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Dive into the research topics where Masahiro Senju is active.

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Featured researches published by Masahiro Senju.


Gut | 1991

Flow cytometric analysis of peripheral blood lymphocytes in ulcerative colitis and Crohn's disease.

Masahiro Senju; Frank Hulstaert; James N. Lowder; Derek P. Jewell

Using two colour immunofluorescence with fluorescein isothiocyanate and phycoerythrin labelled monoclonal antibodies, multi-parameter flow cytometry was used to examine the antigenic characteristics of peripheral blood lymphocytes in whole blood of patients with ulcerative colitis and Crohns disease who were not taking immunosuppressive drugs. The numbers of CD4+ and CD8+ lymphocytes in patients with ulcerative colitis and Crohns disease remained unchanged so that the CD4/CD8 ratio was the same as that of normal control subjects. In Crohns disease there were many activated T cells (CD3+, CD25+). Although natural killer cells in active Crohns disease were lower than in normal control subjects, cytotoxic T lymphocytes, as defined by CD3+, CD16+, did not differ in patients with inflammatory bowel disease compared with normal control subjects. For B cell subsets, there were differences in Leu-1+ B cells, Leu-8+ B cells, Fc epsilon R+B cells (Leu-16+, Leu-20+), and activated B cells (Leu-12+, Leu-21+) between patients with inflammatory bowel disease and normal control subjects. These differences are compatible with local activation of B cells in the inflamed colon.


Digestive Diseases and Sciences | 1991

Two-color immunofluorescence and flow cytometric analysis of lamina propria lymphocyte subsets in ulcerative colitis and Crohn's Disease

Masahiro Senju; K C Wu; Y R Mahida; Derek P. Jewell

By using two-color immunofluorescence with fluorescein isothiocyanate (FITC) and phycoerythrin (PE)-labelled monoclonal antibodies and multiparameter flow cytometry, we investigated lamina propria lymphocyte subsets of patients with ulcerative colitis (UC) and Crohns disease (CD). Leu-3/Leu-2 (CD4/CD8) ratio of lamina propria lymphocytes (LPL) of CD (mean±sd: 1.9±0.8,P<0.01) was significantly decreased compared with controls (3.3±1.1), because of an increased number of CD8+lymphocytes. The majority of lamina propria CD4+cells were CD4+, Leu-8-and CD4+, CD45R-both in controls and IBD tissue. Many lamina propria T lymphocytes were activated, expressing HLA-DR antigen not only in IBD but also in controls. NK cells defined by CD16 and CD 56 (3.0±1.4%,P<0.01) were significantly decreased in patients with UC compared with controls (6.5±3.0%). A low proportion of B cells in the intestinal mucosa expressed Leu-8 antigen and CD23 antigen. The proportion of activated B cells of LPL was high in IBD mucosa as well as normal mucosa. These findings suggest that local activation of B cells leads to the loss of the expression of Leu-8 antigen and CD23.


Gut | 1991

Coexpression of CD4 and CD8 on peripheral blood T cells and lamina propria T cells in inflammatory bowel disease by two colour immunofluorescence and flow cytometric analysis.

Masahiro Senju; K C Wu; Y R Mahida; Derek P. Jewell

Using two colour immunofluorescence with fluorescein isothiocyanate and phycoerythrin labelled monoclonal antibodies and multiparameter flow cytometry, we investigated the coexpression of CD4 and CD8 antigens on peripheral blood lymphocytes and lamina propria lymphocytes of patients with ulcerative colitis and Crohns disease and normal control subjects. Both the absolute number and the proportion of peripheral blood CD4+, CD8+ cells in inflammatory bowel disease were small but significantly increased compared with those in normal control subjects. Peripheral blood lymphocytes activated with phytohaemagglutinin showed appreciably increased coexpression of CD4+, CD8+. These CD4, CD8 positive cells were large and granular. Thus the increased number of peripheral blood CD4+, CD8+ cells in inflammatory bowel disease suggests that chronic immune activation occurs not only in the active state of the disease but also in remission. The proportion of CD4+, CD8+ cells in the lamina propria was greater than in peripheral blood in normal subjects, suggesting chronic immune stimulation of the local immune system. This was also seen in patients with Crohns disease or inactive ulcerative colitis. The proportion of CD4+, CD8+ cells was, however, significantly less in the lamina propria of patients with active ulcerative colitis. Whether this implies a possible defect in mucosal immunoregulation in active ulcerative colitis cannot be determined from these results.


