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Cecil CA, Harris ZL, Sanchez-Pinto LN, Macy ML, Newmyer RE. Characteristics of Children Who Deteriorate After Transport and Associated Preadmission Factors. Air Med J 2022; 41:380-384. [PMID: 35750445 DOI: 10.1016/j.amj.2022.04.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 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] [Received: 03/01/2022] [Accepted: 04/25/2022] [Indexed: 06/15/2023]
Abstract
OBJECTIVE The incidence of deterioration and associated characteristics are largely unknown for children transported for admission from referring emergency departments (EDs) to general inpatient units. This study describes this population and identifies associated preadmission characteristics. METHODS This single-center cohort study included children ≤ 18 years old transferred from an ED and directly admitted to general inpatient units from 2016 to 2019. Deterioration was defined as 1 or more of the following occurring within 24 hours of admission: rapid response team activation, transfer to the intensive care unit (ICU), or cardiac or respiratory arrest. ICU transfer was the secondary outcome. Logistic regression was performed. RESULTS One thousand nine hundred eighty-eight patients were included; the median age was 4.2 years, 53.9% were male, and 44.1% had respiratory diagnoses. Deterioration occurred in 135 (6.8%) children overall and in 10.1% of children with respiratory complaints. Deterioration was associated with ≥ 2 complex chronic conditions (adjusted odds ratio [aOR] = 2.09; 95% confidence interval [CI], 1.04-4.19) and a longer stabilization time (per 10 minutes) (aOR = 1.17; 95% CI, 1.01-1.36). ICU transfer was associated with ≥ 2 complex chronic conditions (aOR = 2.33; 95% CI, 1.13-4.80), supplemental oxygen via nasal cannula (aOR = 2.13; 95% CI, 1.18-3.85), and nebulizer treatment (aOR = 2.77; 95% CI, 1.21-6.35). CONCLUSION Deterioration was experienced by 7% of children admitted to a general unit, with the majority having respiratory complaints. Transport teams should consider the potential for increased risk of deterioration among children with respiratory disease, multiple complex chronic conditions, and a nasal cannula or nebulizer therapy. The clinical significance of marginally longer stabilization times is unclear and warrants further investigation.
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Affiliation(s)
- Cara A Cecil
- Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL; Department of Pediatrics, Northwestern University Feinberg School Medicine, Chicago, IL.
| | - Z Leah Harris
- Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL; Department of Pediatrics, Northwestern University Feinberg School Medicine, Chicago, IL
| | - L Nelson Sanchez-Pinto
- Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL; Department of Pediatrics, Northwestern University Feinberg School Medicine, Chicago, IL
| | - Michelle L Macy
- Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL; Department of Pediatrics, Northwestern University Feinberg School Medicine, Chicago, IL
| | - Robert E Newmyer
- Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL; Department of Pediatrics, Northwestern University Feinberg School Medicine, Chicago, IL
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2
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Maddux AB, Campbell K, Woodruff AG, LaVelle J, Lutmer J, Kennedy CE, Malakooti M, McGuire JK, Shekerdemian L, Harris ZL, McCrory MC, Carpenter TC. The Impact of Strict Public Health Restrictions on Pediatric Critical Illness. Crit Care Med 2021; 49:2033-2041. [PMID: 34259665 PMCID: PMC8594504 DOI: 10.1097/ccm.0000000000005200] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
OBJECTIVES To characterize the impact of public health interventions on the volume and characteristics of admissions to the PICU. DESIGN Multicenter retrospective cohort study. SETTING Six U.S. referral PICUs during February 15, 2020-May 14, 2020, compared with the same months during 2017-2019 (baseline). PATIENTS PICU admissions excluding admissions for illnesses due to severe acute respiratory syndrome coronavirus 2 and readmissions during the same hospitalization. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Primary outcome was admission volumes during the period of stay-at-home orders (March 15, 2020-May 14, 2020) compared with baseline. Secondary outcomes were hospitalization characteristics including advanced support (e.g., invasive mechanical ventilation), PICU and hospital lengths of stay, and mortality. We used generalized linear mixed modeling to compare patient and admission characteristics during the stay-at-home orders period to baseline. We evaluated 7,960 admissions including 1,327 during March 15, 2020-May 14, 2020. Daily admissions and patients days were lower during the period of stay-at-home orders compared with baseline: median admissions 21 (interquartile range, 17-25) versus 36 (interquartile range, 30-42) (p < 0.001) and median patient days 93.0 (interquartile range, 55.9-136.7) versus 143.6 (interquartile range, 108.5-189.2) (p < 0.001). Admissions during the period of stay-at-home orders were less common in young children and for respiratory and infectious illnesses and more common for poisonings, endocrinopathies and for children with race/ethnicity categorized as other/unspecified. There were no differences in hospitalization characteristics except fewer patients received noninvasive ventilation during the period of stay-at-home orders. CONCLUSIONS Reductions in PICU admissions suggest that much of pediatric critical illness in younger children and for respiratory and infectious illnesses may be preventable through targeted public health strategies.
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Affiliation(s)
- Aline B Maddux
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO
- Section of Pediatric Critical Care Medicine, Children's Hospital Colorado, Aurora, CO
| | - Kristen Campbell
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO
| | - Alan G Woodruff
- Department of Anesthesiology, Section of Pediatric Critical Care Medicine, Wake Forest School of Medicine, Winston Salem, NC
| | - Jaime LaVelle
- Section of Pediatric Critical Care Medicine, Children's Hospital Colorado, Aurora, CO
| | - Jeffrey Lutmer
- Nationwide Children's Hospital, Columbus, OH
- Department of Pediatrics, Section of Pediatric Critical Care Medicine, The Ohio State University College of Medicine, Columbus, OH
| | - Curt E Kennedy
- Baylor College of Medicine, Houston, TX
- Texas Children's Hospital, Houston, TX
| | - Marcelo Malakooti
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL
- Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL
| | - John K McGuire
- Division of Pediatric Critical Care Medicine, Department of Pediatrics, University of Washington School of Medicine, Seattle, WA
| | - Lara Shekerdemian
- Baylor College of Medicine, Houston, TX
- Texas Children's Hospital, Houston, TX
| | - Z Leah Harris
- Department of Pediatrics, The University of Texas at Austin and Dell Children's Medical Center, Austin, TX
| | - Michael C McCrory
- Department of Anesthesiology, Section of Pediatric Critical Care Medicine, Wake Forest School of Medicine, Winston Salem, NC
| | - Todd C Carpenter
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO
- Section of Pediatric Critical Care Medicine, Children's Hospital Colorado, Aurora, CO
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3
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Prendergast E, Allen KY, Mills MG, Moran T, Harris ZL, Malakooti M, Smith CM, Wainwright MS, McCarthy-Kowols M. Targeted Temperature Management Protocol in a Pediatric Intensive Care Unit: A Quality Improvement Project. Crit Care Nurse 2021; 41:41-50. [PMID: 34595494 DOI: 10.4037/ccn2021554] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
BACKGROUND In patients with acute neurological injury, abrupt temperature change exacerbates increased intracranial pressures and negatively affects perfusion pressure and cerebral blood flow. Critical care nurses must provide coordinated and effective interventions to maintain normothermia without precipitating shivering immediately after acute neurological injury in pediatric patients. OBJECTIVE To improve hyperthermia management in a 40-bed pediatric intensive care unit, an interdisciplinary pediatric critical care team developed, implemented, and evaluated a targeted temperature management protocol. METHODS The project was guided by the organization's plan-do-study-act quality improvement process. Quality improvement was assessed retrospectively using electronic medical records of patients meeting eligibility criteria. Samples of pediatric patients who received temperature interventions were compared before and after protocol implementation. The protocol included environmental, pharmacological, and body surface cooling device interventions, as well as use of a bedside shivering assessment scale and stepwise interventions to prevent and control shivering. RESULTS Before implementation of the targeted temperature management protocol, 64% of patients had documented temperatures higher than 37.5 °C, and body surface cooling devices were used in 10% of patients. After protocol implementation, more than 80% of patients had documented temperatures higher than 37.5 °C, and body surface cooling devices were used in 62% of patients. Four patients (6%) before and 5 patients (31%) after protocol implementation were treated with body surface cooling without requiring use of neuromuscular blockade. CONCLUSIONS Creation and implementation of a targeted temperature management protocol increased nurses' documented use of body surface cooling to manage hyperthermia in pediatric intensive care unit patients with acute neurological injury.
