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Dive into the research topics where Hanzo Kurosaka is active.

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Featured researches published by Hanzo Kurosaka.


Cancer | 1982

Minute gastric cancers less than 5 mm in diameter

Takeshi Oohara; Hiroyuki Tohma; Kazuhide Takezoe; Shiro Ukawa; Yoshiaki Johjima; Reiji Asakura; Giichi Aono; Hanzo Kurosaka

Minute gastric cancers with maximum dimensions of less than 5 mm were studied clinicopathologically. There were 49 intramucosal cancers among 46 patients and nine submucosal cancers among nine patients. No lymph node metastasis was found. Macroscopically, eight (13.8%) were elevated, 12 (20.7%) were flat, and 38 (65.5%) were depressed. Most submucosal cancers were of the depressed type (8/9, 88.9%). Classification of cancers according to association with other large cancers into single group (22 cases) and multiple group (33 cases) revealed that (1) the majority of the minute gastric cancers (20/22, 90.9%) in the single group were the depressed type and (2) submucosal cancers in the single group were 8/22, accounting for 36.4%, a much higher incidence as compared with 1/36 (2.9%) in the multiple group. These facts indicate that gastric cancers should be detected when they are about 5 mm in maximum dimension and before they invade beyond the submucosal layer, especially in single and depressed type.


Neuroreport | 1997

Central effect of melatonin against stress-induced gastric ulcers in rats

Kimitoshi Kato; Ichiro Murai; Satoshi Asai; Sachiko Komuro; Yoshiaki Matsuno; Yoshihiro Matsukawa; Hanzo Kurosaka; Ariyoshi Iwasaki; Koichi Ishikawa; Yasuyuki Arakawa

WE investigated the role of melatonin in the induction of gastric lesions induced by water immersion restraint stress or centrally administered thyrotropin-releasing hormone (TRH). Melatonin (0.1–1 ng) injected intracisternally (i.c.) 30 min prior to stress dose-dependently inhibited the induction of gastric lesions by water immersion restraint stress, while 100 μg/kg, i.p. failed to protect the gastric mucosa. Preadministration of melatonin (1 ng, i.c.) significantly reduced (83%) the severity of gastric lesions induced by a TRH analogue (500 ng, i.c.). Serum melatonin concentrations 30 min after administration of 1 ng melatonin i.c. did not differ from those of rats receiving i.c. vehicle. These results suggest that melatonin plays a protective, anti-stress, role in the gastric mucosa via a mechanism involving the central nervous system.


Cancer | 1984

Clinical diagnosis of minute gastric cancer less than 5 mm in diameter

Takeshi Oohara; Giichi Aono; Shiro Ukawa; Kazuhide Takezoe; Yoshiaki Johjima; Hanzo Kurosaka; Reiji Asakura; Hiroyuki Tohma

When 58 minute gastric cancers less than 5 mm in diameter from 55 patients were classified into 22 of the single group (minute gastric cancer alone) and 36 of the multiple group (associated with other large gastric cancers), the preoperative correct diagnostic rate by x‐ray was 22.7% and 11.1% in the single group and in the multiple group, respectively, with a total rate of 15.5%. The diagnostic rate by endoscopy, aided by endoscopic biopsy, was 95.5%, 13.9%, and 44.8%, respectively. Therefore, it appears that endoscopy and endoscopic biopsy are most efficient diagnostic tools for the detection of such minute gastric cancers. Since the detection of the depressed type (IIc) of minute gastric cancers is considered most significant because of their frequent submucosal invasion, their characteristic endoscopic findings are emphasized: (1) irregular and polygonal shape, (2) distinct depression, (3) clear demarcation, (4) nodular margins, and (5) moth‐eaten appearance and abrupt thinning of the mucosal folds. Cancer 53:162‐165, 1984.


