Thin-Layer Chromatography Analysis of Human CYP3A-Catalyzed Testosterone 6β-Hydroxylation
Bibliographic record
Abstract
Testosterone and other steroid hormones have been studied as prototypic examples of endogenous substrates for hepatic cytochrome P450 (P450) enzymes. CYP3A enzymes from various species, including human, metabolize testosterone by a 6beta-hydroxylation reaction, which is unique to this P450 subfamily. A thin-layer chromatographic method is described for the determination of 6beta-hydroxytestosterone formed enzymatically by incubation of [14C]-testosterone with cDNA-expressed CYP3A enzymes or liver microsomes. 14C-labeled enzymatic products are applied to silica gel thin-layer plates, which are developed sequentially with methylene chloride:acetone (80:20) followed by chloroform, ethyl acetate, and absolute ethanol (80:20:14). Metabolite quantification is performed by autoradiography and liquid scintillation counting. This method is applicable to enzymatic studies for the determination of CYP3A-dependent testosterone 6beta-hydroxylation activity in both human and animal liver microsomes.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
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.
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".