Influence of Helicobacter pylori lipopolysaccharide on expression of Cxc chemokines, and their receptors, CXCR1 and Cxcr2, in human neutrophils

correlate with disease seventy Specifically, there was no relationship between babA2 and gastric cancer isolates. While most strains expressed Gml, a proportion of strains from patients with NUD did not exhibit the Gm 1 epitope and were babA2-negative. This study does not support a major role of adherence factors in the development of gastroduodenal disease.

Og invades human host cells directly and might destroy them. This might explain the dyspeptic symptoms of patients with gastritis and erosive ulcers. The intraceUular invasion may not be host cell specific as the organism invades into both gasmc MC and HeLa ceils. Different strains may produce different host cell cytotoxic responses as seen in vitro and in vivo. The intravascular presence of Og suggests that the pathogenesis could be systemic. These results suggest that PVOg is expressed by extracellular and intracellular cytotoxicities on the host cells. Further studies into PVOg including cytotoxic substances produced by Og are warranted.

M896 The Functional Status of The Putative Helicobacter Pylori Adhesin Sahb as a Marker for Clinical Outcome Ramon De Jonge, Raymond G. J. Pot, Ruud J. L. Loffeld, Arnoud H. M. Van Vliet, Ernst J. Kuipers, Johannes G. Kusters

M899 Influence of Helicobacter Pylor/Lipopolysaccharide on Expression of Cxc Chemokines, and Their Receptors, CXCR1 and Cxcr2, in Human Neutrophils Tadashi Shimoyama, Qiang Liu, Shinsaku Fukuda, Shigeyuki Nakaji, Akihiro Munakata

Objective: Helicobacterpylori factors that contribute to disease outcome are largely unknown, but intimate contact to host cells as mediated by outer membrane proteins (OMPs), is thought to play an important role. Expression of the OMPs OipA, HopZ, SabA, and SabB depend on CT-repeats in the coding region of the respective genes. The correlation between the expression status of these four genes and the clinical outcome of colonization with H. pylon was determined in a Dutch population. Methods: H. pylori strains isolated from 95 Dutch patients (28 with gastritis, 28 with duodenal ulcer, 21 with gastric ulcer. 9 with gastric carcinoma, and 9 with lymphoma) were analyzed for the presence of the cog PAl and the on/off expression status of the H. pylon genes oipA, hopZ, sabA, and sabB genes by DNA sequence analysis. Results: The off-statns of sabB and the presence of the cog pathogenicity island were significantly associated with duodenal ulcer (p = 0 0 3 and p = 0.04 respectively). The expression status of oipA, hopZ, and sabA did not correlate with clinical outcome. Furthermore, lymphoma strains appear to express a significant smaller amount of putative adhesins when compared to gastritis, gastric ulcer, duodenal ulcer and gastric carcinoma strains (p = 0.01 for all groups tested). Conclusions: The presence of the cog PAl and the off status of sabB in H. pylori strains are associated with duodenal ulcer disease. SabB may be involved in intimate attachment to host cells and H. pylori strains harboring a functional sabB gene may therefore be more susceptible to phagocytosis

Purpose: Chronic gastritis induced by H. pylori is charactensed by considerable neutrophil infiltration into the gastric mucosa. CXC chemokines are increased in H. pylori infected mucosa and play an important role in migration and activation of neutrophiLs. The aim of this study was to examine the effects of H. pylori LPS on mRNA expression of CXC chemokines and their receptors in human neutrophila. Methods: Neutrophils were isolated from 6 healthy volunteers using Histopaque density gradient separation. Each well of a 96-well microplate was added with neutrophil suspension and H. pylori LPS (1-100 ng/ml). After incubation for 0.5-3.0 h, celLs were separated by centnfugation. Total RNA was extracted from the pellet and semi-quantitative RT-PCR was performed to quantify mRNA expression of CXC chemokines (IL-8 and ENA78) and CXC chemokine receptors (CXCR1 and CXCR2) in neutrophils using GAPDH as an internal control. Results: Incubation with H. pylon LPS increased IL-8 mRNA expression of neutrophils significantly (p<0.05) while expression of ENA78 was not observed. On the other hand, expression of CXCR1 and CXCR2 mRNA was observed in both LPS-treated and untreated neutrophils. The ratio of CXCR1 or CXCR2/GAPDH mRNA expression was not affected by H. pylorl LPS within the studied conditions. Discussion: H. pylon LPS stimulates expression of IL-8, a menmber of CXC chemokines. While expression of CXCR1 and CXCR2, the important receptors of CXC chemokines, was not affected by H. pylori LPS. H. pylori LPS may contribute to the pathology of H. pyloriinduced gastritis, which has considerable neutrophil infiltration with small invasion of bacteria into the gastric mucosa, through stimulating IL-8 production but not modulating expression of CXC chemokine receptors.

