Human cells grow in mice

The so-called progenitor cells teamed up to form working blood vessels that connected to the circulatory systems of the mice, the team at Harvard Medical School and Children's Hospital Boston reported.

"What's really significant about our study is that we are using human cells that can be obtained from blood or bone marrow rather than removing and using fully developed blood vessels," said Harvard's Joyce Bischoff, who led the study.

Her team used immature cells, known as progenitor cells, grown under special lab conditions before being implanted into mice. Once implanted, the cell mixture grew and differentiated into a small ball of healthy blood vessels, they reported in the journal Circulation Research, published by the American Heart Association.

They used endothelial progenitor cells, which mature into cells that line the blood vessels, and mesenchymal progenitor cells, which differentiate into the cells that surround the lining and provide stability.

A mixture of cells from adult blood and bone or from umbilical cord blood worked the best, they said.

Possible cure for damaged blood vessels
They hope to find a way to help the body replace blocked or damaged blood vessels, such as arteries blocked in a heart attack or stroke.

"What we are most interested in right now is speeding up the vascularization," Bischoff said in a statement. "We see very good and extensive vasculature in seven days and we'd like to see that in 24 or 48 hours. If you have an ischaemic tissue, it's dying tissue, so the faster you can establish blood flow the better." - (Reuters Health)

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July 2008