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1.
Nutrients ; 13(8)2021 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-34444705

RESUMO

Exposure of individuals to radioactive material as a result of ingestion of contaminated food and water is an increasing public health concern. Unfortunately, there are limited treatment modalities for dealing with these types of potentially toxic exposures. Recent research suggests that many plant-based nutraceuticals may possess metal-binding properties. This preliminary study investigated the ability of genistein, curcumin, quercetin, and lentinan to bind metals considered internal contamination risks, namely cesium, uranium, cobalt, and strontium, in a variety of matrices. The efficacy of these nutraceuticals in protecting cultured cells from metal-induced toxicity was also explored. Results showed that none of the compounds bound cesium or strontium. However, genistein, curcumin, and quercetin could bind uranium. Curcumin and quercetin also bound cobalt and could also protect cultured cells from metal-induced cytotoxicity. Lentinan did not bind any of the metals tested. Metal binding was also pH dependent, with no binding observed at lower pH values. This project showed that nutraceuticals could function as chelators for metals considered internal radionuclide contamination hazards. Further investigations are required in order to determine whether these compounds will become a new nontoxic arsenal of pharmaceutical compounds with which to treat radionuclide contamination.


Assuntos
Quelantes/farmacologia , Exposição Dietética/prevenção & controle , Suplementos Nutricionais/análise , Elementos Radioativos/toxicidade , Extratos Vegetais/farmacologia , Técnicas de Cultura de Células , Césio/toxicidade , Cobalto/toxicidade , Curcumina/farmacologia , Exposição Dietética/efeitos adversos , Contaminação Radioativa de Alimentos/análise , Contaminação Radioativa de Alimentos/prevenção & controle , Genisteína/farmacologia , Humanos , Lentinano/farmacologia , Quercetina/farmacologia , Estrôncio/toxicidade , Urânio/toxicidade
2.
Ecotoxicol Environ Saf ; 197: 110620, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32311615

RESUMO

The aim of this study was to evaluate the ecotoxic effect of high concentration cesium (Cs) exposure on plant root growth and its toxicological mechanism. The radicle of broad bean (Vicia faba) was selected as experimental material. The cytotoxic and genotoxic effects of plants exposed to different Cs levels (0.19-1.5 mM) for 48 h were evaluated using scanning electron microscopy (SEM), X-ray fluorescence (XRF) analysis, single-cell gel electrophoresis (SCGE) and random amplified polymorphic DNA (RAPD) assays. The results showed that radicle elongation decreased clearly after 48 h of exposure treatment with different concentrations of Cs solution. The root cell structure was obviously damaged in the Cs treatment groups (0.19-1.5 mM). At a Cs concentration of 1.5 mM, the percentages of viable non-apoptotic cells, viable apoptotic cells, non-viable apoptotic cells, and non-viable cells were 40.09%, 20.67%, 28.73%, and 10.52%, respectively. SCGE showed DNA damage in radicle cells 48 h after Cs exposure. Compared with the control group, the percentage of tail DNA in Cs exposed group (0.38-1.5 mM) increased by 0.56-1.12 times (P < 0.05). RAPD results showed that the genomic stability of V. faba radicles decreased by 4.44%-15.56%. This study confirmed that high concentration Cs exposure had cytotoxicity and genotoxicity effects on plants.


Assuntos
Césio/toxicidade , Dano ao DNA , Vicia faba/efeitos dos fármacos , Apoptose , Citotoxinas/toxicidade , Eletroforese , Instabilidade Genômica/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Técnica de Amplificação ao Acaso de DNA Polimórfico , Análise de Célula Única , Vicia faba/genética
3.
Ecotoxicol Environ Saf ; 184: 109625, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31518824

