Objective To monitor the release of amino acids of the whole retina during and after experimental glaucoma by increasing the intraocular pressure （IOP）． Methods Experimental glaucoma was induced in one of the two eyes of rabbits by increasing IOP at 120 mm Hg for 45 min under infusion of saline in anterior chamber；then the pressure was released and the needle inserted into the anterior chamber was removed，this state was maintained for another 45 min．Every 15 min during the experiment 5 rabbits were killed and experimental eyes were enucleated．Aliquots（20 μl）of the retinal extracts（see below）were mixed with ophthaldialdehyde reagent and analysed for amino acid content by the HPLC method of Wangwei，using a 150 mm×4.6 mm,5 μm C18 column． Results A large increase in the release of glutamate，but not of the other three amino acids monitored，occurred during initial experimental ocular hypertension．It reached peak value of（111.73±17.46）10-5 mmol/g at 15 min of hypertension．15 min after release of intraocular pressure，again，immediately large and specific increase in the concentration of glutamate was reached to（102.96±51.91）10-5 mmol/g．In eyes subjected to paracentesis of anterior chamber，no difference was found between experimental eyes and controls. Conclusion These results suggest that glutamate is triggered by increasing the IOP，and it releases not only during the period of experimental ocular hypertension，but also afterwards. (Chin J Ocul Fundus Dis, 2002, 18: 146-148)
Objectives To investigate the expression of pax-6 in ret ina of in fant monkeys with myopia induced by optical defocus, and to determine the role of pax-6 would play or not in onset and development of myopia and emmetropization.Methods Nine healthy infant rhesus monkeys, aged from 1 to 3 months, were selected and wore spectacle lenses or underwent photorefractive keratectomy (PRK).Transcription polymerase chain reaction method and quantitative analysis were used to determine the expression of pax-6 in the retina with myopia induced by optical defocus in different time, and the result was compared with that in retina without myopia.Results The myopia caused by hyperopic defocus was found. The expression of pax-6 in the retina with myopia induced by optical defocus was significantly higher than that in the retina without myopia（t=3.480，P=0.004）.Conclusions The expression of pax-6 is enhanced by hyperopic defocus in the infant monkey retina, which suggests that pax-6 may be involved in vision-dependent eye growth and emmetropization. (Chin J Ocul Fundus Dis，2003，19：201-268)
Objective To observe the pathological and functional changes of retinal photochemical damages exposed to green flurescent light. Methods The Sprague Dawley rats were continually exposed to green fluorescent light with an illuminancem level of (1 900plusmn;106.9) Lx for 24 hours.The changes of retinal morphology and morphometrics and flash electroretinogram were studied before light exposure and at the 6th hour,6th day and 14th day after light exposure. Results At the 6th hours after light exposure,the outer nuclear layer(ONL)of retina becoma thinner compared with that bfore light exposure.The thickness of ONL decreased by 23.91% and the inner and outer segments appeared disorderly arranged.At the 6th day after light exposure the thickness of ONL is thinner than that at the6th hour,i.e.decreased by 46.6%. At the 14th day after light exposure the thickness of ONL decreased by 42.40%.Flash electroretinogram showed that the amplitudes of a and b wave decreased continuously at the 6th hour and 6th day and unrecovered at the 14th day after light exposure. Conclusion This model might be an ideal one for research on retinal photochemical damage. (Chin J Ocul Fundus Dis,1998,14:101-103)
Objective To set up a new animal model of branch retinal vein occlusion (BRVO), which was quite similar to the clinical features and pathogenesis of this disease. Methods The animal model was set up by laser (krypton green 90 ～150 mW) irradiating a branch of central retinal vein after intravenous injection of photochemical drug (3% rose bengal) to 5 pigmented rabbits, and the model was confirmed by fundus fluorescein angiography (FFA) and pathological examination. Results The model of BRVO was successfully set up, which was confirmed by clinical examination and FFA. Pathological examination showed that the occlusion was caused by intra-venousthrombosis. Conclusion An experimental BRVO model, which has the similar pathological processes of occlusion of central retinal vein and intra-venous thrombosis as those in clinic can be set up by using photochemical method. The method is quite simple, and it offers a better animal model for clinical therapeutic research. (Chin J Ocul Fundus Dis,2002,18:23-25)
PURPOSE:To investigate and changes of the retina and the chorid induced by lipopolysaccharide (LPS)in Lewis rats and to compare the results obtained on tissue wholemounts and sections. METHODS:Immunohistochemistry was carried out both on wholemounts of the retina and the chorid-sclera complex and on ocular sections from normal Lewis rats and those after LPS injection. RESULTS:It was shown on the tissue wholemounts that monocytes were attached to retinal blood vessels and emigrated into the choroid as early as 4hrs after LPS injection. Severe involvement of the retina and macrophages into whole area of these tissues.Furthermore increasing number of major histocompatibility complex classⅡ(MHC classⅡ)positive cells was observed in the choroid.The results on tissue sections revealed that the retina and the choroid were both involved as videnced by infiltration of these cells at some time points after LPS injection. CONCLUSION:Wholemount technique provides undoubtful evidences to show that the retina and choroid are primarily and severely involuted after LPS injection.The endotoxin induced uveitis is,for the first time,presumed to be model for human generalized uveitis. （Chin J Ocul Fundus Dis,1996,12:33-36）
