title: Cytogenetic dosimetry by micronucleus assay using peripheral blood cells is modified by thyroid hormones.
abstract: Cytokinesis-block micronucleus (CBMN) assay is a convenient and easy method of radiation biodosimetry that uses peripheral blood (PB) cells. However, for micronuclei (MN) frequency induced by ionising radiation, a dose-response relationship in abnormal condition, such as in cancer patients, has not been assessed. To clarify the difference between the dose-response curve generated by the CBMN assay in conditions when thyroid hormone levels were normal and during thyroid hormone withdrawal (THW) prior to (131)I treatment, 12 thyroid cancer patients who underwent thyroidectomy were studied. The collected PB mononuclear cells were exposed to 0.5-3.0 Gy X-ray irradiation. Under normal conditions, dose dependency and independency of MN frequency were observed in 92 % and 8 %, respectively. In contrast, during THW, the number of patients who showed dose independency significantly increased to 42 % in comparison with control. Furthermore, a higher concentration of serum thyroglobulin in dose-independent patients was observed. These results suggest that MN frequency in cytogenetic dosimetry is affected by thyroid hormones.
authors.affiliation: Department of Radiological Life Sciences, Division of Medical Life Sciences, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori, Japan monzens@hirosaki-u.ac.jp.
authors.forename: S
authors.initials: S
authors.lastname: Monzen
authors.affiliation: Department of Radiological Life Sciences, Division of Medical Life Sciences, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Mariya
authors.affiliation: Department of Radiological Life Sciences, Division of Medical Life Sciences, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Nakamura
authors.affiliation: Department of Radiological Life Sciences, Division of Medical Life Sciences, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori, Japan.
authors.forename: C
authors.initials: C
authors.lastname: Kawamura
authors.affiliation: Department of Radiological Life Sciences, Division of Medical Life Sciences, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Taira
authors.affiliation: Department of Radiological Life Sciences, Division of Medical Life Sciences, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki, Aomori, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Chiba
authors.affiliation: Department of Radiology and Radiation Oncology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Takai
mesh_terms: D000328:Adult; D000368:Aged; D001681:Biological Assay / Q000379:methods; D020732:Cytogenetic Analysis / Q000379:methods; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000502:physiology* / Q000528:radiation effects*; D008297:Male; D048629:Micronuclei, Chromosome-Defective / Q000528:radiation effects*; D015162:Micronucleus Tests; D008875:Middle Aged; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013963:Thyroid Hormones / Q000097:blood*; D013964:Thyroid Neoplasms / Q000378:metabolism*
chemical_list: D013963:Thyroid Hormones