Administration of β-glucans through various routes, including immersion, dietary inclusion, or injection, have been found to stimulate various facets of immune responses, such as resistance to ...infections and resistance to environmental stress. β-Glucans used as an immunomodulatory food supplement have been found beneficial in eliciting immunity in commercial aquaculture. Despite extensive research involving more than 3000 published studies, knowledge of the receptors involved in recognition of β-glucans, their downstream signaling, and overall mechanisms of action is still lacking. The aim of this review is to summarize and discuss what is currently known about of the use of β-glucans in fish.
An outbreak of coronavirus disease began in a large penitentiary complex in Brazil on April 1, 2020. By June 12, there were 1,057 confirmed cases among inmates and staff. Nine patients were ...hospitalized, and 3 died. Mean serial interval was ≈2.5 days; reproduction number range was 1.0-2.3.
This review explores the advances in the synthesis of ceria materials with specific morphologies or porous macro- and microstructures for the solar-driven production of carbon monoxide (CO) from ...carbon dioxide (CO
2
). As the demand for renewable energy and fuels continues to grow, there is a great deal of interest in solar thermochemical fuel production (STFP), with the use of concentrated solar light to power the splitting of carbon dioxide. This can be achieved in a two-step cycle, involving the reduction of CeO
2
at high temperatures, followed by oxidation at lower temperatures with CO
2
, splitting it to produce CO, driven by concentrated solar radiation obtained with concentrating solar technologies (CST) to provide the high reaction temperatures of typically up to 1,500°C. Since cerium oxide was first explored as a solar-driven redox material in 2006, and to specifically split CO
2
in 2010, there has been an increasing interest in this material. The solar-to-fuel conversion efficiency is influenced by the material composition itself, but also by the material morphology that mostly determines the available surface area for solid/gas reactions (the material oxidation mechanism is mainly governed by surface reaction). The diffusion length and specific surface area affect, respectively, the reduction and oxidation steps. They both depend on the reactive material morphology that also substantially affects the reaction kinetics and heat and mass transport in the material. Accordingly, the main relevant options for materials shaping are summarized. We explore the effects of microstructure and porosity, and the exploitation of designed structures such as fibers, 3-DOM (three-dimensionally ordered macroporous) materials, reticulated and replicated foams, and the new area of biomimetic/biomorphous porous ceria redox materials produced from natural and sustainable templates such as wood or cork, also known as ecoceramics.
We herein demonstrate the outstanding protein-repelling characteristic of star-like micelles and polymersomes manufactured from amphiphilic block copolymers made by poly(butylene oxide) (PBO) ...hydrophobic segments and polyglycidol (PGL) hydrophilic outer shells. Although positively charged proteins (herein modeled by lysozyme) may adsorb onto the surface of micelles and polymersomes where the assemblies are stabilized by short PGL chains (degree of polymerization smaller than 15), the protein adsorption vanishes when the degree of polymerization of the hydrophilic segment (PGL) is higher than ∼20, regardless the morphology. This has been probed by using three different model proteins which are remarkably different concerning molecular weight, size, and zeta potential (bovine serum albumin (BSA), lysozyme, and immunoglobulin G (IgG)). Indeed, the adsorption of the most abundant plasma protein (herein modeled as BSA) is circumvented even by using very short PGL shells due to the highly negative zeta potential of the produced assemblies which presumably promote protein-nanoparticle electrostatic repulsion. The negative zeta potential, on the other hand, enables lysozyme adsorption, and the phenomenon is governed by electrostatic forces as evidenced by isothermal titration calorimetry. Nevertheless, the protein coating can be circumvented by slightly increasing the degree of polymerization of the hydrophilic segment. Notably, the PGL length required to circumvent protein fouling is significantly smaller than the one required for PEO. This feature and the safety concerns regarding the synthetic procedures on the preparation of poly(ethylene oxide)-based amphiphilic copolymers might make polyglycidol a promising alternative toward the production of nonfouling spherical particles.
