Lawrence E. Wineski

Anatomy as the Backbone of an Integrated First Year Medical Curriculum: Design and Implementation

Morehouse School of Medicine chose to restructure its first year medical curriculum in 2005. The anatomy faculty had prior experience in integrating courses, stemming from the successful integration of individual anatomical sciences courses into a single course called Human Morphology. The integration process was expanded to include the other first year basic science courses (Biochemistry, Physiology, and Neurobiology) as we progressed toward an integrated curriculum. A team, consisting of the course directors, a curriculum coordinator, and the Associate Dean for Educational and Faculty Affairs, was assembled to build the new curriculum. For the initial phase, the original course titles were retained but the lecture order was reorganized around the Human Morphology topic sequence. The material from all four courses was organized into four sequential units. Other curricular changes included placing laboratories and lectures more consistently in the daily routine, reducing lecture time from 120 to 90 minute blocks, eliminating unnecessary duplication of content, and increasing the amount of independent study time. Examinations were constructed to include questions from all courses on a single test, reducing the number of examination days in each block from three to one. The entire restructuring process took two years to complete, and the revised curriculum was implemented for the students entering in 2007. The outcomes of the restructured curriculum include a reduction in the number of contact hours by 28%, higher or equivalent subject examination average scores, enhanced student satisfaction, and a first year curriculum team better prepared to move forward with future integration. Anat Sci Educ 4:157–169, 2011.

β‐Agonist‐induced alterations in organ weights and protein content: Comparison of racemic clenbuterol and its enantiomers

Clenbuterol is a relatively selective beta2-adrenergic partial agonist that has bronchodilator activity. This drug has been investigated as a potential countermeasure to microgravity- or disuse-induced skeletal muscle atrophy because of presumed anabolic effects. The purpose of this study was to: 1) analyze the anabolic effect of clenbuterols (-)-R and (+)-S enantiomers (0.2 mg/kg) on muscles (cardiac and skeletal) and other organs; and 2) compare responses of enantiomers to the racemate (0.4 mg/kg and 1.0 mg/kg). Male Sprague Dawley rats were treated with: a) racemic clenbuterol (rac-clenbuterol, 0.4 or 1.0 mg/kg); b) enantiomers [clenbuterol (-)-R or (+)-S]; or c) vehicle (1.0 mL/kg buffered saline). Anabolic activity was determined by measuring tissue mass and protein content. HPLC teicoplanin chiral stationary phase was used to directly resolve racemic clenbuterol to its individual enantiomers. In skeletal muscle, both enantiomers had equal anabolic activity, and the effects were muscle- and anatomic region-specific in magnitude. Although the enantiomers did not affect the ventricular mass to body weight ratio, clenbuterol (+)-S induced a small but significant increase in ventricular mass. Both clenbuterol enantiomers produced significant increases in skeletal muscle mass, while being less active in producing cardiac ventricular muscle hypertrophy than the racemic mixture.

Muscle-Specific Effects of Hindlimb Suspension and Clenbuterol in Mature Male Rats

Anabolic agents are useful tools for probing the mechanisms by which muscle fibers perceive and respond to disuse. β2-Adrenergic agonists exert protective, and/or reparative, effects on atrophying muscle tissue. The effects of one such agent, clenbuterol (Cb), were examined on muscle mass, total protein content, and myofibrillar protein content in selected hindlimb muscles [adductor longus (ADL), extensor digitorum longus (EDL), plantaris (PLAN), soleus (SOL)] of mature male rats, under different loading conditions. Pair-fed rats were divided into four experimental groups: vehicle- and Cb-treated nonsuspended, vehicle- and Cb-treated hindlimb suspended (HLS). Experiments lasted 14 days, during which the rats received subcutaneous injections of 1 mg/kg Cb or 1 ml/kg vehicle. HLS induced significant atrophy in all muscles, except the EDL, in a generally fiber type-related pattern. However, myofibrillar protein content was affected in a more regional pattern. Cb treatment of nonsuspended rats induced hypertrophy in all muscles, in a generally uniform pattern. However, myofibrillar protein content was affected in a more fiber type-related pattern. Cb treatment of HLS rats reduced or eliminated HLS-induced atrophy in all muscles, in a muscle-specific pattern. Overall, the ADL and SOL were most susceptible to HLS-induced atrophy. The PLAN had the greatest magnitude of Cb-induced sparing of atrophy. The results show that, in mature male rats, Cb exerts anabolic effects that are load-dependent and muscle-specific. Responses to this drug cannot be reliably predicted by fiber-type composition alone.

Motor-unit territories in the masseter muscle of infant pigs

In adult miniature pigs (Sus scrofa) fibres of the masseter contract differentially, helping to produce the successive movements of the mandible during the chewing cycle. In infant pigs, however, most fibres of the masseter contract simultaneously. One hypothesis to explain the ontogenetic change in contraction pattern is that the infant masseter is neurologically immature, with large overlapping motor units incapable of producing differential contractions. This hypothesis was tested by mapping the territories of motor units in the masseters of piglets. Filaments from the masseteric nerve were stimulated repetitively; muscle fibres belonging to the stimulated motor units were identified by their failure to react for glycogen. Just as in older pigs, motor-unit territories were found to be very restricted, occupying only a small portion of total muscle volume. Thus, neural organization does not appear to be immature in piglets. An alternative hypothesis, that the ontogenetic change in activity pattern results from growth changes in the anatomy of the masseter, may be a more likely explanation.

