Pedro was born in Madrid on September 27, 1936. In late 1939, his parents brought the family to Paris to escape fascist terror in Spain through a harrowing journey across the Pyrenees. Fearing a Nazi invasion, they fled to Columbia in 1940 and moved to Chicago in 1947. Pedro began undergraduate studies at Princeton University in 1954, but found it mind-numbing and soon transferred to Washington University in St. Louis. He stayed there to attend medical school, graduating in 1962. Pedro's interest in medical research was influenced by Washington University giants such as Carl and Gertie Corey, Bill Daughaday, Dave Kipnis, Oliver Lowery, Arthur Kornberg and Jack Strominger, as well as his classmates Stuart Kornfeld and Phil Majerus. After graduating from medical school, Pedro went to Johns Hopkins University for an internship and residency in internal medicine, determined to improve public health.
Pedro made his first major discovery while a resident. Noting that numerous patients under his care had problems with dairy products, he, along with trainee Dean Lockwood and medical student Jack Caldwell, developed a test for lactose intolerance based on measurements of blood glucose and lactase levels in small intestinal biopsies. This work is the first report of lactose intolerance.1 — found that about half of the 50 study participants had lactose intolerance due to lactase deficiency and was conducted without any external funding, technical assistance or faculty supervision.
