大豆低聚糖对人胃癌细胞株BGC-823细胞的细胞凋亡和细胞周期的影响

目的通过观察大豆低聚糖对胃癌癌细胞株BGC-823细胞的细胞周期和细胞凋亡的影响,探索乳酸杆菌发酵滤液对胃癌细胞作用的可能机制。方法用光镜和流式细胞仪分析不同浓度大豆低聚糖对BGC-823细胞的凋亡诱导效果;用流式细胞仪分析不同浓度大豆低聚糖对BGC-823细胞细胞周期的影响。结果大豆低聚糖可以诱导BGC-823细胞的凋亡。形态学观察处理后的BGC-823细胞,可见细胞变形,细胞皱缩,体积变小,细胞间隙增大,细胞核固缩。流式细胞仪分析50 mg/ml和100 mg/ml大豆低聚糖作用48 h和72 h BGC-823细胞的凋亡比例,分别为6.76%和7.93%。50 mg/ml大豆低聚糖作用48 h,引起BGC-823细胞G1期阻滞,100 mg/ml大豆低聚糖作用48 h,引起BGC-823细胞出现S期阻滞。结论大豆低聚糖可诱导部分BGC-823细胞凋亡。大豆低聚糖对BGC-823细胞的生长抑制作用在低浓度时可能通过G1期阻滞实现,在高浓度时可能通过S期阻滞实现。     

红车轴草提取物对胃癌BGC-823细胞凋亡的影响

探讨红车轴草(TrifoliumpratenseL)提取物对胃癌细胞株BGC-823的抑制增殖效应及诱导凋亡作用.我们采用不同浓度(50、100、250、500、1000mg/L)红车轴草提取物处理BGC-823细胞,采用四甲基偶氮唑盐(MTT)法检测药物对细胞的抑制作用,倒置显微镜观察细胞的形态学改变;AO/EB染色,荧光显微镜观察细胞凋亡形态;采用DNALadder观察DNA的降解;应用流式细胞仪观察细胞凋亡过程中的细胞周期的变化和细胞凋亡.结果显示在红车轴草提取物的作用下,BGC-823细胞呈凋亡改变,DNA琼脂糖凝胶电泳呈典型的凋亡特征.细胞凋亡的同时,细胞周期阻滞于G2/M期.实验结果表明红车轴草提取物能抑制胃癌BGC-823细胞增殖,能诱导胃癌细胞凋亡.     

无花果枝提取物体外诱导胃癌BGC-823细胞凋亡的研究

为探讨新鲜无花果枝提取物(FBE)对体外培养的人胃癌细胞株BGC-823增殖和凋亡的影响,用不同浓度FBE处理胃癌BGC-823细胞,采用细胞形态学观察,细胞活力测定(MTY法)及免疫组织化学法检测增殖细胞核抗原(PCNA)表达情况来评价FBE对BGC-823细胞体外增殖的影响,应用流式细胞术的膜联蛋白V/碘化丙啶技术(Annexin V/PI法)检测FBE诱导BGC-823细胞体外凋亡的情况.形态学观察发现中高剂量(＞0.5mg/mL)组处理4 h细胞出现明显凋亡,24 h检测到中高剂量(＞0.5 mg/mE)组细胞增殖活力和增殖细胞核抗原表达显著降低(P＜0.05),流式细胞仪检测到FBE处理4 h所有剂量组细胞平均凋亡率(9.76%,10.87%,14.29%,49.67%,71.37%)均高于对照组(6.1%)(P＜0.05或P＜0.01),以上作用效果呈现剂量依赖性.以上结果说明无花果枝提取物能够通过诱导胃癌BGC-823细胞凋亡从而抑制其体外的生长与增殖.     

胃癌细胞TRAIL受体的表达与其对TRAIL敏感性的关系

目的:探讨胃癌细胞表面TRAIL受体表达水平及其与TRAIL敏感性的关系.方法:PI染色、流式细胞仪检测TRAIL诱导BGC-823及SGC-7901细胞的凋亡率,流式细胞仪检测细胞膜表面四种TRAIL受体-R1、R2、R3、R4的表达情况.结果:TRAIL诱导胃癌细胞凋亡具有剂量和时间依赖性,BGC-823较SGC-7901对TRAIL诱导的凋亡更敏感,TRAIL(100μg·L-1)作用24h的细胞凋亡率分别是59.9%、24.3%.死亡受体TRAIL-R1/DR4、TRAIL-R2/DR5在BGC-823细胞膜表面表达的阳性率高达97.87%和99.42%,而在SGC-7901分别为7.03%和95-31%,诱骗受体TRAIL-R3/DcR1、TRAIL-R4/DcR2在两株细胞膜表面极少表达.结论:胃癌细胞对TRAIL诱导凋亡的敏感性差异可能与细胞膜表面死亡受体有关,尤其与DR4的表达有关.     

