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Searching the Literature for Animal Testing Alternatives: A Tutorial

Tutorial for researching alternatives to animal research

Define the Question - Quiz

Dr. X is interested in exploring the effects of caloric intake on the growth of malignant tumors. He has preliminarily chosen to study the differences among brain neoplasms in rats given a range of diets. First, Dr. X needs to perform a literature search to see if there are alternatives to different facets of his research materials and methods. He has picked a variety of keywords to use, some of which are better than others. Can you figure out what the best terms might be?

Select the most correct option by clicking the radio button beside it. Each time you answer a question you will get immediate feedback

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Why should Dr. X write down a list of keywords, including synonyms for major concepts?

It helps him figure out what ideas are particularly important to his research.

Try Again! While writing down the relevant keywords to his search may help Dr. X define what it is he's researching in his laboratory, that is not the real point of the exercise. One hopes that Dr. X already knows the important parts of his research before he gets to the literature searching step.

It's part of the reporting requirement that he turn in a list of keywords.

Try Again! Dr. X will be asked to turn in the keywords and search strategies that he used in each database, but not the complete list of possible terms for his search. The list of keywords is actually useful to his search before he ever gets close to the reporting stage!

Not all databases use the same words to describe the same concepts, so it's important to have different options when searching.

Correct! The keywords list will help Dr. X efficiently search databases with different approaches to indexing articles. Some databases, including PubMed MEDLINE, use a controlled vocabulary to describe all articles, while others depend on free text searching. Some databases focus on the scientific literature, so the technical names for species, titles, and diseases will be emphasized. Others have articles and other publications that use the common names for the same concepts and items.

Using a longer list of keywords means he'll get much better results from his searches.

Try Again! There is a middle ground between only using one keyword for a concept and using every possible word. The first method will probably mean that Dr. X misses some relevant information. The second method may result in a lot of extraneous records that may contain one of his terms, but that use a different meaning for the term. It could also restrict Dr. X's search unnecessarily to add in a lot of similar terms using the "AND" term.


What are some PubMed MeSH terms that may be helpful to Dr. X for his initial literature search? (NOTE: these are all valid terms; MeSH is a search vocabulary specific to PubMed)

"Brain neoplasms"[MeSH], "Muridae"[MeSH], "Energy Intake"[MeSH]

Correct! These three terms are appropriately narrow and relevant to Dr. X's research problem. Using these terms he will find information on studies into the effect of caloric intake ("Energy Intake") on brain tumors ("Brain Neoplasms") in mice and other murids. In this case it is a good idea to expand the species to the family level because laboratory mice, while normally indexed under "Mice"[MeSH], could also be under the "Hesperomyinae"[MeSH] (New World rats and mice). Both terms will be found using "Muridae"[MeSH].

"Biochemical Phenomena, Metabolism, and Nutrition"[MeSH], "Vertebrates"[MeSH], "Neoplasms"[MeSH]

Try Again! All three of these terms are too broad for Dr. X's needs. They will find any information on cancers, cysts, and other tumors in vertebrates (not just mammals, much less murids) that has anything to do with digestion, metabolism, or nutrition. Dr. X needs a more focused set of subject headings for his search.

"Brain Diseases"[MeSH], "Diet Therapy"[MeSH], "Arvicolinae"[MeSH]

Try Again! These terms may sound similar to other keywords that Dr. X could use, but are not actually related to his search. It is important to note the definition of a MeSH term and/or its place in the hierarchy when evaluating the term's utility for a literature search. For example, the "Microtinae" are voles - Dr. X is interested in either the "Hesperomyinae" (New World mice and rats) or "Mice".

"Mice, Transgenic"[MeSH], "Caloric Restriction"[MeSH], "Cerebral Ventricle Neoplasms"[MeSH]

Try Again! These three terms are too specific for an initial literature search on Dr. X's topic. It may be necessary later to restrict the search to find specific types of tumors, using specific strains of mice, or with a specific research protocol (caloric restriction vs. a range of caloric intakes), but at this time Dr. X has not specified any of those conditions.


Of the options below, what are some keywords that Dr. X may find useful when searching databases other than PubMed MEDLINE?

Mus, mice, mouse, murid, rodent

Almost! These keywords describe the test animal, the mouse, pretty completely. If Dr. X wanted to expand his search he could include "Mammals" or even "Vertebrates". Notice that there are both scientific and common names for the mouse included in the list.

This is only one aspect of his search. What other keywords might Dr. X want in his list?

brain, cerebell*, cancer, tumor*, neoplasm*, carcinoma*, glioma* (check database help pages for the applicable truncation symbol)

Almost! In this set Dr. X has specified the organ (the brain or cerebellum) and the disease (cancer, with it's synonyms and related terms) in which he is interested. Notice that there is a mixture of common and scientific terms here, as well as different degrees of specificity with regards to the type of tumor. It may be that Dr. X is specifically interested in a particular type of brain cancer, in which case he would want to add keywords describing the specific type to this list.

This is only one aspect of his search. What other keywords might Dr. X want in his list?

caloric intake, calories, energy intake, diet, food, nutrition

Almost! This list of keywords focuses on the test being done to the mice. Notice that there are a number of different, but related, concepts represented. All of them have something to do with dietary intake. If Dr. X were researching the effects of a calorie-inhibiting drug on the tumors, the common and scientific names of the drug would be good keywords to add to this list.

This is only one aspect of his search. What other keywords might Dr. X want in his list?

All of the above

Correct! All three of the lists give good keywords for a different aspect of Dr. X's research. By compiling a list that contains keywords for the species, the disease/condition, and the treatment/test, Dr. X will find constructing searches for articles that are very relevant to his study much easier.


Dr. X is conducting this literature search to find reduction, refinement, and replacement alternatives to his research methods, so he should use some of the specific keywords for the 3R's in his searches. Which of the below lists will be most helpful to him?

computer aided instruction, teaching models, video, mannequin, virtual reality, cadaver

Try Again! These keywords would be helpful to Dr. X if he were looking for alternatives to animal models for teaching. Since he is doing research, these are probably not the most fruitful options available to him.

insect, bacteria, protozoa, fungus, cell line

Try Again! Since Dr. X is studying a vertebrate organ system, he probably wants to stay with articles that discuss the brain. It is not likely that models based on fungi or insects will be helpful. However, if this were a study of cellular function or toxicity, these invertebrate systems could be relevant.

enrichment, euthanasia, tissue culture, welfare, handling, caging, digital imaging, pain, biopsy, replacement

Correct! The keywords in this list are appropriate for Dr. X's search because they focus on a range of conditions in animal testing that can be altered. These include not only the study of the tumors (cell and tissue culture), but also the welfare of the test subjects (enrichment, handling, caging), and the methods used to track the test progress (digital imaging, euthanasia, biopsy). Before putting together a list of keywords for alternatives searches, it is a good idea to consult the Suggested Keywords page in this module.

All of the above.

Try Again! While all of the keywords listed here are relevant to some animal testing alternatives literature searches, they are not all good candidates for Dr. X's research. Take another look and see if there is one list that is better than the others.

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