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| Helicobacter Pylori | ||
| Etiology •Helicobacter pylori (H.pylori) is a curved gram negative rod 3.5 x 0.5um. •Multiple strains of the organism exist | ||
| Pathogenesis •The pathogenesis of H.pylori mediated disease is unclear but may involve cytotoxins, urease production, or cytokine attraction of neutrophils •The recent complete mapping of the genetic code for H.pylori may lead to more progress in this area as well as prevention and cure, | ||
| Epidemiology •H.pylori is found worldwide •The prevalence has a strong inverse correlation with socioeconomic status. •In the U.S. prevalence is at least 50% reaching a maximum after age 50 •The prevalence worldwide is over 60%, reaching close to 100% in some third world countries •The exact mode of spread is not clear but person to person transmission appears important •The true prevalence appears to be increasing as more sensitive and specific screening techniques are developed | ||
| General Gross Description •The gross appearance of H.pylori infection is that of the associated diseases: chronic gastritis, peptic ulcer disease, adenocarcinoma and gastric lymphoma •The gastric mucosa appears normal in the presence of colonization without infection •Examples: | ||
| General Microscopic Description •H.pylori is most commonly seen in the gastric antrum followed by the duodenum and less so in the body and cardia of the stomach. H.pylori in the esophagus is found only in areas of Barrett's esophagus •The organism is S shaped appearing curved, comma shaped, or with a central hump resembling a Napoleonic tricorn hat •H.pylori is gram negative and stains faintly with H&E, but the most common methods of identification are silver or Giemsa stain. Monoclonal antibodies exist but immunoperoxidase staining is expensive and unnecessary for routine use •Tissue invasion is not seen and the organism are found on the cell surfaces and between the microvilli •The organism will not be found in areas of intestinal metaplasia •Examples: | ||
| References • Cotran RS, Kumar V, Robbins SL: Robbins Pathologic Basis of Disease. 5th ed. Philadelphia, W.B. Saunders, 1994, pp. 772. This link will directly take you to the relevant new literature Helicobacter Pylori
| Synopsis by: Martin Nadel, M.D. (T63000E10990)[454]
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