阿司匹林抑制动脉粥样硬化作用机制的研究进展

目前,临床上常使用阿司匹林进行心血管疾病的一、二级预防.阿司匹林可以非特异性地抑制环氧合酶,进而发挥抗动脉粥样硬化的作用.大量研究表明阿司匹林还可以通过非环氧合酶途径如抗氧化、调节血管舒缩、对炎症因子的转录调控等来发挥预防作用.本文就近年来阿司匹林抑制动脉粥样硬化作用机制方面的研究予以综述.     

聚天冬氨酸-甲硝唑纳米前药制备、表征及抗虫活性的初步研究

实验以聚天冬氨酸(PASP)为载体,以甲硝唑为模型药物,用较温和简便的方法制备了新型聚天冬氨酸-甲硝唑(PASP-MTI)纳米前药．采用红外光谱及核磁氢谱分析、透射电镜观察、激光粒度、透析和紫外分光光度测定、MTT比色、荧光显微镜和流式细胞术等方法,观察到甲硝唑以酯键方式键合于聚天冬氨酸高分子链上．PASP-MTI纳米前药呈球型,平均粒径404.8 nm,载药量30%,体外释药明显延缓;MTT结果显示,PASP-MTI显著提高甲硝唑对滴虫的抑杀作用,经纳米甲硝唑作用后,部分滴虫胞核出现染色质浓集、核固缩、核碎裂等一系列凋亡改变．流式细胞术检测可见凋亡峰,凋亡率由对照组的11.5%上升到纳米前药组的35.69%．上述实验结果表明：PASP是一种非常有潜力的前药载体,制得的新型PASP-MTI纳米前药具有载药量高、缓释和杀虫作用强等特点,可能的杀虫机制除与高聚物纳米前药促吞噬作用有关外,还与诱导滴虫凋亡有关．     

化学发光法测定正常人皮肤纤维母细胞高密度脂蛋白(HDL)受体功能

A cbemiluminescence assay of human skin fibroblasts HDL receptor function was established.HDL3 was labelled with 6(N-(4-amino butyl)~N-ethyl)-amino-2,3-dihydro phthalazine l,4-dione(ABEI) by the carbodiimide(EDC).The labelled compound (HDL3-ABEI) was water soluble and non-toxic.It was stored at -30*********C before use.HDL3 was isolated by sequential ultracentrifugation.The HDL3 obtained was Apo-E-free.After incubation of HDL3 in waterbath at 52**********C for 3 hours, the HDL3 was labelled with ABEI to a ratio of 0.89 m mol ABEI/mmol HDL3.The HDL3-ABEI showed positive immunore action with antibodies of Apo A-********I and Apo A-*******II, indic-eting that the labelled HDL3 still retained its immunological characteristics.The conditions for determination of HDL receptor function of human skin fibroblasts were studied.The optimum quantity of HDL3-ABEI for combination with fibroblasts HDL receptors at 4癈 was 20********ug.The optimum time for combination of HDL3-ABEI with fibroblasts HDL receptors at 4*********C was 1 hour.The amount of HDL required for blocking HDL receptors was 400********ug.The optimum cell number for combination of HDL3-ABEI with HDL receptors was 1**********X105 cells/ml.In the mean time, the decrease in luminescence intensity with the increase in number of cells was observed.Again a high protein concentration would cause inhibition to the assay system.     

东海赤潮高发区沉积物中营养盐再生速率的研究

2001年5月和2002年5月在东海赤潮高发区的4个站位(E4、E5、DB6、DCl0)对沉积物表面分别充氮气和空气进行培养,研究沉积物．水界面营养盐交换通量在不同条件下的变化规律,以及该海域沉积物中营养盐的再生对水体中营养盐的贡献．结果表明,各溶解态营养盐在还原条件下的迁移较为活跃．在距离陆地较近的海域,营养盐一般由水向沉积物中扩散,且距陆地越近,交换通量越大;而在上升流区,营养盐多由沉积物中向水中扩散．东海赤潮高发区沉积物是SiO3^2-的源,对初级生产力的贡献占6％．同时,东海赤潮高发区沉积物是氮、磷营养盐蓄积库．该海域沉积物每年从水体中吸附的DIN、PO4^3-分别占长江输入的5．9％、67％,沉积物一水界面对水体中SiO3^2-的贡献占7．8％．