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Griffiths M, Hatabah D, Sullivan P, Mantus G, Sanchez T, Zlotorzynska M, Heilman S, Camacho-Gonzalez A, Leake D, Korman R, Le M, Suthara M, Wrammert J, Vos MB, Morris CR. Incidence of SARS-CoV-2 Seropositivity in Pediatric Healthcare Workers Prior to Widespread Vaccination: A Five-month Longitudinal Cohort Study. Int J Infect Dis 2024:107064. [PMID: 38641316 DOI: 10.1016/j.ijid.2024.107064] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 03/28/2024] [Accepted: 04/16/2024] [Indexed: 04/21/2024] Open
Abstract
OBJECTIVES Determine SARS-CoV-2 IgG antibody incidence over time in unvaccinated pediatric healthcare workers (pHCWs). DESIGN Prospective longitudinal cohort of unvaccinated pHCWs measuring incidence of new infection after initial prevalence was established at 4.1% with seropositive predominance in emergency department (ED)-based pHCWs. Serum samples were collected at follow-up visits to detect new SARS-CoV-2 seropositivity. Univariate analysis was performed to estimate different incidence rates between participant demographics, job, employment location and community risk factors. Anxiety levels about COVID-19 were collected. SARS-CoV-2 antibody decay post-infection, and neutralization antibodies were evaluated. Log-linear Poisson regression models were used to estimate incidence. RESULTS Of 642 initially enrolled, 390 pHCWs presented for at least one follow-up serology test after baseline analysis. Incidence of SARS-CoV-2 seropositivity was 8.2%. The seropositive cohort, like the negative one consisted mainly of females in non-ED settings and non-physician roles. There were no statistically significant differences in incidence across variables. Seropositive participants dropped antibody titers by 50% at 3 months. Neutralization antibodies correlated to SARs-CoV-2 binding antibodies (r=0.43,p<0.0001). CONCLUSION Incidence of seropositivity was 8.2%. Although seropositivity was higher among ED staff during early stages of the pandemic, this difference declined over time, likely due to universal adoption of personal protective equipment (PPE).
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Affiliation(s)
- Mark Griffiths
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Dunia Hatabah
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Patrick Sullivan
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Grace Mantus
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Travis Sanchez
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Maria Zlotorzynska
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Stacy Heilman
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Andres Camacho-Gonzalez
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Children's Healthcare of Atlanta, Atlanta, GA, United States; Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, United States
| | - Deborah Leake
- Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Rawan Korman
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Mimi Le
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Center for Clinical and Translational Research, of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, United States
| | - Mehul Suthara
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Jens Wrammert
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, United States
| | - Miriam B Vos
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Children's Healthcare of Atlanta, Atlanta, GA, United States; Center for Clinical and Translational Research, of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, United States
| | - Claudia R Morris
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Children's Healthcare of Atlanta, Atlanta, GA, United States; Center for Clinical and Translational Research, of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, United States.
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Bakshi N, Liu Z, Gillespie S, Keesari R, Leake D, Khemani K, Kumari P, Rees CA, Dampier C, Morris CR. Patient-reported outcomes in children with sickle cell disease at presentation for an acute pain episode. Blood Adv 2023; 7:5103-5107. [PMID: 36322873 PMCID: PMC10477437 DOI: 10.1182/bloodadvances.2021006794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 09/14/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023] Open
Affiliation(s)
- Nitya Bakshi
- Division of Pediatric Hematology-Oncology-Blood and Marrow Transplant, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA
- Aflac Cancer and Blood Disorders, Children's Healthcare of Atlanta, Atlanta, GA
| | - Zihao Liu
- Rollins School of Public Health, Emory University, Atlanta, GA
| | | | - Rohali Keesari
- Pediatric Biostatistics Core, Emory University, Atlanta, GA
| | | | - Kirshma Khemani
- Division of Pediatric Hematology-Oncology-Blood and Marrow Transplant, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA
- Aflac Cancer and Blood Disorders, Children's Healthcare of Atlanta, Atlanta, GA
| | - Polly Kumari
- Division of Pediatric Emergency Medicine, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA
| | - Chris A. Rees
- Children’s Healthcare of Atlanta, Atlanta, GA
- Division of Pediatric Emergency Medicine, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA
| | - Carlton Dampier
- Division of Pediatric Hematology-Oncology-Blood and Marrow Transplant, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA
- Aflac Cancer and Blood Disorders, Children's Healthcare of Atlanta, Atlanta, GA
| | - Claudia R. Morris
- Children’s Healthcare of Atlanta, Atlanta, GA
