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Reuben A, Ward R, Rothbaum AO, Cornelison VL, Huffman S, McTeague LM, Schmidt MG, Specht AJ, Kilpatrick DG. Who tests for lead and why? A 10-year analysis of blood lead screening, follow-up and CNS outcomes in a statewide US healthcare system. Occup Environ Med 2024; 81:101-108. [PMID: 38272665 PMCID: PMC11099936 DOI: 10.1136/oemed-2023-109210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 01/09/2024] [Indexed: 01/27/2024]
Abstract
OBJECTIVES This study aims to determine (1) which providers in US healthcare systems order lead tests, why and at what frequency and (2) whether current patient population lead levels are predictive of clinical outcomes. METHODS Retrospective medical record study of all blood lead tests in the Medical University of South Carolina healthcare system 2012-2016 and consequent evidence of central nervous system (CNS)-related disease across a potential 10-year window (2012-2022). RESULTS Across 4 years, 9726 lead tests resulted for 7181 patients (49.0% female; 0-94 years), representing 0.2% of the hospital population. Most tests were for young (76.6%≤age 3) and non-Hispanic black (47.2%) and Hispanic (26.7%) patients. A wide variety of providers ordered tests; however, most were ordered by paediatrics, psychiatry, internal medicine and neurology. Lead levels ranged from ≤2.0 µg/dL (80.8%) to ≥10 µg/dL (0.8%; max 36 µg/dL). 201 children (3.1%) had initial lead levels over the reference value for case management at the time (5.0 µg/dL). Many high level children did not receive follow-up testing in the system (36.3%) and those that did often failed to see levels fall below 5.0 µg/dL (80.1%). Non-Hispanic black and Hispanic patients were more likely to see lead levels stay high or go up over time. Over follow-up, children with high lead levels were more likely to receive new attention-deficit/hyperactivity disorder and conduct disorder diagnoses and new psychiatric medications. No significant associations were found between lead test results and new CNS diagnoses or medications among adults. CONCLUSIONS Hospital lead testing covers a small portion of patients but includes a wide range of ages, presentations and provider specialities. Lack of lead decline among many paediatric patients suggests there is room to improve provider guidance around when to test and follow-up.
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Affiliation(s)
- Aaron Reuben
- Department of Psychology and Neuroscience, Duke University, Durham, North Carolina, USA
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Ralph Ward
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Alex O Rothbaum
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, Georgia, USA
| | - Vickey L Cornelison
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Sarah Huffman
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Lisa M McTeague
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Michael G Schmidt
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Aaron J Specht
- College of Health and Human Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Dean G Kilpatrick
- Department of Psychiatry and Behavioral Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
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Alam MS, Azam S, Pham K, Leyva D, Fouque KJD, Fernandez-Lima F, Miksovska J. Nanomolar affinity of EF-hands in neuronal calcium sensor 1 for bivalent cations Pb2+, Mn2+ and Hg2. Metallomics 2022; 14:6601456. [PMID: 35657675 DOI: 10.1093/mtomcs/mfac039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 05/31/2022] [Indexed: 11/12/2022]
Abstract
Abiogenic metals Pb and Hg are highly toxic since chronic and/or acute exposure often leads to severe neuropathologies. Mn2+ is an essential metal ion but in excess can impair neuronal function. In this study, we address in vitro the interactions between neuronal calcium sensor 1 (NCS1) and divalent cations. Results showed that non-physiological ions (Pb2+, Mn2+ and Hg2+) bind to EF-hands in NCS1 with nanomolar affinity and lower equilibrium dissociation constant than the physiological Ca2+ ion. (Kd,Pb2+ = 7.0±1.0 nM; Kd,Mn2+ = 34.0±6.0 nM; Kd, Hg2+ = 0.5±0.1 nM and 27.0±13.0 nM and Kd,Ca2+ = 96.0±48.0 nM). Native ultra-high resolution mass spectrometry (FT-ICR MS) and trapped ion mobility spectrometry - mass spectrometry (nESI-TIMS-MS) studies provided the NCS1-metal complex compositions - up to four Ca2+ or Mn2+ ions and three Pb2+ ions (M⋅Pb1-3Ca1-3, M⋅Mn1-4Ca1-2, and M⋅Ca1-4) were observed in complex - and similarity across the mobility profiles suggests that the overall native structure is preserved regardless of the number and type of cations. However, the non-physiological metal ions (Pb2+, Mn2+, and Hg2+) binding to NCS1 leads to more efficient quenching of Trp emission and a decrease in W30 and W103 solvent exposure compared to the apo and Ca2+ bound form, although the secondary structural rearrangement and exposure of hydrophobic sites are analogous to those for Ca2+ bound protein. Only Pb2+ and Hg2+ binding to EF-hands leads to the NCS1 dimerization whereas Mn2+ bound NCS1 remains in the monomeric form, suggesting that other factors in addition to metal ion coordination, are required for protein dimerization.
