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Query: UMLS:C0027121 (myositis)
 4,538 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This review emphasizes new advances in seeking the pathogenic mechanisms of sporadic inclusion-body myositis and hereditary inclusion-body myopathy syndromes. Clinical and pathologic similarities and differences between sporadic and hereditary forms are described. Hypotheses are presented regarding the possible causes and consequences of abnormally accumulated intramyofiber beta-amyloid precursor protein (beta APP) (including beta-amyloid protein and C- and N-terminal epitopes), hyperphosphorylated tau, alpha 1-antichymotrypsin, apolipoprotein E, prion protein, ubiquitin, nicotinic acetylcholine receptor and its 43-kD associated protein, fibroblast growth factor, and transforming growth factor-beta. Also increased are beta APP mRNA and prion protein mRNA. Striking similarities between the pathology of muscle specimens from sporadic inclusion-body myositis and samples from the brains of patients with Alzheimer's disease in regard to Congo red positivity and accumulations of several proteins are discussed. Because most of the proteins that pathologically accumulate throughout the abnormal muscle fibers also accumulate focally at normal human neuromuscular junctions, the possible "junctionalization" of nonjunctional nuclei as a pathogenic mechanism in the muscle fiber is discussed.
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PMID:New advances in the understanding of sporadic inclusion-body myositis and hereditary inclusion-body myopathies. 857 68

Sporadic inclusion body myositis and the hereditary inclusion body myopathies are severe, progressive muscle diseases, characterized pathologically by vacuolated muscle fibers containing paired helical filaments. We immunostained muscle biopsy specimens from sporadic inclusion body myositis, hereditary inclusion body myopathy, disease control, and normal patients with several antibodies against apolipoprotein E (ApoE). Approximately 80 to 90% of the vacuolated muscle fibers of sporadic inclusion body myositis contained well-defined, strongly immunoreactive ApoE inclusions. In hereditary inclusion body myopathy, only rare vacuolated fibers had immunoreactive inclusions, whereas most had diffuse cytoplasmic ApoE immunoreactivity. Ultrastructurally, ApoE immunoreactivity in sporadic myositis was localized mainly to the paired helical filaments. By contrast, in the hereditary form, ApoE immunoreactivity occurred on material in close proximity to the paired helical filaments, but never was on the paired helical filaments. In both muscle diseases, ApoE was also on the 6- to 10-nm filaments and amorphous material. In the sporadic form, ApoE-immunoreactive deposits colocalized with Congo red-positive deposits; however, in muscle fibers from patients with hereditary disease there was no congophilia. ApoE messenger RNA was not detectable in muscle fibers from patients with hereditary or sporadic disease but was expressed abundantly in muscle macrophages. In all control and inclusion body myositis or myopathy biopsy specimens, ApoE immunoreactivity was strong at the postsynaptic domain of neuromuscular junctions; nonjunctional regions of normal fibers were negative for ApoE. ApoE immunoreactivity occurred diffusely in regenerating muscle fibers, a subset of which had detectable ApoE messenger RNA.
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PMID:Apolipoprotein E and apolipoprotein E messenger RNA in muscle of inclusion body myositis and myopathies. 900 91

Sporadic inclusion-body myositis (s-IBM) is the most common progressive muscle disease of older persons. The muscle biopsy demonstrates mononuclear cell inflammation and vacuolated muscle fibers containing paired helical filaments and 6- to 10-nm fibrils, both resembling those of Alzheimer disease brain and Congo red positivity. The term hereditary inclusion-body myopathies (h-IBMs) designates autosomal-recessive or autosomal-dominant disorders with muscle biopsies cytopathologically similar to s-IBM but without inflammation. Vacuolated muscle fibers of both s-IBM and the h-IBMs contain accumulations of several "Alzheimer-characteristic proteins" including beta-amyloid protein and beta-amyloid precursor protein, and their paired helical filaments are composed of phosphorylated tau. We used six well characterized antibodies against several residues of presenilin 1 (PS1) to immunostain muscle biopsies of 12 patients with s-IBM, 5 patients with autosomal-recessive inclusion-body myopathy, and 16 normal and disease controls. Seventy to eighty percent of the vacuolated muscle fibers of both s-IBM and autosomal-recessive inclusion-body myopathy had inclusions that were strongly PS1-immunoreactive, which by immunoelectron microscopy localized mainly to paired helical filaments and 6- to 10-nm filaments. None of the control biopsies had PS1-positive inclusions characteristic of the s- and h-IBM abnormal muscle fibers. Mutations of the newly discovered PS1 gene are responsible for early-onset familial Alzheimer disease (AD), and PS1 is abnormally accumulated in sporadic and familial AD brain. Our study provides the first demonstration of PS1 abnormality in non-neural tissue and in diseases other than AD and suggests that the cytopathogenesis in AD brain and IBM muscle may share similarities.
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PMID:Light and electron microscopic immunolocalization of presenilin 1 in abnormal muscle fibers of patients with sporadic inclusion-body myositis and autosomal-recessive inclusion-body myopathy. 954 49

