Detection of parathyroid hypertensive factor in parathyroid cell culture mediaRapid in vitro stimulation of parathyroid hypertensive factor secretion by 1,25-dihydroxyvitamin D3
Bibliographic record
Abstract
Parathyroid hypertensive factor (PHF) is a circulating hypertensive factor found in a proportion of human essential hypertensive patients and spontaneously hypertensive rats. This study describes a new immunoassay system for detection of PHF in rat parathyroid cell culture media. We have developed a hybridoma which secreted specific anti-PHF antibodies of IgM isotype. Research study demonstrated no detectable cross-reactivity with rat parathyroid hormone or shorter parathyroid hormone fragments, different vasoactive substances and plasma proteins. PHF assay is a one step competitive assay using a microtiter plates coated with monoclonal antibodies. Culture media supernatant is diluted (1:10) in a specimen diluent and incubated with horseradish peroxidase labeled PHF in microtiter plate wells. The assay has a dynamic range of 0–2.0 units/ml, with lower detection limit of 0.02 units/ml. Assay reproducibility was determined by testing three samples over the dynamic range; a precision of 14% (inter assay) and 8.3% (intra assay) was achieved. PHF immunoassay results are in agreement with previously used bioassay and show significant difference between the level of PHF secreted by parathyroid cells from spontaneously hypertensive and Wistar-Kyoto rats. In conclusion PHF enzyme immunoassay is rapid, highly sensitive and can provide a useful tool for further investigation of the physiological role of PHF.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".