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1.
Nucleic Acids Res ; 50(5): 2549-2565, 2022 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-35188579

RESUMO

The Isw1b chromatin-remodeling complex is specifically recruited to gene bodies to help retain pre-existing histones during transcription by RNA polymerase II. Recruitment is dependent on H3K36 methylation and the Isw1b subunit Ioc4, which contains an N-terminal PWWP domain. Here, we present the crystal structure of the Ioc4-PWWP domain, including a detailed functional characterization of the domain on its own as well as in the context of full-length Ioc4 and the Isw1b remodeler. The Ioc4-PWWP domain preferentially binds H3K36me3-containing nucleosomes. Its ability to bind DNA is required for nucleosome binding. It is also furthered by the unique insertion motif present in Ioc4-PWWP. The ability to bind H3K36me3 and DNA promotes the interaction of full-length Ioc4 with nucleosomes in vitro and they are necessary for its recruitment to gene bodies in vivo. Furthermore, a fully functional Ioc4-PWWP domain promotes efficient remodeling by Isw1b and the maintenance of ordered chromatin in vivo, thereby preventing the production of non-coding RNAs.


Assuntos
Montagem e Desmontagem da Cromatina , Código das Histonas , Cromatina , DNA/química , Metilação , Nucleossomos/genética , Ligação Proteica
2.
Educ Inf Technol (Dordr) ; : 1-18, 2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37361734

RESUMO

Whilst the use of various blended learning models preceded the COVID-19 pandemic, the abrupt shift to remote delivery served as catalyst within the sector in enhancing digital solutions to meet immediate student needs. As we emerge from the pandemic, a return to purely didactic and impersonal in-person teaching seems anticlimactic, with the return to the lecture theatre seeing many lecturers trialling various digital tools in creating more interactive in-person, synchronous, and asynchronous sessions. In evaluating students' experiences of the various tools and approaches applied by academic staff, a survey was developed by a multidisciplinary team of educators at Cardiff University's School of Medicine exploring student perceptions of e-learning resources (ELRs), as well as student experiences of various blended learning approaches. The primary aim of this study was to evaluate student experience, satisfaction, and engagement with ELRs and blended learning. A total of 179 students (undergraduate and postgraduate) completed the survey. 97% confirmed that e-learning resources were blended within the teaching they received, with 77% rating the quality of e-learning as good-to-excellent and 66% reporting a preference for asynchronous resources that enable them to learn at their own pace. A variety of platforms, tools, and approaches were identified by students as meeting their diverse learning needs. We therefore propose a personalised, evidence-based and inclusive learning (PEBIL) model enabling the application of digital technologies both on and offline.

3.
Int J Mol Sci ; 23(22)2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36430606

RESUMO

Actinidia arguta (Siebold & Zucc.) Planch. ex Miq. (kiwiberry) leaves are a source of phenolic compounds with pro-health biological effects, such as antioxidant and anti-inflammatory activities. Despite the huge number of studies reporting the composition of A. arguta leaves, no in vitro or in vivo studies explore its potential use as nutraceutical ingredient based on these activities. Therefore, this study aims to characterize the safety profile of kiwiberry leaf extracts using in vitro and in vivo approaches through the assessment of intestinal cell viability (Caco-2 and HT29-MTX), 3D intestinal permeation, and, most important, the redox markers, biochemical profile and liver and kidney function effects after the animal assays. Briefly, wistar rats were orally treated for 7 days with kiwiberry leaf extracts (50 and 75 mg/kg bw), water (negative control), or vitamin C (positive control). The cell viability was above 90% at 1000 µg/mL for both cells. Coumaroyl quinic acid and rutin achieved a permeation higher than 25% in the 3D intestinal model. The animal studies confirmed the extracts' ability to increase superoxide dismutase, glutathione peroxidase, and catalase content in animals' livers and kidneys while simultaneously decreasing the triglycerides content. This study highlighted the antioxidant capacity of kiwiberry leaf extracts, ensuring their efficacy and safety as a nutraceutical ingredient.


