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Full-Text Articles in Life Sciences

P53'S Choice Of Myocardial Death Or Survival: Oxygen Protects Infarct Myocardium By Recruiting P53 On Nos3 Promoter Through Regulation Of P53-Lys118 Acetylation, Rajan Gogna, Esha Madan, Mahmood Khan, Uttam Pati, Periannan Kuppusamy Aug 2013

P53'S Choice Of Myocardial Death Or Survival: Oxygen Protects Infarct Myocardium By Recruiting P53 On Nos3 Promoter Through Regulation Of P53-Lys118 Acetylation, Rajan Gogna, Esha Madan, Mahmood Khan, Uttam Pati, Periannan Kuppusamy

Dartmouth Scholarship

Myocardial infarction, an irreversible cardiac tissue damage, involves progressive loss of cardiomyocytes due to p53-mediated apoptosis. Oxygenation is known to promote cardiac survival through activation of NOS3 gene. We hypothesized a dual role for p53, which, depending on oxygenation, can elicit apoptotic death signals or NOS3-mediated survival signals in the infarct heart. p53 exhibited a differential DNA-binding, namely, BAX-p53RE in the infarct heart or NOS3-p53RE in the oxygenated heart, which was regulated by oxygen-induced, post- translational modification of p53. In the infarct heart, p53 was heavily acetylated at Lys118 residue, which was exclusively reversed in the oxygenated heart, apparently regulated …


Coupling S100a4 To Rhotekin Alters Rho Signaling Output In Breast Cancer Cells, Min Chen, Anne R. Bresnick, Kathleen L. O'Connor Aug 2013

Coupling S100a4 To Rhotekin Alters Rho Signaling Output In Breast Cancer Cells, Min Chen, Anne R. Bresnick, Kathleen L. O'Connor

Markey Cancer Center Faculty Publications

Rho signaling is increasingly recognized to contribute to invasion and metastasis. In this study, we discovered that metastasis-associated protein S100A4 interacts with the Rho-binding domain (RBD) of Rhotekin, thus connecting S100A4 to the Rho pathway. Glutathione S-transferase pull-down and immunoprecipitation assays demonstrated that S100A4 specifically and directly binds to Rhotekin RBD, but not the other Rho effector RBDs. S100A4 binding to Rhotekin is calcium-dependent and uses residues distinct from those bound by active Rho. Interestingly, we found that S100A4 and Rhotekin can form a complex with active RhoA. Using RNA interference, we determined that suppression of both S100A4 and …


Down's Syndrome, Neroinflammation, And Alzheimer Neuropathogenesis, Donna M. Wilcock, W. Sue T. Griffin Jul 2013

Down's Syndrome, Neroinflammation, And Alzheimer Neuropathogenesis, Donna M. Wilcock, W. Sue T. Griffin

Physiology Faculty Publications

Down syndrome (DS) is the result of triplication of chromosome 21 (trisomy 21) and is the prevailing cause of mental retardation. In addition to the mental deficiencies and physical anomalies noted at birth, triplication of chromosome 21 gene products results in the neuropathological and cognitive changes of Alzheimer's disease (AD). Mapping of the gene that encodes the precursor protein (APP) of the β-amyloid (Aβ) present in the Aβ plaques in both AD and DS to chromosome 21 was strong evidence that this chromosome 21 gene product was a principal neuropathogenic culprit in AD as well as DS. The discovery of …


Endocytic Trafficking Of Nanoparticles Delivered By Cell-Penetrating Peptides Comprised Of Nona-Arginine And A Penetration Accelerating Sequence, Betty Revon Liu, Shih-Yen Lo, Chia-Chin Liu, Chia-Lin Chyan, Yue-Wern Huang, Robert Aronstam, Han-Jung Lee Jun 2013

Endocytic Trafficking Of Nanoparticles Delivered By Cell-Penetrating Peptides Comprised Of Nona-Arginine And A Penetration Accelerating Sequence, Betty Revon Liu, Shih-Yen Lo, Chia-Chin Liu, Chia-Lin Chyan, Yue-Wern Huang, Robert Aronstam, Han-Jung Lee

