Hydroxyl radical adduct of 5-aminosalicylic acid: A potential marker of ozone-induced oxidative stress
Bibliographic record
Abstract
The use of 5-aminosalicylic acid in assessment of reactive oxygen species formation was investigated by in vitro Fenton and ozonation reactions, and by in vivo ozone-exposure experiments. Enzymatic hydroxylation was evaluated by a microsomal assay. Fischer 344 male rats (250 g) injected with 5-aminosalicylic acid (100 mg x kg(-1) i.p.; 30 min) were exposed to ozone (0, 1, 2 ppm; nose only, 2 h); bronchoalveolar lavage, lung homogenates, and plasma were recovered. Oxidation products of 5-aminosalicylic acid were as follows: salicylic acid, by deamination; 2,3-dihydroxybenzoic acid and 2,5-dihydroxybenzoic acid, from radical or enzymatic hydroxylation; 5-amino-2-hydroxy-N,N'-bis(3-carboxy-4-hydroxyphenyl)-1,4-benzoquinonediimine, a condensation product of oxidized 5-aminosalicylic acid; and 5-amino-2,3,4,6-tetrahydroxybenzoic acid, attributed to hydroxyl radical attack without deamination, identified by HPLC electrochemical (HPLC-EC) detector system analysis and by GC-MS analysis of trimethylsilyl derivatives. 5-Aminotetrahydroxybenzoic acid was not formed enzymatically. 5-Aminotetrahydroxybenzoic acid, but not 5-aminosalicylic acid, was significantly elevated in bronchoalveolar lavage (+86%) and lung homogenates (+56%) in response to 2 ppm ozone (p < 0.05); no significant changes were detected in plasma. The data indicate that hydroxylation of 5-aminosalicylic acid is a potential specific probe for in vivo oxidative stress.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.001 |
| 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 teacher head, 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".