bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical anatomy of the male pelvis: a 3D model based on the Visible Human Project®
Authors: Sanchez Jaime E , Krieger Beth R , Marcet Jorge E , Decker Summer J , Ford Jonathan M , Hilbelink Don R
Published: June 2021

Surgical anatomy of the pelvis remains a complex and often controversial topic. Operating in the pelvis can be difficult due to poor visualization, limited maneuverability, and ill‐defined surgical anatomy. However, proper identification and preservation of pelvic autonomic nerves in surgery is associated with decreased morbidity including reduced urinary and sexual dysfunction.

The objective of this study was to construct an accurate 3D computer model of the surgical anatomy of the male pelvis, with particular focus on fascias and the autonomic nervous system.

The model was created by meticulous segmentation of the Visible Human Project® male data set and enhanced with findings obtained from cadaveric dissections and pelvic operations. Specific attention was paid to identification of fascial planes and the course of autonomic nerves. The model was rendered in the 3D visualization software packages, Mimics v. 12, OsiriX v. 3, and 3ds Max 9. It was then compared to cadaveric dissections and operative findings for accuracy.

We conclude that it is possible to minimize autonomic morbidity in the pelvis by proper identification of fascial planes and have constructed an enhanced 3D model of the male pelvis based on the Visible Human Project®. This model serves to improve anatomic understanding for surgeons and provides the most detailed 3D rendering of an actual human pelvis for further study.

Grant Funding Source

None
Teaching pharmacology in a clinical presentation curricular model
Authors: McMahon Kathryn K. , Quest Dale
Published: June 2021

The objectives is to evaluate the ability to introduce basic medical pharmacology to medical students in their first two years of medical education by integrating that content in the curricular strategy of a Clinical Presentation model. This curricular strategy introduces all basic science content from the beginning of the medical education experience in the context of a series of clinical presentations or chief complaints (e.g. Sore Throat or Dyspnea). Pharmacology is being introduced by variety of teaching methods including use of a prototype formulary, unveiling those drugs using a Drug of the Day e‐mail notification system to highlight a new drug in the context of the Clinical Presentation being covered, evaluating pharmacokinetics and pharmacodynamics using full body adult and pediatric simulators and traditional classroom teaching methods (team based learning, small group discussions, interactive didactic). The evaluation of this method of introducing pharmacology will be done by collecting informal feedback from students (e.g. e‐mail correspondence), audience response system question/answer data from within interactive didactic sessions, formative and summative exam results on pharmacology‐related items, and qualitative data (e.g. focus group feedback) and to the extent possible students scoring on pharmacologically related questions on the National Board of Medical Examiners Comprehensive Basic Science Exam and US Medical Licensing Examination Step 1 . This project will begin as the first class of the Paul L. Foster School of Medicine begins in July 2009 and the project will continue for a minimum of 3 years (as the first two classes progress through the clinical presentation curriculum of their first two years of medical education).
Maintenance and repair of the pancreas of the adult rat by primitive stem cells
Authors: Fenley J L , Fenley C L , Jones M , Glow J , Long G F , Collins J A , Hixson D , Bowyer F P , Black A C , Young H E
Published: June 2021

Stage‐specific antigen‐4 (SSEA‐4) positive stem cells and carcinoembryonic antigen‐cell adhesion molecule‐1 (CEA‐CAM‐1) positive stem cells have been isolated from the skeletal muscle of adult mammals, including humans. The current study was undertaken to determine the location of these cells within the pancreas of the adult rat. Adult rats were euthanized following the guidelines of Mercer University's IACUC. The pancreases were fixed, cryosectioned and stained with two antibodies diagnostic for adult pluripotential stem cells, i.e. SSEA‐4 for pluripotent stem cells and CEA‐CAM‐1 for totipotent stem cells. Populations of both stem cells were located in tissues of the pancreas based on apparent repair processes. Heavy infiltrations of SSEA‐4 positive stem cells and CEA‐CAM‐1 positive stem cells were located among both pancreatic acinar cells of the exocrine pancreas and islet cells of the endocrine pancreas apparently undergoing repair, whereas other areas of the same pancreases were void of either stem cell population. Studies are ongoing to address the functional significance of these populations of primitive stem cells in pancreatic injury and repair.
Mechanical and chemical activation of muscle satellite cells is perturbed in normal aged mice
Authors: Leiter Jeff , Anderson Judy
Published: June 2021

Age‐related muscle atrophy and the importance of satellite cells in muscle maintenance, growth and repair led us to examine the effects of mechanical stretch, nitric oxide (NO), and age on satellite cell (SC) activation and gene expression in normal young and old mice. Baseline variables (body mass, muscle mass, fiber cross‐sectional area (CSA), muscle strength, SC population, stretch activation and gene expression) were obtained from normal C57/BL6 mice at 3, 6, 8, 12 and 18 months‐of‐age. Activation was assayed by 3H‐thymidine incorporation into extensor digitorum longus (EDL) muscles isolated for culture with (S) or without stretching (US). In a second experiment, muscle from 8‐ and 18‐month old mice was treated with one or more of: stretch, L‐Arginine (LA); NO‐donors (isosorbide dinitrate (ISDN) and MyoNovin (MN) a new formulation); Nω‐nitro‐L‐Arginine methyl ester (LN). EDL muscles from 6‐month‐old mice required a greater stretch stimulus (20% vs. 10% length increase) than EDL from younger mice to increase SC activation. Stretch did not increase SC activation in mice older than 6 months‐of‐age. NO from either endogenous (LA) or exogenous (ISDN, MN) NO donors increased SC activation by stretch in 8‐ but not 18‐mo‐old EDLs. Perturbed sensitivity to mechanical stimulation and NO in 18‐mo‐old mice may partly explain loss of muscle mass, fiber CSA, relative grip strength and SC pool size with age. Similar to dystrophic muscle, a disrupted dystrophin‐glycoprotein complex and subsequent alteration in NO availability may affect the ability of native satellite cells to maintain or effectively regenerate aged muscle.

