Saturday 4 June 2011

Reproductive and therapeutic cloning

reproductive cloning (creating duplicate humans):

bulletConservative position:st "...scientists who envision medical breakthroughs using stem cells from human embryos are now moving on to human cloning -- breeding people for the purpose of havering their tissues and organs from their bodies, then disposing of them."
bulletLiberal position: "Human cloning allows man to fashion his own essential nature and turn chance into choice. For cloning's advocates, this is an opportunity to remake mankind in an image of health, prosperity, and nobility; it is the ultimate expression of man's unlimited potential."

therapeutic cloning (creating human organs for transplanting):

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  • Conservative position: "Cloning, even so-called therapeutic or experimental cloning, creates a new life without a father, and reduces a mother to the provider of an almost emptied egg. Nonetheless, it is a new human life and the determination to destroy it and limit its use to scientific research for therapeutic ends compound further the moral issues rather than protect mankind. As such, cloning embryonic human life under any circumstance crosses an ethical line, takes an irrevocable step, from which science can never turn back."
 
bulletLiberal position: "Therapeutic cloning will in time allow scientists to create organs that are a perfect match for those in need of a transplant. The cloned organ would be based on the recipient’s genetic material and would not require the use of debilitating immuno suppressive therapies. There would also be no chance of rejection, which is fatal. Therapeutic cloning represents the ideal in organ transplantation, as it would provide an unlimited source of organs to anyone who needs them. The need for these organs is dire."  The three different types of "cloning" are:
bulletEmbryo cloning: This is a medical technique which produces mono zygotic (identical) twins or triplets. It duplicates the process that nature uses to produce twins or triplets. One or more cells are removed from a fertilized embryo and encouraged to develop into one or more duplicate embryos. Twins or triplets are thus formed, with identical DNA. This has been done for many years on various species of animals; only very limited experimentation has been done on humans.
bulletAdult DNA cloning : This technique which is intended to produce a duplicate of an existing animal. It has been used to clone a sheep and other mammals. The DNA from an ovum is removed and replaced with the DNA from a cell removed from an adult animal. Then, the fertilized ovum, now called a pre-embryo, is implanted in a womb and allowed to develop into a new animal. As of 2002-JAN, It had not been tried on humans. It is specifically forbidden by law in many countries. There are rumors that Dr. Severino Aninori has successfully initiated a pregnancy through reproductive cloning. It has the potential of producing a twin of an existing person. Based on previous animal studies, it also has the potential of producing severe genetic defects. For the latter reason alone, many medical ethicists consider it to be a profoundly immoral procedure when done on humans.
bulletTherapeutic cloning : This is a procedure whose initial stages are identical to adult DNA cloning. However, the stem cells are removed from the pre-embryo with the intent of producing tissue or a whole organ for transplant back into the person  who supplied the DNA. The pre-embryo dies in the process.  The goal of therapeutic cloning is to produce a healthy copy of a sick person's tissue or organ for transplant. This technique would be vastly superior to relying on organ transplants from other people. The supply would be unlimited, so there would be no waiting lists. The tissue or organ would have the sick person's original DNA; the patient would not have to take immunosuppressant drugs for the rest of their life, as is now required after transplants. There would not be any danger of organ rejection.
There are major ethical concerns about all three types of cloning, when applied to humans.
                                   

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