Thierens H, Vral A, Morthier R, Aousalah B, De Ridder L
Department of Biomedical Physics and Radiation Protection, University of Ghent, Proeftuinstraat 86, Ghent, Belgium.
Mutagenesis. 2000 May;15(3):245-9. doi: 10.1093/mutage/15.3.245.
A cytogenetic study was performed in lymphocytes of hospital workers occupationally exposed to X- and gamma-rays using the micronucleus centromere assay. A comparison of the data for the exposed group and an age-matched group of non-exposed hospital workers showed a significant (P < 0.05) increase in centromere-positive micronuclei for the radiation workers, while no effect on centromere-negative micronuclei was present. The observed systematic increase in micronucleus frequency with age was mainly due to increased chromosome loss, reflected in the centromere-positivity of the micronuclei. The micronucleus frequencies were 40% higher in females than in males, which can again be attributed to higher chromosome loss. Two exposed individuals showed exceptionally high micronucleus yields, 90% of which were centromere-positive. In situ hybridization with a centromeric probe for chromosome X shows that X chromosome loss is responsible for these high micronucleus yields. In the studied population, smoking had no significant effect on the micronucleus yields. The results obtained indicate that in contrast to the predominantly clastogenic action of acute exposure to ionizing radiation, the aneugenic properties of radiation may be important after long-term chronic low dose exposure.
采用微核着丝粒分析法，对职业性接触X射线和γ射线的医院工作人员的淋巴细胞进行了细胞遗传学研究。将暴露组数据与年龄匹配的未暴露医院工作人员组进行比较，结果显示，辐射工作人员着丝粒阳性微核显著增加（P < 0.05），而对着丝粒阴性微核无影响。观察到的微核频率随年龄的系统性增加主要是由于染色体丢失增加，这反映在微核的着丝粒阳性上。女性的微核频率比男性高40%，这同样可归因于更高的染色体丢失。两名暴露个体的微核产率异常高，其中90%为着丝粒阳性。用X染色体着丝粒探针进行原位杂交表明，X染色体丢失是这些高微核产率的原因。在研究人群中，吸烟对微核产率无显著影响。所得结果表明，与急性暴露于电离辐射主要产生断裂效应不同，长期慢性低剂量暴露后，辐射的非整倍体特性可能很重要。
