Wildfire-borne Particulate Matter (WFPM): Effects on Bronchorelaxation in Human Small Airways
Bibliographic record
Abstract
Abstract Rationale: Wildfires, emerging as significant natural disasters, pose negative impact on lung health in millions of people. Particulate Matter (PM) are the predominant pollutants emitted from wildfires. Characterizing the respiratory injury by wildfire-borne PM (WFPM) will identify novel strategies in managing airway disease exacerbations by WFPM. We hypothesized that WFPM impair bronchorelaxation in human small airways to exacerbate airway diseases such as asthma. Methods: Size-fractionated WFPM collected during the June 2023 Canadian wildfire event (June 5th -9th 2023) was utilized in this study. Environmentally relevant in vitro doses of WFPM fractions were calculated using the Multiple Path Particle Dosimetry (MPPD) model and the Distorted Grid (DG) model. Human precision-cut lung slices (hPCLS) from non-asthma donor lungs were exposed to WFPM0.1 (10 or 100 ng mass/slice) or vehicle for 24 h and isoproterenol (Iso)-induced bronchodilation was measured in airways pre-contracted with carbachol. To assess effects of WFPM on transient immunocytes, THP-1 cells differentiated with Phorbol 12-myristate 13 acetate (PMA) were treated with Vehicle, WFPM0.1 or WFPM0.1-2.5 for 24 h and the phagocytic activity, ROS generation and cytotoxicity were measured. Results: WFPM0.1-treated airways showed reduced bronchorelaxation response to the β2-adrenergic agonist isoproterenol (n=3 donors, Iso EC50 Mean±SD: Veh 0.18± 0.27 µM Vs 100 ng WFPM0.1 0.60±0.56 µM; Iso EC25 Mean±SD: Veh 0.048± 0.07 µM Vs 100 ng WFPM0.1 0.21±0.19 µM). In THP-1 cells, WFPM0.1 – 2.5 (delivered mass 2.68 x10-3μg) increased ROS production, while both WFPM0.1 (delivered mass 6.34 x10-3μg) and WFPM0.1-2.5 (delivered mass 2.68 x10-3μg) attenuated phagocytic activity by 34% compared to the vehicle. Conclusions: WFPM0.1 decrease β2 agonist-induced bronchodilation in human small airways. WFPM0.1 and WFPM 0.1-2.5 also impair phagocytic activity of PMA-differentiated THP-1 macrophages. Significance: The findings demonstrate that WFPM fractions impact lung health by impairing agonist-induced bronchorelaxation and potentially attenuating the protective functions of immunocytes in lungs.
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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 | 0.000 | 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".