Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of food on the bioavailability of nifedipine (Procardia), 10 mg capsules, was studied. Each of 15 male volunteers received a single oral 10 mg dose with 120 ml water under three conditions: fasting, after a low-fat (high-carbohydrate) meal, and after a high-fat meal. An open, three-way Latin-square design was employed with a 4-day washout period between administrations. Serial blood samples were collected just before the dose (0 hour) and from 0 to 8 hours after administration. Nifedipine assays were performed by GLC/electron capture detection. Diet did not appreciably alter the AUC from 0 to 8 hours, the AUC from 0 to infinity, or the elimination half-life. The time to peak (tmax) and peak concentrations (Cmax) were significantly altered by food. The mean Cmax values for fasting, low-fat, and high-fat meals were 78.9, 42.2, and 58.7 ng/ml, respectively. The mean tmax values for these three conditions were 0.97, 1.89, and 1.07 hours, respectively. The results indicate that food, in particular a low-fat (high-carbohydrate) meal, slows the rate but does not alter the extent of nifedipine absorption. Insofar as certain side effects (e.g., flushing and headache) may be related to the high peak plasma levels associated with rapid absorption, administration with meals might serve to reduce the incidence of such effects. Clinical trials would be necessary to confirm this possibility. For the majority of patients on routine maintenance therapeutic regimens, nifedipine capsules may be administered without regard to food intake.
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PMID:Effect of food on nifedipine pharmacokinetics. 359 68

The reaction conditions of galactose oxidase-catalyzed, targeted C-6 oxidation of galactose derivatives were optimized for aldehyde production and to minimize the formation of secondary products. Galactose oxidase, produced in transgenic Pichia pastoris carrying the galactose oxidase gene from Fusarium spp., was used as catalyst, methyl alpha-D-galactopyranoside as substrate, and reaction medium, temperature, concentration, and combinations of galactose oxidase, catalase, and horseradish peroxidase were used as variables. The reactions were followed by (1)H NMR spectroscopy and the main products isolated, characterized, and identified. An optimal combination of all the three enzymes gave aldehyde (methyl alpha-D-galacto-hexodialdo-1,5-pyranoside) in approximately 90% yield with a substrate concentration of 70 mM in water at 4 degrees C using air as oxygen source. Oxygen flushing of the reaction mixture was not necessary. The aldehyde existed as a hydrate in water. The main secondary products, a uronic acid (methyl alpha-D-galactopyranosiduronic acid) and an alpha,beta-unsaturated aldehyde (methyl 4-deoxy-alpha-D-threo-hex-4-enodialdo-1,5-pyranoside), were observed for the first time to form in parallel. Formation of uronic acid seemed to be the result of impurities in the galactose oxidase preparation. (1)H and (13)C NMR data of the products are reported for the alpha,beta-unsaturated aldehyde for the first time, and chemical shifts in DMSO-d(6) for all the products for the first time. Oxidation of D-raffinose (alpha-D-galactopyranosyl-(1-6)-alpha-D-glucopyranosyl-(1-2)-beta-D-fructofuranoside) in the same optimum conditions also proceeded well, resulting in approximately 90% yield of the corresponding aldehyde.
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PMID:Oxidation of methyl alpha-D-galactopyranoside by galactose oxidase: products formed and optimization of reaction conditions for production of aldehyde. 1906 91