Before WWII, or better yet, before Japan's invasion of China in 1937, Shiro Ishii and Masaji Kitano were respected medical researchers. Ishii had graduated from the prestigious Kyoto Imperial University in 1916 , and Kitano from the equally prestigious Tokyo Imperial University in 1920. Both later received their Ph.D's in the study of infectious disease and related areas. Kitano was particularly interested in the effects of disease and injury on the intestines and digestive system.