OBJECTIVE: To observe the changes of cell gap junction ultrastructure of gastric epithelial cells in patients with gastric cancer(GC) and precancerous lesion(PL),and to investigate the relation between these changes and H.pylori infection. METHODS: Seventy patients with GC, 88 with PL, and 33 with chronic superfial gastritis (CSG) were studied. H.pylori was detected by rapid urease test,basic fuchsin stain and 14C-urea breath test. The CagA gene of H.pylori was determined by polymerase chain reaction(PCR).The cell gap junction ultrastructure was observed under transmission electronic microscope. RESULTS: Length of junction/unit perimeter of gastric epithelial cells in patients with PL was smaller than that in CSG patients, and the smallest width of the intercellular space was bigger than that in CSG patients. The number of cell junction, the number of junction/unit perimeter, and the length of junction/unit perimeter in patients with GC were all smaller than those in patients with CSG or PL, and its smallest width of the intercellular space was bigger than that in patients with CSG. In patients with GC, the number of cell junction, the number of junction/unit perimeter and the length of junction/unit perimeter in CagA+ H.pylori group were smaller than those in CagA(-) H.pylori group, and its smallest width of the intercellular space was bigger than that in CagA(-) H.pylori group. In PL patients, the intercellular space decreased, and the length of cell junction of gastric epithelial cells became bigger after H.pylori eradication. The length of junction/unit perimeter in patients of H.pylori eradication was bigger than that in patients without eradication, and the smallest width of the intercellular space was smaller than that in patients without eradication. CONCLUSION The changes of cell gap junction of gastric epithelial cells in patients with GC and PL are associated with H.pylori infection especially CagA+ H.pylori infection. Eradication of H.pylori can promote the formation of cell junction.
Adenocarcinoma ; microbiology ; ultrastructure ; Epithelial Cells ; ultrastructure ; Female ; Gastric Mucosa ; ultrastructure ; Helicobacter Infections ; pathology ; Helicobacter pylori ; Humans ; Intercellular Junctions ; ultrastructure ; Male ; Precancerous Conditions ; microbiology ; ultrastructure ; Stomach Neoplasms ; microbiology ; ultrastructure

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

Eradication regimens for Helicobacter pylori infection have some side effects, compliance problems, relapses, and antibiotic resistance. Therefore, alternative anti-H. pylori or supportive antimicrobial agents with fewer disadvantages are necessary for the treatment of H. pylori. We investigated the pH-(5.0, 6.0, 7.0, 8.0, 9.0, and 10.0) and concentration (0.032, 0.064, 0.128, 0.256, 0.514, and 1.024 mg/mL)-dependent antibacterial activity of crude urushiol extract from the sap of the Korean lacquer tree (Rhus vernicifera Stokes) against 3 strains (NCTC11637, 69, and 219) of H. pylori by the agar dilution method. In addition, the serial (before incubation, 3, 6, and 10 min after incubation) morphological effects of urushiol on H. pylori were examined by electron microscopy. All strains survived only within pH 6.0-9.0. The minimal inhibitory concentrations of the extract against strains ranged from 0.064 mg/mL to 0.256 mg/mL. Urushiol caused mainly separation of the membrane, vacuolization, and lysis of H. pylori. Interestingly, these changes were observed within 10 min following incubation with the 1 x minimal inhibitory concentrations of urushiol. The results of this work suggest that urushiol has potential as a rapid therapeutic against H. pylori infection by disrupting the bacterial cell membrane.
Anti-Bacterial Agents/chemistry/*pharmacology/therapeutic use ; Catechols/chemistry/*pharmacology/therapeutic use ; Cell Membrane/drug effects/ultrastructure ; Helicobacter Infections/drug therapy ; Helicobacter pylori/*drug effects/ultrastructure ; Humans ; Microbial Sensitivity Tests ; Microbial Viability/drug effects ; Molecular Structure ; Rhus/*chemistry

OBJECTIVETo investigate the effect of Helicobacter pylori-encoded CagA on biological behavior of gastric adenocarcinoma AGS cells.

