Objective To explore the effect of oxygen inhalation on the retinae of newborn rats and its mechanism.Methods We mimicked the retinopathy of prematurity(ROP) by putting the newborn rats in high concentrated oxygen. One-day old rats were put into the oxygen box with the oxygen concentration of 80% for continuous 7 days; then in air condition for 7 days. The arterial blood oxygen pressure, retinal superoxide dismutase (SOD), and malondialdehyde (MDA) of the rats (1,2,4,7,8,9,11,14 days old) were examined. The diameter of retinal vessels′main branch and the coverage rate of peripheral vessels were measured in 7- and 14-day-old rats by ink perfusion. The retinal neovascularization of rats (8,9,11, 14 days old) were observed by HE staining. The rats of the same age fed in air condition were in the control group.Results The differential pressures of blood oxygen of rats (1,2,4,7 days old) in study group were significantly higher than those in the control group (P＜0.01), while the differential pressures of blood oxygen of rats (8,9,11,14 days old) in study group were lower than those in the control group (P＞0.05). The contents of SOD of the retinae in the rats ( 1,2,4,7,8 days old) were significantly lower than those in the control group(P＜0.01, P＜0.05 ), while the contents of MDA were significantly higher than those in the control group (P＜0.01,P＜0.05). The diameter of retinal vessels′main branch in 7-day rats was 75% of the control group, and the coverage rate of peripheral vessels was 22% of the control group; and was 61% and 73% respectively in 14-day-old rats. The neovascularization could be seen in 16.7% of the rats in the study group and nought in the control group.Conclusion The damage of free radical of the retina in high concentrated oxygen and hypoxia situation after oxygen supply may be one of the most important mechanism of ROP. (Chin J Ocul Fundus Dis，2003，19：269-332)
Objective To detect expression of NF-κB in the inner retina and in vestigate the inhibitoryeffect of pyrrolidine dithiocarbamate on retinal neovascularization in rats. Methods The rat models with retinopathy were set up un der the hypoxia condition, and fluorescein fundus angiography (FFA) was used to observe the retinal neovascularization. The expressions of NF-κB in the inner retina in rats with and without neovascularization were detected by immunohisto chemical method. PDTC was intraperitoneally injected in rats with neovascularization to observe the expression of NF-κB in the inner retina and the effect on retinal neovascularization. Results Hypoxia induced NF-κB activation in the retinal glial cells and endothelial cells. But immuno-staining intensity for NF-κB and adhesion molecules were reduced by PDTC intraperitoneal injection. Retin al angiogenesis in rats were suppressed effectively (P＜0.05). Conclusions NF-κB activation correlates with retinal neovascularization closely. PDTC may inhibit the NF-κB activation and prove beneficial in the treatment of ischemic neovascularization. (Chin J Ocul Fundus Dis，2003，19：201-268)
ObjectiveTo investigate relationship between ultrastructural changes and expression of basic fibroblast growth factor of diabetic retinopathy in rats.MethodsDiabetes was induced in rats with a single injection of streptozotocin (STZ) and divided into normal control group and 1- , 3- and 5- month diabetes group. The paraffin slide was observed by in-situ hybridization and immunohistochemistry, and retinal ultrastructure was examined by transmission electron microscopy.ResultsNo change of retinal ultrastructure was found in the control group. Different degrees of ultrastructure lesion were found in 1-month diabetic rats with fragmental increase of thickness of basement membrane, swelling of endothelial cells and obvions fingerlike processes in the capillary cavity, disconcentration of heterochromatin both in endothelium and pericyte, and swelling and degeneration of mitochondrion. The edema of endothelial cells of 3-month diabetic rats was more serious than that of 1month ones, and the capillary cavity was nearly occluded. In 5-month diabetic rats, the basement membrane was unevenly thickened, or obviously split. The positive rate of in-situ hybridization in 3-month diabetic rats was 77.8% while the positive rate of immunohistochemical stain was 55.6%, which increased to 88.9% in 5-month diabetic rats.ConclusionsThe occurrence of the ultrastructural changes in STZ rats with diabetic retinopathy is earlier than that of the expression of bFGF.(Chin J Ocul Fundus Dis, 2003,19:348-351)
