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Featured researches published by Taiji Akamatsu.


The New England Journal of Medicine | 2001

High Serum IgG4 Concentrations in Patients with Sclerosing Pancreatitis

Hideaki Hamano; Shigeyuki Kawa; Akira Horiuchi; Hiroshi Unno; Naoyuki Furuya; Taiji Akamatsu; Mana Fukushima; Toshio Nikaido; Kohzo Nakayama; Nobuteru Usuda; Kendo Kiyosawa

BACKGROUND Sclerosing pancreatitis is a unique form of pancreatitis that is characterized by irregular narrowing of the main pancreatic duct, lymphoplasmacytic inflammation of the pancreas, and hypergammaglobulinemia and that responds to glucocorticoid treatment. Preliminary studies suggested that serum IgG4 concentrations are elevated in this disease but not in other diseases of the pancreas or biliary tract. METHODS We measured serum IgG4 concentrations using single radial immunodiffusion and an enzyme-linked immunosorbent assay in 20 patients with sclerosing pancreatitis, 20 age- and sex-matched normal subjects, and 154 patients with pancreatic cancer, ordinary chronic pancreatitis, primary biliary cirrhosis, primary sclerosing cholangitis, or Sjögrens syndrome. Serum concentrations of immune complexes and the IgG4 subclass of immune complexes were determined by means of an enzyme-linked immunosorbent assay with monoclonal rheumatoid factor. RESULTS The median serum IgG4 concentration in the patients with sclerosing pancreatitis was 663 mg per deciliter (5th and 95th percentiles, 136 and 1150), as compared with 51 mg per deciliter (5th and 95th percentiles, 15 and 128) in normal subjects (P<0.001). The serum IgG4 concentrations in the other groups of patients were similar to those in the normal subjects. In patients with sclerosing pancreatitis, serum concentrations of immune complexes and the IgG4 subclass of immune complexes were significantly higher before glucocorticoid therapy than after four weeks of such therapy. Glucocorticoid therapy induced clinical remissions and significantly decreased serum concentrations of IgG4, immune complexes, and the IgG4 subclass of immune complexes. CONCLUSIONS Patients with sclerosing pancreatitis have high serum IgG4 concentrations, providing a useful means of distinguishing this disorder from other diseases of the pancreas or biliary tract.


Gut | 1997

Histochemistry of the surface mucous gel layer of the human colon

K Matsuo; Hiroyoshi Ota; Taiji Akamatsu; Atsushi Sugiyama; Tsutomu Katsuyama

BACKGROUND AND AIMS: Histochemical analysis of the surface mucous gel layer of the human colon is difficult, as it dissolves in fixatives. This study was undertaken to explore the surface mucous gel layer on the normal mucosa and neoplastic tissues of the large intestine. In addition, the distribution of different mucins secreted from goblet cells was studied with a series of histochemical stains for mucins. METHODS: Twenty four surgically resected specimens were fixed in Carnoys solution and embedded in paraffin. In four cases, the surface mucous gel layer was also studied in frozen sections. Serial sections were stained by a battery of histochemical techniques characterising mucins. RESULTS AND CONCLUSION: The surface mucous gel layer consisted of the inner and outer layers. The first covered the luminal surface of the mucosa, consisted of mucins, and showed a vertical striped pattern. The second overlaid the first, showed a lateral striped pattern, and was contaminated with bacteria and other substances. Their thickness in paraffin sections varied considerably among the sites in the large intestine, but was the thickest in the rectum and measured 12.7 (SEM 6.0) microns and 88.8 (SEM 80.1) microns respectively. Mucins forming the inner layer were obviously derived from goblet cells underlying it.


Cancer | 2002

Patterns of Gastric Atrophy in Intestinal Type Gastric Carcinoma

Hala M. T. El-Zimaity; Hiroyoshi Ota; David Y. Graham; Taiji Akamatsu; Tsutomu Katsuyama

Multifocal atrophic gastritis (MAG) is currently considered a precancerous lesion leading to intestinal type gastric carcinoma. The current study aimed to describe the topography of atrophy in stomachs with early gastric carcinoma.


The American Journal of Gastroenterology | 1998

Characteristic pancreatic duct appearance in autoimmune chronic pancreatitis: A case report and review of the Japanese literature

Akira Horiuchi; Shigeyuki Kawa; Taiji Akamatsu; Yuji Aoki; Kenji Mukawa; Naoyuki Furuya; Yasuhide Ochi; Kendo Kiyosawa

We report a case demonstrating the progressive narrowing of the pancreatic duct, which is presumed to be characteristic of autoimmune pancreatitis, and we review the 37 cases of chronic pancreatitis in which autoimmunity was suggested as an etiological factor in the Japanese literature. A 55-year-old man presented with abdominal discomfort, jaundice, and diffuse swelling of the pancreas on ultrasonography. Serial endoscopic retrograde pancreatography demonstrated the progression of an irregular narrowing of the main pancreatic duct forming diffusely over the course of 2 months. Because the patient had hyperglobulinemia and tested positive for autoantibodies, he was diagnosed as a case of autoimmune chronic pancreatitis. Steroid therapy was carried out with excellent success.


