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

Total body potassium (40K method) and total body water and exchangeable sodium (both by isotope dilution) were determined in 26 boys, aged 5-17 years, with muscular dystrophy. Total body potassium values were compared with measurements in a large series of normal boys on the basis of height. Total body potassium was reduced even in the youngest patients and was only slightly higher in the older boys, despite their considerably greater height. Exchangeable sodium increased with increasing height in a way similar to that of normal boys. Total body water was also reduced but increased with growth, although to a lesser extent than expected for normal boys. The total body water measurements indicated that many of the affected boys were very obese, despite an apparently normal body weight. An intravenous bolus of 22Na distributed at a similar rate in boys with muscular dystrophy to that in normal males. In relation to the predicted values, total body potassium and 24 h urinary creatinine excretion of the affected boys both declined at a rate of 4% per year.
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PMID:Total body potassium and water, and exchangeable sodium, in muscular dystrophy. 397 66

Comparison of the skeletal muscles from vitamin E-deficient and control rabbits showed that the muscles from the deficient animals had lower contents of protein and glycogen but more water and lipid. Increases of individual lipids per unit weight of muscle from deficient animals compared with those from control animals were 2.2-fold for gangliosides, 2.18-fold for cholesterol, 1.74-fold for sulfatides, and 1.45-fold for neutral glycosylceramides. Total phospholipids did not change; this was the result of an increase in sphingomyelin (1.47-fold) and a decrease of phosphatidylcholine to 83% of the control, while the other fractions remained unchanged. When the measurements were referred to total muscle, the contents of cholesterol, gangliosides, sulfatides, neutral glycosylceramides, and sphingomyelin in muscle from vitamin E-deficient rabbits were also above those of the control rabbits, and only the phosphatidylcholine content was decreased. It was not possible to determine whether the alteration of lipid content preceded or followed the onset of signs of muscular dystrophy.
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PMID:Changes of gangliosides and other lipids in skeletal muscle from rabbits with experimental dystrophy. 435 42

Chicks affected with hereditary muscular dystrophy were deprived of water for 1 to 4 days at ages to 37 days ex ovo. Water deprivation partially alleviated impaired righting ability and reduced the typically elevated plasma creatine kinase activity by as much as 90%. Muscles from water-deprived chicks showed several qualitative histologic improvements, including decreased sarcoplasmic staining for acetylcholinesterase activity, reduced fiber diameters, and a decreased incidence of abnormally large rounded fibers, but retained the high degree of fiber diameter variability characteristic of dystrophic muscles. Feed deprivation reduced body weight to a similar extent as water deprivation but had lesser effects on creatine kinase activity and did not improve righting ability or muscle histology. Although the mechanism of the improvements is unknown, the magnitude and scope of the effects suggest that water deprivation beneficially alters a major abnormality in dystrophic chickens.
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PMID:Water deprivation: beneficial effect on muscular dystrophy in chickens. 682 62

Chickens with inherited muscular dystrophy (Line 413) were treated in two separate trials with daily intraperitoneal injections of 10% DMSO-water solutions containing the proteinase inhibitors, Ep475 and E64. Drug therapy in each case significantly prolonged the functional ability of the treated chickens. Diluent control chickens around day 35 ex ovo characteristically reached a maximum ability to right from the supine position in a standardized functional test for muscle weakness. Subsequently, the control chickens were found to decline progressively in their ability to right. Treatment with the proteinase inhibitors had no effect on the typically elevated levels of plasma creatine kinase activity. In a histological analysis of the affected pectoralis major muscle, drug treatment had no effect on the relative distribution of degenerating, and vacuolated fibers, inflammatory cells, and abnormal fiber diameters. An exception was seen in decreased necrotic fibers of chickens treated with high doses of Ep475. Moreover, both inhibitors had positive effects on two biochemical abnormalities common to the dystrophic pectoralis muscle: increase in noncollagen protein, and reduction in total calcium.
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PMID:Limited benefit to genetically dystrophic chickens from a synthetic proteinase inhibitor: Ep475. 687 13

