741 research outputs found

    Nodulin 41, a novel late nodulin of common bean with peptidase activity

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    <p>Abstract</p> <p>Background</p> <p>The legume-rhizobium symbiosis requires the formation of root nodules, specialized organs where the nitrogen fixation process takes place. Nodule development is accompanied by the induction of specific plant genes, referred to as nodulin genes. Important roles in processes such as morphogenesis and metabolism have been assigned to nodulins during the legume-rhizobium symbiosis.</p> <p>Results</p> <p>Here we report the purification and biochemical characterization of a novel nodulin from common bean (<it>Phaseolus vulgaris </it>L.) root nodules. This protein, called nodulin 41 (PvNod41) was purified through affinity chromatography and was partially sequenced. A genomic clone was then isolated via PCR amplification. PvNod41 is an atypical aspartyl peptidase of the A1B subfamily with an optimal hydrolytic activity at pH 4.5. We demonstrate that PvNod41 has limited peptidase activity against casein and is partially inhibited by pepstatin A. A PvNod41-specific antiserum was used to assess the expression pattern of this protein in different plant organs and throughout root nodule development, revealing that PvNod41 is found only in bean root nodules and is confined to uninfected cells.</p> <p>Conclusions</p> <p>To date, only a small number of atypical aspartyl peptidases have been characterized in plants. Their particular spatial and temporal expression patterns along with their unique enzymatic properties imply a high degree of functional specialization. Indeed, PvNod41 is closely related to CDR1, an <it>Arabidopsis thaliana </it>extracellular aspartyl protease involved in defense against bacterial pathogens. PvNod41's biochemical properties and specific cell-type localization, in uninfected cells of the common bean root nodule, strongly suggest that this aspartyl peptidase has a key role in plant defense during the symbiotic interaction.</p

    Efecto coagulante de dos variedades de hoja de coca en muestras de sangre de ratas albinas

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    This investigation evaluates the clotting effect of extracts of two varieties of coca leaves: Erytrhoxylum coca var. Coca and novogranatense Erytrhoxylum var. Truxillense. The aim of the study was to determine the shortest time of clotting of the blood samples of the albin rats. 34 males and female rats were selected to have 3 ml. of blood of each one. The blood samples were distributed in three probes containing: 0,06 ml. of physiological serum (control group), 0,06 ml. extract of E. coca lam var. coca (coca group), and 0,06 ml. of extract E. novogranatense var. truxillense (truxillense group). The clotting time for the control group was of 1,42 (±0.31) min, coca group: 1,38 (±0.26) min, truxillense group 1,83 (±0.55) min. The Anova analysis of the results showed significant differences between groups (p&lt;0.01). The coca group showed the shortest clotting time of all groups. The truxillense group showed an inhibiting clotting effect compared to control group.En la presente investigación se evaluó el efecto coagulante de los extractos de dos variedades de hoja de coca: Erytrhoxylum coca lam var. Coca y Erytrhoxylum novogranatense var. Truxillense. El objetivo fue determinar el menor tiempo de coagulación de muestras de sangre de ratas albinas, tratadas con los extractos. Se seleccionó una muestra de 34 ratas, machos y hembras, a las cuales se le extrajeron 3 ml de sangre a cada una, colocando 1ml de sangre en tubos que contenían 0.06 ml de suero fisiológico (grupo control), 0.06 ml de extracto de E. coca lam var. Coca (grupo coca), y 0.06 ml de extracto E. novogranatense var. Truxillense (grupo truxillense). Los tiempos de coagulación de las muestras del grupo control fue de 1.42 min (±0.31), el grupo coca obtuvo 1.38 min (±0.26) y el grupo truxillense 1.83 min (±0.55). Los promedios fueron comparados con Anova obteniendo diferencias significativas entre los grupos (p&lt;0.01). Se encontró que el grupo coca produjo el menor tiempo de coagulación que los otros dos grupos. El grupo truxillense mostró un efecto inhibidor de la coagulación comparado al grupo control

    Utilidad de la midodrina para el control del síncope vasovagal: ¿la evidencia la recomienda?

