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En los estudios científicos con imagen médica es crucial el control del proceso de selección de variables explicativas, ya que puede ser una fuente importante de sesgos metodológicos de confusión. El objetivo de este trabajo es analizar la viabilidad de emplear los criterios de causalidad (como los enunciados por Bradford Hill) en la selección de variables en artículos publicados en la revista RADIOLOGÍA.

Los estudios del tracto digestivo con control fluoroscópico cada vez se practican con menos frecuencia debido a la introducción de otras técnicas de imagen como la tomografía computarizada o la resonancia magnética y la mayor accesibilidad a la endoscopia. No obstante, continúan apareciendo en muchas guías de práctica clínica y siguen teniendo indicaciones vigentes. Son exploraciones dinámicas y dependientes del operador, que requieren de un entrenamiento para obtener la máxima rentabilidad. Esta revisión pretende repasar la técnica y actualizar las indicaciones de esta modalidad de imagen.

Las revistas científicas son una herramienta fundamental para la difusión de la medicina basada en la evidencia. La calidad científica de una revista está relacionado con el nivel de evidencia de sus publicaciones. El objetivo de nuestro estudio es analizar y cuantificar los cambios temporales de los niveles de evidencia de los artículos publicados en la revista RADIOLOGÍAdurante un período de 6años.

Las guías de práctica clínica son documentos que ayudan a los profesionales y a los pacientes a seleccionar la mejor opción diagnóstica o terapéutica en cada momento. Para su elaboración es necesario realizar una búsqueda eficiente en la literatura y evaluar de forma crítica los artículos encontrados para seleccionar así los más adecuados. Posteriormente se formulan las recomendaciones y se procede a una evaluación externa de la guía antes de proceder a su difusión. Aunque su elaboración es muy minuciosa y rigurosa, es necesario saber si las guías cumplen todos los requisitos metodológicos antes de aplicarlas. Para ello se han desarrollado varias escalas de evaluación crítica, de las cuales, la denominada AGREE IIes la más utilizada en la actualidad. En este artículo se exponen los principales pasos que se siguen en su elaboración, así como los principales aspectos que se deben analizar para saber si la guía está bien escrita.

Los estudios observacionales analíticos aportan información muy relevante sobre la práctica clínica en la vida real, la historia natural de las enfermedades y la sospecha de causalidad. Además, son muy habituales en las revistas científicas.

Un ensayo clínico (EC) es un estudio experimental que evalúa un tratamiento o técnica diagnóstica en seres humanos en términos de eficacia y seguridad. Para asegurar su calidad metodológica y que sus resultados sean ciertos, se han elaborado varios listados de comprobación con la finalidad de identificar si el EC tiene sesgos importantes que invaliden sus conclusiones. El objetivo de este artículo es describir cuáles son los puntos que debemos abordar a la hora de realizar la lectura crítica de un EC. Normalmente, la respuesta a estas cuestiones las encontramos leyendo detenidamente la sección «Material y métodos» y la de «Resultados». La aleatorización, el seguimiento de pacientes (o análisis de las pérdidas), el enmascaramiento y la equivalencia entre los grupos (a excepción de la intervención) son algunos de los aspectos claves en cuanto al diseño. En los resultados debemos valorar qué medidas de eficacia clínica se han utilizado (riesgo relativo, odds ratio o número de pacientes necesario a tratar entre otras) y la precisión de los resultados (intervalos de confianza). Una vez que hemos comprobado que el EC cumple todos estos requisitos, se valorará si los resultados se pueden aplicar en nuestro medio y si los beneficios que se han obtenido justifican los riesgos y costes.

En diagnóstico por imagen pueden elaborarse diferentes Critically Appraised Topics(CAT[temas evaluados críticamente]): comparación de pruebas diagnósticas, evaluación de técnicas de detección precoz (cribado), análisis económico o aspectos terapéuticos entre otros. El diseño variará con la pregunta que se quiera contestar. Por ejemplo, si evaluamos tratamientos, lo mejor es el ensayo clínico, pero si hay estudios secundarios (revisiones sistemáticas o metaanálisis) que reúnan varios ensayos, los resultados serán más importantes y las conclusiones científicamente más relevantes. Independientemente del tema o del diseño del estudio empleado, la elaboración de un CATtiene 6 pasos: 1) pregunta; 2) búsqueda bibliográfica sistemática y eficiente; 3) niveles de evidencia (escoger los artículos de mayor nivel); 4) lectura crítica de los artículos escogidos; 5) aplicar las conclusiones al entorno; y 6) recomendaciones. En este artículo seguiremos cada uno de los pasos, con los matices correspondientes al tipo de estudio.

