去甲斑蝥素通过线粒体信号转导途径诱导人肝癌SMMC-7721细胞凋亡

目的:探讨去甲斑蝥素(NCTD)对人肝癌SMMC-7721细胞凋亡的影响及其机制。方法:分别用MTT和AnnexinⅤ/PI法检测NCTD对人肝癌细胞SMMC-7721的生长抑制率和细胞凋亡率。用流式细胞仪检测线粒体膜电位的变化。应用Western blot方法来分析细胞色素c、caspase-3、AIF、Bcl-2和Bax的表达。结果:NCTD对人肝癌细胞SMMC-7721有生长抑制作用,随浓度升高、时间延长作用增强,呈剂量和时间效应关系。用AnnexinⅤ/PI双染色法检测SMMC-7721细胞,随NCTD的剂量增加,细胞凋亡率也增加,呈剂量依赖性。用流式细胞仪检测细胞膜电位,随NCTD的剂量增加,线粒体膜电位也随之下降。应用Western blot analysis方法检测,NCTD可诱导caspase-3和AIF的活化及线粒体细胞色素c释放到胞浆中。并随NCTD的剂量增加,Bax的表达量上升,而Bcl-2的表达量下降。结论:NCTD能显著抑制SMMC-7721细胞增殖,并可通过内源性线粒体信号转导途径诱导细胞凋亡。     

Nutlin-3 促进肝癌细胞SMMC-7721 发生焦亡的作用

目的:探讨MDM2 拮抗剂Nutlin-3 促进肝癌细胞SMMC-7721 发生焦亡的作用及相关机制。方法:Western blot 检测细胞中活化caspase-1(p20)及IL-1β的表达,LDH 法检测SMMC-7721 细胞焦亡情况,ELISA 检测细胞上清中IL-1β释放情况。结果:Nutlin-3 提高SMMC-7721 细胞活化caspase-1(p20) 及IL-1β的蛋白表达水平。Nutlin-3 处理显著提高了SMMC-7721 细胞培养上清中的LDH 及IL-1β的表达水平(P<0.05)。结论:Nutlin-3 激活了caspase-1,诱导肝癌细胞SMMC- 7721 发生焦亡,并促进IL-1β释放。     

龙牙楤木多糖诱导人肝癌SMMC-7721细胞凋亡机制研究

目的:探讨龙牙楤木多糖(AEPS)对体外培养人肝癌SMMC-7721细胞凋亡的影响,并探讨其可能的作用机制。方法:荧光显微镜观察细胞形态学变化,流式细胞术(FCM)检测SMMC-7721细胞的凋亡率;Western blot检测不同浓度AEPS作用36小时凋亡蛋白survivin、caspase-3及bcl-2的表达情况。结果:与对照组比较,AEPS不同浓度剂量组Hoechst33258/PI荧光染色出现典型的凋亡形态学改变;FCM检测表明SMMC-7721细胞凋亡率各实验组均明显高于对照组(P0.01),且呈时间剂量依赖性;Western blot显示与对照组相比,各实验组AEPS可显著下调SMMC-7721细胞survivin和bcl-2的表达(P0.01),而caspase-3的表达显著增加(P0.01)。结论:AEPS能明显诱导人肝癌SMMC-7721细胞凋亡,其机制可能与改变凋亡相关基因survivin、caspase-3及bcl-2的表达有关。     

MYH9在人肝癌组织中的表达及其对肝细胞系增殖和凋亡的影响

目的探讨非肌肉肌球蛋白重链(MYH9)在肝癌组织中的表达及通过沉默MYH9基因对肝癌细胞系SMMC-7721的增殖及凋亡的影响。方法收集50组人肝癌组织及癌旁组织,选用人肝癌细胞系SMMC-7721和Hep G2及人正常肝细胞系LO2,免疫组织化学方法及Western blot检测肝癌组织及癌旁组织中MYH9蛋白的表达,Western blot检测SMMC-7721、Hep G2及LO2中MYH9蛋白的表达;将MYH9 siRNA转染SMMC-7721,CKK8法及流式细胞术检测沉默MYH9对肝癌细胞增殖及细胞凋亡的影响。结果 MYH9蛋白在肝癌组织中的表达明显高于癌旁(P0.05);MYH9蛋白在SMMC-7721及Hep G2中的表达均明显高于LO2(P0.05);沉默MYH9基因可抑制细胞增殖(P0.001),促进细胞凋亡(P0.05)。结论 MYH9蛋白在肝癌组织的表达显著高于癌旁组织;MYH9低表达能有效抑制肝癌细胞的增殖,促进其凋亡。     

