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Full-Text Articles in Medicine and Health Sciences

Nursing: The Career That Saves Lives [Career Paper], Maggie Flanagan Dec 2015

Nursing: The Career That Saves Lives [Career Paper], Maggie Flanagan

Undergraduate Research Award

No abstract provided.


Yeast Vacuolar Hops, Regulated By Its Kinase, Exploits Affinities For Acidic Lipids And Rab:Gtp For Membrane Binding And To Catalyze Tethering And Fusion, Amy Orr, William Wickner, Scott F. Rusin, Arminja N. Kettenbach, Michael Zick Nov 2015

Yeast Vacuolar Hops, Regulated By Its Kinase, Exploits Affinities For Acidic Lipids And Rab:Gtp For Membrane Binding And To Catalyze Tethering And Fusion, Amy Orr, William Wickner, Scott F. Rusin, Arminja N. Kettenbach, Michael Zick

Dartmouth Scholarship

Fusion of yeast vacuoles requires the Rab GTPase Ypt7p, four SNAREs (soluble N-ethylmaleimide–sensitive factor attachment protein receptors), the SNARE disassembly chaperones Sec17p/Sec18p, vacuolar lipids, and the Rab-effector complex HOPS (homotypic fusion and vacuole protein sorting). Two HOPS subunits have direct affinity for Ypt7p. Although vacuolar fusion has been reconstituted with purified components, the functional relationships between individual lipids and Ypt7p:GTP have remained unclear. We now report that acidic lipids function with Ypt7p as coreceptors for HOPS, supporting membrane tethering and fusion. After phosphorylation by the vacuolar kinase Yck3p, phospho-HOPS needs both Ypt7p:GTP and acidic lipids to support fusion.


Links Between Anr And Quorum Sensing In Pseudomonas Aeruginosa Biofilms, John H. Hammond, Emily F. Dolben, T. Jarrod Smith, Sabin Bhuju, Deborah Hogan Jun 2015

Links Between Anr And Quorum Sensing In Pseudomonas Aeruginosa Biofilms, John H. Hammond, Emily F. Dolben, T. Jarrod Smith, Sabin Bhuju, Deborah Hogan

Dartmouth Scholarship

In Pseudomonas aeruginosa, the transcription factor Anr controls the cellular response to low oxygen or anoxia. Anr activity is high in oxygen-limited environments, including biofilms and populations associated with chronic infections, and Anr is necessary for persistence in a model of pulmonary infection. In this study, we characterized the Anr regulon in biofilm-grown cells at 1% oxygen in the laboratory strain PAO1 and in a quorum sensing (QS)-deficient clinical isolate, J215. As expected, transcripts related to denitrification, arginine fermentation, high-affinity cytochrome oxidases, and CupA fimbriae were lower in the Δanr derivatives. In addition, we observed that transcripts associated with quorum …


Sec17 Can Trigger Fusion Of Trans-Snare Paired Membranes Without Sec18, Michael Zick, Amy Orr, Matthew L. Schwartz, Alexey J. Merz, William Wickner Apr 2015

Sec17 Can Trigger Fusion Of Trans-Snare Paired Membranes Without Sec18, Michael Zick, Amy Orr, Matthew L. Schwartz, Alexey J. Merz, William Wickner

Dartmouth Scholarship

Sec17 [soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein; α-SNAP] and Sec18 (NSF) perform ATP-dependent disassembly of cis-SNARE complexes, liberating SNAREs for subsequent assembly of trans-complexes for fusion. A mutant of Sec17, with limited ability to stimulate Sec18, still strongly enhanced fusion when ample Sec18 was supplied, suggesting that Sec17 has additional functions. We used fusion reactions where the four SNAREs were initially separate, thus requiring no disassembly by Sec18. With proteoliposomes bearing asymmetrically disposed SNAREs, tethering and trans-SNARE pairing allowed slow fusion. Addition of Sec17 did not affect the levels of trans-SNARE complex but triggered sudden fusion of trans-SNARE paired proteoliposomes. …


Antibody-Mediated Targeting Of Iron Oxide Nanoparticles To The Folate Receptor Alpha Increases Tumor Cell Association In Vitro And In Vivo, Christian Ndong, Seiko Toraya-Brown, Katsiaryna Kekalo, Ian Baker, Tillman U. Gerngross, Steven N. Fiering, Karl E. Griswold Apr 2015

Antibody-Mediated Targeting Of Iron Oxide Nanoparticles To The Folate Receptor Alpha Increases Tumor Cell Association In Vitro And In Vivo, Christian Ndong, Seiko Toraya-Brown, Katsiaryna Kekalo, Ian Baker, Tillman U. Gerngross, Steven N. Fiering, Karl E. Griswold

Dartmouth Scholarship

Active molecular targeting has become an important aspect of nanoparticle development for oncology indications. Here, we describe molecular targeting of iron oxide nanoparticles (IONPs) to the folate receptor alpha (FOLRα) using an engineered antibody fragment (Ffab). Compared to control nanoparticles targeting the non-relevant botulinum toxin, the Ffab-IONP constructs selectively accumulated on FOLRα-overexpressing cancer cells in vitro, where they exhibited the capacity to internalize into intracellular vesicles. Similarly, Ffab-IONPs homed to FOLRα-positive tumors upon intraperitoneal administration in an orthotopic murine xenograft model of ovarian cancer, whereas negative control particles showed no detectable tumor accumulation. Interestingly, Ffab-IONPs built with custom 120 nm …


