Digital Commons Network^™

Hereditary 1,25-Dihydroxyvitamin D-Resistant Rickets With Alopecia Resulting From A Novel Missense Mutation In The Dna-Binding Domain Of The Vitamin D Receptor., Peter J. Malloy, Jining Wang, Tarak Srivastava, David Feldman

Manuscripts, Articles, Book Chapters and Other Papers

The rare genetic recessive disease, hereditary vitamin D resistant rickets (HVDRR), is caused by mutations in the vitamin D receptor (VDR) that result in resistance to the active hormone 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3) or calcitriol). In this study, we examined the VDR from a young boy with clinical features of HVDRR including severe rickets, hypocalcemia, hypophosphatemia and partial alopecia. The pattern of alopecia was very unusual with areas of total baldness, adjacent to normal hair and regions of scant hair. The child failed to improve on oral calcium and vitamin D therapy but his abnormal chemistries and his bone X-rays normalized …

Individualized Cognitive Modeling For Close-Loop Task Mitigation, Guangfan Zhang, Roger Xu, Wei Wang, Jiang Li, Tom Schnell, Mike Keller, Thomas E. Pinelli (Ed.)

Electrical & Computer Engineering Faculty Publications

An accurate real-time operator functional state assessment makes it possible to perform task management, minimize risks, and improve mission performance. In this paper, we discuss the development of an individualized operator functional state assessment model that identifies states likely leading to operational errors. To address large individual variations, we use two different approaches to build a model for each individual using its data as well as data from subjects with similar responses. If a subject's response is similar to that of the individual of interest in a specific functional state, all the training data from this subject will be used …

Autotaxin: A Regulator Of Oligodendrocyte Differentiation, Larra Yuelling

Theses and Dissertations

In order for oligodendrocyte progenitor cells (OPCs) to differentiate into fully mature, myelinating oligodendrocytes, they must be specified at the correct times and undergo coordinated changes in both gene expression and morphology. As oligodendrocytes differentiate, they transition from a bipolar morphology into a morphology characterized by a complex network of multiple processes, which will eventually generate membranous structures necessary for myelination of axonal segments. As changes are observed in cellular morphology, oligodendrocytes also undergo changes in their gene expression profile and express genes necessary for both early and later stages of development such as olig1 and myelin basic protein (mbp), …

Anomalous Constitutive Src Kinase Activity Promotes B Lymphoma Survival And Growth, Jiyuan Ke, R. Lakshman Chelvarajan, Vishal Sindhava, Darrell A. Robertson, Lazaros Lekakis, C. Darrell Jennings, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Background: Previously we have shown that B cell receptor (BCR) expression and B cell receptor signaling pathways are important for the basal growth of B lymphoma cells. In particular we have shown that the activation of Syk, a non-src family protein tyrosine kinase and the mitogen activated protein kinases (MAPK), ERK and JNK that mediate BCR signals are required for the constitutive growth of B lymphoma cells. Since src family protein tyrosine kinases (SFKs) like Lyn are known to be needed for the phosphorylation of BCR co-receptors, Ig-alpha and Ig-beta, we hypothesized that one or more SFKs will be constitutively …

Proteolytic Regulation Of Toxin-Antitoxin Systems By Clppc In Staphylococcus Aureus, Niles P. Donegan, Earl T. Thompson, Zhibiao Fu, Ambrose L. Cheung

Dartmouth Scholarship

Bacterial toxin-antitoxin (TA) systems typically consist of a small, labile antitoxin that inactivates a specific longer-lived toxin. In Escherichia coli, such antitoxins are proteolytically regulated by the ATP-dependent proteases Lon and ClpP. Under normal conditions, antitoxin synthesis is sufficient to replace this loss from proteolysis, and the bacterium remains protected from the toxin. However, if TA production is interrupted, antitoxin levels decrease, and the cognate toxin is free to inhibit the specific cellular component, such as mRNA, DnaB, or gyrase. To date, antitoxin degradation has been studied only in E. coli, so it remains unclear whether similar mechanisms of regulation …

