Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0847097 (acidity)
 15,165 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mixtures of alginic acid and antacid, when given orally, react with gastric acid to form a viscous barrier (raft) which floats on the surface of the gastric contents. 111In was used to label magnesium alginate in order to study the effect of gastric acidity on the extent of formation of the raft. In vitro, acid concentrations less than 0.05 N diminished raft formation. In vivo, raft formation was significantly better in normal subjects who ingested dilute acid with the labeled alginate/antacid than in subjects who ingested the labeled alginate/antacid with plain water. Gastric emptying of the labeled alginate was also slowed by the presence of acidified gastric contents. These results suggest that the formation of an effective alginic acid antireflux barrier requires acidic gastric contents.
Int J Rad Appl Instrum B 1988
PMID:Use of 111In-labeled alginate to study the pH dependence of alginic acid anti-esophageal reflux barrier. 325 79

While demonstrating that the cyclic anhydride of diethylenetriaminepentaacetic acid (DTPA) may be used to covalently attach this chelator to proteins, it was necessary to develop several new procedures and techniques. We were able to show that coupled proteins may be labeled with indium-111 (111In) simply by transcomplexation from a weaker complex such as the acetate to avoid subjecting the protein, even momentarily, to the acidity of the chloride (however, we have also observed that too high a concentration of acetate and other complexing agents such as citrate will interfere with protein labeling by competing with DTPA for the radioactivity). In agreement with other investigators using bifunctional chelate methodology we have observed that trace metals may interfere with the labeling. Accordingly, we developed a simple paper chromatographic assay which may be used to establish whether trace metals are present at interfering concentrations and to identify their sources. We have also employed a hydrolyzed control assay to determine whether and to what degree the radioactivity is bound to protein other than at the DTPA groups. We have developed a simple method of measuring the average number of DTPA groups per protein molecule which involves labeling the products of coupling with 111In. Procedures used and precautions observed in the radiolabeling of proteins by these methods are discussed.
Int J Rad Appl Instrum B 1987
PMID:DTPA-coupled proteins--procedures and precautions. 342 37

Elemental selenium and tellurium, and gaseous inorganic forms of Se(IV), Se(VI), Te(IV) and Te(VI) have been determined after their adsorption on gold-coated beads. After leaching, with water and dilute hydrochloric and nitric acids, the different chemical species in each acid fraction were separated with an anion-exchange resin (Bio-Rad AG-1X8) and a cation-exchange resin (Amberlite IR-120 Plus) by varying the acidity of the leaching agent. Subsequent analysis was by graphite-fumace atomic-absorption spectrometry. The lower detection limit for Se and Te was 0.03 ng/M(3) with a precision of +/- 5%. The average amounts of selenium in interior and exterior air samples were about 4.73 and 1.93 ng/m(3) respectively. For tellurium the corresponding values were about 0.78 and 0.24 ng/m(3).
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PMID:Determination of selenium and tellurium in air by atomic-absorption spectrometry. 1896 94