 His early research was focused on peptic ulcer disease, and highly selective vagotomy and he developed a method to measure gastrin levels in antral vein blood long before sophisticated analysis methods to measure pg levels were established.Concerning antimicrobial therapy of surgical infection he started measuring antibiotic concentrations in tissue fluid representative for of the site of infection by analyzing body fluids and bone chips and that would have been disposed in the course of surgical procedures.Antibiotic concentrations measured in tissues was then be compared to concentrations required to kill bacteria to serve as foundation of anti-infective therapies.