RESUMO

Stable isotopes of cesium (Cs) and strontium (Sr) as well as their radioactive isotopes are of serious environmental concern. The pollution of the biosphere, particularly soil and water has received considerable attention for removal of these contaminants in recent years. Arabidopsis halleri (A. halleri) is a hyperaccumulator plant species able to take up large amounts of several metals into its above ground organs without showing significant signs of toxicity. Therefore, we investigated responses, metal accumulation and element distribution in roots and leaves of A. halleri after treatment with stable Cs and Sr. Plants were hydroponically grown in different concentrations of cesium sulfate (between 0.002 and 20 mM) and strontium nitrate (between 0.001 and 100 mM). Uptake of Cs and Sr into leaves was analyzed from extracts by inductively coupled plasma mass spectrometry (ICP-MS). Although internal concentration of Cs and Sr increased with rising external concentrations, the amount of accumulated metal in relation to available metal decreased. Therefore, the potential of the plant to effectively transfer metals from growth medium to leaves occurred at low and moderate concentrations, whereas after that when the concentration of metal increased further the transfer factors were decreased. A. halleri accumulated Sr more efficiently than Cs. The transfer factors were higher for Sr (up to 184) than for Cs (up to 16). The results indicate positive correlation of Cs and Sr accumulation to K and Ca transport to leaves. The toxicity of Cs and Sr was assessed by measuring photosynthetic efficiency and growth parameters. In leaves, Cs and Sr affected the chlorophyll fluorescence at their low and high concentrations. Significant reduction of plant growth (dry weight of roots and leaves) was observed at Sr concentrations >0.01 mM. Cs-treated plants exhibited only decreased length of leaves at concentrations>0.02 mM. The distribution of the elements within the different tissues of leaves and roots was investigated by using Energy Dispersive X-Ray microanalysis (EDX) with a scanning electron microscope (SEM). EDX revealed that Cs and Sr were accumulated differently in root and leaf tissues. The hydroponic experiment showed a potential for A. halleri to treat hotspots with radioactive Cs and Sr.


Assuntos
Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Césio/metabolismo , Césio/toxicidade , Nitratos/metabolismo , Nitratos/toxicidade , Estrôncio/metabolismo , Estrôncio/toxicidade , Arabidopsis/crescimento & desenvolvimento , Biodegradação Ambiental , Hidroponia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/toxicidade
4.
Ecotoxicol Environ Saf ; 183: 109529, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31416013

RESUMO

Radioactive cesium (Cs) is more likely to be trans-located via rainfall into surrounding environments. Upon Cs-contaminated water reaching soil, Cs is retained on soil components, mainly organic matter and clay fraction. This study aims are i) comparing the relative ability of five arid soils, differing in their textural and chemical properties, to accumulate Cs when subjected to Cs-artificially contaminated rain droplets and ii) testing whether K fertilizer can decrease the uptake of Cs and its translocation within plants or not. A lab experiment was then conducted to simulate artificial rain droplets contaminated with 1000 becquerel (Bq) of 134Cs L-1 precipitated on soil columns each of 10.5 cm inner diameter at a rate of 1.15 mL cm-2 over a period of 2-months. At least 89% of 134Cs accumulated within the uppermost 5-cm layer of these soils. Another greenhouse experiment was set to test the hypothesis which indicates that Cs uptake increases unexpectedly by supplying plants with K-fertilizers. In this experiment, canola (Brassica napus L.) seeds were cultivated into three K-deficient soils (Typic Haplotorrent, Typic Haplocalcid, and Typic Torripsamment) which were contaminated with 100 mg Cs kg-1 soil (stable-Cs was used instead of radioactive-Cs to designate its behavior on the long run). Canola plants were fertilized with 0, 80 and 120 mg K2SO4 kg-1 soil. Results carried on Typic Haplotorrent soil confirmed the aforementioned assumption as K-addition increased Cd-uptake up to 40.1%. Contradictory results were achieved in the other two soils where Cs-uptake decreased by 21.5 and 15.3% in Typic Haplocalcid and Typic Torripsamment soils, respectively due to the application of the aforementioned dose of K. In the K non-amended soils, Cs shoot-root translocation factor was >1; yet, it was <1 in response to K addition, regardless of its application rate.


Assuntos
Brassica napus/efeitos dos fármacos , Césio/toxicidade , Fertilizantes/análise , Potássio/análise , Poluentes Radioativos do Solo/toxicidade , Solo/química , Brassica napus/crescimento & desenvolvimento , Césio/análise , Radioisótopos de Césio/análise , Clima Desértico , Egito , Chuva/química , Poluentes Radioativos do Solo/análise
5.
J Environ Radioact ; 195: 26-32, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30241014

