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1.
Sci Total Environ ; 720: 137666, 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32325596

RESUMO

Sodium dimethyldithiocarbamate (SDDC) is a widely used heavy metal chelating agent in harmless treatment of wastewater and hazardous waste, but SDDC and its heavy metal chelates may leak into the environment and bring potential ecological risks. In this study, the model organism Caenorhabditis elegans was used to evaluate the toxic effect of SDDC and its heavy metal Cu, Pb chelates. Multiple endpoints were investigated by subacute exposure to SDDC (0.01-100 mg/L) and micro-sized Cu, Pb chelates of SDDC (1-100 mg/L). Our data indicated that the LC50 value of SDDC was 139.39 mg/L (95% Cl: 111.03, 174.75 mg/L). In addition, SDDC was found that concentration of 1 mg/L is a safe limit value for nematode C. elegans, and concentration above 1 mg/L caused adverse effects on the survival, growth, locomotion behaviors and reactive oxygen species (ROS) production of exposed nematodes. Furthermore, all tested SDDC-Cu and SDDC-Pb chelates had obviously lower toxic effect than untreated Cu, Pb metals. These two chelates also had a lower toxic effect than SDDC agent due to its more stable structure. Moreover, SDDC-Cu had a higher toxic effect than SDDC-Pb at the same concentration. Thus, our results suggest that SDDC as a kind of chelating agent applied in harmless treatment of heavy metals, the safe addition limit should not be exceeded.


Assuntos
Caenorhabditis elegans , Animais , Quelantes , Dimetilditiocarbamato , Metais Pesados , Sódio
2.
Artigo em Inglês | MEDLINE | ID: mdl-30201584

RESUMO

We investigated toxic effects of the antifouling biocide polycarbamate (PC) on marine fish by conducting acute, early-life stage toxicity (ELS), and embryo toxicity tests. Mummichog (Fundulus heteroclitus) 96-h LC50 values for hatched larvae (body weight about 2.0 mg) and juveniles (660 ±â€¯36 mg) were about 12 and 630 µg/L, respectively. The ELS test using mummichog embryos yielded a lowest-observed-effect concentration of 3.9 µg/L and a no-observed-effect concentration of 2.1 µg/L with growth as the most sensitive endpoint. The embryo toxicity test for spotted halibut (Verasper variegatus) revealed a 10-d EC50 of 8.1 µg/L with abnormality as an endpoint. During the ELS and embryo toxicity tests, morphological abnormalities (notochord undulation) were induced in the embryos. Biochemical and gene-expression analysis suggest that PC-induced morphological abnormalities involve disruption of lysyl oxidase-mediated collagen fiber organization, essential for notochord formation, and inhibition of gene expression related to notochord formation.


Assuntos
Dimetilditiocarbamato/análogos & derivados , Desenvolvimento Embrionário/efeitos dos fármacos , Linguado/fisiologia , Fundulidae/fisiologia , Fungicidas Industriais/toxicidade , Tiocarbamatos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Aquicultura , Dimetilditiocarbamato/toxicidade , Desinfetantes/toxicidade , Embrião não Mamífero/anormalidades , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/metabolismo , Inibidores Enzimáticos/toxicidade , Feminino , Proteínas de Peixes/antagonistas & inibidores , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Linguado/embriologia , Fundulidae/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/metabolismo , Dose Letal Mediana , Masculino , Mutagênicos/toxicidade , Nível de Efeito Adverso não Observado , Proteína-Lisina 6-Oxidase/antagonistas & inibidores , Proteína-Lisina 6-Oxidase/metabolismo , Testes de Toxicidade Aguda , Testes de Toxicidade Crônica
3.
Neurotoxicology ; 66: 107-120, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29605442

