食品接触性塑料制品、可再生资源、汽车尾气中含有低浓度铅.铅等重金属体内蓄积严重影响机体健康,但机体长期暴露于铅环境的代谢依然未知.以低剂量含铅细颗粒物暴露为场景,探讨其在大鼠体内的生物转运及体内分布.通过比较每日吸入染毒(7.05±0.83)μg/m3及经口染毒0.42μg/d,连续染毒28 d.结果显示含铅细颗粒物入血的速度比经口途径快,在肺内蓄积浓度达(4.2±0.67)μg/g,与经口染毒组比较有显著统计学差异(P<0.01);排泄方面,吸入含铅细颗粒物以粪便、尿液形式排出为主,与经口染毒组比较具有体内蓄积量大、排泄慢、在股骨和肋骨内蓄积量大的特点.因此,吸入含铅细颗粒物暴露体内蓄积量大,代谢速度慢,暴露危害比经口途径更大.

Objective To explore the ability of computed tomography angiography in the response evaluation of transarterial chemoembolization for HCC. Methods A total of thirty-eight consecutive patients with unresectable HCC received two cycles of TACE. Unenhanced and contrast-enhanced CT examinations of the upper abdomen were executed one week before the first treatment and four weeks after the second treatment. The feeding arteries were reconstructed by maximum intensity projection and volume rendering with the preoperative and postoperative CT data of arterial phase. The change of the tumor feeding artery was described with disappeared,narrowed,unchanged,enlarged,new artery emerged. Tumor response was evaluated according to the modified RECIST. Results Five patients got a CR. Each feeding vessel was well occluded and couldn't be recognized in CTA. Twenty-four patients got a PR. In this group,more than half of their feeding vessels disappeared or narrowed obviously. The rest of nine patients with four lesions got a SD,whose feeding vessel unchanged or narrowed partly. Conclusion The changes of feeding arteries by CTA is a feasible and tangible method for evaluating the treatment response to transarterial chemoembolization therapy for HCC.