Biological Sciences Faculty Research & Creative Works

Cell-penetrating peptides (CPPs) can traverse cellular membranes and deliver biologically active molecules into cells. In this study, we demonstrate that CPPs comprised of nona-arginine (R9) and a penetration accelerating peptide sequence (Pas) that facilitates escape from endocytic lysosomes, denoted as PR9, greatly enhance the delivery of noncovalently associated quantum dots (QDs) into human A549 cells. Mechanistic studies, intracellular trafficking analysis and a functional gene assay reveal that endocytosis is the main route for intracellular delivery of PR9/QD complexes. Endocytic trafficking of PR9/QD complexes was monitored using both confocal and transmission electron microscopy (TEM). Zeta-potential and size analyses indicate the importance …


Discovering Chromatin Motifs Using Faire Sequencing And The Human Diploid Genome, Chia-Chun Yang, Michael J. Buck, Min-Hsuan Chen, Yun-Fan Chen, Hsin-Chi Lan, Jeremy J.W Chen, Chao Cheng, Chun-Chi Liu May 2013

Discovering Chromatin Motifs Using Faire Sequencing And The Human Diploid Genome, Chia-Chun Yang, Michael J. Buck, Min-Hsuan Chen, Yun-Fan Chen, Hsin-Chi Lan, Jeremy J.W Chen, Chao Cheng, Chun-Chi Liu

Dartmouth Scholarship

Background: Specific chromatin structures are associated with active or inactive gene transcription. The gene regulatory elements are intrinsically dynamic and alternate between inactive and active states through the recruitment of DNA binding proteins, such as chromatin-remodeling proteins. Results: We developed a unique genome-wide method to discover DNA motifs associated with chromatin accessibility using formaldehyde-assisted isolation of regulatory elements with high-throughput sequencing (FAIRE-seq). We aligned the FAIRE-seq reads to the GM12878 diploid genome and subsequently identified differential chromatin-state regions (DCSRs) using heterozygous SNPs. The DCSR pairs represent the locations of imbalances of chromatin accessibility between alleles and are ideal to reveal …


Key Genes For Modulating Information Flow Play A Temporal Role As Breast Tumor Coexpression Networks Are Dynamically Rewired By Letrozole, Nadia M. Penrod, Jason H. Moore May 2013

Key Genes For Modulating Information Flow Play A Temporal Role As Breast Tumor Coexpression Networks Are Dynamically Rewired By Letrozole, Nadia M. Penrod, Jason H. Moore

Dartmouth Scholarship

Genes do not act in isolation but instead as part of complex regulatory networks. To understand how breast tumors adapt to the presence of the drug letrozole, at the molecular level, it is necessary to consider how the expression levels of genes in these networks change relative to one another. Using transcriptomic data generated from sequential tumor biopsy samples, taken at diagnosis, following 10-14 days and following 90 days of letrozole treatment, and a pairwise partial orrelation statistic, we build temporal gene coexpression networks. We characterize the structure of each network and identify genes that hold prominent positions for maintaining …


Intracellular Delivery Of Nanoparticles And Dnas By Ir9 Cell-Penetrating Peptides, Betty Revon Liu, Ji-Sing Liou, Yue-Wern Huang, Robert Aronstam, Han-Jung Lee May 2013

Intracellular Delivery Of Nanoparticles And Dnas By Ir9 Cell-Penetrating Peptides, Betty Revon Liu, Ji-Sing Liou, Yue-Wern Huang, Robert Aronstam, Han-Jung Lee

Biological Sciences Faculty Research & Creative Works

Cell-penetrating peptides (CPPs) comprised of basic amino residues are able to cross cytoplasmic membranes and are able to deliver biologically active molecules inside cells. However, CPP/cargo entrapment in endosome limits biomedical utility as cargoes are destroyed in the acidic environment. In this study, we demonstrate protein transduction of a novel CPP comprised of an INF7 fusion peptide and nona-arginine (designated IR9). IR9 noncovalently interacts with quantum dots (QDs) and DNAs to form stable IR9/QD and IR9/DNA complexes which are capable of entering human A549 cells. Zeta-potentials were a better predictor of transduction efficiency than gel shift analysis, emphasizing the importance …


Chemically Diverse Microtubule Stabilizing Agents Initiate Distinct Mitotic Defects And Dysregulated Expression Of Key Mitotic Kinases., Cristina C. Rohena, Jiangnan Peng, Tyler A. Johnson, Phillip Crews, Susan L. Mooberry Apr 2013

