@misc{oai:repo.qst.go.jp:00068206,
 author = {Okayasu, Ryuichi and Okada, Maki and Okabe, Atsushi and Uchihori, Yukio and Suzuki, Masao and Takahashi, Sentaro and 岡安 隆一 and 岡田 真希 and 岡部 篤史 and 内堀 幸夫 and 鈴木 雅雄 and 高橋 千太郎},
 month = {Oct},
 note = {We irradiated normal human fibroblasts (HFL III) with carbon ions (290 MeV/u, 70 keV/um) at very low dose (1 mGy total dose) and low dose rate (1 mGy/6 h) and observed the growth kinetics for several months by continuous culturing. The growth of carbon irradiated cells started to slow down much earlier than that of non-irradiated control cells before reaching senescence. In contrast, there was no growth disadvantage in HFL III cells irradiated at the same dose and the dose rate of gamma-rays. The cells irradiated with gamma-rays rather showed a slight delay in the start of senescence. Our theoretical calculations indicate that only one in eighteen cells would be hit by the carbon beams while all the cells were hit by the same dose (rate) of gamma-rays. These data seem to indicate that the accelerated senescence caused by low dose carbon irradiation was a result of by-stander effect. Our measurements of DNA double strand break (DSB) indicator such as gamma-H2AX foci reveal a higher number of foci in carbon irradiated cells than in gamma-irradiated cells at a cell passage near senescence. Taken together, our results suggest that high LET radiation causes different effects than low LET radiation even at very low doses and that the effect of single low dose irradiation can affect the stability of genome many generations after irradiation., 第５２回 Radiation Research Society annual meeting},
 title = {Extreme low dose rate irradiation with heavy ions induces accelerated senescence in primary human cellsions.},
 year = {2005}
}