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Query: UMLS:C0011633 (dermatomyositis)
 4,181 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dermatomyositis is a chronic inflammatory myopathy with severe prognosis. A 57-year-old woman suffering from dermatomyositis is presented who, in the course of the disease, developed acute spontaneous esophageal rupture due to dermatomyositis involvement of the esophagus. She was successfully treated with total esophagectomy and stomach interposition. This is the first report of spontaneous rupture of esophagus in dermatomyositis.
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PMID:Spontaneous esophageal rupture in adult dermatomyositis. 897 17

We report an interesting association of inflammatory myopathy, characterized pathologically as dermatomyositis, with bronchiolitis obliterans/organizing pneumonia and anti-histidyl-tRNA synthetase (Jo-1) antibody. The relations of different types of pulmonary involvement to inflammatory myopathy and antisynthetase antibodies are discussed.
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PMID:Inflammatory myopathy, bronchiolitis obliterans/organizing pneumonia, and anti-Jo-1 antibodies--an interesting association. 906 64

To clarify the significance of intracellular lysosomal (cathepsins B, L and H) and extralysosomal (calpain) proteolytic systems in the process of muscle fiber degradation in inflammatory myopathies, biopsied muscle specimens were examined from patients with polymyositis (PM) and dermatomyositis (DM). Generally, in specimens from patients with PM and DM, but not in those from normal controls, muscle fibers surrounding inflammatory infiltrates or in the perifascicular regions, and occasionally mononuclear cell infiltrates demonstrated positive immunostaining for calpain and cathepsins B, L, and H. In addition, enzyme activities of cathepsins B and L increased in specimens with inflammatory myopathy. These results suggest that calpain and cathepsins play a significant role in the process of muscle fiber destruction in inflammatory myopathy.
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PMID:Calpain and cathepsins in the skeletal muscle of inflammatory myopathies. 913 28

The idiopathic inflammatory myopathies are diseases of unknown etiology characterized by T cell-mediated myocytotoxicity in polymyositis and complement-mediated angiopathy of muscle fibers in dermatomyositis. A variable degree of fibrosis is present in muscles in these conditions both perimysially and endomysially. We evaluated the expression of TGF-beta 1, a pleiotropic cytokine with fibrogenic and immunomodulating activity, by means of quantitative-polymerase chain reaction and immunocytochemistry in DM and PM muscle biopsies. TGF-beta 1 mRNA was significantly higher in DM compared with controls, whereas in PM the values were not significantly different when compared with controls and DM. TGF-beta 1 was localized in connective tissue but did not correspond with mononuclear cell infiltrates. These findings suggest a correlation between TGF-beta 1 and connective tissue proliferation in inflammatory myopathy, while its immunomodulatory role remains to be elucidated.
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PMID:Transforming growth factor-beta 1 in polymyositis and dermatomyositis correlates with fibrosis but not with mononuclear cell infiltrate. 914 60

The most frequent autoimmune adult inflammatory myopathies are dermatomyositis, polymyositis, inclusion body myositis, and sarcoid myopathy. Interleukin-1 (IL-1) is a pleiotropic molecule, implicated in the inflammatory process, but also in tissue protection and remodelling. We evaluated the immunocytochemical expression of [L,-1alpha and beta in frozen muscle biopsy specimens from patients with dermatomyositis (15 cases), polymyositis (five cases), inclusion body myositis (five cases) and sarcoid myopathy (five cases). Positive immunoreactivities, were observed in both inflammatory cells and muscle fibres. Specificity of the immunostaining was assessed by Western blot experiments. IL-1 positive inflammatory cells were rare in polymyositis and inclusion body myositis, moderately abundant in dermatomyositis, and prominent in sarcoid myopathy granulomas. In sarcoid myopathy, 24.6 +/- 4.1% inflammatory cells were IL-1alpha-positive and 45.2 +/- 2.6% were IL-1beta-positive. IL-1 positive muscle fibres were mainly observed in dermatomyositis, usually remote from inflammatory infiltrates. Positive immunostaining for IL-1 was observed in fibres showing ischaemic punched-out vacuoles, that correspond to areas of myosinolysis, in atrophic perifascicular fibres, and in fibres located within healing microinfarcts. All NCAM-positive regenerating fibres were IL-1 positive. We conclude that: (i) IL-1 is expressed in granulomas of sarcoid myopathy, which is in keeping with the role ascribed to IL-1 in the formation of granulomas: (ii) IL-1 is expressed by muscle fibres undergoing ischaemic damage: and (iii) IL-1 expression by muscle fibres is associated with myofibrillar protein breakdown and regeneration.
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PMID:Interleukin-1 expression in inflammatory myopathies: evidence of marked immunoreactivity in sarcoid granulomas and muscle fibres showing ischaemic and regenerative changes. 916 Aug 98