Chemically Diverse Microtubule Stabilizing Agents Initiate Distinct Mitotic Defects And Dysregulated Expression Of Key Mitotic Kinases., Cristina C. Rohena, Jiangnan Peng, Tyler A. Johnson, Phillip Crews, Susan L. Mooberry

Natural Sciences and Mathematics | Faculty Scholarship

Microtubule stabilizers are some of the most successful drugs used in the treatment of adult solid tumors and yet the molecular events responsible for their antimitotic actions are not well defined. The mitotic events initiated by three structurally and biologically diverse microtubule stabilizers; taccalonolide AJ, laulimalide/fijianolide B and paclitaxel were studied. These microtubule stabilizers cause the formation of aberrant, but structurally distinct mitotic spindles leading to the hypothesis that they differentially affect mitotic signaling. Each microtubule stabilizer initiated different patterns of expression of key mitotic signaling proteins. Taccalonolide AJ causes centrosome separation and disjunction failure to a much greater extent …


Side Chain Requirements For Affinity And Specificity In D5, An Hiv-1 Antibody Derived From The Vh1-69 Germline Segment, Alex Stewart, Joseph S. Harrison, Lauren K. Regula, Jonathan R. Lai Apr 2013

Side Chain Requirements For Affinity And Specificity In D5, An Hiv-1 Antibody Derived From The Vh1-69 Germline Segment, Alex Stewart, Joseph S. Harrison, Lauren K. Regula, Jonathan R. Lai

College of the Pacific Faculty Articles

BACKGROUND: Analysis of factors contributing to high affinity antibody-protein interactions provides insight into natural antibody evolution, and guides the design of antibodies with new or enhanced function. We previously studied the interaction between antibody D5 and its target, a designed protein based on HIV-1 gp41 known as 5-Helix, as a model system [Da Silva, G. F.; Harrison, J. S.; Lai, J. R., Biochemistry, 2010, 49, 5464-5472]. Antibody D5 represents an interesting case study because it is derived from the VH1-69 germline segment; this germline segment is characterized by a hydrophobic second heavy chain complementarity determining region (HCDR2) that constitutes the …


Humans And Dolphins: An Exploration Of Anthropocentrism In Applied Environmental Ethics, Thomas I. White Apr 2013

Humans And Dolphins: An Exploration Of Anthropocentrism In Applied Environmental Ethics, Thomas I. White

Management Faculty Works

This article argues that one of the reasons that the unethical character of much human-dolphin contact is not more apparent to ethicists is that discussion of central issues has been colored with unintentional species bias. This article points out weaknesses in the traditional approach to discussing topics that bear on the question of whether dolphins have moral standing. It demonstrates that discussions of the cognitive abilities of dolphins by Steven Wise and Alasdair MacIntyre are unintentionally but fundamentally anthropocentric-largely because the authors are not familiar with enough of the scientific literature about dolphins to draw the conclusions that they do.


Fuzzy Complex Formation Between The Intrinsically Disordered Prothymosin Α And The Kelch Domain Of Keap1 Involved In The Oxidative Stress Response., Halema Khan, Elio A Cino, Anne Brickenden, Jingsong Fan, Daiwen Yang, Wing-Yiu Choy Mar 2013

Fuzzy Complex Formation Between The Intrinsically Disordered Prothymosin Α And The Kelch Domain Of Keap1 Involved In The Oxidative Stress Response., Halema Khan, Elio A Cino, Anne Brickenden, Jingsong Fan, Daiwen Yang, Wing-Yiu Choy

Biochemistry Publications

Kelch-like ECH-associated protein 1 (Keap1) is an inhibitor of nuclear factor erythroid 2-related factor 2 (Nrf2), a key transcription factor for cytoprotective gene activation in the oxidative stress response. Under unstressed conditions, Keap1 interacts with Nrf2 in the cytoplasm via its Kelch domain and suppresses the transcriptional activity of Nrf2. During oxidative stress, Nrf2 is released from Keap1 and is translocated into the nucleus, where it interacts with the small Maf protein to initiate gene transcription. Prothymosin α (ProTα), an intrinsically disordered protein, also interacts with the Kelch domain of Keap1 and mediates the import of Keap1 into the nucleus …


