Endotoxin is an important contributor to Helicobacter induced gastritis

April 1 9 9 5

Esophageal, Gastric, and Duodenal Disorders

SUPPRESSION OF ACID SECRETION INCREASES AMMONIAINDUCED GASTRIC DAMAGE. H. Saita, M. Murakami, H. Dekigai. S. Kusaka, K.Asagoe, K. Shigelnoto, T.Kita. Dept. of Gastroenterology, Hyogo Prefect. Amagasaki Hospital. Hyogo, Japan, and Dept. of Geriatric Medicine, Kyoto University, Kyoto, Japan. It has been well established that suppression of gastric acid accelerates healing of peptic ulcers. However, little is known on the effect of long-term treatment of I-I2 receptor antagonists (H2 RA) or proton pump inhibitors (PPIs) on the gastric mucosa with H.pylori (Hp) infection, under acidic conditions, ammonia reacts with HC1 to form non-toxic NH4C1 instead of cytotoxic NH2CI. The aim of the present study was to evaluate the effect of suppression of acid secretion on the protection of the gastric mucosa with Hp. METHODS: Male SD rats, deprived of food for 24 hr, were anesthetized with urethane and an ex vivo gastric chamber was prepared. Control rats were subjected to exposure of stomach to 1 ml of urease solution (100U/ml) and lml of 60 mM urea solution (pH7). after ischemia of the gastric mucosa (withdrawal of 3 ml of blood from femoral vein) was induced. A pretreatment of H2 RA (famotidine 5rag/rat, i.m.) was given 1 hr before the ischemia and the exposure to urea with urease. Severity of mucosal damage in the corpus was evaluated by potential difference (PD) for 60 rain, and total area of lesions (ulcer index; mm 2) 60 min" after induction of injury. RESULTS: 1) PD were shown in the table (-mV, *p~0.05 VS control). Control

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10 rain

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2) Ulcer indexes in control rats and H2 RA-pretreated rats were 1.8 + 1 . 0 a n d 10.7-----4.6 mm z, respectively. CONCLUSIONS: Gastric lesions, induced by the exposure to urea and urease, developed more severely by production of NH2CI under the condition of suppression of acid secretion. This result suggests that long-term treatment of PPIs or H2 RA may induce deleterious effect on the H/yinfected mucosa.

• CLARITHROMYCIN FOR THE CURE OF HELICOBACTER PYLORI INFECTION: ONE OR ]3NO WEEKS OF TREATMENT? S.Salandin, G.Battaglia*, N. Dal Bo', P.E. Lecis*, A. Pilotto*, M. Ferrana, F. Vianello, S. Kusstatscher, F. Di Mado. Depts. of Gastroenterology of Padua and *Venice. Dept. of Geriatrics of Vicenza. Italy. Clarithromycin has been claimed to be effective in eradicating Helicobacter pylori (Hp) infection. Aim of the study was to verify whether a one-week schedule of treatment with this antibiotic is comparable to a two-weeks schedule, in association with other antimicrebial and or antisecretory drugs. Design. Open, prospective study with two treatments: Group A) 20 mg bid Omeprazole plus 250 mg bid Cladthromycin plus 250rag qid Metronidazole for 14 days (50 patients; 30 M, 20 F; mean age 48 yrs; range 27-82); Group [3) 20 mg bid Omeprazole plus 250 mg bid Clarithromycin plus 250 mg qid Metronidazole for 7 days (53 patients; 33 M, 20 F; mean age 57.8; range 33-79). Methods. All patients were submitted to endoscopy and histological Hp-determination of 7 antral and body biopsies by two tests (modified Giemsa staining and urease-test CLO-test, Delta-West, Australia). At the end of treatment, patients were left untreated for 2 months until endoscopy and the same sample of biopsies was repeated. Statistical analysis was performed by means of of Fisher's exact test. Results. The two groups were comparable for smoking habit and alcohol consumption. Group A) 9 patients dropped-out; the Hp cure rate was 95.1% (39/2). Group B) 3 patients dropped-out; the Hp cure rate was 88% (44/6). Conclusions: 1) Triple therapy with Clarithremycin is very useful curing Hp-infection; 2) No statistically differences were found between one week and two weeks schedules of treatment.

