282 research outputs found

    Síndrome de intestino corto en niños: actualidades en su diagnóstico y manejo

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    ResumenEl síndrome de intestino corto (SIC) se refiere a la suma de alteraciones funcionales que resultan de una reducción crítica en la longitud del intestino, y que en ausencia de un tratamiento adecuado se manifiestan con diarrea crónica, deshidratación crónica, desnutrición, pérdida de peso, deficiencia de nutrimentos y electrolitos, así como falla para crecer que se presenta con mayor frecuencia durante el periodo neonatal. El objetivo de este artículo es realizar una revisión de la literatura médica sobre la definición, las causas más frecuentes de SIC así como entender la fisiopatología, los factores pronósticos y tratamiento.Se realizó una búsqueda de artículos en PubMed, considerando la información existente en niños con SIC de 20 años hasta la fecha, utilizando las palabras clave “síndrome de intestino corto”. De un total de 784 artículos potenciales, se realizó una selección de 82 artículos donde realizamos la revisión de la literatura médica. Los pacientes con SIC son todo un reto para su tratamiento, por lo que se debe establecer un manejo multidisciplinario enfocado en mantener un soporte nutricional óptimo que cubra las necesidades para crecimiento, desarrollo y asimismo, disminuir al máximo la presencia de complicaciones a corto, mediano y largo plazo. El diagnóstico y manejo de un niño con SIC, implica un equipo de profesionales expertos en el manejo gastroenterológico, pediátrico y nutricional. El pronóstico del niño estará en función al manejo oportuno, así como longitud de la resección intestinal y presencia o no de válvula ileocecal.AbstractShort bowel syndrome (SBS) refers to the sum of the functional alterations that are the result of a critical reduction in the length of the intestine, which in the absence of adequate treatment, presents as chronic diarrhea, chronic dehydration, malnutrition, weight loss, nutriment and electrolyte deficiency, along with a failure to grow that is present with greater frequency during the neonatal period. The aim was to carry out a review of the literature encompassing the definition and the most frequent causes of SBS, together with an understanding of its physiopathology, prognostic factors, and treatment.An Internet search of PubMed articles was carried out for the existing information published over the last 20 years on SBS in children, using the keywords “short bowel syndrome”. From a total of 784 potential articles, 82 articles were chosen for the literature review. The treatment of patients presenting with SBS is quite a challenge and therefore it is necessary to establish multidisciplinary management with a focus on maintaining optimal nutritional support that covers the necessities of growth and development and at the same time provides a maximum reduction of short, medium, and long-term complications. The diagnosis and treatment of a child with SBS require a team of professionals that are experts in gastroenterologic, pediatric, and nutritional management. The outcome for the child will be directly related to opportune management, as well as to the length of the intestinal resection and the presence or absence of the ileocecal valve

    X-ray determination of compressive residual Stresses in spring steel generated by high-speed water Quenching

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    Automotive components manufacturers use the 5160 steel in leaf and coil springs. The industrial heat treatment process consists in austenitizing followed by the oil quenching and tempering process. Typically, compressive residual stresses are induced by shot peening on the surface of automotive springs to bestow compressive residual stresses that improve the fatigue resistance and increase the service life of the parts after heat treatment. In this work, a high-speed quenching was used to achieve compressive residual stresses on the surface of AISI/SAE 5160 steel samples by producing high thermal gradients and interrupting the cooling in order to generate a case-core microstructure. A special laboratory equipment was designed and built, which uses water as the quenching media in a high-speed water chamber. The severity of the cooling was characterized with embedded thermocouples to obtain the cooling curves at different depths from the surface. Samples were cooled for various times to produce different hardened case depths. The microstructure of specimens was observed with a scanning electron microscope (SEM). X-ray diffraction (XRD) was used to estimate the magnitude of residual stresses on the surface of the specimens. Compressive residual stresses at the surface and sub-surface of about -700 MPa were obtained.Peer ReviewedPostprint (published version

    Is ultra-violet radiation the main force shaping molecular evolution of varicella-zoster virus?