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Affiliation(s)
- Md Shofiul Alam
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA
| | - Samiol Azam
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA
| | - Khoa Pham
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA
| | - Dennys Leyva
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA
| | - Kevin Jeanne Dit Fouque
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA.,Biomolecular Sciences Institute, Florida International University, Miami, 33199USA
| | - Francisco Fernandez-Lima
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA.,Biomolecular Sciences Institute, Florida International University, Miami, 33199USA
| | - Jaroslava Miksovska
- Department of Chemistry and Biochemistry, Florida International University, Miami FL 33199USA.,Biomolecular Sciences Institute, Florida International University, Miami, 33199USA
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Neuwirth L, Okeke E, El Idrissi A. Developmental Pb 2+-Exposure induces cardiovascular pathologies in adult male rats. HEART AND MIND 2022. [DOI: 10.4103/hm.hm_73_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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4
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Cognitive Impairment Induced by Lead Exposure during Lifespan: Mechanisms of Lead Neurotoxicity. TOXICS 2021; 9:toxics9020023. [PMID: 33525464 PMCID: PMC7912619 DOI: 10.3390/toxics9020023] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/19/2021] [Accepted: 01/25/2021] [Indexed: 12/25/2022]
Abstract
Lead (Pb) is considered a strong environmental toxin with human health repercussions. Due to its widespread use and the number of people potentially exposed to different sources of this heavy metal, Pb intoxication is recognized as a public health problem in many countries. Exposure to Pb can occur through ingestion, inhalation, dermal, and transplacental routes. The magnitude of its effects depends on several toxicity conditions: lead speciation, doses, time, and age of exposure, among others. It has been demonstrated that Pb exposure induces stronger effects during early life. The central nervous system is especially vulnerable to Pb toxicity; Pb exposure is linked to cognitive impairment, executive function alterations, abnormal social behavior, and fine motor control perturbations. This review aims to provide a general view of the cognitive consequences associated with Pb exposure during early life as well as during adulthood. Additionally, it describes the neurotoxic mechanisms associated with cognitive impairment induced by Pb, which include neurochemical, molecular, and morphological changes that jointly could have a synergic effect on the cognitive performance.
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5
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Du X, Zheng W, Ye Q. Rare cases of severe life-threatening lead poisoning due to accident or chronic occupational exposure to lead and manganese: Diagnosis, treatment, and prognosis. Toxicol Ind Health 2020; 36:951-959. [PMID: 33094697 DOI: 10.1177/0748233720958969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Chronic long-term, low-dose environmental and occupational exposure to lead (Pb) has been extensively studied in large cohorts worldwide among general populations, miners, smelters, or battery workers. However, studies on severe life-threatening Pb poisoning due to accidental or chronic occupational exposure to Pb and manganese (Mn) were rarely reported. METHODS We present one case of acute severe Pb poisoning and compare it with another severe chronic occupational exposure case involving Pb and Mn. A 27-year-old woman mistakenly took a large quantity of pure Pb powder as an herbal remedy; she developed abdominal colic, severe nausea, vomiting, fatigue, and cutaneous and sclera icterus. Laboratory tests showed her blood lead level (BLL) of 173.5 µg dL-1 and urinary lead level (ULL) of 1240 µg dL-1. The patient was diagnosed with acute Pb poisoning and acute liver failure. In another chronic exposure case, a 56-year-old man worked in a Pb and Mn smelting factory for 15 years. He was brought to the emergency room with severe nausea, vomiting, and paroxysmal abdominal colic, which was intolerable during the onset of pain. His BLL was 64.8 µg dL-1 and ULL was 38 µg dL-1, but his blood and urinary Mn levels were normal. The patient was diagnosed with chronic Pb poisoning. Both patients received chelation therapy with calcium disodium ethylene-diamine-tetraacetate (CaNa2EDTA). The woman with acute severe Pb intoxication recovered well and was discharged from the hospital after treatment, and the man who survived severe Pb poisoning was diagnosed with lung cancer. CONCLUSION Clinical manifestations of acute and chronic severe Pb poisoning are different. Chelation therapy with CaNa2EDTA is proven to be an effective life-saving therapy in both cases by reducing BLL. Occupational exposure to both Pb and Mn does not appear to increase Mn neurotoxicity; however, the probability that co-exposure to Mn may increase Pb toxicity in the same patient cannot be excluded.
