Medicine and Health Sciences Commons^™

Partition Decoupling For Multi-Gene Analysis Of Gene Expression Profiling Data, Rosemary Braun, Gregory Leibon, Scott Pauls, Daniel Rockmore

Dartmouth Scholarship

Background:

Multi-gene interactions likely play an important role in the development of complex phenotypes, and relationships between interacting genes pose a challenging statistical problem in microarray analysis, since the genes involved in these interactions may not exhibit marginal differential expression. As a result, it is necessary to develop tools that can identify sets of interacting genes that discriminate phenotypes without requiring that the classification boundary between phenotypes be convex.

Results:

We describe an extension and application of a new unsupervised statistical learning technique, known as the Partition Decoupling Method (PDM), to gene expression microarray data. This method may be used …

Prevalence And Risk Factors Of Major Depressive Disorder In Hiv/Aids As Seen In Semi-Urban Entebbe District, Uganda, Eugene Kinyanda, Susan Hoskins, Juliet Nakku, Saira Nawaz, Vikram Patel

Dartmouth Scholarship

Background:

Not much is known about the risk factors of major depressive disorder (MDD) in HIV/AIDS in the African socio-cultural context. Therefore a study was undertaken to examine the prevalence and risk factors of MDD in HIV/AIDS in semi-urban Uganda.

Methods:

A cross-sectional study was undertaken among 618 respondents attending two HIV clinics in Uganda.

Results:

Prevalence of MDD was 8.1%. Factors associated with MDD at univariate analysis only were female gender, family history of mental illness, negative coping style, alcohol dependency disorder, food insecurity and stress; not associated with MDD were social support, neurocognitive impairment, CD4 counts and BMI. …

Cd2ap Regulates Sumoylation Of Cin85 In Podocytes, Irini Tossidou, Rainer Niedenthal, Malte Klaus, Beina Teng, Kirstin Worthmann, Benjamin King, Kevin Peterson

Dartmouth Scholarship

Podocytes are highly differentiated and polarized epithelial cells located on the visceral side of the glomerulus. They form an indispensable component of the glomerular filter, the slit diaphragm, formed by several transmembrane proteins and adaptor molecules. Disruption of the slit diaphragm can lead to massive proteinuria and nephrotic syndrome in mice and humans. CD2AP is an adaptor protein that is important for the maintenance of the slit diaphragm. Together with its paralogue, CIN85, CD2AP belongs to a family of adaptor proteins that are primarily described as being involved in endocytosis and downregulation of receptor tyrosine kinase activity. We have shown …

Rice Consumption Contributes To Arsenic Exposure In Us Women, Diane Gilbert-Diamond, Kathryn L. Cottingham, Joann F. Gruber, Tracy Punshon, Vicki Sayarath, A. Jay Gandolfi, Emily R. Baker, Brian P. Jackson, Carol L. Folt, Margaret R. Karagas

Dartmouth Scholarship

Emerging data indicate that rice consumption may lead to potentially harmful arsenic exposure. However, few human data are available, and virtually none exist for vulnerable periods such as pregnancy. Here we document a positive association between rice consumption and urinary arsenic excretion, a biomarker of recent arsenic exposure, in 229 pregnant women. At a 6-mo prenatal visit, we collected a urine sample and 3-d dietary record for water, fish/seafood, and rice. We also tested women's home tap water for arsenic, which we combined with tap water consumption to estimate arsenic exposure through water. Women who reported rice intake (n …

Combined Fluorescence And Reflectance Spectroscopy For In Vivo Quantification Of Cancer Biomarkers In Low- And High-Grade Glioma Surgery, Pablo A. ValdéS, Anthony Kim, Keith D. Paulsen, Frederic Leblond, Olga M. Conde, Brent T. Harris, David W. Roberts

Dartmouth Scholarship

Biomarkers are indicators of biological processes and hold promise for the diagnosis and treatment of disease. Gliomas represent a heterogeneous group of brain tumors with marked intra- and inter-tumor variability. The extent of surgical resection is a significant factor influencing post-surgical recurrence and prognosis. Here, we used fluorescence and reflectance spectral signatures for in vivo quantification of multiple biomarkers during glioma surgery, with fluorescence contrast provided by exogenously-induced protoporphyrin IX (PpIX) following administration of 5-aminolevulinic acid. We performed light-transport modeling to quantify multiple biomarkers indicative of tumor biological processes, including the local concentration of PpIX and associated photoproducts, total hemoglobin …

