Biologic Response of the Intervertebral Disc to Static and Dynamic Compression In Vitro
Bibliographic record
Abstract
STUDY DESIGN: This study attempts to determine the biologic response of the intervertebral disc to static and dynamic compression in vitro. OBJECTIVE: To quantitate and compare the changes of histology, Type I and II collagens, aggrecan, interleukin (IL)-1beta, and tumor necrosis factor (TNF)-alpha expression, and apoptosis in rabbit intervertebral discs following static and dynamic compression in vitro. SUMMARY OF BACKGROUND DATA: Compressive stimuli associated with weight-bearing and loading of the intervertebral disc are thought to be important regulators of disc cell metabolism. Very little is known about the different types of mechanical stimuli that may achieve regulation of intervertebral disc cell metabolism. We examined the biologic response of the rabbit intervertebral discs when exposed to static and dynamic compression in vitro. METHODS: The rabbit intervertebral disc explants were in vitro subjected to unconfined uniaxial compression. Static compression of 0.5 and 1 MPa and dynamic compression of 0.5 and 1 MPa were applied at the frequency of 0.1 and 1 Hz for 6 hours, respectively. After loaded with different types of mechanical stimuli, disc explants were examined for histologic changes, collagen I, collagen II, aggrecan, IL-1beta and TNF-alpha expression, and apoptosis. RESULTS: The static compressive load was found to suppress gene expression for collagens and aggrecan in the disc, whereas the disc under dynamic compression exhibited significant anabolic change with increase in gene expression for Type I and II collagen and aggrecan. The regional difference of the responses to mechanical loading in vitro was found between the anulus fibrosus and nucleus pulposus. All loading conditions caused marked histologic changes, up-regulation of IL-1beta and TNF-alpha expression, and increase in TUNEL-positive cells in the intervertebral discs, with the most significant from control was that when statically loaded. CONCLUSION: Mechanical loading is involved in the physiology and pathology of disc degeneration. Static and dynamic compression may induce different biologic response of the intervertebral disc: static compression has catabolic role on the disc, whereas the dynamic load at appropriate level may benefit the synthetic activity and anabolic response of the disc.
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 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 | 0.000 |
| 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".