@misc{oai:repo.qst.go.jp:00069010,
 author = {Kato, Takamitsu and et.al and 加藤 宝光},
 month = {Jul},
 note = {We investigated the alteration of homologous recombination
repair in synchronous CHO cells irradiated with heavy ion particles
(290MeV/n carbon ion, LET: 13keV/lm and 70keV/lm) and Xrays.
The synchronized cell populations were prepared by mitotic
shake-off and sequential harvesting at various time points. Our flow
cytometry analysis revealed that the majority of cells enter S-phase
at 8 hours, and G2-phase at 12 hours after plating. We scored the
number of co-localization sites of gamma-H2AX (DNA double
strand breaks) and Rad51 (homologous recombination repair
protein) foci after 1Gy irradiation. Carbon irradiated cells showed
a significantly higher number of co-localization sites at 30 minutes
after irradiation than X-irradiated cells. We also observed delayed
disappearance of Rad51 foci in carbon irradiated cells up to 2 hours.
Both chromosome- and chromatid-type aberrations were the highest
in high LET carbon(70keV/lm), intermediate in low LET carbon
(13keV/lm), and the lowest in x-irradiated cells. Furthermore, we
observed a significantly increased number of chromatid-type
aberrations in cells irradiated at early S-phase by 70 keV/lm
carbon ions. The cell survival rates by colony formation seem to
reflect the chromosomal data as expected. We did not observe the
resistant peak at late-S phase in cells irradiated with high LET (70
keV/lm) carbon ions. These results may indicate the alteration of
homologous recombination repair after high LET carbon irradiation
lead to various biological effects. Our data are consistent with the
idea of complex type DSB induced by high LET heavy ion
irradiation., International Congress of Radiation Research},
 title = {The effect of heavy-ions on synchronously dividing},
 year = {2007}
}