Chromosome Missegregation In Human Cells Arises Through Specific Types Of Kinetochore–Microtubule Attachment Errors, Sarah L. Thompson, Duane A. Compton

Dartmouth Scholarship

Most solid tumors are aneuploid, and many missegregate chromosomes at high rates in a phenomenon called chromosomal instability (CIN). CIN reflects the erosion of mitotic fidelity, and it correlates with poor patient prognosis and drug resistance. The most common mechanism causing CIN is the persistence of improper kinetochore–microtubule attachments called merotely. Chromosomes with merotelic kinetochores often manifest as lagging chromosomes in anaphase, suggesting that lagging chromosomes fail to segregate properly. However, it remains unknown whether the lagging chromosomes observed in anaphase segregate to the correct or incorrect daughter cell. To address this question, we tracked the segregation of a single …

Characterization Of Street Food Consumption In Palermo: Possible Effects On Health, Silvio Buscemi, Annamaria Barile, Vincenza Maniaci, John A. Batsis

Dartmouth Scholarship

Background: Street Food (SF) consists of out-of-home food consumption and has old, historical roots with complex social-economic and cultural implications. Despite the emergence of modern fast food, traditional SF persists worldwide, but the relationship of SF consumption with overall health, well-being, and obesity is unknown.

Methods: This is an observational, cross-sectional study. The study was performed in Palermo, the largest town of Sicily, Italy. Two groups were identified: consumers of SF (n = 687) and conventional restaurant food (RES) consumers (n = 315). Study subjects answered a questionnaire concerning their health conditions, nutritional preferences, frequency of consumption of SF and …

Strain-Dependent Variation In The Early Transcriptional Response To Cns Injury Using A Cortical Explant System, David J. Graber, Brent T. Harris, William F. Hickey

Dartmouth Scholarship

While it is clear that inbred strains of mice have variations in immunological responsiveness, the influence of genetic background following tissue damage in the central nervous system is not fully understood. A cortical explant system was employed as a model for injury to determine whether the immediate transcriptional response to tissue resection revealed differences among three mouse strains. Immunological mRNAs were measured in cerebral cortex from SJL/J, C57BL/6J, and BALB/cJ mice using real time RT-PCR. Freshly isolated cortical tissue and cortical sections incubated in explant medium were examined. Levels of mRNA, normalized to β-actin, were compared using one way analysis …

Supplier-Induced Demand For Psychiatric Admissions In Northern New England, Bradley V. Watts, Brian Shiner, Gunnar Klauss, William B. Weeks

Dartmouth Scholarship

The development of hospital service areas (HSAs) using small area analysis has been useful in examining variation in medical and surgical care; however, the techniques of small area analysis are underdeveloped in understanding psychiatric admission rates. We sought to develop these techniques in order to understand the relationship between psychiatric bed supply and admission rates in Northern New England. Our primary hypotheses were that there would be substantial variation in psychiatric admission across geographic settings and that bed availability would be positively correlated with admission rates, reflecting a supplier-induced demand phenomenon. Our secondary hypothesis was that the construction of psychiatric …

Protoporphyrin Ix Fluorescence Contrast In Invasive Glioblastomas Is Linearly Correlated With Gd Enhanced Magnetic Resonance Image Contrast But Has Higher Diagnostic Accuracy, Kimberley S. Samkoe, Summer L. Gibbs-Strauss, Harold H. Yang, S. Khan Hekmatyar, P. Jack Hoopes, Julia A. O'Hara, Risto A. Kauppinen, Brian W. Pogue

