Medicine and Health Sciences Commons^™

Sensitization Of Human Cancer Cells To Gemcitabine By The Chk1 Inhibitor Mk-8776: Cell Cycle Perturbation And Impact Of Administration Schedule In Vitro And In Vivo, Ryan Montano, Ruth Thompson, Injae Chung, Huagang Hou, Nadeem Khan, Alan Eastman

Dartmouth Scholarship

Chk1 inhibitors have emerged as promising anticancer therapeutic agents particularly when combined with antimetabolites such as gemcitabine, cytarabine or hydroxyurea. Here, we address the importance of appropriate drug scheduling when gemcitabine is combined with the Chk1 inhibitor MK-8776, and the mechanisms involved in the schedule dependence.

Divergent Antibody Subclass And Specificity Profiles But Not Protective Hla-B Alleles Are Associated With Variable Antibody Effector Function Among Hiv-1 Controllers, Jennifer I. Lai, Anna F. Licht, Anne-Sophie Dugast, Todd Suscovich, Ickwon Choi, Chris Bailey-Kellogg, Galit Alter, Margaret E. Ackerman

Dartmouth Scholarship

Understanding the coordination between humoral and cellular immune responses may be the key to developing protective vaccines, and because genetic studies of long-term HIV-1 nonprogressors have associated specific HLA-B alleles with spontaneous control of viral replication, this subject group presents an opportunity to investigate relationships between arms of the adaptive immune system. Given evidence suggesting that cellular immunity may play a role in viral suppression, we sought to determine whether and how the humoral immune response might vary among controllers. Significantly, Fc-mediated antibody effector functions have likewise been associated with durable viral control. In this study, we compared the effector …

Definition Of An Hla-Dpw2-Restricted Epitope On Ns3, Recognized By A Dengue Virus Serotype-Cross-Reactive Human Cd4+ Cd8- Cytotoxic T-Cell Clone, Ichiro Kurane, Li Chen Dai, Peter G. Livingston, Elaine Reed, Francis A. Ennis

Li Dai

We previously reported that the clone JK34 was cross-reactive for dengue virus types 1, 2, 3, and 4 and recognized NS3 (I. Kurane, M. A. Brinton, A. L. Samson, and F. A. Ennis, J. Virol. 65:1823-1828, 1991). In the present experiments, we defined the epitope at the amino acid level, with 93 15-mer overlapping peptides which cover the entire NS3. A peptide 4 which contains amino acids 251 to 265 of NS3 sensitized the autologous B lymphoblastoid cell line (LCL) to the lysis by JK34. The smallest peptide recognized by JK34 was a 10-mer peptide which contains amino acids 255 …

Mutation Of Human Immunodeficiency Virus Type 1 At Amino Acid 585 On Gp41 Results In Loss Of Killing By Cd8+ A24-Restricted Cytotoxic T Lymphocytes, Li Chen Dai, Kim West, Rebecca A. Littaua, Kazuo Takahashi, Francis A. Ennis

Li Dai

A human leukocyte antigen A24-restricted CD8+ cytotoxic T-cell clone specific for gp41 of human immunodeficiency virus type 1 was isolated from an infected individual. The epitope was localized to amino acids 584 to 591 (YLKDQQLL, NL43 env sequence) of gp41 by using a panel of recombinant vaccinia viruses that contain truncated env genes and synthetic peptides. The clone killed autologous B-lymphoblastoid cell lines pulsed with a synthetic peptide reflecting the sequence of the IIIB and MN strains. This clone, however, failed to kill target cells pulsed with the peptides that have a mutation from Lys to Arg or Gln at …

The Gating Charge Should Not Be Estimated By Fitting A Two-State Model To A Q-V Curve, Francisco Bezanilla, Carlos A. Villalba-Galea

School of Pharmacy Faculty Articles

The voltage dependence of charges in voltage-sensitive proteins, typically displayed as charge versus voltage (Q-V) curves, is often quantified by fitting it to a simple two-state Boltzmann function. This procedure overlooks the fact that the fitted parameters, including the total charge, may be incorrect if the charge is moving in multiple steps. We present here the derivation of a general formulation for Q-V curves from multistate sequential models, including the case of infinite number of states. We demonstrate that the commonly used method to estimate the charge per molecule using a simple Boltzmann fit is not only inadequate, but in …

