Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0014070 (encephalomyelitis)
 13,017 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biochemical and morphological studies of myelin subfractions were undertaken on Lewis rats during the early stage of the development of experimental allergic encephalomyelitis (EAE). Myelin subfractions, obtained by sucrose density gradient centrifugation at 10 days post-induction, were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and assayed for 2':3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) activity. Aliquots were processed for electron microscopic analysis. When comparing the myelin subfractions of EAE-affected animals with those of controls, differences were observed only in the light fractions, i.e., a decrease in the specific activity of CNPase and in the percentage of basic proteins relative to the total proteins of the fraction. This decrease was also evident in the basic protein/proteolipid protein ratio which is frequently used in the literature. In addition, electron microscopic observations demonstrated strong differences in the morphology of the same fraction. These findings suggest that the light fraction is the most sensitive in the early stages of the disease and must play a key role in demyelinating processes.
 ...
PMID:Biochemical changes in central nervous system membranes in experimental allergic encephalomyelitis. 301 92

An unresolved issue in the study of demyelinating disease is whether blood-brain barrier damage is dependent upon the migration of inflammatory cells into the central nervous system (CNS). In a study of experimental autoimmune encephalomyelitis (EAE) in rabbits, a freeze-dried, paraffin-embedded tissue technique was exploited to enable (1) the immobilization of intravenously injected sodium fluorescein tracer, as an index of vascular permeability; and (2) an effective labeling by monoclonal antibodies of both T-lymphocytes and mononuclear phagocytes in "unfixed" neural tissue. Using these newly combined methods, evidence was found that increased vascular permeability in the CNS during EAE occurs concomitantly with, and not prior to, infiltration by mononuclear phagocytes.
 ...
PMID:Simultaneous visualization of vascular permeability change and leukocyte egress in the central nervous system during autoimmune encephalomyelitis. 367 10

The 48-hour passive cutaneous anaphylaxis (PCA) and passive anaphylactic bronchoconstriction in rats induced by an IgE-like antibody against DNP-Ascaris were inhibited by intravenous treatment with traxanox sodium in a dose dependent manner. In both experiments, traxanox sodium was more potent than disodium cromoglycate (DSCG), especially as an inhibitor of bronchial anaphylaxis. In the PCA test of rats using a double sensitization technique according to the Orr's method, traxanox sodium was demonstrated not to inhibit antigen-antibody combination, but to inhibit the release of chemical mediators at a stage following antigen-antibody combination. Traxanox sodium inhibited the complement dependent immune hemolysis, but not the hypotonic hemolysis in vitro. However it failed to inhibit the Forssman anaphylaxis in the guinea pig in vivo. Traxanox sodium (50-250 mg/kg p.o.) showed an inhibitory effect on the direct passive Arthus reaction (DPAR) of the rats. Furthermore, it delayed the onset of the hyperacute form of experimental allergic encephalomyelitis (EAE) and reduced mortality in the rats. DSCG was less effective on DPAR and EAE. In conclusion, traxanox sodium is considered to have a wider spectrum of anti-allergic activity than DSCG since it has a suppressive effect not only on the type I allergic reaction, but also on the type III and IV allergic reactions.
 ...
PMID:[[Effect of traxanox sodium on type I-IV allergic reactions. Studies on anti-allergic agents VII]. 621 52

Theiler's murine encephalomyelitis viruses (TMEV) are separable into two groups based on their biological behavior: those highly virulent isolates which are unable to cause persistent infection and the less virulent isolates which regularly produce persistent central nervous system infection in mice. Two highly virulent and five less virulent TMEV were found to have the same buoyant density (1.34 g/ml) on isopycnic centrifugation and virion structure by electron microscopy. Negatively stained virus particles purified in Cs(2)SO(4) gradients appeared to have icosahedral symmetry and measured 28 nm in diameter. Mature virions were found to possess three major structural polypeptides, VP1, VP2 and VP3, in the range of 25,000 to 35,000 daltons, and a smaller fourth major polypeptide, VP4, of 6,000 daltons on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The precursor of VP2 and VP4, VP0, which is a minor polypeptide of mature picornavirus particles, was also identified. However, a slight but consistent difference in several of the capsid polypeptides between the highly virulent and less virulent TMEV was found. VP1 was slightly larger (34,000 versus 33,500 daltons) and VP2 was slightly smaller (31,000 versus 32,000 daltons) for the highly virulent strains compared to the same polypeptide species in the less virulent viruses. VP0 was also slightly smaller (35,500 versus 36,000 daltons) for the highly virulent isolates compared to their less virulent counterparts. Finally, trypsin which was used initially in our purification procedure resulted in preferential cleavage of a 2,000-molecular-weight fragment or fragments from VP1 of only the less virulent isolates.
 ...
PMID:Purification of Theiler's murine encephalomyelitis virus and analysis of the structural virion polypeptides: correlation of the polypeptide profile with virulence. 624 66

