Ingenious: Body Rocks

In the heart, calcium phosphate forms nodules that stiffen aortic valve flaps. (Image by Bruce Fouke)

When Bruce Fouke,  Illinois professor of earth science and environmental change, first came to the Mayo Clinic to make a case for incorporating geology into medicine, its physicians had never considered consulting geologists about rock formations inside the human body.

But through the Minnesota clinic’s resulting collaboration with the U. of I., Fouke and his team have demonstrated that the way kidney stones form is very similar to the formation of the mineral travertine, which comprises much of Yellowstone National Park’s Mammoth Hot Springs. When Fouke and his team looked at finely spliced kidney stone specimens from Mayo Clinic patients under the microscope, the stones’ elaborate patterns indicated that they dissolved and recrystallized over and over—just like travertine.

This discovery suggested that kidney stone treatments that could trigger the stones’ dissolution cycle could offer a potential cure for this painful and sometimes dangerous condition.

Fouke—who directs the university’s Roy J. Carver Biotechnology Center—and his researchers have started simulating human kidney conditions in their lab, testing various compounds to see how effectively they disintegrate kidney stones. As an example, one of the compounds is a homeopathic remedy used in India called “stonebreaker.”

The team is now applying these discoveries to the study of cardiovascular and breast-tissue calcification. With the former, Fouke’s team found that as tiny particles of calcium phosphate grow in the heart, they form nodules that stiffen the flaps of the aortic valve. This calcification can cause the flaps to harden like stone, which can be fatal. However, the researchers also found that one of the body’s naturally occurring proteins, osteopontin, defends against this hardening. Fouke and his team hypothesized that if they could find ways to release more osteopontin into the body, they might be able to slow heart calcification, reducing the need for aortic-valve replacements.

The team is simultaneously studying calcification in breast tissue and how it presents itself. Although benign calcium phosphate deposits may look the same as cancerous calcifications in a mammogram, the researchers discovered that they form differently. This knowledge should improve the accuracy of mammograms and reduce biopsies, which pose risks of their own, Fouke says.

Since he joined Illinois’ faculty in 1997, Fouke has taken thousands of students to more than 35 locations around the world, including the Great Barrier Reef, Italy, and Sweden, in addition to Yellowstone, to learn all that rock formations have to teach. The common denominator among all their explorations is what he calls “the eternal triangle”—the interaction between life, minerals, and water—whether at a Wyoming hot springs or in the recesses of the human heart.

“We now have the technology to analyze the parts of this puzzle, this eternal triangle, in ways we never had before,” Fouke says.