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Science Friday > Archives > 1999 > January > January 29, 1999:

Hour One: Stem Cell Research

Late last week, the U.S. Department of Health and Human Services announced that government funds could be spent on research involving human embryonic stem cells, despite legislation prohibiting federal spending on human fetal tissue research. The decision will allow the National Institutes of Health to continue funding research into human embryonic stem cells, which have the capability to develop into most types of cell in the body. One possible use of these cells, generating transplantable cells and tissues, could help treat many medical conditions. Figuring out how these cells grow, divide, and differentiate could also help researchers understand how humans develop. A continuous supply of human embryonic stem cells, which have a constant ability to divide, could even provide a useful source of material upon which to test possible new drugs.

Human embryonic stem cells can differentiate into many different cell types, including (a) gut cells, (b) neural cells, (c) bone marrow, (d) cartilage, (e) muscle, and (f) kidney. Image © Science , courtesy Univ. of Wisconsin.

The DHHS decided that because scientists have developed ways to artificially culture stem cells in vitro, these types of research would not violate laws forbidding spending on research involving fetal tissue (though the ancestors of the cultured cells originally came from fetal tissue.)

Also last week, scientists announced that adult stem cells taken from mouse brains could - when injected into the depleted bone marrow of other mice - change their nature and begin to generate blood cells. Adult stem cells normally replenish the supply of cells in parts of the body with rapid turnover, including the skin, intestines, and blood manufacturing system. However, before last week's announcement, it was assumed that adult neural stem cells made only replacement brain cells, while blood producing stem cells (hematopoeitic) cells made only replacement blood cells. The researchers' finding that adult stem cells are more versatile than previously thought could help sidestep some of the ethical issues associated with embryonic stem cell research.

On this hour of Science Friday, we'll talk about some of the scientific and ethical issues involved in stem cell research - as well as an intriguing way to repair damaged blood-producing stem cells using gene therapy and a modified form of the HIV virus. When properly modified, the virus can be used to inject healthy genetic material into damaged cells, instead of the disease-causing genetic material the virus usually carries. The experiment, when tried in mice, appeared to make the mice produce human hematopoeitic cells - and that has some people thinking about the possibilities. But is using a virus as virulent as HIV a good idea? We'll find out more.

Listen to this program in RealAudio!

Guests:

John Gearhart
Professor of Gynecology and Obstetrics
Johns Hopkins University School of Medicine
Baltimore, MD

Eric Meslin
Executive Director
National Bioethics Advisory Commission
Rockville, MD

Bruce Torbett
Scripps Research Institute
LaJolla, CA

Kent Smith
Research Associate
Scripps Research Institute
LaJolla, CA

Books/Articles Discussed:

Related Links:

Whyfiles: The Most Powerful Cell
National Bioethics Advisory Commission
The Scientist: Stem Cell Scientists Caution: Clinical Applications Remain Years Away

This segment produced by:
Annette Heist
Web producer:
Charles Bergquist