Digital Commons Network^™

Drinking-Water Arsenic Exposure Modulates Gene Expression In Human Lymphocytes From A U.S. Population, Angeline S. Andrew, David A. Jewell, Rebecca A. Mason, Michael L. Whitfield, Jason H. Moore, Margaret R. Karagas

Dartmouth Scholarship

Background:

Arsenic exposure impairs development and can lead to cancer, cardiovascular disease, and diabetes. The mechanism underlying these effects remains unknown. Primarily because of geologic sources of contamination, drinking-water arsenic levels are above the current recommended maximum contaminant level of 10 μg/L in the northeastern, western, and north central regions of the United States.

Objectives:

We investigated the effects of arsenic exposure, defined by internal biomarkers at levels relevant to the United States and similarly exposed populations, on gene expression.

Methods:

We conducted separate Affymetrix microarray-based genomewide analyses of expression patterns. Peripheral blood lymphocyte samples from 21 controls interviewed (1999–2002) …

Drug Metabolism In Human Brain: High Levels Of Cytochrome P4503a43 In Brain And Metabolism Of Anti-Anxiety Drug Alprazolam To Its Active Metabolite, Varsha Agarwal, Reddy P. Kommaddi, Khader Valli, Daniel Ryder, Thomas M. Hyde, Joel E. Kleinman, Henry W. Strobel, Vijayalakshmi Ravindranath

Faculty, Staff and Student Publications

Cytochrome P450 (P450) is a super-family of drug metabolizing enzymes. P450 enzymes have dual function; they can metabolize drugs to pharmacologically inactive metabolites facilitating their excretion or biotransform them to pharmacologically active metabolites which may have longer half-life than the parent drug. The variable pharmacological response to psychoactive drugs typically seen in population groups is often not accountable by considering dissimilarities in hepatic metabolism. Metabolism in brain specific nuclei may play a role in pharmacological modulation of drugs acting on the CNS and help explain some of the diverse response to these drugs seen in patient population. P450 enzymes are …

Retinal Pigment Epithelial Tears After Intravitreal Bevacizumab Injection For Exudative Age-Related Macular Degeneration., Sunir Garg, Roy Brod, David Kim, R Gary Lane, Joseph Maguire, David Fischer

Wills Eye Hospital Papers

PURPOSE: To determine the incidence of and the risk factors for the development of retinal pigment epithelial (RPE) tears after intravitreal bevacizumab (Avastin) injection for the treatment of exudative age-related macular degeneration (AMD).

METHODS: A retrospective, multicentre, consecutive interventional case series of all patients with subfoveal exudative AMD treated with intravitreal bevacizumab between August 2005 and April 2007. The main outcome measures were pre- and post-RPE tear visual acuity and choroidal neovascular membrane lesion types, incidence of tears and time from first injection until development of the tear.

RESULTS: A total of 920 eyes with exudative AMD were treated with …

The Effect Of Dexmedetomidine On The Mini-Cog Score And High-Mobility Group Box 1 Levels In Elderly Patients With Postoperative Neurocognitive Disorders Undergoing Orthopedic Surgery, Joan M Mastrobattista, Mark A Klebanoff, J Christopher Carey, John C Hauth, Cora A Macpherson, J Ernest, Margaret Cotroneo, Kenneth J Leveno, Ronald Wapner, Michael Varner, Jay D Iams, Atef Moawad, Baha M Sibai, Menachem Miodovnik, Mitchell Dombrowski, Mary J O'Sullivan, J Peter Vandorsten, Oded Langer

Faculty, Staff and Student Publications

Our objective was to determine the effect of body mass index (BMI) on response to bacterial vaginosis (BV) treatment. A secondary analysis was conducted of two multicenter trials of therapy for BV and TRICHOMONAS VAGINALIS. Gravida were screened for BV between 8 and 22 weeks and randomized between 16 and 23 weeks to metronidazole or placebo. Of 1497 gravida with asymptomatic BV and preconceptional BMI, 738 were randomized to metronidazole; BMI was divided into categories: < 25, 25 to 29.9, and > or = 30. Rates of BV persistence at follow-up were compared using the Mantel-Haenszel chi square. Multiple logistic regression was used to evaluate the effect …

Abstracts In High Profile Journals Often Fail To Report Harm, Enrique Bernal-Delgado, Elliot S. Fisher

Dartmouth Scholarship

To describe how frequently harm is reported in the abstract of high impact factor medical journals. We carried out a blinded structured review of a random sample of 363 Randomised Controlled Trials (RCTs) carried out on human beings, and published in high impact factor medical journals in 2003. Main endpoint: 1) Proportion of articles reporting harm in the abstract; and 2) Proportion of articles that reported harm in the abstract when harm was reported in the main body of the article. Analysis: Corrected Prevalence Ratio (cPR) and its exact confidence interval were calculated. Non-conditional logistic regression was used.

The Acute Effects Of Elevated Blood Lipid Levels On Endothelial Function, Alexander Nissen

Yale Medicine Thesis Digital Library

The association between prolonged elevation of blood lipid levels and coronary artery disease is well established. Research focusing on the acute effects of hyperlipidemia is not as abundant, and often looks only at large-sized arteries. The purpose of our study was to measure the acute effects of elevated blood lipid levels on microvascular endothelial function, non-invasively, by means of laser Doppler flowmetry and the administration of vasoactive challenges. With IRB approval, six healthy subjects were recruited for a three-session study in which they were given isocaloric meals with variable fat content (non-fat meal = NM; fatty meal = FM; or …

The Use And Safety Of Vascular Occlusion Techniques: A Survey Of Practicing Surgeons, Ryan Kelly

Yale Medicine Thesis Digital Library

Vascular occlusion techniques can be divided into two categories ¡V transfixion and non-transfixion. Transfixion techniques are defined by the passage of suture material or staples through the vascular tissue. Non-transfixion techniques are defined as suture, metal, or polymer material placed solely around the vascular tissue. The purpose of this study was to survey surgeons in various specialties to determine which vascular control technique they believe is safest and most appropriate to manage medium-sized arteries 6-10mm in diameter. A survey was distributed to surgeons in the following specialties: general surgery, urology, thoracic surgery, vascular surgery, obstetrics and gynecology, and colon and …

Functional Imaging Of The Auditory Processing Applied To Speech Sounds, Roy D Patterson, Ingrid Johnsrude

Brain and Mind Institute Researchers' Publications

In this paper, we describe domain-general auditory processes that we believe are prerequisite to the linguistic analysis of speech. We discuss biological evidence for these processes and how they might relate to processes that are specific to human speech and language. We begin with a brief review of (i) the anatomy of the auditory system and (ii) the essential properties of speech sounds. Section 4 describes the general auditory mechanisms that we believe are applied to all communication sounds, and how functional neuroimaging is being used to map the brain networks associated with domain-general auditory processing. Section 5 discusses recent …

A Technological Approach To Reaching A Hidden Population Of Problem Drinkers., Daniel Z Lieberman, Suena W Huang

Psychiatry and Behavioral Sciences Faculty Publications

OBJECTIVE: The most common obstacle to the treatment of individuals with drinking problems is that most do not seek treatment. This study compared a group of treatment-seeking patients with users of an alcohol-evaluation Web site to determine whether an Internet application could reach a population of problem drinkers who are distinct from those served by currently available forms of care.

METHODS: An open-source application was developed that was modeled on the Drinker's Check-Up, which has been shown to increase motivation for behavior change while presenting itself as a nonthreatening evaluation. To recruit non-treatment seekers, the program was offered as a …

Clinical And Microbiological Aspects Of Linezolid Resistance Mediated By The Cfr Gene Encoding A 23s Rrna Methyltransferase, Cesar A Arias, Martha Vallejo, Jinnethe Reyes, Diana Panesso, Jaime Moreno, Elizabeth Castañeda, Maria V Villegas, Barbara E Murray, John P Quinn

Faculty, Staff and Student Publications

The cfr (chloramphenicol-florfenicol resistance) gene encodes a 23S rRNA methyltransferase that confers resistance to linezolid. Detection of linezolid resistance was evaluated in the first cfr-carrying human hospital isolate of linezolid and methicillin-resistant Staphylococcus aureus (designated MRSA CM-05) by dilution and diffusion methods (including Etest). The presence of cfr was investigated in isolates of staphylococci colonizing the patient's household contacts and clinical isolates recovered from patients in the same unit where MRSA CM-05 was isolated. Additionally, 68 chloramphenicol-resistant Colombian MRSA isolates recovered from hospitals between 2001 and 2004 were screened for the presence of the cfr gene. In addition to erm(B), …

Computational Models Of Tandem Src Homology 2 Domain Interactions And Application To Phosphoinositide 3-Kinase, Dipak Barua, James R. Faeder, Jason M. Haugh

Chemical and Biochemical Engineering Faculty Research & Creative Works

Intracellular signal transduction proteins typically utilize multiple interaction domains for proper targeting, and thus a broad diversity of distinct signaling complexes may be assembled. Considering the coordination of only two such domains, as in tandem Src homology 2 (SH2) domain constructs, gives rise to a kinetic scheme that is not adequately described by simple models used routinely to interpret in vitro binding measurements. To analyze the interactions between tandem SH2 domains and bisphosphorylated peptides, we formulated detailed kinetic models and applied them to the phosphoinositide 3-kinase p85 regulatory subunit/platelet-derived growth factor β-receptor system. Data for this system from different in …

The Management Of Keloids: Hands-On Versus Hands-Off., James Studdiford, Amber Stonehouse, Marc Altshuler, Elliot Rinzler

Department of Family & Community Medicine Faculty Papers

Keloids are benign fibrous growths that appear in scar tissue. The lesions can be severely disfiguring and early recognition of genetic lesions is crucial. This case report outlines and reviews the important management strategies for these lesions and the requirement for extensive counseling for the patient and their family. Many potential medical and surgical interventions exist. Unfortunately, these lesions tend to recur and overall outcomes remain poor. Given patient susceptibility to disfiguring results, surgical intervention should be used with extreme caution.

Verb Generation In Children With Spina Bifida, Maureen Dennis, Derryn Jewell, Ross Hetherington, Christine Burton, Michael E. Brandt, Susan E. Blaser, Jack M Fletcher

Faculty, Staff and Student Publications

We investigated verb generation in children with spina bifida meningomyelocele (SBM; n = 55) and in typically developing controls (n = 32). Participants completed 6 blocks (40 trials each) of a task requiring them to produce a semantically related verb in response to a target noun and an additional 40 trials on which they were simply required to read target nouns aloud. After controlling for reading response time, groups did not differ significantly in verb generation response time or learning. Children with SBM produced more non-verb errors than controls and tended to repeat their mistakes over blocks. Verb generation performance …

Activation Of Heat Shock And Antioxidant Responses By The Natural Product Celastrol: Transcriptional Signatures Of A Thiol-Targeted Molecule, Amy Trott, James D West, Lada Klaić, Sandy D Westerheide, Richard B Silverman, Richard I Morimoto, Kevin A Morano

Faculty, Staff and Student Publications

Stress response pathways allow cells to sense and respond to environmental changes and adverse pathophysiological states. Pharmacological modulation of cellular stress pathways has implications in the treatment of human diseases, including neurodegenerative disorders, cardiovascular disease, and cancer. The quinone methide triterpene celastrol, derived from a traditional Chinese medicinal herb, has numerous pharmacological properties, and it is a potent activator of the mammalian heat shock transcription factor HSF1. However, its mode of action and spectrum of cellular targets are poorly understood. We show here that celastrol activates Hsf1 in Saccharomyces cerevisiae at a similar effective concentration seen in mammalian cells. Transcriptional …

Using Built Environment Characteristics To Predict Walking For Exercise, Gina S. Lovasi, Anne V. Moudon, Amber L. Pearson, Philip M. Hurvitz, Eric B. Larson, David S. Siscovick, Ethan M. Berke

Dartmouth Scholarship

Environments conducive to walking may help people avoid sedentary lifestyles and associated diseases. Recent studies developed walkability models combining several built environment characteristics to optimally predict walking. Developing and testing such models with the same data could lead to overestimating one's ability to predict walking in an independent sample of the population. More accurate estimates of model fit can be obtained by splitting a single study population into training and validation sets (holdout approach) or through developing and evaluating models in different populations. We used these two approaches to test whether built environment characteristics near the home predict walking for …

Application Of Prodrugs To Inflammatory Diseases Of The Gut, Helieh S. Oz, Jeffrey L. Ebersole

Center for Oral Health Research Faculty Publications

Oral delivery is the most common and preferred route of drug administration although the digestive tract exhibits several obstacles to drug delivery including motility and intraluminal pH profiles. The gut milieu represents the largest mucosal surface exposed to microorganisms with 10^10-12 colony forming bacteria/g of colonic content. Approximately, one third of fecal dry matter is made of bacteria/ bacterial components. Indeed, the normal gut microbiota is responsible for healthy digestion of dietary fibers (polysaccharides) and fermentation of short chain fatty acids such as acetate and butyrate that provide carbon sources (fuel) for these bacteria. Inflammatory bowel disease (IBD) results …

Surgical Versus Nonsurgical Therapy For Lumbar Spinal Stenosis., James N Weinstein, Tor D Tosteson, Jon D Lurie, Anna N A Tosteson, Emily Blood, Brett Hanscom, Harry Herkowitz, Frank Cammisa, Todd Albert, Scott D Boden, Alan Hilibrand, Harley Goldberg, Sigurd Berven, Howard An

Rothman Institute Papers

BACKGROUND: Surgery for spinal stenosis is widely performed, but its effectiveness as compared with nonsurgical treatment has not been shown in controlled trials.

METHODS: Surgical candidates with a history of at least 12 weeks of symptoms and spinal stenosis without spondylolisthesis (as confirmed on imaging) were enrolled in either a randomized cohort or an observational cohort at 13 U.S. spine clinics. Treatment was decompressive surgery or usual nonsurgical care. The primary outcomes were measures of bodily pain and physical function on the Medical Outcomes Study 36-item Short-Form General Health Survey (SF-36) and the modified Oswestry Disability Index at 6 weeks, …

Surgical Versus Nonsurgical Therapy For Lumbar Spinal Stenosis., James N Weinstein, Tor D Tosteson, Jon D Lurie, Anna N A Tosteson, Emily Blood, Brett Hanscom, Harry Herkowitz, Frank Cammisa, Todd J Albert, Scott D Boden, Alan Hilibrand, Harley Goldberg, Sigurd Berven, Howard An

Rothman Institute Papers

BACKGROUND: Surgery for spinal stenosis is widely performed, but its effectiveness as compared with nonsurgical treatment has not been shown in controlled trials.

METHODS: Surgical candidates with a history of at least 12 weeks of symptoms and spinal stenosis without spondylolisthesis (as confirmed on imaging) were enrolled in either a randomized cohort or an observational cohort at 13 U.S. spine clinics. Treatment was decompressive surgery or usual nonsurgical care. The primary outcomes were measures of bodily pain and physical function on the Medical Outcomes Study 36-item Short-Form General Health Survey (SF-36) and the modified Oswestry Disability Index at 6 weeks, …

Sputum Microscopy For The Diagnosis Of Hiv-Associated Pulmonary Tuberculosis In Tanzania, Mecky Matee, Lillian Mtei, Tarja Lounasvaara, Wendy Wieland-Alter, Richard Waddell, Johnson Lyimo, Muhammed Bakari, Kisali Pallangyo, C Fordham Von Reyn

Dartmouth Scholarship

Background:

In many resource poor settings only sputum microscopy is employed for the diagnosis of HIV-associated pulmonary tuberculosis; sputum culture may not be available.

Methods:

We determined the diagnostic accuracy of sputum microscopy for active case finding of HIV-associated pulmonary tuberculosis using TB culture as the reference standard.

Results:

2216 potential subjects screened for a TB vaccine trial submitted 9454 expectorated sputum specimens: 212 (2.2%) were sputum culture positive for Mycobacterium tuberculosis (MTB), 31 (0.3%) for non-tuberculous mycobacteria, and 79 (0.8%) were contaminated. The overall sensitivity of sputum microscopy was 61.8% (131/212) and specificity 99.7% (9108/9132). Sputum microscopy sensitivity varied …

Sp1 Up-Regulates Camp-Response-Element-Binding Protein Expression During Retinoic Acid-Induced Mucous Differentiation Of Normal Human Bronchial Epithelial Cells, Jeong Soo Hong, Seung-Wook Kim, Ja Seok Koo

Faculty, Staff and Student Publications

CREB [CRE (cAMP-response element)-binding protein] is an important transcription factor that is differentially regulated in cells of various types. We recently reported that RA (retinoic acid) rapidly activates CREB without using RARs (RA receptors) or RXRs (retinoid X receptors) in NHTBE cells (normal human tracheobronchial epithelial cells). However, little is known about the role of RA in the physiological regulation of CREB expression in the early mucous differentiation of NHTBE cells. In the present study, we report that RA up-regulates CREB gene expression and that, using 5'-serial deletion promoter analysis and mutagenesis analyses, two Sp1 (specificity protein 1)-binding sites located …

Celecoxib Concentration Predicts Decrease In Prostaglandin E2 Concentrations In Nipple Aspirate Fluid From High Risk Women, Edward R. Sauter, Wenyi Qin, John E. Hewett, Rachel L. Ruhlen, John T. Flynn, George Rottinghaus, Yin-Chieh Chen

Department of Molecular Physiology and Biophysics Faculty Papers

BACKGROUND: Epidemiologic studies suggest that long term low dose celecoxib use significantly lowers breast cancer risk. We previously demonstrated that 400 mg celecoxib taken twice daily for 2 weeks lowered circulating plasma and breast nipple aspirate fluid (NAF) prostaglandin (PG)E2 concentrations in post- but not premenopausal high risk women. We hypothesized that circulating concentrations of celecoxib influenced PGE2 response, and that plasma levels of the drug are influenced by menopausal status. To address these hypotheses, the aims of the study were to determine: 1) if circulating plasma concentrations of celecoxib correlated with the change in plasma or NAF PGE2 concentrations …

Bradykinin Type 2 Receptor Be1 Genotype Influences Bradykinin-Dependent Vasodilation During Angiotensin-Converting Enzyme Inhibition, Gary Van Guilder, Mias Pretorius, James M Luther, J Brian Byrd, Kevin Hill, James V Gainer, Nancy J Brown

Health and Nutritional Sciences Faculty Publications

To test the hypothesis that the bradykinin receptor 2 (BDKRB2) BE1+9/-9 polymorphism affects vascular responses to bradykinin, we measured the effect of intra-arterial bradykinin on forearm blood flow and tissue-type plasminogen activator (t-PA) release in 89 normotensive, nonsmoking, white American subjects in whom degradation of bradykinin was blocked by enalaprilat. BE1 genotype frequencies were +9/+9:+9/-9:-9/-9=19:42:28. BE1 genotype was associated with systolic blood pressure (121.4+/-2.8, 113.8+/-1.8, and 110.6+/-1.8 mm Hg in +9/+9, +9/-9, and -9/-9 groups, respectively; P=0.007). In the absence of enalaprilat, bradykinin-stimulated forearm blood flow, forearm vascular resistance, and net t-PA release were similar among genotype groups. Enalaprilat increased …

Bifidobacteria In Feces And Environmental Waters, Regina Lamendella, Jorge W. Santo Domingo, Catherine A. Kelty, Daniel B. Oerther

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Bifidobacteria have been recommended as potential indicators of human fecal pollution in surface waters even though very little is known about their presence in nonhuman fecal sources. The objective of this research was to shed light on the occurrence and molecular diversity of this fecal indicator group in different animals and environmental waters. Genus- and species-specific 16S rRNA gene PCR assays were used to study the presence of bifidobacteria among 269 fecal DNA extracts from 32 different animals. Twelve samples from three wastewater treatment plants and 34 water samples from two fecally impacted watersheds were also tested. The species-specific assays …

Preimplantation Embryo Programming: Transcription, Epigenetics, And Culture Environment., Veronique Duranthon, Andrew J Watson, Patrick Lonergan

Obstetrics & Gynaecology Publications

Preimplantation development directs the formation of an implantation- or attachment-competent embryo so that metabolic interactions with the uterus can occur, pregnancy can be initiated, and fetal development can be sustained. The preimplantation embryo exhibits a form of autonomous development fueled by products provided by the oocyte and also from activation of the embryo's genome. Despite this autonomy, the preimplantation embryo is highly influenced by factors in the external environment and in extreme situations, such as those presented by embryo culture or nuclear transfer, the ability of the embryo to adapt to the changing environmental conditions or chromatin to become reprogrammed …

Antidepressant Prescribing Practices For The Treatment Of Children And Adolescents., Supriya K. Bhatia, Amy J. Rezac-Elgohary, Benedetto Vitiello, Michael A. Sitorius, Bruce A. Buehler, Christopher J. Kratochvil

Journal Articles: Psychiatry

OBJECTIVE: This study evaluates pediatric antidepressant prescribing practices of Nebraska clinicians.

METHODS: Surveys were sent in July, 2005, to 1,521 prescribing clinicians throughout Nebraska to assess pediatric antidepressant use along with any practice changes following the U.S. Food and Drug Administration (FDA) "black box" warning issued in October, 2004.

RESULTS: Over half (n = 866) of the clinicians responded to the survey, of which 96.8% reported awareness of the FDA "black box" warning. Of the respondents, 76.9% (n = 666) were prescribing antidepressants to children and/or adolescents. Clinicians reported decreased prescribing frequency for both children (15.5%) and adolescents (36.6%), with …

Current Application Of Thoracoscopy In Children., Kuojen Tsao, Shawn D. St Peter, Susan W. Sharp, Abhilash Nair, Walter S. Andrews, Ronald J. Sharp, Charles L. Snyder, Daniel J. Ostlie, G W. Holcomb Iii

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: The safety and efficacy of thoracoscopy for thoracic lesions and conditions in children is evolving. Our experience with thoracoscopy has expanded in recent years. Therefore, we reviewed our most recent 7-year experience to examine the current applications for thoracoscopy in children.

METHODS: A retrospective review of all patients undergoing a thoracoscopic operation at Children's Mercy Hospital (Kansas City, MO) between January 1, 2000, and June 18, 2007, was performed. Data points reviewed included patient demographics, type of operation, final diagnosis, complications, and recovery.

RESULTS: During the study period, 230 children underwent 231 thoracoscopic procedures. The mean age was 9.6 …

Arsenic As An Endocrine Disruptor: Arsenic Disrupts Retinoic Acid Receptor–And Thyroid Hormone Receptor–Mediated Gene Regulation And Thyroid Hormone–Mediated Amphibian Tail Metamorphosis, Jennifer C. Davey, Athena P. Nomikos, Manida Wungjiranirun, Jenna R. Sherman, Liam Ingram, Cavus Batki, Jean P. Lariviere, Joshua W. Hamilton

Dartmouth Scholarship

Background:

Chronic exposure to excess arsenic in drinking water has been strongly associated with increased risks of multiple cancers, diabetes, heart disease, and reproductive and developmental problems in humans. We previously demonstrated that As, a potent endocrine disruptor at low, environmentally relevant levels, alters steroid signaling at the level of receptor-mediated gene regulation for all five steroid receptors.

Objectives:

The goal of this study was to determine whether As can also disrupt gene regulation via the retinoic acid (RA) receptor (RAR) and/or the thyroid hormone (TH) receptor (TR) and whether these effects are similar to previously observed effects on steroid …

Focal White Matter Changes In Spasmodic Dysphonia: A Combined Diffusion Tensor Imaging And Neuropathological Study, Kristina Simonyan, Fernanda Tovar-Moll, John Ostuni, Mark Hallett, Victor F Kalasinsky, Michael R Lewin-Smith, Elisabeth J Rushing, Alexander O Vortmeyer, Christy L Ludlow

Faculty, Staff and Student Publications

Spasmodic dysphonia is a neurological disorder characterized by involuntary spasms in the laryngeal muscles during speech production. Although the clinical symptoms are well characterized, the pathophysiology of this voice disorder is unknown. We describe here, for the first time to our knowledge, disorder-specific brain abnormalities in these patients as determined by a combined approach of diffusion tensor imaging (DTI) and postmortem histopathology. We used DTI to identify brain changes and to target those brain regions for neuropathological examination. DTI showed right-sided decrease of fractional anisotropy in the genu of the internal capsule and bilateral increase of overall water diffusivity in …

Abeta42 Mutants With Different Aggregation Profiles Induce Distinct Pathologies In Drosophila., Koichi Iijima, Hsueh-Cheng Chiang, Stephen A Hearn, Inessa Hakker, Anthony Gatt, Christopher Shenton, Linda Granger, Amy Leung, Kanae Iijima-Ando, Yi Zhong

Department of Biochemistry and Molecular Biology Faculty Papers

Aggregation of the amyloid-beta-42 (Abeta42) peptide in the brain parenchyma is a pathological hallmark of Alzheimer's disease (AD), and the prevention of Abeta aggregation has been proposed as a therapeutic intervention in AD. However, recent reports indicate that Abeta can form several different prefibrillar and fibrillar aggregates and that each aggregate may confer different pathogenic effects, suggesting that manipulation of Abeta42 aggregation may not only quantitatively but also qualitatively modify brain pathology. Here, we compare the pathogenicity of human Abeta42 mutants with differing tendencies to aggregate. We examined the aggregation-prone, EOFAD-related Arctic mutation (Abeta42Arc) and an artificial mutation (Abeta42art) that …

Medulloblastomas Overexpress The P53-Inactivating Oncogene Wip1/Ppm1d, Robert C. Castellino, Massimiliano De Bortoli, Xiongbin Lu, Sung-Hwan Moon, Thuy-Ai Nguyen, Mark A. Shepard, Pulivarthi H. Rao, Lawrence A. Donehower, John Y H Kim

Faculty, Staff and Students Publications

Medulloblastoma is the most common malignant brain tumor of childhood. Despite numerous advances, clinical challenges range from recurrent and progressive disease to long-term toxicities in survivors. The lack of more effective, less toxic therapies results from our limited understanding of medulloblastoma growth. Although TP53 is the most commonly altered gene in cancers, it is rarely mutated in medulloblastoma. Accumulating evidence, however, indicates that TP53 pathways are disrupted in medulloblastoma. Wild-type p53-induced phosphatase 1 (WIP1 or PPM1D) encodes a negative regulator of p53. WIP1 amplification (17q22-q23) and its overexpression have been reported in diverse cancer types. We examined primary medulloblastoma specimens …