La exclusión, un tema transversal, un reto para todos

La exclusión, un tema transversal, un reto para todo

Mediación Social en el Consumo de Alimentos en Ovinos: Condicionamiento Jerárquico por Edad como Herramienta para Controlar la Dieta en Rumiantes No Emparentados en Pastoreo

Conditioning of food consumption induced by Lithium Chloride (LiCl) treatment has been reported in different animal species. In ruminants, older animals are capable of transferring selective food aversion to the youngers. The objetive of this study was to determine whether food aversion in adult sheep induced by LiCl can be transmitted to non-relative lambs. Twelve animals, four adult ewes and eight lambs were used. Three ewes were conditioned with LiCl 200 mg/kg BW (orally) to avoid concentrate consumption, while the other one acted as a control. Food consumption of lambs was recorded prior to the trial, to define preconditioned basal consumption. After that, animals were assigned to four groups of one sheep and two lambs each, whose food consumption was recorded for a 20-day period in lairage. Concentrate consumption decreased significantly in those lambs that were grouped with conditioned ewes (p < .01). These results suggest that hierarchical conditioning in sheep would be a useful tool to control diet and consumption of potentially harmful food like toxic plants.La aversión alimenticia inducida por la administración de Cloruro de Litio (LiCl) ha sido descripta y utilizada en diferentes especies animales para condicionar el consumo de alimentos. En rumiantes durante el pastoreo en grupo los animales de mayor edad son los encargados de transferir el comportamiento de selección de alimentos a los más jóvenes. El objetivo del presente trabajo fue determinar si la aversión alimenticia inducida con LiCl en ovejas adultas es transmitida a corderos no emparentados. Se utilizaron 12 ovinos, 4 ovejas adultas y 8 corderos. Luego de confirmar el consumo de ración comercial por parte de las ovejas, 3 fueron condicionadas con LiCl 200 mg/kg PV (oralmente), usando 1 como control. Se formaron 4 tríos de 1 oveja con 2 corderos, midiendo previamente el consumo de ración de los últimos, registrando la variación del consumo luego de 20 días de convivencia en estabulación. Luego de este período los corderos agrupados con ovejas condicionadas disminuyeron el consumo de ración significativamente (p < .01). El condicionamiento jerárquico en ovinos parece ser una herramienta útil para controlar la dieta y el consumo de alimentos no deseados, tales como plantas tóxicas en condiciones de pastoreo a campo natural

Lipomatous tumour in the endangered toad <i>Melanophryniscus montevidensis</i>(Anura: Bufonidae) from Uruguay

We communicate the finding of a subcutaneous neoplasia in a female specimen of the toad Melanophryniscus montevidensis (Bufonidae) from Uruguay. The lesion extended from the cephalic to the abdominal region, and both gross and microscopic features were typical of lipomas. This is to our knowledge the fourth case reported in amphibians.Asociación Herpetológica Argentin

Aggregative behaviour in the fossorial lizard Amphisbaena darwinii (Squamata, Amphisbaenidae)

Amphisbaena is a species-rich genus widely distributed in the Neotropics, from Middle America to central-eastern Argentina and Uruguay (Gans, 2005). The natural history of these fossorial Squamata has been scarcely studied, although several species are common in varied biomes. One of these poorly known forms is Amphisbaena darwinii Duméril & Bibron 1839 although being widely distributed in southern and central Uruguay (Gans, 1966). This species is a common inhabitant of urban and suburban areas in this country, including gardens and backyards where it can be easily found under rocks, rotten logs, and a varied kind of human-made refuges (pers. obs.). We present herein observations on A. darwinii made from 2008 to 2011 as part of herpetofaunal inventories in southern Uruguay.Asociación Herpetológica Argentin

Jejunum-derived NF-κB reporter organoids as 3D models for the study of TNF-alpha-induced inflammation

