Objective To probe the possibility of functional sensory endings regeneration after end to side neurorrhaphy Methods Fifteen New Zealand rabbits were used in this study The left greater auricular nerve served as the donor nerve A nerve graft taken from the right ear served as the receptive nerve which anastomosed to the donor nerve with the other end implanting into the denervated skin flap Normal skin and denervated skin flap without nerve implantation served as control groups 5 animals in each group The single nerve fibre recording technique was used to investigate the number,distribution and types of regenerated discharging nerve fibers 4 months after operation Results The inductive discharges of nerve fibres wave observed in all types of regenerated sensory nerves,the total discharging fibers was about 58% of that in normal skin Few discharging fibers were observed in denervated skin flap without nerve implantation Conclusion End to ide neurorrhaphy can regenerate functional axons

ObjectiveTo probe the possibility of functional sensory endings regeneration after end-to-side neurorrhaphy. MethodsFifteen New Zealand rabbits were used in this study. The left greater auricular nerve served as the donor nerve. A nerve graft taken from the right ear served as the receptive nerve which anastomosed to the donor nerve with the other end implanting into the denervated skin flap. Normal skin and denervated skin flap without nerve implantation served as control groups 5 animals in each group. The single nerve fibre recording technique was used to investigate the number,distribution and types of regenerated discharging nerve fibers 4 months after operation. ResultsThe inductive discharges of nerve fibres wave observed in all types of regenerated sensory nerves ,the total discharging fibers was about 58% of that in normal skin. Few discharging fibers were observed in denervated skin flap without nerve implantation. Conclusion End-to-ide neurorrhaphy can regenerate functional axons.

Objective To evaluate the long term effect of acellular allogeneic nerve grafting combined with exogenous basic fibroblast growth factor (bFGF) in peripheral nerve repair. Methods Sixteen big-ear Japanese rabbits were divided into experimental and control groups randomly. In the experimental group, 3 cm-long acellular allogeneic nerves from New Zealand rabbit were used to bridge the rabbit tibial nerve defects; and 1 ml bFGF solution was given from the second day once daily for 2 weeks and twice a week for another 6 weeks after surgery. In the control group, normal saline solution was given. Morphological and functional results were evaluated 20 weeks after the nerve repair. Results The recovery rates of the evoked potential and the nerve conduction velocity in the experimental group were 67.59%?29.63% and 59.79%?21.11%, respectively, significantly higher than that (49.07%? 15.74% and 36.85%?18.69% respectively) in the control group (P

Objective To observe the effect of vacuum-assisted drainage (VAC) technique on the granulation tissue formation of infected soft tissue explosive injury in pig. Methods 16 wounds produced by explosion with electric detonators,which were fixed on the skin of the shoulders and hips of 4 small white pigs. The wounds were divided into 2 groups randomly: in group A the wounds were treated with conventional method,and in group B the wounds were treated with VAC set with a pressure of -15kPa. All wounds were infected on the third day after explosion. The depth of wounds was measured,and specimens were talcen from wound bed,immediately before treatment,and 1,3,6,9,14,19,and 24 days after treatment. The specimens were bistopathologieally studied with HE staining to assess the wound healing process of the two groups. Furthermore,immunohistochemistry for Factor Ⅷ related antigen and Ki67 was done to estimate the number of vascular endothelial cells and proliferating cells. Results From 1 to 19 days after the treatment,the depth of the wounds in group B were shallower than those of group A ( P

Objective To evaluate the promoting effect by bFGF on nerve regeneration following acellular allogeneic nerve grafting,and the effects of various concentration of bFGF on axon growth. Methods The animals were divided into 1 000U/ml, 500U/ml, 250U/ml,100U/ml and normal saline groups. Immunohistochemistry staining of neurofilament-160 and S-100 was used to show the length of axonal growth and Schwann cell infiltration 10 days after the surgery. Results The average distance of regenerated nerve fibers in the high dose groups (1 000U/ml and 500U/ml) was longer than that in the normal saline control group;but there was no difference between the low dose groups (250U/ml and 100U/ml) and the control group. Conclusion Early use of bFGF when acellular allogeneic nerve grafted to bridge peripheral nerve defect may obviously promote axon growth speed.

Objective To evaluate the biocompatibility of four kinds of polyurethane sponges made in China. Methods According to ASTM Standards for Medical Devices of America, polyurethane sponges are used to perform such biological tests as cytotoxicity test, acute toxicity test, pyrogenic reactions test, stimulation test of conjunctiva and cornea, sensitization test. The data are analyzed and evaluated according to the criterion. Results Reaction scales of these polyurethane sponges in cytotoxicity are 0 or 1 level. No toxicity effects and pyrogenic reactions are observed in vivo test. No conjunctiva and cornea irritation reactions and no sensitization reactions are found. Conclusions The four kinds of polyurethane sponges have high biocompatibility and can become ideal dressings of Vacuum-Assisted Closure.