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Affiliation(s)
- Xuqin Du
- Department of Occupational Medicine and Toxicology, 74639Beijing Chaoyang Hospital, Capital Medical University, Beijing, China.,138262School of Health Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Wei Zheng
- 138262School of Health Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Qiao Ye
- Department of Occupational Medicine and Toxicology, 74639Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
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Azam S, Miksovska J. Pb 2+ Binds to Downstream Regulatory Element Antagonist Modulator (DREAM) and Modulates Its Interactions with Binding Partners: A Link between Neuronal Calcium Sensors and Pb 2+ Neurotoxicity. ACS Chem Neurosci 2019; 10:1263-1272. [PMID: 30399317 DOI: 10.1021/acschemneuro.8b00335] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Pb2+ exposure leads to diverse neurological disorders; however, the mechanism of Pb2+-induced neurotoxicity is not clearly understood. Here we demonstrate that Pb2+ binds to EF-hands in apo-DREAM (downstream regulatory element antagonist modulator) with a lower equilibrium dissociation constant ( Kd = 20 ± 2 nM) than Ca2+ ( Kd = 1 μM). Based on the Trp169 emission and CD spectra, we report that Pb2+ association triggers changes in the protein secondary and tertiary structures that are analogous to those previously observed for Ca2+-bound protein. The hydrophobic cavity in the C-terminal domain of DREAM is solvent exposed in the presence of Pb2+ as determined using a hydrophobic probe, 1-anilinonaphthalene-8-sulfonic acid (1,8-ANS). Pb2+ association with DREAM also modulates interactions between DREAM and its intracellular partners as evident from the fact that Pb2+-bound DREAM associates with peptide-based model systems, presenilin-1 helix-9 "PS1HL9" KV4.3(70-90) "site-2" and KV4.3(2-22) "site 1". Namely, dissociation constants for Pb2+-bound DREAM interaction with PS1HL9 ( Kd = 2.4 ± 0.1 μM), site-2 ( Kd = 11.0 ± 0.5 μM) and site 1 ( Kd = 5.0 ± 0.6 μM) are nearly identical to those observed for Ca2+ bound DREAM. Isothermal titration calorimetry data reveal that Pb2+ binds to two high-affinity sites in Ca2+ bound DREAM with the overall apparent constant of 4.81 ± 0.06 μM and its binding to Ca2+ bound DREAM is entropy-driven. Taking into account the structural and sequence similarity between DREAM and other neuronal calcium sensor (NCS) proteins, these results strongly indicate that DREAM and possibly other NCS proteins bind Pb2+ with a higher affinity than that for Ca2+ and Pb2+ interactions with NCS proteins can contribute to Pb2+-induced neurotoxicity.
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Affiliation(s)
- Samiol Azam
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
| | - Jaroslava Miksovska
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida 33199, United States
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Liang X, Csetenyi L, Gadd GM. Uranium bioprecipitation mediated by yeasts utilizing organic phosphorus substrates. Appl Microbiol Biotechnol 2016; 100:5141-5151. [PMID: 26846744 DOI: 10.1080/01490451.2015.1051639] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 01/12/2016] [Accepted: 01/14/2016] [Indexed: 05/27/2023]
Abstract
In this research, we have demonstrated the ability of several yeast species to mediate U(VI) biomineralization through uranium phosphate biomineral formation when utilizing an organic source of phosphorus (glycerol 2-phosphate disodium salt hydrate (C3H7Na2O6P·xH2O (G2P)) or phytic acid sodium salt hydrate (C6H18O24P6·xNa(+)·yH2O (PyA))) in the presence of soluble UO2(NO3)2. The formation of meta-ankoleite (K2(UO2)2(PO4)2·6(H2O)), chernikovite ((H3O)2(UO2)2(PO4)2·6(H2O)), bassetite (Fe(++)(UO2)2(PO4)2·8(H2O)), and uramphite ((NH4)(UO2)(PO4)·3(H2O)) on cell surfaces was confirmed by X-ray diffraction in yeasts grown in a defined liquid medium amended with uranium and an organic phosphorus source, as well as in yeasts pre-grown in organic phosphorus-containing media and then subsequently exposed to UO2(NO3)2. The resulting minerals depended on the yeast species as well as physico-chemical conditions. The results obtained in this study demonstrate that phosphatase-mediated uranium biomineralization can occur in yeasts supplied with an organic phosphate substrate as sole source of phosphorus. Further understanding of yeast interactions with uranium may be relevant to development of potential treatment methods for uranium waste and utilization of organic phosphate sources and for prediction of microbial impacts on the fate of uranium in the environment.
