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Dive into the research topics where Tomoaki Yoh is active.

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Featured researches published by Tomoaki Yoh.


Liver cancer | 2016

Is Surgical Resection Justified for Advanced Intrahepatic Cholangiocarcinoma

Tomoaki Yoh; Etsuro Hatano; Kenya Yamanaka; Takahiro Nishio; Satoru Seo; Kojiro Taura; Kentaro Yasuchika; Hideaki Okajima; Toshimi Kaido; Shinji Uemoto

Backgrounds: Prognosis for patients with advanced intrahepatic cholangiocarcinoma (ICC) with intrahepatic metastasis (IM), vascular invasion (VI), or regional lymph node metastasis (LM) remains poor. The aim of this study was to clarify the indications for surgical resection for advanced ICC. Methods: We retrospectively divided 213 ICC patients treated at Kyoto University Hospital between 1993 and 2013 into a resection (n=164) group and a non-resection (n=49) group. Overall survival was assessed after stratification for the presence of IM, VI, or LM. Results: Overall median survival times (MSTs) for the resection and non-resection groups were 26.0 and 7.1 months, respectively (p<0.001). After stratification, MSTs in the resection and non-resection groups, respectively, were 18.7 vs. 7.0 months for patients with IM (p<0.001), 23.4 vs. 5.7 months for those with VI (p<0.001), and 12.8 vs. 5.5 months for those with LM (p<0.001). Conclusion: When macroscopic curative resection is possible, surgical resection can be justified for some advanced ICC patients with IM, VI, or LM.


Surgery Today | 2017

Is routine abdominal drainage necessary after liver resection

Seidai Wada; Etsuro Hatano; Tomoaki Yoh; Satoru Seo; Kojiro Taura; Kentaro Yasuchika; Hideaki Okajima; Toshimi Kaido; Shinji Uemoto

PurposeProphylactic abdominal drainage is performed routinely after liver resection in many centers. The aim of this study was to examine the safety and validity of liver resection without abdominal drainage and to clarify whether routine abdominal drainage after liver resection is necessary.MethodsPatients who underwent elective liver resection without bilio-enteric anastomosis between July, 2006 and June, 2012 were divided into two groups, based on whether surgery was performed before or after, we adopted the no-drain strategy. The “former group” comprised 256 patients operated on between July, 2006 and June, 2009 and the “latter group” comprised 218 patients operated between July, 2009 and June, 2012. We compared the postoperative complications, percutaneous drainage, and postoperative hospital stay between the groups, retrospectively.ResultsThere were no significant differences in the rates of postoperative bleeding, intraabdominal infection, or bile leakage between the groups. Drain insertion after liver resection did not reduce the rate of percutaneous drainage. Postoperative hospital stay was significantly shorter in the latter group.ConclusionRoutine abdominal drainage is unnecessary after liver resection without bilio-enteric anastomosis.


Liver Transplantation | 2018

CAAT/enhancer binding protein–homologous protein deficiency attenuates liver ischemia/reperfusion injury in mice

Seidai Wada; Etsuro Hatano; Tomoaki Yoh; Naohiko Nakamura; Yukihiro Okuda; Masayuki Okuno; Yosuke Kasai; Keiko Iwaisako; Satoru Seo; Kojiro Taura; Shinji Uemoto

Ischemia/reperfusion injury (IRI) is one of the main causes of liver dysfunction after liver surgery. Involvement of endoplasmic reticulum (ER) stress in various diseases has been demonstrated, and CAAT/enhancer binding protein–homologous protein (CHOP) is a transcriptional regulator that is induced by ER stress. It is also a key regulator of ER stress‐mediated apoptosis. The aim of this study was to investigate the role of CHOP in liver IRI. Wild type (WT) and CAAT/enhancer binding protein–homologous protein knockout (CHOP–/–) mice were subjected to 70% liver warm ischemia/reperfusion for 60 minutes. At different times after reperfusion, liver tissues and blood samples were collected for evaluation. Induction of ER stress including CHOP expression was ascertained. Liver damage was evaluated based on serum liver enzymes, liver histology, and neutrophil infiltration. Hepatocyte death including apoptosis was assessed. Liver warm IRI induced ER stress in both WT and CHOP–/– mice. In addition, CHOP expression was up‐regulated in WT mice. At 6 hours after reperfusion, liver damage was attenuated in CHOP–/– mice. On the basis of terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick‐end labeling staining, apoptotic and necrotic cells were significantly reduced in CHOP–/– mice. CHOP deficiency also reduced the cleavage of caspase 3 and expression of the proapoptotic protein B cell lymphoma 2–associated X protein. Liver IRI induces CHOP expression, and CHOP deficiency attenuates liver IRI by inhibiting apoptosis. Elucidation of the function of CHOP in liver IRI may contribute to further investigation for a therapy against liver IRI associated with the ER stress pathway. Liver Transplantation 24 645–654 2018 AASLD.


