• Applied Microscopy
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• 제32권1호
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• pp.1-8
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• 2002

손상된 말초신경이 정상상태로 회복되는데 침이 어떤 영향을 미치는지 확인하기 위하여 좌골신경을 인위적으로 손상시킨 후 침을 처리한 군 (AG)과 자연적으로 치유된 군 (CG)의 좌골신경내의 유발전위 증가율, 척수내 효소활성도의 변화 및 좌골신경의 미세구조를 비교.관찰하였다. 유발전위 증가율은 CG에서보다 AG에서 높았고, acid phosphatase 활성도는 1CG와 2AG에서 높게 나타났으나 시간이 경과함에 따라 정상상태로 회복되는 경향을 보였다. 손상된 좌골신경의 미세구조적 변화는 CG보다 AG에서 높은 회복율을 나타내었으며 단지 AG에서만 좌골신경 주위에 지방조직이 발달되어있는 것이 관찰되었다. 이상과 같이 손상된 말초신경이 정상상태로 회복되는 속도는 전자침을 처리한 군에서 높았으며, 특히 다른 치료기간보다 초기시기에서 침의 효과가 매우 높다는 것이 확인되었다.

• 혜화의학회지
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• 제15권2호
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• pp.181-186
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• 2006

Peripheral axons in vertebrate animals can regenerate after nerve injury and accomplish its functional recovery. Numerous studies have revealed that diverse molecular factors are induced during axonal regeneration and their potential roles in axonal regeneration have been studied. Examples is N-CAM, L1, P0, nerve growth factors, GAP-43 and so forth. However, most of the studies on axonal regeneration have been primarily focused on axon fiber regrowth and elucidating molecular factors, and relatively less is known about functional recovery. Also, specific drugs or drug components used in the oriental medicine in relation to nerve fiber regeneration have not been known. And thus, in the present, a study on the effect of Yukmijihwang-tang components and Yukmijihwang-tang extracts to regeneration of peripheral axon fiber is underway by immunofluorescence staining. Therefore, this prior application of Yukmijihwang-tang with documents consideration is reported with a plea for further investigation.

• Archives of Reconstructive Microsurgery
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• 제10권1호
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• pp.12-17
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• 2001

Recovery of nerve injury is conditioned by various factors including physical state, injured site, cause of injury, and neurorrhaphy Many researchers have reported on regeneration of nerve using end to side neurorrhaphy. The purpose of this study was to examine regeneration of nerve in various conditioned side to side neurorrhaphy. Total of 25 male Sprague-Dawley rats weighing 220 to 250 gm were divided into five groups of five rats each. The group 1, sham group, composed of dissection only without nerve transaction. The group 2, control group, composed of nerve division only without neurorrhaphy or sural nerve graft. The group 3 composed of one segmental sural nerve graft between the tibial and peroneal nerve after division. Group 4 had two segment graft, and the group 5 with three segment graft, each segment being 6mm long and 5 mm apart. The side to side neurorrhaphy was performed between peroneal nerve and tibial nerve using segmental sural nerve graft in rats. We exposed the sciatic nerve, tibial nerve, peroneal nerve, and sural nerve on left side with prone position. The peroneal nerve was cut on the bifurcation site from tibial nerve and the side to side epineurial neurorrhaphy was performed between peroneal nerve and tibial nerve through 6 mm sural nerve segment graft with 11-0 nylon under operating microscope. The electromyography and the weight from ipsilateral tibialis anterior muscle was performed at one month after neurorrhaphy Peroneal and tibial nerve was examined at distal and proximal to the neurorrhaphy site by methylene blue stain under light microscope for histologic appearance. The number of nerve fibers were counted using the image analyzer. Statistically, both in electromyography and number of nerve fibers, the differences in values between the groups were significant.

• The Korean Journal of Pain
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• 제29권1호
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• pp.3-11
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• 2016

