Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011633 (dermatomyositis)
 4,181 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pathological diagnosis of dermatomyositis (DM), polymyositis (PM), and inclusion body myositis (IBM) should be possible in almost all cases when an appropriately involved muscle is biopsied. DM shows characteristic patterns of muscle fiber damage and capillary damage. Lymphocytes and macrophages are seen in PM and IBM partially invading non-necrotic fibers. IBM is also characterized by rimmed vacuoles with membranous whorls, characteristic masses of filaments in cytoplasm and sometimes in nuclei, and grouped atrophic fibers. Muscle fiber damage in PM is more variable. Inflammatory myopathy can be associated with HTLV-1 and HIV infection. In the latter a strong resemblance to PM is reported. Separate, still less well characterized forms of inflammatory myopathy occur in young children.
 ...
PMID:The pathological diagnosis of specific inflammatory myopathies. 134 42

The inflammatory myopathies encompass a group of heterogenous muscle diseases which have in common an acquired myopathy with histological signs of endomysial inflammation. We present evidence based on recently emerged clinical, histologic, immunopathologic, demographic and therapeutic observations that these myopathies comprise three major and distinct groups: polymyositis (PM), dermatomyositis (DM), and inclusion-body myositis (IBM). Immune-mediated mechanisms characteristic for each group appear to play a primary role in the pathogenesis of these diseases. In DM there is an intramuscular microangiopathy mediated by the C5b-9 membranolytic attack complex, leading sequentially to loss of capillaries, muscle ischemia, muscle fiber necrosis and perifascicular atrophy. In contrast, in PM and IBM the muscle fiber injury is initiated by sensitized CD8+ cytotoxic T cells that recognize MHC-I restricted muscle antigens, leading to phagocytosis and fiber necrosis. Among the viruses implicated in the cause of inflammatory myopathies, only the retroviruses, HIV, HTLV-1 and simian retroviruses, have been convincingly associated with PM. Retroviruses, therefore, appear to be the leading group of viruses capable of triggering these diseases. The treatment of inflammatory myopathies has been largely empirical. A detailed therapeutic plan based on our experience with a large number of patients is presented. Patients with bona fide PM or DM respond to steroids to some degree and for some period of time. In contrast, patients with IBM do not respond to any therapy and the disease should be suspected when a patient with presumed PM has failed treatment. Methotrexate and cyclophosphamide are disappointing. Cyclosporine and Azathioprine are commonly used but they are of uncertain benefit. Plasmapheresis is ineffective. High-dose intravenous immunoglobulin is a promising new therapeutic modality.
 ...
PMID:Clinical, immunopathologic, and therapeutic considerations of inflammatory myopathies. 142 35

The present study attempts to investigate the pathological basis of the two clinically different forms of idiopathic inflammatory myopathy (IIM) namely, polymyositis (PM) and dermatomyositis (DM). Clinicopathological analysis of 73 cases showed that muscle fibre necrosis and regeneration were more frequent in PM than in DM, the latter being significantly so (P < 0.05). On the other hand, vasculitis was more associated with DM while perifascicular atrophy of the muscle fibres was confined to it. Vasculitis was present in eight cases. Its incidence in patients with myositis with systemic connective tissue disease (4/9) was significantly more than in other PM and DM patients (P < 0.01). An equally significant higher frequency of perimysial inflammatory infiltrate was also seen in the former as compared to the latter. Interestingly, idiopathic DM affected men as often as women and juvenile IIM affected boys more frequently than girls. A female predilection was noted in the remaining groups of IIM. These observations indicate that there may be some basic immunopathogenetic differences between polymyositis and dermatomyositis as well as between idiopathic PM/DM and that associated with systemic connective tissue diseases. Though the number of patients studied is small, the absence of female predilection in idiopathic DM and juvenile IIM may be peculiar to the IIM in the tropics.
 ...
PMID:Idiopathic inflammatory myopathy: clinicopathological observations in the Indian population. 145 90

