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 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.
Objective To summarize the research progress of anterior cutaneous nerve injury and repair in knee arthroplasty. Methods The relevant literature at home and abroad in recent years was reviewed and summarized from the anatomy of anterior cutaneous nerve, nerve injury grade, clinical manifestations, prevention and treatment of anterior cutaneous nerve. Results The anterior cutaneous nerve injury is a common complication of knee arthroplasty. Because the anterior cutaneous nerve branches are many and thin, and mainly run between the first and second layers of fascia, this level is often ignored during surgical exposure. In addition, the knee arthroplasty does not routinely perform the exploration and repair of the cutaneous nerve. So the anterior cutaneous nerve injury is difficult to avoid, and can lead to postoperative skin numbness and knee pain. At present, studies have explored the feasibility of preventing its occurrence from the aspects of improved incision and intraoperative separation of protective nerve. There is no effective prevention and treatment measures for this complication. For patients with skin numbness after knee arthroplasty, the effectiveness of drug treatment is not clear. Local nerve block or nerve excision can be used to treat patients with painful symptoms after knee arthroplasty considering cutaneous pseudoneuroma. ConclusionKnee arthroplasty is widely used and anterior cutaneous nerve injury is common in clinic. In the future, more high-quality clinical studies are needed to further explore the prevention and treatment measures of this complication and evaluate the clinical benefits obtained.
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 Following the delayed repair of peripheral nerve injury, the cell number of anterior horn of the spinal cord and its ultrastructural changes, motorneuron and its electrophysiological changes were investigated. METHODS In 16 rabbits the common peroneal nerves of both sides being transected one year later were divided into four groups randomly: the degeneration group and regeneration of 1, 3 and 5 months groups. Another 4 rabbits were used for control. All transected common peroneal nerves underwent epineural suture except for the degeneration group the electrophysiological examination was carried out at 1, 3 and 5 months postoperatively. Retrograde labelling of the anterior horn cells was demonstrated and the cells were observed under light and electronmicroscope. RESULTS 1. The number of labelled anterior horn cell in the spinal cord was 45% of the normal population after denervation for one year (P lt; 0.01). The number of labelled cells increased steadily from 48% to 57% and 68% of normal values at 1, 3 and 5 months following delayed nerve repair (P lt; 0.01). 2. The ultrastructure of the anterior horn cells of the recover gradually after repair. 3. With the progress of regeneration the latency become shortened, the conduction velocity was increased, the amplitude of action potential was increased. CONCLUSION Following delayed repair of injury of peripheral nerve, the morphology of anterior horn cells of spinal cord and electrophysiological display all revealed evidence of regeneration, thus the late repair of injury of peripheral nerve was valid.
Objective To investigate the feasibility of the anastomosis of the anterior branch of obturator nerve and the muscular branch of femoral nerve. Methods Five fresh frozen cadavers, including 3 males and 2 females, were included. Both of the obturator nerve, femoral nerve and their branches were dissected, then their routes and anatomical positions were observed. The diameter and the number of myelinated nerve fiber of the anterior branch of obturator nerve and femoral nerve muscular branches were measured, as well as the overlap distance between them. Results The diameter of myelinated nerve fiber of the anterior branch of obturator nerve was (3.80±1.22) mm; the number of myelinated nerve fiber was 11 358±800. The diameters of the rectus femoris branch and the medial femoral branch were (1.60±0.54) mm and (2.20±0.66) mm, respectively; the number of myelinated nerve fiber were 4 961±655 and 6 666±466. Both the diameter and number of myelinated nerve fiber were close to the anterior branch of obturator nerve. The anterior branch of obturator nerve could be directly anastomosed with each nerve branch of femoral nerve in nontension, and the overlap distance was about 30 mm. Conclusion It is feasible to repair the femoral nerve by transposed the anterior branch of obturator nerve and anastomosed with the femoral nerve muscular branches. And the rectus femoris branch and the medial femoral branch should be taken as the recipient nerve.
