Digital Commons Network^™

Long-Distance Delivery Of Bacterial Virulence Factors By Pseudomonas Aeruginosa Outer Membrane Vesicles, Jennifer M. Bomberger, Daniel P. Maceachran, Bonita A. Coutermarsh, Siying Ye, George A. O'Toole, Bruce A. Stanton, Frederick M. Ausubel

Dartmouth Scholarship

Bacteria use a variety of secreted virulence factors to manipulate host cells, thereby causing significant morbidity and mortality. We report a mechanism for the long-distance delivery of multiple bacterial virulence factors, simultaneously and directly into the host cell cytoplasm, thus obviating the need for direct interaction of the pathogen with the host cell to cause cytotoxicity. We show that outer membrane–derived vesicles (OMV) secreted by the opportunistic human pathogen Pseudomonas aeruginosa deliver multiple virulence factors, including β-lactamase, alkaline phosphatase, hemolytic phospholipase C, and Cif, directly into the host cytoplasm via fusion of OMV with lipid rafts in the host plasma …

Borrelia Burgdorferi Ebfc Defines A Newly-Identified, Widespread Family Of Bacterial Dna-Binding Proteins, Sean P. Riley, Tomasz Bykowski, Anne E. Cooley, Logan H. Burns, Kelly Babb, Catherine A. Brissette, Amy Bowman, Matthew L. Rotondi, M. Clarke Miller, Edward Demoll, Kap Lim, Michael G. Fried, Brian Stevenson

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The Lyme disease spirochete, Borrelia burgdorferi, encodes a novel type of DNA-binding protein named EbfC. Orthologs of EbfC are encoded by a wide range of bacterial species, so characterization of the borrelial protein has implications that span the eubacterial kingdom. The present work defines the DNA sequence required for high-affinity binding by EbfC to be the 4 bp broken palindrome GTnAC, where ‘n’ can be any nucleotide. Two high-affinity EbfC-binding sites are located immediately 5′ of B. burgdorferi erp transcriptional promoters, and binding of EbfC was found to alter the conformation of erp promoter DNA. Consensus EbfC-binding …

Comparison Of Replication-Competent, First Generation, And Helper-Dependent Adenoviral Vaccines, Eric A. Weaver, Pramod N. Nehete, Stephanie S. Buchl, Julien S. Senac, Donna Palmer, Philip Ng, K. Jagannadha Sastry, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

All studies using human serotype 5 Adenovirus (Ad) vectors must address two major obstacles: safety and the presence of pre-existing neutralizing antibodies. Helper-Dependent (HD) Ads have been proposed as alternative vectors for gene therapy and vaccine development because they have an improved safety profile. To evaluate the potential of HD-Ad vaccines, we compared replication-competent (RC), first-generation (FG) and HD vectors for their ability to induce immune responses in mice. We show that RC-Ad5 and HD-Ad5 vectors generate stronger immune responses than FG-Ad5 vectors. HD-Ad5 vectors gave lower side effects than RC or FG-Ad, producing lower levels of tissue damage and …

Detection Of Cwd Prions In Urine And Saliva Of Deer By Transgenic Mouse Bioassay, Nicholas J. Haley, Davis M. Seelig, Mark D. Zabel, Glenn C. Telling, Edward A. Hoover

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Chronic wasting disease (CWD) is a prion disease affecting captive and free-ranging cervids (e.g. deer, elk, and moose). The mechanisms of CWD transmission are poorly understood, though bodily fluids are thought to play an important role. Here we report the presence of infectious prions in the urine and saliva of deer with chronic wasting disease (CWD). Prion infectivity was detected by bioassay of concentrated, dialyzed urine and saliva in transgenic mice expressing the cervid PrP gene (Tg[CerPrP] mice). In addition, PrP(CWD) was detected in pooled and concentrated urine by protein misfolding cyclic amplification (PMCA). The concentration of abnormal prion protein …

Genetic Mapping Of Secretion And Functional Determinants Of The Vibrio Cholerae Tcpf Colonization Factor, Shelly J. Krebs, Thomas J. Kirn, Ronald K. Taylor