During the course of a systematic study of T cell lines derived from muscle of patients with various inflammatory myopathies, we identified a new form of polymyositis that is mediated by gamma-delta T cells. In the affected patient's muscle CD3+CD4-CD8- gamma-delta T cells surrounded and invaded nonnecrotic muscle fibers in the same way as CD3+CD8+ alpha-beta T cells surround and invade nonnecrotic muscle fibers in inclusion body myositis and other forms of polymyositis. Gamma-delta T cells were extremely rare or absent in muscles and muscle-derived T cell lines in other patients with polymyositis, inclusion-body myositis, dermatomyositis or granulomatous myopathy. This new form of polymyositis has provided us with a unique opportunity to study cytotoxic gamma-delta T cells and their muscle-fiber targets in situ. All muscle fibers expressed HLA-class I antigen and the 65-kD heat-shock protein. The autoaggressive behavior of the gamma-delta T cells is consistent with the hypothesis that in some inflammatory myopathies autoinvasive T cells recognize muscle fiber associated antigen(s). Further studies are needed to define the type of gamma-delta T cell receptor used and the antigen(s) recognized by gamma-delta T cells in this rare type of autoimmune muscle disease.
 ...
PMID:The role of gamma-delta T lymphocytes in inflammatory muscle disease. 153 37

I studied vimentin and desmin immunoreactivities in the skeletal muscle of 30 human fetuses and children ranging from 8 weeks' gestation to 2 years of age, and in 45 infants and children and five adults with developmental neuromuscular diseases. Acridine orange-RNA fluorescence also identified regenerating myofibers in Duchenne muscular dystrophy and dermatomyositis for comparison with congenital myopathies. Vimentin and desmin are both strongly expressed in fetal myotubes and their immunohistochemical demonstration persists until 36 weeks' gestation. These cytoskeletal proteins are uniformly expressed in myofibers of neonates with X-linked recessive myotubular myopathy. Desmin but not vimentin is diffusely increased in infantile cases of myotonic dystrophy, in some cases of congenital muscle fiber-type disproportion, and in cerebrohepatorenal disease. In nemaline rod myopathy, desmin is focally increased in perinuclear zones and in regions of aggregated rods. The small myofibers in infantile spinal muscular atrophy show increased vimentin and desmin in the subsarcolemmal region. The demonstration of these intermediate filament proteins provides markers to enhance diagnostic precision in the interpretation of the infant muscle biopsy. Furthermore, persistently high fetal concentrations of vimentin/desmin may play a role in the pathogenesis of some developmental myopathies.
 ...
PMID:Vimentin and desmin in maturing skeletal muscle and developmental myopathies. 164 Nov 60

Inclusion body myositis (IBM) represents a serious debilitating disease of muscle without identifiable cause or treatment. Muscle biopsy specimens have characteristic rimmed vacuoles, varying degrees of inflammation, and, most importantly, cytoplasmic and intranuclear filamentous inclusions of unknown composition. Fresh-frozen sections of muscle biopsy specimens from 24 IBM cases were stained with Congo red dye (pH, 10.5 to 11.0). Control biopsy specimens included polymyositis, dermatomyositis, hereditary vacuolar myopathies of unknown cause, acid maltase deficiency, distal myopathy, oculopharyngeal dystrophy, and chloroquine myopathy. Sections were also immunostained with antibody to transthyretin, human P component, and immunoglobulin light chains. In the vacuolated fibers in IBM, amyloidogenic green-birefringent deposits were seen. Some deposits were delicate and wispy appearing, and others were plaque-like. The size of deposits varied, measuring 1 x 2 to 8 microns, and rarely up to 20 microns in length. The number of amyloid-positive fibers correlated with the number of vacuolated fibers. Similar deposits were seen in one case of distal myopathy and one hereditary vacuolar myopathy. Other control cases were negative for amyloid deposits. Antibody staining for known amyloidogenic proteins was negative. This study demonstrates that the filaments in IBM share properties with amyloid proteins. The location implies that this amyloid material is formed intracellularly, rather than having a systemic derivation. The association of amyloid deposits with autophagic vacuoles in IBM raises the likely possibility that the filaments represent a modification of a normal protein within an acidic degradative vacuolar compartment. An alternative possibility, considering the shared properties of IBM filaments and prions (which include size and amyloidogenic properties), is that IBM represents a human prion disease.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Amyloid filaments in inclusion body myositis. Novel findings provide insight into nature of filaments. 166 77