The ability of Candida albicans to invade mucosal tissues is a major virulence determinant of this organism; however, the mechanism of invasion is not understood in detail. Proteolytic breakdown of E-cadherin, the major protein in epithelial cell junctions, has been proposed as a mechanism of invasion of certain bacteria in the oral mucosa. The objectives of this study were (i) to assess whether C. albicans degrades E-cadherin expressed by oral epithelial cells in vitro; (ii) to compare the abilities of strains with different invasive potentials to degrade this protein; and (iii) to investigate fungal virulence factors responsible for E-cadherin degradation. We found that while E-cadherin gene expression was not altered, E-cadherin was proteolytically degraded during the interaction of oral epithelial cells with C. albicans. Moreover, C. albicans-mediated degradation of E-cadherin was completely inhibited in the presence of protease inhibitors. Using a three-dimensional model of the human oral mucosa, we found that E-cadherin was degraded in localized areas of tissue invasion by C. albicans. An invasion-deficient rim101–/rim101–strain was deficient in degradation of E-cadherin, and this finding suggested that proteases may depend on Rim101p for expression. Indeed, reverse transcription-PCR data indicated that expression of the SAP4, SAP5, and SAP6 genes is severely reduced in the rim101–/rim101–mutant. These SAP genes are functional Rim101p targets, because engineered expression of SAP5 in the rim101–/rim101–strain restored E-cadherin degradation and invasion in the mucosal model. Our data support the hypothesis that there is a mechanism by which C. albicans invades mucosal tissues by promoting the proteolytic degradation of E-cadherin in epithelial adherens junctions.

ABSTRACTThe ability of Candida albicansto invade mucosal tissues is a major virulence determinant of this organism; however, the mechanism of invasion is not understood in detail. Proteolytic breakdown of E-cadherin, the major protein in epithelial cell junctions, has been proposed as a mechanism of invasion of certain bacteria in the oral mucosa. The objectives of this study were (i) to assess whether C. albicansdegrades E-cadherin expressed by oral epithelial cells in vitro; (ii) to compare the abilities of strains with different invasive potentials to degrade this protein; and (iii) to investigate fungal virulence factors responsible for E-cadherin degradation. We found that while E-cadherin gene expression was not altered, E-cadherin was proteolytically degraded during the interaction of oral epithelial cells with C. albicans. Moreover, C. albicans-mediated degradation of E-cadherin was completely inhibited in the presence of protease inhibitors. Using a three-dimensional model of the human oral mucosa, we found that E-cadherin was degraded in localized areas of tissue invasion by C. albicans. An invasion-deficient rim101−/rim101−strain was deficient in degradation of E-cadherin, and this finding suggested that proteases may depend on Rim101p for expression. Indeed, reverse transcription-PCR data indicated that expression of the SAP4, SAP5, and SAP6genes is severely reduced in the rim101−/rim101−mutant. These SAPgenes are functional Rim101p targets, because engineered expression of SAP5in the rim101−/rim101−strain restored E-cadherin degradation and invasion in the mucosal model. Our data support the hypothesis that there is a mechanism by which C. albicansinvades mucosal tissues by promoting the proteolytic degradation of E-cadherin in epithelial adherens junctions.

The recent increase in immunocompromised patient populations, including HIV-infected patients, cancer patients with chemotherapy-induced neutropenia, and transplant recipients receiving immunosuppressive therapy, has led to an increased incidence of clinically significant chronic opportunistic infections. Traditional treatment of chronic persistent infections has strongly relied on the use of antimicrobial drugs. However, unsatisfactory results with drug monotherapy and emergence of resistant strains have prompted the use of adjunctive cytokine therapies for the treatment of these infections. During the past decade, a wide spectrum of immunomodulators has been tested in human clinical trials and animal models of chronic infections caused by a variety of bacteria, fungi, viruses and parasites. This review compiles recent information on advances in the use of cytokines as a therapeutic strategy in chronic bacterial, parasitic, fungal and viral infections.

