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)

We report specific findings in the imipramine/serotonin animal model that are consistent with sarcolemmal membrane alterations. Among these findings are cytoplasmic enzyme release, diminished uptake of alpha-aminoisobutyrate (an amino acid analog), decreased oxygen consumption in isolated rat diaphragm, and ribosuria. Furthermore, we describe for the first time the release of the MB isoenzyme of creatine kinase from a source other than cardiac tissue; that is, isolated diaphragms from imipramine/serotonin-treated animals release increased amounts of MB isoenzyme as compared to diaphragms from control animals. We believe the similarities between this animal model and the human disease (Duchenne muscular dystrophy) support a genetically determined generalized membrane abnormality in the pathogenesis of this form of muscular dystrophy.
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PMID:Sarcolemmal membrane changes related to enzyme release in the imipramine/serotonin experimental animal model. 13 59

Studies were carried out to examine oxidative phosphorylation, cation uptake, and electrokinetic properties of liver mitochondria from genetically dystrophic mice in comparison with those from livers of littermate controls. While no differences were seen with respect to the rates of substrate oxidation, ADP/oxygen ratio, and RCl and cytochrome content, the mitochondria from the dystropic group were characterized by an elevated basal ATPase activity in the presence of NaCl. Additionally, these mitochondria were highly sensitive to high concentrations of exogenously added K+ that, besides stimulating state 4 respiration, caused uncoupling in the mitochondria. These mitochondria accumulated Ca2+ at a higher rate, and unlike the controls, Ca2+ uptake was not sensitive to exogenously added K+. It was also observed that the net negative charge on mitochondria decreased significantly in the dystrophic state. It is thus apparent that muscular dystrophy manifests itself also in terms of alteration in the membrane properties of liver mitochondria.
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PMID:Energy coupling in liver mitochondria from dystrophic mice: differential sensitivity of oxidative phosphorylation and Ca2+ uptake to K+. 14 26

To determine effects of severe muscular dystrophy on the performance of dynamic exercise, cardiorespiratory responses to incremental work on a bicycle ergometer and isokinetic limb strength measurements were compared for 13 dystrophic boys and 13 normal, untrained boys. The dystrophic boys (D) were matched to the normal boys (N) on the basis of age (8.4 yr), height (125 cm) and weight (25.7 kg). At rest, the dystrophic group had higher heart rates (HR) (D = 102; D = 31; N = 39 ml), with no difference in oxygen uptake (VO2), calculated cardiac output (Q), pulmonary ventilation (VE), or respiratory exchange ratio (R). During submaximal work, VO2, SV, Q and VE were lower in D. During maximal work, D had lower peak values for work rate (D = 400; N = 600 kg/min), endurance (D = 41; N = 60 ml), Q (D = 5.2; N = 11.0 liters/min), VE (D = 8.2; N = 36.9 liters/min), and R (D = 0.84; N = 0.99). Arm and leg strengths (four flexion and four extension motions) were lower in D, but muscle girths were not necessarily smaller. The findings indicate exercise performance in D was below normal and limited by low cardiorespiratory capacities, diminished leg strength, and perhaps reduced peripheral oxygen utilization. Duchenne muscular dystrophy, even in its early stages, apparently affects the work capacity of cardiac and pulmonary muscles as well as limb muscles.
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PMID:Exercise performance in 6-to-11-year-old boys with Duchenne muscular dystrophy. 85 90

This article reports on a 2-week trip in a motor home through the southeastern United States with an oxygen- and ventilator-dependent young woman with muscular dystrophy. The article describes the planning, implementation, and evaluation of traveling with technology. Discussed are the amount and types of equipment and supplies to take on such a trip, modification of equipment and the motor home, the roles and responsibilities of the nurses, interactions with the client and family, and legal issues. The impact of the trip on the client's behavior--which was to transform her from a passive recipient of care to an actively involved participant--is reported.
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PMID:Traveling with technology. 158 44

