Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1762617 (weakness)
 37,932 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Respiratory disorders during sleep were studied in 42 patients with Duchenne muscular dystrophy (DMD) (mean age 18.4 years). Chest and abdominal movement, nasal airflow, snoring sounds, eye movement, and oxygen saturation were monitored during sleep. Three patterns of disorders were found: obstructive apnea, central apnea, and paradoxical respiration without upper airway obstruction (non-obstructive paradoxical respiration). Of these three patterns, obstructive apnea was the most common. Hypertrophy of the tongue and collapsibility of the upper airway seemed to be responsible for the obstructive apnea in these patients. The relationships between PaCO2 while breathing room air and the various indices of respiratory disorders were studied. The index of central apnea differed significantly between patients in whom PaCO2 was less than 50 Torr (early disease, n = 22) and those in whom PaCO2 was greater than or equal to 50 Torr (advanced disease, n = 20), but the indices of obstructive apnea and non-obstructive paradoxical respiration did not differ between those two groups. In conclusion, sleep disorders were common in patients with DMD, and the most common was obstructive apnea. In the patients with advanced DMD, blood gas analysis showed hypercapnia, and the index of central sleep apnea was high, probably because of respiratory muscle weakness or abnormalities in the respiratory center.
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PMID:[Respiratory disorders during sleep in Duchenne muscular dystrophy]. 747 61

Duchenne muscular dystrophy (DMD) is characterized by clinical weakness and progressive necrosis of striated muscle as a consequence of dystrophin deficiency. While all skeletal muscle groups are thought to be affected, enigmatically, the extraocular muscles (EOM) appear clinically unaffected. Here we show that dystrophin deficiency does not result in myonecrosis or pathologically elevated levels of intracellular calcium ([Ca2+]i) in EOM. At variance with a previous report, we find no evidence for dystrophin-related protein/utrophin up-regulation in EOM. In vitro experiments demonstrate that extraocular muscles are inherently more resistant to necrosis caused by pharmacologically elevated [Ca2+]i levels when compared with pectoral musculature. We believe that EOM are spared in DMD because of their intrinsic ability to maintain calcium homeostasis better than other striated muscle groups. Our results indicate that modulating levels of [Ca2+]i in muscle may be of potential therapeutic use in DMD.
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PMID:Absence of extraocular muscle pathology in Duchenne's muscular dystrophy: role for calcium homeostasis in extraocular muscle sparing. 762 6

Duchenne muscular dystrophy is a fatal disorder characterized by progressive muscular weakness, wasting, and severe muscle contractures in later disease stages. Muscle biopsy reveals conspicuous myofiber degeneration and fibrosis substituting muscle tissue. We quantitatively determined mRNA of the potent fibrogenic cytokine transforming growth factor-beta 1 by quantitative PCR in 15 Duchenne muscular dystrophy, 13 Becker muscular dystrophy, 11 spinal muscular atrophy patients, and 16 controls. Higher transforming growth factor-beta 1 expression was greater in Duchenne muscular dystrophy patients than controls (P = 0.012) and Becker patients (P = 0.03). Fibrosis was significantly more prominent in Duchenne muscular dystrophy than Becker muscular dystrophy, spinal muscular atrophy, and controls. The proportion of connective tissue in muscle biopsies increased progressively with age in Duchenne muscular dystrophy patients, while transforming growth factor-beta 1 levels peaked at 2 and 6 yr of age. Transforming growth factor-beta 1 protein was also detected by immunocytochemistry and immunoblotting. Our findings suggest that transforming growth factor-beta 1 stimulates fibrosis in Duchenne muscular dystrophy. Expression of transforming growth factor-beta 1 in the early stages of Duchenne muscular dystrophy may be critical in initiating muscle fibrosis and antifibrosis treatment could slow progression of the disease, increasing the utility of gene therapy.
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PMID:Expression of transforming growth factor-beta 1 in dystrophic patient muscles correlates with fibrosis. Pathogenetic role of a fibrogenic cytokine. 763 57

