Normal histology of the stomach

Description of the normal gastric mucosa in anatomy education: How many leukocytes are acceptable?

Textbooks covering normal human histology illustrate an allegedly normal gastric mucosa containing significant infiltrates of mononuclear cells in the lamina propria. This standard description seems to conflict with the pathologist's criterion for normality, which specifies only a few or a complete absence of inflammatory cells. Eventually, both anatomists and pathologists face the dilemma: how much infiltrate should their students and medical colleagues be told is acceptable for the gastric mucosa to be classified as normal? Summarizing the suggestions of experts in gastroenterology and our own experience, a simple approach could be to accept no more than five mononuclear and plasma cells per high power field as normal (400-fold magnification with a field area of 0.24 mm² ). The divergence of views on this topic illustrates the need for anatomists and pathologists to find a consensus about the definition of "normal" tissues.

Tissue Engineering for Gastrointestinal and Genitourinary Tracts

The gastrointestinal and genitourinary tracts share several similarities. Primarily, these tissues are composed of hollow structures lined by an epithelium through which materials need to flow with the help of peristalsis brought by muscle contraction. In the case of the gastrointestinal tract, solid or liquid food must circulate to be digested and absorbed and the waste products eliminated. In the case of the urinary tract, the urine produced by the kidneys must flow to the bladder, where it is stored until its elimination from the body. Finally, in the case of the vagina, it must allow the evacuation of blood during menstruation, accommodate the male sexual organ during coitus, and is the natural way to birth a child. The present review describes the anatomy, pathologies, and treatments of such organs, emphasizing tissue engineering strategies.

Age-related alterations of gastric mucosa and estrogen synthesis in rat parietal cells

The stomach has diverse functions other than gastric acid secretion. Multifaceted studies have investigated age-related changes of the gastrointestinal tract. Nevertheless, little is known about estrogen production changes in gastric parietal cells in rats aged over 3 months. We investigated age-related changes in gastric estrogen synthesis and the accompanying changes in liver estrogen receptor from 3 to 24 months. Weights of the body, stomach, and liver increased linearly from 3 to 18 months, then maintained a constant proportion up to 24 months. The gastric mucosa area (in mm²/1 mm muscularis mucosa) showed a constant proportion throughout the rats' life. The population of parietal cells immunostained area with H⁺/K⁺-ATPase decreased gradually with advancing age. Cells that were immunopositive to aromatase antibody were observed at 3-24 months. The expressions of aromatase mRNA and its protein were somewhat lower at 18 and 24 months than at 3 months. The portal venous estradiol concentration at 12 months was 1.5 times higher than that at 3 months, and that at 18 months was a half of that at 3 months. The expression of estrogen receptor mRNA in the liver at 18 and 24 months was about 80% of that at 3 months. Results suggest that the gastric estrogen production declines with aging, and the liver estrogen receptor is also affected accordingly. Simultaneously, the gastric mucosa continues to express aromatase to maintain liver function(s) throughout the animal's life.

Analysis of the Occurrence of Diseases Following Gastrectomy for Early Gastric Cancer: a Nationwide Claims Study

Purpose

Various changes in nutrition, metabolism, immunity, and psychological status occur through multiple mechanisms after gastrectomy. The purpose of this study was to predict disease status after gastrectomy by analyzing diseases pattern that occur or change after gastrectomy.

Materials and Methods

A retrospective cohort study was conducted using nationwide claims data. Patients with gastric cancer who underwent gastrectomy or endoscopic resection were included in the study. Eighteen target diseases were selected and categorized based on their underlying mechanism. The incidence of each target disease was compared by dividing the study sample into those who underwent gastrectomy (cases) and those who underwent endoscopic resection for early gastric cancer (controls). The cases were matched with controls using propensity score matching. Thereafter, Cox proportional hazard models were used to evaluate intergroup differences in disease incidence after gastrectomy.

Results

A total of 97,634 patients who underwent gastrectomy (84,830) or endoscopic resection (12,804) were included. The incidence of cholecystitis (P<0.0001), pancreatitis (P=0.034), acute kidney injury (P=0.0083), anemia (P<0.0001), and inguinal hernia (P=0.0007) were higher after gastrectomy, while incidence of dyslipidemia (P<0.0001), vascular diseases (ischemic heart disease, stroke, and atherosclerosis; P<0.0001, P<0.0001, and P=0.0005), and Parkinson's disease (P=0.0093) were lower after gastrectomy.

Conclusions

This study identifies diseases that may occur after gastrectomy in patients with gastric cancer.

Efficacy of immunohistochemical staining in detecting <em>Helicobacter pylori</em> in Saudi patients with minimal and atypical infection

Gastric Helicobacter pylori infection is diagnosed based on histopathological evaluation of gastric mucosal biopsies, urease test, urea breath test, H. pylori culturing, or direct detection using polymerase chain reaction (PCR). This study aimed to evaluate the efficacy of immunohistochemical (IHC) staining in detecting H. pylori in gastric biopsies from patients with chronic gastritis and minimal or atypical infection. Gastric biopsies from 50 patients with chronic gastritis were subjected to routine haematoxylin and eosin (H-E), modified Giemsa, and IHC staining. The results of staining were compared with those of quantitative real-time PCR (qRT-PCR). The qRT-PCR analysis identified 32 (64%) H. pylori-positive cases, whereas IHC, H-E, and modified Giemsa staining identified 29 (58%), 27 (54%), and 21 (42%) positive cases. The sensitivity of IHC staining (87.50%) was higher than that of H-E (59.38%) and modified Giemsa (43.75%) staining. The specificity of H-E, modified Giemsa, and IHC staining was 55.56%, 61.11%, and 94.44%, respectively. IHC staining exhibited the highest diagnostic accuracy (90%), followed by H-E (58%) and modified Giemsa (50%) staining. Active gastritis, intestinal metaplasia, and lymphoid follicles were detected in 32 (64%), 4 (8%), and 22 (44%) cases, respectively, and all of these cases were H. pylori positive. In contrast to routine H-E and modified Giemsa staining, IHC allows for the accurate H. pylori detection in cases with minimal or atypical infection. Moreover, IHC can be an alternative diagnostic method to qRT-PCR for detection of H. pylori in such cases.

Objective Visual Analog Scale for Biopsy Diagnosis of Helicobacter pylori Infection in Clinical Practice

Historic and current pathology society guidelines recommend using visual gestalt to identify substantial inflammatory cell infiltrate in Helicobacter pylori gastritis, but these scales were subjectively designed. This study aims to objectively investigate the density of inflammation that justifies additional workup for H. pylori infection. We retrospectively identified 2 patient cohorts who had undergone endoscopy with gastric biopsies; 1 with H. pylori infection (n=66), confirmed with a positive stool antigen test and/or Campylobacter-like organism test, and 1 without infection (n=81). Antral and body biopsies were selected from each case, if available, and stained with MUM-1 to highlight mucosal plasma cells. Digital analysis was performed to calculate the number of plasma cells/mm2, termed the "inflammatory score" (IS). Patients with H. pylori infection had an average of 1289 plasma cells/mm2 in the antrum and 835 plasma cells/mm2 in the body, compared with 346 plasma cells/mm2 in the antrum and 178 plasma cells/mm2 in the body in patients without infection. IS cut-off values for a positive infection were 714 plasma cells/mm2 in the antrum and 316 plasma cells/mm2 in the body, with high sensitivities and specificities in both the antrum (92%, 92%) and body (85%, 84%), respectively. A visual analog scale was created to provide a histologic correlate of the observed IS ranges and cut-offs. This practical and objective scale is associated with a high sensitivity and specificity for diagnosing H. pylori infection and justifies moving away from upfront universal H. pylori testing in routine clinical practice.

