103 research outputs found
High-throughput Agrobacterium-mediated barley transformation
<p>Abstract</p> <p>Background</p> <p>Plant transformation is an invaluable tool for basic plant research, as well as a useful technique for the direct improvement of commercial crops. Barley (<it>Hordeum vulgare</it>) is the fourth most abundant cereal crop in the world. It also provides a useful model for the study of wheat, which has a larger and more complex genome. Most existing barley transformation methodologies are either complex or have low (<10%) transformation efficiencies.</p> <p>Results</p> <p>A robust, simple and reproducible barley transformation protocol has been developed that yields average transformation efficiencies of 25%. This protocol is based on the infection of immature barley embryos with <it>Agrobacterium </it>strain AGL1, carrying vectors from the pBract series that contain the <it>hpt </it>gene (conferring hygromycin resistance) as a selectable marker. Results of large scale experiments utilising the <it>luc </it>(firefly luciferase) gene as a reporter are described. The method presented here has been used to produce hundreds of independent, transgenic plant lines and we show that a large proportion of these lines contain single copies of the <it>luc </it>gene.</p> <p>Conclusion</p> <p>This protocol demonstrates significant improvements in both efficiency and ease of use over existing barley transformation methods. This opens up opportunities for the development of functional genomics resources in barley.</p
Iron Deficiency and Obesity - Are we Diagnosing with Appropriate Indicators?
INTRODUCTION:
We aim to define the iron deficiency prevalence and eventual differences between obese patients with and without metabolic syndrome.
MATERIAL AND METHODS:
Analysis of patients evaluated at multidisciplinary consultation of obesity in our institution between 2013 and 2015 (n = 260). Iron deficiency: ferritin levels < 15 ng/mL.
EXCLUSION CRITERIA:
prior bariatric surgery; lack of ferritin or hemoglobin determinations.
RESULTS:
We analyzed data from 215 patients (84.2% female) with a mean age of 42.0 ± 10.3 years. The median body mass index was 42.5 (40.0 - 46.8) kg/m2 and 52.1% had metabolic syndrome. Iron deficiency was present in 7.0%, with no differences between genders or between patients with or without metabolic syndrome. Hypertension was associated with lower prevalence of iron deficiency. Type 2 diabetes and hypertension patients had higher levels of ferritin. The multivariate analysis showed that metabolic syndrome and increasing body mass index were predictive of higher risk of iron deficiency while hypertension predicted lower odds of iron deficiency.
DISCUSSION:
The prevalence of iron deficiency was similar in other published studies. Iron deficiency may be underdiagnosed if based only on ferritin concentrations. In our study, diabetes and hypertension appear to contribute to the increase in ferritin levels described in obesity.
CONCLUSION:
Ferritin may not be a reliable index for evaluating iron stores in obese patients, particularly when associated with comorbidities such as type 2 diabetes and hypertension. Further studies are needed to guide the diagnosis and iron supplementation in these patients.info:eu-repo/semantics/publishedVersio
Deacetylation and Desuccinylation of the Fucose-Rich Polysaccharide Fucopol: Impact on Biopolymer Physical and Chemical Properties
FucoPol is an acylated polysaccharide with demonstrated valuable functional properties
that include a shear thinning fluid behaviour, a film-forming capacity, and an emulsion forming
and stabilizing capacity. In this study, the different conditions (concentration, temperature, and
time) for alkaline treatment were investigated to deacylate FucoPol. Complete deacetylation and
desuccinylation was achieved with 0.02 M NaOH, at 60 ÂşC for 15 min, with no significant impact on
the biopolymer’s sugar composition, pyruvate content, and molecular mass distribution. FucoPol
depyruvylation by acid hydrolysis was attempted, but it resulted in a very low polymer recovery. The
effect of the ionic strength, pH, and temperature on the deacetylated/desuccinylated polysaccharide,
d-FucoPol, was evaluated, as well as its emulsion and film-forming capacity. d-FucoPol aqueous
solutions maintained the shear thinning behaviour characteristic of FucoPol, but the apparent viscosity
decreased significantly. Moreover, contrary to FucoPol, whose solutions were not affected by the
media’s ionic strength, the d-FucoPol solutions had a significantly higher apparent viscosity for
a higher ionic strength. On the other hand, the d-FucoPol solutions were not affected by the pH
in the range of 3.6–11.5, while FucoPol had a decreased viscosity for acidic pH values and for a
pH above 10.5. Although d-FucoPol displayed an emulsification activity for olive oil similar to
that of FucoPol (98 +- 0%) for an oil-to-water ratio of 2:3, the emulsions were less viscous. The
d-FucoPol films were flexible, with a higher Young0s modulus (798 +- 152 MPa), a stress at the
break (22.5 +- 2.5 MPa), and an elongation at the break (9.3 +- 0.7%) than FucoPol (458 +- 32 MPa,
15.5 +- 0.3 MPa and 8.1 +- 1.0%, respectively). Given these findings, d-FucoPol arises as a promising
novel biopolymer, with distinctive properties that may render it useful for utilization as a suspending
or emulsifier agent, and as a barrier in coatings and packaging filmsinfo:eu-repo/semantics/publishedVersio
An update on wastewater multi-resistant bacteria : identification of clinical pathogens such as Escherichia coli O25b:H4-B2-ST131-producing CTX-M-15 ESBL and KPC-3 Carbapenemase-Producing Klebsiella oxytoca
© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Wastewater treatment plants (WWTPs) are significant reservoirs of bacterial resistance. This work aims to identify the determinants of resistance produced by Gram-negative bacteria in the influent and effluent of two WWTPs in Portugal. A total of 96 wastewater samples were obtained between 2016 and 2019. The numbers of total aerobic and fecal contamination bacteria were evaluated, and genomic features were searched by polymerase chain reaction (PCR) and Next-Generation Sequencing (NGS). Enterobacteriaceae corresponded to 78.6% (n = 161) of the 205 isolates identified by 16sRNA. The most frequent isolates were Escherichia spp. (57.1%, n = 117), followed by Aeromonas spp. (16.1%, n = 33) and Klebsiella spp. (12.7%, n = 26). The remaining 29 isolates (14.1%) were distributed across 10 different genera. Among the 183 resistant genes detected, 54 isolates produced extended spectrum β-lactamases (ESBL), of which blaCTX-M-15 was predominant (37 isolates; 68.5%). A KPC-3 carbapenemase-producing K. oxytoca was identified (n = 1), with blaKPC-3 included in a transposon Tn4401 isoform b. A higher number of virulence genes (VG) (19 genes) was found in the E. coli 5301 (O25b-ST131-B2) isolate compared with a commensal E. coli 5281 (O25b-ST410-A) (six genes). Both shared five VG [Enterobactin; Aerobactin, CFA/1 (clade α); Type1 (clade γ1); Type IV]. In conclusion, this work highlights the role of relevant clinical bacteria in WWTPs, such as KPC-3-producing K. oxytoca, and, for the first time, a CTX-M-15-producing Ochromobactrum intermedium, a human opportunistic pathogen, and a SED-1-producing Citrobacter farmeri, an uncommon CTX-M-type extended-spectrum beta-lactamase.This work was supported by the European Union LIFE Programme under Grant Agreement LIFE14 ENV/PT/000739—LIFE Impetus (https://life-impetus.eu/), accessed on 1 February 2021.info:eu-repo/semantics/publishedVersio
Exploring the saccharomyces cerevisiae volatile metabolome: indigenous versus commercial strains
Winemaking is a highly industrialized process and a number of commercial Saccharomyces
cerevisiae strains are used around the world, neglecting the diversity of native yeast strains
that are responsible for the production of wines peculiar flavours. The aim of this study was
to in-depth establish the S. cerevisiae volatile metabolome and to assess inter-strains variability.
To fulfill this objective, two indigenous strains (BT2652 and BT2453 isolated from
spontaneous fermentation of grapes collected in Bairrada Appellation, Portugal) and two
commercial strains (CSc1 and CSc2) S. cerevisiae were analysed using a methodology
based on advanced multidimensional gas chromatography (HS-SPME/GCĂ—GC-ToFMS)
tandem with multivariate analysis. A total of 257 volatile metabolites were identified, distributed
over the chemical families of acetals, acids, alcohols, aldehydes, ketones, terpenic
compounds, esters, ethers, furan-type compounds, hydrocarbons, pyrans, pyrazines and
S-compounds. Some of these families are related with metabolic pathways of amino acid,
carbohydrate and fatty acid metabolism as well as mono and sesquiterpenic biosynthesis.
Principal Component Analysis (PCA) was used with a dataset comprising all variables (257
volatile components), and a distinction was observed between commercial and indigenous
strains, which suggests inter-strains variability. In a second step, a subset containing esters
and terpenic compounds (C10 and C15), metabolites of particular relevance to wine aroma,
was also analysed using PCA. The terpenic and ester profiles express the strains variability
and their potential contribution to the wine aromas, specially the BT2453, which produced
the higher terpenic content. This research contributes to understand the metabolic diversity
of indigenous wine microflora versus commercial strains and achieved knowledge that may
be further exploited to produce wines with peculiar aroma properties
West Nile virus transmission potential in Portugal
© The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.It is unclear whether West Nile virus (WNV) circulates endemically in Portugal. Despite the country's adequate climate for transmission, Portugal has only reported four human WNV infections so far. We performed a review of WNV-related data (1966-2020), explored mosquito (2016-2019) and land type distributions (1992-2019), and used climate data (1981-2019) to estimate WNV transmission suitability in Portugal. Serological and molecular evidence of WNV circulation from animals and vectors was largely restricted to the south. Land type and climate-driven transmission suitability distributions, but not the distribution of WNV-capable vectors, were compatible with the North-South divide present in serological and molecular evidence of WNV circulation. Our study offers a comprehensive, data-informed perspective and review on the past epidemiology, surveillance and climate-driven transmission suitability of WNV in Portugal, highlighting the south as a subregion of importance. Given the recent WNV outbreaks across Europe, our results support a timely change towards local, active surveillance.info:eu-repo/semantics/publishedVersio
The Combination of Gefitinib With ATRA and ATO Induces Myeloid Differentiation in Acute Promyelocytic Leukemia Resistant Cells
In approximately 15% of patients with acute myeloid leukemia (AML), total and phosphorylated EGFR proteins have been reported to be increased compared to healthy CD34(+) samples. However, it is unclear if this subset of patients would benefit from EGFR signaling pharmacological inhibition. Pre-clinical studies on AML cells provided evidence on the pro-differentiation benefits of EGFR inhibitors when combined with ATRA or ATO in vitro. Despite the success of ATRA and ATO in the treatment of patients with acute promyelocytic leukemia (APL), therapy-associated resistance is observed in 5-10% of the cases, pointing to a clear need for new therapeutic strategies for those patients. In this context, the functional role of EGFR tyrosine-kinase inhibitors has never been evaluated in APL. Here, we investigated the EGFR pathway in primary samples along with functional in vitro and in vivo studies using several APL models. We observed that total and phosphorylated EGFR (Tyr992) was expressed in 28% and 19% of blast cells from APL patients, respectively, but not in healthy CD34(+) samples. Interestingly, the expression of the EGF was lower in APL plasma samples than in healthy controls. The EGFR ligand AREG was detected in 29% of APL patients at diagnosis, but not in control samples. In vitro, treatment with the EGFR inhibitor gefitinib (ZD1839) reduced cell proliferation and survival of NB4 (ATRA-sensitive) and NB4-R2 (ATRA-resistant) cells. Moreover, the combination of gefitinib with ATRA and ATO promoted myeloid cell differentiation in ATRA- and ATO-resistant APL cells. In vivo, the combination of gefitinib and ATRA prolonged survival compared to gefitinib- or vehicle-treated leukemic mice in a syngeneic transplantation model, while the gain in survival did not reach statistical difference compared to treatment with ATRA alone. Our results suggest that gefitinib is a potential adjuvant agent that can mitigate ATRA and ATO resistance in APL cells. Therefore, our data indicate that repurposing FDA-approved tyrosine-kinase inhibitors could provide new perspectives into combination therapy to overcome drug resistance in APL patients
3D printed Poly(ε-caprolactone)/Hydroxyapatite scaffolds for bone tissue engineering: a comparative study on a composite preparation by melt blending or solvent casting techniques and the influence of bioceramic content on scaffold properties
Bone tissue engineering has been developed in the past decades, with the engineering of bone substitutes on the vanguard of this regenerative approach. Polycaprolactone-based scaffolds are fairly applied for bone regeneration, and several composites have been incorporated so as to improve the scaffolds’ mechanical properties and tissue in-growth. In this study, hydroxyapatite is incorporated on polycaprolactone-based scaffolds at two different proportions, 80:20 and 60:40. Scaffolds are produced with two different blending methods, solvent casting and melt blending. The prepared composites are 3D printed through an extrusion-based technique and further investigated with regard to their chemical, thermal, morphological, and mechanical characteristics. In vitro cyto-compatibility and osteogenic differentiation was also assessed with human dental pulp stem/stromal cells. The results show the melt-blending-derived scaffolds to present more promising mechanical properties, along with the incorporation of hydroxyapatite. The latter is also related to an increase in osteogenic activity and promotion. Overall, this study suggests polycaprolactone/hydroxyapatite scaffolds to be promising candidates for bone tissue engineering, particularly when produced by the MB method.info:eu-repo/semantics/publishedVersio
