(taken from the application) Helicobacter pylori (Hp) is a common worldwide infection; it is now known to be etiologically related to gastritis, peptic ulcer disease, gastric adenocarcinoma, and primary gastric lymphoma. The outcome of Hp infection differs among different ethnic groups. For example, in the United States although Hp infection is detected in all ethnic groups, gastric cancer is more common in Hispanics, Blacks, Vietnamese, Koreans, Japanese, and American Indians, compared to the white population. Possible factor(s) responsible for these differences include subtle distinctions in host or environmental factors (e.g., in diet) or differences in virulence in the common Hp strain(s) circulating within an ethnic group. While environmental or host factors are likely to be important, differences in virulence is a likely possibility because in many other bacterial diseases the expression of a disease can be directly related to specific virulence factors. Data from a number of laboratories suggest that different groups of Hp strains exist. Putative virulence markers, such as cagA and vacA genes and their protein products, have also been identified and they may be differentially present or expressed in different Hp-related gastrointestinal diseases. Our primary hypothesis is that different disease manifestations of Hp infection in different ethnic groups is a reflection of the heterogeneity and expression of different virulence factors in the predominant Hp strain(s) circulating in the ethnic group. The specific objectives of this study are: To determine whether the presence of Hp virulence factors, including genetic and/or phenotypic variations in Hp isolates within different ethnic groups in the US, can be correlated with severity, extent, or pattern of gastritis. We also plan to use the DNA fingerprinting method, REP-PCR, to assess genetic similarity among Hp isolates within and between different ethnic groups. This study will also determine whether differences in prevalence and heterogeneity of specific candidate virulence factors may be the underlying mechanism leading to differences in the extent and severity of Hp-related gastric damage and diseases in different ethnic groups in the United States.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK053659-03
Application #
2906166
Study Section
Special Emphasis Panel (ZDK1-GRB-8 (O2))
Program Officer
Hamilton, Frank A
Project Start
1997-09-30
Project End
2001-09-29
Budget Start
1999-09-30
Budget End
2000-09-29
Support Year
3
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Baylor College of Medicine
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
074615394
City
Houston
State
TX
Country
United States
Zip Code
77030
Shiotani, Akiko; Opekun, Antone R; Graham, David Y (2007) Visualization of the small intestine using capsule endoscopy in healthy subjects. Dig Dis Sci 52:1019-25
Graham, David Y; Opekun, Antone R; Willingham, Field F et al. (2005) Visible small-intestinal mucosal injury in chronic NSAID users. Clin Gastroenterol Hepatol 3:55-9
Graham, David Y; Opekun, Antone R; Jogi, Medhavi et al. (2004) False negative urea breath tests with H2-receptor antagonists: interactions between Helicobacter pylori density and pH. Helicobacter 9:17-27
Graham, David Y; Opekun, Antone R; Hammoud, Fadi et al. (2003) Studies regarding the mechanism of false negative urea breath tests with proton pump inhibitors. Am J Gastroenterol 98:1005-9
Kim, Jae J; Kim, Jong G; Kwon, Dong H (2003) Mixed-infection of antibiotic susceptible and resistant Helicobacter pylori isolates in a single patient and underestimation of antimicrobial susceptibility testing. Helicobacter 8:202-6
Sakai, Taro; Fukui, Hirokazu; Franceschi, Franchesco et al. (2003) Cyclooxygenase expression during Helicobacter pylori infection in Mongolian gerbils. Dig Dis Sci 48:2139-46
Hsu, Ping I; Hwang, Il-Ran; Cittelly, Diana et al. (2002) Clinical presentation in relation to diversity within the Helicobacter pylori cag pathogenicity island. Am J Gastroenterol 97:2231-8
Nurgalieva, Zhannat Z; Malaty, Hoda M; Graham, David Y et al. (2002) Helicobacter pylori infection in Kazakhstan: effect of water source and household hygiene. Am J Trop Med Hyg 67:201-6
Yamaoka, Yoshio; Orito, Etsuro; Mizokami, Masashi et al. (2002) Helicobacter pylori in North and South America before Columbus. FEBS Lett 517:180-4
Yamaoka, Yoshio; Kita, Masakazu; Kodama, Tadashi et al. (2002) Helicobacter pylori infection in mice: Role of outer membrane proteins in colonization and inflammation. Gastroenterology 123:1992-2004

Showing the most recent 10 out of 24 publications