Part of The International Journal of Psychiatry - ISSN 1359 7620 - A trade mark of Priory Lodge Education Ltd

psi1.gif (3050 bytes)   globe4.gif (9321 bytes)Nline.gif (2767 bytes)barrabr.gif (6829 bytes) Evidence-Based Psychiatry - Psychiatry On-line Brazil (3) 10 1998

Evidence-Based Psychiatry:

coordination: Dra Ana C Chaves

Versão em português


Searching Medical and Biomedical Issues on Internet:
Different Resources Available

Antonio Carlos Lopes*

* Psychiatry Resident, Escola Paulista de Medicina,
Federal University of São Paulo - UNIFESP.


You and your friend were designated to give two seminars on Alzheimer disease: one for experts in this area; one for the general public. At last, you have made up your mind that you need a computer to search for specific articles somehow related to this topic. You both approach your local medical library. Your friend knows just a little bit more on computers than you. So you enter a long waiting queue to the library's off-line computers, where a MEDLINE access on various CD-ROMs are available. Your friend prefers to simply play with a nearby PC connected to the Internet, used by no one at that time.

One hour later, you have only performed a MEDLINE search for the last five years on the first CD-ROMS. The local librarian is billing you for the excessive time and number of citations saved in your diskette, while people behind are sniffing at you. The best that you can do is stop and complete the search some other day. To your surprise, when you approach your friend, he has already completed the whole MEDLINE search since 1966, an e-mail message was sent to a famous specialist on Alzheimer diasease, family self-help pages on the Internet have been discovered and now he is just reading the latest issue of the BMJ! Definitely, you feel like you are demented!

This may look like a joke, but it might have happened to any of us. Nowadays, the vertiginous expansion of Internet resources have provided powerful tools for the medical/biomedical researcher. Most of them are still unknown to the majority of computer users. From searching the MEDLINE, to discovering someone's address, or just reading the latest issue of a medical journal, a wide variety of resources are available, provided that we learn to use the right tools for the right purposes.


ball12.gif (924 bytes)InterNOT MaDLINE!


In the past, MEDLINE could only be assessed at some few local medical libraries, where it had been licensed for use by the National Library of Medicine (NLM). However, in the last few years, MEDLINE has been made available at different Internet sites, at first charged, and more recently on a free basis. One of the most popular sites are NLM's PubMed and Grateful Med pages. They both offer free access to references and abstracts of MEDLINE and other MEDLINE-related databases, as well as charged delivery of full text of articles. They are organized in such a way that you can your search for specific topics, from MeSH terms, to text words, title words, authors' names, publication type, journal name, etc. You can search the whole database range (from 1966 on), or choose specific periods of time (the last five years, for instance). Specific citations can also be tagged, so that you can read their abstracts later on.

Some organizations have also licensed the use of MEDLINE (such as SilverPlatter or Ovid), selling and distributing MEDLINE CD-ROMs, or developing charged Internet pages. Moreover, a growing number of sites now offer access to MEDLINE on Internet, using specific softwares, or just mirrors of NLM's MEDLINE access (see Table 1 and Table 2). Some require  previous registration for use; some are password-protected. There are both charged and free Internet MEDLINE services. Depending on the page, different databases can be assessed. Most sites also offer full text of articles by paying a fee. On the other hand, you should carefully choose a good Internet MEDLINE service, for the same search, performed at different MEDLINE sites, may yield different results. Various MEDLINE search softwares and specific MEDLINE updating frequencies might explain these differences. While some vendors may update MEDLINE records as frequently as once a week, others would have them updated every 6 months or a year (Sikorski & Peters, 1997).

Some other broad or specific databases, like  EMBASE (the European counterpart to MEDLINE), or the Cochrane Library, have their access centralized at some few charged Internet pages (like BMJ, and at the Cochrane Collaboration, respectively).


ball12.gif (924 bytes)Spiders, robots, crawlers and mouses


Certainly most of us must have got entangled in the world wide web someday. We usually know exactly what we hope to discover on Internet, but no idea where to find it. From general medical news or guidelines, to patients' self-help organizations home pages, and even somebody's e-mail or home addresses, information on Internet can be yielded quite easily with the help of the called "search engines". They encompass different free sites on Internet, where you can search for specific topics distributed throughout the net, home page addresses, lists of organizations sites, major public interest pages, etc. Different search engines have been devised around the world, yielding different kinds of data. Search engines intercept different new pages on Internet with the help of some programs, termed "spiders", "robots" or "crawlers". These programs explore the whole net periodically, searching for every recently added home pages, links, etc. The frequency of this search varies from site to site. Some, like AltaVista, refresh their databases as soon as every 24 hours. Others remain months without a single new search. Of course, they are neither perfect, nor so comprehensive. Some would only look up new home page names; others do explore the whole text of entire pages, indexing every word found. Some specific search engines have become famous for their scope and wide use, like Yahoo, AltaVista, Hot Bot, Excite, Lycos, Infoseek, etc. (Table 3). What such weird creatures!

