Medical Biophysics Commons^™

Intermembrane Coupling Between Bcl-Xl And The Ip3 Receptor Supports Local Ca2+ Transfer At Er-Mitochondrial Contacts, Arijita Ghosh, David Weaver, Chi Li, György Hajnóczky

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Bcl-xL, an anti-apoptotic Bcl-2 family protein, engages laterally with Bak/Bax in the outer mitochondrial membrane (OMM) to inhibit apoptosis and interacts with the IP₃ receptor Ca²⁺ channels (IP3Rs) in the endoplasmic reticulum (ER) membrane to control Ca²⁺ release. It is unknown if OMM-localized Bcl-xL can also interact in trans with IP3Rs at ER-mitochondrial contacts to form a tethering complex that supports IP3R-mediated local Ca²⁺ transfer from ER to mitochondria. We establish that IP3R-mitochondria Ca²⁺ signal propagation depends on Bcl-xL. By targeting Bcl-xL specifically to different subcellular compartments, we find that OMM-localized Bcl-xL increases the efficacy …

Clinical Validation Of Perfusion Imaging With Pulmonary Function Test Data Using Voronoi-Based Discretization, Jorge Cisneros, Caleb J. Herrera, Yi-Kuan Liu, Lisa V. Du, Yevgeniy Vinogradskiy, Richard Castillo, Girish Nair, Edward Castillo

Department of Medicine Faculty Papers

Objective.Accurate lung function assessment is essential for diagnosing and managing diseases like chronic obstructive pulmonary disorder, pulmonary emboli, and lung cancer. Single-photon emission computed tomography (SPECT) provides valuable 3D functional imaging of ventilation and perfusion, but is limited by low spatial resolution, availability, additional radiation, and cost. Alternative methods, including CT-based perfusion (CT-P) and deep learning models, require large datasets to validate results that are often scarce. Pulmonary function tests (PFTs) offer rapid and noninvasive global lung function measures and are clinically widely used. While ventilation correlates well with PFTs, perfusion imaging presents challenges due to complex blood flow and …

Tumor Necrosis Factor Alpha Inhibition Improves Fetal Growth In A Rat Model Of Preeclampsia, Laura E. Coats, Nathan Campbell, Dylan Solise, Gabrielle M. Chamoun, Adam Z. Rawls, Alexandra Demesa, Ty Turner, Baoying Zheng, Barbara T. Alexander, Babbette Lamarca

Physiology & Biophysics

Introduction

Exploring The Impact Of Biological Sex On Intrinsic Connectivity Networks In Ptsd: A Data-Driven Approach., Andrew A Nicholson, Jonathan M Lieberman, Niki Hosseini-Kamkar, Kristen Eckstrand, Daniela Rabellino, Breanne Kearney, David Steyrl, Sandhya Narikuzhy, Maria Densmore, Jean Théberge, Fardous Hosseiny, Ruth A Lanius

Medical Biophysics Publications

INTRODUCTION: Sex as a biological variable (SABV) may help to account for the differential development and expression of post-traumatic stress disorder (PTSD) symptoms among trauma-exposed males and females. Here, we investigate the impact of SABV on PTSD-related neural alterations in resting-state functional connectivity (rsFC) within three core intrinsic connectivity networks (ICNs): the salience network (SN), central executive network (CEN), and default mode network (DMN).

METHODS: Using an independent component analysis (ICA), we compared rsFC of the SN, CEN, and DMN between males and females, with and without PTSD (n = 47 females with PTSD, n = 34 males with PTSD, …

Identification Of Immune-Associated Biomarkers Of Diabetes Nephropathy Tubulointerstitial Injury Based On Machine Learning: A Bioinformatics Multi-Chip Integrated Analysis, Lin Wang, Jiaming Su, Zhongjie Liu, Shaowei Ding, Yaotan Li, Baoluo Hou, Yuxin Hu, Zhaoxi Dong, Jingyi Tang, Hongfang Liu, Weijing Liu

Faculty, Staff and Student Publications

BACKGROUND: Diabetic nephropathy (DN) is a major microvascular complication of diabetes and has become the leading cause of end-stage renal disease worldwide. A considerable number of DN patients have experienced irreversible end-stage renal disease progression due to the inability to diagnose the disease early. Therefore, reliable biomarkers that are helpful for early diagnosis and treatment are identified. The migration of immune cells to the kidney is considered to be a key step in the progression of DN-related vascular injury. Therefore, finding markers in this process may be more helpful for the early diagnosis and progression prediction of DN.

