• Archives of Reconstructive Microsurgery
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• v.6 no.1
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• pp.29-38
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• 1997

A peripheral nerve when approximation of the ends imparts tension at the anastomosis and with a relatively long segment defect after excision of neuroma and neurofibroma cannnot be repaired by early primary suture. The one of the optimistic reconstruction method of severed peripheral nerves is to restore tension-free continuity at the repair site putting an autogenous nerve graft into the neural gap despite of ancipating motor or sensory deficit of the donor nerve area. To overcome the deficit of the autogenous nerve graft, several other conduits supplying a metabolically active environment which is able to support axon regeneration and progression, providing protection against scar invasion, and guiding the regrowing axons to the distal stump of the nerve have been studied. An author have used ipsilateral femoral vein, ipsilateral femoral vein filled with fresh thigh muscle, and autogenous sciatic nerve for the sciatic nerve defect of around 10 mm in length to observe the regeneration pattern in rat by light and electron microscopy. The results were as follows. 1. Light microscopically regeneration pattern of nerve fibers in the autogenous graft group was more abundant than vein graft and vein filled with muscle group. 2. On ultrastructural findings, the proxial end of the graft in various groups showed similar regenerating features of the axons, myelin sheaths, and Schwann cells. The fascicular arrangement of the myelinated and unmyelinated fibers was same regardless of the type of conduits. There were more or less increasing tendency in the number and the diameter of myelinated fibers correlated with the regeneration time. 3. In the middle of the graft, myelinated nerve fibers of vein filled with muscle group were more in number and myelin sheath was thinner than in the venous graft, but the number of regenerating axons in autogenous nerve graft was superior to that in both groups of the graft. The amount of collagen fibrils and amorphous materials in the endoneurial space was increased to elapsed time. 4. There was no difference in regenerating patterns of the nerve fibers of distal end of the graft. The size and shape of the myelinated nerve fbers were more different than that of proximal and middle portion of the graft. From the above results, the degree of myelination and regenerating activity in autogenous nerve is more effective and active in other types of the graft and there were no morphological differences in either ends of the graft regardless of regeneration time.

• Journal of Korean Physical Therapy Science
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• v.14 no.1_4
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• pp.11-23
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• 2007

This study was performed to evaluate the effects of low-intensity ultrasound application to the peripheral nerve injury animal model on enhancement of nerve regeneration and functional recovery. Using aseptic microsurgical techniques, the sciatic nerve of adult male Sprague-Dawley rats was crushed at the outside of right mid-thigh for 30 seconds with fine forceps. Beginning just after surgery, various continuous-wave ultrasound treatments with intensities of 0.2 W/$cm^2$, 0.5 W /$cm^2$ and 1.0 W /$cm^2$ operated at 1 MHz or sham treatment were applied to the opposite inside of the crush site for 1 minute every other day with a transducer moving speed of 2cm/sec. For evaluation of the progress of sciatic nerve regeneration, c-Fos expression in the lumbar spinal cord (L4-5) dorsal horn was investigated. c-fos expression was markedly increased at 1hour after sciatic nerve crush injury, then gradually decreased thereafter. The c-fos expressions were significantly decreased (p<0.05) in all the experimental groups in comparison with the control group until 3days post-crush, and the degrees of decrease were higher in 0.5 W/$cm^2$ and 1 W/$cm^2$ intensity ultrasound application groups. It is suggested that low-intensity ultrasound application to an animal model of sciatic crush injury may suppress pain transmission and promote nerve regeneration, and which may result in delayed progress of muscle atrophy and accelerated progress of muscle recovery and eventually may result in accelerated and improved foot function recovery.

