1,664 research outputs found

    A new landscape of host–protozoa interactions involving the extracellular vesicles world

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    This version is free to view and download for private research and study only. Not for re-distribution, re-sale or use in derivative works. © Cambridge University Press 2018Extracellular vesicles (EVs) are released by a wide number of cells including blood cells, immune system cells, tumour cells, adult and embryonic stem cells. EVs are a heterogeneous group of vesicles (~30–1000 nm) including microvesicles and exosomes. The physiological release of EVs represents a normal state of the cell, raising a metabolic equilibrium between catabolic and anabolic processes. Moreover, when the cells are submitted to stress with different inducers or in pathological situations (malignancies, chronic diseases, infectious diseases.), they respond with an intense and dynamic release of EVs. The EVs released from stimulated cells vs those that are released constitutively may themselves differ, both physically and in their cargo. EVs contain protein, lipids, nucleic acids and biomolecules that can alter cell phenotypes or modulate neighbouring cells. In this review, we have summarized findings involving EVs in certain protozoan diseases. We have commented on strategies to study the communicative roles of EVs during host–pathogen interaction and hypothesized on the use of EVs for diagnostic, preventative and therapeutic purposes in infectious diseases. This kind of communication could modulate the innate immune system and reformulate concepts in parasitism. Moreover, the information provided within EVs could produce alternatives in translational medicine.Peer reviewedFinal Accepted Versio

    Marketing Turistico : La Calidad en el Servicio Turistico de Aventura

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    El presente trabajo para optar al título de licenciadas en mercadotecnia. Tiene como tema principal marketing turístico, el cual tiene como subtema la calidad en el servicio turístico de aventura. El objetivo general de este estudio es conocer los elementos que forman parte de la calidad en el servicio turístico de aventura. La base teórica que sustenta esta investigación está fundamentada a partir de las normas y políticas de calidad, INTUR rige las empresas que brindan el servicio de turismo, de igual forma autores especialista en el tema de marketing turístico entre algunos tenemos; Philip Kotler y Gary Armstrong, William stanton, Cristopher lovelock, Amparo Sancho, entre otros. Así mismo aplicamos en este documento las normas APA sexta edición. Para la elaboración de este documento se aplicó la metodología de investigación documental, y se aplicó las herramientas de observación y recolección de información propias de la metodología empleada. El instrumento usado para la recolección de información fue la elaboración de una guía documental, fichas bibliográficas y fuentes de internet, que contienen textos e investigaciones de diferentes autores que han trabajado en la materia de la Calidad en servicios turísticos de aventura. Esta investigación de seminario de graduación está compuesta por: resumen, introducción, justificación, objetivos, desarrollo de tres capítulos, conclusión y bibliografía

    Influencia de las estrategias promocionales en el comportamiento del consumidor, en el Beneficio Sajonia S.A Matagalpa (conforme a su producto CAFÉ GALLO), de la ciudad de Matagalpa, Año 2016

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    En el presente trabajo investigativo se decidió realizar un estudio sobre las ´´Influencias de las estrategias promocionales en el comportamiento del consumidor en el Beneficio Sajonia S,A (conforme a su producto CAFÉ GALLO), de la ciudad de Matagalpa, en el año 2016´´ La presente investigación tuvo como propósito ´´analizar las influencias de las estrategias promocionales en el comportamiento del consumidor en el Beneficio Sajonia S,A (conforme a su producto CAFÉ GALLO), de la ciudad de Matagalpa´´. Para identificar las estrategias promocionales que utiliza la empresa, describir la comunicación integral de marketing utilizada por la empresa, y valorar la toma de decisión de compra del consumidor. Este trabajo es importante porque abarca las diferentes estrategias promocionales utilizadas por la empresa para influenciar al consumidor a la compra de un producto y valorar el comportamiento y decisión de compra del consumidor En este trabajo se describen las diferentes estrategias promocionales aplicadas por la entidad para ser partícipe dentro del mercado las cuales le permitirán una ventaja competitiva en el lanzamiento del producto. Así mismo se logró identificar los principales factores internos y externos que influyen en el proceso de toma de decisión de compra El presente trabajo tuvo como universo de estudio la población de municipio de Matagalpa, como población los clientes potenciales de café gallo, y por medio de una ecuación probabilística obtuvimos una muestra de 96 clientes del café. Finalmente se ha concluido que el beneficio Sajonia S.A, con respecto a la toma de decisión de compra del consumidor, estos no han sido influenciados por los componentes de Comunicación Integral de Marketing, como son la publicidad y las promociones de ventas ya que para ofertar el producto no realizaron suficiente publicidad y casi no realizan promociones de venta

    Complement C2 Receptor Inhibitor Trispanning Confers an Increased Ability to Resist Complement-Mediated Lysis in Trypanosoma cruzi

