Digital Commons Network^™

Tract-Based Spatial Statistics In Preterm-Born Neonates Predicts Cognitive And Motor Outcomes At 18 Months., E G Duerden, J Foong, V Chau, H Branson, K J Poskitt, R E Grunau, A Synnes, J G Zwicker, S P Miller

Brain and Mind Institute Researchers' Publications

BACKGROUND AND PURPOSE: Adverse neurodevelopmental outcome is common in children born preterm. Early sensitive predictors of neurodevelopmental outcome such as MR imaging are needed. Tract-based spatial statistics, a diffusion MR imaging analysis method, performed at term-equivalent age (40 weeks) is a promising predictor of neurodevelopmental outcomes in children born very preterm. We sought to determine the association of tract-based spatial statistics findings before term-equivalent age with neurodevelopmental outcome at 18-months corrected age.

MATERIALS AND METHODS: Of 180 neonates (born at 24-32-weeks' gestation) enrolled, 153 had DTI acquired early at 32 weeks' postmenstrual age and 105 had DTI acquired later at …

Transient Visual Responses Reset The Phase Of Low-Frequency Oscillations In The Skeletomotor Periphery., Daniel K Wood, Chao Gu, Brian D Corneil, Paul L Gribble, Melvyn A Goodale

Brain and Mind Institute Researchers' Publications

We recorded muscle activity from an upper limb muscle while human subjects reached towards peripheral targets. We tested the hypothesis that the transient visual response sweeps not only through the central nervous system, but also through the peripheral nervous system. Like the transient visual response in the central nervous system, stimulus-locked muscle responses (< 100 ms) were sensitive to stimulus contrast, and were temporally and spatially dissociable from voluntary orienting activity. Also, the arrival of visual responses reduced the variability of muscle activity by resetting the phase of ongoing low-frequency oscillations. This latter finding critically extends the emerging evidence that the feedforward visual sweep reduces neural variability via phase resetting. We conclude that, when sensory information is relevant to a particular effector, detailed information about the sensorimotor transformation, even from the earliest stages, is found in the peripheral nervous system.

Correlation Of High Body Mass Index With More Advanced Localized Prostate Cancer At Radical Prostatectomy Is Not Reflected In Psa Level And Psa Density But Is Seen In Psa Mass, Oleksandr N. Kryvenko, Jonathan I. Epstein, Frederick A. Meier, Nilesh S. Gupta, Mani Menon, Mireya Diaz-Insua

Pathology and Laboratory Medicine Articles

OBJECTIVES: Prostate cancer screening algorithms and preoperative nomograms do not include patients' body mass index (BMI). We evaluated outcomes at radical prostatectomy (RP) adjusted to BMI.

METHODS: Serum prostate-specific antigen (PSA) levels, PSA mass, PSA density (PSAD), and RP findings were analyzed with respect to BMI in 4,926 men who underwent RP between 2005 and 2014.

RESULTS: In total, 1,001 (20.3%) men were normal weight, 2,547 (51.7%) were overweight, and 1,378 (28%) were obese. Median PSA levels (ng/mL) were normal weight, 5.0; overweight, 5.1; and obese, 5.2 (P = .094). Median PSA mass increased with increasing BMI: 15.9 vs 17.4 …

Structure-Based Screen Identifies A Potent Small Molecule Inhibitor Of Stat5a/B With Therapeutic Potential For Prostate Cancer And Chronic Myeloid Leukemia., Zhiyong Liao, Lei Gu, Jenny Vergalli, Samanta A. Mariani, Marco De Dominici, Ravi K. Lokareddy, Ayush Dagvadorj, Puranik Purushottamachar, Peter A. Mccue, Edouard J. Trabulsi, Costas D. Lallas, Shilpa Gupta, Elyse Ellsworth, Shauna Blackmon, Adam Ertel, Paolo Fortina, Benjamin E. Leiby, Guanjun Xia, Hallgeir Rui, David T. Hoang, Leonard G Gomella, Gino Cingolani, Vincent Njar, Nagarajan Pattabiraman, Bruno Calabretta, Marja T. Nevalainen

