A French view on fish painting as a biodosemeter
Sorokine-Durm, I.; Durand, V.; Delbos, M.; Le Baron, L.; Roy, L.; Voisin, P
Radiation Protection Dosimetry 2000, Vol 88, n° 1, 35-44
Fluorescence in situ hybridisation (FISH painting) has enabled the detection of most of the stable radiation-induced chromosome aberrations (translocations, insertions). However, there is still no consensus about the use of FISH techniques for biological dose reconstruction. At IRSN, two coktails of three whole human chromosomes paints were used for both in vitro and in vivo studies (i.e. 2, 4 and 12 for humans and 1, 4, 13 for reshus monkeys). For human analysis, three in vitro dose-effect relationships were established using the same irradiation source (Y rays, 60Co, 0.1 Gy.min-1, 0.5 Gy.min-1 and 1 Gy.min-1). In vitro, the relative importance of complex exchanges was found to be negligible below 3 Gy. A X2 test was applied to the data corresponding to one of the calibration curves (1 Gy.min-1) in order to test the difference between the three chromosome radiosensitivities. No real experimental evidence was found for doubting that aberrations occurred in proportion to their DNA content (p>0.05). In vivo, The temporal persistence of translocations was studied in humans and rhesus monkeys. For human accidental irradiation, less dicentrics than translocations were genreally found when the cytogeneric analysis was carried out after more than 2-4 months. Nevertheless, these translocation valeus rarely exceeded the estimated translocation background level (2.4 x 10-3 per cell). More information about the temporal persistence of translocations was obtained by FISH analysis of highly irradiated rhesus monkeys 4-7 years before blood sampling. The dose estimation based on translocation scoring using FISH triple-painting was underestimated according to the initial physical dose of irradiation. This underestimation appeared smaller when only the complete reciprocal translocations were taken into account for the dose estimates.