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.     

Gastric mucosal superoxide dismutases in Helicobacter pylori infection

BACKGROUND: The mucosal pathology of Helicobacter pylori infection may in part be due to excessive production of reactive oxygen metabolites (ROMs) by phagocytes. The influence of H pylori infection on mucosal superoxide dismutases, some major scavenger enzymes of ROM was investigated. In humans superoxidase dismutase is present in at least two forms-that is, mitochondrial manganese (Mn)-superoxide dismutase and cytoplasmic copper-zinc (CuZn)-superoxide dismutase. METHODS: The amount and activity of both superoxide dismutases were measured, respectively by enzyme linked immunosorbent assay (ELISA) and spectrophotometrical enzyme activity assay, in gastric biopsy homogenates of patients with normal mucosa (n = 39) and in patients with H pylori related gastritis (n = 71). Infection and gastritis were confirmed by a combination of culture, serology, and histology. RESULTS: The amount (p < 0.001) and activity (p < or = 0.05) of Mn-superoxide dismutase were increased by about twofold to three-fold, whereas the amount and activity of CuZn-superoxide dismutase showed a slight decrease in gastric mucosa of patients with H pylori gastritis, in both antrum and corpus, compared with normal mucosa of patients without H pylori infection. Mn-superoxide dismutase concentrations in biopsy specimens of histologically normal corpus from patients with an inflamed antrum were significantly higher (p < 0.01) than that of patients with a histologically normal antrum. CONCLUSION: H pylori infection has a differential effect on mitochondrial and cytoplasmic superoxide dismutase in the gastric mucosa, reflected by a pronounced increase in the cytokine inducible Mn-superoxide dismutase and a marginal decrease in the constitutive CuZn-superoxide dismutase.     

Helicobacter pylori inhibits the secretory activity of gastric parietal cells in patients with chronic gastritis. An ultrastructural study

BACKGROUND: Previous in vitro studies suggested that Helicobacter pylori may inhibit the acid secretion of gastric parietal cells. The aim of this study was to investigate ultrastructurally the influence of H. pylori infection on the gastric parietal cell function in vivo. METHODS: This study comprised 28 patients with chronic gastritis. Biopsy specimens were taken from the gastric body in all cases and examined by electron microscopy. Gastric parietal cells were counted in each ultrathin section and classified into secretory and non-secretory types. The pH of the gastric juice was also measured in all patients. RESULTS: The number of parietal cells in the secretory phase was significantly lower in H. pylori-infected (n = 16) patients than in those (n = 12) without H. pylori infection. The intragastric pH was significantly higher in patients with H. pylori-associated gastritis than in those without H. pylori infection. Parietal cells in secretory phase tended to decrease in proportion to the activity of the gastric mucosal inflammation. CONCLUSIONS: The results of this investigation suggests that H. pylori-associated gastritis is related to a decreased secretory activity of the gastric parietal cells.     

Minimal chronic inactive gastritis: indicator of pre-existing helicobacter pylori gastritis?

Minimal chronic inactive gastritis is regularly observed in routine histopathology. Presently, it is not clear whether this type of gastritis should be regarded as a histopathological entity or a normal variant. The similarity to lesions observed after H.pylori eradication prompted us to look for an association between minimal chronic inactive gastritis and status post H.pylori eradication. In a prospective study of 110 consecutive patients undergoing upper gastrointestinal endoscopy, at least two mucosal biopsies were taken from the gastric antrum and body. Gastritis was classified according to the Sydney System. Antibodies to H.pylori were determined serologically by immunofluorescence test, ELISA, and complement binding reaction. A status post eradication of H.pylori was revealed by medical history and/or positive serology; H.pylori gastritis was found in 39.1%, reactive gastritis in 12.7%, and minimal chronic inactive gastritis in 29.1%. In 19.1% a combination of reactive/ minimal chronic gastritis was diagnosed according to morphology. Status post eradication was observed significantly more often in cases with minimal chronic inactive gastritis (43.8%) than in cases with reactive gastritis (7.1%, p < 0.004). Furthermore, positive ELISA and/or status after eradication was found in 50% of the cases with minimal chronic inactive gastritis (p < 0.005 vs reactive gastritis), in 42.9% of the cases with mixed reactive/chronic inactive gastritis (p < 0.03 vs reactive gastritis), and in 7.1% of the cases with reactive gastritis. Lymphoid aggregates, considered another sign of former H.pylori presence, were found significantly more often in minimal chronic inactive gastritis than in reactive gastritis (50% versus 7.1%, p < 0.005). Minimal chronic inactive gastritis is significantly associated with both positive H.pylori serology and status post eradication and is, therefore, an indicator of pre-existing H.pylori gastritis.     