X-Linked Mtmr8 Diversity And Evolutionary History Of Sub-Saharan Populations, Damian Labuda, Vania Yotova, Jean-François Lefebvre, Claudia Moreau, Gerd Utermann, Scott M. Williams

Dartmouth Scholarship

The genetic diversity within an 11 kb segment of the MTMR8 gene in a sample of 111 sub-Saharan and 49 non-African X chromosomes was investigated to assess the early evolutionary history of sub-Saharan Africans and the out-of-Africa expansion. The analyses revealed a complex genetic structure of the Africans that contributed to the emergence of modern humans. We observed partitioning of two thirds of old lineages among southern, west/central and east African populations indicating ancient population stratification predating the out of Africa migration. Age estimates of these lineages, older than coalescence times of uniparentally inherited markers, raise the question whether contemporary …

Recurrent Tissue-Specific Mtdna Mutations Are Common In Humans, David C. Samuels, Chun Li, Bingshan Li, Zhuo Song, Eric Torstenson, Hayley Boyd Clay, Antonis Rokas, Tricia A. Thornton-Wells, Jason H. Moore, Tia M. Hughes, Robert D. Hoffman, Jonathan L. Haines, Deborah G. Murdock, Douglas P. Mortlock, Scott M. Williams

Dartmouth Scholarship

Mitochondrial DNA (mtDNA) variation can affect phenotypic variation; therefore, knowing its distribution within and among individuals is of importance to understanding many human diseases. Intra-individual mtDNA variation (heteroplasmy) has been generally assumed to be random. We used massively parallel sequencing to assess heteroplasmy across ten tissues and demonstrate that in unrelated individuals there are tissue-specific, recurrent mutations. Certain tissues, notably kidney, liver and skeletal muscle, displayed the identical recurrent mutations that were undetectable in other tissues in the same individuals. Using RFLP analyses we validated one of the tissue-specific mutations in the two sequenced individuals and replicated the patterns in …

Sensing Charges Of The Ciona Intestinalis Voltage-Sensing Phosphatase, Carlos A. Villalba-Galea, Ludivine Frezza, Walter Sandtner, Francisco Bezanilla

School of Pharmacy Faculty Articles

Voltage control over enzymatic activity in voltage-sensitive phosphatases (VSPs) is conferred by a voltage-sensing domain (VSD) located in the N terminus. These VSDs are constituted by four putative transmembrane segments (S1 to S4) resembling those found in voltage-gated ion channels. The putative fourth segment (S4) of the VSD contains positive residues that likely function as voltage-sensing elements. To study in detail how these residues sense the plasma membrane potential, we have focused on five arginines in the S4 segment of the Ciona intestinalis VSP (Ci-VSP). After implementing a histidine scan, here we show that four arginine-to-histidine mutants, namely R223H to …

Epigenetic Dominance Of Prion Conformers, Eri Saijo, Hae-Eun Kang, Jifeng Bian, Kristi G. Bowling, Shawn Browning, Sehun Kim, Nora Hunter, Glenn C. Telling

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Although they share certain biological properties with nucleic acid based infectious agents, prions, the causative agents of invariably fatal, transmissible neurodegenerative disorders such as bovine spongiform encephalopathy, sheep scrapie, and human Creutzfeldt Jakob disease, propagate by conformational templating of host encoded proteins. Once thought to be unique to these diseases, this mechanism is now recognized as a ubiquitous means of information transfer in biological systems, including other protein misfolding disorders such as those causing Alzheimer's and Parkinson's diseases. To address the poorly understood mechanism by which host prion protein (PrP) primary structures interact with distinct prion conformations to influence pathogenesis, …

Killerflip: A Novel Lytic Peptide Specifically Inducing Cancer Cell Death, B Pennarun, G. Gaidos, O Bucur, A Tinari