RESUMO

The aim of our study was to investigate the toxicological mechanism of cesium on Indian mustard (Brassica juncea L.). The impact of cesium toxicity to plants was evaluated using phytophysiology and genetic methods. In this study, Brassica juncea was grown on Cs-contaminated Hoagland's nutrient solution, and chlorophyll content, chlorophyll fluorescence, and Cs bioaccumulation were measured. Transcriptome data was used to perform an in-depth analysis of the molecular mechanisms underlying the effects of Cs accumulation. The results showed that Cs accumulated up to 3586.70 mg kg-1 in B. juncea treated with 100 mg L-1 Cs. The chlorophyll content and several chlorophyll fluorescence parameters (Fv/F0, Fv/Fm, ΦPS II, qP, and NPQ) significantly decreased under Cs exposure. The starting process of PSII was also inhibited under higher Cs conditions. These results indicate that excessive Cs can damage PS II in leaves, decreasing photochemical activity and the energy conversion rate. Further analysis revealed that Cs interfered with the expression of chloroplastic metabolic genes (25 up and 36 down) and inhibited the expression of PsaB, psbC, PetF, LHCA1, and LHCB5. The results indicate that stable Cs leads to abnormal expression of genes related to photosynthesis pathway, blocking the electron transport process from plastoquinone-QA to plastoquinone-QB, resulting in abnormal photosynthesis, which leads to abnormal growth of B. juncea.


Assuntos
Césio/toxicidade , Mostardeira/fisiologia , Poluentes do Solo/toxicidade , Césio/metabolismo , Clorofila/metabolismo , Fluorescência , Mostardeira/efeitos dos fármacos , Mostardeira/metabolismo , Fotossíntese/efeitos dos fármacos , Plântula/efeitos dos fármacos , Poluentes do Solo/metabolismo
6.
Nanotoxicology ; 12(1): 63-78, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29262761

RESUMO

Dissolution and bandgap paradigms have been proposed for predicting the ability of metal oxide nanoparticles (NPs) to induce oxidative stress in different in vitro and in vivo models. Here, we addressed the effectiveness of these paradigms in vivo and under conditions typical of the marine environment, a final sink for many NPs released through aquatic systems. We used ZnO and MnO2 NPs as models for dissolution and bandgap paradigms, respectively, and CeO2 NPs to assess reactive oxygen radical (ROS) production via Fenton-like reactions in vivo. Oyster embryos were exposed to 0.5-500 µM of each test NP over 24 h and oxidative stress was determined as a primary toxicity pathway across successive levels of biological complexity, with arrested development as the main pathological outcome. NPs were actively ingested by oyster larvae and entered cells. Dissolution was a viable paradigm for predicting the toxicity of NPs in the marine environment, whereas the surface reactivity based paradigms (i.e. bandgap and ROS generation via Fenton-like reaction) were not supported under seawater conditions. Bio-imaging identified potential cellular storage-disposal sites of solid particles that could ameliorate the toxicological behavior of non-dissolving NPs, whilst abiotic screening of surface reactivity suggested that the adsorption-complexation of surface active sites by seawater ions could provide a valuable hypothesis to explain the quenching of the intrinsic oxidation potential of MnO2 NPs in seawater.


Assuntos
Nanopartículas Metálicas/toxicidade , Nanopartículas/toxicidade , Ostreidae/efeitos dos fármacos , Ostreidae/embriologia , Óxidos/toxicidade , Animais , Césio/química , Césio/toxicidade , Larva/efeitos dos fármacos , Larva/metabolismo , Compostos de Manganês/química , Nanopartículas Metálicas/química , Nanopartículas/química , Estresse Oxidativo/efeitos dos fármacos , Óxidos/química , Espécies Reativas de Oxigênio/metabolismo , Água do Mar , Solubilidade , Propriedades de Superfície , Óxido de Zinco/química , Óxido de Zinco/toxicidade
7.
Sci Rep ; 7(1): 1965, 2017 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-28512321

RESUMO

Biological incorporation of cesium ions (Cs+) has recently attracted significant attention in terms of the possible applications for bioremediation of radiocesium and their significant roles in biogeochemical cycling. Although high concentrations of Cs+ exhibit cytotoxicity on microorganisms, there are a few reports on the promotive effects of Cs+ on microbial growth under K+-deficient conditions. However, whether this growth-promoting effect is a common phenomenon remains uncertain, and direct correlation between growth promotion and Cs+ uptake abilities has not been confirmed yet. Here, we validated the growth promotive effects of Cs+ uptake under K+-deficient conditions using an Escherichia coli strain with an inducible expression of the Kup K+ transporter that has nonspecific Cs+ transport activities (strain kup-IE). The strain kup-IE exhibited superior growth under the Cs+-supplemented and K+-deficient conditions compared to the wild type and the kup null strains. The intracellular Cs+ levels were significantly higher in strain kup-IE than in the other strains, and were well correlated with their growth yields. Furthermore, induction levels of the kup gene, intracellular Cs+ concentrations, and the growth stimulation by Cs+ also correlated positively. These results clearly demonstrated that Cs+ incorporation via Kup transporter restores growth defects of E. coli under K+-deficient conditions.


