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Dive into the research topics where Makoto Omi is active.

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Featured researches published by Makoto Omi.


Surgery Today | 2001

Portal Venous Dilatation and Stenting for Bleeding Jejunal Varices: Report of Two Cases

Kei Hiraoka; Satoshi Kondo; Yoshiyasu Ambo; Satoshi Hirano; Makoto Omi; Shunichi Okushiba; Hiroyuki Katoh

Abstract We present two patients who underwent a portal stent placement for bleeding jejunal varices of the afferent loop caused by extrahepatic portal venous stenosis. Case 1 involved a 66-year-old woman who developed bleeding jejunal varices due to extrahepatic portal venous stenosis 1 year after a pancreaticoduodenectomy with intraoperative radiation therapy. Percutaneous transhepatic balloon dilatation and stent placement were performed. Since undergoing the procedure, no bleeding has occurred. Case 2 concerned a 44-year-old woman who had a rupture and bleeding of jejunal varices 16 years after a choledocojejunostomy. Stenosis was observed from the right and left branches of the portal vein to its intrahepatic branches. Both balloon dilatation and stent placement were attempted. However, the stent could not be fully inserted into the intrahepatic portal vein. Portal stent placement is less invasive and radical, and therefore should be attempted for the treatment of extrahepatic portal venous stenosis. However, there are limits to its application if the stenosis extends to the intrahepatic branches of the portal vein.


Surgery Today | 2003

Hand-Assisted Endoscopic Esophagectomy for Esophageal Cancer

Shunichi Okushiba; Koichi Ohno; Kiyotaka Itoh; Hideki Ohkashiwa; Makoto Omi; Kousaku Satou; You Kawarada; Toshiaki Morikawa; Satoshi Kondo; Hiroyuki Katoh

Abstract.Radical esophagectomy is a highly invasive operation for esophageal cancer, and improved techniques are being sought to reduce the invasiveness of this procedure. We devised a method in which an assistant inserts their left hand into the thoracic cavity, and the operator inserts their left hand into the abdominal cavity through a small incision in the upper quadrant during an endoscopic procedure. Between 1996 and 1999, we performed endoscopic esophagectomy on 18 patients. The median number of mediastinal lymph nodes removed by thoracoscopic surgery was 20.1 ± 9.4 and the median number of abdominal lymph nodes removed by laparoscopic surgery was 11.1 ± 5.6. The number of nodes dissected by endoscopic surgery did not differ significantly from the number of nodes dissected by conventional thoracotomy with laparotomy. Our experience shows that endoscopic esophagectomy with reconstruction of the esophagus assisted by inserting the hand into the thoracic and abdominal cavity, for safety and certainty, is an effective technique that is much less invasive than radical esophagectomy performed by conventional thoracotomy with laparotomy.


Pathology International | 2008

Lymphokine-activated killer cytotoxicity against pancreas adenocarcinoma cell lines and vascular endothelial cells.

Hiroshi Sugiura; Hiroshi Ishikura; Makoto Omi; Mitsuhito Kaji; Kazuhiro Iwai; Takashi Kishimoto; Toshiyuki Takahashi; Chisa Kimura; Hiroyuki Kato; Takashi Yoshiki

Eight pancreas carcinoma cell lines of duct cell origin (PCI‐6, 10, 19, 24, 35, 43, 55, and 64) were established. Using one of these lines, PCI‐24, human umbilical vein endothelial cells (HUVEC), and several recombinant cytokines, conditions and specificity of antl‐PCI LAK induction were Investigated, with the focus on a search for lymphokine‐activated killer (LAK) activity that differentiates neoplastic (PCI) from non‐neoplastic (HUVEC) cells. Interferon‐γ (IFN‐γ), IFN‐α, IL‐4, 11–6, and IL‐7, but not tumor necrosis factor‐α (TNF‐α) or IL‐1β, induced a weak LAK activity against PCI‐24, whereas IL‐2‐induced (1000U/mL) LAK exhibited a far more potent cytotoxicity. When these cytokines were added at the suboptimal dose IL‐2 (100U/mL), no significant augmentation in LAK activity was induced. Staphylococcal protein A (SpA) induced LAK activity as potent as that seen with IL‐2 (1000 U/mL). Both IL‐2‐induced and SpA‐induced LAK had a potent, dose‐dependent cytotoxicity against HUVEC. HUVEC inhibited both IL‐2– and SpA‐induced LAK cytotoxicity against PCI‐24 to almost the same extent as seen with PCI‐24. Thus, two potent LAK‐inducers did not generate LAK activity that differentiates neoplastic from non‐neoplastic cells. Thus, in vitro cytotoxicity of LAK agalnst non‐neoplastic endothelial cells is unavoidable when handling cytokines in LAK induction.