Dartmouth Scholarship

One of the objectives in the development of effective cancer therapy is induction of tumor-selective cell death. Toward this end, we have identified a small peptide that, when introduced into cells via a TAT cell-delivery system, shows a remarkably potent cytoxicity in a variety of cancer cell lines and inhibits tumor growth in vivo, whereas sparing normal cells and tissues. This fusion peptide was named killer FLIP as its sequence was derived from the C-terminal domain of c-FLIP, an anti-apoptotic protein. Using structure activity analysis, we determined the minimal bioactive core of killerFLIP, namely killerFLIP-E. Structural analysis of cells using …

Speed Is Relative (Human And Animal Running Speeds): Are You A Cheetah, A Chicken, Or A Snail?, Chad E. Buckley

Faculty and Staff Publications – Milner Library

To put matters in perspective, running speeds for humans and other land animals are compared over various distances. Humans compare quite favorably over longer distances with many species. Both fast and slow human runners can benefit from comparing their individual times in races with other species.

A Population-Based Case–Control Study Of Urinary Arsenic Species And Squamous Cell Carcinoma In New Hampshire, Usa, Diane Gilbert-Diamond, Zhigang Li, Ann E. Perry, Steven K. Spencer, A Jay Gandolfi, Margaret R. Karagas

Dartmouth Scholarship

Background: Chronic high arsenic exposure is associated with squamous cell carcinoma (SCC) of the skin, and inorganic arsenic (iAs) metabolites may play an important role in this association. However, little is known about the carcinogenicity of arsenic at levels commonly observed in the United States.

Objective: We estimated associations between total urinary arsenic and arsenic species and SCC in a U.S. population.

Methods: We conducted a population-based case–control SCC study (470 cases, 447 controls) in a U.S. region with moderate arsenic exposure through private well water and diet. We measured urinary iAs, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA), and …

The Flexible Fairness: Equality, Earned Entitlement, And Self-Interest, Chunliang Feng, Yi Luo, Ruolei Gu, Lucas S. Broster, Xueyi Shen, Tengxiang Tian, Yue-Jia Luo, Frank Krueger

Behavioral Science Faculty Publications

The current study explored whether earned entitlement modulated the perception of fairness in three experiments. A preliminary resource earning task was added before players decided how to allocate the resource they jointly earned. Participants' decision in allocation, their responses to equal or unequal offers, whether advantageous or disadvantageous, and subjective ratings of fairness were all assessed in the current study. Behavioral results revealed that participants proposed more generous offers and showed enhanced tolerance to disadvantageous unequal offers from others when they performed worse than their presumed "partners," while the reverse was true in the better-performance condition. The subjective ratings also …

Aspirin And Low-Molecular Weight Heparin Combination Therapy Effectively Prevents Recurrent Miscarriage In Hyperhomocysteinemic Women., Pratip Chakraborty, Sayani Banerjee, Piyali Saha, Shyam Sundar Nandi, Sunita Sharma, Sourendra K. Goswami, Baidyanath Chakravarty, Syed N. Kabir

Journal Articles: Cellular & Integrative Physiology

The management of recurrent pregnancy loss (RPL) still remains a great challenge, and women with polycystic ovarian syndrome (PCOS) are at a greater risk for spontaneous abortion. Treatment with low-molecular-weight heparin (LMWH) has become an accepted treatment option for women with RPL; however, the subgroup of women, who are likely to respond to LMWH, has not been precisely identified. The present study evaluated the efficacy of LMWH with reference to PCOS and associated metabolic phenotypes including hyperhomocysteinemia (HHcy), insulin resistance (IR) and obesity. This prospective observational study was conducted at Institute of Reproductive Medicine, Kolkata, India. A total of 967 …

Bioengineered Lysozyme Reduces Bacterial Burden And Inflammation In A Murine Model Of Mucoid Pseudomonas Aeruginosa Lung Infection, Charlotte C. Teneback, Thomas C. Scanlon, Matthew J. Wargo, Jenna L. Bement, Karl E. Griswold, Laurie W. Leclair

