BACKGROUND/AIMS: This study was designed to investigate the role of gastric acid in the extent of H. pylori-induced gastritis. METHODS: Twenty eight mice were innoculated with live H. pylori. They were allocated into four groups. Mice in group I received no treatment, group II mice were treated with sham injection, group III received 125microgram/kg body weight of pentagastrin, while group IV received 250microgram/kg body weight of pentagastrin subcutaneously three times a week. After 7 months, the mucosal pH, H. pylori density, neutrophils and monocytes infiltration, and the degree of atrophy were assessed in the stomach. RESULTS: In the gastric body, the densities of H. pylori were not different among groups. The degree of neutrophil infiltration was significantly lower in group IV compared to other groups (p<0.05). The degree of monocyte infiltration was also significantly lower in group IV than group III (p<0.05). In the gastric antrum, there was no significant difference of the H. pylori density, neutrophil and monocyte infiltration, and degree of atrophy among the groups. The mice with the gastric mucosal pH lower than mean of 3.2 had significant lower level of H. pylori density (1.4 vs. 2.4, p=0.04), and infiltration of neutrophils (0.9 vs. 2.3, p=0.018), and monocytes (1.2 vs. 1.8; p=0.011) than the those with mucosal pH above 3.2 in the body of stomach. CONCLUSIONS: Gastric acid plays a role in suppressing the proximal propagation of H. pylori-induced gastritis to the body of stomach.
Animals ; Female ; Gastric Acid/*metabolism ; Gastric Mucosa/pathology ; Gastritis/immunology/*microbiology ; Helicobacter Infections/*immunology/microbiology ; *Helicobacter pylori/isolation & purification ; Hydrogen-Ion Concentration ; Mice ; Mice, Inbred C57BL ; Models, Animal

BACKGROUND/AIMS: The cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), the proteins that have the role in the gastric carcinogenesis, are stimulated by H. pylori infection in the gastric mucosa. The aim of this study was to evaluate the expression of COX-2 and iNOS proteins one year after the eradication of H. pylori. METHODS: Gastric antral mucosa from fifty eight patients with chronic gastritis who were all infected with H. pylori was examined for the expression of COX-2 and iNOS proteins before and one year after the eradication of H. pylori by immunohistochemical stain. RESULTS: COX-2 and iNOS proteins were expressed in the epithelial cells and interstitial inflammatory cells of gastric mucosa. Percent expressions of COX-2 and iNOS were significantly decreased one year after the eradication in the patients with cured infection, but not in those having persistent H. pylori. COX-2 and iNOS expressions were well correlated with H. pylori density, acute and chronic inflammation of gastric mucosa. CONCLUSIONS: The eradication of H. pylori can decrease the expression of COX-2 and iNOS in the gastric mucosa in long-term period. This seems to be due to the removal of H. pylori itself and related regression of gastric inflammation.
Cyclooxygenase 2/immunology/*metabolism ; Drug Therapy, Combination ; Gastric Mucosa/*enzymology ; Helicobacter Infections/drug therapy ; *Helicobacter pylori ; Humans ; Nitric Oxide Synthase Type II/immunology/*metabolism ; Time Factors

BACKGROUND: Helicobacter pylori-induced destruction of the gastroduodenal mucosal barrier is initiated with mucosal infiltration of inflammatory cells. Cytokines and chemokines have been suggested to play important roles in the migration and activation of these inflammatory cells into the mucosa. The present study aimed to investigate expression rates of cyto-chemokine mRNAs using gastric mucosal biopsy specimens. METHODS: In 98 patients infected with Helicobacter pylori, mucosal mRNA expression rates of cytokines (IL-1beta, IL-6, and IL-10), C-C chemokines (macrophage inflammatory protein 1alpha [MIP-1alpha], and macrophage inflammatory protein 1beta [MIP-1beta], monocyte chemotactic and activating factor [MCAF], regulated on activation, normal T cell expressed and presumably secreted [RANTES]) and C-X-C chemokines (IL-8 and growth regulated alpha [GRO-alpha]) were examined using reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The expression rates of mRNA for IL-8, GRO-alpha, MIP-1alpha and RANTES were significantly more increased in H. pylori-positive patients than in H. pylori- negative patients. However, the expressions of IL-1beta, IL-6 and IL-10 mRNA were statistically not different between two groups. After eradication of H. pylori, expressions of mRNA for three cytokines (IL-1beta, IL-6 and IL-10), four C-C chemokines (MIP-1alpha, MIP-1beta, MCAF and RANTES) and two C-X-C chemokines (IL-8 and GRO-alpha) were significantly decreased. CONCLUSION: These results suggest that C-X-C chemokines and some C-C chemokines play important roles in H. pylori-associated peptic ulcer diseases.
Adult ; Aged ; Aged, 80 and over ; Chemokines, CC/metabolism ; Chemokines, CXC/metabolism ; Chi-Square Distribution ; Cytokines/*metabolism ; Female ; Gastric Mucosa/*immunology/metabolism ; Helicobacter Infections/*immunology/metabolism ; *Helicobacter pylori ; Human ; Male ; Middle Age ; Prospective Studies ; RNA, Messenger/metabolism

