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Sphingosine-1-Phosphate-Mediated Mobilization Of Hematopoietic Stem/Progenitor Cells During Intravascular Hemolysis Requires Attenuation Of Sdf-1-Cxcr4 Retention Signaling In Bone Marrow, Kasia Mierzejewska, Yuri M. Klyachkin, Janina Ratajczak, Ahmed Abdel-Latif, Magda Kucia, Mariusz Z. Ratajczak

Saha Cardiovascular Research Center Faculty Publications

Sphingosine-1-phosphate (S1P) is a crucial chemotactic factor in peripheral blood (PB) involved in the mobilization process and egress of hematopoietic stem/progenitor cells (HSPCs) from bone marrow (BM). Since S1P is present at high levels in erythrocytes, one might assume that, by increasing the plasma S1P level, the hemolysis of red blood cells would induce mobilization of HSPCs. To test this assumption, we induced hemolysis in mice by employing phenylhydrazine (PHZ). We observed that doubling the S1P level in PB from damaged erythrocytes induced only a marginally increased level of mobilization. However, if mice were exposed to PHZ together with the …

Beyond Perceptual Expertise: Revisiting The Neural Substrates Of Expert Object Recognition, Assaf Harel, Dwight J. Kravitz, Chris I. Baker

Psychology Faculty Publications

Real-world expertise provides a valuable opportunity to understand how experience shapes human behavior and neural function. In the visual domain, the study of expert object recognition, such as in car enthusiasts or bird watchers, has produced a large, growing, and often-controversial literature. Here, we synthesize this literature, focusing primarily on results from functional brain imaging, and propose an interactive framework that incorporates the impact of high-level factors, such as attention and conceptual knowledge, in supporting expertise. This framework contrasts with the perceptual view of object expertise that has concentrated largely on stimulus-driven processing in visual cortex. One prominent version of …

Inflammatory Cytokine Gene Expression In Mesenteric Adipose Tissue During Acute Experimental Colitis, William Conan Mustain, Marlene E. Starr, Joseph Daniel Valentino, Donald A. Cohen, Daiki Okamura, Chi Wang, B. Mark Evers, Hiroshi Saito

Markey Cancer Center Faculty Publications

BACKGROUND: Production of inflammatory cytokines by mesenteric adipose tissue (MAT) has been implicated in the pathogenesis of inflammatory bowel disease (IBD). Animal models of colitis have demonstrated inflammatory changes within MAT, but it is unclear if these changes occur in isolation or as part of a systemic adipose tissue response. It is also unknown what cell types are responsible for cytokine production within MAT. The present study was designed to determine whether cytokine production by MAT during experimental colitis is depot-specific, and also to identify the source of cytokine production within MAT.

METHODS: Experimental colitis was induced in 6-month-old C57BL/6 …

The Toxoplasma Gondii Cyst Wall Protein Cst1 Is Critical For Cyst Wall Integrity And Promotes Bradyzoite Persistence, Tadakimi Tomita, David J. Bzik, Yan Fen Ma, Barbara A. Fox

Dartmouth Scholarship

Toxoplasma gondii infects up to one third of the world's population. A key to the success of T. gondii as a parasite is its ability to persist for the life of its host as bradyzoites within tissue cysts. The glycosylated cyst wall is the key structural feature that facilitates persistence and oral transmission of this parasite. Because most of the antibodies and reagents that recognize the cyst wall recognize carbohydrates, identification of the components of the cyst wall has been technically challenging. We have identified CST1 (TGME49_064660) as a 250 kDa SRS (SAG1 related sequence) domain protein with a large …

A Mechanism Linking Id2-Tgfβ Crosstalk To Reversible Adaptive Plasticity In Neuroblastoma, Lina Chakrabarti, Bi-Dar Wang, Norman H. Lee, Anthony D. Sandler

