王不留行黄酮苷对过氧化氢和高糖诱导损伤的人脐静脉内皮细胞的保护作用

体外培养人脐静脉内皮细胞,乳酸脱氢酶(LDH)试剂盒评价王不留行黄酮苷孵育24 h后的细胞毒性。先给予13.76、6.88、3.44μmol/L的王不留行黄酮苷和维生素C阳性对照组(浓度为100μmol/L)预孵育12 h后,再分别以H2O2和高糖诱导内皮细胞损伤。SRB法测定细胞活力,试剂盒检测乳酸脱氢酶(LDH)、丙二醛(MDA)、超氧化物歧化酶(SOD)含量。与模型组相比,王不留行黄酮苷13.76、6.88、3.44μmol/L组均可改善H2O2和高糖损伤模型的细胞活力,尤以13.76μmol/L作用最为显著(P0.01);并且王不留行黄酮苷13.76μmol/L显著降低H2O2和高糖损伤组培养液中LDH和MDA释放量,增强细胞内SOD活性。     

ERK1/2信号通路对黄芪苷Ⅳ抗H_2O_2诱导H9c2细胞氧化损伤的作用

目的:研究黄芪苷Ⅳ(AST)是否通过细胞外信号调节激酶1/2(ERK1/2)通路发挥对H2O2诱导的H9c2细胞氧化损伤的保护作用。方法:用200μmol/L的H2O2处理细胞6 h,采用MTT法检测细胞存活率,建立H2O2诱导的H9c2细胞氧化损伤模型;比色法测定细胞培养液中乳酸脱氢酶(LDH)活性、总超氧化物歧化酶(T-SOD)和锰超氧化物歧化酶(Mn-SOD)活力以及丙二醛(MDA)含量;Western blot检测H9c2细胞ERK1/2蛋白的磷酸化水平。结果:在H2O2浓度为200μmol/L作用6 h条件下,细胞存活率降低程度适中,实验结果重复性好,确定后续实验采用200μmol/L H2O2作用6 h建立模型。与H2O2组比较,10 mg/L及20 mg/L AST均显著提高细胞存活率(P<0.01),使细胞培养液中LDH活性显著降低(P<0.01),T-SOD及Mn-SOD活力显著提高(P<0.01),MDA含量显著降低(P<0.01)。10 mg/L及20 mg/L AST均显著增加H2O2损伤的H9c2细胞p-ERK1/2蛋白的表达(P<0.01),当用PD98059(ERK1/2的抑制剂...     

三氧化二砷对人脐静脉内皮细胞凋亡及VCAM-1/ICAM-1 表达的影响

目的:观察三氧化二砷(As2O3)对血管内皮细胞增殖、凋亡及VCAM-1/ICAM-1表达的影响,探讨As2O3对血管内皮细胞增殖生长以及炎症反应的影响。方法:人脐静脉内皮细胞(HUVEC)体外培养,以不同As2O3浓度及时间对其进行干预。采用CCK-8测定细胞增殖活性,流式细胞仪AnnexinⅤ/PI双染法检测细胞的凋亡率,实时荧光定量PCR检测VCAM-1mRNA表达,酶联免疫吸附试验(ELISA)检测细胞间黏附分子(VCAM-1)及血管细胞黏附分子(ICAM-1)的表达情况。结果:当As2O3浓度在3μmol.L-1时HUVEC培养24 h的的凋亡率为(0.134±0.03)%,48 h为(3.305±0.53)%,72 h为(3.748±0.84)%(P<0.05),凋亡率均在一较低水平。当As2O3浓度>3μmol.L-1时HUVEC凋亡率明显增加(P<0.01)。不同浓度As2O3作用HUVEC48 h后检测上清液中ICAM-1与VCAM-1浓度时发现1μmol.L-1时VCAM-1表达即开始增加(123.32±3.78 mmol.L-1,P<0.01),而HUVEC表达ICAM-1含量与对照组相比差异并不明显(38.94±2.59 mmol.L-1,P>0.05),随着As2O3浓度的增加,HUVEC表达ICAM-1/VCAM-1的量均增加但敏感性不同。对照组及(1.0、2.0、3.0、4.0、5.0)μmol.L-1As2O3作用于HUVEC 48 h实时荧光定量PCR法检测VCAM-1mRNA表达量明显增加,与对照组相比实验组的表达量分别为(1.657±0.287,1.858±0.241,2.321±0.280,3.012±0.235,3.508±0.342)(P<0.01)。结论:As2O3可直接降低细胞活性,诱导细胞凋亡,并且呈一定的时间-浓度依赖性。在较低浓度时VCAM-1/ICAM-1的表达在一个相对较低的水平,随着As2O3浓度的逐渐升高,内皮细胞凋亡率增高,VCAM-1/ICAM-1表达增加,并且VCAM-1/ICAM-1对As2O3的敏感性呈现一定的差异性。     

