Author
Taiji Akamatsu
Bio: Taiji Akamatsu is an academic researcher from Shinshu University. The author has contributed to research in topics: Helicobacter pylori & Gastric mucosa. The author has an hindex of 35, co-authored 148 publications receiving 5901 citations.
Topics: Helicobacter pylori, Gastric mucosa, Stomach, Mucin, Pancreatic disease
Papers published on a yearly basis
Papers
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TL;DR: 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.
Abstract: 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 Sjogren's 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 ...
2,355 citations
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TL;DR: The surface mucous gel layer on the normal mucosa and neoplastic tissues of the large intestine consisted of the inner and outer layers, which were obviously derived from goblet cells underlying it.
Abstract: 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 Carnoy's 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.
270 citations
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TL;DR: The current study aimed to describe the topography of atrophy in stomachs with early gastric carcinoma, which is currently considered a precancerous lesion leading to intestinal type gastric cancer.
Abstract: BACKGROUND. 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. METHODS. Resected stomachs from patients with intestinal type gastric carcinoma were routinely processed, sectioned (an average of 108 sections/stomach), and stained with a triple stain. Sections were scored on a visual analog scale for Heliobacter pylori and intestinal metaplasia. The type of epithelium (antral, oxyntic, transitional) was recorded. Atrophy was defined as the loss of normal glandular components and included intestinal metaplasia and/or pseudo-pyloric metaplasia of the corpus. Pseudo-pyloric metaplasia was identified by the presence of pepsinogen I in mucosa that was topographically corpus but phenotypically antrum. RESULTS. Sixteen stomachs with intestinal type gastric carcinoma were examined. In none of the specimens examined was MAG (independent foci of atrophy) identified. In the majority (88%), atrophy was present as a continuous sheet. Islands of intestinal metaplasia (multifocal intestinal metaplasia) were present within a sheet of pseudo-pyloric metaplasia. A few specimens (12%) had a non-atrophic corpus with almost total replacement of antral epithelium with intestinal metaplasia. Multifocal dysplasia distant from the original tumor was found both in areas with and without intestinal metaplasia. CONCLUSIONS. Contrary to popular belief, atrophy in intestinal type gastric carcinoma is not present as independent foci, but rather as a continuous sheet. Previous studies failed to identify pseudo-pylori metaplasia as a marker for atrophy.
167 citations
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TL;DR: Evidence is provided 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.
149 citations
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TL;DR: The cohort study consisted of 644 children and adults, and two independent cross-sectional surveys were conducted in rural Japan between 1986 and 1994, and the rate of loss of H. pylori infection was greater than the acquisition.
Abstract: 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.
141 citations
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TL;DR: 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.
Abstract: 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 Sjogren's 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 ...
2,355 citations
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TL;DR: This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori, which represents a key factor in the etiology of various gastrointestinal diseases.
Abstract: Helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong. H. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori.
2,246 citations
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Otto-von-Guericke University Magdeburg1, University of Bordeaux2, Trinity College, Dublin3, Erasmus University Medical Center4, University of Bologna5, University of Nottingham6, Veterans Health Administration7, McMaster University8, University of Padua9, Hochschule Hannover10, University of New South Wales11
TL;DR: This fifth edition of the Maastricht Consensus Report describes how experts from 24 countries examined new data related to H. pylori infection in the various clinical scenarios and provided recommendations on the basis of the best available evidence and relevance.
Abstract: Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.
2,219 citations
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TL;DR: In this 4th edition of the Maastricht consensus report aspects related to the clinical role of H pylori were looked at again in 2010, with recommendations to guide doctors involved in the management of this infection associated with various clinical conditions.
Abstract: Management of Helicobacter pylori infection is evolving and in this 4th edition of the Maastricht consensus report aspects related to the clinical role of H pylori were looked at again in 2010. In the 4th Maastricht/Florence Consensus Conference 44 experts from 24 countries took active part and examined key clinical aspects in three subdivided workshops: (1) Indications and contraindications for diagnosis and treatment, focusing on dyspepsia, non-steroidal anti-inflammatory drugs or aspirin use, gastro-oesophageal reflux disease and extraintestinal manifestations of the infection. (2) Diagnostic tests and treatment of infection. (3) Prevention of gastric cancer and other complications. The results of the individual workshops were submitted to a final consensus voting to all participants. Recommendations are provided on the basis of the best current evidence and plausibility to guide doctors involved in the management of this infection associated with various clinical conditions.
2,167 citations
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Harvard University1, University of Cambridge2, Mayo Clinic3, Okayama University4, Technische Universität München5, Dalhousie University6, University of Amsterdam7, Southampton General Hospital8, Tokyo Metropolitan Komagome Hospital9, Shinshu University10, Kanazawa University11, Kanazawa Medical University12, Kansai Medical University13, Seoul National University14, University College London15, Sapporo Medical University16, University of Verona17
TL;DR: This statement proposes a terminology scheme for the diagnosis of IgG4-related disease that is based primarily on the morphological appearance on biopsy, and advocates the use of strict criteria for accepting newly proposed entities or sites as components of the IgG 4- related disease spectrum.
2,041 citations