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Nossa G, Monsivais H, Lee CG, Francis G, Wells EM, Park JH, Dydak U. Do toenail manganese and iron levels reflect brain metal levels or brain metabolism in welders? Neurotoxicology 2024; 104:45-55. [PMID: 39002648 DOI: 10.1016/j.neuro.2024.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 06/14/2024] [Accepted: 07/10/2024] [Indexed: 07/15/2024]
Abstract
Inhalation of welding fumes can cause metal accumulation in the brain, leading to Parkinsonian-like symptoms. Metal accumulation and altered neurochemical profiles have been observed using magnetic resonance imaging (MRI) in highly exposed welders, being associated with decreased motor function and cognition. While MRI is impractical to use as a health risk assessment tool in occupational settings, toenail metal levels are easier to assess and have been demonstrated to reflect an exposure window of 7-12 months in the past. Yet, it is unclear whether toenail metal levels are associated with brain metal levels or changes in metabolism, which are the root of potential health concerns. This study investigates whether toenail manganese (Mn) and iron (Fe) levels, assessed at several time points, correlate with brain Mn and Fe levels, measured by MRI, as well as brain GABA, glutamate (Glu), and glutathione (GSH) levels, measured by Magnetic Resonance Spectroscopy (MRS), in seventeen Mn-exposed welders. Quantitative T1 and R2* MRI maps of the whole brain, along with GABA, Glu, and GSH MRS measurements from the thalamus and cerebellum were acquired at baseline (T0). Toenail clippings were collected at T0 and every three months after the MRI for a year to account for different exposure periods being reflected by toenail clippings and MRI. Spearman correlations of toenail metal levels were run against brain metal and metabolite levels, but no significant associations were found for Mn at any timepoint. Cerebellar GSH positively correlated with toenail Fe clipped twelve months after the MRI (p = 0.05), suggesting an association with Fe exposure at the time of the MRI. Neither thalamic GABA nor Glu correlated with toenail Fe levels. In conclusion, this study cannot support toenail Mn as a proxy for brain Mn levels or metabolic changes, while toenail Fe appears linked to brain metabolic alterations, underscoring the importance of considering other metals, including Fe, in studying Mn neurotoxicity.
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Affiliation(s)
- Gianna Nossa
- School of Health Sciences, Purdue University, West Lafayette, IN, United States
| | - Humberto Monsivais
- School of Health Sciences, Purdue University, West Lafayette, IN, United States
| | - Chang Geun Lee
- School of Health Sciences, Purdue University, West Lafayette, IN, United States
| | - Grace Francis
- School of Health Sciences, Purdue University, West Lafayette, IN, United States
| | - Ellen M Wells
- School of Health Sciences, Purdue University, West Lafayette, IN, United States; Department of Public Health, Purdue University, West Lafayette, IN, United States
| | - Jae Hong Park
- School of Health Sciences, Purdue University, West Lafayette, IN, United States
| | - Ulrike Dydak
- School of Health Sciences, Purdue University, West Lafayette, IN, United States; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States.
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2
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Alikunju M, Misiriyyah N, Sayeed Iqbal S, Khan M. Manganese Neurotoxicity as a Stroke Mimic: A Case Report. Cureus 2023; 15:e37247. [PMID: 37168188 PMCID: PMC10166376 DOI: 10.7759/cureus.37247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2023] [Indexed: 05/13/2023] Open
Abstract
Manganese (Mn)-induced cerebral toxicity is a rare neurological condition that can present as a stroke mimic in high-risk populations. We present a case of a 40-year-old male with no known comorbidities who was brought to the emergency department with complaints of nonprogressive slurred speech and left facial weakness for eight days. Further history revealed that he had been working as a welder in a steel factory for the past seven years without using proper personal protective equipment (PPE). On physical examination, an upper motor neuron (UMN) type weakness on the left side of his face and spastic dysarthria could be appreciated. Following a brain computed tomography (CT) scan that showed ill-defined hypodensities in the basal ganglia without any signs of a hemorrhage, he was admitted to the stroke unit for conservative management and further investigations. A magnetic resonance imaging (MRI) scan of the brain done later showed features of manganese deposition and absorption in the globus pallidus and corticospinal tracts, indicating a diagnosis of manganese-induced cerebral toxicity. His serum manganese levels obtained during admission were normal. He was managed conservatively with intravenous rehydration and was discharged after symptomatic improvement. He was counseled and educated regarding the importance of wearing protective equipment while at work to reduce further exposure to the metal. During his follow-up visit, his symptoms had considerably improved with proper adherence to workplace safety measures.
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3
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Kwong AJ, Zahr NM. Serum biomarkers of liver fibrosis identify globus pallidus vulnerability. Neuroimage Clin 2023; 37:103333. [PMID: 36868044 PMCID: PMC9996367 DOI: 10.1016/j.nicl.2023.103333] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 01/12/2023] [Accepted: 01/19/2023] [Indexed: 01/28/2023]
Abstract
The CNS manifestation of chronic liver disease can include magnetic resonance (MR) signal hyperintensities in basal ganglia structures. Here, relations between liver (serum-derived fibrosis scores) and brain (regional T1-weighted signal intensities and volumes) integrity were evaluated in a sample of 457 individuals including those with alcohol use disorders (AUD), people living with human immunodeficiency virus (HIV), those comorbid for AUD and HIV, and healthy controls. Liver fibrosis was identified from cutoff scores as follows: aspartate aminotransferase to platelet ratio index (APRI) > 0.7 in 9.4% (n = 43) of the cohort; fibrosis score (FIB4) > 1.5 in 28.0% (n = 128) of the cohort; and non-alcoholic fatty liver disease fibrosis score (NFS) > -1.4 in 30.2% (n = 138) of the cohort. Presence of serum-derived liver fibrosis was associated with high signal intensities selective to basal ganglia (i.e., caudate, putamen, and pallidum) structures. High signal intensities in the pallidum, however, explained a significant portion of the variance in APRI (25.0%) and FIB4 (23.6%) cutoff scores. Further, among the regions evaluated, only the globus pallidus showed a correlation between greater signal intensity and smaller volume (r = -0.44, p <.0001). Finally, higher pallidal signal intensity correlated worse ataxia (eyes open ρ = -0.23, p =.0002; eyes closed ρ = -0.21, p =.0005). This study suggests that clinically relevant serum biomarkers of liver fibrosis such as the APRI may identify individuals vulnerable to globus pallidus pathology and contribute to problems with postural balance.
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Affiliation(s)
- Allison J Kwong
- Division of Gastroenterology and Hepatology, Department of Medicine, Stanford University, School of Medicine, Redwood City, CA 94063, USA
| | - Natalie M Zahr
- Department of Psychiatry & Behavioral Sciences, Stanford University, School of Medicine, 401 Quarry Rd. Stanford, CA 94305, USA; Neuroscience Program, SRI International, Menlo Park, CA 94025, USA.
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4
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Karyakina NA, Shilnikova N, Farhat N, Ramoju S, Cline B, Momoli F, Mattison D, Jensen N, Terrell R, Krewski D. Biomarkers for occupational manganese exposure. Crit Rev Toxicol 2022; 52:636-663. [PMID: 36705643 DOI: 10.1080/10408444.2022.2128718] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Long-term inhalation exposure to manganese (Mn) metal or its inorganic compounds can result in manganism or subclinical neurofunctional deficits. Studies have described affected workers in Mn dioxide mining, Mn-containing ore crushing and milling facilities, manufacturing of dry-cell batteries, Mn steel and alloy production plants, and in welders. The objective of this study was to critically review existing evidence on the reliability of potential biomarkers of Mn exposure, specifically the relationship between inhalation exposure to Mn particulates in different occupational settings and Mn concentrations in blood and other biological fluids and tissues, with a particular focus on whole blood as a potentially useful medium for measuring internal tissue dose. We also examined available evidence on the relationship between Mn levels in blood and adverse clinical and subclinical neurotoxic outcomes. Three bibliographic databases were searched for relevant studies and identified references were screened by two independent reviewers. Of the 6338 unique references identified, 76 articles were retained for data abstraction. Findings indicate that the relationships between Mn in blood and both external Mn exposure indices and neurofunctional impairments are limited and inconsistent. Different sources of exposure to Mn compounds, heterogeneity in the methodological approaches, and inadequate reporting of essential information limited direct comparison of the reported findings. Among the Mn-exposure biomarkers considered in this review - including biomarkers in blood, plasma, serum, erythrocytes, urine, bone, toenails, fingernails, hair, saliva - biomarkers in whole blood may provide to be most useful in Mn biomonitoring and risk assessment.
