Double tracer studies in healthy human volunteers with stable isotopes of cerium citrate were performed with the aim of investigating the gastro-intestinal absorption of cerium (Ce), its plasma clearance and urinary excretion. In the present work, results of the clearance of Ce in blood plasma are shown after simultaneous intravenous and oral administration of a Ce tracer. Inductively coupled plasma mass spectrometry was used to determine the tracer concentrations in plasma. The results show that about 80% of the injected Ce citrate cleared from the plasma within the 5 mins post-administration. The data obtained are compared to a revised biokinetic model of Ce, which was initially developed by the International Commission on Radiological Protection (ICRP). The measured plasma clearance of Ce citrate was mostly consistent with that predicted by the ICRP biokinetic model. Furthermore, in an effort to quantify the uncertainty of the model prediction, the laboratory animal data on which the ICRP biokinetic Ce model is based, was analyzed. The measured plasma clearance and its uncertainty was also compared to the plasma clearance uncertainty predicted by the model. It was found that the measured plasma clearance during the first 15 min after administration is in a good agreement with the modelled plasma clearance. In general, the measured clearance falls inside the 95% confidence interval predicted by the biokinetic model.

中文翻译：

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人体柠檬酸铈血浆清除率的测量，模型预测和不确定性定量。

对具有稳定柠檬酸铈同位素的健康人类志愿者进行了双示踪剂研究，目的是研究铈（Ce）的胃肠道吸收，血浆清除率和尿排泄量。在本工作中，显示了同时静脉内和口服施用Ce示踪剂后血浆中Ce清除的结果。电感耦合等离子体质谱法用于确定血浆中的示踪剂浓度。结果显示，在给药后5分钟内，约80％的注射的柠檬酸Ce从血浆中清除了。将获得的数据与国际放射防护委员会（ICRP）最初开发的Ce的修正生物动力学模型进行比较。测得的柠檬酸铈的血浆清除率与ICRP生物动力学模型预测的值基本一致。此外，为了量化模型预测的不确定性，分析了ICRP生物动力学Ce模型所基于的实验动物数据。还将测得的血浆清除度及其不确定度与模型预测的血浆清除度不确定度进行了比较。发现给药后前15分钟内测得的血浆清除率与模型血浆清除率非常一致。通常，测得的清除率落在生物动力学模型预测的95％置信区间内。被分析了。还将测得的血浆清除度及其不确定度与模型预测的血浆清除度不确定度进行了比较。发现给药后前15分钟内测得的血浆清除率与模型血浆清除率非常一致。通常，测得的清除率落在生物动力学模型预测的95％置信区间内。被分析了。还将测得的血浆清除度及其不确定度与模型预测的血浆清除度不确定度进行了比较。发现给药后前15分钟内测得的血浆清除率与模型血浆清除率非常一致。通常，测得的清除率落在生物动力学模型预测的95％置信区间内。