24 results on '"Bauer KM"'
Search Results
2. RAB27B controls palmitoylation-dependent NRAS trafficking and signaling in myeloid leukemia.
- Author
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Ren JG, Xing B, Lv K, O'Keefe RA, Wu M, Wang R, Bauer KM, Ghazaryan A, Burslem GM, Zhang J, O'Connell RM, Pillai V, Hexner EO, Philips MR, and Tong W
- Subjects
- Humans, Animals, Mice, Proteomics, Signal Transduction, Mitogen-Activated Protein Kinase Kinases, Membrane Proteins genetics, GTP Phosphohydrolases, Lipoylation, Leukemia, Myeloid
- Abstract
RAS mutations are among the most prevalent oncogenic drivers in cancers. RAS proteins propagate signals only when associated with cellular membranes as a consequence of lipid modifications that impact their trafficking. Here, we discovered that RAB27B, a RAB family small GTPase, controlled NRAS palmitoylation and trafficking to the plasma membrane, a localization required for activation. Our proteomic studies revealed RAB27B upregulation in CBL- or JAK2-mutated myeloid malignancies, and its expression correlated with poor prognosis in acute myeloid leukemias (AMLs). RAB27B depletion inhibited the growth of CBL-deficient or NRAS-mutant cell lines. Strikingly, Rab27b deficiency in mice abrogated mutant but not WT NRAS-mediated progenitor cell growth, ERK signaling, and NRAS palmitoylation. Further, Rab27b deficiency significantly reduced myelomonocytic leukemia development in vivo. Mechanistically, RAB27B interacted with ZDHHC9, a palmitoyl acyltransferase that modifies NRAS. By regulating palmitoylation, RAB27B controlled c-RAF/MEK/ERK signaling and affected leukemia development. Importantly, RAB27B depletion in primary human AMLs inhibited oncogenic NRAS signaling and leukemic growth. We further revealed a significant correlation between RAB27B expression and sensitivity to MEK inhibitors in AMLs. Thus, our studies presented a link between RAB proteins and fundamental aspects of RAS posttranslational modification and trafficking, highlighting future therapeutic strategies for RAS-driven cancers.
- Published
- 2023
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3. miRNA-1 promotes acute myeloid leukemia cell pathogenesis through metabolic regulation.
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Ghazaryan A, Wallace JA, Tang WW, Barba C, Lee SH, Bauer KM, Nelson MC, Kim CN, Stubben C, Voth WP, Rao DS, and O'Connell RM
- Abstract
Acute myeloid leukemia (AML) is a heterogeneous and deadly disease characterized by uncontrolled expansion of malignant blasts. Altered metabolism and dysregulated microRNA (miRNA) expression profiles are both characteristic of AML. However, there is a paucity of studies exploring how changes in the metabolic state of the leukemic cells regulate miRNA expression leading to altered cellular behavior. Here, we blocked pyruvate entry into mitochondria by deleting the Mitochondria Pyruvate Carrier (MPC1) gene in human AML cell lines, which decreased Oxidative Phosphorylation (OXPHOS). This metabolic shift also led to increased expression of miR-1 in the human AML cell lines tested. AML patient sample datasets showed that higher miR-1 expression correlates with reduced survival. Transcriptional and metabolic profiling of miR-1 overexpressing AML cells revealed that miR-1 increased OXPHOS, along with key metabolites that fuel the TCA cycle such as glutamine and fumaric acid. Inhibition of glutaminolysis decreased OXPHOS in miR-1 overexpressing MV4-11 cells, highlighting that miR-1 promotes OXPHOS through glutaminolysis. Finally, overexpression of miR-1 in AML cells exacerbated disease in a mouse xenograft model. Together, our work expands current knowledge within the field by uncovering novel connections between AML cell metabolism and miRNA expression that facilitates disease progression. Further, our work points to miR-1 as a potential new therapeutic target that may be used to disrupt AML cell metabolism and thus pathogenesis in the clinic., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Ghazaryan, Wallace, Tang, Barba, Lee, Bauer, Nelson, Kim, Stubben, Voth, Rao and O’Connell.)
- Published
- 2023
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4. CD11c+ myeloid cell exosomes reduce intestinal inflammation during colitis.
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Bauer KM, Nelson MC, Tang WW, Chiaro TR, Brown DG, Ghazaryan A, Lee SH, Weis AM, Hill JH, Klag KA, Tran VB, Thompson JW, Ramstead AG, Monts JK, Marvin JE, Alexander M, Voth WP, Stephens WZ, Ward DM, Petrey AC, Round JL, and O'Connell RM
- Subjects
- Animals, Inflammatory Bowel Diseases immunology, Intestines immunology, Lipids, Mammals genetics, Mammals immunology, Mice, MicroRNAs immunology, Monomeric GTP-Binding Proteins immunology, NLR Family, Pyrin Domain-Containing 3 Protein immunology, TNF Receptor-Associated Factor 6 immunology, CD11 Antigens genetics, CD11 Antigens immunology, Colitis genetics, Colitis immunology, Exosomes genetics, Exosomes immunology, Inflammation genetics, Inflammation immunology, Myeloid Cells immunology
- Abstract
Intercellular communication is critical for homeostasis in mammalian systems, including the gastrointestinal (GI) tract. Exosomes are nanoscale lipid extracellular vesicles that mediate communication between many cell types. Notably, the roles of immune cell exosomes in regulating GI homeostasis and inflammation are largely uncharacterized. By generating mouse strains deficient in cell-specific exosome production, we demonstrate deletion of the small GTPase Rab27A in CD11c+ cells exacerbated murine colitis, which was reversible through administration of DC-derived exosomes. Profiling RNAs within colon exosomes revealed a distinct subset of miRNAs carried by colon- and DC-derived exosomes. Among antiinflammatory exosomal miRNAs, miR-146a was transferred from gut immune cells to myeloid and T cells through a Rab27-dependent mechanism, targeting Traf6, IRAK-1, and NLRP3 in macrophages. Further, we have identified a potentially novel mode of exosome-mediated DC and macrophage crosstalk that is capable of skewing gut macrophages toward an antiinflammatory phenotype. Assessing clinical samples, RAB27A, select miRNAs, and RNA-binding proteins that load exosomal miRNAs were dysregulated in ulcerative colitis patient samples, consistent with our preclinical mouse model findings. Together, our work reveals an exosome-mediated regulatory mechanism underlying gut inflammation and paves the way for potential use of miRNA-containing exosomes as a novel therapeutic for inflammatory bowel disease.
