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

In the present investigation evidence was obtained indicating that nasal instillations of suitable concentrations of sodium alum or tannic acid induce in Macacus rhesus monkeys resistance to the development of poliomyelitis when the virus is introduced by the nasal route. It was found that apparently different concentrations of these chemicals are required to exert this type of protective effect in different hosts or against different viruses, for while mice are readily protected against nasal infection with equine encephalomyelitis virus by 0.5 per cent solutions of tannic acid or alum (7), monkeys require at least 3 per cent solutions to become resistant against poliomyelitis. Experiments designed to elucidate the development of this refractory state in monkeys indicate that it is a result of the action of these chemicals not upon the virus but rather upon the tissues of the host (probably the olfactory mucosa); further evidence in favor of this hypothesis may be found in the observation that several days of treatment are required before resistance is induced. While one nasal instillation a day for 3 days proved effective when additional treatments were given on the days of virus administration, there was no protection against infection when the virus was given 48 and 96 hours after the last treatment. The resistance which was demonstrable when the virus was instilled intranasally on the 4th and 6th days after the beginning of treatment was also found to be present a week later when the treatments were given daily, indicating that the refractory state can be maintained in this manner. It was observed, however, that monkeys which were given nasal instillations of alum or tannic acid for 5 days or more may retain the resistance they acquired for 1 or 2 months without any additional treatment (Table V); thus, of 15 refractory monkeys retested after 1 month, 11 were still resistant; seven of 15 monkeys were refractory when retested after 2 months, while only one of 11 failed to develop poliomyelitis after an interval of 3 months. These last results suggest that to maintain such a refractory state over a period of months it may be necessary to employ daily instillations only for about a week, with subsequent repetitions at intervals of several days or a week. An experiment performed to determine the effect of beginning alum treatment soon after, rather than before, the virus is administered, indicated that there is no danger from a possible early or primary effect enhancing the invasiveness of the virus. One cannot state with any certainty, however, whether or not in some of the monkeys so treated the development of poliomyelitis is inhibited or prevented. Finally, it should be stressed that treatment with alum or tannic acid either completely prevented the disease in monkeys, or else was entirely without effect. It is therefore not surprising that no evidence was obtained of development of specific, active immunity in monkeys rendered refractory by chemical treatment. As far as could be ascertained, the nasal instillation of tannic acid or alum in man proved thoroughly innocuous beyond some local irritation for a short time. The desirability of testing this procedure as an aid in the prevention of poliomyelitis in man during the months of greatest incidence or during epidemics is quite apparent. In conclusion, there may be broader implications in this approach to the prevention of certain infectious diseases transmitted naturally or experimentally by way of the nose. It seems desirable to make studies with other viruses transmitted by the nasal route, including those of influenza and the common cold. The evidence obtained in the present study that the chemically induced refractory state may persist in a large number of monkeys for a month or two after treatment over a period of 5 days or more, suggests that studies on individuals who are subject to frequent attacks of common cold may perhaps be profitable.
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PMID:PROTECTIVE ACTION OF CERTAIN CHEMICALS AGAINST INFECTION OF MONKEYS WITH NASALLY INSTILLED POLIOMYELITIS VIRUS. 1987 May 11

Neuro-axonal degeneration occurs progressively from the onset of multiple sclerosis and is thought to be a significant cause of increasing clinical disability. Several histopathological studies of multiple sclerosis and experimental autoimmune encephalomyelitis have shown that the accumulation of sodium in axons can promote reverse action of the sodium/calcium exchanger that, in turn, leads to a lethal overload in intra-axonal calcium. We hypothesized that sodium magnetic resonance imaging would provide an indicator of cellular and metabolic integrity and ion homeostasis in patients with multiple sclerosis. Using a three-dimensional radial gradient-echo sequence with short echo time, we performed sodium magnetic resonance imaging at 3 T in 17 patients with relapsing-remitting multiple sclerosis and in 13 normal subjects. The absolute total tissue sodium concentration was measured in lesions and in several areas of normal-appearing white and grey matter in patients, and corresponding areas of white and grey matter in controls. A mixed model analysis of covariance was performed to compare regional tissue sodium concentration levels in patients and controls. Spearman correlations were used to determine the association of regional tissue sodium concentration levels in T(2)- and T(1)-weighted lesions with measures of normalized whole brain and grey and white matter volumes, and with expanded disability status scale scores. In patients, tissue sodium concentration levels were found to be elevated in acute and chronic lesions compared to areas of normal-appearing white matter (P < 0.0001). The tissue sodium concentration levels in areas of normal-appearing white matter were significantly higher than those in corresponding white matter regions in healthy controls (P < 0.0001). The tissue sodium concentration value averaged over lesions and over regions of normal-appearing white and grey matter was positively associated with T(2)-weighted (P < or = 0.001 for all) and T(1)-weighted (P < or = 0.006 for all) lesion volumes. In patients, only the tissue sodium concentration value averaged over regions of normal-appearing grey matter was negatively associated with the normalized grey matter volume (P = 0.0009). Finally, the expanded disability status scale score showed a mild, positive association with the mean tissue sodium concentration value in chronic lesions (P = 0.002), in regions of normal-appearing white matter (P = 0.004) and normal-appearing grey matter (P = 0.002). This study shows the feasibility of using in vivo sodium magnetic resonance imaging at 3 T in patients with multiple sclerosis. Our findings suggest that the abnormal values of the tissue sodium concentration in patients with relapsing-remitting multiple sclerosis might reflect changes in cellular composition of the lesions and/or changes in cellular and metabolic integrity. Sodium magnetic resonance imaging has the potential to provide insight into the pathophysiological mechanisms of tissue injury when correlation with histopathology becomes available.
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PMID:Brain tissue sodium concentration in multiple sclerosis: a sodium imaging study at 3 tesla. 2011 Feb 45