Dartmouth Scholarship

The spread of drug-resistant bacterial pathogens is a growing global concern and has prompted an effort to explore potential adjuvant and alternative therapies derived from nature's repertoire of bactericidal proteins and peptides. In humans, the airway surface liquid layer is a rich source of antibiotics, and lysozyme represents one of the most abundant and effective antimicrobial components of airway secretions. Human lysozyme is active against both Gram-positive and Gram-negative bacteria, ac

Treatment With Monoclonal Antibodies Against Clostridium Difficile Toxins, Israel Lowy, Deborah Molrine, Brett Leav, Barbara Blair, Roger Baxter, Dale Gerding, Geoffrey Nichol, William Thomas, Mark Leney, Susan Sloan, Catherine Hay, Donna Ambrosino

William D Thomas Jr

BACKGROUND: New therapies are needed to manage the increasing incidence, severity, and high rate of recurrence of Clostridium difficile infection.

METHODS: We performed a randomized, double-blind, placebo-controlled study of two neutralizing, fully human monoclonal antibodies against C. difficile toxins A (CDA1) and B (CDB1). The antibodies were administered together as a single infusion, each at a dose of 10 mg per kilogram of body weight, in patients with symptomatic C. difficile infection who were receiving either metronidazole or vancomycin. The primary outcome was laboratory-documented recurrence of infection during the 84 days after the administration of monoclonal antibodies or placebo.

RESULTS: …

Human Monoclonal Antibodies Directed Against Toxins A And B Prevent Clostridium Difficile-Induced Mortality In Hamsters, Gregory Babcock, Teresa Broering, Hector Hernandez, Robert Mandell, Katherine Donahue, Naomi Boatright, Anne Stack, Israel Lowy, Robert Graziano, Deborah Molrine, Donna Ambrosino, William Thomas

William D Thomas Jr

Clostridium difficile is the leading cause of nosocomial antibiotic-associated diarrhea, and recent outbreaks of strains with increased virulence underscore the importance of identifying novel approaches to treat and prevent relapse of Clostridium difficile-associated diarrhea (CDAD). CDAD pathology is induced by two exotoxins, toxin A and toxin B, which have been shown to be cytotoxic and, in the case of toxin A, enterotoxic. In this report we describe fully human monoclonal antibodies (HuMAbs) that neutralize these toxins and prevent disease in hamsters. Transgenic mice carrying human immunoglobulin genes were used to isolate HuMAbs that neutralize the cytotoxic effects of either toxin …

Amino Acids 270 To 510 Of The Severe Acute Respiratory Syndrome Coronavirus Spike Protein Are Required For Interaction With Receptor, Gregory Babcock, Diana Esshaki, William Thomas, Donna Ambrosino

William D Thomas Jr

A novel coronavirus, severe acute respiratory syndrome coronavirus (SARS-CoV), has recently been identified as the causative agent of severe acute respiratory syndrome (SARS). SARS-CoV appears similar to other coronaviruses in both virion structure and genome organization. It is known for other coronaviruses that the spike (S) glycoprotein is required for both viral attachment to permissive cells and for fusion of the viral envelope with the host cell membrane. Here we describe the construction and expression of a soluble codon-optimized SARS-CoV S glycoprotein comprising the first 1,190 amino acids of the native S glycoprotein (S(1190)). The codon-optimized and native S glycoproteins …

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 …

Structural And Thermodynamic Basis Of Amprenavir/Darunavir And Atazanavir Resistance In Hiv-1 Protease With Mutations At Residue 50, Seema Mittal, Rajintha Bandaranayake, Nancy King, Moses Prabu-Jeyabalan, Madhavi Nalam, Ellen Nalivaika, Nese Yilmaz, Celia Schiffer

Celia A. Schiffer

Drug resistance occurs through a series of subtle changes that maintain substrate recognition but no longer permit inhibitor binding. In HIV-1 protease, mutations at I50 are associated with such subtle changes that confer differential resistance to specific inhibitors. Residue I50 is located at the protease flap tips, closing the active site upon ligand binding. Under selective drug pressure, I50V/L substitutions emerge in patients, compromising drug susceptibility and leading to treatment failure. The I50V substitution is often associated with amprenavir (APV) and darunavir (DRV) resistance, while the I50L substitution is observed in patients failing atazanavir (ATV) therapy. To explain how APV, …

