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1.
Chemosphere ; 250: 126199, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32092568

RESUMO

As stand-alone approaches, chromatographic separations of arsenic in lichen using HPLC-ICP-MS or the use of sequential extractions have historically been shown to have low analyte recoveries and poor analyte selectivity respectively. This study modifies the first step of a sequential extraction with a chromatographic separation of five arsenic species using HPLC-ICP-MS, followed by a three-step sequential extraction and analysis with ICP-MS. The method was applied to lichens from a rural and urban site to demonstrate the applicability thereof, and the sum of arsenic concentrations from the extraction steps were compared to the total arsenic concentrations. Short term species stability of the As species in the lichen matrix was also evaluated over 1 month in the water-extractable fraction, where As species concentrations changed week by week, providing insight into biotransformation mechanisms. In the modified extraction step, dimethylarsinic acid (DMA) and arsenobetaine and an unknown As species (AsB + U1) were statistically (p < 0.05) higher in the urban site than the rural site. Analyte recoveries using the combined method were higher than other studies reported in literature, with percentage recoveries of 104% and 111% of As in the urban and rural sites respectively. Arsenic concentrations were found in the following order of abundance at both sites: oxidizable > reducible > water-extractable > residual. Concentrations of total As in the oxidizable and non-bioavailable fraction were statistically lower (p < 0.05) in the rural site than in the urban site. Based upon the information gained from this study, we could draw concise conclusions regarding the source apportionment, timing and the magnitude of the pollution event.


Assuntos
Arsênico/metabolismo , Poluentes Ambientais/metabolismo , Líquens/metabolismo , Arsênico/análise , Arsenicais , Ácido Cacodílico/análise , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos
2.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(1): 1-6, 2020 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-32027244

RESUMO

OBJECTIVE: To investigate the efficacy and safety of arsenic trioxide combined with ATRA and chemo- therapy for treatment of relapsed acute promyelocytic leukemia (APL) patients. METHODS: The clinic data of 25 patients with relapse APL treated in our hospital from 1996 to 2013 were collected and analyzed. Among the 25 patients, 15 patients suffered first-time hematological relapse (HR), and the other 10 patients showed first-time molecular relapse (MR). The patients with first-time replase were treated with ATO+ATRA+Anthracycline re-induction chemotherapy. The clinical features, complete remission (CR) rate, overall survival (OS), disease-free survival (DFS) and adverse events after re-induction therapy were analyzed. RESULTS: Fourteen of 15 hematological relapsed patients achieved the second-time hematological complete remission (CR2) after re-induction therapy except one patient died of bleeding complication during the re-induction. 8 of 14 patient showed molecular complete remission (CRm) after two cycles of therapy with this regimen. Totally, eleven out of the 14 HR patients were alive without disease till the last follow-up, and 3 of the 14 HR patients died because of bleeding complications. All of the 10 molecular relapsed patients received the second CRm after treated by the regimen. Among these 10 patients, 6 patients suffered only once relapse and continued with the molecular CR2 status, and for the other 4 patients with more than two-relapses, only 1 survived untill 89.3 months after achieved second-time CRm, and other 3 patients died because of bleeding complications. CONCLUSION: For relapsed APL patients, the treatment with ATO+ATRA+chemotherapy regimen after relapse still shows encouraging efficacy, no matter whether or not the application of ATO in the previous regimens. In addition, patients with more than two molecular relapses show a poor prognosis.


Assuntos
Arsenicais , Leucemia Promielocítica Aguda , Protocolos de Quimioterapia Combinada Antineoplásica , Trióxido de Arsênio , Humanos , Leucemia Promielocítica Aguda/tratamento farmacológico , Óxidos , Indução de Remissão , Resultado do Tratamento , Tretinoína
3.
Ecotoxicol Environ Saf ; 193: 110334, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32088552

RESUMO

The bioaccessibility of total arsenic (tAs) and arsenic species in Bellamya aeruginosa collected from Xiangjiang River was evaluated using an in vitro digestion model, to assess the potential health risks to local residents. The tAs concentrations in gastropod samples ranged from 1.98 to 6.33 mg kg-1 (mean 3.79 ± 1.60 mg kg-1). Five arsenic species including arsenite [As(III)], arsenate [As(V)], dimethylarsinic acid (DMA), arsenobetaine (AsB), and arsenocholine (AsC) were detected. Inorganic arsenic (iAs) concentrations, which were about a half of organic arsenic (oAs), were higher than the maximum permissible limit (≤0.50 mg kg-1 in aquatic products). Bioaccessible concentrations of tAs in digestive juices were found to be decreased in the order: intestinal phase > gastric phase > salivary phase. As(III) and AsC were the predominant species, but AsB was not detectable in all digestive juices. Bioaccessible iAs concentrations, which were close to the level of bioaccessible oAs, were not significantly different among three digestive juices, but also above 0.50 mg kg-1. Accordingly, bioaccessibility of tAs was highest in intestinal phase (48%), then in gastric phase (40%), and lowest in salivary phase (33%). Bioaccessibility of As(III) was close to 100%, and bioaccessibility of iAs was much higher than that of oAs. The mean values of target hazard quotient (THQ) and bioaccessible THQ were 0.80 and 0.70, respectively. The probability of experiencing non-carcinogenic effects was reduced to 18% down from 22% as considering iAs bioaccessibility. The mean values of carcinogenic risk (CR) and bioaccessible CR were higher than the acceptable value (1 × 10-4). Gastropod consumption from sampling sites may cause a potential carcinogenic risk.


