Applying the indicator amino acid oxidation technique in the domestic cat: results of a pilot study and development of a non-steady state prediction model
Bibliographic record
Abstract
The aim of this study was to evaluate whether the indicator amino acid oxidation (IAAO) method could be applied in the domestic cat. Six adult male cats were used in a replicated 3 × 3 Latin square design. Three semi-synthetic diets were developed: a methionine (Met) and total sulfur AA (TSAA) deficient diet (T-BASAL; 0.24% Met+Cys - DM basis) and two Met and TSAA-sufficient diets in which either dl-Met (T-DLM) or 2-hydroxy-4-(methylthio)-butanoic acid (T-MHA) were supplemented, respectively, on an equimolar basis to meet the TSAA requirement (0.34%). After a 2-d diet adaptation, IAAO studies were performed. Cats were offered 13 small meals. The sixth meal contained a priming dose (4.8 mg/kg-BW) of l-[1-13C]-Phe and the remaining meals a constant dose (1.04 mg/kg-BW). Breath samples were collected every 25 min to measure 13CO2 enrichment. The following morning, fasted blood samples were collected. Cats returned to the T-BASAL top dressed with a dl-Met solution for 4 d prior to being fed a new dietary treatment. Isotopic steady state was evaluated through visual inspection. Data were analyzed using PROC GLIMMIX procedure in SAS 9.4. While 13CO2 enrichment was successfully captured in breath samples, cats failed to reach 13CO2 steady state. Thus, a non-steady state isotope model was developed and coded in ACSLX (V3.1.4.2) individually for each cat on each study day to predict 13CO2 enrichment, and then, calculate oxidation of l-[1-13C]-Phe (F13CO2). A higher predicted F13CO2 was observed for cats fed T-BASAL compared to the others (P < 0.05), while no differences were observed between T-DLM and T-MHA (P > 0.05). Cats fed T-DLM tended to have higher plasma Met concentrations compared to those fed T-BASAL with cats fed T-MHA intermediate (P = 0.0867). Plasma homocysteine concentrations were higher in cats fed T-BASAL compared to the others (P < 0.05), while threonine concentrations tended to be higher in cats fed T-BASAL compared to those fed T-MHA (P = 0.0750). In conclusion, short-term provision of a semi-synthetic diet deficient in Met may elicit a metabolic response aiming to conserve Met. The successful quantification of 13CO2 enrichment in breath and the higher predicted F13CO2 in cats fed a Met deficient diet suggest that the IAAO technique may be used in cats. Adaptations in the isotope protocol should be made to achieve 13CO2 steady state in breath and avoid mathematical modeling to predict F13CO2.
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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 | 0.002 | 0.002 |
| 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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| 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".