Assessment of cellular damage with cytome assay among environmental/occupational triazole

The use of triazole fungicides is common in Minas Gerais, Brazil. However, the risk arising from excessive and often unprotected exposure can be harmful to farmers. Therefore, we evaluated volunteers, exposed to triazole fungicides for cellular damage caused by this pesticide. In the buccal micronucleus cytome assay (BMCyt), cells were analyzed. Urinary triazoles were analyzed by the Liquid-Liquid Extraction coupled with Gas-chromatography/mass-spectrometry (LLE-GC/MS). Statistical differences were found for all cell types evaluated in residents of rural areas (n = 145). Analysis of variance showed statistical difference in kariolytic and pyknotic cells, between the groups of men and women living in rural areas, with higher incidence in the male group. Likewise, higher concentrations triazoles in urine samples in the male group were observed. Greater cellular damage suggests increases in DNA damage, chromossomal instability and cell deaths. The results showed the urgency of the public management with the implementation of measures to minimize the pesticides exposure.

Evaluation of genotoxic damage in buccal mucosa cytome assays in Iraqi school children exposed to air pollutants emanating from oil fields

Presently, over 135 thousand barrels of crude oil are extracted daily from the Al-ahdeb oil fields (situated at 180 km south east of Baghdad, Iraq). Millions of gallons of untreated toxic wastes, gas and crude oil are released into the environment. Oil mining mediated pollution may cause damage to humans and the environment. To investigate potential health risks for children living in this area, we recruited a sample of 6-8 year old school children residing within a 5 km radius around the oil field, and a control sample of children of the same age from a school 40 km away from the oil-field. Exfoliated buccal mucosa cells obtained from these children were analyzed applying the micronucleus (MN) cytome assay. Possible confounding variables such as x-rays performed during three weeks preceding sampling were obtained by a questionnaire. Nuclear anomalies were significantly elevated in children living near the oil-field. Micronucleated cells 1.3-fold, nuclear buds 3-folds, binucleated cells 3-folds, karyorrhetic cells 4-folds and karyolysis more than 10 folds with a significant difference (P < 0.05). Hence, children living in the proximity of Iraqi oil-fields are at elevated risk of genetic damage, which can cause detrimental health effects in the future.

"Normal values" for the lymphocyte cytokinesis-block micronucleus cytome parameters: Repeatability and reproducibility in a healthy reference population

The micronucleus test in peripheral blood lymphocytes is the most widely validated technique to evaluate the DNA damage and chromosomal instability in human populations. The test is largely applied in monitoring environmental and occupational exposure to genotoxic agents. It was also proposed as a biomarker of risk/susceptibility for cancer and other degenerative diseases. The availability of "normal values" in healthy populations is a main requisite for the assay application in human biomonitoring. Age and gender-related ranges of micronucleated binucleated cells (MNBN) baseline values were established in a group of 103 healthy platelet donors (50 males and 53 females) not recently exposed to genotoxic agents and characterized for demographic, lifestyle and dietary factors. Repeatability of the test by the same scorer was evaluated. Reproducibility was estimated through analysis of repeated blood samples. High correlation between the results of the three blood samplings in two separate scoring sessions of MNBN/1000BN (R² values were 0.83, 0.74 and 0.68; P < 0.0001) and PI values (R² values were 0.69, 0.62 and 0.65; P < 0.0001) was detected. High consistency among the values obtained in three different samplings in the same individual was observed (Intraclass Correlation Coefficient (ICC) = 0.905, (95% CI = 0.868-0.933, P < 0.0001) The range of "normal" values predicted on the basis of the results of the present study appears to be sufficiently narrow to warrant application of the assay in the comparison of data obtained from groups of exposed or susceptible subjects, supporting its use in preventive programs. The large inter-individual variability predicted by the model used in the present study hampers a clinical application of the assay at individual level. The method applied in the present study represents a generally applicable model to derive "normal values" in any population, as an essential step before starting a biomonitoring study.

Assessment of the health status and risk of genotoxic and cytotoxic damage in Argentinian adolescents living near horticultural crops

In some rural areas in Argentina, adolescents may be considered as a group indirectly exposed to agrochemicals because their parents plant small crops near their homes. This could become a health risk to children and adolescents who may be more sensitive to exposure to chemicals than adults. The objective of this study was to evaluate the health status of two different groups of Argentinian adolescents using biochemical parameters, dietary information, and cytogenetic biomarkers of genotoxicity and cytotoxicity. The study groups included 32 adolescents from Montecarlo, who were indirectly exposed to agrochemicals, and 30 unexposed adolescents from Exaltación de la Cruz. The values of total cholesterol, LDL cholesterol, triglycerides, gamma glutamyltransferase, and butyrylcholinesterase (BuChE) were higher (p < 0.05) in males from Exaltación de la Cruz compared with those from Montecarlo. The BuChE activity was also higher (p < 0.05) in females from this region. Furthermore, the consumption of citrus, vegetable-like fruits, tubers, and red meat was more frequent (p < 0.05) in Montecarlo. On the other hand, differences in frequency of biomarkers of genetic damage in lymphocytes were not found (p > 0.05). However, the cytome assay in buccal cells showed that karyorrhectic and pyknotic cells were more frequent (p < 0.05) in the Montecarlo group; whereas, the frequencies of cells with nuclear buds, condensed chromatin and karyolysis were higher (p < 0.05) in the Exaltación de la Cruz group. Despite the differences between the parameters and biomarkers evaluated, the adolescents of Montecarlo did not present health impairment probably due to the type and level of exposure to agrochemicals.

