Publications by authors named "Averil Y Warren"

Introduction: Pre-eclampsia is a hypertensive gestational disorder that affects approximately 5% of all pregnancies.

Objectives: As the pathophysiological processes of pre-eclampsia are still uncertain, the present case-control study explored underlying metabolic processes characterising this disease.

Methods: Maternal peripheral plasma samples were collected from pre-eclamptic (n = 32) and healthy pregnant women (n = 35) in the third trimester.

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Introduction: The function of the placental vasculature differs considerably from other systemic vascular beds of the human body. A detailed understanding of the normal placental vascular physiology is the foundation to understand perturbed conditions potentially leading to placental dysfunction.

Methods: Behaviour of human stem villous arteries isolated from placentae at term pregnancy was assessed using wire myography.

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Distinguishing between fetal and maternal inflammatory responses is necessary for understanding the immune interplay either side of the placenta. Fetal immunity reaches maturity during extrauterine life and while basic inflammatory responses afford a certain degree of protection, fetuses are vulnerable to infection. With the discovery of inflammasomes-intracellular scaffolds that facilitate the elaboration of reactions resulting in the release of mature interleukin-1β (IL-1β)-it is necessary to consider how inflammatory stimuli are processed.

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The human endometrial epithelium is pivotal to menstrual cycle progression, implantation and early pregnancy. Endometrial function is directly regulated by local factors that include pH, oxygen tension and ion concentrations to generate an environment conducive to fertilization. A superfamily of potassium channels characterized by two-pore domains (K2P) and encoded by KCNK genes is implicated in the control of the cell resting membrane potential through the generation of leak currents and modulation by various physicochemical stimuli.

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Premature delivery remains a serious risk factor in pregnancy, with currently licensed tocolytics unable to offer significant improvement in neonatal outcome. Further understanding of the regulators of uterine contractility is required to enable the development of novel and more effective tocolytic therapies. The transglutaminase family is a class of calcium-dependent, transamidating enzymes, of which tissue transglutaminase 2 is a multifunctional enzyme with roles in cell survival, migration, adhesion, and contractility.

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Article Synopsis
  • Preeclampsia and intrauterine growth restriction are serious pregnancy-related conditions that can impact both mother and baby's health and lead to future cardiovascular issues due to endothelial dysfunction and poor placental blood flow.
  • The study aimed to examine changes in specific lipid molecules, eicosanoids known as EETs and HETEs, in the placentas of women with preeclampsia and growth-restricted pregnancies in comparison to healthy pregnancies.
  • Findings showed that preeclamptic placentas had higher levels of certain HETEs linked to inflammation and vasoconstriction, suggesting these eicosanoids may contribute significantly to the development of preeclampsia.
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Cytochrome P-450 (CYP450) enzymes of the CYP2 and -4 family in humans metabolize arachidonic acid to generate bioactive epoxyeicosatrienenoic acids (EETs) and hydroxyeicosatetrenoic acids (HETEs). We report significantly higher levels of CYP 2J2 protein expression following the onset of labor (n = 6, P < 0.05), implying increased EET-generating capacity within the uterus.

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The purinergic receptor P2X(7) is activated by extracellular adenosine 5'-triphosphate (ATP) and promotes the efficient release of interleukin-1 beta. The authors examine protein and molecular expression of the P2X(7) receptor and its ability to stimulate interleukin-1 beta release in cord blood mononuclear cells (CBMCs) from placentae of term nonlaboring and laboring women. They show both mRNA and protein (78 kDa) expression for the P2X( 7) receptor in CBMCs of parturient and nonparturient women.

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A reversed-phase liquid chromatography negative ion electrospray tandem mass spectrometry (LC/ESI-MS/MS) method was developed and validated to quantify a range of physiologically relevant eicosanoids, including 5,6-, 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids (EETs); 5-, 8-, 9-, 12-, and 15-hydroxyeicosatetraenoic acids (HETEs), and 5,6-, 8,15-, and 12,20-dihydroxyeicosatetraenoic acids (DiHETEs) in human intrauterine tissues. A solid-phase extraction method was employed to extract the eicosanoids, and gradient LC separation was performed on a Kromasil C(18) column. Mass spectrometric detection was performed by multiple reaction monitoring over a 31-min run time.

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Reactive oxygen species (ROS) have the propensity to cause macromolecular damage with consequent modification of cellular function. We investigated the effects of two particular oxidants, superoxide (O2(-)) anions and hydrogen peroxide (H2O2), on oxytocin-induced myometrial contractility using biopsies from women undergoing Caesarean section at term gestation. Isometric tension recordings were performed and concentration-response curves derived after addition of test agents.

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Objective: To evaluate the effect of natural progesterone on the relaxant effect of ritodrine on pregnant human oxytocin-induced myometrial contractility.

Study Design: Isometric tension recordings were performed under physiologic conditions on isolated myometrial strips taken from low-risk term pregnant women undergoing elective cesarean section. Cumulative effects of natural progesterone (10 (-11) to 10 (-5) mol/L) on oxytocin-induced myometrial contractility were evaluated.

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Objective: In preeclampsia, endothelium-dependent function is markedly aberrant. Myometrial resistance arteries from women with preeclampsia show a minimal, wholly nitric oxide-mediated, bradykinin-induced relaxation. Our aim was to test that phosphodiesterase 5 (PDE5) inhibition could improve endothelium-dependent function in preeclampsia.

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Objectives: (1) To investigate a possible association between myometrial and placental artery vasoreactivity and perfusion at the basal and chorionic plates, respectively. (2) To confirm that myometrial arteries from women with pre-eclampsia and intrauterine growth restriction exhibit an attenuated endothelium-dependent vasodilatory response.

Methods: Women with normal pregnancy, pre-eclampsia and intrauterine growth restriction had a magnetic resonance scan to assess placental perfusion using a technique called intravoxel incoherent motion.

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Objectives: Preeclampsia (PE) is a multisystem disease unique to human pregnancy. Abnormal placentation results in placental hypoperfusion leading to the secretion of a factor(s) by the placenta. Our aim was to investigate whether neurokinin B (NKB) is the circulating factor associated with PE.

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Objectives: We aimed to compare placental small artery function from women with pre-eclampsia and normal pregnancy. In particular, we wished to test the hypothesis that these arteries respond differently to an endothelium-dependent vasodilator, to the presence of nitric oxide, and to the presence of cyclic monophosphate nucleotides.

Methods: A small vessel wire myograph was used to study placental arteries (200 to 550 microm).

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