Development of an ionic liquid-based dispersive liquid-liquid microextraction method for the determination of nifurtimox and benznidazole in human plasma

Dispersive ionic liquid-liquid microextraction combined with liquid chromatography and UV detection was used for the determination of two antichagasic drugs in human plasma: nifurtimox and benznidazole. The effects of experimental parameters on extraction efficiency - the type and volume of ionic liquid and disperser solvent, pH, nature and concentration of salt, and the time for centrifugation and extraction - were investigated and optimized. Matrix effects were detected and thus the standard addition method was used for quantification. This microextraction procedure yielded significant improvements over those previously reported in the literature and has several advantages, including high inter-day reproducibility (relative standard deviation=1.02% and 3.66% for nifurtimox and benznidazole, respectively), extremely low detection limits (15.7 ng mL-1 and 26.5 ng mL-1 for nifurtimox and benznidazole, respectively), and minimal amounts of sample and extraction solvent required. Recoveries were high (98.0% and 79.8% for nifurtimox and benznidazole, respectively). The proposed methodology offers the advantage of highly satisfactory performance in addition to being inexpensive, simple, and fast in the extraction and preconcentration of these antichagasic drugs from human-plasma samples, with these characteristics being consistent with the practicability requirements in current clinical research or within the context of therapeutic monitoring. © 2013 Elsevier B.V

Detección espectrofotométrica de sobredosis de monensina en piensos para bovinos

La creciente presión de la agricultura, así como la búsqueda de mayor eficiencia en los sistemas anaderos, ha conducido al aumento del empleo de productos farmacológicos como estrategias para mejorar la rentabilidad de la ganadería. La monensina (MN) es un antibiótico poliéter del grupo de los ionóforos elaborado a partir del hongo Streptomyces cinnamonensis. En este trabajo se describe la puesta a punto de un método espectrofotométrico sencillo y eficaz para la determinación de MN en muestras de piensos para ganado bovino. Se evaluaron alimentos con diferentes concentraciones de MN conocidas e incógnitas, recolectadas en las provincias de Córdoba y La Pampa (Argentina). Los resultados muestran que el método espectrofotométrico es apropiado para medir MN en piensos a dosis normales y en sobredosificaciones, siendo útil para revelar presuntas intoxicaciones de origen alimentario. Comparada con otros métodos, la técnica revela bajo costo en insumos y equipamiento, aunque requiere cierta laboriosidad. Los resultados del trabajo señalan la idoneidad del método para efectuar la vigilancia farmacológica de MN, dado que brinda un rápido y efectivo diagnóstico en casos de intoxicación, de gran utilidad en laboratorios de baja complejidad.

Intoxicación con monensina en un feedlot de búfalos de Argentina

The aim of this paper was to describe a case of accidental monensin poisoning of feedlot domestic buffalo (Bubalus bubalis) in northeastern Argentina. Clinical signs included anxiety facie with orthopneic position, teeth grinding, diarrhea, muscular weakness, depression and recumbency. In monensin intoxicated animals, a significant increase of creatine phosphokinase and aspartate aminotransferase was observed. At postmortem examination, buffaloes consistently had pale areas that were irregularly distributed in cardiac and skeletal muscles, hydrothorax, congestion and oedema of the lung. Dege-neration and necrosis of the myocardium and skeletal muscle was observed by histological examination. Feed analysis revealed toxic levels of monensin; therefore, ionophore toxicosis was diagnosed. Accordingly, it is required great caution when feeding buffaloes with monensin used as a feed additive.El objetivo de este trabajo fue describir un envenenamiento accidental por monensina en búfalos domésticos (Bubalus bubalis) pertenecientes a un feedlot ubicado en la región nordeste de Argentina. Los signos clínicos incluyeron ansiedad, posición ortopneica con rechinamientode dientes, diarrea, debilidad muscular, depresión y recumbencia. En los animales expuestosa monensina se observaron aumentos significativos de creatin fosfoquinasa y aspartato aminotransferasa. A la necropsia, los búfalos presentaron áreas pálidas de distribución irregular, hidrotórax, congestión y edema pulmonar. Al examen histológico se observó degeneración y necrosis de músculos cardíaco y esquelético. El análisis del alimento reveló niveles tóxicos de monensina, por lo cual se diagnosticó una toxicosis por ionóforos. A pesar de los efectos positivos de la monensina como fuente de alimento de los animales, se debe requerir un mayor nivel de precaución al alimentar búfalos con ionóforos

Vinte anos de integração pesquisa-extensão-agricultor com feijão no Rio Grande do Sul.

bitstream/item/58268/1/7-feijao-Iraja-2011.pd

The Seascape of Demersal Fish Nursery Areas in the North Mediterranean Sea, a First Step Towards the Implementation of Spatial Planning for Trawl Fisheries

The identification of nursery grounds and other essential fish habitats of exploited stocks is a key requirement for the development of spatial conservation planning aimed at reducing the adverse impact of fishing on the exploited populations and ecosystems. The reduction in juvenile mortality is particularly relevant in the Mediterranean and is considered as one of the main prerequisites for the future sustainability of trawl fisheries. The distribution of nursery areas of 11 important commercial species of demersal fish and shellfish was analysed in the European Union Mediterranean waters using time series of bottom trawl survey data with the aim of identifying the most persistent recruitment areas. A high interspecific spatial overlap between nursery areas was mainly found along the shelf break of many different sectors of the Northern Mediterranean indicating a high potential for the implementation of conservation measures. Overlap of the nursery grounds with existing spatial fisheries management measures and trawl fisheries restricted areas was also investigated. Spatial analyses revealed considerable variation depending on species and associated habitat/depth preferences with increased protection seen in coastal nurseries and minimal protection seen for deeper nurseries (e.g. Parapenaeus longirostris 6%). This is partly attributed to existing environmental policy instruments (e.g. Habitats Directive and Mediterranean Regulation EC 1967/2006) aiming at minimising impacts on coastal priority habitats such as seagrass, coralligenous and maerl beds. The new knowledge on the distribution and persistence of demersal nurseries provided in this study can support the application of spatial conservation measures, such as the designation of no-take Marine Protected Areas in EU Mediterranean waters and their inclusion in a conservation network. The establishment of no-take zones will be consistent with the objectives of the Common Fisheries Policy applying the ecosystem approach to fisheries management and with the requirements of the Marine Strategy Framework Directive to maintain or achieve seafloor integrity and good environmental status.Versión del editor4,411