- Division of Pediatric Emergency Medicine, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA
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3
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Rees CA, Brousseau DC, Cohen DM, Villella A, Dampier C, Brown K, Campbell A, Chumpitazi CE, Airewele G, Chang T, Denton C, Ellison A, Thompson A, Ahmad F, Bakshi N, Coleman KD, Leibovich S, Leake D, Hatabah D, Wilkinson H, Robinson M, Casper TC, Vichinsky E, Morris CR. Sickle Cell Disease Treatment with Arginine Therapy (STArT): study protocol for a phase 3 randomized controlled trial. Trials 2023; 24:538. [PMID: 37587492 PMCID: PMC10433602 DOI: 10.1186/s13063-023-07538-z] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 07/25/2023] [Indexed: 08/18/2023] Open
Abstract
BACKGROUND Despite substantial illness burden and healthcare utilization conferred by pain from vaso-occlusive episodes (VOE) in children with sickle cell disease (SCD), disease-modifying therapies to effectively treat SCD-VOE are lacking. The aim of the Sickle Cell Disease Treatment with Arginine Therapy (STArT) Trial is to provide definitive evidence regarding the efficacy of intravenous arginine as a treatment for acute SCD-VOE among children, adolescents, and young adults. METHODS STArT is a double-blind, placebo-controlled, randomized, phase 3, multicenter trial of intravenous arginine therapy in 360 children, adolescents, and young adults who present with SCD-VOE. The STArT Trial is being conducted at 10 sites in the USA through the Pediatric Emergency Care Applied Research Network (PECARN). Enrollment began in 2021 and will continue for 5 years. Within 12 h of receiving their first dose of intravenous opioids, enrolled participants are randomized 1:1 to receive either (1) a one-time loading dose of L-arginine (200 mg/kg with a maximum of 20 g) administered intravenously followed by a standard dose of 100 mg/kg (maximum 10 g) three times a day or (2) a one-time placebo loading dose of normal saline followed by normal saline three times per day at equivalent volumes and duration as the study drug. Participants, research staff, and investigators are blinded to the participant's randomization. All clinical care is provided in accordance with the institution-specific standard of care for SCD-VOE based on the 2014 National Heart, Lung, and Blood Institute guidelines. The primary outcome is time to SCD-VOE pain crisis resolution, defined as the time (in hours) from study drug delivery to the last dose of parenteral opioid delivery. Secondary outcomes include total parental opioid use and patient-reported outcomes. In addition, the trial will characterize alterations in the arginine metabolome and mitochondrial function in children with SCD-VOE. DISCUSSION Building on the foundation of established relationships between emergency medicine providers and hematologists in a multicenter research network to ensure adequate participant accrual, the STArT Trial will provide definitive information about the efficacy of intravenous arginine for the treatment of SCD-VOE for children. TRIAL REGISTRATION The STArT Trial was registered in ClinicalTrials.gov on April 9, 2021, and enrollment began on June 21, 2021 (NCT04839354).
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Affiliation(s)
- Chris A Rees
- Department of Pediatrics, Division of Pediatric Emergency Medicine, Emory University School of Medicine, 1760 Haygood Drive NE, Atlanta, GA, W45830322, USA
- Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - David C Brousseau
- Department of Pediatrics, Nemours Children's Health Delaware and the Sidney Kimmel Medical College, Thomas Jefferson University, Wilmington, DE, USA
| | | | | | - Carlton Dampier
- Department of Pediatrics, Division of Pediatric Emergency Medicine, Emory University School of Medicine, 1760 Haygood Drive NE, Atlanta, GA, W45830322, USA
- Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - Kathleen Brown
- Children's National Hospital, The George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - Andrew Campbell
- Children's National Hospital, The George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | | | - Gladstone Airewele
- Texas Children's Hospital and Baylor College of Medicine, Houston, TX, USA
| | - Todd Chang
- Children's Hospital Los Angeles and Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
| | - Christopher Denton
- Children's Hospital Los Angeles and Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA
| | - Angela Ellison
- Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | | | - Fahd Ahmad
- Washington University in St. Louis, St. Louis, MO, USA
| | - Nitya Bakshi
- Division of Pediatric Hematology/Oncology/BMT, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, USA
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, GA, USA
| | - Keli D Coleman
- Medical College of Wisconsin and Children's Wisconsin, Milwaukee, WI, USA
| | | | | | - Dunia Hatabah
- Department of Pediatrics, Division of Pediatric Emergency Medicine, Emory University School of Medicine, 1760 Haygood Drive NE, Atlanta, GA, W45830322, USA
| | | | | | | | - Elliott Vichinsky
- Center for Maternal-Fetal Precision Medicine, University of California, San Francisco, CA, USA
- Department of Pediatrics, UCSF-Benioff Children's Hospital-Oakland, Oakland, CA, USA
| | - Claudia R Morris
- Department of Pediatrics, Division of Pediatric Emergency Medicine, Emory University School of Medicine, 1760 Haygood Drive NE, Atlanta, GA, W45830322, USA.
- Children's Healthcare of Atlanta, Atlanta, GA, USA.