Gbdr Regulates Pseudomonas Aeruginosa Plch And Pchp Transcription In Response To Choline Catabolites, Matthew J. Wargo, Tiffany C. Ho, Maegan J. Gross, Laurie A. Whittaker, Deborah A. Hogan

Dartmouth Scholarship

Pseudomonas aeruginosa hemolytic phospholipase C, PlcH, can degrade phosphatidylcholine (PC) and sphingomyelin in eukaryotic cell membranes and extracellular PC in lung surfactant. Numerous studies implicate PlcH in P. aeruginosa virulence. The phosphorylcholine released by PlcH activity on phospholipids is hydrolyzed by a periplasmic phosphorylcholine phosphatase, PchP. Both plcH gene expression and PchP enzyme activity are positively regulated by phosphorylcholine degradation products, including glycine betaine. Here we report that the induction of plcH and pchP transcription by glycine betaine is mediated by GbdR, an AraC family transcription factor. Mutants that lack gbdR are unable to induce plcH and pchP in media …

Germinal Center Reutilization By Newly Activated B Cells., Tanja A Schwickert, Boris Alabyev, Tim Manser, Michel C Nussenzweig

Department of Microbiology and Immunology Faculty Papers

Germinal centers (GCs) are specialized structures in which B lymphocytes undergo clonal expansion, class switch recombination, somatic hypermutation, and affinity maturation. Although these structures were previously thought to contain a limited number of isolated B cell clones, recent in vivo imaging studies revealed that they are in fact dynamic and appear to be open to their environment. We demonstrate that B cells can colonize heterologous GCs. Invasion of primary GCs after subsequent immunization is most efficient when T cell help is shared by the two immune responses; however, it also occurs when the immune responses are entirely unrelated. We conclude …

T Cell Receptor Cross-Reactivity Directed By Antigen-Dependent Tuning Of Peptide-Mhc Molecular Flexibility, Oleg Y. Borbulevych, Kurt H. Piepenbrink, Brian E. Gloor, Daniel R. Scott, Ruth F. Sommese, David K. Cole, Andrew K. Sewell, Brian M. Baker

Food for Health: Publications

Tell mediated immunity requires T cell receptor (TCR) cross-reactivity, the mechanisms behind which remain incompletely elucidated. The αβ TCR A6 recognizes both the Tax (LLFGYPVYV) and Tel1p (MLWGYLQYV) peptides presented by the human class I MHC molecule HLA-A2. Here we found that although the two ligands are ideal structural mimics, they form substantially different interfaces with A6, with conformational differences in the peptide, the TCR, and unexpectedly, the MHC molecule. The differences between the Tax and Tel1p ternary complexes could not be predicted from the free peptide-MHC structures and are inconsistent with a traditional induced-fit mechanism. Instead, the differences were …

The Danger Signal Adenosine Induces Persistence Of Chlamydial Infection Through Stimulation Of A2b Receptors, Matthew A. Pettengill, Verissa W. Lam, David M. Ojcius

All Dugoni School of Dentistry Faculty Articles

Infections with intracellular bacteria such as chlamydiae affect the majority of the world population. Infected tissue inflammation and granuloma formation help contain the short-term expansion of the invading pathogen, leading also to local tissue damage and hypoxia. However, the effects of key aspects of damaged inflamed tissues and hypoxia on continued infection with intracellular bacteria remain unknown. We find that development of Chlamydia trachomatis is reversibly retarded by prolonged exposure of infected cells to extracellular adenosine, a hallmark of hypoxia and advanced inflammation. In epithelial cells, this effect was mediated by the A2b adenosine receptor, unique in the adenosine receptor …

Gamma Motor Neurons Express Distinct Genetic Markers At Birth And Require Muscle Spindle-Derived Gdnf For Postnatal Survival, Neil A. Shneider, Meghan N. Brown, Courtney A. Smith, James Pickel, Francisco J. Alvarez

