271 research outputs found
Can agricultural cultivation methods influence the healthfulness of crops for foods
The aim of the current study was to investigate if there are any health effects of long-term consumption of organically grown crops using a rat model. Crops were retrieved over two years from along-term field trial at three different locations in Denmark, using three different cultivation systems(OA, organic based on livestock manure; OB, organic based on green manure; and C, conventional with mineral fertilizers and pesticides)with two field replicates. The cultivation system had an impact on the nutritional quality, affecting γ-tocopherol, some amino acids, and fatty acid composition. Additionally, the nutritional quality was affected by harvest year and location. However, harvest year and location rather than cultivation system affected the measured health biomarkers. In conclusion, the differences in dietary treatments composed of ingredients from different cultivation systems did not lead to significant differences in the measured health biomarkers, except for a significant difference in plasma IgGl evels
Hyaluronan Hydrogels: Rheology and Stability in Relation to the Type/Level of Biopolymer Chemical Modification
BDDE (1,4-butanediol-diglycidylether)-crosslinked hyaluronan (HA) hydrogels are widely used for dermo-aesthetic purposes. The rheology and stability of the gels under physiological conditions greatly affect their clinical indications and outcomes. To date, no studies investigating how these features are related to the chemistry of the polymeric network have been reported. Here, four available HA-BDDE hydrogels were studied to determine how and to what extent their rheology and stability with respect to enzymatic hydrolysis relate to the type and degree of HA structural modification.1 H-/13 C-NMR analyses were associated for the quantification of the “true” HA chemical derivatization level, discriminating between HA that was effectively crosslinked by BDDE, and branched HA with BDDE that was anchored on one side. The rheology was measured conventionally and during hydration in a physiological medium. Sensitivity to bovine testicular hyaluronidase was quantified. The correlation between NMR data and gel rheology/stability was evaluated. The study indicated that (1) the gels greatly differed in the amounts of branched, crosslinked, and overall modified HA, with most of the HA being branched; (2) unexpectedly, the conventionally measured rheological properties did not correlate with the chemical data; (3) the gels’ ranking in terms of rheology was greatly affected by hydration; (4) the rheology of the hydrated gels was quantitatively correlated with the amount of crosslinked HA, whereas the correlations with the total HA modification level and with the degree of branched HA were less significant; (5) increasing HA derivatization/crosslinking over 9/3 mol% did not enhance the stability with respect to hyaluronidases. These results broaden our knowledge of these gels and provide valuable information for improving their design and characterization
Role of mitogen-activated protein kinases in the iNOS production and cytokine secretion by Salmonella enterica serovar Typhimurium porins
The role of diet in the aetiopathogenesis of inflammatory bowel disease
Crohn’s disease and ulcerative colitis, collectively known as IBD, are chronic inflammatory disorders of the gastrointestinal tract. Although the aetiopathogenesis of IBD is largely unknown, it is widely thought that diet has a crucial role in the development and progression of IBD. Indeed, epidemiological and genetic association studies have identified a number of promising dietary and genetic risk factors for IBD. These preliminary studies have led to major interest in investigating the complex interaction between diet, host genetics, the gut microbiota and immune function in the pathogenesis of IBD. In this Review, we discuss the recent epidemiological, gene–environment interaction, microbiome and animal studies that have explored the relationship between diet and the risk of IBD. In addition, we highlight the limitations of these prior studies, in part by explaining their contradictory findings, and review future directions
Anthraquinone Rhein Exhibits Antibacterial Activity against Staphylococcus aureus
Staphylococcus aureus (S. aureus) represents an important pathogen of clinical relevance, causing a wide variety of symptoms. The broad distribution of multidrug-resistant strains necessarily demands new antibacterial agents for the treatment of S. aureus infections. The aim of this study was to assess the antibacterial activity of plant-derived compounds, pure 4,5″-dihydroxy-anthraquinone-2-carboxylic acid (Rhein), against standard and clinical isolated S. aureus strains. The hemolysis and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays were used to determine the cytotoxicity on human erythrocytes and bronchial epithelial cells after treatment with Rhein. The antibacterial effect was assessed via disk diffusion test, broth microdilution methods, time-killing assays and live–dead evaluation (50–0.39 µg/mL). Rhein effect on the hemolytic activity of α-toxin and catalase were estimated. Moreover, crystal violet (CV) assay evaluated its impact on biofilm biomass. The compound exhibited 50% cytotoxic concentration (CC50) and 50% hemolysis concentration (EC50) of 43.6 and >50 µg/mL, respectively. The minimum inhibitory concentration (MIC) of Rhein was 12.5 µg/mL for all tested strains, exerting bacteriostatic action. MIC and sub-MIC concentrations of Rhein significantly reduced hemolytic and catalase activities, impairing the major virulence factors of S. aureus strains. Rhein also reduced biofilm biomass in a dose-dependent manner, reaching rates of about 50% eradication at a dose of 50 µg/mL. These findings suggest that Rhein could represent a promising therapeutic option for the treatment of S. aureus infections
