Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018099 (gout)
 5,192 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

THE CONCEPT OF AN ABNORMALITY OF GLUTAMINE METABOLISM IN PRIMARY GOUT WAS FIRST PROPOSED ON THE BASIS OF ISOTOPE DATA: when [(15)N]glycine was administered to gouty subjects, there was disproportionately great enrichment of N-(3 + 9) of uric acid, which derive from the amide-N of glutamine. An unduly high concentration of (15)N in glutamine was postulated, and attributed to a hypothetical defect in catabolism of glutamine. Excess glutamine was proposed as the driving force of uric acid overproduction. WE HAVE REEXAMINED THIS PROPOSITION IN FOUR GOUTY SUBJECTS: one mild overproducer of uric acid with "idiopathic gout," one marked overproducer with high-grade but "partial" hypoxanthine-guanine phosphoribosyl-transferase deficiency, and two extraordinary overproducers with superactive phosphoribosylpyrophosphate synthetases. In the last three, the driving force of excessive purine biosynthesis is a known surplus of alpha-5-phosphoribosyl-1-pyrophosphate. Disproportionately high labeling of N-(3 + 9) was present in all four gouty subjects, most marked in the most flamboyant overproducers. The precursor glucine pool was sampled by periodic administration of benzoic acid and isolation of urinary hippuric acid. Similarly, the precursor glutamine pool was sampled by periodic administration of phenylacetic acid and isolation of the amide-N of urinary phenylacetylglutamine. The time course of (15)N enrichment of hippurate differed from that of the amide-N of glutamine. Whereas initial enrichment values of hippurate were very high, those of glutamine-amide-N were low, increasing to a maximum at about 3 h, and then declining less rapidly than those of hippurate. However, enrichment values of hippurate and of phenacetyl glutamine were normal in all of the gouty subjects studied. Thus, preferential enrichment of N-(3 + 9) in gouty overproducers given [(15)N]glycine does not necessarily reflect a specific abnormality of glutamine metabolism, but rather appears to be a kinetic phenomenon associated with accelerated purine biosynthesis per se.In addition, greater enrichment of N-9 than of N-3 on days 1 and 2 provided suggestive evidence for a second pathway for synthesis of the initial precursor of purine biosynthesis, phosphoribosylamine, perhaps utilizing ammonia rather than the amide-N of glutamine as nitrogen donor. In this limited study, the activity of this potential second pathway did not appear to be selectively increased in gout.
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PMID:The kinetics of intramolecular distribution of 15N in uric acid after administration of (15N) glycine. A reappraisal of the significance of preferential labeling of N-(3+9) of uric acid in primary gout. 435 99

If Dr. Sydenham could have benefited from today's therapy, he likely would not have had to endure thirty years of "violent ... torture" that gave birth to his most elegant and classic description of acute gout. The five key points to remember in management of the gouty spectrum are: (1) Establish the diagnosis as clearly as possible or as clearly as seems necessary under the clinical circumstances (i.e. arthrocentesis with crystal analysis to establish diagnosis is not always necessary with reliable patients when septic joint seems highly unlikely). (2) Treat acute attacks with NSAIDs alone or perhaps steroids--or rarely IV colchicine under special circumstances. (3) DO NOT START ALLOPURINOL OR PROBENECID DURING AN ACUTE FLARE OF GOUT--IT MAY MAKE THE EPISODE WORSE. (4) The pattern of disease over time (frequency and severity of attacks) determines whether or not one decides to use an agent such as allopurinol, probenecid, or prophylactic colchicine chronically once a patient is over the acute attack--the mere presence of increased uric acid and a single or rare gouty attack would not usually require any other than the appropriate acute therapy. (5) The presence of visible tophi, uric acid renal calculi and destructive gouty arthritis nearly always warrant uric acid lowering therapy.
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PMID:Gout: modern management of an ancient malady. 851 62