Ryuichi Yoshida

Dr. Ryuichi Yoshida

Department of Gastroenterological Surgery, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan
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Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 September 2008 in Transplantation
Verified
Journal Article
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YUYuzo Umeda
Yuzo Umeda
TYTakahito Yagi
Takahito Yagi
HSHiroshi Sadamori
Hiroshi Sadamori
HMHiroyoshi Matsukawa
Hiroyoshi Matsukawa
HMHiroaki Matsuda
Hiroaki Matsuda
NTNoriaki Tanaka
Noriaki Tanaka
Background. The small-for-size (SFS) syndrome is caused by excessive portal inflow into a small-sized liver graft. Various approaches for portal decompression have been used, but details of their impact on liver regeneration in SFS graft remain unclear. We examined the effect of prophylactic splenic artery modulation (SAM). Methods. We conducted a retrospective cohort study. The study group was 39 consecutive adult-to-adult living liver transplantation recipients, with a graft-to-recipient body weight ratio of less than 0.8. Patients were assigned into the non-SAM group (n=18, without any portal inflow attenuation) or SAM group (n=21, preoperative embolization in 15 patients and intraoperative ligation in 6 patients). Hepatic hemodynamics, graft function, liver regeneration, and outcome were evaluated. Results. In the SAM group, the excessive portal flow was significantly reduced (P<0.01) and the effect of embolization on portal decompression was equivalent to that of ligation. In the acute postoperative phase, serum transaminases, interleukin-6, and tumor necrosis factor-α, were lower in the SAM group than in non-SAM group. In both groups, a negative correlation was observed between graft-to-recipient body weight ratio and liver regeneration rate at 2 weeks after living donor liver transplantation. Splenic artery modulation was advantageous for liver regeneration, and significantly improved clinical features, hyperbilirubinemia, and prolonged ascites. Small-for-size syndrome occurred in five patients of the non-SAM group, and only one of SAM group (P=0.038). Conclusion. In SFS graft with severe portal hypertension, prophylactic splenic embolization/ligation seems to relieve portal overperfusion injury and contributes in improvement of posttransplantation prognosis through liver regeneration.

11 December 2018 in Journal of Experimental & Clinical Cancer Research
Verified
Journal Article
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KKKazuya Kuwada
Kazuya Kuwada
SKShunsuke Kagawa
Shunsuke Kagawa
RYRyuichi Yoshida
Ryuichi Yoshida
SSShuichi Sakamoto
Shuichi Sakamoto
AIAtene Ito
Atene Ito
TFToshiyoshi Fujiwara
Toshiyoshi Fujiwara
The peritoneum is one of the most frequent metastatic sites in pancreatic cancer patients, and peritoneal dissemination makes this disease refractory due to aggressive progression and chemoresistance. Although the role of the tumor microenvironment in cancer development is recognized, the correlation between the peritoneal environment and refractoriness of peritoneal dissemination remains unclear. The intraperitoneal tumor-microenvironment and its potential role in the progression of peritoneal dissemination and chemo-refractoriness, focusing especially on macrophages, were investigated. Peritoneal washes were obtained from pancreatic cancer patients, and cellular components were subjected to immunofluorescence assays. The effects of macrophages induced from monocytic THP-1 cells on pancreatic cancer cells were examined in co-culture conditions. The in vivo effects of macrophages on tumor growth and chemo-sensitivity were investigated by subcutaneously or intraperitoneally co-injecting cancer cells with macrophages into mice. CD204-positive macrophages were present along with cancer cells in the peritoneal washes. In in vitro co-culture, tumor-associated macrophages affected pancreatic cancer cells, induced the epithelial-to-mesenchymal transition (EMT), and made them more resistant to chemotherapeutic agents. M2 macrophages promoted growth of both subcutaneous tumors and peritoneal dissemination in mice. Furthermore, co-inoculation of M2 macrophages conferred chemoresistance in the peritoneal dissemination mouse model, which significantly shortened their survival. Intraperitoneal tumor-associated macrophages potentially play an important role in promotion of peritoneal dissemination and chemoresistance of pancreatic cancer via EMT induction.

15 June 2013 in Transplant International
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Journal Article
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MUMasashi Utsumi
Masashi Utsumi
YUYuzo Umeda
Yuzo Umeda
HSHiroshi Sadamori
Hiroshi Sadamori
TNTakeshi Nagasaka
Takeshi Nagasaka
ATAkinobu Takaki
Akinobu Takaki
TFToshiyoshi Fujiwara
Toshiyoshi Fujiwara
Acute renal injury (ARI) is a serious complication after liver transplantation. This study investigated the usefulness of the RIFLE criteria in living donor liver transplantation (LDLT) and the prognostic impact of ARI after LDLT. We analyzed 200 consecutive adult LDLT patients, categorized as risk (R), injury (I), or failure (F), according to the RIFLE criteria. ARI occurred in 60.5% of patients: R‐class, 23.5%; I‐class, 21%; and F‐class, 16%. Four patients in Group‐A (normal renal function and R‐class) and 26 patients in Group‐B (severe ARI: I‐ and F‐class) required renal replacement therapy (P < 0.001). Mild ARI did not affect postoperative prognosis regarding hospital mortality rate in Group A (3.2%), which was superior to that in Group B (15.8%; P = 0.0015). Fourteen patients in Group B developed chronic kidney disease (KDIGO stage 3/4). The 1‐, 5‐ and 10‐year survival rates were 96.7%, 90.6%, and 88.1% for Group A and 71.1%, 65.9%, and 59.3% for Group B, respectively (P < 0.0001). Multivariate analysis revealed risk factors for severe ARI as MELD ≥20 [odds ratio (OR) 2.9], small‐for‐size graft (GW/RBW 55 ml/kg (OR 3.7), overexposure to calcineurin inhibitor (OR 2.5), and preoperative diabetes mellitus (OR 3.2). The RIFLE criteria offer a useful predictive tool after LDLT. Severe ARI, defined beyond class‐I, could have negative prognostic impact in the acute and late postoperative phases. Perioperative treatment strategies should be designed and balanced based on the risk factors for the further improvement of transplant prognosis.