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    The ability to resist complement differs between theYand Colombiana Trypanosoma cruzi strains.Wefound that the Y strain of T. cruzi was more able to resist the classical and lectin pathways of complement activation than the Colombiana strain. The complement C2 receptor inhibitor trispanning gene (CRIT) is highly conserved in both strains. At the protein level, CRIT is expressed only in stationary-phase epimastigotes of the Y but not the Colombiana strain and is expressed in infectious metacyclic trypomastigotes of both strains. Y strain epimastigotes with an overexpressed CRIT gene (pTEX-CRIT) had higher survival in normalhumanserum (NHS). Overexpression of the Y strain CRIT gene in Colombiana epimastigote forms increased the parasite's resistance to lysis mediated by the classical and lectin pathways but not to lysis mediated by alternative pathways. CRIT involvement on the parasite surface was confirmed by showing that the lytic activity ofNHSagainst epimastigotes could be restored by adding excess C

    Routine HIV Testing in Adolescents and Young Adults Presenting to an Outpatient Clinic in Durban, South Africa

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    Objectives: Although youth (12–24 years) in Sub-Saharan Africa have a high HIV risk, many have poor access to HIV testing services and are unaware of their status. Our objective was to evaluate the proportion of adolescents (12–17 years) and young adults (18–24 years) who underwent HIV testing and the prevalence among those tested in an urban adult outpatient clinic with a routine HIV testing program in Durban, South Africa. Design: We conducted a retrospective cross-sectional analysis of adolescent and young adult outpatient records between February 2008 and December 2009. Methods: We determined the number of unique outpatient visitors, HIV tests, and positive rapid tests among those tested. Results: During the study period, 956 adolescents registered in the outpatient clinic, of which 527 (55%) were female. Among adolescents, 260/527 (49%, 95% CI 45–54%) females underwent HIV testing compared to 129/429 (30%, 95% CI 26–35%) males (p<0.01). The HIV prevalence among the 389 (41%, 95% CI 38–44%) adolescents who underwent testing was 16% (95% CI 13–20%) and did not vary by gender (p = 0.99). During this period, there were 2,351 young adult registrations, and of these 1,492 (63%) were female. The proportion consenting for HIV testing was similar among females 980/1,492 (66%, 95% CI 63–68%) and males 543/859 (63%, 95% CI 60–66%, p = 0.25). Among the 1,523 (65%, 95% CI 63–67%) young adults who underwent testing, the HIV prevalence was 22% (95% CI 19–24%) in females versus 14% in males (95% CI 11–17%, p<0.01). Conclusions: Although the HIV prevalence is high among youth participating in an adult outpatient clinic routine HIV program, the uptake of testing is low, especially among 12–17 year old males. There is an urgent need to offer targeted, age-appropriate routine HIV testing to youth presenting to outpatient clinics in epidemic settings

    T-cell derived acetylcholine aids host defenses during enteric bacterial infection with Citrobacter rodentium.

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    The regulation of mucosal immune function is critical to host protection from enteric pathogens but is incompletely understood. The nervous system and the neurotransmitter acetylcholine play an integral part in host defense against enteric bacterial pathogens. Here we report that acetylcholine producing-T-cells, as a non-neuronal source of ACh, were recruited to the colon during infection with the mouse pathogen Citrobacter rodentium. These ChAT+ T-cells did not exclusively belong to one Th subset and were able to produce IFNγ, IL-17A and IL-22. To interrogate the possible protective effect of acetylcholine released from these cells during enteric infection, T-cells were rendered deficient in their ability to produce acetylcholine through a conditional gene knockout approach. Significantly increased C. rodentium burden was observed in the colon from conditional KO (cKO) compared to WT mice at 10 days post-infection. This increased bacterial burden in cKO mice was associated with increased expression of the cytokines IL-1β, IL-6, and TNFα, but without significant changes in T-cell and ILC associated IL-17A, IL-22, and IFNγ, or epithelial expression of antimicrobial peptides, compared to WT mice. Despite the increased expression of pro-inflammatory cytokines during C. rodentium infection, inducible nitric oxide synthase (Nos2) expression was significantly reduced in intestinal epithelial cells of ChAT T-cell cKO mice 10 days post-infection. Additionally, a cholinergic agonist enhanced IFNγ-induced Nos2 expression in intestinal epithelial cell in vitro. These findings demonstrated that acetylcholine, produced by specialized T-cells that are recruited during C. rodentium infection, are a key mediator in host-microbe interactions and mucosal defenses

    Insulin-like growth factor I gene promoter polymorphism, collagen type II alpha1 (COL2A1) gene, and the prevalence of radiographic osteoarthritis: the Rotterdam Study

