Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q9UMR3 (NMR)
 150,598 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

NMR relaxation times have been used to characterize molecular motion and intermolecular complexes in the aqueous phase of bovine chromaffin granules. Partially relaxed 13C and proton spectra have been obtained at 3 and 25 degrees C. T1 measurements of five protonated carbons on epinephrine (C2, C5, C6, CHOH and NCH3) give a correlation time of 0.15 (10(-9)) s at 25 degrees C for the catechol ring and methine carbon, while the effective correlation time for the NCH3 group is somewhat shorter due to its internal degree of rotational freedom. Resonances of protonated carbons on the soluble protein chromogranin give very similar correlation times: 0.20 (10(-9)) s for the peptide alpha-carbon and 0.2 (10(-9)) s for the methylene sidechain carbons of glutamic acid. The correlation time (tauR) of ATP was not measured directly using 13C T1 data due to the weakness of its spectrum, but its reorientation appears to be substantially slower than that of epinephrine or chromogranin. This conclusion is based on three observations: (1) the qualitative temperature dependence of T1 for H2 and H8 on the adenine ring places tauR for ATP to the right of the T1 minimum, or tauR greater than or equal to 1.0 (10(-9)) s; (2) 13C-resonances of ATP have anomalously low amplitudes compared with epinephrine resonances, a fact that is readily explained only if ATP undergoes substantially slower reorientation; and (3) a comparison of the T1 data of H8 in chromaffin granules and in a dilute aqueous solution, where tauR for ATP can be measured directly indicates that tauR approximately 1.0 (10(-9)) s at 25 degrees C in the granules. The relaxation data are consistent with the concept of a storage complex based on electrostatic interactions between a polyion (chromogranin) and its counterions (ATP and epinephrine), in which ATP cross-links cationic sidechains of the protein.
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PMID:Molecular mobilities of soluble components in the aqueous phase of chromaffin granules. 84 82

The most common ectopic production of a pituitary hormone is the one of ACTH leading to Cushing's syndrome. Ectopic ACTH-hypersecretion is the cause of Cushing's syndrome in 10-15% of all cases. The ACTH-secreting tumours are often oat-cell carcinomas of the lung, less frequently pancreatic cancers, hypernephromas, or C-cell carcinomas of the thyroid. Some of these tumours may be benign or semi-benign as the rare carcinoid tumours and cause great problems in the differential diagnosis of ACTH-dependent hypercortisolism. Out of 173 of our patients with Cushing's syndrome observed in the last 12 years 21 were caused by ectopic ACTH-production. Of these 21 patients 13 have a small cell carcinoma of the lung. The ectopic ACTH-syndrome often has typical clinical features caused by the levels of ACTH and cortisol leading to hypocalcemic alkalosis with muscle weakness and wasting, carbohydrate intolerance, and hypertension with oedema. The survival time in many of these patients is not long enough to allow them to develop typical signs of Cushing's syndrome though they are often highly pigmented. These patients are easily diagnosed. However, patients with small tumours which do not cause very elevated ACTH-levels and who have the more typical clinical signs of full-blown Cushing's syndrome are difficult to recognize. For the differential diagnosis of ACTH-dependent Cushing's syndrome the corticotropin-releasing hormone (CRH) stimulation test and dexamethasone suppression test with high doses are helpful. In special cases the venous sampling procedure for ACTH-measurements is necessary, also CT or NMR is helpful. Ectopic CRH-production is a rare cause of ACTH-dependent Cushing's syndrome. Patients with ectopic CRH-production and consecutive ACTH-hypersecretion from the pituitary have not been studied extensively. There are especially no well documented results of the use of the CRH-stimulation test in vivo in this group of patients with Cushing's syndrome. On the other hand, in the documented cases, not only CRH-, but also ACTH-production was found in the tumours. So far, this rare cause of ACTH-dependent Cushing's syndrome has to be excluded or confirmed by the measurement of endogenous CRH-levels. But until now we have not been able to detect one single case of ectopic CRH-production using a sensitive homologous CRH-radioimmunoassay over a period of more than 8 years in which we have seen nearly 120 newly diagnosed patients with ACTH-dependent Cushing's syndrome. Only in the plasma and tumour tissue of two patients of other groups have we found high CRH-levels.
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PMID:Ectopic production of ACTH and corticotropin-releasing hormone (CRH). 132 73

