4,085 research outputs found

    Role of protein kinase R in the killing of Leishmania major by macrophages in response to neutrophil elastase and TLR4 via TNF and IFN

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    In cutaneous leishmaniasis, Leishmania amazonensis activates macrophage double-stranded, RNA-activated protein kinase R (PKR) to promote parasite growth. In our study, Leishmania major grew normally in RAW cells, RAW-expressing dominant-negative PKR (PKR-DN) cells, and macrophages of PKR-knockout mice, revealing that PKR is dispensable for L. major growth in macrophages. PKR activation in infected macrophages with poly I:C resulted in parasite death. Fifty percent of L. major-knockout lines for the ecotin-like serine peptidase inhibitor (ISP2; Δisp2/isp3), an inhibitor of neutrophil elastase (NE), died in RAW cells or macrophages from 129Sv mice, as a result of PKR activation. Inhibition of PKR or NE or neutralization of Toll-like receptor 4 or 2(TLR4 or TLR2) prevented the death of Δisp2/isp3. Δisp2/isp3 grew normally in RAW-PKR-DN cells or macrophages from 129Sv pkr−/−, tlr2−/−, trif−/−, and myd88−/− mice, associating NE activity, PKR, and TLR responses with parasite death. Δisp2/isp3 increased the expression of mRNA for TNF-α by 2-fold and of interferon ÎČ (IFNÎČ) in a PKR-dependent manner. Antibodies to TNF-α reversed the 95% killing by Δisp2/isp3, whereas they grew normally in macrophages from IFN receptor–knockout mice. We propose that ISP2 prevents the activation of PKR via an NE-TLR4-TLR2 axis to control innate responses that contribute to the killing of L. major.—Faria, M. S., Calegari-Silva, T. C., de Carvalho Vivarini, A., Mottram, J. C., Lopes, U. G., Lima, A. P. C. A. Role of protein kinase R in the killing of Leishmania major by macrophages in response to neutrophil elastase and TLR4 via TNFα and IFNÎČ

    Extracellular enolase of Candida albicans is involved in colonization of mammalian intestinal epithelium

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    Enolase is secreted by C. albicans and is present in its biofilms although its extracellular function is unknown. Here we show that extracellular enolase mediates the colonization of small intestine mucosa by C. albicans. Assays using intestinal mucosa disks show that C. albicans adhesion is inhibited, in a dose dependent mode, either by pretreatment of intestinal epithelium mucosa disks with recombinant C. albicans enolase (70% at 0.5 mg/ml enolase) or by pretreatment of C. albicans yeasts with anti-enolase antibodies (48% with 20 ”g antiserum). Also using flow cytometry, immunoblots of conditioned media and confocal microscopy we demonstrate that enolase is present in biofilms and that the extracellular enolase is not an artifact due to cell lysis, but must represent functional secretion of a stable form. This is the first direct evidence that C. albicans extracellular enolase mediates colonization on its primary translocation site. Also, because enolase is encoded by a single locus in C. albicans, its dual role peptide, as glycolytic enzyme and extracellular peptide, is a remarkable example of gene sharing in fungi

    New Brazilian pineapple leaf fibers for textile application: cottonization and dyeing performance

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    This work evaluates the dyeing performance associated with a cottonization and bleaching pretreatment of pineapple leaf fibers from two diferent species from Brazil: curaua (A. lucidus syn. A. erectifolius) and red pineapple (A. bracteatus (Lindl.) Schult. & Schult.f), aiming its application in textile materials for garments. Treated and untreated fibers were compared for their morphological, chemical, physical and color properties. The fibers underwent changes in their chemical and physical structural characteristics after pretreatment. The results of SEM, FTIR and whiteness index analysis indicated that the cottonization process improved the color and surface uniformity of fibers, reducing non-cellulosic matters, such as lignin and pectin. Treated fibers also presented low impurities content, i.e., oils, wax and fats (between 1.1 and 2.1%). However, compared to untreated fibers, treated curaua show an increase in impurities, supposedly caused by the removal of epidermal tissue from the fiber surface, which became the fiber bundle structure more accessible. Cottonization process also produced thinner, individualized and more resistant fiber bundles, which was evidenced by a decrease in linear density by 30 and 42% and an increase in tenacity by 12 and 23%. The dyeing behavior of fibers was investigated using blue, red and yellow reactive dyes. Fibers of both species demonstrated good dyeing behavior, with K/S values compatible with textile application standards (between 4 and 11) and an excellent color fastness to laundering.This work is also supported by FEDER funds through the Competitivity Factors Operational Programme-COMPETE and by national funds through FCT-Foundation for Science and Technology within the scope of the project POCI-01-0145-FEDER-007136

    Experimental and computational study of the energetics of hydantoin and 2-thiohydantoin

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    This work reports an experimental and a theoretical study of two imidazolidine derivatives, hydantoin (CAS No. 461-72-3) and 2-thiohydantoin (CAS No. 503-87-7). The standard (p degrees = 0.1 MPa) molar energies of combustion of hydantoin and 2-thiohydantoin were measured by static and rotating bomb combustion calorimetry, respectively. The standard molar enthalpies of sublimation, at T = 298.15 K, were derived from the temperature dependence of the vapour pressures of these compounds, measured by the Knudsen-effusion technique, and from high temperature Calvet microcalorimetry. The conjugation of these experimental results enables the calculation of the standard molar enthalpies of formation in the gaseous state, at T = 298.15 K, which are discussed in terms of structural contributions. We have also estimated the gas-phase enthalpy of formation from high-level ab initio molecular orbital calculations at the G3MP2B3 level of theory, being the computed values in good agreement with the experimental ones. Furthermore, this composite approach was also used to obtain information about the gas-phase basicities, proton and electron affinities and adiabatic ionization enthalpies

    Estudos soroepidemiológico e molecular de infecção por EV-71 no Estado do Parå, Brasil

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    In many countries, the Enterovirus 71 (EV-71) Picornaviridae family is associated to hand, foot and mouth disease in addition to acute neurological diseases while in Brazil these viruses are more closely associated to the latter group. The aim of this research was to use the first EV-71 isolate of the Northern region of Brazil in molecular and seroepidemiologic studies. Two (2.2%) out of 88 stool samples (44 cases of AFP), collected from January 1998 to December 2000 were positive for EV-71 isolation (73442/PA/99). Nucleotide sequence of the gen that codifies the VP1 protein showed that isolate 73442/PA/99 was similar to the EV-71 strains belonging to genotype B - more closely identified with EV-71 from North America. Neutralization test with 389 sera samples collected from January 1998 to November 2001, from individuals ranging from 0 to 15 years of age living in the city of BelĂ©m, State of ParĂĄ showed the following results in relation to isolate 73442/PA/99 and prototype BrCr: a total of 207 individuals (53.2%) had neutralization antibodies to both viruses, 167 (42.9%) had no antibodies and 15 showed the presence of neutralizing antibodies to one of the two viruses. Only 20.2% of the children aged 0 to 3 had neutralizing antibodies to EV-71, indicating that these children were more susceptible to the infection. Both the seroprevalence study and VP1 sequencing were important to demonstrate the spread and the molecular pattern of the EV-71 circulating in the Northern Region of Brazil.Em muitos paĂ­ses, o EnterovĂ­rus 71 (EV-71) famĂ­lia Picornaviridae Ă© associado a doença de pĂ©-mĂŁo e boca e doenças neurolĂłgicas agudas enquanto que no Brasil esse vĂ­rus estĂĄ mais associado Ă s Ășltimas. O objetivo desta pesquisa foi utilizar em estudos moleculares e soroepidemiolĂłgicos, o primeiro isolamento de EV-71 obtido na regiĂŁo norte do Brasil. No perĂ­odo de janeiro de 1998 a dezembro de 2000 foram coletadas 88 amostras (44 casos de PFA) de fezes das quais, duas (2,2%) foram positivas para EV-71 (73442/PA/99). A seqĂŒĂȘncia de nucleotĂ­deos do gen que codifica a proteĂ­na VP1 mostrou que o isolado 73442/PA/99 foi similar Ă s cepas de EV-71 pertencentes ao grupo B- mais prĂłxima das norte americanas. Teste de neutralização com 389 amostras de soro colhidas no perĂ­odo de janeiro de 1998 a novembro de 2001, de indivĂ­duos com idade de 0 a 15 anos residentes na cidade de BelĂ©m, Estado do ParĂĄ mostrou os seguintes resultados em relação ao isolado 73442/PA/99 e ao protĂłtipo BrCr: 207 indivĂ­duos (53,2%) tinham anticorpos neutralizantes para ambos os vĂ­rus, 167 (42,9%) nĂŁo tinham anticorpos e 15 tinham anticorpos para um dos dois vĂ­rus. Somente 20,2% das crianças com idade de 0 a 3 anos tinham anticorpos neutralizantes para EV-71, indicando que essas crianças estavam mais suscetĂ­veis Ă  infecção. Tanto o estudo de soroprevalĂȘncia quanto o de sequenciamento da VP1 foram importantes para demonstrar a propagação e o padrĂŁo molecular do EV-71 circulante na regiĂŁo norte do Brasil

