Objective To evaluate the inhibited effects of small interfering RNA targeting Rac1 (Rac1-siRNA) on rat retinal neovascularization in retinae. Methods Retinal vein occlusion was induced by retinal photodynamic medthod in 25 Sprague-Dawley rats. Rac1-siRNA vector DNA was injected into the vitrous of one eye of those rats (gene intervention group), and empty vector DNA was injected into the fellow eye (blank control group). Rac1-siRNA vector was injected in other 25 SD rats without retinal vein occlusion (blank intervention group). Two weeks after injection, fluorescein isothiocyanate (FITC)-dextran was perfused into the hearts of all the rats, and the retinal wholemount was made to observe the neovascularization. The numbers of endothelial cells which break through the internal limiting membrane were counted after hematoxylin-eosin staining. Results A massive of neovascularization and FITC leakage were found in blank control group. Small part of neovascularization and a little FITC leakage were observed in the gene intervention group. Retinal vessels were normal in blank intervention group. Compared with blank contrast group and blank intervention group, the difference of the mean numbers of endothelial cells which broke through the internal limiting membrane in the gene intervention group was significant（t=? P=0.000??lt;0.05）. Conclusion Rac1-siRNA can inhibit retinal neovascularization induced by retinal vein occlusion in rats.
Purpose To investigate the development of embryonic stem cells (ESC)in the subretinal space． Methods ESC were cultivated in suspension for 4 days till they developed into cell aggregates,i.e.embryonic body(EB).ESC as well as EB combined with or without RA were respectively transplanted into vitreous cavity and subretina1 space in SD rats,and the subretinal transplanted eyes,transient ischemia-reperfusion injuries were made by ligating the ophthalmic artery for 40 seconds before the transplantation .The experimental eyes were enucleated for histological and immunohistochemical assays after 14～28 d. Results The EB was found to develope into photoreceptors induced by RA in the subretinal space under an ischemia-reperfusion condition，and EB transplantation without RA induction induced multiple differentiations in the subretinal space.The single injection of RA without EB induced hyperplasia of the neural retinal cells.ESC transplanted into vitreous cavity rapidly proliferated and developed into atypical hyperplastic mass. Conclusion EB derived from ESC can differentiate into photoreceptors induced by RA in the host subretinal space under an ischemia-reperfusion condition. (Chin J Ocul Fundus Dis，2000，16：213-284)
Objective To investigate the clinical characteristics of retinalve in occlusion caused by systemic lupus erythematosus (SLE).Methods Visual acuities, fundus examination, antinuclear antibody (ANA), anti-double-stranded DNA（anti-dsDNA）, complement 3 (C3), complement 4 (C4) and erythrocyte sedimentation rate (ESR) were detected in 9 patients (12 eyes) with retinal vein occlusions caused by SLE. Fundus fluorescein angiography (FFA) was performed on 3 patients. Patients with other ocular or general lesions were analyzed.Results Central re tinal vein occlusion (CRVO) in 6 patients (8 eyes) and branch retinal vein occlusion (BRVO) in 3 (4 eyes) were found. The results of FFA showed that 5 eyes of 3 patients had extensive leakage of retinal vein and capillary. Four contralateral eyes of 6 patients with unilateral retinal vein occlusion had SLE fundus alte rations such as cotto-wool spot and retinal hemorrhage. Four patients had xerotic keratitis or ulcerative blepharitis and 8 had general lesions. Positive ANA and anti-dsDNA, and ESR gt;50 mm/h were detected in all the patients. Decreasing C3 in 6 patients and C4in 5 were found. Conclusions SLE is one of the general conditions causing retinal vein occlusion. Visual acuity and barrier of retinal vein and capillary are damaged seriously in patients with retinal vein occlusion caused by SLE, which may be accompanied with other ocular or general lesions. It is suggested that retinal vein occlusion is relative with SLE activity. (Chin J Ocul Fundus Dis，2003，19：201-268)
