ONCOGENESIS FROM LOW-DOSE-RATE X-IRRADIATION

我们建议评估低剂量率伽玛照射的致癌风险 相对于高剂量率(36GY/小时)下的辐射风险。风险 将通过比较恶性转化的比例来衡量 C3H/10T1/2成纤维细胞经等剂量(0.25Gy4)处理后 剂量率从0.05~8Gy/小时。剂量率将 与总剂量成正比(恒定曝光时间)。曝光时间 将从0.5到5小时不等。恶变将被确定 从克隆形态和小鼠肿瘤诱导实验中得到验证。这个 实验将在37.5℃的指数培养条件下进行 在长时间的照射过程中。高剂量率和低剂量率照射将 用适当改装的伽马辐照器进行。

We propose to assess the oncogenic risk of low-dose-rate Gamma -irradiation relative to the risk of irradiation at high dose rate (36 Gy/hr). The risk will be measured by comparing the proportion of malignantly transformed C3H/10T1/2 fibroblasts following treatments of equal doses (0.25 Gy to 4 Gy) and at dose rates ranging from 0.05 Gy/hr to 8 Gy/hr. Dose rates will be proportional to total dose (constant exposure time). Exposure times will range from 0.5 to 5 hrs. Malignant transformation will be determined from clonal morphology and verified by murine tumor induction. The experiments will be performed with exponential cultures held at 37.5 C during protracted irradiation. High- and low-dose-rate irradiations will be performed with a suitably modified gamma irradiator.