Molecular and cytogenetic studies on hematopoietic cells in heavily exposed A-bomb survivors

一、目前没有临床问题的重度接触原子弹幸存者的研究；a)细胞遗传学研究显示，5-45.6%的外周血淋巴细胞染色体异常。B)抗Bast抗体的血清学研究表明，近距离照射组中位置病例的百分比明显较高。c)分子生物学研究分别在2名和1名幸存者中发现了转化-N-ras和K-ras基因。ii.对有原子弹辐射病史的白血病患者进行了研究。a)急性白血病的细胞遗传学研究：对75名广岛与辐射有关的白血病(急性非淋巴细胞)进行了细胞遗传学检查，其中包括16名暴露于一种以上Gray的患者。根据DS86估计的骨髓剂量，对幸存者的染色体畸变率数据进行统计分析，结果表明，重度接触者的畸变率往往明显高于非接触者。此外，观察到幸存者的染色体异常具有更复杂的性质，具有继发性白血病的特征性表现。b)暴露组和非暴露组进行了急、慢性白血病转化基因和慢性粒细胞白血病bcr基因的分子生物学研究。到目前为止，在N-点突变的频率和位置上还没有观察到明显的差异。以及K-ras基因或bcr基因重排，以最终得出辐射诱导白血病的特异性结论。

I. Studies on heavily exposed A-bomb survivors who have no clinical trouble at present ;a)Cytogenetic studies revealed 5- 45.6% of chromosome abnormalities in the peripheral lymphocytes, which were. estimated to be 9- 650 rad of exposure at the time of bombing.b)Serological studies for anti-BAST antibody shown that percent of position cases was significantly higher in the proximally exposed group.c)Molecular-biological studies revealed the transforming -N-ras and K-ras genes in two and one survivors, respectively.II. Studies on leukemia patients with a history of exposed to Atomic Bomb Radiation.a)Cytogenetic study on acute leukemia :Seventy five radiation--'related leukemia(acute non-lymphocyte)in Hiroshima including 16 patients exposed to more than one Gray were cytogenetically examined. Statistical analysis of the data on the frequencies of chromosomal aberrations in survivors according to the bone marrow doses of DS86 estimation revealed that heavily exposed patients tended to have significantly higher aberration rates as compared, -with non-exposed patients. Furthermore, the chromosomal aberrations in the survivors were-observed to be of a more complex nature and had characteristic findings of secondary leukemia.b)Molecular biological studies on transforming genes in acute and chronic leukemia and the bcr gene in chronic myelocytic leukemia have been performed in exposed and non-exposed groups. So far, no distinctive differences have been observed in the frequency and the sites of point mutations in N-. and K-ras genes or in the rearrangement of the bcr gene, for a final conclusion of the specificity of radiation induced leukemia.