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Medical Physiology Commons

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Himmelfarb Health Sciences Library, The George Washington University

Diseases

Articles 1 - 8 of 8

Full-Text Articles in Medical Physiology

Rhythm: An Open Source Imaging Toolkit For Cardiac Panoramic Optical Mapping, Christopher Gloschat, Kedar Aras, Shubnam Gupta, N. Rokhana Faye, Hanyu Zhang, Matthew W. Kay, Igor R Efimov, +Several Additional Authors Jan 2018

Rhythm: An Open Source Imaging Toolkit For Cardiac Panoramic Optical Mapping, Christopher Gloschat, Kedar Aras, Shubnam Gupta, N. Rokhana Faye, Hanyu Zhang, Matthew W. Kay, Igor R Efimov, +Several Additional Authors

Pharmacology and Physiology Faculty Publications

Fluorescence optical imaging techniques have revolutionized the field of cardiac electrophysiology and advanced our understanding of complex electrical activities such as arrhythmias. However, traditional monocular optical mapping systems, despite having high spatial resolution, are restricted to a two-dimensional (2D) field of view. Consequently, tracking complex three-dimensional (3D) electrical waves such as during ventricular fibrillation is challenging as the waves rapidly move in and out of the field of view. This problem has been solved by panoramic imaging which uses multiple cameras to measure the electrical activity from the entire epicardial surface. However, the diverse engineering skill set and substantial resource …


Temporal Changes In Cortical And Hippocampal Expression Of Genes Important For Brain Glucose Metabolism Following Controlled Cortical Impact Injury In Mice, June Zhou, Mark Burns, Linda Huynh, Sonia Villapol, Daniel D. Taub, Juan M. Saavedra, Marc R. Blackman Sep 2017

Temporal Changes In Cortical And Hippocampal Expression Of Genes Important For Brain Glucose Metabolism Following Controlled Cortical Impact Injury In Mice, June Zhou, Mark Burns, Linda Huynh, Sonia Villapol, Daniel D. Taub, Juan M. Saavedra, Marc R. Blackman

Pharmacology and Physiology Faculty Publications

Traumatic brain injury (TBI) causes transient increases and subsequent decreases in brain glucose utilization. The underlying molecular pathways are orchestrated processes and poorly understood. In the current study, we determined temporal changes in cortical and hippocampal expression of genes important for brain glucose/lactate metabolism and the effect of a known neuroprotective drug telmisartan on the expression of these genes after experimental TBI. Adult male C57BL/6J mice (n = 6/group) underwent sham or unilateral controlled cortical impact (CCI) injury. Their ipsilateral and contralateral cortex and hippocampus were collected 6 h, 1, 3, 7, 14, 21, and 28 days after injury. …


Alternative Splicing Promotes Tumour Aggressiveness And Drug Resistance In African American Prostate Cancer., Bi-Dar Wang, Kristin Ceniccola, Sujin Hwang, Ramez Andrawis, Anelia Horvath, Jennifer A Freedman, Jacqueline Olender, Stefan Knapp, Travers Ching, Lana Garmire, Vyomesh Patel, Mariano A Garcia-Blanco, Steven R Patierno, Norman H Lee Jun 2017

Alternative Splicing Promotes Tumour Aggressiveness And Drug Resistance In African American Prostate Cancer., Bi-Dar Wang, Kristin Ceniccola, Sujin Hwang, Ramez Andrawis, Anelia Horvath, Jennifer A Freedman, Jacqueline Olender, Stefan Knapp, Travers Ching, Lana Garmire, Vyomesh Patel, Mariano A Garcia-Blanco, Steven R Patierno, Norman H Lee

Pharmacology and Physiology Faculty Publications

linical challenges exist in reducing prostate cancer (PCa) disparities. The RNA splicing landscape of PCa across racial populations has not been fully explored as a potential molecular mechanism contributing to race-related tumour aggressiveness. Here, we identify novel genome-wide, race-specific RNA splicing events as critical drivers of PCa aggressiveness and therapeutic resistance in African American (AA) men. AA-enriched splice variants of PIK3CD, FGFR3, TSC2 and RASGRP2 contribute to greater oncogenic potential compared with corresponding European American (EA)-expressing variants. Ectopic overexpression of the newly cloned AA-enriched variant, PIK3CD-S, in EA PCa cell lines enhances AKT/mTOR signalling and increases proliferative …


Chemogenetic Stimulation Of The Hypoglossal Neurons Improves Upper Airway Patency, Thomas Curado, Kenneth Fishbein, Huy Pho, Michael Brennick, Olga Dergacheva, David Mendelowitz, +Several Additional Authors Mar 2017

Chemogenetic Stimulation Of The Hypoglossal Neurons Improves Upper Airway Patency, Thomas Curado, Kenneth Fishbein, Huy Pho, Michael Brennick, Olga Dergacheva, David Mendelowitz, +Several Additional Authors

Pharmacology and Physiology Faculty Publications

Obstructive sleep apnea (OSA) is characterized by recurrent upper airway obstruction during sleep. OSA leads to high cardiovascular morbidity and mortality. The pathogenesis of OSA has been linked to a defect in neuromuscular control of the pharynx. There is no effective pharmacotherapy for OSA. The objective of this study was to determine whether upper airway patency can be improved using chemogenetic approach by deploying designer receptors exclusively activated by designer drug (DREADD) in the hypoglossal motorneurons. DREADD (rAAV5-hSyn-hM3(Gq)-mCherry) and control virus (rAAV5-hSyn-EGFP) were stereotactically administered to the hypoglossal nucleus of C57BL/6J mice. In 6–8 weeks genioglossus EMG and dynamic MRI …


