Little M P
Department of Epidemiology and Public Health, Imperial College School of Medicine, St Mary's Campus, London, UK.
Int J Radiat Biol. 2000 Oct;76(10):1365-75. doi: 10.1080/09553000050151646.
To compare the degree of curvature in the dose-response for chromosome aberrations and for radiation-induced cancer.
Comparison of the ratio of the quadratic and linear coefficients (in dose) in Japanese atomic bomb survivor cancer incidence data, based on follow-up to 1987 and taking account of random errors in DS86 dose estimates with the same ratio in four datasets of chromosome aberrations in peripheral blood lymphocytes measured in vitro and exposed to 60Co gamma radiation.
There are no statistically significant differences between the four in vitro datasets in the ratio of the quadratic to the linear coefficients for dicentrics or chromosome translocations, nor are there indications of differences between this ratio for dicentrics and that for complete chromosome translocations (p > 0.1 in all cases). If the 0-4 Gy dose range is used in the Japanese atomic bomb survivor data, the ratio of the quadratic to the linear coefficients for all solid cancers is 0.06 -1 (95% CI -0.22, 0.67) and so is not significantly different from 0; this ratio is statistically highly inconsistent (p<0.0001) with the analogous ratio estimated for the in vitro chromosome aberration data (4.20 Sv-1; 95% CI 3.06, 6.51). By contrast, there are no statistically significant differences (p=0.42) between the ratio of the quadratic to the linear coefficients for leukaemia incidence in the Japanese cohort, 1.81 Sv-1 (95% CI 0.21, > 1,000), with that for chromosome aberrations in vitro. These results are not markedly changed if the 0-2 Gy dose range is used in the Japanese atomic bomb survivor data.
It is unlikely that in vitro chromosome aberrations could be a correlate for the initiating radiogenic lesions leading to radiation-induced solid cancers. However, taken together with certain other biological information, it may not be unreasonable on this basis to use in vitro chromosome aberrations in peripheral blood lymphocytes as a correlate of the radiogenic lesions leading to radiation-induced leukaemia.
比较染色体畸变和辐射诱发癌症的剂量反应曲线的曲率程度。
基于对日本原子弹爆炸幸存者至1987年的随访数据，比较二次项系数与线性系数之比（剂量方面），同时考虑DS86剂量估计中的随机误差，并将其与体外测量的外周血淋巴细胞经60Coγ射线照射后的四个染色体畸变数据集中的相同比例进行比较。
四个体外数据集在双着丝粒或染色体易位的二次项系数与线性系数之比上无统计学显著差异，双着丝粒的该比例与完全染色体易位的该比例之间也无差异迹象（所有情况p>0.1）。如果在日本原子弹爆炸幸存者数据中使用0 - 4 Gy剂量范围，所有实体癌的二次项系数与线性系数之比为0.06 - 1（95%可信区间 - 0.22, 0.67），与0无显著差异；该比例与体外染色体畸变数据估计的类似比例（4.20 Sv-1；95%可信区间3.06, 6.51）在统计学上高度不一致（p<0.0001）。相比之下，日本队列中白血病发病率的二次项系数与线性系数之比为1.81 Sv-1（95%可信区间0.21, >1,000），与体外染色体畸变的该比例无统计学显著差异（p = 0.42）。如果在日本原子弹爆炸幸存者数据中使用0 - 2 Gy剂量范围，这些结果无明显变化。
体外染色体畸变不太可能作为导致辐射诱发实体癌的初始辐射损伤的相关指标。然而，结合某些其他生物学信息，基于此将外周血淋巴细胞中的体外染色体畸变用作导致辐射诱发白血病的辐射损伤的相关指标可能并非不合理。
