Cytogenetic biomonitoring of peripheral blood and oral mucosa cells from car painters

Use of micronucleus cytome assays with buccal cells for the detection of genotoxic effects: A systematic review and meta-analysis of occupational exposures to metals

Micronucleus (MN) assays with buccal cells are at present widely used to investigate occupational exposures to genotoxic carcinogens. This article describes their use for the monitoring of metal exposed workers. We found in total 73 relevant articles, in the majority (97 %) increased MN and/or other nuclear anomalies were reported. Most studies were realized in South East Asia and South America. A variety of different occupations was studied including welders, electroplaters, painters, workers in battery recycling and production, tannery workers, dental technicians, miners, workers in foundries and smelters, and also subjects working in waste recycling, glass, aluminum and steel production. In many investigations the effects increased with the duration of the working period. The quality of individual studies was evaluated with a quality score tool. The number of cells was in most studies sufficient and DNA-specific stains were used. However, many studies have shortcomings, e.g. they focused solely on MN formation and did not evaluate anomalies, which provide additional information about the stability of the genetic material and acute cytotoxic effects. Only 35 % of the investigations contain quantitative information about exposures to metals and other toxicants. In 6 of these studies, correlations were observed between the concentrations of specific metals (As, Pb, Cr, Cd) in body fluids and MN frequencies. Taken together, the available data indicate that the MN assay can be used to detect chromosomal damage in metal exposed groups; furthermore, it enables also comparisons between subgroups differing in regard to their exposure and allows an estimation of the efficiency of protective measures. The exposure of workers to metals is currently controlled with chemical analytical measurements only, MN assays with buccal cells could contribute to further improve the safety at workplaces as they reflect the biological consequences including synergistic and antagonistic interactions between toxicants.

Increased DNA Damage, Instability and Cytokinesis Defects in Occupationally Exposed Car Painters

BACKGROUND/AIM

Car painting is considered an occupational exposure job with high risk for cancer development, due to the association with harmful chemicals and mutagens. This study aimed to profile car painters occupationally exposed and determine its association with DNA damage and genomic instability.

MATERIALS AND METHODS

We collected a questionnaire and buccal cells of 74 individuals (37 car painters and 37 non-exposed workers) paired by age, alcohol and smoking habits. The number of pyknotic cells, karyolitic cells, karyorrhetic cells, condensed chromatin, binucleated cells, basal cells, differentiated cells (DIFF), micronucleated cells and nuclear buds were evaluated using the Buccal Micronucleus Cytome Assay protocol.

RESULTS

A statistically significant increase was observed in all parameters (p<0.05) in the exposed group, but DIFF showed a statistically significant decrease (p<0.001), compared to the control group.

CONCLUSION

In association with the poor work environment and lack of personal and collective protective equipment, occupational exposure of car painters leads to high DNA damage, genomic instability and alterations in cellular kinetics.

Evaluation of oxidative and methylating DNA damage in painters occupationally exposed to organic solvents and paints

Introduction: The exposure to organic solvents and paints has been associated with genotoxicity and a greater risk of neoplasms. However, the type of DNA damage induced in humans by the exposure to these compounds, which would help explain the mechanisms of their genotoxicity, is still not fully characterized. Due to inadequate practices of occupational safety, car painters in the informal sector are a highly exposed group to organic solvents and paints. Objective: To identify the oxidative and methylating damage in the DNA of lymphocytes of car painters exposed to organic solvents and paints. Materials and methods: Isolated peripheral blood lymphocytes from 62 painters and 62 unexposed subjects were analyzed by the modified high-throughput comet assay with the Fpg and AlkA enzymes. The categories used for the evaluation of the DNA damage were basal damage (without enzymes), oxidative and methylating damage. The measurement parameter used to establish the damage was the percentage of DNA in the tail. Results: The percentage of DNA in the tail was higher in the exposed group compared to the unexposed group (p<0.05). In the exposed group, this percentage was higher in the oxidative damage category than the baseline (16.50 vs. 12.87; p<0.001), whereas methylating damage did not show significant differences (14.00 vs. 12.87; p>0.05). Conclusion: In this study, exposure to organic solvents and paints was associated with an increase in oxidative lesions in the DNA of car painters’ lymphocytes, such as the production of 8-oxodG and other formamidopyrimidine products which are considered highly mutagenic.

