Chromosome aberration analysis and the influence o

Authors: Anna Heimers Hein Jürgen Brede Ulrich Giesen Wolfgang Hoffmann

Publish Date: 2006/03/25

Volume: 45, Issue: 1, Pages: 45-54

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Abstract

The influence of high doses of sparsely and densely ionising radiation on the yield of aberrant human peripheral lymphocytes in simulated partialbody exposures was studied by investigating radiationinduced chromosome aberration frequencies namely dicentric and centric ring chromosomes Peripheral blood samples from two volunteers were irradiated with high doses of 200 kV Xrays or neutrons with a mean energy of E n=21 MeV and partialbody exposure was simulated by mixing irradiated and nonirradiated blood from the same two donors in proportions of 25 50 and 75 Lymphocytes were cultured and firstdivision metaphase cells were collected after culture times of 48 56 and 72 h A significant underrepresentation of dicentric and centric ring chromosomes was observed at the three highest doses of Xrays between the different culture times for nearly all proportions After neutron irradiation some significant differences were observed at all doses and all culture times without however revealing any systematic pattern The distribution of dicentric and ring chromosomes showed overdispersion for both radiation types After simulated partialbody exposures with 200 kV Xrays and E n=21 MeV neutrons strong mitotic delays could be observed which depended on both the irradiated volume and the applied dose the smaller the irradiated volume and the higher the dose the higher was the selective advantage of nonirradiated cells For the purpose of biological dosimetry after partial body exposure an extension of the lymphocyte culture time is suggested at least for doses ≥30 Gy of 200 kV Xrays and ≥05 Gy of E n=21 MeV neutrons in order to prevent a systematic underestimation of cytogenetic damageThis study was financed by the German Federal Office of Radiation Protection StSch 4321 The conclusions presented here are those of the authors and do not necessarily represent the official position of the German Federal Minister for the Environment Nature Conservation and Nuclear Safety The authors would like to thank the two volunteers F Berger and G Uelzen for donating considerable quantities of peripheral blood H Schröder for blood sampling L Röhrs for excellent technical assistance E Eggestein H Eggestein O Döhr T Heldt and M Hoffmann for performing neutron measurements and operation of the accelerator at the PTB and H V Boetticher and I Bareth for calibrating the Xray source at the UFT

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