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Walter E. Haefeli

Bio: Walter E. Haefeli is an academic researcher from Heidelberg University. The author has contributed to research in topics: Medicine & Pharmacokinetics. The author has an hindex of 64, co-authored 525 publications receiving 15802 citations. Previous affiliations of Walter E. Haefeli include University Hospital Heidelberg & University of Basel.


Papers
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Journal ArticleDOI
TL;DR: No, but not prostacyclin, is essential for flow-mediated dilatation of large human arteries, and this response can be used as a test for the L-arginine/NO pathway in clinical studies.
Abstract: Background Experimental evidence suggests that flow-dependent dilatation of conduit arteries is mediated by nitric oxide (NO) and/or prostacyclin. The present study was designed to assess whether NO or prostacyclin also contributes to flow-dependent dilatation of conduit arteries in humans. Methods and Results Radial artery internal diameter (ID) was measured continuously in 16 healthy volunteers (age, 24±1 years) with a transcutaneous A-mode echo-tracking system coupled to a Doppler device for the measurement of radial blood flow. In 8 subjects, a catheter was inserted into the brachial artery for measurement of arterial pressure and infusion of the NO synthase inhibitor NG-monomethyl-l-arginine (L-NMMA; 8 μmol/min for 7 minutes; infusion rate, 0.8 mL/min). Flow-dependent dilatation was evaluated before and after L-NMMA or aspirin as the response of the radial artery to an acute increase in flow (reactive hyperemia after a 3-minute cuff wrist occlusion). Under control conditions, release of the occlusion...

1,665 citations

Journal ArticleDOI
TL;DR: Serum concentration monitoring showed high concentrations of conjugated alpha-hydroxymidazolam when concentrations of the unconjugated metabolite and the parent drug were below the therapeutic range, and in-vitro binding studies showed that the affinity of binding to the cerebral benzodiazepine receptor of glucuronidated alpha-Hydroxymidine receptor was only about ten times weaker than that of midazolham.

310 citations

Journal ArticleDOI
TL;DR: After 24weeks of treatment with myrcludex B and/or pegylated interferon α-2a, HDV R NA, a relevant marker for hepatitis D infection, decreased in all patients with chronic hepatitis B and D.

301 citations

Journal ArticleDOI
TL;DR: The fact that some of the compounds tested exert Pgp inhibitor effects at similar concentrations as quinidine suggests that pharmacokinetic drug-drug interactions between the newer antidepressants and Pgp substrates should now be thoroughly studied in vivo.
Abstract: Pharmacokinetic drug-drug interactions often occur at the level of P-glycoprotein (Pgp). To study possible interactions caused by the newer antidepressants we investigated citalopram, fluoxetine, fluvoxamine, paroxetine, reboxetine, sertraline, and venlafaxine and their major metabolites desmethylcitalopram, norfluoxetine, paroxetine-metabolite (paroxetine-M), desmethylsertraline, N-desmethylvenlafaxine, and O-desmethylvenlafaxine for their ability to inhibit Pgp. Pgp inhibition was studied by a fluorometric assay using calcein-acetoxymethylester as Pgp substrate and two different cell systems: L-MDR1 cells (model for human Pgp) and primary porcine brain capillary endothelial cells (pBCECs, model for the blood-brain barrier). Both cell systems proved to be suitable for the evaluation of Pgp inhibitory potency of drugs. All antidepressants tested except O-desmethylvenlafaxine showed Pgp inhibitory activity with sertraline, desmethylsertraline, and paroxetine being the most potent, comparable with the well known Pgp inhibitor quinidine. In L-MDR1 cells fluoxetine, norfluoxetine, fluvoxamine, reboxetine, and paroxetine-M revealed intermediate Pgp inhibition and citalopram, desmethylcitalopram, venlafaxine, and N-desmethylvenlafaxine were only weak inhibitors. The ranking order was similar in pBCECs. The fact that some of the compounds tested exert Pgp inhibitor effects at similar concentrations as quinidine suggests that pharmacokinetic drug-drug interactions between the newer antidepressants and Pgp substrates should now be thoroughly studied in vivo.

293 citations

Journal ArticleDOI
TL;DR: The study suggests that basal expression levels of the transporters are directly influenced by PXR expression in liver andPBMCs and demonstrates that PBMCs do not qualify as surrogate tissue for the expression of the four ABC-transporters in small intestine and liver.

261 citations


Cited by
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Book ChapterDOI
01 Jan 2010

5,842 citations

Journal ArticleDOI
TL;DR: In this paper, the authors defined the following terms: ALAT, alanine aminotransferase, ASAT, aspartate AMINOTE, and APAH, associated pulmonary arterial hypertension.
Abstract: ALAT : alanine aminotransferase ASAT : aspartate aminotransferase APAH : associated pulmonary arterial hypertension BAS : balloon atrial septostomy BMPR2 : bone morphogenetic protein receptor 2 BNP : brain natriuretic peptide BPA : balloon pulmonary angioplasty BREATHE : Bosentan

5,224 citations

Journal ArticleDOI
TL;DR: State-of-the-art information is presented and insights are provided into the strengths and limitations of high-resolution ultrasonography of the brachial artery to evaluate vasomotor function, with guidelines for its research application in the study of endothelial physiology.

4,604 citations

Journal ArticleDOI
TL;DR: The Multi-Ethnic Study of Atherosclerosis was initiated in July 2000 to investigate the prevalence, correlates, and progression of subclinical cardiovascular disease (CVD) in a population-based sample of 6,500 men and women aged 45-84 years for identification and characterization of CVD events.
Abstract: The Multi-Ethnic Study of Atherosclerosis was initiated in July 2000 to investigate the prevalence, correlates, and progression of subclinical cardiovascular disease (CVD) in a population-based sample of 6,500 men and women aged 45-84 years. The cohort will be selected from six US field centers. Approximately 38% of the cohort will be White, 28% African-American, 23% Hispanic, and 11% Asian (of Chinese descent). Baseline measurements will include measurement of coronary calcium using computed tomography; measurement of ventricular mass and function using cardiac magnetic resonance imaging; measurement of flow-mediated brachial artery endothelial vasodilation, carotid intimal-medial wall thickness, and distensibility of the carotid arteries using ultrasonography; measurement of peripheral vascular disease using ankle and brachial blood pressures; electrocardiography; and assessments of microalbuminuria, standard CVD risk factors, sociodemographic factors, life habits, and psychosocial factors. Blood samples will be assayed for putative biochemical risk factors and stored for use in nested case-control studies. DNA will be extracted and lymphocytes will be immortalized for genetic studies. Measurement of selected subclinical disease indicators and risk factors will be repeated for the study of progression over 7 years. Participants will be followed through 2008 for identification and characterization of CVD events, including acute myocardial infarction and other coronary heart disease, stroke, peripheral vascular disease, and congestive heart failure; therapeutic interventions for CVD; and mortality.

3,367 citations

Journal ArticleDOI
TL;DR: This Clinical Practice Guideline presents updated recommendations for the optimal management of HBV infection, and future treatment strategies to achieve 'cure' of disease and new biomarkers are discussed.

3,016 citations