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Biomedical subjects

H Konecná

Publications and source records attributed to H Konecná.

At least 19 recordsLinked to original sources
PubMed1994

Adaptive response to ionizing radiation in normal and aneuploid human lymphocytes.

The ability to induce an adaptive response by low doses of gamma rays was studied in normal and trisomic lymphocytes (47, XX or XY, +21). The results indicate the presence of an adaptive response in lymphocytes of 3 normal donors, but in lymphocytes of 5 donors with trisomy 21 no significant adaptive response after irradiation with a low dose of gamma rays was found. There was similar chromosomal radiosensitivity in normal and trisomic lymphocytes (47, XX or XY, +21) irradiated with 1.50 Gy at the 48th hour after stimulation.

Cells, Cultured↗
PubMed1993

[Prenatal cytogenetic diagnosis in older pregnant women].

The paper deals with the genetic risk of advanced age of women assessed on the basis of prenatal cytogenetic analysis during the second trimester of gestation. The examined group comprised 614 pregnant women older than 35 years. The cells for chromosomal analysis were obtained by transabdominal amniocentesis during the 16th to 18th week of gestation. Cytogenetic examination revealed that the general risk of an aneuploid foetus in women of more advanced age is 2.12% and the most frequently encountered chromosomal aberration was trisomy 21 which was confirmed in 1.30 cytogenetically examined foetuses.

Adult↗
PubMed1991

Cytogenetic analysis of peripheral blood lymphocytes in workers occupationally exposed to polychlorinated biphenyls.

The ability of polychlorinated biphenyls (PCBs) to induce chromosome aberrations and sister chromatid exchanges (SCE) in peripheral lymphocytes was studied in a group of workers occupationally exposed to PCBs during the production of the Czechoslovak PCB products Delor 103 and Delor 106. The effect of PCB exposure was compared between an exposed group (N = 32, 3.25 +/- 0.34% aberrant cells, AB.C.), control group 1 (N = 20, 1.30 +/- 0.29% AB.C.), and control group 2 (N = 20, 1.60 +/- 0.31% AB.C.). The length of PCB exposure over 10 yr increased the frequency of AB.C. in a group exposed for 11-15 yr to 3.40% (N = 5) and in a group exposed for 16-25 yr to 5.85% (N = 7) vs. an increase of 1.60% AB.C. in group C2 and of SCE to 12.6 +/- 0.9/cell vs. 6.9 +/- 0.7 SCE/cell in C2. The clastogenic activity observed in this group may be the result of a high PCB concentration in blood plasma (320 +/- 190 micrograms PCB/l), and it is probably related to its solubility in adipose tissue, when it may act as another mutagen and carcinogen biotransformation inducer.

Adipose Tissue↗
PubMed1990

[Relation of the occurrence of chromosome aberrations in human peripheral lymphocytes to the cell cycle].

Experimental results confirmed that the best period of cultivation of human peripheral lymphocytes for chromosomal analyses in subjects exposed to mutagens and carcinogens is 44-48 hours when the dividing lymphocytes are in the first cellular cycle. With prolongation of the cultivation period of lymphocytes the values of chromosomal aberrations decline because in subsequent cellular cycles their number declines as a result of mitotic deaths of cells which contain unstable types of aberrations.

Cell Cycle↗
PubMed1987

Dose-rate dependence of chromosome aberrations in human peripheral blood lymphocytes irradiated in vitro.

Dose response relationships were studied in dicentric chromosomes in human peripheral blood lymphocytes exposed in vitro to 60Co gamma-rays in accumulated doses from 0.10 to 4.0 Gy at dose rates 1.0, 0.1, 0.01, and 0.001 Gy/min. The coefficients for the linear, quadratic and linear-quadratic relationships were calculated by the fitting method of least squares. It was found that the linear-quadratic model y = aD + bD2 was most suitable for the dose rates used. The effect of dose rate was manifested in such a way that at accumulated dose of 2.0 Gy the frequency of dicentric chromosomes was decreased by more than 50% if the dose was applied in 33 h than when it was given in 2, 20 or 200 min.

Adult↗