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OBJECTIVE The present study was undertaken to explore the relationship between the characteristic geometry of aneurysms prone to rupture and the blood flow patterns therein, using microsurgically produced aneurysms that simulated human middle cerebral artery aneurysms in scale and shape. METHODS We measured in vivo velocity profiles using our 20-MHz,(More)
There is accumulating circumstantial evidence suggesting that endothelial cell dysfunction contributes to the "no-reflow" phenomenon in postischemic kidneys. Here, we demonstrated the vulnerability of in vitro, ex vivo, and in vivo endothelial cells exposed to pathophysiologically relevant insults, such as oxidative and nitrosative stress or ischemia. All(More)
The goal of this study was to evaluate microheterogeneity of myocardial blood flow and its dependence on arterial O2 tension (PaO2). We measured within-layer distribution of regional blood flows in the left ventricles of anesthetized rabbits in both normoxic and hypoxic states with myocardial region sizes in the range of 0.01-1.0 mm2. A novel method of(More)
We developed a portable needle-probe videomicroscope with a charge-coupled device (CCD) camera to visualize the subendocardial microcirculation. In 12 open-chest anesthetized pigs, the sheathed needle probe with a doughnut-shaped balloon and a microtube for flushing away the intervening blood was introduced into the left ventricle through an incision in the(More)
A high resolution laser Doppler velocimeter using an optical fiber was developed to evaluate detailed characteristics of phasic blood flow in the coronary artery. Local blood flow velocities were measured in the proximal (0.27 +/- 0.05 cm i.d.) and the distal portion (0.09 +/- 0.02 cm i.d.) of the left circumflex coronary artery of anesthetized, open-chest(More)
The interaction between monocytes and endothelial cells is considered to play a major role in the early stage of atherosclerosis, and the involved endothelial cell micromechanics may provide us with important aspects of atherogenesis. In the present study, we evaluated (i) the endothelial cell-to-cell and cell-to-substrate gaps with the electric(More)
STUDY OBJECTIVE The aim was to clarify the characteristics of the phasic blood velocity pattern and their possible causes in left ventricular hypertrophy secondary to systemic hypertension. DESIGN Measurements of blood velocities in the left anterior descending coronary artery were made with a 20 MHz Doppler catheter with a top mounted annular crystal.(More)
BACKGROUND A noninvasive technique to monitor renal microcirculation would be a useful tool for investigation of renal disease and the effects of drugs on the renal system. We have developed a novel, less invasive technique to visualize renal microcirculation in vivo using an intravital tapered-tip (1 mm phi) lens-probe (pencil lens-probe) videomicroscopy,(More)
Intra-aortic measurement of nitric oxide (NO) would provide valuable insights into NO bioavailability in systemic circulation and vascular endothelial function. In the present study, we thus developed a catheter-type NO sensor to measure intra-aortic NO concentration in vivo. An NO sensor was encased and fixed in a 4-Fr catheter. The sensor was then located(More)
BACKGROUND The phase difference of coronary arterial and venous flows indicates the importance of intramyocardial capacitance vessels in storing diastolic flow and in discharging volume in systole. However, the anatomic and functional characteristics of the capacitance vessels are unclear. We aimed to clarify those characteristics with their transmural(More)