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BACKGROUND:The construction of tissue engineered skin needs a long time and high price, and the repair effects are poor. Moreover, the problems such as antigen elimination and disease propagation are not thoroughly solved. How to solve the tough problem of wound surface repair in patients lacking of autologous skin using current mature technology before the occurrence of ideal tissue engineered skin. OBJECTIVE:To investigate the effects of autologous composite skin constructed around expanders on the repair of the wound surface. METHODS:A total of 10 rabbits were selected. Two globular silica gel expanders were embedded subcutaneously in the symmetrical sites on the back of rabbits. After the expanders were covered by fiber kystis, cellsuspension of primary cultured skin epithelial cells (experimental group) or physiological saline (control group) were infused into lacuna between the expander. Four weeks later, the expanders were obtained. Experimental group presented epithelization, i.e., autologous composite skin. The skin and some fiber members on the top of the expanders were resected around the encystations. The fiber kystis on the bottom and surrounding the expanders was left to form the wound surface covered by autologous composite skin. However, the wound surface was covered by non-epithelization fiber kystis in the control group. The healing of wound surface was observed until recovered. RESULTS AND CONCLUSION:In the experimental group, the wound surface was ruddy and pure, with less secretion;the average healing time was (14.0±0.4) days;the microscopic appearance indicated that epithelial layer was thick and regular. In the control group, there was more secretion on wound surface;the average healing time was (27.0±0.7) days;the microscopic appearance indicated that epithelial layer was thin and irregular. These results suggested that the construction of autologous composite skin around the expanders could noticeably promote the healing of wound surface.
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Objective To observe the effects of autologous myoblast transplantation on endplate regeneration and neuromuscular function restoration following direct nerve implantation (DNI) in rats so as to offer experimental basis for the use of myoblasts in neural regeneration area and further lay foundation for the research using myoblasts as transgenic carriers. Methods A total of 20 male SD rats were randomly divided into experimental group and control group,with 10 rats in each group.Models of DNI in rat gastrocnemius were established.The experimental group was injected with primarily cultured autologous myoblasts to the DNI location,while the control group was injected with isometric medium without autologous myoblasts.The effects of myoblasts on the neuromuscular function recovery following DNI were studied by detecting the tibial functional index (FTI),neuro-electrophysiology and pathohistology.Results The experimental group displayed faster tibial nerve function recovery than the control group (P ＜ 0.01 ).The peak to peak value (PPV) of gastrocnemius neuro-electrophysiology,area under the curve and regenerated endplate number of the experimental group had statistical significances as compared with the control group ( P ＜ 0.01 ). Conclusion Myoblast autotransplantation accelerates the recoveryof neuromuscular function after rat DNI and increases the number of the regenerated endplates.
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Objective To explore a safe and high efficiency way of gene transfection of autocrine motility factor(AMF) in order to provide experimental basis for transplantation of myoblasts carrying AMF gone. Methods Sprague Dawley rat myoblasts were cultured, purified, proliferated and immunohisto-chemically verified. Then, the myoblasts were transfected with AMF and eGFP (enhanced green fluores-cent protein) gene by FIV (feline immunodeficiency virus). Fluorescence microscope and laser scanning confocal microscope were employed to detect eGFP so as to verify positive transfection rate. Expression of AMF was detected by immunohistochemical method. Results Myoblasts with 98% purity could he ob-tained after two weeks of primary culture and purification. Positive transfection rate reached 90.4% when MOI (multiplicity of infection) was 100 (P <0.01). The transfected AMF gene could express normally. Conclusions Explant culture is a proper way in rat myoblast culture. Meanwhile, AMF gene can he effectively transfected into rat myoblast and well expressed via FIV.
