Objective To study the mechanism of restenosis of the vein graft and the effect of the grafting injury to the vein graft. Methods One side of the 36 healthy rabbits was randomly chosen as the V-A group, and on the side a 1.5cmlong femoral vein was obtained, and an 0.5-cm-long segment of the obtained femoral vein was separated as the control group. The remaining 1-cm-long femoral vein was inverted and was autogenously implanted into the femoral artery on the same side of the rabbit. The other side of the rabbits was chosen as the V-V group, and on this side a 1-cm-long femoral vein was obtained ex vivo and then was sutured in situ. The vein grafts on both sides were harvested 4 weeks after operation. The specimens from the harvested vein grafts were stained with HE and theelastic fiber Victoria blue for an observation on the histological changes in the walls of the vein grafts, and the specimens were also stained by the immunohistochemistry of the proliferating cell nuclear antigen (PCNA) for an observation on the wall cell proliferation of the vein grafts. The changes in the ultrastructure of the proliferated wall cells of the vein grafts were observed under electron microscope. The two sides of the rabbits were compared. Results The smooth muscle cells of the media developed hyperplasia, but theintima and the media remained unchanged in their thickness (3.50±0.41 μm, 12.23±1.59 μm) in the V-V group, with no difference when compared with the control group (3.40±0.37 μm, 12.14±1.62 μm); however, when compared with the V-A group (25.60±3.21 μm, 21.30±2.47 μm),there was a significant difference in the thickness (Plt;0.01). There were no cells positive for PCNA by the immunohistochemistry examination in the control group. The cells positive for PCNA were found in the intima and the media in both the V-V group and the V-A group; however, the percentageof the cells positive for PCNA in the intima and the media was significantly greater in the V-A group than in the V-V group (16.4%±1.9% and 36.5%±3.7% vs 5.9%±1.3% and 23.4%±3.4%, Plt;0.01). In the V-V group, the endothelial cell could be observed under transmis-sion electron microscope, which was flat and had a processlike villus at its free end, and the endothelial cells were closely arranged andhad hyperplasia of the smooth muscle cells in the media. But in the V-A group,the endothelial cells had an obvious hyperplasia with an irregular shape and a widened space between the cells, and in the intima a great amount of the smooth muscle cells could be observed, which had a broken basement membrane. The smooth muscle cells also had an obvious hyperplasia in the media. The shape and alignment of the endothelial cells in the control group were similar to those in the V-V group, but the hyperplasia of the smooth muscle cells was not observed in the media. Conclusion The grafting injury can cause hyperplasia ofthe vascular wall cells, and if the hemodynamics is changed simultaneously, more serious hyperplasia and cell migration can be observed from the media to the intima, resultingin restenosis of the blood vessels. So, if we can reduce the grafting injury and improve the microcirculation of the vein graft, we may find out the methods ofpreventing restenosis of the vein graft. The animal model of the V-V graftcan help to understand the mechanism of restenosis of the vein graft.
Objective To compare the difference of preparing the acellular larynx scaffold between perfusion method and immersion method, and find better way to make acellular larynx scaffold for tissue engineering. Methods Twenty 6-month-old male New Zealand rabbits, weighing 2.0-2.5 kg, were divided into perfusion group (n=10) and immersion group (n=10) at random. All the larynxes were excised in a sterile fashion. The acellular larynx scaffold was obtained by perfusionmethod and immersion method respectively, and then comparative examinations were performed by the macroscopicview, histological view, scanning electron microscope (SEM), cartilage vital ity assay and toluidine blue staining. ResultsMacroscopic view showed that the larynxes perfused by sodium dodecyl sulphate (SDS) became transparent after 2 hoursof perfusion, but the larynxes immersed by SDS over 16 hours still appeared pink-white. Histology and SEM indicated thatcompared with immersion group, perfusion group showed better acellular effect, more ventages and collagen fibers wereretained, no intact cell or nuclei remained in acellular matrix and chondrocytes were still survival. The porosity was 85.39% ± 3.16% in perfusion group and 34.72% ± 4.51% in immersion group, showing significant difference (P lt; 0.01). The chondrocyte vital ity rate of perfusion group (86.93% ± 1.52%) was higher than that of immersion group (77.73% ± 1.66%), showing significant difference (P lt; 0.01). Toluidine blue staining showed that the chondrocyte heterochromaty was ber in perfusion group than that in immersion group. Conclusion Compared with immersion method, perfusion method is a better way to construct acellular larynx scaffold because it can achieve better acellular effect and retain chondrocyte vital ity at the greatest extent in the acellular larynx scaffold.
