Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Motoyasu Ishii is active.

Publication


Featured researches published by Motoyasu Ishii.


The American Journal of Gastroenterology | 2000

Simultaneous measurements of serum α-fetoprotein and protein induced by vitamin K absence for detecting hepatocellular carcinoma

Motoyasu Ishii; Hiroko Gama; Nobuyuki Chida; Yoshiyuki Ueno; Haruhide Shinzawa; Tooru Takagi; Takayoshi Toyota; Tsuneo Takahashi; Reiji Kasukawa

Simultaneous measurements of serum α-fetoprotein and protein induced by vitamin K absence for detecting hepatocellular carcinoma


The American Journal of Gastroenterology | 2000

Simultaneous measurements of serum alpha-fetoprotein and protein induced by vitamin K absence for detecting hepatocellular carcinoma. South Tohoku District Study Group.

Motoyasu Ishii; Hiroko Gama; Nobuyuki Chida; Yoshiyuki Ueno; Haruhide Shinzawa; Takagi T; Takayoshi Toyota; Tsuneo Takahashi; Reiji Kasukawa

OBJECTIVE:We evaluated the measurements of serum α-fetoprotein (AFP) and the protein induced by vitamin K absence (PIVKA-II) in 734 patients with chronic hepatitis (CH) and liver cirrhosis (LC) who had been followed-up for the development of hepatocellular carcinoma (HCC).METHODS:Serum AFP and PIVKA-II were measured every month and abdominal ultrasonography was performed every 3 months. Youdens index (sensitivity + specificity −1) was calculated.RESULTS:On an average follow-up period of 374.5 days, HCC was detected in three HBsAg-positive LC patients (10.0%/yr), four anti-HCV-positive CH patients (1.35%/yr), 21 anti-HCV-positive LC patients (7.8%/yr), and one patient with both HBsAg- and anti-HCV-positive LC (22.7%/yr). At the time of HCC detection, the size of HCC was 4.7 ± 0.6 (mean ± SD) cm in HBsAg-positive patients and 2.4 ± 1.3 cm in anti-HCV-positive patents. Cut-off values of 20 ng/ml for AFP (Youdens index = 0.422) and 60 mAU/ml for PIVKA-II (Youdens index = 0.316) gave the highest index for each marker. When these two markers were combined, cut-off values of 40 ng/ml for AFP and 80 mAU/ml for PIVKA-II gave the highest index (Youdens index = 0.500, sensitivity = 65.5%, specificity = 85.5%, positive predictable value = 14.8%, negative predictable value = 98.3%). The levels of AFP or PIVKA-II increased within three months before the detection of HCC.CONCLUSIONS:Simultaneous measurements of serum AFP and PIVKA-II levels that are performed every 3 months are useful for detecting a developing HCC. The optimal cut-off values for AFP and PIVKA-II may be 40 ng/ml and 80 mAU/ml, respectively.


Journal of Gastroenterology | 1994

Small duct cholangitis induced byn-formyll-methioninel-leucinel-tyrosine in rats

Shinji Yamada; Motoyasu Ishii; Liu Shi Liang; T. Yamamoto; Takayoshi Toyota

Primary sclerosing cholangitis (PSC) frequently accompanies inflammatory bowel diseases. In an attempt to increase our understanding of the pathogenesis of PSC, we studied bile duct changes in rats with colitis which had been givenn-formyll-methioninel-leucinel-tyrosine (fMLT) rectally; fMLT is one of the chemotactic peptides produced byEscherichia coli, and is secreted into the bile by hepatocytes after it enters the portal blood. Transrectal administration of fMLT induced a marked inflammation in the portal triad and mild hepatocyte necrosis on the 4th day. The infiltrating leukocytes in the portal tract were mostly mononuclear cells, which densely infiltrated around the bile ducts. These mononuclear cells appeared to attach to bile duct epithelial cells, and they were more numerous in the smaller bile ducts. Electron microscopy revealed that lymphocytes were in direct contact with bile duct lining cells and that some epithelial cells had degenerated or collapsed. These results suggest that thisE. coli-derived peptide may induce cholangitis in the small bile duct through cell-mediated mechanisms. Since these pathologic changes resemble those of the bile duct observed in the early stage of PSC, it can be concluded that bacterial chemotactic peptides may play a role in the pathogenesis of small-duct PSC.