RESUMO

The primary etiology of Parkinson's disease (PD) remains unclear, but likely reflects a combination of genetic and environmental factors. Exposure to some pesticides, including ziram (zinc dimethyldithiocarbamate), is a relevant risk factor for PD. Like some other environmental neurotoxicants, we hypothesized that ziram can enter the central nervous system from the nasal mucosa via the olfactory nerves. To address this issue, we evaluated the effects of 1, 2 or 4 days of intranasal (i.n., 1 mg/nostril/day) infusions of sodium dimethyldithiocarbamate (NaDMDC), a dimethyldithiocarbamate more soluble than ziram, on locomotor activity in the open field, neurological severity score and rotarod performance. We also addressed the effects of four daily i.n. NaDMDC infusions on olfactory bulb (OB) and striatal measures of cell death, reactive oxygen species (ROS), tyrosine hydroxylase, and the levels of dopamine, noradrenaline, serotonin, and their metabolites. A single i.n. administration of NaDMDC did not significantly alter the behavioral measures. Two consecutive days of i.n. NaDMDC administrations led to a transient neurological deficit that spontaneously resolved within a week. However, the i.n. infusions of NaDMDC for 4 consecutive days induced motor and neurological deficits for up to 7 days after the last NaDMDC administration and increased striatal TH immunocontent and dopamine degradation within a day of the last infusion. Pharmacological treatment with the anti-parkinsonian drugs l-DOPA and apomorphine improved the NaDMDC-induced locomotor deficits. NaDMDC increased serotonin levels and noradrenaline metabolism in the OB 24 h after the last NaDMDC infusion, ROS levels in the OB 2 h after the last infusion, and striatum 2 and 24 h after the last infusion. These results demonstrate, for the first time, that i.n. NaDMDC administration induces neurobehavioral and neurochemical impairments in mice. This accords with evidence that dimethyldithio-carbamate exposure increases the risk of PD and highlights the possibility that olfactory system could be a major route for NaDMDC entry to central nervous system.


Assuntos
Corpo Estriado/efeitos dos fármacos , Dimetilditiocarbamato/toxicidade , Dopamina/metabolismo , Atividade Motora/efeitos dos fármacos , Bulbo Olfatório/efeitos dos fármacos , Doença de Parkinson Secundária/metabolismo , Administração Intranasal , Animais , Corpo Estriado/metabolismo , Dimetilditiocarbamato/administração & dosagem , Hipotermia/induzido quimicamente , Masculino , Camundongos , Bulbo Olfatório/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio , Tirosina 3-Mono-Oxigenase
4.
J Chromatogr Sci ; 55(4): 429-435, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-27999077

RESUMO

A simple method combining ion-pair methylation, high-performance liquid chromatography (HPLC) analysis with detection at 272 nm and atomic absorption spectrometry was developed in order to determine 10 dithiocarbamate fungicides (Dazomet, Metam-sodium, Ferbam, Ziram, Zineb, Maneb, Mancozeb, Metiram, Nabam and Propineb) and distinguish ethylenbisdithiocarbamates (EBDTCs) Zineb, Maneb and Mancozeb in diverse matrices. This method associates reverse phase analysis by HPLC analysis with detection at 272 nm, with atomic absorption spectrometry in order to distinguish, with the same extraction protocol, Maneb, Mancozeb and Zineb. The limits of detection (0.4, 0.8, 0.5, 1.25 and 1.97) and quantification (1.18, 2.5, 1.52, 4.2 and 6.52) calculated in injected nanogram, respectively, for Dazomet, Metam-Na, dimethyldithiocarbamates (DMDTCs), EBDTCs and propylenebisdithiocarbamates (PBDTCs) justify the sensitivity of the method used. The coefficients of determination R2 were 0.9985, 0.9978, 0.9949, 0.988 and 0.9794, respectively, for Dazomet, Metam-Na, DMDTCs, EBDTCs and PBDTCs, and the recovery from fortified apple and leek samples was above 90%. Results obtained with the atomic absorption method in comparison with spectrophotometric analysis focus on the importance of the atomic absorption as a complementary specific method for the distinction between different EBDTCs fungicides.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Dimetilditiocarbamato/análise , Fungicidas Industriais/análise , Espectrofotometria Atômica/métodos , Verduras/química , Dimetilditiocarbamato/química , Fungicidas Industriais/química , Limite de Detecção , Reprodutibilidade dos Testes
5.
Sci Total Environ ; 554-555: 246-52, 2016 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26956173

RESUMO

Growing concerns over the potential release and threat of silver nanoparticles (AgNPs) to environmental and biological systems urge researchers to investigate their fate and behavior. However, current analytical techniques cannot meet the requirements for rapidly, sensitively and reliably probing AgNPs in complex matrices. Surface-enhanced Raman spectroscopy (SERS) has shown great capability for rapid detection of AgNPs based on an indicator molecule that can bind on the AgNP surface. The objective of this study was to exploit SERS to detect AgNPs in environmental and biological samples through optimizing the Raman indicator for SERS. Seven indicator molecules were selected and determined to obtain their SERS signals at optimal concentrations. Among them, 1,2-di(4-pyridyl)ethylene (BPE), crystal violet and ferric dimethyl-dithiocarbamate (ferbam) produced the highest SERS intensities. Further experiments on binding competition between each two of the three candidates showed that ferbam had the highest AgNPs-binding ability. The underlying mechanism lies in the strong binding affinity of ferbam with AgNPs via multiple sulfur atoms. We further validated ferbam to be an effective indicator for SERS detection of as low as 0.1mg/L AgNPs in genuine surface water and 0.57 mg/L in spinach juice. Moreover, limited interference on SERS detection of AgNPs was found from environmentally relevant inorganic ions, organic matter, inorganic particles, as well as biologically relevant components, demonstrating the ferbam-assisted SERS is an effective and sensitive method to detect AgNPs in complex environmental and biological samples.


