Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 205
Filtrar
Filtros adicionais











Intervalo de ano
1.
Nanoscale ; 11(11): 4767-4780, 2019 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-30816394

RESUMO

Nano-MoS2 has been extensively investigated in materials science and biomedicine. However, the effects of different methods of exposure on their translocation, biosafety, and biotransformation-related degradability remain unclear. In this study, we combined the advantages of synchrotron radiation (SR) X-ray absorption near-edge structure (XANES) and high-resolution single-cell SR transmission X-ray microscopy (SR-TXM) with traditional analytical techniques to investigate translocation, precise degraded species/ratio, and correlation between the degradation and toxicity levels of polyvinylpyrrolidone-modified 2H-phase MoS2 nanosheets (MoS2-PVP NSs). These NSs demonstrated different biodegradability levels in biomicroenvironments with H2O2, catalase, and human myeloperoxidase (hMPO) (H2O2 < catalase < hMPO). The effects of NSs and their biodegraded byproducts on cell viability and 3D translocation at the single-cell level were also assessed. Toxicity and translocation in mice via intravenous (i.v.), intraperitoneal (i.p.), and intragastric (i.g.) administration routes guided by fluorescence (FL) imaging were investigated within the tested dosage. After i.g. administration, NSs accumulated in the gastrointestinal organs and were excreted from feces within 48 h. After i.v. injection, NSs showed noticeable clearance due to their decreased accumulation in the liver and spleen within 30 days when compared with that in the i.p. group, which exhibited slight accumulation in the spleen. This work paves the way for understanding the biological behaviors of nano-MoS2 using SR techniques that provide more opportunities for future applications.


Assuntos
Dissulfetos/farmacocinética , Dissulfetos/toxicidade , Molibdênio/farmacocinética , Molibdênio/toxicidade , Nanoestruturas/toxicidade , Povidona/farmacocinética , Povidona/toxicidade , Animais , Biotransformação , Sobrevivência Celular/efeitos dos fármacos , Dissulfetos/administração & dosagem , Dissulfetos/química , Vias de Administração de Medicamentos , Masculino , Camundongos Endogâmicos BALB C , Molibdênio/administração & dosagem , Molibdênio/química , Nanomedicina , Nanoestruturas/administração & dosagem , Nanoestruturas/química , Povidona/administração & dosagem , Povidona/química , Distribuição Tecidual
2.
Mikrochim Acta ; 186(2): 58, 2019 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-30617543

RESUMO

The authors describe a fluorometric strategy for the determination of dopamine (DA). It is based on the use of aptamer-functionalized MoS2 quantum dots (QDs) and MoS2 nanosheets (NSs). The QDs and NSs were extensively characterized with regard to their physical and chemical properties using methods such as TEM, XRD, FT-IR, EDX and molecular spectroscopies. The aptamer against dopamine was labeled with QDs acting as the energy donor in an energy transfer system, while the NSs serve as the energy acceptor. Under the optimal conditions, the fluorescence (FL) intensity (best measured at excitation/emission peaks of 315/412 nm) increases with increasing DA concentration in the range from 0.1 nM to 1000 nM, with a lower detection limit of 45 pM. The method was successfully applied to the determination of DA in complex matrices. In our perception, the method has a wide scope in that it may be extended to other biomolecules for which respective aptamer are available. The QDs show excellent optical properties, good stability, low cytotoxicity, and may also be applied to fluorometric imaging of live cells. Graphical abstract A "turn-on" fluorometric aptasensor for the determination of dopamine (DA) was established based on aptamer-functionalized molybdenum disulfide quantum dots (MoS2 QDs) and MoS2 nanosheets. This assay exhibits high selectivity and sensitivity with a detection limit as low as 45 pM.


Assuntos
Aptâmeros de Nucleotídeos/química , DNA/química , Dissulfetos/química , Dopamina/análise , Transferência Ressonante de Energia de Fluorescência/métodos , Molibdênio/química , Pontos Quânticos/química , Sequência de Bases , Técnicas Biossensoriais/métodos , Dissulfetos/toxicidade , Células HeLa , Humanos , Limite de Detecção , Molibdênio/toxicidade , Pontos Quânticos/toxicidade
3.
ACS Appl Mater Interfaces ; 11(5): 4858-4866, 2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30628779

