Partículas superparamagnéticas ultrapequeñas de óxido de hierro para aplicaciones biomédicas

Las partículas superparamagnéticas ultrapequeñas de óxido de hierro (USPIO) tienen una enorme utilidad enBiomedicina como agentes de contraste en resonancia magnética de imagen o como sistemas transportadores defármacos, entre otras aplicaciones. La naturaleza del recubrimiento de los núcleos inorgánicos de las partículasUSPIO determina su estabilidad in vitro y su comportamiento in vivo, siendo especialmente importantes sus propiedadesfi sicoquímicas, en concreto el tamaño, la carga superfi cial y la densidad del recubrimiento. Las pequeñasdimensiones de las partículas USPIO hace difícil una caracterización fi sicoquímica completa, la cuál es de sumaimportancia para poder mejorar su estabilidad y comportamiento in vivo. Esta revisión se centra en las técnicasinstrumentales utilizadas en el análisis de los núcleos magnéticos y de sus recubrimientos orgánicos

Determination of the stability of Kollicoat MAE 30D by means of differential scanning calorimetry

Se estudia la estabilidad de Kollicoat MAE 30D mediante determinaciones calorimétricas y microscópicas. Se estudianlos efectos que producen pH, temperatura y agitación sobre las propiedades fi sicoquímicas de las partículas deeste latex comercial. Se comprueba que el factor que mas infl uencia ejerce es el pH, siendo máxima la estabilidad apH ácidos, y modifi cándose con un decrecimiento de la misma, a partir de pH 6. Se determina la forma y tamañode partícula mediante medidas microfotográfi cas de SEM, realizando el recuento de 200 partículas de una muestradel latex previamente desecado. Se comprueba que la dispersión acuosa de Kollicoat MAE 30 D a su pH natural(2.5), da lugar a una población de partículas con un diámetro medio de 1.56 nm.The stability of Kollicoat MAE 30 D was studied with differential scanning calorimetric, and scanning electronmicroscopy. We investigated the effects of pH, temperature and shaking on physicochemical properties of the latexparticles. Stability of the polymer as most strongly affected by pH; hence, we conclude that the stability of this latexreaches a maximum at acid pH values, where as stability is lost to pH 6.The particle shape and the mean diameter were determined by means of SEM microphotographs on 200 particles in asample of dry latex. The aqueous Kollicoat MAE 30 D dispersion, at its natural pH (2.5), presented one population ofparticles with a mean diameter of 1.56 nm

Ectoparasites of the endangered Iberian lynx Lynx pardinus and sympatric wild and domestic carnivores in Spain

Ectoparasites can cause important skin disorders in animals and can also transmit pathogens. The Iberian lynx Lynx pardinus has been stated to be the most endangered felid in the world and such vector-borne pathogens may threaten its survival. We surveyed 98 wild carnivores (26 Iberian lynxes, 34 red foxes Vulpes vulpes, 24 Egyptian mongooses Herpestes ichneumon, 11 common genets Genetta genetta, two Eurasian badgers Meles meles, one polecat Mustela putorius) and 75 domestic but free-ranging carnivores (46 cats Felis catus, 29 dogs Canis familiaris) from June 2004 to June 2006 in the two areas where the last lynx metapopulations survive: Sierra Morena and Doñana (Andalusia, southern Spain). A total of 65% of lynxes were parasitized (50% by ticks, 19% by fleas, 4% by lice, 31% by hippoboscid flies), as were 75% of foxes (58%, 60%, 0%, 19%), 71% of mongooses (50%, 4%, 46%, 0%), 54% of genets (18%, 36%, 0%, 0%), 30% of cats (22%, 14%, 0%, 2%), and 7% of dogs (surveyed only for ticks). Both badgers presented ticks, fleas and lice. Five species of ixodid ticks (Rhipicephalus pusillus Gil Collado, Rhipicephalus turanicus Pomerantzev and Matikashvili, Ixodes ricinus (Linnaeus), Ixodes hexagonus Leach and Ixodes ventalloi Gil Collado; and Hyalomma sp.), four species of fleas (Ctenocephalides canis Curtis, Pulex irritans Linnaeus, Spilopsyllus cuniculi (Dale), Xenopsylla cunicularis Smit), three species of chewing lice (Felicola (Felicola) inequalis (Piaget), Trichodectes (Trichodectes) melis (Fabricius), and Felicola (Lorisicola) isidoroi Pérez and Palma), and one species of hippoboscid fly (Hippobosca longipennis (Fabricius)) were found. We did not detect any cases of mange. Hippobosca longipennis is a new record for Spanish wildlife, and all the flea species are new records for the Iberian lynx. Fleas were more frequent on lynxes and foxes in winter than in spring. Rhipicephalus spp. were more frequent on cats in spring than in any other season. These and other epidemiological findings are discussed with respect to the conservation of the Iberian lynx.This work was supported by the ‘Programa de Actuaciones para la Conservación del Lince Ibérico en Andalucía II’, Consejería de Medio Ambiente, Junta de Andalucía.Peer reviewe

