Friday, March 23, 2007

Stem Cells at BigU, part II

The local papers have picked up on the recent New Scientist article (see previous post).

The Pioneer Press reports:

U stem cell research raises new questions
Journal says one image apparently used in patent for three discoveries
Pioneer Press

The accuracy of pioneering adult stem cell research at the University of Minnesota is under scrutiny again, as a scientific journal is questioning whether U researchers used a single image of a protein to represent three different scientific discoveries.

The university is investigating, said Tim Mulcahy, the U's vice president for research.

The latest concerns focus on a 2001 article in the medical journal Blood and a patent application, approved in 2006, related to the stem cell discoveries. Images in both documents are offered as proof that U researchers used the stem cells, derived from adult bone marrow, to create different types of proteins. But close inspection suggests the images are all of the same protein, not different ones, according to an article New Scientist published Wednesday.

While the magazine seems to hint that someone deliberately misrepresented the data, there is no evidence to support that conclusion, Mulcahy said.

"The university is going to conduct an objective, comprehensive review but we have no evidence at this point of any wrongdoing. We have to let the process go forward and await a conclusion from the investigation."

The nature of the errors reported by the New Scientist in this second case seem a little more difficult to dismiss as an honest mistake as is clear from a recent post on the Chronicle of Higher Education website:

March 22, 2007
New Allegation of Misrepresented Results From U. of Minnesota Stem Cell Scientists

Fresh accusations have emerged that stem-cell researchers at the University of Minnesota-Twin Cities misrepresented their results in a published report and a patent application. In a paper published in Blood and in a patent based on findings reported elsewhere, the same image appears to have been used to represent the results of two or three separate experiments, New Scientist reported on Wednesday.

The work, led by Catherine Verfaillie, who has since moved to the University of Leuven, in Belgium, concerns adult stem cells. Dr. Verfaillie’s surprising results showed that some of the cells, found in bone marrow, could make a wide variety of tissues, like bone, blood, and cartilage. Previously they were thought able to make only a limited set of blood-cell types.

The questionable image, a photograph of a gel used to separate out proteins of different sizes, seems to appear twice in the paper. One image shows three blots of protein labeled ß-actin, a protein found in all of the cell types. An apparent mirror image of that gel is shown on the same page, but in the second instance, it is labeled collagen II, a protein found in cartilage. In the patent, the flipped image is said to represent a third protein, one specific to bone, New Scientist reported.

Dr. Verfaillie previously used a single image to represent two different experiments in a papers published in Nature and Experimental Hematology. An ethics review conducted by the University of Minnesota found that instance to be an unintentional mixup. Sanford Shattil, editor of Blood, told New Scientist that the journal would look into the new matter. —Susan Brown

The results of a second investigation at BigU should be interesting.



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