Objective To explore effects of several immunosuppressants on cytokine expressions after repair for a sciatic nerve injury in a rat model. Methods The sciatic nerves of 42 rats were cut and suturedend to end. After operation, the rats were divided into 6 groups. Group A(n=9) was served as a control with no medicines given. Group B (n=9) was given methylprednisolone 20 mg/(kg·d) for 2 days. Groups C(n=9) and D(n=3) were given FK506 1 mg/(kg·d) for 2 weeks and 4 weeks respectively, and were given the same doses of methylprednisolone as Group B. Groups E and F were given CsA 2 mg/(kg·d) for 2 weeks and 4 weeks respectively, and were given the same doses of methylprednisolone as Group B. The sciaticnerves were sampled at 1, 2 and 4 weeks postoperatively. And immuneohistochemistry stainings of interleukin 1β(IL-1β)， tumor necrosis factor α(TNF-α), interferon γ(IFN-γ) and macrophage migration inhibitory factor(MIF) were performed. The staining results were compared and analyzed. Results The expression peaks of IL-1β and IFN-γ were found at the 1st week postoperatively in Group A. Then, the expression decreased rapidly at the 2nd week and disappeared at the 4th week. As for TNF-α and MIF, they were only found to have a low expression until the 1st week in Group A. In groups C-F, the expression peaks of IL-1β, TNF-α and IFN-γ were found at the 2nd week, while the expression peak of MIF was still at the 1st week, and the expression of all the cytokines extended to the 4th week. The expressions of these cytokines in Group B were just between the expression levels of Group A and Groups C-F. Conclusion Immunosuppressants can delay the expression peaks and significantly extend the expression time of IL-1β, TNF-α, IFN-γ and MIF after repair for a sciatic nerve injury in a rat model.
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.
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 Peri pheral nerve injury is a common cl inical disease, to study the effects of the physical therapy on the regeneration of the injured sciatic nerve, and provide a reference for cl inical treatment. Methods Sixty-four female adult Wistar rats (weighing 252-365 g) were chosen and randomly divided into 4 groups (n=16): group A, group B, groupC, and group D. The experimental model of sciatic nerve defect was establ ished by crushing the right sciatic nerve in groups B, C, and D; group A served as the control group without crushing. At 2 days after injury, no treatment was given in group B, electrical stimulation in group C, and combined physical therapies (decimeter and infrared ray) in group D. At 0, 7, 14, and 30 days after treatment, the sciatic nerve function index (SFI) and the motor nerve conduction velocity (MNCV) were measured, and morphological and transmission electron microscopy (TEM) examinations were done; at 30 days after treatment, the morphological evaluation analysis of axons was performed. Results At 0 and 7 days after treatment, the SFI values of groups B, C, and D were significantly higher than that of group A (P lt; 0.05); at 14 and 30 days after treatment, the SFI value of group D decreased significantly, no significant difference was observed between group D and group A (P gt; 0.05) at 30 days; whereas the SFI values of groups B and C decreased, showing significant difference when compared with the value of group A (P lt; 0.05). At 0, 7, and 14 days after treatment, the MNCV values of groups B, C, and D were significantly lower than that of group A (P lt; 0.05), and there were significantly differences between group B and groups C, D (P lt; 0.05); at 14 days, the MNCV value of group D was significantly higher than that of group C (P lt; 0.05); and at 30 days, the MNCV values of groups B and C were significantly lower than that of group A (P lt; 0.05), but there was no significant difference between group D and group A (P gt; 0.05). At 0 and 7 days, only collagen and l i pid were observed by TEM; at 14 and 30 days, many Schwann cells and perineurial cells in regeneration axon were observed in groups B, C, and D, especially in group D. Automated image analysis of axons showed that there was no significant difference in the number of myelinated nerve fibers, axon diameter, and myelin sheath thickness between group D and group A (P gt; 0.05), and the number of myelinated nerve fibers and axon diameter of group D were significantly higher than those of groups B and C (P lt; 0.05). Conclusion Physical therapy can improve the regeneration of the injured sciatic nerve of rats.
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.
