Medicine and Health Sciences Commons^™

The Impact Of Maternal Diabetes On Birth To Placental Weight Ratio And Umbilical Cord Oxygen Values With Implications For Fetal-Placental Development, Sheryl Choo, Barbra De Vrijer, Timothy R H Regnault, Hilary K Brown, Larry Stitt, Bryan S Richardson

Obstetrics & Gynaecology Publications

Introduction

We determined the impact of gestational diabetes (GDM) and pre-existing diabetes (DM) on birth/placental weight and cord oxygen values with implications for placental efficiency and fetal-placental growth and development.

Methods

A hospital database was used to obtain birth/placental weight, cord PO₂ and other information on patients delivering between Jan 1, 1990 and Jun 15, 2011 with GA >34 weeks (N = 69,854). Oxygen saturation was calculated from the cord PO₂ and pH data, while fetal O₂ extraction was calculated from the oxygen saturation data. The effect of diabetic status on birth/placental weight and cord oxygen values …

Expression And Localization Of Nrf2/Keap1 Signalling Pathway Genes In Mouse Preimplantation Embryos Exposed To Free Fatty Acids., Grace Dionne, Michele D. Calder, Dean H Betts, Basim Abu Rafea, Andrew J Watson

Obstetrics & Gynaecology Publications

Obese women experience greater incidence of infertility, with reproductive tracts exposing preimplantation embryos to elevated free fatty acids (FFA) such as palmitic acid (PA) and oleic acid (OA). PA treatment impairs mouse preimplantation development in vitro, while OA co-treatment rescues blastocyst development of PA treated embryos. In the present study, we investigated the effects of PA and OA treatment on NRF2/Keap1 localization, and relative antioxidant enzyme (Glutathione peroxidase; Gpx1, Catalase; Cat, Superoxide dismutase; Sod1 and γ-Glutamylcysteine ligase catalytic unit; Gclc) mRNA levels, during in vitro mouse preimplantation embryo development. Female mice were superovulated, mated, and embryos cultured in the presence …

Highlighting The Mechanistic Relationship Between Perinatal Depression And Preeclampsia: A Scoping Review, Mei Yuan, Samantha Bedell, Barbra De Vrijer, Genevieve Eastabrook, Jefferson C. Frisbee, Stephanie J. Frisbee

Obstetrics & Gynaecology Publications

Background: Although there is scientific literature supporting an association between depression and preeclampsia (PE), little is known about the underlying mechanistic pathways that may explain these observed associations. Thus, this study aimed to outline the relationship between depression and PE, and to highlight the underlying cardiovascular and metabolic risk factors that are common to both. Methods: A scoping review of the literature was conducted in Medline, Scopus, and Web of Science. Results: From 706 articles initially identified, 23 articles met the inclusion criteria and were included in this review. Although some studies reported a positive association between PE and postpartum …

Role Of Decorin At The Fetal-Maternal Interface, Chidambra D. Halari

Electronic Thesis and Dissertation Repository

The human placenta is an invasive tumor-like structure, this invasion being physiological. A subset of placental trophoblast called extra-villous trophoblast invades the uterine decidua and remodels uterine arteries into low-resistance, high-flow tubes to permit adequate flow of maternal blood to nourish the fetus. A poor extra-villous trophoblast invasion and uterine arterial remodeling can lead to fetal growth restriction and a serious pregnancy-associated maternal disease preeclampsia. Decorin, a leucine-rich proteoglycan produced by uterine decidual cells restrains multiple trophoblast functions: self-renewal and differentiation of trophoblast stem cells, migration, invasion, proliferation and endovascular differentiation. Additionally, decidual overproduction of decorin was associated with preeclampsia, …

Gestational Age Impacts Birth To Placental Weight Ratio And Umbilical Cord Oxygen Values With Implications For The Fetal Oxygen Margin Of Safety, Bryan S Richardson, Barbra De Vrijer, Hilary K Brown, Larry Stitt, Sheryl Choo, Timothy R H Regnault

Obstetrics & Gynaecology Publications

Background: We determined the impact of gestational age (GA) from near term to term to post-term on birth/placental weight ratio and cord oxygen values with implications for placental transport efficiency for oxygen, fetal O2 consumption relative to delivery or fractional O2 extraction, and oxygen margin of safety.

