Using Case Studies to Teach Content in an Introductory Biochemistry Course Kathleen Cornely Department of Chemistry and Biochemistry Providence College Providence, RI 02918 This slideshow is posted on my website at http://www.providence.edu/chm/kcornely/Casebook.htm
Why use case studies? • The case study method involves teaching scientific theory and content in a framework that students can relate to in their own world. • Students develop analytical problem-solving skills and higher-order thinking skills. • Students practice oral and written communication skills. • Uses collaborative/cooperative (rather than competitive) learning strategies. • Involves ambiguity.
Why use case studies? • The intellectual exercises carried out by a student engaged in case-study analysis are similar to the activities of a research scientist. • These exercises are good preparation and training for students who wish to be scientists.
Why use case studies in biochemistry? “The difficulty of engaging learners in the processes and problems of science is most likely to occur in the first year courses dealing with fundamental topics, as the learners are not yet prepared to perceive the relationship between these topics and the practice of their careers.” Rivarola, V., and Garcia, M. B. Biochemical Education28 (2000), p. 30-31.
Three types of biochemistry case studies • Metabolic case studies • Inborn errors of metabolism • Analysis of “real” scientific data • Taken from introductory biochemistry concepts found in the current literature • Case study projects involving current events • Thalidomide • Genetically modified foods (Ann Taylor, Wabash College) • Olestra • Anthrax
1. Metabolic case studies • Each case describes the symptoms of a patient who is under the supervision of a physician. • In most cases, the disease suffered by the patient is an “inborn error of metabolism”; ie a particular enzyme in a metabolic pathway is deficient or nonfunctional. • Students diagnose the patient and determine the missing enzyme; explain why the enzyme is responsible for the observed symptoms.
Goals and limitations • Goals • Provides an exercise which will allow the students to synthesize information regarding intermediary metabolism. • Show how analytical problem-solving strategies are used in a clinical situation. • Limitations • It’s difficult to find such exercises for the other content areas covered in the course.
Expand the case study method • Use the case study method throughout the course, not just during the study of intermediary metabolism. • Concerns • Where do I find such cases? • Would using the case study method detract from covering essential content area in biochemistry?
The “process vs. content” debate • Core knowledge… • Boyer (BAMBED28 (2000), pp. 292-296) has suggested a list of “core topics” that should be covered in an intro biochemistry course. • Or core skills? • Ross Feldberg (BAMBED29 (2001), pp. 222-224) suggests that instructors make up a skill set. • Then address how each topic contributes to the acquisition of that skill.
One man’s skill set • How to carry out quantitative calculations related to pH, buffering, spectrophotometric analysis, kinetics, dilutions and thermodynamics. • How to place the various topics covered into an overall context. • How to understand and evaluate the nature of scientific evidence. • How to read scientific literature to learn more about specific topics. • How to read a biochemistry textbook. Feldberg, R., Biochemistry and Molecular Biology Eduation29 (2001) 222-224.
“Content” or “directed” case studies • First described by physiologists Cliff and Wright (Am. J. Physiol. 270: S19-S28 (1996)) • They wrote clinical cases designed to teach students basic principles of anatomy and physiology. • The cases were built around very specific learning objectives, rather than being open-ended. • Questions are straightforward and emphasis is on information that is available to the student. • The case study method is used as an alternative to the lecture to convey scientific content to the students. • Some instructors are reluctant to use the case study method because they feel that doing so would decrease the amount of coverage of the material.
2. Analysis of “real” scientific data • Use the biochemical literature to write “case studies”, or problem sets that ask the students to analyze scientific data. • The case study is used as a vehicle to convey content; at the same time, students develop higher-order analytical problem-solving skills.
3. Case study projects • These types of case studies follow the format suggested by Clyde F. Herreid. • Case studies were traditionally used in business and law; in 1997 Herreid published an article in JCST and encouraged scientists to do the same. • Case studies are “stories with a message”. • Case study problems involve class discussion; instructor guides students toward the solution of a problem. • “The goal of the case study methods is not so much to teach the content of science (although that does happen), but to show how the process of science works.”
Case study projects: “Content and conflict” • Cases are used to convey scientific principles to biochemistry students. • The issues chosen also involve a conflict that the students must grapple with. • The case studies described here are timely—they address issues currently in the news. • FDA approval of thalidomide • The use of Olestra as a fat substitute • Genetically modified foods (Ann Taylor) • The “anthrax scare” of 2001
Case teaching method • Students are given the following materials: • A fictional “story” describing characters on different sides of the dilemma posed in the case study. • Scientific background information about the topic. • Copies of relevant papers and web site references. • The class is divided into three groups—each “interest group” has a certain point of view. • Students read papers and are given specific questions to answer from the point of view of their assigned interest group. • Evaluation • Students hand in written answers to questions posed in the case study. • Each group prepares a short presentation to the class using the point of view of their interest group. • There is time allowed for class discussion. Students are given grades for their participation.
Thalidomide makes a comeback • Case Synopsis • An FDA official must decide whether to shut down buyers’ clubs which imported thalidomide from foreign countries and dispensed it to their members for the treatment of AIDS. • AIDS activists were pressuring the FDA to approve thalidomide, since it had shown promise in the treatment of AIDS and cancer. Bennett, N., and Cornely, K. J. Chem. Educ. 78 (2001), p. 759-761.
Thalidomide makes a comeback • Description of interest groups and assignments • Scientific consultants to the thalidomide victims • Draw R/D enantiomers of thalidomide. • Analyze teratogenicity of the pure isomers and a racemic mixture. • Medical researchers • Deduce the role of TNF-a in HIV. • Assess role of thalidomide in changes of TNF-a. • Drug designers • Write mechanism for the acid hydrolysis of thalidomide. • Assess ability of chemical analogues to inhibit TNF-a. production. • Design analogues that will effectively TNF-a production.
Thalidomide makes a comeback • Class discussion—issues to address • Who is this case of importance to, and what are their interests? • Is thalidomide effective for the treatment of AIDS and cancer? • What is society’s responsibility to thalidomide victims? • Is it possible to design a distribution protocol that is entirely risk-free? • Should the FDA official use her authority to shut down the buyers’ clubs?
Is Olestra an effective weight loss aid? • Case synopsis • Olestra was approved by the FDA after a very lengthy and expensive study process. • The FDA required Proctor & Gamble to place warning labels on Olestra-containing food packages, and to monitor possible ill effects suffered by users of the product. • There are groups (most notably the Center for Science in the Public Interest) and individuals who oppose the use of Olestra and would like the FDA to rescind its approval of this food additive.
Is Olestra an effective weight loss aid? • Description of interest groups and assignments • Proctor & Gamble scientists • Explain why the Olestra formulation was changed from liquid sucrose polyester (SPE) to a semisolid form. • Analyze biophysical data of different forms of SPE. • FDA Scientists • Analyze plasma values of lycopene and b-carotene in control and Olestra-fed volunteers. • Address the addition of fat-soluble vitamins to Olestra-containing products. • Consumer groups • Discuss FDA approval process. • Address issues of concern to consumers for this food additive.
Is Olestra an effective weight loss aid? • Class discussion—issues to address • Describe the chemistry of Olestra and the physiology of the fat digestion process. • Is physical discomfort a serious problem for Olestra users? Is vitamin depletion? • What issues did the FDA need to address in its approval process? • Is Olestra safe? • Will the use of Olestra really help individuals lose weight?
The “anthrax scare” of 2001 • Case Synopsis • Following the terrorist attacks on the World Trade Center and the Pentagon, a number of organizations and individuals were the targets of bioterrorism involving weaponized anthrax contained in letters. • Scientists have yet to conclusively identify all of the strains involved. • The response by public health officials was inadequate. • Antibiotic prescription by physicians and use by many individuals was almost certainly inappropriate in most cases.
