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1.
Anal Chim Acta ; 1309: 342688, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38772668

RESUMO

BACKGROUND: Chlorophenols are routinely determined in aquatic systems to check compliance with the restrictive international legislations set for protection of human and aquatic life. Their control requires affordable analytical methods, particularly in labs at low- and medium-income countries. Liquid chromatography-UV detection is a convenient technique for this purpose, but the availability of suitable sample processing remains pending. Organic solvents are inefficient for extracting the whole range of chlorophenols whereas solid-phase extractions are expensive and labour-intensive. So, an efficient, fast and cheap extraction of chlorophenols, amenable to any lab, would help to cope with their worldwide analytical control in natural waters. RESULTS: A supramolecular solvent (SUPRAS) was tailored for providing mixed interaction mechanisms aimed at the efficient extraction of chlorophenols prior to LC-UV. The SUPRAS was synthesized from the self-assembly of hexylphosphonic acid under acidic conditions and consisted of sponge-like nanostructures made up of amphiphile and water. The phosphoryl (PO) group was selected as the major driver of the extraction because of its ability to act as halogen and hydrogen bond acceptor for chlorophenols. Additional interactions were hydrogen bonds from O-H amphiphilic groups and the surrounding water, and dispersion and CH-π interactions in the hydrocarbon chains. The number of binding sites in the SUPRAS could be modulated by addition of salt. The SUPRAS formed in situ in the sample, the extraction took 5 min, the concentration factor was around 220, quantification limits (0.1-0.3 µg L-1) were below the EU standards, and the method worked for natural waters. SIGNIFICANCE: A fast, low-cost, and organic solvent-free sample processing only requiring conventional lab equipment (stirrers and centrifuges) provided SUPRAS extracts that could be directly analyzed by LC-UV. SUPRAS synthesis occurred spontaneously in the water sample under addition of hexylphosphonic acid and the whole process required low skills. The method meets the analytical and operational performances for the analytical control of chlorophenols in natural waters and it is within the reach of any lab.

2.
Appetite ; 191: 107074, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37827199

RESUMO

Many governments have adopted front-of-pack nutrition labels (FOP labels) that give advice about how healthy a product is. An increasing number of digital food influencers are also informing consumers about the nutritional quality of products and promoting healthy consumption. In this context, the current study analyzes how both sources of information come together to affect purchase intention. Drawing on congruence theory, we propose that the influencer's recommendation reinforces the effect of the FOP label when there is congruence between the two; however, consumers clearly prefer to follow the recommendation of the influencer over the FOP label when the information sources are non-congruent. We develop a between-subjects experimental design in which the level of congruence between the two information sources is manipulated. The effect of the influencer on purchase intention is mediated by the credibility of the FOP label. A second study confirms the superiority of the influencer effect observed in the first study.

3.
Talanta ; 255: 124227, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36587431

RESUMO

Liquid-liquid microextraction (LLME) techniques have experienced a tremendous growth over the last years but still face major challenges related to the use of more efficient and environmentally friendly solvents. Supramolecular solvents (SUPRASs) have proved outstanding efficiency in LLME, but many of the experimental conditions required for SUPRAS formation and/or application cannot be considered green or experimentally convenient. This paper was intended to make greener both SUPRAS formation and their application to the LLME of low-concentration organic pollutants in environmental waters. For this purpose, a variety of SUPRASs were produced at room temperature by simply mixing alkyl phosphonates (A6-12PO3H- and A6-12PO3-2) and tetrahexylammonium (He4N+) ions in aqueous media. Among them, the SUPRASs produced from decyl hydrogen phosphonate (DePO3H-) and He4N+ allowed, for the first time, the development of SUPRAS-based LLMEs where the SUPRAS previously synthesized was added to the liquid sample, instead of being formed in situ as usual, which was proved particularly advantageous for analyses involving large sample/SUPRAS volume ratios. At near equimolar amounts of DePO3H- and He4N+, the amphiphile arranged in the SUPRAS as planar ribbons consisting of water (21 ± 3%, w/v) and DePO3H- and He4N+ in the concentration range 1.0-1.4 M. The application of these SUPRASs to LLMEs was proved by extracting carcinogenic polycyclic aromatic hydrocarbons (CPAHs) from drinking (tap and bottled) and natural (river, reservoir and underground) water (recoveries between 84 and 117% with standard deviations varying between 1 and 14%). The developed method was simple (it only required the addition of 500 µL of SUPRAS to 75 mL of sample, stirring and centrifugation), sensitive (method quantitation limits were below the maximum allowed limits set by the EU; were 0.6-7.1 ng L-1) and selective (SUPRAS extracts were directly analyzed by liquid chromatography-fluorimetry). This research proves that SUPRASs can be operationally used in LLMEs similarly to conventional solvents, which should favor their routine application in high-sample throughput laboratories.


