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Biomedical subjects

J Michalska

Publications and source records attributed to J Michalska.

At least 19 recordsLinked to original sources

Immunoperoxidase detection of polycyclic aromatic hydrocarbon-DNA adducts in breast tissue sections.

Although the etiology of the majority of human breast cancers is unknown, environmental carcinogens are suspected to play a role. In this study, we investigated polycyclic aromatic hydrocarbon-DNA adducts in 78 breast cancer patients and benign breast disease patients with lifetime environmental exposure to polycyclic aromatic hydrocarbon (PAH) compounds. Adducts were detected in paraffin sections by immunoperoxidase method using polyclonal antiserum and were quantitated by the image-analyzing system. A significantly higher level of adducts was found in benign breast disease as compared to cancer patients (P < .001; Mann-Whitney U test). Neither smoking nor genetic polymorphisms in glutathione S-transferase and cytochrome P450 influenced the level of adducts. This exploratory study demonstrates the usefulness of the immunoperoxidase method to detect PAH-DNA adducts in stored breast tissue and suggests further research on a larger population, including patients from both high- and low-pollution environments.

Adult↗

Measurement of cytogenetic endpoints in women environmentally exposed to air pollution.

The levels of sister chromatid exchanges (SCE), high-frequency cells (HFC) and chromosomal aberrations (CA) were studied in lymphocytes of Silesian women environmentally exposed to ambient air pollutants. Inhabitants of a less polluted but similarly urbanized area, in a rural region of Poland, served as controls. The study population was selected to minimize the major confounding factors influencing SCE and CA. These factors include age, gender, smoking status, and occupation. All donors were 35-46 years old non-smoking City Hall clerks. The levels of all three biomarkers were significantly higher in the exposed group than in controls as analyzed by the Mann-Whitney U-test. No correlation was found between levels of CA and SCE. Additional possible confounders, such as passive smoking, ex-smoking and X-ray chest examination did not influence the levels of biomarkers. This study builds upon our previous research in a male population but better controls for confounders. Thus, the results reveal genetic damage resulting from low-dose but chronic environmental exposure.

Adult↗

Bleomycin sensitivity test in the exposed and reference human populations.

Sensitivity to bleomycin was investigated in lymphocytes collected from three groups of males: 30 occupationally exposed cokery workers, 38 environmentally exposed Silesian citizen and 35 rural inhabitants. The data were analyzed at both the individual and group levels. The first analysis has revealed a substantial interindividual variability in the level of generated breaks (breaks per cell, b/c). This variability was independent of the age of the donor, smoking habit and X-ray exposure as tested in the multiple regression model. The means per group for the occupationally and environmentally exposed persons were almost the same with the values of 0.674 and 0.639, respectively. These two groups differed significantly from the rural population (b/c=0.448, p<0.001 by MANOVA). The reproducibility of the assay was satisfying (p>0.49 by the Wilcoxon matched paired test) after omitting 7 out of 49 repeatedly sampled donors. Those persons exhibited extremely high b/c rates in the first sampling.

Adolescent↗

A molecular epidemiology study in women from Upper Silesia, Poland.

The present report is a follow-up to our previous molecular epidemiology studies on DNA damage in residents of the industrial region of Upper Silesia. The study was designed to focus on environmental exposure to airborne pollutants; other exposures or confounding factors (e.g. smoking status and age) were eliminated. A Silesian population consisting of 67 donors was compared to 72 inhabitants of a less polluted but similarly urbanized area, surrounded by a rural part of Poland. In both regions the donors were non-smoking females with similar age range, and occupation. Eight biomarkers including urinary mutagenicity and 1-hydroxypyrene, polycylic aromatic hydrocarbon PAH-DNA adducts in oral mucosa, sister chromatid exchanges (SCE), high frequency cells (HFC), chromosomal aberrations (CA), and sensitivity to bleomycin in lymphocytes as well as glutathione s-transferase (GSTM1)/cytochrome P4501A1 (CYP1A1) genotypes were evaluated in samples collected in summer and winter seasons. All the biomarkers of internal and biological doses of mutagens and their early biologic effects indicated statistically significant increases in the Silesian group when compared to the controls. Immunohistochemical quantitation of PAH-DNA adducts additionally revealed significant seasonal changes in the levels of adducts. No influence of susceptibility genotypes (GSTM1 and CYP1A1) on biomarker levels was observed.

Adult↗

[Hyperthyroidism and pregnancy].

