Nine cases of sciatic nerve from injection hadbeen treated by fasciotomy. The skin temperatureof the diseased limb immediately raised 1-2℃ fol-lowing operation. The cutaneous sensation began torecover 2-3 days after operation. Two cases ofplantar ulcer recovered one month post operation.Five of the eight cases of paralysis of muscle in-nervated by the common peroneal nerve recoveredto normal. The etiology,pathology, and therapeuticmethods of the nerve injury caused by drug injec-tion were discused.
Objective To investigate the expression change of endogenous Spastin after sciatic nerve injury in rats, and to discuss the role and significance in the peripheral nerve regeneration. Methods Thirty-six adult male Sprague Dawley rats weighing 180–220 g were randomly divided into the experimental group (n=30) and the control group (n=6). Sciatic nerve compression damage model was established in the experimental group, and the sciatic nerve was only exposed in the control group. The L4-6 spinal cord tissue was obtained to detect Spastin mRNA and protein levels by real-time fluorescence quantitative PCR and Western blot at 1, 3, 7, 14, and 28 days after operation in the experimental group (n=6) and at 7 days in the control group. Meanwhile, the sciatic nerve at 5 mm distal to the injured site was obtained to observe the ultrastructure of the distal axon by transmission electron microscope (TEM). Results The expression trends of Spastin gene and Spastin protein in L4-6 spinal cord tissue of 2 groups were basically identical. In the experimental group, the expressions of Spastin gene and protein decreased at the beginning, and then increased; the expressions reduced to the minimum at 7 days after operation, and came back to the initial level at 28 days. The expression levels of Spastin mRNA and protein at 3, 7, and 14 days were significantly lower in the experimental group than the control group (P<0.05), but no significant difference was noted between 2 groups at 1 and 28 days (P>0.05). The expression levels of Spastin mRNA and protein at 3, 7, and 14 days were significantly lower than those at 1 and 28 days in the experimental group (P<0.05), but no significant difference was noted between at 1 day and 28 days (P>0.05). At 1, 3, and 7 days after operation, the myelin damage was observed by TEM; at 14 days, there were regenerating Schwann cells; at 28 days, a large number of myelinated nerve fibers were seen, which were closed to normal form. Conclusion In the process of sciatic nerve regeneration after injury, a complex succession of changes take place in the expression of endogenous Spastin protein in rats, indicating that Spastin protein plays an important role in the process.
Objective To observe the result of reconstructing quadriceps femoris function in the paraplegia rats by using the 7th cervical nerve root (C7) transposition with autologous and allogeneic neural transplantation. Methods Twenty16-week-old SPF male Wistar rats were adopted to prepare frozen sciatic nerve. Thirty-six Wistar rats were divided into 2 groups (group A and group B, n=18). The left paraplegia model was establ ished with left spinal cord hemisection by the micro scissors under the operation microscope. After the model establ ishment, the homolateral autologous sciatic nerve was bridged with the femoral nerve root by the translocation of C7 in group A, while the allogeneic sciatic nerve was bridged with the femoral nerve root by the translocation of C7 in group B. At 16 weeks and 24 weeks after operation, 9 rats in each group were selected for the neuroelectric-physiological test and then the histomorphology of the nerves was observed under the microscope and the electron microscope. The fresh weight recovery rate of quadriceps femoris was calculated. Results At 16 and 24 weeks after operation, the nerve action-evoked potential (NAP) was (1.14 ± 0.07) mV and (1.21 ± 0.07) mV in group A, and (0.87 ± 0.06) mV