An attempt to develop a biodosimeter for detecting low dose and low dose rate radiation

我们试图开发一种新的生物剂量计来检测低剂量和低剂量率辐射。将正常（野生型细胞）和双链断裂修复缺陷小鼠细胞（SCID细胞）分别暴露在低剂量率和高剂量率的γ射线下，并进行剂量分割和不同的恢复时间，以研究剂量率效应和亚致死和潜在致死损伤的修复。此外，5-氟尿嘧啶（5-FU），一种常用的癌症治疗药物，被广泛使用，因为它会产生双链断裂。即使在剂量分离和24h恢复期后，SOlD细胞对5-FU或γ射线诱导的DNA损伤的修复能力仍然不足，而野生型细胞对5-FU或γ射线照射后的DNA损伤具有明显的修复能力。我们认为SCID细胞是检测低剂量辐射损伤的一种有用的生物剂量计系统。现在，我们正在尝试建立一种方法来计算SCID细胞中双链断点的数量。

We attempted to develop a new biodosimeter to detect the low dose and low dose rate radiation.Normal (wild type cells) and double-strand break repair deficient murine cells (SCID cells) were exposed to gamma-rays at low and high dose rates with dose fractionation and with different recovery times, in order to examine the dose rate effectiveness and repair of sublethal and potentially lethal damage.In addition, 5-fluorouracil (5-FU), a commonly used drug for cancer therapy, was a]so used, because it produces double-strand breaks.SOlD cells showed deficiency in repairing DNA damage induced by 5-FU or gamma-rays even after dose fractionation and after 24h recovery periods, while the wild type cells showed an apparent repair ability on DNA damage after 5-FU treatment or gamma-rays exposure.We conclude that the SCID cell is useful system as a biodosimeter for detecting the damage of low dose radiation.Now, we are trying to establish a method to count the number of double-strand break points in a SCID cell.