John Kelly and Dr. Marcia Angell were advocates on opposing sides of a Massachusetts measure to legalize physician-assisted suicide. Jesse Costa/Jesse Costa/WBUR hide caption

itoggle caption Jesse Costa/Jesse Costa/WBUR

Dr. Jame Abraham used positron emission tomography, or PET, scans to understand differences in brain metabolism before and after chemotherapy. Dr. Jame Abraham hide caption

itoggle caption Dr. Jame Abraham

The number of new drug shortages each year in the U.S., from 2001 through Dec. 21, 2012. University of Utah hide caption

itoggle caption University of Utah

Brain scans using Amyvid dye to highlight beta-amyloid plaques in the brain. Clockwise from top left: a cognitively normal subject; an amyloid-positive patient with Alzheimer's disease; a patient with mild cognitive impairment who progressed to dementia during a study; and a patient with mild cognitive impairment. Slide courtesy of the journal Neurology hide caption

itoggle caption Slide courtesy of the journal Neurology

Doctors use tissue slides like this one of the ovary's outer cortex to confirm a woman's ovarian reserve. It's also the the ovary tissue that's removed in an ovarian transplant. Courtesy of the Infertility Center of St. Louis hide caption

itoggle caption Courtesy of the Infertility Center of St. Louis

Kristen Miller, a colonoscopy patient, sits with Dr. Stephen Hanauer at the University of Chicago Medical Center in Chicago in 2010. They're looking at an interactive computer program describing benefits and risks of the procedure. Brian Kersey/AP hide caption

itoggle caption Brian Kersey/AP

Chimpanzees check out a termite mound at the Chimp Haven sanctuary in Louisiana. Chimp Haven hide caption

itoggle caption Chimp Haven

The Ayurvedic remedies above were included in a 2004 study by researchers at Harvard Medical School that found dangerous levels of heavy metals in 14 out of 70 products. CHITOSE SUZUKI/ASSOCIATED PRESS hide caption

itoggle caption CHITOSE SUZUKI/ASSOCIATED PRESS

For centuries, Russians believed putting a brown frog in their milk would keep it fresh. Now scientists are finding chemicals in the frog's slimy goo that inhibit the growth of bacteria and fungi. Stefan Arendt/Corbis hide caption

itoggle caption Stefan Arendt/Corbis

Does a little sugar water before shots really help ease a babies' pain? If only they could tell us. Dmitry Naumov/iStockphoto.com hide caption

itoggle caption Dmitry Naumov/iStockphoto.com