id Stem Cells: quick ideas about Stem Cells. What are they? Where do you get them from? Medical use. Ethical issues. Therapeutical Cloning.
células madre células mãe(por) cellules souches(fr)

1. What are Stem Cells? They are cells that are pluripotential or multipotential. This means that they can be the origin of a variety of tissues (muscles, nerves, osseous, etc.). Totipotential stem cells can generate a complete living being, these on the other hand, are only a portion. For example, in the healing of a wound, there is a generation of new tissues where these cells intervene.

2. Where can we find Stem Cells? We can sum-up these places in three groups:

  • In the Embryo.- There are two possibilities:
    - In a embryo that is 5 days (with 150-200 cells). Most are Multipotential.
    - In some organs of the embryo that are more developed: Liver, Brain, bone marrow…
  • In the blood of the umbilical cord.
  • In some tissues of a grown adult male, for example, in the peripheral blood. These are called Adult Stem Cells.
  • Reprogramming normal cells into Stem cells has also been accomplished.

3. What utility can we get from Stem Cells? The objective is to get these cells to create tissues that can replace injuries due to different illnesses (Parkinson’s, Alzheimer, sclerosis…). The benefit is that if they come from the same patient they would not face rejection.

4. Has anything been achieved? There have been several successful interventions on patients with Adult Stem Cells. On the other hand, embryonic stem cells have led to problems such as tumours or cancer as they tend to generate various tissues, whilst adult ones, after inducing them, they are limited to reproduce the tissues which were planned. Due to this, the correct line of investigation should be in Adult Stem Cells. On the other hand, embryonic stem cells present serious ethical problems.

5. What ethical problems? There are several cases:

  • The use of embryonic stem cells is a serious error as to obtain them you have to murder an embryo.
  • The Adult Stem Cells can be used without any ethical problems.
  • It is not a problem to obtain stem cells from the umbilical cord after birth. But there is a possibility that this will cause tumours like embryonic stem cells.
  • More reprehensible would be to use therapeutic cloning.
6. What is Therapeutic Cloning? The so-called therapeutic cloning takes an oocyte from any woman and through cloning it is put in the nucleus of another individual in order to obtain an embryo that is the same as the individual. Then the cloned embryo is killed obtaining stem cells for the other.