Therapy for central nervous system (CNS) diseases requires drugs that can cross the blood-brain barrier (BBB). BBB disruption has been reported in patients with multiple sclerosis (MS) and Alzheimer's disease (AD) and the related animal models as evidenced by increased infiltration of inflammatory cells or increased staining of Igs in the central nervous system. Although CNS penetration of therapeutic agents under pathological conditions has rarely been investigated, it is commonly assumed that BBB disruption may lead to enhanced CNS penetration and also provide a "window of opportunity" through which drugs that do not normally cross BBB are able to do so. In this article, we have compared brain penetration of eight small molecules in naive animals and experimental autoimmune encephalomyelitis (EAE) mice, streptozotocin-induced mice, and TASTPM transgenic mice. The tool compounds are lipophilic transcellular drugs [GlaxoSmithKline (GSK)-A, GSK-B, GSK-C, and naproxen], lipophilic P-glycoprotein (P-gp) substrates (amprenavir and loperamide), and hydrophilic paracellular compounds (sodium fluorescein and atenolol). Our data showed that rate and extent of CNS penetration for lipophilic transcellular drugs and P-gp substrates are similar in naive and all tested animal models. The brain penetration for paracellular drugs in EAE mice is transiently increased but similar to that in naive mice at steady state. Our data suggest that, despite reported BBB disruption, CNS penetration for small molecule therapeutic agents does not increase in MS- and AD-related animal models.
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PMID:Central nervous system penetration for small molecule therapeutic agents does not increase in multiple sclerosis- and Alzheimer's disease-related animal models despite reported blood-brain barrier disruption. 2042 91

Although there is growing evidence for a role of excess intracellular cations, particularly calcium ions, in neuronal and glial cell injury in multiple sclerosis, as well as in non-inflammatory neurological conditions, the molecular mechanisms involved are not fully determined. We previously showed that the acid-sensing ion channel 1 which, when activated under the acidotic tissue conditions found in inflammatory lesions opens to allow influx of sodium and calcium ions, contributes to axonal injury in experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis. However, the extent and cellular distribution of acid-sensing ion channel 1 expression in neurons and glia in inflammatory lesions is unknown and, crucially, acid-sensing ion channel 1 expression has not been determined in multiple sclerosis lesions. Here we studied acute and chronic experimental autoimmune encephalomyelitis and multiple sclerosis spinal cord and optic nerve tissues to describe in detail the distribution of acid-sensing ion channel 1 and its relationship with neuronal and glial damage. We also tested the effects of amiloride treatment on tissue damage in the mouse models. We found that acid-sensing ion channel 1 was upregulated in axons and oligodendrocytes within lesions from mice with acute experimental autoimmune encephalomyelitis and from patients with active multiple sclerosis. The expression of acid-sensing ion channel 1 was associated with axonal damage as indicated by co-localization with the axonal injury marker beta amyloid precursor protein. Moreover, blocking acid-sensing ion channel 1 with amiloride protected both myelin and neurons from damage in the acute model, and when given either at disease onset or, more clinically relevant, at first relapse, ameliorated disability in mice with chronic-relapsing experimental autoimmune encephalomyelitis. Together these findings suggest that blockade of acid-sensing ion channel 1 has the potential to provide both neuro- and myelo-protective benefits in multiple sclerosis.
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PMID:Acid-sensing ion channel 1 is involved in both axonal injury and demyelination in multiple sclerosis and its animal model. 2123 44