METHODS: The …

Inter-Individual Variations In Circadian Misalignment-Induced Nafld Pathophysiology In Mice, Nobuya Koike, Yasuhiro Umemura, Hitoshi Inokawa, Isao Tokuda, Yoshiki Tsuchiya, Yuh Sasawaki, Atsushi Umemura, Naoko Masuzawa, Kazuya Yabumoto, Takashi Seya, Akira Sugimoto, Seung-Hee Yoo, Zheng Chen, Kazuhiro Yagita

Faculty, Staff and Student Publications

Pathological consequences of circadian misalignment, such as shift work, show considerable individual differences, but the lack of mechanistic understanding hinders precision prevention to prevent and mitigate disease symptoms. Here, we employed an integrative approach involving physiological, transcriptional, and histological phenotypes to examine inter-individual differences in pre-symptomatic pathological progression, preceding irreversible disease onset, in wild-type mice exposed to chronic jet-lag (CJL). We observed that CJL markedly increased the prevalence of hepatic steatosis with pronounced inter-individual differences. Stratification of individual mice based on CJL-induced hepatic transcriptomic signature, validated by histopathological analysis, pinpoints dysregulation of lipid metabolism. Moreover, the period and power of …

Editorial; Biophysics Approaches To Investigate Multi-Organ Alcohol-Induced Damage, Janos Paloczi, Youngchan Kim

School of Graduate Studies Faculty Publications

No abstract provided.

Machine Learning For Ecg Diagnosis And Risk Stratification Of Occlusion Myocardial Infarction, Salah S Al-Zaiti, Christian Martin-Gill, Jessica K Zègre-Hemsey, Zeineb Bouzid, Ziad Faramand, Mohammad O Alrawashdeh, Richard E Gregg, Stephanie Helman, Nathan T Riek, Karina Kraevsky-Phillips, Gilles Clermont, Murat Akcakaya, Susan M Sereika, Peter Van Dam, Stephen W Smith, Yochai Birnbaum, Samir Saba, Ervin Sejdic, Clifton W Callaway

Faculty, Staff and Students Publications

Patients with occlusion myocardial infarction (OMI) and no ST-elevation on presenting electrocardiogram (ECG) are increasing in numbers. These patients have a poor prognosis and would benefit from immediate reperfusion therapy, but, currently, there are no accurate tools to identify them during initial triage. Here we report, to our knowledge, the first observational cohort study to develop machine learning models for the ECG diagnosis of OMI. Using 7,313 consecutive patients from multiple clinical sites, we derived and externally validated an intelligent model that outperformed practicing clinicians and other widely used commercial interpretation systems, substantially boosting both precision and sensitivity. Our derived …

The Role Of Native Cysteine Residues In The Oligomerization Of Kcnq1 Channels, Alison Bates, Rebecca B Stowe, Elizabeth M Travis, Lauryn E Cook, Carole Dabney-Smith, Gary A Lorigan

Faculty, Staff and Student Publications

KCNQ1, the major component of the slow-delayed rectifier potassium channel, is responsible for repolarization of cardiac action potential. Mutations in this channel can lead to a variety of diseases, most notably long QT syndrome. It is currently unknown how many of these mutations change channel function and structure on a molecular level. Since tetramerization is key to proper function and structure of the channel, it is likely that mutations modify the stability of KCNQ1 oligomers. Presently, the C-terminal domain of KCNQ1 has been noted as the driving force for oligomer formation. However, truncated versions of this protein lacking the C-terminal …

Mechanosensitive Membrane Proteins: Usual And Unusual Suspects In Mediating Mechanotransduction, Miriam B Goodman, Elizabeth S Haswell, Valeria Vásquez

Faculty, Staff and Student Publications

This Viewpoint, which accompanies a Special Issue focusing on membrane mechanosensors, discusses unifying and unique features of both established and emerging mechanosensitive (MS) membrane proteins, their distribution across protein families and phyla, and current and future challenges in the study of these important proteins and their partners. MS membrane proteins are essential for tissue development, cellular motion, osmotic homeostasis, and sensing external and self-generated mechanical cues like those responsible for touch and proprioception. Though researchers' attention and this Viewpoint focus on a few famous ion channels that are considered the usual suspects as MS mechanosensors, we also discuss some of …

