糖基化、非糖基化、重组PAI－1功能和性质的比较

对从ＨｅｐＧ２细胞培养液中分离得到植基化和非糖基化ＰＡＩ－１（１型纤溶酶原激活物抑制剂）,以及从ｐＹＺＨＢＩ－６６表达菌中纯化的非糖基化重组ＰＡＩ－１的某些性质和功能进行比较,结果显示,糖基化ＰＡＩ－１对ｔＰＡ（组织型纤溶酶原激活物）有较强的抑制,能较显著地被蛋白质变性剂所激活,对热有较强的稳定性,糖基化与非糖基化ＰＡＩ－１在ｐＨ２．５－９．０的范围内都相当稳定。纤维蛋白原和肝素能明显提高两者对ｔＰＡ的抑制作用。     

纤溶酶原激活物抑制因子—1蛋白分子的结构与功能

纤溶酶原激活物抑制因子－１（ＰＡＩ－１）是组织型纤溶酶原激活物（ｔ－ＰＡ）和尿型纤溶酶原激活物（ｕ－ＰＡ）的特异性抑制剂。对ＰＡＩ－１分子的结构与功能的认识,有助于了解ＰＡＩ－１作用的机理。本综述了近年来对ＰＡＩ－１蛋白分子结构与功能研究的进展,介绍了ＰＡＩ－１分子中一些区域的作用以及影响ＰＡＩ－１抑制活性的一些因子。     

人纤溶酶原激活剂抑制物2型(PAI-2)在Pichia pastoris中的表达

用ＰＣＲ方法从ｐＰＡＩＪ．７中扩增人纤溶酶原激活剂抑制物２型（ＰＡＩ－２）基因,与ｐＰＵＣ１８重组,经限制性内切酶片段分析与核苷酸序列分析,获得全长人ＰＡＩ－２基因．ＰＡＩ－２基因与表达载体ｐＰＩＣ９重组,构建受乙醇氧化酶１基因（ＡＯＸ１）启动子与转录终止区控制的酵母表达质粒,转化ＧＳ１１５宿主菌,经表型筛选和ＰＣＲ扩增筛选阳性克隆,用甲醇诱导表达,重组ＰＡＩ－２以分泌型表达,占分泌总蛋白的３０％,具ＰＡＩ－２抗原性,与低分子量尿激酶形成了抗ＳＤＳ复合物,具抑制纤溶的活性（９１．４ＡＩＵ／ｍｌ）．对培养条件也进行了探讨．     

tPA, uPA, PAI-1和 PAI-2在人和恒河猴胎盘中的原位杂交和荧光免疫定位(英文)

用原位杂交和荧光免疫定位方法研究了组织型（ｔ）和尿激酶型（ｕ）纤溶酶原激活因子ｔＰＡ、ｕＰＡ和相应的抑制因子ＰＡＩ－１、ＰＡＩ－２在人和恒河猴胎盘中的定位和分布。结果表明：（１）激活因子ｔＰＡ、ｕＰＡ（Ｆｉｇ．１＆４）和抑制因子ＰＡＩ－１（Ｆｉｇ．２）、ＰＡＩ－２（Ｆｉｇ．３）一般都在不同程度上定位于两者胎盘的相同部位;（２）它们主要分布在绒毛干和蜕膜的血管壁、 ＲＯｈｒ’ｓ和Ｎｉｔａｂｕｃｈ’ｓ纹间的基盘外绒毛滋养层细胞、滋养壳、蜕膜细胞和腺体细胞。并且发现;ｔＰＡ和它的抑制因子ＰＡＩ－１更明显地定位于邻近母体组织离层界面的区域,而ｕＰＡ和抑制因子ＰＡＩ－１更集中在绒毛滋养层和外绒毛滋养细胞中;（３）激活因子和抑制因子的ｍＲＮＡ和蛋白的定位和分布基本上一致,但是、在绒毛核体滋养层细胞上未发现其ｍＲＮＡ表达,却有很强的免疫荧光的分布;（４）激活因子和抑制因子合成和分布部位与其作用底物,即纤蛋白类分子的产生部位一致;（５）未发现上述分子在人和恒河猴胎盘分布上的不同。上述实验结果说明,在妊娠的各个阶段 ＰＡ和它的抑制因子协同表达,局限在作用范围很小的特定产生底物的区域。它们的相互作用可能是维持正常妊娠所必需。在妊     

