Now showing items 1-20 of 1018

    • ToxTidbits 2021

      University of Maryland, Baltimore. School of Pharmacy. Maryland Poison Center, 2021
    • Poison Prevention Press 2021

      University of Maryland, Baltimore. School of Pharmacy. Maryland Poison Center, 2021
    • Maryland Mentor : 2021

      University of Maryland, Baltimore. School of Pharmacy. Experiential Learning Program, 2021
    • PATIENTS' Voices (2021)

      University of Maryland, Baltimore. School of Pharmacy, 2021
    • Transparency too little, too late? Why and how Health Canada should make clinical data and regulatory decision-making open to scrutiny in the face of COVID-19

      Edmonds, Sterling; MacGregor, Andrea; Doll, Agnieszka; Vural, Ipek Eren; Graham, Janice; Fierlbeck, Katherine; Lexchin, Joel; Doshi, Peter; Herder, Matthew (Oxford University Press, 2020-11-19)
    • Targeting Aberrant alpha-Helix Mediated Protein-Protein Interactions with Densely Functionalized Heterocycles

      Conlon, Ivie; Fletcher, Steven; 0000-0002-8269-299X (2020)
      Protein-protein interactions (PPIs) play crucial roles in cell proliferation, differentiation, and apoptosis. Apoptosis is a highly regulated process of cell death and its dysregulation can lead to a multitude of different pathophysiologies, such as cancer. In particular, the overexpression of pro-life Bcl-2 proteins, such as Bcl-2, Bfl-1, and Mcl-1, has been linked to cancer progression and tumorigenesis, as well as chemoresistance to a number of different chemotherapeutics. The binding counterparts of these proteins, pro-death Bcl-2 proteins such as Bim, and p53 transactivation domain (TAD), exert their effects through α-helix mediated PPIs with key residues i, i+ 3/4, and i+ 7 oriented on one side of the helix. In addition, HDM2, the E3 ubiquitin protein ligase responsible for the degradation of p53, is upregulated in numerous cancers, and given the similarities of the recognition profiles of Bim-BH3 and p53TAD, we have designed α-helix mimetic inhibitors that target Mcl-1 and HDM2. The first generation of compounds included various heterocyclic scaffolds, including isoxazoles, pyrazoles, and thiazoles, that project functional groups in a similar manner to the native α-helices. In addition, bicyclic scaffolds have been utilized in Mcl-1 selective inhibition. Therefore, we developed a second generation of compounds of isoxazoles, pyrazoles, and functionalized indoles to further explore the binding interface of Mcl-1. The recent resurgence of covalent inhibition and targeted protein degradation has led to the development of successful Bcl-2 family inhibitors. We have designed two tris-aryl α-helix mimetic scaffolds targeting the Bfl-1 pro-life protein. A unique surface-accessible cysteine within the BH3 domain allows for the development of reversible and irreversible small molecule covalent inhibitors. In addition, we have also designed a venetoclax-based PROTAC targeting Bcl-2.
    • From Nanoparticles to Zinc Finger Proteins to Electronic Nicotine Delivery Systems: The Clinical and Biomolecular Evaluation of Potentially Toxic Heavy Metals

      Brandis, Joel; Michel, Sarah L. J.; 0000-0003-2163-5243 (2020)
      Physicochemical Properties of Sodium Ferric Gluconate There are concerns that differences in iron release between brand sodium ferric gluconate (SFG) (Ferrlecit) and generic SFG (generic SFG) intravenous (IV) iron nanoparticle drugs, which are used to treat chronic kidney disease can be caused by differences in the products’ physicochemical properties. However, a standardized, SFG product specific, physicochemical measurement regulatory guidance is not available. Iron core measurements including optical spectroscopy, ICP-MS, XRPD, 57Fe Mössbauer spectroscopy, and XAS, found both products’ cores to be similar ferric-iron-oxide structures. Measurements focused on the carbohydrate shell including forced acid degradation, concentration dependent DLS, AUC, and GPC found differences in particle size, acid stability/iron lability, and molecular weight distribution, that may impact iron release. Cadmium Targeting of Tristetraprolin Zinc finger (ZF) proteins regulate inflammation and are a potential target for cadmium. Zinc bound double Cys3His domain ZF protein tristetraprolin (TTP) regulates inflammation by binding to AU-rich cytokine mRNA. Using a TTP peptide (TTP-2D), Zn2-TTP-2D, cadmium was observed to displace Zn in a concentration dependent manner by spin-filter/ICP-MS coupled to native ESI-MS. Cadmium was also found to displace zinc from RNA bound Zn2-TTP-2D complex (Zn2-TTP-2D/RNA) by ESI in a concentration dependent manner, resulting in Cd1Zn1-TTP-2D/RNA and Cd2-TTP-2D/RNA complexes. Using fluorescence anisotropy cadmium displacement of zinc from Zn2-TTP-2D/RNA complex did not disrupt RNA binding. E-Cig E-liquid Matrix’s Effect on Metal Aerosolization Potentially toxic levels of metals, such as chromium, nickel, copper, and lead, have been reported in e-liquids (liquids composed primarily of a mixture of propylene glycol (PG), glycerol (G)) and nicotine, and generated aerosols of electronic nicotine delivery systems (ENDS). However, the variables that affect metal transfer from the e-liquid to the aerosols are unknown. Using a custom ENDS aerosolization device and aerosolization approach, following CORESTA 81 guidance, the aerosolization of metal spiked model e-liquids (PG and G) were measured. Using ICP-MS to measure aerosol metal content to determine the effect of e-liquid on chromium, nickel, copper, and lead, it was found that all four metals are more readily aerosolized in PG dominant e-liquids than G dominant e-liquids.
    • Development of Fast Photochemical Oxidation of Proteins for in Vivo Modification in Caenorhabditis elegans

