Epilogue: a journey with blood cells and viruses.

THE FOCUS OF THIS JOURNAL, stem cells, strictly speaking is a subject on which I have neither published nor (unless unwittingly) worked on. Thus, although I feel both honored and grateful, nonetheless I also feel a little awkward to be featured in this Journal. Yet, oddly and quite by accident, I find myself at this very time becoming a new student of this topic, a point to which I will return at the end of this article. My first and continuous interest in research has been in the biology of blood cells—ones you could tell were really blood cells and not the phantom earliest progenitors. This interest began as a medical student at Jefferson Medical School, Philadelphia, in 1960, working in the laboratory of Alan Erslev, who was likely the first person to show in a laboratory setting the regulation of blood cell production by a human factor. Indeed, it might be justifiably stated that he was the discoverer of erythropoietin. We worked together on the impaired erythropoietic response in chronic lung disease (1). Alan advised me to head to either the Boston City Hospital or the University of Chicago for my internship and residency in medicine because these were “The centers of excellence in blood cell biology,” and I jumped at the suggestion. This notion was a bit naive because interns and residents did not then (and I assume now) have so much free time for research. I arrived in Chicago in July of 1963 and spent the next few years there. Despite the demands on the “house officers,” I could not fail to be moved by the presence of Leon Jacobson, a leader in the field of radiation-induced impairment of hematopoiesis, an erythropoietin expert, and Chairman of the Department of Medicine; Cliff Gurney, who seemed to have insights into every angle of blood cell biology; Stanley Yarcoan, a biochemist-physiologist of blood cells; Gerry Mendel, an iron-metabolism-erythropoiesis expert; and Gene Goldwasser, the first to purify erythropoietin (Epo) and to obtain its structural information. (Keep in mind that Epo was the first humoral factor to be described, purified, and analyzed for any blood cell, and among the first defined growth factors of any kind.) Then there was the indomitable Rudi Schmid, who had just arrived from the Thorndike Laboratories of Harvard’s Boston City Hospital, and was one reason why Erslev finally emphasized Chicago for me. Rudi’s interests, however, were more on the catabolic products of heme. One could hardly be surrounded by a greater collection of individuals involved in areas of research I wished to study. Cliff Gurney was also a generous man with a strong inclination to mentor. He opened his laboratory to me and fostered my independence. Consequently, despite the rigors of an internship and residency in medicine, I was able to produce a solo-authored paper on the regulation of heme biosynthesis due to Cliff Gurney (2). This was the time of the Viet Nam war. Many M.D.’s wished to avoid the draft and head to the National Institutes of Health (NIH) as research or clinical associates. Some of us wanted to go to NIH anyway because it was a place for M.D.’s to acquire the technical skills that seemed to be embedded in the character of Ph.D.’s but not of us. In those days it was strongly believed that “academically” oriented M.D.’s “had ” to go to NIH for a period. After all, that was the way of the current and past generation, and that was basically true. That is no longer true, perhaps due to a decline in the number of M.D.’s in the United States that are enamored with this kind of career, the increased opportunities in biotechnology companies, and the fact that NIH created its own competition by helping to develop so many centers of excellence in diverse areas of biomedical research throughout the country. But in 1965, NIH was the place for us.