新基因C10orf97参与压力超负荷性心肌肥厚

目的检测新基因C10orf97是否参与压力超负荷型心肌肥厚病程。方法通过缩窄大鼠胸主动脉横支构建压力超负荷诱导的心肌肥厚模型,在缩窄手术后的连续时间点应用血流动力学检测评价心室重构和心功能,应用实时荧光定量PCR法检测心肌肥厚标志基因心房利钠肽和C10orf97的mRNA表达。结果主动脉缩窄手术后,大鼠心脏显著肥厚,心脏体重比逐渐增加,心功能先受损后代偿性增强。心房利钠肽表达显著上调,在缩窄后第15天升高为假手术组40倍。C10orf97基因的表达在缩窄后第2天即显著上调为假手术组的2倍,在第4天降低,随后逐渐上升,第15天时表达量升高为假手术组的3倍。结论C10orf97基因参与了压力超负荷引起的心肌肥厚病程。     

心肌组织特异性Isca1敲除造成新生大鼠心脏结构异常

目的通过对心肌组织特异性Isca1敲除大鼠进行磁共振分析及病理学分析,探究心肌特异性敲除Isca1对大鼠心脏结构影响。方法繁育心肌组织特异性Isca1敲除大鼠,PCR技术鉴定大鼠基因型及基因敲除效率,对新出生0.5d及2.5d心肌组织特异性Isca1敲除大鼠进行核磁共振影像分析,对新出生2.5d心肌组织特异性Isca1敲除大鼠心肌组织进行H&E染色及透射电镜分析。结果心肌组织特异性Isca1敲除大鼠敲除效率大于78%;与野生型相比,0.5d心肌组织特异性Isca1敲除大鼠心脏未见显著扩张;2.5d心肌组织特异性Isca1敲除大鼠心脏右室呈扩张趋势;2.5d心肌组织特异性Isca1敲除大鼠肌纤维排列不齐,出现排列紊乱,无层次或极向,部分心肌纤维出现溶解断裂,肌节和Z线模糊,出现肌膜损伤,线粒体嵴断裂,肿胀明显。结论心肌组织特异性Isca1敲除造成新生大鼠心脏结构异常。     

大鼠不同心肌肥厚模型左心室基因表达谱变化的比较

为了解心肌肥厚时基因表达谱的变化规律,本实验复制了三种大鼠心肌肥厚模型：肾上腹主动脉缩窄(suprarenal abdominal aortic stenosis,SRS)、动静脉瘘(arterial-vein fistula,AVF)和去甲。肾上腺素持续静脉输注(jugular vein infusion of norepinephrine,NEi),并应用组织化学方法和超声心动术检测大鼠心脏结构和功能指标,应用cDNA基因芯片技术检测心脏基因表达水平的变化。SRS和NEi引起大鼠向心性心肌肥厚,AVF引起大鼠离心性心肌肥厚,其中NEi大鼠心肌纤维化明显。对不同心肌肥厚模型间大鼠左心室基因表达谱的变化进行两两比较。结果显示,有部分基因在不同模型中表达水平均发生变化,其中多数基因在两种模型中表达水平改变的方向相同,也有少部分基因在两种模型中表达水平改变方向相反。综合比较三种心肌肥厚模型的基因表达谱,各种模型都有特异的基因表达变化,但是有19个基因在三种心肌肥厚模型中表达水平均发生改变。研究结果有可能成为心肌肥厚的标志性基因或治疗靶点,为心肌肥厚发生机制的深入研究提供了新的线索。     

大鼠心肌肥厚时左心室心房钠尿肽基因的转录

本工作运用ANF放射免疫测定和ANF核酸分子杂交的方法,测定了大鼠腹主动脉部分结扎引起心肌肥厚时血浆ANF及左心室ANF mRNA水平的变化。结果表明,心肌肥厚大鼠的血浆ANF及左心室ANF mRNA水平都明显升高,提示大鼠心肌肥厚可以促进其左心室ANF基因的转录和表达。此外,本工作还证明细胞内钙离子调节剂牛磺酸和血管松弛剂肼苯哒嗪可以分别促进和抑制大鼠心肌肥厚诱导的左心室ANF基因的转录和表达。     

关于心肌肥厚发生机制的探讨

本文综述了近年来心肌肥厚发生机制的若干研究进展,同时探讨了心肌肥厚发生的可能机制。在总结了家族性肥厚性心肌病的线粒体性心肌病中涉及的遗传变异特性以及肥厚心肌的能量代谢和收缩机构变化的基础上,强调能量供应和负荷需求之间平衡关系的破坏可能是心肌肥厚发生的决定因素。另外,还讨论了机械负荷和各种分泌因子在诱发心肌肥厚中的作用和有关的信号传递途径,并指出在心肌肥厚中可能存在某种小分子物质调控其中某些基因的表     

