1,556 research outputs found

    Differential expression of microRNAs in bovine papillomavirus type 1 transformed equine cells

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    Bovine papillomavirus (BPV) types 1 and 2 play an important role in the pathogenesis of equine sarcoids (ES), the most common cutaneous tumour affecting horses. MicroRNAs (miRNAs), small non-coding RNAs that regulate essential biological and cellular processes, have been found dysregulated in a wide range of tumours. The aim of this study was to identify miRNAs associated with ES. Differential expression of miRNAs was assessed in control equine fibroblasts (EqPalFs) and EqPalFs transformed with the BPV-1 genome (S6-2 cells). Using a commercially available miRNA microarray, 492 mature miRNAs were interrogated. In total, 206 mature miRNAs were differentially expressed in EqPalFs compared with S6-2 cells. Aberrant expression of these miRNAs in S6-2 cells can be attributed to the presence of BPV-1 genomes. Furthermore, we confirm the presence of 124 miRNAs previously computationally predicted in the horse. Our data supports the involvement of miRNAs in the pathogenesis of ES

    The lemniscal–cuneate recurrent excitation is suppressed by strychnine and enhanced by GABAA antagonists in the anaesthetized cat

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    [Abstract] In the somatosensory system, cuneolemniscal (CL) cells fire high frequency doublets of spikes facilitating the transmission of sensory information to diencephalic target cells. We studied how lemniscal feedback affects ascending transmission of cutaneous neurons of the middle cuneate nucleus. Electrical stimulation of the contralateral medial lemniscus and of the skin at sites evoking responses with minimal threshold induced recurrent activation of CL cells at a latency of 1–3.5 ms. The lemniscal feedback activation was suppressed by increasing the stimulating intensity at the same sites, suggesting recurrent-mediated lateral inhibition. The glycine antagonist strychnine blocked the recurrent excitatory responses while GABAA antagonists uncovered those obscured by stronger stimulation. CL cells sharing a common receptive field (RF) potentiate one another by recurrent activation and disinhibition, the disinhibition being produced by serial interactions between glycinergic and GABAergic interneurons. Conversely, CL cells with different RFs inhibit each other through recurrent GABA-mediated inhibition. The lemniscal feedback would thus enhance the surround antagonism of a centre response by increasing the spatial resolution and the transmission of weak signals.Consejo Interinstitucional de Ciencia y Tecnología; PM99-002

    Modeling in TRNSYS of a single effect evaporation system powered by a Rankine cycle

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    The paper presents an analysis of a Single Effect Evaporation (SEE) system as a pre-study to the feasibility of concentrated solar power plants (CSP) powering desalination units for cogeneration of water and electricity. An algorithm to model a SEE system in steady-state operation was made and is described in this work. This algorithm was implemented in TRNSYS environment, and a simple analysis was conducted of a SEE system powered by a Rankine cycle used in CSP plants

    La corteza cerebral modula la transmisión cutánea a través de los núcleos de los cordones posteriores

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    The mechanisms used by the cerebral cortex to modulate the cutaneous information at prethalamic level have been scarcely studied. This article reviews experimental evidence leading to a better understanding of this issue at the level of the cuneate nucleus (Burdach nucleus). Development. The primary afferents and the corticocuneate fibers make synaptic contact with cuneothalamic neurons and with inhibitory interneurons in the middle cuneate nucleus. By stimulating the skin at different places while recording the cuneothalamic intracellular activity in anaesthetized animals with the cortex intact, with the cortex pharmacologically inactivated, or in absence of a cerebral cortex it was possible to ascertain the functional role of the corticocuneate fibers. The primary afferents activated by stimulating a particular zone of the skin induce monosynaptic excitation on a group of cuneothalamic cells at the same time at which inhibit, through intranuclear interneurons, neighboring cuneothalamic cells with unmatched receptive fields. Similarly, the corticocuneate cells receiving information from the stimulated skin further increase the excitation of the cuneothalamic neurons with matched receptive fields while inhibiting others with unmatched fields. The cortex exaggerates an excited center surrounded by an inhibited periphery thus increasing the tactile discrimination both spatially and temporally which is essential for exploratory and manipulative purpose

    Nuestra experiencia con la enfermedad de Freiberg

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    Analizamos una serie de 34 pacientes, 9 varones y 25 mujeres, con enfermedad de Freiberg, detallando su localización y grado evolutivo en el momento del diagnóstico. Clínicamente la severidad del cuadro fue muy variable, y con frecuencia discordante con la imagen radiológica. Tan solo en 5 pacientes fue necesario el tratamiento quirúrgico. No se pudo detectar un factor etiológico claro y único, existiendo casos con y sin antecedentes traumáticos. Se describe la evolución radiológica de esta enfermedad. La RMN permite de forma precoz, detectar las anomalías óseas en las fases más iniciales.We analyze a series of 34 patients, 9 males and 25 females, with Freiberg's disease, detailing their location and severity at moment of the diagnosis. Clinically the severity of disease was variable, and frequently discordant with the radiological image. Only in 5 patients was necessary the surgical treatment. There was no etiologic factor clearly found in any of the cases, with and without traumatic precedents. We describe the radiological pattern of this disease. The MRI permits at early stage detection of bone anomalies

    Intracuneate mechanisms underlying primary afferent cutaneous processing in anaesthetized cats

