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Articles 7111 - 7140 of 7750

Full-Text Articles in Medicine and Health Sciences

Regulation Of Energy Stores And Feeding By Neuronal And Peripheral Creb Activity In Drosophila., Koichi Iijima, Lijuan Zhao, Christopher Shenton, Kanae Iijima-Ando Dec 2009

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 …


Tb Research At Ut-Houston – A Review Of Cord Factor: New Approaches To Drugs, Vaccines And The Pathogenesis Of Tuberculosis, Robert L Hunter, Lisa Armitige, Chinnaswamy Jagannath, Jeffrey K Actor Dec 2009

Tb Research At Ut-Houston – A Review Of Cord Factor: New Approaches To Drugs, Vaccines And The Pathogenesis Of Tuberculosis, Robert L Hunter, Lisa Armitige, Chinnaswamy Jagannath, Jeffrey K Actor

Faculty, Staff and Student Publications

Tuberculosis remains a major threat as drug resistance continues to increase. Pulmonary tuberculosis in adults is responsible for 80% of clinical cases and nearly 100% of transmission of infection. Unfortunately, since we have no animal models of adult type pulmonary tuberculosis, the most important type of disease remains largely out of reach of modern science and many fundamental questions remain unanswered. This paper reviews research dating back to the 1950's providing compelling evidence that cord factor (trehalose 6,6 dimycolate [TDM]) is essential for understanding tuberculosis. However, the original papers by Bloch and Noll were too far ahead of their time …


Biological Diversity Of Prokaryotic Type Iv Secretion Systems, Cristina E Alvarez-Martinez, Peter J Christie Dec 2009

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, …


Dopamine-Stimulated Dephosphorylation Of Connexin 36 Mediates Aii Amacrine Cell Uncoupling, W Wade Kothmann, Stephen C Massey, John O'Brien Nov 2009

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 …


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 Nov 2009

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 …


Modulation Of Outer Hair Cell Electromotility By Cochlear Supporting Cells And Gap Junctions, Ning Yu, Hong-Bo Zhao Nov 2009

Modulation Of Outer Hair Cell Electromotility By Cochlear Supporting Cells And Gap Junctions, Ning Yu, Hong-Bo Zhao

Surgery Faculty Publications

Outer hair cell (OHC) or prestin-based electromotility is an active cochlear amplifier in the mammalian inner ear that can increase hearing sensitivity and frequency selectivity. In situ, Deiters supporting cells are well-coupled by gap junctions and constrain OHCs standing on the basilar membrane. Here, we report that both electrical and mechanical stimulations in Deiters cells (DCs) can modulate OHC electromotility. There was no direct electrical conductance between the DCs and the OHCs. However, depolarization in DCs reduced OHC electromotility associated nonlinear capacitance (NLC) and distortion products. Increase in the turgor pressure of DCs also shifted OHC NLC to the negative …


Development Of A Mouse Monoclonal Antibody Cocktail For Post-Exposure Rabies Prophylaxis In Humans., Thomas Müller, Bernhard Dietzschold, Hildegund Ertl, Anthony R Fooks, Conrad Freuling, Christine Fehlner-Gardiner, Jeannette Kliemt, Francois X Meslin, Charles E Rupprecht, Noël Tordo, Alexander I Wanderler, Marie Paule Kieny Nov 2009

Development Of A Mouse Monoclonal Antibody Cocktail For Post-Exposure Rabies Prophylaxis In Humans., Thomas Müller, Bernhard Dietzschold, Hildegund Ertl, Anthony R Fooks, Conrad Freuling, Christine Fehlner-Gardiner, Jeannette Kliemt, Francois X Meslin, Charles E Rupprecht, Noël Tordo, Alexander I Wanderler, Marie Paule Kieny