Dartmouth Scholarship

Colonization of the human small intestine by Vibrio cholerae requires the type IV toxin-coregulated pilus (TCP). TcpF, which is encoded within the tcp operon, is secreted from the bacterial cell by the TCP apparatus and is also essential for colonization. Bacteria lacking tcpF are deficient in colonization, and anti-TcpF antibodies are protective in the infant mouse cholera model. In order to elucidate the regions of the protein that are required for secretion through the TCP apparatus and for its function in colonization, random mutagenesis of tcpF was performed. Analysis of these mutants suggests that multiple regions throughout the protein influence …

Neuroadaptations In The Cellular And Postsynaptic Group 1 Metabotropic Glutamate Receptor Mglur5 And Homer Proteins Following Extinction Of Cocaine Self-Administration, M. Behnam Ghasemzadeh, Preethi Vasudevan, Christopher Mueller, Chad Seubert, John R. Mantsch

Biomedical Sciences Faculty Research and Publications

This study examined the role of group1 metabotropic glutamate receptor mGluR5 and associated postsynaptic scaffolding protein Homer1b/c in behavioral plasticity after three withdrawal treatments from cocaine self-administration. Rats self-administered cocaine or saline for 14 days followed by a withdrawal period during which rats underwent extinction training, remained in their home cages, or were placed in the self-administration chambers in the absence of extinction. Subsequently, the tissue level and distribution of proteins in the synaptosomal fraction associated with the postsynaptic density were examined. Cocaine self-administration followed by home cage exposure reduced the mGluR5 protein in nucleus accumbens (NA) shell and dorsolateral …

Y27632, A Rho-Activated Kinase Inhibitor, Normalizes Dysregulation In Alpha1-Adrenergic Receptor-Induced Contraction Of Lyon Hypertensive Rat Artery Smooth Muscle., Maria Regina Freitas, Masumi Eto, Jason A Kirkbride, Christa Schott, Jean Sassard, Jean-Claude Stoclet

Department of Molecular Physiology and Biophysics Faculty Papers

RhoA-activated kinase (ROK) is involved in the disorders of smooth muscle contraction found in hypertension model animals and patients. We examined whether the alpha1-adrenergic receptor agonist-induced ROK signal is perturbed in resistance small mesentery artery (SMA) of Lyon genetically hypertensive (LH) rats, using a ROK antagonist, Y27632. Smooth muscle strips of SMA and aorta were isolated from LH and Lyon normotensive (LN) rats. After Ca(2+)-depletion and pre-treatment with phenylephrine (PE), smooth muscle contraction was induced by serial additions of CaCl(2). In LH SMA Ca(2+) permeated cells to a lesser extent as compared with LN SMA, while CaCl(2)-induced contraction of LH …

Paracrine Sonic Hedgehog Signalling By Prostate Cancer Cells Induces Osteoblast Differentiation, Samantha M Zunich, Taneka Douglas, Maria Valdovinos, Tiffany Chang

Dartmouth Scholarship

Sonic hedgehog (Shh) and components of its signalling pathway have been identified in human prostate carcinoma and increased levels of their expression appear to correlate with disease progression and metastasis. The mechanism through which Shh signalling could promote metastasis in bone, the most common site for prostate carcinoma metastasis, has not yet been investigated. The present study determined the effect of Shh signalling between prostate cancer cells and pre-osteoblasts on osteoblast differentiation, a requisite process for new bone formation that characterizes prostate carcinoma metastasis.

Acetaminophen Prevents Aging-Associated Hyperglycemia In Aged Rats: Effect Of Aging-Associated Hyperactivation Of P38-Mapk And Erk1/2, Miaozong Wu, Devashish H. Desai, Sunil K. Kakarla, Anjaiah Katta, Satyanarayana Paturi, Anil K. Gutta, Kevin M. Rice, Ernest M. Walker Jr., Eric R. Blough

MIIR Faculty Research

Background

Aging-related hyperglycemia is associated with increased oxidative stress and diminished muscle glucose transporter-4 (Glut4) that may be regulated, at least in part, by the mitogen-activated protein kinases (MAPK).

Methods

To test the possibility that aging-related hyperglycemia can be prevented by pharmacological manipulation of MAPK hyperactivation, aged (27-month old) Fischer 344/NNiaHSD × Brown Norway/BiNia F1 (F344BN) rats were administered acetaminophen (30 mg/kg body weight/day) for 6 months in drinking water.