RESUMO

Molybdenum disulfide (MoS2) nanosheets have received considerable interest due to their superior physicochemical performances to graphene nanosheets. As the lateral size and layer thickness decrease, the formed MoS2 quantum dots (QDs) show more promise as photocatalysts, endowing them with potential antimicrobial properties under environmental conditions. However, studies on the antibacterial photodynamic therapy of MoS2 QDs have rarely been reported. Here, we show that MoS2 QDs more effectively promote the creation and separation of electron-hole pair than MoS2 nanosheets, resulting in the formation of multiple reactive oxygen species (ROS) under simulated solar light irradiation. As a result, photoexcited MoS2 QDs show remarkably enhanced antibacterial activity, and the ROS-mediated oxidative stress plays a dominant role in the antibacterial mechanism. The in vivo experiments showed that MoS2 QDs are efficacious in wound healing under simulated solar light irradiation and exert protective effects on normal tissues, suggesting good biocompatibility properties. Our findings provide a full description of the photochemical behavior of MoS2 QDs and the resulting antibacterial activity, which might advance the development of MoS2-based nanomaterials as photodynamic antibacterial agents under environmental conditions.


Assuntos
Antibacterianos , Dissulfetos , Molibdênio , Pontos Quânticos , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antibacterianos/efeitos da radiação , Antibacterianos/toxicidade , Bactérias/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dissulfetos/química , Dissulfetos/farmacologia , Dissulfetos/toxicidade , Células Endoteliais da Veia Umbilical Humana , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Molibdênio/química , Molibdênio/farmacologia , Molibdênio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Processos Fotoquímicos , Pontos Quânticos/química , Pontos Quânticos/efeitos da radiação , Pontos Quânticos/toxicidade , Espécies Reativas de Oxigênio , Infecção dos Ferimentos
4.
Chemosphere ; 201: 780-789, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29550572

RESUMO

The aim of this study was to examine the effect of chromium(III) and iron(III) and molybdenum(III) and nickel(II) and their combinations on cyto-, genotoxicity and mutagenicity in BALB/3T3 and HepG2 cells. The results obtained from cytotoxicity assays indicate that there are differences between BALB/3T3 and HepG2 cell lines in their sensitivity to chromium chloride, iron chloride, molybdenum trioxide and nickel chloride. The statistically significant increase of DNA damage of all used microelements in both cell lines was observed. The micronucleus assay performed with the use of all concentrations shows statistically significant induction of chromosomal aberrations in all tested microelements in both cell lines. Moreover, treated cells display characteristic apoptosis in comparison to control cells. In all tested microelements, the increase of number of reverse mutations was observed with and without metabolic activation. Additions of Cr(III) at 200 µM plus Fe(III) at 1000 µM showed synergistic effect in decrease of cell viability and increase of comets, micronuclei and number of revertants in both cell lines. In case of Cr(III) at 200 µM plus Mo(III) at 1000 µM, a protective effect of chromium against molybdenum at 1000 µM toxicity in both cell lines (assessed by MTT, LDH and NRU, comet, micronucleus and Ames assays) was observed. The protective effect of Cr(III) in decrease of cell viability was observed in pair of Cr(III) at 200 µM and Ni(II) at 1000 µM in BALB/3T3 and HepG2 cell lines assessed by MTT, LDH and NRU, comet, micronucleus and Ames assays.


Assuntos
Cloretos/toxicidade , Compostos de Cromo/toxicidade , Dano ao DNA , Compostos Férricos/toxicidade , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Molibdênio/toxicidade , Níquel/toxicidade , Óxidos/toxicidade , Animais , Células 3T3 BALB , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Interações de Medicamentos , Células Hep G2 , Humanos , Camundongos , Salmonella typhimurium/efeitos dos fármacos
5.
Chemosphere ; 193: 574-580, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29169133

RESUMO

Cadmium (Cd) and high Molybdenum (Mo) can lead to adverse reactions on animals, but the co-induced toxicity of Mo and Cd to liver in ducks was not well understood. To investigate the co-induced toxic effects of Mo combined with Cd on mitochondrial oxidative stress and apoptosis in duck livers. 240 healthy 11-day-old ducks were randomly divided into 6 groups (control, LMo group, HMo group, Cd group, LMoCd group and HMoCd group). After being treated for 30, 60, 90 and 120 days, liver mitochondrial antioxidant indexes, ceruloplasmin (CP), metallothionein (MT), Bak-1 and Caspase-3 genes mRNA expression levels, and ultrastructural changes were evaluated. The results showed that total antioxidative capacity (T-AOC), catalase (CAT), superoxide dismutase (SOD) and xanthine oxidase (XOD) activities in experimental groups were decreased, whereas malondialdehyde (MDA) content and nitric oxide synthase (NOS) activity were increased compared with control group, and these changes of co-treated groups were more obvious in the later period of the experiment. The mRNA expression levels of CP, Bak-1 and Caspase-3 were up-regulated in experimental groups compared with control group and showed significant difference between co-treated groups and single treated groups. The mRNA expression level of MT in Cd group was higher than that in co-treated groups. Additionally, ultrastructural changes showed karyopyknosis, mitochondrial swelling, vacuolation and disruption of mitochondrial cristae in co-treated groups. Taken together, it was suggested that dietary Mo and Cd might lead to mitochondrial oxidative stress and apoptosis in duck livers, and it showed a possible synergistic relationship between the two elements.


