Shinwa Tanaka

Publications (12)21.48 Total impact

• Article: Endoscopic vessel sealing: A novel endoscopic precoagulation technique for blood vessels during endoscopic submucosal dissection.

  Shinwa Tanaka, Takashi Toyonaga, Yoshinori Morita
  Digestive Endoscopy 03/2013; · 1.19 Impact Factor
• Article: Endoscopic submucosal dissection for gastric neoplasm in patients with co-morbidities categorized according to the ASA Physical Status Classification.

  Mariko Man-I, Yoshinori Morita, Tsuyoshi Fujita, James E East, Shinwa Tanaka, Chika Wakahara, Masaru Yoshida, Takanobu Hayakumo, Hiromu Kutsumi, Hideto Inokuchi, Takashi Toyonaga, Takeshi Azuma
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  ABSTRACT: BACKGROUND: Endoscopic submucosal dissection (ESD) has come to be widely performed for reduced invasiveness; however, its safety in patients with co-morbidities is not fully examined. We aimed to evaluate the safety and efficacy of gastric ESD with co-morbidities categorized according to ASA Physical Status Classification. METHODS: Two hundred and forty patients of ASA 1 (no co-morbidities), 268 of ASA 2 (mild), and 19 of ASA 3 (severe) were treated by ESD for gastric neoplasms. We retrospectively compared clinicopathological features and treatment results of these three groups. RESULTS: Cases (by percent) treated with anticoagulant/platelet agents were more common in the higher ASA grades (ASA 1, 5.8%; ASA 2, 29.1%; ASA 3, 31.6%; P < 0.0001). There were no significant differences in case numbers treated under guideline criteria, curative resection (ASA 1, 79.6%; ASA 2, 79.9%; ASA 3, 78.9%), or complications related to the ESD procedure (e.g., postoperative bleeding, perforation, thermal injury). By a patient risk prediction model on surgery, i.e., P-POSSUM, morbidity was halved, and no patients died compared to a predicted death rate of 0.5-2%; however, total and complications unrelated to ESD procedure (e.g., aspiration pneumonia, ischemic heat attack) were more common in higher ASA grades (ASA 1, ASA 2, ASA 3: 15.4, 23.9, 26.3%, respectively, P = 0.014; 0.4, 7.1, 0%, respectively, P = 0.00087). Deviation rates from clinical pathway were more frequent and hospital stay (days) longer in higher ASA grades (ASA 1, ASA 2, ASA 3: 11.3, 17.9, 26.3%, respectively, P = 0.014; 8, 8, 9%, respectively, P = 0.0053). CONCLUSIONS: ESD is an efficient treatment for gastric neoplasms with co-morbidities. However, additional caution is required because co-morbidity is a risk factor for both total complications and complications unrelated to the ESD procedure, and may cause deviations in the clinical course and prolonged hospital stay.
  Gastric Cancer 03/2012; · 2.42 Impact Factor
• Article: Clinicopathological characteristics of abnormal micro-lesions at the oro-hypopharynx detected by a magnifying narrow band imaging system.

  Shinwa Tanaka, Yoshinori Morita, Tsuyoshi Fujita, Hiroshi Yokozaki, Daisuke Obata, Shoko Fujiwara, Chika Wakahara, Atsuhiro Masuda, Maki Sugimoto, Tsuyoshi Sanuki, Masaru Yoshida, Takashi Toyonaga, Hiromu Kutsumi, Takeshi Azuma
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  ABSTRACT: Narrow band imaging (NBI) with magnifying endoscopy (NBI-ME) allows the detection of abnormal micro-lesions smaller than 5 mm in diameter in the oro-hypopharynx that could not be visualized previously. The purpose of the present study was to clarify the clinicopathological characteristics of abnormal micro-lesions of the oro-hypopharynx detected by NBI-ME. Of the 62 lesions detected by NBI-ME, 40 abnormal micro-lesions in 37 patients were removed by endoscopic treatment and were pathologically evaluated. We reviewed the medical records of patients with these lesions and investigated the relationship between NBI-ME findings and pathological findings. Pathological examination revealed the following: high-grade intraepithelial neoplasia (HGIN) in nine (23%) lesions, low-grade intraepithelial neoplasia (LGIN) in 22 (55%), pharyngitis in seven (18%) and papilloma in two (5%). Two NBI-ME findings, high microvascular density (MVD) and a brownish area (BA), were recognized more frequently as the grade of malignancy advanced. The likelihood ratio (confidential interval) for having HGIN in the patients with both MVD and BA was 13 (3.62-127). The pathological diagnosis of abnormal micro-lesions ranged from pharyngitis to HGIN. High MVD and BA may be important findings for grading the malignancy of abnormal micro-lesions.
  Digestive Endoscopy 03/2012; 24(2):100-9. · 1.19 Impact Factor
• Article: Ex vivo pig training model for esophageal endoscopic submucosal dissection (ESD) for endoscopists with experience in gastric ESD.

