Medical Anatomy Commons^™

Visualizing Lipid Membrane Structure With Cryo-Em: Past, Present, And Future, Karan D Sharma, Frederick A Heberle, M Neal Waxham

Faculty, Staff and Student Publications

The development of electron cryomicroscopy (cryo-EM) has evolved immensely in the last several decades and is now well-established in the analysis of protein structure both in isolation and in their cellular context. This review focuses on the history and application of cryo-EM to the analysis of membrane architecture. Parallels between the levels of organization of protein structure are useful in organizing the discussion of the unique parameters that influence the collective behavior that influences membrane structure and function. Importantly, the timescales of lipid motion in bilayers with respect to the timescales of sample vitrification is discussed and reveals what types …

Clinical Features And Shared Mechanisms Of Chronic Gastritis And Osteoporosis, Tao Han, Yili Zhang, Baoyu Qi, Ming Chen, Kai Sun, Xiaokuan Qin, Bowen Yang, He Yin, Aili Xu, Xu Wei, Liguo Zhu

Faculty, Staff and Student Publications

Chronic gastritis (CG) and osteoporosis (OP) are common and occult diseases in the elderly and the relationship of these two diseases have been increasingly exposed. We aimed to explore the clinical characteristics and shared mechanisms of CG patients combined with OP. In the cross-sectional study, all participants were selected from BEYOND study. The CG patients were included and classified into two groups, namely OP group and non-OP group. Univariable and multivariable logistic regression methods were used to evaluate the influencing factors. Furthermore, CG and OP-related genes were obtained from Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified …

Decoupling Body Shape And Mass Distribution In Birds And Their Dinosaurian Ancestors, Sophie Macaulay, Tatjana Hoehfurtner, Samuel R.R. Cross, Ryan D. Marek, John R. Hutchinson, Emma R. Schachner, Alice E. Maher, Karl T. Bates

School of Medicine Faculty Publications

It is accepted that non-avian theropod dinosaurs, with their long muscular tails and small forelimbs, had a centre-of-mass close to the hip, while extant birds, with their reduced tails and enlarged wings have their mass centred more cranially. Transition between these states is considered crucial to two key innovations in the avian locomotor system: crouched bipedalism and powered flight. Here we use image-based models to challenge this dichotomy. Rather than a phylogenetic distinction between ‘dinosaurian’ and ‘avian’ conditions, we find terrestrial versus volant taxa occupy distinct regions of centre-of-mass morphospace consistent with the disparate demands of terrestrial bipedalism and flight. …

The Top 50 Most Cited Articles On The Medial Patellofemoral Ligament (Mpfl): A Bibliometric Analysis, Varag Abed, Alex Duvall, Jonathan D. Rexroth, Alyssa Goodwin, Joseph Liu, Austin Stone

Medical Student Research Symposium

Objectives: To determine which original articles on the topic of the medial patellofemoral ligament (MPFL) have been cited the most in the literature utilizing a bibliometric approach. Secondarily, to determine temporal trends between article types.

Methods: Articles on the topic of the MPFL were identified by utilizing the Web of Science Database. The search yielded 1,596 results and the top 50 cited original articles were collected for further analysis. The following information was gathered for all included articles: title, first author's name, journal name, year of publication, impact factor of the journal in 2021, total number of citations of the …

A New Era Of Morphological Investigations: Reviewing Methods For Comparative Anatomical Studies, K. L. Ford, J. S. Albert, A. P. Summers, B. P. Hedrick, E. R. Schachner, A. S. Jones, K. Evans, P. Chakrabarty

School of Medicine Faculty Publications

The increased use of imaging technology in biological research has drastically altered morphological studies in recent decades and allowed for the preservation of important collection specimens alongside detailed visualization of bony and soft-tissue structures. Despite the benefits associated with these newer imaging techniques, there remains a need for more "tra- ditional"methods of morphological examination in many comparative studies. In this paper, we describe the costs and benefits of the various methods of visualizing, examining, and comparing morphological structures. There are significant differences not only in the costs associated with these different methods (monetary, time, equipment, and software), but also in …

