Objective To observe the inhibiting effects of alginate sodiumretinoic acid（AGS-RA）microspheres release system on the laser coagulationinduced subretinal proliferation.Methods RA were dissolved by absolute alcohol,then mixed with 1.5% AGS and made into AGSRA microspheres by a microcapsule electrostatic generator. The parameter of laser injury include irradiation time (0.20 s)，spot diameter (200 mu;ｍ) and output power (420 ｍＷ).Thirty pigmented rabbits were randomly divided into 3 groups (laser injury，experimental and control group).After laser coagulation,AGSRA or blank microspheres were immediately injected into the vitrous of experimental and control rabbits respectively.The height,width and area of 6 retinal spots of laser coagulation at each timepoint were analyzed histopathologically with serial retinal sections at 1,2,3,4,and 6 weeks after laser coagulation.Results Histopathological examination showed that there were morphological and distribution changes of retinal cells in all layers, and localized fibroblasts proliferation in the retina after laser injury. The laserinduced responses in experimental group were much milder（P＜0.01）, while the laser injury group and control group have same width（P＞0.05）and height/area of laser spots（P＞0.05）.Conclusion AGSRA release system can alleviate the subretinal proliferate after laser injury.
OBJECTIVE:To verify the safe dose of cephradine in intravitreal injection.
METHODS:After injecting different doses of cephradine(100mu;g,200mu;g,250mu;g,300mu;g,400mu;g)into vitreous cavity of different group of rabbits the activities of the retinal enzymes (SDH,LDH )on different time (Id,3d, 7d ) were determined respectively, and the histological and ultrastructural changes of retinas were also observed simuhaneously.
RESULTS:The activity of rellnal SDH and LDH was found to be decreased gradually with tbe icreasing of the dosage of intravitreal cephradine. The activities of SDH and LDH were found in the lowest level on tile 3rd and lsl day,but they recover to normal levels on tile 7th day after intravitreal in}eetion in 100mu;g,200mu;g groups,and still lower tban normal in the other groups. Histologically,retinal edema was found both in 100mu;g and 200mu;g groups,but degradation of retinal cells,and loss of cones and rods were round in the 250mu;g, 300mu;g and 400mu;g groups.
CONCLUSION: The safe dose of intravitreal injection of cepbradlnc is 200mu;g.
（Chin J Ocul Fundus Dis,1997,13:139-142 ）
OBJECTIVE:To observe the effect of dexamethasone to intracellular free Ca2+ of frozen RPE cells.
METHODS:The cultured human RPE cells were frozen for 30s at --70deg;C. The RPE cells were loaded with Fura-2/AM and analyzed using a digital imaging microscopy system,the effect of dexamethasone to intracellular free Ca2+ was measured at a serial concentration of 40, 60,100,150,200mu;g/ml.
RESULTS:The concentration of intracellular free Ca in frozen human RPE cells was increased to 18.6%~29.8% by dexamethasone at concenlration of 40mu;g/ml~60mu;g/ml,while was decreased to 28.4%~35.2% at 150mu;g/ml~200mu;g/ml.
CONCLUSIONS:Effect of dexamethasone showed two aspects of effect to frozen
cultured human RPE ceils,that it was inhibitor at high concentration and stimulator at low concentration
（Chin J Ocul Fundus Dis,1997,13: 86-88）
Objective To investigate the effect of ultra-filtration on reducing the matrix effects of the immersionof recombination human acellular dermal matrix (rhADM) on detecting residual bovine serum albumin (BSA) by ELISA.Methods Preparation of rhADM immersion: rhADM were rinsed, and then rhADM immersion were prepared. Physiologicalsal ine was used as immersion medium. Presaturation and ultra-filtration: marked the ultra-filtration tubes as PR1 (presaturation protocol 1), PR2 (presaturation protocol 2) and rhADM, respectively, added 2 mL of 1 mg/mL and 10 μg/mL BSA solution into PR1 and PR2 respectively, and added 2 mL of rhADM immersion into rhADM tubes (rhADM1 and rhADM2). The tubes were then centrifuged at 1 500 × g for 20 minutes. The