Assuntos
Cádmio/toxicidade , Patos/fisiologia , Fígado/metabolismo , Molibdênio/toxicidade , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Cádmio/metabolismo , Caspase 3/metabolismo , Catalase/metabolismo , Patos/metabolismo , Masculino , Malondialdeído/metabolismo , Metalotioneína/metabolismo , Mitocôndrias/metabolismo , Molibdênio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , RNA Mensageiro/metabolismo , Regulação para Cima
6.
Salud Publica Mex ; 59(5): 548-555, 2017 Sep-Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29267652

RESUMO

OBJECTIVE: This study determined the main dietary sources of urinary molybdenum (Mo) concentrations in a sample of 124 pregnant women in Mexico. MATERIALS AND METHODS: Dietary data was collected during pregnancy, through a semi-qualitative food frequency questionnaire, with information of 84 foods. Urine Mo levels were determined by atomic absorption spectrometry, for at least two trimesters of pregnancy. The associations with Mo levels were estimated by generalized mixed effect regression models. RESULTS: Between 5.8 to 12.7% of the samples were above the 95th percentile of urinary Mo distribution reported by National Health and Nutrition Examination Survey (NHANES) 2009-2010 for women (151 µg/L and 148 µg/g creatinine). After bootstrap resampling was conducted, women with high-consumption of hot peppers (ß=1.34µg/g; 95% CI: 1.00-1.80; p= 0.05) had marginally higher urinary Mo concentration levels, creatinine adjusted, compared to women with low-consumption. CONCLUSION.: Hot chili pepper consumption may contribute to body burden Mo levels in this population.


Assuntos
Dieta , Molibdênio/urina , Adulto , Capsicum/química , Comportamento Alimentar , Feminino , Humanos , México , Molibdênio/farmacocinética , Molibdênio/toxicidade , Projetos Piloto , Gravidez , Trimestres da Gravidez/urina , Efeitos Tardios da Exposição Pré-Natal , Fatores Socioeconômicos , Espectrofotometria Atômica , Adulto Jovem
7.
Int J Nanomedicine ; 12: 5387-5397, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28794630

RESUMO

Wear particle-induced inflammatory osteolysis is the primary cause of aseptic loosening, which is the most common reason for total hip arthroplasty (THA) failure in the med- and long term. Recent studies have suggested an important role of gut microbiota (GM) in modulating the host metabolism and immune system, leading to alterations in bone mass. Probiotic bacteria administered in adequate amounts can alter the composition of GM and confer health benefits to the host. Given the inflammatory osteolysis that occurs in wear debris-induced prosthesis loosening, we examined whether the probiotic Lactobacillus casei could reduce osteolysis in a mouse calvarial resorption model. In this study, L. casei markedly protected mice from CoCrMo particles (CoPs)-induced osteolysis. Osteoclast gene markers and the number of osteoclasts were significantly decreased in L. casei-treated mice. Probiotic treatment decreased the M1-like macrophage phenotype indicated by downregulation of tumor necrosis factor α (TNF-α), interleukin (IL)-6 and inducible nitric oxide synthase (iNOS) and increased the M2-like macrophage phenotype indicated by upregulation of IL-4, IL-10 and arginase. Collectively, these results indicated that the L. casei treatment modulated the immune status and suppressed wear particle-induced osteolysis in vivo. Thus, probiotic treatment may represent a potential preventive and therapeutic approach to reduced wear debris-induced osteolysis.


Assuntos
Lactobacillus casei , Osteólise/prevenção & controle , Probióticos/farmacologia , Animais , Reabsorção Óssea/terapia , Cromo/toxicidade , Cobalto/toxicidade , Modelos Animais de Doenças , Regulação da Expressão Gênica , Interleucina-10/metabolismo , Interleucina-4/metabolismo , Macrófagos/metabolismo , Camundongos , Molibdênio/toxicidade , Óxido Nítrico Sintase Tipo II/metabolismo , Osteoclastos/citologia , Osteoclastos/fisiologia , Osteólise/induzido quimicamente , Fator de Necrose Tumoral alfa/metabolismo
8.
Environ Sci Technol ; 51(18): 10834-10842, 2017 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-28841301

