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Báo cáo khoa học: "Relative biological effectiveness of fast neutrons for apoptosis in mouse hair follicles"

Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Relative biological effectiveness of fast neutrons for apoptosis in mouse hair follicles | J. Vet. Sci. 2007 8 4 335-340 JOURNAL OF Veterinary Science Relative biological effectiveness of fast neutrons for apoptosis in mouse hair follicles Hae-June Lee1 Sung-Ho Kim2 1Korea Institute of Radiological Medical Science Seoul 139-240 Korea 2College of Veterinary Medicine Chonnam National University Gwangju 500-757 Korea This study compared the effects of high linear energy transfer LET fast neutrons on the induction of apoptosis in the hair follicles of ICR mice with those of low LET 60Co Y-rays. The changes that occurred from 0 to 24 h after exposing the mice to either 2 Gy of Y-rays 2 Gy min or 0.8 Gy of neutrons 94 mGy min 35 MeV were examined. The maximum frequency was found at 12 h y-rays or 8 h neutrons after irradiation. The mice that received 0-8 Gy of Y-rays or 0-1.6 Gy of neutrons were examined 8 h after irradiation. The dose-response curves were analyzed using the best-fit curve model. The dose-response curves were linear-quadratic and a significant relationship was found between the frequency of apoptotic cells and the dose. The morphological findings in the irradiated groups were typical apoptotic fragments in the matrix region of the hair follicle but the spontaneous existence of apoptotic fragments was rarely observed in the control group. In the presence of an apoptosis frequency between 2 and 14 per follicle the relative biological effectiveness values of neutrons in small and large follicles were 2.09 0.30 and 2.15 0.18 respectively. Key words apoptosis biological effectiveness fast neutrons gamma-rays hair follicle Introduction The hair follicle and its hair have long been recognized as potentially useful biological indicators for the quantitative index of radiation injury in nuclear and medical radiation. Hairs are located over much of the body surface and can provide regional information. Therefore the skin and its appendages would appear to offer the only system in which the dose distribution of radiation over the body surface may be .