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    Introduction: Vasovagal syncope is the main cause of transient loss of consciousness, being an increasingly frequent reason for consultation in pediatrics and adult medicine. Midodrine, a peripherally acting alpha-receptor agonist, is mainly used in the management of orthostatic hypotension. However, it has also been evaluated in vasovagal syncope, with promising results. Objective: To analyze the most recent evidence on the usefulness of midodrine for the control and prevention of vasovagal syncope. Materials and Methods: A literature search was performed using search terms such as "Vasovagal Syncope" and "Midodrine", as well as synonyms, which were combined with Boolean operators, in 5 databases until October 2022. Original studies, systematic reviews and meta-analyses, published in both English and Spanish, were included Results: Randomized controlled trials and systematic reviews and meta-analyses differ slightly between results, but these demonstrate an overall protective effect. The most recent and complete evidence shows that using this agent significantly reduces the probability of positivity when performing the tilt table test and prevents the occurrence of syncopal episodes. Conclusions: Although current evidence on the efficacy of midodrine with respect to the prevention and control of vasovagal syncope is limited, a significant protective effect is observed, reducing the risk of suffering syncopal episode by approximately up to 50%.Introducción: El sincope vasovagal es la principal causa de perdida transitoria de la consciencia, siendo un motivo de consulta cada vez más frecuente en pediatría y medicina del adulto. Midodrina, es un agonista de los receptores alfa, de acción periférica, empleado principalmente en el manejo de la hipotensión ortostática. Sin embargo, ha sido evaluado también en sincope vasovagal, con resultados prometedores. Objetivo: Analizar la evidencia más reciente sobre la utilidad de la midodrina para el control y prevención del sincope vasovagal. Materiales y Métodos: Se realizó una búsqueda bibliográfica utilizando términos de búsqueda como “Vasovagal Syncope” y “Midodrine”, así como sinónimos, que se combinaron con operadores booleanos, en 5 bases de datos, hasta octubre del 2022. Se incluyeron estudios originales, revisiones sistemáticas y meta-análisis, publicados tanto en ingles como español. Resultados: Ensayos controlados aleatorizados y revisiones sistemáticas y meta-análisis difieren ligeramente entre resultados, pero estos demuestran un efecto global protector. La evidencia más reciente y completa, demuestra que utilizar este agente, reduce significativamente la probabilidad de positividad al realizar la prueba de mesa inclinada y, previene la aparición de episodios sincopales. Conclusiones: Aunque la evidencia actual sobre la eficacia de midodrina respecto a la prevención y control del síncope vasovagal es limitada, se observa un efecto protector significativo, reduciendo el riesgo de sufrir episodio sincopal aproximadamente hasta en un 50%

    Matemáticas en contexto

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    El libro compila estrategias didácticas derivadas del programa de formación complementario escritas por instructores técnicos de diferentes regionales del país, describe la forma en que se incorpora el conocimiento matemático en campos específicos de diferentes áreas de formación laboral basado en las teorías didácticas y reflexiones pedagógicas de instructores.The book compiles the didactic strategies derived from the complementary training program by the technical instructors of the regional media of the country, describes the way in which mathematical knowledge is incorporated in the fields of different areas of work training based on theories didactic and pedagogical reflections of instructors.Consideraciones frente al aprendizaje de las matemáticas -- Perspectiva constructivista -- Teoría de las situaciones didácticas -- Modelación matemática -- Mediación tecnológica -- Pensamiento numérico variacional -- Pensamiento numérico -- Pensamiento variacional -- Diseño de modelo matemático con aplicación de costos de producción -- Modelo matemático del consumo de gas en un artefacto afectado por su presión de trabajo -- Planeación de la producción agrícola: Caso plan óptimo de siembra que permita alcanzar la máxima rentabilidad del cultivo -- Estudio del Álgebra de Boole -- Diseño de un modelo de inventarios para una pequeña empresa de calzado de dotación -- Estudio de la Ley de Ohm mediante herramienta interactiva -- Pensamiento métrico-geométrico -- Pensamiento geométrico -- Pensamiento métrico -- Caso de optimización de recursos en el sector industrial de la confección -- Optimización de espacios para huertas urbanas -- Optimización de los costos del espacio de almacenamiento en microempresas y pequeñas empresas de acuerdo con las normas de seguridad vigentes -- Unidad de medida métrica para confección de ropa exterior femenina -- Optimización de recursos aplicando el proceso administrativo -- Pensamiento aleatorio -- Estadística Básica para Articulación con la Media -- Evaluación del impacto de la accidentalidad en la implementación del Sistema de Gestión de Seguridad y Salud en el Trabajo (sg-sst) por medio de indicadores -- Identificar los aspectos de la declaración de renta para una persona natural no obligada a llevar contabilidad -- Fortalecimiento de la estadística: caso de las unidades productivas del Centro de Biotecnología Agropecuaria -- Estadística dinámica -- Resultados preliminaresna[270 páginas

    Lo glocal y el turismo. Nuevos paradigmas de interpretación.