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    [Abstract] The cutaneous primary afferents from the upper trunk and forelimbs reach the medial cuneate nucleus in their way towards the cerebral cortex. The aim of this work was twofold: (i) to study the mechanisms used by the primary afferents to relay cutaneous information to cuneate cuneolemniscal (CL) and noncuneolemniscal (nCL) cells, and (ii) to determine the intracuneate mechanisms leading to the elaboration of the output signal by CL cells. Extracellular recordings combined with microiontophoresis demonstrated that the primary afferent cutaneous information is communicated to CL and nCL cells through AMPA, NMDA and kainate receptors. These receptors were sequentially activated: AMPA receptors participated mainly during the initial phase of the response, whereas kainate- and NMDA-mediated activity predominated during a later phase. The involvement of NMDA receptors was confirmed by in vivo intracellular recordings. The cutaneous-evoked activation of CL cells was decreased by GABA and increased by glycine acting at a strychnine-sensitive site, indicating that glycine indirectly affects CL cells. Two subgroups of nCL cells were distinguished based on their sensitivity to iontophoretic ejection of glycine and strychnine. Overall, the results support a model whereby the primary afferent cutaneous input induces a centre-surround antagonism in the cuneate nucleus by activating (via AMPA, NMDA and kainate receptors) and disinhibiting (via serial glycinergic–GABAergic interactions) a population of CL cells with overlapped receptive fields that at the same time inhibit (via GABAergic cells) other neighbouring CL cells with different receptive fields.Ministerio de Ciencia y Tecnología; BFI 2003-0194

    Lesiones de la articulación tarso-metatarsiana

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    Se presentan 16 casos de fractura-luxación tarso-metatarsiana. El objetivo de este trabajo ha sido la valoración de los resultados finales en este tipo de patología. La etiología del accidente ha sido en 6 ocasiones casual o deportiva, en 5 laboral, en 4 accidente de tráfico y 1 caída de un caballo. Las fractura-luxaciones han sido clasificadas según los criterios de Hardcastle, resultando 3 casos tipo A externo, 6 B externo, 6 B interno y 1 C total. El tratamiento realizado fue mayoritariamente reducción y osteosíntesis con agujas de Kirschner, predominando la reducción abierta. Se ha considerado parámetros radiográficos y clínicos, siguiendo los criterios del Baltimore Painful Foot Store para la valoración de resultados finales, obteniéndose 9 casos excelentes, 4 buenos, 2 reguladores y 1 malo. Se concluye que es fundamental el diagnóstico y tratamiento precoz, considerando básica la reducción anatómica estabilizada con agujas de Kirschner.We report 16 cases of tarsometatarsal fracture-dislocation. The purpose of this work was the assessment of the final outcome of these cases. The etiology was casual or sport injuries in 6 cases, industrial accidents in 5, traffic accidents in 4 and fall off a horse in 1 case. The injuries have been classified according to the Hasrdcastle modified classification, being 3 cases type A external, 6 B internqal and 1 C total. In most cases the treatment was open reduction and internal fixation with Kirschner wires. According to the guidelines of the Balitmore Painful Score for the evaluation of final outcome, there were 9 excellent results, 4 good, 2 fair and 1 poor. We conclude that the best results were obtained in those cases with early diagnose and treatment, looking for an anatomical reduction and fixation with Kirschner wires

    Determining appropriate approaches for using data in feature selection

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    Feature selection is increasingly important in data analysis and machine learning in big data era. However, how to use the data in feature selection, i.e. using either ALL or PART of a dataset, has become a serious and tricky issue. Whilst the conventional practice of using all the data in feature selection may lead to selection bias, using part of the data may, on the other hand, lead to underestimating the relevant features under some conditions. This paper investigates these two strategies systematically in terms of reliability and effectiveness, and then determines their suitability for datasets with different characteristics. The reliability is measured by the Average Tanimoto Index and the Inter-method Average Tanimoto Index, and the effectiveness is measured by the mean generalisation accuracy of classification. The computational experiments are carried out on ten real-world benchmark datasets and fourteen synthetic datasets. The synthetic datasets are generated with a pre-set number of relevant features and varied numbers of irrelevant features and instances, and added with different levels of noise. The results indicate that the PART approach is more effective in reducing the bias when the size of a dataset is small but starts to lose its advantage as the dataset size increases

    Housing in “intramural favelas”: considerations on new forms of urban expansion in contemporary times

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    This paper develops a deeper look into new residential appropriations of space in marginalized areas of a large Brazilian city, while highlighting the subjective importance of housing and its meaning beyond the idea of shelter. Firstly, it presents a brief history of Rio de Janeiro’s favelas – the local version of slums – and its relationship with vacant land over the past 100 years. Then, it explains the value of self-built housing and its contribution to the consolidation of multiple and hybrid territories, highlighting their subjective character. Lastly, it presents a case study called Portelinha, located in a set of favelas known as the Maré Complex, stressing how this mixed occupation has transformed the local urban fabric, leading to the emergence of what is referred to as an “intramural favela”. This phenomenon consists of the self-construction of a smaller-scale set of houses within the walls of a former factory turned into an industrial void in the 1990s. The analysis shows how this housing appropriation is articulated with other activities, especially cultural ones, leading to a diversity of social actors, alliances and conflicts, turning it into a real disputed territory. Cases like this reflect the challenges with which architects and planners need to deal with when working in the unequal urban contexts that are so common in the Global South
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