Abstract In 76 muscle specimens (normal controls, 9; Duchenne dystrophy, 11; scleroderma, dermatomyositis, 13; polymyositis, 15; inclusion body myositis, 17), mononuclear cells were analyzed at perivascular, perimysial, and endomysial sites of accumulation. Monoclonal antibodies reactive for B cells, T cell subsets, killer (K) or natural (NK) the Ia antigen used typing. Macrophages identified by acid phosphatase reaction. Few extravascular occurred in normal muscle. all inflammatory...

SUMMARY Inclusion body myositis (IBM) was suspected on light microscopic grounds in 48 of 170 consecutive patients with inflammatory myopathies. One or more vacuoles containing membranous material, groups atrophic fibres, and an autoaggressive endomysial exudate occurred 100, 96 92% the muscle specimens All three these features were present 88% Electron microscopy confirmed presence filamentous inclusions 40 43 The are typically near a minimum vacuolated fibres must be scrutinized to detect...

In a rare myopathy muscle fibers contained myriad lipid-filled vacuoles. Homogenates of the patient's oxidized fatty acids more slowly than normal (11 controls). Addition carnitine increased oxidation rate with to level attained by controls carnitine. five separate samples from patient mean was less 20 percent that observed in 42 controls. Carnitine palmityl transferase and thiokinase levels muscles were not depressed. The present case represents first recognized instance deficiency human...

In seven patients with Duchenne dystrophy, high-resolution phase microscopy demonstrated a population of non-necrotic fibers one or more focal lesions. The typical lesion was wedge-shaped, the base resting on fiber surface. electron microscope, plasma membrane overlying either absent disrupted, while basement always preserved. Within lesion, there were cytoplasmic abnormalities, and in neighboring region, myofibrils usually highly contracted. structural defect suggested that this site an...

Abstract In adult dermatomyositis 10 muscle specimens with no or minimal histological alterations were compared 7 that showed typical alterations. Five from patients inclusion body myositis, 5 polymyositis, and 8 normal subjects served as controls. Vascular endothelium, visualized the lectin Ulex europaeus agglutinin I, complement membrane attack complex demonstrated in same cryostat sections by paired immunofluorescence. Large randomly selected fields analyzed to determine number of...

An 11 -year-old boy had recurrent episodes of hepatic and cerebral dysfunction underdeveloped musculature. Overt weakness developed at age 10. Lipid excess, especially in type I fibers, was found muscle. Hypertrophied smooth endoplasmic reticulum excessive microbodies were present liver. Marked carnitine deficiency shown skeletal muscle, plasma, Ketogenesis impaired on a high fat diet, but omega oxidation fatty acids enhanced. There glucose uptake essentially no labeled long-chain by...

Ultrastructural studies have shown plasmalemmal defects in a proportion of non-necrotic muscle fibers Duchenne dystrophy, suggesting that intracellular calcium overloading may be an important mechanism fiber degeneration. To investigate this assumption, we studied the localization with von Kóssa method, alizarin red, and glyoxalbis-(o-hydroxyanil) serial, fresh-frozen sections 114 biopsy specimens. The material included dystrophy (24 cases), other dystrophies (27 inflammatory myopathies (47...

The electron transport system of muscle mitochondria was examined in a familial syndrome lactacidemia, mitochondrial myopathy, and encephalopathy. propositus, 14-year-old female, her 12-year-old sister had suffered from progressive weakness, abnormal fatigability, central nervous dysfunction since early childhood. In the state 3 respiratory rate with NADH-linked substrates succinate markedly reduced. levels cytochromes + a3, b, c c1 were normal. activities complexes I, II, III, IV chain...

Abstract In 6 cases of polymyositis and inclusion body myositis, phenotypes mononuclear cells focally surrounding invading muscle fibers were analyzed. By localizing the T8, T4, Ia markers with direct immunofluorescence acid phosphatase enzyme cytochemically in same sections, five different simultaneously identified a given section: T8 + T4 that either activated (Ia ) or not − ), phosphatase—reactive macrophages. This approach permitted separate quantitative assessment distributions among...

