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Spotlights on Hot Science

These stories describe NIGMS-funded medical research projects. Although only the lead scientists are named, they work together in teams to do this research.

How Bacterial Slime Clogs the Works

This image from a time-lapse movie shows biofilm growth and streamer formation over
a period of about 56 hours. Courtesy: Knut Drescher, Princeton University

This image from a time-lapse movie shows biofilm growth and streamer formation over a period of about 56 hours. Courtesy: Knut Drescher, Princeton University

Given a suitable surface, water and nutrients, bacteria will likely put down stakes and form communities called biofilms. These sticky, slimy microbial metropolises wreak havoc when they clog implanted medical devices like stents and catheters.

Researchers at Princeton University (including Bonnie Bassler; see "Bugging the Bugs" in the October 2004 issue of Findings) discovered how biofilms block such tubular devices. They created a time-lapse movie of the process (see by recording fluorescently labeled bacteria through a microscope.

The scientists concluded that, after forming a layer on the inside of the tube (green), bacteria grow sticky streamers (red). The streamers tangle into a sievelike mesh that traps passing bacteria and debris, quickly blocking the tube completely. The researchers suspect that streamers are also the root cause of biofilms in industrial water filters, sewage facilities and natural settings like rivers and soil. If they could stop streamers from forming, scientists might be able to slow or even prevent bacterial clogging in medical and industrial settings.
—Elia Ben-Ari

Mysterious Rare Blood Type Explained

Blood cells. Courtesy: Stock image

Researchers discover the molecular basis of a rare blood type, Vel-negative.

What's your blood type: A, B, AB or O? Rh positive or negative? In addition to these familiar blood groups, there are more than 30 others, with names like Colton, Kidd, Diego and Duffy. Each defines a specific molecular variation on the surface of red blood cells. New blood types are usually discovered in—and named after—someone whose body launches a life-threatening immune attack against donated blood.

One rare blood type, Vel-negative, was first noticed in 1952, but its molecular basis remained mysterious until this year. Bryan Ballif of the University of Vermont, along with scientists in France, discovered that people with Vel-negative blood have a genetic variation that results in the absence of a tiny, previously unknown protein called SMIM1 on their red blood cells.

About 1 in 2,500 people in North America and Europe are Vel-negative. If these people need blood transfusions, they may require Vel-negative blood to avoid potentially fatal complications. The scientists developed two genetic tests that will quickly detect Velnegative blood, so those who have it can be cared for properly.
—Alisa Zapp Machalek

Other Spotlights

Geckos use nanoscale structures on their feet to accomplish gravity-defying feats like hanging upside down from polished glass. Courtesy: Kellar Autumn, Lewis & Clark College.How Porcupines and Geckos Inspire Medical Materials
Nature's designs are giving researchers ideas for new technologies that could help wounds heal, make injections less painful and provide new materials for a variety of purposes.

Watching zebrafish embryos grow allows scientists to understand how our blood vessels develop and how their closed structure evolved. Courtesy: National Center for Microscopy and Imaging Research.Learning About Human Biology From a Fish
The zebrafish offers important insights into our own biology.

Mitochondria. Courtesy: Judith StofferMitochondrial Mix-Up
Energy-producing mitochondria are vital to human survival. Researchers explore how genetics play a key role in proper mitochondrial function.

A powerful light microscope captures this scene from the process of mitosis. Courtesy: Jane Stout, research associate in the laboratory of Claire Walczak, Indiana University. Spotlighting the Ballet of Mitosis
A powerful light microscope captured this scene from mitosis, revealing details that could lead to a better understanding of how errors in cell division occur.

This page last reviewed on October 24, 2013