Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Shozo Okamura is active.

Publication


Featured researches published by Shozo Okamura.


Gastrointestinal Endoscopy | 2005

Endoscopic resection of Peutz-Jeghers polyps throughout the small intestine at double-balloon enteroscopy without laparotomy

Naoki Ohmiya; Ayumu Taguchi; Kennosuke Shirai; Nobuyuki Mabuchi; Daigo Arakawa; Hironobu Kanazawa; Masayasu Ozeki; Masahiro Yamada; Masanao Nakamura; Akihiro Itoh; Yoshiki Hirooka; Yasumasa Niwa; Tetsuro Nagasaka; Masafumi Ito; Shinji Ohashi; Shozo Okamura; Hidemi Goto

BACKGROUND Small-bowel enteroscopy with the double-balloon method was developed to improve access to the small intestine. This study evaluated the usefulness of this method for the resection of small-intestinal Peutz-Jeghers polyps. METHODS Two patients with Peutz-Jeghers syndrome underwent nonsurgical double-balloon enteroscopic resection of polyps throughout the small intestine. OBSERVATIONS Multiple polyps in the jejunum were successfully resected via the oral route, as were the polyps in the ileum via the anal route. All 18 polyps (10-60 mm in size) were resected without subsequent bleeding or perforation. Histopathologically, 3 large polyps (>30 mm diameter) were hamartomas with adenomatous components. CONCLUSIONS Double-balloon enteroscopy was safe and useful for the diagnosis and the treatment of Peutz-Jeghers polyps throughout the small intestine. Double-balloon enteroscopic polypectomy might preclude complications of Peutz-Jeghers syndrome, including intussusception, bleeding, and tumorogenesis, thereby obviating the need for multiple laparotomies.


Gut | 1999

The utility of endoscopic ultrasonography and endoscopy in the endoscopic mucosal resection of early gastric cancer

S Ohashi; K Segawa; Shozo Okamura; M Mitake; H Urano; M Shimodaira; T Takeda; S Kanamori; T Naito; K Takeda; B Itoh; Hidemi Goto; Yasumasa Niwa; Tetsuo Hayakawa

OBJECTIVE To clarify the usefulness of endoscopic ultrasonography (EUS) and endoscopy in the endoscopic mucosal resection (EMR) of early gastric cancer.Patients/Methods—EMR was performed in 61 patients with early gastric cancer over the past five years. The accuracy of the assessment of the depth of cancerous invasion was studied in 49 patients who had EUS before EMR. Forty eight patients were treated with endoscopy alone; in these patients, EUS and endoscopic findings correlated with the clinical course. RESULTS Forty six patients showed no changes in the submucosal layer or deeper structures on EUS. Pathologically these included 37 patients with mucosal cancer and nine with submucosal cancer showing very slight submucosal infiltration. Three patients showed diffuse low echo changes in the submucosal layer on EUS; pathologically, these included two with submucosal cancer and one with mucosal cancer with a peptic ulcer scar within the tumour focus. Of 48 patients receiving endoscopic treatment alone, 45 showed no tumour recurrence or evidence of metastases on EUS and endoscopy. Three cases of recurrence were observed. Two of these patients had a surgical gastrectomy, and one was re-treated endoscopically. In the former cases, the surgical results correlated well with assessment by EUS and endoscopy. In addition, the latter patient who was re-treated endoscopically after evaluation with EUS and endoscopy has so far had no recurrence. CONCLUSION The combined use of EUS and endoscopy is effective in diagnosing the depth of cancerous invasion in patients undergoing EMR as well as in clarifying changes both within and between anatomic levels during follow up.