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    OBJECTIVE: To examine the role of an IGF-I gene promoter polymorphism in the prevalence of radiographic osteoarthritis (ROA), and study its interaction with the COL2A1 gene. METHODS: Individuals genotyped for IGF-I (n = 1546) and COL2A1 gene polymorphisms (n = 808) were selected from a random sample (n = 1583) derived from the Rotterdam study. The presence of ROA was defined as a Kellgren score of 2 or more in at least one of four joints (knee, hip, hand, and spine). Genotype specific odds ratios (OR) were adjusted for age, sex, body mass index, and bone mineral density using logistic regression. Interaction with the COL2A1 genotype was tested. RESULTS: Overall, no association was found between the IGF-I polymorphism and ROA. In subjects aged 65 years or younger (n = 971), the prevalence of ROA increased with the absence of the 192 base pair (bp) allele (p for trend = 0.03). Compared with homozygotes for the 192 bp allele, the prevalence of ROA was 1.4 times higher in heterozygotes (95% confidence interval, 1.0 to 1.8) and 1.9 times higher in non-carriers (1.1 to 3.3). There was evidence of interaction between the IGF-I and COL2A1 genes. Individuals with the risk genotype of both genes had an increased prevalence of ROA (OR 3.4 (1.1 to 10.7)). No effect was observed in subjects older than 65 years. CONCLUSIONS: SUBJECTS: with genetically determined low IGF-I expression (non-carriers of the 192 bp allele) may be at increased risk of ROA before the age of 65 years. Furthermore, an interaction between the IGF-I and COL2A1 genes is suggested

    Trigeminovascular calcitonin gene-related peptide function in Cacna1a R192Q-mutated knock-in mice

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    Familial hemiplegic migraine type 1 (FHM1) is a rare migraine subtype. Whereas transgenic knock-in mice with the human pathogenic FHM1 R192Q missense mutation in the Cacna1a gene reveal overall neuronal hyperexcitability, the effects on the trigeminovascular system and calcitonin gene-related peptide (CGRP) receptor are largely unknown. This gains relevance as blockade of CGRP and its receptor are therapeutic targets under development. Hence, we set out to test these effects in FHM1 mice. We characterized the trigeminovascular system of wild-type and FHM1 mice through: (i) in vivo capsaicin- and CGRP-induced dural vasodilation in a closed-cranial window; (ii) ex vivo KCl-induced CGRP release from isolated dura mater, trigeminal ganglion and trigeminal nucleus caudalis; and (iii) peripheral vascular function in vitro. In mutant mice, dural vasodilatory responses were significantly decreased compared to controls. The ex vivo release of CGRP was not different in the components of the trigeminovascular system between genotypes; however, sumatriptan diminished the release in the trigeminal ganglion, trigeminal nucleus caudalis and dura mater but only in wild-type mice. Peripheral vascular function was similar between genotypes. These dat

    Best Practice for the Treatment of Intertrigo

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    This literature review aims at exploring different treatment options for individuals diagnosed with intertrigo. Ten articles were reviewed between August and November 2018 with the purpose of helping Village Northwest Unlimited develop a therapeutic guideline for patients at risk or that are currently afflicted with the skin condition. After reviewing the literature, the researchers have concluded that there are multiple options for treatment rather than a single best treatment option for intertrigo. However, throughout this literature review, the researchers have provided many research articles that share possible treatment options for patients with intertrigo

    Aislamiento y caracterización fenotípica y molecular de cepas nativas de Bacillus thuringiensis aisladas de ecoregiones de la costa del Perú con actividad larvicida para Aedes (Stegomyia) aegypti (L)

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    Aedes aegypti es un vector de enfermedades de importancia en salud pública que es controlado con insecticidas químicos, sin embargo la naturaleza de estos insecticidas generan daños al ambiente y al hombre, además de generar resistencia entre las poblaciones de mosquitos. El objetivo de la presente investigación fue aislar y caracterizar cepas nativas de Bacillus thuringiensis con actividad larvicida frente a Aedes aegypti que puedan ser utilizadas como controladores biológicos de éste mosquito vector, y ser una alternativa más ecológica frente al uso de los insecticidas químicos. Las cepas fueron aisladas de tres ecorregiones costeras del Perú, las que fueron caracterizadas a través de pruebas bioquímicas diferenciales, observación de cristales parasporales y caracterizadas molecularmente a través de la detección de genes cry4Aa, cry11Aa y cyt1Aa. La actividad larvicida de las cepas nativas fue determinada siguiendo la metodología descrita por la OMS (2005), y utilizando la cepa B. thuringiensis HD500 como patrón. De las ecorregiones de Piura, Chiclayo y Lima se aislaron 9 cepas nativas de Bacillus thuringiensis, de las cuales 3 mostraron alta toxicidad para larvas del tercer estadío de Aedes aegypti. Estas cepas mostraron cristales parasporales circulares, pruebas bioquímicas características de Bacillus thuringiensis y la posesión genes cry11Aa y cyt1Aa para dos de las cepas nativas y la presencia de todos los genes evaluados para una cepa nativa.Tesi
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