[Comparison of cytogenetic response of human lymphocytes to in vivo and in vitro exposure to low-dose gamma rays. Translocations and dicentrics detected by the FISH technique]. / Sravnenie tsitogeneticheskoi reaktsii limfotsitov cheloveka na obluchenie v malykh dozakh gamma-izlucheniia in vivo i in vitro. Translokatsii i ditsentriki, opredeliaemye FISH-metodom.

On peripheral lymphocytes of 5 cancer patients undergone wholebody therapeutic irradiation (at daily dose of 10 cGy up to total dose 50 cGy of 60Co gamma-rays) the dose response of unstable and stable chromosomal exchanges detected by FISH was compared with the dose response of the some aberrations in lymphocytes irradiated in vitro. The dose response fitted well to linear function. For dicentrics the lower slope of dose-response curve was found for in vivo irradiated lymphocytes as compared to the dose-response curve obtained for in vitro irradiated lymphocytes of the same patients. No difference between in vivo and in vitro irradiation of lymphocytes was found for translocations. The frequency of translocations increased faster with the dose than the frequency of dicentrics only in lymphocytes irradiated in vivo.

[Comparison of cytogenic response of human lymphocytes to in vivo and in vitro exposure to low doses of gamma-rays. Unstable chromosomal exchanges detected by FPG techniques]. / Sravnenie tsitogeneticheskoi reaktsii limfotsitov cheloveka na obluchenie v malykh dozakh gamma-izlucheniia in vivo i in vitro. Nestabil'nye khromosomnye obmeny, opredeliaemye FPG-metodom.

On peripheral lymphocytes of eight cancer patients undergone whole-body therapeutic irradiation (at daily dose of 10 cGy up to total dose of 50 cGy of 60Co gamma-rays) the dose-response of unstable chromosome exchanges (dicentrics and centric rings) was studied. This dose response fitted well linear function. The lower slope of dose-response curve was found for in vivo irradiated lymphocytes as compared to the dose response curve obtained for in vitro irradiated lymphocytes of the same patients. This finding seems to provide evidence that in case of protracted irradiation of individuals an absorbed dose could be underestimated if for biological dosimetry an in vitro dose response curve for unstable chromosome aberrations is used as referent one.