DEFAR - Departamento de Farmácia
URI permanente desta comunidadehttp://www.hml.repositorio.ufop.br/handle/123456789/530
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Item Biological factors influencing As mobilization from an ancient mining region : in vitro studies.(2022) Santos, Alcylane Caldeira; Lopes, L. R.; Teixeira, Mônica CristinaOuro Preto city is located in the Iron Quadrangle, where Arsenic-bearing minerals are easily found; therefore, human exposure to As is a concern. The aim of this study was to assess the influence of organic matter (OM) and microbiota on As mobility. Soil samples were collected from deactivated gold mines to achieve this goal. Soil aliquots (5 g) were exposed to different extractant mixtures: CaCl2, 2.5 mmol −1 (A); CaCl2 + 5 g of proteic biomass - PB (B); CaCl2 + bacterial inoculum (C); CaCl2 + 5 g of PB + inoculum (D); and organic acid solution - OAS (0.1 mol−1) (E). Solubility tests were conducted at room temperature for 120 days (A–D) or 48 h (E). PB increased As mobility up to 600 times compared to that of the control group (A). As mobility in the presence of bacteria was slightly lower thus highlighting the effects of microbiota and OM on As mobilization. Principal component analyses indicated Ca, Fe, Mn, P, Mg, Sr, As, and Cd were the main contributing factors. In the presence of OM, Zn, Cu, Pb, Cd, As, and Cr were leached. The positive effect of OM and indigenous microorganisms on As mobility was confirmed, reinforcing the need to adopt preventive measures to avoid potential environmental damage due to ineffective management of urban and industrial waste deposition in such As-contaminated urban areas.Item Uma revisão sobre : tratamento biológico de drenagem de mina — cenário atualizado, perspectivas e recomendações de futuros trabalhos.(2021) Vieira, Bárbara Franco; Araújo, Juliana Calábria de; Teixeira, Mônica Cristina; Pereira, Josiane Caroline de SouzaRochas contendo sulfetos metálicos podem ser oxidadas em um processo catalisado por procariotos quimiolitoautotróficos ou Fe3+. A atividade mineradora acelera esse processo ao gerar resíduos contendo sulfetos metálicos com grande superfície de contato. O lixiviado resultante, conhecido como drenagem de mina (DM), é rico em sulfato, íons hidrogênio e contaminantes químicos inorgânicos como ferro (Fe), zinco (Zn), cádmio (Cd), manganês (Mn), níquel (Ni), arsênio (As) e alumínio (Al). Para remover tais poluentes, atualmente, o principal tratamento utilizado é a adição de reagentes alcalinos. Entretanto, esse método tem limitada eficiência, alto custo e gera grandes volumes de resíduos sólidos tóxicos de relativa solubilidade. Bactérias redutoras de sulfato (BRS) podem oxidar matéria orgânica com geração de sulfeto. Algumas vias metabólicas do processo consomem H+ neutralizando o pH. O sulfeto produzido pode reagir com contaminantes inorgânicos e precipitá-los, permitindo sua recuperação da fase líquida. O uso de subprodutos industriais e urbanos contendo diferentes fontes de carbono como doadores de elétrons no tratamento de DM tem sido investigado. Este artigo sumariza dados sobre as variáveis relevantes para a atividade microbiana durante o tratamento biológico de DM, analisando o atual cenário de pesquisas com fontes alternativas de carbono. Discute-se ainda novas fontes de matéria orgânica ainda não aplicadas para tratamento biológico de efluentes e que, sob aspectos de sustentabilidade, dos pontos de vista sustentável e econômico, podem ser usadas no tratamento de resíduos.Item Mechanisms of arsenic removal from simulated surface water based on As (III) retention on thiol chelating resins.(2021) Duarte, Graziele; Teixeira, Mônica Cristina; Olusegun, Sunday J.; Ciminelli, Virgínia Sampaio TeixeiraA novel system for arsenic speciation in the aqueous environment has been developed based on the high affinity of As(III) for the sulfhydryl groups present in thiol resins (R-S). The performance of tailor-made cartridges filled with the thiol resin was then compared with a commercial silica-based anion exchange cartridge with a qua- ternary ammonium group (R-N) typically used for As(V) speciation. Both were able to separate arsenic species efficiently, As(V) and As(III), within a broad pH range using flow rates of up to 5 ml min− 1 . The R-S resin was shown to be suitable for the inorganic arsenic speciation in aqueous systems containing calcium, magnesium, ferrous and ferric ions. The R-S selectivity for As(III) was affected only at sulfate or phosphate/As mass ratio > 500, in a behavior similar to R-N for As(V). The thiol resin’s selectivity for As(III) and its immobilization mechanism were investigated through X-ray Absorption Spectroscopy. At pH 5, each arsenic atom bounds to three sulfur atoms, with an As-S inter-atomic distance of 2.26 ± 0.01 Å, and a coordination number (CN) of 2.8 ± 0.3. The separation of the neutral As(III) species by a thiol resin presents itself as an alternative to the available anion exchange methods. The sorption of As(III) on the thiol resin followed a pseudo-second-order kinetic model and can be described by the Langmuir isotherm.Item Uma revisão sobre : tratamento biológico de drenagem de mina - cenário atualizado, perspectivas e recomendações de futuros trabalhos.