Dartmouth Scholarship

The sensitivity and specificity of in vivo magnetic resonance (MR) imaging is compared with production of protoporphyrin IX (PpIX), determined ex vivo, in a diffusely infiltrating glioma. A human glioma transfected with green fluorescent protein, displaying diffuse, infiltrative growth, was implanted intracranially in athymic nude mice. Image contrast from corresponding regions of interest (ROIs) in in vivo MR and ex vivo fluorescence images was quantified. It was found that all tumor groups had statistically significant PpIX fluorescence contrast and that PpIX contrast demonstrated the best predictive power for tumor presence. Contrast from gadolinium enhanced T1-weighted (T1W+Gd) and absolute T2 …

Alpha-Defensins 1-3 Release By Dendritic Cells Is Reduced By Estrogen, Maria M. Escribese, Marta Rodríguez-García, Rhoda Sperling, Stephanie M. Engel

Dartmouth Scholarship

During pregnancy the immune system of the mother must protect any activation that may negatively affect the fetus. Changes in susceptibility to infection as well as resolution of some autoimmune disorders represent empirical evidence for pregnancy related alterations in immunity. Sex hormones reach extremely high levels during pregnancy and have been shown to have direct effects on many immune functions including the antiviral response of dendritic cells. Among the immunologically active proteins secreted by monocyte derived DCs (MDDC) are the alpha-defensins 1-3. This family of cationic antimicrobial peptides has a broad spectrum of microbicidal activity and has also been shown …

Assessing Medicare Beneficiaries’ Strength‐Of‐Preference Scores For Health Care Options: How Engaging Does The Elicitation Technique Need To Be?, Trafford Crump, Hilary A. Llewellyn-Thomas

Dartmouth Scholarship

The objective was to determine if participants’ strength‐of‐preference scores for elective health care interventions at the end‐of‐life (EOL) elicited using a non‐engaging technique are affected by their prior use of an engaging elicitation technique.

Genetic Determinants Of Uv-Susceptibility In Non-Melanoma Skin Cancer, Marleen M. Welsh, Margaret R. Karagas, Jacquelyn K. Kuriger, Andres Houseman, Steven K. Spencer, Ann E. Perry, Heather H. Nelson

Dartmouth Scholarship

A milieu of cytokines and signaling molecules are involved in the induction of UV-induced immune suppression and thus the etiology of non-melanoma skin cancer (NMSC). Targeting the UV-induced immunosuppression pathway, and using a large population based study of NMSC, we have investigated the risk associated with functional variants in 10 genes (IL10, IL4, IL4R, TNF, TNFR2, HTR2A, HRH2, IL12B, PTGS2, and HAL). The most prominent single genetic effect was observed for IL10. There was increasing risk for both basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) with …

Decision Quality Instrument For Treatment Of Hip And Knee Osteoarthritis: A Psychometric Evaluation, Karen R. Sepucha, Dawn Stacey, Catharine F. Clay, Yuchiao Chang

Dartmouth Scholarship

A high quality decision requires that patients who meet clinical criteria for surgery are informed about the options (including non-surgical alternatives) and receive treatments that match their goals. The aim of this study was to evaluate the psychometric properties and clinical sensibility of a patient self report instrument, to measure the quality of decisions about total joint replacement for knee or hip osteoarthritis.

Remote Positioning Optical Breast Magnetic Resonance Coil For Slice-Selection During Image-Guided Near-Infrared Spectroscopy Of Breast Cancer, Michael A. Mastanduno, Shudong Jiang, Brian W. Pogue, Keith D. Paulsen, Roberta Diflorio-Alexander

Dartmouth Scholarship

The design and testing of a pneumatic optical positioning interface produced with the goal of improving fiber positioning in magnetic resonance (MR)-guided diffuse spectral imaging of breast cancer is presented. The system was created for vertical positioning of optical fibers inside the MR bore during a patient exam to target suspicious lesions with MR scans for reference and collect multiple planes of optical data. The interface includes new fiber plates for mechanical and optical coupling to the breast, and was tested in phantoms and human imaging. Reconstructions with data taken in the new interface show acceptable linearity over different absorber …

Variations In Mre11/Rad50/Nbs1 Status And Dna Damage-Induced S-Phase Arrest In The Cell Lines Of The Nci60 Panel, Kristen M. K. Garner, Alan Eastman

Dartmouth Scholarship

The Mre11/Rad50/Nbs1 (MRN) complex is a regulator of cell cycle checkpoints and DNA repair. Defects in MRN can lead to defective S-phase arrest when cells are damaged. Such defects may elicit sensitivity to selected drugs providing a chemical synthetic lethal interaction that could be used to target therapy to tumors with these defects. The goal of this study was to identify these defects in the NCI60 panel of cell lines and identify compounds that might elicit selective cytotoxicity.

