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Biomedical subjects

Mária Dusinská

Publications and source records attributed to Mária Dusinská.

10 recordsLinked to original sources
PubMed2006

The relationship between micronuclei in human lymphocytes and selected micronutrients in vegetarians and non-vegetarians.

A vegetarian diet results in higher intake of vitamins and micronutrients, which - although providing antioxidant defence - may lead to deficiency in other micronutrients involved in DNA metabolism and stability (such as vitamins belonging to the B group). The principal difference among various vegetarian diets is the extent to which animal products are avoided. We have performed a pilot study to determine the relationship between the micronucleus frequency in lymphocytes and diet, and we compared the levels of Vitamins C and E, beta-carotene, B(12), folic acid, homocysteine and total antioxidant capacity in healthy vegetarians and non-vegetarians. The vegetarian group, consisting of 24 volunteers (13 women and 11 men), were matched for age and sex with 24 volunteers (12 women and 12 men) with a traditional dietary habit. Among the vegetarians were 13 lacto-ovo-vegetarians with average duration of vegetarian diet 10.8 years (ranging from 5 to 26 years) and 11 lacto-vegetarians with average duration of vegetarian diet 8.2 years (ranging from 3 to 15 years). Homocysteine, Vitamins C and E and beta-carotene levels in plasma were assayed by HPLC, and serum folate and Vitamin B(12) were determined with Elecsys Immunoassay tests. The total antioxidant capacity of plasma was estimated by measuring the ferric-reducing activity in a spectrophotometric assay. Micronuclei were measured in cytokinesis-blocked lymphocytes. Vegetarians had significantly higher levels of Vitamin C and beta-carotene (but not Vitamin E) in plasma compared with non-vegetarians (P<0.001). There were no significant differences in serum levels of folic acid and Vitamin B(12) between the monitored groups. Levels of folic acid in vegetarians correlated with length of vegetarianism (r=0.62, P=0.001, N=24). Vegetarians had elevated levels of homocysteine compared with non-vegetarians (P=0.007), as did vegetarian women compared with non-vegetarian women (P=0.031). We did not find any differences in total antioxidant capacity or in micronucleus frequency between the groups. Micronuclei correlated with age (r=0.62, P<0.001, N=48), women having higher frequencies than men. Multifactorial regression analysis showed significant effects of age, sex and total antioxidant capacity on micronucleus frequency (N=48, P<0.001).

Adult↗
PubMed2006

Possible involvement of XPA in repair of oxidative DNA damage deduced from analysis of damage, repair and genotype in a human population study.

Participants in a study of occupational exposure to mineral fibres in Slovakia were analysed for the polymorphism 23A-->G in the DNA repair gene XPA. Of the 388 subjects, 239 were exposed to asbestos, stonewool or glass fibre; the rest were unexposed controls. Levels of DNA base alterations (oxidation and alkylation) in lymphocytes were measured using the comet assay with lesion-specific endonucleases. 8-oxoguanine DNA glycosylase (OGG1) DNA repair activity was measured, as incision activity of a lymphocyte extract on DNA containing the OGG1 substrate 8-oxoguanine. Presence of the A allele was associated with higher levels of DNA damage (sites sensitive to formamidopyrimidine DNA glycosylase, endonuclease III or 3-methyladenine DNA glycosylase II) as well as with higher activity of OGG1 repair enzyme. DNA base damage increased with age, showing highly significant correlations when the whole population or subgroups of the population were analysed. OGG1 repair activity also increased with age, but when analysed according to XPA genotype, the increase was observed only in those individuals with an A allele. Although XPA is known as a protein involved in nucleotide excision repair of UV-induced damage and bulky DNA adducts, it may also have a role in the repair of oxidized bases.

Age Factors↗
PubMed2006

Importance of diet in protection against oxidative damage.

OBJECTIVES: In humans, epidemiological evidence suggests that increased consumption of fruits and vegetables can substantially enhance the protection against many common types of cancer. METHODS & RESULTS: A molecular epidemiological study in 3 Slovak factories producing asbestos, glass fibres and rockwool was conducted. Altogether 388 subjects (239 exposed, 148 controls) were investigated. Food frequency questionnaire was used to ascertain nutrient intake and compared to plasma levels of selected micronutrients, as well as to markers of oxidative stress (MDA, oxidative DNA damage and DNA repair) and antioxidant protection. We found a negative correlation between MDA concentrations and consumption of fruits (p=0.05) and vegetables (p=0.05) in all control subjects. Intake of fruits (p=0.05), vegetables (p=0.01), milk (p=0.01) and cereals (p=0.05) inversely correlated with oxidative DNA damage (net FPG) in all subjects investigated. There was a negative correlation between the intake of fruits (p=0.05) and vegetables (p=0.01) in all exposed subjects. CONCLUSIONS: Our results suggest that well balanced food consumption with higher fruits and vegetables intake has a protective effect against oxidative damage.

