448 research outputs found

    Early Effects Of Estrogen On The Rat Ventral Prostate.

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    Complex interactions between androgen and estrogen (E2) regulate prostatic development and physiology. We analyzed the early effects of a high single dose of E2 (25 mg/kg body weight) and castration (separately or combined) on the adult 90-day-old male Wistar rat ventral prostate. Androgen levels, prostate weight, and the variation in the relative and absolute volume of tissue compartments and apoptotic indices were determined for 7 days. Castration and exogenous E2 markedly reduced ventral prostate weight (about 50% of the control), with a significant reduction in the epithelial compartment and increased stroma. The final volume of the epithelium was identical at day 7 for all treatments (58.5% of the control). However, E2 had an immediate effect, causing a reduction in epithelial volume as early as day 1. An increase in smooth muscle cell volume resulted from the concentration of these cells around the regressing epithelium. The treatments resulted in differential kinetics in epithelial cell apoptosis. Castration led to a peak in apoptosis at day 3, with 5% of the epithelial cells presenting signs of apoptosis, whereas E2 caused an immediate increase (observed on day 1) and a sustained (up to day 7) effect. E2 administration to castrated rats significantly increased the level of apoptosis by day 3, reaching 9% of the epithelial cells. The divergent kinetics between treatments resulted in the same levels of epithelial regression after 7 days (approximately 30% of control). These results show that E2 has an immediate and possibly direct effect on the prostate, and anticipates epithelial cell death before reducing testosterone to levels as low as those of castrated rats. In addition, E2 and androgen deprivation apparently cause epithelial cell death by distinct and independent pathways.38487-9

    Uso de la inmunohistoquímica como herramienta epidemiológica para el diagnóstico de rabia bovina a partir de casos no conclusivos

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    Objetivo. Identificar el virus de la rabia en casos de encefalitis bovina a partir de muestras archivadas en el laboratorio sin diagnóstico conclusivo. Materiales y métodos. Doce muestras de cerebro bovino sospechosas de rabia, fueron procesadas por la técnica de inmunoperoxidasa indirecta, usando anticuerpos policlonales contra el agente viral. Resultados. Se demostró la presencia de antígenos virales en tres casos en forma de agregados pequeños en el citoplasma de las neuronas, con un patrón de forma redonda u oval y un número variable de corpúsculos de inclusión viral. Se discute sobre la importancia de los resultados en Colombia, la utilidad de la técnica en las difíciles condiciones de envío de muestras al laboratorio, además la posible relación de los casos negativos con herpesvirus bovino 5. Conclusiones. La utilización de la técnica de inmunohistoquímica para demostrar antígenos del virus rábico en encéfalos bovinos fijados en formol, puede ayudar en el perfeccionamiento del mapa epidemiológico de la enfermedad de la rabia en Colombia y puede disminuir el alto subdiagnóstico de otras enfermedades que afectan el sistema nervioso de los bovinos

    Tailoring Organic-Organic Poly(vinylpyrrolidone) Microparticles and Fibers with Multiwalled Carbon Nanotubes for Reinforced Composites

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    Polymeric-based microparticles and fibers are tailorable for a wide range of common industrial and biomedical applications, while multiwalled carbon nanotubes (MWCNTs) are among the most useful macromolecules based on their outstanding electronic, mechanical, and optical properties at the nanoscale. If one combines these nanostructures with various polymeric precursors, their range of potential applications becomes even greater. One of the simplest and most affordable methods for fabricating micro- and nanostructures is electrospinning. Herein we demonstrate how MWCNTs may be used to produce tailor-made organic-organic poly(vinylpyrrolidone) (PVP) microparticles and fibers via electrospinning by studying their structural, vibrational, rheological, and mechanical properties' dependence on their solvent (ethanol (EtOH) or dimethylformamide (DMF)) and resulting morphology. Specifically, we find clear differences in morphologies from perfectly spherical and isolated microparticles to fibers mats, or a combination of fibers with entangled beads, with solvent type and concentration. On the basis of our findings, we propose that the mechanism governing the shape and size of the particles is a competition between the solvent's surface tension, dielectric constant, and viscoelastic properties. We show, based on both our experimental results and density functional theory (DFT) calculations, that OH functionalization of the MWCNTs is essential for achieving high PVP coverages and promoting the stability of the resulting PVP/MWCNT nanocomposite. Finally, by fabricating PVP/MWCNT fiber mats, we demonstrate that low concentrations (0.01-0.1 wt %) of MWCNTs led to a qualitative improvement (â250%) in the resulting mechanical properties, i.e., a reinforced composite. These results show how by controlling the solvent's dielectric constant, surface tension, and polymer concentration, one may produce tailor-made polymeric nanomaterials in combination with other organic/inorganic nanoparticles, i.e., silver, gold, or carbon allotropes, for next-generation applications

    Environmentally friendly processing of Laminaria ochroleuca for soft food applications with bioactive properties

