Estimate of the frequency of true incomplete exchanges in human lymphocytes exposed to 1 GeV/u Fe ions in vitro.
OBJECTIVE
To study the frequency of true incomplete exchanges induced by high-LET radiation.


METHODS
Human lymphocytes were exposed to 1 GeV/u Fe ions (LET = 140 keV/microm). Chromosome aberrations were analysed by a fluorescence in situ hybridization using a combination of whole-chromosome-specific probes and human telomere probes. Chromosomes 1, 3 and 4 were investigated.


RESULTS
The percentage of incomplete exchanges was between 23 and 29% if telomere signals were not considered. The percentage decreased to approximately 10% after ruling out false incomplete exchanges containing telomere signals. The final estimation of true incomplete exchanges was <10%.


CONCLUSIONS
Within a degree of uncertainty, the percentage of true incomplete exchanges in 1 GeV/u Fe ion-irradiated human lymphocytes was similar to that induced by gamma rays.
Wu
H
H
NASA Johnson Space Center, Radiation Biophysics Laboratory, Houston, TX 77058, USA.
George
K
K
Yang
T C
TC
D002869:Chromosome Aberrations; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007501:Iron; D018499:Linear Energy Transfer; D008214:Lymphocytes / Q000528:radiation effects* / Q000648:ultrastructure
D007501:Iron