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 ultrastructural distribution of basement membrane around the capillaries as well as muscle cells of boys with Duchenne-type muscular dystrophy was determined. In dystrophic muscles, a diffuse thickness of vascular as well as muscular basement membrane was observed. Lamina densa lost its regular ribbon-like appearance and was split into several thin layers. After staining with tannic acid (TA), a densely stained meshwork was present on the muscle cell surface as well as in the extra-cellular space. Hyaluronidase treatment removed TA-stained deposits, indicating that hyaluronic acid is a major component. Enzyme resistant structures, presumably fibrous long-spacing collagen fibrils, have been found in dystrophic muscles. Based on the results of the study, faulty structure of the basement membrane in dystrophic muscle is suggested.
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PMID:An ultrastructural study of the vascular and muscular basement membrane in Duchenne-type dystrophy. 342 53

Zinc has been reported to be important in protein synthesis, collagen crosslinking, membrane structure and function, cellular necrosis, muscle glycolysis, and cardiac dysfunction. As all these processes are affected by muscular dystrophy, we studied the Zn concentrations in the cardiac and skeletal muscles of 7-month-old male dystrophic hamsters with advanced hypertrophic cardiomyopathy. Age- and sex-matched normal hamsters served as controls. Calcium, magnesium, and copper concentrations were also measured in the dystrophic and normal tissues. Flame atomic absorption spectrophotometry was used for mineral quantitation of the nitric acid tissue extracts. Zn concentrations in the myocardium (P less than 0.002), diaphragm (P less than 0.005), and rectus femoris muscles (P less than 0.001) were significantly elevated with concomitant elevations of Ca in dystrophic compared with normal hamsters. Although no appreciable changes in Cu or Mg concentrations were noted in the myocardium, slight depletions of Cu in the dystrophic diaphragm (P less than 0.025) and Mg in the dystrophic rectus femoris (P less than 0.05) were present. The intracellular Zn and Ca accumulations in the cardiac and skeletal muscles of dystrophic hamsters correlated with other dystrophic features such as increased rates of protein synthesis, significant myocardial enlargement, characteristic electrocardiographic and mechanophysiologic abnormalities, and classical histopathologic changes. We hypothesize that Zn2+ may be cotransported with Ca2+ across the cellular membrane or substituted for Ca2+ in certain pathways. These mechanisms may be affected by the high-energy ATP-pump and/or the sodium-potassium exchange system at the cellular level. Our observations suggest a possible pathogenetic involvement of Zn in muscular dystrophy which may be associated with an accelerated effort by the cellular system to repair the damaged cardiac and skeletal muscles.
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PMID:Excessive intracellular zinc accumulation in cardiac and skeletal muscles of dystrophic hamsters. 380 14

There were marked differences between the levels of collagen (measured as hydroxyproline) and mucopolysaccharides (measured as hexosamine) found in embryonic chicks with genetic muscular dystrophy and their normal controls. The chief differences were that the dystrophic tissues (gastrocnemius muscle and tendon, pectoralis major and skin) had: (a) greater amounts of hexosamine early in embryonic development; (b) hydroxyproline levels that rose at a faster rate, yielding different slopes than their normal controls; (c) relatively greater amounts of hydroxyproline than hexosamine later in embryonic life (day 20). Connective tissue systems in muscles were preferentially affected. The connective tissue system associated with dystrophic tissues appeared to lag behind the normal rhythm pattern of embryological development. The changes in connective tissue metabolism observed in dystrophic chicks suggested that the collagen from dystrophic embryonic chicks may be of a different structure or composition than that found in the normals.
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PMID:Connective tissue metabolism in muscular dystrophy. Levels of collagen and mucopolysaccharides in embryonic chickens with genetic muscular dystrophy. 623 44

Possible changes in collagen biosynthesis were studied in 50 patients with neuromuscular disorders and 14 controls. Type III procollagen aminoterminal propeptide concentrations and galactosylhydroxylysyl glucosyltransferase (GGT) activities were assayed in serum, and prolyl 4-hydroxylase and GGT activities were assayed in muscle biopsy specimens. All four assays showed significantly elevated values in cases of polymyositis, adult forms of muscular dystrophy, and amyotrophic lateral sclerosis, the concentration of muscular collagen also being significantly increased in the last two conditions. Some abnormalities were also seen in polyneuropathy, myotonia congenita, and undefined myopathy. High correlations were found among the values for the four assays, but no marked correlations with muscular collagen concentration or enzyme activities characteristic of neuromuscular disorders were found. The four assays may reflect changes in actual collagen synthesis in the diseased muscle.
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PMID:Changes in collagen metabolism in diseased muscle. I. Biochemical studies. 629 94