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    <p>Abstract</p> <p>Background</p> <p>Varicella (chickenpox) exhibits a characteristic epidemiological pattern which is associated with climate. In general, primary infections in tropical regions are comparatively less frequent among children than in temperate regions. This peculiarity regarding varicella-zoster virus (VZV) infection among certain age groups in tropical regions results in increased susceptibility during adulthood in these regions. Moreover, this disease shows a cyclic behavior in which the number of cases increases significantly during winter and spring. This observation further supports the participation of environmental factors in global epidemiology of chickenpox. However, the underlying mechanisms responsible for this distinctive disease behavior are not understood completely. In a recent publication, Philip S. Rice has put forward an interesting hypothesis suggesting that ultra-violet (UV) radiation is the major environmental factor driving the molecular evolution of VZV.</p> <p>Discussion</p> <p>While we welcomed the attempt to explain the mechanisms controlling VZV transmission and distribution, we argue that Rice's hypothesis takes lightly the circulation of the so called "temperate VZV genotypes" in tropical regions and, to certain degree, overlooks the predominance of such lineages in certain non-temperate areas. Here, we further discuss and present new information about the overwhelming dominance of temperate VZV genotypes in Mexico regardless of geographical location and climate.</p> <p>Summary</p> <p>UV radiation does not satisfactorily explain the distribution of VZV genotypes in different tropical and temperate regions of Mexico. Additionally, the cyclic behavior of varicella does not shown significant differences between regions with different climates in the country. More studies should be conducted to identify the factors directly involved in viral spreading. A better understanding of the modes of transmissions exploited by VZV and their effect on viral fitness is likely to facilitate the implementation of preventive measures for disease control.</p

    Successful pharmaceutical-grade streptozotocin (STZ)-induced hyperglycemia in a conscious tethered baboon (Papio hamadryas) model

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    Background Non-human primate (NHP) diabetic models using chemical ablation of b-cells with STZ have been achieved by several research groups. Chemotherapeutic STZ could lead to serious adverse events including nephrotoxicity, hepatotoxicity, and mortality. Methods We implemented a comprehensive therapeutic strategy that included the tether system, permanent indwelling catheter implants, an aggressive hydration protocol, management for pain with IV nubain and anxiety with IV midazolam, moment-by-moment monitoring of glucose levels post-STZ administration, and continuous intravenous insulin therapy. Results A triphasic response in blood glucose after STZ administration was fully characterized. A dangerous hypoglycemic phase was also detected in all baboons. Other significant findings were hyperglycemia associated with low levels of plasma leptin, insulin and C-peptide concentrations, hyperglucagonemia, and elevated non-esterified fatty acids (NEFA) concentrations. Conclusions We successfully induced frank diabetes by IV administering a single dose of pharmaceutical-grade STZ safely and without adverse events in conscious tethered baboons

    Animal welfare during transport and slaughter of beef cattle

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    Objective: To review the way transport and stun cattle affect animal welfare. Approach: During the transport of cattle to slaughter plants, many factors affect animal welfare, such as travel time, stress and load density. Besides, stunning might comply with animal welfare guidelines, which different protocols such as Welfare Quality® establish.Objective: To review how transport and stunning of cattle affect animal welfare. Approach: During the transport of beef cattle to slaughter plants, several factors affect animal welfare, such as travel time, stress, and load density. Additionally, the correct stunning of cattle helps comply with the animal welfare guidelines established by different protocols such as Welfare Quality®. Study limitations/Implications: Meat quality is affected by several factors, being of utmost importance the way animals are transported to the slaughterhouse, and they are stunned. Therefore, it is critical to perform these stages properly to obtain good quality meat; besides, it is a welfare issue. Conclusions: It is critical to comply with transport and slaughter procedures that guarantee good beef meat quality and ensure animal welfare to avoid stress in cattle as possible

    Interactions between cytoplasmic and nuclear genomes confer sex‐specific effects on lifespan in Drosophila melanogaster

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    Genetic variation outside of the cell nucleus can affect the phenotype. The cytoplasm is home to the mitochondria, and in arthropods often hosts intracellular bacteria such as Wolbachia. Although numerous studies have implicated epistatic interactions between cytoplasmic and nuclear genetic variation as mediators of phenotypic expression, two questions remain. Firstly, it remains unclear whether outcomes of cyto-nuclear interactions will manifest differently across the sexes, as might be predicted given that cytoplasmic genomes are screened by natural selection only through females as a consequence of their maternal inheritance. Secondly, the relative contribution of mitochondrial genetic variation to other cytoplasmic sources of variation, such as Wolbachia infection, in shaping phenotypic outcomes of cyto-nuclear interactions remains unknown. Here, we address these questions, creating a fully crossed set of replicated cyto-nuclear populations derived from three geographically distinct populations of Drosophila melanogaster, measuring the lifespan of males and females from each population. We observed that cyto-nuclear interactions shape lifespan and that the outcomes of these interactions differ across the sexes. Yet, we found no evidence that placing the cytoplasms from one population alongside the nuclear background of others (generating putative cyto-nuclear mismatches) leads to decreased lifespan in either sex. Although it was difficult to partition mitochondrial from Wolbachia effects, our results suggest at least some of the cytoplasmic genotypic contribution to lifespan was directly mediated by an effect of sequence variation in the mtDNA. Future work should explore the degree to which cyto-nuclear interactions result in sex differences in the expression of other components of organismal life history
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