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Acat1 Gene Ablation Increases 24(S)-Hydroxycholesterol Content In The Brain And Ameliorates Amyloid Pathology In Mice With Ad, Elena Y. Bryleva, Maximillian A. Rogers, Catherine C. Y. Chang, Floyd Buen

Dartmouth Scholarship

Cholesterol metabolism has been implicated in the pathogenesis of several neurodegenerative diseases, including the abnormal accumulation of amyloid-beta, one of the pathological hallmarks of Alzheimer disease (AD). Acyl-CoA:cholesterol acyltransferases (ACAT1 and ACAT2) are two enzymes that convert free cholesterol to cholesteryl esters. ACAT inhibitors have recently emerged as promising drug candidates for AD therapy. However, how ACAT inhibitors act in the brain has so far remained unclear. Here we show that ACAT1 is the major functional isoenzyme in the mouse brain. ACAT1 gene ablation (A1-) in triple transgenic (i.e., 3XTg-AD) mice leads to more than 60% reduction in full-length human …

Deficient Cd40-Traf6 Signaling In Leukocytes Prevents Atherosclerosis By Skewing The Immune Response Toward An Antiinflammatory Profile, Esther Lutgens, Dirk Lievens, Linda Beckers, Erwin Wijnands, Oliver Soehnlein, Alma Zernecke, Tom Seijkens, David Engel, Jack Cleutjens, Anna M. Keller, Shalin H. Naike, Louis Boon, Hafid Ait Oufella, Ziad Mallat, Cory L. Ahonen, Randolph J. Noelle, Menno P. De Winther, Mat J. Daemen, Erik A. Biessen, Christian Weber

Dartmouth Scholarship

The CD40–CD40 ligand (CD40L) signaling axis plays an important role in immunological pathways. Consequently, this dyad is involved in chronic inflammatory diseases, including atherosclerosis. Inhibition of CD40L in apolipoprotein E (Apoe)–deficient ( Apoe - / - ) mice not only reduced atherosclerosis but also conferred a clinically favorable plaque phenotype that was low in inflammation and high in fibrosis. Blockade of CD40L may not be therapeutically feasible, as long-term inhibition will compromise systemic immune responses. Conceivably, more targeted intervention strategies in CD40 signaling will have less deleterious side effects. We report that deficiency in hematopoietic CD40 reduces atherosclerosis and induces …

Algal Biofuel, Feb. 12, 2010, Harry Reid Center, University Of Nevada, Las Vegas

Biofuels

News in Brief

1. Fatty Acids Protect Against Aging (Feb. 8, 2010)

Recapitulating Osteoblastogenesis With Electrospun Fibrinogen Nanofibers And Adipose Stem Cells And Electrospinning Adipose Tissue-Derived Basement Membrane, Michael Francis

Theses and Dissertations

To repair, replace, or regenerate damaged or diseased tissue has been a long-standing, albeit elusive, goal in medical research. Here, we characterize patient-derivable mesenchymal stem cell types, termed adipose-derived stem cells (ASCs). These cells, which can be derived from liposuction fat and lipoaspirate saline, are sources for patient-derivable extracellular matrix (ECM), fibrinogen (Fg) and adipose tissue extracellular matrix, and may prove useful for synthesizing new bone tissue analogues in vitro. Traditionally and rapidly isolated ASCs were thoroughly characterized as multipotent, having osteogenic, adipogenic, and chondrogenic differentiation potential, and they exhibited comparable proliferative lifespans. These ASCs also shared an indistinguishable immunophenotype …

A Robust Gene Selection Method For Microarray-Based Cancer Classification., Xiaosheng Wang, Osamu Gotoh

Journal Articles: Genetics, Cell Biology & Anatomy

Gene selection is of vital importance in molecular classification of cancer using high-dimensional gene expression data. Because of the distinct characteristics inherent to specific cancerous gene expression profiles, developing flexible and robust feature selection methods is extremely crucial. We investigated the properties of one feature selection approach proposed in our previous work, which was the generalization of the feature selection method based on the depended degree of attribute in rough sets. We compared the feature selection method with the established methods: the depended degree, chi-square, information gain, Relief-F and symmetric uncertainty, and analyzed its properties through a series of classification …

Effects Of A Single Sickling Event On The Mechanical Fragility Of Sickle Cell Trait Erythrocytes, Tennille D. Presley, Andreas S. Perlegas, Lauren E. Bain, Samir K. Ballas, James S. Nichols, Hernan Sabio, Mark T. Gladwin, Gregory J. Kato, Dany B. Kim-Shapiro

Department of Medicine Faculty Papers

Hemolysis contributes to the pathology associated with sickle cell disease. However, the mechanism of hemolysis or relative contribution of sickling due to hemoglobin (Hb) polymerization vs. oxidative damage remains unknown. Earlier studies aimed at deciphering the relative importance of these two mechanisms have been complicated by the fact that sickle red cells (SS) have already been affected by multiple rounds of sickling and oxidative damage before they are collected. In our study, we examine the mechanical fragility of sickle cell trait cells, which do not sickle in vivo, but can be made to do so in vitro. Thus, our novel …

Porcine Reproductive And Respiratory Syndrome Virus Nonstructural Protein 1Β Modulates Host Innate Immune Response By Antagonizing Irf3 Activation, Lalit Beura, Saumendra Sarkar, Byungjoon Kwon, Sakthivel Subramaniam, Clinton J. Jones, Asit K. Pattnaik, Fernando A. Osorio

School of Veterinary and Biomedical Sciences: Faculty Publications

Porcine reproductive and respiratory syndrome virus (PRRSV) infection of swine leads to a serious disease characterized by a delayed and defective adaptive immune response. It is hypothesized that a suboptimal innate immune response is responsible for the disease pathogenesis. In the study presented here we tested this hypothesis and identified several nonstructural proteins (NSPs) with innate immune evasion properties encoded by the PRRS viral genome. Four of the total ten PRRSV NSPs tested were found to have strong to moderate inhibitory effects on beta interferon (IFN-β) promoter activation. The strongest inhibitory effect was exhibited by NSP1 followed by, NSP2, NSP11, …

The Minor Envelope Glycoproteins Gp2a And Gp4 Of Porcine Reproductive And Respiratory Syndrome Virus Interact With The Receptor Cd163, Phani B. Das, Phat X. Dinh, Israrul H. Ansari, Marcelo De Lima, Fernando A. Osorio, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

Porcine reproductive and respiratory syndrome virus (PRRSV) contains the major glycoprotein, GP5, as well as three other minor glycoproteins, namely, GP2a, GP3, and GP4, on the virion envelope, all of which are required for generation of infectious virions. To study their interactions with each other and with the cellular receptor for PRRSV, we have cloned each of the viral glycoproteins and CD163 receptor in expression vectors and examined their expression and interaction with each other in transfected cells by coimmunoprecipitation (co-IP) assay using monospecific antibodies. Our results show that a strong interaction exists between the GP4 and GP5 proteins, although …

Crystal Structure Of The Cystic Fibrosis Transmembrane Conductance Regulator Inhibitory Factor Cif Reveals Novel Active-Site Features Of An Epoxide Hydrolase Virulence Factor, Christopher D. Bahl, Christophe Morisseau, Jennifer M. Bomberger, Bruce A. Stanton, Bruce D. Hammock, George A. O'Toole, Dean R. Madden

Dartmouth Scholarship

Cystic fibrosis transmembrane conductance regulator (CFTR) inhibitory factor (Cif) is a virulence factor secreted by Pseudomonas aeruginosa that reduces the quantity of CFTR in the apical membrane of human airway epithelial cells. Initial sequence analysis suggested that Cif is an epoxide hydrolase (EH), but its sequence violates two strictly conserved EH motifs and also is compatible with other alpha/beta hydrolase family members with diverse substrate specificities. To investigate the mechanistic basis of Cif activity, we have determined its structure at 1.8-A resolution by X-ray crystallography. The catalytic triad consists of residues Asp129, His297, and Glu153, which are conserved across the …

Progressive Changes In Microglia And Macrophages In Spinal Cord And Peripheral Nerve In The Transgenic Rat Model Of Amyotrophic Lateral Sclerosis, David J. Graber, William F. Hickey, Brent T. Harris

Dartmouth Scholarship

The role of neuroinflammation in motor neuron death of amyotrophic lateral sclerosis (ALS) is unclear. The human mutant superoxide dismutase-1 (hmSOD1)-expressing murine transgenic model of ALS has provided some insight into changes in microglia activity during disease progression. The purpose of this study was to gain further knowledge by characterizing the immunological changes during disease progression in the spinal cord and peripheral nerve using the more recently developed hmSOD1 rat transgenic model of ALS. Using immunohistochemistry, the extent and intensity of tissue CD11b expression in spinal cord, lumbar nerve roots, and sciatic nerve were evaluated in hmSOD1 rats that were …

Regulation Of Telomerase Expression In Stem Cell Reprogramming, Patrick Sachs

Theses and Dissertations

A great need exists for an abundant, easily accessible source of patient-specific cells that will function for use in regenerative medicine. One promising source is the adult stem cell derived from adipose tissue (ASCs). Isolated from waste lipoaspiration, these cells could serve as a readily available source for the regeneration of damaged tissues. To further define the biology of ASCs, we have isolated multiple cell strains from different adipose tissue sources, indicating wide-spread distribution in the body. We find that a widely used set of cell surface markers fail to distinguish ASCs from normal fibroblasts. However, our ASC isolations are …

Bitc Sensitizes Pancreatic Adenocarcinomas To Trail-Induced Apoptosis, Christina A. Wicker, Ravi P. Sahu, Kashmira Kulkarni-Datar, Sanjay K. Srivastava, Thomas L. Brown

Neuroscience, Cell Biology & Physiology Faculty Publications

Pancreatic adenocarcinoma is an aggressive cancer with a greater than 95% mortality rate and short survival after diagnosis. Chemotherapeutic resistance hinders successful treatment. This resistance is often associated with mutations in codon 12 of the K-Ras gene (K-Ras 12), which is present in over 90% of all pancreatic adenocarcinomas. Codon 12 mutations maintain Ras in a constitutively active state leading to continuous cellular proliferation. Our study determined if TRAIL resistance in pancreatic adenocarcinomas with K-Ras 12 mutations could be overcome by first sensitizing the cells with Benzyl isothiocyanate (BITC). BITC is a component of cruciferous vegetables and a cell cycle …

Proliferation Of Aneuploid Human Cells Is Limited By A P53-Dependent Mechanism, Sarah L. Thompson, Duane A. Compton

Dartmouth Scholarship

Most solid tumors are aneuploid, and it has been proposed that aneuploidy is the consequence of an elevated rate of chromosome missegregation in a process called chromosomal instability (CIN). However, the relationship of aneuploidy and CIN is unclear because the proliferation of cultured diploid cells is compromised by chromosome missegregation. The mechanism for this intolerance of nondiploid genomes is unknown. In this study, we show that in otherwise diploid human cells, chromosome missegregation causes a cell cycle delay with nuclear accumulation of the tumor suppressor p53 and the cyclin kinase inhibitor p21. Deletion of the p53 gene permits the accumulation …

Neural Network Model For Instruments That Store And Retrieve Sequential Information, Philip W. Landfield, Olivier Thibault

Pharmacology and Nutritional Sciences Faculty Patents

A method and design is provided for distributing and storing sets of temporally ordered information in a systematic and sequential fashion. This method is based on a model of how the brain functions in the distribution and storage of temporally ordered memories, but it can also be applied to the design of new biological, electronic or optical devices. These devices may be used in the testing and development of new therapeutic drugs, in the detection of toxic agents or impaired performance, or in the development of new industrial and consumer devices in which the orderly storage of sequential information is …