Surgery Today | 2000

Nonfunctioning endocrine tumor of the pancreas with extrapancreatic growth and cyst formation: Report of a case

Kentaro Kato; Satoshi Kondo; Yoshiyasu Ambo; Makoto Omi; Satoshi Hirano; Toshiaki Morikawa; Shunichi Okushiba; Hiroyuki Katoh; Miri Fujita; Michio Shimizu

We report a case of nonfunctioning endocrine tumor of the pancreas with extrapancreatic growth and cyst formation. A 48-year-old woman was admitted to our hospital with an upper abdominal mass, which was detected during a routine medical checkup. The preoperative diagnosis was a solid cystic tumor of the pancreas. The tumor, which measured about 7 cm in diameter, arose from the head of the pancreas and had a thin stalk, measuring about 1 cm in diameter. The histopathological diagnosis was a malignant nonfunctioning endocrine tumor of the pancreas. Cyst formation occurred in 67% of the reported cases with extrapancreatic growth in Japan. It is speculated that the cyst formation in this disease is related to the large size of the tumor and to the extrapancreatic growth.


Breast Cancer | 2001

A case of spindle cell carcinoma of the breast-long survival achieved by multiple surgical treatment

Shunichi Okushiba; Hidehiko Minagawa; Michio Shimizu; Yoshiyasu Ambo; Mitsuhito Kaji; Makoto Omi; Kiyotaka Itoh; Satoshi Kondo; Hiroyuki Katoh

Spindle cell carcinoma of the breast was formerly called carcinosarcoma, and is relatively rare. We report a case of spindle cell carcinoma of the breast. The patient was treated with multiple surgeries and achieved long-term survival. The patient was a 52-year-old woman, in whom small induration developed at the areola of the nipple of the right breast. The lesion was resected, and benign tumor was diagnosed pathologically. Four years later, she had recurrence at the scar, and a typical mastectomy was performed. A tumor developed again 5 years later; the lesional focus was at the scar of the right chest wall and invasion of the ribs and the sternum was noted. The sternum and the right costal cartilage of ribs 3–9 were dissected together. The right chest wall was reconstructed and adjuvant radiation therapy performed. Four years after this operation, tumor recurred near the scar and chest wall resection including part of the pericardial cavity and the left lung was performed. However, 6 months later, invasion of the mediastinum, heart and lung were noted. The patient died 16 years after the first surgery. Dermatofibrosarcoma protuberance of the breast was diagnosed at the second operation. However, the diagnosis was changed to spindle cell carcinoma of the breast following immunohistochemical studies. Spindle cell carcinoma of the breast is rare, and definitive histopathological diagnosis is often difficult. When spindle cell carcinoma is suspected, comprehensive diagnostic studies including immunohistochemical examinations should be performed. Even in case with multiple recurrences correctly performed operations may contribute to prolongation of survival.


Pathology Research and Practice | 1996

Interleukin (IL)-6 as a pancreas carcinoma-derived vascular permeability regulator in vitro.

Makoto Omi; Hiroshi Ishikura; Akihiro Ishizu; Toshiyuki Takahashi; Hiroyuki Kato; Takashi Yoshiki

The interaction between pancreas adenocarcinoma and vascular endothelial cells in vitro was investigated. Culture media of pancreas carcinoma cells PCI-10, but not PCI-24, induced an augmented albumin permeability across the endothelial monolayer, an event which was blocked by the calmodulin antagonist, W-7. Only marginal inhibitory effects were obtained using protein kinase inhibitors, H-7 and HA-1004. When cytokine production by pancreas carcinoma cells was examined, production of IL-6 in large amounts by PCI-10, but not by PCI-24 cells was evident. As recombinant IL-6 generated a dose-dependent permeability increase, and as this effect was inhibited by W-7, we considered that the enhancement of vascular permeability was mediated by this cytokine. The activity of culture supernatants for enhanced permeability was almost completely absorbed by the addition of an antibody specific for IL-6. Tumor-derived IL-6 as a soluble mediator regulates vascular permeability in vitro, and the production of this factor by pancreas adenocarcinoma cells presumably modulates biologic behavior.