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Affiliation(s)
- Erica Prendergast
- Erica Prendergast is a neurocritical care nurse practitioner, Ruth D. & Ken M. Davee Pediatric Neurocritical Care Program, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
| | - Kiona Y Allen
- Kiona Y. Allen is Medical Director of the Regenstein Cardiac Care Unit and Associate Director of the NICU-Cardiac Neurodevelopmental Program, Ann & Robert H. Lurie Children's Hospital of Chicago, and an assistant professor, Department of Pediatrics, Division of Cardiology and Division of Critical Care Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Michele Grimason Mills
- Michele Grimason Mills is a neurocritical care nurse practitioner, Ruth D. & Ken M. Davee Pediatric Neurocritical Care Program, Ann & Robert H. Lurie Children's Hospital of Chicago
| | - Thomas Moran
- Thomas Moran is Manager of Clinical Pharmacy Services, Ann & Robert H. Lurie Children's Hospital of Chicago
| | - Z Leah Harris
- Z. Leah Harris is Chairman of Pediatrics at Dell Medical School, University of Texas at Austin, and Director of the Dell Pediatric Research Institute and Physician-in-Chief at Dell Children's Medical Center, Austin, Texas
| | - Marcelo Malakooti
- Marcelo Malakooti is Associate Chief Medical Officer and Medical Director of the pediatric intensive care unit, Ann & Robert H. Lurie Children's Hospital of Chicago, and an assistant professor, Department of Pediatrics, Division of Critical Care Medicine, Northwestern University Feinberg School of Medicine
| | - Craig M Smith
- Craig Smith is an assistant professor of pediatrics and neurology, Northwestern University Feinberg School of Medicine, and faculty for pediatric critical care medicine and neurocritical care, Ruth D. & Ken M. Davee Pediatric Neurocritical Care Program, Ann & Robert H. Lurie Children's Hospital of Chicago
| | - Mark S Wainwright
- Mark S. Wainwright is Division Head of Pediatric Neurology, University of Washington, Seattle
| | - Maureen McCarthy-Kowols
- Maureen McCarthy-Kowols is a former nursing professional development practitioner/clinical educator, Ann & Robert H. Lurie Children's Hospital of Chicago
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Weese-Mayer DE, Leah Harris Z, Paquette ET, Sanchez-Pinto LN. In memoriam: Lauren E. Marsillio-Craney (1979-2020). Clin Auton Res 2021; 31:589-590. [PMID: 34120248 DOI: 10.1007/s10286-021-00812-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Debra E Weese-Mayer
- Division of Pediatric Autonomic Medicine, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago and Stanley Manne Children's Research Institute, 225 East Chicago Avenue, Box 165, Chicago, IL, 60611-2605, USA. .,Northwestern University Feinberg School of Medicine, Chicago, IL, 60611-2605, USA.
| | - Z Leah Harris
- Department of Pediatrics, Dell Children's Medical Center and Dell Pediatric Research Institute, 4900 Mueller Boulevard, Austin, TX, 78723, USA.,University of Texas at Austin Dell Medical School, Austin, TX, 78723, USA
| | - Erin T Paquette
- Northwestern University Feinberg School of Medicine, Chicago, IL, 60611-2605, USA.,Division of Critical Care Medicine, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago and Stanley Manne Children's Research Institute, 225 East Chicago Avenue, Box 165, Chicago, IL, 60611-2605, USA
| | - L Nelson Sanchez-Pinto
- Northwestern University Feinberg School of Medicine, Chicago, IL, 60611-2605, USA.,Division of Critical Care Medicine, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago and Stanley Manne Children's Research Institute, 225 East Chicago Avenue, Box 165, Chicago, IL, 60611-2605, USA
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5
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Badke CM, Friedman ML, Harris ZL, McCarthy-Kowols M, Tran S. Impact of an untrained CPR Coach in simulated pediatric cardiopulmonary arrest: A pilot study. Resusc Plus 2020; 4:100035. [PMID: 34223312 PMCID: PMC8244490 DOI: 10.1016/j.resplu.2020.100035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/21/2020] [Accepted: 09/25/2020] [Indexed: 11/21/2022] Open
Abstract
Aim To determine if an untrained cardiopulmonary resuscitation (CPR) Coach, with no access to real-time CPR feedback technology, improves CPR quality. Methods This was a prospective randomized pilot study at a tertiary care children's hospital that aimed to integrate an untrained CPR Coach into resuscitation teams during simulated pediatric cardiac arrest. Simulation events were randomized to two arms: control (no CPR Coach) or intervention (CPR Coach). Simulations were run by pediatric intensive care unit (PICU) providers and video recorded. Scenarios focused on full cardiopulmonary arrest; neither team had access to real-time CPR feedback technology. The primary outcome was CPR quality. Secondary outcomes included workload assessments of the team leader and CPR Coach using the NASA Task Load Index and perceptions of CPR quality. Results Thirteen simulations were performed; 5 were randomized to include a CPR Coach. There was a significantly shorter duration to backboard placement in the intervention group (median 20 s [IQR 0–27 s] vs. 52 s [IQR 38–65 s], p = 0.02). There was no self-reported change in the team leader's workload between scenarios using a CPR Coach compared to those without a CPR Coach. There were no significant changes in subjective CPR quality measures. Conclusions In this pilot study, inclusion of an untrained CPR Coach during simulated CPR shortened time to backboard placement but did not improve most metrics of CPR quality or significantly affect team leader workload. More research is needed to better assess the value of a CPR Coach and its potential impact in real-world resuscitation.
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Affiliation(s)
- Colleen M. Badke
- Division of Critical Care Medicine, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, 225 E. Chicago Ave., Chicago, IL 60611, United States
- Corresponding author.
| | - Matthew L. Friedman
- Division of Pediatric Critical Care, Indiana University, 705 Riley Hospital Drive, Rm 4900, Indianapolis, IN 46202, United States
| | - Z. Leah Harris
- Division of Critical Care Medicine, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, 225 E. Chicago Ave., Chicago, IL 60611, United States
| | - Maureen McCarthy-Kowols
- Division of Critical Care Medicine, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, 225 E. Chicago Ave., Chicago, IL 60611, United States
| | - Sifrance Tran
- Division of Pediatric Surgery, Department of Surgery, University of Texas Medical Branch – Galveston, 301 University Blvd., Galveston, TX 77555-0353, United States
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Zhao L, Hadziahmetovic M, Wang C, Xu X, Song Y, Jinnah HA, Wodzinska J, Iacovelli J, Wolkow N, Krajacic P, Weissberger AC, Connelly J, Spino M, Lee MK, Connor J, Giasson B, Harris ZL, Dunaief JL. Cp/Heph mutant mice have iron-induced neurodegeneration diminished by deferiprone. J Neurochem 2015; 135:958-74. [PMID: 26303407 DOI: 10.1111/jnc.13292] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [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: 05/19/2015] [Revised: 07/31/2015] [Accepted: 08/14/2015] [Indexed: 12/31/2022]
Abstract
Brain iron accumulates in several neurodegenerative diseases and can cause oxidative damage, but mechanisms of brain iron homeostasis are incompletely understood. Patients with mutations in the cellular iron-exporting ferroxidase ceruloplasmin (Cp) have brain iron accumulation causing neurodegeneration. Here, we assessed the brains of mice with combined mutation of Cp and its homolog hephaestin. Compared to single mutants, brain iron accumulation was accelerated in double mutants in the cerebellum, substantia nigra, and hippocampus. Iron accumulated within glia, while neurons were iron deficient. There was loss of both neurons and glia. Mice developed ataxia and tremor, and most died by 9 months. Treatment with the oral iron chelator deferiprone diminished brain iron levels, protected against neuron loss, and extended lifespan. Ferroxidases play important, partially overlapping roles in brain iron homeostasis by facilitating iron export from glia, making iron available to neurons. Above: Iron (Fe) normally moves from capillaries to glia to neurons. It is exported from the glia by ferroportin (Fpn) with ferroxidases ceruloplasmin (Cp) and/or Hephaestin (Heph). Below: In mice with mutation of Cp and Heph, iron accumulates in glia, while neurons have low iron levels. Both neurons and glia degenerate and mice become ataxic unless given an iron chelator.