Assuntos
Nanopartículas Metálicas/análise , Prata/análise , Análise Espectral Raman , Dimetilditiocarbamato , Nanopartículas Metálicas/química , Prata/química , Propriedades de Superfície
6.
Nanoscale ; 7(48): 20709-16, 2015 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-26601853

RESUMO

Single nanoparticle analysis (SNA) technique with the aid of a dark-field microscopic imaging (iDFM) technique has attracted wide attention owing to its high sensitivity. Considering that the degradation of pesticides can bring about serious problems in food and the environment, and that the real-time monitoring of the dynamic degradation process of pesticides can help understand and define their degradation mechanisms, herein we real-time monitored the decomposition dynamics of sodium dimethyldithiocarbamate (NaDDC) under neutral and alkaline conditions by imaging single silver nanoparticles (AgNPs) under a dark-field microscope (DFM); the localized surface plasmon resonance (LSPR) scattering signals were measured at a single nanoparticle level. As a result, the chemical mechanism of the degradation of NaDDC under neutral and alkaline conditions was proposed, and the inhibition effects of metal ions including Zn(II) and Cu(II) were investigated in order to understand the decomposition process in different environments. It was found that Cu(II) forms the most stable complex with NaDDC with a stoichiometric ratio of 1 : 2, which greatly reduces the toxicity.


Assuntos
Dimetilditiocarbamato/química , Nanopartículas Metálicas/química , Praguicidas/química , Prata/química , Ressonância de Plasmônio de Superfície/métodos , Cobre/química , Zinco/química
7.
Int J Environ Res Public Health ; 12(4): 3633-45, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25837344

RESUMO

We previously found that carbamate pesticides induced significant apoptosis in human natural killer cells. To investigate whether carbamate pesticides also induce apoptosis in human T lymphocytes, in the present study Jurkat human T cells were treated in vitro with thiram, maneb, carbaryl or ziram. Apoptosis was determined by FITC-Annexin-V/PI staining. To explore the mechanism of apoptosis, intracellular levels of active caspase 3 and mitochondrial cytochrome-c release were determined by flow cytometry. We found that thiram, ziram, maneb and carbaryl also induced apoptosis in a time- and dose-dependent manner in the human T cells. However, the strength of the apoptosis-inducing effect differed among the pesticides, with the: thiram > ziram > maneb > carbaryl. Moreover, thiram significantly increased the intracellular level of active caspase 3 and caspase inhibitors significantly inhibited apoptosis. Thiram also significantly caused mitochondrial cytochrome-c release. These findings indicate that carbamate pesticides can induce apoptosis in human T cells, and the apoptosis is mediated by the activation of caspases and the release of mitochondrial cytochrome-c.


Assuntos
Apoptose/efeitos dos fármacos , Carbamatos/toxicidade , Praguicidas/toxicidade , Linfócitos T/efeitos dos fármacos , Apoptose/fisiologia , Biomarcadores/metabolismo , Carbaril/toxicidade , Caspase 3/metabolismo , Citocromos c/metabolismo , Dimetilditiocarbamato/toxicidade , Citometria de Fluxo , Humanos , Células Jurkat , Maneb/toxicidade , Linfócitos T/fisiologia
8.
Environ Sci Technol ; 49(7): 4317-24, 2015 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-25775209

RESUMO

Silver nanoparticles (AgNPs) are the most commonly used nanoparticles in consumer products. Concerns over human exposure to and risk from these particles have resulted in increased interest in novel strategies to detect AgNPs. This study investigated the feasibility of surface-enhanced Raman spectroscopy (SERS) as a method for the detection and quantification of AgNPs in antimicrobial products. By using ferbam (ferric dimethyl-dithiocarbamate) as an indicator molecule that binds strongly onto the nanoparticles, AgNPs detection and discrimination were achieved based on the signature SERS response of AgNPs-ferbam complexes. SERS response with ferbam was distinct for silver ions, silver chloride, silver bulk particles, and AgNPs. Two types of AgNPs with different coatings, citrate and polyvinylpirrolidone (PVP), both showed strong interactions with ferbam and induced strong SERS signals. SERS was effectively applicable for detecting Ag particles ranging from 20 to 200 nm, with the highest signal intensity in the 60-100 nm range. A linear relationship (R(2) = 0.9804) between Raman intensity and citrate-AgNPs concentrations (60 nm; 0-20 mg/L) indicates the potential for particle quantification. We also evaluated SERS detection of AgNPs in four commercially available antimicrobial products. Combined with ICP-MS and TEM data, the results indicated that the SERS response is primarily dependent on size, but also affected by AgNPs concentration. The findings demonstrate that SERS is a promising analytical platform for studying environmentally relevant levels of AgNPs in consumer products and related matrices.


