271 research outputs found

    Production of American lettuce cultivars under different colored shade nets

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    Email: [email protected] (autor de correspondencia)Shading nets are used to reduce the amount of radiant energy reaching crops. The objective of the work was to compare the influence of black and red shading nets on the production of nine American lettuce cultivars in the Autumn period under the conditions of the Central Department of Paraguay. The experiment was carried out in the Experimental Field of the Departmental Agronomic Center (CAD) in the Municipality of Julián Augusto Saldívar. The treatments consisted of the combination of two types of shading netting (red with 35% shade and black with 35% shade) and nine cultivars of American lettuce (Julia, Dora, Angelina, Tainá, Sun Valley, Betty, Lucy Brown, Mara, and Serena) totaling 18 treatments. The experiment consisted in a complete randomized block design, arranged in split blocks 2×9 (the color of shading netting was considered the main plot, and the lettuce cultivars as the secondary plot) with four repetitions. Each experimental unit consisted of four crop rows with seven plants. Plant diameter, plant height, head diameter and height, commercial number of leaves per plant, fresh mass, and commercial productivity were evaluated. The data were subjected to analysis of variance, and when differences were found, the means were compared by the Scott-Knott test at 5% probability. The results indicate that using the red netting with the Serena and Dora cultivars provides greater fresh mass and commercial production.Las mallas de sombra se utilizan para reducir la cantidad de energía radiante que llega a los cultivos. El objetivo de este trabajo fue comparar la influencia de las mallas sombreadoras negras y rojas en la producción de nueve cultivares de lechuga americana en el período otoñal en las condiciones del Departamento Central del Paraguay. El experimento se realizó en el Campo Experimental del Centro Agronómico Departamental (CAD), en el municipio de Julián Augusto Saldívar. Los tratamientos consistieron en una combinación de dos tipos de malla sombra (roja con 35% de sombra y negra con 35% de sombra) y nueve cultivares de lechuga americana (Julia, Dora, Angelina, Tainá, Sun Valley, Betty, Lucy Brown, Mara y Serena) totalizando 18 tratamientos. El diseño experimental fue en franjas en bloques completos al azar de 2×9 (las mallas de color fueron consideradas la parcela principal y los cultivares la parcela secundaria) y cuatro repeticiones. Cada unidad experimental constó de cuatro hileras de cultivo, con siete plantas. Se evaluó diámetro de planta, altura de planta, diámetro y altura de cabeza, número comercializable de hojas por planta, masa fresca y rendimiento comercializable. Los resultados fueron sometidos a análisis de varianza y, cuando se encontraron diferencias significativas, se usó la prueba de Scott-Knott al 5% de probabilidad para la comparación de medias. Los resultados indican que el uso de la red roja con los cultivares Serena y Dora proporciona mayor producción de masa fresca y comercializable.Consejo Nacional de Ciencia y TecnologíaPrograma Paraguayo para el Desarrollo de la Ciencia y Tecnología. Proyectos de investigación y desarroll

    Primer reporte de queratitis por Nocardia brasiliensis en Paraguay

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    La queratitis producida por Nocardia spp es raramente reportada en el mundo por lo que su incidencia no está aún bien establecida. En el presente estudio se reporta el primer caso de queratitis por Nocardia brasiliensis en Paraguay en un paciente de sexo masculino, de profesión jardinero, procedente de la ciudad de Asunción, y con antecedente de traumatismo con rama de arbusto quince días antes de la consulta. El paciente acude al servicio de Oftalmología del Hospital de Clínicas, debido a ojo rojo, agudeza visual disminuida e intenso dolor en el ojo izquierdo con una semana de evolución. Se realiza tratamiento con la aplicación de colirio reforzado de gentamicina 14 mg/ml y cefazolina 50 mg/ml, cada una hora, observándose mejoría de los síntomas y de la agudeza visual a los 10 días de seguimiento. La evolución clínica en queratitis a Nocardia spp es buena siempre que el diagnóstico etiológico se realice sin demora y correctamente. Es muy importante diferenciar los bordes de las lesiones de la úlcera de córnea producidas por hongos, bacterias filamentosas y otras bacterias, además considerar la presencia de lesiones satélites

