Medicine and Health Sciences Commons^™

Cystic Fibrosis Lung Infections: Polymicrobial, Complex, And Hard To Treat, Laura M. Filkins, George A. O’Toole

Dartmouth Scholarship

No abstract provided.

Framework For Hyperspectral Image Processing And Quantification For Cancer Detection During Animal Tumor Surgery, Guolan Lu, Dongsheng Wang, Xulei Qin, Luma Halig, Susan Muller, Hongzheng Zhang, Amy Chen, Brian W. Pogue, Zhuo G. Chen

Dartmouth Scholarship

Hyperspectral imaging (HSI) is an imaging modality that holds strong potential for rapid cancer detection during image-guided surgery. But the data from HSI often needs to be processed appropriately in order to extract the maximum useful information that differentiates cancer from normal tissue. We proposed a framework for hyperspectral image processing and quantification, which includes a set of steps including image preprocessing, glare removal, feature extraction, and ultimately image classification. The framework has been tested on images from mice with head and neck cancer, using spectra from 450- to 900-nm wavelength. The image analysis computed Fourier coefficients, normalized reflectance, mean, …

Functional Dyadicity And Heterophilicity Of Gene-Gene Interactions In Statistical Epistasis Networks, Ting Hu, Angeline S. Andrew, Margaret R. Karagas, Jason H. Moore

Dartmouth Scholarship

Background: The interaction effect among multiple genetic factors, i.e. epistasis, plays an important role in explaining susceptibility on common human diseases and phenotypic traits. The uncertainty over the number of genetic attributes involved in interactions poses great challenges in genetic association studies and calls for advanced bioinformatics methodologies. Network science has gained popularity in modeling genetic interactions thanks to its structural characterization of large numbers of entities and their complex relationships. However, little has been done on functionally interpreting statistically inferred epistatic interactions using networks. Results: In this study, we propose to characterize gene functional properties in the context of …

The Happy Older Latinos Are Active (Hola) Health Promotion And Prevention Study: Study Protocol For A Pilot Randomized Controlled Trial, Daniel E. Jimenez, Charles F. Reynolds, Margarita Alegría, Philip Harvey, Stephen Bartels

Dartmouth Scholarship

Results of previous studies attest to the greater illness burden of common mental disorders (anxiety and depression) in older Latinos and the need for developing preventive interventions that are effective, acceptable, and scalable. Happy Older Latinos are Active (HOLA) is a newly developed intervention that uses a community health worker (CHW) to lead a health promotion program in order to prevent common mental disorders among at-risk older Latinos. This pilot study tests the feasibility and acceptability of delivering HOLA to older, at-risk Latinos.

Methods/Design: HOLA is a multi-component, health promotion intervention funded by the National Institute of Mental Health (NIMH). …

Iron-Dependent Gene Expression In Actinomyces Oris, Matthew P. Mulé, David Giacalone, Kayla Lawlor, Alexa Golden, Caroline Cook, Thomas Lott, Elizabeth Aksten, George A. O'Toole, Lori J. Bergeron

Dartmouth Scholarship

Actinomyces oris is a Gram-positive bacterium that has been associated with healthy and diseased sites in the human oral cavity. Most pathogenic bacteria require iron to survive, and in order to acquire iron in the relatively iron-scarce oral cavity A. oris has been shown to produce iron-binding molecules known as siderophores. The genes encoding these siderophores and transporters are thought to be regulated by the amount of iron in the growth medium and by the metal-dependent repressor, AmdR, which we showed previously binds to the promoter of proposed iron-regulated genes.

Leveraging Global Gene Expression Patterns To Predict Expression Of Unmeasured Genes, James Rudd, René A. Zelaya, Eugene Demidenko, Ellen L. Goode, Casey S. Greene S. Greene, Jennifer A. Doherty

Dartmouth Scholarship

BackgroundLarge collections of paraffin-embedded tissue represent a rich resource to test hypotheses based on gene expression patterns; however, measurement of genome-wide expression is cost-prohibitive on a large scale. Using the known expression correlation structure within a given disease type (in this case, high grade serous ovarian cancer; HGSC), we sought to identify reduced sets of directly measured (DM) genes which could accurately predict the expression of a maximized number of unmeasured genes.