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Affiliation(s)
- Nataliya A Karyakina
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada
| | - Natalia Shilnikova
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada
| | - Nawal Farhat
- Risk Sciences International, Ottawa, Canada.,School of Mathematics and Statistics, Carleton University, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | | | | | - Franco Momoli
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - Donald Mattison
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada.,Arnold School of Public Health, University of South Carolina, Columbia, SC, USA
| | - N Jensen
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - R Terrell
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - Daniel Krewski
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada.,School of Mathematics and Statistics, Carleton University, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
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5
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Jensen N, Terrell R, Ramoju S, Shilnikova N, Farhat N, Karyakina N, Cline BH, Momoli F, Mattison D, Krewski D. Magnetic resonance imaging T1 indices of the brain as biomarkers of inhaled manganese exposure. Crit Rev Toxicol 2022; 52:358-370. [PMID: 36412542 DOI: 10.1080/10408444.2022.2128719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Excessive exposure to manganese (Mn) is linked to its accumulation in the brain and adverse neurological effects. Paramagnetic properties of Mn allow the use of magnetic resonance imaging (MRI) techniques to identify it in biological tissues. A critical review was conducted to evaluate whether MRI techniques could be used as a diagnostic tool to detect brain Mn accumulation as a quantitative biomarker of inhaled exposure. A comprehensive search was conducted in MEDLINE, EMBASE, and PubMed to identify potentially relevant studies published prior to 9 May 2022. Two reviewers independently screened identified references using a two-stage process. Of the 6452 unique references identified, 36 articles were retained for data abstraction. Eligible studies used T1-weighted MRI techniques and reported direct or indirect T1 measures to characterize Mn accumulation in the brain. Findings demonstrate that, in subjects exposed to high levels of Mn, deposition in the brain is widespread, accumulating both within and outside the basal ganglia. Available evidence indicates that T1 MRI techniques can be used to distinguish Mn-exposed individuals from unexposed. Additionally, T1 MRI may be useful for semi-quantitative evaluation of inhaled Mn exposure, particularly when interpreted along with other exposure indices. T1 MRI measures appear to have a nonlinear relationship to Mn exposure duration, with R1 signal only increasing after critical thresholds. The strength of the association varied depending on the regions of interest imaged and the method of exposure measurement. Overall, available evidence suggests potential for future clinical and risk assessment applications of MRI as a diagnostic tool.
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Affiliation(s)
- N Jensen
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - R Terrell
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - S Ramoju
- Risk Sciences International, Ottawa, Canada
| | - N Shilnikova
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada
| | - N Farhat
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada.,School of Mathematics and Statistics, Carleton University, Ottawa, Canada
| | - N Karyakina
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada
| | - B H Cline
- International Manganese Institute, Paris, France
| | - F Momoli
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - D Mattison
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada.,Arnold School of Public Health, University of South Carolina, Columbia, SC, USA
| | - D Krewski
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada.,School of Mathematics and Statistics, Carleton University, Ottawa, Canada
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6
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Wang X, Li R, He R, Fang F. Effects of repeated manganese treatment on proton magnetic resonance spectra of the globus pallidus in rat brain. NMR IN BIOMEDICINE 2022; 35:e4617. [PMID: 34562038 DOI: 10.1002/nbm.4617] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 08/25/2021] [Accepted: 08/29/2021] [Indexed: 06/13/2023]
Abstract
Excessive manganese is neurotoxic, which means that it can affect the concentrations of metabolite in 1 H MRS. In addition, manganese is paramagnetic and it may influence the relaxation times of the metabolite. The aim of this study is to assess the sensitivity of the metabolite relaxation properties and concentrations to exogenous manganese deposition in the globus pallidus (GP) of rat brain after repeated manganese injection. Proton magnetic resonance spectroscopy (1 H MRS) experiments in vivo and ex vivo were carried out to evaluate the changes in the metabolite concentration and the major metabolite relaxation times, and histological experiments were also performed after repeated manganese administration. Only the T1 value for N-acetylaspartate (NAA) of the GP was significantly reduced after 1 day of manganese injection compared with that of the control group (p < 0.025). The T1 and T2 values for NAA and total creatine (tCr) (p < 0.025), along with the amounts of NAA, tCr, myo-inositol, choline, and glutamate (p < 0.0086) in the GP, were all significantly decreased after 5 days of manganese administration compared with that of the control group. The changes in the concentration and relaxation properties of NAA and tCr in the GP of rat brain indicated that manganese represented paramagnetism and neurotoxicity after repeated administration. Accurate knowledge of relaxation properties and concentrations of NAA and tCr in this study could help appropriate selection of sequence parameters to improve the ability to distinguish the brain regions affected in cases of manganese poisoning.
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Affiliation(s)
- Xuxia Wang
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ronghui Li
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, China
| | - Rui He
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, China
| | - Fang Fang
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, China
- University of Chinese Academy of Sciences, Beijing, China
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7
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de Prado Bert P, Mercader EMH, Pujol J, Sunyer J, Mortamais M. The Effects of Air Pollution on the Brain: a Review of Studies Interfacing Environmental Epidemiology and Neuroimaging. Curr Environ Health Rep 2019; 5:351-364. [PMID: 30008171 PMCID: PMC6132565 DOI: 10.1007/s40572-018-0209-9] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Purpose of Review An emerging body of evidence has raised concern regarding the potentially harmful effects of inhaled pollutants on the central nervous system during the last decade. In the general population, traffic-related air pollution (TRAP) exposure has been associated with adverse effects on cognitive, behavior, and psychomotor development in children, and with cognitive decline and higher risk of dementia in the elderly. Recently, studies have interfaced environmental epidemiology with magnetic resonance imaging to investigate in vivo the effects of TRAP on the human brain. The aim of this systematic review was to describe and synthesize the findings from these studies. The bibliographic search was carried out in PubMed with ad hoc keywords. Recent Findings The selected studies revealed that cerebral white matter, cortical gray matter, and basal ganglia might be the targets of TRAP. The detected brain damages could be involved in cognition changes. Summary The effect of TRAP on cognition appears to be biologically plausible. Interfacing environmental epidemiology and neuroimaging is an emerging field with room for improvement. Future studies, together with inputs from experimental findings, should provide more relevant and detailed knowledge about the nature of the relationship between TRAP exposure and cognitive, behavior, and psychomotor disorders observed in the general population.
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Affiliation(s)
| | | | - Jesus Pujol
- MRI Research Unit, Department of Radiology, Hospital del Mar, Barcelona, Spain
- Centro Investigación Biomédica en Red de Salud Mental, CIBERSAM G21, Barcelona, Spain
| | - Jordi Sunyer
- Pompeu Fabra University, Barcelona, Catalonia, Spain
- ISGLOBAL, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain
- Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
- Institut Hospital del Mar d'Investigacions Mèdiques-Parc de Salut Mar, Barcelona, Catalonia, Spain
| | - Marion Mortamais
- Pompeu Fabra University, Barcelona, Catalonia, Spain.
- ISGLOBAL, Centre for Research in Environmental Epidemiology (CREAL), Barcelona, Spain.
- Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain.
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8
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Chen P, Totten M, Zhang Z, Bucinca H, Erikson K, Santamaría A, Bowma AB, Aschner M. Iron and manganese-related CNS toxicity: mechanisms, diagnosis and treatment. Expert Rev Neurother 2019; 19:243-260. [PMID: 30759034 PMCID: PMC6422746 DOI: 10.1080/14737175.2019.1581608] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 02/08/2019] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Iron (Fe) and manganese (Mn) are essential nutrients for humans. They act as cofactors for a variety of enzymes. In the central nervous system (CNS), these two metals are involved in diverse neurological activities. Dyshomeostasis may interfere with the critical enzymatic activities, hence altering the neurophysiological status and resulting in neurological diseases. Areas covered: In this review, the authors cover the molecular mechanisms of Fe/Mn-induced toxicity and neurological diseases, as well as the diagnosis and potential treatment. Given that both Fe and Mn are abundant in the earth crust, nutritional deficiency is rare. In this review the authors focus on the neurological disorders associated with Mn and Fe overload. Expert commentary: Oxidative stress and mitochondrial dysfunction are the primary molecular mechanism that mediates Fe/Mn-induced neurotoxicity. Although increased Fe or Mn concentrations have been found in brain of patients, it remains controversial whether the elevated metal amounts are the primary cause or secondary consequence of neurological diseases. Currently, treatments are far from satisfactory, although chelation therapy can significantly decrease brain Fe and Mn levels. Studies to determine the primary cause and establish the molecular mechanism of toxicity may help to adapt more comprehensive and satisfactory treatments in the future.
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Affiliation(s)
- Pan Chen
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Melissa Totten
- Department of Nutrition, University of North Carolina Greensboro, Greensboro, NC, USA
| | - Ziyan Zhang
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Hana Bucinca
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Keith Erikson
- Department of Nutrition, University of North Carolina Greensboro, Greensboro, NC, USA
| | - Abel Santamaría
- Laboratory of Excitatory Amino Acids, National Institute of Neurology and Neurosurgery, Mexico, Mexico City, Mexico
| | - Aaron B. Bowma
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
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Bowler RM, Yeh CL, Adams SW, Ward EJ, Ma RE, Dharmadhikari S, Snyder SA, Zauber SE, Wright CW, Dydak U. Association of MRI T1 relaxation time with neuropsychological test performance in manganese- exposed welders. Neurotoxicology 2018; 64:19-29. [PMID: 28587807 PMCID: PMC5905426 DOI: 10.1016/j.neuro.2017.05.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 05/23/2017] [Accepted: 05/30/2017] [Indexed: 01/07/2023]
Abstract
This study examines the results of neuropsychological testing of 26 active welders and 17 similar controls and their relationship to welders' shortened MRI T1 relaxation time, indicative of increased brain manganese (Mn) accumulation. Welders were exposed to Mn for an average duration of 12.25 years to average levels of Mn in air of 0.11±0.05mg/m3. Welders scored significantly worse than controls on Fruit Naming and the Parallel Lines test of graphomotor tremor. Welders had shorter MRI T1 relaxation times than controls in the globus pallidus, substantia nigra, caudate nucleus, and the anterior prefrontal lobe. 63% of the variation in MRI T1 relaxation times was accounted for by exposure group. In welders, lower relaxation times in the caudate nucleus and substantia nigra were associated with lower neuropsychological test performance on tests of verbal fluency (Fruit Naming), verbal learning, memory, and perseveration (WHO-UCLA AVLT). Results indicate that verbal function may be one of the first cognitive domains affected by brain Mn deposition in welders as reflected by MRI T1 relaxation times.
