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Record W2112425784 · doi:10.1136/bjsm.2006.028027

Significance of 19-norandrosterone in athletes’ urine samples

2006· review· en· W2112425784 on OpenAlexaff
Christiane Ayotte

Bibliographic record

VenueBritish Journal of Sports Medicine · 2006
Typereview
Languageen
FieldMedicine
TopicHormonal and reproductive studies
Canadian institutionsArmand Frappier MuseumInstitut National de la Recherche Scientifique
Fundersnot available
KeywordsUrineMetaboliteExcretionNandroloneNorethisteronePhysiologyAnabolismMedicineUrinary systemEndocrinologyInternal medicineChemistryPopulation

Abstract

fetched live from OpenAlex

Nandrolone and other 19-norsteroid potent anabolic steroids have been prohibited in sports for 30 years. The detection of the main urinary metabolite--19-norandrosterone--in amounts greater than 2 ng/ml constitutes an adverse analytical finding. The presence in nutritional sport supplements of steroids not listed on the label has undoubtedly resulted in positive tests, but inadvertent consumption of meat containing residues of hormonal treatment should not realistically cause apprehension. Although highly improbable, athletes should prudently avoid meals composed of pig offal in the hours preceding the test since the consumption of edible parts of a non-castrated pig, containing 19-nortestosterone, has been shown to results in the excretion of 19-norandrosterone in the following hours. Norsteroid metabolites are formed during pregnancy and excreted as minor metabolites of norethisterone, and minute amounts have been identified in some male and female samples when using more sensitive techniques of detection. Whereas exercise does not seem to be a significant factor in 19-norandrosterone excretion, some rare urine samples were found to be a suitable medium for in situ 19-demethylation of urinary metabolites.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

How this classification was reachedexpand

Full frame machine prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.001
metaresearch head score (Gemma)0.001
Version: metacan-v3-hybrid-931329e0061cValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Not applicable · Consensus signal: none
GenreCandidate signal: Review · Consensus signal: Review
Teacher disagreement score0.003
Threshold uncertainty score0.008

Distilled classifier scores by category (both heads)

CategoryCodexGemma
Metaresearch0.0010.001
Meta-epidemiology (narrow)0.0010.000
Meta-epidemiology (broad)0.0020.000
Bibliometrics0.0030.003
Science and technology studies0.0000.000
Scholarly communication0.0010.001
Open science0.0010.000
Research integrity0.0010.001
Insufficient payload (model declined to judge)0.0020.002

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.

Opus teacher head0.047
GPT teacher head0.320
Teacher spread0.273 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Classification

machine, unvalidated

Machine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.

The models applied no category: nothing in the taxonomy fit this work.
Study designNot applicable
Domainnot available
GenreReview

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".

Quick stats

Citations43
Published2006
Admission routes1
Has abstractyes

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