Conjugated linoleic acid reduces permeability and fluidity of adipose plasma membranes from obese Zucker rats

NOTICE: this is the author’s version of a work that was accepted for publication in Biochemical and Biophysical Research Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochemical and Biophysical Research Communications. July 2010; 398 (2): 199-204.Conjugated linoleic acid (CLA) is a dietary fatty acid frequently used as a body fat reducing agent whose effects upon cell membranes and cellular function remain unknown. Obese Zucker rats were fed atherogenic diets containing saturated fats of vegetable or animal origin with or without 1% CLA, as a mixture of cis(c)9,trans(t)11 and t10,c12 isomers. Plasma membrane vesicles obtained from visceral adi- pose tissue were used to assess the effectiveness of dietary fat and CLA membrane incorporation and its outcome on fluidity and permeability to water and glycerol. A significant decrease in adipose membrane fluidity was correlated with the changes observed in permeability, which seem to be caused by the incor- poration of the t10,c12 CLA isomer into membrane phospholipids. These results indicate that CLA supple- mentation in obese Zucker rats fed saturated and cholesterol rich diets reduces the fluidity and permeability of adipose membranes, therefore not supporting CLA as a body fat reducing agent through membrane fluidification in obese fat consumers

Avaliação de traduções: a vez e a voz do aprendiz

According to Education specialists, evaluation is a topic at once controversial and relevant due to its pedagogic, psychological, and socioeconomic implications. In their search for a fair and accurate evaluation, teachers tend to favor practices that are supposedly objective. This paper challenges this notion of objectivity and presents an alternative approach involvinginteraction andnegotiation. These are processes that take into account the inextricable subject/object relationship and the circumstances of each piece of work to be assessed.Segundo especialistas da área da educação, a avaliação constitui tema ao mesmo tempo polêmico e relevante, consideradas suas implicações pedagógicas, psicológicas e sócioeconômicas. Observa-se, entre professores, a tendência a realizarem, sem maior reflexão, práticas avaliatórias de natureza objetivizante na busca de uma avaliação exata e justa. Neste trabalho, faremos a crítica a esse paradigma, ao lado da qual apresentaremos algumas alternativas envolvendo interaçãoe negociação, processos que levam em conta os sujeitos e as circunstâncias implicadas na produção dos trabalhos avaliados

Effect of dietary conjugated linoleic acid isomers on water and glycerol permeability of kidney membranes

NOTICE: this is the author’s version of a work that was accepted for publication in Biochemical and Biophysical Research Communications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Biochemical and Biophysical Research Communications. May 2009; 383(1): 108-112.Conjugated linoleic acid (CLA) refers to a group of positional and geometrical isomers of linoleic acid in which the double bonds are conjugated. Dietary CLA has been associated with various health benefits although details of its molecular mode of action remain elusive. The effect of CLA supplemented to palm oil-based diets in Wistar rats, as a mixture of both or isolated c9,t11 and t10,c12 isomers, was examined on water and glycerol membrane permeability of kidney proximal tubule. Although water permeability was unaltered, an increase in glycerol permeability was obtained for the group supplemented with CLA mixture, even though the activation energy for glycerol permeation remained high. This effect was correlated with an increased CLA isomeric membrane incorporation for the same dietary group. These results suggest that diet supplementation with CLA mixture, in contrast to its individual isomers, may enhance membrane fluidity subsequently raising kidney glycerol reabsorption

Assessment of mixtures of mycotoxins in cereal based foods available in Portuguese market

Mycotoxins are secondary metabolites of fungi that cause toxic and carcinogenic outcomes in humans exposed to them1. Mycotoxins affect several commodities including cereal grains and their finished products, infant formula and baby foods2. This study aimed to determine the incidence and levels of 20 mycotoxins and metabolites (AFB1, AFB2, AFG1, AFG2, AFM1, OTA, NIV, NEO, DAS, FUS-X, DON, 15-AC-DON, 3-AC-DON, HT-2, T-2, VER, T-2 TETROL, T-2 TRIOL), in breakfast cereals and cereal based baby foods available in the Portuguese market, and compare the results with the maximum limits established by the EU. Breakfast cereal samples (n=26), including corn, wheat, oat, rice and multigrain, and twenty cereal based baby foods (n=20) were collected from supermarkets in Lisbon region and analyzed by HPLC-FLD, LC-MS/MS and GC-MS. Results showed that 88 % breakfast cereals samples and 50 % of cereal based baby foods were contaminated with mycotoxins (with values above the detection limit), although all samples presented levels below the maximum limits established by the Commission Regulation 1881/20063. Regarding breakfast cereals samples, OTA and DON were the most commonly detected mycotoxins, with 88% and 73% of samples revealing values above the LOD, respectively. The co-occurrence of different mycotoxins in the same sample was observed in 92% of the analyzed samples. From these, 46% include mixtures of 3 or 4 mycotoxins. Regarding cereal based baby foods, OTA and AFM1 were the most commonly detected mycotoxins with 50% and 40% of samples revealing values above the LOD. The co-occurrence of mycotoxins was observed in 35% of the analyzed samples. These results are accordingly to those reported by Juan et al (2014)4 and Iqbal et al (2014)5. These results contribute to the increased knowledge on mycotoxin contents in cereal based foods marketed in Portugal, and they highlight the deep need of further studies to overcome the absence of legislated limits for mycotoxins in breakfast cereals other than DON and FB1 and the absence of legislated limits for mycotoxin mixtures in food. The last issue is particularly important considering the potential synergistic effects that could occur between mycotoxins and its potential impact on human and, mainly, children health.This research was performed under the MycoMix project (PTDC/DTP-FTO/0417/2012), funded by the Fundação para a Ciência e Tecnologia (FCT), Portuga

Perspective on oleogelator mixtures, structure design and behaviour towards digestibility of oleogels

The concepts of either multi-component supramolecular gels or structures derived from oleogels have not yet been fully investigated to their respective potentials. The study of hybrid structures might cover technological points such as (i) how to vehiculate hydrosoluble and/or liposoluble bioactive components simultaneously? (ii) How could the framework of an oleogel contribute to a specific structure design strategy? (iii) How does oleogels structure influence bioactivity during digestion? A deeper understanding of these issues widens the range of opportunities foreseen for oleogel applications in food matrices. This paper presents the most relevant developments in the field, including the role of ingredients on structured oil-based systems. The authors perspective towards digestibility of oleogels and oleogel-derived structures is also addressed.Paula Kiyomi Okuro thanks FAPESP (grant #2018/20308-3 São Paulo Research Foundation -FAPESP). Rosiane Lopes Cunha thanks CNPqBrazil (307168/2016-6) for the productivity grant.info:eu-repo/semantics/publishedVersio

Evaluation of a chitosan-based edible film as carrier of natamycin to improve the storability of saloio cheese

The purpose of this study was to evaluate the effects of the application of chitosan coating containing natamycin on the physicochemical and microbial properties of semi-hard cheese. Three cheese groups were prepared: samples without coating, samples coated with chitosan and with chitosan containing 0.50 mg mL−1 of natamycin, whose minimum inhibitory concentration was previously determinated on cheese surface. Microbiological analyses showed that natamycin coated samples presented a decrease on moulds/yeasts of 1.1 log (CFU g−1) compared to control after 27 days of storage. Addition of natamycin also affected O2 and CO2 permeability, increasing from 7.12 to 7.68 × 10−15 g·(Pa s m)−1, and from 10.69 to 64.58 × 10−14 g·(Pa s m)−1, respectively. The diffusion coefficient values of natamycin from the film to phosphate buffered saline solution and to the cheese were 3.60 × 10−10 and 1.29 × 10−12 cm2 s−1, respectively. This study demonstrated that chitosan-based coating/films can be used as release system containing natamycin to create an additional hurdle for moulds/yeasts in cheese thus contributing to extend its shelf-life.Plan Galego de Investigación, Desenvolvemento e Innovación Tecnolóxica-Incite (Xunta de GaliciaFundação para a Ciência e a Tecnologia (FCT

Supramolecular dehydropeptide hydrogels: synthesis, properties and biomedical applications

Self-assembled low molecular weight peptide hydrogels have emerged in recent years as the new paradigm in biomaterials research due to their high water content; fully organic struc-ture; intrinsic nontoxicity and biocompatibility and fibrillar nanostructure indicative of the ex-tracellular matrix.1 The properties of peptide hydrogels can be tuned by design and there is a large variety of possible hydrogelator structures using proteinogenic and non proteinogenic aminoacids. Our research group has recently described a series of self-assembled hydrogels based on dehydrodipeptides N-protected with an aromatic moiety. The C-terminal dehy-droaminoacid residue (dehydrophenylalanine, dehydroaminobutyric acid and dehydroalanine) is prone to make the peptide resistant to prote-olysis and restrains the conformational freedom of the peptide.2 In this work the preparation and characterization of the new hydrogelators as well as the corresponding hydrogels will be presented together with some biomedical appli-cations of the new biomaterials prepared name-ly as drug delivery systems or as plataforms for theragnostics.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CQUM (UID/QUI/00686/2016) and CF-UM-UP (UID/FIS/04650/2013 and UID/FIS/04650/ 2019), FEDER, PORTUGAL2020 and COMPETE2020 are also acknowledged for funding under the research projects PTDC/QUI-QFI/28020/2017 (POCI-01-0145-FEDER-028020) and PTDC/QUI-QOR/29015/ 2017 (POCI-01-0145-FEDER-029015)

Hydrogels and nanostructures formed from ciprofloxacin–peptide conjugates

Ciprofloxacin is a broad-spectrum fluoroquinolone antibiotic that possesses potent activity against both Gram-positive and Gram-negative bacteria and is used to treat many infections. Despite its widespread use, ciprofloxacin is associated with side effects, which might be reduced by improving its pharmacokinetic properties. The chemical structure of ciprofloxacin is the source of some of its limitations, which include: (1) Poor membrane permeability due to lipophobicity caused by the presence of polar groups; and (2) poor transportation and absorption due to poor water solubility caused by the flat aromatic structure. Previous methods for improving the pharmacokinetic properties of ciprofloxacin have involved the synthesis of conjugates. Issues related to poor membrane permeability, transportation and absorption of drugs can also be improved by employing nanocarriers and nanomaterials. Encapsulation within nanocarriers allows targeted drug delivery and reduced side effects as lower doses of the drug can be administered. Nanocarriers that can be used for this purpose include nanoparticles and hydrogels. Our research group is interested in supramolecular hydrogels as drug delivery systems. Short amphiphilic peptides are often able to form hydrogels through self-assembly. This present work describes the synthesis of a ciprofloxacin–dehydropeptide conjugate with the aim of forming hydrogels and related nanostructures to be used for the ‘self-delivery’ of antibacterial compounds. We assessed the hydrogelation ability, antibacterial activity, and pharmacokinetic properties. TEM microscopy revealed nanotubes and nanospheres. The conjugate was unable to form hydrogels alone but was able to form hydrogels as the major component of a co-gel with another peptide gelator. Although the conjugate retained antibacterial activity at 400 µM, activity diminished at lower concentrations. Thus, future work should focus on more hydrolysable pro-drug versions of the conjugate or versions where the peptide is connected at an alternate position.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding of CQUM (UID/QUI/00686/2019). FCT, FEDER, PORTUGAL2020, and COMPETE2020 are also acknowledged for funding under research project PTDC/QUI-QOR/29015/2017 (POCI-01-0145-FEDER-029015)

Development and characterization of b-carotene microcapsules composed of starch and protein extract from Amaranth

The 19th Gums & Stabilisers for the Food Industry Conference: Hydrocolloid multifunctionalityStudies that have explored the use of biopolymers of Amaranth as encapsulating materials for bioactive compounds1,2,3 demonstrate that it is possible to isolate and encapsulate bioactive compounds with Amaranth biopolymers. Therefore, the added value of Amaranth can be increased, evidenced and studied through the extraction of its compounds and the formation of microcapsules. The objective of this study was the evaluation of the ability of Amaranth biopolymers to microencapsulate a bioactive compound - -carotene. The microencapsulation was performed by spray drying4, and -carotene was added to the Amaranth (Amaranthus cruentus) starch or protein through a solution prepared at the ratio of 1:10 (polymer:-carotene) in corn oil (1 %). The microcapsules were characterized by mean diameter (volume%), particle size distribution, microcapsules morphology by epifluorescence microscopy, microstructure by scanning electron microscopy (SEM), Fourier Transform infrared spectroscopy (FT-IR) and by measuring encapsulation efficiency. Microcapsules exhibited an average size of 2.22 ± 1.84 m and 1.55 ± 1.12 m for microcapsules composed of Amaranth protein and Amaranth starch, respectively. The microscopy images of both microcapsules showed good sphericity and presence of fluorescence, which indicates good encapsulation capacity of -carotene. FT-IR results showed no differences between spectra of all samples, which indicates that there was no chemical bonding between the capsules and -carotene, but rather an entrapment of -carotene into starch and protein microparticles. The encapsulation efficiency was 71.29 % and 69.32 % for Amaranth starch and protein microcapsules, respectively. Therefore, it can be concluded that the biopolymers extracted from Amaranth can be considered good encapsulating agents for bioactive compounds, thus valorising their use in food formulations.This study was funded by the CNPQ-Brazil; FCT – Portugal (SFRH/BPD/89992/2012, SFRH/BPD/101181/2014, SFRH/BPD/104712/2014 and IF/00300/2015 fellowships); Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER- 027462); Project UID/BIO/04469/2013 unit, COMPETE 2020 (POCI-01-0145-FEDER- 006684) and Project CICECO-Aveiro Institute of Materials POCI-01-0145-FEDER-007679 (FCT UID/CTM/50011/2013).info:eu-repo/semantics/publishedVersio

Purification of plasmids using aqueous two-phase systems with amino affinity ligands

The increasing development and future application of molecular therapies such as gene therapy and DNA vaccination is expected to have a great impact in health care. However for their wide application large amounts of plasmid DNA (pDNA) are required with a stringent clearance of impurities. This prompted the development of new, efficient and cost-effective large-scale processes for the production and purification of pDNA. Most of the purification processes described are based on chromatography but dispite their high resolution, frequently they are difficult to scale-up, have low capacity and present low yields. In order to overcome these disadvantages other methodologies are also being developed. Aqueous two-phase systems (ATPS) are one of the most promising approaches for pDNA purification given their several advantages like easy scale-up, high capacity and the possibility of continuous operation. Despite their great potential ATPS have low selectivity, which limits the purification outcome. The addition of certain molecules with affinity for the target molecules (pDNA in this case) may increase their selectivity. In this work it was studied the possibility of using amino ligands for the affinity purification of pDNA from bacterial alkaline lysates. Two free amino acids, lysine and arginine, their respective Polyethylene glycol (PEG) conjugates, PEG-lysine and PEGarginine, and PEGamine were tested. The system used was composed of 16,2% (w/w) PEG 600 and 17,4% (w/w) dextran 100 (DEX) and it was evaluate the ability of each ligand to steer the pDNA to the phase where less impurities are accumulated (PEG rich phase). The results show that free amino acids did not have any effect on pDNA partitioning but the PEG conjugates were able to steer the pDNA to the PEG phase, at low concentrations. With the addition of 0,2% of PEG-lysine, or 0,5% of PEG-arginine or 4% of PEG-amine in relation to the total PEG, all the pDNA is recovered in the PEG phase. However it presents some RNA contamination, that could be removed by re-extracting with a new phase containing 30% of ammonium sulphate (NH4)2S04. The purified pDNA is obtained in the bottom phase of this new system with no measurable presence of RNA or proteins