选择性环氧合酶-2抑制剂联合奥曲肽诱导人胃癌细胞的凋亡

目的探讨选择性环氧合酶-2抑制剂NS-398与奥曲肽联合应用对人胃癌细胞株BGC-823生长、凋亡的影响。方法体外培养BGC-823细胞,分别用NS-398(100μmol/L)与奥曲肽(1μmol/L)单独及联合处理不同时间后,倒置显微镜观察细胞形态学变化;观察生长曲线的变化;流式细胞仪检测细胞凋亡率;实时定量(Real-time)PCR检测COX-2mRNA的表达;Western blot法检测Caspase-3蛋白表达。结果倒置显微镜下,对照组BGC-823细胞生长良好,药物处理后,细胞变小、变圆,悬浮,联合组细胞形态学改变显著强于单纯用药组;药物作用后,细胞生长受抑制,出现负增长,联合组作用明显强于单纯用药组;流式细胞仪检测表明联合用药组诱导BGC-823细胞的凋亡率明显高于单一用药组和对照组(P0.01);各处理组均使BGC-823细胞COX-2mRNA表达下调(P0.05);药物处理后细胞Caspase-3蛋白表达明显增加。结论 NS-398、奥曲肽联合可协同抑制BGC-823细胞生长、增殖,其机制可能与下调COX-2mRNA表达、诱导肿瘤细胞凋亡相关。     

重楼活性单体pp-10通过抑制PI3K/Akt通路诱导人胃癌细胞BGC-823凋亡和自噬

目的:探讨重楼/七叶一枝花(Paris polyphylla)的醇提物单体pp-10诱导人胃癌BGC-823细胞凋亡和自噬及其分子机制。方法:采用MTT法和克隆形成抑制实验观察不同浓度的重楼单体pp-10对人胃癌BGC-823细胞的增殖抑制作用;Hoechst33342染色法检测pp-10作用于人胃癌BGC-823细胞后细胞核形态的改变;Annexin V-FITC/PI双染法检测细胞凋亡;Western blotting检测重楼单体pp-10对细胞凋亡和自噬相关蛋白Caspase-3、Caspase-9、(ADP-核糖)聚合酶(PARP)、Bax、Bcl-2、LC3、P62以及PI3K/Akt信号通路相关蛋白(Akt、p-Akt、m TOR、p-m TOR、P70s6k、p-P70s6k)表达的影响。结果:重楼单体pp-10能显著抑制BGC-823细胞的生长,作用呈时间-效应关系及剂量-效应关系;克隆形成抑制实验表明随着pp-10浓度的增加,细胞克隆形成逐渐减少,与对照组相比有显著差异;在荧光显微镜下观察可见其细胞核固缩、边聚、裂解等细胞凋亡形态学变化;流式细胞术检测显示,随着作用药物浓度的增高,其凋亡率逐渐升高;Western blotting结果表明,随着药物浓度的增加,线粒体相关凋亡信号通路蛋白Caspase9、Caspase3及PARP均出现酶切活化条带,细胞促凋亡蛋白Bax的表达水平增加,抗凋亡蛋白Bcl-2减少,自噬相关蛋白Ⅱ型LC3增加,P62蛋白减少,p-Akt蛋白的表达水平下降,Akt下游蛋白p-m Tor、p-p70S6K表达减少。结论:重楼单体pp-10通过抑制BGC-823细胞增殖,诱导细胞凋亡和自噬,与下调P13K/Akt信号通路有关。     