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Affiliation(s)
- Liangliang Zhao
- F.M Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Ophthalmology, The Second Hospital of Jilin University, Jilin, China
| | - Majda Hadziahmetovic
- F.M Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Ophthalmology, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
| | - Chenguang Wang
- F.M Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Ophthalmology, The Second Hospital of Jilin University, Jilin, China
| | - Xueying Xu
- Department of Medicine, Sinai Hospital, Baltimore, Maryland, USA
| | - Ying Song
- F.M Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - H A Jinnah
- Departments of Neurology, Human Genetics and Pediatrics, Emory University School of Medicine, Atlanta, Georgia, USA
| | | | - Jared Iacovelli
- F.M Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Natalie Wolkow
- F.M Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Predrag Krajacic
- F.M Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Alyssa Cwanger Weissberger
- F.M Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Michael Spino
- ApoPharma Inc, Toronto, California, USA.,Leslie Dan Faculty of Pharmacy, University of Toronto M5S 3M2, Toronto, Canada
| | - Michael K Lee
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA
| | - James Connor
- Department of Neurosurgery, Penn State Milton S. Hershey Medical Center, Hershey, Pennsylvania, USA
| | - Benoit Giasson
- Department of Neuroscience, College of Medicine, University of Florida, Gainesville, Florida, USA
| | - Z Leah Harris
- Department of Pediatrics, Northwestern University, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
| | - Joshua L Dunaief
- F.M Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Abramo TJ, Harris ZL, Meredith M, Crossman K, Seupaul R, Williams A, McMorrow S, Dindo J, Gordon A, Melguizo-Castro M, Hu Z, Nick T. Cerebral oximetry with cerebral blood volume index in detecting pediatric stroke in a pediatric ED. Am J Emerg Med 2015; 33:1622-9. [PMID: 26320671 DOI: 10.1016/j.ajem.2015.07.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 07/17/2015] [Accepted: 07/19/2015] [Indexed: 10/23/2022] Open
Abstract
BACKGROUND Despite pediatric stroke awareness and pediatric stroke activation systems, recognition and imaging delays along with activation inconsistency still occur. Reliable objective pediatric stroke detection tools are needed to improve detection and activations. Regional cerebral oxygen saturation (rcso2) with cerebral blood volume index (CBVI) can detect abnormal cerebral physiology. OBJECTIVE To determine cerebral oximetry in detecting strokes in stroke alert and overall stroke patients. METHOD Left rcso2, right rcso2, and rcso2 side differences for stroke, location, and types were analyzed. RESULTS Compared with stroke alert (n = 25) and overall strokes (n = 52), rcso2 and CBVI were less than those in nonstrokes (n = 133; P < .0001). Rcso2 side differences in stroke alert and overall strokes were greater than in nonstrokes (P < .0001). Lower rcso2 and CBVI correlated with both groups' stroke location, left (P < .0001) and right rcso2 (P = .004). Rcso2 differences greater than 10 had a 100% positive predictive value for stroke. Both groups' rcso2 and CBVI side differences were consistent for stroke location and type (P < .0001). For both groups, left rcso2 and CBVI were greater than those of the right (P < .0001). Hemorrhagic strokes had lower bilateral rcso2 and CBVI than did ischemic strokes (P < .001). CONCLUSIONS Cerebral oximetry and CBVI detected abnormal cerebral physiology, stroke location, and type (hemorrhagic or ischemic). Rcso2 side differences greater than 10 or rcso2 readings less than 50% had a 100% positive predictive value for stroke. Cerebral oximetry has shown potential as a detection tool for stroke location and type in a pediatric stroke alert and nonalert stroke patients. Using cerebral oximetry by the nonneurologist, we found that the patient's rcso2 side difference greater than 10 or one or both sides having less than 50% rcso2 readings suggests abnormal hemispheric pathology and expedites the patient's diagnosis, neuroresuscitation, and radiologic imaging.
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Affiliation(s)
- Thomas J Abramo
- Department of Pediatrics, Division of Pediatric Emergency Medicine, University of Arkansas School of Medicine, Arkansas Children's Hospital, Little Rock, AR.
| | - Z Leah Harris
- Department of Pediatrics, Division of Critical Care Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL
| | - Mark Meredith
- Department of Pediatrics, Division of Pediatric Emergency Medicine, University of Tennessee, Memphis, TN
| | - Kristen Crossman
- Vanderbilt University Medical Center, Vanderbilt School of Medicine, Nashville, TN
| | - Rawle Seupaul
- UAMS Department of Emergency Medicine, Little Rock, AR
| | - Abby Williams
- Pediatric Emergency Medicine Associates, Atlanta, GA
| | - Sheila McMorrow
- Vanderbilt University Medical Center, Vanderbilt School of Medicine, Nashville, TN
| | | | | | - Maria Melguizo-Castro
- Department of Pediatrics, Division of Pediatric Emergency Medicine, University of Arkansas School of Medicine, Arkansas Children's Hospital, Little Rock, AR
| | - Zhuopei Hu
- Department of Pediatrics, Division of Pediatric Emergency Medicine, University of Arkansas School of Medicine, Arkansas Children's Hospital, Little Rock, AR
| | - Todd Nick
- Department of Pediatrics, Division of Pediatric Emergency Medicine, University of Arkansas School of Medicine, Arkansas Children's Hospital, Little Rock, AR
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Ladner TR, Mahdi J, Harris ZL, Crossman K, Abramo T, Jordan LC. Abstract T P360: Pediatric Acute Stroke Protocol Activation in a Children’s Hospital Emergency Department. Stroke 2015. [DOI: 10.1161/str.46.suppl_1.tp360] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction:
Many children’s hospitals, including ours, have instituted acute stroke protocols, with a pediatric acute stroke team that is alerted and responds urgently for children with acute brain attacks. The purpose of this study was to characterize the final diagnoses of children with brain attacks in the emergency department where the acute stroke protocol was activated.
Hypothesis:
We hypothesized that less than half of pediatric brain attacks would have a confirmed diagnosis of acute stroke.
Methods:
Clinical and demographic information were obtained from a quality improvement database and medical records for consecutive patients (age 0-20 y) presenting to a single institution’s pediatric emergency department where the acute stroke protocol was activated between April 2011 and December 2013. Activation of this protocol means that a neurology resident sees the child within 15 minutes and acute MRI is available. All values were assessed with descriptive statistics.
Results:
There were 100 cases of brain attack (mean age 11.3 y, SD 5.1 y, 55% male); 25 were confirmed strokes (Figure) and 3 children had a transient ischemic attack (TIA). Nine (36%) children with stroke were previously healthy. There were 17 (68%) ischemic strokes, 7 (28%) hemorrhages, and 1 (4%) sinovenous thrombosis. Non-stroke neurological emergencies were found in 13% of patients; the majority were meningitis (n=5) or neoplasm (n=3). Complex migraine was present in 17% and seizure in 12%. All children had urgent neuroimaging. MRI was the first study in 70%.
Conclusion:
Of pediatric brain attacks, 25% were stroke, 3% were TIA, and 13% were other neurological emergencies. Clinicians evaluating a child for possible acute stroke should consider these frequencies in their differential diagnosis. There are many stroke mimics, some life-threatening, underscoring the need for prompt evaluation and management of children with brain attacks.
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Affiliation(s)
| | - Jasia Mahdi
- Vanderbilt Univ Sch of Medicine, Nashville, TN
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Young BE, Cooper EM, McIntyre AW, Kent T, Witter F, Harris ZL, O'Brien KO. Placental vitamin D receptor (VDR) expression is related to neonatal vitamin D status, placental calcium transfer, and fetal bone length in pregnant adolescents. FASEB J 2014; 28:2029-37. [DOI: 10.1096/fj.13-246736] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Bridget E. Young
- Division of Nutritional SciencesCornell UniversityIthacaNew YorkUSA
| | | | | | - Tera Kent
- Division of Nutritional SciencesCornell UniversityIthacaNew YorkUSA
| | - Frank Witter
- Johns Hopkins School of MedicineBaltimoreMarylandUSA
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10
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Young BE, McNanley TJ, Cooper EM, McIntyre AW, Witter F, Harris ZL, O'Brien KO. Maternal vitamin D status and calcium intake interact to affect fetal skeletal growth in utero in pregnant adolescents. Am J Clin Nutr 2012; 95:1103-12. [PMID: 22492380 PMCID: PMC3325835 DOI: 10.3945/ajcn.111.023861] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Maternal calcium intake and vitamin D status may affect fetal bone development. OBJECTIVE This study was designed to examine relations between maternal calcium intake, 25-hydroxyvitamin D [25(OH)D] status, and fetal bone growth across pregnancy. DESIGN This was a prospective longitudinal design. Maternal 25(OH)D, parathyroid hormone, and 1,25-dihydroxyvitamin D [1,25(OH)(2)D] were determined at midgestation (∼26 wk) and at delivery in 171 adolescents (≤ 18 y). Dietary recalls and fetal sonograms were performed up to 3 times across gestation, and fetal femur and humerus z scores were generated. RESULTS Fetal femur and humerus z scores and neonatal birth length were significantly greater (P < 0.03) in adolescents consuming ≥ 1050 mg than in those consuming <1050 mg Ca/d. Maternal 25(OH)D > 50 nmol/L was significantly positively associated with fetal femur and humerus z scores (P < 0.01). When maternal smoking, height, race, weight gain, and gestational age were controlled for, these relations remained significant. Interactions between calcium intake and 25(OH)D were evident. Calcium intake was associated with fetal femur z scores and birth length only when maternal 25(OH)D was ≤ 50 nmol/L (P < 0.05). Similarly, maternal 25(OH)D was associated with fetal femur and humerus z scores only when maternal calcium intake was <1050 mg/d (P < 0.03). CONCLUSIONS Optimal calcium intake and adequate maternal vitamin D status are both needed to maximize fetal bone growth. Interactions between these nutrients were evident when either calcium or vitamin D status was limited. Improving maternal calcium intake and/or vitamin D status during pregnancy may have a positive effect on fetal skeletal development in pregnant adolescents.
