Medical Histopathology Laboratories: Remote Teaching in Response to COVID-19 Pandemic.

The COVID-19 pandemic required the rapid conversion of medical school curricula to virtual instruction. Prior to the crisis, histopathology teaching laboratories at UT Health San Antonio included completion of an Individual Laboratory Quiz before the laboratory session, a Team Application Exercise released and completed during the laboratory session with guidance from faculty, and a graded Team Laboratory Quiz at the end of the laboratory session. Adaptation of this interactive, in-person activity to a fully online platform included releasing the Team Application Exercise earlier to provide ample time for students to work virtually with their teams, conducting laboratory sessions using Microsoft Teams, with 5 to 6 teams led by a single instructor, and requiring the Team Laboratory Quiz to be taken individually for ensuring quiz security and test integrity. For incentivizing collaboration while completing the Team Application Exercise, the final score was either the student's individual score on the Team Laboratory Quiz or their team's average, whichever was higher. Comparison of student scores on the modified Team Laboratory Quiz to Team Laboratory Quiz scores using the earlier laboratory format prior to COVID-19 showed a significant decline; however, scores on other weekly quizzes or examinations were unaffected. Students welcomed the early release of Team Application Exercise and easier access to faculty but indicated that the modified Team Laboratory Quiz decreased peer-teaching and learning experience and increased anxiety. Faculty indicated the loss of personal interaction with students as a major theme. These data suggest that novel pedagogical approaches are required for online histopathology instruction to accommodate differences in learning styles while maintaining the benefits of team collaboration.

A Three-Dimensional Print Model of the Pterygopalatine Fossa Significantly Enhances the Learning Experience.

The pterygopalatine fossa (PPF) is a bilateral space deep within the skull that serves as a major neurovascular junction. However, its small volume and poor accessibility make it a difficult space to comprehend using two-dimensional illustrations and cadaveric dissections. A three-dimensional (3D) printed model of the PPF was developed as a visual and kinesthetic learning tool for completely visualizing the fossa, its boundaries, its communicating channels, and its neurovascular structures. The model was evaluated by analyzing student performance on pre- and post-quizzes and a student satisfaction survey based on the five-point Likert scale. The first cohort comprised of 88 students who had never before studied the PPF. The second cohort consisted of 30 students who were previously taught the PPF. Each cohort was randomly divided into a control group who were provided with a half skull and an intervention group that were provided with the 3D printed model. The intervention group performed significantly better on the post-quiz as compared to the control group in cohort I (P = 0.001); while not significant, it also improved learning in cohort II students (P = 0.124). Satisfaction surveys indicated that the intervention group found the 3D printed model to be significantly more useful (P < 0.05) as compared to the half skull used by the control group. Importantly, the effect sizes for cohorts I and II (0.504 and 0.581, respectively) validated the statistical results. Together, this study highlights the importance of 3D printed models as teaching tools in anatomy education.

Clinical Case-Based Image Portfolios in Medical Histopathology.

This descriptive article describes the use of clinical case-based portfolios in histopathology teaching laboratories in conjunction with virtual microscopy not only to integrate histology and pathology disciplines for first and second year medical students but also to stimulate student engagement, promote self-directed and group-based learning and enhance student-to-student interaction in a structured manner. Portfolios consisted of PowerPoint files encompassing four to five clinical case studies relevant to the topics covered that week. Portfolios integrated study materials provided in the module-specific lectures, clinical skill lectures, and online interactive content. Two sets of portfolios, Individual and Group, were used. Individual Portfolios were completed by each student and uploaded prior to the laboratory session. Group Portfolios were completed by students working together in small groups during the laboratory session with minimal faculty assistance. The functional utility and acceptance of Individual and Group Portfolios among first- and second-year medical students was evaluated using electronic surveys and examination performances. Both first- and second-year students agreed that the use of portfolios in conjunction with virtual microscopy promoted understanding and encouraged discussion of the topics covered during the week and that group members worked well together and contributed to the completion of the portfolios. Performances on the Histology and Cell Biology and Pathology sections on the United States Medical Licensing Examination® (USMLE® ) remained consistent and in line with national averages. Overall, use of portfolios promoted peer teaching and contributed towards successful transition to the new system-based integrated curriculum with continued strong performance on the USMLE.