    Mitochondrial Uncoupling Inhibits p53 Mitochondrial Translocation in TPA-Challenged Skin Epidermal JB6 Cells

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    The tumor suppressor p53 is known to be able to trigger apoptosis in response to DNA damage, oncogene activation, and certain chemotherapeutic drugs. In addition to its transcriptional activation, a fraction of p53 translocates to mitochondria at the very early stage of apoptosis, which eventually contributes to the loss of mitochondrial membrane potential, generation of reactive oxygen species (ROS), cytochrome c release, and caspase activation. However, the mitochondrial events that affect p53 translocation are still unclear. Since mitochondrial uncoupling has been suggested to contribute to cancer development, herein, we studied whether p53 mitochondrial translocation and subsequent apoptosis were affected by mitochondrial uncoupling using chemical protonophores, and further verified the results using a siRNA approach in murine skin epidermal JB6 cells. Our results showed that mitochondrial uncoupling blocked p53 mitochondrial translocation induced by 12-O-tetradecanoylphorbol 13-acetate (TPA), a known tumor promoter to induce p53-mediated apoptosis in skin carcinogenesis. This blocking effect, in turn, led to preservation of mitochondrial functions, and eventually suppression of caspase activity and apoptosis. Moreover, uncoupling protein 2 (UCP2), a potential suppressor of ROS in mitochondria, is important for TPA-induced cell transformation in JB6 cells. UCP2 knock down cells showed enhanced p53 mitochondrial translocation, and were less prone to form colonies in soft agar after TPA treatment. Altogether, our data suggest that mitochondrial uncoupling may serve as an important regulator of p53 mitochondrial translocation and p53-mediated apoptosis during early tumor promotion. Therefore, targeting mitochondrial uncoupling may be considered as a novel treatment strategy for cancer

    Polyfunctional T cell responses in children in early stages of chronic Trypanosoma cruzi infection contrast with monofunctional responses of long-term infected adults

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    Background: Adults with chronic Trypanosoma cruzi exhibit a poorly functional T cell compartment, characterized by monofunctional (IFN-γ-only secreting) parasite-specific T cells and increased levels of terminally differentiated T cells. It is possible that persistent infection and/or sustained exposure to parasites antigens may lead to a progressive loss of function of the immune T cells. Methodology/Principal Findings: To test this hypothesis, the quality and magnitude of T. cruzi-specific T cell responses were evaluated in T. cruzi-infected children and compared with long-term T. cruzi-infected adults with no evidence of heart failure. The phenotype of CD4+ T cells was also assessed in T. cruzi-infected children and uninfected controls. Simultaneous secretion of IFN-γ and IL-2 measured by ELISPOT assays in response to T. cruzi antigens was prevalent among T. cruzi-infected children. Flow cytometric analysis of co-expression profiles of CD4+ T cells with the ability to produce IFN-γ, TNF-α, or to express the co-stimulatory molecule CD154 in response to T. cruzi showed polyfunctional T cell responses in most T. cruzi-infected children. Monofunctional T cell responses and an absence of CD4+TNF-α+-secreting T cells were observed in T. cruzi-infected adults. A relatively high degree of activation and differentiation of CD4+ T cells was evident in T. cruzi-infected children. Conclusions/Significance: Our observations are compatible with our initial hypothesis that persistent T. cruzi infection promotes eventual exhaustion of immune system, which might contribute to disease progression in long-term infected subjects.Fil: Albareda, María Cecilia. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: de Rissio, Ana María. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; ArgentinaFil: Tomas, Gonzalo. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; ArgentinaFil: Serjan, Alicia. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Juan A. Fernández"; ArgentinaFil: Alvarez, María Gabriela. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Viotti, Rodolfo Jorge. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Fichera, Laura Edith. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Esteva, Mónica Inés. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; ArgentinaFil: Potente, Daniel Fernando. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Armenti, Alejandro. Provincia de Buenos Aires. Ministerio de Salud. Hospital Interzonal de Agudos "Eva Perón"; ArgentinaFil: Tarleton, Rick L.. University of Georgia; Estados UnidosFil: Laucella, Susana Adriana. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud. Instituto Nacional de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Triterpenoids Display Single Agent Anti-tumor Activity in a Transgenic Mouse Model of Chronic Lymphocytic Leukemia and Small B Cell Lymphoma