Biomechanical and microstructural characterisation of the porcine stomach wall: Location- and layer-dependent investigations

The mechanical properties of the stomach wall help to explain its function of storing, mixing, and emptying in health and disease. However, much remains unknown about its mechanical properties, especially regarding regional heterogeneities and wall microstructure. Consequently, the present study aimed to assess regional differences in the mechanical properties and microstructure of the stomach wall. In general, the stomach wall and the different tissue layers exhibited a nonlinear stress-stretch relationship. Regional differences were found in the mechanical response and the microstructure. The highest stresses of the entire stomach wall in longitudinal direction were found in the corpus (201.5 kPa), where food is ground followed by the antrum (73.1 kPa) and the fundus (26.6 kPa). In contrast, the maximum stresses in circumferential direction were 39.7 kPa, 26.2 kPa, and 15.7 kPa for the antrum, fundus, and corpus, respectively. Independent of the fibre orientation and with respect to the biaxial loading direction, partially clear anisotropic responses were detected in the intact wall and the muscular layer. In contrast, the innermost mucosal layer featured isotropic mechanical characteristics. Pronounced layers of circumferential and longitudinal muscle fibres were found in the fundus only, whereas corpus and antrum contained almost exclusively circumferential orientated muscle fibres. This specific stomach structure mirrors functional differences in the fundus as well as corpus and antrum. Within this study, the load transfer mechanisms, connected with these wavy layers but also in total with the stomach wall's microstructure, are discussed. STATEMENT OF SIGNIFICANCE: This article examines for the first time the layer-specific mechanical and histological properties of the stomach wall attending to the location of the sample. Moreover, both mechanical behaviour and microstructure were explicitly match identifying the heterogeneous characteristics of the stomach. On the one hand, the results of this study contribute to the understanding of stomach mechanics and thus to their functional understanding of stomach motility. On the other hand, they are relevant to the fields of constitutive formulation of stomach tissue, whole stomach mechanics, and stomach-derived scaffolds i.e., tissue-engineering grafts.

Ultrasonographic features of presumed gastric wall edema in 14 dogs with pancreatitis

Background

Gastric wall edema has not been reported as a complication of acute pancreatitis in dogs.

Objective

To describe the ultrasonographic features of gastric wall thickening in dogs with acute pancreatitis.

Animals

Fourteen dogs with ultrasonographic evidence and clinical diagnosis of acute pancreatitis, with ultrasonographic evidence of increased gastric wall thickness (>5 mm).

Methods

A retrospective search in the medical records from 2014 to 2016 was performed to identify dogs that had ultrasonographic evidence of acute pancreatitis, that had increased thickness of the gastric wall and that were diagnosed with acute pancreatitis clinically. The gastric wall changes such as thickness, layering appearance, echogenicity, distribution of lesions, and perigastric changes were recorded. Serial ultrasonographic examination and histopathological findings were recorded if available.

Results

Mean gastric wall thickness was 9.9 ± 4.0 mm (SD). A complete loss of wall layering was observed in 2 dogs. Thickening of the submucosal layer was observed in 12 dogs, and 5 of them had concurrent muscularis layer thickening. The echogenicity of thickened submucosal layer was intermediate hyperechoic. Lacy appearances were present within the thickened submucosal layer in 7 dogs and in the muscularis layer of 1 dog. Thickening was focal in 12 dogs and adjacent to the diseased pancreas. Subsequent resolution of gastric wall thickening was observed in 3 dogs (range 3‐28 days) via follow‐up ultrasound. One dog underwent necropsy, and gastric wall edema was confirmed histopathologically.

Conclusions and Clinical Importance

Findings indicated that gastric wall thickening presumably because of edema could be a complication of acute pancreatitis.

Qualitative and Quantitative DNA- and RNA-Based Analysis of the Bacterial Stomach Microbiota in Humans, Mice, and Gerbils

Clinical stomach interventions, such as acid inhibition or bypass surgery, have been linked to fecal microbiota alterations. We demonstrate that the stomach microbiota largely overlaps those of adjacent gastrointestinal locations and identify gradual decreases and increases in the relative abundances of specific bacteria within the stomach, suggesting selective enrichment and depletion. Moreover, similarities between stomach and esophagus samples are proportional to the concentrations of Streptococcus (Firmicutes) in the stomach. The relative abundance of Firmicutes in the stomach, compared to that of Bacteroidetes, is increased in RNA relative to DNA, indicating higher transcriptional activity. Moreover, increased absolute bacterial loads are associated with decreased relative abundance of Firmicutes and higher relative abundance of Bacteroidetes. Our findings characterize the stomach microbiota as influenced by Bacteroidetes influx against a background of transcriptionally more active Firmicutes. Human, mouse, and gerbil stomach microbiotas differ at lower taxonomic levels, which might affect the utility of these model organisms.

Clinical interventions in the stomach have been linked to fecal microbiota alterations, suggesting a function of the stomach in gastrointestinal (GI) homeostasis. We sought to determine the taxonomic bacterial biogeography of the upper GI tract, including different sites within the human stomach (cardia, corpus, and antrum), adjacent upstream (esophagus) and downstream (duodenum) locations, and luminal contents (aspirate), as well as whole-stomach samples from mice and gerbils. Qualitative and quantitative DNA- and RNA-based taxonomic microbiota analyses were combined to study the relationship of relative and absolute bacterial abundances and transcriptionally active bacterial microbiota components in the stomach of humans and mice. Stomach microbiota compositions resembled those of esophagus and duodenum. However, along the descending GI tract, the relative abundances of specific oropharyngeal commensals decreased (Streptococcus) or increased (Rothia mucilaginosa, Porphyromonas, and Lachnospiraceae). Furthermore, the compositional similarity (weighted UniFrac) between stomach aspirates and esophageal biopsy samples increased with gastric Streptococcus relative abundance. In both human aspirate and mouse stomach samples, Firmicutes were more abundant among transcriptionally active bacteria than Bacteroidetes. The relative abundance of Firmicutes in the stomach was negatively correlated and that of Bacteroidetes was positively correlated with absolute bacterial abundance, suggesting a disproportionate increase of Bacteroidetes over Firmicutes at higher bacterial densities. Human, mouse, and gerbil stomach samples showed similarities at higher taxonomic levels but differences at lower taxonomic levels. Our findings suggest selective enrichment and depletion of specific bacterial taxa in the stomach and Firmicutes being transcriptionally more active than Bacteroidetes that increase in relative abundance with total bacterial load.

IMPORTANCE Clinical stomach interventions, such as acid inhibition or bypass surgery, have been linked to fecal microbiota alterations. We demonstrate that the stomach microbiota largely overlaps those of adjacent gastrointestinal locations and identify gradual decreases and increases in the relative abundances of specific bacteria within the stomach, suggesting selective enrichment and depletion. Moreover, similarities between stomach and esophagus samples are proportional to the concentrations of Streptococcus (Firmicutes) in the stomach. The relative abundance of Firmicutes in the stomach, compared to that of Bacteroidetes, is increased in RNA relative to DNA, indicating higher transcriptional activity. Moreover, increased absolute bacterial loads are associated with decreased relative abundance of Firmicutes and higher relative abundance of Bacteroidetes. Our findings characterize the stomach microbiota as influenced by Bacteroidetes influx against a background of transcriptionally more active Firmicutes. Human, mouse, and gerbil stomach microbiotas differ at lower taxonomic levels, which might affect the utility of these model organisms.

Mature gastric chief cells are not required for the development of metaplasia

During human gastric carcinogenesis, intestinal metaplasia is frequently seen in the atrophic stomach. In mice, a distinct type of metaplasia known as spasmolytic polypeptide-expressing metaplasia (SPEM) is found in several inflammatory and genetically engineered models. Given the diversity of long- and short-term models of mouse SPEM, it remains unclear whether all models have a shared or distinct molecular mechanism. The origin of SPEM in mice is presently under debate. It is postulated that stem or progenitor cells acquire genetic alterations that then supply metaplastic cell clones, whereas the possibility of transdifferentiation or dedifferentiation from mature gastric chief cells has also been suggested. In this study, we report that loss of chief cells was sufficient to induce short-term regenerative SPEM-like lesions that originated from chief cell precursors in the gastric neck region. Furthermore, Lgr5⁺ mature chief cells failed to contribute to both short- and long-term metaplasia, whereas isthmus stem and progenitor cells efficiently contributed to long-term metaplasia. Interestingly, multiple administrations of high-dose pulsed tamoxifen induced expansion of Lgr5 expression and Lgr5-CreERT recombination within the isthmus progenitors apart from basal chief cells. Thus we conclude that short-term SPEM represents a regenerative process arising from neck progenitors following chief cell loss, whereas true long-term SPEM originates from isthmus progenitors. Mature gastric chief cells may be dispensable for SPEM development. NEW & NOTEWORTHY Recently, dedifferentiation ability in gastric chief cells during metaplasia development has been proposed. Our findings reveal that lesions that were thought to be acute metaplasia in fact represent normal regeneration supplied from neck lineage and that isthmus stem/progenitors are more responsible for sustained metaplastic changes. Cellular plasticity in gastric chief cells may be more limited than recently highlighted.

