What is a stem cell?
Stem cells have the ability to divide for indefinite periods in culture and to give rise to specialized cells. They are best described in the context of normal human development. Human development begins when a sperm fertilizes an egg and creates a single cell that has the potential to form an entire organism. This fertilized egg is totipotent, meaning that its potential is total. In the first hours after fertilization, this cell divides into identical totipotent cells. This means that either one of these cells, if placed into a woman's uterus, has the potential to develop into a fetus. In fact, identical twins develop when two totipotent cells separate and develop into two individual,
…show more content…
For example, consider one of the best understood stem cells, the blood stem cell. Blood stem cells reside in the bone marrow of every child and adult, and in fact, they can be found in very small numbers circulating in the blood stream. Blood stem cells perform the critical role of continually replenishing our supply of blood cells — red blood cells, white blood cells, and platelets — throughout life. A person cannot survive without blood stem cells.
How pluripotent stem cells are derived
At present, human pluripotent cell lines have been developed from two sources1 with methods previously developed in work with animal models.
(1) In the work done by Dr. Thomson, pluripotent stem cells were isolated directly from the inner cell mass of human embryos at the blastocyst stage. Dr. Thomson received embryos from IVF (In Vitro Fertilization) clinics-these embryos were in excess of the clinical need for infertility treatment. The embryos were made for purposes of reproduction, not research. Informed consent was obtained from the donor couples. Dr. Thomson isolated the inner cell mass (see Figure III) and cultured these cells producing a pluripotent stem cell line.
(2) In contrast, Dr. Gearhart isolated pluripotent stem cells from fetal tissue obtained from terminated pregnancies. Informed consent was obtained from the donors after they had independently made the decision to terminate their pregnancy. Dr. Gearhart took
Embryonic cells should be allowed to be used because of the medical benefits they provide. They can be used to cure diseases such as Parkinson’s disease, diabetes, traumatic spinal cord injury, Duchenne’s muscular dystrophy, heart disease, and even vision and hearing loss (nih.gov 2009). There is no problem using them for medical purposes and it is not immoral to use them for this reason. Embryonic cells have the potential to save lives. Therefore, the usage of embryonic cells outweighs the ethical issues.
is a stem cell? Well basically they are cells in the human body that exist in a sort of neutral
The stem cell of the embryo can divide for long periods of time and still have the ability to produce all cell type in an organism. Their ability to do so is why scientists are trying to find ways to use them to cure or treat diseases. They think that they can programed to repair or replace the disease ridden cells of an infected patient Some diseases that they think can be
A stem cell is defined as a cell that can change into a different type of cell. Stem cells are different from other cells because from the start they do not have specialized functions. Embryonic stem cells are found within the blastocyst (embryo), which is just a tiny package of
The 70's focused on research that involved fetuses in utero. The 80's shifted to research of transplantation of fetal tissue into adults with serious medical conditions such as diabetes, Parkinson's, and spinal cord injuries. The latest saga involves using cells from days-old "spare" embryos that are created in infertility treatment process and all are considered unethical and unmoral issues.
Using various academic journals and articles found online (Internet), this paper seeks to cover the use of human stem cells (hSCs) in research for disease modeling and drug development.
Human embryonic stem cells (hESCs) are pluripotent and are obtained from the inner mass of a 4-5 day old human blastocyst that consists of approximately 100 cells (“Stem cell research,” 2009).
Firstly, what even are stem cells? Stem cells are cells that can turn into many different types of cells throughout your bedy. Think of it like a mother cell creating endless amounts of children. There are two kinds; pluripotent, ones that can turn into basically every cell in the body, and multipotent, ones that can only for a small number of cells.
Induced pluripotent cells from somatic cells by transduction, DNA-based induction, RNA molecules and recombinant proteins, creates a reprogramming wave leading to cells with the potential to become many cell types (16). The equivalency of induced pluripotent stem cells and embryonic stem cells is variable but using screening techniques, bioinformatics assay, cells that are more similar to embryonic stem cells can be selected for cloning techniques (18,19). The reprogramming wave, occurs in two parts, driven by c-Myc/Klf4 (first wave) and Oct4/Sox2/Klf4 (second wave),
Those people also argue that society would begin to accept the concept or destroying one potential life in order to save another. The final source of embryonic stem cells is opposed only because people find creating an embryo only to destroy it later is morally wrong and inhumane. Those that are in favor or neutral to creating the embryos point out that it is acceptable for an embryo that is created accidentally to be destroyed as a consequence of pregnancy, but to create an embryo with the intent to use the stem cells it is composed of to save a life is wrong (Hug). The second type of stem cell are pluripotent stem cells. Pluripotent stem cells come from fetal tissues instead of the embryo itself. Fetal tissues include the umbilical cord and the blood inside it, and the placenta. There is also a second kind of pluripotent stem cell. These stem cells are called induced pluripotent stem cells, or iPSCs. iPSCs are stem cells were adult stem cells, but have been reprogrammed into their embryonic stages. Though iPSCs resemble human embryonic stem cells, they are not usually accepted into the body, and so they are introduced to other adult stem cells with a virus that has caused some cancers to develop (National Institutes of Health).
We live in a world where genetic sciences have gone beyond laws, and past the imagination. We have come to a point where we don’t know anymore what is right, and what is wrong. We have to decide. In fact, studies are made on embryonic stem cells that for now have the purpose to better our overall health. These stem cells are extracted from extra IVF embryos; they are used and destroyed. While it’s true that this research could cure serious illnesses as Parkinson’s, Alzheimer’s, and orphan diseases for example; however, it’s also true that ending a potential life is immoral and illegal. We could definitely find an alternative to the embryonic stem cells to develop the science.
In essence, pluripotent cells are a universal building block within the human body, capable of becoming an eye, an arm, or even a nervous system.
Stem cells are cells that have the potential to become almost any cell in the human body, during the early developments of life. Stem cells have the possibility to generate all of tissues within a human as well. Each stem cell can either stay a stem cell or become a more specialized cell. The stem cells that are unspecialized are capable of renewing themselves or possibly being induced to become organ specific cells or tissue cells with special functions. Most stem cells have a constant supply to replace other cells that are injured, diseased, or even aged.
iPSCs are adult stem cells that have been genetically reprogrammed to behave like the pluripotent stem cells found in embryos, i.e. can differentiate into any cell type in the human body. This was first completed successfully in mice in 2006 by Shinya Yamanaka and his team (Takahashi et al., 2006), then in humans in 2007 both by Yamanaka (Takahashi et al., 2007), and by James Thomson and his team in America independently (Yu, et al., 2007). Yamanaka and Thomson’s methods were similar. In the report by Yu et
Stem cells are cells that have the capabilities to develop into many different types of cells in the body. Serving as a type of repair system for the body, they can theoretically divide without limit to take over for other cells for