SO WHAT ARE STEM CELLS?
These are a very special family of cells. When most other cells divide, the daughter cells look and act exactly like their parents. For example, blood cells will produce blood cells only, but in the case of stem cells, they can become many different types. Do you know an embryo grows from a single fertilized egg into a fetus with trillions of specialized cells? These special cells make up various different kinds of tissues that function very differently, including those in the brain, skin, muscle and other organs and luckily further in life, stem cells also can replace worn-out or damaged cells — including red blood cells. And thus these special attributes of stem cells make them very exciting to scientists all over the world.
One day, we hope to use stem cells to repair or replace many different kinds of tissues, whether injured in accidents or damaged by diseases. Such stem cell therapy would allow the body to heal itself. Scientists have found a way to put specialized cells to work repairing the damage, too.
Together, these cell-based therapies might one day make permanent disabilities a thing of the past. Although more versatile, embryonic stem cells are both difficult to obtain and controversial. That’s because harvesting them requires destroying an embryo!! And here comes ethical, religious and moral values.
It already has generated heated debate regarding the boundaries of scientific research and it is widely expected that it should not cross and conflict with religious and moral values.
We will also ponder over different religious views on this discussion, basically, I will limit it to Hinduism, Christianity, and Islam, although other religions and sects have view as well.
NOW IT IS TIME TO INTRODUCE YOU TO THESE SPECIAL FAMILY
Stems cells are simply the “original” cells from which different kinds of other cells arise and that makes the human body develop. Have you heard about bone marrow? Exactly the blood stem cells reside here, they divide here over and over again. Some of the new cells remain stem cells, others form red blood cells. Still, others morph into any of the five types of blood cells that fight infections.
WHAT HAPPENS AFTER AN EGG IS FERTILIZED?
Initially, it divides into two and these two cells split again, to become four cells, and so on. In the first few days of this embryo’s development, each of its cells is identical to all the others. Still each cell has the ability to develop into any specialized cell type. When the human embryo marks three to five days old, its cells start to realize their potential. They specialize. Some will develop into lung cells. Others will form muscle or bone cells — or maybe the cells lining the stomach. Once cells specialize and shapes itself, their “many possibilities” suddenly become limited.
When the baby is born, almost all of a baby’s cells will have specialized. Each cell type will have its own distinctive shape and function. For example, muscle cells will be long and able to contract, or shorten. Red blood cells will be small and plate-shaped so they can slip through blood vessels with ease.
Hidden among all of these specialized cells are a handful of adult stem cells. ( even newborns have “adult” stem cells.) These cells are unlike embryonic stem cells and adult stem cells cannot transform into any and every cell type. However, adult stem cells can replace several different types of specialized cells as they wear out. One type of adult stem cell is found in your marrow, making new blood cells. More types are found in other tissues, including the brain, heart, and gut.
Among all these cells the embryonic type is the most useful. Adult stem cells just aren’t as flexible. The adult type also is relatively rare and can be difficult to separate from the tissues in which it is found.
SO HOW IT IS DONE?
Most ongoing research has been utilizing embryonic stem cells (ESC), which are derived from the embryonic inner cell mass and kept growing in tissue culture. Most studies were made on murine (mice) ESC, but there also has been great demand for human ESC because they are believed to be much more promising in the search for cures of human disease. Human embryos have been created by in vitro fertilization (IVF)[here fertilization is done in the lab through couples concerned] specifically for stem cell research. Attempts also have been made to use spontaneously aborted fetuses but mostly these cells fail to grow in culture. Also, cloned embryos have been developed through the procedure of somatic cell nuclear transfer, which is sometimes called therapeutic cloning.