Assuntos
Arsênico/toxicidade , Gastrópodes/química , Rios/química , Poluentes Químicos da Água/toxicidade , Animais , Arseniatos/análise , Arsênico/análise , Arsenicais/análise , Arsenitos/análise , Ácido Cacodílico/análise , Humanos , Modelos Biológicos , Medição de Risco , Poluentes Químicos da Água/análise
4.
Food Chem ; 315: 126215, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32014664

RESUMO

The accumulation and transformation of arsenic species have been studied in the context of hydroponic cultivation of strawberry plants. Cultivation experiments have been performed by adding inorganic arsenic at concentrations of 10, 100 and 1000 µg L-1 via root irrigation. The total arsenic content was determined by Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS). The accumulation was dependent on the concentration of arsenic added to the irrigation and the arsenic species. Arsenic (III) accumulated at higher rates than arsenic (V). A greater accumulation of arsenic was found in roots (0.44-4.10 mg kg-1) than in stems (0.43-1.27 mg kg-1) and fruits (0.22-0.30 mg kg-1). The speciation results obtained by HPLC-HG-AFS analysis indicated that the addition of As(III) resulted in a partial methylation producing monomethyl arsenic (MMA) and dimethyl arsenic (DMA). After As(V) addition, only MMA was observed and this was accompanied with a notable reduction in the ratio of As(V) to As(III).


Assuntos
Arseniatos/administração & dosagem , Arsênico/metabolismo , Arsenitos/administração & dosagem , Fragaria/metabolismo , Irrigação Agrícola , Arsênico/análise , Arsenicais , Cromatografia Líquida de Alta Pressão , Frutas/metabolismo , Hidroponia , Metilação , Especificidade de Órgãos , Raízes de Plantas/metabolismo , Caules de Planta/metabolismo , Espectrometria de Fluorescência
5.
Ecotoxicol Environ Saf ; 191: 110215, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31978765

RESUMO

Information on the kinetic characteristics of soil enzymes under long-term arsenic (As) pollution in field soils is scarce. We investigated Michaelis-Menten kinetic properties of four soil enzymes including ß-glucosidase (BG), acid phosphatase (ACP), alkaline phosphatase (ALP), and dehydrogenase (DHA) in field soils contaminated by As resulting from long-term realgar mining activity. The kinetic parameters, namely the maximum reaction velocity (Vmax), enzyme-substrate affinity (Km) and catalytic efficiency (Vmax/Km) were calculated. Results revealed that the enzyme kinetic characteristics varied in soils and were significantly influenced by total nitrogen (N) and total As, which explained 31.8% and 30.7% of the variance in enzyme kinetics respectively. Enzyme pools (Vmax) and catalytic efficiency (Vmax/Km) of BG, ACP and DHA decreased with elevated As pollution, while the enzyme affinity for substrate (Km) was less affected. Redundancy analysis and stepwise regression suggested that the adverse influence of As on enzyme kinetics may offset or weakened by soil total N and soil organic matter (SOM). Concentration-response fitting revealed that the specific kinetic parameters expressed as the absolute enzyme kinetic parameters multiplied by normalized soil total N and SOM were more relevant than the absolute ones to soil total As. The arsenic ecological dose values that cause 10% decrease (ED10) in the specific enzyme kinetics were 20-49 mg kg-1, with a mean value of 35 mg kg-1, indicating a practical range of threshold for As contamination at field level. This study concluded that soil enzymes exhibited functional adaptation to long-term As stress mainly through the reduction of enzyme pools (Vmax) or maintenance of enzyme-substrate affinity (Km). Further, this study demonstrates that the specific enzyme kinetics are the better indicators of As ecotoxicity at field-scale compared with the absolute enzyme parameters.


