From the Labs: Biomedicine
New publications, experiments and breakthroughs in biomedicine–and what they mean.
Fighting the Flu
Newly made antibodies protect against multiple varieties of flu.
Source: “Structural and Functional Bases for Broad-Spectrum Neutralization of Avian and Human Influenza A Viruses”
Jianhua Sui et al.
Nature Structural and Molecular Biology 16: 265-273
Results: Scientists have developed antibody proteins that can neutralize multiple strains of the influenza virus, including common seasonal strains, the deadly H5N1 bird flu, and the virus behind the 1918 epidemic.
Why it matters: Most flu vaccines are effective against only a specific strain of flu; they must be reformulated every year, because they target a part of the virus that constantly mutates to produce new seasonal strains. But the new antibodies target a part of the virus that is common to different strains, so they appear to be broadly effective.
Methods: Scientists first screened billions of antibodies and found a small group that protected against different types of bird flu. Three of these had broad neutralizing abilities when tested in cells and in mice. By looking at the structure of the successful antibodies and analyzing the way they bind to viruses, the scientists identified a part of a protein on the virus’s surface that is shared by different strains of influenza.
Next steps: Researchers will test the antibodies in ferrets, the “gold standard” animal model for influenza, and then develop clinical-grade versions for human testing.
Brain imaging can reveal what a person is thinking.
Source: “Decoding Reveals the Contents of Visual Working Memory in Early Visual Areas”
Stephenie A. Harrison and Frank Tong
Nature 458: 632-635
Results: By analyzing data collected with functional magnetic resonance imaging (fMRI), researchers identified with 83 percent accuracy which of two images a person was remembering.
Why it matters: Previous research has shown that fMRI can reveal which of a number of pictures a person is looking at. But the new study is unique in identifying what the subject viewed before the brain imaging took place. The study also sheds light on where in the brain visual working memories are stored.
Methods: Subjects were briefly shown two successive images of a grating oriented at different angles. They were asked to remember one of the images as an fMRI scanner monitored blood flow in the brain, a proxy for brain activity. Scientists then used specially designed algorithms–derived from previous brain scans of each person–to search for activity patterns that indicated which image the person was thinking of, several seconds after the image itself had disappeared.
Next steps: The researchers are now testing the technique with more-complex visual patterns and exploring ways of using it to gather more information about what people are actively remembering.