Candida albicans is a major opportunistic pathogen in immunocompromised patients. Production of proinflammatory cytokines by host cells in response to C. albicans plays a critical role in the activation of immune cells and final clearance of the organism. Invasion of host cells and tissues is considered one of the virulence attributes of this organism. The purpose of this study was to investigate whether the ability of C. albicans to invade host cells and tissues affects the proinflammatory cytokine responses by epithelial and endothelial cells. In this study we used the invasion-deficient RIM101 gene knockout strain DAY25, the highly invasive strain SC5314, and highly invasive RIM101-complemented strain DAY44 to compare the proinflammatory cytokine responses by oral epithelial or endothelial cells. Using a high-throughput approach, we found both qualitative and quantitative differences in the overall inflammatory responses to C. albicans strains with different invasive potentials. Overall, the highly invasive strains triggered higher levels of proinflammatory cytokines in host cells than the invasion-deficient mutant triggered. Significant differences compared to the attenuated mutant were noted in interleukin-1α (IL-1α), IL-6, IL-8, and tumor necrosis factor alpha in epithelial cells and in IL-6, growth-related oncogene, IL-8, monocyte chemoattractant protein 1 (MCP-1), MCP-2, and granulocyte colony-stimulating factor in endothelial cells. Our results indicate that invasion of host cells and tissues by C. albicans enhances the host proinflammatory response to infection.

ABSTRACTCandida albicansis a major opportunistic pathogen in immunocompromised patients. Production of proinflammatory cytokines by host cells in response to C. albicansplays a critical role in the activation of immune cells and final clearance of the organism. Invasion of host cells and tissues is considered one of the virulence attributes of this organism. The purpose of this study was to investigate whether the ability of C. albicansto invade host cells and tissues affects the proinflammatory cytokine responses by epithelial and endothelial cells. In this study we used the invasion-deficient RIM101gene knockout strain DAY25, the highly invasive strain SC5314, and highly invasive RIM101-complemented strain DAY44 to compare the proinflammatory cytokine responses by oral epithelial or endothelial cells. Using a high-throughput approach, we found both qualitative and quantitative differences in the overall inflammatory responses to C. albicansstrains with different invasive potentials. Overall, the highly invasive strains triggered higher levels of proinflammatory cytokines in host cells than the invasion-deficient mutant triggered. Significant differences compared to the attenuated mutant were noted in interleukin-1α (IL-1α), IL-6, IL-8, and tumor necrosis factor alpha in epithelial cells and in IL-6, growth-related oncogene, IL-8, monocyte chemoattractant protein 1 (MCP-1), MCP-2, and granulocyte colony-stimulating factor in endothelial cells. Our results indicate that invasion of host cells and tissues by C. albicansenhances the host proinflammatory response to infection.

Ribotyping and RAPD profiling of a collection of 18 Streptococcus parauberisstrains isolated from diseased turbot in Galicia (NW Spain) was performed in order to analyze the possible genetic variability within this bacterial fish pathogen. In addition, the value of this technique for intraspecific classification and epidemiological studies was evaluated. Ribopatterns of DNA digested with three endonucleases and hybridized with a cDNA probe complementary to highly conserved sequences in the 16S and 23S rRNA genes showed a great homogeneity among the turbot isolates. Compared with ribotyping, RAPD appeared to be a reliable and fast technique for discriminating between isolates of S. parauberison the basis of their farm of isolation and, therefore, represents a powerful tool for epidemiological studies of this fish pathogen.

We review the recent advances in the fabrication and properties of GaAs/AlGaAs and InGaAs/GaAs quantum well (QW) structures grown on (111)A GaAs substrates by atmospheric pressure metalorganic vapor phase epitaxy (MOVPE). We show that a 25-period GaAs/AlGaAs multi-QW (MQW) structure was fabricated with good crystal quality, high photoluminescence (PL) emission intensity and monolayer (ML) interfacial roughness. A PL full width at half maximum (FWHM) of 10.5meV was achieved for a 25-period MQW with a well width of 44Å. This is the narrowest linewidth reported to date for any similar structures grown on (111)A or B substrates by any growth technique. We also report the properties of an InGaAs/GaAs single quantum well structure grown on (111)A GaAs. For this structure, the PL FWHM value was 9.1meV, corresponding to a 1ML interfacial roughness for a well width of 41Å. This is the first demonstration of an InGaAs/GaAs quantum well structure grown on (111)A or (111)B GaAs by MOVPE.