RESUMO

Sheetlike molybdenum disulfide (MoS2) and boron nitride (BN) nanomaterials have attracted attention in the past few years due to their unique material properties. However, information on adverse effects and their underlying mechanisms for sheetlike MoS2 and BN nanomaterials is rare. In this study, cytotoxicities of sheetlike MoS2 and BN nanomaterials on human hepatoma HepG2 cells were systematically investigated at different toxic end points. Results showed that MoS2 and BN nanomaterials decreased cell viability at 30 µg/mL and induced adverse effects on intracellular ROS generation (≥2 µg/mL), mitochondrial depolarization (≥4 µg/mL), and membrane integrity (≥8 µg/mL for MoS2 and ≥2 µg/mL for BN). Furthermore, this study first found that low exposure concentrations (0.2-2 µg/mL) of MoS2 and BN nanomaterials could increase plasma membrane fluidity and inhibit transmembrane ATP binding cassette (ABC) efflux transporter activity, which make both nanomaterials act as a chemosensitizer (increasing arsenic toxicity). Damage to plasma membrane and release of soluble Mo or B species might be two reasons that both nanomaterials inhibit efflux pump activities. This study provides a systematic understanding of the cytotoxicity of sheetlike MoS2 and BN nanomaterials at different exposure levels, which is important for their safe use.


Assuntos
Compostos de Boro/toxicidade , Dissulfetos/toxicidade , Molibdênio/toxicidade , Nanoestruturas/toxicidade , Transportadores de Cassetes de Ligação de ATP/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Células Hep G2 , Humanos
9.
Sci Total Environ ; 609: 420-428, 2017 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-28755592

RESUMO

The freshwater and marine long-term ecotoxicity datasets used in the European REACH registration dossiers for molybdenum and molybdenum compounds resulted in the derivation of a HC5,50%,freshwater (38.2mgMo/L) and HC5,50%,marine (5.70mgMo/L) by means of the statistical extrapolation method. Both datasets, however, did not meet the US-EPA information requirements for deriving Final Chronic Values (FCV) that were based on chronic data. US-EPA compliance was achieved by generating chronic no-effect data for the freshwater benthic amphipod Hyalella azteca and the marine inland silverside fish Menidia beryllina, using sodium molybdate dihydrate as test substance. A 42d-EC10 of 44.6mgMo/L for reproduction was determined in a water-only exposure with H. azteca. For M. beryllina, a 37d-NOEC of 139mg mMo/L for standard length and blotted wet weight was found. Other endpoints (e.g., survival, hatching success) proved to be less sensitive. Data were added to the existing chronic toxicity datasets, together with new long-term no-effect values that were identified in open literature for brown trout Salmo trutta, the marine alga Isochrysis galbana, the marine snail Nassarius dorsatus and the marine barnacle Amphibalanus amphitrite. The updated data sets resulted in a freshwater and marine HC5,50% of 35.7 and 6.85mgMo/L, respectively. The same data sets were also used for the determination of US-EPA FCVs, where the FVCfreshwater was 36.1mg/L, and the FCVmarine was 3.85mgMo/L. As the Final Plant Values for both aquatic environments were higher than their respective FCVs, the Criterion Continuous Concentration (CCC) for molybdenum is equal to the FCV.


Assuntos
Organismos Aquáticos/efeitos dos fármacos , Exposição Ambiental/efeitos adversos , Molibdênio/toxicidade , Poluentes Químicos da Água/toxicidade , Anfípodes/efeitos dos fármacos , Animais , Ecotoxicologia , Europa (Continente) , Peixes , Água Doce , Estados Unidos
10.
Ecotoxicol Environ Saf ; 145: 24-31, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28692912

RESUMO

Molybdenum (Mo) is an essential element for human beings and animals; however, high dietary intake of Mo can lead to adverse reactions. Cadmium (Cd) is one of the major transitional metals which has toxic effects in animals. To investigate the co-induced toxic effects of Mo and Cd on oxidative damage and kidney apoptosis in duck, 120 ducks were randomly divided into control group and 5 treatment groups which were treated with a commercial diet containing different dosages of Mo and Cd. Kidney samples were collected on the 60th and 120th days to determine the mRNA expression levels of ceruloplasmin (CP), metallothionein (MT), Bak-1, and Caspase-3 by quantitative RT-PCR. Additionally, we also determined the antioxidant activity indexes and contents of Mo, Cd, copper (Cu), iron (Fe), zinc (Zn), and selenium (Se) in serum. Meanwhile, ultrastructural changes of the kidney were observed. The results showed that glutathione reductase (GR) activity and CP level in serum were decreased in combination groups. In addition, the antioxidant indexes were decreased in co-treated groups compared with single treated groups. The mRNA expression levels of Bak-1 and Caspase-3 increased in co-treated groups. The mRNA expression level of CP in high-dose combination group was downregulated, while the mRNA expression of MT was upregulated except for low-dose Mo group. Additionally, in the later period the content of Cu in serum decreased in joint groups while the contents of Mo and Cd increased. In addition, ultrastructural changes showed mitochondrial crest fracture, swelling, deformed nuclei, and karyopyknosis in co-treated groups. Taken together, it was suggested that dietary Mo and Cd might lead to oxidative stress, kidney apoptosis and disturb homeostasis of trace elements in duck, and it showed a possible synergistic relationship between the two elements.


