By utilizing a human cDNA expression array blot (588 genes), we have observed overexpression of various transcription factors, cell cycle regulated kinases, and DNA repair genes in HTLV-1-infected T cells. One of the genes of interest, and focus in this study, is the cyclin-dependent kinase inhibitor, p21/waf1. The p21/waf1 transcription and protein is overexpressed in all HTLV-1-infected cell lines tested as well as ATL and HAM/TSP patient samples. While p21/waf1 has been shown to display a selectivity for G(1)/S cyclin/cdk complexes, we have observed p21/waf1 to be complexed with cyclin A/cdk2. Functionally, the association of p21/cyclin A/cdk2 decreased the histone H1 phosphorylation in vitro, as observed in immunoprecipitations followed by kinase assays, as well as affecting other substrates such as the C-terminus of Rb protein involved in c-Abl and HDAC1 regulation. Wild-type, but not a mutant form (M47) of Tax, was found to be able to transactivate the p21/waf1 promoter in a p53-independent manner. We found that the minimal p21/waf1 promoter (-49 to +49 sequence) was activated by Tax and the minimal promoter contained two E2A transcription factor binding sites located between the TATA box and the initiation site. E2A proteins, E12 and E47, as well as a related helix-loop-helix protein, HEB, are all up-regulated in HTLV-1-infected T cells. When using band shift analysis, we found that only the E1 site (overlapping the transcription start site) was a functional DNA binding site. By using a chromatin immunoprecipitation (ChIP) assay, we observed that histone H4, and not histone H3, was acetylated from the endogenous p21/waf1 promoter in vivo, implying that CBP/p300, and not the SAGA complex, was critical in complexing with E2A in up-regulation of p21/waf1 in HTLV-1-infected cells.

RESUMENLa nueva fase de modernización capitalista impuesta en el mundo ha generado una serie de cambios en las jerarquías urbanas heredadas. Hoy, las ciudades se articulan a una serie de fl ujos y circuitos económicos locales, nacionales y globales, formando una Red Mundial de Ciudades (RMC), cuya condición básica de inserción es el nivel de "competitividad urbana". Sin embargo, a pesar de que la competitividad se ha convertido en uno de los objetivos básicos de las políticas públicas urbanas, aún no existe un signifi cado aceptado universalmente, ni tampoco certeza de los factores que la condicionan. Por esto, el propósito de este artícu-lo es analizar y discutir el concepto de competitividad, proponer unos criterios de análisis en el contexto de las ciudades latinoamericanas y evaluar la competitividad de la economía urbana de Santiago de Chile frente a las principales capitales latinoamericanas, de manera de señalar sus potencialidades y restricciones para integrarse a diversos circuitos económicos globales.Palabras clave: Santiago de Chile, competitividad urbana, globalización, ciudades. ABSTRACTThe new phase of capitalist modernization imposed in the world, has generated many changes in inherited urban hierarchies. Today, cities are linked to local, national and global economic fl ows forming a global network of cities, whose basic condition is the degree of integration and level of "urban competitiveness". However, despite the fact that the competitiveness has become one of the basic objectives of urban public policies, there is still no universally accepted meaning, nor certainty of the factors that condition it. Therefore, the purpose of this paper is to analyze and discuss the concept of competitiveness, to propose criteria for its analysis in the context of Latin American cities and assess the competitiveness of Santiago's urban economy compared with major Latin American capital cities, in order to determine its abilities and constraints to integrate different global economic networks.

Resumen Este trabajo analiza los cambios en la calidad de vida urbana en las principales áreas metropolitanas del país en la última década: Gran Santiago, Gran Valparaíso y Gran Concepción. Para tal efecto, aplica el Índice de Calidad de Vida Urbana (ICVU) para determinar posibles patrones y tendencias que puedan dar señales sobre las huellas de esta metropolización. Conforme el hecho que es posible que en la próxima década dos de cada tres personas vivan en áreas metropolitanas en Chile, esta investigación pretende entregar ciertas orientaciones sobre su configuración socioterritorial a actores públicos y privados que tienen incidencia

This paper presents the results of the first characterization and experimental measurements of scatter dose at cardiologist's eyes for the only X-ray system that performs all paediatric Interventional cardiology procedures in Costa Rica. Entrance surface air kerma (ESAK) and the scatter dose values were measured on phantoms of 4-20 cm thicknesses of polymethyl methacrylate slabs. Image quality was evaluated using DICOM images of a test object Leeds TOR 18-FG, through the numerical parameters signal-to-noise ratio (SNR), high-contrast spatial resolution (HCSR) and figure of merit (FOM). When PMMA thickness is increased and during a move from low fluoroscopy to cine modes, ESAK, SNR, HCSR and FOM values range from 0.44 to 391.0 μGy fr-1; 2.8 to 14.89; 3.17 to 15.54 and 0.51 to 79.94, respectively. The highest scattered dose rates recorded during the simulations were 1.79 and 8.04 mSv h-1 for the high fluoroscopy and cine modes, respectively.

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