Frequency of sister chromatid exchanges in the lymphocytes of patients with atopic dermatitis

Assessment of genotoxicity of pyrethrin in cultured human lymphocytes

Pyrethrin is an insecticide that is obtained from the Chrysanthemum flower (Pyrethrum). In this study, we examined the genotoxic effects of pyrethrin on cultured human lymphocytes using sister chromatid exchanges (SCEs) and 8-hydroxy deoxyguanosine (8-OHdG) assays. Cultures were treated with different concentrations of pyrethrin (25, 50, and 100 μg/mL), which was dissolved in in dimethyl sulfoxide (DMSO). The results showed that treatment of cultured lymphocytes with pyrethrin at 50 μg/mL and 100 μg/mL induced significant elevation in SCEs (p < 0.05). In addition, the 100 μg/mL concentration significantly affected both mitotic and proliferative indices (p < 0.05). Finally, pyrethrin induced significant elevation in the oxidative stress marker 8-OHdG in a dose-dependent manner (p < 0.001). In conclusion, the results suggest that pyrethrin is genotoxic as measured by two independent assays on genetic toxicity.

Sister chromatid exchange in Greenleg Partridge and Polbar hens covered by the gene-pool protection program for farm animals in Poland

A basic assay that detects genotoxic DNA damage disrupting DNA replication and repair mechanisms is the sister chromatid exchange test. The frequency of sister chromatid exchanges was analyzed in chromosomes of the following hen breeds: Greenleg Partridge and Polbar. Chromosome preparations were obtained from our in vitro culture of peripheral blood lymphocytes stained using the fluorescence plus Giemsa (FPG) technique. The sister chromatid exchange (SCE)/cell mean of the hens under analysis was 7.83 ± 1.76 (7.22 ± 1.70 in the Greenleg Partridge and 8.43 ± 1.61 in the Polbar population). Statistically significant differences were identified between the hen breeds. A higher mean number of SCE/cell was observed in the group of hens producing fewer eggs (8.55 ± 1.51) compared with the group with a better egg yield (7.10 ± 1.65). The differences were statistically significant. Additionally, SCE frequency in the first, second, and third chromosome was analyzed in detail. The highest number of SCE was observed in the first and the lowest in the third chromosome. The SCE distribution in the particular regions of the analyzed chromosomes was also studied. The most numerous exchanges were observed in the proximal region, followed by the interstitial and distal areas.

Effect of every-other-day fasting on spontaneous chromosomal damage in rat's bone-marrow cells

Dietary restriction in experimental rodents, either by calorie restriction (CR) or by every-other-day fasting (EODF), was shown to protect against cancer and increase lifespan. One of the suggested hypotheses to explain the beneficial effects of dietary restriction is that the diet stabilizes the integrity of the genetic information. The effects of EODF on the spontaneous frequency of sister chromatid exchanges (SCE) and chromosomal aberrations (CA) were examined in bone-marrow cells of 3-mo-old Wistar male rats. After 12 wk of EODF diet, significant reduction in the frequency of SCE and total number of CA was observed. Data indicate a protective effect of EODF diet against spontaneous mutations in rats.

Sister chromatid exchange analysis in patients with psoriasis

Psoriasis is a common, chronic inflammatory skin disease with unknown aetiology. An increased reactive oxygen species (ROS) and insufficient antioxidant activity have been determined in psoriatic lesions. The analysis of sister chromatid exchange (SCE) is a cytogenetic technique used to show DNA damage caused by an exchange of DNA fragments between sister chromatids. The study aimed to determine the rates of SCE in psoriatic patients (17 female and 19 male) and healthy controls (15 female and 15 male) as well as superoxide dismutase (SOD), glutathione peroxidase (GP) and catalase (CAT) activity in both groups. We found significantly higher SCE rates in the patients (P < 0.00001). In addition, statistically significant decreased levels of erythrocyte SOD and CAT activities were noted in the patients(P < 0.001 and P < 0.05 respectively). Furthermore, a statistically significant increased erythrocyte GP activity was found in the psoriasis group (P < 0.05). Our results indicate that chromosomal instability may play an important part in the aetiology of psoriasis. In addition, the results support the hypothesis of an imbalance in the oxidant-antioxidant system in psoriasis.