Assuntos
Apoptose/efeitos dos fármacos , Cádmio/toxicidade , Patos/metabolismo , Monitoramento Ambiental/métodos , Poluentes Ambientais/toxicidade , Rim/efeitos dos fármacos , Molibdênio/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Relação Dose-Resposta a Droga , Rim/metabolismo , Rim/ultraestrutura , Oligoelementos/toxicidade
11.
Nanotoxicology ; 11(6): 781-793, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28714804

RESUMO

Single-layer molybdenum disulfide (SLMoS2) is a novel kind of 2D nanosheet that has attracted great attention regarding its use in biosensors, drug delivery, tissue engineering, and therapy. However, our results demonstrated that SLMoS2 accelerated proliferation and promoted myogenic differentiation and epithelial-mesenchymal transition (EMT) in human embryonic lung fibroblasts (HELFs). The abnormal proliferation and differentiation of HELFs contribute to idiopathic pulmonary fibrosis. Specifically, SLMoS2 significantly stimulated the expression of myofibroblast- and mesenchymal-associated genes and proteins. The Akt-mTOR-p70S6K signaling pathway plays a critical role in the acceleration of proliferation and promotion of myogenic differentiation and EMT in HELFs induced by SLMoS2. After cell uptake, SLMoS2 was primarily located in the cytoplasm and the perinuclear region and activated Akt-dependent signaling due to the generation of reactive oxygen species (ROS). Moreover, bovine serum albumin (BSA) binding markedly inhibited the cellular uptake of SLMoS2 and the production of intracellular ROS due to an increased thickness and reduced adhesion of HELFs. BSA binding also mitigated the SLMoS2-activated phosphorylation of Akt-dependent signaling pathways. This study is the first to illustrate the induction of cellular proliferation and differentiation by SLMoS2 and the related mediation by proteins through Akt-mTOR-p70S6K signaling pathway.


Assuntos
Proliferação de Células/efeitos dos fármacos , Dissulfetos/toxicidade , Molibdênio/toxicidade , Nanoestruturas/toxicidade , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Fosforilação
12.
J Exp Clin Cancer Res ; 36(1): 73, 2017 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-28577555

RESUMO

BACKGROUND: Epidemiologic data in volcanic areas suggest that environmental factors might be involved in the increase of thyroid cancer (TC) incidence. Recent reports indicate that several heavy metals and metalloids are increased in volcanic areas. This study aims to evaluate the combined effect of three of these elements Boron (B), Cadmium (Cd), and Molybdenum (Mo) - all increased in the volcanic area of Mt. Etna, in Italy - on thyroid tumorigenesis in the rat. METHODS: Female Wistar rats prone to develop thyroid tumors by low-iodine diet and methimazole treatment received ad libitum drinking water supplemented with B, Cd, and Mo at concentrations in the range found in the urine samples of residents of the volcanic area. At 5 and 10 months animals were euthanized, and their thyroid analysed. Statistical analysis was performed with a 2-way unpaired t-test. RESULTS: No toxic effect of the three elements on the growth of the animals was observed. A significant increase of histological features of transformation was observed in thyroid follicular cells of rats treated with B, Cd, and Mo compared with those of control group. These abnormalities were associated with decreased iodine content in the thyroid. CONCLUSIONS: This study provides the evidence that slightly increased environmental concentrations of B, Cd, and Mo can accelerate the appearance of transformation marks in the thyroid gland of hypothyroid rats.


Assuntos
Boro/toxicidade , Cádmio/toxicidade , Transformação Celular Neoplásica/induzido quimicamente , Molibdênio/toxicidade , Neoplasias da Glândula Tireoide/induzido quimicamente , Animais , Boro/administração & dosagem , Cádmio/administração & dosagem , Transformação Celular Neoplásica/patologia , Feminino , Molibdênio/administração & dosagem , Ratos , Ratos Wistar , Neoplasias da Glândula Tireoide/patologia
13.
Bull Environ Contam Toxicol ; 98(6): 747-752, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28396975

