Hakoda M, Akiyama M, Kyoizumi S, Awa A A, Yamakido M, Otake M
Department of Radiobiology, Radiation Effects Research Foundation, Hiroshima, Japan.
Mutat Res. 1988 Sep;201(1):39-48. doi: 10.1016/0027-5107(88)90109-1.
Frequencies of mutant T-cells in peripheral blood, which are deficient in hypoxanthine guanine phosphoribosyltransferase (HPRT) activity, were determined for atomic bomb survivors by direct clonal assay using a previously reported method (Hakoda et al., 1987). Results from 30 exposed survivors (more than 1 rad exposed) and 17 age- and sex-matched controls (less than 1 rad exposed) were analyzed. The mean mutant frequency (Mf) in the exposed (5.2 X 10(-6); range 0.8-14.4 X 10(-6)) was significantly higher than in controls (3.4 X 10(-6); range 1.3-9.3 X 10(-6)), which was not attributable to a difference in non-mutant cell-cloning efficiencies between the 2 groups, which were virtually identical. An initial analysis of the data did not reveal a significant correlation between individual Mfs and individual radiation dose estimates when the latter were defined by the original, tentative estimates (T65D), even though there was a significant positive correlation of Mfs with individual frequency of lymphocytes bearing chromosome aberrations. However, reanalysis using the newer revised individual dose estimates (DS86) for 27 exposed survivors and 17 controls did reveal a significant but shallow positive correlation between T-cell Mf values and individual exposure doses. These results indicate that HPRT mutation in vivo in human T-cells could be detected in these survivors 40 years after the presumed mutational event.
采用先前报道的方法（Hakoda等人，1987年），通过直接克隆测定法确定了原子弹爆炸幸存者外周血中次黄嘌呤鸟嘌呤磷酸核糖转移酶（HPRT）活性缺乏的突变T细胞的频率。分析了30名受照射幸存者（受照剂量超过1拉德）和17名年龄及性别匹配的对照者（受照剂量低于1拉德）的结果。受照射者的平均突变频率（Mf）为5.2×10⁻⁶（范围为0.8 - 14.4×10⁻⁶），显著高于对照组（3.4×10⁻⁶；范围为1.3 - 9.3×10⁻⁶），这并非归因于两组非突变细胞克隆效率的差异，两组的非突变细胞克隆效率实际上是相同的。对数据的初步分析未发现个体Mf与个体辐射剂量估计值之间存在显著相关性，当后者由最初的暂定估计值（T65D）定义时，尽管Mf与携带染色体畸变的淋巴细胞个体频率存在显著正相关。然而，对27名受照射幸存者和17名对照者使用更新的修订个体剂量估计值（DS86）进行重新分析，确实发现T细胞Mf值与个体暴露剂量之间存在显著但较弱的正相关。这些结果表明，在假定的突变事件发生40年后，在这些幸存者体内可以检测到人类T细胞中的HPRT突变。