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Affiliation(s)
- R M Bowler
- San Francisco State University, Department of Psychology, 1600 Holloway Ave., San Francisco, CA 94132, USA.
| | - C-L Yeh
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 950 W. Walnut Street, Indianapolis, IN, 46202, USA
| | - S W Adams
- San Francisco State University, Department of Psychology, 1600 Holloway Ave., San Francisco, CA 94132, USA
| | - E J Ward
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, USA
| | - R E Ma
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 950 W. Walnut Street, Indianapolis, IN, 46202, USA
| | - S Dharmadhikari
- Department of Radiology and Imaging Sciences, Emory University Hospital,1364 Clifton Road, Atlanta, GA, 30322, USA
| | - S A Snyder
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, USA; Department of Speech, Language and Hearing Sciences, Purdue University, 715 Clinic Drive, West Lafayette, IN 47907, USA
| | - S E Zauber
- Department of Neurology, Indiana University School of Medicine, 355 W 16th St, Indianapolis, IN 46202, USA
| | - C W Wright
- San Francisco State University, Department of Psychology, 1600 Holloway Ave., San Francisco, CA 94132, USA
| | - U Dydak
- School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 950 W. Walnut Street, Indianapolis, IN, 46202, USA; Department of Speech, Language and Hearing Sciences, Purdue University, 715 Clinic Drive, West Lafayette, IN 47907, USA.
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10
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Bailey LA, Kerper LE, Goodman JE. Derivation of an occupational exposure level for manganese in welding fumes. Neurotoxicology 2018. [DOI: 10.1016/j.neuro.2017.06.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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11
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Lachowicz JI, Nurchi VM, Crisponi G, Cappai I, Cappai R, Busato M, Melchior A, Tolazzi M, Peana M, Garribba E, Zoroddu MA, Coni P, Pichiri G, Aaseth J. para-Aminosalicylic acid in the treatment of manganese toxicity. Complexation of Mn2+ with 4-amino-2-hydroxybenzoic acid and its N-acetylated metabolite. NEW J CHEM 2018. [DOI: 10.1039/c7nj04648k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Manganese excess can induce in humans neurological disorders known as manganism.
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12
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Casjens S, Dydak U, Dharmadhikari S, Lotz A, Lehnert M, Quetscher C, Stewig C, Glaubitz B, Schmidt-Wilcke T, Edmondson D, Yeh CL, Weiss T, Thriel CV, Herrmann L, Muhlack S, Woitalla D, Aschner M, Brüning T, Pesch B. Association of exposure to manganese and iron with striatal and thalamic GABA and other neurometabolites - Neuroimaging results from the WELDOX II study. Neurotoxicology 2018; 64:60-67. [PMID: 28803850 PMCID: PMC5808902 DOI: 10.1016/j.neuro.2017.08.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 07/24/2017] [Accepted: 08/07/2017] [Indexed: 11/17/2022]
Abstract
OBJECTIVE Magnetic resonance spectroscopy (MRS) is a non-invasive method to quantify neurometabolite concentrations in the brain. Within the framework of the WELDOX II study, we investigated the association of exposure to manganese (Mn) and iron (Fe) with γ-aminobutyric acid (GABA) and other neurometabolites in the striatum and thalamus of 154 men. MATERIAL AND METHODS GABA-edited and short echo-time MRS at 3T was used to assess brain levels of GABA, glutamate, total creatine (tCr) and other neurometabolites. Volumes of interest (VOIs) were placed into the striatum and thalamus of both hemispheres of 47 active welders, 20 former welders, 36 men with Parkinson's disease (PD), 12 men with hemochromatosis (HC), and 39 male controls. Linear mixed models were used to estimate the influence of Mn and Fe exposure on neurometabolites while simultaneously adjusting for cerebrospinal fluid (CSF) content, age and other factors. Exposure to Mn and Fe was assessed by study group, blood concentrations, relaxation rates R1 and R2* in the globus pallidus (GP), and airborne exposure (active welders only). RESULTS The median shift exposure to respirable Mn and Fe in active welders was 23μg/m3 and 110μg/m3, respectively. Airborne exposure was not associated with any other neurometabolite concentration. Mn in blood and serum ferritin were highest in active and former welders. GABA concentrations were not associated with any measure of exposure to Mn or Fe. In comparison to controls, tCr in these VOIs was lower in welders and patients with PD or HC. Serum concentrations of ferritin and Fe were associated with N-acetylaspartate, but in opposed directions. Higher R1 values in the GP correlated with lower neurometabolite concentrations, in particular tCr (exp(β)=0.87, p<0.01) and choline (exp(β)=0.84, p=0.04). R2* was positively associated with glutamate-glutamine and negatively with myo-inositol. CONCLUSIONS Our results do not provide evidence that striatal and thalamic GABA differ between Mn-exposed workers, PD or HC patients, and controls. This may be due to the low exposure levels of the Mn-exposed workers and the challenges to detect small changes in GABA. Whereas Mn in blood was not associated with any neurometabolite content in these VOIs, a higher metal accumulation in the GP assessed with R1 correlated with generally lower neurometabolite concentrations.
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Affiliation(s)
- Swaantje Casjens
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Bochum, Germany.
| | - Urike Dydak
- School of Health Sciences, Purdue University, West Lafayette, IN, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Shalmali Dharmadhikari
- School of Health Sciences, Purdue University, West Lafayette, IN, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Anne Lotz
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Bochum, Germany
| | - Martin Lehnert
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Bochum, Germany
| | - Clara Quetscher
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Bochum, Germany
| | - Christoph Stewig
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Bochum, Germany
| | - Benjamin Glaubitz
- Department of Neurology, BG University Hospital Bergmannsheil, Ruhr-Universität Bochum, Bochum, Germany
| | - Tobias Schmidt-Wilcke
- Department of Neurology, BG University Hospital Bergmannsheil, Ruhr-Universität Bochum, Bochum, Germany; Institute of Clinical Neuroscience and Medical Psychology, University of Düsseldorf, Düsseldorf, Germany
| | - David Edmondson
- School of Health Sciences, Purdue University, West Lafayette, IN, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Chien-Lin Yeh
- School of Health Sciences, Purdue University, West Lafayette, IN, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Tobias Weiss
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Bochum, Germany
| | - Christoph van Thriel
- Leibniz Research Centre for Working Environment and Human Factors (IfADo), Dortmund, Germany
| | | | | | - Dirk Woitalla
- Department of Neurology, Sankt Josef Hospital, Bochum, Germany
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, New York, NY, USA
| | - Thomas Brüning
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Bochum, Germany
| | - Beate Pesch
- Institute for Prevention and Occupational Medicine of the German Social Accident Insurance, Institute of the Ruhr-Universität Bochum (IPA), Bochum, Germany
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Sanchez-Ramos J, Song S, Kong X, Foroutan P, Martinez G, Dominguez-Viqueria W, Mohapatra S, Mohapatra S, Haraszti RA, Khvorova A, Aronin N, Sava V. Chitosan-Mangafodipir nanoparticles designed for intranasal delivery of siRNA and DNA to brain. J Drug Deliv Sci Technol 2017; 43:453-460. [PMID: 29805475 DOI: 10.1016/j.jddst.2017.11.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The overall objective of the present research was to develop a nanocarrier system for non-invasive delivery to brain of molecules useful for gene therapy. Manganese-containing nanoparticles (mNPs) carrying anti-eGFP siRNA were tested in cell cultures of eGFP-expressing cell line of mouse fibroblasts (NIH3T3). The optimal mNPs were then tested in vivo in mice. Following intranasal instillation, mNPs were visualized by 7T MRI throughout brain at 24 and 48 hrs. mNPs were effective in significantly reducing GFP mRNA expression in Tg GFP+ mice in olfactory bulb, striatum, hippocampus and cortex. Intranasal instillation of mNPS loaded with dsDNA encoding RFP also resulted in expression of the RFP in multiple brain regions. In conclusion, mNPs carrying siRNA, or dsDNA were capable of delivering the payload from nose to brain. This approach for delivery of gene therapies to humans, if successful, will have a significant impact on disease-modifying therapeutics of neurodegenerative diseases.
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Affiliation(s)
| | - Shijie Song
- Department of Neurology, University of South Florida, Tampa, FL, USA
| | - Xiaoyuan Kong
- Department of Neurology, University of South Florida, Tampa, FL, USA
| | | | - Gary Martinez
- Mofftt Cancer Center and Research Institute, Tampa, FL, USA
| | | | | | | | - Reka A Haraszti
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - Anastasia Khvorova
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA, USA
| | - Neil Aronin
- Department of Medicine, University of Massachusetts Medical School, Worcester, MA, USA
| | - Vasyl Sava
- Department of Neurology, University of South Florida, Tampa, FL, USA
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Baek NJ, Park GI, Byun YS, Jeon MJ, Sakong J. Effects of computer familiarity and computer type on the performance of Korean computerized neurobehavioral test. Ann Occup Environ Med 2016; 28:44. [PMID: 27617101 PMCID: PMC5016868 DOI: 10.1186/s40557-016-0129-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 09/02/2016] [Indexed: 11/20/2022] Open
Abstract
Background It is thought that computer familiarity has increased significantly since 2004 as well as the use of computers. This study aimed to evaluate the effects of computer familiarity and types of keyboard and computer on the performance of the Korean computerized neurobehavioral test (KCNT), and to identify which parameters of KCNT were affected by aforementioned factors. Methods A total of 85 subjects were classified into three groups of computer familiarity by Korean typing speed. Their age, gender and the level of education were also collected. The parameters of KCNT included simple reaction time, choice reaction time, addition, symbol digit, and finger tapping speed. The test was conducted using three types of computers: a laptop computer, a laptop computer with a simplified keyboard, and a desktop computer with a simplified keyboard. Results Parameters including the simple reaction time, choice reaction time, addition, and symbol digit, and the finger tapping speed of non-dominant hand showed no significant differences in the results among the three groups by computer familiarity after age and educational years were controlled as covariates. The mean reaction time of the simple reaction time and the choice reaction time with a simplified keyboard was significantly shorter compared to that with a typical keyboard. With regard to type of computer, the mean reaction time of the simple reaction time and the choice reaction time was significantly reduced when performed with the desktop computer with a simplified keyboard. Conclusions Unlike previous study results, the choice reaction time, the addition, and the finger tapping speed of dominant hand were the only parameters affected by the computer familiarity. Both the type of keyboard and the type of computer significantly influenced the simple reaction time and the choice reaction time. Therefore, it is recommended to use a desktop computer with a simplified keyboard for such parameters.
