Increased micronucleus, nucleoplasmic bridge, nuclear bud frequency and oxidative DNA damage associated with prolactin levels and pituitary adenoma diameters in patients with prolactinoma

Prolactinoma is the most common pituitary tumor. Most pituitary tumors are benign, but they often are clinically significant. We investigated cytokinesis-block micronucleus cytome (CBMN cyt) assay parameters and oxidative DNA damage in patients with prolactinoma to assess the relations among age, prolactin level, pituitary adenoma diameter and 8-hydroxy-2'-deoxyguanosine (8-OHdG) level in patients with prolactinoma. We investigated 27 patients diagnosed with prolactinoma and 20 age- and sex-matched healthy controls. We measured CBMN cyt parameters and plasma 8-OHdG levels in peripheral blood lymphocytes of patients with prolactinoma and controls. The frequencies of micronucleus (MN), nucleoplasmic bridge, nuclear bud, apoptotic and necrotic cells, and plasma 8-OHdG levels in patients with prolactinoma were significantly greater than controls. MN frequency was correlated positively with age, prolactin levels and pituitary adenoma diameters in patients with prolactinoma. The increased chromosomal and oxidative DNA damage, and the positive correlation between MN frequency, prolactin levels and pituitary adenoma diameters may be associated with increased risk of cancer in patients with prolactinoma, because increased MN frequency is a predictor of cancer risk.

Increased micronucleus frequency in phytohaemagglutinin-stimulated blood cells of patients with vitiligo

BACKGROUND

Vitiligo is a relatively common, acquired pigmentary disorder characterized by areas of depigmented skin resulting from loss of melanocytes in the epidermis. Although several hypotheses have been proposed for the aetiology and pathogenesis of vitiligo, the cause of vitiligo remains unclear.

OBJECTIVE

To evaluate spontaneous micronucleus (MN) frequency using the cytokinesis block MN assay to determine damages at the DNA or chromosome level in phytohaemagglutinin (PHA)-stimulated blood cells of patients with vitiligo and healthy control subjects.

METHODS

Peripheral blood samples were obtained and cultured from 21 patients with vitiligo (mean age: 21.48 +/- 9.78 years) and 21 age- and sex-matched healthy control subjects (mean age: 21.52 +/- 9.80 years). MN values were scored in binucleated cells obtained from whole-blood cultures of patients and control subjects.

RESULTS

MN frequencies (mean +/- SD) in PHA-stimulated blood cells of patients with vitiligo and control subjects were 0.94 +/- 0.58 and 0.58 +/- 0.32, respectively. Compared with control subjects, MN frequencies of patients with vitiligo were found significantly higher than those of the control subjects (P = 0.012).

CONCLUSION

Our results indicate unexpectedly some chromosomal/DNA damage in whole-blood cultures of patients with vitiligo. We do not know, however, if these chromosome/DNA instabilities observed in the cells of vitiligo patients resulted from the cause or from the consequences of the disorder.

Micronucleus frequency in the oral mucosa and lymphocytes of patients with Behcet's disease

Behçet's disease (BD) is a chronic, multisystemic, inflammatory disorder characterized mainly by recurrent oral and genital aphthous ulcerations and uveitis. Our study aimed to determine the genetic damage in patients with BD. The micronucleus (MN) frequency was counted in peripheral lymphocytes and exfoliated cells of the patients with BD. MN analysis was performed in peripheral lymphocytes of 30 patients with BD and in 20 healthy controls by the cytokinesis-block method, and on uncultured cells of the oral cavity in 10 patients and 9 healthy controls. We found significantly higher MN rates in lymphocytes of the patients than the control subjects (P = 0.000). There were no significant differences between the patients with or without treatment (P = 0.860). The MN frequency in exfoliated cells of the patients was higher than in those of healthy controls (P = 0.013), and there was no significant difference between the exfoliated cells of the treated and untreated patients (P = 0.201). Our results indicate that genetic damage may play a secondary but important part in the aetiology of BD and that treatment with colchicine does not induce MN.

Micronucleus frequencies in workers exposed to lead, zinc, and cadmium

Micronuclei (MN) in blood lymphocytes were determined in 31 male workers occupationally exposed to lead (Pb), zinc (Zn), and cadmium (Cd) and 20 control workers matched for age and smoking habits. Exposed workers have higher MN mean values than control workers (p < 0.01). In exposed workers, blood Pb concentrations were also significantly higher than in control workers (p < 0.001), but the mean concentrations of Zn and Cd in the blood were not statistically significant compared to the controls (p > 0.05). These results suggest that lead may be genotoxic and the human lymphocyte micronucleus test can be used to assess genotoxic effects that result from occupational exposures.