Dynamic Opportunities for Medical Students to Assume the Roles of "Medical Teacher".

The traditional undergraduate medical education curriculum focuses on bolstering knowledge for practice and building clinical skills. However, as future clinicians, medical students will be tasked with teaching throughout their careers, first as residents and then as attendings. Here, we describe teaching opportunities for students that foster their development as future teachers and potential clinician educators. These offerings are diverse in their focus and duration and are offered across various levels of the curriculum - including course-based learning, longitudinal electives, and extra-curricular opportunities for medical students who have a passion for teaching.

The Effect of Histology Examination Format on Medical Student Preparation and Performance: Stand-Alone Versus Integrated Examinations.

Most medical schools have transitioned from discipline-based to integrated curricula. Although the adoption of integrated examinations usually accompanies this change, stand-alone practical examinations are often retained for disciplines such as gross anatomy and histology. Due to a variety of internal and external factors, faculty at the University of Cincinnati College of Medicine recently began to phase out stand-alone histology practical examinations in favor of an integrated approach to testing. The purpose of this study was to evaluate this change by (1) comparing examination performance on histology questions administered as part of stand-alone versus integrated examinations and (2) ascertaining whether students alter their approach to learning histology content based on the examination format. Data from two courses over a period ranging from 2018 to 2022 were used to evaluate these questions. Results indicated histology question performance initially dropped after being included on integrated examinations. Stratification of students by class rank revealed this change had a greater impact on lower-performing students. Longitudinal data showed that performance 2 years after the change yielded scores similar to previous standards. Despite the initial performance drop, survey results indicate students overwhelmingly prefer when histology is included on integrated examinations. Additionally, students described alterations in study approaches that align with what is known to promote better long-term retention. The results presented in this study have important implications for those at other institutions who are considering making similar changes in assessment strategies.

A Guide to Competencies, Educational Goals, and Learning Objectives for Teaching Medical Histology in an Undergraduate Medical Education Setting.

Horizontal and vertical integration within medical school curricula, truncated contact hours available to teach basic biomedical sciences, and diverse assessment methods have left histology educators searching for an answer to a fundamental question-what ensures competency for medical students in histology upon completion of medical school? The Liaison Committee for Medical Education (LCME) and the Commission on Osteopathic College Accreditation (COCA) advocate faculty to provide medical students with a list of learning objectives prior to any educational activities, regardless of pedagogy. It is encouraged that the learning objectives are constructed using higher-order and measurable action verbs to ensure student-centered learning and assessment. A survey of the literature indicates that there is paucity of knowledge about competencies, goals, and learning objectives appropriate for histology education in preclinical years. To address this challenge, an interactive online taskforce, comprising faculty from across the United States, was assembled. The outcome of this project was a desired set of competencies for medical students in histology with educational goals and learning objectives to achieve them.

Virtual laboratory manual for microscopic anatomy.

Using digital technology, we have assembled a virtual laboratory manual (VLM) that is a Web-based copy of our traditional laboratory manual. The VLM is used to enhance traditional laboratory instruction in histology. For each reference in the VLM to either a histological slide or an electron micrograph (EM), hyperlinks are included that download digital images derived from the students' glass slide sets or scanned EMs. The VLM serves as an atlas of digital images for concurrent study of similar sections by light microscopy during laboratory sessions. In addition, students can review the images from the VLM at remote locations. We have encouraged continued use of light microscopes in laboratories by basing the majority of practical examination identifications on analysis of marked histological slides that require students to use their own microscopes. The VLM provides the convenience of a Web-based resource with high-quality images, yet allows retention of the many excellent traditional aspects of our course. An example of a VLM laboratory on epithelium is available online (http://users.von.uc.edu/michaeje/VLM-Epithelium/exLab4.pdf).

Survey of gross anatomy, microscopic anatomy, neuroscience, and embryology courses in medical school curricula in the United States.

