Stem Cells
Harold Johns recruited Till to the Ontario Cancer Institute at Princess Margaret Hospital shortly after he completed his work at Yale. Subsequently, Till chose to work with Ernest McCulloch at the University of Toronto. Thus, the older physician's insight was combined with the younger physicist's rigorous and thorough nature.
In the early 1960s, McCulloch and Till started a series of experiments that involved injecting bone marrow cells into irradiated mice. They observed that small raised lumps grew on the spleens of the mice, in proportion to the number of bone marrow cells injected. Till and McCulloch dubbed the lumps 'spleen colonies', and speculated that each lump arose from a single marrow cell: perhaps a stem cell.
In later work, Till and McCulloch were joined by graduate student Andy Becker. They cemented their stem cell theory and in 1963 published their results in Nature. In the same year, in collaboration with Lou Siminovitch, a trailblazer for molecular biology in Canada, they obtained evidence that these same marrow cells were capable of self-renewal, a crucial aspect of the functional definition of stem cells that they had formulated.
In 1969, Till became a Fellow of the Royal Society of Canada.
Read more about this topic: James Till
Famous quotes containing the words stem and/or cells:
“Ignorance, the root and stem of all evil.”
—Plato (c. 427–347 B.C.)
“The twelve Cells for Incorrigibles ... are also carved out of the solid rock hill. On the walls of one of the cells human “liberty” is clearly inscribed, with the “liberty” in significant quotation marks.”
—Administration in the State of Ariz, U.S. public relief program (1935-1943)