45 research outputs found

    Genotypic identification of Cryptosporidium spp. isolated from hiv-infected patients and immunocompetent children of São Paulo, Brazil

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    Cryptosporidium isolates identified in fourteen stool samples, collected from five HIV-infected patients and nine immunocompetent children, living in the Sate of São Paulo, Brazil, were submitted to a molecular analysis using a nested PCR followed of restriction fragment length polymorphism (RFLP), for genetic characterization. The analysis was based on digestion with RsaI restriction enzyme of a DNA fragment amplified from the Cryptosporidium oocyst wall protein (COWP) gene. Based on this analysis, four samples were identified as Cryptosporidium parvum, eight as Cryptosporidium hominis and two presented a profile that correspondedto Cryptosporidium meleagridis when compared to the standards used in the analysis. The use of molecular methods can be helpful to identify source of infections and risk factors related to Cryptosporidium infection in our communities.Isolados de Cryptosporidium identificados em quatorze amostras de fezes, coletadas de cinco pacientes com infecção por HIV e de nove crianças imunocompetentes, residentes no estado de São Paulo, Brasil, foram submetidos a análise molecular por Nested-PCR, seguido da caracterização genética por polimorfismo do tamanho do fragmento de restrição (RFLP). A análise foi baseada na digestão, com a enzima de restrição RsaI, de um fragmento de DNA amplificado do gene que codifica a proteína de parede do oocisto de Cryptosporidium (COWP). Baseado nesta análise, quando comparadas aos padrões utilizados, quatro amostras foram identificadas como Cryptosporidium parvum, oito como Cryptosporidium hominis e duas apresentaram um perfil correspondente ao de Cryptosporidium meleagridis. O uso de métodos moleculares pode ser útil para identificar a fonte das infecções e os fatores de risco relacionados à infecção por Cryptosporidium em nossas comunidades

    Effects of consequences on patterns of interlocked contingencies; A replication of a metacontingency experiment

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    Metacontingencies concept was taught to undergraduate students of Psychology by using a “game” simulation proposed originally by Vichi, Andery and Glenn (2009). Twenty-five students, distributed into three groups were exposed to six experimental sessions in which they had to make bets and divide the amounts gained. The three groups competed against each other for photocopies quotas. Two contingencies shifted over the sessions. Under Contingency B, the group would win points only if in the previous round each member had received the same amount of points and under Contingency A, winning was contingent on an unequal distribution of the points. We observed that proportional divisions predominated independent of the contingency in course. The manipulation of cultural consequences (winning or losing points) produced consistent modifications in two response categories: 1) choices of the value bet in each round, and 2) divisions of the points among group members. Controlling relations between cultural consequences and the behavior of dividing were statistically significant in one of the groups, whereas in the other two groups controlling relations were observed only in Contingency B. A review of the reinforcement criteria used in the original experiment is suggested

    Antibacterial evaluation of Styrax pohlii and isolated compounds

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    The antibacterial activity of the compounds egonol (1) and homoegonol (2), of the crude ethanolic extract of Styrax pohlii (Styracaceae) aerial parts (EE), and of its n-hexane (HF), EtOAc (EF), n-BuOH (BF), and hydromethanolic (HMF) fractions was evaluated against the following microorganisms: Streptococcus pneumoniae (ATCC 6305), S. pyogenes (ATCC 19615), Haemophilus influenzae (ATCC 10211), Pseudomonas aeruginosa (ATCC 27853), and Klebsiella pneumoniae (ATCC 10031). The broth microdilution method was used for determination of the minimum inhibitory concentration (MIC) during preliminary evaluation of antibacterial activity. The EE yielded MIC values of 400 µg/mL for S. pneumoniae and P. aeruginosa and 300 µg/mL for H. influenzae. The HF and EF fractions exhibited enhanced antibacterial activity, with MIC values of 200 µg/mL against S. pneumoniae, but only EF displayed activity against H. influenzae (MIC 200 µg/mL). The best MIC value with compounds 1 and 2 (400 µg/mL) was obtained for (1) against S. pneumoniae and P. aeruginosa. Therefore, 1 exhibited weak antibacterial activity against these standard strains.As atividades antimicrobianas das substâncias egonol (1) e homoegonol (2), do extrato etanólico das partes aéreas de Styrax pohlii (Styracaceae) (EE), bem como das frações n-hexano (HF), AcOEt (EF), n-BuOH (BF) e hidrometanólica (HMF) foram avaliadas frente aos seguintes microorganismos: Streptococcus pneumoniae (ATCC 6305), S. pyogenes (ATCC 19615), Haemophilus influenzae (ATCC 10211), Pseudomonas aeruginosa (ATCC 27853) e Klebsiella pneumoniae (ATCC 10031). O método de microdiluição em caldo foi utilizado para a determinação da concentração inibitória mínima (CIM) na avaliação preliminar da atividade antimicrobiana. EE mostrou valores de CIM de 400 µg/mL para S. pneumoniae e P. aeruginosa, e 300 µg/mL para H. influenzae. As frações HF e EF apresentaram melhora na atividade antimicrobiana, com valores de CIM de 200 µg/mL frente S. pneumoniae, mas apenas EF apresentou ação contra H. influenzae (200 µg/mL). Em relação às substâncias 1 e 2, o melhor valor de CIM (400 µg/mL) foi obtido por 1 frente a S. pneumoniae e P. aeruginosa, que exibiu fraca atividade antimicrobiana contra estas cepas padrões

    Evaluation of the in vitro trypanocidal activity of triterpenes uvaol, betulinic acid and its semi-synthetic derivatives against the Y strain of Trypanosoma cruzi / Avaliação da atividade tripanocida in vitro dos triterpenos uvaol, ácido betulínico e seus derivados semissintéticos contra a cepa Y de Trypanosoma cruzi

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    Chagas disease is a neglected tropical disease that affects millions of people worldwide. Trypanosoma cruzi (T. cruzi) is the causative agent of Chagas disease and its transmission occurs through blood meal by triatomine bugs, being oral transmission the most common form. More than 100 years after the disease´s discovery, benzonidazole is the only efficient drug against T. cruzi; however, this drug has numerous serious side effects and is only efficient in the acute phase of the disease. Natural products, such as triterpenes, have been an important source of new substances to combat human parasitology. In this study, two triterpenes, uvaol and betulinic acid, were tested against the parasite T. cruzi. The best results of in vitro tests were observed for uvaol with an IC50 value of 70.3 µM against the trypomastigost forms and an IC50 value of 90.6 µM against the amastigost forms. Three semi-synthetic derivatives of betulinic acid were obtained; the acetylated derivative showed excellent results against trypomastigotes forms (IC50 = 15.67 µM), but was not active against the amastigotes forms. The cytotoxic MTT test was also performed on LLCMK2 cells (Macaca mullata kidney epithelial cells) and betulinic acid showed the highest selectivity index (SI) with a value of 1.3

    Avaliação do extrato de Physalis angulata sobre larvas do carrapato Rhipicephalus (Boophilus) Microplus

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    The tick Rhipicephalus (Boophilus) microplus is responsible for large losses in livestock worldwide, causing a drop in meat and milk production, leather depreciation, annoyance to animals and transmission of hemoparasitosis that can lead to death. The control of this ectoparasite is currently carried out by synthetic chemical compounds, however, most with reported cases of resistance, makes it necessary to study new natural alternatives necessary. The present study aimed to evaluate the Physalis angulata extract between concentrations 100 - 12.5 mg mL-1 on R. (B.) microplus larvae by the impregnated paper patch test (IPPT). The results were promising and the concentrations of 100 and 50 mg mL-1 were the most effective, presenting 92.24% and 58.47% of larval mortality, respectively.La garrapata Rhipicephalus (Boophilus) microplus es responsable de grandes pérdidas en el ganado a nivel mundial, provocando caída en la producción de carne y leche, depreciación del cuero, molestias a los animales y transmisión de hemoparasitosis que puede llegar a causar la muerte. El control de este ectoparásito actualmente se realiza mediante compuestos químicos de síntesis, sin embargo, la mayoría con casos reportados de resistencia, hace necesario el estudio de nuevas alternativas naturales. El presente estudio tuvo como objetivo evaluar el extracto de Physalis angulata entre concentraciones de 100 - 12,5 mg mL-1 sobre larvas de R. (B.) microplus mediante la prueba del parche de papel impregnado (TCPI). Los resultados fueron promisorios y las concentraciones de 100 y 50 mg mL-1 fueron las más efectivas, presentando 92,24% y 58,47% de mortalidad larvaria, respectivamente.O carrapato Rhipicephalus (Boophilus) microplus é responsável por grandes perdas na pecuária mundial, causando queda na produção de carne e leite, depreciação do couro, incômodo aos animais e transmissão de hemoparasitoses que podem levar os animais a óbito. O controle desse ectoparasita atualmente é realizado por compostos químicos sintéticos, porém, a maioria com casos de resistência relatados, torna necessário o estudo de novas alternativas naturais necessárias. O presente trabalho teve como objetivo avaliar o extrato de Physalis angulata entre as concentrações 100 - 12,5 mg mL-1 sobre larvas de R. (B.) microplus pelo teste de contato em papel impregnado (TCPI). Os resultados se mostraram promissores sendo as concentrações 100 e 50 mg mL-1 as mais efetivas apresentando 92,24% e 58,47% de mortalidade das larvas respectivamente

    Antimicrobial activity of triterpene acids against phytopathogens / Atividade antimicrobiana de triterpenos ácidos contra fitopatógenos

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    Phytopathogenic microorganisms, responsible for causing diseases in various types of plantations, have an immense impact on crops, reducing food production, which is one of the main problems of agriculture. Antibiotics in association with cupric fungicides have been commonly used to solve this problem, but result in toxic residues to humans, animals and the environment, in addition to not being as effective as expected. Natural products, such as triterpenes, have become an important source of new substances to fight pathogens. In this study, the triterpenes ursolic acid, oleanolic acid and gypsogenic acid were re-isolated from Miconia stenostachya. The identification of all substances was carried out based on data obtained from 1H NMR, 13C-NMR and/or comparison with authentic standards. In the assays of antimicrobial activity against nine phytopathogenic bacteria, the triterpene gypsogenic acid was the most effective with a MIC value of 3.12; 25 and 100 µg/mL, for bacteria Ralstonia solanacearum, Pseudomonas syringae and Streptmyces scabiei, respectively. The cytotoxic activity results of gypsogenic acid in GM7492A cells (human fibroblasts) indicated that the substance promoted toxic effects in the strain only at higher concentrations (above of 500 µg/mL – 1,027.3 µM)

    Light means power: harnessing light spectrum and UV-B to enhance photosynthesis and rutin levels in microtomato plants

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    Urban vertical agriculture with lighting system can be an alternative green infrastructure to increase local food production irrespective of environmental and soil conditions. In this system, light quality control can improve the plant physiological performance, well as induce metabolic pathways that contribute to producing phenolic compounds important to human health. Therefore, this study aimed to evaluate the influence of RBW (red, blue and white) and monochromatic (red and blue; R and B, respectively) light associated or not with UV-B on photosynthetic performance and phenolic compound production in microtomato fruits cultivated via vertical agriculture. The experimental design adopted was completely randomized, with six replicates illuminated with 300 µmol·m−2·s−1 light intensities (RBW, RBW + UV, B, B + UV, R, and R + UV), 12 h photoperiod, and 3.7 W·m−2 UV-B irradiation for 1 h daily for the physiological evaluations. Twenty-six days after the installation, gas exchange, chlorophyll a fluorescence and nocturnal breathing were evaluated. Fruits in different ripening stages (green, orange, and red) were collected from microtomato plants grown under with different light qualities, to evaluate the physiological performance. The identification and quantification of the phenolic compound rutin was also performed to investigate their metabolic response. This study identified that plants grown under B + UV had high photosynthetic rates (A=11.57 µmol·m−2·s−1) and the fruits at all maturation stages from plants grown under B and B + UV had high rutin content. Meanwhile, the activation of suppressive mechanisms was necessary in plants grown under R because of the high nocturnal respiration and unregulated quantum yield of the non-photochemical dissipation of the photosystem II. These results highlight the importance of selecting light wavelength for vegetable cultivation to produce fruits with a high content of specialized metabolites that influence color, flavor, and health promotion, which is of special interest to farmers using sustainable cropping systems

    Chemical composition and in vitro cytotoxicity of Corynespora olivacea (V18) associated with Vochysia divergens / Composição química e citotoxicidade in vitro de Corynespora olivacea (V18) associada a Vochysia divergens

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    Chemical investigation into the ethyl acetate extract of the endophytic fungus Corynespora olivacea (V18) associated with Vochysia divergens identified compounds 1 and 2. The compounds were characterized by spectroscopic methods including NMR (1D and 2D) and HRMS. The cytotoxicity of the crude extract and the isolated compounds against normal human lung fibroblast cells, lineage GM07492A, was evaluated by the XTT assay. To the best of our knowledge, this is the first chemical and biological screening of the cytotoxicity of C. olivacea derived from V. divergens

    Chemical composition and in vitro cytotoxicity of Corynespora olivacea (V18) associated with Vochysia divergens/ Composição química e citotoxicidade in vitro de Corynespora olivacea (V18) associada a Vochysia divergens

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    Chemical investigation into the ethyl acetate extract of the endophytic fungus Corynespora olivacea (V18) associated with Vochysia divergens identified compounds 1 and 2. The compounds were characterized by spectroscopic methods including NMR (1D and 2D) and HRMS. The cytotoxicity of the crude extract and the isolated compounds against normal human lung fibroblast cells, lineage GM07492A, was evaluated by the XTT assay. To the best of our knowledge, this is the first chemical and biological screening of the cytotoxicity of C. olivacea derived from V. divergens
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