Diagnóstico de parásitos en heces del huemul (Hippocamelus bisulcus) en el centro y sur de Chile

Objective. Identify parasites in huemul (Hippocamelus bisulcus) feces from natural protected areas of south–central Chile and evaluate differences in parasite prevalence between regions and seasons. Materials and methods. 200 fecal samples from huemul were collected during all seasons of the year from different localities of the Ñuble, Aysén and Magallanes regions between years 2006 and 2008. Samples were analyzed using flotation and sedimentation techniques and further observed with the microscope in order to detect parasites. Additionally, 124 samples were analyzed to determine the presence of Fasciola hepatica. Results. The 38.0% (n=76/200) of samples were positive to at least one parasite form, evidencing a prevalence of 11.8% (n=2/17) in Ñuble, 22.8% (n=28/123) in Aysén and a 76.7% (n=46/60) in Magallanes. Moniezia sp. eggs were found in the Ñuble region, meanwhile, Strongyle-type eggs, Nematodirus sp. eggs and Eimeria spp. oocysts were found in the Aysén and Magallanes regions. There was no evidence of F. hepatica during sample examination. Differences in parasitism were detected between seasons in Aysén and Magallanes (p≤0.05). Conclusions. Aysén and Magallanes regions showed a relatively higher prevalence and diversity of parasites than the Ñuble region. This could be related to differences in density of huemul populations and livestock in each region. Further parasitological surveys in huemul populations from central and southern Chile should be performed in the future. Studies involving the relationship between the huemul and livestock and the potential inter- and intraspecific transmission of parasites are also required.Objetivo. Identificar parásitos en heces del huemul (Hippocamelus bisulcus) presente en áreas naturales protegidas del centro y sur de Chile y evaluar diferencias en la prevalencia de parásitos entre regiones y estaciones del año. Materiales y métodos. 200 muestras de heces de huemul fueron colectadas de distintas localidades de las regiones de Ñuble, Aysén y Magallanes a lo largo de todas las estaciones entre los años 2006 y 2008. Las muestras fueron analizadas utilizando las técnicas de flotación y sedimentación, para ser posteriormente observadas en el microscopio con el objetivo de detectar parásitos. Adicionalmente, se analizaron 124 de estas muestras para determinar la presencia de Fasciola hepatica. Resultados. El 38.0%(n=76/200) de las muestras analizadas fueron positivas a algún parásito, observándose una prevalencia de 11.8%(n=2/17) en Ñuble, 22.8%(n=28/123) en Aysén y un 76.7%(n=46/60) en Magallanes. En Ñuble se encontraron huevos de Moniezia sp., mientras que en Aysén y Magallanes se identificaron huevos tipo Estrongílido, Nematodirus sp. y ooquistes de Eimeria spp. No se evidenció F. hepatica en las muestras analizadas. Se detectan diferencias de parasitismo entre las estaciones (p≤0.05) en Aysén y Magallanes. Conclusiones. La diferencia en la prevalencia y diversidad parasitaria entre regiones incluidas en este estudio pueden estar relacionadas con la disimilitud en la densidad poblacional de huemules y la masa ganadera de cada región. Es necesario continuar con monitoreos parasitológicos en poblaciones de huemul en Chile sur y central y estudiar la relación de esta especie con el ganado y la posible transmisión inter- e intraespecífica de parásitos

Relict duck-billed dinosaurs survived into the last age of the dinosaurs in subantarctic Chile

