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Garnier R, Nouyrigat E, Benoit P, Goullé JP, Granon C, Manel J, Manouchehri N, Mathieu-Huart A, Nisse P, Normand JC, Ronga-Pézeret S, Roulet A, Simon F, Gabach P, Tournoud C, Augé G, Barbillon A, Boudet C, Bourgeat M, Droissart-Long A, El Balkhi S, Franchitto N, Glaizal M, Glorennec P, Gnansia E, Haufroid V, Breurec JY, Cambier P, Carlier P, Carretier J, Chanaud D, Charrière A, Clinard F, Dereure O, Kleinlogel S, Labadie M, Laporte R, Heilier JF, Javelaud B, Lefranc A, Lelièvre B, Lucas D, Marot F, Mathieu O, Nesslany F, Nikolova-Pavageau N, Nisse C, Peronnet K, Puskarczyk E, Quénel P, Rauzier-Jaoul MC, Roussel H, Sadeg N, Sapori JM, Sauvant-Rochat MP, Verdun-Esquer C, Veyer K, Villa A, Vircondelet S. Dépistage, prise en charge et suivi des personnes potentiellement surexposées à l’arsenic inorganique du fait de leur lieu de résidence. ARCH MAL PROF ENVIRO 2020. [DOI: 10.1016/j.admp.2020.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Moghadam AT, Bahreini M, Anzali BC. Opium-Related Lead Toxicity: An Integrative Review and Case Series. J Emerg Med 2020; 59:33-45. [PMID: 32414545 DOI: 10.1016/j.jemermed.2020.04.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 03/31/2020] [Accepted: 04/08/2020] [Indexed: 01/17/2023]
Abstract
BACKGROUND Restrictive regulations and the increased price of opioids have resulted in the addition of impurities to illicit opioids by drug dealers. Among the adulterants, lead salts are optimal agents to make packages heavier. Consequently, lead toxicity has emerged in the opioid-user population. OBJECTIVES Our goal was to review the related literature and describe patients with common presentations of opioid-related lead poisoning to provide a basis to prepare optimal management. METHODS A narrative review was performed aiming to study opioid lead poisoning. PubMed and Google Scholar databases were explored with two Medical Subject Heading terms, lead poisoning and substance-related disorders to find a broad but relevant spectrum of articles. Then, the reference lists within those articles were checked to upgrade our literature pool on this issue. RESULTS Ultimately, among English-language articles, 16 were case series and case reports of patients with lead intoxication after opioid consumption. Data pertaining to disease characteristics, diagnosis, and treatment protocols were extracted. CONCLUSIONS The clinical presentation of opioid lead intoxication can vary from rather asymptomatic to severely debilitating gastrointestinal or neurologic symptoms. The diagnosis is made by checking lead blood levels after obviating other critical diagnoses and should be considered in each drug user in endemic regions of opioid addiction, such as the Middle East. Management protocols are suggested to cover both features of opioid-related complications and lead toxicity.
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Affiliation(s)
- Ali Tafazoli Moghadam
- Department of Clinical Pharmacy, Faculty of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Maryam Bahreini
- Department of Emergency Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Gaitens JM, Potter BK, D'Alleyrand JG, Overmann AL, Gochfeld M, Smith DR, Breyer R, McDiarmid MA. The management of embedded metal fragment patients and the role of chelation Therapy: A workshop of the Department of Veterans Affairs-Walter Reed National Medical Center. Am J Ind Med 2020; 63:381-393. [PMID: 32144801 DOI: 10.1002/ajim.23098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 02/10/2020] [Accepted: 02/21/2020] [Indexed: 01/12/2023]
Abstract
Exposure to retained metal fragments from war-related injuries can result in increased systemic metal concentrations, thereby posing potential health risks to target organs far from the site of injury. Given the large number of veterans who have retained fragments and the lack of clear guidance on how to medically manage these individuals, the Department of Veterans Affairs (VA) convened a meeting of chelation experts and clinicians who care for embedded fragment patients to discuss current practices and provide medical management guidance. Based on this group's clinical expertise and review of published literature, the evidence presented suggests that, at least in the case of lead fragments, short-term chelation therapy may be beneficial for embedded fragment patients experiencing acute symptoms associated with metal toxicity; however, in the absence of clinical symptoms or significantly elevated blood lead concentrations (greater than 80 µg/dL), chelation therapy may offer little to no benefit for individuals with retained fragments and pose greater risks due to remobilization of metals stored in bone and other soft tissues. The combination of periodic biomonitoring to assess metal body burden, longitudinal fragment imaging, and selective fragment removal when metal concentrations approach critical injury thresholds offers a more conservative management approach to caring for patients with embedded fragments.
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Affiliation(s)
- Joanna M. Gaitens
- Department of Veterans Affairs Medical Center Baltimore and Department of MedicineUniversity of Maryland School of MedicineBaltimore Maryland
| | - Benjamin K. Potter
- Department of OrthopaedicsWalter Reed National Military Medical CenterBethesda Maryland
| | | | - Archie L. Overmann
- Department of OrthopaedicsWalter Reed National Military Medical CenterBethesda Maryland
| | - Michael Gochfeld
- Department of Environmental and Occupational Health, Environmental and Occupational Health Sciences InstituteRutgers Robert Wood Johnson Medical SchoolPiscataway New Jersey
| | - Donald R. Smith
- Department of Microbiology and Environmental ToxicologyUniversity of CaliforniaSanta Cruz California
| | - Richard Breyer
- Department of RadiologyBaltimore Veterans Affairs Medical CenterBaltimore Maryland
| | - Melissa A. McDiarmid
- Department of Veterans Affairs Medical Center Baltimore and Department of MedicineUniversity of Maryland School of MedicineBaltimore Maryland
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Huali T, Honglei P, Feng W, Shaokang W, Ligang Y, Jianghong L, Guiju S. Effects of combined administration of calcium, iron, zinc, chrysanthemum flavonoids, and DMSA on the treatment of lead intoxication in mice. J Biochem Mol Toxicol 2020; 34:e22425. [PMID: 31729815 DOI: 10.1002/jbt.22425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 09/03/2019] [Accepted: 10/30/2019] [Indexed: 11/06/2022]
Abstract
The effect of combined administration of calcium (Ca), iron (Fe), zinc (Zn), chrysanthemum flavonoids, and meso-2,3-dimercaptosuccinic acid (DMSA) on the treatment of lead (Pb) intoxication in mice was studied. One hundred ninety female mice (SPF level, aged 18-22 days) were randomly divided into two groups as experimental animals. Mice in group I (10 mice) served as normal control animals, and were administered deionized water containing 12.5 μL/L acetate acid for 6 weeks, whereas mice in group II (180 mice) were exposed to 0.1% (wt/vol) of lead acetate in deionized water for 6 weeks and served as experimental animals. After 6 weeks of successful modeling, 180 mice from group II (lead-exposed) were divided into 18 groups of 10 mice each, 16 of which were treated by the combined administration of Ca, Fe, Zn, chrysanthemum flavonoids, and DMSA by L16 (215 ) orthogonal design. The remaining two groups were given treatment with low and high doses of DMSA, respectively. After three weeks of intervention (ig), the optimal treatment group was identified according to its blood lead level, as well as some antioxidant indices in the blood, liver, and hippocampus. The results indicated that the combined administration of Fe, Zn, chrysanthemum flavonoids, and DMSA with low dosage had the most significant effect on increasing the activities of blood delta-aminolevulinic acid dehydratase and superoxide dismutase (SOD), hepatic SOD and hippocampus nitric oxide synthase while decreasing the blood lead level, the content of hepatic malondialdehyde and hippocampus nitric oxide; this was considered the optimal treatment group. There was no difference in the level of blood hemoglobin between the optimal treatment group and the model control group (the first group of the orthogonal experiment). The activities of blood glutathione (GSH), hepatic GSH and glutathione peroxidase of the optimal treatment group were the same as other groups', and the recovery of the related indexes in the optimal effect group closely resembled the high dosage DMSA group. It can be concluded that the coadministration of Fe, Zn, and chrysanthemum flavonoids along with a low-dose DMSA effectively reduces Pb poisoning and lead-induced oxidative damage in lead-exposed mice; the result may provide a theoretical reference for the treatment of Pb poisoning.
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Affiliation(s)
- Tang Huali
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Nutrition and Food Hygiene, School of Public Health, Southeast University, Nanjing, China
- College of Biology and Food Engineering, Chongqing Three Gorges University, Chongqing, China
| | - Peng Honglei
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Nutrition and Food Hygiene, School of Public Health, Southeast University, Nanjing, China
- Jiangsu General Administration of Market Supervision and Administration, Nanjing, China
| | - Wang Feng
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Nutrition and Food Hygiene, School of Public Health, Southeast University, Nanjing, China
| | - Wang Shaokang
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Nutrition and Food Hygiene, School of Public Health, Southeast University, Nanjing, China
| | - Yang Ligang
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Nutrition and Food Hygiene, School of Public Health, Southeast University, Nanjing, China
| | - Liu Jianghong
- School of Nursing and School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Sun Guiju
- Key Laboratory of Environmental Medicine and Engineering of Ministry of Education, Department of Nutrition and Food Hygiene, School of Public Health, Southeast University, Nanjing, China
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Sakthithasan K, Lévy P, Poupon J, Garnier R. A comparative study of edetate calcium disodium and dimercaptosuccinic acid in the treatment of lead poisoning in adults. Clin Toxicol (Phila) 2018; 56:1143-1149. [PMID: 29889577 DOI: 10.1080/15563650.2018.1478424] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
BACKGROUND We evaluated the efficacy of two antidotes, edetate calcium disodium (CaNa2EDTA) and dimercaptosuccinic acid (DMSA), for the treatment of lead poisoning in adults. METHODS Thirty-seven patients with blood lead concentrations >40 μg/dL and positive CaNa2EDTA lead mobilization were randomized to receive 1050 mg/m2/day of oral DMSA (n = 21) or 500 mg/m2/day of intravenous CaNa2EDTA (n = 16) over two five-day courses separated by a 10-day rest period. Efficacy of treatment was evaluated by blood lead assays on the first day of the two courses and 14 days after the end of treatment and baseline CaNa2EDTA lead mobilization test and 14 days after the end of treatment. RESULTS AND CONCLUSION Both treatments significantly reduced the prevalence of clinical symptoms, blood lead levels and CaNa2EDTA lead mobilization and were well tolerated. DMSA had a greater impact on reducing blood lead concentrations (p = .005) and CaNa2EDTA on lead mobilization (p = .04). Comparison of equimolar doses showed that CaNa2EDTA was more effective than DMSA (p < .001).
