oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 4 )

2019 ( 85 )

2018 ( 129 )

2017 ( 115 )

Custom range...

Search Results: 1 - 10 of 91894 matches for " Rosales-Encina José Luis "
All listed articles are free for downloading (OA Articles)
Page 1 /91894
Display every page Item
Prevalencia de Trypanosoma cruzi en triatominos silvestres de Nuevo León, México
Molina-Garza,Zinnia Judith; Rosales-Encina,José Luis; Galaviz-Silva,Lucio; Molina-Garza,Daniel;
Salud Pública de México , 2007, DOI: 10.1590/S0036-36342007000100006
Abstract: objective: to determine the prevalence of trypanosoma cruzi in triatomines from nuevo león using the standardization of an improved enzyme-linked immunosorbent assay test. materials and methods: from july to september 2005, 52 triatomines were captured in general terán, a municipality located in nuevo león. they were analyzed using optical microscopy (om) and a polymerase chain reaction (pcr), as standards of reference, to develop a technique for detecting the parasite using enzyme-linked immunosorbent assay (elisa). results: using om and pcr, 31 triatomines were found to be positive and 21 negative. using elisa, 27 samples were identified as positive and 25 negative (specificity 100%, sensitivity 87%, negative predictive value 84%, and positive predictive value 100%). the prevalence of infected triatomines was 59.61% with om and pcr, and 51.92% with elisa. our data confirm that the elisa assay in triatomines is a fast, reliable and useful tool. conclusions: since it was possible to simultaneously analyze a large number of samples with high sensibility and specificity values, the elisa test proves to be useful for new epidemiologic studies having a high number of vectors. it is also less expensive than pcr. it is therefore recommended for epidemiological and preventive surveillance programs as a first screening test before conducting a confirmatory test using pcr.
IL-10-IFN-γ Double Producers CD4+ T Cells Are Induced by Immunization with an Amastigote Stage Specific Derived Recombinant Protein of Trypanosoma Cruzi
Yevel Flores-García, José Luis Rosales-Encina, Abhay R. Satoskar, Patricia Talamás-Rohana
International Journal of Biological Sciences , 2011,
Abstract: During the acute phase of infection, T. cruzi replicates extensively and releases immunomodulatory molecules that delay parasite-specific responses mediated by effector T cells. This mechanism of evasion allows the parasite to spread in the host. Parasite molecules that regulate the host immune response during Chagas'disease have not been fully identified. GPI-anchored mucins, glycoinositolphospholipids, and glycoproteins comprise some of the most abundant T. cruzi surface molecules. IL-10 IFN-γ-secreting CD4+ T cells are activated during chronic infections and are responsible for prolonged persistence of parasite and for host protection against severe inflammatory responses. In this work we evaluated the role of rMBP::SSP4 protein of T. cruzi, a recombinant protein derived from a GPI anchored antigen, SSP4, as an immunomodulator molecule, finding that it was able to induce high concentrations of IL-10 and IFN-γ both in vivo and in vitro; during this last condition, both cytokines were produced by IL-10-IFN-γ-secreting CD4+ T cells.
Trypanosoma cruzi SSP4 Amastigote Protein Induces Expression of Immunoregulatory and Immunosuppressive Molecules in Peripheral Blood Mononuclear Cells
Yadira Morán-Utrera,Aracely López-Monteon,José Luis Rosales-Encina,Enrique Méndez-Bolaina,Angel Ramos-Ligonio
Journal of Tropical Medicine , 2012, DOI: 10.1155/2012/829139
Abstract: The acute phase of Chagas' disease in mice and human is marked by states of immunosuppression, in which Trypanosoma cruzi replicates extensively and releases immunomodulatory molecules that delay parasite-specific responses mediated by effector T cells. This mechanism of evasion allows the parasite to spread in the host. Parasite molecules that regulate the host immune response during Chagas’ disease have not been fully identified, particularly proteins of the amastigote stage. In this work, we evaluated the role of the GPI anchored SSP4 protein of T. cruzi as an immunomodulatory molecule in peripheral blood mononuclear cells (PBMCs). rMBP::SSP4 protein was able to stimulate nitric oxide (NO) production. Likewise, rMBP::SSP4 induced the expression of genes and production of molecules involved in the inflammatory process, such as, cytokines, chemokines, and adhesion molecules (CAMs) as determined by RT-PCR and ELISA. These results suggest that the amastigote SSP4 molecule could play a key role in the immunoregulatory and/or immunosuppressive process observed in the acute phase of infection with T. cruzi. 1. Introduction Chagas’ disease is a zoonosis caused by the protozoan parasite Trypanosoma cruzi, and it is a major public health problem in most of Latin America and in particular in Mexico. Indeed, the WHO estimates that about 8–11 million persons are infected worldwide [1]. T. cruzi infects many cell types, including myocytes, fibroblast, vascular endothelial, and smooth muscle cells among other cells. Since the monocyte is a target cell in T. cruzi infection and monocytes play a major role in regulating immune responses, monocyte dysfunction may contribute to host immunosuppression [2]. It has been observed that during the experimental infection with T. cruzi, there is an increased expression of proinflammatory mediators, including cytokines [3], chemokines [4], vascular adhesion molecules [5], and nitric oxide synthase [6] among other molecules [7], which promotes the inflammatory process and vascular damage. There is evidence that immune mechanisms are involved in the pathogenesis of many parasitic infections. The initial stages of the disease are generally characterized by the induction of a nonspecific lymphoproliferation, which is believed to disrupt antigen recognition and interfere with protective immune responses. Paradoxically, in most cases, a state of immunosuppression can be evidenced. This hyporesponsiveness to antigen-specific and polyclonal stimuli in chronic parasitic infections could be related to immunosuppressive cytokines secreted
Prevalencia de anticuerpos contra Trypanosoma cruzi en donadores de sangre del IMSS, Orizaba, Veracruz, México
Ramos-Ligonio Angel,Ramírez-Sánchez Michaía Elián,González-Hernández Juan Carlos,Rosales-Encina José Luis
Salud Pública de México , 2006,
