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.
OBJECTIVE To study the protective effects of Schwann cell derived neurotrophic factor (SDNF) on motoneurons of spinal anterior horn from spinal root avulsion induced cell death. METHODS Twenty SD rats were made the animal model of C6.7 spinal root avulsion induced motoneuron degeneration, and SDNF was applied at the lesion site of spinal cord once a week. After three weeks, the C6.7 spinal region was dissected out for motoneuron count, morphological analysis and nitric oxide synthase (NOS) enzyme histochemistry. RESULTS 68.6% motoneurons of spinal anterior horn death were occurred after 3 weeks following surgery, the size of survivors was significantly atrophy and NOS positive neurons increased. However, in animals which received SDNF treatment, the death of motoneurons was significantly decreased, the atrophy of surviving motoneurons was prevented, and expression of NOS was inhibited. CONCLUSION SDNF can prevent the death of motoneurons following spinal root avulsion. Nitric oxide may play a role in these injury induced motoneuron death.
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 the clinical characteristics of mulifocal motor neuropathy. Methods Patients records in China Biological Medicine Database (CBM-disc 1980-2005)and WanFang Database were searched. Demographic data, clinical manifestations, electrophysiology, and laboratory findings on multifocal motor neuropathy were analyzed. Results Of the total 80 patients, 61 cases were males, and 19 were females. A single limb weakness began in all the patients. Weakness was usually accentuated distally(95.3%), accompanied by muscle amyotrophy(76.3%) and fasciculation(46.3%). Reflexes were reduced (96.4%). Sensory impairment and cranial involvement were rare. 92.1% of the patients showed conduction block of motor nerve. Results Of the total 80 patients, 61 cases were males, and 19 were females. A single limb weakness began in all the patients. Weakness was usually accentuated distally(95.3%), accompanied by muscle amyotrophy(76.3%) and fasciculation(46.3%). Reflexes were reduced (96.4%). Sensory impairment and cranial involvement were rare. 92.1% of the patients showed conduction block of motor nerve. Conclusions Clinical features about multifocal motor neuropathy are a single distal limb weakness, muscle amyotrophy, and conduction block of motor nerve. MMN should be differentiated from motor neuron disease and chronic inflammatory demyelinating polyneuropathy.
To establ ish the animal model of the artificial physiological reflex arc with the reconstruction of the sensory and the motorial functions of atonic bladder simultaneously in the rats, and to provide the foundation to furtherinvestigate the repairing effectiveness of this technique. Methods There were 20 adult male SD rats (weighing 280-300 g)which were randomly divided into 2 groups (n=10): group A and group B. Group A was anastomosis of the ventral roots(VR) and the dorsal roots (DR) between L6 and S2 simultaneously to establ ish the model of the artificial physiological reflex arc. Group B was anastomosis of the main trunk between L6 and S2 to establ ish the model. The contents of the observation included: ① To measure the external diameter of the VR, DR and the main trunk of L6 and S2 with the sl iding cal iper; and to measure not only the distance between L6 and S2 but also the separable length of L6 with the ruler. ② Fast Blue dyeing of the VR, DR and the main trunk of L6 and S2 was performed to count their nerve fibers assisted by the Leica FW4000 system 2 weeks after opertation. ③ The observation of the urination of the rat and BBB scoring to evaluate the motorial function of the lower l imbs was performed postoperatively. Results ① L6 located in the lateral side of the S1-4 in the vertebral body of L6. The external diameters of the VR, DR and the main trunk of L6 were (0.68 ± 0.13), (0.88 ± 0.10) and (1.54 ± 0.33) mm, respectively, while those of S2 were (0.62 ± 0.08), (0.79 ± 0.14) and (1.39 ± 0.42) mm, respectively. The distance between L6 and S2 was (14.21 ± 1.95) mm, and the separable length of L6 was (10.76 ± 2.11) mm. Furthermore, the microdissection indicated the VR and the DR between L6 and S2 could be anastomosed respectively with no-tension at the level of the vertebral body of L6; and the main trunk of L6 and S2 could be anastomosed with no-tension at the level of the confluens of L5, 6. ② With Fast Blue dyeing, there were 892 ± 32, 354 ± 26 and 532 ± 17 nerve fibers of the VR, DR and the main trunk of L6, respectively. And there were 788 ± 29, 325 ± 19, and 478 ± 22 nerve fibers of the VR, DR and the main trunk of S2, respectively. There were no volar ulcer,trichomadesis and self-eating of the affected l imbs in the both groups postoperatively. The urinations of the rats after operationwere not different from those before operation. The mean BBB scores of pre- and postoperation in group A were 20.20 ± 0.35 and 19.80 ± 0.23, respectively; the mean BBB scores of pre- and postoperation in group B were 20.20 ± 0.35 and 19.20 ± 0.31, respectively. There was no significant difference of the above indexes between group A and group B (P gt; 0.05). Conclusion Anastomosis of the VR and the DR between L6 and S2 simultaneously in rats is an ideal animal model to establ ish the artificial physiological reflex arc owing to its simple and reproducible procedures.