Journal of Gastroenterology and Hepatology | 2006

Oral peppermint oil is a useful antispasmodic for double-contrast barium meal examination

Shigeaki Mizuno; Kimitoshi Kato; Yoshiki Ono; Kiyoshi Yano; Hanzo Kurosaka; Atsuhiko Takahashi; Hiromi Abeta; Toshio Kushiro; Syunpachi Miyamoto; Ryuichi Kurihara; Naoki Hiki; Michio Kaminishi; Ariyoshi Iwasaki; Yasuyuki Arakawa

Background and Aim:  Intraluminally administered peppermint oil (PO) is reportedly a safe and useful antispasmodic for gastroscopy, colonoscopy and double‐contrast barium enema. The aim of this study was to examine the efficacy of oral PO for double‐contrast barium meal examination (DCBM) without other antispasmodics.


Neuroreport | 1998

Central nervous system action of melatonin on gastric acid and pepsin secretion in pylorus-ligated rats

Kimitoshi Kato; Ichiro Murai; Satoshi Asai; Yasuo Takahashi; Yoshiaki Matsuno; Sachiko Komuro; Hanzo Kurosaka; Ariyoshi Iwasaki; Koichi Ishikawa; Yasuyuki Arakawa

We recently demonstrated that centrally administered melatonin at low doses inhibits the induction of gastric lesions by water-immersion restraint stress. To investigate the mechanism of the potent anti-ulcer action of melatonin, the central nervous system (CNS) effects of melatonin on gastric acid and pepsin secretion were studied in conscious pylorus-ligated rats. Intracisternal (i.c.) melatonin (1-100 ng) dose-dependently decreased acid and pepsin output, while a higher i.p. dose (1 microg) had no inhibitory effect. The i.c. melatonin did not change serum gastrin concentrations. Serum melatonin concentrations at 1 and 4 h after i.c. administration of 10-100 ng melatonin did not differ from those in rats receiving i.c. vehicle. The present results suggest that melatonin administered centrally modulates the secretion of gastric acid and pepsin which may explain, at least in part, the protective, anti-stress role of melatonin in the gastric mucosa observed in our previous study.


Journal of Gastroenterology and Hepatology | 2006

Efficacy of peppermint oil as an antispasmodic during endoscopic retrograde cholangiopancreatography

Natsuyo Yamamoto; Yousuke Nakai; Naoki Sasahira; Kenji Hirano; Takeshi Tsujino; Hiroyuki Isayama; Yutaka Komatsu; Mimoru Tada; Haruhiko Yoshida; Takao Kawabe; Naoki Hiki; Michio Kaminishi; Hanzo Kurosaka; Masao Omata

Background:  During endoscopic retrograde cholangiopancreatography (ERCP), hyoscine‐N‐butylbromide (Buscopan) or glucagon is used to inhibit duodenal motility. However, they may cause adverse effects. Peppermint oil has an antispasmodic effect and is used as a less hazardous antispasmodic during colonoscopy and upper gastrointestinal endoscopy. The purpose of the present paper was therefore to investigate peppermint as an antispasmodic for ERCP.


Platelets | 2007

Helicobacter pylori eradication reduces platelet count in patients without idiopathic thrombocytopenic purpura.

Yoshihiro Matsukawa; Kimitoshi Kato; Yoshihiro Hatta; Maho Iwamoto; Shigeaki Mizuno; Ryuichi Kurihara; Yasuyuki Arakawa; Hanzo Kurosaka; Izumi Hayashi; Shigemasa Sawada

Discrepant outcomes of Helicobacter pylori eradication in patients with idiopathic thrombocytopenic purpura have been reported. Here patients with dyspepsia and no other complications underwent gastroendoscopic examination and evaluation for Helicobacter pylori infection. Helicobacter pylori-infected patients with gastritis and gastric ulcer received eradication therapy: lansoprazole (60 mg/day), clarithromycin (400 mg/day), and amoxicillin (1500 mg/day) for 1 week. Lansoprazole 30 mg/day was administrated additional 7 weeks. Peripheral platelets were counted before treatment, 8 weeks after initiation of therapy, and at follow-up periods. Platelet counts in patients with both gastritis and gastric ulcer were evaluated with reference to the presence of Helicobacter pylori infection. Eighty-seven patients with gastritis and 35 of those with gastric ulcer underwent successful eradication therapy. Peripheral platelet counts in patients with gastritis decreased from 235+/−55 to 228+/−58 (103/µL) (p = 0.0337), and those with gastric ulcer decreased from 248+/−60 to 232+/−48 (103/µL) (p = 0.020) 8 weeks after initiation of therapy. Non-eradicated patients did not show such a tendency. Helicobacter pylori eradication reduced peripheral platelet counts in patients with gastritis and gastric ulcer. Amelioration of thrombocytopenia by eradicating Helicobacter pylori appears to involve mechanisms specific to idiopathic thrombocytopenic purpura.


