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 evaluate the effect of WO-1 on repair of the bone defect in the New Zealand rabbit radius by an oral or local administration. Methods Bone defects were surgically created in the bilateral radii of 36 Zealand rabbits (1.6-2.0 kg), which were randomly divided into3 groups. In Group A, the defective areas were given WO-1 0.1 ml (50 mg/ml) by the local injections; in Group B, the rabbits were given WO-1 5 mg each day by the oral administration. Group C was used as a control group. Among each of the 3 groups, 4 rabbits were randomly selected and were sacrificed at 20, 30 and 60 days after operation, respectively. Then, the serological, X-ray and histological examinations were performed. Results The serum alkaline phosphatase and bone glaprotein levels were significantly higher at 20 and 30 days after operation in Groups A and B than in Group C, but significantly lower at 60 days after operation in Groups A and B than in Group C（Plt;0.01）. The X-ray and histological examinations at 20, 30 and 60 days after operation revealed that the callus formation and remodeling were earlier in Groups A and B thanin Group C, and the remodeling was earlier and better in Group A than in Group B. Conclusion WO-1 can promote the repair of the radial defect in a rabbit; however, further studies on the doseeffect relationship, administration time, and administration route are still needed.
To investigate the protective effect of propofol on ischemia/reperfusion induced spinal cord injury in rabbits and its influence on excitatory amino acid (EAA). Methods Sixty New Zealand white rabbits weighing 2.0-2.5 kg, half males and half females, were selected. The infrarenal circumaortic clamping model was used. And 6 mL/kg different fluids were continuously infused through a catheter into the aorta distal to the clamping site at a speed of 12 mL/(kg?h) during the 30 minutes ischemia period. According to the different infusing l iquids, the rabbits were randomized into 6 groups(n=10 per group): group A, normal sal ine; group B, 10% intral ipid; group C, propofol 30 mg/kg; group D, propofol 40 mg/kg; group E, propofol 50 mg/kg; group F, propofol 60 mg/kg. At 0, 6, 24, and 48 hours after reperfusion, neurologic outcomes were scored on a Tarlov scale system. At 48 hours after reperfusion, the number of normal neurons in the anterior spinal cord was counted, and concentration of EAA in the lumbar spinal cord was measured by high performance l iquid chromatography. Results The neuroethological score was better in groups C, D, E and F than that of groups A and B (P lt; 0.05), the score of group E was the highest (P lt; 0.05), and there was no significant difference between group A and group B (P gt; 0.05). The number of normal neurons in the anterior spinal cord of groups C, D, E and F was greater than that of groups A and B (P lt; 0.05), and group E was greater than groups C, D and F (P lt; 0.05). The concentration of EAA in groups A, B, C, D, E and F was greater than that of normal tissue, the group E was the lowest (P lt; 0.05), the groups A and B were the highest (P lt; 0.05), and there was no significant difference between group A and group B (P gt; 0.05). Concentrations of glutamate and aspartic acid were negatively correlated to normal neuron numbers in the anterior spinal cord and neuroethological scores 48 hours after reperfusion, and the corresponding correlation coefficient was — 0.613, — 0.536, — 0.874 and — 0.813, respectively (P lt; 0.01). Conclusion Propofol can significantly inhibit the accumulation of EAA in spinal cord and provide a protective effect against the ischemia/reperfusion injury induced spinal cord in rabbits.
In this paper,the changes of activities of enzymes relating toenergy metabolism in rabbit's retina during acute ocular hypertension were observed.The activities of succinate dehydrogenase and adenosine triphosphatase were foud to be reduced,while the activities of the lactatic dehydrognease and glucose-6-phosphatase increased.The results reveal the disturbance of metabolism of energy in retina undergone acute ocular hypertension,and suggest that this might be the underlying factors relating to the defects of the functions and structures of the retina.
（Chin J Ocul Fundus Dis,1993,9:141-144）
Objective Construction of viable tissue engineered bone is one of the most important research fields in the cl inical appl ication of bone tissue engineering, to investigate the function of nerve factors in bone tissue engineering by celldetection in vitro and construction of neurotization tissue engineered bone in vivo. Methods Fifty-four healthy New Zealandwhite rabbits, male or female, weighing 2-3 kg, were involved in this study. Bone marrow mesenchymal stem cells (BMSCs) from the bone marrow of white rabbits were cultured. The second passage of BMSCs were treated with sensory nerve or motor nerve homogenates, using the LG-DMEM complete medium as control. The prol iferation and osteogenic differentiation of the cells were observed and tested by the MTT assay, alkal ine phosphatase (ALP) stain, and collagen type I immunocytochemistry identification. The osteogenic induced BMSCs were inoculated in β tricalcium phosphate (β-TCP) biomaterial scaffold and cultured for 72 hours, then the β-TCP loaded with seed cells was implanted in the rabbit femur with 15 mm bone and periosteum defects. Fifty-four New Zealand white rabbits were randomly divided into three groups (n=18): sensory nerve bundle (group A) or motor nerve bundle (group B) were transplanted into the side groove of β-TCP scaffold, group C was used as a control without nerve bundle transplantation. X-ray detection was performed at the 4th, 8th, and 12th weeks after operation.
