Biomedical Beat - A monthly digest of research news from NIGMS

February 20, 2007

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The National Institute of General Medical Sciences (NIGMS), one of the National Institutes of Health, supports all research featured in this digest. Although only the lead scientists are named, coworkers and other collaborators also contributed to the findings. To read additional news items, visit NIGMS News. To check out other free NIGMS publications, go to the order form.

Cool Image: Motion in the Brain

Motion in the Brain
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Amid a network of blood vessels and star-shaped support cells, neurons in the brain signal each other. The mists of color show the flow of important molecules like glucose and oxygen. This image is a snapshot from a 52-second simulation created by animation artist Kim Hager at the University of California, Los Angeles. Such visualizations make biological processes more accessible and easier to understand. Courtesy of Hager and neurobiologist Neal Prakash, UCLA.

Watch the full animation (no longer available)
UCLA Laboratory of Neuro Imaging

The Zoo on Human Skin

Would you believe that bacteria living in our bodies outnumber our cells 10 to 1? It's true, and scientists are trying to understand how these microbial inhabitants may affect human health. Toward this goal, microbiologist Martin Blaser of New York University took a bacterial inventory of skin. After swabbing the forearms of six healthy volunteers, he and colleagues used DNA technology to identify the bacterial populations. The researchers were surprised to find that 71 percent of the bacterial species were unique to each individual, and that 8 percent of the species had never before been described. Blaser's next step is to examine differences in the bacterial populations of diseased and healthy skin.

Full story
Blaser lab home page
Article abstract (from the February 9, 2007, issue of PNAS)

Test Detects Drug-Resistant HIV Strains

HIV type 1 genomes with (green) and without (red) a specific mutation associated with drug resistance. Courtesy of Gao.
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HIV type 1 genomes with (green) and without (red) a specific mutation associated with drug resistance. Courtesy of Gao.

A major barrier to treating HIV/AIDS is the virus' ability to rapidly develop drug resistance. A team led by virologist Feng Gao of the Duke University Medical Center has developed a highly sensitive test that can identify drug-resistant HIV strains in a patient's bloodstream. The test relies on fluorescently labeled molecules to tag the locations of mutated genes known to help the virus evade antiretroviral therapies. In studies, the test could detect a single mutated virus out of 10,000 unchanged ones. Knowing the drug-resistant strains in individuals infected with HIV could help predict the outcomes of treatment with existing drugs and aid in the development of new, more effective medicines.

This work was also supported by NIH's National Institute of Allergy and Infectious Diseases.

Full story (no longer available)
Gao lab home page
Article abstract (from the February 2007 issue of Nature Methods)

Sea Squirt Toxin Could Yield New Anti-Cancer Drug

A poisonous sea squirt may lead to new medicines to treat many types of cancer. A research team led by Patrick Harran, a chemist at the University of Texas Southwestern Medical Center, has shown that a synthetic version of a toxin produced by the donut-shaped creature can shrink human tumors implanted in mice. Equally significant, the substance doesn't cause some of the serious side effects associated with existing cancer drugs. The team found that, while the toxin blocks cell division just like many chemotherapy drugs do, it works in a different way. More experiments may lead not only to new therapeutic approaches, but also to new discoveries about cell division, a process crucial to all life.

Full story
Harran home page (no longer available)
Article abstracts 1, 2 (published online February 7, 2007, in PNAS)

Protein Could Aid Spread of Prion Diseases

Prion protein clusters (green) in a yeast cell. Courtesy of Serio.
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Prion protein clusters (green) in a yeast cell. Courtesy of Serio.

Mad cow and Creutzfeldt-Jacob diseases are the deadly result of prions, self-replicating proteins that cluster inside cells. Scientists have speculated that such prion diseases spread within the body when prion clusters break apart, but how this may actually happen has been unclear. Now, molecular biologist Tricia Serio at Brown University has discovered that a protein called Hsp104 plays a critical role in fragmenting prion clusters. The research was done in yeast, which has a protein similar to the human prion protein. Serio's finding suggests that it might be possible to slow the progression of prion diseases by developing a drug to block Hsp104 activity.

Full story
Serio home page
Article abstract (from the February 2007 issue of PLoS Biology)