One eye each in 3 groups of 12 pigmented rabbits after bilateral vitrectomy received 0.5mg, 1mg or 2mg triamcinolone acetonide (TA), respectively. The fellow eye received only balance saline solution as control. Ophthalmoscopy and electroretinography were performed during 1 day to 38 days after vitrectomy and drug injection. Light and electronmicroscopic studies were done on the 28th day. The particles of drug were visible on day 28 in all TA-treated eyes. Administration of 0. 5rug and 1mg TA did not result in different changes in ERG b-wave amplitudes compared with those in control eyes(P＞0. 05). There were significant elevations of ERG b-wave in 2mg TA eyes compared to the control eyes(Plt;0.05), Both ligbt and electronmicroscopy of the retina in these groups were almost normal. The results showed no Toxielties in TA treated eye up to 2mg after vitrectomy. This offers the experimental evidence as a baseline for combining TA with vitrectomy to reduce recurrence of proliferative vitreoretinopathy. （Chin J Ocul Fundus Dis,1996,12: 105- 107）
Objective To provide a reliable experimental model for gastroesophageal reflux (GER) study. Methods Twenty Japan 5-month-old male rabbits wererandomly divided into two groups: group cardiomyotomy(n=10), group partial cardiomyectomy(n=10). The operations of cardiomyotomy and parital cardiomyectomy were performed in 2 groups respectively. All the animals underwent intraesophagealpH detection 1 week before operation and 4 weeks after operation. The mean changes of reflux ratios were compared between before operation and after operation.Results In gastroesophageal reflux ratio between before operation and after operation, there was no significant difference in group cardiomyotomy (1.98%±1.52% and 4.32%±2.39%, Pgt;0.05) and there was significant difference in group partialcardiomyectomy（1.56%±1.57% and 13.56%±3.27%, Plt;0.05）. Conclusion The reliable experimental model of GER can be made with procedure of partial cardiomyectomy. It can be used in estimating the operative procedure of antireflux and is conducive to dynamic observation and study of esophagitis.
Objective To study the effect of decorin in the suppression of postoperative flexor tendon adhesion. Methods Eighteen Japanese large ear white rabbits underwent complete transection of the Ⅱ digit flexor digitorum profundus tendon in zone Ⅱ and defects immediately were repaired using the modified Kessler technique with -0 nonabsorbable monofilament suture. The site of the right repaired tendon was then injected with 100 μl of decorin(0.25mg/ml) as test toe, the site of the left repaired tendon with 100 μl of PBS as control toe. Inevery group, rabbits were killed and the feet were prepared for biomechanical testing, macroscopic examination and histological inspection. Results In every group, biomechanical testing demonstrates that the sliding distances and the rangs of motion significantly increased in the test toe compared with the control toe(Plt;0.05); macroscopic examination demonstrated that the tendon adhesions of the test toe were significantly reduced when compared with the control toe. In the tese toe, hematoxylin and eosin staining revealed that the hyperplasia of fibroblast was significantly delayed and the collagen fibrils arranged regularly and hadthe normal diameters. Conclusion Decorin can significantly reduce the flexor tendon adhesion formation, adjust collagen fibrillogenesis and promote the tendon healing.
OBJECTIVE To assess the treatment effect of sodium hyaluronate (HA) on experimental temporomandibular joint (TMJ) osteoarthritis of rabbits in comparison with prednisolone (PS). METHODS The upper compartments of both TMJs of 12 Japanese White Ear Rabbits were injected with 0.2 ml of 1.6% papain, 3 days after the right TMJs were injected again with same amount of papain to induce osteoarthritis with different severity levels. Except 1 rabbit was died accidentally. After one week from final injection of papain, the upper compartments of both TMJs of 6 rabbits were injected with HA 1.3 mg, 5 rabbits with PS 1.6 mg weekly for 4 times. At 3, 5 and 7 weeks after the final injection, the rabbits were sacrificed and the TMJs were pathologically examined. RESULTS The TMJs receiving PS showed predominant structural disorganization, and the right TMJs had much severe pathology. The manifestations were fibrillation, thinner or flaking of the articular cartilage of the temporal part of the joint, and the articular surface was covered with fibrous tissue. Whereas the TMJs receiving HA injections demonstrated limited changes of cartilage, less fibrillation, only local loss of cartilage on outside layer of the surface. In vicinity of the defect area, cluster of the chondrocytes appeared. Pathological scores of the TMJs receiving HA were significantly less than those of the TMJs revieving PS. CONCLUSION The results suggest that hyaluronate have effect of cartilaginous reparation and protection for the osteoarthritis of rabbit. While prednisolone has no help or worsened for articular cartilage reparation.
