1. A method for searching a database of information, the database of information comprising information related to a plurality of content units, the information related to the plurality of content units comprising a plurality of stored annotations related to the plurality of content units, the plurality of stored annotations having been generated by processing the plurality of content units using a first clinical semantic interpretation engine, the first clinical semantic interpretation engine processing the plurality of content units according to at least one annotation model that defines at least one annotation type identifying information having a medical significance, each stored annotation of the plurality of stored annotations comprising a semantic label and content of the stored annotation, the method comprising: receiving a query; determining at least one query annotation relating to the query by processing the query using a second clinical semantic interpretation engine, the second clinical semantic interpretation engine processing the query according to the at least one annotation model, wherein the at least one query annotation comprises a first query annotation, wherein the first query annotation comprises a semantic label for the first query annotation and content of the first query annotation; and searching the database based at least in part on the first query annotation.