Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two brothers with hyperdibasicaminoaciduria and postprandial hyperammonemia showed characteristics of lysinuric protein intolerance. Intravenous alanine load produced hyperammonemia that was aborted by oral supplementation with arginine in one brother but not in the other, although both patients had almost the same intestinal malabsorption of arginine. This occurrence suggests that even a small amount of arginine, when absorbed into the blood, can normalize the affected ammonia metabolism of lysinuric protein intolerance. Two patients with cystinuria developed marked hyperammonemia when they received an intravenous alanine load after a 19-hour fast. As both patients displayed a reduced plasma concentration of arginine and ornithine at this time, the hyperammonemia was assumed to arise from the low plasma amino acid level. It seems likely that a decrease in plasma levels of urea cycle substrate causes a failure of the tissue urea cycle metabolism. Thus the impaired ammonia metabolism in lysinuric protein intolerance would be attributed to the low plasma arginine and ornithine levels.
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PMID:Hyperammonemia in lysinuric protein intolerance. 642 86

Transport proteins such as channels and transporters play important roles in the maintenance of intracellular homeostasis. Genes for transport proteins have been cloned one after the other in recent years, and mutations in these transport protein genes have been identified in the pathogenesis of a number of hereditary diseases. These diseases include Liddle's syndrome, long QT syndrome, hyperkalemic periodic paralysis, cystic fibrosis, myotonia congenita, nephrogenic diabetes inspidus, glucose/galactose malabsorption, cystinuria, and Wilson's disease. Gene mutations in several receptors, including vasopressin V2 receptor, dihydropyridine receptor, and Ca2+ -sensing receptor, also cause disorders of membrane transport, leading to diseases. Further advances in basic science are expected to provide us with a detailed understanding of the abnormality in the 3rd/4th structure of mutated transport proteins.
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PMID:[Diseases caused by disorders of membrane transport: an overview]. 890 8

Over the past 10 years, major progress has been made in the knowledge of urinary lithogenesis, including the potential pathogenetic role of Randall's plaques and renal tubular crystal retention. Urine supersaturation is the driving force of this process and can be induced by some risk factors, including low urine volume, high urinary excretion of calcium oxalate and uric acid and low urinary excretion of citrate. Primary hypercalciuria can be due to intestinal overabsorption renal leak and bone reabsorption of calcium. Prophilaxis is mainly conducted with thiazides and low calcium diet which is indicated only in the intestinal form. Primary hyperoxaluria is treated with pyridoxine and may require in the severe forms simultaneous renal and liver transplantation. Enteric hyperoxaluria is secondary to fatty acids malabsorption and requires diet, oral calcium and cholestiramine. Hyperuricosuria is caused by diet endogenous overproduction, mainly due to enzymatic defects or high renal excretion of uric acid. Urine alkalinization with K or K and Mg citrate can prevent stone formation even in idiopathic uric acid nephrolithiasis, in which a defect of urine acidification is supposed to be the main abnormality, and in hypocitraturic patients. Cystinuria is a rare inherited defect with an intense clinical impact. It can be classified in three forms and urinary stone formation is the role. Increased solubility and conversion of cystine in a more soluble form are the main goals of the prophylaxis which includes K citrate and thiol agents administration. Tiopronin is preferred to D-penicillamine due to its lower side effects.
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PMID:[Nephrolithiasis: metabolic defects and terapeutic implications]. 2474 15