Objective To explore the effects of Neurogenesin 1 (Ng1) gene on functional recovery after spinal cord injury (SCI) and its mechanism. Methods Thirty-six rats (aging 4 months, weighing 230 g and being male or female), were randomly divided into two groups: experimental group (n=18) and control group (n=18). After spinal cord contusive injury at T10 level was made in all these rats using modified Allen’s method, Ng1 recombinant plasmid and blank plasmid were transfectedinto the damaged areas of exprimental group and control group respectively by Alzet pumps. At 1 day, 1 week, 2 weeks, 3 weeks, and 4 weeks after SCI, Basso-Beattle-Bresnahan (BBB) Rating Scale was used to observe the recovery of motor function. At 1 week after injury, the expressions of Ng1 mRNA and protein in injured spinal cord were detected by RT-PCR and Western blot techniques. And at 2 and 4 weeks, double immunofluorescence and histopathologic examinations were performed to study the prol iferation of the adult endogenous neural stem cells and pathological change after SCI. Results At 1-4 weeks after SCI, the BBB scores in the exprimental group was significantly higher than that in control group (P lt; 0.05), and at 4 weeks the BBB score of the experimental group (16.80 ± 1.79) was significantly higher than that of the control group (9.60 ± 1.67), (P lt; 0.01). RTPCR and Western blot showed that the mRNA and protein expressions of Ng1 were observed in the exprimental group and no expression was seen in the control group. Histologic observation showed that the morphology of spinal cord and neurons in the exprimental group was better than that in the control group and was close to the normal tissue. The mean number of Nestin+/ BrdU+ newborn endogenous neural stem cells in the exprimental group was significantly more than that in control group (P lt; 0.05). Conclusion Ng1 gene could promote the prol iferation of endogenous neural stem cells and protect the injured neurons, which enhances the repair of the motor function after SCI.
OBJECTIVE: To investigate the variation of neurotrophic factors expression in spinal cord and muscle after root avulsion of brachial plexus. METHODS: Forty-eight Wistar rats were involved in this study and according to the observing time in 1st day, 1st week, 4th week, 8th week, and 12th week after avulsion, and the control, were divided into 6 groups. By immunohistochemical and hybridization in situ assays, the expression of nerve growth factor (NGF) on muscle, basic fibroblast growth factor(bFGF) and its mRNA on the neurons of corresponding spinal cord was detected. Computer image analysis system was used to calculate the result. RESULTS: After the root avulsion of brachial plexus occurred, expression of NGF increased and reached to the peak at the 1st day. It subsided subsequently but was still higher than normal control until the 12th week. While expression of bFGF and its mRNA increased in the neurons of spinal cord and reached to the peak at the 1st week. Then it dropped down and at the 12th week it turned lower than normal control. CONCLUSION: After root avulsion of brachial plexus, neurotrophic factors expression increase on target muscle and neurons of corresponding spinal cord. It maybe the autoregulation and may protect neuron and improve nerve regeneration.
Ten cases of neurotmesis of posterior interosseous nerve of the forearm were treated with mierosurgical technique from Aug, 1988 to Oct. 1990, of which, 4 cases by autogenous nerve graft and 6 cases by direct neurosuture. Eight cases have been followed-up from 4 months to 1 year after operation concerning with satisfactory results. Some questions the diagnosis, the points for attention in operation, and the relation of the results and the time when the operation done were discussed. The comparison of the results and the recovery time between the autogenous-nerve graft and direct neurosuture was made.
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.
Purpose To investigate the characteristics of intraocular growth of mice embryonic stem cells (ESC) in nude mice. Methods The undifferentiated murine ESC in vitro were transplanted into the eyes of nude mice.Mophological and immunohistochemical examinations were implemented. Results Two to three days after transplantation,yellowish-white granules and masses were seen inside the anterior chamber and vitreous cavity and enlarged gradually.Morphological examination showed that there were undifferentiated cells and differentiated cells in anterior chamber and vitreous cavity.The morphology and alignment of some differentiated cells were similar to those of the retina of nude mice.The cells were highly positive in NSE staining. Conclusion The transplanted ESC could grow in the eyes of nude mice and differentiate into neurons and retina-like structure. (Chin J Ocul Fundus Dis，2000，16：213-284)
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.
In this experiment, two proximal ends of themedian and ulnar nerves of rabbit wereapproxirnated within the chitin tube for thepurpose to inhibit the neuroma formation. Byobservation under light and transmission electronmicrnscopo and immunohistochemistry, wefound that: (1) the axons of the two proximalstumpe could regenerate in the chitin tube for 2to 5mm, and then ceased to grow when anaxonal overlap happened resulting in inhibitingneuroma formation; (2) chitin tube could bedegradated a...