Grant Funding Source

Canadian Space Agency Life Sciences
Repair of traumatic skeletal muscle injury with bone marrow derived cells seeded on extracellular matrix
Authors: Merritt Edward K , Le Long N , Gokhale Rohit A , Walters Thomas J , Farrar Roger P
Published: June 2021

Surgical repair of a skeletal muscle injury resulting in tissue loss poses unique challenges to the surgeon. Despite the regenerative potential of skeletal muscle, if a significant amount of tissue is lost, skeletal muscle fibers will not grow to fill the injured area completely. Prior work in our lab has shown the potential to fill the void with an extracellular matrix scaffold (ECM), but functional recovery is limited. To improve the functional outcome of the injured muscle, a muscle‐derived ECM seeded with bone marrow derived cells was implanted into a 1 x 1 cm2 defect in the lateral gastrocnemius (LGAS) of Lewis rats. Without the addition of cells, the ECM repaired LGAS produced 76.4 ± 2.4% of the maximal force of the contralateral LGAS after 42 days of recovery. The LGAS repaired with ECM and cells produced 85.0 ± 4.2% of the contralateral LGAS. The specific tension was 87% and 94% of the contralateral limb for the ECM and ECM with cells groups respectively. The implanted ECM with cells had more blood vessels than the ECM without cells (p < 0.05). The data suggest that the repair of a skeletal muscle defect injury by the implantation of a muscle‐derived ECM seeded with bone‐marrow derived cells can improve the functional outcome after 42 days. This is likely due to an increase in blood vessels and skeletal muscle fibers growing inside the implanted ECM. This work funded in part by the U.S. Army MRMC grant DAMD W81XWH‐06‐1‐0540.
Manipulating the microenvironment for vascular differentiation and regeneration
Authors: Gerecht Sharon
Published: June 2021

Microvasculature differentiation and regeneration is guided by both biochemical and biophysical cues. Human embryonic stem cells (hESCs) and adult endothelial progenitor cells (hEPCs), which are capabile to differentiate and form blood vessels de novo, can be used as a model system to elucidate vasculogenic and angiogenic mechanisms and explore central issues in vascular regeneration. Our goal is to understand the molecular mechanisms underlying human vascular differentiation and regeneration. To achieve this we exploit microengineering approaches to manipulate, study, and direct adult and embryonic stem cell differentiation. As an example, we found that the extracellular matrix polysaccharide hyaluronic acid (HA) is a developmentally relevant material for the growth of hESCs. Human ESCs encapsulated in HA hydrogels maintained undifferentiated and induced to initiate vasculogenesis by supplementation with VEGF. In continues studies, utilizing mechanically tunable HA hydrogels, we show that VEGF and matrix stiffness regulate angiogenesis from hEPCs. For the binding interactions between cells and surfaces, it has become increasingly evident that cells are influenced also by spatial domains, structural compositions, and mechanical forces at the microscale and nanoscale. We discovered that micro‐nanotopography of a substrate can be used to control vascular assembly and tubulogenesis.
Mechanoregulated expression of smooth muscle alpha‐actin in myofibroblasts is mediated by actin dynamics and myocardin related transcription factor‐A localization
Authors: Broiles JoSette LB , Hinz Boris , Wipff Pierre‐Jean , Howard Eric W , Haaksma Carol J , Tomasek James J
Published: June 2021

Myofibroblasts are specialized fibroblasts that facilitate wound closure through expression of smooth muscle (SM) contractile proteins and generation of contractile force on the surrounding matrix. We hypothesize mechanoregulation of SM α‐actin (SMAA) expression in myofibroblasts is mediated by actin dynamics regulating localization of myocardin related transcription factor‐A (MRTF‐A); on compliant substrata, high levels of G‐actin will sequester MRTF‐A, while on stiff substrata decreased G‐actin levels will release MRTF‐A to interact with the SMAA promoter. Rat embryonic fibroblasts cultured on novel deformable substrata of varying stiffness were analyzed. Increasing substratum stiffness resulted in a graded increase in SMAA promoter activity and endogenous mRNA expression, focal adhesion and stress fiber assembly, and MRTF‐A nuclear localization, suggesting that the lack of a critical stiffness acts as a switch. The actin polymerizing agents, jasplakinolide and cytochalasin D, promoted nuclear localization of MRTF‐A and increased SMAA expression, independent of substratum stiffness. Similarly, a constitutively nuclear MRTF‐A promoted SMAA expression independent of substratum stiffness. This work demonstrates that actin dynamics, in response to the mechanical environment, regulate nuclear localization of MRTF‐A and thereby expression of SMAA. Funded by NIH grant R01 GM60651.

