tailieunhanh - The effects of micronuclei with whole chromosome on biological dose estimation

The total micronucleus (MN) assay has been used for purposes of biological dosimetry for many years. The variable spontaneous incidence of micronuclei in peripheral blood lymphocytes affects the sensitivity of biological dose estimations at low doses. It has been suggested that this problem could be solved by using the micronuclei-centromere assay. | Turk J Biol 32 (2008) 283-290 © TÜBİTAK The Effects of Micronuclei with Whole Chromosome on Biological Dose Estimation Funda S. PALA1, Fadime ALKAYA2, Kıymet TABAKÇIOĞLU1, Füsun TOKATLI2, Cem UZAL3, Şule PARLAR3, Çetin ALGÜNEŞ1 1 Trakya University, Medical Faculty, Medical Biology Dept. 22030 Edirne - TURKEY 2 Medicana International Hospital, Radiation Oncology Dept. 34800 İstanbul - TURKEY 3 Trakya University, Medical Faculty, Radiation Oncology Dept. 22030 Edirne - TURKEY Received: Abstract: The total micronucleus (MN) assay has been used for purposes of biological dosimetry for many years. The variable spontaneous incidence of micronuclei in peripheral blood lymphocytes affects the sensitivity of biological dose estimations at low doses. It has been suggested that this problem could be solved by using the micronuclei-centromere assay. In this study, Co-60 gamma ray dose response curves for micronuclei (MN) and micronuclei without centromeres (MNC-) in the range of Gy were established using a pancentromeric FISH probe on cultured binucleate lymphocytes from 2 donors. There were no significant inter-donor differences in the dose responses for either MN or MNC-. The relative proportions of MN that contained centromeres (MNC+) decreased with radiation dose, which is in line with the proposition that radiation predominately causes chromosomal breakage rather than whole chromosome loss. The α coefficients of MNC- curves decreased to 62% of the values for total MN whilst the β coefficients were unchanged. MN and MNC+ frequencies of 60 control smoker and 40 non-smoker donors were also compared. No effect of smoking was observed. However the MNC+ spontaneous frequencies showed an age and gender effect with the highest frequencies in older women. Key Words: Biodosimetry, Micronuclei, Micronuclei-centromere assay, Co-60 gamma dose response curve Tüm Kromozom Taşıyan Mikronukleusların Biyolojik Doz Değerlendirmelerindeki Etkisi Özet: Mikronukleus