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Search Results: 1 - 10 of 7044 matches for " Leticia; Monsalve-Castillo "
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Mecanismos de evasión inmunitaria del Virus de Hepatitis C. Revisión. Immune evasion mechanisms of Hepatitis C virus. Review.
Leticia Porto-Espinoza,César Cuadra-Sánchez,Reyna Moronta,Francisca Monsalve-Castillo
Investigación Clínica , 2006,
Abstract: El virus de Hepatitis C (VHC) constituye un problema de salud pública mundial. La mayoría de las infecciones se tornan crónicas, ocasionando con frecuencia cirrosis hepática y carcinoma hepatocelular a largo plazo, precisándose no pocas veces de transplantes hepáticos para prolongar la vida del individuo. El mantenimiento de una infección crónica implica la evasión al sistema inmunitario del hospedero. Los mecanismos virales involucrados en dicha evasión están siendo estudiados arduamente con el fin de desarrollar nuevas terapias preventivas y curativas efectivas contra el virus. Una característica importante, la extrema variabilidad genética del virus, se cree que contribuya al escape inmunitario al cambiar continuamente los epítopos expuestos a la detección; sin embargo, algunos trabajos sugieren que no es necesaria para el establecimiento de la cronicidad de la infección. Por otra parte, el estudio comparativo de la respuesta inmunitaria de los pacientes que se recuperan espontáneamente con la de aquellos infectados de manera crónica, se ala que algunas proteínas virales podrían inducir cierta inmunosupresión indispensable para la persistencia en el hospedero. Concretamente, se cree que las proteínas NS5A, E2 y core modulan ciertos mecanismos de las respuestas innata y específica. El análisis de los hallazgos relacionados con el tópico permite sugerir la existencia de una sinergia entre la variación genética y la inmunosupresión para evadir de manera continua la detección y destrucción por parte del sistema de defensas del individuo. Hepatitis Virus C (HCV) is a major worldwide health care problem. HCV infection usually tends to become chronic and can generate long term hepatic cirrhosis and hepatocellular carcinoma. These affections frequently require a liver transplant to prolong the patients life. Maintenance of the chronic infection implies evasion of the host immune responses. Viral mechanisms involved in this evasion are being profusely studied in order to develop new and effective therapies and vaccines against HCV. An important HCV characteristic, its high genetic variability, has been proposed to contribute to immune evasion by means of antigenic change and variation. On the other hand, some studies suggest that genetic variability is not necessary to establish a chronic infection. Other studies related to immune responses in patients with spontaneous virus clearance and patients with chronic infection show a possible immunosuppression caused by some viral proteins, that may be essential to persist in the host. Specifically, it is believed t
Mecanismos de evasión inmunitaria del Virus de Hepatitis C. Revisión.
Porto-Espinoza,Leticia; Cuadra-Sánchez,César; Moronta,Reyna; Monsalve-Castillo,Francisca; Callejas-Valero,Diana;
Investigación Clínica , 2006,
Abstract: hepatitis virus c (hcv) is a major worldwide health care problem. hcv infection usually tends to become chronic and can generate long term hepatic cirrhosis and hepatocellular carcinoma. these affections frequently require a liver transplant to prolong the patients life. maintenance of the chronic infection implies evasion of the host immune responses. viral mechanisms involved in this evasion are being profusely studied in order to develop new and effective therapies and vaccines against hcv. an important hcv characteristic, its high genetic variability, has been proposed to contribute to immune evasion by means of antigenic change and variation. on the other hand, some studies suggest that genetic variability is not necessary to establish a chronic infection. other studies related to immune responses in patients with spontaneous virus clearance and patients with chronic infection show a possible immunosuppression caused by some viral proteins, that may be essential to persist in the host. specifically, it is believed that viral proteins ns5a, e2 and core modulate some innate and specific immune mechanisms. the analysis of all data related to this topic suggests the existence of synergistic cooperation between viral variation and immunosuppression to overcome the immune defenses of the host.