Results

Hepatic histopathology, serum aspartate aminotransferase and alanine aminotransferase analyses suggested that chronic acetaminophen did not cause hepatotoxicity. Compared with adult (6-month) and aged (27-month) rats, very aged rats (33-month) …

Arteriogenic Revascularization Does Not Induce Vascular Function Impairment, Matthew David Yocum

Master's Theses

Functional hyperemia and arteriolar vasodilation are impaired with chronic ischemia. We sought to examine the impact of chronic ischemia on collateral artery function. For this we used two hindlimb ischemia models to dissect the impact of different repair processes on collateral function. Ligation of the femoral artery increases shear stress in the muscular branch and results in outward remodeling and arteriogenesis. In contrast, resection of the femoral artery proximal to the muscular branch induces blood flow divergence and neutral remodeling along with expectedly greater hypoxia and inflammation. On day 14 after each surgery the diameter of the muscular branch was …

From Traumatic Brain Injury To Posttraumatic Epilepsy: What Animal Models Tell Us About The Process And Treatment Options, Asla Pitkänen, Riikka J. Immonen, Olli H.J. Gröhn, Irina Kharatishvili

Biomedicine and Animal Models in Research Collection

A large number of animal models of traumatic brain injury (TBI) are already available for studies on mechanisms and experimental treatments of TBI. Immediate and early seizures have been described in many of these models with focal or mixed type (both gray and white matter damage) injury. Recent long-term video-electroencephalography (EEG) monitoring studies have demonstrated that TBI produced by lateral fluid-percussion injury in rats results in the development of late seizures, that is, epilepsy. These animals develop hippocampal alterations that are well described in status epilepticus–induced spontaneous seizure models and human posttraumatic epilepsy (PTE). In addition, these rats have damage …

Age-Related Differences In Reaction Time Task Performance In Young Children, Sergey Kiselev, Kimberly A. Espy, Tiffany Sheffield

Developmental Cognitive Neuroscience Laboratory: Faculty Publications

Performance of reaction time (RT) tasks was investigated in young children and adults to test the hypothesis that age-related differences in processing speed supersede a “global” mechanism and are a function of specific differences in task demands and processing requirements. The sample consisted of 54 4-year-olds, 53 5-year-olds, 59 6-year-olds, and 35 adults from Russia. Using the regression approach pioneered by Brinley and the transformation method proposed by Madden and colleagues and Ridderinkhoff and van der Molen, age-related differences in processing speed differed among RT tasks with varying demands. In particular, RTs differed between children and adults on tasks that …

Leptospira Interrogans Induces Apoptosis In Macrophages Via Caspase-8- And -3-Dependent Pathways, Dandan Jin, David M. Ojcius, Dexter Sun, Haiyan Dong, Yihui Luo, Yafei Mao, Jie Yan

All Dugoni School of Dentistry Faculty Articles

Apoptosis of host cells plays an important role in modulating the pathogenesis of many infectious diseases. It has been reported that Leptospira interrogans, the causal agent of leptospirosis, induces apoptosis in macrophages and hepatocytes. However, the molecular mechanisms responsible for host cell death remained largely unknown. Here we demonstrate that L. interrogans induced apoptosis in a macrophage-like cell line, J774A.1, and primary murine macrophages in a time- and dose-dependent manner. Apoptosis was associated with the activation of cysteine aspartic acid-specific proteases (caspase-3, caspase-6, and caspase-8), the increased expression of Fas-associated death domain (FADD), and the cleavage of the caspase substrates …

Naloxone's Pentapeptide Binding Site On Filamin A Blocks Mu Opioid Receptor–Gs Coupling And Creb Activation Of Acute Morphine, Hoau-Yan Wang, Lindsay H. Burns