Abstract: OBJETIVO: Determinar la prevalencia de anticuerpos contra Trypanosoma cruzi en donadores del Hospital General Regional del Instituto Mexicano del Seguro Social (IMSS) en la ciudad de Orizaba, Veracruz. MATERIAL Y MéTODOS: Se examinaron muestras de donadores del banco de sangre del Hospital General Regional (HGRO) del IMSS para la búsqueda de antiT. cruzi por ELISA, Western blot e IFI, utilizando una proteína recombinante (MBP::Hsp70) y un extracto crudo de epimastigotes. Las muestras fueron obtenidas entre los meses de octubre de 2001 a enero de 2002. RESULTADOS: Los 420 donadores de sangre analizados fueron seronegativos para HBV, HCV, BrA, VDRL y HIV. Después del tamizaje de los 420 donadores, se identificaron dos individuos seropositivos por las pruebas de ELISA, Western blot e IFI, con una seroprevalencia de 0.48%. CONCLUSIONES: En este estudio se muestran evidencias de seropositividad para T. cruzi en donadores de sangre del HGRO, lo que sugiere la existencia de riesgo de contaminación por transfusión sanguínea. Por tal motivo, es necesario aplicar programas para el tamizaje serológico a través de técnicas inmunológicas con alta sensibilidad y especificidad.
Prevalencia de anticuerpos contra Trypanosoma cruzi en donadores de sangre del IMSS, Orizaba, Veracruz, México
Ramos-Ligonio,Angel; Ramírez-Sánchez,Michaía Elián; González-Hernández,Juan Carlos; Rosales-Encina,José Luis; López-Monteon,Aracely;
Salud Pública de México , 2006, DOI: 10.1590/S0036-36342006000100004
Abstract: objective: to estimate the prevalence of antibodies against trypanosoma cruzi in blood donors from hospital general regional (hgro) of the mexican institute of social security (imss per its abbreviation in spanish). material and methods: between october 2001 and january 2002, blood samples were collected from voluntary donors at the blood bank of the hospital general regional of imss in orizaba; veracruz, mexico. the samples were assayed for anti-t. cruzi by elisa, western blot and ifi, using a recombinant protein (mbp::hsp70), and crude extract from epimastigotes. results: a total of 420 blood donors were studied; two of them were seropositive for elisa, western blot and ifi, with a seroprevalence of 0.48%. conclusions: some blood donors at the hgro hospital were seropositive for t. cruzi, showing the risk of contamination by blood transfusion. routine serologic screening with highly sensitive and specific immunological techniques are needed.
A DNA Vaccine Encoding for TcSSP4 Induces Protection against Acute and Chronic Infection in Experimental Chagas Disease
Minerva Arce-Fonseca, Angel Ramos-Ligonio, Aracely López-Monteón, Berenice Salgado-Jiménez, Patricia Talamás-Rohana, José Luis Rosales-Encina
International Journal of Biological Sciences , 2011,
Abstract: Immunization of mice with plasmids containing genes of Trypanosoma cruzi induces protective immunity in the murine model of Chagas disease. A cDNA clone that codes for an amastigote-specific surface protein (TcSSP4) was used as a candidate to develop a DNA vaccine. Mice were immunized with the recombinant protein rTcSSP4 and with cDNA for TcSSP4, and challenged with bloodstream trypomastigotes. Immunization with rTcSSP4 protein makes mice more susceptible to trypomastigote infection, with high mortality rates, whereas mice immunized with a eukaryotic expression plasmid containing the TcSSP4 cDNA were able to control the acute phase of infection. Heart tissue of gene-vaccinated animals did not show myocarditis and tissue damage at 365 days following infection, as compared with control animals. INF-γ was detected in sera of DNA vaccinated mice shortly after immunization, suggesting the development of a Th1 response. The TcSSP4 gene is a promising candidate for the development of an anti-T. cruzi DNA vaccine.
Expression, Purification, and Evaluation of Diagnostic Potential and Immunogenicity of a Recombinant NS3 Protein from All Serotypes of Dengue Virus
Laura Mónica Álvarez-Rodríguez,Angel Ramos-Ligonio,José Luis Rosales-Encina,María Teresa Martínez-Cázares
Journal of Tropical Medicine , 2012, DOI: 10.1155/2012/956875
Abstract:
Expression, Purification, and Evaluation of Diagnostic Potential and Immunogenicity of a Recombinant NS3 Protein from All Serotypes of Dengue Virus
Laura Mónica álvarez-Rodríguez,Angel Ramos-Ligonio,José Luis Rosales-Encina,María Teresa Martínez-Cázares,Aurora Parissi-Crivelli,Aracely López-Monteon
Journal of Tropical Medicine , 2012, DOI: 10.1155/2012/956875
Abstract: Dengue is one of the major public health concerns in the world. Since all the four serotypes are actively circulating in Mexico, there is a need to develop an efficient diagnosis system to improve case management of the patients. There exist few studies evaluating the use of the NS3 protein as a protective antigen against dengue virus (DENV). In this paper we show the expression of a recombinant NS3 protein from all serotypes of dengue virus (GST-DVNS3-1-4) and report a reliable “in-house detection system” for the diagnosis of dengue infection which was field-tested in a small village (Tezonapa) in the state of Veracruz, Mexico. The fusion proteins were immunogenic, inducing antibodies to be able to recognize to antigens up to a 1?:?3200 dilution. The purified proteins were used to develop an in-house detection system (ELISA) and were further tested with a panel of 239 serum samples. The in-house results were in excellent agreement with the commercial kits with (95%? CI = 0.808–1.061), and (95%? CI = 0.779–0.965) for IgM and IgG, respectively. The agreement between the NS1 antigen detection versus the rNS3 ELISA, (95%? CI = 0.708–0.966), was very good. Thus, these results demonstrate that recombinant NS3 proteins have potential in early diagnosis of dengue infections. 1. Introduction Dengue virus (DENV) infection in America, as in the rest of the world, is increasing dramatically. Currently, Mexico could be considered as an endemic region for dengue since the mosquito vector Aedes aegypti is present in more than 85% of the country [1]. Infection can lead to dengue fever (DF), a self-limiting febrile illness. A more severe form of the disease is dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) with fatal consequences. Dengue consists of four, closely related but antigenically, distinct viral serotypes (DENV1–4) [2]. It is well documented that primary infection with one of the four serotypes confers long-lasting immunity to that specific serotype. However, secondary infection with a different serotype is associated with an increased risk of developing DHF where an antibody-dependent enhancement (ADE) of infection is associated with the pathophysiological mechanisms of DHF [3, 4]. The viral genome contains a single open reading frame that codes for a polyprotein of 3391 amino acids, which is processed into 10 individual proteins. Three of these proteins are structural (membrane (M), capsid (C), and envelope (E)) and 7 of them are nonstructural (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5) [5–7]. The cleavage of this polyprotein, which represents an
Antibody delivery into viable epimastigotes of Trypanosoma cruzi as a tool to study the parasite biology  [PDF]
Karla Y. Acosta-Viana, Huchin-Cetz Julio, Jimenez-Coello Matilde, Guzman-Marin Eugenia, Jose L. Rosales-Encina
Advances in Bioscience and Biotechnology (ABB) , 2013, DOI: 10.4236/abb.2013.46095
Abstract:

