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 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 investigate the distribution of rats’ pelvic muscles motoneurons innervated by artifical somatic-autonomic reflex arc. Methods Thirty-five SD rats were randomly divided into normal group (n=10) and model group (n=25). The rats in the normal group were given no treatment. In the normal group, the artifical somatic-autonomic reflex arc was established. Six months after establishing the model, external urethral sphincter (EUS), ischiocavernosus (IC), bulbocavernosus (BS) and external anal sphincter (EAS) of the rats in normal group(n=10) and of the rats in model group A (n=20) were injected with fluorogold (FG). The reversal neural tracing was done. FG positive neural cells were observedby fluorescent microscope. Malt agglutinator binding horseradish peroxidase (WGA-HRP) was injected into L4 spinal cord of the rats in model group B (n=5) as the anterograde tracer. After being treated with TMB-HRP reaction, the axon endings in the neuromuscular junction in pelvic striated muscles (EUS, IC, BS, EAS) were investigated with light microscopes. Results In normal group, EUS and IC injections resulted in transport of FG to neurons in the dorsolateral nucleus (DL) of the ventral horn of the L5～S1, and BS and EAS in the dorsomedial nucleus (DM) of ventral horn in the L5～S1. In the model group A, EUS, IC, BS andEAS injections resulted in transport of FG to neurons in the left ventral horn in the L4. In model group B, after WGA-HRP was injected into the L4 left ventral horn, HRP positive axon terminals were observed in the EUS, IC, BS and EAS. Conclusion In the normal rats, the pelvic striated muscles motoneurons locate in the ventral horn of L5～S1. In the model rats, the pelvic striated muscles motoneurons innervated by artificial somatic-autonomic reflex arc locate in the ventral horn of the L4. After the artificial somaticautonomic reflex arc is established, the isomerous nerve fiber innervates EUS, IC, BS and EAS.
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.
The translation and translation regulation of RNA in eukaryotic cells have a significant impact on cellular gene expression and maintenance of proteomic homeostasis. Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that affects upper and lower motor neurons and leads to muscle weakness and atrophy. More and more studies have found RNA translation abnormalities in ALS. This article provides an overview of RNA translation and regulation in eukaryotic cells under physiological and stress conditions, and explores the relationship between four different ALS-related genes and translation abnormalities, providing new ideas for the treatment of ALS.
Objective To research the protective effects of different allogeneic cells injected into denervated muscles on ventricornual motor neuron. Methods Thirty-six adult female SD rats, weighting 120-150 g, were individed into four groups randomly and each group had nine. Left ischiadic nerves of all the SD rats, which were cut down on germfree conditions,were operated by primary suture of epineurium. Different cells were injected into the triceps muscles of calf in each group after operation with once a week for 4 weeks:1 ml Schwann cells (1×106/ml) in group A, 1 ml mixed cells ofSchwann cells and myoblast cells (1∶1,1×106/ml) in group B, 1 ml extract from the mixed cells of Schwann cells, myoblast cells and endotheliocytes (1∶1∶1,1×106/ml)in group C,and 1 ml culture medium without FCS as control group(group D). The observation of enzymohistochemistry and C-Jun expression in the ventricornual motor neuron was made after three months of operation. Results After 3 months of operation, the expressions of C-Jun in groups A, B and C were superiorto that in group D; the number of neuron was more than that of group D. The expressions of C-Jun in the ventricornual motor neuron were as follows: 128.591±0.766 in group A, 116.729±0.778 in group B, 100.071±2.017 in group C and 144.648±2.083 in group D; showing statistically significant difference between groupsA, B, C and D(P＜0.01). Enzymohistochemistry showed the well outlined and wellstacked cell body of neuron in groups A, B and C, and illdefined boundary of cytoplasm and nucleus. There was statistically significant defference in enzyme activity of the ventricornual motor neuron between groups(P＜0.01). Conclusion All of the Schwann cells,mixed cells of Schwann cells with myoblast cells,and the extract from Schwann cells, myoblast cells and endotheliocytes can protect the ventricornual motor neuron. And the protectiveeffect of the extract from Schwann cells, myoblast cells and endotheliocytes is superior to that of Schwann cells and mixed cells.
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.
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 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.
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.