2018 Fiscal Year Final Research Report
Analysis of influence of medical radiation exposure on chromosome by CT examination and biological dose evaluation
| Project/Area Number |
16K08970
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Laboratory medicine
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| Research Institution | Fukushima Medical University |
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Principal Investigator |
SAKAI AKIRA 福島県立医科大学, 医学部, 教授 (70284221)
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| Co-Investigator(Kenkyū-buntansha) |
阿部 悠 福島県立医科大学, 医学部, 助教 (00722472)
野地 秀義 福島県立医科大学, 医学部, 准教授 (20347214)
吉田 光明 弘前大学, 被ばく医療総合研究所, 教授 (60182789)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | 生物学的線量評価 / 二動原体染色体 / 転座型染色体 / 低線量被曝 / CT検査 |
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| Outline of Final Research Achievements |
Analyzing the frequency of chromosome aberrations (CAs) such as dicentric chromosomes (Dics) and chromosome translocations (Trs) formation, at the time of radiation exposure (RE) can be used for biological dosimetry methods. We analyzed the effect of RE from CT examination by examining Dics and Trs. Analysis of 12 people showed a significant increase in Dics after a single CT examination, but did not show a significant increase in Trs. Subsequently, analysis of 8 people who underwent three consecutive CT examinations did not show a cumulative increase in the frequencies of Dics or Trs. The frequency of Trs was higher than that of Dics regardless of CT examination.
We then constructed dose-response curves (DRCs) for low- to medium-dose RE using peripheral blood samples from 5 healthy individuals. Aliquots were irradiated with one of eight gamma-ray doses of 1 Gy or less. DRCs showed a large variation between individuals in the frequency of Dics and Trs.
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| Free Research Field |
放射線生物学
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| Academic Significance and Societal Importance of the Research Achievements |
生物学的線量評価方法に二動原体染色体 (Dics) や転座型染色体 (Trs) の形成数を用いた解析方法があるが、低線量被曝の典型であるCT検査時の放射線被曝においてもDicsの増加を認め染色体切断が誘導されていることが示唆された。また安定型染色体であるTrsは、過去の放射線被曝の影響が残るため低線量被爆後の急性期の被曝線量の解析には適していないが、理論的にはTrsとDicsは同じ頻度で形成されるため、CT検査時にはTrsの形成も誘導されていることが推測できる。したがって、これらの解析結果は過剰な医療被曝に対して警鐘を鳴らす1つのエビデンスと考える。
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