Acute Acat1/Soat1 Blockade Increases Mam Cholesterol And Strengthens Er-Mitochondria Connectivity., Taylor C Harned, Radu V Stan, Ze Cao, Rajarshi Chakrabarti, Henry N Higgs, Catherine C Y Chang, Ta Yuan Chang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Cholesterol is a key component of all mammalian cell membranes. Disruptions in cholesterol metabolism have been observed in the context of various diseases, including neurodegenerative disorders such as Alzheimer's disease (AD). The genetic and pharmacological blockade of acyl-CoA:cholesterol acyltransferase 1/sterol O-acyltransferase 1 (ACAT1/SOAT1), a cholesterol storage enzyme found on the endoplasmic reticulum (ER) and enriched at the mitochondria-associated ER membrane (MAM), has been shown to reduce amyloid pathology and rescue cognitive deficits in mouse models of AD. Additionally, blocking ACAT1/SOAT1 activity stimulates autophagy and lysosomal biogenesis; however, the exact molecular connection between the ACAT1/SOAT1 blockade and these observed benefits remain …

Optimization Of Cryo-Electron Microscopy For Quantitative Analysis Of Lipid Bilayers, Frederick A Heberle, Doug Welsch, Haden L Scott, M Neal Waxham

Faculty, Staff and Student Publications

Cryogenic electron microscopy (cryo-EM) is among the most powerful tools available for interrogating nanoscale structure of biological materials. We recently showed that cryo-EM can be used to measure the bilayer thickness of lipid vesicles and biological membranes with subangstrom precision, resulting in the direct visualization of nanoscopic domains of different thickness in multicomponent lipid mixtures and giant plasma membrane vesicles. Despite the great potential of cryo-EM for revealing the lateral organization of biomembranes, a large parameter space of experimental conditions remains to be optimized. Here, we systematically investigate the influence of instrument parameters and image postprocessing steps on the ability …

Supporting A Culture Of Patient Safety: Resident-Led Patient Safety Event Reviews In A Pathology Residency Training Program, Catherine Tucker, Rebecca C. Jaffe,, Allison F Goldberg

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Patient safety is a critical component of quality patient care at any healthcare institution. In order to support a culture of patient safety, and in the context of a hospital-wide patient safety initiative at our institution, we have created and implemented a new patient safety curriculum within our training program. The curriculum is embedded in an introductory course for first-year residents, in which residents gain an understanding of the multifaceted role of the pathologist in patient care. The patient safety curriculum is a resident-centered event review process and includes 1) identification and reporting of a patient safety event, 2) event …

Estimated Impact Of Low Isolate Numbers On The Reliability Of Cumulative Antibiogram Data, Christian Tran, John Hargy, Bryan Hess, Matthew Pettengill

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Antibiograms are cumulative reports of antimicrobial susceptibility results that are used to guide the selection of empirical antibiotic therapy. Although Clinical and Laboratory Standards Institute (CLSI) guidelines recommend including only organisms that have at least 30 isolates in an antibiogram, previous studies demonstrated that adherence to this recommendation is highly variable. This paper aims to model the impact of small sample sizes on expected levels of error in cumulative antibiograms by comparing percent susceptibility results for random samples to those of the larger, entire data set. The results demonstrate relatively high error rates when utilizing low numbers of isolates in …

Positioning The Brainstem Within The Neural Network Of Threat Prediction, Xu O Zhang, Fabricio H Do Monte

Faculty, Staff and Student Publications

In a recent study, Strickland and McDannald dissected the role of brainstem networks in threat prediction. Using probabilistic threat discrimination in rats, the authors demonstrated that brainstem neurons estimate threat probability and generate positive aversive prediction errors after unexpected outcomes. Their findings suggest that, beyond organizing defensive behaviors, brainstem neurons are involved in threat prediction computations.

Trogocytosis Of Neurons And Glial Cells By Microglia In A Healthy Adult Macaque Retina, Megan Goyal, Andrea S Bordt, Jay Neitz, David W Marshak

Faculty, Staff and Student Publications

Microglial cells are the primary resident immune cells in the retina. In healthy adults, they are ramified; that is, they have extensive processes that move continually. In adult retinas, microglia maintain the normal structure and function of neurons and other glial cells, but the mechanism underlying this process is not well-understood. In the mouse hippocampus, microglia engulf small pieces of axons and presynaptic terminals via a process called trogocytosis. Here we report that microglia in the adult macaque retina also engulf pieces of neurons and glial cells, but not at sites of synapses. We analyzed microglia in a volume of …

