Epidemiology of <i>Helicobacter pylori</i> infection

Malaty, Hoda M.; Nyrén, Olof

doi:10.1046/j.1523-5378.2003.00163.x

Cited by 73 publications

(64 citation statements)

References 25 publications

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“…In fact, in countries with higher incidence of upper digestive tract cancers, inflammation in the upper digestive tract tends to be more common, while in countries with a higher incidence of lower digestive tract cancers, inflammation in the lower digestive tract tends to be more common. 21,22 For example, Helicobacter pylori infection is regarded as the most important cause of gastric cancer, but some areas have a low incidence of gastric cancer despite a high prevalence of Helicobacter pyroli, 23 , 24 suggesting that other factors might be important in the development of gastric cancer, in addition to Helicobacter pylori infection. Virulenceassociated genes related to Helicobacter pylori may partially explain this enigma; 25,26 our study suggests that oxidative stressrelated dietary factors such as heme iron or zinc intake might also play a role.…”

Section: Discussionmentioning

confidence: 99%

Heme iron, zinc and upper digestive tract cancer: The Iowa Women's Health Study

et al. 2005

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We examined associations among dietary heme iron as a possible pro-oxidant, dietary zinc as a possible antioxidant, and the incidence of upper digestive tract cancer; 34,708 postmenopausal women, aged 55-69 years at baseline who completed a food frequency questionnaire, were followed 16 years. There were 75 upper digestive tract cancer cases (52 gastric cancer and 23 esophageal cancer). When heme iron and zinc were mutually adjusted, in dose-response manners, heme iron intake was positively associated with the risk of upper digestive tract cancer, while zinc intake was inversely associated with risk. After adjusting for age, total energy intake, cigarette smoking and alcohol consumption, relative risks for quintiles of heme iron intake were 1.0, 1.53, 2.15, 3.05 and 2.83 (p for trend 5 0.06) and corresponding relative risks for zinc intake were 1.0, 0.86, 0.42, 0.37 and 0.13 (p for trend < 0.01). Additional adjustment for body mass index, physical activity, hormone replacement therapy, multivitamin intake and intake of saturated fat, vitamin C, vitamin E and folate did not change the results. Higher intake of heme iron is associated with higher risk, while higher intake of zinc is associated with lower, risk of upper digestive tract cancer. ' 2005 Wiley-Liss, Inc.Key words: heme iron; zinc; esophageal cancer; gastric cancer; oxidative stress Although iron is vital for all living organisms, iron is also potentially carcinogenic due to its catalytic effect on the formation of hydroxyl radicals, suppression of the activity of host defense cells and promotion of cancer cell multiplication. 1,2 On the other hand, zinc has antioxidant properties; zinc ions may replace redox active molecules and may induce the synthesis of metallothionein, sulfhydryl-rich proteins that protect against free radicals. 3 At a molecular level, metals such as iron can substitute for zinc and may be responsible for metal-induced DNA damage and carcinogenesis, 4,5 suggesting a close interrelation of the 2 nutrients. Supporting these observations, we recently reported that intake of dietary heme iron, the most bioavailable form of iron, is associated with an increased risk of proximal colon cancer, while intake of dietary zinc is associated with a decreased risk of both proximal and distal colon cancer. 6 Even though various upper digestive tract cancers have been shown to be distinct entities in terms of many risk factors and pathological and/or clinical features, carcinogenesis due to oxidative stress is not a site-specific mechanism. Many known risk factors in carcinogenesis such as infection, inflammation, cigarette smoking, nutrition or alcohol consumption may ultimately be associated with oxidative stress as a unifying underlying mechanism. 7-10 For example, oxidative stress associated with inflammation plays an important role in gastric carcinogenesis as a mediator of carcinogenic compound formation, DNA damage and cell proliferation. 7 Similarly, oxidative stress also has been suggested to be a driving force in the pathogenesis of eso...

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Section: Discussionmentioning

confidence: 99%

Heme iron, zinc and upper digestive tract cancer: The Iowa Women's Health Study

et al. 2005

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“…It colonizes the apical side of human gastric epithelial cells and mucous layer (Benoit et al, 2004;Chambers et al, 2013). It was first isolated in 1982 by Marshall and Warren and was recently found to be probably the most chronic bacterial infection in humans (Rieder et al, 2005), infecting more than half of the human population, especially in developing countries (Malaty, 2007). H. pylori infections are associated with various gastric diseases.…”

Section: Introductionmentioning

confidence: 99%

“…The severity of every infection depends on strain virulence, host susceptibility and environmental factors. Some infected patients are symptomatic, whereas some remain asymptomatic for life (Malaty, 2007). However, 6-20% of infected individuals tend to develop duodenal ulceration, and a small proportion of them will develop gastric cancer.…”

Section: Introductionmentioning

confidence: 99%

Antigenic Proteins of Helicobacter pylori of Potential Diagnostic Value

Khalilpour

Agilan²,

Lee³

et al. 2013

Asian Pacific Journal of Cancer Prevention

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Helicobacter pylori antigen was prepared from an isolate from a patient with a duodenal ulcer. Serum samples were obtained from culture-positive H. pylori infected patients with duodenal ulcers, gastric ulcers and gastritis (n=30). As controls, three kinds of sera without detectable H. pylori IgG antibodies were used: 30 from healthy individuals without history of gastric disorders, 30 from patients who were seen in the endoscopy clinic but were H. pylori culture negative and 30 from people with other diseases. OFF-GEL electrophoresis, SDS-PAGE and Western blots of individual serum samples were used to identify protein bands with good sensitivity and specificity when probed with the above sera and HRP-conjugated anti-human IgG. Four H. pylori protein bands showed good (≥ 70%) sensitivity and high specificity (98-100%) towards anti-Helicobacter IgG antibody in culturepositive patients sera and control sera, respectively. The identities of the antigenic proteins were elucidated by mass spectrometry. The relative molecular weights and the identities of the proteins, based on MALDI TOF/ TOF, were as follows: CagI (25 kDa), urease G accessory protein (25 kDa), UreB (63 kDa) and proline/pyrroline-5-carboxylate dehydrogenase (118 KDa). These identified proteins, singly and/or in combinations, may be useful for diagnosis of H. pylori infection in patients.

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“…pylori is an ectoparasitic Gram-negative bacterium that colonizes the upper gastrointestinal tract of most humans, often shortly after birth [44]. Both acute infection and invasive persistent infection are associated with a chronic inflammatory response [45].…”

Section: Helicobacter Pylorimentioning

confidence: 99%