硫酸糖胺聚糖(Sulfated Glycosaminoglycans)在花背蟾蜍眼早期形态发生中的合成

本文用放射自显影追踪注射入胚胎的~(35)S-硫酸盐的方法,研究了花背蟾蜍早期形态发生时眼的各部分组织和细胞外基质中的硫酸糖胺聚糖(Sulfated Glycosaminoglycans简称:硫酸GAG)的合成,并分析了其在眼形态发生中的作用。结果表明:1.在眼早期形态发生时,合成的硫酸GAG主要是硫酸软骨素。2.眼各部分组织中在即将分化时硫酸GAG合成率增高,分化开始后逐渐下降到原基形成时的水平。3.在晶状体被诱导时,在视杯和晶状体相互贴近的组织及两者间的细胞外基质中硫酸GAG的合成率明显增加,提示这是晶状体诱导的重要因素。4.角膜上皮形成时即向角膜上皮下层和细胞外基质分泌硫酸GAG;角膜上皮透明时,合成更多的硫酸角质素。     

花背蟾蜍蝌蚪变态期角膜发育的研究

作者用光镜和电镜研究了花背蟾蜍蝌蚪变态期角膜的发育。在后肢发育晚期,内、外角膜在中央部位首先愈台,在完全变态期角膜完全愈合,此时角膜上皮细胞增殖,上皮基质变为Bowman’s膜,内、外角膜之间的成纤维细胞和由它分泌的胶原纤维形成角膜基质,内角膜细胞形成单层的角膜内皮,它与角膜基质间的Descemet’s膜最晚形成。     

花背蟾蜍蝌蚪表皮移植片在角膜诱导中的扫描电镜研究

扫描电镜研究表明,花背蟾蜍蝌蚪在角膜诱导过程中表皮移植片外表面的主要变化是:当移植片细胞中色素消失时,细胞的分泌活动变旺盛,表现在细胞外分泌物增多,这可能与排色素有关。同时移植片细胞表面的微突起和边界嵴日趋细小,移植片透明时它更类似正常角膜。在此期间移植片内表面的主要变化是:细胞外基质不断增加,尤其是胶原纤维的增多和逐渐排列整齐,以及可能由于GAG的合成形成的颗粒状结构的出现和消失,这些都与移植片向角膜上皮分化相关联。由于眼球诱导作用引起的上述变化,都可促进表皮移植片转变为透明的角膜。     

花背蟾蜍角膜早期形态发生中胶原合成的放射自显影研究

本实验以~3H-脯氨酸为标记物,用放射自显影方法研究了花背蟾蜍眼的早期发育中胶原的合成、分布以及对角膜早期形态发生的作用。结果表明,角膜上皮从开始形成即合成胶原,并在角膜上皮基底面聚积。在角膜开始透明时,角膜上皮、内角膜和晶状体的胶原合成速率都明显增加,提示与角膜分化密切相关。     

杭白芷根中分泌道发生方式、分布及其挥发油积累过程研究

为探明杭白芷(Angelica dahurica var.formosana)根中分泌道发生方式、分布及其挥发油转运积累特征,该研究利用光镜及透射电子显微镜技术观察分泌道发生过程及挥发油转运特征,结合组织化学定位确定挥发油的主要积累部位。结果表明:杭白芷根中分泌道由中柱鞘细胞最先发生,次生结构中分泌道主要分布在韧皮部和皮层中;挥发油的合成不仅与分泌细胞中质体及细胞质有关,而且还与周围细胞关系密切;分泌细胞内高尔基体和内质网丰富,可能先通过形成小泡参与转运,再经由细胞壁向腔道内转移;相邻分泌细胞靠近角隅处的细胞壁分泌活动活跃,腔道内积累大量电子致密物质;成熟分泌道中分泌细胞及其腔道内积累大量油滴,因此挥发油主要积累场所为分泌细胞及其腔道。该研究明确了杭白芷根中分泌道的发生方式、分布及其挥发油积累部位,揭示了分泌道发育过程中挥发油的转运积累特征,为进一步阐明分泌组织生长发育与有效成分积累关系提供了理论依据。     

