Yasuji Ryu

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Previous studies demonstrated that sphingosine-1-phosphate (S1P) induced migration of human umbilical vein endothelial cells (HUVECs) whereas it inhibited that of vascular smooth muscle cells (SMCs). This study explored the molecular mechanisms underlying the contrasting S1P actions on vascular cell motility. In rat and human aortic SMCs, the(More)
To understand the hemodynamics of hepatocellular carcinoma (HCC) is important for the precise imaging diagnosis and treatment, because there is an intense correlation between their hemodynamics and pathophysiology. Angiogenesis such as sinusoidal capillarization and unpaired arteries shows gradual increase during multi-step hepatocarcinogenesis from(More)
OBJECTIVE The aim of this study was to examine the association between ectopic fat and organ-specific insulin resistance (IR) in insulin-target organs in patients with nonalcoholic fatty liver disease (NAFLD). METHODS Organ-specific IR in the liver (hepatic glucose production (HGP) × fasting plasma insulin (FPI) and suppression of HGP by insulin [%HGP]),(More)
PURPOSE To assess the feasibility of texture analysis for classifying fibrosis stage and necroinflammatory activity grade in patients with chronic hepatitis C on T2-weighted (T2W), T1-weighted (T1W) and Gd-EOB-DTPA-enhanced hepatocyte-phase (EOB-HP) imaging. MATERIALS AND METHODS From April 2008 to June 2012, MR images from 123 patients with(More)
OBJECTIVES The objective of this study was to assess prospectively the diagnostic accuracy of computer-assisted computed tomographic colonography (CTC) in the detection of polypoid (pedunculated or sessile) and nonpolypoid neoplasms and compare the accuracy between gastroenterologists and radiologists. METHODS This nationwide multicenter prospective(More)
The modeling of tracer kinetics with use of low-temporal-resolution data is of central importance for patient dose reduction in dynamic contrast-enhanced CT (DCE-CT) study. Tracer kinetic models of the liver vary according to the physiologic assumptions imposed on the model, and they can substantially differ in the ways how the input for blood supply and(More)
Hepatic metastasis is a common cause of treatment failure following resection of pancreatic cancer. In this study, we report our results of hepatic arterial infusion (HAI) chemotherapy with gemcitabine (GEM) plus 5-fluorouracil (5-FU) or oral S-1 treatment for postoperative liver metastases from pancreatic cancer. Seven patients with postoperative liver(More)
Parametric-fitting approaches for tracer kinetic modeling depend on the capability of a computational method to describe underlying physiologic processes that cause temporal intensity changes in dynamic contrast-enhanced (DCE) images. Rapid scan techniques allow perfusion CT imaging with high temporal resolution. In clinical practice, however, the perfusion(More)
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