The Role and Value of the Basic Sciences in Medical Education (with an Emphasis on Biochemistry)

Intoduction

When Abraham Flexner began his evaluation of the medical schools in the United States and Canada in 1908, there were three different ways in which a student could receive training to be a physician: 1) apprenticeship with a practicing physician, 2) through a proprietary medical school, or 3) by a university-based medical school and associated hospital.¹ The publication of Medical Education in the United States and Canada (commonly referred to as the Flexner Report) in 1910 criticized the lack of science content and application of the scientific method in teaching diagnosis and treatment.² This resulted in the reform of medical education in the United States through the adoption by the Council on Medical Education in 1905 of the standard adopted that medical students would have two years of education in the sciences of human anatomy and physiology and two years of clinical training in a teaching hospital.³ The implementation of this reform was completed in the 1930’s.¹

The sciences that constitute the foundation of medical practice

Since the time that scientifically-based medical education became the standard for training physicians, there has been an exponential increase in the scientific knowledge that a physician must understand and apply to diagnose and treat patients competently. In addition to training in human anatomy and physiology during the first two years in medical school, a present-day medical student also receives instruction in biochemistry, cell biology, embryology, epidemiology, genetics, histology, immunology, microbiology, molecular biology, neurobiology, nutrition, pathology, pharmacology and virology. These foundational or basic sciences enable the future physician to understand what constitutes the homeostasis of the healthy individual, the mechanisms by which that homeostasis is disrupted by disease, and how particular disease states may best be treated. A competent physician will be able to apply concepts from these foundational sciences and integrate new scientific knowledge and technology to rationally solve clinical problems presented by patients.

With new discoveries and advances in the foundational sciences increasing every year, the challenge for medical educators is to discern which of these advances together with current knowledge will help the medical student relate the foundational sciences to medicine and clinical practice. A recent study by the Association of American Medical Colleges and the Howard Hughes Medical Institute described the competencies in the foundational sciences that a physician entering residency should possess in order to be able to practice medicine grounded in scientific principles.⁴ The report emphasized the importance of the natural sciences in medical education but also stressed that they should be presented in a way that students recognize their relevance to medical practice. These competencies, along with the accompanying learning objectives in the report, will serve as an excellent guide in helping medical educators present the scientific concepts that will prepare the medical student to practice science-based medicine.

The value and role of the foundational sciences in medical education

The ultimate goal of all of the foundational sciences is to prepare the student to take the greatest advantage of clinical experience available in their medical training. Regardless of their separate venues, foundational science education and clinical training are characterized by an extensive interdependency. The foundational sciences provide a high quality learning experience when they are correlated with clinical problem solving challenges. Likewise, clinical training becomes a high quality learning experience when it is fully supported by the foundational sciences.

The discipline of Biochemistry is but one of several foundational disciplines that describe the elements that compose the body and mind, how those elements function and how that function is regulated to maintain health. These disciplines further prepare the student to understand how that regulation is disrupted by disease. When effectively integrated with all the traditional disciplines, Biochemistry provides needed insight into the underlying mechanisms of both structure and regulation that occur at the cellular, tissue, organ, and whole system level. Effective integration requires attention to content, proper scaffolding of that content through increasing levels of complexity, and stage appropriate application to clinical problem solving.
Biochemistry plays several roles in the medical curriculum:

• It is a discipline fundamental to learning other
foundational sciences in the medical curriculum;
it provides a vocabulary and a way of
understanding and thinking about that vocabulary.
• It teaches how scientific reasoning can be applied
to clinical decision making.
• It provides direct background for clinical problems that require molecular insights.

Biochemistry is generally introduced early in the medical curriculum because many of the other foundational sciences utilize it. It develops general concepts such as regulatory cycles, signaling pathways, metabolic pathways, and structure/function relationships that serve as metaphors for learning in later courses. Physiology draws upon biochemical concepts to describe intra-and intercellular regulatory pathways, detergent action and enzymatic mechanisms of digestion and absorption, and proteins that function as motors to pump ions. Pharmacology employs concepts in protein-ligand relationships, regulation of synthesis and degradation of signaling molecules, and outcomes of altered regulation of metabolic pathways. Pathology utilizes molecular insights to explain storage diseases, the anatomical and physiological outcomes of vitamin and other nutrient deficiencies, regulation of cell cycle and cell death in the development of cancer, and the molecular explanations related to altered metabolism. Microbiology and immunology use concepts in protein structure in antigen-antibody relationships, active oxygen function in cellular immune response mechanisms, and molecular biology concepts involved in DNA transposition and gene regulation. Neurosciences make use of principles of gene regulation to describe the anatomical changes during neuroplastic adaptation, the biochemistry involved in neurotransmitter metabolism, and pathologic outcomes of membrane defects.