The JAK/STAT signaling cascade in gastric carcinoma (Review)

Gastric carcinoma remains one of the most prevalent forms of cancer worldwide, despite the decline in incidence rates, increased awareness of the disease and advancement in treatment strategies. Helicobacter pylori infection, dietary factors, lifestyle influences and various genetic aberrations have been shown to contribute to the development and progression of gastric cancer. Recent studies on the genomic landscape of gastric adenocarcinoma have identified several key signaling molecules, including epidermal growth factor receptor family (ErbB) members, vascular endothelial growth factor receptor family (VEGFR) members and PI3K/Akt/mTOR pathway components, that have been implicated in the molecular pathogenesis of gastric cancers. However, clinical trials with compounds that target these molecules have failed to show a significant improvement in overall survival rates when supplemented with conventional therapies. Therefore, it is essential to identify effective prognostic and/or diagnostic biomarkers and develop molecular targeted therapies. The JAK/STAT cascade is a principal signal transduction pathway in cytokine and growth factor signaling, regulating various cellular processes such as cell proliferation, differentiation, migration and survival. Numerous in vivo and in vitro studies have shown that dysregulated JAK/STAT signaling is a driving force in the pathogenesis of various solid cancers as well as hematopoietic malignancies. Hence, a large number of preclinical and clinical studies of drugs targeting this pathway are currently underway. Notably, aberrant JAK/STAT signaling has also been implicated in gastric cancers. In this review, we focus on the ongoing research on the JAK/STAT cascade in gastric carcinoma and discuss the therapeutic potential of targeting JAK/STAT signaling for the treatment of gastric cancer.

Characterizing variability in in vivo Raman spectra of different anatomical locations in the upper gastrointestinal tract toward cancer detection

Raman spectroscopy is an optical vibrational technology capable of probing biomolecular changes of tissue associated with cancer transformation. This study aimed to characterize in vivo Raman spectroscopic properties of tissues belonging to different anatomical regions in the upper gastrointestinal (GI) tract and explore the implications for early detection of neoplastic lesions during clinical gastroscopy. A novel fiber-optic Raman endoscopy technique was utilized for real-time in vivo tissue Raman measurements of normal esophageal (distal, middle, and proximal), gastric (antrum, body, and cardia) as well as cancerous esophagous and gastric tissues from 107 patients who underwent endoscopic examinations. The non-negativity-constrained least squares minimization coupled with a reference database of Raman active biochemicals (i.e., actin, histones, collagen, DNA, and triolein) was employed for semiquantitative biomolecular modeling of tissue constituents in the upper GI. A total of 1189 in vivo Raman spectra were acquired from different locations in the upper GI. The Raman spectra among the distal, middle, and proximal sites of the esophagus showed no significant interanatomical variability. The interanatomical variability of Raman spectra among normal gastric tissue (antrum, body, and cardia) was subtle compared to cancerous tissue transformation, whereas biomolecular modeling revealed significant differences between the two organs, particularly in the gastroesophageal junction associated with proteins, DNA, and lipids. Cancerous tissues can be identified across interanatomical regions with accuracies of 89.3% [sensitivity of 92.6% (162∕175); specificity of 88.6% (665∕751)], and of 94.7% [sensitivity of 90.9% (30∕33); specificity of 93.9% (216∕230)] in the gastric and esophagus, respectively, using partial least squares-discriminant analysis together with the leave-one tissue site-out, cross validation. This work demonstrates that Raman endoscopy technique has promising clinical potential for real-time, in vivo diagnosis and detection of malignancies in the upper GI at the molecular level.

Primary gastrointestinal tract lymphoma: diagnosis and management of common neoplasms

Primary gastrointestinal lymphoma represents the most common location of extranodal lymphoma. With the bulk of disease manifesting within the gastrointestinal tract and contiguous lymph nodes, many of the lymphomas occurring in the peripheral lymph nodes can also present with primary gastrointestinal tract involvement. Molecular biology has recently enabled significant progress in the diagnosis and management of primary gastrointestinal lymphoma. Herein, we will discuss the major lymphomas affecting the bowel and highlight their key morphological, immunophenotypical and molecular diagnostic attributes. Similarly, in keeping with recent therapeutic advances, we will briefly discuss some important treatment considerations. Thus, this review is intended to offer clinicians and pathologists an overview of primary gastrointestinal lymphomas.

Helicobacter pylori infection stimulates intestinalization of endocrine cells in glandular stomach of Mongolian gerbils

Intestinal metaplasia has been investigated extensively as a possible premalignant condition for stomach cancer but its pathogenesis is still not fully understood. In the present study, we examined the relationship between endocrine and mucous cell marker expression periodically after Helicobacter pylori infection in the Mongolian gerbil model. The numbers of chromogranin A (CgA)-positive, gastrin-positive and gastric inhibitory polypeptide (GIP)-positive cells in H. pylori-infected groups was increased significantly compared with the non-infected case. However, CgA-positive and gastrin-positive cells then decreased from 50 through 100 experimental weeks after H. pylori infection, whereas GIP-positive cells increased. Coexistence of gastrin-positive and GIP-positive cells was detected in the same gastric and intestinal mixed phenotypic glandular-type glands. In conclusion, the endocrine cell phenotype is in line with that of the mucous counterpart in the glands of H. pylori-infected Mongolian gerbil stomach, supporting the concept that development of intestinal metaplasia is due to the abnormal differentiation of a stem cell.

Coexistence of gastric- and intestinal-type endocrine cells in gastric and intestinal mixed intestinal metaplasia of the human stomach

Intestinal metaplasia (IM) in the human stomach has previously been classified into a gastric and intestinal mixed (GI-IM) and a solely intestinal phenotype (I-IM). The phenotypes of mucous and endocrine cells were evaluated in 3034 glandular ducts associated with chronic gastritis. In the pyloric region, the relative expression of gastric endocrine cell markers, such as gastrin and somatostatin, decreased gradually from glandular ducts with only gastric mucous cell phenotype (G type) to GI-IM toward I-IM, while that of the intestinal endocrine cell markers, glicentin, gastric inhibitory polypeptide (GIP), and glucagon-like peptide-1 (GLP-1) was inversely correlated. In the fundic region, gastrin-positive cells emerged in the pseudo-pyloric and GI-IM glands, whereas I-IM glands did not possess any gastrin-positive cells, suggesting the presence of a distinct pathway of intestinalization. Double staining revealed coexistence of gastrin- and GLP-1-positive cells in the same gland and occasionally in the same cell in GI-IM glands. These results suggest that the phenotypes of endocrine cells are in line with those for mucous counterparts and support the concept that all of the different types of mucous and endocrine cells in normal and IM glands might be derived from a single progenitor cell in each gland.

Histologic findings in "ex- Helicobacter pylori" gastric biopsies of pediatric patients

Long-term sequelae of Helicobacter pylori-associated chronic gastritis (HpCG) have been described in adult patients. In the present study we report the histology of gastric mucosa biopsies in 6 asymptomatic pediatric patients (5 male and 1 female; mean age 9.5 years) with previous HpCG. Preceding H. pylori was histologically proved and confirmed by culture, direct visualization, and/or serology before delivering treatment. In 5 of 6 cases the HpCG followed a protracted clinical course, with various therapeutic series needed before H. pylori eradication. Time from final treatment for HpCG to actual biopsy ranged from 3 months to almost 3 years. Gastric mucosa showed mild chronic gastritis with absence of H. pylori organisms (6 of 6), focal loss of gland units with collagenous replacement (6 of 6), serrated foveolae (3 of 6), regenerative changes at elongated glandular necks with cells having enlarged and hyperchromatic nuclei (5 of 6), lymphoid aggregates (2 of 6), and presence of sulfomucins in isolated epithelial cells of glands and foveolae (2 of 6). None of these features were noticed in 10 normal gastric mucosa biopsies used as controls. The referred findings in "ex- H. pylori" pediatric patients may represent very early sequelae from HpCG at this age.

Detection of cardia intestinal metaplasia: do the biopsy number and location matter?

BACKGROUND AND AIM

Presence of intestinal metaplasia in the gastric cardia (cardia intestinal metaplasia, CIM) has been reported in 5-34% of patients undergoing upper endoscopy and is a topic of interest given the rising incidence of cancer in this location. The aim of this article is to determine the prevalence of CIM in biopsies obtained from two separate locations within the gastric cardia.