Assuntos
Poluentes Ambientais , Microextração em Fase Líquida , Poluentes Químicos da Água , Poluentes da Água , Solventes , Poluentes da Água/análise , Cromatografia Líquida/métodos , Água/análise , Microextração em Fase Líquida/métodos , Poluentes Ambientais/análise , Poluentes Químicos da Água/análise
4.
Int J Mol Sci ; 25(1)2023 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-38203569

RESUMO

Unlike other coronaviruses, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly infected the global population, with some suffering long-term effects. Thanks to extensive data on SARS-CoV-2 made available through global, multi-level collaborative research, investigators are getting closer to understanding the mechanisms of SARS-CoV-2 infection. Here, using publicly available total and small RNAseq data of Calu3 cell lines, we conducted a comparative analysis of the changes in tRNA fragments (tRFs; regulatory small noncoding RNAs) in the context of severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2 infections. We found extensive upregulation of multiple tRFs in SARS-CoV-2 infection that was not present in SARS-CoV or other virus infections our group has studied. By comparing the total RNA changes in matching samples, we identified significant downregulation of TRDMT1 (tRNA methyltransferase), only in SARS-CoV-2 infection, a potential upstream event. We further found enriched neural functions among downregulated genes with SARS-CoV-2 infection. Interestingly, theoretically predicted targets of the upregulated tRFs without considering mRNA expression data are also enriched in neural functions such as axon guidance. Based on a combination of expression data and theoretical calculations, we propose potential targets for tRFs. For example, among the mRNAs downregulated with SARS-CoV-2 infection (but not with SARS-CoV infection), SEMA3C is a theoretically calculated target of multiple upregulated tRFs and a ligand of NRP1, a SARS-CoV-2 receptor. Our analysis suggests that tRFs contribute to distinct neurological features seen in SARS-CoV-2.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/genética , Regulação para Cima , Regulação para Baixo , RNA de Transferência/genética , Hormônio Liberador de Tireotropina
5.
Front Cell Infect Microbiol ; 12: 906563, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35651755

RESUMO

Background: Ibrexafungerp (SCY-078) is the newest oral and intravenous antifungal drug with broad activity, currently undergoing clinical trials for invasive candidiasis. Objective: The aim of this study was to assess the in vitro activity of ibrexafungerp and comparators against a collection of 434 European blood isolates of Candida. Methods: Ibrexafungerp, caspofungin, fluconazole, and micafungin minimum inhibitory concentrations (MICs) were collected from 12 European laboratories for 434 blood isolates, including 163 Candida albicans, 108 Candida parapsilosis, 60 Candida glabrata, 40 Candida tropicalis, 29 Candida krusei, 20 Candida orthopsilosis, 6 Candida guilliermondii, 2 Candida famata, 2 Candida lusitaniae, and 1 isolate each of Candida bracarensis, Candida catenulata, Candida dubliniensis, and Candida kefyr. MICs were determined by the EUCAST broth microdilution method, and isolates were classified according to recommended clinical breakpoints and epidemiological cutoffs. Additionally, 22 Candida auris from different clinical specimens were evaluated. Results: Ibrexafungerp MICs ranged from 0.016 to ≥8 mg/L. The lowest ibrexafungerp MICs were observed for C. albicans (geometric MIC 0.062 mg/L, MIC range 0.016-0.5 mg/L) and the highest ibrexafungerp MICs were observed for C. tropicalis (geometric MIC 0.517 mg/L, MIC range 0.06-≥8 mg/L). Modal MICs/MIC50s (mg/L) against Candida spp. were 0.125/0.06 for C. albicans, 0.5/0.5 for C. parapsilosis, 0.25/0.25 for C. glabrata, 0.5/0.5 for C. tropicalis, 1/1 for C. krusei, 4/2 for C. orthopsilosis, and 0.5/0.5 for C. auris. Ibrexafungerp showed activity against fluconazole- and echinocandin-resistant isolates. If adopting wild-type upper limits, a non-wild-type phenotype for ibrexafungerp was only observed for 16/434 (3.7%) isolates: 11 (4.6%) C. parapsilosis, 4 (5%) C. glabrata, and 1 (2.5%) C. tropicalis. Conclusion: Ibrexafungerp showed a potent in vitro activity against Candida.


Assuntos
Antifúngicos , Candidíase Invasiva , Antifúngicos/farmacologia , Candida , Candida albicans , Candida glabrata , Candida parapsilosis , Candida tropicalis , Candidíase Invasiva/microbiologia , Fluconazol/farmacologia , Glicosídeos , Micafungina , Triterpenos
6.
J Chromatogr A ; 1667: 462879, 2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35151025

RESUMO

Methanetriyl-pi hydrogen bonding (CH-π HB) in nonpolar domains of supramolecular nanostructures is proposed here as a new mechanism to increase the extraction efficiency of aromatic compounds. The approach is illustrated by the extraction of priority carcinogenic polycyclic aromatic hydrocarbons (CPAHs) in soils using supramolecular nanostructures of carboxylic acids with nonpolar domains consisting of hydrocarbon chains (C6-C10) dispersed in tetrahydrofuran (THF). The high concentration of CH-groups available in the supramolecular nanostructures (38.7-47.3 M) enabled the efficient extraction of CPAHs (recoveries between 89 and 106%), using a supramolecular solvent (SUPRAS) volume/soil amount ratio of 1.5 µL mg-1 and a simple and quick procedure (stirring for 15 min and centrifugation for 10 min). SUPRAS extracts were directly analysed by liquid chromatography-fluorimetry (LC-FL). No sample clean-up or solvent evaporation was required. Optimization of the composition of the nonpolar domains of the SUPRASs was carried out varying the length and concentration of the hydrocarbon chain of the carboxylic acid and the concentration of THF. Method detection limits were in the interval 0.07-0.4 µg kg-1. The relative standard deviations (n = 18, CPAH concentration = 300 µg kg-1), obtained under repeatability and reproducibility conditions, varied within the ranges 2.8-5.4% and 4.3-8.8%, respectively. The accuracy of the method was proved by analysing a certified reference material (CRM) from an industrial soil, contaminated with priority CPAHs at concentrations at the mg kg-1 level (BAM-U013c). The concentration of CPAHs found in soils taken in Southern Spain varied in the range 0.51-49 µg kg-1. The results here obtained demonstrate that CH-π HB is a valuable mechanism for increasing the extraction of aromatic compounds from soils.


Assuntos
Nanoestruturas , Hidrocarbonetos Policíclicos Aromáticos , Ligação de Hidrogênio , Nanoestruturas/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Reprodutibilidade dos Testes , Solo
7.
Plant Physiol Biochem ; 160: 106-119, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33485149

RESUMO

Potassium (K+) exerts key physiological functions such as osmoregulation, stomatal movement, membrane transport, protein synthesis and photosynthesis among others. Previously, it was demonstrated in Arabidopsis thaliana that the loss of function of the chloroplast K+Efflux Antiporters KEA1 and KEA2, located in the inner envelope membrane, provokes inefficient photosynthesis. Therefore, the main goal of this study was to evaluate the potential impact of the loss of function of those cation transport systems in the metabolism of reactive oxygen and nitrogen species (ROS and RNS). Using 14-day-old seedlings from Arabidopsis double knock-out kea1kea2 mutants, ROS metabolism and NO content in roots and green cotyledons were studied at the biochemical level. The loss of function of AtKEA1 and AtKEA2 did not cause oxidative stress but it provoked an alteration of the ROS homeostasis affecting some ROS-generating enzymes. These included glycolate oxidase (GOX) and NADPH-dependent superoxide generation activity, enzymatic and non-enzymatic antioxidants and both NADP-isocitrate dehydrogenase and NADP-malic enzyme activities. NO content, analyzed by confocal laser scanning microscopy (CLSM), was negatively affected in both photosynthetic and non-photosynthetic organs in kea1kea2 mutant seedlings. Furthermore, the S-nitrosoglutathione reductase (GSNOR) protein expression and activity were downregulated in kea1kea2 mutants, whereas the tyrosine nitrated protein profile, analyzed by immunoblot, was unaffected but the relative expression of each immunoreactive band changed. Moreover, kea1kea2 mutants showed an increased photorespiratory pathway and stomata closure, thus promoting a higher resilience to drought stress. Data suggest that the chloroplast osmotic balance and integrity maintained by AtKEA1 and AtKEA2 are necessary to keep the balance of ROS/RNS metabolism. Moreover, these data open new questions about how endogenous NO generation might be affected by the K+/H+ transport located in the chloroplasts.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Cloroplastos/genética , Secas , Óxido Nítrico/metabolismo , Antiportadores de Potássio-Hidrogênio/genética , Espécies Reativas de Oxigênio/metabolismo , Arabidopsis/genética , Técnicas de Inativação de Genes
8.
New Phytol ; 229(4): 2080-2090, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33111995