      Espino, Jessica; Jones, Lisa M.; 0000-0002-7203-9145 (2020)
      Mass spectrometry (MS) has become widely used for the characterization of protein structure and protein-protein interactions (PPI). Unlike many commonly used structural methods, MS is not limited by the size of molecules, thus allowing for the study of a wide range of purified protein complexes, cells, tissues, and complex organisms. Instrumentation advancements have also decreased the need for large sample concentrations and have increased mass accuracy and resolution. In the past decade, MS-based protein footprinting has become increasingly utilized for the determination of higher-order protein structure and provides residue-level analysis on PPI interaction sites, protein-ligand interactions, and regions of conformational change by covalently modifying the solvent-accessible surface area (SASA) of proteins through the use of a small chemical label. The hydroxyl radical protein footprinting (HRPF) method, fast photochemical oxidation of proteins (FPOP), utilizes hydroxyl radicals (•OH) to oxidatively modify solvent-accessible amino acid side chains. These radicals are generated via hydrogen peroxide photolysis using a KrF excimer laser at a 248 nm wavelength. To date, most applications of FPOP have been performed in vitro in relatively pure protein systems. Most notably, it has been applied for antibody epitope mapping, protein folding, and protein aggregation. This work focuses on the extension of FPOP for in vivo protein structural analysis in Caenorhabditis elegans, a method entitled in vivo FPOP (IV-FPOP). FPOP is particular suited for in vivo protein studies because of the irreversible nature of the modification, which mitigates time constraints with respect to sample preparation, proteomic digestion, and sample processing. Additionally, the •OH generated can label 19 out of 20 amino acids allowing for the study of multiple proteins regardless of protein sequence or cellular location. Given the complexity of the platform, numerous parameters required optimization for maximum labeling efficiency including the development of a microfluidic flow system for the labeling of worms by IV-FPOP, hydrogen peroxide concentration optimization, and the addition of chemical penetration enhancers to increase hydrogen peroxide uptake by the worm, and the implementation of a multiplexing proteomics platform increased throughput of IV-FPOP oxidatively modified peptides.
    • Determining the Mechanism and Regulation of the Heme Assimilation System (Has) in Pseudomonas aeruginosa Heme Signaling and Acquisition

      Dent, Alecia T.; Wilks, Angela; 0000-0002-6376-7482 (2020)
      Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen that causes infections in immunocompromised populations including patients with cystic fibrosis, surgical site wounds and pneumonia. Like most other bacterial pathogens, Pseudomonas requires iron for survival and virulence and has adapted several mechanisms including utilizing heme as an iron source. P. aeruginosa encodes two nonredundant heme uptake systems, the heme assimilation system (has) and Pseudomonas heme utilization (phu) pathways. Proteomic and RNA seq analysis of P. aeruginosa show the Has pathway is one of the most upregulated during infection and knockout strains of HasR reduce the pathogenicity of the bacteria in mice elevating it as a potential drug target. Despite previous studies of the S. marcescens Has pathway there has been no comprehensive study of the molecular mechanism by which heme is sensed and transported by the Has pathway. The work herein utilizes a combination of site-directed mutagenesis of the extracellular hemophore HasAp, allelic exchange, quantitative PCR analyses, immunoblotting and 13C-heme uptake studies to elucidate both the mechanism of heme release from HasAp to HasR and its requirement for initiation of the extracellularcytoplasmic function (ECF) HasIS sigma/anti-sigma factor system. Furthermore, I show in contrast to the S. marcescens system the hasIS operon is not subject to autoregulation by HasI, but rather post-transcriptional regulation through modulation of HasAp. Employing similar approaches with the outer membrane receptor HasR, I determined heme capture by H221 on the plug domain of HasR is required for signaling and transport, whereas mutations to the extracellular FRAP/PNPL loop H624 and L8 loop Ile694 are competent to signal but not transport heme. Based on my studies, I propose a model for heme signaling and transport by the P. aeruginosa Has system that provides a foundation for further studies of heme uptake and a starting point for the development of novel antimicrobial strategies.
    • Expanding the Use of FPOP for In Vitro and In Cell Studies

