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

Light microscopic, and scanning and transmission electron microscopic studies of the nodes of Ranvier of the distal peripheral nerves of mice with muscular dystrophy (dy/dy) are reported. Extensive widening of the nodes, retraction of Schwann cell cytoplasm and myelin, paranodal thinning of the myelin sheaths, and loss of nodal gap substance were observed. There was no loss of myelinated fibers. The changes at the nodes of Ranvier probably explain the slowed maximum conduction velocity observed in dystrophic peripheral nerves.
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PMID:The nodes of Ranvier in the nerves of mice with muscular dystrophy. 89 25

In 19 patients with Duchenne's muscular dystrophy, left ventricular wall thickness in end-systole and end-diastole was determined serially every 12 months by echocardiography and compared with ventricular wall growth in normal subjects. In the normal subjects, left ventricular wall thickness increased linearly with increasing body surface area. A control group of wheelchair-bound patients with a variety of neurologic disorders, although not followed serially, had a distribution of end-diastolic wall thickness values similar to that of the normal subjects. In patients with muscular dystrophy, wall thickness increased linearly with respect to body surface area for some time and then began to thin. The time at which thinning began was not directly related to age, although it was more common in older than in younger patients. Those patients who died demonstrated marked deviation from normal wall growth. Free wall thinning is probably a result of fibrosis and loss of myofibrils.
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PMID:Serial left ventricular wall measurements in Duchenne's muscular dystrophy. 685 8

Boys with Duchenne's muscular dystrophy (DMD) usually have a cardiomyopathy characterized by fibrosis of the epicardial half of the left ventricle. This cardiomyopathy is difficult to detect by noninvasive techniques. We report a technique that evaluates incremental left ventricular posterior wall thickening and thinning. High-quality left ventricular posterior wall echoes in 24 boys with DMD and 32 controls were recorded at chordal level two times 1 year apart. Endocardial and epicardial echoes and a timing ECG were digitized and analyzed by minicomputer. Left ventricular wall amplitudes were determined at standardized temporal increments during contraction and relaxation. To compare with this left ventricular assessment technique, systolic ejection times, shortening fraction and mean velocity of circumferenial fiber shortening (Vcf) were also computed in the standard way. Mean year-to-year changes were minor. Mean Vcf, the ratio of preejection period to left ventricular ejection time and shortening fraction during the first year were statistically similar to those of the controls. Shortening fraction decreased slightly during the second year and became significantly different from the control, but remained within the normal range. Left ventricular wall thickness and cavity size were significantly less in boys with DMD than in controls. Therefore, we had to normalize incremental wall thickness to determine if any significant difference occurred. To do this, we evaluated the percentage of maximal wall thickness which occurred at a given percent of systole and diastole. Using this technique, it was shown that thickening during systole was a nearly linear process with respect to time in both groups. However, relaxation was significantly different between the groups. Relaxation was found to be an alinear process, and most thinning occurred in the first 40% of diastole. The major findings of this investigation was that the left ventricular wall of boys with DMD thinned at a slower rate than that of normal subjects. This new technique appears to be sensitive and demonstrates subtle changes in the left ventricular posterior wall.
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PMID:Echocardiographic determination of contraction and relaxation measurements of the left ventricular wall in normal subjects and patients with muscular dystrophy. 741 57

Myocardial velocity gradient and wall-thickening velocity were measured in the interventricular septum and left ventricular posterior wall (LVPW) by color-coded M-mode Doppler tissue echocardiography in patients with Duchenne's progressive muscular dystrophy (DMD) with a normal shortening fraction (n = 14) and age-matched control subjects (n = 40). In the LVPW, peak myocardial velocity gradients during systole and early diastole were significantly lower for patients with DMD than in control subjects (P <.0005, and P <.0001, respectively). Peak myocardial wall-thickening velocities of the LVPW during systole and early diastole were also lower for patients with DMD (P <.0005 and P <.0001, respectively). Mitral peak atrial to early filling velocity ratio was not significantly different between the 2 groups. The cut-off values of peak myocardial velocity gradients and wall-thickening velocities of the LVPW during early diastole for differentiation between patients with DMD and control subjects were -5.8/s and -6.0 cm/s, respectively (sensitivity/specificity: 93%/93% and 93%/85%, respectively). In conclusion, wall thinning during early diastole is frequently abnormal in patients with DMD, even when conventional echocardiographic findings are normal.
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PMID:Peak negative myocardial velocity gradient and wall-thickening velocity during early diastole are noninvasive parameters of left ventricular diastolic function in patients with Duchenne's progressive muscular dystrophy. 1504 64