Department of Microbiology and Immunology Faculty Papers

As the demand for rabies post-exposure prophylaxis (PEP) treatments has increased exponentially in recent years, the limited supply of human and equine rabies immunoglobulin (HRIG and ERIG) has failed to provide the required passive immune component in PEP in countries where canine rabies is endemic. Replacement of HRIG and ERIG with a potentially cheaper and efficacious alternative biological for treatment of rabies in humans, therefore, remains a high priority. In this study, we set out to assess a mouse monoclonal antibody (MoMAb) cocktail with the ultimate goal to develop a product at the lowest possible cost that can be used …


Combination Of Vandetanib, Radiotherapy, And Irinotecan In The Lovo Human Colorectal Cancer Xenograft Model., Phyllis Wachsberger, Randy Burd, Anderson Ryan, Constantine Daskalakis, Adam P. Dicker Nov 2009

Combination Of Vandetanib, Radiotherapy, And Irinotecan In The Lovo Human Colorectal Cancer Xenograft Model., Phyllis Wachsberger, Randy Burd, Anderson Ryan, Constantine Daskalakis, Adam P. Dicker

Department of Radiation Oncology Faculty Papers

PURPOSE: The tumor growth kinetics of the human LoVo colorectal xenograft model was assessed in response to vandetanib, an orally available receptor tyrosine kinase inhibitor, radiotherapy (RT), or irinotecan (CPT-11), as single therapies and in combination. METHODS AND MATERIALS: LoVo cells were injected subcutaneously into the right hind limb (5 x 10(6) cells in 100 microL phosphate-buffered saline) of athymic NCR NUM mice and tumors were grown to a volume of 200-300 mm(3) before treatment. Vandetanib was administered at 50 mg/kg daily orally for 14 days starting on Day 1. RT was given as three fractions (3 x 3 Gy) …


5-Ht And Gaba Modulate Intrinsic Excitability Of Type I Interneurons In Hermissenda, Nan Ge Jin, Lian-Ming Tian, Terry Crow Nov 2009

5-Ht And Gaba Modulate Intrinsic Excitability Of Type I Interneurons In Hermissenda, Nan Ge Jin, Lian-Ming Tian, Terry Crow

Faculty, Staff and Student Publications

The sensory neurons (photoreceptors) in the visual system of Hermissenda are one site of plasticity produced by Pavlovian conditioning. A second site of plasticity produced by conditioning is the type I interneurons in the cerebropleural ganglia. Both photoreceptors and statocyst hair cells of the graviceptive system form monosynaptic connections with identified type I interneurons. Two proposed neurotransmitters in the graviceptive system, serotonin (5-HT) and gamma-aminobutyric acid (GABA), have been shown to modify synaptic strength and intrinsic neuronal excitability in identified photoreceptors. However, the potential role of 5-HT and GABA in plasticity of type I interneurons has not been investigated. Here …


Adherence To Host Extracellular Matrix And Serum Components By Enterococcus Faecium Isolates Of Diverse Origin, Meng Zhao, Jouko Sillanpää, Sreedhar R Nallapareddy, Barbara E Murray Nov 2009

Adherence To Host Extracellular Matrix And Serum Components By Enterococcus Faecium Isolates Of Diverse Origin, Meng Zhao, Jouko Sillanpää, Sreedhar R Nallapareddy, Barbara E Murray

Faculty, Staff and Student Publications

Enterococcus faecium has emerged as an important cause of nosocomial infections over the last two decades. We recently demonstrated collagen type I (CI) as a common adherence target for some E. faecium isolates and a significant correlation was found to exist between acm-mediated CI adherence and clinical origin. Here, we evaluated 60 diverse E. faecium isolates for their adherence to up to 15 immobilized host extracellular matrix and serum components. Adherence phenotypes were most commonly observed to fibronectin (Fn) (20% of the 60 isolates), fibrinogen (17%) and laminin (Ln) (13%), while only one or two of the isolates adhered to …


Mcl-1 Degradation During Hepatocyte Lipoapoptosis., Howard C. Masuoka, Justin L. Mott, Steven F. Bronk, Nathan W. Werneburg, Yuko Akazawa, Scott H. Kaufmann, Gregory J. Gores Oct 2009