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BACKGROUND: There have been reports about the cochlea injury after high-velocity projectile wounding. The effect on ultrastructure of cochlea after blast was still unclear.OBJECTIVE: To investigate ultrastructural changes of cochlea and cochlear nerve after maxillofacial blast wound.DESIGN:A randomized controlled observational trail with dogs as subjects.SETTING: Otolaryngeal Department and Maxillofacial Surgery Laboratory of the Third Military Medical University of Chinese PLA.MATERIALS: The study was conducted from August 1995 through July 1997. The animal model in maxillofacial blast wound was established in Animal Center of Xinqiao Hospital of the Third Military Medical University of Chinese PLA. Specimens were treated in Maxillofacial Laboratory and observed in Electron Microscope Laboratory. Totally 15 dogs of either sex (weighting 9. 5 - 13.5 kg, mean 11.3 kg ) were randomly divided into three groups with 5 in each group. Two groups served as trauma groups 1 and 2 and the other group as control.METHODS: The maxillary and mandibular regions of 10 dogs in trauma groups were wounded by model 8 cardboard-shelled detonators to establish animal model of maxillofacial blast wound. At the 1st and 6th hour after trauma the wounds were examined and specimens of cochlea and cochlear nerve were dissected out for electron microscopic observation to study the ultrastructural changes. The specimens in the control group were treated the same way as those in the trauma groups except for blast injury.RESULTS: After wounded, the cochlea and cochlear nerve in the early period manifested cilia disorder, edema of the nerve and mitochondrial degeneration. At the 6th hour after trauma there were extensive degeneration in cochlea and cochlear nerve, cilia fallen off hair cells and dissolution of the structures in nerve sheath.CONCLUSION: The ultrastructural changes of cochlea and cochlear nerve are severed as a result of maxillofacial blast wound, but in early period the injury is reversible. So it is very important that early cure should be emphasized in treatment.
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Objective To investigate the advantages of coronal incision in the repair of midface fracture. Methods The clinical data of 42 patients who applied coronal incision and other adjuvant incisions to repair midface fractures were retrospectively analysed. Results The coronal incision can provide excellent exposure and methods for camouflaging the incision in the hair, and brought less complications and functional impairment. Conclusion Coronal incision was an ideal approach in the repair of the midface fracture.
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<p><b>OBJECTIVE</b>To investigate the survival mechanisms of the reverse-flow flap.</p><p><b>METHODS</b>A skin flap measuring 8.0 cm x 2.5 cm based on the left deep circumflex iliac vessel (DCIV) was designed and elevated on the rat's dorsum with 4.0 cm of it's length crossing the midline. The flap was served as the reverse-flow flap model. The survival area, the dynamic microcirculation including flow direction, microvessel number, caliber, pressure and vasculature were assessed respectively at 6 hour, 24 hour, 48 hour, 72 hour, 7 day and 14 day after operation.</p><p><b>RESULTS</b>The average gradient of perfusion pressure was 0 kPa before operation and was 4.9 KPa postoperatively between the proximal and the distal site of the flap. By anastomosis of bilateral DCIV, the blood flow run in a reversed pattern in the region distal to the midline. No venous valves were observed. Distal congestion developed in 20% of the flaps within 72 h. After that, the number and caliber of venous anastomosis increased with pressure dropping in the midline region. The axial vessels extended its branches progressively along the dilated anastomotic rami. As a result, the vasculature of the flap became similar to that of the conventional axial flap by the 14th day. With these changes, flap congestion was alleviated gradually and subsided within 7 days. All the flaps survived completely.</p><p><b>CONCLUSIONS</b>Anastomosis connecting the two axial vessels is the circulation route of the reverse-flow flap. By the gradient pressure between the proximal and distal region, blood is driven reversely. Within 72 h, the distal part is susceptible to congestion. In this period, increasing number and caliber and decreasing pressure of anastomosis is important mechanism to support the circulation. After that, the new vasculature similar to the conventional axial flap provides the flap with reliable and permanent blood supply.</p>
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Animals , Female , Male , Rats , Microcirculation , Rats, Wistar , Surgical FlapsABSTRACT
Forty-five healthy male dogs were wounded with high or middle-velocity steel ball on the lower part of the face.and the findings were as follows:(1)Craniocerebral injuries concomitant with maxillofacial gunshot wounds were charcterized by brain contusion in the entry side of the temporal lobe and extradural hemorrhage in the entry side of the middle cranial fossa,and their highest incidence and severity were found in those cases with mandible fracture due to high-velocity missiles.(2)The larger the amount of the absorbed energy from the bullet,the higher the incidence and severity of the craniocerebral injury.(3)The incidence and severity of the craniocerebral injury were positively correlated to the value of vibrational acceleration measured on the pareital bones,which suggests that vibrational acceleration plays an important role in the precipitation of craniocerebral injury secondary to maxillofacial gunshot wounds.