- 著者
- 望月 肇 賀田 恒夫
- 出版者
- 日本放射線影響学会
- 雑誌
- Journal of Radiation Research (ISSN:04493060)
- 巻号頁・発行日
- vol.23, no.3, pp.403-410, 1982-09
- 被引用文献数
- 4
We formerly showed that human placenta contained strong antimutagenic factors working on radiation and chemically induced mutations in bacteria We are actually examining, in several aspects, if these factors might have certain physiological functions in mammals or not. In this communication, we report that our preparations made from the human placenta tissues greatly restore lethal injuries in X-ray-irradiated mice. Three placenta specimens of healthy women were obtained from the Shimada Hospital (Mishima City). Each tissue was first washed with aqueous KCl (0.15 M) solution, homogenized without any supplementation and centrifuged at 14,000 x g for 20 minutes. The supernantant was then treated with 20 μig/ml pronase at 370C for 20 minutes, followed by dialysis overnight in distilled water. The dialysate was then heated in boiling water for 30 minutes to denature proteic constituents and centrifuged at 3000 x g for 20 minutes. The cellular supernatant solution in a total volume of 10 ml was loaded first on a column (2×20 cm) of Amberlite IR-120B resin and the column was eluted with 500 ml of distilled water.
1 0 0 0 Efficiencies of DNA inactivation and mutation induction by tritiated glycerol in bacterial systems.
- 著者
- 定家 義人 井上 正 望月 肇 賀田 恒夫
- 出版者
- Journal of Radiation Research 編集委員会
- 雑誌
- Journal of Radiation Research (ISSN:04493060)
- 巻号頁・発行日
- vol.22, no.4, pp.387-394, 1981
- 被引用文献数
- 2
When spores of Bccillus subtilis were treated in a frozen state with tritiated glycerol of different concentrations (up to 160 μCi/ml), efficiencies of killing and mutation induction per absorption dose were higher in solutions of lower tritium concentrations where low dose-rate β-irradiations were performed. Similarly when transforming DNA of Bacillus subtilis was kept with tritiated glycerol solution of concentrations ranging 0.05-500 μCi/ml at 4°C, efficiency of inactivation of the arginine marker increased strikingly by lowering the tritium concentration. On the other hand, the RBE of DNA-strand scissions of colicin El plasmids exposed to tritiated glycerol of a relatively high concentration (680 μCi/ml) was found to be approximately 1, when compared at the same absorption dose of gamma-irradiation (36 kR/hr) from a <SUP>137</SUP>Cs source.