215 research outputs found
Sourdough bacterial dynamics revealed by metagenomic analysis in Brazil.
This study dealt with the influence of the temperature on the bacterial dynamics of two spontaneously fermented wheat sourdoughs, propagated at 21 ± 1 °C (SD1) and 30 ± 1 °C (SD2), during nine backslopping steps (BS1 to BS9). Proteobacteria was the only phylum found in flour. Escherichia hermannii was predominant, followed by Kosakonia cowanii, besides species belonging to the genera Pantoea and Pseudomonas. After one step of propagation, Clostridium and Bacillus cereus group became predominant. Lactobacillus curvatus was found at low relative abundance. For the second backslopping step, Clostridium was flanked by L. curvatus and Lactobacillus farciminis. From BS4 (6th day) onward, lactic acid bacteria (LAB) became predominant. L. farciminis overcame L. curvatus and remained dominant until the end of propagations for both sourdoughs. At 21 °C, Bacillus, Clostridium, Pseudomonas, and Enterobacteriaceae were gradually inhibited. At the end of propagation, SD1 harbored only LAB. Otherwise, the temperature of 30 °C favored the persistence of atypical bacteria in SD2, as Pseudomonas and Enterobacteriaceae. Therefore, the temperature of 21 °C was more suitable for sourdough propagation in Brazil. This study enhanced the knowledge of temperature's influence on microbial assembly and contributed to the elucidation of sourdough microbial communities in Brazil
Reliability of nephrolithometric nomograms in patients treated with minimally invasive percutaneous nephrolithotomy: A precision study
Objectives: The study aimed to evaluate quality of nephrolithometric nomograms to predict stone-free rates (SFRs) and complication rates (CRs) in case of minimally invasive percutaneous nephrolithotomy (PNL). In the last decade, nomograms have been introduced to estimate the SFRs and CRs of PNL. However, no data are available regarding their reliability in case of utilization of miniaturized devices. Herein we present a prospective multicentric study to evaluate reliability of Guy's stone score (GSS), the stone size, tract length, obstruction, number of involved calyces, and essence of stone (S.T.O.N.E.) nephrolithometry score and Clinical Research Office of the Endourological Society (CROES) score in patients treated with minimally invasive PNL. Methods: We evaluated SFRs and CRs of 222 adult patients treated with miniaturized PNL. Patients were considered stone-free if no residual fragments of any size at post-operative unenhanced computed tomography scan. Patients demographics, SFRs, and CRs were reported and analysed. Performances of nomograms were evaluated with the area under the curve (AUC). Results: We included 222 patients, the AUCs of GSS, CROES score and S.T.O.N.E. nephrolithometry score were 0.69 (95% confidence interval [CI] 0.61–0.78), 0.64 (95% CI 0.56–0.73), and 0.62 (95% CI 0.52–0.71), respectively. Regarding SFRs, at multivariate binomial logistic regression, only the GSS had significance with an odds ratio (OR) of 0.53 (95% CI 0.31–0.95, p=0.04). We did not find significant correlation with complications, with only a trend for GSS. Conclusion: This is the first study evaluating nomograms in miniaturized PNL. They still show good reliability; however, our data showed lower performances compared to standard PNL. We emphasize the need of further studies to confirm this trend. A dedicated nomogram for minimally invasive PNL may be necessary
REGULATION OF PROSTAGLANDIN GENERATION IN CARRAGEENAN-INDUCED PLEURISY BY INDUCIBLE NITRIC OXIDE SYNTHASE IN KNOCKOUT MICE
In the present study, by comparing the responses in wild-type mice (iNOSWT) and mice lacking (iNOSKO) the inducible (or type 2) nitric oxide synthase (iNOS), we investigated the correlation between endogenous nitric oxide (NO) and prostaglandin (PG) generation in carrageenan-induced pleurisy. The inflammatory response in iNOSKO mice was significantly reduced in respect to iNOSWT animals, as demonstrated by the exudate volume (-63%) and numbers of infiltrating cells (-62%). The levels of NOx in the pleural exudate from carrageenan-treated mice were significantly (p < 0.01) decreased in iNOSKO mice (16 ± 7.6 nmoles/mice) compared to iNOSWT animals (133 ± 9 nmoles/mice). Similarly, the amounts of PGE2 in the pleural exudates of carrageenan-treated animals were significantly (p < 0.01) lower in iNOSKO compared to iNOSWT mice (120 ± 20 pg/mice vs. 308 ± 51 pg/mice). Also the amounts of 6-keto-PGF1α produced by lungs from carrageenan-treated iNOSKO mice (1.01 ± 0.10 ng/tissue mg) were significantly (p < 0.01) reduced compared to iNOSWT carrageenan-treated mice (2.1 ± 0.09 ng/tissue mg). In conclusion our results confirm, by the use of iNOSKO mice that in carrageenan-induced pleurisy NO positively modulates PG biosynthesis
A mechanism for the inhibition of DNA-PK-mediated DNA sensing by a virus