Neuroscience, Cell Biology & Physiology Faculty Publications

Background: Gamma motor neurons (γ-MNs) selectively innervate muscle spindle intrafusal fibers and regulate their sensitivity to stretch. They constitute a distinct subpopulation that differs in morphology, physiology and connectivity from α-MNs, which innervate extrafusal muscle fibers and exert force. The mechanisms that control the differentiation of functionally distinct fusimotor neurons are unknown. Progress on this question has been limited by the absence of molecular markers to specifically distinguish and manipulate γ-MNs. Recently, it was reported that early embryonic γ-MN precursors are dependent on GDNF. Using this knowledge we characterized genetic strategies to label developing γ-MNs based on GDNF receptor expression, …

Structural Characterization Of The C-Terminus Of The Cochlear Motor Protein Prestin: Intrinsic Disorder Linked To Voltage Sensor Function, Michael S. Podgorski

Theses and Dissertations (ETD)

The sensitivity of mammalian hearing relies upon the ability to amplify sound. Outer hair cells (OHCs) in the cochlea have motile properties that support this function. The motor protein called prestin resides in the lateral wall of the OHCs. Prestin undergoes voltage-dependent conformational changes, which correlates to the movement of charge through the membrane or non-linear capacitance (NLC). This property underlies OHC electromotility. A mechanistic understanding of prestin’s function remains unknown. Previous research has tied prestin’s C-terminus (residues 499-799) to the voltage-dependent events that occur in the membrane. The folding and biochemical properties of prestin’s C-terminus were characterized. This information …

Altered Regulation Of Contraction-Induced Akt/Mtor/P70s6k Pathway Signaling In Skeletal Muscle Of The Obese Zucker Rat, Anjaiah Katta, Sunil K. Kakarla, Miaozong Wu, Satyanarayana Paturi, Murali K. Gadde, Ravi K. Arvapalli, Madhukar Babu Kolli, Kevin M. Rice, Eric R. Blough

MIIR Faculty Research

Increased muscle loading results in the phosphorylation of the 70 kDa ribosomal S6 kinase (p70S6k), and this event is strongly correlated with the degree of muscle adaptation following resistance exercise. Whether insulin resistance or the comorbidities associated with this disorder may affect the ability of skeletal muscle to activate p70S6k signaling following an exercise stimulus remains unclear. Here, we compare the contraction-induced activation of p70S6k signaling in the plantaris muscles of lean and insulin resistant obese Zucker rats following a single bout of increased contractile loading. Compared to lean animals, the basal phosphorylation of p70S6k (Thr389; 37.2% and Thr421/Ser424; 101.4%), …

Epocrates….Is It Useful At The Neonatal Bedside?, Bobby L. Miller Md

Biochemistry and Microbiology

Most physicians, including residents and medical students have heard of, and many use, a mobile drug database called Epocrates. The purpose of this review is to evaluate Epocrates as a bedside tool from the perspective of a neonatologist on a busy teaching service.

Fluorescent Protein Markers To Tag Collagenous Proteins: The Paradigm Of Procollagen Vii, Hye J. Chung, Andrzej Steplewski, Jouni Uitto, Andrzej Fertala

Department of Dermatology and Cutaneous Biology Faculty Papers

Fluorescent proteins are powerful markers allowing tracking expression, intracellular localization, and translocation of tagged proteins but their effects on the structure and assembly of complex extracellular matrix proteins has not been investigated. Here, we analyzed the utility of fluorescent proteins as markers for procollagen VII, a triple-helical protein critical for the integrity of dermal-epidermal junction. DNA constructs encoding a red fluorescent protein-tagged wild type mini-procollagen VII α chain and green fluorescent protein-tagged α chains harboring selected mutations were genetically engineered. These DNA constructs were co-expressed in HEK-293 cells and the assembly of heterogeneous triple-helical mini-procollagen VII molecules was analyzed. Immunoprecipitation …

Apolipoprotein E But Not B Is Required For The Formation Of Infectious Hepatitis C Virus Particles, Jieyun Jiang, Guangxiang Luo

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Our previous studies have found that hepatitis C virus (HCV) particles are enriched in apolipoprotein E (apoE) and that apoE is required for HCV infectivity and production. Studies by others, however, suggested that both microsomal transfer protein (MTP) and apoB are important for HCV production. To define the roles of apoB and apoE in the HCV life cycle, we developed a single-cycle HCV growth assay to determine the correlation of HCV assembly with apoB and apoE expression, as well as the influence of MTP inhibitors on the formation of HCV particles. The small interfering RNA (siRNA)-mediated knockdown of apoE expression …

