title: The use of caffeine to assess high dose exposures to ionising radiation by dicentric analysis.
abstract: Dicentric analysis is considered as a 'gold standard' method for biological dosimetry. However, due to the radiation-induced mitotic delay or inability to reach mitosis of heavily damaged cells, the analysis of dicentrics is restricted to doses up to 4-5 Gy. For higher doses, the analysis by premature chromosome condensation technique has been proposed. Here, it is presented a preliminary study is presented in which an alternative method to analyse dicentrics after high dose exposures to ionising radiation (IR) is evaluated. The method is based on the effect of caffeine in preventing the G2/M checkpoint allowing damaged cells to reach mitosis. The results obtained indicate that the co-treatment with Colcemid and caffeine increases significantly increases the mitotic index, and hence allows a more feasible analysis of dicentrics. Moreover in the dose range analysed, from 0 to 15 Gy, the dicentric cell distribution followed the Poisson distribution, and a simulated partial-body exposure has been clearly detected. Overall, the results presented here suggest that caffeine has a great potential to be used for dose-assessment after high dose exposure to IR.
authors.affiliation: Unitat d'Antropologia Biològica, Departament de Biologia Animal,  Biologia Vegetal i Ecologia, Universitat Autònoma de Barcelona, E-08193 Bellaterra,  Spain.
authors.forename: Mónica
authors.initials: M
authors.lastname: Pujol
authors.forename: Roser
authors.initials: R
authors.lastname: Puig
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Caballín
authors.forename: Leonardo
authors.initials: L
authors.lastname: Barrios
authors.forename: Joan-Francesc
authors.initials: JF
authors.lastname: Barquinero
mesh_terms: D001773:Blood Cells / Q000166:cytology / Q000528:radiation effects; D002110:Caffeine / Q000494:pharmacology*; D018929:Cell Culture Techniques; D002503:Centromere / Q000528:radiation effects*; D002869:Chromosome Aberrations / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008940:Mitotic Index; D011829:Radiation Dosage; D011839:Radiation, Ionizing; D011874:Radiometry / Q000379:methods*
chemical_list: D002110:Caffeine