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Biomedical subjects

T Uno

Publications and source records attributed to T Uno.

At least 235 records · Page 13Linked to original sources
PubMed1980

Chromatographic analysis and pharmacokinetic investigation of cephaloglycin and its metabolites in man.

Metabolism and pharmacokinetics of cephaloglycin in man were investigated. High performance liquid chromatographic and gas chromatographic-mass spectrometric analyses of metabolites excreted in human urine following oral administration of cephaloglycin revealed that cephaloglycin was biotransformed in two pathways i.e. elimination of 3-acetyl group and hydrolysis of side chain amide linkage. The former yielded deacetylcephaloglycin, a part of which further underwent lactonization to deacetylcephaloglycin lactone, and the latter led to benzoyl formic acid via phenylglycine. The urinary excretion amounts of these metabolites and intact cephaloglycin were determined by a reversed phase ion pair high performance liquid chromatography. The average total excretion amounts at infinite time accounted for 0.50% of the administered dose for intact cephaloglycin, 17.09% for deacetylcephaloglycin, 0.35% for deacetylcephaloglycin lactone, and 0.86% for benzoyl formic acid. The excretion of phenylglycine was less than 0.2%, its chromatographic peak being too small to allow accurate determination. The rate constants for absorption, metabolism, and urinary excretion were estimated by the moment analysis of the excretion rate-time curves.

Adult↗
PubMed1979

Characteristics of lithium iodide-containing poly(ethylene glycol) as a gas chromatographic stationary phase, and its application to analysis of amidic drugs.

The characteristics of lithium iodide-containing poly(ethylene glycol) as a gas chromatographic stationary phase have been evaluated in terms of partial free energy of transfer (delta G t0) from poly(ethylene glycol) to the lithium iodide-poly(ethylene glycol) system for a variaty of amides (n-fatty acid amides, lactams, benzamides, anilides, nicotinamides, isonicotinamides, barbiturates, pyrazolones) and several amines. The changes in relative retention and resolution of two solute peaks caused by the addition of lithium iodide to poly)ethylene glycol) are correlated with the difference in their delta Gt0 values. The application to the specific separation of some amidic drugs is demonstrated.

Amides↗
PubMed1979

High-performance liquid chromatographic analyses of sulbenicillin and carbenicillin in human urine.

A high-performance liquid chromatographic method has been developed for the determination of sulbenicillin (SBPC) and carbenicillin (CBPC) excreted in human urine. The method uses reversed-phase ion-pair chromatography with a bonded hydrophobic stationary phase and methanol-tetra-n-butylammonium bromide solution as the mobile phase. Urine is filtered through a micropore membrane and the filtrate introduced directly into a liquid chromatograph. An in vivo experiment was conducted by administering intravenously 1 g of SBPC or CBPC to volunteers and analysing their urine. One-compartment model analysis of the time-course data revealed that 73.1% of the amount of SBPC dosed was excreted in the urine with a rate constant of 0.579 h-1, and 91.5% of CBPC with a rate constant of 0.845 h-1.

Carbenicillin↗
PubMed1979

Two infant deaths after inhaling baby powder.

The clinical course of two baby girls who died following accidental inhalation of baby powder is described. Frequent tracheobroncheal lavage was not effective therapy. An experiment using eight mice revealed that the inhalation of baby powder was fatal. Possible treatments, including tracheobroncheal lavage with saline solution and application of chelating agents, are discussed.

Airway Obstruction↗
PubMed1979

Acidic degredation of cephaloglycin and high performance liquid chromatographic determination of deacetylcephaloglycin in human urine.

In order to provide fundamental knowledge about the determination of deacetylcephaloglycin excreted in human urine as an active metabolite of cephaloglycin, the degradation of cephaloglycin in acidic media has been investigated with varying reaction temperature between 30 degrees and 50 degrees C and pH between 1.2 and 2.8. The degradation pathway observed under these conditions was the elimination of the 3-acetyl group yielding deacetylcephaloglycin followed by formation of deacetylcephaloglycin lactone. Estimation of first order rate constants revealed that deacetylation is the rate-determining step for the degradation of cephaloglycin to the lactone. It is found from the kinetic results that reproducible assays of deacetylcephaloglycin excreted in urine can be achieved by a quantitative conversion to deacetylcephaloglycin lactone in a medium of pH 1.4 at 37 degrees C for 2 hours, followed by a reversed-phase ion-pair high-performance liquid chromatography. The utility of the present method is demonstrated by determining the time course of urinary excretion of deacetylcephaloglycin after oral administration of cephaloglycin capsule.

Acids↗
PubMed1979

Photochemical reactions on the synthetic polymers containing thymine bases.

Photodimerizations of N-2-isobutyloxyethyl thymine (T-M), bis[2-(5-methyl-1-pyrimidinyl)ethyl]glutarate (T-T), poly-N-2-methacryloyloxethyl thymine (P-MAOT) and poly-N-2-acryloyloxyethyl thymine (P-AOT) were studied in dimethylformamide solution. Quantum efficiencies of intramolecular photodimerizations were determined to be 0.0012 for T-T, 0.0084 for P-MAOT and 0.010 for P-AOT. In the case of T-M, however, intermolecular photodimerization did not occur under the reaction condition used. Quenching studies by using isoprene suggest that the photodimerization of T-T occurs predominantly through an excited triplet state, while that of P-MAOT and P-AOT occur through both singlet and triplet states. For the effect of adding model compounds containing adenine bases on this reaction, adenine derivatives acts as an inhibitor against this reaction by quenching the excited singlet state of thymine. The photodimers of T-T, P-MAOT and P-AOT were concluded to be two syn-fused cyclobutane- type dimers (cis-syn and trans-syn).

Photochemistry↗
PubMed1978

Gas chromatographic determination of nalidixic acid in tablets.

A gas chromatographic method has been established for the quantitative analysis of nalidixic acid. The method is based on the derivatization of nalidixic acid with diazomethane, and 5-alpha-cholestane is used as an internal standard. The sample is chromatographed on a glass column packed with 1% OV-1 on Chromosorb W. Quantitation is achieved by measuring peak-height ratios. The improved simplicity, specificity and accuracy of the method has been demonstrated for the quantitation of nalidixic acid in tablets.

Chromatography, Gas↗
PubMed1978

Statistical moments in pharmacokinetics.

Statistical moments are parameters that describe the characteristics of the time courses of plasma concentration (area, mean residence time, and variance of residence time) and of the urinary excretion rate that follow administration of a single dose of a drug. The relationship between the moments of a time-course curve and pharmacokinetic profiles of drug disposition, i.e., absorption, distribution, metabolism, and excretion, is described. The moments are related to the extent and rate of bioavailability, and it is shown that they can be effectively applied to the deconvolution operation.

Biological Availability↗