• Journal of Korean Physical Therapy Science
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• v.12 no.4
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• pp.43-55
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• 2005

This study was performed to investigate the effects of low-power Helium Neon Infra Red(He-Ne IR)laser irradiation and exercise on the regeneration of experimentally cut sciatic nerve in rats. The thrity Sprague-Dawley adult mail rats were assigned to the 6 groups : normal group(1), injured control groups(2), experimental groups(3). There was made artificial injured in the sciatic nerve of rats the each experimental laser group and exercise group were treated from 3 days after being injured for the 5 minutes(laser group), 10 minutes(exercise group), and 15 minutes(exercise and laser group) everyday during 2 weeks. There were measured the changes of amplitude of compound muscle action potential and histological change by the light microscopy on the sciatic nerve injured rats. The results obtained as follows : 1. In the control groups, the regeneration were slowly and slightlly progressed to compared with the experimental groups. Inflammation were much more observed, and fibrous adhesion was also observed around the sutured region of the cut sciatic nerve. 2. The amplitude of compound muscle action potential in the experimental groups were significantly increased to the injured control groups at 1 week(p<.05). The compound muscle action potential of the exercise and lased group was significantly decreased to be similar to normal group at 2 weeks(p<.05). 3. In histologic finding, in the experimental groups were observed the proliferation of the schwann cells, the infiltration of inflammatory cells and the extent of destruction at adjacent tissue were remarkably decreased on the 2 weeks. From these experimental results, it may be suggested that the laser and exercise were effected the heeling process of peripheral nerve injuried rats.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.3
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• pp.199-218
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• 2005

Purpose of Study: Peripheral nerve regeneration depends on neurotrophism of distal nerve stump, recovery potential of neuron, supporting cell like Schwann cell and neurotrophic factors such as BDNF. Peripheral nerve regeneration can be enhanced by the conduit which connects the both sides of transected nerve. The conduit maintains the effects of neurotrophism and BDNF produced by Schwann cells which can be made by gene therapy. In this study, we tried to enhance the peripheral nerve regeneration by using calcium phosphate coated porous conduit and BDNF-Adenovirus infected Schwann cells in sciatic nerve of rats. Materials and Methods: Microporous filter which permits the tissue fluid essential for nerve regeneration and does not permit infiltration of fibroblasts, was made into 2mm diameter and 17mm length conduit. Then it was coated with calcium phosphate to improve the Schwann cell adhesion and survival. The coated filter was evaluated by SEM examination and MTT assay. For effective allogenic Schwann cell culture, dorsal root ganglia of 1-day old rat were extracted and treated with enzyme and antimitotic Ara-C. Human BDNF cDNA was obtained from cDNA library and amplified using PCR. BDNF gene was inserted into adenovirus shuttle vector pAACCMVpARS in which E1 was deleted. We infected the BDNF-Ad into 293 human mammary kidney cell-line and obtained the virus plaque 2 days later. RT-PCR was performed to evaluate the secretion of BDNF in infected Schwann cells. To determine the most optimal m.o.i of BDNF-Ad, we infected the Schwann cells with LacZ adenovirus in 1, 20, 50, 75, 100, 250 m.o.i for 2 hours and stained with ${\beta}$-galactosidase. Rats(n=24) weighing around 300g were used. Total 14mm sciatic nerve defect was made and connected with calcium phosphate coated conduits. Schwann cells$(1{\times}10^6)$ or BDNF-Ad infected Schwann cells$(1{\times}10^6)$ were injected in conduit and only media(MEM) was injected in control group. Twelve weeks after surgery, degree of nerve regeneration was evaluated with gait analysis, electrophysiologic measurements and histomorphometric analysis. Results: 1. Microporous Millipore filter was effective conduit which permitted the adhesion of Schwann cells and inhibited the adhesion of fibroblast. We could enhance the Schwann cell adhesion and survival by coating Millipore filter with calcium phosphate. 2. Schwann cell culture technique using repeated treatment of Ara-C and GDNF was established. The mean number of Schwann cells obtained 1 and 2 weeks after the culture were $1.54{\pm}4.0{\times}10^6$ and $9.66{\pm}9.6{\times}10^6$. 3. The mRNA of BDNF in BDNF-Ad infected Schwann cells was detected using RT-PCR. In Schwann cell $0.69\;{\mu}g/{\mu}l$ of DNA was detected and in BDNF-Adenovirus transfected Schwann cell $0.795\;{\mu}g/{\mu}l$ of DNA was detected. The most effective infection concentration was determined by LacZ Adenovirus and 75 m.o.i was found the most optimal. Conclusion: BDNF-Ad transfected Schwann cells successfully regenerated the 14mm nerve gap which was connected with calcium phosphate coated Millipore filter. The BDNF-Ad group showed better results compared with Schwann cells only group and control group in aspect to sciatic function index, electrophysiologic measurements and histomorphometric analysis.