Department of Cancer Biology Faculty Papers

Bypassing tyrosine kinases responsible for Stat5a/b phosphorylation would be advantageous for therapy development for Stat5a/b-regulated cancers. Here, we sought to identify small molecule inhibitors of Stat5a/b for lead optimization and therapy development for prostate cancer and Bcr-Abl-driven leukemias. In silico screening of chemical structure databases combined with medicinal chemistry was used for identification of a panel of small molecule inhibitors to block SH2 domain-mediated docking of Stat5a/b to the receptor-kinase complex and subsequent phosphorylation and dimerization. We tested the efficacy of the lead compound IST5-002 in experimental models and patient samples of two known Stat5a/b-driven cancers, prostate cancer and chronic …

Infusion Of Reconstituted High-Density Lipoprotein, Csl112, In Patients With Atherosclerosis: Safety And Pharmacokinetic Results From A Phase 2a Randomized Clinical Trial, Pierluigi Tricoci, Denise M. D'Andrea, Paul A. Gurbel, Zhenling Yao, Marina Cuchel, Brion Winston, Robert Schott, Robert Weiss, Michael A. Blazing, Louis Cannon, Alison L. Bailey, Dominick J. Angiolillo, Andreas Gille, Charles L. Shear, Samuel D. Wright, John H. Alexander

Gill Heart & Vascular Institute Faculty Publications

Background CSL112 is a new formulation of human apolipoprotein A‐I (apoA‐I) being developed to reduce cardiovascular events following acute coronary syndrome. This phase 2a, randomized, double‐blind, multicenter, dose‐ranging trial represents the first clinical investigation to assess the safety and pharmacokinetics/pharmacodynamics of a CSL112 infusion among patients with stable atherosclerotic disease.

Methods and Results Patients were randomized to single ascending doses of CSL112 (1.7, 3.4, or 6.8 g) or placebo, administered over a 2‐hour period. Primary safety assessments consisted of alanine aminotransferase or aspartate aminotransferase elevations >3× upper limits of normal and study drug–related adverse events. Pharmacokinetic/pharmacodynamic assessments included apoA‐I plasma …

Federally Qualified Health Centers’ Capacity And Readiness For Research Collaborations: Implications For Clinical-Academic-Community Partnerships, Heather M. Brandt, Vicki M. Young, Dayna A. Campbell, Seul Ki Choi, Jessica S. Seel, Daniela B. Friedman

Faculty Publications

BACKGROUND: Federally qualified health centers (FQHCs) provide a health care safety net for underserved populations and contribute unique expertise to research that could further enhance quality of patient care. The purpose of this research was to assess interest in, readiness to, and capacity for conducting research in FQHCs in South Carolina (SC). METHODS: A Web-based survey was administered to 20 FQHCs across SC. Fourteen representatives of FQHCs completed the 39-item survey that assessed research experience and interest, partnerships and funding, barriers and benefits to research participation, training and technical assistance needs, and research capacity. RESULTS: FQHCs are interested in conducting …

Pharmacodynamics Of Folic Acid Receptor Targeted Antiretroviral Nanotherapy In Hiv-1-Infected Humanized Mice., Pavan Puligujja, Mariluz Araínga, Prasanta Dash, Diana L. Palandri, R. Lee Mosley, Santhi Gorantla, Larisa Y Poluektova, Joellyn Mcmillan, Howard Gendelman

Journal Articles: Pharmacology & Experimental Neuroscience

Long-acting nanoformulated antiretroviral therapy (nanoART) can sustain plasma drug levels and improve its biodistribution. Cell targeted-nanoART can achieve this and bring drug efficiently to viral reservoirs. However, whether such improvements affect antiretroviral responses remains unknown. To these ends, we tested folic acid (FA)-linked poloxamer407-coated ritonavir-boosted atazanavir (FA-nanoATV/r) nanoparticles for their ability to affect chronic HIV-1 infection in humanized mice. Following three, 100mg/kg FA-nanoATV/r intramuscular injections administered every other week to infected animals, viral RNA was at or below the detection limit, cell-associated HIV-1p24 reduced and CD4+ T cell counts protected. The dosing regimen improved treatment outcomes more than two fold …

