What's the difference between endoneurium and myelin?
Endoneurium
Definition:
(n.) The delicate bands of connective tissue among nerve fibers.
Example Sentences:
(1) 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.
(2) Whereas the tight junctions of endoneurial capillaries are known to prevent certain blood-borne substances from entering the endoneurium, it was not clear whether the permeability of the pulpal capillaries, which are distant from the nerve fibres, could affect the nerve fibre environment.
(3) However, the number of myelinated fibers measured per mm2 of endoneurium was reduced in both nerves 10 and 15 days after organophosphate administration, providing indirect evidence that fiber diameter is not critical in determining susceptibility to organophosphorus-induced delayed neuropathy (OPIDN).
(4) Transperineurial arterioles are defined as any arteriole that is confined to a perineurial cell compartment, which would include all arterioles within the perineurium proper or within perineurial sleeves in the epi- or endoneurium.
(5) The deposits were also located within the lumina of the vasa nervorum, some of which were undergoing disintegration and rupture with release of the proteinaceous material into the endoneurium.
(6) Electron microscopy showed the deposits to be composed of microtubular structures which were located diffusely throughout the endoneurium.
(7) Symptoms occur because adjacent nerve roots are impinged upon by the thin-walled, fluid-filled cysts, which are formed in a space between the endoneurium and the perineurium.
(8) There was marked collagen deposition in the endoneurium.
(9) In this study of biopsied human sural nerves, three-dimensional reconstruction of one micron sections and ultrastructural analysis of step serials, we find that TPA are confined in open-ended perineurial sleeves by which they pass from the epineurium through the perineurial sheath proper into the endoneurium.
(10) Peripheral nerves in this animal, as in vertebrates, are covered by endoneurium, perineurium, and epineurium.
(11) After an 8-wk period of vitamin E deprivation, forebrain, cerebellum, sciatic nerve endoneurium, liver, heart, muscle, testes and serum vitamin E concentrations were 51, 64, 65, 10, 20, 20, 40, and 19%, respectively, of initial values.
(12) The connective tissue space of this cell layer corresponds to the endoneurium, indicating that intermediate layer cells are comparable to endoneurial fibroblasts.
(13) The endoneurium consisted of collagen fibrils, and occasional fibroblasts and blood vessels.
(14) Streptozotocin (STZ)-induced diabetes in the rat causes a significant reduction in ouabain-sensitive Na,K-ATPase pumping activity measured by 86Rb+ influx, in sciatic endoneurium (by 54%) and dorsal root ganglia (by 22%).
(15) The study by the author and his co-workers of the innervation of the sheaths of extraorganic (spinal and cerebral) and intraorganic nerves has shown that their nervous apparatus is differentiated in accordance with differentiation of epi-, peri- and endoneurium.
(16) Many capillaries of the endoneurium, perineurium, and epineurium were affected in this way.
(17) At the onset of acute demyelination induced by tellurium (Te) poisoning, macrophages infiltrated the endoneurium and then began to express cytoplasmic immunoreactivity for apolipoprotein E (apo E).
(18) The localization of these macromolecules was investigated in basement membranes as well as in different areas of epi-, peri-, and endoneurium, by use of a pre-embedding immunoperoxidase method.
(19) Sural nerve specimens of 2 patients with an M protein reactive with chondroitin sulfate showed axonal degeneration and diffuse deposits of IgM in the endoneurium.
(20) The removal of products of degeneration, and in particular myelin debris, is accomplished by globule-laden cells which appear in the endoneurium during the first few days of repair.
Myelin
Definition:
(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.