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Dive into the research topics where Shinichi Ikuta is active.

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Featured researches published by Shinichi Ikuta.


Shock | 2004

Enhanced interferon-gamma production and bacterial clearance in the liver of splenectomized mice in the models of Escherichia coli injection or intestinal obstruction.

Shinichi Ikuta; Satoshi Ono; Manabu Kinoshita; Shuhji Seki; Hoshio Hiraide; Hidetaka Mochizuki

Although several studies have reported that splenectomy increases susceptibility to bacterial infections, other reports have indicated that splenectomy does not induce such susceptibility. To clarify this discrepancy, we studied the effects of splenectomy in the models of lipopolysaccharide (LPS) or Escherichia coli challenge and intestinal obstruction, focusing on cytokine production and bacterial clearance in the liver. Using C57BL/6 mice at 4 weeks after splenectomy or a sham operation, either LPS or E. coli was injected or an intestinal obstruction was made to examine the mortality, serum cytokine levels, cytokine production of the liver mononuclear cells (MNCs), and bacterial clearance in the liver. As a result, no differences were observed in survival rates after LPS or E. coli challenge between the mice with and without splenectomy. However, in a model of intestinal obstruction, splenectomized mice survived significantly longer than the sham-operated mice. Liver MNCs from splenectomized mice produced a significantly larger amount of interferon-γ compared with those from sham-operated mice. Furthermore, bacterial counts in the liver at 2 h after E. coli injection and at 24 h after intestinal obstruction were significantly decreased in splenectomized mice compared with sham-operated mice. In conclusion, splenectomy does not impair host defense against bacteria infection provided that recovery is sufficient to allow compensatory processes in the liver to occur.


World Journal of Gastroenterology | 2012

Comparison of percutaneous transhepatic portal vein embolization and unilateral portal vein ligation

Hiroya Iida; Tsukasa Aihara; Shinichi Ikuta; Hidenori Yoshie; Naoki Yamanaka

AIM To compare the effect of percutaneous transhepatic portal vein embolization (PTPE) and unilateral portal vein ligation (PVL) on hepatic hemodynamics and right hepatic lobe (RHL) atrophy. METHODS Between March 2005 and March 2009, 13 cases were selected for PTPE (n = 9) and PVL (n = 4) in the RHL. The PTPE group included hilar bile duct carcinoma (n = 2), intrahepatic cholangiocarcinoma (n = 2), hepatocellular carcinoma (n = 2) and liver metastasis (n = 3). The PVL group included hepatocellular carcinoma (n = 2) and liver metastasis (n = 2). In addition, observation of postoperative hepatic hemodynamics obtained from computed tomography and Doppler ultrasonography was compared between the two groups. RESULTS Mean ages in the two groups were 58.9 ± 2.9 years (PVL group) vs 69.7 ± 3.2 years (PTPE group), which was a significant difference (P = 0.0002). Among the indicators of liver function, including serum albumin, serum bilirubin, aspartate aminotransferase, alanine aminotransferase, platelets and indocyanine green retention rate at 15 min, no significant differences were observed between the two groups. Preoperative RHL volumes in the PTPE and PVL groups were estimated to be 804.9 ± 181.1 mL and 813.3 ± 129.7 mL, respectively, with volume rates of 68.9% ± 2.8% and 69.2% ± 4.2%, respectively. There were no significant differences in RHL volumes (P = 0.83) and RHL volume rates (P = 0.94), respectively. At 1 mo after PTPE or PVL, postoperative RHL volumes in the PTPE and PVL groups were estimated to be 638.4 ± 153.6 mL and 749.8 ± 121.9 mL, respectively, with no significant difference (P = 0.14). Postoperative RHL volume rates in the PTPE and PVL groups were estimated to be 54.6% ± 4.2% and 63.7% ± 3.9%, respectively, which was a significant difference (P = 0.0056). At 1 mo after the operation, the liver volume atrophy rate was 14.3% ± 2.3% in the PTPE group and 5.4% ± 1.6% in the PVL group, which was a significant difference (P = 0.0061). CONCLUSION PTPE is a more effective procedure than PVL because PTPE is able to occlude completely the portal branch throughout the right peripheral vein.


