How can I protect my retired-disabled single brother's assets from nursing care costs?

If you are thinking of a Medicaid facility, then there is currently a 5 year "look back" period where they review all his assets to see if he qualifies. He will also be asked to turn over many of them to help defer the cost of care.
Your best bet is to sit down with an elder attorney or someone who specializes in medicare/medicaid law. It gets a little tricky.
Also, ask about living trusts.
good luck
Lilli