Pandemic Potential Of Reassortant Swine Influenza A Viruses, Christy Brockwell Staats

Theses and Dissertations (ETD)

Influenza A viruses are capable of causing disease in several species, including birds, humans and swine. Host specificity of the viruses is not absolute, and is influenced by a range of factors. Swine play a pivotal role in the interspecies transmission of influenza A viruses, as they are susceptible to infection with both human and avian strains and have been implicated as a “mixing vessel” for the reassortment of influenza A viruses from different species. The reassortment of influenza A viruses of human and avian origin led to human influenza pandemics in 1957 and 1968.

The dynamics of swine influenza …

Il-4(-/-) Mice With Lethal Mesocestoides Corti Infections--Reduced Th2 Cytokines And Alternatively Activated Macrophages., A. E. O'Connell, L. A. Kerepesi, G. L. Vandergrift, D. R. Herbert, T J. Van Winkle, D. C. Hooper, E J. Pearce, D. Abraham

Department of Microbiology and Immunology Faculty Papers

Protection against Mesocestoides corti, a cestode that invades vital organs, is dependent on the production of IL-4, as IL-4(-/-) mice were found to have higher parasite burdens when compared with wild-type mice. The goal of this study was to investigate the role of IL-4 in immunity to M. corti, focusing on the immunological profile and on potential mediators of pathology. IL-4(-/-) mice infected with M. corti showed 100% mortality by 32 days, whereas wild-type mice survived for approximately 1 year. Parasite burdens were significantly increased in the liver, peritoneal, and thoracic cavities of IL-4(-/-) mice, associated with impaired recruitment of …

Inactivation Of The Fliy Gene Encoding A Flagellar Motor Switch Protein Attenuates Mobility And Virulence Of Leptospira Interrogans Strain Lai, Sumei Liao, Ai-Hua Sun, David M. Ojcius, Senlin Wu, Jinfang Zhao, Jie Yan

All Dugoni School of Dentistry Faculty Articles

Background: Pathogenic Leptospira species cause leptospirosis, a zoonotic disease of global importance. The spirochete displays active rotative mobility which may contribute to invasion and diffusion of the pathogen in hosts. FliY is a flagellar motor switch protein that controls flagellar motor direction in other microbes, but its role in Leptospira, and paricularly in pathogenicity remains unknown.

Results: A suicide plasmid for the fliY gene of Leptospira interrogans serogroup Icterohaemorrhagiae serovar Lai strain Lai that was disrupted by inserting the ampicillin resistance gene (bla) was constructed, and the inactivation of fliY gene in a mutant (fliY-) was confirmed by PCR and …

Mitochondrial Mislocalization Underlies Abeta42-Induced Neuronal Dysfunction In A Drosophila Model Of Alzheimer's Disease., Kanae Iijima-Ando, Stephen A Hearn, Christopher Shenton, Anthony Gatt, Lijuan Zhao, Koichi Iijima

Department of Biochemistry and Molecular Biology Faculty Papers

The amyloid-beta 42 (Abeta42) is thought to play a central role in the pathogenesis of Alzheimer's disease (AD). However, the molecular mechanisms by which Abeta42 induces neuronal dysfunction and degeneration remain elusive. Mitochondrial dysfunctions are implicated in AD brains. Whether mitochondrial dysfunctions are merely a consequence of AD pathology, or are early seminal events in AD pathogenesis remains to be determined. Here, we show that Abeta42 induces mitochondrial mislocalization, which contributes to Abeta42-induced neuronal dysfunction in a transgenic Drosophila model. In the Abeta42 fly brain, mitochondria were reduced in axons and dendrites, and accumulated in the somata without severe mitochondrial …

Regulation Of Energy Stores And Feeding By Neuronal And Peripheral Creb Activity In Drosophila., Koichi Iijima, Lijuan Zhao, Christopher Shenton, Kanae Iijima-Ando

