Browsing by Autor "Guillermo Comach"

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Antiviral resistance in influenza viruses circulating in Central and South America based on the detection of established genetic markers
(Wiley, 2009) Josefina García; Merly Sovero; Alberto Torres; Jorge Gómez; Richard W. Douce; Melvin Barrantes; Félix Sánchez; Mirna Jimenez; Guillermo Comach; Ivette De Rivera
These findings suggest a limited effectiveness of influenza inhibitors due to the detection of resistance among A/H1 and A/H3 viruses.
Cambios dinámicos de citoquinas proinflamatorias, moléculas de adhesión y marcadores de activación linfocítica como indicadores tempranos de severidad en pacientes con Dengue
(Universidad Internacional de La Rioja, 2014) Silvana Vielma; María Odreman Macchioli; Saberio Pérez; Noraida Mosqueda; Guillermo Comach; Eduardo Gallardo Téllez; José Mendoza
Varios mecanismos inmuno-patogénicos se han propuesto para explicar el incremento masivo de la permeabilidad vascularobservada en las formas severas de la infección por el Virus del Dengue (DENV). El objetivo del estudio fue determinar loscambios cinéticos de mediadores inflamatorios (IL-8, TNF-α), marcadores soluble de activación linfocítica temprana (sIL-2R,sTNF-Rp75) y fracciones solubles de moléculas de adhesión celular (sICAM-1, sVCAM-1) como marcadores tempranos deseveridad en pacientes con dengue. Veinte pacientes clasificados como Dengue (Dengue±Signos de Alarma,D±WS) y treintapacientes con Dengue Severo (DS) fueron incluidos en el estudio. Suero de individuos aparentemente saludables fueronincluidos como controles. En comparación con los individuos controles, los casos con Dengue mostraron niveles de IL-8 yTNF con diferencias no significativas en la fase febril o crítica de la enfermedad; sin embargo, un incremento significativo desICAM-1 y sVCAM-1 ocurrió en ambas fases, mientras que los niveles de sIL2R y sTNF-p75 se elevaron significativamentesolo en la fase crítica de la enfermedad. En comparación con los casos con dengue y controles, los pacientes con DS mostraron diferencias significativas en los niveles de IL-8 y TNF-α durante la fase crítica y un incremento significativo demoléculas de adhesión en ambas fases, pero los niveles más elevados de sVCAM-1 y sIL-2R fueron observados en la fasefebril. En conclusión, sIL-2R y sVCAM-1, como marcadores tempranos de activación linfocítica y endotelial, servirían comoindicadores de severidad en la fase aguda de la infección por el virus del dengue.Dinamic changes of pro-inflammatory cytokines, adhesion molecules and lymphocytesactivation markers as early indicators of diseases severity in patients with DengueAbstractSeveral immunopathogenic mechanisms have been proposed to explain the massive increase of vascular permeabilityobserved in the severe forms of infection by Dengue Virus (DENV). Our aim was to determine the kinetic changes ofinflammatory mediators (IL-8, TNF- α), soluble early lymphocyte activation markers (sIL-2R, sTNF-Rp75) and solublefractions of cell adhesion molecules (sICAM-1 and sVCAM-1) as indicators for early recognition of disease severity inpatients with laboratory-confirmed dengue. Twenty patients classified as Dengue±Warning Signs (D±WS) and thirty patientswith Severe Dengue (SD) were included in the study. Serums of apparently healthy individuals were included as controls.Compared with normal subjects, D±WS cases did not show significant differences in the levels of IL-8 or TNF-α during theacute nor in the critical stages of the disease; however, in D±WS cases levels of sICAM-1 and sVCAM-1 were higher thancontrols during both phases; in contrast, significant increase of sTNF-p75 and sIL2R levels were observed during the criticalphase of the disease. Compared with both dengue patients and controls, patients with SD showed significant rise in thelevels of IL-8 and TNF-α during the critical phase of the disease and a significant increase in adhesion molecules weredetected in both phases, but the highest levels of sVCAM-1 and sIL-2R were observed only during the acute stage of thedisease. In conclusion, sIL-2R and sVCAM-1, as early markers of lymphocyte and endothelial activation, would serves asindicators of severity during the acute phase of dengue infection.
Circulating Strains of Human Respiratory Syncytial Virus in Central and South America
(Public Library of Science, 2011) Merly Sovero; Josefina García; Tadeusz J. Kochel; V. Alberto Laguna-Torres; Jorge Gómez; Wilson Chicaiza; Melvin Barrantes; Félix Sánchez; Mirna Jimenez; Guillermo Comach
Human respiratory syncytial virus (HRSV) is a major cause of viral lower respiratory tract infections among infants and young children. HRSV strains vary genetically and antigenically and have been classified into two broad subgroups, A and B (HRSV-A and HRSV-B, respectively). To date, little is known about the circulating strains of HRSV in Latin America. We have evaluated the genetic diversity of 96 HRSV strains by sequencing a variable region of the G protein gene of isolates collected from 2007 to 2009 in Central and South America. Our results show the presence of the two antigenic subgroups of HRSV during this period with the majority belonging to the genotype HRSV-A2.
Molecular characterization of adenovirus circulating in Central and South America during the 2006–2008 period
(Wiley, 2009) Josefina García; Merly Sovero; V. Alberto Laguna-Torres; Jorge Gómez; Wilson Chicaiza; Melvin Barrantes; Félix Sánchez; Mirna Jimenez; Guillermo Comach; Ivette Lorenzana
Our results indicate that 161(76%) adenoviruses belong to subgroup C, 45 (21%) to subgroup B and 7 (3%) to subtype E4.
Molecular epidemiology of dengue virus type 3 in Northern South America: 2000–2005
(Elsevier BV, 2008) Tadeusz J. Kochel; Patricia Aguilar; Vidal Felices; Guillermo Comach; Cristhopher D. Cruz; Aracely Alava; Jorge Vargas; James G. Olson; Patrick J. Blair