Sonja Seefried

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S-Carboxymethyl-L-cysteine (CMC) is used both as an orally administered mucolytic agent and as a probe drug for uncovering polymorphic sulfoxidation of other sulfur-containing drugs in humans. However, several recent studies could not confirm the formation of significant amounts of urinary sulfoxides of CMC or its decarboxylation product(More)
Thromboxane A2, the predominant product of arachidonic acid metabolism in the blood platelet, is a potent vasoconstrictor and platelet agonist. During its biosynthesis from cyclic endoperoxide, 12(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (HHT) is formed in equal amounts. The further metabolism of HHT, catalyzed by 15-hydroxyprostaglandin dehydrogenase,(More)
Enzyme deficiencies in pyrimidine metabolism are associated with a risk for severe toxicity against the antineoplastic agent 5-fluorouracil. To assess whether urinary levels of pyrimidines and their metabolites can be used for predicting patients' individual phenotype, a new gas chromatographic-tandem mass spectrometric method was developed which allows the(More)
A sensitive and specific method was developed for the determination of codeine and morphine in human serum and for the determination of trace amounts of endogenous morphine in human urine. The analytes were recovered from serum by a simple liquid-liquid extraction method. Urine samples were hydrolyzed, and purified by two liquid-liquid extraction steps and(More)
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