Objective
To observe the changes of electrophysio logical results in rabbits with normal and injured photoreceptor due to subretinal implantation of chip.
Methods
Photoreceptor damage was induced by injection with NaIO3 solution in 22 out of 30 rabbits. A chip with the diameter of 3 mm made by the array composed of 90 microelectrodes photodiode and conjoint electrode was implanted into subretinal space or choroid of the right eyes of 22 rabbits with photoreceptor and 4 normal rabbits, and the left eyes were the control. The examinations of local flash-visual evoked potential (F-VEP), local flash-electroretinogram (F-ERG), full-field F-ERG and full-filed F-VEP were measured respectively.Another 4 rabbits underwent biocular extirpation for path ological examination .
Results
In 22 rabbits with photo-receptor damage, the amplitude of the main wave of local ERG was obviously higher in 11 eyes with chips than that in the control ones, and was also higher in 2 eyes with chips of the 4 mormal rabbits than that in the control eyes. No wave was found in an eye with retinal hole on the surface of the chip. The repeataility of main amplitude of local-VEP and full-field F-VEP is not satisfactory; no significant changes were observed between chip-implanted eyes and the control eyes examined by full-filed F-ERG.
Conclusion
The implanted chip may stimulate local retina and induce electrical activities after stimulated by light.
(Chin J Ocul Fundus DIs, 2006, 22: 324-327)
ObjectiveTo observe the expression of interleukin (IL)-17, IL-4 and interferon γ (IFN-γ) in experimental autoimmune uveoretinitis (EAU).
MethodsC57BL/6 mice were immunized with interphotoreceptor retinoid-binding protein 1-20 to induce EAU. The inflammatory reaction before and on 7, 14, 21, 28 days after immunization were observed. The level of IL-17, IL-4 and IFN-γ in the serum were measured by enzyme-linked immune sorbent assay (ELISA). mRNA and protein expression of spleen and retina were analysed using quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blot at the same time, respectively.
ResultsThe most serious inflammatory reaction occurred at the 14th day after immunization. The highest level of IFN-γ in serum, highest mRNA and protein expression of IFN-γ in spleen and retina of mice occurred at day 7 after being immunized. The highest level of IL-17, IL-4 in serum, highest mRNA and protein expression of IL-17, IL-4 in spleen and retina of mice occurred at day 14 after being immunized. The increase degree of IL-17 was more than IFN-γ and IL-4. At 7, 14 and 21 days after immunization, compared with the pre-immunization, the level of IL-17, IL-4, IFN-γ in serum of mice were significantly increased (F=1 817.346, 268.600, 164.621; P < 0.05). There was no difference in the levels of IL-17, IL-4, IFN-γin serum of mice between pre-and 28 days after immunization (P > 0.05). At 7, 14 and 21 days after immunization, compared with the pre-immunization, the protein expression of IL-17, IL-4, IFN-γ in spleen (F=312.67, 114.250, 216.220) and retina (F=271.504, 85.370, 80.722) of mice were significantly increased (P < 0.05). There was no difference in protein expression of IL-17, IL-4, IFN-γ in spleen and retina of mice between pre-and 28 days after immunization (P > 0.05).
ConclusionsThere were IL-17, IL-4 and IFN-γ expression in EAU. IL-17, IL-4 and IFN-γ play a key role in the occurrence and development of the EAU.