Myofibrillar myopathies (MFMs) are morphologically distinct but genetically heterogeneous muscular dystrophies in which disintegration of Z disks and then myofibrils is followed by ectopic accumulation multiple proteins. Cardiomyopathy, neuropathy, dominant inheritance frequent associated features. Mutations alphaB-crystallin, desmin, myotilin, Zasp, or filamin-C can cause MFMs were detected 32 85 patients the Mayo MFM cohort. Bag3, another Z-disk-associated protein, has antiapoptotic...

In the Lambert-Eaton myasthenic syndrome (LEMS), there is a decreased release of acetylcholine quanta from nerve terminal by impulse. Recently, an autoimmune origin LEMS was documented passive transfer its electrophysiologic features man to mouse with IgG. Freeze-fracture electron microscopy neuromuscular junctions has revealed paucity presynaptic membrane active zones. Thus, zones might be targets pathogenic autoantibodies in LEMS. To test this assumption, freeze-fracture microscopic...

<b><i>Background and Objective:</i></b> The term myofibrillar myopathy (MFM) is a noncommittal for pathologic pattern of dissolution associated with accumulation degradation products ectopic expression multiple proteins. Ultrastructural studies implicate the Z-disk as site initial change, mutations in two Z-disk-related proteins, desmin αB-crystallin, have been identified minority patients MFM. authors' objective was to determine whether myotilin, key component disease protein limb-girdle...

Choline acetyltransferase (ChAT; EC 2.3.1.6 ) catalyzes the reversible synthesis of acetylcholine (ACh) from acetyl CoA and choline at cholinergic synapses. Mutations in genes encoding ChAT affecting motility exist Caenorhabditis elegans Drosophila , but no CHAT mutations have been observed humans to date. Here we report that cause a congenital myasthenic syndrome associated with frequently fatal episodes apnea (CMS-EA). Studies neuromuscular junction this disease show stimulation-dependent...

Abstract Five familial cases (in two families) and one sporadic case of a new congenital myasthenic syndrome were investigated. Symptoms arise in infancy or later life. Typically, finds selective involvement cervical, scapular, finger extensor muscles, ophthalmoparesis, variable other muscles. There is repetitive muscle action potential to single nerve stimulus all muscles decremental response at 2 3 Hz stimulation clinically affected Microelectrode studies reveal markedly prolonged...

Abstract Myofibrillar myopathy (MFM) is a morphologically distinct disorder in which disintegration of the Z‐disk and then myofibrils followed by abnormal accumulation multiple proteins. Mutations desmin, αB‐crystallin, myotilin, all Z‐disk–related proteins, cause MFM minority cases. ZASP (a Z‐band alternatively spliced PDZ motif‐containing protein) another Z‐disk–associated protein, targeted deletion mouse causes skeletal cardiac myopathy. We therefore searched for mutations 54 patients...

To correlate muscle biopsy findings with prebiopsy and postbiopsy clinical course response to therapy in polymyositis (PM) sporadic inclusion body myositis (IBM).Existence of pure PM has recently been questioned; subsequently, the definition criteria for diagnosing were debated.Patient records, follow-up information, biopsies analyzed 107 patients whose initially read as IBM.The fell into three groups by combined criteria: PM, 27 patients; IBM, 64 PM/IBM, 16 diagnosis but features IBM. For...

In a congenital myasthenic syndrome with severe endplate myopathy, patch-clamp studies revealed markedly prolonged acetylcholine receptor (AChR) channel openings. Molecular genetic analysis of AChR subunit genes demonstrated heterozygous adenosine-to-cytosine transversion at nucleotide 790 in exon 8 the epsilon-subunit gene, predicting substitution proline for threonine codon 264 and no other mutations entire coding sequences encoding alpha, beta, delta, epsilon subunits. Genetically...