Stem Cell Research Example #2
A stem cell is defined as a cell whose work in the body has not been determined. Stem cells have the ability to divide and specialize into various types of cells in the body. Every single cell in the body of an organism emanates from stem cells and that is why they are named stem cell, that is to say, the source. Ultimate direction of division for stem cells is determined by the signals they receive. They are extracted from embryos or pockets of adult tissue. Stem cells divide forever and depending on their source, they can spawn the full range of human tissues.
They are the repair system of an organism’s body; they divide limitlessly and replenish other cells. Division is dictated by a signal, without it they continue remaining stem cells. Otherwise they can divide and differentiate to become specialized cells such as white blood cells (Bouwens, 2004) Stem cells are central to three processes that occur in organisms namely: development, repair of adult tissues and cancer. Development begins with division of a zygote. As development occurs, cells undergo specialization until an organism is completely developed. Adult stem cells are believed to play a big role in replacement of injured tissues.
That is very common in blood cells and skin cells. Works on stem cells has also revealed that there is a great connection between development of an organism and cancer development. There are suggestions of the existence of what researchers have termed as ‘cancer stem cells’ (Priller, 2004). Both scientists and doctor are up beat about stem cell research because of its potential in areas of health and other biological research. Research in stem cells has grown from the 1960s. That is out of the work of two Canadian scientists Ernest A. McCulloch and James E. Till.
Mammals have two types of stem cells which include embryonic stem cells and adult stem cells. Embryonic stem cells are based in blostocytes while adult stem cells are based in adult tissues. Stem cells develop into specialized embryonic tissues in a developing embryo while in adults they play the role of repairing the body system, replenishing specialized cells and maintaining the turnover of regenerative organs like body blood skin or intestinal tissues (http://www. ama-assn. org/). Stem cells raise the possibilities of regenerating failing body organs and curing diseases that have for long resisted drug based treatment.
Researchers indicate that stem cells have a wide application in the treatment and cure of diseases and disorders. They argue embryonic stem cells can be influenced to divide into 220 various types of cells found in the human body. Their division process is indeed flexible. Embryonic stems are derived from human embryo. In stem cell research, embryos are normally destroyed to obtain them. That is the genesis of all the fuss surrounding stem cell research today . The prevailing controversies point to the ethics involved the culture and use of stem cells especially those derived from human embryos.
Pro-life groups advance the idea that life begins immediately after fertilization. In their arguments, once the ovum and spermatozoon have joined life has begun. Therefore it is homicidal to kill an embryo to extract stem cells. Pro-lifers generally oppose stem cells research. Others especially scientists who are pro stem cell research argue that an embryo is not a person but they have a potential to grow into a person. They point out that an embryo is not sentient, lacks ability to think, it is not aware of its surroundings, has no brain, it is unconscious and has no internal organs such as legs or head and so forth.
In that regard, they feel research on stem cells extracted from embryos follows the right ethics (http://fpc. state. gov/). Somebody may wonder why scientists do not opt for to adult stem cells and avoid the controversies of embryonic stem cells. Adult stem cells are not versatile and durable as embryonic stem cells. It is difficult to manipulate them to produce all cell types. That indeed limits their usage in treating diseases. Their ability to multiply is not as good as that of embryonic cells.
There are chances that adult stem cells contain abnormalities as a result of environmental hazards like toxins or have errors acquired that might have occurred during cell replication (Priller, 2004).. Humanity today is suffering greatly from diseases. There are many diseases in the world threatening human life from time to time. Stem cell research has the potential to treatment and possibly to cure debilitating diseases and injuries. Those diseases include diabetes, heart diseases, multiple sclerosis, Alzheimer’s and Parkinson’s diseases, paralysis, burns and spinal cord injuries among others.
People are spending millions to manage the diseases. Therefore a cure for them is likely to fix the problem once and for all. Statistics indicate 100 million Americans and about two billion people world wide suffer from diseases that could be treated or cured effectively using stem cells applications. Figures obtained from the focus on family action magazine, there are more than 70 diseases and ailments that are being treated using stem cells and 1,500 clinical trials underway(http://www. ama-assn. org/) Stem cell transplants (bone marrow transplants) have been carried out in the United States since the late 1960s.
The transplants have been used to treat diseases, such as blood cancer and aplastic anemia. For example bone marrow transplants have been used to treat leukemia. Adult stem cell transplants are done using cells harvested from ones bone marrow, circulating blood or umbilical cord blood. Adult stem cells have also been used in human experiments testing their potential in the treatment of diabetes, hear conditions and other diseases. Tests have begun to establish usage of embryonic stem cell for treatment in people. Currently underway are clinical trials using stem cells in treating neurological diseases (Barker & Widner, 2004).
Massachusetts General Hospital scientists have successfully managed to turn adult stem cells into insulin-producing cells that could reverse diabetes. Those scientists discovered that if adult stem cells are treated into the pancreas with a naturally occurring hormone, it can transform the stem cells into beta cells. The beta cells secrete insulin. That means pancreatic stem cells of that patient could be used to make new beta cells to produce insulin. In that regard, the insulin can be used treat that patient’s diabetes (http://www. ama-assn. org/. Research has also indicated that bone marrow stem cells can be used to repair retina.