蛹虫草对人胃癌细胞BGC-823生长抑制与诱导凋亡作用研究

目的研究蛹虫草水提物（the aqueous extract of Cordycep Militaris,AEoCM）对人胃癌细胞（BGC-823）生长抑制与凋亡诱导作用。方法采用不同浓度的AEoCM分别作用于胃癌BGC-823细胞,24、48和72h后,应用倒置相差显微镜观察胃癌细胞的形态变化,四氮甲基唑蓝（MTT）测定细胞生长抑制效应,流式细胞仪（FCM）检测细胞周期变化及凋亡率,免疫组化方法测定NK-k BP65的表达。结果AEoCM能显著抑制BGC-823细胞增殖,且在一定的浓度范围内呈时问和浓度依赖性。形态学观察发现,细胞变暗、皱缩,形状不规则;FCM检测结果显示,G2期的细胞于作用72h后分布显著增加,使细胞阻滞于G2期。0．5g／L AEoCM在24、48和72h凋亡率分别为4．655％、11．039％和19．368％,其凋亡程度与时间呈正相关,免疫组化方法测定NK-k BP65的表达下调。结论AEoCM能明显抑制BGC-823细胞的生长,诱导其细胞凋亡,其诱导细胞凋亡的机制可能与下调NK—k BP65的表达有关。     

靶向survivin的siRNA对胃癌BGC-823细胞增殖的影响

目的探讨干扰RNA沉默生存素（survivin）基因表达对人胃癌BGC-823细胞增殖和凋亡的影响。方法设计并合成3条靶向survivin的小分子干扰RNA（siRNA）,构建表达性干扰RNA质粒（shRNA）——shRNA-survivin-1、shRNA-survivin-2和shRNA-survivin-3,分别转染胃癌BGC-823细胞,实时定量PCR检测干扰RNA沉默survivin mRNA表达效果,Westernblot观察对胃癌BGC-823细胞survivin蛋白质表达的抑制,MTT（四甲基偶氮唑盐）比色法分析检测细胞生长抑制率,流式细胞计数检测各组细胞周期和凋亡率,探讨干扰RNA对胃癌BGC-823细胞生长的影响。结果在体外,shRNA-survivin-1有效沉默人胃癌BGC-823细胞survivin mRNA的表达,使sur-vivin mRNA相对水平明显降低（P〈0.05）,survivin蛋白质表达抑制,72h细胞生长抑制率达74.92%（P〈0.05）,shRNA-survivin-1使G2/M期细胞百分比明显增加,凋亡率显著增加（P〈0.05）。结论 shRNA-survivin-1可以沉默survivin基因的表达,可以显著抑制胃癌BGC-823细胞的增殖,在一定程度上诱导其自发凋亡。本研究为靶向sur-vivin的RNA干扰在胃癌的基因治疗提供了有力的理论依据和技术储备。     

靶向survivin基因的siRNA对姜黄素诱导胃癌细胞凋亡的影响

目的:研究靶向survivin基因的siRNA对胃癌细胞,survivin表达的影响,抑制survivin基因表达对姜黄素诱导胃癌细胞凋亡的影响。方法:通过脂质体将survivinsiRNA导入胃癌细胞株BGC-803,用Real-timePCR和Western-blotting检测转染后细胞内survivin基因表达水平,流式细胞仪和Hochest染色检测细胞凋亡的改变。结果:姜黄素可抑制BGC-803细胞的生长,其生长抑制率和药物浓度与作用时间呈依赖关系;姜黄素作用BGC-803细胞后,survivin蛋白和mRNA表达降低;通过转染survivinsiRNA抑制BGC-803细胞survivin基因的表达能促进姜黄素诱导BGC-803细胞凋亡的作用。结论:靶向抑制survivin基因表达后姜黄素诱导胃癌细胞BGC-803凋亡的作用增强。     

曲格列酮增加Hela细胞的自噬和混合型细胞死亡

[目的]为了研究Troglitazone(Trog)对HeLa细胞自噬和程序性细胞死亡的影响.[方法]利用电镜、荧光显微镜、免疫杂交、流式细胞计数等对经Trog处理后的HeLa细胞进行了细胞发生自噬和死亡情况的观察.[结果] 电镜、荧光显微镜的结果均提示,Trog能够诱导HeLa细胞自噬活动的增加;免疫杂交显示, 该药物能增加自噬相关基因LC3的表达,并于刺激后4 h达到高峰;除了能使细胞凋亡外,Trog也可以造成细胞的坏死.[结论]上述结果表明,曲格列酮可以引起混合型细胞死亡.     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.