Detection and effects of helicobacters in healthy dogs and dogs with signs of gastritis

OBJECTIVES: To determine prevalence, colonization density, and distribution of helicobacters and gastric histologic findings in healthy dogs and dogs with signs of gastritis; to evaluate association of colonization density and gastric inflammation; and to compare the number of Helicobacter spp with degree of inflammation. DESIGN: Cross-sectional prevalence survey. ANIMALS: 25 healthy dogs and 21 dogs with signs of gastritis. PROCEDURE: During endoscopy, gastric mucosal biopsy specimens were obtained from healthy and affected client-owned dogs. Histologic and cytologic evaluation and results of a urease test were used for detecting helicobacters, which were identified definitively by use of transmission electron microscopy and bacterial culture. RESULTS: Helicobacters were detected in all 25 healthy and 20 of 21 affected dogs. Cytologic examination was a more sensitive method than histologic examination or the urease test. Helicobacters were found least frequently and in fewest number in the antrum in both groups of dogs. Gastric inflammation was evident in both groups of dogs and did not differ significantly between groups. A significant association was not detected between colonization density or the number of Helicobacter spp and degree of gastric inflammation. In both groups, H bizzozeronii, H felis, and H salomonis were cultured. CLINICAL IMPLICATIONS: Histologically verified chronic gastritis is common in dogs with signs of gastritis as well as in healthy dogs. Colonization density of helicobacters was not associated with degree of gastric inflammation in the dogs of our study. It remains to be determined whether certain strains of Helicobacter spp can induce gastritis in dogs.     

Changes in parietal and mucous cell mass in the gastric mucosa of normal subjects with age: a morphometric study

Whether or not the gastric mucosa undergoes significant changes in normal aging subjects is still open to debate. In 51 subjects undergoing endoscopy and lacking any significant endoscopic or histologic modification we evaluated mucosal thickness, gland number, numbers of parietal, chief and mucous cells at the fundus and of mucopeptic cells at the antrum, with a morphometric method, subgrouping the patients according to their age class. Our findings demonstrate that the number of parietal cells tends to increase with age and, on the other hand, the number of mucous cells is reduced in elderly subjects (p < 0.05). When considering the parietal-to-mucous cell ratio, this is significantly increased (p = 0.0005) with age. Acid secretion being an offensive factor and mucus a fundamental component of the gastric mucosal barrier, these findings suggest an increased susceptibility of the gastric mucosa to damage in the elderly.     

Prevalence of Helicobacter pylori infection and gastric mucosal abnormalities in chronic pancreatitis