Materials and methods: A hospital database was used to obtain birth/placental weight ratios, cord PO2 and other information on patients delivering between Jan 1, 1990 and Jun 15, 2011 with GA > 34 completed weeks (N=69,852). Oxygen saturation was calculated from the cord PO2 and pH data, while fractional O2 extraction was calculated from …

Translating Developmental Origins Of Health And Disease In Practice: Health Care Providers' Perspectives., Monica L Molinaro, Marilyn Evans, Timothy Regnault, Barbra De Vrijer

Paediatrics Publications

Currently, there is limited knowledge on how health care providers perceive and understand the Developmental Origins of Health and Disease (DOHaD), which may impact how they inform patients and their families throughout the perinatal period. This qualitative descriptive study explored if and how health care providers counsel on in utero programming and future health outcomes with parents, both preconception and during pregnancy. One-on-one, semi-structured interviews were conducted with 23 health care providers from varying health disciplines including obstetrics and gynaecology, midwifery, paediatrics, endocrinology and internal medicine. Audiotaped interviews were transcribed verbatim and analysed using inductive thematic analysis. Three themes were …

Water-Fat Magnetic Resonance Imaging Of Adipose Tissue Compartments In The Normal Third Trimester Fetus, Stephanie A Giza, Tianna L Koreman, Simran Sethi, Michael R Miller, Debbie A Penava, Genevieve D Eastabrook, Charles A Mckenzie, Barbra De Vrijer

Obstetrics & Gynaecology Publications

BACKGROUND: Assessment of fetal adipose tissue gives information about the future metabolic health of an individual, with evidence that the development of this tissue has regional heterogeneity.

OBJECTIVE: To assess differences in the proton density fat fraction (PDFF) between fetal adipose tissue compartments in the third trimester using water-fat magnetic resonance imaging (MRI).

MATERIALS AND METHODS: Water-fat MRI was performed in a 1.5-T scanner. Fetal adipose tissue was segmented into cheeks, thorax, abdomen, upper arms, forearms, thighs and lower legs. PDFF and R2* values were measured in each compartment.

RESULTS: Twenty-eight women with singleton pregnancies were imaged between 28 and …

Effects Of Maternal Obesity And Gestational Diabetes Mellitus On The Placenta: Current Knowledge And Targets For Therapeutic Interventions, Samantha Bedell, Janine Hutson, Barbra De Vrijer, Genevieve Eastabrook

Obstetrics & Gynaecology Publications

Obesity and gestational diabetes mellitus (GDM) are becoming more common among pregnant women worldwide and are individually associated with a number of placenta-mediated obstetric complications, including preeclampsia, macrosomia, intrauterine growth restriction and stillbirth. The placenta serves several functions throughout pregnancy and is the main exchange site for the transfer of nutrients and gas from mother to fetus. In pregnancies complicated by maternal obesity or GDM, the placenta is exposed to environmental changes, such as increased inflammation and oxidative stress, dyslipidemia, and altered hormone levels. These changes can affect placental development and function and lead to abnormal fetal growth and development …

Drug Therapy During Pregnancy., Dongmei Sun, Janine R. Hutson, Facundo Garcia-Bournissen Md Phd

Paediatrics Publications

No abstract provided.

