Discussing Scott discussing ACT's stem cell work
Californiastemcellreport.blogspot quotes Christopher Thomas Scott:
Advanced Cell Technology's announcement in Nature last week wound up the rhetoric—yet again—surrounding embryonic stem cell research. The Alameda, California, company claims an embryonic stem cell line can be made without harming a human embryo. The ACT technique is modeled after an in vitro fertilization (IVF) diagnostic test called PGD. The test plucks one cell out of a two day-old embryo containing eight cells or so. The cell’s DNA is screened for dozens of deadly diseases. If the test is positive, the embryo is discarded. If no disease genes are detected, the embryo—which quickly makes a new cell to replace the missing one—is implanted. The procedure seems safe: more than a thousand children have been born since the test was unveiled in the early 1990’s.
From a scientific perspective, the ACT paper is interesting, but not groundbreaking. The researchers repeated a method they perfected earlier in mice using human cells; that’s no mean feat. They claim the type of cell they used—called a blastomere—produced an embryonic stem cell line. If other labs can repeat the result and if the lines can make different, functional cell types, that's pretty cool.
As is evident now, "what ACT did" was NOT modelled after the IVF technique of PGD. ACT did not remove one blastomere from a blastocyst and allow the remaining cells to survive. ACT did argue that the IVF technique of PGD illustrated that SOMEONE could remove one cell from an 8-16 cell blastocyst and, based on past results, have a reasonable expectation that the remaining cells would remain viable (to produce a baby in the IVF technique).
"What ACT did" was to create a human stem cell line from a single cell taken from an 8-16 cell blastocyst. Scott said of this: "The researchers repeated a method they perfected earlier in mice using human cells; that’s no mean feat." Not much discussed is the reality that the single cell was in the presence of other human cells AND in the presence of mouse feeder cells. The important details of the ACT experiment are in figuring out why ACT had a low success rate, whether the presence of other human cells was necessary, and whether the use of mouse feeder cells can be avoided.
Although Scott said "The Alameda, California, company claims an embryonic stem cell line can be made without harming a human embryo," the ACT work reported in Nature was conducted in Worcester, Massachusetts.
Although Scott said "The procedure seems safe: more than a thousand children have been born since the test was unveiled in the early 1990’s," Scott did not mention that IVF physicians warn patients about risks associated with PGD. Not every IVF couple who might benefit from PGD does do PGD. There were about 30 children born through an IVF process known as cytoplasmic transfer. Although they are all alive, no one in the U.S. is doing cytoplasmic transfer anymore.
Curiously, Scott concluded that is episode illustrates why the California Institute of Regenerative Medicine mustn’t lose focus on proven methods used to derive embryonic cell lines. "Proven" methods implicate the Thomson / WARF patents.
Advanced Cell Technology's announcement in Nature last week wound up the rhetoric—yet again—surrounding embryonic stem cell research. The Alameda, California, company claims an embryonic stem cell line can be made without harming a human embryo. The ACT technique is modeled after an in vitro fertilization (IVF) diagnostic test called PGD. The test plucks one cell out of a two day-old embryo containing eight cells or so. The cell’s DNA is screened for dozens of deadly diseases. If the test is positive, the embryo is discarded. If no disease genes are detected, the embryo—which quickly makes a new cell to replace the missing one—is implanted. The procedure seems safe: more than a thousand children have been born since the test was unveiled in the early 1990’s.
From a scientific perspective, the ACT paper is interesting, but not groundbreaking. The researchers repeated a method they perfected earlier in mice using human cells; that’s no mean feat. They claim the type of cell they used—called a blastomere—produced an embryonic stem cell line. If other labs can repeat the result and if the lines can make different, functional cell types, that's pretty cool.
As is evident now, "what ACT did" was NOT modelled after the IVF technique of PGD. ACT did not remove one blastomere from a blastocyst and allow the remaining cells to survive. ACT did argue that the IVF technique of PGD illustrated that SOMEONE could remove one cell from an 8-16 cell blastocyst and, based on past results, have a reasonable expectation that the remaining cells would remain viable (to produce a baby in the IVF technique).
"What ACT did" was to create a human stem cell line from a single cell taken from an 8-16 cell blastocyst. Scott said of this: "The researchers repeated a method they perfected earlier in mice using human cells; that’s no mean feat." Not much discussed is the reality that the single cell was in the presence of other human cells AND in the presence of mouse feeder cells. The important details of the ACT experiment are in figuring out why ACT had a low success rate, whether the presence of other human cells was necessary, and whether the use of mouse feeder cells can be avoided.
Although Scott said "The Alameda, California, company claims an embryonic stem cell line can be made without harming a human embryo," the ACT work reported in Nature was conducted in Worcester, Massachusetts.
Although Scott said "The procedure seems safe: more than a thousand children have been born since the test was unveiled in the early 1990’s," Scott did not mention that IVF physicians warn patients about risks associated with PGD. Not every IVF couple who might benefit from PGD does do PGD. There were about 30 children born through an IVF process known as cytoplasmic transfer. Although they are all alive, no one in the U.S. is doing cytoplasmic transfer anymore.
Curiously, Scott concluded that is episode illustrates why the California Institute of Regenerative Medicine mustn’t lose focus on proven methods used to derive embryonic cell lines. "Proven" methods implicate the Thomson / WARF patents.
posted by Lawrence B. Ebert at 2:43 PM
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