Chemicals and Drugs in PubMed: Online Search Clinic

Posted by Linda Milgrom on August 28th, 2007 Posted in: News From NNLM PNR, Training & Education

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NLM and the National Training Center and Clearinghouse recently conducted an hour-long clinic that covered how the MeSH vocabulary is used to describe substance concepts and how to search PubMed for relevant articles. The webcast of this August 23rd clinic was recorded and is available, along with a transcript and copies of the presenter’s slides, at http://www.nlm.nih.gov/bsd/disted/clinics/chem.html. Questions posted by participants and NLM’s responses will be added soon.

Important “take home” messages from the clinic:

1. In general, use unqualified substance names for the most comprehensive results. If you must qualify, use the [NM] search tag to find your substance as either a MeSH term or a supplementary concept or substance name.

2. Check MeSH for previous indexing to capture the literaturre indexed prior to when the specific substance term was added to MeSH.

3. Use pharmacological action terms for precision. To combine with a substance term, search the pharmacological action term as a MeSH heading [MH] so as not to explode and include all of the substances with that pharmacological action.

4. Ignore stereoisomerism (identified as the letters D, L, DL, R, or S, or the symbols plus or minus before a substance name) when identifying substance names.

5. If you can’t find a salt, try the general compound.

6. Search by CAS registry number [RN] only after checking MeSH, as recently added substances do not have an RN.

7. In chemical or molecular names, include all commas and hyphens, but delete parentheses or square brackets (which would be confused as nesting or qualifier symbols by PubMed).

8. If you cannot find the chemical in MeSH, try searching by fragments of the chemical name in the MeSH database.

9. Try the PubChem Substance database to find substances, especially if you have only the molecular name, structure, or weight.