ObjectiveTo review the research progress of peripheral nerve mismatch regeneration, and to provide reference for its related basic research and clinical treatment.MethodsThe pathophysiology of peripheral nerve after injury, several main factors affecting the mismatch regeneration of peripheral nerve, and the fate of axon after mismatch regeneration were summarized by referring to the relevant literature at home and abroad in recent years.ResultsDistal pathways and target organs can selectively affect the mismatch regeneration of peripheral nerves; different phenotypes of Schwann cells have different effects on the mismatch regeneration of peripheral nerves; studying the mechanism of action of exosomes from different Schwann cells on different types of axons can provide a new direction for solving the mismatch regeneration of peripheral nerves.ConclusionPeripheral nerve mismatch regeneration is affected by various factors. However, the specific mechanism and characteristics of these factors remain to be further studied.
OBJECTIVE: To explore the possibility to bridge peripheral nerve defects by xenogeneic acellular nerve basal lamina scaffolds. METHODS: Thirty SD rats were randomly divided into 5 groups; in each group, the left sciatic nerves were bridged respectively by predegenerated or fresh xenogeneic acellular nerve basal lamina scaffolds, autogenous nerve grafting, fresh xenogeneic nerve grafting or without bridging. Two kinds of acellular nerve basal lamina scaffolds, extracted by 3% Triton X-100 and 4% deoxycholate sodium from either fresh rabbit tibial nerves or predegenerated ones for 2 weeks, were transplanted to bridge 15 mm rat sciatic nerve gaps. Six months after the grafting, the recovery of function was evaluated by gait analysis, pinch test, morphological and morphometric analysis. RESULTS: The sciatic nerve function indexes (SFI) were -30.7% +/- 6.8% in rats treated with xenogeneic acellular nerve, -36.2% +/- 9.7% with xenogeneic predegenerated acellular nerve, and -33.9% +/- 11.3% with autograft respectively (P gt; 0.05). The number of regenerative myelinated axons, diameter of myelinated fibers and thickness of myelin sheath in acellular xenograft were satisfactory when compared with that in autograft. Regenerated microfascicles distributed in the center of degenerated and acellular nerve group. The regenerated nerve fibers had normal morphological and structural characters under transmission electron microscope. The number and diameter of myelinated fibers in degenerated accellular nerve group was similar to that of autograft group (P gt; 0.05). Whereas the thickness of myelin sheath in degenerated accellular nerve group was significantly less than that of autograft group (P lt; 0.05). CONCLUSION: The above results indicate that xenogeneic acellular nerve basal lamina scaffolds extracted by chemical procedure can be successfully used to repair nerve defects without any immunosuppressants.
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.
OBJECTIVE To investigate the effect of the emergent repair of peripheral nerve injury of the wrist. METHODS From July 1993 to December 1997, 17 cases were admitted, which 21 injured peripheral nerves were repaired emergently. Among them, there were 11 cases of median nerve injury, 2 cases of ulnar nerve injury and 4 cases of median and ulnar nerve injury. All the nerves were ruptured completely except one which was partially ruptured. The emergent operation was taken and the injured nerves were repaired by microsurgical technique. RESULTS Followed up 6 to 18 months after operation, 95.25% injured nerves had good outcome. CONCLUSION Because of the specific structure of the wrist, nerve injury at this part need to be repaired emergently. It can enhance the regeneration of the injured nerve, preserve the function of the intrinsic muscle of hand, and decrease the local adhesion.
To prove and improve the technique of fibrin glue adhesion repair peripheral nerve, 20 male rats were chosen. All the rats was randomly divided into two groups: Suture group (n = 10) and glue adhesion group (n = 10). Left sciatic nerves of the rats were cut with knife and repaired by suture or adhesion methods separately according to their groups. When adhesive method being used, the epineurial was fixed with a suture method similar to anchor suture for preventing suture line broken. Immediatly after the repair and 8 weeks after the surgery, the histologic and electrophysiologic changes of the repaired nerve were observed. The result showed: The axonal copation was soon improved in glue adhesion group. At the eighth week, nerve fiber alignment of the adhesion group was more regular than that of the suture group. Moreover, there were great improvement of axon cross rate and the recovery rate of sectional area of nerve fiber at the distal end in glue adhesion group (P lt; 0.05, P lt; 0.01). It was concluded that glue adhesion was prior to suture in repair of peripheral nerve, and anchor suture could improve the technique of glue adhesion method.