Assuntos
Arsênico/toxicidade , Enzimas/química , Poluentes do Solo/toxicidade , Solo/química , Arsênico/análise , Arsenicais , Biomarcadores Ambientais/efeitos dos fármacos , Cinética , Mineração , Nitrogênio/análise , Compostos Orgânicos/análise , Poluentes do Solo/análise , Sulfetos/toxicidade
6.
Ecotoxicol Environ Saf ; 190: 110136, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31901806

RESUMO

Large areas of the paddy fields in South China are contaminated with arsenic (As), which causes serious problems, including high As concentrations in brown rice. Three As-resistant iron-oxidizing bacteria (FeOB) namely, Bacillus sp. T2, Pseudomonas sp. Yangling I4 and Bacillus sp. TF1-3, were isolated and applied to rice grown in different As-contaminated environments to study the effects of FeOB on the As accumulation in rice and clarify the possible mechanisms involved. The results showed that FeOB inoculation significantly decreased the inorganic As concentrations in brown rice grown in pots and paddy fields by 3.7-13.3% and 4.6-12.1%, respectively. FeOB inoculation enhanced the formation of Fe plaque, which sequestered more As on the root surface. Moreover, a significantly lower level of As(III) influx was observed in the rice cultivated with FeOB than in the control. FeOB inoculation also decreased the As concentrations in pore water and the Fe(II)/Fe(III) ratio in rhizosphere soil. The present results suggest that FeOB inoculation decreased the inorganic As concentrations in brown rice by affecting the formation of Fe plaque, As(III) uptake kinetics and rhizosphere soil properties. Based on our results, FeOB inoculation could be considered a useful method to decrease inorganic As concentrations in brown rice grown in As-contaminated paddy fields.


Assuntos
Arsênico/metabolismo , Oryza/fisiologia , Poluentes do Solo/metabolismo , Arsênico/análise , Arsenicais , Bactérias , China , Compostos Férricos , Ferro , Oxirredução , Raízes de Plantas/química , Rizosfera , Solo , Poluentes do Solo/análise
7.
J Agric Food Chem ; 68(7): 1910-1934, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31999115

RESUMO

Setting regulatory limits for arsenic in food is complicated, owing to the enormous diversity of arsenic metabolism in humans, lack of knowledge about the toxicity of these chemicals, and lack of accurate arsenic speciation data on foodstuffs. Identification and quantification of the toxic arsenic compounds are imperative to understanding the risk associated with exposure to arsenic from dietary intake, which, in turn, underscores the need for speciation analysis of the food. Arsenic speciation in seafood is challenging, owing to its existence in myriads of chemical forms and oxidation states. Interconversions occurring between chemical forms, matrix complexity, lack of standards and certified reference materials, and lack of widely accepted measurement protocols present additional challenges. This review covers the current analytical techniques for diverse arsenic species. The requirement for high-quality arsenic speciation data that is essential for establishing legislation and setting regulatory limits for arsenic in food is explored.


Assuntos
Arsenicais/química , Técnicas de Química Analítica/métodos , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Alimentos Marinhos/análise , Animais , Arsenicais/isolamento & purificação
8.
J Agric Food Chem ; 68(4): 943-960, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-31913614

RESUMO

Diet, especially seafood, is the main source of arsenic exposure for humans. The total arsenic content of a diet offers inadequate information for assessment of the toxicological consequences of arsenic intake, which has impeded progress in the establishment of regulatory limits for arsenic in food. Toxicity assessments are mainly based on inorganic arsenic, a well-characterized carcinogen, and arsenobetaine, the main organoarsenical in seafood. Scarcity of toxicity data for organoarsenicals, and the predominance of arsenobetaine as an organic arsenic species in seafood, has led to the assumption of their nontoxicity. Recent toxicokinetic studies show that some organoarsenicals are bioaccessible and cytotoxic with demonstrated toxicities like that of pernicious trivalent inorganic arsenic, underpinning the need for speciation analysis. The need to investigate and compare the bioavailability, metabolic transformation, and elimination from the body of organoarsenicals to the well-established physiological consequences of inorganic arsenic and arsenobetaine exposure is apparent. This review provides an overview of the occurrence and assessment of human exposure to arsenic toxicity associated with the consumption of seafood.


Assuntos
Arsenicais/análise , Exposição Dietética/efeitos adversos , Contaminação de Alimentos/análise , Alimentos Marinhos/análise , Animais , Arsenicais/metabolismo , Exposição Dietética/análise , Humanos , Medição de Risco
9.
Chemosphere ; 241: 124956, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31605996

