Chronic gastritis--a pathogenetic approach

History of chronic gastritis: How our perceptions have changed

Currently, the diagnostic strategy for chronic gastritis (CG) is aimed not just at fixing the presence of gastric mucosal inflammation, but also at gastric cancer (GC) risk stratification in a particular patient. Modern classification approach with the definition of the stage of gastritis determines the need, activities and frequency of dynamic monitoring of a patient. However, this attitude to the patient suffering from CG was far from always. The present publication is a literature review describing the key milestones in the history of CG research, from the description of the first observations of inflammation of the gastric mucosa, assessment of gastritis as a predominantly functional disease, to the advent of endoscopy of the upper digestive tract and diagnostic gastric biopsy, assessment of the role of Helicobacter pylori infection in progression of inflammatory changes to atrophy, intestinal metaplasia, dysplasia and GC.

Beyond Helicobacter: dealing with other variants of gastritis-an algorithmic approach

In daily practice, the presence of inflammation in gastric biopsies prompts a mental algorithm, an early question being whether the lesion present is Helicobacter-associated. If Helicobacter organisms are not found, then there is a further algorithm, governed by the predominant type of inflammatory cells present, and the presence of other features such as intraepithelial lymphocytosis, a subepithelial collagen band, granulomas, coexisting chronic inflammation, focality, and superimposed reactive changes including erosions and ulcers. Each of these generates its own differential diagnosis. If no inflammation is present, then the two major changes specifically looked for are the changes associated with hypergastrinaemia, by far the most common cause of which is treatment with proton pump inhibitors, and reactive changes. These may be present with and without accompanying inflammation, and, when the epithelial changes dominate, the term gastropathy is preferred. In this article, we present an approach to non-Helicobacter inflammation and gastropathies.

A comprehensive review of agrimoniin

Plant tannins are a unique class of polyphenols with relatively high molecular weights. Within the ellagitannins group, agrimoniin--dimeric ellagitannin--is one of the most representative compounds found in many plant materials belonging to the Rosaceae family. Agrimoniin was first isolated in 1982 from roots of Agrimonia pilosa Ledeb. (Rosaceae), a plant traditionally used in Japan and China as an antidiarrheal, hemostatic, and antiparasitic agent. Agrimoniin is a constituent of medicinal plants, which are often applied orally in the form of infusions, decoctions, or tinctures. It is also present in commonly consumed food products, such as strawberries and raspberries. It is metabolized by human gut microbiota into a series of low-molecular-weight urolithins with proven anti-inflammatory and anticancer in vivo and in vitro bioactivities. The compound has received widespread interest owing to some interesting biological effects and therapeutic activities, which we elaborate in the present review. Additionally, we present an overview of the techniques used for the analysis, isolation, and separation of agrimoniin from the practical perspective.

Different Pathophysiology of Gastritis in East and West? A Western Perspective

Background

Gastritis results from multifactorial gastric mucosal injury. Helicobacter pylori (Hp) is the main cause, and associated diseases have typical underlying patterns of gastritis. Gastric ulcer and gastric cancer (GC) develop from chronic atrophic corpus gastritis (CAG) which therefore represents the most important pattern. GC incidences in East Asia are substantially higher than elsewhere, and this should be also reflected by higher prevalences of CAG and characteristic differences in pathophysiology compared to the West.

Summary

The few available comparative studies of gastritis in Eastern and Western patients are summarized. The main pathogenic factors of gastritis are discussed together with their limitations to explain local differences in disease outcome. Emphasis was put to also include less well-established pathogenic host and environmental factors of possible impact.

Conclusions

CAG is more prevalent in East Asian areas with high GC incidences than the West. Geographic heterogeneity of associated diseases is due to differences in Hp prevalence and virulence as well as modulating host and environmental factors. The following may contribute to the higher burden of CAG in the East: ABD type of CagA with vacA s1 and babA2 alleles of Hp, host Lewis(b) expression in sej/sej nonsecretors, H. heilmannii, low parietal cell mass, high sodium and nitrate intake, preferences in vegetable and fruit consumption, cigarette smoking, air pollution, alcohol. Conversely, green tea, nonfermented soy products and rice may confer protective effects. Hp is on the decline, but also in a world cleared from this bacterium, differences in host genetics will continue to modify gastric disease outcome together with maintained customs as part of cultural diversity.

Detoxification of 7-dehydrocholesterol fatal to Helicobacter pylori is a novel role of cholesterol glucosylation

The glucosylation of free cholesterol (FC) by Helicobacter pylori cells has various biological significances for the survival of this bacterium. H. pylori cells with glucosylated FC are capable of evading host immune systems, such as phagocytosis by macrophages and activation of antigen-specific T cells, and surviving in the gastric mucosal tissues for long periods. An additional role of cholesterol glucosylation in the survival of H. pylori which is distinct from the role of escaping the host immune system, however, has yet to be identified. This study demonstrated that 7-dehydrocholesterol (7dFC), an FC precursor, is a toxic compound fatal to H. pylori cells, but the cell membrane of H. pylori is capable of absorbing this toxic sterol via glucosylation. In contrast to the case with 7dFC, no toxicity to H. pylori cells was detected from the glucosylated 7dFC. In addition, cgt gene mutant H. pylori cells that cannot glucosylate cholesterols had higher susceptibility to the toxic action of 7dFC than wild-type H. pylori cells. These results indicate that the cgt gene product of H. pylori serves to detoxify the sterol fatal to this bacterium and to permit this toxic sterol as a cell membrane lipid component. In summary, this study defined a novel role of cholesterol glucosylation in H. pylori.

Phosphatidylethanolamine of Helicobacter pylori functions as a steroid-binding lipid in the assimilation of free cholesterol and 3β-hydroxl steroids into the bacterial cell membrane

One of the unique features of Helicobacter pylori is its ability to assimilate free-cholesterol (FC) into its membranes. Via FC assimilation, H. pylori strengthens the membrane lipid barrier and/or evades the host immune system. No previous studies, however, have investigated the FC uptake mechanisms of the H. pylori cell. Phosphatidylethanolamine (PE) is the most prevalent lipid component of bacteria, including H. pylori, but the function of PE remains unclear. We were therefore interested in H. pylori PE (HpPE) and investigated the interaction of its PE with cholesterols. The PE isolated from H. pylori underwent a unique molecular interaction with FC, cholesterol ester (CE), and 2,6-di-O-methyl-β-cyclodextrin (dMβCD), a sterol solubilizer. HpPE interacted not only with the FC molecule, but also with the FC-dMβCD inclusion complex. In contrast, Escherichia coli PE (EcPE), prepared as a reference PE, seemed to bind only FC, and only via a hydrophobic interaction, without binding dMβCD. HpPE was clearly more potent than EcPE in binding FC. Intriguingly, HpPE had a negligible affinity for CE, while EcPE had a high affinity for CE, comparable to its affinity for FC. Further, HpPE interacted with 3β-OH steroids, pregnenolone and dehydroepiandrosterone, in the absence of dMβCD. Gas chromatogram-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) analyses revealed that the fatty acid compositions of HpPE were quite distinct from those of EcPE, and the C(14:0) fatty acid in the HpPE molecule was found to be significant in binding FC selectively. These results indicate that PE is a key candidate of nonesterified steroid-binding lipids in H. pylori.

