tailieunhanh - Báo cáo khoa học: "Comparison of RBE values of high- LET a-particles for the induction of DNA-DSBs, chromosome aberrations and cell reproductive death"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Radiation Oncology cung cấp cho các bạn kiến thức về ngành y đề tài: Comparison of RBE values of high- LET a-particles for the induction of DNA-DSBs, chromosome aberrations and cell reproductive death. | Franken et al. Radiation Oncology 2011 6 64 http content 6 1 64 RADIATION ONCOLOGY RESEARCH Open Access Comparison of RBE values of high- LET a-particles for the induction of DNA-DSBs chromosome aberrations and cell reproductive death 1 1 2 2 12 Nicolaas AP Franken Rosemarie ten Cate Przemek M Krawczyk Jan Stap Jaap Haveman Jacob Aten and Gerrit W Barendsen1 2 Abstract Background Various types of radiation effects in mammalian cells have been studied with the aim to predict the radiosensitivity of tumours and normal tissues . DNA double strand breaks DSB chromosome aberrations and cell reproductive inactivation. However variation in correlations with clinical results has reduced general application. An additional type of information is required for the increasing application of high-LET radiation in cancer therapy the Relative Biological Effectiveness RBE for effects in tumours and normal tissues. Relevant information on RBE values might be derived from studies on cells in culture. Methods To evaluate relationships between DNA-DSB chromosome aberrations and the clinically most relevant effect of cell reproductive death for ionizing radiations of different LET dose-effect relationships were determined for the induction of these effects in cultured SW-1573 cells irradiated with gamma-rays from a Cs-137 source or with a-particles from an Am-241 source. RBE values were derived for these effects. Ionizing radiation induced foci IRIF of DNA repair related proteins indicative of DSB were assessed by counting gamma-H2AX foci. Chromosome aberration frequencies were determined by scoring fragments and translocations using premature chromosome condensation. Cell survival was measured by colony formation assay. Analysis of dose-effect relations was based on the linear-quadratic model. Results Our results show that although both investigated radiation types induce similar numbers of IRIF per absorbed dose only a small fraction of the DSB induced by the .