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)

We have demonstrated that maneuvers capable of reducing Ca influx into cells have beneficial effects in dystrophic hamsters and Duchenne muscular dystrophy. Since dantrolene inhibits Ca release from the sarcoplasmic reticulum, its effects on DMD was studied in 7 patients of 6 to 13 years of age (mean 10.8 years). Patients were studied for 4 years with tri-monthly evaluations of manual muscle testing (MMT), functional activity, and serum CK and aldolase. During the first 2-year period, no medicines were given and served as control. In the second 2-year period, dantrolene 8 mg/kg/d was administered. No side effects were observed. In 1 patient, mild weakness occurred that disappeared when the dose was reduced to 6 mg/kg/d. The 95% confidence limit for the difference in slopes of regression lines from tri-monthly MMT was asymmetric in favor of dantrolene in 5 of 7 patients. Serum CK did not differ between the first and second year of the control and treatment periods, respectively. However, it fell significantly from the second year of control to the first year of treatment (P = 0.003). The fall during the first year of treatment was significantly greater (P less than 0.01) than in age-matched natural history controls during the same length of observation. There was a 3-fold reduction in CK when the pooled values of the first and second year control vs. treatment periods were analyzed. No changes were observed in functional activity and serum aldolase. The data suggest that dantrolene reduces serum CK in DMD associated with a lessening trend in MMT deterioration.
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PMID:Effect of dantrolene in Duchenne muscular dystrophy. 185 56

Two long-living brothers of dystrophin-related muscular dystrophy with an in-frame deletion of exon 3 of the dystrophin gene were described. Weakness of the lower extremities and pseudohypertrophy of calf muscles began at the age of 2 years in the elder brother and 4 years in the younger brother, respectively. Clinical symptoms progressed rapidly and both of them lost ambulation and became wheelchair bound at the age of 11-12 years. However, the progression of the disease process slowed in late teens, and now at the age of 36 and 33 years, respectively, they do not have respiratory or cardiac insufficiency, although they are disabled severely. Southern blotting with the entire dystrophin cDNAs, cDNA 1-2a, 2b-3, 4-5a, 5b-7, 8, and 9-14, revealed a single deletion of exon 3 in the 2 brothers. The mother was shown to be a heterozygote for this mutation. The unique clinical features of these brothers were presumed due to the following 2 factors: (1) a single deletion of exon 3 is an in-frame deletion of the dystrophin gene, and (2) exon 3 corresponds to a unique domain of the dystrophin molecule; the amino-terminal region which is highly homologous to the actin-binding-region of alpha-actinin. We consider that these 2 brothers are compatible with the so-called frame-shift hypothesis of Duchenne/Becker muscular dystrophy (DMD/BMD) phenotype, although they are diagnosed DMD by the classification method based on the patients' age of becoming permanently wheelchair bound.
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PMID:[Two long-living brothers of dystrophin-related muscular dystrophy with an in-frame deletion of exon 3 of the dystrophin gene--clinical features and diagnosis]. 189 67

X-linked DMD is a serious condition characterized by progressive muscle wasting and weakness and death ensues in the late teens or early twenties. There is considerable clinical variability even within families and some suggestions of genetic heterogeneity. Though skeletal muscle is primarily involved, other tissues are also affected including cardiac and smooth muscle. Other abnormalities include mental retardation, thymus hyperplasia and possibly certain endocrinological changes. The responsible locus is at Xp21 and the gene product is a very large protein (dystrophin) which is normally localised to muscle cell membranes. It is hypothesised that its absence in DMD may result in instability of the muscle cell membrane with resultant ingress of calcium, an increase in intracellular calcium, and cell death. An understanding of this pathway is important in devising an effective treatment.
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PMID:Clinical and molecular studies in Duchenne muscular dystrophy. 266 10

