Objective To review the advances of functional electrical stimulation(FES) in treatment of peripheral nerve injuries. Methods By index of recent literature, the measures of stimulation, the mechanisms of FES and unsolved problems were evaluated and analyzed. Results Great advances have been made in the treatment of peripheral nerve injuries. It can not only enhance the regeneration of injured peripheral nerve, but also prevent muscular atrophy. Conclusion FES is an effective treatment for peripheral nerve injuries.
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 Following the delayed repair of peripheral nerve injury, the cell number of anterior horn of the spinal cord and its ultrastructural changes, motorneuron and its electrophysiological changes were investigated. METHODS In 16 rabbits the common peroneal nerves of both sides being transected one year later were divided into four groups randomly: the degeneration group and regeneration of 1, 3 and 5 months groups. Another 4 rabbits were used for control. All transected common peroneal nerves underwent epineural suture except for the degeneration group the electrophysiological examination was carried out at 1, 3 and 5 months postoperatively. Retrograde labelling of the anterior horn cells was demonstrated and the cells were observed under light and electronmicroscope. RESULTS 1. The number of labelled anterior horn cell in the spinal cord was 45% of the normal population after denervation for one year (P lt; 0.01). The number of labelled cells increased steadily from 48% to 57% and 68% of normal values at 1, 3 and 5 months following delayed nerve repair (P lt; 0.01). 2. The ultrastructure of the anterior horn cells of the recover gradually after repair. 3. With the progress of regeneration the latency become shortened, the conduction velocity was increased, the amplitude of action potential was increased. CONCLUSION Following delayed repair of injury of peripheral nerve, the morphology of anterior horn cells of spinal cord and electrophysiological display all revealed evidence of regeneration, thus the late repair of injury of peripheral nerve was valid.
In order to verify the effectiveness of neural stump buried into the muscle in the prevention and treatment of neuroma, 17 cases were reported, in which 8 cases having 19 painful neuromas and 9 cases having 13 amputated meural stumps, buried into muscle. They wese followed up for 6 months to 40 months, It was shown that good and excellent results were obtained and no evidence of neuroma was observed in all cases except in one which had painful neuroma occurred from the failure of embedment of the neural stump into the muscle. The conclusion was that the neural stump buried into muscle was an effective method for the prevention and treatment of neuroma.
Objective To study the outcomes of nerve defect repair with the tissue engineered nerve, which is composed of the complex of SCs, 30% ECM gel, bFGF-PLGA sustained release microspheres, PLGA microfilaments and permeable poly (D, L-lacitic acid) (PDLLA) catheters. Methods SCs were cultured and purified from the sciatic nerves of 1-day-old neonatal SD rats. The 1st passage cells were compounded with bFGF-PLGA sustained release microspheres andECM gel, and then were injected into permeable PDLLA catheters with PLGA microfilaments inside. In this way, the tissueengineered nerve was constructed. Sixty SD rats were included. The model of 15-mm sciatic nerve defects was made, and then the rats were randomly divided into 5 groups, with 12 rats in each. In group A, autograft was adopted. In group B, the blank PDLLA catheters with PBS inside were used. In group C, PDLLA catheters, with PLGA microfilaments and 30% ECM gel inside, were used. In group D, PDLLA catheters, with PLGA microfilaments, SCs and 30% ECM gel inside, were used. In group E, the tissue engineered nerve was appl ied. After the operation, observation was made for general conditions of the rats. The sciatic function index (SFI) analysis was performed at 12, 16, 20 and 24 weeks after the operation, respectively. Eelectrophysiological detection and histological observation were performed at 12 and 24 weeks after the operation, respectively. Results All rats survived to the end of the experiment. At 12 and 16 weeks after the operation, group E was significantly different from group B in SFI (P lt; 0.05). At 20 and 24 weeks after the operation, group E was significantly different from groups B and C in SFI (P lt; 0.05). At 12 weeks after the operation, electrophysiological detection showed nerve conduct velocity (NCV) of group E was bigger than that of groups B and C (P lt; 0.05), and compound ampl itude (AMP) as well as action potential area (AREA） of group E were bigger than those of groups B, C and D (P lt; 0.05). At 24 weeks after the operation, NCV, AMP and AREA of group E were bigger than those of groups B and C (Plt; 0.05). At 12 weeks after the operation, histological observation showed the area of regenerated nerves and the number of myel inated fibers in group E were significantly differents from those in groups A, B and C (Plt; 0.05). The density and diameter of myel inated fibers in group E were smaller than those in group A (Plt; 0.05), but bigger than those in groups B, C and D (P lt; 0.05). At 24 weeks after the operation, the area of regenerative nerves in group E is bigger than those in group B (P lt; 0.05); the number of myel inated fibers in group E was significantly different from those in groups A, B, C (P lt; 0.05); and the density and diameter of myel inated fibers in group E were bigger than those in groups B and C (Plt; 0.05). Conclusion The tissue engineered nerve with the complex of SCs, ECM gel, bFGF-PLGA sustained release microspheres, PLGA microfilaments and permeables PDLLA catheters promote nerve regeneration and has similar effect to autograft in repair of nerve defects.
