Activation of the NLRP3 Inflammasome Increases the IL-1β Level and Decreases GLUT4 Translocation in Skeletal Muscle during Insulin Resistance

Low-grade chronic inflammation plays a pivotal role in the pathogenesis of insulin resistance (IR), and skeletal muscle has a central role in this condition. NLRP3 inflammasome activation pathways promote low-grade chronic inflammation in several tissues. However, a direct link between IR and NLRP3 inflammasome activation in skeletal muscle has not been reported. Here, we evaluated the NLRP3 inflammasome components and their role in GLUT4 translocation impairment in skeletal muscle during IR. Male C57BL/6J mice were fed with a normal control diet (NCD) or high-fat diet (HFD) for 8 weeks. The protein levels of NLRP3, ASC, caspase-1, gasdermin-D (GSDMD), and interleukin (IL)-1β were measured in both homogenized and isolated fibers from the flexor digitorum brevis (FDB) or soleus muscle. GLUT4 translocation was determined through GLUT4myc-eGFP electroporation of the FBD muscle. Our results, obtained using immunofluorescence, showed that adult skeletal muscle expresses the inflammasome components. In the FDB and soleus muscles, homogenates from HFD-fed mice, we found increased protein levels of NLRP3 and ASC, higher activation of caspase-1, and elevated IL-1β in its mature form, compared to NCD-fed mice. Moreover, GSDMD, a protein that mediates IL-1β secretion, was found to be increased in HFD-fed-mice muscles. Interestingly, MCC950, a specific pharmacological NLRP3 inflammasome inhibitor, promoted GLUT4 translocation in fibers isolated from the FDB muscle of NCD- and HFD-fed mice. In conclusion, we found increased NLRP3 inflammasome components in adult skeletal muscle of obese insulin-resistant animals, which might contribute to the low-grade chronic metabolic inflammation of skeletal muscle and IR development.     

Depletion of tylosin residues in feathers,muscle and liver from broiler chickens after completion of antimicrobial therapy

Tylosin is one of the most commonly used antimicrobial drugs from the macrolide family and in broiler chickens it is used specially for the treatment of infectious pathologies. The poultry industry produces several by-products, among which feathers account for up to 7% of a chicken’s live weight, thus they amount to a substantial mass across the whole industry. Feathers have been repurposed as an animal feed ingredient by making them feather meal. Therefore, the presence of high concentrations of residues from antimicrobial drugs in feathers might pose a risk to global public health, due to re-entry of these residues into the food chain. This work aimed to characterise the depletion behaviour of tylosin in feather samples, while considering its depletion in muscle and liver tissue samples as a reference point. To achieve this goal, we have implemented and validated an analytical methodology suitable for detecting and quantifying tylosin in these matrices. Sixty broiler chickens, raised under controlled conditions, received an oral dose of 32 mg kg^-1 of tylosin for 5 days. Tylosin was quantified in muscle, liver and feathers by liquid chromatography coupled with a photodiode array detector (HPLC-DAD). High concentrations of tylosin were detected in feather samples over the whole experimental period after completing both the therapy and the recommended withdrawal time (WDT). On the other hand, tylosin concentrations in muscle and liver tissue samples fell below the limit of detection of this method on the first sampling day. Our results indicate that the WDT for feather samples is 27 days, hence using feather meal for the formulation of animal diets or for other agricultural purposes could contaminate with antimicrobial residues either other livestock species or the environment. In consequence, we recommend monitoring this matrix when birds have been treated with tylosin, within the context of poultry farming.     

Co-located single display collaborative learning for early childhood education

The benefits of collaborative learning are well documented. However, most of the research has been done with children beyond the ages of early childhood. This could be due to the common and erroneous belief that young children have not developed the capacity to work collaboratively toward a given aim. In this paper we show how small group co-located collaborative learning on a single display computer improves oral language, logical-mathematical and social skills in pre-school children. Considering that early childhood teachers have a responsibility to provide a supportive environment, teacher mediation is essential in order to achieve collaborative learning. Thus, teachers were trained in the use of the technology and strategies for effective collaborative learning. The study was implemented in 10 kindergarten classrooms with 268 children between the ages of 5 and 6 years old. A group of 5 kindergarten classrooms with equivalent characteristics participated as a comparison group. During the four-month intervention, children worked on collaborative activities at least twice a week. A quasi-experimental approach was used to assess the implementation, including pre- and post-testing. The data showed differences in the learning of oral language, logical-mathematical and social skills, with the experimental group demonstrating significantly greater achievement.     

In vitro biotransformation of OA-group and PTX-group toxins in visceral and non-visceral tissues of Mytilus chilensis and Ameghinomya antiqua

ABSTRACT

Lipophilic marine toxins (LMTs) are made up of multiple groups of toxic analogues, which are characterised by different levels of cellular and toxic action. The most prevalent groups in the southern Pacific zone are: a) okadaic acid group (OA-group) which consists of okadaic acid (OA) and dinophysistoxin-1 (DTX-1); and, b) pectenotoxin-2 (PTX2) group which consists of pectenotoxin-2 (PTX-2). The main objective of our study was to examine in vitro biotransformation of OA-group and PTX-group in the tissues of two endemic species of bivalves from southern Chile; blue mussels (Mytilus chilensis) and clams (Ameghinomya antiqua). The biotransformation processes of both groups were only detected in the digestive glands of both species using LC-MS/MS. The most frequently detected analogues were acyl derivatives (≈2.0 ± 0.1 μg ml^?1) for OA-group and PTX-2SA (≈1.4 ± 0.1 μg ml^?1) for PTX-group, with a higher percentage of biotransformation for OA-group (p < .001). In addition, simultaneous incubations of the different analogues (OA/PTX-2; DTX-1/PTX-2 and OA/DTX-1/PTX-2) did not show any interaction between the biotransformation processes. These results show that the toxicological variability of endemic species leads to biotransformation of the profile of toxins, so that these new analogues may affect people’s health.     

Steady-state dissolution kinetics of aluminum-goethite in the presence of desferrioxamine-B and oxalate ligands

This paper reports steady-state dissolution rates of synthetic low-substitution Al-goethites (mol % Al < 10) at pH 5 in the presence of the trihydroxamate siderophore, desferrioxamine B (DFO-B), and the common biological ligand, oxalate. The siderophore-promoted Fe release rate increased both with the level of Al substitution and with DFO-B concentration up to about 100 microM, after which a plateau occurred, suggesting a saturation effect from DFO-B adsorption as a precursor to dissolution. At concentrations above 200 microM, oxalate also enhanced the Fe release rate, which however was not influenced by Al substitution. For Al-goethites with mol % Al < 4, the Fe release rate in the presence of 40 microM DFO-B together with varying concentrations of oxalate was typically greater than the corresponding sum of dissolution rates in the presence of the two ligands alone. This synergism may be the combined result of the ability of oxalate to adsorb strongly at the goethite surface, thus promoting Fe release, and of the high selectivity of DFO for Fe(III). Ferric oxalate complexes formed during dissolution will likely lose Fe3+ by ligand substitution with DFO-B, leading to the production of Fe(HDFO-B)+ and uncomplexed oxalate, the latter of which, in turn, could adsorb to the goethite surface again. For Al-goethites with mol % Al > 4, synergism was not apparent, which may signal the effect of a decreased surface density of Fe-OH sites associated with Al for Fe substitution. The oxalate-promoted release rates of Al did not scale with those of Fe, indicating incongruent dissolution. However, Al release rates in the presence of DFO-B did scale approximately with those of Fe but were not affected by the concentration of siderophore. These results are consistent with the presence of Al(OH)3 inclusions in Al-goethite.     

The role of gender,age and location in the values of work behind time use patterns in Santiago,Chile*

We apply a time assignment model system to estimate and analyse spatial differences in the values of work and leisure for segments of travellers who work in Santiago, Chile, a large, spatially segregated South American capital. The sample was obtained from the latest available Origin Destination Survey; it includes weekly time use and socio‐economic characteristics, which represent the differences across zones. Seventeen segments are defined according to gender, age, family structure and zone of residence. Positive values of the marginal utility of work are obtained for women and youngsters, and negative for men and elders. Women without children showed larger values than mothers. Results are explained in terms of income hierarchy and committed time.     

Synthesis of hectorite–TiO2 and kaolinite–TiO2 nanocomposites with photocatalytic activity for the degradation of model air pollutants

We studied the synthesis and photocatalytic activity of small-sized TiO₂ supported on hectorite and kaolinite. Deposition of TiO₂ on the clay mineral surface was conducted by using a sol–gel method with titanium isopropoxide as precursor. Anatase TiO₂ particles formation was achieved by hydrothermal treatment at 180 °C. Material characterization was conducted using XRD, SEM, XPS, ICP-OES, BET and porosimetry analysis. fficiency in synthesizing clay–TiO₂ composites depended strongly on the clay mineral structure. Incorporation of anatase in hectorite, an expandable clay mineral, was found to be very significant (> 36 wt.% Ti) and to be followed by important structural changes at the clay mineral surface. Instead, no major structural modifications of the clay were observed for kaolinite–TiO₂, as compared with the untreated material. Photocatalytic performance of clay–TiO₂ composites was evaluated with ATR-FTIR following the oxidation of adsorbed toluene and d-limonene, two model air pollutants. In either case, the photocatalytic removal efficiency of these hydrophobic substrates by the synthesized clay–TiO₂ composites was comparable to that observed using pure commercial TiO₂ (Degussa P25).     

Determination of the toxic variability of lipophilic biotoxins in marine bivalve and gastropod tissues treated with an industrial canning process

Contamination of shellfish with lipophilic marine biotoxins (LMB), pectenotoxins (PTXs), yessotoxins (YTXs) and okadaic acid (OA) toxin groups in southern Chile is a constant challenge for the development of miticulture considering the high incidence of toxic episodes that tend to occur. This research is focused on using methodologies for assessing the decrease in toxins of natural resources in Chile with high value, without altering the organoleptic properties of the shellfish. The species were processed through steaming (1 min at 121°C) and subsequent canning (5 min at 121°C). Changes in the profiles of toxins and total toxicity levels of LMB in endemic bivalves and gastropods were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The total reduction of toxicity (≈ 15%) was not related to the destruction of the toxin, but rather to the loss of LMB on removing the shells and packing media of canned products (***p < 0.001). Industrial processing of shellfish reduces LMB contents by up to 15% of the total initial contents, concomitant only with the interconversion of PTX-group toxins into PTX-2sa. In soft bottom-dwelling species with toxicities beyond the standard for safe human consumption (≥ 160 μg OA-eq kg^–1), toxicity can be reduced to safe levels through industrial preparation procedures.     

Glucose electro-fermentation with mixed cultures: A key role of the Clostridiaceae family

Electro-fermentation is a new type of bioprocess combining the concepts of fermentation and electro-microbiology to improve the conversion of organic substrates into valuable fermentation products. During electro-fermentation metabolic profiles could be redirected by the presence of polarized electrodes through changes in the microbial communities in the dark fermentation. This paper aims to investigate the influence of the bacterial community composition on glucose electro-fermentation in batch electro-systems. Our results showed that the initial microbial community significantly impacted the final microbial community and related metabolic patterns. During electro-fermentation, the H₂ yield was increased using anaerobic sludge but decreased using activated sludge as inocula. While using other inocula from similar origins, no differences between electro-fermentation and traditional fermentation were evidenced. The relative abundance of Clostridiaceae family members in the inoculum appeared to be a determining factor affecting the global performances. These findings provide new insights on electro-fermentation mecanisms occurring in mixed cultures.     

Modeling the release of antimicrobial agents (thymol and carvacrol) from two different encapsulation materials

Food Science and Biotechnology - The release of microencapsulated natural antimicrobial (AM) agents (thymol and carvacrol) from two encapsulating matrixes [maltodextrin (MD) and soy protein (SP)]...