In a research experiment, adult bone marrow stem cells were injected into the eyes of rats with damaged retinas. Later it was found out those eyes formed new retinal cells. The bone marrow stem cells incorporated were observed to have differentiated into retinal neural cells in the injured retina. Therefore, bone marrow stem cells have the potential being used in repairing damaged retinal cells. Research on mice, point to the direction that adult bone marrow stem cells could be used to prevent blindness. Scripps Research Institute scientists did a research on using bone marrow stem cells to grow new blood vessels in the eyes of mice.
The developments of that research lead to the conclusion that bone marrow stem cells could be used in the treatments some blindness in humans. When adult stem cells were injected into the eyes of the mice, they anchored in the parts of the eye where they were needed. Consequently they developed into new blood vessels that lead to prevention of blindness in the mice. Some working age Americans are suffering from blindness as a result of diabetic retinopathy. Muscular degeneration due to age is also a common cause of loss of vision in people over 60 years of age.
If research on curing blindness through the use of adult bone marrow stem cells is successful, both conditions are can be contained (http://www. ama-assn. org/ There is also stem cell therapy. The therapy involves replacing diseased, dysfunctional or cells that have been injured with either adult or embryonic stem cells. It is similar to organ transplanting but uses cells. In other circles, it is also called regenerative medicine. In stem cell therapy, stem cells were grown in the laboratory. The grown stem cells were then manipulated to enable specialization into specific types of cells such as nerve cells.
The manipulation involved changing the material in which the stem cells were grown or injecting genes into the cells. The resulting specialized cells were injected into a person. If the person has a lung disease, the cells would be injected into the lung muscle. The new and normal functioning of lungs cells, could replace the defective cells (http://www. ama-assn. org/. Embryonic stem cells can be created through therapeutic cloning technique. In the technique, a woman’s unfertilized egg is removed its nucleus. The adult stem cell of a donor is also removed it nucleus.
A donor could be a person with a disease such heart disease or suffering from injuries. The donor nucleus is then injected into the egg, replacing the nucleus that was removed. That process is called nuclear transfer. The egg then divides so as to form a blastocyst. The resultant is a line of embryonic stem cells genetically identical to that of the donor. A clone is therefore formed. That technique is also referred to as somatic cell nuclear transfer. According to scientists (not all), embryonic stem cells obtained from therapeutic cloning have some advantages over those obtained from fertilized eggs.
That is because they have little chances of rejection once after transplantation back to the donor. Embryonic stem cells also allows researchers to establish and see exact disease development. Therapeutic cloning is also considered as a good alternative to create embryonic stem cell lines from fertility treatments. That is because they come from cells that were unfertilized. There are infertile couples who choose to undergo in vitro fertilization (IVF) procedures normally done in fertility clinics. In the procedure, there are 16 or more surplus embryos.
Those surplus embryos can be thrown away, donated to other infertile couples (normally called embryo adoption), preserved for future use or donated for research. Due to emotional resources very few parents can willingly give their embryos to other couples. Preservation of surplus embryos is also expensive in that regard most couples ask that those embryos be discarded. Currently figures indicate there are many in fact hundreds of thousands of surplus embryos in clinics. By mid 2003, estimates indicated there were 400,000 embryos in store and the number has since been increasing (http://www. ama-assn. org/).
Instead of discarding those embryos, researcher would want to be utilized in enhancing stem cell research especially along the lines of finding a cure for various diseases. Through stem cells research, an opportunity arises to study growth and differentiation of individual cells into tissues. For the research to be useful and effective in people, researchers have to be certain that embryonic stem cells will differentiate into desired cell types. For instance, they would not want to transplant a stem cell into a person in the hope that it shall become a bone cell only to realize that it has become a heart cell.
That of course has dangerous consequences. The understanding of the processes involved provides the insights into the causes of birth defects, other diseases and even genetic abnormalities. Better understanding of the processes can facilitate possible prevention or corrections of those abnormalities. Stem cell research can produce large amount of stem cells. The cells can be useful in testing of new drugs’ effectiveness and chemical toxicity. Medical treatments can result to side effects. Those side effects can be overcome with stem cell treatments.
A good example is about cancer chemotherapy which kills immune cells in patients therefore reducing their ability to fight diseases. Stem cells are used to correct such adverse effects. Stem cell research may help scientists come up with cells and tissues that could be used for transplantation. Transplantation would help in treating many diseases. Stem cells are capable of propagating themselves. That makes research easier because they can be used for many generations while removed from their origins. They can also be replicated thus be used in large number of studies.
Pro-lifers present a number of cares against embryo stem cell research which include: Embryo murder. A trace to the origins of embryonic stem cell research indicates that an embryo was at one point destroyed. Extraction of original stem cells violated ethics of sanctity of human life. Therefore continued use those of cells or subsequent cells is immoral and a violation of United States’ rules on stem cell research. There is an argument fronted by the National Institute of Health’s lawyers that stem cells are not capable of growing into a person.