In Vitro Cellular & Developmental Biology – Animal | 1998

PRIMARY CULTURE OF CHOLANGIOCYTES FROM NORMAL MOUSE LIVER

Kaichiro Yahagi; Motoyasu Ishii; Koju Kobayashi; Yoshiyuki Ueno; Yutaka Mano; Hirofumi Niitsuma; Takehiko Igarashi; Takayoshi Toyota

Dear Editor: Cholangiocytes have been thought to play a role as antigen presenting cells or target cells in immune-mediated cholangitis. The aberrant expression of MHC class II proteins on cholangiocytes in primary biliary cirrhosis raises the possibility that cholangiocytes can function as antigen presenting ceils and, in immune-mediated cholangitis, cholangiocytes appeared to be targeted by lymphocytes (8). To explore the immune mechanisms underlying cholangitis, a culture of mouse cholangiocytes is essential, because the mouse is indispensable for immunological study. Cholangiocytes are a minor component of liver ceils, comprising only 3-4% of the rodent liver cells. Most extensively studied cultured


Acta Radiologica | 1998

HEPATOCELLULAR CARCINOMAS SUPPLIED BY INFERIOR PHRENIC ARTERIES

N. Tanabe; Takao Iwasaki; Nobuyuki Chida; Takehiro Akahane; Nao Kobayashi; Motoyasu Ishii; Takayoshi Toyota

Purpose: To assess the arterial supply to hepatocellular carcinomas (HCCs) by inferior phrenic arteries (IPA). Material and Methods: A total of 126 consecutive cases of HCC were studied by contrast-enhanced CT and conventional arteriography. Blood supply from an IPA was suspected when the size of the HCC mass as seen on contrast-enhanced CT did not match the size of the tumor mass as seen on hepatic arteriography. Inferior phrenic arteriography was employed to confirm these findings. HCCs fed by the IPA were analyzed in terms of size, location, and history of prior treatment. Results: In 14 (11%) of the 126 cases, the tumor was found to have a blood supply from an IPA. Eleven of these tumors were located in segments 2 and 7. Three tumors, which had not been treated previously, had a blood supply from an IPA. Six tumors were almost exclusively fed by an IPA and were located in segments 7, 1, and 4. Conclusion: HCCs located in segments which form the bare area of the liver (S1, S2, S7) can be supplied by an IPA. This should be suspected when a lesion or part of a lesion is identified on contrast-enhanced CT but not on hepatic arteriography.


The Journal of Infectious Diseases | 2010

Hepatitis B Virus Replication Could Enhance Regulatory T Cell Activity by Producing Soluble Heat Shock Protein 60 From Hepatocytes

Yasuteru Kondo; Yoshiyuki Ueno; Koju Kobayashi; Eiji Kakazu; Masaaki Shiina; Jun Inoue; Keiichi Tamai; Yuta Wakui; Yasuhito Tanaka; Masashi Ninomiya; Noriyuki Obara; Koji Fukushima; Motoyasu Ishii; Tomoo Kobayashi; Hirofumi Niitsuma; Satonori Kon; Tooru Shimosegawa

BACKGROUND HBcAg-specific regulatory T (T(reg)) cells play an important role in the pathogenesis of chronic hepatitis B. Soluble heat shock proteins, especially soluble heat shock protein 60 (sHSP60), could affect the function of T(reg) cells via Toll-like receptor. METHODS We analyzed the relationship between soluble heat shock protein production and hepatitis B virus (HBV) replication with both clinical samples from HBeAg-positive patients with chronic hepatitis B (n= 24) and HBeAb-positive patients with chronic hepatitis B (n= 24) and in vitro HBV-replicating hepatocytes. Thereafter, we examined the biological effects of sHSP60 with isolated T(reg) cells. RESULTS The serum levels of sHSP60 in patients with chronic hepatitis B were statistically significantly higher than those in patients with chronic hepatitis C (P<.01), and the levels of sHSP60 were correlated with the HBV DNA levels (r = 0.532; P<.001) but not with the alanine aminotransferase levels. Moreover, the levels of sHSP60 in HBV-replicating HepG2 cells were statistically significantly higher than those in control HepG2 cells. Preincubation of CD4(+) CD25(+) cells with recombinant HSP60 (1 ng/mL) statistically significantly increased the frequency of HBcAg-specific interleukin 10-secreting T(reg) cells. The frequency of IL7R(-)CD4(+)CD25(+) cells, the expression of Toll-like receptor 2, and the suppressive function of T(reg) cells had declined during entecavir treatment. CONCLUSION The function of HBcAg-specific T(reg) cells was enhanced by sHSP60 produced from HBV-infected hepatocytes. Entecavir treatment suppressed the frequency and function of T(reg) cells; this might contribute to the persistence of HBV infection.