Assuntos
Césio/metabolismo , Proteínas de Escherichia coli/metabolismo , Escherichia coli/fisiologia , Potássio/metabolismo , Transporte Biológico , Césio/toxicidade , Escherichia coli/efeitos dos fármacos , Proteínas de Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Mutação , Deficiência de Potássio/metabolismo
8.
Heart Rhythm ; 14(6): 912-919, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28193508

RESUMO

BACKGROUND: Our previous studies showed that renal sympathetic stimulation (RS) may facilitate ischemic ventricular arrhythmia (VA) by increasing left stellate ganglion (LSG) nerve activity, whereas renal sympathetic ablation (RA) may suppress VA. OBJECTIVE: The purpose of this study was to investigate whether renal sympathetic interventions also can affect VA by modulating LSG activity in a cesium-induced long QT canine model. METHODS: Twenty-four dogs were randomly divided into RS group (n = 8), RA group (n = 8), or control group (n = 8). Serum norepinephrine, LSG function, and LSG neural activity were measured before and 3 hours after RS or RA. Increasing doses of cesium chloride then were administered until a "threshold dose" produced sustained ventricular tachycardia or ventricular fibrillation. Early afterdepolarization amplitude, VA prevalence, and tachycardia threshold dose were compared among these groups. Nerve growth factor and c-fos protein expressed in the LSG also were examined. RESULTS: Serum norepinephrine, LSG function, and LSG neural activity were all significantly increased after 3 hours of RS and all were decreased 3 hours after RA. In addition, RS significantly decreased the tachycardia threshold dose, increased the early afterdepolarization amplitude, facilitated the incidence of VAs, and increased the expression of nerve growth factor and c-fos protein. In contrast, RA induced the opposite effects. CONCLUSION: RS promotes, whereas RA suppresses, the incidence of VAs in a canine model of cesium-induced long QT. Modulation of LSG neural activity by RS and RA may be responsible for these different effects.


Assuntos
Sistema Nervoso Autônomo/fisiopatologia , Ablação por Cateter/métodos , Terapia por Estimulação Elétrica/métodos , Eletrocardiografia , Frequência Cardíaca/fisiologia , Rim/inervação , Taquicardia Ventricular/terapia , Animais , Sistema Nervoso Autônomo/cirurgia , Césio/toxicidade , Modelos Animais de Doenças , Cães , Masculino , Gânglio Estrelado/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Sistema Nervoso Simpático/cirurgia , Taquicardia Ventricular/induzido quimicamente , Taquicardia Ventricular/fisiopatologia
9.
J Environ Radioact ; 160: 93-101, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27156168

RESUMO

To distinguish between the radiological and chemical effects of radiocesium, we study the chemical toxicity of cesium in the seedlings of Indian mustard (Brassica juncea L.). In this study, the experiment was designed in two factors and five levels random block design to investigate the interaction effects of Cs and K. Results showed that excessive Cs was one of the main factors influence the growth of Brassica juncea seedlings. And the toxicity of Cs in Brassica juncea is likely to be caused by Cs interacts with K-binding sites in essential K-dependent protein, either competes with K for essential biochemical functions, causing intracellular metabolic disturbance. To test the hypothesis that the toxicity of Cs might cause intracellular metabolic disturbance, next-generation sequencing (NGS)-based Illumina paired-end Solexa sequencing platform was employed to analysis the changes in gene expression, and understand the key genes in B. juncea seedlings responding to the toxicity of Cs. Based on the assembled de novo transcriptome, 2032 DEGs that play significant roles in the response to the toxicity of Cs were identified. Further analysis showed that excessive Cs is disturbance the auxin signal transduction pathway, and inhibited the indoleacetic acid-induced protein (AUX/IAA) genes expression eventually lead the seedlings growth and development be inhibited. The results suggest that disturbances to tryptophan metabolism might be linked to changes in growth.