The “anthrax scare” of 2001 • Description of interest groups and assignments • Microbiologists • Describe the mechanism of antibiotics in general and Ciprofloxacin in particular. Address the ramifications of large-scale antibiotic therapy. • Address issues concerning vaccinations. • Biochemists • Interpret experimental data from Nature Biotechnology (2001) 19, 958-96 in which a polyvalent inhibitor of the anthrax toxin was designed. • Describe why antitoxins are preferable to antibiotics. • Geneticists • Design various protocols—for example, how to prepare a library for one of the anthrax plasmids. • Assess the effect of mutations of various toxin proteins.
The “anthrax scare” of 2001 • Class discussion—issues to address • Detailed biochemical mechanism for anthrax infection. • Using what you know about the mechanism, how would you design drugs to treat anthrax-infected individuals? • What are the responsibilities of (a) physicians and (b) the public concerning antibiotic use? • What kinds of measures should be put in place to prevent bioterrorist attacks? What should be the appropriate response when the attacks do occur? • Is the attention paid to these issues appropriate?
Summary • Well-designed case studies can convey scientific content as well as addressing societal issues. • The instructional goals of the case study exercises were met by the students. • Written work was of high quality. • Oral presentations were well-researched and effectively delivered. • Students report a high level of enjoyment of the case study exercise.
Summary ‘Instructors reflect on the teaching-learning process and design new problems that exercise their students’ higher order thinking skills as well as their own.” White, H. B. BAMBED28 (2000) P. 211.
Metabolic case studies—resources • Scriver, C. R., Beaudet, A. L., Sly, W. S., and Valle, D., eds. (consulting eds. Stanbury, Wyngaarden and Fredrickson) The Metabolic Basis of Inherited Disease, 1989, McGraw-Hill. • Montgomery, R., Conway, T. W., and Spector, A. Biochemistry: A Case-Oriented Approach (1990), The C. V. Mosby Company, St. Louis. • Devlin, T. M. (ed.) Textbook of Biochemistry with Clinical Correlations (1992) Wiley-Liss, NY. • Halperin, M. L., and Rolleston, F. S. Clinical Detective Stories: A Problem-Based Approach to Clinical Cases in Energy and Acid Base Metabolism (1993) Portland Press, London. • Ludueña, R. F. Learning Biochemistry: 100 Case Oriented Problems (1995) Wiley-Liss, NY. • Higgins, S. J., Turner, A. J., and Wood, E. J. (1994) Biochemistry for the Medical Sciences: An Integrated Case Approach, Wiley and Sons, NY. • Glew and Ninomiya. Clinical Studies in Medical Biochemistry (1997), Oxford Publishing. • Write your own using The Metabolic Basis of Inherited Disease (ed Stanbury, Wyngaarden and Frederickson), McGraw-Hill, as a resource.
Analysis of scientific data—resources • Cases in Biochemistry”, published in 1999 by John Wiley & Sons, has been updated and can be found at http://www.providence.edu/chm/kcornely/Casebook.htm • Jozsef Szeberenyi regularly publishes these types of exercises in Biochemistry and Molecular Biology Education; these are in multiple-choice format.
Case study projects—resources Hal White has compiled a list of articles published in Biochemistry and Molecular Biology Education (formerly Biochemical Education) and has posted the citations on his web site: http://www.udel.edu/chem/white/teaching/BiochEd/articles.html
Case study projects—resources • Clyde Herreid and Nancy Schiller have compiled a list of case studies developed at their annual case-writing workshops held at University of Buffalo. http://ublib.buffalo.edu/libraries/projects/cases/case.html • P. K. Rangachari of McMaster University has posted several of his case studies on his web site. http://www.fhs.mcmaster.ca/pbls/writing/
Interested in other cases? • Case-study and problem-based learning exercises are regularly featured in columns in these journals: • Biochemistry and Molecular Biology Education (BAMBED) • Journal of College Science Teaching • Journal of Chemical Education
Have you written your own cases? • Submit to the above-mentioned journals and web sites. • Consider publishing on BioMolecules Alive, the new ASBMB and BEN-sponsored digital library.