Life Sciences Commons^™

In-House Daily Consensus Conference: An Important Quality Control/Quality Assurance Activity--Experience At A Major Referral Center., Amna Khurshid, Zubair Ahmad, Asim Qureshi

Zubair Ahmad

Background:For every practicing histopathologist, improvement of diagnostic accuracy is an important objective. Personal consults are an important component of quality control (QC)/quality assurance (QA) in our Section of Histopathology. In addition, the College of American Pathologists recommends a daily in-house consensus conference, which is a prospective system by which all difficult and problematic cases are reviewed and discussed and signed out by consensus. Design: In-house consensus conference is held daily using a multi-headed microscope. This collegial session is run by the seniormost consultant in the section and is attended by all histopathology consultants and residents. The consultants and residents …

A Role For A Rab4-Like Gtpase In Endocytosis And In Regulation Of Contractile Vacuole Structure And Function In Dictyostelium Discoideum, John Bush, Lesly A. Temesvari, Juan Rodriguez-Paris, Greg Buczynski, James Cardelli

Lesly Temesvari

The small Mr Rab4-like GTPase, RabD, localizes to the endosomal pathway and the contractile vacuole membrane system in Dictyostelium discoideum. Stably transformed cell lines overexpressing a dominant negative functioning RabD internalized fluid phase marker at 50% of the rate of wild-type cells. Mutant cells were also slower at recycling internalized fluid. Microscopic and biochemical approaches indicated that the transport of fluid to large postlysosome vacuoles was delayed in mutant cells, resulting in an accumulation in acidic smaller vesicles, probably lysosomes. Also, RabD N121I-expressing cell lines missorted a small but significant percentage of newly synthesized lysosomal alpha-mannosidase precursor polypeptides. However, the …

Nitrogen Fertilization Has A Stronger Effect On Soil Nitrogen-Fixing Bacterial Communities Than Elevated Atmospheric Co2, Sean Berthrong, Chris Yeager, Laverne Gallegos-Graves, Blaire Steven, Stephanie Eichorst, Robert Jackson, Cheryl Kuske

Sean Berthrong

Biological nitrogen fixation is the primary supply of N to most ecosystems, yet there is considerable uncertainty about how N-fixing bacteria will respond to global change factors such as increasing atmospheric CO2 and N deposition. Using the nifH gene as a molecular marker, we studied how the community structure of N-fixing soil bacteria from temperate pine, aspen, and sweet gum stands and a brackish tidal marsh responded to multiyear elevated CO2 conditions. We also examined how N availability, specifically, N fertilization, interacted with elevated CO2 to affect these communities in the temperate pine forest. Based on data from Sanger sequencing …

Structure Of The Vif-Binding Domain Of The Antiviral Enzyme Apobec3g, Takahide Kouno, Elizabeth Luengas, Megumi Shigematsu, Shivender Shandilya, Jingying Zhang, Luan Chen, Mayuko Hara, Celia Schiffer, Reuben Harris, Hiroshi Matsuo

Celia A. Schiffer

The human APOBEC3G (A3G) DNA cytosine deaminase restricts and hypermutates DNA-based parasites including HIV-1. The viral infectivity factor (Vif) prevents restriction by triggering A3G degradation. Although the structure of the A3G catalytic domain is known, the structure of the N-terminal Vif-binding domain has proven more elusive. Here, we used evolution- and structure-guided mutagenesis to solubilize the Vif-binding domain of A3G, thus permitting structural determination by NMR spectroscopy. A smaller zinc-coordinating pocket and altered helical packing distinguish the structure from previous catalytic-domain structures and help to explain the reported inactivity of this domain. This soluble A3G N-terminal domain is bound by …

Simultaneously Targeting The Ns3 Protease And Helicase Activities For More Effective Hepatitis C Virus Therapy, Jean Ndjomou, M Corby, Noreena Sweeney, Alicia Hanson, Cihan Aydin, Akbar Ali, Celia Schiffer, Kelin Li, Kevin Frankowski, Frank Schoenen, David Frick

Celia A. Schiffer

This study examines the specificity and mechanism of action of a recently reported hepatitis C virus (HCV) nonstructural protein 3 (NS3) helicase-protease inhibitor (HPI), and the interaction of HPI with the NS3 protease inhibitors telaprevir, boceprevir, danoprevir, and grazoprevir. HPI most effectively reduced cellular levels of subgenomic genotype 4a replicons, followed by genotypes 3a and 1b replicons. HPI had no effect on HCV genotype 2a or dengue virus replicon levels. Resistance evolved more slowly to HPI than telaprevir, and HPI inhibited telaprevir-resistant replicons. Molecular modeling and analysis of the ability of HPI to inhibit peptide hydrolysis catalyzed by a variety …

Inhibition Of Apobec3g Activity Impedes Double-Stranded Dna Repair, Ponnandy Prabhu, Shivender Shandilya, Elena Britan-Rosich, Adi Nagler, Celia Schiffer, Moshe Kotler

Celia A. Schiffer

The cellular cytidine deaminase APOBEC3G (A3G) was first described as an anti-HIV-1 restriction factor, acting by directly deaminating reverse transcripts of the viral genome. HIV-1 Vif neutralizes the activity of A3G, primarily by mediating degradation of A3G to establish effective infection in host target cells. Lymphoma cells, which express high amounts of A3G, can restrict Vif-deficient HIV-1. Interestingly, these cells are more stable in the face of treatments that result in double-stranded DNA damage, such as ionizing radiation and chemotherapies. Previously, we showed that the Vif-derived peptide (Vif25-39) efficiently inhibits A3G deamination, and increases the sensitivity of lymphoma cells to …

Modulation Of Hiv Protease Flexibility By The T80n Mutation, Hao Zhou, Shangyang Li, John Badger, Ellen Nalivaika, Yufeng Cai, Jennifer Foulkes-Murzycki, Celia Schiffer, Lee Makowski

Celia A. Schiffer

The flexibility of HIV protease (HIVp) plays a critical role in enabling enzymatic activity and is required for substrate access to the active site. While the importance of flexibility in the flaps that cover the active site is well known, flexibility in other parts of the enzyme is also critical for function. One key region is a loop containing Thr 80, which forms the walls of the active site. Although not situated within the active site, amino acid Thr80 is absolutely conserved. The mutation T80N preserves the structure of the enzyme but catalytic activity is completely lost. To investigate the …

A Direct Interaction With Rna Dramatically Enhances The Catalytic Activity Of The Hiv-1 Protease In Vitro, Marc Potempa, Ellen Nalivaika, Debra Ragland, Sook-Kyung Lee, Celia Schiffer, Ronald Swanstrom

Celia A. Schiffer

Though the steps of human immunodeficiency virus type 1 (HIV-1) virion maturation are well documented, the mechanisms regulating the proteolysis of the Gag and Gag-Pro-Pol polyproteins by the HIV-1 protease (PR) remain obscure. One proposed mechanism argues that the maturation intermediate p15NC must interact with RNA for efficient cleavage by the PR. We investigated this phenomenon and found that processing of multiple substrates by the HIV-1 PR was enhanced in the presence of RNA. The acceleration of proteolysis occurred independently from the substrate's ability to interact with nucleic acid, indicating that a direct interaction between substrate and RNA is not …

A Balance Between Inhibitor Binding And Substrate Processing Confers Influenza Drug Resistance, Li Jiang, Ping Liu, Claudia Bank, Nicholas Renzette, Kristina Prachanronarong, L. Yilmaz, Daniel Caffrey, Konstantin Zeldovich, Celia Schiffer, Timothy Kowalik, Jeffrey Jensen, Robert Finberg, Jennifer Wang, Daniel Bolon

Celia A. Schiffer

The therapeutic benefits of the neuraminidase (NA) inhibitor oseltamivir are dampened by the emergence of drug resistance mutations in influenza A virus (IAV). To investigate the mechanistic features that underlie resistance, we developed an approach to quantify the effects of all possible single-nucleotide substitutions introduced into important regions of NA. We determined the experimental fitness effects of 450 nucleotide mutations encoding positions both surrounding the active site and at more distant sites in an N1 strain of IAV in the presence and absence of oseltamivir. NA mutations previously known to confer oseltamivir resistance in N1 strains, including H275Y and N295S, …

Structural And Thermodynamic Effects Of Macrocyclization In Hcv Ns3/4a Inhibitor Mk-5172, Djade Soumana, Nese Yilmaz, Kristina Prachanronarong, Cihan Aydin, Akbar Ali, Celia Schiffer