Developing And Implementing A Novel Mentorship Model (4+ 1) For Maternal, Newborn And Child Health In Rwanda, Anaclet Ngabonzima, Cynthia Kenyon, Celestin Hategeka, Aimee Josephine Utuza, Paulin Ruhato Banguti, Isaac Luginaah, David F Cechetto

Paediatrics Publications

BACKGROUND: There are a number of factors that may contribute to high mortality and morbidity of women and newborns in low-income countries. These include a shortage of competent health care providers (HCP) and a lack of sufficient continuous professional development (CPD) opportunities. Strengthening the skills and building the capacity of HCP involved in the provision of maternal, newborn and child health (MNCH) is essential to ensure quality care for mothers, newborns and children. To address this challenge in Rwanda, mentorship of HCPs was identified as an approach that could help build capacity, improve the provision of care and accelerate the …

Maternal Obesity Reduces Placental Autophagy Marker Expression In Uncomplicated Pregnancies, Matthew Cohen, Emily Guo, Aidan Pucchio, Barbra De Vrijer, Trevor G Shepherd, Genevieve Eastabrook

Obstetrics & Gynaecology Publications

AIM: Obesity has been associated with changes in autophagy and its increasing prevalence among pregnant women is implicated in higher rates of placental-mediated complications of pregnancy such as pre-eclampsia and intrauterine growth restriction. Autophagy is involved in normal placentation, thus changes in autophagy may lead to impaired placental function and development. The aim of this study was to investigate the connection between obesity and autophagy in the placenta in otherwise uncomplicated pregnancies.

METHODS: Immunohistochemistry and western blot analysis were done on placental and omental samples from obese (body mass index [BMI] ≥30 kg/m

RESULTS: As pre-pregnancy BMI increased, there was …

Transient Hyponatremia Of Prematurity Caused By Mild Bartter Syndrome Type Ii: A Case Report., Subhrata Verma, Rahul Chanchlani, Victoria Mok Siu, Guido Filler

Paediatrics Publications

BACKGROUND: Bartter syndrome subtypes are a group of rare renal tubular diseases characterized by impaired salt reabsorption in the tubule, specifically the thick ascending limb of Henle's loop. Clinically, they are characterized by the association of hypokalemic metabolic alkalosis, hypercalciuria, nephrocalcinosis, increased levels of plasma renin and aldosterone, low blood pressure and vascular resistance to angiotensin II. Bartter syndrome type II is caused by mutations in the renal outer medullary potassium channel (ROMK) gene (KCNJ1), can present in the newborn period and typically requires lifelong therapy.

CASE PRESENTATION: We describe a case of a prematurely born female infant presenting with …

A Core Outcome Set For Studies Of Gestational Diabetes Mellitus Prevention And Treatment, Aoife M Egan, Delia Bogdanet, Tomás P Griffin, Oratile Kgosidialwa, Mila Cervar-Zivkovic, Eugene Dempsey, John Allotey, Fernanda Alvarado, Cheril Clarson, Shamil D Cooray, Harold W De Valk, Sander Galjaard, Mary R Loeken, Michael J A Maresh, Angela Napoli, Paula M O'Shea, Ewa Wender-Ozegowska, Mireille N M Van Poppel, Shakila Thangaratinam, Caroline Crowther, Linda M Biesty, Declan Devane, Fidelma P Dunne

Paediatrics Publications

AIMS/HYPOTHESIS: The aim of this systematic review was to develop core outcome sets (COSs) for trials evaluating interventions for the prevention or treatment of gestational diabetes mellitus (GDM).

METHODS: We identified previously reported outcomes through a systematic review of the literature. These outcomes were presented to key stakeholders (including patient representatives, researchers and clinicians) for prioritisation using a three-round, e-Delphi study. A priori consensus criteria informed which outcomes were brought forward for discussion at a face-to-face consensus meeting where the COS was finalised.

RESULTS: Our review identified 74 GDM prevention and 116 GDM treatment outcomes, which were presented to stakeholders …

Labour Progression In Obese Women: Are Women With Increased Body Mass Index Having Unnecessary Cesarean Sections?, Caroline Shenouda, Aloka Wijesooriya, Amanda Toufeili, Michael R Miller, Debbie Penava, Barbra De Vrijer

Obstetrics & Gynaecology Publications

OBJECTIVE: This study sought to determine whether obese pregnant women undergo cesarean sections without an adequate trial of labour. This may affect future birth and pregnancy outcomes.

