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Stem cell research has a high media profile, but how long has it actually been with us? When were the first embryonic stem cells cultured in the laboratory by scientists in the USA?
The first embyonic stem cells were cultured in the laboratory 1998. Late in this year two teams of American scientists, one led by Dr James Thomson at Wisconsin and the other by John Gearhart in Baltimore, announced that they had cultured embryonic stem cells and kept them alive for some time.
At which stage of embryonic development are the stem cells usually removed?
Stem cells are usually removed at between 4 to 6 days, when the embryo is forming a hollow ball of cells.
What is the source of the most commonly used adult stem cell?
The most commonly used adult stem cells come from bone marrow - adult stem cells in the form of bone marrow transplants have been given to patients suffering from leukaemia and diseases of the immune system for many years.
Scientists and doctors hope that stem cell therapy may be able to cure or prevent many different diseases. Which of the following conditions is stem cell therapy unlikely to be able to help?
Stem cells are unlikely to be able to cure pneumonia because it is an infectious disease.
What term is used for the process where an embryo is created using DNA from a patient and an empty ovum, and embryonic stem cells are then removed from the embryo?
When an embryo is created using DNA from a patient and an empty ovum, and embryonic stem cells are then removed from the embryo, the process is called therapeutic stem cell cloning.
What is the term used to describe undifferentiated embryonic cells which are capable of differentiating into any of the cell types needed in the adult body?
Undifferentiated embryonic cells which are capable of differentiating into any of the cell types in the adult body are described as totipotent. Multipotent cells can only differentiate into a limited range of cell types, eg adult stem cells; pluripotent cells can differentiate into most types of body cells, eg the embryonic stem cells used experimentally; potent means "sexually fertile and active".
Which of the following statements is NOT an advantage of using embryonic stem cells rather than adult stem cells experimentally and for treatments?
There are a number of ethical issues linked to the use of embryonic stem cells which have given rise to many legal problems. Being pluripotent is an advantage as more different cell types can be formed, techniques for culturing embryonic stem cells in the lab are now well established, and they are more readily available than many types of adult stem cells.
In therapeutic stem cell cloning the embryonic stem cells which result have identical DNA to the patient donor who needs new tissues. What benefit would this technique have over the more common method of culturing embryonic stem cells?
Therapeutic stem cell cloning is if anything slower than culturing embryonic stem cells as there are more stages. It involves an early cloned human embryo which is the source of the embryonic stem cells, and because of this some people find it no more acceptable than using embryonic stem cells from donated embryos.