CD99 is characteristically expressed in Ewing's sarcoma/primitive neuroectodermal tumor. Recently its immunoreactivity has also been reported in other tumors. However, the significance of CD99 isoforms expressed in these tumors has not been elucidated. In this study, we evaluated the expression of CD99 isoforms and its relationship with histopathologic parameters in gastric adenocarcinomas. Paraffin sections of 46 gastric adenocarcinomas were stained with an anti-CD99 monoclonal antibody, YG32. Twelve (26.1%) cases of 46 gastric adenocarcinomas showed immunoreactivity to YG32. The CD99 expression was also seen both in non-neoplastic foveolar epithelial cells and infiltrating lymphocytes. In addition, Western blot and RT-PCR analyses revealed that the type I is the predominant isoform of CD99 in non-neoplastic and neoplastic gastric tissues. The CD99 expression was usually seen in the intestinal type adenocarcinoma, while rarely in the diffuse type. The CD99 immunoreactivity decreased in MMP-2-overexpressing adenocarcinomas (p=0.028). Our results suggest that the type I is the major isoform of CD99 expressed in non-neoplastic gastric mucosa and gastric adenocarcinomas and its downregulation in gastric adenocarcinoma may be associated with cellular dedifferentiation and/or MMP-2 overexpression.
Adenocarcinoma/*immunology/pathology ; Adult ; Aged ; Antigens, CD/*analysis/genetics ; Cell Adhesion Molecules/*analysis/genetics ; Female ; Gastric Mucosa/cytology/immunology ; Humans ; Male ; Matrix Metalloproteinases/metabolism ; Middle Aged ; Protein Isoforms/analysis/genetics ; RNA, Messenger/genetics/metabolism ; Stomach Neoplasms/*immunology/pathology

OBJECTIVETo study the changes of gastric mucosal CD4(+) and CD8(+) T cells in Helicobacter pylori (Hp) infected children.

METHODSSeventy nine patients with digestive tract symptoms were assessed by endoscopy, rapid urease test and histology. Forty four patients had Hp positive chronic superficial gastritis (Hp(+)CSG) and 35 patients had Hp negative chronic superficial gastritis (Hp(-)CSG). Gastric biopsy specimens were obtained from each patient. Peripheral blood samples were obtained from 33 patients (12 with Hp(+)CSG, 21 with Hp(-)CSG). Hp infection was identified by rapid urease test and histology. Hp infection was confirmed when a patient was positive for both of these tests. Four pieces of gastric antrum mucosal specimens were placed in Hank's balanced salt solution containing 1 mmol/L dithiothreitol (DTT) and 1 mmol/L ethylenediamine tetraacetic acid (EDTA). The specimens were treated with collagenase type I (120 U/ml) for three hours at 37 degrees C with agitation. The mononuclear cells were collected by removing undigested material and washed three times with RPMI 1640. Isolated gastic mononuclear cells were stained with CD3-FITC (fluorescein isothiocyanate), CD4-PE (R-phycoerthrin), CD8-PerCP (Peridinin-chlorophyll-alpha-protein) and measured by flow cytometry. Mucosal T lymphocytes were gated for the expression of CD3. Peripheral blood lymphocyte subsets were analysed by direct immunofluorescence.