五味子乙素对人肝细胞氧化损伤的保护作用

以过氧化氢(H2O2)处理人肝细胞(L02)后分组,分别以五味子乙素(Schizandrin B,Sch B)15、10和5μmol/L浓度保护细胞6 h后测定细胞存活率及培养基上清液中乳酸脱氢酶(LDH)、谷草转氨酶(AST)、丙二醛(MDA)含量及超氧化物歧化酶(SOD)活性,来考察Sch B对被氧化损伤细胞的保护作用。在H2O2作用下,各组细胞存活率下降,LDH、MDA和AST含量均显著升高,SOD活性显著降低;Sch B处理后LDH、MDA和AST含量均有所降低,SOD活性有所恢复。随着Sch B剂量的增高,这种保护作用表现更加明显。因此,我们认为Sch B可减轻H2O2导致的细胞氧化损伤,能起到一定的保护作用,且该作用呈现一定的剂量依赖性。     

白藜芦醇减轻神经元氧化应激损伤的作用机制研究

目的:观察白藜芦醇(RSV)对过氧化氢(H2O2)所致的海马神经元HT22细胞损伤的保护作用,并探讨超氧化物歧化酶2(Mn-SOD)在其中的作用。方法:采用体外培养HT22小鼠海马神经元细胞系,H2O2作为损伤因素模拟氧化应激损伤。将细胞分为5组,分别为正常培养组(Control)、150μM H2O2损伤组(H2O2)、25μM白藜芦醇保护组(RSV+H2O2)、SOD2-si RNA干扰组(SOD2-si RNA+RSV+H2O2)和乱序RNA组(SC-si RNA+RSV+H2O2),药物暴露24 h后,应用MTT法检测HT22细胞活力、比色法检测乳酸脱氢酶(Lactate Dehydrogenase,LDH)释放量、相差显微镜观测细胞形态。结果:与对照组相比,H2O2组的活力显著下降(P0.05),LDH释放量明显增加(P0.05),细胞形态明显破坏;25μM的RSV显著恢复了HT22细胞的活力、减少了LDH释放、改善了细胞形态,而SOD2-si RNA显著逆转了RSV引起的上述保护作用,乱序RNA(SC-si RNA)未对上述保护作用产生明显影响。结论:白藜芦醇可能通过上调SOD2减轻H2O2对HT22细胞的氧化应激损伤。     

二苯乙烯苷抑制过氧化氢诱导的人脐静脉内皮细胞凋亡

目的:研究二苯乙烯苷(TSG)对过氧化氢(H2O2)诱导人脐静脉内皮细胞(HUVECs)凋亡的保护作用。方法:运用四甲基偶氮唑盐还原法(MTT法)和流式细胞术筛选建立细胞凋亡模型的H2O2合适浓度以及检测不同浓度TSG对H2O2诱导HUVECs的增殖率和凋亡率;Hoechst33258染色观察细胞凋亡形态。结果:MTT及流式法筛选300μmol/L为H2O2作用于细胞的最适凋亡浓度。MTT和流式结果显示,与H2O(2300μmol/L)损伤组比较,10μmol/L与100μmol/LTSG预处理组细胞的增殖率增加(P<0.05),凋亡率显著降低(P<0.01);Hoechst33258染色观察TSG能降低H2O2诱导的细胞凋亡,使细胞凋亡数减少。结论:TSG能抑制H2O2诱导的HUVECs凋亡,从而起到保护血管内皮细胞的作用。     

