胃蛋白酶C基因在大鼠胃底腺发育过程中上皮细胞内的表达

胃蛋白酶原是胃蛋白酶的前体,是脊椎动物中普遍存在的非特异性蛋白消化酶,胃蛋白酶的生物学特性及分子特性已得到了充分研究,虽然有许多于胃蛋白酶产生细胞的研究报告,但胃蛋白酶原基因在这些细胞的表达却知之甚少,本研究采用地高辛标记的RNA探针,用原位杂交的方法研究了大鼠胃底腺中胃蛋白酶产生细胞的个体发育,研究发现,大鼠胃腺在胚胎18．5天开始出现,但没有形态分化;胃蛋白酶mRNA在出生后3．5天首次被原位杂交法检出。胃蛋白酶产生细胞在出生后8周发育成熟,胃蛋白酶的mRNA表达在主细胞和颈粘液细胞内,其发育可分为4个阶段：（1）胚胎18．5天至出生后0．5天;（2）出生后3．5天至2周;（3）出生后3周至4周,;（4）出生后8周,在胃底腺发育过程中,胃蛋白酶mRNA的表达只局限于某种特定的细胞,这些细胞的分布具有明确的阶段特异性,因此,我们认为胃蛋白酶C可作为胃上皮细胞分化的分子标志。     

N-乙酰氨基葡萄糖残基在发育鼠胃底腺颈粘液细胞中的表达

目的 通过大鼠在不同发育阶段中胃底腺细胞表达α-N-乙酰氨基葡萄糖（GluNAc)残基的情况,来研究大鼠胃底腺颈粘液细胞的发生。方法 利用单克隆抗体HIK1083能特异性识别α-GluNA残基的特点,进行免疫组化研究。结果 HIK1083阳性细胞从第19.5天胚胎鼠的胃底腺中开始辨认出来,一直存在至成鼠,这些细胞最初出现在胃底腺的底部,然后向上方移动,最后位于腺体的颈部。结论 胚胎晚期开始表达α-GluNAc残基的细胞可能是原始的颈粘液细胞,随着鼠胃底腺的发育。这些细胞逐渐向上方移动,最终成为颈粘液细胞。     

正常大鼠胃黏膜中肌球蛋白轻链激酶定性和定位观察

目的观察正常大鼠胃组织中肌球蛋白轻链激酶的表达及分布特点。方法取11只SD正常雄性大鼠,在饥饿状态下,处死后取胃组织。通过免疫组化染色,观察正常大鼠胃组织中MLCK的表达及分布。结果MLCK在黏膜肌层、肌层和黏膜下层血管壁平滑肌均有大量表达;在胃底腺中,MLCK主要表达于壁细胞和主细胞胞浆内。结论MLCK不仅存在于平滑肌细胞内,还分布于胃底腺壁细胞和主细胞内,可能参与胃底腺腺细胞的分泌活动。     

发育心肌和心肌干细胞分化后心肌特异蛋白表达的比较研究

为探讨MCSC移植修复缺血性心肌的可能性,观察了大鼠发育心肌和MCSC分化为心肌细胞的cTnT和Cx-43表达特点。结果表明从胚胎发育至成年,心肌cTnT mRNA表达逐渐上调;用BMP-2诱导1周的MCSC可检测到cTnT mRNA表达,3～4周表达显著升高,诱导2周能观察到cTnT蛋白,3～4周可见cTnT呈现横纹样结构。胚胎第11 d心肌可检测到Cx-43 mRNA表达,生后7 d达高峰,以后逐渐降低,17 d趋于稳定。胚胎期Cx-43蛋白多分布于肌膜下,生后10 d位于细胞连接处。诱导的MCSC中Cx-43 mRNA表达特征与cTnT mRNA相似,2周可观察到Cx-43蛋白,3～4周可见Cx-43位于相邻细胞连接处。本研究结果提示,在BMP-2诱导下MCSC可分化为心肌细胞,表现为成熟心肌细胞的结构特征。MCSC有望成为治疗缺血性心脏病的理想种子细胞。     

人正常腺上皮组织中MUC6基因的表达

应用免疫组织化学和原位杂交方法检测人正常腺上皮中MUC6基因的表达。揭示MUC6基因在正常人腺上皮组织中的分布异质性及其特点,结果显示：MUC6基因编码的核心蛋白及其mRNA主要分布于正常胃粘膜胃腺的基底部,上皮细胞无MUC6基因表达。呈细颗粒状,位于细胞核周,胃底,胃窦的表达无区别;十二指肠绒毛上皮内的表达呈弥漫性,均质状,杯状和柱状细胞的表达类似,杯状细胞的粘液滴内未测得MUC6基因产物;空肠,结肠组织中无MUC6基因的表达;胆囊上皮组织内有强阳性MUC6核心蛋白的表达。而宫颈上皮中表达较弱,实验提示;MUC6基因的表达存在异质性及器官特异性。     