DESIGN: The aim of our study was to describe a course of pregnancy, delivery and puerperal time in women hospitalized in our Clinic during their pregnancies because of hyperthyroidism. MATERIALS AND METHODS: Sixteen case reports (thirteen pregnant women) were retrospectively analysed. Our study embrace data from the recent ten years. RESULTS: In all cases pregnancies, deliveries and puerperal time proceeded without any serious complications. Infants were delivered in good condition and no congenital defects were reported. CONCLUSIONS: 1. A proper treatment of hyperthyroidism in a pregnant woman determines the correct course of pregnancy, delivery and puerperal time. 2. We have not found any congenital defects, hypotrophy cases and infants' death reports in our material. 3. Hyperthyroidism in pregnancy does not determine cesarean section as a way of delivery.

Female↗

[Hypothyroidism coexisting with pregnancy].

DESIGN: The aim of the study was to describe pregnancies, deliveries, and puerperal times, and to compare them with the reached scientific communications. MATERIAL AND METHODS: Four pregnancies in women with the hypothyroidism were described. All cases were taken from the group of twenty pregnancies (18 women) who were treated because of thyroid gland diseases in our clinic. RESULTS: We found that every infant was born in good condition, deliveries and childbeds were uncomplicated. CONCLUSIONS: Our notices are similar to new scientific communications, that hypothyroidism coexists with pregnancy much often then everybody, till now, suspected and infants have not so often congenital defects.

Adult↗

Sister chromatid exchanges and high-frequency cells in men environmentally and occupationally exposed to ambient air pollutants: an intergroup comparison with respect to seasonal changes and smoking habit.

Sister chromatid exchanges (SCE) and high-frequency cells (HFC) were measured in peripheral blood lymphocytes from men environmentally and occupationally exposed to a mixture of ambient air pollutants. The environmentally exposed individuals were inhabitants of the industrial region of Upper Silesia; those occupationally exposed were Silesian cokery or steel plant workers, while the control group consisted of rural region residents. A total of 147 males were enrolled in the study. Blood samples were collected in winter (February) and summer (September) seasons. Three major areas were investigated during the study: exposure-based dose dependency, seasonal changes, and influence of smoking habits on the SCE frequencies. The latter is frequently reported as a confounding factor in SCE analyses. In both winter and summer samples, statistically significant increases of SCE were observed in the environmentally and occupationally exposed groups compared to the controls (p < 0.001). The difference between both exposed groups was also significant (p < 0.001). An intergroup comparison was based on ANOVA after adjustment for smoking status. In all three groups of interest, a seasonal variation was found with higher levels in winter. However, in a part of the study in which each donor served as his own control, statistical differences were only found within the exposed groups. Control region inhabitants did not have significantly higher frequencies of SCE in winter, compared to summer samples. The impact of two major confounders, age of the donor and smoking habit, was investigated by multiple regression analysis. Smoking was a major factor influencing the level of SCE. Nevertheless, the effect was seen in winter samples only, which suggests an additive response and adds new information to this known effect.

Adolescent↗

Molecular and genetic damage in humans from environmental pollution in Poland.

Extreme environmental pollution such as that found in the highly industrialized Silesian region of Poland has been associated with increased risk of cancer and adverse reproductive outcomes. Among the most prevalent carcinogenic and mutagenic air pollutants in Silesia are the polycyclic aromatic hydrocarbons (PAH) which are largely produced by industrial and residential combustion of coal. Molecular epidemiology aims to prevent disease by using biological markers to identify risks well before clinical onset to allow effective intervention. Here, we use a battery of biological markers to measure molecular and genetic damage in peripheral blood samples from residents of Silesia and from persons living in a rural, less polluted area of Poland. The results show that their exposure to environmental pollution is associated with significant increases in carcinogen-DNA adducts (PAH-DNA and aromatic adducts), in sister chromatid exchange including high-frequency cells, and in chromosomal aberrations as well as a doubling in the frequency of ras oncogene overexpression. We found that aromatic adducts on DNA were significantly correlated with chromosomal mutation, providing us with a molecular link between environmental exposure and a genetic alteration relevant to cancer and reproductive risk.

Adult↗

A cytogenetic study of men environmentally and occupationally exposed to airborne pollutants.