We sought to evaluate whether procalcitonin was superior to C-reactive protein in guiding antibiotic therapy in intensive care patients with sepsis.
Randomized open clinical trial.
Two university ...hospitals in Brazil.
Patients with severe sepsis or septic shock.
Patients were randomized in two groups: the procalcitonin group and the C-reactive protein group. Antibiotic therapy was discontinued following a protocol based on serum levels of these markers, according to the allocation group. The procalcitonin group was considered superior if the duration of antibiotic therapy was at least 25% shorter than in the C-reactive protein group. For both groups, at least seven full-days of antibiotic therapy were ensured in patients with Sequential Organ Failure Assessment greater than 10 and/or bacteremia at inclusion, and patients with evident resolution of the infectious process had antibiotics stopped after 7 days, despite biomarkers levels.
Ninety-four patients were randomized: 49 patients to the procalcitonin group and 45 patients to the C-reactive protein group. The mean age was 59.8 (SD, 16.8) years. The median duration of antibiotic therapy for the first episode of infection was 7.0 (Q1-Q3, 6.0-8.5) days in the procalcitonin group and 6.0 (Q1-Q3, 5.0-7.0) days in the C-reactive protein group (p=0.13), with a hazard ratio of 1.206 (95% CI, 0.774-1.3; p=0.13). Overall, protocol overruling occurred in only 13 (13.8%) patients. Twenty-one patients died in each group (p=0.836).
C-reactive protein was as useful as procalcitonin in reducing antibiotic use in a predominantly medical population of septic patients, causing no apparent harm.
Dengue is the most frequent hemorrhagic viral disease and re-emergent infection in the world. Although thrombocytopenia is characteristically observed in mild and severe forms of dengue, the role of ...platelet activation in dengue pathogenesis has not been fully elucidated. We hypothesize that platelets have major roles in inflammatory amplification and increased vascular permeability during severe forms of dengue. Here we investigate interleukin (IL)-1β synthesis, processing, and secretion in platelets during dengue virus (DV) infection and potential contribution of these events to endothelial permeability during infection. We observed increased expression of IL-1β in platelets and platelet-derived microparticles from patients with dengue or after platelet exposure to DV in vitro. We demonstrated that DV infection leads to assembly of nucleotide-binding domain leucine rich repeat containing protein (NLRP3) inflammasomes, activation of caspase-1, and caspase-1–dependent IL-1β secretion. Our findings also indicate that platelet-derived IL-1β is chiefly released in microparticles through mechanisms dependent on mitochondrial reactive oxygen species–triggered NLRP3 inflammasomes. Inflammasome activation and platelet shedding of IL-1β–rich microparticles correlated with signs of increased vascular permeability. Moreover, microparticles from DV-stimulated platelets induced enhanced permeability in vitro in an IL-1–dependent manner. Our findings provide new evidence that platelets contribute to increased vascular permeability in DV infection by inflammasome-dependent release of IL-1β.
•Dengue infection triggers functional inflammasome assembly in platelets.•Platelets may contribute to increased vascular permeability in dengue virus infection by synthesis and release of IL-1β.
BACKGROUND: Botanists, ecologists and evolutionary biologists are familiar with the astonishing species richness and endemism of the fynbos of the Cape Floristic Region and the ancient and unique ...flora of the kwongkan of south-western Australia. These regions represent old climatically-buffered infertile landscapes (OCBILs) that are the basis of a general hypothesis to explain their richness and endemism. However, few ecologists are familiar with the campo rupestre of central and eastern Brazil, an extremely old mountaintop ecosystem that is both a museum of ancient lineages and a cradle of continuing diversification of endemic lineages. SCOPE: Diversification of some lineages of campo rupestre pre-dates diversification of lowland cerrado, suggesting it may be the most ancient open vegetation in eastern South America. This vegetation comprises more than 5000 plant species, nearly 15 % of Brazil’s plant diversity, in an area corresponding to 0.78 % of its surface. Reviewing empirical data, we scrutinise five predictions of the OCBIL theory, and show that campo rupestre is fully comparable to and remarkably convergent with both fynbos and kwongkan, and fulfills the criteria for a classic OCBIL. CONCLUSIONS: The increasing threats to campo rupestre are compromising ecosystem services and we argue for the implementation of more effective conservation and restoration strategies.
