oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 1 )

2017 ( 5 )

2016 ( 1 )

2015 ( 46 )

Custom range...

Search Results: 1 - 10 of 2012 matches for " Silvio Urcuqui Inchima "
All listed articles are free for downloading (OA Articles)
Page 1 /2012
Display every page Item
Propagation of kinetic uncertainties through a canonical topology of the TLR4 signaling network in different regions of biochemical reaction space
Jayson Gutiérrez, Georges St Laurent, Silvio Urcuqui-Inchima
Theoretical Biology and Medical Modelling , 2010, DOI: 10.1186/1742-4682-7-7
Abstract: In this study, efforts were focused in the construction of a relatively well informed, deterministic, non-linear dynamic model, accounting for reaction mechanisms grounded on standard mass action and Hill saturation kinetics, of the canonical reaction topology underlying Toll-like receptor 4 (TLR4)-mediated signaling events. This signaling mechanism has been shown to be deployed in macrophages during a relatively short time window in response to lypopolysaccharyde (LPS) stimulation, which leads to a rapidly mounted innate immune response. An extensive computational exploration of the biochemical reaction space inhabited by this signal transduction network was performed via local and global perturbation strategies. Importantly, a broad spectrum of biologically plausible dynamical regimes accessible to the network in widely scattered regions of parameter space was reconstructed computationally. Additionally, experimentally reported transcriptional readouts of target pro-inflammatory genes, which are actively modulated by the network in response to LPS stimulation, were also simulated. This was done with the main goal of carrying out an unbiased statistical assessment of the intrinsic robustness properties of this canonical reaction topology.Our simulation results provide convincing numerical evidence supporting the idea that a canonical reaction mechanism of the TLR4 signaling network is capable of performing information processing in a robust manner, a functional property that is independent of the signaling task required to be executed. Nevertheless, it was found that the robust performance of the network is not solely determined by its design principle (topology), but this may be heavily dependent on the network's current position in biochemical reaction space. Ultimately, our results enabled us the identification of key rate limiting steps which most effectively control the performance of the system under diverse dynamical regimes.Overall, our in silico study sugg
Activación y regulación del inflamasoma NLRP3 en las enfermedades infecciosas
Hernández López,Juan Carlos; Urcuqui Inchima,Silvio;
Iatreia , 2012,
Abstract: inflammation is an immune response to infectious agents and to signals that arise from host molecules in stress situations or after tissue damage. many innate immune receptors take part in the inflammatory response and induce transcriptional activation leading to the production of a host of cytokines, chemokines and other inflammatory mediators. the il-1β cytokines are exceptional in that they not only require transcriptional activation but also a proteolytic processing into biologically active cytokines. this activation step is mediated by caspase-1, which in turn is controlled by cytosolic multimolecular complexes named inflammasomes. the nlrp3 inflammasome responds to aggregated or crystalline material, as well as to microbes or pore-forming toxins, but activation mechanisms are not fully understood. the importance of this innate signaling complex is highlighted by the existence of several mechanisms that regulate nlrp3 activation at different levels. in this article we review such mechanisms.
Viral recognition by the innate immune system: the role of pattern recognition receptors
Torres Pedraza,Silvia; Betancur,Juan Guillermo; Urcuqui-Inchima,Silvio;
Colombia Médica , 2010,
Abstract: pattern recognition receptors are the main sensors of the innate immune response. their function is to recognize pathogen-associated molecular patterns, which are molecules essential for the survival of microbial pathogens, but are not produced by the host. the recognition of pathogen-associated molecular patterns by pattern recognition receptors leads to the expression of cytokines, chemokines, and co-stimulatory molecules that eliminate pathogens, such as viruses, for the activation of antigen presenting cells and for the activation of specific adaptive immunity. among the most thoroughly studied pattern recognition receptors implicated in viral infections, there are the toll-like receptors (tlrs) and the rna helicase-type retinoic acid-inducible gene-1 receptors [or rig-like receptors (rlrs)]. moreover, other proteins such as pkr, 2?-5? oas, and adar also act as effector proteins in antiviral responses. the identification and characterization of pattern recognition receptors have contributed to our knowledge of the role of innate immunity in viral infections and has led us to better understand host-pathogen interactions. the most recent findings concerning the role of tlrs and rlrs in viral infections, the molecular mechanisms of viral ligand recognition through pattern recognition receptors, and the activation of their signaling pathways are discussed in this review.
