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1.
Artif Organs ; 2020 Jan 17.
Artículo en Inglés | MEDLINE | ID: mdl-31951029

RESUMEN

INTRODUCTION: Beta-trace protein (BTP), a low molecular weight protein of 23-29 kDa, has been proposed as a promising biomarker to estimate residual renal function (RRF) in patients on maintenance hemodialysis. Indeed, BTP is cleared by native kidney but not during conventional hemodialysis (HD) session. By contrast, the removal rate of BTP using convective processes (mainly hemodiafiltration (HDF)) and peritoneal dialysis (PD) has been little or not investigated. Therefore, an aim of this study was to evaluate the impact of dialysis procedures (high-flux HD (HD), on-line post-dilution HDF and PD) on BTP removal in comparison with beta-2 microglobulin (B2M) and Cystatin C (CYSC) removals after a single session. In addition, the ability of BTP to predict RRF in PD was assessed. PATIENTS AND METHODS: This observational cross-sectional study included a total of 82 stable chronic kidney disease patients, 53 patients were on maintenance dialysis (with n=26 in HD and n=27 in HDF) and 29 were on PD. Serum concentrations of BTP, B2M and CYSC were measured i) before and after a single dialysis session in HD and HDF anuric patients to calculate reduction percentages; ii) in serum, 24-hour-dialysate and 24-hour-urine in PD patients to compute total, peritoneal and urinary clearance. RRF was estimated using four equations developed for dialysis patients without urine collection and compared to the mean of the urea and creatinine clearances in PD. RESULTS: The concentrations of the three studied molecules were significantly reduced (p <0.001) after dialysis session with significantly higher reduction ratio using HDF compared to HD modality (p <0.001): BTP 49.3 vs 17.5%; B2M 82.3 vs 69.7%; CYSC 77.4 vs 66% in HDF and HD respectively. In non anuric PD patients, B2M and CYSC were partly removed by peritoneal clearance (72.3 and 57.6% for B2M and CYSC, respectively). By contrast, BTP removal by the peritoneum was negligible and a low bias for the BTP-based equation to estimate RRF (-1.4 mL/min/1.73m2 ) was calculated. CONCLUSION: BTP is significantly removed by high-flux HD or HDF, thereby compromising its use to estimate RRF. By contrast, BTP appears as a promising biomarker to estimate RRF in PD patients since it is not affected by peritoneal clearance, unlike B2M and CYSC, and it is well correlated to RRF.

2.
Estud. pesqui. psicol. (Impr.) ; 18(4): 1175-1194, out.-dez. 2019.
Artículo en Portugués | LILACS, Index Psicología - Revistas técnico-científicas | ID: biblio-994982

RESUMEN

Este artigo se propõe a analisar a situação da psicanálise nos cursos de psicologia das universidades do Rio de Janeiro, estabelecendo uma comparação com o caso de Buenos Aires. Para tal fim, utiliza um método de análise que implica construção documental, entrevistas e estudo teórico sobre a história e a atualidade da psicologia e da psicanálise nessas cidades. Entende-se que, além da chamada "crise" da psicanálise, ela mantém uma posição predominante nesses cursos. Espera-se que este trabalho contribua para uma discussão contextualizada dos cursos de psicologia em suas revisões curriculares.(AU)


We aim to analyse the situation of psychoanalysis in psychology undergraduate courses from universities of Rio de Janeiro, comparing these with the ones from Buenos Aires. For that purpose, we use a method of analysis that involves documental construction, interviews and theoretical study on the past history and the present reality of psychology and psychoanalysis in those cities. We understand that, besides the so-called "crisis" of psychoanalysis, this theoretical orientation maintains a predominant position in those courses. We expect that this work contributes to a contextualized discussion of psychology undergraduate courses and their curricular revisions.(AU)


Se propone analizar la situación del psicoanálisis en las carreras de psicología de universidades de Rio de Janeiro, estableciendo una comparación con el caso de Buenos Aires. Para tal fin, se utiliza un método de análisis que implica construcción documental, entrevista y estudio teórico, sobre la historia y actualidad de la psicología y el psicoanálisis en esas ciudades. Se entiende que, más allá de la llamada "crisis" del psicoanálisis, éste mantiene una posición predominante en esos cursos. Se espera que este trabajo contribuya a una discusión contextualizada de las carreras de Psicología y sus revisiones curriculares.(AU)


Asunto(s)
Humanos , Psicoanálisis , Psicología , Argentina , Universidades , Brasil
3.
Sci Rep ; 9(1): 17706, 2019 Nov 27.
Artículo en Inglés | MEDLINE | ID: mdl-31776434

RESUMEN

A valorization process of spent coffee grounds (SCG) was studied. Thus, a two-stage process, the first stage of polyphenols extraction and synthesis of a carbonaceous precursor and a subsequent stage of obtaining activated carbon (AC) by means of a carbonization process from the precursor of the previous stage, was performed. The extraction was carried out with a hydro-alcoholic solution in a pressure reactor, modifying time, temperature and different mixtures EtOH:H2O. To optimize the polyphenols extraction, a two-level factorial experimental design with three replicates at the central point was used. The best results were obtained by using a temperature of 80 °C during 30 min with a mixture of EtOH:H2O 50:50 (v/v). Caffeine and chlorogenic acid were the most abundant compounds in the analysed extracts, ranging from 0.09 to 4.8 mg∙g-1 and 0.06 to 9.7 mg∙g-1, respectively. Similarly, an experimental design was realized in order to analyze the influence of different variables in the AC obtained process (reaction time, temperature and KOH:precursor ratio). The best results were 1 h, 850 °C, and a mixture of 2.5:1. The obtained activated carbons exhibit a great specific surface (between 1600 m2∙g-1 and 2330 m2∙g-1) with a microporous surface. Finally, the adsorption capacity of the activated carbons was evaluated by methylene blue adsorption.

4.
Artículo en Inglés | MEDLINE | ID: mdl-31599372

RESUMEN

Biochar (BC) is a porous, carbonaceous material produced by slow pyrolysis of biomass under oxygen-limited conditions. BC production has been attracting research interest because it modifies soil physicochemical characteristics and improves the growth of plants in problem soils. These benefits may be best actualized for soils contaminated by metals, where remediation is hampered by metal toxicity to both plants and soil microbial communities. The objectives of this study were to evaluate the impact of the addition of chicken manure biochar (CMB), oat hull biochar (OHB), or pine bark biochar (PBB) on copper (Cu) bioavailability in a Cu-contaminated soil, the effectiveness of these BCs promoting plant growth, and its effects on soil microbial communities supporting these plants. A sandy soil (338 mg Cu kg-1) was amended with CMB, OHB, and PBB, and the metallophyte Oenothera picensis or the agricultural species Solanum lycopersicum and Lolium perenne were grown for 3 months. The BCs produced an increase in soil pH, reduced the exchangeable Cu, and increased Cu bound to organic matter and residual fractions. All BCs enhanced the quality of contaminated soil and increased the plant biomass production, notably for S. lycopersicum, which grew until 12 times more than plants in non-amended soil. While BC addition reduced the concentration of Cu in soil pore water, the amendment did not reduce the concentrations of Cu in shoot tissues. BC additions also stimulated soil microorganisms, increasing basal respiration and DHA activity and modifying microbial communities, especially in soils supporting L. perenne. These results indicate that BCs represent an effective tool to remediate Cu-contaminated sandy soils.

5.
Waste Manag ; 96: 15-24, 2019 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-31376959

RESUMEN

A solid-liquid extraction method using ethanol-water mixtures was combined with cLC-DAD, LC-MS/MS and chemometric analyses for establishing the optimum extraction conditions of valuable polyphenols from spent coffee grounds. Chlorogenic and p-coumaric acids were the most abundant polyphenols found, ranging from 0.02 to 4.8 mg g-1 and 0.173-0.50 mg g-1, respectively. In addition, total polyphenol content (9-29 mg GAE g-1 DW), total flavonoid content (11-27 mg QE g-1 DW), total antioxidant activity (0.3-7 mg GAE g-1 DW) and free radical scavenging ability (DPPH assay, 64-927 µg extract g-1 at EC50) of obtained extracts were determined. Response surface methodology allowed obtaining predictive models for the extraction of each individual polyphenol. On the other hand, multifactorial ANOVA was used to establish differences between coffee and spent coffee ground extracts. Principal component analysis was also employed to relate antioxidant activities, total polyphenol and total flavonoid contents with both the polyphenols extracted and the residue coffee type. The overall results suggested that spent coffee grounds could be reused as a promising, inexpensive and natural source of bioactive polyphenols with potential industrial applications, thus minimizing the waste disposal and environmental impact.


Asunto(s)
Café , Polifenoles , Antioxidantes , Cromatografía Liquida , Espectrometría de Masas en Tándem
6.
Anal Chim Acta ; 1081: 72-80, 2019 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-31446967

RESUMEN

A new calibration method based on the use of headspace solid-phase microextraction (HS-SPME) and in-fiber internal standardization, combined with gas chromatography coupled to mass spectrometry (GC/MS) was developed for quantifying Se volatile organic species released by plants exposed to chitosan-modified selenium nanoparticles (Cs-SeNPs). The effect of several parameters affecting extraction and separation of the selected organic species of selenium (dimethylselenium (DMSe), diethylselenium (DESe) and dimethyldiselenium (DMDSe)) and deuterated dimethyl sulphide (d6-DMS) employed as internal standard were studied and optimized using an experimental design. The developed methodology was applied for quantifying the volatile selenium compounds produced over time by the plant species Raphanus sativus and Brassica juncea grown in hydroponic solution containing 5 mg Se L-1 in the form Cs-SeNPs. The procedure employed consisted in two steps. Volatile selenium species released from the plants were first extracted in the SPME fiber located at the headspace of a box with a fixed volume. Subsequently, the internal standard placed in a vial subjected to the same conditions as plants was extracted on the same fiber than the one previously used for extracting selenium compounds. Finally the extracted compounds were separated and analyzed by GC/MS. Results evidenced Cs-SeNPs biotransformation into DMSe and DMDSe by both plants species during growing stage, in amounts of the order of ng. Additionally, the resulting data were submitted to multifactorial ANOVA to evaluate the influence of plant type and time of exposure to Cs-SeNPs on the production of volatile selenium compounds.

7.
Food Chem ; 295: 289-299, 2019 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-31174761

RESUMEN

A method combining solid-liquid extraction based on ethanolic aqueous solution, cLC-DAD and chemometrics, was performed to extract and quantify polyphenols from citrus peels. LC-MS/MS was also employed for chemical profiling. The effect of extraction variables on the recovery was examined by experimental factorial design. Data were evaluated using multifactorial-ANOVA, response surface analysis and Principal Component Analysis. trans-Ferulic and p-coumaric antioxidants were found in lower quantities (<1.4 mg·g-1) in all peel extracts. Narangin flavonoid was also identified in all samples, while rutin flavonol was determined in the concentration range of 3.3-4.7 mg·g-1. The most abundant polyphenol in the extracts obtained from all evaluated citrus samples was the flavanone hesperidin (280-673 mg·g-1). Furthermore, peel extracts were evaluated in terms of total polyphenol and flavonoid content, total antioxidant activity and DPPH free radical scavenging. The obtained results suggested that evaluated citrus peel by-products could be reused as a source of polyphenols and transformed into value-added products.


Asunto(s)
Citrus/química , Polifenoles/análisis , Polifenoles/aislamiento & purificación , Residuos/análisis , Análisis de Varianza , Antioxidantes/análisis , Antioxidantes/aislamiento & purificación , Cromatografía Liquida , Flavonoides/análisis , Flavonoides/aislamiento & purificación , Hesperidina/análisis , Hesperidina/aislamiento & purificación , Extractos Vegetales/análisis , Extractos Vegetales/química , Análisis de Componente Principal , Espectrometría de Masas en Tándem
8.
J Chromatogr A ; 1601: 255-265, 2019 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-31103200

RESUMEN

A simple and efficient low-cost matrix solid-phase dispersion (MSPD) extraction based on TiO2 nanoparticles (NPs) and diatomaceous earth has been developed for the recovery of phenolic compounds from residual brewing yeast. Experimental conditions for MSPD extraction were optimized by an experimental design approach. A screening factorial design plus replicates at the center point, followed by surface response analysis were used. The simultaneous identification and quantification of eleven main natural polyphenols: caffeic, chlorogenic, p-coumaric, 3,4-dihydroxibenzoic, trans-ferulic and gallic acids, kaempferol, myricetin, naringin, quercetin and rutin, was possible by combining MSPD and capillary liquid chromatography couple to a diode array detection system (cLC-DAD) and liquid chromatography couple to a triple quadrupole analyzer (LC-MS/MS). Moreover, residual brewing yeast extracts were evaluated in terms of DPPH (1,1-diphenyl-2 picrylhydrazyl) free radical scavenging activity. Polyphenol-nanoparticle interaction was studied by UV-vis spectroscopy and electron transmission microscopy (TEM), pointing out a stable interplay that assists phenolic isolation. The extracted polyphenol quantities were within the 3.2-1,500 µg g-1 range, and the high antioxidant activity estimated suggested that developed MSPD is a successful, simple, efficient and rapid method for the extraction and recovery of bioactive phenolic compounds, which promotes the reuse and re-evaluation of brewing yeast agri-food by-products.


Asunto(s)
Técnicas de Química Analítica/métodos , Nanopartículas/química , Fenoles/análisis , Saccharomyces cerevisiae/química , Extracción en Fase Sólida , Titanio/química , Antioxidantes/química , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Tierra de Diatomeas/química , Fenoles/aislamiento & purificación , Polifenoles/análisis , Polifenoles/química , Quercetina/análisis , Espectrometría de Masas en Tándem
9.
J Environ Manage ; 242: 171-177, 2019 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-31035179

RESUMEN

The immobilization of Candida rugosa lipase (CRL) onto biochar was studied in a series of batch experiments. CRL sorption behavior was evaluated as a function of pH, enzyme concentration, temperature and ionic strength. As the immobilized lipase was used for the catalytic esterification of oleic acid, its resistance to solvents and thermal stability were evaluated. CRL adsorption increased by increasing temperature, and with higher pH, reaching a maximum at pH 7.0. Immobilization increased lipase stability at 40 °C by more than 80% when compared to the free enzyme. Moreover, immobilized CRL showed high stability in the presence of tert-butanol, which prevents premature deactivation of the enzyme caused by alcohols during the reaction. Immobilization of CRL increased the oleic acid conversion rate. Our results suggest that biochar is a highly promising material for the immobilization of CRL lipase for the catalytic production of esters.


Asunto(s)
Lipasa , Ácido Oléico , Biocatálisis , Candida , Carbón Orgánico , Estabilidad de Enzimas , Enzimas Inmovilizadas , Esterificación
10.
Talanta ; 188: 393-403, 2018 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-30029393

RESUMEN

The combination of UV-vis spectrophotometry with a chemometric calibration tool based on partial least squares (PLS) has allowed us the development of a multivariate analytical method that simultaneously estimates the concentration and size of mixtures of silver nanoparticles (AgNPs) in environmental water samples. The method is based on changes in the surface plasmon resonance band (SPRB) of AgNPs when they form aggregated/assembled structures with L-cysteine (L-cys). Measurementts were performed by employed a fixed-time kinetics method that implies that the final spectra (response) are obtained by subtstracting the solutions spectra at fixed times. Optimization of experimental conditions affecting aggregation such as time, temperature, pH and concentration of aggregating substance was performed by experimental design and response surface methodologies (RSM). A multivariate calibration model using AgNPs of known diameter size ((20 ±â€¯3), (41 ±â€¯3), (59 ±â€¯5) and (79 ±â€¯7) nm) within a concentration range between 0.62 and 2.5 mg L-1 was constructed by using a mixture experimental design and PLS. The method was finally applied to estimate size and concentration of AgNPs in AgNPs-spiked river and tap water samples. Water samples were spiked with individual, binary and ternary mixtures of AgNPs of different sizes and by using two types of AgNPs: citrate-coated AgNPs (cit-AgNPs) and polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs). A good correspondence was obtained between predicted values and the total amount of AgNPs added with recovery values ranged within 80-160% for the individual mixtures, 68-108% for the binary mixtures and 60-64% for the ternary mixtures of AgNPs. Finally, transmission electron microscopy (TEM) measurements were performed for those cases where discrepancies between the expected and the obtained values were observed. TEM micrographs evidenced the presence of agglomerates or aggregates of AgNPs in some of the mixtures or water tested.

11.
Food Chem ; 267: 246-254, 2018 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-29934164

RESUMEN

A method combining aqueous extraction, reversed-phase high-performance capillary liquid chromatography with photodiode array detection (cLC-DAD) and chemometric tools, was developed to determine phenolic compounds in residual brewing yeast. The effect of temperature, nature of extraction solvent and method for separation of extract solution were studied to optimize the extraction conditions on the basis of total phenolic content (TPC), total flavonoids content (TFC) and antioxidant capacity. Polyphenols were determined by cLC-DAD. Flavonols as rutin and kaempferol, flavonoids as naringin, phenolic acids as gallic acid and antioxidants as trans-ferulic and p-coumaric acids were found and quantified in the brewing residue. Data were subjected to evaluation using multifactor ANOVA and principal component analysis (PCA), both showing that lyophilization pretreatment affects the content of individual polyphenols and that residual brewing yeast contains higher polyphenol amounts than the liquid beer waste. The obtained results suggest that residual brewing yeast could be a source of polyphenols.


Asunto(s)
Cromatografía Líquida de Alta Presión , Polifenoles/análisis , Saccharomyces cerevisiae/metabolismo , Antioxidantes/química , Cromatografía de Fase Inversa , Flavonoides/análisis , Flavonoides/química , Humedad , Concentración de Iones de Hidrógeno , Polifenoles/química , Análisis de Componente Principal , Saccharomyces cerevisiae/crecimiento & desarrollo
12.
Sci Total Environ ; 616-617: 960-969, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29096960

RESUMEN

Biochar (BC) is gaining attention as a soil amendment that can remediate metal polluted soils. The simultaneous effects of BC on copper (Cu) mobility, microbial activities in soil using metallophytes have scarcely been addressed. The objective of this study was to evaluate the effects of biochar BCs on Cu immobilization and over soil microbial communities in a Cu-contaminated soil evaluated over a two-year trial. A Cu-contaminated soil (338mgkg-1) was incubated with chicken manure biochar (CMB) or oat hull biochar (OHB) at rates of 1 and 5% w/w. Metallophyte Oenothera picensis was grown over one season (six months). The above process was repeated for 3 more consecutive seasons using the same soils. The BCs increased the soil pH and decreased the Cu exchangeable fraction Cu by 5 and 10 times (for OHB and CMB, respectively) by increasing the Cu bound in organic matter and residual fractions, and its effects were consistent across all seasons evaluated. BCs provided favorable habitat for microorganisms that was evident in increased microbial activity. The DHA activity was increased in all BC treatments, reaching a maximum of 7 and 6 times higher than control soils in CMB and OHB. Similar results were observed in microbial respiration, which increased 53% in OHB and 61% in CMB with respect to control. The BCs produced changes in microbial communities in all seasons evaluated. The fungal and bacterial richness were increased by CMB and OHB treatments; however, no clear effects were observed in the microbial diversity estimators. The physiochemical and microbiological effects produced by BC result in an increase of plant biomass production, which was on average 3 times higher than control treatments. However, despite being a metallophyte, O. picensis did not uptake Cu efficiently. Root and shoot Cu concentrations decreased or changed insignificantly in most BC treatments.


Asunto(s)
Carbón Orgánico/química , Cobre/análisis , Microbiología del Suelo , Contaminantes del Suelo/análisis , Suelo/química , Bacterias/metabolismo , Cobre/química , Contaminación Ambiental/estadística & datos numéricos , Hongos/metabolismo , Contaminantes del Suelo/química
13.
Environ Sci Pollut Res Int ; 24(16): 14104-14116, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28417325

RESUMEN

We characterized humic substances (HS) extracted from a Cu-contaminated soil without compost addition (C) or amended with a wheat straw-based compost (WSC) (H1), co-composted with Fe2O3 (H2), or co-composted with an allophane-rich soil (H3). Extracted HS were characterized under electron microscopy (SEM/TEM), energy-dispersive X-ray (X-EDS), and Fourier transform infrared (FTIR) spectroscopy. In addition, HS extracted from WSC (H4) were characterized at pH 4.0 and 8.0 with descriptive purposes. At pH 4.0, globular structures of H4 were observed, some of them aggregating within a large network. Contrariwise, at pH 8.0, long tubular and disaggregated structures prevailed. TEM microscopy suggests organo-mineral interactions at scales of 1 to 200 nm with iron oxide nanoparticles. HS extracted from soil-compost incubations showed interactions at nanoscale with minerals and crystal compounds into the organic matrix of HS. Bands associated to acidic functional groups of HS may suggest potential sorption interactions with transition metals. We conclude that metal ions and pH have an important role controlling the morphology and configuration of HS from WSC. Characterization of H4 extracted from WSC showed that physicochemical protection of HS could be present in composting systems treated with inorganic materials. Finally, the humified fractions obtained from compost-amended soils may have an important effect on metal-retention, supporting their potential use in metal-contaminated soils.


Asunto(s)
Cobre/química , Sustancias Húmicas , Contaminantes del Suelo/química , Compostaje , Compuestos Férricos , Suelo
14.
Int J Mol Sci ; 18(1)2017 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-28075409

RESUMEN

The human immunodeficiency virus type 1 (HIV-1) Vpr protein is an attractive target for antiretroviral drug development. The conservation both of the structure along virus evolution and the amino acid sequence in viral isolates from patients underlines the importance of Vpr for the establishment and progression of HIV-1 disease. While its contribution to virus replication in dividing and non-dividing cells and to the pathogenesis of HIV-1 in many different cell types, both extracellular and intracellular forms, have been extensively studied, its precise mechanism of action nevertheless remains enigmatic. The present review discusses how the apparently multifaceted interplay between Vpr and host cells may be due to the impairment of basic metabolic pathways. Vpr protein modifies host cell energy metabolism, oxidative status, and proteasome function, all of which are likely conditioned by the concentration and multimerization of the protein. The characterization of Vpr domains along with new laboratory tools for the assessment of their function has become increasingly relevant in recent years. With these advances, it is conceivable that drug discovery efforts involving Vpr-targeted antiretrovirals will experience substantial growth in the coming years.


Asunto(s)
Fármacos Anti-VIH/farmacología , Infecciones por VIH/etiología , VIH-1/efectos de los fármacos , Productos del Gen vpr del Virus de la Inmunodeficiencia Humana/antagonistas & inhibidores , Animales , Fármacos Anti-VIH/uso terapéutico , Proteínas Portadoras/metabolismo , Secuencia Conservada , Progresión de la Enfermedad , Descubrimiento de Drogas , Evolución Molecular , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/metabolismo , VIH-1/fisiología , Humanos , Lentivirus de los Primates/genética , Unión Proteica , Replicación Viral , Productos del Gen vpr del Virus de la Inmunodeficiencia Humana/química , Productos del Gen vpr del Virus de la Inmunodeficiencia Humana/metabolismo
15.
Virus Res ; 213: 116-123, 2016 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-26597719

RESUMEN

The human immunodeficiency virus type 1 (HIV-1) encodes for accessory viral protein R (Vpr), which arrests the cell cycle of host cells at G2 and causes mitochondrial dysfunction and alterations in glycolysis. High-level expression of Vpr protein correlates with increased viral production and disease progression. Vpr causes structural and functional injury in many types of eukaryotic cells, whether or not they are permissive for viral replication; among them is the budding yeast Saccharomyces cerevisiae. We hypothesized that the dramatic Vpr-induced injuries in yeast could be prevented by strengthening their redox response capacity. We show that exogenous addition of glutathione (GSH) or its prodrug, N-acetylcysteine (NAC), protected budding yeasts from Vpr-induced cytopathic effects. Moreover, addition of adenosine triphosphate (ATP) to growing cultures of Vpr-producing yeast returned cellular growth to control levels, whereas the addition dehydroascorbic acid (DHA) had only a minor protective effect. The diminished protein levels of Cox2p and Cox4p in wild typeVpr-producing yeasts together with the acute sensitivity of petite yeasts to Vpr activity may have been caused by low intracellular ATP levels. As a consequence of this energy deficit, eukaryotic cells would be unable to synthetize adequate supplies of GSH or to signal the mitochondrial retrograde response. Our findings strongly suggest that the cytopathogenic effect of Vpr protein in eukaryotic cells can be prevented by increasing intracellular antioxidant stores or, alternatively, supplying external ATP. Furthermore, these results support a potentially promising future for S. cerevisiae expression as a modality to search for Vpr-targeted inhibitors.


Asunto(s)
Glutatión/metabolismo , Estrés Oxidativo , Saccharomycetales/fisiología , Productos del Gen vpr del Virus de la Inmunodeficiencia Humana/metabolismo , Adenosina Trifosfato/metabolismo , Saccharomycetales/genética , Saccharomycetales/crecimiento & desarrollo
16.
Cell Tissue Bank ; 17(1): 137-45, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26220398

RESUMEN

Mobilized peripheral blood (MPB) bone marrow cells possess the potential to differentiate into a variety of mesenchymal tissue types and offer a source of easy access for obtaining stem cells for the development of experimental models with applications in tissue engineering. In the present work, we aimed to isolate by magnetic activated cell sorting CD90+ cells from MPB by means of the administration of Granulocyte-Colony Stimulating Factor and to evaluate cell proliferation capacity, after thawing of the in vitro culture of this population of mesenchymal stem cells (MSCs) in sheep. We obtained a median of 8.2 ± 0.6 million of CD90+ cells from the 20-mL MPB sample. After thawing, at day 15 under in vitro culture, the mean CD90+ cells determined by flow cytometry was 92.92 ± 1.29 % and cell duplication time determined by crystal violet staining was 47.59 h. This study describes for the first time the isolation, characterization, and post-in vitro culture thawing of CD90+ MSCs from mobilized peripheral blood in sheep. This population can be considered as a source of MSCs for experimental models in tissue engineering research.


Asunto(s)
Criopreservación/métodos , Células Madre Mesenquimatosas/citología , Células Madre de Sangre Periférica/citología , Antígenos Thy-1/metabolismo , Animales , Diferenciación Celular , Proliferación Celular , Separación Celular , Forma de la Célula , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Inmunofenotipificación , Masculino , Ovinos
17.
Viruses ; 7(8): 4352-68, 2015 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-26247957

RESUMEN

Viral protein U (Vpu) is a lentiviral viroporin encoded by human immunodeficiency virus type 1 (HIV-1) and some simian immunodeficiency virus (SIV) strains. This small protein of 81 amino acids contains a single transmembrane domain that allows for supramolecular organization via homoligomerization or interaction with other proteins. The topology and trafficking of Vpu through subcellular compartments result in pleiotropic effects in host cells. Notwithstanding the high variability of its amino acid sequence, the functionality of Vpu is well conserved in pandemic virus isolates. This review outlines our current knowledge on the interactions of Vpu with the host cell. The regulation of cellular physiology by Vpu and the validity of this viroporin as a therapeutic target are also discussed.


Asunto(s)
Antígenos CD4/biosíntesis , VIH-1/fisiología , Interacciones Huésped-Patógeno , Proteínas del Virus de la Inmunodeficiencia Humana/metabolismo , Multimerización de Proteína , Proteínas Reguladoras y Accesorias Virales/metabolismo , Liberación del Virus , Regulación hacia Abajo , Humanos , Unión Proteica , Transporte de Proteínas
18.
Biomed Chromatogr ; 28(1): 59-83, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23982862

RESUMEN

Separation of enantiomers remains a challenge owing to their identical physical and chemical properties in an achiral environment, and research on specialized separation techniques such as multidimensional achiral-chiral liquid chromatography continues to resolve individual enantiomers in complex samples. Recent advances in application of multidimensional liquid chromatography applied to chiral analysis are reviewed. For this reason, benefits of achiral-chiral coupling are shown, with emphasis in applications on biological and pharmaceutical fields as well as pesticide analysis. A description of standard instrumental setup in both heart-cut and comprehensive multidimensional liquid chromatography is shown. The most broadly used chiral stationary phases for multidimensional liquid chromatography are summarized. An extensive overview of different interface designs applied to complex samples is presented.


