Embryonic stem cells research paper
The blastocyst consists of two parts: an outer cell mass that becomes part of the placenta an inner cell mass that will develop into the human body The inner cell mass is where embryonic stem cells are found.
Critics, mostly from religious circles, argued that embryos constitute human beings, and wanted to prevent any research that involved destroying them.
Although the purpose of therapeutic cloning is not the creation of a new individual and it is unlikely that the viability of the constructed product is equivalent to that of an embryo derived from sexual reproduction, it is not correct to say that an embryo has not been created.
Bone marrow stem cells have been shown very recently to restore function to some extent in a mouse heart damaged by coronary ligation, an experiment that mimics the conditions of the human heart soon after infarction Orlic et al.
The discovery of Induced Pluripotent Stem Cell iPS in in mice and in in humans, represented the possibility of obtaining pluripotent stem cells without the need to destroy embryos. Some conditions cause damage to adult cells that would make any iPS cells derived from them uninformative.
This option is purported to be the optimal medical use of hES technology since the nuclear DNA of the cells is derived from a somatic cell of a patient to receive the transplant, reducing the chances of tissue rejection see Barrientos et al.
Should stem cell research utilizing embryonic tissue be conducted
In , for example, fertility doctors in Chicago started making ES-cell lines from embryos created through in vitro fertilization that had been found to have a genetic defect, and thus were rejected for fertility treatments. Although clinical restoration of function in a damaged organ is usually sought rather longer after the original injury than in these experiments, which were performed before scar tissue had formed, this approach will certainly be worth pursuing. After the publication in Science of the first major study on hESC on November 6, [ 3 ], only a few hESC papers were published over the next five years 42 in total. Keyvan Vakili, Anita M. This harvesting of stem cells can be expensive, but the advantages for future needs include: the stem cells are easily accessible less chance of transplanted tissue being rejected if it comes from the recipient's own body. Differences of opinion exist on the weight of these arguments how much protection does the embryo deserve? With the right stimulation, the cells can become blood cells, skin cells, and all the other cell types that a body needs. Researchers have already tried differentiating embryonic stem cells into these types of cells, so treatments are promising. Scopus is the most comprehensive library of peer-reviewed academic publications. The analysis investigates how the change in funding influenced the geographic location of scientific inquiry in the burgeoning field of hESC research. The technical difficulties and ethical controversies that arose from obtaining ES were insurmountable. Zhou Qi, a stem-cell biologist at the Chinese Academy of Sciences Institute of Zoology in Beijing, says that concerns that iPS cells would cause tumours inspired him to use ES cells for more than a dozen clinical trials he is orchestrating. Secondly, the simultaneous development of different research strategies is preferable, considering that research on hES cells will probably contribute to speeding up and optimising clinical applications of adult stem cells.
A second objection that could be raised in this context is that the creation of embryos through cloning for the isolation of stem cells could in the long term be used to justify the initiation of pregnancy from these embryos and their use simply as a vehicle for generating sufficient cells of the required type for transplantation; the pregnancy would be interrupted the moment the appropriate developmental stage was reached Lanza et al.
In only two clinical trials were reported using these cells. Introduction How important is public funding to science?
Stem cell research
The core of the problem is that here human embryos are created solely for instrumental use. And ES cells still have a supporting role. Thirdly, the significance of social and political debate requires clear and complete information that takes all consequences into account. But that trick was not easy to accomplish in primates. Keyvan Vakili, Anita M. This harvesting of stem cells can be expensive, but the advantages for future needs include: the stem cells are easily accessible less chance of transplanted tissue being rejected if it comes from the recipient's own body. One could use the same objection for example against surgery, which can equally be used for serious as well as trivial treatments. Bush restricted government funding to research on just a few existing ES-cell lines. But despite their sometimes rocky history, ES cells have proved their value repeatedly, and in some unpredictable ways, say many investigators. Although critics of this point of view could use our own argument that delay in the development of research cloning could, just as a moratorium on hES cell isolation and research, have negative consequences for patients, the evidence suggests that further optimization of the technology as such could take place in animals. Egli and Nissim Benvenisty at the Hebrew University of Jerusalem overturned long-held concepts of human biology when they derived ES-cell lines with just half the normal number of chromosomes 1.
Scientists have used MSCs to create new body tissues, such as bone, cartilage, and fat cells. Both perspectives have a different outlook on the question of whether or not there is a decisive moral distinction between research with spare IVF embryos on the one hand, and creating embryos for research on the other.
Why is stem cell research banned
Ruiz-Canela M 1. The difference is in the intention at fertilization, which, although a real difference, is relative. Here, however, an analogy can be made with recruiting healthy research subjects. The following year, he and Thomson achieved the same feat in human cells 10 , One crucial question is how far the pluripotent cells should be taken down the road towards maturity before transplanting them. Not only is the embryo used completely instrumentally in both cases, the moral status is also identical. A second category might be toxicology, more specifically research on possible toxic effects of new drugs on early embryonic cells which are often more sensitive than adult cells drug screening. He expects to start clinical trials within three years. Still, many say that human embryonic stem cells are now more relevant than ever. What, then, is the status of the individual cells from the ICM once isolated, and the embryonic stem cell lines derived from them? A handful of advances has changed that. Led by ophthalmologist Masayo Takahashi at the RIKEN Center for Developmental Biology, it aims to treat macular degeneration, but was halted in when investigators decided to simplify the procedure and use donor-derived, rather than patient-derived, stem cells. Feminist perspective From a feminist perspective, the creation of embryos for research should be evaluated critically in as far as it may require hormone treatment of a woman to obtain oocytes for research purposes: can this be morally justified when it requires unpleasant treatment of the donor with no benefit at all, or even a detrimental outcome, for her own state of health? Thirdly, the significance of social and political debate requires clear and complete information that takes all consequences into account. The efficiency of establishing embryonic stem cell lines from nuclear transfer embryos is currently unknown, but expected to be lower than from IVF embryos.
based on 102 review