above steps were repeated for 3 times. Take the inner-tube of ultrafiltration into unused centrifuge tube. Added 4 mL of 10 μg/mL BSA solution in PR1 and PR2 tubes, 4 mL of rhADM immersion in rhADM tubes, centrifuged at 1 500 × g for 20 minutes, and then the filtration was colleted. Detecting BSA concentration: the BSA concentrations of all samples were detected by using the quantitative measure of residual BSA ELISA kit. The recoveries of 10 μg/ mL BSA solution treated by presaturation protocol 1 and 2 were calculated (untreated 10 μg/mL BSA solution was as the basic sample, marked R10 and R20 respectively). The correlation coefficient between the logarithm of the filtrate dilution and the absorbance (A) value was calculated and compared with that of water exact without ultra-filtration. Results The BSA concentration of PR1 and R10 was (23.80 ± 1.58) μg/ mL and (9.04 ± 0.24) μg/mL, respectively. The BSA concentration of PR2 and R20 was (8.64 ± 0.24) μg/mL and (8.12 ± 1.01) μg/ mL, respectively. The average recovery of 10 μg/mL BSA was 263.4% ± 16.9% and 106.5% ± 3.0% when the ultra-filtration tubes were presaturaed by PR1 and PR2 (P lt; 0.01), respectively. The BSA recovery of PR2 met the detecting demand. The correlations between A value and sample dilution were increased, the correlationcoefficient was raised from — 0.727 to — 0.960 after rhADM immersion were treated by ultra-filtration. Conclusion Theresults show that the matrix effects can be reduced effectively by ultra-filtration, indicating that an acceptable recovery of BSA can be acquired when ultra-filtration tube is presaturated by sample water extract.
ObjectiveTo explore the effect of estrogen on the permeability of retinal blood vessel by ovariectomy.MethodsTwenty-two healthy rats were divided into experimental and control group randomly. Estrogen level of rats decreased due to ovariectomy in the experimental group while stabilized by sham-ovariectomy in the control group. The results were confirmed by vaginal epithelium smearing. Retinal vein occlusion was established by photodynamic method, and leakage of Evan's blue in retina was determined by spectrophotometer.ResultsMature value of vaginal epithelium decreased significantly in ovariectomy rats（t=21.008，P=0.000） while not significantly in sham-ovariectomy ones （t=0.319，P=0.756）; the mean leakage of Evans blue was (25.503 0±4.378 47) ng/mg in experimental group, and (17.830 0±4.265 69) ng/mg in the control group, and the difference between the two groups is significant（t=3.969 36，P=0.001）.ConclusionOvariectomy is an useful method to study the effect of estrogen on ocular diseases, and when estrogen level decreases, the permeability of retinal blood vessel increases.(Chin J Ocul Fundus Dis, 2005,21:174-176)
Objective
To investigate the early effects of intervention with tanakan on retinal function in diabetic retinopathy(DR) after laser photocoagulation.
Methods
Prospective random controlled study was performed on 60 Patients (60 eyes) from 23 to 69 years old with DR(phase Ⅲ～Ⅳ). The multifocal electroretinograms (MERG) were tested with VERIS Ⅳ before, the 3rd day and the 7th day after photocoagulation.
Results
No significant differences were found in the latencies and response densities of N1,P1 and N2 between the two groups before photocoagulation. Compared with that before photocoagulation, three days after photocoagulation the latencies in tanakan group had no significant change. The response densities of N1,P1 and N2 reduced and the changes were much smaller than that in control. Three days after photocoagulation, the response densities of P1 and N2 in the central macula 5°area were much higher and the latencies of P1 and N2 were significantly shorter than that in control group. There were no significant differences in the response densities in the 7th day and the differences in the latencies between two groups still existed.
Conclusion
Tanakan may be effective in preventing the retina from damage of retinal photocoagulation in some degree in DR.
