Murine Models of Helicobacter (pylori or felis)-associated Gastric Cancer.

Gastric adenocarcinoma is the fifth most common cancer and third most common cause of cancer-related death in the world. The majority of these cancers develop in genetically susceptible individuals who are chronically infected with the Gram-negative bacterium Helicobacter pylori. Often these individuals have also been exposed to certain environmental factors that increase susceptibility, such as dietary components. Murine models of Helicobacter-induced gastric cancer are valuable tools for investigating the mechanisms responsible for the stepwise pathological changes of chronic atrophic gastritis, intestinal metaplasia, dysplasia and gastric adenocarcinoma. Helicobacter felis colonization greatly accelerates the development of gastric neoplasia in mice, and causes pathologies similar to those observed with Helicobacter pylori-associated gastric carcinogenesis in humans. These mouse models are therefore useful for investigating genetic and environmental factors that may be involved in the pathogenesis and treatment of gastric cancer. Detailed in these protocols are procedures for inducing Helicobacter-associated carcinogenesis in mice as well as the histological analysis and interpretation of gastric pathology in these animals.

Oxygen therapy in patients with chest pain of acute onset: single centre audit experience.

INTRODUCTION: Although oxygen therapy has been commonly used in the treatment of acute coronary syndromes, evidence shows that oxygen administration is not always beneficial to patients with acute chest pain and in certain circumstances may, in fact, be harmful. Hence, several national and international organizations have issued guidelines restricting its use to hypoxic patients only. AIM: To audit and change the inappropriate practice of administering oxygen therapy indiscriminately to patients with acute chest pain. SETTING: Emergency department, coronary care unit and heart assessment centre in a large teaching hospital. METHODS: The authors identified 100 patients who presented with acute chest pain and collected data on oxygen prescription, administration and documentation from clinical notes and observation charts. RESULTS: Only 71% of patients in a hospital setting were correctly assessed for requiring oxygen therapy. After introducing local guidelines and a series of lectures, this rose to 94%. A third audit showed sustained change, with 96% of patients being appropriately assessed for needing oxygen therapy. DISCUSSION: The introduction of local guidelines and a series of lectures improved handling of oxygen in patients presenting with acute chest pain.