Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We analyzed the serum anion gap (AG = sodium plus potassium minus chloride plus bicarbonate, N = 11-21 mEq/l), serum uric acid and urea concentrations in hyponatremia of various origins. We found that characteristic chemical patterns emerged in association with different hypotonic states: Low uric acid concentration was typically observed in the SIADH and in hyponatremia related to hypopituitarism. The same observation was also frequently noted in hyponatremia secondary to diuretics or to polydypsia. In the SIADH, we observed a decrease in the AG but to a greater extent (-26%) than one would expect from the simple dilutional effect (-16%). Fifty percent of the patients presented an AG lower than 11 mEq/l. In patients with diuretic-related hyponatremia, one group presented an hypouricemia and a low AG as in SIADH (reflecting volume expansion), in the other group the AG was normal or increased as was uric acid concentration (reflecting volume depletion). In adrenocorticotropin deficiency, hyponatremia was typically associated with a low bicarbonate concentration, a normal AG and hypouricemia. In polydypsic patients with hyponatremia, the AG was usually normal or increased despite sometimes very low sodium levels. Uric acid levels were highly variable, most often decreased. We also noted in these patients that the serum urea levels were correlated with urine osmolality (R = +0.8; p < 0.001), and in 40% of them we observed very low blood urea concentration (0.5-2 mmol/l) at the admission time. In hyponatremia related to cardiac failure or cirrhosis, the AG was usually normal despite mild hypoproteinemia.
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PMID:Uric acid, anion gap and urea concentration in the diagnostic approach to hyponatremia. 852 2

Uric acid inhibited 50% of the activity of bovine kidney low molecular mass phosphotyrosine protein phosphatase at concentrations of 1.0, 0.4, 1.3, and 0.2 mM, respectively for p-nitrophenyl phosphate (p-NPP), flavine mononucleotide, beta-naphthyl phosphate and tyrosine phosphate (Tyr-P) as substrates. The mixed type inhibition of p-NPP hydrolysis was fully reversible, with Kic and Kiu values of 0.4 and 1.1 mM, respectively; the inhibition by uric acid shifted the pH optimum from 5.0 to 6.5. When Tyr-P was the substrate, competitive inhibition was observed with a Ki value of 0.05 mM. Inhibition studies by uric acid in the presence of thiol compounds, and preincubation studies in the presence of inorganic phosphate suggest that the interaction of uric acid with the enzyme occurred at the active site, but did not involve SH residues, and that the mechanism of inhibition depended on the structure of the substrates.
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PMID:Inhibition of bovine kidney low molecular mass phosphotyrosine protein phosphatase by uric acid. 1268 51

Gout, a common inflammatory arthritis, can be diagnosed with absolute certainty. Gout results from the body's reaction to urate crystals deposited in tissues, and this pathophysiology is well understood. If used appropriately, available therapies can be entirely effective in not only treating the symptoms of gout, but also in eliminating the excess urate from the body, thereby eradicating the disease. Because of these facts, management of patients with gout should be successful. However, management of gout is particularly challenging in the elderly, even though the principles of management are the same for all age groups. The purpose of this article is to review these principles and discuss them as they pertain to the elderly. The classic gout attack is acute in onset, extremely painful and associated with marked swelling, warmth, erythema and tenderness of a single joint. However, the diagnosis of gout may be challenging in the elderly because atypical presentations are more common in this group. Treatment of acute gout involves the use of NSAIDs, colchicine, corticosteroids or corticotropin (adrenocorticotropic hormone). Unfortunately, co-morbid conditions such as chronic kidney disease, peptic ulcer disease and congestive heart failure may make the use of these agents dangerous or contraindicated. Thus, it is important to try to treat an acute flare of gout at the earliest sign, because the sooner treatment is initiated, the faster the inflammation will resolve. Urate-lowering agents include allopurinol and uricosuric agents. These also must be used judiciously in the elderly. However, if used at the lowest dose that maintains the serum urate level below 5.0-6.0 mg/dL, the excess urate in the body will be eliminated, acute flares will no longer occur and tophi will resolve. Gout is often seen in association with hypertension, excessive alcohol consumption, obesity and hypertriglyceridaemia. These conditions and the medications used to treat them may contribute to the hyperuricaemia. Treating these conditions and using medications that do not promote hyperuricaemia will aid in the management of gout. Despite the challenges that often complicate the management of gout in the elderly, an understanding of the pathophysiology of the disease and both the indications and limitations of the medications used should allow successful treatment.
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PMID:Management of gout in older adults: barriers to optimal control. 1723 45