The innate immune system is critical in the response to infection by pathogens and it is activated by pattern recognition receptors (PRRs) binding to pathogen associated molecular patterns (PAMPs). During viral infection, the direct recognition of the viral nucleic acids, such as the genomes of DNA viruses, is very important for activation of innate immunity. Recently, DNA-dependent protein kinase (DNA-PK), a heterotrimeric complex consisting of the Ku70/Ku80 heterodimer and the catalytic subunit DNA-PKcs was identified as a cytoplasmic PRR for DNA that is important for the innate immune response to intracellular DNA and DNA virus infection. Here we show that vaccinia virus (VACV) has evolved to inhibit this function of DNA-PK by expression of a highly conserved protein called C16, which was known to contribute to virulence but by an unknown mechanism. Data presented show that C16 binds directly to the Ku heterodimer and thereby inhibits the innate immune response to DNA in fibroblasts, characterised by the decreased production of cytokines and chemokines. Mechanistically, C16 acts by blocking DNA-PK binding to DNA, which correlates with reduced DNA-PK-dependent DNA sensing. The C-terminal region of C16 is sufficient for binding Ku and this activity is conserved in the variola virus (VARV) orthologue of C16. In contrast, deletion of 5 amino acids in this domain is enough to knockout this function from the attenuated vaccine strain modified vaccinia virus Ankara (MVA). In vivo a VACV mutant lacking C16 induced higher levels of cytokines and chemokines early after infection compared to control viruses, confirming the role of this virulence factor in attenuating the innate immune response. Overall this study describes the inhibition of DNA-PK-dependent DNA sensing by a poxvirus protein, adding to the evidence that DNA-PK is a critical component of innate immunity to DNA viruses
The Soluble Recombinant Neisseria meningitidis Adhesin NadAΔ351–405 Stimulates Human Monocytes by Binding to Extracellular Hsp90
The adhesin NadA favors cell adhesion/invasion by hypervirulent Neisseria meningitidis B (MenB). Its recombinant form NadAΔ351–405, devoid of the outer membrane domain, is an immunogenic candidate for an anti-MenB vaccine able to stimulate monocytes, macrophages and dendritic cells. In this study we investigated the molecular mechanism of NadAΔ351–405 cellular effects in monocytes. We show that NadAΔ351–405 (against which we obtained polyclonal antibodies in rabbits), binds to hsp90, but not to other extracellular homologous heat shock proteins grp94 and hsp70, in vitro and on the surface of monocytes, in a temperature dependent way. Pre-incubation of monocytes with the MenB soluble adhesin interfered with the binding of anti-hsp90 and anti-hsp70 antibodies to hsp90 and hsp70 at 37°C, a condition in which specific cell-binding occurs, but not at 0°C, a condition in which specific cell-binding is very diminished. Conversely, pre-incubation of monocytes with anti-hsp90 and anti-hsp70 antibodies did not affected NadAΔ351–405 cell binding in any temperature condition, indicating that it associates to another receptor on their plasma membrane and then laterally diffuses to encounter hsp90. Consistently, polymixin B interfered with NadAΔ351–405 /hsp90 association, abrogated the decrease of anti-hsp90 antibodies binding to the cell surface due to NadAΔ351–405 and inhibited adhesin-induced cytokine/chemokine secretion without affecting monocyte-adhesin binding. Co-stimulation of monocytes with anti-hsp90 antibodies and NadAΔ351–405 determined a stronger but polymixin B insensitive cell activation. This indicated that the formation of a recombinant NadA/hsp90/hsp70 complex, although essential for full monocyte stimulation, can be replaced by anti-hsp90 antibody/hsp90 binding. Finally, the activation of monocytes by NadAΔ351–405 alone or in the presence of anti-hsp90 antibodies were both inhibited by neutralizing anti-TLR4 antibodies, but not by anti-TLR2 antibodies. We propose that hsp90-dependent recruitment into an hsp90/hsp70/TLR4 transducing signal complex is necessary for the immune-stimulating activity of NadAΔ351–405 anti-MenB vaccine candidate
EEG for good outcome prediction after cardiac arrest: a multicentre cohort study.
AIM
Assess the prognostic ability of a non-highly malignant and reactive EEG to predict good outcome after cardiac arrest (CA).
METHODS
Prospective observational multicentre substudy of the "Targeted Hypothermia versus Targeted Normothermia after Out-of-hospital Cardiac Arrest Trial", also known as the TTM2-trial. Presence or absence of highly malignant EEG patterns and EEG reactivity to external stimuli were prospectively assessed and reported by the trial sites. Highly malignant patterns were defined as burst-suppression or suppression with or without superimposed periodic discharges. Multimodal prognostication was performed 96 hours after CA. Good outcome at 6 months was defined as a modified Rankin Scale score of 0-3.
