59 research outputs found

    Development of Cutaneous Bioadhesive Ureasil-Polyether Hybrid Films

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    The hydrolysis and condensation reactions involved in synthesis of ureasil-polyether films influence the film formation time and the number of chemical groups able to form hydrogen bonds, responsible for the bioadhesion, with the biological substrate. The objective of this work was to study the influence of the use of an acid catalyst (hydrochloric acid) and a basic catalyst (ammonium fluoride) in the hydrolysis and condensation reactions on the time formation and bioadhesion of ureasil-polyether films. The toxicity of the films was evaluated. The MTT assay has shown cell viability of human skin keratinocytes higher than 70% of all analyzed materials suggesting low cytotoxicity. The bioadhesion of the films is strongly dependent on the viscosity and hydrophilic/hydrophobic balance of the polyether chains used to synthetize the hybrid molecules. The use of acid catalyst promotes the formation of less viscous films with higher bioadhesion. The hybrids formed by more hydrophilic PEO chains are more bioadherent, since they can interact more efficiently with the water present in the stratum corneum increasing the bioadhesion. Due to their low toxicity and high bioadhesion, the ureasil-PEO films obtained by using HCl as catalyst agent are good candidates for application to the skin as bioadhesive films

    Cytotoxic Activity of Baccharis trimera (Less.) DC. Essential Oil in Tumor Cell Lines and its Role in Associated Death Mechanisms

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    This study evaluated the potential of Baccharis trimera essential oil (EO) and its components in cancer therapy through the application of cytotoxicity and cell death assays. Using gas chromatography analysis, the major components of the aerial parts of the essential oil were identified as (E)-caryophyllene (18.9%), bicyclogermacrene (15.6%), and germacrene D (10.5%). Baccharis trimera essential oil (5.8 μg/mL) and α-humulene (7.8 μg/mL) presented strong cytotoxic activity, while (E)-caryophyllene (11.5 μg/mL) and caryophyllene oxide (> 100.0 μg/mL) showed moderate and low activities, respectively, against MCF-7 cell lines. Against HepG2 cell lines, B. trimera essential oil (10.4 μg/mL), α-humulene (17.1 μg/mL), and caryophyllene oxide (19.4 μg/mL) exhibited moderate activity, while (E)-caryophyllene (52.3 μg/mL) displayed low activity against HepG2 cell lines. The selectivity index values of EO (MCF-7 and HepG2), α-humulene and (E)-caryophyllene (MCF-7), and caryophyllene oxide (HepG2) were found between 1.1 and 2.8, compared with MCF-10A cells. The annexin-V and Hoechst / propidium iodide assays performed with essential oil, (E)-caryophyllene, α-humulene, and caryophyllene oxide showed apoptosis and necrosis mechanisms for all cell lines. Based on these findings, B. trimera essential oil and its components can be considered as potential therapeutic agents against cancer

    Scavenging Activity on Reactive Oxygen Species with Biological Relevance by Varronia curassavica

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    Varronia curassavica Jacq. is a medicinal plant found in Brazil used as anti-inflammatory. Here, we investigated the in vitro antioxidant activity of 70 % ethanol extract of V. curassavica leaves on synthetic radicals (ABTS•+/DPPH•) and reactive oxygen species (O2•-, ROO•, HOCl/OCl-, H2O2), besides its in vitro cytotoxicity. The extract was characterized by UPLC-ESI-QToF-MSE and the annotated compounds were one hydroxybenzoic acid, five phenylpropanoids, and three glycosylated quercetin derivatives, being the main compound rosmarinic acid or its isomer. The antioxidant activity was very promising in all tests, highlighting on the capture of O2•-, which EC50 value was three times lower than Trolox. This activity may be due to the presence of the major compounds, all phenolic compounds. The extract also presented low cytotoxicity. Thus, the extract from V. curassavica leaves has great potential as an antioxidant

    Papilomavirus Humano (HPV) - Um estudo de revisao

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    Human Papillomaviruses (HPVs) are epitheliotropic viruses, that induce benign and malignant lesions on several body sites. It's a small circular DNA virus, non-enveloped and 75 types have been identified. Frequently HPV 6, 11 (benign lesions) and 16, 18 (malignant lesions) are occurred on mucosa. The infection takes place at the basal layer cells with microlesions, when the virus enters into the cells and looses the capsid. The benign HPV types is associated to cell's genome in epissomal way. In malignant lesions, it integrates into the cell's DNA. HPV viruses are sexually transmitted and responsable for malignant cell transformation. Thus this viruses have an extremely epidemiologic importance. This paper reports a HPV review study about: epidemiology, diagnostic methods and treatment to papillomavirus infection