Nuclear magnetic resonance (NMR) techniques were applied to study the muscular dystrophy in chicks. The water proton spin-lattice relaxation times (T1) of fast, slow, and mixed muscles and plasma were measured. The T1 values of dystrophic pectoralis major and posterior latissimus dorsi (PLD) were significantly higher than those of the normal pectoralis and PLD muscles. The present results establish a direct relationship between the differences in T1 values and the severity of muscle degeneration. Consistent with this conclusion, it was also found that the T1 values of muscles unaffected in muscular dystrophy, namely, the gastrocnemius, and anterior latissimus dorsi (ALD), were not different between the normal and dystrophic chicks. Although the affected muscles of dystrophic chicks contained higher percent water and fat than those of normal chicks, the results show that the higher T1 values in dystrophic muscles were not solely due to variations in their water content. The increase in the T1 values is principally a result of altered interaction between cellular water and macromolecules in the diseased muscles. These data also point out the potential use of NMR imaging in evaluating muscle degeneration.
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PMID:Evaluation of muscle degeneration in inherited muscular dystrophy by nuclear magnetic resonance techniques. 692 97

Long-term administration of the beta 2-adrenergic agonist clenbuterol in mdx mice was used to test the hypothesis that increasing contractile protein content in skeletal muscle will decrease the progression of muscular dystrophy. C57BL/10SNJ (control) and dystrophic (mdx) mice were given clenbuterol (1.0-1.5 mg/kg body weight/day) in the drinking water. Ventilatory function and morphological and functional characteristics of soleus (SOL) and diaphragm (DIA) muscles were evaluated. Clenbuterol administration was associated with increased SOL muscle weight, and SOL muscle weight to body weight ratio in control and mdx mice at both ages. There was a 22% increase in myosin concentration of mdx DIA at 1 year of age, correlating well with increased normalized active tension in mdx DIA at this age. Also, absolute tetanic tension increased in control and mdx SOL with clenbuterol at both ages. Ventilatory function was significantly impaired in mdx mice at both ages and clenbuterol administration did not alleviate this. Clenbuterol treatment was associated with a 30-40% increase in fatigability in DIA and SOL muscles of control and mdx mice at both ages. Furthermore, 1-year-old mdx mice receiving clenbuterol exhibited deformities in hindlimbs and spine. These results suggest that long-term clenbuterol treatment has a positive effect on muscle growth and force generation, but has adverse side effects such as increased muscle fatigability and development of deformities.
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PMID:Beneficial versus adverse effects of long-term use of clenbuterol in mdx mice. 747 69

Membrane-mediated excessive intracellular calcium accumulation (EICA) is a fundamental pathogenetic event associated with chronic muscle degeneration in patients with Duchenne muscular dystrophy (DMD), and in animals with hereditary muscular dystrophy (HMD). Because of potential Ca(2+)-channel blocking properties, we investigated the relative efficacies of chronic diltiazem (DTZM) (50 mg/kg/d), nifedipine (NFDN) (6 mg/kg/d), and verapamil (VPML) (25 mg/kg/d) therapies in reducing EICA and improving dystrophic pathobiology beginning in 30-day-old male BIO-14.6 strain dystrophic hamsters (DH). Each agent, and sterile distilled water as vehicle control, was given in a single daily oral dose for 180 days to four groups each of DH and BIO-F1B strain normal hamsters (NH). Plasma [Ca] and [Mg]; plasma aldolase (ALD), creatine kinase (CK), and lactate dehydrogenase (LDH) activities; relative cardiac hypertrophy and relative soleus hypertrophy; tissue [Ca] and [Mg] of the heart and rectus femoris muscle, histology of rectus femoris, and overall mortality rate were quantitated. Muscle Mg was not modified in DH, or by any of these agents. NFDN produced significant edema in the soleus and myocardium. During the 6-month therapeutic trial, 45% DH and 18% NH died on VPML, 27% DH and 9% NH on NFDN, and 20% DH controls on distilled water, but none on DTZM; suggesting that DTZM treated DH lived longer than DH controls. Relative efficacy in regulating EICA in both the cardiac and skeletal muscles; plasma ALD, CK, and LDH; and improving associated dystrophic pathobiology was found to be DTZM >>> NFDN > VPML. DTZM appears to be the most effective and safest agent in mitigating EICA in cardiac and skeletal muscles, efflux of intracellular enzymes, histopathology of dystrophic muscle with sporadic necrosis, and chronic muscle degeneration in DH with HMD. DTZM therapy also halted the high morbidity and mortality associated with the dystrophic pathobiology inherent in DH.
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PMID:Regulation of membrane-mediated chronic muscle degeneration in dystrophic hamsters by calcium-channel blockers: diltiazem, nifedipine and verapamil. 846 95