Gut | 2014

The preventive effects of low-dose enteric-coated aspirin tablets on the development of colorectal tumours in Asian patients: a randomised trial

Hideki Ishikawa; Michihiro Mutoh; Sadao Suzuki; Shinkan Tokudome; Yoshihisa Saida; Takashi Abe; Shozo Okamura; Masahiro Tajika; Takashi Joh; Shinji Tanaka; Shin-ei Kudo; Takahisa Matsuda; Masaki Iimuro; Tomomi Yukawa; Tetsuji Takayama; Yasushi Sato; Kyowon Lee; Shinji Kitamura; Motowo Mizuno; Yasushi Sano; Nobuhisa Gondo; Kenji Sugimoto; Masato Kusunoki; Chiho Goto; Nariaki Matsuura; Toshiyuki Sakai; Keiji Wakabayashi

Objective To evaluate the influence of low-dose, enteric-coated aspirin tablets (100 mg/day for 2 years) on colorectal tumour recurrence in Asian patients with single/multiple colorectal tumours excised by endoscopy. Design A double-blinded, randomised, placebo-controlled multicentre clinical trial was conducted. Participants 311 subjects with single/multiple colorectal adenomas and adenocarcinomas excised by endoscopy were enrolled in the study (152 patients in the aspirin group and 159 patients in the placebo group). Enrolment began at the hospitals (n=19) in 2007 and was completed in 2009. Results The subjects treated with aspirin displayed reduced colorectal tumourigenesis and primary endpoints with an adjusted OR of 0.60 (95% CI 0.36 to 0.98) compared with the subjects in the placebo group. Subgroup analysis revealed that subjects who were non-smokers, defined as those who had smoked in the past or who had never smoked, had a marked reduction in the number of recurrent tumours in the aspirin-treated group. The adjusted OR for aspirin treatment in non-smokers was 0.37 (CI 0.21 to 0.68, p<0.05). Interestingly, the use of aspirin in smokers resulted in an increased risk, with an OR of 3.44. In addition, no severe adverse effects were observed in either group. Conclusions Low-dose, enteric-coated aspirin tablets reduced colorectal tumour recurrence in an Asian population. The results are consistent with those obtained from other randomised controlled trials in Western countries. The clinical trial registry website and the clinical trial number http://www.umin.ac.jp (number UMIN000000697).


Gastric Cancer | 2007

Clinicopathological variables associated with lymph node metastasis in submucosal invasive gastric cancer

Shinji Ohashi; Shozo Okamura; Fumihiro Urano; Matsuyoshi Maeda

BackgroundWe aimed to elucidate clinicopathological variables associated with lymph node metastasis of submucosal invasive gastric cancer.MethodsSpecimens were surgically resected from 201 patients who had primary submucosal gastric cancer. We studied 39 consecutive patients with lymph node metastasis and 162 patients without lymph node metastasis. We compared the following clinicopathological characteristics of the patients in relation to lymph node metastasis: age, sex, tumor size, histology, extent of submucosal invasion, lymphatic and venous invasion, and ulceration of the tumor. Submucosal invasion was divided subjectively into sm1, sm2, and sm3 (representing invasion of the upper-, middle-, and lower-third of the submucosa, respectively). We also studied the relationship between lymph node metastasis of submucosal gastric cancer and immunohistochemistry for p53, Ki67, vascular endothelial growth factor (VEGF), α-fetoprotein, sLea, and dendritic cells (DCs).ResultsIn terms of conventional pathological factors, lymph node metastasis in submucosal gastric cancer was related to tumor size (P = 0.002), depth of submucosal invasion (P = 0.001), lymphatic invasion (P < 0.0001), and venous invasion (P = 0.012). Lymph node metastasis in sm1 gastric cancer was significantly related to VEGF expression (P = 0.047). Also, lymph node metastasis in sm3 gastric cancer was significantly correlated with DC expression (P = 0.016). Multivariate analysis showed that tumor size, tumor invasion depth in the submucosal layer, and lymphatic invasion were independent predictors of nodal metastasis in submucosal gastric cancer.ConclusionConventional pathological factors, such as tumor size, depth of submucosal invasion, and lymphatic invasion, have a significant influence on lymph node metastasis. VEGF expression and DC expression may be helpful predictors of lymph node metastasis in patients with sm1 and sm3 gastric cancer, respectively.


Journal of Gastroenterology | 2005

Monozygotic twins concordant for intestinal Behçet's disease.

