Last Friday the National Institutes of Health announced that they were proposing a "technical change" in their Guidelines for destruction of human embryos, a.k.a. Guidelines for Human Embryonic Stem Cell Research.

The change would allow use of younger human embryos in experiments. As published today in the Federal Register, the change in definition for embryonic stem cells would be:

For the purpose of these Guidelines, "human embryonic stem cells (hESCs)" are cells that are derived from the inner cell mass of blastocyst stage human embryos pluripotent cells that are derived from early stage human embryos, up to and including the blastocyst stage, are capable of dividing without differentiating for a prolonged period in culture, and are known to develop into cells and tissues of the three primary germ layers.

You can submit comments on this proposed change. Note that the deadline for comments is 11:59pm EST on March 24, 2010 (a 30-day comment period.) Apparently NIH doesn't want to read a lot of critiques--comments are limited to 6,000 characters, including spaces. It remains to be seen whether NIH will ignore the majority of comments as it did for the initial guidelines.

This expands the unethical use of human embryos, and creates additional incentives to cannibalize more embryos. Stating that the guidelines are "ethical" simply puts a veneer on unethical practices; they are simply providing a recipe for human embryo destruction so that taxpayers funds can be used to reward the scientists.

The redefinition of "embryonic stem cells" is primarily for the benefit of the company Advanced Cell Technology (ACT), so that they can qualify for taxpayer funding. ACT had previously submitted seven hESC lines for approval (an eighth was added after the announcement Friday), and intends to submit at least one more hESC line. At least four of their lines were derived by removing a blastomere (one of the cells of an early embryo), supposedly leaving the remainder of the embryo intact. They term these lines NED ("no embryo destruction").

The designation is dubious. Robert Lanza of ACT first published their derivation of hESC lines from a single blastomere in 2006, and Lanza stated at that time "What we have done, for the first time, is to actually create human embryonic stem cells without destroying the embryo itself." But buried in the paper was the fact that all of the embryos used in the experiments had actually been destroyed. The misleading statements led to publication of a corrected paper and and addendum to "clarify" the data.

In a subsequent publication in 2008, Lanza said "If we base this on objective scientific criteria, there's no evidence that removing a single blastomere harms the embryo." But even in this paper, Lanza's own data show that not all embryos survived unharmed--the paper notes that only 80-85% of the embryos developed further to the blastocyst stage. Story Landis, head of the National Institutes of Health Stem Cell Task Force and director of the National Institute of Neurological Disorders, told the Hartford Courant, "There needs to be definitive scientific evidence that no harm was done to the embryo." Landis pointed out that women undergoing in-vitro fertilization who had cells extracted from an embryo for genetic testing had lower rates of pregnancy than women who were implanted with embryos that had not undergone the technique.

The whole question of PGD (preimplantation genetic diagnosis) on which Lanza bases his theory has been called into question in terms of possible embryo harm. A study in 2007 in the New England Journal of Medicine indicated that such a technique harms embryos, resulting in lower pregnancy rates. In 2007, the American Society for Reproductive Medicine recommended against PGD for any condition, based on the data that there was possible harm to embryos. Other papers in 2008 by a Belgian group and a Dutch group showed similar results, and a recent review makes the same point.

The question of not just destruction but possible harm to the embryo affects potential funding of the ACT technique. The Dickey-Wicker amendment prohibits federal funding of embryo experiments in which there is a "risk of injury or death" to the embryo.

Did ACT actually create new embryos for harvest and destruction, by removing one cell from the early embryo? The question is also important for possible taxpayer funding of experiments with the NED lines, because NIH's own guidelines state that

"Research using hESCs derived from other sources, including somatic cell nuclear transfer, parthenogenesis, and/or IVF embryos created for research purposes, is not eligible for NIH funding."

It's been shown that a four-cell human embryo can be disaggregated and each of the four cells can individually form a complete new embryo. The newly-created human embryos from this embryo-splitting technique have been used for derivation of embryonic stem cells. It's unclear whether the cells of an eight-cell human embryo also retain totipotency (the ability to form a complete new embryo), but experiments with mice suggest that at the 8-cell stage and even perhaps the 16-cell stage, the cells may retain that ability. If that were the case for human embryos, Lanza's technique may have first created a new embryo with his biopsy method, then destroyed it in the process of forcing it to become a new hESC line. This would contravene the NIH guidelines.

The redefinition is also a move by NIH to cover their nether parts, as they had previously approved three hESC lines from George Daley of Harvard that were actually created from human embryos that had not yet reached the blastocyst stage. NIH has put those lines on Hold for now, until they can rush through the redefinition. But the proposed new language would again expose more human embryos to risk of destruction. Some could even be defined as "abnormal" or "unable to develop", making them targets for destruction. Note such definitions are usually based on eyeball assessments that have previously been shown as flawed.

But perhaps more than anything, this redefinition illustrates the willingness of NIH to change the rules to fit their desires for more embryos. Expect more abuses in the future.