不同结构类型双着丝粒体建立的剂量-效应曲线估算剂量可行性研究

Study on the feasibility of dose estimation by the dose-response curves based on different types of dicentrics

目的探讨基于不同结构类型双着丝粒体(dicentrics,dic)建立的剂量-效应曲线估算生物剂量的可行性。方法采集两名健康人外周血样品,用0、0.5、1、2、3、4、5和6 Gy 60Coγ射线(剂量率为0.27 Gy/min)离体照射人外周血,常规培养、收获和制备染色体标本,镜下分析并记录不同结构类型dic;应用CABAS软件建立dic剂量-效应曲线;并对两验证样本进行剂量估算。结果不同结构类型dic率均随受照剂量的增加而升高(R^2=0.886~0.943,P<0.01),各剂量点经典型和单端型dic构成比之和约占所有类型dic的92%以上,而近距型dic和双端型dic分别在各照射剂量点的构成比均<4%。不同结构类型dic剂量-效应曲线的R^2值均达到0.998;应用4条曲线估算的受照射剂量差异无统计学意义(P>0.05)。经典型dic剂量-效应曲线估算较高剂量时(3.9 Gy),相对偏差均≤13.08%。结论基于不同结构类型dic建立的剂量效应曲线具有估算生物剂量的可行性。

Objective To investigate the feasibility of dose estimation based on the doseresponse curves established by different types of dicentrics(dic).Methods Human peripheral blood samples were irradiated by 60Coγ-rays at the doses of 0,0.5,1,2,3,4,5 and 6 Gy with the dose rate of 0.27 Gy/min,and chromosome preparation was carried out.The different types of dics were analyzed.The dose-response curves were fitted with software of Chromosomal Aberration Calculation Software(CABAS).Two samples were used to validate the dose-response curves.Results The aberration rates of different types of dics increased with the exposure doses(R^2=0.886-0.943,P<0.01).The proportion of typical and single-ended dic components accounted for more than 92%of all types of dic,while the proportion of short-range dic and double-ended dic components was less than 4%at each dose point.The dose-response curves based on different types of dics were established(R^2=0.998,P<0.01).There was no significant difference in the doses estimated by four different dose-response curves(P>0.05).The relative deviations between actual and predict doses were less than 13.08%by using dose-response curve based on typical dics.Conclusions Dose-response curves based on different types of dics have the feasibility of dose estimation.