Assuntos
Césio/toxicidade , Mostardeira/efeitos dos fármacos , Césio/farmacocinética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ácidos Indolacéticos/metabolismo , Mostardeira/genética , Mostardeira/crescimento & desenvolvimento , Mostardeira/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/genética , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Potássio/farmacologia , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/crescimento & desenvolvimento , Plântula/metabolismo
10.
Sci Rep ; 6: 20041, 2016 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-26883718

RESUMO

Interest in the interaction of microorganisms with cesium ions (Cs(+)) has arisen, especially in terms of their potent ability for radiocesium bioaccumulation and their important roles in biogeochemical cycling. Although high concentrations of Cs(+) display toxic effects on microorganisms, there have been only limited reports for Cs(+)-tolerant microorganisms. Here we report enrichment and isolation of Cs(+)-tolerant microorganisms from soil microbiota. Microbial community analysis revealed that bacteria within the phylum Bacteroidetes, especially Flavobacterium spp., dominated in enrichment cultures in the medium supplemented with 50 or 200 mM Cs(+), while Gammaproteobacteria was dominant in the control enrichment cultures (in the presence of 50 and 200 mM K(+) instead of Cs(+)). The dominant Flavobacterium sp. was successfully isolated from the enrichment culture and was closely related to Flavobacterium chungbukense with 99.5% identity. Growth experiments clearly demonstrated that the isolate has significantly higher tolerance to Cs(+) compared to its close relatives, suggesting the Cs(+)-tolerance is a specific trait of this strain, but not a universal trait in the genus Flavobacterium. Measurement of intracellular K(+) and Cs(+) concentrations of the Cs(+)-tolerant isolate and its close relatives suggested that the ability to maintain low intracellular Cs(+) concentration confers the tolerance against high concentrations of external Cs(+).


Assuntos
Adaptação Biológica , Césio , Flavobacterium/fisiologia , Íons , Césio/metabolismo , Césio/farmacologia , Césio/toxicidade , Cloretos/farmacologia , Cloretos/toxicidade , Escherichia coli/efeitos dos fármacos , Flavobacterium/classificação , Flavobacterium/efeitos dos fármacos , Flavobacterium/isolamento & purificação , Espaço Intracelular/metabolismo , Filogenia , Potássio/metabolismo , RNA Ribossômico 16S/genética , Solo/química , Microbiologia do Solo
11.
Bull Environ Contam Toxicol ; 96(3): 347-53, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26781630

RESUMO

The present study evaluated the impact of cesium ((133)Cs) at four concentrations (0, 0.001, 0.01, and 0.1 mg L(-1)) on growth, concentrations of chlorophyll and carotenoid pigments, and oxidative stress responses in the charophyte, Nitella pseudoflabellata, over 30 days. Oxidative stress was quantified by measuring anti-oxidant enzyme activities and H2O2 content. When compared with the control, significantly elevated activity levels of the anti-oxidative enzymes ascorbic peroxidase, catalase and guaiacol peroxidase were observed at 0.1 mg L(-1) (all p < 0.05), even though the H2O2 level was not significantly elevated. Carotenoid and chlorophyll a and b pigment levels were significantly reduced (all p < 0.05) at Cs exposures of 0.01 and 0.1 mg L(-1). Photosynthetic efficiency (i.e., Fv/Fm) was significantly reduced (p < 0.05) at Cs concentrations ≥0.001 mg L(-1). Significant reduction (p < 0.05) of plant growth (i.e., shoot length) was also observed after 1 week of exposure at Cs concentrations ≥0.001 mg L(-1). Our results suggested that Cs exposure reduced plant growth and affected plant functioning via activating the defense mechanism against oxidative stress in Nitella.


Assuntos
Césio/toxicidade , Nitella/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Antioxidantes/metabolismo , Carotenoides/metabolismo , Catalase/metabolismo , Clorofila/metabolismo , Clorofila A , Relação Dose-Resposta a Droga , Monitoramento Ambiental , Peróxido de Hidrogênio/metabolismo , Nitella/crescimento & desenvolvimento , Nitella/metabolismo , Oxirredução , Estresse Oxidativo/fisiologia , Peroxidase/metabolismo , Fotossíntese/efeitos dos fármacos
12.
Thyroid ; 25(11): 1199-208, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26332132

