The Effect of Age and Duration of Disease on Airway Structure in Fatal Asthma
Bibliographic record
Abstract
We hypothesized that if airway remodeling is related to duration of asthma, that when matched for severity, the airways of older adults should show greater alterations than the airways of younger adults. Using standard morphometric techniques, we compared airways with basement membrane perimeters (Pbm) between 2 and 10 mm from young individuals who died of asthma (n = 14, range 17-23 yr), and older individuals with fatal asthma (n = 13, range 40-49 yr). Comparisons were also made with normal airways from age-matched adults. Wall area was increased in old individuals with fatal asthma compared with young individuals with fatal asthma, primarily due to greater adventitial area, whereas wall area in young individuals with fatal asthma was not different from control subjects. Within muscle bundles the connective tissue matrix was increased around individual cells in individuals with asthma, unrelated to age. After adjustment for this change, smooth muscle area in both asthma groups was still greater than in age-matched control subjects, in old individuals with fatal asthma 4-fold greater (p = 0.04), and in young individuals with fatal asthma 2-fold greater (p = 0.03). Airway narrowing was increased in old versus young individuals with fatal asthma, with both groups more narrowed than control subjects. Intralumenal obstruction and subepithelial collagen in the two asthma groups were significantly greater than in control subjects, but there was no age effect. These data provide support for the hypothesis that there is an increase in airway wall area, including smooth muscle, and airway narrowing with increasing duration of severe asthma or with older age. The observation that total wall thickness was not greater in young individuals with young fatal asthma than in control subjects suggests that factors other than airway wall geometry contribute to the pathogenesis of fatal attacks in this age group.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.002 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".