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 …

Initial Multicenter Experience With Double Nucleoside Therapy For Human Immunodeficiency Virus Infection During Pregnancy, Neal S. Silverman, D. Heather Watts, Joseph Hitti, D. M. Money, E. Livingston, J. Axelrod, J. M. Ernest, Douglas Robbins, M. M. Divito

Neal Silverman

OBJECTIVE: To study maternal and neonatal effects of combination nucleoside analog therapy administered to human immunodeficiency virus (HIV)-infected pregnant women for maternal indications. METHODS: A multicenter, prospective observational study was undertaken at six perinatal centers in the United States and Canada that supported regional referral programs for the treatment of HIV-infected pregnant women. Demographic, laboratory, and pregnancy outcome data were collected for 39 women whose antiretroviral treatment regimens were expanded to include more than one nucleoside analog for maternal indications. The 40 newborns were monitored at pediatric referral centers through at least three months of age to ascertain their HIV …

Decoupling Of Stretch Reflex And Background Muscle Activity During Anticipatory Postural Adjustments In Humans, Siddharth Vedula, Robert Kearney, Ross Wagner, Paul Stapley

Dr Paul J Stapley

We studied the evolution of stretch reXexes in relation to background electromyographic (EMG) activity in the soleus muscle preceding the onset of voluntary arm raise movements. Our objective was to investigate if changes in reXex EMG and muscle activity occur simultaneously and are similarly scaled in amplitude. Ten human subjects stood with each foot on pedals able to exert short dorsiXexor pulses during stance. Subjects were asked to product consistent voluntary arm raise movements to a target upon a visual cue. In ¼ of trials, no pulse perturbations were given, but in the remaining ¾’s of all trials pulses were …

Independent Control Of Limb Force Underlies Stability During Voluntary Head Movements In Standing Humans, Paul Stapley, Alicia Hilderley, Julia Leonard

Dr Paul J Stapley

Postural stability during voluntary head movements is maintained through the integration of vestibular and neck afferent inputs. These inputs combine to accurately estimate trunk position in space, relative to a turning head. In animals, a loss of vestibular information leads to an active destabilization of balance as neck afferent information is interpreted as a movement of the trunk under a stable head (Stapley et al. 2006).

Postural Adjustments For Online Corrections Of Arm Movements In Standing Humans, Julia Leonard, Valeriya Gritsenko, Ryan Ouckama, Paul Stapley

Dr Paul J Stapley

The aim of this study was to investigate how humans correct ongoing arm movements while standing. Specifically, we sought to understand whether the postural adjustments in the legs required for online corrections of arm movements are predictive or rely on feedback from the moving limb. To answer this question we measured online corrections in arm and leg muscles during pointing movements while standing. Nine health right-handed subjects reached with their dominant arm to a visual target in front of them and aligned with their midline. In some trials, the position of the target would switch from the central target to …

Reflex Changes Associated With Anticipatory Postural Adjustments Preceding Voluntary Arm Movements In Standing Humans, Siddharth Vedula, Paul J. Stapley, Robert E. Kearney

Dr Paul J Stapley

Dynamic changes in human stability, such as those induced by upper body movements, are preceded by anticipatory postural adjustments (APAs) in the rest of the body. We measured the excitability of the stretch reflex of the triceps-surae muscle group during APAs associated with unilateral right arm raises in standing humans. Our results demonstrate that reflex excitability and underlying muscle activity are linked during the APA period, but that they differ in their relative timing. This supports the idea that reflexes are controlled independently of muscle activation.

External Validity: We Need To Do More, Russell Glasgow, Lawrence Green, Lisa Klesges, David Abrams, Edwin Fisher, Michael Goldstein, Laura Hayman, Judith Ockene, C. Orleans

Laura L. Hayman

The article discusses the implications of two health research trends for improving the design, review and reporting of research and evaluation studies in the U.S. The first trend is the gap between research findings and application in practice. The other trend is the increased emphasis on the methodological quality of health research reports.

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 …

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 …