Rush University View Institution's Website 3 articles published in JoVE Biology Neutron Radiography and Computed Tomography of Biological Systems at the Oak Ridge National Laboratory's High Flux Isotope Reactor Hassina Z. Bilheux*1, Maria Cekanova*2,3,4, Jeffrey M. Warren*5, Matthew J. Meagher6, Ryan D. Ross6, Jean C. Bilheux1,7, Singanallur Venkatakrishnan8, Jiao Y.Y. Lin1,9, Yuxuan Zhang1, Matthew R. Pearson9,10, Erik Stringfellow1 1Neutron Scattering Division, Oak Ridge National Laboratory, 2College of Veterinary Medicine, The University of Tennessee, 3UT-ORNL Graduate School of Genome, Science and Technology, The University of Tennessee, 4Integrity Laboratories, 5Environmental Sciences Division, Oak Ridge National Laboratory, 6Department of Cell & Molecular Medicine, Rush Medical College, Rush University, 7Computer Science and Mathematics Division, Oak Ridge National Laboratory, 8Electrification and Energy Infrastructures Division, Oak Ridge National Laboratory, 9Now at Second Target Station Project, Oak Ridge National Laboratory, 10Neutron Technologies Division, Oak Ridge National Laboratory This manuscript describes a protocol for neutron radiography and computed tomography of biological samples using a High Flux Isotope Reactor (HFIR) CG-1D beamline to measure a metal implant in a rat femur, a mouse lung, and an herbaceous plant root/soil system. Biology Long-term Silencing of Intersectin-1s in Mouse Lungs by Repeated Delivery of a Specific siRNA via Cationic Liposomes. Evaluation of Knockdown Effects by Electron Microscopy Cristina Bardita*1, Dan Predescu*1,2, Sanda Predescu1,2 1Department of Pharmacology, Rush University, 2Pulmonary and Critical Care Department, Rush University Repeated retro-orbital injections of cationic liposomes/siRNA/ITSN-1s complexes in mice, every 72 hours for 24 days, efficiently deliver the siRNA duplex to the mouse lung microvasculature reducing ITSN-1s mRNA and protein expression by 75%. This technique is highly reproducible in an animal model, has no adverse effects and avoids fatalities. Immunology and Infection Preparation and Use of HIV-1 Infected Primary CD4+ T-Cells as Target Cells in Natural Killer Cell Cytotoxic Assays Zachary B. Davis1, Jeffrey P. Ward1, Edward Barker1 1Department of Immunology and Microbiology, Rush University Medical Center Cytotoxicity assays to measure natural killer cell lytic responses to HIV-infected cells is limited by the purity of the target cells. We demonstrate here the isolation of a highly purified population of HIV-1 infected primary T-cell blasts by taking advantage of HIV-1 s ability to down-modulate CD4.