METHODS

Patients presenting to the endoscopy unit for upper endoscopy for any symptoms were invited to participate in the study. The biopsy protocol included: eight biopsies from the gastric cardia, four from upper cardia (forceps across the squamocolumnar junction), four from lower cardia (within 1 cm of upper cardia), and four each from the gastric body and antrum. All cardia biopsies were stained with hematoxylin and eosin (H&E) and alcian blue at pH 2.5 for the presence of goblet cells and the body/antrum biopsies were stained with Steiner silver stain for Helicobacter pylori detection. In patients testing negative for H. pylori by histology, a serology test was performed.

RESULTS

Sixty-five patients have been evaluated by this protocol; median age 54 yr (range: 34-81 yr), 63 males, 53 Caucasians, and 12 African Americans. The detection of CIM was as follows: upper cardia only, 7, both upper and lower cardia, 5, and lower cardia only, 7. Thus, CIM was detected in 12 patients (18%) in the upper cardia biopsies, in 12 patients (18%) in the lower cardia; overall prevalence of CIM was 29% (19 patients). Fifty-eight percent of CIM patients tested positive for H. pylori by either histology or serology. The addition of serology allowed for the detection of eight additional H. pylori-positive CIM patients.

CONCLUSIONS

The prevalence of CIM in this study was similar (18%, four biopsies) at each location; however, if both locations were considered (eight biopsies), the prevalence increased to 29%. Thus, CIM prevalence may vary depending on the number of biopsies obtained as well as on the location of biopsies. Use of additional testing detects more patients who are H. pylori positive and should be performed if association of CIM with H. pylori is contemplated. Future endoscopic studies of the gastric cardia should specify the location of biopsies, the number of biopsies obtained, and the tests used to diagnose H. pylori.

Review article: prevalence of Barrett's oesophagus and metaplasia at the gastro-oesophageal junction

Barrett's oesophagus, a complication of chronic gastro-oesophageal reflux disease, is the premalignant lesion for oesophageal and gastro-oesophageal junction adenocarcinoma. Described in the 1950s by Norman Barrett, the diagnostic criterion for this lesion has evolved significantly over the last three decades. Endoscopic Barrett's oesophagus requires the recognition of columnar mucosa in the distal oesophagus; documentation of metaplastic tissue is confirmed by random biopsies. Given this changing definition of Barrett's metaplasia, the prevalence rates vary in the literature depending on the diagnostic criteria applied. However, it is generally accepted that approximately 10% of patients with chronic gastro-oesophageal reflux disease will be diagnosed with this condition. There are no population-based studies on the prevalence of Barrett's oesophagus, but emerging data indicate that it may be equally prevalent in asymptomatic individuals. These studies require confirmation. Although the incidence of oesophageal adenocarcinoma is increasing rapidly, it is unclear whether the true incidence of Barrett's oesophagus is increasing at the same time. On the other hand, metaplasia at the gastro-oesophageal junction appears to be distinct from Barrett's oesophagus, is probably not related to chronic gastro-oesophageal reflux disease and is a common finding if routine biopsies are obtained at the gastro-oesophageal junction. This article reviews our current understanding of the diagnosis, definition and prevalence of both of these lesions.

Expression of cytokeratins 7 and 20 in Helicobacter pylori-associated chronic gastritis in children

Helicobacter pylori gastric infection induces structural changes in the gastric epithelium. Among them, variations in the expression of cytokeratins have been reported in adult patients. In the present study, we describe the expression of CK7 and CK20 in gastric samples taken from the antrum in three groups of pediatric patients: (A) Helicobacter pylori-associated chronic gastritis (mean age: 11.4 years); (B) previous H. pylori chronic gastritis patients (mean age: 9.4 years); and (C) controls (mean age: 8.8 years). In all, the presence of sulfomucins was assessed with Alcian blue-periodic acid-Schiff pH 1.0. Immunoreactivity was graded as absent (0), weak (1+), moderate (2+), or intense (3+), in accordance with the intensity of the staining, and its distribution as focal or diffuse. CK7 reactivity was 2+ either focal or diffuse in all group A biopsies. The reactivity was more evident in the cells at the neck of the glands, in the areas with more inflammatory infiltrates, decorating long vertical segments of epithelium. In groups B and C, CK7 reactivity was also focal and 1+ at the cells of the necks of the glands. However, group B presented longer vertical segments of positive cells as compared to group C, and shorter than those of group A. The deeper glandular structures were focally 1+ in both groups. CK20 expression was comparable in all three groups, depicting a 2+ diffuse reactivity at the surface epithelium and interposed pits with absence or focal reactivity at the neck and coiled gland areas. Ki-67 immunostaining paralleled that of the CK7. Staining for sulfated mucosubstances was positive in two of five cases of groups A and B, and in none of the cases of group C. We conclude that: (1) the long segments of CK7-positive glandular necks in H. pylori cases most probably indicate intense regenerative activity during active inflammation; (2) eradication of H. pylori does not warrant ad integrum restitution since long segments of Ki-67+, CK7+ cells at the germinative compartment of the glands (as well as cells with sulfomucins) were still recognizable in ex- H. pylori patients; (3) finally, differing from what happens in adults, children somehow manage to maintain fully differentiated CK20+ superficial epithelium while the H. pylori is in action.

Comparison of different routes of vaccination for eliciting antibody responses in the human stomach

Determination of optimal routes to induce mucosal immune responses locally in the stomach and duodenum are important steps in the development of vaccines against Helicobacter pylori infection. In this study, we immunized H. pylori-infected individuals either nasally or rectally with a model antigen, i.e. cholera toxin B subunit, and compared the immune responses after these routes with the responses after oral or intrajejunal vaccination. Specific antibody levels in serum as well as specific antibody levels and antibody-secreting cells in biopsies from antrum and duodenum were determined by ELISA and ELISPOT methods. In contrast to oral vaccination, nasal and rectal vaccination did not induce significant increases in specific antibody-secreting cells either in the antrum or duodenum. Furthermore, when analyzing the antibody levels in saponin extracted biopsies, intrajejunal vaccination was superior to both nasal and rectal vaccination in inducing antigen-specific IgA levels in the stomach. We conclude that oral vaccination is the optimal route for induction of antigen-specific IgA antibody responses in the stomach and duodenum of humans, while nasal or rectal vaccination is less suitable for this purpose.

Profiling, comparison and validation of gene expression in gastric carcinoma and normal stomach

Gastric carcinoma is the fourth most common cause of cancer death worldwide but its molecular biology is poorly understood. We catalogued the genes expressed in two gastric adenocarcinomas and normal stomach, using serial analysis of gene expression (SAGE), and compared the profiles on-line with other glandular epithelia. Candidates were validated by Northern blotting and immunohistochemistry. A total of 29 480 transcripts, derived from 10 866 genes, were identified. In all, 1% of the genes were differentially expressed (>/=fivefold difference plus P-value </=0.01) between cancers and normal stomach. The most abundant transcripts included ribosomal and mitochondrial proteins, of which most were upregulated in the tumours, as were other widely expressed genes including transcription factors, signalling molecules (serine/threonine protein kinases), thymosin beta 10 and collagenase I. Transcripts abundant in normal stomach were functionally important, including gastrin, immunoglobulin alpha, lysozyme, MUC5, pS2 and pepsinogens, which were among 55 gastric-specific genes. Many transcripts were minimally characterized or new, some cancer-associated genes reflected their intestinal morphology, and some normal gastric genes had previously been considered as pancreatic carcinoma markers. The gastric carcinoma profiles resembled other tumours', supporting the existence of common cancer-associated targets. These data provide a catalogue from which to develop markers for better diagnosis and therapy of gastric carcinoma.

The gastric cardia: to be or not to be?

The origin and biologic significance of cardiac gastric mucosa are controversial. Traditionally, it has been considered native mucosa and part of normal foregut development. It has been recently suggested that cardiac mucosa is present only as a metaplastic response to gastroesophageal reflux disease and therefore always abnormal. We evaluated the esophagogastric junction in 100 pediatric autopsy samples to determine the existence, characteristics, and length of pure cardiac mucosa at different ages. No patient had a history of gastroesophageal reflux disease. Cardiac mucosa immediately distal and contiguous to the esophageal squamous mucosa was identified in all 100 samples, varying in length from 0.1 to 3 mm; the mean length was 1 mm. There was an inverse correlation between patient age and length of cardiac mucosa; gender had no influence on measured length. Three patients had mild to moderate histologic esophagitis; two had gastritis. No metaplastic features or Helicobacter pylori were identified. These findings support the concept that there is a normal, variably narrow developmental zone at the esophagogastric junction covered by cardiac mucosa and is present at birth. When cardiac type mucosa is found in biopsy material, it does not necessarily represent evidence of a mucosal metaplastic response to gastroesophageal reflux disease.