OBJECTIVE: Chronic pancreatitis is often associated with abnormal gastric acid secretion. However, previous studies have taken into consideration neither the potential role of Helicobacter pylori (H. pylori) infection nor histological features of the gastric mucosa in this context. The aim of this study was to analyze the prevalence of H. pylori infection as well as the pattern of gastritis in patients with chronic pancreatitis. METHODS: Forty patients with chronic alcoholic pancreatitis were included in the study: 40 patients with alcoholic liver cirrhosis and normal exocrine pancreatic function and 40 asymptomatic nonalcoholic subjects matched for age and sex used as control subjects. Endoscopy was performed in all patients, and five biopsy specimens from the antrum (three from the gastric body and two from the cardia) were taken for histological grading of gastritis and H. pylori assessment. RESULTS: Prevalence of H. pylori infection was similar in subjects with chronic pancreatitis (38%), asymptomatic subjects (28%) and liver cirrhosis (30%). Topography and expression of H. pylori-associated chronic gastritis was also not different among the three groups of subjects. In H. pylori-negative subjects, the presence of moderate to severe chronic antral gastritis was significantly more common in patients with chronic pancreatitis (40%) than in subjects with liver cirrhosis (18%) and in asymptomatic subjects (14%) (p < 0.05). No difference was found among the three groups of patients with regard to gastritis activity, atrophy, and intestinal metaplasia in the various gastric regions. The chronicity grade of gastritis did not correlate with the severity of pancreatic insufficiency. CONCLUSION: Prevalence of H. pylori infection is not different in patients with chronic pancreatitis as compared with subjects alcoholic liver cirrhosis and asymptomatic subjects. A severe H. pylori-negative chronic gastritis is more common in patients with chronic pancreatitis. This chronic inflammation of the gastric mucosa could contribute to determining the changes in gastric physiology described in patients with chronic pancreatitis.     

Is duodenal gastric metaplasia a consequence of Helicobacter pylori infection in children?

BACKGROUND: Duodenal gastric metaplasia (DGM) is commonly found in association with Helicobacter pylori (Hp)-associated gastritis in adults. DGM is also considered a risk factor for duodenal ulcer development. The prevalence of DGM in children and its association with gastritis, duodenitis, or the presence of Hp organisms is not clear. We investigated the prevalence of DGM in children and explore its association with several possible risk factors, including age, gender, gastritis, duodenitis, or Hp presence in the gastric antrum. METHODS: A retrospective analysis of 173 upper endoscopy procedures performed between 1993 and 1995 at Cabell Huntington Hospital, Huntington, WV, was done. Gastric and duodenal biopsies were stained with Giemsa for Hp detection, periodic acid-Schiff for DGM, and hematoxylin and eosin for histologic assessment. Gastric mucosal inflammation was graded according to Sydney criteria. RESULTS: Duodenal gastric metaplasia was identified in 23 of 173 (13%) patients. Duodenitis but not age, gender, gastritis, or the presence of Hp in the gastric antrum was associated with DGM development. In 4 of 23 DGM foci, Hp was identified. CONCLUSIONS: In children, DGM is not the consequence of Hp infection.     

Superoxide dismutase activity in Helicobacter pylori-positive antral gastritis in children

Reactive oxygen metabolites have been implicated in gastric mucosal injuries. Superoxide dismutase, a scavenger of superoxide radical, is a key enzyme in gastric mucosal protection against several damaging factors. This study was aimed at investigating the relationship of superoxide dismutase activity to Helicobacter pylori-induced antral gastritis in children. Two groups of 11 children each, one positive and the other negative for Helicobacter pylori, were studied. Biopsies from the antrum and corpus were obtained for evaluation of Helicobacter pylori by CLOtest and histology as well as for superoxide dismutase activity (cytochrome c method). Erythrocytic and serum superoxide dismutase levels were determined as well. Superoxide dismutase activity was significantly higher only in the antrum of children with Helicobacter pylori-induced antral gastritis. There was no significant difference in superoxide dismutase activity in the corpus, erythrocytes, or serum of both groups. These findings may suggest a pathogenic relationship between the presence of Helicobacter pylori and oxygen radicals in inducing antral mucosal injury.     

Gastric mucosal hepatocyte growth factor in Helicobacter pylori gastritis and peptic ulcer disease