Pharmacology and Physiology Faculty Publications

The ability of high-risk neuroblastoma to survive unfavorable growth conditions and multimodal therapy has produced an elusive childhood cancer with remarkably poor prognosis. A novel phenomenon enabling neuroblastoma to survive selection pressure is its capacity for reversible adaptive plasticity. This plasticity allows cells to transition between highly proliferative anchorage dependent (AD) and slow growing, anoikis-resistant anchorage independent (AI) phenotypes. Both phenotypes are present in established mouse and human tumors. The differential gene expression profile of the two cellular phenotypes in the mouse Neuro2a cell line delineated pathways of proliferation in AD cells or tyrosine kinase activation/ apoptosis inhibition in AI …

Septins Of Platyhelminths: Identification, Phylogeny, Expression And Localization Among Developmental Stages Of Schistosoma Mansoni, Ana E. Zeraik, Gabriel Rinaldi, Victoria H. Mann, Anastas Popratiloff, Ana P.U. Araujo, Ricardo Demarco, Paul J. Brindley

Microbiology, Immunology, and Tropical Medicine Faculty Publications

Septins are a family of eukaryotic GTP binding proteins conserved from yeasts to humans. Originally identified in mutants of budding yeast, septins participate in diverse cellular functions including cytokinesis, organization of actin networks, cell polarity, vesicle trafficking and many others. Septins assemble into heteroligomers to form filaments and rings. Here, four septins of Schistosoma mansoni are described, which appear to be conserved within the phylum Platyhelminthes. These orthologues were related to the SEPT5, SEPT10 and SEPT7 septins of humans, and hence we have termed the schistosome septins SmSEPT5, SmSEPT10, SmSEPT7.1 and SmSEPT7.2. Septin transcripts were detected throughout the developmental cycle …

Differential Effects Of Endocannabinoid Catabolic Inhibitors On Opioid Withdrawal In Mice, Thomas Gamage

Theses and Dissertations

The effects of cannabinoids in reducing somatic signs of opioid withdrawal have been known for some time. In morphine dependent rodents, opioid withdrawal following precipitation with the mu opioid antagonist naloxone elicits robust withdrawal behaviors including jumps, paw flutters, head shakes, diarrhea and weight loss. Delta-9-tetrahydrocannabinol has been shown to reduce this opioid withdrawal in mice via activation of the cannabinoid type-1 (CB1) receptor and recently it has been shown that inhibition of the catabolic enzymes for endocannabinoids also reduce somatic signs of opioid withdrawal. Specifically, inhibition the enzyme fatty acid amide hydrolase (FAAH), the catabolic enzyme for the endocannabinoid …

Hypoxia/Aglycemia-Induced Endothelial Barrier Dysfunction And Tight Junction Protein Downregulation Can Be Ameliorated By Citicoline, Xiaotang Ma, Huiting Zhang, Qunwen Pan, Yuhui Zhao, Ji Chen, Yanfang Chen

Pharmacology and Toxicology Faculty Publications

This study explores the effect of citicoline on the permeability and expression of tight junction proteins (TJPs) in endothelial cells under hypoxia/aglycemia conditions. Hypoxia or oxygen and glucose deprivation (OGD) was utilized to induce endothelial barrier breakdown model on human umbilical vein endothelial cells (HUVECs) and mouse brain microvascular endothelial cells (bEnd.3s). The effect of citicoline on endothelial barrier breakdown models was determined at either low or high concentrations. FITC-Dextran flux was used to examine the endothelial permeability. The expression of TJPs was measured by immunofluorescence, Real-time PCR and Western Blot methods. Results showed that hypoxia or OGD increased the …