Uremic patients often complain of fatigue and muscle weakness. In order to elucidate the abnormalities of energy metabolism in the muscles of such patients, we measured the concentrations of phosphocreatine (PCr), inorganic phosphate (Pi) and adenosine triphosphate (ATP) as well as the intracellular pH in skeletal muscles by 31P-NMR at rest, during aerobic and anaerobic exercise and during recovery in 15 uremic patients (7 non-dialyzed patients and 8 dialyzed patients) and 6 control subjects. At rest, there was no difference in intracellular pH between the uremic patients and controls, but the concentrations of PCr and ATP in the skeletal muscle were lower in the uremic patients. However, during aerobic exercise, the uremic patients showed a rapid decrease in intracellular pH and a delay in its recovery. They also revealed an increased PCr utilization during aerobic exercise and its delayed resynthesis during recovery. During anaerobic exercise, the uremic patients, especially non-dialyzed patients, displayed a slower decrease in pH than the controls and a delay in its recovery. An increased PCr utilization during anaerobic exercise and a delayed resynthesis during recovery were also demonstrated. These findings suggest that the aerobic and anaerobic energy productions in uremic patients are impaired and that the energy production of the muscle depends on anaerobic glycolysis during exercise. Hemodialysis apparently facilitates recovery of the inhibited enzyme activities of oxidative phosphorylation and glycolysis in uremic patients.
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PMID:Impaired muscle energy metabolism in uremia as monitored by 31P-NMR. 203 34

For many years, a number of laboratories have been working on the applications of very low field NMR. In 1985, our laboratory presented the first NMR images using the earth's magnetic field. However, the use of this technique was limited by the weakness of the signal and the disturbing effects of the environment on the signal-to-noise ratio and on the homogeneity of the static magnetic field. Therefore experiments has to be performed in places with low environmental disturbances, such as open country or large parks. In 1986, we installed a new station in Lyon, in the town's hostile environment. Good NMR signals can now be obtained (with a signal-to-noise ratio better than 200 and a time constant T2 better than 3s for 200-mnl water samples and at a temperature of about 40 degrees C). We report the terrace roof of our faculty building. Gradient coils were used to correct the local inhomogeneities of the earth's magnetic field. We show FIDs and MR images of water-filled tubes made with or without these improvements.
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PMID:Environmental optimization and shielding for NMR experiments and imaging in the earth's magnetic field. 231 18

Two brothers with motor retardation since the first months of life presented waddling ataxic-gait with lumbar lordosis, joint contractures and generalized muscle weakness. Both presented altered cerebellar tests and scanning speech. Creatine kinase, electromyography (EMG) and muscle biopsy pointed to muscular disease while CT scanning and NMR imaging showed cerebellar vermis agenesis. On this evidence we diagnosed the unusual association of vermian agenesis and congenital muscular dystrophy.
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PMID:Congenital muscular dystrophy and cerebellar vermis agenesis in two brothers. 321 50

Twelve cases of benign extramedullary tumors in the high cervical region and at the foramen magnum were experienced during past five years among eighty all spinal and paraspinal tumors. The diagnosis of masses in this region is very difficult because of the variety of clinical course, symptoms and neurological findings as pointed out by many reporters. Also in our cases, 70% of the patients complained of the deteriorated motor weakness of the upper or lower extremities on admission, though they had noticed the onset of slight neck or occipital pain a few years ago. Neurological examination on admission clearly showed the symptom of myelopathy except in two cases with a tumor at the foramen magnum and C1 level. The percentage of positive findings of plain X-rays was 50%, that of metrizamide myelography was 92% and that of IV. e. CT and met. e. CT was 100%. NMR-CT was performed in 2 cases, and in one of them it was useful in confirming the tumor configuration and extension. Five interesting cases were described mainly from the neuroradiological aspects. Finally the differentiation between meningioma and neurinoma was discussed from the aspects of myelogram, CT and NMR-CT. As already pointed out, it is most important not to forget the existence of tumors in this region when one comes across the confused symptoms, afterwards not to overlook the slight positive neurological and neuroradiological findings.
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PMID:[Neuroradiological evaluation of benign extramedullary tumors in the high cervical region and at the foramen magnum]. 376 52