PURPOSE:To measure the concentration changes of tumor necrosis factor a (TNF-alpha;)in vitreous during the development of experimental PVR induced by macrophages and explore the initial and mediated factors which stimulate the cellular proliferation. METHODS:Rabbit PVR model was induced by macrophages and the vitreous was taken at the 7th,14th,21st and 28th day and 4 eyes in each group. The TNF-alpha; levels in vivreous of the above examinated and control eyes were measured with an ELISA kit. RESULTS:The TNF-alpha; level in the vitreous reached its peak 434mu;g/ml at 21st day in the mod-el, then rappidly decreased to 122mu;g/ml at 28th day. CONCLUSION:The changes of TNF-a in the vitreous of the PVR model were parallel to the natrual phases of the development of PVR,indicating TNF-alpha; may play an important role in initiating and mediating the inflammation and cellular proliferation in the vitreous. （Chin J Ocul Fundus Dis,1997,13: 231-233）
Objective To further investigate pathologic mechanism of retinal phototrauma. Methods Twenty Wistar rats were divided into control and experimental groups.Their eyes were extracted in 12，24 and 36 hours after light exposure.HE stained retina samples were examined and TDT-mediated dUTP nick end labelling(TUNEL)method was employed to distinguish apoptotic cells. Results After 12-hour light exposure,slight vesiculation was observed in the rod outer segment of the retinas.After 24-hour light exposure,the outer nuclear layer showed predominant fractured and condensed nuclei and fragmented DNA.After 36-hour light exposure,the rod outer and inner segments were lysed and most of the nuclei in the outer nuclear layer were disappeared. Conclusions Apoptosis of photoreceptor cell is one of the important mechanisms which cause experimental retinal photoinjury of rats. (Chin J Ocul Fundus Dis, 1999, 15: 167-169)
Objective To investigate the expression and significance of T-bet in experimental autoimmune uveoretinitis (EAU). Methods EAU was induced in 24 Lewis rats by immunization with retinal S-antigen (50 μg) and complete Freund′s adjuvant, and another 4 rats were the healthy control. The rats with EAU were executed 7, 12, 15, 21 days after immunization, respectively. Immunohistochemical single and double staining were performed using monoclonal antibodies of T-bet or CD4 on the ocular wholemounts and the consecutive sections of the eye and spleen from both 24 immunized Lewis rats and 4 normal controls. The positive cells were counted under the optic microscope and the data were analyzed by SPSS 11.0 statistic software. Results A few T-bet positive cells were observed in the normal ocular tissues and spleen. The expressions of T-bet in the iris, retina, and spleen increased 7 days after immunization, reached the peak at the 15th day, and decreased at the 21st day, which were higher than those in the control. Double staining on the consecutive sections revealed that most of the T-bet positive cells were positive for CD4 monoclona l antibody. Conclusion T-bet may affect the occurrence of EAU by activating Th1 cells. (Chin J Ocul Fundus Dis，2004，20：172-174)
Objective To observe the growth of orthotopic transplanted tumor in nude mice after stomatin-like protein 2 (SLP-2) expression decreased, and to further study the role of SLP-2 in the development and progression of esophageal squamous cell carcinoma. Methods Using RNA interference technique, esophageal squamous cell carcinoma cell lines with specific expression of SLP-2 and stable expression of luciferase were established. The healthy female nude mice with weight ranging from 19 to 22 g were randomly divided into 3 groups (n=12), 6 mice were used to establish subcutaneous xenografts, and the other 6 mice were used to establish the orthotopic transplanted tumor model (Group 1: cell infected with SLP-2-1 plasmid; group 2: cell infected with SLP-2-2 plasmid; group 3: cell infected with SHGFP plasmid). Index of the experiment end was weight loss and poor general situation in any mouse. Before the nude mice were sacrificed, the luciferase value of the tumor was detected by using in vivo imaging technique. After the nude mice were sacrificed, the primary tumor was removed for pathology examination. Results There was no significant difference in region of interest (ROI) value between the group 1 and group 2 (P=0.943). The ROI value for both groups 1 and 2 was significantly lower than that in the group 3 (P=0.002, P=0.000). The primary tumor infiltrated into the muscularis propria of esophageal was observed in all groups. Conclusion SLP-2 is involved in the development and progression of esophageal squamous cell carcinoma, and the decrease of SLP-2 expression can inhibit the growth of esophageal squamous cell carcinoma.
Purpose To determine the effect of exogenous interleukin-1alpha; (IL-1alpha;) on the retina and its vasculature and VEGF expression in SD rats． Methods IL-1alpha;2．0 ng (20 mu;l) were injected into the vitreous of 8 left eyes of 8 SD rats while steriled PBS were injected into 8 right contralateral eyes of the same rats as control． All eyes were assessed by direct ophthalmoscopy every day and enucleated on the 7 thpostoperative day． Histological examination (hemato xylineosin staining) and immunohistochemical staining with antibody against VEGF antigen were performed， and sections were observed and photographed under light microscopy． Results ①All 8 IL-1alpha; inject ed eyes developed epiretinal membranes and extraretinal neovascularization on the 3 rd postoperative days while none of the 8 control eyes exhibited any a bnormal retinal vascular changes and they were confirmed by HE staining;②Immuno staining identified VEGF express mainly in the inner layer of vessel walls， the epiretinal membranes， the neuroganglional layer and the photoreceptor layer of retina， while the control eyes showed only weak positive staining in the photo receptor layer． Conclusions IL-1alpha; is capable of inducing vitreo retinal neovascularization，and increasing the expression of VEGF in the retina and epiretinal membranes． (Chin J Ocul Fundus Dis, 2001,17:135-137)