A Hot New Pain Reliever
While chili peppers are better known for causing pain to diners who eat them unwittingly, they may actually be more useful in pain relief.

Dr. Dottie Brown, assistant professor of surgery at Penn’s Ryan Veterinary Hospital, is working with the National Institutes of Health to test the analgesic properties of resiniferatoxin (RTX), a spicy extract of the Moroccan version of the chili pepper. NIH scientists studying cancer-related pain in humans found that the spinal-nerve cells which carry pain messages to the brain could be killed when filled with calcium—and that those calcium channels could be opened by exposure to RTX.

Brown’s work with cancer-stricken dogs made her a prime research partner because the results from her studies could potentially provide ample data to determine whether or not RTX might work for humans.

Brown compiled a sample of dogs with such severe cancer-related pain that they were unable to walk. After
being injected with RTX, however, the dogs began to run and play. “Owners commented that their dogs slept better at night and were more active and like ‘his or her old self’ during the day,” she says. After treatment with RTX, many dog owners involved in the study “discontinued or greatly reduced the use of supplemental analgesics in their dogs.” Although the majority of these animals have since died from their illness, their last few months of life were much less pain-filled than they would have been without RTX. The study was so successful that Dr. Brown plans to conduct another trial this summer, and NIH is making plans to begin testing the effects of RTX on humans.

A Matter of Trust
African Americans are significantly less likely than white Americans to trust their physicians, according to a study released by the Annenberg School for Communication. Scholars at the school’s Center for Excellence in Cancer Communications Research examined trust in health-care providers, socio-demographics, prior health-care experiences, and the structure of the health-care system, finding that 44 percent of African-Americans reported low trust in their doctors, as opposed to 33 percent of whites.

Distrust was more prevalent among African Americans in the study who received medical care outside of a physician’s office, in a health clinic or emergency room, for example. Among the white participants in the study, those without health insurance or annual health-care visits were most likely to report distrust.

Metamaterials to Marvel Over
An engineering researcher may have discovered a method of making solid objects transparent. Dr. Nader Engheta’s investigations into the largely untapped field of “metamaterials” has yielded promising discoveries, prompting major news organizations to herald the possibility of a Harry Potter-esque “invisibility cloak” in the future.

The H. Nedwill Ramsey Professor of Electrical and Systems Engineering proposes that a metamaterial—a “composite material that can be engineered to exhibit properties … that are unconventional and that may not be readily and easily found in natural materials”—covered in a special “plasmonic” shield will reduce the scattering of light. Because we see objects when light bounces off of them, he explains, “the covered object becomes ‘transparent’ to the observer; in other words, it becomes less detectable.”

Because the frequency of the light beam and the shield need to correspond in order to be effective and the wavelength of light hitting the object must be approximately the same size as the object itself, the prospect of “invisibility cloaks” for large objects like cars or humans is slim. However, Engheta’s research could prove useful for reducing glare, especially from cars or metallic mirrored buildings. In addition, it may one day be used to shield large objects in space, such as satellites, from long wave-length telescopes. Engheta says his research holds promise for a number of different practical applications, not just “cloaking.” He is also studying miniaturized nanocircuits, which could have applications in power-efficient optoelectronics and biotechnology.

—Jennifer Nath C’08

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