GSTM潜抑制剂双依他尼酰乙二胺对人耐顺铂卵巢癌细胞COC1/DDP的抗肿瘤活性

为探讨双依他尼酰乙二胺(EDEA)对人耐顺铂卵巢癌细胞(COC1/DDP)的抗肿瘤活性,本实验用CCK-8细胞增殖实验检测顺铂(DDP)及双依他尼酰乙二胺对细胞生长的抑制作用,用流式细胞术检测细胞凋亡率,Western Blot检测细胞内Bcl-2家族凋亡相关蛋白表达,瑞氏染色观察细胞形态。结果显示,EDEA对人正常细胞HEK293、LO2的低毒剂量接近1.2μmol/L,DDP对上述细胞低毒剂量约1.0μmol/L。分别作用COC1/DDP细胞24 h、48 h、72 h后,EDEA的半抑制浓度IC_(50)均为0.67μmol/L,但DDP对应IC_(50)分别为52.9μmol/L、18.1μmol/L和15.2μmol/L。在浓度均为1.0μmol/L时,EDEA作用COC1/DDP细胞48 h后其凋亡率接近44%,而DDP作用此细胞48h后凋亡率仅约4%。与单用1.0μmol/L DDP处理相比,1.0μmol/L EDEA作用48 h后Bcl-2等抗凋亡蛋白下调,Bax等促凋亡蛋白上调,且p-Akt表达被抑制,细胞形态发生凋亡样改变。结论,EDEA对人正常细胞低毒剂量与DDP相当但对COC1/DDP有显著生长抑制作用,且药效远强于相同浓度DDP;EDEA对耐顺铂卵巢癌细胞COC1的生长抑制作用与p-Akt表达抑制和细胞凋亡增强相关。     

毛头鬼伞子实体中甾类化合物的结构鉴定及其抑制肿瘤细胞增殖活性的研究

从毛头鬼伞子实体中分离得到4个甾类化合物,通过波谱分析,分别鉴定为麦角甾醇(1)、啤酒甾醇(2)、麦角甾醇葡萄糖甙(3)和tuberoside(4)。4个化合物均为首次从毛头鬼伞中得到。通过体外细胞毒性筛选试验,结果表明化合物4有较强的抑制人乳腺癌细胞MCF-7和狗肾细胞MDCK增殖的活性,其抑制增殖的IC50值分别为10.9μg/mL(18.4μmol/L)和5.8μg/mL(9.8μmol/L)。化合物3对MCF-7和MDCK的抑制作用则较弱,当其浓度为10.0μg/mL(17.9μmol/L)时,对MCF-7和MDCK的增殖抑制率分别为12.5%和7.5%。     

氯化钴诱导低氧与气体低氧对大鼠原代肺动脉平滑肌细胞增殖作用的比较研究

该研究比较了氯化钴(cobalt chloride, CoCl₂)诱导低氧与气体低氧对大鼠原代肺动脉平滑肌细胞(pulmonary artery smooth muscle cells, PASMCs)增殖及氧化应激的影响。采用不同剂量(25μmol/L、50μmol/L、100μmol/L、200μmol/L、400μmol/L) CoCl₂诱导细胞或将细胞置于低氧培养箱中,通过MTT、CCK-8和EdU检测比较CoCl₂诱导低氧与气体低氧对大鼠原代PASMCs增殖的影响,并通过Western blot、流式细胞术比较CoCl₂诱导低氧与气体低氧对低氧敏感蛋白低氧诱导因子1α(hypoxia inducible factor-1α, HIF-1α)表达量和细胞内活性氧(reactiveoxygenspecies,ROS)含量的影响。结果显示,CoCl₂或气体低氧刺激细胞24 h均可增加PASMCs增殖活力、HIF-1α蛋白表达量和ROS含量。气体低氧下PASMCs增殖活力显著...     

黄白侧耳大米固体发酵次级代谢产物分析

从黄白侧耳Pleurotus cornucopiae大米固体发酵物中分离得到4个苯酞类化合物,2个为新结构化合物:2-(ethoxymethyl)-3,5-diethoxybenzyl acetate(1)、2-(acetoxymethyl)-4,6-dimethoxybenzyl tridecanoate(2),2个为已知化合物:5,7-dimethoxyisobenzofuran-1(3H)-one(3)、4,6-dimethoxyisobenzofuran-1(3H)-one(4)。对化合物进行生物活性评价发现,化合物3、4具有抑制肿瘤细胞HeLa生长活性,IC50值分别为66.2和65.7μmol/L;化合物3和4对LPS诱导的RAW264.7细胞释放NO有抑制作用,IC50值分别为17.2和67.9μmol/L。     

白藜芦醇对猪原代前体脂肪细胞的增殖与分化及Sirt1基因转录表达时序的影响

分别以0μmol/L(对照组)、10μmol/L(低剂量组),20μmol/L(中等剂量组),50μmol/L,100μmol/L(高剂量组)的白藜芦醇(Resveratrol,RES)处理体外培养1~3日龄健康仔猪前体脂肪细胞,采用MTT比色法检测细胞活性及增殖状况;油红O染色化学比色法定量分析细胞内脂肪生成及细胞分化程度;RT-PCR法分析Sirt1(sirtuin1)mRNA表达情况,探讨Sirt1对猪前体脂肪细胞增殖分化的影响及其分子机制。结果表明,脂肪细胞经RES处理后,各组MTT和油红O染色测得的光密度值(OD值)均低于对照组,50μmol/L,100μmol/L组在96~120h作用极显著(P<0.01),与中低剂量组差异显著(P<0.05);以20μmol/L,100μmol/LRES处理细胞后,Sirt1mRNA表达量随细胞分化的进行而逐渐升高,100μmol/L组均显著高于对照组和20μmol/L组(P<0.05)。RES对猪前体脂肪细胞增殖分化均有一定抑制作用,高剂量RES(50μmol/L和100μmol/L)可显著减少细胞内脂肪的合成、抑制脂肪细胞增殖与分化,Sirt1mRNA表达量显著升高可能是RES抑制细胞分化的重要原因之一。     

镍对体外培养内皮细胞的影响

目的:研究不同浓度的镍对体外培养人脐静脉内皮细胞(HUVEC)的影响。方法:用两种镍化合物(NiCl2·6H2O、NiSO4·6H2O)分别制成含Ni(Ⅱ)浓度为1000、500、250、125、62.5μmol/L及31.25μmol/L的溶液,作用于体外培养的HUVEC细胞株,72h后MTT法测试细胞增殖活性,确定NiCl2·6H2O与NiSO4·6H2O的TC50,并分别以TC50的Ni(Ⅱ)作用培养的HUVEC细胞株,MTT法检测不同时间点(24h、48h、72h、96h、120h)的细胞相对增殖活性;2,4-二硝基苯肼法检测作用72h时培养上清液及细胞裂解液中乳酸脱氢酶(LDH)的含量,计算Ni(Ⅱ)化合物作用下细胞LDH的释放率,评价Ni(Ⅱ)对其影响;HE常规染色观察两种镍化合物作用72h后的细胞形态;AnnexinV-FITC/PI双标记流式细胞仪检测细胞凋亡。结果:两种化合物作用HUVEC细胞TC50为125μmol/L,随着浓度的不断增加,细胞毒性增强;同一浓度的Ni(Ⅱ)对细胞活性的影响随着作用时间增加而增强;两种镍化合物对细胞LDH释放率的影响无明显差异(P>0.05);NiSO4·6...     

过氧化氢对内皮祖细胞凋亡相关蛋白表达的影响

目的:比较不同浓度过氧化氢(hydrogen peroxide,H2O2)对人外周血来源的内皮祖细胞(endothelial progenitor cells,EPCs)生存能力的改变及其对凋亡相关蛋白表达的影响。方法:采用密度梯度离心法和差速贴壁法从人外周静脉血中分离培养内皮祖细胞。选取传代后第3代EPCs作为研究对象,以终浓度分别为50μmol/L、100μmol/L、150μmol/L、200μmol/L、300μmol/L和400μmol/L的过氧化氢处理内皮祖细胞12 h,同时设立正常处理对照组。CCK-8法检测各组内皮祖细胞生存能力的差异;Western blot分析各组内皮祖细胞中凋亡相关蛋白Bax、Bcl-2和p53的蛋白表达情况。结果:与对照组相比,在浓度为50μmol/L、100μmol/L和150μmol/L过氧化氢处理组中细胞存活能力逐渐增强,促凋亡蛋白Bax、p53随之下调,抗凋亡蛋白Bcl-2则显著上调;在浓度为200μmol/L、300μmol/L和400μmol/L过氧化氢处理组中细胞生存能力相对于正常对照组逐渐减弱,促凋亡蛋白Bax、p53表达水平逐渐增加,抗凋亡蛋白Bcl-2表达水平下降。结论:过氧化氢对内皮祖细胞存活能力和凋亡相关蛋白Bax、Bcl-2、p53表达的影响均呈双相性变化。     

