1998 Fiscal Year Final Research Report Summary
Studies on energy dependency of biological effects of neutrons and risk estimation
| Project/Area Number |
09680530
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
環境影響評価(含放射線生物学)
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| Research Institution | Ibaraki Prefectural University of Health Sciences |
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Principal Investigator |
KUBOTA Nobuo Ibaraki Prefectural University of Health Sciences, Department of Rediological Sciences, Associate Professor, 保健医療学部, 助教授 (20046139)
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| Co-Investigator(Kenkyū-buntansha) |
KOMATSU Kenshi Hiroshima University, Research Institute for Rediation Biology and Medicine, Pro, 原爆放射能医学研究所, 教授 (80124577)
SIZUKI Masao National Institute of Rediological Sciences, Third groop, Researcher, 第3研究グループ, 研究員 (70281673)
INADA Tetsuo Ibaraki Prefectural University of Health Sciences, Department of Rediological Sc, 保健医療学部, 教授 (50114038)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Neutron / Mutation / HPRT / Neutron energy / V79 |
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| Research Abstract |
We have examined the neutron energy dependency of cell killing and mutation induction at hprt locus in Chinese hamster V79 cells. Monoenergetic neutrons at 0.32, 0.57, and 1.2 MeV were generated at the Hiroshima University Radiobiological Research Accelerator (HIRRAC) Facility, and were used to irradiate cells. The variation in RBE with neutron energy for the end points of cell survival and hprt mutation induction was observed. When compared to 137Cs gamma-rays, all neutron energies were more effective at both cell killing and induction of mutation. Over the range of the neutron energies examined, we found that cytotoxicity increased as the energy decreased from 1.2 to 0.32 MeV.In comparison to gamma-rays, RBEs for cell lethality at 10% survival were 5.7, 6.7, and 7.6 for 1.2, 0.57, and 0.32 MeV, respectively. Mutation induction, on the other hand, was highest at 0.57 MeV with a gradual decrease at 1.2 and 0.32 MeV.RBEs for mutation induction were 9.7, 19.4, and 13.9 for 1.2, 0.57, and 0.32 MeVneutrons.
We isolated independent V79 cell mutants at the hprt locus from untreated and neutron-exposed cells and determined the genetic changes underlying the mutation by multiplex polymerase chain reaction (PCR)-based exon deletion analysis. Preliminary results are suggestive of a specific relationship between deletion patern and neutron energy.
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