Assuntos
Anti-Infecciosos/análise , Nanopartículas Metálicas/análise , Prata/química , Análise Espectral Raman/métodos , Anti-Infecciosos/química , Citratos/química , Corantes/química , Dimetilditiocarbamato/química , Humanos , Nanopartículas Metálicas/química , Polivinil/química , Pirrolidinas/química , Compostos de Prata/química
9.
Chem Res Toxicol ; 28(4): 682-90, 2015 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-25714994

RESUMO

Ubiquitin activating enzyme E1 plays a pivotal role in ubiquitin based protein signaling through regulating the initiating step of the cascade. Previous studies demonstrated that E1 is inhibited by covalent modification of reactive cysteines contained within the ubiquitin-binding groove and by conditions that increase oxidative stress and deplete cellular antioxidants. In this study, we determined the relative contribution of covalent adduction and oxidative stress to E1 inhibition produced by ziram and sodium N,N-dimethyldithiocarbamate (DMDC) in HEK293 cells. Although no dithiocarbamate-derived E1 adducts were identified on E1 using shotgun LC/MS/MS for either ziram or DMDC, both dithiocarbamates significantly decreased E1 activity, with ziram demonstrating greater potency. Ziram increased intracellular levels of zinc and copper, DMDC increased intracellular levels of only copper, and both dithiocarbamates enhanced oxidative injury evidenced by elevated levels of protein carbonyls and expression of heme oxygenase-1. To assess the contribution of intracellular copper transport to E1 inhibition, coincubations were performed with the copper chelator triethylenetetramine hydrochloride (TET). TET significantly protected E1 activity for both of the dithiocarbamates and decreased the associated oxidative injury in HEK293 cells as well as prevented dithiocarbamate-mediated lipid peroxidation assayed using an ethyl aracidonate micelle system. Because TET did not completely ameliorate intracellular transport of copper or zinc for ziram, TET apparently maintained E1 activity through its ability to diminish dithiocarbamate-mediated oxidative stress. Experiments to determine the relative contribution of elevated intracellular zinc and copper were performed using a metal free incubation system and showed that increases in either metal were sufficient to inhibit E1. To evaluate the utility of the HEK293 in vitro system for screening environmental agents, a series of additional pesticides and metals was assayed, and eight agents that produced a significant decrease and five that produced a significant increase in activated E1 were identified. These studies suggest that E1 is a sensitive redox sensor that can be modulated by exposure to environmental agents and can regulate downstream cellular processes.


Assuntos
Dimetilditiocarbamato/toxicidade , Fungicidas Industriais/toxicidade , Metais/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ubiquitina/metabolismo , Ziram/toxicidade , Transporte Biológico , Células HEK293 , Humanos
10.
Chemosphere ; 131: 225-31, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25563163

RESUMO

The primary ecological risk of dimethyldithiocarbamate (DMDC), a dithiocarbamate fungicide (DTC) metabolite, was evaluated based on their probabilistic environmental concentration distributions (ECDs) in the coastal environment, Hiroshima Bay, Japan. And their behavior and temporal trends was further considered. This is the first report of the identification of DMDC from environmental seawater and sediment samples. DMDC concentrations in bottom seawater were substantially higher than those in surface seawater, which are associated with the leachability from sediments in bottom seawaters, and with photodegradation in surface seawaters. Furthermore, seasonal risks are dominated by higher concentrations from April to June, indicating temporal variation in the risk to exposed species. Hierarchical Bayesian analysis offered DMDC ECD medians and range (5th to 95th percentiles) of 0.85 ng L(-1) (0.029, 22), 12 ng L(-1) (3.2, 48) and 110 ng kg dry(-1) (9.5, 1200) in surface seawater, bottom seawater and sediment, respectively. Considering that DMDC and DTCs have similar toxicological potential to aquatic organisms, the occurrence of the compound in water is likely to be of biological relevance. In summary, this work provides the first demonstration that the ecological risk of DMDC and its derived DTCs in Hiroshima Bay is relatively high, and that DTCs should be a high priority for future research on marine contamination, especially in bottom seawaters.