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Affiliation(s)
- Bridget E Young
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
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Young BE, McNanley T, Cooper B, Witter F, Harris ZL, O'Brien K. Pre‐pregnancy BMI Impacts Bone Loss across Pregnancy in Adolescents. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.119.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Beth Cooper
- University of Rochester School of MedicineRochesterNY
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12
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Young MF, Griffin I, Pressman E, McIntyre AW, Cooper E, McNanley T, Harris ZL, Westerman M, O’Brien KO. Maternal hepcidin is associated with placental transfer of iron derived from dietary heme and nonheme sources. J Nutr 2012; 142:33-9. [PMID: 22113871 PMCID: PMC3237230 DOI: 10.3945/jn.111.145961] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The determinants of placental transport of dietary iron remain largely uncharacterized. The objective of this research was to elucidate determinants of fetal Fe transfer from maternally ingested dietary heme and non-heme Fe. The study was undertaken in 19 pregnant females (16-32 y) who ingested intrinsically labeled (58)Fe-heme and a nonheme Fe source ((57)FeSO(4)) during the third trimester of pregnancy. At delivery, maternal and cord blood was obtained to assess neonatal (57)Fe and (58)Fe enrichment as a function of maternal/neonatal Fe status [serum ferritin (SF), transferrin receptor, hemoglobin (Hb), total body Fe, and hepcidin]. There was a greater percentage of maternally absorbed (58)Fe tracer present in the neonates compared to the (57)Fe tracer (5.4 ± 2.4 vs. 4.0 ± 1.6; P < 0.0001). Net dietary nonheme Fe (mg) and heme Fe (mg) transferred to the fetus were both inversely correlated with measures of maternal serum hepcidin (P = 0.002, r(2) = 0.43; P = 0.004, r(2) = 0.39) and SF (P = 0.0008, r(2) = 0.49; P = 0.003, r(2) = 0.41) and directly associated with neonatal Hb (P = 0.004, r(2) = 0.39; P = 0.008, r(2) = 0.35). The results of this study suggest that during pregnancy there appears to be preferential fetal use of maternally ingested Fe derived from a dietary, animal-based heme source compared to Fe ingested as ferrous sulfate. Maternal serum hepcidin and maternal/neonatal Fe status may play a role in placental uptake of dietary heme and nonheme Fe.
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Affiliation(s)
- Melissa F. Young
- Cornell University, Division of Nutritional Sciences, Ithaca, NY
| | - Ian Griffin
- USDA/Agricultural Research Service Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX
| | - Eva Pressman
- The University of Rochester School of Medicine, Rochester, NY
| | | | | | - Thomas McNanley
- The University of Rochester School of Medicine, Rochester, NY
| | - Z. Leah Harris
- Vanderbilt University Medical Center, Department of Pediatrics, Nashville, TN; and
| | | | - Kimberly O. O’Brien
- Cornell University, Division of Nutritional Sciences, Ithaca, NY,To whom correspondence should be addressed. E-mail:
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Young BE, McNanley TJ, Cooper EM, McIntyre AW, Witter F, Harris ZL, O'Brien KO. Vitamin D insufficiency is prevalent and vitamin D is inversely associated with parathyroid hormone and calcitriol in pregnant adolescents. J Bone Miner Res 2012; 27:177-86. [PMID: 21956833 PMCID: PMC3291801 DOI: 10.1002/jbmr.526] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [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: 05/29/2011] [Revised: 08/28/2011] [Accepted: 09/22/2011] [Indexed: 11/11/2022]
Abstract
Few large studies have assessed changes in calcitropic hormones and maternal 25-hydroxyvitamin D (25(OH)D) status across pregnancy, and how this may impact maternal bone turnover and neonatal hormone status. We aimed to identify determinants of 25(OH)D, parathyroid hormone (PTH), and calcitriol across pregnancy in a longitudinal study of 168 pregnant adolescents (≤18 years of age). Maternal 25(OH)D, PTH, and calcitriol were assessed at mid-gestation (∼26 weeks), delivery, and in cord blood. Data were related to measures of maternal anthropometrics, dietary intake, physical activity, and bone turnover markers. Approximately 50% of teens and their infants had serum 25(OH)D ≤ 20 ng/mL; 25(OH)D was lower in African Americans versus whites (p < 0.001). PTH increased across gestation (p < 0.001). Elevated PTH (≥60 pg/mL) was detected in 25% of adolescents at delivery, and was associated with increased concentrations of serum N-telopeptide (NTX) (p = 0.028). PTH and calcitriol did not significantly differ across the range of Ca intake consumed (257-3220 mg/d). In the group as a whole, PTH was inversely associated with 25(OH)D in maternal circulation at mid-gestation (p = 0.023) and at delivery (p = 0.019). However, when the cohort was partitioned by 25(OH)D status, this relationship was only present in those with 25(OH)D ≤ 20 ng/mL, suggestive of a threshold below which 25(OH)D impacts PTH during pregnancy. Mid-gestation 25(OH)D was inversely associated with calcitriol at delivery (p = 0.023), irrespective of Ca intake. Neonatal PTH and calcitriol were significantly lower than (p < 0.001), but unrelated to maternal concentrations. These findings indicate that maternal 25(OH)D status plays a role in calcitropic hormone regulation in pregnant adolescents.
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Affiliation(s)
- Bridget E Young
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
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14
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Texel SJ, Zhang J, Camandola S, Unger EL, Taub DD, Koehler RC, Harris ZL, Mattson MP. Ceruloplasmin deficiency reduces levels of iron and BDNF in the cortex and striatum of young mice and increases their vulnerability to stroke. PLoS One 2011; 6:e25077. [PMID: 21949858 PMCID: PMC3174999 DOI: 10.1371/journal.pone.0025077] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [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: 05/18/2011] [Accepted: 08/26/2011] [Indexed: 11/26/2022] Open
Abstract
Ceruloplasmin (Cp) is an essential ferroxidase that plays important roles in cellular iron trafficking. Previous findings suggest that the proper regulation and subcellular localization of iron are very important in brain cell function and viability. Brain iron dyshomeostasis is observed during normal aging, as well as in several neurodegenerative disorders such as Alzheimer's, Parkinson's and Huntington's diseases, coincident with areas more susceptible to insults. Because of their high metabolic demand and electrical excitability, neurons are particularly vulnerable to ischemic injury and death. We therefore set out to look for abnormalities in the brain of young adult mice that lack Cp. We found that iron levels in the striatum and cerebral cortex of these young animals are significantly lower than wild-type (WT) controls. Also mRNA levels of the neurotrophin brain derived neurotrophic factor (BDNF), known for its role in maintenance of cell viability, were decreased in these brain areas. Chelator-mediated depletion of iron in cultured neural cells resulted in reduced BDNF expression by a posttranscriptional mechanism, suggesting a causal link between low brain iron levels and reduced BDNF expression. When the mice were subjected to middle cerebral artery occlusion, a model of focal ischemic stroke, we found increased brain damage in Cp-deficient mice compared to WT controls. Our data indicate that lack of Cp increases neuronal susceptibility to ischemic injury by a mechanism that may involve reduced levels of iron and BDNF.
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Affiliation(s)
- Sarah J. Texel
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland, United States of America
| | - Jian Zhang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Simonetta Camandola
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland, United States of America
| | - Erica L. Unger
- Department of Nutrition Sciences, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Dennis D. Taub
- Laboratories of Immunology, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, United States of America
| | - Raymond C. Koehler
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Z. Leah Harris
- Department of Pediatrics, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Mark P. Mattson
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland, United States of America
- * E-mail:
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Darbar M, Emans SJ, Harris ZL, Brown NJ, Scott TA, Cooper WO. Part-time physician faculty in a pediatrics department: a study of equity in compensation and academic advancement. Acad Med 2011; 86:968-973. [PMID: 21694562 DOI: 10.1097/acm.0b013e318222317e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
PURPOSE To assess equity in compensation and academic advancement in an academic pediatrics department in which a large proportion of the physician faculty hold part-time appointments. METHOD The authors analyzed anonymized data from Vanderbilt University School of Medicine Department of Pediatrics databases for physician faculty (faculty with MD or MD/PhD degrees) employed during July 1, 2007 to June 30, 2008. The primary outcomes were total compensation and years at assistant professor rank. They compared compensation and years at junior rank by part-time versus full-time status, controlling for gender, rank, track, years since first appointment as an assistant professor, and clinical productivity. RESULTS Of the 119 physician faculty in the department, 112 met inclusion criteria. Among those 112 faculty, 23 (21%) were part-time and 89 (79%) were full-time faculty. Part-time faculty were more likely than full-time faculty to be women (74% versus 28%, P < .001) and married (100% versus 84%, P = .042). Analyses accounting for gender, years since first appointment, rank, clinical productivity, and track did not demonstrate significant differences in compensation by part-time versus full-time status. In other adjusted analyses, faculty with part-time appointments spent an average of 2.48 more years as an assistant professor than did faculty with full-time appointments. CONCLUSIONS Overall group differences in total compensation were not apparent in this department, but physician faculty with part-time appointments spent more time at the rank of assistant professor. This study provides a model for determining and analyzing compensation and effort to ensure equity and transparency across faculty.