人正常腺上皮组织中MUC6基因的表达

应用免疫组织化学和原位杂交方法检测人正常腺上皮中MUC6基因的表达,揭示MUC6基因在正常人腺上皮组织中的分布异质性及其特点.结果显示MUC6基因编码的核心蛋白及其mRNA主要分布于正常胃粘膜胃腺的基底部,上皮细胞无MUC6基因表达,呈细颗粒状,位于细胞核周,胃底、胃窦的表达无区别;十二指肠绒毛上皮内的表达呈弥漫性,均质状,杯状和柱状细胞的表达类似,杯状细胞的粘液滴内未测得MUC6基因产物;空肠、结肠组织中无MUC6基因的表达;胆囊上皮组织内有强阳性MUC6核心蛋白的表达,而宫颈上皮中表达较弱.实验提示MUC6基因的表达存在异质性及器官特异性.     

BTG2基因在大鼠胚胎胰腺不同发育阶段的表达

利用高密度寡核苷酸芯片技术对大鼠胚胎胰腺发育中晚期(E12．5,E18．5,E15．5)调节内外分泌部细胞发育分化及功能代谢的基因的表达趋势进行研究。并用RT-PCR进行验证。用获得的基因信息对:NCBI等公共数据库进行检索,结果发现对细胞的分化、增殖和凋亡起调节作用的BTG2基因在大鼠胚胎胰腺E12．5、E15．5、E18．5天及成年、新生大鼠胰腺中均有表达,且E18．5天的表达量高于其他时期5倍多。推测BTG2可能在大鼠胚胎胰腺内外分泌细胞分化发育的不同阶段起到了促进作用,并参与胚胎胰腺发育晚期的功能代谢完善过程。     

斑马鱼整体原位杂交法研究MMP15a的发育相关表达的初步观察

克隆斑马鱼基质金属蛋白酶15a（MMP15a）基因,并研究其在斑马鱼胚胎早期发育中的时空表达状况。收集不同发育时期的斑马鱼胚胎,制备DIG标记的MMP15a RNA探针,采用全胚胎原位杂交方法研究MMP15a基因在胚胎斑马鱼的表达。结果MMP15a基因在胚胎受精后一个细胞时期就开始表达,从受精后24h起,在眼睛处表达明显,从受精后48h MMP15a在胸鳍和耳囊有特异性表达至到受精后96h。MMP15a在斑马鱼胚胎发育不同时期表达明显,且在胸鳍和耳囊处有持续表达。     

大鼠生后发育过程中胃肠胰生长抑素基因的表达

本实验采用地高辛精标记ｃＲＮＡ探针原位杂交技术和ＡＢＣ免疫组织化学方法,研究了大鼠生后发育过程中胃肠胰组织生长抑素（ＳＳ）基因的表达。结果显示,大鼠生后发育过程中,胃腺ＳＳ杂交阳性细胞及ＳＳ－ＩＲ细胞的密度（细胞数／ｍｍ粘膜肌长）均随天龄增长而增大,至第１５天前后达高峰,随后开始下降,至成年时,与出生时水平接近;十二指肠则在生后初期细胞密度较高,５天以后开始降低,第２０天后降至成年水平。胰腺的ＳＳ杂交阳性细胞及ＳＳ－ＩＲ细胞密度（细胞数／ｍｍ２）变化规律与胃腺相似,随天龄增大,至第１０天前后达高峰,第２０天左右降至成年水平,与出生水平接近。研究结果表明,胃肠胰组织ＳＳ基因表达与胃肠胰的生长发育具有一定的相关性。     

Smad2/3a对斑马鱼神经嵴细胞标记基因crestin表达的影响

目的 探讨Smad2/3a对脊椎动物神经嵴细胞发育的影响。方法 通过在斑马鱼胚胎单细胞时期显微注射smad2/3吗啉环修饰的反义寡核苷酸的方法,特异性敲降smad2/3基因的表达,至胚胎发育至6体节,利用整胚原位杂交检测神经嵴细胞特异性标记基因snail1b,sox10,foxd3和crestin的表达情况;通过casmad2 mRNA和smad3a mRNA显微注射的方法过表达smad2和smad3a,同样利用整胚原位杂交检测神经嵴细胞特异性标记基因crestin的表达情况;通过过表达casmad2及smad3a对下调smad2和smad3a的胚胎进行挽救。结果 smad2/3a被敲低后,crestin的表达量显著降低,而snail1b,sox10和foxd3的表达量无明显变化。smad3b被敲低后,crestin,snail1b,sox10和foxd3的表达量均无明显变化;过表达casmad2和smad3a均可导致crestin的表达量增高;过表达casmad2和smad3a可挽救由于smad2/3a敲降所造成crestin的低表达量。结论 Smad2和Smad3a对神经嵴细胞标记基因crestin的表达具有重要作用。     

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.