Easy biodosimetry for high-dose radiation exposures using drug-induced, prematurely condensed chromosomes.
OBJECTIVE
To propose a practical method of biodosimetry for high-dose estimation.


METHODS
Okadaic acid in the range 100 nM to 500 nM was given for 1-6 h to cultured lymphocytes that had been exposed in the range of 0 Gy to 40 Gy. The frequency of the cells with prematurely condensed chromosomes (PCC) was compared with that of metaphases accumulated by 0.05 microg/ml colcemid. The dose-response relationship of the yield of prematurely condensed ring chromosomes (PCC rings) in the irradiated lymphocytes was examined.


RESULTS
The 0.05 microg/ml colcemid collected few metaphases when lymphocytes were irradiated to over 10 Gy. However, 500 nM okadaic acid produced a substantial number of analysable PCC in lymphocytes that had been exposed in the range of 0 Gy to 40 Gy. After 1 h of treatment, the 500 nM okadaic acid gave the most suitable chromosome morphology for the analysis. PCC rings were narrow, which facilitated their detection in Giemsa-stained preparations. The yield of PCC rings increased dose-dependently up to 20 Gy.


CONCLUSIONS
PCC rings are a more suitable indicator than dicentrics at high doses over 10 Gy. This technique requires no particular equipment or exceptional skill. After a serious radiation accident, it can be easily performed in a short time in most medical facilities to obtain dose information to assist physicians.
Kanda
R
R
Division of Radiobiology and Biodosimetry, National Institute of Radiological Sciences, Chiba, Japan. kanda_r_@nirs.go.jp
Hayata
I
I
Lloyd
D C
DC
D001399:Azure Stains; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D002877:Chromosomes, Human / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007476:Ionophores / Q000494:pharmacology*; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D019319:Okadaic Acid / Q000494:pharmacology*; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods*
D001399:Azure Stains; D007476:Ionophores; D019319:Okadaic Acid