Sex steroid levels near the term of pregnancy do not alter lipopolysaccharide‐induced fever in oophorectomized rats
Bibliographic record
Abstract
NEW FINDINGS: What is the central question of this study? Do plasma concentrations of oestrogen and progesterone similar to those observed near the term of pregnancy alter basal core temperature or the core temperature response to bacterial pyrogen in oophorectomized rats? What is the main finding and its importance? Plasma concentrations of oestrogen and progesterone similar to those observed near the term of pregnancy do not alter basal core temperature or the overall febrile response to bacterial pyrogen in oophorectomized rats. Thus, our data do not support the hypothesis that sex steroids mediate the regulated decrease in basal core temperature or the attenuated/absent core temperature response to bacterial pyrogen observed in rats near the term of pregnancy. Fever, an important component of the host's defence response to infection, is absent or attenuated in rats near the term of pregnancy concurrent with major changes in blood concentrations of the sex steroids, oestrogen and progesterone. The present experiments were carried out to determine the potential role of oestrogen and progesterone in mediating the altered core temperature response to bacterial pyrogen. For the experiments, oestrogen and progesterone were administered alone or in combination to oophorectomized, non-pregnant rats in concentrations that mimicked plasma levels of these hormones measured in pregnant rats on days 17, 18, 19 and 20 of gestation. Treatment with oestrogen or progesterone alone or in combination did not alter basal core temperature or the overall febrile response (i.e. 12 h fever index) to an EC50 dose of Escherichia coli lipopolysaccharide (i.e. 20 μg kg(-1) ). Administration of oestrogen did, however, influence the early core temperature response and increase the latency to fever following administration of lipopolysaccharide. Thus, our data provide evidence that although oestrogen may influence the early core temperature response to lipopolysaccharide, sex steroids in concentrations similar to those observed late in gestation do not alter the overall febrile response and are therefore unlikely to mediate the attenuated or absent febrile response to bacterial pyrogen in rats near the term of pregnancy.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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 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".