Digestive Diseases and Sciences | 1992

Phenotypic characterization of isolated intraepithelial lymphocytes in patients with ulcerative colitis and normal controls.

P. Hoang; Masahiro Senju; J R Lowes; Derek P. Jewell

A method was developed to isolate colonic intraepithelial lymphocytes in patients with ulcerative colitis (N=8) and normal controls (N=13) in order to characterize their phenotype using a panel of monoclonal antibodies and flow cytometry. In both groups, the majority of the cells are of the CD3+CD8+ phenotype associated with cytotoxic/suppressor function. The CD4/CD8 ratios were similar. Virtually no B cells or macrophages were found. An increase in cells coexpressing the CD3 and HLA-DR molecules and a decrease in natural killer cells (CD3, CD16+CD56+) were found in ulcerative colitis, but this was not significant. There were no differences in the proportions of CD8+ and CD4+ cells expressing the Leu8 antigen between ulcerative colitis and controls. Thus a population of colonic intraepithelial lymphocytes has been isolated and, although they may be functionally different in ulcerative colitis compared with controls, this cannot be explained in terms of phenotypic characteristics.


Journal of Gastroenterology | 1997

Progressive systemic sclerosis associated with primary small cell carcinoma of the stomach

Saburo Shikuwa; Masahiro Senju; Hikaru Tanaka; Miyuki Kusano; Genji Matsuda; Katsuhisa Omagari; Yohei Mizuta; Fuminao Takeshima; Kazuya Makiyama; Masahiro Ito; Ichiro Sekine; Shigeru Kohno

A 64-year-old man with a 5-year history of progressive systemic sclerosis (PSS) was hospitalized because of melena. Radiological and endoscopic examinations showed an ulcerative lesion with sharply demarcated and raised margins in the fornix of the stomach. Tumor markers—serum carcinoembryonic antigen (CEA, 11.3 ng/ml) and neuron-specific enolase (NSE, 38.9 ng/ml) were elevated. Histological examination of endoscopic biopsy specimens (and of necropsy specimens) showed proliferation of atypical small round cells. Immunohistological examination of these cells showed they were positive for epithelial membranous antigen (EMA), and neuron-specific enolase (NSE), but negative for UCHL1, leukocyte common antigen (LCA), anti-leukocyte B-cell (MB1), and antileukocyte T-cell (MT1) antigens. Based on these histological and immunohistological tests, a definite diagnosis of small cell carcinoma of the stomach with PSS was established. Our case is a rare combination of PSS and gastric small cell carcinoma. We also reviewed the literature for the association between PSS and gastric cancer in Japanese patients.


Digestive Endoscopy | 1992

A Case of Cronkhite–Canada Syndrome—With Special Reference to Magnifying Endoscopic Observation of Polyps and Coeliac Angiographic Findings—

Kazuya Makiyama; Seima Iwanaga; Tatsuya Katsumata; Atsushi Fukaumi; Kouki Muta; Minoru Itsuno; Yoshihiko Umene; Masahiro Senju; Ikuo Murata; Kohei Hara

The Cronkhite‐Canada syndrome was diagnosed in a 62 year‐old male in whom the gastrointestinal polyposis and ectodermal change disappeared after treatment with corticosteroids and albumin infusions. The major pathophysiologv of this syndrome is gastrointestinal polyposis. The polyps were examined in detail using a magnifying endoscope and then by spraying methylene blue onto the mucosa. It was shown that the polyps were formed by groups of intestinal glands each dilated by hyperaemia and oedema. Destruction of the dilated glands and opening of a pit at the central region were also observed. These changes were associated with secretion from the pit and it is suggested that this is the mechanism for the protein leakage.