Nucleus Accumbens Deep Brain Stimulation In A Rat Model Of Binge Eating, W. T. Doucette, J. Y. Khokhar, A. I. Green

Dartmouth Scholarship

Binge eating (BE) is a difficult-to-treat behavior with high relapse rates, thus complicating several disorders including obesity. In this study, we tested the effects of high-frequency deep brain stimulation (DBS) in a rodent model of BE. We hypothesized that BE rats receiving high-frequency DBS in the nucleus accumbens (NAc) core would have reduced binge sizes compared with sham stimulation in both a 'chronic BE' model as well as in a 'relapse to chronic BE' model. Male Sprague-Dawley rats (N=18) were implanted with stimulating electrodes in bilateral NAc core, and they received either active stimulation (N=12) or sham stimulation (N=6) for …

Characterization Of The Paracoccidioides Hypoxia Response Reveals New Insights Into Pathogenesis Mechanisms Of This Important Human Pathogenic Fungus, Patrícia De Sousa Lima, Dawoon Chung, Alexandre Melo Bailão, Robert A. Cramer, Célia Maria De Almeida Soares

Dartmouth Scholarship

Background: Hypoxic microenvironments are generated during fungal infection. It has been described that to survive in the human host, fungi must also tolerate and overcome in vivo microenvironmental stress conditions including low oxygen tension; however nothing is known how Paracoccidioides species respond to hypoxia. The genus Paracoccidioides comprises human thermal dimorphic fungi and are causative agents of paracoccidioidomycosis (PCM), an important mycosis in Latin America.

‘Much Clearer With Pictures’: Using Community-Based Participatory Research To Design And Test A Picture Option Grid For Underserved Patients With Breast Cancer, Marie-Anne Durand, Shama Alam, Stuart W. Grande, Glyn Elwyn

Dartmouth Scholarship

Women of low socioeconomic status (SES) diagnosed with early stage breast cancer experience decision-making, treatment and outcome disparities. Evidence suggests that decision aids can benefit underserved patients, when tailored to their needs. Our aim was to develop and test the usability, acceptability and accessibility of a pictorial encounter decision aid targeted at women of low SES diagnosed with early stage breast cancer.

Improved Sensitivity To Fluorescence For Cancer Detection In Wide-Field Image-Guided Neurosurgery, Michael Jermyn, Yoann Gosselin, Pablo A. Valdes, Mira Sibai, Kolbein Kolste

Dartmouth Scholarship

In glioma surgery, Protoporphyrin IX (PpIX) fluorescence may identify residual tumor that could be resected while minimizing damage to normal brain. We demonstrate that improved sensitivity for wide-field spectroscopic fluorescence imaging is achieved with minimal disruption to the neurosurgical workflow using an electron-multiplying charge-coupled device (EMCCD) relative to a state-of-the-art CMOS system. In phantom experiments the EMCCD system can detect at least two orders-of-magnitude lower PpIX. Ex vivo tissue imaging on a rat glioma model demonstrates improved fluorescence contrast compared with neurosurgical fluorescence microscope technology, and the fluorescence detection is confirmed with measurements from a clinically-validated spectroscopic probe. Greater PpIX …

Cyclin-Dependent Kinase Inhibitor P1446a Induces Apoptosis In A Jnk/P38 Mapk-Dependent Manner In Chronic Lymphocytic Leukemia B-Cells, Cody Paiva, J. Claire Godbersen, Ryan S. Soderquist, Taylor Rowland, Sumner Kilmarx

Dartmouth Scholarship

CDK (cyclin-dependent kinase) inhibitors have shown remarkable activity in CLL, where its efficacy has been linked to inhibition of the transcriptional CDKs (7 and 9) and deregulation of RNA polymerase and short-lived pro-survival proteins such as MCL1. Furthermore, ER (endoplasmic reticulum) stress has been implicated in CDK inhibition in CLL. Here we conducted a pre-clinical study of a novel orally active kinase inhibitor P1446A in CLL B-cells. P1446A inhibited CDKs at nanomolar concentrations and induced rapid apoptosis of CLL cells in vitro, irrespective of chromosomal abnormalities or IGHV mutational status. Apoptosis preceded inactivation of RNA polymerase, and was accompanied by …