The choice of the spectral region in the use of spectroscopic and chemometric methods
A method is presented for the choice of spectral regions when absorption measurements are coupled to chemometric tools to perform quantitative analyses. The method is based on the spectral distribution of the relative standard deviation of concentration (s c/c). It has been applied to the development of PLS-FTNIR calibration models for the determination of density and MON of gasoline, and ethanol content and density of ethanol fuel. The new method was also compared with the correlation (R²) method and has proved to generate PLS calibration models that present better accuracy and precision than those based on R²
Exploring the correlations between epi indicators of COVID-19 and the concentration of pharmaceutical compounds in Wastewater Treatment Plants in Northern Portugal
The COVID-19 pandemic caused by the SARS-CoV-2 virus led to changes in the lifestyle and human behaviour, which resulted in different consumption patterns of some classes of pharmaceuticals including curative, symptom-relieving, and psychotropic drugs. The trends in the consumption of these compounds are related to their concentrations in wastewater systems, since incompletely metabolised drugs (or their metabolites back transformed into the parental form) may be detected and quantified by analytical methods. Pharmaceuticals are highly recalcitrant compounds and conventional activated sludge processes implemented in wastewater treatment plants (WWTP) are ineffective at degrading these substances. As a results, these compounds end up in waterways or accumulate in the sludge, being a serious concern given their potential effects on ecosystems and public health. Therefore, it is crucial to evaluate the presence of pharmaceuticals in water and sludge to assist in the search for more effective processes. In this work, eight pharmaceuticals from five therapeutic classes were analysed in wastewater and sludge samples collected in two WWTP located in the Northern Portugal, during the third COVID-19 epidemic wave in Portugal. The two WWTP demonstrated a similar pattern with respect to the concentration levels in that period. However, the drugs loads reaching each WWTP were dissimilar when normalising the concentrations to the inlet flow rate. Acetaminophen (ACET) was the compound detected at highest concentrations in aqueous samples of both WWTP (98. 516 g L1 in WWTP2 and 123. 506 g L1in WWTP1), indicating that this drug is extensively used without the need of a prescription, known of general public knowledge as an antipyretic and analgesic agent to treat pain and fever. The concentrations determined in the sludge samples were below 1.65 µg g1 in both WWTP, the highest value being found for azithromycin (AZT). This result may be justified by the physico-chemical characteristics of the compound that favour its adsorption to the sludge surface through ionic interactions. It was not possible to establish a clear relationship between the incidence of COVID-19 cases in the sewer catchment and the concentration of drugs detected in the same period. However, looking at the data obtained, the high incidence of COVID-19 in January 2021 is in line with the high concentration of drugs detected in the aqueous and sludge samples but prediction of drug load from viral load data was unfeasible.This study was supported by the Competitiveness and Internationalisation Operational Programme, Lisbon Regional Operational Programme and Algarve Regional Operational Programme with the support of FEDER, through the Incentive Scheme: research and development activities and investment in testing and optimisation (upscaling) infrastructures in the context of COVID-19, through the Project “SARS CONTROL: Evaluation of the impacts of SARS-CoV-2 on the urban water cycle and the downstream effects on Public Health" (Ref.
070076). Acknowledge is also due to the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020. Strategic funding from FCT to cE3c and BioISI Research Units (UIDB/00329/2020 and UIDB/04046/2020) and to the Associate Laboratory CHANGE (LA/P/0121/2020) is also gratefully acknowledged. ARS holds an FCT grant
SFRH/BD/131905/2017 and COVID/BD/151951/2021.ARLR and MFRP acknowledge the financial support from LA/P/0045/2020 (ALiCE), UIDB/50020/2020 and UIDP/50020/2020 (LSRE-LCM), funded by national funds through FCT/MCTES (PIDDAC). ARLR acknowledges FCT funding under DL57/2016 Transitory Norm Programme.info:eu-repo/semantics/publishedVersio
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