Characteristics of nucleoplasmic bridges induced by 60Co γ-rays in human peripheral blood lymphocytes

Abstract

Few studies have shown that the yields of ionising-radiation-induced nucleoplasmic bridges (NPBs) in human cells are dose dependent. However, a dose-response curve between the NPB frequency and the absorbed dose of ionising radiation has not yet been established. This study aimed to investigate NPB frequencies in human peripheral blood lymphocytes induced by cobalt-60 (Co) γ-rays and to establish a dose-response curve. Human peripheral blood samples were collected from three healthy males, and some of these samples were irradiated with 0-6 Gy Co γ-rays. A cytokinesis-block micronucleus cytome assay was then carried out to analyse NPBs and micronuclei (MN) in binucleated cells. The remaining blood samples were irradiated with 0, 2 and 5 Gy of γ-rays, and unstable chromosome aberrations (dicentric chromosome, ring chromosome and acentric chromosome fragment) were analysed. The correlation between NPBs and dicentric plus ring chromosome (dic+r) induced by the same γ-ray dose was also analysed. Results showed that the NPB yields among the three subjects at each dose level were not significantly different. NPBs in binucleated cells at all γ-ray doses conformed to Poisson distribution. The dose-response curve of the γ-ray-induced NPB frequencies followed the linear-quadratic model y = (1.39×10)x + (4.94×10)x. A positive correlation was observed between the frequencies of NPB and dic+r, as well as between the frequencies of MN and acentric fragments. Therefore, NPB is an important biomarker of early chromosome damage event induced by ionising radiation.

Screening of Lipids for Early Triage and Dose Estimation after Acute Radiation Exposure in Rat Plasma Based on Targeted Lipidomics Analysis

“…Hence, it is urgent to find a high-throughput biodosimeter for massive population triage and rapid biological dose estimation. Significant efforts have been made to develop sensitive methods for identifying radiation biomarkers and medical countermeasures for the mitigation of radiation effects, consisting of cytogenetic methods (lymphocyte chromosome aberration assay, 2 nucleoplasmic bridge assay, 3 premature chromosome condensation analysis, 4 cytokinesis block micronucleus assay, 2 and fluorescence in situ hybridization 5 ); molecular biological methods, such as γ-H2AX foci, 6 gene expression, 7 protein biomarkers; 8 and biophysical method, that is, electron paramagnetic resonance. 9 However, most of these assays are low-throughput and require a long time and highly trained personnel to perform and interpret the results, which make them difficult to meet the requirement of rapid, high-throughput assessment of radiation exposure doses in the event of radiological accidents.…”