We studied a Becker muscular dystrophy (BMD) family with a manifesting carrier. Proximal muscle weakness, pseudohypertrophy of the calves, significantly elevated serum creatine kinase and dystrophic alterations in the muscle biopsy were the characteristic phenotypical features of this manifesting carrier. The recombinant DNA study showed a recombinant chromosome with a crossover between pERT 87-8 and pERT J-Bir in the manifesting carrier. However, the proximal part of the short arm of her X chromosome was identical to a non-manifesting carrier (her sister) and to her affected brother. For this reason, we assumed the BMD mutation was proximal to the crossover. The dystrophin cDNA probes showed no deletion of DMD/BMD gene.
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PMID:Manifesting carrier of Becker muscular dystrophy (BMD): clinical and recombinant DNA studies. 278 30

Duchenne and Becker muscular dystrophy (DMD and BMD) genes are located in Xp21 on the short arm of the X chromosome. DMD patients display a much more severe clinical course than BMD patients, and yet about 10% of cases of each have been reported to have deletions for parts of the gene. Using a complementary DNA subclone of the DMD gene we have screened 66 DMD and BMD patients who had not previously shown deletions with the probes then available. Fifteen patients have a deletion of this part of the gene, indicating a higher deletion frequency in this region (22%). Exons were deleted in five severely affected DMD patients and in ten BMD patients. Significantly, most of these deletions begin in the same region of the cDNA, which implies that there is a common mechanism for the generation of many of these mutations. An apparently identical deletion in one family gave classical BMD in two brothers (presenting in their teens) and only very mild muscle weakness in their 86-year-old great-great-uncle. Taking these data together with data using the probes previously published, we are able to detect deletions directly in 40% of our families requiring antenatal diagnosis or carrier detection.
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PMID:Preferential deletion of exons in Duchenne and Becker muscular dystrophies. 282 6

We report a family with manifesting DMD carriers over two generations. Sixty years old female (case 1) suffered from slowly progressive weakness since her thirties. Her youngest daughter aged 30 (case 2) had cramping calf muscle pain since her 5 years old. Progressive muscle weakness developed and lost her ambulation by the age of 20. Grandson of case 1 (son of case 1's eldest daughter who has no clinical symptoms) was diagnosed as DMD with deletion of exon 19-21 in dystrophin gene. Case 1 and case 2 were revealed to be DMD carriers. We speculate that, in this family, X-inactivation process was not random and paternal X was preferentially inactivated by maternal mutant X.
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PMID:[Manifesting carriers of Duchenne muscular dystrophy over two generations]. 810 23

The objective of this study was to compare the tibial structure and the strength of the tibia during muscle weakness and after recovery in mdx mice (which demonstrate X-linked muscular dystrophy and subsequent muscle regeneration) and age-matched control mice. The extent of disuse atrophy produced by muscle weakness and recovery following restoration of normal muscle strength could then be determined. The tibiae adjacent to weakened tibialis anterior muscles of 4-week-old mdx mice had significantly reduced radiographic density (p < 0.05) and cortical thickness (p < 0.001), and increased porosity (p < 0.001) compared to age-matched controls, suggesting development of disuse osteopenia. Significantly less force was required to break mdx tibiae than age-matched control tibiae (p < 0.05). In addition, Sharpey's fiber density was reduced (p < 0.001), suggesting a weakened attachment of the tibialis anterior muscle to bone. At 12 weeks, during the period of muscle regeneration, mdx tibial cortical thickness (p < 0.001) and porosity (p < 0.01) remained significantly lower, but percent calcium and Sharpey's fiber and radiographic densities were significantly greater (p < 0.001) than in age-matched controls, suggesting that bone mineralization and muscle attachment strength had increased to above normal levels in parallel with recovery of strength by the attached muscle. By 18 weeks, mdx tibial cross-sectional area, cortical thickness, and porosity remained significantly less (p < 0.001) than normal. Although Sharpey's fiber density was greater than in age-matched controls (p < 0.001) by 18 weeks, mdx tibial percent calcium (p < 0.005) and Sharpey's fiber density (p < 0.001) were significantly reduced from levels in 12-week-old mdx animals. There was significantly less deformation of the tibia prior to fracture in mdx than control tibiae at 18 weeks of age, suggesting tibial brittleness. Thus, at the site of attachment of mdx muscle to osteopenic bone, the remodelling which accompanies recovery of muscle strength is atypical, and produces an attachment of greater strength than function appears to require. These observations suggest that data are needed regarding bone mass and muscle-bone attachments in humans with disuse osteopenia, DMD, and other neuromuscular diseases.
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PMID:Recovery from disuse osteopenia coincident to restoration of muscle strength in mdx mice. 827 5

Duchenne and Becker muscular dystrophy (DMD and BMD) are X-linked recessive diseases caused by defective expression of dystrophin. The mdx mouse, an animal model for DMD, has a mutation that eliminates expression of the 427K muscle and brain isoforms of dystrophin. Although these animals do not display overt muscle weakness or impaired movement, the diaphragm muscle of the mdx mouse is severely affected and shows progressive myofibre degeneration and fibrosis which closely resembles the human disease. Here we explore the feasibility of gene therapy for DMD by examining the potential of a full-length dystrophin transgene to correct dystrophic symptoms in mdx mice. We find that expression of dystrophin in muscles of transgenic mdx mice eliminates the morphological and immunohistological symptoms of muscular dystrophy. In addition, overexpression of dystrophin prevents the development of the abnormal mechanical properties associated with dystrophic muscle without causing deleterious side effects. Our results provide functional evidence for the feasibility of gene therapy for DMD.
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PMID:Overexpression of dystrophin in transgenic mdx mice eliminates dystrophic symptoms without toxicity. 835 80

Respiratory failure is an important cause of death in many neuromuscular diseases. We studied the relationship between nocturnal hypoxemia and respiratory muscle weakness by nocturnal pulseoxymetry and spirometry in two major hereditary myopathies, myotonic and Duchenne muscular dystrophies (MD and DMD respectively). In DMD significant nocturnal periodic hypoxemia appears only in cases with vital capacity lower than 20% of its expected value, suggesting that % vital capacity is a useful index of early respiratory failure. In contrast there was no correlation between vital capacity and severity of hypoxemia in MD patients. Therefore, we conclude respiratory muscle weakness is a single important factor which determines the severity of respiratory failure in DMD, while another/other factor (s), such as disturbance of respiratory control or myotonia, may play an important role in MD.
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PMID:[Different mechanism may underlie respiratory failure of myotonic and Duchenne muscular dystrophies--a pulseoxymetric and spirometric study]. 895 51

Dystrophin gene was analysed in 32 unrelated DMD families (46 subjects: 32 index cases and 14 sibs) for the presence of deletions by mPCR for 27 exons and cDNA probes for the entire gene. Deletions were identified in 32 patients (25 index cases and seven sibs) from 25 families. The concordance between the clinical phenotype and 'reading frame' hypothesis was observed in 24 (75%) cases. Of these, nine patients were wheelchair bound between 8-12 years of age, nine (age range 5-10 years) showed progressive difficulty in walking and six (age range 1.6-4 years) had onset of muscle weakness. One patient (CH), who was wheelchair bound at 12 years, the effect of mutation on the ORF could not be ascertained due to the presence of a junction fragment. Seven patients had inframe deletions of which four were wheelchair bound by the age of 13 years, and three (age range 5-7 years) although, ambulatory had difficulty in walking. There were eight patients who showed no deletion, of which four became wheelchair bound by the age of 12 years, four, though still ambulatory, were unable to run and tired easily. Correlation between phenotype and genotype of these DMD patients demonstrates that genetic studies of lymphocyte DNA may not always reflect the situation in the tissue involved in dystrophin, i.e. muscle. We describe a common dystrophin gene polymorphism in the Indian population with cDNA 11-14 that alters the Hind III restriction sites. Novel RFLPs were observed in 26 patients and their family members. Whether this is a polymorphism or, related to the diseased phenotype needs confirmation.
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PMID:Molecular characterisation of Duchenne muscular dystrophy and phenotypic correlation. 961 43


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