Department of Biochemistry and Molecular Biology Faculty Papers

The cAMP-responsive transcription factor CREB functions in adipose tissue and liver to regulate glycogen and lipid metabolism in mammals. While Drosophila has a homolog of mammalian CREB, dCREB2, its role in energy metabolism is not fully understood. Using tissue-specific expression of a dominant-negative form of CREB (DN-CREB), we have examined the effect of blocking CREB activity in neurons and in the fat body, the primary energy storage depot with functions of adipose tissue and the liver in flies, on energy balance, stress resistance and feeding behavior. We found that disruption of CREB function in neurons reduced glycogen and lipid stores …

Discovery And Validation Of New Regulatory Rna Elements In Chlamydia Trachomatis, Yasser Mohammed Elsayed Metwally Abdelrahman

Theses and Dissertations (ETD)

Chlamydia trachomatis is an obligate intracellular bacterium that exhibits a unique biphasic developmental cycle that can be disrupted by growth in the presence of IFN-g and b-lactams, giving rise to an abnormal growth state termed persistence. Relatively little is known about the regulatory mechanisms that control temporal gene expression during the developmental cycle or the control of persistence and reactivation. Here we have examined the expression of a newly defined family of non-coding RNAs (ncRNAs) that are differentially expressed during the developmental cycle and the induction of persistence and reactivation (Using IFNγ and Carbenicillin). Non-coding RNAs were initially identified using …

Identification Of The Downstream Effector Genes Involved In Hoxb4-Induced Expansion Of Hematopoietic Progenitor Cells, Jie Jiang

Theses and Dissertations (ETD)

Overexpression of HOXB4, a member of Homeobox transcription factor family, promotes expansion of hematopoietic stem and progenitor cells bothin vivo and in vitro. However, the molecular mechanisms underlying this effect are not well understood. In order to identify direct target genes of HOXB4 in primary murine hematopoietice progenitor cells, we induced HOXB4 function in lineage-negative, murine bone marrow cells, using a tamoxifen-inducibleHOXB4-ER^T2fusion protein. Seventy seven genes with differentially changed expression in early response to HOXB4 have been identified as candidate target genes. Among them, we show that Hemogen (Hemgn), encoding a nuclear protein specifically …

Association Tests Of The Opioid Receptor System And Alcohol-Related Traits, Ryan Bennett

Theses and Dissertations

The opioid receptors and their endogenous ligands have long been implicated in a variety of traits including addiction, impulsive behaviors and substance dependence. Using phenotypic measurements collected from the IASPSAD, data from a latent class analysis and data from a SNP array and additional genotyping assays, association and regression tests were performed to determine the effects of common SNPs encoded in the genes of the opioid receptors and ligands on various traits relating to alcohol dependence. Although only one SNP can be reported as significant for substance dependence within alcoholics, there were a few results approaching significance that may offer …

Biological Diversity Of Prokaryotic Type Iv Secretion Systems, Cristina E Alvarez-Martinez, Peter J Christie

Faculty, Staff and Student Publications

Type IV secretion systems (T4SS) translocate DNA and protein substrates across prokaryotic cell envelopes generally by a mechanism requiring direct contact with a target cell. Three types of T4SS have been described: (i) conjugation systems, operationally defined as machines that translocate DNA substrates intercellularly by a contact-dependent process; (ii) effector translocator systems, functioning to deliver proteins or other macromolecules to eukaryotic target cells; and (iii) DNA release/uptake systems, which translocate DNA to or from the extracellular milieu. Studies of a few paradigmatic systems, notably the conjugation systems of plasmids F, R388, RP4, and pKM101 and the Agrobacterium tumefaciens VirB/VirD4 system, …

Genetic Commonality Of Macrolide-Resistant Group A Beta Hemolytic Streptococcus Pharyngeal Strains, Angela Myers, Mary Anne Jackson, Rangaraj Selvarangan, Richard V. Goering, Christopher J. Harrison

Manuscripts, Articles, Book Chapters and Other Papers

Background: Group A beta hemolytic streptococcus (GABHS) pharyngitis is a common childhood illness. Penicillin remains the gold standard therapy, but macrolides are indicated for the penicillin allergic patient, and are often used for convenience.

