Smith Tammy, Escalona Maria, Ryan Terri, Livingston Gordon K, Sanders Jacob T, Balajee Adayabalam S
Cytogenetics Biodosimetry Laboratory, Radiation Emergency Assistance Center and Training Site, Oak Ridge Institute for Science and Education, Oak Ridge Associated Universities, Oak Ridge, Tennessee.
Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee.
J Cell Biochem. 2019 May;120(5):8619-8629. doi: 10.1002/jcb.28150. Epub 2018 Dec 9.
Dicentric chromosome assay (DCA) is routinely used for estimating the absorbed radiation dose in exposed humans. Optimal lymphocyte viability is crucial for reliable dose estimation and most cytogenetic laboratories prefer the receipt of blood samples within 24 to 36 hours after collection. Delays in the shipment/receipt of samples can occur sometimes under certain unforeseen circumstances: (1) Adverse weather conditions, (2) distant location of blood collection sites, and (3) shipping and handling of a large number of samples after radiological/nuclear mass casualty incident(s). To circumvent some of these limitations, we evaluated the suitability of ex vivo irradiated blood samples stored in the presence of phytohemagglutinin (PHA) for 7 days at ambient temperature (22-24°C) for radiation biodosimetry. Blood samples stored in the presence of PHA for up to 7 days showed a higher mitotic index than blood samples stored without PHA. To verify the use of stored blood samples for DCA, frequencies of X-rays induced dicentric chromosomes were analyzed in the blood samples that were cultured either 24 hours after exposure or 7 days later after storage. Our results indicate that storage of ex vivo irradiated blood samples in the presence of PHA at ambient temperature was found optimal for DCA and that the radiation doses estimated by dicentric chromosome frequencies were grossly similar between the fresh and stored blood samples. Our study suggests that reliable and accurate biodosimetry results can be obtained for triage using blood samples stored for up to a week at ambient temperature in the presence of PHA.
双着丝粒染色体分析（DCA）通常用于估计受照人群所吸收的辐射剂量。最佳的淋巴细胞活力对于可靠的剂量估计至关重要，大多数细胞遗传学实验室更倾向于在采集后24至36小时内接收血样。在某些不可预见的情况下，有时会出现样品运输/接收延迟的情况：（1）恶劣天气条件；（2）采血地点距离遥远；（3）在放射性/核大规模伤亡事件后大量样品的运输和处理。为了克服其中一些限制，我们评估了在植物血凝素（PHA）存在下于室温（22 - 24°C）储存7天的体外照射血样用于辐射生物剂量测定的适用性。在PHA存在下储存长达7天的血样比在无PHA情况下储存的血样具有更高的有丝分裂指数。为了验证储存血样用于DCA的情况，我们分析了在暴露后24小时或储存7天后培养的血样中X射线诱导的双着丝粒染色体频率。我们的结果表明，在室温下于PHA存在下储存体外照射血样对于DCA是最佳的，并且新鲜血样和储存血样通过双着丝粒染色体频率估计的辐射剂量大致相似。我们的研究表明，使用在室温下于PHA存在下储存长达一周的血样进行分流，可以获得可靠且准确的生物剂量测定结果。