The applicability of high-resolution X-ray diffractometry (HRXRD) to the structural characterization of epitaxial structures on arbitrarily oriented surfaces is shown. This technique was used to study piezoelectric InGaAs/GaAs multiquantum well and superlattice p-i-n photodiodes grown on (001) and (111)B GaAs. The structural information obtained by HRXRD was important for understanding the optoelectronic behaviour of the diodes, since the strain-induced piezoelectric field strongly affected their characteristics. The interpretation of the HRXRD experiments was possible thanks to a simulation model developed in our laboratory which allows the calculation of any symmetric or asymmetric reflection on an arbitrarily oriented substrate. We also show some examples of the asymmetric distortion of the strained unit cells owning to the substrate misorientation.

Plasmid-borne resistance to fosfomycin in bacteria is due to modification of the antibiotic molecule by a glutathione S-transferase that catalyzes the formation of a covalent bond between the sulfhydryl residue of the cysteine in glutathione and the C-1 of fosfomycin. This reaction results in opening of the epoxide ring of the antibiotic to form an inactive adduct, the structure of which was confirmed by nuclear magnetic resonance. Dialyzed extracts prepared from resistant Escherichia coli strains were unable to modify fosfomycin unless exogenous glutathione was added to the reaction mixtures. Similarly, mutants defective in glutathione biosynthesis were susceptible to fosfomycin, despite harboring a resistance plasmid. Extracts of resistant but not susceptible strains could join glutathione to 1-chloro-2,4-dinitrobenzene, confirming the nature of the enzymatic activity. Adduct formation appeared to be specific for glutathione: none of the other thiols tested (cysteine, N-acetylcysteine, and dithiothreitol) could modify fosfomycin.

Abstract: GaN layers have been grown by plasma-assisted molecular beam epitaxy on AlN-buffered Si(111) substrates. An initial Al coverage of the Si substrate of aproximately 3 nm lead to the best AlN layers in terms of x-ray diffraction data, with values of full-width at half-maximum down to 10 arcmin. A (2�2) surface reconstruction of the AlN layer can be observed when growing under stoichiometry conditions and for substrate temperatures up to 850�C. Atomic force microscopy reveals that an optimal roughness of 4.6 nm is obtained for AlN layers grown at 850�C. Optimization in the subsequent growth of the GaN determined that a reduced growth rate at the beginning of the growth favors the coalescence of the grains on the surface and improves the optical quality of the film. Following this procedure, an optimum x-ray full-width at half-maximum value of 8.5 arcmin for the GaN layer was obtained. Si-doped GaN layers were grown with doping concentrations up to 1.7�1019 cm−3 and mobilities approximately 100 cm2/V s. Secondary ion mass spectroscopy measurements of Be-doped GaN films indicate that Be is incorporated in the film covering more than two orders of magnitude by increasing the Be-cell temperature. Optical activation energy of Be acceptors between 90 and 100 meV was derived from photoluminescence experiments.

The plasmid determinant of resistance to fosfomycin (For) was cloned into pBR322 and located in a 0.7-kilobase segment of DNA by transposon mutagenesis and in vitro deletion analysis. It encodes an 18-kilodalton protein located in the cytoplasm of resistant cells. Its synthesis is constitutive. The For genetic determinant is common to all plasmids isolated since 1975 in an hospital environment as determined by DNA-DNA hybridization. However, plasmids which carry For can be divided into two groups on the basis of size, pattern of antibiotic resistances, incompatibility specificity, and restriction and hybridization properties.

