his article highlights the additions to several parts of 2001 Medical Subject Headings (MeSH).

A total of 184 headings have been added and ten headings have been deleted. Lists of all new descriptors and the list of deleted and replaced descriptors are posted on the MeSH Web site. The Introduction to the Annotated Alphabetic List 2001 is also posted on the site.

Headings can also be quickly found using the MeSH Browser.

1. New Century

A new century has been added to reflect the Millennium:

History of Medicine, 21st Cent. K1.419.

Events and developments in medicine during the 100 year period following the 20th century.

2. Animal Alternatives

In cooperation with the NIH Office of Laboratory Animal Welfare (OLAW), additions were made in the area of the use of animals and animal models.

Animal Use Alternatives

Alternatives to the use of animals in research, testing, and education. The alternatives may include reduction in the number of animals used, replacement of animals with a non-animal model or with animals of a species lower phylogenetically, or refinement of methods to minimize pain and distress of animals used.

Models, Animal

Non-human animals, selected because of specific characteristics, for use in experimental research, teaching, or testing.

Acute Toxicity Tests

Experiments designed to determine the potential toxic effects of one-time, short-term exposure to a chemical or chemicals.

Skin Irritancy Tests

Tests or bioassays that measure the skin sensitization potential of various chemicals.

Endpoint Determination

Establishment of the level of a quantifiable effect indicative of a biologic process. The evaluation is frequently to detect the degree of toxic or therapeutic effect.

X Endpoint Assay

Previous indexing:

Biological Assay (1980-2000)

Local Lymph Node Assay (LLNA)

The local lymph node assay (LLNA) is an alternative method for the identification of chemicals that have the ability to cause skin sensitization and allergic contact dermatitis. Endpoints have been established so fewer animals are required and less painful procedures are used.

Quantitative Structure-Activity Relationship (QSAR)

A quantitative prediction of the biological, ecotoxicological or pharmaceutical activity of a molecule. It is based upon structure and activity information gathered from a series of similar compounds.

3. A11 - Cells

This vocabulary was reorganized to group the various components of a cell together under Cell Structures (A11.284) and add 27 new cell structure terms.

Myeloid Cells

Myeloid Progenitor Cells

Cellular Structures

Cell Membrane Structures

Cell-Matrix Junctions

Focal Adhesions

Hemidesmosomes

Caveolae

Adherens Junctions

Membrane Microdomains

Cell Nucleus Structures

Chromosome Structures

Euchromatin

Nuclear Pore

Cell Surface Extensions

Chromosomes, Artificial

Chromosomes, Bacterial Artificial

Chromosomes, Mammalian Artificial

Chromosomes, Human Artificial

Cytoplasmic Structures

Stress Fibers

Microtubule-Organizing Center

Cytoplasmic Vesicles

Transport Vesicles

Clathrin-Coated Vesicles

COP-Coated Vesicles

Secretory Vesicles

trans-Golgi Network

4. Vaccine Additions

More than 25 new vaccine descriptors were added to D24 including Anthrax Vaccines, Cholera Vaccines, Diphtheria-Tetanus-acelluar Pertussis Vaccines, and others.

Anthrax Vaccines

Cholera Vaccines

Diphtheria-Tetanus-acellular Pertussis Vaccines

Diphtheria-Tetanus Vaccine

Escherichia coli Vaccines

Lyme Disease Vaccines

Meningococcal Vaccines

Pneumococcal Vaccines

Salmonella Vaccines

Shigella Vaccines

Streptococcal Vaccines

Measles-Mumps-Rubella Vaccine

Vaccines, Contraceptive

Vaccines, Marker

Vaccines, Subunit

Vaccines, Acellular

Cytomegalovirus Vaccines

Herpesvirus Vaccines

Herpes Simplex Virus Vaccines

Marek Disease Vaccines

Japanese Encephalitis Vaccines

Parainfluenza Vaccines

Poliovirus Vaccines

Pseudorabies Vaccines

Respiratory Syncytial Virus Vaccines

Rotavirus Vaccines

Hepatitis A Vaccines

Yellow Fever Vaccine

5. Publication Types

Seven new Publication Types were added. Four are specific to non-journal sources included in the Bioethics, POPLINE, and/or SPACELINE databases. Only two of these seven will be used for MEDLINE indexing prospectively: Evaluation Studies and Validation Studies.

Book Reviews [Publication Type]

used by special data producers only

Critical analyses of books or other monographic works.

Evaluation Studies [Publication Type]

Studies determining the effectiveness or utility of processes, personnel, and equipment.

Fictional Works [Publication Type]

Creative writing, not presented as factual.

Government Publications [Publication Type]

used by special data producers only

Documents issued by local, regional, or national governments or by their agencies or subdivisions.

Textbooks [Publication Type]

used by special data producers only

Books intended for use in the study of specific subjects, containing systematic presentation of the principles and essential knowledge of the subjects.

Unpublished Works [Publication Type]

used by special data producers only

Works that have not been formally published.

Validation Studies [Publication Type]

The processes by which the reliability and relevance of a procedure for a specific purpose are established.

6. Subheadings (qualifiers) Removed

Subheadings that were previously used in cataloging the items in LocatorPlus to characterize the form, geographic location, and language of works were deleted.

Qualifier Type 2 - 213 records for form subheadings

for example: "abbreviations"

Qualifier Type 3 - 382 records for geographic subheadings

for example: "Afghanistan"

Qualifier Type 4 - 104 records for language subheadings

for example: "Afrikaans"

These subheadings have not been used for several years by NLM. For additional information about related changes in NLM cataloging practices, see "Application of MeSH for Medical Catalogers."

Six topical subheadings previously used in cataloging rather than check tags were also deleted. The deleted subheadings are: in adolescence; in adulthood; in infancy & childhood; in middle age; in old age; and in pregnancy.

7. Isoenzymes

Isoenzymes of enzymes will now always be listed as separate supplementary concept records. For example, Lactate Dehydrogenase Isoenzymes and Creatine Kinase Isoenzymes have been deleted as main headings, in order to allow creation of separate supplementary concept records for each of their major isoenzymes.

8. Carcinoma, Pancreatic Ductal

Carcinoma, Pancreatic Ductal has been added in order to allow differentiation of ductal carcinomas of this organ from Carcinoma, Infiltrating Duct and Carcinoma, Intraductal, Noninfiltrating, both of which are only supposed to refer to carcinomas of the mammary ducts.

Comments and Suggestions
Comments and suggestions are welcome. Suggested changes for inclusion in the 2002 version of MeSH need to be submitted to NLM by March 30, 2001.

By Jacque-Lynne Schulman
MeSH Section

Schulman J. What's New for 2001 MeSH. NLM Tech Bull. 2000 Nov-Dec;(317):e4.