Objective To explore the possibility of small intestinal submucosa (SIS) for reconstruction of urethral defect. 〖WTHZ〗Methods Twenty-four male rabbits weredivided into 4 groups: group A (the tubulate SIS graft for urethral repair), group B (control group, urethral tubulate defect), group C (the SIS patch graft forurethral repairs), group D (control group, urethral part defect). Then the regenerative segment was studied with histological technique by hematoxylineosin straining and immunohistological straining for α-actin after 6 and 12 weeks postoperatively. The retrograde urethrography and urodynamics were used to evaluate the function of the regenerative urethra at 12 weeks after operation. Results In groups A and C, at 6 weeks after operation, the luminal surface of matrix was completely covered by urothelium, minimal SIS graft was observed in the extracellular matrix, new smooth-muscle cells was confirmed; however, more inflammatory cells were observed in the host-matrix anastomosis in group A than in group C. At 12 weeks postoperatively, the regenerative tissue was equivalent to the normal urethral tissue and SIS disappeared in group C, but some minimal SIS grafts were observed in group A. In groups B and D, urethral strictures and fibrous connective tissue were observed except ３ cases. The urethrography showed wide smooth urethral in group A and C, meawhile urodynamic evaluation didn’t demonstrat significant difference(P＞0.05) in the bladder volume and the maximum urethral pressure between preoperation and postoperation in group A or group C. Conclusion SIS can be a useful material for urethral repair in rabbits, the SIS patch graft is superior to the tubulate SIS graft in urethra reconstruction.
Objective To explore the biocompatibility of poly(lacticacid/glycolic acid/asparagic acid-co-polyethylene glycol) biomaterials (PLGA-ASP-PEG) and biological behaviors of cultured marrow stroml stem cells (MSCs) combined with this new type of scaffold in tissue engineering. Methods The PLGA-ASP-PEG tri-block copolymers were obtained through bulk ringopening copolymerization method.MSCs were isolated from the bone marrow of 4 week old New Zealand rabbits. The 3rdgeneration MSCs were cultured combining with PLGA-ASP-PEG in vitro, while cells cultured in PLGA as control group. The cell adhesion rate and the adhesivepower were examined by conventional precipitation method and micropipette aspiration technique respectively. The morphological features were studied by scanning electron microscope. The proliferation behavior of the cells was analyzed by MTT assay. The cell cycle, proliferation index, DNA index and apoptosis of the cells were detected by flow cytometry. The synthesis of protein and collagen were examined by Coomassie Brilliant Blue dyes and 3H-Proline incorporation test. Results The MSCs adhered and grew well on the surface of the biomaterial PLGA-ASP-PEG. The powers of cell adhesion, proliferation and protein and collagen synthesis of the cells were all significantly higher than those of PLGA group (P＜0.05), but the apoptosis rate was significantly lower than that of PLGA group (P＜0.05). The DNA indexes showed the cells of both PLGA-ASP-PEG group and PLGAgroup were normal diploid cells. Conclusion PLGA-ASP-PEG showedgood biocompatibilityand the biological properties improved greatly compared with the PLGA scaffold materials. These results demonstrated that the promise of PLGAASPPEG canbe used as an ideal scaffold material for construction of tissue engineered bone to restore bone defects in bone tissue engineering．