Hepato-gastroenterology | 2013

A comparative study of therapeutic effect between laparoscopic microwave coagulation and laparoscopic radiofrequency ablation.

Hiroya Iida; Tsukasa Aihara; Shinichi Ikuta; Naoki Yamanaka

BACKGROUND/AIMS We retrospectively compared the therapeutic effect of microwave coagulation needle (Lap-MCT) and radiofrequency ablation needle (Lap-RFA). METHODOLOGY Between January 2001 and May 2012, 71 patients underwent laparoscopic ablation therapy for HCC with no extra hepatic metastasis. These patients were divided into 3 groups, according to the surgical strategies: Lap-MCT (n=40), Lap-MCT+RFA (n=13) and Lap-RFA (n=18). The patient background, tumor characteristics, cumulative survival rate, recurrence-free survival rate, time of operation and duration of hospitalization were compared between the groups. RESULTS The maximal tumor size, the number of tumors and the hepatic reserve from each group had no significant difference. Likewise, the time of operation and the duration of hospitalization had no significant difference. However, the number of needle punctures in the Lap-MCT group was significantly larger than that in the Lap-RFA group (p<0.05). Postoperative liver function had no significant difference between the groups. The 5-year cumulative survival rate was 71.5% (Lap-MCT), 66.7% (Lap-MCT+RFA) and 80.0% (Lap-RFA) showing no significant difference. Also, the recurrence-free survival rate and the local recurrence rate had no significant difference. CONCLUSIONS In the laparoscopic setting, MCT and RFA are equally effective in terms of short- and long-term results.


Pathology International | 2006

Oncocytic non-functioning endocrine tumor of the pancreas

Ayako Sugihara; Keiji Nakasho; Shinichi Ikuta; Tsukasa Aihara; Takashi Kawai; Hiroya Iida; Hidenori Yoshie; Chiaki Yasui; Masao Mitsunobu; Kiyohiko Kishi; Toshio Mori; Naoko Yamada; Koji Yamanegi; Hideki Ohyama; Nobuyuki Terada; Nobuyuki Ohike; Toshio Morohoshi; Naoki Yamanaka

Herein is presented the case of a malignant non‐functioning endocrine tumor of the pancreas with oncocytic features, and a discussion on the high incidence of malignancy in oncocytic endocrine pancreatic tumors. The patient was a 65‐year‐old woman who showed no paraneoplastic symptoms produced by functioning pancreatic endocrine tumors. The primary tumor was located in the body and tail of the pancreas, and had metastasized to the liver. Tumor cells were arranged in a ribbon‐like or trabecular pattern and had an abundant eosinophilic cytoplasm containing numerous mitochondria and neurosecretory granules. The cytoplasm of the tumor cells was intensely stained with an antimitochondrial antigen antibody. Most tumor cells stained positively with Grimelius stain and for chromogranin A. Some tumor cells also stained for synaptophysin. However, the tumor cells negatively stained for hormones such as insulin, glucagon, somatostatin, gastrin, vasoactive intestinal peptide and pancreatic polypeptide, for serotonin, and for pancreatic enzymes such as amylase and trypsin. Analysis of 18 oncocytic pancreatic endocrine tumors, consisting of those reported previously and that in the present case, suggests that the high incidence of malignancy in oncocytic endocrine tumors is associated with the high incidence of non‐functioning endocrine tumors among them, most of which are malignant.


Digestive Surgery | 2003

Serum Immunosuppressive Acidic Protein as an Interleukin-6 Related Index of Deteriorating Condition in Gastric Cancer Patients

Shinichi Ikuta; Chikao Miki; Koji Tanaka; Naomi Konishi; Yasuhiko Mohri; Hitoshi Tonouchi; Masato Kusunoki