Stress granules (SG) are cytoplasmic aggregates of stalled translation preinitiation complexes that form in cells exposed to various environmental stresses. Here, we show that stress granules assemble in cells infected with Theiler's murine encephalomyelitis virus (TMEV) mutants carrying alterations in the leader (L) protein, but not in cells infected with wild-type TMEV. Stress granules also formed in STAT1-deficient cells, suggesting that SG formation was not a consequence of increased type I interferon (IFN) production when cells were infected with the mutant virus. Ectopic expression of the wild-type L protein was sufficient to inhibit stress granule formation induced by sodium arsenite or thapsigargin treatment. In conclusion, TMEV infection induces stress granule assembly, but this process is inhibited by the L protein. Unlike poliovirus-induced stress granules, TMEV-induced stress granules did not contain the nuclear protein Sam68 but contained polypyrimidine tract binding protein (PTB), an internal ribosome entry site (IRES)-interacting protein. Moreover, G3BP was not degraded and was found in SG after TMEV infection, suggesting that SG content could be virus specific. Despite the colocalization of PTB with SG and the known interaction of PTB with viral RNA, in situ hybridization and immunofluorescence assays failed to detect viral RNA trapped in infection-induced SG. Recombinant Theiler's viruses expressing the L protein of Saffold virus 2 (SAFV-2), a closely related human theilovirus, or the L protein of mengovirus, an encephalomyocarditis virus (EMCV) strain, also inhibited infection-induced stress granule assembly, suggesting that stress granule antagonism is a common feature of cardiovirus L proteins.
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PMID:The leader protein of cardioviruses inhibits stress granule assembly. 2175 8

We recently reported that a guanosine-rich 40-mer DNA aptamer (LJM-3064) mediates remyelination in the Theiler's murine encephalomyelitis virus mouse model of multiple sclerosis. Here, we characterize the G-quadruplex forms of this aptamer in vitro, and demonstrate using circular dichroism spectroscopy that LJM-3064 undergoes a monovalent ion-dependent conformational switch. In the presence of sodium ions and no potassium ions, LJM-3064 adopts an antiparallel-stranded G-quadruplex structure. When presented with low concentrations of potassium ions in a buffer that mimics the composition of interstitial fluid and blood plasma, LJM-3064 rapidly switches to a parallel-stranded G-quadruplex conformation, which is presumably the physiologically active folded form. We characterize these conformational states using dimethyl sulfate reactivity studies and Bal 31 nuclease probing. Our analysis indicates that only the 5'-terminal 26 nucleotides are involved in G-quadruplex formation. Thermodynamic characterization of LJM-3064 at physiologically relevant ion concentrations reveals the G-quadruplex to be metastable at human body temperature. These data provide important structural and thermodynamic insights that may be valuable in optimizing LJM-3064 as a therapeutic remyelinating agent.
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PMID:Ion-dependent conformational switching by a DNA aptamer that induces remyelination in a mouse model of multiple sclerosis. 2317 9

Axonal degeneration is a major cause of permanent disability in the inflammatory demyelinating disease multiple sclerosis, but no therapies are known to be effective in axonal protection. Sodium channel blocking agents can provide effective protection of axons in the white matter in experimental models of multiple sclerosis, but the mechanism of action (directly on axons or indirectly via immune modulation) remains uncertain. Here we have examined the efficacy of two sodium channel blocking agents to protect white matter axons in two forms of experimental autoimmune encephalomyelitis, a common model of multiple sclerosis. Safinamide is currently in phase III development for use in Parkinson's disease based on its inhibition of monoamine oxidase B, but the drug is also a potent state-dependent inhibitor of sodium channels. Safinamide provided significant protection against neurological deficit and axonal degeneration in experimental autoimmune encephalomyelitis, even when administration was delayed until after the onset of neurological deficit. Protection of axons was associated with a significant reduction in the activation of microglia/macrophages within the central nervous system. To clarify which property of safinamide was likely to be involved in the suppression of the innate immune cells, the action of safinamide on microglia/macrophages was compared with that of the classical sodium channel blocking agent, flecainide, which has no recognized monoamine oxidase B activity, and which has previously been shown to protect the white matter in experimental autoimmune encephalomyelitis. Flecainide was also potent in suppressing microglial activation in experimental autoimmune encephalomyelitis. To distinguish whether the suppression of microglia was an indirect consequence of the reduction in axonal damage, or possibly instrumental in the axonal protection, the action of safinamide was examined in separate experiments in vitro. In cultured primary rat microglial cells activated by lipopolysaccharide, safinamide potently suppressed microglial superoxide production and enhanced the production of the anti-oxidant glutathione. The findings show that safinamide is effective in protecting axons from degeneration in experimental autoimmune encephalomyelitis, and that this effect is likely to involve a direct effect on microglia that can result in a less activated phenotype. Together, this work highlights the potential of safinamide as an effective neuroprotective agent in multiple sclerosis, and implicates microglia in the protective mechanism.
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PMID:Safinamide and flecainide protect axons and reduce microglial activation in models of multiple sclerosis. 2358 55