Assuntos
Antioxidantes , Extratos Vegetais , Ratos , Animais , Humanos , Antioxidantes/farmacologia , Antioxidantes/química , Células CACO-2 , Extratos Vegetais/química , Suplementos Nutricionais , Permeabilidade
4.
Bioorg Med Chem Lett ; 30(13): 127219, 2020 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-32360103

RESUMO

The ability to track drugs inside of cells and tumours has been highly valuable in cancer research and diagnosis. Metal complexes add attractive features to fluorescent drugs, such as targeting and specificity, solubility and uptake or photophysical properties. This review focuses on the latest fluorescent metal-based complexes, their cellular targets, photophysical properties and possible anticancer effects.


Assuntos
Antineoplásicos/uso terapêutico , Complexos de Coordenação/uso terapêutico , Corantes Fluorescentes/uso terapêutico , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/efeitos da radiação , Linhagem Celular Tumoral , Complexos de Coordenação/efeitos da radiação , Corantes Fluorescentes/efeitos da radiação , Humanos , Luz , Metais Pesados/química , Metais Pesados/efeitos da radiação
5.
An Acad Bras Cienc ; 92(suppl 1): e20181313, 2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32756841

RESUMO

Quinoa, classified as a pseudocereal, presents greater nutritional value compared to traditional cereals. Considering the potential for cultivation presented by the species and the benefits of studying plant morphology and morphobiometry, this paper describes seed and seedling morphobiometric characteristics of quinoa (Chenopodium quinoa Willd.) cultivar BRS Piabiru during germination and emergence. To evaluate seed morphobiometry the 1000-seeds weight, moisture content, seed morphological characterization and the tetrazolium test were performed. The morphological characterization of germination and seedling emergence were performed by periodic observations during the development, allowing the description using pictures and drawings. Quinoa seeds cv. BRS Piabiru present an average diameter of 2.05 mm and 1.07 width. 1000-seeds weight of 2.68 g and moisture content of 11%. Externally, quinoa seeds present the pericarp as testa, the hilum and the raphe and, internally, the embryonic axis (cotyledons, radicle and hypocotyl-radicle), perisperm and endosperm. The germination is characterized as epigeal, phanerocotylar type, with radicle protrusion at 3 hours after sowing and complete formed seedlings at 24 hours after sowing. Emergence occurs at 9 days after sowing and plants are completely formed at 12 days after sowing.


Assuntos
Chenopodium quinoa , Germinação , Valor Nutritivo , Plântula , Sementes
6.
Drug Dev Ind Pharm ; 46(2): 236-245, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31928345

RESUMO

Nanoparticles based on gellan gum/pectin blends were designed for colon-targeted release of resveratrol (RES). Their impact on drug release rates and permeability were evaluated using Caco-2 cell model and mucus secreting triple co-culture model. Polymeric nanoparticles (PNP) were successfully prepared by nebulization/ionotropic gelation, achieving high drug loading (>80%). PNP were spherical with a low positive charge density (+5mV) and exhibited diameters of around 330 nm. Developed PNP were able to promote effective modulation of drug release rates, so that only 3% of RES was released in acidic media over 2 h, and, in pH 6.8, the drug was released in a sustained manner, reaching 85% in 30 h. The permeability of RES-loaded PNP in the Caco-2 model was 0.15%, while in the triple co-culture model, in the presence of mucus, it reached 5.5%. The everted gut sac experiment corroborated the low permeability of RES-loaded PNP in the presence or absence of mucus and highlighted their high ability to interact with the intestinal tissue. Results indicate that the novel PNP developed in this work are safe and promising carriers for controlled delivery of RES at the colon.


Assuntos
Colo/efeitos dos fármacos , Nanopartículas/administração & dosagem , Nanopartículas/química , Pectinas/química , Polissacarídeos Bacterianos/química , Resveratrol/administração & dosagem , Resveratrol/química , Administração Oral , Animais , Células CACO-2 , Linhagem Celular Tumoral , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Células HT29 , Humanos , Concentração de Íons de Hidrogênio , Mucosa Intestinal/metabolismo , Masculino , Muco/metabolismo , Tamanho da Partícula , Permeabilidade/efeitos dos fármacos , Ratos , Ratos Wistar
7.
Chemistry ; 25(37): 8713-8718, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31081563

RESUMO

Water and glycerol permeation through human AQP3 are described by exploiting advanced metadynamics approaches, which enabled both to explore the free energies involved in pore permeation and to achieve a description of the mechanisms with an atomistic level of detail.

8.
Inorg Chem ; 58(3): 2140-2148, 2019 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-30645101

RESUMO

Following our recent reports on the inhibition of the water and glycerol channel aquaglyceroporin-3 (AQP3) by the coordination complex [AuIII(1,10-phenanthroline)Cl2] (Auphen), a series of six new Au(III) complexes featuring substituted 1,10-phenanthroline ligands (1-6) have been synthesized and characterized. The speciation of the compounds studied in buffered solution by UV-visible spectrophotometry showed that most of the complexes remain stable for several hours. Quantum mechanics (QM) studies of the hydrolysis processes of the compounds suggest that they are thermodynamically less prone to exchange the chlorido ligands with H2O or OH- in comparison to Au(III) bipyridyl complexes. Preliminary data on the antiproliferative activity against A549 human lung cancer cells indicate that the compounds are able to inhibit cell proliferation in vitro. Stopped-flow spectroscopy showed that these complexes potently inhibit glycerol permeation in human red blood cells (hRBC) through AQP3 blockage. The QM investigation of the ligand exchange with methanethiol, used as a model of Cys40 of AQP3, was carried out for some derivatives and showed that the affinity of the compounds' binding for thiols is higher in comparison to the Aubipy complex ([AuIII(bipy)Cl2]PF6, bipy = 2,2'-bipyridine). In addition, both noncovalent and coordinative binding of complex 3 ( [AuIII(5-chloro-1,10-phenanthroline)Cl2]PF6) to the protein channel has been investigated in comparison to the benchmark Auphen and Aubipy using a computational workflow, including QM, molecular dynamics (MD), and quantum mechanics/molecular mechanics (QM/MM) approaches. Finally, atoms in molecules (AIM) and natural bond orbital (NBO) analyses corroborate the MD predictions, providing quantification of the noncoordinative interactions between the compounds and AQP3. AQP3 inhibition is the result of protein conformational changes, upon coordinative gold binding, which induce pore closure. The importance of noncoordinative adducts in modulating the AQP3 inhibition properties of the investigated Au(III) compounds has been elucidated, and these interactions should be further considered in the future design of isoform-selective AQP inhibitors.

9.
Eur J Nutr ; 58(1): 113-130, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29151137

RESUMO

PURPOSE: Epidemiological and intervention studies have attempted to link the health effects of a diet rich in fruits and vegetables with the consumption of polyphenols and their impact in neurodegenerative diseases. Studies have shown that polyphenols can cross the intestinal barrier and reach concentrations in the bloodstream able to exert effects in vivo. However, the effective uptake of polyphenols into the brain is still regarded with some reservations. Here we describe a combination of approaches to examine the putative transport of blackberry-digested polyphenols (BDP) across the blood-brain barrier (BBB) and ultimate evaluation of their neuroprotective effects. METHODS: BDP was obtained by in vitro digestion of blackberry extract and BDP major aglycones (hBDP) were obtained by enzymatic hydrolysis. Chemical characterization and BBB transport of extracts were evaluated by LC-MSn. BBB transport and cytoprotection of both extracts was assessed in HBMEC monolayers. Neuroprotective potential of BDP was assessed in NT2-derived 3D co-cultures of neurons and astrocytes and in primary mouse cerebellar granule cells. BDP-modulated genes were evaluated by microarray analysis. RESULTS: Components from BDP and hBDP were shown to be transported across the BBB. Physiologically relevant concentrations of both extracts were cytoprotective at endothelial level and BDP was neuroprotective in primary neurons and in an advanced 3D cell model. The major canonical pathways involved in the neuroprotective effect of BDP were unveiled, including mTOR signaling and the unfolded protein response pathway. Genes such as ASNS and ATF5 emerged as novel BDP-modulated targets. CONCLUSIONS: BBB transport of BDP and hBDP components reinforces the health benefits of a diet rich in polyphenols in neurodegenerative disorders. Our results suggest some novel pathways and genes that may be involved in the neuroprotective mechanism of the BDP polyphenol components.


Assuntos
Barreira Hematoencefálica/metabolismo , Fármacos Neuroprotetores/farmacologia , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Rubus/metabolismo , Animais , Células Cultivadas , Cromatografia Líquida , Humanos , Técnicas In Vitro , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos BALB C , Modelos Animais , Fármacos Neuroprotetores/metabolismo , Extratos Vegetais/metabolismo , Reação em Cadeia da Polimerase , Polifenóis/metabolismo
10.
Angew Chem Int Ed Engl ; 57(44): 14524-14528, 2018 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-29972613

RESUMO

The binding modes and free-energy landscape of two AuI /N-heterocyclic carbene complexes interacting with G-quadruplexes, namely a human telomeric (hTelo) and a promoter sequence (C-KIT1), are studied here for the first time by metadynamics. The theoretical results are validated by FRET DNA melting assays and provide an accurate estimate of the absolute gold complex/DNA binding free energy. This advanced in silico approach is valuable to achieve rational drug design of selective G4 binders.


Assuntos
DNA/química , Quadruplex G , Ouro/química , Transferência Ressonante de Energia de Fluorescência , Estrutura Molecular
11.
Biochim Biophys Acta ; 1860(8): 1583-95, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26987810

RESUMO

BACKGROUND: Complex diseases such as cancer are a consequence of numerous causes. State of the art personalised medicine approaches are mostly based on evaluating patients' individual genetic background. Despite the advances of genomics it fails to take individual dynamic influences into account that contribute to the individual and unique glycomic and glycoproteomic "configurations" of every living being. SCOPE OF REVIEW: Glycomic and glycoproteomic-based personalised medicine diagnostics are still in their infancies, however some initial success stories indicate that these fields are highly promising to mediate novel early diagnosis and disease stratification markers, subsequently resulting in improved patient well-being and reduced treatment costs. In this review we not only summarise current protein glycosylation based examples that substantially improve or possess great potential for personalised medicine, but also describe current limitations as well as future perspectives and challenges associated with establishing protein glycosylation aspects for this purpose. MAJOR CONCLUSIONS: Many protein biomarkers currently in clinical use are glycoproteins, however, their glycosylation status is seldom evaluated in a clinical context. To date just few examples have already been successfully translated into clinical practice, making protein glycosylation a highly promising diagnostic target with humongous potential for personalised medicine. GENERAL SIGNIFICANCE: There is an urgent need for markers that enable the establishment of an individualised and optimised patient treatment at the earliest disease stage possible. The glycosylation status of a patient and/or specific marker proteins can provide important clues that result in improved patient management. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc.


Assuntos
Glicoproteínas/genética , Glicoproteínas/metabolismo , Medicina de Precisão/métodos , Biomarcadores/metabolismo , Glicosilação , Humanos
12.
Biochim Biophys Acta ; 1860(8): 1795-808, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26721331

RESUMO

BACKGROUND: Terminal α2-3 and α2-6 sialylation of glycans precludes further chain elongation, leading to the biosynthesis of cancer relevant epitopes such as sialyl-Lewis X (SLe(X)). SLe(X) overexpression is associated with tumor aggressive phenotype and patients' poor prognosis. METHODS: MKN45 gastric carcinoma cells transfected with the sialyltransferase ST3GAL4 were established as a model overexpressing sialylated terminal glycans. We have evaluated at the structural level the glycome and the sialoproteome of this gastric cancer cell line applying liquid chromatography and mass spectrometry. We further validated an identified target expression by proximity ligation assay in gastric tumors. RESULTS: Our results showed that ST3GAL4 overexpression leads to several glycosylation alterations, including reduced O-glycan extension and decreased bisected and increased branched N-glycans. A shift from α2-6 towards α2-3 linked sialylated N-glycans was also observed. Sialoproteomic analysis further identified 47 proteins with significantly increased sialylated N-glycans. These included integrins, insulin receptor, carcinoembryonic antigens and RON receptor tyrosine kinase, which are proteins known to be key players in malignancy. Further analysis of RON confirmed its modification with SLe(X) and the concomitant activation. SLe(X) and RON co-expression was validated in gastric tumors. CONCLUSION: The overexpression of ST3GAL4 interferes with the overall glycophenotype of cancer cells affecting a multitude of key proteins involved in malignancy. Aberrant glycosylation of the RON receptor was shown as an alternative mechanism of oncogenic activation. GENERAL SIGNIFICANCE: This study provides novel targets and points to an integrative tumor glycomic/proteomic-profiling for gastric cancer patients' stratification. This article is part of a Special Issue entitled "Glycans in personalised medicine" Guest Editor: Professor Gordan Lauc.


Assuntos
Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Antígenos CD15/biossíntese , Proteínas de Neoplasias/biossíntese , Polissacarídeos/biossíntese , Receptores Proteína Tirosina Quinases/metabolismo , Neoplasias Gástricas/metabolismo , Glicômica , Humanos , Antígenos CD15/genética , Proteínas de Neoplasias/genética , Polissacarídeos/genética , Receptores Proteína Tirosina Quinases/genética , Antígeno Sialil Lewis X , Sialiltransferases/biossíntese , Sialiltransferases/genética , Neoplasias Gástricas/genética , beta-Galactosídeo alfa-2,3-Sialiltransferase
13.
Inorg Chem ; 55(5): 2544-57, 2016 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-26867101

RESUMO

A series of new heterodinuclear luminescent complexes with two different organic ligands have been synthesized and characterized. A luminescent Ru(II)(polypyridine) moiety and a metal-based anticancer fragment (AuCl, (p-cymene)RuCl2, (p-cymene)OsCl2, (Cp*)RhCl2, or Au-thioglucose) are the two general features of these complexes. All of the bimetallic compounds have been evaluated for their antiproliferative properties in vitro in human cancer cell lines. Only the complexes containing an Au(I) fragment exhibit antiproliferative activity in the range of cisplatin or higher. The photophysical and electrochemical properties of the bimetallic species have been investigated, and fluorescence microscopy experiments have been performed successfully. The most promising bimetallic cytotoxic complexes (i.e., with the Au-thioglucose scaffold) have shown to be easily taken up by cancer cells at 37 °C in the cytoplasm or in specific organelles. Interestingly, experiments repeated at 4 °C showed no uptake of the bimetallic species inside cells, which confirms involvement of active transport processes. To evaluate the role of glucose transporters in the cell uptake of the gold complexes, inhibition of the GluT-1 (glucose transporter isoform with high level of expression in cancer cells) was achieved, showing only scarce influence on the compounds' uptake. Finally, the observed absence of interactions with nucleic acid model structures suggests that the gold compounds may have different intracellular targets with respect to cisplatin.


Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Complexos de Coordenação/química , Metais/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , DNA/efeitos dos fármacos , Humanos , Luminescência , Espectroscopia de Ressonância Magnética , Espectrofotometria Ultravioleta , Relação Estrutura-Atividade
14.
Chembiochem ; 15(10): 1487-94, 2014 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-24891084

RESUMO

Aquaporins (AQPs) are membrane water/glycerol channels that are involved in many physiological functions. Aquaporin-based modulators are predicted to have potential utility in the treatment of several diseases, as well as chemical tools to assess AQPs function in biological systems. We recently reported gold(III) compounds as human AQP3 inhibitors, with Auphen as the most potent of the series. In this work, we assessed the modulation of aquaporin-7 (AQP7) expressed in an adipocyte cell model and show that Auphen significantly inhibits mouse and human AQP7. By homology modeling and molecular docking it was possible to identify the thioether groups of methionine residues, in particular Met47, as likely candidates for binding to the gold(III) complex. Our data point to Auphen as a useful chemical tool to detect AQP7 function. It might constitute a basis to develop inhibitors with improved affinity towards different aquaglyceroporin isoforms.


Assuntos
Aquaporinas/antagonistas & inibidores , Aquaporinas/metabolismo , Compostos Organoáuricos/química , Compostos Organoáuricos/farmacologia , Células 3T3 , Animais , Aquaporinas/química , Sítios de Ligação , Humanos , Camundongos , Simulação de Acoplamento Molecular
15.
Toxics ; 12(3)2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38535937

RESUMO

Mercury contamination in the Amazon arising from both natural sources and intensive mining activities in the region is a significant public health concern. This metal is used to separate Au from sediments. Accordingly, this study aimed to assess the impact of mining on mercury contamination in the animal and human populations of the Amazon. This overall objective was pursued through a systematic review of the existing literature to assess the impact of Hg and identify gaps in geographic coverage arising from this assessment. Herein, we employed PECO and PRISMA-ScR protocols to select articles published between 2017 and 2023 based on projected points on a map within the biogeographic boundaries of the Amazon. We found that mercury concentrations increase with trophic levels, reaching high values of 3.7 µg/g in the muscles of predatory fish and 34.9 µg/g in human hair. The mean level of mercury in human hair in the whole (Amazon) region exceeds 6 µg/g, surpassing tolerance levels. Although mining regions show high concentrations of Hg, the highest incidence was observed among populations with fish-based diets. It was concluded that continuous research and monitoring of fish in the region are required in order to accurately assess the risk associated with Hg contamination, especially since fish are the main source of protein in this region.

16.
J Proteome Res ; 12(3): 1454-66, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23312025

RESUMO

Gastric cancer is preceded by a carcinogenesis pathway that includes gastritis caused by Helicobacter pylori infection, chronic atrophic gastritis that may progress to intestinal metaplasia (IM), dysplasia, and ultimately gastric carcinoma of the more common intestinal subtype. The identification of glycosylation changes in circulating serum proteins in patients with precursor lesions of gastric cancer is of high interest and represents a source of putative new biomarkers for early diagnosis and intervention. This study applies a glycoproteomic approach to identify altered glycoproteins expressing the simple mucin-type carbohydrate antigens T and STn in the serum of patients with gastritis, IM (complete and incomplete subtypes), and control healthy individuals. The immunohistochemistry analysis of the gastric mucosa of these patients showed expression of T and STn antigens in gastric lesions, with STn being expressed only in IM. The serum glycoproteomic analysis using 2D-gel electrophoresis, Western blot, and MALDI-TOF/TOF mass spectrometry led to the identification of circulating proteins carrying these altered glycans. One of the glycoproteins identified was plasminogen, a protein that has been reported to play a role in H. pylori chronic infection of the gastric mucosa and is involved in extracellular matrix modeling and degradation. Plasminogen was further characterized and showed to carry STn antigens in patients with gastritis and IM. These results provide evidence of serum proteins displaying abnormal O-glycosylation in patients with precursor lesions of gastric carcinoma and include a panel of putative targets for the non-invasive clinical diagnosis of individuals with gastritis and IM.


Assuntos
Carboidratos/sangue , Lesões Pré-Cancerosas/sangue , Proteômica , Neoplasias Gástricas/sangue , Western Blotting , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel Bidimensional , Glicosilação , Humanos , Imuno-Histoquímica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
17.
Electrophoresis ; 34(16): 2337-41, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23775548

RESUMO

The identification of sialylated Thomsen-Friedenreich antigens in proteins poses much interest in the context of cancer research. MALDI-TOF-MS is a powerful technique for this purpose; still it shows considerable low sensitivity for sialylated molecules due to in-source and metastable decomposition. Herein, we report a target-driven strategy to identify these antigens in minute amounts of glycoproteins isolated in polyacrylamide gels. The glycans were recovered from gel spots by reductive ß-elimination, permethylated and analyzed by nano-LC-MALDI-TOF-MS. A computational algorithm was developed to filter spectral noise and enhance/isolate the signals of interest. Sialylated antigens were identified in minute amounts of fetuin (0.1 µg) and plasminogen (1.0 µg) by this approach.MS assignments were further validated by enzymatic methods. This methodology allowed a fivefold decrease in the current LOD of fetuin sialylated O-glycans by MALDI-TOF-MS.