A 9 year old male previously diagnosed as progressive muscular dystrophy whose serum CPK5430IU.l-1 was very high received general anesthesia. Before anesthesia, dantrolene sodium 2 mg.kg-1 was given. Anesthesia was induced with thiamylal 100 mg and vecuronium bromide 3 mg. Anesthesia was maintained with sevoflurane (0.5%) in nitrous oxide (66%) and oxygen (33%). The course of anesthesia was uneventful. The operative time was 80 minutes. At the end of the operation, the patient recovered smoothly from anesthesia. A 46 year old female with dystrophia myotonia also received general anesthesia. The patient was diagnosed as having this disease 26 years previously. Preoperatively, the patient was suspected to have cardiac damage. Anesthesia was induced with thiamylal 100 mg, fentanyl 100 micrograms, midazolam 5 mg and vecuronium bromide 4 mg, and maintained with sevoflurane (1.0%) in nitrous oxide (66%) and oxygen (33%). Anesthesia was uneventful, but at the end of the operation, the patient could not breath fully by herself. She was placed on a ventilator and observed carefully. The endotracheal tube was removed 150 minutes after the induction of anesthesia. In these two cases, sevoflurane and vecuronium bromide were used safely.
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PMID:[General anesthesia with sevoflurane and vecuronium for patients with dystrophia myotonica and progressive muscular dystrophy]. 168

A number of active oxygen species are likely implicated in the etiology or manifestation of several pathological conditions, including aging, arthritis, carcinogenesis, atherosclerosis, and muscular dystrophy. Ascorbate plays a key role in protecting cells against oxidative damage. Paradoxically, in the presence of Fe3+ or Cu2+, ascorbate can promote the generation of the same reactive oxygen species (.OH, O2-, H2O2, and ferryl ion) it is known to destroy. This prooxidant activity derives from the ability of ascorbate to reduce Fe3+ or Cu2+ to Fe2+ or Cu+, respectively, and to reduce O2 to O2-. and H2O2. Damage to nucleic acid and proteins results from the binding of either Fe2+ or Cu+ to metal binding sites on these macromolecules followed by reaction of the metal complexes with H2O2; this leads to the production of active oxygen species that attack functional groups at or near the metal binding sites.
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PMID:Ascorbic acid and oxidative inactivation of proteins. 196 58

In the presence of O2, Fe(III) or Cu(II), and an appropriate electron donor, a number of enzymic and nonenzymic oxygen free radical-generating systems are able to catalyze the oxidative modification of proteins. Whereas random, global modification of many different amino acid residues and extensive fragmentation occurs when proteins are exposed to oxygen radicals produced by high energy radiation, only one or a few amino acid residues are modified and relatively little peptide bond cleavage occurs when proteins are exposed to metal-catalyzed oxidation (MCO) systems. The available evidence indicates that the MCO systems catalyze the reduction of Fe(III) to Fe(II) and of O2 to H2O2 and that these products react at metal-binding sites on the protein to produce active oxygen (free radical?) species (viz; OH, ferryl ion) which attack the side chains of amino acid residues at the metal-binding site. Among other modifications, carbonyl derivatives of some amino acid residues are formed; prolyl and arginyl residues are converted to glutamylsemialdehyde residues, lysyl residues are likely converted to 2-amino-adipylsemialdehyde residues; histidyl residues are converted to asparagine and/or aspartyl residues; prolyl residues are converted to glutamyl or pyroglutamyl residues; methionyl residues are converted to methionylsulfoxide residues; and cysteinyl residues to mixed-disulfide derivatives. The biological significance of these metal ion-catalyzed reactions is highlighted by the demonstration: (i) that oxidative modification of proteins "marks" them for degradation by most common proteases and especially by the cytosolic multicatalytic proteinase from mammalian cells; (ii) protein oxidation contributes substantially to the intracellular pool of catalytically inactive and less active, thermolabile forms of enzymes which accumulate in cells during aging, oxidative stress, and in various pathological states, including premature aging diseases (progeria, Werner's syndrome), muscular dystrophy, rheumatoid arthritis, cataractogenesis, chronic alcohol toxicity, pulmonary emphysema, and during tissue injury provoked by ischemia-reperfusion. Furthermore, the metal ion-catalyzed protein oxidation is the basis of biological mechanisms for regulating changes in enzyme levels in response to shifts from anaerobic to aerobic metabolism, and probably from one nutritional state to another. It is also involved in the killing of bacteria by neutrophils and in the loss of neutrophil function following repeated cycles of respiratory burst activity.
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PMID:Metal ion-catalyzed oxidation of proteins: biochemical mechanism and biological consequences. 228 87