Assuntos
Dimetilditiocarbamato/análise , Fungicidas Industriais/análise , Poluentes Químicos da Água/análise , Organismos Aquáticos , Teorema de Bayes , Monitoramento Ambiental , Japão , Risco , Medição de Risco , Água do Mar/análise
11.
J Food Prot ; 77(12): 2081-7, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25474054

RESUMO

This study investigated the feasibility of detecting pesticides using terahertz (THz) spectroscopy in high-density polyethylene and/or wheat flour mixtures. The absorption spectra of seven pesticides (dicofol, chlorpyrifos, chlorpyrifos-methyl, daminozide, imidacloprid, diethyldithiocarbamate, and dimethyldithiocarbamate) were measured in the frequency range 0.1 to 3 THz at room temperature. Five of the seven pesticides exhibited specific absorption peaks in the low-energy THz range. The two remaining pesticides had no specific absorption peaks in this frequency range, but they exhibited different frequency-dependent refractive indices. The absorption coefficients of imidacloprid increased with its increasing weight ratio in high-density polyethylene, and the fitted power absorptions and refractive indices using a Maxwell-Garnett effective medium model were comparable to the measured data. Imidacloprid was also identified from its characteristic absorption peaks in wheat flour mixtures, and a linear relationship between the absorption coefficient and the weight ratio was observed. Our results show the potential of detection of selected pesticides in foods, such as wheat flour, using THz spectroscopy.


Assuntos
Farinha/análise , Praguicidas/análise , Espectroscopia Terahertz , Triticum/química , Carbamatos/análise , Clorpirifos/análogos & derivados , Clorpirifos/análise , Dicofol/análise , Dimetilditiocarbamato/análise , Ditiocarb/análise , Estudos de Viabilidade , Imidazóis/análise , Análise dos Mínimos Quadrados , Neonicotinoides , Nitrocompostos/análise , Polietileno , Sementes/química , Succinatos/análise
12.
J Environ Sci (China) ; 26(3): 566-74, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-25079269

RESUMO

N,N-Dimethyldithiocarbamate (DMDTC) is a typical precursor of N-nitrosodimethylamine (NDMA). Based on separate hydrolysis, sorption and biodegradation studies of DMDTC, a laboratory-scale anaerobic-anoxic-oxic (AAO) system was established to investigate the removal mechanism of DMDTC in this nutrient removal biological treatment system. DMDTC hydrolyzed easily in water solution under either acidic conditions or strong alkaline conditions, and dimethylamine (DMA) was the main hydrolysate. Under anaerobic, anoxic or oxic conditions, DMDTC was biodegraded and completely mineralized. Furthermore, DMA was the main intermediate in DMDTC biodegradation. In the AAO system, the optimal conditions for both nutrient and DMDTC removal were hydraulic retention time 8 hr, sludge retention time 20 day, mixed-liquor return ratio 3:1 and sludge return ratio 1:1. Under these conditions, the removal efficiency of DMDTC reached 99.5%; the removal efficiencies of chemical organic demand, ammonium nitrogen, total nitrogen and total phosphorus were 90%, 98%, 81% and 93%, respectively. Biodegradation is the dominant mechanism for DMDTC removal in the AAO system, which was elucidated as consisting of two steps: first, DMDTC is transformed to DMA in the anaerobic and anoxic units, and then DMA is mineralized to CO2 and NH3 in the anoxic and oxic units. The mineralization of DMDTC in the biological treatment system can effectively avoid the formation of NDMA during subsequent disinfection processes.


Assuntos
Dimetilditiocarbamato/química , Esgotos/química , Gerenciamento de Resíduos , Adsorção , Anaerobiose , Dimetilditiocarbamato/metabolismo , Hidrólise , Oxirredução
13.
Water Res ; 47(2): 725-36, 2013 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-23176828

RESUMO

Two most commonly used dithiocarbamate (DTC) pesticides, dimethyldithiocarbamate (DMDTC) and diethyldithiocarbamate (DEDTC), were examined in this study to evaluate their potential to form nitrosamines when in contact with various water disinfection oxidants. Results show that DTCs can serve as nitrosamine precursors, by release of secondary amines through hydrolysis or through reactions with oxidants. The reactions of DTCs with monochloramine and ozone were found to be particularly problematic in the risk of generating nitrosamines, though all four tested oxidants, including free chlorine and chlorine dioxide, formed nitrosamines. NDEA yield from DEDTC was lower, by different degrees, than NDMA yield from DMDTC for all four oxidants, which was attributed to the steric hindrance associated with bulkier reaction intermediate that are more difficult to be further oxidized to form nitrosamine. The yield of nitrosamines increased with the oxidant dosage for both monochloramination and ozonation of DTCs. Results for nitrosamine formation from DTCs at varying pH were found to be consistent with the pH trend of nitrosamine formation from ozonation and monochloramination of secondary amines. Kinetic study results and identification and quantification of reaction products suggest that the DTCs were not significant direct precursors of nitrosamines during monochloramination or ozonation, but rather nitrosamines formed were primarily from reaction of oxidants with the amine which may be generated either through hydrolysis or through oxidation of DTCs.