(2021) Vieira, Bárbara Franco; Araújo, Juliana Calábria de; Teixeira, Mônica Cristina; Pereira, Josiane Caroline de SouzaRochas contendo sulfetos metálicos podem ser oxidadas em um processo catalisado por procariotos quimiolitoautotróficos ou Fe3+. A atividade mineradora acelera esse processo ao gerar resíduos contendo sulfetos metálicos com grande superfície de contato. O lixiviado resultante, conhecido como drenagem de mina (DM), é rico em sulfato, íons hidrogênio e contaminantes químicos inorgânicos como ferro (Fe), zinco (Zn), cádmio (Cd), manganês (Mn), níquel (Ni), arsênio (As) e alumínio (Al). Para remover tais poluentes, atualmente, o principal tratamento utilizado é a adição de reagentes alcalinos. Entretanto, esse método tem limitada eficiência, alto custo e gera grandes volumes de resíduos sólidos tóxicos de relativa solubilidade. Bactérias redutoras de sulfato (BRS) podem oxidar matéria orgânica com geração de sulfeto. Algumas vias metabólicas do processo consomem H+ neutralizando o pH. O sulfeto produzido pode reagir com contaminantes inorgânicos e precipitá-los, permitindo sua recuperação da fase líquida. O uso de subprodutos industriais e urbanos contendo diferentes fontes de carbono como doadores de elétrons no tratamento de DM tem sido investigado. Este artigo sumariza dados sobre as variáveis relevantes para a atividade microbiana durante o tratamento biológico de DM, analisando o atual cenário de pesquisas com fontes alternativas de carbono. Discute-se ainda novas fontes de matéria orgânica ainda não aplicadas para tratamento biológico de efluentes e que, sob aspectos de sustentabilidade, dos pontos de vista sustentável e econômico, podem ser usadas no tratamento de resíduos.Item Biorremediação de solos contaminados com arsênio por meio de lavagem de solo usando biossurfactantes.(2020) Coelho, Ricardo Silva; Teixeira, Mônica CristinaA mineração de ouro é uma das principais fontes de contaminação de arsênio (As) no Quadrilátero Ferrífero em Minas Gerais. O As é um elemento tóxico capaz de causar sérios danos à saúde humana. Com o objetivo de investigar formas mais ecológicas e igualmente eficientes para a remoção de As em solos, empregou-se a técnica de lavagem de solos (soil washing) com uso de extratos com biossurfactantes (BS) visando promover a mobilização do As contido em solo de mina de ouro abandonada. Para a produção dos extratos, foram selecionadas duas culturas mistas de bactérias produtoras de BS (MPCB e MPBR) tolerantes a alta concentração de arsênio (8 mg.L-1). Os tensoativos produzidos foram estáveis em ampla faixa de pH, 3-11; temperatura, 28–50°C e salinidade, 1-5% NaCl (p.v-1). Nos testes de lavagem de solo, em pH 11, as remoções de As obtidas com os extratos MPCB (14,01 e 13,72%) e MPBR (12,04 e 12,31%) foram superiores àquelas obtidas com soluções a 1% (p.v-1) dos surfactantes comerciais SDS (0,87 e 0,71%); saponina (0,57 e 0,55%) e lecitina de soja (2,05 e 2,63%). Os resultados dos testes em coluna foram igualmente influenciados pelo pH e pela proporção sólido:líquido. As maiores remoções de As: 25,43% (MPCB) 22,43% (MPBR) foram obtidas em pH 11, na proporção 1:40 (g.mL-1), após 10 ciclos de extração. Os extratos MPCB e MPBR removeram o As solúvel em água, os íons ligados ao carbonato e aqueles adsorvidos. Ambos os extratos tiveram comportamento semelhante ao ácido etilenodiaminotetracético (EDTA) e ao extrato de cultura microbiana comercial (GorduraKlin®).Item Arsenic contamination assessment in Brazil - past, present and future concerns : a historical and critical review.