Estimation Of Free Water-Corrected Microscopic Fractional Anisotropy., Nico J J Arezza, Tales Santini, Mohammad Omer, Corey A Baron

Medical Biophysics Publications

Water diffusion anisotropy MRI is sensitive to microstructural changes in the brain that are hallmarks of various neurological conditions. However, conventional metrics like fractional anisotropy are confounded by neuron fiber orientation dispersion, and the relatively low resolution of diffusion-weighted MRI gives rise to significant free water partial volume effects in many brain regions that are adjacent to cerebrospinal fluid. Microscopic fractional anisotropy is a recent metric that can report water diffusion anisotropy independent of neuron fiber orientation dispersion but is still susceptible to free water contamination. In this paper, we present a free water elimination (FWE) technique to estimate microscopic …

Structural Insights Into Cardiolipin Replacement By Phosphatidylglycerol In A Cardiolipin-Lacking Yeast Respiratory Supercomplex, Elena G Govorunova, Oleg A Sineshchekov, Leonid S Brown, Ana-Nicoleta Bondar, John L Spudich

Faculty, Staff and Student Publications

Potassium-selective channelrhodopsins (KCRs) are light-gated K+ channels recently found in the stramenopile protist Hyphochytrium catenoides. When expressed in neurons, KCRs enable high-precision optical inhibition of spiking (optogenetic silencing). KCRs are capable of discriminating K+ from Na+ without the conventional K+ selectivity filter found in classical K+ channels. The genome of H. catenoides also encodes a third paralog that is more permeable for Na+ than for K+. To identify structural motifs responsible for the unusual K+ selectivity of KCRs, we systematically analyzed a series of chimeras and mutants of this protein. We found that mutations of three critical residues in the …

Risking The Wrist, Tyler Mosier, Evan White

Physician Assistant Capstones, 2020-current

Abstract:

Background: Carpal tunnel syndrome (CTS) is now one of the most common workplace injuries, with nearly 50% of patients eventually requiring CTS release surgery as a permanent solution. With a concern of a younger incidence of CTS developing in a technology dependent society, some patients may fear even a minimal loss of function. To our knowledge there has been no study comparing forearm grip strength before symptoms develop to grip strength after the procedure has been performed.

Objectives: The aim of this study was to determine if there was a significant change in strength of the flexor digitorum superficialis …

Use Of Cardiomems Hf Sensor In Management Of Nyha Class Iii Heart Failure, Trevor Andrunik, Anne Eady

Physician Assistant Capstones, 2020-current

Objective: Assess the ability of continuous pulmonary artery pressure monitoring via implantable CardioMEMs HF device to reduce hospitalization in New York Heart Association (NYHA) Class III heart failure patients over the age of 18. Design: Systematic literature review. Methods: Searches were conducted via PubMed and ClinicalTrials.gov using the single search term “CardioMEMs.” Inclusion criteria narrowed results to studies performed in the last 10 years, randomized control trials, cohort studies, and utilizing heart failure related hospitalization as the primary endpoint. Results: The current data unanimously asserts that the CardioMEMs HF device is effective at reducing heart failure related hospitalizations, with secondary …

Mesoscale Structure-Function Relationships In Mitochondrial Transcriptional Condensates, Marina Feric, Azadeh Sarfallah, Furqan Dar, Dmitry Temiakov, Rohit V. Pappu, Tom Misteli

Department of Biochemistry and Molecular Biology Faculty Papers

In live cells, phase separation is thought to organize macromolecules into membraneless structures known as biomolecular condensates. Here, we reconstituted transcription in condensates from purified mitochondrial components using optimized in vitro reaction conditions to probe the structure-function relationships of biomolecular condensates. We find that the core components of the mt-transcription machinery form multiphasic, viscoelastic condensates in vitro. Strikingly, the rates of condensate-mediated transcription are substantially lower than in solution. The condensate-mediated decrease in transcriptional rates is associated with the formation of vesicle-like structures that are driven by the production and accumulation of RNA during transcription. The generation of RNA alters …

Ultrasound 96 Probe Device Protocol For Cancer Cell Treatment, Aisling Field, Brijesh K. Tiwari, James F. Curtin, Julie R M Mondala, Janith Wanigasekara