ObjectiveTo investigate the impact of L-Phenylalanine on the efficiency of retinal pigment epithelial (RPE) cell derivation from human embryonic stem cells (hESCs) and explore the underlying mechanisms. MethodsH1 hESCs were routinely cultured with mTeSR medium and divided into control and experimental groups. When cells reached over-confluence, spontaneous differentiation was triggered using 10% KSR differentiation medium without bFGF. L-Phenylalanine (0.2 mmol/L) was supplemented in the experimental group from the 3rd week. The expression of RPE markers and Wnt signaling components in the two groups was detected by Real time-RCR, Western blot and Flow cytometry analyses. Purified hESC-RPE cells and PBS were injected into the subretinal space of sodium iodine-induced retinal degeneration rats separately. Retinal function was assessed by ERG 6 weeks after the transplantation. ResultsOn the 7th week, much more pigment cell clumps appeared in the experimental group compared to the control group. Within these areas there were monolayer hexagonal RPE cells full of pigment granules. The experimental group showed significantly higher expression of Pax6, MITF, Tyrosinase, RPE65, Wnt3a, Lef1 and Tcf7 genes than the control group (P < 0.01). Higher expression level of MITF and RPE65 proteins and higher percentage of RPE65 (+) cells (P < 0.01) were detected in the experimental group. 6 weeks after sub-retinal transplantation of hESC-RPE cells, the amplitudes of a-b wave in the transplanted eyes were significantly higher than those in the control eyes (P < 0.01) at the stimulus intensity of 3.0 cd·s/m2. ConclusionsL-Phenylalanine effectively promoted the differentiation of embryonic stem cells into retinal pigment epithelial cells, and its impacts on the Wnt/β-catenin signaling pathway may partially explain the underlying mechanisms. Subretinal transplantation of hESC-RPE remarkably improved the retinal functions of retinal degenerative animal models.
Objective：To observe the protective effect of ginkgo bilo ba extrac t (EGb 761), a free radical scavenger, on the photoreceptor cells after lighti nduced retinal damage. Methods：Seventytwo female SpragueDa wley (SD) rats we re randomly divided into 4 groups: normal control group, lightinduced retinal da m age model group, model+physiological saline group, and model+EGb 761 group, with 18 rats in each group. All of the rats except the ones in the control group were exposed to white light at (2740plusmn;120) lx for 6 hours after the dark adap tation for 24 hours to set up the lightinduced retinal damage model. Rats in m o del + physiological saline group and model+EGb 761 group were intraperitoneall y injected daily with physiological saline and 0.35% EGb 761 (100 mg/kg), respec tively 7 days before and 14 days after the light exposure. Apoptosis of photorec eptor cells was detected 4 days after light exposure; 7 and 14 days after light exposure, histopathological examination was performed and the layer number of ou ter nuclear layers (ONL) on the superior and inferior retina was counted. Results：Four days after light exposure, the apoptosis of photorecep tor cells was fou nd on ONL in model, model+ physiological saline and model+EGb 761 group, and w as obviously less in model + EGb 761 group than in model and model+physiologic al saline group. Seven days after light exposure, the layers of ONL on the super ior retina were 3 to 4 in model and model+physiological saline group, and 7 to 8 in model+EGb 761 group; the mean of the layer number of ONL in model+EGb 761 group (6.92plusmn;0.82) was less than that in normal control group (8.40plusmn;0.95) (t=-1.416, P＜0.05), but significantly more than that in model (5.96 plusmn;1.36 ) and model+physiological saline group (5.90plusmn;1.40）（t=1.024, 1.084; P＜0.05). Fourteen days after light exposure, the layers of ONL on the superior retina were 0 to 1 in model and model+physiological saline group, and 3 to 4 i n model+EGb 761 group. The mean of the layer number of ONL in model+EGb 761 group (5.5 2plusmn;1.06) was significantly more than that in model (3.44plusmn;2.15) and model + physiological saline group (3.37plusmn;1.91) (t=2.082, 2.146, P＜0.05). Conclusion：EGb 761 can partially inhibit the apoptosis of pho toreceptor cells, thus exert protective effect on photoreceptor cells.
