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Monday, October 03, 2005

Australians Receive Nobel for Bacterium Work - New York Times

Australians Receive Nobel for Bacterium Work - New York TimesOctober 3, 2005
Australians Receive Nobel for Bacterium Work

Two Australian scientists who discovered a bacterium that causes stomach inflammation, ulcers and cancer won the 2005 Nobel Prize for Physiology or Medicine today.

The winners were Dr. Barry J. Marshall, 54, a gastro-enterologist from Nedlands, and Dr. J. Robin Warren, 68, a pathologist at the Royal Perth Hospital in Perth.

A famous experiment that Dr. Marshall made on himself was crucial in linking the bacterium and inflammation of the stomach, or gastritis.

Their findings in the early 1980's so upset medical dogma, which held that psychological stress caused stomach and duodenal ulcers, that it took many more years for an entrenched medical profession to accept it.

In its citation, the Nobel committee from the Karolinska Institute in Stockholm said that Dr. Marshall and Dr. Warren had "made an irrefutable case that the bacterium Helicobacter pylori" causes the ulcers and other disease.

At the time the Australians were making their findings, doctors could heal ulcers with drugs that blocked the production of gastric acid, but the ulcers often relapsed because the bacteria remained to perpetuate inflammation.

With the Australian finding of the spiral shaped H. pylori bacteria, ulcers are no longer a chronic disease. Doctors can cure most stomach and duodenal ulcers, the stomach irritation (gastritis) that leads to ulcer formation, and many stomach cancers.

"It is now firmly established that H. pylori causes more than 90 percent of duodenal ulcers and up to 80 percent of gastric ulcers," the Nobel committee said.

The inflammation produced by H. pylori can also cause stomach cancer and seems to be prevented by antibiotic treatment of the bacteria. In the early 20th century, stomach cancer was a leading cause of cancer in the United States. But its incidence declined substantially before the discovery of H. pylori's role. Stomach cancer remains the second leading cause of cancer deaths worldwide.

H. pylori also plays an important role in a type of lymphoma cancer of the stomach known as MALT, for mucosa associated lymphoid tissue. Such lymphomas usually regress when antibiotics rid the stomach of H. pylori.

Since the late 1800's, a number of doctors noted the presence of the curved bacteria in the stomachs of patients with ulcers and gastritis, but they ignored the connection.

In the 1980's, Dr. Warren noted the bacteria in the lower part of the stomach in about half the patients from whom biopsies had been taken. He made a crucial observation that signs of inflammation were always present in the surface lining of the stomach near where he observed the bacteria.

Dr. Marshall joined Dr. Warren in studying biopsies from a series of patients and Dr. Marshall succeeded in growing a then unknown bacterium that he thought was a member of the Campylobacter family. It was later renamed H. pylori.

Dr. Marshall has said that he was aided in the discovery by working in an academically obscure location where he could keep an open mind on pursuing his observations.

"If I had come up through the normal gastro-enterology training schemes in the United States, I would have been so indoctrinated on the acid theory that I wouldn't have been considering anything else and might have skipped over Helicobacter, as everyone else had done," Dr. Marshall said in a telephone interview today. "Robin is quite obsessional. Once he sees something, he's determined to see what itis. He would have found another Barry Marshall" to make the discovery.

In the wake of the ulcer discovery, many scientists are seeking unknown infectious agents as the cause of many chronic diseases. Examples are microbes that might produce atherosclerosis, the underlying basis of coronary artery disease, and other chronic ailments like ulcerative colitis, regional enteritis, also known as Crohn's disease), and rheumatoid arthritis.

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