Effect of Exogenously Administered Polyamine on the Structural Maturation and Enzyme Ontogeny of the Postnatal Rat Intestine
Bibliographic record
Abstract
The factors regulating the developmental changes in intestinal morphology and enzyme activity during the postnatal period are incompletely understood. Increased ornithine decarboxylase (ODC) and polyamine levels occur in association with increased mucosal growth seen just prior to weaning. The present work examines the effects of the polyamine spermidine, administered exogenously during early postnatal development in the rat, on structural and functional differentiation of the intestine. Young rats were fed 6 mumol of spermidine for either 1 day (P1) or 3 days (P3) prior to sacrifice on postnatal day 10. Control littermates were sacrificed at day 10 (C10) or at day 49 (C49) (postweanling [adult] reference). A loss of most of the well-developed characteristic endosomal complex and supranuclear giant lysosome was observed in the absorptive cells of the ileum and proximal colon in the spermidine-treated groups and was accompanied by a decline in N-acetyl-glucosaminidase activity to adult levels. A precocious appearance of sucrase and NaK ATPase activities was observed in the P1 group and these activities attained adult levels in the P3 group. This premature appearance of sucrase and NaK ATPase activities was associated with a decline in lactase levels. The exogenous administration of spermidine also elicited an increase in mucosal ODC activity.
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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 | 0.001 |
| 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".