Influence of Platelet-derived Growth Factor on Lens Epithelial Cell Proliferation and Differentiation

The expression pattern of platelet-derived growth factor (PDGF) and its receptor suggest a role in lens cell proliferation. PDGF is strongly expressed in the iris and ciliary body, situated opposite the proliferative cells of the lens epithelium which express the PDGF- &#102 receptor. In this study, using lens epithelial explant cultures, we report that PDGF can induce a dose and time dependent increase in lens cell DNA synthesis. Culturing lens explants with both PDGF and FGF (a mitogen and differentiation factor for lens cells) resulted in responses greater than those induced by either growth factor alone. PDGF did not induce any changes typical of fibre differentiation; however, in combination with FGF it potentiated the fibre differentiating activity of FGF. Results obtained in this study support previous indications that PDGF has an important role in regulating lens cell proliferation. In addition, PDGF may have a role in potentiating FGF-induced lens fibre differentiation in vivo.     

Combination injuries 2. The risk of pulp necrosis in permanent teeth with subluxation injuries and concomitant crown fractures

Abstract – Background: The reported risk of pulp necrosis (PN) is generally low in teeth with subluxation injuries. A concomitant crown fracture may increase the risk of PN in such teeth. Aim: To analyse the influence of a concomitant trauma‐related infraction, enamel‐, enamel–dentin‐ or enamel–dentin–pulp fracture on the risk of PN in permanent teeth with subluxation injury. Material and Methods: The study included 404 permanent incisors with subluxation injury from 289 patients (188 male, 101 female). Of these teeth, 137 had also suffered a concomitant crown fracture. All the teeth were examined and treated according to a standardized protocol. Statistical Analysis: The risk of PN was analysed separately for teeth with immature and mature root development by the Kaplan–Meier method, the log‐rank test and Cox regression analysis. The level of significance was set at 5%. Risk factors included in the analysis were gender, patient age, crown fracture type, mobility and response to an electric pulp test (EPT) at the initial examination. Results: Teeth with immature root development: The risk of PN was increased in teeth with a concomitant enamel fracture (log‐rank test: P = 0.002), enamel–dentin fracture (log‐rank test: P < 0.0001), enamel–dentin–pulp fracture (log‐rank test: P < 0.0001) and in teeth with no response to EPT at the initial examination [hazard ratio: 21 (95% confidence interval, CI: 2.5–172.5), P = 0.005]. Teeth with mature root development: the risk of PN was increased in teeth with an enamel–dentin fracture [hazard ratio: 12.2 (95% CI: 5.0–29.8), P < 0.0001], infraction [hazard ratio: 5.1 (95% CI: 1.2–21.4) P = 0.04] and in teeth with no response to EPT at the initial examination [hazard ratio: 8 (95% CI: 3.3–19.5), P < 0.0001]. Conclusion: A concomitant crown fracture and no response to EPT at the initial examination may be used to identify teeth at increased risk of PN following subluxation injury.     

Impaired GSH biosynthesis disrupts eye development,lens morphogenesis and PAX6 function

PurposeThe purpose of this study was to elucidate the role and molecular consequences of impaired glutathione (GSH) biosynthesis on eye development.MethodsGSH biosynthesis was impaired in surface ectoderm-derived ocular tissues by crossing Gclc^f/f mice with hemizygous Le-Cre transgenic mice to produce Gclc^f/f/Le-Cre^Tg/- (KO) mice. Control mice included Gclc^f/f and Gclc^wt/wt/Le-Cre^Tg/- mice (CRE). Eyes from all mice (at various stages of eye development) were subjected to histological, immunohistochemical, Western blot, RT-qPCR, RNA-seq, and subsequent Gene Ontology, Ingenuity Pathway Analysis and TRANSFAC analyses. PAX6 transactivation activity was studied using a luciferase reporter assay in HEK293T cells depleted of GSH using buthionine sulfoximine (BSO).ResultsDeletion of Gclc diminished GSH levels, increased reactive oxygen species (ROS), and caused an overt microphthalmia phenotype characterized by malformation of the cornea, iris, lens, and retina that is distinct from and much more profound than the one observed in CRE mice. In addition, only the lenses of KO mice displayed reduced crystallin (α, β), PITX3 and Foxe3 expression. RNA-seq analyses at postnatal day 1 revealed 1552 differentially expressed genes (DEGs) in the lenses of KO mice relative to those from Gclc^f/f mice, with Crystallin and lens fiber cell identity genes being downregulated while lens epithelial cell identity and immune response genes were upregulated. Bioinformatic analysis of the DEGs implicated PAX6 as a key upstream regulator. PAX6 transactivation activity was impaired in BSO-treated HEK293T cells.ConclusionsThese data suggest that impaired ocular GSH biosynthesis may disrupt eye development and PAX6 function.     

国人版角膜接触镜配戴者生活质量量表的研制与评估

目的：研制国人版角膜接触镜配戴者生活质量量表（CLIQ）并评估其信度和效度,分析得分的影响因素。方法：对英国原版CLIQ进行翻译、回译、文化调试,形成国人版量表。采用横断面研究,选择2015年4─12月在温州医科大学附属眼视光医院就诊的角膜接触镜配戴者205例进行问卷调查, 其中再随机选取20例由2名调查员分别进行调查,对问卷数据进行统计分析。结果：回收有效问卷201例。视功能维度因应答率小于50%被删除。量表Cronbach's α系数为0.77,眼部症状维度为0.68, 便利性、经济和情感维度均>0.7,量表Guttmann Split-Half系数为0.89,眼部症状、便利性、经济和情感维度分别为0.75、0.78、0.65和0.93。认知维度Cronbach's α系数和Guttmann Split-Half系数均为 0.49故被删除;删除条目20后健康关注维度Cronbach's α系数和Guttmann Split-Half系数分别为0.68 和0.73。2名调查员之间的评分结果高度相关（r=0.87～0.99,P<0.001）。各条目的条目水平内容效度指数为0.83～1.00,量表的平均水平内容效度指数为0.95。探索性因子分析提取的5个因子分别对应各维度,累计方差贡献率60.43%。眼部症状维度与年龄（r=-0.153,P=0.03）和戴镜年数（r=-0.167, P=0.018）轻度相关,情感维度与戴镜年数轻度相关（r=0.209,P=0.003）。量表总分在不同戴镜年数[（3.60±0.34）年 vs. （3.71±0.32）年,P=0.026、每月戴镜天数[（3.60±0.33）d vs. （3.70±0.33）d, P=0.041]和无/有眼部症状（3.71±0.32 vs. 3.60±0.34,P=0.021）的配戴者间差异有统计学意义。软镜配戴者的经济维度对分高于硬镜配戴者（t=2.588,P=0.017）。结论：删去视功能维度、认知维度和条目20后,CLIQ量表的信度和效度较好,戴镜年数越长、每月戴镜天数越多以及无眼部症状的患者得分较高,硬镜配戴者在花费方面的担忧更多。