猫视网膜脱离后视网膜色素上皮细胞的行为观察

目的 观察猫视网膜脱离后，视网膜色素上皮细胞(RPE)的形态学改变及行为变化。方法 28只猫利用微穿刺技术将0．25％Healon注入到视网膜下腔造成视网膜脱离。脱离0．5～90d的视网膜用3％戊二醛固定，加工成组织切片，光镜和电镜下观察RPE细胞形态学变化。结果 视网膜脱离24h，视网膜色素上皮细胞顶端突起被短而均匀的指样突起所取代，RPE细胞顶端表面开始出现耸起。随着脱离时间的延长，细胞表面的这种耸起变得更加明显。脱离14d，RPE细胞开始向视网膜下腔迁移，1～2个月后，在视网膜下腔可以观察到一些小的RPE细胞团簇。结论 视网膜脱离后，RPE细胞的形态发生迅速改变，并且依赖视网膜脱离的时间呈进行性进展。视网膜脱离能诱导RPE细胞形状发生变化，这种形状改变可能与细胞的增殖行为有关。     

IL-6对培养PVR的视网膜色素上皮细胞生长的影响及地塞米松的调节作用

目的　探讨白细胞介素 6(IL 6)对增生性玻璃体视网膜病变 (PVR)的视网膜色素上皮 (RPE)细胞体外生长的影响 ,以及地塞米松对这种增生的调节作用。方法　将地塞米松加入体积比为 10 %PVR的玻璃体切割物培养的RPE细胞培养板中 ,放射免疫学方法检测IL 6的分泌 ;将IL 6、PVR的玻璃体切割物和RPE细胞共同培养 ,测定掺入的3 H TdR和3 H proline的cpm值 ;用不同浓度的地塞米松、PVR玻璃体切割物和RPE细胞共同培养 ,测定掺入的 3 H TdR和3 H proline的cpm的值。 结果　加入地塞米松培养PVR的RPE细胞合成IL 6的量减少 ;IL 6和PVR的RPE细胞共同孵育后 ,细胞增殖明显 ,胶原合成增强 ;地塞米松抑制培养PVR的RPE细胞增殖和胶原合成 ,且随浓度的增加 ,抑制作用增强。结论　IL 6促进PVR培养的RPE细胞增殖和胶原的合成 ,地塞米松抑制RPE细胞增殖和胶原合成 ,一定程度是通过抑制IL 6合成而发挥作用。     

溶血磷脂酸对人视网膜色素上皮细胞增殖的影响

目的 :探讨建立体外原代培养人类视网膜色素上皮细胞 (RPE)方法。方法 :取自愿者贡献的意外事故成年眼球 ,用 0 .2 5 %胰酶消化获取人RPE细胞、置 15 %胎牛血清的DMEM培养液中培养 ,细胞接近融合状态时进行传代培养。用溶血磷脂酸 (lysophosphatidicacid ,LPA)观察RPE增殖的影响。结果 :RPE原代细胞镜下为圆形 ,大小不一 ,内含较多的色素颗粒 ,胞核无法辨认。原代细胞培养贴壁后第 3天增殖速度明显加快 ,至 4～ 5d即可基本融合 ,细胞浆内色素颗粒则随传代次数增多而逐渐减少。第 3代培养的视网膜色素上皮细胞膜表面可见微绒毛 ,细胞质内细胞器丰富 ,线粒体量多 ,体积较小 ,内外膜分界清晰 ,嵴较短。色素颗粒散在分布于胞浆内 ,多数细胞质内含量较少 ,呈高电子密度包含物。LPA对原代培养的视网膜色素上皮细胞增殖有促进作用。结论 :LPA可促进人类RPE细胞体外培养的增殖 ,第 3代培养的视网膜色素上皮细胞可保留原代细胞的生物学特性     

Effects of PDTC on the Proliferation and PCNA Expression of Human Retinal Pigment Epithelial Cells