The Sea Lamprey Meiotic Map Improves Resolution Of Ancient Vertebrate Genome Duplications, Jeramiah James Smith, Melissa C. Keinath

Biology Faculty Publications

It is generally accepted that many genes present in vertebrate genomes owe their origin to two whole-genome duplications that occurred deep in the ancestry of the vertebrate lineage. However, details regarding the timing and outcome of these duplications are not well resolved. We present high-density meiotic and comparative genomic maps for the sea lamprey (Petromyzon marinus), a representative of an ancient lineage that diverged from all other vertebrates ~550 million years ago. Linkage analyses yielded a total of 95 linkage groups, similar to the estimated number of germline chromosomes (1n ~ 99), spanning a total of 5570.25 cM. …

Intracellular Listeria Monocytogenes Comprises A Minimal But Vital Fraction Of The Intestinal Burden Following Foodborne Infection, Grant S. Jones, Kate M. Bussell, Tanya Myers-Morales, Abigail M. Fieldhouse, Elsa N. Bou Ghanem, Sarah E. F. D'Orazio

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Listeria monocytogenes is a highly adaptive bacterium that replicates as a free-living saprophyte in the environment as well as a facultative intracellular pathogen that causes invasive foodborne infections. The intracellular life cycle of L. monocytogenes is considered to be its primary virulence determinant during mammalian infection; however, the proportion of L. monocytogenes that is intracellular in vivo has not been studied extensively. In this report, we demonstrate that the majority of wild-type (strain EGDe) and mouse-adapted (InlA^m-expressing) L. monocytogenes recovered from the mesenteric lymph nodes (MLN) was extracellular within the first few days after foodborne infection. In addition, …

Amphiphilic Tobramycin Analogues As Antibacterial And Antifungal Agents, Sanjib K. Shrestha, Marina Y. Fosso, Keith D. Green, Sylvie Garneau-Tsodikova

Pharmaceutical Sciences Faculty Publications

In this study, we investigated the in vitro antifungal activities, cytotoxicities, and membrane-disruptive actions of amphiphilic tobramycin (TOB) analogues. The antifungal activities were established by determination of MIC values and in time-kill studies. Cytotoxicity was evaluated in mammalian cell lines. The fungal membrane-disruptive action of these analogues was studied by using the membrane-impermeable dye propidium iodide. TOB analogues bearing a linear alkyl chain at their 6″-position in a thioether linkage exhibited chain length-dependent antifungal activities. Analogues with C₁₂ and C₁₄ chains showed promising antifungal activities against tested fungal strains, with MIC values ranging from 1.95 to 62.5 mg/liter …

J-Wave Syndromes: Brugada And Early Repolarization Syndromes., Charles Antzelevitch, Gan-Xin Yan

Department of Medicine Faculty Papers

A prominent J wave is encountered in a number of life-threatening cardiac arrhythmia syndromes, including the Brugada syndrome and early repolarization syndromes. Brugada syndrome and early repolarization syndromes differ with respect to the magnitude and lead location of abnormal J waves and are thought to represent a continuous spectrum of phenotypic expression termed J-wave syndromes. Despite two decades of intensive research, risk stratification and the approach to therapy of these 2 inherited cardiac arrhythmia syndromes are still undergoing rapid evolution. Our objective in this review is to provide an integrated synopsis of the clinical characteristics, risk stratifiers, and molecular, ionic, …

Sex And Race And/Or Ethnicity Differences In Patients Undergoing Radiofrequency Ablation For Barrett's Esophagus: Results From The U.S. Rfa Registry., Sarina Pasricha, Nan Li, William J. Bulsiewicz, Richard I. Rothstein, Anthony Infantolino, Atilla Ertan, Daniel S. Camara, Evan S. Dellon, George Triadafilopoulos, Charles J. Lightdale, Ryan D. Madanick, William D. Lyday, Raman V. Muthusamy, Bergein F. Overholt, Nicholas J. Shaheen

Department of Medicine Faculty Papers

BACKGROUND: Little is known about differences in Barrett's esophagus (BE) characteristics by sex and race and/or ethnicity or these differences in response to radiofrequency ablation (RFA).

OBJECTIVE: We compared disease-specific characteristics, treatment efficacy, and safety outcomes by sex and race and/or ethnicity in patients treated with RFA for BE.

DESIGN: The U.S. RFA patient registry is a multicenter collaboration reporting processes and outcomes of care for patients treated with RFA for BE.

PATIENTS: Patients enrolled with BE.

INTERVENTIONS: RFA.

MAIN OUTCOME MEASUREMENTS: We assessed safety (stricture, bleeding, perforation, hospitalization), efficacy (complete eradication of intestinal metaplasia [CEIM]), complete eradication of dysplasia, …

Age At Onset In Patients With Medically Refractory Temporal Lobe Epilepsy And Mesial Temporal Sclerosis: Impact On Clinical Manifestations And Postsurgical Outcome., Ali Akbar Asadi-Pooya, Michael R. Sperling

Department of Neurology Faculty Papers

PURPOSE: To evaluate the demographic and clinical manifestations and postsurgical outcome of childhood-onset mesial temporal sclerosis and temporal lobe epilepsy (MTS-TLE) and establishing the potential differences as compared to the patients with adult-onset MTS-TLE.

METHOD: In this retrospective study all patients with a clinical diagnosis of medically refractory TLE due to mesial temporal sclerosis, who underwent epilepsy surgery at Jefferson comprehensive epilepsy center, were recruited. Patients were prospectively registered in a database from 1986 through 2014. Postsurgical outcome was classified into two groups; seizure-free or relapsed. Clinical manifestations and outcome were compared between patients with childhood-onset MTS-TLE (i.e., age at …

Noncontact Diffuse Correlation Tomography Of Human Breast Tumor, Lian He, Yu Lin, Chong Huang, Daniel Irwin, Margaret M. Szabunio, Guoqiang Yu

Biomedical Engineering Faculty Publications

Our first step to adapt our recently developed noncontact diffuse correlation tomography (ncDCT) system for three-dimensional (3-D) imaging of blood flow distribution in human breast tumors is reported. A commercial 3-D camera was used to obtain breast surface geometry, which was then converted to a solid volume mesh. An ncDCT probe scanned over a region of interest on the mesh surface and the measured boundary data were combined with a finite element framework for 3-D image reconstruction of blood flow distribution. This technique was tested in computer simulations and in vivo human breasts with low-grade carcinoma. Results from computer simulations …

Census-Based Socioeconomic Indicators For Monitoring Injury Causes In The Usa: A Review, Nathaniel Bell, Amanda Arrington, Swann Arp Adams

Faculty Publications

BACKGROUND:

Unlike the UK or New Zealand, there is no standard set of census variables in the USA for characterising socioeconomic (SES, socioeconomic status) inequalities in health outcomes, including injury. We systematically reviewed existing US studies to identify conceptual and methodological strengths and limitations of current approaches to determine those most suitable for research and surveillance.

METHODS:

We searched seven electronic databases to identify census variables proposed in the peer-reviewed literature to monitor injury risk. Inclusion criteria were that numerator data were derived from hospital, trauma or vital statistics registries and that exposure variables included census SES constructs.

RESULTS:

From …

Scarnas Regulate Splicing And Vertebrate Heart Development., Prakash Patil, Nataliya Kibiryeva, Tamayo Uechi, Jennifer A. Marshall, James E. O'Brien, Michael Artman, Naoya Kenmochi, Douglas C. Bittel

Manuscripts, Articles, Book Chapters and Other Papers

Alternative splicing (AS) plays an important role in regulating mammalian heart development, but a link between misregulated splicing and congenital heart defects (CHDs) has not been shown. We reported that more than 50% of genes associated with heart development were alternatively spliced in the right ventricle (RV) of infants with tetralogy of Fallot (TOF). Moreover, there was a significant decrease in the level of 12 small cajal body-specific RNAs (scaRNAs) that direct the biochemical modification of specific nucleotides in spliceosomal RNAs. We sought to determine if scaRNA levels influence patterns of AS and heart development. We used primary cells derived …

Prevalence Of And Risk Factors For Intracranial Abnormalities In Unprovoked Seizures., Peter S. Dayan, Kathleen Lillis, Jonathan Bennett, Gregory P. Conners, Pam Bailey, James Callahan, Cigdem Akman, Neil Feldstein, Joshua Kriger, W Allen Hauser, Nathan Kuppermann

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND AND OBJECTIVES: Prospective data are lacking to determine which children might benefit from prompt neuroimaging after unprovoked seizures. We aimed to determine the prevalence of, and risk factors for, relevant intracranial abnormalities in children with first, unprovoked seizures.

METHODS: We conducted a 6-center prospective study in children aged >28 days to 18 years with seemingly unprovoked seizures. Emergency department (ED) clinicians documented clinical findings on a standardized form. Our main outcome was the presence of a clinically relevant intracranial abnormality on computed tomography (CT) or MRI, defined as those that might change management, either emergently, urgently, or nonurgently.

RESULTS: …

The Rise And Fall Of Poly(Adp-Ribose): An Enzymatic Perspective., John M. Pascal, Tom Ellenberger

Department of Biochemistry and Molecular Biology Faculty Papers

Human cells respond to DNA damage with an acute and transient burst in production of poly(ADP-ribose), a posttranslational modification that expedites damage repair and plays a pivotal role in cell fate decisions. Poly(ADP-ribose) polymerases (PARPs) and glycohydrolase (PARG) are the key set of enzymes that orchestrate the rise and fall in cellular levels of poly(ADP-ribose). In this perspective, we focus on recent structural and mechanistic insights into the enzymes involved in poly(ADP-ribose) production and turnover, and we highlight important questions that remain to be answered.

Association Between Arsenic Exposure From Drinking Water And Longitudinal Change In Blood Pressure Among Heals Cohort Participants, Jieying Jiang, Mengling Liu, Faruque Parvez, Binhuan Wang, Fen Wu, Mahbub Eunus, Sripal Bangalore, Jonathan D. Newman, Alauddin Ahmed, Tariqul Islam, Muhammed Rakibuz-Zaman, Rabiul Hasan, Golam Sarwar, Diane Levy, Vesna Slavkovich, Maria Argos, Molly Scannell Bryan, Shohreh F. Farzan, Richard B. Hayes, Joseph H. Graziano, Habibul Ahsan, Yu Chen

Dartmouth Scholarship

Background:

Cross-sectional studies have shown associations between arsenic exposure and prevalence of high blood pressure; however, studies examining the relationship of arsenic exposure with longitudinal changes in blood pressure are lacking.

Method:

We evaluated associations of arsenic exposure in relation to longitudinal change in blood pressure in 10,853 participants in the Health Effects of Arsenic Longitudinal Study (HEALS). Arsenic was measured in well water and in urine samples at baseline and in urine samples every 2 years after baseline. Mixed-effect models were used to estimate the association of baseline well and urinary creatinine-adjusted arsenic with annual change in blood pressure …

Modified Maze Procedure For Atrial Fibrillation As An Adjunct To Elective Cardiac Surgery: Predictors Of Mid-Term Recurrence And Echocardiographic Follow-Up, Claudia Loardi, Francesco Alamanni, Fabrizio Veglia, Claudia Galli, Alessandro Parolari, Marco Zanobini

The Texas Heart Institute Journal

The radiofrequency maze procedure achieves sinus rhythm in 45%–95% of patients treated for atrial fibrillation. This retrospective study evaluates mid-term results of the radiofrequency maze—performed concomitant to elective cardiac surgery—to determine sinus-rhythm predictive factors, and describes the evolution of patients' echocardiographic variables.

From 2003 through 2011, 247 patients (mean age, 64 ± 9.5 yr) with structural heart disease (79.3% mitral disease) and atrial fibrillation underwent a concomitant radiofrequency modified maze procedure. Patients were monitored by 24-hour Holter at 3, 6, 12, and 24 months, then annually. Eighty-four mitral-valve patients underwent regular echocardiographic follow-up. Univariate and multivariate analysis for risk factors …

Transcatheter Aortic Valve Replacement: A Physician-Patient's Story, Herbert L Fred

The Texas Heart Institute Journal

No abstract provided.