Voltage-gated sodium channels (Navs) are involved in several aspects of the pathogenesis of multiple sclerosis (MS). Within acute MS plaques, they are expressed along demyelinated axons. Studies in experimental autoimmune encephalomyelitis (EAE) demonstrated a neuroprotective effect of non-specific Nav blockers. Further, block of specific Navs involved in MS is suggested to have an advantage over non-specific blockers. We investigated the effects of the synthetic Midi peptide in EAE, as it potently and specifically blocks Nav1.2, Nav1.4 and Nav1.6. Administration of this Midi peptide worsens the clinical disease pattern and Nav1.2 and Nav1.6 expression levels were elevated in brain but not in spinal cord of Midi-treated mice, implicating that Navs play a complex role in the pathogenesis of EAE.
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PMID:Block of a subset of sodium channels exacerbates experimental autoimmune encephalomyelitis. 2373 84

Progressive multiple sclerosis is associated with metabolic failure of the axon and excitotoxicity that leads to chronic neurodegeneration. Global sodium-channel blockade causes side effects that can limit its use for neuroprotection in multiple sclerosis. Through selective targeting of drugs to lesions we aimed to improve the potential therapeutic window for treatment. This was assessed in the relapsing-progressive experimental autoimmune encephalomyelitis ABH mouse model of multiple sclerosis using conventional sodium channel blockers and a novel central nervous system-excluded sodium channel blocker (CFM6104) that was synthesized with properties that selectively target the inflammatory penumbra in experimental autoimmune encephalomyelitis lesions. Carbamazepine and oxcarbazepine were not immunosuppressive in lymphocyte-driven autoimmunity, but slowed the accumulation of disability in experimental autoimmune encephalomyelitis when administered during periods of the inflammatory penumbra after active lesion formation, and was shown to limit the development of neurodegeneration during optic neuritis in myelin-specific T cell receptor transgenic mice. CFM6104 was shown to be a state-selective, sodium channel blocker and a fluorescent p-glycoprotein substrate that was traceable. This compound was >90% excluded from the central nervous system in normal mice, but entered the central nervous system during the inflammatory phase in experimental autoimmune encephalomyelitis mice. This occurs after the focal and selective downregulation of endothelial p-glycoprotein at the blood-brain barrier that occurs in both experimental autoimmune encephalomyelitis and multiple sclerosis lesions. CFM6104 significantly slowed down the accumulation of disability and nerve loss in experimental autoimmune encephalomyelitis. Therapeutic-targeting of drugs to lesions may reduce the potential side effect profile of neuroprotective agents that can influence neurotransmission. This class of agents inhibit microglial activity and neural sodium loading, which are both thought to contribute to progressive neurodegeneration in multiple sclerosis and possibly other neurodegenerative diseases.
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PMID:Lesional-targeting of neuroprotection to the inflammatory penumbra in experimental multiple sclerosis. 2428 15

Inflammatory monocyte-derived effector cells play an important role in the pathogenesis of numerous inflammatory diseases. However, no treatment option exists that is capable of modulating these cells specifically. We show that infused negatively charged, immune-modifying microparticles (IMPs), derived from polystyrene, microdiamonds, or biodegradable poly(lactic-co-glycolic) acid, were taken up by inflammatory monocytes, in an opsonin-independent fashion, via the macrophage receptor with collagenous structure (MARCO). Subsequently, these monocytes no longer trafficked to sites of inflammation; rather, IMP infusion caused their sequestration in the spleen through apoptotic cell clearance mechanisms and, ultimately, caspase-3-mediated apoptosis. Administration of IMPs in mouse models of myocardial infarction, experimental autoimmune encephalomyelitis, dextran sodium sulfate-induced colitis, thioglycollate-induced peritonitis, and lethal flavivirus encephalitis markedly reduced monocyte accumulation at inflammatory foci, reduced disease symptoms, and promoted tissue repair. Together, these data highlight the intricate interplay between scavenger receptors, the spleen, and inflammatory monocyte function and support the translation of IMPs for therapeutic use in diseases caused or potentiated by inflammatory monocytes.
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PMID:Therapeutic inflammatory monocyte modulation using immune-modifying microparticles. 2452 80


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