After an injury of the peripheral nerve, therewould be naturally occurring the reduction oreven disappearance of FRAP from the substantiagelatinase in the corresponding part of the dorsalhorn of the spinal cord, The enzymhistochemical method was used to show the changesof FRAP activity before and after the nerveinjury. Aftcr the injury of the sciatic nerve,FRAP would be decreased in the correspondingpart of the spinal cord and gave a sharp contrastto that of the control rats and the uni...
A comparative study of four methods of laryngeal muscle reinnervation in dogs is presented. Twenty-eight cases were divided into four groups to undergo main branch and branch of ansa cervicalis nerve anastomosis, and nerves implantation an neuromuscular pedicles transfer respectively for restoration of vocal cord adduction on left sides. The results showed that the four procedures seemed to induce effective reinnervation of adductor muscles. But the main branch of ansa cervicalis nerve suture was superior to the other methods among which little difference was noted in the functional recovery, electrophysiological activity and muscle strength. It demonstrated that main branch of ansa nerve suture was the best procedure for treatment of unilateral vocal cord paralysis among the four methods.
Objective To establish an animal model for repairing the sciatic nerve defect with a biodegradable poly D,L-lactic acid/nerve growth factor (PDLLA/NGF) that can control the release conduit in rats and to observe an effect of the conduit on the sciatic nerve regeneration. Methods The PDLLA conduit and the PDLLA/NGF-controlled release conduit (NGF 450 U per conduit) were madewith the solvent-volatilixation method. Forty male SD rats were randomly and equally divided into 4 groups. The middle segments (10 mm) of the sciatic nerves of the rats were excised and were then repaired with the sciatic nerve autograft(Group A), with the PDLLA conduit (Group B), with the PDLLA conduit and an injection of NGF (30 U) into the conduit (Group C), and with the PDLLA/NGF controlled-release conduit (Group D), respectively, with the 10-mm nerve defect left behind. Three months after operation, the morphologic parameters of the nerve regeneration were observed and evaluated under light microscope and electron microscope, and the image analysis was also made. Results Three months after operation, porous adherence between the conduit and the surrounding tissues could be observed. The conduit presented a partial biodegradation but still remainedintact in the outline and the proximal nerve regenerated through the conduit cavity. Based on the histological observation, the quantity, uniformity, and maturity of the nerve fiber regeneration in Groups A and D were better than those in Groups B and C. The image analysis indicated that there were no significant differences in the nerve fiber diameter, axon diameter or myelin thickness between Group A and Group D (P＞0.05). However, all the parameters in Groups A and D were better than those in Groups B and C (P＜0.05). Conclusion The PDLLA/NGF-controlled release conduit can effectively promote the sciatic nerve regeneration of rats. Its morphological index is similar to that of the nerve autograft.
Objective To investigate the protective effect of nerve growth factor (NGF) on apoptosis of cultured human fetal retinal pigment epithelium (HFRPE) cells induced by indomethacin (IN) in vitro.Methods Subcultured HFRPE cells were treated with different concentrations of IN to establish apoptotic model. The protective effect of NGF on apoptosis of cultured HFRPE cells were assessed using an acridine orange (AO) staining method and transmission electron microscopy (TEM).Results HFRPE cells exposed by 200-600 μmol/L IN for 24 hours elicited typical apoptosis morphological changes, including condensed chromation, nuclear fragmentation and reduction of nuclear size and cell volume. There was a statistically difference in HFRPE cells with apoptosis between 200 μmol/L IN+500 μg/L NGF and 200 μmol/LIN groups ( q=3.9204，P=0.0320); there was a significant difference in HFRPE cells with apoptosis in 400 μmol/L IN+500 μg/L NGF and 400 μmol/ L IN as well (q=9.7915，P=0.0001). Conclusion NGF has an protective effect on IN-induced HFRPE cells apoptosis. (Chin J Ocul Fundus Dis，2003，19：38-41)
OBJECTIVE To study the compression factor and clinical manifestation of the compression of the palmar cutaneous branch of the median nerve. METHODS Anatomic study was done on both sides of 2 cadavers and 6 cases of hand injury in the debridement, the origin, course, branch of the palmar cutaneous branch of the median nerve were observed. From 1995 to 1998, 12 patients of compression of the palmar cutaneous branch were treated by local blockade injection. Among them, there were 8 males and 4 females, aged from 23 to 65 years and the course of disease ranged 3 to 12 months. RESULTS The palmar cutaneous branch of the median nerve was (1.3 +/- 0.1) mm in diameter, it could be pulled when the wrist dorsi-extension. All cases showed good recovery of hand function and no recurrence after 4 to 12 months follow-up. CONCLUSION The palmar cutaneous branch compression syndrome is closely related to the local anatomy. The diagnosis is definite according to the clinical symptoms and signs, and local blocking is effective on the most patients.
