159 research outputs found
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
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
Biodegradable nanofibers-reinforced microfibrous composite scaffolds for bone tissue engineering
Native bone extracellular matrix (ECM) is a complex hierarchical fibrous composite structure, resulting from the
assembling of collagen fibrils at several length scales, ranging from the macro to the nanoscale. The combination
of nanofibers within microfibers after conventional reinforcement methodologies seems to be a feasible solution
to the rational design of highly functional synthetic ECM substitutes. The present work aims at the development
of bone ECM inspired structures, conjugating electrospun chitosan (Cht) nanofibers within biodegradable
polymeric microfibers [poly(butylene succinate)—PBS and PBS/Cht], assembled in a fiber mesh structure. The
nanofibers-reinforced composite fiber mesh scaffolds were seeded with human bone marrow mesenchymal stem
cells (hBMSCs) and cultured under osteogenic differentiation conditions. These nanofibers-reinforced composite
scaffolds sustained ECM deposition and mineralization, mainly in the PBS/Cht-based fiber meshes, as depicted
by the increased amount of calcium phosphates produced by the osteogenic differentiated hBMSCs. The osteogenic
genotype of the cultured hBMSCs was confirmed by the expression of osteoblastic genes, namely Alkaline
Phosphatase, Osteopontin, Bone Sialoprotein and Osteocalcin, and the transcription factors Runx2 and Osterix, all
involved in different stages of the osteogenesis. These data represent the first report on the biological functionality
of nanofibers-reinforced composite scaffolds, envisaging the applicability of the developed structures
for bone tissue engineering.This work was partially supported by the European Network of Excellence EXPERTISSUES (NMP3-CT-2004-500283). It was also acknowledged by the Portuguese Foundation for Science and Technology for the Ph.D. grant of A. Martins (SFRH/BD/24382/2005)
Risk assessment of exposure to multiple mycotoxins in the Icelandic population
Background: The proliferation of mycotoxin-producing fungi in agricultural settings poses a challenge to human health and nutrition around the world. Mycotoxins contaminate food sources and their negative health outcomes include carcinogenic, nephrotoxic, and teratogenic effects. Potential risks are still poorly characterized and few studies assess exposure at an individual level. Thus, the goal of this study was to assess and characterize exposure risk to multiple mycotoxins in the Icelandic population. Methods: Urine samples and data on urinary mycotoxin biomarkers (deoxynivalenol, zearalenone, and ochratoxin A) from a pool of 171 individuals living in Iceland between 2020 and 2021 were used to estimate external doses through reverse dosimetry. For risk characterization, Hazard Quotient (HQ) and Margin of Exposure (MoE) approaches were applied for deoxynivalenol zearalenone, and ochratoxin A, respectively. Results: The Icelandic population was revealed to be exposed to multiple mycotoxins. Mean levels of deoxynivalenol and ochratoxin A were comparable to what have been reported in other European studies, while levels of zearalenone were considerably lower. Nevertheless, risk assessment revealed safe levels of exposure to deoxynivalenol and zearalenone (HQ < 1) but MoE based on a neoplastic endpoint to ochratoxin A indicated a possible health concern for all participants (MoE < 10000). Conclusions: Although there are some uncertainties associated with a human biomonitoring approach, the results of this study confirm that mycotoxins are a growing threat to public health in the European continent. Since countries with different latitudes already present comparable levels of exposure, this is especially concerning in a climate change scenario. Further studies both on exposure assessment and specific effects on human health are required to accurately assess risk and introduce preventive measures.info:eu-repo/semantics/publishedVersio
Studies on sorption and regeneration of granulated cork for oil and grease removal
The aim of this work is to develop a method to recover sorbed oil and grease from granulated cork, in order to promote biomass regeneration. Experimental procedure involved biomass saturation with oil, followed by chemical regeneration. Oil removal by elution was tested using HNO3 and NaOH solutions, cationic and anionic surfactants and organic solvents, namely carbon tetrachloride and n-hexane. Chemical desorption efficiency using organic solvents achieved values of 90 ± 6 % and 72 ± 6 % for CCl4 and n-hexane, respectively. Although the use of organic solvents proved to be an efficient process, it involves high costs and a negative environmental impact. Physical regeneration could be an alternative to the use of solvents for oil removal from granulated cork.This work is supported by project HIDROCORK “Utilization of Cork Wastes and By-Products for Elimination of Oils and Fats from Waters”, financed by QREN (National Strategic Reference Framework). This work is also partially supported by project PEst-C/EQB/LA0020/2011, financed by FEDER through COMPETE - Programa Operacional Factores de Competitividade and by FCT - Fundação para a Ciência e a Tecnologia. A. Pintor also acknowledges her PhD fellowship by FCT (SFRH / BD / 70142 / 2010)
Valorisation of cork by-products for the treatment of vegetal and animal oil containing wastewaters
In this study, cork granules, which are by-products of the cork processing industry, were used as biosorbents for the removal of vegetable and animal oils from water. Simple oil-in-water emulsions were created by ultrasonic emulsification and batch adsorption tests were performed by contacting cork with these emulsions for a defined period of time. A mass transfer model was able to predict adequately the kinetic data, using a Linear Driving Force approximation for intraparticle diffusion and equilibrium described by the Langmuir-Freundlich equation. Maximum sorption capacities for vegetable and animal oil, as calculated by the Langmuir-Freundlich model, were 5 ± 4 and 2.3 ± 0.9 g g-1, respectively. Therefore, expanded cork granules proved to be an efficient, low-cost sorbent for both vegetable and animal oilsThis work is supported by project HIDROCORK “Utilization of Cork Wastes and By-Products for Elimination of Oils and Fats from Waters”, supported by QREN (National Strategic Reference Framework). This work is also partially supported by project PEst-C/EQB/LA0020/2011, financed by FEDER through COMPETE -Programa Operacional Factores de Competitividade and by FCT -Fundação para a Ciência e a Tecnologia
Nutritional characterization of Strychnos madagascariensis fruit flour produced by Mozambican communities and evaluation of Its contribution to nutrient adequacy
The indigenous fruit Strychnos madagascariensis is usually processed to flour, called nfuma, being highly consumed during staple food shortage. This study aimed to evaluate the nutritional composition of nfuma and its nutrient adequacy. Flours from four districts of Mozambique were analyzed using AOAC methods for proximate composition, HPLC for sugar, amino acids (AA), vitamin E and carotenoids and ICP-MS and FAAS for minerals. The results showed that nfuma stands out for its high content of fat (26.3–27.8%), mainly oleic acid, fiber (>6%), vitamin E (6.7 to 8.0 mg/100 g) and carotenes (2.2 to 2.6 mg/100 g). The main amino acids of nfuma protein were Arg, Asp and Glu, and Lys was the limiting one. The mineral composition reveals K (~1200 to 1700 mg/100 g) as the main macromineral followed by Mg > Ca > Na. The main trace element was Mn (~4 mg/100 g) followed by Fe > Zn > Cu > Cr > Co. Aluminum (~3 mg/100 g) was the main non-essential element and Rb, Ni, Sr, Ba, V, Cd were also quantified. Assuming the daily consumption of 50 g, nfuma provides 82% of Vitamin A dietary reference value for toddlers, while the consumption of 100 g contributes to 132% and 60% of Mn and vitamin A DRV for adults, respectively. Despite the nutritional advantages of nfuma, this flour can be a source of Ni, highlighting the importance of the study of good practices in its preparation to decrease the exposure to non-essential elements.info:eu-repo/semantics/publishedVersio
The amino acids motif-32GSSYN36-in the catalytic domain of E. coli flavorubredoxin NO reductase is essential for its activity