Incidencia de la infección por el virus de la hepatitis A diagnosticadas en la ciudad de Maracaibo, estado Zulia, Venezuela
Costa-León,Luciana; Porto-Espinoza,Leticia; Monsalve-Castillo,Francisca; Callejas-Valero,Diana; Estévez,Jesús; Castellanos Sánchez,María Elena;
Kasmera , 2010,
Abstract: hepatitis a virus (hav) infection continues to be a public health problem in developing countries. the aim of this study was to determine incidence of the hepatitis a virus infection in a population from maracaibo, venezuela. from january, 2004 until december, 2007, this study was carried out on 1056 individuals, whose ages were between 1-60 years (average ± ds: 27.48 ± 5.24 years), coming from the maracaibo and san francisco municipalities, venezuela. the igm antibody against hav was determined by the elisa technique. the overall incidence was 26.6%. the north, south, east and west areas of the maracaibo municipality and the san francisco municipality in the city of maracaibo showed incidences of 73 (35.1%), 76 (28%), 66 (24.3%), 35 (20.3%) and 31(23.3%), respectively. the highest incidences were observed in females under 20 years (47.3%) and males under 10 years (53.7%). the most frequent clinical sign was jaundice in 95.7% of patients. deficient sanitary conditions and hygiene habits seemed to be the main risk factors in spreading hav infection.
Diagnóstico diferencial de virus hepatótropos y no hepatótropos en pacientes atendidos en el Laboratorio Regional de Referencia Virológica: Maracaibo-Venezuela, a?o 2007
Costa-León,Luciana; Monsalve-Castillo,Francisca; Callejas-Valero,Diana; Porto-Espinoza,Leticia; Estévez,Jesús; Castellanos,María Elena; Mindiola,Raimy;
Kasmera , 2010,
Abstract: viral hepatitis is a public health problem worldwide, caused by different etiologic agents, such as hepatitis a, b, c, d, e, f or g. however, cases have been reported related to liver disease caused by hepatotropic viruses, such as cytomegalovirus (cmv) and epstein barr virus (ebv). the aim of this study was to establish the differential diagnosis of hepatotropic and non-hepatotropic viruses in patients with symptoms and signs suggestive of liver infection in the city of maracaibo, venezuela, 2007. 268 blood samples were collected from patients at different health centers in the city of maracaibo, who recurred to the regional viral reference laboratory. the presence of igm antibodies to hepatitis a virus (hav), b (hbv), c (hcv), cmv and ebv was detected by elisa. the results indicate a high incidence of hav 118/268 (44.03%), followed by hbv 5/268 (1.86%) and the absence of hcv. for non-hepatotropic viruses, 4.48% (12/268) were positive for ebv and 9.7% (26/268) for cmv. for the above-mentioned viruses, 39.92% (107/268) are considered negative. this study suggests that cmv and ebv viruses are often involved with liver damage and should be considered as possible etiologic agents for any case of hepatitis.
Low prevalence of hepatitis C virus infection in Amerindians from Western Venezuela
Monsalve-Castillo, Francisca;Chacín-Bonilla, Leonor;Atencio, Ricardo J;Espinoza, Leticia Porto;Costa-León, Luciana;Echevarría, José M;
Memórias do Instituto Oswaldo Cruz , 2007, DOI: 10.1590/S0074-02762007000100018
Abstract: previous studies have not found hepatitis c virus (hcv) infection in amerindians from western venezuela. a survey of 254 bari and yukpa natives aged 10-60 years (mean ± sd age = 35 ± 5.4 years) from four communities, two bari and two yukpa, in this area were studied to assess the prevalence of antibodies to hcv (anti-hcv) and hcv rna among these indigenous populations. serum samples were examined initially for anti-hcv by a four generation enzyme-linked immunosorbent assay (elisa). reactive samples were then tested using a third generation recombinant immunoblot assay (riba-3). viral rna was investigated in all immunoblot-reactive samples by a nested polymerase chain reaction (pcr) method. six (2.3%) of 254 natives were positive by elisa, one (2.2%) of these reactive samples were positive by riba, and four (1.5%) were indeterminate. only two (0.8%) were positive by pcr, corresponding to 1 (2.1%) of 47 inhabitants of a yukpa community and to 1 (2.2%) of 45 subjects of a bari community. iatrogenic is thought to play a role in acquisition of the infection. the findings indicate a hcv focus of low endemicity and are compatible with a low degree of exposures of the natives to the virus. studies are necessary to assess the risk factors for infection in these amerindians.
