急性眼高压后大鼠视网膜GLT-1的表达变化

目的:检测急性眼高压后大鼠视网膜GLT-1的表达变化。方法:成年大鼠左眼眼压升高至闪光视网膜电图b波消失的临界眼压且维持缺血60min。实验动物分别存活1、3、7或14d后通过免疫组织化学检测大鼠视网膜GLT-1的表达变化,尼氏染色检测节细胞的变化。结果:急性眼高压后视网膜随着再灌时间的延长,内层视网膜厚度逐渐变薄,节细胞层细胞数目进行性下降。GLT-1阳性产物主要表达于OPL和IPL。急性HIOP后再灌1天时,与正常组相比,此时GLT-1表达增加(P＜0．05)。再灌3天时, GLT-1表达量继续增加。第7天时GLT-1表达开始下调,至14天时,GLT-1表达明显低于3天组,但仍高于正常组(P＜0．05)。结论:急性眼高压可导致视网膜GLT-1表达增加,其机制可能与其自身的保护反应有关。     

早期糖尿病大鼠晶状体和视网膜水通道蛋白4表达的研究

目的观察早期糖尿病大鼠晶状体、视网膜水通道蛋白4(aquaporin 4,AQP-4)表达的变化,探讨糖尿病大鼠眼组织水代谢改变的机制。方法 SD大鼠分为正常对照组和糖尿病组。制作糖尿病大鼠模型,于第4、8周取材,用免疫组化法和计算机图像分析系统半定量分析各组大鼠晶状体、视网膜AQP-4表达的变化。结果正常及糖尿病大鼠AQP-4在晶状体上皮均无表达。AQP-4在视网膜上有表达,正常大鼠主要表达于视网膜视杆视锥层、节细胞层和神经纤维层,糖尿病大鼠从内界膜延伸至视细胞层整个视网膜厚度均可见AQP-4阳性表达,特别是在神经节细胞层毛细血管内皮和神经纤维层阳性表达更明显。糖尿病大鼠视网膜组织AQP-4阳性表达标随周龄的延长而增强。结论糖尿病大鼠视网膜AQP-4的表达较正常组增强,提示水通道蛋白的表达增加是糖尿病早期发生视网膜水肿的机制之一。     

大鼠视网膜缺血后一氧化氮合酶阳性神经元的变化

本文用前房加压灌注视网膜缺血模型、β－ＮＡＤＰＨ脱氢酶组化方法研究了ＳＤ大鼠视网膜内含一氧化氮合酶（ＮＯＳ）神经元的分布及其变化。实验动物依缺血时间分四组,分别为缺血１０ｍｉｎ、１５ｍｉｎ、３０ｍｉｎ及６０ｍｉｎ组。将ＮＯＳ阳性细胞进行计数统计,做自身配对ｔ检验及方差分析。实验结果表明正常及缺血视网膜ＮＯＳ阳性神经元。大多数位于内核层,少数位于节细胞层;ＮＯＳ阳性细胞在视网膜中央区密度高于周边区,而各象限的平均密度分布无明显差别。缺血１５ｍｉｎ后内核层的ＮＯＳ阳性细胞开始减少,随缺血时间的延长细胞减少更为明显。各组均以视网膜中央区变化较为显著,提示视网膜缺血１５ｍｉｎ后即可出现神经生物学变化,视网膜中央区对缺血比周围区更为敏感。     

大鼠视网膜中HAP1的免疫组织化学定位及不同光照条件对HAP1表达的影响

目的探讨亨廷顿蛋白相关蛋白1(huntingtin associated protein 1, HAP1)是否存在于视网膜内及是否与视觉有关.方法对正常大鼠眼球壁用ABC法进行免疫组织化学染色,观察HAP1在视网膜中的定位;用半定量免疫印迹方法(Western blotting)检测不同光照条件对大鼠视网膜中HAP1表达的影响.结果 HAP1较广泛地分布在大鼠视网膜各层,但以内核层及外核层中免疫反应较强,阳性反应产物主要定位在节细胞层和内核层/外核层中部分细胞胞体内;其余各层中,HAP1免疫反应较弱,阳性产物呈弥散分布,未见明显的阳性胞体.在连续处于黑暗环境中72小时大鼠视网膜中,HAP1表达较常规光照动物明显减少,而连续光照72h大鼠视网膜内HAP1表达无明显变化.结论 HAP1在视网膜中的存在及不同光照条件对视网膜HAP1表达的影响表明,HAP1可能与视觉活动有关.     

川芎嗪联合氨胍治疗对糖尿病大鼠视网膜血管内皮生长因子表达的影响

目的 观察川芎嗪联合氨胍治疗对糖尿病大鼠视网膜血管内皮生长因子（VEGF）表达的影响。探讨川芎嗪联合氨胍治疗糖尿病视网膜病变（DR）的机制。方法 应用链尿佐菌素（STZ）制作糖尿病大鼠模型。分为正常对照组,糖尿病未治疗组,川芎嗪治疗组,氨胍治疗组和川芎嗪联合氨胍治疗组,分别于第4周,第12周和第20周应用免疫组化方法观察各组大鼠视网膜组织VEGF表达的变化。结果 正常大鼠视网膜组织VEF表达仅见于内核层,糖尿病大鼠视网膜组织VEGF阳性表达随周龄的延长而增强,且在毛细血管内和节细胞层可见VEGF表达,治疗12周和20周后,川芎嗪治疗组和氨胍治疗组大鼠视网膜组织VEGF阳性表达比未治疗组明显减弱,但仍高于正常对照组,而川芎嗪联合氨胍治疗组视网膜组织VEGF表达接近正常。结论 川芎嗪联合氨胍治疗可抑制糖尿病大鼠视网膜VEGF的过度表达。是川芎嗪联合氨胍治疗糖尿病视网膜病变（DR）的机制之一。     

脑红蛋白在家兔视网膜中的分布

目的探讨脑红蛋白(NGB)在家兔视网膜的分布特征。方法选择健康成年家兔5只,利用免疫组织化学染色SP法,观察NGB在家兔视网膜中的分布情况。结果 NGB在家兔视网膜的视神经纤维层、节细胞层、内网状层、外网状层、光感受器内节段和色素上皮层中有强阳性表达,在视网膜的内核层有弱阳性表达,在视网膜的外核层和光感受器外节段中未见有阳性表达,内界膜、外界膜和视神经中亦发现有NGB阳性表达。家兔视网膜NGB阳性表达的细胞类型主要有节细胞、双极细胞和光感受器细胞,其中节细胞的阳性表达定位于细胞质,胞核中未见表达。结论除外核层和光感受器外节段外,NGB在家兔视网膜其它各层中均有表达,提示NGB在维持视网膜氧代谢平衡中发挥着重要作用。     

玻璃体腔联合注射赖氨酸－纤溶酶原和瑞替普酶诱导兔眼玻璃体后脱离的有效性

目的:探讨兔眼玻璃体腔联合注射赖氨酸-纤溶酶原和瑞替普酶诱导玻璃体后脱离(PVD)的有效性。方法:选取30只健康的新西兰白兔,以白兔右眼作为实验眼,左眼作为对照眼。随机分为A、B、C三组(每组10只),三组实验眼分别联合应用1万U瑞替普酶+125μg赖氨酸—纤溶酶原、2万U瑞替普酶+125μg赖氨酸—纤溶酶原、3万U瑞替普酶+125μg赖氨酸—纤溶酶原进行玻璃体腔内注射,对照眼均注射平衡盐溶液。应用视网膜电图、扫描电镜及光镜观察、比较各组诱导PVD的效果。结果:三组实验眼均形成不同程度PVD。A组实验眼注药前与注药后24 h、注药后2周的最大混合反应a波振幅、b波振幅比较均无明显差异(P0.05);B组实验眼注药后24 h的a波振幅、b波振幅均有轻度下降,2周后均恢复正常,注药前后的a波振幅、b波振幅比较均无明显差异(P0.05)。C组实验眼注药后24 h的a波振幅、b波振幅均明显低于注药前和对照眼,注药后2周的b波振幅均明显低于注药前和对照眼(P0.05)。光学组织切片观察显示:A组实验眼及所有对照眼、B组实验眼、C组实验眼的视网膜组织细胞形态正常,结构清晰,但B组神经节内核层、细胞层细胞略有减少,C组神经节内核层及细胞层细胞明显减少。结论:玻璃体腔内联合注射赖氨酸-纤溶酶原和瑞替普酶能有效诱导PVD,1万U瑞替普酶+125μg赖氨酸-纤溶酶原可诱导实现完全性PVD,不会对视功能、视网膜结构造成损害。     

维拉帕米对缺血后大鼠视网膜NOS阳性神经元的影响

实验用 β- NADPH脱氢酶组织化学染色研究维拉帕米对缺血后大鼠视网膜 NOS阳性神经元的影响。结扎双侧颈总动脉使视网膜缺血 ,3小时后松结复流。分别于缺血前 15分钟和再灌流前 1分钟腹腔注射维拉帕米 (5 m g/kg/次 ) ,对照组腹腔注射等量生理盐水。动物存活 3天后取视网膜进行 β- NADPH组化反应。结果表明 :视网膜缺血后 NOS阳性神经元减少 ,并出现 i NOS阳性细胞。在缺血前后应用维拉帕米可使视网膜内 NOS神经元较对照组显著减少 (P<0 .0 1) ,NOS神经元形态良好。说明维拉帕米减少大鼠视网膜缺血后 NOS阳性神经元 ,其相应 NO量减少 ,推测维拉帕米对大鼠缺血后视网膜功能具有保护作用。     

肾上腺髓质素在糖尿病视网膜细胞高表达的研究

探讨肾上腺髓质素(Adrenomedullin,AM)在糖尿病视网膜病变(Diabeticretinopathy,DR)发病中的作用。Sprague-Dawley雄性大鼠尾静脉注射链脲佐菌素造模,以血糖测定和尿糖水平测定进行筛选,正常对照组尾静脉注射等量枸橼酸钠缓冲液。成模后继续饲养4周,取出眼球视网膜组织,连续冰冻切片,用免疫组织化学SABC法染色观察各组大鼠视网膜RPE细胞AM的表达情况。糖尿病大鼠成模前,两组动物的体重、血糖和尿糖检测结果间无显著性差异(P>0.05)。成模后4周,糖尿病组与正常组大鼠体重、血糖和尿糖数值差异有显著性意义(P<0.01)。AM在正常组大鼠视网膜节细胞层及内核层均有表达,正常组大鼠视网膜AM的光密度值为76.3±5.3,单位面积AM阳性细胞数为(4.5±1.1)×103/mm2。糖尿病大鼠视网膜内RPE细胞肾上腺髓质素表达显著增强,糖尿病大鼠视网膜RPE细胞AM的光密度值为105.7±11.9,单位面积AM阳性细胞数为(17.9±2.3)×103/mm2。两组相比,差异具有显著性(P<0.01)。AM在糖尿病大鼠视网膜RPE细胞表达量增加很可能是DR发生、发展的重要因素。     

大鼠骨髓间充质干细胞在正常及激光损伤视网膜下移植分化的差异

观察骨髓间充质干细胞(mesenchymal stem cells, MSCs)在体外不诱导的条件下视网膜移植于正常或大鼠Nd︰YAG激光损伤视网膜后的定位以及蛋白表达情况. 体外培养大鼠MSCs, 用荧光染料DAPI标记MSCs, 视网膜下移植后分别于10, 20, 35和50天处死动物, 做DAPI荧光观察, 并在阳性的连续切片上做神经元核(neuronal nuclei, NeuN)、神经元特异性烯醇化酶(neuron specific enolase, NSE)、胶质纤维酸性蛋白(glial fibrillary acidic protein, GFAP)和角蛋白(pancytokeratin, CK)免疫组化染色及HE染色. 对损伤大鼠分别于损伤前及损伤后即刻、1~7周检测损伤移植组、损伤组和损伤注射生理盐水组的视网膜电流图(ERG)b波分析. 培养的MSCs集落生长迅速, 均一性好, DAPI染色观察表明, 10天时移植细胞多集中于移植部位周围, 正常移植组可见分层, 而损伤移植组分布散乱; 20天时两组均可见阳性细胞分布范围扩大, 分布于视网膜各层; 35天正常移植组阳性细胞范围与20天基本相同, 而损伤组则进一步扩大, 且细胞开始向损伤部位迁移; 50天正常移植组荧光范围比35天小, 未发现细胞增生, 损伤组损伤范围与35天相比扩大不明显, 但许多部位有增生. 免疫组织化学染色发现阳性区域的细胞在NeuN, NSE, GFAP和CK 的表达有不均一性. HE染色表明移植组损伤的恢复好于损伤对照组, ERG b波检测表明5周后损伤移植组的b波水平高于对照组. MSCs可在正常及激光损伤的大鼠视网膜下与原视网膜结构相融合, 检测到的阳性细胞分布于视网膜色素上皮层、视细胞层、双极细胞层及节细胞层, 正常移植组随时间延长荧光范围缩小, 损伤移植组荧光分布范围随时间延长分布较广, 但细胞的排列和蛋白表达有紊乱. MSCs的移植对激光损伤斑及ERG b波的恢复有促进作用.     

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.