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U. professor helps ease others' pain: His
snail research leads to FDA-approved drug |
| By Joe Bauman, Deseret Morning News |
The senior at Hillcrest High School isolated a substance in the poison secreted by the cone snail Conus magus, a fish-hunting animal living on the bottom of shallow ocean areas. As he advanced toward his degree at the university, he purified the substance, dubbed omega-MVIIA, and identified its chemical structure. Today, McIntosh is a medical doctor, a professor of psychiatry at the U.'s School of Medicine, and a research professor of biology. He continues to carry out research on beneficial properties of cone snail toxin. And three days after Christmas, and about 25 years after McIntosh began his lab work at the U., the Food and Drug Administration gave its formal approval to Prialt, the synthetic version of the substance he studied. Marketed by the Irish company Elan Corp., the drug may be used to manage severe chronic pain in patients who are not helped by other treatments, including morphine. "He started working in the lab when he was 18 years old," recalled his mentor, the laboratory's director Baldomero "Toto" Olivera. "Even then, it was clear that he was gifted and focused." A distinguished professor of biology, for decades Olivera has researched cone snail toxins searching for new medicines. Why cone snails? The animals carry an amazing variety of neurotoxins, and these materials can be useful. An old adage has it that dosage determines a poison; in high doses, water can kill. Some cone snail toxins, while paralyzing or deadly to small fish, may provide relief to humans at the correct concentrations. According to the university, U. biologist Doju Yoshikami determined that the factor that McIntosh isolated blocked signals running along nerve cells, thus stopping the transmission of pain messages. Olivera and Yoshikami developed the omega-MVIIA for use in basic research, according to a university press release. In a Deseret Morning News telephone interview, McIntosh recalled that it all began when he was going to Hillcrest and thinking about attending the university. "I took a tour of the biology department, because that's what I was interested in majoring in," he said. He visited a laboratory, which happened to be Olivera's. An undergraduate student was working there, and "I just asked him how it was that he got the job and how he liked it." The young man was enthusiastic about the lab and said the university had offered him a scholarship, connected with the job. McIntosh thought he would do the same. He landed a position there, too. He was "assigned to try to purify a venom" from components that act on the brain. "And so I went to work on that assignment, and one of the compounds that I isolated was this compound that's now become Prialt." Continuing to work with Olivera, McIntosh graduated from the university and went on to the UCLA Medical School. After earning his medical degree, he did speciality training in psychiatry at the University of Colorado. But he remained enchanted with laboratory work. "I found I missed the research so much that I wanted to find a way to be able to continue with it," he said. Keeping an eye on the research that Olivera was doing, he wrote to the National Institute of Health, seeking funding for a grant so he could return to Utah and work on projects he had begun years before. Before long, McIntosh returned to Salt Lake City. "Toto Olivera and I collaborate together in continuing to examine the components of these venoms for additional compounds that may have medical potential and serve as tools for neuroscientists," he said. McIntosh also works at the U. Medical Center as a practicing psychiatrist and teaches there. About 500 species of cone snails are known, McIntosh noted. They have different strategies for paralyzing or killing their prey. Of these 500, the researchers have studied about 100. Each venom produced by the cone snails has about 200 different components, such as the factor isolated by McIntosh. The venom varies among species, and the components are different, too. As a result, tens of thousands of chemical compounds are secreted by the snails, each working somewhat differently on the nervous system. That means the number of potential medicines derived from cone snail venom may be huge. "Everything that these snails make is designed to affect the physiology of a prey that they are trying to capture, so it is a very rich source of materials," McIntosh said. He and Olivera are among founders of a Salt Lake City company, Cognetix, that strives to develop additional treatment compounds based on snail venom. Painkillers are not the only use of these substances, he said, although Cognetix is working on one that may be a great blocker of pain. "There are other compounds," McIntosh said, " - one that looks like it may be useful for treating patients who have suffered a heart attack (or) for patients who have suffered a stroke." |