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Affiliation(s)
- Mumtaz Darbar
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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Essley BV, McNanley T, Cooper E, McIntyre AW, Kent T, Witter F, Harris ZL, O'Brien KO. Vitamin D Status is Related to Placental Vitamin D Receptor (VDR) Expression and Fetal Growth in Pregnant Adolescents. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.990.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Tera Kent
- Nutritional SciencesCornell UniversityIthacaNY
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Hadziahmetovic M, Song Y, Wolkow N, Iacovelli J, Grieco S, Lee J, Lyubarsky A, Pratico D, Connelly J, Spino M, Harris ZL, Dunaief JL. The oral iron chelator deferiprone protects against iron overload-induced retinal degeneration. Invest Ophthalmol Vis Sci 2011; 52:959-68. [PMID: 21051716 DOI: 10.1167/iovs.10-6207] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
PURPOSE Iron-induced oxidative stress may exacerbate age-related macular degeneration (AMD). Ceruloplasmin/Hephaestin double-knockout (DKO) mice with age-dependent retinal iron accumulation and some features of AMD were used to test retinal protection by the oral iron chelator deferiprone (DFP). METHODS Cultured retinal pigment epithelial (ARPE-19) cells and mice were treated with DFP. Transferrin receptor mRNA (Tfrc), an indicator of iron levels, was quantified by qPCR. In mice, retinal oxidative stress was assessed by mass spectrometry, and degeneration by histology and electroretinography. RESULTS DFP at 60 μM decreased labile iron in ARPE-19 cells, increasing Tfrc and protecting 70% of cells against a lethal dose of H(2)O(2). DFP 1 mg/mL in drinking water increased retinal Tfrc mRNA 2.7-fold after 11 days and also increased transferrin receptor protein. In DKOs, DFP over 8 months decreased retinal iron levels to 72% of untreated mice, diminished retinal oxidative stress to 70% of the untreated level, and markedly ameliorated retinal degeneration. DFP was not retina toxic in wild-type (WT) or DKO mice, as assessed by histology and electroretinography. CONCLUSIONS Oral DFP was not toxic to the mouse retina. It diminished retinal iron levels and oxidative stress and protected DKO mice against iron overload-induced retinal degeneration. Further testing of DFP for retinal disease involving oxidative stress is warranted.
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Affiliation(s)
- Majda Hadziahmetovic
- F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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18
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Young MF, Griffin I, Pressman E, McIntyre AW, Cooper E, McNanley T, Harris ZL, Westerman M, O’Brien KO. Utilization of iron from an animal-based iron source is greater than that of ferrous sulfate in pregnant and nonpregnant women. J Nutr 2010; 140:2162-6. [PMID: 20980658 PMCID: PMC2981003 DOI: 10.3945/jn.110.127209] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [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] Open
Abstract
Heme iron absorption during pregnancy and the role of hepcidin in regulating dietary heme iron absorption remains largely unexplored. The objective of this research was to examine relative differences in heme (animal based) and nonheme (ferrous sulfate) iron utilization. This study was undertaken in 18 pregnant (ages 16-32 y; wk 32-35 of gestation) and 11 nonpregnant women (ages 18-27 y). Women were randomly assigned to receive both an animal-based heme meal (intrinsically labeled (58)Fe pork) and labeled ferrous sulfate ((57)Fe) fed on alternate days. Blood samples obtained 2 wk postdosing were used to assess iron status indicators and serum hepcidin and iron utilization based on RBC incorporation of iron isotopes. Heme iron utilization was significantly greater than nonheme iron utilization in the pregnant (47.7 ± 14.4 vs. 40.4 ± 13.2%) and nonpregnant women (50.1 ± 14.8 vs. 15.3 ± 9.7%). Among pregnant women, utilization of nonheme iron was associated with iron status, as assessed by the serum transferrin receptor concentration (P = 0.003; r(2) = 0.43). In contrast, heme iron utilization was not influenced by maternal iron status. In the group as a whole, women with undetectable serum hepcidin had greater nonheme iron utilization compared with women with detectable serum hepcidin (P = 0.02; n = 29); however, there were no significant differences in heme iron utilization. Our study suggests that iron utilization from an animal-based food provides a highly bioavailable source of dietary iron for pregnant and nonpregnant women that is not as sensitive to hepcidin concentrations or iron stores compared with ferrous sulfate.
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Affiliation(s)
- Melissa F. Young
- Cornell University, Division of Nutritional Sciences, Ithaca, NY 14853
| | - Ian Griffin
- USDA/Agricultural Research Service Children’s Nutrition Research Center, Baylor College of Medicine, Houston, TX 77030
| | - Eva Pressman
- The University of Rochester School of Medicine, Rochester, NY 14642
| | | | - Elizabeth Cooper
- The University of Rochester School of Medicine, Rochester, NY 14642
| | - Thomas McNanley
- The University of Rochester School of Medicine, Rochester, NY 14642
| | - Z. Leah Harris
- Vanderbilt University Medical Center, Department of Pediatrics, Nashville, TN 37232
| | | | - Kimberly O. O’Brien
- Cornell University, Division of Nutritional Sciences, Ithaca, NY 14853,To whom correspondence should be addressed: E-mail:
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Thompson-Torgerson CS, Champion HC, Santhanam L, Harris ZL, Shoukas AA. Cyclohexanone contamination from extracorporeal circuits impairs cardiovascular function. Am J Physiol Heart Circ Physiol 2009; 296:H1926-32. [PMID: 19411286 DOI: 10.1152/ajpheart.00184.2009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [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] [Indexed: 01/18/2023]
Abstract
Extracorporeal circulation provides critical life support in the face of cardiopulmonary or renal failure, but it also introduces a host of unique morbidities characterized by edema formation, cardiac insufficiency, autonomic dysfunction, and altered vasomotor function. We tested the hypothesis that cyclohexanone (CHX), a solvent used in production of extracorporeal circuits and intravenous (IV) bags, leaches into the contained fluids and can replicate these clinical morbidities. Crystalloid fluid samples from circuits and IV bags were analyzed by gas chromatography-mass spectrometry to provide a range of clinical CHX exposure levels, revealing CHX contamination of sampled fluids (9.63-3,694 microg/l). In vivo rat studies were conducted (n = 49) to investigate the effects of a bolus IV infusion of CHX vs. saline alone on cardiovascular function, baroreflex responsiveness, and edema formation. Cardiovascular function was evaluated by cardiac output, heart rate, stroke volume, vascular resistance, arterial pressure, and ventricular contractility. Baroreflex function was assessed by mean femoral arterial pressure responses to bilateral carotid occlusion. Edema formation was assessed by the ratio of wet to dry organ weights for lungs, liver, kidneys, and skin. CHX infusion led to systemic hypotension; pulmonary hypertension; depressed contractility, heart rate, stroke volume, and cardiac output; and elevated vascular resistance (P < 0.05). Mean arterial pressure responsiveness to carotid occlusion was dampened after CHX infusion (from +17.25 +/- 1.8 to +5.61 +/- 3.2 mmHg; P < 0.05). CHX infusion led to significantly higher wet-to-dry weight ratios vs. saline only (3.8 +/- 0.06 vs. 3.5 +/- 0.05; P < 0.05). CHX can reproduce clinical cardiovascular, neurological, and edema morbidities associated with extracorporeal circulatory treatment.
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Thompson‐Torgerson CS, Champion HC, Santhanam L, Harris ZL, Shoukas AA. Cyclohexanone contamination in extracorporeal circuits mimics cardiovascular elements of SIRS. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.lb76] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Lakshmi Santhanam
- Biomedical Engineering
- AnesthesiologyJohns Hopkins University School of MedicineBaltimoreMD
| | - Z. Leah Harris
- AnesthesiologyJohns Hopkins University School of MedicineBaltimoreMD
| | - Artin A. Shoukas
- Biomedical Engineering
- AnesthesiologyJohns Hopkins University School of MedicineBaltimoreMD
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21
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Hadziahmetovic M, Dentchev T, Song Y, Haddad N, He X, Hahn P, Pratico D, Wen R, Harris ZL, Lambris JD, Beard J, Dunaief JL. Ceruloplasmin/hephaestin knockout mice model morphologic and molecular features of AMD. Invest Ophthalmol Vis Sci 2008; 49:2728-36. [PMID: 18326691 DOI: 10.1167/iovs.07-1472] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Iron is an essential element in human metabolism but also is a potent generator of oxidative damage with levels that increase with age. Several studies suggest that iron accumulation may be a factor in age-related macular degeneration (AMD). In prior studies, both iron overload and features of AMD were identified in mice deficient in the ferroxidase ceruloplasmin (Cp) and its homologue hephaestin (Heph) (double knockout, DKO). In this study, the location and timing of iron accumulation, the rate and reproducibility of retinal degeneration, and the roles of oxidative stress and complement activation were determined. METHODS Morphologic analysis and histochemical iron detection by Perls' staining was performed on retina sections from DKO and control mice. Immunofluorescence and immunohistochemistry were performed with antibodies detecting activated complement factor C3, transferrin receptor, L-ferritin, and macrophages. Tissue iron levels were measured by atomic absorption spectrophotometry. Isoprostane F2alpha-VI, a specific marker of oxidative stress, was quantified in the tissue by gas chromatography/mass spectrometry. RESULTS DKOs exhibited highly reproducible age-dependent iron overload, which plateaued at 6 months of age, with subsequent progressive retinal degeneration continuing to at least 12 months. The degeneration shared some features of AMD, including RPE hypertrophy and hyperplasia, photoreceptor degeneration, subretinal neovascularization, RPE lipofuscin accumulation, oxidative stress, and complement activation. CONCLUSIONS DKOs have age-dependent iron accumulation followed by retinal degeneration modeling some of the morphologic and molecular features of AMD. Therefore, these mice are a good platform on which to test therapeutic agents for AMD, such as antioxidants, iron chelators, and antiangiogenic agents.