Objective Platelet-rich plasma (PRP) contains high concentrations of platelets and leucocytes, which play a key role in antimicrobial host defense system. To evaluate the antimicrobial efficacy of autologous PRP in vitro and in vivo and to explore the mechanism of action so as to provide the experimental basis for the prevention and treatment of bone infection. Methods PRP was prepared with the method of two centrifugation from 15 health volunteers. Platelet-leukocytegel (PLG) was obtained after activation of PRP with bovine thrombin. Next, PLG was incubated with Staphylococcus aureus (1 × 106 cfu/mL) in vitro compared with PRP, platelet-poor plasma (PPP) and PBS. Samples were taken out after 2, 4, 6, 8, 12, and 24 hours for bacterial culture and colony count. Thirty-six New Zealand adult rabbits, weighing (2.85 ± 0.11) kg, were divided into 4 groups: PLG (n=10), antibiotic (n=10), infection (n=10), and PBS (n=6) groups. The osteomyel itis models were made by injecting 0.1 mL Staphylococcus aureus suspension (1 × 106 cfu/mL) into the tibial canal in PLG group, antibiotic group, and infection group; equal volumes of PBS was injected in PBS group as a control. Autologous PLG was injected immediately after operation in PLG group. Cefazol in (30 mg/kg) was injected through the auricular vein from 1 hour before operation to 72 hours after operation in antibiotic group, once per 8 hours. No treatment was given in infection and PBS groups. The efficacy of PLG for osteomyel itis prophylaxis was evaluated by microbiological, X-ray and histological observation within 28 days. Results The contents of leucocyte and platelet of PRP were 6.2 times and 5.5 times of whole blood, showing signficant differences ((P lt; 0.05); the contents of leucocyte and platelet of PPP were significantly lower than those of whole blood and PRP ((P lt; 0.05). In vitro test showed that PLG had the most obvious bacteriostasis effect. The bacterial count reached a minimum value at 4 hours after incubation in PLG and at 6 hours after incubation in PRP. PPP had slow and no obvious bacteriostasis effect and PBS had no bacteriostasis effect. At 2, 4, 6, 8, 12, and 24 hours of incubation, the bacterial count reduced significantly when compared PLG with PRP and PPP (P lt; 0.05), when compared PRP with PPP (P lt; 0.05). In PLG group and antibiotic group, 1 rabbit died, respectively; 34 rabbits survived to the end of the experiment. There was no significant difference (P gt; 0.05) in temperature, body weight, erythrocyte sedimentation rate and content of leucocyte between 28 days after operation andbefore operation in 4 groups. After 28 days, the X-ray scores were 2.78 ± 1.39, 1.55 ± 1.48, 4.17 ± 1.25, and 0 in PLG, antibiotic,infection, and PBS groups, respectively, which was significantly higher in infection group than in other 3 groups ((P lt; 0.05). Also, the histological scores were 5.89 ± 3.92, 3.00 ± 2.31, 10.33 ± 4.03, and 0, respectively, which was significantly higher in infection group than in other 3 groups (P lt; 0.05), and was significantly lower in antibiotic group than in PLG group ((P lt; 0.05). The results of bacterial culture showed that the infection rates of PLG group (44.4%) and antibiotic group (20.0%) were significantly lower ((P lt; 0.05) than that of infection group (88.9%). The quantitative analysis of bacteria showed that the number of bacteria was signifcantly lower ((P lt; 0.05) in PLG and antibiotic groups than in infection group. Conclusion PRP forms into PLG after activating, it can inhibit Staphylococcus aureus reproduction in vitro and can effectively prevent bone infection in vivo.
