Epiandrosterone sulfate prolongs the detectability of testosterone, 4‐androstenedione, and dihydrotestosterone misuse by means of carbon isotope ratio mass spectrometry
Bibliographic record
Abstract
In the course of investigations into the metabolism of testosterone (T) by means of deuterated T and hydrogen isotope ratio mass spectrometry, a pronounced influence of the oral administration of T on sulfoconjugated steroid metabolites was observed. Especially in case of epiandrosterone sulfate (EPIA_S), the contribution of exogenous T to the urinary metabolite was traceable up to 8 days after a single oral dose of 40 mg of T. These findings initiated follow-up studies on the capability of EPIA_S to extend the detection of T and T analogue misuse by carbon isotope ratio (CIR) mass spectrometry in sports drug testing. Excretion study urine samples obtained after transdermal application of T and after oral administration of 4-androstenedione, dihydrotestosterone, and EPIA were investigated regarding urinary concentrations and CIR. With each administered steroid, EPIA_S was significantly depleted and prolonged the detectability when compared to routinely used steroidal target compounds by a factor of 2 to 5. In order to simplify the sample preparation procedure for sulfoconjugated compounds, enzymatic cleavage by Pseudomonas aeruginosa arylsulfatase was tested and implemented into CIR measurements for the first time. Further simplification was achieved by employing multidimensional gas chromatography to ensure the required peak purity for CIR determinations, instead of sample purification strategies using liquid chromatographic fractionation. Taking into account these results that demonstrate the unique and broad applicability of EPIA_S for the detection of illicit administrations of T or T-related steroids, careful consideration of how this steroid can be implemented into routine doping control analysis appears warranted. Copyright © 2017 John Wiley & Sons, Ltd.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".