(2020) Teixeira, Mônica Cristina; Santos, Alcylane Caldeira; Fernandes, Carla da Silva; Ng, Jack ChakmengThis paper presents a summary of some relevant documents published during the last decades regarding arsenic contamination in Brazil until December 2018, including scientific papers, reports and regulatory documents. Natural and anthropogenic arsenic sources were covered, excluding those related to agriculture. International “key” documents related to arsenic contamination were used to support the discussion and comparative analysis. This paper aims: (a) to summarize and discuss some available data (including Portuguese written documents) concerning arsenic contamination in Brazil, mainly geographical, geological, geochemical, environmental and health studies; (b) to critically review the published studies comparing their main findings; (c) to describe and compare ancient and recent contamination events; and (d) to highlight key knowledge gaps, and identify promising areas for future researches. The arsenic contamination scenario in Brazil results not only from mining. Natural or anthropogenic emissions caused by great magnitude phenomena as flooding, erosion, landslide and, water scarcity equally impact arsenic mobilization/immobilization equilibria. Our literature review demonstrates that arsenic contamination of soils, sediments and water sources is observed at least at three of the five geographically defined Brazilian regions (Northern, Southern and, Southeastern regions). Arsenic enriched soils, and waters naturally occur all around the country and anthropogenic activities have been the main contributory factor to the environmental contamination since the 18th Century. Geogenic materials (topsoil and mining tailings), and water samples could contain extremely high arsenic concentrations, i.e. 21,000 mg kg−1 or 1,700,000 μg L−1 , respectively, have been found mainly at the “Iron Quadrangle”. Moreover, if we consider both the Brazilian and international parameters, the health risks associated with the human exposition to arsenic are of significant concern. For those reasons, constant monitoring of As contaminated areas in Brazil is mandatory. Furthermore, it is necessary to learn from the mistakes made in the past in order to prevent or minimize future problems.Item Aspectos farmacológicos da ivermectina e seu potencial uso no tratamento da COVID-19.(2020) Pedroso, Luana Amaral; Binda, Nancy Scardua; Teixeira, Mônica Cristina; Guimarães, Andrea GrabeA ivermectina é um fármaco antiparasitário de amplo espectro largamente utilizado em medicina humana e veterinária. É o medicamento de escolha para tratamento da oncocercose, além de ser aprovada para o tratamento de filariose linfática, estrongiloidíase, ascaridíase, escabiose e pediculose. Estudos avaliam a capacidade antitumoral, antibacteriana e antiviral da ivermectina, além de seus benefícios no tratamento de doenças metabólicas. Atualmente o grande interesse global em relação à ivermectina recai sobre o seu potencial no tratamento da COVID-19. Neste estudo foram descritos os aspectos gerais sobre a farmacologia, as características físico-químicas, os protocolos de tratamento, os aspectos de segurança e a toxicologia da ivermectina, bem como as propriedades que poderiam corroborar ou não com seu uso no tratamento da COVID-19. Foi realizada uma revisão narrativa baseada em publicações da base de dados Pubmed utilizando descritores como ivermectin, pharmacology, therapeutic use, saffety, toxicity e Covid-19. Observou-se que além da ampla indicação terapêutica, a ivermectina possui um extenso uso off-label. De modo geral, considera-se que a atividade antiviral da ivermectina seja devido à sua capacidade em estimular a resposta imune do paciente e em inibir a replicação viral. Todavia, a sua segurança terapêutica para a prevenção e tratamento da COVID-19 ainda não foi determinada, visto que as concentrações efetivas encontradas nos estudos in vitro indicam o uso de concentrações superiores àquelas aprovadas para humanos e os efeitos adversos podem ser potencializados. Até o momento não existem protocolos de tratamento com esse medicamento para a COVID-19 e a ANVISA apoia o uso da ivermectina apenas para indicações terapêuticas previamente registradas.Item Simultaneous removal of sulfate and arsenic using immobilized nontraditional SRB mixed culture and alternative low-cost carbon sources.(2017) Matos, Letícia Paiva de; Costa, Patrícia Freitas; More, Mariana; Gomes, Paula Cristine Silva; Silva, Silvana de Queiroz; Gurgel, Leandro Vinícius Alves; Teixeira, Mônica CristinaThis study was designed to obtain simultaneous sulfate (SO4 2−) and As(III) ions removal by non-traditional sulfate-reducing bacteria (SRB) growing in the presence of a protein biomass (PCF), a solid residual material produced by the poultry industry. Microbial cells and PCF were immobilized into calcium alginate beads to reduce mass losses. Microbial consortium efficiency was tested under different operational conditions: sodium lactate, glycerol and PCF as carbon sources; increasing As(III) content; acidic pH (5.0). Microbial diversity was evaluated by PCR-DGGE. Pantoea agglomerans, Enterobacter sp., Citrobacter sp., Cupriavidus metallidurans, Ralstonia sp. and Burkholderia cepacia were found. With the aim to obtain SO4 2− and As(III) simultaneous removal, three semi-continuous up-flow reactors were constructed and operated for more than 100 days to prove their feasibility and reliability. Both SO4 2− and As(III) ions were removed with 74.8% and 80% efficiency, respectively. Solid products were characterized by SEM-EDX, confirming PCF and non-traditional SRB roles during arsenic immobilization. Arsenic/sulfur compounds (possibly As/sulfides) were produced by reaction between As(III) and biogenic sulfide. Microbial consortium proved its ability of growing in an acidic environment without losing its sulfate reductive capacity by using glycerol and PCF as alternative carbon sources and tap water as micronutrients source. The non-traditional SRB culture removed both SO4 2− and As(III) ions simultaneously, with no prior step needed to guarantee As(III) oxidation to As(V). Two different mechanisms could be involved: (i) precipitation as arsenic sulfide or, (ii) adsorption onto PCF/cells calcium alginate beads.Item Development and validation of an analytical method for quantification of arsenic and antimony in liposomes using inductively coupled plasma-optical emission spectrometry.(2013) Reis, Priscila Gomes dos; Abreu, Adriana Trópia de; Guimarães, Andrea Grabe; Teixeira, Mônica Cristina; Souza, Jacqueline de; Barcellos, Neila Marcia SilvaArsenic and antimony compounds are used to treat endemic diseases, such as cancer, leishmaniasis, and schistosomiasis, in spite of their toxicity. Several studies seeking the development and characterization of nanocarrier systems such as liposomes are being carried out with the aim of developing new drug delivery systems and minimizing the toxicity of these drugs. However, the lack of reference methods to quantify these semimetals within a liposomal matrix hinders the QC of these formulations. Therefore, the validation of an analytical method for arsenic and antimony quantification in liposomal matrix by inductively coupled plasma-optical emission spectrometry is presented here. The linearity, specificity, LOD, LOQ, accuracy, and precision were determined according to the International Conference on Harmonization norms and the Brazilian Health Surveillance Agency (Resolution 899). The LOD values were 0.02 and 0.06 mg/L for antimony and arsenic, respectively. The LOQ for both was 3.0 mg/L, with an adequate accuracy within 98.26 and 101.32% for different levels of antimony and 99.98 and 100.36% for arsenic. Precision (CV) was lower than 5.0%. The developed and validated method was shown to be reproducible for quantification of arsenic and antimony in liposome pharmaceutical dosage forms.Item Nickel, manganese and copper removal by a mixed consortium of sulfate reducing bacteria at a high COD/sulfate ratio.(2014) Barbosa, Leonardo de Paiva; Costa, Patrícia Freitas; Bertolino, Sueli Moura; Silva, Júlio César Cardoso da; Cota, Renata Guerra de Sá; Leão, Versiane Albis; Teixeira, Mônica CristinaThe use of sulfate-reducing bacteria (SRB) in passive treatments of acidic effluents containing heavy metals has become an attractive alternative biotechnology. Treatment efficiency may be linked with the effluent conditions (pH and metal concentration) and also to the amount and nature of the organic substrate. Variations on organic substrate and sulfate ratios clearly interfere with the biological removal of this ion by mixed cultures of SRB. This study aimed to cultivate a mixed culture of SRB using different lactate concentrations at pH 7.0 in the presence of Ni, Mn and Cu. The highest sulfate removal efficiency obtained was 98 %, at a COD/sulfate ratio of 2.0. The organic acid analyses indicated an acetate accumulation as a consequence of lactate degradation. Different concentrations of metals were added to the system at neutral pH conditions. Cell proliferation and sulfate consumption in the presence of nickel (4, 20 and 50 mg l-1), manganese (1.5, 10 and 25 mg l-1) and copper (1.5, 10 and 25 mg l-1) were measured. The presence of metals interfered in the sulfate biological removal however the concentration of sulfide produced was high enough to remove over 90 % of the metals in the environment. The molecular characterization of the bacterial consortium based on dsrB gene sequencing indicated the presence of Desulfovibrio desulfuricans, Desulfomonas pigra and Desulfobulbus sp. The results here presented indicate that this SRB culture may be employed for mine effluent bioremediation due to its potential for removing sulfate and metals, simultaneously.