I installed a new light fixture in our office. When I turned on the new fixture, it shorted. I removed the fixture and found bare wires touching where the insulation had been cut by the threaded rod.

All of the outlets and switches in that room are now dead. All other outlets/switches in the house seem to be working. I cannot find a "tripped" GFI. I am thinking of checking the circuit breakers in the service panel to see if one has failed. Is a failed circuit breaker liekly? Any other suggestions?

Are you using GFCI Breakers or GFCI receptacles?

What piece of threaded pipe are you speaking about. Can you append a picture of the installation site.

Have you inspected your main panel box for a tripped breaker?

With power off, I would look inside that 1 box, ALL connections.
Sometime a breaker will trip, but not throw, slight pressure towards off can reveal.