RESUMO

BACKGROUND: Impaired thyroid function is a common side effect of lithium medication. Recent data indicate that lithium exposure through drinking water, although providing much lower doses than the medication, may also affect thyroid hormone levels. However, the effects in susceptible groups like pregnant women are not known. METHODS: In a population-based mother-child cohort in the Argentinean Andes (n = 194), an area with varying concentrations of lithium in the drinking water, we assessed lithium exposure repeatedly during pregnancy by measuring the concentrations in blood using inductively coupled plasma mass spectrometry. The markers of thyroid function included thyrotropin (TSH), free/total thyroxine (fT4/T4), free/total triiodothyronine (fT3/T3), thyroglobulin, and transthyretin in serum, sampled at the same time. Multiple potential confounders, including exposure to arsenic, cesium, and boron (elevated in water) as well as selenium and iodine (essential for thyroid function) were considered. RESULTS: The lithium concentrations in blood [median 25 µg/L (0.0036 mmol/L); range 1.9-145 µg/L (0.000027-0.021 mmol/L)] correlated significantly with those in urine and drinking water (rs = 0.84, p < 0.001, and rs = 0.40, p < 0.001, respectively). Using linear quantile regression models, we found a positive association between blood lithium (log2 transformed) and TSH concentrations, particularly in the lowest percentiles of TSH (B = 0.20 mIU/L, [95% confidence interval 0.048-0.35] at the fifth percentile). We also found inverse associations of blood lithium with transthyretin, particularly at the highest percentiles, as well as with fT3 and T3, with less obvious variation across percentiles. Unexpectedly, blood cesium concentrations (median 111 µg/L, range 2.5-711 µg/L) were also inversely associated with fT3 and T3, particularly at the highest T3 percentiles, but not with TSH or transthyretin. Arsenic and boron exposure (also through drinking water) did not show any associations with the thyroid parameters. CONCLUSIONS: The study supports previous findings that lithium exposure through drinking water may impair thyroid function. The results regarding cesium exposure through drinking water are new. During pregnancy, impaired thyroid function may be detrimental for fetal development. The findings reinforce the need for better control of drinking water, including bottled water, as well as a health-based guideline value.


Assuntos
Césio/toxicidade , Exposição Ambiental , Lítio/toxicidade , Glândula Tireoide/efeitos dos fármacos , Adolescente , Adulto , Césio/análise , Água Potável/química , Feminino , Humanos , Lítio/análise , Pré-Albumina/metabolismo , Gravidez , Estudos Prospectivos , Tireoglobulina/sangue , Tireotropina/sangue , Tiroxina/sangue , Tri-Iodotironina/sangue , Adulto Jovem
13.
PLoS One ; 10(5): e0125514, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25946015

RESUMO

MicroRNAs (miRNAs) are short RNA fragments that play important roles in controlled gene silencing, thus regulating many biological processes in plants. Recent studies have indicated that plants modulate miRNAs to sustain their survival in response to a variety of environmental stimuli, such as biotic stresses, cold, drought, nutritional starvation, and toxic heavy metals. Cesium and radio-cesium contaminations have arisen as serious problems that both impede plant growth and enter the food chain through contaminated plants. Many studies have been performed to define plant responses against cesium intoxication. However, the complete profile of miRNAs in plants during cesium intoxication has not been established. Here we show the differential expression of the miRNAs that are mostly down-regulated during cesium intoxication. Furthermore, we found that cesium toxicity disrupts both the processing of pri-miRNAs and AGONOUTE 1 (AGO1)-mediated gene silencing. AGO 1 seems to be especially destabilized by cesium toxicity, possibly through a proteolytic regulatory pathway. Our study presents a comprehensive profile of cesium-responsive miRNAs, which is distinct from that of potassium, and suggests two possible mechanisms underlying the cesium toxicity on miRNA metabolism.


Assuntos
Proteínas de Arabidopsis/biossíntese , Arabidopsis/crescimento & desenvolvimento , Proteínas Argonautas/biossíntese , Césio/toxicidade , MicroRNAs/genética , Potássio/toxicidade , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas Argonautas/genética , Regulação da Expressão Gênica de Plantas , Raízes de Plantas/crescimento & desenvolvimento
14.
Bull Environ Contam Toxicol ; 94(4): 490-5, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25636440

RESUMO

A significant knowledge gap in nanotechnology is the absence of standardized protocols for examining the effect of engineered nanoparticles on soil microorganisms. In this study, agricultural soil was exposed to ZnO, SiO2, TiO2 and CeO2 nanoparticles at 1 mg g(-1). The toxicity effect was evaluated by thermal metabolism, the abundance of functional bacteria and enzymatic activity. ZnO and CeO2 nanoparticles were observed to hinder thermogenic metabolism, reduce numbers of soil Azotobacter, P-solubilizing and K-solubilizing bacteria and inhibit enzymatic activities. TiO2 nanoparticles reduced the abundance of functional bacteria and enzymatic activity. SiO2 nanoparticles slightly boosted the soil microbial activity. Pearson's correlation analysis showed that thermodynamic parameters had a strong correlation with abundance of functional bacteria and enzymatic activity. These findings demonstrated that the combined approach of monitoring thermal metabolism, functional bacteria and enzymatic activity is feasible for testing the ecotoxicity of nanoparticles on agricultural soil.


