Cisternal Sustained Release Dihydropyridines for Subarachnoid Hemorrhage
Bibliographic record
Abstract
Nimodipine improved outcome in patients with subarachnoid hemorrhage (SAH) although hypotension limited the dose that could be administered systemically. Subarachnoid delivery of nicardipine or nimodipine may be more efficacious. We tested the efficacy of cisternal application of sustained release nicardipine and nimodipine in SAH in monkeys and dogs, respectively. SAH was created in 13 cynomolgus macaques by placement of autologous blood clot around right middle cerebral, anterior cerebral, and internal carotid arteries. Placebo poly-D,L-lactide coglycolide (PLGA), nicardipine PLGA or mibefradil PLGA was inserted in the clots. Catheter and computed tomography angiography (CTA) were performed at baseline and 7 days later (day 7). Cerebral infarction was assessed on day 7 by magnetic resonance imaging. Six dogs underwent baseline angiography and injection of autologous blood plus PLGA or nimodipine-loaded PLGA microparticles into the cisterna magna. Blood injection was repeated 2 days later and angiography 7 and 14 days later. Animals were euthanized and brains were examined histologically. Cerebrospinal fluid and serum nimodipine concentrations were measured. Nicardipine, but not mibefradil PLGA decreased vasospasm in monkeys (paired t-tests) although there was no significant effect on infarctions see on MRI. In dogs, nimodipine-PLGA produced high local concentrations of nimodipine that were associated with reduced basilar artery vasospasm. No untoward histological effects were observed. There was no reduction in microthrombi in animals treated with nimodipine PLGA compared to placebo PLGA. Site-specific, sustained release formulations of dihydropyridines can deliver high concentrations to the cerebrospinal fluid without causing systemic side effects, and may reduce angiographic vasospasm after SAH. Since nimodipine improves outcome in patients with SAH without necessarily preventing vasospasm, further studies are warranted.
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 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 | 0.001 | 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) | 0.000 | 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".