Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026850 (muscular dystrophy)
 5,870 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The time courses of changes in amplitudes of muscle action potentials (MAPs) obtained from gastrocnemius and soleus muscles by 5 Hz prolonged tibial nerve stimulation were studied. Subjects included muscular dystrophy (MD), spinal muscular atrophy, Issacs syndrome, idiopathic muscle spasms, psychiatric disorders such as autism and schizophrenia, and normal controls. In normal subjects, MAPs obtained at 5 minutes from gastrocnemius muscles was 87-102% of those at initiation of the stimulation. In soleus muscles, MAPs at 5 minutes was 95-105% of those at the beginning. In gastrocnemius muscles, MAPs increased in disorders such as Duchenne MD, Fukuyama type congenital MD, facioscapulohumeral MD, myotonic dystrophy, dermatomyositis, Kugelberg-Welander syndrome, viral myelitis, malignant hyperpyrexia, autism and schizophrenia. In soleus muscles, the increase of MAPs was demonstrated in Duchenne MD, Fukuyama type congenital MD, myotonic dystrophy and autism. MAPs remained within normal range in infants with Werdnig-Hoffman disease, Issacs syndrome and idiopathic muscle spasms. In two cases with Duchenne MD, MAPs obtained from gastrocnemius muscles reduced in amplitudes by the administration of dantrolen sodium. While the pathogenesis of the increased MAPs is not clear, several possible factors are discussed. It is considered that this 5 Hz examination may provide an important information for detecting the effect of dantrolen sodium on Duchenne MD, and it is also suggested that the examination will be a useful test for finding latent malignant hyperpyrexia.
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PMID:Increased muscle action potentials by 5 Hz prolonged nerve stimulation in neurological and neuromuscular disorders--clinical usefulness for detecting underlying pathophysiology. 648 78

Tears from myotonic muscular dystrophy (MMD) patients and normal controls were analyzed for their tear proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Lactoferrin comprised about 18% of the total tear protein in MMD patients as opposed to about 27% in normals. The albumin content relative to total protein in MMD tears was about 25% while the same value for normals is 13%. The lactoferrin/albumin ratio, was about 0.8 for MMD patients and about 2.1 for normals.
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PMID:Decrease of lactoferrin concentration in the tears of myotonic muscular dystrophy patients. 665 10

Potassium and sodium ion-selective microelectrodes were used in vitro to investigate the depolarization of skeletal muscle fibers associated with muscular dystrophy. In dystrophy there was a large increase of intracellular Na activity and an associated decrease in K activity in fibers of extensor digitorum longus muscles. Despite this, the recorded membrane potential was very close to the calculated potassium equilibrium potential (Ek) in dystrophic fibers. In contrast, in normal muscle fibers, Em was significantly depolarized with respect to Ek. The data suggest that in dystrophic fibers there is an increase in the relative membrane permeability to potassium over sodium.
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PMID:Intracellular activity of sodium in normal and dystrophic skeletal muscle from C57BL/6J mice. 669 62

Three experiments were carried out with male broiler chickens reared from day- old to 6 weeks of age on semi-purified diets containing 10% fresh (Expt. 1 and 3) or oxidized (Expt. 2) re-esterified triglycerides with a fatty acid composition similar to that of soya bean oil containing increasing concentrations of either a mixture of d-alpha-, gamma-, delta-tocopherylacetate (d-tocopherols) of natural source or dl-alpha- tocopheryl acetate (dl-tocopherol). In Expt. 1 and 2 the mixture of d-tocopherols consisted of 35.7% d-alpha-, 45.3% d-gamma- and 19.0% d-delta-, while in Expt. 3 the distribution was 25.3% d-alpha-, 28.1% d-gamma- and 10.8% d-gamma- in 35.8% re-esterified triglycerides. The relative biopotency of d-alpha-: gamma-: delta-tocopherol was anticipated to be 100:25:1, whereas that of dl-alpha-tocopherol was 74% relative to d-alpha-tocopherol. The experiments demonstrate that the results obtained for the biological activity depend on the response parameters chosen. With respect to gain in weight, feed conversion, relative organ weight, packed cell volume (PCV), ELP (erythrocyte lipid peroxidation), plasma activities of glutamate-oxaloacetate-transaminase (GOT), creatine kinase (CK) and glutathione peroxidase (GSH-Px) and plasma Na+ concentration, the mixture of natural source tocopherols was identical to that of dl-alpha-tocopheryl acetate, although the concentration of alpha-tocopherol was only about one third of that of dl-alpha-tocopherol. Differences between natural source and synthetic tocopherols were expectedly observed with respect to plasma concentrations of alpha-, gamma-, delta-tocopherol. Differences between the two forms as to muscular dystrophy, in vitro haemolysis and potassium concentration in plasma were ambiguous. It is suggested that the function of d-alpha-, gamma-, delta-tocopherol in erythrocyte fragility and skeletal muscle structure should be compared to that of dl-alpha-tocopherol in future investigations.
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PMID:The biological activity of natural source tocopherols in chickens fed fresh or oxidized fat rich in linoleic acid. 821 3