Journal of Translational Medicine | 2018

Preoperative metabolic tumor volume of intrahepatic cholangiocarcinoma measured by 18 F-FDG-PET is associated with the KRAS mutation status and prognosis

Yoshinobu Ikeno; Satoru Seo; Keiko Iwaisako; Tomoaki Yoh; Yuji Nakamoto; Hiroaki Fuji; Kojiro Taura; Hideaki Okajima; Toshimi Kaido; Shimon Sakaguchi; Shinji Uemoto

BackgroundSurgical resection remains the mainstay of curative treatment for intrahepatic cholangiocarcinoma (ICC). Prognosis after surgery is unsatisfactory despite improvements in treatment and post-operative clinical management. Despite developments in the molecular profiling of ICC, the preoperative prediction of prognosis remains a challenge. This study aimed to identify clinical prognostic indicators by investigating the molecular profiles of ICC and evaluating the preoperative imaging data of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET).MethodsA retrospective analysis was performed on 50 consecutive patients with ICC who underwent curative hepatectomy after 18F-FDG-PET examination. To evaluate the molecular profiles of ICC, KRAS mutation status was assessed in resected specimens. For the assessment of glucose uptake, we observed the expression of glucose transporter-1 (GLUT-1) by immunohistochemistry. The data of 18F-FDG-PET were re-evaluated as follows: maximum standardized uptake value, metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Cut-off values were determined using receiver operating characteristic (ROC) curve analysis. Cumulative overall survival (OS) was analyzed using the Kaplan–Meier analysis.ResultsOverall, 16 (32.0%) patients had mutations in KRAS. Patients with mutated KRAS exhibited shorter OS than those with wild-type KRAS (5-year OS, 0% vs. 35.1%, P < 0.001). GLUT-1 expression was significantly higher in tumors with mutated KRAS than in tumors with wild-type KRAS (median, 4.0 vs. 1.0, P < 0.001). Survival was significantly different when stratified by expression of GLUT-1 (5-year OS, 0% vs. 46.5%, P <0.001). Among the 18F-FDG-PET parameters, the MTV and TLG were significantly higher in the mutated KRAS group than in the wild-type KRAS group (P = 0.013 and P = 0.026, respectively). ROC curve analysis revealed a cut-off value of 38 for the MTV, with the highest accuracy (area under the curve = 0.789; 95% confidence interval, 0.581–0.902) for predicting KRAS mutation. This cut-off value permitted stratification of OS (high vs. low: 5-year OS, 13.1% vs. 36.7%, P = 0.008).ConclusionsHigh MTV is associated with KRAS mutation and poor postoperative outcomes in patients with ICC, suggesting that the MTV of ICC measured by 18F-FDG-PET may provide useful information for tumor molecular profiles and prognosis.


Journal of Hepato-biliary-pancreatic Sciences | 2018

Preoperative criterion identifying a low-risk group for lymph node metastasis in intrahepatic cholangiocarcinoma

Tomoaki Yoh; Etsuro Hatano; Satoru Seo; Hiroaki Terajima; Yoichiro Uchida; Kojiro Taura; Kentaro Yasuchika; Shinji Uemoto

Imaging study cannot identify patients with potential low‐risk for lymph node (LN) metastasis in intrahepatic cholangiocarcinoma (ICC). The purpose of this study was to identify a low‐risk group for LN metastasis in ICC using preoperatively available factors.


Asian Journal of Endoscopic Surgery | 2018

Optimal introduction of laparoscopic liver resection for Child-Pugh B: LLR for Child-Pugh B cirrhosis

Hiroaki Fuji; Satoru Seo; Rei Toda; Tomoaki Yoh; Yoshinobu Ikeno; Ken Fukumitsu; Takamichi Ishii; Kojiro Taura; Etsuro Hatano; Toshimi Kaido; Shinji Uemoto

Surgery for Child–Pugh B liver function is considered risky because of its high morbidity rate and the acceptable indication criteria for laparoscopic liver resection (LLR) for Child–Pugh B patients have not been identified. We conducted a retrospective cohort study to determine the optimal introduction of LLR for Child–Pugh B patients based on our single‐institute experience.


Asian Journal of Endoscopic Surgery | 2018

Laparoscopic appendectomy during the third trimester: Case presentation and literature review: Lap appendectomy in the third trimester

Sena Iwamura; Hiroki Hashida; Tomoaki Yoh; Shoichi Kitano; Motoko Mizumoto; Koji Kitamura; Masato Kondo; Hiroyuki Kobayashi; Satoshi Kaihara; Ryo Hosotani

Acute appendicitis is the most common general surgical problem encountered during pregnancy. Laparoscopic appendectomy (LA) is widely accepted as a minimally invasive procedure for acute appendicitis. However, LA during the third trimester is associated with problems, including technical difficulty, risk of preterm delivery, and fetal loss. We successfully managed three cases of LA during the third trimester between 2011 and 2016. None of the cases required conversion to an open procedure, and none of the patients had postoperative complications and/or fetal loss. We reviewed the literature using the PubMED database from 2007 to 2016 to acquire further evidence and identified 6 reports and 17 cases. The conversion rate was 11.8% (2 cases), the complication rate was 6.67% (1 case), and the preterm delivery rate was 20% (3 cases); no fetal loss was observed. Our study and literature review highlights the role of LA as a potentially feasible treatment approach for appendicitis during the third trimester.