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    The synthetic triterpenoid 2-Cyano-3,12-Dioxooleana-1,9-Dien-28-Oic Acid (CDDO) and derivatives display anti-tumor activity against a variety of cultured tumor cell lines and in mouse xenografts. In this report, we have studied the effects of CDDO and its imidazolide derivative (CDDO-Im) on chronic lymphocytic leukemia (CLL), using patients' CLL cells and a mouse model of CLL and small B cell lymphoma (SBL).CDDO and CDDO-Im efficiently induced apoptosis of malignant human and mouse B-cells ex vivo, although CDDO-Im was over 10-fold more potent than CDDO. Treating mice with CLL/SBL with liposome-formulated CDDO or CDDO-Im resulted in significant reductions of B cells in blood, spleen and lung. CDDO-Im was shown to be more potent than CDDO, while treatment with empty liposomes had no impact on disease. CDDO-Im treatment initially resulted in an increase of circulating B cells, which correlates with a reduction in resident lymphocytes in spleen, and lungs, suggesting that CDDO-Im induces mobilization of tumor cells from lymphoid organs and infiltrated tissues into the circulation. Analysis of blood cells recovered from treated mice also showed that CDDO-Im is a potent inducer of tumor cells death in vivo. Furthermore, CDDO-Im efficiently eradicated mouse CLL/SBL cells but had little effect on the viability of normal B and T cells in vivo.The presented data demonstrate that triterpenoids CDDO and CDDO-Im reduce leukemia and lymphoma burden in vivo in a transgenic mouse model of CLL/SBL, and support the clinical testing of CDDO-based synthetic triterpenoids in patients with CLL

    Evaluación clínica preliminar del efecto antiparasitario de Stevia rebaudiana Bertoni (ka`a he ê) en adultos y niños

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    La parasitosis gastrointestinal es una enfermedad que se da preferentemente en la niñez y enadultos inmunocomprometidos. Los tratamientos actuales son, en general, eficaces, pero lacreciente resistencia a los antiparasitarios obliga a la búsqueda de nuevas drogas con urgencia.Este estudio tiene el propósito de evaluar preliminarmente la efectividad de Stevia rebaudianaBertoni como antiparasitário. Se realizó un ensayo clínico aleatorizado a ciego simple, con 22adultos y 134 niños (6-18 años), todos parasitados con helmintos y/o protozoarios. Lostratamientos asignados al azar consistieron en comprimidos de S. rebaudiana (SRB) omebendazol-tinidazol (MBZ-TNZ), ambos en preparaciones farmacéuticas comerciales. En losadultos SRB y MBZ-TNZ redujeron en forma similar la infección por protozoarios y helmintos, y elnúmero de eventos adversos informados para el tratamiento convencional fue mayor que para SRB(p<0,02). Atendiendo a esos resultados se amplió la evaluación a 134 niños portadores deparásitos intestinales, de los que 113 (99,3%) presentaron protozoarios y 28 (20,8%) helmintos,mayoritariamente en co infección. S. rebaudiana redujo significativamente (p<0,001) la frecuenciade global de infección por protozoarios (74,5%) en los niños frente a lo obtenido con MBZ-TNZ(40,7%), destacando la negativización de Giardia lamblia.que resultó el doble con SRB de loobservado con MBZ-TNZ (p<0,001). SRB redujo la frecuencia de helmintos en 70,6% de manerasimilar a MBZ-TNZ (p>0,05). No se registraron efectos adversos asociados a los tratamientos a losniños/as. Los resultados animan a proseguir la evaluación de SRB como potencial agenteantiparasitario

