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Thomas SJ, Anderson MS, Adderson EE, Edgar L, Curtis D, Dong SW, Fatemi Y, Hecht SM, James SH, Lehman A, Michelow IC, Perez N, Sattler MM, Myers AL, Martin-Blais R. Pediatric Infectious Diseases Milestones: A Step in the Right Direction to Evaluate Subspecialty Learners. J Pediatric Infect Dis Soc 2023; 12:564-571. [PMID: 37813092 DOI: 10.1093/jpids/piad085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 10/07/2023] [Indexed: 10/11/2023]
Abstract
We share the work of the ACGME Pediatric Infectious Diseases Working Group in creating the Pediatric Infectious Diseases-Specific Milestones and discuss key considerations that lead to the reformation of competencies to better assess learners in Pediatric Infectious Diseases.
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Affiliation(s)
- Sanya J Thomas
- Host Defense Program, Section of Infectious Diseases, Nationwide Children's Hospital, Columbus, OH, USA
- Division of Infectious Diseases, Department of Pediatrics, Ohio State University College of Medicine, Columbus, OH, USA
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
| | - Marsha S Anderson
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- Section of Infectious Diseases, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Elisabeth E Adderson
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, USA
- Department of Pediatrics, University of Tennessee Health Sciences Center, Memphis, TN, USA
| | - Laura Edgar
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- The Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
| | - Donna Curtis
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- Section of Infectious Diseases, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Sara W Dong
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- Division of Infectious Diseases, Boston Children's Hospital, Harvard University, Boston, MA, USA
| | - Yasaman Fatemi
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- Division of Infectious Diseases, Department of Pediatrics, University of Washington School of Medicine and Seattle Children's Hospital, Seattle, WA, USA
| | - Shaina M Hecht
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- Division of Pediatric Infectious Diseases and Global Health, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Scott H James
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- Department of Pediatrics, Division of Pediatric Infectious Diseases, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Alice Lehman
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- Department of Pediatrics, Division of Pediatric Infectious Diseases, University of Minnesota, Minneapolis, MN, USA
| | - Ian C Michelow
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- Department of Pediatrics, Division of Infectious Diseases and Immunology, Connecticut Children's and University of Connecticut School of Medicine, Hartford, CT, USA
| | - Norma Perez
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- Department of Pediatrics, Division of Pediatric Infectious Diseases, University of Texas Health Science Center at Houston - McGovern Medical School, Houston, TX, USA
| | - Matthew M Sattler
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- Department of Pediatrics, Division of Infectious Diseases, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Angela L Myers
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- Division of Infectious Diseases, Children's Mercy Hospital, UMKC School of Medicine, Kansas City, MO, USA
| | - Rachel Martin-Blais
- Milestones 2.0 Work Group, Accreditation Council for Graduate Medical Education (ACGME), Chicago, IL, USA
- Section of Infectious Diseases, Nationwide Children's Hospital, Columbus, OH, USA
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Cole LD, Osborne CM, Silveira LJ, Rao S, Lockwood JM, Kunkel MJ, MacBrayne CE, Heizer HR, Anderson MS, Jone PN, Dominguez SR. IVIG Compared With IVIG Plus Infliximab in Multisystem Inflammatory Syndrome in Children. Pediatrics 2021; 148:e2021052702. [PMID: 34548377 DOI: 10.1542/peds.2021-052702] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/16/2021] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES To compare initial treatment with intravenous immunoglobulin (IVIG) versus IVIG plus infliximab in multisystem inflammatory syndrome in children (MIS-C). METHODS Single-center retrospective cohort study of patients with MIS-C who met Centers for Disease Control and Prevention criteria and received treatment from April 2020 to February 2021. Patients were included and compared on the basis of initial therapy of either IVIG alone or IVIG plus infliximab. The primary outcome was need for additional therapy 24 hours or more after treatment initiation. RESULTS Seventy-two children with MIS-C met inclusion criteria. Additional therapy was needed in 13 of 20 (65%) who received IVIG alone and 16 of 52 (31%) who received IVIG plus infliximab (P = .01). The median (interquartile range) ICU lengths of stay were 3.3 (2.2 to 3.8) and 1.8 (1.1 to 2.1) days, respectively (P = .001). New or worsened left ventricular dysfunction developed in 4 of 20 (20%) and 2 of 52 (4%) (P = .05), and new vasoactive medication requirement developed in 3 of 20 (15%) and 2 of 52 (4%), respectively (P = .13). The median percentage changes in the C-reactive protein level at 24 hours posttreatment compared with pretreatment were 0% (-29% to 66%) and -46% (-62% to -15%) (P < .001); and at 48 hours posttreatment, -5% (-41% to 57%) and -70% (-79% to -49%) respectively (P < .001). There was no significant difference in hospital length of stay, time to fever resolution, vasoactive medication duration, or need for diuretics. CONCLUSIONS Patients with MIS-C initially treated with IVIG plus infliximab compared with those treated with IVIG alone were less likely to require additional therapy and had decreased ICU length of stay, decreased development of left ventricular dysfunction, and more rapid decline in C-reactive protein levels.
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Affiliation(s)
| | | | - Lori J Silveira
- Department of Pediatrics, School of Medicine, University of Colorado, Aurora, Colorado
| | - Suchitra Rao
- Sections of Infectious Diseases
- Hospital Medicine
| | | | - Megan J Kunkel
- Department of Pediatrics, School of Medicine, University of Colorado, Aurora, Colorado
| | - Christine E MacBrayne
- Section of Infectious Diseases, Department of Pharmacy, School of Medicine, University of Colorado and Children's Hospital Colorado, Aurora, Colorado
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Philipsborn RP, Sheffield P, White A, Osta A, Anderson MS, Bernstein A. Climate Change and the Practice of Medicine: Essentials for Resident Education. Acad Med 2021; 96:355-367. [PMID: 32910006 DOI: 10.1097/acm.0000000000003719] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Despite calls for including content on climate change and its effect on health in curricula across the spectrum of medical education, no widely used resource exists to guide residency training programs in this effort. This lack of resources poses challenges for training program leaders seeking to incorporate evidence-based climate and health content into their curricula. Climate change increases risks of heat-related illness, infections, asthma, mental health disorders, poor perinatal outcomes, adverse experiences from trauma and displacement, and other harms. More numerous and increasingly dangerous natural disasters caused by climate change impair delivery of care by disrupting supply chains and compromising power supplies. Graduating trainees face a knowledge gap in understanding, managing, and mitigating these many-faceted consequences of climate change, which-expected to intensify in coming decades-will influence both the health of their patients and the health care they deliver. In this article, the authors propose a framework of climate change and health educational content for residents, including how climate change (1) harms health, (2) necessitates adaptation in clinical practice, and (3) undermines health care delivery. The authors propose not only learning objectives linked to the Accreditation Council for Graduate Medical Education core competencies for resident education but also learning formats and assessment strategies in each content area. They also present opportunities for implementation of climate and health education in residency training programs. Including this content in residency education will better prepare doctors to deliver anticipatory guidance to at-risk patients, manage those experiencing climate-related health effects, and reduce care disruptions during climate-driven extreme weather events.
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Affiliation(s)
- Rebecca Pass Philipsborn
- R.P. Philipsborn is assistant professor, Department of Pediatrics and Emory Global Health Institute, Emory University, Atlanta, Georgia; ORCID: https://orcid.org/0000-0002-2843-7509
| | - Perry Sheffield
- P. Sheffield is assistant professor, Department of Pediatrics and Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mt. Sinai, New York, New York; ORCID: http://orcid.org/0000-0001-9156-1193
| | - Andrew White
- A. White is James P. Keating Professor, Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri; ORCID: http://orcid.org/0000-0001-9394-7823
| | - Amanda Osta
- A. Osta is associate professor of internal medicine and pediatrics and division chief for education, Department of Pediatrics, University of Illinois, and was, at the time of this research, director, Pediatric Residency Program, UI Health, Chicago, Illinois
| | - Marsha S Anderson
- M.S. Anderson is professor, Department of Pediatrics, associate director, Pediatric Residency Program, and assistant dean, Longitudinal Curriculum, University of Colorado School of Medicine, Aurora, Colorado
| | - Aaron Bernstein
- A. Bernstein is assistant professor of pediatrics, Harvard Medical School and Boston Children's Hospital, Boston, Massachusetts; ORCID: http://orcid.org/0000-0003-1703-1041
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Hao S, Ling XB, Kanegaye JT, Bainto E, Dominguez SR, Heizer H, Jone PN, Anderson MS, Jaggi P, Baker A, Son MB, Newburger JW, Ashouri N, McElhinney DB, Burns JC, Whitin JC, Cohen HJ, Tremoulet AH. Multicentre validation of a computer-based tool for differentiation of acute Kawasaki disease from clinically similar febrile illnesses. Arch Dis Child 2020; 105:772-777. [PMID: 32139365 DOI: 10.1136/archdischild-2019-317980] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 01/30/2020] [Accepted: 02/03/2020] [Indexed: 11/03/2022]
Abstract
BACKGROUND The clinical features of Kawasaki disease (KD) overlap with those of other paediatric febrile illnesses. A missed or delayed diagnosis increases the risk of coronary artery damage. Our computer algorithm for KD and febrile illness differentiation had a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 94.8%, 70.8%, 93.7% and 98.3%, respectively, in a single-centre validation study. We sought to determine the performance of this algorithm with febrile children from multiple institutions across the USA. METHODS We used our previously published 18-variable panel that includes illness day, the five KD clinical criteria and readily available laboratory values. We applied this two-step algorithm using a linear discriminant analysis-based clinical model followed by a random forest-based algorithm to a cohort of 1059 acute KD and 282 febrile control patients from five children's hospitals across the USA. RESULTS The algorithm correctly classified 970 of 1059 patients with KD and 163 of 282 febrile controls resulting in a sensitivity of 91.6%, specificity of 57.8% and PPV and NPV of 95.4% and 93.1%, respectively. The algorithm also correctly identified 218 of the 232 KD patients (94.0%) with abnormal echocardiograms. INTERPRETATION The expectation is that the predictive accuracy of the algorithm will be reduced in a real-world setting in which patients with KD are rare and febrile controls are common. However, the results of the current analysis suggest that this algorithm warrants a prospective, multicentre study to evaluate its potential utility as a physician support tool.
