bluuebunny/crossref_metadata_2025 huggingface dataset:
Cognitive Function as Related to Cumulative Head Impact Exposure in Football: Effects of Position
Authors: Deluce Danielle Brewer , Wilson Timothy D , Owen Adrian M
Published: November 2023

Repetitive sub‐clinical head impacts are linked to progressive cognitive decline and chronic traumatic encephalopathy (CTE) diagnoses in professional contact‐sport athletes post mortem. There exists a gap however in understanding when this long‐term damage occurs, and specifically in determining the career stage when signs of injury can be first detected or even the influence of a single season of play. In 2014, our group used a 12‐test online cognitive battery (www.cambridgebrainsciences.com) to study the cognitive function of a population of 35 male varsity football athletes in both the pre‐ and post‐season. In comparison to controls, the athletes showed decreased scores in the pre‐season with no pre‐ to post‐season differences. Additionally, athletes’ concussion histories were not correlated with any cognitive measure.

Given the positional variation in head impact exposure profiles and CTE diagnoses in football, the objective of the current study is to determine the influence of player position, and thus head impact exposure profile, on cognitive function over the course of a single season as well as the athletes’ careers up until this point. Participants consisted of an overlapping sample of athletes from the same football team for the 2014 and 2015 athletic seasons. Cognitive function was determined using cognitive battery scores and reaction times of players in both the pre‐ and post‐ season. Preliminary results, both aggregated and stratified by position demonstrate there was no difference between pre‐ and post‐season battery scores or reaction times. In accordance with our previous results, this suggests that a single season of head impact exposure does not cause significant cognitive decline. However, when considering all data as a representation of career‐long exposure, results suggest that wide receivers have the fastest reaction times on cognitive tests and consistently outperform their defensive linemen counterparts in terms of battery score. Defensive linemen also demonstrate the most variable reaction times. Previous studies analysing impact magnitude and frequency suggest that defensive linemen sustain significantly more low force hits while the wide receivers endure fewer hits but of high collision forces. Additionally, studies assessing the frequency of CTE diagnosis by position suggest fewer diagnoses in former wide receivers than in defensive linemen. Collectively, these results align well with previously published biomechanical and clinical literature and suggest that there is a continuum of cognitive function impairments across positions and head impact exposure profiles. Better characterization of the relationship between sport‐and position‐specific head impact exposure profiles and cognitive function may help guide participation, coaching strategies, and safe play decisions in sport.

Support or Funding Information

Research supported by CERC funding awarded to AMO
Morphometric analysis of the blood‐brain barrier in the peri‐infarct zone in young adult and aged mice
Authors: Nahirney Patrick C , Reeson Patrick , Brown Craig E
Published: November 2023

After an ischemic stroke, the blood brain barrier (BBB) is compromised in the peri‐infarct zone leading to secondary injury and neuronal dysfunction that can limit brain recovery. There is uncertainty what accounts for an increase in BBB permeability in capillaries of peri‐infarct tissues, particularly in aged animals. We utilized electron microscopy to study early (3 h) and late (72 h) changes to the BBB in young (3–4 mo) adult and aged (18 mo) mice after photothrombotic stroke. In all groups, peri‐infarct BBB permeability (as determined by Evans blue extravasation) was accompanied by endothelial swelling and an increase in transcytotic vesicles and vacuoles. In flowing capillaries, tight junctions (TJ) between endothelial cells were intact although small gaps were detected in a fraction of cases. In young adult mice (but not old mice) there was a marked increase in pericyte size and coverage of the capillaries. In both groups, thickening of the underlying basement membrane of capillaries peaked at 3 h and partially recovered by 72 h in young but not aged mice. Surrounding astrocytes and their mitochondria were severely swollen at both times points and ages. At 72 h, astrocytes were filled with glycogen deposits suggesting an upregulation of energy storage. These data suggest that BBB permeability in the peri‐infarct cortex of young adult and aged animals is likely mediated by transcellular pathways rather than TJ disruption. Additionally, our results indicate that pericyte and basement membrane responses to ischemia are affected by aging.

Support or Funding Information

Heart and Stroke Foundation of BC and Yukon, CIHR, MSFHR, CFI, NSERC
An immunohistochemistry protocol to identify satellite glial cells positive for GFAP in the dorsal root ganglion of rats in different ages
Authors: Simões Ana Leda B , Giorgetto Carolina , Carmo Elisabete C , Machado Nathalia B , Sanada Luciana S , Fazan Valeria Paula Sassoli
Published: November 2023