1 February 2019 in Clinical Nutrition
Verified
Journal Article
Closed access
KTKosei Takagi
Kosei Takagi
RYRyuichi Yoshida
Ryuichi Yoshida
TYTakahito Yagi
Takahito Yagi
YUYuzo Umeda
Yuzo Umeda
DNDaisuke Nobuoka
Daisuke Nobuoka
TFToshiyoshi Fujiwara
Toshiyoshi Fujiwara

26 May 2017 in BMC Surgery
Verified
Journal Article
Open access
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KTKosei Takagi
Kosei Takagi
RYRyuichi Yoshida
Ryuichi Yoshida
TYTakahito Yagi
Takahito Yagi
YUYuzo Umeda
Yuzo Umeda
DNDaisuke Nobuoka
Daisuke Nobuoka
TFToshiyoshi Fujiwara
Toshiyoshi Fujiwara
Recently, skeletal muscle depletion (sarcopenia) has been reported to influence postoperative outcomes after certain procedures. This study investigated the impact of sarcopenia on postoperative outcomes following pancreaticoduodenectomy (PD). We performed a retrospective study of consecutive patients (n = 219) who underwent PD at our institution between January 2007 and May 2013. Sarcopenia was evaluated using preoperative computed tomography. We evaluated postoperative outcomes and the influence of sarcopenia on short-term outcomes, especially infectious complications. Subsequently, multivariate analysis was used to assess the impact of prognostic factors (including sarcopenia) on postoperative infections. The mortality, major complication, and infectious complication rates for all patients were 1.4%, 16.4%, and 47.0%, respectively. Fifty-five patients met the criteria for sarcopenia. Sarcopenia was significantly associated with a higher incidence of in-hospital mortality (P = 0.004) and infectious complications (P < 0.001). In multivariate analyses, sarcopenia (odds ratio = 3.43; P < 0.001), preoperative biliary drainage (odds ratio = 2.20; P = 0.014), blood loss (odds ratio = 1.92; P = 0.048), and soft pancreatic texture (odds ratio = 3.71; P < 0.001) were independent predictors of postoperative infections. Sarcopenia is an independent preoperative predictor of infectious complications after PD. Clinical assessment combined with sarcopenia may be helpful for understanding the risk of postoperative outcomes and determining perioperative management strategies.

1 March 2001 in International Journal of Oncology
Verified
Journal Article
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RYRyuichi Yoshida
Ryuichi Yoshida
NKNORIKO KIMURA
NORIKO KIMURA
YHY. Harada
Y. Harada
NON. Ohuchi
N. Ohuchi
Loss of E-cadherin and catenin expression may be associated with distant and lymph node metastases in breast cancer. Heterogeneity of E-cadherin expression is associated with poor prognosis, suggesting that E-cadherin and catenins may serve as useful prognostic markers for invasive breast carcinoma. Reduction or loss of expression of either E-cadherin or catenins is associated with invasion, metastasis and poor prognosis in several types of human malignancies. We investigated the expression of E-cadherin, and α- and β-catenins by immunohistochemistry in 171 cases of primary invasive breast cancer, and compared the expression with clinicopathological parameters to define the relationship between expression and prognosis. E-cadherin immunoreactive protein was shown to be expressed in 97 cases. Reduction or lack of expression of E-cadherin was associated with distant metastasis. Based on immunohistochemical heterogeneity, E-cadherin-positive tumors were classified into heterogeneous, homogeneous and intermediate types. Interestingly, although patients with heterogeneous type demonstrated the lowest incidence of distant metastasis at diagnosis, they showed a higher incidence of subsequent distant metastasis, after surgery, and a lower survival rate than those with homogeneous type (p<0.05). E-cadherin expression was reduced or negative in metastatic axillary lymph nodes regardless of the expression in the primary tumor, suggesting that changes in E-cadherin expression are associated with not only distant metastasis but also lymph node metastasis. Tumors negative for either α- or β-catenin expression demonstrated a higher incidence of distant metastasis than those expressing both catenins, suggesting that the expression of catenins is involved in breast cancer metastasis. Reduction or loss of E-cadherin and catenin expression may be associated with distant and lymph node metastases in invasive breast cancer, and the heterogeneous type may be associated with poor prognosis.