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Week of Oct. 8, 2005; Vol. 168, No. 15 , p. 229
Nobel prizes: The power of original thinking
Awards honor a gutsy move, optical brilliance, and chemical crossovers
Nathan Seppa, Peter Weiss, and Aimee Cunningham
Two Australian scientists who showed that bacteria can cause stomach
ulcers have won the 2005 Nobel Prize for Physiology or Medicine.
The
researchers made their discovery 23 years ago, at a time when ulcers
were thought to result mainly from excess stomach acid brought on
by stress and spicy food. In 1979, J. Robin Warren, a pathologist
at the Royal Perth Hospital, noticed a curved bacterium in stomach-tissue
samples from a patient. A few years later, a gastroenterologist
at the hospital, Barry J. Marshall, cultured the microbe—ultimately
named Helicobacter pylori. The two scientists then found H. pylori
in nearly all patients with ulcers and also in most patients with
gastritis, an inflammation of the stomach lining.
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TOUGH
CUSTOMER. Scientists had thought that no microbe could live
in the acidic stomach, but Helicobacter pylori proved them
wrong.
Nobel Committee for Physiology or Medicine
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Despite
the duo's string of confirming reports in the 1980s, the scientific
community demurred for a decade before adopting the notion that
a pathogen could cause stomach ulcers. Today, gastroenterologists
estimate that H. pylori causes 80 to 90 percent of ulcers. Antibiotics
plus acid-blocking drugs routinely cure the disease.
"The
award is well deserved," says Martin J. Blaser, an infectious-disease
physician at New York University School of Medicine. Over the past
decade, treatment has made H. pylori "an endangered species
in the stomach," he says.
However,
Blaser recalls a 1983 scientific meeting in Brussels at which Marshall
presented his early findings. "Marshall said they had discovered
a new bacterium," says Blaser. "That data looked good."
But when Marshall claimed that the microbe was the cause of stomach
ulcers, "people were skeptical, because quack theories arise
all the time," Blaser adds.
The
following year, a frustrated Marshall took an extreme step: He swilled
a vial of live H. pylori. Within a week, he developed raging gastritis.
Treatment with an antibiotic and bismuth, which had shown some efficacy
against ulcers, eradicated the microbe. But Marshall's stunt still
didn't appease all his critics.
Finally,
large-scale trials in the early 1990s established that antibiotics
coupled with acid-blocking drugs or bismuth indeed knock out the
microbe and cure ulcers.
Warren
has since retired, and Marshall is now at the University of Western
Australia in Nedlands. They will share the $1.3 million award.
The
discovery of H. pylori "represents a paradigm shift" in
the study of human diseases, says gastroenterologist Richard M.
Peek Jr. of Vanderbilt University School of Medicine in Nashville.
With their work, Peek says, Warren and Marshall showed that H. pylori
infections can lead to dangerous inflammation. Other researchers
have since linked inflammation of various origins to malignancies.
For
example, they've tied chronic inflammation in the intestines to
colon cancer and linked inflammatory infections by hepatitis B and
C viruses to liver cancer. In some cases, H. pylori infection itself
can predispose a person to stomach cancer, Peek notes.
H.
pylori infects half the world's population, but only a fraction
of those people get ulcers. Scientists are now examining genetic
variations in people that might explain why only some are vulnerable
to the microbe.
—N.
Seppa
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