Search engines can be classified into two main groups: those with hierarchically organized and those with non-hierarchically organized search methods. In the first group, topics are ranked in a hierarchically decreasing order, from the most widely used terms, to more specific matters. For example, if you want to find where Harvard University's home page is located on the web, a search engine like this would probably first look for a list of universities throughout the world, then find a list of universities in the United States, and finally discover where Harvard University's page is located. All you have to do is to click on the page's address shown, and you will automatically enter Harvard's site. Yahoo and Excite are examples of such search engines. Advantages: they generally yield precise searches, listing only the most relevant sites directly related to your topic of interest. Disadvantages: very specific topics may not be found.

If you want to find very specific subjects on the net, or if you need to list the highest number of pages on Internet where a topic was cited, you had better use a non-hierarchically organized search engine, where every single word, in every page, is indexed. AltaVista is a good example of such an engine. Suppose you are searching for texts related to Capgras syndrome (a rare delusional psychiatric condition) on the web. Probably there will be few (if any) texts available. A non-hierarchically organized search engine might possibly fetch the greatest number of web pages where this syndrome was cited. Furthermore, you can also find some other useful data, like someone's e-mail address. You just have to type somebody's name (sometimes between brackets), and click the "search" button.  Advantages: an extensive search is performed, and the greatest number of sites are yielded. Disadvantages: there may be too much irrelevant  information, with no relationship to your search needs.

If you need to send a letter or an e-mail message to somebody whose address you ignore (for example, the main author of an article), some Internet engines will also help you with this job. BigFoot, WhoWhere and other sites (see Table 4) provide searching for home addresses, e-mail accounts, contact telephone numbers of people or organizations and even road maps (especially those in the USA).

In Brazil, you can find some few search engines with different scopes (Table 5). Cadê?, for instance, is a hierarchically organized search engine quite similar to Yahoo. For more specific searches, you might make use of Bookmarks. Radar UOL also offers extensive searches. It is worth mentioning the good meta-crawler engine called Miner. Meta-crawlers are Internet sites capable of performing a search, at the same time, at different search engines, outputting a result which is the combination of all search engines' results.  Miner provides access not only to international or Brazilian general search engines, but also to some specific medical search engines, software search engines, etc.

Most countries in the world are developing regional coverage search engines. A wide list of search engines, organized according to different countries, is shown in Table 6.


ball12.gif (924 bytes)Medical search engines and medical-related sites


Although Internet provides resources to search the MEDLINE database, to discover a home page in amidst the web, or as means to finding out someone's address, your main interests might be more focused, or less sophisticated. Some people just intend to read the latest medical news or continuing medical education (CME) articles. Your patient might appreciate some general medical information on his illness, or contact a patients' self-help site.

Some Internet pages provide these kinds of data. They may comprise medical search engines, or broad medicine related sites. Some are oriented for the clinician, being divided into specialty sections. Others will offer links to major medical associations, on-line medical journals, patients' self-help groups and the like (see Table 7 and Table 8). Radiology imaging databases, CME courses, live Internet broadcasted real-time medical conferences, surgeries videos, etc., are just beginning to be used as new technologies.

Can you understand now why your friend is so smart?


Table 1 - Main free MEDLINE access sites available on Internet
MEDLINE Resource Centre, 1998).


Site Name





NLM's Internet Grateful Med


Healthgate MEDLINE +

MEDLINE + 6 other databases








MEDLINE, AIDSDrugs, AIDSLine, AIDSTrials and Outlines in Clinical Medicine


"Evaluated MEDLINE"


Cross-search OMNI and MEDLINE


Table 2.    Main charged MEDLINE access sites available on Internet
MEDLINE Resource Centre, 1998).


Site Name



MedGate Access Plan


Community of Science

Various charges based on size of institution






MEDLINE, AIDSLINE, CANCERLit, Bioethics Line and HealthSTAR


MEDLINE plus many others databases priced individually


part of Physicians Home Page service
Costs vary, basic subscription is (US)$19.95/month


Table 3.    Main search engines on Internet.


Search engine

Internet address






Northern Light




Table 4.    Main e-mail/domains search engines.


Site name

Internet address

Domain Name

World Email




Find ME-Mail


Internet Address


Yahoo! (phone/address)

Yahoo! (email addresses)

MIT's Finger



Who's Online?

Who's Who Online

Ahoy! The Homepage

InfoSpace Accumail

Search! Personal Pages


Table 5.    Main Brazilian search engines.


Search engine

Internet address








Table 6.    Some country-specific search engine addresses.



Internet address














Latin America


New Zealand







United Kingdom (UK)

United States of America (USA)

World wide engines links


Table 7.     Different medical-related sites on Internet.


Site name

Internet address

Computer in Mental Health (CIMH)


Doctor's Guide

Emergency Medicine

Health Services and Public Health Sites on the Internet Organized by Site Name

Mental Health Net

Medical Matrix

Myron Pulier home's page

Oxford & Anglia Mental Health Web


Table 8.     Some important online medical journals on Internet.


Journal name

Internet address

American Journal of Psychiatry

Annals of Internal Medicine

Archives of General Psychiatry

British Medical Journal

Canadian Medical Association Journal

Journal of the American Medical Association (JAMA)

Journal of Neuroscience

The Lancet


The New England Journal of Medicine



ball12.gif (924 bytes)References


Sikorski R, Peters R. Medical literature made easy - Querying databases on the              Internet. JAMA 1997, 277(12):959-60.


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