In the dusk of the Mesozoic, advanced duck-billed dinosaurs (Hadrosauridae) were so successful that they likely outcompeted other herbivores, contributing to declines in dinosaur diversity. From Laurasia, hadrosaurids dispersed widely, colonizing Africa, South America, and, allegedly, Antarctica. Here, we present the first species of a duck-billed dinosaur from a subantarctic region, Gonkoken nanoi, of early Maastrichtian age in Magallanes, Chile. Unlike duckbills further north in Patagonia, Gonkoken descends from North American forms diverging shortly before the origin of Hadrosauridae. However, at the time, non-hadrosaurids in North America had become replaced by hadrosaurids. We propose that the ancestors of Gonkoken arrived earlier in South America and reached further south, into regions where hadrosaurids never arrived: All alleged subantarctic and Antarctic remains of hadrosaurids could belong to non-hadrosaurid duckbills like Gonkoken. Dinosaur faunas of the world underwent qualitatively different changes before the Cretaceous-Paleogene asteroid impact, which should be considered when discussing their possible vulnerability

KIR+ CD8+ T Lymphocytes in Cancer Immunosurveillance and Patient Survival: Gene Expression Profiling

Killer-cell immunoglobulin-like receptors (KIR) are molecules expressed by the most important cells of the immune system for cancer immune vigilance, natural killer (NK) and effector T cells. In this manuscript we study the role that cytotoxic CD8+ T cells expressing KIR receptors could play in cancer immune surveillance. With this objective, frequencies of different KIR+ CD8+ T cell subsets are correlated with the overall survival of patients with melanoma, ovarian and bladder carcinomas. In addition, the gene expression profile of KIR+ CD8+ T cell subsets related to the survival of patients is studied with the aim of discovering new therapeutic targets, so that the outcome of patients with cancer can be improved. Killer-cell immunoglobulin-like receptors (KIR) are expressed by natural killer (NK) and effector T cells. Although KIR+ T cells accumulate in oncologic patients, their role in cancer immune response remains elusive. This study explored the role of KIR+CD8+ T cells in cancer immunosurveillance by analyzing their frequency at diagnosis in the blood of 249 patients (80 melanomas, 80 bladder cancers, and 89 ovarian cancers), their relationship with overall survival (OS) of patients, and their gene expression profiles. KIR2DL1+ CD8+ T cells expanded in the presence of HLA-C2-ligands in patients who survived, but it did not in patients who died. In contrast, presence of HLA-C1-ligands was associated with dose-dependent expansions of KIR2DL2/S2+ CD8+ T cells and with shorter OS. KIR interactions with their specific ligands profoundly impacted CD8+ T cell expression profiles, involving multiple signaling pathways, effector functions, the secretome, and consequently, the cellular microenvironment, which could impact their cancer immunosurveillance capacities. KIR2DL1/S1+ CD8+ T cells showed a gene expression signature related to efficient tumor immunosurveillance, whereas KIR2DL2/L3/S2+CD8+ T cells showed transcriptomic profiles related to suppressive anti-tumor responses. These results could be the basis for the discovery of new therapeutic targets so that the outcome of patients with cancer can be improved

Melatonin protects rats from radiotherapy-induced small intestine toxicity

Radiotherapy-induced gut toxicity is among the most prevalent dose-limiting toxicities following radiotherapy. Prevention of radiation enteropathy requires protection of the small intestine. However, despite the prevalence and burden of this pathology, there are currently no effective treatments for radiotherapy-induced gut toxicity, and this pathology remains unclear. The present study aimed to investigate the changes induced in the rat small intestine after external irradiation of the tongue, and to explore the potential radio-protective effects of melatonin gel. Male Wistar rats were subjected to irradiation of their tongues with an X-Ray YXLON Y.Tu 320-D03 irradiator, receiving a dose of 7.5 Gy/day for 5 days. For 21 days post-irradiation, rats were treated with 45 mg/day melatonin gel or vehicle, by local application into their mouths. Our results showed that mitochondrial oxidative stress, bioenergetic impairment, and subsequent NLRP3 inflammasome activation were involved in the development of radiotherapy-induced gut toxicity. Oral treatment with melatonin gel had a protective effect in the small intestine, which was associated with mitochondrial protection and, consequently, with a reduced inflammatory response, blunting the NF-κB/NLRP3 inflammasome signaling activation. Thus, rats treated with melatonin gel showed reduced intestinal apoptosis, relieving mucosal dysfunction and facilitating intestinal mucosa recovery. Our findings suggest that oral treatment with melatonin gel may be a potential preventive therapy for radiotherapy-induced gut toxicity in cancer patients.This study was partially supported by grant no. SAF2009-14037 from the Spanish Ministry of Economy and Competitivity (MINECO), GREIB.PT_2010_04 from the CEIBiotic Program of the University of Granada, Spain, and CTS-101 from the Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía, Spain

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

Diagnóstico de parásitos en heces del huemul (Hippocamelus bisulcus) en el centro y sur de Chile

ABSTRACT Objective. Identify parasites in huemul (Hippocamelus bisulcus) feces from natural protected areas of south-central Chile and evaluate differences in parasite prevalence between regions and seasons. Materials and methods. 200 fecal samples from huemul were collected during all seasons of the year from different localities of the Ñuble, Aysén and Magallanes regions between years 2006 and 2008. Samples were analyzed using flotation and sedimentation techniques and further observed with the microscope in order to detect parasites. Additionally, 124 samples were analyzed to determine the presence of Fasciola hepatica. Results. The 38.0% (n=76/200) of samples were positive to at least one parasite form, evidencing a prevalence of 11.8% (n = 2/17) in Ñuble, 22.8% (n = 28/123) in Aysén and a 76.7% (n=46/60) in Magallanes. Moniezia sp. eggs were found in the Ñuble region, meanwhile, Strongyle-type eggs, Nematodirus sp. eggs and Eimeria spp. oocysts were found in the Aysén and Magallanes regions. There was no evidence of F. hepatica during sample examination. Differences in parasitism were detected between seasons in Aysén and Magallanes (p≤0.05). Conclusions. Aysén and Magallanes regions showed a relatively higher prevalence and diversity of parasites than the Ñuble region. This could be related to differences in density of huemul populations and livestock in each region. Further parasitological surveys in huemul populations from central and southern Chile should be performed in the future. Studies involving the relationship between the huemul and livestock and the potential inter- and intraspecific transmission of parasites are also required.RESUMEN Objetivo. Identificar parásitos en heces del huemul (Hippocamelus bisulcus) presente en áreas naturales protegidas del centro y sur de Chile y evaluar diferencias en la prevalencia de parásitos entre regiones y estaciones del año. Materiales y métodos. 200 muestras de heces de huemul fueron colectadas de distintas localidades de las regiones de Ñuble, Aysén y Magallanes a lo largo de todas las estaciones entre los años 2006 y 2008. Las muestras fueron analizadas utilizando las técnicas de flotación y sedimentación, para ser posteriormente observadas en el microscópio con el objetivo de detectar parásitos. Adicionalmente, se analizaron 124 de estas muestras para determinar la presencia de Fasciola hepatica. Resultados. El 38.0% (n = 76/200) de las muestras analizadas fueron positivas a algún parásito, observándose una prevalencia de 11.8% (n = 2/17) en Ñuble, 22.8% (n = 28/123) en Aysén y un 76.7% (n=46/60) en Magallanes. En Ñuble se encontraron huevos de Moniezia sp., mientras que en Aysén y Magallanes se identificaron huevos tipo Estrongílido, Nematodirus sp. y ooquistes de Eimeria spp. No se evidenció F. hepatica en las muestras analizadas. Se detectan diferencias de parasitismo entre las estaciones (p≤0.05) en Aysén y Magallanes. Conclusiones. La diferencia en la prevalencia y diversidad parasitaria entre regiones incluidas en este estudio pueden estar relacionadas con la disimilitud en la densidad poblacional de huemules y la masa ganadera de cada región. Es necesario continuar con monitoreos parasitológicos en poblaciones de huemul en Chile sur y central y estudiar la relación de esta especie con el ganado y la posible transmisión inter- e intraespecífica de parásitos