ABSTRACT
In recent years, data from numerous experimental studies has suggested that the potential uses of stem cells in medicine may reach far beyond bone marrow transplantation. How applicable is recent research to modern medicine, and how soon might we expect to see stem cells applied to tissue engineering problems? These and other questions are explored in this introductory chapter. It is altogether fitting that a discussion of the therapeutic potentials of stem cell therapy be grounded in our field, being the first to apply stem cell therapy to the clinical management of acquired and inherited diseases. But what is a stem cell? In the context of bone marrow transplantation, we understand the answer to this question in a concrete and functional sense due to decades of research and clinical applications that grew out of the need to understand the effects of ionizing radiation on biological systems. In the years following the Second World War, a considerable amount of scientific effort was focused on the prevention and treatment of radiation sickness. From these studies came the observation that transplants of spleen or bone marrow cells contribute to cellular recovery following lethal radiation. 1 Almost 50 years after this dramatic insight, we now understand that the ability of such transplants to reconstitute hematopoiesis following radiation depends upon the presence of extremely rare stem cells found predominantly in the bone marrow but capable of mobilization into peripheral tissues via the blood vascular system. 2
