Abstract An animal experiment had been conducted for the purpose to find out the possibility of application of instantaneous sustained limited expansion (ISLE). A total of 54 skin defects in 9 pigs were obtained and were divided into two groups. One group of the pigs were subjected to instantaneous sustained limited expansion, the others, as the control group, just received the tension suture. At the same time the blood supply of the skin was measured by laser doppler flowmeter (LDF). It was showed that microcirculatory perfusion of the ISLE group was considerably better than that of the control. Inaddition, the correlation between the blood flow of the skin and the expanding pressure, as well as the pathologic changes of the skin were discussed.
In order to investigate the possibility of porous hydroxyapatite ceramics (HAC) in the repair of skull bone defect, twenty-four rabbits were used. The bone defect model was created by operation to obtain a defect in parietal bone in a size of 1 cm x 1 cm. Filled the defect with HAC and methyl-methacrylate-syrene copolymer (MMAS) to fill the defect as control. At 1st, 2nd and 3rd months after operation, behavior of the rabbits was observed and then these animals were sacrificed and specimens were examined under microscope. Results showed as follows: after operation, behavior of all animals were normal. By histological examination, it was found that in HAC group, there were granulation tissue, fibrous tissue and newly formed vessels grew into the pores and the osteoblasts formed osseous trabeculae. There was no inflammatory cell infiltration. In the MMAS grafted asea, there was formation of fibrous membrane. It suggested that HAC might be a good material for bone substitute in repair of skull bone defect.
The aim of this experiment was to study the osteogenesis in vivo of allogenic osteoblast combined culture with calcium phosphate composites. The osteoblasts were obtained by enzymatic digestion of periosteum from fibula subcultured to 13 generations, the cells were combined culture with hydroxyapatite and biphasic calcium phosphate. Subseguently, the composite was implanted into rabbits subcutaneously or intramuscularly. The blank material was implanted in the contralateral side as control. Four weeks later, all animals were sacrificed. All the implants were examined by gross observation, histological examination and EDXA. The results showed: 1. obvious ingrowth of connective tissue with very little inflammatory reaction; 2. new bone formation in the composites with deposit of Ca and P on the surface of osteoblast, but none in the blank materials; 3. no significant difference of new bone formation between the different sites of implantation or different materials, but those implanted intramuscularly had lamellae form of new bone while those implanted subcutaneously had only mineralization of extracellular matrix. The conclusion were: 1. the composites are biocompatible with prior osteogenesis property; 2. periosteal-derived allogenic osteoblasts obatined by enzymatic digestion could survive following implantation with bioactivity; 3. rich blood supply might be advantageous to new bone formation and its maturation.
Abstract A new kind of soft tissue expander with exteriorized injection valve was reported. Two types of expanders were designed: one with single cyst, single tube and single chamber, and the other with single cyst, single tube but double chambers, i.e, an additional drainage chamber. The drainage orifice could be controlled by a valve. An animal experiment had been conducted, and the outcome suggested that the new expander could provide rapid expansion of the soft tissue, sufficient drainage of the expanded area. The bacterial culture showed that among the 42 samples obtained from the expanded cyst, only 3 were positive. (2 of bacteria and 1 of fungus), suggesting comparatively low cyst infection.
A comperative study Of the thickness,the ratio of length to width and the division time of the pediele between the randomized defatted skin flap and the randomized conventional skin flap wasundertaken in 12 pigs,weighing 25-30 kg.Two tpe of defatted edicled skin flape were made,inwhich,one preserved a thickness of 2-3mm adipose tissue and the Other one third of the superficialfascial beneath the subeutaneous vascular network.The resuIts indicated that after division of thepedicles on the ...
To study the blood supply and revascularization of super thin skin flaps with a presserved subcutaneous vascular retwork , we carried out a randomized self-matched experimental study in 10pigs. The free skin grafts with a preserved subcutaneous vascular network served as control. All skingrafts and flaps were divided into 6 groupe, besed on the potoperative days (1st , 3rd, 5th , 7th , 10thand 14th day). The revascularization of flape were assessed by means of intravenous fluorescein test...
Application of the island flap on the back of rabbit as a model, the central vessel and its anterior edge vein was perserved. We explored the features of the blood supply and the difference in the dependence of the recipient bed of pure venous flap, arteriolised venous flap and conventional flap. The result showed that the conventional flap and arteriloized venous flap could survive, but the pure venous flap could not. It was suggested that the pure venous flap was in an impending necrotic condition, therefore,the blood circulation of recipient bed and the rate of revascularization between the recipient bed and the flap seemed to play an important role in the survival of the flap.
The experiment was earied out on the a boomen of the whiterats. The epigastric vein wasarterialized by means of anastomcois with the femoral artery, lateral thoracic vein was reserved as aefferent vessel. The changes of hemorheology were mesured after arterialization, and were comparedwith the changes in the normal A-V skin flaps. The levels of platelet, aggreation, blood viscosityand plasma fibrinogen in arterialized vein flape were signmeantly higher than that in A-V flaps. ASa r...
OBJECTIVE To investigate the effect of meniscus suture on meniscus healing which included healing time and healing pattern. METHODS Fourty healthy rabbits were adopted in this study. The model of meniscus injury was made by a longitudinal incision at the medial meniscus of the left knee. The rabbits were divided into two groups, the experimental group was treated by meniscus suture and the control group was unsutured. After operation, the meniscus samples were collected periodically and observed by gross, light and electronic microscope to analysis the meniscus healing. RESULTS The injured meniscus was healed gradually and completely at the sixth week in the experimental groups. More fibroblasts and less fibrocartilage cells could be observed in the healed meniscus. Oppositely, there was no meniscus healing in the control group and the edge of injured meniscus was sealed by epithelioid cells. CONCLUSION The meniscus suture can accelerate the healing process of meniscus injury. Besides, early suture make the injured meniscus correctly positioned to ensure the normal healing process.
Abstract In order to study the influence of chitosan on bone infection, 27 New-Zealand rabbits were randomly divided into 3 groups. According to the Norden technique, the model of osteomyelitis of the tuberosity of tibia was produced experimentally by injection of staphylococcus aureus.Immediately following injection of the staphylococci, the chitosan gel, acetic acid solution and sterile distilled water were injected into the bones in the 3 groups respectively. The latter two groups were served as control. The severity of the infection was evaluated by clinical symptoms and signs, radiographicdata as well as the bone culture and bacterial counts. Compared the results from chitosan with the other two controls, it was found that the local injection ofchitosan could not reduce the incidence of bone infection, however, it could provide actual improvement when other data were concerned. The effects of chitosangel might be attributed to its bacteriostatic and immunological activity as well as its slow degradation in the body.