- Published
- 2022
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5. miR-aculous new avenues for cancer immunotherapy.
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Tang WW, Bauer KM, Barba C, Ekiz HA, and O'Connell RM
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- Humans, Immunotherapy, MicroRNAs, Neoplasms drug therapy, Neoplasms therapy
- Abstract
The rising toll of cancer globally necessitates ingenuity in early detection and therapy. In the last decade, the utilization of immune signatures and immune-based therapies has made significant progress in the clinic; however, clinical standards leave many current and future patients without options. Non-coding RNAs, specifically microRNAs, have been explored in pre-clinical contexts with tremendous success. MicroRNAs play indispensable roles in programming the interactions between immune and cancer cells, many of which are current or potential immunotherapy targets. MicroRNAs mechanistically control a network of target genes that can alter immune and cancer cell biology. These insights provide us with opportunities and tools that may complement and improve immunotherapies. In this review, we discuss immune and cancer cell-derived miRNAs that regulate cancer immunity and examine miRNAs as an integral part of cancer diagnosis, classification, and therapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Tang, Bauer, Barba, Ekiz and O’Connell.)
- Published
- 2022
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6. No small matter: emerging roles for exosomal miRNAs in the immune system.
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Bauer KM, Round JL, and O'Connell RM
- Subjects
- Humans, Macrophages metabolism, RNA, Messenger genetics, Exosomes genetics, Exosomes metabolism, Extracellular Vesicles metabolism, Immune System, MicroRNAs genetics
- Abstract
Extracellular communication is critical to the function of an organism. Exosomes, small lipid extracellular vesicles, have been recently appreciated to participate in this vital function. Within these vesicles lie critical bioactive molecules including mRNAs, proteins, and a plethora of noncoding RNAs, including microRNAs (miRNAs). Exosomal miRNAs have been shown to be produced by, trafficked between, and function in many distinct donor and recipient cell types, including cells of the immune system. For instance, loss of these critical communicators can alter the cellular response to endotoxin, and when tumor cells lose the ability to secrete these vesicles, the immune system is able to effectively suppress tumor growth. This review will highlight key findings on the known communication to and from the immune system, highlighting exosomal miRNA research in macrophages, dendritic cells, B lymphocytes, and T cells. Additionally, we will focus on three major areas of exosomal studies that involve immune responses including mucosal barriers, adipose tissue, and the tumor microenvironment. These environments are heterogeneous and dynamic, and rapidly respond to the microbiota, metabolic shifts, and immunotherapies, respectively. It is clear that exosomal miRNAs play pivotal roles in regulating cross-talk between cells in these tissues, and this represents a novel layer of cellular communication proving critical in human health and disease., (© 2021 The Authors. The FEBS Journal published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.)
- Published
- 2022
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7. Epithelial-myeloid exchange of MHC class II constrains immunity and microbiota composition.
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Stephens WZ, Kubinak JL, Ghazaryan A, Bauer KM, Bell R, Buhrke K, Chiaro TR, Weis AM, Tang WW, Monts JK, Soto R, Ekiz HA, O'Connell RM, and Round JL
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- Animals, Antigens, Bacterial immunology, Antigens, Bacterial metabolism, Bacteria growth & development, Bacteria metabolism, Cell Line, Colitis immunology, Colitis metabolism, Colitis microbiology, Disease Models, Animal, Epithelial Cells metabolism, Epithelial Cells microbiology, Female, Histocompatibility Antigens Class II metabolism, Host-Pathogen Interactions, Ileum immunology, Ileum metabolism, Immunoglobulin A immunology, Immunoglobulin A metabolism, Male, Mice, Inbred C57BL, Mice, Knockout, Mononuclear Phagocyte System metabolism, Mononuclear Phagocyte System microbiology, Myeloid Cells metabolism, Myeloid Cells microbiology, Signal Transduction, T-Lymphocytes, Regulatory immunology, T-Lymphocytes, Regulatory metabolism, Mice, Adaptive Immunity, Bacteria immunology, Epithelial Cells immunology, Gastrointestinal Microbiome, Histocompatibility Antigens Class II immunology, Ileum microbiology, Immunity, Mucosal, Mononuclear Phagocyte System immunology, Myeloid Cells immunology
- Abstract
Intestinal epithelial cells (IECs) have long been understood to express high levels of major histocompatibility complex class II (MHC class II) molecules but are not considered canonical antigen-presenting cells, and the impact of IEC-MHC class II signaling on gut homeostasis remains enigmatic. As IECs serve as the primary barrier between underlying host immune cells, we reasoned that IEC-intrinsic antigen presentation may play a role in responses toward the microbiota. Mice with an IEC-intrinsic deletion of MHC class II (IEC
ΔMHC class II ) are healthy but have fewer microbial-bound IgA, regulatory T cells (Tregs), and immune repertoire selection. This was associated with increased interindividual microbiota variation and altered proportions of two taxa in the ileum where MHC class II on IECs is highest. Intestinal mononuclear phagocytes (MNPs) have similar MHC class II transcription but less surface MHC class II and are capable of acquiring MHC class II from IECs. Thus, epithelial-myeloid interactions mediate development of adaptive responses to microbial antigens within the gastrointestinal tract., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2021
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8. Leveraging E-Learning Infrastructure in Times of Rapid Change: Use of the National Sexually Transmitted Diseases Curriculum in the Era of COVID-19.
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Bauer KM, Corcorran MA, Budak JZ, Johnston C, and Spach DH
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- Curriculum, Humans, Pandemics, SARS-CoV-2, COVID-19, Computer-Assisted Instruction, Sexually Transmitted Diseases epidemiology, Sexually Transmitted Diseases prevention & control
- Abstract
Abstract: The National Sexually Transmitted Diseases Curriculum is an e-learning platform. New registrations and learning group creations in March to April 2020 were compared with previous 12-month data. Substantial increases in registrations and learning groups demonstrate that the National Sexually Transmitted Diseases Curriculum was successfully leveraged to meet rapidly shifting training needs due to the COVID-19 pandemic., Competing Interests: Conflict of Interest and Sources of Funding: None of the authors report conflicts of interest., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Sexually Transmitted Diseases Association.)