Assuntos
Bactérias/efeitos dos fármacos , Metaboloma/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Óxidos/toxicidade , Microbiologia do Solo , Poluentes do Solo/toxicidade , Solo/química , Agricultura/métodos , Césio/toxicidade , Nanotecnologia/métodos , Dióxido de Silício/toxicidade , Termodinâmica , Titânio/toxicidade , Óxido de Zinco/farmacologia
15.
J Radiat Res ; 56 Suppl 1: i29-35, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26825299

RESUMO

To investigate the transgenerational effects of chronic low-dose-rate internal radiation exposure after the Fukushima Daiichi Nuclear Power Plant accident in Japan, 18 generations of mice were maintained in a radioisotope facility, with free access to drinking water containing (137)CsCl (0 and 100 Bq/ml). The (137)Cs distribution in the organs of the mice was measured after long-term ad libitum intake of the (137)CsCl water. The litter size and the sex ratio of the group ingesting the (137)Cs water were compared with those of the control group, for all 18 generations of mice. No significant difference was noted in the litter size or the sex ratio between the mice in the control group and those in the group ingesting the (137)Cs water. The fixed internal exposure doses were ∼160 Bq/g and 80 Bq/g in the muscles and other organs, respectively.


Assuntos
Radioisótopos de Césio/toxicidade , Acidente Nuclear de Fukushima , Tamanho da Ninhada de Vivíparos/efeitos da radiação , Razão de Masculinidade , Animais , Césio/toxicidade , Cloretos/toxicidade , Feminino , Humanos , Camundongos , Doses de Radiação , Monitoramento de Radiação
16.
Environ Sci Technol ; 48(23): 13960-8, 2014 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-25343230

RESUMO

The effects of an exposure to three mass-produced metal oxide nanoparticles-similar in size and specific surface area but different in redox activity and solubility-were studied in rat alveolar macrophages (MAC) and epithelial cells (AEC). We hypothesized that the cell response depends on the particle redox activity and solubility determining the amount of reactive oxygen species formation (ROS) and subsequent inflammatory response. MAC and AEC were exposed to different amounts of Mn3O4 (soluble, redox-active), CeO2 (insoluble, redox-active), and TiO2 (insoluble, redox-inert) up to 24 h. Viability and inflammatory response were monitored with and without coincubation of a free-radical scavenger (trolox). In MAC elevated ROS levels, decreased metabolic activity and attenuated inflammatory mediator secretion were observed in response to Mn3O4. Addition of trolox partially resolved these changes. In AEC, decreased metabolic activity and an attenuated inflammatory mediator secretion were found in response to CeO2 exposure without increased production of ROS, thus not sensitive to trolox administration. Interestingly, highly redox-active soluble particles did not provoke an inflammatory response. The data reveal that target and effector cells of the lung react in different ways to particle exposure making a prediction of the response depending on redox activity and intracellular solubility difficult.


Assuntos
Poluentes Atmosféricos/toxicidade , Antioxidantes/farmacologia , Macrófagos Alveolares/efeitos dos fármacos , Nanopartículas/toxicidade , Animais , Antioxidantes/metabolismo , Linhagem Celular , Césio/toxicidade , Células Epiteliais/efeitos dos fármacos , Pulmão/citologia , Macrófagos Alveolares/metabolismo , Compostos de Manganês , Oxirredução , Óxidos/toxicidade , Ratos , Espécies Reativas de Oxigênio/metabolismo
17.
Cell Biochem Funct ; 32(5): 470-5, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24888554

RESUMO

The present study deals with the possible effects of selected environmental agents upon the uptake and metabolism of d-glucose in isolated acinar and ductal cells from the rat submandibular salivary gland. In acinar cells, the uptake of d-[U-(14) C]glucose and its non-metabolised analogue 3-O-[(14) C-methyl]-d-glucose was not affected significantly by phloridzin (0.1 mM) or substitution of extracellular NaCl (115 mM) by an equimolar amount of CsCl, whilst cytochalasin B (20 µM) decreased significantly such an uptake. In ductal cells, both phloridzin and cytochalasin B decreased the uptake of d-glucose and 3-O-methyl-d-glucose. Although the intracellular space was comparable in acinar and ductal cells, the catabolism of d-glucose (2.8 or 8.3 mM) was two to four times higher in ductal cells than in acinar cells. Phloridzin (0.1 mM), ouabain (1.0 mM) and cytochalasin B (20 µM) all impaired d-glucose catabolism in ductal cells. Such was also the case in ductal cells incubated in the absence of extracellular Ca(2+) or in media in which NaCl was substituted by CsCl. It is proposed that the ductal cells in the rat submandibular gland are equipped with several systems mediating the insulin-sensitive, cytochalasin B-sensitive and phloridzin-sensitive transport of d-glucose across the plasma membrane.