OBJECTIVE: To purify and study Schwann cells cytoplasmic neurotrophic protein. METHODS: The dissociated SC taken from 300 newborn rats sciatic nerves were cultured, collected, ultrasonicated and ultraspeed centrifuged. The supernates were ultrafiltrated and concentrated by using ultrafiltration units with PM10, PM30, PM50 ultrafiltration membranes. The ultrafiltrated-concentrated solution with the protein molecular weight 10-30 ku, 30-50 ku and gt; 50 ku were collected respectively. The dissociated spinal cord motoneurons of 14 days embryonic rats were cultured with serum-free conditional medium and the additional SC cytoplasmic proteins were added into the medium. The results showed that the 10-30 ku and gt; 50 ku SC cytoplasmic proteins were able to maintain the survival of motoneurons for 24 hours. Then the 26 ku and 58 ku proteins were further extracted and purified from SC cytoplasm by high pressure liquid chromatography, and their neurobiological activities were studied. RESULTS: The 26 ku and 58 ku Schwann cell’s cytoplasmic proteins were able to maintain the survival of motoneurons cultured in the serum-free medium for 48 hours. The highest biological activity concentration is 20 ng per well. CONCLUSION: Schwann cells cytoplasm contains motoneuron neurotrophic proteins with molecular weight 26 ku and 58 ku.
The object of this experimental study was to investigate the influence of low-energy He-Ne laser on the motor nerve cells of the spinal cord. The experimental study included as follws: (1) Four rabbits were used in this experiment. The L5-6 spinal cord segment was irradiated by He-Ne laser percutaneously, the nerve velocity of the comon peroneal nerve was measured in order to determine the function of the spinal motor nerve cells when the peripheral nerve was intact. (2) The common peroneal nerve was transected on one side wothout repair, two weeks after laser irradiation, the grey mater of the spinal cord of L5-6 segment was procured for electronic microscopic examination. (3) The common peroneal nerve on the contralateral side was transected and followed by end-to-end anastomosis, and laser irradiation was done on the same spinal cord segment. Two weeks after irradiation, the nerve velocity of the common peroneal nerve and the toe expanding test were investigated. The results were: (1) the He-Ne laser can influence the spinal motor nerve cells function as expressed by latent rate when the peripherial nerve is intact. i.e. the nerve velocity is slower than mormal, and the amplitude is markedly decreared. (2) the change of the microstructure of the spinal motor nerve cells is comparatively slight in the 10 and 15 minutes groups. (3) the recovery of the nerve velocity and the toe expansion are more earlier in the 15 min. group. In short, the low-energy He-Ne laser can influence the function of the spinal motor nerve cells.
Objective To review research progress of the relation between glial cell line-derived neurotropic factor (GDNF) and motoneuron development and motoneuron disease. Methods The recent articles on GDNF and motonerons were extensively reviewed. The molecular structure, the mode of action and the route of administration of GDNF were investigated. Results GDNF plays extensive roles in the development anddisease of motoneuron. GDNF might regulate the development of the motonerons of the spinal cord to some extent and also save the injured motoneurons. Conclusion GDNF has a potential clinical value and inestimable futurein the treatment of motoneuron diseases.
Objective To summarize the clinical features of motor neuron disease ( MND) with main presentation of pulmonary hypertension, so as to improve the diagnosis.Methods A patientwithMND whose main presentation was pulmonary hypertension was analyzed retrospectively. Meanwhile related literatures were reviewed. Clinical data including symptoms, early signs, misdiagnosis causes, and necessary functional examination of respiratory muscle were collected. Results The symptoms of MND was slow-onset and insidious with gradual progression over time. History inquiring found that the symptoms of muscle wasting and physical debilitation emerged long time before the respiratory symptoms. Physical examination also revealed obvious sign of muscle atrophy. Conclusions MND with main presentation of pulmonary hypertension has been recognized insufficiently and often misdiagnosed as other pulmonary diseases. Detailed history taking, systematic physical examination, and convenient functional examination of respiratory muscle,can not only reduce misdiagnosis, but also avoid some expensive and traumatic process.