Seeing The Invisible: Revealing Atrial Ablation Lesions Using Hyperspectral Imaging Approach, Narine Muselimyan, Luther Swift, Huda Asfour, Tigran Chahbazian, Ramesh Mazhari, Marco Mercader, Narine Sarvazyan Dec 2016

Seeing The Invisible: Revealing Atrial Ablation Lesions Using Hyperspectral Imaging Approach, Narine Muselimyan, Luther Swift, Huda Asfour, Tigran Chahbazian, Ramesh Mazhari, Marco Mercader, Narine Sarvazyan

Pharmacology and Physiology Faculty Publications

Background

Currently, there are limited means for high-resolution monitoring of tissue injury during radiofrequency ablation procedures.

Objective

To develop the next generation of visualization catheters that can reveal irreversible atrial muscle damage caused by ablation and identify viability gaps between the lesions.

Methods

Radiofrequency lesions were placed on the endocardial surfaces of excised human and bovine atria and left ventricles of blood perfused rat hearts. Tissue was illuminated with 365nm light and a series of images were acquired from individual spectral bands within 420-720nm range. By extracting spectral profiles of individual pixels and spectral unmixing, the relative contribution of ablated …


Intranasal Oxytocin Enhances Connectivity In The Neural Circuitry Supporting Social Motivation And Social Perception In Children With Autism., Ilanit Gordon, Allison Jack, Charlotte M Pretzsch, Brent Vander Wyk, James F Leckman, Ruth Feldman, Kevin A. Pelphrey Nov 2016

Intranasal Oxytocin Enhances Connectivity In The Neural Circuitry Supporting Social Motivation And Social Perception In Children With Autism., Ilanit Gordon, Allison Jack, Charlotte M Pretzsch, Brent Vander Wyk, James F Leckman, Ruth Feldman, Kevin A. Pelphrey

Pharmacology and Physiology Faculty Publications

Oxytocin (OT) has become a focus in investigations of autism spectrum disorder (ASD). The social deficits that characterize ASD may relate to reduced connectivity between brain sites on the mesolimbic reward pathway (nucleus accumbens; amygdala) that receive OT projections and contribute to social motivation, and cortical sites involved in social perception. Using functional magnetic resonance imaging and a randomized, double blind, placebo-controlled crossover design, we show that OT administration in ASD increases activity in brain regions important for perceiving social-emotional information. Further, OT enhances connectivity between nodes of the brain's reward and socioemotional processing systems, and does so preferentially for …


Guidelines For Pre-Clinical Assessment Of The Acetylcholine Receptor-Specific Passive Transfer Myasthenia Gravis Model - Recommendations For Methods And Experimental Designs., Linda L. Kusner, Mario Losen, Angela Vincent, Jon Lindstrom, Socrates Tzartos, Konstantinos Lazaridis, Pilar Martinez-Martinez Mar 2015

Guidelines For Pre-Clinical Assessment Of The Acetylcholine Receptor-Specific Passive Transfer Myasthenia Gravis Model - Recommendations For Methods And Experimental Designs., Linda L. Kusner, Mario Losen, Angela Vincent, Jon Lindstrom, Socrates Tzartos, Konstantinos Lazaridis, Pilar Martinez-Martinez

Pharmacology and Physiology Faculty Publications

Antibodies against the muscle acetylcholine receptor (AChR) are the most common cause of myasthenia gravis (MG). Passive transfer of AChR antibodies from MG patients into animals reproduces key features of human disease, including antigenic modulation of the AChR, complement-mediated damage of the neuromuscular junction, and muscle weakness. Similarly, AChR antibodies generated by active immunization in experimental autoimmune MG models can subsequently be passively transferred to other animals and induce weakness. The passive transfer model is useful to test therapeutic strategies aimed at the effector mechanism of the autoantibodies. Here we summarize published and unpublished experience using the AChR passive transfer …


Androgen Receptor-Target Genes In African American Prostate Cancer Disparities, Bi-Dar Wang, Qi Yang, Kristin Ceniccola, Fernando Bianco, Ramez Andrawis, Thomas W. Jarrett, Harold A. Frazier, Steven R. Patierno, Norman H. Lee Jan 2013

Androgen Receptor-Target Genes In African American Prostate Cancer Disparities, Bi-Dar Wang, Qi Yang, Kristin Ceniccola, Fernando Bianco, Ramez Andrawis, Thomas W. Jarrett, Harold A. Frazier, Steven R. Patierno, Norman H. Lee

Pharmacology and Physiology Faculty Publications

The incidence and mortality rates of prostate cancer (PCa) are higher in African American (AA) compared to Caucasian American (CA) men. To elucidate the molecular mechanisms underlying PCa disparities, we employed an integrative approach combining gene expression profiling and pathway and promoter analyses to investigate differential transcriptomes and deregulated signaling pathways in AA versus CA cancers. A comparison of AA and CA PCa specimens identified 1,188 differentially expressed genes. Interestingly, these transcriptional differences were overrepresented in signaling pathways that converged on the androgen receptor (AR), suggesting that the AR may be a unifying oncogenic theme in AA PCa. Gene promoter …