Funding Information: Funding: This study was financially supported by the Portuguese Fundação para a Ciência e Tec-nologia (FCT), grants PTDC/BIA-BQM/27959/2017 and PTDC/BIA-BQM/0562/2020, and Project MOSTMICRO-ITQB with references UIDB/04612/2020 and UIDP/04612/2020. This project has also received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement 810856. MCM is the recipient of FCT grant SFRH/BD/143651/2019. BAS is the recipient of FCT grant DFA/BD/8066/2020. Funding Information: This study was financially supported by the Portuguese Funda??o para a Ci?ncia e Tecnologia (FCT), grants PTDC/BIA-BQM/27959/2017 and PTDC/BIA-BQM/0562/2020, and Project MOSTMICRO-ITQB with references UIDB/04612/2020 and UIDP/04612/2020. This project has also received funding from the European Union?s Horizon 2020 research and innovation program under grant agreement 810856. MCM is the recipient of FCT grant SFRH/BD/143651/2019. BAS is the recipient of FCT grant DFA/BD/8066/2020. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Flavodiiron proteins (FDPs) are a family of modular and soluble enzymes endowed with nitric oxide and/or oxygen reductase activities, producing N2O or H2O, respectively. The FDP from Escherichia coli, which, apart from the two core domains, possesses a rubredoxin-like domain at the C-terminus (therefore named flavorubredoxin (FlRd)), is a bona fide NO reductase, exhibiting O2 reducing activity that is approximately ten times lower than that for NO. Among the flavorubredoxins, there is a strictly conserved amino acids motif,-G[S,T]SYN-, close to the catalytic diiron center. To assess its role in FlRd’s activity, we designed several site-directed mutants, replacing the conserved residues with hydrophobic or anionic ones. The mutants, which maintained the general characteristics of the wild type enzyme, including cofactor content and integrity of the diiron center, revealed a decrease of their oxygen reductase activity, while the NO reductase activity—specifically, its physiological function—was almost completely abolished in some of the mutants. Molecular modeling of the mutant proteins pointed to subtle changes in the predicted structures that resulted in the reduction of the hydration of the regions around the conserved residues, as well as in the elimination of hydrogen bonds, which may affect proton transfer and/or product release.publishe
Quality of life as a prognostic marker in pulmonary arterial hypertension
Background: Improvement in quality of life together with better survival are the ultimate goals in the treatment of pulmonary arterial hypertension (PAH) patients. the objective of this study was to evaluate the health-related quality of life (HRQL) of pulmonary arterial hypertension (PAH) patients with the SF-36 generic questionnaire and to identify the prognostic implication of this assessment.Methods: Fifty-four consecutive newly diagnosed PAH patients (WHO classification group I) in a single PAH reference center were included. Patients were evaluated at baseline for clinical and hemodynamic parameters, and they subsequently received first-line therapy with either an endothelin receptor antagonist or a phosphodiesterase-5 inhibitor. After 16 weeks of specific PAH therapy, all patients were re-evaluated using a 6MWT and a SF 36 questionnaire, and then they were followed up for at least 36 months.Results: After treatment, the patients demonstrated an improved 6MWT (414 +/- 124 m vs. 440 +/- 113 m, p = 0.001). Specific PAH therapy also improved the HRQL scores.Patients with a baseline Physical Component Score (PCS) higher than 32 had a better survival rate than those who had a score under 32 (p = 0.04). Similarly, patients with a PCS of at least a 38 after the 16 week therapy period had a better survival rate when compared with those who did not achieve this value (p = 0.016). Unlike the absolute PCS values, the post-treatment PCS variability was unable to predict better survival rates (p = 0.58).Conclusions: Our findings suggest that HRQL is associated with prognosis in PAH. Furthermore, achieving pre-determined PCS scores might represent a specific goal to be reached in treatment-to-target strategies.Univ São Paulo, Sch Med, Pulm Dept, Inst Heart, BR-05403000 São Paulo, BrazilUniversidade Federal de São Paulo, Rheumatol Dept, São Paulo, BrazilUniversidade Federal de São Paulo, Rheumatol Dept, São Paulo, BrazilWeb of Scienc
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