Steroid hormones as bactericidal agents to Helicobacter pylori

Helicobacter pylori is a unique bacterial species that assimilates various steroids as membrane lipid components. Our group has recently found, however, that certain steroids may impair the viability of H. pylori. In this study, we go on to reveal that estradiol, androstenedione, and progesterone (PS) all have the potential to inhibit the growth of H. pylori. Of these three steroid hormones, progesterone demonstrated the most effective anti-H. pylori action. 17α-hydroxyprogesterone caproate (17αPSCE), a synthetic progesterone derivative, had a much stronger anti-H. pylori action than progesterone, whereas 17α-hydroxyprogesterone, a natural progesterone derivative, completely failed to inhibit the growth of the organism. Progesterone and 17αPSCE were both found to kill H. pylori through their bacteriolytic action. Among five bacterial species investigated, H. pylori was the only species susceptible to the bactericidal action of progesterone and 17αPSCE. The other four species, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus epiderimidis, all resisted this action. Progesterone and free-cholesterol (FC) obstructed each other's effects against the H. pylori cell. Taken in sum, these results suggest that progesterone and FC may bind to the identical region on the H. pylori cell surface. We expect these findings to contribute to the development of a novel anti-H. pylori steroidal agent.

The Sydney System for classification of gastritis 20 years ago

The roots of research into gastritis go back into the early decades of the 20th century. Modern aspects of its classification and knowledge of its biological course and consequences were relatively well known even at the time that Helicobcter pylori was discovered by Robin Warren and Barry Marshall in 1982. This discovery, however, significantly changed the field, establishing that the commonest form of gastritis is simply an infectious disease, a finding that raised enormous interest in the subject amongst gastroenterologists, microbiologists, pathologists and basic researchers. However, many of these "new" players in the field often had a limited knowledge of the morphological aspects of gastric inflammations and chronic gastritis. As a consequence in the late 1980's a Working Party was set up to review the biology and natural course of chronic gastritis, to propose a new classification for gastritis, and to provide simple guidelines for reporting the pathology of gastritis in endoscopic biopsies in an attempt to bring uniformity to the subject and facilitate comparative studies in what was to be an era of high research activity. These guidelines, The Sydney System: A New Classification of Gastritis was presented to the World Congress of Gastroenterology in Sydney in 1990, and was later published as six papers in the Journal of Gastroenterology and Hepatology. Now, twenty years on, this review looks back on the birth of Sydney System and why it is still important and successful.

Chronic gastritis in former times and now

The roots of gastritis research stretch far back into the 19th century, and into early decades of the 20th century. Modern aspects in classification of gastritis and knowledge of the biologic course of chronic gastric inflammation, and of the links of chronic gastritis with many important gastric disorders were well known even at time of discovery of Helicobacter pylori in 1982. This discovery, however, significantly changed the field and raised the interest of gastroenterologists in gastritis. Chronic gastritis became a curable disease with known etiology and well-established links to main gastric diseases including gastric cancer. The personal view of the author into this history is presented. Some events and observations which were, in his opinion, noteworthy and important in the story of chronic gastritis have been emphasized.

The relationship of Helicobacter pylori positivity with age, sex, and ABO/Rhesus blood groups in patients with gastrointestinal complaints in Turkey

BACKGROUND

To determine the magnitude of Helicobacter pylori infection in patients with gastrointestinal complaints in Turkey.

METHODS

We studied 1680 patients with variable gastrointestinal complaints. The H. pylori infection status was determined using C-14 urea breath test (UBT). Overall, 1567 patients (548 male, 1019 female; age range 4-80 years, mean 29.37 +/- 17.30 years) were included in this study. The relationship between H. pylori positivity and age, sex, sociodemographic characteristic, blood groups, and gastrointestinal diagnosis was determined.

RESULTS

H. pylori positivity was found to be 68%. The difference in positivity rates between age groups 4-9 years and other groups was statistically significant (p = .001). H. pylori positivity was 67.7% in males and 68.2% in females (p = .865). H. pylori positivity was 72.1, 65.1, 70, and 68.4% in blood groups A, B, AB, and O (p = .703), and 68.9% and 76.3% in Rh (+) and Rh (-) blood subgroups, respectively (p = .292). There was no statistically significant difference between H. pylori positivity and gastrointestinal diagnosis (p = .980). There was significant association between increased number of household members and low socioeconomic status, and H. pylori positivity (p < .001). Living in rural and suburban area was significantly associated with H. pylori positivity compared with living in urban.

CONCLUSIONS

H. pylori infection positivity rate was 68% in symptomatic subjects in Turkey and the positivity rate was significantly lower at age 4-9 years than the other age groups. It was not related to gender, ABO, and Rh blood groups and gastrointestinal diagnosis. Low socioeconomic conditions and living in rural and suburban area were significantly associated with H. pylori positivity.

Conversion of flavodoxin from holoenzyme to apoprotein during growth phase changes in Helicobacter pylori

The catabolic pathway for flavodoxin has yet to be clarified for any bacterial species. In this study, we found that the flavin mononucleotide in the flavodoxin of Helicobacter pylori is degraded to riboflavin via the phosphomonoesterase activity of class C acid phosphatase. The result is a conversion of holoflavodoxin to apoflavodoxin.

Vitamin B12 deficiency and gastric histopathology in older patients

AIM

To compare upper gastric endoscopic and histopathologic findings in older adults in the presence and absence of B12 deficiency.

METHODS

A prospective analysis of upper gastric endoscopic and gastric histopathologic findings from 30 newly identified B12-deficient patients (11 males, 19 females) and 16 controls with normal B12 status (6 males, 10 females) was performed. For all subjects, the indication for upper endoscopy and gastric biopsy were unrelated to B12 status. A single pathologist, blinded to B12 status, processed and interpreted the biopsy samples. Endoscopic and histopathologic findings were correlated with age, gender, hematocrit (Hct), MCV and B12 status.

RESULTS

The B12-deficient group had significantly lower mean serum B12 levels compared to the controls (P<0.00005) while their mean Hct, MCV and serum albumin levels were similar. Iron deficiency (ferritin-based) was present in 21% of B12-deficient patients and intrinsic factor antibodies were present in 29% (5/17) of B12-deficient patients. The endoscopic findings revealed significantly different rates of gastritis and atrophy between the B12-deficient and control groups (P=0.017). B12-deficient patients had significantly less superficial gastritis (62% vs 94%) and significantly more atrophic gastritis (28% vs 0%) as compared to the controls (P=0.039). Intestinal metaplasia was similar in both groups. Helicobacter pylori infection rates were similar in the B12-deficient patients and controls (40% vs 31%).

CONCLUSION

Significantly different endoscopic findings and types of gastritis could often be observed in the presence and absence of B12 deficiency. Atrophy, based on endoscopy, and atrophic gastritis, based on histopathology, suggest the presence of B12 deficiency. Gastric histopathology is not influenced by the age, gender, Hct or MCV of the patients.

Geographic pathology of Helicobacter pylori gastritis

BACKGROUND AND AIM

Helicobacter pylori is etiologically associated with gastritis and gastric cancer. There are significant geographical differences between the clinical manifestation of H. pylori infections. The aim of this study was to compare gastric mucosal histology in relation to age among H. pylori-infected patients from different geographical areas using the same grading system. The prevalence of atrophy and intestinal metaplasia were also compared with the respective gastric cancer incidence in the different countries.