Experimental And Natural Warming Elevates Mercury Concentrations In Estuarine Fish, Jennifer A. Dijkstra, Kate L. Buckman, Darren Ward, David W. Evans, Michele Dionne, Celia Y. Chen Mar 2013

Experimental And Natural Warming Elevates Mercury Concentrations In Estuarine Fish, Jennifer A. Dijkstra, Kate L. Buckman, Darren Ward, David W. Evans, Michele Dionne, Celia Y. Chen

Dartmouth Scholarship

Marine food webs are the most important link between the global contaminant, methylmercury (MeHg), and human exposure through consumption of seafood. Warming temperatures may increase human exposure to MeHg, a potent neurotoxin, by increasing MeHg production as well as bioaccumulation and trophic transfer through marine food webs. Studies of the effects of temperature on MeHg bioaccumulation are rare and no study has specifically related temperature to MeHg fate by linking laboratory experiments with natural field manipulations in coastal ecosystems. We performed laboratory and field experiments on MeHg accumulation under varying temperature regimes using the killifish, Fundulus heteroclitus. Temperature treatments …


Detection And Quantification Of Methylation In Dna Using Solid-State Nanopores., Jiwook Shim, Gwendolyn I Humphreys, Bala Murali Venkatesan, Jan Marie Munz, Xueqing Zou, Chaitanya Sathe, Klaus Schulten, Farhad Kosari, Ann M Nardulli, George Vasmatzis, Rashid Bashir Mar 2013

Detection And Quantification Of Methylation In Dna Using Solid-State Nanopores., Jiwook Shim, Gwendolyn I Humphreys, Bala Murali Venkatesan, Jan Marie Munz, Xueqing Zou, Chaitanya Sathe, Klaus Schulten, Farhad Kosari, Ann M Nardulli, George Vasmatzis, Rashid Bashir

College of Science & Mathematics Departmental Research

Epigenetic modifications in eukaryotic genomes occur primarily in the form of 5-methylcytosine (5 mC). These modifications are heavily involved in transcriptional repression, gene regulation, development and the progression of diseases including cancer. We report a new single-molecule assay for the detection of DNA methylation using solid-state nanopores. Methylation is detected by selectively labeling methylation sites with MBD1 (MBD-1x) proteins, the complex inducing a 3 fold increase in ionic blockage current relative to unmethylated DNA. Furthermore, the discrimination of methylated and unmethylated DNA is demonstrated in the presence of only a single bound protein, thereby giving a resolution of a single …


Excitatory Amino Acids Display Compartmental Disparity Between Plasma And Synovial Fluid In Clinical Arthropathies, Terry A. Mcnearney, Karin N. Westlund Mar 2013

Excitatory Amino Acids Display Compartmental Disparity Between Plasma And Synovial Fluid In Clinical Arthropathies, Terry A. Mcnearney, Karin N. Westlund

Physiology Faculty Publications

BACKGROUND: Previous studies have demonstrated elevated levels of excitatory amino acids (EAA) glutamate (Glu) and aspartate (Asp) in the synovial fluid (SF) of patients with active arthritis. The source of SF EAA concentrations are thought in large part to be secondary to passive diffusion from the plasma across synovial membranes and less so, reflective of local synovial pathology.

OBJECTIVE: This descriptive report assesses the hypothesis that the SF EAA levels reflect inflammatory processes of the joint and are not dependent on plasma levels.

METHODS: Simultaneously drawn plasma and SF samples were obtained from 14 recently deceased cadavers and 10 patients …


Implicitly Priming The Social Brain: Failure To Find Neural Effects, Katherine E. Powers, Todd F. Heatherton Feb 2013

Implicitly Priming The Social Brain: Failure To Find Neural Effects, Katherine E. Powers, Todd F. Heatherton

Dartmouth Scholarship

Humans have a fundamental need for social relationships. Rejection from social groups is especially detrimental, rendering the ability to detect threats to social relationships and respond in adaptive ways critical. Indeed, previous research has shown that experiencing social rejection alters the processing of subsequent social cues in a variety of socially affiliative and avoidant ways. Because social perception and cognition occurs spontaneously and automatically, detecting threats to social relationships may occur without conscious awareness or control. Here, we investigated the automaticity of social threat detection by examining how implicit primes affect neural responses to social stimuli. However, despite using a …


