A Student-Led Methodology for Evaluating Curricular Redundancy

Background: Curricular redundancy can be a significant problem for any educational curriculum. Redundancy can be both desirable and undesirable, but differentiating the two can be quite challenging. Further, pinpointing undesirable redundancy and quantifying it so as to produce an estimate of inefficiency is even more difficult. Purpose: The purpose of this research is to describe a student-led strategy for evaluating redundancy in a highly integrated medical school curriculum. It is our hope that the methodology presented here will serve as a useful evaluation model for persons attempting similar work in various educational arenas. Setting: A highly-integrated medical school at a large public university. Intervention: This research did not require an intervention. Research Design: We identified two advanced medical students and asked them to identify redundant material across the first two years of the medical school curriculum. The students had to operationalize ‘redundancy’, develop an evaluation plan/framework, and evaluate the extent to which undesirable redundancy was prevalent in the current curriculum. Data Collection and Analysis: Students reviewed course syllabi, notes, and materials and documented the amount of redundant material they found in the curriculum. Findings: A total of approximately 167 hours, or 8.35 weeks, could be eliminated from the curriculum; the vast majority of the redundancy occurred as a result of small group activities

Mie light scattering calculations for an Indian age-related nuclear cataract with a high density of multilamellar bodies

Purpose: Multilamellar bodies (MLBs) are lipid-coated spheres (1–4 µm in diameter) found with greater frequency in the nuclear region of human age-related cataracts compared with human transparent lenses. Mie light scattering calculations have demonstrated that MLBs are potential sources of forward light scattering in human age-related nuclear cataracts due to their shape, size, frequency, and cytoplasmic contents, which often differ in refractive index from their surroundings. Previous studies have used data from several non-serial tissue sections viewed by light microscopy to extrapolate a volume and have assumed that MLBs are random in distribution. Currently, confocal microscopy is being used to examine actual tissue volumes from age-related nuclear cataracts and transparent lenses collected in India to confirm MLB shape, size, frequency, and randomness. These data allow Mie scattering calculations to be done with directly observed MLBs in intact tissue. Methods: Whole Indian donor lenses and Indian lens nuclei after extracapsular cataract extraction were immersion-fixed in 10% formalin for 24 h and in 4% paraformaldehyde for 24 h before sectioning with a Vibratome. The 160 µm thick sections were stained for 24 h in the lipid dye DiI (1,1’-dilinoleyl-3,3,3′,3′ tetramethylindocarbocyanine, 4-chlorobenzenesulfonate), washed, stabilized in Permount under coverslips and examined with a Zeiss LSM 510 confocal microscope. Individual volumes of tissue (each typically 500,000 µm3) were examined using a plan-apochromat 63X oil (NA=1.4) lens. Other lenses were prepared for electron microscopy and histological examination using previously described procedures. Results: Analysis of tissue volumes within Indian age-related nuclear cataracts and transparent lenses has confirmed that most MLBs are 1–4 µm in diameter and typically spherical with some occurring as doublets or in clusters. Most Indian cataracts and transparent lenses are similar to samples obtained in the United States. One cataract contained as many as 400,000 MLBs per mm3 –100 times more than in cataracts collected in the United States. Pairwise distribution analysis has revealed that MLBs even in this exceptional case are found with a distribution that appears to be random. Mie calculations indicate that more than 90% of the incident light could be scattered by the high density of MLBs. Conclusions: An important finding was that one advanced Indian cataract contained many more MLBs than cataracts examined from India and previously from the United States. This indicates that specific conditions or susceptibilities may exist that promote the formation of excessive MLBs. Based on the extremely high frequency, as well as their spherical shape, large size, and apparent random distribution, the MLBs are predicted according to Mie light scattering calculations to cause high amounts of forward scattering sufficient to produce nuclear opacity

Simple fixation and storage protocol for preserving the internal structure of intact human donor lenses and extracted human nuclear cataract specimens