- Published
- 2021
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9. A Stat1 bound enhancer promotes Nampt expression and function within tumor associated macrophages.
- Author
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Huffaker TB, Ekiz HA, Barba C, Lee SH, Runtsch MC, Nelson MC, Bauer KM, Tang WW, Mosbruger TL, Cox JE, Round JL, Voth WP, and O'Connell RM
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- Animals, Cytokines metabolism, Disease Models, Animal, Enhancer Elements, Genetic, Female, Gene Expression Regulation, Neoplastic immunology, HEK293 Cells, Humans, Interferon-gamma metabolism, Kaplan-Meier Estimate, Male, Melanoma immunology, Melanoma mortality, Melanoma pathology, Mice, Mice, Knockout, Nicotinamide Phosphoribosyltransferase metabolism, RAW 264.7 Cells, RNA-Seq, Receptors, Interferon genetics, Receptors, Interferon metabolism, Signal Transduction genetics, Signal Transduction immunology, Skin Neoplasms immunology, Skin Neoplasms mortality, Skin Neoplasms pathology, THP-1 Cells, Tumor-Associated Macrophages metabolism, Up-Regulation, Warburg Effect, Oncologic, Interferon gamma Receptor, Cytokines genetics, Melanoma genetics, Nicotinamide Phosphoribosyltransferase genetics, STAT1 Transcription Factor metabolism, Skin Neoplasms genetics, Tumor-Associated Macrophages immunology
- Abstract
Tumor associated macrophage responses are regulated by distinct metabolic states that affect their function. However, the ability of specific signals in the local tumor microenvironment to program macrophage metabolism remains under investigation. Here, we identify NAMPT, the rate limiting enzyme in NAD salvage synthesis, as a target of STAT1 during cellular activation by interferon gamma, an important driver of macrophage polarization and antitumor responses. We demonstrate that STAT1 occupies a conserved element within the first intron of Nampt, termed Nampt-Regulatory Element-1 (NRE1). Through disruption of NRE1 or pharmacological inhibition, a subset of M1 genes is sensitive to NAMPT activity through its impact on glycolytic processes. scRNAseq is used to profile in vivo responses by NRE1-deficient, tumor-associated leukocytes in melanoma tumors through the creation of a unique mouse strain. Reduced Nampt and inflammatory gene expression are present in specific myeloid and APC populations; moreover, targeted ablation of NRE1 in macrophage lineages results in greater tumor burden. Finally, elevated NAMPT expression correlates with IFNγ responses and melanoma patient survival. This study identifies IFN and STAT1-inducible Nampt as an important factor that shapes the metabolic program and function of tumor associated macrophages.
- Published
- 2021
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10. Potential for community based surveillance of febrile diseases: Feasibility of self-administered rapid diagnostic tests in Iquitos, Peru and Phnom Penh, Cambodia.
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Morrison AC, Schwarz J, Mckenney JL, Cordova J, Rios JE, Quiroz WL, Vizcarra SA, Sopheab H, Bauer KM, Chhea C, Saphonn V, Hontz RD, Gorbach PM, and Paz-Soldan VA
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- Adolescent, Adult, Cambodia, Dengue diagnosis, Education methods, Female, Focus Groups, Health Facilities, Health Knowledge, Attitudes, Practice, Health Services Research, Humans, Malaria diagnosis, Male, Melioidosis diagnosis, Middle Aged, Patient Acceptance of Health Care, Peru, Plague diagnosis, Specimen Handling methods, Young Adult, Diagnostic Tests, Routine methods, Diagnostic Tests, Routine standards, Health Personnel education
- Abstract
Rapid diagnostic tests (RDTs) have the potential to identify infectious diseases quickly, minimize disease transmission, and could complement and improve surveillance and control of infectious and vector-borne diseases during outbreaks. The U.S. Defense Threat Reduction Agency's Joint Science and Technology Office (DTRA-JSTO) program set out to develop novel point-of-need RDTs for infectious diseases and deploy them for home use with no training. The aim of this formative study was to address two questions: 1) could community members in Iquitos, Peru and Phnom Penh, Cambodia competently use RDTs of different levels of complexity at home with visually based instructions provided, and 2) if an RDT were provided at no cost, would it be used at home if family members displayed febrile symptoms? Test kits with written and video (Peru only) instructions were provided to community members (Peru [n = 202]; Cambodia [n = 50]) or community health workers (Cambodia [n = 45]), and trained observers evaluated the competency level for each of the several steps required to successfully operate one of two multiplex RDTs on themselves or other consenting participant (i.e., family member). In Iquitos, >80% of residents were able to perform 11/12 steps and 7/15 steps for the two- and five-pathogen test, respectively. Competency in Phnom Penh never reached 80% for any of the 12 or 15 steps for either test; the percentage of participants able to perform a step ranged from 26-76% and 23-72%, for the two- and five-pathogen tests, respectively. Commercially available NS1 dengue rapid tests were distributed, at no cost, to households with confirmed exposure to dengue or Zika virus; of 14 febrile cases reported, six used the provided RDT. Our findings support the need for further implementation research on the appropriate level of instructions or training needed for diverse devices in different settings, as well as how to best integrate RDTs into existing local public health and disease surveillance programs at a large scale., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2021
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11. Mitochondrial Pyruvate Carrier 1 Promotes Peripheral T Cell Homeostasis through Metabolic Regulation of Thymic Development.
