Comments on: Does H. Pylori Cause Stomach Ulcers?

by: Seth’s blog » Blog Archive » Modern Biology = Cargo-Cult Science?

Thu, 08 Oct 2009 08:37:04 +0000

[…] Shameless. Note the utter absence of even one disease in one person cured or prevented. Not one. And this is supposed to be the most beneficial discovery in medicine. It’s the top prize in medicine and biology! Last year the prize was given for HIV. Do we have an HIV vaccine? No. The year before that, HPV. Do we have an HPV vaccine? No. A few years before that, the discovery that a certain bug “causes” stomach ulcers — the award that showed that the medical community and the Nobel Prize committee have a weak grasp of the concept of causality. The biologists think they do everything right — but the planes don’t land. The biologists who do this research aren’t able to solve actual problems. (Some people do — those who discovered that smoking causes cancer, for example — but they don’t get Nobel Prizes.) Could something important be missing from their view of the world? I think so. […]

by: Sean

Sun, 13 Sep 2009 16:49:27 +0000

I think the word interaction may apply here.

by: seth

Sun, 13 Sep 2009 06:19:05 +0000

So what if smoking one cigarette per month doesn’t cause lung cancer? I fail to see the relevance.

by: anonymous

Sun, 13 Sep 2009 03:55:46 +0000

smoking doe not always result in lung cancer, therefore it can’t “cause” it?

by: seth

Sat, 12 Sep 2009 23:34:58 +0000

“It hardly seems necessary for him to proceed all the way to developing an ulcer for the sake of the experiment.” That’s where I disagree. His theory was about ulcers, not gastritis. If you can show me evidence that gastritis always leads to ulcers, I’ll revise my opinion.

by: Jeff

Sat, 12 Sep 2009 18:44:11 +0000

Seth,
This sentence borders on the misleading, hopefully not intentionally so.

“Marshall famously drank a flask full of H. pylori and didn’t get an ulcer, yet took this to support his theory.”

Marshall had gastritis after drinking the H. pylori. And gastritis can lead to ulcers. It hardly seems necessary for him to proceed all the way to developing an ulcer for the sake of that experiment. You can disagree with the current paradigm about H. pylori and ulcers and still acknowledge Marshall’s experiment accurately.

Jeff

p.s. I’m not a doctor but the gastritis -> ulcer relationship seems to be mentioned at reputable websites.

by: seth

Fri, 11 Sep 2009 23:54:03 +0000

These comments about “necessary but not sufficient” and Koch’s postulates suggest to me that Warren and Marshall’s confusing use of “causes” (in “H. pylori causes ulcers”) has been a distraction — the question most helpful to answer is why a few people infected with H. pylori get ulcers yet almost all of them don’t. As far as I can tell, Koch’s postulates and studies of phagocyctes don’t help us figure that out.

by: Ronald Mignery

Fri, 11 Sep 2009 16:54:53 +0000

For H. pylori to cause ulcers, recent research suggests that is must first set up residence in the vacuoles of phagocyctes: http://www.eurekalert.org/pub_releases/2009-01/sfeb-hpc012709.php. The presence of H. pylori in the stomach is then a necessary but not a sufficient cause of ulcers. Clearing H. pylori from the vacuoles of phagocytes could then cure the disease even without clearing it from the stomach.

by: Les Jones

Fri, 11 Sep 2009 14:48:37 +0000

“Marshall famously drank a flask full of H. pylori and didn’t get an ulcer, yet took this to support his theory.”

This simply shows that the presence of H. pylori is necessary, but not sufficient, to cause the ulcer. That seems to be true of most germs. We’re all of us exposed to all kinds of disease-related germs every day, but don’t necessarily contract every disease to which we’re exposed.

Review Koch’s postulates of the germ theory of disease:

http://en.wikipedia.org/wiki/Koch%27s_Postulates

Koch’s postulates are:

1. The microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy animals.
2. The microorganism must be isolated from a diseased organism and grown in pure culture.
3. The cultured microorganism should cause disease when introduced into a healthy organism.
4. The microorganism must be reisolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent.

However, Koch abandoned the universalist requirement of the first postulate altogether when he discovered asymptomatic carriers of cholera[1] and, later, of typhoid fever. Asymptomatic or subclinical infection carriers are now known to be a common feature of many infectious diseases, especially viruses such as polio, herpes simplex, HIV and hepatitis C. As a specific example, all doctors and virologists agree that poliovirus causes paralysis in just a few infected subjects, and the success of the polio vaccine in preventing disease supports the conviction that the poliovirus is the causative agent.

The third postulate specifies “should”, not “must”, because as Koch himself proved in regard to both tuberculosis and cholera,[2] not all organisms exposed to an infectious agent will acquire the infection. Noninfection may be due to: chance or to the host’s immune system successfully repulsing the invading pathogen; acquired immunity, as from previous exposure or vaccination; or genetic immunity, as with the resistance to malaria conferred by possessing at least one sickle cell allele.

The second postulate may also be suspended for certain microorganisms which we cannot (at the present time) grow in pure culture, such as some viruses. In summary, a body of evidence that satisfies Koch’s postulates is sufficient but not necessary to establish causation.

by: Alex C.

Fri, 11 Sep 2009 13:37:08 +0000

And speaking of inappropriate Nobel prizes, let’s not forget that Portuguese neurologist António Caetano de Abreu Freire Egas Moniz won the Nobel Prize for physiology or medicine in 1949. What was his contribution to society? Well, he invented and popularized the pre-frontal leucotomy, a variation of lobotomy. For more information, see this excellent book called “Great and Desperate Cures: The Rise and Decline of Psychosurgery and Other Radical Treatments for Mental Illness”, by Elliot Valenstein:

http://www.amazon.com/Great-Desperate-Cures-Psychosurgery-Treatments/dp/0465027113/

There is also a movement (unsuccessful, so far) to strip Egas Moniz of his prize:

http://www.psychosurgery.org/news-opinion/why-nobel-should-rescind-the-prize/