RESUMO

Intestinal ischemia is a vascular emergency that arises when blood flow to the intestine is compromised. Reperfusion is necessary to restore intestinal function but might lead to local and systemic inflammatory responses and bacterial translocation, with consequent multiple organ dysfunction syndrome (MODS). During reperfusion occurs production of reactive oxygen species. These species contribute to intestinal injury through direct toxicity or activation of inflammatory pathways. Fullerol is a nanacomposite which has been shown to act as reactive oxygen species and reactive nitrogen species (RNS) scavengers. Thus, our aim was to evaluate whether Fullerol confer anti-inflammatory activity during intestinal ischemia and reperfusion (IIR). Intestinal ischemia was induced by total occlusion of the superior mesenteric artery. Groups were treated with vehicle or Fullerol 10 min before reperfusion. Mice were euthanized after 6 h of reperfusion, and small intestines were collected for evaluation of plasma extravasation, leukocyte influx, cytokine production and histological damage. Bacterial translocation to the peritoneal cavity and reactive oxygen and nitrogen species production by lamina propria cells were also evaluated. Our results showed that treatment with Fullerol inhibited bacterial translocation to the peritoneal cavity, delayed and decreased the lethality rates and diminished neutrophil influx and intestinal injury induced by IIR. Reduced severity of reperfusion injury in Fullerol-treated mice was associated with blunted reactive oxygen and nitrogen species production in leukocytes isolated from gut lamina propria and decreased production of pro-inflammatory mediators. Thus, the present study shows that Fullerol is a potential therapy to treat inflammatory bowel disorders associated with bacterial translocation, such as IIR.

Assuntos

Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Fulerenos/farmacologia , Intestinos/irrigação sanguínea , Intestinos/efeitos dos fármacos , Isquemia Mesentérica/tratamento farmacológico , Nanocompostos , Traumatismo por Reperfusão/prevenção & controle , Animais , Translocação Bacteriana/efeitos dos fármacos , Citocinas/metabolismo , Modelos Animais de Doenças , Mediadores da Inflamação/metabolismo , Intestinos/microbiologia , Intestinos/patologia , Masculino , Isquemia Mesentérica/metabolismo , Isquemia Mesentérica/microbiologia , Isquemia Mesentérica/patologia , Camundongos Endogâmicos C57BL , Infiltração de Neutrófilos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Permeabilidade , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/microbiologia , Traumatismo por Reperfusão/patologia , Índice de Gravidade de Doença

RESUMO

Visceral leishmaniasis (VL) is a systemic parasitic disease that leads to high rates of morbidity and mortality in humans worldwide. There is a great need to develop new drugs and novel strategies to make chemotherapy for this disease more efficacious and well tolerated. Recent reports on the immunomodulatory effects and the low toxicity of the spherical carbon nanostructure fullerol led us to investigate in vitro and in vivo antileishmanial activity in free and encapsulated forms in liposomes. When assayed against intramacrophagic Leishmania amastigotes, fullerol showed a dose-dependent reduction of the infection index with IC50 of 0.042 mg/mL. When given daily by i.p. route for 20 days (0.05 mg/kg/d) in a murine model of acute VL, fullerol promoted significant reduction in the liver parasite load. To improve the delivery of fullerol to the infection sites, liposomal formulations were prepared by the dehydration-rehydration method. When evaluated in the acute VL model, liposomal fullerol (Lip-Ful) formulations given i.p. at 0.05 and 0.2 mg/kg with 4-days intervals were more effective than the free form, with significant parasite reductions in both liver and spleen. Lip-Ful at 0.2 mg/kg promoted complete parasite elimination in the liver. The antileishmanial activity of Lip-Ful was further confirmed in a chronic model of VL. Lip-Ful was also found to induce secretion of pro-inflammatory TNF-α, IFN-γ and IL-1ß cytokines. In conclusion, this work reports for the first time the antileishmanial activity of fullerol and introduces an innovative approach for treatment of VL based on the association of this nanostructure with liposomes.

Assuntos

Fulerenos/farmacologia , Leishmania infantum/efeitos dos fármacos , Leishmania mexicana/efeitos dos fármacos , Leishmaniose Visceral/tratamento farmacológico , Lipídeos/química , Fígado/parasitologia , Macrófagos Peritoneais/parasitologia , Tripanossomicidas/farmacologia , Animais , Citocinas/sangue , Modelos Animais de Doenças , Composição de Medicamentos , Feminino , Fulerenos/química , Mediadores da Inflamação/sangue , Leishmania infantum/crescimento & desenvolvimento , Leishmania mexicana/crescimento & desenvolvimento , Leishmaniose Visceral/sangue , Leishmaniose Visceral/parasitologia , Lipossomos , Fígado/metabolismo , Mesocricetus , Camundongos Endogâmicos BALB C , Nanopartículas , Carga Parasitária , Tripanossomicidas/química