ObjectiveTo review and analyze the long-term results of delayed repair of median nerve injury. MethodsBetween January 2004 and December 2008, 228 patients with median nerve injury undergoing delayed repair were followed up for more than 4 years, and the clinical data were retrospectively analyzed. There were 176 males (77.19%) and 52 females (22.81%), aged 2-71 years (median, 29 years). The main injury reason was cutting injury in 159 cases (69.74%);203 cases had open injury (89.04%). According to the injury level, injury located at area I (upper arm) in 38 cases (16.67%), at area II (elbow and proximal forearm) in 53 cases (23.25%), at area III (anterior interosseous nerve) in 13 cases (5.70%), and at area IV (distal forearm to wrist) in 124 cases (54.39%). The delayed operations included delayed suture (50 cases, 21.93%), nerve release (149 cases, 65.35%), and nerve graft (29 cases, 12.72%). ResultsFor patients with injury at area I and area II, the results were good in 23 cases (25.27%), fair in 56 cases (61.54%), and poor in 12 cases (13.18%) according to modified Birch and Raji’s median nerve grading system;there was significant difference in the results between 3 repair methods for injury at area II (χ2=6.228, P=0.044), but no significant difference was found for injury at area I (χ2=2.241, P=0.326). Twelve patients (13.18%) needed musculus flexor functional reconstruction. Recovery of thenar muscle was poor in all patients, but only 5 cases (5.49%) received reconstruction. Thirteen cases of nerve injury at area III had good results, regardless of the repair methods. For patients with injury at area IV, the results were excellent in 6 cases (4.84%), good in 22 cases (17.74%), fair in 72 cases (58.06%), and poor in 24 cases (19.35%) according to Birch and Raji’s grading system;there was significant difference in the results between 3 repair methods (χ2=12.646, P=0.002), and the result of delayed repair was better. ConclusionThe results of delayed repair is poor for all median nerve injuries, especially for high level injury. The technique of repair methods vary with injury level. For some delayed median nerve injuries, early nerve transfer may be a better choice for indicative patients.
Objective To provide anatomy evidence of the simple injury of the deep branch of the unlar nerve for cl inical diagnosis and treatments. Methods Fifteen fresh samples of voluntary intact amputated forearms with no deformity were observed anatomically, which were mutilated from the distal end of forearm. The midpoint of the forth palm fingerweb wasdefined as dot A , the midpoint of the hook of the hamate bone as dot B, the ulnar margin of the flexor digitorum superficial is of the l ittle finger as OD, and the superficial branch of the unlar nerve and the forth common finger digital nerve as OE, dot O was the vertex of the triangle, dot C was intersection point of a vertical l ine passing dot B toward OE; dot F was the intersection point of CB’s extension l ine and OD. OCF formed a triangle. OCF and the deep branch of the unlar nerve were observed. From May 2000 to June 2007, 3 cases were treated which were all simple injury of the deep branch of the unlar nerve by glass, diagnosed through anatomical observations. The wounds were all located in the hypothenar muscles, and passed through the distal end of the hamate bone. Muscle power controlled by the unlar nerve got lower. The double ends was sewed up in 2 cases directly intra operation, and the superficial branch of radial nerve grafted freely in the other 1 case. Results The distance between dot B and dot O was (19.20 ± 1.30) mm. The length of BC was (7.80 ± 1.35) mm. The morpha of OCF was various, and the route of profundus nervi ulnaris was various in OCF. OCF contains opponens canales mainly. The muscle branch of the hypothenar muscles all send out in front of the opponens canales. The wounds of these 3 cases were all located at the distal end of the hook of the hamate bone, intrinsic muscles controlled by the unlar nerve except hypothenar muscles were restricted without sensory disorder or any other injuries. Three cases were followed up for 2 months to 4 years. Postoperation, the symptoms disappeared, holding power got well, patients’ fingers were nimble. According to the trial standard of the function of the upper l imb peripheral nerve establ ished by Chinese Medieal Surgery of the Hand Association, the synthetical evaluations were excellent.Conclusion Simple injuries of the deep branch of the unlar nerve are all located in OCF; it is not easy to be diagnosed at the early time because of the l ittle wounds, the function of the hypothenar muscles in existence and the normal sense .
Objective To explore effects of several immunosuppressants on cytokine expressions after repair for a sciatic nerve injury in a rat model. Methods The sciatic nerves of 42 rats were cut and suturedend to end. After operation, the rats were divided into 6 groups. Group A(n=9) was served as a control with no medicines given. Group B (n=9) was given methylprednisolone 20 mg/(kg·d) for 2 days. Groups C(n=9) and D(n=3) were given FK506 1 mg/(kg·d) for 2 weeks and 4 weeks respectively, and were given the same doses of methylprednisolone as Group B. Groups E and F were given CsA 2 mg/(kg·d) for 2 weeks and 4 weeks respectively, and were given the same doses of methylprednisolone as Group B. The sciaticnerves were sampled at 1, 2 and 4 weeks postoperatively. And immuneohistochemistry stainings of interleukin 1β(IL-1β)， tumor necrosis factor α(TNF-α), interferon γ(IFN-γ) and macrophage migration inhibitory factor(MIF) were performed. The staining results were compared and analyzed. Results The expression peaks of IL-1β and IFN-γ were found at the 1st week postoperatively in Group A. Then, the expression decreased rapidly at the 2nd week and disappeared at the 4th week. As for TNF-α and MIF, they were only found to have a low expression until the 1st week in Group A. In groups C-F, the expression peaks of IL-1β, TNF-α and IFN-γ were found at the 2nd week, while the expression peak of MIF was still at the 1st week, and the expression of all the cytokines extended to the 4th week. The expressions of these cytokines in Group B were just between the expression levels of Group A and Groups C-F. Conclusion Immunosuppressants can delay the expression peaks and significantly extend the expression time of IL-1β, TNF-α, IFN-γ and MIF after repair for a sciatic nerve injury in a rat model.
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.