(n.) A soft white substance constituting the medullary sheats of nerve fibers, and composed mainly of cholesterin, lecithin, cerebrin, albumin, and some fat.
(n.) One of a group of phosphorized principles occurring in nerve tissue, both in the brain and nerve fibers.
Example Sentences:
(1) Histological studies of nerves 2 years following irradiation demonstrated loss of axons and myelin, with a corresponding increase in endoneurial, perineurial, and epineurial connective tissue.
(2) Cranial MRI revealed delayed myelination in the white matter but no brain malformation.
(3) We have examined the initial events in myelin synthesis, including the insertion and orientation of PLP in the plasma membrane, in rat oligodendrocytes which express PLP and the other myelin-specific proteins when cultured without neurons (Dubois-Dalcq, M., T. Behar, L. Hudson, and R. A. Lazzarini.
(4) Electron microscopic observations of the masseter nerve in the aged cats revealed a disruption of the myelin sheaths and a pronounced increase in collagen fibers in the endoneurium and perineurium.
(5) At 7 days axonal swellings were infrequently observed and the main structural feature was a reduction in myelin thickness in affected nerve fibers.
(6) We measured CSF immunoreactive myelin basic protein (MBP), a marker of acute myelin damage, and sIL-2R levels in the CSF from 11 patients with active relapsing remitting (RR) MS, five with stable RR MS, eight with chronic progressive (CP) MS, five with other neurologic diseases, and three normal controls.
(7) Of 533 myelinated sensory fibers, the size range was 2 micron.
(8) However, when beta-xyloside-treated cultures were supplied with exogenous basement membrane, Schwann cells produced numerous myelin segments.
(9) TCR beta chain gene expression of individual T cell clones that share the same MHC class II restriction and similar fine specificity for the encephalitogenic NH2 terminus of the autoantigen myelin basic protein (MBP) has been examined.
(11) This histochemical difference corresponded to more subtle differences in Nissl and myelin staining patterns, and suggests further structural subdivisions of potential functional significance.
(12) At S-L clefts, paranodal-nodal regions, and Schwann cell nuclei, the axonal areas were smaller and the NF densities were higher than at compact myelinated regions.
(13) We find that the labelled cell has a myelinated axon, but that the axon loses its myelin within 50 microns of the soma and has not yet been traced further.
(14) The apparent Km values for the myelin and the microsomal enzyme were 1.3 X 10(-4) M and 4.3 X 10(-4) M, respectively.
(15) The antigen (a protein doublet of Mr 75,000-80,000) is present in, but not restricted to, the myelin lamellae, since it is distributed along the whole myelinating Schwann cell membrane.
(16) It has been shown previously that oligodendrocytes, which synthesize and maintain myelin in the central nervous system (CNS), are susceptible to attack by homologous complement and that injury may be reversible when lysis is resisted by vesicular removal of membrane attack complexes.
(17) To test whether congenital nemaline myopathy (NM) might have a neurogenic basis, we evaluated the number and frequency distribution of L5 motoneuron cell bodies and their myelinated ventral root (VSR) axons in a typical case.
(18) Pre-treatment of human neutrophils with myelin basic protein selectively inhibits the formyl-peptide-induced chemotaxis, without affecting chemotaxis evoked by casein and activated serum.
(19) A rapid loss of nerve fibres apparently occurred early in the course of compression, since there was a marked decrease in the amount of nerve fibre swelling and Marchi stained degenerating myelin with increasing clinical duration.
(20) The results from gel filtration of glycopeptides indicate that there is a higher content of large molecular weight, sialic acid-rich oligosaccharide units in the glycoprotein of immature myelin.
Myelon
Definition:
(n.) The spinal cord. (Sometimes abbrev. to myel.)
Example Sentences:
(1) CT showed a compact bullet exactly intraspinal, with a syringiform cyst projecting into the myelon.
(2) In every case the fields are arranged in such a way that the myelon is not exposed to radiation.
(3) Myelogram, computer-assisted tomography and nuclear magnetic resonance tomography showed a large space-occupying mass from D8 to L1 epidural and dorsal of the myelon.
(4) The results explain the role the cerebellum plays in the modulation of the micturition reflex and confirm the importance of bilateral encephalic damage in causing vesico-sphincteral malfunctioning and the important role of the lateral myelon cords in transporting bladder proprioceptive sensitivity.
(5) The resulting immobilisation of myelon and nerve roots involves in the case of trauma a direct mechanical lesion and secondary vascular complications via Arteria vertebralis, spinalis anterior and radicularis, namely in patients with degenerative alterations of the cervical spine, these including a further narrowing behind the constitutional anomaly.
(6) Additional information is also obtained by means of GD-DTPA in extradural tumors: better delineation from the myelon, better possibilities to differentiate between meningiomas, neurinomas and scar and tumor.
(7) The axis lays within the myelon itself, and the central rays show an excentric deviation of 3 to 4 degrees.
(8) The advantages of the hyperfractionated radiation modality therefore are on one hand a higher regression-rate of subjective complaints, with equal good recovery of clinical and radiological findings and lack of side-effects especially those of the myelon, and on the other hand are resulting in a shortening of hospitalisation.
(9) One application of this radiation technique is the myelon-sparing treatment of the neck, another one the percutaneous completion of an intracavitary pre-radiation in the case of a gynecologic cancer.
(10) Clinical picture was characterized by a maculopathy, followed two years after by behavioural disturbances, psychomotor impairment, pyramidal signs and left-side myelonic jerks synchronously with the typical periodic R-complex in the EEG.
(11) In 7 cases with symptoms of severe compression of the myelon, decompressive laminectomy was performed, followed by radiotherapy.
(12) Compression of the myelon due to the applied bone wax was relieved directly after CT scan diagnosis.
(13) Myelography of high cervical region shows an enlarged epidural space and atrophy of the myelon.
(14) An abnormally cranial ending myelon surrounded by a widened spinal channel.
(15) Surgical treatment of vertebral tumors aims at eliminating the compression, thus relieving the myelon and the roots as well as the reestablishment of the supporting function of the involved segments.
(16) The excentric rotation technique presented guarantees that the exposition of the myelon doses not exceed 50% of the maximum dose.
(17) Especially MRI provides insights into the structure of the myelon; abnormal image signals may possibly correlate with cervical myelopathy based on disorders of microcirculation.
(18) 82 of these were located in the extradural compartment, 14 were found in the intradural-extramedullary space and 23 were situated inside the myelon.
(19) Cervical dislocations and instabilities are of special clinical relevance, jeopardizing the patient by a life threatening compression of the myelon in advanced cases.
(20) These results show the usefulness of transcranial magnetic brain stimulation as an additional noninvasive investigation for detecting compression of the cervical myelon.