|
|
|
Can embryo destruction for research be justified
WILLIAM Shakespeare said: “There is nothing either good or bad but thinking makes it so.”
The identification, isolation and culturing of stem cells can be regarded as one of the landmark achievements of science, mainly biotechnology of this century, particularly in biomedicine. Their use in research can revolutionize the way we treat and diagnose diseases. However, their use in research encompasses a great number of ethical concerns which are of that critical nature that without addressing them no scientist is allowed to go ahead. In order to explore and understand these issues one must consider what stem cells are, what are the potential benefits associated with them, how they are used in research and what ethical issues arises?
Stem cells provides the basis of life and serve as starting material from which all kinds of cells of human body can develop. Human development begins when a sperm fertilizes an egg and results in formation of zygote — a single cell that has potential to develop in to an entire organism. Stem cells are of three types: totiopotent, pluripotent and multipotent. In the first hours after fertilization zygote divides in to identical totiopotent cells (stem cells having potential to develop in to any cell type). About four days after fertilization and after numerous cycles of various cell divisions, these totiopotent cells begin to specialize, resulting in to hollow sphere of cells called blastocyst.
The blastocyst consists of an outer layer of cells which will give rise to placenta and other supporting tissues needed for fetal development in uterus, and a cluster of cells called inner cell mass inside the hollow sphere which are pluripotent stem cells — can develop in to many types of cells but not all types that are necessary for fetal development. These pluripotent stem cells undergo further specialization and results in multipotent stem cells that have ability to differentiate in to many cell types with a particular function such as skin stem cells which give ruse to various types of skin cells.
Stem cells used in research can be of two origins either embryonic or adult stem cells. Embryonic stem cells are those that are harvested from embryo and adult stem cells are cultured from bone marrow, brain, gut and other tissues of the body.
The temptations offered in use of stem cell for research purposes are:
— To understand basic human development as to what are the series of complex events that takes place during development?
— To identify the factors that are involved in cellular decision making processes which results in cell specialization, and recognize the key factors that causes selective “turning off” or “turning on” of genes.
— To generate cells and tissues for cell-therapies and tissue-transplantation to be used for diseases such as Alzheimer’s disease, Parkinson’s disease, rheumatoid arthritis, diabetes, etc.
— To study birth defects and infertility.
— To discover new drugs and their safety testing prior to human use avoiding animal and human trials.
Some people believe that harvesting stem cells from embryo destroys human life because it kills the embryo from which they are taken. The basic moral problem with this destructive embryonic stem cell research is that, whether we are going to alleviate the sufferings of pre-existing at the expense of those who have just started their life? Can this act be justified within the framework constructed on the basis of principles given in different disciplines and human right acts dealing with the value of human life? Whatever the way justification is given, it will certainly involve:
a. What exactly the status embryo has and what is wrong, if any, with its destruction?
b. If embryonic stem cell research is to be restricted (or should be restricted) then what could be the possible alternatives with associated harms and benefits, if any?
Embryo is a mass of reproductive cells and is believed to have life uncontroversially. The leading status that an embryo can have in light of different views is that of a person. Beside physical differences between a person and an embryo, it is still considered as a person by some people.
They argue that the respect and moral value given to a person should also be given to an embryo, although the characteristics attributed to personhood, such as thinking abilities, arguing abilities, emotional feelings, decision making power etc are not possessed by an embryo. As embryo particularly the early stage embryo (preimplantation embryo - the first 14 days after an egg is fertilized, the group of cells is known as preimplantation embryo) involved in research won’t show any of these properties therefore the dignity and respect offered to an individual is not necessarily deserved by the embryo.
Here some people argue that embryo although not having personhood characters right at beginning but, will have in future if they are allowed to develop, therefore according to them embryo can be considered as “potential person.” But the chances of developing of an embryo are very much context dependent. In nature, the majority of them pass from the body of women without ever attaching to women’s uterus. There is also a high rate of foetal loss (up to 73 per cent) in embryos created by ART (assisted reproductive treatment), such as IVF (in vitro fertilization — union of eggs and sperm out of body under conditions that result in embryo that is then planted in woman’s uterus).
Currently there are about one million those early embryos resulting from such techniques left to be discarded. Some theists consider embryo as divine creation and emphasized not to harm them as we are not their creators and therefore, have no right to destroy them. Some consider embryo as human life with intrinsic value. To evaluate this one must ascertain what life is and what intrinsic value it attributes.
