Abstract 153: Dexamethasone Inhibits Regeneration and Causes Ventricular Aneurysm in the Neonatal Porcine Heart After Myocardial Infarction
Bibliographic record
Abstract
Background: The adult mammalian heart has limited ability to repair itself following injury. Zebrafish, newts and neonatal mice can regenerate cardiac tissue, largely by cardiac myocyte (CM) proliferation. More recently, we demonstrated that the hearts of neonatal pigs (2-day old) have regenerative capacity, likely driven by cardiac myocyte division, but this potential is lost immediately after birth. The current study aims to determine whether acute inflammation is required for CM regeneration after myocardial infarction (MI). Methods: We examined the role of acute inflammation on regenerative capacity of the neonatal pig heart (ages: 2 days postnatal) by intramuscular injection of dexamethasone (Dex) during the first week post-MI surgery. Myocardial scar and left ventricular function were determined by cardiac magnetic resonance (CMR) imaging. Bromodeoxyuridine pulse-chase labeling, histology, and immunohistochemistry were performed to study CM cytokinesis and to quantify myocardial fibrosis. Results: After MI, there was early and sustained recovery of cardiac function and wall thickness in the absence of fibrosis in 2-day old pigs. In contrast, piglets received Dex injection developed ventricular aneurysm and did not recover function. Dex limited CM cytokinesis via inhibiting aurora-B protein expression and caused mature scar and thinned walls at infarct site. Conclusions: Dex suppresses acute inflammation, inhibits CM regeneration, and causes ventricular aneurysm in neonatal pig hearts after MI.
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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 | 0.000 |
| 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".