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Ramstead AG, Wallace JA, Lee SH, Bauer KM, Tang WW, Ekiz HA, Lane TE, Cluntun AA, Bettini ML, Round JL, Rutter J, and O'Connell RM
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- Animals, Anion Transport Proteins deficiency, Gene Deletion, Glycolysis, Hematopoiesis, Humans, Inflammation pathology, Jurkat Cells, Lymphocyte Count, Mice, Mice, Inbred C57BL, Mitochondrial Membrane Transport Proteins deficiency, Monocarboxylic Acid Transporters deficiency, Oxidation-Reduction, Oxidative Phosphorylation, Pyruvic Acid metabolism, Thymocytes metabolism, Anion Transport Proteins metabolism, Homeostasis, Mitochondrial Membrane Transport Proteins metabolism, Monocarboxylic Acid Transporters metabolism, T-Lymphocytes metabolism, Thymus Gland growth & development, Thymus Gland metabolism
- Abstract
Metabolic pathways regulate T cell development and function, but many remain understudied. Recently, the mitochondrial pyruvate carrier (MPC) was identified as the transporter that mediates pyruvate entry into mitochondria, promoting pyruvate oxidation. Here we find that deleting Mpc1, an obligate MPC subunit, in the hematopoietic system results in a specific reduction in peripheral αβ T cell numbers. MPC1-deficient T cells have defective thymic development at the β-selection, intermediate single positive (ISP)-to-double-positive (DP), and positive selection steps. We find that early thymocytes deficient in MPC1 display alterations to multiple pathways involved in T cell development. This results in preferred escape of more activated T cells. Finally, mice with hematopoietic deletion of Mpc1 are more susceptible to experimental autoimmune encephalomyelitis. Altogether, our study demonstrates that pyruvate oxidation by T cell precursors is necessary for optimal αβ T cell development and that its deficiency results in reduced but activated peripheral T cell populations., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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12. Potential Use of Community-Based Rapid Diagnostic Tests for Febrile Illnesses: Formative Research in Peru and Cambodia.
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Paz-Soldan VA, Morrison AC, Sopheab H, Schwarz J, Bauer KM, Mckenney JL, Chhea C, Saphonn V, Khuon D, Hontz RD, and Gorbach PM
- Subjects
- Adolescent, Adult, Cambodia, Dengue diagnosis, Education methods, Female, Focus Groups, Health Facilities, Health Knowledge, Attitudes, Practice, Health Services Research, Humans, Malaria diagnosis, Male, Melioidosis diagnosis, Middle Aged, Patient Acceptance of Health Care, Peru, Plague diagnosis, Specimen Handling methods, Young Adult, Diagnostic Tests, Routine methods, Diagnostic Tests, Routine standards, Health Personnel education
- Abstract
In 2012, the U.S. Defense Threat Reduction Agency Joint Science and Technology Office initiated a program to develop novel point-of-need diagnostic devices for surveillance of emerging infectious diseases including dengue, malaria, plague, and melioidosis. Prior to distribution of devices to observe their correct use among community members in Iquitos, Peru, and Phnom Penh, Cambodia, research was conducted to: 1) assess acceptability of use, including the motivation to use a rapid diagnostic test (RDT) before or instead of seeking care at a health facility, 2) explore comprehension of RDT use instructions, and 3) examine possible strategies for large scale RDT distribution and use at each site. In February 2014, 9 focus group discussions (FGD) with community members and 5 FGD with health professionals were conducted in Iquitos, and 9 FGD with community members and 9 in-depth interviews with health professionals in Phnom Penh. In both places, participants agreed to use the device themselves (involving finger prick) or could identify someone who could do so in their home or neighborhood. The main incentive to RDT use in both sites was the ability for device results to be used for care facilitation (post confirmatory tests), specifically reduced wait times to be seen or obtain a diagnosis. Comprehension of RDT use instructions was assessed in Iquitos by asking some participants to apply the device to research team members; after watching a short video, most steps were done correctly. In Phnom Penh, participants were asked to describe each step after reading the instructions; they struggled with comprehension. Health professionals' main concerns in both sites were their community's ability to accurately use the test, handle complicated instructions, and safety (i.e., disposal of lancets). Health system structure and ability to use home diagnostic devices varied in the two disease endemic sites, with substantial challenges in each, suggesting the need for different strategies for RDT large scale community use, and illustrating the value of formative research before deployment of novel technologies., Competing Interests: Disclaimer. The views expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, National Institutes of Health, Centers for Disease Control and Prevention, nor the U.S. Government. Disclosure. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. None of the authors has a financial or personal conflict of interest related to this study. Copyright statement: Robert D. Hontz is a military service member. This work was prepared as part of his official duties. Title 17 U.S.C. §105 provides that ‘Copyright protection under this title is not available for any work of the United States Government.’ Title 17 U.S.C. §101 defines a U.S. Government work as a work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties.
- Published
- 2019
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13. The structure of a highly-conserved picocyanobacterial protein reveals a Tudor domain with an RNA-binding function.
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Bauer KM, Dicovitsky R, Pellegrini M, Zhaxybayeva O, and Ragusa MJ
- Subjects
- Bacterial Proteins metabolism, Conserved Sequence, Intrinsically Disordered Proteins metabolism, Prochlorococcus chemistry, Prochlorococcus metabolism, Protein Binding, RNA metabolism, RNA-Binding Proteins metabolism, Synechococcus chemistry, Synechococcus metabolism, Bacterial Proteins chemistry, Intrinsically Disordered Proteins chemistry, RNA-Binding Proteins chemistry, Tudor Domain
- Abstract
Cyanobacteria of the Prochlorococcus and marine Synechococcus genera are the most abundant photosynthetic microbes in the ocean. Intriguingly, the genomes of these bacteria are strongly divergent even within each genus, both in gene content and at the amino acid level of the encoded proteins. One striking exception to this is a 62-amino-acid protein, termed P rochlorococcus / S ynechococcush yper- c onserved p rotein (PSHCP). PSHCP is not only found in all sequenced Prochlorococcus and marine Synechococcus genomes, but it is also nearly 100% identical in its amino acid sequence across all sampled genomes. Such universal distribution and sequence conservation suggest an essential cellular role of PSHCP in these bacteria. However, its function is unknown. Here, we used NMR spectroscopy to determine its structure, finding that 53 of the 62 amino acids in PSHCP form a Tudor domain, whereas the remainder of the protein is disordered. NMR titration experiments revealed that PSHCP has only a weak affinity for DNA, but an 18.5-fold higher affinity for tRNA, hinting at an involvement of PSHCP in translation. Isothermal titration calorimetry experiments further revealed that PSHCP also binds single-stranded, double-stranded, and hairpin RNAs. These results provide the first insight into the structure and function of PSHCP, suggesting that PSHCP appears to be an RNA-binding protein that can recognize a broad array of RNA molecules., (© 2019 Bauer et al.)
