title: Karyotypes of human lymphocytes exposed to high-energy iron ions.
abstract: Chromosomal aberrations were analyzed using multicolor fluorescence in situ hybridization (mFISH) in human peripheral blood lymphocytes after in vitro exposure to gamma rays or accelerated (56)Fe ions (1 GeV/nucleon, 145 keV/microm) at Brookhaven National Laboratory (Upton, NY). Doses of 0.3 and 3 Gy were used for both radiation types. Chromosomes were prematurely condensed by a phosphatase inhibitor (calyculin A) to avoid the population selection bias observed at metaphase as a result of the severe cell cycle delays induced by heavy ions. A total of 1053 karyotypes (G(2) and M phases) were analyzed in irradiated lymphocytes. Results revealed different distribution patterns for chromosomal aberrations after low- and high-LET radiation exposures: Heavy ions induced a much higher fraction of cells with multiple aberrations, while the majority of the aberrant cells induced by low doses of gamma rays contained a single aberration. The high fraction of complex-type exchanges after heavy ions leads to an overestimation of simple-type asymmetrical interchanges (dicentrics) from analysis of Giemsa-stained samples. However, even after a dose of 3 Gy iron ions, about 30% of the cells presented no complex-type exchanges. The involvement of individual chromosomes in exchanges was similar for densely and sparsely ionizing radiation, and no statistically significant evidence of a nonrandom involvement of specific chromosomes was detected.
authors.affiliation: Dipartimento di Scienze Fisiche, Università Federico II, Napoli, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Durante
authors.forename: K
authors.initials: K
authors.lastname: George
authors.forename: H
authors.initials: H
authors.lastname: Wu
authors.forename: F A
authors.initials: FA
authors.lastname: Cucinotta
mesh_terms: D002869:Chromosome Aberrations / Q000145:classification / Q000187:drug effects* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays / Q000009:adverse effects; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007477:Ions / Q000494:pharmacology; D007501:Iron / Q000494:pharmacology*; D007621:Karyotyping; D008214:Lymphocytes / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D008297:Male
chemical_list: D007477:Ions; D007501:Iron