Publications and Research

Chronic morphine causes the mu opioid receptor (MOR) to switch its coupling from Gi/o to Gs, resulting in excitatory signaling via both Gαs and its Gβγ dimer. Ultra-low-dose naloxone (NLX) prevents this switch and attenuates opioid tolerance and dependence. This protective effect is mediated via a high-affinity interaction of NLX to a pentapeptide region in c-terminal filamin A (FLNA), a scaffolding protein interacting with MOR. In organotypic striatal slice cultures, we now show that acute morphine induces a dose-dependent Go-to-Gs coupling switch at 5 and 15 min that resolves by 1 hr. The acute Gs coupling induced by 100 µM …

Apoptotic Engulfment Pathway And Schizophrenia, Xiangning Chen, Cuie Sun, Qi Chen, F. Anthony O'Neill, Dermot Walsh, Ayman H. Fanous, Kodavali V. Chowdari, Vishwajit L. Nimgaonkar, Adrian Scott, Sibylle G. Schwab, Dieter B. Wildenauer, Ronglin Che, Wei Tang, Yongyong Shi, Lin He, Xiong-Jian Luo, Bing Su, Todd L. Edwards, Zhongming Zhao, Kenneth S. Kendler

Human and Molecular Genetics Publications

Background

Apoptosis has been speculated to be involved in schizophrenia. In a previously study, we reported the association of the MEGF10 gene with the disease. In this study, we followed the apoptotic engulfment pathway involving the MEGF10, GULP1, ABCA1 and ABCA7 genes and tested their association with the disease.

Methodology/Principal Findings

Ten, eleven and five SNPs were genotyped in the GULP1, ABCA1 and ABCA7 genes respectively for the ISHDSF and ICCSS samples. In all 3 genes, we observed nominally significant associations. Rs2004888 at GULP1 was significant in both ISHDSF and ICCSS samples (p = 0.0083 and …

Effect Of Growth Hormone On Hippocampal Synaptic Function During Sleep Deprivation, Eun Young Kim

Theses, Dissertations and Capstones

Long term potentiation (LTP) in the hippocampus is considered a cellular basis of learning memory. Sleep deprivation, especially rapid eye movement (REM) sleep deprivation, impairs learning and memory as well as LTP. Since most of the previous LTP studies were conducted in the in vitro condition, the full consequences of sleep deprivation (SD) in the living animal are yet to be found. Thus, I tested hippocampal LTP in living animals after 5 days of REM sleep deprivation to determine the effect of SD in vivo. SD also disrupts growth hormone (GH) release. Recent evidence indicates that GH regulates cognitive and …

Loss Of Ski Expression In Testicular Cancer Leads To An Enhanced Invasive Phenotype Through Both Bmp-Dependent And Bmp-Independent Pathways, Amy N. Nash

Theses, Dissertations and Capstones

The proto-oncogene SKI is a transcription factor and a co-repressor of the TGFβ superfamily, including TGF

β and BMP. However, additional data suggests that SKI may function as a tumor suppressor in some cell types. The TGFβ superfamily has been implicated in cancer progression and germ cell migration. Testicular cancer afflicts men during their peak reproductive years and is the most common cancer among men of this age group. Cisplatin-based chemotherapy is the standard treatment for testicular cancer. This treatment can lead to undesirable side effects, including infertility. We have shown that SKI expression is decreased in testicular germ cell …

Effects Of Microgravity On Cancer Stem Cells Cultured In A Nasa Developed Bioreactor: Chemotherapeutic Implications., Sarah Elizabeth Daron Kelly

Theses, Dissertations and Capstones

The purpose of this study was to investigate the effects of simulated microgravity on cancer cell growth. Simulated microgravity is a condition in which cells are in constant free-fall and in which they are able to grow suspended without the shear and stress. Microgravity allows for important insights into the cellular mechanism and may be key in understanding why some cells thrive in this condition and others go into apoptosis. Cancer stem cells (CSCs) are considered a subset of the bulk tumor responsible for initiating and maintaining cancer. SAOS-2 is a human bone cancer cell line which consists of a …

Deferasirox Decreases Age-Associated Iron Accumulation In The Aging F344bn Rat Heart, Ravi K. Arvapalli

Theses, Dissertations and Capstones

It is thought that aging in rats and humans is associated with increases in iron accumulation and these increases in iron may be associated with increased cellular apoptosis. Here we examine the relationship between cardiac iron levels and cardiomyocyte apoptosis in aged F344BN rats which were treated with an oral iron chelator (Deferasirox; 100mg/kg body. weight/day) for 6 months. Compared with 6- month controls, the levels of cardiac iron, cardiac apoptosis, FLC and DMT-1 were higher in 33-month hearts. Deferasirox treatment for six months decreased cardiac iron and this was associated with decreases in the number of apoptotic cardiac myocytes. …

Fusion, 2009, George Washington University, William H. Beaumont Medical Research Honor Society

Fusion

No abstract provided.