Objective To test the effect of negative pressure on the rate of skin donor site re-epithelialization in pig model.Methods Five pigs were selected for this study,and two split-thickness skin graft defects were harvested from the back of each animal.Half of the donor sites were treated with 120 mmHg negative pressure as the experimental group for 10 days and half were treated with vaseline gauze as the control.Changes in each wound were assessed every two days.Results The rate of re-epithelialization increased significantly.The donor sites healed after 4 to 6 days of negative pressure treatment, 2 to 4 days earlier than the control group.The level of inflammatory reaction occurring in wounds treated with negative pressure appeared less severe than that in wounds treated with vaseline gauze.Negative pressure could facilitate cell proliferation.The ratios of S,G2 and M phase increased significantly,and higher expression of PCNA was observed and detected in hair hollicle epithelium,regenerative basal cells and glandular epithelium on day 4 and 8 after negative pressure treatment.Conclusion Negative pressure could significantly increase the rate of skin donor site re-epithelialization

Objective To observe the granule tissue remodeling under neoepithelium in minitype pigs' full thickness dermal wounds and discuss the relation between the remodeling and possible ulcers or scars. Methods After the establishment of eight full-thickness dermal wound models with the diameter of 4 cm on the back of six minitype pigs, the specimens were collected from wound edge and wound center immediately, 3, 6, 9, 12, 15, 20, 25, 30 and 45 days, respectively after injury for HE staining, immunohistochemical staining and Van Gieson staining and then observed under light microscope to count the cell number, fibroblasts and vascular endothelial cells as well as evaluate the quantity and arrangement of collagens. Results The mean wound healing time was (29.3?1.8) days. After 9-25 days, the granule tissues in the wound center contained more cells, fibroblasts, collagen and vascular endothelial cells than those under neoepithelium of wound edge (P 0.01). Meanwhile, the collagen quantity and arrangement style of granule tissues under neoepithelium during wounds healing (12-30 days) assembled those under neoepithelium 15 days after wound healing. Conclusion Granule tissue remodeling exists during the healing of full thickness dermal wound.

Objective To evaluate the biocompatibility of ZSM-5 zeolite and provide an experimental basis for developing the first-aid hemostatic agent.Methods According to Chinese evaluation standards on medical devices and biological tests,the cytotoxicity in vitro,hemolysis test,acute toxicity of system,pyrogen test,intracutaneous stimulation,sensitization and micronucleus test were studied in ZSM-5 zeolite.In order to find out the side-effect of the zeolite granules' remains left in the wounds to body,muscle implantation test was studied.Results There were no obvious cytotoxity,hemolysis reaction.Acute tocicity,pyrogen reaction,intraeutaneous stimulation,sensitization and potential mutagenesis in themicronucleus test were observed.Their results were a11 consistent with the Chinese biological evaluation of medical devices.Obvious inflammatory reaction was observed when ZSM-5 zeolite was implanted in muscle for 12 weeks.Conclusion The ZSM-5 zeo1ite has reliable biocompatibility.But zeolite can cause inflammatory reaction when it is remained in the wound surface for long term.

ObjectiveTo investigate the effect of microencapsules cells transfected with nerve growth factor (NGF) gene to the sciatic nerve regeneration following sciatic nerve injury in rats.MethodsMicroencapsules containing cells transfected with NGF gene were prepared using drop generative technique and cells were cultured in vitro. Animal model of sciatic nerve cut and sutured was established with Sprague-Dawely rats, and ninety-six animals were randomly divided into group A (in vivo implantation of microencapsules cells transfected with NGF gene), group B (in vivo implantation of microencapsule), group C (in vivo implantation of cells transfected with NGF gene), and group D (negative control group). The nerve conductive velocity (NCV), nerve action potential (NAP), sciatic nerve function index (SFI) were detected in the 4th, 8th and 12th week postimplantation.ResultsThe microencapsules cells transfected with NGF gene in microencapsules retained reliable cell viability and function. The expanded cells formed cell aggregates, with confocal laser scanning microscopy (CLSM), exhibited green fluorescence material in the cell. The NGF concentration in supernatant were arriving at 269 pg/ml when cultured for 10 days. The results of NCV, NAP and SFI tests in group A were higher than those in the other groups (P<0.05).ConclusionAfter implantation, microencapsules cells transfected with NGF gene may secrete NGF continuously in vivo, and has significant improvement effect on nerve regeneration following sciatic nerve injury.