his article highlights the additions and changes in 2005 Medical Subject Headings (MeSH).

Overview of Vocabulary Development and Changes for 2005 MeSH

• 487 Descriptors added with no directly corresponding descriptors in 2004 MeSH
• 129 Descriptors replaced with more up-to-date terminology
• 60 Descriptors deleted
• 340 see reference (entry terms) added

Totals by type of terminology

• 22,995 Descriptors
• 129 Publication Types
• 83 Subheadings/Qualifiers
• 146,248 Supplementary Concept Records (SCRs)

Publication Types
Review Literature [Publication Type] and Review, Academic [Publication Type] have been deleted as Publication Types. These concepts are now see Review [Publication Type].

Organisms - Category B
The taxonomy of Hominidae, the family comprising bipedal primate mammals, which includes humans, has been updated for 2005. Also, the check tag Human will be changed to a new descriptor Humans. For further information see the article 2005 MeSH Changes to Hominidae and the Check Tag Human; Resulting PubMed and NLM Catalog Change to Search for Animals. NLM Tech Bull. 2004 Nov-Dec;(341):e6.

The trees of the following organisms were revised and greatly expanded: Carnivora, Birds, Cyanobacteria, Clostridium, and Porifera. In the cases of Carnivora and Birds, there are now specific headings for many of the genera and species, with their scientific names. There are now headings for 20 species of Clostridium (previously 4) and for 7 specific subtypes of Clostridium botulinum. The sponges (Porifera) now have headings for several of the genera.

Within the Carnivora, new descriptors include:

New descriptors for birds include:

Kinases - Category D8
Mitogen-Activated Protein Kinases: A large number of distinct Mitogen-activated protein kinase isoenzymes are currently being discussed in the literature. Therefore, we have created descriptors for the three major subclasses: Extracellular Signal-Regulated MAP Kinases, JNK Mitogen-Activated Protein Kinases, and p38 Mitogen-Activated Protein Kinases. Specific mitogen-activated protein kinase isoenzymes with numbers ranging from 1 to 14 are listed under each of the three categories that they belong to. Many model organism-specific protein SCRs in this category and other protein classes have been created for 2005. Each of the SCRs is heading mapped to a specific isoenzyme descriptor class.

Mitogen-Activated Protein Kinase Kinases: Specific isoenzymes are now listed as descriptors under this heading. Many of the word patterns used to describe mitogen-activated protein kinase kinases are highly similar to those used to describe mitogen-activated protein kinases and MAP Kinase Kinase Kinases. Therefore each descriptor heading includes a variety of specific entry terms that correctly match terms in the literature.

MAP Kinase Kinase Kinases: This third category of signaling kinases acts on Mitogen-Activated Protein Kinase Kinases. The full name for this class "Mitogen-Activated Protein Kinase Kinase Kinases" is only an entry term in MeSH because of its length. Specific isoenzymes are now listed as descriptors under this heading. These descriptors also include a variety of specific entry terms that correctly match terms in the literature.

Category D5
The D5 tree now contains descriptors for chemicals categorized as Macromolecular Substances. The tree includes the major subcategory Polymers, which was formerly listed only under Biomedical and Dental Materials, and the new heading Multiprotein Complexes. Macromolecular Systems, previously in the D12 tree, has been replaced by Macromolecular Substances.

Protein Indexing
Large numbers of Supplementary Concept Records (SCRs) that represent individual, organism-specific proteins are new in 2005 MeSH. Indexers will look for the most specific protein terms when indexing. They will create SCR flags when encountering an organism-specific protein not found if the protein is from one of the MeSH-designated model organisms: human, mouse, rat, Drosophila, Xenopus, S cerevisiae, S pombe, E coli, Zebrafish, C elegans and Arabidopsis.

An SCR flag is also created when a protein not found in the indexing system (DCMS) is considered biomedically important such as proteins directly involved in pathogenesis and those used as therapeutic agents or as diagnostic reagents. All other proteins will be represented by coordination of a MeSH protein descriptor class and a MeSH organism class. The combination of additional vocabulary and extra emphasis during indexing will provide even greater search retrieval for literature in this area.

Historical Events - Category K
In Category K, descriptors were added or replaced for consistency for information about major historic events and eras:

Support Tags
The MeSH Heading check tags reflecting grant support have been changed for 2005. Changes were made because the former name of the descriptor was a less accurate label for the concept. The concept is support of research, not support in a general sense. The changes are as follows:

2004: Support, Non-U.S. Gov't
2005: Research Support, Non-U.S. Gov't

2004: Support, U.S. Gov't, P.H.S.
2005: Research Support, U.S. Gov't, P.H.S.

2004: Support, U.S. Gov't, Non-P.H.S.
2005: Research Support, U.S. Gov't. Non-P.H.S.

[Editor's Note: Please see MEDLINE® Data Changes - 2005. NLM Tech Bull. 2004 Nov-Dec;(341):e9 for details on MEDLINE data changes.]

[Editor's Note added on December 27, 2004:
The MeSH Home page has been updated with the 2005 Introduction to MeSH including the New 2005 Medical Subject Headings, Alphabetic List; Changed Descriptors - 2005; Deleted Descriptors - 2005; and New 2005 MeSH Headings, by Tree Subcategory.]

By James Pash, PhD
and
By Jacque-Lynne Schulman
MeSH Section

Pash J, Schulman J. What's New for 2005 MeSH^®. NLM Tech Bull. 2004 Nov-Dec;(341):e8.