Objective To analyse the changes of nitric oxide and nitric oxide synthase in rat retina under acute high ocular pressure and study the effect of nitric oxide in rat retinal damage under hypertension. Methods Sixty Wistar rats were divided randomly into five groups:Ocular hypertension 30 min,60 min,90 min and 12 h,24 h after reperfusion．Elevation of the ocular pressure in the anterior chamber of the rat eye ca used retina ischemic damage．The changes of retinal nitric oxide content were ob served indirectly by measuring NO2－/NO3－ content in retina.The distribution and changes of neuronal constitutive nitric oxide synthase (ncNOS)were studied by immunocytochemical localization of ncNOS. Results ncNOS positive neurons were distributed in the inner nuclear layer (INL),ganglion cell layer (GCL) and the inner plexiform layer of the normal and ischemic rat retina.During acute high IOP 30 min,60 min and 90 min,NO content decreased gradually and ncNOS immune activity weakens.During reperfusion,NO content increased remarkably (Plt;0.05) as compared with the groups of hypertension 90 min and decreased remarkably as compared with the normal rat retina.But ncNOS positive neurons continue to decrease compared with the groups of hypertension 90 min. Conclusion NO participates the rat retinal injury by acute elevated intraocular pressure, and nitric oxide synthetized by ncNOS may play an important role in protecting the retina from ischemic and post-ischemic injury.
Objective To explore the effect of ischemia-reperfusion injury on the retinal functions of rats. Methods Seventy Wistar rats were selected, 20 of which were selected randomly and divided into two groups (control group and single-irrigated group). The rats were anesthetized and their anterior chambers of the right eyes were cannulated with a 7-gauge needle connected to a reservoir containing ringers balanced salt solution, which was maintained at the same level o f the eye for 1 hour. After that, ERG was recorded in both eyes of all rats. All the left rats were divided randomly into 10 groups and they were treated as the single-irrigated group. Retinal ischemia was induced by raising the reservoir to a height of 150 mm Hg. One hour later except the single ischemia group, all o f t he groups resumed perfusion after 3,6,12,and 24 hours and 3,5,7,14,and 21 days s eparately. ERG was recorded in both eyes of all rats.Results There was no difference in the results of ERG between left and right eyes in either the control group or the single-irrigated group. All the waves of ERG vanished in the single-ischemia group after 1 hour. In the ischemia-reperfusion groups, the waves of ERG partly recovered and the amplitude reduced persistently and progressively.Conclusion Ischemia-reperfusion injury may affect the function of the retina persistently and progressively. (Chin J Ocul Fundus Dis，2003，19：201-268)
Objective To investigate how to establish stable mice cervical heart transplantation model. Methods Totally, 40 male C57 mice with the age of 6-8 weeks and weight of 19-24 g were randomly divided into recipients and donors (n=20 in each group). Mice cervical heart transplantation model was established by connecting the ascending aorta of donors to the right cervical common artery of recipients through end to side anastmosis and the pulmonary artery of donors to the right external jugular vein of recipients through end to end anastmosis. Results More than 95% recipients survived after surgery. Cold ischemia time was 15±5 min, warm ischemia time 23±6 min, and the whole operation took about 55±15 min. The recipients survived more than 30 d with functional heart grafts. Histologically, there was no difference between the heart graft one month after the transplantion and the normal heart. Conclusion Cervical heart transplantation of mice model is reliable and feasible, which is easy to monitor the survival condition of heart graft by visual examination and palpation, which will benefit the basic research in transplantation field.
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 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 observe the expression of connective tissue growth factor (CTGF) in injured model of retinal pigment epithelial (RPE) cells and the promoting effect of CTGF on migration of RPE cells.MethodsCultured monolayer-confluent human RPE cells were scraped with a trephine and a cotton stick, and set up the injured model of RPE cells with round scraped area. Immunohistochemistry and in situ hybridization(ISH) were used to detect the expression of CTGF protein and mRNA in injured RPE cells at distinct time points after injury. The number of RPE cells migrated to injured area was measured and the effect of CTGF on migration of RPE cells and the effect of dexamethasone (DEX) on the promoting process of CTGF were observed.ResultsThe results of immunohstochemistry and ISH indicated the weak positive expression of CTGF in RPE cells at the edge of scrape 6 hours after injury, and the positive expression increased gradually as time goes by after the injury. Strong positive expression of CTGF in RPE cells at the edge of scrape was found 24 and 48 hours after injury. Rebuilt human CTGF stimulated migration of RPE cells in a dose-depended manner, and DEX significantly inhabited the migration.ConclusionCTGF involves in the procedure of repair of injury of RPE cells, which may play an important role in the pathogenesis of intraocular proliferative diseases such as proliferative vitreoretinaopathy.(Chin J Ocul Fundus Dis, 2005,21:306-309)