Metabolic Oscillations In Pancreatic Islets Depend On The Intracellular Ca2+ Level But Not Ca2+ Oscillations, Matthew J. Merrins, Bernard Fendler, Min Zhang, Arthur Sherman, Richard Bertram, Leslie S. Satin

Pharmacology and Toxicology Publications

Abstract

Plasma insulin is pulsatile and reflects oscillatory insulin secretion from pancreatic islets. Although both islet Ca²⁺ and metabolism oscillate, there is disagreement over their interrelationship, and whether they can be dissociated. In some models of islet oscillations, Ca²⁺ must oscillate for metabolic oscillations to occur, whereas in others metabolic oscillations can occur without Ca²⁺ oscillations. We used NAD(P)H fluorescence to assay oscillatory metabolism in mouse islets stimulated by 11.1 mM glucose. After abolishing Ca²⁺ oscillations with 200 μM diazoxide, we observed that oscillations in NAD(P)H persisted in 34% of islets (n = 101). …

A Transposon In Comt Generates Mrna Variants And Causes Widespread Expression And Behavioral Differences Among Mice, Zhengsheng Li, Megan K. Mulligan, Xusheng Wang, Michael F. Miles, Lu Lu, Robert W. Williams

Pharmacology and Toxicology Publications

Background

Catechol-O-methyltransferase (COMT) is a key enzyme responsible for the degradation of dopamine and norepinephrine. COMT activity influences cognitive and emotional states in humans and aggression and drug responses in mice. This study identifies the key sequence variant that leads to differences in Comt mRNA and protein levels among mice, and that modulates synaptic function and pharmacological and behavioral traits.

Methodology/Principal Findings

We examined Comt expression in multiple tissues in over 100 diverse strains and several genetic crosses. Differences in expression map back to Comt and are generated by a 230 nt insertion of a B2 short interspersed element (B2 …

Racial Differences In Genetic And Environmental Risk To Preterm Birth, Timothy P. York, Jerome F. Strauss Iii, Michael C. Neale, Lindon J. Eaves

Human and Molecular Genetics Publications

Preterm birth is more prevalent in African Americans than European Americans and contributes to 3.4 times more African American infant deaths. Models of social inequity do not appreciably account for this marked disparity and molecular genetic studies have yet to characterize whether allelic differences that exist between races contribute to this gap. In this study, biometrical genetic models are applied to a large mixed-race sample consisting of 733,339 births to measure the extent that heritable factors and environmental exposures predict the timing of birth and explain differences between racial groups. Although we expected significant differences in mean gestational age between …

Development Of A Syngeneic Mouse Model Of Epithelial Ovarian Cancer, Bridget A. Quinn, Fang Xiao, Laura Bickel, Lainie Martin, Xiang Hua, Andres Klein-Szanto, Denise C. Connolly

Human and Molecular Genetics Publications

Background

Most cases of ovarian cancer are epithelial in origin and diagnosed at advanced stage when the cancer is widely disseminated in the peritoneal cavity. The objective of this study was to establish an immunocompetent syngeneic mouse model of disseminated epithelial ovarian cancer (EOC) to facilitate laboratory-based studies of ovarian tumor biology and preclinical therapeutic strategies.

Methods

Individual lines of TgMISIIR-TAg transgenic mice were phenotypically characterized and backcrossed to inbred C57BL/6 mice. In addition to a previously described line of EOC-prone mice, two lines (TgMISIIR-TAg-Low) were isolated that express the oncogenic transgene, but have little or no …

Treatment Strategies In Acute Myelogenous Leukemia : Investigating Hsp90 And P53 As Targets, Jennifer M. Napper

