A Meta-analysis on the Intrinsic Contractile Properties of Airway Smooth Muscle
Bibliographic record
Abstract
Abstract Airway smooth muscle (ASM) drives bronchospasm in asthma, and its exaggerated contraction allegedly contributes to airway hyperresponsiveness (AHR). The reasons behind AHR in asthma are incompletely elucidated. In particular, whether intrinsic alterations in the contractile properties of ASM play a role in this process remains an open question. We have performed a systematic review and meta-analysis of available studies reporting experimental data comparing the contractile and relaxing properties of asthmatic and control ASM strips from adult human patients in response to cholinergic agents, histamine and isoproterenol. We specifically included only work written in English. Our main outcomes were EC50 (or ER50) to assess ASM sensitivity and F max (or R max) to assess ASM maximal contractile (or relaxing) response to the agent studied. Results of a total of 18 studies were finally reviewed, summarized, and included in the analyses. The available evidence indicates that asthmatic ASM strips are hyposensitive and generate less force in response to cholinergic agents compared to control ASM strips. Asthmatic ASM strips are also hyposensitive to the relaxation induced by isoproterenol. Three studies have quantified the maximal relaxation induced by isoproterenol and the results suggest that there is no difference between asthmatic and non-asthmatic ASM strips. Sensitivity and the maximal contractile response (F max) to histamine are similar in asthmatic and control ASM strips. Overall, these results suggest that AHR in asthma is not due to an increased sensitivity or reactivity of ASM to cholinergic agents or histamine. However, a decreased sensitivity to the relaxation induced by isoproterenol, and perhaps other β-adrenergic agents, could contribute to AHR in asthma.
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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 | 0.015 | 0.030 |
| Meta-epidemiology (narrow) | 0.003 | 0.001 |
| Meta-epidemiology (broad) | 0.016 | 0.042 |
| Bibliometrics | 0.005 | 0.006 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.004 | 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".