They can only be influenced to develop into specific cells. At most they argue they can only grow into an organ. As a result embryonic stem cells cannot be considered as a form of human life even within the definitions of pro-life crusaders. ((http://www. ama-assn. org/). Scientists argue that the surplus cells used in embryonic stem cell research could after all be discarded. However, pro-lifers suggests otherwise. They say it is possible to adopt those embryos in what is often referred to as rescue surrogacy. In rescue surrogacy, the embryo cells can be implanted and healthy babies be born.
Robert George a Professor at Princeton University argues that an embryo is a living member of human species. He points that embryos have the epigenetic primordial for internally directed growth and maturation. That is indeed distinct and self-integrating for humans (http://www. ama-assn. org/) Technical complications: the benefits of embryonic stem cell research can be obtained after many more years of research. That is because the technology has some technical hurdles. Those hurdles include developing the ability to control the differentiation of stem cells into required cell type such as a heart or a nerve cell.
So far, there are difficulties in regulating differentiation. There is also the problem of ensuring that cancerous tumors do not occur during development. Some experiment may result to development of a chimera (organism that contains two or more genetically distinct cells). If stem cells are used for transplantation, immune rejection can occur. Therefore, ways of overcoming immune rejection are also needed. However, some scientists think due to creation of more embryonic stem cell lines, various immunological types needed for use in tissue transplantation will eventually have to be established.
There is also a thought of ultimately developing a “universal donor’ as in the case of “universal blood donor” (Lindblad, 2004) To be able to fully utilize embryonic stem cell research optimally, scientists need to understand what underlies it. Scientists know that the turning on and off of genes is the engine behind the process. However, currently scientists do not yet fully comprehend the signals that turn specific genes on and off to influence differentiation process. Embryonic stems could become tumor cells. This has ever happened in animal experiments.
Embryonic cells when stored for some time they develop chromosomal anomalies that develop cancer cells. Cancer is deadly. Embryonic stem cells have the potential to trigger immune response. In the response recipients body attacks the stem cells as foreign invaders or they can just fail to function normally (Barker ; Widner, 2004). Embryonic stem cell science requires human eggs. This creates an avenue for exploitation of poor and disadvantaged women. For example “Egg Donor Business Booms on Campus” was a headline that appeared in the USA Today.
The story revealed how college girls were being enticed by being offered thousands of dollars to undergo high dose hormone treatments so that they could be extracted eggs surgically for embryo cloning. (http://www. ama-assn. org/) As a way of treating cancer, some patients may opt for stem cell and bone marrow transplants. Works on this has shown that there are many side effects associated with that form of treatment. The side effects that may arise include infections, anemia, bleeding, eating problems, graft failure, veno occlusive disease, acute graft versus host disease and chronic graft versus host disease (Barker ; Widner, 2004).
When such side effects occur, it may lead to more problems that what it was intended to cure. In the case of anemia, the number of red cells in the blood (or hemoglobin level) may go down. This causes conditions of feeling tired and weak. To counter that, a patient would need blood transfusion (to make enough blood cells) which can lead to other extra costs. Eating problems may occur due to lack of appetite, nausea or a sore mouth. Sore mouth may occur to low white blood cell either from ulcers caused by radiotherapy or from a fungal infection. Graft failure sometimes occurs.
That could be due the infusion of stem cells failing to work and the bone marrow also fails to produce enough new blood cells. The condition leads to repeated infections, bruising, bleeding and anemia. Total graft failure is rare but it occurs. Veno occlusive disease is a liver problem. It results due to high dose stem treatment one can be given be a transplant. It is a rare problem however it happens because blood vessels in the liver become swollen and blocked. The symptoms of the disease include; swelling and tenderness of the liver, weight gain, jaundice (yellowing of the skin) and fluid build up in the abdomen.
Acute graft versus host disease causes a severe skin rash. If the digestive system or the liver is affected, one can develop nausea, vomiting, diarrhea and jaundice. It normally occurs in the first 100 days of the transplant. Chronic graft versus host disease occurs after the first 100 days of a transplant. It affects different parts of the body causing various symptoms. The symptoms include: a dry and flaky skin, breathlessness and asthma-like symptoms, a dry and swollen mouth, gritty and dry eyes, diarrhea, stomach cramps and loss of appetite, repeated infections and muscle weakness.
In conclusion, this paper has highlighted the role of stem cells in basic biological processes, that is to say, in development, tissue repair and cancer development. Remarkable progress has so far been made in stem cell research. The most exciting application stem cells being the prospects of curing many deadly diseases like Parkinson’s and diabetes. Embryonic Stem cells have the ability to differentiate into various cells and their multiplication capacity is also enormous than any other cell type. However, three major hurdles exist on the way of Embryonic Stem cells utilization.
They include issues on ethics, rejection by the immunity and the potential of developing cancer. There are chances that in the future, adult stem cells from a patient shall be removed, manipulated and after which they shall be put back into the same patient so as to cure diseases. That shall cut on the usage of embryonic stem cells and eliminate the current politics regarding ethics and possibly minimize immunological rejection during transplants. However, currently cell embryonic stem cells are far more likely to produce a cure than adult stem cells.