Mario Thevis
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View article: Investigations Into the Human Metabolism of Trestolone (7α‐Methyl‐19‐Nortestosterone)
Investigations Into the Human Metabolism of Trestolone (7α‐Methyl‐19‐Nortestosterone) Open
Already in the 1960s, the anabolic properties of Trestolone (7α‐methyl‐19‐nortestosterone, MENT) were investigated in the context of cancer research, and MENT was found to be 10 times more potent regarding its anabolic properties compared …
View article: Further Insights Into the Metabolism of LGD‐4033 in Human Urine. Part 1. Structure Elucidation of Additional Important Metabolites
Further Insights Into the Metabolism of LGD‐4033 in Human Urine. Part 1. Structure Elucidation of Additional Important Metabolites Open
This study presents LC‐HRMS/MS analyses of LGD‐4033 post‐administration urine samples, following hydrolysis with β ‐glucuronidase and liquid–liquid extraction, against chemically synthesized molecules that matched previously proposed metab…
View article: Assessing the Effect of Probiotics in the Steroidal Module of the Athlete's Biological Passport
Assessing the Effect of Probiotics in the Steroidal Module of the Athlete's Biological Passport Open
Athletes are increasingly using probiotic supplementation to support their overall health, and it can be particularly beneficial for female athletes in managing recurrent urinary tract infections and bacterial vaginosis. One route of probi…
View article: Further Insights Into the Metabolism of LGD‐4033 in Human Urine. Part 2. A New Minor Metabolite With Antagonistic Activity on the Androgen Receptor Can Indicate Recent Substance Intake
Further Insights Into the Metabolism of LGD‐4033 in Human Urine. Part 2. A New Minor Metabolite With Antagonistic Activity on the Androgen Receptor Can Indicate Recent Substance Intake Open
Using a targeted metabolic investigation approach, a new, previously undescribed metabolite, which is a pyrrole derivative of LGD‐4033, has been detected and coded as M8 . This metabolite can be detected in postadministration human urine s…
View article: The influence of the route of drug administration on the metabolic profile of trenbolone in doping control urine samples
The influence of the route of drug administration on the metabolic profile of trenbolone in doping control urine samples Open
Advances in analytical techniques have markedly improved the detection of anabolic-androgenic steroids (AAS) in doping controls. This represents a major success for anti-doping efforts, but at the same times raises concerns about inadverte…
View article: When is a sample a urine sample? Markers for urine sample authenticity assessment in sports drug testing
When is a sample a urine sample? Markers for urine sample authenticity assessment in sports drug testing Open
Human routine doping controls rely to a considerable extent on urine samples, and test methods have been optimized for decades to allow for comprehensive analyses with adequate analytical sensitivities. However, attempts of sample manipula…
View article: Simplified Analysis of Native Steroid Esters in Dried Blood Spots by LC–MS <sup>3</sup>
Simplified Analysis of Native Steroid Esters in Dried Blood Spots by LC–MS <sup>3</sup> Open
Steroidal esters (e.g., testosterone, nandrolone and boldenone esters) belong to the substance class prohibited in professional sport that is particularly frequently abused due to its considerable performance‐enhancing effects. Thus, a hig…
View article: Proof-of-concept of a prior validated LC-MS/MS method for detection of N-lactoyl-phenylalanine in dried blood spots before, during and after a performance diagnostic test of junior squad triathletes
Proof-of-concept of a prior validated LC-MS/MS method for detection of N-lactoyl-phenylalanine in dried blood spots before, during and after a performance diagnostic test of junior squad triathletes Open
Introduction N -lactoyl-phenylalanine (lac-phe) is an exercise-inducible metabolite that is discussed for suppressing appetite. As no point-of-care lac-phe analysis for frequent sample collection during exercise exists, the objectives of t…
View article: In Vitro Metabolism of Doping Agents (Stanozolol, LGD-4033, Anastrozole, GW1516, Trimetazidine) by Human Seminal Vesicle and Liver Fractions
In Vitro Metabolism of Doping Agents (Stanozolol, LGD-4033, Anastrozole, GW1516, Trimetazidine) by Human Seminal Vesicle and Liver Fractions Open