• The Journal of Korean Medicine
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• v.29 no.2
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• pp.133-150
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• 2008

Objective: This study was performed to examine Danggui (DG, Angelica gigas Nakai)'s potential activity for promoting axonal regeneration in the injured peripheral nerve. Methods: Using the sciatic nerve in the rats, DG extract 5 ${\mu}l$(10 mg/ml in 0.5% saline) was dripped into the injury site of the nerve. Results: DG treatment facilitated axonal elongation responses in the distal portion to the injury site. GAP-43 protein levels were upregulated by DG treatment in the injured nerve and also in the DRG, suggesting the induction of GAP-43 expression at gene expression level after nerve injury. Phospho-Erk1/2 protein levels were upregulated in the injured nerve area and also in the DRG, suggesting retrograde transport of phospho-Erk1/2 protein from the injury area to the cell body. Cdc2 protein levels were slightly upregulated by DG treatment. DG treatment increased the number of non-neuronal cells in the distal portion to the injury site. Conclusions: The present data suggest that DG is effective for enhanced axonal regrowth after sciatic nerve injury.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.2
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• pp.148-154
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• 2012

Peripheral nerve injuries in the oral and maxillofacial regions require nerve repairs for the recovery of sensory and/or motor functions. Primary indications for the peripheral nerve grafts are injuries or continuity defects due to trauma, pathologic conditions, ablation surgery, or other diseases, that cannot regain normal functions without surgical interventions, including microneurosurgery. For the autogenous nerve graft, sural nerve and greater auricular nerve are the most common donor nerves in the oral and maxillofacial regions. The sural nerve has been widely used for this purpose, due to the ease of harvest, available nerve graft up to 30 to 40 cm in length, high fascicular density, a width of 1.5 to 3.0 mm, which is similar to that of the trigeminal nerve, and minimal branching and donor sity morbidity. Many different surgical techniques have been designed for the sural nerve harvesting, such as a single longitudinal incision, multiple stair-step incisions, use of nerve extractor or tendon stripper, and endoscopic approach. For a better understanding of the sural nerve graft and in avoiding of uneventful complications during these procedures as an oral and maxillofacial surgeon, the related surgical anatomies with their harvesting tips are summarized in this review article.

• The Journal of Internal Korean Medicine
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• v.33 no.1
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• pp.83-101
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• 2012

Objectives : This study was aimed to investigate the therapeutic effect of Bogijetongtanggammi-bang (BJTG) on injury of the peripheral nerve tissues. Methods : Rats were divided into 2 groups. The rats of the first group were injected with Taxol (1.25 mg/kg) to their sciatic nerves, once each. The sciatic nerves of the rats of the second group were crushed by forcept for 30 seconds. Rats were administered with BJTG (400 mg/kg) or 0.9% saline for 5 days. Changes of DRG neurons, Schwann cells, Cdc2, caspase 3. phospho-p44/42 Erk1/2, phospho-vimentin and ${\beta}1$ integrin were observed by fluorescent microscope and analysed in western blot. Results : In Taxol-treated SD rat models, BJTG up-regulated neurite outgrowth, Schwann cells, Cdc2 and phospho-Erk1/2, and down-regulated caspase 3. In pressure-injured rat models, BJTG up-regulated axons of sciatic nerve, Schwann cells, Cdc2, phospho-vimentin, ${\beta}1$ integrin, and down-regulated caspase 3. Conclusions : Taken together, BJTG was promotive of nerve regeneration on SNI as well as Taxol-induced nerve injury. BJTG had a pharmaceutical property enhancing recovery of injured peripheral nerves and could be a candidate for drug development after further research.

