自体角膜缘上皮移植和羊膜移植治疗翼状胬肉的疗效观察

目的 :比较自体角膜缘上皮移植和羊膜移植治疗翼状胬肉的疗效。方法 :随机将翼状胬肉 5 8例、6 2眼分为A、B两组 ,按Prabhasawat等提出的疗效标准进行疗效分级评价。A组 30例、32眼行自体角膜缘上皮移植术 ;B组 2 8例、30眼行羊膜移植术。术后随访 1年 ,比较两组的治愈情况、视力及角膜散光度。结果 :A组 32眼中 31眼获得临床治愈 ,治愈率 96 .87% ,出现明显纤维增生 1眼 ,占 3.13% ;B组 30眼中 2 4眼获得临床治愈 ,治愈率 80 % ,出现明显纤维增生 4眼 ,占 13.33% ,真性复发 2眼 ,占 6 .6 7%。两组治愈率差异有显著性 (P <0 .0 5 ) ,术前术后视力及角膜散光度差异有高度显著性 (P <0 .0 1)。 结论 :自体角膜缘上皮移植有利于重建角膜缘屏障功能 ,临床疗效优于单纯羊膜移植术。手术切除翼状胬肉能有效地减轻角膜散光 ,提高视力。     

深低温冷冻保存角膜的实验研究

[目的 ]验证二甲基亚砜 (DMSO)是否是目前最好的角膜冷冻保护剂 ,探讨乙醇可否替代DM SA。 [方法 ]16只新鲜兔角膜随机分为DMSO组和乙醇组。将角膜于 4℃分别浸入浓度递增的两组保护液中 ,冷平衡后 ,按 1.5～ 2℃ /min的速度降温至 - 30℃后 ,再以 5℃ /min的速度降温至 -80℃ ,然后 ,将标本瓶投入液氮中冷冻保存角膜 5d。取出后置于 5 0℃流动的热水中快速复温 ,脱保护剂。每组各取 6只角膜 ,经锥兰 -茜素红染色后 ,用光学显微镜计数并计算每只角膜平均内皮细胞存活率 (ESR)。另 2只角膜 ,用 2 .5 %戊二醛溶液固定 ,分别用扫描电镜和透射电镜观察内皮细胞超微结构。 [结果 ]DMSO组和乙醇组平均ESR分别为 (96 .18± 2 .4 9) %和 (92 .5 5± 6 .2 4 ) %(P <0 .0 5 )。扫描电镜下 ,DMSO组角膜内皮细胞呈六角形 ,细胞完整似新鲜角膜 ,细胞间隙稍宽。乙醇组角膜内皮亦呈六角形 ,但细胞间隙明显增宽。透射电镜显示两组角膜内皮细胞均有线粒体肿胀 ,内质网扩张及胞质内空泡形成 ,但乙醇组改变更明显。 [结论 ]本研究提示乙醇对角膜冷冻保存有一定效果 ,但尚不如DMSO。     

以羊膜为载体体外培养大鼠角膜缘干细胞的实验研究

目的 比较角膜缘于细胞(LSCs)在不同羊膜上的生长情况,寻求LSCs体外培养的最佳载体.方法 取健康剖宫产孕妇胎盘的羊膜组织,分别制备保留上皮的新鲜羊膜、去除上皮的新鲜羊膜和冷冻羊膜.消化法分离大鼠LSCs后将其按相同浓度分别种植于3种事先准备好的羊膜载体和无载体孔中,分为4组.实验1组:保留上皮的新鲜羊膜组;实验2组:去除上皮的新鲜羊膜组;实验3组:去除上皮的冷冻羊膜组;对照组:无羊膜载体组.4组细胞分别作细胞凋亡检测,p63、PCNA免疫荧光检测,检测阳性细胞计数.结果 培养第3天,3个实验组培养的细胞排列紧密,融合形成单层,其中可见大小不等的团块状集落,细胞大小基本一致,多呈圆球形或卵圆形.对照组培养的细胞排列相对稀疏,基本融合,形成单层,可见散在的、大小不等的桑葚样细胞集落,集落细胞的生长特征及形态特点与实验组相似.实验组的细胞凋亡率均低于对照组,p63阳性率和PCNA阳性率均高于对照组(P＜0.01),尤以实验1组变化最为明显(P＜0.01).结论 羊膜载体有利于体外培养大鼠LSCs的扩增,保留上皮的新鲜羊膜能更好地维持体外培养LSCs的特性,是体外角膜缘干细胞培养的理想载体.     

