Stem Cells

The U.S. Patent and Trademark Office has invalidated three broad patents for human embryonic stem cells that have been blamed for slowing research in the highly visible field of regenerative medicine.

In 2003, federal officials inspected California-based Advanced Cell Technology. They rummaged through refrigerators, scrutinized labs and checked microscopes to make sure the firm wasn't using federally funded equipment to work on embryonic stem cells. Similar scenes have played out across the U.S. since President Bush issued an executive order banning federally funded research on embryonic stem cells created after 2001.

Researchers have demonstrated for the first time that the progression of Type 1 diabetes can be halted -- and possibly reversed -- by a stem-cell transplant that preserves the body's diminishing ability to make insulin, according to a study published today. The experimental therapy eliminated the need for insulin injections for months or even years in 14 of 15 patients recently diagnosed with the disease.

The Senate voted overwhelmingly Wednesday to reject restrictions President Bush has placed on embryonic stem-cell research. Bush plans to veto the bill, but his restrictions are unlikely to last for long after his presidency. The candidates running to succeed Bush in 19 months largely endorse federally supported stem-cell research. That support, coupled with the backing of a majority of Americans, means change is almost certain.

Stem cells derived from female mouse muscle regenerate muscle better than stem cells derived from male mice, researchers reported this week in the Journal of Cell Biology. Scientists made the discovery while researching muscular dystrophy, Johnny Huard of the Children's Hospital of Pittsburgh said. When researchers injected muscle-derived stem cells into male mice with dystrophy, 60% of the female stem cells did better than the average of the male cells.

Stem cells made from human embryos can home in on damaged eyes, hearts and arteries of mice and rats, and appear to start repairs, researchers report. Writing in the journal Nature Methods on Monday, a group led by researchers from biotech company Advanced Cell Technology said they had devised a straightforward way to make blood vessel precursor cells out of the stem cells.

Scientists have succeeded in reprogramming ordinary cells from the tips of mouse tails and rewinding their developmental clocks so they are virtually indistinguishable from embryonic stem cells, according to studies published today. If the discovery applies to human cells -- and researchers are optimistic that it will -- it would offer a straightforward method for creating a limitless supply of cell lines tailor-made for patients without ethical strings attached.

The House voted Thursday to send legislation removing limits on embryonic stem cell research to the White House, where it faces a certain veto by President Bush. The vote in the House was 247 to 176, or 35 votes short of the two-thirds majority the bill would need if Congress were to make it law over the president's objections. The Senate passed the stem cell bill in April by a tally of 63 to 34, with three senators absent.

President Bush on Wednesday vetoed legislation that would have allowed the use of federal funds to support embryonic stem cell research, the second consecutive year he has blocked such a bill. Proponents say embryonic stem cells -- which can turn into cells for many different kinds of human tissue -- offer the best chance of treating or curing many debilitating or fatal diseases.

A U.S. scientist said Tuesday that he had derived stem cells from cloned monkey embryos, a first that may help researchers develop new medical treatments for humans. Shoukhrat Mitalipov of the Oregon National Primate Research Center told scientists at a conference in Australia that he used somatic cell nuclear transfer, also known as therapeutic cloning, to produce embryos that were genetically identical to a 10-year-old rhesus macaque monkey.