Scientific reasoning serves as the basis for clinical problem solving. It requires a fund of knowledge upon which to base hypothetical possibilities that can be tested. Thus, in its most general aspect, the process of clinical diagnosis is a guess based on the facts available. More precisely, it is a guess that is made more reliable when based on information provided by the foundational sciences. Biochemistry has a role in providing insight into the meaning of the data collected from the patient that concern molecular mechanisms. This involves an understanding of laboratory analysis of blood and other body fluids and an awareness of the possibility of involvement of metabolic pathways, of gene regulation, or of chemical messengers.

The signs and symptoms of disease occur in patterns. Many of these patterns are visible or obtained from the patient’s medical history. Biochemistry contributes to a framework for recognizing patterns and establishing their likelihood as a diagnosis. This framework of molecular structure and function, regulatory relationships, and integration of pathways through which molecules are transformed makes it possible to think more clearly and reliably about clinical problems. Clinical therapeutic solutions are also aided by biochemistry insights because molecular mechanisms translate into physiological effects,
e.g. pushing anti-inflammatory pathways through dietary changes results in a decrease in inflammation.

Incorporation of the foundational sciences into the medical curriculum

In general the foundational sciences should be integrated, both horizontally and vertically, in the medical curriculum and should be taught in a clinical context whenever possible. The vocabulary and core concepts that underpin all of the other courses should be introduced in year 1 and reinforced in year 2. These core concepts should be introduced in a clinical context with problem solving exercises so that the students gain experience applying those concepts to clinical decision making. The clinical years are the most appropriate place for the mastery of the detailed basic science concepts required for a full understanding of the clinical condition and treatment options for the patients with whom the students are working. This education strategy allows the students to appreciate fully the importance of mastering those detailed basic science concepts that most closely relate to patient care. Also, because students are learning these concepts in the clinical framework of a real patient experience they are more likely to retain and be able to apply these concepts in the future.

There are almost as many strategies for achieving horizontal and vertical integration as there are medical schools, but there are some fundamental principles for successful integration that apply to most of the integration models that exist.

In year 1, the primary emphasis for each of the foundational sciences should be on introduction of core vocabulary and concepts and showing the relationship of those concepts to health and disease. In the case of biochemistry, the core concepts are those cited in the above section addressing the value and role of the foundational sciences. The foundational sciences in year 1 should be integrated with each other so that clinical concepts can be introduced in the context of all of the relevant foundational sciences. For biochemistry, the most closely related foundational sciences are cell biology, molecular biology, genetics, nutrition and physiology.

While there are many ways in which integration of the foundational sciences can be organized, successful integration always requires that faculty work with each other in the planning and implementation of integration so that key concepts flow from one lecture to another. Since it is seldom possible for all related lectures to be organized sequentially, it is important that faculty make it clear to the students how the concepts that they cover are linked to others in the curriculum.

Finally, the foundational sciences are best integrated in a clinical context that requires clinical application of the core foundational science concepts. For the didactic portion of the curriculum, this can be achieved by organizing lectures around clinical cases. However, it is also important to involve the students in decision-making processes that utilize core foundational science concepts to solve clinical problems and to do this in an integrated manner to the extent possible. For example, clinical case exercises related to lysosomal storage diseases, glycogen storage diseases, cardiovascular disease and diabetes can be designed to involve core concepts that are associated with biochemistry, cell biology, molecular biology, genetics and nutrition.

The second year curriculum varies widely among medical schools, but it is important that the first-year and second-year faculty work together so that the core concepts from the foundational science curriculum in year 1 are integrated with the second-year curriculum. The first step in this process is an identification of the key concepts from the first-year curriculum that underpin the second-year curriculum. This helps to define those concepts that should be part of the first-year curriculum. It also allows a coordination of the first-and second-year curriculum so that there is appropriate review and expansion of important foundational science concepts in the second year curriculum. It can also be valuable to introduce clinical cases in the first year and revisit them in a more detailed manner in the second year.

Integration of the foundational and clinical sciences is the most challenging in the clinical years because much of the content is taught at the bedside and often at various locations. However, many clinical courses are now standardizing the clinical experience by defining lists of patients that every student must see and procedures that every student must master. In much the same manner foundational science and clinical faculty can work together to identify the key foundational science concepts which are important for student understanding of the clinical learning issues and should require mastery of those foundational science concepts. Typically, this would draw on the foundational science concepts learned in years 1 and 2 that are ideally suited for understanding the disease process being studied, but would go into a level of detail that would be inappropriate for a first or second year course.

