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1.
Exp Parasitol ; 132(4): 424-33, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23043979

RESUMEN

Precision-cut liver slices (PCLS) are mainly used to evaluate hepatotoxicity and metabolism of chemicals, as well as to study mechanisms of liver damage and repair. However, recently they have been used as a system to study amoebic infections. The aim of this study was to validate this model as an alternative for experimental amoebic liver absess (ALA) in animals. To do this, the PCLS was analyzed for the expression of amoebapore and cysteine proteinases 1 and 5, three of the most studied virulence factors of Entamoeba histolytica, as well as the induction of apoptosis and cytokines production in response to the ex vivo infection. PCHLS were prepared with the Brendel-Vitron tissue slicer and then, infected with 200,000 trophozoites of E. histolytica. Samples were taken at 0, 6, 12, 18, and 24 h and compared to control non-infected slices. Morphological studies were performed in order to verify the infection; while apoptosis was studied by TUNEL and PAS techniques. The expression of cysteine proteinases (1 and 5), and amoebapore, was analyzed by real-time PCR. By using ELISA assays, the production of cytokines was also studied. PCHLS were found to be a reproducible infection system, and E. histolytica caused the expression of cysteine proteinases and amoebapore in infected slices. At the same time, trophozoites induce release of cytokines and apoptotic death of the hepatocytes close to them. PCHLS represent a new and suitable alternative model to study the pathogenesis of hepatic amoebiasis.


Asunto(s)
Apoptosis , Citocinas/metabolismo , Entamoeba histolytica/patogenicidad , Hígado/parasitología , Factores de Virulencia/metabolismo , Alternativas a las Pruebas en Animales/métodos , Animales , Cricetinae , Proteasas de Cisteína/genética , Proteasas de Cisteína/metabolismo , Modelos Animales de Enfermedad , Entamoeba histolytica/inmunología , Regulación Enzimológica de la Expresión Génica , Etiquetado Corte-Fin in Situ , Hígado/inmunología , Hígado/patología , Masculino , Mesocricetus , Reacción del Ácido Peryódico de Schiff , Reacción en Cadena en Tiempo Real de la Polimerasa , Factores de Virulencia/análisis , Factores de Virulencia/genética
2.
Viruses ; 14(6)2022 05 27.
Artículo en Inglés | MEDLINE | ID: mdl-35746637

RESUMEN

In this study, we analyzed the sequences of SARS-CoV-2 isolates of the Delta variant in Mexico, which has completely replaced other previously circulating variants in the country due to its transmission advantage. Among all the Delta sublineages that were detected, 81.5 % were classified as AY.20, AY.26, and AY.100. According to publicly available data, these only reached a world prevalence of less than 1%, suggesting a possible Mexican origin. The signature mutations of these sublineages are described herein, and phylogenetic analyses and haplotype networks are used to track their spread across the country. Other frequently detected sublineages include AY.3, AY.62, AY.103, and AY.113. Over time, the main sublineages showed different geographical distributions, with AY.20 predominant in Central Mexico, AY.26 in the North, and AY.100 in the Northwest and South/Southeast. This work describes the circulation, from May to November 2021, of the primary sublineages of the Delta variant associated with the third wave of the COVID-19 pandemic in Mexico and highlights the importance of SARS-CoV-2 genomic surveillance for the timely identification of emerging variants that may impact public health.


Asunto(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiología , Humanos , México/epidemiología , Pandemias , Filogenia , SARS-CoV-2/genética
3.
Exp Parasitol ; 126(2): 117-25, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20412797

RESUMEN

Entamoeba histolytica is the etiological agent of amoebiasis, the second cause of global morbidity and mortality due to parasitic diseases in humans. In approximately 1% of the cases, amoebas penetrate the intestinal mucosa and spread to other organs, producing extra-intestinal lesions, among which amoebic liver abscess (ALA) is the most common. To study ALA, in vivo and in vitro models are used. However, animal models may pose ethical issues, and are time-consuming and costly; and cell cultures represent isolated cellular lineages. The present study reports the infection of precision-cut hamster liver slices with Entamoeba histolytica trophozoites. The infection time-course, including tissue damage, parallels findings previously reported in the animal model. At the same time amoebic virulence factors were detected in the infected slices. This new model to study ALA is simple and reproducible, and employs less than 1/3 of the hamsters required for in vivo analyses.


Asunto(s)
Modelos Animales de Enfermedad , Entamoeba histolytica/patogenicidad , Absceso Hepático Amebiano/parasitología , Hígado/parasitología , Factores de Virulencia/análisis , Actinas/análisis , Actinas/genética , Animales , Cricetinae , Proteasas de Cisteína/análisis , Proteasas de Cisteína/genética , ADN Complementario/análisis , Entamoeba histolytica/genética , Canales Iónicos/análisis , Canales Iónicos/genética , Absceso Hepático Amebiano/patología , Masculino , Mesocricetus , Reacción en Cadena de la Polimerasa , Proteínas Protozoarias/análisis , Proteínas Protozoarias/genética , ARN Protozoario/genética , ARN Protozoario/aislamiento & purificación , Técnicas de Cultivo de Tejidos , Virulencia , Factores de Virulencia/genética
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