Over the past decade, stem cell biology has been an area that has caused much controversy. Stem cells have the ability to differentiate into many different types of cells and therefore, advocates of stem cell research argue that the cells have various medical applications. On the other hand, opponents of stem cell research denounce the use of human embryos for research purposes, claiming that the embryos represent human lives and that experimentation with them and subsequent annihilation of them is the same as killing a living human being. Nevertheless, the potential uses for stem cells are endless and stem cells have the ability to completely change modern medical practices.
Human embryonic stem cells (HESCs) are characterized by
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Prior to 2001, the primary method used to isolate embryonic stem cell lines was to identify and segregate single colonies under a dissecting microscope. However, this process was time-consuming and costly and served to inhibit stem cell research. A new method has been developed that involves introducing a reporter gene into the embryonic stem cells and separating stem cell lines due to the gene's effects (Eiges et al. 2001).
The human embryonic stem cells were first transfected with enhanced green fluorescence protein (EGFP), under the control of the murine Rex-1 promoter. The cells with EGFP demonstrated high levels of GFP expression when in the undifferentiated state and therefore showed high levels of fluorescence. As the cells differentiated, the levels of GFP expression decrease along with the degree of fluorescence. The undifferentiated cells were then isolated from the culture using a Fluorescence Activated Cell Sorter (FACS) (Eiges et al. 2001).
Furthermore, the pluripotent nature of the human embryonic stem cells was verified due to the results obtained using this new method. Since the fluorescence of the stem cells changed in some cases, it was clear that the human embryonic stem cells had differentiated. In addition, the ability of the stem cells to form embryoid bodies (EBs), Irregularly shaped clumps of cellular structures that contain tissue from all three of the
Others develop into muscle cells that can contract and also into nerve cells. Because they have the potential to become such a wide variety of specialized cells, embryonic stem cells are described as pluripotent. Plurip.0otency is one of two key features of embryonic stem cells. The second key feature of embryonic stem cells is their ability to divide or self renew for an indefinite period while retaining their undifferentiated, pluripotent state. As the cell mass grows, the population can be further expanded by growing in larger tissue culture flasks. An unlimited number of undifferentiated, pluripotent stem cells can be produced (Sumanas Inc. 2007).
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).
Differentiation of human embryonic stem cells into embryoid bodies compromising the three embryonic germ layers. Mol. Med. 6, 88–95. Hyun, J.C., Choon, S.L., Yoo, W.K., Jae, S.P., Sun, H.L, Hur, Jin., Eun, J.L., Tae, Y.R., In S.C., Sun-H.L., Youngsoo, K., Hyun, J.K., Young, B.P., et Hyo, S.K. (2010).Induction of pluripotent stem cells from adult somatic cells by protein-based reprogramming without genetic manipulation Blood journal, 113(9).
The ability to manipulate the stem cell corresponding to a specific organ/tissue remains important. A type of stem cell that can be manipulated is the embryonic stem cell. These stem cells descend from embryos aging from three to five days (Watt) (Driskell). During earlier stages, scientists describe embryonic stem cells as “blastocysts” which contain over one-hundred and fifty cells (Watt) (Driskell). They duplicate into more cells or transform to any cell located in the body (Watt) (Driskell). This “duplication” allows embryonic stem cells to regenerate and repair diseased tissues. Embryonic stem cells gain importance in cancer treatments—if doctors diagnose patients with leukemia, then during chemotherapy, the doctor can infuse embryonic stem cells into the body. Since the cells are young, they can repair the targeted cell, aiding cancer treatments and the patient. In addition, this technique is used with another type of embryonic stem cell called “pluripotent stem cells”. Pluripotent stem cells originate as inner mast cells (cells
These cells only carry a heterozygous splicing mutation (c.204+1G>A) in the NF1 genome and with the other allele remaining wildtype (Nf1+/-). (D-I) are immunofluorescence assay to characterize the pluripotency of Nf1+/- iPS cells using a panel makers for human embryonic stem cells.
Despite the new technological advances that bring promise to many medical treatments, few issues cause concern when implementing the research into clinical studies. Many ethical dilemmas slow the progression of research due to the variety of opinions influenced by moral beliefs. Resembling abortion, the process of fetal stem cell research includes destruction of the embryo five to seven days after conceived, in order to obtain the needed stem cells. Stem cells main function is to divide and regenerate into new more specially designed cells. In 1981, mice stem cells were obtained but over ten years later, researchers were able to extract stem cells from human embryos. It is believed the stem cells of a human embryo could better the treatments of birth defects, diseases such as Alzheimer’s, Parkinson’s, and cancer. The finding of these stem cells and their uses established a moral standstill within medicine and society.