Primary Prevention Of Sudden Cardiac Death In Adults With Transposition Of The Great Arteries: A Review Of Implantable Cardioverter-Defibrillator Placement, Sandeep S Sodhi, Ari M Cedars

The Texas Heart Institute Journal

Transposition of the great arteries encompasses a set of structural congenital cardiac lesions that has in common ventriculoarterial discordance. Primarily because of advances in medical and surgical care, an increasing number of children born with this anomaly are surviving into adulthood. Depending upon the subtype of lesion or the particular corrective surgery that the patient might have undergone, this group of adult congenital heart disease patients constitutes a relatively new population with unique medical sequelae. Among the more common and difficult to manage are cardiac arrhythmias and other sequelae that can lead to sudden cardiac death. To date, the question …

Impact Of Insulin Resistance On Neointimal Tissue Proliferation After 2nd-Generation Drug-Eluting Stent Implantation, Takaaki Komatsu, Isao Yaguchi, Sachiko Komatsu, Shiro Nakahara, Sayuki Kobayashi, Yoshihiko Sakai, Isao Taguchi

The Texas Heart Institute Journal

Percutaneous coronary intervention is established as an effective treatment for patients with ischemic heart disease; in particular, drug-eluting stent implantation is known to suppress in-stent restenosis. Diabetes mellitus is an independent risk factor for restenosis, so reducing insulin resistance is being studied as a new treatment approach. In this prospective study, we sought to clarify the factors associated with in-stent restenosis after percutaneous coronary intervention, and we evaluated the homeostasis model assessment of insulin resistance (HOMA-IR) index as a predictor of restenosis.

We enrolled 136 consecutive patients who underwent elective percutaneous coronary intervention at our hospital from February 2010 through …

Successful Use Of Therapeutic Hypothermia In A Pregnant Patient, Kevin N Oguayo, Ola O Oyetayo, David Stewart, Steven M Costa, Richard O Jones

The Texas Heart Institute Journal

Out-of-hospital cardiac arrest is a leading cause of death in the United States. Pregnant women are not immune to cardiac arrest, and the treatment of such patients can be difficult. Pregnancy is a relative contraindication to the use of therapeutic hypothermia after cardiac arrest.

A 20-year-old woman who was 18 weeks pregnant had an out-of-hospital cardiac arrest. Upon her arrival at the emergency department, she was resuscitated and her circulation returned spontaneously, but her score on the Glasgow Coma Scale was 3. After adequate family discussion of the risks and benefits of therapeutic hypothermia, a decision was made to initiate …

Effects Of A Clinician Referral And Exercise Program For Men Who Have Completed Active Treatment For Prostate Cancer: A Multicenter Cluster Randomized Controlled Trial (Engage)., Patricia M. Livingston, Melinda J. Craike, Jo Salmon, Kerry S. Courneya, Cadeyrn J. Gaskin, Steve F. Fraser, Mohammadreza Mohebbi, Suzanne Broadbent, Mari Botti, Bridie Kent, Engage Uro-Oncology Clinicians' Group

School of Nursing and Midwifery

BACKGROUND: The purpose of this study was to determine the efficacy of a clinician referral and exercise program in improving exercise levels and quality of life for men with prostate cancer. METHODS: This was a multicenter cluster randomized controlled trial in Melbourne, Australia comprising 15 clinicians: 8 clinicians were randomized to refer eligible participants (n = 54) to a 12-week exercise program comprising 2 supervised gym sessions and 1 home-based session per week, and 7 clinicians were randomized to follow usual care (n = 93). The primary outcome was self-reported physical activity; the secondary outcomes were quality of life, anxiety, …

Numerical Chromosomal Instability Mediates Susceptibility To Radiation Treatment, Samuel F. Bakhoum, Lilian Kabeche, Matthew D. Wood, Christopher D. Laucius

