title: Intra-individual variation in G2 chromosomal radiosensitivity.
abstract: Intra-individual variation in G(2) chromosomal radiosensitivity was examined by repeatedly taking blood samples from two individuals. Two healthy female volunteers provided a total of 44 blood samples, Donor 1 gave 28 samples in four time periods between 2001 and 2006 and Donor 2 gave 16 samples in two of the same time periods. Lymphocytes were cultured for 72 h prior to irradiation with 0.5 Gy, 300 kV X-rays. Colcemid was added 30 min post-irradiation. Cultures were harvested 90 min post-irradiation and analysed for chromatid gaps and breaks. Donor 1 exhibited significant intra-individual variation in G(2) chromosomal radiosensitivity for two of the four time periods. Variation was not significant for Period 1 (13 samples, P = 0.111) and Period 2 (six samples, P = 0.311) but was significant for Period 3 (two samples, P = 0.030) and Period 4 (seven samples, P = 0.005). Significant intra-individual variation was observed for both time periods involving Donor 2, these being Period 2 (nine samples, P = 0.002) and Period 4 (seven samples, P < 0.001). The combined data from all time periods exhibited a significant intra-individual variation for Donor 1 (P < 0.001) and Donor 2 (P < 0.001). These findings led to the conclusion that too much reliance should not be placed on the result from a single sample when assessing individual radiosensitivity status.
authors.affiliation: Westlakes Research Institute, Westlakes Science and Technology Park, Moor Row, Cumbria CA24 3LN, UK. gillian.curwen@gmail.com
authors.forename: Gillian B
authors.initials: GB
authors.lastname: Curwen
authors.forename: Kevin K
authors.initials: KK
authors.lastname: Cadwell
authors.forename: E Janet
authors.initials: EJ
authors.lastname: Tawn
authors.forename: Jeanette F
authors.initials: JF
authors.lastname: Winther
authors.forename: John D
authors.initials: JD
authors.lastname: Boice
mesh_terms: D000328:Adult; D002648:Child; D002869:Chromosome Aberrations / Q000528:radiation effects*; D002877:Chromosomes, Human / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D016195:G2 Phase / Q000235:genetics* / Q000528:radiation effects*; D006801:Humans; D008214:Lymphocytes / Q000528:radiation effects; D011836:Radiation Tolerance / Q000235:genetics* / Q000528:radiation effects*