What grade would you give this piece of coursework?
April 82010
Intro:
In this paper, I aim to explore and analyse the use of stem cells, gain an understanding of how they work, discover their potential and look at the intense debate which surrounds the issue, with an unbiased approach.
Inside an embryo no bigger than the full stop at the end of this sentence are dozens of stem cells. (*) Initially, these cells are blank slates, meaning that their fate is undecided, they have great potential. Stem cells are pluripotent, meaning they are capable of becoming any of the more than 200 types of specialized cells in our bodies.
Their almost limitless potential has no doubt attracted a lot of media attention and also made stem cells a significant focus of medical research. Imagine having the ability to return memory to an Alzheimer’s patient, restore skin that was previously lost during a fatal accident, or to enable a wheelchair-bound person to walk again. These are the scientist’s intentions however before scientists can use stem cells for medical purposes, they must first learn how to manipulate stem cells to get them to develop into specific tissues or organs.
What Is a Stem Cell?
A stem cell is basically the building block of the human body. The stem cells contained in embryos, eventually give rise to every cell, organ and tissue in the fetus’ body. Unlike a regular cell, which can only replicate to create more its own kind of cell, a stem cell is pluripotent, meaning they are capable of becoming any of the more than 220 types of specialized cells in our bodies. Stem cells also have the ability to self renew- they can produce themselves many times over.
Types of Cells:
There are two types of stem cells: embryonic stem cells and adult stem cells. Embryonic stem cells come from an embryo – the mass of cells in the earliest stage of human development that, if implanted into a woman’s womb, will eventually develop into a fetus. When the embryo is between three and five days old, it contains the stem cells in which are busily working to produce the various organs and tissues that will soon make up the fetus.
Adults also have stem cells in the heart, brain, bone marrow, lungs and other organs. They are our built-in repair kits, regenerating cells damaged by disease, injury and everyday wear and tear. Adult stem cells were once believed to be more limited than stem cells, only giving rise to the same type of tissue from which they originated. But new research suggests that adult stem cells may have the potential to generate other types of cells, as well. For example, liver cells may be coaxed to produce insulin, which is normally made by the pancreas. This capability is known as plasticity or transdifferentiation. So where do scientists get the stem cells they use in their research?
How to get human embryos
Embryos can either be made via reproduction – merging sperm and egg – or by cloning. Researchers aren’t likely to create an embryo with sperm and egg, but many use fertilized embryos from fertility clinics. Sometimes, couples who are trying to have a baby create several fertilized embryos and don’t implant them all. They may donate the ones that are left over to science.
Another way to create an embryo is via a technique called therapeutic cloning. This technique merges a cell (from the patient who needs the stem cell therapy) with a donor egg. The nucleus is removed from the egg and replaced with the nucleus of the patient’s cell. This egg is encouraged to divide either chemically or with electricity, and the resulting embryo carries the patient’s genetic material, which significantly reduces the risk that his or her body will reject the stem cells once they are implanted.
How to Make Stem cells
Embryonic stem cells are derived from blastocyst – embryos that are about a week old. At this stage, the blastocyst has about 100 cells. In order to get embryonic stem cell lines, scientists remove the cells from the inner mass area region. Once the cells are removed they are placed on a culture plate with nutrients and growth factors. The blastocyst is destroyed in the process. An embryonic cell line can then be recognized, when these cells begin to multiply and divide. Under the right conditions, these cell lines can be maintained indefinitely.
Treatments:
If scientists can ultimately learn how to direct stem cells to differentiate into one type of tissue or another, they can use them for two very important medical purposes.
First, pluripotent stem cells can be used to test new medications for safety and effectiveness. A medication could be tried out on a specific type of cell to gauge its response far more quickly than it could be tested in clinical trials. For example, scientists could use a cancer stem cell line to investigate whether a new anti-tumor drug stopped the cancer from growing.
Stem cells could also be used to repair cells or tissues that have been damaged by disease or injury. This type of treatment is known a
i only skim-read it…but i would give it a B and maybe an A
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