الفهرس 
Materials and MethodsOnly 14 pages are availabe for public view
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Abstract
H.pylori is a gram negative spiral bacterium . it could be found in any part of the stomach , but most coimmonly in the antrum , and its presence is almost always associated with inflammation near the surface apithalium. It plays an important role in the pathogenesis of gastritis , peptic ulcer , and gasteic cancer . proposed mechanisms for the carcinogenic effect of H.pylori include the eeduction of the gastric antioxidant ascorbate and the stimulation of epithelial cell proliferation H.pylri has been identified as a definite gastric carcinogen . It is one of the most prevalent infection in humans worldwide, causing infection of < 50 % of adults in developed countries and nearly 100% in developing countries . eradication of H.pylori speeds up ulcer healing . so, detection of H.pylori infection is of great importance . diagnasis of H.pylori infection can be performed by various methods . direct methods such as histology , culture, pcr, or the rapid urease tests , rely on specimens obtained by the endoscopy . these tissuebased tests are highly specific but less sensitive because of variation of H.pylori density in the gastric mucosa , while culture is frequently the gold standard for many infectious diseases . it is not recommended for routine diagnosis of H.pylori infection . its main disadvantages are loweer senaitivity than other diaganostic test , long term around time for results , and higher expense . indirect methods to detect the infection are known , such as serology , and urea breath testing ( UBT) . the ubt is expensive and not approved for a pregnant women or in children . several new methods for detecting H.pylori have been described and include detection of antibodies in saliva and urine . however , detection of antibodies is less specific and not useful for follow up .