Stem cells are a small group of cells found in the umbilical cord of a new born baby, Blastocyst embryos and some organs of the body. Research is being conducted into the potential medical uses of stem cells for growing replacement organs. This research is carried out under very strict guidelines which prevent any exploitation of the research and prevent it from becoming too close to cloning. Current stem cell research is focusing on the need to develop growth factors that can trigger a stem cell culture to differentiate into a cell type, be it liver, lung kidney or heart.
Development of these growth factors for any kind of cell type in the human body would have massive implications for medical science and potentially drugs testing. There has been a recent development in which a group of liver cells were grown in the laboratory solely from stem cells. This was only possible due to a growth factor that essentially activates or deactivates genes within the stem cells. Once the gene has been "turned on" transcription of the DNA into mRNA occurs. This mRNA codes for the specific gene and tells the stem cells what cells to develop; in this case it was a liver cell.
The above case is particularly applicable to embryonic stem cells and Cord blood stem cells. Both of these cell types are undifferentiated and have the potential to develop into any other type of cell in the body, but not a complete organism. This makes them pluripotent. They have the potential to become many other cells. All embryonic stem cell research is carried out with embryo's that have undergone in vitro fertilization. This means that fertilization occurred in the laboratory, not in a host.
This gives rise to the procedure of therapeutic cloning, which entails taking a diploid cell from a patient, fertilizing the embryo with this cell and stimulating growth in the embryo using an electric impulse. If the embryo develops into a Blastocyst, the stem cells are removed and cultured. If they develop into an organ after being exposed to the correct growth factor, the organ would have the exact same genetic information as the recipient of the organ. This technique is very unreliable and as of yet only a few encouraging results have been reported.Adult stem cell research is a little simpler as these cells are more differentiated than the embryonic stem cells or cord blood cells. The adult stem cells have the potential to become a range of other cells but only those that appear cord blood cells.
The adult stem cells have the potential to become a range of other cells but only those that appear cord blood cells. The adult stem cells have the potential to become a range of other cells but only those that appear in the organ from which they were extracted.For example liver cells if the stem cells were extracted from the liver. Virgin has recently opened up a stem cell bank in which the parents of the child pay for their Childs stem cells to be stored for future use. "in your child's early years; their own stem cells are unlikely to help if they fell ill - they'd need healthy, donated cells - which is why we've designed an exciting new service for banking your baby's cord blood stem cells. "i Ethical concerns about stem cell research There are several ethical problems that have been raised over the research into uses of stem cells.
One of which is that the cord blood stem cells should not be extracted from a baby's umbilical cord. This is because some people believe that the baby should be given a choice as to whether its stem cells are extracted and frozen. However, as the child cannot give its view on stem cell extraction, they should not be extracted. Another concern is that the embryonic stem cells require the destruction of an embryo which is some people's views is morally wrong.
This is because each embryo has the potential to create a complete living organism, and is being destroyed in order to extract stem cells.Second biological principal: the uses of stem cells in medicine. Stem cells potential to generate any cell type provides massive medical implications. Embryonic Stem cells can be used to produce other cells and therefore, any organ of the body required for treatment. Entire organs could be grown in culture and then transplanted into the patient's body.
Stem cell organs could then be transplanted into the recipient. There is however a risk of rejection. At present, drugs are used to prevent recipients from rejecting the transplanted organs.A technique referred to as therapeutic cloning could also be used to create organs. A suitable tissue sample is taken from the recipient's body and a cell from that sample is fused with an ovum to create a diploid cell.
This is similar to a zygote. The cell could then be stimulated into undergoing division. Once the embryo has become a Blastocyst, the stem cells could be harvested and cultured. Stimulation to generate a certain cell type could be performed and the cells left in culture.
Organs could potentially be created from these cells and transplanted into the recipient.There is no risk of rejection as the organs would have the same DNA as the recipient as their DNA was used in creating the organ. In order to grow an organ in culture, a fertilized embryo would be needed that had developed into a Blastocyst with stem cells present. The stem cells are cultured and a "trigger" is added to stimulate genes to become active. This would give the stem cells the information needed to produce the desired cell type. However, the "trigger" has yet to be discovered for all cell types in the human body, severely limiting their use in current medical research.
Scientists have recently grown a segment of human liver from the stem cells extracted from the umbilical cord of a baby. This was a medical breakthrough as stem cells had never been used to grow an organ. If stem cell organ transplants are to be used in the future, it is believed that as little as "20 stem cell lines would be needed for 90% of the UK population. " ii This not only gives rise to the possibility of using stem cell grown organs as transplants, but also for drug testing.Entire organs could be grown and subjected to doses of drugs undergoing medical trials to examine their effects on organs of the body.
This would reduce the risk to humans undergoing unsafe trials, in which adverse reactions occur. This would also reduce the costs imposed on drug companies as the need to pay the participants of the trial in the early stages would be abolished. There have already been applications for the use of stem cells in spinal injuries. Stem cells mixed with retinoic acid are injected into the damaged area of the spinal cord.After several weeks, the stem cells will have migrated away from the area in which they were injected and in many cases movement is possible in the body area below the damaged part of the spinal chord.
There are very few neurons found which make it possible to move but their numbers are currently limited and recovery from paralysis is mostly only partial. But this is still a development in the uses of stem cells. A group of type I diabetics have recently undergone a form of stem cell therapy in order to remove their dependency on insulin.This has proved a successful technique involving adult stem cells.
These stem cells were extracted from the pancreas and triggered to form functioning islet like cells, which are the cells in the pancreas which produce insulin. This effect has lasted for upto 3 years in some cases. Ethical concerns surrounding stem cells in medicine. There are many ethical concerns surrounding stem cells usage in medicine. The main concern being that the embryos used to extract the stem cells have the potential to become a complete organism and so they should have the same rights to life as all other humans.
Many religious groups believe that "... it is ridiculous for people who have already decided that it is moral to kill babies in the womb to show some squeamishness about destroying human embryos in a Petri dish. Hell, man, once you decide to become a child-killer, their ages no longer matter.
" These are the very strong views of a religious person. However, the embryos used to extract the stem cells are all "left overs" after IVF treatment has been completed.These embryos are destined to be destroyed if they are not used for medical purposes, so they are never going to be given the real chance to develop anyway. "I am acutely aware of the ethical sensitivities that have been expressed regarding the sources of stem cell lines. But, surely, obtaining cells from legally obtained abortants or from early stage embryos that are destined to be discarded in the course of IVF procedures and making them available for potentially life-saving purposes would be viewed as ethically permissible if not a moral imperative.Economic factors concerning the use of stem cells in medicine.
Should this stem cell treatment be available on the NHS or should the patient be made to pay for this potentially life saving treatment. There are concerns that if stem cell treatment was fully developed that the costs of treatment would be very high due to the need for embryo donors and the storage of these embryo's.