RESUMO

Water treatment plants (WTP) in the City of Manaus, Brazil, generate tons of sludge daily, which are then disposed of in landfills and main watercourses, particularly two important Amazonian Rivers: the blackwater Negro River and the pale sandy-colored water Solimões River. Because WTP-based sludges are rich in silicon and aluminum, they have been employed in the synthesis of geopolymers - alkaline activated inorganic polymers consisting of silicate and aluminosilicate chains. This paper reports the results of a geopolymeric synthesis process in which calcined sludge was explored as a source of silica and alumina. In this research, a laboratory testing program was developed to characterize the waste material generated from a water treatment plant in Manaus, whose intake water is influenced by the above referred rivers. Sample preparation involved kiln drying at 110 °C for 8 h, grinding in ball mill for 2 h, and calcination at 750 °C for 6 h. The calcined sludge was used as precursor, and potassium hydroxide added as activating alkali. Two geopolymers, one from each sludge source, were prepared following identical procedures. The chemical, compositional, morphological, thermal and mechanical properties of the fresh and hardened geopolymers were characterized. The geopolymers reached uniaxial compressive strengths of over 50 MPa at 28 days. Calcination conveyed more refined properties to the sludge-based geopolymers, akin to metakaolin-based geopolymers. The results presented herein support the technical feasibility of geopolymer synthesis in the lab scale.

Assuntos

Cinza de Carvão , Purificação da Água , Brasil , Força Compressiva , Esgotos

RESUMO

OBJETIVO: Descrever um modelo de treinamento de baixo custo de dissecção e acesso vascular utilizando língua bovina. MÉTODOS: Foram utilizadas dez línguas de boi para confecção de simuladores. Inicialmente, o corpo da língua foi dissecado, separando as camadas epitelial e muscular, e o pedículo vascular foi destacado da base da língua. A artéria principal da língua foi, então, cateterizada e conectada a uma seringa, sendo, em seguida, fixada à porção muscular. Após, para simular o tecido celular subcutâneo, foi confeccionada uma pasta amarela gelatinosa, que foi posicionada de modo a cobrir a extensão do pedículo vascular por inteiro. Por fim, a camada epitelial da língua foi reposicionada sob a camada muscular, por meio de sutura contínua. Para avaliar o modelo, foram observados o tempo de confecção do modelo, sua durabilidade, seu custo e o número de vezes que pôde ser usado. RESULTADOS: O tempo médio para confecção do modelo foi de 15,82±2,45 minutos, com durabilidade de 20 dias sob refrigeração. O custo médio foi de R$25,00, podendo ser utilizado, em média, por 3,8±0,63 vezes. Não houve falhas na montagem do modelo. CONCLUSÃO: O modelo de língua de boi se mostrou viável e de fácil aplicação para o treinamento de técnica cirúrgica de dissecção vascular. (AU)

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OBJECTIVE: To describe a low cost training model for dissection and vascular access using a bovine tongue. METHODS: Ten bovine tongues were used to build simulators. First, the body of the tongue was dissected, with its epithelial layer being separated from the muscular layer, and the vascular pedicle was detached from the base of the tongue. The tongue main artery was then catheterized and connected to a syringe, and subsequently fixed to the muscle layer. Then, the entire vascular pedicle was covered with a yellow gelatinous paste to simulate the subcutaneous tissue. Finally, the epithelial layer was repositioned above the muscle layer through continuous suture. To evaluate the model, 4 variables were considered: 1) time for building the model, 2) its durability, 3) its cost, 4) number of times that it could be used. RESULTS: The mean time to make the model was 15.82 ±2.45 minutes, with a durability of 20 days under refrigeration. The mean cost of each model was U$10.00, and could be used about 3.8±0.63 times. There were no fails to build the model. CONCLUSIONS: The model with a bovine tongue proved to be viable and easy to be applied for training the surgical technique of vascular dissection. (AU)

Assuntos

Animais , Cateterismo/métodos , Dissecação/educação , Treinamento por Simulação/métodos , Língua/cirurgia , Bovinos , Competência Clínica , Modelos Animais , Dissecação/métodos , Educação Médica/métodos

RESUMO

ABSTRACT Introduction: Food is a key factor both in prevention and in promoting human health. Among the functional food are highlighted probiotics and prebiotics. Patent databases are the main source of technological information about innovation worldwide, providing extensive library for research sector. Objective: Perform mapping in the main patent databases about pre and probiotics, seeking relevant information regarding the use of biotechnology, nanotechnology and genetic engineering in the production of these foods. Method: Electronic consultation was conducted (online) in the main public databases of patents in Brazil (INPI), United States (USPTO) and the European Patent Bank (EPO). The research involved the period from January 2014 to July 2015, being used in the title fields and summary of patents, the following descriptors in INPI "prebiotic", "prebiotic" "probiotics", "probiotic" and the USPTO and EPO: "prebiotic", "prebiotics", "probiotic", "probiotics". Results: This search haven't found any deposit at the brazilian patents website (INPI) in this period; US Patent &Trademark Office had registered 60 titles in patents and the European Patent Office (EPO) showed 10 documents on the issue. Conclusion: Information technology offered by genetic engineering, biotechnology and nanotechnology deposited in the form of titles and abstracts of patents in relation to early nutritional intervention as functional foods, has increasingly required to decrease the risks and control the progression of health problems. But, the existing summaries, although attractive and promising in this sense, are still incipient to recommend them safely as a therapeutic tool. Therefore, they should be seen more as diet elements and healthy lifestyles.