Impact Of Oxidative Stress On Female Fertility., Tasha Harris

Undergraduate Honors Theses

This study examined nutritional status and fecundity of women and was approved for patient enrollment by the ETSU Institutional Review Board (IRB). Once enrolled, participants filled out two food frequency questionnaires (FFQ, fruit/vegetable intake, fat intake), self-reported anthropometric data, and had one 5 mL vacutainer of whole blood (EDTA) collected for measures of oxidative stress (OS), coenzyme Q10 level, and fatty acid profile of the red blood cell (RBC) membrane. Participants were either designated to the case group (13 women experiencing fertility problems and an anti-mullerian hormone level of 1 ng/ml or less (AMH, <1 ng/mL)) or the control group (13 women experiencing normal ovulation cycles and no evidence of polycystic disease). This study hypothesized that the case group would have poorer plasma antioxidant status, consume more dietary saturated fat and have lower levels of omega-3 and higher levels of omega-6 fatty acids in the RBC membrane. Results showed that case participants had significantly higher body mass index (BMI) when graduating from high school, BMI upon enrollment in the study, and trended to gain more weight since high school. Antioxidant status of the plasma tended to be higher for the case group. This result was surprising as case participants consumed significantly fewer servings of fruits and vegetables (sources of antioxidants) than control subjects. FFQ results indicated that case participants consumed significantly higher amounts of total fat (g), saturated fat (g), unsaturated fat (g), and their diets had a higher dietary fat percent. No significant differences were noted in the individual fatty acids isolated from the RBC membrane or in calculated ratios of fatty acid between case and control groups. The fatty acid profile from RBC membranes are in agreement with self-reported fat intake from FFQ data and may provide a rationale for no differences observed between the two groups.

Defects In Synapse Structure And Function Precede Motor Neuron Degeneration In Drosophila Models Of Fus-Related Als., Mohammad Shahidullah, Sylvain J Le Marchand, Hong Fei, Jiaming Zhang, Udai Bhan Pandey, Matthew B. Dalva, Piera Pasinelli, Irwin B. Levitan

Department of Neuroscience Faculty Papers

Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease that leads invariably to fatal paralysis associated with motor neuron degeneration and muscular atrophy. One gene associated with ALS encodes the DNA/RNA-binding protein Fused in Sarcoma (FUS). There now exist two Drosophila models of ALS. In one, human FUS with ALS-causing mutations is expressed in fly motor neurons; in the other, the gene cabeza (caz), the fly homolog of FUS, is ablated. These FUS-ALS flies exhibit larval locomotor defects indicative of neuromuscular dysfunction and early death. The locus and site of initiation of this neuromuscular dysfunction remain unclear. We show here …

Use Of Irf-3 And/Or Irf-7 Knockout Mice To Study Viral Pathogenesis: Lessons From A Murine Retrovirus-Induced Aids Model, Megan A. O'Connor, William R. Green

Dartmouth Scholarship

Interferon regulatory factor (IRF) regulation of the type I interferon response has not been extensively explored in murine retroviral infections. IRF-3(-/-) and select IRF-3/7(-/-) mice were resistant to LP-BM5-induced pathogenesis. However, further analyses strongly suggested that resistance could be attributed to strain 129-specific contamination of the known retrovirus resistance gene Fv1. Therefore, caution should be taken when interpreting phenotypes observed in these knockout mice, as strain 129-derived genetic polymorphisms may explain observed differences.

Impact Of Noise On Molecular Network Inference, Radhakrishnan Nagarajan, Marco Scutari

Biostatistics Faculty Publications

Molecular entities work in concert as a system and mediate phenotypic outcomes and disease states. There has been recent interest in modelling the associations between molecular entities from their observed expression profiles as networks using a battery of algorithms. These networks have proven to be useful abstractions of the underlying pathways and signalling mechanisms. Noise is ubiquitous in molecular data and can have a pronounced effect on the inferred network. Noise can be an outcome of several factors including: inherent stochastic mechanisms at the molecular level, variation in the abundance of molecules, heterogeneity, sensitivity of the biological assay or measurement …

In Vivo Bioluminescence Imaging To Evaluate Systemic And Topical Antibiotics Against Community-Acquired Methicillin-Resistant Staphylococcus Aureus-Infected Skin Wounds In Mice, Yi Guo, Romela Irene Ramos, John S. Cho, Niles P. Donegan, Ambrose L. Cheung, Lloyd S. Miller

Dartmouth Scholarship

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) frequently causes skin and soft tissue infections, including impetigo, cellulitis, folliculitis, and infected wounds and ulcers. Uncomplicated CA-MRSA skin infections are typically managed in an outpatient setting with oral and topical antibiotics and/or incision and drainage, whereas complicated skin infections often require hospitalization, intravenous antibiotics, and sometimes surgery. The aim of this study was to devel

Layered Long Term Co-Culture Of Hepatocytes And Endothelial Cells On A Transwell Membrane: Toward Engineering The Liver Sinusoid, Young Bok (Abraham) Kang, Siddhartha Rawat, Joseph Cirillo, Michael Bouchard, Hongseok (Moses) Noh