RESUMO

High contents of arsenic were detected in soils in Guandu plain, northwest Taiwan. To determine the sources and speciation of As in the soils, the depth profiles of soil properties, elemental composition and As speciation were investigated. The As concentrations in the soil profile ranged from 152 to 1222 mg kg-1, with the highest concentration at the depth of 70-80 cm. The As distribution was found to be positively correlated to Fe, Pb, and Ba. The As(V)-adsorbed ferrihydrite and scorodite were the predominant phases in the top layers (<50 cm), while beudantite was the predominant phase below 50 cm along with As(III)- and As(V)-adsorbed ferrihydrite as the minor components. The results of sequential extraction showed that As-associated with noncrystalline and crystalline Fe/Al hydrous oxides and residual phases were predominant at the depths of 0-60, 60-100 and 100-140 cm, respectively, indicating an increasing As recalcitrance with soil depth. Based on the soil properties, and elemental and mineral compositions at different soil depths, the origin of beudantite in the soils was likely allogenic rather than authigenic or anthropogenic. The formation of scorodite in the surface soils was suggested to be transformed from beudantite. As-associated Fe hydrous oxides may be contributed by the progressive dissolution of beudantite and scorodite, and the continuous influxes of As and Fe. While Fe hydrous oxides were able to immobilize As during the dissolution of As-bearing minerals, the increase of As mobility in soils may imply an increase in the environmental risk of As over time.


Assuntos
Arsênico/análise , Poluentes do Solo/análise , Solo/química , Arsênico/química , Arsênico/normas , Arsenicais/análise , Compostos Férricos/análise , Minerais/análise , Taiwan , Espectroscopia por Absorção de Raios X
10.
J Basic Microbiol ; 60(1): 47-57, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31680284

RESUMO

The present investigation deals with the characterisation of three As-resistant bacteria, Bacillus aryabhattai strain VPS1, Bacillus licheniformis strain VPS6 and Sporosarcina thermotolerans strain VPS7 isolated from the rhizosphere of a contaminated paddy field in Chakdaha, Nadia, West Bengal, India. Two strains, VPS6 and VPS7 showed ureolytic activity, which can be used for microbial-induced calcite precipitation of As as a bioremediation option. However, As reduction and oxidation capacities were not reported in any of these bacteria. A phylogenetic tree of 16S ribosomal RNA gene sequences was constructed for all three bacterial isolates, including different species of As-resistant Bacillus and Sporosarcina. Furthermore, literature survey and genome mining were employed to explore the diversity of As resistance-related proteins, arsenite S-adenosylmethyltransferase (ArsM) and arsenical pump membrane protein (ArsB) among different bacteria, and the phylogenetic relatedness was studied to understand the distribution and evolution of their amino acid sequences. ArsB was predominantly present in a wide variety of bacteria (347 taxa); however, ArsM was reported in comparatively fewer isolates (109 taxa). There were a total of 60 similar taxa that contained both ArsM and ArsB. Both proteins were most abundantly present in phylum Proteobacteria. Overall, this investigation enumerates As-resistant bacteria to understand the As metabolism in the environment, and the phylogenetic analysis of As resistance-related proteins helps in understanding the functional relationship in different bacteria for their role in As mobility in the environment.


Assuntos
Arsenicais/metabolismo , Bactérias/metabolismo , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Poluentes do Solo/metabolismo , Bacillus/genética , Bacillus/metabolismo , Bacillus licheniformis/genética , Bacillus licheniformis/metabolismo , Bactérias/classificação , Bactérias/genética , Biodegradação Ambiental , Índia , Filogenia , RNA Ribossômico 16S/genética , Rizosfera , Microbiologia do Solo , Sporosarcina/genética , Sporosarcina/metabolismo , Ureia/metabolismo
11.
Environ Pollut ; 256: 113459, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31708282

RESUMO

Previous studies have indicated that natural organic matter in the aquatic environment could affect arsenic bioaccumulation and biotransformation to aquatic organisms. However, the differences between the effects of arsenite and arsenate exposure have not been studied and compared in fish exposure models. In this study, adult zebrafish (Danio rerio) were exposed to 5 mg/L inorganic As solutions, in the presence of a range of humic acid (HA) concentrations (1, 2.5, 5, 10, 20 mg/L) in 96 h waterborne exposure. Results showed that in the presence of HA, total As bioaccumulation was significantly reduced in zebrafish following arsenite exposure, while this reduction was not observed during arsenate exposure. The reduction in total arsenic bioaccumulation for arsenite exposure can be explained by the fact that HA forming a surface coating on the cell surface, hindering transport and internalization. However, this reduction in total As was not observed due to differences in uptake pathways for arsenate exposure. Results also showed that Arsenobetaine (AsB) was the main biotransformation product in zebrafish following inorganic As exposure, accounting for 44.8%-64.7% of extracted arsenic species in all exposure groups. The addition of HA caused levels of MMA and As(III) to decrease, while the distribution of AsB significantly increased in arsenite exposure groups. The increase in AsB could be because the As(III)-HA complex was formed, affecting the methylation of As(III). In contrast, the addition of HA to arsenate exposure groups, did not affect the reduction of As(V) to As(III) and therefore, an increase in the distribution of AsB was not observed in arsenate exposure groups. This study provides useful information on the mechanisms of toxicity, for improved risk assessment of As in natural aquatic environments.


