PubMed Health⌕ Search

Biomedical subjects

I Kalina

Publications and source records attributed to I Kalina.

At least 37 records · Page 2Linked to original sources
PubMed1997

Variability of the adaptive response to low dose radiation in peripheral blood lymphocytes of twins and unrelated donors.

To assess the genetic control of the induction of the adaptive response after low-dose ionizing radiation, the frequencies of chromosome aberrations were evaluated in four pairs of monozygotic twins, two pairs of dizygotic twins, and in nine unrelated individuals. Stimulated cells were exposed to adaptive dose of 5 cGy gamma rays at 24 h and challenge dose of 150 cGy gamma rays at 42 h. Cells were fixed at 48 h and chromatid and isochromatid breaks were evaluated. The adaptive response was found in two pairs of monozygotic twins, but not in the two other pairs. Individual differences in adaptive response between the members of monozygotic twins were very small. In contrast, the variability in the adaptive response between the members of dizygotic twins was much greater and was similar to that observed in the unrelated donors. The results confirmed that heterogeneity in the adaptive response after exposure to low-dose gamma rays was controlled genetically to a considerable extent.

Cells, Cultured↗
PubMed1997

[Mutagenic effects of coal tar used in the treatment of psoriasis].

BACKGROUND: Pharmaceutic tar used in the treatment of psoriasis has a high contents of polycyclic aromatic carbohydrates which are considered to be carcinogenic. AIM: The study is aimed at the estimation of the genotoxic risk arising from the treatment of psoriatic patients by pharmaceutic tar. The estimation is performed by biomonitoring. METHODS: The used methods included: bacterial test on TA 98 strain of Salmonella typhimurium aimed at the assessment of mutagenity of urine and cytogenetic test aimed at the assessment of chromosomal aberrations in peripheral lymphocytes. RESULTS: The exposition of psoriatic patients to pharmaceutic tar significantly increased the index of mutagenity as an index of the presence of mutagen in urine, as well as the occurrence of chromosomal aberrations in peripheral lymphocytes. CONCLUSIONS: The results of monitoring have indicated that psoriatic patients treated by pharmaceutic tar are endangered by an increased genotoxic risk. (Tab. 2, Ref. 17.)

Adult↗
PubMed1996

The comet assay for the detection of genotoxic damage in the earthworms: a promising tool for assessing the biological hazards of polluted sites.

The comet assay, a relatively new method for DNA strand break detection in individual cells, is becoming a major tool for environmental biomonitoring. One approach for assessing the possible environmental consequences of hazardous waste pollution involves the assessment of genotoxic damage (and other effects) in sentinel organism. The single cell gel electrophoresis (SCGE) technique or comet assay. because of its simplicity, sensitivity, and need for only small numbers of cells, has been suggested as an ideal technique for such studies. An important advantage of the technique is that it is applicable to any eukaryotic organism and cell type. Verschaeve et al. (1993) conducted a pilot study using alkaline comet assay to assess the extent of DNA damage in coelomic leucocytes (coelomocytes) of earthworms (Eisenia foetida) maintained in different soil samples as an indicator of soil pollution. The aim of our study was to evaluate the usefulness of monitoring single strand breaks in coelomocytes for assessing genotoxicity of pollutants in coke oven area. We exposed earthworms to samples of soils obtained from polluted areas of a coke oven. All samples gave a significantly higher comet tail moment that those obtained from worms kept in laboratory conditions (standard black earth = internal controls) and worms kept in soils from control areas (= external controls). Our results show that the comet assay applied to earthworm is very valuable for monitoring and detection of genotoxic compounds in terrestrial ecosystems.

Animals↗
PubMed1995

The adaptive response of peripheral blood lymphocytes to low doses of mutagenic agents in patients with ataxia telangiectasia.

The inducible ability of adaptive response by low doses of gamma rays or bleomycin was studied in peripheral blood lymphocytes of healthy donors and in ataxia telangiectasia patients. An adaptive response was found in the lymphocytes of healthy donors pretreated with either gamma rays or bleomycin, however in individuals heterozygous for ataxia only bleomycin was effective. In the two ataxia telangiectasia homozygotes tested no adaptive response was found either after low-dose gamma rays or after bleomycin. The preliminary results indicate that the adaptive response might be influenced by various factors.

Adaptation, Physiological↗
PubMed1995

Induction of single strand DNA breaks in workers professionally exposed to polycyclic aromatic hydrocarbons.

An epidemiological study was performed on 42 workers from coke works with the aim to evaluate the usefulness of monitoring single strand DNA breaks (SSBs) in human lymphocytes to assess exposure to polycyclic aromatic hydrocarbons (PAHs) as well as the usefulness of SSBs induction as an indicator of biological effects of PAHs. SSBs can be readily quantitated by a simple fluorometric assay of DNA unwinding. Compared with the control group, statistically significant increase in SSBs was observed in coke oven workers occupationally exposed to PAHs. These findings are in agreement with previous results obtained by a different method of measuring DNA damage in subjects exposed to high PAH levels. The findings confirmed that SSBs determination in human lymphocytes reflected the exposure to PAHs and the FADU method appears to be useful in the revelation of effects of occupational exposure to industrial air pollutants such as PAHs.

Coke↗
PubMed1994

[Mutagenic activity of urine of patients with psoriasis treated with pharmaceutical black coal tar].