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Affiliation(s)
- Shiying Hao
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California, USA.,Clinical and Translational Research Program, Betty Irene Moore Children's Heart Center, Lucile Packard Children's Hospital, Palo Alto, California, USA
| | - Xuefeng B Ling
- Clinical and Translational Research Program, Betty Irene Moore Children's Heart Center, Lucile Packard Children's Hospital, Palo Alto, California, USA .,Department of Surgery, Stanford University School of Medicine, Stanford, California, USA
| | - John T Kanegaye
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA.,Rady Children's Hospital, San Diego, California, USA
| | - Emelia Bainto
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA.,Rady Children's Hospital, San Diego, California, USA
| | - Samuel R Dominguez
- Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado, USA
| | - Heather Heizer
- Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado, USA
| | - Pei-Ni Jone
- Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado, USA
| | - Marsha S Anderson
- Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado, USA
| | - Preeti Jaggi
- Department of Pediatrics, Emory University, Atlanta, Georgia, USA
| | - Annette Baker
- Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Mary Beth Son
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.,Division of Immunology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Jane W Newburger
- Department of Cardiology, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Negar Ashouri
- Department of Pediatrics, CHOC Children's Hospital, Orange, California, USA
| | - Doff B McElhinney
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, California, USA.,Clinical and Translational Research Program, Betty Irene Moore Children's Heart Center, Lucile Packard Children's Hospital, Palo Alto, California, USA
| | - Jane C Burns
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA.,Rady Children's Hospital, San Diego, California, USA
| | - John C Whitin
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA
| | - Harvey J Cohen
- Department of Pediatrics, Stanford University School of Medicine, Stanford, California, USA
| | - Adriana H Tremoulet
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA .,Rady Children's Hospital, San Diego, California, USA
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5
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Tremoulet AH, Jain S, Jone PN, Best BM, Duxbury EH, Franco A, Printz B, Dominguez SR, Heizer H, Anderson MS, Glodé MP, He F, Padilla RL, Shimizu C, Bainto E, Pancheri J, Cohen HJ, Whitin JC, Burns JC. Phase I/IIa Trial of Atorvastatin in Patients with Acute Kawasaki Disease with Coronary Artery Aneurysm. J Pediatr 2019; 215:107-117.e12. [PMID: 31561960 PMCID: PMC6878161 DOI: 10.1016/j.jpeds.2019.07.064] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/17/2019] [Accepted: 07/24/2019] [Indexed: 12/13/2022]
Abstract
OBJECTIVES To determine the safety, tolerability, pharmacokinetics, and immunomodulatory effects of a 6-week course of atorvastatin in patients with acute Kawasaki disease with coronary artery (CA) aneurysm (CAA). STUDY DESIGN This was a Phase I/IIa 2-center dose-escalation study of atorvastatin (0.125-0.75 mg/kg/day) in 34 patients with Kawasaki disease (aged 2-17 years) with echocardiographic evidence of CAA. We measured levels of the brain metabolite 24(S)-hydroxycholesterol (24-OHC), serum lipids, acute-phase reactants, liver enzymes, and creatine phosphokinase; peripheral blood mononuclear cell populations; and CA internal diameter normalized for body surface area before atorvastatin treatment and at 2 and 6 weeks after initiation of atorvastatin treatment. RESULTS A 6-week course of up to 0.75 mg/kg/day of atorvastatin was well tolerated by the 34 subjects (median age, 5.3 years; IQR, 2.6-6.4 years), with no serious adverse events attributable to the study drug. The areas under the curve for atorvastatin and its metabolite were larger in the study subjects compared with those reported in adults, suggesting a slower rate of metabolism in children. The 24-OHC levels were similar between the atorvastatin-treated subjects and matched controls. CONCLUSIONS Atorvastatin was safe and well tolerated in our cohort of children with acute Kawasaki disease and CAA. A Phase III efficacy trial is warranted in this patient population, which may benefit from the known anti-inflammatory and immunomodulatory effects of this drug.
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Affiliation(s)
- Adriana H. Tremoulet
- Kawasaki Disease Research Center, Department of Pediatrics, University of California San Diego, La Jolla, California, USA; Rady Children’s Hospital San Diego, San Diego, California, USA
| | - Sonia Jain
- Biostatistics Research Center, Department of Family Medicine and Public Health, University of California San Diego, La Jolla, California
| | - Pei-Ni Jone
- Pediatric Cardiology, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, CO
| | - Brookie M. Best
- Kawasaki Disease Research Center, Department of Pediatrics, University of California San Diego, La Jolla, California, USA; Rady Children’s Hospital San Diego, San Diego, California, USA,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA
| | - Elizabeth H. Duxbury
- Kawasaki Disease Research Center, Department of Pediatrics, University of California San Diego, La Jolla, California, USA; Rady Children’s Hospital San Diego, San Diego, California, USA,Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, CA
| | - Alessandra Franco
- Kawasaki Disease Research Center, Department of Pediatrics, University of California San Diego, La Jolla, California, USA; Rady Children’s Hospital San Diego, San Diego, California, USA
| | - Beth Printz
- Kawasaki Disease Research Center, Department of Pediatrics, University of California San Diego, La Jolla, California, USA; Rady Children’s Hospital San Diego, San Diego, California, USA
| | - Samuel R. Dominguez
- Pediatric Infectious Disease, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, CO
| | - Heather Heizer
- Pediatric Infectious Disease, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, CO
| | - Marsha S. Anderson
- Pediatric Infectious Disease, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, CO
| | - Mary P. Glodé
- Pediatric Infectious Disease, Children’s Hospital Colorado, University of Colorado School of Medicine, Aurora, CO
| | - Feng He
- Biostatistics Research Center, Department of Family Medicine and Public Health, University of California San Diego, La Jolla, California
| | - Robert L. Padilla
- Kawasaki Disease Research Center, Department of Pediatrics, University of California San Diego, La Jolla, California, USA; Rady Children’s Hospital San Diego, San Diego, California, USA
| | - Chisato Shimizu
- Kawasaki Disease Research Center, Department of Pediatrics, University of California San Diego, La Jolla, California, USA; Rady Children’s Hospital San Diego, San Diego, California, USA
| | - Emelia Bainto
- Kawasaki Disease Research Center, Department of Pediatrics, University of California San Diego, La Jolla, California, USA; Rady Children’s Hospital San Diego, San Diego, California, USA
| | - Joan Pancheri
- Kawasaki Disease Research Center, Department of Pediatrics, University of California San Diego, La Jolla, California, USA; Rady Children’s Hospital San Diego, San Diego, California, USA
| | | | - John C. Whitin
- Department of Pediatrics, Stanford University, Stanford, CA
| | - Jane C. Burns
- Kawasaki Disease Research Center, Department of Pediatrics, University of California San Diego, La Jolla, California, USA; Rady Children’s Hospital San Diego, San Diego, California, USA
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Haftel HM, Swan R, Anderson MS, Caputo GL, Frohna JG, Li STT, Shugerman RP, Trimm F, Vinci RJ, Waggoner-Fountain LA, Bostwick SB. Fostering the Career Development of Future Educational Leaders: The Success of the Association of Pediatric Program Directors Leadership in Educational Academic Development Program. J Pediatr 2018; 194:5-6.e1. [PMID: 29478508 DOI: 10.1016/j.jpeds.2017.11.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 11/29/2017] [Indexed: 11/20/2022]
Affiliation(s)
- Hilary M Haftel
- C.S. Mott Children's Hospital/University of Michigan Medical School, Ann Arbor, MI.
| | - Rebecca Swan
- Vanderbilt University School of Medicine, Nashville, TN
| | | | | | - John G Frohna
- University of Wisconsin School of Medicine and Public Health, Madison, WI
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Caro L, de Hoon J, Depré M, Cilissen C, Miller J, Gao W, Panebianco D, Guo Z, Troemel SL, Anderson MS, Uemura N, Butterton J, Wagner J, Wright DH. Single-Dose and Multiple-Dose Pharmacokinetics of Vaniprevir in Healthy Men. Clin Transl Sci 2017; 10:480-486. [PMID: 28796416 PMCID: PMC6402189 DOI: 10.1111/cts.12482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 05/22/2017] [Indexed: 12/26/2022] Open
Abstract
Vaniprevir is an inhibitor of the hepatitis C virus (HCV) NS3/4A protease. The aim of these double‐blind, placebo‐controlled phase I studies was to evaluate the safety and pharmacokinetics of vaniprevir in healthy male volunteers. The primary objective for both studies was the safety and tolerability of vaniprevir. Single‐dose and steady‐state pharmacokinetics were also assessed. In both studies, there was no apparent relationship between the frequency or intensity of adverse events and vaniprevir dose. At single doses >20 mg, the plasma area under the curve (AUC)0–∞ and maximum concentration (Cmax) increased in a greater‐than‐dose‐proportional manner. The geometric mean ratios (GMRs; fed/fasted) were 1.22 and 0.79 for AUC0–∞ and Cmax, respectively. Following multiple doses, GMR accumulations for AUC0–12h and Cmax (day 14/day 1) ranged from 1.53 to 1.90 and from 1.41 to 1.92, respectively. These data support the use of vaniprevir with peginterferon and ribavirin in patients with HCV infection.
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Affiliation(s)
- L Caro
- Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - J de Hoon
- Center for Clinical Pharmacology, University Hospitals, Leuven, Belgium
| | - M Depré
- Center for Clinical Pharmacology, University Hospitals, Leuven, Belgium
| | - C Cilissen
- Merck Sharp & Dohme (Europe) Inc., Brussels, Belgium
| | - J Miller
- Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - W Gao
- Merck & Co., Inc., Kenilworth, New Jersey, USA
| | | | - Z Guo
- Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - S L Troemel
- Merck & Co., Inc., Kenilworth, New Jersey, USA
| | | | - N Uemura
- Merck & Co., Inc., Kenilworth, New Jersey, USA.,Current affiliation: Oita University, Oita, Japan
| | - J Butterton
- Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - J Wagner
- Merck & Co., Inc., Kenilworth, New Jersey, USA.,Current affiliation: Takeda Pharmaceuticals U.S.A., Inc., Deerfield, Illinois, USA
| | - D H Wright
- Merck & Co., Inc., Kenilworth, New Jersey, USA
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8
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Aylor M, Cruz M, Narayan A, Yu CC, Lopreiato J, Mann KJ, Acholonu RG, Turner TL, Serwint JR, Sectish TC, Anderson MS, Spector ND. Optimizing Your Mentoring Relationship: A Toolkit for Mentors and Mentees. MedEdPORTAL 2016; 12:10459. [PMID: 31008237 PMCID: PMC6464436 DOI: 10.15766/mep_2374-8265.10459] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 08/25/2016] [Indexed: 06/02/2023]
Abstract
INTRODUCTION Mentorship is a vital component of academic and professional development. Mentees report positive impacts from mentorship programs, yet institutions and societies may struggle to meet their mentees' needs due to factors such as mentor fatigue and lack of mentor training. To address this in our own professional society, the Association of Pediatric Program Directors, we developed a mentor toolkit in order to utilize a variety of mentoring models, provide faculty development for midlevel mentors, and offer guidance to mentees. METHODS Most of these tools were designed to be administered in an interactive format such as a workshop or seminar with think-pair-share opportunities. The toolkit begins by providing a definition of mentoring and reinforcing the benefits and the characteristics of effective mentoring relationships. Next, we discuss the important role that mentees have in creating and maintaining effective mentoring relationships (i.e., mentee-driven mentoring). We then introduce a mentoring mosaic activity designed to help mentees examine their professional network and think about how they might expand it to fulfill the spectrum of their mentoring needs. Next, we present guidelines for the implementation of four mentoring models that can be used within one's institution: traditional dyadic mentoring, peer group mentoring, meet the professor mentoring, and speed mentoring. We then provide tools that can be used to help facilitate effective mentoring development. RESULTS This toolkit has successfully served as a self-guided resource at national meetings for many years, garnering positive feedback from mentors and mentees alike. DISCUSSION The principles and methods are easily generalizable and may be used to guide mentorship programs within institutional and professional societies, as well as to assist mentors and mentees in optimizing their individual mentoring relationships.