ObjectiveTo investigate the expression and relation of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in rats with diabetic retinopathy.MethodFifty-five Wistar rats were randomly divided into the control group (10 rats), and 1, 3, and 5-month-diabetes group (15 rats in each diabetes group), and the diabetic models were set up. The expressions of VEGF and bFGF were detected by situ hybridation and immunohistochemistry on retinal paraffin sections.ResultsThe results of situ hybridation showed that expression of bFGF was found in 3-month-deatbtes group with the percentage of 77.8%, and 88.9% in 5-month-deatbtes group; the positive expression of VEGF was not found in 3-month-deatbtes group but in 5-month-deatbtes group with the percentage of 66.7%. Immunohistochemistry indicated that the positive expression of bFGF started in 3-month-deatbtes group with the percentage of 55.6%, and 88.9% in 5-month-deatbtes group; the percentage of the expression of VEGF was 33.3% in 3-month-deatbtes group and 88.9% in 5-month-deatbtes group.ConclusionThe expression of VEGF occurs after the expression of bFGF in rats with DR.(Chin J Ocul Fundus Dis, 2005,21:37-40)
Objective To detect the effects of plasmin combined with hyaluronidase or hexafluoride SF6 on inducing posterior vitreous detachment (PVD). Methods Eighteen young pigmented rabbits were randomly divided into group A, B, and C with 6 rabbits in each. All of the right eyes were the experimental eyes and the left ones was the control. The right eyes in group A, B, and C were injected with plasmin 1 U, plasmin 1 U and hyaluronidase 20 U, and plasmin 1 U and SF6 0.5 ml, respectively; while all of the left eyes underwent intra-vitreous injection with balanced salt solution 0.1 ml. The eyes were observed by indirect ophthalmoscopy, slit lamp examination, biomicroscopy, B-ultrasonography, and electroretinography (ERG) before and after injection respectively. At last, the retinal sections were examined by light microscopy, scanning and transmission electron microscopy. Results The results of scanning microscopy showed incomplete PVD in 2 (33.3%) experimental eyes in group A, and complete PVD in 4 (66.7%) experimental eyes in both group B and C, and the positive rate of PVD in both group B and C significantly differed from that in group A (Plt;0.05). The b-wave amplitudes of ERG in the three groups after injection didn’t differ much from that in the control group or before the injection（Pgt;0.05）. The results of transmission electron microscopy and light microscopy indicated unchanged retinal structure. Conclusions Compared with the application of only plasmin, plasmin combined with hyaluronidase or hexafluoride SF6 can induce complete PVD more efficiently and do no harm to the retina. (Chin J Ocul Fundus Dis, 2005, 21: 388-390)
Purpose To study an animal model of retinal sheets transplantation using excimer laser. Methods A layer of pure photoreceptors was got by the use of excimer laser.Then the photoreceptor layer was transplanted to the subretinal space of the adult RCS rats which were an animal model of inherited retinal degeneration.The globes were enucleated one month after transplantation.Sections were made for light microscopic examninations. Results A layer of pure and uniform photoreceptors can be got by the use of excimer laser.The transplanted photoreceptors survived well in the subretinal space. Conclusion Retinal sheets transplantation using excimer laser can provide us with well oriented retinal construction and more photoreceptors after transplantation. (Chin J Ocul Fundus Dis,1998,14:209-211)
The serum activities of 3 cytokines (TNF,IL-1 and IL-6) were observed in 23 patients admitted within 4 days of onset of acute pancreatitis (AP). The results showed that the serum level of 3 cytokines raised in all of the AP patients, significant difference between TNF and IL-1 was abserved at admission and IL-6 did after one week of admission, suggesting that proper cytokine criteria are useful in predicting severity of the disease but the relationship between cytokines and MOF had not established.
Objective To investigate the alteration of protein kinase C (PKC) and endothelin system in early diabetic rats, and the effect of specific PKC inhibitor on the expression of retinal endothelin-1 (ET-1). Methods The rats model with streptozotocin(STZ)-induced diabetes were set up. The expression of retinal PKC was detected by enzyme-linked immunoabsorbent assay (ELISA). The expression of retinal ET-1, ET-3, ET-A and ET-B receptor mRNA was determined by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR). The alteration of retinal ET-1 mRNA after intravitreal injection of PKC inhibitor GF109203X in diabetic rats was also observed. Results The activities of membranous PKC were significantly increased in 2-week diabetic rats compared with that in normal rats（t=3.296 , P=0.008）, while activities of cytosolic PKC were unchangeable（t=0.138, P=0.894）. The expression of retinal ET-1 mRNA was significantly increased（P=0.008）, while no change was found in expression of ET-3, ET-A and ET-B mRNA（P=0.918，P=0.889，P=0.500）. After intravitreal in jection of 10-5、10-6、10-7 mol/L PKC inhibitor GF109203X in diabetic rats, the expression of retinal ET-1 mRNA was decreased in a dose-dependent manner compared with the control rats. Conclusion Activation of PKC and increased expression of ET-1 could be found in the retina of early diabetic rats, and PKC inhibitor could inhibit the expression of retinal ET-1. (Chin J Ocul Fundus Dis，2004，20：168-171)
Objective To investigate the interference effect of nerve growth factor (NGF) on apoptosis of retinal cells in experimental retinal detac hment (RD). Methods Twenty seven Sprague-Dawely rats were selected, and the left and right eyes were in the experimental control group and NGF group, respectively. After the RD model was set up by subretinal injection with sodium hyaluronate, 5mu;l NGF（1mu;g/mu;l）was injected into the vitreous body of the right eyes which were in the NGF group; 5mu;l PBS was injected into vitreous body of left eyes which were in the experimental control group. The injection was performed once every 4 days till the end of the observation period. The eye balls of the 27 rats were extrafted 1.5, 3, 6, 12 hours, 1 day, 2, 4, 8 , 16, and 32 days after the RD model was established. Another 2 rats were selected as the normal control, which underwent none of the injections but eyeball extraction at the end of the observation period. TUNEL and transmission electron microscopy were used to detect the apoptosis of the retinal cells. Cell counts and statis tical analysis were used to assess results. Results Typical apoptosis cells were observed in the early time of RD. Apoptosis was found in each retinal layers, especially in inner and outer nuclear layers. The number of apoptosis cells increased as the time of RD was prolonged（Plt;0.01）. It was also found that apoptosis cells in NGF group were less than that in the experimenta l control group（Plt;0.01）. Conclusion Intravitreous injection exogenous NGF may inhibit the apoptosis of retinal cells in experimental RD. (Chin J Ocul Fundus Dis, 2006, 22: 333-335)
Objective To investigate the clinical characteristics of patients with polypoidal choroidal vasculopathy (PCV) from Central China . Methods This was a retrospective study, and 403 eyes of 362 patients diagnosed as PCV by ocular fundus photography, fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA) and optical coherence tomography (OCT) were enrolled. The general clinical data, fundus manifestation and ocular fundus examinations were statistically analyzed. Results Three hundred and sixty-two cases included 249 males (68.8%) and 113 females (31.2%). Age ranged from 45 to 91 years old, and mean age was (64.81plusmn;9.31) years old. Bilateral lesions were observed in 41 patients (11.3%) and unilateral lesions were observed in 321 patients (88.7%)． In these 403 eyes, typical orangered lesions were observed in 162 eyes (40.2%); yellowishwhite exudate could be found in 185 eyes (45.9%); 268 eyes (66.5%) showed variable degrees of subretinal hemorrhage. Drusen was found in 23 eyes (5.7%), pigment proliferation in 20 eyes (5.0%) and fiber vascular scar in 96 eyes (23.8%). The lesions of 386 eyes (95.8%) located in macular region, 53 eyes (13.2%) in peripapillary area. Lesions presented multifoci in 67 eyes (16.6%). Three hundred and four eyes (75.4%) presented typical polypoidal lesions and 152 eyes (37.7%) with abnormal branching choroidal networks. Hemorrhagic retinal pigment epithelial detachments (PED) were found in 200 eyes (49.6%) and serous PED in 96 eyes (23.8%), both existed in 25 eyes（6.2%）. OCT showed 56 eyes (13.9%) presented cystoid dark chamber between the neurosensory retina and 109 eyes (27.0%) with double-layer sign formed by the separation of retinal pigment epithelium and Bruchprime;s membrane (27.0%). Two hundred and seventy-four eyes (68.0%) were found with conelike elevation beneath the RPE layer and 151 eyes (37.6%) with neurosensory detachment. Conclusions In Central China, the majority of PCV patients were male, unilateral. Most PCV lesions were located in the macula. Subretinal hemorrhage, polypoidal lesions and abnormal choroidal vascular networks were common in the PCV patients. Hemorrhagic PED presented a higher ratio than serous PED.