Objective To know the possibility of nerveregeneration after artery sleeve anastomosis and end-to-side suture Methods Seventy-five SD rats were divided into 5 groups. First, the distal end ofsevered peroneal nerve was sutured end-to -side with artery sleeve anastomosis withnormal nerve tibial trunk in groups A, B, C and D. Second, the tibial epineurium at the suture site was not removed in group A; the epineurium at the suturesite was removed(windowing) in group B; the distal end of pre-injured peroneal nerve was sutured after 14 days and windowing was done in group C; and the neural growth factor was injected into artery sleeve and windowing was done in group D. While the distal end of severed peroneal nerve was sutured end to side directly with normal nerve tibial trunk and windowing was done in group E. The histological observation was made and the number of nerve fibers was recorded after 4, 8 and 12 weeks of operation.Results After 4 weeks, there existed the regeneration of axons and myeline sheaths in groups C, D, E, and no nerve fiber regeneration was seen in group A. After 8 weeks, the regenerating nerve fibers were significantly more in groups C, D and E than in group B and ingroup E than groups C and D(Plt;0.05). After 12 weeks, the regenerating nervefibers were significantly more in groups C，D and E than in group B(Plt;0.05).Conclusion End-to-side coaptation with artery sleeve anastomosis is a new valuable method in repair of peripheral nerve injuries.
Objective To construct chemically extracted acellular nerve allograft (CEANA) with Schwann cells (SCs) from different tissues and to compare the effect of repairing peripheral nerve defect. Methods Bone marrow mesenchymal stem cells (BMSCs) and adi pose-derived stem cells (ADSCs) were isolated and cultured from 3 4-week-old SD mice with weighing 80-120 g. BMSCs and ADSCs were induced to differentiated MSC (dMSC) and differentiated ADSC (dADSC) in vitro.dMSC and dADSC were identified by p75 protein and gl ial fibrillary acidic protein (GFAP). SCs were isolated and culturedfrom 10 3-day-old SD mice with weighing 6-8 g. CEANA were made from bilateral sciatic nerves of 20 adult Wistar mice with weighing 200-250 g. Forty adult SD mice were made the model of left sciatic nerve defect (15 mm) and divided into 5 groups (n=8 per group) according to CEANA with different sources of SCs: autografting (group A), acellular grafting with SCs (5 × 105) (group B), acellular grafting with dMSCs (5 × 105) (group C), acellular grafting with dADSCs (5 × 105) (group D), and acellular grafting alone (group E). Motor and sensory nerve recovery was assessed by Von Frey and tension of the triceps surae muscle testing 12 weeks after operation. Then wet weight recovery ratio of triceps surae muscles was measured and histomorphometric assessment of nerve grafts was evaluated. Results BMSCs and ADSCs did not express antigens CD34 and CD45, and expressed antigen CD90. BMSCs and ADSC were differentiated into similar morphous of SCs and confirmed by the detection of SCs-specific cellsurface markers. The mean 50% withdrawal threshold in groups A, B, C, D, and E was (13.8 ± 2.3), (15.4 ± 6.5), (16.9 ± 5.3), (16.3 ± 3.5), and (20.0 ± 5.3) g, showing significant difference between group A and group E (P lt; 0.01). The recovery of tension of the triceps surae muscle in groups A, B, C, D, and E was 87.0% ± 9.7%, 70.0% ± 6.6%, 69.0% ± 6.7%, 65.0% ± 9.8%, and 45.0%± 12.1%, showing significant differences between groups A, B, C, D, and group E (P lt; 0.05). No inflammatory reactionexisted around nerve graft. The histological observation indicated that the number of myel inated nerve fiber and the myel in sheath thickness in group E were significantly smaller than that in groups B, C, and D (P lt; 0.01). The fiber diameter of group B was significantly bigger than that of groups C and D (P lt; 0.05) Conclusion CEANA supplementing with dADSC has similar repair effect in peripheral nerve defect to supplementing with dMSC or SCs. dADSC, as an ideal seeding cell in nerve tissue engineering, can be benefit for treatment of peripheral nerve injuries.