RESULTSThe percentage of isolated gastric mononuclear cells within the CD3 gate were 3.26 +/- 1.98 in Hp(-)CSG, 4.37 +/- 1.97 in Hp(+)CSG. Relative CD4(+)(%), CD8(+)(%) and CD4(+)/CD8(+) of the CD3(+) cells respectively were 23.74 +/- 10.37, 47.04 +/- 12.00, 0.52 +/- 0.23 in Hp(-)CSG group, 40.28 +/- 11.35, 27.91 +/- 8.84, 1.55 +/- 0.52 in Hp(+)CSG group. CD4(+)(%), CD4(+)/CD8(+) in Hp(+)CSG group were significantly higher than those of Hp(-)CSG group and CD8(+)(%) was lower than those of Hp(-)CSG group (P < 0.01). There were no significant differences in peripheral blood T lymphocyte subsets between the two groups.

CONCLUSIONThe difference of gastric T lymphocyte response between Hp(+)CSG and Hp(-)CSG in children indicated that the local cellular immune reaction may play a critical role in the pathogenesis of Hp infection.

Biopsy ; CD4-Positive T-Lymphocytes ; immunology ; CD8-Positive T-Lymphocytes ; immunology ; Child ; Female ; Fluorescent Antibody Technique, Direct ; Gastric Mucosa ; metabolism ; pathology ; Gastritis ; immunology ; microbiology ; pathology ; Gastroscopy ; Helicobacter Infections ; immunology ; microbiology ; pathology ; Helicobacter pylori ; immunology ; metabolism ; pathogenicity ; Humans ; Male ; Pyloric Antrum ; metabolism ; pathology ; Urease ; biosynthesis ; metabolism

Helicobacter pylori (H. pylori) induces the activation of nuclear factor-kB (NF-kappaB) and cytokine expression in gastric epithelial cells. The Janus kinase/signal transducers and activators of transcription (Jak/Stat) cascade is the inflammatory signaling in various cells. The purpose of the present study is to determine whether H. pylori-induced activation of NF-kappaB and the expression of interleukin-8 (IL-8) are mediated by the activation of Jak1/Stat3 in gastric epithelial (AGS) cells. Thus, gastric epithelial AGS cells were infected with H. pylori in Korean isolates (HP99) at bacterium/cell ratio of 300:1, and the level of IL-8 in the medium was determined by enzyme-linked immonosorbent assay. Phospho-specific and total forms of Jak1/Stat3 and IkappaBalpha were assessed by Western blot analysis, and NF-kappaB activation was determined by electrophoretic mobility shift assay. The results showed that H. pylori induced the activation of Jak1/Stat3 and IL-8 production, which was inhibited by a Jak/Stat3 specific inhibitor AG490 in AGS cells in a dose-dependent manner. H. pylori-induced activation of NF-kappaB, determined by phosphorylation of IkappaBalpha and NF-kappaB-DNA binding activity, were inhibited by AG490. In conclusion, Jak1/Stat3 activation may mediate the activation of NF-kappaB and the expression of IL-8 in H. pylori-infected AGS cells. Inhibition of Jak1/Stat3 may be beneficial for the treatment of H. pylori-induced gastric inflammation, since the activation of NF-kappaB is inhibited and inflammatory cytokine expression is suppressed.
Blotting, Western ; DNA, Bacterial/analysis/genetics ; Epithelial Cells/metabolism ; Gastric Mucosa/drug effects/*immunology/microbiology ; Gene Expression Regulation/drug effects/*immunology ; Gene Expression Regulation, Bacterial ; Helicobacter Infections/immunology/*metabolism ; Helicobacter pylori/genetics/pathogenicity/*physiology ; Humans ; Interleukin-8/genetics/*metabolism ; Janus Kinase 1 ; NF-kappa B/biosynthesis/*metabolism ; Phosphorylation ; RNA, Messenger/metabolism ; STAT3 Transcription Factor ; Signal Transduction/genetics

