Influence of a thiazole derivative on ethanol and thermally oxidized sunflower oil-induced oxidative stress

The present work describes the protective influence of the dendrodoine analogue (DA) [4-amino-5-benzoyl-2-(4-methoxy phenylamino) thiazole] on thermally oxidized sunflower oil and ethanol-induced oxidative stress. Ethanol was fed to animals at a level of 20% [(7.9 g/kg body weight (bw)] and thermally oxidized sunflower oil at a level of 15% (15 mL/100 g feed). Hepatotoxicity was assessed by measuring the activity of plasma aspartate transaminase (AST), alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT), which were elevated in thermally oxidized oil, and ethanol fed rats when compared with normal control rats. Tissue damage was associated with increased lipid peroxidation and disruption in the antioxidant defence mechanism in thermally oxidized oil- and ethanol-fed groups when compared with normal control group. The activity of liver marker enzymes (AST, ALP and GGT) and the level of lipid peroxidation decreased when DA was administered along with ethanol and thermally oxidized oil. The antioxidant status was near normal in DA-administered groups. Thus we propose that DA exerts antioxidant properties by modulating the activity of hepatic marker enzymes, level of lipid peroxidation and antioxidant status.     

激光诱导光动力效应对人癌细胞株及脐血单个核细胞体外作用的比较

目的　研究激光诱导的光动力效应对人癌细胞株的体外杀伤作用及对脐血单个核细胞的影响 ,以探讨自体外周血造血干细胞移植物的体外净化方法。方法　通过MTT法测定观察不同剂量光敏剂 (血卟啉衍生物 ,HPD)经激光照射不同时间后 ,对人白血病细胞株K5 62、乳腺癌细胞株MCF -7及脐血单个核细胞生长抑制作用的影响。结果　单纯光照对 3种细胞均无明显作用 ;单纯加光敏剂对K5 62细胞及MCF -7细胞有一定的抑制生长作用 ;激光照射加光敏剂可显著抑制K5 62细胞及MCF -7细胞的生长 ,且具有时间及浓度依赖性 ,但对脐血单个核细胞则无明显抑制作用。其细胞抑制率依次为K5 62细胞 >MCF -7细胞 >脐血单个核细胞。结论　激光诱导的光动力效应可能为恶性血液病或实体瘤患者的自体外周血造血干细胞移植物体外净化提供简便、有效且经济的方法 ,值得临床推广、应用。     

Photodynamic therapy decreases cancer colonic cell adhesiveness and metastatic potential

Plasma membrane damage induced in various cell targets by hematoporphyrin (HPD) photodynamic therapy (PDT) could modify cancer cell adhesiveness, an important parameter in cancer metastasis. We investigated the effect of HPD or HPD incubation followed by argon laser light on the adhesiveness of progressive (PROb) or regressive (REGb) cancer cells of the same colonic origin but with a different in vivo metastatic potential. Adhesiveness was studied on plastic or endothelial cell monolayers (ECM). In the absence of treatment, both PROb and REGb cells adhered better on plastic than on ECM. HPD alone or HPD-PDT induced toxicity proportional to the HPD dose. HPD-PDT increased the adhesiveness rate of both cell lines on plastic and decreased it on ECM. HPD-PDT of ECM increased adhesiveness, but only at HPD doses causing at least 50% cell death. With HPD treatment alone or HPD-PDT of culture media, there was no significant decrease in cell adhesiveness to ECM. We also studied the effect of HPD or HPD incubation followed by argon laser light on the metastatic potential of cancer cells, which was decreased for PROb with HPD alone or HPD-PDT. Decreased adhesiveness of colonic cancer cells to ECM after HPD-PDT was thus correlated with decreased metastatic potential. REGb cells did not acquire a progressive phenotype either in vitro or in vivo after HPD-PDT. This work was supported by grants (No. 6727 and 6405) from the Association pour la Recherche sur le Cancer     

