1.1.1 Stem cells are versatile cells in the body which are able both to reproduce themselves and to produce more specialized cells. As such, they are of great potential value in repairing and regenerating damaged cells and tissue. Many conditions are currently or potentially treatable with the use of stem cells, including Alzheimer's, Parkinson's, heart disease, stroke and diabetes.
1.1.2 Stem cells can be obtained from various sources. They can be obtained from the early human embryo, from the older human embryo or foetus, from the newborn baby (e.g. from the umbilical cord), from the older child and from the adult. As the individual develops, it is thought that stem cells become more committed to a particular destination in the body; however, some degree of flexibility appears to be retained. (We will be looking in the next section (2.1) at the clinical potential of adult versus embryonic cells.)
1.2.1 Embryonic stem cells can be obtained from the human embryo or foetus during or after an abortion, or after a miscarriage. They can also be obtained from the early human embryo after in vitro fertilisation (IVF) or similar procedures. The IVF embryo may be “spare”, ie. surplus to the infertile couple's requirements. Alternatively, the embryo may be specifically created for experimental use.
1.3.1 Embryos may very soon be created for experimental use by means of cloning. In this procedure, the nucleus of an unfertilised ovum is replaced by the nucleus of a body cell from an existing human being. The ovum is then stimulated to create an embryo. As the nucleus contains almost all of the cell's genetic material, the embryo created is the clone or twin of the human being from whom the nucleus was taken, and could be used as a source of stem cells for research and eventual transplantation.
1.3.2 Cloning for research is sometimes described as therapeutic as opposed to reproductive cloning. In “reproductive” cloning, the clone is transferred to the body of a woman and allowed to go to term. It should be noted that the cloning procedure itself is identical for “reproductive” and “therapeutic” cloning: the only difference lies in the purpose for which the clone would be created.
1.3.3 The terms “reproductive” and “therapeutic” in this context are misleading.1 “Therapeutic” cloning is not therapeutic for the clone, who will die in the course of its cells being taken when it is 5-7 days old. Such cloning is, moreover, reproductive, since it involves the creation of an embryo, although this embryo will not survive to the point of being born. Supporters of cloning have conceded that the clone embryo is a human organism: an early human life.
1.3.4 In this Submission, we will be referring not to “therapeutic” and “reproductive” cloning, but to cloning for birth, and cloning for research/transplantation.
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