Preservation of in vitro muscle fiber function in dermatomyositis and inclusion body myositis: a single fiber study
Autor: | Anthony A. Amato, Lisa S. Krivickas, Walter R. Frontera, Angelique V. Murray, Gomathi Krishnan |
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Rok vydání: | 2004 |
Předmět: |
Adult
Male Pathology medicine.medical_specialty Biopsy Muscle Fibers Skeletal In Vitro Techniques Biceps Dermatomyositis Myositis Inclusion Body Reference Values Isometric Contraction medicine Humans Myopathy Muscle Skeletal Genetics (clinical) Myositis Aged Aged 80 and over Specific force Muscle biopsy medicine.diagnostic_test business.industry Muscle weakness Anatomy Organ Size Middle Aged medicine.disease Neurology Pediatrics Perinatology and Child Health Physical Endurance Female Neurology (clinical) Inclusion body myositis medicine.symptom business |
Zdroj: | Neuromuscular disorders : NMD. 15(5) |
ISSN: | 0960-8966 |
Popis: | Five patients with untreated dermatomyositis, five with inclusion body myositis, and 16 healthy elderly volunteer subjects (controls) underwent open (dermatomyositis and inclusion body myositis) or percutaneous (controls) muscle biopsy. Biopsied muscles included deltoid, biceps and vastus lateralis. Chemically skinned single muscle fibers were activated with Ca(+2); the slack test was performed to determine maximal unloaded shortening velocity (Vo). Parameters measured include single fiber cross sectional area, maximal force, specific force and Vo. 429 Type I and 94 Type IIA fibers were studied. Cross sectional area and maximal force were greater in inclusion body myositis than dermatomyositis or control for Type I and IIA fibers. Specific force of Type I fibers was similar in inclusion body myositis and dermatomyositis but greater than in controls. Vo was greater in Type I, but not IIA, fibers in dermatomyositis compared with inclusion body myositis and controls. The force and velocity generating capacity of single muscle fibers is preserved in patients with dermatomyositis and inclusion body myositis suggesting that dysfunction of the contractile proteins does not contribute to clinical muscle weakness. |
Databáze: | OpenAIRE |
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