.New Stem Cell Method Avoids Destroying Embryos
Biologists have developed a technique for establishing colonies of human embryonic stem cells without destroying embryos, a method that, if confirmed in other laboratories, would seem to remove the principal objection to stem cell research.
“There is no rational reason left to oppose this research,” said Dr. Robert Lanza, vice president of Advanced Cell Technology and leader of a team that reported the new method in an article published online by the journal Nature.
But critics of human embryonic stem cell research raised other objections, citing the possible risk to the embryo from using the technique, and the fact that it depends on in-vitro fertilization, the generation of embryos outside the womb from a couple’s egg and sperm.
The new technique would be performed on an embryo when it is two days old, after the fertilized egg has divided into eight cells, known as blastomeres.
In fertility clinics, where the embryo is available outside the mother in the normal course of in-vitro fertilization, one of these blastomeres can be removed for diagnostic tests, such as for Down’s syndrome, and the embryo, now with seven cells, can be implanted in the mother if no defect is found.
Many such embryos have grown into apparently healthy babies over the ten years or so the diagnostic tests have been used.
Up to now, human embryonic stem cells have been derived at a later stage of development when the embryo consists of about 150 cells. Harvesting these cells destroys the embryo.
Last year, Dr. Lanza reported that embryonic stem cell cultures could be derived from the blastomeres of mice, a finding others have confirmed. He now says the same can be done with human blastomeres.
Although he used discarded human embryos in his experiments, he said that anyone who wished to derive human embryonic stem cells without destroying an embryo could use a blastomere removed for the test, called pre-implantation genetic diagnosis or P.G.D. “By growing the biopsied cell overnight, the resulting cells could be used for both P.G.D. and the generation of stem cells without affecting the subsequent chances of having a child,” he said.
Ronald M. Green, an ethicist at Dartmouth College and an adviser to Advanced Cell Technology, said he hoped the new method “provides a way of ending the impasse about federal funding for this research.”
He said he believed the method should be seen as compatible with the Dickey-Wicker amendment, the Congressional action that blocked the use of federal funds for research in which a human embryo is destroyed or exposed to undue risk.
Dr. James Battey, head of the stem cell task force at the National Institutes of Health, said it was not immediately clear if the new method would be compatible with the Congressional restriction, since removal of a blastomere subjects the embryo to some risk. But the embryos that are P.G.D.-tested seem to grow into babies as healthy as other babies born by in-vitro fertilization, Dr. Battey said.
President Bush allowed federal funding for research on human embryonic stem cells, provided they were established before August 9, 2001. Although that might seem to rule out any new cell lines derived from blastomeres, Dr. Battey said it was not clear if that would be the case, since the embryo is not destroyed, and that he would seek guidance on the point.
Critics, however, have a range of objections to the research. Catholic bishops, in particular, oppose both in-vitro fertilization and P.G.D. testing, and therefore still object to the research, even though the cells would be derived from an embryo that is brought to term.
Richard Doerflinger, deputy director for pro-life activities at the United States Conference of Catholic Bishops, said the church opposed in-vitro fertilization because of the high death rate of embryos in fertility clinics and because separating procreation from the act of love made the embryo seem “more a product of manufacture than a gift.”
Asked if he meant the parents of an in-vitro child would love it less, Mr. Doerflinger said he was referring to the clinic staff.
“The technician does not love this child, has no personal connection with the child, and with every I.V.F. procedure he or she may get more and more used to the idea of the child as manufacture,” he said.
Dr. Leon Kass, former chairman of the President’s Council on Bioethics, said, “I do not think that this is the sought-for, morally unproblematic and practically useful approach we need.” He said the long-term risk of P.G.D. testing is unknown, and that the present stem-cell technique is inefficient, requiring blastomeres from many embryos to generate each new cell line. It would be better to derive human stem cell lines from the body’s mature cells, he said, a method that researchers are still working on.
Scientists welcomed the new development, but also expressed concerns. Dr. Irving Weissman, a stem cell expert at Stanford University, said the new method, if confined to P.G.D.-derived blastomeres, would not provide a highly desired type of cell, those derived from patients with a specific disease.
