Objective To investigate the therapeutic effects of throm bolytic drug infusion via carotid artery on experimental central retinal artery occlusion (CRAO), and observe the changes of fibrinolytic activity in the system ic circulation. Methods To dissolve the thrombi in 15 cats (30 eyes) with CRAO established by laser irradiating a branch of central retinal a rtery after intravenous injection of photochemical drugs, urokinase (UK) was dir ectly infused via carotid artery in 5 cats (10 eyes) in group A or intravenously injected in 5 cats (10 eyes) in group B, and isotonic saline solution was intra venously injected in 5 cats (10 eyes) in group C respectively. The patency of the artery was evaluated by fundus fluorescein angiography. Moreover, the changes of fibrinolitic activity in the blood were observed by blood biochemical examination. Results Four hours after UK infusion, the complete repatency proportion was 80% (5 cats 8 eyes) in group A, and 50% (4 cats 5 eyes) in group B. There was significant difference between the two groups. Besides, after the infusion, the indexes of coagulation, fibrinolysis, and anti-fibrinolysis in group A were better than those in group B and C (Plt;0.01). Conclusion In the treatment of experimental CRAO, thrombolytic drug infusion via carotid artery is better and more effective than via intravenous injection, which may provide a new method of thrombolytic drug delivery and animal models. (Chin J Ocul Fundus Dis，2004，20：186-188)
Objective To investigate the protective effect and mechanism of intravitreal injection with cyclosporin-A(CsA) on blood-retinal barrier (BRB) in diabetic rats. Methods A total of 48 Sprague-Dawley male mice at the age of 8-10 weeks were divided into normal group, diabetes mellitus (DM) group, CsA group and DMSO group, with 12 rats in each group. The rats in DM, CsA group and DMSO group were induced with streptozotocin (STZ) injection creating a diabetic retinopathy model. The same volume of citric sodium citrate buffer was injected into the rats in the normal group. Immunohistochemical staining was used to detect the BRB permeability, Western blot was used to measure the protein expression of intercellular adhesion molecule (ICAM-1). Enzyme-linked immunosorbent assay (ELISA) was used to measure the expression of vascular endothelial growth factor 72 hours after injection. Results Compared with the normal group, the BRB permeability, ICAM-1 and VEGF expression were significantly increased in DM group (F=29.350, 29.240, 9.658; P＜0.01). Compared with the DM group, the BRB permeability, ICAM-1 and VEGF expression were significantly decreased in CsA group (t=3.174, 5.000, 3.352; P＜0.05); but there was no obvious change of above indexes in DMSO group (t=0.420, 0.561, 0.312; P＞0.05). Conclusion Intravitreal injection of CsA has protective effects on BRB in diabetic rats. Down-regulated expression of ICAM-1 and VEGF may be the mechanism.
ObjectiveTo explore the method and feasibility of establishing patent ductus arteriosus (PDA) model in Bama miniature pig by using autologous jugular vein, and to provide a large animal model for the development of PDA occluder and the study of pulmonary hypertension associated with congenital heart disease. MethodsFive male Bama miniature pigs weighing about 45 kg were selected to gain the PDA model of the autogenous jugular vein, which was fixed by glutaraldehyde and anastomosed between the ascending aorta and the main pulmonary artery. The patency of PDA was confirmed by echocardiography and angiocardiography immediately and one week after the operation. Two animals were selected to undergo transcatheter closure of PDA via femoral vein 1 week after the operation, and the rest were euthanized to obtain PDA and lung tissue for pathological examination. ResultsThe PDA model was successfully established in all five animals with a success rate of 100.0%. Immediately and 1 week after the operation, echocardiography and angiography showed that PDA blood flow was unobstructed, and hematoxylin-eosin staining showed that PDA endothelialization was good. One week after the operation, two animals were successfully treated with transcatheter femoral vein occlusion. The pathological examination of lung tissue showed thickening of the intima and muscular layer of pulmonary arterioles, thickening of pulmonary interstitium and infiltration of neutrophils. ConclusionIt is safe and feasible to establish a large animal model of PDA by using autogenous jugular vein anastomosis between the ascending aorta and the main pulmonary artery. The model can be used for the development of PDA interventional occlusive devices and the pathophysiological study of congenital heart disease-related pulmonary hypertension.