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

This paper presents a novel liver model that mimics the liver sinusoid where most liver activities occur. A key aspect of our current liver model is a layered co-culture of primary rat hepatocytes (PRHs) and primary rat liver sinusoidal endothelial cells (LSECs) or bovine aortic endothelial cells (BAECs) on a transwell membrane. When a layered co-culture was attempted with a thin matrigel layer placed between hepatocytes and endothelial cells to mimic the Space of Disse, the cells did not form completely separated monolayers. However, when hepatocytes and endothelial cells were cultured on the opposite sides of a transwell membrane, PRHs …

Early Chronic Low-Level Lead Exposure Produces Glomerular Hypertrophy In Young C57bl/6j Mice, Christina Sobin, John Basgen

Selected Works Temporary Series

Early chronic lead exposure continues to pose serious health risks for children, particularly those living in lower socioeconomic environments. This study examined effects on developing glomeruli in young C57BL/6J mice exposed to low (30 ppm), higher (330 ppm) or no lead via dams’ drinking water from birth to sacrifice on post-natal day 28. Low-level lead exposed mice [BLL mean (SD); 3.19 (0.70) µg/dL] had an increase in glomerular volume but no change in podocyte number compared to control mice [0.03 (0.01) µg/dL]. Higher-level lead exposed mice [14.68 (2.74) µg/dL] had no change in either glomerular volume or podocyte number. The …

Phosphate Esters, Thiophosphate Esters And Metal Thiophosphates As Lubricant Additives, David W. Johnson, John E. Hils

Chemistry Faculty Publications

Phosphate esters, thiophosphate esters and metal thiophosphates have been used as lubricant additives for over 50 years. While their use has been extensive, a detailed knowledge of how they work has been a much more recent development. In this paper, the use of phosphate esters and thiophosphate esters as anti-wear or extreme pressure additives is reviewed with an emphasis on their mechanism of action. The review includes the use of alkyl phosphates, triaryl phosphates and metal containing thiophosphate esters. The mechanisms of these materials interacting with a range of iron and steel based bearing material are examined.

Development Of Novel Antifungal Peptides Based On A Natural Model Of Histatin-5 Peptide, Duy Tu Nguyen

Graduate Theses and Dissertations

Our research group is working toward the development of novel antifungal peptides based on a natural model of peptide histatin-5. Histatin-5 is found in human saliva and known to protect our body against oral infections by Candida species. Candidiasis, or an infection caused by Candida species, is considered one of the most medically important fungal infections worldwide. Blood stream infections caused by Candida species are the fourth leading cause of hospital-acquired fungal infections that is associated with high mortality rates and high costs of treatment. This study investigated the modes of action of histatin-5 with the use of one 16-mer …

Cxcr2 Expression In Tumor Cells Is A Poor Prognostic Factor And Promotes Invasion And Metastasis In Lung Adenocarcinoma, Erminia Massarelli

Dissertations and Theses (Open Access)

CXC chemokine receptor 2 (CXCR2) is a G-protein coupled receptor which mediates signaling by binding to CXC chemokines CXCL1-3 and 5-8. In non-small cell lung cancer CXCR2 has been studied mainly in stromal cells and is known to increase tumor inflammation and angiogenesis. However, there is controversial data in the literature about CXCR2 expression in tumor cells and its role in the tumor microenvironment. We hypothesized that tumoral expression of CXCR2 and its ligands promote tumor invasion and metastasis in non-small cell lung cancer. The effect of CXCR2 expression on tumor cells was studied using stable knockdown clones derived from …

Determinants Of Upper Genital Tract Complications In A Chlamydial Urogenital Mouse Model, Enitra N. Jones

Theses and Dissertations (ETD)

Genital Chlamydia trachomatis infection is a major public health concern. Chlamydia is the most commonly reported infection in the United States and the most common bacterial sexually transmitted infection worldwide. Unrecognized infection endangers female reproductive health by serious complications such as Pelvic Inflammatory Disease, ectopic pregnancy, and involuntary infertility. Widespread Chlamydia control programs were implemented more than two decades ago to improve women's reproductive health but, despite initial success, the number of chlamydial infections reported have increased.

One of the hypotheses put forth to explain increased chlamydial reporting suggests that a longterm caveat of control initiatives is interference with the …

Enhanced Pancreatic Beta-Cells Proliferation And Functionality, Hanan Abdulaziz Alismail

Graduate Theses and Dissertations

Biologically functional beta-cells proliferate at an extremely low rate with limited turnover capacity. This cellular property hinders cell-based therapy for clinical applications. Many attempts have been made to develop techniques that allow large quantities of production of clinically relevant islet β-cells in vitro. A line of studies demonstrates that functional beta-cells can proliferate under certain circumstances, providing hope for generating and expanding these cells in vitro and transplanting them into the recipient. In this study, we showed that a membrane substrate offers a better niche for beta cell proliferation and insulin secretion. Mouse beta cells were grown on a tissue …

Sympathetic Nerve Modulation Of Joint Pathology In Adjuvant-Induced Arthritis, Carlo Anthony Wood

Loma Linda University Electronic Theses, Dissertations & Projects

Background: There is increasing data suggesting a net increase in sympathetic tone plays an important role in rheumatoid arthritis. Several studies have reported altered distribution and density of autonomic nerves in patients with rheumatoid arthritis and animal models for the disease. This provides anatomical evidence that supports a neurally-mediated drive in inflammation and joint destruction. Methods: Adult rats were injected with complete Freund’s adjuvant. At 12 days post immunization, animals were randomly placed into a drug treatment group (SH1293, which interacts with - and ß2-ARs), an adjuvant arthritic group, or a control group. These animals were sacrificed at 14, 21, …

Expression And Function Of Ca2+-Activated K+ Channels In Uterine Arteries, Ronghui Zhu

Loma Linda University Electronic Theses, Dissertations & Projects

Chronic hypoxia during pregnancy is one of the most common insults to the maternal cardiovascular system and fetal development, and is associated with increased uterine vascular tone and heightened risk of preeclampsia and fetal intrauterine growth restriction (IUGR). The present study tested the hypothesis that calcium-activated potassium (KCa) channels play an essential role in uterine vascular adaptation to pregnancy, which is inhibited by chronic hypoxia during gestation. Uterine arteries (UAs) were isolated from nonpregnant ewes (NPUAs) and near-term pregnant ewes (PUAs) that had been maintained at sea level (~300 m) or exposed to high altitude (3,801 m) for 110 days. …

Radiosensitization Of Head & Neck Carcinoma Cells By Linifanib, A Receptor Tyrosine Kinase Inhibitor, Heng-Wei Hsu

Loma Linda University Electronic Theses, Dissertations & Projects

Tumor angiogenesis is a hallmark of advanced cancers and promotes invasion and metastasis. Over 90% of head and neck squamous cell carcinomas (HNSCC) express angiogenic factors such as vascular endothelial growth factor (VEGF). Since radiotherapy is one of the most commonly used treatments for HNSCC, it is imperative to identify the interactions between antiangiogenic therapy and radiotherapy, and to develop combination therapy to improve clinical outcome. The mechanisms between antiangiogenic agents and ionizing radiation are complicated and involve many interactions between the vasculature, tumor stroma and tumor cells. The proliferation and metastasis of tumor cells rely on angiogenesis/blood vessel formation. …

Staphylococcus Aureus Sara Regulates Inflammation And Colonization During Central Nervous System Biofilm Formation, Jessica N. Snowden, Matthew K. Beaver, Karen Beenken, Alexander R. Horswill, Tammy L. Kielian

Journal Articles: Pediatrics

Infection is a frequent and serious complication following the treatment of hydrocephalus with CSF shunts, with limited therapeutic options because of biofilm formation along the catheter surface. Here we evaluated the possibility that the sarA regulatory locus engenders S. aureus more resistant to immune recognition in the central nervous system (CNS) based on its reported ability to regulate biofilm formation. We utilized our established model of CNS catheter-associated infection, similar to CSF shunt infections seen in humans, to compare the kinetics of bacterial titers, cytokine production and inflammatory cell influx elicited by wild type S. aureus versus an isogenic sarA …