BACKGROUND: Examination of patients exposed for prolonged periods to black coal tar used in dermatology for the treatment of psoriasis revealed its carcinogenic effect. The objective of the present work was to assess the mutagenicity of urine samples from psoriatic patients treated with pharmaceutical black coal tar before treatment, and 14 and 28 days after application of the preparation. METHODS AND RESULTS: To a group of 19 patients with psoriasis vulgaris (12 men, mean age 43.3 +/- 3.96 years and 7 women, mean age 44.7 +/- 4.02 years) daily black coal tar in the form of Sack's tincture for a period of 28 days was applied to 10 - 80% of the body surface, i.e. 1000 - 13,000 cm2 of skin, amounting to 10 - 40 g. The mutagenic activity of urinary extracts was assessed by means of the Ames test on bacterial strain TA 98. It was revealed that urine samples from all patients exposed during the therapeutic procedure has a greater mutagenic activity, as compared with controls, whereby the mutagenicity index was higher in smokers (2.1) than in non-smoker patients (1.88) in the presence of the metabolic activating system. The elevated values of the mutagenicity index were recorder after the 14th day (2.25) and after the 28th day of treatment (2.07), as compared with controls (0.93); p < 0.05. Before the onset of treatment the mutagenicity index was 1.64. CONCLUSIONS: The assembled results confirm the view of an increased genotoxic risk in psoriatic patients treated with preparations containing black coal tar.

Adult↗
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↗
PubMed1994

[Prenatal cytogenetic diagnosis of trisomy 21 using amniotic fluid cells].

BACKGROUND: Trisomy 21 is the most frequent chromosomal disorder which is associated with advanced maternal age. OBJECTIVES: The aim of our work was to examine the risk of trisomy 21 occurrence in a group of pregnant women subdued to prenatal cytogenetic examination. METHODS: The examined group consisted of 1128 pregnant women. The cells for cytogenetic analysis were obtained by means of transabdominal amniocentesis during the second trimester of pregnancy. Cultivation of amniocytes lasted 15-20 days. The chromosomes were stained by a conventional and G-striping method. RESULTS: Cytogenetic analyses have indicated that the aberrant karyotype was present in 32 (2.82%) out of 1128 fetuses. In addition the results have confirmed that trisomy represented the most frequent chromosomal aberration (60%) detected by means of prenatal cytogenetic diagnostic examinations and the risk of its incidence increased exponentially in women who were older than 35 years of age. CONCLUSIONS: The prenatal cytogenetic diagnosis represents a significant role in the prevention of hereditary conditioned chromosomal disorders. (Tab. 1, Fig. 1, Ref, 13.)

Amniocentesis↗
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↗
PubMed1990

[Present possibilities and perspectives in genetic toxicology].

Information on the new branch of medical genetics--genotoxicology--is presented. The results obtained so far in the field of genotoxicologic research are briefly reviewed and the contribution of our departments is outlined. The conclusion indicates further trends in basic and applied research and emphasizes the necessity to take advantage of the knowledge and information achieved in genotoxicologic research in social practice.

Czechoslovakia↗
PubMed1989

Changes in cellularity, CFU-S number and chromosome aberrations in bone marrow and blood of rats after neutron and continuous gamma irradiation.

Changes in the hematopoietic bone marrow of rats were observed after single wholebody neutron dose of 2 Gy and combined single neutron (2 Gy) and continuous gamma (6 Gy, daily dose rate of 0.5742 Gy) irradiation. Neutron irradiation significantly reduces the number of karyocytes in the bone marrow including CFU-S and induces the extensive cytogenetic damage. The following continuous gamma irradiation does not intensify the primary damage, but maintains the CFU-S and cellularity values at a decreased level for the whole time of irradiation. Recovery of the damage begins only after the termination of continuous irradiation; its course is similar to that after single neutron irradiation. The influence of combined effect of neutrons and gamma rays is nevertheless manifested in later periods after the irradiation by reduction in the total CFU-S number in the bone marrow.

Animals↗
PubMed1987

Reciprocal translocations in germ cells of male mice receiving external gamma-irradiation.

Data reported in the literature up to 1985 on reciprocal translocation induction in male mouse germ cells by external gamma-ray doses ranging from 0.5 to 6.0 Gy delivered at fixed dose rates were analyzed. On the assumption of a non-threshold linear dose response, zero effect at zero dose, and a center of distribution lying on an approximately straight line, calculations were made of linear regression coefficients. These coefficients (b), as a function of the dose rate (P), were well fitted by two straight lines: b = (3.15 +/- 0.59 log P) X 10(-6) for dose rates from 0.01 to 0.1 mGy/min; and b = (7.52 +/- 3.86 log P) X 10(-6) for dose rates ranging from 0.06 to 1.2 X 10(3) mGy/min. The intersection point of these two lines determined the so-called threshold level of the dose rate, namely, 4.6 X 10(-2) mGy/min, at which the effectiveness of external gamma-irradiation is not expected to exceed 2.36 X 10(-6)/mGy. In addition, experiments were undertaken in which yields were recorded of reciprocal translocations in germ cells of male mice exposed to 0.9 Gy of gamma-radiation at dose rates ranging from 6.14 X 10(-3) to 6.14 X 10(2) mGy/min (6 levels); comparisons were made with data published up to 1985 from similar studies using other fixed doses. To do this, translocation yields were expressed as relative yields (F) and their relationship to the dose rate (P) for the individual fixed doses was represented by an equation of the type: F = alpha + beta log P. For most of the equations, the regression coefficients were in good agreement and a single relationship was obtained to represent them. From the analysis performed it follows that, within the 0.6-6.0 Gy dose range, the pattern of the F vs. P relationship is unaffected by the dose. This supports the initial assumption that for the dose range up to 6.0 Gy the dose response for the reciprocal translocation yield is a non-threshold straight-line relationship.

Animals↗
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↗