Gastroenterologia Japonica | 1989

Clinical course and magnifying endoscopic findings of fine lesions of the large intestinal mucosa in Crohn's disease.

Kazuya Makiyama; Toshiro Tanaka; Masahiro Senju; Minoru Itsuno; Ikuo Murata; Kohei Hara

Summary“Worm-eaten” appearance (WEA) is a fine lesion of Crohn’s disease observed in apparently normal rectal mucosa by magnifying endoscopy. Magnifying endoscopy has now been performed following application of methylene blue on 37 occasions in 27 patients with Crohn’s disease, and the occurrence of WEA was reviewed in relation to the duration and extent of disease. The frequency of WEA was 75% in patients with a history of less than five years and77% in those who had had the disease for more than five years. In the active stage, the frequency was 85% and 100% respectively, and the degree of WEA also increased. The detection rate of granulomata in regions of WEA was 53% when the clinical history was less than five years and 33% when five years or more. In active disease, granulomata were found in 70% and 67% respectively. The large intestine other than the rectum was reviewed in eight patients with ileitis. WEA and granulomata were observed throughout the large intestine including the cecum, especially when the ileal disease was active.


Journal of Infection and Chemotherapy | 1998

Interferon Alfa-2a Treatment for Chronic Hepatitis C without Cirrhosis and Its Effects on the Incidence of Hepatocellular Carcinoma

Katsuhisa Omagari; Nobuhiro Ikuno; Takeo Imanishi; Kenji Hayashida; Kenichiro Inoue; Masahiro Senju; Norihiko Mori; Toshiro Tanaka; Koji Nakamuta; Hidetoshi Oda; Atsushi Minamino; Kohei Komatsu; Yasuko Nomura; Shigeru Kohno

The aim of interferon treatment for chronic hepatitis C is eradication of the hepatitis C virus during the early stages of the disease to prevent progression to liver cirrhosis or hepatocellular carcinoma. However, the effects of interferon on preventing the development of hepatocellular carcinoma for chronic hepatitis C without cirrhosis remain obscure. We wished to study these effects. In this retrospective study, we followed up 66 patients with chronic hepatitis C who were treated with interferon alfa-2a (total dose 324 to 792 MIU) for an average period of 3 years after treatment. Of these 66 patients, 3 patients developed hepatocellular carcinoma during the follow-up period (range, 0.3 to 2.8 years; yearly incidence 1.5%). All 3 patients were among 27 patients who did not respond to interferon treatment. Of these 3 patients, 1 patient developed liver cirrhosis after interferon treatment, and the histologic staging of the remaining 2 patients before interferon treatment was F3, according to the new Inuyama classification. None of the 18 patients who were complete responders to interferon treatment or the 21 patients with incomplete responses developed hepatocellular carcinoma. Our results suggest that patients with chronic hepatitis C who have no response to interferon treatment and histologically advanced disease should be closely followed up after interferon treatment, although the mechanism of malignant transformation to hepatocellular carcinoma in patients with chronic hepatitis C virus infection is still obscure.


Japanese Journal of Medicine | 1991

Two-color Immunofluorescence and Flow Cytometric Analysis of Peripheral Blood Lymphocyte Subsets in Caucasian and Japanese Healthy Subjects

Masahiro Senju; Kazuya Makiyama; Kohei Hara; Frank Hulstaert; James N. Lowder; Derek P. Jewell


Japanese Journal of Nephrology | 1995

A case of acute renal failure due to ethylene glycol intoxication

Masato Tadokoro; Yoshiyuki Ozono; Kohei Hara; Takashi Taguchi; Takashi Harada; Michiko Ideguchi; Masahiro Senju

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Hara K

Nagasaki University

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