Publications by authors named "Joey St-Pierre"

Self-reported maternal prenatal stress (MPS) has been associated with earlier febrile seizure (FS) age of onset in offspring. Studies are needed to understand how the biological systems associated with exposure to psychological MPS are linked to seizure disorders in children. The present study aimed to investigate whether placental markers of MPS are linked to FS incidence and age at first occurrence.

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Respiratory monitoring, using impedance with implanted telemetry in socially housed animals, was not possible until the recent development of digital signal transmission. The objective of this study was to evaluate digital telemetry monitoring of cardiopulmonary parameters (respiratory rate, tidal volume, minute volume, electrocardiography (DII), systemic arterial blood pressure, physical activity, and body temperature) in conscious, single-housed, non-rodent species commonly used in toxicology studies following administration of positive/negative controls (saline, dexmedetomidine, morphine, amphetamine, and doxapram), and also, the effects of various social housing arrangements in untreated female and/or male cynomolgus monkeys, Beagle dogs, and Göttingen minipigs (n = 4 per species). Aggressions were observed in socially housed male minipigs, however, which prevented pair-housed assessments in this species.

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We investigated the effects of a natural disaster (a sudden flood) as a source of prenatal maternal stress (PNMS) on the placental glucocorticoid system and glucose transporters. Whether the gestational age at the time of the flood moderated these effects was also evaluated. Placental samples were collected from participants in the 2011 Queensland Flood Study (QF2011) who were pregnant in the first or second trimester at the onset of the flood.

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Normalization with proper reference genes is a crucial step in obtaining accurate mRNA expression levels in RT-qPCR experiments. GeNorm and NormFinder are two commonly used software packages that help in selecting the best reference genes, based on their expression stability. However, GeNorm does not take into account a group variable, such as sample sex, in its calculation.

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The role of placental serotonin has been an active topic of research notably because of its crucial role in brain development. However, which cell types synthesize serotonin in human placenta remains unknown. Moreover, it is not known if the two tryptophan hydroxylase isoforms (TPH1 and TPH2), the rate-limiting enzymes in serotonin biosynthesis, are expressed in placenta.

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Lead interferes with cortisol blood concentration, increases the risk of obstetrical complications, and could alter fetal development. The placenta controls maternal cortisol transfer to the fetus by the activity of the type 2 11β-hydroxysteroid dehydrogenase (11β-HSD2), which converts cortisol into inactive cortisone. This study determines the effect of lead on the expression and activity of the placental 11β-HSD2 in human trophoblast-like BeWo cells.

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Fetuses are exposed to many environmental perturbations that can influence their development. These factors can be easily identifiable such as drugs, chronic diseases or prenatal maternal stress. Recently, it has been demonstrated that the serotonin synthetized by the placenta was crucial for fetal brain development.

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In recent decades there has been an increasing recognition of the need to account for sex and gender in biology and medicine, in order to develop a more comprehensive understanding of biological phenomena and to address gaps in medical knowledge that have arisen due to a generally masculine bias in research. We have noted that as basic experimental biomedical researchers, we face unique challenges to the incorporation of sex and gender in our work, and that these have remained largely unarticulated, misunderstood, and unaddressed in the literature. Here, we describe some of the specific challenges to the incorporation of sex and gender considerations in research involving cell cultures and laboratory animals.

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Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) is a rapid and high throughput gene expression quantification technology. In order to obtain accurate results, several key experimental design and standardization steps must be rigorously followed as previously described in the Minimum Information for Publication of Quantitative Real-Time PCR Experiments (MIQE) guidelines. This study investigates the effect of reference gene normalization and the impact of RNA degradation on gene expression of 8-oxoguanine DNA glycosylase in human placenta from pregnancies complicated by preeclampsia and gestational diabetes mellitus and their gestation-matched controls.

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