A nerve block is an effective tool for diagnostic and therapeutic methods. If a diagnostic nerve block is successful for pain relief and the subsequent therapeutic nerve block is effective for only a limited duration, the next step that should be considered is a nerve ablation or modulation. The nerve ablation causes iatrogenic neural degeneration aiming only for sensory or sympathetic denervation without motor deficits. Nerve ablation produces the interruption of axonal continuity, degeneration of nerve fibers distal to the lesion (Wallerian degeneration), and the eventual death of axotomized neurons. The nerve ablation methods currently available for resection/removal of innervation are performed by either chemical or thermal ablation. Meanwhile, the nerve modulation method for interruption of innervation is performed using an electromagnetic field of pulsed radiofrequency. According to Sunderland's classification, it is first and foremost suggested that current neural ablations produce third degree peripheral nerve injury (PNI) to the myelin, axon, and endoneurium without any disruption of the fascicular arrangement, perineurium, and epineurium. The merit of Sunderland's third degree PNI is to produce a reversible injury. However, its shortcoming is the recurrence of pain and the necessity of repeated ablative procedures. The molecular mechanisms related to axonal regeneration after injury include cross-talk between axons and glial cells, neurotrophic factors, extracellular matrix molecules, and their receptors. It is essential to establish a safe, long-standing denervation method without any complications in future practices based on the mechanisms of nerve degeneration as well as following regeneration.

• Journal of Dental Anesthesia and Pain Medicine
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• 제17권3호
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• pp.191-198
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• 2017

Background: For peripheral nerve regeneration, recent attentions have been paid to the nerve conduits made by tissue-engineering technique. Three major elements of tissue-engineering are cells, molecules, and scaffolds. Method: In this study, the attachments of nerve cells, including Schwann cells, on the nerve conduit and the effects of both growth factor and adhesion molecule on these attachments were investigated. Results: The attachment of rapidly-proliferating cells, C6 cells and HS683 cells, on nerve conduit was better than that of slowly-proliferating cells, PC12 cells and Schwann cells, however, the treatment of nerve growth factor improved the attachment of slowly-proliferating cells. In addition, the attachment of Schwann cells on nerve conduit coated with fibronectin was as good as that of Schwann cells treated with glial cell line-derived neurotrophic factor (GDNF). Conclusion: Growth factor changes nerve cell morphology and affects cell cycle time. And nerve growth factor or fibronectin treatment is indispensable for Schwann cell to be used for implantation in artificial nerve conduits.

• Molecules and Cells
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• 제40권1호
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• pp.10-16
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• 2017

When peripheral axons are damaged, neuronal injury signaling pathways induce transcriptional changes that support axon regeneration and consequent functional recovery. The recent development of bioinformatics techniques has allowed for the identification of many of the regeneration-associated genes that are regulated by neural injury, yet it remains unclear how global changes in transcriptome are coordinated. In this article, we review recent studies on the epigenetic mechanisms orchestrating changes in gene expression in response to nerve injury. We highlight the importance of epigenetic mechanisms in discriminating efficient axon regeneration in the peripheral nervous system and very limited axon regrowth in the central nervous system and discuss the therapeutic potential of targeting epigenetic regulators to improve neural recovery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권1호
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• pp.1-16
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• 2004

The use of artificial nerve conduit containing viable Schwann cells is one of the most promising strategies to repair the peripheral nerve injury. To fabricate an effective nerve conduit whose microstructure and internal environment are more favorable in the nerve regeneration than existing ones, a new three-dimensional Schwann cell culture technique using $Matrigel^{(R)}$. and dorsal root ganglion (DRG) was developed. Nerve conduit of three-dimensionally arranged Schwann cells was fabricated using direct seeding of freshly harvested DRG into a $Matrigel^{(R)}$ filled silicone tube (I.D. 1.98 mm, 14 mm length) and in vitro rafting culture for 2 weeks. The nerve regeneration efficacy of three-dimensionally cultured Schwann cell conduit (3D conduit group, n=6) was assessed using SD rat sciatic nerve defect of 10 mm, and compared with that of silicone conduit filled with $Matrigel^{(R)}$ and Schwann cells prepared from the conventional plain culture method (2D conduit group, n=6). After 12 weeks, sciatic function was evaluated with sciatic function index (SFI) and gait analysis, and histomorphology of nerve conduit and the innervated tissues of sciatic nerve were examined using image analyzer and electromicroscopic methods. The SFI and ankle stance angle (ASA) in the functional evaluation were $-60.1{\pm}13.9$, $37.9^{\circ}{\pm}5.4^{\circ}$ in 3D conduit group (n=5) and $-87.0{\pm}12.9$, $32.2^{\circ}{\pm}4.8^{\circ}$ in 2D conduit group (n=4), respectively. And the myelinated axon was $44.91%{\pm}0.13%$ in 3D conduit group and $13.05%{\pm}1.95%$ in 2D conduit group to the sham group. In the TEM study, 3D conduit group showed more abundant myelinated nerve fibers with well organized and thickened extracellular collagen than 2D conduit group, and gastrocnemius muscle and biceps femoris tendon in 3D conduit group were less atrophied and showed decreased fibrosis with less fatty infiltration than 2D conduit group. In conclusion, new three-dimensional Schwann cell culture technique was established, and nerve conduit fabricated using this technique showed much improved nerve regeneration capacity than the silicone tube filled with $Matrigel^{(R)}$ and Schwann cells prepared from the conventional plain culture method.