The Journal of Infectious Diseases | 1998

Acquisition versus Loss of Helicobacter pylori Infection in Japan: Results from an 8-Year Birth Cohort Study

Toshiko Kumagai; Hoda M. Malaty; David Y. Graham; Sigemi Hosogaya; Keiko Misawa; Kenichi Furihata; Hiroyoshi Ota; Chizu Sei; Eiji Tanaka; Taiji Akamatsu; Toshiki Shimizu; Kendo Kiyosawa; Tsutomu Katsuyama

Studies of the pattern of change in the epidemiology of Helicobacter pylori infection are scarce. A longitudinal cohort study consisted of 644 children and adults, and two independent cross-sectional surveys were conducted in rural Japan between 1986 and 1994. The anti-H. pylori IgG seroconversion rates were 1.1% and 1% per year for children and adults, respectively. The seroreversion rate per year was 1.8% for children and 1.5% for adults. The cohort study was confirmed by the two cross-sectional studies. H. pylori prevalence fell in all age groups in both children (odds ratio [OR] = 0.5, 95% confidence interval [CI] = 0.2-1.0, P = .05) and adults (OR = 0.4, 95% CI = 0.3-0.6, P = .001). The rate of loss of H. pylori infection was greater than the acquisition. Data regarding acquisition and loss of H. pylori infection are critical to understanding the epidemiology of the infection and to developing treatment and vaccination strategies.


The American Journal of Gastroenterology | 1999

Changes in seroepidemiological pattern of Helicobacter pylori and hepatitis A virus over the last 20 years in Japan

Toru Fujisawa; Toshiko Kumagai; Taiji Akamatsu; Kendo Kiyosawa; Yasuko Matsunaga

OBJECTIVE:The age groups most susceptible to infection and the mode of transmission of Helicobacter pylori (H. pylori) are not yet clear. To contribute to a better understanding of this disease, this study was undertaken to evaluate changes in the seroepidemiological pattern of H. pylori in a group of Japanese people over the last 20 yr sampled in 1974, 1984, and 1994 in comparison with that of the hepatitis A virus (HAV), which was used as a marker of the fecal-oral route of transmission.METHODS:A total of 1015 serum samples were obtained from the National Institute of Infectious Diseases in Tokyo. All of these samples were from healthy persons aged 0–89 yr (442 male and 573 female; median age 35.6 yr), living in seven prefectures in the central part of Japan in 1974, 1984, and 1994. All serum samples were assayed for H. pylori IgG by means of enzyme-linked immunosorbent assay (ELISA). Further, anti-HAV antibodies were assayed by blocking ELISA in the same samples. We investigated the prevalence of H. pylori and HAV for all ages, and the positive rate of H. pylori for infants and children separately.RESULTS:The overall prevalence of H. pylori antibodies was 72.7% (CI 95%, 68.0–77.3) in 1974, 54.6% (CI 95%, 49.1–60.0) in 1984 and 39.3% (CI 95%, 34.1–44.4) in 1994. That of HAV was 57.7% (CI 95%, 52.5–62.8) in 1974, 41.7% (CI 95%, 36.3–47.0) in 1984, and 23.4% (CI 95%, 18.9–27.8) in 1994. The prevalence of both H. pylori and HAV was found to increase with age, whereas there have been clear cohort shifts in the seroepidemiological patterns of both infections over the last 20 yr in Japan. This study shows that there is a slight similarity in the concordance of positive and negative populations between H. pylori and HAV. However, it was very difficult to determine the concordance between H. pylori and HAV infection in this study.CONCLUSIONS:Our data strongly suggest that the highest infection rates for both H. pylori and HAV occur among infants and children in Japan. This study provides evidence that H. pylori and HAV may share a common mode of transmission but that changes in environmental conditions make this very difficult if not impossible to prove with seroepidemiological data.


Helicobacter | 2000

Influence of oral Helicobacter pylori on the success of eradication therapy against gastric Helicobacter pylori.

Hideharu Miyabayashi; Kenichi Furihata; Toshiki Shimizu; Ichirou Ueno; Taiji Akamatsu

Background. The goal of this study was to see whether Helicobacter pylori (H. pylori) in the oral cavity might adversely affect the outcome of eradication therapy for gastric H. pylori.