METHODS: A retrospective analysis was done on 526 parturients at Victoria Hospital in London, Ontario. Women were categorized according to parity and pre-pregnancy body mass index (BMI; normal weight, BMI 18.5-24.9 kg/m

RESULTS: Obese class II and III primiparous women required an additional 1.62 and 2.67 hours (P = 0.012), respectively, to reach a dilation of 10 cm compared with their normal weight counterparts; obese class II and III multiparous women required an …

Evidence Of Increased Hypoxia Signaling In Fetal Liver From Maternal Nutrient Restriction In Mice., Bethany N Radford, Victor K M Han

Paediatrics Publications

BACKGROUND: Intrauterine growth restriction (IUGR) is a pregnancy condition where fetal growth is reduced, and offspring from IUGR pregnancies are at increased risk for type II diabetes as adults. The liver is susceptible to fetal undernutrition experienced by IUGR infants and animal models of growth restriction. This study aimed to examine hepatic expression changes in a maternal nutrient restriction (MNR) mouse model of IUGR to understand fetal adaptations that influence adult metabolism.

METHODS: Liver samples of male offspring from MNR (70% of ad libitum starting at E6.5) or control pregnancies were obtained at E18.5 and differential expression was assessed by …

Placental Micrornas In Pregnancies With Early Onset Intrauterine Growth Restriction And Preeclampsia: Potential Impact On Gene Expression And Pathophysiology., Zain Awamleh, Gregory B Gloor, Victor K M Han

Paediatrics Publications

BACKGROUND:
A normally developed placenta is integral to a successful pregnancy. Preeclampsia (PE) and intrauterine growth restriction (IUGR) are two common pregnancy related complications that maybe a result of abnormal placental development. Placental microRNAs (miRNAs) have been investigated as potential biomarkers for these complications, as they may play a role in placental development and pathophysiology by influencing gene expression. The purpose of this study is to utilize next-generation sequencing to determine miRNA and gene expression in human placental (chorionic villous) samples from three distinct patient groups with early-onset (EO) PE, IUGR, or PE + IUGR.

METHODS:
Placental tissues were collected …

Incidence, Characteristics, And Outcomes Of Acute Kidney Injury Treated With Dialysis During Pregnancy And The Postpartum Period, Ainslie M. Hildebrand

Electronic Thesis and Dissertation Repository

Pregnancy-related acute kidney injury (AKI) may be associated with significant morbidity and mortality in young and often otherwise healthy women. We conducted a retrospective cohort study of all consecutive pregnancies between 1997 and 2011 in Ontario and describe the incidence, characteristics, and outcomes of AKI treated with dialysis (AKI-D) during pregnancy or within 12 weeks postpartum. Of 1,918,789 pregnancies, 188 were complicated by AKI-D (incidence proportion: 1 per 10,000, 95% confidence interval 0.8 to 1.1). Eight women died (4.3% versus 0.01% in the general population) and seven (3.9%) survivors remained dialysis-dependent four months after delivery. The presence of AKI-D was …

Implantation Failure In Female Kiss1-/- Mice Is Independent Of Their Hypogonadic State And Can Be Partially Rescued By Leukemia Inhibitory Factor., Michele Calder, Yee-Ming Chan, Renju Raj, Macarena Pampillo, Adrienne Elbert, Michelle Noonan, Carolina Gillio-Meina, Claudia Caligioni, Nathalie G Bérubé, Moshmi Bhattacharya, Andrew J Watson, Stephanie B Seminara, Andy V Babwah

