Research at Children's Hospital has found a molecular switch that sets off a response that can lead to necrotizing enterocolitis, a leading cause of death in premature babies.

Principal investigator Dr. David J. Hackam, pediatric surgeon and scientist at Children's, said Tuesday that further research will study how to reverse this switch and stop the intestine's immune response that often leads to NEC, a severe inflammatory disease that can require emergency surgery.

Dr. Hackam presented the research results over the weekend at a meeting of the American Society for Cell Biology.

He said the rising number of surviving premature babies has led to a rise in frequency of NEC. About 5 percent of premature births result in NEC, and it can be fatal in about half of those cases. After surgery removing the dead intestinal tissue, babies can suffer nutrition problems and other effects of short bowel syndrome.

???It???s one of the causes of short bowel syndrome,??? Dr. Hackam said, ???The intestine dies suddenly, for reasons not easily understood.???

Using baby mice in the lab, Dr. Hackam said the researchers gave the mice the exact disease the babies get.

They found when a molecular receptor known as Toll-like receptor-4 was blocked, the body was able to repair damaged intestinal tissue.

???We knew that the molecule that turns on the TLR4 switch plays a role in NEC,??? Dr. Hackam said. Both that molecule, an endotoxin, and the TLR4 switch are found in the intestine, so it was logical to see if there was a link, Dr. Hackam said.

Now, he said, ???We???re looking for ways to turn the switch off. Mice that can???t turn on the switch don???t get NEC.???