Mcl-1 Degradation During Hepatocyte Lipoapoptosis., Howard C. Masuoka, Justin L. Mott, Steven F. Bronk, Nathan W. Werneburg, Yuko Akazawa, Scott H. Kaufmann, Gregory J. Gores

Journal Articles: Biochemistry & Molecular Biology

The mechanisms of free fatty acid-induced lipoapoptosis are incompletely understood. Here we demonstrate that Mcl-1, an anti-apoptotic member of the Bcl-2 family, was rapidly degraded in hepatocytes in response to palmitate and stearate by a proteasome-dependent pathway. Overexpression of a ubiquitin-resistant Mcl-1 mutant in Huh-7 cells attenuated palmitate-mediated Mcl-1 loss and lipoapoptosis; conversely, short hairpin RNA-targeted knockdown of Mcl-1 sensitized these cells to lipoapoptosis. Palmitate-induced Mcl-1 degradation was attenuated by the novel protein kinase C (PKC) inhibitor rottlerin. Of the two human novel PKC isozymes, PKCdelta and PKC, only activation of PKC was observed by phospho-immunoblot analysis. As compared with …


An Eiav Field Isolate Reveals Much Higher Levels Of Subtype Variability Than Currently Reported For The Equine Lentivirus Family, Jodi K. Craigo, Shannon Barnes, Baoshan Zhang, Sheila J. Cook, Laryssa Howe, Charles J. Issel, Ronald C. Montelaro Oct 2009

An Eiav Field Isolate Reveals Much Higher Levels Of Subtype Variability Than Currently Reported For The Equine Lentivirus Family, Jodi K. Craigo, Shannon Barnes, Baoshan Zhang, Sheila J. Cook, Laryssa Howe, Charles J. Issel, Ronald C. Montelaro

Veterinary Science Faculty Publications

BACKGROUND: Equine infectious anemia virus (EIAV), a lentivirus that infects horses, has been utilized as an animal model for the study of HIV. Furthermore, the disease associated with the equine lentivirus poses a significant challenge to veterinary medicine around the world. As with all lentiviruses, EIAV has been shown to have a high propensity for genomic sequence and antigenic variation, especially in its envelope (Env) proteins. Recent studies have demonstrated Env variation to be a major determinant of vaccine efficacy, emphasizing the importance of defining natural variation among field isolates of EIAV. To date, however, published EIAV sequences have been …


Keap1 E3 Ligase-Mediated Downregulation Of Nf-Kappab Signaling By Targeting Ikkbeta, Dung-Fang Lee, Hsu-Ping Kuo, Mo Liu, Chao-Kai Chou, Weiya Xia, Yi Du, Jia Shen, Chun-Te Chen, Longfei Huo, Ming-Chuan Hsu, Chia-Wei Li, Qingqing Ding, Tsai-Lien Liao, Chien-Chen Lai, Ann-Chi Lin, Ya-Hui Chang, Shih-Feng Tsai, Long-Yuan Li, Mien-Chie Hung Oct 2009

Keap1 E3 Ligase-Mediated Downregulation Of Nf-Kappab Signaling By Targeting Ikkbeta, Dung-Fang Lee, Hsu-Ping Kuo, Mo Liu, Chao-Kai Chou, Weiya Xia, Yi Du, Jia Shen, Chun-Te Chen, Longfei Huo, Ming-Chuan Hsu, Chia-Wei Li, Qingqing Ding, Tsai-Lien Liao, Chien-Chen Lai, Ann-Chi Lin, Ya-Hui Chang, Shih-Feng Tsai, Long-Yuan Li, Mien-Chie Hung

Faculty, Staff and Student Publications

IkappaB kinase beta (IKKbeta) is involved in tumor development and progression through activation of the nuclear factor (NF)-kappaB pathway. However, the molecular mechanism that regulates IKKbeta degradation remains largely unknown. Here, we show that a Cullin 3 (CUL3)-based ubiquitin ligase, Kelch-like ECH-associated protein 1 (KEAP1), is responsible for IKKbeta ubiquitination. Depletion of KEAP1 led to the accumulation and stabilization of IKKbeta and to upregulation of NF-kappaB-derived tumor angiogenic factors. A systematic analysis of the CUL3, KEAP1, and RBX1 genomic loci revealed a high percentage of genome loss and missense mutations in human cancers that failed to facilitate IKKbeta degradation. Our …


