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When does life begin?

Brazil's Federal Supreme Court had 22 experts convene before voting on a motion against the use of embryo stem cells

Reproduction from the book "Leonardo da Vinci – On the human body"From Brasília

In the first public hearing in its history, the Brazil’s Federal Supreme Court asked 22 scientists when life begins. This was an initiative of Carlos Ayres Britto, reporting on an action deemed  unconstitutional and filed by former federal prosecutor Claudio Fonteles, arguing  that the Biosecurity Law passed in March 2005, authorizing the use for research purposes of embryos in the blastocyst stage (i.e., up to five days old) goes against article 5 of the Federal Constitution, which guarantees the right to life. The hearing, he explained, was of an “instructive” nature and was meant to provide arguments for the preparation of a report to be presented to the other justices prior to voting on the issue in a plenary session of that court of law, probably in late June. “We want to honor organized civil society, which will hereby contribute to a ruling that will have repercussions on people’s lives, given that the Supreme Court is the one where destinies are set”, states Ayres Britto.

Four of the eleven justices attended this hearing: Joaquim Barbosa, Gilmar Mendes and Chief Justice Ellen Gracie, besides Ayres Britto. Justice Ricardo Lewandowski followed the debate via the Internet. “The act delivering a sentence is an exercise in humility”, justified the Chief Justice. The guests were organized into two groups: group A, so named by the justice, consisted of scientists in favor of using embryo stem cells in research, provided the cells come from embryos fertilized in vitro and kept frozen at assisted reproduction clinics. Group B, on the other hand, consisted of those who were against the legal authorization.

Group A opened the morning session of three and a half hours, followed by group B, which opened the four-hour long afternoon session before Group A. Both were closely followed by an audience of roughly 300 people, including Father Odilo Scherer, secretary-general to the National Conference of Bishops of Brazil (CNBB – Conferência Nacional de Bispos do Brasil). The two groups were confronting each other for the second time. The first debate took place in 2004 and early 2005, when the House of Representatives and the Senate were in the process of voting on  the Biosecurity Law. However, at the Federal Supreme Court, the debate rules were clear and strict. “This is not a contradictory debate. Each group listens to the other group. We need you in  to reach a technical and legal ruling”, insisted the reporting justice.

In the pro-use group, three people were members of the Brazilian Academy of Science (Academia Brasileira de Ciências – ABC), an entity that has already advocated using embryo stem cells in research. Geneticist Mayana Zats, director of the Human Genome Studies Center and a head professor at the University of São Paulo (USP) pondered that science was not yet able to provide a definitive response to the justice’s query, but suggested that the beginnings of life could perhaps be defined by contraposition to the definition of death, which Brazilian legislation takes as being the moment when all brain activity ceases, after which organ donation is authorized. “The frozen embryo has no brain activity and can donate cells”, she argued.

Patricia Pranke, from the Federal University of Rio Grande do Sul and head of the Stem Cell Research Institute, stated that only a small number of embryos fertilized in vitro is “symmetrical and devoid of fragmentation” and can be transferred to the mother’s womb. “Even so, they only have a 25% chance of being generated. That is why one implants four to five embryos’, she stressed. The other embryos suffer from fragmentation and their chances of growing range from 0.8% to 6%, with the risk of fetus malformations. “If they are frozen, this percentage drops further and the risk becomes greater. If these embryos are not viable, why not donate them to research before freezing them?” challenges Patricia.

According to Stevens Kastrup Rehen, head of the Brazilian Neurosciences and Behavior Society, the admission that life begins at the moment of fertilization presupposes that the uterus is “the essence” without which the fertilized egg cannot develop. “And we are talking about cells that had no contact with the maternal womb because fertilization was conducted in vitro”, he commented.

Conflict vs. confrontation
Contrary to the arguments in Congress, the representatives of the group that was against using embryo stem cells in research did not rely on religious arguments at any time, although many of them had been invited to the debate by the National Conference of Bishops of Brazil (CNBB). The strategy was to rely on philosophical arguments or emphasize that the prospects for research based on adult stem cells, besides having proven  results in the treatment of certain diseases, had already been shown to have sufficient “plasticity” to turn into tissues and muscles, thereby making it unnecessary to use frozen embryos.

