367 research outputs found

    On the Lagrange-Dirichlet converse in dimension three

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    Consider a mechanical system with a real analytic potential. We prove that in dimension three, there is an open and dense subset of the set of non strict local minimums of the potential such that every one of its points is a Lyapunov unstable equilibrium point.Comment: 44 page

    Astrocyte Apoptosis and HIV Replication Are Modulated in Host Cells Coinfected with Trypanosoma cruzi

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    The protozoan Trypanosoma cruzi is the etiological agent of Chagas disease. In immunosuppressed individuals, as it occurs in the coinfection with human immunodeficiency virus (HIV), the central nervous system may be affected. In this regard, reactivation of Chagas disease is severe and often lethal, and it accounts for meningoencephalitis. Astrocytes play a crucial role in the environment maintenance of healthy neurons; however, they can host HIV and T. cruzi. In this report, human astrocytes were infected in vitro with both genetically modified-pathogens to express alternative fluorophore. As evidenced by fluorescence microscopy and flow cytometry, HIV and T. cruzi coexist in the same astrocyte, likely favoring reciprocal interactions. In this context, lower rates of cell death were observed in both T. cruzi monoinfected-astrocytes and HIV-T. cruzi coinfection in comparison with those infected only with HIV. The level of HIV replication is significantly diminished under T. cruzi coinfection, but without affecting the infectivity of the HIV progeny. This interference with viral replication appears to be related to the T. cruzi multiplication rate or its increased intracellular presence but does not require their intracellular cohabitation or infected cell-to-cell contact. Among several Th1/Th2/Th17 profile-related cytokines, only IL-6 was overexpressed in HIV-T. cruzi coinfection exhibiting its cytoprotective role. This study demonstrates that T. cruzi and HIV are able to coinfect astrocytes thus altering viral replication and apoptosis.Fil: Urquiza, Javier Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Burgos, Juan Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Ojeda, Diego Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Pascuale, Carla Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Leguizamon, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Quarleri, Jorge Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentin

    Molecular diagnosis and typing of Trypanosoma cruzi populations and lineages in cerebral Chagas disease in a patient with AIDS

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    Trypanosoma cruzi DNA was amplified from an intracranial biopsy and peripheral blood of an HIV patient with encephalitis; this episode was indicative of AIDS and congenital Chagas disease. The analysis of a microsatellite locus revealed a multiclonal parasite population at the brain lesion with a more complex minicircle signature than that profiled in blood using restriction fragment length polymorphism (RFLP)-PCR and low stringency single primer (LSSP) PCR. Interestingly, different sublineages of T. cruzi II were detected in blood and brain by means of spliced-leader and 24s ribosomal-DNA amplifications. Quantitative-competitive PCR monitored the decrease of parasitic load during treatment and secondary prophylaxis with benznidazole. The synergy between parasiticidal plus antiretroviral treatments probably allowed the patient a longer survival than usually achieved in similar episodes. This is the first case report demonstrating a differential distribution of natural parasite populations and sublineages in Chagas disease reactivation, showing the proliferation of cerebral variants not detectable in peripheral blood.Fil: Burgos, Juan Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Bergher, Sandra B.. Gobierno de la Ciudad de Buenos Aires. Hospital "Ignacio Pirovano"; ArgentinaFil: Freitas, Jorge M.. Universidade Federal de Minas Gerais; BrasilFil: Bisio, Margarita María Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Altcheh, Jaime Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Teijeiro, Ricardo. Gobierno de la Ciudad de Buenos Aires. Hospital "Ignacio Pirovano"; ArgentinaFil: Begher, Sandra B.. Gobierno de la Ciudad de Buenos Aires. Hospital "Ignacio Pirovano"; ArgentinaFil: Freilij, Hector León. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Deccarlini, Florencia. Gobierno de la Ciudad de Buenos Aires. Hospital "Ignacio Pirovano"; ArgentinaFil: Levalle, Jorge. Gobierno de la Ciudad de Buenos Aires. Hospital "Ignacio Pirovano"; ArgentinaFil: Lopez Alcoba, Horacio. Gobierno de la Ciudad de Buenos Aires. Hospital "Ignacio Pirovano"; ArgentinaFil: Burgos, Juan Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Levin, Mariano Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Duffy, Tomás. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Macedo, Andrea M.. Universidade Federal de Minas Gerais; BrasilFil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin

    Inactive trans-sialidase expression in iTS-null Trypanosoma cruzi generates virulent trypomastigotes

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    Disclosing virulence factors from pathogens is required to better understand the pathogenic mechanisms involved in their interaction with the host. In the case of Trypanosoma cruzi several molecules are associated with virulence. Among them, the trans-sialidase (TS) has arisen as one of particular relevance due to its effect on the immune system and involvement in the interaction/invasion of the host cells. The presence of conserved genes encoding for an inactive TS (iTS) isoform is puzzlingly restricted to the genome of parasites from the Discrete Typing Units TcII, TcV, and TcVI, which include highly virulent strains. Previous in vitro results using recombinant iTS support that this isoform could play a different or complementary pathogenic role to that of the enzymatically active protein. However, direct evidence involving iTS in in vivo pathogenesis and invasion is still lacking. Here we faced this challenge by transfecting iTS-null parasites with a recombinant gene that allowed us to follow its expression and association with pathological events. We found that iTS expression improves parasite invasion of host cells and increases their in vivo virulence for mice as shown by histopathologic findings in heart and skeletal muscle.Fil: Pascuale, Carla Antonela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Burgos, Juan Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Postan, Miriam. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”. Instituto Nacional de Parasitología "Dr. Mario Fatala Chaben”; ArgentinaFil: Lantos, Andrés Bernardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Bertelli, Adriano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Campetella, Oscar Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Leguizamon, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas; Argentin

    Characterization of Jatropha curcas accessions based in plant growth traits and oil quality

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    Variability in growth and reproductive characteristics, seed traits, quality and oil content of six accessions of Jatropha curcas growing in Murcia (Spain) under greenhouse conditions were analysed. Differences were found among accessions in branch length, ratio female to male flowers (F/M), productions, seed weight, endosperm weight, percentage of endosperm and percentage of aborted seeds oil contents, fatty acids composition and quality indexes of the biodiesel. Two genotypes (8-8 and 6-3) have shown a good vigor plant, the best F/M ratio, and appropriate average productions. In addition, these accessions showed the highest average single seed weights, and the best average endosperm weights. The highest total seed oil percentages were observed in the accessions 4-5 (42.42 ± 0.26), 6-3 (41.51 ± 0.20), and 8-8 (40.41 ± 0.73), whereas percentages lower than 30% were recorded in the others. The percentage of endosperm oil ranged from 42.72 ± 0.98% to 65.71 ± 0.36%. In relation to the fatty acids composition, the highest monounsaturated fatty acids percentages with the highest concentration of oleic acid and the lowest concentration of linolenic acid were observed in three genotypes (4-5, 8-8 and 6-3). The biodiesel obtained from these accessions presented high cetane number and low iodine value, which indicates the good ignition quality and stability of the oil. The knowledge of plant growth parameters and oil quality of the studied genotypes could be useful to choose the appropriate ones to be grown under subtropical climatic conditions or to be used as parents in a breeding program

    Metabolism is altered in the process of drug resistance acquisition

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    Cells need energy to survive, therefore, they increase the different pathways available to obtain it. This suggests that the cell, due to the cytotoxicity of bleomycin, increases the routes to obtain energy. For this reason, GPM1 could be a good candidate as bleomycin chemo-resistance biomarker. Knowing of the homologous gene in humans facilitates more studies of the expression of this protein in tumors.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Analysis of Immunotherapy in ovarian cancer

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    There are many Immunotherapy methods in ovarian cancer. Even the immune cells themselves can be part of the immunotherapy. But also at molecular level, the immunotherapy can be applied, like maintaining damage in DNA or inhibiting certain pathways. Nevertheless, there is still needed to understand the mechanism of immunotherapy.Campus de Excelencia Internacional Andalucía Tech

    Analysis of Immunotherapy in Triple negative breast cancer

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    TNBC cancer is complicated, most is about PD-L1 mechanism. Too many kinds of immunotherapy have been developed to treat TNCB. Nowadays, is complicated a fast and 100% accurate treatment for TNBC, because of cancer complications like metastasis. Nevertheless, metastasis is still being researched to prevent it and assure a better immunotherapy. Also, the immunotherapies must be improved too.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
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