Professor at Saratov University, 1911-1925. Professor of Moscow University, 1925-1931. Director of the Institute for Haematology and Blood Transfusion, 1928-1931.
Vice-president of the USSR Academy of Sciences, 1942. President of the Ukrainian Academy of Sciences, 1930-1946. Created a large school of pathophysiologists in the USSR. An authority on endocrinology, the nervous system and gerontology.