacity of the blood (CFU-S) with an attempt to contribute to the elucidation of the function of DNA-synthesizing cells. The changes in colony-forming capacity proceeded in parallel to changes in 3H-thymidine incorporation, with a maximum number of CFU-S by day 14 after irradiation. The results suggest that DNA-synthesizing cells in the blood of the irradiated rats represent circulating haemopoietic stem CFU.

Animals↗
PubMed1982

Chromosome aberration persisting in cells of continuously irradiated mice.

Cytogenetical analysis of the bone marrow cells in mice irradiated continuously with the dose rate 0.478 Gy/day made within the course of various accumulated doses demonstrated the decrease in the number of chromosome aberrations till the post irradiation day 3 in all groups reaching about 75% on average. At further examination periods on day 10 and 30 the decrease in the aberrations appeared to be slower and was dependent on the magnitude of the accumulated dose. Increased number of the aberrant cells as compared with the controls was noted in the groups with the accumulated dose higher than 10 Gy and on the hundred postirradiation day, as well.

Animals↗
PubMed1982

Cytogenetical changes and their relation to survival of bone marrow hemopoietic cells during continuous irradiation.

In this paper the frequency of aberrant cells in the bone marrow of continuously irradiated mice with the dose rates 0.05 Gy/day and 0.50 Gy/day was studied. The aberrant cell values were found to be increased non-proportionally with the accumulated doses and their level was influenced mainly by the irradiation period in the dose range 0.5-5 Gy. The most significant reduction in the lymphocyte number and to some extent the granuloid cells number in the bone marrow occurred in the dose rate 0.50 Gy/day. The frequency of aberrant cells in the bone marrow increased at the same time to 15-20%. Possible mechanisms influencing the different response of cells to irradiation are discussed.

Animals↗
PubMed1982

A modification of the micronucleus test and its use for evaluating the cytogenetic changes after irradiation.

Foetal calf serum commonly used in the method of the micronucleus test was replaced with homologous mouse serum prepared in our laboratory. Using 0.2 ml of this serum per femur, the quality of the smears of bone marrow cells was comparable to that obtained by the original method. Long-term storage of mouse serum in frozen state (up to one year) did not affect the quality of the smears. Furthermore, we investigated the frequency of MN-PCE in the bone marrow of mice exposed to 1, 2.5, and 5 Gy of X-rays. The animals were examined at 3-h intervals from 6 to 48 h after irradiation. At 2.5 and 5 Gy, the frequency of MN-PCE reached the maximum values (about 7%) 27-39 h after irradiation. At 1 Gy, a marked increase in MN-PCE frequency occurred at 9-12 and 36-42 h after irradiation (about 3%, in both instances).

Animals↗
PubMed1980

Cytogenetic and genetic effects of continuous irradiation at a low exposure rate.

We followed the frequency of chromosome aberrations in bone marrow cells of mice continuously irradiated from a 60Co source at an exposure rate of 4.785 mGy/day (0.5R/day) for 140 days. The frequency of chromosome aberrations increased to 4.8% already at day 10 of irradiation and was stabilized at 2--3% in the period from 60 to 140 days. No increase in the frequency of reciprocal translocations and dominant lethal mutations induced in spermatogonia during irradiation was, however, observed.

Animals↗