187 research outputs found

    Antiproliferative Oleanane Saponins from Dizygotheca elegantissima

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    Four new oleanane saponins (1-4), together with three known saponins, were isolated from the aerial parts of Dizygotheca elegantissima R. Vig. & Guillaumin. Their structures were elucidated by 1D and 2D NMR experiments including 1D TOCSY, DQF-COSY, HSQC, and HMBC spectroscopy, as well as ESIMS analysis. The antiproliferative activity of all isolated compounds was evaluated

    Macroalgae suspensions prepared by physical treatments: Effect of polysaccharide composition and microstructure on the rheological properties

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    The use of macroalgae in food products is growing due to their techno-functionality and nutritional properties. In this context, an increased understanding of the rheological properties which are relevant for manufacturing and texture is needed. Here we investigated the impact of thermal and mechanical treatments, including high pressure homogenisation (HPH), on the polysaccharide composition, microstructure, and rheological properties of brown algae Laminaria digitata suspensions (5 wt %). Monosaccharide analysis and immunolabeling of alginate in combination with confocal laser scanning microscopy, revealed a sequential release of different polysaccharides as result of the applied shear. Results showed that thermal treatment (70 \ub0C 1 h) and mild shear lead to suspensions of clusters of cells and release of fucoidan and laminarin into the liquid phase, conferring shear thinning properties to the suspensions. High pressure homogenisation was able to completely break the macroalgae cells, reducing particle size and releasing other soluble polysaccharides, in particular alginate, conferring gel properties (G\u27>G\u27\u27) to the suspensions. This study contributes to the knowledge of how to design sustainable, innovative and nutritious liquid/semiliquid food products containing macroalgae biomass

    Bioactive Limonoids from the Leaves of Azaridachta indica (Neem)

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    Eight new limonoids (1−8) and one new phenol glycoside (9), along with six known compounds, were isolated from the leaves of Azaridachta indica. The structures of 1−9 were elucidated on the basis of spectroscopic data analysis. Compounds isolated were assayed for their cytotoxicity against different cancer cell lines. Moreover, their ability to interact with the molecular chaperone Hsp90, affecting its biological activity, was tested

    A setup for integral measurements of multiple scattering angular distributions by 10- to 100-keV electrons

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    A dedicated setup has been developed to study the angular distributions of electrons traversing thin films employing the low-energy beam available from the gun of the São Paulo Microtron. In this first stage, only integral measurements are possible using the fraction of the electron beam current collected in a Faraday cup and in a ring surrounding the entrance of the former. The overall normalisation is provided by measuring the beam current collected by the scattering chamber as well, thus covering the full solid angle. In this work, important construction specifications are presented. The experience gained by operating this system is also discussed regarding its critical aspects like: avoiding cross talk between the cup and the ring both at the physical and electronic levels, measurements of small charges deposited on large objects (the chamber in particular), and conditioning of the various surfaces involved. Finally, some selected results are compared to the well-known theory by Goudsmit and Saunderson with good agreement

    The hidden hypothesis : a disseminated tuberculosis case

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    Case presentation: 77-year-old former smoker admitted because of fatigue and abdominal distention. Past medical history positive for two previous hospitalizations for pericardial and pleural effusions (no diagnosis achieved). At admission erythrocyte sedimentation rate was 122 mm per hour. Baseline investigations revealed ascitic, pleural and pericardial effusion. Effusions were tapped: neoplastic cells and acid-fast bacilli (AFB) were not identified, aerobic and mycobacterial culture resulted negative. QuantiFERON TB-Gold test was negative. Total body PET-CT and autoimmunity panel were negative. A neoplastic process was considered the most likely explanation. Before signing off the patient to comfort care, a reassessment was performed and an exposure to tuberculosis during childhood was documented. Because of constrictive pericarditis, pericardiectomy was performed: histologic examination showed chronic pericardial inflammation without granulomas, but Ziehl-Neelsen stain identified AFB and PCR was positive for Mycobacterium tuberculosis complex. Patient was started on anti-TB therapy with resolution of the effusions in the following months. Genes associated with defects in innate immunity were sequences and dentritic cells were studied, but no alterations were identified. Discussion: A Bayesian approach to clinical decision making should be recommended. Interpretation of diagnostic tests should take into account the imperfect diagnostic performance of the majority of these tests. Further studies to investigate genetic susceptibility to tuberculosis are needed

    Aspectos epidemiológicos e ecológicos relacionados à malária na área de influência do lago da Represa de Porto Primavera, região oeste do Estado de São Paulo, Brasil