RESUMO

Limited data are available describing the aquatic toxicity of molybdenum in freshwater environments, making it difficult to assess the aquatic risk to freshwater organisms. In order to increase available information on the aquatic toxicity of molybdenum, a 96-h LC50 test with the oligochaete Tubifex tubifex and an 85-day development test using brown trout, Salmo trutta, were conducted. The T. tubifex test resulted in an LC50 value of 2782 mg/L. No adverse effects were observed on brown trout survival or length in the concentrations tested, however an IC10 value for growth (wet weight) was determined to be 202 mg/L. Whole body fish tissue concentrations for molybdenum increased in all treatment concentrations tested, although bioconcentration factors decreased at greater exposure concentrations, and ranged from 0.13 at an exposure concentration of 20 mg/L to 0.04 at an exposure of 1247 mg/L. A body burden of 26.0 mg/kg was associated with reduced wet weight.


Assuntos
Monitoramento Ambiental , Molibdênio/toxicidade , Oligoquetos/fisiologia , Truta/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Oligoquetos/efeitos dos fármacos
14.
Plant Physiol Biochem ; 115: 200-211, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28376412

RESUMO

Molybdenum (Mo)-an essential element of plants-is involved in nitrogen (N) metabolism. Plants tend to accumulate more nitrate and show lower nitrogen use efficiency (NUE) under Mo-deficient conditions. Improving NUE in fruits reduces the negative effect of large applications of chemical fertilizer, but the mechanisms underlying how Mo enhances NUE remain unclear. We cultivated strawberry seedlings sprayed with 0, 67.5, 135, 168.75, or 202.5 g Mo·ha-1 in a non-soil culture system. The Mo concentration in every plant tissue analyzed increased gradually as Mo application level rose. Mo application affected iron, copper, and selenium adsorption in roots. Seedlings sprayed with 135 g Mo·ha-1 had a higher [15N] shoot:root (S:R) ratio, and 15NUE, and produced higher molybdate transporter type 1 (MOT1) expression levels in the roots and leaves. Seedlings sprayed with 135 g Mo·ha-1 also had relatively high nitrogen metabolic enzyme activities and up-regulated transcript levels of nitrate uptake genes (NRT1.1; NRT2.1) and nitrate-responsive genes. Furthermore, there was a significantly lower NO3- concentration in the leaves and roots, a higher NH4+ concentration in leaves, and a higher glutamine/glutamate (Gln/Glu) concentration at 135 g Mo·ha-1. Seedlings sprayed with 202.5 g Mo·ha-1 showed the opposite trend. Taken together, these results suggest that a 135 g Mo·ha-1 application was optimal because it enhanced NO3- transport from the roots to the shoots and increased NUE by mediating nitrogen metabolic enzyme activities, nitrate transport, and nitrate assimilation gene activities.


Assuntos
Fragaria/efeitos dos fármacos , Molibdênio/toxicidade , Nitratos/metabolismo , Plântula/efeitos dos fármacos , Cobre/metabolismo , Fragaria/metabolismo , Ferro/metabolismo , Isótopos de Nitrogênio , Plântula/metabolismo , Selênio/metabolismo
15.
Regul Toxicol Pharmacol ; 86: 279-291, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28342846

RESUMO

The potential of molybdenum substances to cause genotoxic effects has been studied previously. However, a review of existing in vitro data, including an assessment of relevance and reliability, has shown that inconsistent results have been observed in the past. To resolve the inconsistencies, new studies were performed with the highly soluble sodium molybdate dihydrate according to OECD test guidelines. In a bacterial reverse mutation assay sodium molybdate dihydrate did not induce reverse mutations in five strains of Salmonella typhimurium. No mutagenic or clastogenic effect was observed at the tk locus of L5178Y mouse lymphoma cells. In a micronucleus test in cultured human peripheral blood lymphocytes no clastogenic or aneugenic effects were seen. These results can be read across to other inorganic molybdenum substances, that all release the molybdate ion [MoO4]2- under physiological conditions as the only toxicologically relevant species. In summary, a weight of evidence assessment of all available in vitro data shows no evidence of genotoxicity of molybdenum substances.


