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1.
本文用酶标胎球蛋白作为探针,在光镜水平对花背蟾蜍角膜早期发育中胎球蛋白结合位点(FBS)进行组化定位,结果表明FBS主要分布在角膜上皮层,胚胎发育至20期,FBS开始出现;在22期和23期,基底细胞中FBS减少,在基膜附近大量密集;24期FBS在基底细胞中再度增加而均一分布在上皮层,表层细胞游离面在25期在出现无FBS的区带,纤毛细胞中始终无FBS分布,而只在25期时其游离面出现FBS,认为FBS  相似文献   

2.
本文以花背蟾蜍的胚胎(19~25期)为材料,采用放射自显影技术,以~3H—氨基葡糖标记氨基多糖,并用链霉菌透明质酸酶和睾丸透明质酸酶处理作对照,在光镜水平上研究了透明质酸在角膜早期形态发生中合成变化。结果表明:透时质酸的产生及消除与角膜的形成及分化有相应的关系,在内角膜基质原基开始形成的第20期,即间充质细胞向预定角膜上皮与晶状体之间迁移之际,透明质酸的合成量达到最高水平,此后透明质酸的合成量逐渐减少到最低水平,这相应于角膜上皮开始变薄、透明及分化。本文就透明质酸在角膜早期形态发生中的作用机制进行了初步讨论。  相似文献   

3.
花背蟾蜍角膜的发育和诱导   总被引:2,自引:0,他引:2  
以花背蟾蜍的胚胎和变态期蝌蚪为材料,采用光镜、电镜、免疫荧光组织化学、放射自显曩、电镜细胞化学、皮肤片移植及类坏死处理等技术,研究:(1)在胚胎发育及变态期间角膜的发育过程;(2)细胞外基质的合成变化及其对角膜发育和诱导的作用;(3)角膜诱导期间的超微结构变化及类坏死对角膜诱导的影响;(4)在角膜下沉发育和诱导过程中的组织化学和视网膜感光细胞特异视蛋白的出现及二者间的可能关系。还提出角膜诱导的可能  相似文献   

4.
Majo F  Rochat A  Nicolas M  Jaoudé GA  Barrandon Y 《Nature》2008,456(7219):250-254
The integrity of the cornea, the most anterior part of the eye, is indispensable for vision. Forty-five million individuals worldwide are bilaterally blind and another 135 million have severely impaired vision in both eyes because of loss of corneal transparency; treatments range from local medications to corneal transplants, and more recently to stem cell therapy. The corneal epithelium is a squamous epithelium that is constantly renewing, with a vertical turnover of 7 to 14 days in many mammals. Identification of slow cycling cells (label-retaining cells) in the limbus of the mouse has led to the notion that the limbus is the niche for the stem cells responsible for the long-term renewal of the cornea; hence, the corneal epithelium is supposedly renewed by cells generated at and migrating from the limbus, in marked opposition to other squamous epithelia in which each resident stem cell has in charge a limited area of epithelium. Here we show that the corneal epithelium of the mouse can be serially transplanted, is self-maintained and contains oligopotent stem cells with the capacity to generate goblet cells if provided with a conjunctival environment. Furthermore, the entire ocular surface of the pig, including the cornea, contains oligopotent stem cells (holoclones) with the capacity to generate individual colonies of corneal and conjunctival cells. Therefore, the limbus is not the only niche for corneal stem cells and corneal renewal is not different from other squamous epithelia. We propose a model that unifies our observations with the literature and explains why the limbal region is enriched in stem cells.  相似文献   

5.
本文报告用角膜内皮显微镜观察兔穿透性角膜移植术前、术后和角膜移植排斥反应时的角膜内皮改变结果。发现在角膜移植术前,正常角膜的中央区和周边区的内皮细胞密度、细胞面积基本相同,没有显著差异。在角膜移植术后,术眼的植片和受主角膜的内皮细胞均出现密度减低、细胞面积增大,与术前比较有显著差异。在排斥反应期间,植片内皮细胞出现细胞肿胀、边界不清、甚至模糊不能窥见等异常改变,而受主角膜内皮细胞则表现正常。本文认为兔角膜内皮细胞的形态、密度等与人角膜内皮细胞基本相同。穿透性角膜移植术对角膜内皮有较大损伤,植片内皮细胞在排斥反应中遭受严重损害,提出在角膜移植术时,要注意保护角膜内皮;发现排斥反应时,要及时治疗,防止角膜内皮的过多损伤。  相似文献   

