The labile lipid fraction of meat: from perceived disease and waste to health and opportunity

The fatty acid composition of beef and pork has been stigmatized due to their relationships with several diseases from cardiovascular disease to cancer. Meat lipids are, however, one of the few components of meat that can be modified in content and composition, and can present opportunities for value added production and health promotion. Until regulations and policies are in place to define requirements for fatty acid enrichment, however, the process remains relatively academic. Once practical goals are in place for fatty acid enrichment in meat, both theory and practice need to converge for successful production of fatty acid enriched meat. The present review covers aspects of policy in Canada, and requirements for research networks to respond to theoretical and practical challenges associated with production of fatty acid enriched meat. Finally, needs for education and marketing are outlined which must be in place to truly realize a transition of meat lipids from perceived disease and waste to health and opportunity.     

Revision of ochratoxin a production capacity by the main species of Aspergillus section Circumdati. Aspergillus steynii revealed as the main risk of OTA contamination

Ochratoxin A (OTA) is a highly toxigenic mycotoxin commonly present in a number of diverse agroproducts. Aspergillus Section Circumdati includes some of the most important OTA-producing species: Aspergillus ochraceus, Aspergillus elegans and the recently described Aspergillus steynii and Aspergillus westerdijkiae. In this work, OTA production by several strains of these four species from diverse origins and food matrices was examined. Identification of all the strains was carried out by specific PCR assays. The strains were cultivated in CYA solid medium and OTA was measured by HLPC. This study demonstrated for the first time the high capacity of A. steynii strains to produce OTA at higher levels than A. westerdijkiae,A. ochraceus and A. elegans strains showed low levels or no production at all. In conclusion, the results of this study suggest that the occurrence of A. steynii and A. westerdijkiae might represent the major potential risk for OTA contamination due to their high production and the diversity of commodities that these species may contaminate.     

Breast density classification to reduce false positives in CADe systems

This paper describes a novel weighted voting tree classification scheme for breast density classification. Breast parenchymal density is an important risk factor in breast cancer. Moreover, it is known that mammogram interpretation is more difficult when dense tissue is involved. Therefore, automated breast density classification may aid in breast lesion detection and analysis. Several classification methods have been compared and a novel hierarchical classification procedure of combined classifiers with linear discriminant analysis (LDA) is proposed as the best solution to classify the mammograms into the four BIRADS tissue classes. The classification scheme is based on 298 texture features. Statistical analysis to test the normality and homoscedasticity of the data was carried out for feature selection. Thus, only features that are influenced by the tissue type were considered. The novel classification techniques have been incorporated into a CADe system to drive the detection algorithms and tested with 1459 images. The results obtained on the 322 screen-film mammograms (SFM) of the mini-MIAS dataset show that 99.75% of samples were correctly classified. On the 1137 full-field digital mammograms (FFDM) dataset results show 91.58% agreement. The results of the lesion detection algorithms were obtained from modules integrated within the CADe system developed by the authors and show that using breast tissue classification prior to lesion detection leads to an improvement of the detection results. The tools enhance the detectability of lesions and they are able to distinguish their local attenuation without local tissue density constraints.     

Cytocompatibility and Suitability of Protein-Based Biomaterials as Potential Candidates for Corneal Tissue Engineering

The vision impairments suffered by millions of people worldwide and the shortage of corneal donors show the need of substitutes that mimic native tissue to promote cell growth and subsequent tissue regeneration. The current study focused on the in vitro assessment of protein-based biomaterials that could be a potential source for corneal scaffolds. Collagen, soy protein isolate (SPI), and gelatin films cross-linked with lactose or citric acid were prepared and physicochemical, transmittance, and degradation measurements were carried out. In vitro cytotoxicity, cell adhesion, and migration studies were performed with human corneal epithelial (HCE) cells and 3T3 fibroblasts for the films’ cytocompatibility assessment. Transmittance values met the cornea’s needs, and the degradation profile revealed a progressive biomaterials’ decomposition in enzymatic and hydrolytic assays. Cell viability at 72 h was above 70% when exposed to SPI and gelatin films. Live/dead assays and scanning electron microscopy (SEM) analysis demonstrated the adhesion of both cell types to the films, with a similar arrangement to that observed in controls. Besides, both cell lines were able to proliferate and migrate over the films. Without ruling out any material, the appropriate optical and biological properties shown by lactose-crosslinked gelatin film highlight its potential for corneal bioengineering.     

Selective Inhibition of an Apicoplastic Aminoacyl‐tRNA Synthetase from Plasmodium falciparum

The resistance of malaria parasites to available drugs continues to grow, and this makes the need for new antimalarial therapies pressing. Aminoacyl‐tRNA synthetases (ARSs) are essential enzymes and well‐established antibacterial targets and so constitute a promising set of targets for the development of new antimalarials. Despite their potential as drug targets, apicoplastic ARSs remain unexplored. We have characterized the lysylation system of Plasmodium falciparum, and designed, synthesized, and tested a set of inhibitors based on the structure of the natural substrate intermediate: lysyl‐adenylate. Here we demonstrate that selective inhibition of apicoplastic ARSs is feasible and describe new compounds that that specifically inhibit Plasmodium apicoplastic lysyl‐tRNA synthetase and show antimalarial activities in the micromolar range.     

Geochemical characterization of solid residues, bitumen and expelled oil based on steam pyrolysis experiments from Irati oil shale, Brazil: A preliminary study

Steam pyrolysis experiments were performed on immature samples from the Irati oil shale, Paraná Basin, Brazil, using a maximum temperature of 350 °C with up to 98 h exposure time at that temperature. The objectives were to study geochemical and petrographical changes in the source material during stepwise increase in maturity, in steam conditions, comparing the properties of expelled oil with the bitumen retained in the solid residue after experimentation.Petrographical and geochemical parameters such as vitrinite reflectance and T_max, indicated an increase in maturity related to the exposure time of the organic matter to the maximum temperature. However, biomarker ratios such as 22S/(22S + 22R) C₃₁ and C₃₂ homohopanes, 20S/(20S + 20R) and αββ/(αββ + ααα) C₂₉ sterane, which are considered to be indicators of organic matter maturity levels, did not reach their equilibrium values. Some biomarkers frequently used as indicators of specific sources and/or paleoenvironments of deposition such as hopane/sterane ratio, and the concentrations of C₂₇ and C₂₉ steranes showed significant variations related to the stage of maturity. Based on the evaluation of Rock-Eval parameters, the transformation ratios in steam pyrolysis conditions reached levels higher than 80% in samples having 9 and more hours of exposure time to maximum temperature. Bitumen was found to be enriched in components of heavier molecular weight (resins and asphaltenes), whereas the expelled oils contained higher quantities of aliphatic and aromatic components. At relatively low maturity levels the n-alkane distribution of expelled oils indicate a somewhat higher maturity level when compared to the n-alkane distribution of the bitumen retained in the source rock, whereas at higher maturity levels the n-alkane distribution for the expelled oil and for the bitumen is very similar.     

Co-Incubation with PPARβ/δ Agonists and Antagonists Modeled Using Computational Chemistry: Effect on LPS Induced Inflammatory Markers in Pulmonary Artery

Peroxisome proliferator activated receptor beta/delta (PPARβ/δ) is a nuclear receptor ubiquitously expressed in cells, whose signaling controls inflammation. There are large discrepancies in understanding the complex role of PPARβ/δ in disease, having both anti- and pro-effects on inflammation. After ligand activation, PPARβ/δ regulates genes by two different mechanisms; induction and transrepression, the effects of which are difficult to differentiate directly. We studied the PPARβ/δ-regulation of lipopolysaccharide (LPS) induced inflammation (indicated by release of nitrite and IL-6) of rat pulmonary artery, using different combinations of agonists (GW0742 or L−165402) and antagonists (GSK3787 or GSK0660). LPS induced release of NO and IL-6 is not significantly reduced by incubation with PPARβ/δ ligands (either agonist or antagonist), however, co-incubation with an agonist and antagonist significantly reduces LPS-induced nitrite production and Nos2 mRNA expression. In contrast, incubation with LPS and PPARβ/δ agonists leads to a significant increase in Pdk−4 and Angptl−4 mRNA expression, which is significantly decreased in the presence of PPARβ/δ antagonists. Docking using computational chemistry methods indicates that PPARβ/δ agonists form polar bonds with His287, His413 and Tyr437, while antagonists are more promiscuous about which amino acids they bind to, although they are very prone to bind Thr252 and Asn307. Dual binding in the PPARβ/δ binding pocket indicates the ligands retain similar binding energies, which suggests that co-incubation with both agonist and antagonist does not prevent the specific binding of each other to the large PPARβ/δ binding pocket. To our knowledge, this is the first time that the possibility of binding two ligands simultaneously into the PPARβ/δ binding pocket has been explored. Agonist binding followed by antagonist simultaneously switches the PPARβ/δ mode of action from induction to transrepression, which is linked with an increase in Nos2 mRNA expression and nitrite production.     

Evaluation of the migration of chemicals from baby bottles under standardised and duration testing conditions

After the prohibition of bisphenol-A-containing polycarbonate baby bottles in the European Union (EU), alternative materials, such as polypropylene, polyethersulphone, Tritan? copolyester, etc., have appeared on the market. Based on an initial screening and in vitro toxicity assessment, the most toxic migrating compounds were selected to be monitored and quantified using validated GC- and LC-QqQ-MS methods. The effect of several ‘real-life-use conditions’, such as microwave, sterilisation and dishwasher, on the migration of different contaminants was evaluated by means of duration tests. These results were compared with a reference treatment (filling five times with pre-heated simulant at 40°C) and with the legal EU ‘repetitive-use conditions’ (three migrations, 2 h at 70°C). Analysis of the third migration step of the EU repetitive-use conditions (which has to comply with the EU legislative migration limits) showed that several non-authorised compounds were observed in some baby bottles exceeding 10 µg kg^?1. However, all authorised compounds were detected well below their respective specific migration limits (SMLs). The reference experiment confirmed the migration of some of the compounds previously detected in the EU repetitive-use experiment, though at lower concentrations. Analysis of extracts from the microwave and dishwasher experiments showed a reduction in the migration during the duration tests. In general, the concentrations found were low and comparable with the reference experiment. Similar observations were made for the two sterilisation types: steam and cooking sterilisation. However, steam sterilisation seems to be more recommended for daily use of baby bottles, since it resulted in a lower release of substances afterwards. Repeated use of baby bottles under ‘real-life’ conditions showed no increase in the migration of investigated compounds and, after some time, the migration of these compounds even became negligible.