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

Breaking Up Biofilms Is Hard to Do

Close-up of a biofilm beginning to disperse. Courtesy: Cecile Berne, Indiana University

Close-up of a biofilm beginning to disperse. Courtesy: Cecile Berne, Indiana University

Long before people started living in villages, bacteria figured out the advantages of community. When possible, most bacteria live together in what are known as biofilms. Like it did for early human populations, communal living protects bacteria from the hazards of the world—including antibiotics.

Biofilms form a tenacious slime that adheres to almost anything that tends to stay moist—hospital tubing, teeth, kitchen drains and oil pipelines. Although often harmless to humans, biofilms are responsible for many infections, including of the ear and urinary tract.

Now, researchers Jon Clardy, Roberto Kolter and Richard Losick at Harvard University in Cambridge, Massachusetts, think they have found a way to break up biofilms. The scientists are co-opting biochemical signals that biofilms use to disperse and spread to new locations when they run out of food or pile up too much waste. The signals are chemically simple and appear to act on a wide variety of bacterial species. If the substances can dissolve or prevent biofilms in real-world situations, their use could lead to advances in medicine, industry and even household cleaning products. —Karin Jegalian

Cells for Sight

Studies in mice could help scientists treat vision problems in humans.

Studies in mice could help scientists treat vision problems in humans.

When it comes to cells involved in vision, rods and cones are considered top players. Together, these cells collect multicolored rays of light that the brain uses to create images of the vibrant world around us.

But biologists have now discovered that other, less well known eye cells also help with vision. A team led by Samer Hattar of Johns Hopkins University in Baltimore, Maryland, found that mice without rods and cones are not totally blind: They can exit a maze by recognizing a particular visual pattern.

How do mice that lack rods and cones see this—or any—pattern? According to Hattar's study, the mice use a type of cell called intrinsically photosensitive retinal ganglion cells (ipRGCs).

Scientists already knew that ipRGCs shrink pupils in bright light and influence waking and sleeping cycles, but they didn't realize that the cells also play a role in forming images.

Hattar's team found several kinds of ipRGCs, some of which project into a part of the brain involved in image perception. The unexpected discovery of ipRGCs' new role could lead to new approaches for treating vision problems. —Kirstie Saltsman

Seeking the Causes of Sepsis

Sepsis is usually treated in a hospital intensive care unit, where IV antibiotics and fluids help fight infection and keep blood pressure from dropping too low.

Sepsis is usually treated in a hospital intensive care unit, where IV antibiotics and fluids help fight infection and keep blood pressure from dropping too low.

If you read about Kevin Tracey in the September 2010 issue of Findings, you know that sepsis, or body-wide inflammation, is a top killer that remains difficult to understand and treat.

Tracey discovered that the nervous system is involved in this immune response and that stimulating a particular nerve could protect animals—and possibly humans—against sepsis.

Other scientists are looking elsewhere.

Trauma surgeon Carl Hauser at Beth Israel Deaconess Medical Center in Boston focuses on mitochondria. These cellular power plants can spill into the bloodstream after an injury. Because they're biologically similar to bacteria, mitochondria can ignite a sepsislike immune response.

At the Oklahoma Medical Research Foundation in Oklahoma City, cardiovascular biologist Charles Esmon points to histones, the spoollike structures that wind DNA into tidy shapes. Esmon found that histones can enter the bloodstream during an infection and cause sepsis. He also discovered that Xigris®, a drug used to treat sepsis, works by chopping up histones.

Because histones are also linked to multiple sclerosis, lupus and other diseases, finding ways to inactivate them could have benefits beyond fighting sepsis. —Emily Carlson

Sun Damage—More Than Skin Deep

Research on an enzyme that repairs sun damage in plants and animals could reveal new ways to prevent and treat skin cancer
in humans.

Research on an enzyme that repairs sun damage in plants and animals could reveal new ways to prevent and treat skin cancer in humans.

Too much sun makes your skin wrinkled, burned and leathery. It also damages your DNA, increasing your risk for cancer. Plants and many animals have an enzyme called photolyase that can repair sun damage. Humans lack it.

Recent studies revealing the workings of photolyase provide a ray of hope for preventing or treating sun damage in people. The research was led by Dongping Zhong, a physicist and chemist at Ohio State University in Columbus.

The scientists first exposed a strand of DNA to ultraviolet (UV) light, causing the same kind of damage as the sun. Then they added photolyase. Using an ultrafast laser as a sort of high-tech flashbulb, they were able to see photolyase in action as it repaired the UV-damaged DNA.

Zhong's group discovered that photolyase sends an electron and a proton to repair the damaged genetic material. After this process, the electron and proton return to the enzyme—possibly to start over and heal other areas.

More research on photolyase might lead to new treatments for skin cancer and better sunscreen products. —Jilliene Mitchell

This page last reviewed on May 18, 2011