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    El estudio del turismo se realiza desde múltiples escalas y enfoques, este libro aborda muchos temas que es necesario discutir desde diversas perspectivas; es el caso de la reflexión sobre la propia disciplina y sus conceptos, así como los asuntos específicos referidos al impacto territorial, los tipos de turismo, las cuestiones ambientales, el tema de la pobreza, la competitividad, las políticas públicas, el papel de las universidades, las áreas naturales protegidas, la sustentabilidad, la cultura, el desarrollo, la seguridad, todos temas centrales documentados y expuestos con originalidad y dominio del asunto. Lo multiescalar es básico para la comprensión del sistema turístico, sistema formado de procesos globales, regionales y locales. El eje de discusión del libro es lo glocal, esa interacción entre lo nacional y local con lo global

    Compromising between European and US allergen immunotherapy schools: Discussions from GUIMIT, the Mexican immunotherapy guidelines

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    Background: Allergen immunotherapy (AIT) has a longstanding history and still remains the only disease-changing treatment for allergic rhinitis and asthma. Over the years 2 different schools have developed their strategies: the United States (US) and the European. Allergen extracts available in these regions are adapted to local practice. In other parts of the world, extracts from both regions and local ones are commercialized, as in Mexico. Here, local experts developed a national AIT guideline (GUIMIT 2019) searching for compromises between both schools. Methods: Using ADAPTE methodology for transculturizing guidelines and AGREE-II for evaluating guideline quality, GUIMIT selected 3 high-quality Main Reference Guidelines (MRGs): the European Academy of Allergy, Asthma and Immunology (EAACI) guideines, the S2k guideline of various German-speaking medical societies (2014), and the US Practice Parameters on Allergen Immunotherapy 2011. We formulated clinical questions and based responses on the fused evidence available in the MRGs, combined with local possibilities, patient's preference, and costs. We came across several issues on which the MRGs disagreed. These are presented here along with arguments of GUIMIT members to resolve them. GUIMIT (for a complete English version, see Supplementary data) concluded the following: Results: Related to the diagnosis of IgE-mediated respiratory allergy, apart from skin prick testing complementary tests (challenges, in vitro testing and molecular such as species-specific allergens) might be useful in selected cases to inform AIT composition. AIT is indicated in allergic rhinitis and suggested in allergic asthma (once controlled) and IgE-mediated atopic dermatitis. Concerning the correct subcutaneous AIT dose for compounding vials according to the US school: dosing tables and formula are given; up to 4 non-related allergens can be mixed, refraining from mixing high with low protease extracts. When using European extracts: the manufacturer's indications should be followed; in multi-allergic patients 2 simultaneous injections can be given (100% consensus); mixing is discouraged. In Mexico only allergoid tablets are available; based on doses used in all sublingual immunotherapy (SLIT) publications referenced in MRGs, GUIMIT suggests a probable effective dose related to subcutaneous immunotherapy (SCIT) might be: 50–200% of the monthly SCIT dose given daily, maximum mixing 4 allergens. Also, a table with practical suggestions on non-evidence-existing issues, developed with a simplified Delphi method, is added. Finally, dissemination and implementation of guidelines is briefly discussed, explaining how we used online tools for this in Mexico. Conclusions: Countries where European and American AIT extracts are available should adjust AIT according to which school is followed

    SELNET clinical practice guidelines for bone sarcoma

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    Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context

    Dendritic cell deficiencies persist seven months after SARS-CoV-2 infection

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    Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 infection induces an exacerbated inflammation driven by innate immunity components. Dendritic cells (DCs) play a key role in the defense against viral infections, for instance plasmacytoid DCs (pDCs), have the capacity to produce vast amounts of interferon-alpha (IFN-α). In COVID-19 there is a deficit in DC numbers and IFN-α production, which has been associated with disease severity. In this work, we described that in addition to the DC deficiency, several DC activation and homing markers were altered in acute COVID-19 patients, which were associated with multiple inflammatory markers. Remarkably, previously hospitalized and nonhospitalized patients remained with decreased numbers of CD1c+ myeloid DCs and pDCs seven months after SARS-CoV-2 infection. Moreover, the expression of DC markers such as CD86 and CD4 were only restored in previously nonhospitalized patients, while no restoration of integrin β7 and indoleamine 2,3-dyoxigenase (IDO) levels were observed. These findings contribute to a better understanding of the immunological sequelae of COVID-19
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