258 research outputs found
Biosynthesis of Crystalline Silver and Gold Nanoparticles by Extremophilic Yeasts
The biosynthesis of Ag and Au nanoparticles (NPs) was investigated using an extremophilic yeast strain isolated from acid mine drainage in Portugal. Three distinct studies were performed, namely, the growth of yeast strain in presence of metal ions, the use of yeast biomass for the metal nanoparticles synthesis, and of the supernatant obtained after 24-hour incubation of yeast biomass in water. The extremophilic strain under study was able to grow up to an Ag ion concentration of 1.5 mM whereas an increase of Au ion concentration over 0.09 mM caused a strong inhibitory effect. A successful route for the metal NPs synthesis was obtained using the yeast biomass. When the washed yeast cells were in contact with Ag or Au solutions, AgNPs smaller than 20 nm were produced, as for the AuNPs diameter ranged from 30 to 100 nm, as determined through transmission electron microscopy and confirmed by energy-dispersive X-ray spectra. The supernatant-based strategy provided evidence that proteins were released to the medium by the yeasts, which could be responsible for the formation and stabilisation of the Ag NPs, although the involvement of the cell wall seems fundamental for AuNPs synthesis
Cork oak forests soil bacteria: potential for sustainable agroforest production
Plant growth promoting rhizobacteria (PGPR) are in increasing demand due to their role in promoting sustainable practices, not only in agriculture but also in forestry. Keeping in mind the future application of PGPR for increasing cork oak sustainability, the aim of this study was to find cork oak PGPR isolates with increased nutrient solubilisation traits, able to promote root morphological changes and/or antagonize cork oak bark phytopathogens. Soils from three cork oak forests with distinct bioclimates (humid, semi-humid and semi-arid) were used for isolating bacteria. From the 7634 colony-forming units, 323 bacterial isolates were biochemically assayed for PGPR traits (siderophores production, phosphate solubilizing and organic acids production), and 51 were found to display all these traits. These PGPR were able to induce root morphological changes on Arabidopsis thaliana, like suppression of primary root growth, increase of lateral roots or root hairs formation. However, the most proficient PGPR displayed specific ability in changing a single root morphological trait. This ability was related not only to bacterial genotype, but also with the environment where bacteria thrived and isolation temperature. Bacteria from semi-arid environments (mainly Bacillus megaterium isolates) could hold a promising tool to enhance plant development. Other isolates (Serratia quinivorens or B. cereus) could be further explored for biocontrol purposes.This work was supported by FEDER funds through COMPETE (Programa Operacional Factores de Competitividade) and by national funds by FCT (Fundação para a Ciência e a Tecnologia) in
the framework of the projects SuberControl (PTDC/ASP-SIL/28635/2017), BioISI (UIDB/04046/2020)
and CIMO (UIDB/00690/2020)
A new method for testing antimicrobial activity of filamentous fungi
Tbls work was supporled by a FCT projecl (PTDC/AGR-AAM/099556/2008)
Human Extracellular-Matrix Functionalization of 3D hiPSC-Based Cardiac Tissues Improves Cardiomyocyte Maturation
The work here presented was funded by Fundacao para a Ciencia e Tecnologia (FCT) projects NETDIAMOND (SAICTPAC/0047/2015), financially supported by FEEI-Lisboa2020 and FCT/POCI-01-0145-FEDER-016385, and MetaCardio (PTDC/BTM-SAL/32566/2017); iNOVA4-Health -UIDB/04462/2020 and UIDP/04462/2020, a program financially supported by FCT/Ministerio da Ciencia, Tecnologia e Ensino Superior, through national funds is acknowledged; Funding from INTERFACE Programme, through the Innovation, Technology and Circular Economy Fund (FITEC), is gratefully acknowledged; and EU-funded projects BRAV3 (H2020, ID:874827) and ERAatUC (ref. 669088). HVA, AFL, and DS were financed by FCT Grants SFRH/BPD/120595/2016 and PD/BD/139078/2018 and PD/BD/106051/2015, respectively.Human induced pluripotent stem cells (hiPSC) possess significant therapeutic potential due to their high self-renewal capability and potential to differentiate into specialized cells such as cardiomyocytes. However, generated hiPSC-derived cardiomyocytes (hiPSC-CM) are still immature, with phenotypic and functional features resembling the fetal rather than their adult counterparts, which limits their application in cell-based therapies, in vitro cardiac disease modeling, and drug cardiotoxicity screening. Recent discoveries have demonstrated the potential of the extracellular matrix (ECM) as a critical regulator in development, homeostasis, and injury of the cardiac microenvironment. Within this context, this work aimed to assess the impact of human cardiac ECM in the phenotype and maturation features of hiPSC-CM. Human ECM was isolated from myocardium tissue through a physical decellularization approach. The cardiac tissue decellularization process reduced DNA content significantly while maintaining ECM composition in terms of sulfated glycosaminoglycans (s-GAG) and collagen content. These ECM particles were successfully incorporated in three-dimensional (3D) hiPSC-CM aggregates (CM+ECM) with no impact on viability and metabolic activity throughout 20 days in 3D culture conditions. Also, CM+ECM aggregates displayed organized and longer sarcomeres, with improved calcium handling when compared to hiPSC-CM aggregates. This study shows that human cardiac ECM functionalization of hiPSC-based cardiac tissues improves cardiomyocyte maturation. The knowledge generated herein provides essential insights to streamline the application of ECM in the development of hiPSC-based therapies targeting cardiac diseases.publishersversionpublishe
Does the intake of LC-PUFAS during pregnancy affect the body composition of term neonates? Preliminary results
Background: The effect of the intake of polynsaturated long chain fatty acids (LCPUFAs) during pregnancy on fetal body composition has been assessed by studies using mostly neonatal anthropometry. Their results have been inconsistent, probably because neonatal anthropometry has several validity limitations. Air displacement plethismography (ADP) is a recently validated non-invasive method for assessing body composition in neonates. Objective: To determine the effect of the intake of LCPUFAs during pregnancy on the body composition of term neonates, measured by ADP. Methods: Cross-sectional study of a convenience sample of healthy full-term neonates and their mothers. The diet during pregnancy was assessed using a validated semi-quantitative food frequency questionnaire; Food Processor Plus® was used to convert food intake into nutritional values. Body composition was estimated by anthropometry and measured by ADP using Pea Pod™ Life Measurements Inc (fat mass - FM, fat-free mass and %FM) within the first 72h after birth. Univariate and multivariate analysis (linear regression model) were performed. Results: 54 mother-neonate pairs were included. Multivariate analysis adjusted to the maternal body mass index shows positive association between LCPUFAs intake and neonatal mid-arm circumference (= 0,610, p = 0,019) and negative association between n-6:n-3 ratio intake and neonatal %FM (= -2,744, p=0,066). Conclusion: To the best of our knowledge, this is the first study on this subject using ADP and showing a negative association between LCPUFAs n-6:n-3 ratio intake in pregnancy and neonatal %FM. This preliminary finding requires confirmation increasing the study power with a greater sample and performing interventional studies
Exosomes secreted by cardiomyocytes subjected to ischaemia promote cardiac angiogenesis
Funding Information: This work was supported by European Regional Development Fund (FEDER) through the Operational Program for Competitiveness Factors (COMPETE) [HealthyAging2020 CENTRO-01-0145-FEDER-000012-N2323, POCI-01-0145-FEDER-016385, POCI-01-0145-FEDER-007440 to CNC.IBILI, POCI-01-0145-FEDER-007274 to i3S/INEB and NORTE-01-0145-FEDER-000012 to T.L.L.]; national funds through the Portuguese Foundation for Science and Technology (FCT) [PTDC/SAU-ORG/119296/2010, PTDC/ NEU-OSD/0312/2012, PESTC/ SAU/UI3282/2013-2014, MITP-TB/ECE/0013/ 2013, FCT-UID/NEU/04539/2013], PD/BD/52294/2013 to T.M.R.R., SFRH/ BD/85556/2012 (co-financed by QREN) to V.C.S]; Lisboa Portugal Regional Operational Programme (LISBOA 2020) and Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement; and by INFARMED Autoridade Nacional do Medicamento e Produtos de Saúde, I.P. [FIS-FIS-2015-01_CCV_20150630-157]. Publisher Copyright: © 2017 The Author.Aims Myocardial infarction (MI) is the leading cause of morbidity and mortality worldwide and results from an obstruction in the blood supply to a region of the heart. In an attempt to replenish oxygen and nutrients to the deprived area, affected cells release signals to promote the development of new vessels and confer protection against MI. However, the mechanisms underlying the growth of new vessels in an ischaemic scenario remain poorly understood. Here, we show that cardiomyocytes subjected to ischaemia release exosomes that elicit an angiogenic response of endothelial cells (ECs). Methods and results Exosomes secreted by H9c2 myocardial cells and primary cardiomyocytes, cultured either in control or ischaemic conditions were isolated and added to ECs. We show that ischaemic exosomes, in comparison with control exosomes, confer protection against oxidative-induced lesion, promote proliferation, and sprouting of ECs, stimulate the formation of capillary-like structures and strengthen adhesion complexes and barrier properties. Moreover, ischaemic exosomes display higher levels of metalloproteases (MMP) and promote the secretion of MMP by ECs. We demonstrate that miR-222 and miR-143, the relatively most abundant miRs in ischaemic exosomes, partially recapitulate the angiogenic effect of exosomes. Additionally, we show that ischaemic exosomes stimulate the formation of new functional vessels in vivo using in ovo and Matrigel plug assays. Finally, we demonstrate that intramyocardial delivery of ischaemic exosomes improves neovascularization following MI. Conclusions This study establishes that exosomes secreted by cardiomyocytes under ischaemic conditions promote heart angiogenesis, which may pave the way towards the development of add-on therapies to enhance myocardial blood supply.publishersversionpublishe
B Cell Numbers Predict Humoral and Cellular Response Upon SARS–CoV-2 Vaccination Among Patients Treated With Rituximab
Objective: Patients with autoimmune inflammatory rheumatic diseases receiving rituximab (RTX) therapy are at higher risk of poor COVID-19 outcomes and show substantially impaired humoral immune response to anti-SARS-CoV-2 vaccine. However, the complex relationship between antigen-specific B cells and T cells and the level of B cell repopulation necessary to achieve anti-vaccine responses remain largely unknown.
Methods: Antibody responses to SARS-CoV-2 vaccines and induction of antigen-specific B and CD4/CD8 T cell subsets were studied in 19 patients with rheumatoid arthritis (RA) or antineutrophil cytoplasmic antibody-associated vasculitis receiving RTX, 12 patients with RA receiving other therapies, and 30 healthy controls after SARS-CoV-2 vaccination with either messenger RNA or vector-based vaccines.
Results: A minimum of 10 B cells per microliter (0.4% of lymphocytes) in the peripheral circulation appeared to be required for RTX-treated patients to mount seroconversion to anti-S1 IgG upon SARS-CoV-2 vaccination. RTX-treated patients who lacked IgG seroconversion showed reduced receptor-binding domain-positive B cells (P = 0.0005), a lower frequency of Tfh-like cells (P = 0.0481), as well as fewer activated CD4 (P = 0.0036) and CD8 T cells (P = 0.0308) compared to RTX-treated patients who achieved IgG seroconversion. Functionally relevant B cell depletion resulted in impaired interferon-γ secretion by spike-specific CD4 T cells (P = 0.0112, r = 0.5342). In contrast, antigen-specific CD8 T cells were reduced in both RA patients and RTX-treated patients, independently of IgG formation.
Conclusion: In RTX-treated patients, a minimum of 10 B cells per microliter in the peripheral circulation is a candidate biomarker for a high likelihood of an appropriate cellular and humoral response after SARS-CoV-2 vaccination. Mechanistically, the data emphasize the crucial role of costimulatory B cell functions for the proper induction of CD4 responses propagating vaccine-specific B cell and plasma cell differentiation
A comprehensive assessment of the transcriptome of cork oak (Quercus suber) through EST sequencing
Background: Cork oak (Quercus suber) is one of the rare trees with the ability to produce cork, a material widely used to make wine bottle stoppers, flooring and insulation materials, among many other uses. The molecular mechanisms of cork formation are still poorly understood, in great part due to the difficulty in studying a species with a long life-cycle and for which there is scarce molecular/genomic information. Cork oak forests are of great ecological importance and represent a major economic and social resource in Southern Europe and Northern Africa. However, global warming is threatening the cork oak forests by imposing thermal, hydric and many types of novel biotic stresses. Despite the economic and social value of the Q. suber species, few genomic resources have been developed, useful for biotechnological applications and improved forest management.
Results: We generated in excess of 7 million sequence reads, by pyrosequencing 21 normalized cDNA libraries derived from multiple Q. suber tissues and organs, developmental stages and physiological conditions. We deployed a stringent sequence processing and assembly pipeline that resulted in the identification of ~159,000 unigenes. These were annotated according to their similarity to known plant genes, to known Interpro domains, GO classes and E.C. numbers. The phylogenetic extent of this ESTs set was investigated, and we found that cork oak revealed a significant new gene space that is not covered by other model species or EST sequencing projects. The raw data, as well as the full annotated assembly, are now available to the community in a dedicated web portal at http://www.corkoakdb.org.
Conclusions: This genomic resource represents the first trancriptome study in a cork producing species. It can be explored to develop new tools and approaches to understand stress responses and developmental processes in forest trees, as well as the molecular cascades underlying cork differentiation and disease response.Peer Reviewe
Nutritional profile and obesity: results from a random‑sample population‑based study in Córdoba, Argentina
Introduction Obesity is a chronic, heterogeneous, multifactorial disease, which has sharply increased in prevalence in both developed and developing countries. This study aimed to estimate the prevalence of obesity and to identify socio-demographic risk factors associated with it, with special emphasis on diet. Methods Nutritional status, demographic characteristics, lifestyle habits, and food consumption patterns derived from a Food Frequency Questionnaire were investigated. Exhaustive exploratory analyses were performed in order to describe dietary patterns, and logistic regression models were used for odds ratio estimation.
Results The study included 4328 subjects, over 18 years old and resident in Cordoba city. The prevalence of overweight and obesity was 34 and 17 %, respectively, with 60 % in men and 45 % in women of BMI ≥ 25. Obesity risk factors were high intake of sodium, refined grains, starchy vegetables, and snacks. A lower risk of overweight and obesity was associated with an adequate, moderate intake of meats, eggs, alcoholic beverages, sugar and sweets, milk, yogurt, and pulses. Conclusions A high intake of snacks, refined grains, starchy vegetables and sodium and low intake of yogurt, milk, pulses, and whole grains seem to be associated with the emergence and high prevalence of obesity in Cordoba, Argentina.publishedVersionFil: Aballay, Laura Rosana. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Nutrición. Estadística y Bioestadística; ArgentinaFil: Aballay, Laura Rosana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ciencias de la Salud; Argentina.Fil: De la Quintana, Ana Gabriela. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Nutrición; Argentina.Fil: Díaz, María del Pilar. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Nutrición. Estadística y Bioestadística; Argentina.Fil: Díaz, María del Pilar. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ciencias de la Salud; Argentina.Fil: Osella, Alberto R. Hospital Saverio de Bellis. Laboratorio de Epidemiologia y Bioestadística; Italia
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