(Chin J Ocul Fundus Dis, 2002, 18: 208-211)
ObjectiveTo investigate the protective effect and mechanism of betaxolol on optic nerves after experimental retinal ischemia-reperfused injury.MethodsRetinal ischemia was induced in SD rats by increasing intraocular pressure through intracameral infusion. Sixty-eight rats were randomly divided into 3 groups: normal control (eight rats), 0.25% betaxolol treatment (thirty rats) and saline control group (thirty rats). The latter two groups were subdivided into group 1 day, 3 and 7 days after reperfusion, respectively, with 10 rats in each group. Betaxolol and normal saline was applied to the right eyes of the rats in the treatment group and to the ones in normal saline control group, respectively. The amplitude of bwave of electron retinograph (ERG) was observed and the histological and ultrastructural changes were detected by light and electron microscopy. The expression of neural nitrogen oxide synthase (nNOS) was detected by immunohistochemistry. The content of malonyldialdehyde (MDA) and the superoxide dismutase (SOD) activity were measured by spectrophotometer.ResultsBegan from the first day after reperfusion, in saline control group, the amplitudes of ERG bwave reduced continuously, the histopathological damages of retina were aggravating, the expression of nNOS increased, MDA level increased and SOD level decreased persistently, which significantly differed from the normal control group （P＜0.01）; in contrast to the saline control group, the amplitudes of bwave of ERG in betaxolol treatment group after reperfusion got right obviously（P＜0.01）, with alleviated histopathological damages, decreased nNOS positive neurons（P＜0.01）, decreased MDA content（P＜0.01）, and increased SOD activity （P＜0.01）, in which no statistical significance of nNOS positive neurons was found between the treatment group and normal control group （P＞0.01）. ConclusionBetaxolol, by reducing intracellular overfreight ofCa2+, inhibiting production of NO and elevating the ability of anti-oxidation in rat retina, can protect retinal neurons from ischemiareperfused injury.(Chin J Ocul Fundus Dis, 2005,21:249-252)
Objective
To investigate the influnce of L-arginine (L-Arg) and L-nitro-arginine-methyl-ester(L-NAME) to purified retinal ganglion cells(RGCs) apoptosis of rats cultured in different consistencies of L-Arg and L-NAME.
Method
RGCs from Sprague Dawley (SD) neonatal rats(postnatal 1~5 day) were cultured in assimilative culture solution in vitro and RGCs were purified by Thy1.1 with sheep anti rat FITC monoclonal antibody. RGCs were cultured in different consistencies of L-Arg and L-NAME: 1×10-6, 1×10-5,1×10-4, 1×10-3, 1×10-2 and 1×10-1 mol/L for 24 hours and 48 hours, respectively. The changes of bcl-2, bax and p53 mRNA in RGCs in different consistencies of L-Arg and L-NAME
were demonstrated qualitatively and quantitatively by in situ hybridization, and their apoptosis were detected by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling(TUNEL) method, respectively.
Results
After 24 hours in vitro, the purification rate of RGCs in the experiment arrived at 97 %. After 48 hours, there were a few apoptotic cells expression in the control group. Apoptotic cells expression in L-Arg≥1×10-3 mol/L and L-NAME≥1×10-1 mol/L groups increased that had a significant difference with the control group (Plt;0.05). In the group of L-Arg≥1×10-3 mol/L and L-NAME≥1×10-1 mol/L, the expression of bcl-2 mRNA in RGCs became weaker and weaker as the consistencies were increased, but the expression of bax and p53 mRNA in RGCs became higher and higher and had a significant difference with control group (Plt;0.05).
Conclusion
Lower concentration of L-Arg can promote the growth of purified RGCs in vitro and higher concentration of L-Arg can promote the apoptosis of RGCs.
(Chin J Ocul Fundus Dis, 2002, 18: 137-139)
Objective To investigate inhibited effects of melatonin (MLT) on proliferative activity of retinoblastoma cell line HXORB44 and its related mechanism. Methods HXO-RB44 cells were treated by MLT of different concentration (10-10, 10-9, 10-8, 10-7 mmol/L. Cell counting and tetrazolium dyereduction assay (MTT) were used to determine the effect of MLT on the survival and proliferation of HXO-RB44 cells. Apoptotic nuclei were further analyzed by HoechstPI fluorescence staining. Flow cytometry was used to measure the fluorescent intensity of ROS, cell cycle distribution and apoptosis. Results 10 -6 mmol/L (or exceed) of MLT could inhibit the proliferation of HXO-RB44cells in vitro while 10-7 mmol/L (or below) of MLT couldn't. With the increase of MLT concentration from 10-10 mmol/L to 10-7 mmol/L, HXO-RB44 cells gradually increased the expression of ROS. Hoechst staining showed that 4, 8, 12 and 24 hours after the incubation with MLT, the nuclear pyknosis and nuclear fragmentation increased in HXORB44 cells. The extent of apoptosis was proportional to the concentrations of MLT. Flow cytometry revealed that with the increasing of MLT concentration, G0/G1 and G2/M phase cells increased, S phase cells decreased. The apoptotic rate was also increased. Conclusion 10 -6 M of MLT could inhibit the proliferation of HXO-RB44 cells. This effect may relate to the increased ROS expression, cell cycle arrest at G0/G1 phase and apoptosis of HXO-RB44 cells.