Mast Cell–Derived Particles Deliver Peripheral Signals To Remote Lymph Nodes, Christian A. Kunder, Ashley L. St. John, Guojie Li, Kam W. Leong, Brent Berwin, Herman F. Staats, Soman N. Abraham Oct 2009

Mast Cell–Derived Particles Deliver Peripheral Signals To Remote Lymph Nodes, Christian A. Kunder, Ashley L. St. John, Guojie Li, Kam W. Leong, Brent Berwin, Herman F. Staats, Soman N. Abraham

Dartmouth Scholarship

During infection, signals from the periphery are known to reach draining lymph nodes (DLNs), but how these molecules, such as inflammatory cytokines, traverse the significant distances involved without dilution or degradation remains unclear. We show that peripheral mast cells, upon activation, release stable submicrometer heparin-based particles containing tumor necrosis factor and other proteins. These complexes enter lymphatic vessels and rapidly traffic to the DLNs. This physiological drug delivery system facilitates communication between peripheral sites of inflammation and remote secondary lymphoid tissues.


The Production Of Antibody By Invading B Cells Is Required For The Clearance Of Rabies Virus From The Central Nervous System., D Craig Hooper, Timothy W Phares, Marzena J Fabis, Anirban Roy Oct 2009

The Production Of Antibody By Invading B Cells Is Required For The Clearance Of Rabies Virus From The Central Nervous System., D Craig Hooper, Timothy W Phares, Marzena J Fabis, Anirban Roy

Department of Cancer Biology Faculty Papers

BACKGROUND: The pathogenesis of rabies is associated with the inability to deliver immune effectors across the blood-brain barrier and to clear virulent rabies virus from CNS tissues. However, the mechanisms that facilitate immune effector entry into CNS tissues are induced by infection with attenuated rabies virus.

METHODOLOGY/PRINCIPAL FINDINGS: Infection of normal mice with attenuated rabies virus but not immunization with killed virus can promote the clearance of pathogenic rabies virus from the CNS. T cell activity in B cell-deficient mice can control the replication of attenuated virus in the CNS, but viral mRNA persists. Low levels of passively administered rabies …


Intracellular Bacteria Encode Inhibitory Snare-Like Proteins., Fabienne Paumet, Jordan Wesolowski, Alejandro Garcia-Diaz, Cedric Delevoye, Nathalie Aulner, Howard A Shuman, Agathe Subtil, James E Rothman Oct 2009

Intracellular Bacteria Encode Inhibitory Snare-Like Proteins., Fabienne Paumet, Jordan Wesolowski, Alejandro Garcia-Diaz, Cedric Delevoye, Nathalie Aulner, Howard A Shuman, Agathe Subtil, James E Rothman

Department of Microbiology and Immunology Faculty Papers

Pathogens use diverse molecular machines to penetrate host cells and manipulate intracellular vesicular trafficking. Viruses employ glycoproteins, functionally and structurally similar to the SNARE proteins, to induce eukaryotic membrane fusion. Intracellular pathogens, on the other hand, need to block fusion of their infectious phagosomes with various endocytic compartments to escape from the degradative pathway. The molecular details concerning the mechanisms underlying this process are lacking. Using both an in vitro liposome fusion assay and a cellular assay, we showed that SNARE-like bacterial proteins block membrane fusion in eukaryotic cells by directly inhibiting SNARE-mediated membrane fusion. More specifically, we showed that …


Role Of Mammalian Ecdysoneless In Cell Cycle Regulation., Jun Hyun Kim, Channabasavaiah B. Gurumurthy, Mayumi Naramura, Ying Zhang, Andrew T. Dudley, Lynn Doglio, Hamid Band, Vimla Band Sep 2009