Assuntos
Carcinógenos Ambientais/análise , Desinfetantes/química , Nitrosaminas/análise , Oxidantes/química , Praguicidas/química , Tiocarbamatos/química , Purificação da Água , Carcinógenos Ambientais/química , Cloraminas/química , Dimetilditiocarbamato/química , Ditiocarb/química , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Nitrosaminas/química , Concentração Osmolar , Oxirredução , Ozônio/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química
14.
Analyst ; 137(21): 5082-7, 2012 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-22977883

RESUMO

We report the use of gold nanorods as solution-based SERS substrates for the detection of ultralow-levels of three different dithiocarbamate fungicides: thiram, ferbam and ziram. Gold nanorods are attractive to use as SERS substrates due to the ability to tune the surface plasmon resonance of the nanoparticles to the laser excitation wavelength of the Raman spectrometer equipped with a 785 nm diode laser. The gold nanorods are synthesized using a seed-mediated growth method and characterized using UV-Visible spectroscopy, zeta potential, and TEM. The gold nanorods have an aspect ratio of 2.19 ± 0.21 and have an average length of 37.81 ± 4.83 nm. SERS spectra are acquired at different concentrations of each fungicide and calibration curves are obtained by monitoring the intensity of the band arising from the ν(C-N) stretching mode coupled to the symmetric δ(CH(3)) motion. The limits of detection and limits of quantitation are obtained for each fungicide. The limits of detection are 11.00 ± 0.95 nM, 8.00 ± 1.01 nM, and 4.20 ± 1.22 nM for thiram, ferbam, and ziram respectively. The limits of quantitation are 34.43 ± 0.95 nM, 25.61 ± 1.01 nM, and 12.94 ± 1.22 nM for thiram, ferbam, and ziram respectively. It can be seen that the three different dithiocarbamates can be detected in the low nM range based on the limits of detection that are achieved.


Assuntos
Dimetilditiocarbamato/análise , Ouro/química , Nanotubos/química , Praguicidas/análise , Análise Espectral Raman/métodos , Cetrimônio , Compostos de Cetrimônio/química , Análise por Conglomerados , Dimetilditiocarbamato/química , Limite de Detecção , Praguicidas/química , Análise de Componente Principal , Propriedades de Superfície
15.
PLoS One ; 7(7): e40400, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22815746

RESUMO

Menkes disease is a fatal neurodegenerative disorder in infants caused by mutations in the gene ATP7A which encodes a copper (Cu) transporter. Defects in ATP7A lead to accumulated copper in the small intestine and kidneys and to copper deficiencies in the brain and the liver. The copper level in the kidney in postnatal copper-treated Menkes patients may reach toxic levels. The mouse model, mosaic Atp7a (mo-ms) recapitulates the Menkes phenotype and die about 15.75±1.5 days of age. In the present study we found that prenatal treatment of mosaic murine fetuses throughout gestation days 7, 11, 15 and 18 with a combination of CuCl(2) (50 mg/kg) and dimethyldithiocarbamate (DMDTC) (280 mg/kg) leads to an increase in survival to about 76±25.3 days, whereas treatment with CuCl(2) alone (50 mg/kg) only leads to survival for about 21 days ±5 days. These copper-DMDTC treated mutants showed an improved locomotor activity performance and a gain in body mass. In contrast to treatment with CuCl(2) alone, a significant increase in the amount of copper was observed in the brain after prenatal copper-DMDTC treatment as well as a decrease in the amount of accumulated copper in the kidney, both leading towards a normalization of the copper level. Although copper-DMDTC prenatal treatment only leads to a small increase in the sub-normal copper concentration in the liver and to an increase of copper in the already overloaded small intestine, the combined results suggest that prenatal copper-DMDTC treatment also should be considered for humans.