Inflammation is an important process for epithelial barrier protection but when uncontrolled, it can also lead to tissue damage. The nuclear factor-kappa light chain enhancer of activated B cells (NF-κB) signaling pathway is particularly relevant in the intestine, as it seems to play a dual role. Whereas NF-κB protects intestinal epithelium against various noxious stimuli, the same pathway mediates intestinal inflammatory diseases by inducing pro-inflammatory gene expression. The availability of appropriate in vitro models of the intestinal epithelium is crucial for further understanding the contribution of NF-κB in physiological and pathological processes and advancing in the development of drugs and therapies against gut diseases. Here we established, characterized, and validated three-dimensional cultures of intestinal organoids obtained from biopsies of NF-κB-RE-Luc mice. The NF-κB-RE-Luc intestinal organoids derived from different intestine regions recreated the cellular composition of the tissue and showed a reporter responsiveness similar to the in vivo murine model. When stimulated with TNF-α, jejunum-derived NF-κB-RE-Luc-reporter organoids, provided a useful model to evaluate the anti-inflammatory effects of natural and synthetic compounds. These reporter organoids are valuable tools to explore the epithelial TNF-α-induced NF-κB contribution in the small intestine, being a reliable alternative method while helping to reduce the use of laboratory animals for experimentation.Agencia Nacional de Investigación e InnovaciónFOCEM (MERCOSUR Structural Convergence Fund

Increased caspase-3 immunoexpression and morphology alterations in oenocytes and trophocytes of Apis mellifera larvae induced by toxic secretion of Epormenis cestri

Toxic honeydew produced by Flatidae Epormenis cestri in Uruguay has been shown to cause among honeybees (Apis mellifera) colonies a massive larva death called “River disease”, but the intrinsic mechanisms are still unknown. Because fat body cells, oenocytes and trophocytes, are known to regulated larvae metabolism, and to be affected by xenobiotics, we tested whether apoptosis of these cells can be an underlying cause of larvae death. Ten colonies were divided into two groups and fed with common honey or toxic honeydew obtained from colonies affected by “River disease”. Five-day-old larvae were collected and processed for histology and immunohistochemistry for caspase-3. The area, diameter, and immunostaining area in oenocytes and trophocytes were measured. The oenocyte and trophocyte cellular area decreased in the treated group (p=0.002; p<0.001 respectively) compared to the control group. The diameter of oenocytes (p=0.0002) and trophocytes (p<0.0001) decreased in the treated group. Caspase-3 was detected in cytoplasm in the control group but in the cytoplasm and nucleus in the treated group. The caspase-3 immunostaining area increased in oenocytes (p<0.002) and trophocytes (p<0.0001) of the treated group. The ingestion of toxic honeydew altered the morphology, localization and immunoexpression of caspase-3 in fat body cells, which suggests that the deregulation of the apoptotic mechanism affected the normal development in A. mellifera larvae

A novel pathogenic mechanism for cerebellar lesions produced by Solanum bonariense in cattle

Intoxication with Solanum bonariense in cattle causes cerebellar cortical degeneration with perikaryal vacuolation, axonal swelling, and death primarily of Purkinje cells, with accumulation of electron-dense residual storage bodies in membrane-bound vesicles. The pathogenesis of this disease is not fully understood. Previously, we proposed that inhibition of protein synthesis in Purkinje cells among other altered metabolic pathways could lead to cytoskeletal alterations, subsequently altering cell-specific axonal transport. In the present study, immunohistochemical and histochemical methods were used to identify neuronal cytoskeletal alterations and axonal loss, demyelination, and astrogliosis in the cerebellum of intoxicated bovines. Samples of cerebellum from 3 natural and 4 experimental cases and 2 control bovines were studied. Immunoreactivity against neurofilament (NF)-200KDa confirmed marked loss of Purkinje neurons, and phospho-NF protein, β-tubulin, and affinity reaction against phalloidin revealed an altered perikaryal distribution of neuronal cytoskeletal proteins in the remaining Purkinje cells in intoxicated cattle. Reactive astrogliosis in every layer of the cerebellar cortex was also observed with anti–glial fibrillary acidic protein immunohistochemistry. In affected cattle, demyelination and axonal loss in the cerebellar white matter, as well as basket cell loss were demonstrated with Klüver–Barrera and Bielschowsky stains, respectively. Based on these results, we propose that neuronal cytoskeletal alterations with subsequent interference of the axonal transport in Purkinje cells may play a relevant role in the pathogenesis of this neurodegenerative disorder, and also that demyelination and axonal loss in the cerebellar white matter, as well as astrogliosis in the gray matter, likely occur secondarily to Purkinje cell degeneration and death.Facultad de Ciencias Veterinaria

