Isidore Snapper grew up in a Jewish family in Amsterdam.1 His father David Snapper (1889-1973) was married to Helena Barends. He was a diamond cutter. Isidore Snapper married Henrietta Maria Jacqueline van Buuren, a merchant's daughter, on December 1, 1911. The couple had two sons and a daughter.
Studies and Medical Training in the Netherlands
Isidore attended the Stedelijk Barlaeus Gymnasium in Amsterdam. After an early graduation from high school, he began studying medicine at Amsterdam University in 1905 at the age of 16. He became an assistant to Benjamin Jan Kouwer, professor of obstetrics and gynecology at Utrecht University in 1911. Snapper quickly became dissatisfied here because of a lack of research opportunities. He moved to Groningen to join physiologist Hartog Jacob Hamburger in 1912. Snapper assisted Hamburger in his research on the permeability of cell membranes. He received his doctorate with honors from Hamburger with a thesis on chlorine retention in febrile illnesses on May 23, 1913. Snapper turned to internal medicine in 1917, when he studied bile pigments in the blood under Abraham Albert Hijmans van den Bergh, also in Groningen. When Hijmans van de Berg moved to Utrecht in 1918, Snapper returned to Amsterdam. Here he worked as an assistant to Pieter Klazes Pel, who was succeeded by his son-in-law Pieter Ruitinga after his death in 1919. Snapper in turn became Ruitinga's successor.
Generalist and Soccer Referee
In Amsterdam, Snapper continued the path he had taken in Groningen. He presented himself as a generalist who, contrary to the trend toward specialization, emphasized the importance of internists who had mastered the full breadth of their specialty. Nevertheless, Snapper set research priorities in the areas of renal metabolism, blood and liver diseases, and skeletal diseases.
Snapper made his mark on prewar internal medicine from the Wilhelmina Gasthuis, which was named Amsterdam's second university hospital alongside the Binnengasthuis in 1925. Snapper lived for more than just science. His interests also included soccer. He was a referee in the highest Dutch league between 1920 and 1931. The Amsterdam professor also refereed international matches. He combined the corresponding stays abroad with scientific lectures and hospital visits.
New Experiences in the Far East
The increasing threat of war and a conflict with the faculty, prompted Snapper to leave the Netherlands. The Rockefeller Foundation appointed him professor of internal medicine at Peiping Union Medical College in Beijing in 1938. Snapper settled in the Chinese capital with his wife; their children were now grown up and initially remained in the Netherlands. In China, Snapper developed the thesis, which was later confirmed, that the comparatively low incidence of cardiovascular diseases there and the lower average cholesterol levels compared with Europe were related to diet.
Shortly before the German invasion of the Netherlands, Snapper submitted an application for an extension of his leave of absence from Amsterdam University. This was not approved. Snapper nevertheless remained in the Far East and severed his ties with the University of Amsterdam.
New Home in the USA
He was arrested as an enemy alien in Japan in 1941, but soon came to the United States through a prisoner exchange. After an initial stint as a consultant to the surgeon general of the U.S. Army, Snapper was appointed chief of the Second Internal Clinic at Mount Sinai Hospital in New York in 1944. He received a concurrent professorship at Columbia University.
Snapper remained in the United States permanently. From then on, he received many Dutch colleagues who visited America. To some, he recommended a scientific career in the United States, including his cousin, biologist Leo Vroman, and physician Willem Kolff, who had developed the first artificial kidney in the Netherlands during the war. Both followed his advice. Snapper became a corresponding member of the Royal Netherlands Academy of Arts and Sciences in 1952. He also went on regular family visits to the Netherlands over the years. During such stays, he also gave well-attended lectures and went to soccer matches as a spectator.
Snapper left Mount Sinai Hospital in 1952, but remained active at various other hospitals and training centers, such as Cook County Hospital in Chicago and Beth-El Hospital in Brooklyn, until old age. He was the editor of the journal Advances in Internal Medicine from 1954 to 1968.
Snapper was definitely considered authoritarian, even arrogant, which was part of his charismatic personality.