Expression of PPARα, β, and γ in the Hartley guinea pig model of primary osteoarthritis
Bibliographic record
Abstract
Background Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily. Three isoforms have been identified: PPARa, PPARb-δ and PPARg. Several in vitro and in vivo studies suggest that PPARg may have protective roles in osteoarthritis (OA). So far, little is known about the pattern of PPAR expression during the progression of OA and cartilage degradation. Aim To investigate the expression of PPARa, b, and g in cartilage over the course of OA in the spontaneous Hartley guinea pig model. Methods Hartley guinea pigs were sacrificed at 2 (control group), 4, 8, and 12 (n =6p er group) month-old of age. Cartilage was obtained from the central portion of the medial tibial plateau. Cartilage degradation was evaluated histologically using the Osteoarthritis Research Society International (OARSI) guidelines. The expression of PPARa, b and g was analyzed by immunohistochemistry. The non-parametric Spearman test was used for the correlation analysis between the protein expression levels and histological scores. Results PPARa, b and g, were detected in medial tibial plateaus from control animals. There was no significant change in the levels of PPARa and PPARb over the course of OA. In contrast, PPARg expression decreased during the progression of OA. Correlation analysis revealed a negative correlation between PPARg levels and histological score of OA. Conclusion Expression of PPARg in cartilage decreased during the course of OA. These data suggest that loss of PPARg expression in cartilage may contribute to the pathogenesis of OA.
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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 | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".