M897 Relationship Between Helicobacter Pylori Restriction Endonuclease-Replacing G ene, Hrga and Clinical Outcome Hong Lu, David Graham, Shudong Xiao, Oscar Gutierrez, Yoshio Yamaoka Background: Recently, polymorphisms in the hpyII1 locus in Heficobacter pylari have been identified and the presence of a new gene, hrgA, that had replaced hpyIlIR, was reported to be related to gastnc cancer in Asian strains (Cancer Res. 2002;62:2385-2389). However, this relation was data-denved and the hypothesis has not yet been confirmed. Aims: To confirm the relationship between hrgA afiefic type and clnilcal outcome in strains from both Asian and Western countries. Methods: We examnied H. pylon strains from Asia (Korea, Hong Kong, Thailand, Taiwan, and Vietnam) and Western countries (Colombia, Canada, France, and Italy). hrgA and hpyllIR status were determined by polymerase chain reaction (PCR). Results: There were 332 strains including as 172 Asian (49 cancer, 123 non-cancer) and 160 Western strains (50 gastric cancer, 90 non-cancer). The prevalence of hrgA gene was significantly higher in Western strains 46.8% than Asian strains (33.7%) irrespective of the clinical outcome (p = 0.01). In Asia, the prevalence of hrgA gene was 34.7% in strains from cancer and 33.3% from non-cancer. In Western countries, the prevalence of hrgA gene was 50% in strains from cancer and 45% from non-cancer. Discussion: We were unable to confirm the hypothesis that the hrgA gene was related to gastric cancer. We found no relationship between the prevalence of the hrgA gene and clinical outcome in either Asian or Western counties The prevalence of hrgA gene was higher in Western strains compared with Asian strains which are the opposite of other important putative virulence factors such as cog pathogenicity island, vacA sl genotype, babA2 genotypes arid oipA "on" types

M900 H pylori Antigens, Serum Pepsinogen and Ethnic Difference in Gastric Cancer Incidence in an Asian Population Tling Leong Ang, Kwong Ming Fock, Subbiah Dhamodaran, Tay Meng Ng, Eng Kiong Teo, ]essica Tan Background and aim: Singapore is an urban Asian society comprised mainly of Chinese, Malays and Indians. The Chinese has the highest incidence of gastric cancer (GC), and this had been correlated with H pylori (Hp) seroprevalence in the case of Chinese and Malays, but not Indians. Low serum pepsinogen I (P1) and pepsinogen l:II ratio (PI:I1) are associated with GC and its precursors such as atrophic gastritis/intestinal metaplasia. We had shown that kDa19.5 seropositivity and kDa35 seronegativity were associated with GC in Chinese patients. We aim to determine if the ethnic difference in GC incidence may be due to different prevalence of atrophic gastritis or specific Hp strains. Method: Specific Hp antigens (kDa19.5, kDa30, kDa35, VacA, CagA) were determined using Western blot (Helicoblot 2.0). Pepsinogen levels were determined using ELISA (Elken). The manufacturer's definition for pepsinogen positivity (PI <70ng/ml and PHI <3) was validated locally by comparing patients who underwent gastroscopy and was diagnosed to have non ulcer dyspepsia (NUD) against those with GC. A total of 595 sera obtained from the 3 ethnic groups in the community were analyzed for differences in serum pepsinogen and Hp antigens. Results: The difference in pepsinogen posinvity between GC and NUD was 38.7% vs 4.3% (p=0.034). Between Chinese and Malays, the seroprevalence in Hp was 47% vs 28% (P<0 0001), but there was no difference in pepsinogen posinvity. Between Chinese and Indians, Hp seroprevalence was not significantly different, but more Indians were seronegative for kDa35 antigen (80.9% vs 65.3%, p
M898 Pathogenic Virulence of Okadaella Gastrococcus(PVOg): Uhrastructural Studies

In Vivo and In Vitro Takayuki Okada, Malcolm Jones, Jeffrey Sear[e, Graham Adkins, Jenny Robson, Rodny McDougall, John Bradley We have reported the presence of Og in Helicobacter pylori(Hp) positive and negative gastropathy patients. Og can be found in pre-neoplastic gastric lesions and malignancy. The pathogenic significance of this organism has not been reported as yet. The aim of this study was to investigate PVOg under transmission electron microscopy (TEM) in vivo and in vitro. MethodTEM was performed on the gastric biopsy specimens of the patients complaining of dyspeptic symptoms,in addition to H&E,WSS,AYTB,in some cases Hp immunoperoxidase stain,and DICM studies. All specimens were found to be Hp negative by histology,culture,and urease tests. Og isolated from a patient who suffered from dyspepsia and found to have active chronic gastritis and gastro-esophagitis,were inoculated with HeLa ceils to examine PVOg HeLa cells inoculated ,sath Og for 4 bours(hs) were examined under TEM. HeLa ceils were inoculated with a saline without Og as a control. ResultsOg were found in mucosa,lamina propria,intercellufar space,intracellularly,penvascularly,intravascularly. Og attaches on the mucosal cells(MC) and invades directly into the cells in vivo. Some of MC infected with Og undergo degeneration and necrosis The presence of Og in the intracellular vacuoles was also noted in vivo. Adherence of Og via pill-like structures(PLS) to the nucleus of the mucosal cell was found in the patients with intestinal metaplasia and dysplasia. There was mild cellular distortion in Og infected HeLa ceils but no significant cellular destruction was seen at 4hs. All HeLa cells were destroyed by 24 hs but control cells were unaffected. TEM on 4hs postinfection HeLa cells identified multiple intracellular Og and some of them attached to the nucleus of the cell via PLS. No intracefiular vacuolation associated with Og invasions were seen in viuo. ConclnsionThis study provides the first definitive evidence that

AGA Abstracts

M901 Assessment of Helicobacter pylori Prevalence in a Community with High Risk for Distal Gastric Cancer Luzmary Vasquez-Cordero, Guillermo I. Perez-Perez, Asalia Z. Ofivares, Simon Peraza, Jorge H. Virus, L. Carreno, R. Garcia, Maria Gloria Dominguez Bello Background: H. pylori has been associated with the etiology of gastric cancer, and some bacterial and host genotypes are found to be associated to increase the nsk for this disease. Specific areas in the Andes region of South America have an unusually high prevalence of distal gastric cancer (GC). In particular in Venezuela, the Tachira State has the highest GC mortality rate for the country. Aim: To assess for differences in H. pylon infection in relation

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