Medicine and Health Sciences Commons^™

Volumetry Of Low-Contrast Liver Lesions With Ct: Investigation Of Estimation Uncertainties In A Phantom Study, Qin Li, Yongguang Liang, Qiao Huang, Min Zong, Benjamin Berman, Marios A. Gavrielides, Lawrence H. Schwartz, Binsheng Zhao, Nicholas Petrick

Food and Drug Administration Papers

Purpose: To evaluate the performance of lesion volumetry in hepatic CT as a function of various imaging acquisition parameters.

Methods: An anthropomorphic abdominal phantom with removable liver inserts was designed for this study. Two liver inserts, each containing 19 synthetic lesions with varying diameter (6–40 mm), shape, contrast (10–65 HU), and both homogenous and mixed-density were designed to have background and lesion CT values corresponding to arterial and portal-venous phase imaging, respectively. The two phantoms were scanned using two commercial CT scanners (GE 750 HD and Siemens Biograph mCT) across a set of imaging protocols (four slice thicknesses, …

High-Throughput Screening Of Clinically Approved Drugs That Prime Polyethylenimine Transfection Reveals Modulation Of Mitochondria Dysfunction Response Improves Gene Transfer Efficiencies, Albert Nguyen, Jared P. Beyersdorf, Jean-Jack Riethoven, Angela K. Pannier

Biological Systems Engineering: Papers and Publications

Nonviral gene delivery methods are advantageous over viral vectors in terms of safety, cost, and flexibility in design and application, but suffer from lower gene transfer efficiency. In addition to modifications to nucleic acid design and nonviral carriers, new tools are sought to enhance transfection. Priming is the pharmacological modulation of transfection efficiency and transgene expression, and has demonstrated transfection increase in several compounds, for example, chloroquine and glucocorticoids. To develop a library of transfection priming compounds, a highthroughput screen was performed of the NIH Clinical Collection (NCC) to identify clinical compounds that prime polyethylenimine (PEI) transfection. HEK293T cells were …

Micro- And Nanoparticulates For Dna Vaccine Delivery, Eric Farris, Deborah M. Brown, Amanda Ramer-Tait, Angela K. Pannier

Biological Systems Engineering: Papers and Publications

DNA vaccination has emerged as a promising alternative to traditional protein-based vaccines for the induction of protective immune responses. DNA vaccines offer several advantages over traditional vaccines, including increased stability, rapid and inexpensive production, and flexibility to produce vaccines for a wide variety of infectious diseases. However, the immunogenicity of DNA vaccines delivered as naked plasmid DNA is often weak due to degradation of the DNA by nucleases and inefficient delivery to immune cells. Therefore, biomaterial-based delivery systems based on micro- and nanoparticles that encapsulate plasmid DNA represent the most promising strategy for DNA vaccine delivery. Microparticulate delivery systems allow …

“Zipped Synthesis” By Cross-Metathesis Provides A Cystathionine Β‑Synthase Inhibitor That Attenuates Cellular H2S Levels And Reduces Neuronal Infarction In A Rat Ischemic Stroke Model, Christopher D. Mccune, Su Jing Chan, Matthew L. Beio, Weijun Shen, Woo Jin Chung, Laura M. Szczesniak, Chou Chai, Shu Qing Koh, Peter T.-H. Wong, David B. Berkowitz

David Berkowitz Publications

The gaseous neuromodulator H₂S is associated with neuronal cell death pursuant to cerebral ischemia. As cystathionine β-synthase (CBS) is the primary mediator of H2S biogenesis in the brain, it has emerged as a potential target for the treatment of stroke. Herein, a “zipped” approach by alkene cross-metathesis into CBS inhibitor candidate synthesis is demonstrated. The inhibitors are modeled after the pseudo-C₂-symmetric CBS product (L,L)-cystathionine. The “zipped” concept means only half of the inhibitor needs be constructed; the two halves are then fused by olefin cross-metathesis. Inhibitor design is also mechanism-based, exploiting the favorable kinetics associated with …

Investigation Of Tattoo Pigments By Raman Spectroscopy, Betsy Jean Yakes, Tara Jade Michael, Marianita Perez-Gonzalez, Bhakti Petigara Harp

Food and Drug Administration Papers

As a result of the increase in the practice of tattooing, the US Food and Drug Administration has identified a need for improved analytical methods to detect the pigments and potential impurities in the inks. Raman spectroscopy allows for nondestructive identification of compounds and is commonly used in art, archaeology, and forensics; however, the technique has only limitedly been applied to the identification of tattoo pigments. In this study, approximately 30 inorganic, organometallic, and organic pigmentswere evaluated with Raman spectroscopy by using 532, 633, and 780-nmlasers. Individual optimization of the instrumental parameters was performed for each pigment in order to …

Bacterial Endotoxin Detection In Hyaluronic Acid-Based Medical Devices, Larissa F. Baeva, Srilekha Sarkar Das, Victoria M. Hitchins

Food and Drug Administration Papers

A simple and rapid method has been developed for testing bacterial endotoxin in hyaluronic acid (HA)-based medical devices. High-molecular-weight HA (HMW HA) in solution or HA-based medical devices was digested by the enzyme hyaluronidase to reduce solution viscosity by truncating the long chains of HA and to test for bacterial endotoxin. The bacterial endotoxin level was detected and measured by kinetic chromogenic Limulus Amebocyte Lysate (LAL) assay. The method was applied to two different ophthalmic viscosurgical devices (OVDs) and one dermal filler, and may easily be adapted to use with up to 3% HA solutions and other HA-based medical devices.

Pharmacokinetics And Distribution In Interstitial And Pulmonary Epithelial Lining Fluid Of Danofloxacin In Ruminant And Preruminant Calves, D. A. Mzyk, R. E. Baynes, K. M. Messenger, M. Martinez, G. W. Smith

Food and Drug Administration Papers

The objective of this study was to compare active drug concentrations in the plasma vs. different effector compartments including interstitial fluid (ISF) and pulmonary epithelial lining fluid (PELF) of healthy preruminating (3-week-old) and ruminating (6-month-old) calves. Eight calves in each age group were given a single subcutaneous (s.c.) dose (8 mg/kg) of danofloxacin. Plasma, ISF, and bronchoalveolar lavage (BAL) fluid were collected over 96 h and analyzed by high-pressure liquid chromatography. PELF concentrations were calculated by a urea dilution assay of the BAL fluids. Plasma protein binding was measured using a microcentrifugation system. For most preruminant and ruminant calves, the …