Baltazar Espiritu

IL-4 induces differentiation and expansion of Th2 cytokine-producing eosinophils.

Innate effector cells that produce Th2-type cytokines are critical in Th2 cell-mediated immune responses. However, it is not known how these cells acquire the ability to produce Th2 cytokines. IL-4 is a potent inducer that directs differentiation of naive CD4+ T cells into CD4+ Th2 effector cells. To determine whether IL-4 can induce differentiation and expansion of Th2 cytokine-producing innate cells, we used mice whose il-4 gene was replaced by a knock-in green fluorescence protein (gfp) gene. We found that, directly ex vivo, IL-4 increased the number of GFP+ cells in the airway and the lung tissue in an Ag-specific manner. The majority of GFP+ cells were eosinophils, suggesting that IL-4 plays a pivotal role in expanding IL-4-producing eosinophils in vivo. IL-4-producing eosinophils showed some unique features compared with IL-4-producing CD4+ T cells. They exhibited biallelic expression of the il-4 gene when stimulated and were more dominant IL-4- and IL-5-producing cells. Furthermore, we show that IL-4 drove bone marrow progenitor cells to differentiate into Th2 cytokine-producing eosinophils in vitro. These results strongly suggest IL-4 is a potent factor in directing bone marrow progenitor cells to differentiate into Th2 cytokine-producing eosinophils.

An analysis of lecture video utilization in undergraduate medical education: associations with performance in the courses.

BackgroundIncreasing numbers of medical schools are providing videos of lectures to their students. This study sought to analyze utilization of lecture videos by medical students in their basic science courses and to determine if student utilization was associated with performance on exams.MethodsStreaming videos of lectures (n = 149) to first year and second year medical students (n = 284) were made available through a password-protected server. Server logs were analyzed over a 10-week period for both classes. For each lecture, the logs recorded time and location from which students accessed the file. A survey was administered at the end of the courses to obtain additional information about student use of the videos.ResultsThere was a wide disparity in the level of use of lecture videos by medical students with the majority of students accessing the lecture videos sparingly (60% of the students viewed less than 10% of the available videos. The anonymous student survey revealed that students tended to view the videos by themselves from home during weekends and prior to exams. Students who accessed lecture videos more frequently had significantly (p < 0.002) lower exam scores.ConclusionWe conclude that videos of lectures are used by relatively few medical students and that individual use of videos is associated with the degree to which students are having difficulty with the subject matter.

An audience response system may influence student performance on anatomy examination questions.

This study integrated an in‐house audience response system (ARS) in the human anatomy course over two years to determine whether students performed better on high‐stakes examinations following exposure to similar interactive questions in a large lecture format. Questions in an interactive ARS format were presented in lectures via PowerPoint presentations. Students who chose to participate in the anonymous ARS sessions submitted answers via their personal wireless devices (e.g., laptops, smartphones, PDAs, etc). Students were surveyed for feedback. Student participation in ARS activities was greatest (65–80%) in the first lecture. The number of students who actively participated in ARS activities decreased over the next four sessions, and then slightly increased in the last two sessions. This trend was the same for both years. Use of the ARS did not dramatically enhance overall student performance on examination questions that dealt with content similar to content presented in the ARS sessions. However, students who scored in the lower quartile of the examination performed better on the examination questions after the ARS was implemented. Accordingly, our findings suggest that the effect of ARS to improve student performance on examinations was not uniform. The overall benefit of an ARS to enhance the lecture experience was confirmed by student surveys. Anat Sci Educ.

A Three-year Study of Lecture Multimedia Utilization in the Medical Curriculum: Associations with Performances in the Basic Sciences

This study assesses the frequency with which medical students access video and audio files of lectures in the basic sciences and attempts to determine if the use of such multimedia is associated with examination performance. Data from nine separate courses were analyzed over a three-year period. Students were required to log into the server, which recorded the date and time that specific multimedia files were accessed. The server logs were entered into an Excel spreadsheet, sorted according to student identification numbers and the frequencies of downloads and viewings tabulated by course and lecture. The scores received in each course by individual students were entered before deleting the identification number to preserve anonymity. The data were analyzed using Pearson’s correlation for the sample and one-way analysis of variance. Students viewed lecture videos more frequently than they downloaded the audio files, with the overall ratio of video viewings to audio downloads being 2.5:1. The majority of students (64–78%) accessed relatively few video and audio files of lectures (<10%), trends that were consistently seen in all courses. There were significant correlations for the frequency with which individual students viewed videos of lectures regardless of the course. The patterns for distribution of lecture videos viewed were similar from year-to-year and were unaffected by the elimination of course handouts. Finally, there was an inverse trend between the frequency with which students viewed videos of lectures and their performance in the courses as reflected in their final grades. We found that a small percentage (<10%) of all students regularly use lecture multimedia (audio and video), and results suggest that those students who perform less well on assessments use these multimedia resources to a greater extent.

Associations between formative practice quizzes and summative examination outcomes in a medical anatomy course

Formative practice quizzes have become common resources for self‐evaluation and focused reviews of course content in the medical curriculum. We conducted two separate studies to (1) compare the effects of a single or multiple voluntary practice quizzes on subsequent summative examinations and (2) examine when students are most likely to use practice quizzes relative to the summative examinations. In the first study, providing a single on‐line practice quiz followed by instructor feedback had no effect on examination average grades compared to the previous year or student performances on similar questions. However, there were significant correlations between student performance on each practice quiz and each summative examination (r = 0.42 and r = 0.24). When students were provided multiple practice quizzes with feedback (second study), there were weak correlations between the frequency of use and performance on each summative examination (r = 0.17 and r = 0.07). The frequency with which students accessed the practice quizzes was greatest the day before each examination. In both studies, there was a decline in the level of student utilization of practice quizzes over time. We conclude that practice quizzes provide some predictive value for performances on summative examinations. Second, making practice quizzes available for longer periods prior to summative examinations does not promote the use of the quizzes as a study strategy because students appear to use them mostly to assess knowledge one to two days prior to examinations. Anat Sci Educ 8: 37–44.

The effectiveness of annotated (vs. non‐annotated) digital pathology slides as a teaching tool during dermatology and pathology residencies

With todays technology, paraffin‐embedded, hematoxylin & eosin‐stained pathology slides can be scanned to generate high quality virtual slides. Using proprietary software, digital images can also be annotated with arrows, circles and boxes to highlight certain diagnostic features. Previous studies assessing digital microscopy as a teaching tool did not involve the annotation of digital images. The objective of this study was to compare the effectiveness of annotated digital pathology slides versus non‐annotated digital pathology slides as a teaching tool during dermatology and pathology residencies.

Computer-Based Testing in the Medical Curriculum: A Decade of Experiences at One School

This report summarizes more than a decade of experiences with implementing computer-based testing across a 4-year medical curriculum. Practical considerations are given to the fields incorporated within an item database and their use in the creation and analysis of examinations, security issues in the delivery and integrity of examinations, curricular integration, use of examination log files, effectiveness and timeliness of reports, and the potential for educational research. The solutions to many complicated issues have practical relevance and interest to the community of educators who are considering the adoption of this technology for assessment.