Taku Kobayashi; Yuichiro Sudo; Shozo Okamura; Shinji Ohashi; Fumihiro Urano; Tsutomu Hosoi; Kose Segawa; Nobuhisa Mizuki; Masao Ota

Although Behçet’s disease (BD) is a multisystem disorder of unknown causes, both genetic and environmental factors have been suggested. This is the second reported case of monozygotic twins concordant for Behçet’s disease and the first such report of intestinal Behçet’s disease. Patient 1 was a 17-year-old man with fever, recurrent oral aphthae, and skin eruptions. He developed hematochezia and was given corticosteroid empirically. One month after he was discharged, he again developed oral ulcerations, fever, and hematochezia. Colonoscopy was performed again, showing aphthous ulcerations in the entire colon, and deep oval ulcers with marginal elevation around the ileocecal valve, which are characteristics of intestinal Behçet’s disease. He was treated with colchicine and azathioprine in combination with salazosulfapyridine (SASP) and prednisolone (PSL) and achieved remission. Patient 2 was the twin brother of patient 1. He was admitted because of oral aphthous ulcerations, fever, pustules on his face and body, and genital ulcers. Two weeks later he developed hematochezia. Colonoscopic and barium enema findings were similar to those of his brother. SASP, PSL, colchicines, and azathioprine were also required to achieve remission. Both of the patients were diagnosed with intestinal Behçet’s disease. Their monozygosity was confirmed by detailed genetic typing, and HLA-B51 was negative.


World Journal of Gastrointestinal Endoscopy | 2017

Analysis of the risk factors for severity in post endoscopic retrograde cholangiopancreatography pancreatitis: The indication of prophylactic treatments

Hiroshi Matsubara; Fumihiro Urano; Yuki Kinoshita; Shozo Okamura; Hiroki Kawashima; Hidemi Goto; Yoshiki Hirooka

AIM To determine the risk factors of severe post endoscopic retrograde cholangiopancreatography pancreatitis (sPEP) and clarify the indication of prophylactic treatments. METHODS At our hospital, endoscopic retrograde cholangiopancreatography (ERCP) was performed on 1507 patients from May 2012 to December 2015. Of these patients, we enrolled all 121 patients that were diagnosed with post endoscopic retrograde PEP. Fourteen of 121 patients diagnosed as sPEP were analyzed. RESULTS Forty-one patients had contrast media remaining in the pancreatic duct after completion of ERCP. Seventy-one patients had abdominal pain within three hours after ERCP. These were significant differences for sPEP (P < 0.05). The median of Body mass index, the median time for ERCP, the median serum amylase level of the next day, past histories including drinking and smoking, past history of pancreatitis, sphincter of Oddi dysfunction, whether emergency or not, expertise of ERCP procedure, diverticulum nearby Vater papilla, whether there was sphincterotomy or papillary balloon dilation, pancreatic duct cannulation, use of intra-ductal ultrasonography enforcement, and transpapillary biopsies had no significant differences with sPEP. CONCLUSION Contrast media remaining in the pancreatic duct and the appearance of abdominal pain within three hours after ERCP were risk factors of sPEP.


Digestive Endoscopy | 2006

CLINICAL MALIGNANCY RISK OF GIST ASSESSED BY ENDOSCOPIC ULTRASONOGRAPHY

Shinji Ohashi; Shozo Okamura; Fumihiro Urano; Matsuyoshi Maeda; Hidemi Goto; Yasumasa Niwa

Background:  The aim of the present study was to analyze clinicopathological findings in primary gastrointestinal stromal cell tumors (GIST) and to determine the clinical factors that indicate higher risk potential.


Blood | 2017

Clinical efficacy of fecal occult blood test and colonoscopy for dasatinib-induced hemorrhagic colitis in CML patients

Satoshi Nishiwaki; Matsuyoshi Maeda; Masahiro Yamada; Shingo Okuno; Yasuhiko Harada; Kotaro Suzuki; Shingo Kurahashi; Fumihiro Urano; Shozo Okamura; Isamu Sugiura