An Evaluation Of The Emerging Interventions Against Respiratory Syncytial Virus (Rsv)-Associated Acute Lower Respiratory Infections In Children, Harish Nair, Vasundhara R. Verma, Evropi Theodoratou, Lina Zgaga, Tanvir Huda, Eric Af Simoes, Peter F. Wright, Igor Rudan, Harry Campbell

Dartmouth Scholarship

Background: Respiratory Syncytial Virus (RSV) is the leading cause of acute lower respiratory infections (ALRI) in children. It is estimated to cause approximately 33.8 million new episodes of ALRI in children annually, 96% of these occurring in developing countries. It is also estimated to result in about 53,000 to 199,000 deaths annually in young children. Currently there are several vaccine and immunoprophylaxis candidates against RSV in the developmental phase targeting active and passive immunization.

Methods: We used a modified CHNRI methodology for setting priorities in health research investments. This was done in two stages. In Stage I, we systematically reviewed …

Crystal Structure Of A Charge Engineered Human Lysozyme Having Enhanced Bactericidal Activity, Avinash Gill, Thomas C. Scanlon, Daniel C. Osipovitch, Dean R. Madden, Karl E. Griswold

Dartmouth Scholarship

Human lysozyme is a key component of the innate immune system, and recombinant forms of the enzyme represent promising leads in the search for therapeutic agents able to treat drug-resistant infections. The wild type protein, however, fails to participate effectively in clearance of certain infections due to inherent functional limitations. For example, wild type lysozymes are subject to electrostatic sequestration and inactivation by anionic biopolymers in the infected airway. A charge engineered variant of human lysozyme has recently been shown to possess improved antibacterial activity in the presence of disease associated inhibitory molecules. Here, the 2.04 A ̊ crystal structure …

Rho Activation Of Mdia Formins Is Modulated By An Interaction With Inverted Formin 2 (Inf2), Hua Sun, Johannes S. Schlondorff, Elizabeth J. Brown, Henry N. Higgs, Martin R. Pollak

Dartmouth Scholarship

Inverted formin 2 (INF2) encodes a member of the diaphanous subfamily of formin proteins. Mutations in INF2 cause human kidney disease characterized by focal and segmental glomerulosclerosis. Disease-causing mutations occur only in the diaphanous inhibitory domain (DID), suggesting specific roles for this domain in the pathogenesis of disease. In a yeast two-hybrid screen, we identified the diaphanous autoregulatory domains (DADs) of the mammalian diaphanous-related formins (mDias) mDia1, mDia2, and mDia 3 as INF2_DID-interacting partners. The mDias are Rho family effectors that regulate actin dynamics. We confirmed in vitro INF2_DID/mDia_DAD binding by biochemical assays, confirmed the in vivo interaction of these …

Correction: Epistatic Interactions In Genetic Regulation Of T-Pa And Pai-1 Levels In A Ghanaian Population, Nadia M. Penrod, Kwabena A. Poku, Douglas E. Vaughn, Folkert W. Asselbergs, Nancy J. Brown, Jason H. Moore, Scott M. Williams

Dartmouth Scholarship

The proteins, tissue plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1), act in concert to balance thrombus formation and degradation, thereby modulating the development of arterial thrombosis and excessive bleeding. PAI-1 is upregulated by the renin-angiotensin system (RAS), specifically by angiotensin II, the product of angiotensin converting enzyme (ACE) cleavage of angiotensin I, which is produced by the cleavage of angiotensinogen (AGT) by renin (REN). ACE indirectly stimulates the release of t-PA which, in turn, activates the corresponding fibrinolytic system. Single polymorphisms in these pathways have been shown to significantly impact plasma levels of t-PA and PAI-1 differently in …