The level of sister-chromatid exchanges (SCE), high-frequency cells (HFC), chromosomal aberrations (CA) as well as the proliferation rate index (PRI) were measured in peripheral blood lymphocytes from three groups of volunteers. The environmentally exposed donors were residents from the vicinity of a coke factory; the occupationally exposed persons were cokery workers, while rural region inhabitants served as a control group. Compared with the control group, statistically significant increases of SCE and HFC, as well as decreased cell kinetics (PRI) were observed for both occupationally and environmentally exposed groups. The effect was especially pronounced when only smokers were taken into account. A statistically significant increase of CA was observed in the environmentally exposed group when CA including gaps (CA + G) were evaluated. The proportion of HFC was found to be the most sensitive method to detect genetic effects on the tested human population. This study demonstrates the usefulness of all 4 biomarkers (SCE, HFC, CA and PRI) in monitoring populations exposed to ambient pollution and clearly indicates effects from residential as well as occupational exposure to industrial air pollutants.

Air Pollutants, Occupational↗

Mutagenic and clastogenic activity of direct-acting components from air pollutants of the Silesian industrial region.

Sequential elution solvent chromatography (SESC) developed by Farcasiu for characterization of coal liquids was used for the fractionation of benzene extracts of airborne particulate pollutants. Mutagenic and clastogenic activity of SESC fractions was determined by the Salmonella/microsome test and the assay for V79 cell chromosomal aberrations (CAs), respectively. Five out of 8 obtained fractions showed differentiated, direct and indirect mutagenic activity. Selected 'direct' fractions, examined by the rodent cell chromosome aberration test, also gave a clastogenic response that increased with prolonged treatment time. The SESC system combined with 2 biological assays, the Ames test and the CAs test, seems to be a useful method for examination of genotoxic components of environmental pollutants.

Air Pollutants↗

Chromosome aberrations induced by 9-aminoacridine derivatives.

The induction of chromosomal aberrations by 5 derivatives of nitro-9-aminoacridine in V79 Chinese hamster cells was observed. The clastogenic activity of the compounds tested depended on the position of the NO2 group in the acridine ring. The strongest clastogens were derivatives with NO2 in position 1. The remaining derivatives placed in decreasing order of clastogenic activity were: 3-nitro, 4-nitro and 2-nitro. In addition, 2-nitro and 3-nitro derivatives produced hyperdiploid/polyploid metaphases.

Aminacrine↗

Interspersion and transcription of repeated sequences of rat DNA.

Repetitive rat DNA reassociated to Cot=0.1 and deprived of "foldback" sequences showed close interspersion with unique sequences. As measured by electron microscopy, the average length of repetitive segments was about 600 +/- 400, and of unique segments 1800-3600 base pairs. Pyrimidine tracts over 80 nucleotides in length were found mainly in foldback and repetitive fractions. Oligo(dT) tracts, 20-30 bases in length prevailed in the DNA fraction reassociated to Cot=0.1. Repetitive and unique DNA fractions were annealed to Millipore filters and hybridized with hnRNA. Up to 1.6% of repetitive DNA reassociated to Cot=0.05 showed base complementarity with hnRNA, whereas the comparative figures for DNA reassociated to Cot=10 and for the unique fraction were 0.8% and 0.3% respectively. When hybridization of hnRNA was carried out in solution in vast DNA excess, no hybrid formation with repetitive sequences reassociated to Cot=0.1 was observed, although hybridization with DNA reassociated to Cot=10 was noticeable.

Base Sequence↗

Some features of DNA-tRNA hybrids in the rat.

1. Sequences complementary to rRNA in rat DNA amount to 0.04% which corresponds to about 300 rRNA genes per haploid genome. 2. Purified DNA-rRNA hybrids had a DNA: rRNA weight ratio of about 1.1:1. Their melting temperature estimated on hydroxyapatite column was 75-80 degrees C. In CsCl gradients hybrids banded at 1.728 g/cm3 as compared to 1.699 g/cm3 for bulk DNA. 3. Length distribution histogram of DNA-rRNA hybrid molecules visualized by electron microscopy revealed that most of them possessed a length of 0.2-0.5 mum which corresponds to 4 X 10(5)-1 X 10(6) daltons, i.e. 670-1600 nucleotide pairs. 4. DNA sequences complementary to rRNA are localized on the heavy shoulder of the main band at a CsCl density of 1.709 g/cm3, and in a DNA fraction which re-associates at a Cot=10(-1)-10(2).

Animals↗

Lack of genotoxic activity of metronidazole and P1 derivative in two eukaryotic tests.

Metronidazole [1-(2-hydroxyethyl)-2-methyl-5-nitroimidazole] and P1 derivative [1-(2-hydroxy-3-methoxypropyl)-2-methyl-4-nitroimidazole] were investigated for their genotoxic activity in two eukaryotic tests: mitotic recombination in yeast and micronucleus test in mice. Both compounds showed no genotoxicity in these eukaryotic assays contrary to their well-documented mutagenic activity in microbial short-term tests.

Animals↗