Characterisation of Leydig cell dysfunction in previous illicit androgen users.

Background And Objectives: A few studies have explored the impairment of pituitary gonadotroph and Leydig cell function in men who recently ceased illicit androgen use, as assessed by stimulation tests. However, the capacity of the pituitary-testis axis in previous users who discontinued androgen use years ago remains unclear. This study evaluated the pituitary-testis-axis capacity in previous illicit androgen users and nonusers.

Effect of oral fluid in urine samples on the analysis of selected erythropoietin receptor agonists and detection of saliva-specific markers for doping control purposes.

Due to their performance-enhancing effect, erythropoiesis-stimulating agents (ESAs) are banned at all times by the World Anti-Doping Agency (WADA) in competitive sports. Doping control analyses for such compounds are routinely performed using gel electrophoretic and immunoblotting techniques, and degradation of the analytes can severely impair detection, results evaluation and interpretation. As oral fluid (OF) contains significant amounts of proteases, the question of whether its addition to a doping control urine sample may impede anti-doping analysis needs to be addressed.

Bioanalytical methods in doping controls: a review.

The analytical and technological approaches employed in doping analysis are constantly reviewed and updated to allow for keeping pace with progresses in pharmaceutical and medicinal research and the therein inherent options of misuse as performance enhancing drugs or methods. Enormous changes, improvements, and developments have been achieved in recent years, particularly, but not exclusively, in the bioanalytical sector. Several of these new strategies are examined systematically in this review using examples from the World Anti-Doping Agency (WADA) list of banned substances and methods.

Cost Minimized Immunoaffinity Purification of EPO and Its Analogs in Doping Control-A Step-by-Step Protocol for Human Urine and Blood.

A cost minimized immunoaffinity protocol was developed, which allows the direct purification of ERAs (urinary and recombinant human EPO, Darbepoetin, EPO-Fc, CERA) from human urine. The method applies magnetic beads and needs no covalent immobilization of the capture antibody. It requires only 10 mL of urine, 1 μg of anti-EPO antibody, and 25 μL of bead slurry.

Annual Banned-Substance Review 17th Edition-Analytical Approaches in Human Sports Drug Testing 2023/2024.

The 17th edition of the annual banned-substance review on analytical approaches in human sports drug testing is dedicated to literature published between October 2023 and September 2024. As in previous years, focus is put particularly on new or enhanced analytical options in human doping controls as well as investigations into the metabolism and elimination of compounds of interest, which represent central (while not exclusive) cornerstones of the global anti-doping mission. New information published within the past 12 months on established doping agents as well as new potentially relevant substances are reviewed and discussed in the context of the World Anti-Doping Agency's 2024 Prohibited List.

Coronary Microvascular Dysfunction Years After Cessation of Anabolic Androgenic Steroid Use.

Importance: Long-term use of anabolic androgenic steroids (AASs) is associated with a high risk of left ventricular hypertrophy, heart failure with reduced systolic function, and early sudden death, with the mechanism of progression being understudied. Early and persistent impaired myocardial microcirculation could be of clinical importance and a potential underlying mechanism of frequent and early cardiac disease among individuals with AAS use and a future potential target for intervention.

Objective: To investigate coronary microcirculation by measuring myocardial flow reserve (MFR) in men with current and former AAS use compared with controls with no prior AAS use, using cardiac rubidium 82 (82Rb) positron emission tomography/computed tomography (PET/CT).

Effect of exercise on plasma insulin levels in individuals with type 1 diabetes: A systematic review and meta-analysis.

Aims: Current evidence of the impact of acute exercise on insulin levels in individuals with type 1 diabetes remains controversial. Therefore, we conducted a systematic review and meta-analysis to explore exercise-induced changes in insulin levels.

Materials And Methods: We conducted a systematic review (until 05 November 2023) and meta-analysis exploring the effect of exercise on insulin concentration in individuals with type 1 diabetes.

Long-Term Excretion of Roxadustat in Urine.

Roxadustat (FG-4592), an orally active hypoxia-inducible factor prolyl hydroxylase stabilizer, has been shown to enhance erythropoiesis by increasing endogenous erythropoietin. It is indicated for the treatment of anemia and chronic kidney disease and is approved for clinical use in several countries, including the European Union, Japan and others. Due to its reasonably anticipated performance-enhancing effect in athletes, roxadustat is prohibited for use in sports at all times.

Improving the Determination of Carbon Isotope Ratios of Endogenous Steroids Found in Human Serum.

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 enables the detection of the misuse of low-dose T administrations especially in female athletes, whereas urinary markers of the steroid profile may not be influenced significantly. In contrast to the urinary steroid profile, knowledge on confounding factors regarding serum concentrations of T and A4 is yet comparably scarce, and corroborating exogenous sources of the target analytes by isotope ratio mass spectrometry (IRMS) is desirable.