  Shinwa Tanaka, Yoshinori Morita, Tsuyoshi Fujita, Chika Wakahara, Atsuki Ikeda, Takashi Toyonaga, Takeshi Azuma
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  ABSTRACT: Esophageal endoscopic submucosal dissection (ESD) has developed in recent years because of its high rate of en bloc resection. However, for many endoscopists, technical difficulty and risks of complications are great barriers to performing esophageal ESD. In this study, we developed an original training model for esophageal ESD using isolated pig esophagus and assessed this ex vivo model in endoscopists with experience in gastric ESD. Three endoscopists without experience in esophageal ESD but with some experience in gastric ESD performed esophageal ESD of artificial lesions in 10 consecutive sessions using this ex vivo model. The en bloc resection rate, operation time, number of muscularis propria layer injuries, and presence of perforation were recorded. We evaluated the effectiveness of this training in the three endoscopists by comparing results from the first five sessions (former period) with those from the last five sessions (latter period). All three endoscopists achieved en bloc resections in all trials. In the former period, injury to the muscularis propria layer for each of the three endoscopists occurred a mean of 2.2 (1-3), 0.6 (0-1), and 3.2 (1-6) times, respectively. Perforation occurred in one session performed by one endoscopist. In the latter period, the mean number of muscularis propria layer injuries for each of the three endoscopists decreased to 0.2 (0-1), 0.2 (0-1), and 0.8 (0-2), respectively. The time of operation shortened from 35.0 (25-40), 36.4 (30-50), and 29.8 (23-43) min to 23.0 (16-31), 25.6 (23-28), and 29.2 (21-37) min, respectively. This original ex vivo training model was helpful to endoscopists with experience in gastric ESD in acquiring the basic skills for performing esophageal ESD.
  Surgical Endoscopy 01/2012; 26(6):1579-86. · 4.01 Impact Factor
• Article: Inhibitory effects of vitamin K₃ derivatives on DNA polymerase and inflammatory activity.

  Aoganghua Aoganghua, Shin Nishiumi, Kazuki Kobayashi, Masayuki Nishida, Kouji Kuramochi, Kazunori Tsubaki, Midori Hirai, Shinwa Tanaka, Takeshi Azuma, Hiromi Yoshida, Yoshiyuki Mizushina, Masaru Yoshida
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  ABSTRACT: Previously, we reported that vitamin K₃ (menadione, 2-methyl-1,4-naphthoquinone) (compound 2) inhibits the activity of human mitochondrial DNA polymerase γ (pol γ). In this study, we investigated the inhibitory effects (IEs) of vitamin K3 and its derivatives, such as 1,4-naphthoquinone (compound 1) and 1,2-dimethyl-1,4-naphthoquinone (compound 3), on the activity of mammalian pols. Among compounds 1-3 (10 µM for each), compound 1 was the strongest inhibitor of mammalian pols α and λ, which belong to the B and X pol families, respectively, whereas compound 2 was the strongest inhibitor of human pol γ, a family A pol. However, these compounds did not affect the activity of human pol κ, a family Y pol. As we previously found a positive relationship between pol λ inhibition and anti-inflammatory action, we examined whether these vitamin K₃ derivatives are able to inhibit inflammatory responses. Among the three compounds tested, compound 1 caused the greatest reduction in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced acute inflammation in mouse ears. In addition, in a cell culture system using RAW264.7 mouse macrophages, compound 1 displayed the strongest suppression of tumor necrosis factor (TNF)-α production induced by lipopolysaccharide (LPS). In an in vivo mouse model of LPS-evoked acute inflammation, the intraperitoneal injection of compound 1 into mice suppressed TNF-α production in their peritoneal macrophages and serum. In an in vivo colitis mouse model induced using dextran sulfate sodium (DSS), the vitamin K₃ derivatives markedly suppressed DSS-evoked colitis. In conclusion, this study has identified several vitamin K₃ derivatives, such as compound 1, that are promising anti-inflammatory candidates.
  International Journal of Molecular Medicine 08/2011; 28(6):937-45. · 1.98 Impact Factor
• Article: da Vinci robotic single-incision cholecystectomy and hepatectomy using single-channel GelPort access.