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RESUMO Introdução: A alimentação é fator primordial tanto na prevenção quanto na promoção para a saúde humana. Dentre os alimentos funcionais destacam-se os probióticos e prebióticos. Os bancos de dados de patentes representam a maior fonte de informação tecnológica acerca de inovação em nível mundial, provendo vasta biblioteca para o setor de pesquisa. Objetivo: Realizar mapeamento nas principais bases de dados de patentes relacionada aos pré e probióticos buscando informações relevantes com relação ao uso da biotecnologia, nanotecnologia e engenharia genética na produção desses alimentos. Método: Foi realizada consulta eletrônica (online) nas principais bases de dados públicas de patentes do Brasil (INPI), Estados Unidos da América (USPTO) e o Banco de Patentes Europeu (EPO). A pesquisa envolveu o período de janeiro de 2014 a julho 2015, sendo utilizado nos campos de título e resumo das patentes, os seguintes descritores no INPI: "prebiótico", "prebióticos" "probiótico", "probióticos" e no USPTO e EPO: "prebiotic", "prebiotics", "probiotic", "probiotics" Resultados: Não foram observados, no INPI, depósitos de residentes (empresas ou universidades). Já no USPTO foram detectados 60 depósitos e no EPO 10 títulos de interesse à pesquisa. Conclusão: A tecnologia da informação ofertada pela engenharia genética, biotecnologia e nanotecnologia depositada na forma de títulos e resumos das patentes em relação à intervenção nutricional precoce como alimentos funcionais, tem cada vez mais pretendido diminuir os riscos e controlar a progressão de agravos à saúde. Mas, os resumos existentes, embora atraentes e promissores neste sentido, ainda são incipientes para recomendá-los de forma segura como ferramenta terapêutica. Portanto, devem ser encarados mais como integrantes de dieta e estilos de vida saudáveis.

Assuntos

Humanos , Patentes como Assunto , Sistema de Registros , Probióticos , Prebióticos , Informática Médica , Brasil , Bases de Dados Factuais , Fenômenos Fisiológicos da Nutrição

RESUMO

Nanohybrids of enriched (6,5) single-walled semiconducting carbon nanotubes (E-SWCNTs) and porphyrin can be used synergistically as photodynamic therapy (PDT) agents. The efficiency of different porphyrins within the nanohybrids was investigated and compared with results obtained from porphyrins in previous studies. Reactive oxygen species singlet oxygen (1)O2 and for the first time hydroxyl radical ˙OH generation by the nanohybrids under illumination were detected by electron paramagnetic resonance using spin trapping molecules TEMP and PBN. Based on the analysis, we improve the modelling of charge transport within the nanohybrids, which is also detected by Raman scattering. It is shown that the 5,10,15,20-tetrakis(4-trimethylammoniumphenyl)porphyrin [H2TTMAPP(OTs)4] and E-SWCNT form very efficient nanohybrids for PDT applications in the visible spectral range.

RESUMO

Irinotecan is a useful chemotherapeutic agent for the treatment of several solid tumors. However, this therapy is associated with side effects, including leukopenia and mucositis. Reactive oxygen species (ROS) activate inflammatory pathways and contribute to Irinotecan-induced mucositis. Fullerol is a nanocomposite with anti-oxidant properties that may reduce tissue damage after inflammatory stimuli. In this paper, the effects of Fullerol and mechanisms of protection were investigated in a model of Irinotecan-induced mucositis. Mucositis was induced by an injection of Irinotecan per 4 days in C57BL/6. Fullerol or a vehicle was injected every 12h. On day 7, the intestines were removed to evaluate histological changes, leukocyte influx, and the production of cytokines and ROS. Irinotecan therapy resulted in weight loss, an increased clinical score and intestinal injury. Treatment with Fullerol attenuated weight loss, decreased clinical score and intestinal damage. Irinotecan also induced increased ROS production in enterocytes, oxidative stress, IL-1ß production, neutrophil and eosinophil influx in the ileum. Fullerol treatment decreased production of ROS in the enterocytes, oxidative stress, IL-1ß production, neutrophil and eosinophil influx in the ileum. Irinotecan therapy also induced leukopenia in an ROS-dependent manner because leukopenia reverted in WT mice treated with Fullerol or Apocynin or in Gp91phox(-/-) mice. Mice treated with Irinotecan presented less melanoma tumor growth compared to the control group. Fullerol does not interfere in the anti-tumor action of Irinotecan. Fullerol has a great pharmacology potential to decreases the severity of mucositis and of leukopenia during chemotherapy treatment.