Adult↗
PubMed2005

Immunological monitoring in workers occupationally exposed to asbestos.

Occupational exposure to asbestos is strongly associated with pulmonary diseases, cancer and immunotoxic effects. Both systemic and local immunity may play an important role in the pathogenesis of these events. Immune cells appear to be influenced by asbestos exposure, either through direct effects or as a result of the host's protective response to exposure. In this study several immune system parameters were assessed in workers (n = 61) with at least 5 years' exposure to asbestos at an industrial plant. Workers exposed to asbestos fibres had significantly increased levels of immunoglobulin E and concentrations of interleukin-6 and -8 in comparison with two sets of controls (in-plant and town control groups). The levels of soluble adhesion molecule ICAM-1 were higher in the exposed group compared to the town control group. Significantly increased levels of IgA were found in asbestos-exposed group in comparison to the town control. Evaluation of the expression of adhesion molecules on lymphocytes, monocytes and granulocytes by flow cytometry showed significant increases in the class of selectins CD62L on monocytes and granulocytes. Moreover, significantly increased expression of markers CD69 and CD66b on eosinophils was found among workers exposed to asbestos. In conclusion, exposure to asbestos fibres was found to have several effects on immune system. Alterations of these immune parameters may indicate hypersensitivity (increased levels of IgE, increased expression of activation markers CD66b and CD69 on eosinophils) and an elevated inflammatory status (increased levels of interleukins--IL-6, IL-8) in exposed workers.

Adult↗
PubMed2004

Genotoxic effects of asbestos in humans.

Risks of carcinogenic and non-carcinogenic effects from asbestos continue owing to the persistence of the fibres in building materials and other products. For this reason, epidemiological and mechanistic research on the toxic effects of asbestos and mineral fibres is still needed. The present molecular epidemiological study was conducted in a former asbestos cement plant in Slovakia. Altogether 82 subjects were investigated, 61 exposed subjects (24 smokers and 37 non-smokers), and 21 factory controls (8 smokers and 13 non-smokers). Workers were exposed to asbestos for between 5 and 40 years. Though the exposure to asbestos during past 40 years was relatively high, at the time of sampling the concentrations of asbestos in the production hall exceeded the Slovak occupational limit (0.001 fibre/cm3) by a factor of only 3-5. The office area levels were below this limit. Biomarkers of exposure, effect and individual susceptibility were measured, including DNA damage (strand breaks [SBs], base oxidation and alkylation, using the comet assay); cytogenetic parameters; and individual DNA repair capacity (incision at 8-oxoguanine measured using a modified comet assay). Oxidised pyrimidines were significantly higher in exposed men compared with non-exposed (P = 0.04). There was also a positive association between SBs (P = 0.04) and age, and alkylation damage to DNA (P = 0.04) and age. Moreover, oxidised pyrimidines (P = 0.01) and alkylated bases (P = 0.001) strongly correlated with years of occupational exposure. Micronucleus frequency did not differ between exposed and control subjects. Repair capacity overall did not show any effect of exposure, though female controls had higher incision rates than did female exposed subjects. However, exposed asbestos workers had significantly higher numbers of chromosomal aberrations (P = 0.01) compared with control group. This finding is consistent with the known association of chromosome aberrations with cancer-risk.

Asbestos↗
PubMed2004

Does occupational exposure to mineral fibres cause DNA or chromosome damage?

Markers of genetic stability were monitored in lymphocytes from 98 workers employed in rockwool manufacture in a factory in the Slovak Republic, and 43 controls (administrative employees in the same factory). Strand breaks in lymphocyte DNA were higher in exposed compared to control non-smokers, but there was no effect of exposure on specific damage to bases in DNA, nor on chromosome aberrations. The frequency of micronuclei was higher in women in the control group than in rockwool-exposed women. DNA repair (8-oxoguanine DNA glycosylase activity) was unaffected by exposure, but was negatively correlated with micronucleus frequency, implying that unrepaired 8-oxoguanine contributes to micronucleus formation. The conclusion from this study is that, overall, rockwool exposure has no deleterious effect on genetic stability in humans.

DNA↗
PubMed2004

Seasonal changes in markers of oxidative damage to lipids and DNA; correlations with seasonal variation in diet.