Hepatitis C virus infection in hemodialysis patients in Maracaibo, Venezuela
Monsalve-Castillo, Francisca;Gómez-Gamboa, Liliana;Chacín-Bonilla, Leonor;Porto-Espinoza, Leticia;Costa-León, Luciana;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2012, DOI: 10.1590/S0036-46652012000100010
Abstract: over a two year period, the incidence of hepatitis c virus (hcv) infection was evaluated in 29 hemodialysis patients, aged between 15 and 75 years (mean ± sd: 45 ± 39.5 years), from the university hospital hemodyalisis unit, maracaibo, zulia state, venezuela. anti-hcv antibodies were determined using a fourth generation elisa (innotest hcv ab iv) kit and positive blood samples were tested using a recombinant assay kit (inno-lia hcv ab iii), both kits from innogenetics n.v., belgium. the findings indicate a lack of hcv seroconversion in the hemodialysis patients over the study period, confirmed by the recombinant assay. risk factors for hcv infection were 0.3270 (95% confidence interval: 0.01323-8.080) in patients undergoing hemodialysis. the findings suggest a lack of significant sources for hcv infection due to the preventive measures to avoid its transmission in the hemodialysis unit.
Baja prevalencia de la infección por el virus de la hepatitis C en una población de reclusos, Maracaibo, Venezuela
Monsalve-Castillo,Francisca; Chacín-Bonilla,Leonor; Atencio,Ricardo José; Porto,Leticia Denys; Costa-León,Luciana Ana; Estévez,Jesús Enrique; Callejas-Valero,Diana Estela;
Biomédica , 2009,
Abstract: introduction. the high risk behaviors observed in prison centers have favored the transmission of hepatitis c virus infection. the main risk factor to acquire hepatitis c virus infection seems to be the use of intravenous drugs. in venezuela, the prevalence of the infection in these centers is unknown since studies of the hepatitis c virus there are lacking. objective. the aim of this study was to determine the prevalence of hepatitis c virus and the risk factors involved in the transmission in prisoner populations. material and methods. a sample of 200 prisoners was studied from sabaneta jail, maracaibo, venezuela. the ages were between 18-69 years (average ± ds: 31.6±9.9 years). serum samples were tested by a fourth generation enzyme-linked immunosorbent assay elisa and a confirmatory assay inno-lia. both kits were from innogenetic laboratories n.v. (belgium). viral rna was tested by the reverse transcription polymerase chain reaction technique (rt-pcr). results. the elisa assay determined a hepatitis c virus prevalence of 5.0% (10/200); 3/200 (1.5%) individuals were positive by both inno-lia and rt-pcr tests. conclusions. the observed prevalence of hepatitis c virus antibodies in this population was very low, suggesting a low circulation of the virus in this environment and a low level of associated risk behaviors.
Carga viral en pacientes pediátricos VIH positivos con terapia antirretroviral
Porto-Espinoza,Leticia; Moronta,Reyna; Cuadra-Sánchez,César; Callejas-Valero,Diana; Costa-León,Luciana; Monsalve-Castillo,Francisca; Bernardoni,Cecilia; Estévez,Jesús;
Revista médica de Chile , 2008, DOI: 10.4067/S0034-98872008000800009
Abstract: background: viral load in pediatric patients with hiv infections can help to make therapeutic decisions to modify the evolution of the disease. aim: to evaluate viral load in positive hiv children with antiretroviral treatment. material and methods: viral load was measured every six months during three years in fifty pediatric patients chosen randomly in aged 1 to 12 years, using the test monitor hiv-1 amplicor, versión 1.5. results: during the three years follow up, there was an increase in cd4 and cd8 lymphocyte count and decrease in the viral load. however, there was no significant relationship between lymphocyte subpopulation counts and viral loads. conclusions: viral load demonstrated to be an appropriate method to quantify plasma hiv-rna. this tool can help to define the condition of a particular patient to predict clinical course of the disease and to assess the response to the treatment.