• Journal of Korean Neurosurgical Society
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• 제58권6호
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• pp.504-507
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• 2015

Objective : Our aim was to evaluate the histopathological effects of tissue adhesives on peripheral nerve regeneration after experimental sciatic nerve transection in rats and to search whether these tissue adhesives may possess a therapeutic potential in peripheral nerve injuries. Methods : This experimental study was performed using 42 female Wistar-Albino rats distributed in 6 groups subsequent to transection of right sciatic nerves. Group I underwent external circumferential neurolysis; Group II received suture repair; Group III had local polymeric hydrogel based tissue adhesive administration; Group IV received suture repair and polymeric hydrogel based tissue adhesive application together; Group V had gelatin based tissue adhesive application and Group VI had suture repair and gelatin based tissue adhesive together. After a 6-week follow-up period, biopsies were obtained from site of neural injury and groups were compared with respect to histopathological scoring based on inflammatory, degenerative, necrotic and fibrotic changes. Results : There were remarkable differences between control group and study groups with respect to inflammation (p=0.001), degeneration (p=0.002), necrosis (p=0.007), fibrosis (p<0.001) and vascularity (p=0.001). Histopathological scores were similar between study groups and the only noteworthy difference was that Group V displayed a lower score for necrosis and higher score in terms of vascularization. Conclusion : Our results imply that tissue adhesives can be useful in repair of peripheral nerve injuries by decreasing the surgical trauma and shortening the duration of intervention. Results with gelatin based tissue adhesive are especially promising since more intense vascularity was observed in tissue after application. However, trials on larger series with longer durations of follow-up are essential for reaching more reliable conclusions.

• 국제물리치료학회지
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• 제3권1호
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• pp.345-355
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• 2012

This study purposed to examine the effect of low power laser on pain response and axonal regeneration. In order to prepare peripheral nerve injury models, we crushed the sciatic nerve of Sprague-Dawley rats and treated them with low power laser for 21 days. The rats were divided into 4 groups: normal group(n=10); control group(n=10) without any treatment after the induction of sciatic nerve crush injury; experimental group I(n=10) treated with low power laser(0.21$mJ/mm^2$) after the induction of sciatic nerve crush injury; and experimental group II(n=10) treated with low power laser(5.25$mJ/mm^2$) after the induction of sciatic nerve crush injury. We measured spontaneous pain behavior(paw withdrawal latency test) and mechanical allodynia(von Frey filament test) for evaluating pain behavioral response, and measured the sciatic function index for evaluating the functional recovery of peripheral nerve before the induction of sciatic nerve crush injury and on day 1, 7, 14 and 21 after the induction. After the experiment was completed, changes in the H & E stain and toluidine blue stain were examined histopathologically, and changes in MAG(myelin associated glycoprotein) and c-fos were examined immunohistologically. According to the results of this study, when low power laser was applied to rat models with sciatic nerve crush injury for 21 days and the results were examined through pain behavior evaluation and neurobehavioral, histopathological and immunohistological analyses, low power laser was found to affect pain response and axonal regeneration in both experimental group I and experimental group II. Moreover, the effect on pain response and axonal regeneration was more positive in experimental group I to which output 0.21$mJ/mm^2$ was applied than in experimental group II to which 5.25$mJ/mm^2$ was applied.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제17권4호
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• pp.317-330
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• 1995

The purpose of this study is to observe the stimulant effect of the isolated nerve segment on the peripheral nerve regeneration using silicone tube in rats. Sprague-Dawley female albino rats were used as experimental animals and nerve defects were made by resection of 14 mm-long segment of right sciatic nerves. In control group, the defects were bridged with the silicone tubes. In experimental group, the defects were bridged with the same manner and additionally, 2mm-long nerve segments were inserted at the center of the silicone tubes. 3 months later, the regenerated nerve tissue within the silicone tubes were examined by histologic study. Axonal diameters and numbers of axons were measured and all data were analyzed by using SAS package program. The results obtained were as follows : 1. The experimental group was increased than the control group in general diameters of the regenerated nerve fiber.(P<0.05) 2. The diameters of axons were increased in the experimental group compare to the control group.(P<0.05) 3. The numbers of axons were increased in the experimental group compare to the control group.(P<0.05)