Purpose: Increased use of phacoemulsification procedures for cataract surgeries has resulted in a dramatic decrease in the availability of cataractous nuclear specimens for basic research into the mechanism of human cataract formation. To overcome such difficulties, a fixation protocol was developed to provide good initial fixation of human donor lenses and extracted nuclei, when available, and is suitable for storing or shipping cataracts to laboratories where structural studies could be completed. Methods: Cataractous lens nuclei (n=19, ages 12 to 74 years) were obtained from operating suites after extracapsular extraction. Transparent human donor lenses (n=27, ages 22 to 92 years) were obtained from the Ramayamma International Eye Bank. After the dimensions were measured with a digital caliper, samples were preserved in 10% formalin (neutral buffered) for 24 h and followed by fixation in 4% paraformaldehyde (pH 7.2) for 48 h. Samples were stored cold (4 °C) in buffer until shipped. Samples were photographed and measured before further processing for transmission electron microscopy. Results: The dimensions of the samples varied slightly after short fixation followed by 1 to 5 months’ storage before transmission electron microscopy processing. The mean change in the axial thickness of the donor lenses was 0.15±0.21 mm or 3.0±5.4%, while that of the extracted nuclei was 0.05±0.24 mm or 1.8±7.6%. Because the initial concern was whether the nuclear core was preserved, thin sections were examined from the embryonic and fetal nuclear regions. All cellular structures were preserved, including the cytoplasm, complex edge processes, membranes, and junctions. The preservation quality was excellent and nearly equivalent to preservation of fresh lenses even for the lens cortex. Cell damage characteristic of specific nuclear cataract types was easily recognized. Conclusions: The novel fixation protocol appears effective in preserving whole donor lenses and cataractous nuclei over a wide age range. Dimensions varied only 2%–3%, and fiber cell damage correlated well with standard fixation. These methods enable researchers and clinicians in remote settings to preserve donor lenses and rare examples of extracapsular extractions for detailed examination at later times

Cracking the Nut on LCME Standard 8.7: Innovations to Ensure Comparability Across Geographically Distributed Campuses

Problem: A large state university in the southeastern United States and state Area Health Education Centers (AHEC) collaborated to establish branch campuses to increase clinical capacity for medical student education. Prior to formally becoming branch campuses, two AHEC sites had established innovative curricular structures different than the central campus. These sites worked with the central campus as clinical training sites. Upon becoming formal campuses, their unique clinical experiences were maintained. A third campus established a curricular structure identical to the central campus. Little exists in the literature regarding strategies that ensure comparability yet allow campuses to remain unique and innovative. Intervention: We implemented a balanced matrix organizational structure, well-defined communication plan, and newly developed tool to track comparability. A balanced matrix organization model framed the campus relationships. Adopting this model led to identifying reporting structures, developing multidirectional communication strategies, and the Campus Comparability Tool. Context: The UNC School of Medicine central campus is in Chapel Hill. All 192 students complete basic science course work on central campus. For required clinical rotations, approximately 140 students are assigned to the central campus, which includes rotations in Raleigh or Greensboro. The remaining students are assigned to Asheville (25–30), Charlotte (25–30), or Wilmington (5–7). Chapel Hill and Wilmington follow identical rotation structures, 16 weeks each of (a) combined surgery and adult inpatient experiences; (b) combined obstetrics/gynecology, psychiatry, and inpatient pediatrics; and (c) longitudinal clinical experiences in adult and pediatric medicine. Asheville offers an 8-month longitudinal integrated outpatient experience with discreet inpatient experiences in surgery and adult care. Charlotte offers a 6-month longitudinal integrated experiences and 6 months of block inpatient experiences. Aside from Charlotte and Raleigh, the other sites are urban but surrounded by rural counties. Chapel Hill is 221 miles from Asheville, 141 from Charlotte, and 156 from Wilmington. Outcome: Using the balanced matrix organization, various reporting structures and lines of communication ensured the educational objectives for students were clear on all campuses. The communication strategies facilitated developing consistent evaluation metrics across sites to compare educational experiences. Lessons Learned: The complexities of different healthcare systems becoming regional campuses require deliberate planning and understanding the culture of those sites. Recognizing how size and location of the organization affects communication, the central campus took the lead centralizing functions when appropriate. Adopting uniform educational technology has played an essential role in evaluating the comparability of core educational content on campuses delivering content in very distinct ways

Ultrastructural analysis of the human lens fiber cell remodeling zone and the initiation of cellular compaction

