scholarly journals Measurement of Volumetric Mitral and Aortic Blood Flow Based on a New Freehand Three-dimensional Colour Flow Imaging Method. An in vivo Validation

2000 ◽  
Vol 1 (3) ◽  
pp. 204-212 ◽  
Author(s):  
B Haugen
Keyword(s):  
Blood Flow ◽  
Three Dimensional ◽  
Imaging Method ◽  
Flow Imaging ◽  
Aortic Blood Flow ◽  
Aortic Blood ◽  
Colour Flow ◽  
In Vivo Validation

scholarly journals High-speed volumetric two-photon fluorescence imaging of neurovascular dynamics

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiang Lan Fan ◽  
Jose A. Rivera ◽  
Wei Sun ◽  
John Peterson ◽  
Henry Haeberle ◽  
...  
Keyword(s):  
Blood Flow ◽  
High Speed ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Microscopy ◽  
Fluorescence Signal ◽  
Imaging Method ◽  
Spatiotemporal Resolution ◽  
Two Photon

AbstractUnderstanding the structure and function of vasculature in the brain requires us to monitor distributed hemodynamics at high spatial and temporal resolution in three-dimensional (3D) volumes in vivo. Currently, a volumetric vasculature imaging method with sub-capillary spatial resolution and blood flow-resolving speed is lacking. Here, using two-photon laser scanning microscopy (TPLSM) with an axially extended Bessel focus, we capture volumetric hemodynamics in the awake mouse brain at a spatiotemporal resolution sufficient for measuring capillary size and blood flow. With Bessel TPLSM, the fluorescence signal of a vessel becomes proportional to its size, which enables convenient intensity-based analysis of vessel dilation and constriction dynamics in large volumes. We observe entrainment of vasodilation and vasoconstriction with pupil diameter and measure 3D blood flow at 99 volumes/second. Demonstrating high-throughput monitoring of hemodynamics in the awake brain, we expect Bessel TPLSM to make broad impacts on neurovasculature research.

S-nitroso-albumin carries a thiol-labile pool of nitric oxide, which causes venodilation in the rat

2005 ◽  
Vol 289 (2) ◽  
pp. H916-H923 ◽  
Author(s):  
Nelson N. Orie ◽  
Patrick Vallance ◽  
Dean P. Jones ◽  
Kevin P. Moore
Keyword(s):  
Nitric Oxide ◽  
Molecular Weight ◽  
Blood Flow ◽  
Vascular Function ◽  
Low Molecular Weight ◽  
Aortic Blood Flow ◽  
Hemodynamic Effects ◽  
Rapid Decomposition ◽  
Aortic Blood

It is now established that S-nitroso-albumin (SNO-albumin) circulates at low nanomolar concentrations under physiological conditions, but concentrations may increase to micromolar levels during disease states (e.g., cirrhosis or endotoxemia). This study tested the hypothesis that high concentrations of SNO-albumin observed in some diseases modulate vascular function and that it acts as a stable reservoir of nitric oxide (NO), releasing this molecule when the concentrations of low-molecular-weight thiols are increased. SNO-albumin was infused into rats to increase the plasma concentration from <50 nmol/l to ∼4 μmol/l. This caused a 29 ± 6% drop in blood pressure, 20 ± 4% decrease in aortic blood flow, and a 25 ± 14% reduction of renal blood flow within 10 min. These observations were in striking contrast to those of an infused arterial vasodilator (hydralazine), which increased aortic blood flow, and suggested that SNO-albumin acts primarily as a venodilator in vivo. This was confirmed by the observations that glyceryl trinitrate (a venodilator) led to similar hemodynamic changes and that the hemodynamic effects of SNO-albumin are reversed by infusion of colloid. Infusion of N-acetylcysteine into animals with artificially elevated plasma SNO-albumin concentrations led to the rapid decomposition of SNO-albumin in vivo and reproduced the hemodynamic effects of SNO-albumin infusion. These data demonstrate that SNO-albumin acts primarily as a venodilator in vivo and represents a stable reservoir of NO that can release NO when the concentrations of low-molecular-weight thiols are elevated.

