Effects of fluticasone propionate on methacholine dose-response curves in nonsmoking atopic asthmatics

Methacholine is frequently used to determine bronchial hyperresponsiveness (BHR) and to generate dose-response curves. These curves are characterized by a threshold (provocative concentration of methacholine producing a 20% fall in forced expiratory volume in one second (PC20) = sensitivity), slope (reactivity) and maximal response (plateau). We investigated the efficacy of 12 weeks of treatment with 1,000 microg fluticasone propionate in a double-blind, placebo-controlled study in 33 atopic asthmatics. The outcome measures used were the influence on BHR and the different indices of the methacholine dose-response (MDR) curve. After 2 weeks run-in, baseline lung function data were obtained and a MDR curve was measured with doubling concentrations of the methacholine from 0.03 to 256 mg x mL(-1). MDR curves were repeated after 6 and 12 weeks. A recently developed, sigmoid cumulative Gaussian distribution function was fitted to the data. Although sensitivity was obtained by linear interpolation of two successive log2 concentrations, reactivity, plateau and the effective concentration at 50% of the plateau value (EC50) were obtained as best fit parameters. In the fluticasone group, significant changes occurred after 6 weeks with respect to means of PC20 (an increase of 3.4 doubling doses), plateau value fall in forced expiratory volume in one second (FEV1) (from 58% at randomization to 41% at 6 weeks) and baseline FEV1 (from 3.46 to 3.75 L) in contrast to the placebo group. Stabilization occurred after 12 weeks. Changes for reactivity were less marked, whereas changes in log, EC50 were not significantly different between the groups. We conclude that fluticasone is very effective in decreasing the maximal airway narrowing response and in increasing PC20. However, it is likely that part of this increase is related to the decrease of the plateau of maximal response

Outcome reporting in randomised controlled trials and meta-analyses of appendicitis treatments in children: a systematic review

Background: Acute appendicitis is the most common surgical emergency in children. Despite this, there is no core outcome set (COS) described for randomised controlled trials (RCTs) in children with appendicitis and hence no consensus regarding outcome selection, definition and reporting. We aimed to identify outcomes currently reported in studies of paediatric appendicitis. / Methods: Using a defined, sensitive search strategy, we identified RCTs and systematic reviews (SRs) of treatment interventions in children with appendicitis. Included studies were all in English and investigated the effect of one or more treatment interventions in children with acute appendicitis or undergoing appendicectomy for presumed acute appendicitis. Studies were reviewed and data extracted by two reviewers. Primary (if defined) and all other outcomes were recorded and assigned to the core areas ‘Death’, ‘Pathophysiological Manifestations’, ‘Life Impact’, ‘Resource Use’ and ‘Adverse Events’, using OMERACT Filter 2.0. / Results: A total of 63 studies met the inclusion criteria reporting outcomes from 51 RCTs and nine SRs. Only 25 RCTs and four SRs defined a primary outcome. A total of 115 unique and different outcomes were identified. RCTs reported a median of nine outcomes each (range 1 to 14). The most frequently reported outcomes were wound infection (43 RCTs, nine SRs), intra-peritoneal abscess (41 RCTs, seven SRs) and length of stay (35 RCTs, six SRs) yet all three were reported in just 25 RCTs and five SRs. Common outcomes had multiple different definitions or were frequently not defined. Although outcomes were reported within all core areas, just one RCT and no SR reported outcomes for all core areas. Outcomes assigned to the ‘Death’ and ‘Life Impact’ core areas were reported least frequently (in six and 15 RCTs respectively). / Conclusions: There is a wide heterogeneity in the selection and definition of outcomes in paediatric appendicitis, and little overlap in outcomes used across studies. A paucity of studies report patient relevant outcomes within the ‘Life Impact’ core area. These factors preclude meaningful evidence synthesis, and pose challenges to designing prospective clinical trials and cohort studies. The development of a COS for paediatric appendicitis is warranted

Polyaniline/palladium nanohybrids for moisture and hydrogen detection.

