Index diseases using ontologies

We need to use ontology classes from disease ontology(ies) to attach to records in the NIF index. E.g. parkinson's or leukemia in clinicialtrials.gov. Currently NIF_Dysfunction is used, which has the former but not the latter.

Possible sub-tasks

• evaluate existing vocabularies/indexes w.r.t use cases (DO, MESH, OMIM, Orphanet, SNOMED, NCIt, NIF_Dysfunction)
• create recommendation; may be one of
• single existing resource
• multiple existing resources joined by owl equivalence and subclass axioms
• it's all hopeless; use free text
• ...
• create and maintain necessary ontology infrastructure