马兜铃水提液对斑马鱼胚胎的致畸作用和心脏毒性的研究

目的：探索马兜铃水提液对斑马鱼胚胎的致畸作用和心脏毒性.方法：分别用不同浓度的马兜铃水提液和马兜铃酸A（AA）处理斑马鱼胚胎,观察致畸作用和对心脏发育影响.结果：给药组的斑马鱼胚胎出现畸形和死亡;当水提液中AA含量为0.5 μg/mL时,胚胎心率明显减慢;AA含量为5μg/mL时,胚胎在24～48 hpf之间全部死亡;水提液的LC50为1.43 μg/mL.结论：与AA相比,马兜铃水提液对斑马鱼胚胎有着更强的致畸和心脏毒性,且毒性作用具有时间和浓度依赖性.     

马兜铃酸对斑马鱼肾损伤因子（KIM-1）表达的影响

采用分子定量方法检测斑马鱼(Danio rerio)幼鱼组织中KIM-1蛋白含量和基因表达水平,了解马兜铃酸处理后斑马鱼体内肾损伤因子的表达变化情况,并与幼鱼表型变化相比较,探讨KIM-1作为肾功能特异标志物在斑马鱼肾功能损伤评价中的应用价值。结果显示,马兜铃酸处理30 h后,幼鱼出现水肿,水肿发生率呈剂量依赖性特点。0.5~5.0μmol/L马兜铃酸处理组幼鱼水肿发生率与对照组差异不明显,但幼鱼KIM-1因子的蛋白含量及Kim-1基因表达水平比正常对照组显著升高,在马兜铃酸浓度为2μmol/L时达到最高。表明在肾功能损伤检测中,KIM-1是一种比表型更早发生变化的指标。     

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。     

PKA对斑马鱼前肾发育的影响及其机制研究

作为一个胞内蛋白激酶,PKA在中枢神经系统、眼睛和肢体等形态发生中担任了重要角色,并参与多种细胞行为,但其在肾脏发育中的作用却不十分清楚.以斑马鱼为模式动物,采用原位杂交和冰冻切片技术检测PKA在斑马鱼中的表达情况;通过显微注射反义吗啉环寡核苷酸的方式,抑制内源性PKA的表达;通过免疫荧光技术,检测斑马鱼前肾的微观结构.结果显示:编码斑马鱼PKA催化亚基的prkaa1和编码调节亚基的prkab1b 均为母源基因,并且在肾管上皮细胞中有特异性表达;分别抑制内源性prkaa1或prkab1b 的表达,胚胎于第3天呈现高比例的心脏水肿(分别为54.4%和77.3%)和体轴弯曲(分别为48.5%和72.6%)以及极低比例的多囊肾表型(<5%);进一步检测发现,抑制PKA会导致肾管上皮细胞迁移缺陷,尤其是阻碍肾管多纤毛细胞迁移,继而引起肾管前中部不同程度肿大,并最终导致胚胎死亡.该研究表明,PKA可能通过调控斑马鱼肾管上皮细胞迁移从而在肾脏发育中发挥作用.     

Nephrin 信号转导机制研究进展

Nephrin作为肾小球足细胞膜上的跨膜蛋白,是足细胞裂隙膜重要的结构分子。近来发现,nephrin分子细胞内段的酪氨酸残基在被酪氨酸激酶fyn（属Src激酶家族成员）磷酸化后,能激活下游信号分子,形成足细胞内特有的信号转导通路,如nephrin—podocin—MAPK—AP-1、nephrin—CD2AP-P13K-Akt／PKB、nephrin-Nck—Rac／CDC42等。这些信号通路参与了足细胞胚胎发生、细胞生存与细胞骨架重组等许多重要生理病理过程的调节。同样,nephrin蛋白及mRNA的表达也受许多因素的调节。研究nephrin及其信号转导机制对了解并防治肾小球硬化有重要意义。     

Nephrin与糖尿病肾病

Nephrin是特异性表达于肾小球足细胞的一种跨膜蛋白,定位于肾小球足突细胞裂隙隔膜,在维持肾小球滤过屏障完整性及其正常功能过程中起关键作用。糖尿病肾病(DN)患者肾小球nephrin及其受体表达下降。破坏了肾小球足突细胞裂隙隔膜结构与其屏障功能的完整性,蛋白质从肾小球滤出增多,引起蛋白尿。Nephrin在DN的发病机制中起关键作用,深入研究nephrin可进一步了解DN的发病机制,对其诊断和治疗有重要的指导意义。     

四种新型农药对斑马鱼胚胎发育的毒性效应

为了研究4种农药(腈苯唑、吡唑醚菌酯、恶霜灵、戊菌隆)单独及联合作用对斑马鱼胚胎发育的影响,设计7个实验组(空白组、溶剂组、4种农药单独暴露组及联合暴露组)对斑马鱼胚胎暴露72 h,结果显示,浓度50 ng/L的4种农药单独暴露导致心包囊和卵黄囊水肿比率、脊柱弯曲率均显著高于对照组;腈苯唑、恶霜灵及联合暴露导致斑马鱼仔鱼心率显著下降,出现显著的心律不齐;斑马鱼胚胎的Na~+/K~+-ATP酶和Ca~(2+)-ATP酶活性被显著诱导,而联合暴露表现出显著的抑制作用。结果说明,环境浓度的农药暴露对鱼类胚胎发育具有明显的毒性。     