Objective?To investigate the osteogenesis effects of angiopoietin 1 (Ang-1) gene transfected bone marrow mesenchymal stem cells (BMSCs) seeded on β tricalcium phosphate (β-TCP) scaffolds (tissue engineered bone) with platelet-rich plasma (PRP).?Methods? BMSCs were isolated from bone marrow tissue of rabbits. The Ang-1 gene was transfected into the BMSCs at passage 2 by lentivector, which were seeded on β-TCP scaffolds with PRP (0.5 mL) after 48 hours of transfection. Bilateral radial segmental bone defects (15 mm in length) were created in 20 3-month-old New Zealand rabbits. Then the tissue engineered bone with the Ang-1 gene transfected BMSCs (experimental group) and untransfected BMSCs (control group) were implanted into the defects in the right and left radius, respectively. X-ray, histology, immunohistochemistry, and biomechanics observations were done at 2, 4, 8, and 12 weeks after operation.?Results?In vitro, the transfected rate was over 90% and RT-PCR showed that the Ang-1 expression were significantly increased after transfection. The X-ray films showed that some callus formed at 4 weeks, partial bony union was observed at 8 weeks, and complete union at 12 weeks in experimental group; and bone union was not observed at 12 weeks in control group. HE staining showed that capillary appeared at 8 weeks and more capillaries were observed in new bone at 12 weeks in experimental group; only a few capillaries were observed at 12 weeks in control group. At 8 and 12 weeks, the microvascular density were (50.1 ± 7.8) /mm2 and (66.1 ± 3.5) /mm2 in experimental group and were 0 and (30.3 ± 7.2)/mm2 in control group, showing significant differences between 2 groups at 12 weeks (Z= —2.107, P=0.031). Immunohistochemistry examination showed that the positive cells can be found at 8 weeks in experimental group. And the biomechanical analysis showed that maximum loads of experimental group were significantly higher than those of control group in three-point bending test and compression test at 12 weeks (P lt; 0.05).?Conclusion?The tissue engineered bone with PRP and Ang-1 can increase the osteogenic properties by enhancing capillary regeneration, thus it can be used to repair radial segmental bone defects of rabbit.
Objective To observe the effect of recombinant human osteoprotegerin (rhOPG) on osteoclasts which were stimulated by polyethylene particles and to investigate the feasibil ity of applying rhOPG for the prosthetic aseptic looseness. Methods The osteoclasts were isolated from the long bones of 5 New Zealand rabbits born within 24 hours, weighing 80-100 g, male or female, and were plated into the 24-well coversl ips (10 mm × 10 mm) and bone sl ices (8 mm × 8 mm × 50 μm) at the density of 1 × 105/mL. Based on the different concentration and density of rhOPG and polyethylene particles, the plates of culture were divided into 3 groups: the group with polyethylene particles of 1 × 109/mL (polyethylene group), the group co-cultured with polyethylene particles of 1 × 109/mL and rhOPG of 100 ng/mL (polyethylene/rhOPG group) and the control group . The glass cover sl ips and bone sl ices were exposed to HE, toluidine blue and tartrate-resistant acid phosphatase (TRAP) staining at 1, 3, 5 and 7 days, and TRAP positive multinucleated cells and bone resorption tips were counted. Scanning electron microscope was used to observe the pits of bone resorption. Results The osteoclast was rose-red when exposed to TRAP staining. For the number of the TRAP-positive osteoclasts, the polyethylene group witnessed an obviouse increase compared with the control group and the polyethylene/rhOPG group after 5 and 7 days of culture (P lt; 0.05). And no significant difference between the control group and the polyethylene/rhOPG group was evident (P gt; 0.05). The pits of bone resorption was blue-purple when exposed to toluidine blue staining. For the number of bone resorption pits in the bone sl ice, significant difference was evident between the polyethylene group and the control group after 5 and 7 days of culture (P lt; 0.05), and there was significant different between the polyethylene/rhOPG group and the polyethylene group 1, 3, 5 and 7 days after culture (P lt; 0.05). Conclusion rhOPG could inhibit the stimulated effect of polyethylene particles on osteoclasts, and might be used to prevent the prosthetic aseptic looseness after artificial joint substitution.
