Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Encephalomyelitis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

B cell-deficient mice have increased susceptibility to HSV-1 encephalomyelitis and mortality.

We studied the susceptibility of B cell-deficient mice to encephalomyelitis following intraperitoneal inoculation of HSV-1. B cell-deficient mice developed striking CNS signs including tail atony, clumsy gait and limb paralysis after HSV-1 infection. In addition, B cell-deficient mice had decreased survival (LD50 = 2.2 x 10(7) PFU) compared to control C57BL/6 mice (LD50 = 2.3 x 10(8) PFU). B cell-deficient mice had encephalomyelitis and detectable virus in the brain 7 days post-infection while C57BL/6 mice did not. Passive transfer of hyperimmune sera protected B cell-deficient mice from death, suggesting a role for antibody in susceptibility to HSV-1 encephalomyelitis.

Animals↗

The spectrum of postinfectious encephalomyelitis.

The medical records of 52 consecutive patients diagnosed with postinfectious encephalitis/encephalomyelitis during the period from 1980 to 1998, including 29 males and 23 females, were reviewed. These patients were divided into three groups according to their clinical and neurodiagnostic characteristics: (1) group I: postinfectious encephalitis, 38 patients; (2) group II: acute disseminated encephalomyelitis (ADEM), 13 patients; (3) group III: multiphasic disseminated encephalomyelitis (MDEM), one patient. Fever, headache/vomiting, seizure and disturbance of consciousness were common clinical features in all patients, while pictures of pyramidal, extrapyramidal, brainstem, and spinal cord lesions were more often found in the group II and group III patients than in the group I patients. Magnetic resonance imaging (MRI) revealed abnormal lesions in six (60%) of ten group I patients, but all group II (n=7) and group III (n=1) patients who received MRI study showed abnormal signals in various regions of the brain including the cerebral hemisphere, basal ganglia, brainstem and cerebellum. Patients with ADEM and MDEM had a longer clinical course and more neurological sequelae than group I patients. This study demonstrates the breadth of the clinical spectrum of postinfectious encephalomyelitis. Thorough clinical observations and appropriate neurodiagnostic studies such as MRI are crucial for the diagnosis.

Brain↗

Acquired aphasia in acute disseminated encephalomyelitis.

A 12-year-old boy developed a convulsion, hemiparesis, and acquired aphasia with paroxysmal electroencephalogram (EEG) abnormalities consisting of repetitive spikes and waves in the left centro-parietal region. T2-weighted magnetic resonance imaging disclosed high intensity lesions in the left pre-Sylvian and right frontal areas. He was diagnosed as having acute disseminated encephalomyelitis, and thus the oral administration of phenytoin and steroid pulse therapy were begun. With these treatments, his hemiparesis disappeared and the aphasia also improved gradually. Magnetic resonance imaging examination revealed the disappearance of the previously noted abnormalities, and the EEG abnormalities disappeared as well. This patient is a rare case of acute disseminated encephalomyelitis presenting an acquired aphasia. A focal lesion of acute disseminated encephalomyelitis may be responsible for the acquired aphasia. The distinction from Landau-Kleffner syndrome is also discussed.

Anti-Inflammatory Agents↗

Postnatal maternal deprivation aggravates experimental autoimmune encephalomyelitis in adult Lewis rats: reversal by chronic imipramine treatment.

Stressful experiences can modulate multiple sclerosis, but stress protection is currently not considered a treatment option. Here, we show that maternal deprivation, an adverse stress experience in infancy, increases emotionality in behavioral tests of adult female Lewis rats and concomitantly causes a more severe course of experimental autoimmune encephalomyelitis. Treatment of these effects in adulthood by chronic antidepressants (imipramine) reversed the behavioral symptoms and attenuated the course of the encephalomyelitis in deprived rats. Increased IL-4 plasma levels accompanied the protective-like effects of antidepressants. In contrast, attempts to prevent these effects in infancy by tactile stimulation aggravated the encephalomyelitis, possibly by decreasing corticosterone and increasing IFN-gamma levels during the disease. This indicates that antidepressants exert protective effects in an animal model of multiple sclerosis, and suggests that drugs modifying stress responsiveness may have a potential role as adjuvant treatment of the disease.

Animals↗

Genetics of susceptibility to chronic experimental encephalomyelitis and arthritis.

The recent developments in genetic techniques and the development of more appropriate animal models for rheumatoid arthritis and multiple sclerosis make it possible to use a new approach for understanding these complex diseases. Thus it is now meaningful to address the question of which genes are causing the diseases. Several new associations with loci outside the MHC region have now been identified in models for both rheumatoid arthritis and multiple sclerosis. Some of these are shared between diseases - for example loci on mouse chromosome 3 (experimental allergic encephalomyelitis, collagen-induced arthritis and Theiler's encephalomyelitis) and rat chromosome 4 (collagen-induced arthritis and the experimental allergic encephalomyelitis induced by myelin oligodendrocytic glycoprotein).