Grant Funding Source

NIH grant R01 GM60651
Dermacentor variabilis: Regulation of Macrophage Migration and Phagocytosis by Tick Saliva
Authors: Kramer Carolyn D , Poole Nina M , Coons Lewis B , Cole Judith A
Published: June 2021

We studied the effects of tick saliva and salivary gland extract (SGX) on cell migration, cell signaling, and phagocytosis in the murine macrophage cell line, IC‐21. Saliva increased both basal and platelet‐derived growth factor (PDGF)‐stimulated macrophage migration. However, saliva did not affect PDGF‐stimulated extracellular signal‐regulated kinase (ERK) or AKT (protein kinase B) activity. Saliva also had no affect on phorbol‐12‐myristate‐13‐acetate (PMA)‐stimulated AKT activity. Lipopolysaccharide (LPS)‐stimulated Interleukin 1 receptor‐associated kinase (IRAK) activity was unaffected by SGX, while zymosan‐mediated IRAK activity increased when cells were pretreated with saliva. Saliva suppressed phagocytosis of zymosan particles by macrophages. These results suggest that Dermacentor variabilis has evolved a mechanism for selectively controlling the host's wound healing response.
The role of heme oxygenase in wound healing
Authors: Nicholson Susannah E , Johnson Fruzsina K , Stewart Ronald M , Johnson Robert A
Published: June 2021

Damaged tissues express heat shock proteins. One such protein, heme oxygenase (HO‐1), catalyzes conversion of heme to liberate iron, biliverdin and carbon monoxide (CO). Evidence suggests that heme and the HO products iron, biliverdin and CO may adversely impact tissue growth. Accordingly, we wanted to determine the effects of HO activity on wound healing in rats. Rats were treated with 20 µmol/kg IP daily of heme‐L‐lysinate, iron or biliverdin and received full thickness abdominal incisions, which were then sutured. Controls received a laparotomy only. An additional group received matched administration of exogenous CO. To evaluate HO activity, whole animal CO excretion was measured using solid‐phase gas chromatography. The thickness of the wound tissue and the tearing force were measured 14 days after the incisions. Tensile strength and the normalized breaking strength were calculated to evaluate wound strength. CO excretion was increased by 60% in animals treated with heme as compared to controls. Normalized breaking strength was decreased by heme, iron, and biliverdin, but tensile strength was unchanged. The effects can be attributed to a decrease in tissue thickness. In contrast, CO increased both normalized breaking strength and tensile strength but did not change the tissue thickness. These findings suggest that the release of iron and biliverdin during heme degradation may adversely impact tissue growth whereas the release of CO may help to stabilize against the effects of the other HO products.

Supported by NIH/DOD grant HL64577.
HYPOXIA PROMOTES WOUND HEALING THROUGH SELECTIVE REGULATION OF INTEGRIN β1 BY HYPOXIA‐INDUCIBLE FACTOR (HIF)
Authors: Keely Simon , Glover Louise E , MacManus Christopher F , Campbell Eric L , Furuta Glenn T , Colgan Sean P
Published: June 2021

Due to localized vascular damage and increased oxygen demand, wound healing occurs in a relatively hypoxic setting. This is particularly relevant to wound healing in chronic inflammatory conditions such as Crohn's disease and ulcerative colitis. Here, we sought to identify the role of hypoxia (Hx) in mechanisms of wound repair in a model of the intestinal submucosa. Initial studies revealed that Hx promotes wound healing, as modeled by an increase in intestinal fibroblast‐mediated collagen gel contraction. Guided by results from transcriptional profiling, we identified the selective induction of fibroblast integrin β1 (ITGB1) by Hx. Further analysis revealed that both Hx and pharmacological activators of hypoxia‐inducible factor (HIF), induce fibroblast β1 integrin mRNA, protein and function by as much as 4‐fold. Cloning of the β1 integrin gene promoter revealed a 10±0.8‐fold increase in promoter activity in response to Hx. Subsequent studies identified functional DNA binding to HIF in the ITGB1 gene. Mutational analysis of the HIF binding site within the ITGB1 promoter resulted in a loss of ITGB1 hypoxia‐inducibility. In vivo murine studies revealed a correlation between colitic disease severity and tissue ITGB1 expression (R2 = 0.80). Combined, these results demonstrate that Hx induces fibroblast ITGB1 expression and function by transcriptional mechanisms dependent on HIF.

Grant Funding Source

NIH
Development of S100B knockout embryos following inhibition of S100A1 protein expression
Authors: Chan Wood Yee , Cheung Siu Yuen , Heizmann Claus W.
Published: June 2021

S100A1 and S100B, members of the EF‐hand family of Ca2+‐binding proteins, exist in cells as homo‐ or hetero‐dimers. Our studies on mouse embryos showed that these two proteins shared some common expression sites including skeletal tissues, dorsal root ganglia, trigeminal ganglia and the hindbrain. However, neither S100A1 nor S100B knockout mice exhibit overt structural abnormalities. In the present study, we had examined the development of mouse embryos in which expression of both proteins was inhibited. Small interfering RNAs targeting specific sequences of S100A1 mRNA were microinjected into S100B knockout embryos in utero at E13.5 when S100A1 protein had just started its expression. Two days after microinjection, S100A1 expression was examined by reverse transcription‐PCR and immunohistochemical localization and structural changes determined after serial sectioning. A decrease of S100A1 expression and absence of S100B protein were observed, but no morphological anomalies were found in S100B knockout embryos with a reduction of S100A1 expression. Our observations support the notion that both S100A1 and S100B proteins are not indispensible for embryonic development.