Limbal,low-grade myofibroblastic sarcoma: Case report and literature review

Low-grade myofibroblastic sarcoma is a relatively recently-described neoplasm of the myofibroblasts having a predilection for the head and neck region. Ophthalmic involvement is extremely rare. Limbal involvement has not yet been documented in the literature. We describe one such case involving the limbus of a 48-year-old Asian male.     

Moving epithelia: Tracking the fate of mammalian limbal epithelial stem cells

Lineage tracing allows the destiny of a stem cell (SC) and its progeny to be followed through time. In order to track their long-term fate, SC must be permanently marked to discern their distribution, division, displacement and differentiation. This information is essential for unravelling the mysteries that govern their replenishing activity while they remain anchored within their niche microenvironment. Modern-day lineage tracing uses inducible genetic recombination to illuminate cells within embryonic, newborn and adult tissues, and the advent of powerful high-resolution microscopy has enabled the behaviour of labelled cells to be monitored in real-time in a living organism. The simple structural organization of the mammalian cornea, including its accessibility and transparency, renders it the ideal tissue to study SC fate using lineage tracing assisted by non-invasive intravital microscopy. Despite more than a century of research devoted to understanding how this tissue is maintained and repaired, many limitations and controversies continue to plague the field, including uncertainties about the specificity of current SC markers, the number of SC within the cornea, their mode of division, their location, and importantly the signals that dictate cell migration. This communication will highlight historical discoveries as well as recent developments in the corneal SC field; more specifically how the progeny of these cells are mobilised to replenish this dynamic tissue during steady-state, disease and transplantation. Also discussed is how insights gleaned from animal studies can be used to advance our knowledge of the fundamental mechanisms that govern modelling and remodelling of the human cornea in health and disease.     

Maintenance of the corneal epithelium is carried out by germinative cells of its basal stratum and not by presumed stem cells of the limbus

The purpose of this investigation was to analyze the proliferative behavior of rabbit corneal epithelium and establish if any particular region was preferentially involved in epithelial maintenance. [³H]-thymidine was injected intravitreally into both normal eyes and eyes with partially scraped corneal epithelium. Semithin sections of the anterior segment were evaluated by quantitative autoradiography. Segments with active replication (on) and those with no cell division (off) were intermingled in all regions of the tissue, suggesting that the renewal of the epithelial surface of the cornea followed an on/off alternating pattern. In the limbus, heavy labeling of the outermost layers was observed, coupled with a few or no labeled nuclei in the basal stratum. This suggests that this region is a site of rapid cell differentiation and does not contain many slow-cycling cells. The conspicuous and protracted labeling of the basal layer of the corneal epithelium suggests that its cells undergo repeated cycles of replication before being sent to the suprabasal strata. This replication model is prone to generate label-retaining cells. Thus, if these are adult stem cells, one must conclude that they reside in the corneal basal layer and not the limbal basal layer. One may also infer that the basal cells of the cornea and not of the limbus are the ones with the main burden of renewing the corneal epithelium. No particular role in this process could be assigned to the cells of the basal layer of the limbal epithelium.     