Helicobacter pylori (H. pylori) induces the activation of nuclear factor-kB (NF-kappaB) and cytokine expression in gastric epithelial cells. The Janus kinase/signal transducers and activators of transcription (Jak/Stat) cascade is the inflammatory signaling in various cells. The purpose of the present study is to determine whether H. pylori-induced activation of NF-kappaB and the expression of interleukin-8 (IL-8) are mediated by the activation of Jak1/Stat3 in gastric epithelial (AGS) cells. Thus, gastric epithelial AGS cells were infected with H. pylori in Korean isolates (HP99) at bacterium/cell ratio of 300:1, and the level of IL-8 in the medium was determined by enzyme-linked immonosorbent assay. Phospho-specific and total forms of Jak1/Stat3 and IkappaBalpha were assessed by Western blot analysis, and NF-kappaB activation was determined by electrophoretic mobility shift assay. The results showed that H. pylori induced the activation of Jak1/Stat3 and IL-8 production, which was inhibited by a Jak/Stat3 specific inhibitor AG490 in AGS cells in a dose-dependent manner. H. pylori-induced activation of NF-kappaB, determined by phosphorylation of IkappaBalpha and NF-kappaB-DNA binding activity, were inhibited by AG490. In conclusion, Jak1/Stat3 activation may mediate the activation of NF-kappaB and the expression of IL-8 in H. pylori-infected AGS cells. Inhibition of Jak1/Stat3 may be beneficial for the treatment of H. pylori-induced gastric inflammation, since the activation of NF-kappaB is inhibited and inflammatory cytokine expression is suppressed.
Blotting, Western ; DNA, Bacterial/analysis/genetics ; Epithelial Cells/metabolism ; Gastric Mucosa/drug effects/*immunology/microbiology ; Gene Expression Regulation/drug effects/*immunology ; Gene Expression Regulation, Bacterial ; Helicobacter Infections/immunology/*metabolism ; Helicobacter pylori/genetics/pathogenicity/*physiology ; Humans ; Interleukin-8/genetics/*metabolism ; Janus Kinase 1 ; NF-kappa B/biosynthesis/*metabolism ; Phosphorylation ; RNA, Messenger/metabolism ; STAT3 Transcription Factor ; Signal Transduction/genetics

OBJECTIVETo determine the influence of Helicobacter pylori (H. pylori) on gastric cancer-related antigen MG7 expression.

METHODSThe H. pylori infection and the expression level of antigen MG7 in gastric mucosa were determined by HE stain, PCR, ELISA and immunohistochemistry in 291 patients with H. pylori-related conditions, among whom 34 were followed-up.

RESULTSNo significant difference was found between H. pylori-negative and H. pylori-positive intestinal metaplasia, atrophic gastritis and dysplasia of gastric epithelium in positive rate of antigen MG7 expression. There was significant difference between H. pylori-negative and H. pylori-positive superficial gastritis in the positive rate of MG7 expression (P < 0.05). During follow-up, one of 3 H. pylori-negative cases turned to be H. pylori-positive, and its MG7 expression turned to be higher at the same time. Three of 31 H. pylori-positive patients were discovered as having early gastric cancer, among whom one with antigen MG7 expression (+ + +) was found to have a reduced Mg7 expression accompanied with H. pylori eliminutied after operation.

CONCLUSIONThere is correlationship between H. pylori infection and MG7 expression in superficial gastritis. Although the MG7-positive lesions with H. pylori infection shows a benign nature in morphology, they also have the potential risk of developing into gastric cancer. Therefore, they should be followed up, during which special attention should be paid to patients with increased MG7 expression.

Antibodies, Bacterial ; blood ; Antigens, Neoplasm ; biosynthesis ; DNA, Bacterial ; genetics ; Enzyme-Linked Immunosorbent Assay ; Gastric Mucosa ; metabolism ; microbiology ; pathology ; Gastritis ; metabolism ; microbiology ; Helicobacter Infections ; metabolism ; microbiology ; Helicobacter pylori ; genetics ; growth & development ; immunology ; Humans ; Immunohistochemistry ; Polymerase Chain Reaction ; Stomach Diseases ; metabolism ; microbiology ; Stomach Ulcer ; metabolism ; microbiology

OBJECTIVETo investigate whether Helicobacter pylori infection has any effects on the epithelial cell proliferation, apoptosis and P53 gene expression as well as its role in the pathogenesis of chronic gastritis.

METHODSSixty children with chronic gastritis were studied. All the children underwent upper digestive tract endoscopy and biopsy specimens were taken. Helicobacter pylori infection was determined with microscopic examination after Gimsa staining and the rapid urease test and 30 of the children were Helicobacter pylori positive and the other 30 were negative. The relation between the findings and cell proliferation was studied by immunostaining; the status of gastric apoptosis was tested by DNA fragmentation in situ using TdT-mediated dUTP biotin nick end labeling (TUNEL). Immunohistochemical method was used to detect the expression of P53 protein; CagA antibody was tested by Western blotting.