The work was supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project no. CUHK4421/05M) and a Direct Grant from the Faculty of Medicine, CUHK (Project Ref 2007.1.006, ID 2041322).
Lmx1b Modulates Extracellular Matrix Expression During Limb Dorsalization
Authors: Feenstra Jennifer Marie , Kanaya Kohei , Pira Charmaine U , Oberg Kerby C
Published: June 2021

.

Lmx1b is a homeodomain transcription factor that is known to regulate dorsal limb identity and Lmx1b knockout (KO) mice develop nearly symmetrical ventral‐ventral limbs. Currently, downstream limb‐specific targets of Lmx1b are poorly defined.

To identify and characterize potential limb‐specific genes targeted by Lmx1b, we compared gene arrays from Lmx1b KO and wild type (WT) mouse limbs harvested during limb outgrowth and patterning, i.e., 11.5, 12.5, and 13.5 days post coitum (dpc). Gene expression was analyzed using replicate Affymetrix 430 2.0 mouse genome arrays. Real‐time PCR confirmed microarray results and whole mount in situ hybridization localized gene expression.

Genes that were differentially expressed throughout this period of limb development included 46 significantly up‐regulated and 10 down‐regulated genes. Lmx1b up‐regulated several genes linked to tendon and bone formation including: Emx2 (a homeodomain transcription factor), several extracellular matrix (ECM) proteoglycans (Kera, Lum, Acan) and two Matrilins (Matn1, Matn4). Real‐time PCR confirmed differential expression and whole mount in situ hybridization localized expression to the dorsal tendon primordia.

These data suggest that Emx2 and a unique collection of ECM‐associated factors orchestrate Lmx1b‐regulated dorsalization by altering the environment in which tendon formation and/or attachment occur.

Grant Funding Source

NICHD ‐ HD39421
Rescuing craniofacial development in an avian model of holoprosencephaly
Authors: Chong H. Jonathan , Marcucio Ralph
Published: June 2021

Blockade of Sonic hedgehog (Shh) signaling in the embryonic forebrain leads to altered gene expression in the facial ectoderm and morphologic changes resembling holoprosencephaly. However, the molecular pathways that are involved in communications between the forebrain and facial ectoderm are not known. The aim of this study was to test the ability of candidate pathways to restore ectodermal gene expression and craniofacial morphology following blockade of forebrain Shh signaling. Activation of the Bone Morphogenetic Protein‐2 (BMP‐2) pathway in the head mesenchyme of treated embryos did not rescue morphology and created severe phenotypes. In contrast, preliminary results suggest that activation of the Shh pathway leads to partial morphologic rescue. Ongoing studies are examining changes in gene expression patterns in the ectoderm covering the upper jaw anlagen. These data suggest that exogenous Shh signaling, but not BMP‐2 signaling, restores forebrain‐ectodermal communications and will help elucidate the normal signaling mechanisms between these tissues.

Grant Funding Source

NIH/NIDCR R01DE018234 to R.M. and HHMI Medical Research Training Fellowship to H.J.C.
Understanding the anatomical priorities of the field of Obstetrics and Gynecology
Authors: Zumwalt Ann
Published: June 2021

Given the reduced number of hours allotted to basic science medical education, educators must prioritize the topics we emphasize in our lessons. In order to maximize long‐term retention of information, it is useful to understand how our students will encounter our subjects in their later careers. Female pelvic anatomy is a notoriously difficult topic in gross anatomy, and Obstetrics & Gynecology (ObGyn) clinicians rely heavily on having a strong conceptual understanding of anatomy. In this study, ObGyn attending physicians were asked to rank the clinical importance of a wide range of topics in female pelvic anatomy on a Likert scale of 1‐10 (unimportant to essential). These were categorized as perineum, vagina/cervix, uterus/adnexa, urinary system, gastrointestinal system, pelvic floor, peritoneal spaces and blood supply topics. Three topics were consistently rated most important: the layers of the uterus, the locations of the ureters relative to other structures, and the branches of the internal iliac artery. Lymphatic drainage of all structures was consistently ranked as a low priority (note however that no ObGyn oncologists were surveyed). When asked to prioritize what they would like medical students to understand before they start their clinical service, most attendings emphasized the relative positions of pelvic structures, blood supply to the pelvic structures, and the pelvic floor.
Humanities in gross anatomy project: a humanistic learning tool
Authors: Canby Craig A. , Bush Traci
Published: June 2021

Gross anatomy affords physical therapy students an opportunity to discover human morphology through intimacy with the dead. Moreover, it also socializes future physical therapists to the humanistic aspects of the profession. In 2007, faculty decided to socialize students to the humanities with a new course requirement: Humanities in Gross Anatomy Project (HuGA) Project. At the end of the course, students submitted a project that described how the student had been personally touched by the donor's gift and how the gift contributed to their professional growth and education. The submission could be a narrative, poem, song, video, etc. All students performed admirably; thus taking the first step in socializing themselves to their professional education. The overall success of the HuGA Project may be exemplified by these excerpts from a submitted poem as a tribute to a great teacher ‐ the donor:

"But this lifeless body, told stories to us

Through arteries, veins, and the things that we touched

She taught me respect, and I learned what it means

To work with integrity, to work professionally

Her gift truly selfless, her choice such a gift"

Providing students with humanistic learning opportunities early within the curriculum, facilitated reflective learning. The utilization of reflection as it relates to clinical decision making and client interaction is critical for physical therapy practice.
Comparing attitudes towards teamskills using the Objective Structured Behavioural Exam (OSBE)
Authors: Keane Aisling , McCullough Stephen , Wilson David
Published: June 2021

Communication failure between healthcare professionals is a leading cause of inadvertent patient harm. The OSBE is a new methodology to test synergy within a team using a subject based approach; however it may also be used to compare attitudes towards teamskills between different student populations. Undergraduate medical (n = 271) and nursing students (n = 158) were organised into groups and asked to work as a team to solve similar histology related tasks in a given amount of time. Questionnaires were given before and after the task and the answers were compared between the two groups. Both medical (40.8%) and nursing students (39%) felt they lacked confidence to speak their minds. Additionally, both medical (23.5%) and nursing (25%) students regard organisational skills as a key factor to the success of the team. However, the cohorts differed when they were asked which quality they would most like to improve upon. Medical students (35%) regarded active listening as one of the key areas they would like to develop, whereas nursing students (25%) considered that organisational skills and focus was of more importance. Both medical (91%) and nursing students (96%) stated that they felt the exercise was extremely beneficial because it helped them identify areas of their teamskills that they needed to work on.
How anatomy is taught to dental students: Results of an ADEA survey to US and Canadian faculty
Authors: Lambert H. Wayne , Atsas Stavros , Gould Douglas J. , Hutchins Robert J , Burk Dorothy T
Published: June 2021

Members of the Anatomical Sciences Section of the American Dental Education Association (ADEA) recently completed an international survey of the directors of all North American dental gross anatomy courses to assess: 1) what level of detail are specific topics and content areas being presented; 2) when in the curriculum are specific content areas are taught; 3) what areas are omitted; and 4) what other areas are of concern with regard to North American dental gross anatomists. The survey received a 95.5% response rate representing 64 (of 67) of the US and Canadian dental schools. The results of this survey indicate, amongst other things that: 1) the use of computer‐assisted instruction (CAI) tools has increased; 2) emphasis on clinical topics has increased; 3) reliance upon medical school faculty and facilities is high; 4) a pattern of increased use of integrated curricula among dental schools has emerged; and 5) a general trend for a decrease in student contact hours is ongoing. The specific data are currently being analyzed and will be presented. These data will provide the framework by which course directors and administrators, in need of curricular information, can make more informed decisions in the appropriateness of content and even provide guidance in evaluation of their program.

Grant Funding Source

AAA Young Faculty Travel Award – Supported by AAA Second Century Fund
The Impact of Wearing Scrubs on Contextual Anatomy Learning
Authors: Finn Gabrielle Maria
Published: June 2021

The impact of contextual learning in anatomy is of interest, as students often learn in one setting (medical school) and apply this in another (practice). Learning in an educational context may not transfer well to practice (clinical) environments.

We explored the impact of an authentic aspect of context (wearing scrubs) on learning and recall, using a cross‐over design.

82 1st year medical students participated.

Students completed a gross anatomy and kidney imaging pre‐test in their own clothes, to establish if they had prior knowledge.

Students, divided into groups, wore either scrubs or their own clothes for the teaching session on the gross anatomy of the kidney. A gross anatomy specific mid‐test was then completed immediately after the teaching session.

Next students changed into the opposite clothing and attended a self‐directed kidney imaging session. An imaging specific mid‐test was then completed. 4 weeks after teaching students completed 2 post‐tests in their own clothes, a gross anatomy and an imaging test.

Data analysis was performed using a paired t‐test, p<0.05 was considered statistically significant. Results show a significant difference between groups; p=0.04. The intervention's effect size was calculated as 0.27, a 'moderate' effect in teaching terms. Students examined in the same context as they were taught in recalled significantly more information.

Research supported internally.

Grant Funding Source

Durham University
A computer‐assisted instructional tool for gross neuroanatomy
Authors: Lynn Lorinda Kay , Foreman K. Bo
Published: June 2021

Unstained serial brain sections are a major teaching resource in the gross neuroanatomy laboratory. However, outside of the teaching laboratory, students typically rely on atlases that feature stained sections, drawings and clinical scans. To provide students with the most relevant study materials outside of lab, we developed a computer assisted instructional (CAI) tool featuring unstained brain dissections and serial sections. Our objective was to determine if this CAI tool is a beneficial adjunct to neuroanatomy lab. Embalmed human brains were dissected or frozen and sectioned. The prepared brains were photographed, labeled using Macromedia Fireworks, and inserted in a web application developed using Macromedia Flash. Sixty‐nine physical and occupational therapy students had access to this tool while enrolled in a neuroanatomy course. Students were given a questionnaire and the data were analyzed using descriptive statistics. On a scale of 1 (strongly disagree) to 10 (strongly agree), students rated the CAI tool as beneficial to learning (mean 9.1±0.7), said it provided education on structure identification (mean 8.3±1.5), found it easy to navigate (mean 9.0±1.0), and preferred it to similar pictures in atlases (mean 8.0±1.5). We conclude that this CAI tool is a beneficial adjunct to neuroanatomy lab. The information gained from this study will be used to guide further development of this tool.

Grant Funding Source

N/A
Creating online Histology study tools for Medical/Dental students at the University of British Columbia (UBC)
Authors: Korj Oxana , Lin Cheng , Pinder Karen , Ovalle William K. , Walters Rebecca , Yule Heather
Published: June 2021

Histology is a core preclinical program at UBC Medical and Dental School. In conjunction with lectures and laboratories, a significant portion of student learning is through online resources such as weekly practice quizzes. We aimed to create new quizzes in Term Two of the first year Histology curriculum.In order to makequizzes more representative of questions encountered in summative assessments and in clinical situations, we animated virtual slides to simulate microscopic viewing. The movable virtual slides were created by compiling snapshots of tissue sections at increasing magnifications into a "gif" file using Adobe Photoshop. To producean online version of the quiz, questions were formatted using Respondus® software and uploaded to WebCT.WebCT allows easy access to online quizzes and instant feedback for students. In May 2009, we will survey the Medical/Dental Class of 2011 and compare student satisfaction with quizzes from Term One and Term Two. This project was supported by Summer Studentships from the Department of Cellular and Physiological Sciences at UBC.

Grant Funding Source

AAA
The role of 3D printing in teaching and education in human skeletal anatomy
Authors: Carter Yasmin , Allard Travis T , Moore N Collin , Goertzen Andrew L , Klonisch Thomas , Hoppa Robert D
Published: June 2021

The project represents a partnership between physical anthropology and human anatomy for the creation of 3D anatomical models for research and training. The models were created from post‐mortem X‐Ray CT scans of teaching cadavers. Initial steps involved identifying tissues, structures or regions of interest, and segmenting the structures of interest. Once a 3D model was rendered, further editing and refinement was required for 3D printing. CT scans were undertaken at the Health Sciences Centre, University of Manitoba. Analysis of the data was undertaken in the Bioanthropology Digital Image Analysis Laboratory (BDIAL), University of Manitoba. The data were edited and rendered using Materialise MIMICS and INUS Rapidform software. Physical models were created using a Z‐Corp Z406 3D printer. Preliminary input from students demonstrates the impact of the models for training and research, particularly the hand‐on nature of viewing models. Of particular benefit is the ability to reveal hidden structures at increased magnification, facilitating better understanding of the anatomical relationship of structures not easily visible in cadavers or photos. The use of 3D printing provides an innovative, on‐demand, pedagogical tool benefiting a variety of training needs, including physical anthropology, clinical and basic medical sciences. Funded by University of Manitoba; Canada Research Chairs Program.
Multiple functions of the Drosophila Orc6 protein
Authors: Chesnokov Igor , Balasov Maxim , Huijbregts Richard , Svitin Anton
Published: June 2021

The Origin recognition complex (ORC) is important for the DNA replication in eukaryotic cells. ORC is also involved in other cell functions. The smallest Drosophila ORC subunit, Orc6, consists of two functional domains. Larger N‐terminal domain directly involved in DNA binding and is important for ORC‐dependent DNA replication. Smaller C‐terminal domain is important for cytokinesis.

Deletion of Orc6 gene was created in Drosophila. Mutant lethal alleles of Orc6 are defective in both DNA replication and cell proliferation during larval stages of development. Homozygous Orc6 mutants display disc‐less phenotype and show abnormal chromosome condensation and segregation. Mutant cells arrest in both G1 and mitosis stages of the cell cycle. Orc6 mutation can be rescued to viability by full‐length Orc6 transgene. The expression of a transgene carrying the core replicative N‐terminal domain of the Orc6 protein results a restoration of DNA replication in mutant larval tissues. The mutant cells carrying this transgene do not exhibit G1 arrest but nevertheless accumulate at mitosis.

The cytokinetic function of DmOrc6 is associated with the C‐terminal domain of the protein. Orc6 interacts with the septin protein Pnut, which together with the septins Sep1 and Sep2 forms a septin complex important for cytokinesis. Septin complexes exhibit GTPase activity and can assemble into large filaments. The interaction of Orc6 with the septin complex is dependent on the coiled‐coil domain of Pnut. Furthermore, the binding of Orc6 to Pnut increases the intrinsic GTPase activity of the Drosophila septin complex, while in the absence of GTP it enhances septin complex filament formation.

Together our results suggest an active role for Orc6 in DNA replication and septin complex function. Orc6 might be a part of a control mechanism directing the cytokinesis machinery during the final steps of mitosis.
Evolution of sequence specific molecular recognition in telomere end binding proteins from Sterkiella nova
Authors: Dy Catherine Yang , Horvath Martin P
Published: June 2021

Specificity in molecular recognition is the binding of the correct substrate and exclusion of incorrect though very similar looking substrates. We have examined how Sterkiella nova telomere proteins distinguish cognate versus non‐cognate single stranded DNA sequences using approaches measuring both thermodynamic and kinetic performance. Features from X‐ray crystal structures that correlate strongly with high specificity include Watson‐Crick like H‐bonds between guanine bases and aspartate or glutamate amino acid residues. We further tested the role of these interactions by mutagenesis, and surprisingly, binding affinities measured for single amino acid substitution variants were very similar to those measured for wild type protein. In contrast, our study of kinetic on and off rates of different complexes shows that the rate with which a protein releases substrate DNA is more predictive of specificity performance. In this system, specificity appears to have evolved by optimization of kinetic off rates, and possibly on rates as well, not equilibrium binding constants. These findings likely reflect the reality that specificity operates in a dynamic and responsive (i.e. living) system. C.Y.D. (University of Utah Graduate Research Fellow), M.P.H. (NIH R01 GM067994).
The 19S proteasome positively regulates the chromatin structure of cytokine inducible genes
Authors: Koues Olivia I , Dudley Robert Kyle , Greer Susanna F
Published: June 2021

