Publications by authors named "Amanda Sampson"

The aetiology and progression of hypertension involves various endogenous systems, such as the renin angiotensin system, the sympathetic nervous system, and endothelial dysfunction. Recent data suggest that vascular inflammation may also play a key role in the pathogenesis of hypertension. This study sought to determine whether high intraluminal pressure results in vascular inflammation.

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Background: Migrant workers have been identified in Europe, North America, Asia and Australia as a particularly vulnerable working population with a higher risk of work-related injury and mortality compared to non-migrant workers. Lack of English language proficiency is associated with an increased risk of work-related injury. Whether lack of English proficiency influences post-injury recovery or return to work outcomes remains unknown.

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It is now becomingly increasingly evident that the functions of the mammalian Y chromosome are not circumscribed to the induction of male sex. While animal studies have shown variations in the Y are strongly accountable for blood pressure (BP), this is yet to be confirmed in humans. We have recently shown modulation of adaptive immunity to be a significant mechanism underpinning Y-chromosome-dependent differences in BP in consomic strains.

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The essential role of the Y chromosome in male sex determination has largely overshadowed the possibility that it may exert other biologic roles. Here, we show that Y-chromosome lineage is a strong determinant of perivascular and renal T-cell infiltration in the stroke-prone spontaneously hypertensive rat, which, in turn, may influence vascular function and blood pressure (BP). We also show, for the first time to our knowledge, that augmented perivascular T-cell levels can directly instigate vascular dysfunction, and that the production of reactive oxygen species that stimulate cyclo-oxygenase underlies this.

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Vascular dysfunction is a hallmark of hypertension and the strongest risk factor to date for coronary artery disease. As Y chromosome lineage has emerged as one of the strongest genetic predictors of cardiovascular disease risk to date, we investigated if Y chromosome lineage modulated this important facet in the stroke-prone spontaneously hypertensive rat (SHRSP) using consomic strains. Here, we show that vascular dysfunction in the SHRSP is attributable to differential cyclooxygenase (COX) activity with nitric oxide (NO) levels playing a less significant role.

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Nitroxyl anion (HNO) donors are currently being assessed for their therapeutic utility in several cardiovascular disorders including heart failure. Here, we examine their effect on factors that precede atherosclerosis including endothelial cell and monocyte activation, leucocyte adhesion to the endothelium and macrophage polarization. Similar to the NO donor glyceryl trinitrate (GTN), the HNO donors Angeli's salt (AS) and isopropylamine NONOate (IPA/NO) decreased leucocyte adhesion to activated human umbilical vein endothelial cells (HUVECs) and mouse isolated aorta.

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Aim: To identify factors reported with negative and positive outcomes for caregivers of the traumatic brain injury and spinal cord injury cohorts, to investigate what interventions have been studied to support carers and to report what effectiveness has been found.

Methods: Scoping systematic review. Electronic databases and websites were searched from 1990 to December 2015.

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Many studies report sexual dimorphism in the fetal programming of adult disease. We hypothesized that there would be differences in the age-related decline in renal function between male and female intrauterine growth-restricted rats. Early-life growth restriction was induced in rat offspring by administering a low-protein diet (LPD; 8.

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Background And Purpose: Angiotensin AT2 receptors are upregulated in disease states such as atherosclerosis and blockade of the AT2 receptors exacerbates plaque formation. Direct stimulation of these receptors is anti-atherogenic but the mechanisms and pathways involved remain unknown. We examined the effect of direct AT2 receptor stimulation with Compound 21 (C21) on the leukocyte adhesion cascade in vitro, right through to plaque formation in vivo.

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Objectives: Apert syndrome is characterized by craniosynostosis and complex hand and foot syndactyly, and an increased risk of brain, palate, heart, and visceral malformations, and intellectual disability. This study aims to describe the structural brain abnormalities detected by dedicated neuroimaging of fetuses with Apert syndrome.

Methods: Retrospective review of ultrasound and magnetic resonance imaging brain imaging obtained in six fetuses with a diagnosis of Apert syndrome.

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The lineage of the Y chromosome accounts for up to 15 to 20 mm Hg in arterial pressure. Genes located on the Y chromosome from the spontaneously hypertensive rat (SHR) are associated with the renin-angiotensin system. Given the important role of the renin-angiotensin system in the renal regulation of fluid homeostasis and arterial pressure, we hypothesized that the origin of the Y chromosome influences arterial pressure via interaction between the intrarenal vasculature and the renin-angiotensin system.

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Background: The genetic contribution to salt-sensitivity in hypertension remains unclear. We have previously identified a quantitative trait locus on chromosome 2 in stroke-prone spontaneously hypertensive rats (SHRSPs) responsible for an increase in SBP in response to a salt challenge. This response is blunted in the congenic SHRSP strain with the Wistar-Kyoto (WKY) chromosome 2 region (10 cM) introgressed (SP.

