Friday, Oct. 12, 2012

NEW YORK — A team of researchers has transplanted artificial cardiac muscle cells developed from multipurpose stem cells into six patients in the United States in the world's first clinical application of iPS cells, one of the researchers said Wednesday.

Shinya Yamanaka, who won this year's Nobel Prize in medicine or physiology for his development of iPS cells, declined comment on the transplants, while other experts said details about the medical performance should be carefully evaluated.

The researchers developed the muscle cells from induced pluripotent stem cells produced from the patients' livers and transplanted them to the patients, said Hisashi Moriguchi, a visiting professor at Harvard University.

A 34-year-old American male patient who was the first to receive the transplant in February now has normal heart functions and has been discharged from the hospital, Moriguchi said.

The patient suffered from liver cancer and received a liver transplant in February 2009. He developed ischemic cardiomyopathy this February, prompting the researchers to conduct the heart surgery.

The researchers took cells from the patient's original liver, which was kept after removal for the 2009 transplant, and developed iPS cells by adding protein and other medical agents from which they produced cardiac muscle cells. The muscle cells were placed in 30 locations in the patient's heart.

No rejection or cancer development was found in the heart, and his heart function gradually recovered to normal levels 10 days after the surgery, they said.

"We need to improve the efficacy and safety of such medical treatment . . . and think of ways to reduce economic burden on patients," Moriguchi said.

The researchers used an improved technique to produce iPS cells developed by Yamanaka, the professor from Kyoto University who jointly won this year's Nobel with John Gurdon of Britain. Such cells have the potential to grow into any type of body tissue.

"I cannot comment on the matter as the details are not known," Yamanaka said. The clinical application was reported by the media before being published as a paper in a scientific journal.

Yoshiki Sawa, a cardiovascular surgery expert at Osaka University, was cautious about evaluating the operations.

"It is not yet known if the cells that were transplanted actually had the ability to grow variably like the iPS cells," Sawa said.

"It is questionable that the performances can be described as clinical applications of the iPS cells."

In Japan, preparations are under way for transplants of retinas derived from iPS cells to patients with eye diseases.

Assistant honored

WASHINGTON — The New York Stem Cell Foundation said Wednesday it will award the Robertson Prize to a Japanese scientist who has long helped Shinji Yamanaka, this year's Nobel laureate in physiology or medicine, for his extraordinary achievements in translational stem cell research.

Kazutoshi Takahashi, 34, a researcher at Kyoto University, contributed greatly to the research into induced pluripotent stem (iPS) cells that led to Yamanaka's Nobel Prize win, the foundation said.

The Robertson Prize is given to young researchers in the field of human stem cell research.

Takahashi, a lecturer at Kyoto University's Center for iPS Cell Research and Application, is known to have been successful in producing iPS cells from mice in 2006 and from human skin cells in 2007 under Yamanaka.

Takahashi made a "vital contribution to induced pluripotent stem cell derivation," the foundation said in a statement.

The year's award will be presented at a ceremony in New York by Susan Solomon, head of the foundation, and Peter Coffey, the inaugural recipient of the prize in 2011 and executive director of translation at Santa Barbara's Center for Stem Cell Biology and Engineering at the University of California.

"Dr. Takahashi's path-breaking work truly has opened up the entire field of stem cell research," Solomon said in the statement. "In addition to his derivation of induced pluripotent stem cells, he focuses on improving this technique and other critical translational studies."

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