Objective To investigate the feasibil ity of establ ishment of physiological micturition reflex arc by simultaneously reconstructing the sensory and the motorial nerve of atonic bladder after spinal cord injury. Methods Eight 1-year-old Beegle male canine were selected, weighing 7-12 kg. The left side was the experimental side, while the right side wasthe control side. Epidural microanastomosis of vertebral canal of the left L7 ventral root to S2 ventral root and L7 dorsal root to S2 dorsal root was performed to reconstruct the sensory and the motorial function of atomic bladder. The right side was used as a control without treatment. The new motor-to-motor, and sensory-to-sensory physiological bladder reflex pathway were establ ished after 12 months of axonal regeneration. Then S1-4 segmental spinal cord was destroyed for preparation of complete paraplegia. The electrophysiological examination and the bladder pressure were detected before and after paraplegia. The canine micturition was observed for 3 months after paraplegia. Nurohistological observation was performed after canine sacrifice. Results Of 8 canine, 7 canine survived. After paraplegia, canines displayed urinary incontinence and frequent micturition at first, nocturnal continence was achieved gradually without frequent micturition after 1 month. Urinary infection at different degrees occurred in 3 canines and was controlled after Norfloxacin was administered orally. The bladder pressure increased to (1.00 ± 0.13) kPa, (0.90 ± 0.12) kPa after trains of stimulation (300 mV, 0.3 ms, 20 Hz, 5 seconds) of S2 dorsal root at the experimental side before and after paraplegia respectively, showing no significant difference (P gt; 0.05). It increased to (1.90 ± 0.10) kPa after the same train of stimulation of S2 dorsal root at control side. There was significant difference between the experimental side and the control side (P lt; 0.01). Single stimulation (300 mV, 0.3 ms) of the S2 dorsal root at the experimental side resulted in evoked potentials recorded from the left S2 ventral root before and after paraplegia. Before and after paraplegia, the ampl itudes of the evoked potentials were (0.68 ± 0.11) mV and (0.60 ± 0.08) mV respectively, showing no significant difference (P gt; 0.05). It was (1.21 ± 0.13) mV while stimulating at the control side. There was significant difference between the experimental side and the control side (P lt; 0.01). Neurofibra of L7 dorsal and ventral root grew into S2 dorsal and ventral root on tissue sl ice under l ight microscope. Conclusion Reconstruction of the bladder physiological micturition reflex arc is feasible by anastomosis of sacral dorsal and ventral root below injured spinal plane with the suprasacral survival dorsal and ventral root above the plane respectively for restoration of atonic bladder after spinal cord injury.
OBJECTIVE: To evaluate the nerve regeneration after implantation of chitin tubes containing nerve growth factor(NGF) in the rabbit facial nerve. METHODS: Bilateral 8 mm defect of superior buccal divisions of the facial nerves were made in 16 New Zealand rabbits. Chitin tubes containing NGF were implanted into the gaps, and autologous nerves were implanted into the right gaps as control. The nerve regeneration was evaluated with electrophysiological and ultrastructural examination after 8 and 16 weeks of operation. RESULTS: Chitin tubes containing NGF successfully induced the nerve regeneration, regularly arranged myelinated and unmyelinated axons could be observed across the 8 mm gaps, and the myelin sheath was thick with clear lamellar structure at 8 weeks after operation, The regenerated nerve fibers increased and were more mature at 16 weeks after operation. There were no significant difference in electrical impulse conduction velocity through the neural regeneration between the experimental and control sides (P gt; 0.05). CONCLUSION: Chitin tubes containing NGF can provide optimal conditions for regeneration of rabbit facial nerve.
Objective To review new progress of related research of peri pheral nerve defect treatment with tissue engineering in recent years. Methods Domestic and internationl l iterature concerning peri pheral nerve defect treatment with tissue engineering was reviewed and analyzed. Results Releasing neurotrophic factors with sustained release technology included molecular biology techniques, poly (lactic-co-glycol ic acid) microspheres, and polyphosphate microspheres. The mixture of neurotrophic factors and ductus was implanted to the neural tube wall which could be degraded then releasing factors slowly. Seed cells which were the major source of active ingredients played an important role in the repair and reconstruction of tissue engineering products. The neural tube of Schwann cells made long nerve repair and the quality of nerve regeneration was improved. Nerve scaffold materials included natural and synthetic biodegradable materials. Tube structure usually was adopted for nerve scaffold, which performance would affect the nerve repair effects directly. Conclusion With the further research of tissue engineering, the treatment of peripheral nerve defects with tissue engineering has made significant progress.