Background/Aims: Immunosuppressive acidic protein (IAP) is an acute-phase reactant which has a close correlation with the impairment of the host’s immunity. The present study aims to investigate the significance of serum IAP as an index of cytokine-related disease status in gastric cancer patients. Methods: Serum IAP levels were determined in 76 gastric cancer patients and 20 healthy subjects. In a subgroup of 39 patients, tissue interleukin-6 (IL-6) concentrations and expression of IL-6 protein in tumor tissues were also examined. Results: The mean serum IAP level in the patients was significantly higher than that in the normal controls. The serum IAP level in the patients was associated with clinicopathological features, such as tumor size and serosal invasion. The prognosis of patients with high IAP levels was significantly worse than that of those with low IAP levels. Moreover, the serum IAP level was closely correlated with various parameters reflecting the host’s nutritional and immunological conditions. Immunohistochemically, IL-6 was overexpressed in the cytoplasm of tumor cells. The IL-6 concentration and immunoreactivity of IL-6 protein in tumor tissue was significantly correlated with the serum IAP level. Conclusions: Elevated serum IAP, which may be upregulated by an activated IL-6 network in tumor tissue, may reflect not only tumor progression, but also a deteriorated condition that is associated with malnutrition and immunosuppression in gastric cancer patients.


World journal of clinical oncology | 2012

Optimal combination of radiofrequency ablation with chemoradiotherapy for locally advanced pancreatic cancer.

Shinichi Ikuta; Ami Kurimoto; Hiroya Iida; Tsukasa Aihara; Makiko Takechi; Norihiko Kamikonya; Naoki Yamanaka

Problems have been reported in the treatment of pancreatic cancer with radiofrequency ablation (RFA), such as the friability of the organ itself. This report presents possible solutions to such problems. Although our patient suffered from locally advanced unresectable pancreatic cancer, she remained well at 18 mo after RFA with no evidence of recurrence. To ameliorate the side effects of RFA, after a palliative bypass procedure, the subject was treated with combined radiotherapy and chemotherapy. After this regimen had been administered, a contrast-enhanced computed tomography scan confirmed that RFA is a viable approach to the treatment of pancreatic cancer as the chemoradiotherapy had resulted in marked tumor shrinkage and pancreatic fibrosis; i.e., sufficient tumor ablation was achieved without serious RFA-related complications, such as pancreatitis or pancreatic fistulae. The present case suggests that RFA combined with preceding chemoradiotherapy is safe and effective for the palliative treatment of locally advanced pancreatic cancer.


World Journal of Gastroenterology | 2012

Effectiveness of impedance monitoring during radiofrequency ablation for predicting popping.

Hiroya Iida; Tsukasa Aihara; Shinichi Ikuta; Naoki Yamanaka

AIM To retrospectively evaluate the effectiveness of impedance monitoring for predicting popping during radiofrequency ablation (RFA) using internally cooled electrodes. METHODS We reviewed 140 patients (94 males, 46 females; age range 73.0 ± 11.1 year) who underwent RFA between February 2006 and November 2008 with a modified protocol using a limited power delivery rather than a conventional one to avoid popping. All the patients provided their written informed consent, and the study was approved by the institutional review board. Intraprocedural impedances were measured for the study subjects, and the tumors were classified into three types according to the characteristics of their impedance curves: increasing, flat, or decreasing. The tumors were further sorted into seven subtypes (A-G) depending on the curvature of the impedance curves increase or decrease. Relative popping rates were determined for the three types and seven subtypes. A chi-square test was performed to estimate statistical significance. RESULTS A total of 148 nodules treated by RFA were analyzed. The study samples included 132 nodules of hepatocellular carcinoma, 14 nodules of metastatic liver cancer, and two nodules of intrahepatic cholangiocarcinoma. The numbers of nodules with each impedance curve type were as follows: 37 increasing-type nodules, 43 flat-type nodules, and 68 decreasing-type nodules. Popping occurrence rates were 24.3%, 46.5% and 64.7%, respectively. Flat-type nodules exhibited a significantly higher rate of popping compared to increasing-type nodules (P = 0.039). Decreasing-type nodules exhibited a significantly higher rate of popping compared to increasing-type nodules (P < 0.0001). Notably, nodules that showed a sharp decrease in impedance in the latter ablation period (subtype E) exhibited a significantly higher rate of popping compared to other subtypes. CONCLUSION Intraprocedural impedance monitoring can be a useful tool to predict the occurrence of popping during liver tumor RFA performed with internally cooled electrodes.


