OBJECTIVE: To investigate the protective effect of tumor necrosis factor-alpha(TNF-alpha) on spinal motor neurons after peripheral nerve injury. METHODS: Twenty Wistar rats were divided into two groups, the right sciatic nerves of 20 Wistar rats were transected, the proximal stumps were inserted into a single blind silicone tube. 16 microliters of normal saline(NS) and TNF-alpha(30 U/ml) were injected into the silicone tubes. After 2 weeks, the 4th, 5th lumbar spinal cord were taken for examination. Enzyme histochemical technique and image analysis were used to show acetylcholinesterase(AChE) and nitric oxide synthase(NOS) activity of spinal motor neurons. RESULTS: The number of AChE and NOS staining neurons were 8.65 +/- 1.98 and 5.92 +/- 1.36 in the experimental group and 6.37 +/- 1.42 and 8.67 +/- 1.45 in the control group respectively, there were significant difference between the two groups(P lt; 0.01). CONCLUSION: It suggests that TNF-alpha has protective effect on motor neurons after peripheral nerve injury.
Thiry wistar rats were used and divided in 2 groups. A segment of 6mm was excised in the sciatic nerve which were then bridged with chitin and skelal muscle. at 4,8,12 weeks after operation, In the chitin group a satisfactory regeneration of nerve fibers was evident with electrophysiologic and histologic examinations, and HRP retrogade labelling evaluation. The possible mechanism of enhancing nerve regeneration of chitin was also discussed.
To find new technique for repair of peripheral nerve defect, the nerve elongation repair technique was adopted. Two cases with nerve defect were treated by this method. One was a 12 year old male, the defect length of right radial nerve was 7.2 cm at the elbow. The other one was a 28 year old male, the defect length of left ulnar nerve the was 5 cm at elbow. In this method, the nerve was elongated by slow stretch from distal and proximal end of the ruptured nerve. After a few days, the nerve was repaired by direct suture. After operation, the function of nerves were recovered in 119 days and 114 days respectively. Follow-up for 5 years, the function of the effected limbs were recovered to the normal side. It was concluded that: (1) the peripheral never can be elongated by slow stretch; (2) to stretch the nerve end in a rubber tube can prevent adhesion and connective tissue blocking; (3) strength and supporting point of stretching should be designed carefully.
Objective To comment on the recent advances of production and application of the bio-derived scaffold in the tissue engineered peripheral nerve. Methods The recent articles were systematically analyzed, and then the production methods of the bio-derived scaffold and its application to the tissue engineered peripheral nerve were evaluated and prospected. Results B iological tissues were processed by some methods to produce the bio-derived materials. These mat erials could maintain the structure and components of the tissues. Moreover, the immunogenicity of these materials was reduced. Conclusion Application of the bio-derived materials is a trend in the fabricating scaffold of the tissue en gineered peripheral nerve.
A controversy still exists in the management of nerve injection injury. The results of different timing of operation and methods in treating this type of nerve injury were analysed in limb s function, neuroelectrophysiology and histology. The results showed that the recovery of the injuried nerve in the group of operation, was considerably better than that in the group without operation. In the group of operation early incision of the epineurium with saline irrigation! was superior to late neurolysis. It was suggested that the early incision with saline irrigation could be used as an emergency management for this type of nerve injury.
Objective To study the effect of olfactory ensheathingcells(OECs) transplantation on protecting spinal cord and neurons after peripheral nerve injury. Methods Fifty-five SD rats were randomly divided into blank group (n=5), experimental group (n=25) and control group (n=25). The right sciatic nerves of all the rats were transected. The proximal end was embedded in muscle and treated with OECs (experimental group) and DMEM (control group). No treatment was given to the blank group. The rats were sacrificed 1, 2, 3, 7, and 14 days after the transplantation, the related neurons were observed with histological and TUNEL methods. Results After sciatic nerves were transected, death of neurons occurred in spinal cord and ganglion. One, 2, 3 days after treatment, the neuron survival rate in experimental group was 98.4％±6.5%，97.6％±6.5%，95.2％±6.7% respectively. The neuron survival rate in control group was 97.8％±6.7%，97.4％±6.4%，94.3％±6.8% 1, 2, and 3 days after treatment respectively. There was no significant difference between experimental group and control group. Seven and 14 days after treatment, the neuron survival rate in experimental group was 92.4％±8.9%，87.7％±9.4% respectively. The neuron survival rate in control group was 87.4％±8.6%，83.4％±8.5% 7 and 14 days after treatment respectively. There was significant difference between experimental group and control group. On 1st and 2nd day, no apoptosis was seen in spinal cord anterior horn of the rats in both experimental group and control group. On 3rd, 7th, and 14th day, the apoptosis index of spinal cord anterior horn motoneuron in experimental rats were lower（1.2±0.8，1.4±0.6，4.1±1.3） than that in the control group（2.1±1.1，3.1±1.1，6.1±1.8）（Plt;0.05）. One, 2, and 3 days after the operation, no ganglion neurons apoptosis was observed in all rats. On 7th day the apoptosis index of ganglion neurons in experimental group（2.10±0.32）were lower than thatin control group （4.40±0.56）（Plt;0.05）. On 14th day there was no significant difference in the apoptosis index of ganglion neurons between experimental group （4.30±1.80）and control group（6.70±2.50）(P＜0.05). Conclusion Apoptosis of neurons occur after peripheral nerve injury in spinal cord and ganglion. OECs transplantation is effective in preventing apoptosis.
