Prehistoric Origins Of Stomach Ulcers Uncovered

Science Daily ^ | 2-8-2007 | BBSRC

[blam]

Source: Biotechnology and Biological Sciences Research Council
Date: February 8, 2007

Prehistoric Origins Of Stomach Ulcers Uncovered

Science Daily — An international team of scientists has discovered that the ubiquitous bacteria that causes most painful stomach ulcers has been present in the human digestive system since modern man migrated from Africa over 60,000 years ago. The research, published online (7 February) by the journal Nature, not only furthers our understanding of a disease causing bacteria but also offers a new way to study the migration and diversification of early humans.

A cell of H.pylori, a bacterial pathogen of the human stomach. The curved shape of the cell, and its bundle of flagella which enable it to wriggle through mucus covering the cells lining the stomach, can be seen clearly. (Image Credit: Dr. Charles Penn, University of Birmingham)

The international research collaboration was led by scientists from the University of Cambridge, the Max Planck Institute in Berlin, and the Hanover Medical School. The researchers compared DNA sequence patterns of humans and the Helicobacter pylori bacteria now known to cause most stomach ulcers. They found that the genetic differences between human populations that arose as they dispersed from Eastern Africa over thousands of years are mirrored in H. pylori.

Human DNA analysis has shown that along the major land routes out of Africa human populations become genetically isolated - the further from Eastern Africa a population is the more different genetically it is compared to other human populations. Other research has shown gradual differences in European populations, presumed to be the result of Neolithic farmers moving northwards. The international H. pylori research team found almost exactly the same genetic distribution patterns in their results.

The scientists combined their genetic analysis with a computer simulation the modelled the spread of the bacteria across the globe. This showed that it migrated from Eastern Africa at almost exactly the same time as early humans, approximately 60,000 years ago.

The UK research effort was led by Dr Francois Balloux, a Biotechnology and Biological Sciences Research Council-funded scientist at the University of Cambridge. He said: "Humans and this ulcer-causing bacterium have been intimately linked for the last 60,000 years. The research not only shows the likelihood that for tens of thousands of years our ancestors have been suffering the effects of this bacteria but it also opens up new possibilities for understanding early human migration. By showing that Helicobacter pylori emerged from Africa at the same time as early humans it makes it easier to examine some of the controversial questions about human migration. For example we could use our understanding of the bacteria's spread to gauge poorly understood human population shifts in Europe, Africa and Asia."

Notes

The paper, 'An African origin for the intimate association between humans and Helicobacter pylori', is published by Nature Advance Online Publication at 1800 Wednesday 7 February 2007. The digital object identifier for citations is 10.1038/nature05562

Helicobacter pylori is a bacterium that infects the mucus lining of the stomach and duodenum.

Helicobacter bacteria are the only known microorganisms that can thrive in the highly acidic environment of the stomach. Its helical shape is thought to have evolved to penetrate and colonize the mucus lining.

Most cases of peptic ulcers and gastritis are caused by H. pylori, not spicy food and stress and spicy food as many thought until the 1990s. These conditions are now widely treated with antibiotics effective against the bacteria.

The international research collaboration was funded by the German Federal Ministry for Education and Research, the Biotechnology and Biological Sciences Research Council, the Swedish Research Council and Lund University Hospital.

[wildbill]

Ulcers came into being just about the time wives did"

It was when the women came up with the perfect response:

"Not tonight, Ugahh, you gave me a headache with that club."

This shifted control from the club to the...

[IronJack]

And we've been paying for the ... ever since.

[Grizzled Bear]

not spicy food and stress and spicy food

__________________________________________________________

I guess Science Daily thought it needed repeating.

[AdmSmith]

Talking about pre-historic infections.

Retroviruses are viruses that reverse-transcribe their RNA into DNA for integration into the host's genome (see this http://www.maxanim.com/microbiology/Replication%20Cycle%20of%20a%20Retrovirus/Replication%20Cycle%20of%20a%20Retrovirus.htm for an animation)

Most retroviruses (such as HIV-1) infect somatic cells, but some can also infect germline cells and once they have done so and have been transmitted to the next generation, they are termed endogenous. Endogenous retroviruses can persist in the genome of their host for long periods. However, they are generally only infectious for a short time after integration as they acquire 'knockout' mutations during host DNA replication.

The published human genome sequence contains many thousands of endogenous retroviruses (HERVs) but all are defective, containing nonsense mutations or major deletions. Only the HERV-K(HML2) family has been active since the divergence of humans and chimpanzees; it contains many members that are human specific. This article http://jvi.asm.org/cgi/content/full/79/19/12507 indicates that the HERV-K(HML2) family may be active in present-day humans. The possibility that the family is active today is particularly important because it has been implicated in a range of human diseases.

[SteveH]

Helidac isn't that bad...

[SteveH]

But, of course, he was right.

Barry Marshall and Robin Warren

2005 Nobel Prize [Physiology]

href=http://nobelprize.org/nobel_prizes/medicine/laureates/2005/press.html

[albee]

Your post #9 is HYSTERICAL!!!

[SunkenCiv]

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