bluuebunny/crossref_metadata_2025_split huggingface dataset:
Does the Use of Virtual Microscopy Enhance Student Collaboration and Content Mastery in an Undergraduate Human Anatomy Course?
Authors: O'Loughlin Valerie Dean , Braun Mark W. 
Published: June 2021

Virtual microscopy allows students to review microscopic slides via a computer interface that simulates a standard optical microscope. A number of studies have been published examining the use of virtual microscopy in medical and professional schools. However, little is known about the use of the virtual microscopy in undergraduate anatomy courses, an academic setting where learners may be less self‐sufficient than their medical school counterparts.We implemented the use of virtual microscopy in Indiana University's Basic Human Anatomy (A215) course beginning the summer of 2008. This undergraduate course enrolls over 400 students per semester, has many graduate teaching assistants (TAs), and until the summer session 2008 had used standard optical microscopes for histology. This study reports academic success and student satisfaction following implementation of virtual microscopy. Subject mastery was assessed by comparing aggregate lab exam scores before and after introduction of this technology. Student satisfaction was assessed by means of an online survey. Additionally, TAs were interviewed regarding how their instruction and students' learning may have been affected by the use of virtual microscopy.Students who utilized virtual microscopy performed much better on lab exams than students from previous semesters who used standard optical microscopes. There was increased student and TA satisfaction with virtual microscopy and more time was spent learning the material (versus learning how to use the microscope). However, student collaboration was not necessarily increased, unless the TAs were proactive and inspired collaboration among students. Our study indicates virtual microscopy is a valuable teaching tool in the undergraduate anatomy setting, but instructors may have to guide their students in utilizing this tool to its fullest potential.
Separating genetic and hemodynamic defects in neuropilin 1
Authors: Jones Elizabeth A.V. , Yuan Li , Breant Christiane , Watts Ryan , Eichmann Anne 
Published: June 2021

Formation of the cardiovascular system is crucial for embryo growth and survival and the importance of proper blood flow even during these early stages is becoming increasingly clear. In recent years, there has been a debate regarding which aspects of early vascular formation are genetically predetermined, and which are governed by external stimuli, such as mechanical and biochemical signaling. Though the initial vascular network is patterned without knowledge of the functional requirements, it makes biological sense that a feedback mechanism with respect to physiological function would set in as soon as this information becomes available. We recently showed that physical forces created by blood flow are necessary for proper vascular development and remodeling. In this study, we show how to distinguish between genetic defects and biomechanical defects during vascular development. Using mouse embryo culture, we study hemodynamic defects in Nrp1−/− mice together with an analysis of the emerging vascular defects. The geometry of yolk sac blood vessels is altered and remodeling into yolk sac arteries and veins does not occur. To separate flow‐induced deficiencies from those caused by the nrp‐1 mutation, we arrested blood flow in cultured wild‐type and mutant embryos and followed their vascular development. This method allows genetic defects caused by loss‐of‐function of a gene important for cardiovascular development to be isolated even in the presence of hemodynamic defects.Grant Funding SourceNSERC
Effect on blood pressure of diets enriched with different sources of n‐3 fatty acids in healthy adults
Authors: Teo Choon Chew , Grakov Stoyan , Chiu Hsueh‐Ting , Oda Keiji , Sabaté Joan 
Published: June 2021

BackgroundConsumption of n‐3 fatty acids from algal‐oil supplements and plant sources produce health benefits, which may be dependent on the reduction in blood pressure.Aim and MethodsTo determine if plant sources (flaxseed oil and walnuts) of á‐linolenic acid (ALA) produce similar change in blood pressure (BP) as algal‐oil (EPA/DHA) supplements, we performed a randomized 4x3 cross‐over study (4 diets and 3 8‐week study periods) in 24 healthy adults (15 women, 9 men; mean±SE age 42±2.7 years; BMI 25.4±0.9 kg/m2). Under controlled feeding conditions, subjects consumed eucaloric lacto‐ovo vegetarian diets: Control, ALA (6‐7g/2400 kcal/d), EPA/DHA (0.20/0.72g EPA/DHA per 2400 kcal/d), and, Combination (ALA + EPA/DHA). Under controlled conditions, 6 BP readings, (3/day on 2 days) were taken at the beginning and end of each diet period.ResultsSignificant (p < 0.001) reduction in systolic BP were observed in all four diets: Control (‐2.64%), EPA/DHA (‐2.42%), ALA (‐1.64%) and Combination (‐1.85%) while non‐significant (p > 0.05) reduction were observed in the diastolic BP: Control (‐2.03%), EPA/DHA (‐2.51%), ALA (‐0.05%) and no change for the Combination diets (0.0%). No significant differences in BP between diets were observed.ConclusionFollowing diets enriched with ALA, EPA/DHA or a combination of these fatty acids for 8 weeks do not seem to affect BP when compared with the control diet.
Remodeling of data in the 2004 Canadian Community Health Survey 2.2 (CCHS) using actual rather than mandated levels of folic acid fortification suggests a lower prevalence of inadequacy of folate in women of reproductive age
Authors: Shakur Yaseer A , O'Connor Deborah L 
Published: June 2021