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Affiliation(s)
- Kirushanthi Sakthithasan
- a Department of Environmental and Occupational Health , Fernand Widal Hospital, APHP , Paris , France
| | - Pierre Lévy
- b Department of Public Health , Tenon Hospital, APHP, Sorbonne University and INSERM, UMR-S 1136 (EPAR Team) , Paris , France
| | - Joël Poupon
- c Toxicology Laboratory , Lariboisière Hospital, APHP , Paris , France
| | - Robert Garnier
- a Department of Environmental and Occupational Health , Fernand Widal Hospital, APHP , Paris , France
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Bjørklund G, Mutter J, Aaseth J. Metal chelators and neurotoxicity: lead, mercury, and arsenic. Arch Toxicol 2017; 91:3787-3797. [DOI: 10.1007/s00204-017-2100-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 10/19/2017] [Indexed: 01/07/2023]
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Ayyathan DM, Chandrasekaran R, Thiagarajan K. Neuroprotective effect of Tagara, an Ayurvedic drug against methyl mercury induced oxidative stress using rat brain mitochondrial fractions. Altern Ther Health Med 2015; 15:268. [PMID: 26264039 PMCID: PMC4533944 DOI: 10.1186/s12906-015-0793-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 07/22/2015] [Indexed: 11/10/2022]
Abstract
BACKGROUND Methyl mercury (MeHg), an important environmental toxicant is implicated in neurological disorders such as Hunter-Russell syndrome and Autism. Therefore, the present work is in search of new drugs that can alleviate MeHg toxicity. In this connection, Tagara, an ayurvedic drug is used for assessing its neuro protective effect against MeHg toxicity. METHODS In the present study, we assessed the phytochemical contents of Tagara by colorimetric and HPLC analyses. The neuroprotective effect of Tagara on MeHg induced neurotoxicity was measured in terms of viability by MTT assay and oxidative stress in terms of catalase activity, glutathione and thiobarbituric acid reactive substance levels. Further, the chelating effect of Tagara towards MeHg was performed to identify the molecular mechanism. Statistical analysis was done by statistical package for social sciences (SPSS) version 16.0. RESULTS The results demonstrated that Tagara contains significant amounts of phenols and flavonoids. Also, HPLC analysis of Tagara revealed the presence of essential oils such as hydroxyvalerenic and valerenic acids. Our results demonstrated that exposure of rat brain mitochondrial fractions to MeHg resulted in a dose dependent death in MTT assay and IC50 value was found to be 10 μM. However, a 250 μg dose of Tagara effectively prevented MeHg induced mitochondrial damage. The oxidative stress caused by MeHg results in elevated levels of reactive oxygen species as evidenced by elevated TBARS (Thiobarbituric acid-reactive substances) levels and diminished catalase enzyme activity and glutathione content. However, Tagara at 250 μg concentration offsets these alterations caused by MeHg. Further, Tagara also diminished GSH oxidation caused by MeHg, confirming its chelating effect, one of the molecular mechanisms that triggers protection against oxidative damage. CONCLUSION Our results revealed that MeHg induced toxicity is predominantly mediated through oxidative stress mechanism and the propensity of Tagara to abolish such reactions. Hence, we propose that Tagara with a source of potential neuroprotectants may be a useful approach to alleviate MeHg associated neurotoxicity.
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Gui R, Jin H, Wang Z, Tan L. Recent advances in synthetic methods and applications of colloidal silver chalcogenide quantum dots. Coord Chem Rev 2015. [DOI: 10.1016/j.ccr.2015.03.023] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Cao Y, Skaug MA, Andersen O, Aaseth J. Chelation therapy in intoxications with mercury, lead and copper. J Trace Elem Med Biol 2015; 31:188-92. [PMID: 24894443 DOI: 10.1016/j.jtemb.2014.04.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 04/22/2014] [Accepted: 04/23/2014] [Indexed: 11/15/2022]
Abstract
In the present review we provide an update of the appropriate use of chelating agents in the treatment of intoxications with compounds of mercury, lead and copper. The relatively new chelators meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercapto-propanesulphonate (DMPS) can effectively mobilize deposits of mercury as well as of lead into the urine. These drugs can be administered orally and have relatively low toxicity compared to the classical antidote dimercaptopropanol (BAL). d-Penicillamine has been widely used in copper overload, although 2,3-dimercaptosuccinic acid or tetrathiomolybdate may be more suitable alternatives today. In copper-toxicity, a free radical scavenger might be recommended as adjuvant to the chelator therapy.
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Affiliation(s)
- Yang Cao
- Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Marit Aralt Skaug
- Faculty of Public Health, Hedmark University College, Elverum, Norway.
| | - Ole Andersen
- Department of Science, Systems and Models, Roskilde University, Roskilde, Denmark
| | - Jan Aaseth
- Innlandet Hospital Trust, Kongsvinger Hospital Division, Kongsvinger, Norway
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Hocaoglu I, Demir F, Birer O, Kiraz A, Sevrin C, Grandfils C, Acar HY. Emission tunable, cyto/hemocompatible, near-IR-emitting Ag2S quantum dots by aqueous decomposition of DMSA. NANOSCALE 2014; 6:11921-11931. [PMID: 25175037 DOI: 10.1039/c4nr02935f] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Size tunable aqueous Ag2S quantum dots emitting in the near-infrared region were synthesized through decomposition of meso-2,3-dimercaptosuccinic acid (DMSA) in water. The resulting NIR QDs are highly cyto- and hemocompatible, have quantum yields as high as 6.5% and are effective optical imaging agents based on in vitro evaluation.
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Affiliation(s)
- Ibrahim Hocaoglu
- Koc University, Graduate School of Materials Science and Engineering, Rumelifeneri Yolu, Sarıyer, 34450, Istanbul, Turkey.
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Ayyathan DM, Chandrasekaran R, Thiagarajan K. Neuroprotective effect of Brahmi, an ayurvedic drug against oxidative stress induced by methyl mercury toxicity in rat brain mitochondrial-enriched fractions. Nat Prod Res 2014; 29:1046-51. [DOI: 10.1080/14786419.2014.968153] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Thurtle N, Greig J, Cooney L, Amitai Y, Ariti C, Brown MJ, Kosnett MJ, Moussally K, Sani-Gwarzo N, Akpan H, Shanks L, Dargan PI. Description of 3,180 courses of chelation with dimercaptosuccinic acid in children ≤ 5 y with severe lead poisoning in Zamfara, Northern Nigeria: a retrospective analysis of programme data. PLoS Med 2014; 11:e1001739. [PMID: 25291378 PMCID: PMC4188566 DOI: 10.1371/journal.pmed.1001739] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 08/19/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND In 2010, Médecins Sans Frontières (MSF) discovered extensive lead poisoning impacting several thousand children in rural northern Nigeria. An estimated 400 fatalities had occurred over 3 mo. The US Centers for Disease Control and Prevention (CDC) confirmed widespread contamination from lead-rich ore being processed for gold, and environmental management was begun. MSF commenced a medical management programme that included treatment with the oral chelating agent 2,3-dimercaptosuccinic acid (DMSA, succimer). Here we describe and evaluate the changes in venous blood lead level (VBLL) associated with DMSA treatment in the largest cohort of children ≤ 5 y of age with severe paediatric lead intoxication reported to date to our knowledge. METHODS AND FINDINGS In a retrospective analysis of programme data, we describe change in VBLL after DMSA treatment courses in a cohort of 1,156 children ≤ 5 y of age who underwent between one and 15 courses of chelation treatment. Courses of DMSA of 19 or 28 d duration administered to children with VBLL ≥ 45 µg/dl were included. Impact of DMSA was calculated as end-course VBLL as a percentage of pre-course VBLL (ECP). Mixed model regression with nested random effects was used to evaluate the relative associations of covariates with ECP. Of 3,180 treatment courses administered, 36% and 6% of courses commenced with VBLL ≥ 80 µg/dl and ≥ 120 µg/dl, respectively. Overall mean ECP was 74.5% (95% CI 69.7%-79.7%); among 159 inpatient courses, ECP was 47.7% (95% CI 39.7%-57.3%). ECP after 19-d courses (n = 2,262) was lower in older children, first-ever courses, courses with a longer interval since a previous course, courses with more directly observed doses, and courses with higher pre-course VBLLs. Low haemoglobin was associated with higher ECP. Twenty children aged ≤ 5 y who commenced chelation died during the period studied, with lead poisoning a primary factor in six deaths. Monitoring of alanine transaminase (ALT), creatinine, and full blood count revealed moderate ALT elevation in <2.5% of courses. No clinically severe adverse drug effects were observed, and no laboratory findings required discontinuation of treatment. Limitations include that this was a retrospective analysis of clinical data, and unmeasured variables related to environmental exposures could not be accounted for. CONCLUSIONS Oral DMSA was a pharmacodynamically effective chelating agent for the treatment of severe childhood lead poisoning in a resource-limited setting. Re-exposure to lead, despite efforts to remediate the environment, and non-adherence may have influenced the impact of outpatient treatment. Please see later in the article for the Editors' Summary.
