Ten, fifteen and twenty millimeter nerve defects were produced on both trunks of sciatic nerve in 18 rabbits. The stumps of the nerve were enclosed by a silicon tube in the right hind limb (slilcon group) and the left limbs were free (free group). The proximal and distal nerve stumps in both groups were elongated by using a selfdesigned nerve stretching device, and the nerve were gradually stretched by 1mm, 2mm and 3mm per day respectively. when the expected lengths were achieved, the defects of the nerve were managed by endtoend coaptation. The samples were analysed by electrophysiological examination, and light and electron microscopes. Results were as follows: (1) The nerve defect could be repaired by gradual elongation in rabbits; (2) The results of silicon group were superior to the free group; (3) The structure and microcirculation of the nerve would be damaged if the stretching speed exceeded the limit of 2mm per day. But the eventual results following repair by elongation could not reached the normal level.
Motor endplate is the structure connected between the nerve terminal and muscle fibre and plays a very important role in conducting nerve impulses to the target, therefore, systemical study of the sequential changes of the motor end-plate upon denervation is quite important.Ninety New Zealand rabbits were divided into nine groups from two weeks to nine months after denervation. Acetycholinesterase(AchE) was analyzed quantitatively to study the sequential changes of the motorendplates of tibialis anterior muscle. The results showed that there was no significant reduction of AchE at theend if one month after denervation, whereas a sharp reduction of AchE afterwards. AchE could not be stained after five month denervation.
Thiry wistar rats were used and divided in 2 groups. A segment of 6mm was excised in the sciatic nerve which were then bridged with chitin and skelal muscle. at 4,8,12 weeks after operation, In the chitin group a satisfactory regeneration of nerve fibers was evident with electrophysiologic and histologic examinations, and HRP retrogade labelling evaluation. The possible mechanism of enhancing nerve regeneration of chitin was also discussed.
In order to improve the therapeutic effect of non-neural tissue in bridging the peripheral nerve defect and increase the blood supply of the implant, the silicone tube was chosen to bridge the gap, and the vessel bundle was inserted into the tube. The procedures were performed as following: resected the pseudoneuroma and enveloped the proximal and the distal ends in a silicone tube, and then sutured the epineurium and the tube wall with 7/0 stitch. In patients, eleven cases with fifteen nerves were treated, including seven median nerves, five ulnar nerves and three radial nerves. The lengths of the nerve defects were within 3 cm in 13 nerves and 3 cm-5 cm in 2 nerves. They were followed up from one to five years and the result was excellent (M4S4) in 8 nerves, good (M3S3) in 3 and poor (M1S1) in 2. It was discussed that the indication for the procedure should be included: the nerve defect could not be sutured directly, and the patient would not agree to use his own nerve for graft.
Objective To comment on the recent advances of production and application of the bio-derived scaffold in the tissue engineered peripheral nerve. Methods The recent articles were systematically analyzed, and then the production methods of the bio-derived scaffold and its application to the tissue engineered peripheral nerve were evaluated and prospected. Results B iological tissues were processed by some methods to produce the bio-derived materials. These mat erials could maintain the structure and components of the tissues. Moreover, the immunogenicity of these materials was reduced. Conclusion Application of the bio-derived materials is a trend in the fabricating scaffold of the tissue en gineered peripheral nerve.
OBJECTIVE: To investigate the effect of olfactory ensheathing cells (OECs) on functional recovery after sciatic nerve injury. METHODS: Upon silicone-tubulization of transected sciatic nerve in 30 adult rats. Thirty rats were divided into two groups(SAL group and OECs group); saline and OECs were injected into the silicone chamber in SAL group and in OECs group respectively. The status of functional recovery of injured sciatic nerve was observed by electrophysiological analysis, axon morphometry analysis. RESULTS: In OECs group on the 30th and the 90th days after sciatic nerve transection: 1. The latent period of CMAP shortened by 0.60 ms and 0.56 ms; the nerve conduction velocity promoted by 6.42 m/s and 5.36 m/s; the amplitude enhanced by 3.92 mv and 5.84 mv, respectively; 2. The HRP positive cells in lateral nucleus of spinal anterior horn increased by 11.63% and 25.01%; 3. The number of nerve fibers increased by 1,047/mm2 and 1,422/mm2 and the thickness of myelim sheath increased by 0.43 micron and 0.63 micron, respectively. CONCLUSION: The olfactory ensheathing cells are capable of promoting the functional recovery after peripheral nerve injury.
