Dietary Intake and Food Sources of Total and Individual Polyunsaturated Fatty Acids in the Belgian Population Over 15 Years Old

Advances in our knowledge of the physiological functions of dietary polyunsaturated fatty acids (PUFAs) have led to an increased interest in food sources and the level of dietary intake of these nutrients. Up to now, no representative data was available for the Belgian adult population. This study aimed to describe data on the intake and food sources of total and individual omega-6 and omega-3 PUFA for the Belgian population over 15 years old. PUFA intakes were assessed for 3,043 Belgian adults, based on two non-consecutive 24 h recalls. Usual intakes were calculated using the multiple source method. The results showed that the intake of linoleic acid (LA) is in accordance with the recommendation for almost all Belgian adults. However, the intake of omega-3 PUFA is suboptimal for a large part of the studied population and also the intake of total PUFA should be increased for a part of the population. The main food source of LA and α-linolenic acid (ALA) was the group of fats and oils (60.6 % for LA and 53.1 % for ALA). Fish and fish products were the most important sources of long chain omega-3 PUFA. Age influenced fatty acids intake, with higher intake of omega-3 PUFA in the older age groups. To fill the gap between the intake and recommendation of total PUFA, and in particular omega-3 PUFA, sustainable strategies and efficient consumer communication strategies will be needed.     

PP/EMA TPV: Dynamic cross‐linking through an alcoholysis reaction

Dynamically cross‐linked polypropylene/ethylene‐methyl acrylate copolymer (PP/EMA) blends were prepared by reactive extrusion in a twin‐screw extruder. A transesterification reaction catalyzed by an organotin compound and involving the acrylic moieties of EMA with the hydroxyl functions of pentanediol was used to cross‐link the elastomeric EMA. The extent of cross‐linking was estimated through the insoluble content of the blend. The alcohol‐to‐acrylic ratio and the dibutyltin oxide content were both found to increase the extent of EMA cross‐linking. Processing conditions such as screw rotation rate and extrusion temperature profile also had large effects on the reaction extent. Conditions leading to improved pentanediol dispersion were found to generate larger insoluble fraction. Gel contents of EMA phase as high as 75% to 85% were obtained. Interestingly, the stress‐strain curves of the cross‐linked PP/EMA TPV are very well represented by a single master curve. Dynamically cross‐linked blends show systematically better tensile properties than the non‐reactive system. Blends with higher insoluble content show strain at break in the 650%–750% range. Material processability was maintained, even for the systems with high insoluble content.     

Molecular Networking for Drug Toxicities Studies: The Case of Hydroxychloroquine in COVID-19 Patients

Using drugs to treat COVID-19 symptoms may induce adverse effects and modify patient outcomes. These adverse events may be further aggravated in obese patients, who often present different illnesses such as metabolic-associated fatty liver disease. In Rennes University Hospital, several drug such as hydroxychloroquine (HCQ) have been used in the clinical trial HARMONICOV to treat COVID-19 patients, including obese patients. The aim of this study is to determine whether HCQ metabolism and hepatotoxicity are worsened in obese patients using an in vivo/in vitro approach. Liquid chromatography high resolution mass spectrometry in combination with untargeted screening and molecular networking were employed to study drug metabolism in vivo (patient’s plasma) and in vitro (HepaRG cells and RPTEC cells). In addition, HepaRG cells model were used to reproduce pathophysiological features of obese patient metabolism, i.e., in the condition of hepatic steatosis. The metabolic signature of HCQ was modified in HepaRG cells cultured under a steatosis condition and a new metabolite was detected (carboxychloroquine). The RPTEC model was found to produce only one metabolite. A higher cytotoxicity of HCQ was observed in HepaRG cells exposed to exogenous fatty acids, while neutral lipid accumulation (steatosis) was further enhanced in these cells. These in vitro data were compared with the biological parameters of 17 COVID-19 patients treated with HCQ included in the HARMONICOV cohort. Overall, our data suggest that steatosis may be a risk factor for altered drug metabolism and possibly toxicity of HCQ.     

Functional EGFP-dystrophin fusion proteins for gene therapy vector development

Transfection and transduction studies involving the use of thefull-length dystrophin (11 kb) or the truncated mini-gene (6kb) cDNAs are hampered by the large size of the resulting viralor non-viral expression vectors. This usually results in verylow yields of transgene-expressing cells. Moreover, the detectionof the few transgene-expressing cells is often tedious and costly.For these reasons, expression vectors containing the enhancedgreen fluorescent protein (EGFP) fused with the N-termini ofmini- and full-length human dystrophin were constructed. Theseconstructs were tested by transfection of Phoenix cells withEffectene, resulting after 48 h in a green fluorescent signalin 20% of cells. Analysis of the cell extracts by immunoblottingwith the use of a monoclonal antibody specific to the dystrophinC-terminus confirmed the expression of EGFP–mini- (240kDa) and EGFP–full-length human dystrophin (450 kDa) fusionproteins. Moreover, following the in vivo electroporation ofthe plasmids containing the EGFP–mini- and full-lengthdystrophin in mouse muscles, both fluorescent proteins wereobserved in cryostat sections in their normal location underthe plasma membrane. This indicates that the fusion of EGFPto dystrophin or mini-dystrophin did not interfere with thenormal localization of the protein. In conclusion, the fusionof EGFP provides a good tool for the search of the best methodsto introduce mini- or full-length dystrophin cDNA in the cells(in vitro) or muscle fibers (in vivo) for the establishmentof a treatment by gene therapy of Duchenne muscular dystrophypatients.     

Photochromic nanocomposite films of mononitrosyl complexes embedded in polymer matrices

New photochromic nanocomposite films based on mononitrosyl ruthenium complex [RuCl(NO)py₄]²⁺ have been synthesized by dispersion in polymer matrices. Infrared study under irradiation reveals that the composites present very high population of metastable state (≈45%). Nanoparticles of molecular complex stabilized in different matrices have been observed by transmission electron microscopy.     

Influence of mixing characteristics for water encapsulation by self-assembling hydrophobic silica nanoparticles

Water encapsulation using silica nanoparticles was assessed using two different types of single step mixing processes. The influential mixing characteristics have been determined. Direct mixing at high rotational speed requires high shear and vigorous stirring properties. Progressive water atomisation using gentle mixing process requires high atomisation pressure and rapid surface refreshing of the mixed material. Mechanisms of powder formation were also proposed. Encapsulation of micrometric water droplets in shell-like structure is respectively obtained by either progressive size reduction of macroscopic particulates or direct coating of pre-formed microscopic droplets. These mechanisms resulting from the interactions between a solid particle and a liquid highly depend on parameters such as particle's hydrophobicity, surface tension or kinetic energy.     

Rheological characterization of starch derivatives/polycaprolactone blends processed by reactive extrusion

Linear viscoelastic, steady shear behaviors, and morphologies of starch formate/poly(ε-caprolactone) (PCL) blends, compatibilized by oligomers and obtained by reactive extrusion, have been investigated as a function of formic acid (FA)/starch ratio, nature, and molecular weight of the oligomer. The rheological properties of these blends have been compared with those of a commercial starch-based thermoplastic, namely Mater-Bi® ZF03UA. In presence of FA, starch is destructured to starch formate and oligomers are used as plasticizers. The linear viscoelastic response of blends is quite similar to that of nanocomposite materials: the low frequency behavior is attributed to a percolated network of destructured starch particles, and the high frequency behavior is that of the polymer matrix. The viscosity curve presents a profile characterized by two plateau regions, at low and high shear rates. The plateau region at low shear rates corresponds to the viscous response of the blend while that observed at high shear rates can be attributed to the PCL matrix. The compatibilization is enhanced in the presence of starch formate and increases with increasing the oligomer molecular weight. The use of PCL oligomer was shown to improve this compatibilization effect. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

The Esterase PfeE,the Achilles’ Heel in the Battle for Iron between Pseudomonas aeruginosa and Escherichia coli

Bacteria access iron, a key nutrient, by producing siderophores or using siderophores produced by other microorganisms. The pathogen Pseudomonas aeruginosa produces two siderophores but is also able to pirate enterobactin (ENT), the siderophore produced by Escherichia coli. ENT-Fe complexes are imported across the outer membrane of P. aeruginosa by the two outer membrane transporters PfeA and PirA. Iron is released from ENT in the P. aeruginosa periplasm by hydrolysis of ENT by the esterase PfeE. We show here that pfeE gene deletion renders P. aeruginosa unable to grow in the presence of ENT because it is unable to access iron via this siderophore. Two-species co-cultures under iron-restricted conditions show that P. aeruginosa strongly represses the growth of E. coli as long it is able to produce its own siderophores. Both strains are present in similar proportions in the culture as long as the siderophore-deficient P. aeruginosa strain is able to use ENT produced by E. coli to access iron. If pfeE is deleted, E. coli has the upper hand in the culture and P. aeruginosa growth is repressed. Overall, these data show that PfeE is the Achilles’ heel of P. aeruginosa in communities with bacteria producing ENT.