The primers 1254 (CCGCAGCCAA) and 1281 (AACGCGCAAC) were used, and the results were analyzed by gel electrophoresis as explained previously (14). == Table 1. gastric malignancy and gastric mucosa-associated lymphoid tissue (MALT) lymphoma (1-7). Although many studies have been performed onH. pylori, the pathogenesis ofH. pyloriinfection has not been determined. However, several factors such as the vacuolating cytotoxin (vacA) and the cytotoxin-associated protein (cagA) have been implicated inH. pylorivirulence (1-10). The Nrp2 cryptic genecagA, not present in allH. pyloriisolates, is usually a marker forH. pyloriisolates with enhanced conversation with epithelial cells; it encodes a highly immunogenic, variably sizedcagAprotein (120-140 kDa) (3). The size variance, of thecagAprotein, has been correlated with the presence of several repeat sequences located in the 3′ region of the repeat reading frame (9). Sequencing of thecagAgene has revealed that this 3′ repeat region (3’RR) has a variable fragment length due to internal duplication (3,6,11). Even though biological function of 3’RR is not known, 3’RR is usually thought to escape immunity by generation of either antigenic diversity or immunodominant nonprotective epitopes (3,6,10). Prior studies have indicated that some repetitive types of 3’RR are related to gastric histological changes. And recent genetic analysis has revealed that the length of the 3’RR is usually associated with gastric disease, such as peptic ulcer, gastric atrophy and malignancy (12,13). However, it is not clear whether variations of the 3’RR are responsible for certain clinical outcomes, changes in the gastric environment or whether the variance of the 3’RR oncagAis related to geographic differences. Therefore, the aim of this study was to determine whether the 3’RR variations are related to geographic or clinical manifestations, and whether the variations occur in the same isolates colonizing different locations of the belly. == MATERIALS AND METHODS == == Study subjects == We examined 78 patients from four countries; 25 Asian patients from Hong Kong (9 patients with duodenal ulcer [DU], 8 patients with gastric malignancy [GC] and 8 patients with non-ulcer dyspepsia [NUD]), 17 white patients from the USA (7 patients with DU and 10 patients with NUD), 8 Indian patients from India (8 patients with NUD), and 28 Asian patients from Japan (16 patients with DU, 6 patients with GC and 6 patients with NUD). Biopsies were taken from the gastric cardia, body and antrum in the patients from the USA and India. Biopsies were obtained from the gastric antrum in the patients from your other countries. The present study was approved by the institutional evaluate table at Kyungpook National University Hospital and informed consent regarding the study and any invasive procedures was obtained from all the patients. == Growth ofH. pyloriand DNA isolation == The biopsy specimens were cultured on Trypticase soy agar plates made up of 5% sheep’s blood (BBL Microbiology Systems, Cockeysville, MD, USA) at 37 in ambient air flow made up of 5% CO2for at least 5 days under microaerobic conditions (Campy-pak systems; BBL, Cockeysville, MD, USA). For growth in Tasidotin hydrochloride the liquid culture, Brucella broth made up of 10% FBS supplemented with 50 mM potassium phosphate buffer was inoculated withH. pyloricells harvested from 48 hr Trypticase soy agar/sheep’s blood plates and inoculated for 24 hr at 37 in a 5% CO2atmosphere. After 24 hr incubation, the organisms were recognized asH. pylorion the basis of Gram stain morphology, colony morphology and positive urease, catalase and oxidase activities. == Preparation of genomic DNA == Chromosomal DNA was prepared from your cells of each isolate after 48 hr of growth on two agar plates; the genomic DNA from your cultures of the isolates was extracted by guanidine thiocyanate (GES, EDTA and sarkosyl), chloroform extraction and isopropanol precipitation. The polymerase chain reaction (PCR) and sequencing was performed with units of oligonucleotide primers shown inTable 1. The primers were designed based on the knowncagAsequences Tasidotin hydrochloride ofH. pyloristrain 84-183 (Genbank accession number 211714) (Fig. 1). Because diverse isolates were expected in various races from geographic diversity, primers forcag3/4andcag5/6were Tasidotin hydrochloride used differently. Thecag5/6primers experienced a broader range than thecag3/4among these geographically diverse isolates. The PCR reaction was performed with 10 mM Tris/HCl (pH 8.3), 1.5 mM MgCl2, 200 M (each) deoxynucleotides, 2 U of.