摘要
目的建立0～1Gy范围内^60Coγ射线、^252Cf中子、单能中子及^12C重离子诱发染色体畸变剂量一效应曲线，用于评价职业受照或低剂量辐射损伤。方法采用不同照射装置1Gy以内照射离体人外周血，于培养开始加秋水仙素，培养48h收获，制备染色体标本，Metafer中期细胞自动寻找系统，人机交互计数染色体畸变，最优拟合数据得到相应模型。结果在低剂量范围内，以双着丝粒体＋环（dic＋r）为终点，^60Coγ射线为线性模型，^252Cf中子、单能中子及^12C重离子为线性平方模型；以无着丝粒断片（ace）为终点，^60Coγ射线和^12C重离子为线性平方模型，^252Cf中子和单能中子为线性模型；以总畸变为终点，4种射线均为线性平方模型。结论高传能线密度（LET）射线损伤效应高于低LET射线，4种射线损伤效应依次为。^252Cf混合中子〉单能中子〉^12C重离子〉^60Coγ射线。在低剂量范围内dic＋r指标适用于高LET照射的剂量估算。
Objective To establish the dose-effect curves of chromosome aberrations in human peripheral blood lymphocytes induced by different LET rays, including ^60Co γ-rays, 252Cf neutrons, 14 MeV neutrons and 12C heavy ions at low doses, respectively, in order to assess radiation-induced damages after occupational and accidental exposure. Methods Heparinized whole blood samples were irradiated with the various radiation devices and doses ranged from 0 to 1 Gy with the interval of 0.25 Gy. Conventional chromosome cuhure method was applied with adding colchicines at the beginning and chromosome specimens were prepared after 48 h incubation. The Metafer scanning system was used for automatical finder of chromosome metaphases. The mathematic models were fitted according to aberration data obtained. Results At the dose range of 0 - 1 Gy, the math models of dic ＋ r were linear for 60Co γ- rays and linear-quadratics for 252 Cf neutrons, 14 MeV neutrons and 12 C heavy ions. The models of ace were linear-quadratic for ^60Co γ-rays and 12C heavy ion beams, and linear for 252Cf and 14 MeV neutrons. The models of total aberrations were linear-quadratic for all types of radiation. Conclusions High LET rays have higher biological effects in inducing chromosome aberrations yields compared with low LET rays. Moreover, the severity of damage is 252Cf 〉 14 MeV neutrons 〉 12C heavy ions 〉 ^60Co γ-rays in turn. Therefore, in the range of low doses, the dic ＋ r may be a better target of radiation damage for high LET radiation.
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
2011年第5期531-535,共5页
Chinese Journal of Radiological Medicine and Protection
基金
军队“十一五”科技攻关项目（08G143）
关键词
电离辐射
传能线密度
低剂量
染色体畸变
剂量-效应曲线
Ionizing radiation
Linear energy transfer
Low doses
Chromosome aberrations
Dose-effect curve
