83 research outputs found

    HSP‐enriched properties of extracellular vesicles involve survival of metastatic oral cancer cells

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    Cancer cells often secrete extracellular vesicles (EVs) that carry heat shock proteins (HSPs) with roles in tumor progression. Oral squamous cell carcinoma (OSCC) belongs to head and neck cancers (HNC) whose lymph-node-metastases often lead to poor prognosis. We have examined the EV proteome of OSCC cells and found abundant secretion of HSP90-enriched EVs in lymph-node-metastatic OSCC cells. Double knockdown of HSP90α and HSP90ÎČ, using small interfering RNA significantly reduced the survival of the metastatic OSCC cells, although single knockdown of each HSP90 was ineffective. Elevated expression of these HSP90 family members was found to correlate with poor prognosis of HNC cases. Thus, elevated HSP90 levels in secreted vesicles are potential prognostic biomarkers and therapeutic targets in metastatic OSCC

    Sharing More than Friendship — Nasal Colonization with Coagulase-Positive Staphylococci (CPS) and Co-Habitation Aspects of Dogs and Their Owners

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    BACKGROUND: Since the relationship between dogs and their owners has changed, and dogs moved from being working dogs to family members in post-industrial countries, we hypothesized that zoonotic transmission of opportunistic pathogens like coagulase positive staphylococci (CPS) is likely between dogs and their owners. METHODOLOGY/PRINCIPAL FINDINGS: CPS- nasal carriage, different aspects of human-to-dog relationship as well as potential interspecies transmission risk factors were investigated by offering nasal swabs and a questionnaire to dog owners (108) and their dogs (108) at a dog show in 2009. S. aureus was found in swabs of 20 (18.5%) humans and two dogs (1.8%), and spa types which correspond to well known human S. aureus lineages dominated (e.g. CC45, CC30 and CC22). Multilocus sequence typing (MLST) of the two canine strains revealed ST72 and ST2065 (single locus variant of ST34). Fifteen dogs (13.9%) and six owners (5.6%) harboured S. pseudintermedius, including one mecA-positive human isolate (MRSP). Pulsed field gel electrophoresis (PFGE) revealed that one dog/owner pair harboured indistinguishable S. pseudintermedius- isolates of ST33. Ten (48%) of the 21 S. pseudintermedius-isolates showed resistance towards more than one antimicrobial class. 88.9% of the dog owners reported to allow at least one dog into the house, 68.5% allow the dog(s) to rest on the sofa, 39.8% allow their dogs to come onto the bed, 93.5% let them lick their hands and 52.8% let them lick their face. Bivariate analysis of putative risk factors revealed that dog owners who keep more than two dogs have a significantly higher chance of being colonized with S. pseudintermedius than those who keep 1-2 dogs (p<0.05). CONCLUSIONS/RECOMMENDATIONS: In conclusion, CPS transmission between dog owners and their dogs is possible. Further investigation regarding interspecies transmission and the diverse adaptive pathways influencing the epidemiology of CPS (including MRSA and MRSP) in different hosts is needed

    Bayesian Approach to Model CD137 Signaling in Human M.tuberculosis in vitro Responses

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    Abstract Immune responses are qualitatively and quantitatively influenced by a complex network of receptor-ligand interactions. Among them, the CD137:CD137L pathway is known to modulate innate and adaptive human responses against Mycobacterium tuberculosis. However, the underlying mechanisms of this regulation remain unclear. In this work, we developed a Bayesian Computational Model (BCM) of in vitro CD137 signaling, devised to fit previously gathered experimental data. The BCM is fed with the data and the prior distribution of the model parameters and it returns theirposterior distribution and the model evidence, which allows comparing alternative signaling mechanisms. The BCM uses a coupled system of non-linear differential equations to describe the dynamics of Antigen Presenting Cells, Natural Killer and T Cells together with the interpheron (IFN)-c and tumor necrosis factor (TNF)-a levels in the media culture. Fast and complete mixing of the media is assumed. The prior distribution of the parameters that describe the dynamics of the immunological response was obtained from the literature and theoretical considerations Our BCM applies successively the Levenberg-Marquardt algorithm to find the maximum a posteriori likelihood (MAP); the Metropolis Markov Chain Monte Carlo method to approximate the posterior distribution of the parameters and Thermodynamic Integration to calculate the evidence of alternative hypothesis. Bayes factors provided decisive evidence favoring direct CD137 signaling on T cells. Moreover, the posterior distribution of the parameters that describe the CD137 signaling showed that the regulation of IFNc levels is based more on T cells survival than on direct induction. Furthermore, the mechanisms that account for the effect of CD137 signaling on TNF-a production were based on a decrease of TNF-a production by APC and, perhaps, on the increase in APC apoptosis. BCM proved to be a useful tool to gain insight on the mechanisms of CD137 signaling during human response against Mycobacterium tuberculosis.Fil: Darío A Fernåndez Do Porto. UNIV.DE BUENOS AIRES. FAC.DE CS.EXACTAS Y NATURALES. UNIV.DE BUENOS AIRES. FAC.DE CS.EXACTAS Y NATURALES. INST QUIM FISICA D/L/MATERIALES MED AMB Y ENERG.Fil: Jerónimo Auzmendi. UNIV.DE BUENOS AIRES. FAC.DE CS.EXACTAS Y NATURALES. INST QUIM FISICA D/L/MATERIALES MED AMB Y ENERG.Fil: Delfina Peña. UNIV.DE BUENOS AIRES. FAC.DE CS.EXACTAS Y NATURALES. CONSEJO NAC.DE INVEST.CIENTIF.Y TECNICAS. OFICINA DE COORDINACION ADMINISTRATIVA CIUDAD UNIVERSITARIA. INSTITUTO DE QUIMICA BIOLOGICA DE LA FACULTAD DE CS. EXACTAS Y NATURALES. UNIV.DE BUENOS AIRES. FAC.DE CS.EXACTAS Y NATURALES. DTO.DE QUIMICA BIOLOGICA.Fil: Veronica E Garcia. CONSEJO NAC.DE INVEST.CIENTIF.Y TECNICAS. OFICINA DE COORDINACION ADMINISTRATIVA CIUDAD UNIVERSITARIA. INSTITUTO DE QUIMICA BIOLOGICA DE LA FACULTAD DE CS. EXACTAS Y NATURALES.Fil: Luciano Moffatt. UNIV.DE BUENOS AIRES. FAC.DE CS.EXACTAS Y NATURALES. INST QUIM FISICA D/L/MATERIALES MED AMB Y ENERG

    Functional properties of linseed meal fractions: Application as nutraceutical ingredient

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    Brown linseed (Linum ustatissimum) is pressed to produce oil, and the remaining linseed meal is rich in protein and soluble dietary fiber. To utilize the derivatives of linseed meal as food ingredients or additives, linseed meal was fractionated by controlling pH on a pilot-plant scale. Chemical composition, functional properties and health-related bioactivities, such as angiotensin-converting enzyme (ACE) inhibition and antioxidant activities, of the fractions were then analyzed. The alkaline soluble protein had the highest content of secoisolariciresinol diglucoside (SDG) and showed good emulsification activity, comparable to that of whole egg. The acid-soluble fraction showed the highest viscosity. ACE inhibition, antioxidant activities, and bile acid binding activity were observed in the soluble dietary fiber fraction. There was no correlation between SDG content and bioactivities. These findings indicate that the acid-soluble fraction is useful as a food ingredient to increase viscosity, while the soluble dietary fiber fraction has health-related features

    Fructobacillus tropaeoli sp. nov., a fructophilic lactic acid bacterium isolated from a flower

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    A fructophilic lactic acid bacterium, designated strain F214-1T, was isolated from a flower of Tropaeolum majus in South Africa. Based on phylogenetic analysis of 16S rRNA gene sequences, the strain formed a subcluster with Fructobacillus ficulneus and Fructobacillus pseudoficulneus and, based on recA gene sequences, the strain formed a subcluster with F. ficulneus. DNA-DNA hybridization studies showed that strain F214-1T was phylogenetically distinct from its closest relatives. Acid was produced from the fermentation of D-glucose, D-fructose and D-mannitol only. D-Fructose was the preferred sole carbon and energy source and was fermented more rapidly than D-glucose. Growth of the strain on D-glucose under anaerobic conditions was very weak but external electron acceptors such as oxygen and pyruvate enhanced growth on D-glucose. Lactic acid and acetic acid were produced from D-glucose in equimolar amounts. Ethanol was produced at very low levels, despite the strain's obligately heterofermentative metabolism. Based on these data, strain F214-1T represents a novel species of fructophilic bacteria in the genus Fructobacillus, for which the name Fructobacillus tropaeoli sp. nov. is proposed. The type strain is F214-1T (=5JCM 16675T =DSM 23246T). © 2011 IUMS.Articl
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