Objective To detect the cell density, apoptotic rate, and the expressions of BNIP3 in nucleus pulposus of degenerative intervertebral disc of rabbits, so as to further understand the mechanism of intervertebral disc degeneration. Methods Thirty male New Zealand white rabbits, aging 3 months and weighing (2.3 ± 0.2) kg, were divided into sham operation group (control group, n=10) and intervertebral disc degeneration model group (experimental group, n=20). Interbertebral disc degeneration models were establ ished by puncture of L3,4, L4,5, and L5,6 intervertebral discs in the experimental group; intervertebral discs were exposed only and then sutured in the control group. The degree of intervertebral disc degeneration was evaluated according to Pfirrmann classification by MRI at 4 and 8 weeks after establ ishing models. Apototic cells were determined by TUNEL and histological methods, and the immunohistochemical staining was performed to detect the expressions of BNIP3 in nucleus pulposus of intervertebral disc. Results MRI examination showed that the signal intensity decreased gradually at 4 and 8 weeks in the experimental group. There wassignificant difference in the degree of intervertebral disc degeneration between at 4 weeks and at 8 weeks in the experimental group (P lt; 0.05). The histological observation and TUNEL test showed that high density of nucleus pulposus cells and only a few apoptotic cells were observed in the control group; at 4 and 8 weeks, the density of nucleus pulposus cells decreased gradually with more apoptotic cells in the experimental group. There were significant differences in the nucleus pulposus cell density and positive rate of TUNEL staining between 2 groups, and between at 4 weeks and at 8 weeks in the experimental group (P lt; 0.05). The expression of BNIP3 of nucleus pulposus was negative in the control group; however, in the experimental group, the positive expression rates of BNIP3 of nucleus pulposus (the gray values) were 13.45% ± 1.16% and 32.00% ± 1.82% (194.32 ± 4.65 and 117.54 ± 2.11) at 4 and 8 weeks respectively, showing significant differences (P lt; 0.05). Conclusion The decrease of cell density in nucleus pulposus is involved in the development of intervertebral disc degeneration. Cell apoptosis is one of reasons in the decrease of nucleus pulposus cell; BNIP3 is involved in nucleus pulposus cell apoptosis in the degenerative intervertebral disc.
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 compare the effect between vascularization osteogenesis and membrane guided osteogenesis in the bone repair by the tissue engineered bone with pedicled fascial flap packing autologous red bone marrow (ARBM), so as to provide a reference for the bone defect repair in cl inic. Methods The tissue engineered bone was constructed with ARBM and the osteoinductive absorbing recombinant human materials with recombinant human bone morphogenetic protein 2. Sixty New Zealand rabbits (aged 4-5 months, weighing 2.0-2.5 kg) were randomly divided into group A (n=16), group B (n=22), and group C (n=22). The complete periosteum defect model of 1.5 cm in length was prepared in right ulnar bone, then the tissue engineered bone was implanted in the bone defect area in group A, the tissue engineered bonewith free fascial flap in group B, and the tissue engineered bone with pedicled fascial flap in group C. At 4, 8, 12, and 16 weeks, the tissue of bone defect area was harvested from 4 rabbits of each group for the general, histological, and immunohistochemical staining observations; at 8, 12, and 16 weeks, 2 rabbits of groups B and C, respectively were selected to perform ink perfusion experiment by axillary artery. Results The general observation showed that the periosteum-l ike tissues formed in the fascial flap of groups B and C, chondroid tissues formed in group B, new bone formed in group C, and the fibrous and connective tissues in group A at 4 and 8 weeks; a few porosis was seen in group A, more new bone in group B, and bone stump formation in group C at 12 and 16 weeks. Histological observation showed that there were few new blood vessels and new bone trabeculae in groups A and B, while there were large amounts of new blood vessels and mature bone trabeculae in group C at 4 and 8 weeks. There were a few new blood vessels and new bone trabeculae in group A; more blood vessels, significantly increased mature trabeculae, and the medullary cavity formation in group B; and gradually decreased blood vessels, the mature bone structure formation, and the re-opened medullary cavity in group C at 12 and 16 weeks. The immunohistochemical staining observation showed that the levels of CD105, CD34, and factor VIII were higher in group C than in groups A and B at different time points.The bone morphometry analysis showed that the trabecular volume increased gradually with time in 3 groups after operation; the trabecular volume in group C was significantly more than those in groups A and B at different time points (P lt; 0.05); and there was significant difference between groups A and B (P lt; 0.05) except the volume at 4 weeks (P gt; 0.05). The vascular image analysis showed that the vascular regenerative area ratio in group C was significantly higher than those in groups A and B at different time points (P lt; 0.05). The ink perfusion experiment showed that the osteogenic zone had sparse ink area with no obvious change in group B, while the osteogenic zone had more intensive ink area and reached the peak at 8 weeks, then decreased in group C. Conclusion The tissue engineered bone with pedicled fascial flap packing ARBM has the vascularization osteogenesis effect at early stage, but the effect disappears at late stage gradually when the membrane guided osteogenesis is main.