Pyrvinium Pamoate Changes Alternative Splicing Of The Serotonin Receptor 2c By Influencing Its Rna Structure, Manli Shen, Stanislav Bellaousov, Michael Hiller, Pierre De La Grange, Trevor O. Creamer, Orit Malina, Ruth Sperling, David H. Mathews, Peter Stoilov, Stefan Stamm Feb 2013

Pyrvinium Pamoate Changes Alternative Splicing Of The Serotonin Receptor 2c By Influencing Its Rna Structure, Manli Shen, Stanislav Bellaousov, Michael Hiller, Pierre De La Grange, Trevor O. Creamer, Orit Malina, Ruth Sperling, David H. Mathews, Peter Stoilov, Stefan Stamm

Molecular and Cellular Biochemistry Faculty Publications

The serotonin receptor 2C plays a central role in mood and appetite control. It undergoes pre-mRNA editing as well as alternative splicing. The RNA editing suggests that the pre-mRNA forms a stable secondary structure in vivo. To identify substances that promote alternative exons inclusion, we set up a high-throughput screen and identified pyrvinium pamoate as a drug-promoting exon inclusion without editing. Circular dichroism spectroscopy indicates that pyrvinium pamoate binds directly to the pre-mRNA and changes its structure. SHAPE (selective 2'-hydroxyl acylation analysed by primer extension) assays show that part of the regulated 5'-splice site forms intramolecular base pairs that …


Honokiol Blocks Store Operated Calcium Entry In Cho Cells Expressing The M3 Muscarinic Receptor: Honokiol And Muscarinic Signaling, Hsiu-Jen Wang, Alexis Martin, Po-Kuan Chao, Rhett A. Reichard, Adam L. Martin, Yue-Wern Huang, Ming-Huan Chan, Robert Aronstam Feb 2013

Honokiol Blocks Store Operated Calcium Entry In Cho Cells Expressing The M3 Muscarinic Receptor: Honokiol And Muscarinic Signaling, Hsiu-Jen Wang, Alexis Martin, Po-Kuan Chao, Rhett A. Reichard, Adam L. Martin, Yue-Wern Huang, Ming-Huan Chan, Robert Aronstam

Biological Sciences Faculty Research & Creative Works

Background: Honokiol, a cell-permeable phenolic compound derived from the bark of magnolia trees and present in Asian herbal teas, has a unique array of pharmacological actions, including the inhibition of multiple autonomic responses. We determined the effects of honokiol on calcium signaling underlying transmission mediated by human M3 muscarinic receptors expressed in Chinese hamster ovary (CHO) cells. Receptor binding was determined in radiolabelled ligand binding assays; changes in intracellular calcium concentrations were determined using a fura-2 ratiometric imaging protocol; cytotoxicity was determined using a dye reduction assay.

Results: Honokiol had a potent (EC50 ≈ 5 μmol/l) inhibitory effect on store …


Tree Climbing And Human Evolution, Vivek V. Venkataraman, Thomas S. Kraft, Nathaniel J. Dominy Jan 2013

Tree Climbing And Human Evolution, Vivek V. Venkataraman, Thomas S. Kraft, Nathaniel J. Dominy

Dartmouth Scholarship

Paleoanthropologists have long argued—often contentiously—about the climbing abilities of early hominins and whether a foot adapted to terrestrial bipedalism constrained regular access to trees. However, some modern humans climb tall trees routinely in pursuit of honey, fruit, and game, often without the aid of tools or support systems. Mortality and morbidity associated with facultative arboreality is expected to favor behaviors and anatomies that facilitate safe and efficient climbing. Here we show that Twa hunter–gatherers use extraordinary ankle dorsiflexion (>45°) during climbing, similar to the degree observed in wild chimpanzees. Although we did not detect a skeletal signature of dorsiflexion …


Community Outreach And Engagement To Prepare For Household Recruitment Of National Children's Study Participants In A Rural Setting, Nancy L. Fahrenwald, Betty Wey, Ann Martin, Bonny L. Specker Jan 2013

Community Outreach And Engagement To Prepare For Household Recruitment Of National Children's Study Participants In A Rural Setting, Nancy L. Fahrenwald, Betty Wey, Ann Martin, Bonny L. Specker