The study of skeletal muscle disorders is providing potentially important insights into regulatory mechanisms in human exercise and fatigue and information useful for diagnostic and treatment purposes. This review primarily concerned the general metabolic and physiological factors which set upper limits to performance of various types of exercise in patients with a variety of muscle disorders. From the standpoint of exercise performance, skeletal muscle diseases can be classified into three major groups. One group consists of primary disorders of muscle energy metabolism, including defects in muscle carbohydrate and lipid metabolism, disorders of mitochondrial electron transport, and abnormalities of purine nucleotide metabolism. Exercise performance largely reflects the capacity for ATP resynthesis. Oxidative phosphorylation is the dominant quantitative source of energy for ATP resynthesis under most exercise conditions. Consequently, patients with disordered oxidative metabolism (i.e., patients with defects in the availability or utilization of oxidizable substrate, such as those with phosphorylase or PFK deficiency or those with defects in mitochondrial electron transport) typically demonstrate severely impaired exercise performance. Intolerance to sustained exercise and premature fatigability are salient features of muscle oxidative disorders. Maximal oxygen uptake and maximal a-v O2 difference are markedly subnormal related to an attenuated muscle oxygen extraction. Muscle weakness and atrophy are less common. Anaerobic muscle performance is dramatically limited in patients with virtually complete defects of glycogenolysis/glycolysis but appears relatively normal in those with electron transport defects. A second major group of disorders includes patients with decreased muscle mass due to muscle necrosis, atrophy, and replacement of muscle by fat and connective tissue. These disorders are exemplified by the various muscular dystrophies (Duchenne's dystrophy, Becker's dystrophy, LG dystrophy, FSH dystrophy, and myotonic dystrophy) in which exercise performance is severely impaired due to muscle wasting and weakness in spite of largely normal pathways for muscle ATP resynthesis. In muscular dystrophy patients, the degree to which maximal oxygen uptake and anaerobic muscle performance are impaired appears to be a function of the severity of muscle weakness and atrophy. A third group of disorders includes patients with impaired activation of muscle contraction or relaxation. These disorders may be considered in two subcategories. In the first, impaired activation or relaxation of contractile activity is due to intrinsic muscle dysfunction (e.g., diseases associated with myotonia or periodic paralysis). In the second subcategory, there is impaired muscle activation due to a primary abnormality in the central nervous system, motor nerves, or neuromuscular junction.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Skeletal muscle disorders and associated factors that limit exercise performance. 267 57

Muscular dystrophy patients fall in respiratory failure in the terminal stage. Erythrocyte 2,3-diphosphoglycerate (2,3-DPG) is an important regulator of oxygen release, as it affects the position of the oxyhemoglobin dissociation curve. In order to survey the internal respiration in these patients, we studied the erythrocyte 2,3-DPG which regulates oxygen transport function. The concentration of erythrocyte 2,3-DPG was determined in 27 cases with Duchenne type muscular dystrophy and 10 cases with myotonic dystrophy (MyD). We analyzed the relation of erythrocyte 2,3-DPG to spirogram, arterial blood gas and acid-base analysis in these patients. 14 normal males were used as controls. In control subjects, the mean concentration ratio of 2,3-DPG and hemoglobin (DPG/Hb) was 0.880 +/- 0.072. 18 cases of DMD and 9 of MyD, which showed more than 45 torr of Pco2 in arterial blood gas, revealed 0.823 +/- 0.053 and 0.814 +/- 0.092 of DPG/Hb respectively. These values were significantly lower than that of controls. DPG/Hb correlated to % VC, Pao2, Paco2, pH, HCO3 and BE in DMD, but no relation to these parameters in MyD. The low ratio of DPG/Hb in erythrocyte was considered to be metabolic compensation of respiratory failure in DMD. On the other hand, 2,3-DPG of MyD seemed to be also affected by any other factors in addition to respiratory failure.
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PMID:[Erythrocyte 2,3-diphosphoglycerate in muscular dystrophy]. 275 52

The effects of noninvasive nasal mask-assisted ventilation were studied in two patients with chronic respiratory failure due to Duchenne's muscular dystrophy. Observations were made with continuous recordings of transcutaneous CO2 and O2 and ear oximetry. In one case, the mean tcPCO2 fell from 72 mm Hg to 43 mm Hg. The tcPO2 increased from 38 mm Hg to 62 mm Hg without supplementary oxygen. In the second case, hypercapnia associated with supplementary oxygen was corrected, and at five months' follow-up, hypoxemia was corrected without supplementary oxygen. Prolonged therapy during sleep has resulted in sustained clinical improvement for more than 18 months.
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PMID:Noninvasive nasal mask-assisted ventilation in respiratory failure of Duchenne muscular dystrophy. 328 48


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