An in vivo validation of quantitative blood flow imaging in arteries and veins using magnetic resonance phase-shift techniques

1991 ◽  
Vol 12 (2) ◽  
pp. 117-126 ◽  
Author(s):  
A. C. VAN ROSSUM ◽  
M. SPRENGER ◽  
F. C. VISSER ◽  
K. H. PEELS ◽  
J. VALK ◽  
...  
Keyword(s):  
Blood Flow ◽  
Magnetic Resonance ◽  
Phase Shift ◽  
Flow Imaging ◽  
Blood Flow Imaging ◽  
Arteries And Veins ◽  
In Vivo Validation

scholarly journals Vasorelaxant and Hypotensive Effects of Jaboticaba Fruit (Myrciaria cauliflora) Extract in Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Daniela Medeiros Lobo de Andrade ◽  
Carolina de Fátima Reis ◽  
Patrícia Ferreira da Silva Castro ◽  
Leonardo Luiz Borges ◽  
Nathalia Oda Amaral ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Femoral Vein ◽  
Soluble Guanylyl Cyclase ◽  
Aortic Blood Flow ◽  
Aortic Blood ◽  
Cox Inhibitor

This study’s aim was to determine the effect of hydroalcoholic extract ofM. cauliflora(HEMC) on vascular tension and blood pressure in rats. In ourin vitrostudies using precontracted isolated aortas from rats, HEMC and acetylcholine (positive control) induced relaxation only in vessels with endothelium. Pretreatment with L-NAME (NO synthase inhibitor) or ODQ (soluble guanylyl cyclase (sGC) inhibitor) abolished the HEMC-induced relaxation. The treatment with MDL-12,330A (adenylyl cyclase (AC) inhibitor) or diclofenac (COX inhibitor) reduced HEMC-induced vasorelaxation. The blockade of muscarinic andβ-adrenergic receptors (by atropine and propranolol, resp.) did not promote changes in HEMC-induced vasorelaxation. In ourin vivostudies, catheters were inserted into the right femoral vein and artery of anesthetized rats for HEMC infusion and the measurement of blood pressure, heart rate, and aortic blood flow. The intravenous infusion of HEMC produced hypotension and increased aortic blood flow with no changes in heart rate. These findings showed that HEMC induces endothelium-dependent vascular relaxation and hypotension with no alteration in heart rate. The NO/sGC/cGMP pathway seems to be the main cellular route involved in the vascular responsiveness.

scholarly journals Non-contact scanning diffuse correlation tomography system for three-dimensional blood flow imaging in a murine bone graft model

2015 ◽  
Vol 6 (7) ◽  
pp. 2695 ◽  
Author(s):  
Songfeng Han ◽  
Johannes Johansson ◽  
Miguel Mireles ◽  
Ashley R. Proctor ◽  
Michael D. Hoffman ◽  
...  
Keyword(s):  
Blood Flow ◽  
Bone Graft ◽  
Three Dimensional ◽  
Flow Imaging ◽  
Blood Flow Imaging ◽  
Tomography System

COMPUTATIONS OF PULSATILE AORTIC BLOOD FLOW PROBLEMS ON PARALLEL COMPUTERS

2003 ◽  
Vol 15 (03) ◽  
pp. 109-114
Author(s):  
YANG-YAO NIU ◽  
SHOU-CHENG TCHENG
Keyword(s):  
Blood Flow ◽  
Stokes Equations ◽  
Computing Time ◽  
Time Integration ◽  
Parallel Computer ◽  
Aortic Blood Flow ◽  
Pc Cluster ◽  
Flow Problems ◽  
Aortic Blood ◽  
Speed Up

In this study, a parallel computing technology is applied on the simulation of aortic blood flow problems. A third-order upwind flux extrapolation with a dual-time integration method based on artificial compressibility solver is used to solve the Navier-Stokes equations. The original FORTRAN code is converted to the MPI code and tested on a 64-CPU IBM SP2 parallel computer and a 32-node PC Cluster. The test results show that a significant reduction of computing time in running the model and a super-linear speed up rate is achieved up to 32 CPUs at PC cluster. The speed up rate is as high as 49 for using IBM SP2 64 processors. The test shows very promising potential of parallel processing to provide prompt simulation of the current aortic flow problems.

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