Role Of Mammalian Ecdysoneless In Cell Cycle Regulation., Jun Hyun Kim, Channabasavaiah B. Gurumurthy, Mayumi Naramura, Ying Zhang, Andrew T. Dudley, Lynn Doglio, Hamid Band, Vimla Band

Journal Articles: Genetics, Cell Biology & Anatomy

The Ecdysoneless (Ecd) protein is required for cell-autonomous roles in development and oogenesis in Drosophila, but the function of its evolutionarily conserved mammalian orthologs is not clear. To study the cellular function of Ecd in mammalian cells, we generated Ecd(lox/lox) mouse embryonic fibroblast cells from Ecd floxed mouse embryos. Cre-mediated deletion of Ecd in Ecd(lox/lox) mouse embryonic fibroblasts led to a proliferative block due to a delay in G(1)-S cell cycle progression; this defect was reversed by the introduction of human Ecd. Loss of Ecd led to marked down-regulation of E2F target gene expression. Furthermore, Ecd directly bound to Rb …


Jnk1-Dependent Puma Expression Contributes To Hepatocyte Lipoapoptosis., Sophie C. Cazanave, Justin L. Mott, Nafisa A. Elmi, Steven F. Bronk, Nathan W. Werneburg, Yuko Akazawa, Alisan Kahraman, Sean P. Garrison, Gerard P. Zambetti, Michael R. Charlton, Gregory J. Gores Sep 2009

Jnk1-Dependent Puma Expression Contributes To Hepatocyte Lipoapoptosis., Sophie C. Cazanave, Justin L. Mott, Nafisa A. Elmi, Steven F. Bronk, Nathan W. Werneburg, Yuko Akazawa, Alisan Kahraman, Sean P. Garrison, Gerard P. Zambetti, Michael R. Charlton, Gregory J. Gores

Journal Articles: Biochemistry & Molecular Biology

Free fatty acids (FFA) induce hepatocyte lipoapoptosis by a c-Jun N-terminal kinase (JNK)-dependent mechanism. However, the cellular processes by which JNK engages the core apoptotic machinery during lipotoxicity, especially activation of BH3-only proteins, remain incompletely understood. Thus, our aim was to determine whether JNK mediates induction of BH3-only proteins during hepatocyte lipoapoptosis. The saturated FFA palmitate, but not the monounsaturated FFA oleate, induces an increase in PUMA mRNA and protein levels. Palmitate induction of PUMA was JNK1-dependent in primary murine hepatocytes. Palmitate-mediated PUMA expression was inhibited by a dominant negative c-Jun, and direct binding of a phosphorylated c-Jun containing the …


Effects Of Genistein Following Fractionated Lung Irradiation In Mice., Andrea E Para, Andrea Bezjak, Ivan W T Yeung, Jacob Van Dyk, Richard P Hill Sep 2009

Effects Of Genistein Following Fractionated Lung Irradiation In Mice., Andrea E Para, Andrea Bezjak, Ivan W T Yeung, Jacob Van Dyk, Richard P Hill

Oncology Publications

BACKGROUND AND PURPOSE: This study investigated protection of lung injury by genistein following fractionated doses of radiation and its effect on tumor response.

MATERIAL AND METHODS: C3H/HeJ mice were irradiated (100 kVp X-rays) with 9 fractions of 3.1 Gy over 30 days (approximately equivalent to 10 Gy single dose) and were maintained on a genistein diet ( approximately 10mg/kg). Damage was assessed over 28 weeks in lung cells by a cytokinesis block micronucleus (MN) assay and by changes in breathing rate and histology. Tumor protection was assessed using a colony assay to determine cell survival following in situ irradiation of …


Human Amniotic Fluid Stem Cells Do Not Differentiate Into Dopamine Neurons In Vitro Or After Transplantation In Vivo., Angela E Donaldson, Jingli Cai, Ming Yang, Lorraine Iacovitti Sep 2009

Human Amniotic Fluid Stem Cells Do Not Differentiate Into Dopamine Neurons In Vitro Or After Transplantation In Vivo., Angela E Donaldson, Jingli Cai, Ming Yang, Lorraine Iacovitti