Assuntos
Arsênico/metabolismo , Substâncias Húmicas , Poluentes Químicos da Água/metabolismo , Peixe-Zebra/fisiologia , Animais , Arseniatos , Arsenicais , Arsenitos , 32418 , Biotransformação , Metilação , Peixe-Zebra/metabolismo
12.
Chemosphere ; 239: 124712, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31499310

RESUMO

Selenium can regulate arsenic toxicity by strengthening antioxidant potential, but the antagonism between selenite or selenate nutrient and the translocation of arsenic species from paddy soil to different rice organs are poorly understood. In this study, a pot experiment was designed to investigate the effect of selenite or selenate on arsenite or arsenate toxicity to two indica rice cultivars (namely Ming Hui 63 and Lu You Ming Zhan), and the uptake and transportation of arsenic species from paddy soil to different rice organs. The results showed that selenite or selenate could significantly decrease the arsenate concentration in pore water of soils, and thus inhibited arsenate uptake by rice roots. However, the existence of selenite or selenate didn't decrease arsenate concentration in rhizosphere pore water of two indica rice cultivars. There existed good antagonistic effect between selenite or selenate and the uptake of arsenite and arsenate in rice plant in the case of low arsenic paddy soil. However, this antagonism depended on rice cultivars, arsenic species and arsenic level in soil. There existed both synergistic and inhibiting effects between the addition of selenite or selenate and the uptake of trimethylarsinoxide and dimethylarsinic acid by two indica rice cultivars, but the mechanism was unclear. Both selenite and selenate are all effective to decrease the translocation of inorganic arsenic from the roots to their above-ground rice organs in arsenite/arsenate-spiked paddy soil, but selenate had stronger inhibiting effect on their transfer factors than selenite.


Assuntos
Arsênico/farmacocinética , Oryza/metabolismo , Selênio/farmacologia , Solo/química , Arsênico/toxicidade , Arsenicais/farmacocinética , Arsenicais/farmacologia , Transporte Biológico , Interações Medicamentosas , Oryza/efeitos dos fármacos , Ácido Selênico/farmacologia , Ácido Selenioso/farmacologia
13.
Chemosphere ; 239: 124823, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31726520

RESUMO

Several studies have demonstrated that gypsum (CaSO4·2H2O) and calcite (CaCO3) can be important hosts of arsenic in contaminated hydrogeological systems. However, the extent to which microbial reducing processes contribute to the dissolution and transformation of carbonate and sulfate minerals and, thereby, to arsenic mobilization is poorly understood. These processes are likely to have a strong impact on arsenic mobility in iron-poor environments and in reducing aquifers where iron oxyhydroxides become unstable. Anoxic batch bioassays with arsenate (As(V)) coprecipitated with calcite, gypsum, or ferrihydrite (Fe(OH)3) were conducted in the presence of sulfate or molybdate to examine the impact of bioprocesses (i.e. As(V), sulfate, and Fe(III)-reduction) on arsenic dissolution, speciation, and eventual remineralization. Microbial reduction of As(V)-bearing calcite caused an important dissolution of arsenite, As(III), which remained in solution up to the end of the experiment (30 days). The reduction of As(V) from gypsum-As(V) also led to the release of As(III), which was subsequently remineralized, possibly as arsenic sulfides. The presence of sulfate triggered arsenic dissolution in the bioassays with ferrihydrite-As(V). This study showed that although gypsum and calcite have a lower capacity to bind arsenic, compared to iron oxides, they can play a critical role in the biogeochemical cycle of arsenic in natural calcareous and gypsiferous systems depleted of iron since they can be a source of electron acceptors for reducing bioprocesses.


Assuntos
Arsênico/química , Bactérias/metabolismo , Carbonato de Cálcio/química , Sulfato de Cálcio/química , Compostos Férricos/química , Arseniatos/química , Arsenicais/química , Arsenitos/química , Carbonatos/química , Água Subterrânea/química , Ferro/química , Molibdênio/química , Oxirredução , Solubilidade , Sulfatos/química , Sulfetos/química
14.
Chemosphere ; 246: 125685, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31887488

RESUMO

Arsenic (As) is a natural environmental contaminant to which humans are usually exposed in water, air, soil, and food. China is a typical high-As region, and also a great contributor of the world production of cultivated edible mushrooms and a region abundant in wild growing edible mushrooms. Mushrooms can accumulate different amounts of As and different As compounds, so potential health risk of As intake may exist to people who use mushrooms with elevated As contents as food or medicine. A systematic literature search was carried out for studies on As and As compounds in mushrooms from China. We compiled existing data from published sources in English or Chinese and provide an updated review of the findings on As in mushrooms associated with environments and health risks. Future perspectives for studies on As in mushrooms have also been discussed.