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Affiliation(s)
| | - Jane Greig
- Médecins Sans Frontières, London, United Kingdom
| | | | - Yona Amitai
- Department of Management, Bar Ilan University, Ramat Gan, Israel
| | - Cono Ariti
- London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Mary Jean Brown
- Healthy Homes/Lead Poisoning Prevention Program, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Michael J. Kosnett
- Division of Clinical Pharmacology and Toxicology, Department of Medicine, University of Colorado School of Medicine, Denver, Colorado, United States of America
| | | | - Nasir Sani-Gwarzo
- Department of Public Health, Federal Ministry of Health, Abuja, Nigeria
| | - Henry Akpan
- Federal Ministry of Health, Abuja, Nigeria
- Federal Ministry of Communication Technology, Abuja, Nigeria
| | | | - Paul I. Dargan
- Médecins Sans Frontières, Amsterdam, Holland
- Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom
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Smith D, Strupp BJ. The scientific basis for chelation: animal studies and lead chelation. J Med Toxicol 2014; 9:326-38. [PMID: 24113857 DOI: 10.1007/s13181-013-0339-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
This presentation summarizes several of the rodent and non-human studies that we have conducted to help inform the efficacy and clinical utility of succimer (meso-2,3-dimercaptosuccincinic acid) chelation treatment. We address the following questions: (1) What is the extent of body lead, and in particular brain lead reduction with chelation, and do reductions in blood lead accurately reflect reductions in brain lead? (2) Can succimer treatment alleviate the neurobehavioral impacts of lead poisoning? And (3) does succimer treatment, in the absence of lead poisoning, produce neurobehavioral deficits? Results from our studies in juvenile primates show that succimer treatment is effective at accelerating the elimination of lead from the body, but chelation was only marginally better than the complete cessation of lead exposure alone. Studies in lead-exposed adult primates treated with a single 19-day course of succimer showed that chelation did not measurably reduce brain lead levels compared to vehicle-treated controls. A follow-up study in rodents that underwent one or two 21-day courses of succimer treatment showed that chelation significantly reduced brain lead levels, and that two courses of succimer were significantly more efficacious at reducing brain lead levels than one. In both the primate and rodent studies, reductions in blood lead levels were a relatively poor predictor of reductions in brain lead levels. Our studies in rodents demonstrated that it is possible for succimer chelation therapy to alleviate certain types of lead-induced behavioral/cognitive dysfunction, suggesting that if a succimer treatment protocol that produced a substantial reduction of brain lead levels could be identified for humans, a functional benefit might be derived. Finally, we also found that succimer treatment produced lasting adverse neurobehavioral effects when administered to non-lead-exposed rodents, highlighting the potential risks of administering succimer or other metal-chelating agents to children who do not have elevated tissue lead levels. It is of significant concern that this type of therapy has been advocated for treating autism.
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Affiliation(s)
- Donald Smith
- Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, CA, USA,
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XXXIII International Congress of the European Association of Poisons Centres and Clinical Toxicologists (EAPCCT) 28–31 May 2013, Copenhagen, Denmark. Clin Toxicol (Phila) 2013. [DOI: 10.3109/15563650.2013.785188] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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15
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Gumienna-Kontecka E, Nurchi VM, Szebesczyk A, Bilska P, Krzywoszynska K, Kozlowski H. Chelating Agents as Tools for the Treatment of Metal Overload. Z Anorg Allg Chem 2013. [DOI: 10.1002/zaac.201300064] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Nwokocha CR, Owu DU, Nwokocha MI, Ufearo CS, Iwuala MOE. Comparative study on the hepatoprotection to heavy metals of Zingiber officinale. Pharmacognosy Res 2012; 4:208-13. [PMID: 23225964 PMCID: PMC3510873 DOI: 10.4103/0974-8490.102263] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 11/23/2011] [Accepted: 10/11/2012] [Indexed: 01/10/2023] Open
Abstract
Context: Zingiber officinale (Zingiberaceae) is a herb used for culinary and therapeutic purposes due to its anti-inflammatory and antioxidant potentials. Objectives: We examined its protective ability against mercury (Hg), lead (Pb) and cadmium (Cd) accumulation in the liver. Materials & Methods: Ground Zingiber officinale (7%, w/w of feed) was administered to rats either at the same time with the exposure ofheavy metals (group 2), a week after exposure to heavy metals (group 3) or given a week before heavy metal exposure (group 4) for six weeks. Animals were exposed to either of Hg (10 ppm), Cd (200 ppm) and Pb (100 ppm) in drinking water. The heavy metal accumulations in the liver were determined using AAS. Results: Weight losses induced by these metals were not reversed by Zingiber officinale administration. There was a significant (P<0.01) increase in protection to Pb (97%) and Cd (63%) accumulation when compared to Hg (32%) at week 2. The protective ability was significantly (P<0.01) decreased at week 4 when compared to week 2 for Cd and Pb but not to Hg in groups 3 (50%) and 4 (52%). At week 6, hepatoprotection to Hg (44%) and Cd (85%) was significantly (P<0.01) different but not to Pb which was only significant (P<0.05) in week 2 of treatment for all groups. Discussion and Conclusion: Zingiber officinale affected the bioavailability, elimination and uptake of these metals in a time-dependent way with highest beneficial reducing effect to Cd followed by Hg and least protection to Pb in the liver.
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Affiliation(s)
- Chukwuemeka R Nwokocha
- Department of Basic Medical Sciences, University of the West Indies, Mona Campus, Nigeria
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Comparative analysis on the effect of Lycopersicon esculentum (tomato) in reducing cadmium, mercury and lead accumulation in liver. Food Chem Toxicol 2012; 50:2070-3. [DOI: 10.1016/j.fct.2012.03.079] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Revised: 03/27/2012] [Accepted: 03/29/2012] [Indexed: 01/23/2023]
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Comparative study on the efficacy of Allium sativum (garlic) in reducing some heavy metal accumulation in liver of wistar rats. Food Chem Toxicol 2011; 50:222-6. [PMID: 22101063 DOI: 10.1016/j.fct.2011.11.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 10/27/2011] [Accepted: 11/03/2011] [Indexed: 01/08/2023]
Abstract
SCOPE Heavy metals are known to cause damage through indirect oxidative effects. This study was undertaken to compare the therapeutic efficacy and protective ability of garlic extracts on reducing toxicity induced by mercury, lead and cadmium in the liver. METHODS AND RESULTS Rats were fed with rat chow mixed with raw garlic (7% w/w) while mercury (10ppm), cadmium (200ppm) and lead (100ppm) were given in drinking water. Garlic was administered either at the same time with the metals (group 2), a week after exposure to heavy metals (group 3) or a week before heavy metal exposure (group 4) for 6weeks. The heavy metal accumulations in the liver were determined using AAS. The percentage protection showed a time-dependent effect and was significantly (P<0.01) higher for cadmium compared to mercury and lead-treated groups. Analysis between the groups showed that garlic treatment after exposure had a significantly (P<0.05) higher percentage protection when compared with other modes. CONCLUSION These results suggest that garlic offered more hepatoprotective effect to cadmium followed by mercury and least protection to lead at the selected dose of each metal in this study through the processes of uptake, assimilation and elimination of these metals.
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Nwokocha CR, Owu DU, Ufearo CS, Iwuala MOE. Comparative study on the efficacy of Garcinia kola in reducing some heavy metal accumulation in liver of Wistar rats. JOURNAL OF ETHNOPHARMACOLOGY 2011; 135:488-491. [PMID: 21458555 DOI: 10.1016/j.jep.2011.03.049] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 03/14/2011] [Accepted: 03/23/2011] [Indexed: 05/30/2023]
Abstract
Garcinia kola is regarded as an antidote and anti-hepatotoxic agent. We examined its protection ability against mercury (Hg), lead (Pb) and cadmium (Cd) accumulation in the liver. The ground seed was mixed with rat feed (5%, w/w) and fed to rats while Hg (10 ppm), Cd (200 ppm) and Pb (100 ppm) was given in drinking water. Garcinia kola was administered either at the same time with the metals (group 2), a week after exposure to heavy metals (group 3) or given a week before heavy metal exposure (group 4) for six weeks. The heavy metal accumulations in the liver were determined using AAS. Garcinia kola could not reverse the weight reduction in the heavy metal exposed groups although it offers more protection and aid greater elimination of heavy metals from the liver. There was a significant (P<0.01) increase in protection by Garcinia kola to Cd (72.4%) and Pb (56.2%) accumulation when compared to Hg (40%) at week 2 which was significantly (P<0.01) decreased at week 4 when compared to week 2. At week 6, the percentage protection to both Hg (64.2%) and Cd (62.2%) were comparable to each other while protection to Pb (49.9%) accumulation was significantly (P<0.01) reduced. The percentage protection was time-dependent in some groups but treatment during and after the exposure provided a greater protection. Garcinia kola has the highest hepatoprotective effect to Cd followed by Hg and least protection against Pb toxicity in rats and its administration is beneficial in reducing heavy metal accumulation in the liver.
