摘要
目的 重离子和高剂量率6 0 Coγ射线照射离体人血建立染色体畸变的剂量 效应曲线 ;比较重离子1 2 C照射与6 0 Coγ射线照射诱发染色体畸变的相对生物效能。方法 重离子1 2 C和6 0 Coγ射线照射离体人血 ,吸收剂量率为 3Gy min ,吸收剂量为 1 0～ 8 0Gy。主要记录染色体型畸变的非稳定性畸变 ,对双着丝粒体和着丝粒环做曲线拟合 ,并检验回归系数的显著性和曲线的拟合度。结果 重离子1 2 C和6 0 Coγ射线照射离体血诱发的染色体畸变 (双 +环 ) ,在 0～ 8Gy范围内 ,呈良好的剂量 效应关系。1 2 C离子诱发染色体畸变的RBE值是不恒定的 ,它随吸收剂量增加而减少 ,在 0 3～ 8 0Gy范围内 ,RBE值 (Dγ Dc)从 2 6 2到 1 0 0 ,平均 1 5 8。结论 1 2 C离子对6 0 Coγ射线照射诱发染色体畸变 ,在照射剂量较低时 ,有较高的生物效应。
Objective To compare the effectiveness of heavy ion versus 60 Co γ-rays in producing chromosomal aberrations in human lymphocytes. Methods Heparinized whole blood samples were exposed to heavy ion 12 C and 60 Co γ-rays,respectively.Unstable chromosomal aberrations including acentric fragments,minutes,acentric rings,dicentrics and centric rings(“dic+r”) were scored.Relative biological effectiveness (RBE) values of “dic+r” were derived. Results Chromosomal aberrations (“dic+r”) induced by either heavy ion 12 C or 60 Co γ-rays had a good dose-response relationship.Their best fitiing regression equations were Y =0\^858503D+0\^36154×10 -2 D\+2 ( R =0.9840) and Y =0\^269792D+7\^73083×10 -2 D\+2 ( R =0.9920),respectively.RBE values of heavy ion at 0.3-8.0 Gy ranged from 2\^62 to 1\^0,with an average of 1\^58. Conclusion Heavy ion 12 C has higher biological effectiveness in inducing chromosomal aberrations.
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
2003年第4期258-260,共3页
Chinese Journal of Radiological Medicine and Protection