and (0.99 ± 0.05) mV in group B; the nerve conduction velocity (NCV) was (17.34 ± 2.15) m/s and (19.00 ± 3.02) m/s in group A, and (11.23 ± 1.45) m/s and (12.54 ± 1.59) m/s in group B, respectively, indicating significant differences (P lt; 0.05) between 2 groups. At 16 and 24 weeks after operation, HE staining and Bielschowsky staining showed that group A had a large number of nerve fiber regeneration, with a regular arrange of axons; while group B had l ittle nerve fiber regeneration with a scattered arrange of axons. At 24 weeks after operation, images in TEM showed a large number of regeneration myel inated nerve fibers and a small number of unmyel inated nerve fibers through the transplanted nerve in two groups. At 16 weeks after operation, the number of myel inated nerve fibers in group A and group B was (438 ± 79) and (196 ± 31) / vision, the areas of myel inated nerve fiberswere (5 596.00 ± 583.94) and (4 022.63 ± 615.75) μm2 / vision; after 24 weeks, the number of myel inated nerve fibers in groups A and B were (642 ± 64) and (321 ± 75)/vision, the areas of myel inated nerve fibers were (6 689.50 ± 1 142.10) and ( 4 733.00 ± 982.22) μm2/vision, indicating significant differences between two groups (P lt; 0.05). There was no statistically significant difference (P gt; 0.05) in the wet weight recovery rate of quadriceps between group A and group B at 16 weeks (87.96% ± 4.93% vs. 86.47% ± 7.47%) and at 24 weeks after operation (90.10% ± 4.22% vs. 87.66% ± 3.14%). Conclusion C7 transposition combined with autograft and allograft of sciatic nerve can reconstruct the partial function of the quadriceps femoris in paraplegia rats. The effect of graft is better than that of graft obviously.
Abstract In case of sciatic nerve injury, there is degeneration of neuron in the corresponding segment of spinal cord. To study whether NGF could protect the dorsal root ganglia in this situation, the following experiments were performed: 72 SD mice were divided into 2 groups. In each mouse, the sciatic nerve was sectioned at the middle of the right thigh, and then,the proximal end of the sciatic nerve was inserted into a one ended silastic tube. The NGF 0.15ml (contain 2.5S NGF 0.15mg) was injected into the tubes of the experimental group, while a equal amount of normal saline was injected into the tubes of the control group. After 1, 3, 5, 9, 20 and 30 days, 6 mice of each groupwere sacrificed respectively, and 5th to 6th lumbar segments of the spinal cords were resected for examination. By histochemical study, the activity of fluoride resistant acid phosphatase (FRAP) of each animal was detected. The results showed: (1) Excision of the sciatic nerve led to decrease of FRAP activity, it suggested that the injury of sciatic nerve could damage the dorsal root ganglia; (2) The use of exogenous NGF could protect the FRAP activity. It was concluded that NGF played an important role in protecting the dorsal root ganglia in peripheral nerve injury, in vivo.
OBJECTIVE: To investigate the mechanism, diagnosis, and treatment of common fibular nerve compression syndrome secondary to sciatic nerve injury. METHODS: Based on the clinical manifestation and Tinel’s sign at fibular tunnel, 5 cases of common fibular nerve secondary compression following sciatic nerve injury were identified and treated by decompression and release of fibular tunnel. All 5 cases were followed up for 13-37 months, 25 months in average, and were evaluated in dorsal flexion strength of ankle. RESULTS: The dorsal flexion strength of ankle in 4 cases increased from 0-I degrees to III-V degrees, and did not recover in 1 case. CONCLUSION: Fibular tunnel is commonly liable to fibular nerve compression after sciatic nerve injury. Once the diagnosis is established, either immediate decompression and release of the entrapped nerve should be done or simultaneous release of fibular tunnel is recommended when the sciatic nerve is repaired.