Systematic Analysis Of Hematopoietic Gene Expression Profiles For Prognostic Prediction In Acute Myeloid Leukemia, Frederick S. Varn, Erik H. Andrews, Chao Cheng

Dartmouth Scholarship

Acute myeloid leukemia (AML) is a hematopoietic disorder initiated by the leukemogenic transformation of myeloid cells into leukemia stem cells (LSCs). Preexisting gene expression programs in LSCs can be used to assess their transcriptional similarity to hematopoietic cell types. While this relationship has previously been examined on a small scale, an analysis that systematically investigates this relationship throughout the hematopoietic hierarchy has yet to be implemented. We developed an integrative approach to assess the similarity between AML patient tumor profiles and a collection of 232 murine hematopoietic gene expression profiles compiled by the Immunological Genome Project. The resulting lineage similarity …

Yeast Vacuolar Hops, Regulated By Its Kinase, Exploits Affinities For Acidic Lipids And Rab:Gtp For Membrane Binding And To Catalyze Tethering And Fusion, Amy Orr, William Wickner, Scott F. Rusin, Arminja N. Kettenbach, Michael Zick

Dartmouth Scholarship

Fusion of yeast vacuoles requires the Rab GTPase Ypt7p, four SNAREs (soluble N-ethylmaleimide–sensitive factor attachment protein receptors), the SNARE disassembly chaperones Sec17p/Sec18p, vacuolar lipids, and the Rab-effector complex HOPS (homotypic fusion and vacuole protein sorting). Two HOPS subunits have direct affinity for Ypt7p. Although vacuolar fusion has been reconstituted with purified components, the functional relationships between individual lipids and Ypt7p:GTP have remained unclear. We now report that acidic lipids function with Ypt7p as coreceptors for HOPS, supporting membrane tethering and fusion. After phosphorylation by the vacuolar kinase Yck3p, phospho-HOPS needs both Ypt7p:GTP and acidic lipids to support fusion.

Calibration And Optimization Of 3d Digital Breast Tomosynthesis Guided Near Infrared Spectral Tomography, Kelly E. Michaelsen, Venkataramanan Krishnaswamy, Linxi Shi, Srinivasan Vedantham, Steven Poplack, Andrew Karellas, Brian Pogue, Keith Paulsen

Dartmouth Scholarship

Calibration of a three-dimensional multimodal digital breast tomosynthesis (DBT) x-ray and non-fiber based near infrared spectral tomography (NIRST) system is challenging but essential for clinical studies. Phantom imaging results yielded linear contrast recovery of total hemoglobin (HbT) concentration for cylindrical inclusions of 15 mm, 10 mm and 7 mm with a 3.5% decrease in the HbT estimate for each 1 cm increase in inclusion depth. A clinical exam of a patient's breast containing both benign and malignant lesions was successfully imaged, with greater HbT was found in the malignancy relative to the benign abnormality and fibroglandular regions (11 μM vs. …

Current Practice Of Neonatal Resuscitation Documentation In North America: A Multi-Center Retrospective Chart Review, Matthew S. Braga, Prakash Kabbur, Pradeep Alur, Michael H. Goodstein

Dartmouth Scholarship

To determine the comprehensiveness of neonatal resuscitation documentation and to determine the association of various patient, provider and institutional factors with completeness of neonatal documentation. Multi-center retrospective chart review of a sequential sample of very low birth weight infants born in 2013. The description of resuscitation in each infant’s record was evaluated for the presence of 29 Resuscitation Data Items and assigned a Number of items documented per record. Covariates associated with this Assessment were identified.