Polymyositis and dermatomyositis are inflammatory myopathies characterized by proximal muscle weakness and myopathic electromyographic and histological findings. While the causes of myositis are not known, the close association of these disorders with a spectrum of autoantibodies suggests an etiologic and/or pathogenetic role for autoimmune processes. Of particular interest in this regard are antibodies directed against histidyl as well as other tRNA synthetases which are almost uniquely associated with myositis and may define a distinct subset of patients. Recently we isolated the histidyl tRNA synthetase gene which encodes the autoantigen representing the most frequent target of the myositis autoimmune response. The isolation and expression of this gene has allowed us to investigate both the autoreactive epitopes on histidyl-tRNA synthetase and the extent to which these correlate with functional epitopes on the molecule. As described here, the results of these studies as well as other recent data pertaining to the immunopathogenesis of myositis, provide a framework for delineating the mechanisms which render synthetases and other translation-related proteins autoantigenic in myositis, and allow one to examine the significance of such autoimmune responses in the etiology and pathogenesis of inflammatory myopathy.
 ...
PMID:Anti-Jo-1 autoantibodies and the immunopathogenesis of autoimmune myositis. 172 33

A series of 31 patients suffering idiopathic inflammatory myopathy (IIM); we describe the extramuscular manifestations, specially pulmonary, the association to neoplasia, the histopathological characteristics, and their response to treatment. Fourty three percent of IIM patients presented a pulmonary involvement, 9% presented an associated neoplasia. The histopathological study allowed us to clearly differentiate dermatomyositis and polymyositis within IIM. 65% of patients initially responded to glucocorticoids and the most usefull therapeutic alternatives were azatioprine and cyclosporin-A.
 ...
PMID:[Idiopathic inflammatory myopathy. Analysis of 31 patients]. 176 9

Animal models have proven very useful in furthering insight into a number of muscle diseases. Studies of ethanol-fed rats are being used to understand the pathogenetic mechanisms underlying acute and chronic myopathy induced by ethanol. Several animal species, including mice, dogs, and cats, develop X-linked muscular dystrophies, which have genetic defects identical to those of Duchenne muscular dystrophy. As in the human disease, these animals lack dystrophin. They are being used to investigate the mechanisms by which lack of dystrophin results in weakness and to examine myoblast transfer as a treatment modality. A model of eosinophilia-myalgia syndrome has recently been induced in Lewis rats by the feeding of L-tryptophan samples that were implicated in the clinical syndrome in humans, making possible studies of the pathogenesis of this interesting new entity. A dermatomyositis-like syndrome occurs spontaneously in dogs, and polymyositis-like illnesses can be induced in mice by immunization with muscle or following infection with selected viruses, especially enteroviruses. Study of the latter is helping us understand mechanisms in the etiology and pathogenesis of inflammatory myositis and virus-induced autoimmunity.
 ...
PMID:Animal models of myopathy. 177 47

The infection of muscle is an infrequent condition. We report on a patient with a juvenile form of dermatomyositis who developed infectious myositis caused by Streptococcus pyogenes. The inflammatory myopathy probably favoured the colonization of muscle during a bacteremia related to the skin lesions. The main forms of streptococcal myositis, which can currently be differentiated by means of imaging techniques, are discussed in addition to its treatment and prognosis.
 ...
PMID:Streptococcal myositis as a complication of juvenile dermatomyositis. 182 48


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>