Palladium nanoparticles display fascinating electronic, optical and catalytic properties, thus they can be used for various applications such as sensor fabrication. Conducting polymers such as polyaniline have also been widely used in sensor technology due to its cost effectiveness, versatility, and ease of synthesis. In this research, attention was given to unify the exceptional properties of these two materials and construct palladium nanoparticle coated polyaniline films to detect hydrogen and moisture. Electrochemical polymerization of aniline was carried out on gold sputtered epoxy resin boards. Polyaniline film was generated across a gap of 0.2 mm created by a scratch made on the gold coating prior to electrochemical polymerization. A palladium nanoparticle dispersion was prepared using sonochemical reduction method and coated on to polyaniline film using drop-drying technique. Polyaniline only films were also fabricated for comparative analysis. Sensitivity of films towards humidity and hydrogen was evaluated using impedance spectroscopy in the presence of the respective species. According to the results, polyaniline films exhibited an impedance drop in the presence of humidity and the response was significantly improved once palladium nanoparticles were incorporated. Interestingly, polyaniline only films did not respond to hydrogen. Nevertheless, palladium nanoparticle coated polyaniline films exhibited remarkable response towards hydrogen

La transformación del paisaje rural-urbano y su efecto sobre los servicios ecosistémicos en una microcuenca de Santiago (Chile)

[spa] Para hacer estudios en Ciencias Ambientales se requiere un nuevo tipo de Ciencia en que el conocimiento sea socialmente robusto y políticamente relevante. Una manera para lograrlo es haciendo diagnósticos científicos que sirvan de base para hacer, luego, mejores diagnósticos con la sociedad. Algunos atributos generales de este tipo de estudios son: se obtienen resultados rápidamente, usando datos disponibles; se integra información de diversas fuentes; se reconoce la incertidumbre de los datos, de su tratamiento y de las interpretaciones que se hagan sobre ellos, y se buscan grandes tendencias, más que resultados precisos. Las ciudades pueden ser investigadas por cualquier disciplina científica. A partir de teorías y metodologías de la Ecología de Ecosistemas y de Paisajes es posible diseñar análisis jerárquicos espacio-temporalmente, para evaluar la relación entre la estructura y la función del paisaje urbano. El concepto de Servicios Ecosistémicos representa una asociación entre naturaleza y bienestar humano. Además, pueden ser medidos como flujos biofísicos (materia y energía) entre ecosistemas, esto es, la función del paisaje. Los Servicios Ecosistémicos cambian si la estructura del paisaje se modifica. La Ecología Urbana, en tanto, es una subdisciplina en desarrollo enfocada en entender el funcionamiento de los ecosistemas y paisajes urbanos, usando conocimientos de la ecología, pero también de otras disciplinas, como la geografía y la historia. Distintas investigaciones en ecología urbana han mostrado que la urbanización tiene un efecto negativo dramático en el paisaje y reduce la producción de servicios ecosistémicos, provocando cambios en la evaporación, la humedad del aire, la velocidad del viento, la infiltración del agua, la escorrentía superficial, la absorción de gases, la extracción de material particulado y la temperatura superficial. En Santiago de Chile, 140 años de expansión urbana han transformado ecosistemas naturales en ecosistemas urbanos. Muchos autores han evaluado los efectos de este proceso sobre los servicios ecosistémicos, siendo claras las consecuencias negativas en aspectos hídricos y meteorológicos pero no tan clara en aquellos relacionados con la calidad del aire, dado que los árboles urbanos contribuyen a su mejoramiento. La Dehesa (1916 ha) es un nuevo barrio (1980’s) de la comuna de Lo Barnechea. Está localizado en el nor-oriente de Santiago de Chile y en una microcuenca diferente a aquella en donde viven la mayor parte de los habitantes de Santiago. Algunas de sus características son: (1) está dominado por casas que tienen más de 200 m2 de superficie construida, (2) sus casas son mayoritariamente aisladas y (3) tiene amplias áreas verdes, parques y bandejones vegetados. En términos de caracterización socioeconómica, La Dehesa tiene un 43% de hogares con la mayor categoría de ingresos (ABC1), siendo superados sólo por las vecinas comunas de Vitacura (59%) y Las Condes (49%). Ecológicamente, el paisaje está actualmente urbanizado. Su estado inmediatamente anterior fue un espinal. Esta formación vegetacional es el resultado del abandono agrícola y una larga historia (200 años) de clareo, desmonte y carboneo, transformando la vegetación esclerófila nativa y la xerofítica nativa, que actualmente se conserva exclusivamente en áreas restauradas o protegidas naturalmente por su geomorfología. El análisis jerárquico espacio-temporal diseñado incluyó fotointerpretación de imágenes satelitales y fotografías aéreas, para describir los cambios estructurales del paisaje en los últimos años (1975-2010). A través de la fotointerpretación de imágenes de muy alta resolución (obtenidas de Google Earth Pro) y las categorías de usos de suelo “HERCULES” (High Ecological Resolution Classification for Urban Landscapes and Environmental Systems); se calculó que la transformación desde espinal a urbano aumentó la cobertura vegetación en un 18% en seis años (2004-2010). Adicionalmente, las imágenes LANDSAT informaron sobre un 33% de aumento en el NDVI en 20 años (1989-2009) a nivel del área urbanizada. La superficie de las áreas urbanizadas aumentó en un 8% entre 2002 y 2009 a nivel de la microcuenca donde se ubica, mientras el grado de urbanización aumentó un 19% dentro del área urbanizada (2004-2010). Se delimitó cada tipo de ecosistemas en el paisaje, usando como variables de homogeneidad: grado de urbanización y cobertura de vegetación a nivel del área urbana. En cada ecosistema se estimó la producción de servicios ecosistémicos a partir de referencias internacionales. Todos estos cambios en la estructura del paisaje tuvieron un efecto positivo para la producción de servicios ecosistémicos de regulación hídrica, de regulación del clima y de mejoramiento de la calidad del aire. Si las tendencias de transformación del paisaje continúan como hasta ahora, la producción seguirá creciendo. Estos datos muestran un paradigma innovador: la urbanización puede incrementar la producción de servicios de la naturaleza, en el corto y mediano plazo, proporcionando beneficios ecológicos diarios a las personas que habitan en el paisaje. Sin embargo, este fenómeno se expresa en una condición socioeconómica que es exclusiva, escasa y espacialmente segregada. Estructuralmente, la urbanización tiene una baja densidad y requiere de grandes cantidades de agua para el riego de las áreas verdes y recursos económicos para su mantención, entre otros costos. Vista la relación positiva, y posible de lograr, entre ciudad y naturaleza, la siguiente pregunta es qué tanto es posible urbanizar y naturalizar al mismo tiempo. Cuáles son las consecuencias de un fuerte incremento de la cobertura vegetacional en un paisaje semiárido es otro punto de interés, especialmente desde una perspectiva hídrica, en un contexto de futura escasez de agua. El desarrollo de estrategias de gestión ambiental para comunas y proyectos inmobiliarios representa una oportunidad y una innovación, debido a que ahora, tras esta investigación, podemos estimar la producción de servicios ecosistémicos y esquematizar sus direcciones de flujo. De esta manera, los efectos negativos pueden ser mitigados o compensados, y los efectos positivos, potenciados.