The purpose is to determine the nature of the cellular rearrangements occurring through the remodeling zone (RZ) in human donor lenses, identified previously by confocal microscopy to be about 100 µm from the capsule. Human donor lenses were fixed with 10% formalin followed by 4% paraformaldehyde prior to processing for transmission electron microscopy. Of 27 fixed lenses, ages 22, 55 and 92 years were examined in detail. Overview electron micrographs confirmed the loss of cellular organization present in the outer cortex (80 µm thick) as the cells transitioned into the RZ. The transition occurred within a few cell layers and fiber cells in the RZ completely lost their classical hexagonal cross-sectional appearance. Cell interfaces became unusually interdigitated and irregular even though the radial cell columns were retained. Gap junctions appeared to be unaffected. After the RZ (40 µm thick), the cells were still irregular but more recognizable as fiber cells with typical interdigitations and the appearance of undulating membranes. Cell thickness was irregular after the RZ with some cells compacted, while others were not, up to the zone of full compaction in the adult nucleus. Similar dramatic cellular changes were observed within the RZ for each lens regardless of age. Because the cytoskeleton controls cell shape, dramatic cellular rearrangements that occur in the RZ most likely are due to alterations in the associations of crystallins to the lens-specific cytoskeletal beaded intermediate filaments. It is also likely that cytoskeletal attachments to membranes are altered to allow undulating membranes to develop

Multilamellar spherical particles as potential sources of excessive light scattering in human age-related nuclear cataracts

The goal of this project was to determine the relative refractive index (RI) of the interior of multilamellar bodies (MLBs) compared to the adjacent cytoplasm within human nuclear fiber cells. MLBs have been characterized previously as 1-4 μm diameter spherical particles covered by multiple lipid bilayers surrounding a cytoplasmic core of variable density. Age-related nuclear cataracts have more MLBs than transparent donor lenses and were predicted to have high forward scattering according to Mie scattering theory, assuming different RIs for the MLB and cytoplasm. In this study quantitative values of relative RI were determined from specific MLBs in electron micrographs of thin sections and used to calculate new Mie scattering plots. Fresh lenses were Vibratome sectioned, immersion fixed and en bloc stained with osmium tetroxide and uranyl acetate, or uranyl acetate alone, prior to dehydration and embedding in epoxy or acrylic resins. Thin sections 70 nm thick were cut on a diamond knife and imaged without grid stains at 60 kV using a CCD camera on a transmission electron microscope (TEM). Integrated intensities in digital electron micrographs were related directly to protein density, which is linearly related to RI for a given substance. The RI of the MLB interior was calculated assuming an RI value of 1.42 for the cytoplasm from the literature. Calculated RI values for MLBs ranged from 1.35 to 1.53. Thus, some MLBs appeared to have interior protein densities similar to or less than the adjacent cytoplasm whereas others had significantly higher densities. The higher density MLBs occurred preferentially in older and more advanced cataracts suggesting a maturation process. The bilayer coats were more often observed in MLBs from transparent donors and early stage cataracts indicating that bilayer loss was part of the MLB maturation, producing large low-density spaces around dense MLB cores. These spaces were frequently observed in advanced cataracts from India as large low-density crescents and annular rings. Predicted scattering from Mie plots using particles with dense cores and low-density rims was higher than reported previously, although the most important factor was the relative RI , not the MLB coat or lack thereof. In conclusion, the measurements confirm the high protein density and RI of some MLB interiors compared to adjacent cytoplasm. This high RI ratio used in the Mie calculations suggests that for 2 000 MLBs/mm3, about half that reported for early stage nuclear cataracts from the US, the forward scattering could be more than 30% of the incident light. Therefore, the extent of forward scattering and its influence on macular visual acuity could be important components of ophthalmological evaluations of cataract patients

Medical Student Leadership Development through a Business School Partnership Model: A Case Study and Implementation Strategy

