小鼠排卵前后卵巢纤蛋白溶酶原激活因子活性的变化

给幼龄小鼠注射PMSG刺激滤泡生长,随后注射hCG以诱发排卵。在激素处理的不同时间取出卵巢,制备卵巢匀浆液或从卵巢中分离颗粒细胞和卵丘-卵母细胞复合体,并做离体培养。样品中组织型(tPA)和尿激酶型(uPA)纤蛋白溶酶原激活因子经SDS-凝胶电泳分离,用纤蛋白铺盖技术测定。实验结果表明,注射hCG 8h后15％的受试动物排卵,而卵巢匀浆液和颗粒细胞中tPA和uPA活性分别也在hCG注射后4和8h达到高峰。排卵后酶活性下降。卵丘-卵母细胞复合体主要含tPA,注射hCG 12—24h达到高峰。上述资料证明,tPA和uPA都参入小鼠排卵过程。因为排出的卵子中仍含有大量tPA,卵细胞的tPA除参与排卵外,可能对排卵后的一些生理过程也起重要作用。     

大鼠卵巢细胞分泌纤溶酶原激活因子抑制因子(PAI-1)的激素调节

哺乳动物卵巢合成两类纤溶酶原激活因子(PA),即组织型PA(tPA)和尿激酶型PA(uPA)。大鼠卵巢除主要合成tPA外,还分泌一种纤溶酶激活因子的抑制因子(PAI-1)。在促性腺激素作用下,卵巢tPA和PAI-1两种基因的协调表达是导致滤泡破裂的原因。本实验进一步证实,卵巢中的PAI-1主要由膜-间质细胞分泌,可能作为一种屏障限制颗粒细胞tPA分泌到滤泡外间质。当排卵来临时,两种细胞所分泌的tPA和PAI-1相互作用后仍发现有大量tPA活性。这可能是引起排卵的主要原因。因为成熟的卵丘细胞除分泌高量tPA外,还分泌大量PAI-1,在人工授精中两者有可能作为鉴定卵子优劣的可靠指标。     

卵巢纤蛋白溶酶原激活因子及其抑制因子的研究

本文综述了近年来作者在研究卵巢纤蛋白溶酶原激活因子(PA)及其抑制因子(PAI)的某些成果。PA是一种高效能蛋白水解酶激活因子,它激活纤蛋白溶酶原成为纤蛋白溶酶,此酶在纤蛋白水解过程中起重要作用。已有证据表明,PA与排卵有关。我们进一步研究发现:(1)在大鼠卵巢体细胞中存在两种PA,即组织型PA(tPA)和尿激酶型PA(uPA);而在卵细胞中只发现tPA;(2)大鼠卵巢tPA明显受促性腺激素和其他激素调节,并在排卵前达到高峰,而uPA没有明显变化;(3)在卵巢体细胞中还发现一种PA的抑制因子(PAI),它与PA结合形成复合体,能部分或完全消除PA活性;(4)只有tPA与大鼠排卵有关;PA和PAI间的相互作用和随激素的波动而引起的动态变化可能对维持卵巢正常生理功能和排卵起重要作用。     

纤溶酶原激活因子与猕猴精子运动力的关系及其在附睾和附性腺中的表达调节

用11酸睾酮诱导猕猴少精子症和弱精子症及单侧隐睾手术诱导单侧少精子症和弱精子症模型,观察对附睾头、附睾体、附睾尾、前列腺和精囊组织型PA（tPA）、尿激酶型PA（uPA）及抑制因子-1（PAI-1）mRNA表达的影响。原位杂交的结果表明11酸睾酮诱导少精子症和弱精子症,tPA mRNA的表达在附睾头、精囊及前列腺减少,而在附睾体升高,附睾尾表达基本无变化;uPA mRNA的表达在附睾头、附睾体、前列腺减少,而在精囊升高,附睾尾表达基本无变化;PAI-1 mRNA的表达在附睾头、附睾体、精囊下降,而在前列腺升高,附睾尾表达无显著变化。单侧隐睾手术不影响tPA、uPA和PAI-1 mRNA的表达。这些结果提示附睾头和附睾体分泌的uPA可能与精子前向运动能力的获得相关。tPA、uPA和PAI-1 mRNA在猕猴附睾头部和体部、前列腺和精囊中的表达可能受睾酮的调节,但不受睾丸分泌因子及温度的影响,且在不同部位睾酮的调节具不同的特征,而附睾尾tPA、uPA和PAI-1的表达则可能是组成性表达。     

猕猴精浆纤溶酶原激活因子的来源及在精子获能中的作用

我们的前期工作表明,不育症人精液中纤溶酶原激活因子（plasminogen activator;PA）活性明显升高;给成年办和猕猴注射长效睾酮诱发无精过程中,精液PA含量也伴随上升,为进一步查明PA的来源和对精子的作用,原位杂交检测组织型PA（tPA）,尿激酶型PA（uPA）及PA抑制因子－1（PAI-1)泊mRNAs在成年健康猕附睾、前列腺和精囊中的表达。体外培养猕猴精子,培液中加入uPA、tPA及其底物纤溶酶原（plasminogen）,测试PA对精子活力、顶体反应及激活卵子的影响。结果表明,猕猴附睾、前列腺和精囊均表达tPA、uPA和PAI-1 mRNAs。加入uPA能维持精子的活力,使精子产生超激活运动,诱导顶体反应的发生,并使精子获得激活卵子的能力,这说明猕猴精浆PA除来源于睾丸外,可能主要来源于附睾及附性腺;在体外,uPA,而不是tPA,可能诱导精子获能。     

