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1.
本文对正常孕妇、妊娠高血压综合征(PIH)患者和经青心酮(DHAP)治疗的PIH患者等共24例,应用组织化学分析方法观察胎盘血管内皮细胞(VEC)和平滑肌细胞(VSMC)内一氧化氮合酶(NOS)活性的变化。结果表明:正常孕妇胎盘VEC和VSMC内NOS活性较高;PIH胎盘VEC和VSMC内NOS活性明显减弱,并伴有组织和细胞的形态学损伤;经DHAP治疗后的PIH胎盘VEC和VSMC细胞NOS活性较未经DHAP治疗者明显增加,其组织和细胞损伤也减轻。本研究结果提示胎盘内VEC和VSMC细胞的NOS减少可能与PIH的发生和/或发展有关,青心酮治疗PIH的作用可能与DHAP促进胎盘VEC和VSMC内一氧化氮(NO)合成有关。  相似文献   

2.
高产稳产聚羟基烷酸的重组大肠杆菌的构建   总被引:7,自引:0,他引:7  
重组大肠杆菌Escherichia coliHMS174(pTZ18UPHB) 含有携带聚羟基烷酸(PHA) 合成基因( phaCAB)** 的质粒pTZ18UPHB,是很有潜力的PHA 生产菌,但存在着质粒不稳定和不能合成3羟基丁酸(3HB) 与3羟基戊酸(3HV) 共聚物[P(3HBco3HV)] 的缺陷。将RK2 质粒上的par DE 基因引入pTZ18UPHB 构成质粒pJMC2 ,该质粒可以在宿主E.ColiHMS174 中稳定遗传。将培养基中的磷酸盐浓度降至18 m mol/L,发现E.Coli HMS174(pJMC2) 能够以丙酸为前体合成P(3HBco3HV) ,其中3HV 在共聚物中的含量为5 % ~8 % 。在5L自动发酵罐中分批补料培养E.Coli HMS174(pJMC2) ,培养基初始磷酸盐浓度为15 m mol/L,30 h 后每升培养液中干菌体可达42-5 g,P(3HBco3HV) 占干重的70 % ,其中3HV 在共聚物中的含量为4-9 % 。  相似文献   

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新麦草的组织培养及染色体分析   总被引:4,自引:0,他引:4  
新麦草的组织培养及染色体分析孙震晓,夏光敏,陈惠民(山东大学生物系.济南250100)TISSUECULTUREANDCHROMOMEANALYSISOFPsATHYROSACHYSJUNCEA(FISCH.)NEVSKIsunZhen-xiao;x...  相似文献   

4.
用PCR扩增和克隆马立克氏病病毒糖蛋白D基因   总被引:2,自引:0,他引:2  
用PCR技术,从GA株马立克氏病病毒(MDV)感染的成纤维细胞(GEF)基因组DNA中扩增出MDV糖蛋白D(gD)抗原基因片段的约1300bp编码序列,将该pcR扩增的产物于EcoRI和Kpnl位点克隆到pUC18质粒载体中,在以digoxigenin(dig)标记的gDPCR产物作为探针,进行原位杂交初步筛选到阳性重组质粒克隆,再根据酶切分析筛选到含MDVgD基因的重组质粒p18MgD。将p18MgD质粒DNA用dig标记后,在Southernblot中,该探针能识别MDV基因组DNA的BamHI-A克隆中的A片段DNA。酶切位点分析表明,该gD克隆也和已发表的MDV的RBIB株gD一样,不含有EcoRⅠ、HindⅢ、PstⅠ、SmaⅠ、pvuⅡ等酶切位点。证明该重组质粒是MDVgD克隆。  相似文献   

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《SCI》收录的20种重要植物科学期刊蒋悟生(天津师范大学生物系,天津300074)李德森(南开大学生命科学院,天津300071)TWENTYIMPORTANTPLANTSCIENCEJOURNALSCOVEREDBYTHESCIENCECITATI...  相似文献   

6.
梨树三种新害虫BRIEFNOTESONNEWPESTSOFPEAR,PLUMANDPEACHINFUJIANPROVINCETHREENEWPESTSOFPEARYiJiaminZengShuisheng(PlantProteclionSialion...  相似文献   

7.
滇缅斑鸠菊的化学成分   总被引:1,自引:0,他引:1  
滇缅斑鸠菊的化学成分李蓉涛丁智慧丁靖垲(中国科学院昆明植物研究所植物化学开放研究实验室,昆明650204)CHEMICALCONSTITUENTSFROMVERNONIAPARISHILiRongtao,DingZhihui,DingJi...  相似文献   

8.
以鸡传染性法氏囊病病毒内蒙古毒株(IBDV-NM)dsRNA为模板,用RT-PCR法扩增其主要寄主保护抗原VP2基因的全长cDNA,克隆于pUC19的XbaI/KpnI位点,进行了全序列分析。序列比较发现IBDV-NM毒株VP2基因与已报道的其它7个IBDVCJ801bkf、Cu1、PBG98、52/70、002—73、STC及VariantE毒株之间高度同源,其核苷酸序列的同源率为91.6%~96.2%,推测的氨基酸序列的同源率为96.2%~98.6%。IBDV-NM毒株VP2高变异区的第一个亲水区氨基酸序列与CJ801bkf、Cu1、PBG98、52/70、STC、002—73比较,有一个氨基酸差异,第二个亲水区氨基酸序列与上述6个毒株完全相同。而与VariantE比较,两个亲水区内各有两个氨基酸差异。此外,IBDV-NM毒株VP2具有强毒株所特有的7肽保守区:SWSASGS。这些结果表明,IBDV-NM毒株为标准血清Ⅰ型IBDV强毒株。  相似文献   

9.
江豚和白鳍豚雄性生殖系统的解剖学研究   总被引:2,自引:1,他引:1  
王克雄  刘仁俊 《兽类学报》1998,18(1):68-70,59
江豚和白鳍豚雄性生殖系统的解剖学研究ONTHEANATOMYOFTHEMALEGENITALSYSTEMINTHEBAIJI(LIPOTESVEXILLIFER)ANDFINLESSPORPOISE(NEOPHOCAENAPHOCAENOIDES)...  相似文献   

10.
苏北麦田恶性杂草麦家公的生态习性研究   总被引:1,自引:0,他引:1  
钱希 《生态学报》1995,15(4):453-456
苏北麦田恶性杂草麦家公的生态习性研究钱希(江苏省国营黄海农场,响水县,224624)ASTUDYONECOLOGICALHABITSOFBADWEEDSLITHOSPERMUMARVENSEINWHEATFIELDSOFTHENORTHJIANGSU...  相似文献   

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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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
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  相似文献   

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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.  相似文献   

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