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4
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Reyes LZ, Figueroa J, Leake D, Khemani K, Kumari P, Bakshi N, Lane PA, Dampier C, Morris CR. Safety of intravenous arginine therapy in children with sickle cell disease hospitalized for vaso-occlusive pain: A randomized placebo-controlled trial in progress. Am J Hematol 2022; 97:E21-E24. [PMID: 34724240 PMCID: PMC8722015 DOI: 10.1002/ajh.26396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/25/2021] [Accepted: 10/28/2021] [Indexed: 01/03/2023]
Affiliation(s)
- Loretta Z. Reyes
- Department of Pediatrics, Emory University School of
Medicine, Atlanta, Georgia, USA,Children’s Healthcare of Atlanta, Atlanta, Georgia,
USA
| | - Janet Figueroa
- Department of Pediatrics, Emory University School of
Medicine, Atlanta, Georgia, USA,Children’s Healthcare of Atlanta, Atlanta, Georgia,
USA
| | - Deborah Leake
- Children’s Healthcare of Atlanta, Atlanta, Georgia,
USA
| | - Kirshma Khemani
- Department of Pediatrics, Emory University School of
Medicine, Atlanta, Georgia, USA,Children’s Healthcare of Atlanta, Atlanta, Georgia,
USA
| | - Polly Kumari
- Department of Pediatrics, Emory University School of
Medicine, Atlanta, Georgia, USA,Children’s Healthcare of Atlanta, Atlanta, Georgia,
USA
| | - Nitya Bakshi
- Department of Pediatrics, Emory University School of
Medicine, Atlanta, Georgia, USA,Children’s Healthcare of Atlanta, Atlanta, Georgia,
USA
| | - Peter A. Lane
- Department of Pediatrics, Emory University School of
Medicine, Atlanta, Georgia, USA,Children’s Healthcare of Atlanta, Atlanta, Georgia,
USA
| | - Carlton Dampier
- Department of Pediatrics, Emory University School of
Medicine, Atlanta, Georgia, USA,Children’s Healthcare of Atlanta, Atlanta, Georgia,
USA
| | - Claudia R. Morris
- Department of Pediatrics, Emory University School of
Medicine, Atlanta, Georgia, USA,Children’s Healthcare of Atlanta, Atlanta, Georgia,
USA
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5
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Ahmad F, Mitchell R, Houben T, Palo A, Yadati T, Parnell A, Patel K, Shiri-Sverdlov R, Leake D. Cysteamine (A lysosomotropic antioxidant) causes regression of atherosclerosis and improves liver and muscle function in LDL receptor deficient mice. Atherosclerosis 2021. [DOI: 10.1016/j.atherosclerosis.2021.06.299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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6
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Morris CR, Sullivan P, Mantus G, Sanchez T, Zlotorzynska M, Hanberry B, Iyer S, Heilman S, Camacho-Gonzalez A, Figueroa J, Manoranjithan S, Leake D, Mendis R, Cleeton R, Chen C, Krieger R, Bush P, Hughes T, Little WK, Suthar MS, Wrammert J, Vos MB. Prevalence of SARS-CoV-2 antibodies in pediatric healthcare workers. Int J Infect Dis 2021; 105:474-481. [PMID: 33722686 PMCID: PMC7952267 DOI: 10.1016/j.ijid.2021.03.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 02/28/2021] [Accepted: 03/08/2021] [Indexed: 01/08/2023] Open
Abstract
Objectives To determine SARS-CoV-2-antibody prevalence in pediatric healthcare workers (pHCWs). Design Baseline prevalence of anti-SARS-CoV-2-IgG was assessed in a prospective cohort study from a large pediatric healthcare facility. Prior SARS-CoV-2 testing history, potential risk factors and anxiety level about COVID-19 were determined. Prevalence difference between emergency department (ED)-based and non-ED-pHCWs was modeled controlling for those covariates. Chi-square test-for-trend was used to examine prevalence by month of enrollment. Results Most of 642 pHCWs enrolled were 31-40years, female and had no comorbidities. Half had children in their home, 49% had traveled, 42% reported an illness since January, 31% had a known COVID-19 exposure, and 8% had SARS-CoV-2 PCR testing. High COVID-19 pandemic anxiety was reported by 71%. Anti-SARS-CoV-2-IgG prevalence was 4.1%; 8.4% among ED versus 2.0% among non-ED pHCWs (p < 0.001). ED-work location and known COVID-19 exposure were independent risk factors. 31% of antibody-positive pHCWs reported no symptoms. Prevalence significantly (p < 0.001) increased from 3.0% in April–June to 12.7% in July–August. Conclusions Anti-SARS-CoV-2-IgG prevalence was low in pHCWs but increased rapidly over time. Both working in the ED and exposure to a COVID-19-positive contact were associated with antibody-seropositivity. Ongoing universal PPE utilization is essential. These data may guide vaccination policies to protect front-line workers.
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Affiliation(s)
- Claudia R Morris
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Children's Healthcare of Atlanta, Atlanta, GA, United States; Center for Clinical and Translational Research, of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, United States.
| | - Patrick Sullivan
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Grace Mantus
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Travis Sanchez
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Maria Zlotorzynska
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA, United States
| | - Bradley Hanberry
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Srikant Iyer
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Stacy Heilman
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Andres Camacho-Gonzalez
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Children's Healthcare of Atlanta, Atlanta, GA, United States; Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, United States
| | - Janet Figueroa
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | | | - Deborah Leake
- Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Reshika Mendis
- Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Rebecca Cleeton
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Christie Chen
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Rachel Krieger
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Patricia Bush
- Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Tiffany Hughes
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States
| | - Wendalyn K Little
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Children's Healthcare of Atlanta, Atlanta, GA, United States
| | - Mehul S Suthar
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, United States
| | - Jens Wrammert
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, United States
| | - Miriam B Vos
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA, United States; Children's Healthcare of Atlanta, Atlanta, GA, United States; Center for Clinical and Translational Research, of Children's Healthcare of Atlanta and Emory University, Atlanta, GA, United States
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Abstract
AIMS The lifestyle and physical activity (PA) habits of young people play a key role in the prevention of cardiovascular and metabolic diseases at older ages. The current generation of biological science students at university holds promise for better future medicine and medical technology. However, their physical fitness and lifestyle are often ignored. METHODS Lifestyle, PAs and common risk factors for cardiovascular disease before, and at, university were collected from 408 students using self-completed, anonymous surveys between the academic years of 2017 and 2019 from the School of Biological Sciences, University of Reading. Statistical analysis was performed using SAS® 9.4 software. RESULTS Among the 408 participants, 134 were male and 274 were female with a mean (SD) age of 19.6 (2.24). Approximately 19% of participants consumed alcohol beyond the safe limit of <14 units/week (112 g/week). Among them, 65% were males. Before university, 47% of students failed to meet the UK National Physical Activity Guidelines (NPAG) which increased to 56% during university with males exhibiting a steeper incline. Compared to their lifestyles before university, more students had insufficient sleep and displayed greater sedentariness during university. Moreover, 16% of students declared no engagement in PA which was greater than the value of 12% before university. Fitness perceptions worsened by 11% during university particularly for females. Statistical analysis revealed that gender, BMI and fitness perceptions were significantly correlated with PA levels. The most prevalent explanation for inadequacy in meeting NPAG was insufficient time. CONCLUSIONS Compared to their pre-university lifestyles, biological science students at university are more likely to adopt unhealthier behaviours with less time for exercise and prolonged sedentary behaviours, which increases the risk for cardiovascular diseases. It is important to raise awareness of their fitness perceptions and to encourage health-promoting programmes at university.