Mitochondrial myopathies are a clinical condition characterized by muscle weakness and fatigue in which the primary defect is localized at the level of the mitochondria. Microscopic examination shows accumulations of mitochondria at the fibre periphery (ragged red fibres) and in some cases mitochondrial paracrystalline inclusions. The spectrum of different mitochondrial defects so far described is reviewed and data from cases investigated in this laboratory are described. The first case was a 17-year-old boy with a multisystem disorder whose muscle mitochondria showed low respiratory activity with all substrates, which doubled in the presence of uncoupler. Further investigation showed that the mitochondrial ATPase activity was only 6% of normal. The next cases were a mother and daughter who showed a typical lipid storage myopathy. The latter was treated successfully with oral carnitine but the myopathy persisted. Mitochondrial investigations indicated a low respiratory activity with NAD-linked substrates but normal activity with succinate and ascorbate + TMPD. A defect in the NADH-CoQ reductase section of the respiratory chain was pinpointed possibly at an iron-sulphur centre. The fourth and fifth cases were two sisters who exhibited no lipid storage myopathy but whose mitochondrial activity was low with NAD-linked substrates but normal with succinate. Again a defect in the NADH-CoQ reductase (complex I) of the respiratory chain was determined. They were also investigated using 31P-NMR. It was found after exercise that their muscle creatine phosphate levels took seven times longer to return to pre-exercise concentrations than control subjects. These results are discussed with respect to the synthesis of mitochondrial proteins and the influence that both the mitochondrial and nuclear DNA have on this process.
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PMID:Mitochondrial myopathies: disorders of the respiratory chain and oxidative phosphorylation. 643 47

Hypothyroidism exerts a significant effect on several body systems, including the functioning of muscle and nerve. Described here is the case of a severely hypothyroid patient with weakness and numbness of the legs who showed marked clinical improvement with thyroid hormone treatment. Concurrently obtained phosphorus 31-nuclear magnetic resonance (NRM) spectra and nerve conduction studies showed changes in muscle phosphorus metabolism with increases in conduction velocities. Phosphorus 31-NMR spectroscopy is useful for evaluating metabolism in muscle in hypothyroid patients.
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PMID:Effects of thyroid hormone treatment on 31P-NMR spectroscopy of muscle and on nerve conduction studies in a patient with long-standing severe hypothyroidism. 875 77

Classical myopathic dermatomyositis (DM) is a chronic autoimmune disease characterized by an erythematous rash and severe, proximal muscle weakness. A disease variant, amyopathic DM, presents with the typical rash but without clinical evidence of muscle weakness. Prednisone and immunosuppressive drugs alleviate symptoms in many patients. Accurate longitudinal evaluations of patients are important to limit serious side effects of these drugs, including osteoporosis, cataracts, and growth inhibition. Metabolic abnormalities detected with 31P magnetic resonance spectroscopy (MRS) provide the best quantitative data for evaluating these patients. With 31P MRS, the levels of inorganic phosphate (Pi), phosphocreatine (PCr), ATP, and phosphodiesters (PDE) were determined in the quadricep muscles of patients during rest and exercise. Artificial neural network (ANN) analyses of these data were previously used for accurate classification of patients with myopathic or amyopathic DM and normal controls. In the present investigation, an artificial neural network was employed for further analysis of the 31P metabolite levels in quantitative, longitudinal evaluations of the extent (percent) of clinical improvement or deterioration during treatment with prednisone and immunosuppressive drugs. The ANN results showed that adult patients in a severe myopathic state could improve with treatment to a clinical status of amyopathic DM. In contrast, severely weak juvenile patients in the myopathic state recovered to normal status. One juvenile patient did not improve and remained in the myopathic state. Additionally, a serious clinical relapse in an amyopathic patient was predicted with serial ANN analyses well in advance of the actual clinical event. These network analyses show potential utility for clinical applications in muscle diseases.
NMR Biomed
PMID:Analysis of 31P MR spectroscopy data using artificial neural networks for longitudinal evaluation of muscle diseases: dermatomyositis. 971 79

Muscle diseases can take different clinical aspects and some unusual symptoms are often underestimated. Weakness of proximal limb muscles is the most frequent but distal weakness can be observed. Sometimes oculomotor, bulbar, facial, respiratory, paraspinal muscles or myocardium involvement may be the expression of a muscle disease. Similarly it is important to recognize a muscle disease in occurrence of neonatal hypotonia, muscle hypertrophy, muscle stiffness, transitory paralytic episodes, fatigability, myalgia, rhabdomyolysis or isolated increased creatine-kinases level. Biological and electrophysiological examinations have essentially a role in pointing a muscle disease. Muscle biopsy keeps the key role in the diagnosis. Muscle imaging allows mapping of the lesions and new techniques of NMR spectroscopy constitute an in vivo approach of muscle metabolism.
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PMID:[When should you consider a muscular disease?]. 1126 20


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