To observe the effect of percutaneous electrical stimulation on peripheral nerve regeneration, a model was created on the sciatic nerves of 56 rats from either sectioned and followed by direct anastomosis or clamping of the nerve. The indices, such as conducting velocity of nerve, maximal induced action potential of muscle, growth speed of nerve, rateof axon crossing anastomosis site, number of muscular fiber on transverse area and weight of muscle by autocontrol were compared. In this study, 36 rats were divided into two groups, 24 rats in Group 1 and 12 rats in Group 2. In Gourp 1, both sciatic nerves were sectioned and was anastomozed 4 weeks later. One side of the nerve was stimulated with percutaneous electric current, the other side was served as control. In Group 2, both sides of nerves were clamped and the electical stimulationwas carried out on one side. The parameters of the electric current were 2～5HZ, 0.4m/s, 24～48V. The electrophysiological and histomorphological features were observed 1 to 6 weeks after operation. The results showed that in the stimulatedside, the indices were all superior to that of the control side. This suggestedthat electrical stimulation could promote peripheral nerve regeneration.
Objective To observe the revascularization process of chemically extracted acellular allogeneous nerve graft in repairing rat sciatic nerve defect. Methods Eighty adult male SD rats were selected. The sciatic nerve trunks from ischial tuberosity to the ramus of tibiofibular nerve of 16 SD rats were obtained and were prepared into acellular nerve stents by chemical reagent. Sixty-four SD rats were used to prepare the models of sciatic nerve defect (1.0 cm) and thereafter were randomized into two groups (n=32): experimental group in which acellular allogeneous nerve grafts were adopted and control group in which orthotopic transplantation of autologous nerve grafts were adopted. Postoperatively, the general conditions of all rats were observed, and the gross and ALP staining observation were conducted at 5, 7, 10, 14, 21, 28 days and 2, 3 months, respectively. Results All the incisions were healed by first intention. Trail ing status and toe’s dysfunction in extension happened to the right hindl imb of rats in two groups and were improved 6 weeks after operation. General observation showed that the grafts of two groups connected well to the nerves, with appearances similar to that of normal nerve. ALP staining demonstrated that the experimental group had no ingrowth of microvessel but the control group had ingrowth of microvessel 5 days after operation; the experimental group had ingrowth of microvessel but both groups had no microvessel 7 days after operation; few longitudinal microvessel throughout the grafts were observed in both groups 10, 14 and 21 days after operation; no obvious difference in capillary network of grafts was observed between two groups 28 days after operation; and the microvascular architecture of grafts in both groups were similar to that of normal nerve 2 and 3 months after operation. Conclusion When the chemically extracted allogeneous nerve graft is adopted to repair the peripheral nerve defect, new blood microvessels can grow into grafts timely and effectively.
In order to obtain the anatomical basis of transferring the anterior interosseous nerve to repair the injury of thenar or ulnar nerve at the wrist level, ten fresh cadaveric forearms were dissected. The pronator quadratus branch of the median nerve was (1.5 +/- 0.4) mm in diameter with (866 +/- 144) nerve fibers. The recurrent branch of median nerve was (1.7 +/- 0.3) mm in diameter with (1,120 +/- 97) nerve fibers. The deep branch of ulnar nerve was (2.1 +/- 0.4) mm in diameter with (1,318 +/- 120) nerve fibers. To repair the thenar recurrent branch, nerve graft should be used to bridge between the distal end of the anterior interosseous nerve and the origination of the recurrent branch. The deep branch of the ulnar nerve could be repaired by direct suture after being dissected proximally. In patients, the technique was applied to repair 17 cases of injury of thenar branch and 3 cases of injury of deep branch of ulnar nerve. Among them, seventeen cases were followed up from 2 to 7 years. On electromyogram it was normal in 10. The myodynamia was restored in different degree: M2 in 2, M3 in 5, M4 in 7, M5 in 3. The procedure of the operation and the matters needed attention during the operation were discussed.
OBJECTIVE To investigate the effect of the emergent repair of peripheral nerve injury of the wrist. METHODS From July 1993 to December 1997, 17 cases were admitted, which 21 injured peripheral nerves were repaired emergently. Among them, there were 11 cases of median nerve injury, 2 cases of ulnar nerve injury and 4 cases of median and ulnar nerve injury. All the nerves were ruptured completely except one which was partially ruptured. The emergent operation was taken and the injured nerves were repaired by microsurgical technique. RESULTS Followed up 6 to 18 months after operation, 95.25% injured nerves had good outcome. CONCLUSION Because of the specific structure of the wrist, nerve injury at this part need to be repaired emergently. It can enhance the regeneration of the injured nerve, preserve the function of the intrinsic muscle of hand, and decrease the local adhesion.