Objective To establish the model of pancreatoduodenal allotransplantation in pigs with enteric drainage (ED) and portal venous drainage (PVD). Methods Forty-six hybrid landraces were divided into two groups (donor and recipient groups) randomly, for pancreatoduodenal allotransplantation. Donors were perfused via abdomial aorta without clamping the portal venous outflow with UW solution after heparinization. Whole pancreatoduodenal graft was arvested with segments of abdomial aorta and portal vein and shaped under cold UW solution. Then, the end-to-end nastomosis was performed with the donor iliac artery bifurcation “Y” graft to the recipient superior mesenteric arteries and celiac artery. Furthermore, type Ⅰdiabete model was made by removal of the recipient pancreas. The venous anastomosis was reconstructed between the donor portal vein and the recipient superior mesenteric vein. Meanwhile, the end-to-side anastomosis was performed with the donor common iliac artery bifurcation “Y” graft to the recipient abdomial aorta and the side-to-side intestinal anastomosis was performed between the donor duodenum and the recipient jejunum. External jugular vein was intubated for transfusion. The levels of blood glucose， insulin and glucagon in blood were measured before and during the operation and 1， 3， 5， 7 d after operation. Results Twenty-three cases of pancreatoduodenal allotranplantations were performed on pigs. One died from complication of anesthesia. Success rate of operation was 95.7％.Complications of operation happened in 2 cases in which one was phlebothrombosis, incidence 4.5％and the other was duodenojejunal anastomotic leak, incidence 4.5％. The level of blood glucose increased within 30 min and recovered on the 2nd day after removal of pancreas. The levels of insulin and glucagon decreased within 30 min and recovered on the 2nd day after removal of pancreas. Rejection curred at the 1st day and reached the worst level on the 9th day after transplantation without the change of insulin and glucagon in blood and clinical symptoms of rejection. Conclusion Pancreatoduodenal transplantation in pigs can treat type Ⅰ diabete. ED and PVD can keep the function of endocrine in normal. The technique of duodenal transplantation with ED and PVD may pave the way for the further development of pancreas transplantation in clinic.
Objective To establish a rat model of blood ocular barrier breakdown induced by anterior segment intraocular analogic surgery. MethodsOne hundred and fifty healthy adult male rats were randomly divided into control group and model group, 75 rats in each group. The rats were anesthetized with 1 ml/kg ketamine hydrochloride/xylazine hydrochloride solution. Three way pipes were attached to a phosphate buffer infusion bag and two intravenous catheters. One catheter was inserted 30° obliquely through the transparent cornea anterior to the limbus into the rat's anterior chamber. Then the needle was withdrawn and the sheath was indwelling. Another catheter was connected with a manometer. Intraocular pressure was varied from 0 to 12 mm Hg (1 mm Hg=0.133 kPa) 60 times, 30 times per min. The catheter was removed. The eyes were treated with ofloxacin ophthalmic solution after surgery. The 1st, 2nd, 3rd, 5th and 7th day after surgery, the integrity of the blood ocular barrier was assessed by immunohistochemical staining for albumin and quantitative measurement using Evan′s blue as a tracer. ResultsAlbumin immunohistochemical staining of the control group was confined to the iris and retinal blood vessels. The choroid was stained at each time point after surgery. Albumin immunohistochemical staining of the model group was abundant around the iris and the retinal vasculature on the 1st day after surgery. The albumin diffused throughout the iris and the retina on the 2nd and the 3rd day after surgery. The albumin reached the retinal vessels on the 5th and 7th day after surgery. The aqueous humor Evans blue leakages of the model group were higher than those of the control group on the 1st, 2nd, 3rd and 5th day after surgery. The differences were statistically significant (t=25.781, 37.433, 25.150, 19.171； P<0.01). The Evans blue leakage of the model group was close to that of the control group on the 7th day after surgery. The difference was no statistical significant（t=1.303, P=0.209）. The retinal Evans blue leakages of the model group were higher than those of the control group on the 1st, the 2nd and the 3rd day after surgery. The differences were statistically significant (t=11.997, 14.622, 23.014; P<0.01). The Evans blue leakage of the model group was close to those of the control group on the 5th and 7th day after surgery. The differences were not statistically significant（t=2.027, 0.756; P=0.058, 0.459）. Conclusion This study establishes a rat model of blood ocular barrier breakdown induced by imitating the injury to the anterior segment during intraocular surgery.
Objective To study effects of enteral immunonutrition and econutrition on intestinal mucosa barrier function in wounded rats. Methods Forty Wistar rats were randomly divided into four groups, with ten rats in each group 〔ie.control group, enteral nutrition (EN) group, enteral immunonutrition (EIN) group and enteral econutrition (EEN) group〕. After gastrostomy, rats in each group were treated with the isocaloric and isonitrogenous nutritional formulas for 7 days, respectively. The morphology of ileum membrane was studied, and the quantities of IgA+, CD3+, CD4+ and CD8+ cells (each HP) of ileum membrane were determined. Results The villus height, crypt depth, mucosal thickness (except EN group) and villus surface area of ileum were increased in EN, EIN and EEN group compared with control group (P＜0.05), but there was no significant difference among the former three groups (Pgt;0.05). The numbers of IgA+, CD3+, CD4+ and CD8+ cells were increased in EN, EIN and EEN group compared with control group (P＜0.05), and those numbers in EN group were lower than those in EIN and EEN group (P＜0.05). Conclusion EIN and EEN may improve intestine mechanical barrier function and promote restoration of small intestine mucous membrane barrier function in rats. EIN and EEN also improve intestine immune barrier function and strengthen its immune function.