Theses, Dissertations and Capstones

Acute myelogenous leukemia (AML) is the deadliest of the lymphatic and bone marrow cancers. Patients diagnosed with AML have a five year survival rate of 23.4%. AML is characterized by an accumulation of undifferentiated and functionless myeloid precursors in the bone marrow and blood. Heat shock protein 90 (Hsp90) inhibitors, such as 17-AAG, an analog of geldanamycin (GM), are currently undergoing phase I, and II and III clinical trials for various cancers with mixed results. I found distinct responses to 17-AAG treatment among the AML cell lines tested. I also discovered two mutant TP53 alleles in Kasumi-3 cells, an AML …

Genetic And Environmental Factors Suggest That Dietary Fatty Acid Content, Lipid Metabolism, And Bone Properties Are Key Regulators Of Myeloid Progenitor Cell Frequency, Melinda E. Varney

Theses, Dissertations and Capstones

Acute myelogenous leukemia (AML) and its precursors are the result of the dysregulation of hematopoiesis. Hematopoiesis proceeds in a stepwise manner, beginning with hematopoietic stem cells, continuing to develop into various stages of progenitor cells, and finally becoming fully functional blood cells. As this process goes awry, immature, functionless cells of the myeloid lineage proliferate out of control. Discerning how myeloid progenitor frequency is regulated allows for a better understanding of how the process may lose control. Hematopoiesis has been shown to depend on genetic and environmental factors. In this work, I have added to this knowledge base by providing …

The Expression And Function Of Hypoxia Inducible Factor-1Α In Human Melanoma, Sandeep S. Joshi

Theses, Dissertations and Capstones

Hypoxia inducible factor-1α (HIF-1α) protein, a key regulator of oxygen homeostasis, is stabilized under hypoxia and degraded under normal oxygen tension. Here, the human melanoma cells were found to express an elevated amount of HIF-1α mRNA and protein relative to normal human melanocytes under normoxic conditions. The amount of HIF-1α expressed is roughly correlated with the stage of melanoma from which the cell line was established. In addition, a splice variant mRNA of HIF-1α785 is expressed at higher levels than full-length HIF-1α mRNA in the more aggressive melanoma cells. This splice variant lacks part of the oxygen regulation domain. Ectopic …

Electrospun Nanofibers For Neural Tissue Engineering, Jingwei Xie, Matthew R. Macewan, Andrea G. Schwartz, Younan Xia

MIIR Faculty Research

Biodegradable nanofibers produced by electrospinning represent a new class of promising scaffolds to support nerve regeneration. We begin with a brief discussion on electrospinning of nanofibers and methods for controlling the structure, porosity, and alignment of the electrospun nanofibers. The methods include control of the nanoscale morphology and microscale alignment for the nanofibers, as well as the fabrication of macroscale, three-dimensional tubular structures. We then highlight recent studies that utilize electrospun nanofibers to manipulate biological processes relevant to nervous tissue regeneration, including stem cell differentiation, guidance of neurite extension, and peripheral nerve injury treatments. The main objective of this feature …

Fluprostenol-Induced Mapk Signaling Is Independent Of Aging In Fischer 344/Nniahsd X Brown Norway/Binia Rat Aorta, Kevin M. Rice, Ernest M. Walker, Sunil K. Kakarla, Satyanarayana Paturi, Miaozong Wu, Sumit Narula, Eric R. Blough

MIIR Faculty Research

The factors that regulate vascular mechanotransduction and how this process may be altered with aging are poorly understood and have not been widely studied. Recent data suggest that increased tissue loading can result in the release of prostaglandin F2 alpha (PGF2α) and other reports indicate that aging diminishes the ability of the aged aorta to activate mitogen activated protein kinase (MAPK) signaling in response to increased loading. Using ex vivo incubations, here we investigate whether aging affects the ability of the aorta to induce phosphorylation of extracellular signal-regulated kinase 1/2 (ERK½-MAPK), p38-MAPK, and Jun N-terminal kinase (JNK-MAPK) activation following stimulation …

Fusion, 2010, George Washington University, William H. Beaumont Medical Research Honor Society

Fusion

No abstract provided.