花背蟾蜍(Bufo raddei Strauch)眼形态发生过程中角膜上皮表面结构的扫描电镜观察

扫描电镜观察表明,花背蟾蜍眼形态发生过程中角膜上皮细胞表面形态结构的变化,大致可分三个阶段。1.从神经管期至肌肉感应期预定角膜上皮表面无明显变化;2.在心跳期和鳃血循环期预定角膜上皮表面出现较多的细胞缢束和其下细胞表面的下陷;3.在以后各期,角膜上皮中纤毛细胞的纤毛逐渐退化消失,在右鳃盖封闭期纤毛细胞全部消失。上述变化与视网膜及其中光感受器的发育分化密切相关,纤毛的退化和消失更精确地反映了这种依赖关系,似可作为角??膜上皮分化的一个形态指标。     

兔机械性角膜上皮损伤对结膜杯状细胞及结膜上皮细胞的作用研究

目的探讨机械性角膜上皮损伤对结膜杯状细胞及结膜上皮细胞的作用。方法选取雄性新西兰大白兔12只,建立机械性角膜上皮损伤模型（角膜中央直径8 mm上皮刮除）,建模后使用盐酸林可霉素滴眼,用法为3次/日,1滴/次,观察时间为7 d。在模型建立后第1、4、7天共3个时间点进行结膜印迹细胞学检查、结膜组织透射电镜检查,对结膜上皮细胞及杯状细胞数量及形态进行分析。结果成功建立机械性角膜上皮损伤模型。结膜印迹细胞学检查显示,造模前结膜杯状细胞数量平均值为66.367±2.466（个/每200μm×150μm面积）,Nelson 0级;造模后第1天,结膜杯状细胞数量明显下降,平均值为2.933±0.242（个/每200μm×150μm面积）,Nelson 3级;造模后第4天,结膜杯状细胞数量开始恢复,平均值为17.350±0.991（个/每200μm×150μm面积）,Nelson 2级;造模后第7天,结膜杯状细胞数量已明显恢复,平均值为32.467±2.244（个/每200μm×150μm面积）,Nelson 1级。结膜组织透射电镜检查可见到造模后结膜杯状细胞大量减少,分泌颗粒排空,细胞凋亡,结膜上皮细胞脱落坏死,胞核固缩,胞质中可见溶酶体,上皮下及上皮细胞间炎症细胞浸润;随时间推移,结膜杯状细胞数量及形态逐渐恢复,初期细胞形态欠规则,结膜上皮细胞胞间隙大,连接松散;后期杯状细胞数量明显恢复,形态饱满,分泌功能开始恢复。结膜上皮细胞分化好,细胞连接较为紧密。结论机械性角膜上皮损伤可造成结膜杯状细胞的数量下降及分泌增加,同时可造成结膜上皮细胞凋亡增加,炎症细胞浸润。结膜杯状细胞的数量、功能以及结膜上皮细胞正常结构可在一定时间内自行修复。     

小鼠颌下腺上皮细胞的培养及表皮生长因子的鉴定

体外培养小鼠颌下腺细胞,形态学观察可见有上皮样细胞生长。免疫细胞化学及蛋白质印迹转移分析结果表明,体外培养的颌下腺上皮样细胞可合成并分泌表皮生长因子。     

小鼠角膜发育期间凝集素受体的分布及变化

用辣根过氧化物酶标记的ConA、WGA和RCA Ⅰ为探针,研究了小鼠发育期间角膜内糖残基的分布和变化。Man残基主要分布在角膜基质和内皮;SA残基主要存在于角膜上皮;Gal残基在角膜上皮和基质中都有分布。Man残基在出生前后的小鼠角膜基质中朝内皮方向呈现递增的梯度。SA和Gal残基随角膜发育最后在成体角膜上皮的外表而密集。胎龄13天是小鼠角膜成纤维细胞合成复合糖的起始时间。     

大鼠眼球和泪腺中睫状神经营养因子及其受体的组织定位

目的观察睫状神经营养因子(CNTF)及其受体CNTFRα在大鼠眼球、泪腺上的分布情况.方法取雄性SD大鼠两侧眼球和泪腺,作石蜡切片,用免疫组织化学ABC法染色检测眼球、泪腺中CNTF和CNTFRα的免疫阳性反应.结果 CNTF和CNTFRα的免疫阳性反应产物在眼球和泪腺的组织定位基本相同,包括角膜上皮细胞、固有层神经纤维、角膜细胞、内皮细胞,虹膜上皮细胞,睫状体上皮细胞,晶状体上皮,视网膜色素上皮细胞、苗勒细胞、节细胞层细胞,球结膜上皮细胞,泪腺腺细胞及导管上皮.结论 CNTF及其受体选择性地分布于眼球和泪腺的一些细胞中,且多数细胞与房水和泪液的产生和接触有关.     

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.