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Affiliation(s)
- Majda Hadziahmetovic
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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22
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Jehn ML, Guallar E, Clark JM, Couper D, Duncan BB, Ballantyne CM, Hoogeveen RC, Harris ZL, Pankow JS. A prospective study of plasma ferritin level and incident diabetes: the Atherosclerosis Risk in Communities (ARIC) Study. Am J Epidemiol 2007; 165:1047-54. [PMID: 17284722 DOI: 10.1093/aje/kwk093] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.5] [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: 11/13/2022] Open
Abstract
The authors performed a case-cohort study nested within the Atherosclerosis Risk in Communities (ARIC) Study to determine the association between plasma ferritin level and risk of type 2 diabetes mellitus. Persons with incident cases of type 2 diabetes diagnosed over an average follow-up period of 7.9 years (n = 599) were compared with a random sample of the cohort (n = 690). After adjustment for age, gender, menopausal status, ethnicity, center, smoking, and alcohol intake, the hazard ratio for diabetes, comparing the fifth quintile of ferritin with the first quintile, was 1.74 (95% confidence interval: 1.14, 2.65; p-trend < 0.001). After further adjustment for body mass index and components of the metabolic syndrome, the hazard ratio was 0.81 (95% confidence interval: 0.49, 1.34; p-trend = 0.87). From a causal perspective, there are two alternative interpretations of these findings. Elevated iron stores, reflected in elevated plasma ferritin levels, may induce baseline metabolic abnormalities that ultimately result in diabetes. Alternatively, elevated ferritin may be just one of several metabolic abnormalities related to the underlying process that ultimately results in diabetes, rather than a causal factor for diabetes. Longitudinal studies with repeated measurements of glucose and iron metabolism parameters are needed to establish the role of iron stores and plasma ferritin in diabetes development.
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Affiliation(s)
- Megan L Jehn
- Department of Epidemiology, Welch Center for Prevention, Epidemiology, and Clinical Research, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
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23
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McKee CT, Vricella LA, Harris ZL, Easley RB. Abdominal compartment syndrome contributing to failure of extracorporeal membrane oxygenation in an infant with congenital heart disease and sepsis. Pediatr Crit Care Med 2006; 7:180-2. [PMID: 16446598 DOI: 10.1097/01.pcc.0000201001.95499.be] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [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: 11/26/2022]
Abstract
OBJECTIVE To provide the first account of extracorporeal membrane oxygenation therapy failure secondary to abdominal compartment syndrome. DESIGN Case report. SETTING Pediatric intensive care unit. PATIENT A 4-month-old infant with cyanotic congenital heart disease and Escherichia coli sepsis developed abdominal distention and venous return failure on extracorporeal membrane oxygenation. INTERVENTION Emergency cardiac catheterization and atrial septectomy were performed. MAIN RESULTS Central venous pressure of 120 mm Hg was measured, confirming the diagnosis of abdominal compartment syndrome. CONCLUSIONS Abdominal compartment syndrome is a life-threatening condition resulting from an increase in intra-abdominal pressure that compromises abdominal organ perfusion, pulmonary function, and cardiac output. Mortality rates from abdominal compartment syndrome are as high as 60% in adults and children. This report of an infant with congenital heart disease and E. coli sepsis represents the first description of abdominal compartment syndrome that contributed to failure of extracorporeal membrane oxygenation and ultimately death. The pathophysiology, diagnosis, and treatment of abdominal compartment syndrome are also reviewed.
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Affiliation(s)
- Christopher T McKee
- Department of Anesthesiology and Critical Care, Johns Hopkins Medical Institute, Baltimore, MD, USA
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24
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Abstract
OBJECTIVE To describe lung isolation and the selective application of continuous positive airway pressure using an endobronchial blocker in a patient with sickle cell disease and unilateral necrotizing Clostridium perfringens pneumonia. DESIGN Case report. SETTING Pediatric intensive care unit. PATIENT A 12-yr-old male with sickle cell disease developed persistent necrotizing pneumonia of the left lung following exchange transfusion for acute chest syndrome and hyper-hemolytic syndrome. INTERVENTIONS An endobronchial blocker was placed into the left main stem bronchus for lung isolation and application of continuous positive airway pressure to the left lung for 48 hrs. MEASUREMENTS AND MAIN RESULTS After 14 days of persistent atelectasis of the left lung despite thorascopic decortication and multiple bronchoscopies, our patient had substantial lung aeration within 48 hrs of continuous positive airway pressure applied via the endobronchial blocker. Lung resection was avoided and the patient was successfully extubated 2 days after removal of the blocker. CONCLUSIONS This case report demonstrates a therapeutic application of prolonged lung isolation and differential ventilation in a patient with an airway too small for commercially available double-lumen endotracheal tubes. The apparent success of this intervention suggests the feasibility of selective ventilation in pediatric patients and highlights a novel application of the bronchial blocker.
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Affiliation(s)
- Ken M Brady
- Department of Anesthesiology/Critical Care Medicine and Pediatrics, Johns Hopkins Hospital, Baltimore, MD, USA
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25
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Cherukuri S, Potla R, Sarkar J, Nurko S, Harris ZL, Fox PL. Unexpected role of ceruloplasmin in intestinal iron absorption. Cell Metab 2005; 2:309-19. [PMID: 16271531 DOI: 10.1016/j.cmet.2005.10.003] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [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] [Received: 03/20/2005] [Revised: 07/10/2005] [Accepted: 10/12/2005] [Indexed: 02/07/2023]
Abstract
Ferroxidases are essential for normal iron homeostasis in most organisms. The paralogous vertebrate ferroxidases ceruloplasmin (Cp) and hephaestin (Heph) are considered to have nonidentical functions in iron transport: plasma Cp drives iron transport from tissue stores while intestinal Heph facilitates iron absorption from the intestinal lumen. To clarify the function of Cp, we acutely bled Cp-/- mice to stress iron homeostasis pathways. Red cell hemoglobin recovery was defective in stressed Cp-/- mice, consistent with low iron availability. Contrary to expectations, iron was freely released from spleen and liver stores in Cp-/- mice, but intestinal iron absorption was markedly impaired. Phlebotomy of wild-type mice caused a striking shift of Cp from the duodenal epithelium to the underlying lamina propria, suggesting a critical function of Cp in basolateral iron transport. Regulated relocalization of intestinal Cp may represent a fail-safe mechanism in which Cp shares with Heph responsibility for iron absorption under stress.
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Affiliation(s)
- Srujana Cherukuri
- Department of Cell Biology, The Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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Jehn ML, Guallar E, Harris ZL, Pankow JS. 214-S: Plasma Ferritin and Incident Type 2 Diabetes: The Atherosclerosis Risk in Communities (ARIC) Study. Am J Epidemiol 2005. [DOI: 10.1093/aje/161.supplement_1.s54a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- M L Jehn
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - E Guallar
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - Z L Harris
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
| | - J S Pankow
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD
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Hahn P, Dentchev T, Qian Y, Rouault T, Harris ZL, Dunaief JL. Immunolocalization and regulation of iron handling proteins ferritin and ferroportin in the retina. Mol Vis 2004; 10:598-607. [PMID: 15354085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
Abstract
PURPOSE CNS iron accumulation is associated with several neurodegenerative diseases, including age-related macular degeneration. Intracellular overload of free iron is prevented, in part, by the iron export protein, ferroportin, and the iron storage protein, ferritin. The purpose of this study was to assess retinal localization and regulation of ferroportin and ferritin. METHODS Normal murine retinas were analyzed by immunohistochemistry to localize ferroportin, cytosolic ferritin, and mitochondrial ferritin, with double-labeling using cell-specific markers to identify cell types. Retinas deficient in the ferroxidases, ceruloplasmin and hephaestin, accumulate iron in their retinas and RPE, while retinas deficient in iron regulatory proteins (IRPs) lack the ability to regulate several proteins involved in iron metabolism; retinas from these knockout mice along with their age matched wild type littermates were also examined to study regulation of ferritin and ferroportin. To enable visualization of label in the retinal pigment epithelial cells, sections from pigmented mice were bleached with H2O2 prior to IHC, a novel use of this technique for study of the RPE. RESULTS In normal retinas, cytosolic ferritins were found predominantly in rod bipolar cells and photoreceptors. Ferroportin was found in RPE and Müller cells. Iron accumulation in mice deficient in ceruloplasmin and hephaestin was associated with upregulation of ferritin and ferroportin. Mice deficient in IRPs showed upregulation of ferritin and ferroportin, likely because of their inability to repress translation. CONCLUSIONS Normal retinas contain ferritin and ferroportin, whose levels are regulated by iron-responsive, iron regulatory proteins. Ferroportin colocalizes with ceruloplasmin and hephaestin to RPE and Müller cells, supporting a potential cooperation between these ferroxidases and the iron exporter. Cytosolic ferritin accumulates in rod bipolar synaptic terminals, suggesting that ferritin may be involved in axonal iron transport. Mitochondrial ferritin increases with iron accumulation, suggesting a role in iron storage.
