A proposal of a standardised nomenclature for terminal minute sister chromatid exchanges

We described spontaneous minute sister chromatid exchanges (SCE) in telomeric regions of human and Chinese hamster ovary (CHO) chromosomes more than 10 years ago. These structures, which we called t-SCE, were detected by means of highly precise quantitative microphotometrical scanning and computer graphic image analysis. Recently, several authors using the CO-FISH method also found small SCEs in telomeric regions and called them T-SCE. The use of different terms for designating the same phenomenon should be avoided. We propose ter SCE as a uniform nomenclature for minute telomeric SCEs.

Sister chromatoid exchanges and chromosome aberrations in lymphocytes of medical personnel handling cytostatic drugs

Many anticancer drugs, including cytostatic drugs, are genotoxic. Evidence on human carcinogenicity has been conclusive. Persons handling these drugs might be exposed to an occupational health hazard, as they cause chromosomal damage in the lymphocytes. This study was conducted on 30 Egyptian medical personnel handling cytostatic drugs, working in the Medical Research Institute, Alexandria University and Gamal Abd El Naser Hospital in Alexandria. A control group comprised 30 normal healthy individuals matched for age and sex and had no contact with cytostatic drugs. Also, they were not exposed to any mutagenic agents. The workers and controls were interviewed to exclude exposure to any mutagenic agents other than anticancer drugs in case of medical workers. Cytogenetic methods were done to all subjects to assess chromosomal aberrations [CA] and sister chromatid exchanges [SCE]. Significantly increased frequencies of CA and SCEs were found in exposed personnel as compared to the controls. Chromosomal aberrations and SCEs frequencies were not correlated with the age of exposed personnel and duration of exposures to cytostatic drugs. There was no increased risk of malformed children in exposed females and no history of repeated abortion. The results of this study point to the handling of cytostatic drugs as a possible genotoxic hazard. Therefore, effective protection and care in handling must be further emphasized to prevent adverse effects

Screening of chromosomal aberrations [CA] and sister chromatid exchange [SGE] in the lymphocytes of operating room personnel

This work was done to obviate the controversy about the mutagenicity of chronic exposure to traces of inhalational anesthetics. Sixty adult non smoker heal thy individuals of both sexes were the subject of this study. These individuals were selected from Zagazig University Hospital personnel. The first half of these individuals was from operating room personnel i.e. personnel who had been exposed to the currently used inhalational anesthetics [ether, halothane and N[2]O] during their practice. In contrast the other half was from individuals who were not previously exposed to either inhalational anesthetics or irradiations e.g. physicians and out-patients clinic personnel. According to the durations of working which were, more than 15 years, from 10 to 15 years and from 5 to 10 years, both exposed and non exposed personnel were divided into three equal groups: I, II and III respectively for the first and A, B and C respectively for the latter. Group A, B and C were served as control groups to group I, II and III respectively. Venous blood samples were taken from all selected personnel and prepared for screening of both CA and SCE [as indicator to mutagenicity]. One hundred metaphases [lymphocytes] were examined for screening CA and other 100 metaphases were examined for screening of SCE in each individual. From this study, it was found that, only group I personnel [more than 15 years exposure] showed significant higher incidences of metaphases with CA and SCE and significant higher frequencies of CA and SCE. In conclusion, this study proved that prolonged exposure to traces of the currently used inhalational anesthetics [ether, halothane and N[2]O] is potentially mutagenic to operating room personnel. So, operating rooms must be provided with scavenging systems to prevent or at least minimize this adverse effect

Sister chromatid exchanges in congenital cataracts.

A total of 25 patients with bilateral congenital cataracts, from three aetiological groups i.e. rubella (6 patients) hereditary (6 patients) and undetected aetiology (13 patients) were studied for sister chromatid exchanges (SCE). SCEs were markedly raised in the rubella groups as compared with age sex matched controls. The other two groups also showed raised SCE, more so in hereditary group.