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E N D O T O X I N IS AN I M P O R T A N T CONTRIBUTOR TO HELICOBACTER INDUCED GASTRITIS T Sakagami, T Shimoyama, J O'Rourke, M Dixon, R Howlett, A Lee. University of New South Wales, Sydney, Australia. Hygo College of Medicine, Hyogo Japan. University of Leeds, Leeds, UK. The endotoxin (lipopolysaceharide, LPS) of Helicobacter has been shown to have low biological activity in standard assays. This has been proposed to be a consequence of a highly evolved hostparasite relationship and H.pylori LPS was cbnsidered unlikely to play a major role in pathogenesis. The availability of the C3H/HeJ strain of mice which is unresponsive to LPS allowed testing of this hypothesis as the closely related helicobacter, H.felis, is known to infect mice inducing a gastric pathology.

Methods Specific Pathogen Free C3H/HeJ mice (Non LPS responders) and the congenic C3H/He mice (LPS responders) were infected with Hfelis. At 1,2,6 months post infection gastric pathology was assessed using a standard three point scale for chronic inflammation (CI), activity (Act) and atrophy (Atr). Uninfected mice of the same age were included as controls Results Mouse strain

Average histopathological grading per mouse x/3 Antrum Body (~ Act Air Cl Act Atr Total

C3H/I-Ie 6 mth infected 0.7 0.2 0 2.2 1.4 2.5 7 C3H/HeJ 6 mth infected 0.3 0.1 0 0.9 0:.6 0.5 2.4 Dramatic differences in pathology were seen between the six month H.fells infected C3H/He and C3H/HeJ mice. In the LPS responders a severe pathology particularly in the body of the stomach was seen whereas little inflammation was seen in the LPS hyporesponsive C3H/HeJ mice. No significant inflammation was seen in the control uninfected mice. Conclusion Bacterial endotoxin (LPS) plays a major role in the induction of destructive Helicobacter induced gastritis.

HELICOBACTER PYLORI ADHESION PATTERNS AND THEIR RELATION TO GASTRIC EPITHELIAL CELL INJURY.

A. SAMANTA, G. ANANDARANGA~, T. CHEN,, U. BIELENBERG, L. SCHELLHASE, S. M. SMITH, C. J. COBBS. KA. Medical Center, East Orange and New Jersey Medical School, Newark. New Jersey. Adhesion pattems on gastric epithelium at H. pylori contact sites have been categorized as adhesion pedestals which are cellular extrusions that cup the bacteria or indentation sites or abutment adhesions. While adhesion pedestals might be toxic host response similar to enteropathogenic E. coti infection the role of the other forms of attachments to H. pylori related cell injury is unsettled. AIM: Present study was undertaken to analyze patterns of adhesions between H. pylori and human gastric epithelial cells and its relation to ultrastructural gastric cell injury. METHODS: 15 sets of gastric epithelial cell (KATO HI) cultures treated with in-vitro adhesion system for H. pylori and gastric antral biopsies from 25 H. pylori positive patients with duodenal ulcer and/or dyspepsia were examined for morphology of adhesion and gastric epithelial cell injury under electron microscope. Gastric epithelial cells were cultured in RPMI-1640 medium supplemented with fetal bovine serum and antibiotics. The cultured epithelial cell monolayer was washed with phosphatebuffered saline (PBS), overlaid with suspension ofH. pylori (108 CFU/ml) for 3.5 hours, washed with PBS to remove non adherent bacteria and adherent bacteria were fixed in glutaraldehyde for electron microscopic studies. RESULTS: 1. In tissue culture and biopsy specimens, abutment adhesion was the most common and pedestal formation was the less frequent type of attachment. 2. Gastric cell injury comprised of loss of mierovilli, cell membrane bleb formation, vacuolation and mucin degranulation. Irrespective of the type of attachment these changes were comparable in cells showing bacterial adhesions. ADHESION SITES ANALYZED PEDESTAL INDENTATION ABUTMENT BIOPSIES

19 (25%)

25 (32%)

33 (43%)

CULTURE

7 (19%)

II (31%)

18 (50%)

CONCLUSIONS: H. pylori related gastric cell injury occurs in cells adhered to the bacteria irrespective of the morphologic type of attachment.

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