@article{2985724,
    title = "Biodosimetry for high-dose exposures based on dicentric analysis in lymphocytes released from the g2-block by caffeine",
    author = "Karachristou, I. and Karakosta, M. and Pantelias, A. and Hatzi, V. and Pantelias, G. and Thanassoulas, A. and Karaiskos, P. and Dimitriou, P. and Terzoudi, G.I.",
    journal = "Radiation Protection Dosimetry",
    year = "2016",
    volume = "172",
    number = "1-3",
    pages = "230-237",
    publisher = "Oxford University Press",
    issn = "0144-8420, 1742-3406",
    doi = "10.1093/rpd/ncw151",
    keywords = "caffeine, bioassay;  cell culture;  chromosome aberration;  chromosome analysis;  drug effects;  G2 phase cell cycle checkpoint;  genetics;  human;  lymphocyte;  procedures;  radiation dose;  radiation response;  radiometry;  reproducibility;  sensitivity and specificity, Biological Assay;  Caffeine;  Cells, Cultured;  Chromosome Aberrations;  Cytogenetic Analysis;  Dose-Response Relationship, Radiation;  G2 Phase Cell Cycle Checkpoints;  Humans;  Lymphocytes;  Radiation Dosage;  Radiometry;  Reproducibility of Results;  Sensitivity and Specificity",
    abstract = "High-dose assessments using the conventional dicentric assay are essentially restricted to doses up to 5 Gy and only to lymphocytes that succeed to proceed to first post-exposure mitosis. Since G2-checkpoint activation facilitates DNA damage recognition and arrest of damaged cells, caffeine is used to release G2-blocked lymphocytes overcoming the mitotic index and dicentric yield saturation problems, enabling thus dicentric analysis even at high-dose exposures. Using the fluorescence in situ hybridization technique with telomere and centromere peptide nucleic acid probes, the released lymphocytes, identified as metaphases with decondensed chromosomes following 1.5 h caffeine treatment, show increased yield of dicentrics compared to that obtained in lymphocytes that reach metaphase without G2-checkpoint abrogation by caffeine. Here, a 3-h caffeine/ colcemid co-treatment before harvesting at 55 h post-exposure is used so that the dicentric analysis using Giemsa staining is based predominantly on lymphocytes released from the G2-block, increasing thus dicentric yield and enabling construction of a dose-response calibration curve with improved precision of high-dose estimates. © The Author 2016."
}