RESUMO

Photosynthesis and carbon fixation depend critically on the regulation of pH in chloroplast compartments in the daylight and at night. While it is established that an alkaline stroma is required for carbon fixation, it is not known how alkaline stromal pH is formed, maintained or regulated. We tested whether two envelope transporters, AtKEA1 and AtKEA2, directly affected stromal pH in isolated Arabidopsis chloroplasts using the fluorescent probe 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF). External K+ -induced alkalinization of the stroma was observed in chloroplasts from wild-type (WT) plants but not from kea1kea2 mutants, suggesting that KEA1 and KEA2 mediate K+ uptake/H+ loss to modulate stromal pH. While light-stimulated alkalinization of the stroma was independent of KEA1 and KEA2, the rate of decay to neutral pH in the dark is delayed in kea1kea2 mutants. However, the dark-induced loss of a pH gradient across the thylakoid membrane was similar in WT and mutant chloroplasts. This indicates that proton influx from the cytosol mediated by envelope K+ /H+ antiporters contributes to adjustment of stromal pH upon light to dark transitions.


Assuntos
Proteínas de Arabidopsis , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cloroplastos/metabolismo , Concentração de Íons de Hidrogênio , Plastídeos/metabolismo , Antiportadores de Potássio-Hidrogênio/genética
9.
Emerg Infect Dis ; 27(1)2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33352085

RESUMO

Invasive fusariosis (IF) is associated with severe neutropenia in patients with concurrent hematologic conditions. We conducted a retrospective observational study to characterize the epidemiology of IF in 18 Spanish hospitals during 2000-2015. In that time, the frequency of IF in nonneutropenic patients increased from 0.08 cases per 100,000 admissions in 2000-2009 to 0.22 cases per 100,000 admissions in 2010-2015. Nonneutropenic IF patients often had nonhematologic conditions, such as chronic cardiac or lung disease, rheumatoid arthritis, history of solid organ transplantation, or localized fusariosis. The 90-day death rate among nonneutropenic patients (28.6%) and patients with resolved neutropenia (38.1%) was similar. However, the death rate among patients with persistent neutropenia (91.3%) was significantly higher. We used a multivariate Cox regression analysis to characterize risk factors for death: persistent neutropenia was the only risk factor for death, regardless of antifungal therapy.


Assuntos
Fusariose , Fusarium , Neutropenia , Antifúngicos/uso terapêutico , Fusariose/tratamento farmacológico , Fusariose/epidemiologia , Humanos , Neutropenia/tratamento farmacológico , Neutropenia/epidemiologia , Estudos Observacionais como Assunto , Espanha/epidemiologia
11.
Rev Esp Enferm Dig ; 112(12): 961, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33226248

RESUMO

Intestinal intussusception is a condition usually observed in pediatric patients and is rare in adults. It has been described as idiopathic or secondary to several etiologies. Intussusception occurring in the large bowel is more likely to have a malignant etiology. Abdominal computed tomography is the normal diagnostic modality. Colonoscopy may be helpful to distinguish benign from malignant lesions, prior to deciding an appropriate management. An endoscopy approach can be attempted in patients in whom a benign mass is suspected. However, surgery remains the mainstay in adult intussusception, especially when a malignant etiology cannot be ruled out. We present a rare case of colo-colonic intestinal intussusception in an adult diagnosed by outpatient colonoscopy, which is an uncommon way to discover this entity.


Assuntos
Intussuscepção , Adulto , Colo , Colonoscopia , Humanos , Intussuscepção/diagnóstico por imagem , Intussuscepção/etiologia , Intussuscepção/cirurgia , Tomografia Computadorizada por Raios X
12.
J Agric Food Chem ; 68(33): 9014-9023, 2020 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-32687353

RESUMO

Permethrin (PM) is one of the chiral insecticides most widely used around the world. The significant differential toxicity of its four enantiomers and its important adverse effects on human health highlights the need for determination of PM enantiomers. The aim of this work was to develop the first enantioselective method for quantification of PM in fruits and vegetables. The method is based on the extraction of PM enantiomers in supramolecular solvents with restricted access properties (SUPRAS-RAM) and their separation/detection by chiral liquid chromatography-tandem mass spectrometry (LC-MS/MS) which is first reported in this article. SUPRAS-RAM-based extraction is proposed as an innovative treatment approach that drastically reduces solvent consumption and avoids the need for sample cleanup. Extraction of PM enantiomers is quick (vortexing for 5 min) and efficient (recoveries 93-107%). The method is sensitive (quantification limits from 1.0 to 1.2 µg kg-1) and suitable for control of PM enantiomers in agri-food products.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Contaminação de Alimentos/análise , Frutas/química , Inseticidas/química , Permetrina/química , Espectrometria de Massas em Tandem/métodos , Verduras/química , Sensibilidade e Especificidade , Estereoisomerismo
13.
Cell Tissue Bank ; 21(1): 159-165, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31980981

RESUMO

Donor cornea contamination is one of the major risks for corneal transplants. The use of antibiotics in storage media remains as one of the most important security measurements to minimize the contamination risk in corneal preservation. Since antibiotic resistance among microorganisms have been rising gradually, it is important to gain knowledge about the antimicrobial susceptibility pattern for choosing the most suitable antimicrobial agents. Thus, we evaluated the in vitro susceptibility of microorganisms isolated in donor corneas processed at the Center for Blood Transfusion, Tissues and Cells (Córdoba, Spain) during 4 years in order to evaluate the efficiency, and to promote changes for further antibiotics use. Our results show the high rate of resistance to gentamicin, an antibiotic used in corneal preservation media such as Optisol GS and Eusol-C. Conversely, all the analyzed microorganisms were sensitive to vancomycin. This suggests the possibility of replacing gentamicin with another more effective antibacterial agent such as vancomycin.


Assuntos
Antibacterianos/farmacologia , Córnea/microbiologia , Resistência Microbiana a Medicamentos , Gentamicinas/farmacologia , Preservação de Órgãos , Adulto , Idoso , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Sulfatos de Condroitina/farmacologia , Temperatura Baixa , Misturas Complexas/farmacologia , Meios de Cultura Livres de Soro/farmacologia , Dextranos/farmacologia , Feminino , Fungos/efeitos dos fármacos , Fungos/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Preservação de Órgãos/métodos , Soluções para Preservação de Órgãos/farmacologia , Doadores de Tecidos , Vancomicina/farmacologia
14.
Artigo em Inglês | MEDLINE | ID: mdl-29941643

RESUMO

Antifungal resistance is increasing by the emergence of intrinsically resistant species and by the development of secondary resistance in susceptible species. A previous study performed in Spain revealed levels of azole resistance in molds of between 10 and 12.7%, but secondary resistance in Aspergillus fumigatus was not detected. We used itraconazole (ITZ)-supplemented medium to select resistant strains. A total of 500 plates supplemented with 2 mg/liter of ITZ were sent to 10 Spanish tertiary hospitals, and molecular identification and antifungal susceptibility testing were performed. In addition, the cyp51A gene in those A. fumigatus strains showing azole resistance was sequenced. A total of 493 isolates were included in the study. Sixteen strains were isolated from patients with an infection classified as proven, 104 were isolated from patients with an infection classified as probable, and 373 were isolated from patients with an infection classified as colonization. Aspergillus was the most frequent genus isolated, at 80.3%, followed by Scedosporium-Lomentospora (7.9%), Penicillium-Talaromyces (4.5%), Fusarium (2.6%), and the order Mucorales (1%). Antifungal resistance was detected in Scedosporium-Lomentospora species, Fusarium, Talaromyces, and Mucorales Three strains of A. fumigatus sensu stricto were resistant to azoles; two of them harbored the TR34+L98H mechanism of resistance, and the other one had no mutations in cyp51A The level of azole resistance in A. fumigatus remains low, but cryptic species represent over 10% of the isolates and have a broader but overall higher range of antifungal resistance.


Assuntos
Antifúngicos/farmacologia , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/isolamento & purificação , Farmacorresistência Fúngica/efeitos dos fármacos , Triazóis/farmacologia , Aspergillus fumigatus/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Proteínas Fúngicas/metabolismo , Humanos , Itraconazol/farmacologia , Testes de Sensibilidade Microbiana/métodos , Estudos Prospectivos , Espanha
15.
Anal Chim Acta ; 950: 71-79, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-27916133

RESUMO

Restricted access-volatile supramolecular solvents (RAM-VOL-SUPRAS) are here proposed as a new strategy for the quick removal of protein and phospholipids and efficient analyte extraction in LC-MS bioanalysis. Quantification of bisphenol A in urine was selected to prove the suitability of this approach for the intended purpose. RAM-VOL-SUPRAS were spontaneously synthesized in urine by addition of hexanol (83 µL) dissolved in THF (150 µL). SUPRAS composition was environment-dependent and an equation for prediction of SUPRAS volume under given experimental conditions was proposed. Urinary proteins were removed by flocculation by the combined action of THF and hexanol. Phospholipids were extracted in the SUPRAS by the formation of mixed aggregates with hexanol and precipitated as the SUPRAS extract (75 µL) was evaporated to dryness. BPA, re-extracted from the residue, was analysed by LC-(ESI)-MS/MS. Removal of phospholipids by precipitation was proved by monitoring them in both evaporated and unevaporated urine SUPRAS extracts by LC-MS. This removal led to significant reduction in matrix-effects in the determination of BPA. The method quantification limit in urine was 0.025 ng mL-1 and the repeatability for 0.4 ng mL-1 of BPA, expressed as relative standard deviation, was 4.5%. Concentrations of BPA in the urine samples analysed were in the range 0.357-1.58 ng mL-1. Recoveries were within the range 96-107%. This new approach for sample treatment in bioanalysis, based on the simplicity of dual precipitation of proteins and phospholipids, allows obtaining much cleaner extracts than conventional procedures.


Assuntos
Compostos Benzidrílicos/urina , Cromatografia Líquida , Fenóis/urina , Fosfolipídeos/isolamento & purificação , Espectrometria de Massas em Tandem , Humanos , Proteínas/isolamento & purificação , Solventes
16.
Plant Physiol ; 172(1): 441-9, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27443603

RESUMO

It is well established that thylakoid membranes of chloroplasts convert light energy into chemical energy, yet the development of chloroplast and thylakoid membranes is poorly understood. Loss of function of the two envelope K(+)/H(+) antiporters AtKEA1 and AtKEA2 was shown previously to have negative effects on the efficiency of photosynthesis and plant growth; however, the molecular basis remained unclear. Here, we tested whether the previously described phenotypes of double mutant kea1kea2 plants are due in part to defects during early chloroplast development in Arabidopsis (Arabidopsis thaliana). We show that impaired growth and pigmentation is particularly evident in young expanding leaves of kea1kea2 mutants. In proliferating leaf zones, chloroplasts contain much lower amounts of photosynthetic complexes and chlorophyll. Strikingly, AtKEA1 and AtKEA2 proteins accumulate to high amounts in small and dividing plastids, where they are specifically localized to the two caps of the organelle separated by the fission plane. The unusually long amino-terminal domain of 550 residues that precedes the antiport domain appears to tether the full-length AtKEA2 protein to the two caps. Finally, we show that the double mutant contains 30% fewer chloroplasts per cell. Together, these results show that AtKEA1 and AtKEA2 transporters in specific microdomains of the inner envelope link local osmotic, ionic, and pH homeostasis to plastid division and thylakoid membrane formation.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Plastídeos/metabolismo , Antiportadores de Potássio-Hidrogênio/metabolismo , Sequência de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/classificação , Proteínas de Arabidopsis/genética , Clorofila/metabolismo , Cloroplastos/genética , Cloroplastos/metabolismo , Cloroplastos/ultraestrutura , Regulação da Expressão Gênica de Plantas , Homeostase , Concentração de Íons de Hidrogênio , Immunoblotting , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Mutação , Osmose , Fotossíntese/genética , Complexo de Proteínas do Centro de Reação Fotossintética/genética , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo , Filogenia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas , Plastídeos/genética , Plastídeos/ultraestrutura , Antiportadores de Potássio-Hidrogênio/classificação , Antiportadores de Potássio-Hidrogênio/genética , Tilacoides/química , Tilacoides/metabolismo
17.
J Plant Physiol ; 188: 44-8, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26414709

RESUMO

Heterotrimeric G proteins (G-proteins) are versatile signaling elements conserved in Eukaryotes. In animals G-proteins relay signals from 7-transmembrane spanning G protein-coupled receptors (GPCRs) to intracellular downstream effectors; however, the existence of GPCRs in plants is controversial. Contrastingly, a surplus of receptor-like kinases (RLKs) provides signal recognition at the plant cell surface. It is established that G proteins are involved in plant defense and suggested that they relay signals from defense-related RLKs. However, it is unclear how the signaling is conducted, as physical interaction between the RLKs and G proteins has not been demonstrated. Using yeast split-ubiquitin system and Bimolecular Fluorescence Complementation assays, we demonstrate physical interaction between the Gα, Gγ1 and Gγ2 subunits, and the defense-related RD-type receptor like kinases CERK1, BAK1 and BIR1. At the same time, no interaction was detected with the non-RD RLK FLS2. We hypothesize that G-proteins mediate signal transduction immediately downstream of the pathogenesis-related RLKs.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Regulação da Expressão Gênica de Plantas , Proteínas Heterotriméricas de Ligação ao GTP/genética , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo
18.
Rev. iberoam. micol ; 32(2): 63-70, abr.-jun. 2015. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-137303

RESUMO

Las mucormicosis son infecciones generalmente agudas, angioinvasivas, que provocan necrosis difusas no supurantes y gran destrucción tisular. Representan el 1,6% de todas las infecciones fúngicas invasivas, y predominan en pacientes inmunodeprimidos con factores de riesgo. Su incidencia se ha incrementado de forma significativa, incluso en pacientes sin inmunodeficiencias. A propósito de un caso de mucormicosis diseminada producida por Rhizomucor pusillus en un paciente joven sin inmunodeficiencias conocidas, hemos realizado una revisión bibliográfica de los casos de mucormicosis en pacientes adultos sin inmunodeficiencias reportados en PubMed, según sus principales localizaciones anatómicas y con referencia especial a los casos de mucormicosis diseminadas. Se revisan los principales factores de riesgo y la patogenia de la enfermedad, las formas clínicas de presentación y sus posibilidades diagnósticas, incidiendo en las técnicas de diagnóstico precoz, y la terapia actual disponible, discutiendo la indicación del tratamiento de combinación de antifúngicos y el pronóstico. Además, se revisa la taxonomía actual del género Mucor y su clasificación (AU)


Mucormycosis is usually an acute angioinvasive infections, which leads to non-suppurative necrosis and significant tissue damage. It represents 1.6% of all the invasive fungal infections and predominates in immunosuppressed patients with risk factors. Incidence has been significantly increased even in immunocompetent patients. Due to finding a case of disseminated mucormycosis caused by Rhizomucor pusillus in a young immunocompetent patient, a systematic review was carried out of reported cases in PubMed of mucormycosis in immunocompetent adults according to the main anatomic locations, and especially in disseminated cases. A review of the main risk factors and pathogenicity, clinical manifestations, techniques of early diagnosis, current treatment options, and prognosis is presented. Taxonomy and classification of the genus Mucorhas also been reviewed (AU)


Assuntos
Humanos , Mucormicose/epidemiologia , Anfotericina B/uso terapêutico , Fungemia/epidemiologia , Mucorales/patogenicidade , Rhizomucor/patogenicidade , Micoses/complicações , Fatores de Risco , Terapia de Imunossupressão
19.
Anal Bioanal Chem ; 407(16): 4721-31, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25869485

