Timing of steroid treatment is important for cerebral protection during cardiopulmonary bypass and circulatory arrest: minimal protection of pump prime methylprednisolone
Bibliographic record
Abstract
OBJECTIVES: The contact of cardiopulmonary bypass surface and patient's blood activates systemic inflammatory response which aggravates ischemia-reperfusion injury. This study evaluates the effects of cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA) on cerebral protection using different steroid administration protocols. METHODS: Eighteen (n=6/group) 4 week-old piglets were divided in three groups. Methylprednisolone (30 mg/kg) was administered intravenously 4 h prior to CPB in Group I, or added in pump prime in group II. Group III received no steroid. All animals were cooled to 15 degrees C followed by 100 min of DHCA, then rewarmed over 40 min and sacrificed 6 h after CPB. Post-operative weight gain, bioelectrical impedance, colloid oncotic pressure (COP) and interleukin-6 (IL-6) were evaluated. Determination of cerebral trypan blue and immunohistochemical assays of transforming growth factor (TGF)-beta1 and caspase-3 activities were performed. RESULTS: Post-operative % weight gain (13.0+/-3.8 (I) versus 26.4+/-9.9 (II) versus 22.6+/-6.4 (III), P=0.02); % bioimpedance reduction (14.5+/-8.0 (I) versus 38.3+/-13.3 (II) versus 30.5+/-8.0 (III), P=0.003); mean COP (mmHg) (14.9+/-1.8 (I) versus 10.9+/-2.0 (II) versus 6.5+/-1.8 (III), P=0.0001) and systemic IL-6 levels (pg/ml) (208.2+/-353.0 (I) versus 1562.1+/-1111.4 (II) versus 1712.3+/-533.2 (III), P=0.01) were significantly different between the groups. Spectrophotometric analysis of cerebral trypan blue (ng/g dry weight) was significantly different between the groups (0.0053+/-0.0010 (I) versus 0.0096+/-0.0026 (II) versus 0.0090+/-0.0019 (III), P=0.004). TGF-beta1 scores were 3.3+/-0.8 (I) versus 1.5+/-0.8 (II) versus 1.5+/-0.5 (III), P<0.05, groups I versus II and I versus III. Remarkable perivascular caspase-3 activity was observed in groups II and III. CONCLUSION: Different timing of steroid administration results in different inflammatory mediator response. Steroid in CPB prime is not significantly better than no steroid treatment, while systemic steroid pre-treatment significantly decreases systemic manifestation of inflammatory response and brain damage.
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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 | 0.005 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 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".