Publications by authors named "W Van Thuyne"

Until the end of 2003 a urinary concentration of pseudoephedrine exceeding 25 microg/mL was regarded as a doping violation by the World Anti-Doping Agency. Since its removal from the prohibited list in 2004 the number of urine samples in which pseudoephedrine was detected in our laboratory increased substantially. Analysis of 116 in-competition samples containing pseudoephedrine in 2007 and 2008, revealed that 66% of these samples had a concentration of pseudoephedrine above 25 microg/mL.

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The misuse of the anabolic steroid methyltestosterone is currently routinely monitored in doping control laboratories by gas chromatography-mass spectrometry (GC-MS) of two of its metabolites: 17alpha-methyl-5beta-androstane-3alpha,17beta-diol and 17alpha-methyl-5alpha-androstane-3alpha,17beta-diol. Because of the absence of any easy ionizable moiety, these metabolites are poorly detectable using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI). In this study, the metabolism of methyltestosterone has been reinvestigated by the use of a precursor ion scan method in LC-ESI-MS/MS.

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Endogenous steroids are amongst the most misused doping agents in sports. Their presence poses a major challenge for doping control laboratories. Current threshold levels do not allow for the detection of all endogenous steroid misuse due to great interindividual variations in urinary steroid concentrations.

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A comprehensive screening method for the detection of prohibited substances in doping control is described and validated. This method is capable of detecting over 150 components mentioned on the list of the World Anti-Doping Agency including anabolic androgenic steroids, stimulants and all narcotic agents that are currently analysed using different analytical methods. The analytes are extracted from urine by a combined extraction procedure using freshly distilled diethyl ether and tert-butyl methyl ether as extraction solvents at pH 9.

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Objective: To assess and compare the prevalence of declared medication, such as corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), beta2-agonists, narcotic analgesics, anaesthetics, and antidepressant drugs, in time and between different sports among athletes tested for doping control in a 4-year period.

Design: Survey study.

Setting: Belgium.

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