Background: In order to address complex scenarios in anti-doping science, especially in cases where an unintentional exposure of athletes to prohibited substances and a corresponding contamination of doping control samples at the collectio…
View article: Phosphatidylethanol in post‐mortem blood: A comparative study of blood matrices and its stability at routine storage conditions
Phosphatidylethanol in post‐mortem blood: A comparative study of blood matrices and its stability at routine storage conditions Open
Determination of alcohol markers in post‐mortem cases can be useful to classify drinking habits and potential alcohol habituation prior to death. Phosphatidylethanol (PEth) is a direct alcohol marker and is already commonly used in a varie…
View article: Multiplex detection of seven transgenes for human gene doping analysis
Multiplex detection of seven transgenes for human gene doping analysis Open
Gene doping is known as the manipulation of congenital traits by gene therapeutic approaches with the intent of illicit athletic performance enhancement. A panel prototype suitable for multiplex gene doping detection by combining multiplex…
View article: Combined detection of inhibitors of the activin receptor signaling pathways (IASPs) by means of LC-HRMS/MS for human doping control
Combined detection of inhibitors of the activin receptor signaling pathways (IASPs) by means of LC-HRMS/MS for human doping control Open
Members of the transforming growth factor beta superfamily such as myostatin, activin A, and GDF-11, are dimeric cytokines signaling through activin receptors. They play important regulative roles in different biological processes as the f…
View article: Assessment and cross-validation of calibration transferability between dried blood spot sampling devices for accurate quantification of phosphatidylethanol
Assessment and cross-validation of calibration transferability between dried blood spot sampling devices for accurate quantification of phosphatidylethanol Open
Phosphatidylethanol (PEth) is a direct alcohol biomarker which is used in a variety of clinical and forensic contexts. Due to its limited stability in whole blood, PEth is routinely analysed using dried blood spots (DBS). There are many di…
View article: Gel Electrophoretic Detection of Black Market ACE‐031
Gel Electrophoretic Detection of Black Market ACE‐031 Open
The usage of ACE‐031 (Ramatercept), a dimeric fusion protein consisting of a human activin receptor IIB (ACVR2B) fragment linked to an Fc‐part of human IgG1, is banned according to chapter S4.3 of the “WADA 2024 List of Prohibited Substanc…
View article: Investigations Into the Urinary Metabolite Elimination Profile of the Selective Androgen Receptor Modulator S‐23 in Studies Mimicking Contaminated Product Ingestion for Doping Control Purposes
Investigations Into the Urinary Metabolite Elimination Profile of the Selective Androgen Receptor Modulator S‐23 in Studies Mimicking Contaminated Product Ingestion for Doping Control Purposes Open
Selective androgen receptor modulators (SARMs) have repeatedly been reason of adverse analytical findings (AAFs) in routine doping controls. Among these, S‐23 has been identified in five AAFs reported in 2022. In addition to intentional do…
View article: Investigations Into Structures of In Vitro<i>–</i>Derived Phase I Metabolites of a Novel 20‐Keto‐Steroid S42 by GC‐EI HR MS Analysis and Chemical Synthesis
Investigations Into Structures of In Vitro<i>–</i>Derived Phase I Metabolites of a Novel 20‐Keto‐Steroid S42 by GC‐EI HR MS Analysis and Chemical Synthesis Open
S42, 4‐Methyl‐19‐norpregna‐1,3,5(10)‐trien‐20‐one a new 20‐keto‐steroid, is a novel selective androgen receptor modulator (SARM). The World Anti‐Doping Agency (WADA) bans the use of SARMs in sports at all times. In preparation of a sensiti…
View article: Impact of Androgenic Anabolic Steroids on Cardiovascular Health in Men and Women - PART OF THE FITNESS DOPING IN DENMARK (FIDO-DK) STUDY
Impact of Androgenic Anabolic Steroids on Cardiovascular Health in Men and Women - PART OF THE FITNESS DOPING IN DENMARK (FIDO-DK) STUDY Open
Background Illicit use of anabolic androgenic steroids (AAS) is common among recreational athletes, yet comprehensive studies on adverse cardiovascular outcomes, especially in female AAS users, are lacking. Methods A cross-sectional study …
View article: Improving the Determination of Carbon Isotope Ratios of Endogenous Steroids Found in Human Serum
Improving the Determination of Carbon Isotope Ratios of Endogenous Steroids Found in Human Serum Open
The determination of serum concentrations of testosterone (T) and 4‐androstenedione (A4) was implemented into the steroidal module of the Athlete Biological Passport in 2023. Monitoring T, A4, and the ratio of T/A4 in a longitudinal manner…
View article: A comprehensive gas chromatography electron ionization high resolution mass spectrometry study of a new steroidal selective androgen receptor modulator (SARM) compound S42
A comprehensive gas chromatography electron ionization high resolution mass spectrometry study of a new steroidal selective androgen receptor modulator (SARM) compound S42 Open
The synthetic 20‐keto‐steroid S42 ( 1 ) demonstrated selective androgen receptor modulator (SARM) properties in preclinical studies and, consequently, received growing attention also in the context of sports drug testing programs. Fundamen…
View article: Experiences and challenges for EQA providers in assessing the commutability of control materials in accuracy-based EQA programs
Experiences and challenges for EQA providers in assessing the commutability of control materials in accuracy-based EQA programs Open
Experiences and challenges for EQA providers in assessing the commutability of control materials in accuracy-based EQA programs
View article: Acute exercise activates the AHR in peripheral blood mononuclear cells in an intensity-dependent manner
Acute exercise activates the AHR in peripheral blood mononuclear cells in an intensity-dependent manner Open
The findings of this study show that acute endurance exercise activates a receptor that has been described to integrate metabolic signals into the immune system. We uncover a potential mechanistic link on how exercise modulates the immune …
View article: Longitudinal evaluation of laboratory results and method precision in worldwide erythropoietin external quality assessments
Longitudinal evaluation of laboratory results and method precision in worldwide erythropoietin external quality assessments Open
Introduction: This study presents a longitudinal analysis of external quality assessment (EQA) results for erythropoietin (EPO) determinations conducted between 2017 and 2022 with a continuously increasing number of participating laborator…
View article: Development of an LC-HRMS/MS Method for Quantifying Steroids and Thyroid Hormones in Capillary Blood: A Potential Tool for Assessing Relative Energy Deficiency in Sport (RED-S)
Development of an LC-HRMS/MS Method for Quantifying Steroids and Thyroid Hormones in Capillary Blood: A Potential Tool for Assessing Relative Energy Deficiency in Sport (RED-S) Open
Relative energy deficiency in sport (RED-S) is a condition that arises from persistent low energy availability (LEA), which affects the hypothalamic–pituitary axis and results in alterations of several hormones in both male and female athl…
View article: Chiral analysis of ostarine in commercially available products and doping control urine samples
Chiral analysis of ostarine in commercially available products and doping control urine samples Open
Various substances classified as prohibited in sport by the World Anti-Doping Agency (WADA) comprise one or more chiral centers. One such substance is enobosarm ((2S)-3-(4-cyanophenoxy)-N-[4-cyano-3-(trifluoromethyl)phenyl]-2‑hydroxy-2-met…
View article: Establishing Personalized Blood Protein Reference Ranges Using Noninvasive Microsampling and Targeted Proteomics: Implications for Antidoping Strategies
Establishing Personalized Blood Protein Reference Ranges Using Noninvasive Microsampling and Targeted Proteomics: Implications for Antidoping Strategies Open
To prevent doping practices in sports, the World Anti-Doping Agency implemented the Athlete Biological Passport (ABP) program, monitoring biological variables over time to indirectly reveal the effects of doping rather than detect the dopi…
View article: Employing 11-Ketotestosterone as a Target Analyte for Adrenosterone (11OXO) Administration in Doping Controls
Employing 11-Ketotestosterone as a Target Analyte for Adrenosterone (11OXO) Administration in Doping Controls Open
Adrenosterone (Androst-4-ene-3,11,17-trione, 11OXO) is forbidden in sports according to the Prohibited List of the World Anti-Doping Agency. The administration of 11OXO may be detected by monitoring the urinary concentrations of its main h…