A novel pathogenic mechanism for cerebellar lesions produced by Solanum bonariense in cattle

Intoxication with Solanum bonariense in cattle causes cerebellar cortical degeneration with perikaryal vacuolation, axonal swelling, and death primarily of Purkinje cells, with accumulation of electron-dense residual storage bodies in membrane-bound vesicles. The pathogenesis of this disease is not fully understood. Previously, we proposed that inhibition of protein synthesis in Purkinje cells among other altered metabolic pathways could lead to cytoskeletal alterations, subsequently altering cell-specific axonal transport. In the present study, immunohistochemical and histochemical methods were used to identify neuronal cytoskeletal alterations and axonal loss, demyelination, and astrogliosis in the cerebellum of intoxicated bovines. Samples of cerebellum from 3 natural and 4 experimental cases and 2 control bovines were studied. Immunoreactivity against neurofilament (NF)-200KDa confirmed marked loss of Purkinje neurons, and phospho-NF protein, β-tubulin, and affinity reaction against phalloidin revealed an altered perikaryal distribution of neuronal cytoskeletal proteins in the remaining Purkinje cells in intoxicated cattle. Reactive astrogliosis in every layer of the cerebellar cortex was also observed with anti–glial fibrillary acidic protein immunohistochemistry. In affected cattle, demyelination and axonal loss in the cerebellar white matter, as well as basket cell loss were demonstrated with Klüver–Barrera and Bielschowsky stains, respectively. Based on these results, we propose that neuronal cytoskeletal alterations with subsequent interference of the axonal transport in Purkinje cells may play a relevant role in the pathogenesis of this neurodegenerative disorder, and also that demyelination and axonal loss in the cerebellar white matter, as well as astrogliosis in the gray matter, likely occur secondarily to Purkinje cell degeneration and death.Facultad de Ciencias Veterinaria

Informe final del proyecto: caracterización de las alteraciones neurofisiológicas, histopatológicas e inmunohistoquímicas ocasionadas por la infección natural por distemper en caninos: evaluación de desmielinización y neurodegeneración en asociación con los signos neurológicos

El virus del Distemper canino (DC) causa una enfermedad de gran letalidad en cánidos, cursando con trastornos respiratorios, entéricos, dermatológicos y neurológicos. En el sistema nervioso (SN) provoca rigidez de nuca, déficits visuales, signos vestibulares, cerebelosos, paresia, paraplejia, convulsiones y mioclonias. Las encefalitis por DC se clasifican en: polioencefalitis y leucoencefalitis desmielinizante (más frecuente). Aunque la desmielinización no es la única responsable de los signos neurológicos, es característica del DC, presentándose 3 formas: aguda, subaguda y crónica. Estas lesiones empiezan a las 3 semanas post-infección, y pese a que inicialmente su estudio se centró en la alteración de los oligodendrocitos, hoy se sabe que son los astrocitos el “blanco” principal del virus, ocasionando la desmielinización central por la alteración celular del entorno cercano, y aunque se considera que puede deberse a un fenómeno de autoinmunidad, aún no se han dilucidado las causas. Dada la complejidad de su patogenia, resulta crucial la identificación de marcadores biológicos que contribuyan a su diagnóstico, evolución clínica, al desarrollo de metodologías que mejoren su diagnóstico (electrofisiológico, molecular y anatomo-patológico). En el presente proyecto se desarrollaron estudios clínicos, hematológicos, electrofisiológicos y moleculares en caninos domésticos infectados naturalmente con DC, recibidos en la Unidad de Neurología (FVET-Udelar). Estos estudios, en su conjunto, nos han permitido, además de la implementación de este proyecto, la consolidación de un equipo multidisciplinario para abordar integralmente esta enfermedad, ayudando a establecer diagnósticos certeros y ajustar los pronósticos de la discapacidad en los perros recuperados, mientras que en los casos de mal pronóstico, que mueran espontáneamente, o que se recomiende su eutanasia por motivos humanitarios, se estandarizaron técnicas de autopsia, toma de muestras, estudios histopatológicos, inmunohistoquímicos y moleculares, los que nos permitirán continuar profundizando en la etiopatogenia de esta enfermedad, usando las herramientas puestas a punto en la Unidad Patología de la FVET-Udelar.Agencia Nacional de Investigación e Innovació