Harry A. Silber

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OBJECTIVES We sought: 1) to investigate the relationship between vascular wall shear stress and flow-mediated dilation (FMD) in humans, and 2) to investigate whether this relationship could explain why FMD is greater in small arteries. BACKGROUND Arterial wall shear stress (WSS) is considered to be the primary stimulus for the endothelial-dependent FMD(More)
BACKGROUND Persons with high normal blood pressure (BP) or mild hypertension who also have an exaggerated BP response to exercise are at risk for worsening hypertension. The mechanisms that explain this relationship are unknown. We examined the relationships of endothelial vasodilator function and of aortic stiffness with exercise BP. METHODS Subjects(More)
When food is heated to high temperatures, the characteristic "browning" generates advanced glycation end products (AGEs). AGEs are associated with an increased risk of cardiovascular disease, diabetes, and other adverse outcomes. Whether dietary AGEs are absorbed and are harmful to human health remains highly controversial. The objective of this study was(More)
BACKGROUND Increased left ventricular (LV) mass is associated with greater cardiovascular disease risk. Recent studies have also shown an association of increased LV mass with attenuated endothelium-dependent coronary flow reserve. Less is known about the association between LV mass and endothelium-dependent flow-mediated dilatation (FMD) in peripheral(More)
Flow-mediated dilation (FMD) is strongly dependent on arterial size, but the reasons for this phenomenon are poorly understood. We have previously shown that FMD is greater in small brachial arteries because the shear stress stimulus is greater in small brachial arteries. However, it is unclear why the shear stimulus is greater in small arteries.(More)
We investigated whether endothelial-dependent arterial constriction during reduced shear can be measured using phase contrast magnetic resonance imaging (PCMRI). A cross-section of the femoral artery was acquired during a 5-minute distal occlusion in 33 subjects. Systolic shear rate and radius were measured from the velocity profile via a best-fit parabola.(More)
It is often challenging to assess cardiac filling pressure clinically. An improved system for detecting or ruling out elevated cardiac filling pressure may help reduce hospitalizations for heart failure. The blood pressure response to the Valsalva maneuver reflects left heart filling pressure, but its underuse clinically may be due in part to lack of(More)
The Findlay centrifugal pump is unique in its two-stage pumping mechanisms and in its complementary interrelationship of the stages to each other and to the exit system, and it forms an extremely efficient unit. The first stage is a lift force pump as an inlet. The second and major stage is a shear force pump. Twenty-six prototypes, many multiply modified,(More)
BACKGROUND Procedures that induce ischemic pre-conditioning during cardiac surgery will require a rapidly visualized hemodynamic monitor of acute ischemia. This study investigated the utility of a continuous loop tracing of left ventricular pressure (LVP) plotted against its derivative (dP/dt) as a visual beat-to-beat monitor of acute changes in myocardial(More)
A comparison between the prospective and retrospective respiratory navigator gating in MR coronary angiography was performed with eight normal subjects. A three-dimensional (3D) ECG-gated fast gradient echo pulse sequence was used for image data acquisition. The results show that the MR coronary angiography obtained using retrospective gating retains a(More)