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Affiliation(s)
- Xinjin Liang
- Geomicrobiology Group, School of Life Sciences, University of Dundee, Dundee, Scotland, DD1 5EH, UK
| | - Laszlo Csetenyi
- Concrete Technology Group, Department of Civil Engineering, University of Dundee, Dundee, Scotland, DD1 4HN, UK
| | - Geoffrey Michael Gadd
- Geomicrobiology Group, School of Life Sciences, University of Dundee, Dundee, Scotland, DD1 5EH, UK.
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Correlation of brain Magnetic Resonance Imaging of spontaneously lead poisoned bald eagles (Haliaeetus leucocephalus) with histological lesions: A pilot study. Res Vet Sci 2016; 105:236-42. [DOI: 10.1016/j.rvsc.2016.02.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 12/17/2015] [Accepted: 02/21/2016] [Indexed: 11/18/2022]
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9
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Park JH, Lee DW, Park KS, Joung H. Serum trace metal levels in Alzheimer's disease and normal control groups. Am J Alzheimers Dis Other Demen 2014; 29:76-83. [PMID: 24164932 PMCID: PMC11008137 DOI: 10.1177/1533317513506778] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To determine whether serum trace metals are related to abnormal cognition in Alzheimer's disease (AD). METHODS We studied serum lead (Pb), cadmium (Cd), mercury (Hg), and arsenic(As) in 89 patients with AD and in 118 cognitively normal individuals. We analyzed the results of the blood tests and the food intake. RESULTS Serum Pb levels correlated with word list recall (P = .039) and word list recognition (P = .037). Without age adjustment, serum Cd levels (P = .044) were significantly higher in the AD group. After stratified age adjustment, the levels of selected trace metals did not differ significantly between AD and normal individuals. Food intakes regarding selected trace metals were not significantly different between the 2 groups. CONCLUSIONS In this study, serum Pb, Cd, Hg, and As levels were not directly related to abnormal cognition in AD. Serum Pb levels were significantly negatively correlated with verbal memory scores.
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Affiliation(s)
- Jun-Hyun Park
- Department of Psychiatry, Sanggye Paik Hospital, College of Medicine, Inje University, Seoul, Korea
| | - Dong-Woo Lee
- Department of Psychiatry, Sanggye Paik Hospital, College of Medicine, Inje University, Seoul, Korea
| | - Kyung Su Park
- Advanced Analysis Center, Korea Institute of Science and Technology, Seoul, Korea
| | - HyoJee Joung
- Department of Public Health, Graduate School of Public Health & Institute of Health and Environment, Seoul National University, Seoul, Korea
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10
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Ji JS, Elbaz A, Weisskopf MG. Association between blood lead and walking speed in the National Health and Nutrition Examination Survey (NHANES 1999-2002). ENVIRONMENTAL HEALTH PERSPECTIVES 2013; 121:711-6. [PMID: 23603014 PMCID: PMC3672915 DOI: 10.1289/ehp.1205918] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 04/18/2013] [Indexed: 05/12/2023]
Abstract
BACKGROUND Walking speed is a simple and reliable measure of motor function that is negatively associated with adverse health events in older people, including falls, disability, hospital admissions, and mortality. Lead has adverse affects on human health, particularly on the vascular and neurological systems. OBJECTIVE We explored the hypothesis that lead is associated with slower walking speed. METHODS We used U.S. National Health and Nutrition Examination Survey (NHANES) cross-sectional data from 1999-2002. The time to walk 20 ft (walking speed) was measured among 1,795 men and 1,798 women ≥ 50 years of age. The association between walking speed and quintiles of blood lead concentration was estimated separately in men and women using linear regression models adjusted for age, education, ethnicity, alcohol use, smoking status, height, and waist circumference. RESULTS Mean blood lead concentrations and walking speeds were 2.17 μg/dL and 3.31 ft/sec in women, and 3.18 μg/dL and 3.47 ft/sec in men, respectively. Among women, walking speed decreased with increasing quintiles of blood lead, resulting in an estimated mean value that was 0.11 ft/sec slower (95% CI: -0.19, -0.04; p-trend = 0.005) for women with blood lead concentrations in the highest versus lowest quintile. In contrast, lead was not associated with walking speed in men. CONCLUSION Blood lead concentration was associated with decreased walking speed in women, but not in men. Our results contribute to the growing evidence that lead exposure, even at low levels, is detrimental to public health.