Microrna Molecular Profiling From Matched Tumor And Bio-Fluids In Bladder Cancer, David A. Armstrong, Benjamin B. Green, John D. Seigne, Alan R. Schned, Carmen Marsit

Dartmouth Scholarship

MicroRNAs have been identified as potential cancer biomarkers due to their presence and stability in many body fluids including urine and plasma, but the relationship of the pattern of expression of these messengers across various biological media has not been addressed and could provide important information in order to translate these biomarkers for epidemiologic or clinical use. We analyzed microRNA of matched FFPE-tumor tissue, plasma, urine exosomes (n = 16) and WBCs (n = 11) from patients with bladder cancer, using Nanostring miRNA assays and droplet digital PCR for validation. Pearson correlations were used to compare expression between …

Mice Null For The Deubiquitinase Usp18 Spontaneously Develop Leiomyosarcomas, Fadzai Chinyengetere, David J. Sekula, Yun Lu, Andrew J. Giustini, Aarti Sanglikar, Masanori Kawakami, Tian Ma

Dartmouth Scholarship

USP18 (ubiquitin-specific protease 18) removes ubiquitin-like modifier interferon stimulated gene 15 (ISG15) from conjugated proteins. USP18 null mice in a FVB/N background develop tumors as early as 2 months of age. These tumors are leiomyosarcomas and thus represent a new murine model for this disease.

Monomethylarsonous Acid (Mmaiii) Has An Adverse Effect On The Innate Immune Response Of Human Bronchial Epithelial Cells To Pseudomonas Aeruginosa, Emily G. Notch, Britton C. Goodale, Roxanna Barnaby, Bonita Coutermarsh, Brent Berwin, Vivien F. Taylor, Brian P. Jackson, Bruce A. Stanton

Dartmouth Scholarship

Arsenic is the number one contaminant of concern with regard to human health according to the World Health Organization. Epidemiological studies on Asian and South American populations have linked arsenic exposure with an increased incidence of lung disease, including pneumonia, and chronic obstructive pulmonary disease, both of which are associated with bacterial infection. However, little is known about the effects of low dose arsenic exposure, or the contributions of organic arsenic to the innate immune response to bacterial infection. This study examined the effects on Pseudomonas aeruginosa (P. aeruginosa) induced cytokine secretion by human bronchial epithelial cells (HBEC) …

Serum Iron Level Is Associated With Time To Antibiotics In Cystic Fibrosis, Alex H. Gifford, Dana B. Dorman, Lisa A. Moulton, Jennifer E. Helm, Mary M. Griffin, Todd A. Mackenzie

Dartmouth Scholarship

Background:

Serum levels of hepcidin‐25, a peptide hormone that reduces blood iron content, are elevated when patients with cystic fibrosis (CF) develop pulmonary exacerbation (PEx). Because hepcidin‐25 is unavailable as a clinical laboratory test, we questioned whether a one‐time serum iron level was associated with the subsequent number of days until PEx, as defined by the need to receive systemic antibiotics (ABX) for health deterioration.

Methods:

Clinical, biochemical, and microbiological parameters were simultaneously checked in 54 adults with CF. Charts were reviewed to determine when they first experienced a PEx after these parameters were assessed. Time to ABX was compared …

Screening And Molecular Analysis Of Single Circulating Tumor Cells Using Micromagnet Array, Yu-Yen Huang, Peng Chen, Chun-Hsien Wu, Kazunori Hoshino, Konstantin Sokolov, Nancy Lane, Huaying Liu, Michael Huebschman, Eugene Frenkel, John X.J Zhang

Dartmouth Scholarship

Immunomagnetic assay has been developed to detect rare circulating tumor cells (CTCs), which shows clinical significance in cancer diagnosis and prognosis. The generation and fine-tuning of the magnetic field play essential roles in such assay toward effective single-cell-based analyses of target cells. However, the current assay has a limited range of field gradient, potentially leading to aggregation of cells and nanoparticles. Consequently, quenching of the fluorescence signal and mechanical damage to the cells may occur, which lower the system sensitivity and specificity. We develop a micromagnet-integrated microfluidic system for enhanced CTC detection. The ferromagnetic micromagnets, after being magnetized, generate localized …

Pleiotropic Effects Of Immune Responses Explain Variation In The Prevalence Of Fibroproliferative Diseases, Shirley B. Russell, Joan C. Smith, Minjun Huang, Joel S. Trupin, Scott M. Williams

Dartmouth Scholarship

Many diseases are differentially distributed among human populations. Differential selection on genetic variants in ancestral environments that coincidentally predispose to disease can be an underlying cause of these unequal prevalence patterns. Selected genes may be pleiotropic, affecting multiple phenotypes and resulting in more than one disease or trait. Patterns of pleiotropy may be helpful in understanding the underlying causes of an array of conditions in a population. For example, several fibroproliferative diseases are more prevalent and severe in populations of sub-Saharan ancestry. We propose that this disparity is due to selection for an enhanced Th2 response that confers resistance to …

