Health

Doctors generate spinal cells

With a genetic tweak, scientists have created an unlimited supply of a type of nerve cells found in the spinal cord, and have been able to use the cells to partially repair damaged spinal cords in lab animals.

While application of the discovery to humans is still years away, being able to generate such a limitless supply of the specialized nerve cells has long been a goal toward treating many neurological diseases.

"This work is the culmination of six years of work, and it will be many more years before an approach like this can be tried in human patients. But the promise is extraordinary," said Dr. Steven Goldman, a professor of neurology at the University of Rochester Medical Center in New York.

His team reports online today and in the March issue of Nature Biotechnology that it was able to create the unique cells by introducing a gene called telomerase, which allows stem cells to live indefinitely, into more specialized "progenitor" cells.

"The progenitor cells are immortalized at a stage when they only give rise to the type of neuron we want, thus becoming an ongoing source," said Goldman, whose work was supported by Project ALS and the Christopher Reeve Paralysis Foundation.

Goldman's team propagated the cells for more than two years, the longest anyone has ever maintained a line of progenitor cells.

Using some of those neurons, a group of Goldman's colleagues led by Dr. Maiken Nedergaard, a professor of neurosurgery, injected the cells into rats in which small sections of spinal cords had been damaged. The cells replaced the damaged part of the spinal cord with new nerve cells. But after about a month, the cells in the animals stopped proliferating, as neurons in the spinal cord normally do.

MILWAUKEE - Infants who have a certain gene and live with a dog have stronger immune systems than those who don't and are less likely to develop allergies or eczema, a study shows.

However, the authors warn that the results are still preliminary and say that parents shouldn't acquire pets just to try to prevent potential allergies.

"We plan to continue to follow these kids to see if this is a long-term effect," said James E. Gern, a pediatric allergist at the University of Wisconsin-Madison and author of the study.

The researchers followed 285 infants - each with at least one parent with allergies or asthma - from birth to age 1 and found eczema in 12 percent of the infants with dogs, compared with 43 percent of infants without the pet.

Gern said that it is likely the dirt that dogs bring into the house that triggers the response. The same results were not found with infants who lived with cats, although other studies have shown that having more than one cat is beneficial, he said.

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