METHODS

A total of 1906 patients infected with H. pylori from seven countries were evaluated. Entry criteria included H. pylori positive cases with antral and corpus biopsies between the ages of 18 and 75 years. The minimum number of cases required from a country was 100. Hematoxylin-eosin stained biopsies from antrum and corpus were scored semiquantitatively using the parameters suggested by the Sydney Classification System. Statistical evaluation was performed using Kruskal-Wallis test and Spearman's rank correlation test.

RESULTS

The severity of gastric atrophy varied among the different groups with the highest scores being present in Japan. The lowest scores were found in four European countries and in Thailand. The scores for intestinal metaplasia were low in general except for Xi-an, Japan, and Shanghai. For all the countries, the presence of atrophy in the antrum correlated well (r = 0.891) with the incidence of gastric cancer.

CONCLUSION

Using a standardized grading system in a large study of H. pylori-related geographic pathology, we found major differences in the overall prevalence and severity of H. pylori gastritis in relation to age. These differences mirrored the respective incidences of gastric cancer in those geographical areas.

Biomarkers in various types of atrophic gastritis and their diagnostic usefulness

Atrophic gastritis has been shown to involve either the oxyntic gland area, resulting in hypergastrinemia and hypopepsinogenemia I, the antral gland area, causing hypogastrinemia without change in serum pepsinogen I (diffuse antral gastritis; DAG), or the entire gastric mucosa (multifocal atrophic gastritis; MAG), resulting in both hypogastrinemia and hypopepsinogenemia I; and rare atrophic gastritis limited to the oxyntic gland area, with antibodies against oxyntic cells and/or intrinsic factor (autoimmune metaplastic atrophic gastritis; AMAG). This study was performed on 126 patients with various forms of gastritis and on 126 age- and gender-matched controls, who were subjected to endoscopy with biopsy, H. pylori testing (13C-UBT, serology), assays for serum gastrin and pepsinogen I, and testing for basal and pentagastrin-induced gastric acid secretion. The following groups of patients were examined: group I (N = 22), with AMAG; group II (N = 53), with DAG; group III (N = 51), with MAG; and group IV (N = 126), age- and gender-matched controls without gastritis. The following changes were found. In group I very high serum gastrin and very low pepsinogen I were observed, and all patients were achlorhydric and H. pylori negative. In group II, with low serum gastrin and normal pepsinogenemia and gastric chlorhydria, all patients were H. pylori positive. In group III, with lower serum gastrin and lower pepsinogen I levels and reduced chlorhydria, all patients were also H. pylori positive. And all group IV controls, with normal serum gastrin and pepsinogen I and normal gastric acid secretion without antral or fundic gastritis, were H. pylori negative. We conclude that measurements of serum gastrin and pepsinogen I and gastric acid secretion as well as testing for H. pylori infection may be useful in noninvasive diagnosis of various types of atrophic gastritis and in identification of patients with premalignant gastritis and a high risk of gastric cancerogenesis.

Effects of duodenogastric reflux on gastrin cells, somatostatin cells and serotonin cells in human antral gastric mucosa

Duodenogastric reflux (DGR) has been found to give rise to a hypochlorhydria secondary to alkaline reflux. We investigated whether there is a link between DGR and the gastrin, somatostatin, and serotonin cell numbers and the granular content of gastrin, somatostatin, and serotonin in endocrine cells in human antral mucosa. We investigated 38 selected Helicobacter pylori-negative patients with visual primary excessive DGR in upper endoscopy and symptoms of epigastric pain and bile vomiting. Ten control patients were included in this study. None of the patients had peptic ulcer or had received any medication. Antrum (10 biopsies from five different zones: the lesser and major curvature, the anterior and posterior wall, and the pylorus) and corpus (two biopsies from major curvature about 10 cm below the cardia) biopsy specimens were collected for routine histology, as well as for light and electron immunohistochemistry. In patients without atrophy or intestinal metaplasia and in patients with mild atrophy or mild intestinal metaplasia, the number of gastrin and somatostatin cells was not different from that in controls. In moderate atrophy or moderate intestinal metaplasia, however, the number of gastrin and somatostatin cells decreased. Serotonin cell number was significantly higher in all patients with DGR as compared with controls. The mean somatostatin granular content was increased (3.6+/-0.2 vs. 3.2+/-0.1). In addition, lysosomes with engulfed somatostatin granules were found. The mean serotonin granular content was decreased (2.3+/-0.3 vs. 2.9+/-0.3), while the mean gastrin granular content remained unchanged (2.5+/-0.3 vs. 2.4+/-0.2). Ultrastructurally, the granules in serotonin-positive cells corresponded to the gastric variant or to the intestinal variant of serotonin cells. The endocrine cells were found to have few granules positive for serotonin. It is concluded that DGR inhibits somatostatin granular release, but stimulates both serotonin granular release and serotonin cell growth.

Immunological and morphogenic basis of gastric mucosa atrophy and metaplasia

Chronic gastritis with gastric mucosa atrophy, intestinal metaplasia and endocrine cell hyperplasia are alterations with an increased risk for the development of gastric neoplasias. Immunological studies in autoimmune gastritis, in atrophic Helicobacter pylori gastritis and in studies with transgenic mice point to a central role of the parietal cell in the development of gastric mucosa atrophy. Destruction of gastric epithelial cells alone might not be sufficient for the loss of complete gastric glands. Gastric atrophy, endocrine cell hyperplasia and intestinal and pancreatic metaplasia can be regarded as the result of altered morphogenesis within the gastric mucosa. Impaired expression of the gastric morphogenic factor Sonic Hedgehog by parietal cells and increased expression of the transcriptional activators of intestinal and pancreatic differentiation, namely CDX2 and PDX1, seem to be crucial for the development of gastric atrophy and for intestinal, endocrine and pancreatic transdifferentiation processes. Altered expression of these morphogenic factors is partly caused by changes in the gastric milieu. Further studies concerning the normal and pathological morphogenesis of the gastric mucosa and related tissues might give new insight into the pathogenesis of gastric atrophy and metaplasia.

Antibacterial activity of hydrolyzable tannins derived from medicinal plants against Helicobacter pylori

Helicobacter pylori is a major etiological agent in gastroduodenal disorders. In this study, we isolated 36 polyphenols and 4 terpenoids from medicinal plants, and investigated their antibacterial activity against H. pylori in vitro. All hydrolyzable tannins tested demonstrated promising antibacterial activity against H. pylori. Monomeric hydrolyzable tannins revealed especially strong activity. Other compounds demonstrated minimal antibacterial activity with a few exceptions. A monomeric hydrolyzable tannin, Tellimagrandin I demonstrated time- and dose-dependent bactericidal activity against H. pylori in vitro. On the other hand, hydrolyzable tannins did not affect the viability of MKN-28 cells derived from human gastric epithelium. Hydrolyzable tannins, therefore, have potential as new and safe therapeutic regimens against H. pylori infection. Furthermore, we investigated effects of hydrolyzable tannins on lipid bilayer membranes. All the hydrolyzable tannins tested demonstrated dose-dependent membrane-damaging activity. However, it remains to be elucidated whether their membrane-damaging activity directly contributes to their antibacterial action.