This study sought to elucidate the primary ATP-dependent mechanisms involved in clearing cytosolic Ca2+ in neurons and determine the predominant ATP-generating pathway—glycolysis or tricarboxylic ...acid cycle/oxidative phosphorylation (TCA/OxPhos)—associated with these mechanisms in hippocampal pyramidal neurons.
Our investigation involved evaluating basal Ca2+ levels and analyzing the kinetic characteristics of evoked neuronal Ca2+ transients after selectively combined the inhibition/blockade of key ATP-dependent mechanisms with the suppression of either TCA/OxPhos or glycolytic ATP sources.
Our findings unveiled that the plasma membrane Ca2+ ATPase (PMCA) serves as the principal ATP-dependent mechanism for clearance cytosolic Ca2+ in hippocampal pyramidal neurons, both during rest and neuronal activity. Remarkably, during cellular activity, PMCA relies on ATP derived from glycolysis, challenging the traditional notion of neuronal reliance on TCA/OxPhos for ATP. Other mechanisms for Ca2+ clearance in pyramidal neurons, such as SERCA and NCX, appear to be dependent on TCA/OxPhos. Interestingly, at rest, the ATP required to fuel PMCA and SERCA, the two main mechanisms to keep resting Ca2+, seems to originate from a source other than glycolysis or the TCA/OxPhos.
These findings underscore the vital role of glycolysis in bolstering PMCA neuronal function to uphold Ca2+ homeostasis. Moreover, they elucidate the varying dependencies of cytoplasmic Ca2+ clearance mechanisms on distinct energy sources for their operation.
•PMCA is the main mechanism for Ca2+ clearance in hippocampal pyramidal neurons.•Glycolysis is the main source of ATP to supply the PMCA for cytoplasmic Ca2+ clearance.•Oxidative phosphorylation serves as an energy source for Ca2+-ATPases, except PMCA.
Dengue is the most prevalent human arbovirus disease worldwide. Dengue virus (DENV) infection causes syndromes varying from self-limiting febrile illness to severe dengue. Although dengue ...pathophysiology is not completely understood, it is widely accepted that increased inflammation plays important roles in dengue pathogenesis. Platelets are blood cells classically known as effectors of hemostasis which have been increasingly recognized to have major immune and inflammatory activities. Nevertheless, the phenotype and effector functions of platelets in dengue pathogenesis are not completely understood. Here we used quantitative proteomics to investigate the protein content of platelets in clinical samples from patients with dengue compared to platelets from healthy donors. Our assays revealed a set of 252 differentially abundant proteins. In silico analyses associated these proteins with key molecular events including platelet activation and inflammatory responses, and with events not previously attributed to platelets during dengue infection including antigen processing and presentation, proteasome activity, and expression of histones. From these results, we conducted functional assays using samples from a larger cohort of patients and demonstrated evidence for platelet activation indicated by P-selectin (CD62P) translocation and secretion of granule-stored chemokines by platelets. In addition, we found evidence that DENV infection triggers HLA class I synthesis and surface expression by a mechanism depending on functional proteasome activity. Furthermore, we demonstrate that cell-free histone H2A released during dengue infection binds to platelets, increasing platelet activation. These findings are consistent with functional importance of HLA class I, proteasome subunits, and histones that we found exclusively in proteome analysis of platelets in samples from dengue patients. Our study provides the first in-depth characterization of the platelet proteome in dengue, and sheds light on new mechanisms of platelet activation and platelet-mediated immune and inflammatory responses.
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