Dynamic cell update example (eg, stock quotes)?

Does there exist an example that demonstrates updating specific cells dynamically, ideally with some effect as well? Specifically I'm looking for strategies on how to "select" the cell within database to update (when my javascript function is invoked due to a message from rabbitmq). Right now our data is starting from some html create by Rails. But that can be done anyway that is needed to get to dynamically updated cells.

thanks!
-barry