Identification And Characterization Of The Interaction Site Between Cflipl And Calmodulin, Gabriel Gaidos, Alexandra E. Panaitiu, Bingqian Guo, Maria Pellegrini, Dale F. Mierke

Dartmouth Scholarship

Overexpression of the cellular FLICE-like inhibitory protein (cFLIP) has been reported in a number of tumor types. As an inactive procaspase-8 homologue, cFLIP is recruited to the intracellular assembly known as the Death Inducing Signaling Complex (DISC) where it inhibits apoptosis, leading to cancer cell proliferation. Here we characterize the molecular details of the interaction between cFLIP_L and calmodulin, a ubiquitous calcium sensing protein. By expressing the individual domains of cFLIP_L, we demonstrate that the interaction with calmodulin is mediated by the N-terminal death effector domain (DED1) of cFLIP_L. Additionally, we mapped the interaction to …

‘The Thing Is Not Knowing’: Patients' Perspectives On Surveillance Of An Indeterminate Pulmonary Nodule, Renda Soylemez Wiener, Michael K. Gould, Steven Woloshin, Lisa M. Schwartz, Jack Clark

Dartmouth Scholarship

Background: The hundreds of thousands of patients found to have a potentially malignant pulmonary nodule each year are faced with tremendous uncertainty regarding what the nodule is and how it should be evaluated.

Objective: To explore patients' responses to the detection and evaluation of a pulmonary nodule.

Long Non Coding Rna Malat1 Promotes Tumor Growth And Metastasis By Inducing Epithelial-Mesenchymal Transition In Oral Squamous Cell Carcinoma, Xuan Zhou, Su Liu, Guoshuai Cai, Lingping Kong, Tingting Zhang, Yu Ren, Yansheng Wu, Mei Mei, Lun Zhang, Xudong Wang

Dartmouth Scholarship

The prognosis of advanced oral squamous cell carcinoma (OSCC) patients remains dismal, and a better understanding of the underlying mechanisms is critical for identifying effective targets with therapeutic potential to improve the survival of patients with OSCC. This study aims to clarify the clinical and biological significance of metastasis-associated long non-coding RNA, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in OSCC. We found that MALAT1 is overexpressed in OSCC tissues compared to normal oral mucosa by real-time PCR. MALAT1 served as a new prognostic factor in OSCC patients. When knockdown by small interfering RNA (siRNA) in OSCC cell lines TSCCA and …

Dendritic Cell Autophagy Contributes To Herpes Simplex Virus-Driven Stromal Keratitis And Immunopathology, Yike Jiang, Xiaotang Yin, Patrick M. Stuart, David A. Leib

Dartmouth Scholarship

Herpetic stromal keratitis (HSK) is a blinding ocular disease that is initiated by HSV-1 and characterized by chronic inflammation in the cornea. Although HSK immunopathology of the cornea is well documented in animal models, events preceding this abnormal inflammatory cascade are poorly understood. In this study, we have examined the activation of pathological CD4T cells in the development of HSK. Dendritic cell autophagy (DC-autophagy) is an important pathway regulating ma- jor histocompatibility complex class II (MHCII)-dependent antigen presentation and proper CD4T cell activation during infectious diseases. Using DC-autophagy-deficient mice, we found that DC-autophagy significantly and specifically contributes to HSK disease …

Mannitol Does Not Enhance Tobramycin Killing Of Pseudomonas Aeruginosa In A Cystic Fibrosis Model System Of Biofilm Formation, Katherine E. Price, Giulia Orazi, Kathryn L. Ruoff, Wesley P. Hebert, George A. O'Toole, Paul Mastoridis

Dartmouth Scholarship

Cystic Fibrosis (CF) is a human genetic disease that results in the accumulation of thick, sticky mucus in the airways, which results in chronic, life-long bacterial biofilm infections that are difficult to clear with antibiotics. Pseudomonas aeruginosa lung infection is correlated with worsening lung disease and P. aeruginosa transitions to an antibiotic tolerant state during chronic infections. Tobramycin is an aminoglycoside currently used to combat lung infections in individuals with CF. While tobramycin is effective at eradicating P. aeruginosa in the airways of young patients, it is unable to completely clear the chronic P. aeruginosa infections in …