A positive fecal occult blood test (FOBT) is occasionally observed in some chronic myeloid leukemia (CML) patients treated with a tyrosine kinase inhibitor (TKI), and hemorrhagic colitis in patients treated with dasatinib has been reported. To clarify the frequency of TKI-induced hemorrhagic colitis and the screening efficacy of an FOBT followed by a colonoscopy, we prospectively enrolled CML patients treated with a TKI. FOBTs were performed in all patients and colonoscopy was performed in patients with positive FOBTs. When TKI-induced hemorrhagic colitis was pathologically identified, the TKI was interrupted, and the FOBTs were reevaluated. The first FOBT was positive in 10 of 30 patients. All patients with positive FOBTs were treated with dasatinib and developed no symptoms. Dasatinib-induced hemorrhagic colitis was confirmed in 6 of 18 patients treated with dasatinib (33%). Its endoscopic feature was a red flare and/or erosion. Immunohistological analyses showed CD3+, CD8+, CD56+, and Granzyme B+ cytotoxic T lymphocyte infiltration. After dasatinib discontinuation, the FOBTs became negative in all but one patient who had concurrent colorectal polyps. Dasatinib-induced hemorrhagic colitis was observed in one third of asymptomatic patients treated with dasatinib. An FOBT followed by a colonoscopy can be a useful strategy to detect the disease.


Journal of Gastroenterology | 1998

Aggressive non-Hodgkin's lymphoma after successful eradication of Helicobacter pylori and regression of gastric lymphoma of mucosa-associated lymphoid tissue

Shinji Ohashi; Kose Segawa; Shozo Okamura; Masahiro Mitake; Humihiro Urano; Masaya Shimodaira; Shinichi Kanamori; Takehito Naito; Kinichi Takeda; Bunichi Ito; Matsuyoshi Maeda; Toshio Asai

Abstract: A 57-year-old woman presented to our clinic with low-grade gastric lymphoma of mucosa-associated lymphoid tissue (stage IE) and Helicobacter pylori infection. She received a 2-week course of omeprazole and clarithromycin, resulting in eradication of H. pylori and histological disappearance of the lymphoma. However, 9 months later (May 1996), multiple mass lesions were found around the pancreas and hepato-duodenal ligament on abdominal computed tomography. Inguinal lymph node biopsy revealed aggressive nodal type B-cell non-Hodgkins lymphoma, diffuse large cell type. She received chemotherapy with cyclophosphamide, adriamycin, vincristine, and prednisolone, but failed to achieve remission and died in December 1996. There was no evidence of recurrent gastric lymphoma. This case emphasizes the importance of performing follow-up examinations to detect other neoplasms in patients with gastric lymphoma of mucosa-associated lymphoid tissue.


Digestive Endoscopy | 1990

A Clinicopathological Study of IIa +IIc Type Early Colorectal Cancer with Massive Submucosal Invasion

Shozo Okamura; Toshio Asai; Hatsuhiro Yamaguchi; Eiji Hamajima; Tadashi Katoh; Masaya Shimodaira; Hisayoshi Itoh

Abstract: The authors investigated clinical data and pathological findings of eight cases of IIa+IIc type early colorectal cancer which showed minimal invasion in the mucosal laver, but massive invasion in the submucosal layer (deep invasion type). The average age of these 8 patients was 57.8 years (6 out of 8 cases were between 55 and 61‐years‐old). 6 patients were males; 2 were females. Five patients were asymptomatic with a positive reaction for fecal occult blood; the other 2 had anal bleeding. All but 1 patient were diagnosed as having the IIa+IIc type of cancerous lesion, by barium enema examination and colonoscopy. Five patients had lesions in the sigmoid colon, 2 had lesions in the rectum, and 1 had a lesion in the ascending colon. The maximum lesion diameters ranged from 5 to 25 mm, averaging 15.9 mm. Six lesions were less than 20 mm in maximum diameter; 3 of these were less than 10 mm. Pathologically, 5 cases were moderately differentiated adenocarcinoma, 2 were well differentiated adenocarcinoma, and one was poorly differentiated adenocarcinoma. None of the lesions had a coexisting adenomatous component. The incidence of lymph node metastasis was considerably higher than expected (2 out of 8 cases) for early invasive colorectal cancer.

Collaboration


Dive into the Shozo Okamura's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge