Nature to change study reporting method of creating stem cells without destroying embryos

Officials from the journal Nature have said they plan to change a paper published in the journal's Aug. 24 edition describing a technique that could derive human embryonic stem cells without destroying the embryo to further clarify that none of the embryos used in this particular study survived the experiment, the Chicago Tribune reports (Manier, Chicago Tribune, 9/1).

Robert Lanza, medical director of Worcester, Mass.-based Advanced Cell Technology, and colleagues described the technique as removing a single cell - known as a blastomere - from a three-day-old embryo with eight to 10 cells and using a biochemical process to create embryonic stem cells from the blastomere.

Researchers removed 91 blastomeres from 16 thawed embryos donated by fertility clinic patients and found that more than half of the blastomeres began to multiply and that in two cases the blastomeres became embryonic stem cells.

The method of removing a cell from the embryo is based on preimplantation genetic diagnosis, or PGD, which usually is used to test the cell for genetic deficiencies.

At the time the Nature article was published, Lanza said the research destroyed some of the embryos used but single-cell extractions that leave the embryo unharmed should be feasible in the future.

In addition, the researchers wrote that single cells taken from three-day-old embryos "have never been shown to have the intrinsic capacity to generate a complete organism in any mammalian species."

Nature last week corrected wording in a news release it had distributed in advance of the study's release after Richard Doerflinger of the United States Conference of Catholic Bishops in an e-mail wrote that the results presented in the release were misleading.

According to Doerflinger, the release did not make it clear that the embryos used in the research did not survive in the experiments (Kaiser Daily Women's Health Policy Report, 8/24).

"We feel it necessary to explain that ... the embryos that were used for these experiments did not remain intact," Ruth Francis, Nature senior press officer, said in an e-mail (McCullough, Philadelphia Inquirer, 8/311).

A Nature spokesperson on Thursday said that the "fate of the embryos isn't obvious" in the study and that the journal might change part of the study's abstract and a diagram that accompanied the study.

She added the study's findings remain uncontested. Lanza said the clarification "doesn't change the scientific point of the paper" (Chicago Tribune, 9/1).