Influence of humic substances on the toxic effects of cadmium and SDBS to the green alga Scenedesmus obliquus

The joint toxicity of chemicals mixture in the aquatic environment was still not well clear. To clarify the joint toxicity of the mixtures of metals and organic pollutants, as well as the influence of dissolved organic matter (DOM) in field water-body on their toxic effects, we conducted the toxicity tests with cadmium (Cd) and sodium dodecyl benzene sulfonate (SDBS) on Scenedesmus obliquus (S. obliquus) with or without the presence of fulvic acid (FA), a typical of DOM. Our results showed Cd was more toxic to S. obliquus than SDBS, and the effects of fulvic acid on SDBS were greater than Cd. The joint toxicity of Cd and SDBS expressed a synergistic effect on S. obliquus, which was observed to be increased with the presence of FA. Our results gave an example for the joint toxicity investigations of organics and metals, aiding to understanding the toxicity of pollutant mixtures in field water bodies containing DOM.     

藤茶中杨梅素、二氢杨梅素及其乙酰化衍生物在SD大鼠体内药动学研究

目的：建立LC-MS/MS法测定SD大鼠血浆中杨梅素（myricetin,MY）和二氢杨梅素（dihydromyricetin,DMY）的浓度,将其运用到药动学研究,并评价DMY乙酰化衍生物是否改善生物利用度。方法：SD大鼠随机分为4组,分别灌胃DMY （100 mg·kg^-1,相当于9 375.0 μmo·L^-1）的0.5%羧甲基纤维素钠生理盐水溶液,以及等摩尔剂量的DMY-1、DMY-2、MY。于给药前0.0 h和给药后0.08,0.17,0.25,0.33,0.50,0.75,1.0,2.0,4.0,6.0,8.0,12.0 h尾静脉断尾采血200 μL,血浆样品经0.1%甲酸-乙腈沉淀蛋白,内标法定量,DAS3.0和SPSS统计分析得到药动学参数和曲线。结果：低、中、高的质控样品日内、日间精密度RSD均小于10.2%;DMY和MY的基质效应分别为98.3%~105.5%、98.0%~108.1%;萃取回收率分别为99.4%~103.0%、95.0%~99.7%,均符合生物样品分析检测的要求;DMY-2和DMY-1组相比于DMY组,相对生物利用度分别为47.22%,10.70%,表明口服灌胃给药DMY相对生物利用度要高出乙酰化衍生物组。结论：本研究建立测定大鼠血浆中DMY和MY的LC-MS/MS法,具有灵敏度高、准确性高、重复性好等优点,能够满足生物样品分析检测的要求,可应用于MY、DMY及其衍生物的药动学研究,也可为DMY结构修饰和新药开发提供参考依据。     

抑癌基因p15低表达与苯血液毒性相关性研究

目的探索抑癌基因p15低表达与苯血液毒性的关系。方法应用荧光定量PCR方法,检测20名苯中毒工人和17名同期接苯但无苯中毒表现的同工种对照以及19名健康对照外周血抑癌基因p15基因表达水平。结果与对照组比较,p15 mRNA表达水平在苯中毒组及接苯组均显著下调(P<0.01)。随着苯中毒严重程度的增加,p15表达水平显著下调,并有趋势显著性(P<0.01)。p15 mRNA表达水平与白细胞计数及中性粒细胞计数呈显著正相关(r=0.42,P=0.002;r=0.44,P=0.002)。结论抑癌基因p15在慢性苯中毒者中低表达。p15转录抑制与苯的血液毒性密切相关。     

浅议职业性慢性苯中毒诊断现状

近年来申请职业性慢性苯中毒诊断的案例逐年增多,尽管诊断标准不断修订、完善,但实际工作中仍然会经常遇到一些难以解决的问题。对近十年国内的相关文献进行了初步归纳,并结合目前诊断过程中存在的一些疑问,就目前职业性慢性苯中毒诊断现状进行粗浅的分析、探讨。