A 47-year-old man presented with complaints of progressive diplopia in downgaze and a painful firm mass on the left medial superior canthus. On examination, there was marked hyperemia of the superior bulbar conjunctiva of the left eye. Systemic examination revealed erythematous papules on his trunk and pulmonary infiltrates. CT of the orbits revealed a fusiform enlargement of the left superior oblique muscle and diffuse infiltration of the left temporal region. Biopsy of the left superior oblique muscle and temporal muscle disclosed Congo red deposits that show apple-green birefringence under polarized light. A comprehensive systemic investigation failed to show any disease that could explain the amyloid deposits. The patient was then diagnosed as having primary systemic amyloidosis. We think that this case highlights the necessity of a biopsy in any atypical extraocular muscle enlargement before a diagnosis of myositis.
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PMID:Superior oblique muscle amyloidosis mimicking myositis. 1820 59

A 48-years old man was diagnosed an IgD-k multiple myeloma (MM) at age 38 years for which he successfully underwent chemotherapy and bone marrow transplant. He then developed a graft-versus-host disease (GVHD) whose manifestations included, three years later, a polymyositis, diagnosed at muscle biopsy and successfully treated with steroids. Few months after polymyositis remission, myeloma relapsed and the patient was treated with thalidomide for six years with good remission. Soon after thalidomide suspension, MM relapsed again and the patient came to our observation for a new onset of neuromuscular symptoms. He underwent both muscle and peripheral nerve biopsy to discriminate between myositis (paraproteinemia versus GVHD), amyloidosis, and thalidomide toxicity. The first muscle biopsy showed an inflammatory pattern with necrotic fibres, macrophagical invasion (CD68 positive), rare interstitial cellular infiltrates (CD8 positive and CD4 negative), widespread anti-HLA positivity and negative antiMAC. The second muscle biopsy showed the same inflammatory pattern plus an involvement of blood vessels. Direct immunofluorescence for IgD showed diffuse positivity along the sarcolemmal in both muscle biopsies. Sural nerve biopsy demonstrated both demyelinating and axonal aspects with no inflammatory infiltrates, but positivity for HLA and MAC. Congo Red was negative in both skeletal muscle and peripheral nerve.
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PMID:IgD Multiple Myeloma Paraproteinemia as a Cause of Myositis. 2118 28

Between April 2013 and April 2015, seven flocks belonging to three different major commercial egg producers inCalifornia experienced a mild increase in mortality 2 to 3 wk after administration of Salmonella Enteritidis bacterins. Strains of chickens involved were H&N (flock A1, A2, B2, C1, C2, and C3) and Lohmann white (flock B1). Vaccination was administered individually through injection either in the breast muscles or subcutis in the legs between 11 and 18 wk of age in all flocks. Clinical signs ranged from inapparent to lameness, reluctance to walk, greenish diarrhea, and retching-like symptoms. The mortality ranged from 0.16% to 1.38% per week, with the highest peaks occurring usually 2 to 3 wk postvaccination, and then declined rapidly. Postmortem examinations revealed enlarged livers with disseminated hemorrhages and pale foci of necrosis. Also, severe extensive hemorrhages in the intestine, heart, and proventriculus were observed in a few birds. Various degrees of productive, exudative giant cell granulomatous myositis were observed invading deeply the muscles and subcutis at the site of vaccination. The myositis was always associated with optically empty vacuoles positive for neutral lipids by Oil Red O stain. Droplets of Oil Red O material were also noticed in the affected livers and intestines. Congo red stain highlighted the presence of amyloid in moderate to severe amounts in the breast muscles and moderate amounts in livers, spleens, and intestines. Salmonella antigens were detected in the injection sites and livers by immunohistochemical staining. No viruses or toxic substances were recovered from the liver, spleen, intestine, and pectoral muscles, and the few bacteria isolated were interpreted as secondary postmortem invaders. In addition, livers and bile tested for hepatitis E virus were negative by reverse-transcriptase polymerase chain reaction.
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PMID:Characterization of Seven Outbreaks of Hemorrhagic Hepatopathy Syndrome in Commercial Pullets Following the Administration of a Salmonella Enteritidis Bacterin in California. 2695 41