OBJECTIVE: To investigate the characteristics and the pathologic classification of electrical-injury nerve using somatosensory evoked potential(SEP) technique. METHODS: SEP were detected and evaluated in 12 cases with electrical-injury nerve during operation, electrical stimulation was commenced from distal side of nerve where the structure of nerve looks normal under operating microscope, up to proximal side until evoking out a stable SEP predeterminate virtual value. Pathological examination and the following functional evaluation were compared with the values of SEP. RESULTS: At the site of nerve looking normal under operating microscope, perineurium appears normal or slightly thicken. But there are obvious fibrosis and fibrotic proliferation between fascicular and intrafascicular. Vessel plexus is not seen. At SEP stabilizely evoked site, nervous construction is normal, there are visible interfascicular vessel plexus and connective tissue appears loose. Comparing SEP values with pathological section, amplitude and latency of SEP is positively correlative with the quality of nerve. Eight cases repaired with SEP technique to select the anastomosis site for nerve transplantation were followed up, two-point discrimination reached grade III (America hand surgery association criterion) within 62.5% cases. CONCLUSION: SEP technique is valuable method for functional evaluation of electrical- injury nerve which has a complicated pathology. The pathology of electrical-injury nerve can be classified into 4 types, type A: fibrosis of nerve; type B: nerve looking normal under operation microscope, perineurium appears thicken, and there are obvious fibrosis and fibrotic proliferation between fascicular and intrafascicular, vessel plexus is rarely to see; type C: nerve looks normal, lymphocyte infiltration exists and it is obvious that there are many physalis-like, retrogressive construction in the section; type D: nervous construction is normal, there are visible interfascicular vessel plexus, and connective tissue appears loose, SEP always can be stably evoked.
To find new technique for repair of peripheral nerve defect, the nerve elongation repair technique was adopted. Two cases with nerve defect were treated by this method. One was a 12 year old male, the defect length of right radial nerve was 7.2 cm at the elbow. The other one was a 28 year old male, the defect length of left ulnar nerve the was 5 cm at elbow. In this method, the nerve was elongated by slow stretch from distal and proximal end of the ruptured nerve. After a few days, the nerve was repaired by direct suture. After operation, the function of nerves were recovered in 119 days and 114 days respectively. Follow-up for 5 years, the function of the effected limbs were recovered to the normal side. It was concluded that: (1) the peripheral never can be elongated by slow stretch; (2) to stretch the nerve end in a rubber tube can prevent adhesion and connective tissue blocking; (3) strength and supporting point of stretching should be designed carefully.
OBJECTIVE: To explore the mechanism of tissue specificity of neurotropism in peripheral nerve regeneration, we investigated the biological characteristics of the nerve regeneration conditioned fluids(NRCF) on motoneuron of SD rats cultured in vitro. METHODS: Silicon chambers were sutured respectively to the distal stumps of motorial branch of femoral nerve and saphenous nerve to collect NRCF, namely MD-NRCF and SD-NRCF. The rats cortex motoneuron were divided into 4 groups and cocultured with MD-NRCF, SD-NRCF, b-FGF and serum-free medium respectively. The cultured cells were photoed under phase-contrast microscope, their longest neurites and cell-body areas were measured by cell image processing computer system. MTT automated colorimetric microassay was also adopted to quantify the activation of cultured motoneurons in each group. RESULTS: Cells of MD-NRCF group had longer neurites than those of the other three groups, and their activation was also superior to those of the other groups. CONCLUSION: The results suggest that MD-NRCF has more significantly neurite-promoting and neurobiological effects on motoneuron than SD-NRCF and b-FGF.
Objective Targeted adenoviral gene delivery from peripheral nerves was used to integrally analyse the characterization and time course of LacZ gene (AdLacZ) retrograde transfer to spinal cord and transgene product anterograde labeling ofperipheral nerve. Methods Recombinant replication-defective adenovirus containing AdLacZ was administrated to the cut proximal stumps of median and tibial nerves in Wister rats. Then the transected nerve was repaired with 10-0 nylon sutures. At different time point postinfection the spinal cords of C5 to T1 attached with DRGs and brachial plexuses, or L2 to L6 attached with DRGs and lumbosacralplexuses were removed. The removed spinal cord and DRGs were cut into 50 μm serialcoronal sections and processed for X-gal staining and immunohistochemical staining. The whole specimens of brachial or lumbosacral plexuses attaching with theirperipheral nerves were processed for X-gal staining. The number of X-gal stained neurons was counted and the initial detected time of retrograde labeling, peaktime and persisting period of gene expression in DRG sensory neurons, spinal cord motor neurons and peripheral nerves were studied. Results The gene transfer was specifically targeted to the particular segments of spinal cord andDRGs, and transgene expression was strictly unilaterally corresponding to the infected nerves. Within the same nerve models, the initial detected time of gene expression was earliest in DRG neurons, then in the motor neurons and latest in peripheral nerves. The persisting duration of β-gal staining was shortest in motor neurons, then in sensory neurons and longest in peripheral nerves. The initial detected time of β-gal staining in median nerve models was earlier in mediannerve models compared with that in the tibial nerve models. Although the initial detected time and the beginning of peak duration of β-gal staining were not same, the decreasing time of β-gal staining in motor and sensory neurons of thetwo nerve models were started at about the same day 8 post-infection. The labeled neurons were more in tibial nerve-models than that in median nerve models. Within the same models, the labeled sensory neurons of DRGs were morethan labeled motor neurons of ventral horn. The β-gal staining was tenser in median nerves than that in tibial nerves. However the persisting time of β-gal staining was longer in tibial nerve models. Conclusion The b gene expression in neurons and PNS renders this system particularly attractive for neuroanatomical tracing studies. Furthermore this gene delivery method allowing specific targeting of motor and sensory neurons without damaging the spinal cord might offer potentialities for the gene therapy of peripheral nerve injury.
