title: Prematurely condensed chromosome rings after neutron irradiation of human lymphocytes.
abstract: Calibration curves for fission spectrum neutrons and other high LET radiations are scarce in cytogenetic dosimetry and particularly for Prematurely Condensed Chromosome Rings (PCC-ring). Here we analyzed the behavior of the PCC-ring frequency and PCC index after neutron irradiation in a broad dose interval from 1 to 26 Gy. PCC-rings were induced in lymphocytes with Calyculin A. 6455 PCC cells in G1, G2/M and M/A stages were analyzed. The best fitting between the frequency of PCC ring (Y) and the Dose (D) was obtained with the equation Y = (0.059 ± 0.003) D. The saturation of the PCC-ring was observed after around 4 Gy, but it was still possible to analyze cells exposed up to 26 Gy. The distribution of rings by cell follows Poisson or Neyman type distribution for all doses. This PCC-ring dose effect curve can be used in case of accidental overexposure to neutron radiation, allowing a dose assessment in a reliable way. Additionally, the PCC index seems to be well correlated with radiation dose and decrease in a dose dependent manner from 13% in non exposed sample down to 0.2%. This observation allows the possibility to perform a quick classification of victims exposed to high doses of both gamma and neutron radiations. The PCC assay can then be used for both neutron dose estimation up to 4 Gy and for the rapid classification of victims exposed to higher doses. This assay could be included in the multiparametric approach developed to optimize the medical treatment of radiation victims.
authors.affiliation: Centro de Protección e Higiene de las Radiaciones, La Habana, Cuba. ana@cphr.edu.cu
authors.forename: Ana I
authors.initials: AI
authors.lastname: Lamadrid
authors.forename: Jorge E
authors.initials: JE
authors.lastname: González
authors.forename: Omar
authors.initials: O
authors.lastname: García
authors.forename: Philippe
authors.initials: P
authors.lastname: Voisin
authors.forename: Laurence
authors.initials: L
authors.lastname: Roy
mesh_terms: D002453:Cell Cycle / Q000528:radiation effects; D002869:Chromosome Aberrations; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006801:Humans; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000528:radiation effects*; D008387:Marine Toxins; D009502:Neutrons; D010080:Oxazoles / Q000494:pharmacology; D016012:Poisson Distribution; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods; D012303:Ring Chromosomes
chemical_list: D008387:Marine Toxins; D010080:Oxazoles; C059041:calyculin A