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Affiliation(s)
- C R Nwokocha
- Department of Basic Medical Sciences, University of the West Indies, Mona Campus, Kingston 7, Jamaica.
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Youngster I, Arcavi L, Schechmaster R, Akayzen Y, Popliski H, Shimonov J, Beig S, Berkovitch M. Medications and glucose-6-phosphate dehydrogenase deficiency: an evidence-based review. Drug Saf 2010; 33:713-26. [PMID: 20701405 DOI: 10.2165/11536520-000000000-00000] [Citation(s) in RCA: 149] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzyme defect and one of the most common genetic disorders worldwide, with an estimated 400 million people worldwide carrying a mutation in the G6PD gene that causes deficiency of the enzyme. Although drug-induced haemolysis is considered the most common adverse clinical consequence of G6PD deficiency, significant confusion exists regarding which drugs can cause haemolytic anaemia in patients with G6PD deficiency. In the absence of consensus among physicians, patients are subject to conflicting advice, causing uncertainty and distress. In the current review we aimed, by thorough search of the medical literature, to collect evidence on which to base decisions either to prohibit or allow the use of various medications in patients with G6PD deficiency. A literature search was conducted during May 2009 for studies and case reports on medication use and G6PD deficiency using the following sources: MEDLINE (1966-May 2009), PubMed (1950-May 2009), the Cochrane database of systematic reviews (2009), and major pharmacology, internal medicine, haematology and paediatric textbooks. After assessing the literature, we divided medications into one of three groups: medications that should be avoided in individuals with G6PD deficiency, medications that were considered unsafe by at least one source, but according to our review can probably be given safely in normal therapeutic dosages to individuals with G6PD deficiency as evidence does not contravene their use, and medications where no evidence at all was found to contravene their use in G6PD-deficient patients. It is reasonable to conclude that, over time, many compounds have been wrongly cited as causing haemolysis because they were administered to patients experiencing an infection-related haemolytic episode. We found solid evidence to prohibit only seven currently used medications: dapsone, methylthioninium chloride (methylene blue), nitrofurantoin, phenazopyridine, primaquine, rasburicase and tolonium chloride (toluidine blue). Regarding all other medications, our review found no evidence to contravene their use in normal therapeutic doses to G6PD-deficient patients. There is a need for evidence-based global consensus regarding medication use in G6PD-deficient patients.
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Affiliation(s)
- Ilan Youngster
- Clinical Pharmacology Unit, Assaf Harofeh Medical Center, Zerifin, Israel.
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Abstract
We report a case of total hyperpigmentation of the skin, severe itching, muscle weakness and thrombocytosis. Laboratory investigation showed white blood cell (WBC) 8.2 x 10(6)/L, Hb 125 g/L, platelets 1221 x 10(6)/L and urinary lead after DMSA mobilization test 2684 mcg/g creatinine (normal <5). Chelation therapy with DMSA resulted in complete recovery of the hyperpigmentation, itching and thrombocytosis. Lead poisoning should be considered in the differential diagnosis of obscured thrombocytosis.
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Affiliation(s)
- Abdulkareem Al Momen
- Division of Hematology-Oncology, Department of Medicine, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia.
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Bradberry S, Vale A. A comparison of sodium calcium edetate (edetate calcium disodium) and succimer (DMSA) in the treatment of inorganic lead poisoning. Clin Toxicol (Phila) 2009; 47:841-58. [DOI: 10.3109/15563650903321064] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Bradberry S, Sheehan T, Vale A. Use of oral dimercaptosuccinic acid (succimer) in adult patients with inorganic lead poisoning. QJM 2009; 102:721-32. [PMID: 19700440 DOI: 10.1093/qjmed/hcp114] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Chelation therapy has been used as a means of reducing the body burden of lead for five decades. Intravenous sodium calcium edetate has been the preferred agent, but there is increasing evidence that dimercaptosuccinic acid (DMSA) is also a potent chelator of lead. METHODS Oral DMSA 30 mg/kg/day was administered to adults with blood lead concentrations > or = 50 microg/dl. The impact of DMSA on urine lead excretion, on blood lead concentrations and on symptoms was observed. The incidence and severity of adverse effects was also recorded. RESULTS Thirty-five courses were given to 17 patients. DMSA significantly (P < 0.0001) increased urine lead excretion and significantly (P < 0.0001) reduced blood lead concentrations. Mean daily urine lead excretion exceeded the pre-treatment value by a median of 12-fold with wide variation in response (IQR 8.9-14.8, 95% CI 10.1-14.6). Pre-treatment blood lead concentrations correlated well with 5-day urine lead excretion. Headache, lethargy and constipation improved or resolved in over half the patients within the first 2 days of chelation. DMSA was generally well tolerated, but one course was discontinued due to a severe mucocutaneous reaction. There was a transient increase in alanine aminotransferase (ALT) activity during 14% of chelations. DMSA caused a significant increase in urine copper (P < 0.0001) and zinc (P < 0.05) excretion. CONCLUSION Oral DMSA 30 mg/kg/day is an effective antidote for lead poisoning, though there is a wide inter- and intra-individual variation in response.
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Affiliation(s)
- S Bradberry
- West Midland Portion Unit, City Hospital, University of Birmingham, Birmingham, B18 7QH, UK
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Bradberry S, Vale A. Dimercaptosuccinic acid (succimer; DMSA) in inorganic lead poisoning. Clin Toxicol (Phila) 2009; 47:617-31. [DOI: 10.1080/15563650903174828] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Moore CF, Gajewski LL, Laughlin NK, Luck ML, Larson JA, Schneider ML. Developmental lead exposure induces tactile defensiveness in rhesus monkeys (Macaca mulatta). ENVIRONMENTAL HEALTH PERSPECTIVES 2008; 116:1322-1326. [PMID: 18941572 PMCID: PMC2569089 DOI: 10.1289/ehp.11203] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Accepted: 05/30/2008] [Indexed: 05/26/2023]
Abstract
BACKGROUND Tactile defensiveness in children is associated with difficult social relations, emotional dysregulation, and inattention. However, there are no studies of lead exposure and tactile defensiveness in children or animals in spite of the fact that lead exposure is also associated with inattention and emotional dysregulation. OBJECTIVES In this study we tested whether lead exposure induces tactile defensiveness in rhesus monkeys. METHODS We tested 61 monkeys from a 3 (no lead, 1-year lead, 2-year lead) x 2 (succimer chelation or not) factorial experiment for tactile defensiveness at 4 years of age. Lead-treated monkeys had been orally administered lead in a daily milk solution from 8 days of life to either 1 or 2 years of age to produce blood lead levels of 35-40 mg/dL. Succimer chelation therapy or placebo was administered at 1 year of age. We measured tactile defensiveness using six repeated trials of each of three textures as a swipe to the cheek and neck. RESULTS Lead-exposed monkeys showed higher negative responses to repeated tactile stimulation compared with controls. Blood lead during the first 3 months of life was positively correlated with the negative response on the tactile defensiveness test. There was an interaction of lead exposure x succimer chelation x trials, but it is not clear that succimer chelation was beneficial with respect to tactile defensiveness. CONCLUSIONS This is the first report to implicate lead as a potential cause of tactile defensiveness. Research should examine whether lead exposure is associated with tactile defensiveness in children.
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Affiliation(s)
| | - Lisa L. Gajewski
- Harlow Center for Biological Psychology
- Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Nellie K. Laughlin
- Harlow Center for Biological Psychology
- Psychology Department, Marquette University, Milwaukee, Wisconsin, USA
| | | | - Julie A. Larson
- Harlow Center for Biological Psychology
- Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Mary L. Schneider
- Department of Psychology
- Harlow Center for Biological Psychology
- Department of Kinesiology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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Rauh VA, Landrigan PJ, Claudio L. Housing and health: intersection of poverty and environmental exposures. Ann N Y Acad Sci 2008; 1136:276-88. [PMID: 18579887 DOI: 10.1196/annals.1425.032] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The importance of adequate housing for the maintenance of health and well-being has long been a topic of scientific and public health policy discussion, but the links remain elusive. Here we explore the role of the residential environment in the etiology of illness (specifically asthma) and the persistence of socioeconomic health disparities. Housing conditions, shaped by social forces, affect exposure to physical and chemical "toxicants," thereby translating social adversities into individual illness and population health disparities. We discuss the mediating role of housing in determining health outcomes at multiple levels (social-structural, neighborhood, and individual family). To date, little attention has been paid by most environmental health scientists to the social-structural conditions underlying gross inequities in the distribution of toxic exposures, with even less attention to the processes whereby these social conditions may directly affect susceptibility to the toxic exposures themselves. This chapter goes beyond traditional medical and environmental science models to incorporate a range of social and physical determinants of environmental pollutions, illustrating how these conditions result in health and illness. We focus here on childhood asthma as an example of a serious public health problem that has been associated with low income, minority status, and characteristics of the home environment. We end the chapter with a discussion of the environmental justice movement and the role of housing as a potential agent of change and focus of interventions aimed to reduce the harmful effects of environmental pollutants.
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Affiliation(s)
- Virginia A Rauh
- Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, 60 Haven Ave., B-2, New York, NY 10032, USA.
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Abstract
Childhood lead poisoning is still an enormous public health issue in the United States, affecting thousands of children and their families. New evidence suggests that even very low blood lead levels, less than 10 microg/dL, can be associated with neurologic injury. This article discusses characteristics of children at high risk for lead poisoning, unusual sources of lead contamination, and new aspects of lead's pathophysiology. It includes current thinking on the clinical management and prevention of childhood lead poisoning.
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Affiliation(s)
- Alan D Woolf
- Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA.
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Beaudin SA, Stangle DE, Smith DR, Levitsky DA, Strupp BJ. Succimer chelation normalizes reactivity to reward omission and errors in lead-exposed rats. Neurotoxicol Teratol 2007; 29:188-202. [PMID: 17196787 DOI: 10.1016/j.ntt.2006.11.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2006] [Revised: 10/08/2006] [Accepted: 11/12/2006] [Indexed: 11/23/2022]
Abstract
This study evaluated the efficacy of a 3-week course of succimer treatment to alleviate behavioral deficits in rats exposed to lead (Pb) for the first 4 weeks of life. A 3 x 2 factorial design was used: three levels of lead exposure (No Pb, Moderate, and High Pb) and two levels of chelation (succimer or vehicle). Behavioral testing was conducted following chelation therapy, from 2 to 9 months of age; this report presents the results of two of the administered tasks: (1) a conditional olfactory discrimination task (baseline task), and (2) a conditional olfactory discrimination task with periodic reward omission on some correct trials (RO task). In the RO task, the performance disruption produced by committing an error on the previous trial was significantly greater for both unchelated lead-exposed groups than for controls. The High Pb rats were also more sensitive to reward omission than controls, providing converging evidence for impaired regulation of arousal or emotion. Importantly, succimer treatment was effective in normalizing the heightened reactivity of the lead-exposed animals to both errors and reward omission. In addition, non-lead-exposed rats that were treated with succimer tended to be more affected by a prior error than controls in their latency to respond on post-error trials. In sum, these findings provide new evidence that succimer chelation can significantly lessen the lasting neurobehavioral dysfunction produced by early lead exposure, but also suggest that there may be risks of administering the drug to individuals without elevated blood lead levels.
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Affiliation(s)
- Stéphane A Beaudin
- Division of Nutritional Sciences, Cornell University, Savage Hall, Ithaca, NY 14853, USA
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29
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Powell ST, Bolisetty S, Wheaton GR. Succimer therapy for congenital lead poisoning from maternal petrol sniffing. Med J Aust 2006; 184:84-5. [PMID: 16411875 DOI: 10.5694/j.1326-5377.2006.tb00125.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Accepted: 10/24/2005] [Indexed: 11/17/2022]
Abstract
An infant, born at 35 weeks' gestation to a woman who sniffed petrol, had a cord blood lead level eight times the accepted limit. Treatment with oral dimercaptosuccinic acid promptly reduced his blood lead levels. To our knowledge, this is the first reported case of congenital lead poisoning secondary to maternal petrol sniffing. We suggest that at-risk pregnancies should be identified, cord blood lead levels tested, and chelation therapy and developmental follow-up offered to affected infants.
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Affiliation(s)
- Suzanna T Powell
- Paediatrics, Tamworth Base Hospital, PO Box 640, Tamworth, NSW 2340, Australia.
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Sivaprasad TR, Malarkodi SP, Varalakshmi P. Therapeutic efficacy of lipoic acid in combination with dimercaptosuccinic acid against lead-induced renal tubular defects and on isolated brush-border enzyme activities. Chem Biol Interact 2004; 147:259-71. [PMID: 15135082 DOI: 10.1016/j.cbi.2004.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2004] [Indexed: 11/30/2022]
Abstract
The combined therapeutic potentials of lipoic acid and dimercaptosuccinic acid were compared against their sole administrations in restoring the altered lead sensitive indices in urine and isolated renal brush-border preparations. Toxicity was induced in male albino rats (Wistar strain) by administering lead acetate (0.2%) in drinking water for 5 weeks, followed by therapy comprising lipoic acid (25 mg/kg body weight) and dimercaptosuccinic acid (20 mg/kg body weight) solely as well as combined during the 6th week. Changes in kidney weights encountered upon lead administration improved after therapy with lipoic acid and dimercaptosuccinic acid. Renal integrity was assessed by measuring the activities of alkaline phosphatase, acid phosphatase, lactate dehydrogenase, leucine aminopeptidase, N-acetyl-beta-D-glucosaminidase, gamma-glutamyl transferase and beta-glucuronidase in urine along with some urinary constituents (urea, uric acid, creatinine, protein and phosphorous). The effects of lead were also studied on isolated brush-border enzymes (alkaline phosphatase, acid phosphatase, gamma-glutamyl transferase and beta-glucuronidase) that showed a decline upon its administration. Increased activities of urinary enzymes were accompanied by increase in the urinary constituents. Increase in renal lead content was paralleled by a drastic fall in the renal delta-aminolevulinic acid dehydratase and a rise in urinary lead levels. Relative to the administration of lead, the combined therapy showed betterment on the renal integrity with respect to the functional parameters assessed, thereby indicating its efficacy over the monotherapies.
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Meldrum JB, Ko KW. Effects of calcium disodium EDTA and meso-2,3-dimercaptosuccinic acid on tissue concentrations of lead for use in treatment of calves with experimentally induced lead toxicosis. Am J Vet Res 2003; 64:672-6. [PMID: 12828250 DOI: 10.2460/ajvr.2003.64.672] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare the efficacy of calcium disodium EDTA (CaNa2EDTA) and meso-2,3-dimercaptosuccinic acid (DMSA) in reducing concentrations of lead in selected tissues for use in treatment of calves with experimentally induced lead toxicosis. ANIMALS 19 sexually intact male Holstein calves that weighed 35 to 60 kg. PROCEDURE Calves were randomly assigned to 1 of 5 treatment groups: group 1, control calves; group 2, lead only; group 3, lead and EDTA; group 4, lead and DMSA; and group 5, lead, EDTA, and DMSA. Calves in groups 2 to 5 were dosed daily with lead (5 mg/kg, PO) for 10 days. Doses of EDTA (100 mg/kg) and DMSA (25 mg/kg) were administered IV once daily for 4 consecutive days beginning on day 11. Effects of the chelators on lead concentrations in the liver, kidneys, testes, muscles, bones, and brain were compared among the various groups. RESULTS Compared with the effects of EDTA, DMSA greatly reduced lead concentrations in renal and hepatic tissues. We did not detect significant differences for the effects of EDTA or DMSA on lead concentrations in the testes; there was an adverse interaction of EDTA with DMSA that caused an increase in lead concentrations in the testes. CONCLUSIONS AND CLINICAL RELEVANCE DMSA is much more effective than EDTA in removing lead from renal and hepatic tissues in calves. Use of DMSA in calves with lead intoxication appears to be a viable treatment option. Combining DMSA and EDTA as a treatment modality in calves did not offer any advantages.
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Affiliation(s)
- James B Meldrum
- Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061, USA
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Queiroz MLS, Rodrigues APO, Bincoletto C, Figueirêdo CAV, Malacrida S. Protective effects of Chlorella vulgaris in lead-exposed mice infected with Listeria monocytogenes. Int Immunopharmacol 2003; 3:889-900. [PMID: 12781705 DOI: 10.1016/s1567-5769(03)00082-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chlorella vulgaris extract (CVE) was examined for its chelating effects on the myelosuppression induced by lead in Listeria monocytogenes-infected mice. The reduction in the number of bone marrow granulocyte-macrophage progenitors (CFU-GM) observed after the infection was more severe in the groups previously exposed to lead. Extramedullar hematopoiesis, which was drastically increased after the infection, was not altered by the presence of lead. Treatment with CVE, given simultaneously or following lead exposure, restored to control values the myelosuppression observed in infected/lead-exposed mice and produced a significant increase in serum colony-stimulating activity. The benefits of the CVE treatment were also evident in the recovery of thymus weight, since the reduction produced by the infection was further potentiated by lead exposure. The efficacy of CVE was evident when infected and infected/lead-exposed mice were challenged with a lethal dose of L. monocytogenes after a 10-day treatment with 50 mg/kg CVE/day, given simultaneously to the exposure to 1300 ppm lead acetate in drinking water. Survival rates of 30% for the infected group and of 20% for the infected/lead-exposed groups were observed. Evidence that these protective effects of CVE are partly due to its chelating effect was given by the changes observed in blood lead levels. We have observed in the group receiving the CVE/lead simultaneous exposure a dramatic reduction of 66.03% in blood lead levels, when compared to lead-exposed nontreated control. On the other hand, CVE treatment following lead exposure produced a much less effective chelating effect. CVE treatments for 3 or 10 days, starting 24 h following lead exposure, produced a reduction in blood lead levels of 13.5% and 17%, respectively, compared to lead-exposed nontreated controls. The significantly better response observed with the simultaneous CVE/lead administration indicates that the immunomodulation effect of CVE plays an important role in the ability of this algae to reduce blood lead levels. In this regard, additional experiments with gene knockout C57BL/6 mice lacking a functional IFN-gamma gene demonstrated that this cytokine is of paramount importance in the protection afforded by CVE. The antibacterial evaluation measured by the rate of survival demonstrated that, in face of a 100% survival in the control group composed of normal C57BL/6 mice, which are resistant to L. monocytogenes, we observed no protection whatsoever in the IFN-gamma knockout C57BL/6 mice treated with CVE and inoculated with L. monocytogenes.
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Affiliation(s)
- Mary L S Queiroz
- Departamento de Farmacologia/Hemocentro, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), C.P. 6111, CEP 13083-970, SP, Campinas, Brazil.
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Rusyniak DE, Kao LW, Nanagas KA, Kirk MA, Furbee RB, Brizendine EJ, Wilmot PE. Dimercaptosuccinic acid and Prussian Blue in the treatment of acute thallium poisoning in rats. JOURNAL OF TOXICOLOGY. CLINICAL TOXICOLOGY 2003; 41:137-42. [PMID: 12733851 DOI: 10.1081/clt-120019129] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
INTRODUCTION Despite being banned as a pesticide, thallium still results in human and animal poisonings. Current recommended treatments include the use of the chemical Prussian Blue. Limitations in its availability may result in Prussian Blue not being obtainable in the thallium-poisoned patient. The chelator 2,3-Dimercaptosuccinic acid (DMSA) is currently FDA-approved for use in childhood lead poisoning and has been reported to be beneficial in treating other heavy metal poisonings. The objective of this study was to determine the efficacy of DMSA as a treatment for thallium poisoning by studying mortality and whole-brain concentrations in thallium poisoned rats. MATERIAL AND METHODS Rats were gavaged with 30 mg/kg of thallium. After 24 hours they were randomized to DMSA (n = 20) 50 mg/kg twice daily for 5 days, Prussian Blue (n = 20) 50 mg/kg twice daily for 5 days, or control (n = 30). Animals were monitored twice daily for weight loss and mortality. Animals losing greater than 20% of their starting weight were euthanized and counted as a mortality. All surviving rats at 120 hours had their brains harvested and digested and underwent subsequent thallium analysis. RESULTS The rate of survival in DMSA-treated animals compared to control was 45% vs. 21%, p = 0.07. Mean whole-brain thallium concentrations between DMSA and control rats were 3.4 vs. 3.0 microg/g, p = 0.06. Prussian Blue-treated rats had significantly improved survival (70% vs. 21%, p < 0.01) and lower whole-brain thallium concentrations (1.6 vs. 3.0 microg/g, p < 0.01 tissue) compared to controls. CONCLUSION DMSA failed to reduce brain thallium concentrations in rats poisoned with thallium and had an indeterminate effect on mortality while Prussian Blue significantly reduces both brain thallium concentrations and mortality.
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Affiliation(s)
- Daniel E Rusyniak
- Department of Emergency Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA.
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Tait PA, Vora A, James S, Fitzgerald DJ, Pester BA. Severe congenital lead poisoning in a preterm infant due to a herbal remedy. Med J Aust 2002; 177:193-5. [PMID: 12175323 DOI: 10.5694/j.1326-5377.2002.tb04731.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2002] [Accepted: 06/07/2002] [Indexed: 11/17/2022]
Abstract
A preterm infant born to a woman with chronic lead poisoning was found to have the highest blood lead level recorded for a surviving neonate. Parenteral calcium disodium edetate, but not oral succimer, was effective in reducing the infant's lead burden in the neonatal period. An exposure assessment revealed the mother's long-term ingestion of lead-contaminated herbal tablets as the source.
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Affiliation(s)
- Paul A Tait
- Pharmacy Department, Women's and Children's Hospital, North Adelaide, SA
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Clifton JC, Sigg T, Burda AM, Leikin JB, Smith CJ, Sandler RH. Acute pediatric lead poisoning: combined whole bowel irrigation, succimer therapy, and endoscopic removal of ingested lead pellets. Pediatr Emerg Care 2002; 18:200-2. [PMID: 12066009 DOI: 10.1097/00006565-200206000-00013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Jack C Clifton
- Department of Pediatric Emergency Medicine, Rush Children's Hospital, Chicago, Illinois, USA.
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Abstract
Early clinical features of lead toxicity are non-specific and an occupational history is particularly valuable. Lead in the body comprises 2% in the blood (t1/2 35 days) and 95% in bone and dentine (t1/2 20-30 years). Blood lead may remain elevated for years after cessation from long exposure, due to redistribution from bone. Blood lead concentration is the most widely used marker for inorganic lead exposure. Zinc protoporphyrin (ZPP) concentration in blood usefully reflects lead exposure over the prior 3 months. Symptomatic patients with blood lead concentration >2.4 micromol l-1 (50 microg dl-1) or in any event >3.8 micromol l-1 (80 microg dl-1) should receive sodium calciumedetate i.v., followed by succimer by mouth for 19 days. Asymptomatic patients with blood lead concentration >2.4 micromol l-1 (50 microg dl-1) may be treated with succimer alone. Sodium calciumedetate should be given with dimercaprol to treat lead encephalopathy.
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Affiliation(s)
- J N Gordon
- Medicine and Laboratory Services, Royal United Hospital, Combe Park, Bath BA1 3NG, UK
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37
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Shannon M. Lead poisoning treatment--a continuing need (commentary). JOURNAL OF TOXICOLOGY. CLINICAL TOXICOLOGY 2002; 39:661-3. [PMID: 11778663 DOI: 10.1081/clt-100108506] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- M Shannon
- Regional Center for Poison Control and Prevention Serving Massachusetts and Rhode Island, Boston, Massachusetts, USA
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38
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Rademacher DJ, Steinpreis RE, Weber DN. Short-term exposure to dietary Pb and/or DMSA affects dopamine and dopamine metabolite levels in the medulla, optic tectum, and cerebellum of rainbow trout (Oncorhynchus mykiss). Pharmacol Biochem Behav 2001; 70:199-207. [PMID: 11701189 DOI: 10.1016/s0091-3057(01)00597-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Rainbow trout (Oncorhynchus mykiss) were randomly assigned to one of the following dietary exposure conditions: lead (Pb) solvent (2% nitric acid), meso-2,3-dimercaptosuccinic acid (DMSA) solvent (0.1 N NaOH), Pb, DMSA, Pb followed by Pb solvent, or Pb followed by DMSA. Medulla, cerebellum, and optic tectum homogenates were analyzed for dopamine (DA), homovanillic acid (HVA), and 3,4-dihydroxyphenylacetic acid (DOPAC). DA levels in all brain regions tended to be highest for trout exposed to dietary Pb followed by dietary DMSA. DA levels were elevated for trout exposed to dietary DMSA and Pb followed by Pb solvent. DA levels were below control levels for trout exposed to Pb only. HVA levels varied across brain regions. However, HVA levels in all brain regions tended to be elevated for trout exposed to dietary DMSA and Pb followed by Pb solvent. DOPAC levels across all brain regions were below control levels for trout dietary exposed to DMSA, Pb only, Pb followed by Pb solvent, and Pb followed by DMSA. These data indicate that Pb and/or DMSA have the potential of altering DA, HVA, and DOPAC levels in the medulla, cerebellum, and optic tectum. The animal model of short-term dietary exposure to Pb and DMSA, both alone and sequentially, to mimic dietary exposure to Pb and the oral delivery of DMSA, that our laboratory has developed, may be useful in future studies aimed at characterizing the neurobiological mechanisms by which Pb and/or DMSA alter neurotransmitter levels and behavior.
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Affiliation(s)
- D J Rademacher
- Department of Psychology, University of Wisconsin-Milwaukee, 224 Garland Hall, 2441 East Hartford Avenue, Milwaukee, WI 53211, USA
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39
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Nogueira CW, Soares FA, Bolzan RC, Jacques-Silva MC, Souza DO, Rocha JB. Investigations into the mechanism of 2,3-dimercaptopropanol neurotoxicity. Neurochem Res 2000; 25:1553-8. [PMID: 11152384 DOI: 10.1023/a:1026658217907] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
2,3 dimercaptopropanol (BAL), is a dithiol chelating agent, used for the treatment of heavy metal intoxication; however, this compound has low therapeutic efficacy and in some situations may cause neurotoxic effects. In experimental models, administration of high doses of BAL produces seizures that culminate in animal death. However, investigations on the modulation of neurotransmitter system(s) involved in BAL-induced seizures are still lacking in the literature. In the present study, the neurotoxicity of BAL, as measured by the manifestation of seizures was examined and the modulation of glutamatergic and GABAergic receptors and ion channels potentially involved in BAL-induced seizures was investigated. The results demonstrated that BAL (18.6 mg/kg) induced seizures and all mice died within one day. GABAergic allosteric modulators (3 or 12 mg/kg diazepam and 50 mg/kg phenobarbital) blocked the appearance of seizure and reduced almost completely the death caused by BAL. Carbamazepine (5 mg/kg) significantly reduced the incidence of BAL-induced seizures, while sodium valproate and MK-801 were not effective in reducing the incidence of seizures. Valproate (300 mg/kg) and MK-801(0.5 mg/kg) prolonged the latencies for onset of seizures; however, all animals died within one day after BAL administration. High doses of ZnCl2 (135 mg/kg) blocked the appearance of seizures episodes, but no animal survived more than one day. The content of total non-protein -SH in brain of mice treated with 18.6 and 124 mg/kg BAL increased from 0.9+/-0.3 nmol/g (control animals) to 1.7+/-0.3 and 3.5+/-0.8 nmol/g, respectively. In vitro, 0.1-1 mM concentrations of BAL inhibited [3H]glutamate and [3H]MK-801 binding, but increased the binding of [3H]muscimol to brain synaptic plasma membrane. The results reported here demonstrate that GABAergic allosteric modulators (diazepam and phenobarbital) and carbamazepine, a compound that acts by prolonging the recovery of voltage-activated ion channels from inactivation, are able to abolish BAL-induced seizures, while the NMDA antagonist (MK-801) prolonged the latencies for onset of seizures suggesting that modulators of this subtype of glutamate receptor have a modest role on BAL-induced seizures. The results of the present study suggest that allosteric modulators of GABAergic system and carbamazepine, a voltage-gated Na+-channel antagonist, should be considered for the treatment of animals or patients intoxicated with BAL.
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Affiliation(s)
- C W Nogueira
- Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, RS, Brasil.
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40
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Abstract
Recent studies have shown that lead causes oxidative stress by inducing the generation of reactive oxygen species, reducing the antioxidant defense system of cells via depleting glutathione, inhibiting sulfhydryl-dependent enzymes, interfering with some essential metals needed for antioxidant enzyme activities, and/or increasing susceptibility of cells to oxidative attack by altering the membrane integrity and fatty acid composition. Consequently, it is plausible that impaired oxidant/antioxidant balance can be partially responsible for the toxic effects of lead. Where enhanced oxidative stress contributes to lead-induced toxicity, restoration of a cell's antioxidant capacity appears to provide a partial remedy. Several studies are underway to determine the effect of antioxidant supplementation following lead exposure. Data suggest that antioxidants may play an important role in abating some hazards of lead. To explain the importance of using antioxidants in treating lead poisoning the following topics are addressed: (i) Oxidative damage caused by lead poisoning; (ii) conventional treatment of lead poisoning and its side effects; and (iii) possible protective effects of antioxidants in lead toxicity.
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Affiliation(s)
- H Gurer
- Department Of Toxicology, Faculty of Pharmacy, University of Hacettepe, Ankara, Turkey
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41
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Smith DR, Woolard D, Luck ML, Laughlin NK. Succimer and the reduction of tissue lead in juvenile monkeys. Toxicol Appl Pharmacol 2000; 166:230-40. [PMID: 10906287 DOI: 10.1006/taap.2000.8973] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The extent to which succimer (2,3-dimercaptosuccinic acid, DMSA) chelation reduces target organ lead (Pb) levels, including the skeleton, relative to the cessation of Pb exposure is a primary consideration in evaluating its efficacy for reducing toxicity in children. Here, we utilized a rhesus monkey model of childhood Pb exposure and a sensitive stable (204)Pb isotope tracer methodology to determine the efficacy of succimer for reducing Pb in blood, liver, and skeletal tissues from chronic (>/=1 year) versus short-term (3-4 days) Pb exposures. Specific attention was paid to the efficacy of succimer treatment compared to the cessation of Pb exposure. Infant rhesus monkeys (n = 48) were exposed to Pb daily for 1 year or >1 year postpartum to reach and maintain a target blood Pb level of 35-40 microg/dL. Two successive 19-day succimer treatment regimens were administered at 53 and 65 weeks of age (30 mg/kg/day x 5 days followed by 20 mg/kg/day x 14 days). Blood was collected over the course of treatment, and liver and bone biopsy samples were collected on days 0, 5, and 20, relative to the start of treatment (day 0). Complete 24-h urine collections were conducted over the course of treatment. Results of the first chelation indicate that a single regimen of succimer treatment led to significant reductions in blood and liver Pb levels, relative to the placebo group. However, the cessation of Pb exposure alone (i.e., placebo) also led to significant reductions in blood and liver compared to pretreatment levels. Neither succimer nor the cessation of Pb exposure had a significant impact on bone lead levels. Blood Pb levels in the succimer-treated group rebounded within 5 days after treatment ended, becoming comparable with levels in the placebo group from that point on. Results from the second chelation indicate that succimer treatment is essentially equally efficacious in reducing blood Pb at moderate (20 microg/dL) levels where exposures ended >3 months previously and more elevated (40-50 microg/dL) levels where exposures ended just prior to treatment, relative to the placebo treatment. Finally, similar overall outcomes were observed for tissue Pb from recent exposures (i.e., (204)Pb tracer levels), indicating little or no apparent difference in the chelation of Pb from recent (3-4 days) versus long-term exposures. These data demonstrate that succimer does not reduce skeletal Pb levels, and they show that the efficacy of succimer for reducing blood Pb levels does not persist beyond the completion of treatment due to posttreatment rebounds in blood Pb from endogenous sources. They also demonstrate the relative benefit of eliminating Pb exposures, which serves to underscore the importance of primary prevention of Pb exposure. The extent to which these data reflect the efficacy of succimer for reducing neurocognitive impairment is not yet known, although those data are forthcoming.
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Affiliation(s)
- D R Smith
- Environmental Toxicology, University of California, Santa Cruz, California 95064, USA.
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42
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Lifshitz M, Levy J. Efficacy of d-Penicillamine in Reducing Lead Concentrations in Children: A Prospective, Uncontrolled Study. J Pharm Technol 2000. [DOI: 10.1177/875512250001600306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Objective: To evaluate the efficacy of oral d-penicillamine therapy in children with high blood lead concentrations. Design: A prospective, uncontrolled study. Methods and Patients: Seven children (2–16 y old; mean 8.7) with elevated blood lead concentrations but no symptoms of lead poisoning were treated with oral d-penicillamine. Lead-contaminated homemade flour as found to be the source of poisoning. Mean ± SD blood lead concentrations prior to therapy were 60.3 ± 12.9 μg/dL (range 47.8–83). Mean blood zinc protoporphyrin (ZPP) was 337.86 ± 58.55 μmol/mol hemoglobin (Hb) (range 247–394). Results: Ninety days of treatment with d-penicillamine lowered the mean blood lead concentration by 31.7% to a mean of 40.7 ± 8.6 μg/dL (range 30–53) and lowered mean ZPP blood concentrations by 40% to a mean of 201.14 ± 14 μmol/mol Hb (range 150–278). Three patients with blood lead concentrations >45 μg/mL at the end of this therapy were subsequently treated with succimer, an alternative oral chelator; the blood lead concentrations were further reduced to <45 μg/mL. Conclusions: d-Penicillamine therapy significantly reduced blood lead concentrations but did not achieve acceptable lead and ZPP concentrations for young children. Therefore, we conclude that 90 days of d-penicillamine treatment is of limited effectiveness in young children who have high blood lead concentrations and also show symptoms of lead poisoning.
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Merkord J, Weber H, Kröning G, Hennighausen G. Antidotal effects of 2,3-dimercaptopropane-1-sulfonic acid (DMPS) and meso-2,3-dimercaptosuccinic acid (DMSA) on the organotoxicity of dibutyltin dichloride (DBTC) in rats. Hum Exp Toxicol 2000; 19:132-7. [PMID: 10773844 DOI: 10.1191/096032700678815701] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
1. Dialkyltin compounds have been widely used in industry and agriculture, mainly as biocides, catalysts and plast stabilizer. In dependence on the length of the alkyl chains these organotins exert toxic effects on the immune system, the bile duct, liver and pancreas. It has been supposed that similar to organoarsenic the toxicity of the dialkyltin compounds is related to reactions with biological dithiol groups. Therefore, in the present study, the antidotal effects of 2,3-dimercapto-propane-1-sulfonic acid (DMPS) and meso-2,3-dimercaptosuccinic acid (DMSA) on the organotoxic effects of dibutyltin dichloride (DBTC, single administration of 27 micromol kg(-1) b.w. i.v.) in rats were studied using different doses (100 and 500 micromol kg(-1) b.w.) and routes of administration (i.p. and p.o.) of both chelators. Several parameters of organotoxicity (thymus weight and cellularity, bile duct diameter, histological lesions of pancreas and liver, activities of amylase, lipase and alkaline phosphatase, bilirubin and hyaluronic acid in serum) were measured from 6 h to 8 weeks. 2. DMPS and DMSA diminished the DBTC induced bile duct, pancreas and liver lesions stronger than the thymus atrophy. Moreover, the development of a fibrosis of the pancreas and a cirrhosis of liver several weeks after single administration of DBTC to rats was inhibited by DMPS and DMSA. The antidotal effects on serum parameter were observed after both administration routes of the chelators. DMPS was more effective than DMSA in most measured parameters. The decrease in the biliary excretion of organotin by DMPS and DMSA seems to be the reason for the pronounced protective effects of DMPS and DMSA on bile duct, pancreas and liver. 3. For the treatment of poisonings with dibutyltin compounds, the administration of DMPS or DMSA can be recommended.