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Affiliation(s)
- Paul Hahn
- F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Philadelphia, PA, USA
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Bradley J, Leibold EA, Harris ZL, Wobken JD, Clarke S, Zumbrennen KB, Eisenstein RS, Georgieff MK. Influence of gestational age and fetal iron status on IRP activity and iron transporter protein expression in third-trimester human placenta. Am J Physiol Regul Integr Comp Physiol 2004; 287:R894-901. [PMID: 15178542 DOI: 10.1152/ajpregu.00525.2003] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [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
Placental iron transport during the last trimester of pregnancy determines the iron endowment of the neonate. Iron transport is a function of the major iron transport proteins: transferrin receptor-1 (TfR-1) and ferroportin-1 (FPN-1). The mRNAs for TfR-1 and, potentially, FPN-1 are posttranscriptionally regulated by iron regulatory protein (IRP)-1 and IRP-2. We assessed the effect of gestational age and fetal iron status on IRP-1- and IRP-2-binding activity and on the localization and protein expression of TfR-1 and FPN-1 protein at 24-40 wk of gestation in 21 placentas obtained from iron-sufficient nonanemic mothers. Gestational age had no effect on cord serum ferritin concentration, IRP-2 RNA-binding activity, transporter protein location, and TfR-1 or FPN-1 protein expression. IRP-1 activity remained constant until full term, when it decreased (P = 0.01). Placental ferritin (r = 0.76, P < 0.001) and FPN-1 (r = 0.44, P < 0.05) expression increased with gestational age. Fetal iron status, as indexed by cord serum ferritin concentration, was inversely related to placental IRP-1 (r = -0.66, P < 0.001) and IRP-2 (r = -0.42, P = 0.05) activities. Placental ferritin protein expression correlated better with IRP-1 (r = -0.45, P = 0.04) than with IRP-2 (r = -0.35, P = 0.10) activity. Placental TfR-1 and FPN-1 protein expression was independent of fetal or placental iron status and IRP activities. Iron status had no effect on transport protein localization. We conclude that, toward the end of the third trimester of iron-sufficient human pregnancy, the placenta accumulates ferritin and potentially increases placental-fetal iron delivery through increased FPN-1 expression. IRP-1 may have a more dominant role than IRP-2 activity in regulating ferritin expression.
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Affiliation(s)
- Jenni Bradley
- University of Minnesota, Mayo Mail Code 39, 420 Delaware St. SE, Minneapolis, MN 55455, USA
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Xu X, Pin S, Gathinji M, Fuchs R, Harris ZL. Aceruloplasminemia: an inherited neurodegenerative disease with impairment of iron homeostasis. Ann N Y Acad Sci 2004; 1012:299-305. [PMID: 15105274 DOI: 10.1196/annals.1306.024] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In 1987, Miyajima et al. first characterized an autosomal recessive, adult-onset neurodegenerative disorder resembling Parkinson's disease associated with near-absent circulating serum ceruloplasmin levels. Coined "familial apoceruloplasmin deficiency", they described a patient with a presenting triad of diabetes mellitus, retinal degeneration, and neurodegeneration with blepharospasm. Neuropathological evaluation revealed abundant iron deposition in selected neurons of the basal ganglia and substantia nigra with associated neuronal dropout and spongioform degeneration without evidence of reactive gliosis. Subsequently, mutations in the ceruloplasmin gene have been determined to result in the excessive iron accumulation seen in the pancreas, retina, and brain. Elevated serum ferritin suggests a systemic iron overload syndrome, yet affected patients had low transferrin saturation and a mild anemia. This new disease, "aceruloplasminemia", reveals a role for ceruloplasmin as an essential ferroxidase critical for iron homeostasis. This multicopper oxidase promotes efficient iron efflux such that individuals lacking ceruloplasmin develop a presumed oxidative injury secondary to iron accumulation and significant neuronal damage. Aceruloplasminemic mice provide a valuable model to further study the mechanisms by which ceruloplasmin regulates iron trafficking and the role of iron in oxidative injury. Despite the dependence of ceruloplasmin on copper for its function, aceruloplasminemia represents an iron storage disease and not a defect in copper metabolism. However, recent evidence in Saccharomyces cerevisiae indicates that Fet3, the yeast homologue of ceruloplasmin, functions as an essential cuprous oxidase. Further investigation into the mechanisms by which ceruloplasmin regulates iron and copper homeostasis will provide valuable insight into the pathogenesis of metallo-mediated diseases and elucidate mechanisms for transition metal (copper, iron) neuropathology.
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Affiliation(s)
- Xueying Xu
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Hospital and School of Medicine, Baltimore, Maryland 21287, USA
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Abstract
Mutations that lead to a loss of the copper-containing plasma enzyme ceruloplasmin disrupt mammalian iron homeostasis. The mechanism by which ceruloplasmin mobilizes iron from cell stores has been controversial. We demonstrate that injection of a soluble copper-containing yeast protein Fet3p can restore iron homeostasis in phlebotomized mice with a deletion of the ceruloplasmin gene. These results show the conservation of function of copper-containing proteins in eukaryotic iron metabolism.
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Affiliation(s)
- Z Leah Harris
- Department of Anesthesiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Abstract
Genetic defects in copper metabolism highlight the delicate balance mammalian systems have developed to maintain normal copper homeostasis. Menkes disease, the mottled mouse, the Atox-1-deficient mouse and the ctr1 knockout mouse reveal the importance of adequate copper intake during embryogenesis and early development, especially in the central nervous system. The toxicity associated with excess copper as manifest in Wilson disease, the toxic milk mouse, the LEC rat and copper toxicosis in the Bedlington terrier demonstrate the profound cellular susceptibility to copper overload, in particular, in the brain and liver. Ceruloplasmin (Cp) contains 95% of the copper found in human serum, and inherited loss of this protein results in diabetes, retinal degeneration and neurodegeneration. Despite normal copper metabolism, aceruloplasminemic patients and the Cp knockout mouse have disturbed iron homeostasis and mild hepatic copper retention. These genetic disorders of copper metabolism provide valuable insight into the mechanisms regulating copper homeostasis and models to further dissect the role of this essential metal in health and disease.
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Affiliation(s)
- Hoon Shim
- Department of Anesthesiology, The Johns Hopkins University and School of Medicine, Baltimore, MD, USA
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Affiliation(s)
- Z Leah Harris
- Division of Pediatric Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Blalock 904B, Baltimore, MD 21287, USA.
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Harris ZL. Not all absent serum ceruloplasmin is Wilson disease: a review of aceruloplasminemia. J Investig Med 2002; 50:236S-238S. [PMID: 12227652 DOI: 10.2310/6650.2002.32963] [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] [Indexed: 11/18/2022]
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Abstract
Because it can undergo reversible changes in oxidation state, iron is an excellent biocatalyst but also a potentially deleterious metal. Iron-mediated toxicity has been ascribed to Fe(II), which reacts with oxygen to generate free radicals that damage macromolecules and cause cell death. However, we now report that Fe(III) exhibits microbicidal activity towards strains of Salmonella enterica, Escherichia coli and Klebsiella pneumoniae defective in the Fe(III)-responding PmrA/PmrB signal transduction system. Fe(III) bound to a pmrA Salmonella mutant more effectively than to the isogenic wild-type strain and exerted its microbicidal activity even under anaerobic conditions. Moreover, Fe(III) permeabilized the outer membrane of the pmrA mutant, rendering it susceptible to vancomycin, which is normally non-toxic to Gram-negative species. On the other hand, Fe(III) did not affect the viability of a mutant defective in Fur, the major regulator of cytosolic iron homeostasis, which is hypersensitive to Fe(II)-mediated toxicity. A functional pmrA gene was necessary for bacterial survival in soil. Our results indicate that Fe(III) exerts its microbicidal activity by a mechanism that is oxygen independent and different from that mediated by Fe(II).
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Affiliation(s)
- Sangpen Chamnongpol
- Department of Molecular Microbiology, Howard Hughes Medical Institute, Washington University School of Medicine, St Louis, MO 63110, USA
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Abstract
Ceruloplasmin is an abundant serum glycoprotein containing greater than 95% of the copper found in the plasma of vertebrate species. Although this protein is known to function as an essential ferroxidase, the role of ceruloplasmin in copper transport and metabolism remains unclear. To elucidate the role of ceruloplasmin in copper metabolism, the kinetics of copper absorption, transport, distribution, and excretion were examined utilizing (64)Cu in wild-type and aceruloplasminemic mice. No differences in gastrointestinal absorption, hepatic uptake, or biliary excretion were observed in these animals. Furthermore, steady state measurements of tissue copper content utilizing (64)Cu and atomic absorption spectroscopy revealed no differences in the copper content of the brain, heart, spleen, and kidney. Consistent with these findings, the activity of copper-zinc superoxide dismutase in these tissues was equivalent in wild-type and ceruloplasmin-deficient mice. Hepatic iron was elevated 3.5-fold in aceruloplasminemic mice because of the loss of ferroxidase function. Hepatic copper content was markedly increased in aceruloplasminemic mice. As no differences were observed in copper absorption or biliary copper excretion, these data suggest that in these animals, hepatocyte copper intended for ceruloplasmin incorporation is trafficked into a compartment that is less available for biliary copper excretion. Taken together, these data reveal no essential role for ceruloplasmin in copper metabolism and suggest a previously unappreciated complexity to the subcellular distribution of this metal within the hepatocyte secretory pathway.
