Peptic ulcer occurs in the mucous membrane of the intestinal tract. An estimated 90% of peptic ulcers are caused by infection with a bacterium, Helicobacter pylori, strains of which promote the formation of ulcers by causing an inflammtory response in the cells of the stomach wall, making it more susceptible to the hydrochloric acid secreted by the stomach. Most commonly, it occurs in the stomach (gastric ulcer) or at the beginning of the small intestine (duodenal ulcer, the most common form) and causes abdominal pain, especially between meals.
Infection with the H. pylori bacterium, which is also associated with some stomach cancer, is very common, but not all strains promote the formation of ulcers. Approximately 50% of those over 60 in developed countries are infected; in developing countries the infection rate is much higher, and infection usually occurs earlier in life. Experts are as yet uncertain how the bacterium is spread. Around 20% of those infected develop ulcers. Peptic ulcer is found more frequently in men. Heavy aspirin or ibuprofen use and smoking increase the risk of ulcer development.
The connection of H. pylori infection with peptic ulcer was made in the early 1980s by Australian scientists Barry J. Marshall and J. Robin Warren; it previously was believed that peptic ulcers were caused by emotional stress. Marshall and Warren were awarded the Nobel Prize in physiology or medicine in 2005 for their work. Treatment changed accordingly and now typically consists of antibiotics (such as clarithromycin or amoxicillin) plus metronidazole (Flagyl) and bismuth subsalicylate (e.g., Pepto-Bismol). For the relief of symptoms, drugs such as ranitidine (Zantac), famotidine (Pepcid), cimetidine (Tagamet), and omeprazole (Prilosec) may also be used. Hemorrhage or perforation of peptic ulcers requires emergency medical treatment.
The full set of genes (genome) of H. pylori was determined in 1997. This achievement will help researchers design new drugs to treat and prevent diseases caused by the bacterium.
Concave sore on the skin or lining of an organ, with well-defined, sometimes raised edges. Erosion of surface tissue may extend to deeper layers. The main symptom is pain. The term most often refers to peptic ulcer but also includes skin ulcer, common on legs with varicose veins and the feet of people with diabetes mellitus (when nerve damage has reduced sensation), and decubitus ulcer (bedsore or pressure sore). Other causes include infection, trauma (e.g., burn, frostbite), improper nutrition (e.g., thiamine deficiency), and cancer (likely in ulcers hard to the touch). Skin ulcers over a month old should be checked for cancer, especially after middle age.
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Sore that develops in the mucous membrane of the stomach (more frequent in women) or duodenum (accounting for 80percnt of ulcers and more frequent in men) when its ability to resist acid in gastric juice is reduced. It causes burning ache and hungerlike pain. Ulcers can bleed, perforate the abdominal wall, or block the gastrointestinal tract. Stress and diet were blamed until Helicobacter pylori bacteria and long-term use of aspirin and similar drugs were shown to be the two major causes. The former is treated with combination drug therapy and the latter by stopping the causative drugs if possible or with drugs that reduce acid production. A rare cause is Zollinger-Ellison syndrome, in which a tumour causes increased acid secretion. Cigarette smoking slows healing and promotes recurrence.
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