The nervous system is characterized by its high capacity of differentiation and cellular plasticity, especially during the neonatal period [1]. It is well known that the satellite glial cells (SGCs) in the dorsal root ganglion of adult animals are easily identified by their expression of glial fibrillary acidic protein (GFAP), and surround the neuron cell body forming a typical “ring shape” in histological images. However, we didn't find any description in the literature regarding the development and maturation of satellite glial cells in the dorsal root ganglion (DRG) The aim of this work is to validate an immunohistochemical method (IHQ), which identifies SGCs in DRG of rats during different stages of development. Thus, Wistar rats (n=4), male and female, were investigated 15, 30, 90 and 180 days after birth. The animals were anesthetized, perfused with 4% buffered paraformaldehyde and had the left L5 DRG removed and frozen. Criossections (8 μm) were incubated in rabbit polyclonal antibody anti‐glial fibrillary acidic protein (GFAP) (1:2.000, 24 hr) followed by biotinylated anti‐rabbit IgG (1:500; 24h) and finally Extravidin‐HRP (1:1.500; 24h) [2]. Our results showed that there was immunoreactivity for small round cells in the DRG of animals with 15 and 30 days‐old, whereas there was immunostaining in SGCs of animals with 90 and 180 days‐old, according to the patterns described in the literature. This indicates that his method is viable, reproducible and effective for the identification of SGCs in the DRG of adult animals. We also demonstrated that the hitological organization of the SGCs in the DRG as described in the literature appears only after 90 days of life. Future studies will be performed to investigate this development and maturation of the SGCs in the DRG.

Support or Funding Information

FAPESP, CNPq, CAPES and FAEPA
Role of Peer‐Teaching in Graduate Anatomical Sciences Education
Authors: Lee Lisa MJ
Published: November 2023

Educational effectiveness of peer‐teaching in K12 through undergraduate education has been well documented. Peer‐teaching activities have been shown to increase active learning engagement and long‐term retention of learned material. It is not surprising that more and more professional health sciences programs are implementing problem‐based learning and team‐based learning in their curricula of which peer‐teaching is an essential component. While the integration of peer‐teaching activities are widely utilized in medical education, reports on the use and effectiveness of peer‐teaching are lacking from the graduate (PhD and Master's) programs in the field of health sciences. The objectives of the study were to; 1) quantify the educational value of peer‐teaching activities in an anatomical sciences graduate program and; 2) assess graduate students’ perceived value of peer‐teaching in their learning and professional development. Over the two year period, first year graduate students enrolled in an introductory embryology course were randomized into groups of three and each group was assigned to teach one embryology concept to their classmates. To assess the value of the peer‐teaching exercise, each group members’ exam performance on the topic they taught were compared against topics they did not teach. Exam scores of the students on the peer‐taught topics were also compared with the scores on the instructor taught topics to assess whether being taught by the student peers had positive or negative effect on student learning. Students’ evaluations of the embryology course were also analyzed to assess students’ perception of the peer‐teaching project. The results reveal that students performed significantly better on the embryology topics that they taught to the class and that they retained the information better approximately one year after completion of the course. Students’ exam performances on the content taught by their peers vs. the instructor did not show significant differences. Analyses of students’ evaluation of the embryology course revealed that the teaching project was rated highly and mentioned as the most effective learning experience in the course. Students also remarked that the formal peer‐teaching project enhanced their level of confidence and ability to communicate well. Interestingly, the most commonly mentioned disadvantage about the teaching project was that students felt that they did not learn the content taught by their peers as well. In conclusion, the current findings indicate that peerteaching exercises implemented in a graduate curriculum has numerous positive impacts in student engagement, learning, long‐term retention and professional development with little to no evidence of negative impact despite students’ perception that they may not learn as much from their peers.

Support or Funding Information

Master of Science Program in Modern Human Anatomy, University of Colorado School of Medicine
A Look at Questions asked in Gross Anatomy Lab: An Analysis at Indiana University School of Medicine ‐ Bloomington
Authors: Taylor Melissa
Published: November 2023

Medical education is shifting to a more integrated approach in many schools across the country. At Indiana University School of Medicine – Bloomington, the Gross Anatomy course has incorporated multiple approaches to integrate both lab and lecture material. One way this integration occurs is by asking both identification and steeplechase questions on lab examinations. Steeplechase questions are where an identification question is asked about a tagged structure, and then it is followed up with a question about the embryological origin, innervation, function, or clinical significance of that structure. This study examines first year medical students’ perception of integration within the Gross Anatomy class. Surveys asking about the perceived difficulty of the identification and steeplechase questions were given to the students. It was primarily a quantitative survey, but the students had the chance to answer qualitative questions to expand on their answers to the quantitative questions. The surveys were given out after the first set of exams in fall, and again after their second to last set of exams in spring. Data taken from the survey were analyzed to find the most common responses to the questions. The fall surveys were compared to the spring surveys as well to see if there were any changes in responses among the students. Some of the challenges of integrating lab and lecture material that were indicated by the students in the free response questions included the instructors not talking about the significance of structures in lab, not having enough time to think through the answer during the exam, and knowing the structure tagged but not quite knowing the functions or clinical applications of the structure. Students also reported different ways they tried to integrate lab and lecture while studying. These responses included looking at the atlas or dissector while studying for lecture and drawing pictures of the structures while learning the lecture material.
A Cadaveric Procedural Anatomy Course Enhances Operative Competence
Authors: Sharma Gaurav , Aycart Mario A. , van Houten Trudy , Smink Douglas S. , Askari Reza , Gates Jonathan D.
Published: November 2023

Background

Inadequate anatomy training has been cited as a major contributor to declines in surgical resident operative competence and confidence. We report the impact of a procedurallyoriented general surgery cadaveric dissection course on trainee operative confidence and competence.

