Canadian biophysicist (1931–2025)
James Till
Born (1931-08-25 ) August 25, 1931Died May 18, 2025(2025-05-18) (aged 93) Education Known for Stem cells Awards Scientific career Fields Biophysics Institutions
Prof. James Till, 2018 James Edgar Till OC OOnt FRS FRSC biophysicist at theUniversity of Toronto , best known for demonstrating – in apartnership withErnest McCulloch – the existence ofstem cells .
Early life and work [ edit ] Till was born on August 25, 1931, inLloydminster , which is located on the border betweenSaskatchewan andAlberta .[ 1] Lloydminster , inAlberta ; the eastern margin of the farm was theAlberta –Saskatchewan boundary.
He attended theUniversity of Saskatchewan with scholarships awarded by theStandard Oil Company and theNational Research Council , graduating with a B.Sc. in 1952 and a M.Sc. in physics in 1954. Some of his early work was conducted withHarold E. Johns , a pioneer incobalt-60 radiotherapy . Till proceeded toYale University , where he received a Ph.D. in biophysics in 1957. He then became a post-doctoral fellow at theUniversity of Toronto .
Harold E. Johns recruited Till to theOntario Cancer Institute atPrincess Margaret Hospital shortly after he completed his work at Yale. Subsequently, Till chose to work withErnest McCulloch at theUniversity of Toronto in itsFaculty of Medicine . 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 injectingbone 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 & McCulloch were joined by graduate student Andy Becker. They cemented their stem cell theory and in 1963 published their results inNature [ 2] 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 theRoyal Society of Canada .
Later career and death [ edit ] In the 1980s Till's focus shifted, moving gradually into evaluation of cancer therapies, quality of life issues, andInternet research , includingInternet research ethics and the ethics ofList mining .
Till held the distinguished title of University Professor Emeritus at theUniversity of Toronto .
Later in life, Till was a vocal proponent ofopen access to scientific publications.
Until 2019, Till was an editorial member of theopen access journal Journal of Medical Internet Research .
Till was a founding member of the Board of Directors of theCanadian Stem Cell Foundation (no longer active).
Till died on May 18, 2025, at the age of 93.[ 3]
James Till with Steven Rosenberg in Edogawa Niche Prize Dinner, Toronto, 2019 References and selected publications [ edit ] McCulloch, E.A.; Till, J.E. (1960)."The radiation sensitivity of normal mouse bone marrow cells, determined by quantitative marrow transplantation into irradiated mice" .Radiation Research .13 (1):115– 125.Bibcode :1960RadR...13..115M .doi :10.2307/3570877 .hdl :1807/2782 JSTOR 3570877 . Till, J.E.; McCulloch, E.A. (1961)."A direct measurement of the radiation sensitivity of normal mouse bone marrow cells" .Radiation Research .14 (2):213– 22.Bibcode :1961RadR...14..213T .doi :10.2307/3570892 .hdl :1807/2781 JSTOR 3570892 .PMID 13776896 . Becker, A.J.; McCulloch, E.A.; Till, J.E. (1963)."Cytological demonstration of the clonal nature of spleen colonies derived from transplanted mouse marrow cells" .Nature .197 (4866):452– 4.Bibcode :1963Natur.197..452B .doi :10.1038/197452a0 .hdl :1807/2779 PMID 13970094 .S2CID 11106827 . Siminovitch, L.; McCulloch, E.A.; Till, J.E. (1963)."The distribution of colony-forming cells among spleen colonies" .Journal of Cellular and Comparative Physiology .62 (3):327– 36.doi :10.1002/jcp.1030620313 .hdl :1807/2778 PMID 14086156 . Till, J.E.; McCulloch, E.A.; Siminovitch, L. (1964)."A stochastic model of stem cell proliferation, based on the growth of spleen colony-forming cells" .Proceedings of the National Academy of Sciences of the United States of America .51 (1):29– 36.Bibcode :1964PNAS...51...29T .doi :10.1073/pnas.51.1.29 PMC 300599 PMID 14104600 . McCulloch, E.A.; Siminovitch, L.; Till, J.E. (1964)."Spleen-colony formation in anemic mice of genotype WWv" .Science .144 (3620):844– 846.Bibcode :1964Sci...144..844M .doi :10.1126/science.144.3620.844 .hdl :1807/2774 PMID 14149394 .S2CID 43571015 . McCulloch, E.A.; Siminovitch, L.; Till, J.E.; Russell, E.S.; Bernstein, S.E. (1965)."The cellular basis of the genetically determined hemopoietic defect in anemic mice of genotype Sl/Sld" .Blood .26 (4):399– 410.doi :10.1182/blood.V26.4.399.399 hdl :1807/3011 PMID 5317869 . Wu, A.M.; Till, J.E.; Siminovitch, L.; McCulloch, E.A. (1968)."Cytological Evidence for a Relationship Between Normal Hematopoietic Colony-Forming Cells and Cells of the Lymphoid System" .J Exp Med .127 (3):455– 464.doi :10.1084/jem.127.3.455 .PMC 2138458 PMID 5636553 . Worton, R.G.; McCulloch, E.A.; Till, J.E. (1969)."Physical Separation of Hemopoietic Stem Cells Differing in Their Capacity for Self-Renewal" .J Exp Med .130 (1):91– 103.doi :10.1084/jem.130.1.91 .PMC 2138673 PMID 4894546 . Sutherland, H.J.; Llewellyn-Thomas, H.; Boyd, N.F.; Till, J.E. (1982). "Attitudes toward quality of survival. The concept of "maximal endurable time"Medical Decision Making .2 (3):299– 309.doi :10.1177/0272989X8200200306 .PMID 7169936 .S2CID 25985187 . Mayer, M.; Till, J.E. (1996). "The Internet: a modern Pandora's box?".Quality of Life Research .5 (6):568– 71.doi :10.1007/BF00439230 .PMID 8993102 .S2CID 31584186 . Till, J.E. (2001)."Predecessors of preprint servers" .Learned Publishing .14 (1):7– 13.arXiv :physics/0102004 Bibcode :2001physics...2004T .doi :10.1087/09531510125100214 .S2CID 26820757 . Till, J.E. (2003)."Success factors for open access" .Journal of Medical Internet Research .5 (1): e1.doi :10.2196/jmir.5.1.e1 PMC 1550547 PMID 12746206 . Eysenbach, Gunther ; Till, James (2001)."Ethical issues in qualitative research on internet communities" .BMJ .323 (7321):1103– 1105.doi :10.1136/bmj.323.7321.1103 .PMC 59687 PMID 11701577 .
International National Academics Other