Obstetrics & Gynaecology Publications

The hypothalamic kisspeptin signaling system is a major positive regulator of the reproductive neuroendocrine axis, and loss of Kiss1 in the mouse results in infertility, a condition generally attributed to its hypogonadotropic hypogonadism. We demonstrate that in Kiss1(-/-) female mice, acute replacement of gonadotropins and estradiol restores ovulation, mating, and fertilization; however, these mice are still unable to achieve pregnancy because embryos fail to implant. Progesterone treatment did not overcome this defect. Kiss1(+/-) embryos transferred to a wild-type female mouse can successfully implant, demonstrating the defect is due to maternal factors. Kisspeptin and its receptor are expressed in the mouse …

Laboring To Mother In The Context Of Past Trauma: The Transition To Motherhood, Berman Helene, Robin Mason, Jodi Hall, Susan Rodger, Catherine C. Classen, Marilyn K. Evans, Lori E. Ross, Gloria Alvernaz Mulcahy, Leonarda Carranza, Fatmeh Al-Zoubi

Journal Articles

The occurrence of interpersonal trauma is a reality for many women, with effects that often persist long after the traumatic events end. The purpose of this feminist grounded theory study was to examine how past trauma shaped the lives of women as they became new mothers. We recruited a purposive sample of 32 women from two Canadian communities and conducted semistructured, dialogic interviews during the second trimester of pregnancy. We analyzed data using thematic content analytic methods, including open coding whereby we read transcripts line by line and applied codes to portions of text that illustrated concepts or themes. The …

Low Birth Weight Male Guinea Pig Offspring Display Increased Visceral Adiposity In Early Adulthood., Ousseynou Sarr, Jennifer A Thompson, Lin Zhao, Ting-Yim Lee, Timothy Regnault

Paediatrics Publications

Uteroplacental insufficiency (UPI)-induced intrauterine growth restriction (IUGR) predisposes individuals to adult visceral obesity. We postulated that low birth weight (LBW) offspring, from UPI-induced IUGR pregnancies, would display a visceral adipose lipogenic molecular signature involving altered gene expression, phosphorylation status of proteins of the lipid synthesis pathway and microRNA (miR) expression profile, occurring in association with increased visceral adiposity. Normal birth weight (NBW) and LBW (obtained by uterine artery ablation) male guinea pig pups were fed a control diet from weaning to 145 days and sacrificed. Despite being lighter at birth, LBW pups displayed body weights similar to NBW offspring at …

Prenatal Programming Of Hepatic Glucose And Cholesterol Regulation In Male Rat Offspring By Chronic Intermittent Hypoxia, Waseem Iqbal

Electronic Thesis and Dissertation Repository

Obstructive sleep apnea (OSA) is a chronic disorder involving repetitive interruptions in breathing during sleep. Sufferers of OSA are exposed to chronic intermittent hypoxia (CIH), characterized by cyclical reductions in oxygen availability. A number of studies have established a link between OSA and various cardiovascular and metabolic comorbidities in adulthood, including hypertension, obesity, and type II diabetes. While the consequences of OSA in adults have been well described, the cross-generational impact of this condition and potential effects on fetal development are not known. Epidemiological and animal studies have demonstrated that physiological insults during pregnancy lead to diminished growth of offspring …

Stress-Inducible Phosphoprotein 1 Has Unique Cochaperone Activity During Development And Regulates Cellular Response To Ischemia Via The Prion Protein., Flavio H Beraldo, Iaci N Soares, Daniela F Goncalves, Jue Fan, Anu A Thomas, Tiago G Santos, Amro H Mohammad, Martin Roffé, Michele D Calder, Simona Nikolova, Glaucia N Hajj, Andre L Guimaraes, Andre R Massensini, Ian Welch, Dean H Betts, Robert Gros, Maria Drangova, Andrew J Watson, Robert Bartha, Vania F Prado, Vilma R Martins, Marco A M Prado

