MEDLARS Data Bases

The Toxicology Information Services at the Karolinska Institutet 1n Stockholm, Sweden, publish a monthly bulletin entitled Teratology Lookout. This excellent source of references of interest to experimental teratologists and clinicians is compiled by an advisory panel. The secondary sources Biological Abstracts, Biological Abstracts/RRM, and Chemical Abstracts and the MEDLARS data bases are scanned by the use of computer profiles to spot pertinent material. Keywords have been added to each reference, and most references include author addresses. The contents are divided into seven... 

Bibliographic Retrieval Services (BRS) The Bibliographic Retrieval Services, Inc. of Scotia, New York also offer efficient access to several data bases that are relevant to chemical industry needs. BRS offers an on-line version of Chemical Abstracts CA search under the file label CHEM. Often a CHEM search can be supplemental with other BRS data bases. One can use the CROS file, which provides an index to all data bases on-line at BRS. BRS data bases include NTIS, Science SCISEARCH Citation Index, the Smithsonian Information Exchange (SMIE), and BIOSIS Previews. All are described in the previous section. A few of the MEDLARS data bases are available from BRS, as well as a data base called Pharmaceutical News Index that covers drug industry news. 

Costs—Recent charges for MEDLARS data bases have been as follows ... 

Non-Commercial Search Services Among the noncommercial purveyors of search services are institutional and university-run research centers. The fees charged by these institutional search services vary from vendor to vendor, but are usually reasonable. These charges are in addition to the above-listed costs for MEDLARS on-line. All of these search services access MEDLARS data bases. Some of them also access other commercial data bases (Lockheed, SDC, BRS, etc.) and may provide other services. The Franklin Institute in Philadelphia, Pa., for example, provides annotated search print outs, obtains all relevant articles cited in the search, and also provides transactions where necessary. 

FIND, S.V.P. located at 500 Fifth Avenue in New York, New York is probably the best-known search service in the U.S. They will do an individual search using three MEDLARS data bases for approximately 300.00- 350.00 (depending upon the length of the search). For this amount, the customer receives off-line print outs that have been reviewed and highlighted by a FIND staff member, as well as copies of up to five articles cited in the search. They search other type of data bases and will answer all types of reference questions. 

MEDLARS Data Bases—For further information on the data files cited and on NLM on-line training programs contact National Library of Medicine, 8600 Rockville Pike, Bethesda, Maryland 20209, Telephone (30D-496-6193. 

CANCERLINE, the acronym for Cancer Information On Line is another MEDLAR data base. Sponsored by the National Cancer Institute, it consists of three files ... 

The inverted search process, in conjunction with modern developments in computing, lends itself to on-line information retrieval. The librarian-information officer, or even the scientist himself, sits at a typewriter terminal connected, over telephone lines, to the computer. He explores the dictionary, establishes the search formulation, and then the computer searches for the references and prints them out before his eyes. In the USA this service is known as MEDLINE and is the main means of access to the MEDLARS data base. Various experimental services of this kind are in operation at European MEDLARS centres, but the relatively higher cost of telephone communication here makes it more expensive than batch searching. 

Offers direct access to virtually all of the world s scientific and data bases for toxicology and related information. Covers chemicals, pesticides, food additives, industrial chemicals, heavy metals, environmental pollutants, and pharmaceuticals. The Center is online to more than 400 computerized databases, including DIALOG, MEDLARS, STN International, ITIS, and DROLS. It performs searches for outside users for a fee. 

MEDLINE (MEDlars on-LINE), NLM s on-line data base on the medical literature of the world, indexes its entries by use of MESH (MEdical Subject Heading) terms, which is a controlled vocabulary. When searching on-line, terms entered default to the MESH heading index unless a modifier specifies that another index is searched. The following MESH headings are useful for finding teratology information on MEDLINE ... 

In 1981 a new list with 86 additional substances became available (ref. 8). The computer search of the RTECS was reasonably straightforward at that time. The key word "teratogen" was used and the RTECS data base searched for the names of compounds under this classification. The size of the printed file was reasonable (500-600 entries). A copy of the file could be posted in the laboratory, with a short explanation that the list of teratogens should be viewed with caution due to the fact that data from the RTECS are unevaluated and that uncertainties exist about animal-human extrapolations. Any librarian having access to NLM-MEDLARS (National Library of Medicine-... 

In a second generation of MEDLARS, which is planned for implementation this fall, it will be possible, with the aid of the data base established through the Chemical Abstracts registry system, to index biomedical publications with many more specific terms and chemicals than has been possible under MEDLARS I. While it is not projected that this extensive listing of chemical compounds be included in Index Medicus, it will be possible to provide such listings in other MEDLARS products. Thus a current publication of the Library, the Toxicology Bibliography, will list the biomedical literature by any desired chemical classification. 

Commercial Services A growing number of commercial search services provide on-line access to many data bases in addition to MEDLARS. Some of these commercial services can obtain almost any type of information for you. The costs tend to be quite high, but the vendors will remind you that you get what you pay for . Since the competition for clients is great among commercial service vendors, their marketing is often aggressive. A client can, however, often obtain extensive personalized service from a commercial service. Space does not permit a description of all the commerical search services available. As an example, however, one or two commercial services can be examined. 

The National Library of Medicine (NLM) has its own data systems network. Under NLM s MEDLARS program, a number of data bases on toxicological and health effects of chemical substances are now available. One very useful data base is TOXLINE, which stands for Toxicology Information On-Line. Full information on TOXLINE and other data bases within the NLM MEDLARS program can be obtained by contacting MEDLARS Management Section, Specialized Information Services, National Library of Medicine, 8600 Rockville Pike, Bethesda, Maryland 20209 [(301) 496-6193], or (800) 638-8480. 

Toxicology Data Bank is another on-line interactive retrieval system offered by the National Library of Medicine (NLM) as part of the MEDLARS family of data bases. It provides information on 2500 chemical substances, extracted from 80 reference books and journals. 

Other databases supplied by NLM are the Hazardous Substance Data Base (HSDB), the Registry of Toxic Effects of Chemical Substances (RTECS), and the Medical Literature Analysis and Retrieval System (MEDLARS). NLM also supplies other specialized databases called CANCERLIT, DART, GENETOX, IRIS, CCRIS, and CHEMID. 

In addition to retrospective searches of the data base, most MEDLARS cen-... 

Sources of information that can be accessed for evaluating products include the Hazardous Substances Data Base, which contains a summary of the fate of the substance in the environment and can be accessed via MEDLARS (Medical Literature Analysis and Retrieval System) [a.405], the EPA AQUIRE (Environmental Protection Agency-Aquatic Life) data base, which contains a listing of aquatic toxicity data for many industrial chemicals [a.406], Syracuse University s data base of fate studies [a.407], and quantitative structure-activity relationships (QSARs) such as the EPA programme ECOSAR (Ecological... 

Indexing policy. It is our policy to index only that information in a paper relevant to our product. We do not index the whole content of a paper, as MEDLARS would, but rather the narrower range of information about our product. The primary advantage of this approach is that we can eliminate many false drops that occur whc n we search the "global" data bases. 

---