Group Feeding For The Lactating Cow, Anthony Joseph Martin

Dairy Science

Feeding individualized rations for lactating dairy cattle in the commercial herd based on dietary needs is a popular issue. This has been a debating topic since evolution of the Total Mixed Ration (TMR). Since dairymen were able to mix grain in a feed wagon and mix a specific dietary ration to meet the demand for an organized group, there has been an issue in which protocol cow pen grouping should take. Dairymen have always feed cattle based on if lactating or late in their gestation, nonlactating. With the evolution of the TMR dairymen are then allowed to go into more …

Saving Lives And Changing Family Histories: Appropriate Counseling Of Pregnant Women And Men And Women Of Reproductive Age, Concerning The Risk Of Radiation Exposures During And Before Pregnancy, Robert L. Brent

The Selected Works of Robert Brent

No abstract provided.

Apd2: The Updated Antimicrobial Peptide Database And Its Application In Peptide Design., Guangshun Wang, Xia Li, Zhe Wang

Journal Articles: Pathology and Microbiology

The antimicrobial peptide database (APD, http://aps.unmc.edu/AP/main.php) has been updated and expanded. It now hosts 1228 entries with 65 anticancer, 76 antiviral (53 anti-HIV), 327 antifungal and 944 antibacterial peptides. The second version of our database (APD2) allows users to search peptide families (e.g. bacteriocins, cyclotides, or defensins), peptide sources (e.g. fish, frogs or chicken), post-translationally modified peptides (e.g. amidation, oxidation, lipidation, glycosylation or d-amino acids), and peptide binding targets (e.g. membranes, proteins, DNA/RNA, LPS or sugars). Statistical analyses reveal that the frequently used amino acid residues (>10%) are Ala and Gly in bacterial peptides, Cys and Gly in plant …

Efficacy Of Deferasirox In Preventing Complications Of Iron Overload In The Iron Overloaded Gerbil, Rabaa M. Al-Rousan

Theses, Dissertations and Capstones

Iron overload is a significant, world-wide problem that results in several chronic diseases including cardiovascular, hepatic and pancreatic complications.The newly developed, orally effective, iron chelating agent deferasirox is thought to offer tremendous promise as an alternative to deferoxamine. However, the efficacy and safety profile of deferasirox is not yet clear. In the present study, the efficacy of deferasirox in removing iron from target tissues has been examined using the gerbil model of iron overload. Deferasirox administration resulted in a significant reduction of iron from cardiac and hepatic tissue. In addition deferasirox reduced iron induced increase in cardiac and hepatic oxidative …

Urinary Levoglucosan As A Biomarker Of Wood Smoke Exposure: Observations In A Mouse Model And In Children, Christopher T. Migliaccio, M. A. Bergauff, Christopher P. Palmer, Forrest Jessop, Curtis W. Noonan, Tony Ward

Biomedical and Pharmaceutical Sciences Faculty Publications

BACKGROUND: Biomass smoke is an important source of particulate matter (PM), and much remains to be discovered with respect to the human health effects associated with this specific PM source. Exposure to biomass smoke can occur in one of two main categories: short-term exposures consist of periodic, seasonal exposures typified by communities near forest fires or intentional agricultural burning, and long-term exposures are chronic and typified by the use of biomass materials for cooking or heating. Levoglucosan (LG), a sugar anhydride released by combustion of cellulose-containing materials, is an attractive candidate as a biomarker of wood smoke exposure. OBJECTIVES: In …

Light-Induced Fos Expression In Intrinsically Photosensitive Retinal Ganglion Cells In Melanopsin Knockout (Opn4-/-) Mice, Gary E. Pickard, Scott B. Baver, Malcolm D. Ogilvie, Patricia J. Sollars

