Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Int J Mol Sci ; 21(17)2020 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-32824881

RESUMO

ß-dystroglycan (ß-DG) assembles with lamins A/C and B1 and emerin at the nuclear envelope (NE) to maintain proper nuclear architecture and function. To provide insight into the nuclear function of ß-DG, we characterized the interaction between ß-DG and emerin at the molecular level. Emerin is a major NE protein that regulates multiple nuclear processes and whose deficiency results in Emery-Dreifuss muscular dystrophy (EDMD). Using truncated variants of ß-DG and emerin, via a series of in vitro and in vivo binding experiments and a tailored computational analysis, we determined that the ß-DG-emerin interaction is mediated at least in part by their respective transmembrane domains (TM). Using surface plasmon resonance assays we showed that emerin binds to ß-DG with high affinity (KD in the nanomolar range). Remarkably, the analysis of cells in which DG was knocked out demonstrated that loss of ß-DG resulted in a decreased emerin stability and impairment of emerin-mediated processes. ß-DG and emerin are reciprocally required for their optimal targeting within the NE, as shown by immunofluorescence, western blotting and immunoprecipitation assays using emerin variants with mutations in the TM domain and B-lymphocytes of a patient with EDMD. In summary, we demonstrated that ß-DG plays a role as an emerin interacting partner modulating its stability and function.


Assuntos
Distroglicanas/metabolismo , Proteínas de Membrana/metabolismo , Distrofia Muscular de Emery-Dreifuss/metabolismo , Proteínas Nucleares/metabolismo , Transporte Ativo do Núcleo Celular , Animais , Linfócitos B/metabolismo , Sítios de Ligação , Linhagem Celular , Células Cultivadas , Distroglicanas/química , Distroglicanas/genética , Células HeLa , Humanos , Proteínas de Membrana/química , Proteínas de Membrana/genética , Camundongos , Distrofia Muscular de Emery-Dreifuss/genética , Mutação , Membrana Nuclear/metabolismo , Proteínas Nucleares/química , Proteínas Nucleares/genética , Ligação Proteica
2.
Electrophoresis ; 33(15): 2374-81, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22887158

RESUMO

The application of programed nebulizing-gas pressure (PNP) has been previously described to be a simple strategy for the separation of anions by capillary electrophoresis-electrospray-mass spectrometry (CE-ESI-MS). The PNP mode provided high resolution and stable analyses and also had the advantage of allowing the use of capillaries wider than the 50-75 µm conventional ones. Here, the application of the PNP approach to the quantitative analysis of pollutants in real samples by CE-ESI-MS is described for the first time; in particular, for the determination several endocrine disruptors (2,4-dichlorophenol, 2,4,5-trichlorophenol, pentachlorophenol, bisphenol-A, 4-tert-butyl-phenol, and 4-tert-butyl benzoic acid) in honey. For sample pretreatment, different liquid-liquid extraction (LLE) procedures were assayed and compared to the QuEChERS(©) methodology prior to electrophoretic analysis. With the application of the PNP approach to CE-ESI-MS, the limits of detection achieved were in the 1-4 ng/g range with a simple liquid-liquid procedure without any further clean-up step; relative standard deviation values in the 2-9% range were found. The analytical characteristics allow the proposed method to be used in the control analysis of these compounds in honey.


Assuntos
Eletroforese Capilar/métodos , Disruptores Endócrinos/análise , Mel/análise , Espectrometria de Massas em Tandem/métodos , Disruptores Endócrinos/isolamento & purificação , Embalagem de Alimentos , Fenóis/análise , Fenóis/isolamento & purificação
3.
Anal Chem ; 83(7): 2834-9, 2011 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21395332

RESUMO

Here we have developed a method for the analysis of anionic compounds by capillary electrophoresis coupled to electrospray ionization-mass spectrometry (CE-ESI-MS). The strategy proposed is based on the application of programmed nebulizing gas pressure (PNP), which is applied during the different steps of analysis: sample injection, electrophoretic separation, and detection by the mass spectrometer. The proposed procedure prevents the frequent drops in current observed in the analysis of anions and allows high separation efficiency by capillary electrophoresis to be maintained because it is not necessary to employ pressured-assisted electrophoresis. Additionally, for the first time we describe the use of 100 µm capillaries in capillary electrophoresis-mass spectrometry, allowing the loading of larger samples and hence greater sensitivity, with no loss of the efficiency achieved with the 50 µm capillaries usually used.