International Journal of Immunopathology and Pharmacology | 2007

Lansoprazole Increases Serum IgG and IgM in H. Pylori-Infected Patients

Yoshihiro Matsukawa; Hanzo Kurosaka; Kimitoshi Kato; I. Hayashi; K. Minekawa; Yasuo Arakawa; Shigemasa Sawada

Proton-pump inhibitors have been reported to influence the human immune system, we therefore evaluated the effect of lansoprazole, a proton-pump inhibitor, on humoral immunity. Patients with gastric ulcer received lansoprazole 30 mg/day for 8 weeks, and serum immunoglobulins were evaluated before and upon completion of the treatment. There were 79 patients with gastric ulcer; 51 were H. pylori-infected and 28 were H. pylori-uninfected. Eighteen patients positive for H. pylori were receiving at least one non-steroidal anti-inflammatory drug, and 12 patients negative for H. pylori received one non-steroidal anti-inflammatory drug. H. pylori-infected patients showed significant increases in serum immunoglobulins G and M 8 weeks after the start of lansoprazole treatment (P<0.001 for IgG and P<005 for IgM), but uninfected patients did not. Even when H. pylori-infected patients receiving a non-steroidal anti-inflammatory drug or low-dose aspirin were analyzed separately, these increases were seen (P<0.001 for IgG and P<0.005 for IgM). Lansoprazole elevated serum levels of immunoglobulins G and M in gastric ulcer patients with H. pylori infection, particularly in those receiving non-steroidal anti-inflammatory drugs. Deducing from these observations, lansoprazole might alter the Th1 shift in the immune response induced by H. pylori infection.


Gastric Cancer | 2006

Helicobacter pylori-negative / API2-MALT1 translocation-negative low-grade MALT lymphoma

Koji Nozaki; Sachiyo Nomura; Nobuyuki Shimizu; Naoki Hiki; Nao Yoshizawa; Susumu Aikou; Keisuke Kubota; Hirokazu Yamaguchi; Hanzo Kurosaka; Aya Shinozaki; Ken-ichi Mafune; Masashi Fukayama; Michio Kaminishi

A 71-year-old man with a Helicobacter pylori infection-negative and API2-MALT1 translocation-negative extranodal marginal-zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type of the stomach has been followed conservatively for over 5 years. The lesion has shown no major morphological changes or malignant progression into a diffuse large-cell type during the time course. The absence of genetic translocation of API2-MALT1 was confirmed with fluorescence in situ hybridization (FISH). The prognosis of H. pylori-negative and API2-MALT1 translocation-negative low-grade MALT lymphoma is unknown, and a standard treatment for such lymphoma has yet to be defined. The case of MALT lymphoma negative for both of the above factors that we report has shown no obvious rapid progression or malignant change over the long-term course. Although curative operation and/or chemoradiotherapy should still be discussed as the treatment of choice, the treatment of this type of lymphoma must be carefully determined on a case-by-case basis, according to its biological status and prognosis.


Gastrointestinal Endoscopy | 1985

Applications of glass filters in gastrofiberscopy

Hanzo Kurosaka; Takeshi Oohara

One of the most important aspects of endoscopy of the gastrointestinal tract is the analysis of color changes in the mucosa, but human color sensitivity is a time-dependent variable.! We attached a glass filter to the eyepiece of an endoscope to minimize the decrease in sensitivity and found that not only was this effective, but also that it simplifed recognition of changes in the color of the gastric mucosa. This report describes (1) the decrease in sensitivity of the human eye to color, (2) the effects of the attachment of a filter to the endoscope, and (3) the practical clinical applications of the system.

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Naoki Hiki

Japanese Foundation for Cancer Research

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