Ethel Austin Martin Program Publications

CONTEXT: The National Children's Study (NCS) is a longitudinal study of environmental influences on children's health. Recruitment of a representative birth cohort that will be followed until 21 years of age requires unique approaches across the nationwide study communities.
PURPOSE: To describe community outreach and engagement in preparation for household recruitment of women of childbearing age at a rural-classified NCS location that includes 4 adjacent Northern Plains counties spanning 2,500 square miles.
METHODS: Outreach and engagement methods focused on rural community characteristics. The team established an advisory council, conducted outreach meetings with agencies and groups, participated in local events, and …


An Independent Audit Of The Australian Food Industry's Voluntary Front-Of-Pack Nutrition Labelling Scheme For Energy-Dense Nutrition-Poor Foods, Owen B. Carter, Brennen W. Mills, Tina Phan, Elanie Lloyd Jan 2013

An Independent Audit Of The Australian Food Industry's Voluntary Front-Of-Pack Nutrition Labelling Scheme For Energy-Dense Nutrition-Poor Foods, Owen B. Carter, Brennen W. Mills, Tina Phan, Elanie Lloyd

Research outputs 2013

Background/Objective: Since 2006, the Australian food industry has promoted its front-of-pack (FOP) food labelling system-the Daily Intake Guide (DIG)-as a success story of industry self-regulation. With over 4000 products already voluntary featuring the DIG, the industry argues that government regulation of FOP nutrition labelling is simply unnecessary. However, no independent audit of the industry's self-regulation has ever been undertaken and we present the first such Australian data.

Subjects/Methods: Energy-dense nutrient-poor (EDNP) snacks were audited at nine Australian supermarkets, including biscuits, candy, ice creams, chocolates, crisps, sports drinks, energy drinks, flavoured milks, sweetened juices and soft drinks. In these categories nutrition …


Delivering Genetic Education And Genetic Counseling For Rare Diseases In Rural Brazil, A.X. Acosta, K Abe-Sandes, R Giugliani, Alan H. Bittles Jan 2013

Delivering Genetic Education And Genetic Counseling For Rare Diseases In Rural Brazil, A.X. Acosta, K Abe-Sandes, R Giugliani, Alan H. Bittles

Research outputs 2013

Brazil is the largest country in Latin America, with an ethnically diverse, Portuguese-speaking and predominantly Roman Catholic population of some 194 million. Universal health care is provided under the Federal Unified Health System (Sistema Único de Saúde) but, as in many other middle and low income countries, access to medical genetics services is limited in rural and remote regions of the country. Since there is no formally recognized Genetic Counseling profession, genetic counseling is provided by physicians, trained either in medical genetics or a related clinical discipline. A comprehensive medical genetics program has been established in Monte Santo, an inland …


Predicting Barriers To Primary Care For Patients With Disabilities: A Mixed Methods Study Of Practice Administrators, Jennifer Renee Pharr, Michelle Chino Jan 2013

Predicting Barriers To Primary Care For Patients With Disabilities: A Mixed Methods Study Of Practice Administrators, Jennifer Renee Pharr, Michelle Chino

Environmental & Global Health Faculty Research

Background. People with disabilities continue to be identified as a group who experience disparate health/health care. They are less likely to engage in some health care services. Structural barriers are often identified as one of the reasons for the underutilization of some health care services by people with disabilities. However, to date no study has been conducted to understand why structural barriers persist twenty years after the Americans with Disabilities Act (ADA) became law.

Objectives. We examined the relationship between primary care practice administrators’ knowledge of the ADA and the number of accessibility barriers that patients with mobility disabilities might …


Alginate Lyase Exhibits Catalysis-Independent Biofilm Dispersion And Antibiotic Synergy, John W. Lamppa, Karl E. Griswold Jan 2013

Alginate Lyase Exhibits Catalysis-Independent Biofilm Dispersion And Antibiotic Synergy, John W. Lamppa, Karl E. Griswold

Dartmouth Scholarship

More than 2 decades of study support the hypothesis that alginate lyases are promising therapeutic candidates for treating mucoid Pseudomonas aeruginosa infections. In particular, the enzymes' ability to degrade alginate, a key component of mucoid biofilm matrix, has been the presumed mechanism by which they disrupt biofilms and enhance antibiotic efficacy. The systematic studies reported here show that, in an in vitro model, alginate lyase dispersion of P. aeruginosa biofilms and enzyme synergy