Inflammation at the cardio-oesophageal junction: relationship to acid and bile exposure

BACKGROUND

The aetiology of inflammation in cardiac mucosa at the gastro-oesophageal junction (carditis) is unclear, although gastro-oesophageal reflux has been suggested.

OBJECTIVES

To correlate histological features of carditis with oesophageal acid exposure (gastro-oesophageal reflux) and proximal gastric bile exposure (duodenogastric reflux) in patients with symptoms of gastro-oesophageal reflux disease (GORD).

METHODS

Sixty-six patients with reflux symptoms underwent endoscopy with biopsy, oesophageal manometry, 24-h oesophageal pH testing and 24-h proximal gastric Bilitec 2000 testing. Inflammation in glandular mucosa was assessed using the updated Sydney System. Fifteen healthy volunteers underwent pH and Bilitec 2000 testing and served as controls.

RESULTS

There was no correlation between either the presence or histological grade of carditis and oesophageal acid exposure or proximal gastric bilirubin exposure. Patients with reflux symptoms had as much duodenogastric reflux into the proximal stomach as did control subjects.

CONCLUSIONS

We were unable to establish either gastro-oesophageal or duodenogastric reflux as the predominant cause of inflammation in cardiac mucosa.

Carditis is associated with Helicobacter pylori-induced gastritis and not reflux esophagitis

Pathogenesis of chronic inflammation at the gastric cardia is not yet clear. It is controversial whether cardiac-type mucosa is normal structure at the cardiac region. Therefore, we studied the existence of correlations between carditis, infection, and gastroesophageal reflux disease, and determined the prevalence of cardiac mucosa at the endoscopically defined cardiac region. Gastric biopsy specimens were analyzed from 27 patients with reflux esophagitis and 30 subjects without reflux esophagitis. Carditis was not associated with reflux esophagitis, but with infection. Moreover, the degree of gastritis and atrophy at the cardia were closely related to those of the antrum and body. Cardiac mucosa was not always present in the endoscopically defined cardiac region, and its prevalence was positively correlated with gastritis and atrophy grade of the cardia and age. In conclusion, -induced pangastritis may lead to the development of carditis, which is associated with occurrence of cardiac-type mucosa at the cardiac region.

Prevalence of mabDAS-1 positivity in biopsy specimens from the esophagogastric junction

OBJECTIVE

Intestinal metaplasia (IM) is a precursor for malignancies at the esophagogastric junction. A monoclonal antibody, mAbDAS-1, can probably identify cellular characteristics of IM before the appearance of goblet cells. The aim of this study was to examine the prevalence of mAbDAS-1 positivity in biopsies from the squamocolumnar junction (SCJ) and to correlate this positivity with the presence of IM and clinical findings.

METHODS

In 559 patients, reflux symptoms were scored, and the presence of reflux esophagitis and hiatus hernia was evaluated during endoscopy. Two biopsy specimens were obtained from the SCJ. In a subset of patients (n = 99), biopsies from the endoscopically defined cardiac region (2 cm distal to proximal margin of gastric folds) were available. Biopsy specimens were stained with hematoxylin and eosin, Alcian Blue, modified Giemsa, and mAbDAS-1.

RESULTS

mAbDAS-1 positivity was observed in the SCJ biopsies of 201 of 486 (41.4%) patients without IM and in 64 of 73 (87.7%) patients with IM. Patients without IM but with antibody positivity showed similar histological characteristics as patients with IM at the SCJ. Biopsies of 123 of 559 patients (22%) revealed a columnar-cuboidal epithelium, which was found to be mAbDAS-1 positive in 64.2% (77 of 123). Tissue specimens from the cardiac region without IM stained positive in 14.2% (13 of 91), 12 of those also stained at the SCJ.

CONCLUSIONS

In patients without IM, a high prevalence of mAbDAS-1 positivity was observed. Biopsies of these patients showed similar histological characteristics as patients with IM. Although not all patients exhibiting this reactivity may develop IM, mAbDAS-1 reactivity may help in the understanding of the histogenesis of IM at the SCJ.

Immunohistochemical study of neuroendocrine cells at the gastric cardia mucosa

BACKGROUND/AIMS

The gastric cardia mucosa is a narrow band of tissue between the oesophagus and the stomach. The physiological role of this tissue is unknown. This study examined the presence and characteristics of neuroendocrine cells at this site.

METHODS

Biopsy samples were obtained from across normal appearing squamocolumnar junctions. The cardiac mucosa was defined as the presence of special type mucosa composed of mucous secreting glands in the immediate vicinity of oesophageal squamous epithelium. Biopsy specimens were stained with haematoxylin and eosin, alcian blue (pH 2.5) periodic acid Schiff, and modified Giemsa. The chromogranin A and Fontana-Masson stains were used to identify neuroendocrine cells, which were also stained immunohistochemically for gastrin, serotonin, glucagon, pancreatic polypeptide, somatostatin, and vasoactive intestinal peptide.

RESULTS

Chromogranin positive cells were seen in 18 cases with adequate biopsy specimens from the gastric cardia mucosa. These cells were all serotonin positive, but stains for other peptide hormones remained negative. Serotonin positive cells were detected only at the base of foveolae at the periphery of mucous secreting cardiac glands, giving a microscopic appearance resembling that of endocrine cells at the gastric antrum. The presence and numbers of serotonin positive cells did not correlate with chronic inflammation or intestinal metaplasia of the cardiac mucosa. These cells were seen both in Helicobacter pylori positive and negative patients.

CONCLUSIONS

Serotonin positive cells appear to be the sole neuroendocrine cell type at the gastric cardia mucosa. These cells may have a role in regulating the physiology of the gastric cardia mucosa and the lower oesophageal sphincter.

Gastric mucosal atrophy: interobserver consistency using new criteria for classification and grading

BACKGROUND AND AIMS

Considerable difficulties persist amongst pathologists in agreeing on the presence and severity of gastric atrophy. An international group of pathologists pursued the following aims: (i) to generate an acceptable definition and a simple reproducible classification of gastric atrophy; and (ii) to develop guidelines for the recognition of atrophy useful for increasing agreement among observers.

METHODS

After redefining atrophy as the 'loss of appropriate glands' and examining histological samples from different gastric compartments, three categories were identified: (i) negative; (ii) indefinite; (iii) atrophy, with and without intestinalization. Atrophy was graded on a three-level scale. Interobserver reproducibility of the classification was tested by kappa statistics (general and weighted) in a series of 48 cases.

RESULTS

The medians of the general agreement and weighted kappa values were 0.78 and 0.73, respectively. The weighted kappa coefficients, obtained by cross-tabulating the evaluation of each pathologist against all others, were, with only one exception, > 0.4 (moderate to excellent agreement).

CONCLUSIONS

By using the definition of atrophy as the loss of appropriate glands and distinguishing the two main morphological entities of metaplastic and non-metaplastic types, a high level of agreement was achieved by a group of gastrointestinal pathologists trained in different cultural contexts.

Helicobacter pylori associated gastric diseases and lymphoid tissue hyperplasia in gastric antral mucosa

AIM

To investigate the relation between Helicobacter pylori associated gastroduodenal diseases and lymphoid tissue hyperplasia in the antral mucosa and to pursue its evolution after eradication of H pylori.

METHODS

Gastric antral biopsy specimens were obtained from 438 patients with H pylori positive gastroduodenal diseases (185 chronic gastritis, 69 gastric ulcer, and 184 duodenal ulcer) and 50 H pylori negative healthy controls. Lymphoid follicles and aggregates were counted and other pathological features were scored according to the updated Sydney system for classification of chronic gastritis. After a course of anti-H pylori treatment, biopsy specimens were obtained at four to six weeks, 12 months, and 24 months in the chronic gastritis patient group.