Celia A. Schiffer

Recent advances in direct-acting antivirals against Hepatitis C Virus (HCV) have led to the development of potent inhibitors, including MK-5172, that target the viral NS3/4A protease with relatively low susceptibility to resistance. MK-5172 has a P2-P4 macrocycle and a unique binding mode among current protease inhibitors where the P2 quinoxaline packs against the catalytic residues H57 and D81. However, the effect of macrocyclization on this binding mode is not clear, as is the relation between macrocyclization, thermodynamic stabilization, and susceptibility to the resistance mutation A156T. We have determined high-resolution crystal structures of linear and P1-P3 macrocyclic analogs of MK-5172 bound …

Improved Susceptibility Pattern Of Antimicrobials Using Vital Energy Treatment On Shigella Sonnei, Mahendra Kumar Trivedi, Alice Branton, Dahryn Trivedi, Gopal Nayak, Mayank Gangwar, Snehasis Jana

Mahendra Kumar Trivedi

In Vitro Evaluation Of Biofield Treatment On Viral Load Against Human Immunodeficiency-1 And Cytomegalo Viruses, Mahendra Kumar Trivedi, Alice Branton, Dahryn Trivedi, Gopal Nayak, Sambhu Charan Mondal, Snehasis Jana

Mahendra Kumar Trivedi

Antibiogram Of Multidrug-Resistant Isolates Of Pseudomonas Aeruginosa After Biofield Treatment, Mahendra Kumar Trivedi, Alice Branton, Dahryn Trivedi, Gopal Nayak, Mayank Gangwar, Snehasis Jana

Mahendra Kumar Trivedi

Investigation Of Biofield Treatment On Antimicrobial Susceptibility, Biochemical Reaction Pattern And Biotyping Of Enteropathogenic Multidrug-Resistant Escherichia Coli Isolates, Mahendra Kumar Trivedi, Alice Branton, Dahryn Trivedi, Gopal Nayak, Harish Shettigar, Mayank Gangwar, Snehasis Jana

Mahendra Kumar Trivedi

Effects Of Temperature, Nutrients, Organic Matter And Coral Mucus On The Survival Of The Coral Pathogen, Serratia Marcescens, Erin Looney, Kathryn Sutherland, Erin Lipp

Kathryn Patterson Sutherland PhD

Serratia marcescens is an enteric bacterium that causes white pox disease in elkhorn coral, Acropora palmata; however, it remains unclear if the pathogenic strain has adapted to seawater or if it requires a host or reservoir for survival. To begin to address this fundamental issue, the persistence of strain PDL100 was compared among seawater and coral mucus microcosms. Median survival time across all conditions ranged from a low of 15 h in natural seawater [with a first-order decay constant (k) = −0.173] at 30°C to a maximum of 120 h in glucose-amended A. palmata mucus (k = −0.029) at 30°C. …

Human Sewage Identified As Likely Source Of White Pox Disease Of The Threatened Caribbean Elkhorn Coral, Kathryn Sutherland, James Porter, Jeffrey Turner, Brian Thomas, Erin Looney, Trevor Luna, Meredith Meyers, J. Futch, Erin Lipp

Kathryn Patterson Sutherland PhD

Caribbean elkhorn coral, Acropora palmata, has been decimated in recent years, resulting in the listing of this species as threatened under the United States Endangered Species Act. A major contributing factor in the decline of this iconic species is white pox disease. In 2002, we identified the faecal enterobacterium, Serratia marcescens, as an etiological agent for white pox. During outbreaks in 2003 a unique strain of S. marcescens was identified in both human sewage and white pox lesions. This strain (PDR60) was also identified from corallivorious snails (Coralliophila abbreviata), reef water, and two non-acroporid coral species, Siderastrea siderea and Solenastrea …

North Atlantic Vibrio Vulnificus Surveillance From Postharvest Oysters At A Us Shellfish Processing Facility, Kenneth Lavalley, Joseph Dealteris, Michael Rice, Marta Gomez-Chiarri

Marta Gomez-Chiarri

Postharvest surveillance for Vibrio vulnificus by a commercial processing facility was conducted from May 2001 to September 2003. Harvest areas included the Delaware Bay, Long Island Sound and Prince Edward Island. Occurrence followed a seasonal distribution. Low densities were observed in June, increased through August, and became rare by September. Given the ubiquitous nature of marine Vibrios, it was not surprising to find V. vulnificus everywhere, which was investigated. Observations confirmed the importance of strict time/temperature and product handling practices by shellfish harvesters, dealers and processors. Mishandling led to a potentially dangerous and uncharacteristically high V. vulnificus observation.