芪地固肾方对膜性肾病大鼠肾组织足细胞裂孔隔膜蛋白Nephrin和Podocin表达的影响

摘要 目的：探讨芪地固肾方治疗膜性肾病（MN）大鼠的效果及其可能的机制。方法：将40只SD雄性大鼠随机分为模型组（等剂量生理盐水尾静脉注射）、雷公藤多甙片组（10 mg/kg雷公藤多甙片）、芪地固肾方低剂量组（15.425 g/kg芪地固肾方）、芪地固肾方高剂量组（61.7 g/kg芪地固肾方）四组,另取10只未造模大鼠作为空白组（等剂量生理盐水尾静脉注射）,连续干预28天后,检测24小时尿蛋白定量（U-TP）、血清总蛋白（TP）、白蛋白（ALB）、谷丙转氨酶（ALT）、谷草转氨酶（AST）、血肌酐（Scr）、尿素氮（BUN）的变化;HE染色、透射电镜观察大鼠肾组织病理学改变;RT-PCR检测肾组织中nephrin蛋白、podocin mRNA的表达。结果：与空白组比较,模型组24 hU-TP、足细胞nephrin和podocin mRNA显著升高,血清TP和ALB显著降低（P<0.01）;与模型组比较,各给药组24 hU-TP降低,血清TP和ALB显著升高（P<0.05）;肾组织免疫复合物沉积减少,肾小球基底膜增厚减轻;足细胞nephrin和podocin mRNA表达升高（P<0.05）。结论：芪地固肾方能够降低MN模型大鼠的尿蛋白水平,减轻肾脏病理损伤,上调肾组织中足细胞裂孔隔膜蛋白nephrin和podocin mRNA的表达,延缓膜性肾病的进展。     

三氯乙烯对斑马鱼胚胎心脏发育的毒性作用及机制*

目的:研究三氯乙烯(TCE)对斑马鱼胚胎心脏发育的毒性作用及其机制,为寻找干预靶点提供实验依据。方法:斑马鱼胚胎来自于国家斑马鱼资源中心,分为DMSO组(对照组)、DMSO+CHIR组、DMSO+XAV组、TCE处理组、TCE+CHIR组和TCE+XAV组(TCE设置为1、10、100 ppb三个不同的浓度;DMSO:二甲基亚砜;CHIR:CHIR-99021,Wnt信号通路激活剂;XAV:XAV-939,Wnt信号通路抑制剂),每组60条。斑马鱼胚胎饲养于系统养殖水中,恒温28℃,每隔24 h更换养殖水,并分别加入相应药物。连续培养72 h,收集斑马鱼胚胎的心脏组织,提取RNA进行转录组芯片分析,并以荧光定量PCR验证Wnt信号通路相关基因的表达。结果:与对照组相比,三氯乙烯暴露导致斑马鱼心脏畸形显著增加,以心房心室比例异常、环化不全以及心包水肿等为主要表型。芯片分析结果显示,TCE处理组Wnt信号通路相关基因(Axin2、Sox9b、Nkx2.5)表达受到显著影响。qPCR结果进一步验证,TCE处理组与DMSO对照组相比,Wnt通路靶基因Axin2、Sox9b及Nkx2.5的mRNA水平显著下调(P＜0.05),提示Wnt信号通路被抑制。Wnt激活剂CHIR降低TCE导致的斑马鱼胚胎心脏发育异常,而添加Wnt通路抑制剂XAV后,斑马鱼胚胎心脏畸形率显著增加(P＜0.05)。结论:三氯乙烯暴露导致斑马鱼胚胎心脏畸形,Wnt信号通路参与三氯乙烯的心脏发育毒性。     

外源性视黄酸对斑马鱼心血管系统发育的影响

目的观察不同浓度外源性视黄酸对斑马鱼早期胚胎和心血管系统发育的影响,为进一步研究视黄酸影响斑马鱼心脏前后轴(A-P轴)发育的分子机制提供形态学依据。方法选择斑马鱼胚胎孵育的3,6,9·5,12h四个时间点,用不同浓度视黄酸(1×10-6,1×10-7,4×10-8,1×10-8mol/L)处理斑马鱼胚胎,在解剖显微镜下实时观察斑马鱼胚胎心脏发育的全过程和视黄酸对斑马鱼心脏发育的影响。并采用胚胎整体原位杂交技术观察flk-1mRNA在斑马鱼胚胎的表达。结果1×10-6mol/L视黄酸可导致斑马鱼胚胎表现出多系统的严重畸形,胚胎很快死亡。在胚胎孵育的9·5、12h给与10-7~10-8mol/L浓度的视黄酸,胚胎只表现出心血管系统的畸形,其他系统无明显异常。胚胎整体原位杂交显示视黄酸对flk-1mRNA在斑马鱼胚胎血管的表达没有影响。结论视黄酸影响斑马鱼胚胎心脏发育有剂量依赖性和严格的时间窗,视黄酸影响心脏前后轴发育的关键时间是原肠胚晚期。视黄酸处理组胚胎的循环缺陷主要为心脏发育异常所致。10-7~10-8mol/L浓度视黄酸在9·5、12h处理斑马鱼胚胎可以作为研究心脏发育调控机制的动物模型。     

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.