"Virgin" birth stem cells may offer tissue bank

Human egg cells can be tweaked to give rise to valued stem cells that match the tissue types of many different groups of people, U.S. and Russian researchers reported on Wednesday.

They said the stem cells they have created from unfertilized human eggs look and act like embryonic stem cells.

And they have been carefully tissue-matched in the same way as bone marrow donations to prevent the risk of rejection if they are transplanted into people.

The team at California-based International Stem Cell Corp. hopes to create a bank of tissue-matched stem cells that could be used as transplants that a patient's immune system would accept.

"The process is efficient, it is relatively safe and it is ethically sound," Jeffrey Janus, president and director of research at the company, said in a telephone interview.

The cells are created by a process known as parthenogenesis, a word that comes from Latin and Greek roots meaning virgin beginning.

It involves chemically tricking an egg into developing without being fertilized by sperm.

Several teams have now created parthenogenetic human stem cells from eggs...