NYT
Well if this story don't convince people that what we need is more research, and that we in fact don't know squat, not to mention the "moral objector" know even less than squat then nothing will.
“There is no rational reason left to oppose this research,” said Dr. Robert Lanza, vice president of Advanced Cell Technology and leader of a team that reported the new method in an article published online by the journal Nature.
But critics of human embryonic stem cell research raised other objections, citing the possible risk to the embryo from using the technique, and the fact that it depends on in-vitro fertilization, the generation of embryos outside the womb from a couple’s egg and sperm.
The new technique would be performed on an embryo when it is two days old, after the fertilized egg has divided into eight cells, known as blastomeres.
In fertility clinics, where the embryo is available outside the mother in the normal course of in-vitro fertilization, one of these blastomeres can be removed for diagnostic tests, such as for Down’s syndrome, and the embryo, now with seven cells, can be implanted in the mother if no defect is found.
Many such embryos have grown into apparently healthy babies over the ten years or so the diagnostic tests have been used.
Up to now, human embryonic stem cells have been derived at a later stage of development when the embryo consists of about 150 cells. Harvesting these cells destroys the embryo.
Last year, Dr. Lanza reported that embryonic stem cell cultures could be derived from the blastomeres of mice, a finding others have confirmed. He now says the same can be done with human blastomeres.
Although he used discarded human embryos in his experiments, he said that anyone who wished to derive human embryonic stem cells without destroying an embryo could use a blastomere removed for the test, called pre-implantation genetic diagnosis or P.G.D. “By growing the biopsied cell overnight, the resulting cells could be used for both P.G.D. and the generation of stem cells without affecting the subsequent chances of having a child,” he said.
Ronald M. Green, an ethicist at Dartmouth College and an adviser to Advanced Cell Technology, said he hoped the new method “provides a way of ending the impasse about federal funding for this research.”
He said he believed the method should be seen as compatible with the Dickey-Wicker amendment, the Congressional action that blocked the use of federal funds for research in which a human embryo is destroyed or exposed to undue risk.
Dr. James Battey, head of the stem cell task force at the National Institutes of Health, said it was not immediately clear if the new method would be compatible with the Congressional restriction, since removal of a blastomere subjects the embryo to some risk. But the embryos that are P.G.D.-tested seem to grow into babies as healthy as other babies born by in-vitro fertilization, Dr. Battey said.
President Bush allowed federal funding for research on human embryonic stem cells, provided they were established before August 9, 2001. Although that might seem to rule out any new cell lines derived from blastomeres, Dr. Battey said it was not clear if that would be the case, since the embryo is not destroyed, and that he would seek guidance on the point.
Critics, however, have a range of objections to the research. Catholic bishops, in particular, oppose both in-vitro fertilization and P.G.D. testing, and therefore still object to the research, even though the cells would be derived from an embryo that is brought to term.
Richard Doerflinger, deputy director for pro-life activities at the United States Conference of Catholic Bishops, said the church opposed in-vitro fertilization because of the high death rate of embryos in fertility clinics and because separating procreation from the act of love made the embryo seem “more a product of manufacture than a gift.”
Asked if he meant the parents of an in-vitro child would love it less, Mr. Doerflinger said he was referring to the clinic staff.
“The technician does not love this child, has no personal connection with the child, and with every I.V.F. procedure he or she may get more and more used to the idea of the child as manufacture,” he said.
Dr. Leon Kass, former chairman of the President’s Council on Bioethics, said, “I do not think that this is the sought-for, morally unproblematic and practically useful approach we need.” He said the long-term risk of P.G.D. testing is unknown, and that the present stem-cell technique is inefficient, requiring blastomeres from many embryos to generate each new cell line. It would be better to derive human stem cell lines from the body’s mature cells, he said, a method that researchers are still working on.
Scientists welcomed the new development, but also expressed concerns. Dr. Irving Weissman, a stem cell expert at Stanford University, said the new method, if confined to P.G.D.-derived blastomeres, would not provide a highly desired type of cell, those derived from patients with a specific disease.
NYT
Well if this story don't convince people that what we need is more research, and that we in fact don't know squat, not to mention the "moral objector" know even less than squat then nothing will.
posted by madtom at 10:44 PM
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