Fetal-placental calcium metabolism in mice partly or fully deficient in parathyroid hormone
Bibliographic record
Abstract
It is well established that parathyroid hormone (PTH) plays an essential role in regulating calcium and bone homeostasis in the adult. The role, if any, of PTH in fetal-placental mineral homeostasis has been uncertain. Therefore, the purpose of the present doctoral research was to examine the role of PTH in fetal-placental calcium homeostasis. It was hypothesized that: PTH, despite its low circulating levels during fetal life, plays an important role in regulating not only fetal blood calcium and skeletal development, but also placental calcium transfer. To address this, two different genetic mouse models of PTH deficiency were utilized. The Pthtm1Dgo knockout (i.e. Pth null) mice served as a model of complete absence of PTH because they have enlarged parathyroids that are incapable of making PTH, while the Gcm2tm1Kry knockout ( i.e. Gcm2 null) mice served as a model of severe hypoparathyroidism because they lack parathyroids but have some PTH. Both nulls displayed a fetal hypoparathyroid phenotype, experiencing hypocalcemia, hypomagnesemia, hyperphosphatemia, low amniotic fluid mineral content, and reduced skeletal mineral content. When Pth null fetuses were treated in utero with PTH (1-84), placental calcium transfer increased, and placental gene expression was altered. It was also discovered that PTH is expressed in the placenta of wild-type and Gcm2 null fetuses. Thus, from the present study it is evident that PTH does indeed play an important role in fetal-placental mineral homeostasis. More specifically, PTH is important for fetal blood calcium, fetal skeletal development, is expressed locally in the placenta, regulates placental gene expression, and may directly regulate the transfer of calcium from mother to fetus.
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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) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".