I teach serveral classes and I end up using a few concepts in all of these
classes.   So such concepts are included in a number of differenct slide
sets.  Occasionally, I update information about a concept and wish I could
have a way of getting the slide(s) about that concept updated in all my
presentations.  Is there a way to do this?  

I thought a solution could be to create only one place for the concept
(perhaps along the lines of a glossary slide set), then when I need to
assemble a presentation, I could link to the relevant slide.  Is there a way
of doing this in ppt. or other programs?

Any help is appreciated in advance.  AB