A Programmable look-up table-based interpolator with nonuniform sampling scheme
Interpolation is a useful technique for storage of complex functions on limited memory space: some few sampling values are stored on a memory bank, and the function values in between are calculated by interpolation. This paper presents a programmable Look-Up Table-based interpolator, which uses a reconfigurable nonuniform sampling scheme: the sampled points are not uniformly spaced. Their distribution can also be reconfigured to minimize the approximation error on specific portions of the interpolated function's domain. Switching from one set of configuration parameters to another set, selected on the fly from a variety of precomputed parameters, and using different sampling schemes allow for the interpolation of a plethora of functions, achieving memory saving and minimum approximation error. As a study case, the proposed interpolator was used as the core of a programmable noise generatoroutput signals drawn from different Probability Density Functions were produced for testing FPGA implementations of chaotic encryption algorithms. As a result of the proposed method, the interpolation of a specific transformation function on a Gaussian noise generator reduced the memory usage to 2.71% when compared to the traditional uniform sampling scheme method, while keeping the approximation error below a threshold equal to 0.000030518
Hijacking SARS-CoV-2/ACE2 Receptor Interaction by Natural and Semi-synthetic Steroidal Agents Acting on Functional Pockets on the Receptor Binding Domain
The coronavirus disease 2019 (COVID-19) is a respiratory tract infection caused by the severe acute respiratory syndrome coronavirus (SARS)-CoV-2. In light of the urgent need to identify novel approaches to be used in the emergency phase, we have embarked on an exploratory campaign aimed at repurposing natural substances and clinically available drugs as potential anti-SARS-CoV2-2 agents by targeting viral proteins. Here we report on a strategy based on the virtual screening of druggable pockets located in the central β-sheet core of the SARS-CoV-2 Spike's protein receptor binding domain (RBD). By combining an in silico approach and molecular in vitro testing we have been able to identify several triterpenoid/steroidal agents that inhibit interaction of the Spike RBD with the carboxypeptidase domain of the Angiotensin Converting Enzyme (ACE2). In detail, we provide evidence that potential binding sites exist in the RBD of the SARS CoV-2 Spike protein and that occupancy of these pockets reduces the ability of the RBD to bind to the ACE2 consensus in vitro. Naturally occurring and clinically available triterpenoids such as glycyrrhetinic and oleanolic acids, as well as primary and secondary bile acids and their amidated derivatives such as glyco-ursodeoxycholic acid and semi-synthetic derivatives such as obeticholic acid reduces the RBD/ACE2 binding. In aggregate, these results might help to define novel approaches to COVID-19 based on SARS-CoV-2 entry inhibitors
Lipid biomarkers in statin users with coronary artery disease annotated by coronary computed tomography angiography
Molecular markers are suggested to improve the diagnostic and prognostic accuracy in patients with coronary artery disease (CAD) beyond current clinical scores based on age, gender, symptoms and traditional risk factors. In this context, plasma lipids are emerging as predictors of both plaque composition and risk of future events. We aim to identify plasma lipid biomarkers associated to CAD indexes of stenosis severity, plaque lipid content and a comprensive score of CAD extent and its risk. We used a simple high performance liquid chromatography-tandem mass spectrometry method to identify 69 plasma lipids in 132 subjects referred to Coronary Computed Tomography Angiography (CCTA) for suspected CAD, all under statin treatment. Patients were stratified in groups using three different CCTA-based annotations: CTA-risk score, lipid plaque prevalence (LPP) ratio and the coronary artery disease-reporting and data system (CAD-RADS). We identified a common set of lipid biomarkers composed of 7 sphingomyelins and 3 phosphatidylethanolamines, which discriminates between high risk CAD patients and controls regardless of the CAD annotations used (CTA score, LPP ratio, or CAD-RADS). These results highlight the potential of circulating lipids as biomarkers of stenosis severity, non calcified plaque composition and overall plaque risk of events.Cardiolog
Self-assembled or mixed peptide amphiphile micelles from herpes simplex virus glycoproteins as potential immunomodulatory treatment
The use of micelle aggregates formed from peptide amphiphiles (PAs) as potential synthetic self-adjuvant vaccines to treat Herpes simplex virus (HSV) infection are reported here. The PAs were based on epitopes gB409-505 and gD301-309, selected from HSV envelope glycoprotein B (gB) and glycoprotein D (gD), that had their N-terminus modified with hydrophobic moieties containing two C18 hydrocarbon chains. Pure and mixed micelles of gB and/or gD peptide epitopes were easily prepared after starting with the synthesis of corresponding PAs by solid phase methods. Structural characterization of the aggregates confirmed that they were sufficiently stable and compatible with in vivo use: critical micelle concentration values around 4.0 · 10-7 mol · Kg-1; hydrodynamic radii (RH) between 50-80 nm, and a zeta potential (ζ) around -40 mV were found for all aggregates. The in vitro results indicate that both peptide epitopes and micelles, at 10 μM, triggered U937 and RAW 264.7 cells to release appreciable levels of cytokines. In particular, interleukin (IL)-23-, IL-6-, IL-8- or macrophage inflammatory protein (MIP)-2-, and tumor necrosis factor (TNF)-α-release increased considerably when cells were treated with the gB-micelles or gD-micelles compared with the production of the same cytokines when the stimulus was the single gB or gD peptid
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