A Novel Mechanism Of Enhanced Susceptibility To Bacterial Pneumonia In Influenza-Infected Hosts, Hazem Elsayed Ghoneim

Theses and Dissertations (ETD)

Viruses such as influenza suppress host immune function by a variety of methods. This may result in a significant morbidity through several pathways, including facilitation of secondary bacterial pneumonia from pathogens such as Streptococcus pneumoniae. Lungresident alveolar macrophages (AMs) act as the first line of innate cellular immunity against respiratory bacterial pathogens, including pneumococcus. Therefore, they represent an attractive target for study Before investigating the impact of influenza infection on resident AMs, we first characterized different subsets of lung-resident macrophages in naïve mice using a novel in vivo labeling approach in conjunction with multicolor flow cytometric analysis and confocal microscopic …

Attenuation Of Parenteral Nutritionassociated Liver Disease By Omega-3 Long-Chain Polyunsaturated Fatty Acids, Emma Monique Tillman

Theses and Dissertations (ETD)

No abstract provided.

Erg11-Mediated Azole Resistance In Candida Albicans, Stephanie Ann Flowers

Theses and Dissertations (ETD)

Although many medically important Candida species are commensal to the gut or colonizers of the skin, these organisms have the propensity to cause disease in the event of a waning immune system. Clinical manifestations of infections with Candida species can range from superficial mucosal infections to deep organ involvement usually resulting from haematogenous spread of infection. Despite significant progress made in the management of patients with fungal infections, the emergence of antifungal resistant clinical isolates creates significant problem in regards to antifungal prophylaxis and empirical treatment strategies. Antifungal resistance is associated with high mortality rates and hefty medical costs. The …

Regulation Of Secretory Phospholipase A2 By Thyroid Hormone, Pragya Sharma

Theses and Dissertations (ETD)

Rationale: Low grade inflammation has been correlated with elevated risk of hepatic steatosis and atherosclerosis. Secretory phospholipase A2 group IIA (PLA2g2a) enhances the progression of several chronic inflammatory diseases including arthritis and atherosclerosis. The potential linkage of hypothyroidism with inflammation led us to examine the modulation of sPLA2 expression by thyroid hormone (T3) in liver.

Objective: Most of the studies of phospholipase A2 group IIA (PLA2g2a) have been conducted with macrophages and vascular smooth muscle cells with regard to atherosclerosis. The liver is one of the major contributors to the total pool of extracellular PLA2g2a. The aim of the present …

Toll-Like Receptors 2 And 9 Are Important For Innate Immune Cell Activation And Recruitment In Hypersensitivity Pneumonitis, Kelly J. Andrews

Theses and Dissertations (ETD)

Hypersensitivity pneumonitis (HP) is an interstitial lung disease caused by repeated inhalation of environmental antigens. The disease is characterized by alveolitis and granuloma formation; however, some patients develop chronic HP (CHP), a restrictive lung disease characterized by fibrosis. Previous studies revealed that neutrophils are recruited into the lung via a MyD88- dependent pathway and regulate disease severity through cytokine production. Toll-like receptors (TLRs) 2 and 9 recognize conserved molecular patterns present in bacteria, and signal through the adaptor molecule MyD88. The goal of my project is to investigate the role of TLRs 2 and 9 in the pathogenesis of HP …

Full-Gestational Exposure To Nicotine And Ethanol Results In Long-Term Dysregulation In The Ventral Tegmental Area, Emily Elizabeth Roguski

Theses and Dissertations (ETD)

Nicotine is considered a gateway drug for other drugs of abuse. The majority of smokers that begin smoking in adolescence, continue into adulthood. Multiple factors have been linked with smoking initiation, including maternal smoking. Drug exposure during pregnancy has long been suspected to exert deleterious effects on the fetal brain. Concurrent use of smoking and drinking alcohol throughout pregnancy is an all too frequent occurrence in the human population especially in disadvantaged and younger women.

The present study investigated the potential contributing factors for the enhanced nicotine selfadministration as seen in offspring with gestational exposure to nicotine and ethanol (Nic+EtOH).* …