Objective
To investigate the expression and significance of inducible co-stimulator (ICOS) in experimental autoimmune uveoretinitis (EAU). Methods
EAU was induced in 24 Lewis rats (immune group) by immunization with retinal S-antigen (50 mu;g) and complete Freundprime;s adjuvant, and another 4 rats were in the control group. Anterior segment of the ratsprime; eyes were observed by split microscope every day. Immunohistochemical staining was performed using polyclonal antibodies to ICOS on the sections of the spleen which were obtained from the rats in immune group at the 7th, 12th, 15th and 21st days after immunisation respectively. Western blotting was performed to investigate the dynamic expression of ICOS protein in the spleen. The same procedures were made at the corresponding time points in the rats in control group.
Results
A few ICOS positive cells were observed in the normal spleen. The number of ICOS positive cells in immune group increased obviously at the 7th and 12th days after immunization, reached the peak at the 15th day, and decreased at the 21st day which was still higher than that in the control group. The result of Western blotting showed that the dynamic changes of ICOS protein was identical with the changes of positive-cell number detected by immunohistochemistry.
Conclusions
The enhanced expression of ICOS happens before EAU occurs, which increases when the inflammation occurs and deteriorates, and decreases at the alleviative stage of EAU. It suggests that ICOS participates in the formation, development and disappearance of EAU and plays an important role in the incidence of EAU.
(Chin J Ocul Fundus Dis, 2005,21:114-117)
Objective To observe the inhibitory effect of Bevacizumab on retinal neovascularization in oxygen-induced retinopathy in the mouse. Methods 90 one-week-old C57B L/6J mice were divided into four groups at random. 15 mice in the 1st group as normal control group, 15 mice in the 2nd group as oxygen control group, 30 mice in the 3rd group as high-dose Bevacizumab treatment group, 30 mice in the 4th group as low-dose Bevacizumab treatment group. The 2nd, 3rd and 4th groups were exposed to 75% oxygen for 5 days and then to room air. At the 12th day, One eye of each mouse of two control groups were received an intravitreal injection with Be vacizumab at 2 mu;l、1 mu;l respectively, and the same volume of BSS was injected into the other eye of the mice. The adenosine diphosphatase (ADPase) histochemical technique was used for retinal flat mount to assess the oxygen-induced change s of retinal vessels. The number of the endothelium cell nuclei of proliferative neovascularization was quantified by retinal microtome chromoscopy. Real-time PCR analysis was performed to examine the expression of VEGF mRNA. Results Comparing with oxygen control group, regular distributions, reduced density of retina l vascular and reduced endothelium cell nuclei which extending retinal membrane were observed in the treatment groups(P＜0.001). But the differences between two treatment groups are not statistically significant (P＞0.05). The expression of VEGF mRNA was not significantly different in oxygen control group whatever it whether accepted Bevacizumab treatment or high or low dose (P＞0.05). Conclusion Intravitreal injection with Bevacizumab can effectively inhibits the retinal neova scularization in oxygen-induced retinopathy in the mouse. Intravitreal injection with Bevacizumab might become to the new method to treat retinopathy of premature. （Chin J Ocul Fundus Dis，2008，24：184-188）
Extracorporeal membrane oxygenation (ECMO) is a critical life support technique for patients with severe cardiopulmonary failure. Establishing a stable ECMO animal model is essential to further investigate the effects of ECMO on the body and provide assistance for optimizing ECMO management strategies and preventing complications in clinical practice. In recent years, rats have been widely used to establish ECMO models due to their low cost and good reproducibility. Therefore, this article provided a comprehensive review of literature on the ECMO rat model, including equipment and experimental management strategies. It offers a theoretical foundation for the development of a stable and mature ECMO rat model in the future.
Objective To investigate the effect of inducible nitric oxide synth ase (iNOS) or cyclooxygenase－2 (COX－2) on retinal neovascularization and its possible mechanism in oxygen－induced retinopathy （OIR） mouse model. Methods Retinal neovascularization was induced by oxygen with different concentration. The expression of iNOS, COX－2, matrix metalloproteinases 2 (MMP－2) and vascular end othelial growth factor (VEGF) in the retinae of experimental animals were analyzed by immunohistochemistry, realtime polymerase chain reaction and western blotting technologies. Results The inhibition of COX－2 or iNOS obviously attenuated retinal neovascularization and decreased the expression of VEGF and MMP－2. The iNOS inhibition decreased COX－2 expression, and vice versa. Conclusions COX－2 and iNOS may play a role in retinal neovascularization in OIR mouse model, which may act by regulating the expression of VEGF and MMP－2.