RESULTS

The total prevalence of lymphoid follicles and aggregates in the biopsies was 79.9% (350 of 438; 95% confidence intervals (CI), 0.76 to 0.84). The prevalence and density of lymphoid follicles and aggregates were significantly different in the various gastroduodenal diseases. The highest prevalence (89.9%; 95% CI, 0.83 to 0.97) and density (0.82) of lymphoid follicles and aggregates occurred in patients with gastric ulcers. The lowest prevalence of lymphoid follicles and aggregates was found in patients with chronic gastritis (74.6%; 95% CI, 0.68 to 0.81), and the lowest density of lymphoid follicles and aggregates (0.56) was seen in patients with duodenal ulcers. The prevalence and density of lymphoid follicles and aggregates correlated strongly with the activity and severity of gastric antral mucosal inflammation. The eradication of H pylori resulted in a decrease in the prevalence and density of lymphoid follicles and aggregates.

CONCLUSION

The prevalence and density of lymphoid follicles and aggregates in gastric antral mucosal biopsies correlated closely with H pylori infection.

Gastric cardia inflammation: role of Helicobacter pylori infection and symptoms of gastroesophageal reflux disease

OBJECTIVE

Although high prevalences of both chronic inflammation (carditis) and intestinal metaplasia at the gastric cardia have been reported, the pathogenesis is still unclear. This study assesses the role of Helicobacter pylori (H. pylori) infection and symptoms of gastroesophageal reflux disease (GERD) in these histological alterations.

METHODS

Consecutive patients who underwent upper endoscopy were enrolled in the study, irrespective of their symptoms. Patients previously treated for H. pylori infection and those using proton pump inhibitors were excluded. Two biopsies were performed in the antrum, two in the gastric body, and two at the gastric cardia. All biopsies were used to look for H. pylori and for histological assessment.

RESULTS

A total of 133 patients were enrolled. Carditis and intestinal metaplasia at the cardia were detected in 100 (75.2%) and in 18 (13.5%) patients, respectively. The H. pylori infection rate was significantly higher in patients with carditis than in those without it (87/100 vs 7/33; p < 0.0001), and was higher in those with intestinal metaplasia at the cardia than in those without it (17/94 vs 1/39; p = 0.03). Conversely, the prevalence of GERD symptoms was not significantly different between patients with and without carditis (34/100 vs 16/33; p = NS), and between those with and without intestinal metaplasia (5/50 vs 13/83; p = NS). Interestingly, the prevalence of both H. pylori (64/94 vs 39/94; p = 0.0005) and intestinal metaplasia (18/133 vs 4/133; p = 0.0042) in the gastric cardia was significantly higher than that in gastric body.

CONCLUSION

According to our study data, the gastric cardia is frequently infected with H. pylori with consequent development of both carditis and intestinal metaplasia, whereas GERD does not seem to be involved in these histological changes.

Epidemiological, clinical, and histological characteristics of intestinal metaplasia at the oesophagogastric junction compared to short segments of columnar-lined oesophagus

OBJECTIVE

Intestinal metaplasia (IM) close to the oesophagogastric junction (OGJ) has become a focus of research interest against a background of the rising incidence of malignancies in that area. Studies have focused on the presence of IM in short columnar segments (0-3 cm). Recently it has been suggested that IM at the OGJ and IM in short columnar segments may represent different entities. The objective of this current study was to determine the prevalence of IM in these areas and to assess clinical characteristics in order to test the hypothesis that IM at the OGJ and IM in short columnar segments are different entities.

METHODS

Six hundred and fifty-eight patients referred for gastroscopy, in whom a columnar lining of 0-3 cm was found, participated in the study. Endoscopic oesophagitis was graded, distances to endoscopic landmarks were measured, and biopsies (antrum, corpus, 'cardia', and immediately distal to the squamocolumnar junction) were taken. Biopsies were stained with haematoxylin & eosin, Alcian Blue (pH 2.5), modified Giemsa for Helicobacter pylori (Hp), and immunohistochemistry in cases of a negative Giemsa. According to endoscopy, patients were categorized as having a normal OGJ (0-1 cm) or having a short columnar segment (1 -3 cm, tongues >1 cm).

RESULTS

In this study 77.7% of patients had a normal OGJ (IM-positive 15.1%), and 22.3% had a short columnar segment (IM-positive 29.3%). In the first group, IM was correlated with Hp (P = 0.003) and antral IM (P = 0.002), in the second IM was associated with the presence of a hiatal hernia (P < 0.001) and reflux oesophagitis (P = 0.023).

CONCLUSION

These findings suggest that IM at the OGJ is not the same entity as IM in short columnar segments.

The pathological examinations of gastric mucosa in patients with Helicobacter pylori-positive and -negative pernicious anemia

BACKGROUND

The basic histopathological finding in gastric mucosa is chronic atrophic gastritis in patients with pernicious anemia.

MATERIALS AND METHODS

We evaluated the frequency of Helicobacter pylori and pathological examinations of gastric mucosa in pernicious anemia (n = 30) by endoscopical findings and biopsy. The results were compared with gastric mucosa specimens of patients with H. pylori-positive nonulcer dyspepsia (n = 36) and H. pylori-negative nonulcer dyspepsia (n = 21).

RESULTS

H. pylori was diagnosed in 12 patients (40%) with pernicious anemia. Fundal biopsy examinations showed atrophic gastritis in 30 patients (100%), intestinal metaplasia in 13 patients (43.3%), lymphoid follicle in 15 patients (50%), and dysplasia in 6 patients (20%). Antral biopsy examinations showed atrophic gastritis in 8 patients (26.6%), intestinal metaplasia in 8 patients (26.6%), lymphoid follicle in 8 patients (26.6%), and dysplasia in 3 patients (10%). The frequency of fundal inflammation, atrophy, intestinal metaplasia, lymphoid follicle, and dysplasia and antral intestinal metaplasia and mild antral dysplasia were found to be higher in those in the pernicious anemia group than in the nonulcer dyspeptic patients. Antral inflammation, atrophy, and moderate and severe antral dysplasia were found to be higher in those in the nonulcer dyspeptic group.

CONCLUSIONS

Particularly, fundal precancerous lesions were found to be more frequent in patients with pernicious anemia independent of H. pylori.

Sulfomucins in Helicobacter pylori-associated chronic gastritis in children: is this incipient intestinal metaplasia?

BACKGROUND

Little is known about early stages of intestinal metaplastic in chronic gastritis. The purpose of this study was to determine the presence of sulfated mucosubstances hence most probably intestinal metaplasia, in isolated cells of surface gastric pits, and glands in pediatric patients with Helicobacter pylori-associated chronic gastritis.

METHODS

Participants were nine patients (nine different biopsies; mean age 11.5 years, range 3-16 years) with sulfomucin-containing cells evident in the gastric biopsy specimen. Eight of the patients were selected from a group of 15 patients with histologically documented H. pylori-associated chronic gastritis in whom the utility of the Sydney system was being tested.

RESULTS

Symptoms and endoscopic findings of H. pylori-associated chronic gastritis were the same regardless of the presence or absence of sulfomucin-containing cells. On hematoxylin and eosin stained tissues, neither intestinal metaplasia nor atrophy was apparent. However, periodic acid-Schiff (PAS)-alcian blue (pH 1.0) stain revealed the presence of sulfated mucosubstances in isolated cells of gastric pits and glands in the nine patients.

CONCLUSIONS

This finding may represent a "minimal" form of incomplete intestinal metaplasia (type III). Because the nine patients had been untreated, the change is probably reversible. Two follow-up biopsies in patients in whom H. pylori had been treated and eradicated showed absence of sulfated mucins. Although these findings cannot be regarded as fully developed type III intestinal metaplasia, it is possible that left untreated, the alteration may persist and evolve into some other complication. This conclusion justifies follow-up of these patients.

Role of Helicobacter pylori gastritis in gastric atrophy, intestinal metaplasia, and gastric neoplasia

Helicobacter pylori is the major cause of chronic gastritis worldwide. With an estimated rate of infection of over one half of the world's population, it is responsible for extensive morbidity and mortality. Infection with this organism does not appear to spontaneously resolve. Instead it reaches a chronic stage from which a number of outcomes are possible. This article reviews those outcomes that have been linked to H. pylori and explores the pathogenesis while attempting to resolve the discrepant paths infection can take. The associations include duodenal and gastric ulcers and the majority of gastric lymphomas of B-cell type derived from the mucosa-associated lymphoid tissue (MALT). Chronic gastritis has also been shown to evolve into atrophy with intestinal metaplasia in certain populations. This change in the gastric epithelium has been linked with an increased risk of gastric adenocarcinoma. Microsc. Res. Tech. 48:313-320, 2000. Published 2000 Wiley-Liss, Inc.