- Published
- 2019
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14. Induced Chromosomal Aneuploidy Results in Global and Consistent Deregulation of the Transcriptome of Cancer Cells.
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Wangsa D, Braun R, Stuelten CH, Brown M, Bauer KM, Emons G, Weston LA, Hu Y, Yang HH, Vila-Casadesús M, Lee MP, Brauer P, Warner L, Upender M, Hummon AB, Camps J, and Ried T
- Subjects
- Aneuploidy, Colorectal Neoplasms pathology, Comparative Genomic Hybridization, DNA Copy Number Variations genetics, Gene Expression Regulation, Neoplastic, Humans, Neoplasm Proteins genetics, Transcriptional Activation genetics, Chromosomes genetics, Colorectal Neoplasms genetics, Monomeric GTP-Binding Proteins genetics, Transcriptome genetics
- Abstract
Chromosomal aneuploidy is a defining feature of epithelial cancers. The pattern of aneuploidies is cancer-type specific. For instance, the gain of chromosome 13 occurs almost exclusively in colorectal cancer. We used microcell-mediated chromosome transfer to generate gains of chromosome 13 in the diploid human colorectal cancer cell line DLD-1. Extra copies of chromosome 13 resulted in a significant and reproducible up-regulation of transcript levels of genes on chromosome 13 (P = .0004, FDR = 0.01) and a genome-wide transcriptional deregulation in all 8 independent clones generated. Genes contained in two clusters were particularly affected: the first cluster on cytoband 13q13 contained 7 highly up-regulated genes (NBEA, MAB21L1, DCLK1, SOHLH2, CCDC169, SPG20 and CCNA1, P = .0003) in all clones. A second cluster was located on 13q32.1 and contained five upregulated genes (ABCC4, CLDN10, DZIP1, DNAJC3 and UGGT2, P = .003). One gene, RASL11A, localized on chromosome band 13q12.2, escaped the copy number-induced overexpression and was reproducibly and significantly down-regulated on the mRNA and protein level (P = .0001, FDR = 0.002). RASL11A expression levels were also lower in primary colorectal tumors as compared to matched normal mucosa (P = .0001, FDR = 0.0001. Overexpression of RASL11A increases cell proliferation and anchorage independent growth while decreasing cell migration in +13 clones. In summary, we observed a strict correlation of genomic copy number and resident gene expression levels, and aneuploidy dependent consistent genome-wide transcriptional deregulation., (Copyright © 2019. Published by Elsevier Inc.)
- Published
- 2019
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15. Anti-inflammatory microRNA-146a protects mice from diet-induced metabolic disease.
- Author
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Runtsch MC, Nelson MC, Lee SH, Voth W, Alexander M, Hu R, Wallace J, Petersen C, Panic V, Villanueva CJ, Evason KJ, Bauer KM, Mosbruger T, Boudina S, Bronner M, Round JL, Drummond MJ, and O'Connell RM
- Subjects
- Animals, Blood Glucose metabolism, Diet, High-Fat adverse effects, Disease Models, Animal, Female, Gene Expression, Humans, Hyperglycemia genetics, Hyperglycemia metabolism, Hyperglycemia prevention & control, Inflammation genetics, Inflammation metabolism, Insulin blood, Intra-Abdominal Fat metabolism, Intra-Abdominal Fat pathology, Macrophages metabolism, Male, Metabolic Diseases genetics, Metabolic Diseases metabolism, Mice, Mice, Inbred C57BL, Mice, Knockout, MicroRNAs antagonists & inhibitors, NF-kappa B metabolism, Obesity genetics, Obesity metabolism, Obesity prevention & control, Proto-Oncogene Proteins c-akt genetics, Sirolimus pharmacology, TOR Serine-Threonine Kinases antagonists & inhibitors, TOR Serine-Threonine Kinases genetics, Weight Gain drug effects, Weight Gain genetics, Inflammation prevention & control, Metabolic Diseases prevention & control, MicroRNAs genetics, MicroRNAs metabolism
- Abstract
Identifying regulatory mechanisms that influence inflammation in metabolic tissues is critical for developing novel metabolic disease treatments. Here, we investigated the role of microRNA-146a (miR-146a) during diet-induced obesity in mice. miR-146a is reduced in obese and type 2 diabetic patients and our results reveal that miR-146a-/- mice fed a high-fat diet (HFD) have exaggerated weight gain, increased adiposity, hepatosteatosis, and dysregulated blood glucose levels compared to wild-type controls. Pro-inflammatory genes and NF-κB activation increase in miR-146a-/- mice, indicating a role for this miRNA in regulating inflammatory pathways. RNA-sequencing of adipose tissue macrophages demonstrated a role for miR-146a in regulating both inflammation and cellular metabolism, including the mTOR pathway, during obesity. Further, we demonstrate that miR-146a regulates inflammation, cellular respiration and glycolysis in macrophages through a mechanism involving its direct target Traf6. Finally, we found that administration of rapamycin, an inhibitor of mTOR, was able to rescue the obesity phenotype in miR-146a-/- mice. Altogether, our study provides evidence that miR-146a represses inflammation and diet-induced obesity and regulates metabolic processes at the cellular and organismal levels, demonstrating how the combination of diet and miRNA genetics influences obesity and diabetic phenotypes., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2019
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16. Functional dissection of the ARGONAUTE7 promoter.