Outer Membrane Protein P5 Is Required For Resistance Of Nontypeable Haemophilus Influenzae To Both The Classical And Alternative Complement Pathways., Charles Rosadini, Sanjay Ram, Brian Akerley

Brian J. Akerley

No abstract provided.

Bioinformatics Analyses Of Chromium Tolerant Genes In Cyanobacteria And Identification Of Their Operon In Synechococcus Sp. Iu 625, Lee Lee, Richard Garrett, Anna Slusarczyk, Jose Perez, Tin-Chun Chu

Tin-Chun Chu, Ph.D.

No abstract provided.

Transcriptional Regulation Of Sunscreen Biosynthesis In Cyanobacteria, Tanya Soule

Tanya Soule

No abstract provided.

Recombinant Expression Of Indolicidin Concatemers In Escherichia Coli, K Morin, S Arcidiacono, Richard Beckwitt, C Mello

Richard D Beckwitt

Antimicrobial peptides are part of the innate immune system of vertebrates and invertebrates. They are active against gram-negative and gram-positive bacteria, fungi, and protozoa. Currently, most antimicrobial peptides are extracted from host organisms or produced by solidphase peptide synthesis. Recombinant protein expression in Escherichia coli is a tool for greater production yields at a decreased cost and reduces the use of hazardous materials. We have constructed a concatamer of indolicidin and successfully expressed a fusion product with thioredoxin in E. coli BL21DE3. Codons for methionine residues flanking individual indolicidin genes were incorporated for cyanogen bromide cleavage of the fusion protein …

The Use Of Course Response Systems To Assess Student Learning In The Classroom, Tanya Soule, Jordan Marshall

Tanya Soule

No abstract provided.

Artemether-Lumefantrine Selects For Malaria Parasites With Decreased Lumefantrine Sensitivity Although Parasites Remain Sensitive To This Regimen In Tororo, Uganda, P. Tumwebaze, J. Bloome, O. Byaruhanga, C. Nakazibwe, A. Walakira, J. Okiring, S. L. Nsobya, Roland A. Cooper, P. J. Rosenthal

Roland A. Cooper

Inhibition Of Herpes Simplex Virus Type 1 With The Modified Green Tea Polyphenol Pamitoyl-Epigallocatechin Gallate., Aline De Oliveira, Sandra Adams, Lee Lee, Sean Murray, Stephen Hsu, Jeffrey Hammond, Douglas Dickinson, Ping Chen, Tin-Chun Chu

Tin-Chun Chu, Ph.D.

No abstract provided.

Epigallocatechin-3-Gallate Modulates Oxidative Stress In Exocrine Glands Of A Primary Sjogren’S Syndrome Mouse Model Prior To Disease Onset, Seiji Ohno, Hongfang Yu, Douglas Dickinson, Tin-Chun Chu, Kalu Ogbureke, Scott Derossi, Tetsuya Yamamoto, Stephen Hsu

Tin-Chun Chu, Ph.D.

No abstract provided.

Microbial Sunscreens: Opportunities And Obstacles, Tanya Soule

Tanya Soule

No abstract provided.

Accumulation Of Extracellular Carbohydrates In A Scytonemin-Deficient Mutant Of Nostoc Punctiforme Exposed To Uva Stress, Tanya Soule

Tanya Soule

No abstract provided.

Protamine-Like Proteins In 12 Sequenced Species Of Drosophila, Zain Alvi, Tin-Chun Chu, Valerie Schawaroch, Angela Klaus

Tin-Chun Chu, Ph.D.

No abstract provided.

Identification And Bioinformatic Analyses Of Vanillate Operon In Cyanobacterium Synechococcus Sp. Iu 625, Robert Newby, Tin-Chun Chu

Tin-Chun Chu, Ph.D.

No abstract provided.

Bioinformatic Analysis Of Cyanobacterial Mercuric Resistance Genes And Identification Of Synechococcus Sp. Iu 625 Putative Mercuric Resistance Genes, Lee Lee, Chiedozie Okafor, Matthew Rienzo, Tin-Chun Chu

Tin-Chun Chu, Ph.D.

No abstract provided.