Cytogenetic and molecular genetic studies on the atomic-bomb survivors

对距震源中心500米以内的原子弹幸存者进行了细胞遗传学和分子遗传学研究。两年来取得的主要成果。对严重暴露在原子弹下的幸存者的跟踪调查对暴露在原子弹下的人的年度跟踪调查显示，有两人死于结肠癌。三名幸存者最近被发现患有癌症，一名膀胱癌，两名结肠癌。重度暴露组脑膜瘤发生率高，暴露组38例，非暴露组607例。接触一种以上灰色的人群脑膜瘤的发病率明显更高。发病率与照射剂量有关。健康幸存者外周血中WT1基因产物从距震源500米范围内的幸存者中获得了10份血液样本。在10个样本中，4个样本的2号基因信使RNA水平在正常范围内，呈中高水平，其余样本无法测量。无剂量依赖性。应用FISH技术对8例暴露量大于2gy的白血病患者进行了亚克隆检测，并与g带分析的核型进行了比较。在这8名患者中，有6名患者显示出异常的亚克隆，或者是单体7,17p -和20q-。在8例白血病患者中，4例患者也发现MYC或p53基因扩增。

Cytogenetic and molecular genetic studies were carried out on the atomic-bomb survivors who had been exposed within 500 meters from the hypocenter.The main results obtained in the past two years1. Follow up of the heavily exposed A-bomb survivors Annual follow up of the exposed people revealed two death of colon cancers. Three survivors were newly found to have cancers, one bladder cancer and two colon cancers.2. A high incidence of meningioma was found among heavily exposed groupThirty eight meningioma patients in exposed group as well as 607 patients in non-exposed group were collected from the database of Hiroshima Tumor Registration. The group exposed more than one gray had significantly higher incidence of meningioma. The incidence were correlated with radiation dose exposed.3. WT1 gene product in the peripheral blood of healthy survivorsTen blood samples were available from the survivors exposed within 500 meters from the hypocenter. Of the ten, four showed a moderate to high level of messenger RNA of the gene 2 within normal level and the remainings un-measurable. No dose-dependency was observed.4. Detection of subclones by FISH techniqueEight leukemia patients who had been exposed more than 2 Gy were examined by FISH technique comparing with the karyotype analyzed by G-banding method. Of the eight patients six were shown to have abnormal subclones either with monosomy 7, 1 7p- and 20q-. Amplification of MYC or p53 genes were also found in four patients among the eight leukemia patients.