Variation in Estradiol, Estradiol Precursors, and Estrogen-related Products in Nipple Aspirate Fluid from Normal Premenopausal Women
Bibliographic record
Abstract
The purpose of the study was to measure the concentrations of estradiol, its primary precursors, and factors with which it interacts in the breast, and determine their sources of variation. Nipple aspirate fluid (NAF) was collected from premenopausal women during the mid-luteal phase of the menstrual cycle. The fluid was diluted and unconjugated steroids were extracted. Estradiol was further purified by a solvent partition into aqueous NaOH. Androgens were measured in the non-phenolic fraction. Water-soluble, conjugated steroids and proteins were measured in the aqueous residue. All analytes were measured by immunoassays. Permutation methods were used to determine the correlations over multiple periods of time. The average concentration of estradiol in NAF was 435 pmol/L after purification but was many times higher when assayed without purification. Estrone and dehydroepiandrosterone (DHEA) sulfates were present in 3.7 and 75 micromol/L concentrations, respectively, while unconjugated androstenedione and DHEA were present in nanomole per liter concentrations. Lack of the steroid sulfates in NAF in 19% of subjects had no effect on NAF estradiol levels but was associated with a 77% lower concentration of unconjugated DHEA. Progesterone was present in concentrations that were 3- to 4-fold higher than normal serum concentrations (mean: 291 nmol/L). Cathepsin D, epidermal growth factor, and interleukin 6 had average values of 3.4 microg/mL, 424 ng/mL, and 1.7 ng/mL, respectively. Correlations between breasts were between 0.57 and 0.84 for the several analytes; correlations over time ranged from 0.64 and 0.93 with estrone sulfate highest in both categories. The lower correlation between breasts than within breasts indicates that local factors play an important role in determining the levels of many of these analytes in the breast. The high stability of the concentrations of several analytes over time indicates that fluctuations in environmental factors have little immediate effect on levels in the breast, and portends their utility as surrogate breast cancer risk markers.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| 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 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".