Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0262471 (ENT)
 5,307 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Optimal growth conditions have been established for production of heat-labile enterotoxin (LT) by both porcine and human strains of enterotoxigenic (ENT(+)) Escherichia coli. There were no unusual growth factor requirements, and some strains produced fairly high levels of LT in a basal salts medium containing 0.5% glucose if the pH was carefully controlled. Several amino acids markedly stimulated LT synthesis when added to the basal salts-glucose medium. Methionine and lysine were the most stimulatory for both human and porcine strains. Either aspartic acid or glutamic acid further enhanced LT synthesis in the presence of methionine and lysine, with aspartic acid being more stimulatory for porcine strains and glutamic acid more stimulatory for human strains. There were no apparent vitamin requirements and no unusual cations needed for toxin synthesis except that Fe(3+) was slightly stimulatory for porcine strains. The stimulation by Fe(3+) was observed only in the presence of the three amino acids, suggesting that the effect was indirect rather than on toxin synthesis. The carbon source also influenced the yield of LT. Glucose supported maximal synthesis, but other carbon sources which exhibit a high degree of catabolite repression also supported high levels of synthesis. Little or no LT was released below pH 7.0; therefore, because the pH drops during growth from 7.5 to 6.8, even in highly buffered media, it was necessary to adjust the pH to 8.0 to effect complete release of cell-associated toxin. The defined medium containing three amino acids reduced the amount of UV-absorbing material in culture supernatants about fivefold and increased LT activity for various strains from two- to fivefold over a complex Casamino Acids-yeast extract medium. Conditions found to be optimal for synthesis of LT were inhibitory for the heat-stable enterotoxin.
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PMID:Nutritional requirements for synthesis of heat-labile enterotoxin by enterotoxigenic strains of Escherichia coli. 3

The symptom tinnitus may be due to a number of causes. Pathological processes within the sense-organ "ear" as well as non-otologic diseases may result in tinnitus. Therefore a thorough ENT diagnosis is necessary. The evaluation of the patient includes the history, ENT-status examination, audiological and vestibular findings, imaging investigations and, if necessary, examinations by other specialists. The therapy of tinnitus is difficult. If possible, the therapy should be causally orientated. Mostly, this is only the case with tinnitus caused by diseases of the external and middle ear. The therapeutic aim is the compensation of tinnitus. The most common type of tinnitus is of cochlear-synaptic origin. According to results of inner ear research new possibilities of pharmacologically influencing the cochlear synapse have been found. By intravenous application of the specific Quisqualate antagonist glutamic acid diethyl ester (GDEE) 77.2% of our patients with cochlear synaptic tinnitus noted a tinnitus reduction.
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PMID:[Tinnitus: causes, diagnosis, therapy]. 152 18