ObjectiveTo observe the pathological changes in heart and lung tissues in rats with pulmonary hypertension induced by monocrotaline.
MethodsTwenty-four male Sprague-Dawley rats were randomly and equally divided into an experimental group and a control group. The rats in the experimental group were intraperitoneally injected with monocrotaline to induce pulmonary hypertension, and the rats in the control group were treated with saline. All rats were fed for 3 weeks, and the general situation were observed. Then the rats were sacrificed for measurement of mean pulmonary artery pressure (mPAP), right ventricular hypertrophy index [RV/(LV+S)], changes of myocardial cells and lung vascular, calculated density of middle membrane smooth muscle cells (SMC) in medium/small pulmonary arteries accompanied with bronchi and alveoli, media thickness of pulmonary artery (PAMT), the percentage of wall thickness with outer diameter (WT%), the percentage of wall area with total area (WA%), the average diameter of myocardial cells (AD), and myocardial nuclei density (MND).
ResultsCompared with the control group, the condition of rats in the experimental group were getting worse obviously.mPAP and RV/(LV+S) were both increased (both P < 0.05). The observation by light microscope revealed that obvious myocardial hypertrophy and structure disturbances, severe luminal stenosis of medium/small pulmonary arteries, medial thickening, infiltration of inflammatory cell in tissue space, proliferation of unorganized collagen fibers in the experimental group. The observation by electronic microscope showed proliferation of endothelial cell with irregular nuclei, increased organelles and vacuoles in the experimental group. The differences in SMC, PAMT, WT%, WA%, AD, and MND were significant between two groups (all P < 0.05).
ConclusionsThe monocrotaline can induced pulmonary hypertension and right ventricular hypertrophy. The mechanism may be related to severe stenosis or occlusion of the vessel lumen caused by plexiform proliferation of endothelial cells, proliferation of smooth muscle cells and collagen fibers, compensatory hypertrophy and hyperplasia of myocardial cells.
Objective To observe the retinal toxicity of intravitreal injection of Bevacizumab (Avastin) in albino rabbit eyes at different doses. Methods Sixteen New Zealand albino rabbits，thirty-two eyes were divided into four groups at random. Three groups were prepared for Avastin experiment, named A, B, C. Each group received intravitreal injection of Avastin at dose 1.25 mg/0.05ml，2.5 mg/0.1ml and 6.25 mg/0.25 ml respectively. The other group named D served as a control, and accepted intravitreal injection of 0.9% normal saline 0.1 ml. Then test it by electroretinagram (ERG) after 1, 2 and 4 weeks. In addition, each group was removing two rabbitprime;s eyes to observe the retinal morphology and ultra structure by light microscope and transmission electron microscopy after intravitreal injection avastin 1, 2 and 4 weeks. Results The ERG pattern and amplitude of each group were normal after intravitreal injection Avastin 1, 2 and 4 weeks. （P＞0.05）Between study and control groups, there was no significant difference in retinal morphology which was observed by light microscope at any stage of the study. By electron microscopic observation, retinal ultramicrostructure was no evident retinal toxicity being tested both at group A and B (1.25 mg/0.05 ml and 2.5 mg/0.1 ml). But at group C (6.25 mg/0.25 ml), significant mitochondrial swelling and hydropic changes were seen in the inner segments of photoreceptors. And there was no improvement of the pathological changes in four weeks. Conclusion It is safe that intravitreal injection of Avastin in rabbitprime;s eyes at dose 1.25 mg or 2.5 mg at single time. （Chin J Ocul Fundus Dis，2008，24：193-196）
