36 resultados para antifungal glycoalkaloids


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Bananas (Musa spp.) are highly perishable fruit of notable economic and nutritional relevance. Because the identification of proteins involved in metabolic pathways could help to extend green-life and improve the quality of the fruit, this study aimed to compare the proteins of banana pulp at the pre-climacteric and climacteric stages. The use of two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) revealed 50 differentially expressed proteins, and comparing those proteins to the Mass Spectrometry Protein Sequence Database (MSDB) identified 26 known proteins. Chitinases were the most abundant types of proteins in unripe bananas, and two isoforms in the ripe fruit have been implicated in the stress/defense response. In this regard, three heat shock proteins and isoflavone reductase were also abundant at the climacteric stage. Concerning fruit quality, pectate lyase, malate dehydrogenase, and starch phosphorylase accumulated during ripening. In addition to the ethylene formation enzyme amino cyclo carboxylic acid oxidase, the accumulation of S-adenosyl-L-homocysteine hydrolase was needed because of the increased ethylene synthesis and DNA methylation that occurred in ripening bananas. Differential analysis provided information on the ripening-associated changes that occurred in proteins involved in banana flavor, texture, defense, synthesis of ethylene, regulation of expression, and protein folding, and this analysis validated previous data on the transcripts during ripening. In this regard, the differential proteomics of fruit pulp enlarged our understanding of the process of banana ripening. (C) 2012 Elsevier B.V. All rights reserved.

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Background: Fungal infections are emerging as an important cause of human disease, especially among hospitalized patients with serious underlying disease and several risk factors. Aims: To evaluate epidemiological and clinical characteristics of patients with nosocomial candidiasis in university hospitals in Cuiaba - MT, Brazil. Methods: A descriptive study of 91 patients admitted to university hospitals in Cuiaba - MT, with clinical and laboratory diagnosis of nosocomial candidiasis, over a 20-month period. Results: A rate for nosocomial infections by Candida spp. of 5 per 1000 admissions, proportional mortality of 14.4% and lethality of 53.8% were determined. The patient age ranged from 29 days to 82 years-old, among which, 74.7% were adults and 25.3% children. The intensive care units contributed with the highest number of cases of infection by Candida spp. (69.2%). The most important underlying disease was gastrointestinal tract disease (11%). Prematurity and low birth weight were the most important risk factors among newborns. The use of antibiotics, invasive procedures, H-2 blockers, multiple blood transfusions and stay length of >= 21 days were the most frequent risk factors among adults. Candida albicans was the most common species in all cases. Conclusions: In this study, C. albicans was the most frequently detected species in candidiasis and risk factors increased the susceptibility of hospitalized patients to acquiring a nosocomial infection by Candida spp. (C) 2011 Revista Iberoamericana de Micologia. Published by Elsevier Espana, S.L. All rights reserved.

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Background: Candidemia affects patient populations from neonates to the elderly. Despite this, little information is available about the epidemiology of candidemia in elderly patients. Methods: We performed a retrospective analysis of 987 episodes of candidemia in adults (>14 years of age) from the databases of three laboratory-based surveys of candidemia performed at 14 tertiary care hospitals. Patients aged >= 60 years were considered elderly (group 1, n = 455, 46%) and were compared to younger patients (group 2, n = 532, 54%) regarding demographics, underlying diseases, comorbidities, exposure to medical procedures, species, treatment, and outcome. Results: The median APACHE II score was significantly higher in the elderly patients (19 vs. 15, p = 0.03). Variables that were observed significantly more frequently in elderly patients included admission to an intensive care unit, diabetes mellitus, renal failure, cardiac disease, lung disease, receipt of antibiotics or H2 blockers, insertion of a central venous catheter, mechanical ventilation, and candidemia due to Candida tropicalis. The 30-day mortality of elderly patients was significantly higher than that of younger patients (70% vs. 45%, p < 0.001). Factors associated with higher mortality by multivariate analysis included APACHE II score and being in group 1 (elderly). Factors associated with mortality in elderly patients were lung disease and the receipt of mechanical ventilation. Conclusions: Elderly patients account for a substantial proportion of patients with candidemia and have a higher mortality compared to younger patients. (C) 2012 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