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Affiliation(s)
- S N Bhatti
- School of Biological Sciences, University of Reading, Harborne Building, Whiteknights, Reading RG6 6AS, UK
| | - A Leidi
- Statistical Services Centre Ltd, Reading, UK
| | - D Leake
- School of Biological Sciences, University of Reading, Reading, UK
| | - J-M Li
- School of Biological Sciences, University of Reading, Reading, UK
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Ahmad F, Leake D. Inhibition Of Lysosomal Oxidation Of Ldl Prevents Lysosomal Dysfunction, Cellular Senescence, Secretion Of Pro-Inflammatory Cytokines In Human Macrophages And Reduces Atherosclerosis In Mice. Atherosclerosis 2019. [DOI: 10.1016/j.atherosclerosis.2019.06.043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Gonzalez-Gonzalez E, Ra H, Hickerson RP, Wang Q, Piyawattanametha W, Mandella MJ, Kino GS, Leake D, Avilion AA, Solgaard O, Doyle TC, Contag CH, Kaspar RL. siRNA silencing of keratinocyte-specific GFP expression in a transgenic mouse skin model. Gene Ther 2009; 16:963-72. [PMID: 19474811 DOI: 10.1038/gt.2009.62] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Small interfering RNAs (siRNAs) can be designed to specifically and potently target and silence a mutant allele, with little or no effect on the corresponding wild-type allele expression, presenting an opportunity for therapeutic intervention. Although several siRNAs have entered clinical trials, the development of siRNA therapeutics as a new drug class will require the development of improved delivery technologies. In this study, a reporter mouse model (transgenic click beetle luciferase/humanized monster green fluorescent protein) was developed to enable the study of siRNA delivery to skin; in this transgenic mouse, green fluorescent protein reporter gene expression is confined to the epidermis. Intradermal injection of siRNAs targeting the reporter gene resulted in marked reduction of green fluorescent protein expression in the localized treatment areas as measured by histology, real-time quantitative polymerase chain reaction and intravital imaging using a dual-axes confocal fluorescence microscope. These results indicate that this transgenic mouse skin model, coupled with in vivo imaging, will be useful for development of efficient and 'patient-friendly' siRNA delivery techniques and should facilitate the translation of siRNA-based therapeutics to the clinic for treatment of skin disorders.
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Affiliation(s)
- E Gonzalez-Gonzalez
- Molecular Imaging Program at Stanford (MIPS), Stanford University School of Medicine, Stanford, CA, USA
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10
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Wen Y, Mills L, Zacharis C, Leake D. 4P-0996 Probucol can reduce Cu(II) to Cu(I) but is not a prooxidant for partially oxidised low density lipoprotein. ATHEROSCLEROSIS SUPP 2003. [DOI: 10.1016/s1567-5688(03)91254-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Evans D, Perez I, MacMorris M, Leake D, Wilusz CJ, Blumenthal T. A complex containing CstF-64 and the SL2 snRNP connects mRNA 3' end formation and trans-splicing in C. elegans operons. Genes Dev 2001; 15:2562-71. [PMID: 11581161 PMCID: PMC312790 DOI: 10.1101/gad.920501] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Polycistronic pre-mRNAs from Caenorhabditis elegans are processed by 3' end formation of the upstream mRNA and SL2-specific trans-splicing of the downstream mRNA. These processes usually occur within an approximately 100-nucleotide region and are mechanistically coupled. In this paper, we report a complex in C. elegans extracts containing the 3' end formation protein CstF-64 and the SL2 snRNP. This complex, immunoprecipitated with alphaCstF-64 antibody, contains SL2 RNA, but not SL1 RNA or other U snRNAs. Using mutational analysis we have been able to uncouple SL2 snRNP function and identity. SL2 RNA with a mutation in stem/loop III is functional in vivo as a trans-splice donor, but fails to splice to SL2-accepting trans-splice sites, suggesting that it has lost its identity as an SL2 snRNP. Importantly, stem/loop III mutations prevent association of SL2 RNA with CstF-64. In contrast, a mutation in stem II that inactivates the SL2 snRNP still permits complex formation with CstF-64. Therefore, SL2 RNA stem/loop III is required for both SL2 identity and formation of a complex containing CstF-64, but not for trans-splicing. These results provide a molecular framework for the coupling of 3' end formation and trans-splicing in the processing of polycistronic pre-mRNAs from C. elegans operons.