Dartmouth Scholarship

The exquisite sensitivity of mitotic cancer cells to ionizing radiation (IR) underlies an important rationale for the widely used fractionated radiation therapy. However, the mechanism for this cell cycle-dependent vulnerability is unknown. Here we show that treatment with IR leads to mitotic chromosome segregation errors in vivo and long-lasting aneuploidy in tumour-derived cell lines. These mitotic errors generate an abundance of micronuclei that predispose chromosomes to subsequent catastrophic pulverization thereby independently amplifying radiation-induced genome damage. Experimentally suppressing whole-chromosome missegregation reduces downstream chromosomal defects and significantly increases the viability of irradiated mitotic cells. Further, orthotopically transplanted human glioblastoma tumours in which …

Samhd1 Is A Single-Stranded Nucleic Acid Binding Protein With No Active Site-Associated Nuclease Activity., Kyle J. Seamon, Zhiqiang Sun, Luda S. Shlyakhtenko, Yuri L. Lyubchenko, James T. Stivers

Journal Articles: Pharmaceutical Sciences

The HIV-1 restriction factor SAMHD1 is a tetrameric enzyme activated by guanine nucleotides with dNTP triphosphate hydrolase activity (dNTPase). In addition to this established activity, there have been a series of conflicting reports as to whether the enzyme also possesses single-stranded DNA and/or RNA 3'-5' exonuclease activity. SAMHD1 was purified using three chromatography steps, over which the DNase activity was largely separated from the dNTPase activity, but the RNase activity persisted. Surprisingly, we found that catalytic and nucleotide activator site mutants of SAMHD1 with no dNTPase activity retained the exonuclease activities. Thus, the exonuclease activity cannot be associated with any …

Targeted Dna Damage At Individual Telomeres Disrupts Their Integrity And Triggers Cell Death, Luxi Sun, Rong Tan, Jianquan Xu, Justin Laface, Ying Gao, Yanchun Xiao, Myriam Attar, Carola Neumann, Guo-Min Li, Bing Su, Yang Liu, Satoshi Nakajima, Arthur S. Levine, Li Lan

Markey Cancer Center Faculty Publications

Cellular DNA is organized into chromosomes and capped by a unique nucleoprotein structure, the telomere. Both oxidative stress and telomere shortening/dysfunction cause aging-related degenerative pathologies and increase cancer risk. However, a direct connection between oxidative damage to telomeric DNA, comprising <1% of the genome, and telomere dysfunction has not been established. By fusing the KillerRed chromophore with the telomere repeat binding factor 1, TRF1, we developed a novel approach to generate localized damage to telomere DNA and to monitor the real time damage response at the single telomere level. We found that DNA damage at long telomeres in U2OS cells is not repaired efficiently compared to DNA damage in non-telomeric regions of the same length in heterochromatin. Telomeric DNA damage shortens the average length of telomeres and leads to cell senescence in HeLa cells and cell death in HeLa, U2OS and IMR90 cells, when DNA damage at non-telomeric regions is undetectable. Telomere-specific damage induces chromosomal aberrations, including chromatid telomere loss and telomere associations, distinct from the damage induced by ionizing irradiation. Taken together, our results demonstrate that oxidative damage induces telomere dysfunction and underline the importance of maintaining telomere integrity upon oxidative damage.

Trustworthy Guidelines – Excellent; Customized Care Tools – Even Better, Glyn Elwyn, Casey Quinlan, Albert Mulley, Thomas Agoritsas, Per Olav Vandvik, Gordon Guyatt

Dartmouth Scholarship

Background:

The ability to do online searches for health information has led to concerns that patients find the results confusing and that they often lead to expectations for treatments that have little supportive evidence. At the same time, the science of summarizing research evidence has advanced to the point where it is increasingly possible to quantify treatment tradeoffs and to describe the balance between harms and benefits for individual patients.

Discussion:

Trustworthy clinical practice guidelines provide evidence-based recommendations to health care practitioners based on assessments of study-level averages. In an effort to customize the use of evidence and ensure that …

Inflammatory Muscle Diseases., Marinos Dalakas

Department of Medicine Faculty Papers

No abstract provided.