John R. G. Challis
University of Toronto
392 Papers
5.8K Citations
John R. G. Challis is an academic researcher from University of Toronto. The author has contributed to research in topics: Fetus & Placenta. The author has an hindex of 70, co-authored 392 publications. Previous affiliations of John R. G. Challis include McMaster University & Canadian Institutes of Health Research.
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Papers
The Effects of Chorioamnionitis and Betamethasone on 11β, Hydroxysteroid Dehydrogenase Types 1 and 2 and the Glucocorticoid Receptor in Preterm Human Placenta:
TL;DR: There could be an increased fetal exposure to maternal glucocorticoids in cases of chorioamnionitis as a result of changes in the expression and activity of the placental 11β HSD isozymes.
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Early changes in prostaglandin concentrations in ovine maternal and fetal plasma, amniotic fluid and from dispersed cells of intrauterine tissues before the onset of ACTH-induced pre-term labour.
TL;DR: The results imply a causal relationship between rising PG and later myometrial contractions, rather than PG changes resulting from enhanced uterine activity, and there is a selective increase in plasma PGF-2 alpha concentrations before the onset of delivery.
Gestational changes in prostanoid concentrations in intrauterine tissues and fetal fluids from pregnant sheep, and the relation to prostanoid output in vitro.
TL;DR: Results indicate that prostanoid production by fetal and maternal intrauterine tissues is, in general, lower on Day 50 than at the other times of pregnancy studied.
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Local Modulation by 11β-Hydroxysteroid Dehydrogenase of Glucocorticoid Effects on the Activity of 15-Hydroxyprostaglandin Dehydrogenase in Human Chorion and Placental Trophoblast Cells1
TL;DR: Whether glucocorticoid regulation of PGDH activity in placenta and chorion could be regulated indirectly by 11β-HSD activity was determined.
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Corticotropin-Releasing Hormone and Proopiomelanocortin-Derived Peptides Are Present in Human Myometrium
Vicki L. Clifton,J F Telfer,A. J. Thompson,I. T. Cameron,T. G. Teoh,Stephen J. Lye,John R. G. Challis +6 more
TL;DR: It is demonstrated that levels of CRH and POMC peptide in human uterine tissue change with pregnancy and that CRH is produced locally by myometrial smooth muscle cells.
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