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    Dehydrated Laminaria ochroleuca was processed by autohydrolysis with compressed hot water to extract bioactive compounds. Both the whole algae and individual fractions obtained (solid residue and liquor) were characterised to assess its functional properties for future innovative food applications. Purée-like systems were developed by combining ultrasonic and thermal technologies to maximise the antioxidant capacity and were evaluated by determining colour, texture, rheology, syneresis and the presence of bioactive compounds. Overall, the obtained results indicated that L. ochroleuca is a valuable resource that can be used as a whole or taking advantage of its bioactive fractions, in a concept of circular economy and sustainabilityinfo:eu-repo/semantics/publishedVersio

    Diabetes insípida de origen central secundario a hipofisitis. Reporte de 2 casos

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    La diabetes insípida es una entidad poco frecuente caracterizada por una deficiencia en la secreción de la hormona antidiurética (ADH) o resistencia a su acción, lo que genera una alteración para concentrar la diuresis y, en consecuencia, ocasiona altos volúmenes de orina diluida. La diabetes insípida puede ser de origen renal o central, y esta última es la más frecuente. La poliuria y polidipsia son las expresiones clínicas predominantes en respuesta a la incapacidad del paciente de mantener un equilibrio hídrico. Las causas de la diabetes insípida central son diversas, tales como después de la cirugía pituitaria, adenoma hipofisario, encefalopatía isquémica, trauma, hipofisitis, origen genético o idiopática. La hipofisitis primaria es una entidad rara, caracterizada por un proceso inflamatorio de la glándula hipofisaria, que puede comprometer la función de la hipófisis anterior o posterior. A continuación, se presentan 2 casos de pacientes con diabetes insípida secundaria a hipofisitis estudiadas ambulatoriamente y de manera intrahospitalaria

    Influence of temperament on performance and carcass quality of commercial Brahman steers in a Colombian tropical grazing system

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    Temperament is defined as individual behavioral responses to potentially fear-eliciting or challenging situations related to human presence and handling. A total of 190 steers of commercial Zebu Brahman (Bos indicus) were used in this study, selected when they were between 10 and 11 months of age, fattened for 24 months (720 days) and slaughtered between 34 and 35 months of age. Using a temperament index (based on two tests: chute and exit score), animals were classified as calm, restless, or nervous. In general, calm animals had a longer carcass, a higher slaughter and fasting weight, and a normal pH24 (<5.7). However, carcass yield was significantly higher in nervous than in restless animals, but did not differ from that of calm steers. It is important to note that these results were obtained under experimental conditions, therefore, effects could have a greater impact on carcass quality under commercial conditions. © 2022 The Author

    Protein network prediction and topological analysis in Leishmania major as a tool for drug target selection

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    <p>Abstract</p> <p>Background</p> <p>Leishmaniasis is a virulent parasitic infection that causes a worldwide disease burden. Most treatments have toxic side-effects and efficacy has decreased due to the emergence of resistant strains. The outlook is worsened by the absence of promising drug targets for this disease. We have taken a computational approach to the detection of new drug targets, which may become an effective strategy for the discovery of new drugs for this tropical disease.</p> <p>Results</p> <p>We have predicted the protein interaction network of <it>Leishmania major </it>by using three validated methods: PSIMAP, PEIMAP, and iPfam. Combining the results from these methods, we calculated a high confidence network (confidence score > 0.70) with 1,366 nodes and 33,861 interactions. We were able to predict the biological process for 263 interacting proteins by doing enrichment analysis of the clusters detected. Analyzing the topology of the network with metrics such as connectivity and betweenness centrality, we detected 142 potential drug targets after homology filtering with the human proteome. Further experiments can be done to validate these targets.</p> <p>Conclusion</p> <p>We have constructed the first protein interaction network of the <it>Leishmania major </it>parasite by using a computational approach. The topological analysis of the protein network enabled us to identify a set of candidate proteins that may be both (1) essential for parasite survival and (2) without human orthologs. These potential targets are promising for further experimental validation. This strategy, if validated, may augment established drug discovery methodologies, for this and possibly other tropical diseases, with a relatively low additional investment of time and resources.</p

    Establishing a governance threshold in small-scale fisheries to achieve sustainability

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    The lack of effective governance is a major concern in small-scale fisheries. The implementation of governance that encompasses the three pillars of sustainability (social, economic, and ecological) is still a worldwide challenge. We examined nine stalked barnacle fisheries (Pollicipes pollicipes) across Southwest Europe to better understand the relationship between governance elements and sustainability. Our results show that nested spatial scales of management, the access structure, co- management, and fisher’s participation in monitoring and surveillance promote sustainability. However, it is not the mere presence of these elements but their level of implementation that drives sustainability. Efforts should be placed in the accomplishment of a minimum combination of local scales of management, access rights through individual quotas, instructive-consultative co- management and functional participation. Surpassing this threshold in future governance structures will start to adequately promote social, economic and ecologically sustainability in small-scale fisheries
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