title: Estimate of the frequency of true incomplete exchanges in human lymphocytes exposed to 1 GeV/u Fe ions in vitro.
abstract: 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.
authors.affiliation: NASA Johnson Space Center, Radiation Biophysics Laboratory, Houston, TX 77058, USA.
authors.forename: H
authors.initials: H
authors.lastname: Wu
authors.forename: K
authors.initials: K
authors.lastname: George
authors.forename: T C
authors.initials: TC
authors.lastname: Yang
mesh_terms: 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
chemical_list: D007501:Iron