Objective To observe the plastic changes of sensory nerve in terms of structure and function when targetorgan changed through making the rat model of nerve regeneration by anastomosing the proximal end of sensory nerve and the distal end of motor nerve. Methods Thirty adult SD rats (male or female), weighing 200-250 g, were randomized into three groups (n=10 per group). The left upper l imb of the each rat was used as the experimental side, while the right upper l imb as the control side. In group A, the medial antebrachial cutaneous nerve was cut 5 mm away from its origin and its proximal end was anastomozed end-to-end to the distal end of musculocutaneous nerve. In group B, the musculocutaneous nerve was cut 5 mm away from its nerve entry point and the proximal end of medial antebrachial cutaneous nerve were anastomozed end-to-end to the distal end of musculocutaneous nerve. In group C, medial antebrachial cutaneous nerve and musculocutaneous nerve were cut, without further anastomosis. Twenty-four weeks after operation, the general condition and the motion of the elbow joint of rats, the wet weight and muscle fiber cross-section area of the biceps brachii as well as the latent period and the ampl itude of the evoked potential were observed and the acetylchol inesterase (AchE) staining of nerve of proximal end of anastomosis was conducted. Results All the rats survived for 24 weeks with good general condition and without wound infection. The rats in groups A, B and C were lost the active flexion of left elbow joint after operation. The rats in groups A and B got recovered to some degree at 24 weeks. The behavioral evaluation showed that there were 7 l imbs in group A and 5 l imbs in group B scoredas 4-5 points, there was a significant difference when compared with group C (P lt; 0.05), but there was no significant difference between group A and group B (P gt; 0.05). Group A and group B were superior to group C in terms of the wet weight and the muscle fiber cross-section area of the biceps brachii (P lt; 0.05), but no significant difference between group A and group B was detected (P gt; 0.05). The evoked potential of the biceps brachii and motor nerve fibers in proximal end of anastomosis could be detected in both group A and group B. But there was no significant difference between group A and group B with respects of function recovery of elbow joint, the latent period and the ampl itude of the evoked potential of the biceps brachii and the quantity of motor nerve fiber in proximal end of anastomosis (P gt; 0.05). Conclusion The change of target organ leads to the sensory nerve plasticity structurally and functionally, which may provide a new approach for peripheral nerve repair.
Schwanns cells were obtained from the distal end of the sciatic nerve following Wallerian degeneration of SD rats. These cells were cultured with the anteriorhorn neuron of spinal cord of 14dayold SD rat fetus. The two kinds of cells were separated by a slice. Through the microscope, the dendrites and the morphology changes at the 24th, 48th, 72th, and 96 th hour after culture were observed. It was demonstrated that the Schwanns cells played the role of maintaining the survival of neuron and promoting the growth of dendrites. It was said that the Schwanns cells could secrete neurotrophic factor which made the body enlarged and caused the dendrites enlonged to several times of the body.
In order to investigate the causes, diagnosis, treatment, outcome and prevention of iatrogenic nerve injury in the neck, 8 cases with iatrogenic nerve injuries were analyzed. Among them, 5 cases were accessory nerve injury, 3 cases were brachial plexus injury. All of the cases were treated by surgical methods, including neurolysis, repair by direct suture, nerve graft and transposition. After 1-3 years follow up the effect was excellent in 2 cases who were accessory nerve injury, good in 5 cases, and poor in 1 case who was brachial plexus injury. It was concluded that high responsibility of surgeons and careful manipulation during operation were the key to prevention of nerve injuries.
Schwanns cell (SC) was isolated from sciatic nerve of adult rat with Wallerine degeneration. After culture, SC-serum free culture media (SCSFCM) was obtained. By ultrafiltration with PM-10 Amicon Membrane, electrophoresis with DiscPAGE,and electrical wash-out with Biotrap apparatus, D-band protein was isolated from the SC-SFCM. The D-band protein in the concentration of 25ng/ml could affect the survival of the spinal anterior horn neuron in vitro, prominently and itsactivity was not changed after being frozen. The molecular weight of the protein ranged from 43 to 67 Kd. The D-band protein might be a neurotrophic substancedifferent from the known SCderived neurotrophic factors (NTF). Its concentration with biological activity was high enough to be detected. The advantages of MTT in assessment of NTF activity were also discussed.