Hepatology Research | 2014

Comparative study of percutaneous radiofrequency ablation and hepatic resection for small, poorly differentiated hepatocellular carcinomas.

Hiroya Iida; Tsukasa Aihara; Shinichi Ikuta; Naoki Yamanaka

Histologically, poorly differentiated hepatocellular carcinomas (HCC) are considered highly malignant. Here, we aimed to evaluate the relative efficacy and safety of hepatic resection or radiofrequency ablation (RFA) for treating this malignancy.


World Journal of Gastroenterology | 2011

Simultaneous bile duct and portal venous branch ligation in two-stage hepatectomy

Hiroya Iida; Chiaki Yasui; Tsukasa Aihara; Shinichi Ikuta; Hidenori Yoshie; Naoki Yamanaka

Hepatectomy is an effective surgical treatment for multiple bilobar liver metastases from colon cancer; however, one of the primary obstacles to completing surgical resection for these cases is an insufficient volume of the future remnant liver, which may cause postoperative liver failure. To induce atrophy of the unilateral lobe and hypertrophy of the future remnant liver, procedures to occlude the portal vein have been conventionally used prior to major hepatectomy. We report a case of a 50-year-old woman in whom two-stage hepatectomy was performed in combination with intraoperative ligation of the portal vein and the bile duct of the right hepatic lobe. This procedure was designed to promote the atrophic effect on the right hepatic lobe more effectively than the conventional technique, and to the best of our knowledge, it was used for the first time in the present case. Despite successful induction of liver volume shift as well as the following procedure, the patient died of subsequent liver failure after developing recurrent tumors. We discuss the first case in which simultaneous ligation of the portal vein and the biliary system was successfully applied as part of the first step of two-stage hepatectomy.


Wspolczesna Onkologia-Contemporary Oncology | 2018

Efficacy of sequential sorafenib plus hepatic arterial infusion chemotherapy in patients with Barcelona Clinic Liver Cancer stage B and C hepatocellular carcinoma: a retrospective single-institution study

Shinichi Ikuta; Tsukasa Aihara; Naoki Yamanaka

Aim of the study To evaluate the efficacy of sequential combination therapy using sorafenib and hepatic arterial infusion chemotherapy (HAIC) in patients with Barcelona Clinic Liver Cancer stage B/C hepatocellular carcinoma (HCC). Material and methods We recruited 98 BCLC stage B/C HCC patients at our institute, who received either sorafenib monotherapy or planned sequential sorafenib-HAIC combination therapy. A total of 26 patients (combination group) received sorafenib for one or two months, followed by HAIC with a single dose of cisplatin-lipiodol suspension and a continuous infusion of 5-fluorouracil. Sorafenib-HAIC cycles were repeated every 2–3 months. The remaining 72 patients (control group) were treated with sorafenib alone. Clinical characteristics and treatment outcomes were compared between the groups. Inverse probability weighting (IPW) using propensity scores was applied to adjust for the between-group differences in baseline characteristics. Results The combination group had a significantly lower frequency of extrahepatic metastasis and BCLC stage C disease compared with the control group but had more intrahepatic lesions. The crude median overall survival (OS) was 17.1 months in the combination group compared with 9.7 months in the control group (p = 0.01). The objective response rate was 23.1% in the combination group vs. 6.9% in the control group (p = 0.06). Multivariate analysis identified receipt of sorafenib-HAIC combination (HR: 0.521, 95% CI: 0.297–0.915, p = 0.02) and α-fetoprotein (≥ 400 ng/ml) at baseline as independent factors associated with OS. After adjustment with IPW the combination group still had significantly better OS than the control group (p = 0.04). Conclusions The sequential sorafenib-HAIC combination can be an effective and promising treatment option for selected patients with BCLC stage B/C HCC.

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Naoki Yamanaka

Hyogo College of Medicine

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Tsukasa Aihara

National Defense Medical College

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Hiroya Iida

Shiga University of Medical Science

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Hidenori Yanagi

Hyogo College of Medicine

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Chiaki Yasui

Hyogo College of Medicine

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Masao Mitsunobu

Hyogo College of Medicine

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Takashi Sonoda

Mitsubishi Heavy Industries

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Kayo Inoue

Hyogo College of Medicine

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