PURPOSE:To inquire into diagnosis and differentiation method for full thickness macular hole,lamellar macular hole and cystoid macular degeneration. METHODS:Amsler grid,Watzke' s sign and laser aiming beam test were performed in the patients:30 with full-thickness macular hole, 12 with lamellar macular hole and 8 with cystoid macular degeneration. The results were analyzed statistically with method of four table precise probability. RESULTS:The positive rate of Amsler grid,watzke's sign and laser aiming beam test was 100% in ail of the full thickness macular holes,and it was 85%，65%and 0 in lamellar macular holes and cystoid macular degeneration respectively. CONCLUSION: Amsler grid testing was sensitive but not specific,Watzke's sign was more sensitive and specific,and the laser aiming beam tesl was extremely sensitive and specific in clinical diagnosis of full thickness macular hole. （Chin J Ocul Fundus Dis,1996,12: 208-210）
Objective To observe the expression of p53, bcl-2 genes, vascular endothelial cell growth factor（VEGF）, basic fibroblast growth factor（bFGF）, insulin-like growth factor-I （IGF-I）, and the receptors of these factors of retinal vascular endothelial cells (VECs) of 1- to 20-week diabetic rats, and the relationship between the expressions and cell cycle arrest.Methods Retinal sections of diabetic rats induced by alloxan were immunohistochemically stained and observed by light microscopy (LM) and electron microscopy (EM). Dot blotting and Western blotting were used to determine the expression of mRNA, proteins of p53 and bcl-2. Results Under LM, immunohistochemical positive expression of p53 and bcl-2 were found on the vessels of ganglion cell layer and inner nuclear layer of retinae of 8- to 20-week diabetic rats; under EM, these substances were observed depositing in VECs. The retinal VECs also expressed VEGF, bFGF, IGF-I and their receptors. There was no positive expression of other cell types in these retinae, all cell types of retinae in control group, or all cells of retinae of diabetic rats with the course of disease of 1 to 6 weeks. The result of dot blotting revealed that retinal tissue of 20-week diabetic rat expressed p53 and bcl-2 mRNA, and the result of Western blotting revealed that they also expressed p53 and bcl-2 proteins. But retinal tissues of control group did not. Positive expression of bax was not found in the retinae in control group or 1- to 20-week diabetic rats. Conclusion p53, bcl-2 may introduce cell cycle arrest of VECs of retinae in 8- to 20-week diabetic rats. High glucose might stimulate the expression of VEGF, bFGF, IGF-I and their receptors, and the growth factors may keep VECs surviving by self-secretion. (Chin J Ocul Fundus Dis，2003，19：29-33)
Retinal degeneration mainly include age-related macular degeneration, retinitispigmentosa and Stargardt’s disease. Although its expression is slightly different, its pathogenesis is photoreceptor cells and/or retinal pigment epithelial (RPE) cel1 damage or degeneration. Because of the 1ack of self-repairing and renewal of retinal photoreceptor cells and RPE cells, cell replacement therapy is one of the most effective methods for treating such diseases.The stem cells currently used for the treatment of retinal degeneration include embryonicstem cells (ESC) and various adult stem cells, such as retinal stem cells (RSC), induced pluripotent stem cells (iPSC). and mesenchyma1 stem cells (MSC). Understanding the currentbasic and clinical application progress of ESC, iPSC, RSC, MSC can provide a new idea for the treatment of retinal degeneration.
Objective To evaluate and compare the prognosis of idiopathic macular holes (IMH) and traumatic macular holes (TMH) treated by pars plana vitrectomy (PPV).Methods The clinical data of 72 IMH eyes and 55 TMH eyes, which were treated by PPV between November 2001 and December 2007, were retrospectively reviewed. The visual outcomes and macular anatomic closure were evaluated, and their relationships with prognostic factors including the size of macular hole (MH), preoperative visual acuity (VA) and duration of disease were analyzed.Results The closure rate of IMH (100.0%) was significant higher than that of TMH (85.5%) (P=0.001). The postoperative VA of IMH and TMH were (0.25plusmn;0.02) and (0.21plusmn;0.21) respectively,both significantly increased compare to their preoperative VA (t=-6.841,-4.093; P=0.000). VAincreased IMH and TMH eyes had same VA （chi;2=3.651，P=0.07）. PrePPV VAge;0.1 IMH eyes had better outcomes than PrePPV VA＜0.1 IMH eyes （chi;2=12.04, P=0.001）, while PrePPV VA had no effects on TMH outcomes （chi;2=0.371，P=0.486）. IMH eyes with small holes had better outcomes （t=2.476，P=0.016）, and TMH eyes with small holes had better closure （t=-4.042, P＜0.001）. The duration of disease had no significant influence on TMH visual （chi;2=0.704, P=0.401） and anatomic （chi;2=0.166, P=0.684） outcomes. Conclusions PPV is an effective treatment for MH. The closure rate of IMH is higher than that of TMH. The diameter of MH and preoperative VA are major factors for IMH outcomes, and the duration of disease and preoperative VA have no effects on postoperative VA in TMH.