Dehydration increases sodium-dependent glutamate uptake by hypothalamic paraventricular nucleus synaptosomes.

OBJECTIVES: The purpose of this study was to identify and characterize Na+-dependent, high affinity glutamate transporter (GLUT) activity in the hypothalamic paraventricular nucleus (PVN) and to compare GLUT activity in PVN of euhydrated versus water-deprived rats. METHODS: Sprague-Dawley rats were deprived of water for two days before sacrifice. Control rats received water ad libitum. After sacrifice, PVN and cerebrum were removed and synaptosomes were prepared using standard techniques. Glutamate uptake was measured using [3H]-glutamate as substrate, physiological buffer, approximately 100 µg of synaptosomal tissue per assay and a Brandel cell harvester. RESULTS: Glutamate uptake was saturable in PVN synaptosomes from euhydrated, control rats with a Vmax of 541 ± 22 pmol/min-mg protein (SEM) and Km of 17.6 ± 3.8 µM (SEM). In contrast, Vmax of glutamate uptake was 808 ± 58 pmol/min-mg protein in PVN of rats deprived of water for 2 days. This was significantly higher than controls (p<0.001). Km was 21.2 ± 7.3 µM and not significantly different from controls (NS). CONCLUSIONS: Our results suggest that water deprivation of rats results in significantly higher synaptosomal glutamate uptake in PVN. Although the exact mechanism is unknown, increased transcription of the GLUT gene and/or increased cell surface expression of GLUT may contribute to the observed increase of glutamate uptake in dehydrated rats. Increased glutamate uptake may serve to restrict dehydration-induced activation of PVN efferent pathways specifically involved in release of neurohypophysial hormones and activation of sympathetic outflow that operate to maintain body fluid balance and cardiovascular function.

Dependence of 3',5'-cyclic adenosine monophosphate--stimulated gonadotropin-releasing hormone release on intracellular calcium levels and L-type calcium channels in superfused GT1-7 neurons.

OBJECTIVE: Immortalized GT1-7 neurons were used to characterize the interactive roles of adenylate cyclase-3',5'-cyclic adenosine monophosphate (cAMP) and L-type calcium channels on gonadotropin-releasing hormone (GnRH) release. METHODS: Dibutyryl (db)-cAMP was used as an active analog of endogenous cAMP, and forskolin was used to activate adenylate cyclase. Extracellular calcium was chelated using EGTA and L-type calcium channels were blocked using nimodipine. The selective Ca2+ ionophore A23187 was employed to increase intracellular calcium levels. GT1-7 neurons were grown on Cytodex-3 beads (Pharmacia Biotech, Uppsala, Sweden) and placed in special superfusion microchambers. The cells were superfused at a rate of 6.2 mL/h with media 199 (M-199; Gibco, Grand Island, NY; pH 7.35, 37C); effluent fractions were collected at 5-minute intervals for analysis of GnRH concentrations by radioimmunoassay. RESULTS: Basal GnRH release from superfused GT1-7 neurons ranged from 10 to 62 pg. min(-1). mL(-1). Coexposure of the cells to forskolin and A23187 produced an additive effect on stimulated release of GnRH. Cells exposed to 1 microM of forskolin (an activator of adenylate cyclase) for 5 minutes showed a 2.6-fold increase in GnRH release. Likewise, the addition of 100 microM of db-cAMP to the superfusion for 5 minutes demonstrated a 2.3-fold increase in the amplitude of GnRH secretion. Maintaining the superfused cells in medium containing 5 mM EGTA had no obvious effect on basal GnRH release but blocked the effect of db-cAMP to increase GnRH release. Similarly, the addition of 10 microM nimodipine to the superfusion medium blocked db-cAMP-stimulated GnRH release. CONCLUSIONS: These findings provide additional evidence that cAMP-mediated GnRH release from GT1-7 neurons is dependent on influx of extracellular calcium via L-type Ca2+ channels.