Objective To investigate the rule of the morphological changes of the detrusor muscle and its neuromuscular junction after the medullary cone injury in rats. Methods Forty-eight SDadult rats were divided into 6 groups randomly, each of which was 8. There werenormal control group(group A), 4 weeks group(group B), 6 weeks group(group C), 8 weeks group(group D), 10 weeks group(group E) and 12 weeks group(group F) after the medullary cone injury respectively. The medullary cone injury was completed in the level of L4,5 with a sharp and transsectional way. The HE dyeing of the detrusor muscle was performed firstly to observe the changes of the section areas of muscle fibers. And the electron microscopic samples of the detrusor muscle were made to investigate the rules of the ultrastructructral changes in the detrusor muscle and its neuromuscular junction. Finally, the Masson trichromatic dyeing of the detrusor muscles was performed to calculate the percentages of the smooth muscle and the connective tissue.Results The HE dyeing of the detrusor muscle indicated the section areas of muscle fibers in groups E, F was significantly less than that in group A (P＜0.05). The gradually aggravated ultrastructructral changes of detrusor cells in groups B-F were observed in atonic bladders，such as various shape and size，malalignment, wide separation between musclecells, abundant collagen fibrils and irregular dense structures between individual cells, obvious rough endoplasmic reticulum widen and mitochondrial edema were noted．And the ultrastructructral changes of the neuromuscular junctions manifested that the similar structures in group A and the reduction of the mitochondria and synaptic vesicles was seen in groups B, C and D, the conspicuous degenerative neuromuscular junction and the obvious reduction of the synaptic vesiclesand the mitochondria was observed in group E,and the deteriorative degenerativeneuromuscular junction and the obvious reduction or disappearance of the synaptic vesicles and the mitochondria even to the degenerative corpuscle was noted in group F. The Masson trichromatic dyeing in the detrusor muscles indicated that there were significant differences in the percentage of the connective tissue in the detrusor muscles between groups E,F and group A, and between group E and group F respectively (P＜0.05). Conclusion The irreversible changes of the detrusor muscle and its neuromuscular junction canbe seen in the 10th week after medullary cone injury in rat. And the nerverepairing procedures should be performed before this.
In order to investigate the effect of nerve compression on neurons, the commonly used model of chronic nerve compression was produced in 48 SD rats. The rats were sacrificed in 1, 2, 3, 4, 5 and 6 months after compression, respectively. The number of neuron and ultrashruchure of alpha-motor neurons and ganglion cells of the corresponding spinal segment were examined. The results showed as following: After the sciatic nerve were crushed, the number of neuron and ultrastructure of alpha-motor neurons and ganglion cells might undergo ultrastructural changes, and even the death might occur. These changes might be aggravated as the time of crushing was prolonged and the compression force was increased. It was concluded that for nerve compression, decompression should be done as early as possible in order to avoid or minimize the ultructural changes of the neuron.
ObjectiveTo evaluate the effectiveness of Cross-Union surgery for the treatment of pseudarthrosis of the tibia (PT) with neurofibromatosis type 1 (NF1). MethodsThe clinical data of 8 children of PT with NF1 who met the selection criteria between January 2018 and December 2023 was retrospectively analyzed. There were 5 boys and 3 girls, and the operative age ranged from 1.8 to 13.3 years with a median age of 3.5 years. According to Paley classification, there were 2 cases of type 2a, 2 cases of type 3, 2 cases of type 4a, and 2 cases of type 4c. There were 5 cases of first operation and 3 cases of re-fracture after previous operation. Six cases had leg length discrepancy before operation, and 2 of them had shortening over 2.0 cm. Except for 1 case of ankle fusion, the other 7 cases had ankle valgus. Preoperative coronal/sagittal angulation was recorded. Postoperative pseudarthrosis healing and refracture were observed. Leg length discrepancy and tibiotalar angle were measured and recorded before operation and at last follow-up. Inan imaging evaluation criteria was used to evaluate the imaging effect. ResultsAll patients were followed up 12-37 months (mean, 23.5 months). One pseudarthrosis failed to heal at 12 months after operation and healed at 3 months after reoperation, while the other pseudarthrosis healed with a healing rate of 87.5% and a healing time of 4-8 months (mean, 5.3 months). No refracture occurred during the follow-up. At last follow-up, there were 2 new cases with leg length discrepancy, which were 0.7 cm and 1.3 cm, respectively. In 2 cases with the leg length discrepancy more than 2.0 cm before operation, the improvement was from 4.1 cm and 12.6 cm to 2.1 cm and 9.0 cm, respectively. There was no significant difference in leg length discrepancy between pre- and post-operation in 8 cases (P>0.05). At last follow-up, 6 patients still had ankle valgus, and there was no significant difference in the tibiotalar angle between pre- and post-operation (P>0.05); the tibial coronal/sagittal angulation significantly improved when compared with that before operation (P<0.05). According to Inan imaging evaluation criteria, 1 case was good, 6 cases were fair, and 1 case was poor. Conclusion Cross-Union surgery is an effective method for the treatment of PT with NF1 in children, can achieve good bone healing results with a low risk of re-fracture. The surgery may not have significant effects on leg length discrepancy and ankle valgus, and further treatment may be required.