Decreased cerebrovascular response to CO<sub>2</sub>in post-menopausal females with COPD: role of oxidative stress
Bibliographic record
Abstract
Chronic obstructive pulmonary disease (COPD) is associated with cerebrovascular abnormalities and an overproduction of reactive oxygen species. We hypothesised that COPD patients have oxidant-related cerebrovascular dysfunction. Our main objective was to evaluate cerebrovascular reactivity and its relationship with oxidative stress in females with COPD. We studied eight females with moderate COPD and 10 healthy female control subjects of similar age. Transcranial Doppler ultrasound assessed cerebral blood flow (CBF) velocity during hypercapnia. Plasma was assessed at rest for DNA oxidation, advanced oxidation protein products, lipid peroxidation, nitrotyrosine, antioxidant enzyme activity (glutathione peroxidase and catalase) and end-products of nitric oxide metabolism. Moderate COPD patients showed decreased cerebrovascular sensitivity to carbon dioxide (CO(2)) (COPD 1.17 ± 0.54 versus control 2.15 ± 0.73 cm · s(-1) · mmHg(-1); p<0.01). COPD patients had higher levels of DNA and lipid oxidation, advanced oxidation protein products and higher glutathione peroxidase activity (p<0.05). Controlling for measures of oxidative stress (DNA and lipid oxidation, and advanced oxidation protein product) eliminates statistically significant differences between the COPD and control groups in the CBF sensitivity to CO(2). Females with moderate COPD were found to have cerebrovascular dysfunction. Our results suggest that increased levels of systemic oxidative stress may have implications in the cerebrovascular dysfunction observed during hypercapnia in COPD.
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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) | 0.002 | 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".