- Author
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Hoyer JS, Pruneda-Paz JL, Breton G, Hassert MA, Holcomb EE, Fowler H, Bauer KM, Mreen J, Kay SA, and Carrington JC
- Abstract
ARGONAUTES are the central effector proteins of RNA silencing which bind target transcripts in a small RNA-guided manner. Arabidopsis thaliana has 10 ARGONAUTE ( AGO ) genes, with specialized roles in RNA-directed DNA methylation, post-transcriptional gene silencing, and antiviral defense. To better understand specialization among AGO genes at the level of transcriptional regulation we tested a library of 1497 transcription factors for binding to the promoters of AGO1 , AGO10 , and AGO7 using yeast 1-hybrid assays. A ranked list of candidate DNA-binding TFs revealed binding of the AGO7 promoter by a number of proteins in two families: the miR156-regulated SPL family and the miR319-regulated TCP family, both of which have roles in developmental timing and leaf morphology. Possible functions for SPL and TCP binding are unclear: we showed that these binding sites are not required for the polar expression pattern of AGO7 , nor for the function of AGO7 in leaf shape. Normal AGO7 transcription levels and function appear to depend instead on an adjacent 124-bp region. Progress in understanding the structure of this promoter may aid efforts to understand how the conserved AGO7-triggered TAS3 pathway functions in timing and polarity.
- Published
- 2019
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17. Cell-mediated immune responses to different formulations of a live-attenuated tetravalent dengue vaccine candidate in subjects living in dengue endemic and non-endemic regions.
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Moris P, Bauer KM, Currier JR, Friberg H, Eckels KH, Esquilin IO, Gibbons RV, Innis BL, Jarman RG, Simasathien S, Sun P, Thomas SJ, and Watanaveeradej V
- Subjects
- Adolescent, Adult, Antibodies, Viral blood, Child, Child, Preschool, Cohort Studies, Dengue Virus, Endemic Diseases, Female, Humans, Immunologic Memory, Infant, Male, Middle Aged, Puerto Rico, Thailand, Vaccines, Attenuated immunology, Young Adult, Dengue prevention & control, Dengue Vaccines immunology, Immunity, Cellular
- Abstract
Three phase II randomized trials evaluated the safety/immunogenicity of two formulations of live-attenuated tetravalent dengue virus (TDEN) vaccine in dengue-endemic (Puerto Rico, Thailand) and non-endemic (US) regions (NCT00350337/NCT00370682/NCT00468858). We describe cell-mediated immune (CMI) responses; safety and humoral responses were reported previously. Participants received two doses of vaccine or control (placebo or the precursor live-attenuated TDEN vaccine) 6 months apart. Selected US participants received a booster 5-12 months post-dose 2. Evaluated subsets of the per-protocol cohorts included 75 primarily dengue virus (DENV)-unprimed US adults, 69 primarily flavivirus-primed Thai adults, and 100 DENV-primed or DENV-unprimed Puerto Rican adults/adolescents/children. T-cell responses were quantified using intracellular cytokine staining (ICS; DENV-infected cell-lysate or DENV-1/DENV-2 peptide-pool stimulation) or IFN-γ ELISPOT (DENV-2 peptide-pool stimulation). Memory B-cell responses were quantified using B-cell ELISPOT. Across populations and age strata, DENV serotype-specific CD4
+ T-cell responses were slightly to moderately increased (medians ≤0.18% [ICS]), DENV-2-biased, and variable for both formulations. Responses in unprimed subjects were primarily detected post-dose 1. Response magnitudes in primed subjects were similar between doses. Multifunctional CD8+ T-cell responses were detected after peptide-pool stimulation. T-cell responses were mostly directed to DENV nonstructural proteins 3 and 5. Memory B-cell responses were tetravalent, of low-to-moderate magnitudes (medians ≤0.25%), and mainly observed post-dose 2 in unprimed subjects and post-dose 1 in primed subjects. A third dose did not boost CMI responses. In conclusion, both formulations of the live-attenuated TDEN vaccine candidate were poorly to moderately immunogenic with respect to B-cell and T-cell responses, irrespective of the priming status of the participants. Abbreviation ATP: according-to-protocol; ICS: Intracellular Cytokine Staining; NS3: Nonstructural protein 3; ELISPOT: Enzyme-Linked ImmunoSpot; JEV: Japanese encephalitis virus; PBMC: peripheral blood mononuclear cells.- Published
- 2019
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18. Calcitriol Supplementation Causes Decreases in Tumorigenic Proteins and Different Proteomic and Metabolomic Signatures in Right versus Left-Sided Colon Cancer.
- Author
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Schroll MM, Ludwig KR, Bauer KM, and Hummon AB
- Abstract
Vitamin D deficiency is a common problem worldwide. In particular, it is an issue in the Northern Hemisphere where UVB radiation does not penetrate the atmosphere as readily. There is a correlation between vitamin D deficiency and colorectal cancer incidence and mortality. Furthermore, there is strong evidence that cancer of the ascending (right side) colon is different from cancer of the descending (left side) colon in terms of prognosis, tumor differentiation, and polyp type, as well as at the molecular level. Right-side tumors have elevated Wnt signaling and are more likely to relapse, whereas left-side tumors have reduced expression of tumor suppressor genes. This study seeks to understand both the proteomic and metabolomic changes resulting from treatment of the active metabolite of vitamin D, calcitriol, in right-sided and left-sided colon cancer. Our results show that left-sided colon cancer treated with calcitriol has a substantially greater number of changes in both the proteome and the metabolome than right-sided colon cancer. We found that calcitriol treatment in both right-sided and left-sided colon cancer causes a downregulation of ribosomal protein L37 and protein S100A10. Both of these proteins are heavily involved in tumorigenesis, suggesting a possible mechanism for the correlation between low vitamin D levels and colon cancer., Competing Interests: The authors declare no conflict of interest.
- Published
- 2018
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19. A pseudo-receiver domain in Atg32 is required for mitophagy.