We have addressed the question whether the relatively high incidence of cardiovascular disease and certain cancers in countries of central/eastern Europe might be associated with nutritional imbalance, in particular a lack of fresh fruit and vegetables in the diet in winter months. Nutritional parameters and markers of oxidative stress were studied in three Slovak population groups: 46 survivors of myocardial infarction (MI group) and 48 healthy, normolipidemic subjects (NL), living in or near Bratislava; and 70 rural controls (RC group) living a more traditional life style in a country town. Data were collected in February/March and September/October of two consecutive years, representing times of minimum and maximum local availability of fresh fruits and vegetables. Oxidative stress was monitored using two biomarkers; plasma malondialdehyde (MDA, a product of lipid peroxidation), and oxidation of lymphocyte DNA. Dietary antioxidants, folic acid, homocysteine, total antioxidant status (FRAP) and uric acid were measured in plasma. Food frequency questionnaires were administered. Vegetable consumption in summer/autumn was twice as high as in winter/spring. DNA damage did not vary consistently across the seasons. Mean plasma MDA levels for the MI and NL groups showed a clear pattern, with high levels in winter/spring and low levels in summer/autumn. Folic acid showed a reciprocal pattern, similar to the pattern of vegetable consumption. The RC group had the smallest seasonal variations in vegetable consumption, folic acid levels, and MDA. High winter MDA levels are seen in those individuals with relatively low folic acid; they never occur in subjects with high plasma folic acid, implying that folic acid might directly protect against lipid oxidation. This study illustrates the value of the molecular epidemiological approach, while emphasising the need for well characterised population groups and valid biomarkers.

Antioxidants↗
PubMed2004

Does a vegetarian diet influence genomic stability?

BACKGROUND: The vegetarian lifestyle is supposedly healthy, and differences between vegetarians and non-vegetarians in biomarkers related to diseases such as cancer might be expected. AIM OF THE STUDY: To investigate the possible role of different diets in maintaining genomic stability. METHODS: The vegetarian group, consisting of 24 volunteers (13 women and 11 men), were matched for age and sex with 24 volunteers (12 women and 12 men) with a traditional dietary habit. Among vegetarians there were 13 lacto-ovo-vegetarians (8 women, 5 men) with average length of vegetarian diet 10.8 years (ranging from 5 to 26) and 11 lacto-vegetarians (5 women, 6 men) with average length of vegetarian diet 8.2 years (ranging from 3 to15). All volunteers were nonsmokers, non-consumers of alcohol and had similar education and patterns of physical activity. Chromosome aberrations, micronuclei and DNA damage (strand breaks, oxidised bases and H(2)O(2)-sensitivity) were examined in peripheral blood lymphocytes of vegetarians and non-vegetarians. Plasma antioxidant status was assessed with the FRAP assay. RESULTS: We did not find any differences in percentage of cells with chromosome aberrations or in the frequency of micronuclei between vegetarians and non-vegetarians or between lacto-ovo and lacto-vegetarians. There was no statistically significant difference in total antioxidant capacity between the groups. The group with traditional dietary habits had significantly higher levels of oxidative DNA damage (strand breaks and oxidised purines, P = 0.005) compared with vegetarians. A significant positive correlation between age and oxidative DNA damage (net FPG-sensitive sites) was found in non-vegetarians, while there was an opposite trend towards a negative association in vegetarians. On the other hand chromosome aberrations correlated with age in vegetarians (r = 0.48, P = 0.017) but not in non-vegetarians. CONCLUSIONS: Our results indicate that a vegetarian diet can lead to a slight decrease in oxidative DNA damage in lymphocytes, but other markers of genetic stability are not affected. The lowest level of DNA damage was found in lymphocytes of lactovegetarians, (especially oxidised pyrimidines, P = 0.0017), suggesting that this diet provides some protection against oxidative stress.

Adult↗
PubMed2004

DNA damage and repair measured in different genomic regions using the comet assay with fluorescent in situ hybridization.

The comet assay is a sensitive method for measuring DNA strand breaks in eukaryotic cells. After embedding in agarose, cells are lysed and electrophoresed at high pH. DNA loops containing breaks (in which supercoiling is relaxed) escape from the nucleoid comet head to form a tail. Oligonucleotide probes were designed for 5' and 3' regions of the genes for dihydrofolate reductase (DHFR) and O6-methylguanine DNA methyltransferase (MGMT), both from the Chinese hamster, and the human tumour suppressor p53 gene. Alternate ends were labelled with either biotin or fluorescein. These probes were hybridized to the DNA of comets from Chinese hamster ovary (CHO) cells or human lymphocytes treated with H2O2 or photosensitizer plus light to induce oxidative damage. Amplification with Texas red- and fluorescein-tagged antibodies led, in the case of p53 in human cells, to red and green signals located in the comet tail (as well as in the head), indicating the presence of breaks in the vicinity of the gene. However, only one end of the MGMT gene appeared in the tail and almost no signals from the DHFR gene, either red or green, were in the tail of comets from CHO cells. Restriction on movement from the head to tail may result from the presence of a 'matrix-associated region' in the gene. The kinetics of repair of oxidative damage were followed; strand breaks in the p53 gene were repaired more rapidly than total DNA. Thus, fluorescent in situ hybridization in combination with the comet assay provides a powerful method for studying repair of specific genes in relation to chromatin structure.

Animals↗