RESUMO
The pathogenicity of Xylella fastidiosa is associated with its ability to colonize the xylem of host plants. Expression of genes contributing to xylem colonization are suppressed, while those necessary for insect vector acquisition are increased with increasing concentrations of diffusible signal factor (DSF), whose production is dependent on RpfF. We previously demonstrated that transgenic citrus plants ectopically expressing rpfF from a citrus strain of X. fastidiosa subsp. pauca exhibited less susceptibility to Xanthomonas citri subsp. citri, another pathogen whose virulence is modulated by DSF accumulation. Here, we demonstrate that ectopic expression of rpfF in both transgenic tobacco and sweet orange also confers a reduction in disease severity incited by X. fastidiosa and reduces its colonization of those plants. Decreased disease severity in the transgenic plants was generally associated with increased expression of genes conferring adhesiveness to the pathogen and decreased expression of genes necessary for active motility, accounting for the reduced population sizes achieved in the plants, apparently by limiting pathogen dispersal through the plant. Plant-derived DSF signal molecules in a host plant can, therefore, be exploited to interfere with more than one pathogen whose virulence is controlled by DSF signaling.
Assuntos
Proteínas de Bactérias/metabolismo , Citrus/genética , Citrus/microbiologia , Nicotiana/genética , Nicotiana/microbiologia , Doenças das Plantas/microbiologia , Xylella/metabolismo , Regulação Bacteriana da Expressão Gênica , Plantas Geneticamente Modificadas , Transformação Genética , Xylella/genéticaRESUMO
Proteasome inhibitors are emerging as a new class of chemopreventive agents and have gained huge importance as potential pharmacological tools in breast cancer treatment. Improved understanding of the role played by proteases and their specific inhibitors in humans offers novel and challenging opportunities for preventive and therapeutic intervention. In this study, we demonstrated that the Bowman-Birk protease inhibitor from Vigna unguiculata seeds, named black-eyed pea trypsin/chymotrypsin Inhibitor (BTCI), potently suppresses human breast adenocarcinoma cell viability by inhibiting the activity of proteasome 20S. BTCI induced a negative growth effect against a panel of breast cancer cells, with a concomitant cytostatic effect at the G2/M phase of the cell cycle and an increase in apoptosis, as observed by an augmented number of cells at the sub-G1 phase and annexin V-fluorescin isothiocyanate (FITC)/propidium iodide (PI) staining. In contrast, BTCI exhibited no cytotoxic effect on normal mammary epithelial cells. Moreover, the increased levels of intracellular reactive oxygen species (ROS) and changes in the mitochondrial membrane potential in cells treated with BTCI indicated mitochondrial damage as a crucial cellular event responsible for the apoptotic process. The higher activity of caspase in tumoral cells treated with BTCI in comparison with untreated cells suggests that BTCI induces apoptosis in a caspase-dependent manner. BTCI affected NF-kB target gene expression in both non invasive and invasive breast cancer cell lines, with the effect highly pronounced in the invasive cells. An increased expression of interleukin-8 (IL-8) in both cell lines was also observed. Taken together, these results suggest that BTCI promotes apoptosis through ROS-induced mitochondrial damage following proteasome inhibition. These findings highlight the pharmacological potential and benefit of BTCI in breast cancer treatment.
RESUMO
In this study, kinetic parameters were determined for the biodegradation of BTX compounds in a fixed-bed reactor with immobilized biomass, fed with mono- and multicomponent systems. The parameter estimation was achieved through an algorithm using the finite volume method. Different kinetic models were evaluated. The Monod model proved to be suitable to predict the experimental data for the biodegradation individual BTX compound. In multicomponent systems, it was found that the presence of more than one compound tends to cause competitive inhibition. To identify the models that best fit the experimental data, a statistical analysis using the F test was applied. For the two- and three-component systems the presence of more than one compound tends to cause competitive inhibition. In this study, it was possible to predict kinetic parameters in mono- and multicomponent systems as well as different operation conditions for a fixed-bed reactor with immobilized biomass.