Assuntos
Antígenos Glicosídicos Associados a Tumores/sangue , Cromatografia Líquida/métodos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Algoritmos , Animais , Antígenos Glicosídicos Associados a Tumores/química , Bovinos , Eletroforese em Gel de Poliacrilamida , Fetuínas/química , Glicosilação , Humanos , Limite de Detecção , Metilação , Mucinas/sangue , Mucinas/química , Nanotecnologia , Ácidos Siálicos/química
18.
J Police Crim Psychol ; : 1-17, 2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37359946

RESUMO

This study aims to identify the determinants of burnout in police officers. We considered a wide range of psychosocial risk factors, individual variables that have been previously found to be associated with burnout in police officers (affective and cognitive empathy, self-care), and variables whose unique impact on burnout of police officers needs further clarification (organizational justice and organizational identification). The study was conducted in Portugal, and the sample was constituted by 573 members of the National Republican Guard (GNR-Guarda Nacional Republicana). The participants were invited to answer an online anonymous survey, which included previously validated measures of the following variables: burnout (exhaustion and disengagement), psychosocial risk factors, self-care, empathy (cognitive and affective), organizational justice, and organizational identification. Furthermore, we controlled for the potential impact of demographic variables (age, gender, years of professional experience, religiosity, political orientation, and income). Multiple regression analysis showed that when taken together, only a few of the variables associated with burnout had a unique impact on both exhaustion and disengagement: quantitative demands and affective empathy were burnout risk factors; meaningful work, organizational justice (distributive justice, procedural justice, and interactional justice), and organizational identification were burnout protective factors. Our results highlight the importance of developing theoretical models and planning interventions to prevent burnout in police officers, focusing mainly on the above-mentioned variables.

19.
Food Chem ; 404(Pt A): 134546, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36240567

RESUMO

Chestnut (Castanea sativa) shells (CSS) are a source of bioactive compounds with well demonstrated in-vitro antioxidant properties. Nevertheless, no in-vivo studies have already evaluated this effect. This study evaluated the effects of the oral daily administration of an eco-friendly CSS extract (50 and 100 mg/kg per body weight (b.w.)) to rats regarding in-vivo antioxidant activity, glucose and lipids levels, and metabolomic profiling of polyphenols by LC-ESI-LTQ-Orbitrap-MS. The results demonstrated the in-vivo antioxidant properties in the animals liver, kidney and blood serum, as well as protective effects against hemolysis and rising of blood glucose and lipids levels. New insights on metabolomic profiling of polyphenols proved their absorption and further biotransformation by phase I (hydrogenation and hydroxylation) and II reactions (glucuronidation, methylation and sulfation). This is the first study that attempted to validate a novel nutraceutical ingredient extracted from CSS byin-vivoassays, corroborating the outcomes screened by in-vitro assays.


Assuntos
Antioxidantes , Extratos Vegetais , Ratos , Animais , Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Fenóis/análise , Polifenóis/análise , Suplementos Nutricionais , Lipídeos
20.
Food Res Int ; 170: 112963, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37316050

RESUMO

The present study attempted for the first time to explore the effects of the daily oral intake of a phenolics-rich extract from chestnut shells (CS) on the metabolomic profiling of rat tissues by liquid chromatography coupled to Orbitrap-mass spectrometry (LC-ESI-LTQ-Orbitrap-MS) targeted to polyphenolics and their metabolites and screen potential oxidative stress biomarkers, validating its use as a promising nutraceutical ingredient with outstanding antioxidant properties for the prevention and co-therapy of lifestyle-related diseases triggered by oxidative stress. The results demonstrated new insights into the metabolomic fingerprinting of polyphenols from CS, confirming their absorption and biotransformation by phase I (hydrogenation) and II (glucuronidation, methylation, and sulfation) enzymes. Phenolic acids were the main polyphenolic class, followed by hydrolyzable tannins, flavanols, and lignans. In contrast to the liver, sulfated conjugates were the principal metabolites reaching the kidneys. The multivariate data analysis predicted an exceptional contribution of polyphenols and their microbial and phase II metabolites to the in-vivo antioxidant response of the CS extract in rats, recommending its use as an appealing source of anti-aging molecules for nutraceuticals. This is the first study that explored the relation between metabolomic profiling of rat tissues and in-vivo antioxidant effects after oral treatment with a phenolics-rich CS extract.


Assuntos
Antioxidantes , Fenóis , Animais , Ratos , Estresse Oxidativo , Suplementos Nutricionais , Polifenóis , Biomarcadores
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