The activities of four lysosomal and two nonlysosomal hydrolases were studied in skeletal muscle biopsy samples from patients with neuromuscular diseases and from controls. beta-Glucosaminidase activity was increased in polymyositis. beta-Glucuronidase and alkaline protease activities were elevated in muscular dystrophy in adults, whereas cathepsin D activity was increased in amyotrophic lateral sclerosis. There were significant correlations between the activities of lysosomal and nonlysosomal hydrolases. The activity of beta-glucuronidase, beta-glucosaminidase, alkaline protease, and dipeptidyl aminopeptidase IV showed a positive correlation with the severity of muscular atrophy. The activities of these hydrolases and the activity of dipeptidyl aminopeptidase I correlated positively with the activities of muscular galactosylhydroxylysyl glucosyltransferase and with the serum concentration of type III procollagen aminoterminal propeptide. The results suggest that in neuromuscular diseases the lysosomal and nonlysosomal pathways for muscle degradation are affected concomitantly with collagen biosynthesis.
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PMID:Lysosomal and nonlysosomal hydrolases of skeletal muscle in neuromuscular diseases. 635 16

Duchenne's muscular dystrophy is inherited as a recessive X-linked trait: Even-though it rarely appears in females it can be seen. We have examined 5 children of one family. Two boys and one girl showed typical symptoms and clinical as well as light- and electronmicroscopical findings of this disease. In order to understand the mode of the genetic pattern, we have analysed the chromosomes, proved the fatherhood and assured the increased Ca-pooling in non-necrotic muscle fibers; in vitro-examinations of the amino-acid-incorporation in ribosomes and of the synthesis of collagen in muscular cells were done as well. Evaluating all of the results, the inheritance must be X-linked recessive and the girl, with high incidence, is a so called "manifesting carrier". The explanation offers Lyons hypothesis, which suggests that in most of the girl's muscle cells the X-Chromosomes, inherited from the mother, are active and lead to the manifestation of the illness. Consequences in advising the family genetically must be taken.
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PMID:[Duchenne's muscular dystrophy: also in girls?]. 671 41

To investigate the "vascular" hypothesis of muscular dystrophy, the sensitivity and contractility of aortic spiral strips of dystrophic (BIO 14.6) and normal (FIB) hamsters have been determined to various smooth muscle agonists. The results obtained with cumulative dose-response curves show that there is no increase in the sensitivity of the dystrophic compared with the normal aorta to noradrenaline, phenylephrine, isoproterenol, histamine, or 5-hydroxytryptamine. However, there was a significant increase in the force generated by aortic strips of the dystrophic animals to all agonists. Determination of noncollagen and collagen protein showed that there was no difference in the relative proportions of these proteins in the aortas from the two strains. The results show that in this animal model of dystrophy an increased response to vasopressor amines occurs and is in accordance with that expected of the vascular hypothesis.
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PMID:Increased contractility in vascular smooth muscle of dystrophic hamsters. 683 16

This paper presents an ultrastructural study of the changes occurring within the tendon and at the insertion of the developing gastrocnemius of White Leghorn chickens and the dystrophic lines 413 and 423 from Davis, CA. The study revealed that the Davis lines contained abnormalities in these areas as early as 13 d in ovo with progressive deterioration to 19 d in ovo. The fibroblasts, collagen, and myofibers showed significant alterations as early as 13 in ovo. Fibroblasts contained abnormal mitochondria and altered Golgi bodies. At day 19, many were ruptured. The average diameter of collagen fibrils was smaller in the dystrophic chickens and myofibers showed a variety of alterations, some of which were severe. The details of these alterations are described and their possible relationship with the etiology of genetic muscular dystrophy is discussed.
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PMID:Ultrastructure of the developing myotendinous junction of genetic dystrophic chickens. 685 6

The striking proliferation of connective tissue characteristic of the muscular dystrophies can be attributed predominantly to an increase in endomysial and perimysial type III collagen. Carriers of muscular dystrophy occasionally revealed a slight increase in anti-type III collagen fluorescence, but no abnormalities in collagen disposition were observed in foetuses "at risk" for DMD. In contrast, the proportion of collagen types in neurogenic atrophies appeared normal although anti-type IV and V staining, which delineated the basement membrane, was very intense around atrophied fibres, as was also the case in small fibres in myopathic diseases. The detection of staining with anti-type III, IV and V collagens in splits which are sometimes observed in hypertrophied fibres in the muscular dystrophies supports the suggestion that abnormalities in collagen production, perhaps involving a defective modulation of myoblast-fibroblast expression, may be involved in the pathogenesis of these diseases.
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PMID:Collagen types in neuromuscular diseases. 705 1

Immunofluorescence studies using specific antibodies against collagen of types I, III, IV, and V were carried out on muscle biopsy specimens from 22 patients with various neuromuscular disorders and seven controls. Increased staining with all antibodies was seen in the patients with polymyositis and muscular dystrophy. Increased staining with types I and III antibodies was found in the samples from the patients with amyotrophic lateral sclerosis in cases with an elevated concentration of muscular hydroxyproline. Two patients with amyotrophic lateral sclerosis showed no accumulation of collagen, and this was similarly true of the polyneuropathy cases. An accumulation of types IV and V collagen was typical for the myotonia congenita samples. The immunohistochemical results were in good agreement with the biochemical findings from the same patients.
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PMID:Changes in collagen metabolism in diseased muscle. II. Immunohistochemical studies. 713 17


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