压力负荷型心肌肥厚相关的细胞色素b基因的筛选及克隆

 利用cDNA差减杂交法从压力负荷型心肌肥厚模型形成初期 (3d)的大鼠心肌组织中分离出13个差异性基因片段 ,菌落原位杂交和斑点杂交显示它们在心肌肥厚模型组和对照组中存在表达差异 .经同源性分析后发现其中一个 93bp的cDNA片段与细胞色素b脱辅基蛋白的基因高度同源 ,以其序列设计基因特异性引物应用SMARTRACE (cDNA末端快速扩增法 )技术 ,分离出该基因的全长cDNA ;经克隆、测序后已被GenBank收录 (AF2 95 5 4 5 ) .Northern杂交证实该基因在绑扎腹主动脉 3d的大鼠心脏中高表达 ,说明其在心肌肥厚发生的早期对心功能代偿有一定贡献     

白细胞介素-6缺失减轻压力超负荷诱导的左心室肥厚和心功能障碍

正白细胞介素(interleukin,IL)-6在心肌肥厚性疾病中的作用存在很大争议,最近美国堪萨斯大学的Buddhadeb Dawn课题组利用IL-6基因敲除鼠(Il-6~(-/-))回答了上述争议。在主动脉缩窄术(TAC)诱导的左心室肥厚模型中,Il-6~(-/-)小鼠的左心室肥厚程度和心功能不全较野生鼠明显改善;形态学上,Il-6~(-/-)小鼠心肌纤维化与凋亡明显减少;分子水平上,心肌组织中     

Rett综合征相关基因MeCP2敲除大鼠模型的构建及分析

MeCP2(Methyl CpG binding protein 2)基因突变可导致Rett综合征(Rett syndrome, RTT)。目前已报道的MeCP2敲除小鼠表型与RTT病人症状存在显著差异。为探索MeCP2在脑发育中的作用及其导致RTT的机制,本研究利用CRISPR/Cas9技术构建了MeCP2基因敲除大鼠模型。通过构建靶向敲除MeCP2基因的载体,体外将Cas9 mRNA和sgRNA显微注射到SD大鼠受精卵中,在MeCP2基因exon2中造成移码突变,从而获得MeCP2基因敲除大鼠。利用测序和Western blotting方法鉴定MeCP2敲除大鼠,并对其表型和行为学特征进行分析,发现MeCP2敲除大鼠体重降低,存在焦虑倾向和认知缺陷。本研究成功构建了MeCP2基因敲除大鼠模型,其表型类似人类RTT患者的症状,为后续MeCP2功能研究提供了更好的动物模型。     

一氧化氮在防止心肌肥厚反应中的作用及其机制

本工作从整体和细胞水平探讨一氧化氮（ＮＯ）在防止心肌肥厚反应中的作用及其机制。压力超负荷心肌肥厚大鼠左心室肌ＮＯ含量减少。内源性ＮＯ可能通过非ｃＧＭＰ依赖机制减轻压力超负荷引起的心肌肥厚。在培养的新生大鼠心肌细胞中血管紧张素Ⅱ（ＡⅡ）、内皮素－１（ＥＴ－１）和去甲肾上腺素（ＮＥ）通过各自的受体和偶连的Ｇ蛋白,一方面引起心肌细胞肥大;另一方面抑制一氧化氮合酶（ＮＯＳ）活性和ＮＯ生成。心肌细胞和非心肌     

PI3K和Akt蛋白在异丙肾上腺素所致大鼠心肌肥厚中的表达

目的研究异丙肾上腺素(ISO)致大鼠心肌肥厚中PI3K和Akt在心肌组织中的表达,为探讨心肌肥厚的信号转导机制和逆转心肌肥厚提供形态学资料.方法健康成年SD大鼠20只,随机分为实验组、对照组,每组10只.实验组给予异丙肾上腺素处理.1周后处死大鼠,取心肌组织,常规石蜡切片,HE染色,观察心肌组织的病理变化,测量心肌肥厚指标;免疫组织化学染色和免疫荧光染色,检测p-PI3K和p-Akt的表达及分布.结果实验组大鼠心肌肥厚指标与对照组相比均明显升高;免疫组织化学检测显示,实验组心肌组织p-PI3K和p-Akt蛋白表达面积和平均光密度较对照组高.免疫荧光检测实验组心肌组织p-PI3K和p-Akt蛋白表达较对照组高.结论小剂量持续给予 ISO 能建立大鼠心肌肥厚模型;p-PI3K和p-Akt蛋白表达均与心肌肥厚的发生和发展过程相关,PI3K/Akt信号通路激活,可能是导致心肌肥厚的机制之一.     

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.