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)

Intravenous administration of a single dose of hydrocortisone to patients with the Duchenne type of progressive muscular dystrophy, carriers of Duchenne dystrophy gene caused a short-lasting rise of the serum creatine kinase activity. Administration of hydrocortisone also raised the serum CPK activity in some carriers with a primarly normal CPK level. This phenomenon was observed, though to a lower degree, in limb-girdle muscular dystrophy. The serum CPK activity was sometimes increased after hydrocortisone administration in patients with polymyositis and Kugelberg-Welander spinal muscular atrophy. This phenomenon was never observed in the control group or in cases of myotonic dystrophy. The mechanism of this effect of hydrocortisone on the CPK level is still unknown.
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PMID:The effect of hydrocortisone on the serum creatine kinase activity of muscles diseases. 7 11

We report specific findings in the imipramine/serotonin animal model that are consistent with sarcolemmal membrane alterations. Among these findings are cytoplasmic enzyme release, diminished uptake of alpha-aminoisobutyrate (an amino acid analog), decreased oxygen consumption in isolated rat diaphragm, and ribosuria. Furthermore, we describe for the first time the release of the MB isoenzyme of creatine kinase from a source other than cardiac tissue; that is, isolated diaphragms from imipramine/serotonin-treated animals release increased amounts of MB isoenzyme as compared to diaphragms from control animals. We believe the similarities between this animal model and the human disease (Duchenne muscular dystrophy) support a genetically determined generalized membrane abnormality in the pathogenesis of this form of muscular dystrophy.
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PMID:Sarcolemmal membrane changes related to enzyme release in the imipramine/serotonin experimental animal model. 13 59

The purpose of this study was to determine whether the previously reported differences in adenylate cyclase activity between the sarcolemma of normal and dystrophic chick muscles are also found in the SR, to search for a possible relationship between the adenylate cyclase changes and the pathophysiology of dystrophy, and to investigate whether the findings can be extended to Duchenne human muscular dystrophy by studying the adenylate cyclase and ATPase activities of erythrocyte ghosts from DMD patients and carriers. Microsomes were separated by standard techniques from the pectoralis muscles of normal and dystrophic ckeckens of various ages. The microsomal yields were significantly larger in dystrophic muscles. Adenylate cyclase activities in dystrophic microsomes were higher than those in matched controls and increased with the progression of the disease. The ratio between the two rose from one at 2 weeks of age to nine at about 9--10 weeks. Kinetic analyses showed that the ks for MgATP2- was about 40 microM (at 3 mM Mg2+ and 0.3 mM Ca2+) both in normal and dystrophic microsomes, that calcium caused umcompetitive inhibition of the enzyme (Ki = 0.2 mM), that the effect of calcium was noncooperative (Hill coefficient, nH = 1), that calcium did not affect the cooperativity for MgATP2-, and that magnesium competitively removed the calcium inhibition and caused additional, cooperative stimulation of the enzymatic activity (ka = 1.5 mM; NH =2). The major difference between normal and dystrophic adenylate cyclase was a higher enzymatic velocity in the latter, suggesting a larger amount of enzyme. We investigated whether altered cAMP levels may effect calcium accumulation. Calcium uptake measured (in the presence of oxalate) at several ages revealed no difference between normal and dystrophic chickens. The extent of calcium binding was also similar, although the kd for Ca2+ was lower in dystrophic microsomes. Binding was enhanced in the presence of exogenous protein kinase, but the responses of normal and dystrophic tissues were similar. We concluded that the elevation of adenylate cyclase in dystrophy was not related to microsomal calcium accumultion. Ivestigation of the localization of microsomal adenylate cyclase supported this view. Separation of calcium-loaded microsomes on a discontinuous sucrose gradient into four fractions demonstrated that adenylate cyclase activity, measured in the presence of Lubrol-PX and EGTA, was inversely related to calcium-accumulating activity. Na+, K+-ATPase comigrated with adenylate cyclase. Highest specific activities were found in the lightest fraction. These observations were confirmed by histochemical studies. The reaction product from adenylate cyclase activity was present predominantly in the terminal cisternae of the SR. In the context of the literature, our findings suggest that the rises in adenylate cyclase and Na+, K+-ATPase in avian dystrophy are compensatory changes, elicited by a defect in ECC at the calcium release step...
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PMID:Adenylate cyclase in muscular dystrophy. 15 10

The results are reported of single muscle fiber uptake of tritiated leucine in muscle biopsy material from Duchenne dystrophy and Charcot-Marie Tooth disease. The uptake in the two conditions is compared and suggests that the previously reported increase in synthesis of cytoplasmic proteins in muscular dystrophy are probably related to regenerative efforts by the muscle fibers.
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PMID:The incorporation of 3H (G) L-leucine into single muscle fibers in Duchenne dystrophy and Charcot-Marie Tooth disease. 26 56