METHODSWith experiment-control system of the wild-type CagA positive strain and isogenic CagA negative mutant strain of Helicobacter pyroli (Hp) were used as control and experimental groups, respectively. The cell contact, migration and invasion were examined by light and electron microscopy and invasion assay.

RESULTSThe AGS cells infected by Hp strain with positive wild-type CagA showed more severely changed tight junction, wider intercellular space, loss of cell contacts, and higher migrating and invasive ability.

CONCLUSIONHp CagA may lead to loss of cell contacting and higher migrating and invading ability of gastic cells, and accelerates the malignant progress of tumor.

Adenocarcinoma ; microbiology ; pathology ; ultrastructure ; Antigens, Bacterial ; genetics ; Bacterial Proteins ; genetics ; Cell Line, Tumor ; Cell Movement ; Extracellular Space ; Helicobacter pylori ; genetics ; pathogenicity ; Humans ; Intercellular Junctions ; ultrastructure ; Mutation ; Stomach Neoplasms ; microbiology ; pathology ; ultrastructure

BACKGROUND: The adhesion of H. pylori to the gastric epithelial cells may be an essential step for the pathophysiology of various H. pylori-induced gastrointestinal diseases. The purpose of this study was to investigate the ultrastructural relation of H. pylori and gastric epithelial cells in their adhesion. METHODS: Endoscopic biopsy of gastric antrum and body was performed from 15 patients (9 men, 6 women) with chronic gastritis and H. pylori infection. The specimens were processed for electron microscopy and observed with a transmission electron microscope (Hitachi H-600). RESULTS: On the basis of morphological appearances, the adhesions of H. pylori to the gastric epithelial cells were categorized into three types; filamentous connection, adhesion pedestals and membrane fusion. Coccoid and undetermined forms adhered mainly by the filamentous connection, whereas the bacillary forms adhered primarily by the adhesion pedestals and membrane fusion. CONCLUSION: Various types of adhesion were associated with H. pylori and gastric epithelium. Further studies are needed to evaluate the influence of different types of adhesion to the pathophysiology of H. pylori.
*Bacterial Adhesion ; Endoscopy, Gastrointestinal ; Female ; Gastritis/*microbiology/pathology ; Helicobacter Infections/*microbiology/pathology/physiopathology ; Helicobacter pylori/classification/physiology/*ultrastructure ; Human ; Male ; Microscopy, Electron ; Middle Age ; Stomach/*microbiology/pathology ; Support, Non-U.S. Gov't

The occurrence of Helicobacter pylori(H.pylori) and its relationship with gastric mucosa were studied by light and electron microscopy and culture of biopsy specimens from gastric mucosa of 160 patients with upper gastrointestinal symptoms. H. pylori were present in 96.6% of patients with active chronic gastritis, 100% of patients with duodenal ulcer and 76.9% of patients with gastric ulcer, while present in only 6.3% of individuals with histologically normal gastric mucosa. The bacteria colonized the antral mucosa more frequently than the body or than the duodenal cap mucosa. The bacteria were rarely seen in the intestinalized epithelium per se, but there was no significant difference in prevalence of H. pylori between gastritis with intestinal metaplasia and gastritis without intestinal metaplasia. H. pylori could be seen in close association with the surface of gastric epithelial cells below the mucus layer without evidence of intracellular parasitism, All of the strains tested were susceptible to penicillin, erythromycin, and most of them susceptible to tinidazole and bismuth salts. It is concluded that H. pylori are highly associated with gastritis and peptic ulcer diseases and its prevalence rates in patients with those diseases is higher than in developed countries. This strong association of H. pylori infection with gastritis and peptic ulcer diseases suggest a possible etiologic role for the bacterium in those diseases.
Adolescent ; Adult ; Aged ; Chronic Disease ; Duodenal Ulcer/*microbiology/pathology ; Female ; Gastric Mucosa/microbiology/pathology/ultrastructure ; Gastritis/*microbiology/pathology ; *Helicobacter Infections ; Helicobacter pylori/*isolation & purification ; Human ; Male ; Middle Aged ; Prospective Studies ; Stomach Ulcer/*microbiology/pathology ; Support, Non-U.S. Gov't