Obstetrics & Gynaecology Publications

Stress-inducible phosphoprotein 1 (STI1) is part of the chaperone machinery, but it also functions as an extracellular ligand for the prion protein. However, the physiological relevance of these STI1 activities in vivo is unknown. Here, we show that in the absence of embryonic STI1, several Hsp90 client proteins are decreased by 50%, although Hsp90 levels are unaffected. Mutant STI1 mice showed increased caspase-3 activation and 50% impairment in cellular proliferation. Moreover, placental disruption and lack of cellular viability were linked to embryonic death by E10.5 in STI1-mutant mice. Rescue of embryonic lethality in these mutants, by transgenic expression of the …

P38 Mapk Regulates Cavitation And Tight Junction Function In The Mouse Blastocyst., Christine E Bell, Andrew J Watson

Obstetrics & Gynaecology Publications

UNLABELLED: Blastocyst formation is essential for implantation and maintenance of pregnancy and is dependent on the expression and coordinated function of a series of proteins involved in establishing and maintaining the trans-trophectoderm ion gradient that enables blastocyst expansion. These consist of Na/K-ATPase, adherens junctions, tight junctions (TJ) and aquaporins (AQP). While their role in supporting blastocyst formation is established, the intracellular signaling pathways that coordinate their function is unclear. The p38 MAPK pathway plays a role in regulating these proteins in other cell types and is required for embryo development at the 8-16 cell stage, but its role has not …

Male Gender Promotes An Increased Inflammatory Response To Lipopolysaccharide In Umbilical Vein Blood., Shunaha Kim-Fine, Timothy Regnault, James S Lee, Sarah A Gimbel, Jill A Greenspoon, Jonathan Fairbairn, Kelly Summers, Barbra De Vrijer

Paediatrics Publications

OBJECTIVES: To establish gender-specific differences in maternal and fetal immune response in healthy human fetuses at term.

METHODS: Forty-five women with elective caesarean sections for uncomplicated singleton pregnancies were recruited for two studies. Using a multiplex biomarker immunoassay system, unstimulated maternal and fetal plasma concentrations of interleukin (IL)-1β, IL-1ra, IL-6, IL-8, macrophage inflammatory protein (MIP)-1α, and tumor necrosis factor (TNF)-α were measured from one study population. Lipopolysaccharide (LPS)-stimulated cytokine response was measured in a second study.

RESULTS: There were no significant gender differences in either maternal or fetal unstimulated plasma cytokine concentrations, but concentrations of the proinflammatory cytokines IL-1β and …

The Long And Short Of It: The Role Of Telomeres In Fetal Origins Of Adult Disease., Stephanie E Hallows, Timothy Regnault, Dean H Betts

Paediatrics Publications

Placental insufficiency, maternal malnutrition, and other causes of intrauterine growth restriction (IUGR) can significantly affect short-term growth and long-term health. Following IUGR, there is an increased risk for cardiovascular disease and Type 2 Diabetes. The etiology of these diseases is beginning to be elucidated, and premature aging or cellular senescence through increased oxidative stress and DNA damage to telomeric ends may be initiators of these disease processes. This paper will explore the areas where telomere and telomerase biology can have significant effects on various tissues in the body in IUGR outcomes.

Culture Medium, Gas Atmosphere And Mapk Inhibition Affect Regulation Of Rna-Binding Protein Targets During Mouse Preimplantation Development., Michele D Calder, Patricia H Watson, Andrew J Watson

Obstetrics & Gynaecology Publications

During oogenesis, mammalian oocytes accumulate maternal mRNAs that support the embryo until embryonic genome activation. RNA-binding proteins (RBP) may regulate the stability and turnover of maternal and embryonic mRNAs. We hypothesised that varying embryo culture conditions, such as culture medium, oxygen tension and MAPK inhibition, affects regulation of RBPs and their targets during preimplantation development. STAU1, ELAVL1, KHSRP and ZFP36 proteins and mRNAs were detected throughout mouse preimplantation development, whereas Elavl2 mRNA decreased after the two-cell stage. Potential target mRNAs of RBP regulation, Gclc, Slc2a1 and Slc7a1 were detected during mouse preimplantation development. Gclc mRNA was significantly elevated in embryos …

