An important post from the Scholarly Open Access blog by Jeffrey Beall, University of Colorado. Why you cannot trust many publications in PubMed searches these days, but how to confirm trusted journal list by limiting your searching to just Medline. Know the difference. Peer-reviewed science journals appearing in the Medline database are curated by the National Library of Medicine (NLM) at the NIH (National Institutes of Health).
There is very little requirement for a journal to get its content indexed in the PubMed database however, and there is no curation process by the NLM.