In Pixels and in Health: Computer Modeling Pushes the Threshold of Medical Research

By Moreira, Naila | Science News, January 21, 2006 | Go to article overview

In Pixels and in Health: Computer Modeling Pushes the Threshold of Medical Research


Moreira, Naila, Science News


Moment by moment, a movie captures the action as a group of immune cells scrambles to counter an invasion of tuberculosis bacteria. Rushing to the site of infected lung tissue, the cells build a complex sphere of active immune cells, dead immune cells, lung tissue, and trapped bacteria. Remarkably, no lung tissue or bacterium was harmed in the making of this film.

Instead, each immune cell is a computer simulation, programmed to fight virtual tuberculosis bacteria on a square of simulated lung tissue. In their computer-generated environment, these warrior cells spontaneously build a structure similar to the granulomas that medical researchers have noted in human lungs fighting tuberculosis.

The simulation, created by Denise Kirschner of the University of Michigan in Ann Arbor, is an example of an emerging technique called agent-based modeling. This new tool in the world of medical research relies on computing power instead of tissues and test tubes. A growing cadre of researchers, including Kirschner, predicts that agent-based modeling will usher in a broadened understanding of complex interactions within the human body.

The agents in the models are individual players--immune cells in the tuberculosis example. Each player is programmed with rules that govern its behavior. Computer-savvy researchers then set the agents free to cooperate with, compete with, or kill each other. Meanwhile, the agents must navigate the surrounding environment, whose properties can vary over space and time.

Scientists can manipulate disease progression within the models by changing the agents or their environment and then watching what happens. As opposed to traditional, biologically based in vivo or in vitro experiments, these computer trials are dubbed "in silico." The results can suggest biological experiments to test the models' findings and may eventually lead to new medical treatments.

Even simple rules assigned to agents can give rise to surprisingly complex behaviors. When many independent agents interact, they create phenomena--such as the granulomas--that can't necessarily be predicted by breaking down the system into its separate components, says complex-systems specialist John Holland of the University of Michigan.

You've got to study the interactions as well as the parts," Holland says.

In-silico modeling differs from traditional mathematical modeling, which uses differential equations to understand how molecules or cells behave in an averaged, continuous way. Instead, the agents of in-silico modeling make independent decisions in response to situations that they encounter. As a result, unusual activity of even a small number of cells can change the entire system's behavior.

Computers can now calculate thousands of interactions with ease, says Alan Perelson of Los Alamos National Laboratory in New Mexico. "Agent-based modeling has only come into its own with the arrival of really powerful computers sitting on people's desktops, within the last 10 or 15 years," he notes.

Pioneered for economics and population-dynamics studies (SN: 11/23/96, p. 332; www.sciencenews.org/pages/ sn_arc99/4_10_99/mathland.htm), agent-based modeling has only recently plumbed the inner workings of the human body, Perelson adds. That's partly because new imaging and genetic techniques are providing crucial data on which agents' rules can be based.

"Agent-based modeling represents a new frontier with respect to how we do science," says surgeon Gary An of Cook County Hospital in Chicago. "In medicine in particular, all the diseases that we're now dealing with are complex problems: sepsis, cancer, AIDS. All these things are disorders of the system as a whole."

INFLAMMATION SIMULATION An, whom Kirschner calls an in-silico "groundbreaker," got into agent-based modeling to help people survive traumatic injuries and major infections.

A leading cause of death for patients in intensive care units, An explains, is a syndrome called systemic inflammatory response syndrome/multiple organ failure (SIRS/MOF), also termed sepsis when it occurs in response to an infection. …

The rest of this article is only available to active members of Questia

Already a member? Log in now.

Notes for this article

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this article

This article has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this article

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this article

Cited article

Style
Citations are available only to our active members.
Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited article

In Pixels and in Health: Computer Modeling Pushes the Threshold of Medical Research
Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this article

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Help
Full screen

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

    "Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

    1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

    Cited passage

    Thanks for trying Questia!

    Please continue trying out our research tools, but please note, full functionality is available only to our active members.

    Your work will be lost once you leave this Web page.

    Buy instant access to save your work.

    Already a member? Log in now.

    Author Advanced search

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.