Gomolka Maria, Oestreicher Ursula, Rößler Ute, Samaga Daniel, Endesfelder David, Lang Peter, Neumaier Klement, Belka Claus, Niemeyer Markus, Kiechle Marion, Hasbargen Uwe, Hübener Christoph, Kirlum Hans-Joachim, Kulka Ulrike, Rosenberger Albert, Walsh Linda, Baatout Sarah, Kesminiene Ausrele, Lindholm Carita
a Bundesamt für Strahlenschutz, BfS , Ingolstädter Landstrasse 1 , Neuherberg , Germany.
b LMU, Klinik und Poliklinik für Strahlentherapie und Radioonkologie , München , Germany.
Int J Radiat Biol. 2018 Mar;94(3):272-281. doi: 10.1080/09553002.2018.1419302. Epub 2018 Jan 25.
Age dependent radiation sensitivity for DNA damage after in vitro blood exposure by computer tomography (CT) was investigated.
Radiation biomarkers (dicentrics and gammaH2AX) in blood samples of newborns, children under five years and adults after sham exposure (0 mGy), low-dose (41 mGy) and high-dose (978 mGy) in vitro CT exposure were analyzed.
Significantly higher levels of dicentric induction were found for the single and combined newborns/children group compared to adults, by a factor of 1.48 (95% CI 1.30-1.68), after exposure to 978 mGy. Although a significant dose response for damage induction and dose-dependent repair was found, the gammaH2AX assay did not show an age-dependent increase in DNA damage in newborns/children compared to adults. This was the case for the gammaH2AX levels after repair time intervals of 30 minutes and 24 hours, after correcting for the underlying background damage. For the low dose of 41 mGy, the power of the dicentric assay was also not sufficient to detect an age-dependent effect in the sample size investigated.
A 1.5-fold increased level of dicentric aberrations is detected in newborns and children under five years after 1 Gy radiation exposure.
研究计算机断层扫描（CT）体外血液照射后DNA损伤的年龄依赖性辐射敏感性。
分析了新生儿、五岁以下儿童和成人在假照射（0毫戈瑞）、低剂量（41毫戈瑞）和高剂量（978毫戈瑞）体外CT照射后血液样本中的辐射生物标志物（双着丝粒和γH2AX）。
在接受978毫戈瑞照射后，与成人相比，新生儿/儿童单一组和联合组的双着丝粒诱导水平显著更高，高出1.48倍（95%置信区间1.30 - 1.68）。尽管发现了损伤诱导和剂量依赖性修复的显著剂量反应，但与成人相比，γH2AX检测未显示新生儿/儿童DNA损伤存在年龄依赖性增加。在校正潜在背景损伤后，30分钟和24小时修复时间间隔后的γH2AX水平就是这种情况。对于41毫戈瑞的低剂量，双着丝粒检测的效能也不足以在所研究的样本量中检测到年龄依赖性效应。
在1 Gy辐射暴露后，五岁以下新生儿和儿童的双着丝粒畸变水平增加了1.5倍。