Force Generation By Kinesin And Myosin Cytoskeletal Motor Proteins, F. Jon Kull, Sharyn A. Endow Jan 2013

Force Generation By Kinesin And Myosin Cytoskeletal Motor Proteins, F. Jon Kull, Sharyn A. Endow

Dartmouth Scholarship

Kinesins and myosins hydrolyze ATP, producing force that drives spindle assembly, vesicle transport and muscle contraction. How do motors do this? Here we discuss mechanisms of motor force transduction, based on their mechanochemical cycles and conformational changes observed in crystal structures. Distortion or twisting of the central β-sheet - proposed to trigger actin-induced Pi and ADP release by myosin, and microtubule-induced ADP release by kinesins - is shown in a movie depicting the transition between myosin ATP-like and nucleotide-free states. Structural changes in the switch I region form a tube that governs ATP hydrolysis and Pi release by the motors, …


A Physical Sciences Network Characterization Of Non-Tumorigenic And Metastatic Cells, Abigail Hielscher, D. Wirtz, Et Al. Jan 2013

A Physical Sciences Network Characterization Of Non-Tumorigenic And Metastatic Cells, Abigail Hielscher, D. Wirtz, Et Al.

PCOM Scholarly Works

To investigate the transition from non-cancerous to metastatic from a physical sciences perspective, the Physical Sciences-Oncology Centers (PS-OC) Network performed molecular and biophysical comparative studies of the non-tumorigenic MCF-10A and metastatic MDA-MB-231 breast epithelial cell lines, commonly used as models of cancer metastasis. Experiments were performed in 20 laboratories from 12 PS-OCs. Each laboratory was supplied with identical aliquots and common reagents and culture protocols. Analyses of these measurements revealed dramatic differences in their mechanics, migration, adhesion, oxygen response, and proteomic profiles. Model-based multi-omics approaches identified key differences between these cells' regulatory networks involved in morphology and survival. These results …


Identifying Requirements For The Invasion Of A Tick Species And Tick-Borne Pathogen Through Ticksim, Holly Gaff, Robyn Nadolny Jan 2013

Identifying Requirements For The Invasion Of A Tick Species And Tick-Borne Pathogen Through Ticksim, Holly Gaff, Robyn Nadolny

Biological Sciences Faculty Publications

Ticks and tick-borne diseases have been on the move throughout the United State over the past twenty years. We use an agent-based model, TICKSIM, to identify the key parameters that determine the success of invasion of the tick and if that is successful, the success of the tick-borne pathogen. We find that if an area has competent hosts, an initial population of ten ticks is predicted to always establish a new population. The establishment of the tick-borne pathogen depends on three parameters: the initial prevalence in the ten founding ticks, the probability that a tick infects the longer-lived hosts and …


Association Of Iron Depletion With Menstruation And Dietary Intake Indices In Pubertal Girls: The Healthy Growth Study, George Moschonis, Dimitrios Papandreou, Christina Mavrogianni, Angeliki Giannopoulou, Louisa Damianidi, Pavlos Malindretos, Christos Lionis, George P. Chrousos, Yannis Manios Jan 2013

Association Of Iron Depletion With Menstruation And Dietary Intake Indices In Pubertal Girls: The Healthy Growth Study, George Moschonis, Dimitrios Papandreou, Christina Mavrogianni, Angeliki Giannopoulou, Louisa Damianidi, Pavlos Malindretos, Christos Lionis, George P. Chrousos, Yannis Manios

All Works

The aim of the present study was to investigate the associations of iron depletion (ID) with menstrual blood losses, lifestyle, and dietary habits, in pubertal girls. The study sample comprised 1222 girls aged 9-13 years old. Biochemical, anthropometrical, dietary, clinical, and physical activity data were collected. Out of 274 adolescent girls with menses, 33.5% were found to be iron depleted (defined as serum ferritin < 12 g/L) compared to 15.9% out of 948 girls without menses. Iron-depleted girls without menses were found to have lower consumption of poultry (P = 0.017) and higher consumption of fruits (P = 0.044) and fast food (P = 0.041) compared to their peers having normal iron status. Multivariate logistic regression analysis showed that girls with menses were 2.57 (95% CI: 1.37, 4.81) times more likely of being iron depleted compared to girls with no menses. Iron depletion was found to be associated with high calcium intake, high consumption of fast foods, and low consumption of poultry and fruits. Menses was the only factor that was found to significantly increase the likelihood of ID in these girls. More future research is probably needed in order to better understand the role of diet and menses in iron depletion. © 2013 George Moschonis et al.


