There has been much controversy in the press recently about the pros and cons of stem cell research. What is the controversy all about? "Stem" cells can be contrasted with "differentiated" cells. They offer much hope for medical advancement because of their ability to grow into almost any kind of cell. For instance, neural cells in the brain and spinal cord that have been damaged can be replaced by stem cells. In the treatment of cancer, cells destroyed by radiation or chemotherapy can be replaced with new healthy stem cells that adapt to the affected area, whether it be part of the brain, heart, liver, lungs, or wherever. Dead cells of almost any kind, no matter the type of injury or disease, can be replaced with new healthy cells thanks to the amazing flexibility of stem cells. As a result, billions of dollars are being poured into this new field.
Where Do They Come From?
To understand the pros and cons of stem cell research, one must first understand where stem cells come from. There are three main sources for obtaining stem cells - adult cells, cord cells, and embryonic cells. Adult stem cells can be extracted either from bone marrow or from the peripheral system. Bone marrow is a rich source of stem cells. However, some painful destruction of the bone marrow results from this procedure. Peripheral stem cells can be extracted without damage to bones, but the process takes more time. And with health issues, time is often of the essence. Although difficult to extract, since they are taken from the patient's own body, adult stem cells are superior to both umbilical cord and embryonic stem cells. They are plentiful. There is always an exact DNA match so the body's immune system never rejects them. And as we might expect, results have been both profound and promising.
Stem cells taken from the umbilical cord are a second very rich source of stem cells. Umbilical cells can also offer a perfect match where a family has planned ahead. Cord cells are extracted during pregnancy and stored in cryogenic cell banks as a type of insurance policy for future use on behalf of the newborn. Cord cells can also be used by the mother, the father or others. The more distant the relationship, the more likely it is that the cells will be rejected by the immune system's antibodies. However, there are a number of common cell types just as there are common blood types so matching is always possible especially where there are numerous donors. The donation and storage process is similar to blood banking. Donation of umbilical cells is highly encouraged. Compared to adult cells and embryonic cells, the umbilical cord is by far the richest source of stem cells, and cells can be stored up in advance so they are available when needed. Further, even where there is not an exact DNA match between donor and recipient, scientists have developed methods to increase transferability and reduce risk.
Embryonic Cells
The pros and cons of stem cell research come to the surface when we examine the third source of stem cells - embryonic cells. Embryonic stem cells are extracted directly from an embryo before the embryo's cells begin to differentiate. At this stage the embryo is referred to as a "blastocyst." There are about 100 cells in a blastocyst, a very large percentage of which are stem cells, which can be kept alive indefinitely, grown in cultures, where the stem cells continue to double in number every 2-3 days. A replicating set of stem cells from a single blastocyst is called a "stem cell line" because the genetic material all comes from the same fertilized human egg that started it. President Bush authorized federal funding for research on the 15 stem cell lines available in August 2001. Other stem cell lines are also available for research but without the coveted assistance of federal funding.
So what is the controversy all about? Those who value human life from the point of conception, oppose embryonic stem cell research because the extraction of stem cells from this type of an embryo requires its destruction. In other words, it requires that a human life be killed. Some believe this to be the same as murder. Against this, embryonic research advocates could argue that the tiny blastocyst has no human features. Further, new stem cell lines already exist due to the common practice of in vitro fertilization. Research advocates conclude that many fertilized human cells have already been banked, but are not being made available for research. Advocates of embryonic stem cell research claim new human lives will not be created for the sole purpose of experimentation.
Others argue against such research on medical grounds. Mice treated for Parkinson's with embryonic stem cells have died from brain tumors in as much as 20% of cases.
1 Embryonic stem cells stored over time have been shown to create the type of chromosomal anomalies that create cancer cells.
2 Looking at it from a more pragmatic standpoint, funds devoted to embryonic stem cell research are funds being taken away from the other two more promising and less controversial types of stem cell research mentioned above.
UPDATE
Researchers have announced that embryonic cells are not the only stem cells now available for research. Stem cells can now be taken from living adult humans without harming the donor.
PROS
Some people think stem cell research has the potential to minimize suffering of people with many different diseases.
Some people think that stem cells can teach us about how cells become different from each other.
Some people think we will be able to grow replacement organs and prolong the life of people with disease.
The crux of the argument in bioethics committees (see link for AAAS) is whether excess embryos created for in vitro fertilization should be destroyed or used for research. The death of the excess embryos is inevitable either way. As bioethics committees use the four principles or derivations there of in their debates the principal of beneficence wins over the principal of non-maleficence where the parents' consent is obtained.
Good information about stem cell research is here: See related links
CONS
Some people think of embyos as having the potential for life and that potential should be preserved.
Some people think the embyos have dignity which should be preserved.
Some people think embryos have a soul.
Some people think that stem cell research constitues murder.
The crux of the matter for objectors is weither the right to life and dignity of the unborn child is being considered. Many would also object to the destruction of embryos in in vitro fertilisation. The use of adult cloned cells is considered very objectionable as it equates to creating a life(clone) with the express intention of destroying it.(See link to SPUC)
Extra Information being discussed:
Pros:
- Embryonic stem cells are plenty and are not hard to find
- Embryos do not classify as life, but do classify as Potential for life
- Embryonic stem cells do not cost a fortune to get
- Piles of different diseases could be cured by using stem cells, and this would save the NHS and other health services a huge amount of money since there would be less use of drugs
Cons:
- Adult stem cells are rare
- Adult stem cells are in some of the hardest to get to places, such as attached to the bone marrow
- Adult stem cells aren't really stem cells, stem cells are unspecialized cells whereas adult stem cells can only produce a certain type of cell, such as the blood cell
Pros of evolution include the diversity and adaptability of species, driving the natural selection process. Cons may include the potential for extinction of species that are not able to adapt quickly enough to changes in their environment.
Pros of marine biology include the opportunity to study and protect marine life, contribute to conservation efforts, and explore the diverse ecosystems of the ocean. However, cons may involve challenging fieldwork conditions, limited job opportunities compared to other fields, and potential risks associated with working in the marine environment.
Pros of being a microbiologist include the opportunity to contribute to scientific discoveries, potential for a rewarding career in healthcare or research, and the ability to make a positive impact on public health. Cons may include the rigorous educational requirements, potential for repetitive lab work, and limited advancement opportunities in certain sectors.
The human sclera is a tough, protective outer layer of the eye that helps maintain the shape of the eye and provides attachment points for the eye muscles. It also serves as a barrier against infections and injuries that could harm the delicate structures within the eye. Additionally, the sclera's white color helps to reflect light and protect the inner structures from excess light exposure.
Pros: -Cheaper -More enviromentally friendly as it takes less time to grow -sustainable because you can plant another tree in the place of the one you chop down Cons -Weaker than hard wood -lasts less longer than hardwood as it is easily broken Your welcome, Nihal Afsheen
Science is simply a method of observation and experimentation to answer questions. There is no way to list pros and cons for such a basic idea. There can be pros and cons to specific applications of science, but not to science itself.
deep
Pros of human experimentation is that you are helping people and may be finding out new things for the future. And if your worried about killing people you could always use somebody that's already killed someone. But then again you can think about the cons. The person that they are doing that to they could end up getting an illness or dying. So basically you can argue against both sides
the world will eventually and if do this
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PROS CONS ----------------------------------------------------- Pros: Entertaining Cons: Mental conditions can be caused, Adicition, Expensive.
Cons? What Cons?
what are the pros and cons of being an architect
Usually there are no pros or cons.