Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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

31P nuclear magnetic resonance (NMR) was used to investigate the resting energy metabolism of the calf muscle in boys with Duchenne's muscular dystrophy. Reductions in the phosphocreatine/adenosine triphosphate (PCr/ATP) and the PCr/Pi ratios were found, but ATP as a fraction of the total mobile phosphorus signal was not reduced, and intracellular pH was normal in the Duchenne muscle. Attempts at quantitation of the NMR signal suggested that the reduced total phosphorus signal seen in the Duchenne muscle was a result of muscle fiber loss only and that the muscle fiber ATP concentration was probably normal in the diseased tissue. An exercise study in one 7-year-old boy with Duchenne's dystrophy demonstrated that the muscle had a normal ability to break down and resynthesize phosphocreatine. Presented here are the first reported trials of the effects of two putative therapeutic agents on energy metabolism determined by NMR in Duchenne's muscular dystrophy.
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PMID:Muscle energy metabolism in Duchenne dystrophy studied by 31P-NMR: controlled trials show no effect of allopurinol or ribose. 393 26

The forearm flexor muscles of five patients with Becker's dystrophy were examined by the painless and noninvasive technique of high resolution phosphorus nuclear magnetic resonance spectroscopy. In the mildly affected cases, the ratios of the signals of phosphocreatine to ATP and to inorganic phosphate were normal but they were reduced in the patients with advanced disease. Absolute quantitation under the conditions of the study was not feasible, but it was probable that whereas in advanced Becker's dystrophy the intramyocellular concentration of phosphocreatine was reduced, that of ATP was unchanged. The intramyocellular pH was normal in three of the four patients in whom this could be measured and an additional unidentified signal between those of phosphocreatine and inorganic phosphate was recorded in two patients. This study emphasizes some metabolic similarities between Becker's and Duchenne type muscular dystrophy and suggests that nuclear magnetic resonance spectroscopy may be a useful and objective technique with which to investigate the biochemistry of these and other muscle diseases.
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PMID:An in vivo study of muscle phosphate metabolism in Becker's dystrophy by 31P NMR spectroscopy. 402 5

Coenzyme Q(10) (CoQ(10)) exists in human tissue, and is indispensable to mitochondrial enzymes of respiration. CoQ was administered to children with preclinical muscular dystrophy, CoQ enzymology was emphasized, and serum creatine phosphokinase, CPK, (ATP:creatine N-phosphotransferase, EC 2.7.3.2) was repeatedly monitored.A 40-week treatment of an infant, 1-2 years of age, reduced serum CPK (P < 0.001; total CPK assays, 76). A 40-week treatment of a boy, 3-5 years of age, reduced serum CPK (P < 0.01); treatment through 80 weeks reduced CPK (P < 0.001; total CPK assays, 118). This response of preclinical dystrophy to CoQ implies a deficiency of CoQ in skeletal muscle that was actually found previously by assay of the activity of the succinate dehydrogenase:coenzyme Q(10) reductase of the rectus abdominis. The relationships among a CoQ deficiency in muscle, serum CPK, and use of CPK in muscle are uncertain; however, restoration of CoQ enzyme activity in muscle by oral administration of CoQ could lead to increased use of CPK in muscle to form phosphocreatine from creatine and ATP, with a corresponding decrease in serum levels of CPK. The great excess of CPK in serum comes from deteriorating muscle in which CPK is below normal.
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PMID:Effect of coenzyme Q on serum levels of creatine phosphokinase in preclinical muscular dystrophy. 452 74