Articles

Ultrasound is a sound wave with frequencies ranging between 20 kHz and 20 MHz. Ultrasound is able to temporarily and repeatedly open the BBB safely and enhance chemotherapeutic delivery without adverse effects. This novel technique in drug delivery benefits from the powerful ability of ultrasound to produce cavitation activity. Cavitation is the generation and activity of gas-filled bubbles in a medium exposed to ultrasound. As the pressure wave passes through the media, gas bubbles expand at low pressure and contract at high pressure. This leads to oscillation which produces a circulating fluid flow known as microstreaming around the bubble with …

Biophysical Characterization Of Light-Gated Ion Channels Using Planar Automated Patch Clamp, Elena G Govorunova, Oleg A Sineshchekov, Leonid S Brown, John L Spudich

Faculty, Staff and Student Publications

Channelrhodopsins (ChRs) are proteins that guide phototaxis in protists and exhibit light-gated channel conductance when their genes are heterologously expressed in mammalian cells. ChRs are widely used as molecular tools to control neurons and cardiomyocytes with light (optogenetics). Cation- and anion-selective ChRs (CCRs and ACRs, respectively) enable stimulation and inhibition of neuronal activity by depolarization and hyperpolarization of the membrane, respectively. More than 400 natural ChR variants have been identified so far, and high-throughput polynucleotide sequencing projects add many more each year. However, electrophysiological characterization of new ChRs lags behind because it is mostly done by time-consuming manual patch clamp …

Putative Concussion Biomarkers Identified In Adolescent Male Athletes Using Targeted Plasma Proteomics, Michael R. Miller, Michael Robinson, Lisa Fischer, Alicia Dibattista, Maitray A. Patel, Mark Daley, Robert Bartha, Gregory A. Dekaban, Ravi S. Menon, J. Kevin Shoemaker, Eleftherios P. Diamandis, Ioannis Prassas, Douglas D. Fraser

Medical Biophysics Publications

Sport concussions can be difficult to diagnose and if missed, they can expose athletes to greater injury risk and long-lasting neurological disabilities. Discovery of objective biomarkers to aid concussion diagnosis is critical to protecting athlete brain health. To this end, we performed targeted proteomics on plasma obtained from adolescent athletes suffering a sports concussion. A total of 11 concussed male athletes were enrolled at our academic Sport Medicine Concussion Clinic, as well as 24 sex-, age- and activity-matched healthy control subjects. Clinical evaluation was performed and blood was drawn within 72 h of injury. Proximity extension assays were performed for …

Author Correction: Spread Of Pathological Tau Proteins Through Communicating Neurons In Human Alzheimer’S Disease (Nature Communications, (2020), 11, 1, (2612), 10.1038/S41467-020-15701-2), Jacob W. Vogel, Yasser Iturria-Medina, Olof T. Strandberg, Ruben Smith, Elizabeth Levitis, Alan C. Evans, Oskar Hansson, Michael Weiner, Paul Aisen, Ronald Petersen, Clifford R. Jack, William Jagust, John Q. Trojanowki, Arthur W. Toga, Laurel Beckett, Robert C. Green, Andrew J. Saykin, John Morris, Leslie M. Shaw, Enchi Liu, Tom Montine, Ronald G. Thomas, Michael Donohue, Sarah Walter, Devon Gessert, Tamie Sather, Gus Jiminez, Danielle Harvey, Michael Donohue, Matthew Bernstein, Nick Fox, Paul Thompson

Medical Biophysics Publications

The original version of the Supplementary information associated with this Article inadvertently omitted Supplementary Table S1. The HTML has been updated to include a corrected version of the Supplementary information.

Correlation Between Alzheimer’S Disease And Type 2 Diabetes Using Non-Negative Matrix Factorization, Yeonwoo Chung, Hyunju Lee, Michael W. Weiner, Paul Aisen, Ronald Petersen, Cliford R. Jack, William Jagust, John Q. Trojanowki, Arthur W. Toga, Laurel Beckett, Robert C. Green, Andrew J. Saykin, John Morris, Leslie M. Shaw, Zaven Khachaturian, Greg Sorensen, Maria Carrillo, Lew Kuller, Marc Raichle, Steven Paul, Peter Davies, Howard Fillit, Franz Hefti, Davie Holtzman, M. Marcel Mesulam, William Potter, Peter Snyder, Tom Montine, Ronald G. Thomas, Michael Donohue, Sarah Walter, Tamie Sather