Farber Institute for Neuroscience Faculty Papers

Although embryonic stem (ES) cells can generate dopamine (DA) neurons that are potentially useful as a cell replacement therapy in Parkinson's disease (PD), associated ethical and practical concerns remain major stumbling blocks to their eventual use in humans. In this study, we examined human amniotic fluid stem (hAFS) cells derived from routine amniocenteses for their potential to give rise to DA neurons in vitro and following transplantation into the 6-hydroxydopamine-lesioned rat brain. We show that undifferentiated hAFS cells constitutively expressed mRNAs and proteins typical of stem cells but also cell derivatives of all three germ layers, including neural progenitors/neurons (nestin, …


Characterization Of Two Outer Membrane Proteins, Flgo And Flgp, That Influence Vibrio Cholerae Motility, Raquel M. Martinez, Madushini N. Dharmasena, Thomas J. Kirn, Ronald K. Taylor Sep 2009

Characterization Of Two Outer Membrane Proteins, Flgo And Flgp, That Influence Vibrio Cholerae Motility, Raquel M. Martinez, Madushini N. Dharmasena, Thomas J. Kirn, Ronald K. Taylor

Dartmouth Scholarship

Vibrio cholerae is highly motile by the action of a single polar flagellum. The loss of motility reduces the infectivity of V. cholerae, demonstrating that motility is an important virulence factor. FlrC is the sigma-54-dependent positive regulator of flagellar genes. Recently, the genes VC2206 (flgP) and VC2207 (flgO) were identified as being regulated by FlrC via a microarray analysis of an flrC mutant (D. C. Morris, F. Peng, J. R. Barker, and K. E. Klose, J. Bacteriol. 190:231-239, 2008). FlgP is reported to be an outer membrane lipoprotein required for motility that functions as a colonization factor. The study reported …


Low-Dose Arsenic Compromises The Immune Response To Influenza A Infection In Vivo, Courtney D. Kozul, Kenneth H. Ely, Richard I. Enelow, Joshua W. Hamilton Sep 2009

Low-Dose Arsenic Compromises The Immune Response To Influenza A Infection In Vivo, Courtney D. Kozul, Kenneth H. Ely, Richard I. Enelow, Joshua W. Hamilton

Dartmouth Scholarship

Background:

Arsenic exposure is a significant worldwide environmental health concern. We recently reported that 5-week exposure to environmentally relevant levels (10 and 100 ppb) of As in drinking water significantly altered components of the innate immune response in mouse lung, which we hypothesize is an important contributor to the increased risk of lung disease in exposed human populations.

Objectives:

We investigated the effects of As exposure on respiratory influenza A (H1N1) virus infection, a common and potentially fatal disease.

Methods:

In this study, we exposed C57BL/6J mice to 100 ppb As in drinking water for 5 weeks, followed by intranasal …


Advances In Progenitor Cell Therapy Using Scaffolding Constructs For Central Nervous System Injury, Peter A Walker, Kevin R Aroom, Fernando Jimenez, Shinil K Shah, Matthew T Harting, Brijesh S Gill, Charles S Cox Sep 2009

Advances In Progenitor Cell Therapy Using Scaffolding Constructs For Central Nervous System Injury, Peter A Walker, Kevin R Aroom, Fernando Jimenez, Shinil K Shah, Matthew T Harting, Brijesh S Gill, Charles S Cox

Faculty, Staff and Student Publications

Traumatic brain injury (TBI) is a major cause of morbidity and mortality in the United States. Current clinical therapy is focused on optimization of the acute/subacute intracerebral milieu, minimizing continued cell death, and subsequent intense rehabilitation to ameliorate the prolonged physical, cognitive, and psychosocial deficits that result from TBI. Adult progenitor (stem) cell therapies have shown promise in pre-clinical studies and remain a focus of intense scientific investigation. One of the fundamental challenges to successful translation of the large body of pre-clinical work is the delivery of progenitor cells to the target location/organ. Classically used vehicles such as intravenous and …