Investigations into the Concentrations and Metabolite Profiles of Doping Agents and Antidepressants in Human Seminal Fluid Using Liquid Chromatography-Mass Spectrometry.

Exogenous substances, including drugs and chemicals, can transfer into human seminal fluid and influence male fertility and reproduction. In addition, substances relevant in the context of sports drug testing programs, can be transferred into the urine of a female athlete (after unprotected sexual intercourse) and trigger a so-called adverse analytical finding. Here, the question arises as to whether it is possible to distinguish analytically between intentional doping offenses and unintentional contamination of urine by seminal fluid.

Identification of human metabolites of fast skeletal troponin activators Tirasemtiv and Reldesemtiv for doping control purposes.

The fast skeletal troponin activators (FSTAs) Reldesemtiv and Tirasemtiv were developed for patients suffering from neuro-degenerative diseases of the motor nervous system, e.g. amyotrophic lateral sclerosis (ALS).

A comprehensive gas chromatography electron ionization high resolution mass spectrometry study of a new steroidal selective androgen receptor modulator (SARM) compound S42.

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. Fundamental understanding of the behavior of S42 (1) and of relevant derivatives in gas chromatography-electron ionization MS experiments at high resolution (GC-EI-HRMS) is indispensable to develop a reliable qualitative and quantitative doping control method for S42 (1) and its metabolites in body fluid matrices. We present important fundamental mechanistic data on the EI fragmentation behavior of S42 (1) and of silyl ether derivatives as well as of stable isotope-labelled reference material.

Longitudinal evaluation of laboratory results and method precision in worldwide erythropoietin external quality assessments.

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 laboratories. The aim of this work was to evaluate participant performance and methodological aspects. In each of the eleven EQA surveys, a blinded sample set of lyophilized human serum containing one sample with lower EPO concentrations (L) and one with higher EPO concentrations (H) was sent to the participating laboratories.

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).

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 athletes. As frequent blood hormone status determinations using venipuncture are rare in sports practice, microsampling offers promising possibilities for preventing and assessing RED-S. Therefore, this study aimed at developing a liquid chromatography-high-resolution tandem mass spectrometry (LC-HRMS/MS) method for quantifying relevant steroids and thyroid hormones in 30 μL of capillary blood obtained using Mitra devices with volumetric absorptive microsampling technology (VAMS).

Acute exercise activates the AHR in peripheral blood mononuclear cells in an intensity-dependent manner.

The kynurenine pathway (KP) of tryptophan degradation generates several metabolites such as kynurenine (KYN) or kynurenic acid (KA) that serve as endogenous ligands of the aryl hydrocarbon receptor (AHR). Due to its distinct biological roles particularly modulating the immune system, the AHR is a current therapeutic target across different inflammation-related diseases. Here, we show an acute exercise-induced increase in AHR ligand availability on a systemic level and a kynurenine pathway activation in peripheral blood mononuclear cells (PBMCs).

Complementary information concerning the suspected interindividual transmission of GW1516, a substance prohibited in sport, through intimate contact: a case report.

Purpose: Inadvertent and/or unknowing exposure to drugs and drug residues has been frequently debated in situations of so-called adverse analytical finding (AAF) in the context of sports drug testing programs. Transfer of drug residues via unprotected intercourse is a conceivable scenario but scientific data and authentic case reports are scarce. Herein, investigations into two AAFs with the peroxisome proliferator-activated receptor delta (PPARδ) agonist GW1516 are reported and discussed.

Detection of sgRNA via SHERLOCK as Potential CRISPR Related Gene Doping Control Strategy.

Apprehensions about gene doping have grown consistently due to advancements in gene engineering techniques, particularly with the emergence of clustered regularly interspaced short palindromic repeats/CRISPR-associated (CRISPR/Cas)-based tools. These tools not only provide unprecedented possibilities for illicit performance enhancement by athletes but also offer new avenues for the detection of gene doping through biosensing of nucleic acids. Hence, pursuing on a previous study, an analytical method based on reverse transcriptase-recombinase polymerase amplification (RT-RPA) and subsequent qualitative nucleic acid detection by means of Specific High Sensitive Enzymatic Reporter UnLOCKing (SHERLOCK) was optimized for the direct detection of sgRNA associated with in serum.

Establishing Personalized Blood Protein Reference Ranges Using Noninvasive Microsampling and Targeted Proteomics: Implications for Antidoping Strategies.

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 doping substance or the method itself. In the context of this program, a highly multiplexed mass spectrometry-based proteomics assay for 319 peptides corresponding to 250 proteins was developed, including proteins associated with blood-doping practices. "Baseline" expression profiles of these potential biomarkers in capillary blood (dried blood spots (DBS)) were established using multiple reaction monitoring (MRM).