@inproceedings{oai:jaxa.repo.nii.ac.jp:00013243,
 author = {大西, 武雄 and 高橋, 昭久 and 鈴木, 雅雄 and 鶴岡, 千鶴 and 鈴木, ひろみ and 嶋津, 徹 and 関, 真也 and 橋爪, 藤子 and 永松, 愛子 and 大森, 克徳 and 石岡, 憲昭 and Onishi, Takeo and Takahashi, Akihisa and Su, Xiaoming and Suzuki, Masao and Tsuruoka, Chizuru and Suzuki, Hiromi and Shimazu, Toru and Seki, Masaya and Hashizume, Toko and Nagamatsu, Aiko and Omori, Katsunori and Ishioka, Noriaki},
 book = {宇宙利用シンポジウム, Space Utilization Research: Proceedings of Space Utilization Symposium},
 month = {Feb},
 note = {第26回宇宙利用シンポジウム(2010年1月25日-26日, 宇宙航空研究開発機構宇宙科学研究本部相模原キャンパス), The Twenty-sixth Space Utilization Symposium (January 25-26, 2010: ISAS/JAXA Sagamihara, Japan), To identify DNA damage induced by space radiations such as the high linear energy transfer (LET) particles, phospho-H2AX (gammaH2AX) foci formation was analyzed in human cells frozen in an International Space Station freezer for 133 days. After recovering the frozen sample to the earth, the cells were cultured for 30 min, and then fixed. Here, we show a track of gammaH2AX positive foci in them by immuno-cytochemical methods. It is suggested that space radiations, especially high LET particles, induced DSBs as a track. From the formation of the tracks in nuclei, exposure dose rate was calculated to be 0.7 mSv per day as relatively high-energy space radiations of Fe-ions (500 MeV/u, 200 keV/μm). From the physical dosimetry with CR-39 plastic nuclear track detectors and thermo-luminescent dosimeters, dose rate was 0.5 mSv per day. These values were similar between biological and physical dosimetries. In addition, the aim of this study was to clarify the effect of space radiations on the radio-adaptive response. Two human lymphoblastoid cell lines were used; one cell line bears a wild-type p53 (wtp53) gene, and another cell line bears a mutated p53 (mp53) gene. The frozen cells were kept in spaceflight on Space Shuttle and International Space Station (ISS) freezer for 133 days from Nov 15th, 2008 to Mar 29th, 2009. After the frozen samples were returned to earth, the cells were cultured for 6 h, and then exposed to challenging X-irradiation doses of 1.2 Gy or 2 Gy. Cellular sensitivity, apoptosis and chromosome aberrations were scored using a dye-exclusion assay, Hoechst33342 staining assay, and chromosomal banding techniques, respectively. In the cells exposed to a space environment, all of radio-adaptive responses such as the induction of radio-resistance and the depression of radiation-induced apoptosis, chromosome aberrations and mutant frequencies investigated here were found in wtp53 cells, but not in the mp53 cells. These results confirmed that the cells exposed to a space environment were likely to the exposed cells to radiation in the specific low dose range which can lead to an adaptive response on ground-base experiments, and that the cells preserved an effect from the space-radiation exposure, even at such low doses in space., 形態: カラー図版あり, 共催: 日本学術会議, 著者人数: 12人, Physical characteristics: Original contains color illustrations, joint hosting: The Science Council of Japan, 資料番号: AA0064730096},
 publisher = {宇宙航空研究開発機構宇宙科学研究本部, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)},
 title = {「きぼう」でのRad Gene 宇宙実験報告3},
 volume = {26},
 year = {2010}
}