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Affiliation(s)
- D Evans
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Denver, CO 80262, USA
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12
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Abstract
Neurogenesis is correlated with the progressive synthesis of diverse neuronal intermediate filaments (IF) proteins. This apparent developmental regulation of IF protein gene expression suggests that specific neurofilament proteins impart unique structural attributes that support the staged growth of the neuron. In the teleost visual pathway, the sequential expression of two IF genes, plasticin and gefiltin, is linked to the age of retinal ganglion cells (RGCs) and to the regeneration of optic axons after nerve injury. Given this pattern of plasticin and gefiltin expression, we hypothesized that the two proteins would be sequentially expressed in zebrafish retina during development. We analyzed the pattern of gefiltin expression during zebrafish development and compared it to our previous determination of plasticin expression (Canger et al. 1998). Gefiltin is expressed after plasticin, during the later stages of retinal development when axons grow past the optic chiasm and innervate their targets. Thus, during RGC development, expression of plasticin and gefiltin resembles that with optic nerve regeneration. Outside of the visual pathway, gefiltin is predominantly expressed in the central nervous system whereas plasticin is primarily expressed in the peripheral nervous system. These results suggest that the expression of these genes is regulated in a neuron-specific manner. In addition, since plasticin and gefiltin are co-expressed during RGC development, these findings suggest a more complex mechanism of transcriptional regulation which orchestrates the sequential expression of these genes.
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Affiliation(s)
- D Leake
- Department of Biochemistry and Molecular Biology, State University of New York at Stony Brook, 11794, USA
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13
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Leigh-Firbank E, Minihane A, Patterson C, Leake D, Griffin B, Murphy M, Williams C. Changes in biological markers of N-3 polyunsaturated fatty acid supplementation are statistically correlated. Atherosclerosis 1999. [DOI: 10.1016/s0021-9150(99)80520-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Canger AK, Passini MA, Asch WS, Leake D, Zafonte BT, Glasgow E, Schechter N. Restricted expression of the neuronal intermediate filament protein plasticin during zebrafish development. J Comp Neurol 1998; 399:561-72. [PMID: 9741483 DOI: 10.1002/(sici)1096-9861(19981005)399:4<561::aid-cne8>3.0.co;2-#] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In the adult goldfish visual pathway, expression of the neuronal intermediate filament (nIF) protein plasticin is restricted to differentiating retinal ganglion cells (RGCs) at the margin of the retina. Following optic nerve injury, plasticin expression is elevated transiently in all RGCs coincident with the early stages of axon regeneration. These results suggest that plasticin may be expressed throughout the nervous system during the early stages of axonogenesis. To test this hypothesis, we analyzed plasticin expression during zebrafish (Danio rerio) neuronal development. By using immunocytochemistry and in situ hybridization, we found that plasticin is expressed in restricted subsets of early zebrafish neurons. Expression coincides with axon outgrowth in projection neurons that pioneer distinct axon tracts in the embryo. Plasticin is expressed first in trigeminal, Rohon-Beard, and posterior lateral line ganglia neurons, which are among the earliest neurons to initiate axonogenesis in zebrafish. Plasticin is expressed also in reticulospinal neurons and in caudal primary motoneurons. Together, these neurons establish the first behavioral responses in the embryo. Plasticin expression also coincides with initial RGC axonogenesis and progressively decreases after RGC axons reach the tectum. At later developmental stages, plasticin is expressed in a subset of the cranial nerves. The majority of plasticin-positive neurons are within or project axons to the peripheral nervous system. Our results suggest that plasticin subserves the changing requirements for plasticity and stability during axonal outgrowth in neurons that project long axons.
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Affiliation(s)
- A K Canger
- Department of Biochemistry and Cell Biology, State University of New York at Stony Brook, 11794, USA
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15
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Asch WS, Leake D, Canger AK, Passini MA, Argenton F, Schechter N. Cloning of zebrafish neurofilament cDNAs for plasticin and gefiltin: increased mRNA expression in ganglion cells after optic nerve injury. J Neurochem 1998; 71:20-32. [PMID: 9648847 DOI: 10.1046/j.1471-4159.1998.71010020.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [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: 11/20/2022]
Abstract
During retinal growth and optic axon regeneration, the differential expression of the neuronal intermediate filament proteins, plasticin and gefiltin, in the goldfish visual pathway suggests that these proteins support programmed axonal growth. To investigate plasticin and gefiltin during axonogenesis, we turned to the zebrafish, a system that is more amenable to mutational analysis. As a first step, we demonstrated that the intermediate filament compositions of goldfish and zebrafish are similar. In addition, the cDNAs for zebrafish plasticin and gefiltin were cloned and characterized. Using in situ hybridization in retina, we show increased mRNA levels for these proteins following optic nerve crush. Zebrafish plasticin and gefiltin peak and return to baseline levels of expression more rapidly than in goldfish. Furthermore, in the unoperated eye of experimental fish, there was a moderate increase in the levels of plasticin and gefiltin mRNA, suggesting that soluble factors influence the expression of these proteins. The successive expression of plasticin and gefiltin suggests that these neuronal intermediate filament proteins are integral components of axonogenesis. The cloning and characterization of cDNAs for plasticin and gefiltin permit mutational analyses of these proteins during zebrafish axonogenesis.