OBJECTIVES: Hepatocyte growth factor (HGF) is increasingly recognized for its role in a variety of hepatic and systemic diseases. Its relationship to gastritis has not been studied. We aimed at measuring gastric mucosal HGF levels in the presence or absence of Helicobacter pylori gastritis, in peptic ulcers, and in response to H. pylori eradication. METHODS: Fifty one patients were studied. Patients were not entered if they had liver disease, malignancy, or any systemic illness. HGF was measured in gastric antral incubates using an enzyme-linked immunosorbent assay. Assessments were repeated 6 wk after a 2-wk course of anti-H. pylori triple therapy in 12 patients. Code numbers were used for blinding. RESULTS: The median gastric mucosal HGF level was 36 ng/gm/tissue in patients with H. pylori gastritis (n = 33) compared with 19 ng/gm in 18 negative controls (p = 0.0024), 18 ng/gm after the eradication of H. pylori (p = 0.021), 23 ng/gm in all patients with ulcers (n = 10), and 26 ng/gm/tissue in H. pylori-positive ulcers (n = 7). CONCLUSIONS: Gastric mucosal HGF levels were elevated in H. pylori gastritis and reduced by its eradication. These results are relevant to our understanding of the increased gastric cell proliferation in patients with H. pylori-related gastritis.     

Adaptation and radiographic evaluation of four adhesive systems

Specific pathogen-free Mongolian gerbils were infected orally with Helicobacter pylori to establish a new small animal model of severe gastritis H. pylori was recovered by culture from both antrum and body over a 16-week period after a single inoculation. The number of H. pylori colonising the antrum was about 100-fold higher than in the body, and this was consistent throughout the experiment. Histological examination showed that all animals developed severe inflammation with infiltration of polymorphonuclear leucocytes and mononuclear cells into the lamina propria and submucosa of the antrum from 4 weeks after infection. From 8 weeks after infection, multifocal lymphoid follicles appeared in the lamina propria and submucosa, and micro-erosions were also observed in the epithelial layer. At 16 weeks after infection, ulceration with disruption of the lamina muscularis mucosae was observed in the antral mucosa. To determine whether H. pylori caused gastritis or not, infected gerbils were treated with amoxycillin. After the treatment, gastritis could not be seen in the gastric mucosa. Therefore, the Mongolian gerbil is a useful small animal model to study the pathogenesis of H. pylori in gastric ulceration and severe gastritis and to assess anti-H. pylori treatment.     

Stimulated gastrinemia, parietal cell mass and stimulated acid secretion in autonomous chronic gastritis: Helicobacter pylori influence

BACKGROUND/AIMS: In the present experience, an evaluation has been carried out of stimulated gastrinemia, parietal cell mass, and acid secretion in the course of a paradigmatic condition, such as autonomous chronic gastritis, in order to reveal possible changes induced by the presence of Helicobacter Pylori (HP). MATERIALS AND METHODS: We evaluated 153 patients with chronic gastritis of the antrum and/or body fundus, in different combinations not associated with peptic pathology. RESULTS: In the group of subjects with antral superficial chronic gastritis associated with normal body-fundic mucosa or with body-fundic superficial chronic gastritis, about 40% of the subjects in the HP positive group show gastrinemia values which are higher than the norm. The evaluation of parietal cell and stimulated acid secretion yielded no differences between the HP positive and HP negative groups: it emerges that these parameters vary exclusively according to the histologic state of the body-fundic mucosa. In the patients group with hypergastrinemia, the study has revealed no variations in parietal cell mass and acid secretion. CONCLUSION: Evidently the increase in gastrinemia in these subjects was not important enough to induce an increase in parietal cell mass and acid secretion. It emerges how the presence of HP does not imply substantial changes on the gastric cyto-functional parameters: these variations depend mainly on the histologic state of the gastric mucosa.     

Dose uniformity of ferromagnetic seed implants in tissue with discrete vasculature: a numerical study on the impact of seed characteristics and implantation techniques

There is evidence of a two-way interaction between gastric acid secretion and H. pylori-associated gastritis. Gastric acid secretion influences the density of H. pylori colonisation, its distribution within the stomach and the severity of the mucosal inflammatory response to the infection. In addition, H. pylori gastritis alters gastric acid secretion. In subjects with a predominant antral gastritis, it increases acid secretion predisposing to duodenal ulcer, whereas in others with predominant body gastritis, acid secretion is impaired and the subjects have an increased risk of gastric cancer. The two-way interaction between acid secretion and H. pylori gastritis is observed when H. pylori-positive subjects are treated with proton pump inhibitor agents. The inhibition of acid secretion induces a body gastritis and this inflammation of the body mucosa inhibits acid secretion thus augmenting the anti-secretory effect of the drug. In this article, we discuss the interaction between gastric acid secretion and H. pylori gastritis and its importance in determining disease outcome.     

