"CLONING AND STEM CELLS IN MEDICINE"
Nuclear reprogramming in livestock species is now routinely possible in our own and other laboratories, and may soon be used to clone cells and organs for transplantation into patients suffering from a wide range of disorders that result from tissue loss or dysfunction. In addition to patients with heart, liver, kidney, and lung disease, over 16 million patients worldwide suffer from neurodegenerative disorders such as Parkinson's and Alzheimer's disease, over 140 million patients suffer from diabetes, and millions more from arthritis, AIDS, strokes, and other diseases that may one day be treatable with cell and/or organ transplants. In addition to using cloning technology to make customized animal cells or organs that closely resemble human organs, there is also the potential to produce pluripotent stem cells that carry the nuclear genome of the patient. These cells could then be induced to differentiate into replacement cells, such as cardiomyocytes to replace damaged heart tissue or insulin-producing beta-cells for patients with diabetes. Although cloning would eliminate the critical problem of immune incompatibility, there is also the task of reconstituting the cells into more complex tissues and organs in vitro. I will discuss recent progress that has been made in this field as well as the inherent dangers and scientific and ethical challenges that remain before these techniques can be used to harness cells and tissues for human transplantation.