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Affiliation(s)
- W S Asch
- Department of Biochemistry and Cell Biology, State University of New York at Stony Brook, 11794, USA
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16
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Abstract
Lhermitte-Duclos disease (LDD) is a disorder sometimes referred to as a dysplastic gangliocytoma of the cerebellum. This is a focally indolent growth of the cerebellar cortex in which the folia enlarge due to a profusion of dysplastic cortical neurons and a thickening of the molecular layer. Loss of Purkinje cells and thinning of medullary white matter results. The enlarged folia lose their secondary foldings and asymmetrically expand the cerebellar hemisphere. These morphologic features produce a characteristic pattern on some CTs and all MRIs, affording an opportunity for a preoperative diagnosis. MRI of a pathologic specimen suggested that the abnormal T1 and T2 signals corresponded to the atrophic folial white matter, thickened granule cell layer, and outer molecular layer. Because of inherent Hounsfield artifact in posterior fossa with CT, MRI is the imaging modality of choice, with better visualized striated pattern. The uniqueness of these imaging features obviates the need for an obligatory biopsy for asymptomatic patients and either permits more definitive planning for surgical decompression or, in restricted lesions, guides more assuredly complete excision of the cerebellar mass.
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Affiliation(s)
- K Kulkantrakorn
- Department of Neurology, Saint Louis University Medical Center, MO 63110, USA
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17
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Abstract
The purpose of this review is to bring together the different approaches for studying the oxidation of low density lipoproteins and try to identify some critical factors which will permit greater comparability between laboratories. These issues are discussed both in terms of the variety of exogenous mediators of oxidation applied (transition metal ions, haem proteins, azo initiators, peroxynitrite, cells etc.) and their raisons d'être, as well as the methodologies (formation of conjugated dienes, hydroperoxides, decomposition products of lipid peroxidation, altered surface charge, macrophage uptake) applicable to the different stages of the oxidation and the factors underlying their accurate execution and interpretation.
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Affiliation(s)
- C Rice-Evans
- Division of Biochemistry and Molecular Biology, United Medical School of Guy's Hospital, London
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18
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Andrews B, Burnand K, Paganga G, Browse N, Rice-Evans C, Sommerville K, Leake D, Taub N. Oxidisability of low density lipoproteins in patients with carotid or femoral artery atherosclerosis. Atherosclerosis 1995; 112:77-84. [PMID: 7772070 DOI: 10.1016/0021-9150(94)05401-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [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: 01/27/2023]
Abstract
Oxidation of low density lipoprotein (LDL) is implicated in the pathogenesis of atherosclerosis. In this study the susceptibility to oxidation of LDL (from patients with atherosclerosis) is related to the progression of the disease. LDL were isolated from 37 patients with demonstrable atherosclerotic plaques. The susceptibility of LDL to oxidation (induced by an exogenous oxidative stress) was assessed by measuring the breakdown products of lipid peroxidation, the increased formation of conjugated dienes, and changes in surface charge of the apolipoprotein B (apo B). Progression of the atherosclerotic plaque was assessed by measuring the maximum velocity of blood through the narrowest portion of the vessel at inclusion and after one year. Twenty-nine of the 37 samples taken were found to have LDL that were partially oxidised, whereas 8 samples showed LDL whose state of oxidation was within the normal range. Progression of the atherosclerotic plaque occurred in 19 (66%) of the 29 patients whose lipoproteins were partially oxidised compared with only 2 (25%) of the 8 patients with normal lipoproteins (P = 0.055, Fisher's exact test). These data support an association between the progression of atherosclerotic plaques in carotid and femoral vessels and the susceptibility to oxidation of LDL.
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Affiliation(s)
- B Andrews
- Dept of Surgery, St Thomas' Hospital, London, UK
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19
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Kent A, Keenan AK, Herity NA, Allen JD, Silke B, Adgey AAJ, O’Halloran KD, Curran AK, Bradford A, Craig JA, Barlas P, Baxter GD, Walsh DM, Allen JM, Logan ID, Wilkinson YA, McKenna PG, Brayden DJ, Dunne J, Baird AW, Kelly JG, O’Connor JJ, Rowan MJ, Anwyl R, Caldwell M, Earley B, Leonard BE, Wedlock PM, Shephard RA, Bracken PJ, Fitzpatrick JM, O’Reilly C, Quinn E, Ryan MP, O’Neill J, Kernan RP, Craven CD, Healy E, Clarke H, Nolan CA, O’Connell C, Deegan PM, Abdelwahab YHA, Barnett CR, Flatt PR, MacSweeney C, Kelly JP, Cawley T, Geraghty J, Osborne H, Docherty JR, Nelson AA, McDowell BC, McCrory M, Deasy PB, Finan MP, Klatt PR, Hornykiewytsch T, Campion DP, Leek BF, Sharma SC, Barry-Kinsella C, Foran K, Thomas G, McKinney MW, O’Connor J, McKelvey-Martin VJ, Thompson CCM, McCarthy PJ, Hannigan BM, Thurnham DI, Chopra M, Leake D, Sheehy PJA, Delanty N, Murphy N, Lawson JA, FitzGerald GA, Fitzgerald DJ, Smyth EM, McCole D, O’Neill M, Canney M, Turley E, Strain JJ, Gallagher GA, Shields TD, O’Kane S, Eason SJ, Gilmore WS, King CM, Hejmadi M, McKeown SR, McAleer JJA, Patterson LH, Gray PSC, Lappin TRJ, Bridges JM, Richardson SAM, Murphy PG, Davidson N, Hooper ACB. Royal Academy of Medicine in Ireland Section of Biomedical Sciences Proceedings of Summer Meeting held 22nd & 23rd June, 1993. Ir J Med Sci 1994. [DOI: 10.1007/bf02965965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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20
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Paganga G, Rice-Evans C, Andrews B, Leake D. Oxidised low density lipoproteins convert oxyhaemoglobin from ruptured erythrocytes to reactive ferryl forms. Biochem Soc Trans 1992; 20:331S. [PMID: 1486997 DOI: 10.1042/bst020331s] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- G Paganga
- Free Radical Research Group, UMDS, Guy's Hospital, London
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21
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Leake D. Atherosclerosis Reviews 23: Atherosclerosis: Its Pathogenesis and the Role of Cholesterol. Cardiovasc Res 1992. [DOI: 10.1093/cvr/26.10.1007a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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22
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Abstract
Low-density lipoproteins (LDL) are oxidatively modified on interaction with haem proteins. The interaction of ruptured erythrocytes with LDL induces oxidative damage as detected by alterations in electrophoretic mobility and the peroxidation of the polyunsaturated fatty acyl chains. Difference spectroscopy reveals that the amplification of the oxidative process by the haem protein is related to the transition of the oxidation state of the haemoglobin in the erythrocyte lysate from the oxy [X-FeII-O2] to the ferryl [X-FeIV = O] form. The incorporation of the lipid-soluble antioxidant, butylated hydroxy toluene, at specific time points during the LDL-erythrocyte interaction prolongs the lag phase to oxidation and eliminates the oxy-to-ferryl conversion of the haemoglobin. The timescale of this haem conversion is related to the antioxidant status of the LDL.