Recent studies have indicated that the 19S proteasome's function extends beyond that of a role in protein degradation to an important role in the regulation of transcription. Research in yeast shows that 19S ATPases associate with active promoters and recruit the histone modifying SAGA complex. Also, components of the 19S proteasome are known to directly link histone activating events including histone H2B ubiquitination and histone H3 methylation. Although 19S ATPases facilitate these and other chromatin remodeling events in yeast, it was less clear until recently if they play similar roles in mammalian cells. We have shown that 19S ATPases positively regulate histone acetylation at mammalian inflammatory genes. Here we further characterize the role the 19S proteasome plays in regulating and coordinating additional activating histone modifications, including enzyme recruitment and histone methylation and ubiquitination. Our current study emphasizes the importance of the 19S proteasome in modifying histones to initiate transcription of cytokine inducible genes and provides novel insights into the regulation of mammalian transcription. Research supported by grants from the American Cancer Society, the Georgia Cancer Coalition, the Georgia Research Alliance, and Georgia State University.
Functional Analysis of the MacroH2A Histone Variant During Zebrafish (Danio rerio) Development
Authors: Guajardo Laura ines , Muñoz Valentina , Bouvet Philippe , Molina Alfredo , Alvarez Marco
Published: June 2021

In the nucleus, DNA is associated to different proteins, forming a highly dynamic nucleoprotein complex termed chromatin. Assembly of DNA into nucleosomes causes a massive repression of transcription, which can be reversed by different epigenetic mechanisms, such as post‐translational modification of histones and incorporation of histone variants. The variant of the canonical histone H2A, macroH2A (mH2A), possesses a large non‐DNA binding C‐terminal domain termed "non‐histone region" (NHR), which is thought to inhibit two processes that are essential for chromatin activation, histone acetylation and nucleosome remodeling.

In order to study the role of mH2A in epigenetic control of cell differentiation during zebrafish development, we analyzed the expression pattern of the mH2A2 isoform during early embryogenesis and larval stages, at 0, 6, 12, 16, 24, 48 and 72 hours post‐fertilization (hpf). Our results revealed that mH2A2 displays maternal inheritance (0 hpf) and its transcript is expressed in all stages analyzed. Additionally, knock‐down experiments were carried out using morpholino oligonucleotides designed to block translation initiation (mH2A2MOATG) or splicing of the primary transcript (mH2A2MOSS). Both oligonucleotides generated a phenotype characterized by diminished development of anterior structures (head, eyes), somite malformation and lethality beyond 30hpf. Our results suggest that this histone variant could play a fundamental role in zebrafish development.

MIFAB P04‐071‐F, Fondecyt 1070358, ECOS‐CONICYT C06B03.
Role of melatonin as essential factor of growth and proliferation in SCN cells
Authors: Hong Yonggeun , Lee Sang‐kil , Lee Youngjeon , Kim Joo‐heon
Published: June 2021

This study was investigated to explore the effects of melatonin(N‐acetyl‐5‐methoxytryptamine) on cell proliferation and growth of SCN(suprachiasmatic nucleus) cells. The cells were cultured under 1% FBS, then treated various concentration of melatonin(10 nM, 100 nM, 1 uM, 10 uM) at indicated time points during 48 hr. Higher concentrations of melatonin(10 uM, and 1 uM) considerably inhibited the cell growth. We also found that melatonin at high concentrations(10 uM) suppressed SCN proliferation but not at low concentrations(10 nM). The cell numbers were significantly increased at 10 nM melatonin treatment(P<0.01). Furthermore, using FACS, melatonin treated cells were analyzed cell cycle, showing significantly increased the G1 phase(P<0.05) but showing decrease of S phase(P<0.05). These results indicate that melatonin induced cell proliferation and growth of SCN cells, and which was maximized at 10 nM of melatonin treated.

Supported by BioGreen 21 Program(#20070401034006) from Rural development Administration, South Korea
Role of large subunit ribosomal protein L4 in ribosome maturation and cell cycle progression in Saccharomyces cerevisiae
Authors: Bommakanti Ananth S , Lindahl Lasse , Zengel Janice M
Published: June 2021

Eukaryotic ribosome biogenesis is a highly co‐coordinated multi‐step process that requires equimolar synthesis of several rRNAs and over 50 ribosomal proteins. Until recently, ribosomal proteins were mainly considered only as structural components of the ribosomes. This view has now changed with increasing evidence indicating consistent alterations in r‐protein expression levels during tumorogenesis and in certain developmental defects.

Ribosomal protein L4 is a large ribosomal subunit protein that is structurally conserved in all kingdoms of life. Furthermore, there are several reports of alteration in regulation of L4 mRNA during tissue regeneration, interaction of L4 with transcriptional factors, and varied regulation of L4 mRNA in cancer cell lines. This indicates that L4 has key extra ribosomal functions along with its role in ribosomal biogenesis and function. Here we show that in vivo depletion of Rpl4p in S. cerevisiae results in severe loss of 60S ribosomal subunits. Northern blot, primer extension, and uracil pulse‐labeling experiments suggest this might be due to a block in the processing of the 27SA3 precursor RNA into 5.8S and 25S rRNA as well as a delay in processing of 35S precursor indicating an important role in maturation of the large subunit of the ribosome. More surprisingly, depletion of Rpl4 and select few large subunit ribosomal proteins results in accumulation of multiple budded phenotype. FACS analysis further confirms accumulation of 3N peak representing the multi budded phenotype. Initial microscopic analysis shows that the Rpl4p depleted cells might be getting arrested in late anaphase / early telophase with separated nuclei but disorganized micro tubules. Further experiments are being done to characterize this phenotype and to elucidate the role of Rpl4 in this particular cell cycle defect
Cyclin dependent kinase 5 (CDK5): a possible link between neuropathologies and diabetes
Authors: Stevens Jessica , Aguanno Ann
Published: June 2021

