Hemodilutional anemia is associated with increased cerebral neuronal nitric oxide synthase gene expression
Bibliographic record
Abstract
Severe hemodilutional anemia may reduce cerebral oxygen delivery, resulting in cerebral tissue hypoxia. Increased nitric oxide synthase (NOS) expression has been identified following cerebral hypoxia and may contribute to the compensatory increase in cerebral blood flow (CBF) observed after hypoxia and anemia. However, changes in cerebral NOS gene expression have not been reported after acute anemia. This study tests the hypothesis that acute hemodilutional anemia causes cerebral tissue hypoxia, triggering changes in cerebral NOS gene expression. Anesthetized rats underwent hemodilution when 30 ml/kg of blood were exchanged with pentastarch, resulting in a final hemoglobin concentration of 51.0 +/- 1.2 g/l (n = 7 rats). Caudate tissue oxygen tension (Pbr(O(2))) decreased transiently from 17.3 +/- 4.1 to 14.4 +/- 4.1 Torr (P < 0.05), before returning to baseline after approximately 20 min. An increase in CBF may have contributed to restoring Pbr(O(2)) by improving cerebral tissue oxygen delivery. An increase in neuronal NOS (nNOS) mRNA was detected by RT-PCR in the cerebral cortex of anemic rats after 3 h (P < 0.05, n = 5). A similar response was observed after exposure to hypoxia. By contrast, no increases in mRNA for endothelial NOS or interleukin-1beta were observed after anemia or hypoxia. Hemodilutional anemia caused an acute reduction in Pbr(O(2)) and an increase in cerebral cortical nNOS mRNA, supporting a role for nNOS in the physiological response to acute anemia.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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) | 0.000 | 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 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".