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    A study was carried out in the area of influence of the Porto Primavera Hydroelectric Power Station, in western São Paulo State, to investigate ecological and epidemiological aspects of malaria in the area and monitor the profile of the anopheline populations following the environmental changes brought about by the construction of the lake. Mosquitoes captured were analyzed by standardized indicator species analysis (ISA) before and during different flooding phases (253 m and 257 m elevations). The local human population was studied by means of parasitological (thin/thick blood smears), molecular (PCR) and serological tests. Serological tests consisted of Enzyme Linked Immunosorbent Assay (ELISA) with synthetic peptides of the circumsporozoite protein (CSP) from classic Plasmodium vivax, P. vivax variants (VK247 and "vivax-like"), P. malariae and P. falciparum and Indirect Immunofluorescence Assay (IFA) with asexual forms of P. vivax, P. malariae and P. falciparum. The results of the entomological survey indicated that, although the Anopheles darlingi population increased after the flooding, the population density remained very low. No malaria, parasite infection or DNA was detected in the inhabitants of the study area. However, there was a low frequency of antibodies against asexual forms and a significant prevalence of antibodies against P. vivax, P. vivax variants, P. falciparum and P. malariae; the presence of these antibodies may result from recent or less recent contact with human or simian Plasmodium (a parallel study in the same area revealed the existence of a sylvatic cycle). Nevertheless, these results suggest that, as in other places where malaria is present and potential vectors circulate, the local epidemiological conditions observed could potentially support the transmission of malaria in Porto Primavera Lake if infected individuals are introduced in sufficient numbers. Further studies are required to elucidate the phenomena described in this paper.Foi realizada pesquisa na área de influência do lago da Usina Hidrelétrica de Porto Primavera, região oeste do Estado de São Paulo, para estudar aspectos ecológicos e epidemiológicos da malária na localidade e acompanhar o perfil das populações de anofelinos frente às mudanças decorrentes do impacto ambiental pela formação do lago. Mosquitos capturados foram analisados pelo Índice de Abundância de Espécies Padronizado (IAEP), antes e durante o enchimento do reservatório (cotas 253 e 257 m). A população humana local foi estudada por meio de teste parasitológico (gota espessa e esfregaço sangüíneo), testes moleculares (PCR) e testes sorológicos. A sorologia consistiu na reação de ELISA com peptídeos sintéticos correspondentes à porção repetitiva da proteína circumsporozoíta (CSP) de Plasmodium vivax clássico, e suas variantes VK247 e "vivax-like", P. malariae e P. falciparum; e reação de Imunofluorescência Indireta (RIFI) com formas assexuadas de P. vivax, P. malariae e P. falciparum. Os resultados do estudo entomológico indicaram que, embora a população de Anopheles darlingi tenha aumentando após o enchimento, permaneceu em baixa densidade. Não foi detectada malária nem a presença de parasitos ou de DNA parasitário nos habitantes estudados. No entanto, foi observada baixa freqüência de anticorpos contra formas assexuadas e significativa prevalência de anticorpos contra esporozoítos de P. vivax e suas variantes, P. falciparum e P. malariae, que poderiam decorrer de contatos prévios, recentes ou não, com plasmódios humanos ou símios (o ciclo silvestre foi evidenciado em estudo paralelo realizado na mesma área). Por outro lado, estes resultados sugerem que, como em outros lugares onde existem vetores potenciais da malária, as condições epidemiológicas poderiam potencialmente permitir a transmissão da malária na área de influência do lago de Porto Primavera, se indivíduos infectados fossem introduzidos em número suficiente. Estudos adicionais deverão ser realizados para elucidar os fenômenos relatados neste artigo

    Block Copolymers‐Based Nanoporous Thin Films with Tailored Morphology for Biomolecules Adsorption

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    The adsorption of myoglobin (Mb) onto nanoporous thin films build up using block‐copolymers (BCPs) is analyzed. The nanoporous thin films, fabricated by exploiting self‐assembly of lamellar BCPs and the concept of sacrificial block, are characterized by a well‐defined morphology containing nanochannels of width ≈20 nm delimited by polystyrene (PS) domains, decorated with pendant poly(ethylene oxide) (PEO) chains. The adsorption of Mb onto the nanoporous material is studied by means of UV–visible spectroscopy, quartz crystal microbalance, and neutron reflectometry measurements. In order to determine the role of nanopores, experiments are also conducted by using supports made of nonporous PS thin films and nude glass slides. The results indicate that the BCP‐nanoporous material exhibits a remarkably higher adsorption capability than PS and glass. As PEO exhibits a low degree of protein adsorption, this result may be essentially attributed to the presence of the nanopores. The large surface area, the opened pore structure, and the trapping effect of the pores are the main factors determining the increased Mb adsorption capability of the BCP‐based support. Yet, the presence of PEO chains decorating the PS walls at porous surface does not prevent Mb biomolecules to establish good interactions with the support
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