Obtaining information on gastric emptying patterns in horses from appearance of an oral acetaminophen dose in blood plasma.
Bibliographic record
Abstract
The rate of passage of nutrients from the stomach to the small intestine is a regulated process that can influence metabolic responses to a meal. Acetaminophen has been used as an indicator of gastric emptying because of its negligible absorption in the stomach and high coefficient of absorption in the proximal small intestine. Seven horses were given an oral dose of 20 mg/kg acetaminophen simultaneously with a 5 ml/kg gastric gavage of water or a 20% glucose solution containing nothing else, tri-acetin, octanoic acid or maize oil. The five different liquid meals were administered on consecutive weeks in a randomized sequence. To identify the pattern of gastric emptying on different meals, several candidate models of gastric emptying and acetaminophen kinetics were evaluated from least squared fits to the 35 sets of acetaminophen concentrations in serial blood samples collected from a jugular catheter. In all models, absorption was assumed to be nil from the stomach and instantaneous from the small intestine. Elimination from the circulation followed first-order kinetics. Assuming continuous, zero-order outflow of acetaminophen from the stomach yielded R2 for fits to the plasma appearance curves that ranged from 0.18 to 0.97 and AIC from 69 to 109. The average±standard deviation (SD) gastric emptying rate was 231±176 mg/min from a dose of 8412±819 mg. Assuming first-order kinetics of acetaminophen outflow relative to gastric contents did not improve the goodness-of-fit. The average±SD emptying rate constant was 0.046±0.042/min. An oscillation in residuals over time from both models was hypothesized to be due to the initial dose intermittently flowing out of the stomach. Two parameters (w and p) were added to the zero-order and first-order emptying models to simulate periodic gushing of gastric contents for w min every p min, where w < p. From the zero-order model, the duration of each gush (w) was estimated to be 52 min, on average, and the period between gushes (p) was 192 min. Representing intermittency of gastric outflow as a sequence of identically spaced pulses resulted, on average, in an 80% increase in the estimate of the rate constant for acetaminophen clearance from plasma. Periodicity parameters for variably intermittent gastric emptying models were obtained from the sign of plasma acetaminophen appearance runs. The zero-order variably intermittent model performed better for meals of glucose plus octanoic acid, whereas the first-order model was superior for the other meals.
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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 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| 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 | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".