Total creatine or phosphocreatine, or both, are reduced in the skeletal muscle of patients with inflammatory myopathy, mitochondrial myopathy, and muscular dystrophy/congenital myopathy. We used Western blotting techniques to measure skeletal muscle creatine transporter protein and sarcomeric mitochondrial creatine kinase (mtCK) protein content in patients with inflammatory myopathy (N = 8), mitochondrial myopathy (N = 5), muscular dystrophy (N = 7), and congenital myopathy (N = 3), as compared to a control group without a neuromuscular diagnosis (N = 8). Creatine transporter protein content was lower for all groups compared to control subjects (P < 0.05; P < 0.01 for congenital myopathy). Mitochondrial CK (mtCK) was lower for inflammatory myopathy (P < 0.05), higher for mitochondrial myopathy (P < 0.05), not different for muscular dystrophy, and markedly lower for the congenital myopathy group (P < 0.01), compared to control subjects. Together, these data suggest that the reduction in total creatine or phosphocreatine in patients with certain myopathies is correlated with creatine transporter and not mtCK protein content. This further supports the belief that creatine monohydrate supplementation may benefit patients with low muscle creatine stores, although the reduction in creatine transporter protein may have implications for dosing.
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PMID:Creatine transporter and mitochondrial creatine kinase protein content in myopathies. 1131 79

One hundred patients presenting with exercise intolerance or rhabdomyolysis episodes have been examined successively by 31P Nuclear Magnetic Resonance Spectroscopy (MRS) of leg plantar flexor muscles with exercise test. In all cases a muscle biopsy was performed. At the end of investigations, diagnosis of a metabolic myopathy was made in 33 patients: glycogenolysis or glycolysis deficiency in 8 cases, mitochondrial myopathy in 24 cases and CPT II deficiency in one case. Muscular dystrophy or congenital myopathy were diagnosed in 6 cases. No precise etiology could be found in 30 patients with either high CK levels or muscle biopsy abnormalities. Seven patients had rhabdomyolysis related to excessive physical activities. Twenty-four patients had functional symptoms. The principal MRS parameters used for diagnosis were the values of intracellular pH at the end of exercise and the time constant of phosphocreatine resynthesis during recovery. Lack of acidosis after exercise was observed in all patients with blockade of glycogenolysis or glycolysis. A slowing in phosphocreatine resynthesis was found in 66 p.cent of patients with definite mitochondrial myopathy. The specificity of these parameters were respectively 92.4 p.cent and 85.5 p.cent for the two groups. In conclusion (31)P MRS allows the detection of muscular glycogenoses with a sensitivity close to 100 p.cent. However, its sensitivity was lower for the detection of mitochondrial myopathies, as is also known for the other in vivo metabolic investigations, reflecting the heterogeneity of expression of mitochondrial abnormalities in a given muscle. The integration of imaging in the examination protocol may help to orientate towards the diagnostic of a dystrophy in some patients.
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PMID:[Exploration of exercise intolerance by 31P NMR spectroscopy of calf muscles coupled with MRI and ergometry]. 1261 54

Creatine monohydrate (CrM) supplementation may increase strength in some types of muscular dystrophy. A recent study in myotonic muscular dystrophy type 1 (DM1) did not find a significant treatment effect, but measurements of muscle phosphocreatine (PCr) were not performed. We completed a randomized, double-blind, cross-over trial using 34 genetically confirmed adult DM1 patients without significant cognitive impairment. Participants received CrM (5 g, approximately 0.074 g/kg daily) and a placebo for each 4-month phase with a 6-week wash-out. Spirometry, manual muscle testing, quantitative isometric strength testing of handgrip, foot dorsiflexion, and knee extension, handgrip and foot dorsiflexion endurance, functional tasks, activity of daily living scales, body composition (total, bone, and fat-free mass), serum creatine kinase activity, serum creatinine concentration and clearance, and liver function tests were completed before and after each intervention, and muscle PCr/beta-adenosine triphosphate (ATP) ratios of the forearm flexor muscles were completed at the end of each phase. CrM supplementation did not increase any of the outcome measurements except for plasma creatinine concentration (but not creatinine clearance). Thus, CrM supplementation at 5 g daily does not have any effects on muscle strength, body composition, or activities of daily living in patients with DM1, perhaps because of a failure of the supplementation to increase muscle PCr/beta-ATP content.
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PMID:Creatine monohydrate supplementation does not increase muscle strength, lean body mass, or muscle phosphocreatine in patients with myotonic dystrophy type 1. 1469 98