Proliferative vitreoretinopathy (PVR) is oneof the most common eye diseases that couldlead tosevere vision i mpairment and tend to cause blind-ness .It has beenfound that the abnormal prolifer-ation of retinal pigment epithelium(RPE) plays akey role in the onset and development of PVR.Under pathologic status ,such as rhegmatogenousdetachment of retina and severe ocular trauma ,RPE cells may migrate and proliferate because ofthe sti mulations of cytokines or chemokines ,thusmay lead to path…     

Modulation of Matrix Metalloproteinase and TIMP-1 Expression by TGF-β1 in Cultured Human RPE Cells

In order to investigate the effects of TGF-β1 on the expression of MMP-2, -9 and TIMP1 in human retinal pigment epithelial (RPE) cells, the third-sixth passage cultured RPE cells were treated with TGF-β~ at different concentrations (0.01, 0. 1, 1.0, 10 ng/mL), the expression of MMP-2, -9 and TIMP-1 mRNA was detected by semi-quantitative RT-PCR assays. MMP-2, -9 and TIMP-1 mRNA were expressed in the cultured RPE cells. The values of MMP-2/β-actin in the cells treated with 0.1, 1.0, 10 ng/mL TGF-β1 were 1.04±0.04, 1.07±0.02 and 1.11±0.03, respectively, significantly higher than in the control group (0. 96±0.03, P＜0. 05-0. 01). The expression of MMP-2 mRNA could be up-regulated by TGF-β1, in a dose-dependent manner. The expression of MMP-9 mRNA in the cultured RPE cells was slightly up-regulated by various TGF-β1 concentrations treatment. The values of TIMP-1/β-actin in the cells treated with 0.01 and 0. 1 ng/mL TGF-β1 were 0. 85±0.01 and 0.97 ± 0.02 respectively, significantly lower than in the control group (1.07±0.04, P＜0.01), indicating that the expression of TIMP-1 mRNA was down-regulated by TGF-β1 at low concentrations. But along with the increase of TGF-β1 concentrations (1.0 and 10 ng/mL), the expression of TIMP-1 mRNA was slightly up-regulated, not significantly different from that in the control group (P＞0.05). It was concluded that TGF-β1 might play an important role in the up-regulation of the expression of MMP-2 in RPE cells and result in a directional shift in the balance between MMP and TIMP. This may be facilitated for RPE cells to migrate in the pathogenesis of vitreoretinopathy.     

Inhibitory Effect of Dexamethasone on TGF-β1 Expression of Rabbit Ciliary Pigment Epithelia Cultured in Vitro

In order to elucidate the effect of dexamethasone on the expression of transforming growth factor-beta1 (TGF-β1) in ciliary pigment epithelial (CPE) cells cultured in vitro, rabbit CPE cells were cultured in vitro, treated with DMEM medium containing 0,1×10-8 , 5×10-8 , 10 × 10-8 and 50×10-8 mol/L dexamethasone respectively for 5 days. The TGF-β1 expression was detected by immunohistochemistry Supervision methods and analyzed semi-quantitatively by HMIAS-2000 image system. As opposed to in vivo, rabbit CPE cells expressed TGF-β1 under cultured circumstance in vitro. The gray scales of the positive yellow staining in the groups of 1×10-8, 5×10-8, 10×10-8 and 50× 10-8 mol/L dexamethasone were 136. 57±4.43, 140. 20±6.10, 142.98±2. 99, 146. 80± 1.68 and 150. 05± 1.94 respectively. When the concentrations of dexamethasone were equal to or higher than 5×10-8 mol/L and, the expression of TGF-β1 was inhibited. 10-7 mol/L dexamethasone showed a significant inhibition. It was suggested that CPE cells possess the potential ability of synthesizing and expressing TGF-β1. The inhibition of TGF-β1 expression by dexamethasone may be beneficial to the treatment of proliferative vitroretinopathy, also exert some influence on the secretion of aqueous humor and ciliary inflammation.     