籽瓜多糖对H_2O_2致PC12细胞氧化损伤的保护作用

本文研究了籽瓜多糖(SWP)对H2O2致PC12细胞氧化应激损伤的影响及其机制。通过建立H2O2诱导PC12细胞氧化损伤模型,CCK-8法测定细胞存活率;硫辛酰胺脱氢酶催化的INT显色反应检测乳酸脱氢酶(LDH)释放量,DCFH-DA检测细胞内ROS;ELISA法检测8-OHd G;JC-1染色检测细胞线粒体膜电位;利用caspase-3可以催化底物Ac-DEVD-p NA的反应检测caspase-3活性;应用caspase-9催化特异性底物Ac-LEHDp NA检测caspase-9活性。结果显示:过氧化氢组与对照组相比,终浓度为500μmol/L H2O2作用细胞24 h后,细胞活力显著下降(P0.01);LDH释放量和细胞内ROS增加(P0.01);8-OHd G含量上升(P0.01);线粒体膜电位下降(P0.01);caspase-3和caspase-9活性增强(P0.01)。与H2O2损伤组相比,不同剂量的SWP预处理后,能显著改善H2O2引起的上述指标的变化(P0.05)。由此得出:SWP对H2O2诱导的PC12细胞的氧化损伤具有一定的保护作用。     

硒对H2O2诱导的人甲状腺细胞凋亡和超微结构改变的影响

目的：观察硒对H2O2诱导的人甲状腺上皮细胞凋亡和超微结构改变的影响。方法：取良性甲状腺腺瘤旁正常组织进行细胞培养。加硒（10^-7mol／L）或不加硒后加入不同浓度H2O2（0～800μmol／L）刺激单层培养的甲状腺细胞,流式细胞术（FCM）检测甲状腺细胞凋亡率并在电镜下观察其超微结构的改变.结果：经过H2O2作用24h的人甲状腺细胞,随H2O2浓度升高,细胞凋亡率逐渐升高;电镜下甲状腺细胞超微结构呈损伤型改变,甚至出现凋亡、死亡。预先加入10^-7mol／L硒可降低细胞凋亡率,可明显减轻亚细胞结构损伤。结论：硒可减轻H2O2诱发的人甲状腺细胞的氧化损伤,拮抗其导致的细胞凋亡。     

过氧化氢预处理对抗氧化应激诱导的PC12细胞凋亡

氧化应激可明显地诱导细胞凋亡。本研究旨在探讨H2O2预处理能否对H2O2诱导的PC12细胞凋亡生产保护作用及ATP敏感性K^ （ATP-sensitive potassinm,KATP）通道在其中的作用。采用PI染色流式细胞仪（flow cytometry, FCM）检测PC12细胞凋亡。结果表明,经10μmol/L H2O2预处理90min的PC12细胞,分别在20、30、50和100μmol/L H2O2作用24h后,其细胞凋亡率明显下降,与未经H2O2的预处理的PC12细胞相比,差异极显著（P＜0.01）,表明H2O2预处理对H2O2诱导PC12细胞凋亡具有保护作用。用10μmol/L的KATP通道激动齐pinacidil(Pin)可显著减少30和50μmol/L H2O2诱导的PC12细胞凋亡,10μmol/L的KATP通道拮抗齐glybenclamide（Gly）则可显著地抑制甚至取消KATP通道激动剂Pin对H2O3诱导PC12细胞凋亡的保护作用,但并不影响H2O2预处理对H2O2诱导PC12细胞凋亡的保护作用;然而,当联合应用H2O2预处理与Pin时,对PC12细胞凋亡的保护作用显大于各自的细胞凋亡作用。提示KATP通道开放不仅对H2O2诱导PC12细胞凋亡具有保护作用,而且与H2O2预处理一起产生抗PC12细胞凋亡的协同作用。但KATP通道开放可能不参与H2O2预处理的适应性保护作用。     

醋酸铅对体外培养大鼠肾小管上皮细胞的毒性损伤

探讨醋酸铅对体外培养的大鼠肾小管上皮细胞系HBZY-1的细胞毒性效应.用不同浓度的醋酸铅(30、40、50 μmol/L)作用HBZY-1细胞24 h、48 h和72 h,采用CellTiter-Glo(R)萤光细胞活性检测盒测定细胞存活情况;用流式细胞仪检测细胞凋亡率.结果显示经30、40、50μmol/L醋酸铅处理...     

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.