Cloning.

This expression has two distinct meanings. One is the creation of a genetically identical animal by replacing the nucleus in the egg, with the nucleus from an adult animal that is to be copied. This is the process that produced Dolly the sheep, and made the new-born animal genetically identical to its parent. This process is used in animal breeding in agriculture, but it is specifically prohibited by all existing legislation relation to human reproduction, including New Zealand legislation.

The other use of cloning techniques is known as therapeutic cloning and does not involve the production of a foetus. By using the cloning technique of transferring the nucleus from the person to be treated, into an egg, embryonic stem cells will be produced and can be multiplied in culture for medical application. It is anticipated that the resulting cells, when used for treatment of the person, will have compatible genetic characteristics and immune reaction will be reduced.

Stem Cell Technology.

Stem cells are those cells which have the ability to continuously divide and develop into various kinds of tissue. They can be obtained from early embryos, foetuses from pregnancy terminations, umbilical cord blood, and adult tissues.

As these cells have the ability to develop into neurones as well as other tissues, there is interest in how they may be developed as treatments for a range of conditions for which there is particular complexity about providing effective treatment. The conditions for which they may provide promising advances are those that involve cell death, and for which the body does not seem readily able to provide its own repair. Examples are neurological disorders like Alzheimer's, Stroke and Multiple Sclerosis, vital organ damage such as heart disease, and inherited conditions like cystic fibrosis.

The value of stem cells may also be enhanced by additional techniques, such as genetically modifying them to ensure they express particular proteins. Or they might be cloned with cells of the transplant patient, to reduce the likelihood of immune rejection.

Therapies using cloned or genetically modified stem cells as a source of new cell development are not currently available and research on this approach is at early stages. However hematopoietic stem cells are used in transplant treatments as an alternative to bone marrow cells, and have proved effective in this.

There are ethical issues with stem cell research right at the early stages of the development of the technology. These issues arise because the sources of stem cells include fertilised embryos that are surplus to invitro-fertilisation procedures.