Effects Of Genetic Deficiency Of Cyclooxygenase-1 Or Cyclooxygenase-2 On Functional And Histological Outcomes Following Traumatic Brain Injury In Mice, Matthew L. Kelso, Stephen W. Scheff, James R. Pauly, Charles D. Loftin Aug 2009

Effects Of Genetic Deficiency Of Cyclooxygenase-1 Or Cyclooxygenase-2 On Functional And Histological Outcomes Following Traumatic Brain Injury In Mice, Matthew L. Kelso, Stephen W. Scheff, James R. Pauly, Charles D. Loftin

Pharmaceutical Sciences Faculty Publications

BACKGROUND: Neuroinflammation contributes to the pathophysiology of acute CNS injury, including traumatic brain injury (TBI). Although prostaglandin lipid mediators of inflammation contribute to a variety of inflammatory responses, their importance in neuroinflammation is not clear. There are conflicting reports as to the efficacy of inhibiting the enzymes required for prostaglandin formation, cyclooxygenase (COX) -1 and COX-2, for improving outcomes following TBI. The purpose of the current study was to determine the role of the COX isoforms in contributing to pathological processes resulting from TBI by utilizing mice deficient in COX-1 or COX-2.

RESULTS: Following a mild controlled cortical impact injury, …


Distinction Of The Memory B Cell Response To Cognate Antigen Versus Bystander Inflammatory Signals, Micah J. Benson, Raul Elgueta, William Schpero, Michael Molloy, Weijun Zhang, Edward Usherwood, Randolph J. Noelle Aug 2009

Distinction Of The Memory B Cell Response To Cognate Antigen Versus Bystander Inflammatory Signals, Micah J. Benson, Raul Elgueta, William Schpero, Michael Molloy, Weijun Zhang, Edward Usherwood, Randolph J. Noelle

Dartmouth Scholarship

The hypothesis that bystander inflammatory signals promote memory B cell (BMEM) self- renewal and differentiation in an antigen-independent manner is critically evaluated herein. To comprehensively address this hypothesis, a detailed analysis is presented examining the response profiles of B-2 lineage B220 + IgG + BMEM toward cognate protein antigen in comparison to bystander inflammatory signals. After in vivo antigen encounter, quiescent BMEM clonally expand. Surprisingly, proliferating BMEM do not acquire germinal center (GC) B cell markers before generating daughter BMEM and differentiating into plasma cells or form structurally identifiable GCs. In striking contrast to …


Disruption Of Histone Modification And Carm1 Recruitment By Arsenic Represses Transcription At Glucocorticoid Receptor-Regulated Promoters, Fiona D. Barr, Lori J. Krohmer, Joshua W. Hamilton, Lynn A. Sheldon Aug 2009

Disruption Of Histone Modification And Carm1 Recruitment By Arsenic Represses Transcription At Glucocorticoid Receptor-Regulated Promoters, Fiona D. Barr, Lori J. Krohmer, Joshua W. Hamilton, Lynn A. Sheldon

Dartmouth Scholarship

Chronic exposure to inorganic arsenic (iAs) found in the environment is one of the most significant and widespread environmental health risks in the U.S. and throughout the world. It is associated with a broad range of health effects from cancer to diabetes as well as reproductive and developmental anomalies. This diversity of diseases can also result from disruption of metabolic and other cellular processes regulated by steroid hormone receptors via aberrant transcriptional regulation. Significantly, exposure to iAs inhibits steroid hormone-mediated gene activation. iAs exposure is associated with disease, but is also used therapeutically to treat specific cancers complicating an understanding …


Calcium Homeostasis And Cone Signaling Are Regulated By Interactions Between Calcium Stores And Plasma Membrane Ion Channels., Tamas Szikra, Peter Barabas, Theodore M. Bartoletti, Wei Huang, Abram Akopian, Wallace B. Thoreson, David Krizaj Aug 2009

Calcium Homeostasis And Cone Signaling Are Regulated By Interactions Between Calcium Stores And Plasma Membrane Ion Channels., Tamas Szikra, Peter Barabas, Theodore M. Bartoletti, Wei Huang, Abram Akopian, Wallace B. Thoreson, David Krizaj