Essential role of magnesium ion in water for colonization of Helicobacter pylori in 2-week-old miniature pigs

This study was designed to determine whether magnesium ion in water would influence the colonization of Helicobacter pylori in 2-week-old miniature pigs. Groups A (2 pigs) and B (1 pig) were both fed a milk diet dissolved in drinking water, Group C (2 pigs) was fed a milk diet dissolved in deionized distilled water (DDW), and Group D (1 pig) was fed a milk diet dissolved in DDW supplemented with MgCl2. Groups B, C, and D were all challenged with H. pylori, and Group A was not. Necropsy was performed on the pigs on postinfection Day 5, and biopsy specimens were taken from 16 sites of the stomach. H. pylori were recovered from 11 of 16 sites in Group B, 1 of 32 sites in Group C, and 13 of 16 sites in Group D. On the other hand, the degree of lymphocyte infiltration increased in the order of Group A < Group B < Group C < Group D. These observations suggest that magnesium ion in drinking water is essential for the colonization of H. pylori in the pig stomach. Possible mechanisms for the lymphocyte infiltration are discussed.

Duodenogastric reflux and Helicobacter pylori infection synergistically increase gastric mucosal cell proliferative activity in Mongolian gerbils

BACKGROUND

Helicobacter pylori and duodenogastric reflux (DGR) are both recognized as aetiological factors in chronic gastritis and gastric carcinogenesis. In this study, a Mongolian gerbil (MG) model was used to investigate the histopathological changes in the gastric mucosa resulting from DGR and/or H. pylori infection.

METHODS

One-hundred-and-eleven 7-week-old, specific-pathogen-free, male MGs were divided into four groups: normal controls, gerbils with surgically induced DGR, and H. pylori-infected gerbils with and without DGR. Gerbils were killed 4, 12 and 26 weeks after DGR surgery, their stomachs removed and sections prepared. Sections were fixed immediately in 20% phosphate-buffered formalin and subjected to haematoxylin and eosin staining, Alcian blue at pH 2.5/periodic acid-Schiff staining, and immunostaining for smooth muscle cells, H. pylori and 5'-bromo-2'-deoxyuridine (BrdU).

RESULTS

The gastric mucosa of H. pylori-infected gerbils showed chronic active gastritis irrespective of DGR throughout the experimental period. The gastric mucosa of H. pylori-infected gerbils with DGR demonstrated higher BrdU labelling than in the other groups.

CONCLUSIONS

In MGs, DGR and H. pylori infection synergistically increased gastric mucosal cell proliferative activity. DGR and H. pylori infection may be involved synergistically in gastric carcinogenesis by increasing cell proliferative activity.

Effect of H. pylori infection on the expression of cyclooxygenase-2 in human gastric mucosa

Cyclooxygenase-1 is the primary isoform responsible for the production of cytoprotective prostaglandins (PGE(2) and PGI(2)) in the stomach. In contrast COX-2 is induced at the sites of inflammation. Using Helicobacter pylori infection as a model of inflammation, this study was designed to evaluate the effects of H. pylori infection on prostanoid synthesis and expression of COX-2 in human gastric mucosa. Prostaglandin (PGE(2)) and prostacyclin (PGI(2)) synthesis in gastric biopsies obtained from 21 patients undergoing diagnostic endoscopy, were determined. H. pylori was detected by CLO test, histology and culture. Biopsy samples were incubated either with NS-398, selective COX-2 inhibitor or aspirin. Samples were also treated with endotoxin (LPS) in order to induce COX-2 expression. Tissue was also analysed for COX-2 expression in vivo by immunohistochemistry. In 15 out of 21 patients, H. pylori was detected by at least two of the three methods. Higher levels of PGE(2) and PGI(2) were seen in patients infected with H. pylori (191+/-30 and 245+/-88ng/mg protein, respectively) compared with non-infected patients (77+/-17 and 120+/-36ng/mg protein, respectively). There was significant inhibition of PGE(2) and PGI(2) with aspirin in both H. pylori infected (28+/-6.6 and 53+/-43ng/mg, respectively) and in non-infected patients (16+/-7 and 12.5+/-3.5ng/mg protein, respectively). However, NS-398 and LPS did not alter prostaglandin function significantly. Immunohistochemistry in all patients irrespective of Hp status demonstrated expression of COX-2.Lower concentration of constitutive expression of COX-2 was detected in human gastric mucosa by immunohistochemistry, however, H. pylori infection failed to induce COX-2 protein. In addition, increased prostaglandin synthesis in Hp-infected patients appears to be COX-1 mediated rather than COX-2. Furthermore, failure of endotoxaemia-treated sample to produce more PGE(2) in the face of enhanced COX-2 expression in gastric mucosa further suggests that increased prostanoids in human gastric stomach are COX-1 mediated.

Endoscopic classification of chronic gastritis based on a pilot study by the research society for gastritis

BACKGROUND

 Various types of classification of gastritis have been proposed, but no plausible classification has been available until now. The Research Society for Gastritis performed a pilot study to establish an endoscopic classification, taking into consideration the following: (i) ease of use; (ii) permitting everyone the common image; and (iii) presence of histopathological evidence.

METHODS

 One hundred and fifty-five patients were enrolled and underwent gastroscopy. Eight basic endoscopic and histological types of gastritis (superficial, hemorrhagic, erosive, verrucous, atrophic, metaplastic, hyperplastic and special types) were defined. Gastritis was endoscopically diagnosed according to the definition of the endoscopic types of gastritis. Four or more biopsy specimens were obtained from the lesser and the greater curvatures of the antrum and the corpus of each patient, and the histological findings of gastritis and Helicobacter pylori infection were assessed. The histological diagnosis of gastritis was made according to the definition of histology types of gastritis. The endoscopic and the histological diagnoses were then compared in a blinded fashion.

RESULTS

 Endoscopic diagnosis was 62% as sensitive as histological diagnosis for erosive gastritis, 67% for verrucous gastritis and 84% for atrophic gastritis in the antrum. In superficial gastritis, sensitivity was approximately 25% in the corpus, but only 8% in the antrum. Metaplastic and hyperplastic gastritis were correctly diagnosed only in severe cases.

CONCLUSION

 Five basic types of gastritis (superficial, erosive, verrucous, atrophic and special types) should be employed for the new endoscopic gastritis classification. Metaplastic and hyperplastic gastritis are considered to be subtypes of atrophic gastritis and they should be excluded from the basic endoscopic classification. A new definition of gastritis in the antrum accompanied by redness still remains to be investigated.

Successful eradication of Helicobacter pylori prevents relapse of peptic ulcer disease

BACKGROUND

The NIH consensus conference in 1994 recommended that all patients with peptic ulcers should be tested and treated for Helicobacter pylori. Recent studies have shown that the eradication of H. pylori is associated with a significant reduction in the relapse rate of peptic ulcers, but there are few reports about long-term outcome.

AIMS

To evaluate the relapse rate of peptic ulcer in the long-term follow-up of patients after H. pylori eradication therapy.

PATIENTS AND METHODS

Patients infected with H. pylori (445; 88 duodenal ulcer, 357 gastric ulcer) were randomly divided into three groups. In group A, patients received 'conventional treatment' including acid decreasing therapy with a histamine H2-receptor antagonist or proton pump inhibitor (PPI). In group B, patients received 'dual therapy' including one antibiotic plus acid-decreasing therapy. In group C, patients received 'triple therapy' with PPI plus amoxicillin and clarithromycin. Eradication of H. pylori infection was assessed by histology of biopsy specimens from both the antrum and body corpus at 4 weeks, and 6 and 12 months after stopping therapy. Endoscopy was performed at intervals of 6 months for 5 years.