- Author
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Xia X, Katzenell S, Reinhart EF, Bauer KM, Pellegrini M, and Ragusa MJ
- Subjects
- Amino Acid Sequence, Nitrogen deficiency, Protein Domains, Structure-Activity Relationship, Autophagy-Related Proteins chemistry, Autophagy-Related Proteins metabolism, Mitophagy, Receptors, Cytoplasmic and Nuclear chemistry, Receptors, Cytoplasmic and Nuclear metabolism, Saccharomyces cerevisiae metabolism, Saccharomyces cerevisiae Proteins chemistry, Saccharomyces cerevisiae Proteins metabolism
- Abstract
Mitochondria are targeted for degradation by mitophagy, a selective form of autophagy. In Saccharomyces cerevisiae, mitophagy is dependent on the autophagy receptor, Atg32, an outer mitochondrial membrane protein. Once activated, Atg32 recruits the autophagy machinery to mitochondria, facilitating mitochondrial capture in phagophores, the precursors to autophagosomes. However, the mechanism of Atg32 activation remains poorly understood. To investigate this crucial step in mitophagy regulation, we examined the structure of Atg32. We have identified a structured domain in Atg32 that is essential for the initiation of mitophagy, as it is required for the proteolysis of the C-terminal domain of Atg32 and the subsequent recruitment of Atg11. The solution structure of this domain was determined by NMR spectroscopy, revealing that Atg32 contains a previously undescribed pseudo-receiver (PsR) domain. Our data suggests that the PsR domain of Atg32 regulates Atg32 activation and the initiation of mitophagy., Abbreviations: AIM: Atg8-interacting motif; GFP: green fluorescent protein; LIR: LC3-interacting region; NMR: nuclear magnetic resonance; NOESY: nuclear Overhauser effect spectroscopy; PDB: protein data bank; PsR: pseudo-receiver; RMSD: root-mean-square deviation.
- Published
- 2018
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20. Drosophila melanogaster retrotransposon and inverted repeat-derived endogenous siRNAs are differentially processed in distinct cellular locations.
- Author
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Harrington AW, McKain MR, Michalski D, Bauer KM, Daugherty JM, and Steiniger M
- Subjects
- 3' Untranslated Regions, Animals, Drosophila Proteins antagonists & inhibitors, Drosophila Proteins genetics, Drosophila Proteins metabolism, Drosophila melanogaster genetics, High-Throughput Nucleotide Sequencing, Microscopy, Fluorescence, RNA Interference, RNA, Messenger chemistry, RNA, Messenger genetics, RNA, Messenger metabolism, RNA, Small Interfering genetics, Sequence Analysis, RNA, mRNA Cleavage and Polyadenylation Factors genetics, mRNA Cleavage and Polyadenylation Factors metabolism, RNA, Small Interfering metabolism, Retroelements genetics
- Abstract
Background: Endogenous small interfering (esi)RNAs repress mRNA levels and retrotransposon mobility in Drosophila somatic cells by poorly understood mechanisms. 21 nucleotide esiRNAs are primarily generated from retrotransposons and two inverted repeat (hairpin) loci in Drosophila culture cells in a Dicer2 dependent manner. Additionally, proteins involved in 3' end processing, such as Symplekin, CPSF73 and CPSR100, have been recently implicated in the esiRNA pathway., Results: Here we present evidence of overlap between two essential RNA metabolic pathways: esiRNA biogenesis and mRNA 3' end processing. We have identified a nucleus-specific interaction between the essential esiRNA cleavage enzyme Dicer2 (Dcr2) and Symplekin, a component of the core cleavage complex (CCC) required for 3' end processing of all eukaryotic mRNAs. This interaction is mediated by the N-terminal 271 amino acids of Symplekin; CCC factors CPSF73 and CPSF100 do not contact Dcr2. While Dcr2 binds the CCC, Dcr2 knockdown does not affect mRNA 3' end formation. RNAi-depletion of CCC components Symplekin and CPSF73 causes perturbations in esiRNA abundance that correlate with fluctuations in retrotransposon and hairpin esiRNA precursor levels. We also discovered that esiRNAs generated from retrotransposons and hairpins have distinct physical characteristics including a higher predominance of 22 nucleotide hairpin-derived esiRNAs and differences in 3' and 5' base preference. Additionally, retrotransposon precursors and derived esiRNAs are highly enriched in the nucleus while hairpins and hairpin derived esiRNAs are predominantly cytoplasmic similar to canonical mRNAs. RNAi-depletion of either CPSF73 or Symplekin results in nuclear retention of both hairpin and retrotransposon precursors suggesting that polyadenylation indirectly affects cellular localization of Dcr2 substrates., Conclusions: Together, these observations support a novel mechanism in which differences in localization of esiRNA precursors impacts esiRNA biogenesis. Hairpin-derived esiRNAs are generated in the cytoplasm independent of Dcr2-Symplekin interactions, while retrotransposons are processed in the nucleus.
- Published
- 2017
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21. Experiences with insecticide-treated curtains: a qualitative study in Iquitos, Peru.
- Author
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Paz-Soldan VA, Bauer KM, Lenhart A, Cordova Lopez JJ, Elder JP, Scott TW, McCall PJ, Kochel TJ, and Morrison AC
- Subjects
- Adult, Aged, Aged, 80 and over, Animals, Arthropod Vectors, Female, Focus Groups, Health Knowledge, Attitudes, Practice, Humans, Male, Middle Aged, Peru, Qualitative Research, Surveys and Questionnaires, Aedes drug effects, Dengue prevention & control, Insecticide-Treated Bednets statistics & numerical data, Mosquito Control methods
- Abstract
Background: Dengue is an arthropod-borne viral disease responsible for approximately 400 million infections annually; the only available method of prevention is vector control. It has been previously demonstrated that insecticide treated curtains (ITCs) can lower dengue vector infestations in and around houses. As part of a larger trial examining whether ITCs could reduce dengue transmission in Iquitos, Peru, the objective of this study was to characterize the participants' experience with the ITCs using qualitative methods., Methods: Knowledge, attitudes, and practices (KAP) surveys (at baseline, and 9 and 27 months post-ITC distribution, with n = 593, 595 and 511, respectively), focus group discussions (at 6 and 12 months post-ITC distribution, with n = 18 and 33, respectively), and 11 one-on-one interviews (at 12 months post-distribution) were conducted with 605 participants who received ITCs as part of a cluster-randomized trial., Results: Focus groups at 6 months post-ITC distribution revealed that individuals had observed their ITCs to function for approximately 3 months, after which they reported the ITCs were no longer working. Follow up revealed that the ITCs required re-treatment with insecticide at approximately 1 year post-distribution. Over half (55.3 %, n = 329) of participants at 9 months post-ITC distribution and over a third (34.8 %, n = 177) at 27 months post-ITC distribution reported perceiving a decrease in the number of mosquitoes in their home. The percentage of participants who would recommend ITCs to their family or friends in the future remained high throughout the study (94.3 %, n = 561 at 9 months and 94.6 %, n = 488 at 27 months post-distribution). When asked why, participants reported that ITCs were effective at reducing mosquitoes (81.6 and 37.8 %, at 9 and 27 months respectively), that they prevent dengue (5.7 and 51.2 %, at 9 and 27 months), that they are "beautiful" (5.9 and 3.1 %), as well as other reasons (6.9 and 2.5 %)., Conclusion: ITCs have substantial potential for long term dengue vector control because they are liked by users, both for their perceived effectiveness and for aesthetic reasons, and because they require little proactive behavioral effort on the part of the users. Our results highlight the importance of gathering process (as opposed to outcome) data during vector control studies, without which researchers would not have become aware that the ITCs had lost effectiveness early in the trial.
