Human Embryonic Stem Cell Research – Alternative Ways To Harvest Eggs
Success with adult stem cell research has not diminished the desire to carry out embryonic stem cell research. Scientists see human embryonic stem cell research as their best hope for cures of diseases such as cancer, diabetes and Parkinson's disease. The ethical problems of this kind of harvesting of stem cells has led scientists and medics to look for other ways to harvest cells for human embryonic stem cell research. Parthenotes are eggs which can develop into an embryo and create embryonic stem cells. The ethical debate is about exactly where human life begins, ad these parthenotes are then destroyed as they are divided for embryonic stem cell research. Any advancements which get around the problem of this parthenote being viewed as already being a human life are welcomed as a way to possibly continue human embryonic stem cell research with the backing of all but the hard-line religious fundamentalists who consider any kind of search for a cure for diseases as 'playing God'.
Let's take a look at the way human embryonic stem cell research has sought alternative ways to harvest and develop embryos other than from those embryos which would otherwise be discarded as not needed after a couple has successfully undergone in vitro fertilization treatment. Chemical triggers One of the latest developments in human embryonic stem cell research has taught us that even unfertilized eggs can be prompted into beginning to divide by a chemical trigger. Being unfertilized, they would never become human life, which should side step that particular objection. However, there is still a problem with this particular method of harvesting human embryonic stem cells; research shows that since eggs have only half of the requisite DNA, they would have to be obtained from women before ovulation when the egg still has a full DNA compliment, or the eggs would have to copy their own 23 chromosomes to produce 46 chromosomes when exposed to a chemical trigger such as an electric shock. This trigger fools the egg into believing it has been fertilized and it begins to develop, and it can then be harvested and divided so that it can be used for human embryonic stem cell research without ever having to be fertilized. It's not certain, though, how useful embryos harvested in this way would be, though, as they do not have the full compliment of DNA supplied half by the fertilizing sperm; therefore, it may develop differently from a normal human embryonic stem cell; research has yet to find out if that is the case. Morula proposal When the embryo has divided to approximately the eight cell stage it is termed a 'morula'. Human embryonic stem cell research ahs experimented with removing a cell from the morula and analyzing it for disease and genetic disorders. Only embryos seen not to have these diseases are then implanted back into the woman, which would rule out the embryo developing these medical problems. Embryonic stem cell research could potentially be carried out on that one removed cell whilst the rest of the embryo is implanted in the woman and allowed to develop in pregnancy. This seems problematic in that it is not know what effect removing the cell at such an early stage would have on the embryo, and also, it is unlikely that doctors would implant embryos which are known to have such disorders. Organ transplant method This is not exactly human embryonic stem cell research, since it is carried out on adults and children who are on life support machines and about to die, but the argument goes that if it is Ok to harvest kidneys and hearts in this way, one should be also able to harvest stem cells from people on the brink of death in this way. This leads on to another similar argument which human stem cell research gives as a way to harvest stem cells: Prior to in vitro fertilization, many eggs are harvested; some of these never develop when implanted in the womb and it is argued that those embryos are brain dead - like a human undergoing organ harvesting. Some doctors would like to be able to carry our embryonic stem cell research on those stored embryos which are brain dead and would therefore never develop if they were implanted in a womb. The problem with this is that no-one has as yet decided criteria by which to judge brain death in embryos. Let's now look at our final potential method of harvesting embryos for embryonic stem cell research: The Alternate Nuclear Transfer (ANT) Proposal This us similar to cloning, as scientists would develop an embryo for human embryonic stem cell research which lacked the development gene and would therefore never become a viable human life. Turning off the developmental gene in this way is now an ordinary part of the cloning process which they are adept at carrying out. The crux of this argument though, remains at which point human life really begins. Is the embryo, even unfertilized, a human life? If it is considered so, then it is difficult to see any method of harvesting the eggs for human stem cell research being approved of; if some other criteria is to be used, then the above methods offer some hope of getting around certain moral objections. |