三七皂苷Rg1对tPA和PAI-1活性的调节作用

探讨三七皂苷Rg1对组织型纤溶酶原激活物(tPA)和纤溶酶原激活物抑制物(PAI-1)活性的调节作用。运用发色底物方法测定三七皂苷Rg1在体外和静脉注射对家兔血浆纤溶酶原激活物(tPA)和血浆或血小板释放的纤溶酶原激活物抑制物(PAI-1)水平的影响。结果表明,三七皂苷Rg1在体外呈浓度依赖性明显抑制血浆PAI-1活性,同时提高血浆tPA活性;30和60 mg/kg的三七皂苷Rg1静脉注射显著抑制血浆PAI-1活性,提高血浆tPA活性,同时降低凝血酶激活的血小板所释放的PAI-1水平。本实验提示三七皂苷Rg1能抑制PAI-1活性,同时升高tPA活性可能是其抗血栓作用的分子机制之一。     

纤溶系统对膜性肾病大鼠足细胞损伤的影响

目的探讨早期预防纤溶紊乱对防止MN进展有重要意义。方法按改良Border法制作MN大鼠模型,正式免疫第1、2、3、4周末检测全血uPA、tPA及PAI-1的表达水平;取大鼠肾组织进行光镜、电镜观察肾组织病理学改变;采用免疫组化方法检测肾足细胞nephrin、WTl蛋白表达含量,并进行相关性分析。结果与正常组及干预组大鼠相比,模型组大鼠的全血uPA、tPA水平明显减少,而PAI-1水平明显增加,差异具有统计学意义(P0.05);电镜显示肾小球足细胞广泛足突融合至消失;GBM基质出现"钉样突起",肾间质纤维化程度较重。肾小球足细胞分布区WT-1和nephrin蛋白表达下调,其中nephrin蛋白表达量变化有统计学意义(P0.01)。相关性分析显示,大鼠全血tPA和uPA水平与肾组织nephrin蛋白的表达变化呈正相关,全血PAI-1水平与肾组织nephrin蛋白的表达变化呈现负相关。结论在MN发展中,纤溶系统对足细胞损伤凋亡具有重要意义,早期评估预测MN足细胞损伤情况或可为防治早期MN步入终末期肾脏病找到又一治疗靶点,亦可为临床研究治疗MN的药物提供新的思路。     

血管内皮细胞介导的纤溶作用

血管内皮细胞可合成和释放tPA、uPA和PAI-1,也提供纤溶成份之间相互作用的活性表面,在纤溶的启动和调节中起重要作用。内皮细胞介导的纤溶作用受到神经激素,生长因子、血浆成份、血细胞、血管壁基质和许多外源性物质的调控。     

uPA、PAI-1 的表达和MVD 计数与浸润性乳腺癌侵袭性的关系

目的:探讨尿激酶型纤溶酶原激活剂(uPA)、纤溶酶原激活物抑制剂(PAI-1)的表达和血管形成与浸润性乳腺癌侵袭性的关系。方法:应用免疫组化SP法检测80例浸润性乳腺癌、20例良性乳腺肿瘤组织中uPA、PAI-1的表达情况并进行微血管计数。结果:uPA和PAI-1在浸润性乳腺癌组的阳性表达显著高于良性肿瘤组,且其高表达率与乳腺癌的临床病理参数密切相关(P<0.05);微血管计数在乳腺癌组和良性肿瘤组分别为30.87±7.64、20.28±8.72,两组比较有显著性差异(P<0.01)。uPA与PAI-1在浸润性乳腺癌中的表达呈正相关(P<0.05)。结论:uPA、PAI-1的高表达与浸润性乳腺癌的浸润、转移相关,uPA、PAI-1的高表达和MVD计数可作为评价浸润性乳腺癌侵袭性、评估预后和确定治疗方案的生物学指标。     

福斯科林对大鼠排卵的作用及卵巢纤溶酶原激活因子活性影响

利用未成年大鼠研究了福斯科林对大鼠排卵作用及卵巢中纤溶酶原激活因于活性与排卵的关系。实验结果表明23日龄未成年大鼠,预先注射孕马血清,48小时后注射5,10,20,40及80微克五种不同剂量福斯科林,均不能引起动物排卵。当给以20微克及80微克福斯科林,同时增注前列腺素E_240微克,能引起动物排卵,平均排卵数为8.1±3.8个和9.8±6.5个。注射不同剂量福斯科林后,卵巢中纤溶酶原激活因子活性随注射剂量增加而增加,但并不呈线性关系。虽然注射福斯科林和前列腺素E_2能引起动物排卵,但卵巢中纤溶酶原激活因子活性与不排卵及超数排卵动物比较并无显著性差异。实验结果提示,福斯科林不直接引起大鼠排卵,只在与前列腺素E_2合并用药时才引起排卵。卵巢内纤溶酶原激活因子活性随注射福斯科林增加而增加,但不对卵泡破裂起直接作用。     

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.