stem cell research

Stem cell research is intended to lead to the development of an infinitely renewable source of cells for cell-replacement therapies to treat disease. Embryonic stem cells, derived from 5–7 day old embryos, differ from other cells in the body in that they are both capable of self-renewal (i.e., able to divide and renew themselves), and are pluripotent (i.e., can differentiate into many kinds of specialized cell types, such as muscle or neuronal tissue). Research into embryonic stem cells seeks to identify precise approaches that would allow scientists to direct stem cell differentiation into specific tissue types, creating a source of tissue for transplantation to replace damaged tissues. Conditions such as Parkinson’s disease (see box below), spinal cord injury, muscular dystrophy, heart failure, and diabetes could conceivably be treated using these replacement cells.Progenitor cells, also called adult stem cells or somatic stem cells, are isolated from specific bodily tissues. Like embryonic stem cells, they are capable of self-renewal, but can differentiate into only a restricted range of tissues. For example, hematopoietic stem cells can differentiate into red blood cells, white blood cells, and platelets, while pancreatic progenitor cells can differentiate into insulin-secreting islet cells. The primary role of progenitor cells is to replenish the tissue from which they are cultured. Hematopoietic stem cells have been used in bone marrow transplants for the treatment of leukemia. The umbilical cords of newborn infants provide a source of cord progenitor cells that have hematopoietic origins. Stem Cells for the Future Treatment of Parkinson’s