Dermatomyositis, polymyositis, and inclusion body myositis are the major categories of idiopathic inflammatory myopathy. These inflammatory myopathies are distinct clinically, histologically, and pathogenically. Features of dermatomyositis and polymyositis can overlap with those of other autoimmune connective tissue diseases. In this article, the authors review the characteristic features of these myopathies, update the recent developments in this area, and provide a framework for treatment.
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PMID:Idiopathic inflammatory myopathies. 922 56

A large number of intellectually engaging and potentially serious neuromuscular diseases have been presented. The emergency medicine physician must be able to recognize those entities that have the potential to clinically deterioration. The evaluation of weakness requires a comprehensive, broad-based differential that is driven by the history and physical. Diagnostic testing is determined by the clinical suspicion as is the urgency for further work-up. The following are the final diagnoses of the eight illustrative cases that were presented at the beginning of this article. Case 1. This unfortunate woman had a metabolic myopathy that was only diagnosed after enzymatic analysis of a muscle biopsy. Her genetic defect, carnitine palmitoyltransferase deficiency, is unusual as it does not present until late in adolescence or slightly later in life. It is a defect in lipid metabolism in which long-chain fatty acids are unable to gain entrance into the mitochondrion for oxidative degradation. The defect is apparent only after prolonged exercise or fasting. In this patient, rhabddomyolysis led to acute renal failure that resolved without requiring temporary dialysis. Case 2. This patient had an elevated CPK-MM. Her EMG showed myopathic changes and her nerve conduction studies were normal. She had a positive test for antinuclear antibodies. A biopsy of her quadriceps muscle revealed lymphocytic infiltration of the muscle fibers that showed some focal myocyte degeneration. The diagnosis of dermatomyositis was made based on the findings noted previously and the heliotrope hue of her periorbital skin. A search for an occult neoplasm was negative. She responded moderately to a course of high-dose prednisone. Case 3. The laboratory test that confirmed this diagnosis was the potassium of 2.4 mEq/L. The remainder of the electrolytes were normal. Infusion of 20 mEq of potassium over 2 hours led to a prompt return of normal muscle strength. The final diagnosis was hypokalemic periodic paralysis. In this disease there is an inherited defect in the ability of the myocyte to maintain a normal transmembrane potential. The defect is latent until there is a precipitating factor, such as an high carbohydrate meal or prolonged immobility. There is also a form seen with thyrotoxicosis and is essentially cured when the patient becomes euthyroid. The disease is seen most frequently in Asian males, although it is reported in most ethnic groups. Prophylaxis in these patients is with acetazolamide which raises the serum potassium indirectly by causing a metabolic acidosis. Triamterene and spironolactone have also been successfully used on occasion. This patient turned out to have thyrotoxicosis as well. Case 4. This man had both cranial motor and peripheral muscular dysfunction. There was no evidence of nonmotor cranial nerve dysfunction, nor was there evidence of any peripheral sensory deficits. The diagnosis of myasthenia gravis was established by the rapid and transient response of this patient to 2 mg of edrophonium. He was found to have antiacetylcholine receptor antibodies and was also thyrotoxic. He had a stormy course requiring intubation and prolonged ventilation. Eventually, he underwent thymectomy and is stable on pyridostigmine. Case 5. Initially suspected to be hysteria, this patient and his relatives had botulism from home-canned peppers. The index case required prolonged intubation and ventilation. The patients were treated with polyvalent antiserum and gastric lavage to remove the residual contaminated food which was still in their stomachs due to the gastric atony seen with this disease. The botulinus toxin prevents the release of acetylcholine molecules from their storage vesicles in nerve terminals. Thus, this disease is the opposite of the cholinergic syndrome seen with organophosphate insecticide poisonings except that cognitive functioning is not impaired in botulism. Case 6. This is a celebrated case that took a great deal of sleuthing
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PMID:Approach to generalized weakness and peripheral neuromuscular disease. 925 35