RESULTS

Intention-to-treat eradication rates for the duodenal ulcer patients were 0% for group A, 46% for group B and 80% for group C; eradication rates for the gastric ulcer patients were 0%, 33% and 83% respectively. No recurrence was noted in the duodenal ulcer patients and only 4% of gastric ulcers recurred after successful eradication during follow-up for 5 years. In contrast, in patients with persistent H. pylori infection all DU and 92% of gastric ulcers recurred.

CONCLUSION

Eradication of H. pylori infection changes the natural course of peptic ulcer.

Helicobacter pylori-induced gastritis in experimentally infected conventional piglets

A conventional nonmutant animal that could be experimentally infected with Helicobacter pylori isolates would be a useful animal model for human H. pylori-associated gastritis. Gnotobiotic and barrier-born pigs are susceptible to H. pylori infection, but attempts to infect conventional pigs with this bacterium have been unsuccessful. In the present study, a litter of eight 20-day-old crossbreed piglets were purchased from a commercial farm. Six of them were orally challenged two to five times at different ages, between 29 and 49 days, with doses of H. pylori inoculum containing approximately 10(9) bacterial cells. Two animals served as controls. The inoculation program began 2 days postweaning when the piglets were 29 days of age. Prior to every inoculation, the piglets were fasted and pretreated with cimetidine, and prior to the first and second inoculation each piglet also was pretreated with dexamethasone. The challenged piglets were euthanasized between 36 and 76 days of age. H. pylori colonized all six inoculated piglets. The pathology of the experimentally induced gastritis was examined macroscopically and by light and electron microscopy. H. pylori induced a severe lymphocytic gastritis in the conventional piglets and reproduced the large majority of the pathologic features of the human disease. Therefore, the conventional piglet represents a promising new model for study of the various pathogenic mechanisms involved in the development of lesions of the human H. pylori-associated gastritis.

Efficacy of triple therapy with rabeprazole for Helicobacter pylori infection and CYP2C19 genetic polymorphism

BACKGROUND

Rabeprazole is a new, potent, proton pump inhibitor. The metabolism of rabeprazole is less dependent on CYP2C19 genetic polymorphism.

METHODS

A total of 102 Helicobacter pylori-positive patients with gastric ulcer were randomly allocated to three groups: rabeprazole 10 mg (RAC10), rabeprazole 20 mg (RAC20) or rabeprazole 40 mg (RAC40) plus amoxicillin 750 mg and clarithromycin 200 mg twice daily for 7 days. CYP2C19 genotype was determined by the polymerase chain reaction-restriction fragment length polymorphism method.

RESULTS

All-patients-treated-based eradication rates in patients treated with RAC10, RAC20 and RAC40 were 83%, 77% and 90%, respectively, and per protocol-based eradication rates were 83%, 80% and 90%, respectively. The eradication rates in the three groups were not significantly different. There was also no significant difference between the all-patients-treated-based eradication rate in CYP2C19 extensive metabolizers and that in poor metabolizers (86% vs. 77%). Adverse events were 12% in extensive metabolizers and 23% in poor metabolizers, and the difference in these incidence rates was also not statistically significant.

CONCLUSIONS

Triple therapy with 10 mg of rabeprazole combined with amoxicillin/clarithromycin is effective for Japanese patients with H. pylori infection, and the H. pylori eradication rate is not affected by CYP2C19 genetic polymorphism.

Combined effect of rebamipide and ecabet sodium on Helicobacter pylori adhesion to gastric epithelial cells

Helicobacter pylori is a major etiological agent in gastroduodenal disorders. The adhesion of H. pylori to gastric epithelial cells is the initial step of H. pylori infection. Inhibition of H. pylori adhesion is thus a therapeutic target in the prevention of H. pylori infection. We have reported that rebamipide and ecabet sodium, mucoprotective antiulcer agents, independently inhibit H. pylori adhesion. However, the antiadhesion activity of each antiulcer agent was incomplete. Experiments were performed to evaluate the combined effect of rebamipide and ecabet sodium on H. pylori adhesion to gastric epithelial cells. MKN-28 and MKN-45 cells, derived from human gastric carcinomas, were used as target cells. Twelve clinical isolates of H. pylori were used in this study. We evaluated the effects of rebamipide and ecabet sodium, individually and in combination, on H. pylori adhesion to target cells quantitatively using our previously established enzyme-linked immunosorbent assay. Rebamipide and ecabet sodium each partially inhibited H. pylori adhesion. In contrast, adhesion was almost completely inhibited by pretreating target cells and H. pylori with the combination of rebamipide and ecabet sodium. Our studies suggest that the synergistic antiadhesion activity of rebamipide and ecabet sodium is greater than that of each antiulcer agent alone.

Duodenogastric reflux is associated with antral metaplastic gastritis

BACKGROUND

It has long been suspected that duodenogastric reflux plays a role in the pathogenesis of intestinal metaplasia (IM), although recent studies have demonstrated a close association between Helicobacter pylori infection and gastroduodenal diseases, including IM. The objective of this study was to investigate the relation among IM and duodenogastric reflux, H pylori infection, and smoking.

METHODS

Subjects with "marked" characteristics of IM, all with extensive prepyloric distribution at endoscopy that was confirmed histologically, were studied as an IM group (27 men, 26 women; mean age, 64 years). A control group was comprised by subjects without characteristics of IM (29 men, 28 women; mean age, 63 years). Fasting pH, total bile acid concentration, and ammonia concentration were measured in the gastric juice of all participants. Histologic examination endoscopic biopsy specimens were evaluated histologically. H pylori infection was determined by serum antibody and urease testing, and by histology. Serum gastrin and pepsinogen concentrations, and gastric emptying time were measured. Dietary, drinking, and smoking habits were recorded. Comparisons were made between groups and analyzed statistically.

RESULTS

The pH and total bile acid concentrations were significantly higher in the IM group than the control group (p < 0.01). No significant difference in H pylori infection was found between the IM and control group. Smoking was associated with IM (odds ratio [OR], 15.74; 95% CI, 3.96 to 62.50).

CONCLUSIONS

A high pH and total bile acid concentration and smoking were associated with "marked" IM, suggesting that these factors may play a role in the development of IM.

High-dose ecabet sodium improves the eradication rate of helicobacter pylori in dual therapy with lansoprazole and amoxicillin

AIM

The additive effect of ecabet sodium in combination with dual therapy on Helicobacter pylori eradication was evaluated.

METHODS

H. pylori-positive chronic gastritis patients were randomly assigned to one of the following three groups and medicated for 2 weeks. Group LA: dual therapy (lansoprazole 30 mg o.d. plus amoxicillin 750 mg b.d.). Group LA1E: dual therapy plus ecabet sodium (1 g b.d.). Group LA2E: dual therapy plus ecabet sodium (2 g b.d.). Patients were evaluated 4 weeks after the cessation of treatment by culture and 13C-urea breath test.