Assuntos
Cobre/farmacologia , Suplementos Nutricionais , Dimetilditiocarbamato/farmacologia , Síndrome dos Cabelos Torcidos/tratamento farmacológico , Cuidado Pré-Natal/métodos , Animais , Comportamento Animal/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Cobre/metabolismo , Cobre/uso terapêutico , Dimetilditiocarbamato/uso terapêutico , Modelos Animais de Doenças , Interações Medicamentosas , Feminino , Hemizigoto , Tamanho da Ninhada de Vivíparos/efeitos dos fármacos , Locomoção/efeitos dos fármacos , Masculino , Síndrome dos Cabelos Torcidos/genética , Síndrome dos Cabelos Torcidos/metabolismo , Síndrome dos Cabelos Torcidos/fisiopatologia , Camundongos , Mutação , Especificidade de Órgãos , Fenótipo , Gravidez , Razão de Masculinidade
16.
Water Environ Res ; 84(12): 2086-9, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23342939

RESUMO

This study evaluated two chemical approaches for treatment of commingled cadmium-cyanide (Cd-CN) and zinc-nickel (Zn-Ni) wastewaters. The first approach, which involved application of sodium hypochlorite (NaOCl), focused on elimination of chelating substances. The second approach evaluated the use of sodium dimethyldithiocarbamate (DMDTC) to specifically target and precipitate regulated heavy metals. Results demonstrated that by maintaining a pH of 10.0 and an oxidation-reduction potential (ORP) value of +600 mV, NaOCl treatment was effective in eliminating all chelating substances. Cadmium, chromium, nickel, and zinc solution concentrations were reduced from 0.27, 4.44, 0.06, and 0.10 ppm to 0.16, 0.17, 0.03, and 0.06 ppm, respectively. Similarly, a 1% DMDTC solution reduced these same metal concentrations in commingled wastewater to 0.009, 1.142, 0.036, and 0.320 ppm. Increasing the DMDTC concentration to 2% improved the removal of all regulated heavy metals except zinc, the removal of which at high pH values is limited by its amphotericity.


Assuntos
Quelantes/farmacologia , Dimetilditiocarbamato/farmacologia , Resíduos Industriais , Metais Pesados/isolamento & purificação , Hipoclorito de Sódio/farmacologia , Águas Residuárias/análise , Purificação da Água/métodos , Cádmio/isolamento & purificação , Cianetos/química , Níquel/isolamento & purificação , Zinco/isolamento & purificação
17.
J Inorg Biochem ; 105(7): 991-9, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21569751

RESUMO

The antiproliferative properties and cellular impact of novel substitutionally inert rhodium(III) complexes of the types [Rh{(CH3)2 NCS2}2(pp)]Cl 3-5 (pp=5,6-Me2phen, dpq, dppz) and OC-6-23-[Rh(2-S-py)2(pp)]Cl 6 and 7 (2-S-py=pyridine-2-thiolate; pp=dpq, dppz) have been investigated for the adherent human cancer cell lines MCF-7 and HT-29 and for non-adherent Jurkat cells. Whereas CD and viscosity measurements indicate that the polypyridyl ligands of 4 and 5 intercalate into CT DNA, this is not the case for the analogous pyridine-2-thiolate complexes 6 and 7. Complexes 3-7 all exhibit a high antiproliferative activity towards MCF-7 and HT-29 cells, with IC(50) values in the range 0.055-0.285 µM. As established by online monitoring with a cell-based sensor chip, the highly cytostatic complex 6 (IC(50)=0.059 and 0.078 µM) invokes an immediate concentration-dependent reduction of MCF-7 cell respiration and a time-delayed decrease in cellular impedance, which can be ascribed to the induction of cell death. Annexin V/PI assays demonstrated that 6 also has a pronounced antiproliferative activity towards Jurkat cells and that it invokes extensive apoptosis and high concentrations of reactive oxygen species in these leukemia cells. The observation of a dose-dependent inhibition of the oxygen consumption of isolated mice mitochondria indicates the involvement of an intrinsic mitochondrial pathway in this process.


Assuntos
Antineoplásicos/farmacologia , Complexos de Coordenação/farmacologia , Ródio/química , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , DNA/química , Dimetilditiocarbamato/síntese química , Dimetilditiocarbamato/química , Dimetilditiocarbamato/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Análise de Fourier , Humanos , Técnicas In Vitro , Concentração Inibidora 50 , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Modelos Moleculares , Consumo de Oxigênio/efeitos dos fármacos , Temperatura de Transição
18.
J Hazard Mater ; 167(1-3): 589-96, 2009 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-19264406