Assuntos
Agaricales/química , Arsênico/análise , Arsenicais , China , Contaminação de Alimentos/análise , Humanos , Solo , Água
15.
Biosens Bioelectron ; 147: 111784, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31654823

RESUMO

This paper presents a microwave sensor designed as a capacitive matrix for label-free Escherichia coli detection. The mean value of capacitances' change in the capacitive matrix sensor is an indicator of the bacteria detection. The theoretical analysis was confirmed by the realization of an exemplary sensor chip manufactured using the United Monolithic Semiconductor (UMS) PH25 process on a 100 µm thick GaAs substrate and measurements of various concentrations of Escherichia coli in the frequency range 1-3 GHz. The matrix topology of the sensor together with biofunctionalization of the sensor surface with polyclonal anti-Escherichia coli antibody allow to obtain high detection sensitivity on various concentrations of Escherichia coli reaching 103 CFU/ml. The obtained results are promising for future biomedical applications, in terms of specific bacteria presence detection.


Assuntos
Técnicas Biossensoriais , Infecções por Escherichia coli/diagnóstico , Escherichia coli/isolamento & purificação , Arsenicais/química , Capacitância Elétrica , Escherichia coli/patogenicidade , Infecções por Escherichia coli/microbiologia , Gálio/química , Humanos , Micro-Ondas
16.
J Ethnopharmacol ; 247: 111576, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30385423

RESUMO

AIM OF THE STUDY: Because the toxicity and efficacy of arsenic is closely related to its chemical species, we conducted examinations of arsenic species accumulation and distribution in the rat body after one-time and 30-day realgar administration and then elucidated the probable roles of different arsenic species in the short-term toxicity of realgar. MATERIALS AND METHODS: According to ICH M3 guidelines for non-clinical repeated dose toxicity studies and OECD Test guideline TG407 "Repeated Dose 28-Day oral Toxicity Study in Rodents, the doses of realgar set were 10.6 mg/kg, 40.5 mg/kg and 170 mg/kg. Rats were orally administered with realgar for one-tme and 30 days, respectively. Thereafter, biological samples (plasma, urine, liver, kidney, and brain) were obtained from rats and analyzed using high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) to determine realgar metabolism, arsenic species accumulation and distribution. Additionally, the toxicity of realgar in rats was evaluated. RESULTS: The absorption, distribution and elimination half-life of total arsenic species in realgar were 3.33 hs, 16.08 hs and 24.65 hs, respectively. After 30 days of oral administration of realgar in rats, no significant drug-related toxicity occurred in the rats. Dimethylarsenic acid (DMA) is the most abundant arsenic species. The DMA contents of the liver and kidney of the high-dose realgar group were approximately 40-fold and 50-fold higher than those in the corresponding tissues of the control group, respectively. The arsenic species (III) was mainly detected in the liver and its content was about 40-fold higher than that of the control group. MMA was mainly detected in rat kidney, and the MMA content of the realgar treatment group was more than 2000 times higher than that of the control group. CONCLUSIONS: Arsenic is rapidly absorbed and distributed over the liver, kidneys and brain, and the distribution and elimination of arsenic in the blood is slow. The realgar doses corresponded to human equivalent doses (HED) of 1.7, 6.4 and 27.2 mg/kg, respectively. Considering that humans are 10 times more sensitive than animals, the realgar dose is equivalent to 0.17, 0.64 and 2.7 mg/kg HED. It can be considered that if patients take no more than 2.7 mg/kg realgar for 2 weeks, there will be no adverse reactions.


Assuntos
Arsenicais/farmacocinética , Sulfetos/farmacocinética , Administração Oral , Animais , Arsenicais/administração & dosagem , Encéfalo/metabolismo , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/farmacocinética , Medicamentos de Ervas Chinesas/toxicidade , Feminino , Absorção Gastrointestinal , Meia-Vida , Rim/metabolismo , Fígado/metabolismo , Masculino , Espectrometria de Massas , Ratos , Sulfetos/administração & dosagem , Sulfetos/toxicidade , Distribuição Tecidual , Testes de Toxicidade Aguda
17.
J Ethnopharmacol ; 247: 112299, 2020 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-31606537

