Dieter Kaiser

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The time course of ventilatory adaptation to medroxyprogesterone acetate (MPA) and potential mediators of this response in plasma and lumbar CSF were determined in five healthy adult males. A significant decrease in arterial PCO2 (PACO2) at rest and exercise was noted within 48 h of drug administration with the maximum effect reached within 7 days and(More)
The metabolic chiral inversion of R-(-)-ibuprofen has been studied in human subjects by means of specific deuterium labeling and stereoselective gas chromatography-mass spectrometry methodology. After simultaneous p.o. administration of a mixture of R-(-)-ibuprofen (300 mg) and R-(-)-[3,3,3-2H3]ibuprofen (304 mg) to four adult male volunteers, the(More)
Following administration of a single oral dose (400 mg) or RS-ibuprofen (RS-IBP) to humans, a novel metabolite was isolated from urine and identified by tandem mass spectrometry as the taurine conjugate of IBP (IBP-Tau). The corresponding glycine conjugate was sought but was not detected in these studies. Quantitative analyses indicated that taurine(More)
Seven normal patients in labor at term were given 125 mg of methylprednisolone hemisuccinate intravenously shortly before delivery. Analysis of maternal and cord plasma samples indicated that both the hemisuccinate and free alcohol forms of the corticosteroid were transported in pharmacologic levels to the fetal compartment. Since methylprednisolone may(More)
We investigated the mechanism by which exposure to cold sensitizes rats to the formation of gastric lesions after a low dose of aspirin (50 mg/kg). Six times more lesions were produced by aspirin plus cold than by aspirin alone. Three hypotheses were studied to explain the synergism of aspirin plus cold on lesion formation: gastric acid hypersecretion,(More)
Enantiomeric compositions of the major urinary metabolites of ibuprofen [(RS)-2-(4-isobutylphenyl)propionic acid]were characterized after oral administration of the racemic mixture and oral administration of the individual enantiomers to normal human volunteers. Resolution of the diastereomeric amides, formed by reaction of the urinary metabolites with(More)
Deuterium labeling techniques and stereoselective GC/MS methodology have been employed to investigate the mechanism by which R-ibuprofen undergoes metabolic chiral inversion in the rat in vivo. Following oral administration of a mixture of R-ibuprofen (7.5 mg kg-1) and R-[ring-2H4; 2-2H]ibuprofen (R-[2H5]ibuprofen) (7.5 mg kg-1) to male Sprague-Dawley rats,(More)
To study the behavior of the d- and l-isomers of ibuprofen in humans, a method for the determination of the individual enantiomers in plasma and urine was required. A specific procedure was developed based on (a) benzene extraction of the acidified specimens, (b) TLC of the benzene extract residue, (c) formation of the l-alpha-methylbenzylamides of the(More)