There are stem cells in various tissues (such as bone marrow, blood, liver) in children and adults.
However, the amount is small and we do not know yet which tissues are able to differentiate. Recent research has shown that stem cells taken from the marrow of individuals with heart problems have been able to replenish their heart muscle, which opens up fantastic prospects for treatment for people with heart problems.
But the biggest limitation of the technique, of autotransplantation is that it would not be suitable for people with genetic diseases. It is important to remember that genetic diseases affect 3-4% of children who are born. That is, more than five million Brazilians for a current population of 170 million people. It is true that not all genetic diseases could be treated with stem cells, but if we think only of degenerative neuromuscular diseases, which affect one in every thousand people, we are talking about almost two hundred thousand people.
Umbilical cord and placenta
Recent research has shown that cord blood and placenta are rich in stem cells. However, we also do not know yet what is the potential for differentiation of these cells in different tissues. If cord blood stem cell research yields the expected results, that is, if they are truly capable of regenerating tissues or organs, this is certainly fantastic news because it would not involve ethical issues. We would then have to solve the compatibility problem between the donor and recipient cord stem cells. This will require the creation of public cordon banks as urgently as blood banks. This is because it is known that the more string samples in a bank, the greater the chance of finding a matching one.
Recent experience has shown that cord blood is the best material to replace the cord in cases of leukemia. Therefore, the creation of cord banks is a priority that is already justified only for the treatment of blood diseases, even before we confirm the results of other research.
If cord stem cells have the desired potentiality, the alternative would be to use embryonic stem cells obtained from unused embryos that are discarded in fertilization clinics. Opponents of using embryonic cells for therapeutic purposes argue that this could lead to a trade in eggs or that there would be destruction of "human embryos" and it is unethical to destroy one life to save another.
Text adapted from Zatz, Mayana. "Cloning and stem cells". Cienc. Cult., jun. 2004, vol. 56, no. 3, pp. 23-27, ISSN 0009-6725.
Victory for Science: Embryonic Stem Cell Approved in Research Approved
The Supreme Court (STF) approved on May 29, 2008 the research with embryonic stem cells in the country. The Supreme Court rejected a direct action of unconstitutionality against article 5 article of the Biosafety Law that allows the use, in research, of these fertilized cells. in vitro and unused. Under the rule, only embryos that have been frozen for three years or more may be used, subject to the couple's consent. The article also vetoes the commercialization of biological material.