ObjectiveTo investigate the regularity of myelin degeneration and regeneration and the difference of axonal density between tibial nerve and common peroneal nerve after sciatic nerve injury repair in rhesue monkey. MethodsNine adult rhesue monkeys (male or female, weighing 3.5-4.5 kg) were selected to establish the model of rat sciatic nerve transaction injury. The tibial nerve and common peroneal nerve of 5 mm in length were harvested at 5 mm from injury site as controls in 3 monkeys; the distal tibial nerve and common peroneal nerve were repaired with 9-0 suture immediately in the other 6 monkeys. And the gross observation and neural electrophysiological examination were performed at 3 and 8 weeks after repair respectively. Then, distal tibial nerve and common peroneal nerve at anastomotic site were harvested to observe the myelin sheath changes, and to calculate the number of axon counts and axonal density by staining with Luxol Fast Blue. ResultsAtrophy of the lower limb muscle and various degrees of plantar ulcer were observed. Gross observation showed nerve enlargement at anastomosis site, the peripheral connective tissue hyperplasia, and obvious adhesion. The compound muscle action potential (CMAP) of tibial nerve and common peroneal nerve could not be detected at 3 weeks; the CMAP amplitude of common peroneal nerve was less than that of the tibial nerve at 8 weeks. Different degrees of axonal degeneration was shown in the tibial nerve and common peroneal nerve, especially in the common peroneal nerve. The average axonal density of common peroneal nerve was lower than that of tibial nerve at 3 weeks (13.2% vs. 44.5%) and at 8 weeks (10.3% vs. 35.3%) after repair. ConclusionThe regeneration of tibial nerve is better and faster than that of common peroneal nerve, and gastrocnemius muscle CMAP recovers quicker, and amplitude is higher, which is the reason of better recovery of tibial nerve.
ObjectiveTo observe the changes of microstructure of rats'sciatic nerves with non-freezing cold injury after treated with dexamethasone. MethodsTwelve male Wistar rats were randomly divided into cooling group and treating group.Unilateral sciatic nerves of the rats in the cooling group received cooling treatment with 3-5℃ for 2 hours;while unilateral sciatic nerves of the rats in the treating group received cooling treatment with 3-5℃ for 2 hours and underwent the celiac injection with dexamethasone in addition.The other sciatic nerves were exposed,as the control.The bilateral sciatic nerves of rats in each group were harvested after 24 hours.The microstructure of nerves was examined under the light microscope and electron microscope. ResultsLight microscopic examination revealed extensive myelinated fibre degeneration in form of giant empty axons or shrunken dark axons on the first day after cooled.And the endoneurial capillary lumen was narrowed because of swollen endothelial cells.After the treatment,myelinated fibre degeneration was still similar to that before the treatment,but the endoneurial capillary lumen and endothelial cells were normal.By electron microscopy,sciatic nerves showed extensive myelinated fiber degeneration,and swollen endothelial cells.But unmyelinated fibers and tight junction were preserved on the first days after cooled.Aggregated red cells and platelet thrombus were not found.After the treatment,myelinated fibre degeneration was still similar to that before the treatment.Unmyelinated fibers and tight junction were preserved.The endoneurial capillary lumen and endothelial cells were normal. ConclusionAfter the treatment,the damage of endoneurial capillary had improved,but myelinated fiber degeneration was similar to that before the treatment.It suggested that dexamethasone may only improve the vascular system in non-freezing cold injury of sciatic nerve.