• Archives of Plastic Surgery
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• v.37 no.2
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• pp.105-109
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• 2010

Purpose: The purpose of this study is to determine the effect of platelet-rich plasma (PRP) on rat sciatic nerve regeneration in a 10 mm silicone chamber. Methods: A total of 6 inbred Lewis rats were used in this study. Bilateral sciatic neurectomy was performed on each rat. On one side, silicone chambers containing PRP solutions were implanted; on the contralateral side, the chambers without PRP were implanted as a control. In 12 weeks post-implantation, chambers were retrieved and both gastrocnemius muscles were excised. Nerves biopsy samples were examined under a light microscope after Masson trichrome staining. Results: Cross sections of the midpoints of PRP treated nerves were significantly larger and appeared more mature than those of controls. Conclusion: Based on morphological evidence, PRP has a positive effect on neural regeneration, and it may therefore be useful for treating peripheral nerve injuries.

• Archives of Reconstructive Microsurgery
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• v.12 no.1
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• pp.1-12
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• 2003

The bridging of nerve gaps is still one of the major problems in peripheral nerve surgery. To evaluate the role of silicon tube in nerve regeneration, gaps were made by resection of tibial components of sciatic nerves of twenty-five New Zealand rabbits. The gaps were divided into five groups. In group I, the tibial components of sciatic nerves were isolated and the incision immediately closed. In group II, 1-cm segments of the nerve were removed and the silicon tubes filled with autogenous skeletal muscle were sutured in place. In group III, 1-cm segments of the nerve were removed and the silicon tubes filled without muscle were sutured in place. In group IV, 2-cm segments of the nerve were removed and the silicon tubes filled with autogenous skeletal muscle were sutured in place. In group V, 2-cm segments of the nerve were removed and the silicon tubes filled without muscle were sutured in place. At 16th week, the eletromyography, the light and transmission electron microscopy were performed. Nerve conduction study stimulating sciatic nerve proximal to the lesion and recording at gastrocnemius muscle showed that the compound muscle action potentials of the group II with 1 cm nerve defect filled with muscle were higher amplitudes than the group III without muscle. Compound muscle action potentials of the group IV with 2 cm defect filled with muscle showed similar results in comparison with the group V. The light and transmission electron microscpy showed that a good morphological pattern of nerve regeneration in 1 cm gap than 2 cm and in gap with muscle than gap without muscle.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.5
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• pp.446-456
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• 2005

Nerve growth factor(NGF) has a critical role in peripheral nerve regeneration. The aim of this study is to construct a well-functioning hNGF-$\beta$ recombinat adenovirus for the ultimate development of improved method to promote peripheral nerve regeneration with adenovirus mediated hNGF-$\beta$ gene transfection into Schwann cells. First PCR associated cloning of GFP-tagged hNGF-$\beta$ which was ligated into E1/E3 deleted adenoviral vector was performed and tranfected into E. coli to construct hNGF-$\beta$ recombinant adenovirus. After production of recombinat adenovirus in a large scale, its transfection efficiency, expression, and function were evaluated using cell lines or primarily cultured cells of HEK293 cells, Schwann cells, fibroblast(NIH3T3) and myocyte(CRH cells). GFP expression was observed in 90% of infected cells compared to uninfected cells. Total mRNA isolated from hNGF-$\beta$ recombinat adenoviru infected cells showed strong RT-PCR band, however, LacZ recombinant adenovirus infected or uninfected cells did not. NGF quantification by ELISA showed a maximal release of 18.865 +/- 0.31ng/mL at 4th day. PC-12 cells exposed to media with hNGF-$\beta$ recombinant adenovirus infected Schwann cell demonstrated higher levels of differentiation compared with controls. We generated hNGF-$\beta$ recombinant adenovirus and induced over expression of NGF successfully in nonneuronal and neuronal cells. Following these result, it is expected to develop an improved treatment strategy peripheral nerve regeneration using the hNGF-$\beta$ gene transfected cells.