RESULTS

Seventy-one patients (mean age, 56.6 years; range, 26-79 years; 40 males, 31 females) were enrolled in this prospective, single-blind study, and 68 completed the protocol. The eradication rates per protocol patient were 43% in group LA, 62% in group LA1E, and 79% in group LA2E, and those on the intention-to-treat basis were 42% in group LA, 57% in group LA1E and 79% in group LA2E. The eradication rate in group LA2E was significantly higher than group LA (P=0.032 in per protocol, P=0.022 in intention-to-treat). Adverse effects were observed in 10 patients in this study. There were no severe adverse effects caused by ecabet sodium.

CONCLUSION

High-dose ecabet sodium increases eradication rates of H. pylori in dual therapy with lansoprazole and amoxicillin.

Role of antigastric autoantibodies in chronic Helicobacter pylori infection

In recent studies a significant association between H. pylori infection and antigastric autoimmunity has been reported. Antigastric autoantibodies can be found in more than 30% of infected patients. Two distinct binding patterns of these autoantibodies have been described, first at the luminal membrane of the foveolar epithelium, and second at the canaliculi membranes of the parietal cells in the body mucosa. The latter type of autoantibodies correlates with histologic and clinical parameters of gastric mucosa atrophy. The gastric H,K-ATPase, which is known to be the autoimmune target in classical autoimmune gastritis, also represents a major autoantigen in atrophic H. pylori gastritis. Molecular mimicry between H. pylori and the host does not seem to be responsible for the generation of this type of autoreactivity. The development of antigastric autoantibodies may be a relevant host factor which contributes to the final clinical outcome of chronic H. pylori gastritis.

[Varioliform gastritis: frequency and relationship with lymphocytic gastritis]

Varioliform gastritis is currently recognized as a special kind of chronic gastritis characterized by nodules, thickened fugal folds and erosions. These features appear to be unusual and different from those seen in chronic gastritis. The frequency of varioliform gastritis rarely exceeds 3% and the diagnosis can be easily made by endoscopic examination. Very little is known about the etiopathogeny, clinical significance and evolution of this disease. The role of Helicobacter pylori still remains unknown, although a close relationship between this gastritis and lymphocytic gastritis was suggested to exist over the last few years. The aim of the present study was to investigate the frequency of varioliform gastritis and its possible correlation with lymphocytic gastritis. To our knowledge, this is the first systematic study of varioliform gastritis in South America. We studied endoscopically 200 consecutive patients and found only one case of varioliform gastritis (0.5%). In a second part of the study, we examined histopathologically mucosa biopsies from 24 patients with varioliform gastritis and studied the presence of intraepithelial lymphocytes to verify the presence of lymphocytic gastritis. No case was found. We conclude that there was no correlation between varioliform gastritis and lymphocytic gastritis in our patients.

Analysis of Helicobacter pylori binding site on HEp-2 cells and three cell lines from human gastric carcinoma

Helicobacter pylori (H. pylori) is a pathogen responsible for chronic gastritis and peptic ulcer diseases. It colonises the gastric mucus layer and adheres to the gastric epithelial cell surface. As this adherence is the first step of infection, it is important to study the adherence mechanism. The aim of this study was to analyse the specific binding assay of H. pylori to HEp-2 cells and three gastric phenotype cell lines, AGS, MKN-45 and AZ-521. H. pylori NCTC 11637 grown on agar plates was harvested and used in experiments. H. pylori was inoculated to pre-cultured cell monolayers. Adhered bacteria were labelled with an anti-H. pylori antibody and an FITC-conjugated secondary antibody and quantified by using a fluorescent plate reader. Microbial adherence to HEp-2 cells increased with incubation time and incubated concentration of H. pylori. No further increase was obtained with four or more hours of incubation or with a concentration of 4 x 10(7) bacteria/well or more. Scatchard analysis revealed a linear plot and the Bmax value was 88.3. Similar adherence patterns were obtained when AGS, AZ-521 and MKN-45 cells were used for adherence assays, but they had a lower binding affinity than HEp-2 cells and AZ-521. MKN-45 cells had less receptors than HEp-2 and AGS cells. In conclusion, H. pylori adhered to the cell surface could be quantified by this assay method. H. pylori adhesion to cell surfaces has a single population of binding site and one type of binding site on HEp-2, AGS, AZ-521 and MKN-45 cells.

A conventional beagle dog model for acute and chronic infection with Helicobacter pylori

Helicobacter pylori has been widely recognized as an important human pathogen responsible for chronic gastritis, peptic ulcers, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma. Little is known about the natural history of this infection since patients are usually recognized as having the infection only after years or decades of chronic disease. Several animal models of H. pylori infection, including those with different species of rodents, nonhuman primates, and germ-free animals, have been developed. Here we describe a new animal model in which the clinical, pathological, microbiological, and immunological aspects of human acute and chronic infection are mimicked and which allows us to monitor these aspects of infection within the same individuals. Conventional Beagle dogs were infected orally with a mouse-adapted strain of H. pylori and monitored for up to 24 weeks. Acute infection caused vomiting and diarrhea. The acute phase was followed by polymorphonuclear cell infiltration, interleukin 8 induction, mononuclear cell recruitment, and the appearance of a specific antibody response against H. pylori. The chronic phase was characterized by gastritis, epithelial alterations, superficial erosions, and the appearance of the typical macroscopic follicles that in humans are considered possible precursors of MALT lymphoma. In conclusion, infection in this model mimics closely human infection and allows us to study those phases that cannot be studied in humans. This new model can be a unique tool for learning more about the disease and for developing strategies for treatment and prevention.

Observer agreement on the grading of gastric atrophy

AIMS

Assessment of lesser or doubtful degrees of gastric atrophy can be difficult, especially in the antrum, since well established criteria are lacking. At the Houston Working Party on Gastritis in 1994 a visual analogue scale was designed for the grading of histopathological parameters. This was done to promote uniformity in grading by acting as a reference. The purpose of the present study was to measure interobserver variation between pathologists familiar with the Houston visual analogue scale in a specifically selected set of biopsies from patients with lesser or doubtful degrees of atrophy.

METHODS AND RESULTS

Thirty cases with biopsies of the antrum and corpus from a long-term follow-up study on Helicobacter pylori gastritis comprised the current study material. The cases were selected from that study because there had been uncertainty or disagreement on the presence of gastric atrophy. The study set of haematoxylin and eosin (H & E) slides was circulated amongst gastrointestinal pathologists familiar with the visual analogue scale who were unaware of the source of the study set nor had any other clinical information. Interobserver variability was analysed using kappa statistics. The overall agreement for the grade of atrophy in antral biopsies was 0.461; the kappa value was 0.18 (95% confidence limits 0.12-0.24), which is considered poor agreement. The kappa value was nevertheless statistically significant (P < 0. 01). The overall agreement on the grade of atrophy in the corpus biopsies was apparently good (0.833), but the kappa which adjusts for chance agreement was only moderate (0.48; 95% confidence limits 0.42-0.55; P < 0.001).

CONCLUSION

The studied series comprised a self-selected sample in which there was doubt about the grade of atrophy and such a sample will produce lower kappa values than a random sample of gastric biopsies. The results nevertheless confirm that better guidelines and firm criteria are needed to properly diagnose and grade gastric atrophy. It is suggested that the use of two grades, low- and high-grade atrophy, akin to that in use for grading inflammatory bowel disorder (IBD)- associated dysplasia, could improve agreement. Furthermore optimal biopsy quality with full thickness mucosa and proper orientation appears important for grading gastric atrophy.

Performance characteristics of an enzyme-linked immunosorbent assay for determining salivary immunoglobulin G response to Helicobacter pylori

We evaluated the salivary immunoglobulin G (IgG) immune response to Helicobacter pylori in 70 subjects by enzyme-linked immunosorbent assay (ELISA). Subjects with a positive H. pylori culture showed significantly higher titers of antibodies than subjects with no detectable H. pylori: the overall sensitivity and specificity of the test were 84 and 90%, respectively. The detection of salivary anti-H. pylori IgG antibodies may be considered as an alternative to serum IgG detection for ease of sample collection or when blood samples are not available in screening of patients with dyspepsia.

The physiology and metabolism of the human gastric pathogen Helicobacter pylori

Helicobacter pylori is a spiral Gram-negative microaerophilic bacterium that causes one of the most common infections in humans; approximately 30-50% of individuals in Western Europe are infected and the figure is nearly 100% in the developing world. It is recognized as the major aetiological factor in chronic active type B gastritis, and gastric and duodenal ulceration and as a risk factor for gastric cancer. H. pylori normally inhabits the mucus-lined surface of the antrum of the human stomach where it induces a mild inflammation, but its presence is otherwise usually asymptomatic. A variety of virulence factors appear to play a role in pathogenesis. These include the vacuolating cytotoxin VacA, cytotoxin-associated proteins, urease and motility. All are under intense study in an attempt to understand how the bacterium colonizes and persists in the gastric mucosa, and how H. pylori infections lead to the disease state. Although an explosion of research on H. pylori has occurred within the past 15 years, most efforts have been directed at aspects of the bacterium and disease process which are of direct clinical relevance. Consequently, our knowledge of many aspects of the physiology and metabolism of H. pylori is relatively poor. This should change rapidly now that the complete genome sequence of a pathogenic strain has been determined. This review focuses attention on these more fundamental areas of Helicobacter biology. Analysis of the genome sequence and some detailed metabolic studies have revealed solute transport systems, an incomplete citric acid cycle and several incomplete biosynthetic pathways, which largely explain the complex nutritional requirements of H. pylori. The microaerophilic nature of the bacterium is of particular interest and may be due in part to the involvement of oxygen-sensitive enzymes in central metabolic pathways. However, the biochemical basis for the requirement for CO2 has not been completely explained and a major surprise is the apparent lack of anaplerotic carboxylation enzymes. Although genes for glycolytic enzymes are present, physiological studies indicate that the Entner-Doudoroff and pentose phosphate pathways are more active. The respiratory chain is remarkably simple, apparently with a single terminal oxidase and fumarate reductase as the only reductase for anaerobic respiration. NADPH appears to be the preferred electron donor in vivo, rather than NADH as in most other bacteria. H. pylori is not an acidophile, and must possess mechanisms to survive stomach acid. Many studies have been carried out on the role of the urease in acid tolerance but mechanisms to maintain the protonmotive force at low external pH values may also be important, although poorly understood at present. In terms of the regulation of gene expression, there are few regulatory and DNA binding proteins in H. pylori, especially the two-component 'sensor-regulator' systems, which indicates a minimal degree of environmentally responsive gene expression.

The effect of oxygen on the growth and cell morphology of Helicobacter pylori

The in vitro effect of progressive oxygen decrease on the growth and morphology of Helicobacter pylori was studied. H. pylori ATCC 43,504 was used for the experiments. The strain inoculated in Brucella broth plus fetal calf serum was incubated under a controlled atmosphere with oxygen concentration from 5 to 0%. CFU ml-1 and bacterial morphology were detected at the time of spreading and at 24 h, 72 h, 7 days and 14 days. A detailed ultrastructural investigation of the bacterial cells, grown in different experimental conditions, was performed by scanning electron microscopy. Oxygen deprivation produced a rapid reduction of CFU ml-1. In particular, a significant reduction of viable bacteria was recorded at 72 h of incubation in the presence of 1% oxygen and anaerobiosis, and 0 CFU ml-1 was found after 7 days of incubation at the above mentioned oxygen concentrations. The coccoid phenotype was already prevalent after 24 h of incubation with a progressive tendency to aggregate in clusters. These clusters were progressively larger, depending on the reduction of oxygen concentration, since the aggregation phenomenon can be the expression of a hypothesized mechanism of protection among bacterial cells.

Analysis of immunoglobulin A antibodies to Helicobacter pylori in serum and gastric juice in relation to mucosal inflammation

Helicobacter pylori is a major etiologic agent in gastroduodenal disorders. In this study, immunoglobulin A (IgA) antibodies to H. pylori antigens were evaluated in serum and gastric juice specimens obtained from patients with gastritis or peptic ulcers by utilizing antibody capture enzyme-linked immunosorbent assays (ACELISAs). Urease alpha subunit (UA), urease beta subunit (UB), the 66-kDa heat shock protein (HSP), and the 25-kDa protein (25K) were used as antigens for the ACELISAs. The antibody titers of the ACELISAs reflect the ratio of H. pylori-specific IgA to total IgA. The ratio is stable, although the antibody concentration fluctuates in gastric juice. By using ACELISAs it was possible to evaluate quantitatively not only serum IgA antibodies but also gastric juice secretory IgA (S-IgA) antibodies. In both serum IgA and gastric juice S-IgA ACELISAs, the titers of antibody to HSP and 25K were remarkably correlated with the histologic grade of gastritis, whereas those to UA and UB were not strongly correlated with histologic grade. Thus, it is useful for estimating the histologic grade of gastritis to quantify serum IgA and gastric juice S-IgA antibodies to HSP and 25K.

Effect of rebamipide, a novel antiulcer agent, on Helicobacter pylori adhesion to gastric epithelial cells

Helicobacter pylori is a major etiological agent in gastroduodenal disorders. The adhesion of H. pylori to human gastric epithelial cells is the initial step of H. pylori infection. Inhibition of H. pylori adhesion is thus a therapeutic target in the prevention of H. pylori infection. Experiments were performed to evaluate the effect of rebamipide, a novel antiulcer agent, on H. pylori adhesion to gastric epithelial cells. MKN-28 and MKN-45 cells, derived from human gastric carcinomas, were used as target cells. Ten H. pylori strains isolated from patients with chronic gastritis and gastric ulcer were used in the study. We evaluated the effect of rebamipide on H. pylori adhesion to MKN-28 and MKN-45 cells quantitatively using our previously established enzyme-linked immunosorbent assay. The adhesion of H. pylori to MKN-28 and MKN-45 cells was significantly inhibited by pretreatment of these cells with 100 microg of rebamipide per ml. However, the adhesion was not affected by the pretreatment of H. pylori with rebamipide. On the other hand, the viabilities of H. pylori, MKN-28 cells, and MKN-45 cells were not affected by rebamipide. Our studies suggest that rebamipide inhibits the adhesion of H. pylori to gastric epithelial cells.