- Published
- 2016
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22. Safety and Immunogenicity of a Dengue Virus Serotype-1 Purified-Inactivated Vaccine: Results of a Phase 1 Clinical Trial.
- Author
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Martinez LJ, Lin L, Blaylock JM, Lyons AG, Bauer KM, De La Barrera R, Simmons M, Jarman RG, Currier JR, Friberg H, Danko JR, Teneza-Mora NC, Putnak JR, Eckels KH, and Thomas SJ
- Subjects
- Adolescent, Adult, Antibodies, Neutralizing immunology, Antibodies, Viral immunology, Dengue Vaccines administration & dosage, Dengue Vaccines adverse effects, Dengue Vaccines immunology, Dengue Virus immunology, Enzyme-Linked Immunosorbent Assay, Female, Humans, Immunoglobulin G immunology, Immunoglobulin M immunology, Male, Middle Aged, Vaccines, Inactivated adverse effects, Vaccines, Inactivated immunology, Vaccines, Inactivated therapeutic use, Young Adult, Dengue Vaccines therapeutic use
- Abstract
We describe the results from a human clinical trial of a dengue virus serotype-1, purified-inactivated vaccine (DENV-1 PIV) adjuvanted with aluminum hydroxide. This first-in-man, Phase 1, open-label clinical trial consisted of two groups of flavivirus-naïve healthy adult volunteers that received two intramuscular vaccine doses of either 2.5 μg or 5 μg of DENV-1 PIV administered on days 0 and 28. Following vaccination, both vaccine doses exhibited an acceptable safety profile with minimal injection site and systemic reactions. By study day 42, 2 weeks following the second vaccine dose, all volunteers in both vaccine groups developed serum-neutralizing antibodies against DENV-1. Additional testing using an enzyme-linked immunosorbent assay demonstrated induction of a humoral immune response following both vaccine doses. The DENV-1 PIV was safe and immunogenic in a small number of volunteers supporting development and further testing of a tetravalent DENV PIV formulation., (© The American Society of Tropical Medicine and Hygiene.)
- Published
- 2015
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23. Evaluation of left-turn lane offset using the naturalistic driving study data.
- Author
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Hutton JM, Bauer KM, Fees CA, and Smiley A
- Subjects
- Humans, Logistic Models, Motor Vehicles, Problem Solving, Accidents, Traffic prevention & control, Automobile Driving, Environment Design, Safety
- Abstract
Introduction: The Strategic Highway Research Program 2 (SHRP 2) Naturalistic Driving Study (NDS) data were used to evaluate gap acceptance behavior of drivers at left-turn lanes with negative, zero, or positive offsets ranging from -29 ft to +6 ft. The objectives of the study were to develop guidance for the design of offset left-turn lanes used as a safety countermeasure, and to provide insight regarding the use of the NDS data to future users., Method: The study included 3350 gaps in opposing traffic evaluated by 145 NDS volunteer drivers and 275 non-NDS drivers at 14 two-way stop-controlled intersections and 44 signalized opposing left-turn pairs. Logistic regression was used to model the critical gap length for drivers as a function of offset, under conditions when their view was either blocked or not by an opposing left-turning driver., Results: The analysis found that the critical gap was longer at left-turn lanes with negative offsets than at those with zero or positive offsets, and was also longer when sight distance was blocked by an opposing left-turning vehicle. Sight distance was much more likely to be restricted by an opposing left-turning vehicle at negative-offset and drivers at those intersections were less likely to accept a gap when an opposing left-turn driver was present., Conclusions: Longer gap lengths could potentially result in decreased operational efficiency of an intersection. In addition, drivers making left-turns at negative-offset left-turn lanes are, on average, more likely to leave the shortest amount of time between their turn and the arrival of the next opposing through-vehicle, which may present a potential safety concern., Practical Applications: The findings provide guidance for highway designers considering using offset left-turn lanes as a crash countermeasure. This research also highlights the benefits and limitations of using the SHRP 2 NDS data to answer similar research questions., (Copyright © 2015 Elsevier Ltd and National Safety Council. All rights reserved.)
- Published
- 2015
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24. Experimental determination of cascade parameters of a hearing-aid microphone via the two-load method.
- Author
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Egolf DP, Haley BT, Bauer KM, Howell HC, and Larson VD
- Subjects
- Electronics, Mathematics, Hearing Aids, Models, Theoretical
- Abstract
Presented in this article is a computer-aided experimental method for obtaining the cascade parameters of the two-port model of a miniature hearing-aid microphone. The method is an adaptation of the "two-load" method [D.P. Egolf and R.G. Leonard, J. Acoust. Soc. Am. 62, 1013-1023 (1977)] to acoustoelectric, rather than electroacoustic, transducers. The cascade parameters of a particular microphone, determined by this method, were within 2.5 dB of the manufacturer's published open-circuit sensitivity data. In an attempt to further verify the numerical cascade-parameter data, a two-port model of the microphone was used to simulate experimental voltages developed across two different complex electrical load impedances attached to the microphone. The results showed experimental/simulation differences of no greater than 3.0 dB at any frequency. The two-port microphone model and associated cascade parameters are currently being incorporated into a computer-based plan for mathematical simulation of an entire in situ hearing aid.
- Published
- 1988
- Full Text
- View/download PDF
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