Human cardiac ischemia‐reperfusion injury: Blunted stress response with age
Bibliographic record
Abstract
BACKGROUND AND AIM: Autophagy is a cytoprotective recycling mechanism, capable of digesting dysfunctional cellular components, and this process is associated with pro-survival outcomes. Autophagy may decline in the aging myocardium, thereby contributing to cardiac dysfunction. However, it remains to be established how autophagy responds to ischemia-reperfusion stress with age. METHODS: Samples from the right atrium were collected from young (≤50 years; n = 5) and aged (≥70 years; n = 11) patients before and immediately following cardioplegic arrest during coronary artery bypass grafting surgery, a model of human ischemia-reperfusion injury. RESULTS: Mitochondrial content, as assessed by a cohort of mitochondrial markers, exhibited an overall decrease in the aging myocardium (p = 0.01). In response to IR, COX-I (0.63 vs. 0.91, p = 0.01) increased in young, but not in aged patients (interaction effect p = 0.08). Reductions in LC3-I (0.48 vs. 0.28, p = 0.02) along with declines in TFEB and TFE3 (0.63 vs. 0.20, p = 0.05; 0.71 vs. 0.20, p = 0.01) were observed with age suggesting an impairment in the aged myocardium. Aged patients also displayed an inability to mount an appropriate response to IR compared to their young counterparts, specifically, increases in v-ATPase and NIX (1.06 vs 0.69, p = .01; 1.15 vs 0.69, p = .001) were not seen in the aged. CONCLUSION: Our data demonstrate a reduced cardiac mitochondrial content and a blunted mitochondrial response to ischemia with age, accompanied by a possible impairment in mitophagy. These findings support an age-associated inability of the atrial myocardium to mount appropriate adaptive responses to stress.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| 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".