Animals↗

Specific binding of peroxidase-labeled myelin basic protein in allergic encephalomyelitis.

A conjugate of horseradish peroxidase and the encephalitogenic basic protein from myelin has been used to study the antigen reactivity of tissue in the autoimmune disease, experimental allergic encephalomyelitis. Control conjugates were also prepared of peroxidase and bovine serum albumin and of peroxidase and lysozyme, another basic protein. The basic protein from myelin conjugate was specifically bound by lymph node cells from rabbits immunized against the basic protein. Some of these cells appeared to be plasma cells. The conjugate was also specifically bound by occasional cells in the spinal-cord infiltrates of animals with early signs of allergic encephalomyelitis. These cells resembled large lymphocytes and plasma cells. There was no difference between the binding of basic protein of bovine and rabbit origin. The findings suggest the possibility that a local release of antibody within the target organ may play a role in the pathogenesis of allergic encephalomyelitis.

Animals↗

Antigen-specific therapy of experimental allergic encephalomyelitis by soluble class II major histocompatibility complex-peptide complexes.

Experimental allergic encephalomyelitis is a T-cell-mediated, major histocompatibility complex (MHC) class II gene-linked autoimmune demyelinating disease of the central nervous system. To develop therapies that will specifically inactivate only the autoantigen-reactive T cells, mice were treated with soluble MHC class II molecules that had been complexed with encephalitogenic peptides. Intravenous injections of 300 micrograms of complexes consisting of encephalitogenic peptide 91-103 of myelin basic protein plus I-As protein on day 0, 4, and 7 were effective in preventing experimental allergic encephalomyelitis. Similarly, administration of 45 micrograms of I-As protein complexed to peptide 139-151 from proteolipoprotein on day 1, 4, and 7 prevented mortality and significantly reduced paralysis induced by immunization with the encephalitogenic proteolipoprotein peptide. Histological examination of sections of animal brains revealed that treatment with I-As protein plus myelin basic protein 91-103 peptide prevents the development of inflammatory lesions characteristic of experimental allergic encephalomyelitis. Thus, treatment with MHC-self-peptide complexes could serve as a highly specific therapeutic modality in treating autoimmune disease when the putative autoantigen and the MHC restricting elements are known.

Animals↗

Staphylococcal enterotoxins can reactivate experimental allergic encephalomyelitis.

Staphylococcal enterotoxins (SEs) are one member of a unique group of molecules known as superantigens. They are potent T-cell activators and stimulate a large number of T cells bearing specific T-cell-receptor beta-chain variable regions. It has been proposed that superantigens may trigger autoimmune disorders by stimulation of autoreactive T cells with restricted beta-chain variable-chain usage. We investigated the effects of SEs B and A (SEB and SEA) on the reactivation of experimental allergic encephalomyelitis, an animal model for multiple sclerosis. We report that SEB can reinduce encephalitis multiple times in PL/J mice that had previously recovered from an acute episode. SEB was also able to induce encephalitis in mice previously immunized with myelin basic protein but did not show clinical signs of disease. In addition, it was observed that T cells from PL/J mice that had been previously activated by myelin basic protein in complete Freund's adjuvant or in complete Freund's adjuvant alone were resistant to the induction of anergy by SEB. To determine whether reactivation of experimental allergic encephalomyelitis was specific for SEB, another superantigen, SEA, was employed. It was found that SEA was also able to reinduce experimental allergic encephalomyelitis in mice previously recovered from an acute episode and those that had been previously immunized with myelin basic protein but did not show clinical signs of disease. These results indicate that SEs are capable of reactivating autoreactive T cells and inducing autoimmune disease.

Animals↗

Unimpaired autoreactive T-cell traffic within the central nervous system during tumor necrosis factor receptor-mediated inhibition of experimental autoimmune encephalomyelitis.

The critical role of tumor necrosis factor (TNF) as a mediator in autoimmune inflammatory processes is evident from in vivo studies with TNF-blocking agents. However, the mechanisms by which TNF, and possibly also its homologue lymphotoxin alpha, contributes to development of pathology in rheumatoid arthritis and Crohn disease and in animal models like experimental autoimmune encephalomyelitis is unclear. Possibilities include regulation of vascular adhesion molecules enabling leukocyte movement into tissues or direct cytokine-mediated effector functions such as mediation of tissue damage. Here we show that administration of a TNF receptor (55 kDa)-IgG fusion protein prevented clinical signs of actively induced experimental autoimmune encephalomyelitis. Significantly, the total number of CD4+ T lymphocytes isolated from the central nervous system of clinically healthy treated versus diseased control animals was comparable. By using a CD45 congenic model of passively transferred experimental autoimmune encephalomyelitis to enable tracking of myelin basic protein-specific effector T lymphocytes, prevention of clinical signs of disease was again demonstrated in treated animals but without quantitative or qualitative impediment to the movement of autoreactive T lymphocytes to and within the central nervous system. Thus, despite the uninterrupted movement of specific T lymphocytes into the target tissue, subsequent disease development was blocked. This provides compelling evidence for a direct effector role of TNF/lymphotoxin alpha in autoimmune tissue damage.