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Affiliation(s)
- G Paganga
- Division of Biochemistry, United Medical School, Guy's Hospital, London, UK
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Abstract
Precise reconstruction of defects of facial bones including the neurocranium is now possible with the use of CAD/CAM technology and biomaterials, such as OsteoMesh, combined with bone grafting.
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Affiliation(s)
- D Leake
- UCLA Medical Center, Torrance, California
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24
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Mannai C, Leake D, Pizzoferrato A, Ciapetti G, Sangiorgi C. Histologic evaluation of purified bovine tendon collagen sponge in tooth extraction sites in dogs. Oral Surg Oral Med Oral Pathol 1986; 61:315-23. [PMID: 3458138 DOI: 10.1016/0030-4220(86)90408-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
This study presents a histologic evaluation of the healing process of dental extraction sites in dogs with and without the use of collagen sponge as an extraction site dressing. The healing process was evaluated at 3 days, 1 week, and 6 months after tooth extraction and appears comparable in both collagen-filled and nonfilled extraction sites.
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25
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Abstract
Surgical resection and replacement of a segment of the cervical trachea was performed in 8 mongrel dogs. The replacement was with a porous prosthesis made of Dacron cloth mesh stiffened with a heat-curing polyetherurethane. Ten tracheal rings were resected in each animal to create a complete circumferential defect of the trachea measuring 7 or 8 cm in length depending on the size of the dog. Animals were sacrificed periodically from 3 to 27 months post-reconstruction. The luminal surfaces of the reconstructed tracheae showed respiratory epithelium.
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26
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Michieli S, Pizzoferrato A, Leake D. Histologic evaluation of carbon-coated subperiosteal dental implants in dogs. Oral Surg Oral Med Oral Pathol 1984; 57:2-6. [PMID: 6582427 DOI: 10.1016/0030-4220(84)90248-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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27
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Pizzoferrato A, Schwartz HC, Leake D, Vespucci A, Leggeri P, Savarino L, Tarabusi C. [Reparative process after irradiation of autoplastic grafts in experimental surgical defects of the mandible]. Minerva Stomatol 1982; 31:311-26. [PMID: 6750348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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28
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Abstract
A new universal arch bar for intermaxillary fixation has been developed. This arch bar was fabricated as a wave-shaped, thin metal plate with soldered buttons on the bucco-labial aspect. It is light and flexible, yet strong enough to provide excellent fixation in the treatment of fractures of the maxilla and/or mandible. It is a universal bar: the superior and inferior borders are identical. Clinical application has been broad including trauma and cases of orthognathic surgery.
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29
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Michieli S, Bockros J, Haubald A, Freeman S, Leake D, Pizziferrato A. [Pyrolytic carbon coated metallic implants]. Zahnarztl Prax 1980; 31:492-7, 500-2. [PMID: 6937038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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30
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Michieli S, Pizzoferrato A, Freeman S, Leake D. Surgical lengthening of the mandible: a laboratory model. Oral Surg Oral Med Oral Pathol 1980; 50:207-13. [PMID: 6931992 DOI: 10.1016/0030-4220(80)90369-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Mandibular lengthening in mongrel dogs was evaluated in four animals. Extraoral approaches were used for mandibular exposure. Step osteotomies were performed on the buccal aspect and oblique osteotomies were performed on the lingual aspect of the mandible. The anterior fragment of the mandible was advanced 10 mm. A Dacron-urethane mesh tray, in the form of the mandible, was placed across the defect as a container of bone graft material and to help stabilize the segments. The bone graft material was harvested by aspirating the bone particles formed when the osteotomy cuts were made, thus creating a bone slurry which was placed within the implant. The results suggest that the use of the implant tray in conjunction with the bony slurry provided an appropriate physiologic setting for rapid new bone formation, restoring continuity to the defect.
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31
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Leake D, Michieli S, Pizzoferrato A, Freeman S. [Histologic examination of the soft tissues of implants with an elastomer coating]. Zahnarztl Prax 1980; 31:291-2. [PMID: 6937042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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32
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Abstract
Subperiosteal dental implants are not intended to replace conventional dentistry but provide an alternative method of treatment for the patient who cannot otherwise tolerate a dental prosthesis. Success can be achieved in the maxillae and in the mandible without the risk of serious complications. There are good prospects for a long-term favorable prognosis when appropriate surgical and prosthodontic criteria are observed.