Synthetic implants in the reconstruction of the ossicular chain

OBJECTIVE: To determine whether there is a relationship between overexpression of c-met oncoprotein and stage of human gastric mucosal lesions, and its significance. METHOD: Immunohistochemical staining was used in 157 cases of endoscopic biopsies with c-met monoclonal antibody, S-19, which was raised against the human c-met gene product. RESULTS: overexpresion of c-met oncoprotein was detected in 3/30 cases (10%) of superficial gastritis, 4/33 cases (12.1%) of chronic atrophic gastritis, 10/31 cases (32.3%) of intestinal mataplasia, 10/30 cases (33.3%) of dysplasia, and 10/30 cases (33.3%) of gastric carcinoma. The positive staining rate was higher in intestinal mataplasia (54.8%), dysplasia (56.7%), carcinoma (53.3%) than in two kinds of simple chronic gastritis (P < 0.05). The positive staining was obviously located in luminal membrane of mucosal cells. The positive cells were mainly situated in proliferative cell zone of gastric glands. Moreover, the weak staining only in this zone was shown in two of the three normal mucosa. CONCLUSIONS: The overexpression of c-met may be involved in proliferation of gastric mucosa. It is possible that persistent overexpression of c-met oncoprotein is associated with the malignant transformation of gastric mucosal cells.     

Subcorneal pustular dermatosis in a patient with hyperthyroidism

OBJECTIVES: Gastric carcinoma is the world's second most common cancer. Recent studies suggest an association between Helicobacter pylori and gastric carcinoma. The aim of this study was to address the effects of H. pylori infection on gastric antrum mucosal cell proliferation. METHODS: Forty patients undergoing upper endoscopy for standard indications were included in the study. A rapid urease test was used to determine the presence of H. pylori. Epithelial cell proliferation was determined by immunohistochemical techniques utilizing monoclonal antibody to bromodeoxyuridine. RESULTS: There were no significant differences in the number of labeled cells and in the proliferation fraction (p > 0.1) when patients with H. pylori were compared with those without, and when those over the age of 50 were compared to those under 50. The presence of ulcers similarly had no effect (p > 0.1). CONCLUSION: Helicobacter pylori infection does not increase gastric antrum mucosal cell proliferation.     

Number, fixation properties, dye-binding and protease expression of duodenal mast cells: comparisons between healthy subjects and patients with gastritis or Crohn's disease

There is an accumulation of evidence to suggest that mast cells may play a key role in gastrointestinal inflammation. We have investigated the numbers and heterogeneity in staining properties of mast cells in biopsies of the duodenum of normal subjects (n = 10), and of normal duodenum from patients with Crohn's disease of the ileum and/or colon (n = 7) or with Helicobacter-associated gastritis of the antrum/corpus (n = 6). In normal donors, two subsets of mast cells, one located in the duodenal mucosa and the other in the submucosa, were clearly distinguished by their morphology and dye-binding properties. Whereas submucosal mast cells stained metachromatically with Toluidine Blue after neutral formalin fixation and emitted a yellow fluorescence after staining with Berberine sulphate, those in the mucosa were invisible using these stains. In patients with gastritis or Crohn's disease, there were marked changes in the numbers of mucosal mast cells compared with control subjects even though the duodenal biopsies were from apparently uninvolved tissue. Gastritis was associated with increased mucosal mast cell numbers (controls: 187 +/- 23 cells mm-2; gastritis: 413 +/- 139 cells mm-2; p = 0.0004), but mean mucosal mast cell counts in the uninvolved duodenum of Crohn's patients were actually decreased (34 +/- 30 cells mm-2, p = 0.0147). The clear differentiation between mucosal and submucosal mast cells on the basis of metachromasia with Toluidine Blue was not seen in biopsies from the patients with gastritis or Crohn's disease. Previous studies which have suggested that there are no distinct mucosal and submucosal mast cell subsets in the human intestine may, therefore, have been affected by the use of tissue from diseased subjects. Heterogeneity in the expression of mast cell tryptase and chymase was seen by immunohistochemistry using specific antibodies, but the relative numbers of mast cell subsets were critically dependent on the methods used. Using a sensitive staining procedure, the majority of mucosal mast cells stained positively for chymase as well as for tryptase, an observation confirmed by immunoelectron microscopy and immunoabsorption studies. Our findings suggest that early stages in intestinal inflammation may be reflected in changes in mast cell numbers and in their staining properties, and call for a reappraisal of mast cell heterogeneity in the human intestinal tract.     

