University of Toronto Magazine University of Toronto Magazine

Mad About Science and Math

Rachel Tyndale, Vincent Tropepe, Deborah Fels, Shaf Keshavjee, Ed Doolittle, Akiko Iwasaki

Rachel Tyndale
If Rachel Tyndale has her way, Canada’s tobacco business will be going up in smoke. Since 1996, Tyndale, a pharmacology professor at the university and a researcher at the Centre for Addiction and Mental Health, has been studying why some people become addicted to nicotine and others don’t. A key breakthrough came in 1997, with the discovery of a genetic alteration that controls how the body processes nicotine. People who metabolize the drug slowly are less likely to become smokers, because the negative effects of nicotine – such as nausea and dizziness – last longer for them. If they do start, they tend to smoke fewer cigarettes, because the nicotine stays in their system longer. Tyndale (PhD 1992) and her colleagues have been able to mimic the action of the genetic defect and slow the progress of nicotine withdrawal in a person’s system. In 1998, she co-founded Nicogen Inc. with a view toward developing a drug therapy that will reach the marketplace within the next five years. Her ongoing research focuses on why some smokers don’t develop tobacco-related cancers – and it looks like the same genetic alteration may decrease risk. “It’s such a horrific battle for people to quit smoking,” says Tyndale, 39. “It’s a treat to work in an area that can have such a large impact on people’s lives.” – Hilary Davidson

Vincent Tropepe
Vincent Tropepe gets very close to the dawn of life. The 29-year-old developmental biologist looks at the embryos of frogs and mice to determine which of the early cells will become the nervous system. “There’s a clump of cells that all initially look the same, but some of them have already been set aside to become the nervous system,” he says. By figuring out the signals that tell cells to become neurons, scientists hope to learn to manipulate neural cells and cause them to regenerate. Progress would bring new hope to those who have sustained neural damage or trauma.

Currently a post-doctoral fellow at the Whitehead Institute of the Massachusetts Institute of Technology, Tropepe, who was born in Hamilton, Ont., earned his BSc at McMaster University and his PhD in developmental biology last year at U of T. While at the university, Tropepe was lead author of a study identifying a stem cell present in the adult eye. The research may be applicable in treating damaged retinas. “Before our study it wasn’t known whether retinal regeneration was possible in adult mammals, especially humans,” says Tropepe. Still, he cautions, “we’re years away from experimenting on humans.” – Helen Keeler

Deborah Fels
Thanks to Deborah Fels, a robot may be coming to your child’s classroom in the very near future. Fels is one of three co-creators of PEBBLES, a communications system that allows hospitalized children aged 5 to 12 to virtually attend their regular school via a live audiovisual connection.

The robot in question is four feet tall, with a bright yellow head that moves, a view screen (which contains a live video image of the child) for a face, a camera on the forehead and a hand that can be raised. “The child controls the robot from her hospital room using a Nintendo-type game pad,” says Fels, 38. “We’ve seen how dramatically things have changed for some of the kids who’ve used it.” Fels cites one example of a 12-year-old girl on dialysis who hadn’t been able to attend her regular school for four years. She was withdrawn and barely spoke at all. But when she started to virtually attend class three times a week, all that changed. “The high point was when she made a presentation in class via PEBBLES,” says Fels. “She had her teacher in tears.”

Fels, who received her PhD in industrial engineering in 1994, will see PEBBLES making a difference in many children’s lives in the near future; the U.S. Federal Department of Education has already committed to buying PEBBLES for pilot projects in classrooms in several cities. An associate professor in the school of information technology management at Ryerson Polytechnic University in Toronto, she is currently working on developing a high school version of PEBBLES. – Hilary Davidson

Shaf Keshavjee
When Shaf Keshavjee was a medical student at U of T in 1983, he heard on the radio that the world’s first-ever successful lung transplant had just been performed by Dr. Joel Cooper and a team of surgeons at Toronto General Hospital. He was so inspired by the accomplishment that he went on to study with Dr. Cooper. “I was very fortunate to be at U of T because I had exposure to leaders in the field,” says Keshavjee, who graduated with an MD in 1985 and an MSc in 1989. Exploring techniques to preserve a donor lung formed the basis of his master’s thesis and was one of the highlights of his work with Dr. Cooper, not the least because the technique they developed has become standard in Canada, Europe and, just this year, the United States.

After studying abroad at Harvard University and the University of London, Keshavjee, 40, returned to Toronto in 1994. In 1997 he took on the job of director of the Toronto Lung Transplant Program at Toronto General and the Hospital for Sick Children. He found the program was faltering, largely because of the brain drain to the U.S. Keshavjee revitalized it by making it a world leader in research. He started a pediatric program, increased the number of transplant surgeries from 24 to 50 a year and continued to develop techniques of lung preservation. The Toronto program is now pioneering research in gene therapy for lung transplantation: to prevent reprofusion injury – which leads to a donor lung being rejected by the body – specific genes are implanted in the lung before surgery. “If we understand the injury and understand the genes that control these injuries, we can improve the outcome after transplantation,” he says. – Hilary Davidson

Ed Doolittle
Ask a Mohawk how many fish he caught. He’ll say “a lot” or “not many.” Why count? In the unpredictable and complex world of nature, numbers are unreliable, and the precision of Western science is unlikely to tell you that one fish means “a lot” in a lake deadened by acid rain.

Ed Doolittle (BA 1990 UC, MSc 1992, PhD 1997) knows “a lot” about complex phenomena. Along with folk, or ethno, mathematics (the way a culture thinks mathematically), he specializes in hypoelliptics, or heat flow and wave motion. He wants to make a mathematical breakthrough, which is why, a year after completing his PhD, he moved onto the Six Nations reserve in Brantford, Ontario. “To do difficult things, you need a foundation, a spiritual strength and an identity, and those were missing for me,” says Doolittle, 34. His first major encounter with aboriginal cultures was at U of T. “Elders came to speak to students and that changed my life,” he says.

Come August, Doolittle will be an assistant professor of mathematics at Saskatchewan Indian Federated College in Regina. He is also learning the Mohawk language and says that endangered cultures such as the Mohawk’s must be preserved because they hold powerful ways of looking at the world. – Margaret Webb

Akiko Iwasaki
In the field of immunology, the most common way to study the immune system is through the blood. But Akiko Iwasaki, assistant professor at Yale University’s division of epidemiology of microbial diseases, follows a different approach: her lab is devoted to understanding the mechanism of immune response through mucosal surfaces – specifically through the female genital tract. “Isolating mucosal surfaces is much more difficult than studying blood,” says Iwasaki, 30. “But if we don’t understand this mechanism [of transmission], it will be more difficult to design a rational approach to protecting against disease.”

Iwasaki, who graduated from St. Michael’s College with a BSc in 1993 and earned a PhD in immunology in 1998, has already found some interesting results since she started working on the project in September 2000. For starters, a woman’s menstrual cycle may play an important role in determining immune-cell responses to sexually transmitted diseases. In experiments with mice, and more recently with primates, Iwasaki’s results suggest that the test subjects would contract the genital herpes virus only in the days just after menstruation, when the mucosal membranes are thinner and the distribution of the antigen-presenting cells is different from the rest of the month. The research suggests that “women need to be protected more at certain times,” says Iwasaki. “There are implications for HIV infection in this.” And more than that – there are also implications for the creation of vaccines to prevent herpes, AIDS and other STDs. 
– Hilary Davidson

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