Circulatory and Respiratory Physiology Commons^™

Towards 3d In Vitro Models For The Study Of Cardiovascular Tissues And Disease, Claire M. Brougham, Alan J. Ryan, Carolina D. Garciarena, Steve W. Kerrigan, Fergal J. O'Brien

Articles

The field of tissue engineering is developing biomimetic biomaterial scaffolds which are showing increasing therapeutic potential for the repair of cardiovascular tissues. However, a major opportunity exists to use them as 3D in vitro models for the study of cardiovascular tissues and disease in addition to drug development and testing. These in vitro models can span the gap between 2D culture and in vivo testing thus reducing cost, time and the ethical burden of current approaches. This review outlines the progress to date and requirements for the development of ideal in vitro 3D models for blood vessels, heart valves and …

Inverse Relationship Between Physical Activity, Adiposity And Arterial Stiffness In Healthy Middle-Aged Subjects, Oscar Mac Ananey, B Mc Loughlin, A Leonard, L Maher, P Gaffney, G Boran, V Maher

Articles

BACKGROUND:

Several obesity related factors are reported to exacerbate premature arterial stiffening, including inactivity and metabolic disarray. The aim of the present study was to investigate the relationship between physical activity, arterial stiffness and adiposity using objective methods. To further explore the role of adiposity in this complex process, obesity associated anthropometric and humoral biomarkers were measured.

METHODS:

Seventy-nine healthy, lifelong non-smoking, subjects were recruited. Habitual physical activity was measured using accelerometry. Arterial stiffness (augmentation index; AIx & pulse wave velocity; PWV), was measured using tonometry. Body composition was estimated using bioimpedence. Adipose associated biomarkers, leptin and adiponectin, were also …

Comparison Of Semi-Automated And Manual Measurements Of Carotid Intima-Media Thickening, Oscar Mac Ananey, G Mellotte, V Maher

Articles

Carotid intima-media thickening (CIMT) is a marker of both arteriosclerotic and atherosclerotic risks. Technological advances have semiautomated CIMT image acquisition and quantification. Studies comparing manual and automated methods have yielded conflicting results possibly due to plaque inclusion in measurements. Low atherosclerotic risk subjects (n = 126) were recruited to minimise the effect of focal atherosclerotic lesions on CIMT variability. CIMT was assessed by high-resolution B-mode ultrasound (Philips HDX7E, Phillips, UK) images of the common carotid artery using both manual and semiautomated methods (QLAB, Phillips, UK). Intraclass correlation coefficient (ICC) and the mean differences of paired measurements (Bland-Altman method) were used …

Cardiac Output Is Not Related To The Slowed O2 Uptake Kinetics In Type 2 Diabetes, Oscar Mac Ananey, J Malone, S Warmington, D O'Shea, S Green, M Egana

Articles

Abstract

PURPOSE:

This study aimed to investigate whether cardiac output (CO) responses were related to VO2 kinetics during cycling in type 2 diabetes.

METHODS:

A total of 9 middle-aged women with uncomplicated type 2 diabetes, 9 nondiabetic overweight women, and 11 nondiabetic lean women were recruited. Initially, the ventilatory threshold (VT) and peak VO2 were determined during a maximal graded test. Then, on two separate days, subjects completed three 7-min bouts of constant-load cycling at each of three intensities: 50% VT, 80% VT, and midpoint between VT and peak VO2 (50% Δ). CO (inert gas rebreathing) was recorded at 30 …

Effect Of Type 2 Diabetes On The Dynamic Response Characteristics Of Leg Vascular Conductance During Exercise, Oscar Mac Ananey, H Reilly, D O'Shea, M Egana, S Green

Articles

Abstract

In this study we tested the hypothesis that type 2 diabetes impairs the dynamic response of leg vascular conductance (LVC) during exercise. LVC (leg blood flow/mean arterial pressure) responses were studied during intermittent contractions of the calf muscle in subjects with type 2 diabetes (n = 9), heavy controls (n = 10) and lean controls (n = 8) using a biexponential function and an estimate of the mean response time (MRT). The time constant of the second phase of LVC was significantly greater in type 2 diabetes (66.4 ± 29.2 s) than the heavy (22.2 ± 13.4 s) and …