  Maki Sugimoto, Koichi Tanaka, Yuichiro Matsuoka, Mari Man-i, Yoshinori Morita, Shinwa Tanaka, Shoko Fujiwara, Takeshi Azuma
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  ABSTRACT: Minimally invasive surgery including laparoscopic and robotic surgery was recently approved for clinical use in hepatobiliary surgery. The purpose of this article is to evaluate the feasibility and technical aspects of robotic single incision for hepatobiliary surgery using the GelPort laparoscopic system in a preliminary animal study. We performed eight robotic single-incision laparoscopic surgery (SILS) procedures, including four cholecystectomies and four lateral segmentectomy of the liver, in a porcine study using the da Vinci S-HD Surgical System. A single-channel GelPort access was placed through a 2.5-cm single incision for robotic access. A 12-mm camera port, two 8-mm ports for the robotic arms and one 5-mm port for the patient-side assistant were inserted. A Mini Loop Retractor was applied to retract the fundus of the gallbladder. The EndoWrist dissector and grasping forceps was introduced to fine-dissect Calot's triangle. The instruments were crossed to avoid "sword fighting" and clashing of instruments in the abdomen. The cystic duct was divided after double ligation and the gallbladder was removed. Hepatic transection was performed with bipolar Harmonic shears and LigaSure for vascular pedicles. All robotic SILS procedures were completed (8/8, 100%). The cholecystectomies and hepatectomies were safely performed in average operating times of 70 min (±15) and 60 min (±20), respectively, with minimal blood loss. There were no conversions, re-interventions or extension of the skin incision. Robotic hepatobiliary SILS is technically feasible and safe using GelPort as a single-incision access platform. Robotic SILS is becoming established and is enormously advantageous to the patient.
  Journal of hepato-biliary-pancreatic sciences. 07/2011; 18(4):493-8.
• Article: A case of small early gastric cancer that was successfully detected by narrow band imaging magnifying endoscopy.

  Yoshinori Morita, Shoko Fujiwara, Shinwa Tanaka, Takashi Toyonaga, Takeshi Azuma
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  ABSTRACT: Endoscopic diagnosis of gastric cancer is very often made by conventional white light endoscopy and/or by indigo carmine chromoendoscopy. However, with this method it is difficult to detect and demarcate a small lesion affected by inflammation or a biopsy procedure. We considered it is useful for diagnosis of such small cancers to observe a lesion with a magnifying endoscope combined with a narrow band imaging system.
  Digestive Endoscopy 05/2011; 23 Suppl 1:89-91. · 1.19 Impact Factor
• Source

  Available from: kobe-u.ac.jp

  Article: Surveillance after colorectal polypectomy; comparison between Japan and U.S.