Golden Retriever muscular dystrophy is an inherited, degenerative myopathy due to the absence of dystrophin and is used as a model of Duchenne muscular dystrophy of young boys. This report describes the radiographic abnormalities of Golden Retriever muscular dystrophy in 26 dogs. The thoracic abnormalities included diaphragmatic asymmetry (18/26), diaphragmatic undulation (18/26), and gastro-esophageal hiatal hernia (6/26). Pelvic abnormalities included narrowing of the body of the ilia (14/19), ventral deviation and curvature of the tuber ischii (14/19), elongation of the obturator foramen with a decrease in opacity of the surrounding bone (12/19), and lateral flaring of the wings of the ilia (12/19). Abdominal abnormalities consisted of hepatomegaly (14/22) and poor serosal detail (12/22). The unique thoracic abnormalities were a consistent finding in affected Golden Retriever muscular dystrophy dogs. The diagnosis of muscular dystrophy should be included in the differential list if the combination of diaphragm undulation and asymmetry, and gastro-esophageal hiatal hernia are identified. These diaphragmatic abnormalities are related to hypertrophy and hyperplasia of the diaphragm. Additionally, the skeletal changes of pelvic tilt, elongation of the pelvis, widening of the obturator foramina and thinning of the ischiatic tables appear to be specific to Golden Retriever muscular dystrophy in dogs. These pelvic abnormalities are most likely secondary to bone remodeling associated with the progressive skeletal myopathy and subsequent contracture/fibrosis.
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PMID:Radiographic features of Golden Retriever muscular dystrophy. 1715 67

Limb girdle muscular dystrophy type 2I (LGMD2I) is due to mutations in the fukutin-related protein gene (FKRP), encoding a putative glycosyltransferase involved in alpha-dystroglycan processing. To further characterize the molecular pathogenesis of LGMD2I, we conducted a histological, immunohistochemical, ultrastructural and molecular analysis of ten muscle biopsies from patients with molecularly diagnosed LGMD2I. Hypoglycosylation of alpha-dystroglycan was observed in all FKRP-mutated patients. Muscle histopathology was consistent with either severe muscular dystrophy or myopathy with a mild inflammatory response consisting of up-regulation of class I major histocompatibility complex in skeletal muscle fibers and small foci of mononuclear cells. At the ultrastructural level, muscle fibers showed focal thinning of basal lamina and swollen endoplasmic reticulum cisternae with membrane re-arrangement. The pathways of the unfolded protein response (UPR; glucose-regulated protein 78 and CHOP) were significantly activated in LGMD2I muscle tissue. Our data suggest that the UPR response is activated in LGMD2I muscle biopsies, and the observed histopathological and ultrastructural alterations may be related to sarcoplasmic structures involved in FKRP and alpha-dystroglycan metabolism and malfunctioning.
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PMID:Biochemical and ultrastructural evidence of endoplasmic reticulum stress in LGMD2I. 1795 92

Mutations in the gene encoding the basal lamina (BL) component laminin alpha2 (LAMA2) cause merosin-deficient congenital muscular dystrophy 1A (MDC1A), a complex disorder that includes hypomyelination and myodegeneration. In dystrophia muscularis (dy) mice bearing Lama2 mutations, myofibers and Schwann cells fail to assemble stable BLs, which are thought to be crucial for myofiber survival and Schwann cell differentiation. Here, we describe defects in a new allele of Lama2 in mice, nmf417, in which a point mutation substitutes Arg for Cys79 at a universally conserved CxxC motif in the laminin N-terminal (LN) domain; this domain mediates laminin-laminin interactions. nmf417 homozygosity caused progressive myodegeneration and severe peripheral amyelination in nerve roots, similar to previous Lama2 mutations, but without the pervasive BL thinning previously associated with the disorder. In direct contrast to the previously characterized dy and dy2J alleles, nmf417 homozygous myofibers frequently had thickened BLs. Severe amyelination in nmf417-mutant nerve roots suggested complete laminin 2 inactivation for Schwann cells, although myelinated fibers had normal BLs. The results reveal crucial roles for the LN domain CxxC motif in both nerve and muscle, but challenge expected relationships between LN-domain function, Ln2 activity and BL stability. The nmf417 mutation provides a defined animal model in which to investigate mechanisms and treatments for moderate forms of MDC1A.
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PMID:A single point mutation in the LN domain of LAMA2 causes muscular dystrophy and peripheral amyelination. 1843 Jul 79

We report a young male of autosomal recessive limb girdle muscular dystrophy (LGMD) with positive family history presented with gradual onset proximal muscle weakness in all four limbs since eight years and thinning of shoulders, arms and thighs. Neurological examination revealed atrophy of both shoulders with wasting of both deltoids thinning of thighs and pseudo hypertrophy of both calves, hypotonia in all four limbs. Gower's sign was positive. Winging of scapula was present. Power was 3/5 at both shoulders, 4/5 at both elbows, 5/5 at both wrists, 3/5 at both hip joints, 3/5 at both knees, 5/5 at both ankles. All deep tendon reflexes and superficial reflexes were present with plantars bilateral flexors. Electromyography (EMG) showed myopathic pattern. He had elevated creatinine phosphokinase levels and muscle biopsy findings consistent with muscular dystrophy.
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PMID:Limb Girdle Muscular Dystrophy (LGMD): Case Report. 2573 22