Cytokinesis-block micronucleus cytome assay parameters in peripheral blood lymphocytes of the general population: Contribution of age, sex, seasonal variations and lifestyle factors

The cytokinesis-block micronucleus cytome (CBMN Cyt) assay was used to evaluate the baseline frequency of cytogenetic damage in peripheral blood lymphocytes of the general population (average age, 38.28 ± 12.83 years) in relation to age, sex, body mass index, seasonal variations (season of sampling, period of sampling and different meteorological parameters) and lifestyle factors (smoking habit, alcohol consumption, exposure to medications and diagnostic radiation, physical activity, and family history of cancer). The background frequency of micronuclei (MNi) for the 200 subjects assayed was 5.06 ± 3.11 per 1000 binucleated cells, while the mean frequency of nucleoplasmic bridges (NPBs) was 1.21 ± 1.46 and of nuclear buds (NBUDs) 3.48 ± 2.14. The background frequency of apoptosis and necrosis was 1.58 ± 1.50 and 1.39 ± 1.56, respectively, while the mean nuclear division index (NDI) was 1.99 ± 0.14. The cut-off value, which corresponds to the 95th percentile of the distribution of 200 individual values, was 11 MNi, 4 NPBs and 7 NBUDs. The study also confirmed an association of the above mentioned parameters with age, sex and several lifestyle factors. Moreover, significant confounders based on our results are also sampling season, sampling period and different meteorological parameters that were dependent on the CBMN Cyt assay parameters. In line with the above mentioned, several factors should be taken into account when it comes to the monitoring of exposed populations using cytogenetic biomarkers. Moreover, the normal and cut-off values obtained in this study present background data for the general population, and can later serve as baseline values for further biomonitoring studies.

Assessment of exposure to pesticides in rural workers in southern of Minas Gerais, Brazil

The aim of the study was to assess of occupational exposure to pesticides in rural workers using genotoxicity test, bioindicators and clinical evaluation. Blood, urine and buccal samples from persons, rural workers exposed to a complex mixture of pesticides with organophosphates (n=94) and without organophosphates (n=94) were collected to compare the activities of cholinesterases, the levels of urinary dialkyl phosphates, genotoxicity data, from a cytome assay. Biomarkers were analysed by traditional/published methods Control group consisted of 50 other persons, non- occupationally exposed to pesticides from the city of Alfenas, Minas Gerais, Brazil. All subjects underwent a clinical evaluation. In the group exposed to organophosphates, the activity of acetylcholinesterase, butyrylcholinesterase and total cholinesterase was lower by 63.8%, 12.8%, and 14.8%, respectively, and 92.6% of the group had dialkyl phosphates present in their urine. The cytome assay was used to measure biomarkers of DNA damage (micronuclei and/or elimination of nuclear material by budding), cytokinetic defects (binucleated cells), and proliferative potential (basal cell) and/or cell death (condensed chromatin, karyorrhectic, pyknotic, and karyolytic cells). The group exposed to organophosphates showed significant changes in all these parameters compared to the control group and showed significant changes in budding, condensed chromatin and karyolytic cells compared with the group non-exposed to organophosphates. Data from the clinical evaluation showed significant changes in the central nervous, respiratory and auditory systems. The studied biomarkers are able to distinguish occupational and environmental exposure to pesticides and the data showed hazardous exposure to organophosphates and afforded valuable data to estimate the risk to cancer development.

Erythrocyte micronucleus cytome assay of 17 wild bird species from the central Monte desert, Argentina

Birds have the potential to be considered valuable bioindicators of the quality of ecosystems and the environmental impact of pollutants. The aims of this study were to determine the micronuclei frequency and other nuclear abnormalities in erythrocytes by analyzing a wild bird community from central Monte desert (Argentina) and to clarify if there were any differences among certain species. Frequencies of nuclear abnormalities were determined in 73 wild birds belonging to 17 species and two orders (Passeriformes and Columbiformes). A high proportion of individuals, 90.4 and 80.9 %, had erythrocytes with micronuclei and nuclear buds, respectively. Notched nuclei, binucleated cells, nuclear tails, and nucleoplasmic bridges were also recorded. Certain species appeared to be more informative than others with regard to the possibility of being used as bioindicators of genetic damage. Saltator aurantiirostris and Columbina picui were the only species that showed significantly different frequencies of nuclear alterations, in comparison with the other species. The frequencies here presented are the first reported for these bird species from the orders Passeriformes and Columbiformes. This research supports the notion that the use of these biomarkers could be effectively applied to evaluate spontaneous or induced genetic instability in wild birds.

Cytogenetic analysis of oral mucosa cells, induced by chlorhexidine, essential oils in ethanolic solution and triclosan mouthwashes

OBJECTIVES

The aim of this study was to evaluate DNA damage and cytokinetic defects, proliferative potential and cell death caused by the frequent use of mouthrinses containing chlorhexidine, triclosan and essential oils in ethanolic solution, compared to a placebo mouthwash.

STUDY DESIGN

This double-blind, prospective, randomized clinical trial included 80 Caucasian patients. Subjects were divided into four groups: Group I used a mouthrinse, Triclosan; Group II used physiological saline; Group III used chlorhexidine; Group IV a mouthrinse with essential oils in ethanolic solution. All subjects used the mouthrinses for two weeks (15 ml, twice a day, rinsing for 30s). Two cell samples per subject were collected, before and after mouthrinse use (on day 0 and day 15). Samples were processed as follows: cell collection from cheeks with a cytobrush; cell centrifuge; slide preparation, fixation and staining; and fluorescent microscope analysis. 2000 exfoliated cells were screened for nuclear abnormalities, particularly the presence of micronuclei by means of cytome assay.

RESULTS

No significant differences between study times (before and after use of mouthwash) were identified for any of the variables studied (p>0.05). Differences between mouthrinse groups were also compared but no significant differences were found (p>0.05).

CONCLUSIONS

This study did not observe any genotoxic effect resulting from mouthrinse use.