Large Scale Analysis Of Positional Effects Of Single-Base Mismatches On Microarray Gene Expression Data, Fenghai Duan, Mark A. Pauley, Eliot R. Spindel, Li Zhang, Robert B. Norgren

Journal Articles: Genetics, Cell Biology & Anatomy

BACKGROUND: Affymetrix GeneChips utilize 25-mer oligonucleotides probes linked to a silica surface to detect targets in solution. Mismatches due to single nucleotide polymorphisms (SNPs) can affect the hybridization between probes and targets. Previous research has indicated that binding between probes and targets strongly depends on the positions of these mismatches. However, there has been substantial variability in the effect of mismatch type across studies.

METHODS: By taking advantage of naturally occurring mismatches between rhesus macaque transcripts and human probes from the Affymetrix U133 Plus 2 GeneChip, we collected the largest 25-mer probes dataset with single-base mismatches at each of the …

Prevention Of Fetal Alcohol Damage In Northern Native Communities: A Practical School-Based Approach, Steven Jacquier, Judith Kleinfeld, David Gilliam

SPS Faculty Publications

This article describes a Fetal Alcohol Syndrome prevention program, "FASD in Lab Mice," that had a dramatic effect in increasing Alaska Native students' understanding of the lifelong neurological and physical damage caused by drinking during pregnancy and, more importantly, led them to engage in active prevention efforts in their own and other Native communities. Informational programs typically used in the schools create little student interest and students often do not see connections between their own experience and the atypically extreme examples such prevention programs tend to emphasize. The "FASD in Lab Mice" prevention program, using actual experiments conducted by the …

Mass Spectrometric Analyses Of Organophosphate Insecticide Oxon Protein Adducts, Charles M. Thompson, John M. Prins, Kathleen M. George

Biomedical and Pharmaceutical Sciences Faculty Publications

OBJECTIVE: Organophosphate (OP) insecticides continue to be used to control insect pests. Acute and chronic exposures to OP insecticides have been documented-to cause adverse health effects, but few OP-adducted proteins have been correlated with these illnesses at the molecular level. Our aim was to review the literature covering the current state of the art in mass spectrometry (MS) used to identify OP protein biomarkers. DATA SOURCES AND EXTRACTION: We identified general and specific research reports related to OP insecticides, OP toxicity, OP structure, and protein MS by searching PubMed and Chemical Abstracts for articles published before December 2008. DATA SYNTHESIS: …

Cellular Automata Rules Generator For Microbial Communities, Melissa Marie Quintana

Theses Digitization Project

The purpose of this project is to provide a visual representation as program output so that the rules and the radius of effect can be estimated. Currently there is a need for a method that extracts the cellular automata rules which simulate the growth patterns of microbial communities found within extreme environments. Contains source code.

To Live And Die In Ca, Jane Frances Curnutt

Theses Digitization Project

This thesis investigates the nature of elementary cellular automata to better understand their relationship of the models they support to the biological organisms that create the mats and soil crusts found in extreme environments here on earth. Cellular automata have been used to study growth and patterns in forests, arid desert environments, predator-prey problems, and sea shells. It has also been used to study areas of diverse epidemiology and linguistics. Cellular automata have been used as the core of computer games as well. This investigation has led to develop a graphical grammar for simple cellular automata, using L-systems, a grammar …

Use Of Electronic Anatomy Practical Examinations For Remediating “At Risk” Students, Frank J. Daly

Biomedical Sciences Faculty Publications

Restrictive laboratory scheduling, an increasing number of human cadaver-based anatomy courses and a reduction in the curricular time allotted to anatomy courses have created problems with cadaver laboratory access at the University of New England. This article describes a combination of anatomy testing and grading strategies to allow “at risk” (borderline failing) students an opportunity to remediate their lowest set of examination scores and pass their anatomy course. An alternative electronic practical examination for these students provided flexibility in laboratory scheduling, thereby increasing laboratory access for other students taking concurrent courses. Specifically, the electronic examinations allowed for a reduction in …