Folic acid (FA) fortification of grain products has been mandatory in Canada for 10 years. Previously we reported that foods are over‐fortified by approximately 50% of the values in Canada's main food composition database, the Canadian Nutrient File. We used SIDE to calculate usual intakes of folate based on mandated and actual levels (based on 50% overage) of FA fortification from 24‐hour dietary recall data of approximately 35,000 respondents in the CCHS. In women of reproductive age, the prevalence of inadequacy (intakes below the Estimated Average Requirement) based on actual levels decreased by more than half when compared to that based on mandated levels (27.3% to 12.4% in 14‐18y; 24.5% to 10.2% in 19‐30y; 28.1% to 14.2% in 31‐50y). A similar decline was observed in lactating females (27.7% to 12%), while in pregnant females, the decline was more pronounced (50.2% to 18.4%). In sum, given its protective role in the prevention of neural tube defects, women capable of becoming pregnant should consume a FA supplement; however, at actual levels of FA fortification in the Canadian food supply, the prevalence of inadequacy in women of reproductive age is lower than estimated using mandated levels.Grant Funding SourceResearch Training Award
Lymphomonocyte subpopulations, activation and cytokine production in Alzheimer's Disease (AD)
Authors: Pellicanò Mariavaleria , Colonna‐Romano Giuseppina , Bulati Matteo , Barbagallo Mario , Di Prima Anna , Misiano Gabriella , Di Carlo Marta , Vasto Sonya , Candore Giuseppina , Caruso Calogero 
Published: June 2021

AD is a neurodegenerative illness characterized by accumulation of β‐amyloid (A β‐42) and inflammation. To investigate the systemic signs of immune processes in AD we examined lymphomonocyte subpopulations (PBMCs) of 17 patients and 7 age‐matched healthy controls (HC). No differences were observed in T, B and NK subsets between the two groups, whereas an increase of both CD4+ and CD8+ naïve T cells was observed in AD patients. We analyzed AD and HC PBMCs after "in vitro" activation with Aβ‐42 and no differences were observed in the expression of early activation markers CD25 and CD69 on T and B cells, although AD cells show a basic activation. We also evaluated, on monocytes, the expression of the activation markers CD80 and HLA‐DR and of the receptor for fibrillar Aβ‐42, CD36. Here again no differences were observed between the two groups, even if there is a basic high expression of CD36 on AD cells. The evaluation of cytokines production after "in vitro" culture with Aβ‐42 shows an increased production of pro‐ and anti‐inflammatory cytokines and chemokines, in AD when compared to HC. These results, although puzzling, demonstrate an involvement of systemic immunity in AD patients.This work was supported by grants from the Italian Ministry of Education, University and Research (MIUR, ex 60%)
Energy metabolism during chronic REM sleep deprivation: the start of something big
Authors: Koban Michael 
Published: June 2021

In rodent models of chronic and unremitting sleep deprivation, hyperphagia develops after 5‐6 days. If the regimen is taken to 10‐20 days, food intake increases substantially irrespective of whether rats are fed chow or a palatable calorie‐dense liquid diet (Ensure); body weight does not increase. Moreover, in a new model of chronic sleep restriction, sleep deprivation is enforced for 20 hours followed by 4 hours of recovery in home cages, and this also leads to hyperphagia. Of importance is that despite greatly increased food intake in all paradigms, rats consistently fail to gain body weight. This can only happen if there is an increase in energy metabolism. Indeed, the resting metabolic rate of sleep‐deprived rats becomes elevated, mediated by robust up‐regulation of uncoupling protein 1 in brown adipose tissue. Additionally, gene expression of uncoupling protein 3 in skeletal muscle is strongly stimulated, although the role of this protein in thermogenesis remains controversial. Chronically sleep‐deprived rats show rapid mobilization of hepatic and muscle glycogen, followed by reduction in abdominal white adipose tissue. Despite a lack of weight gain, there is evidence to suggest that sleep deprivation/restriction leads to glucose dysregulation. For example, sleep‐deprived rats have a higher glucose:insulin ratio, and when challenged with an intraperitoneal glucose tolerance test, blood glucose of sleep‐restricted rats is higher than in controls. In summary, rat models of sleep deprivation/restriction may be useful tools in understanding the etiology of hyperphagia and suggest a dissociation between weight gain and glucose dysregulation and insulin resistance.Supported by NCRR RCMI and a Pilot and Feasibility grant from the Clinical Nutrition Research Unit of Maryland, P30DK072488.
Conserved Links Between Nutrient Signaling, Translation and Aging
Authors: Kennedy Brian , Steffen Kristan , Stanfel Monique , Burtner Chris , MacKay Vivian , Kaeberlein Matt 
Published: June 2021

Invertebrate model organisms have proven invaluable for aging research, leading to the identification of hundreds of aging genes. But why should we expect orthologs of worm or yeast aging genes to have similar effects in mammals? We have addressed this question, taking a quantitative approach to identify the extent of conservation between C. elegans and S. cerevisiae, which diverged over a billion years ago. Yeast orthologs of reported worm aging genes were identified and tested for their effects on replicative aging. We find that these orthologs are statistically more likely to modulate yeast aging than randomly chosen yeast genes. Ortholog pairs that modulate aging map to known pathways involved in nutrient responses, and mammalian counterparts to these genes are prime candidates for mammalian aging genes. We propose that this conservation exists not because genes have evolved to regulate aging but rather the organismal response to nutrient restriction, and longevity is tightly linked to this response.Dietary restriction extends lifespan in nearly all model organisms for aging research and delays the onset of a spectrum of age‐related diseases. We have attempted to define the pathways modulating the longevity‐specific effects of dietary restriction again using a multi‐organism approach. Studies in yeast and worms are consistent with reduced TOR signaling and altered translational control being a primary consequence of dietary restriction. Current studies are focused on achieving a mechanistic understanding of the links between altered translational control and aging, as well as testing these models in mice. Since these longevity pathways appear to be conserved, a better mechanistic understanding will likely define molecular targets in efforts increase human healthspan.
Murine epidermal progenitor cells have a low redox state
Authors: Carr Wanakee , Zhang Yuping , Oberley Christopher , Oberley Larry W , Dunnwald Martine 
Published: June 2021

The epidermis is a stratified cornified epithelium that protects the organism against physical and microbial insults. These environmental exposures can result in oxidative stress and affect cellular proliferation and differentiation. However, very few studies have evaluated the base line levels of reactive oxygen species (ROS) and antioxidant proteins in the epidermis or in the context of stem/progenitor cells, cellular types critical to the homeostasis of the epidermis. Here, we show that ROS are mainly produced by epidermal cells and that antioxidant proteins (MnSOD, GPx1, catalase) are differentially expressed in the epidermis. Using our previously sorted epidermal progenitor cells (side population, EpSPs) and more differentiated cells (non‐SPs), we show that catalase expression and activity are significantly decreased in EpSPs compared to non‐SPs. Furthermore, we found fewer peroxisomes per cell and decreased mitochondrial surface area in the EpSPs compared to non‐SPs. Using dihydroethidium (DHE), we show that EpSPs have less DHE signal compared to more differentiated cells. In summary, our data suggest that EpSPs have decreased levels of antioxidant proteins and ROS. Together, these studies indicate that the intracellular redox environment of EpSPs is reduced relative to their more differentiated progeny.Grant Funding SourceNational Institute of Health
Pax3 expression by satellite cells of avian skeletal muscle spindles
Authors: Kirkpatrick Lisa J , Rosser Benjamin WC 
Published: June 2021

Pax3 protein is usually co‐expressed with Pax7 by embryonic dermomyotome cells which give rise to skeletal muscle fibers. Following myogenesis, it is held that Pax3 expression becomes restricted to a few satellite cells (SCs) of select mature muscles. Intrafusal fibers of muscle spindles are thought to persist in an immature state as, unlike extrafusal fibers, they maintain small diameters, developmental myosins, Myf5 expression and high concentrations of SCs. Thus, we hypothesize that Pax3 expression is maintained in intrafusal fibers. Immunohistochemical methods were used to quantify nuclear numbers in chicken anterior latissimus dorsi muscles excised at 9, 30, 62, and 138 days post‐hatch. SCs were identified by their Pax7 expression. In intrafusal fibers, the percentage of SCs expressing Pax3 decreased from 76% at 9 days to 16% at 138 days post‐hatch and, at each age studied, was higher in intrafusal than extrafusal fibers. In extrafusal fibers, after 14% at 9 days, only 0‐2% of SCs expressed Pax3. Muscle spindles offer a novel model for the study of Pax3 expression in SCs. Funded by the Natural Sciences and Engineering Research Council of Canada.Grant Funding SourceNSERC
Myocardin‐ related transcription factor A regulates myofibroblast formation and function
Authors: Crider Beverly Joy , Green Michael S. , Broiles JoSette L. , Howard Eric W. , Haaksma Carol J. , Tomasek James J. 
Published: June 2021

Myofibroblasts (MFs) differentiate from fibroblasts and function to facilitate wound closure. Under pathological conditions, MFs fail to undergo apoptosis and continue to remodel the extracellular matrix, leading to increased contracture of connective tissue. MFs are characterized as having "super‐mature" focal adhesions and expression of smooth muscle α‐actin (SMAA). Myocardin‐related transcription factors A and B (MRTF‐A/MAL/MKL‐1 and MRTF‐B/MKL‐2) are putative mechanical stress‐induced co‐activators that activate expression of contractile proteins such as SMAA. Small interfering RNA (siRNA) has been used to study the effects of MRTF‐A and MRTF‐B reduction on the MF contractile phenotype in rat embryonic fibroblasts. Decreased SMAA levels, as determined by immunoblot analyses, and reduced contractile force generation, as determined by a wrinkling assay, were observed in cells transfected with MRTF‐A and ‐B‐targeted siRNA. Immunocytochemistry has shown a decrease in the size and number of focal adhesions in these cells when compared to control cells. Finally, transiently transfected myocardin, which acts similarly to constitutively‐active MRTF‐A, increased SMAA promoter activity and increased the contractile ability of cells plated on a deformable wrinkling substrate. These results suggest MRTFs play a critical role in regulating MF formation and function. (Funded by NIH 2R01GM60651)Grant Funding SourceNIH
Dissecting the role of an anatomy teaching assistant
Authors: Jacobs Sarah Marie , Chen Laura P , Camp Christopher L , Gregory Jeremy K , Alexander Cara J , Lachman Nirusha , Pawlina Wojciech 
Published: June 2021

Gross anatomy courses often utilize teaching assistants (TAs) to serve a multifaceted purpose. Qualitative analysis of interviews with gross anatomy TAs reveals seven distinct roles: formal teaching during course lectures, informal teaching during dissection, prosecting a demonstration cadaver, orchestrating regular review sessions, coordinating formative feedback about academic progress and professionalism, tutoring struggling students outside of class time, and supporting students in crisis should the need arise. Analysis also finds that TAs did not anticipate the full scope of their duties prior to undertaking them, and felt particularly unprepared to address issues of student mental health. We report our findings and propose a model for proactively training TAs for their inherently complex role. This work was supported by the Mayo Clinic Department of Anatomy.Grant Funding SourceStudent/Postdoctoral Travel Award Student Award
Using Tablet PCs and DyKnow Vision to Enhance Student Engagement in a Human Anatomy Class
Authors: Lafontant Pascal J 
Published: June 2021

Keeping students engaged in human anatomy classes is a significant challenge. To increase students' active learning and facilitate understanding of material, Tablet PCs running the software DyKnow Vision were introduced in a human anatomy class. Tablet PCs and DyKnow Vision were specifically used to create a virtual blackboard for the identification and discussion of anatomical structures. Anatomical illustrations from the primary text used in the class were routinely imported and saved as DyKnow Vision files. Students were then provided with DyKnow panels of unlabeled structures to identify and label using digital ink. The labeled panels were submitted, reviewed, corrected with the class' participation, and appended to the class session. To assess students' level of engagement, their attitudes and perceptions of the effectiveness of the Tablet PCs/DyKnow as a pedagogical tool, an anonymous survey using a 5 point Likert scale was completed by students. Results strongly suggest that the Tablet PCs/DyKnow combination made the class enjoyable, enhanced students' comprehension of content, and had an overall positive impact on their learning of human anatomy.Funding: DePauw University
DETERMINANTS OF THE ACTIVITY OF THE MAMMALIAN ANTIOXIDANT SELENOPROTEIN PLASMA GLUTATHIONE PEROXIDASE (GPx‐3)
Authors: Ottaviano Filomena Gabriella , Tang Shiow‐Shih , Handy Diane E. , Loscalzo Joseph 
Published: June 2021

GPx‐3 scavenges reactive oxygen species in plasma by catalyzing the reduction of hydrogen peroxide and lipid hydroperoxides using glutathione (GSH) as a reducing co‐substrate. We compared the specific activity of wild type (WT) and Sec73Cys mutant recombinant GPx‐3 (rGPx‐3). rGPx‐3 WT, Sec73Cys, and empty vector cDNAs were transfected in Cos7 cells in the presence of sodium selenite. rGPx‐3 protein was isolated by His‐Gravi Trap purification, determined by Western blot under reducing and non‐reducing conditions, and compared to native plasma GPx‐3. GPx‐3 activity was assessed by a chromogenic assay, a redox‐sensitive fluorescence based endpoint assay, and an in‐gel assay. Western blot demonstrated a 28 kDa band under reducing conditions for WT and Sec73Cys rGPx‐3 and an additional ∼112 kDa band under non‐reducing conditions. An ∼2.5‐fold increase in tetramer‐to‐monomer ratio for Sec73Cys rGPx‐3 was observed compared to WT rGPx‐3. Native plasma GPx‐3 resulted in a tetramer‐to‐monomer ratio of 2.5. The enzyme activity of WT rGPx‐3 was ~3‐fold higher than Sec73Cys with GSH (ANOVA, p<0.01) using the chromogenic assay, and ~2‐fold higher with the redox‐sensitive fluorescence based endpoint assay (ANOVA, p<0.005). The in‐gel assay also showed activity. WT rGPx‐3 is more catalytically active than Sec73Cys. Quaternary structure does not seem to influence intrinsic activity.Support: HL61795, HL28178, HL81587
Specific HIV‐1 integrase‐reverse transcriptase interactions as a mechanism for promoting reverse transcription
Authors: Chow Samson A. , Wilkinson Thomas A , Zhang Min , Januszyk Kurt , Phillips Martin L , Le Grice Stuart F. J. , Clubb Robert T 
Published: June 2021

Integrase (IN) from human immunodeficiency virus‐type 1 (HIV‐1) exerts pleiotropic effects in the viral replication cycle, and IN mutations can impair reverse transcription. We showed previously that IN stimulates both the initiation and elongation modes of reverse transcription by increasing the processivity of reverse transcriptase (RT) and suppressing the formation of the pause products. IN and RT interact in vitro, and the IN C‐terminal domain (CTD) is both necessary and sufficient for binding RT. We used nuclear magnetic resonance spectroscopy to identify a putative RT‐binding surface on the IN CTD, and surface plasmon resonance to obtain kinetic parameters and the binding affinity for the IN‐RT interaction. An IN K258A substitution that disrupts reverse transcription in infected cells is located at the putative RT‐binding surface, and we find that this substitution substantially weakens IN CTD‐RT interactions. Other substitutions at the putative RT‐binding surface also rendered the virus replication‐incompetent. These results strengthen the notion that productive IN‐RT interactions are important for efficient reverse transcription during HIV‐1 replication, and provide insights into this interaction at the molecular level.This research is supported by NIH R21 AI077386.
Testing the Shifting Specificity Model for Enzyme Catalysis
Authors: Britt Billy Mark 
Published: June 2021

The Shifting Specificity model (SSM) for enzyme catalysis explains enzyme catalysis generally and addresses the deficiencies in the Haldane‐Pauling‐Koshland model (HPKM) of enzyme catalysis. The tenets of the SSM are outlined and the results of experiments to test the validity of each model are presented.Strong ground state/enzyme interactions are positively correlated with catalytic efficiency. Larger enzymes are better catalysts than smaller enzymes. These data are explained by the SSM which calls for a direct role for the entire enzyme molecule in the catalytic event. The HPKM has no such role and maintains that weak ground state interactions are favorable for catalysis.Many enzymes have two folded conformations. For bovine adenosine deaminase, the low‐temperature (< 30ºC) conformation appears to be better optimized for interaction with the reaction transition state than does the physiological conformation. The SSM requires two global conformations of the enzyme unlike the HPKM which requires only one.It is argued that the SSM better explains the data than does the HPKM.