No abstract

In this study, the micronuclei test (MNT) was applied in exfoliated cells of buccal mucosa, in order to evaluate the genotoxic risk associated with occupational exposure of mechanics, storage battery renovation workers, and car painters. For each individual, 3000 exfoliated buccal cells were analyzed. There was a significantly higher frequency of micronucleated cells (MNC) in the exposed workers than in controls. Smoking and drinking habits, age, and working time did not represent significant factors in terms of increasing the production of micronuclei (MN), when the control and the exposed groups were compared. These results allowed to conclude that the studied individuals belong to a risk group and should periodically undergo biological monitoring and proper care.

ABSTRAcT. Patients with chronic renal disease have an increased incidence of cancer. It is well known that long periods of hemodialysis treatment are linked to DNA damage due to oxidative stress. This genotoxic effect may cause the loss of chromosome fragments, or even entire chromosomes, which form micronuclei after cell division, and can be detected by the micronucleus test. In the present case-control study, we evaluated the genotoxic effect of hemodialysis treatment in 20 patients undergoing hemodialysis, and 20 subjected to peritoneal dialysis, matched for gender and age with 40 controls. Genetic damage was assessed by examining the frequency of micronuclei in 2000 exfoliated buccal cells per individual. Our results revealed that patients undergoing hemodialysis treatment have a significantly higher frequency of micronucleated cells (MNC; 5.60 ± 5.31) compared to control subjects (1.50 ± 2.01, P < 0.01). Interestingly, the same was not observed for the peritoneal dialysis patients who showed no significant differences in MNC (2.85 ± 2.96) frequency compared to control individuals (3.25 ± 3.85). In addition, we evaluated the possible association between creatine levels, smoking, alcohol intake, age, duration of treatment, and incomes of the individuals (separately analyzed according to their gender) and the frequency of micronuclei. The results reported here indicate that the duration of treatment is the only factor associated with increased MNC frequency among hemodialysis patients (Spearman coefficient of 0.414, P = 0.01). The number of MNC found in individuals with six years or less of treatment was significantly lower (2.91 ± 2.74) compared to patients with seven or more years of treatment (8.89 ± 5.96, P < 0.05). Overall, peritoneal dialysis may be a safer choice of treatment, but further studies need to be performed to investigate the risks and benefits of both treatments.

ABSTRACT. Down syndrome has been linked to premature aging and genomic instability. We examined the frequency of micronucleus (MN) and binucleated cells in the oral mucosa of Down syndrome patients and healthy controls matched by age and gender, addressing the effect of age and family income. Down syndrome individuals had an increased number of MN (14.30 ± 9.35 vs 4.03 ± 1.71; P < 0.001) and binucleated cells (0.97 ± 1.3 vs 0.33 ± 0.66; P < 0.05) per 2000 cells. Micronucleus frequency of Down syndrome individuals correlated positively with age (r = 0.437; P = 0.009), and the older (≥21) Down syndrome age group (30.8 ± 8.4 years old) had about 2-fold more micronuclei (P ≤ 0.05) than did the younger group (<21). Average family income did not correlate with MN frequency in controls (r = -0.948; P = 0.183), but a borderline negative correlation was seen in DS subjects (r = -0.9484; P = 0.0516). Individuals whose average income was ten times minimum wages had about 2-fold less MN than those receiving around minimum wage. We conclude that the buccal MN assay is a useful and minimally invasive method for monitoring genetic damage in humans and could be used as a tool to evaluate ageassociated genomic instability in Down syndrome.