More MS news articles for April 2001

As the Stem Cell Turns

http://www.wired.com/news/technology/0,1282,43340,00.html

2:00 a.m. April 26, 2001 PDT
By Kristen Philipkoski

The National Institutes of Health cancelled the first meeting of a panel that was supposed to review grant applications for human embryonic stem cell research.

One member of the review panel, speaking on condition of anonymity, told the Washington Post that the NIH offered no explanation for the cancellation.

The panel was to meet Wednesday, and no reschedule date has been announced.

President Bush had promised to re-examine a policy change announced by the Clinton administration in 2000. President Clinton circumvented a law against federally funded embryonic or fetal stem cell research by saying it was OK as long as the cells were obtained from a nongovernment source.

Applications for grants were due to the NIH by March 15, but Bush said he wasn't sure any grants would be given.

In the end, the call falls on the shoulders of Health and Human Services Secretary Tommy Thompson, who in the past has celebrated the potentials of embryonic and fetal stem cell research. But since becoming part of the Bush administration, his enthusiasm has cooled considerably.

Embryonic and fetal stem cells are like a clean slate. They have the ability to grow into any type of cell in the human body, a process called differentiation. Many stem cell researchers have believed that embryonic and fetal stem cells have a superior ability to regenerate and differentiate compared with other types of stem cells.

Researchers take adult stem cells from a growing list of organs including bone marrow, brain tissue and nasal cells (see below) and then have to "de-differentiate" the cells to get a clean slate.

The treatment has implications for any disease or injury that results in damaged organs, including Parkinson's, Alzheimer's and spinal cord injuries, just to name a few.

The Bush administration has not yet moved to change the guidelines, but Thompson has indicated the policy is under review. In the past Bush has said he opposes federally funded research for human stem cells from aborted fetuses.

The nose grows stem cells: Meanwhile, researchers continue to make progress with adult stem cells, which fall outside the controversy because they come from either cadavers or consenting adults.

Researchers at the University of Louisville Health Science Center in Kentucky harvested stem cells from the olfactory neuroepithelium -- a sensor in the nose -- of human cadavers.

The investigators reproduced the cells more than 100 times. The cells stayed alive for up to 16 months. Olfactory neuroepithelium stem cells differentiate into either neurons or myelin (a material that forms a sheath around nerve fiber). This makes them candidates for Alzheimer's, Parkinson's, multiple sclerosis and spinal cord injury treatment.

Unfortunately, the researchers predict that clinical trials in humans are at least five years away.

Stem cells in mice could help deaf: In the United Kingdom, researchers turned stem cells from mice into ear cells.

Researchers from the University of Bristol, hope their study could lead to an application for reversing deafness in humans. Some day deaf patients could receive cochlear implants along with stem cell injections. They hope the stem cells would encourage nerve growth leading to the implant.

And in the porcine stem cell department: Researchers injected cells from a pig fetus into a quadriplegic man in an attempt to help him walk again.

The procedure, which was done in Albany, New York, is the first of its kind.

Charles Dederick injured his spine in a 1997 motorcycle accident, leaving no feeling in his arms and legs. The researchers hope the injected pig cells will grow like they would in a developing pig, and create a new connection in his spine.

The scientists said the experiment is intended mainly to determine potential side effects. But if his brain can once again emit electric impulses, the impulses could signal his muscles to walk again.

Dederick said he still felt nothing in his arms and legs 11 days after the procedure.

Neurosurgeon Dr. Darryl DiRisio and orthopedic surgeon Dr. Allen Carl used a fine needle syringe to implant 14 million cells into Dederick's spinal cord over a period of 3-1/2 hours.

The surgeons said they used pig cells because they were more readily available, and to avoid the controversy surrounding the use of human fetal stem cells.

The research was funded by Diacrin (DCRN), a pharmaceutical company in Massachusetts.

In 2000, Yale University scientists were encouraged to try the procedure on humans when they restored nerve impulses in mice after splicing pig stem cells into their spines.

More stem cells, more mice: Researchers used stem cells from mouse embryos to create healthy pancreatic cells in diabetic mice.

Researchers at the National Institutes of Health generated the cells, which produced insulin when glucose was present in the blood of the mice.

The paper says the stem cells acted just like normal pancreatic islet cells -- the cells that produce insulin -- when injected into the mouse pancreas. And in addition to islet cells, the stem cells also grew into other important pancreatic hormones. The study is published in the April 26 issue of Sciencexpress. The research could lead to similar treatments in humans.

Another group of researchers created stem cells in mice using a cloning technique.

Like any transplantation procedure, stem cell techniques present the possibility of rejection by the patient's immune system. But if the stem cells were cloned from the patient's own cells, rejection wouldn’t be an issue.

Researchers at Rockefeller University, Sloan Kettering, and Advanced Cell Technology, proved the technique works, at least in mice. They used a technique called nuclear transfer to take the nuclei of mouse tail cells and transfer them into embryonic cells of mice.

The study is published in the April 27 issue of Science.

Are we smarter than chimps? Researchers in Germany compared the human genome to that of the chimpanzee, finding very little difference between the two.

In fact, only 1.3 percent difference exists between the genetic sequences of the two, according to Svante Pääbo of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

But Pääbo suggested last week, at the Human Genome Meeting in Edinburgh, Scotland, that it's not our gene sequence but the activity of genes that defines us as a complicated organism.

Gene activity is also called transcription. Pääbo and his group studied transcription in the brain, liver and blood of humans, chimps and rhesus macaque monkeys.

Gene activity looked similar in humans and chimps, but different from the macaque, which is more distant evolutionarily from humans. But gene transcription in the brain showed clear differences between humans and chimps.

"The (human) brain has accelerated usage of genes," Pääbo said, according to Nature News Service.

The Associated Press contributed to this report.