LONG TERM SUPPLEMENTATION OF SE-ENRICHED MALT FOR THE HIGH RISK POPULATION OF LUNG CANCER: INHIBITION OF ULTRAVIOLET LIGHT AND BENZOaPYRENE INDUCED UNSCHEDULED AND SYNTHESIS OF PERIPHERAL LYMPHOCYTES

Se malt cakes containing 300μg selenium were taken up daily to men from high risk area in lung cancer and the influences of Ultraviolet (UV) and Benaopyrene (BαP) induced unscheduled DNA synthesis (UDS) were determined. The Se levels in serum, hair and activity of GSH-px were increased by 89%, 67% and 178%, respectively, after Se-supplementation for half year. In the UV treatment, the ratio of UDS was decreased from the mean values of 2. 47 in the control to 1. 61 (P<0. 05) in the Se-group, In the BaP treatment, furthermore, the elevated Se levels of 78% in serum and 83% in the hair accompanied with 56% high in activity of GSH-px were followed by the Se intake for one year, while the mean value of UDS was reduced from 2. 21 in the control to 1. 47(P< 0. 05) in the group of selenium tested. The blocking effects of UV irradiation and BaP treatment induced UDS of peripheral lymphocytes were showed in the Se-supplementation.

增强UV-B辐射对大豆胚轴DNA损伤、修复和蛋白质含量的影响

大气平流层臭氧层减薄引起到达地表的 UV- B辐射增强。为探讨在增强 UV- B辐射下植物细胞 DNA的损伤修复和蛋白质含量的关系 ,利用 3H- Td R掺入法 ,研究了在 8.2 2 k J/(m2 d)和 12 .4 2 k J/(m2 d) U V- B辐射 (相当于兰州地区大气平流层臭氧减薄约 12 %和 2 0 % )胁迫下 ,大豆胚轴细胞 DNA合成和非按期合成 (UDS)变化 ,并测定了胚轴蛋白质含量变化 ,结果显示 ,UV- B辐射导致 DNA损伤 ,并诱导了 DNA损伤的修复 ,胚轴细胞 UDS效应增强 ,U DS指数增大。低 UV- B辐射强度下 ,胚轴蛋白质含量增加 ,可能是 U V- B诱导了一些与抗性有关的基因表达 ,导致一些新的与抗性有关的蛋白质合成 ;在高强度 UV- B辐射下 ,U DS指数与低强度辐射下无显著差异 (P=0 .0 5 ) ,但蛋白含量较低强度辐射下显著下降 (P=0 .0 5 ) ,说明高强度 UV- B辐射加重了 DNA损伤 ,而修复并未加强 ,并且高强度辐射抑制基因的正常表达和蛋白质合成。这些蛋白质的合成可能与大豆对 UV- B辐射的抗性有关。

白血病患者外周血白细胞非程序DNA合成的研究

以盐酸氮芥和紫外线诱导27例治疗前白血病患者和13例正常人外周血白细胞非程序DNA合成(Unscheduled DNA Synthesis,简称UDS),结果表明:白血病患者外周血白细胞UDS值比正常人显著增高(P<0.001),提示:白血病患者DNA损伤修复功能显著增高。这可能与白血病患者外周血中有较多的白血病细胞有关。