Classical Barrett esophagus contrasted with Barrett-type epithelium at normal-appearing esophagogastric junction. Central Finland Endoscopy Study Group

BACKGROUND

Incomplete intestinal metaplasia or specialized columnar epithelium (SCE) is the histologic hallmark of Barrett esophagus (BE), but it may also occur at a normal-appearing gastroesophageal junction without BE. We studied whether differences occur between BE patients and those with SCE at the squamocolumnar junction but without BE (abbreviated JSCE), in terms of endoscopic and histologic signs of gastroesophageal reflux disease (GERD) and Helicobacter pylori gastritis.

METHODS

A total of 1059 consecutive patients referred for endoscopy in one hospital district in Finland were enrolled in the study. Biopsy specimens (at least two from each site) were obtained from the gastric antrum and the corpus of the stomach and from the esophagogastric junction and distal esophagus.

RESULTS

Classical BE was detected in 25 (2%) and JSCE in 99 (9%) patients. Dysplasia in the metaplastic mucosa was observed in six BE patients but in none of the JSCE patients (P < 0.001). In multivariate analysis the independent risk factors for BE were endoscopic erosive esophagitis (odds ratio (OR), 6.08; 95% confidence interval (CI), 2.50-14.82), male sex (OR, 3.02; 95% CI, 1.20-7.65), and age (OR, 1.02 per year; 95% CI, 1.00-1.06). The independent risk factors for JSCE were endoscopic erosive esophagitis (OR, 1.88; 95% CI, 1.08-3.29) and age (OR, 1.03; 95% CI, 1.02-1.05) but not H. pylori infection (OR, 1.57; 95% CI, 0.83-2.97) or chronic gastritis (OR, 0.88; 95% CI, 0.44-1.75). In univariate analysis, however, JSCE was associated with antral-predominant atrophic gastritis (77% H. pylori-positive). Unlike in JSCE patients, male sex strongly predominated among BE patients (P = 0.01). The mean ages of BE and JSCE patients did not differ.

CONCLUSIONS

Both BE and JSCE without BE increase in prevalence with age, and both associate with endoscopic erosive esophagitis but not with H. pylori gastritis. However, because of the marked sex disparity, JSCE cannot be a direct precursor of BE, and some factors other than GERD alone also play a role in the pathogenesis of BE. Compared with BE, dysplasia is a rare finding in JSCE, and endoscopic surveillance with biopsy specimens from JSCE patients without dysplasia is not recommended.

Well-differentiated adenocarcinoma, gastric foveolar type, of the extrahepatic bile ducts: A previously unrecognized and distinctive morphologic variant of bile duct carcinoma

Two examples of a rare but distinctive morphologic variant of extremely well-differentiated adenocarcinoma of the extrahepatic bile ducts are reported. One tumor arose in the common bile duct of a 51-year-old man; the other arose in the common hepatic duct of a 27-year-old man. Both tumors were composed predominantly (>95%) of gastric foveolar-type epithelium. Because of their bland nuclear features, low mitotic index, and focal polypoid and lobular architecture, they were initially confused with adenomas. Foci of less-differentiated adenocarcinoma and perineural invasion present in the deep portions of the tumors facilitated recognition. The neoplastic cells and extracellular mucin were periodic acid-Schiff- and alcian blue-positive. By immunohistochemistry, the tumor cells expressed cytokeratins 8 and 20 as well as cathepsin D, as reported in normal foveolar cells. Likewise, p53 overexpression was documented immunohistochemically in both adenocarcinomas, which also stained with the Ki-67 antibody. Despite the well-differentiated nature of the neoplasms and their deceptively benign microscopic appearance, one patient developed recurrence and liver metastasis 5 years after surgery. The other patient is disease-free 2 years following a segmental resection of the common hepatic duct, cystic duct, and gallbladder. The cell phenotype of these tumors can be explained by the ability of the bile duct epithelium to differentiate along gastric cell lines.

Low prevalence of monoclonal B cells in Helicobacter pylori gastritis patients with duodenal ulcer

We have studied the prevalence of B-cell clonality among a large group of 320 patients with Helicobacter pylori gastritis and duodenal ulcer. These patients underwent endoscopic examination with multiple gastric biopsies at diagnosis and were followed 2 and 12 months after therapy. Histopathologic examination of 809 sets of biopsy specimens showed lymphoid gastritis with lymphoid aggregates or follicles, but without lymphoepithelial lesion, in 302 samples corresponding to initial biopsy specimens (n=130) or to posttreatment biopsy specimens (n=172). DNA extracted from fresh antral specimens allowed the amplification of Helicobacter pylori DNA in all cases before therapy. The arrangement of the immunoglobulin heavy chain gene was studied by polymerase chain reaction (PCR) in the 302 selected lymphoid gastritis samples. Single or dominant bands were seen only in four specimens from three patients (1.3%), whereas a polyclonal pattern was seen in the other 298 samples. The detection threshold of our PCR technique was approximately 3% of clonal B cells diluted in a polyclonal population. This threshold appeared to be a reliable cutoff between polyclonal gastritis and clonal MALT lymphoma. In our experience, Helicobacter pylori lymphoid gastritis appeared mainly as a benign polyclonal condition.

Induction of B cell responses in the stomach of Helicobacter pylori- infected subjects after oral cholera vaccination

We have evaluated the possibility of inducing antibody responses locally in the human stomach as a prerequisite for the development of a vaccine against Helicobacter pylori. Both H. pylori-infected and noninfected subjects were immunized with an oral B subunit whole cell (BS-WC) cholera vaccine, and total and vaccine-specific antibody-secreting cells (ASC) were determined by the enzyme-linked immunospot (ELISPOT) technique in cells isolated from the antrum and duodenum, respectively, before and after vaccination. Most of the subjects responded to the vaccination with high frequencies of vaccine-specific ASCs in the duodenum as well as high-serum antibody titers, and no significant differences were seen in the responses between H. pylori- infected and noninfected subjects. When studying the gastric mucosa, on the other hand, there were dramatic differences between the H. pylori-infected and the noninfected subjects. Thus, whereas none of the noninfected subjects responded to the immunization in antrum, most of the H. pylori-infected subjects had high frequencies of vaccine-specific ASCs in this location after vaccination. Furthermore, the H. pylori-infected subjects had strikingly higher (as a mean 80-fold) frequencies of total IgA-secreting cells in antrum than the noninfected subjects, whereas the frequencies of total IgA-secreting cells in the duodenum were comparable between the groups. In conclusion, these results demonstrate the possibility of inducing antibody responses locally in the gastric mucosa of H. pylori-infected individuals, a finding with obvious implications for the future development of a therapeutic vaccine against H. pylori.

Structural changes in the gastric foveolar epithelium in Helicobacter pylori-positive gastritis revealed by keratin immunohistochemistry

To clarify structural changes in the gastric foveolar epithelium in Helicobacter pylori (Hp)-positive gastritis, the expression rates of keratins 8, 18, 19, and 20 were assessed immunohistochemically in normal tissue and chronic gastritis. In normal tissue, keratin 8 was found in 100% of the cells. Staining for keratins 18 and 19 was abundantly positive. Keratin 20 was not expressed in the deep foveolae, but present in the upper foveolae and on the tips. No differences were found between the antrum and the body. In chronic gastritis, both Hp-positive and -negative, keratins 8, 18, and 19 were expressed comparably to normal tissue. Keratin 20 expression in the antrum was significantly lower in Hp-positive compared with Hp-negative gastritis (P < .05) and normal tissue (P < .05). In the body, staining for keratin 20 did not differ significantly between all groups. The difference in keratin 20 expression between the antrum and the body in Hp-positive gastritis was significant (P < .05). After successful eradication, staining for keratin 20 in the antrum normalized within 6 months (P < .05). These findings indicate structural changes in the gastric foveolar epithelium in Hp-positive gastritis. They predominantly include the antral region and show full reversibility after eradication.

