Dicentric chromosomes and γ-H2AX foci formation in lymphocytes of human blood samples exposed to a CT scanner: a direct comparison of dose response relationships
Dicentric chromosomes and γ-H2AX foci formation in lymphocytes of human blood samples exposed to a CT scanner: a direct comparison of dose response relationships
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DOI：
10.1093/rpd/ncp061
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发表时间：
2009-02-01
影响因子：
1
通讯作者：
Voth, Matthias
中科院分区：
文献类型：
--
作者：
Golfier, Sven;Jost, Gregor;Voth, Matthias
通过诱导健康供体血液样本淋巴细胞中双中心染色体（dicentrics）和γ - h2ax病灶形成的实验，直接评估这两个生物学终点的辐射敏感性。对于0.025至1 Gy剂量水平的计算机断层扫描，获得了双心的线性二次剂量响应关系和γ - h2ax焦点的线性剂量响应关系。双中心的剂量-响应关系系数分别为α = (3.76 +/- 0.29) × 10(-2) Gy（-1）和β = (5.54 +/- 0.45) × 10(-2) Gy(-2)， γ - h2ax焦点的线性系数为（7.38 +/- 0.11）Gy（-1）。研究结果表明，双中心评分和γ - h2ax焦点的显微分析是量化低剂量辐射引起的生物损伤的敏感方法。然而，由于γ - h2ax病灶可以在几小时内部分修复，因此生物损伤存在数天甚至数月，这构成了临床相关终点，只能通过染色体畸变评分来可靠地量化。因此，目前双心或互易位的量化仍然是估计低剂量辐射照射效应的推荐方法（“生物剂量学”）。然而，由于本研究中观察到的γ - h2ax病灶检测的高辐射灵敏度，因此应该进一步研究低线性能量转移辐射质量在健康供体淋巴细胞中产生γ - h2ax病灶的有效性。
Experiments using the induction of dicentric chromosomes (dicentrics) as well as the gamma-H2AX foci formation in lymphocytes of blood samples from a healthy donor were performed to directly evaluate the radiation sensitivity of both biological endpoints. For computed tomography scans at dose levels from 0.025 to 1 Gy, a linear-quadratic dose-response relationship for dicentrics and a linear dose-response relationship for gamma-H2AX foci were obtained. The coefficients of the dose-response relationship for dicentrics are alpha = (3.76 +/- 0.29) x 10(-2) Gy(-1) and beta = (5.54 +/- 0.45) x 10(-2) Gy(-2), the linear coefficient for gamma-H2AX foci is (7.38 +/- 0.11) Gy(-1). The findings indicate that scoring of dicentrics as well as microscopic analysis of gamma-H2AX foci are sensitive methods to quantify a radiation-induced biological damage at low doses. However, since gamma-H2AX foci can be partially repaired within a few hours, biological damages present for days or even months, which constitute the clinically relevant endpoints, can only be quantified reliably by scoring of chromosome aberrations. Thus currently the quantification of dicentrics or reciprocal translocations remains the recommended method for estimating the effect of exposures to low dose levels of radiation ('biological dosimetry'). However, owing to the high radiation sensitivity of the gamma-H2AX foci assay observed in the present study, further investigations on the effectiveness of low-linear energy transfer radiation qualities in producing gamma-H2AX foci in lymphocytes from healthy donors should be performed.