American trypanosomiasis is a zoonosis of worldwide medical importance and currently there is no effective treatment in chronic patients, hence the importance of the study of protein function of the parasite with the objective of finding new drug targets and to know better the biology of the agent causal (Trypano-soma cruzi). T. cruzi is an RNAi-negative parasite, therefore the silencing genes strategies by RNAi is not possible; for that reason, antibodies may be taken as a tool for studying the parasite proteins function by blocking these molecules with specific antibodies. The aim of this work was to establish a methodology for antibody delivery (antibody transfection) into viable parasites. We used anti-cyclin-A antibody (human origin) in western blot assay with epimastigote of T. cruzi proteins and this recognized a ~55 kDa polypeptide. Several methods for antibody transfection (electroporation, saponin permeabilization and a lipid-based formulation) were tested. The first two methods were unsuccessful. In electroporation was impossible to visualize the antibody inside parasites and with saponin permeabilization, antibodies were successfully introduced, but with loss of parasites viability. The lipid-based formulation method forms noncovalent complexes with antibodies. These complexes are internalized by cells and antibodies are released into the cytoplasm. With this method, a successful antibody delivery was achieved. Anti-cyclin antibodies were visualized in the cytoplasm from fixed transfected parasites (immunofluorescence assays). At 24 h post-transfection, parasites maintained their viability (90%) and were able to arrest the cell cycle in G0/G1-phase of cultured epimastigotes (cell population increased in G0/G1-phase from 50.5% to 66.2% and decreased in S-phase from 47.2% to 26%). It was also observed that anti-cyclin-A antibodies inhibit the