ObjectiveTo construct recombinant adenovirus expressing nerve growth factor (NGF) and myelin associated glycoprotein (MAG) (Ad-NGF-MAG) and to investigate its effect on repair and regeneration of sciatic nerve injury in rats. MethodsNGF and MAG gene sequences were cloned into shuttle plasmid pCA13 of adenovirus type 5. After packed in HEK293 cells, the recombinant Ad-NGF-MAG underwent sequence and identification. Thirty-two male Sprague Dawley rats were randomly divided into 4 groups (n=8): control group (normal control), adenovirus vector group (Ad group), Ad-NGF group, and Ad-NGF-MAG group. The sciatic nerve injury model was established by transection of the right sciatic nerve; then, the empty adenovirus vector, Ad-NGF, and Ad-NGF-MAG were injected into the gastrocnemius muscle of the affected limb at a dose of 1×108 PFU every other day for 3 times in Ad group, AdNGF group, and Ad-NGF-MAG group, respectively. The right sciatic nerve was exposed only, and then the incision was closed in the control group. The sciatic nerve function index (SFI) was measured, and neuro-electrophysiology was observed; mRNA and protein expressions of NGF and MAG were detected by RT-PCR and Western blot; and histological examination was performed at 31 days after operation. ResultsRecombinant adenovirus vectors of Ad-NGF and Ad-NGF-MAG were constructed successfully. All rats survived and incision healed by first intension. The SFI, nerve conduction velocity, evoked potential amplitude, and latent period of Ad-NGF-MAG group were significantly better than those of Ad group and Ad-NGF group (P < 0.05). MAG mRNA and protein expressions of Ad-NGF-MAG group were the highest in all the groups (P < 0.05). The expressions of NGF mRNA and protein increased in Ad-NGF group and AdNGF-MAG group when compared with control group and Ad group (P < 0.05). Histological examination showed that the nerve had good continuity in control group; nerve fibers disarranged in Ad group; neurons connections formed in some nerve fibers of Ad-NGF group, but nerve fibers arrange disorderly; and the growth of the nerve were ordered and wellstructured in Ad-NGF-MAG group. ConclusionAd-NGF-MAG can effectively promote the growth of the nerve and inhibit the form of abnormal branches, facilitating the repair of sciatic nerve injury in rats.
Objective To investgate the effects of neurotrophic factor 3 (NT-3) genes modified SC on facil itating nerve regeneration and protecting neuronal survival after the sciatic nerve transection in rats. Methods The double sciatic nerves were harvested from 3-day-old Wistar rats and the SCs were separated, cultured and purified with double enzyem digestion and adherent culture. The third generation purified SCs were used. The NT-3 cDNA gene was transfected into culturedSCs by using cationic l iposome. The NT-3 expression were identified by ELISA after 1, 2, 4 and 8 weeks. The plasmids expressing NT-3 genes were transfected into SCs with l ipofectamine. The purity of SCs were detecting before and after modified with NT-3. The nerve-grafting complexes were constructed by SCs (3 × 107/mL) modified NT-3, third generation SCs (3 × 107/mL), NT-3 gene, respectively. And the nerve-grafting complexes were combined with ECM gel and PLGA conduit. Forty-eight adult SD rats were made the models of the right sciatic nerve defect (10 mm). According to the nerve-grafting complexes which were repaired the sciatic nerve defects, the models were divided into 4 groups randomly (n=12): group A (ECM gel and PLGA conduits), group B (SC, ECM gel and PLGA conduits), group C (NT-3 gene, ECM gel and PLGA conduits) and group D (NT-3 modified SC, ECM gel and PLGA conduits). At 2, 4, 6, 8 and 12 weeks after operation, the nerve gross were observed. Electrophysiological examination, histological observation and transmission electron microscope observation were performed at 12 weeks after operation. Results The concentrations of NT-3 protein were 0.39 ± 0.25, 0.76 ± 0.22, 1.06 ± 0.38 and 1.61 ± 0.35 at 1, 2, 4 and 8 weeks after operation; showing statistically significant differences (P lt; 0.05). The purity of SCs was 94.7% ± 2.1% and 95.6% ± 2.5% before and after modified with NT-3, respectively; showing a statistically significant difference (P lt; 0.05). The feet of injury rats began inflammation and ulcer, which healed at 12 weeks in group D, followed by groups C and B, but which was serious in group A gradually. The observations of gross, sections under microscope and transmission electron microscope at 12 weeks showed the regeneration of defect nerve was best in group D, followed by groups C and B, and group A was worst. There were statistically significant differences (P lt; 0.05) in latent period, ampl itude, motor nerve conduction velocity, the number and thickness of axon, the diameter of nerve fiber, the percentage of the nerve tissue area between group A and groupsB, C, D, between groups B, C and group D at 12 weeks. At 12 weeks after operation, the transmission electron microscope showed observation the maturation of medullary sheath was best in group D, followed by groups C and B, and group A was worst. Conclusion The nerve-grafting complex of NT-3 genes modified SCs could repair injured nerve. The competence is superior to SCs and neurotrophic factors.