Assuntos
Benzeno/metabolismo , Biodegradação Ambiental , Biomassa , Tolueno/metabolismo , Xilenos/metabolismo , Cinética , Modelos TeóricosRESUMO
Since the inception of its proficiency test program to evaluate radionuclide measurement in hospitals and clinics, the National Metrology Laboratory of Ionizing Radiation-LNMRI, that represents Brazilian National Metrology Institute (NMI) for ionizing radiation has expanded its measurement and calibration capability. Requirements from the National Health Surveillance Agency from Ministry of Health (ANVISA), to producers of radiopharmaceuticals provided an opportunity to improve the full traceability chain to the highest level. Fluorodeoxyglucose (FDG-(18)F) is the only radiopharmaceutical simultaneously produced by all Brazilian radiopharmaceutical production centers (RPCs). By running this proficiency test, LNMRI began to provide them with the required traceability. For evaluation, the ratio of RPC to reference value results and ISO/IEC17043:2010 criteria were used. The reference value established as calibration factor on the secondary standard ionization chamber was obtained from three absolute measurements systems, and routinely confirmed in each round of proficiency test by CIEMAT/NIST liquid scintillation counting. The γ-emitting impurities were checked using a High-Purity Germanium (HPGe) detector. The results show that Brazilian RPCs are in accordance with (accuracy within ±10%) the Brazilian standard for evaluation of measurements with radionuclide calibrators (CNEN NN 3.05., 2013). Nevertheless, the RPCs should improve the methodology of uncertainty estimates, essential when using the statistical criteria of ISO/IEC 17043 standard, in addition to improving accuracy to levels consistent with their position in the national traceability chain.
Assuntos
Radioisótopos de Flúor/análise , Radioisótopos de Flúor/normas , Setor Público/normas , Radiometria/métodos , Radiometria/normas , Brasil , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Objetivou-se com este estudo, caracterizar os aspectos epidemiológicos das intoxicações humanas, ocasionadas por plantas no Estado de Pernambuco (PE), através de uma abordagem transversal e descritiva a partir de notificações obtidas no Centro de Assistência Toxicológica deste Estado, no período de 1992 a 2009. Foram analisados 214 prontuários com base nas variáveis: sexo, faixa etária, agente tóxico vegetal, sazonalidade, zona de ocorrência, local do acidente, via de exposição, circunstância, tipo de atendimento, evolução clínica. As intoxicações predominaram no sexo feminino (52,34%), faixa etária de 1 a 4 anos (42,52%), e a maioria ocorreu nos meses de fevereiro, agosto e outubro. A maioria das intoxicações foi na área urbana (74,30%), em acidentes nas residências (72,90%), através de plantas, sendo que 85% por via oral. A família Araceae foi responsável por 35,98% das intoxicações, seguida das famílias Euphorbiaceae 23,83% e Solanaceae com 5,60% dos casos. Os pacientes foram atendidos e a gravidade dos casos, em sua maioria, evoluiu para melhora de saúde, não sendo possível fazer o registro de cura, pelo fato de os mesmos deixarem o hospital sem a devida alta. Espera-se alertar os profissionais de saúde da importância das plantas, como fator de risco de intoxicação, possibilitando o estabelecimento de políticas públicas de prevenção e promoção da saúde.(AU)
The objective of this study was to characterize the epidemiological aspects of human poisoning caused by plants in the State of Pernambuco. This is a cross-sectional descriptive study from notifications obtained in the Toxicological Assistance Centre of Pernambuco (CEATOX), between 1992-2009. 214 records were analyzed using these variables: sex, age group, vegetal toxic agent, seasonality, occurrence zone locations, poisoning site, way of contamination, circumstances of poisoning, type of treatment, and the outcome. Poisoning predominated in females (52.34%) aged 1 to 4 years (42.52%) and the majority occurred in February, August and October. Most poisonings took place in the urban zone (74.30%), caused by home accidents (72.90%) by the oral ingestion of the toxic agent (85%). The family Araceae accounted for (35.98%) of poisonings, followed by Euphorbiaceae families (23.83%) and Solanaceae with (5.60%). Patients were treated and mostly evolved into health improvement, but we lack data regarding cure due to the fact that the patients left the hospital without proper medical release. We hope to alert health professionals of the importance of poisonous plants as a risk factor, enabling the establishment of new public policies for health promotion and prevention for the general public.(AU)
Assuntos
Humanos , Intoxicação por Plantas/epidemiologia , Distribuição por Idade , Brasil/epidemiologia , Estudos Transversais , Fitoterapia/efeitos adversos , Centros de Controle de IntoxicaçõesRESUMO
RESUMO Este trabalho teve por objetivo avaliar o efeito bactericida in vitro de dezesseis óleos essenciais sobre Escherichia coli enterotoxigênica (ETEC). Dentre os óleos essenciais estudados, três foram extraídos in situ por arraste a vapor e treze foram adquiridos comercialmente. Todos os óleos foram analisados por CG-EM e CG-DIC. A atividade bactericida foi avaliada pelo método de microdiluição utilizando-se caldo triptona de soja e microplacas de poliestireno de 96 poços, com posterior plaqueamento das culturas em ágar triptona de soja. Os óleos essenciais de Cinnamomum cassia e de Thymus vulgaris apresentaram concentração mínima bactericida (CMB) de 0,12% e 0,25%, respectivamente. Já os óleos comerciais de Syzygium aromaticum e Origanum vulgare apresentaram ambos CMB de 0,50% e os óleos extraídos in situ de Cymbopogon citratus e Origanum vulgare apresentaram ambos CMB de 1,00%. Os dezesseis óleos essenciais apresentaram composição química qualitativa e quantitativa distintas. As análises químicas dos óleos essenciais de Cinnamomum cassia e de Thymus vulgaris tiveram a presença majoritária de E-cinamaldeído (84,52%) e timol (50,89%). Conclui-se que os óleos de C. cassia e T. vulgaris foram os mais eficazes na inibição do crescimento in vitro dessa bactéria, a qual possui diferentes níveis de sensibilidade dependendo da composição química do óleo.
ABSTRACT This study aimed to evaluate the bactericidal effect in vitro of sixteen essential oils on enterotoxigenic Escherichia coli (ETEC). Among the essential oils, three were extracted in situ by steam distillation and thirteen were purchased commercially. All oils were analyzed by GC-MS and GC-FID. The bactericidal activity was evaluated by the microdilution method using tryptone soy broth, and 96-well polystyrene microplates with subsequent plating of the cultures in tryptone soy agar. Cinnamomum cassia and Thymus vulgaris essential oils showed minimal bactericidal concentration (MBC) 0.12% and 0.25%, respectively. Both commercial oils of Syzygium aromaticum and Origanum vulgare showed MBC of 0.50% and the oils extracted in situ Origanum vulgare and Cymbopogon citratus showed both MBC of 1.00%. The sixteen essential oils pointed out distinct qualitative and quantitative chemical composition. Chemical analysis of Cinnamomum cassia and Thymus vulgaris oils had the predominant presence of E-cinnamaldehyde (84.52% ± 0.07%) and thymol (50.89% ± 0.31%). In conclusion, T. vulgaris and C. cassia oils were the most effective in inhibiting in vitro growth of this bacterium, which has different sensitivity levels depending on the chemical composition of the oil.
Assuntos
Óleos Voláteis/análise , Química , Escherichia coli Enterotoxigênica/classificação , Cromatografia Gasosa/métodos , Cinnamomum zeylanicum , Thymus (Planta)/classificaçãoRESUMO
Biodesulfurization is an eco-friendly technology applied in the removal of sulfur from fossil fuels. This technology is based on the use of microorganisms as biocatalysts to convert the recalcitrant sulfur compounds into others easily treatable, as sulfides. Despite it has been studied during the last decades, there are some unsolved questions, as per example the kinetic model which appropriately describes the biodesulfurization globally. In this work, different kinetic models were tested to a batch desulfurization process using dibenzothiophene (DBT) as a model compound, n-dodecane as organic solvent, and Rhodococcus erythropolis ATCC 4277 as biocatalyst. The models were solved by ODE45 function in the MATLAB. Monod model was capable to describe the biodesulfurization process predicting all experimental data with a very good fitting. The coefficients of determination achieved to organic phase concentrations of 20, 80, and 100 % (v/v) were 0.988, 0.995, and 0.990, respectively. R. erythropolis ATCC 4277 presented a good affinity with the substrate (DBT) since the coefficients of saturation obtained to reaction medium containing 20, 80, and 100 % (v/v) were 0.034, 0.07, and 0.116, respectively. This kinetic evaluation provides an improvement in the development of biodesulfurization technology because it showed that a simple model is capable to describe the throughout process.
Assuntos
Combustíveis Fósseis/microbiologia , Modelos Biológicos , Rhodococcus/metabolismo , Enxofre/metabolismo , Cinética , Solventes/química , Tiofenos/metabolismoRESUMO
Some of the noxious atmospheric pollutants such as nitrogen and sulfur dioxides come from the fossil fuel combustion. Biodesulfurization and biodenitrogenation are processes which remove those pollutants through the action of microorganisms. The ability of sulfur and nitrogen removal by the strain Rhodococcus erythropolis ATCC 4277 was tested in a biphasic system containing different heavy gas oil concentrations in a batch reactor. Heavy gas oil is an important fraction of petroleum, because after passing through, the vacuum distillation is incorporated into diesel oil. This strain was able to remove about 40% of the nitrogen and sulfur present in the gas heavy oil. Additionally, no growth inhibition occurred even when in the presence of pure heavy gas oil. Results present in this work are considered relevant for the development of biocatalytic processes for nitrogen and sulfur removal toward building feasible industrial applications.
Assuntos
Gases/metabolismo , Dióxido de Nitrogênio/metabolismo , Petróleo , Rhodococcus/crescimento & desenvolvimento , Dióxido de Enxofre/metabolismoRESUMO
Este trabalho objetivou identificar a importância de plantas medicinais como primeira linha de ação para enfermidades em população residente no território da Estratégia Saúde da Família (ESF) de Montes Claros/MG, Brasil. A pesquisa foi transversal e descritiva, realizada em 2010, sendo a coleta de dados obtida por questionário semi-estruturado. O cálculo amostral do cenário do estudo embasou-se no número de famílias da ESF. O tratamento estatístico considerou o nível de significância p<0,05. Para cada família (N=253) foi entrevistada uma pessoa. Dos entrevistados, 75,5 % utilizam plantas medicinais; sem associação com renda, cor de pele, escolaridade e sexo (p>0,05). Quase a metade dos entrevistados (45,1 %) informou que utiliza mais de uma planta por vez. No caso de doença, após consulta e prescrição médica, uma parcela importante dos usuários de plantas (48,7 %) usa apenas o medicamento alopático. Concluiu-se que a utilização de plantas medicinais como recurso terapêutico independe de escolaridade e renda familiar, sugerindo incorporação cultural da prática integrativa na comunidade nortemineira estudada.
This study aimed to identify the importance of medicinal plants as a first line of action when treating diseases in populations residing in the territory of the Family Health Strategy (FHS) in Montes Claros,/state of Minas Gerais, Brazil.tThis is a cross-sectional descriptive research. Data collection took place by means of a semi-structured questionnaire in 2010. The sample size calculation was based on the number of families in the FHS study setting. For statistical analysis, the significance level considered was p <0.05. One personofrom each family (253) was interviewed. Of the respondents, regardless of income, skin color, education and sex, 75.5 % stated they use medicinal plants (p> 0.05). Almost half of respondents (45.1 %) reported the use of more than one plant at a time. In the event of illness, 42.3 % reported to use medicinal plants and visit the doctor. In case of illness, after consultation and prescription, a significant portion of the plant users (48.7 %) uses only allopathic medicine.sWe concluded that the use of medicinal plants as a therapeutic resource is independent of education and income, which suggestg cultural incorporation of the integrative practice in the community studied.
Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Características de Residência , /estatística & dados numéricos , Plantas Medicinais/efeitos adversos , Terapêutica , FitoterapiaRESUMO
Electrocardiographic effects produced by Ginkgo biloba extract (EGb) and by ginkgolides A (GA) and B (GB), and bilobalide (BB) were investigated in guinea pig heart mounted in Langendorff apparatus (Tyrode, 34 ± 0.1 ºC, 95% O2, 5% CO2). Electrocardiographic parameters were evaluated in the conditions: 1) control with Tyrode and DMSO, 2) EGb (n=4), GA (n=5), GB (n=5) or BB (n=6), and 3) washout. The results showed that 0.1 and 1.0 mg/ml of EGb do not change the electrocardiographic parameters. However, 10 mg/ml of EGb increased the PR interval (PRi) at 21% (p<0.001). This increase was also observed for 50 mM GA (20%, p<0.001) and 70 mM BB (13%, p<0.001), which indicates Ca2+ channel block. However, the 50 mM GB reduced the PRi at 11 % (p<0.001). The GA (23%, p<0.001), GB (16%, p<0.001), and BB (40%, p<0.001) reduced the QT interval (QTi), which suggests the activation of the potassium channel. However, EGb increased QTi (6%, p<0.001). The EGb (28%, p<0.05) and GB (13%, p<0.05) reduced the heart rate. Atrioventricular (AV) block was observed with EGb, GA, and BB. We can conclude that EGb and its terpenoids alter the ECG parameters inducing AV block, which indicates possible arrhythmogenic potential.
Os efeitos eletrocardiográficos produzidos pelo extrato de Ginkgo biloba (EGb) e gingkolídeos A (GA) e B (GB), e bilobalide (BB) foram investigados em coração de cobaia montado sistema de Langendorff (Tyrode, 34 ± 0.1 ºC, 95% O2, 5% CO2). Os parâmetros do ECG foram avaliados nas condições: 1) Tyrode e DMSO, 2) EGb (n=4), GA (n=5), GB (n=5) ou BB (n=6) diluídos em DMSO e 3) washout. Os resultados demonstram que 0,1 e 1,0 mg/mL de EGb não alteraram os parâmetros eletrocardiográficos. Entretanto, 10 mg/ml de EGb aumentaram o intervalo PR (PRi) em 21% (p<0.001). Esse aumento também foi observado com GA a 50µM (20%, p<0,001) e BB a 70 mM (13%, p<0,001) indicando bloqueio de canais de cálcio. Por outro lado, GB reduziu o PRi (11%, p<0,001). O intervalo QT (QTi) foi reduzido por GA (23%, p<0,001), GB (16%, p<0,001) e BB (40%, p < 0.001) sugerindo uma ativação de canais de potássio. Entretanto, EGb aumentou o QTi (6%, p<0.001). A frequência cardíaca foi reduzida por EGb (28%, p<0.05) e GB (13%, p<0.05). Bloqueios átrio-ventriculares (BAV) foram observados com EGb, GA e BB. Podemos concluir que EGb e os terpenos alteram parâmetros eletrocardiográficos induzindo BAV e demonstrando possível potencial arritmogênico.
Assuntos
Cobaias , Terpenos/análise , Extratos Vegetais/antagonistas & inibidores , Ginkgo biloba/efeitos adversos , Eletrocardiografia , Ginkgolídeos/análise , Bilobalídeos/farmacologia , Coração/efeitos dos fármacosRESUMO
Cellulase is one of the enzymes most commonly used in the textile industry for the biopolishing process. The appropriate choice of pretreatment is a possible route to promoting enzymatic attack in situations in which this is not favored due to the effects of packing. In order to evaluate the influence of pretreatment the yarn was maintained in water for 24h before biopolishing to promote greater spacing between the chains. In the tensile testing the pretreated Combed 13/1 yarn showed a greater percentage reduction in the maximum breaking force following biopolishing, evidencing a stronger enzymatic attack. Also, the Combed 13/1 and OE 14/1 yarns without pretreatment had an approximately 22% reduction in the shrinkage and after pretreatment the Carded 13/1 yarn had the best shrinkage reduction values (18%). These data demonstrate that the introduction of the pretreatment promotes a change in the access of the enzyme to the fiber.
Assuntos
Celulase/química , Celulose/química , Gossypium/química , Óleos Industriais , Resistência à Tração , Fibra de Algodão/métodos , Ensaios Enzimáticos , Teste de Materiais/métodos , Microfibrilas/química , Estresse Mecânico , Água/químicaRESUMO
Xylella fastidiosa is a xylem-limited, Gram-negative phytopathogen responsible for economically relevant crop diseases. Its genome was thus sequenced in an effort to characterize and understand its metabolism and pathogenic mechanisms. However, the assignment of the proper functions to the identified open reading frames (ORFs) of this pathogen was impaired due to a lack of sequence similarity in the databases. In the present work, we used small-angle X-ray scattering and in silico modeling approaches to characterize and assign a function to a predicted LysR-type transcriptional regulator in the X. fastidiosa (XfLysRL) genome. XfLysRL was predicted to be a homologue of BenM, which is a transcriptional regulator involved in the degradation pathway of aromatic compounds. Further functional assays confirmed the structural prediction because we observed that XfLysRL interacts with benzoate and cis,cis-muconic acid (also known as 2E,4E-hexa-2,4-dienedioic acid; hereafter named muconate), both of which are co-factors of BenM. In addition, we showed that the XfLysRL protein is differentially expressed during the different stages of X. fastidiosa biofilm formation and planktonic cell growth, which indicates that its expression responds to a cellular signal that is likely related to the aromatic compound degradation pathway. The assignment of the proper function to a protein is a key step toward understanding the cellular metabolic pathways and pathogenic mechanisms. In the context of X. fastidiosa, the characterization of the predicted ORFs may lead to a better understanding of the cellular pathways that are linked to its bacterial pathogenicity.
Assuntos
Proteínas de Bactérias/química , Modelos Moleculares , Espalhamento a Baixo Ângulo , Difração de Raios X/métodos , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Benzoatos/química , Benzoatos/metabolismo , Benzoatos/farmacologia , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Simulação por Computador , Eletroforese em Gel de Poliacrilamida , Dados de Sequência Molecular , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Ácido Sórbico/análogos & derivados , Ácido Sórbico/química , Ácido Sórbico/metabolismo , Ácido Sórbico/farmacologia , Xylella/genética , Xylella/metabolismo , Xylella/fisiologiaRESUMO
Establishing criteria for hospital nutrition care ensures that quality care is delivered to patients. The responsibility of the Hospital Food and Nutrition Service (HFNS) is not always well defined, despite efforts to establish guidelines for patient clinical nutrition practice. This study describes the elaboration of an Instrument for Evaluation of Food and Nutritional Care (IEFNC) aimed at directing the actions of the Hospital Food and Nutrition Service. This instrument was qualified by means of a comparative analysis of the categories related to hospital food and nutritional care, published in the literature. Elaboration of the IEFNC comprised the following stages: (a) a survey of databases and documents for selection of the categories to be used in nutrition care evaluation, (b) a study of the institutional procedures for nutrition practice at two Brazilian hospitals, in order to provide a description of the sequence of actions that should be taken by the HFNS as well as other services participating in nutrition care, (c) design of the IEFNC based on the categories published in the literature, adapted to the sequence of actions observed in the routines of the hospitals under study, (d) application of the questionnaire at two different hospitals that was mentioned in the item (b), in order to assess the time spent on its application, the difficulties in phrasing the questions, and the coverage of the instrument, and (e) finalization of the instrument. The IEFNC consists of 50 open and closed questions on two areas of food and nutritional care in hospital: inpatient nutritional care and food service quality. It deals with the characterization and structure of hospitals and their HFNS, the actions concerning the patients' nutritional evaluation and monitoring, the meal production system, and the hospital diets. "This questionnaire is a tool that can be seen as a portrait of the structure and characteristics of the HFNS and its performance in clinical and meal management dietitian activities."
Assuntos
Serviço Hospitalar de Nutrição/normas , Alimentos/normas , Terapia Nutricional/normas , Inquéritos e Questionários , Brasil , Bases de Dados Factuais , Alimentos/estatística & dados numéricos , Serviço Hospitalar de Nutrição/estatística & dados numéricos , Pesquisas sobre Atenção à Saúde , Humanos , Terapia Nutricional/estatística & dados numéricosRESUMO
The decline in stocks of commercial fish species has been documented in several regions of the world. This decline is due partially to the effect of evolutionary pressure caused by the management of fishing activity, which reduces the size of fish after a few generations. In this paper, the population dynamics of the Pintado Pseudoplatystoma corruscans, one of the main commercial species of freshwater fish in Brazil, were simulated considering different scenarios of fishing mortality and different minimum and maximum lengths of capture. The results show that selective fishing based on the different proposed selectivity curves can result in an evolution-mediated increase in the growth rate of the fish, the biomass and the catch. This suggests that appropriate changes in Brazilian legislation can contribute to the sustainability of fisheries and to conservation of the fish stocks exploited by man.
Assuntos
Peixes-Gato , Conservação dos Recursos Naturais/métodos , Animais , Evolução Biológica , Biomassa , Brasil , Peixes-Gato/genética , Simulação por Computador , Conservação dos Recursos Naturais/estatística & dados numéricos , Pesqueiros , Humanos , Modelos Logísticos , Dinâmica Populacional/estatística & dados numéricosRESUMO
In this study, the cytotoxicity, genotoxicity and early ROS generation of 2,2-dimethyl-(3H)-3-(N-3'-nitrophenylamino)naphtho[1,2-b]furan-4,5-dione (QPhNO(2)) were investigated and compared with those of its precursor, nor-beta-lapachone (nor-beta), with the main goal of proposing a mechanism of antitumor action. The results were correlated with those obtained from electrochemical experiments held in protic (acetate buffer pH 4.5) and aprotic (DMF/TBABF(4)) media in the presence and absence of oxygen and with those from dsDNA biosensors and ssDNA in solution, which provided evidence of a positive interaction with DNA in the case of QPhNO(2). QPhNO(2) caused DNA fragmentation and mitochondrial depolarization and induced apoptosis/necrosis in HL-60 cells. Pre-treatment with N-acetyl-l-cysteine partially abolished the observed effects related to the QPhNO(2) treatment, including those involving apoptosis induction, indicating a partially redox-dependent mechanism. These findings point to the potential use of the combination of pharmacology and electrochemistry in medicinal chemistry.
Assuntos
Antineoplásicos/farmacologia , Benzofuranos/farmacologia , Naftoquinonas/farmacologia , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Dano ao DNA , Células HL-60 , Humanos , Oxirredução , Espécies Reativas de Oxigênio/metabolismoRESUMO
A prevalência da obesidade está aumentando a um ritmo alarmante e poucos medicamentos para o tratamento estão atualmente disponíveis no mercado. A inibição da lipase pancreática é um dos mecanismos mais amplamente estudados para determinar a eficácia de produtos naturais como agentes antiobesidade. O objetivo do estudo foi avaliar in vitro a inibição de dezenove extratos aquosos e metanólicos sobre a lipase pancreática. Ensaios cinéticos foram realizados em quatro períodos de tempo com ausência e presença do extrato inibidor. Também foi avaliado a ação desses extratos após a simulação do fluido gástrico. Cymbopogon citratus apresentou a maior inibição, seguido de Costus spicatus e Baccharis trimera. Os extratos apresentam um potencial como adjuvante no tratamento da obesidade.
The prevalence of obesity has been increasing at an alarming rate and only a few medications are currently available in the market. Pancreatic lipase inhibition is one of the most widely studied mechanisms for determining the efficacy of natural products as anti-obesity agents. The aim of this study was to evaluate in vitro the inhibition of nineteen aqueous and methanol extracts on pancreatic lipase. Kinetic assays were performed in four periods with the absence and the presence of the inhibitor extract. We also tested the action of these extracts after gastric fluid simulation. Cymbopogon citratus showed the highest inhibition, followed by Costus spicatus and Baccharis trimera. The extracts have the potential to act as adjuvants in the treatment of obesity.
Assuntos
Extratos Vegetais/análise , Fármacos Antiobesidade/análise , Lipídeos , Obesidade/tratamento farmacológicoRESUMO
The process of bone resorption can reduce the volume of the alveolar crest, which makes may make difficult impression taking of the alveolar tissue and the subsequent fit of a new denture. This clinical report describes a fast and simple technique for impressions of edentulous ridges to replace complete dentures, using a temporary tissue conditioner material on the denture base. The existing denture must cover the whole supporting area and should be in harmony with the adjacent oral structures. This technique reduces the number of steps involved and minimizes treatment time and expenses.
Assuntos
Perda do Osso Alveolar/patologia , Técnica de Moldagem Odontológica , Planejamento de Dentadura , Arcada Edêntula/patologia , Deglutição/fisiologia , Materiais para Moldagem Odontológica/química , Bases de Dentadura , Reembasadores de Dentadura , Humanos , Mastigação/fisiologia , Fala/fisiologia , Condicionamento de Tecido Mole OralRESUMO
Radyosinovectomy (RSV) is a radiotherapeutic modality where a beta-emitting radionuclide is administered locally by intra-articular injection on the form of a colloid or radiolabeled particulate. RSV is a well-accepted therapeutic procedure in inflammatory joint diseases and has been successfully employed for more than 50 years as a viable alternative to surgical and chemical synovectomy. The aim of this work is to compare the in vivo stability of hydroxyapatite labelled with (177)Lu, (90)Y and (153)Sm. All radionuclides were labelled with high yield and were retained in the joint for 7 days, showing stability and usefulness as tools in the RSV treatment. A similar retention of the products in the muscle was observed when the particles were administrated in the muscle. However, the pure form of the radionuclides were rapidly cleared from the blood and accumulated in the liver when injected i.v.. Although (153)Sm-HA is already available for nuclear medicine procedures and clinical studies with (90)Y-HA have been developed, (177)Lu-labeled RSV agents will be economically more viable and has not been studied yet. Its favorable characteristics contribute to follow, to predict and asses the success of RSV by bone scintigraphy studies.
Assuntos
Durapatita/química , Injeções Intra-Articulares/métodos , Animais , Partículas beta , Coloides/química , Raios gama , Membro Posterior/diagnóstico por imagem , Inflamação , Lutécio/química , Tamanho da Partícula , Radioisótopos/química , Cintilografia , Ratos , Ratos Wistar , Samário/química , Distribuição Tecidual , Imagem Corporal Total , Radioisótopos de Ítrio/químicaRESUMO
Com o avanço da tecnologia e das pesquisas envolvendo liberação de fármacos, modernização de testes e maior ênfase da previsibilidade de efeitos terapêuticos por meio dos testes in vitro, os testes de dissolução e os estudos de perfis de dissolução têm ganhado cada vez mais importância. Apesar de terem sido introduzidos inicialmente como uma forma de caracterizar o perfil de liberação de fármacos pouco solúveis, atualmente os testes de dissolução fazem parte das monografias de quase todas as formas farmacêuticas sólidas orais. Este trabalho teve como objetivo estudar o perfil de dissolução (porcentagem de fármaco dissolvido versus tempo) dos medicamentos de referência, genérico e similar contendo cefalexina 500 mg na forma farmacêutica de cápsulas. Foram analisadas três especialidades farmacêuticas (referência, genérico e similar), os quais foram submetidos ao teste de dissolução e perfil de dissolução in vitro. Os resultados obtidos no teste de dissolução permitem concluir que as amostras encontraram-se de acordo com as especificações e o perfil de dissolução deste medicamento, nesta forma farmacêutica, é considerado de dissolução rápida (85% de fármaco dissolvido em 15 minutos). Portanto, existe uma grande semelhança entre as curvas obtidas, o que sugere que se trata de equivalentes farmacêuticos.
With recent advances in technology and research into drug delivery, the modernization of tests and greater emphasis on the predictability of therapeutic effect by means of in vitro tests, the dissolution test and the study of dissolution profiles are gaining more and more importance. Though introduced initially as a way of characterizing the release profile of poorly soluble drugs, dissolution tests are currently part of pharmacopoeial monographs on almost all the oral solid pharmaceutical forms. The objective of this study was to determine the dissolution profile (percent drug dissolved versus time) of the pioneer brand, generic and similar pharmaceutical capsules containing 500mg cephalexin. Three pharmaceutical brands (reference, generic and similar) were subjected to the dissolution test and in vitro dissolution profiles were recorded. From the results of the dissolution test, it was concluded that the samples met the acceptance criterion, as no difference was observed in the percentage of the drug dissolved in a standard time. The dissolution profile indicated that this medicine, in this pharmaceutical form, dissolves readily (85% of the drug dissolved in 15 minutes) and the curves showed great similarity, suggesting that the 3 brands are pharmaceutically equivalent.
Assuntos
Humanos , Cápsulas , Cefalexina/farmacocinética , Medicamentos Genéricos , Medicamentos de Referência , Medicamentos SimilaresRESUMO
This article describes the microstructure and dynamics in the solid state of polyfluorene-based polymers, poly(9,9-dioctylfluorenyl-2,7-diyl) (PFO), a semicrystalline polymer, and poly[(9,9-dioctyl-2,7-divinylene-fluorenylene)-alt-co-{2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylene vinylene}, a copolymer with mesomorphic phase properties. These structures were determined by wide-angle X-ray scattering (WAXS) measurements. Assuming a packing model for the copolymer structure, where the planes of the phenyl rings are stacked and separated by an average distance of approximately 4.5 A and laterally spaced by about approximately 16 A, we followed the evolution of these distances as a function of temperature using WAXS and associated the changes observed to the polymer relaxation processes identified by dynamical mechanical thermal analysis. Specific molecular motions were studied by solid-state nuclear magnetic resonance. The onset of the side-chain motion at about 213 K (beta-relaxation) produced a small increase in the lateral spacing and in the stacking distance of the phenyl rings in the aggregated structures. Besides, at about 383 K (alpha-relaxation) there occurs a significant increase in the amplitude of the torsion motion in the backbone, producing a greater increase in the stacking distance of the phenyl rings. Similar results were observed in the semicrystalline phase of PFO, but in this case the presence of the crystalline structure affects considerably the overall dynamics, which tends to be more hindered. Put together, our data explain many features of the temperature dependence of the photoluminescence of these two polymers.