Medical Biophysics Publications

Alzheimer’s disease (AD) is a complex and heterogeneous disease that can be affected by various genetic factors. Although the cause of AD is not yet known and there is no treatment to cure this disease, its progression can be delayed. AD has recently been recognized as a brain-specific type of diabetes called type 3 diabetes. Several studies have shown that people with type 2 diabetes (T2D) have a higher risk of developing AD. Therefore, it is important to identify subgroups of patients with AD that may be more likely to be associated with T2D. We here describe a new approach …

Higher Csf Stnfr1-Related Proteins Associate With Better Prognosis In Very Early Alzheimer’S Disease, William T. Hu, Tugba Ozturk, Alexander Kollhoff, Whitney Wharton, J. Christina Howell, Michael Weiner, Paul Aisen, Ronald Petersen, Clifford R. Jack, William Jagust, John Q. Trojanowki, Arthur W. Toga, Laurel Beckett, Robert C. Green, Andrew J. Saykin, John Morris, Richard J. Perrin, Leslie M. Shaw, Zaven Kachaturian, Maria Carrillo, William Potter, Lisa Barnes, Marie Bernard, Hector González, Carole Ho, John K. Hsiao, Eliezer Masliah, Donna Masterman, Ozioma Okonkwo, Laurie Ryan, Nina Silverberg, Adam Fleisher

Medical Biophysics Publications

Neuroinflammation is associated with Alzheimer’s disease, but the application of cerebrospinal fluid measures of inflammatory proteins may be limited by overlapping pathways and relationships between them. In this work, we measure 15 cerebrospinal proteins related to microglial and T-cell functions, and show them to reproducibly form functionally-related groups within and across diagnostic categories in 382 participants from the Alzheimer’s Disease Neuro-imaging Initiative as well participants from two independent cohorts. We further show higher levels of proteins related to soluble tumor necrosis factor receptor 1 are associated with reduced risk of conversion to dementia in the multi-centered (p = 0.027) and …

Kl-Vs Heterozygosity Is Associated With Lower Amyloid-Dependent Tau Accumulation And Memory Impairment In Alzheimer’S Disease, Julia Neitzel, Nicolai Franzmeier, Anna Rubinski, Martin Dichgans, Matthias Brendel, Michael Weiner, Paul Aisen, Ronald Petersen, Clifford R. Jack, William Jagust, John Q. Trojanowki, Arthur W. Toga, Laurel Beckett, Robert C. Green, Andrew J. Saykin, John Morris, Leslie M. Shaw, Enchi Liu, Tom Montine, Ronald G. Thomas, Michael Donohue, Sarah Walter, Devon Gessert, Tamie Sather, Gus Jiminez, Danielle Harvey, Matthew Bernstein, Nick Fox, Paul Thompson, Norbert Schuff, Charles Decarli, Bret Borowski

Medical Biophysics Publications

Klotho-VS heterozygosity (KL-VShet) is associated with reduced risk of Alzheimer’s disease (AD). However, whether KL-VShet is associated with lower levels of pathologic tau, i.e., the key AD pathology driving neurodegeneration and cognitive decline, is unknown. Here, we assessed the interaction between KL-VShet and levels of beta-amyloid, a key driver of tau pathology, on the levels of PET-assessed neurofibrillary tau in 551 controls and patients across the AD continuum. KL-VShet showed lower cross-sectional and longitudinal increase in tau-PET per unit increase in amyloid-PET when compared to that of non-carriers. This association of KL-VShet on tau-PET was stronger in Klotho mRNA-expressing brain …

Plasma Phosphorylated-Tau181 As A Predictive Biomarker For Alzheimer’S Amyloid, Tau And Fdg Pet Status, Xue Ning Shen, Yu Yuan Huang, Shi Dong Chen, Yu Guo, Lan Tan, Qiang Dong, Jin Tai Yu, Michael W. Weiner, Paul Aisen, Ronald Petersen, Clifford R. Jack, William Jagust, John Q. Trojanowki, John Q. Trojanowki, Arthur W. Toga, Laurel Beckett, Robert C. Green, Andrew J. Saykin, John C. Morris, Richard J. Perrin, Leslie M. Shaw, Maria Carrillo, William Potter, Lisa Barnes, Marie Bernard, Hector González, Carole Ho, John K. Hsiao, Jonathan Jackson, Eliezer Masliah, Donna Masterman, Ozioma Okonkwo