Molecular Subtyping And Survival Analysis Of Osteosarcoma Reveals Prognostic Biomarkers And Key Canonical Pathways, Siddesh Southekal, Sushil Kumar Shakyawar, Prachi Bajpai, Amr Elkholy, Upender Manne, Nitish Kumar Mishra, Chittibabu Guda

Journal Articles: Genetics, Cell Biology & Anatomy

Osteosarcoma (OS) is a common bone malignancy in children and adolescents. Although histological subtyping followed by improved OS treatment regimens have helped achieve favorable outcomes, a lack of understanding of the molecular subtypes remains a challenge to characterize its genetic heterogeneity and subsequently to identify diagnostic and prognostic biomarkers for developing effective treatments. In the present study, global analysis of DNA methylation, and mRNA and miRNA gene expression in OS patient samples were correlated with their clinical characteristics. The mucin family of genes, MUC6, MUC12, and MUC4, were found to be highly mutated in the OS patients. …

A Facile Strategy For The Fabrication Of Cell-Laden Porous Alginate Hydrogels Based On Two-Phase Aqueous Emulsions, Wen Xue, Donghee Lee, Yunfan Kong, Mitchell A. Kuss, Ying Huang, Taesung Kim, Soonkyu Chung, Andrew T. Dudley, Seung-Hyun Ro, Bin Duan

Journal Articles: Genetics, Cell Biology & Anatomy

Porous alginate (Alg) hydrogels possess many advantages as cell carriers. However, current pore generation methods require either complex or harsh fabrication processes, toxic components, or extra purification steps, limiting the feasibility and affecting the cellular survival and function. In this study, a simple and cell-friendly approach to generate highly porous cell-laden Alg hydrogels based on two-phase aqueous emulsions is reported. The pre-gel solutions, which contain two immiscible aqueous phases of Alg and caseinate (Cas), are cross-linked by calcium ions. The porous structure of the hydrogel construct is formed by subsequently removing the Cas phase from the ion-cross-linked Alg hydrogel. Those …

Rescue Of Auditory Function By A Single Administration Of Aav-Tmprss3 Gene Therapy In Aged Mice Of Human Recessive Deafness Dfnb8, Wan Du, Volkan Ergin, Corena Loeb, Mingqian Huang, Stewart Silver, Ariel Miura Armstrong, Zaohua Huang, Channabasavaiah B. Gurumurthy, Hinrich Staecker, Xuezhong Liu, Zheng-Yi Chen

Journal Articles: Genetics, Cell Biology & Anatomy

Patients with mutations in the TMPRSS3 gene suffer from recessive deafness DFNB8/DFNB10. For these patients, cochlear implantation is the only treatment option. Poor cochlear implantation outcomes are seen in some patients. To develop biological treatment for TMPRSS3 patients, we generated a knockin mouse model with a frequent human DFNB8 TMPRSS3 mutation. The Tmprss3^A306T/A306T homozygous mice display delayed onset progressive hearing loss similar to human DFNB8 patients. Using AAV2 as a vector to carry a human TMPRSS3 gene, AAV2-hTMPRSS3 injection in the adult knockin mouse inner ear results in TMPRSS3 expression in the hair cells and the spiral ganglion neurons. …

Sp1 Trans-Activates The Murine H+-K+-Atpase Α2-Subunit Gene, Xiaobo Wang, Yili Zhang, Xiuyun Zhou, Xiumei Xia, Weijun Teng, Lin Sheng, Jing Ding

Faculty, Staff and Student Publications

Acute lung injury (ALI) followed with severe inflammation and oxidative stress. Anti-inflammatory and antioxidant are the properties of aquaporin 1 (AQP1) and aquaporin 5 (AQP5). The goal of this study was to see if soy isoflavone can diminish lipopolysaccharide (LPS)-induced ALI and the underling mechanism. LPS-induced ALI was given to Sprague-Dawley rats 14 days following oophorectomy. One hour before the LPS challenge, estradiol (1 mg/kg) was administered subcutaneously as positive control and soy isoflavone was intragastric administration for 14 days prior to LPS challenge with different doses. Six hours after LPS challenge, the pulmonary edema, pathophysiology, inflammation, and the oxidative …

Dynamics And Mechanisms Of Erk Activation After Different Protocols That Induce Long-Term Synaptic Facilitation In Aplysia, Yili Zhang, Rong-Yu Liu, Paul Smolen, Leonard J Cleary, John H Byrne