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Affiliation(s)
- Nak Joon Baek
- Department of Occupational and Environmental Medicine, Yeungnam University Hospital, 170 Hyeonchung-ro, Nam-gu, Daegu, 42415 Republic of Korea
| | - Gun Il Park
- Department of Occupational and Environmental Medicine, Yeungnam University Hospital, 170 Hyeonchung-ro, Nam-gu, Daegu, 42415 Republic of Korea
| | - Young Seok Byun
- Department of Occupational and Environmental Medicine, Yeungnam University Hospital, 170 Hyeonchung-ro, Nam-gu, Daegu, 42415 Republic of Korea
| | - Man Joong Jeon
- Department of Occupational and Environmental Medicine, Yeungnam University Hospital, 170 Hyeonchung-ro, Nam-gu, Daegu, 42415 Republic of Korea ; Department of Preventive Medicine and Public Health, College of Medicine, Yeungnam University, 170 Hyeonchung-ro, Nam-gu, Daegu, 42415 Republic of Korea
| | - Joon Sakong
- Department of Occupational and Environmental Medicine, Yeungnam University Hospital, 170 Hyeonchung-ro, Nam-gu, Daegu, 42415 Republic of Korea ; Department of Preventive Medicine and Public Health, College of Medicine, Yeungnam University, 170 Hyeonchung-ro, Nam-gu, Daegu, 42415 Republic of Korea
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15
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Ross JA, Shipp EM, Trueblood AB, Bhattacharya A. Ergonomics and Beyond: Understanding How Chemical and Heat Exposures and Physical Exertions at Work Affect Functional Ability, Injury, and Long-Term Health. HUMAN FACTORS 2016; 58:777-795. [PMID: 27125533 PMCID: PMC6894162 DOI: 10.1177/0018720816645457] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 03/12/2016] [Indexed: 06/05/2023]
Abstract
OBJECTIVE To honor Tom Waters's work on emerging occupational health issues, we review the literature on physical along with chemical exposures and their impact on functional outcomes. BACKGROUND Many occupations present the opportunity for exposure to multiple hazardous exposures, including both physical and chemical factors. However, little is known about how these different factors affect functional ability and injury. The goal of this review is to examine the relationships between these exposures, impairment of the neuromuscular and musculoskeletal systems, functional outcomes, and health problems with a focus on acute injury. METHOD Literature was identified using online databases, including PubMed, Ovid Medline, and Google Scholar. References from included articles were searched for additional relevant articles. RESULTS This review documented the limited existing literature that discussed cognitive impairment and functional disorders via neurotoxicity for physical exposures (heat and repetitive loading) and chemical exposures (pesticides, volatile organic compounds [VOCs], and heavy metals). CONCLUSION This review supports that workers are exposed to physical and chemical exposures that are associated with negative health effects, including functional impairment and injury. Innovation in exposure assessment with respect to quantifying the joint exposure to these different exposures is especially needed for developing risk assessment models and, ultimately, preventive measures. APPLICATION Along with physical exposures, chemical exposures need to be considered, alone and in combination, in assessing functional ability and occupationally related injuries.
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Affiliation(s)
- Jennifer A Ross
- Texas A&M University, College StationUniversity of Cincinnati, Ohio
| | - Eva M Shipp
- Texas A&M University, College StationUniversity of Cincinnati, Ohio
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Bowler RM, Kornblith ES, Gocheva VV, Colledge MA, Bollweg G, Kim Y, Beseler CL, Wright CW, Adams SW, Lobdell DT. Environmental exposure to manganese in air: Associations with cognitive functions. Neurotoxicology 2015; 49:139-48. [PMID: 26096496 DOI: 10.1016/j.neuro.2015.06.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 06/12/2015] [Accepted: 06/12/2015] [Indexed: 12/17/2022]
Abstract
Manganese (Mn), an essential element, can be neurotoxic in high doses. This cross-sectional study explored the cognitive function of adults residing in two towns (Marietta and East Liverpool, Ohio, USA) identified as having high levels of environmental airborne Mn from industrial sources. Air-Mn site surface emissions method modeling for total suspended particulate (TSP) ranged from 0.03 to 1.61 μg/m(3) in Marietta and 0.01-6.32 μg/m(3) in East Liverpool. A comprehensive screening test battery of cognitive function, including the domains of abstract thinking, attention/concentration, executive function and memory was administered. The mean age of the participants was 56 years (±10.8 years). Participants were mostly female (59.1) and primarily white (94.6%). Significant relationships (p<0.05) were found between Mn exposure and performance on working and visuospatial memory (e.g., Rey-O Immediate β=-0.19, Rey-O Delayed β=-0.16) and verbal skills (e.g., Similarities β=-0.19). Using extensive cognitive testing and computer modeling of 10-plus years of measured air monitoring data, this study suggests that long-term environmental exposure to high levels of air-Mn, the exposure metric of this paper, may result in mild deficits of cognitive function in adult populations.
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Affiliation(s)
- Rosemarie M Bowler
- San Francisco State University, Department of Psychology, 1600 Holloway Ave., San Francisco, CA 94132, USA.
| | - Erica S Kornblith
- California School of Professional Psychology at Alliant International University, 1 Beach St., Suite 100, San Francisco, CA 94133, USA
| | - Vihra V Gocheva
- San Francisco State University, Department of Psychology, 1600 Holloway Ave., San Francisco, CA 94132, USA
| | - Michelle A Colledge
- Agency for Toxic Substances and Disease Registry, Region 5, 77W. Jackson Blvd., MS ATSD-4J, Chicago, IL 60604, USA
| | - George Bollweg
- U.S. EPA Region 5, 77W. Jackson Blvd., AR 18-J, Chicago, IL 60604, USA
| | - Yangho Kim
- Ulsan University Hospital, University of Ulsan College of Medicine, Department of Occupational and Environmental Medicine, Ulsan 682-060, South Korea
| | - Cheryl L Beseler
- Colorado State University, 1879 Campus Delivery, Fort Collins, CO 80523, USA
| | - Chris W Wright
- San Francisco State University, Department of Psychology, 1600 Holloway Ave., San Francisco, CA 94132, USA
| | - Shane W Adams
- San Francisco State University, Department of Psychology, 1600 Holloway Ave., San Francisco, CA 94132, USA
| | - Danelle T Lobdell
- U.S. EPA, National Health and Environmental Effects Research Laboratory, MD 58A, Research Triangle Park, NC 27711, USA
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17
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Hoet P, Roels HA. Significance and Usefulness of Biomarkers of Exposure to Manganese. MANGANESE IN HEALTH AND DISEASE 2014. [DOI: 10.1039/9781782622383-00355] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Manganese (Mn) accomplishes functions essential to maintaining human health, but at the same time this trace element can be toxic at low levels of exposure and accurate estimation of internal exposure is needed. A biomarker of exposure to Mn is meaningful only if there is sufficient knowledge of the toxicokinetics determining its presence in a biological medium (e.g. whole blood, plasma, urine, hair, nail). Moreover, biological monitoring of exposure to Mn is useful only when the biomarker is sufficiently specific and sensitive to distinguish exposed from non-exposed subjects, when it is dose-related to the external exposure (current, recent, or time-integrated), and when it displays reasonable dose–effect/response relationships with the occurrence of adverse effects on the central nervous system, the critical target for Mn exposure. Human investigations in which biomarkers of Mn exposure meet all these criteria are hard to locate. Overall, the available studies report poor or no associations on an individual basis between external (Mn in air or drinking water) and internal (Mn in blood, urine, hair, or nail) Mn exposure indices. This may be to some extent explained by features inherent of the Mn metabolism (homeostatic control), the Mn biomarker's half-life with respect to the exposure window, and the variable nature of external exposure scenarios. Studies particularly dealing with Mn inhalation exposure, different or poorly described methodological approaches, or air sampling strategies may render direct comparison and interpretation of results a tedious task. Nevertheless, several studies report significant dose–effect associations between biomarkers of Mn exposure and subclinical deficits of psychomotor or neuropsychological test performances. Because directly associated with the site of toxic action and providing the magnetic resonance imaging is done no later than three months after Mn exposure ceased, the Mn T1 relaxation time is potentially the better biomarker of Mn exposure in a clinical context (e.g. after long-term parenteral nutrition, chronic liver failure, methcathinone drug abuse). Magnetic resonance imaging is, however, unpractical as a tool for biological monitoring of exposure to Mn in the occupational setting (inhalation) and in the general population (air, drinking water). In conclusion, it would be inappropriate to recommend, on the basis of the currently available evidence, a reliable well-validated biomarker of exposure to Mn, or to establish a health-based threshold value for subclinical neurotoxic effects.