Journal of Gastroenterology and Hepatology | 1999

Comparing the treatment outcomes of endoscopic papillary dilation and endoscopic sphincterotomy for removal of bile duct stones

Yasuhide Ochi; Kenji Mukawa; Kendo Kiyosawa; Taiji Akamatsu

To compare the clinical usefulness of endoscopic papillary dilation (EPD) and endoscopic sphincterotomy (EST) for removal of bile duct stones, 110 patients with stones up to 15 mm in diameter and less than 10 in number were randomly treated with either EPD (55 patients) or EST (55 patients). The patients were followed up for a median period of 23 months and endoscopic manometry with the administration of morphine was carried out in 17 patients who were observed more than 12 months after the procedures to evaluate the post‐procedure papillary function. Duct clearance was achieved in 51 EPD (92.7%) and 54 EST patients (98.1%, not significantly different). Forty EPD (78.4%) and 51 EST patients (94.4%) achieved duct clearance in the initial procedure (P = 0.02). Early complications occurred in one EPD (2.0%) and in three EST patients (5.6%, P = 0.62). Complications during the follow‐up period occurred in two EPD and eight EST patients. Recurrence of bile duct stones was observed in two EPD and three EST patients (P = 0.98). Acute cholecystitis was observed in one EPD and five EST patients (P = 0.06) and among patients with gall‐bladder stones in situ, the rate of acute cholecystitis after EPD was significantly lower than that after EST (P = 0.03). Endoscopic manometry showed the existence of a choledochoduodenal pressure gradient only after EPD, while papillary contractile function was observed after both procedures. In conclusion, both EPD and EST are safe therapeutic modalities, although EPD is more clinically effective in decreasing the risk of acute cholecystitis in patients with gall‐bladder stones in situ and in preserving post‐procedure papillary function.


The American Journal of Surgical Pathology | 2004

Gastric MALT lymphomas are divided into three groups based on responsiveness to Helicobacter Pylori eradication and detection of API2-MALT1 fusion.

Hiroshi Inagaki; Tsuneya Nakamura; Chunmei Li; Toshiro Sugiyama; Masahiro Asaka; Jyunichi Kodaira; Masahiro Iwano; Tsutomu Chiba; Kazuichi Okazaki; Atsunaga Kato; Ryuzo Ueda; Tadaaki Eimoto; Shiro Okamoto; Naomi Sasaki; Naomi Uemura; Taiji Akamatsu; Hideharu Miyabayashi; Yoko Kawamura; Hidemi Goto; Yasumasa Niwa; Takio Yokoi; Masao Seto; Shigeo Nakamura

Gastric MALT lymphoma shows unique features including regression by Helicobacter pylori eradication and API2-MALT1 fusion. We performed a molecular and clinicopathologic study for 115 cases. All eradication-responsive cases were devoid of API2-MALT1 fusion. All tumors positive for the fusion and all negative for H. pylori infection were nonresponsive to the eradication. Consequently, gastric MALT lymphomas were divided into three groups: Eradication-responsive and fusion-negative (group A, n = 72), eradication-nonresponsive and fusion-negative (group B, n = 22), and eradication-nonresponsive and fusion-positive (group C, n = 21). Group A tumors were characterized by low clinical stage and superficial gastric wall involvement, and group C tumors by low H. pylori infection rate, advanced clinical stage, and nuclear BCL10 expression. All group C tumors showed exclusively low-grade histology. Group B tumors, which have not been well recognized, frequently showed nodal involvement, deep gastric wall involvement, and advanced clinical stage, and sometimes an increased large cell component. A multivariate discriminant analysis revealed that responsiveness to the eradication could be predicted accurately by negative API2-MALT1 fusion, positive H. pylori infection, low clinical stage, and superficial gastric wall invasion, the former being the most important factor for the prediction. This 3-group categorization may be helpful for a comprehensive understanding of gastric MALT lymphoma.


Virchows Archiv | 1998

Helicobacter pylori infection produces reversible glycosylation changes to gastric mucins

Hiroyoshi Ota; Jun Nakayama; Masanobu Momose; Masayoshi Hayama; Taiji Akamatsu; Tsutomu Katsuyama; David Y. Graham; Robert M. Genta

Abstract The protective ability of gastric mucins may depend largely on their oligosaccharide chains. We evaluated the effects of H. pylori infection on the glycosylation of gastric mucins. Gastric biopsy specimens from 20 H. pylori-infected patients before and after cure of the H. pylori infection and 8 normal uninfected volunteers were examined by immunostaining for simple mucin-type glycoproteins and blood-group-related antigens bearing type 1 chain backbone. The immunoreactivity in different gastric compartments was evaluated. Simple mucin-type glycoproteins and blood-group-related antigens were expressed in surface mucous cells. Simple mucin-type glycoproteins showed antrum-predominant expression in normal volunteers and were found in significantly fewer surface mucous cells in infected patients than in normal volunteers; their expression was restored after eradication of H. pylori. Sialyl Lewisa and Lewisb were expressed in fewer surface mucous cells after than before eradication. The patterns of glycosylation of gastric mucins vary in different gastric compartments and are reversibly altered by H. pylori infection. These alterations may affect the protective functions of gastric mucins.

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