Faculty, Staff and Student Publications

Phosphorylation of the MAPK family member extracellular signal–regulated kinase (ERK) is required to induce long-term synaptic plasticity, but little is known about its persistence. We examined ERK activation by three protocols that induce long-term synaptic facilitation (LTF) of the Aplysia sensorimotor synapse – the standard protocol (five 5-min pulses of 5-HT with interstimulus intervals (ISIs) of 20 min), the enhanced protocol (five pulses with irregular ISIs, which induces greater and longer-lasting LTF) and the two-pulse protocol (two pulses with ISI 45 min). Immunofluorescence revealed complex ERK activation. The standard and two-pulse protocols immediately increased active, phosphorylated ERK (pERK), which decayed …

Educator Perspectives On Non-Technical, Discipline-Independent Skill Acquisition: An International, Qualitative Study, Jessica N. Byram, Sonya E. Van Nuland, Kelly M. Harrell, Jason C. Mussell, Jon Cornwall

School of Medicine Faculty Publications

Gross anatomy education utilizing body donors and human specimens assists the acquisition of non-traditional, discipline-independent skills (NTDIS) such as teamwork, communication, and leadership. Alterations to anatomy curricula, such as those resulting from the COVID-19 pandemic, likely impact NTDIS acquisition, yet how this manifests is unclear. This study, therefore, explored anatomy educator perspectives on NTDIS acquisition as a response to changes in teaching delivery. Gross anatomy educators across different countries were recruited and took part in one-on-one, semi-structured interviews that were audio recorded and transcribed. Data were analyzed using the framework method. Basic statistical analyses were performed on demographic and categorical …

Syntaxin 3b Is A T-Snare Specific For Ribbon Synapses Of The Retina, Mariajose Perez-Hurtado, Calvin Dao, Amanda E Saenz, Ruth Heidelberger

Faculty, Staff and Student Publications

Biallelic loss-of-function mutations in the syntaxin 3 gene have been linked to a severe retinal dystrophy in humans that presents in early childhood. In mouse models, biallelic inactivation of the syntaxin 3 gene in photoreceptors rapidly leads to their death. What is not known is whether a monoallelic syntaxin 3 loss-of-function mutation might cause photoreceptor loss with advancing age. To address this question, we compared the outer nuclear layer of older adult mice (≈ 20 months of age) that were heterozygous for syntaxin 3 with those of similarly-aged control mice. We found that the photoreceptor layer maintains its thickness in …

Alterations In Static And Dynamic Regional Homogeneity In Mesial Temporal Lobe Epilepsy With And Without Initial Precipitating Injury, Xinyue Mao, Xiaonan Zhang, Chengru Song, Keran Ma, Kefan Wang, Xin Wang, Yajun Lian, Yong Zhang, Shaoqiang Han, Jingliang Cheng, Yan Zhang

Faculty, Staff and Student Publications

Objectives

Initial precipitating injury (IPI) such as febrile convulsion and intracranial infection will increase the susceptibility to epilepsy. It is still unknown if the functional deficits differ between mesial temporal lobe epilepsy with IPI (mTLE-IPI) and without IPI (mTLE-NO).

Methods

We recruited 25 mTLE-IPI patients, 35 mTLE-NO patients and 33 healthy controls (HC). Static regional homogeneity (sReHo) and dynamic regional homogeneity (dReHo) were then adopted to estimate the alterations of local neuronal activity. One-way analysis of variance was used to analyze the differences between the three groups in sReHo and dReHo. Then the results were utilized as masks for further …

Traumatic Brain Injury-Associated Epigenetic Changes And The Risk For Neurodegenerative Diseases, Paul Smolen, Pramod K Dash, John B Redell

Faculty, Staff and Student Publications

Epidemiological studies have shown that traumatic brain injury (TBI) increases the risk for developing neurodegenerative diseases (NDs). However, molecular mechanisms that underlie this risk are largely unidentified. TBI triggers widespread epigenetic modifications. Similarly, NDs such as Alzheimer's or Parkinson's are associated with numerous epigenetic changes. Although epigenetic changes can persist after TBI, it is unresolved if these modifications increase the risk of later ND development and/or dementia. We briefly review TBI-related epigenetic changes, and point out putative feedback loops that might contribute to long-term persistence of some modifications. We then focus on evidence suggesting persistent TBI-associated epigenetic changes may contribute …