三羟异黄酮诱导人肝癌细胞凋亡及对相关基因的影响

目的探讨三羟异黄酮(genistein)对人肝癌细胞凋亡的诱导作用及其机制。方法将三羟异黄酮作用于体外培养的人肝癌细胞(SMMC-7721),MTT法检测增殖抑制率,光镜下观察凋亡细胞的形态,凝胶电泳分析DNA改变;通过免疫组化技术检测凋亡基因蛋白P53、survivin和caspase-3的表达。结果三羟异黄酮呈浓度和时间依赖性抑制人肝癌细胞的增殖。5mg/L、10mg/L和20mg/L三羟异黄酮作用48h对肝癌细胞的抑制率分别为9·86%、19·13%和25·64%。形态学显示,三羟异黄酮能诱导SMMC-7721细胞凋亡,细胞DNA电泳出现典型梯状条带;且凋亡相关基因蛋白survivin表达明显减少,而P53和caspase-3的表达增加。结论三羟异黄酮能诱导SMMC-7721细胞凋亡,其凋亡机制之一可能是下调survivin基因蛋白表达,增强P53和caspase-3的表达。     

新化合物TDB 通过PI3K / Akt 通路抑制人肝癌SMMC-7721 细胞增殖并诱导其凋亡

目的:观察新化合物TDB抑制人肝癌SMMC-7721细胞增殖并诱导其凋亡的作用及其可能的作用机制。方法:采用不同浓度的TDB处理人肝癌SMMC-7721细胞48 h,以MTT法检测细胞增殖,流式细胞仪检测细胞周期和细胞凋亡,Western blot法检测Bax、Bcl-2、Cleaved Caspase-3、Akt和p-Akt等蛋白的表达情况。结果:TDB能呈浓度依赖性抑制肝癌细胞增殖,阻滞细胞周期于S期,诱导细胞凋亡;同时下调p-Akt、Bcl-2表达,上调Bax、Cleaved Caspase-3表达。结论:TDB具有抑制肝癌细胞增殖、阻滞细胞周期和诱导细胞凋亡作用,其机制可能与抑制肝癌细胞PI3K/Akt通路,改变Bcl-2/Bax间的平衡,激活下游效应型Caspases发挥诱导凋亡作用有关。     

18β-甘草次酸哌嗪衍生物A30抑制SMMC-7721肝癌细胞增殖北大核心CSCD

目的研究18β-甘草次酸(18β-GA)哌嗪衍生物A30抑制肝癌SMMC-7721细胞增殖的机制。方法实验分为对照组、18β-GA组、A30组,采用MTT法检测SMMC-7721细胞增殖,流式细胞术检测SMMC-7721细胞凋亡和细胞周期,Western blot法检测胱天蛋白酶8(caspase-8)和Bcl2蛋白水平。结果 (2~128)μg/m L A30均可抑制SMMC-7721细胞的增殖,呈剂量依赖性。18β-GA和A30均可诱导SMMC-7721细胞凋亡,并且A30处理细胞的凋亡率显著高于18β-GA组。与对照组相比,18β-GA和A30组的G2/M期细胞显著增加,caspase-8蛋白水平均显著升高,而Bcl2水平均显著降低。结论 A30能抑制SMMC-7721细胞增殖,抑制效果强于18β-GA,与降低细胞Bcl2水平和增加caspase-8水平有关。     