We studied lymphocyte capping in 61 patients with Duchenne, Becker, limb-girdle, facioscapulohumeral and congenital muscular dystrophies. All showed a markedly diminished percentage of capped cells when compared with 86 normal controls, providing support for previous evidence that an alteration in membrane fluidity may be a common pathogenic feature in several genetically distinct forms of proximal muscular dystrophy. Heterozygous carriers of Duchenne muscular dystrophy showed diminished capping that was indistinguishable from that of afflicted males and was often present even when serum enzyme levels were normal. Studies in 25 families with 16 suspected sporadic cases indicated that no more than four out of 30 afflicted males may represent new mutations. These findings imply that most cases of Duchenne dystrophy might be prevented by a population screening program for carrier females combined with prenatal detection of afflicted males.
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PMID:Systemic membrane defect in the proximal muscular dystrophies. 30 14

A high incidence of mitral valve prolapse (MVP) has been reported in patients with X-linked Duchenne muscular dystrophy. In our study MVP was present in six of 22 Duchenne dystrophy cases (27%) followed in the Maryland General Hospital Muscular Dystrophy Clinic. In addition, seven carriers of Duchenne and X-linked benign (Becker) dystrophy had evidence of MVP. Autosomal dominant transmission of MVP was present in four families. The unusually high prevalence of MVP in families with X-linked muscular dystrophy may have potential value in the recognition of the carrier trait.
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PMID:Familial occurrence of mitral valve prolapse in X-linked muscular dystrophy. 43 21

Electrophysiologic properties of biopsied normal and diseased intercostal muscle fibers were examined using intracellular microelectrode techniques. The resting potentials of all diseased muscle fibers were found to be depolarized. Those from Duchenne dystrophy patients showed the largest depolarization, followed by those from patients with myotonic muscular dystrophy, myotonia congenita, and motor neuron disease. All of the diseased fibers except those from myotonia congenita patients demonstrated an imparied ability to generate action potentials. In the latter fibers, the higher-than-normal membrane resistance was associated with hyperexcitability. When the membrane was hyperpolarized to the normal range, however, action potential characteristics in all fibers were near normal, except in motor neuron disease. All action potentials were blocked by tetrodotoxin. These findings--i.e., that all fibers were capable of generating action potentials when hyperpolarized, and that all action potentials were blocked by tetrodotoxin--suggest the relative intactness, in the disease studied here of the regenerative sodium conductance mechanism.
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PMID:Electrophysiologic properties of intercostal muscle fibers in human neuromuscular diseases. 50 3

A unique combination of a Duchenne-like muscular dystrophy in a girl with a translocation-inversion rearrangement involving an X chromosome and a no 1 chromosome appeared as a result of both gene mutation and chromosome mutation in the mother. The X-autosome rearrangement would permit full expression of an X-linked recessive gene, such as that for Duchenne muscular dystrophy, in a female, and this would satisfactorily explain the characteristic Duchenne-like course of our patient's illness. The simultaneous de novo appearance of the Duchenne mutation and the X;1 rearrange suggests possible sites for the Duchenne locus on the X chromosome short arm (at Xp1106 or Xp2107).
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PMID:Muscular dystrophy in an X; 1 translocation female suggests that Duchenne locus is on X chromosome short arm. 51 85

Ths dissociation of gross congestive cardiomyopathy and muscle disease in different members of a family affected with Becker's benign X-linked muscular dystrophy is described. The possibility that cardiomyopathy and muscular dystrophy may be the expressions of the same mutant gene has been suggested.
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PMID:Congestive cardiomyopathy in a family of Becker's X-linked muscular dystrophy. 56 17

This is a review of clinical, cardiologic, electrophysiologic, pathologic, and serum creatine kinase changes in eight families with slowly progressive X-linked Becker-type muscular dystrophy. All but one of the patients were able to walk until the age of 16 years, and most lived beyond 20. In every family, electromyography and muscle biopsy showed features which, on the basis of classical criteria, were interpreted as those of both myopathy and denervation, although among patients and among families, one or the other of these processes predominated. The most frequent biopsy picture was of fiber atrophy and hypertrophy, with many split and angulated fibers, and clumps of pyknotic nuclei. Necrosis, phagocytosis, regeneration, endomysial fibrosis, and some fatty infiltration were commonly seen. Review of a family originally described by Becker showed a similar biopsy picture; These pathologic changes are separable from those of Duchenne muscular dystrophy, but they often overlap with those seen in other chronic neuromuscular diseases.
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PMID:Becker-type muscular dystrophy. 57 27


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