Quote Originally Posted by shadow1
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Are you are saying "course" means "a specific, discrete cycle"?
I could not find such a definition for "course".

http://www.google.com/search?hl=en&lr=& ... ine:course
Here's one of the definitions of the word course found in two different dictionaries.
medical treatment - especially British English - an amount of medicine or medical treatment that you have regularly for a specific period of time - course of injections/drugs/treatment etc
course (MEDICAL TREATMENT)
a fixed number of regular medical treatments: