2020 年 85 巻 1 号 p. 71-77
For the assessment of radiation-induced damage in human cells, the frequency of chromosomal aberrations, especially that of dicentric chromosomes in peripheral blood lymphocytes, has been used as the measure in biodosimetry. Considering mass-casualty radiological incidents, it is hoped to preserve part of the blood specimens to be examined at an appropriate time after the medical triage process. In this study, the potential usefulness of lymphocytes cryopreserved for longer than one year was assessed as a pilot study. Seven blood specimens from three healthy donors were experimentally irradiated and cryopreserved for approximately one to five years. All cryopreserved specimens examined were successfully cultured to obtain a sufficient number of mitotic cells for dosimetric analyses. Blood specimens from one donor were intensively examined for the precise comparative analysis of chromosomal aberrations between cultures of cryopreserved specimens and those of freshly prepared specimens. The frequencies of cells with chromosomal aberrations in 1.5-year-cryopreserved specimens after 2-Gy gamma irradiation were not significantly different from those examined using a fresh blood specimen. In this study, we showed the practical significance of the cryopreservation method of peripheral blood lymphocytes that can offer a new strategy of preparedness for triage in mass-casualty radiation incidents/accidents.