Differential matrix degradation and turnover in early cartilage lesions of human knee and ankle joints
Bibliographic record
Abstract
OBJECTIVE: To determine whether there are differences in matrix turnover within early cartilage lesions of the ankle (talocrural) joint compared with the knee (tibiofemoral) joint that may help explain differences in the prevalence of osteoarthritis in these 2 joints. METHODS: Cartilage removed from lesions of the tali and femoral condyles was analyzed for type IIB collagen messenger RNA, C-terminal type II procollagen propeptide (CPII), the collagenase cleavage neoepitope (Col2-3/4C(short)), and the denaturation epitope (Col2-3/4m). The content of collagen, glycosaminoglycan, and epitope 846 of aggrecan was quantitated. RESULTS: In ankle lesions, there was an up-regulation of markers of synthesis (CPII [P = 0.07]; epitope 846 [P < or = 0.0001]), but these were down-regulated in the knee (CPII [P = 0.1]; epitope 846 [P = 0.004]). In lesions of the knee, but not the ankle, there was an up-regulation of collagen degradation markers (P = 0.008). On a molar basis, there was 24 times more cleavage epitope than denaturation epitope in knee lesions compared with ankle lesions. CONCLUSION: The up-regulation of matrix turnover that is seen in early cartilage lesions of the ankle would appear to represent an attempt to repair the damaged matrix. The increase in collagen synthesis and aggrecan turnover seen in ankle lesions is absent from knee lesions. Instead, there is an increase in type II collagen cleavage. Together with the differences in collagen denaturation, these changes point to an emphasis on matrix assembly during early lesion development in the ankle and to degradation in the knee, resulting in fundamental differences in matrix turnover in these lesions.
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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 | 0.001 |
| 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 | 0.000 |
| 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".