• Proceedings of the Korean Society of Toxicology Conference
• /
• 2002.05a
• /
• pp.14-23
• /
• 2002

The nervous system consists of two types of cells, which are neurons and glial cells. Among the glial cells, oligodendrodendrocytes and schwann cells form myelin sheaths in the central nervous system (CNS) and the peripheral nervous system (PNS), respectively. The major function of myelin in vertebrates is to insulate axonal and help action potential travel faster.(omitted)

• The Korean Journal of Pain
• /
• v.35 no.2
• /
• pp.160-172
• /
• 2022

Background: The authors established an in vitro model of diabetic neuropathy based on the culture system of primary neurons and Schwann cells (SCs) to mimic similar symptoms observed in in vivo models of this complication, such as impaired neurite extension and impaired myelination. The model was then utilized to investigate the effects of insulin on enhancing neurite extension and myelination of diabetic neurons. Methods: SCs and primary neurons were cultured under conditions mimicking hyperglycemia prepared by adding glucose to the basal culture medium. In a single culture, the proliferation and maturation of SCs and the neurite extension of neurons were evaluated. In a co-culture, the percentage of myelination of diabetic neurons was investigated. Insulin at different concentrations was supplemented to culture media to examine its effects on neurite extension and myelination. Results: The cells showed similar symptoms observed in in vivo models of this complication. In a single culture, hyperglycemia attenuated the proliferation and maturation of SCs, induced apoptosis, and impaired neurite extension of both sensory and motor neurons. In a co-culture of SCs and neurons, the percentage of myelinated neurites in the hyperglycemia-treated group was significantly lower than that in the control group. This impaired neurite extension and myelination was reversed by the introduction of insulin to the hyperglycemic culture media. Conclusions: Insulin may be a potential candidate for improving diabetic neuropathy. Insulin can function as a neurotrophic factor to support both neurons and SCs. Further research is needed to discover the potential of insulin in improving diabetic neuropathy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.29 no.3
• /
• pp.151-156
• /
• 2003

This study was performed to develop a useful nerve conduit which provides favorable environment for Schwann cell viability and proliferation. Milipore membrane of $0.45{\mu}m$ pore size was selected because it permits nutritional inflow from the outside of the conduit and prevents from invading the fibrotic tissue into the conduit. The membrane was rolled and sealed to form a conduit of 2mm diameter and 20mm length. To improve the axonal regeneration and to render better environment for endogenous and exogenous Schwann cell behaviour, the microgeometry and surface of conduit was modified by coating with thin film of calcium phosphate. Cellular viability within the conduit and attachment to its wall were assessed with MTT assay and SEM study. Milipore filter conduit showed significantly higher rate of Schwann cell attachment and viability than the culture dish. However, the reverse was true in case of fibroblast. Coating with thin film of low crystalline calcium phosphate made more favorable environment for both cells with minimal change of pore size. These findings means the porous calcium phosphate coated milipore nerve conduit can provide much favorable environment for endogenous Schwann cell proliferation and exogenous ones, which are filled within the conduit for the more advanced strategy of peripheral nerve regeneration, with potential of reducing fibrotic tissue production.

• The Journal of Internal Korean Medicine
• /
• v.33 no.2
• /
• pp.126-144
• /
• 2012

Background : Peripheral nerves more rapidly recover than central nerves. However, it has been known that the degree of reaction of axons of peripheral nerves is affected by distinctive characteristics of axons and environmental factors near the axons. Taxol is a widely used medicine as for ovarian, breast, lung and gastric cancer. However it causes patients difficulties under treatment due to its toxic and side effects, which include persistent pain. Objectives : This study reviewed how SJT extract in vitro and in vivo affects nerve tissues of a sciatic nerve damaged by Taxol. It also studied how SJT extract in vivo affects axons of the sciatic nerve after the sciatic nerve was damaged by pressing. Methods : After vehicle, Taxol, and Taxol plus SJT were treated respectively for tissue of the sciatic nerve in vitro and then tissues were observed using Neurofilament 200, Hoechst, ${\beta}$-tubulin, $S100{\beta}$, caspase-3 and anti-cdc2. SJT was also oral medicated by injecting Taxol into the sciatic nerve of in vivo rats. Tissues of the sciatic nerve and axons of DRG sensory nerves were then observed using Neurofilament 200, Hoechst, ${\beta}$-tubulin, $S100{\beta}$, caspase-3 and p-Erk1/2. After inflicting pressing damage to the sciatic nerve of in vivo rats, tissues of the sciatic nerve and DRG sensory nerve were observed using Neurofilament 200, Hoechst, $S100{\beta}$, caspase-3, anti-cdc2, phospho-vimentin, ${\beta}1$-integrin, Dil reverse tracking and p-Erk1/2. Results : The group of in vitro Taxol plus SJT treatment had meaningful effects after sciatic nerve tissue was damaged by Taxol. The group of in vivo SJT treatment had effects of regenerating Schwann cells and axons which were damaged by Taxol treatment. The group of in vivo SJT had effects of regenerating axons in damaged areas after the sciatic nerve was damaged by pressing, and also had variations of distribution in Schwann cells at DRG sensory nerves and axons. Conclusions : This study confirmed that SJT treatment is effective for growth of axons in the sciatic nerve tissues and improvement of Schwann cells after axons of the sciatic nerve tissues was damaged. After tissues of sciatic nerve was damaged by pressing in vivo, SJT treatment had effects on promoting regeneration of axon in the damaged area and reactional capabilities in axons of DRG sensory nerves.