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Affiliation(s)
- Perrine Hoet
- Université catholique de Louvain (UCL), Institut de Recherche Expérimentale et Clinique (IREC), Louvain Centre for Toxicology and Applied Pharmacology (LTAP) Bruxelles Belgium
| | - Harry A. Roels
- Université catholique de Louvain (UCL), Institut de Recherche Expérimentale et Clinique (IREC), Louvain Centre for Toxicology and Applied Pharmacology (LTAP) Bruxelles Belgium
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18
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Mousa AM, Shehab AA. The effect of manganese on the olfactory bulb of adult male albino rat and the role of meloxicam: A histological and immunohistochemical study. J Microsc Ultrastruct 2014; 3:8-18. [PMID: 30023176 PMCID: PMC6014222 DOI: 10.1016/j.jmau.2014.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 11/06/2014] [Accepted: 11/11/2014] [Indexed: 12/27/2022] Open
Abstract
Manganese (Mn) is an essential metal commonly found in the environment and is used for industrial purposes. Exposure to excessively high Mn levels may induce neurotoxicity referred to as manganism. This work was conducted to study the effect of manganese on the olfactory bulb of adult male albino rat and the possible protective role of meloxicam. Forty adult male albino rats were equally divided into four groups: control group, meloxicam-treated group (5 mg/kg/day orally for 4 weeks), MnCl2-treated group (10 mg/kg/day orally for 4 weeks), and the fourth group received both meloxicam and MnCl2 at the same doses and duration. Specimens of the olfactory bulbs were prepared for light and electron microscopy. An immunohistochemical study with a quantitative morphometry was performed using antibodies against glial fibrillary acidic protein (GFAP). The control group and meloxicam-treated group showed the same normal structure. MnCl2-treated group showed shrinkage of mitral nerve cells with dark peripheral nuclei as well as disorganization of mitral and granule nerve cells. The surrounding neuropil showed vacuolar spaces. Ultrastructurally, the mitral cells showed accumulation of lysosomes, swelling of mitochondria and irregularity of the nuclei. The nerve fibers contained swollen mitochondria with splitting and irregularity of the surrounding myelin sheaths. GFAP immunoreaction showed a highly significant increase compared to control group. On the other hand, the group that received both meloxicam and MnCl2 showed less marked histological changes. It was concluded that manganese induced structural changes in the olfactory bulb of albino rat that were ameliorated by concomitant use of meloxicam.
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Affiliation(s)
- Amany M Mousa
- Histology Department, Faculty of Medicine, Tanta University, Egypt
| | - Amal A Shehab
- Anatomy & Embryology Department, Faculty of Medicine, Tanta University, Egypt
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19
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Lv Y, Zou Y, Liu J, Chen K, Huang D, Shen Y, Zhong Y, Liu Z, Jiang B, Li Q, Qing L, Zhang W, Chen L, Wang F, Xia B, Yang L, Yang X. Rationale, design and baseline results of the Guangxi manganese-exposed workers healthy cohort (GXMEWHC) study. BMJ Open 2014; 4:e005070. [PMID: 24993760 PMCID: PMC4091505 DOI: 10.1136/bmjopen-2014-005070] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
OBJECTIVE To determine the relationship between biomarkers of exposure, disease and susceptibility, and early health effects and long-term diseases related to occupational manganese (Mn) exposure. DESIGN Baseline survey of a longitudinal cohort study of workers in a ferromanganese refinery. PARTICIPANTS A total of 1888 individuals (1197 men, 691 women; average seniority 15.34 years) were enrolled in the Guangxi manganese-exposed workers healthy cohort (GXMEWHC) study. Participants were between 18 and 60 years of age (mean 40.31 years), had worked in the ferromanganese refinery for at least 1 year and lived in the local area. RESULTS The GXMEWHC study included a baseline survey. Participants were divided into four groups according to manganese (Mn) cumulative exposure index (Mn-CEI) levels: an internal control group (Mn-CEI <1.0 mg/m(3) year), a low exposure group (1.0 mg/m(3) year≤Mn-CEI<2.0 mg/m(3) year), a medium exposure group (2.0 mg/m(3) year≤Mn-CEI<5.0 mg/m(3) year) and a high exposure group (Mn-CEI≥5.0 mg/m(3) year). Genome-wide association studies of quantitative trait loci and binary trait loci in 500 Mn-exposed workers were performed using Illumina Infinium HumanExome BeadChip arrays. Stored plasma, DNA, hair and urine are available for further study. Participants will be followed up every 3 years. CONCLUSIONS The GXMEWHC study provides abundant data for exploring the systemic health effects of occupational Mn exposure using biomarkers of exposure, disease and susceptibility.
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Affiliation(s)
- Yingnan Lv
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Yunfeng Zou
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Jing Liu
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Kangcheng Chen
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Damin Huang
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Yuefei Shen
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Yaoqiu Zhong
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Zhihao Liu
- Baise Center for Disease Control and Prevention, Baise, Guangxi, China
| | - Bei Jiang
- Baise Center for Disease Control and Prevention, Baise, Guangxi, China
| | - Qin Li
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Li Qing
- Department of Epidemiology and Health Statistics, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Wei Zhang
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Lang Chen
- Department of Neurology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Fenfen Wang
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Bing Xia
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Li Yang
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Xiaobo Yang
- Department of Occupational Health and Environmental Health, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China
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20
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Li SJ, Jiang L, Fu X, Huang S, Huang YN, Li XR, Chen JW, Li Y, Luo HL, Wang F, Ou SY, Jiang YM. Pallidal index as biomarker of manganese brain accumulation and associated with manganese levels in blood: a meta-analysis. PLoS One 2014; 9:e93900. [PMID: 24718592 PMCID: PMC3981755 DOI: 10.1371/journal.pone.0093900] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 03/09/2014] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE The current study was designed to evaluate the sensitivity, feasibility, and effectiveness of the pallidal index (PI) serving as a biomarker of brain manganese (Mn) accumulation, which would be used as an early diagnosis criteria for Mn neurotoxicity. METHODS The weighted mean difference (WMD) of the PI between control and Mn-exposed groups was estimated by using a random-effects or fixed-effects meta-analysis with 95% confidence interval (CI) performed by STATA software version 12.1. Moreover, the R package "metacor" was used to estimate correlation coefficients between PI and blood Mn (MnB). RESULTS A total of eight studies with 281 occupationally Mn-exposed workers met the inclusion criteria. Results were pooled and performed with the Meta-analysis. Our data indicated that the PI of the exposed group was significantly higher than that of the control (WMD: 7.76; 95% CI: 4.86, 10.65; I2 = 85.7%, p<0.0001). A random effects model was used to perform meta-analysis. These findings were remarkably robust in the sensitivity analysis, and publication bias was shown in the included studies. Seven out of the eight studies reported the Pearson correlation (r) values. Significantly positive correlation between PI and MnB was observed (r = 0.42; 95% CI, 0.31, 0.52). CONCLUSIONS PI can be considered as a sensitive, feasible, effective and semi-quantitative index in evaluating brain Mn accumulation. MnB can also augment the evaluation of brain Mn accumulation levels in the near future. However, the results should be interpreted with caution.
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Affiliation(s)
- Shao-Jun Li
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Li Jiang
- Department of Radiotherapy, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Xue Fu
- School of Health Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Shuang Huang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Yan-Ni Huang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Xiang-Rong Li
- Department of Radiology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Jing-Wen Chen
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Yong Li
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Hai-Lan Luo
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Fang Wang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Shi-Yan Ou
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
| | - Yue-Ming Jiang
- Department of Toxicology, School of Public Health, Guangxi Medical University, Nanning, Guangxi, China
- * E-mail:
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21
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Long Z, Jiang YM, Li XR, Fadel W, Xu J, Yeh CL, Long LL, Luo HL, Harezlak J, Murdoch JB, Zheng W, Dydak U. Vulnerability of welders to manganese exposure--a neuroimaging study. Neurotoxicology 2014; 45:285-92. [PMID: 24680838 DOI: 10.1016/j.neuro.2014.03.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 03/01/2014] [Accepted: 03/19/2014] [Indexed: 01/19/2023]
Abstract
Increased manganese (Mn) exposure is known to cause cognitive, psychiatric and motor deficits. Mn exposure occurs in different occupational settings, where the airborne Mn level and the size of respirable particulates may vary considerably. Recently the importance of the role of the cerebral cortex in Mn toxicity has been highlighted, especially in Mn-induced neuropsychological effects. In this study we used magnetic resonance imaging (MRI) to evaluate brain Mn accumulation using T1 signal intensity indices and to examine changes in brain iron content using T2* contrast, as well as magnetic resonance spectroscopy (MRS) to measure exposure-induced metabolite changes non-invasively in cortical and deep brain regions in Mn-exposed welders, Mn-exposed smelter workers and control factory workers with no measurable exposure to Mn. MRS data as well as T1 signal intensity indices and T2* values were acquired from the frontal cortex, posterior cingulate cortex, hippocampus, and thalamus. Smelters were exposed to higher air Mn levels and had a longer duration of exposure, which was reflected in higher Mn levels in erythrocytes and urine than in welders. Nonetheless, welders had more significant metabolic differences compared to controls than did the smelter workers, especially in the frontal cortex. T1 hyperintensities in the globus pallidus were observed in both Mn-exposed groups, but only welders showed significantly higher thalamic and hippocampal T1 hyperintensities, as well as significantly reduced T2* values in the frontal cortex. Our results indicate that (1) the cerebral cortex, in particular the frontal cortex, is clearly involved in Mn neurotoxic effects and (2) in spite of the lower air Mn levels and shorter duration of exposure, welders exhibit more extensive neuroimaging changes compared to controls than smelters, including measurable deposition of Mn in more brain areas. These results indicate that the type of exposure (particulate sizes, dust versus fume) and route of exposure play an important role in the extent of Mn-induced toxic effects on the brain.