    Enterotype May Drive the Dietary-Associated Cardiometabolic Risk Factors

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    Analyses of typical bacterial clusters in humans named enterotypes may facilitate understanding the host differences in the cardiometabolic profile. It stills unknown whether the three previously described enterotypes were present in populations living below the equator. We examined how the identification of enterotypes could be useful to explain the dietary associations with cardiometabolic risk factors in Brazilian subjects. In this cross-sectional study, a convenience sample of 268 adults (54.2% women) reported their dietary habits and had clinical and biological samples collected. In this study, we analyzed biochemical data and metagenomics of fecal microbiota (16SrRNA sequencing, V4 region). Continuous variables were compared using ANOVA, and categorical variables using chi-square test. Vsearch clustered the operational taxonomic units, and Silva Database provided the taxonomic signatures. Spearman coefficient was used to verify the correlation between bacteria abundances within each enterotype. One hundred subjects were classified as omnivore, 102 lacto-ovo-vegetarians, and 66 strict vegetarians. We found the same structure as the three previously described enterotypes: 111 participants were assigned to Bacteroides, 55 to Prevotella, and 102 to Ruminococcaceae enterotype. The Prevotella cluster contained higher amount of strict vegetarians individuals than the other enterotypes (40.0 vs. 20.7 and 20.6, p = 0.04). Subjects in this enterotype had a similar anthropometric profile but a lower mean LDL-c concentration than the Bacteroides enterotype (96 +/- 23 vs. 109 +/- 32 mg/dL, p = 0.04). We observed significant correlations between bacterial abundances and cardiometabolic risk factors, but coefficients differed depending on the enterotype. In Prevotella enterotype, Eubacterium ventriosum (r BMI = -0.33, p = 0.03, and r HDL-c = 0.33, p = 0.04), Akkermansia (r 2h glucose = -0.35, p = 0.02), Roseburia (r BMI = -0.36, p = 0.02 and r waist = -0.36, p = 0.02), and Faecalibacterium (r insulin = -0.35, p = 0.02) abundances were associated to better cardiometabolic profile. The three enterotypes previously described are present in Brazilians, supporting that those bacterial clusters are not population-specific. Diet-independent lower LDL-c levels in subjects from Prevotella than in other enterotypes suggest that a protective bacterial cluster in the former should be driving this association. Enterotypes seem to be useful to understand the impact of daily diet exposure on cardiometabolic risk factors. Prospective studies are needed to confirm their utility for predicting phenotypes in humans.FAPESPUniv Sao Paulo, Sch Publ Hlth, Dept Epidemiol, Sao Paulo, BrazilFundacao Oswaldo Cruz, Rene Rachou Res Ctr, Belo Horizonte, MG, BrazilUniv Fed Sao Paulo, Dept Prevent Med, Sao Paulo, BrazilUniv Sao Paulo, Sch Med, Heart Inst Incor, Lab Genet & Mol Cardiol, Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Prevent Med, Sao Paulo, BrazilFAPESP: 2012/12626-9FAPESP: 2012/03880-9Web of Scienc

    Cold atmospheric plasma, a novel approach against bladder cancer, with higher sensitivity for the high-grade cell line

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    Antitumor therapies based on Cold Atmospheric Plasma (CAP) are an emerging medical field. In this work, we evaluated CAP effects on bladder cancer. Two bladder cancer cell lines were used, HT-1376 (stage III) and TCCSUP (stage IV). Cell proliferation assays were performed evaluating metabolic activity (MTT assay) and protein content (SRB assay). Cell viability, cell cycle, and mitochondrial membrane potential (Δψm) were assessed using flow cytometry. Reactive oxygen and nitrogen species (RONS) and reduced glutathione (GSH) were evaluated by fluorescence. The assays were carried out with different CAP exposure times. For both cell lines, we obtained a significant reduction in metabolic activity and protein content. There was a decrease in cell viability, as well as a cell cycle arrest in S phase. The Δψm was significantly reduced. There was an increase in superoxide and nitric oxide and a decrease in peroxide contents, while GSH content did not change. These results were dependent on the exposure time, with small differences for both cell lines, but overall, they were more pronounced in the TCCSUP cell line. CAP showed to have a promising antitumor effect on bladder cancer, with higher sensitivity for the high-grade cell line.info:eu-repo/semantics/publishedVersio

    Visceral leishmaniasis in the State of MaranhĂŁo, Brazil: evolution of an epidemic

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    The authors provide a brief report on the historical evolution of visceral leishmaniasis in the State of MaranhĂŁo, Brazil, evaluating possible factors for growth of the disease in the State and control measures by the Brazilian Ministry of Health to integrate health services finto the maintenance of control programs.Os autores fazem um breve relato da evolução histĂłrica da leishmaniose visceral no Estado do MaranhĂŁo, Brasil, avaliando as possĂ­veis causas da expansĂŁo da referida doença no Estado, assim como as medidas de controle adotadas pelo MinistĂ©rio da SaĂșde objetivando a diminuição da incidĂȘncia da mesma.Universidade Federal do MaranhĂŁo Faculdade de Medicina Departamento de PatologiaEscola Paulista de MedicinaUNIFESP, EPMSciEL

    Biochemical characterization and cytotoxic effect of the skin secretion from the red-spotted Argentina frog Argenteohyla siemersi (Anura: Hylidae)

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    Background: Argenteohyla siemersi (red-spotted Argentina frog) is a casque-headed tree frog species belonging to the Hylidae family. This species has a complex combination of anti-predator defense mechanisms that include a highly lethal skin secretion. However, biochemical composition and biological effects of this secretion have not yet been studied. Methods: The A. siemersi skin secretion samples were analyzed by mass spectrometry and chromatographic analysis (MALDI-TOF/MS, RP-HPLC and GC-MS). Proteins were also studied by SDS-PAGE. Among the biological activities evaluated, several enzymatic activities (hemolytic, phospholipase A2 , clotting, proteolytic and amidolytic) were assessed. Furthermore, the cytotoxic activity (cytolysis and fluorescence staining) was evaluated on myoblasts of the C2C12 cell line. Results: The MALDI-TOF/MS analysis identified polypeptides and proteins in the aqueous solution of A. siemersi skin secretion. SDS-PAGE revealed the presence of proteins with molecular masses from 15 to 55 kDa. Steroids, but no alkaloids or peptides (less than 5 kDa), were detected using mass spectrometry. Skin secretion revealed the presence of lipids in methanolic extract, as analyzed by CG-MS. This secretion showed hemolytic and phospholipase A2 activities, but was devoid of amidolytic, proteolytic or clotting activities. Moreover, dose-dependent cytotoxicity in cultured C2C12 myoblasts of the skin secretion was demonstrated. Morphological analysis, quantification of lactate dehydrogenase release and fluorescence staining indicated that the cell death triggered by this secretion involved necrosis. Conclusions: Results presented herein evidence the biochemical composition and biological effects of A. siemersi skin secretion and contribute to the knowledge on the defense mechanisms of casque-headed frogs.Fil: Fusco, Luciano Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Båsica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Båsica y Aplicada del Nordeste Argentino; ArgentinaFil: Cajade, Rodrigo. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Departamento de Biología. Laboratorio de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Piñeiro, Jose Miguel. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Departamento de Biología. Laboratorio de Herpetología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Torres, Ana M.. Universidad Nacional del Nordeste; ArgentinaFil: da Silva, Igor R. F.. Universidade Estadual de Campinas; BrasilFil: Hyslop, Stephen. Universidade Estadual de Campinas; BrasilFil: Leiva, Laura Cristina Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Båsica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Båsica y Aplicada del Nordeste Argentino; ArgentinaFil: Pimenta, Daniel C.. Governo do Estado de Sao Paulo. Secretaria da Saude. Instituto Butantan; BrasilFil: Bustillo, Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Båsica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Båsica y Aplicada del Nordeste Argentino; Argentin
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