RESULTS
873 comatose patients at 59 sites had an EEG assessment during the hospital stay. Of these, 283 (32%) had good outcome. EEG was recorded at a median of 69 hours (IQR 47-91) after CA. Absence of highly malignant EEG patterns was seen in 543 patients of whom 255 (29% of the cohort) had preserved EEG reactivity. A non-highly malignant and reactive EEG had 56% (CI 50-61) sensitivity and 83% (CI 80-86) specificity to predict good outcome. Presence of EEG reactivity contributed (p<0.001) to the specificity of EEG to predict good outcome compared to only assessing background pattern without taking reactivity into account.
CONCLUSION
Nearly one-third of comatose patients resuscitated after CA had a non-highly malignant and reactive EEG that was associated with a good long-term outcome. Reactivity testing should be routinely performed since preserved EEG reactivity contributed to prognostic performance
Effects of Hypericum Perforatum, in a rodent model of periodontitis
<p>Abstract</p> <p>Background</p> <p><it>Hypericum perforatum </it>is a medicinal plant species containing many polyphenolic compounds, namely flavonoids and phenolic acids. In this study we evaluate the effect of <it>Hypericum perforatum </it>in animal model of periodontitis.</p> <p>Methods</p> <p>Periodontitis was induced in adult male Sprague-Dawley rats by placing a nylon thread ligature around the lower 1st molars. Hypericum perforatum was administered at the dose of 2 mg/kg os, daily for eight days. At day 8, the gingivomucosal tissue encircling the mandibular first molar was removed.</p> <p>Results</p> <p>Periodontitis in rats resulted in an inflammatory process characterized by edema, neutrophil infiltration and cytokine production that was followed by the recruitment of other inflammatory cells, production of a range of inflammatory mediators such as NF-κB and iNOS expression, the nitration of tyrosine residues and activation of the nuclear enzyme poly (ADP-ribose) polymerase; apoptosis and the degree of gingivomucosal tissues injury. We report here that Hypericum perforatum exerts potent anti-inflammatory effects significantly reducing all of the parameters of inflammation as described above.</p> <p>Conclusions</p> <p>Taken together, our results clearly demonstrate that treatment with Hypericum reduces the development of inflammation and tissue injury, events associated with periodontitis.</p
Percepções sobre a discriminação homofóbica entre concluintes do ensino médio no Brasil entre 2004 e 2008
A discriminação homofóbica no contexto escolar é um problema grave em vários níveis de ensino, e está associada negativamente à percepção dos estudantes sobre o ambiente escolar. O presente estudo utiliza dados de 6.414.302 estudantes com idade entre 16 e 25 anos disponíveis no questionário sócioeconômico do Exame Nacional do Ensino Médio entre 2004 e 2008. São apresentados dados sobre a incidência de três fatores associados à homofobia entre concluintes do ensino médio: (1) sofrer discriminação homofóbica, (2) presenciar discriminação homofóbica e (3) admitir homofobia. A análise da associação entre a homofobia e a percepção dos estudantes sobre sua educação no ensino médio revela que os estudantes que não relatam ter sido alvos da discriminação homofóbica avaliam sua experiência escolar de forma mais positiva que seus pares que sofreram discriminação
Identification of Conserved and HLA Promiscuous DENV3 T-Cell Epitopes
Anti-dengue T-cell responses have been implicated in both protection and immunopathology. However, most of the T-cell studies for dengue include few epitopes, with limited knowledge of their inter-serotype variation and the breadth of their human leukocyte antigen (HLA) affinity. In order to expand our knowledge of HLA-restricted dengue epitopes, we screened T-cell responses against 477 overlapping peptides derived from structural and non-structural proteins of the dengue virus serotype 3 (DENV3) by use of HLA class I and II transgenic mice (TgM): A2, A24, B7, DR2, DR3 and DR4. TgM were inoculated with peptides pools and the T-cell immunogenic peptides were identified by ELISPOT. Nine HLA class I and 97 HLA class II novel DENV3 epitopes were identified based on immunogenicity in TgM and their HLA affinity was further confirmed by binding assays analysis. A subset of these epitopes activated memory T-cells from DENV3 immune volunteers and was also capable of priming naïve T-cells, ex vivo, from dengue IgG negative individuals. Analysis of inter- and intra-serotype variation of such an epitope (A02-restricted) allowed us to identify altered peptide ligands not only in DENV3 but also in other DENV serotypes. These studies also characterized the HLA promiscuity of 23 HLA class II epitopes bearing highly conserved sequences, six of which could bind to more than 10 different HLA molecules representing a large percentage of the global population. These epitope data are invaluable to investigate the role of T-cells in dengue immunity/pathogenesis and vaccine design. © 2013 Nascimento et al
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