Distinction of inclusion body myositis (IBM) from other forms of inflammatory myopathy is significant from prognostic and therapeutic standpoints. This study retrospectively examines ubiquitin expression by paraffin immunohistochemistry in muscle biopsy material from 30 patients with IBM. Patients included 19 men and 11 women (ages 29 to 80 years; mean, 64 years). All biopsies were characterized by endomysial chronic inflammation, muscle fiber degeneration and regeneration, rimmed vacuoles, and angular atrophic esterase-positive muscle fibers. Ragged red fibers were identified in biopsies of five patients and a partial cytochrome C-oxidase deficiency by enzyme histochemistry in biopsies of 10 patients. Evidence of intranuclear or cytoplasmic tubulofilamentous structures confirming a diagnosis of IBM was observed in all 30 cases. Paracrystalline mitochondrial inclusions were noted in five patients. Discrete myocyte intranuclear ubiquitin-positive inclusions were noted in 14 patients (47%). Discrete intracytoplasmic ubiquitin-positive inclusions were noted in 24 (80%) patients. Positive staining of rimmed vacuoles by ubiquitin was observed in 25 (83%) patients. Diffuse staining of scattered muscle fibers was observed in 21 (70%) patients. In a control group including patients with polymyositis (n = 3), dermatomyositis (n = 3), necrotizing vasculitis (n = 1), and granulomatous myositis (n = 1), discrete intranuclear or cytoplasmic ubiquitin-positive inclusions were not observed. Rimmed vacuoles were not seen either by light microscopy or ubiquitin immunostaining in any of the eight cases. Occasional myofibers from all eight cases showed diffuse, positive muscle fiber staining. Although not present in all cases, evidence of ubiquitin-positive myocytic intranuclear or cytoplasmic inclusions or positive-staining rimmed vacuoles in the setting of an inflammatory myopathy may be suggestive of a diagnosis of inclusion body myositis. Use of ubiquitin immunohistochemistry may be useful in cases in which frozen tissue or tissue processed for electron microscopy is not available, and IBM is suspected. Light or electron microscopic evidence of mitochondrial abnormalities were noted in a significant subset of patients (13 of 30; 43%) of patients with IBM.
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PMID:Ubiquitin immunostaining and inclusion body myositis: study of 30 patients with inclusion body myositis. 926 23

Histological features of neurogenic muscle involvement include type grouping, muscle fiber atrophy and target fibers. In zidovudine-induced myopathy and dermatomyositis, immunoreactivity for interleukin (IL)-1 has been reported in diseased muscle fibers involving myofibrillar breakdown and atrophy. Since IL-1 is a signal for muscle proteolysis, we studied myofiber expression of IL-1 in neurogenic muscle involvement, specially in atrophic myofibers and target fibers which are associated with myofilament breakdown. Muscle biopsy samples from patients with normal (5 cases) or neurogenic muscle involvement (25 cases) were studied by enzyme histochemistry and immunohistochemistry. In normal muscles, immunoreactivity for IL-1beta was restricted to the postsynaptic domain of motor endplates and that for IL-1alpha had a similar localization but was faint. Immunoreactivity for IL-1alpha and -beta was observed, respectively, in 42.5% and 75.5% of target fibers, in 8.5% and 10.4% of dark angulated fibers, in 0% and 0.3% of non-atrophic type-grouped fibers, in 14.2% and 16.5% of moderately atrophic fibers, and in 65% and 20.9% of severely atrophic fibers. Immunoblot study showed the presence of both proIL-1 (31 kDa) and mature IL-1 (17.5 kDa). From this study, we conclude that IL-1 is normally expressed in the muscular domain of neuromuscular junctions; that IL-1 is mainly expressed in neurogenic target fibers; and that IL-1 expression by muscle fibers in pathological conditions seems to be associated with myofibrillar protein breakdown and regeneration.
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PMID:Interleukin-1 expression in normal motor endplates and muscle fibers showing neurogenic changes. 929 97

Inasmuch as the clinical features of the idiopathic inflammatory myopathies are not easily differentiated from those of other similar rheumatic and neurologic conditions, diagnosis is often difficult. Various classification criteria for polymyositis and dermatomyositis have been suggested by a number of investigators. The most commonly accepted and used criteria include symmetric proximal muscle weakness, serum elevations of muscle enzymes, the classic electromyographic and muscle biopsy findings of inflammatory myopathy, and the typical skin rash of dermatomyositis. Although these criteria are clinically useful, they can result in misdiagnoses and inappropriate therapies. They also result in heterogeneous patient groups being selected for clinical and laboratory studies. Furthermore, they do not include recent findings related to the myositis-specific autoantibodies and magnetic resonance imaging of muscle that have been found to be important adjuncts in assessing patients with muscle weakness or elevations of muscle enzymes. A modification to the Bohan and Peter criteria is proposed to include myositis-specific autoantibodies and magnetic resonance imaging. This proposal could initiate productive discussions and investigations of the sensitivity and specificity of new classification criteria for myositis and could ultimately enhance our treatment capabilities.
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PMID:Classification criteria for the idiopathic inflammatory myopathies. 937 82


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