Methods

After obtaining IRB approval, postgraduate year 2 and 3 general surgery residents were prospectively enrolled into two cohorts: (1) an intervention group (n=7) participating in an 8week procedurally‐oriented cadaver course, and (2) controls (n=7) given access to course materials without participation in cadaver dissection. At both the beginning and end, we utilized two evaluation instruments: (1) an oral examination based on the American Board of Surgery Certifying Examination using standardized templates, and (2) a questionnaire assessing operative confidence.

Results

There were no intergroup differences in baseline characteristics. Residents who took the anatomy course had significantly higher improvements in examination scores on common bile duct exploration (CBDE) (33%±8% v. 10%±7%, p=0.04), femoral endarterectomy (43%±5% v. 11%±7%, p=0.003), fasciotomies (55%±10% v. 22%±9%, p=0.04), inguinal hernia repair (20%±9% v. −14%±5%, p=0.005), superior mesenteric artery (SMA) embolectomy (38%±10% v. 2%±11%, p=0.04), and overall (31%±4% v. 8%±3%, p=0.0006) (Figure 1.) In addition, they reported higher operative confidence on CBDE (p=0.008) and SMA embolectomy (p=0.02), and a trend towards higher overall operative confidence (p=0.06.)

Conclusions

We demonstrate that a replicable procedurally‐oriented cadaver course covering a wide range of essential general surgery procedures resulted in significant improvements in self‐reported operative confidence and competence as assessed by oral examination modeled on the American Board of Surgery's examination required for board certification. This work highlights the critical role that partnership between anatomists and clinicians can play in enhancing graduate medical education.
The Changing Face of Histology: An Old Idea for a New Era
Authors: Shaw Phyllis Ann
Published: November 2023

Curricular reform in medical education and a desire to use novel educational strategies that enhance student's appreciation of clinical reasoning, disease diagnosis, treatment, and global health, within a competency based framework, has resulted in a reduction in the number of hours allotted for the basic sciences, particularly histology. This trend across medical education was partly aided by the existence of computer‐assisted instruction designed to enhance or replace traditional teaching methods. One such strategy was the introduction of the Virtual Microscope in histology, a computer‐based program enabling viewing, navigating, and annotation of digital slides of thin sections of tissues and organs. With this tool in hand it became easy to manipulate histology into different teaching venues. With the introduction of new curricular additions into the first year curriculum, it became necessary to decrease the number of hours of some courses and to integrate others. At Icahn School of Medicine at Mount Sinai, histology (22 hrs) was integrated into the Structures course (nine‐weeks; 140 hours), which includes gross anatomy and embryology (18 hrs). The idea of merging these three disciplines is not new; Flexner stated in 1910, “… in addition to gross anatomy the student must make out under the microscope normal cellular structures and grasp the whole process of human development. Histology and embryology are essential aspects of anatomical study.” (Flexner Report, p. 25) What is new is the reduction in hours and the time in which the course material is taught. We present here the histology for the new era.
Digital Microscopy: A New Method for Histology Teaching
Authors: Romana‐Souza Bruna , Santos‐Silva Marco Aurélio , Porto Luís Cristóvão , Monte‐Alto‐Costa Andréa
Published: November 2023

The use of digital microscopy combined with Internet facilities has increased in the Histology and Pathology teaching. The aim of this study was evaluated the use of digital microscopy on Histology teaching in the Rio de Janeiro State University. For this, tissue and organ slides were digitalized with Pannoramic Midi (3DHistech, Budapeste) and histological structures were identified in the images using Pannoramic viewer (3DHistech). A script was prepared to facilitate the visualization of the image set of each histologic topic by the students. At the end of classes, students’ opinions about digital microscopy were assessed by a voluntary questionnaire, either in paper. In addition, students (n=59) made the histological diagnose test in two forms: image projection and online test. The students’ grades in each test were compared using paired t test. From 2013 to 2015, the digital microscopy was evaluated by 114 dental students, which assigned informed consent term. The majority of students (77 percent) found the digital microscopy easy to use, and 96 percent reported that digital microscopy facilitated the identification of the specific structures. Fifty‐five percent of students said they learned with digital microscopy more than with microscopic based study. In addition, only 30 percent of students reported that they preferred the microscopic lessons. There was no significant difference between students’ grades when compared to practical tests with image (7.8 ± 2.0) and online test (7.6 ± 2.0) (p>0.05). In conclusion, digital microscopy was found to be evaluated very positively by dental and medical students and may improve learning and productivity in the histology classes.