In order to observe the collateral sprouting capacity of the nerve trunk after end-to-side anastomosis, a window was made on the epineurim of the donor nerve through which the result of the end-to-end anastomosis of nerves could be compared. Sixteen SD rats were chosen and divided into 4 groups randomly. Group 1, the peroneal nerve was severed, the epineurium of the tibial nerve was fenestrated and sutured the peroneal stump with the tibial nerve by end-to-side neurorrhaphy. Group 2, operative procedures were almost the same as that of Group 1, but no fenestration on the epineurium was done. Group 3, the distal peroneal nerve stump was sutured in paralell with the tibial nerve without fenestration on the tibial nerve and Group 4, severed the peroneal nerve and sutured the stumps by end-to-end anastomosis immediately. The peroneal function index(PFI) and acetylcholine transferase (ChAT) activity were assessed and the histological examination was performed in all rats. The results showed: between group 1 and 2, there was no difference in PFI and ChAT activity (P gt; 0.05). The existence of collateral sprouting in all groups was proved by histological examination. Even in Group 3, there were plenty of nerve fibers turned into tiny myelined nerve fibers through collateral sprouting. But the ChAT activity in Group 1 was only two thirds of that in Group 4. It was suggested that the epineurial sheath did not influence the collateral sprouting of the nerve.
Objective To study biological effect of transforming growth factor β(TGF-β) and recombinant human bone morphogenetic protein 2 (rhBMP-2) on theSchwann cell(SC) in vitro. Methods Cultured SC from newbornSDrats were implanted at 5×103/well in 96-well-plate (36 wells in each group, altogether 3 groups):TGF-β group (group A) treated with 50 ng/ml TGF-β; rhBMP-2 group (group B) treated with 50 ng/ml rhBMP-2 and control group (group C). SC proliferation activity was assessed by MTT and flow cytometry (FCM) methods, and nerve growth factor (NGF) synthesis in SC culture media was detected by ELISA method. Results MTT observation indicated that there was significant difference in the growth curve among 3 groups until the 8th and 9th day. Group A had more obvious rising tendency than group B and group C. FCM observation indicated that the proliferation index of group A and group B was higher than that of group C（Plt;0.05）. ELISA observation indicated that there was significant difference in the NGF concentration of the culture medium among the 3 groups(P＜0.05). Group A had the highest NGF concentration. Conclusion Exogenous TGF-β and rhBMP-2 can promote SC’s ability to proliferate NGF, but TGF-β is more effective than rhBMP-2.
OBJECTIVE: To study the effects of Schwann cell cytoplasmic derived neurotrophic proteins (SDNF) on the regeneration of peripheral nerve in vivo. METHODS: Ninety adult SD rats were chosen as the experimental model of degenerated muscle graft with vascular implantation bridging the 10 mm length of right sciatic nerve. They were divided randomly into three groups, 30 SD rats in each groups. 25 microliters of 26 ku SDNF (50 micrograms/ml, group A), 58 ku SDNF (50 micrograms/ml, group B) and normal saline(group C) were injected respectively into the proximal, middle and distal part of the degenerated muscle grafts at operation, 7 and 14 days postoperatively. The motorial function recovery assessment was carried out every 15 days with the sciatic nerve function index(SFI) after 15 days to 6 months of operation. Histological and electrophysiological examination of regenerating nerve were made at 1, 3 and 6 months postoperatively. RESULTS: There were significant statistic differences between the both of experimental groups(group A and B) and control group(group C) in the respects of the histological, electrophysiological examination and SFI(P lt; 0.01). CONCLUSION: The 26 ku SDNF and 58 ku SNDF can improve the regeneration of the injured peripheral nerve in vivo.
ObjectiveTo summarize the research progress of autologous vein nerve conduit for the repair of peripheral nerve defect. MethodsThe recent domestic and foreign literature concerning autologous vein nerve conduit for repair of peripheral nerve defect was analyzed and summarized. ResultsA large number of basic researches and clinical applications show that the effect of autologous venous nerve conduit is close to that of autologous nerve transplantation in repairing short nerve defect, especially the compound nerve conduit has a variety of autologous nerve tissue, cells, and growth factors, etc. ConclusionAutologous vein nerve conduit for repair of non-nerve defect can be a good supplement of autologous nerve graft, improvement of autologous venous catheter to repair peripheral nerve defect is the research direction in the future.