Human Cloning

Stem cell therapy is a revolutionary new way to treat disease and injury, by transplant of new cells able to repair damaged tissues or organs. The creation of Dolly demonstrated that the normal developmental process of cellular differentiation could be reversible, since differentiated cells can be converted into all of the other cell types that make up a whole animal. This suggests a radical new approach to the problem of tissue incompatibility. Perhaps in the near future, when cells would be needed for transplants, it could be possible to obtain them by collecting skin fibroblasts or other cells and allowing them to proliferate before being converted into the specific cell type needed for the disease being treated. When these cells were returned to the patient, they would not be rejected because they have the patient's identical immune profile. At present, the only way to achieve such a transformation would be to collect a human egg (from which the nucleus had been removed) and incubate the resulting human embryo for six to seven days before recovery of pluripotent stem cells. Incubation of these cells with specific growth factors would then be used to obtain the desired cell type.

Conditions such as Alzheimer disease, Parkinson disease, diabetes, heart failure, degenerative joint disease, and other problems may be made curable from pluripotent stem cell technology. Several ethical problems have been raised regarding the use of human embryos for such a scope. In fact, before the stem cells are extracted from embryos, the embryos could potentially be implanted into the uterus and develop into a fetus. For these reasons, it has been proposed to use the frozen advanced embryos already in existence from in vitro fertilization protocols. However, even if all those embryos would be able to give proper stem cells, their number would never be sufficient to cover all the potential needs for stem cells.