The comparison made between two experimental models with obstructive jaundice, which were newly established reversible model and traditional bile duct ligation and internal drainage model, showed that the new model was superior to the traditional one. This study suggests that the new model would be an ideal model, which could replace the traditional one for studying obstructive jaundice.
ObjectiveTo systematically review the efficacy of moxibustion in the treatment of model rabbits with knee osteoarthritis (KOA).MethodsCNKI, WanFang Data, VIP, CBM, PubMed, EMbase and The Cochrane Library databases were electronically searched to collect animal experiments on moxibustion in the treatment of model rabbits with KOA from inception to January 31st, 2019. Two reviewers independently screened literature, extracted data, and assessed the risk of bias of included studies. Meta-analysis was then performed by using RevMan 5.3 software.ResultsA total of 13 articles involving 226 model rabbits were included. The results of meta-analysis showed that moxibustion could reduce Mankin score (MD=?6.47, 95%CI ?7.63 to ?5.32, P<0.000 01), positive expression rate of chondrocyte apoptosis (MD=?22.21, 95%CI ?23.22 to ?21.21, P<0.000 01), level of IL-1β in joint fluid (SMD=?8.40, 95%CI ?15.09 to ?1.72, P=0.01), NO content in joint fluid (SMD=?11.03, 95%CI ?17.87 to ?4.19, P=0.002), the level of serum IL-1β (MD=?19.94, 95%CI ?23.61 to ?16.27, P<0.05), and serum NO content (MD=?22.69, 95%CI ?28.77 to ?16.61, P<0.05) of model rabbits with KOA.ConclusionsCurrent evidence shows that moxibustion can improve articular cartilage injury, strengthen chondrocyte activity, inhibit the inflammatory response, and inhibit chondrocyte apoptosis of model rabbits with KOA. Due to the limited quality and quantity of the included studies, more high-quality studies are required to verify the above conclusions.
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）
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）
In this experiment, two proximal ends of themedian and ulnar nerves of rabbit wereapproxirnated within the chitin tube for thepurpose to inhibit the neuroma formation. Byobservation under light and transmission electronmicrnscopo and immunohistochemistry, wefound that: (1) the axons of the two proximalstumpe could regenerate in the chitin tube for 2to 5mm, and then ceased to grow when anaxonal overlap happened resulting in inhibitingneuroma formation; (2) chitin tube could bedegradated a...
To explore the histological and the hematological change of rabbits after implanting novel injectable artificial nucleus prostheses, and to evaluate the biological safety. Methods In accordance with Biological Evaluation of Medical Devices, materials of polyurethane, sil icone rubber and macromolecular polyethylene for medical use were made into short column 1 cm in length and 0.3 cm in diameter. Forty-eight SPF New Zealand white rabbits weighing 2.5-3.0 kg were used, and cavity 1 cm in depth was made in the area 2 cm away from the spinal midl ine by separating muscle.Then according to different material being implanted, the rabbits were divided into 3 groups (n=16): Group A, polyurethane; group B, sil icone rubber; group C, macromolecular polyethylene for medical use as negative control. General condition of the rabbits was observed after operation. Gross and histology observation were conducted 1, 4, 12 and 26 weeks after operation. Blood routine, biochemical function and electrolyte assays were performed 26 weeks after operation to observe pathological changes of organs. Meanwhile, physicochemical properties of the materials were detected, and the material in the same batch was used as negative control. Results All rabbits survived until the end of experiment, and all wounds healed by first intention. In each group, red swollen muscles were observed 1 week after operation and disappeared 4 weeks after operation, connective tissue around the implanted materials occurred 12 and 26 weeks after operation. At 26 weeks after operation, there were no significant differences among three groups in blood routine, biochemical function and electrolyte assays (P gt; 0.05). Organs had smooth surface without ulceration, ecchymosis, obvious swell ing, hyperemia or bleeding, and nodules. There were no significant differences among three groups in percentage weight of each organ (P gt; 0.05). Histology observation: granulation tissue prol iferation and inflammatory cell infiltration were observed in each group 1 week after operation, fibrous capsule formation around the materials and the disappearance of inflammatory cell infiltration were evident 4 weeks after operation, cyst wall grewover time and achieved stabil ity 12 weeks after operation. The inflammatory response and the fiber cyst cavity of groups A and B met the standard of GB/T 16175 and were in l ine with group C. No specific pathological changes were discovered in the organs 26 weeks after operation. For group A, no significant difference was evident between before and after material implantation in terms of weight average molecular weight, number average molecular weight, tensile strength at break and elongation at break (P gt; 0.05). For group B, no significant difference was evident between before and after material implantation in shore hardness (P gt; 0.05). Conclusion Novel injectable nucleus pulposus prostheses do not damage local tissue and function of organs, but provide good biocompatibil ity and biological safety.
OBJECTIVE: To establish the animal models of mandibular distraction osteogenesis in rabbits and study its osteogenetic mechanism. METHODS: The right mandibles just anterior to the first molars of 12 rabbits were performed osteotomies, and the mandibles were positioned with distractors. The left mandibles were control group without operation. After 1 week, the distractors were stretched 0.9 mm every day for 10 days progressively. One day, 2, 4, 8 weeks after distraction, the mandibles were studied with gross measurement, X-ray, and histological examination. RESULTS: The right mandible were lengthened 8.3 mm on average without bone nonunion and deformity healing. It was observed that the gaps between the distracted bone edges were first occupied by fibrous tissue. Two weeks after distraction, it was found that the gaps were bridged by callus in X-ray, the new bone and the normal bone could not be differentiated clearly after 8 weeks. In histological sections, there were collagen bundles in early distraction, then those collagen bundles were calcificated and become trabeculaes. No Cartilage was found during distraction. CONCLUSION: It suggests that the rabbit mandible can be lengthened by distraction osteogenesis, and the new bone is formed by intramembranous ossification.
Objective
To study the effect of the human umbilical cord blood on the content of trace elements in whole blood during fracture healing in rabbits and to explore the mechanism of promoting fracture healing.
Methods
The right tibial fracture model was made in 63 white New Zealand rabbits (aged, 4-5 months; weighing, 2.0-2.5 kg). The fracture site was treated with 3 mL human umbilical cord blood (group A, n=21) and 3 mL normal saline (group B, n=21) at 3 and 8 days after operation, and was not treated as a control (group C, n=21). At 1, 2, 3, 4, 5, and 6 weeks after operation, the X-ray and histological observations were done; the contents of zinc, copper, magnesium, ferrum, calcium, and phosphorus were detected.
Results
X-ray observation showed that the fracture healing speed of group A was significantly faster than that of groups B and C; the fracture healing X-ray score of group A was significantly higher than that of groups B and C at 2-6 weeks (P lt; 0.05). The histological observation indicated that new trabeculae and osteoid of group A were significantly more than those of groups B and C; at 2-5 weeks, the histological score of group A was significantly higher than that of groups B and C (P lt; 0.05); at 6 weeks, the score of group A was significantly higher than that of group B (P lt; 0.05), but no significant difference was found between groups A and C (P gt; 0.05). Changes trend of the trace elements in 3 groups after operation was basically consistent. The content of copper first decreased and then gradually increased; the contents of ferrum, zinc, and magnesium at different time points decreased, but were basically stable; the content of calcium first increased and then decreased; the content of phosphorus first decreased and then increased. The contents of copper, zinc, magnesium, ferrum, calcium, and phosphorus in group A were significantly higher than those in groups B and C at different time points (P lt; 0.05), but there was no significant difference between groups B and C (P gt; 0.05).
Conclusion
Injection of the human umbilical cord blood at the fracture end of rabbits can significantly slow down the loss of trace elements in whole blood, ensure the contents of necessary trace elements during fracture healing, which may be one of the mechanisms of the umbilical cord blood promoting fracture healing.
