载细胞甲壳素曲率混合膜修复角膜上皮损伤

背景:研究发现甲壳素是一种比较好的生物材料,但关于甲壳素载角膜上皮细胞混合膜修复兔角膜上皮损伤的研究不多。目的:观察载角膜上皮细胞甲壳素曲率混合膜对兔角膜上皮损伤的修复作用。方法:取18只新西兰大白兔,建立左眼角膜上皮损伤模型,随机分2组,实验组于角膜上皮损伤处植入载角膜上皮细胞甲壳素曲率混合膜,对照组植入甲壳素曲率混合膜。植入后1,3,7 d,观察角膜上皮损伤面积、眼角膜病理组织学及超微结构。结果与结论:1角膜上皮损伤面积:实验组植入后1,3 d的角膜损伤面积明显小于对照组(P<0.05),两组植入后7 d的角膜损伤均全完愈合;2眼角膜病理组织学观察结果:植入后7 d,实验组角膜上皮层和基质层连接紧密,有6层左右上皮细胞层,修复完整,结构整齐,最外层平整光滑;对照组角膜上皮层也和基质层连接紧密,有6层左右上皮细胞层,修复完整,但上皮层层次紊乱,最外层表面不平整;3眼角膜超微结构:植入后7 d,实验组角膜上皮细胞细胞为六边形,排列较紧密,细胞表面平整;对照组角膜上皮细胞也为六边形,表面不平整,细胞之间有间隙;4结果表明:载角膜上皮细胞甲壳素曲率混合膜可促进大白兔角膜上皮损伤的修复。

Niche regulation of corneal epithelial stem cells at the limbus

Among all adult somatic stem cells, those of the corneal epithelium are unique in their exclusive location in a defined limbal structure termed Palisades of Vogt. As a result, surgical engraftment of limbal epithelial stem cells with or without ex vivo expansion has long been practiced to restore sights in patients inflicted with limbal stem cell deficiency. Neverthe- less, compared to other stem cell examples, relatively little is known about the limbal niche, which is believed to play a pivotal role in regulating self-renewal and fate decision oflimbal epithelial stem cells. This review summarizes relevant literature and formulates several key questions to guide future research into better understanding of the pathogenesis of limbal stem cell deficiency and further improvement of the tissue engineering of the corneal epithelium by focusing on the limbal niche.

THE MANAGEMENT OF EPITHELIAL INGROWTHAFTER LASER IN SITU KERATOMILEUSIS

Objective. To investigate the treatment of corneal epithelial ingrowth with flap melt after LASIK. Patients and method. Thirteen eyes of 13 patients with corneal epithelial ingrowth and flap melt after LASIK were treated based on the thickness and the extent of melting of the flap. Nine eyes were treated by lifting the flap and scraping the epithelium in the interface. Three eyes underwent allogenic keratomileusis. The flap was removed in one eye. Results. Recurrence occurred in 2 eyes treated by lifting the flap. The flaps, however, healed normally after retreatment. The grafts healed normally in the allogenic keratomileusis group, except for one eye in which the flap was lost. The corneal epithelium healed over the stromal bed after the flap was removed. Corneal haze of grade 2 was present at 6 months. The uncorrected visual acuity was between 0.3 and 1.0, and the best corrected visual acuity lost 1 to 3 lines. Conclusions. Corneal epithelial ingrowth with flap melt is a severe complication after LASIK. However, with proper treatment, vision can be salvaged in most cases.

Antagomir Dependent MicroRNA-205 Reduction Enhances Adhesion Ability of Human Corneal Epithelial Keratinocytes

Objective To investigate the effect of microRNA-205 reduction by antagomirs on adhesion ability of normal human corneal epithelial keratinocytes(NHCEKs).Methods Antagomir-205,complementary and inhibitory to microRNA-205,was used to suppress endogenous microRNA-205 in NHCEKs.The adhesion ability of treated NHCEKs was then assessed by cell adhesion assay.Immunoblot and immunohistochemistry were conducted to determine the level of two focal adhesion-related proteins,focal adhesion kinase(FAK) and paxillin(Pax).Phalloidin staining was performed to measure the level of filamentous actin in antagomir-treated NHCEKs.Results Antagomir-205 markedly reduced the level of microRNA-205 in NHCEKs and significantly enhanced adhesion ability of NHCEKs(P<0.01).Further protein analysis validated that inhibition of mi-croRNA-205 increased the number of phosphorylated FAK and phosphorylated Pax,and decreased filamen-tous actin.Conclusion Our findings suggest that microRNA-205 has down-regulating effect on cell motility in NHCEKs.

