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Query: UMLS:C0026850 (muscular dystrophy)
 5,870 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We present a family in which the differential diagnosis between X linked Duchenne muscular dystrophy and autosomal recessive Duchenne-like muscular dystrophy was resolved in favour of the latter by analysis of dystrophin, which is the protein product of the Duchenne muscular dystrophy locus.
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PMID:Dystrophin analysis in the diagnosis of muscular dystrophy. 268 33

In the preceding paper a sensitive Western blotting analysis system based on the use of a monoclonal antibody to dystrophin was described. Here we report the immunoreactivity on blots and on unfixed frozen sections of muscle from patients with Duchenne (DMD) and Becker (BMD) muscular dystrophy. Muscle from 3 BMD patients showed variation both in the band pattern observed on blots and in the immunocytochemical labelling of dystrophin on frozen sections. In contrast to previous reports, we were able to detect some minor dystrophin bands on blots from 6 of 9 DMD biopsy samples. Tissue sections from 8 of the 9 contained isolated fibres with dystrophin-positive labelling. We conclude that the majority of DMD patients have muscle fibres which can synthesize dystrophin in a limited manner.
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PMID:Dystrophin in skeletal muscle. II. Immunoreactivity in patients with Xp21 muscular dystrophy. 269 18

DNA samples from nine previously reported patients with X-linked recessive glycerol kinase deficiency, associated in seven of them with adrenal hypoplasia and in five with developmental delay and myopathy, have been studied for deletions of the Duchenne/Becker muscular dystrophy gene by probing with the entire cDNA for the dystrophin protein. All five patients with myopathy, including two in whom no deletions had been detected before, were found to have variable-sized deletions extending through the 3' end of this gene. The 5' deletion breakpoints are intragenic in four cases and have been mapped precisely on the exon-containing HindIII fragment map. A correlation was found between severity and progression of the muscular dystrophy phenotype and the sizes of the gene deletions. In cases in which there was glycerol kinase deficiency/adrenal hypoplasia microdeletion syndrome without myopathy, no deletions were found with the dystrophin cDNA.
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PMID:Myopathy in complex glycerol kinase deficiency patients is due to 3' deletions of the dystrophin gene. 284 Aug 18

We have used elevated levels of plasma creatine phosphokinase activity to identify muscular dystrophy phenotypes in mice and to screen the progeny of chemical mutagen-treated male mice for X chromosome-linked muscular dystrophy mutations. We were not successful in identifying heterozygous carriers of these induced muscular dystrophy mutations in greater than 8000 progeny. However, we were highly successful in identifying three additional alleles of the characterized mdx locus. These alleles of mdx were recovered from various mutagen-treated males and they occur on an X chromosome that carries flanking markers that allow us to follow the mutations in genetic crosses and in the development of corresponding mutant stocks. These alleles have been designated as mdx2Cv, mdx3Cv, and mdx4Cv. Preliminary data show that mice with mdx2Cv and mdx3Cv mutations have muscular dystrophic phenotypes that do not grossly differ from the characterized mdx mutation. These additional mdx mutations expand the value of mouse models of X chromosome-linked muscular dystrophy and potentially define additional sites of mutation that impair dystrophin expression.
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PMID:Recovery of induced mutations for X chromosome-linked muscular dystrophy in mice. 291 77

Skeletal muscle from patients with 5 different forms of muscular dystrophy and from 6 fetuses at high risk (95%) for Duchenne muscular dystrophy (DMD) were probed with specific antibodies for the presence of dystrophin and nebulin. Dystrophin was absent in all 5 patients with DMD and 4 of 6 fetuses at high risk for DMD and present in trace amounts in the remaining two. Dystrophin was also undetectable in one borderline DMD/Becker muscular dystrophy (BMD) case and reduced in 2 of 4 cases of BMD. In contrast, dystrophin was present in all 16 biopsies from 4 other types of muscular dystrophy (congenital, limb girdle, Emery-Dreifuss and facioscapulohumeral). Nebulin profiles varied with the type, severity and duration of the dystrophic process. Nebulin was present in 5 of 6 DMD fetal samples but vastly reduced or absent in all samples of clinically manifest DMD.
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PMID:Dystrophin and nebulin in the muscular dystrophies. 306 33

Ultrastructurally there are some clear differences in the pathology of muscle in X chromosome-linked muscular dystrophy of the mouse (mdx) and Duchenne muscular dystrophy (DMD). In particular the mouse muscle does not become infiltrated by large aggregations of connective tissue. It has been proposed that the differences are due to secondary biochemical changes consequent on the absence of dystrophin in both conditions. If this is the case, attention should be directed to the earliest ultrastructural changes held in common by both disorders. The most conspicuous of these, preceding myofibril breakdown, is dilation of the sarcoplasmic reticulum. Any physiological link between this and the absence of dystrophin remains to be determined. We suggest that in the mdx mouse, the widespread myofibre necrosis occurring at 3-4 weeks is triggered by increased mechanical demands causing the lack of dystrophin to become critical at this time. Subsequent regeneration of the myofibres appears to be almost completely successful. The ultimate failure of regeneration in DMD, in contrast, may be due to an additional factors acting in DMD exacerbating the lack of dystrophin. This additional factor may be associated with the plasma membrane lesions (not seen in mdx). Alternatively there may be factors present in the mouse that compensate for the lack of dystrophin. It is pointed out that to understand better the different processes occurring in mdx and DMD we need to learn more about the factors which control the balance between the growth of muscle and the growth of connective tissue in both normal and pathological human and mouse muscle.
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PMID:Ultrastructure of the skeletal muscle in the X chromosome-linked dystrophic (mdx) mouse. Comparison with Duchenne muscular dystrophy. 323 77

A deficiency of the protein dystrophin has recently been shown to be the probable cause of Duchenne's muscular dystrophy. We sought to determine the relation between the clinical phenotype and the status of dystrophin in muscle-biopsy specimens from 103 patients with various neuromuscular disorders. We found very low levels (less than 3 percent of normal levels) or no dystrophin in the severe Duchenne phenotype (35 of 38 patients), low concentrations of dystrophin in the intermediate (outlier) phenotype (4 of 7), and dystrophin of abnormal molecular weight in the mild Becker phenotype (12 of 18). Normal levels of dystrophin of normal molecular weight were found in nearly all the patients (38 of 40) with 20 other neuromuscular disorders we studied. These data show the clinical consequences of both quantitative alterations (in Duchenne's and intermediate dystrophy) in a single protein. The biochemical assay for dystrophin should prove helpful in delineating myopathies that overlap clinically with Duchenne's and Becker's dystrophies, and it shows promise as an accurate diagnostic tool.
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PMID:Characterization of dystrophin in muscle-biopsy specimens from patients with Duchenne's or Becker's muscular dystrophy. 328 7

In Duchenne's muscular dystrophy, functional impairment of smooth muscle in the gastrointestinal tract can cause acute gastric dilatation and intestinal pseudo-obstruction that may be fatal. We describe a patient with this syndrome who at autopsy had smooth-muscle degeneration of the stomach. To provide objective evidence of functional smooth-muscle impairment in Duchenne's dystrophy, we performed gastric-emptying studies in 11 patients and 11 normal controls, using technetium-99m radionuclide scintigraphy in a test meal of oatmeal. The patients with Duchenne's dystrophy had delayed gastric-emptying times (118.18 +/- 32.21 minutes [mean +/- SEM]) as compared with controls (42.5 +/- 3.4 minutes, P less than 0.01). The cause of the pathological and functional abnormalities we describe in smooth muscle is unknown but may be a deficiency of dystrophin, the recently identified gene product of the Duchenne's muscular dystrophy locus.
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PMID:Gastric hypomotility in Duchenne's muscular dystrophy. 338 Jan 14

1. We examined the activity of single mechanosensitive ion channels in recordings from cell-attached patches on myoblasts, differentiated myotubes and acutely isolated skeletal muscle fibres from wild-type and mdx and dy mutant mice. The experiments were concerned with the role of these channels in the pathophysiology of muscular dystrophy. 2. The predominant form of channel activity recorded with physiological saline in the patch electrode arose from an approximately 25 pS mechanosensitive ion channel. Channel activity was similar in undifferentiated myoblasts isolated from all three strains of mice. By contrast, channel activity in mdx myotubes was approximately 3-4 times greater than in either wild-type or dy myotubes and arose from a novel mode of mechanosensitive gating. 3. Single mechanosensitive channels in acutely isolated flexor digitorum brevis fibres had properties indistinguishable from those of muscle cells grown in tissue culture. The channel open probability in mdx fibres was approximately 2 times greater than the activity recorded from wild-type fibres. The overall level of activity in fibres, however, was roughly an order of magnitude smaller than in myoblasts or myotubes. 4. Histological examination of the flexor digitorum brevis fibres from mdx mice showed no evidence of myonecrosis or regenerating fibres, suggesting that the elevated channel activity in dystrophin-deficient muscle precedes the onset of fibre degeneration. 5. An early step in the dystrophic process of the mdx mouse, which leads to pathophysiological Ca2+ entry, may be an alteration in the mechanisms that regulate mechanosensitive ion channel activity.
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PMID:Mechanosensitive ion channels in skeletal muscle from normal and dystrophic mice. 753 13

Sixty-four muscle biopsies obtained from patients with Duchenne muscular dystrophy, limb-girdle dystrophy, congenital muscular dystrophy, or who referred for diagnosis were examined with histochemical methods for dystrophin staining with antidystrophin antibodies. Six atypical cases in whom the dystrophin expression was inconsistent with both clinical and morphopathological pattern were selected: one case of Duchenne muscular dystrophy in whom dystrophin was partially represented, one case referred for investigation in whom dystrophin was absent, despite the lack of clinico-morphological signs supporting the diagnosis of Duchenne disease, two cases of congenital muscular dystrophy in whom dystrophin was absent and one patient with the same diagnosis in whom dystrophin was present, but quantitatively reduced. A patient with limb-girdle muscle dystrophy, in whom immunohistochemical investigation was necessary for the diagnosis is also reported. In conclusion, the immunohistochemical investigation using antidystrophin labelled antibodies of muscle biopsies obtained from patients with various types of muscular dystrophy is mandatory.
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PMID:Immunohistochemistry in the diagnosis of dystrophinopathies. 754 71


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