Y Ogura

Kyoto University, Kyoto, Kyoto-fu, Japan

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Publications (158)417.13 Total impact

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    ABSTRACT: Purpose Tissue plasminogen activator (tPA) is a fibrinolytic compound, utilized originally to treat embolic or thrombotic stroke and as an adjuvant for displacement of submacular hemorrhage. The purpose of this study is to investigate anti-angiogenic effects of tPA on experimental laser-induced choroidal neovascularization (CNV) in mice.Methods CNV was induced by laser injury in C57BL/6J mice, and intravitreal injection of tPA (4 or 40 IU/µl) or PBS was performed immediately after laser injury. Fluorescein angiography was performed 7 days after laser treatment to grade fluorescein leakage. And CNV volumes were measured by confocal evaluation of Isolectin B4 staining of RPE-choroid flatmounts. The expression of fibrin on day 3 was observed by immunostaining.Results Fluorescein leakage was inhibited by tPA in a dose-dependent manner, and a significant difference was found with tPA (40 IU/ µl) compared with PBS (p=0.02). A dose-dependent suppression of CNV volume was also observed by tPA, and there was a significant differences between tPA (40 IU/µl) (208988  52456 µm3) and PBS (386902  103060 µm3, p<0.01). The expression of fibrin was reduced in eyes treated with tPA.Conclusion Intravitreal injection of tPA reduced the expression of fibrin and significantly suppressed laser-induced CNV in mice. These findings suggested that tPA might be anti-angiogenic and have a potential as an adjuvant to anti-vascular endothelial growth factor therapy.
    Acta ophthalmologica 09/2014; 92(s253). · 2.44 Impact Factor
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    ABSTRACT: Hepatic arterial reconstruction during living donor liver transplantation (LDLT) is a very delicate and technically complicated procedure. Post-LDLT hepatic arterial complications are associated with significant morbidity and mortality.
    Clinical Transplantation 06/2014; · 1.63 Impact Factor
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    ABSTRACT: Living donor liver transplantation (LDLT) using a right liver graft with additional vein reconstructions has not been previously reported in a situs inversus (SI) patient. A 60-year-old man with SI was referred for LDLT for end-stage cirrhosis secondary to hepatitis B. The calculated regional volumes of the individual hepatic vein territories in the right liver graft suggested that the middle hepatic vein (MHV) tributaries and the inferior right hepatic veins (IRHVs) should be reconstructed in addition to the right hepatic vein (RHV). On the back-table, the recipient's recanalized umbilical vein graft was anastomosed to the V5 opening, and the other side of vein graft was anastomosed to the RHV and V8 opening to create a large single orifice. After total hepatectomy, the right liver graft was placed in the left subphrenic space at the reversed position. The common orifice of hepatic venous drainage from RHV, V8 and V5 was anastomosed to the anatomical RHV conduit of the recipient, followed by IRHV anastomosis to the inferior vena cava. Postoperative course was almost uneventful, and no vascular complications were experienced. Even for SI patients, LDLT using a right liver graft with reconstructions of the MHV tributaries and the IRHVs is feasible.
    American Journal of Transplantation 04/2014; · 6.19 Impact Factor
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    ABSTRACT: Skeletal muscle depletion, referred to as sarcopenia, predicts morbidity and mortality in patients undergoing digestive surgery. However, the impact on liver transplantation is unclear. The present study investigated the impact of sarcopenia on patients undergoing living donor liver transplantation (LDLT). Sarcopenia was assessed by a body composition analyzer in 124 adult patients undergoing LDLT between February 2008 and April 2012. The correlation of sarcopenia with other patient factors and the impact of sarcopenia on survival after LDLT were analyzed. The median ratio of preoperative skeletal muscle mass was 92% (range, 67-130%) of the standard mass. Preoperative skeletal muscle mass was significantly correlated with the branched-chain amino acids to tyrosine ratio (r = -0.254, p = 0.005) and body cell mass (r = 0.636, p < 0.001). The overall survival rate in patients with low skeletal muscle mass was significantly lower than in patients with normal/high skeletal muscle mass (p < 0.001). Perioperative nutritional therapy significantly increased overall survival in patients with low skeletal muscle mass (p = 0.009). Multivariate analysis showed that low skeletal muscle mass was an independent risk factor for death after transplantation. In conclusion, sarcopenia was closely involved with posttransplant mortality in patients undergoing LDLT. Perioperative nutritional therapy significantly improved overall survival in patients with sarcopenia.
