Spectrophotometric determination of copper(II)using 4-vanillideneamino- 3-methyl-5-mercapto-1,2,4-triazole (VAMMT)

1016-1018A rapid and sensitive spectrophotometric method for the determination of copper(II) with 4- vanillideneamino-3-methyl-5-mercapto-1,2,4-triazole (VAMMT) is described. VAMMT reacts with copper(II) at pH 8.5 to give a green colored complex which shows an absorption maximum at 430 nm. Sandell's sensitivity and molar absorptivity of the complex are 0.0646 μg/cm2 and 9.929 ×102 l mol-1 cm-1 respectively. The effect of foreign ions and other experimental variables are studied. Cu(II) has been successfully determined in various alloy samples.

Quantification of dynamic protein complexes using Renilla luciferase fragment complementation applied to protein kinase A activities in vivo

The G protein-coupled receptor (GPCR) superfamily represents the most important class of pharmaceutical targets. Therefore, the characterization of receptor cascades and their ligands is a prerequisite to discovering novel drugs. Quantification of agonist-induced second messengers and downstream-coupled kinase activities is central to characterization of GPCRs or other pathways that converge on GPCR-mediated signaling. Furthermore, there is a need for simple, cell-based assays that would report on direct or indirect actions on GPCR-mediated effectors of signaling. More generally, there is a demand for sensitive assays to quantify alterations of protein complexes in vivo. We describe the development of a Renilla luciferase (Rluc)-based protein fragment complementation assay (PCA) that was designed specifically to investigate dynamic protein complexes. We demonstrate these features for GPCR-induced disassembly of protein kinase A (PKA) regulatory and catalytic subunits, a key effector of GPCR signaling. Taken together, our observations show that the PCA allows for direct and accurate measurements of live changes of absolute values of protein complex assembly and disassembly as well as cellular imaging and dynamic localization of protein complexes. Moreover, the Rluc-PCA has a sufficiently high signal-to-background ratio to identify endogenously expressed Gαs protein-coupled receptors. We provide pharmacological evidence that the phosphodiesterase-4 family selectively down-regulates constitutive β-2 adrenergic- but not vasopressin-2 receptor-mediated PKA activities. Our results show that the sensitivity of the Rluc-PCA simplifies the recording of pharmacological profiles of GPCR-based candidate drugs and could be extended to high-throughput screens to identify novel direct modulators of PKA or upstream components of GPCR signaling cascades

Mujeres jóvenes y ciudadanía en Chile: Una mirada a las nuevas configuraciones políticas

En el marco de los cambios producidos en las formas en que los y las jóvenes se vinculan en su calidad de ciudadanos/as con el Estado, el presente trabajo tiene como propósito identificar y analizar las dimensiones distintivas que pudieran otorgar una mayor profundidad y amplitud a la categoría ciudadanía, desde la perspectiva de las mujeres jóvenes, visibilizando las particularidades asociadas a su doble condición, de jóvenes y de mujeres. Utilizando una metodología integrada, en este estudio exploratorio se llevó a cabo un procesamiento de 156 respuestas de mujeres jóvenes a un cuestionario on-line sobre ciudadanía y género. A partir de ello, se evidencia la visión de los derechos que las jóvenes priorizan como ciudadanas y mujeres, los temas específicos que consideran necesarios de impulsar desde una agenda ciudadana y se pone especial énfasis en las situaciones o ámbitos percibidos como espacios de discriminación de género para las mujeres jóvenes, y que habitualmente, quedan inadvertidos en estudios sobre ciudadanía, que no incorporan la dimensión de género en su análisis. Esto permite dar cuenta de una mayor complejidad conceptual para mirar la ciudadanía, más allá de las concepciones tradicionales.