Abstract
Embrionic stem cells research, as opposed to hematopoietic stem cells research, has always stirred up many controversies of ethical nature that have projected their effects in the specialized doctrine of the domain of medical bioethics and law. Some of these controversies have been transposed at the legislative level (both by international normative acts and by the national laws of the states) while others are not yet de object of consensus. All that is not transposed by law remains in the exclusive sphere of ethics, so the ethical discussion in embryonic stem cell research is not only relevant for today's modern medicine but also of the utmost importance for a category of specialists in various research fields.
TopMedical Aspects Of Embryonic Stem Cell Research
Research on embryonic stem cells is a technology that has emerged as a consequence of human assisted reproductive techniques and has evolved in close connection with these techniques. Without the possibility of creating embryos in vitro, there would have been no real chance for a large-scale study of the potential of embryonic stem cells (Huidu, 2017: 196).
There are four types of stem cells: totipotent, pluripotent, multipotent and unipotent. Totipotent cells can differentiate to become any type of cell in the body, but also have the ability to each give birth to another human being (these are the 4 cells from which the human embryo is formed in it’s blastomer stage); pluripotent cells - which are the object of stem cell research - have the ability to specialize and transformi into any type of body tissue or body organ, but lack the function of giving birth to a new organism (these are the cells occurring after the first 4 days of fertilization); multipotential cells - those that can give rise to other types of cells, but are limited both in their differentiation capacity, as well as in type or numbers (e.g.: neural cells, hematopoietic cells); unipotential cells are those already specialized to form certain tissues (of the skin, liver, intestinal mucosa etc.) and which can cause only one type of cells (Buțureanu & Lupșan, 2001: 58-59; Miehl, 2003: 25-26; Smith, Sindhu, & Meissner, 2016; Stem Cells, n.d.). The structural and functional differentiation of unipotential cells during embryonic development (also called cytodifferentiation) is an irreversible process (Gavrilă & Iftime, 2006: 144). Fully differentiated mature cell cultures are limited in their growth by the presence of telomeres - existing formations at the end of the chromosomes, which shorten every time they replicate duiring the cell division process, eventually leading to death of the cells, a phenomenon that has been identified as one of the causes of aging (Aviv & Shay, 2018). Inside embryonic stem cells, there is an enzyme responsible for preventing telomere degeneration, which makes it possible for multipotent cells, after being placed in the appropriate laboratory regulated environment, to multiply continuously, withought ever differentiating (Gavrilă & Iftime, 2006).
Key Terms in this Chapter
Status of the Human Embryo: A sum of characteristics and rights recognized to the human embryo, wether in vitro or in utero, by reference to its developmental stages and its genetic features specific to the human species, which gives it a distinct positioning (regardless of its prenatal developmental stage) in relation to a fully developed human being in legal, biological, ethical, religious, or philosophical systems;
Excess (Supranumerary, Left-Over) Embryos: Embryos not implanted in the uterus of a woman after an IVF procedure in order to avoid the risks associated with multifetal pregnancies, remaining as a result of the medical process of ovarian hyperstimulation, followed by the collection of an increased number of eggs, then in vitro fertilization, the selection and transfer in utero only of those embryos considered of best quality (more viable) in order to obtain a successful pregnancy and ultimately the birt of a child.
Embryonic Stem Cells: The cells that form the human embryo, not yet differentiated morphologically, structurally, or functionally, or only partially differentiated, self-replicating, and capable, under the influence of environmental factors, to specialize functionally to become any cell in the body or even a new organism (totipotent), any cell in the body, but not a new organism (pluripotent), certain cell lines limited in number (multipotent), or only a certain cell line (unipotent).
Stem Cells Research: A field of medical research that uses the potential of stem cells to specialize functionally under the impetus of environmental factors in order to find treatments for disease amelioration or eradication, replacement of diseased organs in the body, testing of experimental drugs, identification of causality of diseases, etc.
Human Dignity: Abstract term indicating a set of qualities, reactions, or behaviors of the human being, in its interaction with other members of the species or with the environment, and involving the way in which that person assesses the potentially injurious consequences of dangerous, offensive, denigrating, or discriminatory situations.
Pro-Life Theories: Legal, bioethical, philosophical, or religious doctrines claiming that human embryos are human beings starting with the stage when sperm fertilizes the egg (zygote stage), which requires respect for their right to life and their biological integrity and the avoidance of any action that would destroy or harm them in any way.