Support : Publications : Chronolog Archives : March/April 2004

MEDLINE^® Reload Completed on Dialog and Dialog DataStar

The reload of MEDLINE (Files 154,155/MEDL,MEZZ) on Dialog and Dialog DataStar was completed earlier this year. Every year MEDLINE is reloaded because the U.S. National Library of Medicine (NLM) re-indexes relevant documents from the whole database with changed medical terms and removes deleted terms. Our MEDLINE customers were informed of the changes to 2004 MEDLINE at the time of the reload. Changes are summarized in this article.

Changes in MEDLINE 2004

There are no changes to the actual record structure in MEDLINE for 2004. There are, however, a number of significant changes to the Medical Subject Headings (MeSH®). You should familiarize yourself with those changes as they will affect your search strategies. You may also need to adapt your Alerts to ensure that you receive the desired output. Generally, the NLM does not retrospectively index all MEDLINE citations with new MeSH Headings. Therefore, searching for a new MeSH term may effectively limit retrieval to citations indexed after the term was introduced. However, those terms that are changed or deleted are usually applied to the whole database during the NLM's end of year processing.

Over 6,500,000 records in the 2004 reload have been revised, primarily as a result of changes from 2003 to 2004 MeSH. You can review a summary of the major changes below. However, you are strongly advised to read the National Library of Medicine's comprehensive articles, "What's New for 2004 MeSH" and "MEDLINE Data Changes ­ 2004," both to be found at the NLM's Web site at www.nlm.nih.gov/pubs/techbull/current_issue.html.

Summary of MeSH Changes 2004

• 666 descriptors were added, representing topics with no directly corresponding descriptors in 2003 MeSH
• 109 descriptors were replaced with more up-to-date terminology
• 20 descriptors were deleted
• 484 “see references” (entry terms) were added

1. Case Reports — for 2004, this MeSH heading has been deleted as a descriptor and is replaced by a Publication Type.
   
   
2. Toxicity — this Subheading has been revised for 2004 to allow the use for both experimental and environmental exposure.
   
   
3. Expansion of Trees — the MeSH Trees were expanded from nine to eleven levels to allow a more accurate reflection of the hierarchy in elaborated and complex areas. There is one 11-level heading:
   Sex Chromatin: A11.284.430.106.279.345.190.160.180.383.800
   An example of a 10-level heading is:
   Trypanosoma lewisi: B01.500.841.750.443.950.450.868.887.410.
   
   
4. Animals — the old descriptor ANIMALS was changed to ANIMAL POPULATION GROUPS. It will retain all indented terms. The check tag ANIMAL has been changed to a new descriptor ANIMALS. It functions as both a descriptor and a check tag and is treed at B1.
   
   
5. Bacteria (B3) — this subcategory was expanded with 310 new descriptors.
   
   
6. Amino Acids, Peptides and Proteins (D12) — 246 new descriptors were added.
   
   
7. Complex Mixtures (D20) — this is a new subtree. It contains descriptors for heterogeneous materials such as Manure, Soil, and Venoms.
   
   
8. Chemical Actions and Uses (D27) — consists of the MeSH descriptors used for Pharmacological Activity (PA). It has been regrouped into Pharmacologic Actions (D27.505). In the D27 subtree, descriptors that included chemical structure in the name were removed. For example, Antibiotics, Aminoglycoside was deleted and those citations maintained to Anti-Bacterial Agents (formerly Antibiotics) and to Aminoglycosides. The duplicated tree of Anti-Infective Agents (formerly D20) has been deleted. The MeSH heading, Antibiotics, has a new preferred heading, Anti-Bacterial Agents.
   
   
9. Physiology (G) — Circulatory and Respiratory Physiology (G9) and Musculoskeletal Physiology (G11.427) were restructured into two new categories: physiological phenomena and physiological process.
   
   
10. Ethnic Groups and Geographic Origins (I & M) — The MeSH descriptor Racial Stocks and its four children (Australoid Race, Caucasoid Race, Mongoloid Race, and Negroid Race) have been deleted from MeSH in 2004 along with Blacks and Whites.
    
    

Other Changes to MEDLINE for 2004

1. Identification of Clinical Trials in MEDLINE – During 2003, "Randomized Controlled Trial" or "Controlled Clinical Trial" Publication Types, along with their parent Publication Type of Clinical Trial, were added to over 1,900 MEDLINE citations identified by the Cochrane Collaboration.
   
   
2. New Status Value: In Data Review – this is used for publisher-supplied citations after issue level bibliographic data verification only (not the NLM-created ones which have full quality control for all data elements before entering the database). These items are checked for correctness of journal, date of publication, volume and issue, and then enter the database with status “In Data Review.” Once the rest of the citation has been verified, the items are re-released carrying a status value of “In Process.”

Changes Made by Dialog and Dialog DataStar

Dialog

Beginning with the 2004 updates, the AN= record identifier will no longer be provided. Please use AA= instead. The Dialog Bluesheet has been updated with this change.

Dialog DataStar

• The Medical Vocabulary file MVOC now has an Accession Number (AN) paragraph with update date; the Annotation paragraph, formerly labeled AN, is now labeled AT.
  
  
• Please note that MVOC contains the 2004 version of MeSH. The 2003 version of MeSH continues to be available in MV03 should you need it for comparison purposes.
  
  
• Electronic publication dates (where applicable) are now noted in the source paragraph.
  
  
• Refer to Dialog DataStar's Database of Databases, BASE, for a complete user guide to MEDLINE. Search for BASE-MEDL.

Please do not hesitate to contact the Knowledge Center if you have any questions about the MEDLINE reload.

top