Duchenne muscular dystrophy (DMD) is one of a range of muscular dystrophies caused by abnormalities of the short arm of the X chromosome (Xp21), which often cause mental retardation in addition to progressive muscular weakness. Normal dystrophin expression is lacking in both skeletal muscle and brain of affected subjects. Phosphorus-31 magnetic resonance spectroscopy has shown several abnormalities in skeletal muscle in DMD. We looked for similar abnormalities in brain in patients with DMD and related the findings to neuropsychological test results. We studied by magnetic resonance spectroscopy 19 boys (aged 76-167 months) diagnosed as having DMD and 19 control boys of similar age (87-135 months). Intelligence quotient (IQ) was assessed with the Wechsler Intelligence Scale for children. The DMD patients had significantly higher values than the controls in the brain ratios of inorganic phosphate to adenosine triphosphate (mean 0.53 [SD 0.21] vs 0.36 [0.09], p = 0.003), to phosphomonoesters (0.40 [0.07] vs 0.29 [0.07], p = 0.0001), and to phosphocreatine (0.44 [0.10] vs 0.37 [0.08], p = 0.02). There were significant differences between the DMD patients and the controls in full-scale IQ (76 [16] vs 101 [16], p = 0.0001), performance IQ (78 [17] vs 94 [14], p = 0.003), and verbal IQ (78 [17] vs 106 [17], p = 0.0001). These altered metabolite ratios parallel the findings in dystrophic muscle and suggest bioenergetic similarities in tissues that lack dystrophin.
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PMID:Brain abnormalities in Duchenne muscular dystrophy: phosphorus-31 magnetic resonance spectroscopy and neuropsychological study. 774 55

We report on a family with a severe form of X-linked dilated cardiomyopathy (DCM). Two brothers, the elder requiring heart transplantation, and a maternal cousin presented elevated creatine kinase levels, increased right ventricular diameters and electrocardiographic abnormalities. All complained of exertional cramping myalgia, but none had muscle weakness or a pathological electromyogram. Muscle biopsies of these individuals revealed a mild myopathic picture with atrophic type I and hypertrophic type II fibers. Immunofluorescence using N- and C-terminal antibodies (dys-2, dys-3) against the dystrophin protein showed preserved, but reduced intensity of staining of the sarcolemmal membranes. Using the same two antibodies, Western blot analyses revealed a dystrophin molecule of the expected molecular weight, which was quantitatively reduced by 80%. However, the dys-1 antibody, directed against the mid rod region of the dystrophin protein, did not react with dystrophin both on Western blot and immunofluorescence. Linkage analysis with polymorphic markers of the dystrophin gene revealed an identical haplotype at the 5' region in all affected individuals (two point lod score of 1.93, phi = 0). A deletion of exons 48, 45-53, 2-7 and 1 including the promoter region of the dystrophin gene, as described in rare cases with similar clinical signs could be excluded by multiplex PCR and Southern blot analyses of this DCM family. In addition, a major splice-mutation of dystrophin mRNA was excluded by RT-PCR of skeletal and heart muscle tissue. Therefore, we conclude that a novel mutation in the 5' region of the dystrophin gene phenotypically leads to this severe form of DCM. Extensive analyses of the dystrophin gene, in particular of the sequences coding for the antigenic determinants of the dys-1 antibody in the mid rod region, may identify the molecular cause of this monogenetic form of DCM.
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PMID:X-linked dilated cardiomyopathy. Novel mutation of the dystrophin gene. 775 93

Malignant limb-girdle muscular dystrophy was first described by Miyoshi and co-workers in 1966, and has clinical features similar to Duchenne muscular dystrophy but is inherited through an autosomal recessive trait. This paper describes a patient with malignant limb-girdle muscular dystrophy with complete deficiency of adhalin (50 kDa dystrophin-associated glycoprotein (DAG)) in skeletal muscle. The patient was an 11-year-old Japanese girl whose parents were cousin. She learned to walk at one year and 3 months of age. Her gait became unsteady at 3 years of age, and motor dysfunction in the lower extremities progressed thereafter. At 8 years of age, she had difficulty in standing up from a sitting position, but could walk without assistance. At 11 years, she could walk with support, but could not stand up without assistance. Her intelligence was normal. Muscle atrophy was not apparent due to obesity, but her calves appeared hypertrophic. She had generalized muscle weakness, predominantly in the pelvic girdle muscle. Muscle tone was slightly hypotonic, and deep tendon reflexes of the legs were absent or hypoactive. Her sensory system appeared normal. Serum creatine kinase level was elevated to 30 times above the upper limit of the normal range in the patient and normal in her parents. EMG showed a mild myopathic pattern. CT scan of muscle revealed marked low density in the upper legs and mild in the lower legs. Muscle histology showed muscle fiber necrosis with a small number of regenerating fibers. Opaque fibers were occasionally observed, but not as many as in Duchenne type. Fiber splitting was seen frequently.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Complete deficiency of adhalin (50 kDa DAG) in skeletal muscle of malignant limb-girdle muscular dystrophy]. 778 Dec 37