Crohn's disease of the upper gastrointestinal tract: the value of endoscopic examination

The involvement of the upper gastrointestinal (GI) tract has been considered to be a rare manifestation of Crohn's disease (CD). Retrospective studies have reported prevalence figures of 0.5-13%. The diagnosis of CD of the upper GI tract is based on clinical, radiological, endoscopic and histologic features. In contrast to the retrospective studies, prospective studies, in which patients with CD underwent routine endoscopic evaluation with biopsies, revealed a much higher frequency of endoscopic and histologic abnormalities. Since Helicobacter pylori is the most frequent cause of gastritis and the most important etiologic factor in peptic ulcer disease, it is important to assess the contribution of H. pylori in the interpretation of the abnormalities observed in the upper GI tract in patients with CD. Therapy for CD of the upper GI tract consists of drug therapy and endoscopic or surgical interventions and is in fact similar to that for distal CD. Corticosteroids are still the most important drugs in the treatment of CD of the upper GI tract. Sometimes adjunctive therapy, e.g. gastric antisecretory drugs and mucosa protective agents, is beneficial. Endoscopic evaluation of the upper GI tract with biopsies should be part of the work-up of CD patients.

Inhibitory action of YJA20379, a new proton pump inhibitor on Helicobacter pylori growth and urease

The activities of two types of antiulcer agents against 9 strains of Helicobacter pylori (H. pylori) were determined by the agar dilution method. The antiulcer agents were YJA20379, a newly synthesized proton pump inhibitor developed by Yung-Jin Pharmaceutical company, and omeprazole. Both compounds were found to have significant activities against this organism. The MIC values of YJA20379 and omeprazole were 11.7 and 31.25 micrograms/ml, respectively. In addition, the inhibitory potency of both compounds was investigated on H. pylori urease which is believed to be an important colonization and virulence factor in the pathogenesis of gastritis and peptic ulcers. These compounds dose-dependently inhibited urease extracted with distilled water and their IC50 values were 16.4 x 10(-5) M and 14.3 x 10(-5) M, respectively. In addition, a pH-dependent study to determine whether inhibitory potency would be activated by acid condition was performed. It was found that unlike omeprazole, YJA20379 was not affected by acid condition. To determine the inhibition pattern and optimal concentration of substrate, kinetics were evaluated at various pH levels (pH 5.0, 7.0, and 8.5). The data show that YJA20379 noncompetitively inhibited H. pylori urease and KM/Ki values were 0.96 mM/60 microM (pH 5.0), 0.56 mM/141.5 microM (pH 7.0), and 1.94 mM/34 microM (pH 8.5), respectively. Based on data obtained, it is concluded that YJA20379 is a significant inhibitor of H. pylori growth and urease and therefore, taking these results into consideration, YJA20379 might be a beneficial therapy for gastritis and peptic ulcers induced by H. pylori.

Effect of ecabet sodium on Helicobacter pylori adhesion to gastric epithelial cells

Helicobacter pylori is a major etiological agent in gastroduodenal disorders, with the adhesion of H. pylori to gastric epithelial cells being the initial step of H. pylori infection. Inhibition of H. pylori adhesion is thus a therapeutic target in preventing H. pylori infection. We evaluated the effect of ecabet sodium, an antiulcer agent, on H. pylori adhesion to gastric epithelial cells, using our previously established enzyme-linked immunosorbent assay. The adhesion of H. pylori was significantly inhibited by ecabet sodium in a dose-dependent manner. Our studies suggest that ecabet sodium inhibits the adhesion of H. pylori to gastric epithelial cells.

Low seroprevalence of Helicobacter pylori antibodies in historical sera of patients with Crohn's disease

BACKGROUND

Our aim was to determine the seroprevalence of Helicobacter pylori antibodies in historical sera from a large group of patients with Crohn's disease and to compare the findings with those of a control group of healthy blood transfusion donors.

METHODS

The historical sera from 386 patients with Crohn's disease were studied (serum age, 9.9 years; range, 0.4-21.6 years). Serum IgG and IgA H. pylori antibodies were measured with enzyme-linked immunosorbent assay. Western blots (detecting IgG only) were also used to study a subpopulation of the patients' sera and to assess the presence of cagA bands, indicating a cytotoxic variety of H. pylori. The serology of the Crohn's disease patients was compared with that of 277 age-matched controls. A longitudinal follow-up study of 14 IgG and IgA anti-H. pylori-positive and 14 IgG- and IgA-negative Crohn's disease patients was also performed (mean follow-up, 7.6 years; range, 1.7-20.5 years).

RESULTS

Of the total Crohn's disease patients, 47 (12.2%) had IgG antibodies against H. pylori, 67 (17.4%) had IgA antibodies, and 31 (8.0%) had both IgG and IgA antibodies. The corresponding antibody positivities for the controls were 98 (35.4%) for IgG, 77 (27.8%) for IgA, and 64 (23.1%) for both IgG and IgA. When compared, with the control group, the seroprevalence of H. pylori in the Crohn's disease patients was significantly lower (P < or = 0.002). In addition the relative IgG response of the patients was lower than the IgA response. The opposite was true for the controls. There was no difference in the absolute levels of H. pylori antibodies between patients and controls. In the follow-up study two patients initially IgG-positive for H. pylori became negative over time; these patients had been treated for their infection. the rest, who continued to be positive, were not treated. One patient who was initially IgA-positive also became IgA-negative over time. The follow-up group, who were initially IgG- and IgA-negative, remained IgG-negative with time, and two patients became IgA-positive. Findings of anti-H. pylori IgG were confirmed with Western blots. Furthermore, these showed that of the H. pylori-positive patients (indicated by their IgG positivity), 66% were infected with a cytotoxic (cagA-positive) variety, compared to 69.4% of the controls.

CONCLUSIONS

Patients with Crohn's disease have a lower prevalence of H. pylori antibodies than an age-matched control group. There is a reversal of the relative IgG and IgA responses in Crohn's disease patients compared with the controls. Of the Crohn's disease patients with H. pylori most are infected with cytotoxic varieties, similar to controls.

Reduced secretion of epidermal growth factor in duodenal ulcer patients with Helicobacter pylori infection

AIM: To investigate the concentration changes of epidermal growth factor (EGF) in duodenal ulcer patients with Helicobacter pylori (H. pylori) infection.

METHODS: Immunoreactive concentration of somatostatin, gastrin and epidermal growth factor of gastric and saliva juice in healthy volunteers, and chronic gastritis and duodenal ulcer patients with H. pylori infection were measured by radioimmunoassay.

RESULTS: Gastrin concentration of gastric juice in H. pylori-positive chronic gastritis (P > 0.05) and duodenal ulcer patients (P < 0.01) was higher than that of healthy volunteers (P < 0.05), whereas som atostatin concentration of gastric juice in chronic gastritis (P < 0.05) and duodenal ulcer patients (P < 0.01) was lower than that in healthy volunteers. Furthermore, EGF levels of gastric and saliva juice in duodenal ulcer patients with H. pylori infection (n = 10, 272.0 ng/L ± 96.3 ng/L and 8.3 ng/L ± 2.4 ng/L, respectively) were significantly lower than that in healthy volunteers (n = 12, 405.6 ng/L ± 35.6 ng/mL and 22.0 ng/L ± 17.0 ng/L, respectively) and in H. pylori-positive chronic gastritis patients (n = 25, 423.0 ng/L ± 104.0 ng/L and 22.0 ng/L ± 11.1 ng/L, respectively (P < 0.05).

CONCLUSION: A lower secretion of EGF may be a causative factor in the pathogenesis of H. pylori-positive duodenal ulcer.