Gastroenterology | 1991

Regional orientation of actin filaments in the pericanalicular cytoplasm of rat hepatocytes

Motoyasu Ishii; Hiroshi Washioka; Akira Tonosaki; Takayoshi Toyota

To elucidate how actin filaments participate in bile formation, polarity of actin filaments in the pericanalicular cytoplasm was determined with myosin subfragment 1 by transmission electron microscopy of ultrathin sections and deep-etching replicas. Densely concentrated actin filaments were identified around the bile canaliculi in the forms of microvillous core filaments, pericanalicular web filaments, and filaments on the junctional complex. They bound subfragment 1 to form double-helical strands on the deep-etching replica or typical arrowheads on the ultrathin section. All microvillous core filaments showed their arrowheads pointing basally, suggesting the molecular growth occurring at their apical ends. In contrast, filaments of the pericanalicular web, running in parallel to the cell surface, showed unfixed polarities as indicated by their arrowheads. Furthermore, neighboring filament pairs often showed opposite polarities, an alignment necessary for filament sliding. The junctional complex had filaments with arrowheads pointed mostly at the cell center with a small number in opposite direction. In addition, a group of sporadic filaments appeared to be installed to link to both the canalicular membrane and coated vesicles. Such regionally specialized actin filaments are considered inclusively to form a cytoskeletal system that is in charge of (a) maintenance of length of the microvilli, (b) contraction of the canalicular walls, and (c) translocation of coated vesicles in the pericanalicular cytoplasm.


Journal of Gastroenterology | 1998

Profiles of cytokines produced by CD4-positive T lymphocytes stimulated by anti-CD3 antibody in patients with chronic hepatitis C

Koju Kobayashi; Motoyasu Ishii; Takehiko Igarashi; Toshihiro Satoh; Yutaka Miyazaki; Yoshiaki Yajima; Katsuaki Ukai; Hiroshi Suzuki; Atushi Kanno; Yoshiyuki Ueno; Toshihiko Miura; Takayoshi Toyota

Abstract: Helper T cells (Th) are classified as type 1 (Th1) and type 2 (Th2) according to the cytokines they produce; interferon-γ is produced by Th1, and interleukin-4 by Th2. We counted the circulating CD4-positive Th cells that produce interferon-γ or interleukin-4 with an enzyme-linked immunospot assay. CD4-positive T cells isolated from patients with chronic hepatitis B (n = 10), chronic hepatitis C (n = 16), and healthy subjects (n = 10) were stimulated with anti-CD3 antibody in vitro. The number of interferon-γ-producing Th cells was significantly lower in patients with chronic hepatitis C than in healthy subjects (P = 0.0024), whereas in patients with chronic hepatitis B, the number was similar to that in healthy subjects (P = 0.8530). The number of interleukin-4-producing Th cells was significantly higher in patients with chronic hepatitis C (P = 0.0010) and chronic hepatitis B (P = 0.0089) than in healthy subjects. In chronic hepatitis C, the number of interferon-γ-producing Th cells was increased after incubation of the cells with interferon-α (P = 0.008) or with recombinant interferon-γla (P = 0.024), but not with interferon-β (P = 0.051). The number of interleukin-4-producing Th cells was decreased after incubation with interferon-α (P = 0.0004), with interferon-β (P = 0.003), and with recombinant interferon-γla (P = 0.0004). Changes in the numbers of interferon-γ- or interleukin-4-producing Th cells in vitro were more evident in sustained responders to interferon therapy than in non-responders. These results suggest that Th2 cells are the predominant cell type in chronic hepatitis C, and that their activity may be suppressed by the administration of interferon.


PLOS ONE | 2013

1(OH) Vitamin D3 Supplementation Improves the Sensitivity of the Immune-Response during Peg-IFN/RBV Therapy in Chronic Hepatitis C Patients-Case Controlled Trial

Yasuteru Kondo; Takanobu Kato; Osamu Kimura; Tomoaki Iwata; Masashi Ninomiya; Eiji Kakazu; Masahito Miura; Takehiro Akahane; Yutaka Miyazaki; Tomoo Kobayashi; Motoyasu Ishii; Norihiro Kisara; Kumiko Sasaki; Haruo Nakayama; Takehiko Igarashi; Noriyuki Obara; Yoshiyuki Ueno; Tatsuki Morosawa; Tooru Shimosegawa

Objective 1,25(OH)2 vitamin D3 can affect immune cells. However, the mechanism responsible for the favorable effects of 1(OH) vitamin D3, which becomes 1,25(OH)2 vitamin D3 in the liver, is not clear. The aim of this study is to analyze the immunological response of 1(OH) vitamin D3 supplementation in CH-C patients. Design Forty-two CH-C patients were treated with 1(OH) vitamin D3/Peg-IFNα/RBV. Forty-two case-matched controls were treated with Peg-IFNα/RBV. The expression of Interferon-stimulated genes (ISGs)-mRNA in the liver biopsy samples and JFH-1 replicating Huh-7 cells were quantified by real-time PCR. Ten kinds of cytokines in the plasma were quantified during treatment by using a suspension beads array. A trans-well co-culture system with peripheral blood mononuclear cells (PBMCs) and Huh-7 cells was used to analyze the effect of 1(OH) vitamin D3. The activities of the Th1 response were compared between subjects treated with 1(OH) vitamin D3/Peg-IFN/RBV and those treated with Peg-IFN/RBV therapy alone. Results 1(OH) vitamin D3/Peg-IFN/RBV treatment could induce rapid viral reduction, especially in IL28B T/T polymorphism. Several kinds of cytokines including IP-10 were significantly decreased after 4 weeks of 1(OH) vitamin D3 treatment (p<0.05). Th1 responses in the subjects treated with 1(OH) vitamin D3/Peg-IFN/RBV were significantly higher than those treated with Peg-IFN/RBV at 12 weeks after Peg-IFN/RBV therapy (p<0.05). The expression of ISGs in the patient’s liver biopsy samples was significantly lower than in those treated without 1(OH) vitamin D3 (p<0.05). Conclusion 1(OH) vitamin D3 could improve the sensitivity of Peg-IFN/RBV therapy on HCV-infected hepatocytes by reducing the IP-10 production from PBMCs and ISGs expression in the liver.


Hepatology Research | 2000

Genoepidemiology and its relationship to clinical features in patients infected chronically with hepatitis B virus (HBV)

Kumiko Kikuchi; Hirofumi Niitsuma; Motoyasu Ishii; Julieta G. Cervantes; Shang Hong; Toshiaki Ojima; Chiaki Suzuki; Tomoo Kobayashi; Yoshiyuki Ueno; Koju Kobayashi; Tooru Shimosegawa; Takayoshi Toyota

The route of hepatitis B virus (HBV) infection and subsequent clinical course vary widely. It is not clear if the prevalence of HBV genotypes differs in the different clinical features of HBV carriers. The genotype of HBV was determined by direct sequencing of HBV DNA amplified with a PCR method from 310 Japanese HBV carriers (189 male and 121 female, aged from 14 to 82 years). Genotype A was detected in eight (2.6%) of 310 HBV carriers, genotype B was detected in 92 (29.7%) and genotype C was detected in 210 (67.7%). None of them had genotype D, E or F. Among the eight patients infected with genotype A, one patient had been infected with HBV in his adulthood. Furthermore, both of one married couple also had genotype A. On the other hand, a HBeAg-negative state and HBeAg-negative healthy carrier state were significantly more common in patients infected with genotype B than those with genotype C by univariate analysis (P<0.0001 and 0.0058) and multiple logistic regression (P<0.0001 and 0.0029). Hepatocellular carcinoma was present in two of eight patients with genotype A, 11 of 210 patients with genotype C and none of the 92 patients with genotype B. These results suggest that the genotype of HBV may be a determinant of the outcome after acute HBV infection and of chronic HBV infection.

Collaboration


Dive into the Motoyasu Ishii's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge