The Experts below are selected from a list of 62514 Experts worldwide ranked by ideXlab platform

Roberto Lucchini - One of the best experts on this subject based on the ideXlab platform.

  • neurofunctional dopaminergic impairment in elderly after lifetime exposure to Manganese
    Neurotoxicology, 2014
    Co-Authors: Silvia Zoni, Chiara Benedetti, Chiara Fedrighi, Marco Peli, Filippo Donna, Stefano Guazzetti, Roberto Lucchini, Elza Bontempi
    Abstract:

    Background Manganese (Mn) is an essential element that can become neurotoxic through various exposure windows over the lifespan. While there is clear evidence of Mn neurotoxicity in pediatric and adult occupational populations, little is known about effects in the elderly who may exhibit enhanced susceptibilities due to compromised physiology compared to younger adults. In the province of Brescia, Italy, the Valcamonica area has been the site of three ferroalloy plants operating from 1902 to 2001. Metal emissions of Mn and to a lesser extent lead (Pb) have impacted the surrounding environment, where a high prevalence of Parkinsonism was previously observed. This study aimed to assess neurocognitive and motor functions in healthy elderly subjects residing for most of their lifetime in Valcamonica or in a reference area unimpacted by ferroalloy plant activity.

  • inverse association of intellectual function with very low blood lead but not with Manganese exposure in italian adolescents
    Environmental Research, 2012
    Co-Authors: Roberto Lucchini, Silvia Zoni, Karin Broberg, Giovanni Parrinello, Serena Micheletti, Stefano Guazzetti, Elza Bontempi, Donald R Smith
    Abstract:

    Background Pediatric lead (Pb) exposure impacts cognitive function and behavior and co-exposure to Manganese (Mn) may enhance neurotoxicity.

  • atp13a2 park9 polymorphisms influence the neurotoxic effects of Manganese
    Neurotoxicology, 2012
    Co-Authors: Gerda Rentschler, Silvia Zoni, Roberto Lucchini, Loredana Covolo, Amelia Ahmadi Haddad, Karin Broberg
    Abstract:

    Introduction A higher prevalence of individuals affected by Parkinsonism was found in Valcamonica, Italy. This may be related to ferro-alloy smelters in the area, releasing Manganese (Mn) in the air, soil and water for about a century. There exists individual susceptibility for Mn neurotoxicity.

  • peripheral markers of catecholamine metabolism among workers occupationally exposed to Manganese Mn
    Toxicology Letters, 1995
    Co-Authors: Audrey Smargiassi, Roberto Lucchini, Donna Mergler, Enrico Bergamaschi, Maria Vittoria Vettori, Pietro Apostoli
    Abstract:

    In a preliminary study of 11 men randomly selected in a ferro-alloy plant and of 15 control subjects, platelet monoamine oxidase (MAO) and serum dopamine beta-hydroxylase (DBH) activities were measured. A tendency towards lower MAO-B activity in the exposed workers as compared to control subjects (t = 1.95; P = 0.06) was found whereas DBH activity was similar. In the exposed group, a dose-effect relationship was noted between a Manganese (Mn) cumulative exposure index (CEI) and DBH activity (R2 = 0.40, P < 0.05). Since DBH is an expression of catecholamine release, the relative increase in such activity could be envisaged as a compensatory mechanism to a reduced turnover rate as reflected by MAO-B activity. Owing to the limited sample size, these findings should be confirmed by further epidemiological and experimental studies.

Michael Aschner - One of the best experts on this subject based on the ideXlab platform.

  • Manganese in the Diet: Bioaccessibility, Adequate Intake, and Neurotoxicological Effects.
    Journal of agricultural and food chemistry, 2020
    Co-Authors: Airton Cunha Martins, Bárbara Nunes Krum, Libânia Sofia Seixas Queirós, Alexey A. Tinkov, Anatoly V. Skalny, Aaron B. Bowman, Michael Aschner
    Abstract:

    Manganese (Mn) is an essential element that participates in several biological processes. Mn serves as a cofactor for several enzymes, such as glutamine synthetase and oxidoreductases, that have an important role in the defense of the organisms against oxidative stress. The diet is the main source of Mn intake for humans, and adequate daily intake levels for this metal change with age. Moreover, in higher amounts, Mn may be toxic, mainly to the brain. Here, we provide an overview of Mn occurrence in food, addressing its bioaccessibility and discussing the dietary standard and recommended intake of Mn consumption. In addition, we review some mechanisms underlying Mn-induced neurotoxicity.

  • protective effects of ebselen ebs and para aminosalicylic acid pas against Manganese Mn induced neurotoxicity
    Toxicology and Applied Pharmacology, 2012
    Co-Authors: A Marreilha Dos P Santos, Michael Aschner, Rui Lucas, Vanda Andrade, Luisa M Mateus, Dejan Milatovic, Camila M Batoreu
    Abstract:

    Chronic, excessive exposure to Manganese (Mn) may induce neurotoxicity and cause an irreversible brain disease, referred to as manganism. Efficacious therapies for the treatment of Mn are lacking, mandating the development of new interventions. The purpose of the present study was to investigate the efficacy of ebselen (Ebs) and para-aminosalicylic acid (PAS) in attenuating the neurotoxic effects of Mn in an in vivo rat model. Exposure biomarkers, inflammatory and oxidative stress biomarkers, as well as behavioral parameters were evaluated. Co-treatment with Mn plus Ebs or Mn plus PAS caused a significant decrease in blood and brain Mn concentrations (compared to rats treated with Mn alone), concomitant with reduced brain E₂ prostaglandin (PGE₂) and enhanced brain glutathione (GSH) levels, decreased serum prolactin (PRL) levels, and increased ambulation and rearing activities. Taken together, these results establish that both PAS and Ebs are efficacious in reducing Mn body burden, neuroinflammation, oxidative stress and locomotor activity impairments in a rat model of Mn-induced toxicity.

  • Manganese (Mn) and Iron (Fe): Interdependency of Transport and Regulation
    Neurotoxicity Research, 2010
    Co-Authors: Vanessa A. Fitsanakis, Na Zhang, Stephanie Garcia, Michael Aschner
    Abstract:

    Manganese (Mn) and iron (Fe) are transition metals that are crucial to the appropriate growth, development, function, and maintenance of biological organisms. Because of their chemical similarity, in organisms ranging from bacteria to mammals they share and compete for many protein transporters, such as the divalent metal transporter-1. As such, during conditions of low Fe, abnormal Mn accumulation occurs. Conversely, when Mn concentrations are altered, the homeostasis and deposition of Fe and other transition metals are disrupted. Our lab has undertaken a series of studies in rats involving pregnant dams, neo- and perinatal pups, and adult animals. Animals were exposed to various concentrations of dietary Fe and/or Mn, and protein transporter expression, blood Mn and Fe concentrations, brain transition metal concentrations, and temporal brain deposition patterns were examined. As a result, we have demonstrated the importance of the interdependence of the transport of Mn and Fe, and established brain metal concentrations in several longitudinal studies. The purpose of this review is to examine these studies in their entirety and highlight the importance of monitoring the deposition and accumulation of both Mn and Fe when designing future studies related to either dietary or environmental changes in transition metal levels. Finally, this review will provide information about various transport proteins currently under investigation in the research community related to Fe and Mn regulation and transport.

  • Manganese recent advances in understanding its transport and neurotoxicity
    Toxicology and Applied Pharmacology, 2007
    Co-Authors: Michael Aschner, Tomas R Guilarte, Jay S Schneider, Wei Zheng
    Abstract:

    The present review is based on presentations from the meeting of the Society of Toxicology in San Diego, CA (March 2006). It addresses recent developments in the understanding of the transport of Manganese (Mn) into the central nervous system (CNS), as well as brain imaging and neurocognitive studies in non-human primates aimed at improving our understanding of the mechanisms of Mn neurotoxicity. Finally, we discuss potential therapeutic modalities for treating Mn intoxication in humans.

Donald R Smith - One of the best experts on this subject based on the ideXlab platform.

Wei Zheng - One of the best experts on this subject based on the ideXlab platform.

  • customized compact neutron activation analysis system to quantify Manganese Mn in bone in vivo
    Physiological Measurement, 2017
    Co-Authors: Yingzi Liu, Wei Zheng, Farshad Mostafaei, Daniel Sowers, Mindy Hsieh, Linda H Nie
    Abstract:

    Objective: In the US alone, millions of workers, including over 300 000 welders, are at high risk of occupational Manganese (Mn) exposure. Those who have been chronically exposed to excessive amount of Mn can develop severe neurological disorders similar, but not identical, to the idiopathic Parkinson's disease. One challenge of identifing the health effects of Mn exposure is to find a reliable biomarker for exposure assessment, especially for long-term cumulative exposure. Approach: Mn's long biological half-life as well as its relatively high concentration in bone makes bone Mn (BnMn) a potentially valuable biomarker for Mn exposure. Our group has been working on the development of a deuterium–deuterium (D–D)-based neutron generator to quantify Mn in bone in vivo. Main results and significance: In this paper, we report the latest advancements in our system. With a customized hand irradiation assembly, a fully characterized high purity germanium (HPGe) detector system, and an acceptable hand dose of 36 mSv, a detection limit of 0.64 µg Mn/g bone (ppm) has been achieved.

  • a compact dd neutron generator based naa system to quantify Manganese Mn in bone in vivo
    Physiological Measurement, 2014
    Co-Authors: Yingzi Liu, Patrick Byrne, Haoyu Wang, D Koltick, Wei Zheng, Linda H Nie
    Abstract:

    A deuterium-deuterium (DD) neutron generator–based neutron activation analysis (NAA) system has been developed to quantify metals, including Manganese (Mn), in bone in vivo. A DD neutron generator with a flux of up to 3*109 neutrons s−1 was set up in our lab for this purpose. Optimized settings, including moderator, reflector, and shielding material and thickness, were selected based on Monte Carlo (MC) simulations conducted in our previous work. Hand phantoms doped with different Mn concentrations were irradiated using the optimized DD neutron generator irradiation system. The Mn characteristic γ-rays were collected by an HPGe detector system with 100% relative efficiency. The calibration line of the Mn/calcium (Ca) count ratio versus bone Mn concentration was obtained (R2 = 0.99) using the hand phantoms. The detection limit (DL) was calculated to be about 1.05 μg g−1 dry bone (ppm) with an equivalent dose of 85.4 mSv to the hand. The DL can be reduced to 0.74 ppm by using two 100% HPGe detectors. The whole body effective dose delivered to the irradiated subject was calculated to be about 17 μSv. Given the average normal bone Mn concentration of 1 ppm in the general population, this system is promising for in vivo bone Mn quantification in humans.

  • Manganese recent advances in understanding its transport and neurotoxicity
    Toxicology and Applied Pharmacology, 2007
    Co-Authors: Michael Aschner, Tomas R Guilarte, Jay S Schneider, Wei Zheng
    Abstract:

    The present review is based on presentations from the meeting of the Society of Toxicology in San Diego, CA (March 2006). It addresses recent developments in the understanding of the transport of Manganese (Mn) into the central nervous system (CNS), as well as brain imaging and neurocognitive studies in non-human primates aimed at improving our understanding of the mechanisms of Mn neurotoxicity. Finally, we discuss potential therapeutic modalities for treating Mn intoxication in humans.

  • effective treatment of Manganese induced occupational parkinsonism with p aminosalicylic acid a case of 17 year follow up study
    Journal of Occupational and Environmental Medicine, 2006
    Co-Authors: Yueming Jiang, Xiayan Zhu, Hongyu Gao, Jinlan Xie, Fengling Liao, Enrico Pira, Wei Zheng
    Abstract:

    Objective:Chronic Manganese (Mn) intoxication induces syndromes resembling Parkinson disease. The clinical intervention has largely been unsuccessful. We report a 17-year follow-up study of effective treatment of occupational Mn parkinsonism with sodium para-aminosalicylic acid (PAS).Methods:The pat

Maryse F Bouchard - One of the best experts on this subject based on the ideXlab platform.