Animals↗

Mitochondrial protein nitration primes neurodegeneration in experimental autoimmune encephalomyelitis.

The mechanisms of axonal and neuronal degeneration causing visual and neurologic disability in multiple sclerosis are poorly understood. Here we explored the contribution of mitochondria to neurodegeneration in the experimental autoimmune encephalomyelitis animal model of multiple sclerosis. Oxidative injury to the murine mitochondrion preceded the infiltration of inflammatory cells, classically heralded as the mediators of demyelination and axonal injury by transection. Nitration of mitochondrial proteins affected key subunits of complexes I and IV of the respiratory chain and a chaperone critical to the stabilization and translocation of proteins into the organelle. Oxidative products were associated with loss of mitochondrial membrane potential and apoptotic cell death. Reductions in the rate of synthesis of adenosine triphosphate were severe and even greater than those associated with disorders caused by mutated mitochondrial DNA. Mitochondrial vacuolization, swelling, and dissolution of cristae occurred in axons as early as 3 days after sensitization for experimental autoimmune encephalomyelitis. Our findings implicate mitochondrial dysfunction induced by protein inactivation and mediated by oxidative stress initiates a cascade of molecular events leading to apoptosis and neurodegeneration in experimental autoimmune encephalomyelitis that is not mediated by inflammatory cells.

Amino Acid Sequence↗

Rehabilitation problems after acute disseminated encephalomyelitis: four cases.

The aim of this study is to describe rehabilitation problems in patients with acute disseminated encephalomyelitis. The study examines retrospective clinical data. Data are reported from 4 patients, who were consecutively admitted and examined with the Functional Independence Measure and magnetic resonance imaging. It was found that the lesions in the brains affected by acute disseminated encephalomyelitis are widespread, but become smaller with time. Motor symptoms dominate at first, but recovery is quite good. Social and cognitive functions are also affected, however, and require a much longer recovery time. These symptoms are, thus, the dominating problem in the rehabilitation ward. At clinical follow-up after 3 years the cognitive problems still influenced the lives of the patients. It is concluded that social and cognitive problems seem to be common in patients with acute disseminated encephalomyelitis. Recovery in these areas takes a long time and this is the main rehabilitation problem, since it affects the capability of the person to reintegrate into society.

Adult↗

Chronic experimental allergic encephalomyelitis induced in rabbits with bovine white matter proteolipid apoprotein.

A chronic, progressive form of experimental allergic encephalomyelitis was produced by immunization of rabbits with bovine brain white matter proteolipid apoprotein. Clinical signs appeared 4 to 13 months after sensitization, and were characterized by ataxia and limb paresis which progressed to flaccid paralysis and incontinence. Light and electron microscopic observations showed both acute and chronic nonsuppurative myelitis or encephalomyelitis accompanied by primary demyelination. Myelin damage was most evident in the spinal cord but was also present in the optic nerve and brain. The neuropathology was consistent with lesions of chronic experimental allergic encephalomyelitis produced by central nervous system tissue, and resembled lesions of multiple sclerosis as well. These observations suggest that protein may be involved in the pathophysiology of demyelinating diseases. A mechanism for the chronic course of the disease is discussed.

Animals↗

Eastern equine encephalomyelitis with hematuria and bladder dysfunction.

We have described a patient with eastern equine encephalomyelitis acquired in central Virginia, an area in which EEE is not ordinarily considered endemic. The unusual presenting features of our patient's encephalomyelitis were bladder dysfunction and hematuria as well as prominent mood and affect disturbances, which are usually seen in association with St. Louis encephalitis. The diagnosis of arboviral encephalomyelitis was considered because of the severe CNS manifestations and spinal cord involvement, and was facilitated by the detection of specific IgM antibodies in both the CSF and serum. A high index of suspicion is required to make the diagnosis of EEE, especially in nonendemic areas.

Adult↗

Coronavirus-induced encephalomyelitis: balance between protection and immune pathology depends on the immunization schedule with spike protein S.

