No abstract available.
Humans* ; Myelin Basic Protein* ; Myelin Sheath* ; Myelin-Associated Glycoprotein* ; Oligodendroglia*

Studies in animals indicate that aconitine or aconite has toxic effects in the visual system of a rabbit model. Such a toxic effects causes myelo-optic neuropathy in the visually evoked cortical potential(VECP) and histopathologic studies. Whether the administration of intravenous high-dose of methyprednisolone(MP) in the myelo-optic neuropathy caused by aconitine(1.5ml/kg, equivalent to 0.7mg/kg of aconitine) is experimentally effective remains uncertain. The group treated with MP(daily 30mg/kg X 2 for 3 days followed by 15mg/kg for 3 days) in addition to aconite was compared with the aconite alone group and the normal control group. In the MP treated group, increased recovery of onset latency, peak latency, and amplitude in VECP in comparision with the aconite alone group was recorded at 2 weeks (p<0.05). The MP treated group in comparision with the normal control group showed a significant delay in onset latency at 1 month and 2 months(p<0.05). But, the amplitude in both the MP treated group and the aconite alone group increased at 2 months and did not show a significant difference in comparision with the normal group(p<0.05). In histopathologic study, pathologic findings of myelin sheath in the MP treated group were less severe than in the aconite alone group generally. The true benefit of high-dose MP was at least clear within 2 weeks. The authors conclude that treatment with intravenous high-dose MP immediate after aconite injection may have some beneficial effects in recovery of neurologic function although such a treatment do not have the definite recovery in aconite induced myelo-optic neuropathy.
Aconitine ; Aconitum* ; Animals ; Methylprednisolone* ; Myelin Sheath

Humans ; Myelin Sheath ; Astrocytes ; Phagocytosis ; Macrophages ; Ischemia

PURPOSE: To evaluate morphological differences in proprioceptors in extraocular muscles between congenital exotropia, acquired exotropia and congenital nystagmus. METHODS: Nine medial recti including the myotendinous junction were resected using medial rectus resection in three congenital and five acquired exotropia patients. Two medial recti and two lateral recti were resected using the modified Kestenbaum procedure in two congenital nystagmus patients. The muscle tissues were examined under a light microscope following examination with a transmission electron microscope. RESULTS: In the congenital exotropia group, the electron microscopic findings showed degenerative changes in proprioceptors, such as decreased microtubules, axonal shrinkage and decreased myelin thickness. In the acquired exotropia group, the neural structures in the myotendinous junction were well maintained. There were no neural structures in the myotendinous junction in the congenital nystagmus group. CONCLUSIONS: Depending on the type of strabismus, there may be morphological differences in proprioceptors of extraocular muscles.
Axons ; Exotropia* ; Humans ; Microtubules ; Muscles* ; Myelin Sheath ; Nystagmus, Congenital* ; Strabismus

PURPOSE: It has been known that there are several areas of T2 hyperintensities in normal white matter of brain, such as terminal zones of myelination, ependymitis granularis, ones of posterior internal capsule, and perivascular space. The aim of our study is to demonstrate another region of T2 hyperintensities in normal pediatric age group. MATERIALS AND METHODS: We have studied brain MR for 10 normal volunteers and 35 patients without having intracranial lesions in pediatric age group(3-19 years). RESULTS: In 5 among 45 cases, focal T2 hyperintensities were seen in the parietal periventricular white matter beneath the postcentral gyri. They were noted as poorly defined, 5--10mm sized areas of increased signal intensities on T2 weighted axial images. They were also characterized by bilateral, posteromedially oriented, short band-like or oval areas. Interestingly, they were directly continuous with the T2 hyperintensity of posterior internal capsule. In spite of the relatively high frequency in the pediatric population as in our study, this finding has not been reported in the asymptomatic adults. CONCLUSION: The results show that the bilateral anterior parietal hyperintense areas may be another terminal zones of delayed myelination affecting the parietopontine tract. They should be differentiated from pathologic T2 hyperintensities by their characteristic findings.
Adult ; Brain ; Healthy Volunteers ; Humans ; Internal Capsule ; Myelin Sheath ; Rabeprazole*

We report a case of an uncommon cutaneous neoplasm of nerve sheath myxoma in a 25-year-old woman who had a papule on the left cheek of her face. The histologic findings of the lesion showed that lobulated tumors were composed of spindle shaped and stellate tumor cells in an abundant matrix of mucosubstances. The electron microscopic findings showed numerous cytoplasmic myelin figures, and interdigitating long cytoplasmic processes. 5-100 protein was not discovered and alcian blue and PAS stain showed positive. After surgical excision of tumor, the patient did not have any evidence of disease for one year.
Adult ; Alcian Blue ; Cheek ; Cytoplasm ; Female ; Humans ; Myelin Sheath ; Neurothekeoma*

Palisaded encapsulated neuroma (PEN) is a distinctive benign cutaneous tumor that was first described by Reed et al. in 1972. We have recently experienced two cases of PEN. Clinically, these lesions were asymptomatic, flesh-colored or reddish brown papules or nodules. Light microscopy revealed several lobulated, partially encapsulated dermal tumors composed of interlacing Schwann cell fascicles. In some areas, palisading of nuclei was observed, but this was not characteristic. On Bodian staining, moderate to large numbers of tiny axons were observed. Electron microscopy demonstrated many myelinated axons incompletely invested by Schwan cell cytoplasm.
Axons ; Cytoplasm ; Microscopy ; Microscopy, Electron ; Myelin Sheath ; Neuroma*

Axons ; chemistry ; Myelin Sheath ; chemistry ; Staining and Labeling ; methods

Astrocytes (ASTs) and oligodendroglial lineage cells (OLGs) are major macroglial cells in the central nervous system. ASTs communicate with each other through connexin (Cx) and Cx-based network structures, both of which allow for quick transport of nutrients and signals. Moreover, ASTs interact with OLGs through connexin (Cx)-mediated networks to modulate various physiological processes in the brain. In this article, following a brief description of the infrastructural basis of the glial networks and exocrine factors by which ASTs and OLGs may crosstalk, we focus on recapitulating how the interactions between these two types of glial cells modulate myelination, and how the AST-OLG interactions are involved in protecting the integrity of the blood-brain barrier (BBB) and regulating synaptogenesis and neural activity. Recent studies further suggest that AST-OLG interactions are associated with myelin-related diseases, such as multiple sclerosis. A better understanding of the regulatory mechanisms underlying AST-OLG interactions may inspire the development of novel therapeutic strategies for related brain diseases.
Humans ; Myelin Sheath ; Astrocytes ; Oligodendroglia ; Brain ; Brain Diseases

Schwannomas are benign nerve sheath tumors composed of Schwann cells, which normally produce the insulating myelin sheath covering the peripheral nerves. Common locations include the head, neck, mediastinum, and retroperitoneum. These tumors are usually asymptomatic until they become large and compress the surrounding tissues. Most schwannomas occur during the third and fourth decades of life, with an equal gender distribution. We present the case of a schwannoma that originated in the scrotum.
Head ; Mediastinum ; Myelin Sheath ; Neck ; Nerve Sheath Neoplasms ; Neurilemmoma* ; Peripheral Nerves ; Schwann Cells ; Scrotum*