纤溶酶原激活剂抑制物2型抑制细胞凋亡的研究进展

纤溶酶原激活剂抑制物２型（ＰＡＩ－２）是一种多功能蛋白质,除了能有效抑制尿激酶（ｕＰＡ）和双链组织型纤溶酶原激活物（ｔＰＡ）而调节纤溶活性外,还参与了很多其它的生理病理过程,例如组织重建、胚胎发育、感染、免疫系统发育、肿瘤浸润和迁移等。更有研究表明胞内型ＰＡＩ－２在抑制细胞凋亡方面也发挥着重要作用。本文就近年来ＰＡＩ－２抑制细胞凋亡的研究进展作一综述。     

重组PAI－1对u－PA抑制活性的研究

利用大肠杆菌表达的重组纤溶酶原激活物抑制因子－１（ｒＰＡＩ－１）具有许多与天然ＰＡＩ－１相同的性质,ｒＰＡＩ－１对ｕ－ＰＡ抑制活性研究的内容包括：几种化学物质（盐酸胍、尿素、硫氰酸钾、ＳＤＳ、氯化钠等）对ｒＰＡＩ－１的激活作用、盐酸胍激活ｒＰＡＩ－１的浓度与温度效应、显色底物法和ＳＤＳ－ＰＡＧＥ纤维蛋白自显影对ｒＰＡＩ－１活性的测定、活性态ｒＰＡＩ－１向潜状态的转变及其与盐浓度和ｐＨ值的关系。     

2—型纤深酶原激活抑制剂研究进展

２－型纤溶酶原激活抑制剂（ＰＡＩ－２）是尿激酶型纤溶酶原激活剂的高效专一抑制剂。ＰＡＩ－２具有较高的稳定性,可以发生自我聚合。ＰＡＩ－２可与细胞内的细胞型纤溶酶原激活剂、纤连蛋白、谷氨酶胺转移酶等多种分子发生反应。ＰＡＩ－２与尿激酶型纤深酶原激活剂的反应遵循丝氨酸蛋白酶抑制剂的作用机制,其自我聚合的发生可能遵循环－片层机制。ＰＡＩ－２在肿瘤的侵润和扩散、皮肤组织受伤和治疗、炎症以及多种疾病的发生过     

精制溶栓酶对家兔血浆t－PA和PAI的影响

精制溶栓酶对家兔血浆ｔ－ＰＡ和ＰＡＩ的影响雷丹青广西医科大学蛇毒研究所南宁５３００２１纤溶系统是机体阻止血栓形成的屏障,ｔ－ＰＡ（纤溶酶原激活剂）是纤溶系统的关键物质,ｔ－ＰＡ对纤维蛋白原有极高的亲和力,它能选择性的激活血凝块中的纤溶酶原生成纤溶酶,...     

人纤溶酶原激活剂抑制物2型(PAI-2)在大肠杆菌中的表达和分离纯化

用ＰＣＲ方法从ｐＰＡＩＪ．７中扩增人纤溶酶原激活剂抑制物２型（ＰＡＩ－２）ｃＤＮＡ,与ｐＵＣ１８重组,经限制性内切酶片段分析与核苷酸序列分析,获得全长人ＰＡＩ－２ｃＤＮＡ．ＰＡＩ－２ｃＤＮＡ与原核表达载体重组,构建原核表达质粒并转化大肠杆菌．经温度诱导表达,重组ＰＡＩ－２占全菌总蛋白的１４％,以可溶性形式存在,具纤溶抑制活性．工程菌发酵、压榨后,用硫酸铵分级沉淀,沉淀物经分子筛、离子交换和疏水性色谱的分离,每升菌液可获得约３０ｍｇ纯度达９０％的蛋白质,比活性为１１８６６ＡＩＵ／ｍｇ蛋白质,得率为１９．２％．     

重组PAI—1对u—PA抑制活性的研究

利用大肠杆菌表达的重组纤溶酶原激活物抑制因子－１（ｒＰＡＩ－１）具有许多与天然ＰＡＩ－１相同的性质,ｒＰＡＩ－１对ｕ－ＰＡ抑制活性研究的内容包括：几种化学物质（盐酸胍,尿素,硫氰酸钾,ＳＤＳ,氯化钠等）对ｒＰＡＩ－１的激活作用,盐酸胍激活ｒＰＡＩ－１的浓度与温度效应,显色底物法和ＳＤＳ－ＰＡＧＥ纤维蛋白自显影对ｒＰＡＩ－１活性的测定,活性态ｒＰＡＩ－１向潜状态的转变及其与盐浓度和ｐＨ值的关系。     

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.