The neurotropic mouse hepatitis virus MHV-JHM induces central nervous system (CNS) demyelination in Lewis rats that pathologically resembles CNS lesions in multiple sclerosis. The mechanisms of MHV-JHM-induced demyelination remain unclear and several studies have implicated the role of the immune response in this process. We have shown previously that protective immunity against MHV-JHM-induced encephalomyelitis was induced by immunization with a vaccinia virus (VV) recombinant expressing MHV-JHM S-protein (VV-S). Here, we present evidence that the time of MHV-JHM challenge after immunization with VV-S plays a critical role in protective immunity. The induction of virus-neutralizing S-protein-specific antibodies prior to the MHV-JHM challenge modulates the disease process and a subacute encephalomyelitis based on a persistent virus infection developed. Typical pathological alterations were lesions of inflammatory demyelination. In addition, the results indicate that after seroconversion, CD8+ T cells were no longer essential for virus elimination in contrast to their role in protection during acute encephalomyelitis.

Animals↗

Inhibition of experimental allergic encephalomyelitis in rats severely depleted of T cells.

Lewis rats depleted of thymus-derived cells (B rats) failed to develop either experimental allergic encephalomyelitis or antibody against myelin basic protein. Lewis B rats reconstituted with 690 x 10(6) thymocytes developed experimental allergic encephalomyelitis and levels of antibody against myelin basic protein comparable to those of controls. The Lewis B rat model should be useful in the analysis of the role of thymus-derived cell populations and antibody in the induction of experimental allergic encephalomyelitis.

Animals↗

The LPS receptor, CD14, in experimental autoimmune encephalomyelitis and multiple sclerosis.

Innate immune receptors are crucial for defense against microorganisms. Recently, a cross-talk between innate and adaptive immunity has been considered. Here, we provide first evidence for a role of the key innate immune receptor, LPS receptor (CD14) in pathophysiology of experimental autoimmune encephalomyelitis, the animal model of multiple sclerosis. Indicating a functional importance in vivo, we show that CD14 deficiency increased clinical symptoms in active experimental autoimmune encephalomyelitis. Consistent with these observations, CD14 deficient mice exhibited a markedly enhanced infiltration of monocytes and neutrophils in brain and spinal cord. Moreover, we observed an increased immunoreactivity of CD14 in biopsy and post mortem brain tissues of multiple sclerosis patients compared to age-matched controls. Thus, the key innate immune receptor, CD14, may be of pathophysiological relevance in experimental autoimmune encephalomyelitis and multiple sclerosis.

Animals↗

Accelerated response to reinoculation in experimental allergic encephalomyelitis: clinical study.

An attack of experimental allergic encephalomyelitis is generally thought to confer resistance to a second attack. Nevertheless, some authors have produced second attacks, sometimes with an anamnestic shortening of the incubation period. In addition, second attacks of experimental allergic encephalomyelitis with accelerated onsets following reinoculation were found in every experiment when histopathologic rather than clinical criteria were employed. In the present work, we found that clinical signs with accelerated onset were also found in each experiment provided that the first attack was produced with the aid of Freund's complete adjuvant and provided that the reinoculation stimulus was the highly potent combination of rat spinal cord and carbonyl iron. Whatever the potency of the reinoculation, and regardless of the occurrence of an accelerated onset, the eventual outcome was a decreased severity and mortality of the second attack of experimental allergic encephalomyelitis. The new data demonstrate that accelerated onset is not necessarily an indication of increased severity.

Adjuvants, Immunologic↗

Long-term inhibition of murine experimental autoimmune encephalomyelitis using CTLA-4-Fc supports a key role for CD28 costimulation.

T cell activation involves not only recognition of antigen presented by the MHC, but also nonspecific interactions termed "costimulation." The costimulatory molecules B7-1 and B7-2 are ligands on antigen-presenting cells for the CD28 and CTLA-4 receptors on T cells. Previously, a fusion protein consisting of human CTLA-4 linked to human Fc was shown to bind B7-1 and B7-2 with high avidity and to prevent specific T cell activation. Here we investigated the effects of a recombinant fusion protein consisting of the extracellular domain of human CTLA-4 bound to mouse IgG2a Fc (CTLA-4-Fc) upon experimental autoimmune encephalomyelitis, a T cell-mediated disease that serves as a model for multiple sclerosis. CTLA-4-Fc prevented experimental autoimmune encephalomyelitis in 26 of 28 CTLA-4-Fc-treated mice (median maximum score 0), whereas 28 of 30 mice treated with control mouse IgG2a developed disease (median maximum score 2.75). Less inflammation and virtually no demyelination or axonal loss occurred in CTLA-4-Fc-treated compared with control-treated mice. Activated splenocytes from CTLA-4-Fc-treated mice were able to transfer disease adoptively to naive recipients. These results indicate a key role for the B7/CD28 system in the development of actively induced murine experimental autoimmune encephalomyelitis, suggesting an area of investigation with therapeutic potential for multiple sclerosis.

Abatacept↗