Objective To investigate the effect of hepatocyte growth factor (HGF) on the barrier function of retinal peigment epithelium (RPE) and to detect the pathological mechanism of retinal detachment (RD) induced by over expression of HGF in RPE. Methods Sub-retina injection of E1/E3deleted adenoviral vectors encoding HGF (Ad CMV.HGF) and green fluorescent protein (Ad CMV.GFP) in adult pigmented rabbits [5times;104 plaque-forming units (pfu)/eye] to set up the model of retinal detachment. The ocular fundus and pathological changes were observed 3, 7, 14, and 28 days after injection. The expression level of HGF in retina and vitreous body was detected by immunohistochemistry and enzyme linked immunosorbent assay (ELISA). Results In the control eyes injected with AdCMV.GFP, expression of GFP only detected in RPE monolayer. The eyes injected with AdCMV.HGF had b HGF immune positive action in RPE cells at the injection site. The expression level of HGF in vitreous body reached the peak 7 days after injection and decreased to the basic level 28 days after injection. Chronic RD and chronic choroidal inflammation were found in the eyes injected with AdCMV.HGF within the time frame of HGF expression. Proliferative RPE cells were found in subretinal space in the region of RD, and multilayered cellular membranes developed in some eyes. Conclusion Over expression of HGF in RPE may induce chronic serous RD with subretinal proliferation of RPE, which suggests that HGF should be further studied as a target for therapeutic intervention in RD. (Chin J Ocul Fundus Dis, 2007, 23: 193-197)
The existing mazes are mainly used to study the learning and memory of animals. However, there is still a lack of corresponding maze and method in the aspect of the observation and test of aquatic animal robots. For this purpose, the authors have developed a three-dimensional water maze combined with bilayer multi-channel which equips with stratified lines and tick marks. This device is a rectangular structure composed of one square bottom and four rectangular side walls, and the channels of every side wall are composed of one upper channel and two lower channels. The center of the upper channels is in the vertical center line of every side wall, and the two uper channels of adjacent side walls are at 90° degrees with each other, and the two lower channels of adjacent side walls are at 45° degrees with each other. There are stratified lines and tick marks on the side wall to test the spatial location and movement trajectories of aquatic animals. The carp robot was put into the water maze for the underwater experimental detection. The success rates of left and right steering at 135, 90 and 45 degrees as well as forward motion of the carp robots (n = 10) were over 60%. This study showed that the device could be used to observe and test the motion of the carp robot.
ObjectiveTo explore the feasibility of goat tricuspid regurgitation (TR) model by one chordae tendineae cutter via right anterior-lateral minimal incision.MethodsTR model was established in 6 goats with a self-made tricuspid valve chordae tendineae cutter. The goats were placed in a left lateral position and procedure was performed via a right anterior-lateral minimal thoracotomy in the fourth intercostal. Under the guidance of transesophageal ultrasound and digital subtraction angiography, the chordae tendineae of anterior leaflet was cut until moderate to severe regurgitation was confirmed. Echocardiography and laboratory examinations were performed preoperatively, immediately and 3 months after surgery. Additionally, all goats were sacrificed to clarify pathological evaluation.ResultsTR was successfully established in 6 goats. The right atrium pressure increased significantly immediately after surgery (P<0.05). During a follow-up of 3 months, the progression of TR was aggravated (P<0.05), and the annular diameter increased from 2.15±0.23 cm to 2.65±0.20 cm. Overall, there was no statistically significant change in transvalvular gradient and velocity between preoperation and postoperation. Laboratory test results showed no abnormalities between preoperation and postoperation. Autopsy evaluation demonstrated obvioue chordae tendineae transection of the anterior leaflet.ConclusionIt is feasible to establish TR model via a right minimal anterior lateral thoracotomy in the fourth intercostal space. This novel TR goats model will allow investigation of transcatheter interventional device and serve as a chronic model in the future.
This study sought to investigate the in vivo antiviral effect of amantadine (AM) and biphenyl dimethyl dicarboxylate (DDB) on hepatitis B virus (HBV) in HBV replication mice. HBV replication-competent plasmid was transferred into male BALB/c mice by using hydrodynamics-based in vivo transfection procedure to develop HBV replication mouse model. The model mice were matched by body weigh, age and serum levels of hepatitis B e antigen (HBeAg) and were divided into four groups:AM group, DDB group, AM+DDB group and NS group, with the last one as control, and the mice of each group were administered corresponding agent orally twice a day, in a medication course lasting 3 d. On the third day, the mice were sacrificed 4-6 h after the last oral intake. HBV DNA replication intermediates in liver were analyzed by Southern blot hybridization. The serum hepatitis B surface antigen (HBsAg) and HBeAg were detected by enzyme linked immunosorbent assay (ELISA). Compared to the animals in the control group, HBV DNA replication intermediates in liver and HBsAg and HBeAg in serum from the AM and AM plus DDB group of mice decreased, and there was no difference between these two groups of mice. The levels of HBV DNA intermediate from liver and the serum HBsAg and HBeAg between the control and DDB group, however, were not obviously different. In conclusion, the inhibition effect of AM on HBV was detected, but treatment with DDB for 3 days did not influence the viral replication and expression of HBV in the HBV replication mice.