Support or Funding Information

Coordination for the Improvement of Higher Education Personnel (CAPES) – Edital Pró‐Ensino em Saúde; Carlos Chagas Filho Foundation for Research Support in the State of Rio de Janeiro (FAPERJ).
The Use of Facebook to Support Anatomy Learning
Authors: El‐Sherbiny Mohamed , Eladl Mohamed Ahmed , Abdalla Mohamed Elhassan
Published: November 2023

Background

In the era of innovation in medical education, students’ learning has shifted from the conventional classroom learning to be both inside and outside the classroom. Thus, the traditional way of teaching is anatomy has changed dramatically to comply with the need of the new curricula and new generation. It is well known that the new technologies especially social media is taking part in education in general and medical education in particular.

There has been little work investigating how students interact with social networks in an educational context. In this study, our aim was to investigate the students’ perception of using Facebook and an educational support in learning anatomy. The study took place during the spring semester 2015 in Almaarifa College of Medicine, Riyadh, Saudi Arabia using the Human Anatomy and Embryology Facebook Page, which was developed by an anatomist from another university.

Methodology

A total number of 100 specific posts from Human Anatomy and Embryology Facebook Page were selected and introduced to the students during teaching Anatomy and Embryology. These posts are well related to the running courses in year one and two (total number of students is 200). Students’ perception (N=102) regarding suitability and effectiveness of this approach was sought through a self‐administered questionnaire, using a five‐response Likert‐type scale. These quantitative data were analyzed using SPSS statistical software. In addition, interviews were conducted with 10 Students to discuss how this reflects on their way of anatomy learning.

Results

The survey indicated that 90% agreed that these links provide opportunities to improve communication between students and staff and facilitate interaction between groups of students in ways that enhance their anatomy learning. 87% of the students agreed that the Links were an efficient tool to highlight the learning objectives. 92% of the students think that their motivation to discuss the practical classes was enhanced when they receive these links from their instructor. 85% of the students stated that this way encourage them to reflect on their learning.

The majority of the students interviewed agreed that it's much better to have similar to these pages administered by their instructors. Many assumed that it is a simple way for tracking the students beyond the classroom. Some students stated that Facebook usually takes them away and waste their time.

Conclusion

Facebook offers opportunities for efficient communication and learning, and there are still issues worthy of consideration, such as being ingrained with entertainment, lack of direct supervision and exaggerated informational convergence.
Development and Use of a Web‐Based Human Dissection Video Library at MCW
Authors: Biggs Philip , Pierce Douglas , Hoagland Todd
Published: November 2023

Introduction

Using funding through class gifts established by alumni, we have created an online library of dissection videos to further aid MCW Clinical Human Anatomy (CHA) students in their work. Our goal is to help students better understand key structures, improve their dissections, dissect more efficiently, and prepare for exams. In addition, the video library can be used at satellite locations to assist remote anatomy faculty and homogenize the dissection experience MCW provides.

Methods

We dissected a male and female cadaver following the M1 dissection manual, taking instructional video footage at discrete points. The finished dissection videos have been uploaded to an Amazon S3 server where they can be accessed by students through an online portal we created. These videos are accessible through computer, tablet, or smartphone.

Results

Lab group efficacy data will be collected via survey and compared to previous years’ data. Additional objective indicators include website requests timestamped by the Amazon server, practical exam scores, and dissection grades.

Conclusion/Discussion

We hope that our project results in a very useful resource for students in the anatomy lab to achieve listed lab objectives, identify key structures, and improve the quality and efficacy of their work. We also hope to have provided a beneficial study aid to prepare students for the anatomy exams. Early subjective reports from faculty and students at MCW's new satellite campus in Green Bay indicate that the video library has been immensely valuable in establishing the course.

Support or Funding Information

Funding from MCW Class of 1980
Correlation Between Pre Medical Exposure to Anatomy and Performance in Medical Gross Anatomy
Authors: Robertson Ellen M , Notebaert Andrew J , Sinning Allan R , Darling Ryan D
Published: November 2023

Medical students are often faced with a large volume of basic science content during their first year of medical school, and performance in these courses can weigh heavily on their future career opportunities. The University of Mississippi Medical Center (UMMC) is the state's only academic medical center, and admission is typically limited to Mississippi residents. Although there is no anatomy prerequisite for admission, there are many opportunities for pre‐health students to receive anatomical experience within undergraduate institutions and Master's graduate programs. A growing number of entering medical students are participating in a few, single‐year preparatory graduate programs designed specifically to facilitate admission into medical and dental programs. The aim of this research was to determine if there was any correlation between previous exposure to pre‐health Anatomy courses, whether undergraduate or graduate, and performance in Medical Gross Anatomy. This study correlated admissions variables (e.g. sex, age, undergraduate GPA, prior anatomy coursework, MCAT score, prior health professions experience) with various measures of Medical Gross Anatomy course performance and first semester GPA. Initial results indicate that with an average class size of 145, less than 1/3 of incoming students have any anatomy coursework prior to taking medical gross anatomy. Additional analyses will examine correlations with other admissions data and may be used to help advise students on how best to prepare for medical school. Results may also serve as bi‐directional validation of admissions criteria and medical school performance. Medical school admissions requirements can be re‐evaluated, the composition of dissection groups can be strategically selected, and at‐risk students may be identified for participation in early intervention options.
Optional online quizzes increase student success on exams in an undergraduate human anatomy course
Authors: Richardson Nicolette
Published: November 2023

Background

Repeated testing of material through online quizzing has been shown to improve student test scores in medical school human anatomy courses, however this has not been examined in undergraduate students. Since many undergraduate human anatomy programs do not have access to cadaveric material for learning/assessment, virtual dissection and related testing could be a successful alternative.

