Researchers identify substance that protects skin from UV damage. School of Medicine researchers have found that a substance called pTpT enhances a skin cell's natural ability to repair DNA damage from ultraviolet (UV) radiation. According to Dr. Barbara Gilchrest, chair of the department of dermatology and professor of dermatology, "tanning is the body's natural response to UV damage -- it protects the cell's DNA from further UV radiation. Since we knew that pTpT could induce tanning, we reasoned that it might protect against UV light in other ways."

The scientists irradiated both normal and pTpT-treated skin cells with damaging doses of UV light, then measured how well the damage was repaired and how well the cells survived. The "plain" cells exhibited the normal response to UV damage and eventually began to repair the damaged DNA. But the pTpT-treated cells repaired the DNA much faster. "Not only does pTpT induce tanning, but it primes the cell to protect itself by enhancing DNA repair capacity," Gilchrest says.

Gilchrest believes that pTpT may have clinical applications one day. "Tanning lotion containing a pTpT-like substance would not only produce a tan, but might be better able to deal with whatever UV damage it might encounter. With this substance, we could lower the overall risk of skin cancer," she says. Approximately one million people in the United States develop skin cancer every year, and more than 40,000 develop melanoma, the most deadly form of skin cancer.

A leap forward in spinal cord research. Sargent College Assistant Professor of Health Sciences Judith Schotland has received a three-year, $ 240,000 award from the National Science Foundation to investigate the organization of spinal networks.

For several animal species, neuronal circuitry located entirely in the spinal cord is capable of generating highly complex coordinated movement in the absence of input from the brain (if, for example, the spinal cord has been accidentally severed). Schotland seeks to understand the organization of these networks in the generation of movement. "My hope is that studying the organization of movement in the spinal cords of frogs may have applications for spinal cord rehabilitation in humans," she says.

A frog's spinal cord, if severed from the brain, will still exhibit certain motor behaviors, which Schotland divides into two parts: the flex motion and the wipe motion, both of which may be elicited by electrical stimulation. "I hope to determine whether these are controlled by a single network or by multiple networks," she explains. She also hopes to determine the role of neurotransmitters in organizing these networks.

Schotland concedes that the road from intricate knowledge of a single cell in a frog's spinal cord to the cure for human spinal injuries is a long one. "For now, I'm concerned with how motion is coordinated by the spinal cord. My hope is that the understanding I gain of these networks in frogs will ultimately illuminate our understanding of similar networks in people."