Publications by authors named "Takafumi Kurokawa"

Introduction: Cell therapy using adipose-derived mesenchymal stem cells (ASCs) is a promising avenue of regenerative medicine for the treatment of various diseases. It has been considered that ASCs exert their therapeutic effects through the secretion of multiple factors that are critical for tissue remodeling or the suppression of inflammation. Recently, conditioned medium (CM) from ASCs that contains a complex of secreted factors has received attention as a cost-effective alternative to cell therapy.

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Radiographic findings in several atypical cases of postaxial polydactyly of the foot do not provide sufficient information to assess the cartilaginous structures or duplicated digit connections at the MTP joint. The purpose of this study was to demonstrate the surgical procedures using arthrography for the cartilaginous structures of the MTP joint in postaxial polydactyly of the foot. We performed arthrography in 7 feet of 7 patients with postaxial polydactyly of the foot in which duplication of the proximal phalanx was observed at the fifth MTP joint on the basis of radiographic evaluation.

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Purpose: From the correlation between the blood flow dynamics and wall dynamics in the left ventriocle (LV) analyzed using echo-dynamography, the ejection mechanisms and role of the intra-ventricular vortex in the LV were elucidated in detail during the pre-ejection transitional period (pre-ETP), the very short period preceding LV ejection.

Methods: The study included 10 healthy volunteers. Flow structure was analyzed using echo-dynamography, and LV wall dynamics were measured using both high-frame-rate two-dimensional echocardiography and a phase difference tracking method we developed.

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Surgical intervention for aortic valve stenosis (AS) has been established; however its diagnosis based on echocardiographic assessment is still limited by aortic valvular velocity, aortic valvular pressure gradients, and color Doppler imaging. Echo-dynamography (EDG) is a method to determine intracardiac flow dynamics, such as two-dimensional blood flow velocity, vortex, and dynamic pressure. These flow dynamics may be influenced by left ventricular (LV) wall motion and the resistance in LV outflow caused by AS.

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Background: Although the deformability of the left ventricular (LV) wall appears to be important in maintaining effective cardiac performance, this has not been debated by anyone, probably owing to the difficulties of the investigation.

Objectives: This study applies a new technology to demonstrate how the LV wall deforms so as to adjust for optimum cardiac performance.

Subjects And Methods: Ten healthy volunteers were the subjects.

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Objective: We attempted to disclose the microscopic characteristics of the non-uniform distribution of the contraction and extension (C-E) of the left ventricular (LV) myocardium using a new methodology (echo-dynamography).

Methods: The distributions of the "axial strain rate" (aSR) and the intra-mural velocity in the local areas of the free wall including the posterior wall (PW) and interventricular septum (IVS) were microscopically obtained using echo-dynamography with a high accuracy of 821 μm in the spatial resolution. The results were shown by the color M-mode echocardiogram or curvilinear graph.

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Objectives: Using newly developed ultrasonic technology, we attempted to disclose the characteristics of the left ventricular (LV) contraction-extension (C-E) property, which has an important relationship to LV function.

Methods: Strain rate (SR) distribution within the posterior wall and interventricular septum was microscopically measured with a high accuracy of 821μm in spatial resolution by using the phase difference tracking method. The subjects were 10 healthy men (aged 30-50 years).

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Echo-Dynamography (EDG) is a smart visualization technique in echocardiography in which two-dimensional distribution of blood flow vectors in cardiovascular system is deduced by applying fluid dynamics theories into Doppler velocity datasets. Previous validation studies such as numerical simulation of free jet model or model circulation were too simple to reproduce unstable and asymmetrical flow in left ventricle. In the present study, virtual color Doppler echocardiography is generated from PC-MRA (phase contrast magnetic resonance angiography) datasets.

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Echo-dynamography (EDG) is a method for visualizing left ventricular (LV) blood flow based on cardiac Doppler measurement in which blood flow component perpendicular to the ultrasonic beam is deduced by applying fluid dynamics theories to two-dimensional (2D) distribution of blood flow component along the ultrasonic beam. EDG has been validated by numerical simulation and particle image velocimetry of model circulation. However, these validations were too simple to reproduce unstable and asymmetrical flow in a beating heart.

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