Photothermal conversion efficiency and cytotoxic effect of gold nanorods stabilized with chitosan, alginate and poly(vinyl alcohol).

Gold nanorods (GNR) use has been proposed in medical applications because of their intrinsic photothermal properties. However, the presence of CTAB molecules adsorbed onto the surface of GNRs results in a highly cytotoxic GNR system. In this work we replace the CTAB molecules with a thiolated chitosan. Once chitosan coated GNRs (Chi-SH-GNR) were attained, a film of alginate (Alg-Chi-SH-GNR) or polyvinyl alcohol (PVA-Chi-SH-GNR) was deposited onto the surface of Chi-GNR by a layer-by-layer process. The photothermal conversion efficiency for the GNR systems was determined irradiating the GNRs suspended in aqua media with a CW 808nm diode laser (CNI, China). The cytotoxicity effect and the photothermal cellular damage of GNR systems were evaluated on a breast cancer cell line. Results show that polymer coats did not affect the transduction photothermal efficiency. Values around 50% were obtained for the different coated gold nanorods. The cytotoxicity of coated gold nanorods diminished significantly compared with those GNR stabilized with CTAB. The laser irradiation of cells treated with gold nanorods showed a decrease in their viability compared with the cells treated but no irradiated.

NIR-light active hybrid nanoparticles for combined imaging and bimodal therapy of cancerous cells.

We report the synthesis of a multifunctional biocompatible theranostic nanoplatform consisting of a biodegradable PLGA matrix surface-functionalized with indocyanine green (ICG), a near-IR fluorescent dye, and co-loaded with superparamagnetic iron oxide nanoparticles (SPIONs) and the anticancer drug doxorubicin (DOXO). Combination of chemo- and photothermal therapeutic efficacy as well as magnetic resonance and optical fluorescence imaging performance were successfully tested in vitro on a tumoral cervical HeLa cell line. Magnetic in vitro guided targeting of these nanoplatforms was also proven. These nanoconstructs also enabled to monitor their in vivo biodistribution by fluorescence imaging in a mice model, which revealed their effective accumulation in the tumor and, unexpectedly, in the brain area. A lower presence of nanoplatforms was noted in the reticulo-endothelial system. The present observations suggest the nanoplatforms ability to possibly overcome the blood brain barrier. These results open up new possibilities to use our multifunctional nanoplatforms to treat brain-located diseases.

Diffuse alveolar hemorrhage in limited cutaneous systemic sclerosis with positive perinuclear antineutrophil cytoplasmic antibodies.

A 54-year-old woman with limited cutaneous systemic sclerosis (SSc) developed repeated diffuse alveolar hemorrhage with positive perinuclear antineutrophil cytoplasmic antibodies (pANCA). Reports of diffuse alveolar hemorrhage in SSc have been rarely described only in the diffuse clinical variant. To our knowledge, this is the first report of pANCA positive diffuse alveolar hemorrhage in the limited form of SSc. Diffuse alveolar hemorrhage is a rare, but potentially life threatening cause of respiratory distress in the limited form of SSc that should be recognized and treated effectively.

Infección intrahospitalaria: un problema en hospitales de segundo nivel de atención médica / Intrahospitalary infections: a problem in the second level hospitals

Con el objeto de conocer la epidemia de las infecciones intrahospitalarias (IIH) en un hospital de 2o. nivel de atención y su repercusión sobre los días de sobreestancia y los costos, se procedió a realizar la deteción de todos los casos en el Hospital de Zona Francisco del Paso y Troncoso del Instituto Mexicano del Seguro Social, durante un período de un año, mediante un sistema de vigilancia continua. En las 301 camas del hospital se registraron 50,397 egresos y en ellos se detectaron 1,153 IIH, para una tasa general de incidencia de 2.3 por 100 egresos: Cirugía General 4.3, Medicina Interna 3.1, Gineco-Obstetricia 3.1 y Neonatología 1.1; sin embargo, se presentaron tasas más elevadas en los partos distócicos (10.4) y en los recién nacidos enfermos y prematuros (12.7). No se observaron variaciones estacionales y se identificaron dos brotes epidémicos: uno en Pediatría por conjuntivitis bacteriana y otro en Medicina Interna por peritonitis secundarias a catéteres de diálisis. Las infecciones más frecuentes fueron deciduoendometritis en Gineco-Obstetricia, infección de heridas quirúrgicas en Cirugía General e infecciones de piel en Medicina Interna y Neonatología. Se identificaron 1402 microorganismos en los pacientes con IIH; predominaron los Gram negativos (72%) sobresaliendo Escherichia coli (56.6%); los Gram positivos se detectaron en un 26.1%. La repercusión en la sobre-estancia hospitalaria fué de 7.3 días, siendo mayor en el servicio de Cirugía (10.3). Cada caso de IIH provocó un gasto promedio de $113,856.00 (más de 113 millones de pesos anuales). La epidemiología de las IIH en los hospitales de segundo nivel de atención, parece corresponder mejor con la realidad nacional que lo observado en los hospitales de tercer nivel. Esta epidemiología tiene particularidades específicas, que deben ser identificadas para realizar las acciones de control correspondientes