Assuntos
Eletroforese Capilar/métodos , Disruptores Endócrinos/análise , Gases/química , Isoflavonas/análise , Espectrometria de Massas/métodos , Nebulizadores e Vaporizadores , Pressão , Eletro-Osmose , Eletroforese Capilar/instrumentação , Disruptores Endócrinos/isolamento & purificação , Isoflavonas/isolamento & purificação , Espectrometria de Massas/instrumentação
4.
Salud(i)ciencia (Impresa) ; 17(2): 143-147, oct. 2009. graf, ilus
Artigo em Espanhol | LILACS | ID: lil-594169

RESUMO

Se realizó una investigación para determinar los efectos que el uso continuado, por períodos mayores de 6 horas diarias, de los monitores de computación produce en los trabajadores. Se correlacionaron variables como edad, sexo, número de horas frente a las pantallas, tiempo de exposición y labor realizada por los trabajadores, con la presencia de sintomatología ocular referida por ellos. Solamente hubo correlación en el último aspecto. Los trabajadores de oficina fueron las personas que presentaron mayor incidencia de síntomas oculares con un 86.4%. Se describieron los síntomas oculares pertenecientes al síndrome de la computadora, la necesidad de usar cristales graduados, la cefalea y la visión borrosa fueron los mayores síntomas comunicados por los trabajadores, 44.4%, 38.2% y 35.8%, respectivamente. En la muestra estudiada, las normas técnicas para el diseño ergonómico de puestos con monitores fueron cumplidas de manera adecuada, excepto en dos aspectos, el uso de pausas periódicas y la realización de interconsulta con oftalmología, en los cuales se plantearon mayores índices de inadecuación.


An investigation to determine the effects that the use of data display units for long periods of time, i.e. more than6 hours a day, produces in users was carried out. Certain variables, such as age, sex, amount of time in front ofthe units and time of exposure, as well as the work done by users who referred ocular symptoms, were analyzed. It can be stated that there was a correlation only with the last item. Office workers were the patients with the highest incidence of ocular symptoms (86.4%). Ocular symptoms that are included in the «Computer Syndrome¼ are described. The use of graded lenses (44.4%), headaches (38.2%) and blurred vision (35.8%) were the most common symptoms reported by workers. In the sample studied, the technical standards for the ergonomicdesign of work sites with data display units were correctly adhered to, except in two aspects: the use of periodicbreaks and an ophthalmologic cross consultation. Greater inadequacy indexes were found in these two items.


Assuntos
Ergonomia , Oftalmologia , Saúde Ocupacional/estatística & dados numéricos , Saúde Ocular , Categorias de Trabalhadores , Visão Ocular , Cuba
5.
J Sep Sci ; 32(4): 575-84, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19212979

RESUMO

In the present work we address the development of a simple and effective method for the determination of triazine herbicide residues in horticultural products by CE in nonaqueous media (NACE). Potato samples were selected as a representative matrix of such foods with a nonfatty content. Isolation of the analytes from the sample matrix was accomplished by extraction with organic solvents, assisted by ultrasound; a clean-up step of the organic extracts was carried out with SPE, using an Oasis MCX(R) sorbent to retain the analytes directly from the organic medium. The detection limits achieved in spiked potatoes (1.7-4.0 mug/kg) were lower than the default value of maximum residue level (MRL) established by current EU legislation for pesticide residues in foodstuffs. The results obtained were compared with HPLC in order to evaluate the performance of the NACE procedure.


Assuntos
Eletroforese Capilar/métodos , Resíduos de Praguicidas/análise , Resíduos de Praguicidas/química , Solanum tuberosum/química , Solventes , Ultrassom , Cromatografia Líquida de Alta Pressão , Elétrons , Cinética , Estrutura Molecular , Extração em Fase Sólida , Triazinas/química
6.
Electrophoresis ; 28(20): 3606-16, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17893944

RESUMO

We have developed a method involving extraction with mixtures of solvents under pressure (pressurized liquid extraction (PLE)) for the determination of triazine herbicides in a series of samples from the food industry. The organic extracts obtained were subjected to a clean-up step with SPE, using Oasis MCX sorbents, after which they were analyzed by NACE. Potato was chosen as a representative matrix of horticultural products since it has a high water content. Spiked potato samples were used to optimize extraction conditions. In order to compare the results obtained with NACE, different studies were also conducted using HPLC. The detection limits in NACE were similar to those found with HPLC and were of the order of 10-15 microg/kg, depending on the analyte. Satisfactory results were obtained on applying the method proposed for the potato matrix (PLE with separation by electrophoresis) to other food matrices such as other tubercles, fruits, vegetables and cereals.