Asunto(s)
Cromatografía Liquida/métodos , Plaguicidas/aislamiento & purificación , Preparaciones Farmacéuticas/aislamiento & purificación , Cromatografía Liquida/instrumentación , Plaguicidas/química , Preparaciones Farmacéuticas/química , Estereoisomerismo
19.
Biomed Chromatogr ; 27(11): 1413-22, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23703259

RESUMEN

A direct chiral LC-UV method was optimized for the determination of salbutamol (SAL) ß2 -agonist in environmental water. Two commercially available columns were evaluated: teicoplanin Chirobiotic-T™ (150 × 2.1 mm i.d., 5 µm) and vancomycin Chirobiotic-V™ (150 × 2.1 mm i.d., 5 µm). Finally, teicoplanin chiral stationary phase was selected for SAL enantiomer resolution. In order to preserve its integrity and maintain the column performance for longer time, the use of additives such as triethylamine (TEA) in the mobile phase was avoided. Experimental design was applied to simultaneously evaluate the influence of several parameters involved in enantiomer separation and to establish the conditions for acceptable resolution and performance in short analysis time. Optimum mobile phase was methanol-20 mM ammonium acetate buffer at pH 4.5 (98:2, v/v). A solid-phase extraction procedure for sample pre-concentration and clean-up allowed the determination of chiral SAL residues in natural water samples spiked at low concentrations in the range 1.0-20 ng mL(-1) . Reproducible recoveries, between 77 and 98%, were obtained and matrix effect was negligible. Injection of sample solutions at low elution strength permitted the SAL enantioresolution in the natural water complex matrix with satisfactory sensitivity and precision.


Asunto(s)
Agonistas de Receptores Adrenérgicos beta 2/análisis , Albuterol/análisis , Cromatografía Líquida de Alta Presión/métodos , Cromatografía de Fase Inversa/métodos , Agua Dulce/análisis , Teicoplanina/química , Contaminantes Químicos del Agua/análisis , Límite de Detección , Estereoisomerismo
20.
Biochemistry ; 52(1): 171-7, 2013 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-23240720

RESUMEN

Human immunodeficiency virus type 1 (HIV-1) Vpu is an integral membrane protein that belongs to the viroporin family. Viroporins interact with cell membranes, triggering membrane permeabilization and promoting release of viral particles. In vitro electrophysiological methods have revealed changes in membrane ion currents when Vpu is present; however, in vivo the molecular mechanism of Vpu at the plasma membrane is still uncertain. We used the yeast Saccharomyces cerevisiae as a genetic model system to analyze how Vpu ion channel impacts cellular homeostasis. Inducible expression of Vpu impaired cell growth, suggesting that this viral protein is toxic to yeast cultures. This toxicity decreased with extracellular acidic pH. Also, Vpu toxicity diminished as the extracellular K(+) concentration was increased. However, expression of the Vpu protein suppresses the growth defect of K(+) uptake-deficient yeast (Δtrk1,2). The phenotype rescue of these highly hyperpolarized cells was almost total when they were grown in medium supplemented with high concentrations of KCl (100 mM) at pH 7.0 but was significantly reduced when the extracellular K(+) concentration or pH was decreased. These results indicate that Vpu has the ability to modify K(+) transport in both yeast strains. Here, we show also that Vpu confers tolerance to the aminoglycoside antibiotic hygromycin B in Δtrk1,2 yeast. Our results suggest that Vpu interferes with cell growth of wild-type yeast but improves proliferation of the hyperpolarized trk1,2 mutant by inducing plasma membrane depolarization. Furthermore, evaluation of the ion channel activity of the Vpu protein in Δtrk1,2 yeast could aid in the development of a high-throughput screening assay for molecules that target the retroviral protein.


Asunto(s)
VIH-1/fisiología , Interacciones Huésped-Patógeno , Proteínas del Virus de la Inmunodeficiencia Humana/metabolismo , Potasio/metabolismo , Saccharomyces cerevisiae/virología , Proteínas Reguladoras y Accesorias Virales/metabolismo , Transporte Biológico , Expresión Génica , Infecciones por VIH/metabolismo , Infecciones por VIH/virología , Proteínas del Virus de la Inmunodeficiencia Humana/genética , Humanos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas Reguladoras y Accesorias Virales/genética
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