To investigate the effects of creatine monohydrate on muscle performance and cognitive functions in muscular dystrophy patients, we made an open trial. Twenty-nine individuals, including 14 myotonic dystrophy (DM), seven facioscapurohumeral muscular dystrophy (FSHD), two limb-girdle muscular dystrophy and six healthy volunteers, were enrolled in this study and 27 participants completed it. All participants took creatine 20g/day for an initial week and 5g/day for successive eight weeks. Somatotonic measurements, global subjective assessment, muscle performance, cardiopulmonary function, cognitive function, laboratory studies and magnetic resonance spectroscopy (MRS) were evaluated at both pre and post examination. Subjective improvements were reported from twelve individuals. Contrary adverse effects were also complained from ten individuals, although all these problems were not serious. Quantitative muscle power was slightly but significantly increased in the patients and the number of the patients who failed to complete cycle ergometer test was decreased. Phosphocreatine concentrations of left calf muscle were not different between pre and post trial examination. No obvious changes were detected in cardiopulmonary assessment, cognitive function and laboratory date. Creatine has certain expectance for muscular dystrophy patients in motor performance. The effect may be achieved not only by increase of energy buffer, because clinical improvements were observed in our study nevertheless no increase was detected in phosphocreatine concentration. The usage of creatine should be managed under medical monitoring since ideal protocol has not yet been established and adverse effects can not be ignored.
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PMID:[A clinical trial of creatine monohydrate in muscular dystrophy patients]. 1556 80

In recent years, dietary supplementation with creatine has been shown to enhance neuromuscular function in several diseases. Recent studies have suggested that creatine can be beneficial in patients with muscular dystrophy and other mitochondrial cytopathies, and may attenuate sarcopenia and facilitate rehabilitation of disuse atrophy. Though the mechanisms are still unknown, creatine has been shown to decrease cytoplasmic Ca2+ levels and increase intramuscular and cerebral phosphocreatine stores, providing potential musculoskeletal and neuroprotective effects.
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PMID:Creatine monohydrate as a therapeutic aid in muscular dystrophy. 1653 85

The present review outlines the clinical potential of magnetic resonance (MR) spectroscopy of the heart. The main acquisition and postprocessing techniques of myocardial phosphorous (31P) and proton (1H) MR spectroscopy are illustrated, along with the possibilities these techniques offer for assessing the myocardial metabolism of phosphates and the presence of lipids. Particular attention is paid to the significance of the main peaks of the myocardial spectrum of 31P: phosphomonoesters (PME), inorganic phosphate (Pi), phosphodiesters (PDE), phosphocreatine (PCr), and gamma-, alpha- and beta-adenosine triphosphate (ATP). The main findings of clinical research are presented with regard to myocardial hypertrophy and hypertrophic and dilated cardiomyopathy, ischaemic cardiomyopathy and myocardial involvement in multisystem disease such as muscular dystrophy and diabetes mellitus. Lastly, the recent prospects offered by technological innovations that increase the signal-to-noise ratio and reduce acquisition times are assessed with reference to the radiologist dedicated to cardiac imaging.
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PMID:MR spectroscopy of the heart. 1717 30

Creatine and phosphocreatine serve not only as an intracellular buffer for adenosine triphosphate, but also as an energy shuttle for the movement of high-energy phosphates from mitochondrial sites of production to cytoplasmic sites of utilization. The spontaneous loss of creatine and of phosphocreatine to creatinine requires that creatine be continuously replaced; this occurs by a combination of diet and endogenous synthesis. Vegetarians obtain almost no dietary creatine. Creatine synthesis makes major demands on the metabolism of glycine, arginine, and methionine. Large doses of creatine monohydrate are widely taken, particularly by athletes, as an ergogenic supplement; creatine supplements are also taken by patients suffering from gyrate atrophy, muscular dystrophy, and neurodegenerative diseases. Children with inborn errors of creatine synthesis or transport present with severe neurological symptoms and a profound depletion of brain creatine. It is evident that creatine plays a critical, though underappreciated, role in brain function.
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PMID:Creatine: endogenous metabolite, dietary, and therapeutic supplement. 1743 86


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