OBJECTIVETo determine the distributions of six Helicobacter pylori (Hp)-specific antibodies in a high-risk population of gastric cancer (GC) and explore the relationship between Hp virulence factors and precancerous gastric lesions.

METHODSBased on the two intervention trials conducted in Linqu County, the seropositivities for CagA, VacA, GroEL, UreA, HcpC and GGT were assessed by recombinant immunoassay (recomLine) in 623 participants with H. pylori infection determined by (13)C-urea breath test ((13)C-UBT) and/or enzyme linked immunosorbent assay (ELISA).

RESULTSIn a total of 623 participants were detected by recomLine analysis, of which 594 were Hp-positive. The seropositivities rates of CagA, VacA, GroEL, UreA, HcpC and GGT were 84.0%, 38.2%, 66.7%, 17.7%, 58.8% and 42.8%, respectively. A total of 523 participants were determined as type I infection of Hp, accounting for 88.1%. Compared with superficial gastritis (SG), the infection rate of Hp type I was higher in the chronic atrophic gastritis (CAG) (P = 0.001).

CONCLUSIONSThe results of this population-based study suggest that the virulence factors of Hp may be related to the development of GC in a Chinese high-risk population. The recomLine analysis may serve as a tool for identification of Hp strains and prediction of high-risk population of GC.

Adult ; Antibodies, Bacterial ; blood ; Female ; Gastritis ; blood ; immunology ; microbiology ; Gastritis, Atrophic ; blood ; immunology ; microbiology ; Helicobacter Infections ; blood ; immunology ; Helicobacter pylori ; Humans ; Male ; Middle Aged ; Precancerous Conditions ; blood ; immunology ; microbiology ; Stomach Neoplasms ; blood ; immunology ; microbiology

In vitro subcultures of bacteria can lead to genetic and phenotypic changes. This study aimed at investigating the effect of repeated subcultures on the adhesion, motility, cytotoxicity, and gastric inflammation caused by Helicobacter pylori. H.pylori SS1 strain was subcultured 64 times on agar plates containing Brucella broth and 5% bovine calf serum. The adhesion, motility, cytotoxicity, and gastric inflammation produced in Mongolian gerbils were compared between the first and 64th subcultured strain. The adhesion rates, following 3 hr exposure of AGS cells to either the first strain or the 64th-transferred strain, were 21% and 12%, respectively. The motility of the 64th-transferred strain decreased significantly when compared to the 1st strain (9.1 mm vs. 15.1 mm). The cytotoxicity index tended to be higher in the first strain than in the 64th-transferred strain (73.7% vs. 69.2%). The initial infection rate on the gerbils showed no difference between the two strains. However, chronic gastric inflammation of the first strain-infected gerbils was somewhat more severe than that of the 64th-transferred strain-infected gerbils. Therefore, the use of repeatedly subcultured strains of H. pylori in virulence experiments can lead to different results from thoses of the original strain.
Animals ; Bacterial Adhesion ; Gastritis/immunology/*microbiology ; Gerbillinae ; Helicobacter Infections/immunology/*microbiology ; Helicobacter pylori/growth & development/*pathogenicity ; Male ; Virulence

OBJECTIVES: Clinical presentation of Helicobacter pylori (H. pylori) infection has marked variation mainly due to the strain diversity and host susceptibility. Although H. pylori is identified as a major risk factor for gastric and duodenal ulcers, the ulcerogenic or pathogenic strain has not been documented yet. The objective of this study was to investigate antigenic types of the ulcerogenic strain of H. pylori. METHODS: The sera of 64 patients were tested by Western blot using Helicoblot 2.0 for six major anti-H. pylori antibodies, together with CLO test and histological examination of gastric biopsy tissues. Thirty-five, nine and 20 patients had duodenal ulcer, gastric ulcer and chronic active gastritis, respectively. The antigenic types of H. pylori were analyzed in 54 patients with positive H. pylori infection. In this study, H. pylori was divided into four serotypes according to the presence and absence of CagA and VagA: type I; CagA (+) and VacA(+), type Ia: CagA (+) and VacA(-), type Ib: CagA(-) and VacA(+), and type II: CagA(-) and VacA(-). RESULTS: There was no difference in the number of bands for six antigens: 3.2 +/- 1.4, 3.0 +/- 1.2 and 3.1 +/- 1.4 in 35 duodenal ulcer, 7 gastric ulcer and 12 chronic gastritis, respectively. The band with 119 kDa was 90.7%, which was the most common band with the order of 35, 30, 26.5, 89 and 19.5 kDa. Type I, la and Ib were positive in 22.2, 42.6 and 27.8%, respectively, which were significantly higher than type II (p < 0.05). There was no difference in the positive rates of four urease subtypes between the four serotypes.
Adult ; Aged ; Antigens, Bacterial/classification* ; Antigens, Bacterial/analysis ; Blotting, Western ; Chronic Disease ; Comparative Study ; Duodenal Ulcer/pathology ; Duodenal Ulcer/microbiology* ; Duodenal Ulcer/immunology ; Gastric Mucosa/pathology ; Gastric Mucosa/microbiology ; Gastritis/pathology ; Gastritis/microbiology ; Gastritis/immunology ; Helicobacter Infections/immunology* ; Helicobacter pylori/immunology* ; Human ; Middle Age ; Serotyping ; Stomach Ulcer/pathology ; Stomach Ulcer/microbiology* ; Stomach Ulcer/immunology ; Substances: Antigens, Bacterial