Virus de hepatitis C en poblaciones de riesgo a adquirir la infección: Venezuela Hepatitis C virus in populations at risk for infection: Venezuela
F. Monsalve-Castillo,L. Gómez-Gamboa,A. Albillos,M. álvarez-Mon
Revista Espa?ola de Enfermedades Digestivas , 2007,
Abstract: Objetivo: conocer la prevalencia del virus de hepatitis C en diferentes poblaciones de riesgo a adquirir la infección de la ciudad de Maracaibo, Venezuela. Método: la presente investigación comprendió un estudio de tipo descriptivo y transversal, cuyas variables fueron evaluadas por el análisis de correlación de Pearson. Se seleccionaron 100 drogadictos, 47 trabajadoras sexuales y 50 hemodializados, para un total de 197 individuos. Como único criterio de inclusión se tomó el hecho de presentar riesgo de contraer la infección por el virus de hepatitis C. Para la detección de anticuerpos contra el virus se utilizó la técnica de inmunoensayo enzimático de cuarta generación (Innotest HCV Ab IV). Toda muestra reactiva se confirmó por el método de inmunoblot recombinante de tercera generación (INNO-LIA HCV Ab III ), ambos de Innogenetics Lab (Bélgica). La detección del genoma viral (ARN) se realizó en aquellas muestras reactivas por ELISA e INNO-LIA por la técnica de reacción en cadena de la polimerasa, HCV-fast de Pharma Gen. Resultados: se encontró uno por ciento de prevalencia de hepatitis C en la población de drogadictos y ausencia de infección o contacto previo con el virus en trabajadoras sexuales y pacientes en hemodiálisis. Conclusiones: en el presente estudio se se ala la baja prevalencia de la infección por el virus de hepatitis C en poblaciones de riesgo a adquirir la infección, por lo que se considera que esta infección no representa un problema de salud en estas poblaciones de la ciudad de Maracaibo, Venezuela. Objective: the aim of this study was to establish the prevalence of hepatitis C virus infection in different populations at risk for infection. Method: this was a descriptive, transversal study whose variables were evaluated by Pearson...s correlation analysis. Different populations were selected: 100 drug users, 47 sex workers, and 50 hemodialysis patients for a total of 197 individuals. The only inclusion criterion was the apparent risk of acquiring this viral infection. The presence of antibodies against virus was examined by ELISA IV (Innotest HCV Ab IV). Reactive samples were then tested using a recombinant assay (INNO-LIA HCV Ab III), both from Innogenetics N. V. (Belgium). The presence of viral RNA was determined in all ELISA and immunoblot-reactive samples by a nested polymerase chain reaction method (HCV-fast of Pharma Gen). Results: a prevalence of 1% was found in drug users, and absence of infection or previous contact with the virus in sex workers and hemodialysis patients. Conclusions: this study shows a very low prevalence of
Cryptosporidium sp. y otros parásitos intestinales en ni?os menores de 5 a?os con diarrea y su relación con las pruebas coprocualitativas
Bracho M,ángela; Rivero-Rodríguez,Zulbey; Salazar F,Solneumar; Jaimes R,Patricia; Semprún T,Mariana; Monsalve-Castillo,Francisca; Villalobos P,Rafael;
Kasmera , 2010,
Abstract: to determine the presence of cryptosporidium sp. and other intestinal parasites, as well as their relation to coproqualitative tests, fecal samples were analyzed from 100 children ranging from 3 months to 5 years old, who attended the autonomous service parasitology laboratory at the university hospital of maracaibo (sahum) with a clinical diagnosis of diarrhea. these samples were subjected to macroscopic and microscopic examination with ssf (0.85%) and iodine, kinyoun stain for the detection of intestinal coccidia, coproqualitative tests (occult blood, reducing sugars and ph). of all the samples studied, 12% evidenced parasites. the species found were cryptosporidium sp. (4%), ascaris lumbricoides (1%), trichuris trichiura (2%) pentatrichomonas hominis (1%), giardia lamblia and blastocystis hominis at (4%). there was no correlation between the coproqualitative tests and the parasitic species identified, nor was there any relationship between parasitosis and gender. cryptosporidium sp. and giardia lamblia were the most frequent pathogenic parasites in children ≤ 2 years old.
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