Assuntos
Células Acinares/metabolismo , Glucose/metabolismo , Glândula Submandibular/citologia , 3-O-Metilglucose/metabolismo , Células Acinares/citologia , Células Acinares/efeitos dos fármacos , Animais , Cálcio/metabolismo , Radioisótopos de Carbono/química , Células Cultivadas , Césio/toxicidade , Cloretos/toxicidade , Citocalasina B/farmacologia , Feminino , Ouabaína/toxicidade , Florizina/farmacologia , Ratos , Glândula Submandibular/efeitos dos fármacos
18.
ACS Appl Mater Interfaces ; 5(24): 12984-90, 2013 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-24295275

RESUMO

Nanoparticle (NPs) film of copper hexacyanoferrate (CuHCF(III)) was developed for electrochemically cesium separation from wastewater. Different form the electro- or chemical deposited films, CuHCF(III) NPs were firstly covered with ferrocyanide anions, so that they can be well dispersed in water and formed ink. Then CuHCF(III) NPs can be uniformly coated by simple wet printing methods, so it is feasible to prepare NPs film of any sizes, or any patterns at low cost. This process provided a promising technology for preparing large scale electrodes for sequential removal of Cs from wastewater in the columns. Cs separation can be controlled by an electrically switched ion exchange (ESIX) system. Effect of temperatures, and ionic strength on Cs removal was investigated. Thermodynamics results showed that Cs adsorption process was exothermic in nature and favored at low temperature. Ionic strength study indicated the CuHCF(III) film can selectively separate Cs in wide ionic strength range from 1 × 10(-4) to 1 × 10(-1) M Na(+). XPS results demonstrated that the electrochemical oxidation-reduction of Fe (II/III) made contributions to Cs separation.


Assuntos
Césio/química , Cobre/química , Nanopartículas/química , Purificação da Água , Césio/toxicidade , Ferrocianetos/química , Humanos , Termodinâmica , Águas Residuárias , Poluentes Químicos da Água
19.
Ukr Biokhim Zh (1999) ; 85(2): 105-9, 2013.
Artigo em Ucraniano | MEDLINE | ID: mdl-23808316

RESUMO

Cesium is lately accumulated actively in the environment, but its influence on human and animal organism is the least studied among heavy metals. It is shown that the action of cesium chloride in rats caused significant changes in blood chemistry, which are characterized by a decrease of total protein content, pH, an increase in the level of urea, creatinine, glucose and total hemoglobin. The results showed that potassium content in all the studied organs and tissues of poisoned rats decreases under the action of cesium chloride. Histological examination of the heart tissue in rats poisoned with cesium chloride indicates the onset of pathology of cardiovascular system. It was found out that use of the drug "Asparkam" reduces the negative effect of cesium chloride on the body of rats.


Assuntos
Sistema Cardiovascular/efeitos dos fármacos , Césio/toxicidade , Cloretos/toxicidade , Poluentes Ambientais/toxicidade , Animais , Proteínas Sanguíneas/análise , Sistema Cardiovascular/metabolismo , Sistema Cardiovascular/patologia , Rim/efeitos dos fármacos , Rim/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Especificidade de Órgãos , Potássio/metabolismo , Aspartato de Magnésio e Potássio/análogos & derivados , Aspartato de Magnésio e Potássio/farmacologia , Ratos
20.
Int J Mol Sci ; 14(6): 11438-43, 2013 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-23759992

RESUMO

In the special issue "Signaling Molecules and Signal Transduction in Cells" authors were invited to submit papers regarding important and novel aspects of extra- and intracellular signaling which have implications on physiological and pathophysiological processes. These aspects included compounds which are involved in these processes, elucidation of signaling pathways, as well as novel techniques for the analysis of signaling pathways. In response, various novel and important topics are elucidated in this special issue.


Assuntos
Células/metabolismo , Transdução de Sinais , Animais , Antineoplásicos/farmacologia , Comunicação Celular/efeitos dos fármacos , Césio/toxicidade , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Camundongos , Proteínas Quinases/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ubiquitinação/efeitos dos fármacos
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