Fucan is a term used to denominate a type of polysaccharide which contains substantial percentages of l-fucose and sulfate ester groups. We obtained five heterofucans from Sargassum filipendula by ...proteolytic digestion followed by sequential acetone precipitation. These heterofucans are composed mainly of fucose, glucose, glucuronic acid, galactose and sulfate. These fucans did not show anticoagulant activity in PT and aPTT tests. Their antioxidant activity was evaluated using the follow tests; total antioxidant capacity, scavenging hydroxyl and superoxide radicals, reducing power and ferrous ion Fe(II) chelating. All heterofucans displayed considerable activity, especially SF-1.0v which showed the most significant antioxidant potential with 90.7 ascorbic acid equivalents in a total antioxidant capacity test and similar activity when compared with vitamin C in a reducing power assay. The fucan antiproliferative activity was performed with HeLa, PC3 and HepG2 cells using MTT test. In all tested conditions the heterofucans exhibited a dose-dependent effect. The strongest inhibition was observed in HeLa cells, where SF-1.0 and SF-1.5 exhibited considerable activity with an IC50 value of 15.69 and 13.83 μM, respectively. These results clearly indicate the beneficial effect of S. filipendula polysaccharides as antiproliferative and antioxidant. Further purification steps and additional studies on structural features as well as in vivo experiments are needed to test the viability of their use as therapeutic agents.
Abstract
In this study, we look at recent developments in our understanding of the life cycle of the red spiny lobster Panulirus argus (Latreille, 1804) and examine the evidence for connectivity ...between geographical regions, especially the north-northeast Brazilian continental shelf and the Wider Caribbean. The study also covers aspects of reproduction, phyllosoma density, large-scale oceanic circulation, self-recruitment, settlement patterns, ecological behaviour, and the impact of the Amazon and Orinoco river discharge on recruitment. Our findings support the hypothesis that lobster larvae are transported by ocean currents and free eddies from Brazil to the Caribbean via the Lesser Antilles, outlining a south-to-north connectivity. In addition, we look into the probable existence of hybrids between sympatric lobster species, as evidenced by differences in colour patterns and morphology.
Leishmaniasis is one of the deadliest neglected tropical diseases affecting 12-15 million people worldwide, especially in middle- and low-income countries. Rapid and accurate diagnosis of the disease ...is important for its adequate management and treatment. Several techniques are available for the diagnosis of leishmaniasis. Among these, parasitological and immunological tests are most widely used. However, in most cases, the utilized diagnostic techniques are not good enough, showing cross-reactivity and reduced accuracy. In recent years, many new methods have been reported with potential for improved diagnosis. This review focuses on the diagnosis of
exploring the biosensors and nanotechnology-based options for their detection. New developments including the use of nanomaterials as fluorophores, fluorescence quenchers as reducing agents and as dendrimers for signal improvement and amplification, together with the use of aptamers to replace antibodies are described. Future research opportunities to overcome the current limitations on the available diagnostic approaches are also discussed.
•Helminths proteins, especially from Schistosoma mansoni, lead to reduction of symptoms of atopy and allergic diseases.•The S. mansoni proteins rSm200-3 and rSmKI-1 stimulating IL-10 production by ...human PBMC and when associated with B. tropicalis extract promotes the reduction of Th2 profile cytokines.•In a murine model, both proteins promote reduction of IL-5 and IL-4 levels in lung homogenates and of serum IgE. SmKI-1 was also able to decrease the levels of EPO in lung homogenates and in BAL.
The prevalence of allergic diseases in Brazil is one of the biggest in the world. Among these pathologies, we highlight asthma as one of the most importance. Asthma is characterized as a chronic inflammatory disease of airways, associated with hyperresponsiveness. Many environmental factors can trigger asthma symptoms, among them house dust mites can stimulate hypersensitivity type I reaction. The most common in house dust mite, in tropical countries, are Dermatophagoides pteronysinus and Blomia tropicalis. Several studies have shown that helminths, especially Schistosoma mansoni, lead to reduction of symptoms of atopy and allergic diseases. Therefore, the present study aims to evaluate the ability of recombinant S. mansoni proteins Sm200, and SmKI-1 to induce immunomodulation in vitro, using peripheral blood mononuclear cells (PBMCs) from atopic and non-atopic individuals, stimulated or not with B. tropicalis extract, and in vivo, in a murine model of allergy to the mite B. tropicalis. As results, we observed that the fragment called rSm200-3 and the protein rSmKI-1 stood out for their immunomodulatory potential, stimulating IL-10 production by human PBMCs in vitro. When these proteins were associated with B. tropicalis extract, it was observed the reduction of the production of the cytokine IL-5, with a statistically significant difference in non-atopic individual’s cells. In vivo, both proteins presented similar results, with a reduction of IL-5 and IL-4 levels in lung homogenates and of serum IgE. SmKI-1 was also able to decrease the levels of EPO in lung homogenates and in BAL. These results showed that both proteins were able to downmodulate Th2 cells on human PBMCs, and in a murine model of allergy. However, SmKI-1 also reduced significantly the levels of EPO in BAL and lungs showing that this protein may be a good candidate to be used as a possible replacement or in conjunction with pharmacotherapy in individuals with unregulated immune response in asthma.