Medical Biophysics Publications

Plasma phosphorylated-tau181 (p-tau181) showed the potential for Alzheimer’s diagnosis and prognosis, but its role in detecting cerebral pathologies is unclear. We aimed to evaluate whether it could serve as a marker for Alzheimer’s pathology in the brain. A total of 1189 participants with plasma p-tau181 and PET data of amyloid, tau or FDG PET were included from ADNI. Cross-sectional relationships of plasma p-tau181 with PET biomarkers were tested. Longitudinally, we further investigated whether different p-tau181 levels at baseline predicted different progression of Alzheimer’s pathological changes in the brain. We found plasma p-tau181 significantly correlated with brain amyloid (Spearman ρ = …

Repetitive Mild Traumatic Brain Injury In Mice Triggers A Slowly Developing Cascade Of Long-Term And Persistent Behavioral Deficits And Pathological Changes, Xiaoyun Xu, Matthew Cowan, Flavio Beraldo, Amy Schranz, Patrick Mccunn, Nicole Geremia, Zalman Brown, Maitray Patel, Karen L. Nygard, Reza Khazaee, Lihong Lu, Xingyu Liu, Michael J. Strong, Gregory A. Dekaban, Ravi Menon, Robert Bartha, Mark Daley, Haojie Mao, Vania Prado, Marco A.M. Prado, Lisa Saksida, Tim Bussey, Arthur Brown

Medical Biophysics Publications

We have previously reported long-term changes in the brains of non-concussed varsity rugby players using magnetic resonance spectroscopy (MRS), diffusion tensor imaging (DTI) and functional magnetic imaging (fMRI). Others have reported cognitive deficits in contact sport athletes that have not met the diagnostic criteria for concussion. These results suggest that repetitive mild traumatic brain injuries (rmTBIs) that are not severe enough to meet the diagnostic threshold for concussion, produce long-term consequences. We sought to characterize the neuroimaging, cognitive, pathological and metabolomic changes in a mouse model of rmTBI. Using a closed-skull model of mTBI that when scaled to human leads …

Staging Tau Pathology With Tau Pet In Alzheimer’S Disease: A Longitudinal Study, Shi Dong Chen, Jia Ying Lu, Hong Qi Li, Yu Xiang Yang, Jie Hui Jiang, Mei Cui, Chuan Tao Zuo, Lan Tan, Qiang Dong, Jin Tai Yu, Michael W. Weiner, Paul Aisen, Ronald Petersen, Clifford R. Jack, William Jagust, John Q. Trojanowki, Arthur W. Toga, Laurel Beckett, Robert C. Green, Andrew J. Saykin, John C. Morris, Richard J. Perrin, Leslie M. Shaw, Maria Carrillo, William Potter, Lisa Barnes, Marie Bernard, Hector González, Carole Ho, John K. Hsiao, Jonathan Jackson, Eliezer Masliah

Medical Biophysics Publications

A biological research framework to define Alzheimer’ disease with dichotomized biomarker measurement was proposed by National Institute on Aging–Alzheimer’s Association (NIA–AA). However, it cannot characterize the hierarchy spreading pattern of tau pathology. To reflect in vivo tau progression using biomarker, we constructed a refined topographic 18F-AV-1451 tau PET staging scheme with longitudinal clinical validation. Seven hundred and thirty-four participants with baseline 18F-AV-1451 tau PET (baseline age 73.9 ± 7.7 years, 375 female) were stratified into five stages by a topographic PET staging scheme. Cognitive trajectories and clinical progression were compared across stages with or without further dichotomy of amyloid status, …

Magnetic Resonance Imaging Sequence Identification Using A Metadata Learning Approach, Shuai Liang, Derek Beaton, Stephen R. Arnott, Tom Gee, Mojdeh Zamyadi, Robert Bartha, Sean Symons, Glenda M. Macqueen, Stefanie Hassel, Jason P. Lerch, Evdokia Anagnostou, Raymond W. Lam, Benicio N. Frey, Roumen Milev, Daniel J. Müller, Sidney H. Kennedy, Christopher J.M. Scott, Stephen C. Strother

Medical Biophysics Publications

Despite the wide application of the magnetic resonance imaging (MRI) technique, there are no widely used standards on naming and describing MRI sequences. The absence of consistent naming conventions presents a major challenge in automating image processing since most MRI software require a priori knowledge of the type of the MRI sequences to be processed. This issue becomes increasingly critical with the current efforts toward open-sharing of MRI data in the neuroscience community. This manuscript reports an MRI sequence detection method using imaging metadata and a supervised machine learning technique. Three datasets from the Brain Center for Ontario Data Exploration …