At the University of Nebraska medical centre in Omaha, Iqbal Ahmad is working on using stem cells to restore sight to the blind. A neuroscientist is someone who studies the brain and nervous system — Ahmad been focusing on people who lost sight when nerve cells in the eye’s retina died from a disease called glaucoma(a condition of increased pressure within the eyeball, causing a gradual loss of sight). The retina is located inside the back of the eye, which converts incoming light into electrical signals that are then sent to the brain. Ahmad is focusing and trying on how to replace dead retina cells with new ones formed from induced pluripotent stem cells. The neuroscientist starts by removing adult stem cells from the cornea( the clear tissue that covers the front of the eye). These stem cells normally replace cells lost through the wear and tear of blinking. They cannot become nerve cells — at least not on their own. Ahmad, however, can transform these cells into induced pluripotent stem cells. Then, with prodding, he turns them into nerve cells. To make the transformation, Ahmad places the cornea cells on one side of a petri dish. He then places embryonic stem cells on the other side. A meshlike membrane separates the two types of cells so they can’t mix. But even though they can’t touch, they do communicate. Cells constantly send out chemical signals to which other cells respond. When the embryonic stem cells “speak,” the eye cells “listen.” Their chemical messages persuade the eye cells to turn off the genes that tell them to be cornea cells. Over time, the eye cells become stem cells that can give rise to different types of cells, including nerve cells. Then Ahmad’s team implanted the nerve cells into the eyes of laboratory mice and rats, they migrated to the retina. There, they began replacing the nerve cells that had died from glaucoma. One day, the same procedure may restore vision to people who have lost their sight.
The benefits of stem cells have been realized hence many researches are going on, the best known of which is the successful treatment of leukemia(it’s cancer of blood cells caused by a rise in the number of blood cells in body) and many other hematologic disorders by bone marrow transplants and, more recently, by using umbilical cord blood stem cells. However, the real promise of stem cell research is the potential development of a new field of “regenerative medicine” which aims at growing tailor-made human tissues or organs to be used to colonize or to replace damaged tissues/organs to recover their lost function. Progenitor cells have been developed that can be made to differentiate into myocardial cells, neurons, and pancreatic as well as other types of cells, these cells can potentially be used to treat Parkinson’s disease, Alzheimer’s disease, and patients with spinal cord injuries. It is speculated that they will also be used in the treatment of type 1 diabetes, myocardial infarction as well as other conditions.
Religion and stem cell research
Religion and religious values play an important role. Therefore, a discussion of stem cell research and its ethical implications cannot be complete without discussing the religious viewpoints.
They believe that the human embryo is an individual from the moment of fertilization and that it has the right to its own life. They further believe that every intervention not in favour of the embryo is a violation of its right and that no good end justifies the destruction of an embryo. On the other hand, less conservative protestant churches teach that the embryo has a potential human status, but the life of the embryo has to be weighed against the possible benefit that may result from scientific research. They believe that while the life of an embryo is sacred from the time of fertilization, embryo research may be permitted prior to the primitive streak stage.
Islam is usually defined as submission to God will. The important consideration in the topic under discussion is when life starts. It is generally agreed that ensoulment, differentiates biological life, which starts at the time of fertilization, from human life. There is a difference of opinion between scholars as to whether ensoulment occurs at 40 or 120 days. Narrated on the authority all scholars agree that embryonic life is entitled to respect even before ensoulment but becomes more so after it occurs. It is permissible to acquire, grow and use stem cells for therapy or scientific research as long as the cells’ sources are permissible.
Examples of permissible sources are adults who consent as long as it does not inflict harm on them, children whose guardians consent for a legal benefit without inflicting harm on the children, placenta or umbilical cord blood with the permission of the parents, spontaneously aborted embryos or those aborted for a legally acceptable cause and with the permission of the parents, and excess fertilized eggs produced during the course of IVF and donated by the parents with assurance that they are not to be used to produce an illegal pregnancy.
Hinduism believes in the sacredness of human life like all other religion and it is the moral duty not to harm a human being. While the very practice of stem cell itself is seen as a good act in view of its overriding aim to seek cures for diseases, the nature of research entailing the destruction of human embryos has elicited ethical controversies. Ethical viewpoints of Buddhist and Hindu leaders, it appears that the donation of leftover IVF embryos for research that may lead to saving lives has been accepted. Firstly, Hindu and Buddhist ethics support the efforts of saving human lives. The good intention that should drive stem cell research and knowledge seeking activities are held as noble and at high esteem by both religions and traditions. Secondly, the concept of donation is employed when arguing the permissibility of using surplus embryos. They expand the arguments that in special circumstances allow abortion. The mother’s endangered life must be given greater weight than that of the fetus.
POINT OF VIEW
No doubt there is a promising benefits of stem cell research in treatment of diseases like leukemia and many other hematologic disorders through bone marrow transplant and umbilical cord blood stem cells. There is absolutely no arguments in ability to treat serious diseases which is good deed but it must be remember that to achieve a desired good thing at times, are not morally and ethically justifiable.