The WW strain of Theiler's murine encephalomyelitis virus (WW-TMEV) was purified from homogenates of acutely infected mouse brain. Infectious WW-TMEV was found to have an estimated sedimentation coefficient of 156 (s20,w) and a density of 1.35 g/cm3 in CsCl. Electron microscopy revealed a homogeneous population of 26-nm nonenveloped particles. Iodination of sodium dodecyl sulfate (SDS)-disrupted virions revealed four major capsid proteins with molecular weights of 58,000, 37,000, 34,000, and 27,000. A 6,000-dalton polypeptide was observed after long exposures of autoradiograms. The 37,000-, 24,000-, 27,000-, and 6,000-dalton polypeptides corresponded to picornaviral VP1, VP2, VP3, and VP4 capsid polypeptides, respectively. Comparison of autoradiograms of virions radiolabeled before and after SDS disruption indicated that the 58,000-dalton protein, VP2, and VP3 preferentially bound 125I under the labeling conditions used. Direct evidence was obtained that VP2 and VP3 were derived from the 58,000-dalton polypeptide by isolation of the 58,000-dalton polypeptide from polyacrylamide gels run under nonreducing conditions and subjecting it to reelectrophoresis under reducing conditions. The effect of trypsin on purified virions and their polypeptides was also investigated. Trypsin-sensitive sites were found in the 58,000-dalton protein, VP1, and VP2. Our results indicate that, in addition to the four typical picornaviral capsid polypeptides, there is a 58,000-dalton polypeptide present in WW-TMEV, which is sensitive to trypsin and can be reduced into two of the capsid proteins, VP2 and VP3.
 ...
PMID:Biochemistry of Theiler's murine encephalomyelitis virus isolated from acutely infected mouse brain: identification of a previously unreported polypeptide. 626 64

Pigeon herpes encephalomyelitis virus (PHEV) was stable at -70 C for at least 4 months. When stored at -20 C, the virus lost 80% of its infective titers in 4 months. When stored at -10 C, however, the titers decreased rapidly; no detectable virus remained within 12 weeks. PHEV was thermolabile: it was completely inactivated at 56 and 60 C for 10 and 2 min respectively. It was also killed by 1% cresol and 2% sodium hydroxide for two hr and 2% septol for 24 hr. Two-percent phenol or formaline for 2 hr, however, significantly decreased virus infective titers. Phenol-purified DNA extracted from PHEV showed an ultraviolet spectrum of typical nucleic acids that had ratios of absorbancies at 265 nm/280 nm between 2 and 2.3. The extracted viral DNA was infectious in chorioallantoic membrane and chick embryo fibroblast cell cultures, but it was not noninfectious when given to pigeons. DNA infectivity was destroyed by DNAse but not RNAse treatment. Extracted DNA was not neutralized by antiserum against the intact virus, and it lost its infectivity property when heated at 70 C for 10 min.
 ...
PMID:Viral encephalomyelitis of pigeons. VI. Some physico-chemical properties of the virus and extracted viral DNA. 626 86

When treated with formaldehyde, Tween 80, sodium oleate and Nonidet P-40, avian infectious bronchitis virus, porcine transmissible gastroenteritis virus, neonatal calf diarrhea coronavirus, porcine hemagglutinating encephalomyelitis virus as well as the human coronavirus show similar inner structures by negative staining. The first one is an inner membranous bag. This structure could be evaginated following treatments used and does not show the characteristic projections of coronaviruses. Subsequently, the inner fold could be separated from the outer membrane at the point of junction between these two membranes. Each virus does not react in the same way to the action of the different products. The transmissible gastroenteritis virus appears more sensitive to treatments than other viruses. On the other hand, the hemagglutinating encephalomyelitis virus is the most resistant. The variable sensitivities of these viruses are not related to the type of host-cells. Also, a second internal structure, which is more dense than the viral particle, encircles partially the aperture of the internal tongue-shaped structure and seems to emerge from the viral particle through the aperture of the inner bag.
 ...
PMID:Inner structures of some coronaviruses. 626 23