PURPOSE:To investigate the approaches for transplanting retinal pigment epithelium. METHODS,Retinal pigment epithelial eells(RPR)of pigmented rabbits' eyes prepared by rotalne preparation of our institute,were transphmted in 18 unpigmemed rabbits'eyes.Eight eyes were undergone outer approach, i.e., transplanting the RPR cells to the subretinal space of recipient eyes by way of perforating sclera and choroid;while 10 eyes were undergone internal approach by way of the routine procedure of vitrectomy with making artificial localized retinal delachment. Light and transmisskm electrone microscopy examination were done at 10th, goth, 40th and 90th day after the operation. RESULTS: In internal approach group,tbe operated eyes,revealed no difference in thickness of the neural retinal layer in transplanted and non-transplanted area 40 days after operation tinder light microscope. Transmission electrone microscopy revealed postoperatively the transplanted RPE cells attached to the Brucb's membrane and the outer segments of photoreeeplive ceils located at a normal position at the 40th dayland the secondary lysozymes with engulfed outer segment were found in the Iransplamed cells at the 90th day. Tbe outer approached operations in eight eyes were failed owing to ehoroid hemorrhage or perforation of retina. CONCLUSION:The internal appraach procedure is much effebtive and practical for transplantation of RPE cells. （Chin J Ocul Fundus Dis,1997,13:160-162）
【Abstract】 Objective To establ ish a stable animal model for glucocorticoid-induced avascular necrosis of femoral head in rabbits. Methods Thirty-six adult New Zealand rabbits were randomly divided into four groups:ten were injected twice with l i popolysaccharide (group A), ten were treated with a combination of l i popolysaccharideand methylprednisolone (group B), ten were injected three times with methylprednisolone (group C), and six wereinjected normal sal ine as a control (group D). MR imaging was performed in the rabbits before the first injection ofl i popolysaccharide or methylprednisolone, and at 2, 4, and 6 weeks after the last injection of l i popolysaccharide ormethylprednisolone. Histopathological changes in the femoral heads were observed by l ight microscope and transmission electron microscope at the end of six weeks after the injection. Vascular infusion with Chinese ink was made to evaluate the morphological changes of blood vessels in the femoral head. The percentage of trabecular bone area and empty lacunae and microvascular density were measured. According to the histological and MR imaging appearance of the femoral heads in all groups, the incidence of osteonecrosis of every group was calculated. Results Listlessness, blepharal hyperemia,less activity and reduced diet were found in the rabbits of groups A and B after injected with l ipopolysaccharide. At 3 weeks after the final injection, the body weight of groups B and C was decreased. At 4 weeks after the final injection, the body weight of groups A and D was increased. No abnormal signal could be detected on MR images in rabbits of all groupsbefore injection and at 2 weeks after the injection. At 4 weeks and 6 weeks after the last injection, irregular low signal on T1-weighted images and irregular low or high signal on T2-weighted images could be detected on MR images in rabbits of groups B and C, no abnormal signal could be detected on MR images in rabbits of groups A and D. At 6 weeks after the last injection,the trabecular bone of group B became thin and sparse, some were broken. The percentages of empty lacunae were 11.8% ± 4.7%, 34.4% ± 6.2%, 20.0% ± 4.7% and 9.3% ± 4.6%; the percentages of trabecular bone area were 59.2% ± 6.8%, 40.1% ± 6.0%, 51.5% ± 5.6% and 63.2% ± 8.3%; and the microvascular densities were 14.3% ± 2.7%, 4.5% ± 2.1%, 10.2% ± 3.1% and 15.4% ± 4.1% in groups A, B, C and D respectively. There were statistically significant differences between group B and groups A, C, D (P lt;0.01). The fatty tamponade accumulated in the medullary cavity and intramedullary vascular sinusoids were pressed by the l ipocytes and became narrow. Limposomes were found in osteocytes and vascular endothel ia of group B and group C. Osteocytes of group B crimpled and pyknosis or karyolysis of chromatin were observed in these osteocytes, nuclearmembrane of the osteocytes was discontinous. Vascular endothel ia became swollen and the cell junctions widened or were destroyed in groups A and B. The incidence of osteonecrosis in group B (88.9%) was higher than that in group C (22.2%, P lt; 0.05). There was no osteonecrosis occurred in groups A and D . Conclusion Methylprednisolone combined with l ipopolysaccharide can induce typical rabbit model for early avascular necrosis of femoral head.
The change of Ig-forming cells in the gallbladder mucoderm were studied in the rabbit models.One hundred rabbits were randomly divided into the control group(Con,n=10),simple biliary obstruction group(BO,n=45)and biliary obstruction and infection group(BOI,n=45).The results showed that only a few Ig-forming cells presented in the gallbladder mucoderm of normal rabbit.At the 3rd,7th and 14th day,the quantities of IgG and IgA-forming cells in the mucoderm in BO group remained unchange,but increased much higher in BOI group(Plt;0.001),especially in IgG formation.This study suggests that the gallbladder of rabbit may be the important place of Ig-formation.The quantities of Ig-forming cells in bilitary tract may have a close relationship with the gallstone formation.