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Unlabelled: This single visit study examined whether endothelial function, in addition to cardiovascular (CV) risk factors and plasma microparticle content, was normalised in 15 patients with type 2 diabetes + acute coronary syndrome (ACS) (6 weeks-6 months post cardiac event) undergoing standard clinical care compared to 16 sex- and age-matched healthy controls.

Results: While total and low-density lipoprotein (LDL) cholesterol levels were well controlled in the patients with type 2 diabetes + ACS, residual CV risk profiles such as increased body mass index (BMI), systolic blood pressure, glucose levels and triglycerides and lower high-density lipoprotein (HDL) levels were still apparent. Endothelium-dependent responses to acetylcholine (ACh) were significantly lower in type 2 diabetes + ACS patients compared to controls.

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Sex differences exist in the regulation of arterial pressure and renal function by the renin-angiotensin system (RAS). This may in part stem from a differential balance in the pressor and depressor arms of the RAS. In males, the ACE/AngII/AT(1)R pathways are enhanced, whereas, in females, the balance is shifted towards the ACE2/Ang(1-7)/MasR and AT(2)R pathways.

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Background: Sex differences in the expression of the angiotensin (Ang) II receptors and angiotensin-converting enzyme 2 (ACE2) have been hypothesized to be a potential mechanism contributing to sex-specific differences in arterial pressure. Currently, sex differences in the expression of the angiotensin receptors and ACE2 remain undefined.

Objectives: The aim of this study was to define the postnatal ontogeny of mRNA expression, from birth to adulthood, of the Ang II and Ang-(1-7) receptors and ACE2 in male and female rats.

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Background: Congenital diaphragmatic hernia (CDH) is a potentially correctable anatomical defect that continues to represent a significant cause of stillbirth and neonatal death.

Aims: To describe the outcomes of fetuses diagnosed antenatally with CDH.

Methods: A retrospective cohort study of fetuses with CDH detected antenatally at our fetal medicine unit between January 1996 and December 2008.

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The complex role of the renin-angiotensin-system (RAS) in arterial pressure regulation has been well documented. Recently, we demonstrated that chronic low-dose angiotensin II (ANG II) infusion decreases arterial pressure in female rats via an AT(2)R-mediated mechanism. Estrogen can differentially regulate components of the RAS and is known to influence arterial pressure regulation.

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Sexual dimorphism in arterial pressure regulation has been observed in humans and animal models. The mechanisms underlying this gender difference are not fully known. Previous studies in rats have shown that females excrete more salt than males at a similar arterial pressure.

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This article describes and illustrates a novel method of microarray data analysis that couples model-based clustering and binary classification to form clusters of `response-relevant' genes; that is, genes that are informative when discriminating between the different values of the response. Predictions are subsequently made using an appropriate statistical summary of each gene cluster, which we call the `meta-covariate' representation of the cluster, in a probit regression model. We first illustrate this method by analysing a leukaemia expression dataset, before focusing closely on the meta-covariate analysis of a renal gene expression dataset in a rat model of salt-sensitive hypertension.

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We present a case in which the unusual cerebral malformations of thanatophoric dysplasia (TD) were identified on a 21-week fetal US and confirmed by antenatal MRI, postmortem imaging and autopsy. TD is the most common lethal skeletal dysplasia and is characterized by short long bones, which are often bowed (type 1), a small thorax, and skull deformities. There is also a recognised constellation of abnormalities of the brain primarily affecting the temporal lobes that, although well described in the postmortem setting, are not widely recognized in fetal imaging.

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The renin-angiotensin system is a far more complex enzymatic cascade than realized previously. Mounting evidence suggests sex-specific differences in the regulation of the renin-angiotensin system and arterial pressure. We examined the hemodynamic responses, angiotensin II receptor subtypes, and angiotensin-converting enzyme 2 gene expression levels after graded doses of angiotensin II in males and females.

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1. The aim of this study was to investigate the effect of chronic angiotensin II (AngII) infusion on the circadian rhythms of arterial blood pressure, heart rate (HR) and locomotor activity (ACT) in male and female rats. 2.

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We investigated the roles of the renin-angiotensin system and the significance of interactions between angiotensin II and nitric oxide, in responses of regional kidney perfusion to electrical renal nerve stimulation (RNS) in pentobarbital sodium-anesthetized rabbits. Under control conditions, RNS (0.5-8 Hz) reduced total renal blood flow (RBF; -89 +/- 3% at 8 Hz) and cortical perfusion (CBF; -90 +/- 2% at 8 Hz) more than medullary perfusion (MBF; -55 +/- 5% at 8 Hz).

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Background: Localisation of the non-palpable Implanon is useful to confirm its presence or to assist the surgeon with its removal. Previous studies have suggested that almost all non-palpable Implanon implants can be located with ultrasound in phantoms.

Aim: To determine whether diagnostic ultrasound is a reliable method for localising non-palpable Implanon implant in-vivo.

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