Vegf And Angiopoietin-1 Exert Opposing Effects On Cell Junctions By Regulating The Rho Gef Syx, Siu P. Ngok, Rory Geyer, Miaoliang Liu, Antonis Kourtidis, Sudesh Agrawal, Chuanshen Wu, Himabindu Reddy Seerapu, Laura J. Lewis-Tuffin, Karen L. Moodie, Deborah Huveldt, Ruth Marx, Jay M. Baraban, Peter Storz, Arie Horowitz, Panos Z. Anastasiadis Dec 2012

Vegf And Angiopoietin-1 Exert Opposing Effects On Cell Junctions By Regulating The Rho Gef Syx, Siu P. Ngok, Rory Geyer, Miaoliang Liu, Antonis Kourtidis, Sudesh Agrawal, Chuanshen Wu, Himabindu Reddy Seerapu, Laura J. Lewis-Tuffin, Karen L. Moodie, Deborah Huveldt, Ruth Marx, Jay M. Baraban, Peter Storz, Arie Horowitz, Panos Z. Anastasiadis

Dartmouth Scholarship

Vascular endothelial growth factor (VEGF) and Ang1 (Angiopoietin-1) have opposing effects on vascular permeability, but the molecular basis of these effects is not fully known. We report in this paper that VEGF and Ang1 regulate endothelial cell (EC) junctions by determining the localization of the RhoA-specific guanine nucleotide exchange factor Syx. Syx was recruited to junctions by members of the Crumbs polarity complex and promoted junction integrity by activating Diaphanous. VEGF caused translocation of Syx from cell junctions, promoting junction disassembly, whereas Ang1 maintained Syx at the junctions, inducing junction stabilization. The VEGF-induced translocation of Syx from EC junctions was …


Adenosine Deaminase Enhances The Immunogenicity Of Human Dendritic Cells From Healthy And Hiv-Infected Individuals, Víctor Casanova, Isaac Isaac Naval-Macabuhay, Marta Massanella, Marta Rodríguez-García Dec 2012

Adenosine Deaminase Enhances The Immunogenicity Of Human Dendritic Cells From Healthy And Hiv-Infected Individuals, Víctor Casanova, Isaac Isaac Naval-Macabuhay, Marta Massanella, Marta Rodríguez-García

Dartmouth Scholarship

ADA is an enzyme implicated in purine metabolism, and is critical to ensure normal immune function. Its congenital deficit leads to severe combined immunodeficiency (SCID). ADA binding to adenosine receptors on dendritic cell surface enables T-cell costimulation through CD26 crosslinking, which enhances T-cell activation and proliferation. Despite a large body of work on the actions of the ecto-enzyme ADA on T-cell activation, questions arise on whether ADA can also modulate dendritic cell maturation. To this end we investigated the effects of ADA on human monocyte derived dendritic cell biology. Our results show that both the enzymatic and non-enzymatic activities of …


A Hunter Virus That Targets Both Infected Cells And Hiv Free Virions: Implications For Therapy, Cody Greer, Gisela García-Ramos Dec 2012

A Hunter Virus That Targets Both Infected Cells And Hiv Free Virions: Implications For Therapy, Cody Greer, Gisela García-Ramos

Biology Faculty Publications

The design of 'hunter' viruses aimed at destroying human immunodeficiency virus (HIV) infected cells is an active area of research that has produced promising results in vitro. Hunters are designed to target exposed viral envelope proteins in the membranes of infected cells, but there is evidence that the hunter may also target envelope proteins of free HIV, inducing virus-virus fusion. In order to predict the effects of this fusion on therapy outcomes and determine whether fusion ability is advantageous for hunter virus design, we have constructed a model to account for the possibility of hunter-HIV fusion. The study was based …