骨髓间充质干细胞移植治疗兔角膜缘干细胞缺损的疗效观察

【目的】探讨骨髓间充质干细胞（MSCs）移植治疗兔角膜缘干细胞缺损的疗效。【方法】选取健康的新西兰兔21只,随机分为角膜缘干细胞缺乏MSCs移植组（A组）、角膜缘干细胞缺乏组（B组）和正常空白组（C组）,每组7只,C组不进行操作,A组、B组使用N aO H破坏角膜来建立兔角膜缘干细胞缺乏动物模型,对兔髂窝处骨髓进行骨髓抽吸,利用密度梯度离心分离并培养MSCs ,A组将培养的MSCs接种在明胶载体膜上,利用组织黏合剂α‐氰基丙烯酸脘基酯,使 MSCs的载体与自体兔角膜植片（机械除去角膜缘干细胞）相互黏合,将载有MSCs的移植片缝合在浅层巩膜上;B组只需将球结膜断裂处缝合在浅层巩膜上。观察评估三组动物的眼表形态和角膜组织恢复情况。【结果】三组手术前的眼表形态评分比较无统计学意义（ P ＞0．05）,在术后第一周开始A组眼表形态评分显著高于B组、C组（ P ＜0．05）;三组细胞层数、表层细胞排列、杯状细胞、胶原纤维排列和炎性细胞比较差异均有统计学意义（P ＜0．05）,A组术后角膜组织恢复情况评分显著高于B组（P ＜0．05）。【结论】MSCs移植于角膜缘,能够改善眼表结构的形态,促进角膜缘组织恢复,治疗角膜缘缺损疗效满意。     

自体角膜缘上皮移植与平阳霉素治疗翼状胬肉的比较

目的　观察胬肉切除 +自体角膜缘上皮移植与翼状胬肉单纯切除术 +术前应用平阳霉素治疗翼状胬肉的临床疗效。方法　随机选择翼状胬肉患者共 6 8例 (6 8眼 ) ,随机分为 A组 (32例 ,胬肉切除 +自体角膜缘上皮及结膜移植术 )与 B组 (36例 ,翼状胬肉单纯切除 +术前应用平阳霉素 ) ,观察术后角膜愈合、角膜缘新生血管及球结膜是否有结膜翼状胬肉组织增生。结果　随访 1～ 1.5年 ,A组 32例中 2例复发 (6 .2 5 %) ,B组 36例中4例复发 (11.11%) ,两组比较无显著性差异 (P>0 .0 5 )。结论　胬肉切除 +自体角膜缘上皮移植的目的在于恢复角膜缘干细胞的数量 ,而单纯切除翼状胬肉 +术前应用平阳霉素在于防止翼状胬肉复发 ,两种治疗方法均可行。但角膜缘上皮联合结膜移植术为自体眼表组织移植 ,手术简单安全 ,复发率低 ,是治疗翼状胬肉复发的最佳方法。     

Posterior lumbar apophyseal ring fractures: a report of 20 cases

Posterior apophyseal ring fracture (PARF) of the lumbar spine is an uncommon injury thought usually to occur in adolescence. We analysed CT findings in 20 cases (19 patients), whose age ranged from 16 to 45 years (average 30 years). The PARF could be divided into two distinct groups on the basis of the shape and location of the fracture and the defect of the vertebral rim. In group 1 (2 cases), PARF involved the central aspect of the inferior vertebral rim and bone fragments were large and broad-based. In group 2, PARF were located at the posterolateral margin of the superior vertebral rim and bone fragments were small and focal. The great majority of previously reported cases belonged to our group 1. A pathogenesis for each group is suggested.     

自体角膜缘移植与羊膜移植治疗翼状胬肉

目的 :观察自体角膜缘移植与羊膜移植治疗翼状胬肉的疗效。方法 :为初发性翼状胬肉 2 0例、2 0眼行自体角膜缘移植 ,33例、35眼行羊膜移植 ,随访 5～ 19月 ,平均 12月。结果 :自体角膜缘植片轻度水肿 ,1周内消失 ,2～ 3周巩膜裸露区结膜上皮修复 ,长入新生血管。羊膜植片水肿 ,7～ 10d消失 ,2～ 3周新生血管化 ,无排斥反应发生。随访期内 ,2组均无胬肉复发。结论 :自体角膜缘移植和羊膜移植可有效地阻止胬肉复发。