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Affiliation(s)
- L A Meyer
- Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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Abstract
Aceruloplasminemia is an autosomal recessive disorder of iron metabolism. Affected individuals evidence iron accumulation in tissue parenchyma in association with absent serum ceruloplasmin. Genetic studies of such patients reveal inherited mutations in the ceruloplasmin gene. To elucidate the role of ceruloplasmin in iron homeostasis, we created an animal model of aceruloplasminemia by disrupting the murine ceruloplasmin (Cp) gene. Although normal at birth, Cp(-/-) mice demonstrate progressive accumulation of iron such that by one year of age all animals have a prominent elevation in serum ferritin and a 3- to 6-fold increase in the iron content of the liver and spleen. Histological analysis of affected tissues in these mice shows abundant iron stores within reticuloendothelial cells and hepatocytes. Ferrokinetic studies in Cp(+/+) and Cp(-/-) mice reveal equivalent rates of iron absorption and plasma iron turnover, suggesting that iron accumulation results from altered compartmentalization within the iron cycle. Consistent with this concept, Cp(-/-) mice showed no abnormalities in cellular iron uptake but a striking impairment in the movement of iron out of reticuloendothelial cells and hepatocytes. Our findings reveal an essential physiologic role for ceruloplasmin in determining the rate of iron efflux from cells with mobilizable iron stores.
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Affiliation(s)
- Z L Harris
- Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
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Abstract
Aceruloplasminemia is an autosomal recessive disorder characterized by progressive neurodegeneration of the retina and basal ganglia associated with specific inherited mutations in the ceruloplasmin gene. Clinical and pathologic studies in patients with aceruloplasminemia revealed a marked accumulation of iron in affected parenchymal tissues, a finding consistent with early work identifying ceruloplasmin as a ferroxidase and with recent findings showing an essential role for a homologous copper oxidase in iron metabolism in yeast. The presence of neurologic symptoms in aceruloplasminemia is unique among the known inherited and acquired disorders of iron metabolism; recent studies revealed an essential role for astrocyte-specific expression of ceruloplasmin in iron metabolism and neuronal survival in the central nervous system. Recognition of aceruloplasminemia provides new insights into the genetic and environmental determinants of copper metabolism and has important implications for our understanding of the role of copper in human neurodegenerative diseases.
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Affiliation(s)
- Z L Harris
- Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, USA
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Abstract
Recent studies resulted in the cloning of the genes responsible for Menkes syndrome and Wilson disease. Despite the distinct clinical phenotypes of these disorders, each gene encodes a highly homologous member of the cation-transport P-type ATPase family. The remarkable evolutionary conservation of these proteins in bacteria, yeast, plants, and mammals reveals a fundamental protein structure essential for copper export in all life forms. Characterization of a molecular defect in the rat homologue of the Wilson ATPase in the Long-Evans Cinnamon rat identifies an animal model of Wilson disease and will permit experimental analysis of the precise role of this ATPase in copper transport, the effects of specific inherited mutations on transport function, and the cellular and molecular mechanisms of tissue injury resulting from copper accumulation. Finally, recent molecular genetic analysis of a distinct group of patients with low serum ceruloplasmin and basal ganglia symptoms identified a series of mutations in the ceruloplasmin gene. The presence of these mutations in conjunction with the clinical and pathologic findings clarifies the essential biological role of this abundant copper protein in metal metabolism and identifies aceruloplasminemia as a novel autosomal recessive disorder of iron metabolism.
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Affiliation(s)
- Z L Harris
- Department of Pediatrics, Washington University School of Medicine, St Louis, MO 63110, USA
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Abstract
Exposure of rats to hyperoxia is associated with increased active Na+ transport in rat lungs and increased Na,K-adenosine triphosphate (ATPase) expression in alveolar epithelial cells. Hyperbaric oxygenation (HBO) has been reported to act as an accelerated model of hyperoxic cell damage. Sublethal and intermittent exposure to HBO, however, has been suggested to upregulate endogenous protective mechanisms. In the present study, we tested whether short-term HBO, prior to inducing lung injury, would upregulate lung Na,K-ATPase. The results show that HBO, either intermittent or single 2.5 h exposure, increased lung Na,K-ATPase alpha-1 and beta-1 messenger ribonucleic acid (mRNA) transcript levels up to fourfold. Na,K-ATPase activity in lungs of rats exposed to HBO increased twofold during the first 2 h following removal from the hyperbaric chamber, and remained elevated for up to 6 h following HBO. Conceivably, the increase in Na,K-ATPase activity following HBO is due to an increase in activity from a basal to a higher rate, or possibly due to recruitment/translocation of Na,K-ATPases from inner membranes to the plasma membrane.
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Affiliation(s)
- Z L Harris
- Michael Reese Hospital, Chicago, IL, USA
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Harris ZL, Takahashi Y, Miyajima H, Serizawa M, MacGillivray RT, Gitlin JD. Aceruloplasminemia: molecular characterization of this disorder of iron metabolism. Proc Natl Acad Sci U S A 1995; 92:2539-43. [PMID: 7708681 PMCID: PMC42253 DOI: 10.1073/pnas.92.7.2539] [Citation(s) in RCA: 369] [Impact Index Per Article: 12.7] [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: 01/26/2023] Open
Abstract
Ceruloplasmin is an abundant alpha 2-serum glycoprotein that contains 95% of the copper found in the plasma of vertebrate species. We report here on the identification of a genetic defect in the ceruloplasmin gene in a patient previously noted to have a total absence of circulating serum ceruloplasmin in association with late-onset retinal and basal ganglia degeneration. In this patient T2 (transverse relaxation time)-weighted magnetic resonance imaging of the brain revealed basal ganglia densities consistent with iron deposition, and liver biopsy confirmed the presence of excess iron. Although Southern blot analysis of the patient's DNA was normal, PCR amplification of 18 of the 19 exons composing the human ceruloplasmin gene revealed a distinct size difference in exon 7. DNA sequence analysis of this exon revealed a 5-bp insertion at amino acid 410, resulting in a frame-shift mutation and a truncated open reading frame. The validity of this mutation was confirmed by analysis of DNA from the patient's daughter, which revealed heterozygosity for this same 5-bp insertion. The presence of this mutation in conjunction with the clinical and pathologic findings demonstrates an essential role for ceruloplasmin in human biology and identifies aceruloplasminemia as an autosomal recessive disorder of iron metabolism. These findings support previous studies that identified ceruloplasmin as a ferroxidase and are remarkably consistent with recent studies on the essential role of a homologous copper oxidase in iron metabolism in yeast. The clinical and laboratory findings suggest that additional patients with movement disorders and nonclassical Wilson disease should be examined for ceruloplasmin gene mutations.
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Affiliation(s)
- Z L Harris
- Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St. Louis, MO 63110, USA
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Sznajder JI, Ridge KM, Harris ZL, Olivera W, Curiel C, Rutschman DH. Alveolar type II cell Na,K-ATPase is upregulated during mechanical ventilation-induced pulmonary edema. Chest 1994; 105:116S-117S. [PMID: 8131602 DOI: 10.1378/chest.105.3_supplement.116s] [Citation(s) in RCA: 10] [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: 01/29/2023] Open
Affiliation(s)
- J I Sznajder
- Department of Medicine, Michael Reese Hospital, Chicago 60612
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Carter CS, Witt DM, Schneider J, Harris ZL, Volkening D. Male stimuli are necessary for female sexual behavior and uterine growth in prairie voles (Microtus ochrogaster). Horm Behav 1987; 21:74-82. [PMID: 3549517 DOI: 10.1016/0018-506x(87)90032-8] [Citation(s) in RCA: 97] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In reproductively naive female prairie voles (Microtus ochrogaster) direct contact with male urine or housing in a male-soiled cage, in the absence of physical contact, resulted in increased uterine weights, but did not reliably elicit behavioral estrus (defined by lordosis). Physical contact with an unfamiliar male, for 1 hr or more, followed by 30 or 48 hr of continuous access to a male-soiled cage, induced lordosis in approximately two-thirds of the females tested. When females were physically exposed to a male for 18 hr and tested 6 hr later, 70% showed lordosis. However, when females receiving either 1 or 18 hr of male contact were removed from the presence of the male and placed in a clean cage for 24 hr, only 29-37% of the females subsequently showed lordosis. These results suggest that direct physical contact with the male or chemical stimuli from the male may be necessary to induce and maintain behavioral estrus in female prairie voles.
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