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Full-Text Articles in Medicine and Health Sciences

Building A Statistical Model For Predicting Cancer Genes, Ivan P. Gorlov, Christopher J. Logothetis, Shenying Fang, Olga Y. Gorlova, Christopher Amos Nov 2012

Building A Statistical Model For Predicting Cancer Genes, Ivan P. Gorlov, Christopher J. Logothetis, Shenying Fang, Olga Y. Gorlova, Christopher Amos

Dartmouth Scholarship

More than 400 cancer genes have been identified in the human genome. The list is not yet complete. Statistical models predicting cancer genes may help with identification of novel cancer gene candidates. We used known prostate cancer (PCa) genes (identified through KnowledgeNet) as a training set to build a binary logistic regression model identifying PCa genes. Internal and external validation of the model was conducted using a validation set (also from KnowledgeNet), permutations, and external data on genes with recurrent prostate tumor mutations. We evaluated a set of 33 gene characteristics as predictors. Sixteen of the original 33 predictors were …


Molecular Mechanism For Depolarization-Induced Modulation Of Kv Channel Closure, Alain J. Labro, Jerome J. Lacroix, Carlos A. Villalba-Galea, Dirk J. Snyders, Francisco Bezanilla Nov 2012

Molecular Mechanism For Depolarization-Induced Modulation Of Kv Channel Closure, Alain J. Labro, Jerome J. Lacroix, Carlos A. Villalba-Galea, Dirk J. Snyders, Francisco Bezanilla

School of Pharmacy Faculty Articles

Voltage-dependent potassium (Kv) channels provide the repolarizing power that shapes the action potential duration and helps control the firing frequency of neurons. The K(+) permeation through the channel pore is controlled by an intracellularly located bundle-crossing (BC) gate that communicates with the voltage-sensing domains (VSDs). During prolonged membrane depolarizations, most Kv channels display C-type inactivation that halts K(+) conduction through constriction of the K(+) selectivity filter. Besides triggering C-type inactivation, we show that in Shaker and Kv1.2 channels (expressed in Xenopus laevis oocytes), prolonged membrane depolarizations also slow down the kinetics of VSD deactivation and BC gate closure during the …


Contribution Of The Staphylococcus Aureus Atl Am And Gl Murein Hydrolase Activities In Cell Division, Autolysis, And Biofilm Formation., Jeffrey L. Bose, Mckenzie K. Lehman, Paul D. Fey, Kenneth W. Bayles Jul 2012

Contribution Of The Staphylococcus Aureus Atl Am And Gl Murein Hydrolase Activities In Cell Division, Autolysis, And Biofilm Formation., Jeffrey L. Bose, Mckenzie K. Lehman, Paul D. Fey, Kenneth W. Bayles

Journal Articles: Pathology and Microbiology

The most prominent murein hydrolase of Staphylococcus aureus, AtlA, is a bifunctional enzyme that undergoes proteolytic cleavage to yield two catalytically active proteins, an amidase (AM) and a glucosaminidase (GL). Although the bifunctional nature of AtlA has long been recognized, most studies have focused on the combined functions of this protein in cell wall metabolism and biofilm development. In this study, we generated mutant derivatives of the clinical S. aureus isolate, UAMS-1, in which one or both of the AM and GL domains of AtlA have been deleted. Examination of these strains revealed that each mutant exhibited growth rates comparable …


Improved Tumor Contrast Achieved By Single Time Point Dual-Reporter Fluorescence Imaging, Kenneth M. Tichauer, Kimberley S. Samkoe, Kristian J. Sexton, Jason R. Gunn, Tayyaba Hasan, Brian W. Pogue May 2012

Improved Tumor Contrast Achieved By Single Time Point Dual-Reporter Fluorescence Imaging, Kenneth M. Tichauer, Kimberley S. Samkoe, Kristian J. Sexton, Jason R. Gunn, Tayyaba Hasan, Brian W. Pogue

Dartmouth Scholarship

In this study, we demonstrate a method to quantify biomarker expression that uses an exogenous dual-reporter imaging approach to improve tumor signal detection. The uptake of two fluorophores, one nonspecific and one targeted to the epidermal growth factor receptor (EGFR), were imaged at 1 h in three types of xenograft tumors spanning a range of EGFR expression levels (n  =  6 in each group). Using this dual-reporter imaging methodology, tumor contrast-to-noise ratio was amplified by >6 times at 1 h postinjection and >2 times at 24 h. Furthermore, by as early as 20 min postinjection, the dual-reporter imaging signal …


Ovarian Cancer Progression Is Controlled By Phenotypic Changes In Dendritic Cells, Uciane K. Scarlett, Melanie R. Rutkowski, Adam M. Rauwerdink, Jennifer Fields, Ximena Escovar-Fadul, Jason Baird, Juan R. Cubillos-Ruiz, Ana C. Jacobs, Jorge L. Gonzalez, John Weaver, Steven Fiering, Jose R. Conejo-Garcia Feb 2012

Ovarian Cancer Progression Is Controlled By Phenotypic Changes In Dendritic Cells, Uciane K. Scarlett, Melanie R. Rutkowski, Adam M. Rauwerdink, Jennifer Fields, Ximena Escovar-Fadul, Jason Baird, Juan R. Cubillos-Ruiz, Ana C. Jacobs, Jorge L. Gonzalez, John Weaver, Steven Fiering, Jose R. Conejo-Garcia