Binding-Induced, Turn-On Fluorescence Of The Egfr/Erbb Kinase Inhibitor, Lapatinib, James N. Wilson Mar 2015

Binding-Induced, Turn-On Fluorescence Of The Egfr/Erbb Kinase Inhibitor, Lapatinib, James N. Wilson

James N Wilson

We report the photophysical properties, binding-induced turn-on emission, and fluorescence imaging of the cellular uptake and distribution of lapatinib, an EGFR/ERBB inhibitor. Lapatinib, a type II, i.e. inactive state, inhibitor that targets the ATP binding pocket of the EGFR family of receptor tyrosine kinases. DFT calculations predict that the 6-furanylquinazoline core of lapatinib should exhibit an excited state with charge transfer character and an S0 to S1 transition energy of 3.4 eV. Absorption confirms an optical tran- sition in the near UV to violet, while fluorescence spectroscopy shows that photoemission is highly sensi- tive to solvent polarity. The hydrophobicity of …


Identification Of A Family Of Fatty Acid-Speciated Sonic Hedgehog Proteins, Whose Members Display Differential Biological Properties, Jun Long, Robert Tokhunts, William M. Old, Stephane Houel, Jezabel Rodgriguez-Blanco, Samer Singh, Neal Schilling, Anthony J. Capobianco, Natalie G. Ahn, David J. Robbins Mar 2015

Identification Of A Family Of Fatty Acid-Speciated Sonic Hedgehog Proteins, Whose Members Display Differential Biological Properties, Jun Long, Robert Tokhunts, William M. Old, Stephane Houel, Jezabel Rodgriguez-Blanco, Samer Singh, Neal Schilling, Anthony J. Capobianco, Natalie G. Ahn, David J. Robbins

Dartmouth Scholarship

Hedgehog (HH) proteins are proteolytically processed into a biologically active form that is covalently modified by cholesterol and palmitate. However, most studies of HH biogenesis have characterized protein from cells in which HH is overexpressed. We purified Sonic Hedgehog (SHH) from cells expressing physiologically relevant levels and showed that it was more potent than SHH isolated from overexpressing cells. Furthermore, the SHH in our preparations was modified with a diverse spectrum of fatty acids on its amino termini, and this spectrum of fatty acids varied dramatically depending on the growth conditions of the cells. The fatty acid composition of SHH …


Preliminary Investigations Into Triazole Derived Androgen Receptor Antagonists, Jarrad Altimari, Birunthi Niranjan, Gail Risbridger, Stephanie Schweiker, Anna Lohning, Luke Henderson Feb 2015

Preliminary Investigations Into Triazole Derived Androgen Receptor Antagonists, Jarrad Altimari, Birunthi Niranjan, Gail Risbridger, Stephanie Schweiker, Anna Lohning, Luke Henderson

Anna Lohning

A range of 1,4-substituted-1,2,3-N-phenyltriazoles were synthesized and evaluated as non-steroidal androgen receptor (AR) antagonists. The motivation for this study was to replace the N-phenyl amide portion of small molecule antiandrogens with a 1,2,3-triazole and determine effects, if any, on biological activity. The synthetic methodology presented herein is robust, high yielding and extremely rapid. Using this methodology a series of 17 N-aryl triazoles were synthesized from commercially available starting materials in less than 3 h. After preliminary biological screening at 20 and 40 lM, the most promising three compounds were found to display IC50 values of 40–50 lM against androgen dependent …


Science Classics, Mark Masthay Feb 2015

Science Classics, Mark Masthay

Mark Masthay

An essay on the impact of the works in the Imprints and Impressions: Milestones in Human Progress, an exhibition of rare books from the collection of Stuart Rose. Exhibition was held Sept. 29-Nov. 9, 2014, at the University of Dayton.


Fungal Mediator Tail Subunits Contain Classical Transcriptional Activation Domains, Zhongle Liu, Lawrence C. Myers Feb 2015

Fungal Mediator Tail Subunits Contain Classical Transcriptional Activation Domains, Zhongle Liu, Lawrence C. Myers

Dartmouth Scholarship

Classical activation domains within DNA-bound eukaryotic transcription factors make weak interactions with coactivator complexes, such as Mediator, to stimulate transcription. How these interactions stimulate transcription, however, is unknown. The activation of reporter genes by artificial fusion of Mediator subunits to DNA binding domains that bind to their promoters has been cited as evidence that the primary role of activators is simply to recruit Mediator. We have identified potent classical transcriptional activation domains in the C termini of several tail module subunits of Saccharomyces cerevisiae, Candida albicans, and Candida dubliniensis Mediator, while their N-terminal domains are necessary and sufficient for their …


Synthesis And Evaluation Of Substituted Coumarin Derivatives As Inhibitors Of Monoamine Oxidase B, Ian A. Kieffer Jan 2015

Synthesis And Evaluation Of Substituted Coumarin Derivatives As Inhibitors Of Monoamine Oxidase B, Ian A. Kieffer

Chemistry Theses

Monoamine oxidase B (MAO B) is of clinical importance due to its perceived role in neurodegenerative diseases such as Parkinson’s, making inhibitors of MAO B popular candidates for drug design. A series of coumarin derivatives have been prepared and assayed, revealing that the synthesized inhibitors act through a competitive mode of inhibition. In addition, these inhibitors are potent with Ki values in the nanomolar range. Overall, substitution at the 3- position of the coumarin was found to be important to inhibitor potency and further study of 3-aryl coumarin substitution computationally led to the prediction of 3-(3-aminophenyl)-6-hydroxycoumarin as a lead compound …