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Affiliation(s)
- J Merkord
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Rostock, Germany
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44
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Shannon MW, Townsend MK. Adverse effects of reduced-dose d-penicillamine in children with mild-to-moderate lead poisoning. Ann Pharmacother 2000; 34:15-8. [PMID: 10669180 DOI: 10.1345/aph.19084] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Oral chelation therapy with d-penicillamine (d-PCN) has been proven to be effective in the treatment of mild-to-moderate lead poisoning. However, d-PCN is associated with a relatively high incidence of adverse effects when given in the standard dose of 25-30 mg/kg/d. Lower doses of d-PCN may reduce the rate of adverse effects without a significant reduction in the drug's efficacy. OBJECTIVE To examine the incidence of rash, white blood cell and platelet count depression, and abnormal urinalysis with d-PCN when given in a dose of 15 mg/kg/d to children with blood lead concentrations <40 microg/dL. METHODS Retrospective analysis of a clinical treatment course of children who received d-PCN during 1996 in the Lead and Toxicology Clinic of Children's Hospital, Boston. All children were treated under a reduced-dose d-PCN chelation protocol. RESULTS During the study period, 55 children (mean age 37.4 mo) received 66 courses of d-PCN. Mean blood lead concentration before chelation was 24 microg/dL (range 15-37), with a corresponding erythrocyte protoporphyrin concentration of 42 microg/dL. After 77 days of treatment with d-PCN, blood lead concentration was reduced to mean 16 microg/dL (mean fall 35%; p = 0.005) and erythrocyte protoporphyrin was reduced to 28 microg/dL (p = 0.009). During chelation therapy, the white blood cell count fell below 5,000/mm3 in seven cases (9.7%); there were no episodes of platelet counts falling below 150,000/mm3. No cases of abnormal urinalysis were reported; three episodes of rash (4.5%) were recorded. The only patients prematurely terminated from therapy were those who developed rash; in all three cases, drug eruption was an isolated occurrence, which resolved within 48 hours of diphenhydramine therapy. All adverse effects were transient and resolved during or immediately after chelation therapy. CONCLUSIONS Reduced-dose d-PCN appears to maintain efficacy at reducing blood lead concentrations. Reduced-dose d-PCN also appears to be associated with a rate of adverse effects lower than previously reported; observed adverse effects appear to be benign and transient.
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Affiliation(s)
- M W Shannon
- The Pediatric Environmental Health Center, Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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45
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Kostial K, Restek-Samar?ija N, Piasek M, Varnai VM, Blanu?a M, Jones MM, Singh PK. Combined treatment withracemic-DMSA and EDTA for lead mobilization in rats. ACTA ACUST UNITED AC 2000. [DOI: 10.1002/1520-670x(2000)13:3<277::aid-jtra5>3.0.co;2-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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46
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Cremin JD, Luck ML, Laughlin NK, Smith DR. Efficacy of succimer chelation for reducing brain lead in a primate model of human lead exposure. Toxicol Appl Pharmacol 1999; 161:283-93. [PMID: 10620486 DOI: 10.1006/taap.1999.8807] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The extent to which succimer (meso-2,3-dimercaptosuccinic acid [DMSA], Chemet) reduces brain lead (Pb) levels may be a primary consideration in evaluating its efficacy for reducing neurotoxicity. Clinical research in this area has been hampered by the need to use blood Pb levels as the index of treatment efficacy, despite the fact that brain Pb level is the exposure parameter of greater relevance to cognitive outcomes. Here, a nonhuman primate model of human Pb exposure was used to determine: (1) The efficacy of oral succimer for reducing brain Pb derived from chronic or recent exposures, and (2) The extent to which blood Pb levels reflect brain Pb prior to and following chelation. Adult rhesus monkeys were chronically exposed to Pb orally for 5 weeks to reach and maintain a target blood Pb level of 35-40 microg/dL. Chelation of Pb from recent exposures was assessed using a stable (204)Pb isotope tracer administered over 4 days prior to treatment. Immediately prior to chelation, a prefrontal cortex (PFC) biopsy was collected to determine pretreatment brain Pb levels. Subsequently, monkeys were assigned to vehicle (n = 5) or succimer (n = 6, 30 mg/kg/day x 5 days followed by 20 mg/kg/day x 14 days) groups. Blood and brain PFC, frontal lobe (FL), hippocampus (H), and striatum (S) were analyzed for total Pb and (204)Pb tracer concentrations by magnetic sector inductively coupled plasma-mass spectrometry. There were no measurable differences in brain Pb concentrations between the succimer and vehicle groups, indicating that succimer treatment was not efficacious in reducing brain Pb levels. In contrast, the cessation of Pb exposure significantly reduced brain (PFC) Pb ( approximately 34%) when compared to pretreatment levels (succimer and vehicle groups). Pb concentrations also varied among brain regions (PFC > FL approximately H > S). Finally, pretreatment PFC Pb concentrations were significantly correlated with the integrated blood Pb level (AUC) over the Pb exposure period, but not with the single pretreatment blood Pb collected concurrently with the PFC biopsy. Following treatment, blood Pb levels correlated only with Pb in the PFC, and not the other brain regions measured (FL, H, S). These data indicate that, under the conditions of this study, succimer treatment did not reduce brain Pb levels beyond the cessation of Pb exposure alone. Moreover, a single blood Pb measurement may be a poor predictor of brain Pb levels, reflecting limitations in the use of blood Pb level as an indicator of treatment efficacy.
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Affiliation(s)
- J D Cremin
- Environmental Toxicology, University of California, Santa Cruz, California, 95064, USA
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47
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Lever SZ, Parsons TL. The presence of lead decreases the availability of meso-2, 3-dimercaptosuccinic acid for analysis in the monobromobimane assay. Chem Res Toxicol 1999; 12:1057-65. [PMID: 10563831 DOI: 10.1021/tx980247y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
meso-2,3-Dimercaptosuccinic acid is a suitable chelating agent for routine pharmacotherapy of lead poisoning in children. Administration of meso-2,3-dimercaptosuccinic acid presumably permits complexation of lead in vivo, allowing excretion through urine or feces. Quantification of the lead is achieved independently from the analysis of meso-2,3-dimercaptosuccinic acid and metabolites from the monobromobimane assay. To date, no direct chemical characterization of the Pb species excreted in urine has been successful. Pharmacokinetic correlation of lead excretion with excretion of meso-2,3-dimercaptosuccinic acid and metabolites has been utilized as an indirect method to draw conclusions regarding the identity of the active chelating agent. In this study, we hypothesized that the Pb-coordinated thiols are not reactive with respect to monobromobimane, and thus, the active chelator contained in the lead complex escapes detection. We performed variations of the assay and found that (1) the fluorescence detector response for the meso-2,3-dimercaptosuccinic acid-monobromobimane adduct was clearly attenuated as a function of added Pb, (2) when meso-2, 3-dimercaptosuccinic acid and monobromobimane were mixed prior to the addition of lead, the lead had no effect on detector response, (3) the addition of dithiothreitol does not affect the ability of Pb to react with meso-2,3-dimercaptosuccinic acid and verifies that oxidation of meso-DMSA had not occurred, and (4) the addition of ethylenediaminetetraacetic acid to the assay reverses the result found in point 1, presumably through trans chelation of the Pb-DMSA complex. Indirect quantification of the Pb-DMSA complexes found in urine might be accomplished through modification of the standard monobromobimane assay for analysis of meso-2,3-dimercaptosuccinic acid.
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Affiliation(s)
- S Z Lever
- Department of Environmental Health Sciences, The School of Hygiene and Public Health, The Johns Hopkins University, Baltimore, Maryland 21205-2179, USA.
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48
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Andersen O. Principles and recent developments in chelation treatment of metal intoxication. Chem Rev 1999; 99:2683-710. [PMID: 11749497 DOI: 10.1021/cr980453a] [Citation(s) in RCA: 283] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- O Andersen
- Department of Life Sciences and Chemistry, Roskilde University, Postbox 260 4000, Roskilde, Denmark
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49
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Abstract
This study evaluates the effectiveness (use under routine circumstances) of DMSA (2,3 dimercaptosuccinic acid) and environmental remediation as compared with placebo and environmental remediation on children with blood lead (BPb) levels of 30-45 micrograms/dL (1.45-2.17 mumol/L). The endpoints were BPb at 1 month and 6 months after study entry. This double-blind placebo-controlled trial involved 39 children aged 2-5 years, who were randomized to one course of DMSA or placebo. The mean BPb levels of the two groups at study entry were similar, placebo group 33.0 micrograms/dL (1.59 mumol/L) and the DMSA group 34.9 micrograms/dL (1.68 mumol/L). At 1 month (the end of treatment) the mean BPb levels of the two groups were: placebo group 33.2 micrograms/dL (1.60 mumol/L) and the DMSA group 27.4 micrograms/dL (1.32 mumol/L), p = 0.16. At 6 months, the mean BPb levels were 25.1 micrograms/dL (1.21 mumol/L) for the placebo group and 28.8 micrograms/dL (1.39 mumol/L) for the DMSA-treated group, p = 0.06. Neither of these differences is statistically significant. All children with BPb, in the range studied here, should receive environmental evaluation and remediation; DMSA does not improve long-term blood lead levels.
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Affiliation(s)
- M E O'Connor
- Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio, USA
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50
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Farrar HC, McLeane LR, Wallace M, White K, Watson J. A comparison of two dosing regimens of succimer in children with chronic lead poisoning. J Clin Pharmacol 1999; 39:180-3. [PMID: 11563411 DOI: 10.1177/00912709922007615] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
There is limited information defining the optimal dosing regimen of succimer in the treatment of children with chronic lead poisoning. It is typically administered as a five day course of high dose therapy (1,050 mg/m2/day) followed by 14 days of low dose therapy (700 mg/m2/day). This study compared the effect on blood lead concentrations (BPb) of treatment with this standard regimen and an alternate regimen consisting of two courses of high dose therapy separated by one week. There were significant reductions in the mean BPb in both the standard (n = 7) and alternate (n = 4) treatment groups but there was not a significant difference between the groups. In the standard group, the BPb decreased from 33 +/- 4 to 27 +/- 6 mcg/dL. The BPb decreased from 33 +/- 6 to 23 +/- 4 mcg/dL in those treated with alternate therapy. This study suggests that two short courses of high dose therapy may be an acceptable alternative to standard succimer therapy. Because of the small size of this study, other studies are warranted.
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Affiliation(s)
- H C Farrar
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, USA
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