If they had done it on anyone else, it probably would have violated the Helsinki convention.

Barry Marshall, of the University of Western Australia's Helicobacter pylori Research Laboratory in Nedlands, Australia, and Robin Warren, a pathologist retired from the Perth Royal hospital in Australia, received the 2005 Nobel Prize in physiology or medicine for their discovery of "the bacterium Helicobacter pylori and its role in gastritis and peptic ulcer disease."

Prior to Marshall and Warren's work, gastric ulcers were thought to be caused by excess stomach acid production brought on by stress. Warren and Marshall noticed, however, that bacteria, later named H. pylori, were present in biopsies from patients with ulcers, and that those bacteria seemed to cause inflammation in patients with ulcers.

Convincing others was a different matter. In an interview posted to the Nobel website, Warren said that even after he had observed the bacteria, "it took a long time to convince everybody that they were there. It took about 15years before it started appearing in the textbooks."

The reason for this recalcitrance was that Marshall and Warren were going up against a century of medical dogma.

"Medicine, before I saw [the bacteria], was going by the standard methods of teaching," Warren said. "When you swallowed bacteria, it was sterilized in the stomach, so it didn't get through the intestines. Nothing grew in the stomach. And that was something that has been taught to the students for a hundred years."

That wasn't the case, and to convince their skeptical peers, Warren and Marshall took a time-honored approach in medical science: They experimented on themselves.

In the early 20th century, physician Joseph Goldberger took a similar approach to prove that another disease, pellagra, was not, in fact, infectious. He and his assistant self-administered various bodily substances from pellagrics in so-called "filth parties" to show that they would not contract pellagra (which was later shown to be caused by niacin deficiency).

In the case of H. pylori, the same approach led to the opposite conclusion: Marshall swallowed a dose of H. pylori, which promptly gave him a bad case of gastritis that was then cured by antibiotics. Though Marshall did not let his condition progress to a stomach ulcer, the experiment cemented the link between infection and stomach inflammation.

Asked whether the disbelief of the medical community was frustrating, Marshall was philosophical: "You know, I didn't really mind all that much; it was a bit annoying. But I kept on with my work because I knew I was right, because I'd seen them there, you see?"

Chemistry: The Grass Is Greener With Metathesis

To the general public, "organic" connotes green; in that sense, the 2005 Nobel Prize for Chemistry was given for organic chemistry in several ways.

At a press conference, Richard Schrock, professor of chemistry at the Massachusetts Institute of Technology in Cambridge, seemed a bit doubtful: "I've seen the word in some press releases," he told reporters.

Schrock shares the 2005 chemistry prize with two other researchers: Yves Chauvin at the Institut Français du Pétrole, Rueil-Malmaison, France, and Robert Grubbs at the California Institute of Technology in Pasadena. The scientists were honored "for the development of the metathesis method in organic synthesis."

The catalysts Schrock has developed are highly reactive and necessitate the use of solvents few people would consider ecologically sound, though his colleague Robert Grubbs has developed water-stable catalysts that can manipulate carbon double bonds into metathesis reactions. But they do have ecological advantages because they make the process of generating compounds more efficient: "Instead of doing something in 10 or 15 steps, [with metathesis] you can do it in five steps, so you save a lot of manipulation, a lot of waste, a lot of solvent," Schrock said. "In that sense, yes, it is green."

Metathesis is a form of synthesis in which two compounds swap parts of their structures; it enables the design of custom-built molecules and has what the Nobel committee termed an "astonishing" range of applications.

Chauvin determined the basic mechanism of metathesis, while Grubbs and Schrock each developed catalysts that enabled a wealth of metathesis reactions involving double and triple bonds between carbon atoms.

"Basic research these days doesn't have a lot of cachet to it," he said. "But basic research is still very, very important, and it's not recognized as much today as it should be. People are turning to applications. But what I did, what Bob Grubbs did, had applications. It's just we didn't know it at the time. But we had faith that we were doing something new and that applications would develop, and they have."

Such applications include pharmaceuticals synthesis. Schrock said that "drugs are made today using these reactions. Now they may not be at the level yet where someone would buy it in a pharmacy - that takes some time before it's approved and so on. But many people are interested in making pharmaceuticals, drugs in particular, this way."

In an interview posted to the Nobel website, Grubbs said of the Nobel Prize that "it's one of the things no one ever expects to happen." His 2005 Nobel colleagues in medicine were less bashful. Although they claimed that it was "more of a joke," a cheerful Marshall told the Nobel foundation interviewer that for several years, he and Robin Warren have gotten together for a beer the day the medicine Nobel is announced, waiting for the call from Stockholm.