Directors of courses in the basic anatomical sciences in allopathic and osteopathic medical schools in the United States were surveyed regarding the present composition of their courses. Results indicate the majority of gross anatomy courses are in the range of 126 to 200 total course hours, and that laboratory dissection is a key component of these courses. The majority of microscopic anatomy courses are in the range of 61 to 100 total course hours, generally divided equally between lecture and laboratory components. Additionally, despite the availability of computer technology, microscopes are still used in the vast majority of microscopic anatomy courses. The majority of neuroscience courses are in the range of 71 to 90 total course hours, with most of these hours devoted to lectures. Embryology is usually taught in conjunction with gross anatomy, although some schools present it with the microscopic anatomy course or as a separate course. Most embryology courses are in the range of 6 to 20 total course hours, with only a few having a laboratory component.

Interaction between two isoforms of the NF2 tumor suppressor protein, merlin, and between merlin and ezrin, suggests modulation of ERM proteins by merlin.

The product of the neurofibromatosis type II (NF2) tumor suppressor gene, merlin, is closely related to the ezrin-radixin-moesin (ERM) family, a group of proteins believed to link the cytoskeleton to the plasma membrane. Mutation in the NF2 locus is associated with Schwann cell tumors (schwannomas). The two predominant merlin isoforms, I and II, differ only in the carboxy-terminal 16 residues and only isoform I is anti-proliferative. Merlin lacks an actin-binding domain conserved among ezrin, radixin and moesin. Because merlin, ezrin and moesin are co-expressed in Schwann cells, and all homodimerize, we have examined whether merlin and ezrin dimerize with one another. We found by immunoprecipitation and yeast two-hybrid assays that both merlin isoforms interact with ezrin. The interaction occurs in a head-to-tail orientation, with the amino-terminal half of one protein interacting with the carboxy-terminal half of the other. The two merlin isoforms behave differently in their interaction with ezrin. Isoform I binds only ezrin whose carboxy-terminus is exposed, whereas isoform II binds ezrin regardless of whether ezrin is in the open or closed conformation. The heterodimerization of merlin is a much stronger interaction than the interaction between either merlin isoform and ezrin, and can inhibit merlin-ezrin binding. This suggests that, in vivo, merlin dimerization could regulate merlin-ERM protein interaction, and could thus indirectly regulate other interactions involving ERM proteins.

Properties of the nonhelical end domains of vimentin suggest a role in maintaining intermediate filament network structure.

To investigate the functional role of the nonhelical domains of the intermediate filament (IF) protein vimentin, we carried out transient transfection of constructs encoding fusion proteins of these domains with enhanced green fluorescent protein (EGFP). Expression of these fusion proteins did not have any effect on the endogenous IF networks of transfected cells. However, the head domain-EGFP fusion protein localized almost exclusively to the nucleus. This localization could be disrupted in a reversible fashion by chilling cells. Furthermore, the head domain was capable of targeting to the nucleus a strictly cytoplasmic protein, pyruvate kinase. Thus, the vimentin head domain contains information that specifically directs proteins into the nucleus. In contrast, the nonhelical tail domain of vimentin, when expressed as a fusion protein with EGFP, was retained in the cytoplasm. Cytoplasmic retention of tail domain-containing fusion proteins appeared to be dependent on the integrity of the microtubule network. Our results are consistent with a proposal that the nonhelical end domains of vimentin are involved in maintaining an extended IF network by exerting oppositely directed forces along the filaments. The head domains exert a nuclear-directed force while the tail domains extend the IF network toward the cell periphery via a microtubule-dependent mechanism.

The ubiquitin-ligase system in Trypanosoma brucei brucei.

The question of whether the African trypanosome Trypanosoma brucei brucei utilizes a ubiquitin-ligase system to conjugate the 8,500-dalton protein ubiquitin to other proteins has not been investigated. Using 125I-labeled ubiquitin and gel electrophoresis (sodium dodecyl sulfate and acetic acid, urea, Triton X-100), we looked for the incorporation of label into proteins larger than ubiquitin to determine ubiquitin-ligase system activity in cytosolic and nuclear lysates of long slender, intermediate, and short stumpy bloodstream-form trypanosomes. We present data suggesting that there is cytosolic activity of a ubiquitin-ligase system in all three bloodstream forms of T. brucei brucei. There are indications that the three bloodstream forms of T. brucei brucei differ in their cytosolic ubiquitin-ligase system activity. Our assay showed no activity of this system in the nucleus of T. brucei brucei. Further studies on the ubiquitin-ligase system in T. brucei brucei may define differences between the three bloodstream forms, the parasite, and its host, leading to development of novel chemotherapeutic strategies.