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Affiliation(s)
- John S Ji
- Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts 02215, USA
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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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12
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Guilarte TR, Opler M, Pletnikov M. Is lead exposure in early life an environmental risk factor for Schizophrenia? Neurobiological connections and testable hypotheses. Neurotoxicology 2012; 33:560-74. [PMID: 22178136 PMCID: PMC3647679 DOI: 10.1016/j.neuro.2011.11.008] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 11/30/2011] [Accepted: 11/30/2011] [Indexed: 02/06/2023]
Abstract
Schizophrenia is a devastating neuropsychiatric disorder of unknown etiology. There is general agreement in the scientific community that schizophrenia is a disorder of neurodevelopmental origin in which both genes and environmental factors come together to produce a schizophrenia phenotype later in life. The challenging questions have been which genes and what environmental factors? Although there is evidence that different chromosome loci and several genes impart susceptibility for schizophrenia; and epidemiological studies point to broad aspects of the environment, only recently there has been an interest in studying gene × environment interactions. Recent evidence of a potential association between prenatal lead (Pb(2+)) exposure and schizophrenia precipitated the search for plausible neurobiological connections. The most promising connection is that in schizophrenia and in developmental Pb(2+) exposure there is strong evidence for hypoactivity of the N-methyl-d-aspartate (NMDA) subtype of excitatory amino acid receptors as an underlying neurobiological mechanism in both conditions. A hypofunction of the NMDA receptor (NMDAR) complex during critical periods of development may alter neurobiological processes that are essential for brain growth and wiring, synaptic plasticity and cognitive and behavioral outcomes associated with schizophrenia. We also describe on-going proof of concept gene-environment interaction studies of early life Pb(2+) exposure in mice expressing the human mutant form of the disrupted in schizophrenia 1 (DISC-1) gene, a gene that is strongly associated with schizophrenia and allied mental disorders.
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Affiliation(s)
- Tomás R Guilarte
- Department of Environmental Health Sciences, Columbia University Mailman School of Public Health, New York, NY 10032, United States.
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Guimarães D, Carvalho ML, Geraldes V, Rocha I, Santos JP. Study of lead accumulation in bones of Wistar rats by X-ray fluorescence analysis: aging effect. Metallomics 2012; 4:66-71. [DOI: 10.1039/c1mt00149c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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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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Hsieh TJ, Chen YC, Li CW, Liu GC, Chiu YW, Chuang HY. A proton magnetic resonance spectroscopy study of the chronic lead effect on the Basal ganglion and frontal and occipital lobes in middle-age adults. ENVIRONMENTAL HEALTH PERSPECTIVES 2009; 117:941-945. [PMID: 19590687 PMCID: PMC2702410 DOI: 10.1289/ehp.0800187] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2008] [Accepted: 02/09/2009] [Indexed: 05/28/2023]
Abstract
BACKGROUND Lead is known to be a health hazard to the human brain and nervous system based on data from epidemiologic studies. However, few studies have examined the mechanism or biochemical changes caused by lead in the human brain, although recently some have used magnetic resonance spectroscopy (MRS) to test brain metabolism in vivo. OBJECTIVES In this study, we used 3-T MRS to investigate brain metabolism in workers chronically exposed to lead and matched nonexposed controls. METHODS Twenty-two workers at a lead paint factory served as chronically exposed subjects of this study. These workers did not have any clinical syndromes. Eighteen age- and sex-matched nonexposed healthy volunteers served as controls. We measured blood and bone lead and used a 3-T MRS to measure their levels of brain N-acetyl aspartate (NAA), choline (Cho), and total creatine (tCr). A structural questionnaire was used to collect demographic, work, and health histories and information about their life habits. RESULTS All the MRS measures were lower in the lead-exposed group. Increased blood and bone lead levels correlated with declines in Cho:tCr ratios, especially in the occipital lobe, where changes in all gray, subcortical, and white matter were significant. Increases in blood and patella lead in every layer of the frontal lobe correlated with significant decreases in NAA:tCr ratios. One of the strongest regression coefficients was -0.023 (SE = 0.005, p < 0.001), which was found in the NAA:tCr ratio of frontal gray matter. DISCUSSION We conclude that chronic exposure to lead might upset brain metabolism, especially NAA:tCr and Cho:tCr ratios. Brain NAA and Cho are negatively correlated to blood and bone lead levels, suggesting that lead induces neuronal and axonal damage or loss. The most significant changes occurred in frontal and occipital lobes, areas in which previous neurobehavioral studies have shown memory and visual performance to be adversely affected by lead toxicity.
