To establish the method for estimate the late effect induced by local irradiation therapy by detecting chromosomal aberration of peripheral blood lymphocytes

为确定全身照射剂量，评价局部照射治疗后的远期效应，应用染色体着丝粒特异性探针进行荧光原位杂交（FISH）技术，对宫颈癌患者行10 MV X线局部照射50戈伊或100 Gy~（-1）Co~（2+）照射后外周血淋巴细胞染色体畸变进行分析。甲状腺癌150 mCi的放射性碘分别用10 MV X线全身照射1.0戈伊和0.7戈伊，染色体涂染研究表明，估算的照射剂量高于用着丝粒特异性探针进行的FISH研究，因此，染色体涂染法将是检测辐射引起的染色体畸变更为灵敏的方法，随着辐射剂量的增加，染色体畸变率也随之增加，但剂量越大，细胞的畸变率越高，导致细胞周期阻滞，因此很难进行染色体涂染，甚至不可能获得中期染色体。过早的染色体凝聚可以从辐射高度损伤的细胞中产生染色体。事实上，冈田酸或花萼甲素可以在40戈伊辐射的损伤细胞中有效地产生中期样染色体。这种方法可以估计高范围辐射的剂量反应，该方法还可以从细胞中产生染色体，这些细胞的活力太低，无法使用秋水仙胺获得中期染色体。我还开发了使用免疫金银染色法的原位杂交方法。该方法允许在光照下观察标本并永久保存。

To ascertain the irradiation dose for whole body and estimate the subsequent late effect after local irradiation therapy, we performed the fluorescent in situ hybridization (FISH) using centromere specific probe and analyzed chromosomal aberration found in peripheral blood lymphocytes of patients.Patients subjected to local irradiation of 50 Gy of 10 MV X-ray for uterus cervical cancer or administration of 100-150 mCi of radioiodide for thyroid cancer seemed to be irradiated on their whole body 1.0 Gy or 0.7 Gy of 10 MV X-ray, respectively.Chromosome painting study on the same samples revealed that the estimated irradiation dose was higher than that of obtained by the FISH tudy using centromere specific probe.Therefore, chromosome painting will be more sensitive method for detecting chromosomal aberration generated by irradiation.Increasing the dose of irradition generate higher damaged chromosomal aberration.However, the higher the dose, the higher the domages of cells, resulting in arresting of the cell cycle.Therefore it is difficult, or even impossible toobtain metaphase chromosomes.Premature chromosome condensation can produce chromosomes from the highly damged cells by irradiation.In fact, okadaic acid or calyculin A could effectively produce metaphase like chromosomes in damaged cells subjected 40 Gy irradiation.This method allows to estimate the dose response in high range irradiation, which has not been able to do so far.This method also allows to generate chromosomes from the cells which viability is too low to obtain metaphase chromosomes using colcemid.I also developed the in situ hybridization method using immunogold silver staining method.This method allows to observe specimens in light illumination and preserve it permanently.