    American Journal of Transplantation 04/2013; · 6.19 Impact Factor
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    ABSTRACT: Few studies have examined the long-term outcomes and prognostic factors associated with pediatric living living-donor liver transplantation (LDLT) using reduced and hyper-reduced left lateral segment grafts. We conducted a retrospective, single-center assessment of the outcomes of this procedure, as well as clinical factors that influenced graft and patient survival. Between September 2000 and December 2009, 49 patients (median age: 7 months, weight: 5.45 kg) underwent LDLT using reduced (partial left lateral segment; n = 5, monosegment; n = 26), or hyper-reduced (reduced monosegment grafts; n = 18) left lateral segment grafts. In all cases, the estimated graft-to-recipient body weight ratio of the left lateral segment was more than 4%, as assessed by preoperative computed tomography volumetry, and therefore further reduction was required. A hepatic artery thrombosis occurred in two patients (4.1%). Portal venous complications occurred in eight patients (16.3%). The overall patient survival rate at 1, 3 and 10 years after LDLT were 83.7%, 81.4% and 78.9%, respectively. Multivariate analysis revealed that recipient age of less than 2 months and warm ischemic time of more than 40 min affected patient survival. Pediatric LDLT using reduced and hyper-reduced left lateral segment grafts appears to be a feasible option with acceptable graft survival and vascular complication rates.
    American Journal of Transplantation 09/2012; · 6.19 Impact Factor
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    ABSTRACT: Treatment of Budd-Chiari syndrome consists of medical management, surgical shunt, transjugular intrahepatic portosystemic shunt (TIPS), and liver transplantation. Liver transplantation is indicated only when other treatments have failed. A 36-year-old Japanese man underwent living-donor liver transplantation after radiologic intervention procedures. Because of the position of the TIPS stent and the damaged vascular lesion of Budd-Chiari syndrome, a supradiaphragmatic approach was employed to achieve a safe total hepatectomy. Moreover, after resection of damaged portion of the inferior vena cava (IVC), an artificial vascular graft was utilized to fill the IVC gap. The postoperative course was uneventful; no serious complications were experienced within 2 years after liver transplantation. This supradiaphragmatic IVC approach and IVC reconstruction technique emphasized the option of surgical techniques to decrease the operative risk during liver transplantation for Budd-Chiari syndrome.
    Transplantation Proceedings 06/2011; 43(5):2093-6. · 0.95 Impact Factor
  • American Journal of Transplantation 04/2011; 11(4):869-70. · 6.19 Impact Factor
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    ABSTRACT: The goal of this study was to examine whether the lower limit of the graft-to-recipient weight ratio (GRWR) can be safely reduced to make better use of a left-lobe graft in adult-to-adult living donor liver transplantation (LDLT) in combination with portal pressure control. Beginning in December 2007, our institution actively selected left-lobe grafts for use in liver transplantation seeking to minimize the risks to healthy donors. We gradually decreased the lower limit of the GRWR to preferentially select a left-lobe over a right-lobe graft: from ≥0.7% beginning in December 2007 to ≥0.6% beginning in April 2009. A portal pressure control program, targeting final portal pressures below 15 mm Hg, was also introduced to overcome small-for-size graft problems. The ratio of left-lobe grafts among all adult-to-adult LDLT grafts and the donor complication rate (defined as Clavien grade ≥ III, excluding wound infection) were compared between two time periods: June 1999 to November 2007 (period 1, n = 541) and December 2007 to February 2010 (period 2, n = 119). Overall survival rates were also compared between those recipients of a GRWR < 0.8% and those with a GRWR ≥ 0.8% in 198 recipients who underwent LDLT at our institution between April 2006 and February 2010. Left-lobe grafts use increased from period 1 (65/541 recipients; 12.0%) to period 2 (50/119 recipients; 42.0%; P < .001). The donor complication rate tended to decrease from 13.8% in period 1 to 9.3% in period 2 (P = .115). The overall survival rate in 52 recipients with a GRWR < 0.8% did not differ from that in 146 recipients with a GRWR ≥ 0.8%. The lower limit of the GRWR can be safely reduced to 0.6% in adult-to-adult LDLT in combination with portal pressure control.
    Transplantation Proceedings 01/2011; 43(6):2391-3. · 0.95 Impact Factor
  • Journal of Hepatology - J HEPATOL. 01/2011; 54.