2-脱氧-D-葡萄糖与奥沙利铂对人肝癌SMMC-7721细胞增殖及凋亡的影响

目的: 研究糖酵解抑制剂2-脱氧-D-葡萄糖(2-deoxy-D-glucose,2-DG)与奥沙利铂(oxaliplatin,L-OHP)单独及联合应用对人肝癌细胞SMMC-7721增殖及凋亡的影响。方法: 将2-DG及L-OHP单药及联合用药作用于人肝癌细胞SMMC-7721,MTT法检测各组细胞的生长抑制率,并计算两药的协同作用q值,流式细胞仪检测各组细胞周期及凋亡情况,caspase-3试剂盒检测caspase-3活性。结果: 不同浓度的2-DG和L-OHP均可使肝癌细胞增殖受到抑制,并呈时间、浓度依赖性,两药合用后对细胞的增殖抑制作用明显增强(P<0.05)。2-DG可诱导细胞凋亡,使细胞周期阻滞于G₂/M期;与L-OHP合用后细胞凋亡率更高,可阻滞细胞于G₂/M期和S期。Caspase-3活性在两药联合应用时明显增强。结论: 2-DG能有效抑制SMMC-7721细胞生长增殖,并诱导其凋亡;当其与L-OHP联合应用时能增强L-OHP的抗肿瘤作用,其机制可能与增加caspase-3活性有关。     

抗人DR5单抗与阿霉素联合对人肝癌细胞SMMC-7721协同杀伤效应

目的：探讨mDRA-6对肝癌细胞系SMMC-7721致凋亡作用，及阿霉素与mDRA-6联合协同杀伤效应与机制。方法：常规培养肝癌细胞SMMC-7721，流式细胞术检测细胞表面DR5的表达率。Hoechst33258染色观察SMMC-7721细胞形态变化；MTT法检测细胞毒性作用；流式细胞术定量分析凋亡细胞率。结果：（1）mDRA-6能够诱导SMMC-7721细胞凋亡，在1.89μg／ml浓度下可杀伤36％的细胞，增加mDRA-6浓度，凋亡作用无明显增加；（2）SMMC-7721细胞对阿霉素敏感，存在浓度依赖性；（3）阿霉紊与mDRA-6联合对SMMC-7721细胞具有协同杀伤作用，2μg／ml的mDRA-6与40ng/ml的阿霉素联合杀伤印％SMMC-7721，Hoechst 33258染色和AnnexinV／PI染色证实杀伤作用是通过细胞凋亡实现的。结论：mDRA-6能够诱导肝癌细胞SMMC-7721凋亡，阿霉素与mDRA-6联合具有协同作用。     

双氢青蒿素诱导人前列腺癌细胞系PC-3凋亡

目的探讨双氢青蒿素(dihydroartemisinin,DHA)对人前列腺癌细胞系PC-3的凋亡诱导作用,并探讨其可能机制。方法人前列腺癌PC-3细胞经不同浓度(0、25、50和100μmol/L)DHA处理48 h,用FCM法检测各组细胞凋亡率。用荧光定量PCR检测细胞中HSP70 mRNA的表达。用蛋白质印迹法检测细胞中HSP70蛋白、凋亡酶激活因子(Apaf-1)及caspase-3的表达;荧光定量PCR及蛋白质印迹法增加两组,即100μmol/L HSP70抑制剂槲皮素(quercetin)作为阳性药物对照组,以DMSO作为溶剂对照组。结果 DHA能明显诱导PC-3细胞凋亡(P0.05)。不同浓度DHA能明显下调HSP70 mRNA及蛋白表达水平(P0.05),上调Apaf-1及caspase-3蛋白表达水平(P0.05)。结论双氢青蒿素能诱导前列腺癌PC-3细胞凋亡,其作用机制可能是DHA干扰HSP70的表达,促进caspase信号通路中Apaf-1及caspase-3表达。     

Secular change in menarche in women in Madrid

The age at menarche was estimated by recollection in 1617 women between the ages of 18 and 60 in Madrid and a nearby suburb, Pinto. The population of Pinto is working-class and the Madrid group, taken from residential neighbourhoods , belongs to the upper middle class. In both groups we found a diminution in average age at menarche, from 14.04 to 13.02 years in Madrid and from 14.55 to 13.16 years from about 1935 to about 1965 in Pinto. These changes have been more intense in the group which is less well-off economically, where living conditions have varied much more drastically.     

Intestinal helminthiasis in school children in Haiti in 2002

A survey on intestinal helminths in school children was conducted in Haiti in 2002. This first nationwide study involving the entire country was stratified by department according to urban and rural zones using the cluster method. Focusing on elementary school children (n=5792; age range 3 to 20 years), it involved 26 urban and 49 rural schools randomly selected. Stools were preserved in formalin and examined by the Ritchie technique. Thirty-four per cent of stools (1981/5792) tested positive for intestinal helminths with the following parasites identified: Ascaris lumbricoides (27.3%), Trichuris trichiura (7.3%), Necator americanus (3.8%), Hymenolepsis nana (2%), Taenia sp. (0.3%) and Strongyloides stercoralis (0.2%). The helminth prevalence was higher in rural (38.4%) compared to urban areas (30%). There was no significant difference in prevalence by sex and age. The importance of geohelminths changed from one department to another with the highest prevalence found in the Southern department of Grande Anse (73.7%) and the lowest prevalence in the Center department (20.6%). Five out of the country's nine departments had a similar prevalence varying from 25.5% to 28.2%. Intestinal helminthic polyparasitism was observed in a percentage of infested school children comprise between 3.4% and 28.6% according in relation to the geographical area. A program to fight against geohelminths in school children should be initiated as a public health priority. Albendazole is the drug of choice. Frequency of drug distribution should be based on the prevalence of geohelminths in each department.     

Experience in adult population in dengue outbreak in Delhi

A dengue outbreak has recently hit the Indian capital. We studied the clinical profile of adult patients. Five hundred and sixty patients of dengue infection were admitted in a specially created ward according to the criteria laid down by WHO. Haematemesis (28.28%), epistaxis (26.78%) and malena (14.28%) were some of the common presentations. Similarly lymphadenopathy, especially cervical (30.89%), palatal rashes (26.96%) and hepatomegaly (23.75%) were the most commonly encountered findings on physical examination. Most of the cases were of dengue fever with haemorrhage and only 2.5% cases were classified under dengue haemorrhagic fever or dengue shock syndrome. The average hospital stay was 3.4 days but only 9.8 hours in the eleven patients who died, suggesting their late arrival in preterminal situation giving little time for resuscitation. Thrombocytopenia was not a feature and only 12.85% patients had platelet count less than 70,000/cmm. Most of the patients who were admitted with thrombocytopenia, showed normalization in their platelet counts in next few days. Serological examination demonstrated evidence of recent dengue infection in 41.17% patients. Few patients required blood or platelet concentrate transfusion. Eleven patients died, three due to DIC, one of intracranial haemorrhage and seven due to massive gastric haemorrhage. Rest of the patients recovered completely. Thus we can conclude that recent outbreak in Delhi was of dengue fever with haemorrhage and mortality was very low in patients who came early to the hospital.     

Changes in the hypothalamic nuclei in in experimental allergy

Summary In rabbits subjected to prolonged sensitization and in which the Arthus phenomenon was induced there was a marked reaction of the hypothalamic nuclei. Staining by Gomori's method indicated a cellular swelling, loss of granules, and protoplasmic vacuolization in the supraoptic nucleus. There was a considerable increase in the size of the cross-sectional area of the cells. The same effects were much less well shown in the paraventricular nucleus. These results show that marked signs of increased neurosecretion developed in the animals at the height of the Arthus phenomenon.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten Éksperimental'noi biologii i Meditsiny, Vol. 55, No. 4, pp. 110–113, April, 1963.     

Development in in vitro toxicology

There are three principal pressures driving the development of in vitro toxicology: (1) the need for more efficient testing systems to cope with the large number of xenobiotics currently being developed; (2) public pressure to reduce animal experimentation; and (3) a need for a better understanding of the mechanisms of toxicity. Within this, in vitro toxicology is focused on local, systemic, and target-organ toxicity. It is becoming increasingly apparent that a step or decision-tree approach using input of a variety of experimental data (physicochemical properties, biokinetics, cytotoxicity) provides the most efficient system for predicting toxicity. Examples of the use of in vitro toxicity systems for prediction of systemic toxicity and target-organ (liver) toxicity are presented.Originally presented at ECCP 93.