甘薯花青苷色素的抗氧化活性及抑肿瘤作用研究

目的:为在食品中应用甘薯花青苷色素(SPAC),研究其抗氧化活性及抑肿瘤作用。方法:采用体外实验测定SPAC清除??O2和?OH及抑制丙二醛(MDA)生成的能力。测定SPAC对小鼠血清及皮肤超氧化物歧化酶(SOD)活性、抑制S180生长和血谷胱甘肽过氧化物酶(GSH-Px)活性与MDA生成的作用。结果:在体外实验中SPAC能清除??O2和?OH,与同浓度VC相比,清除率分别提高30.63%和20.57%;小鼠灌胃SPAC后的血清和皮肤细胞中SOD活力分别提高27.30%和13.50%;SPAC对小鼠肉瘤S180有抑制作用,最高抑瘤率达到43.12%;与对照组相比,在用SPAC的抑瘤组小鼠血清中GSH-Px和SOD活性明显提高,MDA降低。结论:SPAC具有抗氧化及抑肿瘤作用,在食品和化妆品中有开发潜力。     

视网膜下液促使视网膜色素上皮细胞膜上蛋白激酶C变化的机制分析

目的：研究视网膜下液（SRF）能否引起体外培养的视网膜色素上皮（RPE）细胞浆内蛋白激酶C（PKC）的激活和转位，探讨SRF与RPE细胞中PKC信号系统变化的关系。方法：实验对象为体外培养的RPE细胞；不同的刺激因素分别在不同的时间刺激RPE细胞，通过细胞裂解和离心获取细胞浆和细胞膜蛋白粗提液，用同位素^32P标记和液体闪烁计数法检测细胞浆和细胞膜PKC活性水平。结果：SRF和佛波酯（PMA）都可以激活RPE细胞浆中的PKC（c-PKC），并使其由胞浆向胞膜转位，但胞膜上PKC（m-PKC）活性峰值水平和出现的时间不同。结论：SRF可引起RPE细胞膜上PKC的活性发生变化，变化的幅度与增殖性玻璃体视网膜病变（PVR）的分级呈正相关。     

脂褐素与年龄相关性黄斑变性

年龄相关性黄斑变性(ARMD)是引起中老年人视力丧失的首要原因,其确切病因尚未明了,故治疗效果不佳。脂褐素随着年龄增长在视网膜色素上皮的积累是眼睛老化的标志,通过光化学作用等影响正常视网膜色素上皮细胞的功能,与ARMD的发生发展有一定联系。本文就脂褐素及其与ARMD的关系进行综述。     

Abrupt visual loss during anti-vascular endothelial growth factor treatment for type 3 neovascularization

AIM: To investigate the incidence of abrupt visual loss and its associated factors, during anti-vascular endothelial growth factor (VEGF) treatment for type 3 neovascularization. METHODS: This retrospective study included 137 eyes that were newly diagnosed with type 3 neovascularization. All eyes were treated with anti-VEGF therapy. Abrupt visual loss was defined as loss of 5 or more lines in best-corrected visual acuity (BCVA) in comparison to the previous visit. The incidence and timing of abrupt visual loss as well as the factors associated with it, were determined. In addition, the BCVA at the final follow-up was compared between the eyes with and those without abrupt visual loss. RESULTS: The mean follow-up period was 42.4±18.9mo after diagnosis, and abrupt visual loss was noted in 22 eyes (16.1%) at a mean of 19.6±13.9mo. Abrupt visual loss was found to be associated with subretinal hemorrhage in 11 eyes (50.0%), development of or increase in the height of pigment epithelial detachment with fluid in 8 eyes (36.4%), and tears in the retinal pigment epithelium in 3 eyes (13.6%). The logarithm of minimum angle of resolution (logMAR) mean BCVA at the final follow-up was 2.07±0.67 (Snellen equivalents: 20/2349) and 1.00±0.55 (20/200) in eyes with and without abrupt visual loss, respectively. BCVA was significantly worse in the eyes with abrupt visual loss (P<0.001). CONCLUSION: Abrupt visual loss is noted in 16.1% of patients with type 3 neovascularization and is associated with poor visual outcome. Additional studies are needed to determine how abrupt visual loss can be prevented.