Respiratory burst in alveolar macrophages exposed to urban particles is not a predictor of cytotoxicity
Bibliographic record
Abstract
We examined the utility of respiratory burst measurements in alveolar macrophages to assess adverse cellular changes following exposure to urban particles. Cells were obtained by bronchioalveolar lavage of Fisher 344 rats and exposed (0-100 μg/well) to urban particles (EHC-93, SRM-1648, SRM-1649, PM2.5), the soluble (EHC-93sol) and insoluble (EHC-93insol) fractions of EHC-93 (EHC-93tot), mineral particles (TiO(2), SiO(2)) and metal oxides (iron III oxide, iron II/III oxide, copper II oxide, nickel II oxide). The particle-induced respiratory burst was measured by chemiluminescence for 2h after the addition of particles. The cells were then stimulated with phorbol 12-myristate 13-acetate (PMA), yeast Zymosan fragments (Zymosan), or lipopolysaccharide plus interferon-gamma (LPS/IFN-γ) and the stimulant-induced respiratory burst was measured. Independently of the potential of particles to induce directly a respiratory burst, exposure to most particles attenuated the subsequent stimulant-induced burst. The notable exception was SiO(2), which produced a strong respiratory burst upon contact with the macrophages and enhanced the subsequent response to PMA or LPS/IFN-γ. Based on the degree of inhibition of the stimulant-dependent respiratory burst, particles were clustered into groups of high (SRM-1649, iron III oxide), intermediate (EHC-93tot, EHC-93insol, SRM-1648, VERP, iron II/III oxide, copper II oxide), and low (EHC-93sol, SiO(2), TiO2 and nickel II oxide) potency. Across these clusters, the potency of the particles to inhibit the stimulant-dependent respiratory burst showed poor correlation with cytotoxicity determined by XTT reduction assay.
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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".