Levels of heavy metals and metalloids in critically endangered Iberian lynx and other wild carnivores from Southern Spain

This is a contribution to the “Programa de Actuaciones para la Conservación del Lince en Andalucía II”, Consejería de Medio Ambiente, Junta de Andalucía (CMA).The Iberian lynx (Lynx pardinus) is the most endangered felid in the world with a wild population which probably stands at less than 200 individuals inhabiting two areas in Southern Spain (Doñana and Sierra Morena) that are known to have been contaminated by heavy metals and metalloids due to a long history of mining activities. This contamination may pose a threat to long term conservation efforts and hence, the concentrations of seven elements (As, Se, Cd, Zn, Cu, Pb, Hg) were determined in the liver, muscle and bone of 9 lynx, as well as 17 red foxes (Vulpes vulpes), 11 Egyptian mongooses (Herpestes ichneumon), 4 common genets (Genetta genetta) and 1 Eurasian badger (Meles meles). The mean concentrations found were below the threshold levels indicative of chronic intoxication in all the species studied. In general, genet and red fox were species with the highest concentrations of several elements in Doñana, whilst Iberian lynx had the lowest levels of most of them. Lynx from Sierra Morena had significantly higher concentrations of bone Pb (2.05 μg/g d.w.) than those from Doñana (0.13 μg/g d.w.), probably due to the mineralised underlying geology and/or the abandoned mine workings in Sierra Morena. Egyptian mongoose presented liver concentrations of Hg up to 9.7 μg/g d.w. A strong relationship between Hg and Se levels was found in liver and muscle samples of all the studied species, especially in mongoose. In conclusion, levels of the studied elements do not appear to represent a significant threat for the lynx or for the other carnivores studied. However, given the critical status of the Iberian lynx, a continuous monitoring scheme remains necessary.Peer reviewe

Variation of Transaminases, HCV-RNA Levels and Th1/Th2 Cytokine Production during the Post-Partum Period in Pregnant Women with Chronic Hepatitis C

This study analyses the evolution of liver disease in women with chronic hepatitis C during the third trimester of pregnancy and the post-partum period, as a natural model of immune modulation and reconstitution. Of the 122 mothers recruited to this study, 89 were HCV-RNA+ve/HIV-ve and 33 were HCV-RNA-ve/HIV-ve/HCVantibody+ve and all were tested during the third trimester of pregnancy, at delivery and post-delivery. The HCV-RNA+ve mothers were categorized as either Type-A (66%), with an increase in ALT levels in the post-partum period (>40 U/L; P<0.001) or as Type-B (34%), with no variation in ALT values. The Type-A mothers also presented a significant decrease in serum HCV-RNA levels in the post-delivery period (P<0.001) and this event was concomitant with an increase in Th1 cytokine levels (INFγ, P = 0.04; IL12, P = 0.01 and IL2, P = 0.01). On the other hand, the Type-B mothers and the HCV-RNA-ve women presented no variations in either of these parameters. However, they did present higher Th1 cytokine levels in the partum period (INFγ and IL2, P<0.05) than both the Type-A and the HCV-RNA-ve women. Cytokine levels at the moment of delivery do not constitute a risk factor associated with HCV vertical transmission. It is concluded that differences in the ALT and HCV-RNA values observed in HCV-RNA+ve women in the postpartum period might be due to different ratios of Th1 cytokine production. In the Type-B women, the high partum levels of Th1 cytokines and the absence of post-partum variation in ALT and HCV-RNA levels may be related to permanent Th1 cytokine stimulation.This work was supported by the Fondo de Investigaciones Sanitarias (FIS, Instituto de Salud Carlos III), [grant number PI080704]; Consejería de Salud (SAS), Junta de Andalucía, [grant number SAS111213] and Ciberehd (Ciber de Enfermedades Hepáticas y Digestivas (Instituto de Salud Carlos III)