EFFECT OF HUMAN AMNIOTIC MEMBRANE ON CORNEAL EPITHELIUM AND YAC-1 CELL

Objective To study the effect of the amniotic membrane on enhancing the proliferation ofcorneal epithelia and YAC-1 cell. Methods After the primary culture of the rabbit's corneal epithelia and YAC-1 cells, they were seeded on the upper surface or stromal matrix side of amniotic membrane respectively. The proliferation results were observed by MTT test. Results The amniotic membrane was found significantly enhancing the proliferation of corneal epithelia on the d1 ,d3 , and d5 after culture. The proliferation rate was 28.93% ,23.32% ,23.41 % (P<0 .05) respectively, but the d7 proliferation rate was 20.72% (P> 0.05). On the dl , d3 , d7 after culture , the YAC-1 cells proliferation rate was 34 .87% ,36 .28% ,33 .86% (P< 0.01) respectively. Conclusion Our results demonstrated that the amniotic membrane could enhance the proliferation of both corneal epithelia and YAC-1 cells significantly. Although amniotic membrane has been suggested as an ideal material for reconstruction of ocular surface, special attention should be paid during amniotic membrane transplantation for treating ocular surface lesion resulted from epibulbar tumors.

Cytocompatibility of Three Corneal Cell Types with Amniotic Membrane

Rabbit limbal corneal epithelial cells,corneal endothelial cells and keratocytes were cultured on amniotic membrane. Phase contrast microscope examination was performed daily. Histological and scan electron microscopic examinations were carried out to observe the growth,arrangement and adhesion of cultivated cells. Results showed that three corneal cell types seeded on amniotic membrane grew well and had normal cell morphology. Cultured cells attached firmly on the surface of amniotic membrane. Corneal epithelial cells showed singular layer or stratification. Cell boundaries were formed and tightly opposed. Corneal endothelial cells showed cobblestone or polygonal morphologic characteristics that appeared uniform in size. The cellular arrangement was compact. Keratocytes elongated and showed triangle or dendritic morphology with many intercellular joints which could form networks. In conclusion,amniotic membrane has good scaffold property,diffusion effect and compatibility with corneal cells. The basement membrane side of amniotic membrane facilitated the growth of corneal epithelial cells and endothelial cells and cell junctions were tightly developed. The spongy layer of amniotic membrane facilitated the growth of keratocytes and intercellular joints were rich. Amniotic membrane is an ideal biomaterial for layering tissue engineered cornea.

In-vitro cultivation of normal human oral keratinocytes

Abstract:Objective To establish a method for culturing normal human oral keratinocytes.Methods Specimens obtained from healthy humans undergoing oral surgery were dissociated into single cell suspensions by dispase and trypsin. The cells were grown in serum-free medium. Morphological characteristics were studied under light microscope and electron microscope. Cytokeratins were shown by immunohistochemistry.Results Cells could be maintained in culture up to 4-5 passages or 30-50 days. Electron microscope revealed that there were desmosomes and tonofibrils in the oral keratinocytes. The cells showed positive staining for cytokeratin antibody. Conclusion Human oral keratinocytes have been successfully grown in serial culture.

Assessments of tear meniscus height, tear film thickness, and corneal epithelial thickness after deep anterior lamellar keratoplasty

Objective： To assess the lower tear meniscus height（LTMH）, central tear film thickness（CTFT）, and central corneal epithelial thickness（CCET） after deep anterior lamellar keratoplasty（DALK）. Methods： This was a retrospective cross-sectional study of 20 patients who had DALK in one eye over a three-month period. LTMH, CTFT, and CCET of the operated eyes and the unoperated fellow eyes were measured using high-definition optical coherence tomography（HD-OCT）. Correlations between three OCT assessments and age, time following surgery, graft size, bed size, and the number of residual sutures were analyzed. Results： Compared to patients with keratoconus, patients with other corneal conditions had significantly higher CCET in the fellow eye（P=0.024）. For all patients, CCET in the operated eye was significantly negatively correlated with the number of residual sutures（R=-0.579, P=0.008）, and was significantly positively correlated with time following surgery（R=0.636, P=0.003）. In the fellow eye, a significant positive correlation was found between age and CCET（R=0.551, P=0.012）, and a significant negative correlation between age and CTFT（R=-0.491, P=0.028）. LTMH was found to be significantly correlated between operated and fellow eyes（R=0.554, P=0.011）. There was no significant correlation between LTMH and age, bed/graft size, time following surgery, or residual sutures（all possible correlations, P0.05）. Conclusions： Patients with keratoconus tend to have a thinner central corneal epithelium. Corneal epithelium keeps regenerating over time after DALK. DALK did not induce a significant change in tear volume compared with the fellow eye. Postoperative tear function might depend on an individual＇s general condition, rather than on age, gender, bed/graft size, time following surgery, or residual sutures.