Body hydration and extra- to intra-cellular water ratio (ECW: ICW) have been studied in 12 duchenne muscular dystrophy (DMD) patients and 15 healthy controls. Subjects underwent total body water (TBW) and extracellular water (ECW) assessment by deuterium and bromide dilution, respectively. Multifrequency bioelectric impedance analysis (MFBIA) was performed on all subjects with the aim to establish its accuracy in predicting TBW and ECW in DMD. Body hydration was lower (51.8 +/- 2.8 vs 58.5 +/- 5.9%, P < 0.01) and the ECW: ICW ratio higher (1.15 +/- 0.25 vs 0.70 +/- 0.23, P < 0.001) in DMD than in control subjects. Hence, control-generated formulae for predicting TBW and ECW from MFBIA gave inaccurate results in DMD subjects. Population-specific formulae were developed to obtain an accurate prediction of body water compartments in DMD patients.
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PMID:Multifrequency bioelectric impedance measurements for predicting body water compartments in duchenne muscular dystrophy. 884 19

Lack of dystrophin, a protein localized to the inner surface of the sarcolemma of the muscle fiber, is the cause of Duchenne type muscular dystrophy. Plasma membrane damage of the muscular fiber occurs, followed by Ca++ influx into the fibers. There is severe mitochondrial damage in dystrophic but still viable fibers. Five children aged 5-7 years were studied with MRI, TI-201, and Tc-99m sestamibi scintigraphy of the thighs. These three methods showed that the sartorius is the least damaged muscle in Duchenne type muscular dystrophy. MRI showed mild damage of adductors and quadriceps; TI-201 scintigraphy showed a marked reduction of radioactivity in the same muscles; Tc-99m sestamibi uptake occurred only in the sartorius muscle; the quadriceps was not imaged and adductors showed a faint image. A decrease of water in muscular fibers as well as fatty fibrous substitution, occurs after death of the fibers, whereas plasma membrane and mitochondrial damage reduced the uptake of tracers when the fiber is still viable. The interesting mismatch between sestamibi and TI-201 can be explained by considering that the cellular mechanism of uptake and retention of Tc-99m sestamibi involves both plasma membrane and mitochondria, whereas the uptake of TI-201 is only affected by plasma membrane damage.
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PMID:Muscular uptake of Tc-99m MIBI and TI-201 in Duchenne muscular dystrophy. 889 29

The effects of exercise and the combination of exercise and clenbuterol on progression of muscular dystrophy were studied in mdx mice. At 3 wk of age, mdx mice were randomly assigned to sedentary (MS), exercise (ME), or combined exercise and clenbuterol (MEC) groups. Clenbuterol was given in the drinking water (1.0-1.5 mg . kg body weight-1 . day-1), and exercise consisted of spontaneous running activity on exercise wheels. At 3 mo or 1 yr of age, ventilatory function, contractile properties, and morphological characteristics of the soleus (Sol) and diaphragm (Dia) muscles were measured. The mdx mice receiving clenbuterol ran less than the mice without clenbuterol. The combination of clenbuterol and exercise was associated with an increase in Sol muscle weight and a muscle weight-to-body weight ratio of 30-35% compared with the sedentary group and approximately 20% compared to exercise alone. Myosin and total protein concentrations of the Sol and Dia increased in the MEC group at 1 yr of age only. Normalized active tension was increased in the Dia at 1 yr of age in both the ME and MEC groups by approximately 30%. Absolute tetanic tension of the Sol was increased at both 3 mo and 1 yr of age in the MEC compared with the MS group. At 1 yr of age, there was an additional 23% increase compared with the ME group. Fatigability increased in the MEC group by approximately 25% in the Sol and Dia muscles at both ages compared with the MS and ME groups. Results indicate that exercise and exercise plus clenbuterol decrease the progression of muscular dystrophy. However, different mechanisms may be involved because the combination of clenbuterol and exercise resulted in increased fatigability and the development of deformities, whereas exercise alone did not. Therefore, clenbuterol may not be suitable for use in patients with muscular dystrophy.
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PMID:Exercise and clenbuterol as strategies to decrease the progression of muscular dystrophy in mdx mice. 896 30


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