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Affiliation(s)
| | - Yi-Chun Chen
- Department of Community Medicine, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
| | - Chun-Wei Li
- Department of Medical Imaging and Radiation Technology, College of Health Sciences and
| | - Gin-Chang Liu
- Department of Medical Imaging and
- Department of Radiology, College of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan
| | - Yu-Wen Chiu
- Department of Community Medicine, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
| | - Hung-Yi Chuang
- Department of Community Medicine, Kaohsiung Medical University Hospital, Kaohsiung City, Taiwan
- Department of Public Health, College of Health Sciences, and Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan
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Struzyńska L. A glutamatergic component of lead toxicity in adult brain: the role of astrocytic glutamate transporters. Neurochem Int 2009; 55:151-6. [PMID: 19428820 DOI: 10.1016/j.neuint.2009.01.025] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2008] [Revised: 01/20/2009] [Accepted: 01/21/2009] [Indexed: 11/28/2022]
Abstract
Astroglial cells have a variety of roles in the central nervous system (CNS), providing a homeostasis for the proper functioning of neuronal cells. The classical view concerning the supportive role of astroglia towards associated neurons has to be extended. A great number of new evidences suggest that astrocytes interact closely with neurons being involved in the active control of neuronal activity and metabolism, forming with pre- and postsynaptic nerve terminals a tripartite synapse. Astrocytes control many aspects of brain function. Regulation of extracellular glutamate concentration, potentially neurotoxic neurotransmitter, is fundamental. Glial glutamate transporters system is of importance in protection against glutamate excitotoxicity and antioxidant defence system which is glutathione. When astrocytes fail to function properly, they influence the degree of neuronal damage. Thus, astrocytes are involved to a very great extent into numerous brain pathologies, including toxicity of heavy metals, like lead (Pb). Under pathological conditions they appear to express two opposite features: they are neuroprotective (until they can) or deleterious for neurons and may participate in neuronal damage. The very well known affinity of Pb to astroglia and the changes in glutamatergic transmission upon Pb toxicity, led us to discuss the role of astroglia and astrocytic glutamate transporters in the neurotoxicity of this metal. Our observations are viewed against a background of other results.
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Affiliation(s)
- Lidia Struzyńska
- Department of Neurochemistry, Laboratory of Pathoneurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.
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Bellinger DC. Lead neurotoxicity in children: decomposing the variability in dose-effect relationships. Am J Ind Med 2007; 50:720-8. [PMID: 17290364 DOI: 10.1002/ajim.20438] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Enormous progress has been made in recent decades in our understanding of lead neurotoxicology in children, but an important obstacle to additional progress is the striking variability that is evident in any plot of a lead biomarker versus a health endpoint. METHODS In this article, three potential sources of variability are identified: (1) errors or imprecision in characterizing dose (and/or outcome); (2) incomplete characterization of endpoint variance attributable to factors other than lead; and (3) inter-individual differences in susceptibility to lead neurotoxicity. RESULTS Strategies are suggested for reducing the variability contributed by these sources, including the development of validated PBPK models and biomarkers of early biological effects; the development of more comprehensive models of outcome variance and, specifically, the application of multi-level models that incorporate supra-individual and supra-family risk factors; and the use of study designs that permit assessments of the effect modifying influence of contextual factors on the form and severity of neurotoxicity. CONCLUSION Decomposing the variability in the distribution of observed scores around the best-fit lines that describe the dose-effect relationships for lead neurotoxicity in children is a major research need.
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Affiliation(s)
- David C Bellinger
- Department of Neurology, Children's Hospital Boston and Harvard Medical School, Boston, MA, USA.