RESUMO

Toxicity of pharmaceuticals to aquatic biota is still largely unknown, and no research on the stereoselective toxicity of chiral drugs to these organisms has been undertaken to date. Because of the lack of analytical methods available for this purpose, this manuscript deals, for the first time, with the enantioselective analysis of the non-steroidal anti-inflammatory drugs (NSAIDs) ibuprofen, naproxen and ketoprofen in freshwater fish. The method was based on the microextraction of NSAIDs from fish muscle with a supramolecular liquid made up of inverted hexagonal aggregates of decanoic acid, their enantiomeric separation by liquid chromatography onto a (R)-1-naphthylglycine and 3,5-dinitrobenzoic acid stationary phase and quantification by tandem mass spectrometry. Limits of quantitation (LOQs) for NSAID enantiomers were in the range 1.7-3.3 ng g(-1). Absolute recoveries were from 97 to 104 %, which indicated the high extraction efficiency of the supramolecular solvent. Extraction equilibrium conditions were reached after 10 min which permitted fast sample treatment. Relative standard deviations for enantiomers in fish muscle were always below 6 %. Isotopically labelled internal standards were used to compensate for matrix interferences. The method in-house validation was carried out with the Oncorhynchus mykiss species, and it was applied to the determination of NSAID enantiomers in different fortified freshwater fish species (Alburnus alburnus, Lepomis gibbosus, Micropterus salmoides, O. mykiss and Cyprinus carpio).


Assuntos
Anti-Inflamatórios não Esteroides/análise , Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem/métodos , Truta/metabolismo , Animais , Água Doce , Limite de Detecção , Reprodutibilidade dos Testes , Estereoisomerismo
20.
Rev. iberoam. micol ; 32(1): 46-50, ene.-mar. 2015. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-132896

RESUMO

Antecedentes. Las mucormicosis son infecciones poco frecuentes en pacientes inmunocompetentes, y se han descrito muy pocos casos de mucormicosis asociadas a aspergilosis en pacientes no hematológicos. Caso clínico. Un varón de 17 años, inmunocompetente y sin factores de riesgo previamente conocidos, ingresó en el hospital tras presentar crisis convulsivas 11 días después de sufrir un accidente de moto. Presentó un curso clínico tórpido por infección fúngica invasiva mixta, con afectación pulmonar por Aspergillus niger y mucormicosis diseminada por Rhizomucor pusillus (diagnóstico histopatológico y microbiológico en varios lugares no contiguos). Fue tratado con anfotericina B liposomal durante 7 semanas (dosis total acumulada > 10 g) y precisó múltiples reintervenciones quirúrgicas. El paciente sobrevivió y fue dado de alta de UCI tras 5 meses de evolución y múltiples complicaciones. Conclusiones. El tratamiento con anfotericina B liposomal y el manejo quirúrgico agresivo consiguió la erradicación de la infección fúngica invasiva mixta, pero alertamos de la necesidad de mantener un mayor grado de sospecha clínica y de realizar técnicas de diagnóstico precoz de infecciones fúngicas invasivas en pacientes no inmunodeprimidos para evitar la diseminación de la enfermedad y el mal pronóstico asociado (AU)


Background. Mucormycosis infections are rare in immunocompetent patients, and very few cases of mucormycosis associated with aspergillosis in non-haematological patients have been reported. Case report. A 17-year-old male, immunocompetent and without any previously known risk factors, was admitted to hospital due to a seizure episode 11 days after a motorcycle accident. He had a complicated clinical course as he had a mixed invasive fungal infection with pulmonary involvement due to Aspergillus niger and disseminated mucormycosis due to Rhizomucor pusillus (histopathological and microbiological diagnosis in several non-contiguous sites). He was treated with liposomal amphotericin B for 7 weeks (total cumulative dose > 10 g) and required several surgical operations. The patient survived and was discharged from ICU after 5 months and multiple complications. Conclusions. Treatment with liposomal amphotericin B and aggressive surgical management achieved the eradication of a mixed invasive fungal infection. However, we emphasise the need to maintain a higher level of clinical suspicion and to perform microbiological techniques for early diagnosis of invasive fungal infections in non-immunocompromised patients, in order to prevent spread of the disease and the poor prognosis associated with it (AU)


Assuntos
Humanos , Masculino , Adulto Jovem , Rhizomucor/isolamento & purificação , Rhizomucor/patogenicidade , Aspergillus niger , Aspergillus niger/isolamento & purificação , Aspergillus niger/patogenicidade , Mucormicose/diagnóstico , Mucormicose/tratamento farmacológico , Mucormicose/microbiologia , Anfotericina B/uso terapêutico , Infecções/cirurgia , Infecções/tratamento farmacológico , Rhizomucor , Biópsia/métodos , Controle de Infecções/métodos , Aspergilose Pulmonar/microbiologia , Fatores de Risco , Rinite/complicações , Rinite/microbiologia , Necrose/complicações , Técnicas Microbiológicas
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