      Chea, Emily E.; Jones, Lisa M. (2020)
      Studying higher order protein structure is crucial to better understand protein interactions and functions. Mass spectrometry (MS) has been an invaluable tool to better understand protein structure. Several techniques, like protein footprinting, are coupled with mass spectrometry to gain information on protein structure and changes in protein-protein and protein-ligand interactions. Hydroxyl radical protein footprinting (HRPF) utilizes hydroxyl radicals to irreversibly label solvent-exposed side chains of 19 out of the 20 amino acids. Traditionally, modified regions are detected using bottom-up proteomics and with MS/MS analysis, residue level information can be obtained. There are a handful of techniques to generate hydroxyl radicals, one is fast photochemical oxidation of proteins (FPOP). FPOP generates hydroxyl radicals through the photolysis of hydrogen peroxide using a 248 nm excimer laser. My research aims to expand the use of FPOP for in vitro and in cell studies. For in-vitro FPOP the first objective was to validate the use of FPOP to study proteins in their native structure. In all protein footprinting techniques, it is crucial to label while the protein remains in its native structure and ensure labeling does not take place if the protein begins to unfold. To confirm FPOP probed proteins in their native state, the enzymatic activity of proteins were measured before and after FPOP. The second objective was to combine FPOP with native MS, ion mobility separation (IMS), and top-down proteomics to gain additive structural information. Next, the use of in-cell FPOP (IC-FPOP) as a tool for proteome wide structural biology (PWSB) was expanded to characterize drug interactions in cells. First, IC-FPOP was used to highlight the differing effect of Gleevec in triple negative breast cancer (TNBC) for a European ancestry (TNBC-EA) and African ancestry (TNBC-AA) cell line. Finally, IC-FPOP efficacy in probing methotrexate’s effects in a chronic myelogenous leukemia (CML) was compared to cellular thermal shift assay (CETSA). CETSA is a recognized method that can be used to track drug interactions across the full proteome. However, there are some limitations to using CETSA which IC-FPOP can help overcome thus improving the characterization of drug interactions in cells.
    • Determining the infectious potential of individuals with positive RT-PCR SARS-CoV-2 tests

      Doshi, Peter; Powers, John H (Oxford University Press, 2020-12-04)
    • Antibiotics Approved for Marketing in Populations Specifically Excluded From Premarketing Trials, 1999-2018

      Kuzucan, Aida; Powers, John H; Doshi, Peter
      Approval by the US Food and Drug Administration (FDA) of a drug for a given indication is thought to reassure clinicians, other health care providers, and patients that substantial evidence of effectiveness exists for specific indicated populations (patients and diseases). This study examines whether FDA approval of certain antibiotics should be so reassuring for all patient populations identified in the FDA-approved labels. Specifically, this study compared patient populations covered by FDA-approved labels for 21 novel antibiotics approved between 1999 and 2018 to the patient exclusion and inclusion criteria of pivotal trials that supported those approvals. We found that every FDA-approved label for these antibiotics included at least one identifiable patient population that was explicitly excluded from enrolling in the supporting pivotal trials. Two antibiotics, bedaquiline and ceftazidime-avibactam, were approved for use in populations that were fully excluded from enrolling in registration trials.
    • Incompletely Reported Important Methodological Details and Inaccurate Description of the Formulation That the Control Arms Received in a Gardasil Vaccine Trial

      Bourgeois, Florence; Doshi, Peter; Hong, Kyungwan; Jefferson, Tom; Jones, Mark; Lee, Haeyoung; Rowhani-Farid, Anisa; Shamseer, Larissa; Spence, O'Mareen (American Society for Microbiology, 2020-11-04)
    • Covid-19 vaccine trial protocols released

      Doshi, Peter (BMJ Publishing Group, 2020-10-21)
    • Maryland Poison Center Annual Report 2019

      University of Maryland, Baltimore. Maryland Poison Center, 2019
    • Comparative effectiveness of pediatric and neonatal antimicrobial stewardship treatment algorithms in rapid diagnostic-detected bacteremia

      Kruger Howard, Amy; Claeys, Kimberly; Parbuoni, Kristine A.; Biggs, Jessica M.; Johnson, J. Kristie; Luneburg, Paige; Campbell, James D.; Morgan, Jill A. (2020-04)
    • Acceptance of medication - sweetness wins again

      Kruger Howard, Amy; Morgan, Jill A.; Selen, Arzu; Seung, Hyunuk; Ibrahim, Ahmed; Sayeed, Vilayat; Siddiqui, Akhtar; Hollenbeck, R. Gary; Hoag, Stephen W. (2019-09)
    • Impact of pharmacist patient education on asthma control

      Kruger Howard, Amy; Tsoukleris, Mona; Morgan, Jill A.; Seung, Hyunuk (2018-03)