October 21, 2009

Research Without Borders

On tap with 83 other projects at one-day event: radically new antibiotic delivery, tracking tuberculosis in Nepal and the effectiveness of anti-obesity campaigns

By Jacqueline Mitchell

From Grafton to Nepal to outer space, Tufts researchers know no boundaries. At this year’s Research Day, held October 5 on the Boston campus, Tufts investigators from diverse fields convened to present their work on the common theme of global health and infectious disease.

Captive Asian elephants such as this one are regularly used in the tourist industry in Nepal, but they may be a source of tuberculosis, researchers say. Photo: iStock

Throughout the day, 22 of the university’s top researchers served as speakers for discussions about food, water, prevention and vaccines and emerging infectious diseases. Gerald T. Keusch, associate provost for global health at Boston University and associate dean of the BU School of Public Health, gave the keynote address on the future of global health.

The seventh in the series, Research Day is hosted by the Office of the Vice Provost and is intended to showcase the groundbreaking work under way at Tufts and its affiliates and to enhance cross-disciplinary and cross-campus collaboration. Here is a small sampling of the 86 projects featured at this year’s Research Day.

A Better Way to Dispense Antibiotics

Students at the School of Engineering are enlisting bioengineering technology in the battle against one of mankind’s oldest foes: infectious bacteria. Searching for better ways to deliver doses of antibiotics over sustained time frames, Eleanor Pritchard, a fourth-year Ph.D. student in biomedical engineering, tested silk fibroin, a novel material derived from natural silk, to see if it fit the bill.

Fibroin was “an excellent choice for this study because it is safe, biocompatible and biodegrades when implanted. You can inject antibiotic-loaded gels or stuff a wound with an antibiotic-loaded silk sponge and it will degrade without your having to remove it,” says Pritchard, who works in the lab of David Kaplan, professor and chair of the department of biomedical engineering.

Pritchard and her colleagues studied how two common antibiotics, penicillin and ampicillin, were able to suppress bacterial growth of two dangerous bacteria—S. aureus and E. coli—when loaded into silk films, silk hydrogels and silk microspheres.

Silk films released the drug and suppressed all bacterial growth for 24 hours; silk gels suppressed the growth of S. aureus for two days and E. coli for three days; and microspheres suspended in silk gels released ampicillin and penicillin for four days. “These polymers could be used to coat implants to prevent infection, incorporated into bandages and packing materials and used in the treatment of infectious diseases,” says Pritchard.
 
As an added benefit, the team also found that penicillin stored in silk films was much more stable than in solution. “The ability to store antibiotics without refrigeration is attractive for Third World clinical settings” where continuous cooling isn’t always available, she adds.

The TB Connection

Tuberculosis runs rampant in Nepal, with nearly half the population infected with the disease, according to the World Health Organization. Tuberculosis is also endemic in the country’s livestock, but it is a different strain from that contracted by humans. Captive elephants, though, are susceptible to both strains of TB, and scientists wonder if they could play a role in spreading tuberculosis among humans and other animals.

In Nepal, people breed and train captive Asian elephants for use in the tourist industry, as well as for forest management. These working elephants regularly come into contact with humans, domestic livestock and wild animals, including deer, rhinoceros and wild Asian elephants.

Since 2006, Gretchen Kaufman, J76, V86, director of the Tufts Center for Conservation Medicine and an assistant professor of environmental and population health at the Cummings School of Veterinary Medicine, has collaborated with partners in Nepal to study these captive elephants. Together, the researchers laid the groundwork necessary to determine the elephants’ potential role in tuberculosis transmission in Nepal.

In addition to conducting a series of animal health and demographic studies, the team also used global positioning system (GPS) devices to establish the captive elephants’ ranges. Together, the health surveillance and location data will allow the researchers to better understand the elephants’ role in the spread of tuberculosis in Nepal. Their continued collaboration could lead to more effective management of TB in Nepal and other Asian nations.

The Mirror Effect

Fat. These days, it’s almost a four-letter word. But does society’s fear of fat help or hurt us in our efforts to slim down? Kristin Dukes, G07, now a doctoral candidate in social psychology, is investigating the influence of social and cultural factors on obesity. The principal investigator on a project funded by the National Institute of Diabetes and Digestive and Kidney Diseases, she explores the links between people’s attitudes about obesity in general, their own bodies and weight-loss behavior. She also looks at how the links between attitudes and behaviors may vary across race, ethnicity and socio-economic status.

Two-thirds of Americans are now overweight or obese, but women, minorities and the poor bear that weight disproportionately. Health-care professionals and the media commonly focus on the health consequences of being overweight.

“However, the continued increase of obesity in the United States implies that this approach may be ineffective,” says Dukes, whose Research Day poster examined anti-fat prejudice and how people from different backgrounds may internalize that social pressure.

Using questionnaires designed to measure attitudes regarding appearance, attitudes toward the obese and beliefs about the obese, Dukes found no correlations or links between external influences and personal body image and attitudes about personal weight loss.

Her data suggest that societal anti-fat prejudice has little impact on people’s own self-image or attempts to diet and exercise. Put simply, external messages and pressure about being overweight may have a limited impact on people.

“As you can imagine, these findings have many implications for weight-loss interventions,” says Dukes. “Understanding the influence of socio-cultural factors on weight is key to combating obesity and decreasing health disparities.”

Jacqueline Mitchell can be reached at jacqueline.mitchell@tufts.edu.

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