Anticancer Research | 2018

Usefulness of Preoperative18F-FDG-PET in Detecting Invasive Intraductal Papillary Neoplasm of the Bile Duct

Yoshinobu Ikeno; Satoru Seo; Gen Yamamoto; Yuji Nakamoto; Yusuke Uemoto; Hiroaki Fuji; Kenji Yoshino; Tomoaki Yoh; Kojiro Taura; Shinji Uemoto

Background/Aim: Preoperative identification of the invasive component remains challenging in intraductal papillary neoplasm of the bile duct (IPNB). We evaluated the ability of preoperative 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) to differentiate between non-invasive IPNB, invasive IPNB, and papillary cholangiocarcinoma (CCA). Patients and Methods: The maximum standardized uptake values (SUVmax) of 11 patients with IPNB (6 non-invasive and 5 invasive) and 20 with papillary CCA who underwent pre-surgical 18F-FDG-PET were assessed. The SUVmax cut-off that predicts an invasive component was determined using receiver operating characteristic (ROC) curve analysis. Results: The SUVmax in patients with invasive IPNB and papillary CCA were significantly higher than in patients with non-invasive IPNB (p=0.035 and 0.0025, respectively). ROC curve analysis revealed an optimal SUVmax cut-off of 4.5, which had 94.5% accuracy, 76.0% sensitivity, and 100% specificity. Conclusion: Our data suggest that the preoperative 18F-FDG-PET SUVmax can differentiate non-invasive IPNB from invasive IPNB and papillary CCA.


Annals of Surgical Oncology | 2018

ASO Author Reflections: Proposal of a New Preoperative Prognostic Model for Solitary Hepatocellular Carcinoma

Tomoaki Yoh; Satoru Seo

In the era of multidisciplinary surgical strategies for the treatment of hepatocellular carcinoma (HCC), preoperative assessment of prognosis plays an increasingly pivotal role. However, existing prognostic systems were not developed using only objective variables available preoperatively, and therefore do not provide ideal prognostication for patients undergoing hepatectomy for HCC. The albumin–bilirubin (ALBI) grade was recently established as an objective parameter that estimates liver function. However, as a candidate marker that can be incorporated with the ALBI grade in a preoperative prognostic model, we focused on F-fluorodeoxyglucose-positron emission tomography (F-FDG-PET) imaging, which visualizes tumor glucose metabolism. The purpose of our study was to develop a preoperative prognostic model using clinical parameters involving F-FDG-PET imaging findings and the ALBI grade for patients undergoing hepatectomy for solitary HCC.


Cancer Science | 2017

Nardilysin promotes hepatocellular carcinoma through activation of signal transducer and activator of transcription 3

Yosuke Kasai; Kan Toriguchi; Etsuro Hatano; Kiyoto Nishi; Mikiko Ohno; Tomoaki Yoh; Keita Fukuyama; Takahiro Nishio; Masayuki Okuno; Keiko Iwaisako; Satoru Seo; Kojiro Taura; Masato Kurokawa; Makoto Kunichika; Shinji Uemoto; Eiichiro Nishi

Nardilysin (NRDC) is a metalloendopeptidase of the M16 family. We previously showed that NRDC activates inflammatory cytokine signaling, including interleukin‐6‐signal transducer and activator of transcription 3 (STAT3) signaling. NRDC has been implicated in the promotion of breast, gastric and esophageal cancer, as well as the development of liver fibrosis. In this study, we investigated the role of NRDC in the promotion of hepatocellular carcinoma (HCC), both clinically and experimentally. We found that NRDC expression was upregulated threefold in HCC tissue compared to the adjacent non‐tumor liver tissue, which was confirmed by immunohistochemistry and western blotting. We also found that high serum NRDC was associated with large tumor size (>3 cm, P = 0.016) and poor prognosis after hepatectomy (median survival time 32.0 vs 73.9 months, P = 0.003) in patients with hepatitis C (n = 120). Diethylnitrosamine‐induced hepatocarcinogenesis was suppressed in heterozygous NRDC‐deficient mice compared to their wild‐type littermates. Gene silencing of NRDC with miRNA diminished the growth of Huh‐7 and Hep3B spheroids in vitro. Notably, phosphorylation of STAT3 was decreased in NRDC‐depleted Huh‐7 spheroids compared to control spheroids. The effect of a STAT3 inhibitor (S3I‐201) on the growth of Huh‐7 spheroids was reduced in NRDC‐depleted cells relative to controls. Our results show that NRDC is a promising prognostic marker for HCC in patients with hepatitis C, and that NRDC promotes tumor growth through activation of STAT3.

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