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Affiliation(s)
- Zaiyang Long
- School of Health Sciences, Purdue University, West Lafayette, IN, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Yue-Ming Jiang
- Department of Health Toxicology, Guangxi Medical University, Nanning, China.
| | - Xiang-Rong Li
- Department of Radiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - William Fadel
- Department of Biostatistics, Richard M. Fairbanks School of Public Health, Indiana University, Indianapolis, IN, USA
| | - Jun Xu
- School of Health Sciences, Purdue University, West Lafayette, IN, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Chien-Lin Yeh
- School of Health Sciences, Purdue University, West Lafayette, IN, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Li-Ling Long
- Department of Radiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Hai-Lan Luo
- Department of Health Toxicology, Guangxi Medical University, Nanning, China
| | - Jaroslaw Harezlak
- Department of Biostatistics, Richard M. Fairbanks School of Public Health, Indiana University, Indianapolis, IN, USA; Department of Biostatistics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - James B Murdoch
- Toshiba Medical Research Institute USA, Mayfield Village, OH, USA
| | - Wei Zheng
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
| | - Ulrike Dydak
- School of Health Sciences, Purdue University, West Lafayette, IN, USA; Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA.
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22
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Rugless F, Bhattacharya A, Succop P, Dietrich KN, Cox C, Alden J, Kuhnell P, Barnas M, Wright R, Parsons PJ, Praamsma ML, Palmer CD, Beidler C, Wittberg R, Haynes EN. Childhood exposure to manganese and postural instability in children living near a ferromanganese refinery in Southeastern Ohio. Neurotoxicol Teratol 2014; 41:71-9. [PMID: 24370548 PMCID: PMC3943914 DOI: 10.1016/j.ntt.2013.12.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 12/05/2013] [Accepted: 12/16/2013] [Indexed: 12/19/2022]
Abstract
Airborne manganese (Mn) exposure can result in neurotoxicity and postural instability in occupationally exposed workers, yet few studies have explored the association ambient exposure to Mn in children and postural stability. The goal of this study was to determine the association between Mn and lead (Pb) exposure, as measured by blood Pb, blood and hair Mn and time weighted distance (TWD) from a ferromanganese refinery, and postural stability in children. A subset of children ages 7-9 years enrolled in the Marietta Community Actively Researching Exposure Study (CARES) were invited to participate. Postural balance was conducted on 55 children residing in Marietta, Ohio and the surrounding area. Samples of blood were collected and analyzed for Mn and Pb, and samples of hair were analyzed for Mn. Neuromotor performance was assessed using postural balance testing with a computer force platform system. Pearson correlations were calculated to identify key covariates. Associations between postural balance testing conditions and Mn and Pb exposure were estimated with linear regression analyses adjusting for gender, age, parent IQ, and parent age. Mean blood Mn was 10 μg/L (SEM=0.36), mean blood Pb was 0.85 μg/dL (SEM=0.05), and mean hair Mn was 0.76 μg/g (SEM=0.16). Mean residential distance from the refinery was 11.5 km (SEM=0.46). All three measures of Mn exposure were significantly associated with poor postural balance. In addition, low-level blood Pb was also negatively associated with balance outcomes. We conclude that Mn exposure and low-level blood Pb are significantly associated with poor postural balance.
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Affiliation(s)
- Fedoria Rugless
- University of Cincinnati College of Medicine, Department of Environmental Health, Division of Epidemiology and Biostatistics, 3223 Eden Ave., PO Box 670056, Cincinnati, OH 45267-0056, United States.
| | - Amit Bhattacharya
- University of Cincinnati College of Medicine, Department of Environmental Health, Division of Epidemiology and Biostatistics, 3223 Eden Ave., PO Box 670056, Cincinnati, OH 45267-0056, United States.
| | - Paul Succop
- University of Cincinnati College of Medicine, Department of Environmental Health, Division of Epidemiology and Biostatistics, 3223 Eden Ave., PO Box 670056, Cincinnati, OH 45267-0056, United States.
| | - Kim N Dietrich
- University of Cincinnati College of Medicine, Department of Environmental Health, Division of Epidemiology and Biostatistics, 3223 Eden Ave., PO Box 670056, Cincinnati, OH 45267-0056, United States.
| | - Cyndy Cox
- University of Cincinnati College of Medicine, Department of Environmental Health, Division of Epidemiology and Biostatistics, 3223 Eden Ave., PO Box 670056, Cincinnati, OH 45267-0056, United States.
| | - Jody Alden
- University of Cincinnati College of Medicine, Department of Environmental Health, Division of Epidemiology and Biostatistics, 3223 Eden Ave., PO Box 670056, Cincinnati, OH 45267-0056, United States.
| | - Pierce Kuhnell
- University of Cincinnati College of Medicine, Department of Environmental Health, Division of Epidemiology and Biostatistics, 3223 Eden Ave., PO Box 670056, Cincinnati, OH 45267-0056, United States.
| | - Mary Barnas
- Marietta College, 215 5th Street, Marietta, OH 45740, United States.
| | - Robert Wright
- Harvard University, Channing Laboratory, 181 Longwood Ave., Boston, MA 02115, United States.
| | - Patrick J Parsons
- Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, PO Box 509, Albany, NY 12201-0509, United States; University at Albany, Department of Environmental Health Sciences, School of Public Health, Albany, NY, United States.
| | - Meredith L Praamsma
- Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, PO Box 509, Albany, NY 12201-0509, United States; University at Albany, Department of Environmental Health Sciences, School of Public Health, Albany, NY, United States.
| | - Christopher D Palmer
- Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, PO Box 509, Albany, NY 12201-0509, United States; University at Albany, Department of Environmental Health Sciences, School of Public Health, Albany, NY, United States.
| | | | - Richard Wittberg
- Mid-Ohio Valley Health Department, 211 6th St., Parkersburg, WV 26101, United States.
| | - Erin N Haynes
- University of Cincinnati College of Medicine, Department of Environmental Health, Division of Epidemiology and Biostatistics, 3223 Eden Ave., PO Box 670056, Cincinnati, OH 45267-0056, United States.
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23
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Ellingsen DG, Kusraeva Z, Bast-Pettersen R, Zibarev E, Chashchin M, Thomassen Y, Chashchin V. The interaction between manganese exposure and alcohol on neurobehavioral outcomes in welders. Neurotoxicol Teratol 2014; 41:8-15. [DOI: 10.1016/j.ntt.2013.11.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Revised: 10/31/2013] [Accepted: 11/12/2013] [Indexed: 12/18/2022]
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24
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Meyer-Baron M, Schäper M, Knapp G, Lucchini R, Zoni S, Bast-Pettersen R, Ellingsen DG, Thomassen Y, He S, Yuan H, Niu Q, Wang XL, Yang YJ, Iregren A, Sjögren B, Blond M, Laursen P, Netterstrom B, Mergler D, Bowler R, van Thriel C. The neurobehavioral impact of manganese: results and challenges obtained by a meta-analysis of individual participant data. Neurotoxicology 2013; 36:1-9. [PMID: 23419685 DOI: 10.1016/j.neuro.2013.02.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Revised: 02/06/2013] [Accepted: 02/06/2013] [Indexed: 01/30/2023]
Abstract
Results from a meta-analysis of aggregated data provoked a new analysis using individual data on the neuropsychological performance of occupationally exposed workers. Data from eight studies examining 579 exposed and 433 reference participants were included, 28 performance variables analyzed. The performance scores were adjusted for well-known individual-level covariates; the influence of possible, but unknown study-level covariates was attenuated by means of a z-normalization. Associations between performance and exposure were estimated by ANOVAs and ANCOVAs, the latter representing multi-level models. Four cognitive and motor performance variables each indicated significantly lower performances of exposed individuals when confounding was considered; slowed motor performances and deficits in attention and short-term memory were found. Performance on a single test was significantly related to the biomarker manganese in blood. The outcomes on susceptibility were weak. The slowing of responses was the most distinct feature of performances of exposed workers. It remains unclear, whether this result is related to the employed tests or provides important information about early stages of the neurotoxic impairment. More specific cognitive tests need to be employed to answer this question. The lack of dose-response relationships was related to features of the biomarker: it does not reflect the Mn in brain responsible for changes in performances.
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Affiliation(s)
- Monika Meyer-Baron
- IfADo, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany.
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25
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Abstract
This article schematically reviews the clinical features, diagnostic approaches to, and toxicological implications of toxic encephalopathy. The review will focus on the most significant occupational causes of toxic encephalopathy. Chronic toxic encephalopathy, cerebellar syndrome, parkinsonism, and vascular encephalopathy are commonly encountered clinical syndromes of toxic encephalopathy. Few neurotoxins cause patients to present with pathognomonic neurological syndromes. The symptoms and signs of toxic encephalopathy may be mimicked by many psychiatric, metabolic, inflammatory, neoplastic, and degenerative diseases of the nervous system. Thus, the importance of good history-taking that considers exposure and a comprehensive neurological examination cannot be overemphasized in the diagnosis of toxic encephalopathy. Neuropsychological testing and neuroimaging typically play ancillary roles. The recognition of toxic encephalopathy is important because the correct diagnosis of occupational disease can prevent others (e.g., workers at the same worksite) from further harm by reducing their exposure to the toxin, and also often provides some indication of prognosis. Physicians must therefore be aware of the typical signs and symptoms of toxic encephalopathy, and close collaborations between neurologists and occupational physicians are needed to determine whether neurological disorders are related to occupational neurotoxin exposure.