In 1981, Martin Evans of the University of Cambridge revolutionized the field of medicine when he became the first person to identify embryonic stem cells. In a study that involved observing cultures of mouse embryos, Evans and his team discovered cells that behaved much differently than adult somatic cells. These cells, derived from the inner cell mass of mammalian blastocysts, had the incredible property of pluripotency. They were undifferentiated and able to grow indefinitely into cells of all three germ layers (Evans 1981), a completely unique ability that had been previously unheard
Human embryonic stem cells (ESCs) are pluripotent cells isolated from blastocysts, and are highly useful in studying human development (Itzkovitz-Eldor et al., 2000 p. 88). Although the National Institute of Health states that “it is not known if iPSCs and embryonic stem cells differ in clinically significant ways”, iPSCs are already being used to achieve the same results as ESCs in some applications without the use of embryos, removing the ethical concern associated with ESCs (National Institutes of Health, 2009). ESCs are capable of differentiating into all cell types, and can be used as a source of differentiated cells. In the report by Itskovitz-Eldor et al., they discuss the induced differentiation of ESCs in suspension into embryoid bodies, including the three embryonic germ layers. The authors state that “the ability to induce formation of human embryoid bodies that contain cells of neuronal, hematopoietic and cardiac origins will be useful in studying early human embryonic development” (Itzkovitz-Eldor et al., 2000 p. 88).
Embryonic Stem Cell Research holds the key to unlocking cures for many currently considered “incurable” diseases and even though Embryonic Stem Cell Research holds the potential to alleviate malicious disabilities, replacing harmful cancer cells and regrowing new tissue; with a little guidance from scientist. Embryonic Stem Cell Research is one of the biggest controversial topic centered primarily on the ethical implications of the destruction and use of the embryos during research. Since Stem Cells are the source of all tissues in our body, understanding how they develop and work will give scientists a better understanding in human biology, in health and sickness.
Embryonic stem cells are derived from embryos; however, most embryonic stem cells are generated and fertilized through in-vitro fertilization in a laboratory setting, not within a woman’s reproductive system. Embryonic cell generation is by no means efficient, although once the stem cells are created, it is able to yield millions of embryonic stem cells from that one cell (“Stem Cell Basics”).
“Adult stem cells may not be able to be manipulated to produce all cell types, which limits how adult stem cells can be used to treat diseases. Adult stem cells are also more likely to contain abnormalities due to environmental hazards, such as toxins, or from errors acquired by the cells during replication” (Mayo Clinic). Because of their extensive variety of uses and ability for manipulation, the embryonic stem cells from embryos are the most treasured stem cells in the research field. “These are pluripotent stem cells, meaning they can divide into more stem cells or can become any type of cell in the body. This versatility allows embryonic stem cells to be used to regenerate or repair diseased tissue and organs […]” (Mayo Clinic). Although stem cells are a marvelous discovery in the scientific world, a lot of question has surfaced due to the fact that stem cells must be taken so early on in the developmental stage of the embryo, and how they are taken. “The embryos being used in embryonic stem cell research come from eggs that were fertilized at in vitro fertilization clinics but never implanted in a woman's uterus. The stem cells are donated with informed consent from donors. The stem cells can live and grow in special solutions in test tubes or petri dishes in laboratories” (Mayo
Few recent scientific issues have stimulated so much media attention, public debate and government involvement as that of stem cell research. Stem cells offer people hope by promising to greatly extend the number and range of patients who could benefit from transplants, and to provide novel therapies to treat debilitating diseases such as diabetes, Parkinson?s, Huntington?s, heart disease and stroke, as well as accidental damage such as spinal cord injury. So why would anyone object to research in this area? The problem is simply that a particular type of stem cell, which potentially could provide many cell types for a wide range of therapeutic uses, is obtained from the very early embryo. To make matters even more
Stem cell research entails the development and use of human embryos and stem cells. After the embryonic stem cells are taken from aborted fetuses or fertilized eggs, scientists study the cells. Dating back 30 years, scientists began their first attempts of deriving embryonic stem cells from the embryos of a mouse. After examining details of the biology behind mouse stem cells, scientists moved onto the biology of human embryos. Through in-vitro fertilization, human embryos are grown in a laboratory rather than a female body. Similarly to stem cell research, cloning propagates the replication of identical cells and organisms.
Pluripotent stem cells are found in the early blastocyst, and can differentiate into different cell types such as neurons, cardiac muscle, or blood cells.
In recent years, there has been a lot more talk about stem cell research than ever before. The idea of stem cells arose in the 1960 's, with the first successful bone marrow transplant in 1968. Now, stem cell research is a widely known topic in biotechnology and shows a substantial amount of scientific promise. The future of stem cell research and the impact it could have follows with many questions on people 's minds, as well the simple curiosity of what stem cells are and how they can affect people both positively and negatively. There are quite a few areas of discussion about stem cells, and this essay addresses seven of the many questions concerning stem cell research.