  Shinwa Tanaka, Daisuke Obata, Ryo Chinzei, Shiei Yoshida, Tuyoshi Sanuki, Yoshinori Morita, Masaru Yoshida, Tsuyoshi Fujita, Takashi Toyonaga, Hiromu Kutsumi, Hideto Inokuchi, Takeshi Azuma
  [show abstract] [hide abstract]
  ABSTRACT: Recently, early detection and early treatment of the colorectal cancer have been enabled by the improvement of endoscopic diagnosis and introduction of new techniques. In Japan, although Japan Polyp Study is running, there is no standard strategy concerning the post-polypectomy colonoscopic surveillance yet. Post-polypectomy colonoscopic surveillance is so far entrusted to each institute or each gastroenterologist at present. To analyze the present states of the surveillance after polypectomy in Japan, we performed questionary survey and compared them with the results in U.S. and U.S. Multisociety Task Force on colorectal Cancer. A simple random sample of 132 doctors who engaged in a digestive organ disease in plural institutes was obtained. Many doctors recommend surveillance every around 1 year regardless of the kind of the polyp. Doctors in Japan tend to recommend postpolypectomy colonoscopic surveillance more frequently than that recommended U.S. Multisociety Task Force on colorectal Cancer. Furthermore in all types of polyps except for 12 mm tubular adenoma with high grade dysplasia, the majority of doctors in Japan recommend post-polypectomy colonoscopic surveillance more frequently than American doctors. Significant difference was found in surveillance of hyperplastic polyp among doctors with 1 to 5 years experience and those with more than 6 years. It has been shown that surveillance intervals varies substantially in each doctor. The agreement of the surveillance program in Japan is necessary to standardize the strategy for the post-polypectomy surveillance of the colon.
  The Kobe journal of medical sciences 01/2011; 56(5):E204-13.
• Article: Activation of the aryl hydrocarbon receptor induces hepatic steatosis via the upregulation of fatty acid transport.

  Yuki Kawano, Shin Nishiumi, Shinwa Tanaka, Kentaro Nobutani, Akira Miki, Yoshihiko Yano, Yasushi Seo, Hiromu Kutsumi, Hitoshi Ashida, Takeshi Azuma, Masaru Yoshida
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  ABSTRACT: The aryl hydrocarbon receptor (AHR) is a basic helix-loop-helix/Per-ARNT-Sim domain transcription factor, which is activated by various xenobiotic ligands. AHR is known to be abundant in liver tissue and to be associated with hepatic steatosis. However, it has not yet been elucidated how the activation of AHR promotes hepatic steatosis. The aim of this study is to clarify the role of AHR in hepatic steatosis. The intraperitoneal injection of 3-methylcholanthrene (3MC), a potent AHR ligand, into C57BL/6J mice significantly increased the levels of triglycerides and six long-chain monounsaturated fatty acids in the livers of mice, resulting in hepatic microvesicular steatosis. 3MC significantly enhanced the expression level of fatty acid translocase (FAT), a factor regulating the uptake of long-chain fatty acids into hepatocytes, in the liver. In an in vitro experiment using human hepatoma HepG2 cells, 3MC increased the expression level of FAT, and the downregulation of AHR by AHR siRNA led to the suppression of 3MC-induced FAT expression. In addition, the mRNA level of peroxisome proliferator-activated receptor (PPAR) α, an upstream factor of FAT, was increased in the livers of 3MC-treated mice. Taking together, AHR activation induces hepatic microvesicular steatosis by increasing the expression level of FAT.
  Archives of Biochemistry and Biophysics 12/2010; 504(2):221-7. · 2.93 Impact Factor
• Article: Depressed type of inflammatory fibroid polyp of the colon.

  Kazuya Iwamoto, Masanori Sakashita, Takuya Takahashi, Daisuke Obata, Shinwa Tanaka, Masatoshi Fujii, Yoshinori Okabayashi
  International Journal of Colorectal Disease 12/2007; 22(11):1409. · 2.38 Impact Factor
• Article: Multiple gastric ulcers caused by a rice cake as an intragastric foreign body.

  Masatoshi Fujii, Masanori Sakashita, Kunihiko Wakamura, Takahiro Horimatsu, Shinwa Tanaka, Daisuke Obata, Kazuya Iwamoto, Yoshinori Okabayashi
  Journal of Gastroenterology 04/2006; 41(3):282-3. · 4.16 Impact Factor
• Article: [Small aorta syndrome in Japan].

  Minoru Kishi, Akihiko Sakaguchi, Shinwa Tanaka, Kayo Nisiwaki, Takahiro Horimatsu, Akihiko Takeda, Yutaka Oonishi, Takashi Koike, Takashi Hujisawa, Mitsuo Maeda, Takashi Ueda, Yasunari Kawabata, Katsuhumi Miyamoto, Nagamasa Kusumoto
  Nihon Naika Gakkai Zasshi 07/2004; 93(6):1186-8.