From the perspective of biochemistry, examples of foundational concepts linked to clinical learning issues would be lipid metabolism and cardiovascular disease, metabolic regulation and endocrine disorders and metabolic pathways and genetic medicine. Once the key foundational science concepts related to clinical learning issues have been identified there are many ways in which these concepts could be introduced into the clinical curriculum in a standardized manner. Some examples include case presentations, simulated patients, online learning modules or self-instructional modules, but many other strategies have been successfully employed at various medical schools. Finally, it is essential that schools assess the application of foundational science concepts in a clinical context.

Examples of best practices for incorporating the foundational sciences into the medical curriculum

Diversity is a strength in the gene pool and it is a strength in the curriculum. In order for Biochemistry to play a proper role in the curriculum, it needs to be taught through a diversity of modalities that allow its fundamentals to be applied, either in learning more complex concepts or in application to clinical problems. While the traditional lecture has a strength in organizing and communicating facts and concepts, the absence of using that information to make a decision and act on it, e.g. dialog, drawings, reports, prevents the students from using an optimal whole-brain approach.⁵ The temporal lobes that process the information in our long term memory are not designed to postulate possibilities and also make a logical choice among them. A whole-brain approach engages the prefrontal area to perform the latter task and draws on known information thus producing a highly effective use of the whole brain in learning. The modalities of Team-Based Learning and Problem Based Learning are two examples of teaching strategies that employ group problem solving to engage the whole brain including the limbic emotions that result when people work together.^6,7 This metacognitive approach has been recognized in a report by Bransford, Brown and Cocking as one of the three key essential elements for effective education that were identified by the National Research Council.⁸

Many teachers are now also employing active strategies during lecture to better engage the student. The use of hand-held audience response transmitters, “clickers,” permit the instructor to make a formative assessment of the understanding of a concept as it is being taught and a “think-pair-share” method that has students talk briefly with a neighbor in response to a question about the topic being taught are two examples.

If an integration of Biochemistry with the other foundational sciences is to be effective, the integration itself must not be taken for granted. When a metabolic pathway or a signaling pathway is affected by a disease or a drug, then reference should be made to the integrative relationship in addition to the new information presented. This should persist into the clinical training as students discuss their patients during rounds. Also, opportunities for online acquisition of information and collaborative problem solving can help to reinforce this integration. Reports in the research literature do not confine themselves to single disciplines and students working in teams often see different applications of related disciplines to the benefit of the other team members.

Physician competency in the foundational sciences is best achieved when they are integrated with each other throughout the medical curriculum and effectively applied to solve clinical problems.

Prerequisite science components of the pre-medical curriculum

An in depth mastery of the foundational sciences is becoming increasingly important to prepare future physicians for the scientific advances that are rapidly changing the practice of medicine. At the same time there are pressures to shrink the curriculum time devoted to the foundational sciences. Thus, it is absolutely imperative that students enter medical school with a prior exposure to some combination of biochemistry, cell biology, molecular biology and genetics. This prerequisite will introduce undergraduate students to the vocabulary and basic concepts that they will be learning and applying in a more clinical context in medical school. Ideally, this undergraduate prerequisite will also teach students the basics of scientific reasoning. It should be recognized that the coverage of these topics is very uneven at the undergraduate level, so this prerequisite should not be considered as a replacement for these content areas in medical school, but rather a means to make learning in the medical curriculum more effective. Finally, as described in the 2009 AAMC-HHMI report, these topics would be best taught in an integrated manner at the undergraduate level so that students are exposed to the vocabulary and basic concepts of all four content areas equally, and so that the students learn how those content areas are interrelated.⁴

REFERENCES

1. Beck, A.H., STUDENTJAMA. The Flexner report and the standardization of American medical education. JAMA, 2004. 291(17): p. 2139-40.
2. Flexner, A., Medical Education in the United States and Canada. 1910, New York, NY: Carnegie Foundation for the Advancement of Teaching.
3. “Standard now Recommended” and “Ideal Standard”. 1905, American Medical Association Council on Medical Education.
4. AAMC-HHMI, Scientific Foundations for Future Physicians. 2009, Association of American Medical Colleges: Washington, D.C. p. 1-43.
5. Zull, J., The art of changing the brain. 2002, Sterling, VA: Stylus Publishing, LLC
6. Michaelsen, L.K., et al., Team-based learning for health professions education : a guide to using small groups for improving learning. 2008, Sterling, VA.: Stylus Publishing, LCC.
7. Neville, A.J., Problem-based learning and medical education forty years on. A review of its effects on knowledge and clinical performance. Med Princ Pract, 2009. 18(1): p. 1-9.
8. Bransford, J.D., A.L. Brown, and R.R. Cocking, eds. How People Learn: Brain, Mind, Experience, and School. 2000, National Academy Press: Washington, D.C.