A leading Anglo-American philosopher Ronald Dworkin attributes intrinsic value of life to its different stages. According to him, “a single human life has value no matter in what form or shape, because of the complex creative investment it represents and because of our wonders at the divine or evolutionary processes that produce new lines from old ones, at the processes of nation and community and language through which a human being will come to absorb and continue hundreds of generation of cultures and form of human life and value, and, finally, when mental life has begun and flourishes, at the process of internal personal creation and judgment by which a person will make and remake himself, a mysterious, inescapable process in which we each participate, and which is therefore the most powerful and inevitable source of empathy and communication we have with every other creature who faces the same frightening challenge.”
He considered that loss of life at early stages or later stages of life is not of that much importance as in young age when a person is full of energy and enthusiasm to achieve something in life and striving for that. So the moral respect and value an embryo deserves is not of extent, that a person at later stages of life. In Jewish traditions an embryo less than 40 days is considered unformed and not a fetus, catholic principles places the life at one’s own conception. Based on teachings of the Holy Prophet (peace be upon him), some religious scholars belonging to different school of thoughts, divides the pregnancy in two stages:
— Pre-ensoulment stage: before four months (120 days) of gestation;
— Post-ensoulment stage: after four months of gestation. Embryo eradication at post-ensoulment stage is considered as a sin (most of Sunni scholars) and in pre-ensoulment stage as well (most Shia scholars). The destruction of early stage embryo must therefore be justified by the possible benefits offered to other human beings that must be supportive enough for eradication.
Alternatives to embryonic stem cell research are:
— Adult stem cells taken from bone-marrow, gut or from any other tissue can be used for research because they have the capability to differentiate into different cell-types to a limited extent. But they are not shown to be as pluripotent as embryonic stem cells are. Their use offers less temptation in gene-therapy and regenerative medicine than embryonic stem cells. However, the use avoids the ethical debate concerning embryo destruction as well as they are more immunologically compatible with the person from whom the stem cells are derived.
Tissues produced from embryonic stem cells have chances of immunorejection because they are of the type of embryo from which they are derived.
The excess of embryos produced from ART such as IVF stored at -80°C to protect them from expiration and destroy by natural process can be used for research because they have to be put in to end in any way. Some philosophers also consider that as an unethical act because they think there is a moral distinction between killing something with deliberation and failing to prevent something from destruction. But as these surplus embryos have to be discarded then their use in research can be justified in terms of their intended use for societal benefits and to help those who are suffering, according to some ethicists.
Some argue that apart from surplus embryos, these techniques can be used to create embryo specifically for research. In this case the main objection raised is, to commodify the embryo which is a strict moral disrespect of embryo status, whatever it may be.
Another societal concern with embryonic stem cell research is that allowing embryo devastation desensitizes the society in general, about the value of life and most of the people then get involved in practices such as late term abortion, embryo preservation, etc.
Here some people argue that allowing embryo creation for research also serves to attain symbolic respect from the community towards the value of life as they condemned this. As the philosopher John A. Robertson say, “In taking such a stance, persons define or constitute themselves as highly protective of human life.”
A major breakthrough comes from the researchers at the Scripps Research institute, they found that a small synthetic molecule called reversine can turn back the differentiated cells back to their undifferentiated state, and this time with a potential to differentiate along any lineage, for example muscle cells to immature cells which can then form any cell such as bone or cartilage etc. “This has the potential to make stem cell research more practical”, researcher Sheng Ding said, “this will allow you to drive stem like cells from your own mature cells, avoiding the technical and ethical issues associated with embryonic stem cells.”
Whether embryonic stem cell research is allowed to perform or not, it depends greatly on one’s understanding about life, one’s perception of its value, knowledge, beliefs and the way one takes life.
Jerrold Nadler, a Democratic Republican once said: “We must not say to millions of sick or injured human being go ahead and die and stay paralyzed because we believe... a clump of cells is more important than you are.”
Adult stem cells hold a tremendous potential for disabled but still the importance of embryonic stem cells cannot be overruled. A strategy with societal consensus must be adopted to maximize the potential benefits of stem cells yet not overwhelming the status of embryo.
The writer is an M.Sc student majoring in Biotechnology from the University of Karachi
|
|
|
|