Background: There is an ongoing call for leadership development in academic health care and medical students desire more training in this area. Although many schools offer combined MD/MBA programs or leadership training in targeted areas, these programs do not often align with medical school leadership competencies and are limited in reaching a large number of students.Methods:The Leadership Initiative (LI) was a program created by a partnership between a School of Medicine (SOM) and Business School with a learning model that emphasized the progression from principles to practice, and the competencies of self-awareness, communication, and collaboration/teamwork. Through offerings across a medical school curriculum, the LI introduced leadership principles and provided an opportunity to apply them in an interactive activity or simulation. We utilized the existing SOM evaluation platform to collect data on program outcomes that included satisfaction, fidelity to the learning model, and impact.Results:From 2017 to 2020, over 70% of first-year medical students participated in LI course offerings while a smaller percentage of fourth-year students engaged in the curriculum. Most students had no prior awareness of LI course material and were equivocal about their ability to apply lessons learned to their medical school experience. Students reported that the LI offerings provided opportunities to practice the skills and competencies of self-awareness, communication, and collaboration/teamwork.Discussion: Adding new activities to an already crowded medical curriculum was the greatest logistical challenge. The LI was successful in introducing leadership principles but faced obstacles in having participants apply and practice these principles. Most students reported that the LI offerings were aligned with the foundational competencies

Ultrastructural analysis of damage to nuclear fiber cell membranes in advanced age-related cataracts from India

The primary goal was to characterize the structural alterations that occur at the fiber cell interfaces in nuclei of fully opaque cataracts removed by extracapsular cataract surgery in India. The dark yellow to brunescent nuclei, ages 38–78 years, were probably representative of advanced age-related nuclear cataracts. Thick tissue slices were fixed, en bloc stained and embedded for transmission electron microscopy. Stained thin sections contained well-preserved membranes and junctions, although the complex cellular topology often made it necessary to tilt the grid extensively to visualize the membranes. Damage to the fiber cell membranes was noted in all regions of the nucleus. The most important damage occurred within undulating membrane junctions where the loss of membrane segments was common. These membrane breaks were not sites of fusion as membrane edges were detected and cytoplasm appeared to be in contact with extracellular space, which was enlarged in many regions. Dense deposits of protein-like material were frequently observed within the extracellular space and appeared to be similar to protein in the adjacent cytoplasm. The deposits were often 20–50 nm thick, variable in length and located on specific sites on plasma membranes and between clusters of cells or cell processes. In addition, low density regions were seen within the extracellular space, especially within highly undulating membranes where spaces about 100 nm in diameter were observed. The membrane damage was more extensive and extracellular spaces were larger than in aged transparent donor lenses. Because high and low density regions contribute equally to the fluctuations in refractive index, the changes in density due to the observed damage near membranes are likely to produce significant light scattering based on theoretical analysis. The dimensions of the fluctuations in the range 20–100 nm imply that the scattering is probably similar to that of small particles that would increase high-angle scattering visible in the slit lamp. Such damage to membranes would be expected to contribute to the total opacification of the nucleus as the cataract matures. The main sources of the fluctuations appear to be the degradation of membranes and adjacent cytoplasmic proteins, as well as the redistribution of proteins and fragments

Autophagy and mitophagy participate in ocular lens organelle degradation

The eye lens consists of a layer of epithelial cells that overlay a series of differentiating fiber cells that upon maturation lose their mitochondria, nuclei and other organelles. Lens transparency relies on the metabolic function of mitochondria contained in the lens epithelial cells and in the immature fiber cells and the programmed degradation of mitochondria and other organelles occurring upon lens fiber cell maturation. Loss of lens mitochondrial function in the epithelium or failure to degrade mitochondria and other organelles in lens fiber cells results in lens cataract formation. To date, the mechanisms that govern the maintenance of mitochondria in the lens and the degradation of mitochondria during programmed lens fiber cell maturation have not been fully elucidated. Here, we demonstrate using electron microscopy and dual-label confocal imaging the presence of autophagic vesicles containing mitochondria in lens epithelial cells, immature lens fiber cells and during early stages of lens fiber cell differentiation. We also show that mitophagy is induced in primary lens epithelial cells upon serum starvation. These data provide evidence that autophagy occurs throughout the lens and that mitophagy functions in the lens to remove damaged mitochondria from the lens epithelium and to degrade mitochondria in the differentiating lens fiber cells for lens development. The results provide a novel mechanism for how mitochondria are maintained to preserve lens metabolic function and how mitochondria are degraded upon lens fiber cell maturation