Apt-get downloading packages

[jim tate <mickeyboa comcast net>]

Fedora core Test1.
Apt-get upgrade , downdloaded a number of RPM packages from 
freshrpms.us.net/development
and put them in the /var/cache/apt/archive and they are  later versions 
than installed .
Why can't I rpm -Uvh *.rpm those packages?  Apt-get comes back with 
something about
"Unsigned /var/cache/apt/archive (for all the packages) what gives, Am I 
of the understanding
that you just can't upgrade Fedora Test1 core?

Thanks
Jim Tate