Effect of duodenal contents on the gastric antrum. Experimental study on dogs

16 dogs were subjected to surgical techniques in order to maintain the gastric antrum in continuous and chronic contact with duodenal contents. Eight dogs were followed up for six months and the remainder for twelve months. There were no histological findings of atrophic gastritis or gastric ulcer.     

Effect of chronic duodenal ulceration and its treatment with lanzoprazole or sucralfate on gastroduodenal mucosal protein turnover and TGF-alpha, bFGF, and EGF receptor expression in humans

In order to investigate whether chronic duodenal ulcer disease is a consequence of disturbed mucosal turnover and growth factor expression, we studied 16 patients with duodenal ulcers before, during, and after endoscopic healing with lansoprazole or sucralfate. Before treatment, gastric fundal and antral mucosal protein turnover rates were higher in patients than controls, without parallel increases in growth factors. Both forms of therapy produced similar changes, with overall increases in duodenal mucosal turnover and transforming growth factor-alpha (TGF-alpha) and epidermal growth factor receptor (EGF-r) levels. Measurements after healing showed persistent elevations of mucosal turnover in the antrum and duodenum and depressions of basic fibroblast growth factor (bFGF) in gastric fundal and duodenal mucosa. We conclude that mucosal turnover is abnormally high in patients with chronic duodenal ulcer disease and is not easily explained by growth factor changes. The failure of lansoprazole and sucralfate to normalize rates, despite endoscopic healing, may explain the high ulcer relapse rates in non-HP-eradicated patients.     

Helicobacter pylori infections in children in the tropical zone. Endoscopic and histological aspects

AIMS: To assess the endoscopic and histological aspects of Helicobacter pylori (H. pylori) infection in children in a prospective study. PATIENTS AND METHODS: One hundred and four children (6 months-15 years old), with digestive symptoms admitted to the Pediatric Department of the National Hospital of Ouagadougou between February Ist and October 31 1996, underwent upper digestive endoscopy with fundic and antral biopsies for histological and bacteriological analysis. RESULTS: Endoscopy was normal in 80 cases (77%). No lesion was specific of H. pylori infection. Nodular gastritis was observed in 3% of the cases only. Duodenal ulcers were seen in 3 children (3%). 83% of the children had chronic antral gastritis, associates with H. pylori in 95% of the cases. The lesions were follicular gastritis (45%), mild atrophic gastritis (38.5%) and lymphocytic gastritis (1%). Follicular gastritis was more pronounced in the antrum than in the fundus. CONCLUSION: The high prevalence of early H. pylori infection and chronic gastritis in children contrasts with the rarity of gastric cancer in black Africa. Protective factors or peculiar strains should be searched for.     

Chronic gastric ulcer in the rat produced by wounding at the fundo-antral junction

Standardized 8-mm mucosal wounds were made in the rat stomach at the rumeno-fundic junction, fundus, fundo-antral junction, and antrum, and examined at intervals up to 8 months. All wounds at the rumeno-fundic junction and fundus were healed within 4 weeks and at the antrum within 12 weeks. The majority of wounds at the fundo-antral junction remained chronic and at 8 months 41 of 50 rats still had ulcers 2 mm or greater in diameter. These findings suggest that the fundo-antral junction is an area which is susceptible to the development of chronic ulcers. This is a simple and reliable method of producing chronic gastric ulcers and does not alter the continuity or disturb the function of the gastrointestinal tract.