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Hua-Feng-Dan (HFD) is a traditional Chinese medicine used for neurological disorders. HFD contains cinnabar (HgS) and realgar (As4S4). The ethnopharmacological basis of cinnabar and realgar in HFD is not known. AIM OF THE STUDY: To address the role of cinnabar and realgar in HFD-produced neuroprotection against neurodegenerative diseases and disturbance of gut microbiota. MATERIALS AND METHODS: Lipopolysaccharide (LPS) plus rotenone (ROT)-elicited rat dopaminergic (DA) neuronal damage loss was performed as a Parkinson's disease animal model. Rats were given a single injection of LPS. Four months later, rats were challenged with the threshold dose of ROT. The clinical dose of HFD was administered via feed, starting from ROT administration for 46 days. Behavioral dysfunction was detected by rotarod and Y-maze tests. DA neuron loss and microglial activation were assessed via immunohistochemical staining and western bolt analysis. The colon content was collected to extract bacterial DNA followed by real-time PCR analysis with 16S rRNA primers. RESULTS: LPS plus ROT induced neurotoxicity, as evidenced by DA neuron loss in substantia nigra, impaired behavioral functions and increased microglial activation. HFD-original (containing 10% cinnabar and 10% realgar) rescued loss of DA neurons, improved behavioral dysfunction and attenuated microglial activation. Compared with HFD-original, HFD-reduced (3% cinnabar and 3% realgar) was also effective, but to be a less extent, while HFD-removed (without cinnabar and realgar) was ineffective. In analysis of gut microbiome, the increased Verrucomicrobiaceae and Lactobacteriaceae, and the decreased Enterobacteeriaceae by LPS plus ROT were ameliorated by HFD-original, and to be the less extent by HFD-reduced. CONCLUSION: Cinnabar and realgar are active ingredients in HFD to exert beneficial effects in a neurodegenerative model and gut microbiota.


Assuntos
Arsenicais/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Compostos de Mercúrio/farmacologia , Fármacos Neuroprotetores/farmacologia , Síndromes Neurotóxicas/tratamento farmacológico , Sulfetos/farmacologia , Animais , Arsenicais/química , Arsenicais/uso terapêutico , DNA Bacteriano/isolamento & purificação , Modelos Animais de Doenças , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/patologia , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/uso terapêutico , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/genética , Enterobacteriaceae/isolamento & purificação , Etnofarmacologia , Microbioma Gastrointestinal/genética , Microbioma Gastrointestinal/imunologia , Humanos , Mediadores da Inflamação/metabolismo , Lactobacillaceae/efeitos dos fármacos , Lactobacillaceae/genética , Lactobacillaceae/isolamento & purificação , Lipopolissacarídeos/toxicidade , Masculino , Compostos de Mercúrio/química , Compostos de Mercúrio/uso terapêutico , Microglia/efeitos dos fármacos , Microglia/imunologia , Microglia/patologia , Degeneração Neural , Fármacos Neuroprotetores/química , Fármacos Neuroprotetores/uso terapêutico , Síndromes Neurotóxicas/etiologia , Síndromes Neurotóxicas/imunologia , Síndromes Neurotóxicas/patologia , RNA Ribossômico 16S/genética , Ratos , Rotenona/toxicidade , Sulfetos/química , Sulfetos/uso terapêutico , Verrucomicrobia/efeitos dos fármacos , Verrucomicrobia/genética , Verrucomicrobia/isolamento & purificação
18.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 44(10): 1143-1150, 2019 Oct 28.
Artigo em Chinês | MEDLINE | ID: mdl-31857508

RESUMO

OBJECTIVE: To explore the antiviral activity of nano-realgar against herpes simplex virus Type II (HSV-2) in vitro.
 Methods: Acyclovir (ACV) as a positive control, the cytotoxicity of nano-realgar at different concentrations (including 200.00, 150.00, 100.00, 50.00, 25.00, 12.50, 6.25, 3.13, 1.54, 0.78, 0.39 and 0 mg/L) on normal Vero cells were determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. HSV-2 virus titer was determined by plaque assay, and the Vero cells model of HSV-2 infection was established. Subsequently, the antiviral effects of nano-realgar at different concentrations (including 20.00, 10.00, 5.00, 2.50, 1.25, 0.63, 0.31, 0.15, 0.08, 0.04 and 0 mg/L) on infected cells model were evaluated by the observation of cytopathic effect (CPE) and MTT method under the 3 modes including pre-treatment, treatment and direct inactivation.
 Results: The 50% cytotoxic concentration (CC50) of nano-realgar on Vero cells was 37.15 mg/L. The titer of HSV-2 was 7.30 log PFUs/mL. In the 3 modes, the half-maximal effective concentration (EC50) of nano-realgar on HSV-2 infected Vero cells were 0.13, 1.80 and 0.52 mg/L, and the corresponding therapeutic index (TI) were 285.77, 20.64, 71.44, respectively. The TI value of nano-realgar on pre-treatment mode was higher than that of nano-realgar on treatment and direct inactivation modes.
 Conclusion: Nano-realgar can play a good anti-HSV-2 activity in the 3 modes (pre-treatment, treatment and direct inactivation), and the anti-HSV-2 efficacy of nano-realgar on pre-treatment mode is better than that of nano-realagr on other 2 modes.


