Baume N.,University of Geneva |
Geyer H.,German Sport University Cologne |
Vouillamoz M.,European Union |
Grisdale R.,European Union |
And 14 more authors.
Drug Testing and Analysis | Year: 2016
Testosterone and related compounds are the most recurrent doping substances. The steroid profile, consisting of the quantification of testosterone and its metabolites, has been described as the most significant biomarker to detect doping with pseudo-endogenous anabolic steroids. The steroidal module of the Athlete Biological Passport (ABP) was launched by the World Anti-Doping Agency (WADA) in 2014. To assess the value of introducing the module to its anti-doping programme, the Union of European Football Associations (UEFA) decided to analyze retrospectively the steroid profile data of 4195 urine samples, collected from 879 male football players and analyzed in 12 WADA-accredited laboratories between 2008 and mid-2013. This study focused on the evaluation of T/E ratios. The coefficient of variation (CV) and the adaptive model were the two statistical models used to study the longitudinal follow-up. A CV of 46% was determined to be the maximal natural intra-individual variation of the T/E when the sequence consisted of single data points analyzed in different laboratories. The adaptive model showed some profiles with an atypical T/E sequence and also enabled an estimate of the prevalence of external factors impacting the T/E sequences. Despite the limitations of this retrospective study, it clearly showed that the longitudinal and individual follow-up of the T/E biomarker of the players is a good tool for target testing in football. UEFA has therefore decided to implement the steroidal module of the ABP from the start of the next European football season in September 2015. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd. Source
Kiss A.,CNRS Institute of Analytical Sciences |
Lucio M.,Helmholtz Center for Environmental Research |
Fildier A.,CNRS Institute of Analytical Sciences |
Buisson C.,Agence Francaise de Lutte contre le Dopage AFLD |
And 3 more authors.
PLoS ONE | Year: 2013
We have detected differences in metabolite levels between doped athletes, clean athletes, and volunteers (non athletes). This outcome is obtained by comparing results of measurements from two analytical platforms: UHPLC-QTOF/MS and FT-ICR/MS. Twenty-seven urine samples tested positive for glucocorticoids or beta-2-agonists and twenty samples coming from volunteers and clean athletes were analyzed with the two different mass spectrometry approaches using both positive and negative electrospray ionization modes. Urine is a highly complex matrix containing thousands of metabolites having different chemical properties and a high dynamic range. We used multivariate analysis techniques to unravel this huge data set. Thus, the several groups we created were studied by Principal Components Analysis (PCA) and Partial Least Square regression (PLS-DA and OPLS) in the search of discriminating m/z values. The selected variables were annotated and placed on pathway by using MassTRIX. © 2013 Kiss et al. Source
Leuenberger N.,University of Geneva |
Reichel C.,Doping Control Laboratory |
Lasne F.,Agence Francaise de Lutte contre le Dopage AFLD
Bioanalysis | Year: 2012
Stimulation of erythropoiesis is one of the most efficient ways of doping. This type of doping is advantageous for aerobic physical exercise and of particular interest to endurance athletes. Erythropoiesis, which takes place in bone marrow, is under the control of EPO, a hormone secreted primarily by the kidneys when the arterial oxygen tension decreases. In certain pathological disorders, such as chronic renal failure, the production of EPO is insufficient and results in anemia. The pharmaceutical industry has, thus, been very interested in developing drugs that stimulate erythropoiesis. With this aim, various strategies have been, and continue to be, envisaged, giving rise to an expanding range of drugs that are good candidates for doping. Anti-doping control has had to deal with this situation by developing appropriate methods for their detection. This article presents an overview of both the drugs and the corresponding methods of detection, and thus follows a roughly chronological order. © 2012 Future Science Ltd. Source
Thevis M.,German Sport University Cologne |
Thevis M.,European Monitoring Center for Emerging Doping Agents |
Geyer H.,German Sport University Cologne |
Thomas A.,German Sport University Cologne |
And 8 more authors.
Journal of Pharmaceutical and Biomedical Analysis | Year: 2015
Chlorazanil (Ordipan, N-(4-chlorophenyl)-1,3,5-triazine-2,4-diamine) is a diuretic agent and as such prohibited in sport according to the regulations of the World Anti-Doping Agency (WADA). Despite its introduction into clinical practice in the late 1950s, the worldwide very first two adverse analytical findings were registered only in 2014, being motive for an in-depth investigation of these cases. Both individuals denied the intake of the drug; however, the athletes did declare the use of the antimalarial prophylactic agent proguanil due to temporary residences in African countries.A structural similarity between chlorazanil and proguanil is given but no direct metabolic relation has been reported in the scientific literature. Moreover, chlorazanil has not been confirmed as a drug impurity of proguanil. Proguanil however is metabolized in humans to N-(4-chlorophenyl)-biguanide, which represents a chemical precursor in the synthesis of chlorazanil. In the presence of formic acid, formaldehyde, or formic acid esters, N-(4-chlorophenyl)-biguanide converts to chlorazanil.In order to probe for potential sources of the chlorazanil detected in the doping control samples, drug formulations containing proguanil and urine samples of individuals using proguanil as antimalarial drug were subjected to liquid chromatography-high resolution/high accuracy mass spectrometry. In addition, in vitro simulations with 4-chlorophenyl-biguanide and respective reactants were conducted in urine and resulting specimens analyzed for the presence of chlorazanil.While no chlorazanil was found in drug formulations, the urine samples of 2 out of 4 proguanil users returned findings for chlorazanil at low ng/mL levels, similar to the adverse analytical findings in the doping control samples. Further, in the presence of formaldehyde, formic acid and related esters, 4-chlorophenyl-biguanide was found to produce chlorazanil in human urine, suggesting that the detection of the obsolete diuretic agent was indeed the result of artefact formation and not of the illicit use of a prohibited substance. © 2015 Elsevier B.V. Source
Couve S.,Laboratoire Of Genetique Oncologique Of Lecole Pratique Des Hautes Etudes Ephe |
Couve S.,French Institute of Health and Medical Research |
Couve S.,Center Expert National Cancers Rares a |
Ladroue C.,Laboratoire Of Genetique Oncologique Of Lecole Pratique Des Hautes Etudes Ephe |
And 37 more authors.
Cancer Research | Year: 2014
The classic model of tumor suppression implies that malignant transformation requires full "two-hit" inactivation of a tumor-suppressor gene. However, more recent work in mice has led to the proposal of a "continuum" model that involves more fluid concepts such as gene dosage-sensitivity and tissue specificity. Mutations in the tumor-suppressor gene von Hippel-Lindau (VHL) are associated with a complex spectrum of conditions. Homozygotes or compound heterozygotes for the R200W germline mutation in VHL have Chuvash polycythemia, whereas heterozygous carriers are free of disease. Individuals with classic, heterozygous VHL mutations have VHL disease and are at high risk of multiple tumors (e.g., CNS hemangioblastomas, pheochromocytoma, and renal cell carcinoma). We report here an atypical family bearing two VHL gene mutations in cis (R200W and R161Q), together with phenotypic analysis, structural modeling, functional, and transcriptomic studies of these mutants in comparison with classical mutants involved in the different VHL phenotypes. We demonstrate that the complex pattern of disease manifestations observed in VHL syndrome is perfectly correlated with a gradient of VHL protein (pVHL) dysfunction in hypoxia signaling pathways. Thus, by studying naturally occurring familial mutations, our work validates in humans the "continuum" model of tumor suppression. © 2014 AACR. Source