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26
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Manganese in plasma: A promising biomarker of exposure to Mn in welders. A pilot study. Toxicol Lett 2012; 213:69-74. [DOI: 10.1016/j.toxlet.2011.06.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 06/09/2011] [Accepted: 06/10/2011] [Indexed: 12/22/2022]
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27
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Protective effects of ebselen (Ebs) and para-aminosalicylic acid (PAS) against manganese (Mn)-induced neurotoxicity. Toxicol Appl Pharmacol 2012; 258:394-402. [DOI: 10.1016/j.taap.2011.12.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Revised: 11/28/2011] [Accepted: 12/01/2011] [Indexed: 11/23/2022]
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28
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Neuromotor function in ship welders after cessation of manganese exposure. Int Arch Occup Environ Health 2011; 85:703-13. [DOI: 10.1007/s00420-011-0716-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2011] [Accepted: 10/11/2011] [Indexed: 10/15/2022]
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29
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Kim Y, Bowler RM, Abdelouahab N, Harris M, Gocheva V, Roels HA. Motor function in adults of an Ohio community with environmental manganese exposure. Neurotoxicology 2011; 32:606-14. [PMID: 21840336 DOI: 10.1016/j.neuro.2011.07.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 07/27/2011] [Accepted: 07/28/2011] [Indexed: 11/25/2022]
Abstract
OBJECTIVES The objective of the present study was to evaluate motor function in order to assess the effects of long-term, low-level environmental manganese (Mn) exposure in residents of an Ohio community where a large ferro- and silico-Mn smelter has been active for more than 50 years. METHODS One hundred residents from the Mn-exposed Ohio community were evaluated using the Unified Parkinson's Disease Rating Scale (UPDRS), a postural sway test, and a comprehensive questionnaire exploring demographics and general health. The results were compared to those of 90 residents from a demographically similar comparison town in Ohio. Mn exposure was assessed using modeled airborne Mn and blood Mn (Mn-B). The UPDRS was employed to evaluate parkinsonian motor features. Postural sway was measured using a CATSYS 2000 (Danish Product Development). RESULTS No significant difference between the exposed and comparison groups was evident as to Mn-B, demographics or major health outcomes. The risk of abnormal UPDRS performance using "Motor and Bradykinesia" criteria was increased in the Mn-exposed group after adjustment for potential confounders such as the presence of other neurotoxic metals, factors affecting susceptibility to Mn, potential factors influencing motor performance, and other possible demographic confounders. No participant was diagnosed with clinical manganism by neurological examination. After adjustment for various potential confounders, the Mn-exposed group showed significantly higher postural sway scores under eyes-open conditions than the comparison group. CONCLUSIONS Subclinical findings on the UPDRS and postural sway in the Mn-exposed group may possibly reflect early subtle effects of chronic low-level Mn exposure. However, the cross-sectional study design, the small to medium effect sizes, and the little biological plausibility are limiting the possibility of a causal relationship between the environmental Mn-air exposure and the early subclinical neurotoxic effects observed.
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Affiliation(s)
- Yangho Kim
- Department of Occupational and Environmental Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Dong-Gu, Ulsan, South Korea.
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30
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Dydak U, Jiang YM, Long LL, Zhu H, Chen J, Li WM, Edden RAE, Hu S, Fu X, Long Z, Mo XA, Meier D, Harezlak J, Aschner M, Murdoch JB, Zheng W. In vivo measurement of brain GABA concentrations by magnetic resonance spectroscopy in smelters occupationally exposed to manganese. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:219-24. [PMID: 20876035 PMCID: PMC3040609 DOI: 10.1289/ehp.1002192] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2010] [Accepted: 09/28/2010] [Indexed: 05/20/2023]
Abstract
BACKGROUND Exposure to excessive levels of manganese (Mn) is known to induce psychiatric and motor disorders, including parkinsonian symptoms. Therefore, finding a reliable means for early detection of Mn neurotoxicity is desirable. OBJECTIVES Our goal was to determine whether in vivo brain levels of γ-aminobutyric acid (GABA), N-acetylaspartate (NAA), and other brain metabolites in male smelters were altered as a consequence of Mn exposure. METHODS We used T1-weighted magnetic resonance imaging (MRI) to visualize Mn deposition in the brain. Magnetic resonance spectroscopy (MRS) was used to quantify concentrations of NAA, glutamate, and other brain metabolites in globus pallidus, putamen, thalamus, and frontal cortex from a well-established cohort of 10 male Mn-exposed smelters and 10 male age-matched control subjects. We used the MEGA-PRESS MRS sequence to determine GABA levels in a region encompassing the thalamus and adjacent parts of the basal ganglia [GABA-VOI (volume of interest)]. RESULTS Seven of 10 exposed subjects showed clear T1-hyperintense signals in the globus pallidus indicating Mn accumulation. We found a significant increase (82%; p = 0.014) in the ratio of GABA to total creatine (GABA/tCr) in the GABA-VOI of Mn-exposed subjects, as well as a distinct decrease (9%; p = 0.04) of NAA/tCr in frontal cortex that strongly correlated with cumulative Mn exposure (R = -0.93; p < 0.001). CONCLUSIONS We demonstrated elevated GABA levels in the thalamus and adjacent basal ganglia and decreased NAA levels in the frontal cortex, indicating neuronal dysfunction in a brain area not primarily targeted by Mn. Therefore, the noninvasive in vivo MRS measurement of GABA and NAA may prove to be a powerful tool for detecting presymptomatic effects of Mn neurotoxicity.
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Affiliation(s)
- Ulrike Dydak
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907, USA.
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31
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Marreilha Dos Santos AP, Lopes Santos M, Batoréu MC, Aschner M. Prolactin is a peripheral marker of manganese neurotoxicity. Brain Res 2011; 1382:282-90. [PMID: 21262206 DOI: 10.1016/j.brainres.2011.01.047] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 01/12/2011] [Accepted: 01/14/2011] [Indexed: 12/21/2022]
Abstract
UNLABELLED Excessive exposure to Mn induces neurotoxicity, referred to as manganism. Exposure assessment relies on Mn blood and urine analyses, both of which show poor correlation to exposure. Accordingly, there is a critical need for better surrogate biomarkers of Mn exposure. The aim of this study was to examine the relationship between Mn exposure and early indicators of neurotoxicity, with particular emphasis on peripheral biomarkers. Male Wistar rats (180-200g) were injected intraperitoneally with 4 or 8 doses of Mn (10mg/kg). Mn exposure was evaluated by analysis of Mn levels in brain and blood along with biochemical end-points (see below). RESULTS Brain Mn levels were significantly increased both after 4 and 8 doses of Mn compared with controls (p<0.001). Blood levels failed to reflect a dose-dependent increase in brain Mn, with only the 8-dose-treated group showing significant differences (p<0.001). Brain glutathione (GSH) levels were significantly decreased in the 8-dose-treated animals (p<0.001). A significant and dose-dependent increase in prolactin levels was found for both treated groups (p<0.001) compared to controls. In addition, a decrease in motor activity was observed in the 8-dose-treated group compared to controls. CONCLUSIONS (1) The present study demonstrates that peripheral blood level is a poor indicator of Mn brain accumulation and exposure; (2) Mn reduces GSH brain levels, likely reflecting oxidative stress; (3) Mn increases blood prolactin levels, indicating changes in the integrity of the dopaminergic system. Taken together these results suggest that peripheral prolactin levels may serve as reliable predictive biomarkers of Mn neurotoxicity.
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32
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Abstract
The purpose of this article was to provide a literature review of occupational neurological disorders and related research in Korea, focusing on chemical hazards. We reviewed occupational neurological disorders investigated by the Occupational Safety and Health Research Institute of Korean Occupational Safety and Health Agency between 1992 and 2009, categorizing them as neurological disorders of the central nervous system (CNS), of the peripheral nervous system (PNS) or as neurodegenerative disorders. We also examined peer-reviewed journal articles related to neurotoxicology, published from 1984 to 2009. Outbreaks of occupational neurological disorder of the CNS due to inorganic mercury and carbon disulfide poisoning had helped prompt the development of the occupational safety and health system of Korea. Other major neurological disorders of the CNS included methyl bromide intoxication and chronic toxic encephalopathy. Most of the PNS disorders were n-hexane-induced peripheral neuritis, reported from the electronics industry. Reports of manganese-induced Parkinsonism resulted in the introduction of neuroimaging techniques to occupational medicine. Since the late 1990s, the direction of research has been moving toward degenerative disorder and early effect of neurotoxicity. To understand the early effects of neurotoxic chemicals in the preclinical stage, more follow-up studies of a longer duration are necessary.
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Affiliation(s)
- Eun-A Kim
- Occupational Safety and Health Research Institute, Korea Occupational Safety and Health Agency, Incheon, Korea.
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33
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Kim Y, Jeong KS, Song HJ, Lee JJ, Seo JH, Kim GC, Lee HJ, Kim HJ, Ahn JH, Park SJ, Kim SH, Kwon YJ, Chang Y. Altered white matter microstructural integrity revealed by voxel-wise analysis of diffusion tensor imaging in welders with manganese exposure. Neurotoxicology 2010; 32:100-9. [PMID: 21111757 DOI: 10.1016/j.neuro.2010.11.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 11/16/2010] [Accepted: 11/18/2010] [Indexed: 01/01/2023]
Abstract
Chronic exposure to manganese (Mn), which can be an occupational hazard or can result from liver failure, is associated with adverse motor and cognitive outcomes. Evidence from previous neuroimaging and magnetic resonance spectroscopy studies suggested alteration of function in Mn-exposed brains. However, the effect of chronic exposure of the human brain to Mn on white matter (WM) structure has not yet been determined. In the present study, we used diffusion tensor imaging (DTI) to investigate whether welders exposed to Mn demonstrate differences in WM integrity, compared with control subjects. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial diffusivity (RD) were measured on a voxel-wise basis in 30 male welders with exposure to Mn and in 19 age- and gender-matched control subjects. Direct comparison between welders and controls using investigator-independent Statistical Parametric Mapping (SPM) voxel-wise analysis of DTI metrics revealed a reduction of FA in the corpus callosum (CC) and frontal WM in Mn-exposed welders. Further, marked increases in RD and negligible changes in AD suggested that the microstructural changes in the CC and frontal WM result from compromised radial directionality of fibers in these areas, caused primarily by demyelination. Correlation analysis with neurobehavioral performance also suggested that the microstructural abnormalities were associated with subtle motor and cognitive differences in welders.