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Weisskopf MG, Hu H, Sparrow D, Lenkinski RE, Wright RO. Proton magnetic resonance spectroscopic evidence of glial effects of cumulative lead exposure in the adult human hippocampus. ENVIRONMENTAL HEALTH PERSPECTIVES 2007; 115:519-23. [PMID: 17450218 PMCID: PMC1852692 DOI: 10.1289/ehp.9645] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Accepted: 01/03/2007] [Indexed: 05/13/2023]
Abstract
BACKGROUND Exposure to lead is known to have adverse effects on cognition in several different populations. Little is known about the underlying structural and functional correlates of such exposure in humans. OBJECTIVES We assessed the association between cumulative exposure to lead and levels of different brain metabolite ratios in vivo using magnetic resonance spectroscopy (MRS). METHODS We performed MRS on 15 men selected from the lowest quintile of patella bone lead within the Department of Veterans Affairs' Normative Aging Study (NAS) and 16 from the highest to assess in the hippocampal levels of the metabolites N-acetylaspartate, myoinositol, and choline, each expressed as a ratio with creatine. Bone lead concentrations-indicators of cumulative lead exposure-were previously measured using K-X-ray fluorescence spectroscopy. MRS was performed on the men from 2002 to 2004. RESULTS A 20-microg/g bone and 15-microg/g bone higher patella and tibia bone lead concentration--the respective interquartile ranges within the whole NAS--were associated with a 0.04 [95% confidence interval (CI), 0.00-0.08; p = 0.04] and 0.04 (95% CI, 0.00-0.08; p = 0.07) higher myoinositol-to-creatine ratio in the hippocampus. After accounting for patella bone lead declines over time, analyses adjusted for age showed that the effect of a 20-microg/g bone higher patella bone lead level doubled (0.09; 95% CI, 0.01-0.17; p = 0.03). CONCLUSIONS Cumulative lead exposure is associated with an increase in the myinositol-to-creatine ratio. These data suggest that, as assessed with MRS, glial effects may be more sensitive than neuronal effects as an indicator of cumulative exposure to lead in adults.
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Affiliation(s)
- Marc G Weisskopf
- Department of Environmental Health, Occupational Health Program, Harvard School of Public Health, 401 Park Drive, Boston, MA 02215, USA.
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Abstract
The study of neurological impacts of toxicants has emphasized neuropsychological tests as important outcome variables. Direct assessment of neural substrates of environmental impacts could offer many advantages. I discuss our use of magnetic resonance spectroscopy (MRS) in the neurological assessment of adult lead poisoning of monozygotic twins as an example. Cognitive testing showed frontal lobe dysfunction in both twins, and more dramatic hippocampal dysfunction in the twin with higher lead exposure (JG). MRS showed lower N-acetylaspartate/creatine ratios in JG. The findings illustrate the potential utility of MRS in assessing impacts of not only lead, but other toxicants as well.
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Affiliation(s)
- Marc G Weisskopf
- Department of Environmental Health, Harvard School of Public Health, Occupational Health Program, Landmark Center, 401 Park Dr., P.O. Box 15697, Boston, MA 02215, USA.
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Bhattacharya A, Shukla R, Dietrich KN, Bornschein RL. Effect of early lead exposure on the maturation of children's postural balance: A longitudinal study. Neurotoxicol Teratol 2006; 28:376-85. [PMID: 16624520 DOI: 10.1016/j.ntt.2006.02.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2005] [Revised: 02/17/2006] [Accepted: 02/23/2006] [Indexed: 10/24/2022]
Abstract
This prospective study investigated the impact of early exposure to lead on the maturation of children's postural balance. The effect of lead exposure on age-associated maturation of postural balance was investigated on 91 children from the Cincinnati Lead Study (CLS) with a 5-year geometric mean lead concentration in blood of 11.66 microg/dL (range 3.89-28.33 microg/dL) by re-assessing their postural balance approximately every 20 months starting at mean age of 6.6 years through mean age of 12.1 years. The results presented in this paper provide evidence that low to moderate lead exposure in early childhood has a measurable and statistically significant impact on the maturation of postural balance. In comparison to less exposed children, of those in the higher lead group showed an impaired postural balance response. The results from this study suggest that children with early childhood lead exposure may need additional time to approach (or "catch up" with) their maturational postural balance status. As these subjects are now adults in their early to mid-twenties, poor postural balance may impact their daily living tasks and pose a higher risk of potential injuries at home and work.
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Affiliation(s)
- Amit Bhattacharya
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0056, USA.