We study the role of CDK5 in mammalian development. Although a member of the cyclin dependent kinase family, CDK5 has been shown to influence differentiation of non‐dividing nervous tissues. Previously, our lab has used PC12 cells to study CDK5's role in neuronal development. Experiments involving growth factor‐induced (NGF, FGF) differentiation of PC12 cells in the presence of CDK5 inhibitors resulted in drastic morphological changes. Recent reports suggest CDK5 may also play an extra neuronal role. Here we report the impact of CDK5 manipulation in pancreatic tissue using the acinar cell line AR42J. The transdiffereniation of these cells from non‐insulin producing (acinar) to insulin producing (beta‐like) cells was induced by the administration of the chemical exendin‐4. Cells were assayed for the insulin phenotype, with a primary rat islet cell line used as a positive control. To asses the role of CDK5 in the pathway to this phenotype, insulin levels were quantified following simultaneous treatment of these cells with both exendin‐4 and the CDK5 specific inhibitor, olomoucine. Results suggest a role for CDK5 in the acquisition of this insulin phenotype. This data, coupled with the neurological role of CDK5, suggests a correlation between pathologies such as Alzheimer's disease and Type 2 Diabetes.
CDKN1C (P57KIP2) NEGATIVELY REGULATES E2F1‐DRIVEN TRANSCRIPTION VIA A DIRECT INTERACTION
Authors: Cress Doug , Wright Gabriela M , Ma Yihong
Published: June 2021

Objective

To determine the mechanism by which CDKN1C binds and transcriptionally represses E2F1‐driven transcription. We previously found that E2F1 can induce transcription of the cyclin‐dependent kinase inhibitor CDKN1C (p57, KIP2). Furthermore, we showed that the CDKN1C protein could in turn repress E2F1‐driven transcription. In the current work, we explore the mechanism by which CDKN1C represses E2F1‐driven transcription. We demonstrate that E2F1 and CDKN1C can form stable complexes both in vivo and in vitro. Molecular studies demonstrate that the E2F1/CDKN1C interaction is mediated by two E2F domains. A central E2F1 region containing the "marked box" domain interacts directly with CDKN1C, whereas a C‐terminal E2F1 domain interacts with CDKN1C via interaction with Rb. Chromatin immunoprecipation assays demonstrate that CDKN1C associates with known E2F1‐regulated promoters in vivo. Overexpression of CDKN1C results in an inhibition of RNA polymerase II C‐terminal domain phosphorylation suggesting a mechanism by which promoter‐associated CDKN1C may inhibit transcription. These results highlight a novel mechanism by which E2F1 transcriptional activity is restrained.
Distal and proximal promoters of rat mitochondrial glycerophosphate acyltransferase gene direct the tissue specific expression of their transcripts
Authors: Guha Prajna , Shilpi Rasheda Y. , Haldar Dipak
Published: June 2021

We have previously shown that rat mtGPAT has two promoters : a regulatory distal promoter which is ~ 30kb upstream of the first translational codon and a constitutive proximal promoter which is 63 bp upstream of the second translational codon. These promoters are responsible for the production of two transcripts with different 5′‐ends. The tissue distribution of the two transcripts and the amount and specific activity of mtGPAT protein were investigated. 5'RACE PCR performed on total RNA isolated from different tissues of rat suggested the presence of alternatively spliced variants of the distal and proximal promoter products. There was presence of three spliced variants of mtGPAT mRNA in liver, kidney and adipose tissues while there was presence of only two variants in skeletal muscle, heart, lung and brain. Western blotting and GPAT specific activity performed on intact mitochondria isolated from the various tissues suggested that both the mtGPAT protein levels and their specific activities were relatively higher in liver, adipose tissues, heart, kidney and were much lower in the other tissues. The results also provide evidence that there is a constant level of the proximal transcript in all the tissues while the amount of the distal transcript varied in a tissue specific manner. Supported by NIH grant GM‐57643.
Mechanistic analysis of Hairy‐mediated long‐range transcriptional repression
Authors: Li Li , Arnosti David
Published: June 2021

Hairy and the related Enhancer of Split family proteins are an important group of transcription repressors, which function in neurogenesis, sex determination, oncogenesis etc. In Drosophila, Hairy is a long‐range repressor, capable of inhibiting distal enhancer elements. Our study focuses on the mechanism of Hairy‐mediated long‐range transcription repression at the chromatin level. Using a transcriptional switch reporter system in Drosophila embryos, work from our lab has shown that, when Hairy binds close to the activators and transcriptional start site, the Groucho corepressor and the histone deacetylase Rpd3 bind and spread throughout the target gene coding region. This indicates that Hairy long‐range repression might happen through a "spreading" mechanism, modifying the chromatin structure over an extensive region to inhibit transcription. In addition, we see that RNA polymerase II occupancy decreases upon Hairy‐mediated repression, contrasting with recent studies that RNA Polymerase II pauses at many silent developmental genes, which suggests there might be an alternative mechanism for developmental gene regulation by active repression. Further study will be focused on the Hairy repression mechanism in the context when Hairy binds distal from the activator and transcription start site.