• Journal of Chest Surgery
• /
• v.37 no.12
• /
• pp.1036-1039
• /
• 2004

Most tumors of the tracheobronchial tree are malignant, and benign tumors are less than 10%. Especially, the incidence of primary neurogenic tumors of the lung has been estimated to be less than 2 percent of primary lung cancer, and majority of these tumors are originated from Schwann cells. These tumors can be presented either as a solitary benign neoplasm or as a malignant form, which is rare. We present two cases of bronchial Schwan noma managed by means of lobectomy.

• Journal of Chest Surgery
• /
• v.31 no.1
• /
• pp.82-85
• /
• 1998

Benign tumors of the trachea are rare and are usually misdiagnosed as bronchial asthma because of the similarity of the symptoms and signs. Although the prognosis of neurofibroma which originats from Schwann cells is good, it may recur or undergo malignant change, so segmental resection of the trachea is recommended. Recently, we experienced a case of primary neurofibroma of the trachea treated successfully by segmental resection of the trachea and end-to-end anastomosis. We report it with a brief review of literatures.

• Korean Journal of Head & Neck Oncology
• /
• v.19 no.2
• /
• pp.188-191
• /
• 2003

Schwannoma is a benign tumor of Schwann cell origin and may occur on any nerve covered by Schwann cells. Although approximately 25% to 48% of all Schwannoma occur in the head and neck region, the lesions originating from the cervical vagus nerve are extremely rare. We have recently experienced a case of huge Schwannoma arising from the cervical vagus nerve which was initially misdiagnosed as a huge goiter. We report herein the case with review of the literatures.

• Korean Journal of Head & Neck Oncology
• /
• v.25 no.1
• /
• pp.33-35
• /
• 2009

Purpose : Granular cell tumour(GCT) is a rare benign tumour that can arise in anywhere throughout the body. Histopathological diagnosis of malignancy is difficult. We report a case of a granular cell tumor which developed on lower lip. Methods : A 58-year-old male had a palpable mass and whitish plaque in the oral mucosa for three months. Results : Under local anasthesia, the tumor was removed through wide excision including normal skin margin. Immediate reconstruction using local flap was done. Pathologic observation showed nests of polygonal cells with abundant granular, eosinophilic cytoplasm and round nuclei. Immunohistopathologic staining showed positive reaction on S-100 protein Conclusion : The results support the hypothesis that granular cell tumor is derived from Schwann cells. We report here on a case of granular cell tumor of lower lip that was successfully treated with radical resection.

• Archives of Craniofacial Surgery
• /
• v.19 no.3
• /
• pp.231-234
• /
• 2018

A schwannoma is a benign tumor that develops from Schwann cells. It is known to occur more frequently in women than men, and about one third of schwannoma cases occur in the head and neck area. It is also known to originate mainly in the auditory nerve. However, it is rarely associated with the trigeminal nerve, and especially, schwannomas related to the infraorbital nerve are very rare. we report a rare case of a schwannoma involving the infraorbital branch of the trigeminal nerve in a 45-year old male adult. The patient underwent physical examination and magnetic resonance imaging. The mass was approached through subciliary approach that is familiar to the plastic surgeon and completely resected. Histopathological findings showed pointed to a benign schwannoma. Infraorbital nerve schwannoma is difficult to distinguish from other diseases by means of clinical symptoms, physical findings, or imaging. In spite of its rarity, infraorbital nerve schwannoma may be considered a possible diagnosis in the case of mass on cheek. Assessment by computed tomography or magnetic resonance imaging is necessary for proper diagnosis. About the surgical approach, excision through the subciliary approach should be considered rather than the direct transfacial approach in view of stability, cosmetic effects, and familiarity.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.31 no.3
• /
• pp.239-247
• /
• 2005

This study demonstrated that xenogenic human marrow mesenchymal stem cells (hMSCs) could elicit the regeneration of the sensory nerve after axotomy in the adult rats infraorbital nerves without immunosuppression. For this, we evaluated the behavioral testing for functional recovery of the nerve and histological findings at weeks 3 and 5 compared to controls. Xenogenic hMSCs did not evoke any significant inflammatory or immunologic reaction after systemic and local administrations. HMSCs-treated rats exhibited significant improvement on sensory recovery tested with von Frey monofilaments. At 5 postoperative weeks, in the hMSCs treated nerve, expression of myelin basic protein (MBP), neurofilament (NF) at the site of axotomy was higher than control. And mRNA expression of neurotropin receptor Trk precursor (TrkPre), nerve growth factor receptor (NGFR) and neuropeptide (NPY) in trigeminal ganglion were also higher. The number of myelinated nerve at distal stump and cells in trigeminal ganglion were higher in hMSC treated rats. So it was supposed that transplanted MSCs contributed to reducing post-traumatic degeneration and production of neurotrophic factors. Immunofluorescence labeling showed small portion of hMSCs (<10%) expressed a phenotypic marker of Schwann cell (S-100). Xenogenic or allogenic mesenchymal stem cells might have immune privileged characteristics and useful tool for cell based nerve repair.