Perhaps you should try some spelling variations:
"mediated diseases" » "related diseases", "related disease"
"complicated case" » "complicated acute", "complicated chapter", "complicated grief"
"complicated cases" » "complicated acutes", "complicated chapters", "complicated griefs"
"medical diseases" » "tropical diseases"

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (((("complicated case") OR ("complicated cases"))) OR ((("mediated diseases") OR ("medical diseases")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"complicated case\") or (\"complicated cases\"))) or (((\"mediated diseases\") OR (\"medical diseases\"))))".
• Removing quotes may allow a broader search: (((( complicated case ) or ( complicated cases ))) or ((( mediated diseases ) OR ( medical diseases )))).
• Adding a wildcard symbol may retrieve word variants: (((("complicated case") or ("complicated cases"))) or ((("mediated diseases") OR ("medical diseases"))))*.