To fix the problem, highlight the part of the search that you want to conduct and paste it into the query box, then re-run it.
PubMed broke apart the terms. To fix the problem, put the search terms in quotations. This will search for the terms together, but will also turn off PubMed's ability to do automatic term mapping.
For even better results, add alternative terms and re-run the search.
Add / Reorder