Recent evidence suggests that cellular sodium regulation may be abnormal in muscular dystrophy. We have measured intracellular sodium concentration (Nai) in muscles of mdx mice (a model of Duchenne muscular dystrophy) using two techniques. Nai in isolated diaphragm (measured using a microelectrode) was 13.0 +/- 0.3 mM and 23.5 +/- 0.7 mM (mean +/- SE) in the control and mdx mice respectively. Nai in gastrocnemius muscle (calculated from extra- and intracellular volumes using serum and whole-muscle sodium concentrations) was 13 +/- 3 mM and 24 +/- 2 mM (mean +/- SE) in control and mdx, respectively. We argue that this abnormality in mdx tissues could reflect a reduced flux through the Na/K ATPase, although a contribution from increased Na leak cannot be ruled out. We also discuss possible consequences of an increased Nai: for example, raised Nai may lead to defective cell volume control in Duchenne dystrophy and the mdx mouse.
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PMID:Sodium is elevated in mdx muscles: ionic interactions in dystrophic cells. 843 2

Dystrophin serves a variety of roles at the cell membrane through its associations, and defects in the dystrophin gene can give rise to muscular dystrophy and genetic cardiomyopathy. We investigated localization of cardiac dystrophin to determine potential intracellular sites of association. Subcellular fractionation revealed that while the majority of dystrophin was associated with the sarcolemma, about 35% of the 427-kDa form of dystrophin was present in the myofibrils. The dystrophin homolog utrophin was detectable only in the sarcolemmal membrane and was absent from the myofibrils as were other sarcolemmal glycoproteins such as adhalin and the sodium-calcium exchanger. Extraction of myofibrils with KC1 and detergents could not solubilize dystrophin. Dystrophin could only be dissociated from the myofibrillar protein complex in 5 M urea followed by sucrose density gradient centrifugation where it co-fractionated with one of two distinctly sedimenting peaks of actin. Immunoelectron microscopy of intracellular regions of cardiac muscle revealed a selective labeling of Z-discs by hystrophin antibodies. In the genetically determined cardiomyopathic hamster, strain CHF 147, the time course of development of cardiac insufficiency correlated with an overall 75% loss of myofibrillar dystrophin. These findings collectively show that a significant pool of the 427-kDa form of cardiac dystrophin was specifically associated with the contractile apparatus at the Z-discs, and its loss correlated with progression to cardiac insufficiency in genetic cardiomyopathy. The loss of distinct cellular pools of dystrophin may contribute to the tissue-specific pathophysiology in muscular dystrophy.
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PMID:The association of cardiac dystrophin with myofibrils/Z-disc regions in cardiac muscle suggests a novel role in the contractile apparatus. 864 39

The WW domain is a structured protein module found in a wide range of regulatory, cytoskeletal, and signaling molecules. Its ligands contain proline-rich sequences, some of which show a core consensus of XPPXY that is critical for binding. In order to gain a better understanding of the molecular and biological functions of WW domains, we decided to predict their cognate ligands by searching databases for proteins containing the XPPXY consensus. Using several axioms that take into account evolutionary conservation and functional similarity, we have identified four groups of proteins representing candidate ligands that signal through known or unknown WW domains. These include viral Gag proteins, sodium channels, interleukin receptors, and a subgroup of serine/threonine kinases. In addition, we proposed that dystrophin and beta-dystroglycan bind through the WW-XPPXY link and that interference with this interaction could result in muscular dystrophy. Our study provides guidelines for experiments to probe the molecular and biological functions of the WW domain-ligand connection. Should these predictions be proven empirically, the results may have important ramifications for basic research and medicine.
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PMID:Towards prediction of cognate complexes between the WW domain and proline-rich ligands. 879 92

Hemolytic anemia developed in a male who had been diagnosed as having myotonic muscular dystrophy (MMD). His red cell life-span examined by 51Cr-labeling method was shortened (T 1/2 = 6.5 days). Specific abnormalities of red cells were not found other than increased osmotic resistance, increased intracellular sodium, and decreased intracellular potassium of red cells. A clinical review of 18 other patients with MMD did not reveal any signs of hemolysis. It may be suggested that the underlying red cell membrane defects due to MMD contributed to this rare association with hemolysis.
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PMID:Hemolytic anemia associated with myotonic muscular dystrophy. 891 5

This report describes a 13-month-old-girl with Duchenne's muscular dystrophy (DMD) who had radical repair for tetralogy of Fallot safely. Patients with DMD are considered to be at risk of malignant hyperthermia (MH). Drugs for induction and maintenance were chosen from a list of agents rarely associated with MH. To wash out the inhalation anesthetics from the equipment, oxygen was circulated continuously for 24 hours. Dantrolene sodium was kept readily available in case of MH occurrence. Differential diagnosis during surgery is difficult in term of the episodes of MH and complications of cardiac surgery, as cardiac surgery is also associated with tachycardia, tachyarrhythmias, metabolic asidosis and red colored urine, which are frequently accompanied by MH. Although increased levels of CK, GOT, LDH and myoglobin strongly support the diagnosis of MH, such evidence can only be confirmed after operation. Fortunately, these factors recovered to the normal range without treatment by dantrolene sodium. During the cardiac surgery, treatment of MH may be delayed due to its late confirmation.
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PMID:[Anesthetic management of a patient with Duchenne's muscular dystrophy undergoing radical repair for tetralogy of Fallot]. 945 83

The C57 BL/6J dy2J/dy2J dystrophic mouse expresses an abnormal truncated form of the alpha2 subunit of the protein laminin-2 (or merosin), which is unable to form a stable link between the extracellular matrix and the dystrophin-associated proteins, resulting in muscular dystrophy. Morphological abnormalities of the peripheral nervous system and neuromuscular junction have also been reported. The electrophysiological properties of the neuromuscular junctions of diaphragm, extensor digitorum longus (EDL), and soleus from C57 BL/6J dy2J/dy2J mice and controls are described. No evidence for the presence of denervated fibres were found. Mean MEPP amplitudes were significantly increased in EDL and soleus but reduced in the diaphragm from affected mice. Mean MEPP frequencies were raised in all the dy2J/dy2J muscles studied. dy2J/dy2J muscles were paralysed by low concentrations of mu-conotoxin suggesting that embryonic (tetrodotoxin and mu-conotoxin resistant) sodium channels are not widespread on dy2J/dy2J muscle as has previously been reported. EPP latencies were significantly prolonged in the diaphragm and EDL but not soleus from dy2J/dy2J mice. Quantal contents were higher in all dy2J/dy2J muscles. In the dy2J/dy2J diaphragm failures in neurotransmission occurred and a faster rate of rundown of EPPs were apparent. Some changes appear from a direct effect of dystrophy, whilst increased MEPP frequency and quantal content, and failures in neurotransmission indicate neuronal abnormalities.
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PMID:Electrophysiology of the neuromuscular junction of the laminin-2 (merosin) deficient C57 BL/6J dy2J/dy2J dystrophic mouse. 955 49


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