Dartmouth Scholarship

We characterized the initiation and evolution of the immune response against a new inducible p53-dependent model of aggressive ovarian carcinoma that recapitulates the leukocyte infiltrates and cytokine milieu of advanced human tumors. Unlike other models that initiate tumors before the development of a mature immune system, we detect measurable antitumor immunity from very early stages, which is driven by infiltrating dendritic cells (DCs) and prevents steady tumor growth for prolonged periods. Coinciding with a phenotypic switch in expanding DC infiltrates, tumors aggressively progress to terminal disease in a comparatively short time. Notably, tumor cells remain immunogenic at advanced stages, but …


Regulation Of A Duplicated Locus: Drosophila Sloppy Paired Is Replete With Functionally Overlapping Enhancers., Miki Fujioka, James B Jaynes Feb 2012

Regulation Of A Duplicated Locus: Drosophila Sloppy Paired Is Replete With Functionally Overlapping Enhancers., Miki Fujioka, James B Jaynes

Department of Biochemistry and Molecular Biology Faculty Papers

In order to investigate regulation and redundancy within the sloppy paired (slp) locus, we analyzed 30 kilobases of DNA encompassing the tandem, coordinately regulated slp1 and slp2 transcription units. We found a remarkable array of stripe enhancers with overlapping activities surrounding the slp1 transcription unit, and, unexpectedly, glial cell enhancers surrounding slp2. The slp stripe regulatory region generates 7 stripes at blastoderm, and later 14 stripes that persist throughout embryogenesis. Phylogenetic analysis among drosophilids suggests that the multiplicity of stripe enhancers did not evolve through recent duplication. Most of the direct integration among cis-regulatory modules appears to be simply additive, …


Scd1 Plays A Tumor-Suppressive Role In Survival Of Leukemia Stem Cells And The Development Of Chronic Myeloid Leukemia, H Zhang, H Li, N Ho, Dongguang Li, Shaoguang Li Jan 2012

Scd1 Plays A Tumor-Suppressive Role In Survival Of Leukemia Stem Cells And The Development Of Chronic Myeloid Leukemia, H Zhang, H Li, N Ho, Dongguang Li, Shaoguang Li

Research outputs 2012

Chronic myeloid leukemia (CML) is derived from a stem cell, and it is widely accepted that the existence of leukemia stem cells (LSCs) is one of the major reasons for the relapse of CML treated with kinase inhibitors. Key to eradicating LSCs is to identify genes that play a critical role in survival regulation of these stem cells. Using BCR-ABL-induced CML mouse model, here we show that expression of the stearoyl-CoA desaturase 1 (Scd1) gene is downregulated in LSCs and that Scd1 plays a tumor-suppressive role in LSCs with no effect on the function of normal hematopoietic stem cells. Deletion …


Clinical And Biomarker Changes In Dominantly Inherited Alzheimer's Disease, R J Bateman, C Xiong, T L Benzinger, A M Fagan, A Goate, N C Fox, D S Marcus, N J Cairns, X Xie, T M Blazey, D M Holtzman, A Santacruz, V Buckles, A Oliver, K Moulder, P M Aisen, B Ghetti, W M Klunk, E Mcdade, Ralph Martins, C M Masters, R Mayeux, J M Ringman, M M Rossor, P M Schofield, R M Sperling, S Salloway, J M Morris Jan 2012

Clinical And Biomarker Changes In Dominantly Inherited Alzheimer's Disease, R J Bateman, C Xiong, T L Benzinger, A M Fagan, A Goate, N C Fox, D S Marcus, N J Cairns, X Xie, T M Blazey, D M Holtzman, A Santacruz, V Buckles, A Oliver, K Moulder, P M Aisen, B Ghetti, W M Klunk, E Mcdade, Ralph Martins, C M Masters, R Mayeux, J M Ringman, M M Rossor, P M Schofield, R M Sperling, S Salloway, J M Morris

Research outputs 2012

BACKGROUND: The order and magnitude of pathologic processes in Alzheimer's disease are not well understood, partly because the disease develops over many years. Autosomal dominant Alzheimer's disease has a predictable age at onset and provides an opportunity to determine the sequence and magnitude of pathologic changes that culminate in symptomatic disease. METHODS: In this prospective, longitudinal study, we analyzed data from 128 participants who underwent baseline clinical and cognitive assessments, brain imaging, and cerebrospinal fluid (CSF) and blood tests. We used the participant's age at baseline assessment and the parent's age at the onset of symptoms of Alzheimer's disease to …


Genes Adopt Non-Optimal Codon Usage To Generate Cell Cycle-Dependent Oscillations In Protein Levels., Milana Frenkel-Morgenstern, Tamar Danon, Thomas Christian, Takao Igarashi, Lydia Cohen, Ya-Ming Hou, Lars Juhl Jensen Jan 2012

Genes Adopt Non-Optimal Codon Usage To Generate Cell Cycle-Dependent Oscillations In Protein Levels., Milana Frenkel-Morgenstern, Tamar Danon, Thomas Christian, Takao Igarashi, Lydia Cohen, Ya-Ming Hou, Lars Juhl Jensen

Department of Biochemistry and Molecular Biology Faculty Papers

The cell cycle is a temporal program that regulates DNA synthesis and cell division. When we compared the codon usage of cell cycle-regulated genes with that of other genes, we discovered that there is a significant preference for non-optimal codons. Moreover, genes encoding proteins that cycle at the protein level exhibit non-optimal codon preferences. Remarkably, cell cycle-regulated genes expressed in different phases display different codon preferences. Here, we show empirically that transfer RNA (tRNA) expression is indeed highest in the G2 phase of the cell cycle, consistent with the non-optimal codon usage of genes expressed at this time, and lowest …