Journal Articles: Ophthalmology

Calcium is a messenger ion that controls all aspects of cone photoreceptor function, including synaptic release. The dynamic range of the cone output extends beyond the activation threshold for voltage-operated calcium entry, suggesting another calcium influx mechanism operates in cones hyperpolarized by light. We have used optical imaging and whole-cell voltage clamp to measure the contribution of store-operated Ca(2+) entry (SOCE) to Ca(2+) homeostasis and its role in regulation of neurotransmission at cone synapses. Mn(2+) quenching of Fura-2 revealed sustained divalent cation entry in hyperpolarized cones. Ca(2+) influx into cone inner segments was potentiated by hyperpolarization, facilitated by depletion of …


Mechanisms Of Primary Axonal Damage In A Viral Model Of Multiple Sclerosis., Jayasri Das Sarma, Lawrence C. Kenyon, Susan T. Hingley, Kenneth S. Shindler Aug 2009

Mechanisms Of Primary Axonal Damage In A Viral Model Of Multiple Sclerosis., Jayasri Das Sarma, Lawrence C. Kenyon, Susan T. Hingley, Kenneth S. Shindler

Department of Neurology Faculty Papers

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the CNS. Recent studies have demonstrated that significant axonal injury also occurs in MS patients and correlates with neurological dysfunction, but it is not known whether this neuronal damage is a primary disease process, or occurs only secondary to demyelination. In the current studies, neurotropic strains of mouse hepatitis virus (MHV) that induce meningitis, encephalitis, and demyelination in the CNS, an animal model of MS, were used to evaluate mechanisms of axonal injury. The pathogenic properties of genetically engineered isogenic spike protein recombinant demyelinating and nondemyelinating strains of MHV were compared. …


Uncoupling Scavenger Receptor A-Mediated Phagocytosis Of Bacteria From Endotoxic Shock Resistance, Eyal Amiel, Julie L. Acker, Ryan M. Collins, Brent Berwin Aug 2009

Uncoupling Scavenger Receptor A-Mediated Phagocytosis Of Bacteria From Endotoxic Shock Resistance, Eyal Amiel, Julie L. Acker, Ryan M. Collins, Brent Berwin

Dartmouth Scholarship

Unresolved infection by gram-negative bacteria can result in the potentially lethal condition known as endotoxic shock, whereby uncontrolled inflammation can lead to multiple organ failure and death of the infected host. Previous results have demonstrated that animals deficient in class A scavenger receptor (SRA), a trafficking receptor for bacteria and bacterium-derived molecules, are more susceptible to endotoxic shock. This has been proposed to be a result of impaired SRA-dependent phagocytic clearance of bacteria resulting in stronger proinflammatory stimuli. In this report, we test the hypothesis that there is an obligate reciprocal relationship between SRA-mediated phagocytosis of bacteria and susceptibility to …


Expression Of Cpi-17 In Smooth Muscle During Embryonic Development And In Neointimal Lesion Formation., Jee In Kim, Garbo D Young, Li Jin, Avril V Somlyo, Masumi Eto Aug 2009

Expression Of Cpi-17 In Smooth Muscle During Embryonic Development And In Neointimal Lesion Formation., Jee In Kim, Garbo D Young, Li Jin, Avril V Somlyo, Masumi Eto

Department of Molecular Physiology and Biophysics Faculty Papers

Ca(2+) sensitivity of smooth muscle (SM) contraction is determined by CPI-17, an inhibitor protein for myosin light chain phosphatase (MLCP). CPI-17 is highly expressed in mature SM cells, but the expression level varies under pathological conditions. Here, we determined the expression of CPI-17 in embryonic SM tissues and arterial neointimal lesions using immunohistochemistry. As seen in adult animals, the predominant expression of CPI-17 was detected at SM tissues on mouse embryonic sections, whereas MLCP was ubiquitously expressed. Compared with SM alpha-actin, CPI-17 expression doubled in arterial SM from embryonic day E10 to E14. Like SM alpha-actin and other SM marker …