Surgery Today | 2002

Treatment of Budd-Chiari Syndrome with Percutaneous Transluminal Angioplasty: Report of a Case

Masato Suzuoki; Satoshi Kondo; Yoshiyasu Ambo; Satoshi Hirano; Makoto Omi; Shunichi Okushiba; Hiroyuki Katoh

We report the successful treatment of Budd-Chiari syndrome (BCS) due to an obstruction of the hepatic veins. A 19-year-old man developed bleeding esophageal and gastric varices, and a large amount of ascites was thus caused by portal hypertension. BCS complicated by an obstruction of the major hepatic veins was diagnosed after examinations. We performed percutaneous transluminal angioplasty (PTA). This resulted in a great improvement of BCS, a marked decrease in the pressure of the hepatic veins, and the disappearance of ascites. Restenosis occurred at 1 year and 5 years after the initial angioplasty, for which PTA was repeatedly performed. Nine years after the initial treatment, no stenosis has been observed and the patient has shown a favorable outcome.


Case Reports in Gastroenterology | 2014

Gastrointestinal Obstruction due to Solitary Lymph Node Recurrence of Alpha-Fetoprotein-Producing Gastric Carcinoma with Enteroblastic Differentiation

Takumi Yamabuki; Makoto Omi; Atsuya Yonemori; Kenjiro Misu; Hitoshi Inomata; Yukie Abiko; Michio Mori; Kazuyoshi Nihei

We report an unusual case of alpha-fetoprotein (AFP)-producing gastric carcinoma with enteroblastic differentiation. A 75-year-old woman was admitted to our hospital with occasional upper abdominal discomfort. We performed gastroscopy and observed a type 2 tumor, primarily in the pyloric region. Histological examination of biopsies confirmed gastric adenocarcinoma. Based on these findings, we diagnosed gastric adenocarcinoma and performed laparoscopic distal gastrectomy with lymph node dissection. Histological examination revealed an invasive lesion composed of adenocarcinoma with a tubulopapillary growth pattern. Tumor cells were cuboidal in shape with characteristically clear cytoplasm rich in glycogen. Two regional lymph node metastases were seen microscopically. Immunohistochemically these cells were positive for AFP, carcinoembryonic antigen, caudal-type homeobox transcription factor 2 and common acute lymphoblastic leukemia antigen. The final diagnosis was AFP-producing gastric carcinoma with enteroblastic differentiation. 26 months after initial surgery, the patient was readmitted to our hospital for gastrointestinal obstruction due to lymph node recurrence.


Surgery Today | 2011

Goblet cell carcinoid of the rectum with lymph node metastasis: report of a case.

Takumi Yamabuki; Makoto Omi; Atsuya Yonemori; Satoshi Hayama; Soichi Murakami; Hitoshi Inomata; Michio Mori; Kazuyoshi Nihei

We report an unusual case of goblet cell carcinoid (GCC) of the rectum. A 75-year-old man was admitted to our hospital with anal bleeding, and a hard tumor was felt on the anterior wall of the lower rectum during rectal examination. We performed colonoscopy, and found a 30-mm type 2 tumor in the lower rectum and anal canal. Histological examination of biopsies revealed rectal adenocarcinoma. Based on these findings, we diagnosed rectal adenocarcinoma and performed Miles’ operation with lymph node dissection. Histological examination revealed an invasive lesion composed of signet-ring-like cells. Seven regional lymph node metastases were seen microscopically. The tumor produced copious mucin, which was stained with Alcian blue. Immunohistochemistry was positive for synaptophysin, chromogranin A, CD56, carcinoembryonic antigen, p53, Ki-67, E-cadherin, and cytokeratin 20. The final diagnosis was GCC of the rectum.


Hepato-gastroenterology | 2000

Preoperative embolization of the common hepatic artery in preparation for radical pancreatectomy for pancreas body cancer

Satoshi Kondo; Hiroyuki Katoh; Tadashi Shimizu; Makoto Omi; Satoshi Hirano; Yoshiyasu Ambo; Shunichi Okushiba; Toshiaki Morikawa

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Toshiaki Morikawa

Jikei University School of Medicine

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Michio Shimizu

Saitama Medical University

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