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    ABSTRACT: Approximately 30% of patients who have recurrent hepatitis C after liver transplantation achieve sustained virological response (SVR) by taking a combination therapy of pegylated interferon and ribavirin. For the remaining non-SVR patients, an effective management treatment has not yet been established. In this study, efficacy of long-term peginterferon maintenance therapy for non-SVR patients was evaluated. Forty patients who had previously received the combination therapy for hepatitis C after living donor liver transplantation were classified into one of the following three groups: the SVR group (n = 11); the non-SVR-IFN group (n =17), which received low-dose peginterferon maintenance therapy for non-SVR patients; and the non-SVR-Withdrawal group (n = 12), which discontinued the interferon treatment. We then compared histological changes among these three groups after 2 or more years follow-up. Activity grade of liver histology improved or remained stable in patients in the SVR and non-SVR-IFN groups, but deteriorated in half of the patients in the non-SVR-Withdrawal group. Fibrosis improved or remained stable in 10 of 11 SVR patients and in 13 of 17 non-SVR-IFN patients, but deteriorated in all non-SVR-Withdrawal patients. Mean changes in fibrosis stage between pretreatment and final liver biopsy were -0.18, +0.06 and +2.2 in the SVR, non-SVR-IFN and non-SVR-Withdrawal groups, respectively. Fibrosis stage deteriorated to F3 or F4 significantly more rapidly in the non-SVR-Withdrawal group than in the other two groups. In conclusion, continuing long-term maintenance therapy with peginterferon prevented histological progression of hepatitis C in patients who had undergone living donor liver transplantation.
    Journal of Viral Hepatitis 12/2010; 19(1):32-8. · 3.08 Impact Factor
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    ABSTRACT: Arterioportal shunts (APS) are well-known critical complications after liver transplantation (OLT). The aims of this study were to assess the frequency and causes of APS after OLT and to analyze APS patients with poor outcomes. We evaluated 1415 OLT recipients retrospectively investigating APS cases. APS were detected in at least 9 patients (0.6%). All patients with APS had a history of posttransplant invasive procedures; percutaneous transhepatic cholangio drainage (n = 6) or needle biopsy (LNB; n = 3). Two patients with poor outcomes showed proximal APS caused by LNBs. The other 7 patients with distal APSs, showed stable conditions. Imaging findings in the 2 proximal APS patients revealed drastic changes in graft hemodynamics. Although they finally underwent re-OLT, their outcomes were poor, owing to fatal complications associated with advanced collaterals. We concluded that even careful LNBs can cause APS at unexpected points. Earlier, more aggressive treatments are required, especially for proximal APS patients.
    Transplantation Proceedings 09/2010; 42(7):2642-4. · 0.95 Impact Factor
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    ABSTRACT: Herpes simplex virus (HSV) hepatitis has a fatal impact on the outcome of organ transplanted recipients. Here, we present a thought-provoking case of HSV hepatitis in a high-risk recipient after living-related liver transplantation (LRLT). A 1-month-old female newborn infant was affected by HSV encephalitis. Fulminant hepatic failure (FHF) of unknown etiology occurred suddenly at 4.4 years of age. Viral infections were ruled out as the cause of FHF. Intensive care including plasma exchange (PE) was started, and the preoperative treatments for ABO incompatibility were performed. Thereafter, LRLT was performed emergently. Although strong immunosuppression for ABO incompatibility was continued after LRLT, antibody-mediated rejection (AMR) occurred on postoperative day (POD) 4. PE was repeated and improvements were obtained. However, liver dysfunction appeared on POD 8. Histopathological findings of liver needle biopsy clearly revealed HSV hepatitis, although the results of HSV DNA and antibody titer in blood sample did not clearly indicate HSV infection. On POD 21, thrombotic microangiopathy (TMA) occurred and the plasma and immunoglobulin were replenished. Our pediatric recipient recovered successfully from AMR, HSV hepatitis, TMA, and repeated sepsis. We conclude that well considered therapy based on the real-time detection of HSV hepatitis is indispensable for the further improvements of outcome in HSV hepatitis after LRLT.
    Transplant Infectious Disease 08/2010; 12(4):353-7. · 1.98 Impact Factor
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    American Journal of Transplantation 08/2010; 10(8):1951-2. · 6.19 Impact Factor
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    ABSTRACT: A 55-year-old woman underwent living-donor liver transplantation (LDLT). She had no history of autoimmune diseases. Spleen was preserved. Steroids were withdrawn at 3 months after LDLT. Epstein-Barr virus (EBV) infection occurred at 3.5 years after LDLT. Recurrent hepatitis C virus infection was confirmed at 4.5 years after LDLT, and pegylated interferon was introduced. Diagnosis of EBV-positive post-transplant lymphoproliferative disorder (PTLD) was made at 4.8 years after LDLT, and tacrolimus (Tac) was stopped completely. Then, unconsciousness, convulsion, and cervical stiffness appeared suddenly. Electroencephalography, cerebrospinal fluid analysis, and image studies revealed normal or only nonspecific findings. The patient was in a state of exhaustion; therefore, steroid pulse therapy (SPT) was attempted. Surprisingly, her general condition, including consciousness disturbance, was improved markedly, and Hashimoto's encephalopathy (HE) was suspected, based on this reaction to SPT. Elevations of anti-thyroglobulin antibody and anti-thyroid peroxidase antibody were confirmed. After withdrawal of Tac, and treatment with acyclovir and steroids, EBV-positive PTLD and HE improved, although they recurred at 5.1 years after LDLT. SPT improved only neurological symptoms. Molecular-targeted therapy was given for recurrent PTLD, based on analysis of sampling specimens. This therapy was effective, but tumor lysis syndrome occurred, and the patient died at 5.3 years after LDLT.
    Transplant Infectious Disease 04/2010; 12(4):347-52. · 1.98 Impact Factor
  • Transplantation 01/2010; 90. · 3.78 Impact Factor
  • Clinical Nutrition Supplements 01/2010; 5(2):41-41.
  • International Journal of Infectious Diseases - INT J INFECT DIS. 01/2010; 14.
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    ABSTRACT: A 59-year-old man with hepatitis C virus-associated liver cirrhosis was transferred to our hospital to undergo living donor liver transplantation. Coagulation was impaired (prothrombin time [International Normalized Ratio], 3.27), and antithrombin III (AT-III) activity was 23% (normal, 87%-115%). Contrast-enhanced computed tomography scans revealed portal vein thrombosis (PVT) from the junction between the splenic and superior mesenteric vein to the porta hepatica; the portal vein was completely obstructed (PVT). To prevent further development of PVT, 1500 U of AT-III was administered for 3 days, elevating the AT-III activity to 50%. A contrast-enhanced computed tomography scan obtained 9 days after AT-III administration showed resolution of PVT. Living donor liver transplantation was safely performed without portal vein grafting. Thus, a low AT-III concentration may have an important role in the pathogenesis of PVT in patients with cirrhosis.
    Transplantation Proceedings 11/2009; 41(9):3931-3. · 0.95 Impact Factor
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    ABSTRACT: Des-gamma-carboxy prothrombin (DCP) levels reportedly correlate with histological features of hepatocellular carcinoma (HCC). We examined serum DCP as a predictor of HCC recurrence in 144 patients who underwent living donor liver transplantation. Receiver operating characteristics (ROC) analysis revealed superiority of DCP and AFP over preoperative tumor size or number for predicting recurrence. Multivariate analysis revealed tumor size >5 cm, > or =11 nodules, and DCP >400 mAU/mL as significant independent risk factors for recurrence. Incidence of microvascular invasion (62% vs. 27%, p = 0.0003) and poor differentiation (38% vs. 16%, p = 0.0087) were significantly higher for patients with DCP >400 mAU/mL than for patients with DCP < or =400 mAU/mL. In ROC analysis for patients with < or =10 nodules all < or =5 cm to predict recurrence, area under the curve was much higher for DCP than for AFP (0.84 vs. 0.69). Kyoto criteria were thus defined as < or =10 nodules all < or =5 cm, and DCP < or =400 mAU/mL. The 5-year recurrence rate for 28 patients beyond-Milan but within-Kyoto criteria was as excellent as that for 78 patients within-Milan criteria (3% vs. 7%). The preoperative DCP level offers additional information regarding histological features, and thus can greatly improve patient selection criteria when used with tumor bulk information.
    American Journal of Transplantation 07/2009; 9(10):2362-71. · 6.19 Impact Factor
  • Journal of Surgical Research 02/2009; 151(2):291-291. · 2.02 Impact Factor

Publication Stats

3k Citations
417.13 Total Impact Points

Institutions

  • 1990–2013
    • Kyoto University
      • • Department of Hepato-pancreato-biliary Surgery and Transplantation
      • • Graduate School of Medicine / Faculty of Medicine
      • • Department of Ophthalmology and Visual Sciences
      Kyoto, Kyoto-fu, Japan
  • 2009
    • Kyoto Prefectural University of Medicine
      • Division of Transplantation and General Surgery
      Kioto, Kyōto, Japan
  • 1999–2002
    • Nagoya City University
      • Department of Ophthalmology
      Nagoya, Aichi, Japan
  • 2001
    • Nagoya University
      • Division of Ophtalmology
      Nagoya-shi, Aichi-ken, Japan
  • 1988–1995
    • University of Illinois at Chicago
      • Department of Ophthalmology and Visual Sciences (Chicago)
      Chicago, IL, United States