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Limited information is available regarding the modulation of genes involved in the innate host response to Paracoccidioides brasiliensis, the etiologic agent of paracoccidioidomycosis. Therefore, we sought to characterize, for the first time, the transcriptional profile of murine bone marrow-derived dendritic cells (DCs) at an early stage following their initial interaction with P. brasiliensis. DCs connect innate and adaptive immunity by recognizing invading pathogens and determining the type of effector T-cell that mediates an immune response. Gene expression profiles were analyzed using microarray and validated using real-time RT-PCR and protein secretion studies. A total of 299 genes were differentially expressed, many of which are involved in immunity, signal transduction, transcription and apoptosis. Genes encoding the cytokines IL-12 and TNF-alpha, along with the chemokines CCL22, CCL27 and CXCL10, were up-regulated, suggesting that P. brasiliensis induces a potent proinflammatory response in DCs. In contrast, pattern recognition receptor (PRR)-encoding genes, particularly those related to Toll-like receptors, were down-regulated or unchanged. This result prompted us to evaluate the expression profiles of dectin-1 and mannose receptor, two other important fungal PRRs that were not included in the microarray target cDNA sequences. Unlike the mannose receptor, the dectin-1 receptor gene was significantly induced, suggesting that this beta-glucan receptor participates in the recognition of P. brasiliensis. We also used a receptor inhibition assay to evaluate the roles of these receptors in coordinating the expression of several immune-related genes in DCs upon fungal exposure. Altogether, our results provide an initial characterization of early host responses to P. brasiliensis and a basis for better understanding the infectious process of this important neglected pathogen.

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Schistosomiasis is one of the most important parasitic infections in humans that occur in many tropical and subtropical countries. Currently, the control of schistosomiasis rests with a single drug, praziquantel, which is effective against adult worms but not the larval stages. Recent studies have shown that piplartine, an amide isolated from plants of the genus Piper (Piperaceae), reveals interesting antischistosomal properties against Schistosoma mansoni adult worms. Here, we report the in vitro antischistosomal activity of piplartine on S. mansoni schistosomula of different ages (3 h old and 1, 3, 5, and 7 days old), and examine alterations on the tegumental surface of worms by means of confocal laser scanning microscopy. Piplartine at a concentration of 7.5 mu M caused the death of all schistosomula within 120 h. The lethal effect occurred in a dose-dependent manner and was also dependent on the age of the parasite. Microscopy observation revealed extensive tegumental destruction, including blebbing, granularity, and a shorter body length. This report provides the first evidence that piplartine is able to kill schistosomula of different ages and reinforce that piplartine is a promising compound that could be used for the development of new schistosomicidal agent. (c) 2012 Elsevier Inc. All rights reserved.

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The biofilms formed by opportunistic yeasts serve as a persistent reservoir of infection and impair the treatment of fungal diseases. The aim of this study was to evaluate photodynamic inactivation (PDI) of biofilms formed by Candida spp. and the emerging pathogens Trichosporon mucoides and Kodamaea ohmeri by a cationic nanoemulsion of zinc 2,9,16,23-tetrakis(phenylthio)-29H,31H-phthalocyanine (ZnPc). Biofilms formed by yeasts after 48 h in the bottom of 96-well microtiter plates were treated with the photosensitizer (ZnPc) and a GaAlAs laser (26.3 J cm(-2)). The biofilm cells were scraped off the well wall, homogenized, and seeded onto Sabouraud dextrose agar plates that were then incubated at 37A degrees C for 48 h. Efficient PDI of biofilms was verified by counting colony-forming units (CFU/ml), and the data were submitted to analysis of variance and the Tukey test (p < 0.05). All biofilms studied were susceptible to PDI with statistically significant differences. The strains of Candida genus were more resistant to PDI than emerging pathogens T. mucoides and K. ohmeri. A mean reduction of 0.45 log was achieved for Candida spp. biofilms, and a reduction of 0.85 and 0.84, were achieved for biofilms formed by T. mucoides and K. ohmeri, respectively. Therefore, PDI by treatment with nanostructured formulations cationic zinc 2,9,16,23- tetrakis (phenylthio)- 29H, 31H- phthalocyanine (ZnPc) and a laser reduced the number of cells in the biofilms formed by strains of C. albicans and non-Candida albicans as well the emerging pathogens T. mucoides and K. ohmeri.