6.
小白鼠眼的形态发生的研究   总被引:2,自引:0,他引:2  
从小白发产胚胎第8d形成视泡开始到发育为成体的眼为止,详细观察和描述了其眼的形态发育变化,实验以视网膜、晶体和角膜的发育为主。结果表明:视网膜的发育从胚胎第8d视泡出现开始,在胚胎第9.5d分化为2层,第11.5d分化为4层,刚出生时分化为6层,成年已分化完全,具完整的10层结构;晶体的形态发生经历了晶体板(第9.5d)、晶体凹(第10d)、晶体囊(第10.5d)、初级晶体纤维(第11.5d)及次  相似文献   

7.
为了评价组织工程人角膜内皮(TE-HCE)维持动物角膜透明的效果,利用来自非转染人角膜内皮(HCE)细胞系的核型正常单克隆细胞株为种子细胞、以去上皮层修饰羊膜为载体支架体外重建的TE-HCE,对新西兰兔进行了穿透性角膜内皮移植试验,利用肉眼观察了移植兔眼的水肿和免疫排斥情况,利用裂隙灯显微镜检测了移植兔角膜的透明情况,并利用荧光显微镜检测了移植兔角膜内皮细胞的CM-DiI标记。对撕除后板层新西兰兔眼进行TE-HCE穿透性角膜内皮移植实验的观察和检测结果显示,移植后的兔眼角膜没有出现明显的水肿和排斥等不良反应,使移植兔角膜维持透明的时间长达100d,且角膜内皮移植区的细胞均为带有CM-DiI标记、来自TE-HCE的种子细胞。由此可见,体外重建TE-HCE移植后能使新西兰兔角膜长期保持透明,有望作为HCE的替代物用于角膜内皮失代偿和角膜内皮盲的临床移植和治疗。  相似文献   

8.
Constitutively expressed Fas ligand (FasL) in several distinct epithelial cell types appears to protect tissues by inducing apoptosis of Fas immune cells during inflammatory reactions. To study the rela-tionship of FasL and inflammation process in cornea,we examined the effects of inflammatory cytokine IL-1β on the FasL production,expression and cytotoxic function in corneal endothelial cells. In this paper,we demonstrate that IL-1β inhibits the FasL production and expression in corneal endothelial cells. The promoter activities of FasL in these cells are reduced by IL-1β in a dose-dependent manner. Finally,we also find that IL-1β block the cytotoxic effects of FasL derived from corneal endothelial cells to the Fas target cells. These data support the view that FasL derived from corneal endothelial cells modulate inflammation within cornea.  相似文献   

9.
位晓娟  Liu  Wanshun  Han  Baoqin  Li  Na 《高技术通讯(英文版)》2008,14(1):98-103
In order to evaluate the cytocompatibility and biocompatibility of a new kind of chitosan blend film as a carrier of corneal endothelial cell, rabbit corneal endothelial cells cultured in vitro were breeded onto the film. After a cell monolayer formed, the scanning electron micrography was performed. After inplanted into anterior chamber, slit lamp observation, thickness metering, specular microscopy and HE staining were performed at random time after operation to evaluate the biocompatibility. Inflammation in anterior, thickness of cornea, cell density, hexagonality and cell size of the surgical cornea were taken as the indexes of biocompatibility. The cultured cells exhibited a confluent monolayer 10 days after incubation, which proved the satisfactory cytocompatibility of this film. Biocompatibility assay results suggested the implantation feasibility of the film as a carrier of corneal endothelial cells.  相似文献   

10.
角膜移植排斥反应现已成为角膜移植手术失败的主要原因,研究角膜移植免疫反应具有重要意义。本文报告了用同一供体皮肤移植引起兔同种穿透性角膜移植排斥反应的动物模型,描述了角膜移植术后和皮肤移植术后的经过,排斥反应的临床表现,组织学标本,包括光镜、扫描电镜和透射电镜标本的制作方法,重点报告了排斥反应实验组的角膜和对照组透明角膜的组织学观察结果。发现对照组的透明角膜,除了在供、受体组织交界处形成疤痕外,植片和受主角膜表现与正常角膜相同。而在发生排斥反应的角膜,则有大量新生血管侵入,植片有大量的浸润细胞,这些细胞主要是淋巴细胞,还有巨噬细胞、浆细胞、多形核白细胞、成纤维细胞等。植片组织遭到不同程度的损害,受主角膜除了有新生血管生长和有少量浸润细胞附着以外,没有受损。本文讨论了有关动物模型、排斥反应的临床特征、病理组织学与免疫机理及功能的联系,新生血管在排斥反应中起的作用等问题。我们认为本组实验动物模型的临床表现和组织学改变均符合典型的特异性免疫反应。这种反应以细胞免疫为主,亦有体液免疫参与。血管在免疫排斥反应的传入、传出弧中均超重要作用。  相似文献   

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