    Investigação do papilomavirus humano (HPV) por imuno-histoquimica e hibridização "in situ" em biopsias endoscopicas de esofago

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    Orientadores: Miriam A. S. Trevisan, Jose VassalloTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias MedicasResumo: O papiloma vírus humano (HPV) tem sido descrito como um fator de risco para o desenvolvimento de lesões benignas e malignas no esôfago, sendo os tipos mais frequentes os HPVs 6, 11, 16, 18, 31, 33 e 35. No presente trabalho, selecionamos 49 casos de biópsias endoscópicas de esôfago coradas por hematoxilina-eosina. que continham graus variados de atipia coilocitótica (coilocitose, discariose, bi ou multinucleação). Esses casos foram submetidos às reações de imuno-histoquímica e hibridização " in situ " com sondas biotiniladas 6/11, 16/18, 31/33/35 (Kit Viratype-DIGENE). Os resultados para os casos estudados foram negativos, com controles positivos de forte sinal, por ambos os métodos. Assim, é possível que as alterações morfológicas do epitélio escamoso do esôfago possam não ser de origem viral e outros fatores devem ser considerados como potencialmente responsáveis por essas alteraçõesAbstract: Human Papillomavirus has been describe as a risk factor to benign and malign esophageallesions. The HPV s eommons in esophageal epithelium are 6, 11, 16, 18, 31, 33 and 35. We had select fourty nine endoscopie biopsies which histologic analysis had show koilocytotic atypia in different grades. We has use immunohistochemical and in situ hibridization reactions with commercially biotynilated probes 6/11, 16/18 and 31/33/35 (Viratype probe set.- DIGENE). We couldn't find HPV's antigen or DNA in any fourty nine samples. Then, our studies suggest other factors to development of esophageal tissues alterationsDoutoradoDoutor em Ciências Médica

    Synergistic effect of photodynamic therapy and cisplatin: a novel approach for cervical cancer

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    Cervical cancer is a neoplasia primarily caused by Human papillomavirus (HPV) infection. Current treatment modalities involve cisplatin, a potent chemotherapeutic agent with severe adverse effects. Photodynamic therapy (PDT) is a promising modality for the treatment of cancer and infections, which has been associated with innovative therapeutic approaches, especially for the treatment of neoplasias. This study aimed to investigate the anticancer potential of PDT mediated by methylene blue (MB) or Photogem (PG) individually and combined with cisplatin in vitro. SiHa, C-33 A and HaCaT cells were incubated with MB, PG and/or cisplatin and received no further treatment or were irradiated with a 630 or a 660 nm LED light source at energy densities varying according to the photosensitizer (PS). The MTT assay was employed to assess cell viability. Both PS were effective in reducing cell viability with the cytotoxicity being dependent on the light dose. When compared to PDT groups, cisplatin was less effective. The cell viability of the combined therapy groups was significantly lower compared to monotherapies. The sequence of treatments (PDT + cisplatin/cisplatin + PDT) was important and had different results when varying the PS, but combination therapy resulted in an enhanced anticancer effect regardless of treatment protocol. (C) 2014 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Interaction of pathogenic fungi with host cells: Molecular and cellular approaches

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    This review provides an overview of several molecular and cellular approaches that are likely to supply insights into the host-fungus interaction. Fungi present intra- and/or extracellular host-parasite interfaces, the parasitism phenomenon being dependent on complementary surface molecules. The entry of the pathogen into the host cell is initiated by the fungus adhering to the cell surface, which generates an uptake signal that may induce its cytoplasmatic internalization. Furthermore, microbial pathogens use a variety of their surface molecules to bind to host extracellular matrix (ECM) components to establish an effective infection. on the other hand, integrins mediate the tight adhesion of cells to the ECM at sites referred to as focal adhesions and also play a role in cell signaling. The phosphorylation process is an important mechanism of cell signaling and regulation; it has been implicated recently in defense strategies against a variety of pathogens that alter host-signaling pathways in order to facilitate their invasion and survival within host cells. The study of signal transduction pathways in virulent fungi is especially important in view of their putative role in the regulation of pathogenicity. This review discusses fungal adherence, changes in cytoskeletal organization and signal transduction in relation to host-fungus interaction. (c) 2005 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved
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