Objective
To quantify the mRNA expression of NMDAR1 gene in the retina of eyes with acute elevation of IOP in rabbit．
Methods
Tweenty-six eyes of 16 rabbits were divided into three groups: Group 1: The IOP of one eye in 10 rabbits was elevated to 60 mm Hg by ante ri or chamber infusion． Group 2: The another eye of the same rabbit in group 1 was maintained the IOP to 20 mm Hg by anterior chamber infusion． Group 3: Unilat eral eyes of six rabbits were enucleated to evaluate the mRNA levels as normal control group． PCR product was identified by Southern blotting and the mRNA expression level was quantified by RT-PCR．
Results
The results revealed no significant difference between group 1 and group 2．
Conclusion
This implies that acute elevated IOP may not affect the mRNA expression level of NMDAR1 gene．
(Chin J Ocul Fundus Dis, 2001,17:50-51)
Objective To observe the inhibition effect of selective cyclooxygenase2 inhibitor（celecoxib）on the experimental choroidal neovascularization（CNV）. Methods Thirty 8-10 weeks old healthy male Brown-Norway（BN）rats were randomly divided into the control, laser and celecoxib group,with 10 rats in each group. At the dosage of 50 mg/kg, celecoxib was gavaged twice per day. After 7 days, experimental CNV was induced by Krypon laser on laser group and celecoxib group. Fundus fluorescein angiography (FFA) was performed on days 3, 7,14,21,30 after laser photocoagulation.On days 21 after photocoagulation, 5 rats in each group were sacrificed and the relative thickness of CNV membranes, the expression of COX-2, vascular endothelial growth factor(VEGF) and matrix metalloproteinase-2(MMP-2) were studied by histopathologic or immunohistochemistry examination.Results On days 21 after photocoagulation, the incidence of CNV in the celecoxib group is significantly lower than that in the laser group (chi;2=7.1068,P=0.0077); the relative thickness of the CNV membranes in the celecoxib group is reduced 41.38% compared to the laser group, the difference is statistically significant (t=16.760 0，P=0.0000).COX-2,VEGF and MMP-2 expression in the CNV membrane of celecoxib group were significantly lower than in control group (t=5.710 0,5.840 0, 8.020 0; P=0.000 0); the COX-2, VEGF and MMP-2 expressions in choroid and retina of control group were weak. Conclusion Prophylactic celecoxib can reduce the expression of VEGF and MMP-2 by inhibiting COX-2, and prevent the CNV induced by laser photocoagulation.
ObjectiveTo investigate the effect of nerve growth factor (NGF) on recuperate of optic nerve after contusion by clamping in adult rabbits.
MethodsSixteen adult rabbits were randomly divided into NGF and the control group with 8 rabbits in each group. After the optic nerve of the right eyes was clamped，tissue engineering nerve containing 0.06 ml NGF（concentration: 5×10-4 g/L, NGF group） and 0.06 ml of PBS (control group) was immediately transplanted into the injured eyes respectively, and 0.02 ml NGF（concentration: 5×10-4 g/L, NGF group）and 0.02 ml of PBS (control group) were injected into the vitreous of right eyes respectively. Flash visual evoked potential (FVEP) test was performed on the eyes 1 day, 2 weeks and 8 weeks after the injury. The number of retinal ganglion cells (RGCs) and changes of optic nerves were observed by light microscopy and electron microscopy at the 8th week after contusion,and a computer-image-analysis system was used to count the optic nerve axons.ResultsThe ratio of amplitude of FVEP of the injured and healthy eyes was 0.765±0.150 in NGF group and 0.494±0.108 in the control at the 2th week after injury with a significant difference between the two groups (Plt;0.05); and was 0.581±0.138 and 0.409±0.119 respectively at the 8th week after contusion with statistical difference between the two groups (Plt;0.05). The results of light microscopy and electron microscopy showed that degeneration of RGCs and optic nerves in the NGF group was lighter than that in the control group 8 weeks after injury, while the amount of optic nerve axons was (10 955±608.7) axons/ mm2 in the NGF group and (7 898±608.8) axons/mm2 in the control with statistical difference between the two groups (Plt;0.05).
ConclusionNGF may redound to the survival of RGCs and regeneration of the axons in some degree, which can promote the recuperation of optic nerve and visual function. (Chin J Ocul Fundus Dis, 2005,21:253-257)