RESULTS(1) The proliferative index and apoptosis index in children with Helicobacter pylori infection with CagA positive gastritis were much higher than those of Helicobacter pylori negative gastritis patients [(11.56 +/- 4.21)% vs. (5.85 +/- 2.21)%, (10.58 +/- 5.31)% vs. (2.86 +/- 0.64)%, P < 0.01]. (2) The proliferative index and apoptosis index in 30 cases with Helicobacter pylori infection with CagA positive gastribis were much higher than 21 cases who were cured by effective drugs [(11.50 +/- 4.11)% vs. (3.74 +/- 2.30)%; (10.58 +/- 4.02)% vs. (3.74 +/- 2.30)%, P < 0.01]. (3) The expression of P53 protein in Helicobacter pylori with CagA positive gastritis children was much higher than that of Helicobacter pylori negative cases [(63% vs 16%), P < 0.1].

CONCLUSIONCagA positive Helicobacter pylori infection with gastritis improved gastric epithelial cell proliferation and apoptosis. The abnormal expression of P53 protein in gastric epithelium may play an important role in regulation of the processes.

Antibodies, Bacterial ; blood ; Antigens, Bacterial ; immunology ; Apoptosis ; Bacterial Proteins ; immunology ; Biopsy ; Cell Proliferation ; Child ; Child, Preschool ; Epithelial Cells ; metabolism ; Female ; Gastric Mucosa ; pathology ; Gastritis ; complications ; pathology ; Helicobacter Infections ; complications ; pathology ; Helicobacter pylori ; Humans ; In Situ Nick-End Labeling ; Male ; Tumor Suppressor Protein p53 ; metabolism

OBJECTIVETo explore a simplified and reproducible approach for the diagnosis and morphologic prognostication of gastrointestinal stromal tumor (GIST).

METHODSEighty-five cases of gastrointestinal mesenchymal tumors including 74 cases of GIST, 8 esophageal smooth muscle tumor, 1 rectal leiomyosarcoma, 1 Schwannoma, and 1 malignant fibrous histiocytoma were studied by histological evaluation along with an immunohistochemistry panel including vimentin, CD117 (c-kit), CD34, SMA, desmin and S-100. Clinicopathological correlation was performed in 31 cases of GIST that had accompanied with the available follow-up data.

RESULTSAmong 74 GISTs, 34 arose principally from the stomach, 30 from the small intestine, and 10 other cases found in the esophagus, retroperitoneum, mesenterium and omentum. The patients' age ranged from 23 to 80 years (mean 52.5 years), with 45 males and 29 females. Histologically, the tumors composed of either spindle or oval to round cells arranged in interlacing fascicles forming whorls or cellular clusters, cytoplasm generally abundant and eosinophilic. There were 48 cases of spindle cell type, 10 cases of epithelioid cell type and 16 cases of mixed cell type. All 74 cases of GIST were positive for CD117 in a cell membranous pattern, however, some variable staining patterns of CD117 had been noticed in a few cases. In addition, 54 GISTs were also positive for CD34 (72.9%), 25 cases positive for SMA, 5 cases positive for S-100 and 5 cases positive for desmin. According to the Fletcher's scheme, GISTs in this study were divided into 4 subcategories including groups of very low risk of aggressive behavior (3 cases), of low risk (15 cases), of intermediate risk (36 cases) and of high risk (20 cases) respectively. Kaplan-Meier survival analysis of 31 GIST cases whom had been followed up for 16 to 72 months showed a statistically significant difference present among the subcategories (P < 0.01).

CONCLUSIONSGISTs predominantly occur in the middle and old age patients, more common in male, and positive CD117 staining is considered to be the defining marker to differentiate GIST from other mesenchymal tumors of the GI tract. Positive CD34 immun-staining, plus a CD117 positivity, strengthens further a diagnosis of GIST. Subclassification of GISTs using Fletcher's scheme appears to be simple, reproducible, and correlates well with the clinical behavior of the tumor.

Actins ; metabolism ; Adult ; Age Factors ; Aged ; Aged, 80 and over ; Antigens, CD34 ; metabolism ; Disease-Free Survival ; Female ; Follow-Up Studies ; Gastric Mucosa ; pathology ; ultrastructure ; Gastrointestinal Stromal Tumors ; immunology ; pathology ; Humans ; Male ; Middle Aged ; Neoplasm Invasiveness ; Proto-Oncogene Proteins c-kit ; metabolism ; S100 Proteins ; metabolism ; Sex Factors ; Stomach ; pathology