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

OBJECTIVES: The significance of the coccoid forms of H. pylori is still controversial and the questions of whether these forms are viable and infective or degenerative are still open. We induced conversion from rod to coccoid forms and studied morphological changes and antigenic evolutions during this conversion and, thereby, elucidated the viability of coccoid forms. METHODS: The H. pylori strain (C001) used for Western blotting was isolated from the patient with gastric cancer. The antigenic evolution during coccoid conversion of H. pylori was studied by Western blotting, using different sera from thirty patients known to be culture positive. These sera were used to reveal the total antigens of the strain cultured for 2 days (100% rod) and 15 days (> 99% coccoid). After SDS-PAGE, with 10% separating gel of total antigens (rod and coccoid), transblotting (Trans-Blot electrophoretic cell, Bio-Rad) was taken onto a nitrocellulose membrane (Bio-Rad). Then, the blots, with human sera diluted at 1/100, were developed with color reaction by goat serum anti-human IgG with alkaline phosphatase and BCIP. RESULTS: The antigenic profiles were not changed in 46.7% (14/30 cases) and were changed in 53.3% (16/30 cases) during coccoid conversion. Antigenic fractions changed during coccoid conversion were protein band at 120 kDa and band at 35 kDa, and were not detected in coccus forms. The rest of the profiles were identical between rod and coccoid forms. The protein which disappeared include CagA (120 kDa) and porin, or adhesin (35 kDa). The morphological changes during coccoid conversion were U shaped at day 7, doughnut shaped at day 9 and full coccoid at day 15. CONCLUSIONS: The results showed that coccoid forms of H. pylori retain cellular structures similar to rod form, and some of the antigens (CagA and porin) disappeared during coccoid conversion. Therefore, coccoid form might be viable and represent one of the stages of H. pylori biological cycle.
Adaptation, Physiological ; Antigens, Bacterial/isolation & purification* ; Gastritis/microbiology ; Helicobacter Infections/microbiology ; Helicobacter pylori/ultrastructure* ; Helicobacter pylori/immunology* ; Helicobacter pylori/growth & development ; Human ; Microscopy, Electron ; Stomach Neoplasms/microbiology ; Virulence

A serologic test for antibodies is useful for diagnosis of Helicobacter pylori(H.pylori) infection in children. We evaluated the reliability of H.pylori IgG antibody titer in grading the severity of infection in children. We surveyed the sero-prevalence of H.pylori infection in 300 healthy school children (13 to 15 years old). Thirty-four percent(102 of 300 children) were sero-positive for H.pylori. Of the 102 sero-positive children, 70 underwent gastroscopic examination. Ninety percent of sero-positive children(63 of 70 children) were proven to be H.pylori infected. All children with H.pylori infection had histologically proven gastritis, and its severity did not correlate with the IgG antibody titer. Although a serologic test is useful to identify H.pylori infection in children, it can not predict the severity of H.pylori associated gastritis.
Adolescent ; Antibodies, Bacterial/*blood ; Gastritis/diagnosis/immunology/*microbiology ; Helicobacter Infections/diagnosis/*immunology ; Helicobacter pylori/*immunology ; Human ; Immunoglobulin G/*blood ; Support, Non-U.S. Gov't

Antibodies, Bacterial ; blood ; Antigens, Bacterial ; biosynthesis ; Bacterial Proteins ; biosynthesis ; Carrier Proteins ; biosynthesis ; Gastritis ; microbiology ; Helicobacter Infections ; immunology ; Helicobacter pylori ; immunology ; isolation & purification ; Humans ; Recombinant Proteins ; biosynthesis

BACKGROUND/AIMS: To evaluate a new monoclonal antibody for Helicobacter pylori urease in gastric tissue. METHODS: A total of 107 volunteers were enrolled. All subjects underwent a 13C-urea breath test and esophagogastroduodenoscopy. Gastric aspirates were analyzed for pH and ammonia. Six biopsy specimens in the gastric antrum and body were obtained for a rapid urease test and histology. The new monoclonal antibody-based H. pylori urease test (HPU) was performed to rapidly and qualitatively detect urease in two biopsy specimens. RESULTS: H. pylori infection was diagnosed in 73 subjects. The sensitivity and specificity of the HPU was 89% and 74%, respectively. The subjects were divided into two groups: one with true-positive and true-negative HPU results (n = 90) and the other with false-positive and false-negative HPU results (n = 17). Across all subjects, ammonia levels were 900.5 +/- 646.7 and 604.3 +/- 594.3 mumol/L (p > 0.05), and pH was 3.37 +/- 1.64 and 2.82 +/- 1.51 (p > 0.05). Sensitivity was higher in the presence of atrophic gastritis or intestinal metaplasia. CONCLUSIONS: HPU detected H. pylori in approximately 10 min. Gastric aspirate ammonia and pH levels did not affect the test results. Sensitivity was good in the presence of atrophic gastritis or intestinal metaplasia.
Adult ; Antibodies, Monoclonal/*immunology ; Bacterial Proteins/*analysis/immunology ; Biomarkers/analysis ; Biopsy ; False Negative Reactions ; False Positive Reactions ; Female ; Gastritis, Atrophic/*diagnosis/microbiology ; Helicobacter Infections/*diagnosis/microbiology ; Helicobacter pylori/*enzymology/immunology ; Humans ; *Immunologic Tests ; Male ; Metaplasia ; Middle Aged ; Predictive Value of Tests ; Pyloric Antrum/*microbiology/pathology ; Reproducibility of Results ; Time Factors ; Urease/*analysis/immunology ; Workflow

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

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