School of Veterinary and Biomedical Sciences: Faculty Publications

Retinal ganglion cells that express the photopigment melanopsin are intrinsically photosensitive (ipRGCs) and exhibit robust synaptically driven ON-responses to light, yet they will continue to depolarize in response to light when all synaptic input from rod and cone photoreceptors is removed. The light-evoked increase in firing of classical ganglion cells is determined by synaptic input from ON-bipolar cells in the proximal sublamina of the inner plexiform layer. OFF-bipolar cells synapse with ganglion cell dendrites in the distal sublamina of the inner plexiform layer. Of the several types of ipRGC that have been described, M1 ipRGCs send dendrites exclusively into the …

Power Of Models In Longitudinal Study: Findings From A Full- Crossed Simulation Design, Hua Fang, Gordon P. Brooks, Maria L. Rizzo, Kimberly A. Espy, Robert S. Barcikowski

Developmental Cognitive Neuroscience Laboratory: Faculty Publications

Because the power properties of traditional repeated measures and hierarchical multivariate linear models have not been clearly determined in the balanced design for longitudinal studies in the literature, the authors present a power comparison study of traditional repeated measures and hierarchical multivariate linear models under 3 variance-covariance structures. The results from a full-crossed simulation design suggest that traditional repeated measures have significantly higher power than do hierarchical multivariate linear models for main effects, but they have significantly lower power for interaction effects in most situations. Significant power differences are also exhibited when power is compared across different covariance structures.

Synchronization Of Pancreatic Islet Oscillations By Intrapancreatic Ganglia: A Modeling Study, B. Fendler, M. Zhang, L. Satin, R. Bertram

Pharmacology and Toxicology Publications

Abstract

Plasma insulin measurements from mice, rats, dogs, and humans indicate that insulin levels are oscillatory, reflecting pulsatile insulin secretion from individual islets. An unanswered question, however, is how the activity of a population of islets is coordinated to yield coherent oscillations in plasma insulin. Here, using mathematical modeling, we investigate the feasibility of a potential islet synchronization mechanism, cholinergic signaling. This hypothesis is based on well-established experimental evidence demonstrating intrapancreatic parasympathetic (cholinergic) ganglia and recent in vitro evidence that a brief application of a muscarinic agonist can transiently synchronize islets. We demonstrate using mathematical modeling that periodic pulses of …

Reduced Genomic Potential For Secreted Plant Cell-Wall-Degrading Enzymes In The Ectomycorrhizal Fungus Amanita Bisporigera, Based On The Secretome Of Trichoderma Reesei, Subashini Nagendran, Heather E. Hallen-Adams, Janet M. Paper, Nighat Aslam, Jonathan D. Walton

Heather Hallen-Adams Publications

Based on the analysis of its genome sequence, the ectomycorrhizal (ECM) basidiomycetous fungus Laccaria bicolor was shown to be lacking many of the major classes of secreted enzymes that depolymerize plant cell wall polysaccharides. To test whether this is also a feature of other ECM fungi, we searched a survey genome database of Amanita bisporigera with the proteins found in the secretome of Trichoderma reesei (syn. Hypocrea jecorina), a biochemically well-characterized industrial fungus. Additional proteins were also used as queries to compensate for major groups of cell-wall-degrading enzymes lacking in the secretome of T. reesei and to substantiate conclusions …

Delayed Rejection Of Mhc Class Ii-Disparate Skin Allografts In Mice Treated With Farnesyltransferase Inhibitors, Ken Field

Faculty Journal Articles

Farnesyltransferase inhibitors (FTIs), developed as anti-cancer drugs, have the potential to modulate immune responses without causing nonspecific immune suppression. We have investigated the possibility that FTIs, by affecting T cell cytokine secretion, can attenuate alloreactive immune responses. The effects of FTIs on murine alloreactive T cells were determined both in vitro, by measuring cytokine secretion or cell proliferation in mixed lymphocyte cultures, and in vivo, by performing skin allografts from H-2^bm12mice to MHC class II-disparate B6 mice. We found that two different FTIs, ABT-100 and L-744,832, blocked secretion of IFN-γ, IL-2, IL-4, and TNF-α from naïve …