RESUMO

N,N'-di (carboxymethyl) dithiocarbamate chelating resin (PSDC) was synthesized by anchoring the chelating agent of N,N'-di (carboxymethyl) dithiocarbamate to the chloromethylated PS-DVB (Cl-PS-DVB) matrix, as a new adsorbent for removing divalent heavy metal ions from waste-stream. The physicochemical structures of Cl-PS-DVB and PSDC were elaborately characterized using Fourier transform infrared spectroscopy (FT-IR), elemental analysis (EA), and were further morphologically characterized using BET and BJH methods. The adsorption performances of PSDC towards heavy metals such as Cu(II), Pb(II) and Ni(II) were systematically investigated, based upon which the adsorption mechanisms were deeply exploited. For the above target, the classic batch adsorption experiments were conducted to explore the kinetics and isotherms of the removal processes with pH-value, initial concentration, temperature, and contact time as the controlling parameters. The kinetic and isotherm data could be well elucidated with Lagergren-second-order equation and Langmuir model respectively. The strong affinity of PSDC toward these target soft acids could be well demonstrated with the electrostatic attraction and chelating interaction caused by IDA moiety and sulphur which were namely soft bases on the concept of hard and soft acids and bases (HASB). Thermodynamic parameters, involving DeltaH(o), DeltaS(o) and DeltaG(o) were also calculated from graphical interpretation of the experimental data. The standard heats of adsorption (DeltaH(o)) were found to be endothermic and the entropy change values (DeltaS(o)) were calculated to be positive for the adsorption of Cu(II), Pb(II) and Ni(II) ions onto the tested adsorbents. Negative values of DeltaG(o) indicated that adsorption processes for all tested metal ions onto PSDC were spontaneous.


Assuntos
Cátions Bivalentes/isolamento & purificação , Dimetilditiocarbamato/análogos & derivados , Metais Pesados/isolamento & purificação , Purificação da Água/métodos , Adsorção , Quelantes/química , Dimetilditiocarbamato/química , Concentração de Íons de Hidrogênio , Cinética , Resinas Sintéticas/química , Temperatura , Termodinâmica , Poluentes da Água/isolamento & purificação
19.
J Inorg Biochem ; 103(5): 774-82, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19250682

RESUMO

[RuCl(3).nH(2)O] and Na(trans-[RuCl(4)(DMSO)(2)]) were reacted with 1-pyrrolidinedithiocarbamate (PDT), its S-methyl ester (PDTM), and N,N-dimethylcarbamodithioic acid methyl ester (DMDTM) in water or methanol in order to obtain the corresponding Ru(III) derivatives. Once isolated and purified, the complexes were characterized by means of elemental analysis, conductivity measurements, FT-IR and (1)H NMR spectroscopy, ion electrospray mass spectrometry (ESI-MS), and thermal analyses. The crystal structure of mer-[Ru(DMDTM)(DMSO)Cl(3)] has been also determined by X-ray crystallography. In vitro cytotoxic activity of all the synthesized complexes was eventually evaluated on some selected human tumor cell lines.


Assuntos
Dimetilditiocarbamato/química , Pirrolidinas/química , Compostos de Rutênio/química , Compostos de Rutênio/farmacologia , Rutênio/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cristalografia por Raios X , Células HT29 , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Espectroscopia de Infravermelho com Transformada de Fourier
20.
J Biol Chem ; 283(50): 34696-703, 2008 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-18818210

RESUMO

The etiology of Parkinson disease (PD) is unclear but may involve environmental toxins such as pesticides leading to dysfunction of the ubiquitin proteasome system (UPS). Here, we measured the relative toxicity of ziram (a UPS inhibitor) and analogs to dopaminergic neurons and examined the mechanism of cell death. UPS (26 S) activity was measured in cell lines after exposure to ziram and related compounds. Dimethyl- and diethyldithiocarbamates including ziram were potent UPS inhibitors. Primary ventral mesencephalic cultures were exposed to ziram, and cell toxicity was assessed by staining for tyrosine hydroxylase (TH) and NeuN antigen. Ziram caused a preferential damage to TH+ neurons and elevated alpha-synuclein levels but did not increase aggregate formation. Mechanistically, ziram altered UPS function through interfering with the targeting of substrates by inhibiting ubiquitin E1 ligase. Sodium dimethyldithiocarbamate administered to mice for 2 weeks resulted in persistent motor deficits and a mild reduction in striatal TH staining but no nigral cell loss. These results demonstrate that ziram causes selective dopaminergic cell damage in vitro by inhibiting an important degradative pathway implicated in the etiology of PD. Chronic exposure to widely used dithiocarbamate fungicides may contribute to the development of PD, and elucidation of its mechanism would identify a new potential therapeutic target.


Assuntos
Dopamina/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ziram/farmacologia , Animais , Dimetilditiocarbamato/farmacologia , Inibidores Enzimáticos/farmacologia , Fungicidas Industriais/farmacologia , Humanos , Masculino , Camundongos , Neurônios/metabolismo , Doença de Parkinson , Ratos , Tirosina 3-Mono-Oxigenase/farmacologia
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