Objective To systematically evaluate the influence of alcohol intervention on the outcome of rats and mice with ischemic stroke. Methods Databases including PubMed, EMbase, BIOSIS and CNKI were electronically searched from establishment dates of databases to June 2012 to retrieve animal experiments on the influence of alcohol intervention on the outcome of rats and mice with ischemic stroke. The relevant studies were identified according to the predefined inclusion and exclusion criteria, the data were extracted, and the quality was evaluated. Then meta-analysis was performed using RevMan 5.1 software. Results Eight studies were included. The results of meta-analysis showed that no significant difference was found between the alcohol intervention group and the control group (MD=?6.98%, 95%CI ?20.38% to 6.43%, P=0.31). However, compared with the control group, low dose of acute alcohol intervention (less than 2 g/kg) improved the prognosis of ischemic stroke with a significant difference (MD=?22.83%, 95%CI ?38.77% to ?6.89%, P=0.005), and highly-concentrated of chronic alcohol intervention worsened the cerebral ischemic damage of rats and mice with a significant difference (MD=24.06%, 95%CI 10.54% to 37.58%, P=0.000 5). Conclusion Low dose of acute alcohol intervention (less than 2 g/kg) could improve the prognosis of rats and mice with ischemic stroke which has the potential neuro-protective effects. However, highly-concentrated chronic alcohol intervention could worsen the cerebral ischemic damage. Due to the limitations of the included studies such as publication bias, the influence of alcohol intervention on the outcome of rats and mice with ischemic stroke could be overestimated.
ObjectiveTo study the feasibility and advantages of preparing an animal model of defecation reconstruction after spinal cord injury in rats by mechanical polishing method.
MethodsForty adult female Sprague Dawley rats (weighing, 250-300 g) were randomly divided into 2 groups (n=20). The lamina was opened by mechanical polishing method to expose the cauda equina in experimental group, then bilateral L5 and S1 nerve roots end-to-end anastomosis was done under 10 times microscope, and finally cauda equina between the L5 and L6 (except S1) was cut. The lamina was opened by traditional bites method in control group, and the other treatment methods were in agreement with the experimental group. The operative time, intra-operative blood loss, and situation of rats at postoperative 3 days were recorded.
ResultsThe operative time of experimental group[(93.05±7.60) minutes] was significantly shorter than that in control group[(131.30±11.68) minutes] (t=12.279, P=0.000); intra-operative blood loss in experimental group[(4.33±0.46) mL] was significantly lower than that in control group[(7.36±0.58) mL] (t=18.293, P=0.000). At 3 days after operation, 18 rats (90%) survived in experimental group, and 12 rats (60%) survived in control group; difference was significant in the survival rate between 2 groups (χ2=4.800, P=0.028).
ConclusionTo establish an animal model of defecation reconstruction after spinal cord injury in rats by mechanical polishing method is feasible, and it has shorter operative time, less blood loss, and lower postoperative mortality than the traditional bites method. But there is a certain learning curve and requirement to master microsurgical techniques.
ObjectiveTo observe the effect of subretinal injection of retinal pigment epithelium (RPE) cells for RPE in mice.
MethodsA total of 30 postnatal day 7 C57BL/6J mice were randomly divided into normal mice group, OIR model group and OIR model cell transplanted group, 10 mice in each group. The OIR model was induced in mice of OIR model group and OIR model cell transplanted group. The RPE cells were subretinal injected into the RPE of mice in OIR model cell transplanted group. At 20 days after the injection, the RPE thickness was evaluated by fluorescence microscope. The expression of RPE65, Bestrophin and zonula occludens-1 (ZO-1) were estimated by Western blot and real-time quantitative PCR (RT-PCR).
ResultsThe thickness of RPE in OIR model mice was thinner than that in normal mice; the thickness of RPE in OIR model cell transplantation mice was significantly thicker than that in the OIR model mice. The results of Western blot and RT-PCR indicated that the differences of protein (F=8.597, 18.864, 25.691) and mRNA expression (F=39.458, 11.461, 34.796) of RPE65, Bestrophin, ZO-1 were statistically significant between OIR model group and OIR model cell transplanted group (P < 0.05).
ConclusionsSubretinal injection of RPE cells can promote RPE thickening. RPE65 and Bestrophin protein relative expression levels increased, ZO-1 protein relative expression levels reduced; mRNA expression levels of RPE65, Bestrophin and ZO-1 genes increased.