Assuntos
Herpesvirus Humano 2 , Animais , Antivirais , Arsenicais , Chlorocebus aethiops , Herpesvirus Humano 1 , Sulfetos , Células Vero
19.
Technol Cancer Res Treat ; 18: 1533033819896806, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31868118

RESUMO

OBJECTIVE: This study aimed to investigate the effect of tetra-arsenic tetra-sulfide on treating multiple myeloma and its potential regulation on suppressor of cytokine signaling 1 methylation-mediated Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway. METHODS: Tetra-arsenic tetra-sulfide with different concentrations were used to treat U266 cells, and cell viability was measured at 12, 24, and 48 hours with 0 µM tetra-arsenic tetra-sulfide treatment as control by Cell Counting Kit-8 assay. Suppressor of cytokine signaling 1 methylation and expression were determined by methylation-specific polymerase chain reaction, quantitative polymerase chain reaction, and Western blot, respectively, in U266 cells and normal plasma cells and in U266 cells treated by tetra-arsenic tetra-sulfide. Then, rescue experiments were performed by transfecting suppressor of cytokine signaling 1 small interfering RNA into tetra-arsenic tetra-sulfide-treated U266 cells. Besides, phosphor-Janus kinase 2, Janus kinase 2, phospho-signal transducer and activator of transcription 3, and signal transducer and activator of transcription 3 expressions were determined by Western blot. RESULTS: Tetra-arsenic tetra-sulfide inhibited U266 cell viability efficiently in a dose- and time-dependent manner. Suppressor of cytokine signaling 1 methylation was higher while suppressor of cytokine signaling 1 expression was lower in U266 cells compared to normal plasma cells; when treated by tetra-arsenic tetra-sulfide, suppressor of cytokine signaling 1 methylation was decreased while suppressor of cytokine signaling 1 expression was increased in U266 cells, along with the reduced phospho-Janus kinase 2 and phospho-signal transducer and activator of transcription 3 expressions. Then, suppressor of cytokine signaling 1 small interfering RNA enhanced the cell viability and phospho-Janus kinase 2 as well as phospho-signal transducer and activator of transcription 3 expressions in both tetra-arsenic tetra-sulfide treatment-free and tetra-arsenic tetra-sulfide-treated U266 cells. CONCLUSION: Tetra-arsenic tetra-sulfide exhibits good killing effect on multiple myeloma cells via repressing suppressor of cytokine signaling 1 methylation and downstream Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway, which might serve as a potential treatment option for multiple myeloma.


Assuntos
Antineoplásicos/farmacologia , Arsenicais/farmacologia , Mieloma Múltiplo/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Sulfetos/farmacologia , Proteína 1 Supressora da Sinalização de Citocina/metabolismo , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Humanos , Janus Quinase 2 , Metilação , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/genética , Mieloma Múltiplo/patologia , Proteína 1 Supressora da Sinalização de Citocina/genética
20.
Environ Sci Technol ; 53(23): 13648-13656, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31682413

RESUMO

Massive amounts of methyl [e.g., methylarsenate, MAs(V)] and aromatic arsenicals [e.g., roxarsone (4-hydroxy-3-nitrophenylarsonate, Rox(V)] have been utilized as herbicides for weed control and growth promotors for poultry and swine, respectively. The majority of these organoarsenicals degrade into more toxic inorganic species. Here, we demonstrate that the legume symbiont Sinorhizobium meliloti both reduces MAs(V) to MAs(III) and catalyzes sequential two-step reduction of nitro and arsenate groups in Rox(V), producing the highly toxic trivalent amino aromatic derivative 4-hydroxy-3-aminophenylarsenite (HAPA(III)). The existence of this process suggests that S. meliloti possesses the ability to transform pentavalent methyl and aromatic arsenicals into antibiotics to provide a competitive advantage over other microbes, which would be a critical process for the synthetic aromatic arsenicals to function as antimicrobial growth promoters. The activated trivalent aromatic arsenicals are degraded into less-toxic inorganic species by an MAs(III)-demethylating aerobe, suggesting that environmental aromatic arsenicals also undergo a multiple-step degradation pathway, in analogy with the previously reported demethylation pathway of the methylarsenate herbicide. We further show that an FAD-NADPH-dependent nitroreductase encoded by mdaB gene catalyzes nitroreduction of roxarsone both in vivo and in vitro. Our results demonstrate that environmental organoarsenicals trigger competition between members of microbial communities, resulting in gradual degradation of organoarsenicals and contamination by inorganic arsenic.


Assuntos
Anti-Infecciosos , Arsênico , Arsenicais , Fabaceae , Herbicidas , Roxarsona , Sinorhizobium meliloti , Animais , Antibacterianos , Suínos
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