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33
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Michieli S, Leake D, Freeman S, Bokros J, Haubold A, Pizzoferrato A. Vapor-deposited carbon-coated tooth root implants: preliminary evaluation of a stylized tooth implant system in dogs. J Prosthet Dent 1979; 42:58-66. [PMID: 287793 DOI: 10.1016/0022-3913(79)90331-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The results of this preliminary evaluation of a tooth implant model combining a stylized tooth root design and a thin, highly biocompatible microporous carbon coating, although tentative, add support to the feasibility of developing a statisfactory system for the immediate replacement of selected teeth in healthy bone.
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34
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Abstract
A method of restoring bony contour defects in the craniofacial regions employing a combination graft of autogenous bone and an alloplastic mesh is presented. Osteoinduction occurs within the confines of the alloplastic mesh from the cancellous bone and the resultant new bone conforms to the outline imposed by the alloplastic device. The advantages of this method include those of alloplastic materials combined with those of bone grafting. There is immediate restoration of an aesthetic contour with adequate strength and sound fixation.
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35
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Leake D, Schwartz HC, Michieli S, Habal MB, Freeman S. Status of selected biomaterials for oral and maxillofacial surgery. Biomater Med Devices Artif Organs 1979; 7:213-27. [PMID: 157171 DOI: 10.3109/10731197909117577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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36
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Pizzoferrato A, Leake D, Michieli S, Haubold A, Freeman S. Preliminary histologic evaluation of a biocompatible mesh for tracheal reconstruction. Biomater Med Devices Artif Organs 1979; 7:321-31. [PMID: 157173 DOI: 10.3109/10731197909117588] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The purpose of this study was to evaluate a porous Dacron - urethane mesh tracheal prosthesis in large dogs with surgically created discontinuous defects of the cervical trachea. Some protheses were carbon coated in an attempt to improve biocompatibility. Histology was performed on 2 dogs. The mucosa regenerated entirely covering the prosthesis. Respiratory epithelium was formed over a large central portion of the tracheas.
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37
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Michieli S, Gasparini F, Leake D, Pizzoferrato A, Bokros J. [Dental implants coated with isotropic carbon]. Minerva Stomatol 1978; 27:209-30. [PMID: 370541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
22 implants have been carried out in the mandibular arches of 5 dogs for the purpose of assessing the usefulness of a special isotropic carbon coating on vitallium cast dental replicas. Clinico-radiological, histopathological and microradiographic data showed the usefulness of the coating. Permucous acceptability, which is hard to obtain with other materials, proved satisfactory. Anchorage of the replicas to the surrounding bone was good, thus confirming the compatibility and usefulness of the isotropic carbon coating.
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38
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Abstract
The time has arrived when certain standards are to be introduced to control the introduction of and appropriate use of surgical implant devices. Now is the time for the professional groups involved in standards and medical device legislation to become active and develop surgical implant device standards to be applicable for the future. A commission could be established to work with FDA in respect to the requirements for surgical implant devices. It is time for the clinical organizations involved in writing consensus standards to cooperate in the introduction of surgical implant device standards.
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39
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Leake D, Habal M, Maniscalco J, Freeman S. Neurocranial reconstruction using an elastomer-coated cloth mesh and bone grafting. J Biomed Mater Res 1978; 12:83-7. [PMID: 147276 DOI: 10.1002/jbm.820120108] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The purpose of this report is to present out 5-year experience in reconstructing large bony defects in the cranial vault of 16 patients. The method employs an alloplastic implant device made of elastomer-coated cloth mesh, used in conjunction with bone grafting [D. L. Leake and M. Habal, J. Biomed. Mater. Res., 10, 555 (1976)]. The cranial defects ranged in size from 6 X 6 cm to 15 X 17 cm. The defects were in the frontal, temporoparietal, and occipital regions. Particularly challenging was the frontal-orbital region involving the superciliary ridges. The alloplastic implant provides controlled contour of the bone graft material while providing strength and stability during healing. The implant has adequate but not complete ridigity, allowing adaptability inthe operating room. The elastomer used is a polyetherurethane. Any biocompatible cloth mesh can be used, but Dacron [poly(ethylene terephthalate)] was chosen because of its extensive implant history. Contrasted with reconstruction using only bone, where as many as half of the cases had uneveness and were found to be anesthetically unsatisfactory, the technique described here has resulted in aesthetically excellent results and an intact neurocranium in the 16 patients studied thus far.
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40
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Maniscalco JE, Leake D, Habal MB. Cranioplasty. Use of a combination graft. J Fla Med Assoc 1976; 63:869-71. [PMID: 137270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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41
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42
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43
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44
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Leake D, Leake R. Neonatal suppurative parotitis. Pediatrics 1970; 46:202-7. [PMID: 4988260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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45
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46
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47
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Leake D, Leake R. Principles of general anesthesia for children. Anesth Prog 1967; 14:53-9. [PMID: 4226574 PMCID: PMC2235418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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48
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Leake D. First anesthesia site made national shrine. J Am Coll Dent 1966; 33:188-90. [PMID: 5328629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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49
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Leake D. First anesthesia site made national shrine. Anesth Prog 1966; 13:66-70. [PMID: 19598346 PMCID: PMC2235269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
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50
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Leake D. Doctors afield: Pierre Fauchard (1678-1761)--"Father of Dentistry". N Engl J Med 1961; 264:1150-1. [PMID: 13759920 DOI: 10.1056/nejm196106012642209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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