Assuntos
Testes para Micronúcleos , Molibdênio/toxicidade , Testes de Mutagenicidade , Salmonella typhimurium/efeitos dos fármacos , Animais , Humanos , Leucemia L5178 , Camundongos , Mutagênicos , Reprodutibilidade dos Testes , Salmonella typhimurium/genética
16.
Environ Pollut ; 224: 606-614, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28258860

RESUMO

In this study, the phototoxicity of cadmium sulfide (CdS), molybdenum disulfide (MoS2), and tungsten disulfide (WS2) nanoparticles (NPs) toward Escherichia coli (E. coli) under UV irradiation (365 nm) was investigated. At the same mass concentration of NPs, the toxicity of three NPs decreased in the order of CdS > MoS2 > WS2. For example, the death rates of E. coli exposed to 50 mg/L CdS, MoS2, and WS2 were 96.7%, 38.5%, and 31.2%, respectively. Transmission electron microscope and laser scanning confocal microscope images of E. coli exposed to three NPs showed the damage of cell walls and release of intracellular components. The CdS-treated cell wall was more extensively damaged than those of MoS2-treated and WS2-treated bacteria. WS2 and MoS2 generated superoxide radical (O2-), singlet oxygen (1O2), and hydroxyl radical under UV irradiation, CdS produced only O2- and 1O2. CdS and WS2 released ions under UV irradiation, while MoS2 did not. Reactive oxygen species (ROS) generation and toxic ion release jointly resulted in the antibacterial activities of CdS and WS2. ROS generation was the dominant toxic mechanism of MoS2 toward the bacteria. This study highlighted the importance of considering the hazardous effect of sulfide NPs after their release into natural waters under light irradiation condition.


Assuntos
Cádmio/toxicidade , Escherichia coli/efeitos dos fármacos , Molibdênio/toxicidade , Nanopartículas/toxicidade , Sulfetos/toxicidade , Tungstênio/toxicidade , Raios Ultravioleta , Dermatite Fototóxica , Luz
17.
Mol Immunol ; 85: 27-34, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28208071

RESUMO

Wear particle-induced osteolysis and bone resorption have been identified as critical factors of implant failure and total joint revision, in which nuclear factor kappa B (NF-κB) signaling and chronic inflammation have been shown to play key roles. Although anthocyanin is known to have anti-inflammatory function via blocking NF-κB pathway, it is still unclear whether anthocyanin has a protective effect on particle-induced osteolysis. In the present study, we aimed to investigate the detailed effects and the underlying mechanism of anthocyanin on CoCrMo particle-induced osteolysis in a mouse calvavial model. One hundred and twelve male BALB/c mice were divided randomly into four groups: sham group (sham operation and injection with PBS), vehicle group (CoCrMo particle treatment and injection with PBS), low-dose anthocyanin group (CoCrMo particle treatment and injecting anthocyanin with 0.1mg/g/day), and high-dose anthocyanin group (CoCrMo particle treatment and injecting anthocyanin with 0.4mg/g/day). Mice were sacrificed after two weeks, harvesting the calvariae tissue for in depth analysis by micro-CT, histomorphometry, immunohistochemical and molecular biology analysis. As expected, anthocyanin markedly inhibited CoCrMo particle-induced inflammatory infiltration and decreased bone loss in vivo. Anthocyanin also reversed the increase in the ratio of receptor activator of nuclear factor kappa B ligand (RANKL)/osteoproteger (OPG) and suppressed osteoclast formation in CoCrMo particle-stimulated calvaria. Additionally, anthocyanin significantly reduced the expression and secretion of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß) and interleukin-6 (IL-6) in the calvaria of CoCrMo-stimulated mice. Furthermore, we confirmed that anthocyanin attenuated osteolysis by blocking NF-κB pathway via inhibiting inhibitor of nuclear factor kappa-B kinase α/ß (IKKα/ß) phosphorylation. In conclusion, our study demonstrated that anthocyanin can protect against CoCrMo particle-induced inflammatory osteolysis via inhibiting the IKKα/ß-NF-κB pathway, and have a potential therapeutic effect on the treatment of wear particle-induced osteolysis.


Assuntos
Antocianinas/farmacologia , Cromo/toxicidade , Cobalto/toxicidade , Molibdênio/toxicidade , Osteólise/induzido quimicamente , Animais , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Quinase I-kappa B/metabolismo , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos BALB C , NF-kappa B/metabolismo , Osteólise/metabolismo , Osteólise/patologia , Distribuição Aleatória , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais/efeitos dos fármacos , Crânio/efeitos dos fármacos , Crânio/patologia , Microtomografia por Raio-X
18.
J Colloid Interface Sci ; 496: 261-266, 2017 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-28235720

RESUMO

Sandwich-like molybdenum sulfide/mesoporous organosilica nanosheets (denoted as MoS2@MOS) have been prepared for the first time via direct growth of ethane-bridged mesostructured organosilica on MoS2 nanosheets by using cetyltrimethylammonium bromide (CTAB) as structure directing agent. The obtained MoS2@MOS nanosheets possess well-defined sandwich-like structure, high surface area (∼920cm2/g), uniform pore size (∼4.2nm), large pore volume (∼1.41cm3g-1). In vitro cytotoxicity assessments demonstrate that the MoS2@MOS nanosheets have excellent biocompatibility. Owing to the encapsulation of the MoS2, the obtained MoS2@MOS nanosheets have photo-thermal conversion capability and photo-thermally controlled drug release property. These properties make the MoS2@MOS nanosheets promising for biomedical applications.