Cyclic Di-Gmp-Mediated Repression Of Swarming Motility By Pseudomonas Aeruginosa Pa14 Requires The Motab Stator, S. L. Kuchma, N. J. Delalez, L. M. Filkins, E. A. Snavely, J. P. Armitage, G. A. O'Toole

Dartmouth Scholarship

The second messenger cyclic diguanylate (c-di-GMP) plays a critical role in the regulation of motility. In Pseudomonas aeruginosa PA14, c-di-GMP inversely controls biofilm formation and surface swarming motility, with high levels of this dinucleotide signal stimulating biofilm formation and repressing swarming. P. aeruginosa encodes two stator complexes, MotAB and MotCD, that participate in the function of its single polar flagellum. Here we show that the repression of swarming motility requires a functional MotAB stator complex. Mutating the motAB genes restores swarming motility to a strain with artificially elevated levels of c-di-GMP as well as stimulates swarming in the wild-type strain, …

Meta-Gsa: Combining Findings From Gene-Set Analyses Across Several Genome-Wide Association Studies, Albert Rosenberger, Stefanie Friedrichs, Christopher I. Amos, Paul Brennan, Gordon Fehringer, Joachim Heinrich, Rayjean J. Hung, Thomas Muley, Martina Müller-Nurasyid, Angela Risch, Heike Bickeböller

Dartmouth Scholarship

Gene-set analysis (GSA) methods are used as complementary approaches to genome-wide association studies (GWASs). The single marker association estimates of a predefined set of genes are either contrasted with those of all remaining genes or with a null non-associated background. To pool the p-values from several GSAs, it is important to take into account the concordance of the observed patterns resulting from single marker association point estimates across any given gene set. Here we propose an enhanced version of Fisher’s inverse χ²-method META-GSA, however weighting each study to account for imperfect correlation between association patterns.

The Fungal Exopolysaccharide Galactosaminogalactan Mediates Virulence By Enhancing Resistance To Neutrophil Extracellular Traps, Mark J. Lee, Hong Liu, Bridget M. Barker, Brendan D. Snarr, Fabrice M. Gravelat, Qusai Al Abdallah, Christina Gavino, Shane R. Baistrocchi, Hanna Ostapska, Tianli Xiao, Benjamin Ralph, Norma V. Solis, Melanie Lehoux, Stefanie D. Baptista, Arsa Thammahong

Dartmouth Scholarship

Of the over 250 Aspergillus species, Aspergillus fumigatus accounts for up to 80% of invasive human infections. A. fumigatus produces galactosaminogalactan (GAG), an exopolysaccharide composed of galactose and N-acetyl-galactosamine (GalNAc) that mediates adherence and is required for full virulence. Less pathogenic Aspergillus species were found to produce GAG with a lower GalNAc content than A. fumigatus and expressed minimal amounts of cell wall-bound GAG. Increasing the GalNAc content of GAG of the minimally pathogenic A. nidulans, either through overexpression of the A. nidulans epimerase UgeB or by heterologous expression of the A. fumigatus epimerase …

Tobramycin-Treated Pseudomonas Aeruginosa Pa14 Enhances Streptococcus Constellatus 7155 Biofilm Formation In A Cystic Fibrosis Model System, Katherine E. E. Price, Amanda A. Naimie, Edward F. Griffin, Charles Bay, George A. O'Toole

Dartmouth Scholarship

Cystic fibrosis (CF) is a human genetic disorder which results in a lung environment that is highly conducive to chronic microbial infection. Over the past decade, deep-sequencing studies have demonstrated that the CF lung can harbor a highly diverse polymicrobial community. We expanded our existing in vitro model of Pseudomonas aeruginosa biofilm formation on CF-derived airway cells to include this broader set of CF airway colonizers to investigate their contributions to CF lung disease, particularly as they relate to the antibiotic response of the population. Using this system, we identified an interspecies interaction between P. aeruginosa, a bacterium associated with …