[eng] Environmental Sciences Studies require of a new kind of Science, where knowledge is robust and politically relevant. One way to achieve this purpose is making scientific diagnosis as basis to make diagnosis with Society. Some general attributes of this kind of studies are: to be able to obtain result fast using available data; to integrate information of different sources; to recognize uncertainties of data, its management and interpretations, and looking for significant trends more than precise results. Cities could be researched by any scientific discipline. Following theories and methodologies from Landscape and Ecosystem Ecology is possible to design a hierarchical spatio-temporal analysis to assess relationship between urban landscape structure and function. Ecosystem Services concept represents an association between nature and human wellbeing. Also, they could be measured as biophysical (matter and energy) flows among ecosystems, i.e. landscape function. Ecosystem Services changes if landscape structure is modified. Urban Ecology is a developing subdiscipline focus in to understand the functioning of urban ecosystems and landscapes, using knowledge from ecology but also from other disciplines, like geography and history. Urban ecology research has showed that urbanization has dramatic negative effects on landscape and reduces ecosystem services production, making changes in evaporation, air humidity, wind velocity, water infiltration, surface runoff, gases absorption, particulate matter extraction and surface temperature. In Santiago de Chile, 140 years of urban development have transformed natural ecosystems in urban ecosystems. Many authors have assessed the effects of this process on ecosystem services, being clear the negative consequences in hydric and meteorological aspects, but not so clear in those related with air quality, because urban trees help to improve it. La Dehesa (1916 ha) is a new neighbourhood (1980s) of Lo Barnechea district. It is located in the north-east of Santiago de Chile. It is in a watershed different of the one where the major part of Santiago inhabitants live. Some of its characteristics are: (1) to be dominated with houses that have more than 200m2 of built surface, (2) its houses are detached and (3) to have vast green areas, parks and central median strip plenty of vegetation and grass. In terms of socioeconomic characterization, La Dehesa has a 43% of houses with the highest incomes (ABC1), being overcome only by Vitacura (59%) and Las Condes (49%) districts. Ecologically, the landscape is nowadays urbanized. Before this, its immediately previous state was an espinal. This vegetal formation is the result of agricultural abandonment and a longer history (200 years) of clearing, cutting and charcoal production, transforming native sclerophyllous vegetation and native xerofitic vegetation, which currently is conserved only in geomorphological protected areas and restored areas. We design a spatio-temporal hierarchical analysis that included photointerpretation of satellite and airborne imagery to described structural changes in the last years. Using photointerpretation of very high resolution imagery (from Google Earth Pro) and HERCULES (High Ecological Resolution Classification for Urban Landscapes and Environmental Systems) land uses categories; we calculated that the transformation from espinal to urban increased vegetation cover was 18% in 6 years (2004-2010). Additionally, LANDSAT imagery analysis showed a 33% increase in NDVI index in 20 years (1989-2009) at urbanized area level. Surface of urbanized areas increased in 8% between 2002 and 2009 at watershed level (using Aster imagery), while urbanization degree increased a 19% inside the urbanized area (2004-2010). We delimited each type of ecosystems in the landscape using as variables of homogeneity: urbanization degree and vegetation cover at urbanized area level. In each ecosystem we estimated production of ecosystem services based in international references. All these landscape changes have had positive effects in the ecosystem services production of hydric regulation, climate regulation and air quality improvement. If landscape transformation trends continue as described previously, the production will continue to grow. These data show an innovative paradigm: urbanization can increase nature services in short and medium term, providing daily ecological benefits to people living in the landscape. However, this phenomenon is expressed in a socioeconomic condition that is exclusive, scarce and spatially segregated. Structurally, urbanization has low density and requires large amount of water for irrigation of green areas and economic resources for maintenance, among other costs. Shown the feasible positive feedback between city and nature, the next question is how much is feasible to urbanize and to naturalize at the same time. What are the consequences of a strong increase of vegetation cover in semiarid landscape is another point of interest, especially from a hydric perspective in a context of future water scarcity. Developing environmental management strategies for district and real-state projects represents an opportunity and an innovation, because now we can estimate ecosystem services production and schematize its flow directions. So, negative effects could be mitigated or offset, and positive effects could be promoted