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Basha MR, Murali M, Siddiqi HK, Ghosal K, Siddiqi OK, Lashuel HA, Ge YW, Lahiri DK, Zawia NH. Lead (Pb) exposure and its effect on APP proteolysis and Aβ aggregation. FASEB J 2005; 19:2083-4. [PMID: 16230335 DOI: 10.1096/fj.05-4375fje] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder with clinical manifestations appearing in old age, however, the initial stages of this disease may begin early in life. AD is characterized by the presence of excessive deposits of aggregated beta-amyloid (Abeta) peptides, which are derived from the beta-amyloid precursor protein (APP) following processing by beta-secretase and gamma-secretase. Recently, we have reported that developmental exposure of rats to Pb resulted in latent elevation of APP mRNA, APP, and Abeta in old age. Here we examined whether latent up-regulation in APP expression and Abeta levels is exacerbated by concurrent disturbances in APP processing or Abeta aggregation. Among the environmental metals tested, only Abeta solutions containing Pb promoted the formation of Abeta aggregates at nanomolar concentrations. The lifetime profiles of alpha-, beta-, and gamma-secretases remained constant in adult and aging animals, and developmental exposure to Pb did not alter them. Furthermore, the addition of various concentrations of Pb (0.1 to 50 microM) to cerebral cortical extracts derived from control animals also did not affect the proteolytic activities of these enzymes. Therefore, we propose that amyloidogenesis is promoted by a latent response to developmental reprogramming of the expression of the APP gene by early exposure to Pb, as well as enhancement of Abeta aggregation in old age. In rodents, these events occur without Pb-induced disturbances to the enzymatic processing of APP. The aforementioned results provide further evidence for the developmental basis of amyloidogenesis and late-life disturbances in AD-associated proteins by environmental agents.
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Affiliation(s)
- Md Riyaz Basha
- Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
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Struzyńska L, Chalimoniuk M, Sulkowski G. Changes in expression of neuronal and glial glutamate transporters in lead-exposed adult rat brain. Neurochem Int 2005; 47:326-33. [PMID: 15985313 DOI: 10.1016/j.neuint.2005.05.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 05/12/2005] [Accepted: 05/12/2005] [Indexed: 11/24/2022]
Abstract
Excitatory amino acid transporters (EAATs) are membrane-bound proteins localized in glial and neuronal cells which transport glutamate (Glu) in a process essential for terminating its action and protecting neurons from excitotoxic damage. Since Pb-induced neurotoxicity has a glutamatergic component and astrocytes serve as a cellular Pb deposition site, it was of interest to investigate the response of main glutamate transporters to short-term lead exposure in the adult rat brain (25mg/kg b.w. of lead acetate, i.p. for 3 days). We examined the expression of mRNA and protein of GLAST, GLT-1 and EAAC1 in homogenates obtained from cerebellum, hippocampus and forebrain. Molecular evidence is provided which indicates that, of the two glial transporters, GLT-1 is more susceptible than GLAST to the neurotoxic effect arising from Pb. RT-PCR analysis revealed highly decreased expression of GLT-1 mRNA in forebrain and hippocampus. In contrast, GLAST was overexpressed in forebrain and in cerebellum. In the case of EAAC1, the enhanced expression of mRNA and protein of transporter was observed only in forebrain. The results demonstrate regional differences in the expression of glutamate transporters after short-term exposure to Pb. In forebrain, downregulation of GLT-1 is compensated by enhanced expression of GLAST, while in hippocampus, the expression of both is lowered. This observation suggests that under conditions of Pb toxicity in adult rat brain, the hippocampus is most vulnerable to the excitotoxic cell damage arising from impaired clearance of the released glutamate.
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Affiliation(s)
- Lidia Struzyńska
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland.
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Lasky RE, Luck ML, Parikh NA, Laughlin NK. The Effects of Early Lead Exposure on the Brains of Adult Rhesus Monkeys: A Volumetric MRI Study. Toxicol Sci 2005; 85:963-75. [PMID: 15788724 DOI: 10.1093/toxsci/kfi153] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Little is known about direct effects of exposure to lead on central nervous system development. We conducted volumetric MRI studies in three groups of 17-year-old rhesus monkeys: (1) a group exposed to lead throughout gestation (n = 3), (2) a group exposed to lead through breast milk from birth to weaning (n = 4), and (3) a group not exposed to lead (n = 8). All fifteen monkeys were treated essentially identically since birth with the exception of lead exposure. The three-dimensional MRI images were segmented on a computer workstation using pre-tested manual and semi-automated algorithms to generate brain volumes for white matter, gray matter, cerebrospinal fluid, and component brain structures. The three groups differed significantly in the adjusted (for total brain size) volumes of the right cerebral white matter and the lateral ventricles. A significant reduction was noted in right cerebral white matter in prenatally exposed monkeys as compared to controls (p = 0.045). A similar reduction was detected in the white matter of the contralateral hemisphere; however, this difference did not achieve statistical significance (p = 0.143). Prenatally exposed monkeys also had larger right (p = 0.027) and left (p = 0.040) lateral ventricles. Depending on the timing of exposure during development, lead may exhibit differential effects with resultant life-long alterations in brain architecture.
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Affiliation(s)
- Robert E Lasky
- Center for Clinical Research and Evidence Based Medicine, The University of Texas-Houston Medical School, 6431 Fannin Street, MSB 2.104, Houston, Texas 77030, USA.
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