Lenise Aparecida Martins, assistant professor of the Cellular Biology Department at the University of Brasilia referred to the results of research into the human genome, recalling that, from the moment of fertilization onward, the genetic characteristics are set. “It’s already possible to know whether the person would be tall or short, blond or dark haired, or even whether the person will suffer from genetic diseases”, she states. She also showed a slide with a stack of CDs: “When one looks at a stack of CDs, you don’t know what’s recorded, but you know it’s there.”

Biologist Claudia Batista, a professor at the Federal University of Rio de Janeiro (UFRJ), advocated the idea that human life is “progressive and continuous”. “From the egg to the adult, there are changes, but the identity remains the same. The zygote is the first homo sapiens cell and the one that triggers the intrinsic development program of that being.” Moreover, Lilian Piñero Eça, a doctor of molecular biology and coordinator of the course “Adult Stem Cells” of the University Studies Center of Sagrado Coração University, stated that as from the moment of fertilization, the embryo engages in a chemical dialogue with the 75 trillion cells of the mother’s body.”

As for Alice Teixeira Ferreira, professor of biophysics at the Federal University of São Paulo (Unifesp), and Marcelo Paulo Vaccari, plastic surgeon and vice-president of the Stem Cell Research Institute of the University of Santa Catarina (USC), they preferred to advocate using adult steam cells in research. “It is said that embryo cells, contrary to adult ones, can differentiate themselves into any tissue. That is not true. We have evidence indicating that adult cells may also have these characteristics. That has already been proven in animals”, guaranteed Alice. “We have 72 adult stem cell applications with positive results, vs. zero with embryo stem cells”, Vaccari counted.

June ruling
This was not the only moment in which a quiet murmur rippled through the audience, contained only by the rules of conduct established by Ayres Britto. The justice occasionally interrupted his note-taking to remind the presenters that they should stick to scientific, philosophical or anthropological arguments, without venturing into the legal field, this being the Supreme Court’s territory, thereby avoiding any provocations. “We cannot confuse conflict, which is healthy, with confrontation, which is a battlefield”, he warned.

In was in this atmosphere that biophysicists Lygia da Veiga Pereira, doctor of human genetics and director of the USP Molecular Genetics Laboratory resumed the argument in favor of using embryo stem cells. She recalled that the research into adult stem cells extends back to the 50’s, but is limited essentially to bone marrow transplants, with no effect on the treatment of other diseases. “Any other application falls within the scope of research and the “plasticity” of these cells is still being tested”, she emphasized. Embryo stem cell research is more recent, dating from the 90’s. “Today, we can already differentiate them into skin, nervous system and muscle in research with mice. Our effort consists of adapting the animal models to the human model.” The research has not yet reached the clinical trial stage for reasons of security. “If we are able to conduct research, we will be able to get to this”, she stressed.

Science lesson
Cláudio Fonteles, the author of the  unconstitutionality action that gave rise to the hearing, closely monitored the almost eight hours of debate. “We were given a science lesson”, he commemorated. “Today, the myth that I did this because I’m a Roman Catholic fell by the wayside. All my work was based on science. I advocate that human life starts with fertilization.”

For Justice Ayres Britto, “from the technical point of view”, the scientists’ contribution was decisive. “We can now formulate an operational notion about life in order to make the Constitution more effective. This is a ramified, multidisciplinary subject”, he states in a well attended interview  granted during a break between two sessions. If the decision of the “Court that set destinies”, in his words, is favorable to what is already established in the Biosecurity Law, embryo stem cell research will continue on its course. If the decision is against this, meaning that the justices concluded that life begins at the moment of fertilization and must be protected as from this instant, then the research will be suspended. However, the impact of this ruling will extend far beyond this and will have repercussions in areas such as health. “If the  action is upheld as being unconstitutional,  it will be necessary to promptly review the law that authorizes assisted fertilization”, emphasized  Luiz Eugênio Araújo de Mello, dean of the undergraduate school of the Federal University of São Paulo (Unifesp) and vice-president of the Federation of Experimental Biology Societies.