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Affiliation(s)
- Yangho Kim
- Department of Occupational and Environmental Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, South Korea
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Zheng W, Fu SX, Dydak U, Cowan DM. Biomarkers of manganese intoxication. Neurotoxicology 2010; 32:1-8. [PMID: 20946915 DOI: 10.1016/j.neuro.2010.10.002] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 10/04/2010] [Accepted: 10/04/2010] [Indexed: 01/30/2023]
Abstract
Manganese (Mn), upon absorption, is primarily sequestered in tissue and intracellular compartments. For this reason, blood Mn concentration does not always accurately reflect Mn concentration in the targeted tissue, particularly in the brain. The discrepancy between Mn concentrations in tissue or intracellular components means that blood Mn is a poor biomarker of Mn exposure or toxicity under many conditions and that other biomarkers must be established. For group comparisons of active workers, blood Mn has some utility for distinguishing exposed from unexposed subjects, although the large variability in mean values renders it insensitive for discriminating one individual from the rest of the study population. Mn exposure is known to alter iron (Fe) homeostasis. The Mn/Fe ratio (MIR) in plasma or erythrocytes reflects not only steady-state concentrations of Mn or Fe in tested individuals, but also a biological response (altered Fe homeostasis) to Mn exposure. Recent human studies support the potential value for using MIR to distinguish individuals with Mn exposure. Additionally, magnetic resonance imaging (MRI), in combination with noninvasive assessment of γ-aminobutyric acid (GABA) by magnetic resonance spectroscopy (MRS), provides convincing evidence of Mn exposure, even without clinical symptoms of Mn intoxication. For subjects with long-term, low-dose Mn exposure or for those exposed in the past but not the present, neither blood Mn nor MRI provides a confident distinction for Mn exposure or intoxication. While plasma or erythrocyte MIR is more likely a sensitive measure, the cut-off values for MIR among the general population need to be further tested and established. Considering the large accumulation of Mn in bone, developing an X-ray fluorescence spectroscopy or neutron-based spectroscopy method may create yet another novel non-invasive tool for assessing Mn exposure and toxicity.
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Affiliation(s)
- Wei Zheng
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA.
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35
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Chang Y, Woo ST, Lee JJ, Song HJ, Lee HJ, Yoo DS, Kim SH, Lee H, Kwon YJ, Ahn HJ, Ahn JH, Park SJ, Weon YC, Chung IS, Jeong KS, Kim Y. Neurochemical changes in welders revealed by proton magnetic resonance spectroscopy. Neurotoxicology 2009; 30:950-7. [PMID: 19631686 DOI: 10.1016/j.neuro.2009.07.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 07/13/2009] [Accepted: 07/14/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND Occupational and environmental exposure to manganese (Mn) is associated with various neurobehavioral and movement dysfunctions. However, few studies have systemically examined the neurochemical effects of Mn exposure. OBJECTIVES We examined typical changes in cerebral metabolite ratios in welders chronically exposed to Mn, compared with control individuals, using proton magnetic resonance spectroscopy (MRS), investigated whether an abnormality in brain metabolism is associated with neurobehavioral changes, and assessed possible implications of chronic Mn exposure. METHODS Thirty-five welders chronically exposed to Mn and 20 age-matched healthy subjects underwent single-voxel MRS at short echo time to assess the N-acetylaspartate (NAA), myoinositol (mI), total choline (tCho), and glutamine plus glutamate (Glx) levels, each of which was expressed as a ratio to total creatine (tCr). Neurobehavioral tests were also performed to define cognitive status. RESULTS NAA/tCr, Glx/tCr, and tCho/tCr ratios in the frontal gray matter (anterior cingulate cortex; ACC) and parietal white matter did not differ significantly between welders and control subjects. These metabolite ratios did not correlate significantly with blood Mn concentration or neurobehavioral parameters. However, mI levels in the ACC, but not in the parietal white matter, were significantly reduced in welders compared with control individuals (P<0.01). Furthermore, in the frontal lobe of the brain, the mI/tCr ratio was significantly correlated with verbal memory scores as well as blood Mn concentration (P<0.05). CONCLUSIONS The cognitive decline observed in welders exposed to Mn was associated with a decreased mI/tCr ratio in the ACC. The depletion of mI in welders may reflect possible glial cell swelling and/or detoxification processes associated with long-term exposure to Mn.
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Affiliation(s)
- Yongmin Chang
- Department of Molecular Medicine, Kyungpook National University College of Medicine, Kyungpook National University Hospital, Daegu, South Korea
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36
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Long LL, Li XR, Huang ZK, Jiang YM, Fu SX, Zheng W. Relationship between changes in brain MRI and (1)H-MRS, severity of chronic liver damage, and recovery after liver transplantation. Exp Biol Med (Maywood) 2009; 234:1075-85. [PMID: 19546351 DOI: 10.3181/0903-rm-118] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Magnetic resonance imaging (MRI) and (1)H magnetic resonance spectroscopy ((1)H-MRS) have been used in clinics for diagnosis of chronic liver diseases. This study was designed to investigate the relationship between MRI/MRS outcomes and the severity of liver damage. Of 50 patients examined, the MRI signal intensity in the globus pallidus as determined by pallidus index (PI) increased as the disease severity (scored by Child Pugh ranking) worsened (r = 0.353, P < 0.05). The changes in PI values were also linearly associated with Mn concentrations in whole blood (MnB) (r = 0.814, P < 0.01). MRS analysis of four major brain metabolites (i.e., Cho, mI, Glx, and NAA) revealed that the ratios of Cho/Cr and mI/Cr in cirrhosis and CHE patients were significantly decreased in comparison to controls (P < 0.05), whereas the ratio of Glx/Cr was significantly increased (P < 0.05). The Child Pugh scores significantly correlated with mI/Cr (-0.484, P < 0.01) and Glx (0.369, P < 0.05), as well as MnB (0.368, P < 0.05), but not with other brain metabolites. Three patients who received a liver transplant experienced normalization of brain metabolites within 3 months of post-transplantation; the MR imaging of Mn in the globus pallidus completely disappeared 5 months after the surgery. Taken together, this clinical study, which combined MRI/MRS analysis, autopsy exam and liver transplant, clearly demonstrates that liver injury-induced brain Mn accumulation can reversibly alter the homeostasis of brain metabolites Cho, mI and Glx. Our data further suggest that liver transplantation can restore normal brain Mn levels.
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Affiliation(s)
- Li-Ling Long
- Department of Radiology, the First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, China
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37
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Standridge JS, Bhattacharya A, Succop P, Cox C, Haynes E. Effect of chronic low level manganese exposure on postural balance: a pilot study of residents in southern Ohio. J Occup Environ Med 2008; 50:1421-9. [PMID: 19092498 PMCID: PMC2756152 DOI: 10.1097/jom.0b013e3181896936] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVE The objective of this study was to determine the effect of non-occupational exposure to manganese (Mn) on postural balance. METHODS Residents living near a ferromanganese refinery provided hair and blood samples after postural balance testing. The relationship between hair Mn and postural balance was analyzed with logistic regression. Following covariate adjustment, postural balance was compared with control data by analysis of covariance. RESULTS Mean hair Mn was 4.4 microg/g. A significantly positive association was found between hair Mn and sway area (eyes open on the platform, P = 0.05; eyes closed on the platform, P = 0.04) and sway length (eyes open on the platform, P = 0.05; eyes closed on the platform, P = 0.04). Postural balance of residents was significantly larger than controls in 5 out of 8 postural balance outcomes. CONCLUSION Preliminary findings suggest subclinical impairment in postural balance among residents chronically exposed to ambient Mn. A prospective study with a larger sample size is warranted.
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Affiliation(s)
- J Shawn Standridge
- Department of Environmental Health, University of Cincinnati, Cincinnati, Ohio 45267-0056, USA
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Guilarte TR, Burton NC, Verina T, Prabhu VV, Becker KG, Syversen T, Schneider JS. Increased APLP1 expression and neurodegeneration in the frontal cortex of manganese-exposed non-human primates. J Neurochem 2008; 105:1948-59. [PMID: 18284614 DOI: 10.1111/j.1471-4159.2008.05295.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Chronic manganese (Mn) exposure produces a neurological syndrome with psychiatric, cognitive, and parkinsonian features. Gene expression profiling in the frontal cortex of Cynomologous macaques receiving 3.3-5.0 mg Mn/kg weekly for 10 months showed that 61 genes were increased and four genes were decreased relative to controls from a total of 6766 genes. Gene changes were associated with cell cycle regulation, DNA repair, apoptosis, ubiquitin-proteasome system, protein folding, cholesterol homeostasis, axonal/vesicular transport, and inflammation. Amyloid-beta (Abeta) precursor-like protein 1, a member of the amyloid precursor protein family, was the most highly up-regulated gene. Immunohistochemistry confirmed increased amyloid precursor-like protein 1 protein expression and revealed the presence of diffuse Abeta plaques in Mn-exposed frontal cortex. Cortical neurons and white matter fibers from Mn-exposed animals accumulated silver grains indicative of on-going degeneration. Cortical neurons also exhibited nuclear hypertrophy, intracytoplasmic vacuoles, and apoptosis stigmata. p53 immunolabeling was increased in the cytoplasm of neurons and in the nucleus and processes of glial cells in Mn-exposed tissue. In summary, chronic Mn exposure produces a cellular stress response leading to neurodegenerative changes and diffuse Abeta plaques in the frontal cortex. These changes may explain the subtle cognitive deficits previously demonstrated in these same animals.
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Affiliation(s)
- Tomás R Guilarte
- Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland 21205, USA.
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