Professor Alexander Maximow: evolution of the ideas

Russian scientist-histologist professor of the Military Medical Academy Alexander Alexandrovich Maximow is one of the founders of conception about stem cells in general, and hematopoietic stem cells, particularly. Started to study the morphology of inflammation, within three decades he explored in detail the hemocytopoiesis in bone, described the different stages of this process. He formulated the idea of «polyblasts», a pluripotent precursor with lymphocyte phenotype (rounded cells with spherical nucleus), which moved out of vascular bed and were able to differentiate both into wandering phagocytic cells and fibroblasts in the inflammation site. The study of hematopoiesis in the evolutionary series of animals from cartilaginous fish to mammals led to the dominance of the hematopoiesis unitary model in embryogenesis and postnatal organisms' life. Despite the serious scientific debates around the world in the future (60-ies of XX century), exactly this model of hematopoiesis has been proved by the method of radiation chimeras and became accepted as a theoretical basis for hematopoietic stem cell transplantation.