Assuntos

Antineoplásicos Fitogênicos/efeitos adversos , Camptotecina/análogos & derivados , Fulerenos/uso terapêutico , Leucopenia/prevenção & controle , Mucosite/prevenção & controle , Nanocompostos/uso terapêutico , Animais , Antineoplásicos Fitogênicos/uso terapêutico , Camptotecina/efeitos adversos , Camptotecina/uso terapêutico , Glutationa/metabolismo , Íleo/efeitos dos fármacos , Íleo/metabolismo , Íleo/patologia , Interleucina-1beta/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Irinotecano , Leucopenia/induzido quimicamente , Masculino , Melanoma/tratamento farmacológico , Melanoma/patologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mucosite/induzido quimicamente , Estresse Oxidativo/efeitos dos fármacos , Peroxidase/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Carga Tumoral/efeitos dos fármacos

RESUMO

Introduction: Food is a key factor both in prevention and in promoting human health. Among the functional food are highlighted probiotics and prebiotics. Patent databases are the main source of technological information about innovation worldwide, providing extensive library for research sector. Objective: Perform mapping in the main patent databases about pre and probiotics, seeking relevant information regarding the use of biotechnology, nanotechnology and genetic engineering in the production of these foods. Method: Electronic consultation was conducted (online) in the main public databases of patents in Brazil (INPI), United States (USPTO) and the European Patent Bank (EPO). The research involved the period from January 2014 to July 2015, being used in the title fields and summary of patents, the following descriptors in INPI "prebiotic", "prebiotic" "probiotics", "probiotic" and the USPTO and EPO: "prebiotic", "prebiotics", "probiotic", "probiotics". Results: This search haven't found any deposit at the brazilian patents website (INPI) in this period; US Patent &Trademark Office had registered 60 titles in patents and the European Patent Office (EPO) showed 10 documents on the issue. Conclusion: Information technology offered by genetic engineering, biotechnology and nanotechnology deposited in the form of titles and abstracts of patents in relation to early nutritional intervention as functional foods, has increasingly required to decrease the risks and control the progression of health problems. But, the existing summaries, although attractive and promising in this sense, are still incipient to recommend them safely as a therapeutic tool. Therefore, they should be seen more as diet elements and healthy lifestyles.

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Introdução: A alimentação é fator primordial tanto na prevenção quanto na promoção para a saúde humana. Dentre os alimentos funcionais destacam-se os probióticos e prebióticos. Os bancos de dados de patentes representam a maior fonte de informação tecnológica acerca de inovação em nível mundial, provendo vasta biblioteca para o setor de pesquisa. Objetivo: Realizar mapeamento nas principais bases de dados de patentes relacionada aos pré e probióticos buscando informações relevantes com relação ao uso da biotecnologia, nanotecnologia e engenharia genética na produção desses alimentos. Método: Foi realizada consulta eletrônica (online) nas principais bases de dados públicas de patentes do Brasil (INPI), Estados Unidos da América (USPTO) e o Banco de Patentes Europeu (EPO). A pesquisa envolveu o período de janeiro de 2014 a julho 2015, sendo utilizado nos campos de título e resumo das patentes, os seguintes descritores no INPI: "prebiótico", "prebióticos" "probiótico", "probióticos" e no USPTO e EPO: "prebiotic", "prebiotics", "probiotic", "probiotics". Resultados: Não foram observados, no INPI, depósitos de residentes (empresas ou universidades). Já no USPTO foram detectados 60 depósitos e no EPO 10 títulos de interesse à pesquisa. Conclusão: A tecnologia da informação ofertada pela engenharia genética, biotecnologia e nanotecnologia depositada na forma de títulos e resumos das patentes em relação à intervenção nutricional precoce como alimentos funcionais, tem cada vez mais pretendido diminuir os riscos e controlar a progressão de agravos à saúde. Mas, os resumos existentes, embora atraentes e promissores neste sentido, ainda são incipientes para recomendá-los de forma segura como ferramenta terapêutica. Portanto, devem ser encarados mais como integrantes de dieta e estilos de vida saudáveis.

Assuntos

Patentes como Assunto , Prebióticos , Probióticos , Sistema de Registros , Brasil , Bases de Dados Factuais , Humanos , Informática Médica , Fenômenos Fisiológicos da Nutrição

RESUMO

Graft versus host disease (GVHD) is an immunological disorder triggered by bone marrow transplantation that affects several organs, including the gastrointestinal tract and liver. Fullerenes and their soluble forms, fullerols, are nanocomposites with a closed symmetrical structure with anti-inflammatory and anti-oxidant properties. The present study evaluated the effects of treatment with the fullerol (C60(OH)18-20) in the development and pathogenesis of GVHD in a murine model. Mice with experimental GVHD that were treated with the fullerol showed reduced clinical signs of disease and mortality compared with untreated mice. Treatment with the fullerol decreased the hepatic damage associated with reduced hepatic levels of reactive oxygen species, pro-inflammatory cytokines and chemokines (IFN-γ TNF-α, CCL2, CCL3 and CCL5) and reduced leukocyte accumulation. The amelioration of GVHD after treatment with the fullerol was also associated with reduced intestinal lesions and consequent bacterial translocation to the blood, liver and peritoneal cavity. Moreover, the fullerol treatment alleviated the GVHD while preserving effects of the graft against a leukemia cell line (GFP+P815). In summary, the fullerol was effective in reducing the GVHD inflammatory response in mice and may suggest novel ways to treat this disease.

Assuntos

Antineoplásicos/química , Fulerenos/química , Doença Enxerto-Hospedeiro/terapia , Nanocompostos/química , Animais , Transplante de Medula Óssea/efeitos adversos , Linhagem Celular Tumoral , Modelos Animais de Doenças , Inflamação , Fígado/patologia , Macrófagos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Neutrófilos/citologia , Espécies Reativas de Oxigênio/metabolismo

RESUMO

Nanomaterials (NM) industry had grown in the last decade, although there are few studies concerning its potential toxicity effects on aquatic organisms. In this study the freshwater zebrafish (Danio rerio) was exposed to two kinds of carbon NM, single-wall carbon nanotubes (SWCNT) and fullerenol [C60(OH)18-22(OK4)] to analyze oxidative stress responses on fish brain. Adult zebrafish (mean mass: 0.52±0.01g) were submitted to intraperitoneal injections of SWCNT suspension and fullerenol solution (30mg/kg of fish), receiving one or two doses with a time interval of 24h. Results showed that total antioxidant capacity was lowered in brains of fish exposed 24h to fullerenol when compared to those from SWCNT treatment (p<0.05). After 48h, fullerenol induced higher expression of both catalytic and regulatory subunits of enzyme glutamate cysteine ligase when compared to control group (p<0.05), indicating an antioxidant behavior. In vitro assays showed a dual effect of SWCNT, since a pro-oxidant behavior was observed at low concentrations (0.1 and 1.0mg/L) and an antioxidant one at the highest concentration (10.0mg/L). Few biological responses were altered by this NM: decrease in total antioxidant capacity and induction of the expression of the transcription factor Nrf2 when compared to control group.

Assuntos

Antioxidantes/metabolismo , Encéfalo/efeitos dos fármacos , Fulerenos/administração & dosagem , Nanotubos de Carbono/química , Animais , Domínio Catalítico , Fulerenos/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Glutamato-Cisteína Ligase/metabolismo , Fator 2 Relacionado a NF-E2/biossíntese , Estresse Oxidativo , Espécies Reativas de Oxigênio , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/biossíntese

RESUMO

Hypericin is a photosensitizer with promising applications in photodynamic therapy (PDT) for cancer and infectious diseases treatments. Herein, we present a basic research study of L-diphenylalanine micro/nanotubes (FF-NTs) functionalized with hypericin. The system has special properties according to the hypericin concentration, with direct consequences on both morphological and photophysical behaviors. A clear dependence between the size of the tubes and the concentration of hypericin is revealed. The generation of reactive oxygen species (ROS) is found to be improved by ∼57% in the presence of FF-NTs, as indirectly measured from the absorbance profile of 1,3-diphenylisobenzofuran (DPBF). In addition, when hypericin appears conjugated with FF-NTs, the characteristic fluorescence lifetime is significantly boosted, demonstrating the role of FF-NTs to enhance the photophysical properties and stabilizing the fluorophore in excited states. Electron paramagnetic resonance allows the proposition of a mechanism for the generation of ROS. Molecular dynamics simulations bring new insights into the interaction between hypericin and peptide assemblies, suggesting the spatial organization of the fluorophore onto the surface of the supramolecular structures as a key element to improve the photophysical properties reported here.

Assuntos

Nanotubos , Peptídeos/química , Perileno/análogos & derivados , Antracenos , Microscopia Eletrônica de Varredura , Perileno/química , Difração de Raios X

RESUMO

Bi-stable molecular systems presenting valence tautomerism are associated with the development of new functional materials, which can be used for applications in organic electric conductors, optoelectronic and molecular magnetic devices. The properties of these materials can be adjusted with slight chemical changes and can be induced by external stimuli. Typical examples of valence tautomer compounds are coordination complexes of Co and o-dioxolene ligands, notably quinone like ones. In the search for a new class of cobalt complexes presenting valence tautomerism we report herein the synthesis and characterization of five new coordination compounds of cobalt and 2-hydroxy-1,4-naphthoquinone (lawsone or shortly Law). Complexes [Co(Law)2(im)2]·C6H5CH3 (1), [Co(Law)2(py)2]·CH3OH (2), [Co(Law)2(phen)]·(C4H8O)2 (3), [Co(Law)2(2,2-bpy)]·C6H5CH3 (4) and [Co(Law)2(2,2-bpy)] (5) were synthesized and fully characterized by X-ray diffraction and EPR techniques in a wide range of temperatures and under illumination. Despite presenting similar molecular and geometry packing of the valence tautomer complexes of cobalt and o-dioxolenes, neither structural nor electronic evidence of valence tautomerism could be found in the Co and lawsone complexes.

RESUMO

Studies concerning the impact of nanomaterials, especially fullerene (C(60) ), in fresh water environments and their effects on the physiology of aquatic organisms are still scarce and conflicting. We aimed to assess in vitro effects of fullerene in brain and gill homogenates of carp Cyprinus carpio, evaluating redox parameters. A fullerene suspension was prepared by continued stirring under fluorescent light during two months. The suspension concentration was measured by total carbon content and ultraviolet-visible spectroscopy nephelometry. Characterization of C(60) aggregates was performed with an enhanced dark-field microscopy system and transmission electronic microscopy. Organ homogenates were exposed during 1, 2, and 4 h under fluorescent light. Redox parameters evaluated were reduced glutathione and oxidized glutathione, cysteine and cystine, total antioxidant capacity; activity of the antioxidant enzymes glutathione S-transferase and glutathione reductase (GR), and lipid peroxidation (TBARS assay). Fullerene induced a significant increase (p < 0.05) in lipid peroxidation after 2 h in both organs and reduced GR activity after 1 h (gills) and 4 h (brain) and antioxidant capacity after 4 h (brain). Levels of oxidized glutathione increased in the brain at 1 h and decreased at 2 h as well. Given these results, it can be concluded that C(60) can induce redox disruption via thiol/disulfide pathway, leading to oxidative damage (higher TBARS values) and loss of antioxidant competence.

Assuntos

Encéfalo/efeitos dos fármacos , Carpas/metabolismo , Fulerenos/farmacologia , Brânquias/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Encéfalo/enzimologia , Cisteína/metabolismo , Brânquias/enzimologia , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/farmacologia

RESUMO

In consequence of their growing use and demand, the inevitable environmental presence of nanomaterials (NMs) has raised concerns about their potential deleterious effects to aquatic environments. The carbon NM fullerene (C60), which forms colloidal aggregates in water, and its water-soluble derivative fullerol (C60(OH)18₋22), which possesses antioxidant properties, are known to be photo-excited by ultraviolet (UV) or visible light. To investigate their potential hazards to aquatic organisms upon exposure to UV sunlight, this study analyzed (a) the in vitro behavior of fullerene and fullerol against peroxyl radicals (ROO) under UV-A radiation and (b) the effects of these photo-excited NMs on oxidative stress parameters in functional gills extracted from the fish Cyprinus carpio (Cyprinidae). The variables measured were the total antioxidant capacity, lipid peroxidation (TBARS), the activities of the antioxidant enzymes glutathione reductase (GR) and glutamate cysteine ligase (GCL), and the levels of the non-enzymatic antioxidant glutathione (GSH). The obtained results revealed the following: (1) both NMs behaved in vitro as antioxidants against ROO in the dark and as pro-oxidants in presence of UV-A, the latter effect being reversed by the addition of sodium azide, which is a singlet oxygen (¹O2) quencher; (2) fullerene induced toxicity with or without UV-A incidence, with a significant (p<0.05) increase in lipid peroxidation (with greater damage under illumination), a decrease in GCL activity, and the depletion of GSH stocks (under illumination), all of which were attributed to ¹O2 generation; and (3) fullerol also decreased GCL activity and GSH formation (p<0.05) but without lipid damage. The overall results show that fullerene can be toxic with or without light incidence, whereas UV radiation seems to play a key role in the environmental toxicity of carbon NMs through ¹O2 formation.

Assuntos

Carpas , Fulerenos/toxicidade , Brânquias/efeitos dos fármacos , Brânquias/efeitos da radiação , Nanoestruturas/toxicidade , Animais , Glutamato-Cisteína Ligase/metabolismo , Glutationa/metabolismo , Peroxidação de Lipídeos , Substâncias Reativas com Ácido Tiobarbitúrico , Raios Ultravioleta , Poluentes Químicos da Água/toxicidade

RESUMO

PURPOSE: To compare the intraocular pressure (IOP) pre and post LASIK, correlating it to changes in central corneal thickness (CCT) and average simulated keratometry (K), as well as verifying the results of a corrective formula previously proposed. METHODS: Longitudinal prospective study conducted in outpatients that underwent to LASIK. Patients underwent complete ophthalmic examination, previously and 2 months after the surgery. Intraocular pressure was evaluated with Goldmann applanation tonometer between 9 am and 11 am, average simulated keratometry was evaluated using corneal topography and central corneal thickness was measured with ultrasound pachymetry, been considered the average of three measurements. Two patients were excluded due to surgery or eye disease, and previous use of topical steroids over the past three months. The surgeries were performed according to standard procedures. The formula [real IOP = IOP measured + (540 - ECC)/71 + (43 - K)/2.7 + 0.75 mmHg] proposed for correcting intraocular pressure was used. RESULTS: Fifteen eyes of eight patients were evaluated, age ranged from 24 to 46 years (mean: 31.37 ± 7.27). There was a statistically significant difference between the measurements of intraocular pressure, central corneal thickness and average simulated keratometry pre and post-LASIK. (p=0.0001). It was observed that each 1D corrected underestimated the IOP 1.06 ± 0.59 mmHg (0.11 a 1.89 mmHg). The use of the corrective formula lead to 80% of eyes within 2.50 mmHg of preoperative intraocular pressure. Although, the two sets of data are statistically different (p=0.0266). CONCLUSIONS: Post LASIK eyes presented lower intraocular pressure than preoperatively. Intraocular pressure was moderately correlated to central corneal thickness and weakly correlated to average simulated keratometry. With the use of the corrective formula, we were able to determine that 80% were within 2.50 mmHg of the preoperative intraocular pressure.

Assuntos

Pressão Intraocular/fisiologia , Ceratomileuse Assistida por Excimer Laser In Situ , Adulto , Algoritmos , Astigmatismo/cirurgia , Córnea/patologia , Topografia da Córnea , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Miopia/cirurgia , Tamanho do Órgão , Período Pós-Operatório , Estudos Prospectivos , Tonometria Ocular , Resultado do Tratamento , Adulto Jovem

RESUMO

OBJETIVO: Comparar a pressão intraocular (PIO) pré e pós-LASIK, correlacionando-as com as mudanças da espessura corneana central (ECC) e ceratometria simulada média (K), assim como verificar o resultado de fórmula corretiva proposta anteriormente. MÉTODOS: Estudo longitudinal, prospectivo, realizado em pacientes submetidos a LASIK. Os pacientes foram submetidos ao exame oftalmológico completo, no pré operatório e após 2 meses da cirurgia. A pressão intraocular foi avaliada com tonômetro de aplanação de Goldmann entre 9 h e 11 h da manhã, a ceratometria simulada média foi avaliada por meio de topografia corneana e a espessura corneana central foi aferida por paquímetro ultrassônico, sendo considerada a média de três aferições. Foram excluídos dois pacientes com cirurgias ou doenças oculares prévias, e uso prévio de corticosteróide tópico nos últimos três meses. As cirurgias foram realizadas de acordo com os procedimentos-padrão. Foi utilizada a fórmula [PIO real = PIO aferida + (540 - ECC)/71 + (43 - K)/2,7 + 0,75 mmHg] proposta para correção da pressão intraocular pós-operatória. RESULTADOS: Quinze olhos de oito pacientes foram avaliados, a idade variou de 24 a 46 anos (média: 31,37 ± 7,27). Foi observada diferença estatisticamente significante entre as medidas da pressão intraocular, de ceratometria simulada média e da espessura corneana central pré e pós-LASIK. (p=0,0001). Foi observado que para cada 1D corrigida, há uma subestimação, em média, de 1,06 ± 0,59 mmHg (0,11 a 1,89 mmHg). A aplicação da fórmula corretiva levou a 80 por cento dos olhos com a tonometria estimada entre ± 2,50 mmHg da pré-operatória, no entanto, quando comparada com a tonometria pré-operatória, estas são estatisticamente diferentes (p=0,0266). CONCLUSÕES: Os olhos submetidos a LASIK apresentaram PIO pós-operatória menor do que a pré-operatória. A pressão intraocular pôde ser moderadamente correlacionada com a espessura corneana central e fracamente com a ceratometria simulada média. Não houve correlação entre a profundidade de ablação e a variação da pressão intraocular, no pós-operatório. Usando a fórmula proposta, pudemos averiguar que 80 por cento dos pacientes apresentaram pressão intraocular entre ± 2,50 mmHg da pré-operatória.

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PURPOSE: To compare the intraocular pressure (IOP) pre and post LASIK, correlating it to changes in central corneal thickness (CCT) and average simulated keratometry (K), as well as verifying the results of a corrective formula previously proposed. METHODS: Longitudinal prospective study conducted in outpatients that underwent to LASIK. Patients underwent complete ophthalmic examination, previously and 2 months after the surgery. Intraocular pressure was evaluated with Goldmann applanation tonometer between 9 am and 11 am, average simulated keratometry was evaluated using corneal topography and central corneal thickness was measured with ultrasound pachymetry, been considered the average of three measurements. Two patients were excluded due to surgery or eye disease, and previous use of topical steroids over the past three months. The surgeries were performed according to standard procedures. The formula [real IOP = IOP measured + (540 - ECC)/71 + (43 - K)/2.7 + 0.75 mmHg] proposed for correcting intraocular pressure was used. RESULTS: Fifteen eyes of eight patients were evaluated, age ranged from 24 to 46 years (mean: 31.37 ± 7.27). There was a statistically significant difference between the measurements of intraocular pressure, central corneal thickness and average simulated keratometry pre and post-LASIK. (p=0.0001). It was observed that each 1D corrected underestimated the IOP 1.06 ± 0.59 mmHg (0.11 a 1.89 mmHg). The use of the corrective formula lead to 80 percent of eyes within 2.50 mmHg of preoperative intraocular pressure. Although, the two sets of data are statistically different (p=0.0266). CONCLUSIONS: Post LASIK eyes presented lower intraocular pressure than preoperatively. Intraocular pressure was moderately correlated to central corneal thickness and weakly correlated to average simulated keratometry. With the use of the corrective formula, we were able to determine that 80 percent were within 2.50 mmHg of the preoperative intraocular pressure.

Assuntos

Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Pressão Intraocular/fisiologia , Ceratomileuse Assistida por Excimer Laser In Situ , Algoritmos , Astigmatismo/cirurgia , Topografia da Córnea , Córnea/patologia , Miopia/cirurgia , Tamanho do Órgão , Período Pós-Operatório , Estudos Prospectivos , Tonometria Ocular , Resultado do Tratamento

RESUMO

Fullerenols have been a subject of intense research in many fields with the claim of possible applications in biomedicine such as free-radical sponges, antioxidants, and photosensitizers. However, its transport characteristics, important in determining the feasibility of many applications, have not been studied yet. In this work, electrochemical impedance of aqueous solutions of two types of fullerenols (C(60)(OH)(22-26) and C(60)(OH)(18-22)(OK)(4)) was measured. Sample conductivity was extracted from impedance data, and a nonlinear concentration-dependent conductivity was found for one of two types (C(60)(OH)(18-22)(OK)(4)). A concentration-dependent mobility that accounts electrophoretic and relaxation effects could explain experimental data. As a result, we obtained some fullerenol parameters, relevant to transport phenomena: its hydrodynamic radius, the number of attached hydroxides, and the number of counterions solvated into solution. In addition, an important result for pharmaceutical applications has been discussed, which is the change of pH in water induced by the different concentrations of fullerenol, indicating it behaves as a weak acid.

RESUMO

Fullerenes, and in particular the C60, have been intensively investigated in the last decades mainly because of their vast range of potential applications in biomedicine and materials science. These molecules are inherently hydrophobic, tending thus to form clusters and aggregates in polar solvents resulting in colloidal suspensions. In this work was developed a quantification method for C60 nanoparticles (nano-C60) in colloidal aqueous suspensions based on optical light scattering (nephelometry). This method can be done in a conventional spectrofluorimeter either on the excitation wavelengths or on the second-order satellite lines that arise from the diffraction gratings. The detection limit of the proposed method was about (0.0090+/-0.0008) mg L(-1), in a linear concentration range from 0.007 to 0.360 mg L(-1). A comparison of this scattering technique with spectrophotometry based on molecular absorption shows that for the former, even at the second-order lines, the threshold concentrations detected are about 20 times lower that the latter.

Assuntos

Fulerenos/análise , Nanopartículas/análise , Espalhamento de Radiação , Fluorometria , Fulerenos/química , Nanopartículas/química , Suspensões , Água

RESUMO

O objetivo deste trabalho é conceituar e classificar os passivos contingentes do governo e avaliar seu gerenciamento, bem como analisar e estimar o seu surgimento e os seus impactos na Dívida Líquida do Setor Público (DLSP), tanto em passado recente (1996-2003), quanto em futuro próximo (2004-2006). Sustenta-se que, no período entre janeiro de 1996 e junho de 2003, ocorreu expressivo crescimento da dívida pública, do qual boa parte (50,8 por cento) é explicada pelo reconhecimento de passivos contingentes e pelos juros decorrentes desse ajuste patrimonial. Entretanto, a maior parte do ajuste patrimonial que pressionou a dívida líquida brasileira deveu-se a certos programas que, ao menos prima facie, contribuíram para consolidar um ajuste fiscal estrutural do setor público. No tocante aos prováveis impactos fiscais (em termos de efeitos sobre a trajetória da dívida) do reconhecimento de passivos contingentes, assumindo-se um cenário básico, há razões para acreditar que a trajetória da relação DLSP/PIB seja sustentável. De acordo com os resultados das simulações, dependendo do cenário de reconhecimento de passivos contingentes, a relação DLSP/PIB atingiria, em 2006, valores entre 53,4 por cento e 60,6 por cento. O exercício de simulação mostra também a utilidade da manutenção de superávits primários elevados (da ordem dos atuais 4,25 por cento do PIB) para criar um "colchão amortecedor" relativamente seguro contra os riscos fiscais representados pelos "esqueletos". Finalmente, além de recomendações de política econômica, este trabalho apresenta sugestões, baseadas na experiência e na literatura internacionais, sobre a gestão e o quadro institucional dos passivos contingentes par ao caso brasileiro.

Assuntos

Políticas, Planejamento e Administração em Saúde/economia , Administração Financeira , Administração Pública , Brasil

RESUMO

A descompressäo cirúrgica do túnel carpal sob anestesia local foi realizada em 16 pacientes, totalizando 26 punhos (dez bilaterais), com o objetivo de demonstrar a exeqüibilidade da operaçäo, bem como de colher impressöes dos pacientes submetidos a esse tipo de procedimento, tendo em vista que a descompressäo cirúrgica do túnel do carpo sob outros tipos de anestesia já é procedimento consagrado. A escolha dos pacientes foi aleatoria, num grupo no qual o diagnóstico fora baseado nas características clínicas da lesäo, com ênfase nos sinais de Phalen e Tinel ao nível do punho. Os resultados foram plenamente satisfatórios

Assuntos

Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Anestesia Local , Síndrome do Túnel Carpal/cirurgia , Distribuição Aleatória