Quantitative analysis of interferon alpha receptor subunit 1 and suppressor of cytokine signaling 1 gene transcription in blood cells of patients with chronic hepatitis C

<p>Abstract</p> <p>Background</p> <p>Interferon (IFN)-α receptor 1 (<it>ifnar1</it>) and suppressor of cytokine signaling 1 (<it>socs1</it>) transcription levels were quantified in peripheral blood mononuclear cells (PBMC) of 59 patients infected with hepatitis C virus (HCV) and 17 non-infected individuals. Samples were obtained from patients infected with HCV that were either untreated or treated with IFN-α2 plus ribavirin for 1 year and divided into responders and non-responders based on viral load reduction 6 months after treatment. <it>Ifnar1 </it>and <it>socs1 </it>transcription was quantified by real-time RT-PCR, and the fold difference (2^-ΔΔCT) with respect to <it>hprt </it>housekeeping gene was calculated.</p> <p>Results</p> <p><it>Ifnar1 </it>transcription increased significantly in HCV-infected patients either untreated (3.26 ± 0.31), responders (3.1 ± 0.23) and non-responders (2.18 ± 0.23) with respect to non-infected individuals (1 ± 0.34; <it>P </it>= 0.005). <it>Ifnar1 </it>transcription increased significantly (<it>P </it>= 0.003) in patients infected with HCV genotypes 1a (4.74 ± 0.25) and 1b (2.81 ± 0.25) but not in 1a1b (1.58 ± 0.21). No association was found of <it>Ifnar1 </it>transcription with disease progress, initial viral load or other clinical factors. With respect to <it>socs1 </it>transcription, values were similar for non-infected individuals (1 ± 0.28) and untreated patients (0.99 ± 0.41) but increased in responders (2.81 ± 0.17) and non-responder patients (1.67 ± 0.41). Difference between responder and non-responder patients was not statistically significant. <it>Socs1 </it>transcription increased in patients infected with HCV genotypes 1a and 1b (2.87 ± 0.45 and 2.22 ± 0.17, respectively) but not in 1a1b (1.28 ± 0.40). <it>Socs1 </it>transcript was absent in three patients infected with HCV genotype 1b. A weak correlation between <it>ifnar1 </it>and <it>socs1 </it>transcription was found, when Spearman's correlation coefficient was calculated.</p> <p>Conclusion</p> <p>Our results suggest that HCV infection may up-regulate <it>ifnar1 </it>transcription. HCV genotypes differ in their capacity to affect <it>ifnar1 </it>and <it>socs1 </it>transcription, as well as in the ability to evade the antiviral response.</p

Solid-state reference electrodes based on carbon nanotubes and polyacrylate membranes

A novel potentiometric solid-state reference electrode containing single-walled carbon nanotubes as the transducer layer between a polyacrylate membrane and the conductor is reported here. Single-walled carbon nanotubes act as an efficient transducer of the constant potentiometric signal originating from the reference membrane containing the Ag/AgCl/Cl− ions system, and they are needed to obtain a stable reference potentiometric signal. Furthermore, we have taken advantage of the light insensitivity of single-walled carbon nanotubes to improve the analytical performance characteristics of previously reported solid-state reference electrodes. Four different polyacrylate polymers have been selected in order to identify the most efficient reservoir for the Ag/AgCl system. Finally, two different arrangements have been assessed: (1) a solid-state reference electrode using photo-polymerised n-butyl acrylate polymer and (2) a thermo-polymerised methyl methacrylate:n-butyl acrylate (1:10) polymer. The sensitivity to various salts, pH and light, as well as time of response and stability, has been tested: the best results were obtained using single-walled carbon nanotubes and photo-polymerised n-butyl acrylate polymer. Water transport plays an important role in the potentiometric performance of acrylate membranes, so a new screening test method has been developed to qualitatively assess the difference in water percolation between the polyacrylic membranes studied. The results presented here open the way for the true miniaturisation of potentiometric systems using the excellent properties of single-walled carbon nanotubes

Stress in elementary school students: its relationship with reading

Antecedentes: Numerosas investigaciones mantienen la relación entre los alumnos con dificultades de aprendizaje y el estrés. La lectura tiene dos componentes importantes: la comprensión y la decodificación (errores y velocidad). Objetivo: Nuestro estudio pretende averiguar la relación existente entre el estrés en la escuela y la lectura. Participantes: Se evaluó un grupo de 30 estudiantes de cuarto de primaria. El 56,7% eran chicos y el resto chicas, el 36,7 % estaban escolarizados en modalidad PIP cuya lengua base del programa es el castellano y el resto en modalidad PIL cuya base del programa es el valenciano, aunque también son castellanohablantes. La media del CI era 103 y la media de edad, 118 meses. Las pruebas administradas fueron el Raven-color para el CI, las subpruebas de comprensión de textos, lectura de palabras y pseudopalabras del Prolec-R, y el test IECI para medir el estrés académico. No se encontraron diferencias entre el tipo de escolarización en comprensión lectora. Resultados: Se analizaron las relaciones entre el estrés académico y la comprensión lectora y no se encontró una relación significativa entre las variables. Por otra parte, se correlacionaron la variable de estrés académico con las variables aciertos de palabras y de pseudopalabras y velocidad de palabras y pseudopalabras. Se encontraron correlaciones significativas entre la variable estrés académico y aciertos de palabras, y entre la variable estrés académico y el tiempo empleado para leer dichas palabras. Conclusiones: Se comprueba la relación entre el estrés y el acceso al léxico en la decodificación y la velocidad, tal y como otros estudios habían demostrado.Background: Numerous studies maintain the relationship between students with learning difficulties and stress. Reading has two major components: reading comprehension and decoding (errors and speed). Objective: The aim of this study is to find out the relationship between stress at school and reading. Participants: A group of 30 students from fourth grade of elementary school were evaluated. The 56.7% were boys and the rest were girls, the 36.7% were enrolled in PIP modality which basis language of the program is Spanish and the rest in PIL modality which basis of the program is Valencian but they are also Spanish speakers. The average IQ was 103 and the average age was 118 months. The administered tests were Raven-Color for the IQ, the reading comprehension subtests, reading of words and pseudowords from PROLEC-R and IECI test to measure academic stress. No differences were found between the modality of school attendance (PIP or PIL) in reading comprehension. Results: The relationship between academic stress and reading comprehension were analyzed and no significant relationship between the variables was found. Moreover, the academic stress variable was correlated with the word and the pseudo-words variables, and reading speed in words and pseudo-words. Significant correlations between academic stress and word variable were found, and between academic stress variable and the time taken to read these words. Conclusions: the relationship between stress and lexical access in reading, decoding and speed is proved, as other studies had shown

Biomarcadores asequibles de demencia frontotemporal: un estudio de clasificación basado en la conectividad de redes cerebrales

Developing effective and affordable biomarkers for dementias is critical given the difficulty to achieve early diagnosis. In this sense, electroencephalographic (EEG) methods offer promising alternatives due to their low cost, portability, and growing robustness. Here, we relied on EEG signals and a novel information-sharing method to study resting-state connectivity in patients with behavioral variant frontotemporal dementia (bvFTD) and controls. To evaluate the specificity of our results, we also tested Alzheimer’s disease (AD) patients. The classification power of the ensuing connectivity patterns was evaluated through a supervised classification algorithm (support vector machine). In addition, we compared the classification power yielded by (i) functional connectivity, (ii) relevant neuropsychological tests, and (iii) a combination of both. BvFTD patients exhibited a specific pattern of hypoconnectivity in mid-range frontotemporal links, which showed no alterations in AD patients. These functional connectivity alterations in bvFTD were replicated with a low-density EEG setting (20 electrodes). Moreover, while neuropsychological tests yielded acceptable discrimination between bvFTD and controls, the addition of connectivity results improved classification power. Finally, classification between bvFTD and AD patients was better when based on connectivity than on neuropsychological measures. Taken together, such findings underscore the relevance of EEG measures as potential biomarker signatures for clinical settings.El desarrollo de biomarcadores de demencias efectivos y asequibles resulta esencial dada la dificultad de realizar un diagnóstico temprano de estas patologías. En este sentido, los métodos de electroencefalografía (EEG) brindan alternativas promisorias por su bajo costo, portabilidad y creciente robustez. En este trabajo, nos basamos en señales de EEG y en un novedoso método de intercambio de información para estudiar la conectividad en estado de reposo en pacientes afectados por la variante conductual de la demencia frontotemporal (vcDFT) y en un grupo control. Para evaluar la especificidad de los resultados obtenidos, también examinamos pacientes que padecen la enfermedad de Alzheimer (EA). El poder de clasificación de los patrones de conectividad resultantes se evaluó mediante un algoritmo de clasificación supervisada (máquina de soporte vectorial). Además, comparamos el poder de clasificación obtenido mediante (i) la conectividad funcional, (ii) una batería de pruebas neuropsicológicas pertinentes y (iii) la combinación de ambos. Los pacientes con vcDFT mostraron un patrón de hipoconectividad específico en conexiones frontotemporales de proximidad media, que no mostraron alteraciones en los pacientes con EA. Estas alteraciones en la conectividad funcional en la vcDFT se replicaron mediante EEG de baja densidad (20 electrodos). Por otra parte, mientras que las pruebas neuropsicológicas llevaron a una discriminación aceptable entre los pacientes con vcDFT y los del grupo control, la adición de los resultados de conectividad aumentó el poder de clasificación. Finalmente, la clasificación entre los pacientes con vcDFT y los con EA fue mejor cuando se usó como base la conectividad que cuando se usaron las pruebas neuropsicológicas. En conjunto, estos hallazgos enfatizan la relevancia de las mediciones EEG como biomarcadores con potencial de aplicación clínica