"A year after Harvard University scientists began trying to create cloned human embryonic stem cells, they have been stymied by their failure to persuade a single woman to donate her eggs for the groundbreaking but controversial research.
The goal of the work is to create embryonic stem cells -- all-purpose formative cells that can develop into virtually any cell in the body -- that are genetically matched to a patient with a particular disease, such as diabetes. Studying such cells could give scientists new insights into the diseases and possibly lead to treatments.
"It's an important experiment and we can't do it," Kevin Eggan, an assistant professor of molecular and cellular biology at Harvard.
Without unfertilized eggs, scientists cannot create cloned embryonic stem cells through the conventional method. Called somatic-cell nuclear transfer, the procedure involves replacing the DNA in a donated egg with DNA extracted from a patient's cells. Scientists coax this new egg to grow for several days in a laboratory dish until it is an early embryo and stem cells can be obtained.
Over the last year, Harvard has spent tens of thousands of dollars on local newspaper ads in an attempt to recruit egg donors. Hundreds of women have responded to the ads, but none has followed through with donations, for a variety of reasons, Eggan said in an interview.
For one thing, egg donation requires repeated clinic visits and minor surgery under general anesthesia to remove the eggs from the ovaries. Women also face a small risk of ovarian hyperstimulation syndrome, an excessive absorption of fluids."For access to the full article, click here.