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Affiliation(s)
- Megan Aylor
- Clinical Associate Professor, Department of Pediatrics, Oregon Health & Science University School of Medicine
| | - Mario Cruz
- Community Pediatrician, St. Christopher's Hospital for Children
- Assistant Professor, Department of Pediatrics, St. Christopher's Hospital for Children
| | - Aditee Narayan
- Associate Professor, Department of Pediatrics, Duke University Medical Center
| | - Col. Clifton Yu
- Director of Graduate Medical Education, Walter Reed National Military Medical Center
- Associate Professor of Pediatrics, Uniformed Services University of the Health Sciences
| | - Joseph Lopreiato
- Professor, Department of Pediatrics and Medicine, Uniformed Services University of the Health Sciences
| | - Keith J. Mann
- Professor, Department of Pediatrics, University of Missouri-Kansas City School of Medicine
- Professor, Department of Pediatrics, Children's Mercy Hospital
| | - Rhonda Graves Acholonu
- Clinical Assistant Professor, Department of Pediatrics, New York University School of Medicine
| | - Teri Lee Turner
- Associate Professor, Department of Pediatrics, Baylor College of Medicine
| | - Janet R. Serwint
- Professor, Department of Pediatrics, Johns Hopkins University School of Medicine
| | | | - Marsha S. Anderson
- Professor, Department of Pediatrics, University of Colorado School of Medicine
| | - Nancy D. Spector
- Professor, Department of Pediatrics, Drexel University College of Medicine
- Professor, Department of Pediatrics, St. Christopher's Hospital for Children
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Dominguez SR, Martin B, Heizer H, Jone PN, Tong S, Davidson J, Anderson MS, Glodé MP. Procalcitonin (PCT) and Kawasaki Disease: Does PCT Correlate With IVIG-Resistant Disease, Admission to the Intensive Care Unit, or Development of Coronary Artery Lesions? J Pediatric Infect Dis Soc 2016; 5:297-302. [PMID: 26407256 DOI: 10.1093/jpids/piv019] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 03/17/2015] [Indexed: 11/13/2022]
Abstract
BACKGROUND Kawasaki disease (KD) remains a clinical diagnosis due to the absence of a sensitive and specific diagnostic test. There are limited published data on the usefulness of procalcitonin (PCT) as a biomarker for the diagnosis or prognosis of children with KD. We hypothesized that PCT might be useful in predicting coronary artery lesions (CALs) and intravenous immunoglobulin (IVIG) resistance. METHODS Eighty-five children with KD who were hospitalized within the first 10 days of illness were retrospectively reviewed. PCT was measured on stored serum or plasma samples obtained at the time of admission (pre-IVIG). Data were analyzed to determine whether there were statistically significant associations with PCT, erythrocyte sedimentation rate, and C-reactive protein levels and the incidence of CALs, pediatric intensive care unit admission, or IVIG-resistant disease in KD patients. RESULTS PCT values in children hospitalized with acute KD ranged from 0.1 ng/mL to 143.9 ng/mL, with a median of 0.49 ng/mL (IQR 0.23-1.29 ng/mL). There was no correlation of PCT with patient age, race, or sex, but it was correlated with day of illness. KD patients with a PCT ≥ 0.5 ng/mL had a significantly higher incidence of IVIG-resistant disease (29% versus 7%, P = .02). There was no association between PCT and development of CALs in our sample. CONCLUSIONS Additional research is needed to establish the sensitivity and specificity of PCT for the diagnosis of KD. PCT may be of value in predicting which children are at increased risk for IVIG-resistant disease.
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Affiliation(s)
| | - Blake Martin
- Department of Pediatrics, Section of Infectious Diseases
| | - Heather Heizer
- Department of Pediatrics, Section of Infectious Diseases
| | - Pei-Ni Jone
- Department of Pediatrics, Section of Cardiology
| | - Suhong Tong
- Department of Pediatrics, Section of Biostatistics, University of Colorado Denver School of Medicine and Children's Hospital Colorado, Aurora
| | | | | | - Mary P Glodé
- Department of Pediatrics, Section of Infectious Diseases
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10
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Kraft WK, Gilmartin JH, Chappell DL, Gheyas F, Walker BM, Nagalla S, Naik UP, Horrow JC, Wrishko RE, Zhang S, Anderson MS. Effect of Vorapaxar Alone and in Combination with Aspirin on Bleeding Time and Platelet Aggregation in Healthy Adult Subjects. Clin Transl Sci 2016; 9:221-7. [PMID: 27304196 PMCID: PMC5351335 DOI: 10.1111/cts.12405] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 05/17/2016] [Accepted: 05/12/2016] [Indexed: 11/25/2022] Open
Abstract
The effect of the protease‐activated receptor‐1 (PAR‐1) antagonist vorapaxar on human bleeding time is not known. This was a randomized, two‐period, open‐label trial in healthy men (n = 31) and women (n = 5). In period 1, subjects received 81 mg aspirin q.d. or a vorapaxar regimen achieving steady‐state plasma concentrations equivalent to chronic 2.5 mg q.d. doses, for 7 days. In period 2, each group added 7 days of the therapy alternate to that of period 1 without washout. Bleeding time and platelet aggregation using arachidonic acid, ADP, and TRAP agonists were assessed. Bleeding time geometric mean ratio (90% CI) for vorapaxar/baseline was 1.01 (0.88–1.15), aspirin/baseline was 1.32 (1.15–1.51), vorapaxar + aspirin/vorapaxar was 1.47 (1.26–1.70), and vorapaxar + aspirin/aspirin was 1.12 (0.96–1.30). Unlike aspirin, vorapaxar did not prolong bleeding time compared with baseline. Bleeding time following administration of vorapaxar with aspirin was similar to that following aspirin alone.
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Affiliation(s)
- W K Kraft
- Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | | | | | - F Gheyas
- Merck & Co, Kenilworth, New Jersey, USA
| | | | - S Nagalla
- Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - U P Naik
- Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | | | | | - S Zhang
- Merck & Co, Kenilworth, New Jersey, USA
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11
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Frank B, Davidson J, Tong S, Martin B, Heizer H, Anderson MS, Glode MP, Dominguez SR, Jone PN. Myocardial Strain and Strain Rate in Kawasaki Disease: Range, Recovery, and Relationship to Systemic Inflammation/Coronary Artery Dilation. J Clin Exp Cardiolog 2016; 7. [PMID: 27182455 PMCID: PMC4866607 DOI: 10.4172/2155-9880.1000432] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Kawasaki Disease (KD), a systemic vasculitis of medium sized vessels, is the most common cause of acquired heart disease among children in the developed world. Some KD patients demonstrate echocardiographic evidence of depressed myocardial mechanics. However, the incidence, etiology, and reversibility of abnormal mechanics in KD patients remain undefined. METHODS AND RESULTS We retrospectively studied 41 KD patients and measured myocardial strain and strain rate by velocity vector imaging from pre-treatment and convalescent echocardiograms. Pre-treatment procalcitonin, C-reactive protein (CRP), and coronary artery z-scores were obtained in all patients and compared between the groups with preserved versus depressed acute phase mechanics. The change in mechanics between the acute and convalescent phases was also assessed. Patients with initially low longitudinal strain improved by the convalescent period (mean difference - 4.0%; p<0.005) with the greatest improvement occurring in patients with the lowest initial strain (-7.3%; p<0.05). Patients with higher initial strain did not change significantly by the convalescent period. Patients with lower longitudinal and circumferential strain demonstrated higher median procalcitonin levels (1.2 vs. 0.3 ng/mL; p<0.05 and 1.8 vs. 0.4 ng/mL; p<0.05 respectively) and a trend towards higher CRP, but no difference in coronary artery z-scores. Strain rate was not associated with inflammatory markers or coronary artery z-scores. CONCLUSIONS The range of strain found in our cohort was large. Improvement in mean strain was driven primarily by patients with lower initial strain. Lower strain was associated with increased markers of systemic inflammation, but not proximal coronary artery changes.
