WASHINGTON (AP) - The Obama administration's expansion of stem cell research suffered a significant setback with a judge's ruling that blocks important work on treating life-threatening conditions, say private groups pushing for scientific breakthroughs in medicine.

Monday's decision by U.S. District Judge Royce Lamberth will "drive the best scientific minds into work less likely to yield treatments," says Sean Tipton of the American Society for Reproductive Medicine.

"It will be incredibly disruptive," he added.

Stem cell research holds the potential to address some of the most difficult areas in the medical field - from spinal cord injury to diabetes to Parkinson's, which all have resisted traditional treatment.

Two doctors who do research with adult stem cells are James Sherley of the Boston Biomedical Research Institute and Theresa Deisher of AVM Biotechnology. They argue that the guidelines will result in increased competition for limited federal funding and will injure their ability to compete successfully for National Institutes of Health stem cell research money.

Scientists say they need to do research with embryonic stem cells, as well as so-called adult ones, because the former are more flexible, and the National Institutes of Health is funding both types.

In his decision, Lamberth concluded that the two researchers have demonstrated a strong likelihood of success in their argument that the Obama administration's government guidelines violate the intent of the law about federal funding of embryo destruction.

"As demonstrated by the plain language of the statute, the unambiguous intent of Congress is to prohibit the expenditure of federal funds on ‘research in which a human embryo or embryos are destroyed,' " the judge wrote.

Having concluded that the law is unambiguous, "the question before the court is whether ESC research is research in which a human embryo is destroyed. The court concludes that it is," Lamberth added