Neutrophil Dynamics Affect Mycobacterium Tuberculosis Granuloma Outcomes And Dissemination, Caitlin Hult, Joshua T. Mattila, Hannah P. Gideon, Jennifer J. Linderman, Denise E. Kischner

Math Faculty Publications

Neutrophil infiltration into tuberculous granulomas is often associated with higher bacteria loads and severe disease but the basis for this relationship is not well understood. To better elucidate the connection between neutrophils and pathology in primate systems, we paired data from experimental studies with our next generation computational model GranSim to identify neutrophil-related factors, including neutrophil recruitment, lifespan, and intracellular bacteria numbers, that drive granuloma-level outcomes. We predict mechanisms underlying spatial organization of neutrophils within granulomas and identify how neutrophils contribute to granuloma dissemination. We also performed virtual deletion and depletion of neutrophils within granulomas and found that neutrophils play …

Improved Segmentation Of The Intracranial And Ventricular Volumes In Populations With Cerebrovascular Lesions And Atrophy Using 3d Cnns, Emmanuel E. Ntiri, Melissa F. Holmes, Parisa M. Forooshani, Joel Ramirez, Fuqiang Gao, Miracle Ozzoude, Sabrina Adamo, Christopher J.M. Scott, Dar Dowlatshahi, Jane M. Lawrence-Dewar, Donna Kwan, Anthony E. Lang, Sean Symons, Robert Bartha, Stephen Strother, Jean Claude Tardif, Mario Masellis, Richard H. Swartz, Alan Moody, Sandra E. Black, Maged Goubran

Medical Biophysics Publications

Successful segmentation of the total intracranial vault (ICV) and ventricles is of critical importance when studying neurodegeneration through neuroimaging. We present iCVMapper and VentMapper, robust algorithms that use a convolutional neural network (CNN) to segment the ICV and ventricles from both single and multi-contrast MRI data. Our models were trained on a large dataset from two multi-site studies (N = 528 subjects for ICV, N = 501 for ventricular segmentation) consisting of older adults with varying degrees of cerebrovascular lesions and atrophy, which pose significant challenges for most segmentation approaches. The models were tested on 238 participants, including subjects with …

Nnresting State Fmri Scanner Instabilities Revealed By Longitud Inal Phantom Scans In A Multi-Center Study, Aras Kayvanrad, Stephen R. Arnott, Nathan Churchill, Stefanie Hassel, Aditi Chemparathy, Fan Dong, Mojdeh Zamyadi, Tom Gee, Robert Bartha, Sandra E. Black, Jane M. Lawrence-Dewar, Christopher J.M. Scott, Sean Symons, Andrew D. Davis, Geoffrey B. Hall, Jacqueline Harris, Nancy J. Lobaugh, Glenda Macqueen, Cindy Woo, Stephen Strother

Medical Biophysics Publications

Quality assurance (QA) is crucial in longitudinal and/or multi-site studies, which involve the collection of data from a group of subjects over time and/or at different locations. It is important to regularly monitor the performance of the scanners over time and at different locations to detect and control for intrinsic differences (e.g., due to manufacturers) and changes in scanner performance (e.g., due to gradual component aging, software and/or hardware upgrades, etc.). As part of the Ontario Neurodegenerative Disease Research Initiative (ONDRI) and the Canadian Biomarker Integration Network in Depression (CAN-BIND), QA phantom scans were conducted approximately monthly for three to …

Rapid Microscopic Fractional Anisotropy Imaging Via An Optimized Linear Regression Formulation., N J J Arezza, D H Y Tse, C A Baron

Medical Biophysics Publications

Water diffusion anisotropy in the human brain is affected by disease, trauma, and development. Microscopic fractional anisotropy (μFA) is a diffusion MRI (dMRI) metric that can quantify water diffusion anisotropy independent of neuron fiber orientation dispersion. However, there are several different techniques to estimate μFA and few have demonstrated full brain imaging capabilities within clinically viable scan times and resolutions. Here, we present an optimized spherical tensor encoding (STE) technique to acquire μFA directly from the 2nd order cumulant expansion of the powder averaged dMRI signal obtained from direct linear regression (i.e. diffusion kurtosis) which requires fewer powder-averaged signals than …