Indirect Measurement of Bioavailable Testosterone with the Bayer Immuno 1 System
Bibliographic record
Abstract
Testosterone is the principal circulating androgen in men. A major fraction of testosterone is specifically bound with high affinity and low capacity to sex-hormone-binding globulin (SHBG), whereas most of the remaining testosterone is bound with low affinity to albumin (ALB), leaving only 1–2% to circulate as “free” testosterone (FT) not bound to protein in serum (1). Because the SHBG–testosterone complex dissociates very slowly in vitro (dissociation half-time, 20 s), SHBG-bound testosterone (SHBG-T) is not considered to be available for biologic action in tissues. According to the original “free hormone hypothesis”, only FT is able to enter target cells. Tait and Burstein (2), however, suggested that because testosterone is only loosely bound to ALB, this fraction is also available for tissue uptake (dissociation half-time, 1 s). The concept of bioavailable testosterone (BAT), also known as “non-SHBG-bound testosterone” [or both FT and ALB-bound testosterone (ALB-T)], was supported by in vitro kinetic calculations (3), but others (4)(5) have challenged the assumptions used for these calculations. Indeed, if SHBG facilitates entry of testosterone into tissues, as reported by Pardridge (6), then SHBG-T would also be “available” for tissue uptake and action. Controversy remains about the best biochemical measurement for testosterone function in humans. The initial clinical diagnostic evaluation for men with symptoms of hypogonadism involves measurement of the serum total testosterone. In situations such as hyper- and hypothyroidism, obesity, and the use of antiepileptic drugs, the correlation between clinical symptoms and the serum total testosterone concentration has been reported to be poor. This may be attributable in part to the inactivity of the SHBG-T fraction and to variation in the plasma concentration of SHBG in these situations. The fact that plasma SHBG changes during life and in several pathologic situations is well established (7)(8). It is currently common practice to …
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 distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 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) | 0.000 | 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 teacher head, 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".