Biomedical subjects

Yasuaki Takeyama

Publications and source records attributed to Yasuaki Takeyama.

4 recordsLinked to original sources

PubMed2006

Postoperative recurrence in hepatocellular carcinoma: Comparison between percutaneous ethanol injection and radiofrequency ablation.

AIM: Recently percutaneous ethanol injection (PEI) turned into percutaneous radiofrequency ablation (PRFA), and it has become widely used for the treatment of hepatocellular carcinoma (HCC). The present study was to compare the incidence in postoperative HCC recurrence between these two therapeutic approaches. METHODS: One hundred and sixty-eight first-time HCC in patient cases were chosen for PEI (n=94) and PRFA (n=74). The localized recurrence rate based on the operator's experience in percutaneous treatment for HCC (on <5 years versus >/=5 years experience) was examined. RESULTS: The PRFA group demonstrated a significantly lower localized recurrence rate within 2 years than the PEI group (8% and 22%, respectively, P<0.01). The local recurrence rate of HCC within 2 years after PEI was significantly lower in those for whom the operator's experience was more than 5 years compared to those for whom it was less than 5 years (12% versus 24%, respectively, P<0.05). In contrast, after PRFA there was no significant difference between these two groups of <5 years and of >/=5 years experience (8% versus 8%, respectively, P=0.98). CONCLUSION: The present study demonstrated that PRFA resulted in a lower rate of local recurrence in comparison to conventional PEI, regardless of the operator's experience.

Journal Article↗

PubMed2006

Altered expression of alkaline phosphatase (ALP) in the liver of primary biliary cirrhosis (PBC) patients.

Serum alkaline phosphatase (ALP) is a representative marker of cholestasis, in diseases such as primary biliary cirrhosis (PBC). However, the hepatic localization of ALP in patients with cholestatic liver diseases has not been fully clarified. Accordingly, we studied the expression of ALP in the liver of PBC, chronic hepatitis C and controls. By immunohistochemistry, in the liver tissue of controls and chronic hepatitis C patients, ALP was found to be localized in the canalicular membrane of hepatocytes and the apical area of the cytoplasm of bile duct epithelial cells. In PBC, ALP was localized in both the canalicular and baso-lateral membranes of hepatocytes and in the whole cytoplasm of the remaining bile duct epithelial cells. The expression of ALP in liver tissues evaluated by Western blotting was increased to 3.6-fold in PBC compared with that in the controls and chronic hepatitis C patients, while the expression of mRNA of ALP evaluated by RT-PCR was increased to 7.0-fold in PBC compared with that in the controls and chronic hepatitis C patients. The present study is the first study to reveal altered localization and increased expression of ALP which may result in the elevation of serum ALP in PBC.

Journal Article↗

PubMed2004

Multidrug resistance-associated protein 4 is up-regulated in liver but down-regulated in kidney in obstructive cholestasis in the rat.

BACKGROUND/AIMS: Multidrug resistance-associated protein 4 (Mrp4, ABCC4) transports cyclic nucleotides, anti-retroviral compounds, and sulfated bile acids. Mrp4 expression is increased in farnesyl/bile acid receptor knockout mice. Our aim was to investigate Mrp4 expression and function in rat liver and kidney in obstructive cholestasis. METHODS: Male Sprague-Dawley rats were subjected to bile duct ligation (BDL) or sham-surgery. Animals were sacrificed after 3, 7, and 14 days and tissues were harvested for Western blot analysis, real-time reverse transcriptase-mediated polymerase chain reaction (RT-PCR), and immunohistochemistry. RESULTS: Western blot analysis revealed a progressive, more than seven-fold increase (P < 0.05) of Mrp4 expression in cholestatic livers, 14 days after BDL. In contrast, Mrp4 in 14-day BDL kidneys decreased to 26+/-4% of controls (P < 0.005). Immunohistochemistry localized Mrp4 to the basolateral hepatocyte membrane and corroborated its hepatic up-regulation after BDL. Real-time RT-PCR demonstrated no major changes of Mrp4 mRNA levels in liver and kidney after BDL. Cyclic adenosine monophosphate, an MRP4 substrate, was increased in plasma and urine, consistent with these findings. CONCLUSIONS: Obstructive cholestasis in rats results in progressive up-regulation of Mrp4 protein in liver but down-regulation in kidney. The absence of corresponding changes in Mrp4 mRNA suggests posttranscriptional mechanisms as predominant regulators of Mrp4 expression in BDL rats.

Animals↗

PubMed2002

[Assessing liver function by magnetic resonance imaging two-dimensional phase-shift flow measurement of portal venous blood flow after oral intake of glucose].

We have already reported that the ratio of portal venous flow 30 min after oral intake of glucose 75 g to that before intake (PVFR30), measured using pulsed-Doppler ultrasonography (US), correlated significantly with other indicators of liver function and that it could be used to estimate hepatic function before surgery, including liver resection. In this study, to assess the disadvantages of pulsed-Doppler ultrasonography, PVFR30 was measured using two-dimensional (2D) phase-shift (PS) magnetic resonance imaging (MRI). PVFR30 was measured in 17 patients and 7 volunteers: 13 with liver cirrhosis (LC) and 11 without LC (non-LC). Portal venous flow could be measured in all patients without any disturbance of intestinal gas or patient fat, or the high degree of technical skill that Doppler US requires. PVFR30 was significantly lower in the LC group than in the non-LC group. In addition, it correlated significantly with other indicators of liver function, including the indocyanine green clearance test, prothrombin time, hepaplastin test, and cholinesterase activity. These results suggest that PVFR30 measured by 2D PS MRI can be used to estimate liver function, and that this MRI method can be performed more easily than pulsed-Doppler US.

Administration, Oral↗