Liver Lead Levels in Snow Goose (Chen caerulescens) in a Wetland near the City of Durango, Mexico  [PDF]
Martín Emilio Pereda-Solís, Alicia Zulema Cárdenas González, José Hugo Martínez Guerrero, Luis Francisco Sánchez Anguiano, Federico Rosales Alférez
Open Journal of Animal Sciences (OJAS) , 2015, DOI: 10.4236/ojas.2015.51004
Abstract: The use of lead in ammunition for hunting exposes waterfowl to lead poisoning (plumbism) by accidental consumption of shotgun pellets. To test this hypothesis we sampled 18 liver tissue samples of Snow Goose (Chen caerulescens) collected during the 2012-2013 hunting season in a wetland near the city of Durango, Mexico. We quantified liver lead levels using an atomic absorption spectrophotometer and portions of liver were fixed and stained for their histological study. Average lead concentration (in dry weight) were under the normal range (mean = 0.73 ± 0.2, standard error) which do not represent any risk of poisoning. Liver tissue injuries were not observed in the histopathological analysis, suggesting no reaction to a xenobiotic agent such as lead. Gastrointestinal content analysis showed lead pellet in the gizzard of one individual, but we could not find a relationship between pellet ingestion and lead concentration in the liver. Although the results did not provide evidences of lethal or sublethal effects caused by lead poisoning, they show a possible risk due to the presence of lead pellets in the digestive tract.
Page 1 /91894
Display every page Item


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