Transcript of the Interview with Dr. John Younger on how Medicine, Math and Engineering Combine to Reveal how Sepsis and Less Severe Infections Occur
November 11, 2008
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It's a leading cause of death but no one knows for sure how and why it happens. It's a major source of healthcare costs, adding days or weeks to the hospital stays and lost work time for millions of people. But no one fully understands how best to fight it. "It" is a bacterial infection of the blood also called bacteremia. It's a major part of the very serious illness called sepsis. Hospitals struggle mightily but often futilely to prevent and treat it every day. Now new research by a University of Michigan team and their colleagues is tackling the problem at its most basic level. Their hope is to find new and more effective ways to treat bacteremia and sepsis. Dr. John Younger, an associate professor of emergency medicine at the U of M Medical School, explains.
"We think that by understanding the physical concepts of what's required for the body to get the bacteria out of the blood stream, if we can understand those features, there are some relatively simple things you can do to change the rules mechanically for the bacterium of the blood stream and you may be able to do some things that the bacteria will not be able to develop resistance against but which will manage to filter out the blood stream more effectively. "
In a research paper published in the November issue of the journal Shock and recent papers in the journals Bulletin of Mathematical Biology and Academic Emergency Medicine the team describes new computer-based models of blood stream infection that may help guide the development of new treatments. The new findings give more information than ever before about how bacteria act within the blood vessels of the body and how they might be filtered out of the blood and into the organs where the immune system can attack and kill them. According to Younger:
"The work that we've been doing so far has revealed a couple of interesting features. The first is that with a little bit of time, a little bit of patience, a little bit of computing power you actually can start to write down some of the physical rules about how bacteria that begin in the blood stream distribute into other places in the body. You can identify where in the body that filtration will happen, where the best line of defense is, based on some fairly simple mathematical rules. That's one thing that we've been interested in that we've discovered with the work so far.
The other thing that we've discovered is that bacteria in the blood stream probably travel in packs."
Antibiotic drugs have been the standard treatment for these conditions since the drugs were developed in the mid-twentieth century. But because common bacteria have evolved to evade these drugs antibiotics are becoming less and less effective against blood stream infections. Younger tells us:
"And so what we're looking for are ways of treating the disease and helping along the host defenses in such a way that doesn't require antibiotics. And one of the ways that we're looking to do that is we're looking to find a strategy to improve the ability of the blood stream to filter these things out, how can they come out of the blood stream even faster, the mechanical tricks that you can play on the bacterium that don't require antibiotics, that allow the body to grab and plough the blood stream and resolve the infection faster. "
Younger and his team have more research to do before the models yield results that might affect human treatment. But already they are seeing potential for how to improve the models and use them to simulate different aspects of human bacteremia and sepsis. Andy McDonald, U of M Health System news.
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