Activation and Regulation of Inflammasome NLRP3 during Infectious Diseases = Activación y regulación del inflamasoma NLRP3 en las enfermedades infecciosas
Hernández López, Juan Carlos,Urcuqui Inchima, Silvio
Iatreia , 2012,
Abstract: Inflammation is an immune response to infectious agents and to signals that arise from host molecules in stress situations or after tissue damage. Many innate immune receptors take part in the inflammatory response and induce transcriptional responses leading to the production of a host of cytokines, chemokines and other inflammatory mediators. The IL-1β cytokines are exceptional in that they not only require transcriptional induction but also proteolytic processing into biologically active cytokines. This proteolytic activation step is mediated by caspase-1, which itself is controlled by cytosolic multi-molecular complexes that are termed inflammasomes. The NLRP3 inflammasome responds to aggregated or crystalline material, microbes or pore-forming toxins and the activation mechanisms are not fully understood. The importance of this innate signaling complex is highlighted by the existence of several mechanisms that regulate NLRP3 activation at different levels.
El desafío de las enfermedades priónicas, una emergencia en humanos y bovinos
Albeiro López Herrera,Anne Lise Haenni,Silvio Urcuqui Inchima
Veterinaria México , 2002,
Abstract: La encefalopatía espongiforme bovina (EEB), más comúnmente conocida como enfermedad de las vacas locas , es un malestar transmisible que en forma inesperada y desastrosa ha provocado una crisis severa en la industria cárnica en Europa. La inquietud que propicia la EEB es consecuencia de que la enfermedad es transmisible al hombre y al poco conocimiento que se tiene sobre el mecanismo de transmisión y la patogénesis. Con la presente revisión se pretende presentar una visión general sobre las características de la enfermedad en el bovino y en el humano, así como los avances científicos en este campo, incluyendo aspectos moleculares, celulares y clínicos.
Viral recognition by the innate immune system: the role of pattern recognition receptors
Silvia Torres Pedraza,Juan Guillermo Betancur,Silvio Urcuqui-Inchima
Colombia Médica , 2010,
Abstract: Pattern recognition receptors are the main sensors of the innate immune response. Their function is to recognize pathogen-associated molecular patterns, which are molecules essential for the survival of microbial pathogens, but are not produced by the host. The recognition of pathogen-associated molecular patterns by pattern recognition receptors leads to the expression of cytokines, chemokines, and co-stimulatory molecules that eliminate pathogens, such as viruses, for the activation of antigen presenting cells and for the activation of specific adaptive immunity. Among the most thoroughly studied pattern recognition receptors implicated in viral infections, there are the toll-like receptors (TLRs) and the RNA helicase-type retinoic acid-inducible gene-1 receptors [or RIG-like receptors (RLRs)]. Moreover, other proteins such as PKR, 2’-5’ OAS, and ADAR also act as effector proteins in antiviral responses. The identification and characterization of pattern recognition receptors have contributed to our knowledge of the role of innate immunity in viral infections and has led us to better understand host-pathogen interactions. The most recent findings concerning the role of TLRs and RLRs in viral infections, the molecular mechanisms of viral ligand recognition through pattern recognition receptors, and the activation of their signaling pathways are discussed in this review.
Papel de los receptores tipo toll en las infecciones virales: el VIH-1 como modelo
Hernández,Juan Carlos; Montoya,Carlos Julio; Urcuqui-Inchima,Silvio;
Biomédica , 2007,
Abstract: the toll-like receptors are an essential component of the innate and adaptive immune response. they are responsible for the recognition of different pathogens agents and trigger responses directed at eliminating the pathogens as well as the development of immunological long-term memory. during viral infections, several different toll-like receptors are activated. these generally induce a protective immune response, but at the same time, can also be part of the pathogenic mechanisms of the viral infection. one of the viral infections in which toll-like receptors participate is the hiv-1 infection. here, several receptors are activated to develop antiviral responses mediated by interferon type i; however virus replication and spreading dissemination are also favoured by signals derived from stimulation of the toll-like receptors. individuals co-infected with opportunistic microorganisms are particularly affected, promoting the progression of hiv-1 infection. an integral understanding of the behavior of toll-like receptors during viral infections will allow the design of prophylactic and/or therapeutic strategies, based on the modulation of the expression and function of these receptors. agonists of these receptors can be used effectively to control these viral infections.