Objective

The present study examined student success on a midterm and final exam following two optional online quizzes covering similar material as the exams in an upper level undergraduate regional human anatomy course. Quiz questions were developed from virtual dissection labs which all students completed. We hypothesized that students who chose to complete the optional quizzes would be more successful on the exams, regardless of their level of success on the quizzes.

Methods

113 kinesiology and physical therapy students, in their third or fourth year of undergraduate study, were enrolled in a Regional Human Anatomy course over the fall of 2014 or winter of 2015. All students wrote a midterm and final exam, and had the option to also complete two online quizzes, each worth 10% of the final grade and incorporating bell‐ringer style, timed, questions relating to a virtual dissection image. If students chose not to complete Quiz 1, that 10% would be applied to the midterm, and if they chose not to complete Quiz 2, that 10% would be applied to the final exam. The material covered in the quizzes was the same as that on the corresponding exams. Students were free to choose to do both quizzes, one quiz, or none.

Results

56 students chose to complete at least one quiz, while 57 did not complete any quizzes. Students who completed Quiz 1 were more successful on the midterm (77.1 ± 13.4 compared to 72.4 ± 14.9%, p < 0.05) and students who completed Quiz 2 were more successful on the final exam (71.2 ± 16.9 compared to 60.9 ± 15.9%, p < 0.05, compared to those students who did not complete the respective quizzes.

Conclusions

Completion of optional online quizzes improves student success on exams covering similar material in an undergraduate human anatomy course. For undergraduate courses with or without a laboratory component, this may be a useful method to improve student retention and test scores.

Support or Funding Information

Supported by a Dean's Catalyst e‐Learning Grant, Faculty of Health, York University
Endotoxin‐Stimulated Hepatic Stellate Cells Increase Suppressive Potential of Regulatory T Cells via IDO‐Mediated AhR Activation: Therapeutic Implications
Authors: Kumar Sudhir , Dangi Anil , Gandhi Chandrashekhar R
Published: November 2023

Due to adverse effects of the pharmacological drugs, use of immunosuppressive CD4+Foxp3+ regulatory T cells (Tregs) is an attractive and preferred approach to promote immunological tolerance. However, poor in vivo stability of the ex vivo expanded Tregs, and their conversion to injurious effector immune cells are major drawbacks. We reported earlier that hepatic stellate cells (HSCs) cause expansion and increase suppressive function of allogeneic Tregs; lipopolysaccharide (LPS) pretreatment of HSCs augment the expansion of Tregs. The aim of this study was to delineate the mechanisms underlying HSC‐induced expansion, increased potency and in vivo stability of Tregs. HSCs and Tregs were isolated from allogeneic mouse livers and spleens, respectively. Following co‐culture with untreated or LPS‐pretreated HSCs, proliferation of Tregs was measured by CFSE‐dilution method, and Foxp3 expression and its acetylation were determined via immunoprecipitation and Western blotting analyses. Expression of various genes was determined via quantitative RT‐PCR. Ex vivo HSC‐expanded Tregs were highly stable in vivo following adoptive transfer into mice and retained their increased suppressive property. LPS increased the expression and activity of immunoregulatory enzyme indoleamine 2,3‐dioxygenase 1 (IDO1) in HSCs, and LPS‐pretreated HSCs stimulated aryl hydrocarbon receptor (AhR) signaling in Tregs. Compared to WT HSCs, IDO1−/− HSCs were much inferior in stimulating expansion of Tregs and their Foxp3 expression. Pharmacologic blocking of IDO by 1‐methyl tryptophan in HSCs prevented AhR signaling, Foxp3 expression and expansion of Tregs. The HSC/IDO‐dependent increased acetylation of lysine residues of Foxp3 was associated with stability and competitive fitness of Tregs. Finally, HSCs stored frozen following 2–3 subcultures were much more potent than freshly isolated HSCs in expanding Tregs, thus providing a mode for clinical application. We conclude that HSCs cause expansion of allogeneic Tregs through IDO‐dependent AhR‐mediated signaling mechanism, and increase their stability through lysine‐acetylation of Foxp3. Importantly, availability of frozen HSCs for ex vivo expansion of Tregs provides an exciting therapeutic opportunity for immunological disorders.

Support or Funding Information

Supported by a VA Merit Review Award (1IO1BX001174) and grants from NIH (PO1AIO81678 and R21AA020846) to CRG.
The Influence of Spatial Ability on Medical Student Performance in the Basic Sciences
Authors: Willis Anna , Edmondson Anna , Martin Charys
Published: November 2023

Background

Spatial visualization ability (Vz) is associated with higher performance in anatomy; however, the influence of Vz on performance in the other basic sciences has not been established. This study aimed to assess the influence of Vz on academic performance in the first year basic science curriculum at the Medical College of Georgia. We hypothesized that students’ Vz will have a significant positive correlation with their performance in structural science components (anatomy, embryology, histology, and neuroscience) and the systems‐based modules focusing on structural science.

Methods

First year medical students (n=83) in a systems‐based integrated curriculum completed the Mental Rotations Test (MRT) at the beginning of the year prior to the start of anatomy to establish Vz (pre‐Vz). Students completed the MRT again at the end of the year to reassess Vz (post‐Vz). Academic performance was assessed via grades in each basic science component (anatomy, biochemistry, embryology, histology, neuroscience, and physiology) and systems‐based module (Cellular and Molecular Basis of Medicine, Tissue and Musculoskeletal System, Cardiopulmonary System, Gastrointestinal and Urinary Systems, Endocrine‐Reproductive Systems, Head and Neck and Special Senses, and Medical Neuroscience).

Results

A two‐tailed T‐test determined that there was a significant difference between pre‐Vz and post‐Vz (12.9±4.72; 16.0±4.85 respectively, p≤0.05). ANCOVA analysis demonstrated significant positive correlations between pre‐Vz and performance in histology (r2=0.117), the Cardiopulmonary module (r2=0.114), and the Head and Neck and Special Senses module ((r2=0.092), p=<0.05). Significant positive correlations were found between post‐Vz and performance in anatomy (r2=0.106), histology (r2=0.130), neuroscience (r2=0.114), physiology (r2=0.095), the Tissue and Musculoskeletal System module (r2=0.086), the Cardiopulmonary module (r2=0.131), the Gastrointestinal and Urinary module (r2=0.094), the Head and Neck and Special Senses module (r2=0.158), and the Medical Neuroscience module ((r2=0.050), p≤0.05).

Conclusions

In summary, performance in one component and two modules were positively correlated with pre‐Vz scores while performance in four components and five modules were positively correlated with post‐Vz scores. These results suggest that acquired Vz, as opposed to Vz at the beginning of the year, is associated with improved performance in the basic sciences within the first year medical curriculum. This indicates that training medical students to improve their Vz may be beneficial for medical school performance. Future studies are required to assess how Vz changes throughout the first year curriculum to determine how a change in Vz correlates with student performance within the basic sciences.
Effect of Spatial Ability on Enhancing Neuroanatomy Education with an Interactive 3D E‐learning Module
Authors: Allen Lauren , Eagleson Roy , deRibaupierre Sandrine
Published: November 2023

Neuroanatomy is one of the most challenging topics in anatomy with many medical students and novice residents reporting they have the least amount of knowledge in the clinical neurological sciences, consider it to be the most difficult subject area, and have the lowest confidence in their diagnosis of patients with neurological complaints. A main reason for the reported challenges is the difficulty in developing a clear understanding of highly‐complex spatial relationships that exist between structures in neuroanatomy. The implementation of interactive three‐dimensional (3D) models into neuroanatomy curricula may provide an effective solution for mitigating the difficulties in spatial knowledge encountered by students using conventional learning resources, however this has yet to be fully examined in the literature.

An interactive 3D e‐learning module was developed to complement gross anatomy laboratory instruction. The module provided students the opportunity to manipulate a dynamic 3D model to view structures from any desired angle, view deep cortical structures at high magnification, and add interactive structural labels.

Eighty‐seven participants completed the study, which utilized a cross‐over design, to divide participants into two groups. Each group completed baseline anatomy knowledge and spatial ability assessments, followed by access to either the 3D e‐learning module or gross anatomy laboratory. Participants completed the first post‐module anatomy knowledge assessment prior to switching to the other learning modality. A final post‐module knowledge assessment was administered following student exposure to the second learning modality.

No baseline differences were observed between groups. Students who initially accessed the 3D module scored significantly higher on the first post‐module knowledge assessment than the students who initially accessed the gross anatomy laboratory. Students who accessed the 3D learning resources following gross anatomy resources, significantly improved on the final post‐module knowledge assessment. A negative correlation was observed between spatial ability and change in assessment score following access to the 3D module suggesting that students with low spatial ability experienced a greater positive effect on their learning of neuroanatomy following the use of the 3D learning module than students with higher spatial ability. Results of this study could be used to guide the effective development and implementations of efficacious 3D e‐learning resources to improve neuroanatomical instruction.

Support or Funding Information

Ontario Graduate Scholarship
Generation of a Foxc2 Gene Knockout Murine Melanoma Cell Line via CRISPR Cas9 Genome Editing Technology
Authors: Thompson Jefferson , Hargadon Kristian
Published: November 2023

Melanoma is a leading cause of cancer‐related deaths each year, and murine model systems for the study of this disease are important tools for investigating factors that regulate the growth and metastasis of this cancer. The B16‐F1 melanoma is a well‐characterized murine cell line that is characterized by rapid growth and metastasis to local tumor‐draining lymph nodes. The D5.1G4 cell line is a mutated variant of B16 melanoma that grows slowly and does not invade regional lymph nodes. Recent whole genome expression microarray analysis of these cell lines revealed enhanced expression in B16‐F1 melanoma of the Foxc2 gene, which encodes a transcription factor that has been shown to regulate cell growth, proliferation, differentiation, and longevity. We hypothesized that the FOXC2 transcription factor might also promote lymph node metastasis by B16‐F1 melanoma. To investigate this possibility, we employed a CRISPR‐Cas9 genome editing approach to knock out the Foxc2 gene in B16‐F1 melanoma. The generation of the resulting B16‐F1DFoxc2 melanoma cell line and its utility as a model to study the role of FOXC2 in tumor progression and metastasis are described herein.

Support or Funding Information

Commonwealth Health Research Board, Virginia Academy of Science Jeffress Memorial Fellowship, Virginia Foundation for Independent Colleges Undergraduate Science Research Fellowship, Hampden‐Sydney College Honors Council
Nuclear Extracts Enzymatically Convert M1dG to 6‐oxo‐M1dG in Duplex DNA
Authors: Mitchener Michelle M. , Wauchope Orrette R. , Marnett Lawrence J.
Published: November 2023

Lipid and DNA peroxidation give rise to DNA adducts, the most abundant of which is 3‐(2‐deoxy‐β‐D‐erythro‐pentofuranosyl)pyrimido[1,2‐α]purin‐10(3H)‐one (M1dG). Increased levels of this adduct are positively correlated with a variety of physiological and pathophysiological conditions including aging, bacterial infection, and cancer. Recently, our laboratory reported the oxidative metabolism of M1dG to 6‐oxo‐M1dG in nuclear DNA isolated from multiple human and rodent cell lines, suggesting the presence of an activity responsible for conversion of M1dG to 6‐oxo‐M1dG in double‐stranded DNA. Nuclear extracts from RAW264.7 cells were prepared and incubated with double‐stranded oligonucleotides containing M1dG. Following incubation, the oligonucleotides were digested and analyzed for the presence of 6‐oxo‐M1dG. Heat‐denaturation or Proteinase K‐treatment of the nuclear lysates ablated conversion, indicating that the oxidation is an enzyme‐mediated process. We hypothesized that this enzyme might be an alpha‐ketoglutarate‐dependent dioxygenase, a class of iron‐dependent enzymes that is responsible for the oxidation of various alkylated nucleic acids and/or amino acids. Indeed, we found that preincubation of nuclear lysates with EDTA or metals known to displace ferrous ion from proteins, resulted in a decrease in 6‐oxo‐M1dG formation upon incubation of the lysates with the M1dG‐containing oligonucleotide. Conversely, preincubation with ferrous ion, but not ferric ion, increased the amount of 6‐oxo‐M1dG formed. Additionally, nuclear lysates preincubated with either N‐oxalylglycine or IOX1, two structurally distinct broad‐spectrum alpha‐ketoglutarate‐dependent dioxygenase inhibitors, showed reduced 6‐oxo‐M1dG formation compared to their control counterparts. These findings indicate the presence of a nuclear enzyme, conceivably an alpha‐ketoglutarate‐dependent dioxygenase, capable of converting M1dG to 6‐oxo‐M1dG in double‐stranded DNA.

Support or Funding Information

This work was supported by grants from the National Institutes of Health (R37 CA0878819 to L.J.M.) and US Public Health Services (T32 ES007028 to M.M.M.).
Kinetic mechanism for binding and flipping of damaged bases by DNA repair dealkylases
Authors: O'Brien Patrick
Published: November 2023

DNA is susceptible to alkylation by endogenous metabolites and by exogenous reactive species and multiple pathways have evolved to detect and repair the sites of alkylation damage. The best characterized pathway employs DNA repair glycosylases to remove alkylated bases and initiate the multi‐step base excision repair pathway. In contrast, the AlkB family of direct repair enzymes use oxygen, iron(II) and 2‐oxoglutarate to catalyze the oxidative removal of alkyl groups from nucleobases and restore them to their natural structures in a single step. Structural work shows that base flipping is used to bring the alkylated base into proximity of the catalytic iron, but kinetic studies have been difficult and crucial information is lacking regarding the timing of the searching, flipping and chemical steps. We have used equilibrium binding and transient kinetic studies to define the minimal kinetic mechanism for AlkB enzymes. We compare this mechanism to that which is employed by DNA repair glycosylases. Interesting parallels between these different pathways have been uncovered that provide insight into the fundamental problem of how aberrant methyl groups can be detected in duplex DNA. However, there are also several differences that are relevant to pathway choice in cells where both pathways are operational.
Exploration of the Atypical Regions of the Plasmodium falciparum Apicoplast DNA Polymerase and Their Potential Role in Antimalarial Drug Discovery
Authors: Milton Morgan E. , Honzatko Richard B , Nelson Scott W
Published: November 2023

Plasmodium falciparum, the primary cause of malaria in humans, contains a plastid‐like organelle called the apicoplast. The apicoplast exists in most parasitic members of the phylum Apicomplexa and has its own genome along with organelle‐specific enzymes for DNA replication and repair. The only DNA polymerase in the apicoplast, apPOL, is an atypical A‐family polymerase. We solved the crystal structure of P. falciparum apPOL, the first atypical A‐family polymerase to be structurally characterized. apPOL diverges from typical members in two of three previously identified signature motifs and a region not implicated by sequence. Moreover, apPOL has an additional N‐terminal subdomain that may bind DNA, participate in protein‐protein interactions, and/or stabilize its DNA proofreading domain. These structural variances may account for functional differences in polymerase activity. The structure of apPOL also provides a point of departure for structure‐based antimalarial drug design and these atypical regions could be targeted for potent and specific inhibitors. Since apPOL has no direct orthologs to mammalian polymerases, P. falciparum apPOL is an attractive anti‐malarial drug target that provides structural and biochemical insight into a poor characterized subgroup of A‐family polymerases.
Heterologous Expression of the Human Polybromo‐1 Protein in the Methylotrophic Yeast Pichia pastoris
Authors: Hopson Sarah , Thompson Martin
Published: November 2023

The human polybromo‐1 protein (BAF180) is known to be a driver mutation in clear cell renal cell carcinoma, where it is mutated in approximately 40% of cases. In its native form, BAF180 is the chromatin‐targeting subunit of the PBAF complex. The precise interactions of BAF180 with the nucleosome are unknown because the recombinant full‐length BAF180 protein has not been available for investigations; only phenomenological studies using BAF180 expressed in mammalian cells have been conducted. BAF180 (encoded by the PBRM1 gene) has nine domains: six bromodomains, two BAH (bromo‐adjacent homology) domains, and one HMG (high mobility group) box. Bromodomains are known to recognize acetylated‐lysines on histones; it is believed that these domains play a crucial role in nucleosome recognition. The BAH domains are critical for the ubiquitination of PCNA, a key regulator of DNA damage. The HMG box is known to be a DNA‐binding domain. Most often, the mutations seen in cancers are truncations, wherein one or more domains have been deleted. Deletion of the bromodomains might prevent recognition of a specific acetylated‐lysine on a histone, impeding the recruitment of the complete PBAF complex. The mutants without the BAH domains may be unable to ubiquitinate PCNA and so cannot overcome DNA damage. Deletion of the HMG box could prevent the recognition and/or binding of BAF180 to gene sites. It can therefore be inferred that mutations in BAF180, especially truncations, have a key role in the progression of cancer, possibly through the interactions noted above. Here we report the successful expression of the full‐length BAF180 protein using the GAP promoter in the heterologous host Pichia pastoris. The ability to express full‐length and mutated BAF180 will allow for biophysical binding studies. Knowledge of the binding interactions is critical for us to understand the role of BAF180 in cancer development and its progression.

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Michigan Technological University
Single‐Molecule Analysis of Glucocorticoid Receptor and Cofactor Action in Living Cells
Authors: Paakinaho Ville , Presman Diego M , Ball David , Karpova Tatiana S , Schiltz R Louis , Levitt Peter , Morisaki Tatsuya , Mazza Davide , Lavis Luke D , Hager Gordon L
Published: November 2023

The glucocorticoid receptor (GR) is a hormone‐regulated transcription factor (TF) that plays a central role in metabolic regulation and anti‐inflammatory activities. Population‐based assays such as ChIP‐seq have historically been utilized to investigate the interactions of TFs to DNA. However the dynamic binding behavior of these factors in living cells remains unclear. We have examined the behavior of GR and a number of its known cofactors; AP‐1, NF‐kB, GRIP1, and BRG1 at the single‐molecule level in living cells. These factors were fused with either Halo or Snap tags, and labeled with bright and stable fluorophore JF549. Single‐molecule tracking of these proteins (using HILO microscopy) reveals a highly dynamic binding behavior of GR and its cofactors. This supports transient rather than stable TF chromatin interactions. Specifically, two distinct binding populations have been observed for all factors tested; fast or slow stops. Fast stops have residence times of ~1 sec, whereas slow stops range between 6 and 14 sec. The majority of molecules remain unbound or exhibit fast stops, while only a small percentage exhibit slow stops. However, hormone activation of GR results in an increase in the percentage of molecules with slow stops compared to the unstimulated state. Additionally, the residence time of several cofactors is increased upon GR activation. Importantly, disrupting the interaction of GR and its cofactors decreases the factor's residence time, and proportions of molecules with slow stops. These data support the concept that slow stops represent functional binding events at specific response elements. Our results indicate that only a small proportion of GR and its cofactors are functionally bound at any given time. In conclusion, our single‐molecule observations affirm the general model that many TFs are highly dynamic in their chromatin binding activity.

Support or Funding Information

This research was supported by grants from the Intramural Research Program of the National Institutes of Health, National Cancer Institute, Center for Cancer Research. Ville Paakinaho supported by the Sigrid Jusélius Foundation.