Methods: We conducted a surveillance study of children with pharyngitis and positive streptococcal rapid antigen testing from 10/05 to 10/06 at 2 sites (A & B). Demographics, treatment, and resistance data was collected and compared to previous data from 2002. Erythromycin (EM) resistance was determined by disk diffusion and E-test on 500 isolates. Pulse field gel electrophoresis (PFGE) was performed to measure genetic relatedness of isolates. …

Dopamine-Stimulated Dephosphorylation Of Connexin 36 Mediates Aii Amacrine Cell Uncoupling, W Wade Kothmann, Stephen C Massey, John O'Brien

Faculty, Staff and Student Publications

Gap junction proteins form the substrate for electrical coupling between neurons. These electrical synapses are widespread in the CNS and serve a variety of important functions. In the retina, connexin 36 (Cx36) gap junctions couple AII amacrine cells and are a requisite component of the high-sensitivity rod photoreceptor pathway. AII amacrine cell coupling strength is dynamically regulated by background light intensity, and uncoupling is thought to be mediated by dopamine signaling via D(1)-like receptors. One proposed mechanism for this uncoupling involves dopamine-stimulated phosphorylation of Cx36 at regulatory sites, mediated by protein kinase A. Here we provide evidence against this hypothesis …

Effects Of Cannabinoid Receptor Interacting Protein (Crip1a) On Cannabinoid Receptor (Cb1) Function, Tricia Smith

Theses and Dissertations

EFFECTS OF CANNABINOID RECEPTOR INTERACTING PROTEIN (CRIP1a) ON CANNABINOID (CB1) RECEPTOR FUNCTION. By Tricia Hardt Smith, B.S., M.S. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University Virginia Commonwealth University, 2009. Major Director: Dana E. Selley, Ph.D., Department of Pharmacology and Toxicology This dissertation examines modulation of cannabinoid CB1 receptor function by Cannabinoid Receptor Interacting Protein (CRIP1a), a novel protein that binds the C-terminus of CB1 receptors. In Human embryonic kidney cells expressing human CB1 receptors (hCB1-HEK) and hCB1-HEK cells stably co-expressing CRIP1a (hCB1-HEK-CRIP1a), quantitative immunoblotting revealed a CRIP1a/CB1 …

Detection Of Sub-Clinical Cwd Infection In Conventional Test-Negative Deer Long After Oral Exposure To Urine And Feces From Cwd+ Deer, Nicholas J. Haley, Candace K. Mathiason, Mark D. Zabel, Glenn C. Telling, Edward A Hoover

Microbiology, Immunology, and Molecular Genetics Faculty Publications

BACKGROUND: Chronic wasting disease (CWD) of cervids is a prion disease distinguished by high levels of transmissibility, wherein bodily fluids and excretions are thought to play an important role. Using cervid bioassay and established CWD detection methods, we have previously identified infectious prions in saliva and blood but not urine or feces of CWD+ donors. More recently, we identified very low concentrations of CWD prions in urine of deer by cervid PrP transgenic (Tg[CerPrP]) mouse bioassay and serial protein misfolding cyclic amplification (sPMCA). This finding led us to examine further our initial cervid bioassay experiments using sPMCA.

OBJECTIVES: We sought …

Evaluating Forensic Dna Evidence, Dan E. Krane

Biological Sciences Faculty Publications

No abstract provided.

Suppression Of Erbb-2 In Androgen-Independent Human Prostate Cancer Cells Enhances Cytotoxic Effect By Gemcitabine In An Androgen-Reduced Environment., Li Zhang, Jeffrey S. Davis, Stanislav Zelivianski, Fen-Fen Lin, Rachel Schutte, Thomas L. Davis, Ralph Hauke, Surinder K. Batra, Ming-Fong Lin

Journal Articles: Biochemistry & Molecular Biology

We examined the efficacy of combination treatments utilizing cytotoxic drugs plus inhibitors to members of the ErbB-ERK signal pathway in human prostate cancer (PCa) LNCaP C-81 cells. Under an androgen-reduced condition, 50nM gemcitabine caused about 40% growth suppression on C-81 cells. Simultaneous treatment of gemcitabine plus 10microM AG825 produced 60% suppression (p