Morphometric Analysis of Monkey Cerebral Arteries Exposed in vivo to Whole Blood, Oxyhemoglobin, Methemoglobin, and Bilirubin
Bibliographic record
Abstract
Whether vasospasm results from smooth muscle contraction or from arterial wall infiltration by cells and other material is subject to debate. Computer-assisted image analysis was used to measure lumen area, total wall area, and area of tunica media plus tunica intima of cross-sections of monkey right middle cerebral arteries (MCAs), exposed in vivo for 6 days to whole blood (n = 4), oxyhemoglobin (OxyHb, n = 5), methemoglobin (MetHb, n = 5), bilirubin (n = 5), mock cerebrospinal fluid (CSF, n = 6), and supernatant fluid from an incubated mixture of autologous blood and mock CSF (n = 5). Five control (left) MCAs from each group and 4 MCAs contracted in vitro with potassium chloride were measured. Significant angiographic vasospasm occurred in groups receiving whole blood, supernatant fluid, and OxyHb (p less than 0.05). There was significant correlation (r = 0.58, p less than 0.05) between right MCA diameter on angiography and diameter calculated from lumen area. When compared to effects of mock CSF, OxyHb significantly increased total wall area. When right and left MCAs were compared within groups, total wall area increased in every group with significant increases in groups exposed to mock CSF, OxyHb, and bilirubin (p less than 0.05). No changes developed in area of tunica media plus tunica intima, whether comparing right versus left MCAs within groups or right MCAs between groups. Contraction in vitro did not significantly increase total wall area or area of tunica media plus tunica intima. Light microscopy demonstrated inflammatory debris in the tunica adventitia of arteries from every group. This study shows that whole blood, OxyHb, and supernatant fluid, which contains OxyHb, cause vasospasm. Increases in total wall area are not sufficient to account for luminal narrowing, and therefore, changes such as cell proliferation and arterial wall fibrosis in the intima or media apparently do not contribute primarily to arterial narrowing of vasospasm but could be related to persistence of narrowing. Vessel wall thickening, which does occur, is caused by increased tunica adventitia area only and is nonspecific in that it develops after injection of substances not associated with vasospasm. The data are consistent with the hypothesis that oxyHb causes vasospasm (both angiographic and morphologic) by inducing muscle contraction in the media.
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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".