Growth and neurovirulence of a number of neurotropic viruses show pronounced differences after passage in cell culture compared with continued in vivo passage in the central nervous system. The DA strain of Theiler's murine encephalomyelitis virus provides a model for studying these issues since DA virus grown in mouse brain produces acute neuronal disease in weanling mice, but tissue culture-passed DA virus does not. In addition, DA virus grown in mouse brain has a greater 50% mouse lethal dose/50% tissue culture infective dose ratio than tissue culture-passed DA virus. Comparison of these viruses required the analysis of virus purified directly from infected mouse brain, without tissue culture passage. Capsid proteins from DA virus grown in mouse brain were resolved on sodium dodecyl sulfate-polyacrylamide gels and shown to have the same profile as tissue culture-passed DA virus. Viral RNAs were the same size, with no evidence of defective interfering particle production. Two-dimensional gels of in vitro-labeled RNase T1-digested RNA showed that virus variants were more apparent during acute in vivo passage. These genomic differences may be critical in determining the biological behavior of the virus.
 ...
PMID:Biochemical analysis of DA strain of Theiler's murine encephalomyelitis virus obtained directly from acutely infected mouse brain. 632 29

Spinal cord sections from Lewis rats with acute experimental allergic encephalomyelitis (EAE) showed greatly increased staining of astrocytes when stained immunocytochemically for glial fibrillary acidic protein (GFAP). Fibrous processes in white matter were heavily stained early in the course of the disease when paralysis was first evident (10-12 days after injection of guinea pig spinal cord myelin), then protoplasmic astrocytes were stained in the gray matter and became more heavily stained at 20 days post-injection. The stained astrocytes were evenly distributed throughout the tissue, and did not correspond to the sites of the lesions. Spinal cord slices of control and EAE rats were incubated with [3H]amino acids, then cytoskeletal proteins were prepared in an enriched fraction, separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the protein bands counted for radioactivity. In the EAE rat all cytoskeletal proteins, including the neurofilaments, vimentin, microtubules, GFAP and actin, showed increased uptake of radioactive amino acids. Immunoprecipitation of GFAP with specific antiserum showed increased radioactivity in the complex beginning at day 10 when cellular infiltration was beginning in the EAE animals. As the disease became acute, the radioactivity in the immunoprecipitated GFAP increased, in some cases to very high levels, then by day 18 when recovery was underway, the radioactivity had fallen to normal levels. Possible agents causing metabolic activation of protein synthesis in EAE animals include stimulating substances elaborated by infiltrating lymphoid cells, and the generalized edema accompanying the demyelinative condition. The activation of GFAP protein staining and metabolism in EAE might serve as a model for the activated growth of astrocyte processes which cause the severe gliosis seen in multiple sclerosis.
 ...
PMID:Immunocytochemical staining for glial fibrillary acidic protein and the metabolism of cytoskeletal proteins in experimental allergic encephalomyelitis. 634 9

The question of what happens to cholesterol in the adult central nervous system during its slow turnover has been addressed using rats with brain and spinal cord labeled with [4-14C]cholesterol upon intracerebral injection of labeled cholesterol into rats at 10-12 days of age. At six months after injection, 14C was found only in the brain and spinal cord and was slowly released via the rat's urine. When labeled rats were given demyelinating agents (triethyl tin chloride, hexachlorophene, sodium cyanide) and when experimental allergic encephalomyelitis was induced, a measurable increase in urinary 14C label above control levels was found. It was concluded that there is a direct relationship between the experimental demyelination induced and the increased release of cholesterol metabolites into urine. The study suggests that a clinical method could be developed to determine the rate of central nervous system demyelination by measuring the amount of urinary cholesterol metabolites.
 ...
PMID:Central nervous system demyelinating diseases and increased release of cholesterol into the urinary system of rats. 781 95


<< Previous 1 2 3 4 5 6 7 8 9 Next >>