Assessment of DNA damage in car spray painters exposed to organic solvents by the high-throughput comet assay

Occupational exposure as a painter is associated with DNA damage and development of cancer. Comet assay has been widely adopted as a sensitive and quantitative tool for DNA damage assessment at the individual cell level in populations exposed to genotoxics. The aim of this study was to assess the application of the high-throughput comet assay, to determine the DNA damage in car spray painters. The study population included 52 car spray painters and 52 unexposed subjects. A significant increase in the %TDNA median (p <  0.001) was observed in the exposed group in comparison to the unexposed group. Neither age (%TDNA: p =  0.913) nor time of exposure (%TDNA: p = 0.398) were significantly correlated with DNA damage. The car spray painters who consumed alcohol did not show a significant increase in DNA damage compared to nonalcohol consumers (p  > 0.05). The results showed an increase in DNA breaks in car spray painters exposed to organic solvents and paints; furthermore, they demonstrated the application of high-throughput comet assay in an occupational exposure study to genotoxic agents.

Genotoxic and cytotoxic effects and gene expression changes induced by fixed orthodontic appliances in oral mucosa cells of patients: a systematic review

CONTEXT

The accumulation of chronic or severe acute DNA and cellular damage in oral mucosa cells is one of the main factors that help initiate a wide range of malignant lesions in the oral cavity. There has been considerable controversy in the literature about the effect of such sustained genotoxic and cytotoxic damage to oral mucosa cells.

OBJECTIVE

The aim of this systematic review, reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, is to investigate the effects of such interventions.

METHODS

Electronic and manual searches were performed (15 May 2015) for Randomized Clinical Trials/quasi-Randomized Clinical Trials that analyzed the genotoxic/cytotoxic effects of these types of oral appliances in humans. A primary outcome (cell/DNA damage) and a number of secondary outcomes were examined. Two reviewers carried out the study selection and performed a "risk of bias" assessment [Cochrane Collaboration's tool]. Wherever possible the meta-analysis was conducted on homogenous groups.

RESULTS

From the electronic search (2797), 6 studies met the eligibility criteria. Most studies (5/6) observed significant differences in most comparisons at the short-term (1-3 months) and long-term (24-48 months) evaluations, with respect to critically acute genotoxic/cytotoxic effects. Some of the studies (2/3) concluded that the post-removable effects at DNA/cellular levels were not significant (p > 0.05) with respect to the controls.

CONCLUSIONS

Acute DNA/cellular damage in oral mucosa cells is induced by orthodontic appliances. Nevertheless, even though these effects were no longer detected after removing the appliances, more rigorous RCTs are needed to explore the extent to which acquired damage can be observed in the oral mucosa.

Preliminary study of genotoxicity evaluation of orthodontic miniscrews on mucosa oral cells by the alkaline comet assay

Miniscrew implants are widely used nowadays in orthodontic treatments due to their good results in clinical practice. However, data regarding the biocompatibility of commercially available orthodontic miniscrews and temporary devices are very scarce, and their role as genotoxicity inducers has been not previously evaluated with the alkaline comet assay. The aim of this study was to investigate the DNA damage in buccal cells of patients subjected to orthodontic treatments. The alkaline comet assay has been applied in oral mucosa cells from patients treated with conventional orthodontic treatment in comparison to patients treated additionally with miniscrews, non-treated volunteers (control) and smoking volunteers (positive control). The application of orthodontic appliances and miniscrews induced significant and similar (2-fold) increases of %DNA in tail in comparison to control group. Females experienced a significant increase in %DNA in all the treatments in comparison to the control group, whereas males showed significant damage only with the combined orthodontic and miniscrew treatment. In conclusion, conventional orthodontic appliances induced genotoxicity, and the incorporation of miniscrews assayed did not imply any additional increase of DNA damage.