Wu H, Durante M, George K, Yang T C
NASA Johnson Space Center, Radiation Biology Laboratory, Houston, Texas 77058, USA.
Radiat Res. 1997 Nov;148(5 Suppl):S102-7.
Chromosome aberrations induced by high-energy charged particles in normal human lymphocytes and human fibroblasts have been investigated. The charged particles included 250 MeV/nucleon protons, 290 MeV/nucleon carbon ions and 1 GeV/nucleon iron ions. The energies of the charged particles were higher than in most of the studies reported in the literature. Lymphocytes were stimulated to grow immediately after irradiation, while fibroblasts were incubated at 37 degrees C for 24 h for repair. Chromosomes were collected at the first mitosis after irradiation and chromosome aberrations were scored using the fluorescence in situ hybridization (FISH) technique with a whole-chromosome 4 probe. Chromosome aberrations were classified as reciprocal exchanges, incomplete exchanges, deletions and complex exchanges. The relative biological effectiveness (RBE) for each type of aberration was calculated by dividing a dose of 4 Gy by the dose of the charged particles producing the same effect as 4 Gy of gamma rays. Results of this study showed that complex aberrations have the highest RBE for radiation of high linear energy transfer (LET) for human lymphocytes, but for fibroblasts, the greatest effect was for incomplete exchanges. For both lymphocytes and fibroblasts, iron ions induced a similar fraction of aberrant cells.
已对高能带电粒子在正常人淋巴细胞和成纤维细胞中诱导的染色体畸变进行了研究。带电粒子包括250兆电子伏/核子的质子、290兆电子伏/核子的碳离子和1吉电子伏/核子的铁离子。带电粒子的能量高于文献报道的大多数研究中的能量。淋巴细胞在照射后立即被刺激生长，而成纤维细胞在37℃下孵育24小时以进行修复。在照射后的第一次有丝分裂时收集染色体，并使用全染色体4探针的荧光原位杂交（FISH）技术对染色体畸变进行评分。染色体畸变分为相互交换、不完全交换、缺失和复杂交换。通过将4戈瑞的剂量除以产生与4戈瑞γ射线相同效果的带电粒子剂量，计算每种类型畸变的相对生物效能（RBE）。本研究结果表明，对于人淋巴细胞的高线性能量传递（LET）辐射，复杂畸变具有最高的RBE，但对于成纤维细胞，最大影响是不完全交换。对于淋巴细胞和成纤维细胞，铁离子诱导的异常细胞比例相似。
