HEALTHBEAT: New push to spur drugs for rare diseases, even as moms toil to fill that void

WASHINGTON (AP) -- Every other week, 7-year-old twins Addison and Cassidy Hempel have an experimental medicine injected into their spines in hopes of battling a rare, fatal disease.

And it's their mom who made that possible.

From her home in Reno, Nev., Chris Hempel persuaded scientists to share their research and managed to get the government to sign off on her daughters' unusual experiment. Hempel says getting help to fight a rare disease shouldn't be so hard.

But it's a huge challenge to generate drug company interest in the expensive testing of medicines for diseases so rare - like her girls' Niemann-Pick Type C - that the market is only a few hundred or few thousand people a year.

Michelle Obama's plane flew closer to big jet

WASHINGTON (AP) -- A plane carrying first lady Michelle Obama this week came even closer to a big military cargo jet than previously reported, the National Transportation Safety Board said Friday.

The distance between the two planes closed to 2.94 miles before air traffic controllers at Andrews Air Force Base outside Washington directed the first lady's plane to abort a landing, the board said in a statement. The Federal Aviation Administration had previously said there was more than three miles between the planes, and had ordered controllers' supervisors to oversee flights carrying the first lady and the vice president. A supervisor was already required to monitors flights with President Barack Obama on board.