Assuntos
Dissulfetos/química , Molibdênio/química , Nanoestruturas/química , Compostos de Organossilício/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Materiais Biocompatíveis/química , Sobrevivência Celular/efeitos dos fármacos , Cetrimônio , Compostos de Cetrimônio/química , Dissulfetos/toxicidade , Doxorrubicina/química , Doxorrubicina/farmacologia , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Temperatura Alta , Humanos , Lasers , Células MCF-7 , Molibdênio/toxicidade , Nanoestruturas/efeitos da radiação , Nanoestruturas/toxicidade , Compostos de Organossilício/toxicidade , Tamanho da Partícula , Porosidade , Propriedades de Superfície
19.
J Vet Sci ; 18(2): 193-200, 2017 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-27297413

RESUMO

To investigate the effects of molybdenum (Mo) and/or cadmium (Cd) on antioxidant function and the apoptosis-related genes in duck spleens. Sixty healthy 11-day-old ducks were randomly divided into six groups of 10 ducks (control, low Mo group, high Mo, Cd, low Mo + Cd, and high Mo + Cd groups). All were fed a basal diet containing low or high dietary doses of Mo and/or Cd. Relative spleen weight, antioxidant indices, apoptosis-related gene mRNA expression levels, and ultrastructural changes were evaluated after 120 days. The results showed that the relative spleen weight decreased significantly in the high Mo + Cd treatment group which compared with control group. Malondialdehyde levels increased and xanthine oxidase and catalase activities decreased in the Mo and/or Cd groups compared with levels in the control group. Bak-1 and Caspase-3 expressions were upregulated in the high Mo + Cd group, while Bcl-2 was downregulated. In addition, mitochondrial crest fracture, swelling, vacuolation, deformed nuclei, and karyopyknosis in both Mo + Cd treated groups were more severe than in the other groups. The results suggest that Mo and/or Cd can induce oxidative stress and apoptosis of spleen via effects on the mitochondrial intrinsic pathway. Moreover, the results indicate the two elements have a possible synergistic relationship.


Assuntos
Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Cádmio/toxicidade , Molibdênio/toxicidade , Baço/efeitos dos fármacos , Animais , Antioxidantes/fisiologia , Catalase/metabolismo , Relação Dose-Resposta a Droga , Patos/metabolismo , Expressão Gênica/efeitos dos fármacos , Malondialdeído/metabolismo , Microscopia Eletrônica de Transmissão/veterinária , Tamanho do Órgão/efeitos dos fármacos , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Baço/ultraestrutura , Xantina Oxidase/metabolismo
20.
Biol Trace Elem Res ; 175(2): 449-457, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27392954

RESUMO

Cadmium (Cd) and high molybdenum (Mo) can lead to adverse reactions on animals, but the coinduced toxicity of Mo and Cd to bone in ducks was not well understood. The objective of this study was to investigate the changes in trace elements' contents and morphology in bones of duck exposed to Mo or/and Cd. One hundred twenty healthy 11-day-old male ducks were randomly divided into six groups and treated with commercial diet containing Cd or/and Mo. On the 60th and 120th days, the blood, excretion, and metatarsals were collected to determine alkaline phosphatase (ALP) activity and the contents of Mo, Cd, calcium (Ca), phosphorus (P), copper (Cu), iron (Fe), zine (Zn), and selenium (Se). In addition, metatarsals were subjected to histopathological analysis with the optical microscope and radiography. The results indicated that Mo and Cd contents significantly increased while Ca, P, Cu, and Se contents remarkably decreased in metatarsals in coexposure groups (P < 0.01). Contents of Fe and Zn in metatarsals had no significant difference among groups (P > 0.05). Ca content in serum had no significant difference among experimental groups (P > 0.05), but P content was significantly decreased in HMo and HMo + Cd groups (P < 0.05). Contents of Ca and P in excretion and ALP activity were significantly increased in coinduced groups (P < 0.05). Furthermore, osteoporotic lesions, less and thinner trabecular bone were observed in combination groups. The findings suggested that dietary of Cd or/and Mo could lead to bone damages in ducks via disturbing the balance of Ca and P in body and homeostasis of Cu, Fe, Zn, and Se in bones; moreover, the two elements showed a possible synergistic relationship.


Assuntos
Cádmio/toxicidade , Ossos do Metatarso/metabolismo , Molibdênio/toxicidade , Oligoelementos/metabolismo , Animais , Patos , Masculino , Ossos do Metatarso/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA