PMID- 19267556
OWN - NLM
STAT- MEDLINE
DCOM- 20090417
LR  - 20090309
IS  - 0033-7587 (Print)
IS  - 0033-7587 (Linking)
VI  - 171
IP  - 3
DP  - 2009 Mar
TI  - Dose-rate effectiveness for unstable-type chromosome aberrations detected in mice 
      after continuous irradiation with low-dose-rate gamma rays.
PG  - 290-301
LID - 10.1667/RR1238.1 [doi]
AB  - Chronological changes in the chromosome aberration rates of splenocytes from 
      specific-pathogen-free (SPF) mice after continuous and long-term exposure to 
      low-dose-rate gamma rays were studied. Incidences of dicentrics plus centric 
      rings (Dic+Rc), detected by conventional Giemsa staining, and dicentric 
      chromosomes, detected by fluorescence in situ hybridization (Dic by FISH) using a 
      centromere probe, showed an essentially linear increase up to a total accumulated 
      dose of 8000 mGy after irradiation for about 400 days at a low dose rate of 20 
      mGy/day. For comparison, acute high-dose-rate and medium-dose-rate irradiation 
      were performed. The values of the alpha coefficients in the linear regression 
      lines for these unstable-type aberrations decreased as the dose rates were 
      lowered from medium dose rates (200 and 400 mGy/day) to low dose rates (1 and 20 
      mGy/day). The dose and dose-rate effectiveness factor (DDREF), estimated by the 
      ratio of calculated incidences using the best-fit regression lines at a high dose 
      rate (890 mGy/min) and low dose rate (20 mGy/day), was 4.5 for Dic by FISH and 
      5.2 for Dic+Rc, respectively, at the same dose of 100 mGy, while different DDREFs 
      were obtained for different accumulated doses. This is the first study to provide 
      information regarding the effects of long-term exposure to low-dose-rate 
      radiation on chromosomes.
FAU - Tanaka, Kimio
AU  - Tanaka K
AD  - Department of Radiobiology, Institute for Environmental Sciences, Hacchazawa 
      2-121, Takahoko, Rokkasho, Kamikita, Aomori 039-3213, Japan. kmtanaka@ies.or.jp
FAU - Kohda, Atsushi
AU  - Kohda A
FAU - Satoh, Kenichi
AU  - Satoh K
FAU - Toyokawa, Takuo
AU  - Toyokawa T
FAU - Ichinohe, Kazuaki
AU  - Ichinohe K
FAU - Ohtaki, Megu
AU  - Ohtaki M
FAU - Oghiso, Yoichi
AU  - Oghiso Y
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Radiat Res
JT  - Radiation research
JID - 0401245
RN  - 0 (Azure Stains)
SB  - IM
MH  - Aging/genetics
MH  - Animals
MH  - Azure Stains
MH  - Chromosomal Instability/*radiation effects
MH  - DNA Repair/radiation effects
MH  - Dose-Response Relationship, Radiation
MH  - Female
MH  - Gamma Rays/*adverse effects
MH  - In Situ Hybridization, Fluorescence
MH  - Mice
MH  - *Radiation Dosage
MH  - Time Factors
EDAT- 2009/03/10 09:00
MHDA- 2009/04/18 09:00
CRDT- 2009/03/10 09:00
PHST- 2009/03/10 09:00 [entrez]
PHST- 2009/03/10 09:00 [pubmed]
PHST- 2009/04/18 09:00 [medline]
AID - 10.1667/RR1238.1 [doi]
PST - ppublish
SO  - Radiat Res. 2009 Mar;171(3):290-301. doi: 10.1667/RR1238.1.