Cardiomyopathy is often found in patients with Duchenne and Becker muscular dystrophy, which are X linked muscle diseases caused by mutations in the dystrophin gene. Dystrophin defects present in many different ways and cases of mild Becker muscular dystrophy have been described in which cardiomyopathy was severe. Female carriers of Duchenne muscular dystrophy can develop symptomatic skeletal myopathy alone or combined with dilated cardiomyopathy. They can also develop dilated cardiomyopathy alone. X linked dilated cardiomyopathy has been found in association with dystrophin defects. The relation between the molecular defects and the cardiac phenotypes has not yet been established. New mutations in the dystrophin gene are common and such mutations cause one third of the cases with Duchenne and Becker muscular dystrophy. This means that sporadic cases of cardiomyopathy caused by dystrophin defects are likely. This paper reports such a case in a boy of 14 who died of dilated cardiomyopathy. Before the cardiac investigation, which was performed one month before he died, he had not complained of muscular weakness. He had minor signs of limb girdle myopathy and slightly increased concentrations of serum creatine kinase. He was found to have an unusual deletion in the dystrophin gene.
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PMID:Dilated cardiomyopathy and the dystrophin gene: an illustrated review. 783 92

The expression of dystrophin, the dystrophin-associated proteins and utrophin has been studied immunocytochemically in three young, manifesting carriers of Duchenne muscular dystrophy, aged 3, 5 and 12 yrs, one adult manifesting carrier, aged 60 yrs, and one presumptive carrier with a raised serum creatine kinase, aged 24 yrs, the mother of the 5-yr-old manifesting carrier. The manifesting carriers had variable degrees of weakness; the presumptive carrier had no weakness. Morphological abnormalities were also variable and were most marked in the young manifesting carriers. The three young manifesting carriers and the presumptive carrier had a mosaic pattern of dystrophin-positive and dystrophin-negative fibres. All the dystrophin-associated proteins were reduced in the dystrophin-deficient fibres, giving a similar mosaic pattern to dystrophin. Expression of dystrophin and the dystrophin-associated proteins was normal in the adult manifesting carrier. Utrophin was detected on the sarcolemma of fibres both with and without dystrophin and the dystrophin-associated proteins. Thus, dystrophin and utrophin are co-expressed in several fibres in carriers. The results emphasize the close association between dystrophin and the glycoprotein complex and their role in the pathogenesis of muscle damage. In addition, the presence of utrophin in fibres with greatly reduced glycoproteins suggests that very little of the glycoprotein complex may be required to anchor the amount of utrophin expressed at the sarcolemma in these particular cases.
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PMID:Expression of dystrophin-associated glycoproteins and utrophin in carriers of Duchenne muscular dystrophy. 788 Dec 85

We report a series of 46 patients (32 women and 14 men) with limb-girdle syndrome. After reappraisal, another diagnosis was made in 10 of them. Becker's muscular dystrophy was the most frequent cause among men (near 50 p. 100). A Duchenne muscular dystrophy manifesting carrier was discovered among 13 reevaluated women. Among the 36 cases (29 women and 7 men) without any defined etiology, 29 were without any other known familial history. Fifteen of these women had similar clinical findings: incipient weakness in the pelvic girdle and onset of symptoms most often in the forties. In these cases serum creatine kinase activity was normal or slightly elevated, and muscle biopsy showed non-specific patterns. "Late onset muscular dystrophy in females" should be reevaluated.
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PMID:[Limb-girdle syndrome. A study of 46 cases]. 799 39

A new double mutant mouse strain, gad-mdx, was established. The transmission of mdx and gad genes was monitored by determining their chemical markers, creative kinase activity and phosphoglucomutase-1 isoenzyme, respectively, in blood samples. This new strain was characterized by high creatine kinase activity in the plasma, lack of dystrophin in the muscle, and the presence of axonal swellings in the neural tissue. Although the body weight and the limb muscle size of the mutant mice were significantly lower than those of either gad or mdx mice, the clinical signs were not evident until the animals were 80 days old. After that time, the disease followed the course seen in the gad strain, and muscle weakness was exhibited in the advanced stages. Histologic examination revealed that the prevalence of muscle fiber necrosis, a deleterious consequence of the mdx gene, was significantly lower in the double mutant strain than in the mdx strain. These results supported the idea that small-caliber muscle fibers, which are induced by gad gene expression, are resistant to dystrophic necrosis. We believe that this double mutant strain will be valuable for the analysis of neural influence on diseased muscle fibers, and that it will also provide an opportunity for the testing of new therapeutic strategies for human Duchenne muscular dystrophy.
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PMID:Breeding of the gad-mdx mouse: influence of genetically induced denervation on dystrophic muscle fibers. 800 58


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