Phenoxyethanol as a Nontoxic Preservative in the Dissection Laboratory

In an effort to rid the dissection room of irritating and potentially health-threatening toxic chemicals, we have modified the phenoxyethanol technique for long-term preservation of embalmed cadavers. The new methods employ faster, less toxic embalming and reduced or eliminated phenoxyethanol immersions. Our results are comparable with or improved over those previously described and demonstrate that phenoxyethanol is an excellent, easily manageable alternative preservative to standard formaldehyde/phenol-based embalming fluids.

Distribution and Muscle-Sparing Effects of Clenbuterol in Hindlimb-Suspended Rats

Based on their anabolic properties in skeletal muscles, β-adrenergic agonists are of interest as potential countermeasures to microgravity-induced skeletal muscle atrophy. The levels of clenbuterol (Cb), a β2-adrenergic agonist, in both plasma and skeletal muscle were higher in hindlimb-suspended rats than in their nonsuspended Cb-treated controls. Cb treatment was shown to help maintain the body weight in suspended rats, while reducing the amount of mesenteric fat. However, hindlimb suspension attenuated Cb’s lipolytic effects. In skeletal muscle, the magnitude of response to unloading and Cb treatment followed a general regional pattern and was muscle and type specific. The highest magnitude of response to unloading was in predominantly slow-twitch muscles, and the least responsive were the predominately fast-twitch muscles.

Effect of hindlimb suspension and clenbuterol treatment on polyamine levels in skeletal muscle.

Polyamines are unbiquitous, naturally occurring small aliphatic, polycationic, endogenous compounds. They are involved in many cellular processes and may serve as secondary or tertiary messengers to hormonal regulation. The relationship of polyamines and skeletal muscle mass of adductor longus, extensor digitorum longus, and gastrocnemius under unloading (hindlimb suspension) conditions was investigated. Unloading significantly affected skeletal muscle polyamine levels in a fiber-type-specific fashion. Under loading conditions, clenbuterol treatment increased all polyamine levels, whereas under unloading conditions, only the spermidine levels were consistently increased. Unloading attenuated the anabolic effects of clenbuterol in predominately slow-twitch muscles (adductor longus), but had little impact on clenbuterol’s action as a countermeasure in fast- twitch muscles such as the extensor digitorum longus. Spermidine appeared to be the primary polyamine involved in skeletal muscle atrophy/hypertrophy.

Implementation and modification of an anatomy-based integrated curriculum

Morehouse School of Medicine elected to restructure its first‐year medical curriculum by transitioning from a discipline‐based to an integrated program. The anatomy course, with regional dissection at its core, served as the backbone for this integration by weaving the content from prior traditional courses into the curriculum around the anatomy topics. There were four primary goals for this restructuring process. Goal 1: develop new integrated courses. Course boundaries were established at locations where logical breaks in anatomy content occurred. Four new courses were created, each containing integrated subject content. Goal 2: establish a curriculum management team. The team consisted of course directors, subject specialists, and a curriculum director. This team worked together to efficiently manage the new curriculum. Goal 3: launch contemporary examination and question banking methods. An electronic system, in which images could be included, was implemented for examinations and quizzes, and for storing and refining questions. Goal 4: ensure equitable distribution of standardized examinations and course grading systems among all courses. Assessments included quizzes, in‐course examinations, and National Board of Medical Examiners® (NBME®) Subject Examinations. A standard plan assigned the contribution of each to the final course grade. Significant improvement was seen on subject examinations. Once the obstacles and challenges of integration were overcome, a robust and efficient education program was developed. The curriculum is expected to continue evolving and improving, while retaining full regional dissection as a core element. Anat Sci Educ 10: 262–275.

Clinical Correlations as a Tool in Basic Science Medical Education

Clinical correlations are tools to assist students in associating basic science concepts with a medical application or disease. There are many forms of clinical correlations and many ways to use them in the classroom. Five types of clinical correlations that may be embedded within basic science courses have been identified and described. (1) Correlated examples consist of superficial clinical information or stories accompanying basic science concepts to make the information more interesting and relevant. (2) Interactive learning and demonstrations provide hands-on experiences or the demonstration of a clinical topic. (3) Specialized workshops have an application-based focus, are more specialized than typical laboratory sessions, and range in complexity from basic to advanced. (4) Small-group activities require groups of students, guided by faculty, to solve simple problems that relate basic science information to clinical topics. (5) Course-centered problem solving is a more advanced correlation activity than the others and focuses on recognition and treatment of clinical problems to promote clinical reasoning skills. Diverse teaching activities are used in basic science medical education, and those that include clinical relevance promote interest, communication, and collaboration, enhance knowledge retention, and help develop clinical reasoning skills.

Role of Anatomists in Building an Integrated Medical Curriculum

The anatomical sciences have traditionally included a range of related disciplines and variety of approaches to instruction. Together, they provide a unique opportunity for laying the groundwork for medical curricular integration. Finding a place for regional dissection in a systems-based curriculum-integration scheme has been challenging. However, incorporating regional human dissection into systems-based approaches to histology and embryology can provide a foundation for an integrated basic-science curriculum that preserves medical student exposure to the team-based learning and discovery, and the lessons in professionalism, that traditionally accompany human dissection. This chapter describes steps in curricular development and integration that have led to a unique blend of regional anatomy and organ system structure and function that provides a foundation for the effective practice of medicine from physical examination through diagnosis and medical or surgical treatment. The approach described was initiated by anatomy faculty and involved extensive contributions of the teaching faculty from other basic science disciplines throughout the process. It valued faculty contributions to the pre-existing curriculum and provided a framework for ongoing integration and improvement of student performance.