Among non-communicable diseases, cardiovascular diseases are the most prevalent, accounting for approximately 17 million deaths per year. Despite conventional treatment, cardiac tissue engineering ...emerges as a potential alternative for the advancement and treatment of these patients, using biomaterials to replace or repair cardiac tissues. Among these materials, gelatin in its methacrylated form (GelMA) is a biodegradable and biocompatible polymer with adjustable biophysical properties. Furthermore, gelatin has the ability to replace and perform collagen-like functions for cell development in vitro. The interest in using GelMA hydrogels combined with nanomaterials is increasingly growing to promote the responsiveness to external stimuli and improve certain properties of these hydrogels by exploring the incorporation of nanomaterials into these hydrogels to serve as electrical signaling conductive elements. This review highlights the applications of electrically conductive nanomaterials associated with GelMA hydrogels for the development of structures for cardiac tissue engineering, by focusing on studies that report the combination of GelMA with nanomaterials, such as gold and carbon derivatives (carbon nanotubes and graphene), in addition to the possibility of applying these materials in 3D tissue engineering, developing new possibilities for cardiac studies.
The aim of this study was to identify candidate genes and genomic regions associated with ultrasound‐derived measurements of the rib‐eye area (REA), backfat thickness (BFT) and rumpfat thickness ...(RFT) in Nellore cattle. Data from 640 Nellore steers and young bulls with genotypes for 290 863 single nucleotide polymorphisms (SNPs) were used for genomewide association mapping. Significant SNP associations were explored to find possible candidate genes related to physiological processes. Several of the significant markers detected were mapped onto functional candidate genes including ARFGAP3, CLSTN2 and DPYD for REA; OSBPL3 and SUDS3 for BFT; and RARRES1 and VEPH1 for RFT. The physiological pathway related to lipid metabolism (CLSTN2, OSBPL3, RARRES1 and VEPH1) was identified. The significant markers within previously reported QTLs reinforce the importance of the genomic regions, and the other loci offer candidate genes that have not been related to carcass traits in previous investigations.
The residual hydrothermalism associated with submarine volcanoes, following an eruption event, plays an important role in the supply of CO2 to the ocean. The emitted CO2 increases the acidity of ...seawater. The submarine volcano of El Hierro, in its degasification stage, provided an excellent opportunity to study the effect of volcanic CO2 on the seawater carbonate system, the global carbon flux, and local ocean acidification. A detailed survey of the volcanic edifice was carried out using seven CTD-pH-ORP tow-yo studies, localizing the redox and acidic changes, which were used to obtain surface maps of anomalies. In order to investigate the temporal variability of the system, two CTD-pH-ORP yo-yo studies were conducted that included discrete sampling for carbonate system parameters. Meridional tow-yos were used to calculate the amount of volcanic CO2 added to the water column for each surveyed section. The inputs of CO2 along multiple sections combined with measurements of oceanic currents produced an estimated volcanic CO2 flux = 6.0 10(5) ± 1.1 10(5 )kg d(-1) which is ~0.1% of global volcanic CO2 flux. Finally, the CO2 emitted by El Hierro increases the acidity above the volcano by ~20%.
The effect of current density and bath temperature in the electroplating process on resistance to corrosion of Zn-Ni alloys was evaluated in this work. The electrolytic bath consisted of nickel ...sulfate, zinc sulfate, sodium sulfate, boric acid, and sodium citrate at pH 7.0. The current density was varied in the range 20–80 mA/cm2 and the bath temperature in the range 30–60 °C. Increasing, independently, the current density or the bath temperature increased the nickel content in the obtained alloy, which affected the alloy microstructure, with a predominant γ phase and cauliflower-like morphology. The nickel content in the alloys was in the range 20–42%wt. A synergistic effect between the current density and bath temperature was observed from a design of experiments and response surface models. The maximum resistance to corrosion occurred for the alloy containing 42%wt. nickel. This alloy was obtained at upper levels of current density and bath temperature, presenting a corrosion potential of −0.789 V and polarization resistance of 4136 Ω.cm2.
Adsorption of Cu(II) on
P. aureofaciens cells is diminished by the presence of abundant exopolysaccharides via screening of strongly-binding functional groups of the cell wall.
Adsorption of copper ...on exopolysaccharide (EPS)-rich and (EPS)-poor soil rhizospheric
Pseudomonas aureofaciens cells was studied as a function of pH and copper concentration at different exposure time in order to assess the effect of cell exopolysaccharides on parameters of adsorption equilibria. The surface properties of bacteria were investigated as a function of pH and ionic strength using potentiometric acid–base titration and electrophoresis that permitted the assessment of the excess surface proton concentration and zeta-potential of the cells, respectively. For adsorption experiments, wide range of Cu concentration was investigated (0.1–375
μM) in order to probe both weak and strong binding sites at the surface. Experimental results were successively fitted using a Linear Programming Model approach. The groups with p
K
a of 4.2–4.8 and from 5.2 to 7.2, tentatively assigned as carboxylates and phosphoryl respectively, are the most abundant at the surface and thus essentially contribute to the metal binding. The presence of exopolysaccharides on the surface decreases the amount of copper adsorbed on the bacterial cell wall apparently via screening the underlining functional groups of the cell wall. At the same time, dissolved EPS substances do not contribute to Cu binding in aqueous solution. Results of this study allow quantification of the role played by the surface EPS matrix as a protective barrier for metal adsorption on bacterial cell walls.
PDF