The Effect Of Intermittent Umbilical Cord Occlusion On Elastin Composition In The Ovine Fetus., Jennifer A Thompson, Sarah A Gimbel, Bryan S Richardson, Robert Gagnon, Timothy Regnault

Paediatrics Publications

This study aimed to determine the effect of varying degrees of intermittent umbilical cord occlusion (UCO) on arterial elastin composition. Over 4 days, chronically catheterized late gestation fetal sheep received 5 total UCO per day lasting 1 min/h (mild group: n = 6), 2 min/h (moderate group: n = 4), 3 min/h (severe group; n = 6); or no occlusion (control group: n = 7). Each group was evaluated for elastin content of the carotid and superior mesenteric artery (SMA), the arterial pressure response to UCO, and plasma cortisol concentration. Elastin content of the carotid artery was significantly increased by …

Ouabain Stimulates A Na+/K+-Atpase-Mediated Sfk-Activated Signalling Pathway That Regulates Tight Junction Function In The Mouse Blastocyst., Holly Giannatselis, Michele Calder, Andrew J Watson

Obstetrics & Gynaecology Publications

The Na(+)/K(+)-ATPase plays a pivotal role during preimplantation development; it establishes a trans-epithelial ionic gradient that facilitates the formation of the fluid-filled blastocyst cavity, crucial for implantation and successful pregnancy. The Na(+)/K(+)-ATPase is also implicated in regulating tight junctions and cardiotonic steroid (CTS)-induced signal transduction via SRC. We investigated the expression of SRC family kinase (SFK) members, Src and Yes, during preimplantation development and determined whether SFK activity is required for blastocyst formation. Embryos were collected following super-ovulation of CD1 or MF1 female mice. RT-PCR was used to detect SFK mRNAs encoding Src and Yes throughout preimplantation development. SRC and …

Intrauterine Growth Restriction Increases Fetal Hepatic Gluconeogenic Capacity And Reduces Messenger Ribonucleic Acid Translation Initiation And Nutrient Sensing In Fetal Liver And Skeletal Muscle., Stephanie R Thorn, Timothy Regnault, Laura D Brown, Paul J Rozance, Jane Keng, Michael Roper, Randall B Wilkening, William W Hay, Jacob E Friedman

Paediatrics Publications

Expression of key metabolic genes and proteins involved in mRNA translation, energy sensing, and glucose metabolism in liver and skeletal muscle were investigated in a late-gestation fetal sheep model of placental insufficiency intrauterine growth restriction (PI-IUGR). PI-IUGR fetuses weighed 55% less; had reduced oxygen, glucose, isoleucine, insulin, and IGF-I levels; and had 40% reduction in net branched chain amino acid uptake. In PI-IUGR skeletal muscle, levels of insulin receptor were increased 80%, whereas phosphoinositide-3 kinase (p85) and protein kinase B (AKT2) were reduced by 40%. Expression of eukaryotic initiation factor-4e was reduced 45% in liver, suggesting a unique mechanism limiting …

Mitogen-Activated Protein Kinase (Mapk) Pathways Mediate Embryonic Responses To Culture Medium Osmolarity By Regulating Aquaporin 3 And 9 Expression And Localization, As Well As Embryonic Apoptosis., Christine E Bell, Nathalie M K Larivière, Patricia H Watson, Andrew J Watson

Obstetrics & Gynaecology Publications

BACKGROUND: In order to advance the development of culture conditions and increase the potential for supporting normal preimplantation embryo development in vitro, it is critical to define the mechanisms that early embryos utilize to survive in culture. We investigated the mechanisms that embryos employ in response to culture medium osmolarity. We hypothesized that mitogen-activated protein kinase (MAPK) pathways mediate responses to hyperosmotic stress by regulating Aquaporin (AQP) 3 and 9 expression as well as embryonic apoptosis.

METHODS: Real-time reverse transcription and polymerase chain reaction and whole-mount immunofluorescence were used to determine the relative mRNA levels and protein localization patterns of …