Dopamine and its 5 receptors, which are grouped into two families (D1-like and D2-like), modulate functions at a systemic level in both the central nervous system and periphery. The central nervous system and the immune system are the main adaptive systems, which participate in a continuous and functional crosstalk to guarantee homeostasis. On binding to its 5 dopamine receptors, dopamine acts as a co-regulator of the immune system, contributing to the interaction of the central nervous system and inflammatory events and as a source of communication between the different immune cells. Dopaminergic perturbations in the central nervous system are observed in several neurological and psychiatric disorders. Schizophrenia is one of the most common mental disorders with a poorly understood pathoaetiology that includes genetic and environmental components that promote alterations in the dopaminergic system. Interestingly, abnormalities in dopamine receptors expression in lymphocytes of schizophrenia patients have been reported, often significantly correlating with the severity of the psychotic illness. Here, we review the current literature regarding the dopaminergic system in human lymphocytes and its alterations in schizophrenia.

Los indicadores bibliométricos surgen para cuantificar la producción científica e intentar evaluar su impacto en la comunidad. De forma general, se pueden dividir en indicadores bibliométricos de autores (individuales y de colaboración) y de revista. Los más extendidos dentro del primer grupo son los que miden la producción individual del autor, como el índice de Crown y el índice hy derivados (índice e, índice h5y el absoluto o Ab-index, entre otros). Los indicadores bibliométricos creados para intentar valorar la calidad de la revista son los asociados al Journal Citation Reports(como factor de impacto, el impacto ajustado a un campo de investigación, eigenfactory la influencia por artículo) o asociados a Scopus [Scimago Journal Rank(SJR), el impacto por artículo normalizado por la fuente de cita (SNIP) y CiteScore). El objetivo de este artículo es presentar los principales indicadores bibliométricos, explicar cómo se calculan y discutir sus ventajas y limitaciones.

Se presentan imágenes de un paciente con anosmia progresiva de varios años de evolución.

The molecular mechanism of plasmid-mediated resistance to fosfomycin is described. The antibiotic was inactivated intracellularly and remained inside the cells. Modification was also obtained from cell extracts and was not energy dependent. The modifying enzyme seems to have sulfhydryl groups in its active center.

Purpose: Although delayed-enhancement magnetic resonance imaging (DEMRI) is essential for diagnosis of cardiac sarcoidosis (CS), the test was not available when pacemaker was implamted. Recently, MR-conditional pacemaker has become avilable and we hypothesized that this device would be useful for diagnosis and management of CS. The aim of this study was to assess the diagnostic ability of MR-conditional pacemaker about CS in patients with advanced A-V nodal block (AAVB). Methods: Twenty-seven AAVB patients (14 men, 13 women; mean age, 69 ± 11 years) who were implanted MR-conditional pacemaker were studied. DEMRI was performed 6 weeks after implantation of permanent pacemaker. In patients with positive for DE, additional examinations like echocardiography, radioisotope imaging, biopsy, and coronary computed-tomography were performed due to confirm the diagnosis of CS and exclude coronary artery disease. Results: DE was observed in 12 patients (44 %). Out of 12 patients, 2 patients were excluded for having prior myocardial infarction. Seven of 10 (70 %) patients were diagnosed of CS by the consensus criteria. Compared with non-CS group, CS group had significantly lower age (61 ± 12 years vs. 72 ± 9 years p = 0.017). There was no significant difference about sex, angiotensin-converting enzyme, brain natriuretic peptide, and left ventricular ejection fraction between 2 groups. Six patients had started corticosteroid therapy and 5 patients (83%) recovered A-V nodal conduction. Conclusion: MR-conditional pacemaker was useful for diagnosis and management of patients with AAVB caused by CS. Figure Cardiac MRI in patient with AV block

Ribotyping and RAPD profiling of a collection of 18 Streptococcus parauberis strains isolated from diseased turbot in Galicia (NW Spain) was performed in order to analyze the possible genetic variability within this bacterial fish pathogen. In addition, the value of this technique for intraspecific classification and epidemiological studies was evaluated. Ribopatterns of DNA digested with three endonucleases and hybridized with a cDNA probe complementary to highly conserved sequences in the 16S and 23S rRNA genes showed a great homogeneity among the turbot isolates. Compared with ribotyping, RAPD appeared to be a reliable and fast technique for discriminating between isolates of S. parauberis on the basis of their farm of isolation and, therefore, represents a powerful tool for epidemiological studies of this fish pathogen.