Objective To observe the survival of human umbilical cord derived mesenchymal stem cells (hUC-MSCs) after injection into the vitreous of rabbits,and the animal safety under those procedures.Methods Twentyseven pigmented rabbits were randomly divided into 3 groups (intravitreal injection 1 week group，2 weeks group and 4 weeks group)， each with 9 rabbits.For each animal the right eye was the experimental eye receiving hUCMSCs injection,while the left eye was the control eye receiving culture medium. The rabbit eyes were examined by slitlamp microscope, indirect ophthalmoscopy, fundus photography, fundus fluorescence angiography（FFA）and Tonopen tonometer before and after injection. hUCMSCs were labeled by CMDil in vitro, and their survival status was measured by confocal fluorescence microscopy, light microscope and transmission electron microscope at 4 weeks after injection. Results Four weeks after injection, a large number of the hUCMSCs were still alive in the vitreous cavity. The overall condition of those rabbits was good. The anterior segment and retina of experimental eyes were normal, without hyperfluorescence, hypofluorescence and leakage in the retina at 1,2 and 4 weeks after injection. There was no significant difference on IOP before and after injection at different time points (P＞0.05), and no obvious changes at cornea, anterior chamber angle,lens,retinal structure by.light microscope and transmission electron microscope examination.Conclusion hUC-MSCs can survive in the rabbit vitreous for four weeks；intravitreal injection of hUCMSCs was safe and feasible.
ObjectiveTo evaluate the security of intravitreal injection with ciproflaxacin to retina.MethodsTweenty-four rabbits were randomly divided into 4 groups with 6 rabbits in each group. 0.1 ml ciproflaxacin in doses of 2 500,5 000,and 10 000 μg was intravitreally injected into the rabbits eyes, retrospectively. And 0.1 ml saline solution was injected into the vitreous body of the rats in the control group. Indirect microscope, light microscope and electroretinogram (ERG) were used to observe the changes of ocular fundus.ResultsNormal results of light microscopy and ultrastructure were found in 250 μg and 500 μg groups; irregularly arranged outer and inner nuclear layers, dropsical or even lost ganglion cells, and ultrastructural changes were in 1 000 μg group. There was no apparent difference of ERG′s a and b amplitudes before and after intravitreal injection with ciproflaxacin in each group.ConclusionIntravitreal injection with ciproflaxacin is safe, and 500 μg or less is the secure dosage in rabbits' eyes. (Chin J Ocul Fundus Dis, 2005,21:180-182)
ObjectiveTo observe the effects of bulbar subconjunctival and periocular injection of dexamethasonone on blood glucose levels of type 1 diabetic mellitus (T1DM)rats. Methods80 healthy adult male Sprague-Dawley rats were randomly divided into GroupⅠ(n=40) and GroupⅡ(n=40). GroupⅠrats received intraperitoneal (IP) injection of streptozotocin to induce T1DM model, while GroupⅡrats received IP injection of citrate buffer solution and was the control group.GroupⅠrats and GroupⅡrats were further divided into four subgroups:A (n=10), a (n=10), B (n=10), and b (n=10). Subgroup-A rats received bulbar subconjunctival injection of dexamethasone, subgroup-a rats received bulbar subconjunctival injection of saline, subgroup-B rats received periocular injection of dexamethasone, subgroup-b rats received periocular injection of saline. After the injection, rats were fasted but could drink water. Tail vein blood samples were collected and the blood glucose level was measured by glucose monitor. ResultsAfter modeling, the blood glucose level of GroupⅠand GroupⅡrats was(9.31±1.79) mmol/L and (5.72±0.80) mmol/L respectively, the difference was statistically significant (P < 0.05). The blood glucose level of GroupⅠrats reached the peak in 3h after injection. In 6-24 h after injection, the blood glucose level of GroupⅠA rats was obviously increased than that of the blood glucose level of Group Ia rats and the difference was statistically significant (P < 0.05). In 3-24 hours after injection, the blood glucose level of GroupⅠB rats was obviously increased than that of the blood glucose level of GroupⅠb rats and the difference was statistically significant (P < 0.05). Comparing the blood glucose level during different injection time between GroupⅠA rats and GroupⅠB rats, between GroupⅠa rats and GroupⅠb rats, the difference was not statistically significant (P > 0.05). In 3-24 hours after injection, the blood glucose level of GroupⅡA rats was obviously increased than that of the blood glucose level of GroupⅡa rats and the difference was statistically significant (P < 0.05); the blood glucose level of GroupⅡB rats was obviously increased than that of the blood glucose level of GroupⅡb rats and the difference was statistically significant (P < 0.05). Comparing the blood glucose level during different injection time between GroupⅡA rats and GroupⅡB rats, between GroupⅡa rats and GroupⅡb rats, the difference was not statistically significant (P > 0.05). ConclusionBulbar subconjunctival injection and periocular injection of dexamethasone could both increase the blood glucose of TIDM rats, but these two injection methods had no differences on the blood glucose level.