富马酸二甲酯对斑马鱼胚胎早期发育的影响

为研究富马酸二甲酯对斑马鱼(Danio rerio)胚胎早期发育的影响,选取不同发育阶段的斑马鱼胚胎,用富马酸二甲酯进行染毒处理,观察胚胎形态发育的异常,计算其对不同发育时期胚胎的24 h、48 h半数致死浓度(LC50)和胚胎72 h孵化率,并考察富马酸二甲酯对胚胎血管发育的影响。结果表明,富马酸二甲酯影响斑马鱼胚胎的早期发育,呈剂量依赖性特点,并与开始处理的时间点有关。富马酸二甲酯引起2 hpf(受精后2 h,2 hours post-fertilization)、10 hpf、24 hpf斑马鱼胚胎死亡的24 h LC50值分别为:13.33μmol/L、17.98μmol/L、32.50μmol/L,48 h LC50值分别为:13.31μmol/L、16.35μmol/L、22.50μmol/L;长期低浓度富马酸二甲酯(≥6μmol/L)作用引起胚胎72 h孵化率下降。27.5μmol/L富马酸二甲酯作用后会显著降低胚胎血管内皮生长因子受体2(VEGFR2)的表达水平。     

SDF-1/CXCR4信号通路介导的低浓度过氧化氢对间充质干细胞促增殖、迁移作用及其机制

该文探讨了低浓度过氧化氢(H_2O_2)对骨髓间充质干细胞增殖、迁移及其相关信号通路的影响,阐明了低浓度H_2O_2发挥生物学效应的分子机制,为临床应用提供了可靠的实验证据。通过差速贴壁分离培养小鼠骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)。流式细胞术鉴定第三代BMSCs表面标志物。采用随机数字表法分组,以不同低浓度H_2O_2(0、25、50、100、150、200μmol/L)处理BMSCs 24 h,应用甲氮甲唑蓝(MTT)法检测细胞增殖,流式细胞术检测干细胞表面标志物以及凋亡率,划痕实验和Transwell实验检测H_2O_2对细胞迁移能力的影响。Western blot检测细胞老化相关蛋白质p16和Cyclin D1、基质细胞衍生因子-1(stromal cell-derived factor-1,SDF-1)与其受体CXCR4(CXC chomekine receptor 4)的表达以及相关下游信号通路PI3K/AKT/mTOR关键蛋白质的表达。流式细胞术检测结果显示,BMSCs细胞表面分化抗原CD29、CD44为阳性,CD34、CD45为阴性。MTT检测结果显示,与对照组相比,25和50μmol/L H_2O_2能有效促进BMSCs增殖(P0.05)。划痕实验和Transwell实验检结果显示,50μmol/L H_2O_2处理细胞能促进其迁移能力。流式细胞术检测显示,25、50和100μmol/L H_2O_2对干细胞凋亡无影响,150和200μmol/L H_2O_2则显著促进细胞凋亡(P0.01);25和50μmol/L低浓度H_2O_2处理干细胞能抑制老化相关蛋白质p16表达下降(P0.05,P0.01),相反,细胞周期蛋白Cyclin D1表达则显著升高(P0.05,P0.01),H_2O_2为200μmol/L时,p16表达上调(P0.01),而Cyclin D1下调(P0.01);同样,25~100μmol/L H_2O_2能增强细胞SDF-1和CXCR4的表达(P0.05)以及上调下游信号通路关键蛋白质PI3K、AKT、mTOR的磷酸化水平(P0.05)。结果表明,低浓H_2O_2度通过活化干细胞SDF-1/CXCR4信号轴,活化其下游PI3K/Akt/mTOR信号通路,促进干细胞增殖和迁移。     

右美托咪定对大鼠海马神经元生长发育的影响及其机制

目的:探讨右美托咪定(DEX)对新生大鼠海马神经元发育过程及脑源性神经营养因子(BDNF)-酪氨酸受体激酶B(Trk B)信号通路分子表达的影响。方法:从新生的大鼠分离出海马神经元细胞进行体外培养,将细胞接种于96孔板,实验分为4组(对照组、1μmol/L DEX处理组、5μmol/L DEX处理组、50μmol/L DEX处理组),每组设置6复孔,分别给予不同浓度的右美托咪定1、5和50μmol/L处理,于处理后2、4、6、8、10 d检测细胞活性,于处理后10 d检测细胞凋亡情况、q-PCR检测突触素(SYN)和突触后密度蛋白95(PSD95)的mRNA表达水平,分析BDNF、Trk B及N-甲基-D-天冬氨酸受体(NMDA)蛋白表达情况。结果:与对照组相比,不同剂量DEX处理组的神经元细胞活力无显著差异,1μmol/L和5μmol/L DEX处理组中SYN和PSD95 mRNA的表达和Trk B蛋白均无显著性差异(P>0.05),而50μmol/L DEX处理组中SYN和PSD95 mRNA的表达显著升高(P<0.01),BDNF蛋白表达水平显着上调(P<0.01),p-N-甲基-D-天冬氨酸受体的表达增加(P<0.01)。结论:50μmol/L DEX对大鼠海马神经元有一定的作用,其可能通过上调BDNF的表达和N-甲基-D-天冬氨酸受体的磷酸化水平来实现。     

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.