Enzyme-histochemical study on postnatal development of rat stomach lymphatic vessels

Postnatal development of rat gastric lymphatics was studied by an enzyme-histochemical method to elucidate the morphological changes of lymphatics and their relationship to maturation and function, especially in the glandular portion. The significant features of 5'-Nase-positive lymphatics in distribution and structure were examined in different stages (within 24 hr, 4-21 days, and 2 months). Lymphatics in the greater curvature and anterior wall grew much slower than those in the lesser curvature and posterior wall of the stomach in newborn and infant rats. Lymphatic islands isolated from the primary lymphatic networks in the submucosa and subserosa underwent a morphological change during this early period. This is considered one of the basic steps in lymphatic development. Occurrence of lymphatic networks in the deep lamina propria indicates that development in the gastric wall is well characterized from Day 10. With further growth and modification of lymphatics, the networks in the different layers formed an extensive communication network and many lymphatic valves were found in the submucosa and subserosa. Pinocytotic vesicles, open junctions, and intraendothelial channels were frequently detected in the mucosal and submucosal lymphatic networks of the corpus-antrum and antrum-duodenum divisional zones in the adult rats. These findings suggest that developing lymphatics in the rat stomach may represent rapidly growing tissue not only with high 5'-Nase activity but also with high adaptability for future physiological demands.

Porcine gastric mucosa associated lymphoid tissue (MALT): stimulation by colonization with the gastric bacterial pathogen, Helicobacter pylori

The presence and features of mucosa associated lymhoid tissue (MALT), analogous to Peyer's patches, in the cardia of the lesser curvature of the porcine stomach are described. The gastric mucosa associated lymphoid tissue (gastric-MALT) is histologically distinct from gastric inflammation associated with colonization by normal gastric microflora and experimental bacterial colonization with a human gastric bacterial pathogen, Helicobacter pylori. The gastric-MALT consists of well-demarcated encapsulated and organized lymphoid tissue, intimately associated with overlying gastric epithelium, centered below the muscularis mucosae and drained by efferent lymphatics. Gastric-MALT was identified in all piglets studied including microbially sterile uninfected gnotobiotes; these structures were enlarged with age and local (gastric) antigenic stimulation. Significant (P < 0.05) expansion of the gastric-MALT occurred in H. pylori-infected gnotobiotic piglets. These distinct morphologic features and location in the cardia suggest that lymphoid elements in the gastric-MALT are involved in gastric antigen processing and regional lymphoid maturation, differentiation and proliferation in the stomach.

Ultrastructural immunogold localization of osteopontin in human gastric mucosa

We performed ultrastructural immunogold localization of osteopontin in the mucosa of human stomach. This adhesive glycoprotein was present in mucous and chief cells of the epithelial layer and in macrophages in the lamina propria. Parietal and endocrine cells of the epithelial layer and mast cells and plasma cells in the lamina propria did not contain osteopontin, serving as internal negative controls. Subcellular localizations of osteopontin included secretory granules and synthetic organelles in mucous and chief cells and phagolysosomes in macrophages. Extracellular concentrations of osteopontin were present in the glycocalyx and in an electron-lucent band between epithelial surface cells and the gastric lumen. Paracellular edema between the epithelium of the same cells was devoid of osteopontin. Immunogold localization of pepsinogen II was done to identify cells with mixed granule populations and contents of multicompartmental secretory granules. These studies revealed mucous cell granules and chief cell granules, each containing compartmentalized storage products, which included osteopontin and mucigen in mucous cells and osteopontin and pepsinogen II in chief cells. Cytochemical controls for the immunogold localizations were negative. The subcellular distribution of osteopontin in human gastric mucosa suggests possible roles for this glycoprotein in barrier function, host defense, and/or secretion.

Immunohistochemical evaluation of keratin 20 expression in intestinal metaplasia types I to III

AIMS

To investigate differences in expression of keratin 20, a cytoskeletal protein in gastrointestinal epithelial cells, in completely differentiated intestinal metaplasia (type I) and incomplete metaplasia (types II and III).

METHODS

Gastric biopsy specimens from 66 patients with intestinal metaplasia were analysed immunohistochemically. Expression of keratin 20 was quantified as the percentage of immunoreactive cells on the tips, the upper, and deep foveolae.

RESULTS

In all specimens keratin 20 was found on the tips and in the upper foveolae of intestinal metaplasia. Keratin 20 was not observed in the deep foveolae. No differences were seen between the antrum and the body. Expression patterns were comparable between types I and III. In type II, however, lower immunoreactivity was found. Both the differences between types I and II as well as between types II and III were significant (p < 0.05).

CONCLUSIONS

Keratin 20 is expressed in metaplastic mucosa as a result of intestinal differentiation. Positive staining found exclusively in juxtaluminal cells occurs only in mature cells containing keratin 20. Lowered immunoreactivity in type II compared with types I and III indicates the different nature of type II intestinal metaplasia. Further studies are needed to shed light on the basic fundamental mechanism responsible for this.

Recognizing atrophy: another step toward a classification of gastritis

The Sydney System is a novel classification of gastritis that attempts to incorporate etiologic, topographic, and morphologic criteria into a clinically relevant scheme. In September of 1994, a group of 20 gastric pathologists from various parts of the world gathered in Houston, Texas, U.S.A., to reappraise the Sydney System 4 years after its introduction and to attempt to reach a broad consensus on gastritis. One of the most controversial issues at the Houston Workshop was the concept of atrophy. Several factors converge to foment confusion and disagreement. "Normal" is imprecisely defined; the loss of glands occurs with distinct patterns and has different functional significance in antrum and corpus; inflammatory infiltrate and lymphoid follicles in the lamina propria may alter the architecture of the gastric mucosa, particularly in the antrum, making loss especially arduous to discern from mere displacement; the relationship between atrophy and intestinal metaplasia remains incompletely understood; and finally, and perhaps most important, the topographic patterns of distribution and the genesis and evolution of atrophic gastritis have been among the most divisive predicaments in the tumultuous arena of gastritis. This article explores some of the difficulties surrounding the concept of atrophy, summarizes the resolutions made at the Houston Workshop, and presents a novel approach to the histopathologic evaluation of atrophic gastritis.

Lectin-binding properties of the antral and body surface mucosa in the human stomach--are the differences relevant for Helicobacter pylori affinity?

Biopsy specimens from histologically normal human gastric mucosa were examined histochemically with the use of lectins. Significant differences were found in the glycoconjugate patterns of the surface mucous cells between the body and the corresponding antrum. Two lectins (Ulex europaeus agglutinin I and Ricinus communis agglutinin I) specific for fucose and galactose residues stained the apical membrane and the intracellular (perinuclear) region of the antral mucosa more strongly than those of the body (P < 0.04). Body and antral biopsies from patients with Helicobacter pylori-positive chronic active gastritis were also studied, but the lectin patterns of Helicobacter pylori-infected body and antrum did not differ. On comparing these chronically infected gastric biopsies with normal antral mucosa, however, significant changes could be seen with the fucose-binding lectin as well as with two other lectins (succinylated concanavalin A and peanut agglutinin). These differences could have been induced directly by bacterial virulence factors or could be due to non-specific reactions to the inflammatory process.

Nuclear receptors for 1,25-dihydroxy-22-oxavitamin D3 (OCT) and 1,25-dihydroxyvitamin D3 in gastric gland neck mucous cells and gastrin enteroendocrine cells

22-Oxacalcitriol the analog with low calcemic effect and the original hormone 1,25(OH)2 vitamin D3 were localized by autoradiography in mouse stomach at different time intervals after intravenous injection. Both compounds showed a distinct nuclear concentration and retention in neck mucous cells of gastric and pyloric glands, and in dispersed endocrine cells in the antrum region. When the nuclear binding of radioactively labelled compound was compared between gastric neck cells and duodenal absorptive cells, binding was low but sustained in neck cells. Peak uptake after the injection was between 8 and 12 h in neck cells, but between 15 min and 30 min in duodenal villous epithelium. In the duodenum, weak nuclear labelling appeared at 8 h and was undetectable at 12 h under the conditions of the experiment. Nuclear labelling of neck cells remained detectable at 12 h and even after 24 h, similarly for both OCT and 1,25(OH)2 vitamin D3. These results suggest that the stomach is an important target tissue for vitamin D and its analog OCT. Regulation of neck cell functions is suggested, such as proliferation and differentiation of surface epithelium and gastric gland epithelium, and neck cell secretion of acidic mucus. Regulation is also indicated of G-cell gastrin secretion associated with gastrin paracrine effects on parietal cell HCl and intrinsic factor secretion, chief cell pepsinogen secretion, neck cell proliferation, as well as endocrine effects on systemic calcium homeostasis.