The peripheral nerve group of the reparative and reconstructive surgery committee (branch of Chinese association of rehabilitation medicine) was established in 1995. Major research progress has been made in the repair, regeneration, and reconstruction of peripheral nerve injury. Professor GU Yudong initiated the contralateral cervical7 root (CC7) transfer for the treatment of total brachial plexus root injury in 1986. Now this method has been applied safely and effectively for 30 years with profound progress and refinement. In addition, the repair and reconstruction of peripheral nerve injury had achieved great development such as the treatment of spastic paralysis of upper limb, CC7 transfer using a modified prespinal route, the reconstruction of bladder function after spinal cord injury, the development of acellular allograft nerve, the small gap suture technique, the functioning free gracilis muscle transplantation, and contralateral S1 transfer which have been widely used in clinical application with good outcomes. With the progress of the biological manufacturing of peripheral nerve bio-materials and the remodeling of central nervous system after brachial plexus injury, a novel peripheral neuroscience research field was growing up. It is still a challenge for surgeons and scholars in this field to insist on the popularization and improvement of peripheral nerve repair and reconstruction by microsurgical technique, and to make efforts to transform the results of peripheral nerve research into clinical practice.
Objective To explore the facilitative effects of different allogenic cells injected into the denervated muscles on the nerve regeneration, the protection of the myoceptor degeneration, and the promotion for rehabilitation of the muscular function. Methods Schwann cells, myoblast cells, and renal endothelial cells were prepared from 400 SD rats aged 7 days and weighing 20.0±2.3 g. Thirty-six adult female SD rats weighing 120-150 g were randomly divided into 4 groups(n=9). Under the asepsis condition, the left ischiadic nerves of all the SD rats were cut off, and the primary suture of the epineurium was performed. After operation, the different corresponding cells were injected into the triceps muscles of the rat calf in each group once per week for 4 times in all. One ml of Schwann cells (1×106/ml) was injected into the rats in Group A; 1 ml of the mixed cells of Schwann cells and myoblast cells (1×106/ml) was injected into the rats in Group B; 1 ml of the extract from the mixed cells of Schwann cells, myoblast cells, and renal endothelial cells (1×106/ml) was injected into the rats in Group C; 1 ml of the culture medium without any serum was injected into the rats in Group D as a control. After operation, observation was made for the general condition of the rats; 3 months after operation, enzymohistochemistry and the CJun expression were performedin the ventricornual motor neuron. At the proximal and the distal ends of the nerve suture, the density of neurilemma cells in the unit area and the area size of the regenerated nerve fibers were observed and measured. Results The affected limbs of the rats in Groups A, B and C improved 13 months after operation. The ulcers and swelling at the ankles gradually relieved and the rats could move normally 3 months after operation. However, the affected limbsof the rats in Group D still had ulcers and swelling, with an obvious contracture of the toes and a difficult movement. Three months after operation, the number of the target muscle myoceptor, the number of the Actin positive cells, the activity of the various enzymes in the denervated muscles, and the histological changes of the regenerated nerves were better in Group C than in Groups A and B (P＜0.01); and they were all better in Groups A, B and C than in Group D（Plt;0.01）. Conclusion Schwann cells, the mixture of Schwann cells and myoblast cells, and the extract from the mixture of Schwann cells, myoblast cells and renal endothelial cells can all promote neurotization and rehabilitation of the muscular function, and protect against the myoceptor degeneration. However, the effect of the extract is superior to that of Schwann cells or the mixed cells.
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.
A 0.6cm segment of right common peroneal nerve was resected in 60 SpragueDawley rats. The nerve defects were bridged by adhering the epineurium with autogenous nerve, vein, skeletal muscle, tendon and silastic tube. According to the kinds of the grafts used, the rats were divided into 5 groups. In 6 and 12 weeks after operation, the effect was assessed by motor nerve conduction velocity, weight of the anterior tibial muscle, number of distal axons and histological examination. It was demonstrated that the result from autogenous nerve graft was superior to other grafts in all aspects and that of the vein graft was better thanthe other three. The characteristics of the nerve regeneration and the process of maturation in different types of the grafts were discussed. The related microenvironment which caused the difference was also discussed.
Forty white rats, randomly equally divided into experimental and control groups, were used in this study. Sodium amytal was injected intraperitoneally, a crushing injury of the sciatic nerve was created in all of the 80 rats. The forty rats in the experimental group were treated with hyperbaric oxygenation while those rats in the control group received no treatement. From 2-8 weeks following the crushing injury of the sciatic nerves, it was observed that the treatment group showed an earlier recovery of nerve function and carlier response of leg muscles to electristimulation; less edema and exudation; marked proliferation of Schwann’s cells and more rapid recoveryof neurilemma, lastly. the number and rate of regeneration of neural axons were higher than that the control group.