Evidencia serológica de la infección por herpesvirus equino tipos 1 y 4 en dos regiones de Colombia Provas serológicas de infec o por equine herpesvirus 1 e 4, em duas regi es da Col mbia Serologic evidence of equine herpesvirus 1 and 4 infection in two regions of Colombia
Julián Ruíz Sáenz,Yenny Góez,Silvio Urcuqui Inchima,Agustín Góngora
Revista Colombiana de Ciencias Pecuarias , 2008,
Abstract: Los herpesvirus equinos tipos 1 y 4 (HVE-1 y HVE-4) son agentes de distribución mundial y causa de graves pérdidas económicas. La infección primaria por ambos virus se produce en el tracto respiratorio, progresa a través de la mucosa y puede alcanzar otros sistemas orgánicos ocasionando abortos en el último tercio de gestación, muerte perinatal y síndromes neurológicos poco específicos. El HVE-1 está asociado principalmente con abortos, mientras que el HVE-4 se asocia con enfermedad respiratoria. Los animales afectados se recuperan sin tratamiento, pero permanecen infectados toda la vida. En 2001 se reportó en Colombia un aislamiento de HVE, pero hasta la fecha no se conoce ningún estudio que confirme y determine el tipo de herpesvirus aislado. El objetivo del presente trabajo fue realizar un estudio serológico para determinar la presencia de los HVE-1 y HVE-4 en equinos clínicamente sanos, no vacunados contra HVE. Para lograr nuestro objetivo se tomaron 139 muestras de suero de equinos de dos regiones de Colombia (Antioquia y Meta), a partir de las cuales se realizó una prueba de ELISA indirecta, para detectar la presencia de anticuerpos dirigidos contra la glicoproteína G del HVE-1 y HVE-4. Se encontró una seropositividad para HVE-4 del 98.7 y 96.6% en Antioquia y Meta respectivamente; para HVE-1, la seropositividad fue del 18.8% en el departamento de Antioquia y 33.3% en departamento del Meta. Este es el primer estudio que reporta seropositividad en equinos clínicamente sanos no vacunados en Colombia, lo cual sugiere la presencia del virus y su establecimiento en la población equina de las regiones evaluadas, y posiblemente de otras zonas de Colombia. O herpesvirus eqüino tipo-1 e -4 (HVE-1 e HVE-4) s o os agentes de distribui o mundial e causam graves prejuízos econ micos. A infec o primária por ambos os vírus ocorre no trato respiratório, progredindo através da mucosa e podem atingir outros sistemas organicos causando abortos no último ter o da gesta o, morte perinatal e n o-específica síndromes neurológicas. O HVE-1 é principalmente associado a abortos, enquanto o HVE-4 está associado a doen as respiratórias. Os animais afectados recuperar sem tratamento, mas permanecem infectados vida. Em 2001, foi relatada na Col mbia isolamento de HVE, mas até agora n o teve conhecimento de qualquer estudo para confirmar e identificar o tipo de herpesvírus isolados. O objetivo deste estudo foi o de realizar um levantamento sorológico para determinar a presen a de HVE-1 e HVE-4 em cavalos clinicamente saudável, n o vacinadas contra o HVE. Para alcan ar nosso o
Evaluación de la expresión y función de PRR en neutrófilos, estimulados con VIH-1 in vitro
Diana M Giraldo-Giraldo,Juan C Hernández,Silvio Urcuqui-Inchima
Actualidades Biológicas , 2012,
Abstract:
Importancia de la proteína Rev del virus de la inmunodeficiencia humana tipo 1 en la inhibición de la replicación en células murinas
Sandra Marques,Jean-luc Veyrune,Ram Shukla,Silvio Urcuqui Inchima
Iatreia , 2001,
Abstract: Entre los obstáculos que existen para entender la infección y la respuesta inmune por el HIV-1 está la ausencia de modelos animales que permitan estudiar la patogénesis del SIDA. Modelos murinos han sido desarrollados, pero carecen de replicación productiva a largo término debido a que la glicoproteína de envoltura del HIV-1 no se une al receptor CD4 ni al correceptor CCR5 murino, o porque la transcripción directa del promotor es ineficiente debido a una actividad atenuada de Tat (1), que es rescatada por la ciclina T1 humana. La coexpresión de CD4, CCR5 humanas en cultivo de células murinas permite la entrada del virus sin viremia detectable. En animales transgénicos que expresan la ciclina T1, se observa un bloqueo postranscripcional que afecta la replicación. La proteína Rev es fundamental en el ciclo replicativo del HIV-1 (2); el bloqueo de su actividad explicaría la ausencia de replicación del virus en células murinas. El objetivo de este trabajo fue evaluar y caracterizar el dominio de Rev implicado en el bloqueo de la exportación en células murinas.
Page 1 /2012
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.