<i>In Vivo</i> Receptor Assay with Multiple Ligand Concentrations: An Equilibrium Approach
Bibliographic record
Abstract
The ligand-receptor binding potential determined by PET studies at high ligand-specific radioactivity reflects both the receptor density and ligand-receptor affinity. This ambiguity has been resolved by various methods based on the administration of multiple unlabeled ligand concentrations. The authors aimed to implement and refine an approach to multiple ligand concentration receptor assay that combined maximum simplicity and a minimum of assumptions and model dependence that would nonetheless reliably distinguish density from affinity effects. The approach uses administration by bolus followed by infusion to obtain a true equilibrium between bound ligand and the other components of the ligand concentration, and does not require measurements of ligand in blood plasma. Four approaches to the optimization of the desired density and affinity parameters from the measured equilibrium data were implemented and compared in the analysis of raclopride studies performed in both normal control and MPTP-lesioned nonhuman primates. The authors conclude that the method is simple enough for routine use and yet reliable enough to apply in ongoing studies of both chronic and acute drug effects in the dopamine system.
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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 | 0.000 | 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".