人外周血淋巴细胞微核分析用于估算离体模拟局部照射剂量的研究

目的：探讨利用人外周血淋巴细胞微核分析估算局部照射剂量的可行性。方法：收集2例人外周血样本，每例血样分为两部分，一部分不照射，另一部分再分成两组分别于1和5 Gy的⁶⁰Co γ射线下离体照射，剂量率为1 Gy/min。将来自同一样本的照射血与未照射血按1∶3或3∶1比例混合以模拟局部照射，共分析8组混合血样中双核淋巴细胞微核（MN）率，利用国际原子能机构（IAEA）推荐的Dolphin's模型推算混合血中受照血的微核率，并采用卫生行业标准（WS/T 178—1999）推荐的剂量效应曲线估算局部照射剂量。结果：各组混合血样MN分布均不符合泊松分布。1 Gy照射组估算的局部剂量与实际照射剂量偏差较大，5 Gy照射组估算的局部剂量与实际照射剂量较接近。结论：离体情况下，MN能较好的用于估算局部照射剂量，且MN可能更适用于较高剂量的估算。

Use of the micronucleus assay to estimate partial radiation exposure dose in vitro

OBJECTIVE： To explore the feasibility of using the micronucleus assay in human peripheral blood lymphocytes in vitro to estimate partial irradiation exposure dose. METHODS： Two human peripheral blood samples were collected and each was divided into 2 parts. One part was not exposed to radiation. The other part was divided further into 2 groups. Therefore，there were a total of 4 groups which were irradiated with 1 and 5 Gy ⁶⁰Co γ rays， respectively， at the dose rate of 1 Gy/min. Subsequently， irradiated blood samples were mixed with non-irradiated ones with ratios of 1∶3 or 3∶1 to simulate partial exposure. These mixed samples were analyzed using the micronucleus (MN) assay. The MN frequencies were used to estimate exposure doses using the Dolphin's model as recommended by the International Atomic Energy Agency (IAEA)，and to determine dose-effect curves as recommended by health industry standards. RESULTS： The observed MN frequencies did not conform to poisson distribution. In addition，the estimated partial dose from the 1 Gy groups deviated from the actual dose，and the estimated partial dose from the 5 Gy groups were close to the actual dose. CONCLUSION： MN can be used to estimate partial exposure doses in vitro. However，the estimates are more reliable for higher partial dose exposure.