Assuntos
Eletroforese Capilar/métodos , Análise de Alimentos/métodos , Resíduos de Praguicidas/análise , Solventes/química , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Métodos Analíticos de Preparação de Amostras/normas , Fracionamento Químico/métodos , Grão Comestível/química , Eletroforese Capilar/normas , Interações Hidrofóbicas e Hidrofílicas , Pressão , Sensibilidade e Especificidade , Poluentes do Solo/análise , Solanum tuberosum/química , Extração em Fase Sólida/métodos , Compostos de Sulfonilureia/análise , Triazinas/química , Triazinas/isolamento & purificação
7.
Electrophoresis ; 27(2): 423-32, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16342322

RESUMO

CE in nonaqueous media was used to study the migrating behavior of two weakly basic s-triazine pesticides and one of their metabolites. The target pesticides were selected to be representative for each of the two main groups: propazine and deethylatrazine for the chloro-s-triazines group and ametryn for the methylthio-s-triazines group. To elucidate the phenomena involved, systematic studies were carried out in the different organic media studied. Absolute mobilities were determined in 50% v/v methanol (MeOH)/ACN by extrapolation of the effective mobilities to zero ionic strength in the presence of different concentrations of perchloric acid. Conductivity measurements performed in MeOH and 50 and 20% v/v methanol/ACN permitted the evaluation of the associations of the components of the BGE. The effects of ionic strength on the actual mobilities of the compounds were determined in the presence of perchloric acid and SDS in different organic media. Two different ion-pair equilibria were considered: one due to the presence of perchlorate anions present in the BGE and second that from the added dodecyl sulfate anions. Bearing in mind that these weakly basic compounds can exhibit ion-pair and acid-base equilibria, the acid-base and ion-pair parasite reaction coefficients were determined. Finally, the effects of ionic strength, ion-pair interactions and acid-base properties on the effective electrophoretic mobilities of the analytes are discussed.


Assuntos
Atrazina/análogos & derivados , Praguicidas/química , Triazinas/química , Acetonitrilas/química , Atrazina/química , Soluções Tampão , Eletroforese Capilar , Concentração de Íons de Hidrogênio , Metanol/química , Modelos Químicos , Percloratos/química
8.
Rev. cuba. med. gen. integr ; 19(3)mayo.-jun. 2003. tab, graf
Artigo em Espanhol | CUMED | ID: cum-23488

RESUMO

Se realizó un estudio piloto a 44 casos remitidos al Departamento de Fisioterapia de nuestro municipio con diagnóstico de hipertensión arterial esencial ligera y moderada, aplicándosele 15 sesiones de campo magnético discontinuo durante 15 min. Para buscar el grado de efectividad se utilizó el método estadístico de Mc Nemar, resultando muy significativa la reducción en los valores de la presión arterial, principalmente la máxima. Hubo un favorable efecto socioeconómico, pues se ahorró en el empleo de medicamentos $481.32 al aplicarse esta técnica(AU)


Assuntos
Hipertensão/terapia , Terapias Complementares , Campos Eletromagnéticos
9.
Rev. cuba. med. gen. integr ; 19(3)mayo.-jun. 2003. tab, graf
Artigo em Espanhol | LILACS | ID: lil-386928

RESUMO

Se realizó un estudio piloto a 44 casos remitidos al Departamento de Fisioterapia de nuestro municipio con diagnóstico de hipertensión arterial esencial ligera y moderada, aplicándosele 15 sesiones de campo magnético discontinuo durante 15 min. Para buscar el grado de efectividad se utilizó el método estadístico de Mc Nemar, resultando muy significativa la reducción en los valores de la presión arterial, principalmente la máxima. Hubo un favorable efecto socioeconómico, pues se ahorró en el empleo de medicamentos $481.32 al aplicarse esta técnica


Assuntos
Terapias Complementares , Campos Eletromagnéticos , Hipertensão/terapia
10.
Electrophoresis ; 23(3): 494-501, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11870752

RESUMO

The separation and determination of a mixture of chloro- and methylthiotriazines in water samples by both micellar electrokinetic capillary chromatography (MEKC) and nonaqueous capillary zone electrophoresis (NA-CZE) were compared. The characteristics of both methods proved to be very similar in terms of separation efficiency and analysis times, but application of these methods for the analysis of triazines in natural waters, with a prior preconcentration step, revealed significant differences. A preconcentration step by solid-phase extraction (SPE) with Oasis HLB cartridges was accomplished for the determination of triazines at sub-ppb levels in drinking and river waters; when NA-CZE was used after this SPE step, electropherograms with fewer interferences and more stable baselines were obtained than when separation was carried out using MEKC. Another aspect related to the application to real samples was the lack of precision encountered upon evaluating the electrophoretic signals generated when using SPE coupled with NA-CZE. Here, we demonstrate the importance of choosing an appropriate internal standard for analyte quantification. It is recommended that a triazine belonging to the same family as that of the triazine to be determined should be used as internal standard.


Assuntos
Cromatografia Capilar Eletrocinética Micelar/métodos , Eletroforese Capilar/métodos , Água Doce/análise , Herbicidas/análise , Resíduos de Praguicidas/análise , Triazinas/análise , Poluentes da Água/análise , Cromatografia Capilar Eletrocinética Micelar/normas , Eletroforese Capilar/normas
11.
Rev. cuba. cir ; 40(2): 130-133, abr.-jun. 2001.
Artigo em Espanhol | LILACS, CUMED | ID: lil-628180

RESUMO

Se exponen los resultados obtenidos con el empleo de la laserpuntura a un total de 21 casos remitidos por el Servicio de Angiología con el diagnóstico de úlceras de tipo flebotónicas y postraumáticas al Hospital General "Ciro Redondo"de Artemisa. La información sobre los pacientes se registró en un documento confeccionado al efecto. En la investigación se usó un modelo de grupo único, lineal, y se les aplicó a las tablas el cálculo de X2, así como el valor promedio. Los resultados que se obtuvieron fueron de 95,2 por ciento de mejoría y cura de las lesiones y el 90 por ciento de confianza en afirmar que las úlceras de causa traumática evolucionan de manera favorable y más rápida que las de causa venosa, y reafirman la ventaja de esta modalidad de tratamiento(AU)


The results obtained using laser-puncture in a total of 21 cases referred to the Angiology Service of "Ciro Redondo" General Hospital, in Artemisa province, are shown. Information on patients was registered in a document designed for that purpose. In research, we used a form of linear unique group and the X2 estimate and the average value were applied to the tables. It was obtained 95.2 percent of improvement and cure of lesions and 90 percent of confidence on guaranteeing that the ulcers of traumatic origin evolve in a favorable way and more quickly than those of venous origin, which reaffirms the advantages of this treatment modality(AU)


Assuntos
Humanos , Feminino , Úlcera Varicosa/radioterapia , Varizes/complicações , Terapia a Laser/métodos , Terapia por Acupuntura/métodos
12.
Rev. cuba. cir ; 40(2)abr.-jun. 2001. tab
Artigo em Espanhol | CUMED | ID: cum-31975

RESUMO

Se exponen los resultados obtenidos con el empleo de la laserpuntura a un total de 21 casos remitidos por el Servicio de Angiología con el diagnóstico de úlceras de tipo flebotónicas y postraumáticas al Hospital General Ciro Redondo de Artemisa. La información sobre los pacientes se registró en un documento confeccionado al efecto. En la investigación se usó un modelo de grupo único, lineal, y se les aplicó a las tablas el cálculo de X2, así como el valor promedio. Los resultados que se obtuvieron fueron de 95,2 por ciento de mejoría y cura de las lesiones y el 90 por ciento de confianza en afirmar que las úlceras de causa traumática evolucionan de manera favorable y más rápida que las de causa venosa, y reafirman la ventaja de esta modalidad de tratamiento(AU)


Assuntos
Humanos , Varizes/complicações , Úlcera Varicosa/terapia , Terapia por Acupuntura , Lasers/uso terapêutico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...