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Affiliation(s)
- Benjamin Frank
- Department of Pediatrics and Section of Cardiology, Children's Hospital Colorado/University of Colorado, Denver, USA
| | - Jesse Davidson
- Department of Pediatrics and Section of Cardiology, Children's Hospital Colorado/University of Colorado, Denver, USA
| | - Suhong Tong
- Department of Biostatistics, Children's Hospital Colorado/University of Colorado, Denver, USA
| | - Blake Martin
- Department of Pediatrics and Section of Infectious Diseases, Children's Hospital Colorado/University of Colorado, Denver, USA
| | - Heather Heizer
- Department of Pediatrics and Section of Infectious Diseases, Children's Hospital Colorado/University of Colorado, Denver, USA
| | - Marsha S Anderson
- Department of Pediatrics and Section of Infectious Diseases, Children's Hospital Colorado/University of Colorado, Denver, USA
| | - Mary P Glode
- Department of Pediatrics and Section of Infectious Diseases, Children's Hospital Colorado/University of Colorado, Denver, USA
| | - Samuel R Dominguez
- Department of Pediatrics and Section of Infectious Diseases, Children's Hospital Colorado/University of Colorado, Denver, USA
| | - Pei-Ni Jone
- Department of Pediatrics and Section of Cardiology, Children's Hospital Colorado/University of Colorado, Denver, USA
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12
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Phadke D, Patel SS, Dominguez SR, Heizer H, Anderson MS, Glode MP, Jone PN. Tissue Doppler Imaging as a Predictor of Immunoglobulin Resistance in Kawasaki Disease. Pediatr Cardiol 2015; 36:1618-23. [PMID: 25991572 DOI: 10.1007/s00246-015-1206-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 05/14/2015] [Indexed: 12/19/2022]
Abstract
Kawasaki disease (KD) is characterized by myocarditis and left ventricular dysfunction during the acute phase of the illness. Despite treatment with intravenous immunoglobulin (IVIG), a significant number of patients are IVIG resistant. We evaluated KD patients in the acute phase of illness using tissue Doppler imaging (TDI) to assess whether myocardial dysfunction may predict IVIG resistance. All patients with acute KD presenting to Children's Hospital Colorado from February 2007 through March 2014 were included in this study and underwent echocardiograms with TDI evaluation at diagnosis. Patients were divided into two groups: IVIG resistant and IVIG responder. Group differences were assessed using Wilcoxon-Mann-Whitney and Chi-square testing. Receiver operating characteristic (ROC) curve analysis was utilized to determine threshold values of TDI measurements associated with IVIG resistance. Fifty-one age-matched IVIG resistant patients were compared to 51 IVIG responder patients [median age, IQR 44.57 (20.13-77.07) vs. 33.49 (17.30-62.89) months, p < 0.44]. There were significant differences in the septal and mitral early diastolic velocities (E') (p < 0.001 and p < 0.01), respectively. ROC analysis demonstrated that tricuspid E' <0.15 cm/s, septal E' <0.12 cm/s, and mitral E' <0.16 cm/s were good predictors of IVIG unresponsiveness (AUC = 0.66, 0.66, and 0.70, respectively). There were no differences between the systolic velocities and late diastolic velocities (A'). IVIG resistant KD patients present with significantly greater diastolic dysfunction compared to responders in patients with KD. TDI may be a useful tool to differentiate KD patients at higher risk of IVIG resistance.
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Affiliation(s)
- Daniel Phadke
- Department of Biology, University of Alabama, Tuscaloosa, AL, USA
| | - Sonali S Patel
- Pediatric Cardiology, Children's Hospital Colorado, University of Colorado School of Medicine, 13123 East 16th Avenue, B100, Aurora, CO, 80045, USA
| | - Samuel R Dominguez
- Pediatric Infectious Disease, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, USA
| | - Heather Heizer
- Pediatric Infectious Disease, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, USA
| | - Marsha S Anderson
- Pediatric Infectious Disease, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, USA
| | - Mary P Glode
- Pediatric Infectious Disease, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO, USA
| | - Pei-Ni Jone
- Pediatric Cardiology, Children's Hospital Colorado, University of Colorado School of Medicine, 13123 East 16th Avenue, B100, Aurora, CO, 80045, USA.
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13
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Abstract
BACKGROUND The diagnosis of Kawasaki disease (KD) remains challenging without a definitive diagnostic test and currently is guided by using clinical patient characteristics and supported by laboratory data. The role of respiratory viruses in the pathogenesis of KD is not fully understood. METHODS Charts of patients with KD admitted to Children's Hospital Colorado from January 2009 to May 2013 were retrospectively reviewed. Patients with KD who had a nasopharyngeal wash submitted for multiplex polymerase chain reaction (PCR) viral testing were included. Clinical characteristics, laboratory data, and outcomes of patients with and without positive respiratory viral PCR results were compared. RESULTS Of 222 patients with KD admitted to the hospital, 192 (86%) had a respiratory viral PCR test performed on or shortly after admission. Ninety-three (41.9%) of the 192 patients with KD had a positive respiratory viral PCR, and the majority were positive for rhinovirus/enterovirus. No statistically significant differences were found in the clinical characteristics and laboratory values between the groups with and without positive respiratory viral PCR findings. Both groups had the same frequency of upper respiratory and gastrointestinal symptoms and had the same incidence of admission to the PICU, intravenous immunoglobulin-resistant disease, and coronary artery lesions. CONCLUSIONS No differences in clinical presentations or outcomes in children with KD stratified according to positive or negative respiratory viral PCR testing were observed. A positive respiratory viral PCR or presence of respiratory symptoms at the time of presentation should not be used to exclude a diagnosis of KD.
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Affiliation(s)
| | | | | | - Pei-Ni Jone
- Cardiology, Department of Pediatrics, University of Colorado Denver School of Medicine and Children's Hospital Colorado, Aurora, Colorado
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Narayan AP, McPhillips HA, Anderson MS, Gardner L, Larrabee J, Poynter S, Mann KJ, Spector ND. Strengthening the associate program director workforce: needs assessment and recommendations. Acad Pediatr 2014; 14:332-4. [PMID: 24976345 DOI: 10.1016/j.acap.2014.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 05/12/2014] [Indexed: 11/24/2022]
Affiliation(s)
- Aditee P Narayan
- Department of Pediatrics, Duke University Medical Center, Durham, NC.
| | | | - Marsha S Anderson
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colo
| | - Lynn Gardner
- Department of Pediatrics, Emory University School of Medicine, Atlanta, Ga
| | - Jerry Larrabee
- Department of Pediatrics, University of Vermont, Burlington, Vt
| | - Sue Poynter
- Department of Pediatrics, Cincinnati Children's Hospital, Cincinnati, Ohio
| | - Keith J Mann
- Department of Pediatrics, University of Missouri-Kansas City School of Medicine and Children's Mercy Hospitals and Clinics, Kansas City, Mo
| | - Nancy D Spector
- Department of Pediatrics Drexel University College of Medicine, Section of General Pediatrics St. Christopher's Hospital for Children, Philadelphia, Pa
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15
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Abstract
This report describes a case of West Nile virus (WNV) meningoencephalitis in a child who presented with fever, headache, seizures, and altered mental status, as well as hyponatremia and bronzing of the skin. Findings that led to the diagnosis of WNV included plasma-cell pleocytosis of the cerebrospinal fluid (CSF) and linear chorioretinitis on ophthalmologic exam. The diagnosis was confirmed by a positive serum and CSF WNV IgM. The acute WNV infection triggered an adrenal crisis which uncovered a new diagnosis of underlying Addison's disease. This is the first case report of severe neuroinvasive WNV disease in a pediatric patient with primary adrenal insufficiency. Neuroinvasive WNV disease is uncommon in children, but may have a more severe presentation in those with certain underlying medical conditions.
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Affiliation(s)
- Kevin Messacar
- Department of Pediatrics, Section of Infectious Diseases, University of Colorado School of Medicine, Aurora, CO 80045, USA
- Corresponding author at: Children's Hospital Colorado, University of Colorado, Department of Pediatrics, Section of Infectious Diseases, B055, 13123 E 16th Avenue, Aurora, CO 80045, USA. Tel.: +1 720 777 2838; fax: +1 720 777 7295.
| | - Melanie Cree-Green
- Department of Pediatrics, Section of Endocrinology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Mark Lovell
- Department of Pathology, Children's Hospital Colorado, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Marsha S. Anderson
- Department of Pediatrics, Section of Infectious Diseases, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Samuel R. Dominguez
- Department of Pediatrics, Section of Infectious Diseases, University of Colorado School of Medicine, Aurora, CO 80045, USA
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16
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Abstract
An atomic force microscope (AFM) is presented as an instrument for rapid, miniaturized chromatography. The AFM is used to inject a sample, provide shear driven liquid flow over a functionalized substrate, and detect separated components. The components are then analyzed with surface enhanced Raman spectroscopy using AFM deposition of gold nanoparticles on the separated bands. This AFM mediated chromatography (AFM-MC) is demonstrated using lipophilic dyes and normal phase chemistry. A significant reduction in both size and separation time scales is achieved with 25 μm length scale and 1 s separation times. AFM-MC has general applications to trace chemical analysis and microfluidics.
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Affiliation(s)
- M S Anderson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.
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17
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Anderson MS, Katz I, Petkov M, Blakkolb B, Mennella J, D'Agostino S, Crisp J, Evans J, Feldman J, Limonadi D. In situ cleaning of instruments for the sensitive detection of organics on Mars. Rev Sci Instrum 2012; 83:105109. [PMID: 23126806 DOI: 10.1063/1.4757861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A method is presented for in situ cleaning of spacecraft instruments that analyze planetary soil and rock. We have found that vibrating hardware, used to facilitate powder transport, was also effective at removing contamination. Surfaces can be cleaned below monolayer levels using vibrating surfaces in the presence of mineral powder. Both organic and particulate contamination is efficiently removed. Fine grained regolith from the planetary surface or an organic free reference material may serve as the powder used for cleaning. We present both analytical and experimental results for the contamination transfer fraction and the conditions required to clean the hardware prior to sensitive chemical analysis.
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Affiliation(s)
- M S Anderson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.
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18
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Anderson MS, Katz I, Petkov M, Blakkolb B, Mennella J, D'Agostino S, Crisp J, Evans J, Feldman J, Limonadi D. In situ cleaning of instruments for the sensitive detection of organics on Mars. Rev Sci Instrum 2012. [PMID: 23126806 DOI: 10.1063/1061.4757861] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A method is presented for in situ cleaning of spacecraft instruments that analyze planetary soil and rock. We have found that vibrating hardware, used to facilitate powder transport, was also effective at removing contamination. Surfaces can be cleaned below monolayer levels using vibrating surfaces in the presence of mineral powder. Both organic and particulate contamination is efficiently removed. Fine grained regolith from the planetary surface or an organic free reference material may serve as the powder used for cleaning. We present both analytical and experimental results for the contamination transfer fraction and the conditions required to clean the hardware prior to sensitive chemical analysis.
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Affiliation(s)
- M S Anderson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.
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19
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Gleeson DF, Pappalardo RT, Anderson MS, Grasby SE, Mielke RE, Wright KE, Templeton AS. Biosignature detection at an Arctic analog to Europa. Astrobiology 2012; 12:135-150. [PMID: 22283368 DOI: 10.1089/ast.2010.0579] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The compelling evidence for an ocean beneath the ice shell of Europa makes it a high priority for astrobiological investigations. Future missions to the icy surface of this moon will query the plausibly sulfur-rich materials for potential indications of the presence of life carried to the surface by mobile ice or partial melt. However, the potential for generation and preservation of biosignatures under cold, sulfur-rich conditions has not previously been investigated, as there have not been suitable environments on Earth to study. Here, we describe the characterization of a range of biosignatures within potentially analogous sulfur deposits from the surface of an Arctic glacier at Borup Fiord Pass to evaluate whether evidence for microbial activities is produced and preserved within these deposits. Optical and electron microscopy revealed microorganisms and extracellular materials. Elemental sulfur (S⁰), the dominant mineralogy within field samples, is present as rhombic and needle-shaped mineral grains and spherical mineral aggregates, commonly observed in association with extracellular polymeric substances. Orthorhombic α-sulfur represents the stable form of S⁰, whereas the monoclinic (needle-shaped) γ-sulfur form rosickyite is metastable and has previously been associated with sulfide-oxidizing microbial communities. Scanning transmission electron microscopy showed mineral deposition on cellular and extracellular materials in the form of submicron-sized, needle-shaped crystals. X-ray diffraction measurements supply supporting evidence for the presence of a minor component of rosickyite. Infrared spectroscopy revealed parts-per-million level organics in the Borup sulfur deposits and organic functional groups diagnostic of biomolecules such as proteins and fatty acids. Organic components are below the detection limit for Raman spectra, which were dominated by sulfur peaks. These combined investigations indicate that sulfur mineral deposits may contain identifiable biosignatures that can be stabilized and preserved under low-temperature conditions. Borup Fiord Pass represents a useful testing ground for instruments and techniques relevant to future astrobiological exploration at Europa.
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Affiliation(s)
- Damhnait F Gleeson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA.
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20
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Spector ND, Mann KJ, Anderson MS, Narayan AP, McGregor R. Facilitated peer group mentoring: a case study of creating leadership skills among the associate program directors of the APPD. Acad Pediatr 2010; 10:161-4. [PMID: 20452565 DOI: 10.1016/j.acap.2010.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Nancy D Spector
- Department of Pediatrics, Drexel University College of Medicine, Philadelphia, Pa, USA.
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21
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Dominguez SR, Briese T, Palacios G, Hui J, Villari J, Kapoor V, Tokarz R, Glodé MP, Anderson MS, Robinson CC, Holmes KV, Lipkin WI. Multiplex MassTag-PCR for respiratory pathogens in pediatric nasopharyngeal washes negative by conventional diagnostic testing shows a high prevalence of viruses belonging to a newly recognized rhinovirus clade. J Clin Virol 2008; 43:219-22. [PMID: 18674964 PMCID: PMC2603178 DOI: 10.1016/j.jcv.2008.06.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 06/03/2008] [Accepted: 06/09/2008] [Indexed: 11/02/2022]
Abstract
BACKGROUND Respiratory infections are the most common infectious diseases in humans worldwide and are a leading cause of death in children less than 5 years of age. OBJECTIVES Identify candidate pathogens in pediatric patients with unexplained respiratory disease. STUDY DESIGN Forty-four nasopharyngeal washes collected during the 2004-2005 winter season from pediatric patients with respiratory illnesses that tested negative for 7 common respiratory pathogens by culture and direct immunofluorescence assays were analyzed by MassTag-PCR. To distinguish human enteroviruses (HEV) and rhinoviruses (HRV), samples positive for picornaviruses were further characterized by sequence analysis. RESULTS Candidate pathogens were detected by MassTag PCR in 27 of the 44 (61%) specimens that previously were rated negative. Sixteen of these 27 specimens (59%) contained picornaviruses; of these 9 (57%) contained RNA of a recently discovered clade of rhinoviruses. Bocaviruses were detected in three patients by RT-PCR. CONCLUSIONS Our study confirms that multiplex MassTag-PCR enhances the detection of pathogens in clinical specimens, and shows that previously unrecognized rhinoviruses, that potentially form a species HRV-C, may cause a significant amount of pediatric respiratory disease.
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Affiliation(s)
- Samuel R Dominguez
- Department of Pediatrics, The Children's Hospital, University of Colorado Denver School of Medicine, Aurora, CO, USA
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22
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Abstract
OBJECTIVES We conducted a case-control study to ascertain the clinical presentations, risk factors, and clinical outcomes of children who had Kawasaki disease and were admitted to the ICU of our children's hospital. METHODS We reviewed charts of all children who had a discharge diagnosis of Kawasaki disease and were admitted to the ICU from 1995 through 2007. For each patient, we identified 3 season-matched control subjects who had Kawasaki disease and were not admitted to the ICU. RESULTS We identified 423 patients with Kawasaki disease. Of those, 14 (3.3%) were admitted to the ICU and met our inclusion criteria. ICU admission diagnoses were most commonly toxic shock or septic shock. Thirteen (92.8%) of 14 patients who were admitted to the ICU met criteria for complete Kawasaki disease before treatment. There was no significant difference in age in ICU patients compared with season-matched control subjects with Kawasaki disease. ICU patients were significantly more likely to be female and to have higher band counts, lower platelet counts, lower albumin levels, and higher C-reactive protein values. Time from admission to treatment with intravenous immunoglobulin was delayed in ICU patients. ICU patients were more likely to have intravenous immunoglobulin-refractory disease and require therapy with a second dose of intravenous immunoglobulin, infliximab, or steroids. CONCLUSIONS We present a case-control study of patients who had Kawasaki disease and presented severely ill, in shock, and requiring admission to the ICU. These patients frequently were misdiagnosed because of failure to appreciate the full spectrum of disease severity seen in patients with Kawasaki disease. These patients' illnesses was often mistaken for toxic or septic shock, leading to a delay in treatment with intravenous immunoglobulin. Patients who have Kawasaki disease and are admitted to the ICU are at increased risk for intravenous immunoglobulin-refractory disease and may be at risk for development of more severe coronary artery disease.
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Affiliation(s)
- Samuel R Dominguez
- Department of Pediatrics, University of Colorado Denver School of Medicine, Denver, Colorado, USA.
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23
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Pérez-Vélez CM, Anderson MS, Robinson CC, McFarland EJ, Nix WA, Pallansch MA, Oberste MS, Glodé MP. Outbreak of Neurologic Enterovirus Type 71 Disease: A Diagnostic Challenge. Clin Infect Dis 2007; 45:950-7. [PMID: 17879907 DOI: 10.1086/521895] [Citation(s) in RCA: 154] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2007] [Accepted: 07/02/2007] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Similar to poliovirus, enterovirus type 71 (EV71) causes severe disease, including aseptic meningitis, encephalitis, acute flaccid paralysis, and acute cardiopulmonary dysfunction. Large epidemics of EV71 infection have been reported worldwide. METHODS After recognition of a cluster of cases of EV71 disease, we reviewed records of patients with EV71 disease who required hospitalization at The Children's Hospital in Denver, Colorado, from 2003 through 2005. The presence of enterovirus was detected by reverse-transcriptase polymerase chain reaction (PCR) and/or viral culture of specimens from multiple sources, and the virus was typed as EV71 using genetic sequencing. RESULTS Eight cases of EV71 disease were identified in both 2003 and 2005. Fifty-six percent of patients with EV71 disease were < or = 6 months of age (range, 4 weeks to 9 years). All 16 patients had EV71 central nervous system infection. Enterovirus PCR (EV-PCR) of cerebrospinal fluid specimens yielded positive results for only 5 (31.2%) of the 16 patients; all of these patients were < 4 months of age and had less severe disease. However, EV-PCR of upper respiratory tract specimens yielded positive results for 8 (100%) of 8 patients, and EV-PCR of lower gastrointestinal tract specimens yielded positive results for 7 (87.5%) of 8 patients. CONCLUSIONS An outbreak of neurologic EV71 disease occurred in Denver, Colorado, during 2003 and 2005. Likely, EV71 disease remains unrecognized in other parts of the United States, because EV-PCR of cerebrospinal fluid frequently yields negative results. EV-PCR of specimens from the respiratory and gastrointestinal tracts had higher diagnostic yields than did EV-PCR of cerebrospinal fluid. EV71 infection should be considered in young children presenting with aseptic meningitis, encephalitis, acute flaccid paralysis, or acute cardiopulmonary collapse. EV71 infection may be an underrecognized emerging disease in the United States.
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Affiliation(s)
- Carlos M Pérez-Vélez
- Department of Pediatrics, Section of Infectious Diseases, University of Colorado School of Medicine, and The Children's Hospital, Denver, Colorado 80218, USA.
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Dominguez SR, Anderson MS, Glodé MP, Robinson CC, Holmes KV. Blinded case-control study of the relationship between human coronavirus NL63 and Kawasaki syndrome. J Infect Dis 2006; 194:1697-701. [PMID: 17109341 PMCID: PMC7199878 DOI: 10.1086/509509] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2006] [Accepted: 06/30/2006] [Indexed: 11/21/2022] Open
Abstract
We conducted a blinded, case‐control, retrospective study in pediatric patients hospitalized at The Children’s Hospital, Denver, Colorado, to determine whether human coronavirus (HCoV)–NL63 infection is associated with Kawasaki syndrome (KS). Over the course of a 7‐month period, nasopharyngeal‐wash samples from 2 (7.7%) of 26 consecutive children with KS and 4 (7.7%) of 52 matched control subjects tested positive for HCoV‐NL63 by reverse transcription–polymerase chain reaction. These data suggest that, although HCoV‐NL63 was circulating in children in our community during the time of the study, the prevalence of infection with HCoV‐NL63 was not greater in patients with KS than in control subjects.
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Affiliation(s)
- Samuel R Dominguez
- Department of Pediatrics, The Children's Hospital, University of Colorado Health Science Center, Denver, CO, USA
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25
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Abstract
OBJECTIVE Most pediatric providers in Colorado are familiar with Kawasaki syndrome (KS). However, in a recent outbreak, 30% of cases were diagnosed after illness day 10. We hypothesized that these children saw providers who were not familiar with KS, were given antibiotics for other diagnoses that delayed identification, had access-to-care issues, or presented atypically. METHODS A retrospective chart review of 106 consecutive KS cases seen at the Children's Hospital in Denver during 1994-2000 was conducted. RESULTS Twenty-five of 106 children (23.6%) were diagnosed after day 10 of illness (delayed-diagnosis group [DDG]), and these 25 cases were compared with 81 cases diagnosed on or before day 10 (early-diagnosis group [EDG]). There were no differences between patients in the DDG and EDG in age, gender, number of visits, specialty of the primary care physician, time to the first medical visit, number of antibiotics received, coronary artery abnormalities, white blood cell count, or erythrocyte sedimentation rate. Patients in the DDG had significantly more days of fever, rash, red eyes, and oral changes. A platelet count of >450000/mm3 occurred more often in the DDG (56%) than the EDG (30%). After additional analysis, patients in the EDG had close clustering of symptom onset in the first few days of illness, but patients in the DDG had onset of symptoms scattered over 9 days. Patients in the DDG were 2.8 times more likely to have coronary artery aneurysms than patients in the EDG (DDG: 24%; EDG: 8.6%). CONCLUSIONS Diagnosis after the 10th day of illness was not linked to type of medical provider, number of antibiotics received, or number of physician visits. Patients in the DDG exhibited the typical features of KS, but the onset of their symptoms was dispersed over time as opposed to the close clustering of symptoms in the EDG. Because coronary artery aneurysms occurred significantly more often in the patients in the DDG, more education is needed to teach health care providers to have a high index of suspicion for KS in young children presenting with fever/rash illnesses.
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Affiliation(s)
- Marsha S Anderson
- Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado, USA.
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Anderson MS, Knall C, Thurman G, Mann D, Cusack N, Johnson GL, Ambruso DR. CP-64131, an aminobenzazepine with cytokine-like properties, stimulates human neutrophil functions through the p38-MAPK pathway. J Leukoc Biol 2004; 76:477-83. [PMID: 15155776 DOI: 10.1189/jlb.0903422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
CP-64131 (CP), an aminobenzazepine with cytokine-like, physiologic effects similar to granulocyte-colony stimulating factor (G-CSF) and granulocyte macrophage (GM)-CSF, increases the number of neutrophils and stimulates marrow recovery after doxirubicin ablation. CP can also function as a neutrophil agonist, like formyl-Met-leu-Phe (fMLP). In these studies, we show that CP is unique in that it stimulates the p38-mitogen-activated protein kinase (MAPK) pathway but not extracellular signal-regulated kinase (ERK)1/2 or c-jun N-terminal kinase MAPKs in human neutrophils from peripheral blood. This is in contrast to other neutrophil agonists such as fMLP, interleukin (IL)-8, or GM-CSF, which stimulate multiple MAPK pathways. Like fMLP and IL-8, CP is capable of stimulating superoxide (O2-) production, CD11b expression, and cell polarization in human neutrophils. CP-stimulated O2- production is completely dependent on p38-MAPK activation, as determined by sensitivity to the p38-MAPK inhibitor SB203580. In contrast, SB203580 only partially inhibits expression of CD11b and has no effect on cell polarization stimulated by CP. Therefore, CP treatment of neutrophils activates p38-MAPK but has effects independent of p38-MAPK activation. In human embryonic kidney 293 cells, a human kidney epithelial cell line CP stimulates p38-MAPK and modestly activates ERK1/2. The findings define CP as a novel, small molecule, which has little cellular toxicity in vitro. CP has the ability to activate specific MAPK pathways in different cell types and should prove to be an effective agonist in combination with inhibitors to study biological responses regulated by MAPKs.
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Treadwell TA, Maddox RA, Holman RC, Belay ED, Shahriari A, Anderson MS, Burns J, Glodé MP, Hoffman RE, Schonberger LB. Investigation of Kawasaki syndrome risk factors in Colorado. Pediatr Infect Dis J 2002; 21:976-8. [PMID: 12400527 DOI: 10.1097/00006454-200210000-00018] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Risk factors for Kawasaki syndrome (KS) were evaluated through a case-control study during an investigation of a KS cluster in Denver, CO. KS was associated with a humidifier in the child's room (odds ratio, 7.3; 95% confidence interval, 1.8 to 29.3) and possibly with an antecedent respiratory illness. The use of humidifiers should be further investigated as part of future studies of KS.
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Affiliation(s)
- Tracee A Treadwell
- Division of Viral and Rickettsial Diseases National Center for Infectious Diseases Centers for Disease Control and Prevention Atlanta, GA, USA
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Abstract
Peyronie's disease is a fibromatosis of the tunica albuginea. While trauma is believed to be the inciting event, the exact pathophysiology of this condition is unknown. In vitro analysis of cell biology can shed light on the pathogenesis of medical conditions and has been used for many decades as a research tool. We have established a cell culture model, which we have used to study the pathobiology of cells derived from Peyronie's disease plaque tissue. In 10 separate cell cultures derived from different individuals, these cells have demonstrated consistent phenotypic, genotypic and functional alterations. In neither of the control cell cultures, neonatal foreskin fibroblasts and normal tunica-derived fibroblasts have any of the above aberrations been demonstrated. The cells studied have been shown to be fibroblasts in nature with a sub-population of myofibroblasts present in culture. The Peyronie's disease plaque tissue-derived fibroblasts have demonstrated (i) consistent morphologic transformation (ii) increased S-phase on flow cytometry (iii) decreased dependence on culture medium (iv) cytogenic instability (v) excess production of fibrogenic cytokines and (vi) stabilization and dysfunctionalization of p53. Further refinement of this model and future analyses may permit an increased understanding of the pathogenesis of this condition and allow the development of therapeutic strategies.
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Affiliation(s)
- J P Mulhall
- Andrology Research Laboratory, Hines VA, Hines, Illinois, USA
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Stiffey-Wilusz J, Boice JA, Ronan J, Fletcher AM, Anderson MS. An ex vivo angiogenesis assay utilizing commercial porcine carotid artery: modification of the rat aortic ring assay. Angiogenesis 2002; 4:3-9. [PMID: 11824376 DOI: 10.1023/a:1016604327305] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The study of angiogenesis as a therapeutic target requires a reliable, physiologically relevant, and technically straightforward assay. An ex vivo assay bridges the gap between cell-based assays, which may not realistically represent the complex process of vessel sprouting, and in vivo assays, which are time consuming and expensive. Porcine carotid arteries provide an ideal tissue source for angiogenesis inhibitor screens due to their availability, physiological relevance and large size. 1.5 mm2 fragments of porcine carotid arteries were incubated in 48-well culture plates and sandwiched between two 100 microliters layers of Matrigel. Sprouting was observed from the explants and quantitated, using a digital imaging system, after two weeks of incubation. Histological analysis using Factor VIII-related antigen (von Willebrand Factor) as an endothelial cell-specific marker identified these sprouts, which were consistent with endothelial cell morphology, supporting the system as a model of angiogenesis. Accordingly, the angiogenesis inhibitors suramin, 2-methoxyestradiol, and the matrix metalloprotease inhibitor Batimastat were shown to completely inhibit sprouting at 50, 0.5, and 5.0 micrograms/ml, respectively and to have ED50 values of 23, 0.15, and 0.14 microgram/ml. This assay shows good reproducibility and eliminates animal to animal variation. The system should prove adaptable to other forms of angiogenic stimulation, ultimately making a variety of assays for angiogenesis available to laboratories of limited resources.
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Affiliation(s)
- J Stiffey-Wilusz
- Department of Endocrinology and Chemical Biology, Merck Research Laboratories, Rahway, New Jersey 07065, USA.
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Anderson MS. Kawasaki-like illness in Human Immuno-deficiency Virus-infected patients: is the etiologic agent the same as in pediatric Kawasaki disease? Clin Infect Dis 2002; 34:875-8. [PMID: 11850871 DOI: 10.1086/339069] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
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Anderson MS, Flowers-Ziegler J, Das UG, Hay WW, Devaskar SU. Glucose transporter protein responses to selective hyperglycemia or hyperinsulinemia in fetal sheep. Am J Physiol Regul Integr Comp Physiol 2001; 281:R1545-52. [PMID: 11641127 DOI: 10.1152/ajpregu.2001.281.5.r1545] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The acute effect of selective hyperglycemia or hyperinsulinemia on late gestation fetal ovine glucose transporter protein (GLUT-1, GLUT-3, and GLUT-4) concentrations was examined in insulin-insensitive (brain and liver) and insulin-sensitive (myocardium and fat) tissues at 1, 2.5, and 24 h. Hyperglycemia with euinsulinemia caused a two- to threefold increase in brain GLUT-3, liver GLUT-1, and myocardial GLUT-1 concentrations only at 1 h. There was no change in GLUT-4 protein amounts at any time during the selective hyperglycemia. In contrast, selective hyperinsulinemia with euglycemia led to an immediate and persistent twofold increase in liver GLUT-1, which lasted from 1 until 24 h with a concomitant decline in myocardial tissue GLUT-4 amounts, reaching statistical significance at 24 h. No other significant change in response to hyperinsulinemia was noted in any of the other isoforms in any of the other tissues. Simultaneous assessment of total fetal glucose utilization rate (GURf) during selective hyperglycemia demonstrated a transient 40% increase at 1 and 2.5 h, corresponding temporally with a transient increase in brain GLUT-3 and liver and myocardial GLUT-1 protein amounts. In contrast, selective hyperinsulinemia led to a sustained increase in GURf, corresponding temporally with the persistent increase in hepatic GLUT-1 concentrations. We conclude that excess substrate acutely increases GURf associated with an increase in various tissues of the transporter isoforms GLUT-1 and GLUT-3 that mediate fetal basal glucose transport without an effect on the GLUT-4 isoform that mediates insulin action. This contrasts with the tissue-specific effects of selective hyperinsulinemia with a sustained increase in GURf associated with a sustained increase in hepatic basal glucose transporter (GLUT-1) amounts and a myocardial-specific emergence of mild insulin resistance associated with a downregulation of GLUT-4.
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Affiliation(s)
- M S Anderson
- Division of Neonatology, Department of Pediatrics, University of Colorado, Denver, Colorado 80262, USA
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Anderson MS, He J, Flowers-Ziegler J, Devaskar SU, Hay WW. Effects of selective hyperglycemia and hyperinsulinemia on glucose transporters in fetal ovine skeletal muscle. Am J Physiol Regul Integr Comp Physiol 2001; 281:R1256-63. [PMID: 11557634 DOI: 10.1152/ajpregu.2001.281.4.r1256] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We measured net fetal glucose uptake rate from the placenta, shown previously to be equal to total fetal glucose utilization rate (GUR(f)) and proportional to fetal hindlimb skeletal muscle glucose utilization, under normal conditions and after 1, 2.5, and 24 h of selective hyperglycemia increasing G or selective hyperinsulinemia increasing I. We simultaneously measured the amount of Glut 1 and Glut 4 glucose transporter proteins in fetal sheep skeletal muscle. With increasing G , GUR(f) was increased approximately 40% at 1 and 2.5 h but returned to the control rate by 24 h. This transient increasing G -specific increasing GUR(f) was associated with increased plasma membrane-associated Glut 1 (4-fold) and intracellular Glut 4 (3-fold) protein beginning at 1 h. With increasing I, GUR(f) was increased approximately 70% at 1, 2.5, and 24 h. This more sustained increasing I-specific increasing GUR(f) was associated with a significant increase in Glut 4 protein (2-fold) at 2.5 h but no change in Glut 1 protein. These results show that increasing G and increasing I have independent effects on the amount of Glut 1 and Glut 4 glucose transporter proteins in ovine fetal skeletal muscle. These effects are time dependent and isoform specific and may contribute to increased glucose utilization in fetal skeletal muscle. The lack of a sustained temporal correlation between the increase in transporter proteins and glucose utilization rates indicates that subcellular localization and activity of a transporter or tissues other than the skeletal muscle contribute to net GUR(f).
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Affiliation(s)
- M S Anderson
- Perinatal Research Center and Section of Neonatology, Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado 80262, USA.
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Wang Z, Wan H, Anderson MS, Abdel-Rehim M, Blomberg LG. Separation of lidocaine and its metabolites by capillary electrophoresis using volatile aqueous and nonaqueous electrolyte systems. Electrophoresis 2001; 22:2495-502. [PMID: 11519953 DOI: 10.1002/1522-2683(200107)22:12<2495::aid-elps2495>3.0.co;2-i] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The separation of the basic drug lidocaine and six of its metabolites has been investigated both by using volatile aqueous electrolyte system, at low pH and by employing non-aqueous electrolyte systems. In aqueous systems, the best separation of the compounds under the investigated conditions was achieved by using the electrolyte 60 mM trifluoroacetic acid (TFA)/triethylamine (TEA) at pH 2.5 containing 15% methanol. With this electrolyte, all seven compounds were well separated with high efficiency and migration time repeatability. The separations with bare fused-silica capillaries and polyacrylamide-coated capillaries were compared with higher separation efficiency with the latter. On the other hand, near baseline separation of all the seven compounds was also obtained by employing the non-aqueous electrolyte, 40 mM ammonium acetate in methanol and TFA (99:1, v/v), with comparable migration time repeatability but lower separation efficiency relative to the aqueous system.
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Affiliation(s)
- Z Wang
- Department of Chemistry, Karlstad University, Sweden
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Stephens E, Thureen PJ, Goalstone ML, Anderson MS, Leitner JW, Hay WW, Draznin B. Fetal hyperinsulinemia increases farnesylation of p21 Ras in fetal tissues. Am J Physiol Endocrinol Metab 2001; 281:E217-23. [PMID: 11440896 DOI: 10.1152/ajpendo.2001.281.2.e217] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Even though the role of fetal hyperinsulinemia in the pathogenesis of fetal macrosomia in patients with overt diabetes and gestational diabetes mellitus seems plausible, the molecular mechanisms of action of hyperinsulinemia remain largely enigmatic. Recent indications that hyperinsulinemia "primes" various tissues to the mitogenic influence of growth factors by increasing the pool of prenylated Ras proteins prompted us to investigate the effect of fetal hyperinsulinemia on the activitiy of farnesyltransferase (FTase) and the amounts of farnesylated p21 Ras in fetal tissues in the ovine experimental model. Induction of fetal hyperinsulinemia by direct infusion of insulin into the fetus and by either fetal or maternal infusions of glucose resulted in significant increases in the activity of FTase and the amounts of farnesylated p21 Ras in fetal liver, skeletal muscle, fat, and white blood cells. An additional infusion of somatostatin into hyperglycemic fetuses blocked fetal hyperinsulinemia and completely prevented these increases, specifying insulin as the causative factor. We conclude that the ability of fetal hyperinsulinemia to increase the size of the pool of farnesylated p21 Ras may prime fetal tissues to the action of other growth factors and thereby constitute one mechanism by which fetal hyperinsulinemia could induce macrosomia in diabetic pregnancies.
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Affiliation(s)
- E Stephens
- Veterans Affairs Research Service, Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado 80220, USA
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Abstract
Doctoral students receive many kinds of assistance from faculty members, but much of this support falls short of mentoring. This paper takes the perspective that it is more important to find out what kinds of help students receive from faculty than to assume that students are taken care of by mentors, as distinct from advisors or role models. The findings here are based on both survey and interview data collected through the Acadia Institute's project on Professional Values and Ethical Issues in the Graduate Education of Scientists and Engineers. The paper describes various kinds of assistance that students receive (or do not receive) from faculty members in their roles as teacher/coach, sponsor, and counselor, It concludes with a section on advisors assigned to doctoral students, notably the extent of their contact with and influence on students.
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Affiliation(s)
- M S Anderson
- 330 Wulling Hall, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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Abstract
OBJECTIVE To report a case of a clinically occult testicular tumor causing gynecomastia and to alert physicians to the importance of use of testicular ultrasonography in patients with progressive gynecomastia despite normal findings on testicular examination. METHODS We present a detailed case, including results of clinical, laboratory, and radiologic assessment, of a man with hyperprolactinemia and gynecomastia. RESULTS A 36-year-old man with progressive gynecomastia was referred to our clinic because of an increased serum prolactin level. Subsequent clinical investigation revealed no evidence of hypogonadism and several possible causes of the gynecomastia. Because of the patient's age and progressive symptoms, testicular ultrasonography was performed despite normal findings on testicular examination. This ultrasound study showed a right testicular mass, which proved to be a Leydig cell tumor. The patient was referred for definitive therapy with orchiectomy. Follow-up studies showed resolution of the gynecomastia and substantial decreases in prolactin and estradiol levels. CONCLUSION Although gynecomastia is a relatively common disorder with a benign cause in most cases, physicians should be aware that normal findings on testicular examination do not completely rule out the possibility of a testicular tumor as the cause. Because of the potentially high morbidity of testicular tumors and their known association with gynecomastia, early performance of testicular ultrasonography in a patient with gynecomastia of unknown cause is advised.
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Affiliation(s)
- M S Anderson
- Neuroendocrine Unit and Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, USA
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Anderson MS, Burns J, Treadwell TA, Pietra BA, Glodé MP. Erythrocyte sedimentation rate and C-reactive protein discrepancy and high prevalence of coronary artery abnormalities in Kawasaki disease. Pediatr Infect Dis J 2001; 20:698-702. [PMID: 11465843 DOI: 10.1097/00006454-200107000-00011] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND An outbreak of Kawasaki disease (KD) in Colorado between November, 1997, and June, 1998, provided the opportunity to study inflammatory indices and coronary artery abnormalities. METHODS Medical records of the 33 patients diagnosed with KD at The Children's Hospital during the outbreak were reviewed. Demographic and clinical information, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and echocardiogram results were recorded. Traditional abnormalities (dilatation, aneurysm, ectasia), as well as "prominence" of the coronary arteries were noted. RESULTS Twenty-five patients had CRP and ESR performed on the day of admission; 11 of 25 (44%) had a discrepancy between the height of the ESR and CRP values (high ESR and low CRP or low ESR and high CRP). The mean CRP was higher in patients who presented in <10 days than in patients who presented in > or =10 days: 13.9 mg/dl vs. 5.2 mg/dl (P = 0.01). The ESR value did not correlate with the day of illness. Age, gender or presence of coronary artery abnormalities did not correlate with the height of CRP or ESR elevation. Thirty percent of patients had at least one abnormality on their initial echocardiogram (dilatation, aneurysm, ectasia). An additional 24% of patients displayed prominence as the only finding on their initial echocardiogram. Of the 33 patients 7 (21.2%) had coronary artery aneurysms. CONCLUSIONS Many patients with KD have discrepancies in the degree of elevation of CRP and ESR. Physicians should consider obtaining both tests in patients with KD. This outbreak was associated with a high degree of coronary artery abnormalities. The finding of coronary artery prominence is an observation that deserves further study.
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Affiliation(s)
- M S Anderson
- University of Colorado Health Sciences Center, Children's Hospital, Denver, USA
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Azzolina BA, Yuan X, Anderson MS, El-Sherbeini M. The cell wall and cell division gene cluster in the Mra operon of Pseudomonas aeruginosa: cloning, production, and purification of active enzymes. Protein Expr Purif 2001; 21:393-400. [PMID: 11281713 DOI: 10.1006/prep.2001.1390] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have cloned the Pseudomonas aeruginosa cell wall biosynthesis and cell division gene cluster that corresponds to the mra operon in the 2-min region of the Escherichia coli chromosome. The organization of the two chromosomal regions in P. aeruginosa and E. coli is remarkably similar with the following gene order: pbp3/pbpB, murE, murF, mraY, murD, ftsW, murG, murC, ddlB, ftsQ, ftsA, ftsZ, and envA/LpxC. All of the above P. aeruginosa genes are transcribed from the same strand of DNA with very small, if any, intragenic regions, indicating that these genes may constitute a single operon. All five amino acid ligases, MurC, MurD, MurE, MurF, and DdlB, in addition to MurG and MraY were cloned in expression vectors. The four recombinant P. aeruginosa Mur ligases, MurC, MurD, MurE, and MurF were overproduced in E. coli and purified as active enzymes.
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Affiliation(s)
- B A Azzolina
- Department of Biochemistry, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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Yan Y, Munshi S, Leiting B, Anderson MS, Chrzas J, Chen Z. Crystal structure of Escherichia coli UDPMurNAc-tripeptide d-alanyl-d-alanine-adding enzyme (MurF) at 2.3 A resolution. J Mol Biol 2000; 304:435-45. [PMID: 11090285 DOI: 10.1006/jmbi.2000.4215] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
MurF is required to catalyze the final step in the synthesis of the cytoplasmic precursor of the bacterial cell wall peptidoglycan, rendering it an attractive target for antibacterial drug development. The crystal structure of the MurF apo-enzyme has been determined using the multiwavelength anomalous dispersion method and refined to 2.3 A resolution. It contains three consecutive open alpha/beta-sheet domains. In comparison with the complex crystal structures of MurD and its substrates, The topology of the N-terminal domain of MurF is unique, while its central and C-terminal domains exhibit similar mononucleotide and dinucleotide-binding folds, respectively. The apo-enzyme of MurF crystal structure reveals an open conformation with the three domains juxtaposed in a crescent-like arrangement creating a wide-open space where substrates are expected to bind. As such, catalysis is not feasible and significant domain closure is expected upon substrate binding.
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Affiliation(s)
- Y Yan
- Department of Structural Biology, West Point, PA, 19486, USA.
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Anderson MS, Eveland SS, Price NP. Conserved cytoplasmic motifs that distinguish sub-groups of the polyprenol phosphate:N-acetylhexosamine-1-phosphate transferase family. FEMS Microbiol Lett 2000; 191:169-75. [PMID: 11024259 DOI: 10.1111/j.1574-6968.2000.tb09335.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
WecA, MraY and WbcO are conserved members of the polyprenol phosphate:N-acetylhexosamine-1-phosphate transferase family involved in the assembly of bacterial cell walls, and catalyze reactions involving a membrane-associated polyprenol phosphate acceptor substrate and a cytoplasmically located UDP-D-amino sugar donor. MraY, WbcO and WecA purportedly utilize different UDP-sugars, although the molecular basis of this specificity is largely unknown. However, domain variations involved in specificity are predicted to occur on the cytoplasmic side of the membrane, adjacent to conserved domains involved in the mechanistic activity, and with access to the cytoplasmically located sugar nucleotides. Conserved C-terminal domains have been identified that satisfy these criteria. Topological analyses indicate that they form the highly basic, fifth cytoplasmic loop between transmembrane regions IX and X. Four diverse loops are apparent, for MraY, WecA, WbcO and RgpG, that uniquely characterize these sub-groups of the transferase family, and a correlation is evident with the known or implied UDP-sugar specificity.
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Affiliation(s)
- M S Anderson
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA.
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Abstract
Data from two national surveys of 4,000 faculty and doctoral students in chemistry, civil engineering, microbiology and sociology indicate that both faculty and students subscribe strongly to traditional norms but are more likely to see alternative counternorms enacted in their departments. They also show significant effects of departmental climate on normative orientations and suggest that many researchers express some degree of ambivalence about traditional norms.
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Affiliation(s)
- M S Anderson
- University of Minnesota, 330 Wulling Hall, Minneapolis, MN 55455, USA.
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Abstract
Peyronie's disease is a fibromatosis of the tunica albuginea which affects up to 2% of men. Plaque development is believed to result, at least in part, from fibroblast proliferation and excess collagen deposition. Numerous oral and intralesional therapies have been used, including verapamil, colchicine and steroids. The purpose of this study was to investigate the in vitro effects of prostaglandin-E1 (PGE1), verapamil and colchicine on the proliferation rates of fibroblasts derived from Peyronie's disease tissue. Using tissue culture, multiple cell lines comprising fibroblasts from Peyronie's plaque, normal tunica and foreskin were established. Cells of low passage were removed from the parent culture and incubated with varying concentrations of PGE1 (0.1-10 mg/ml), verapamil (10-1000 mg/ml), and colchine (2.5 mg/ml). Proliferation was assessed at 48, 72 and 96 hours using the Vybrant MTT cell proliferation and then compared to control cells. Six plaque lines and 5 normal tunical cell lines were established. These cell lines exhibited excellent linear growth in culture media alone. Co-culture wih PGE1 resulted in no significant inhibition at 0.1 and 1 mg/ml, but a mean inhibition of 60.6+/-11.5% at a concenrtation of 10 mg/ml was noted. Similar inhibition was noted with verapamil at 100 and 1000 mg/ml with a mean inhibition of 65.2+/-10.6%. Colchicine resulted in a mean inhibition of 28% at a concentration of 2.5 mg/ml. Maximum inhibition occurred at 96 hours in all cases. There was no statisitically significant difference in proliferation rates between plaque and normal tunical cell lines. We have developed an in vitro model to assess the effects of biologically active agents on the growth of fibroblasts derived from Peyronie's disease tissue. Our data suggests that PGE1, verapamil, and colchicine inhibit in vitro proliferation of fibroblasts at specific concentrations. Refinement and application of this knowledge may allow the development of useful pharmacologic strategies for men with PD.
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Affiliation(s)
- M S Anderson
- Urology Research Laboratory, Hines VA, Hines, IL 60153, USA
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43
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Abstract
A comparison of laboratory spectra with Galileo data indicates that hydrated sulfuric acid is present and is a major component of Europa's surface. In addition, this moon's visually dark surface material, which spatially correlates with the sulfuric acid concentration, is identified as radiolytically altered sulfur polymers. Radiolysis of the surface by magnetospheric plasma bombardment continuously cycles sulfur between three forms: sulfuric acid, sulfur dioxide, and sulfur polymers, with sulfuric acid being about 50 times as abundant as the other forms. Enhanced sulfuric acid concentrations are found in Europa's geologically young terrains, suggesting that low-temperature, liquid sulfuric acid may influence geological processes.
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Affiliation(s)
- R W Carlson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
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Affiliation(s)
- M S Anderson
- Department of Pediatrics, The Children's Hospital and University of Colorado Health Sciences Center, Denver, USA
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45
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Affiliation(s)
- M S Anderson
- Department of Pediatrics, Children's Hospital, University of Colorado Health Sciences Center, Denver, USA
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46
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Carlson RW, Anderson MS, Johnson RE, Smythe WD, Hendrix AR, Barth CA, Soderblom LA, Hansen GB, McCord TB, Dalton JB, Clark RN, Shirley JH, Ocampo AC, Matson DL. Hydrogen peroxide on the surface of Europa. Science 1999; 283:2062-4. [PMID: 10092224 DOI: 10.1126/science.283.5410.2062] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Spatially resolved infrared and ultraviolet wavelength spectra of Europa's leading, anti-jovian quadrant observed from the Galileo spacecraft show absorption features resulting from hydrogen peroxide. Comparisons with laboratory measurements indicate surface hydrogen peroxide concentrations of about 0.13 percent, by number, relative to water ice. The inferred abundance is consistent with radiolytic production of hydrogen peroxide by intense energetic particle bombardment and demonstrates that Europa's surface chemistry is dominated by radiolysis.
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Affiliation(s)
- R W Carlson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
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47
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Chen MH, Steiner MG, de Laszlo SE, Patchett AA, Anderson MS, Hyland SA, Onishi HR, Silver LL, Raetz CR. Carbohydroxamido-oxazolidines: antibacterial agents that target lipid A biosynthesis. Bioorg Med Chem Lett 1999; 9:313-8. [PMID: 10091675 DOI: 10.1016/s0960-894x(98)00749-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A series of carbohydroxamido-oxazolidine inhibitors of UDP-3-O-[R-3-hydroxymyristoyl]-GlcNAc deacetylase, the enzyme responsible for the second step in lipid A biosynthesis, was identified. The most potent analog L-161,240 showed an IC50 = 30 nM in the DEACET assay and displayed an MIC of 1-3 microg/mL against wild-type E. coli.
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Affiliation(s)
- M H Chen
- Department of Medicinal Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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48
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Taylor JR, Anderson MS, Bunton PH. High-speed tilt mirror for image stabilization. Appl Opt 1999; 38:219-223. [PMID: 18305606 DOI: 10.1364/ao.38.000219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A magnetostrictively driven tilt-mirror mount for image stabilization of NASA's Marshall Space Flight Center's Experimental Vector Magnetograph has been designed, built, and tested. A simple improvement in the mounting technique of the actuator resulted in a factor of 3 increase in the lowest resonant frequency of the device. The tilt-mirror device was built, and the lowest structural resonant frequency was experimentally found to be 603 Hz.
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Affiliation(s)
- J R Taylor
- Department of Physics, Austin Peay State University, PO Box 4608, Clarksville, Tennessee 37044-0002, USA.
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49
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Abstract
UDP-GlcN[1-14C]Ac was synthesized in a single enzymatic reaction from [1-14C]acetate and commercially available precursors on both a microcurie (micromole) and a millicurie (millimole) scale. The reaction was catalyzed by the action of acetyl coenzyme A synthetase, inorganic pyrophosphatase, and the bifunctional Escherichia coli GlmU protein. Within 2 h 86 to 94% reaction is attained, and it approaches 99% completion overnight. GlmU protein was prepared in the form of a fusion suitable for nickel chelate affinity chromatography. Several methods were developed for rapid purification of UDP-GlcN[1-14C]Ac: an HPLC method handled micromole (microcurie) loads. Alternatively, ion exchange chromatography over DOWEX AG1 X-2 using a batch elution procedure was compatible with millimole (millicurie) amounts of radiolabel and yielded both chemically and radiochemically homogeneous UDP-GlcN[1-14C]Ac. These methods allow laboratories to quickly produce and purify microcurie to millicurie quantities of N-acetyl-labeled UDP-GlcNAc by a choice of methods from relatively inexpensive precursors.
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Affiliation(s)
- B Leiting
- Department of Enzymology, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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Eveland SS, Pompliano DL, Anderson MS. Conditionally lethal Escherichia coli murein mutants contain point defects that map to regions conserved among murein and folyl poly-gamma-glutamate ligases: identification of a ligase superfamily. Biochemistry 1997; 36:6223-9. [PMID: 9166795 DOI: 10.1021/bi9701078] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Bacterial peptidoglycan biosynthesis includes four enzymatic reactions in which successive amino acid residues are ligated to uridine diphospho-N-acetylmuramic acid (UDP-MurNAc). By comparing the amino acid sequences of MurC, -D, -E, and -F proteins from various bacterial genera, four regions of homology were identified. A profile search of Swissprot for related sequences revealed that these regional similarities were present in the folyl-gamma-polyglutamate ligases. These sequence homologies appear to track with catalytic function: both enzyme families proceed through an ordered kinetic mechanism and form product via an acyl phosphate intermediate. Two highly conserved residues in region II were examined through site-directed mutagenesis of the murein D-alanyl-D-alanine-adding enzyme from Escherichia coli (murF; E158 and H188). All mutations were highly detrimental to activity with enzyme specific activity reductions of 200-4500-fold, validating the critical nature of these residues. DNA sequence analysis from three E. coli mutants harboring the murC3 (G344D), murE1 (G344K, A495S), and murF2 (A288T) mutations revealed the presence of point mutation(s) closely associated with the fourth of these aligned regions. The murF2 allele, expressed and purified as a glutathione S-transferase::MurF2 fusion, was 181-fold less catalytically active at 30 degrees C and was further reduced at the nonpermissive temperature (42 degrees C). Thus the murF2 temperature-sensitive phenotype arises from a point mutation within a highly conserved region within this protein family. These data argue that these proteins comprise a superfamily of three substrate amide ligases that share significant structural and catalytic homologies.
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Affiliation(s)
- S S Eveland
- Department of Enzymology, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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