    Inhibition of fatty acid metabolism ameliorates disease activity in an animal model of multiple sclerosis

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    Multiple sclerosis is an inflammatory demyelinating disease of the central nervous system and a leading cause of neurological disability. The complex immunopathology and variable disease course of multiple sclerosis have limited effective treatment of all patients. Altering the metabolism of immune cells may be an attractive strategy to modify their function during autoimmunity. We examined the effect of inhibiting fatty acid metabolism in experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. Mice treated with an inhibitor of carnitine palmitoyltransferase 1 (CPT-1), the rate-limiting enzyme in the beta-oxidation of fatty acids, showed a reduction in disease severity as well as less inflammation and demyelination. Inhibition of CPT-1 in encephalitogenic T-cells resulted in increased apoptosis and reduced inflammatory cytokine production. These results suggest that disruption of fatty acid metabolism promotes downregulation of inflammation in the CNS and that this metabolic pathway is a potential therapeutic target for multiple sclerosis

    Cellular Model of Warburg Effect Identifies Tumor Promoting Function of UCP2 in Breast Cancer and Its Suppression by Genipin

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    The Warburg Effect is characterized by an irreversible injury to mitochondrial oxidative phosphorylation (OXPHOS) and an increased rate of aerobic glycolysis. In this study, we utilized a breast epithelial cell line lacking mitochondrial DNA (rho0) that exhibits the Warburg Effect associated with breast cancer. We developed a MitoExpress array for rapid analysis of all known nuclear genes encoding the mitochondrial proteome. The gene-expression pattern was compared among a normal breast epithelial cell line, its rho0 derivative, breast cancer cell lines and primary breast tumors. Among several genes, our study revealed that over-expression of mitochondrial uncoupling protein UCP2 in rho0 breast epithelial cells reflects gene expression changes in breast cancer cell lines and in primary breast tumors. Furthermore, over-expression of UCP2 was also found in leukemia, ovarian, bladder, esophagus, testicular, colorectal, kidney, pancreatic, lung and prostate tumors. Ectopic expression of UCP2 in MCF7 breast cancer cells led to a decreased mitochondrial membrane potential and increased tumorigenic properties as measured by cell migration, in vitro invasion and anchorage independent growth. Consistent with in vitro studies, we demonstrate that UCP2 over-expression leads to development of tumors in vivo in an orthotopic model of breast cancer. Genipin, a plant derived small molecule, suppressed the UCP2 led tumorigenic properties, which were mediated by decreased reactive oxygen species and down-regulation of UCP2. However, UCP1, 3, 4 and 5 gene expression was unaffected. UCP2 transcription was controlled by SMAD4. Together, these studies suggest a tumor-promoting function of UCP2 in breast cancer. In summary, our studies demonstrate that i) the Warburg Effect is mediated by UCP2; ii) UCP2 is over-expressed in breast and many other cancers; iii) UCP2 promotes tumorigenic properties in vitro and in vivo and iv) genipin suppresses the tumor promoting function of UCP2

    14-3-3 zeta is a molecular target in guggulsterone induced apoptosis in Head and Neck cancer cells

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    <p>Abstract</p> <p>Background</p> <p>The five-year survival rates for head and neck squamous cell carcinoma (HNSCC) patients are less than 50%, and the prognosis has not improved, despite advancements in standard multi-modality therapies. Hence major emphasis is being laid on identification of novel molecular targets and development of multi-targeted therapies. 14-3-3 zeta, a multifunctional phospho-serine/phospho-threonine binding protein, is emerging as an effector of pro-survival signaling by binding to several proteins involved in apoptosis (Bad, FKHRL1 and ASK1) and may serve as an appropriate target for head and neck cancer therapy. Herein, we determined effect of guggulsterone (GS), a farnesoid X receptor antagonist, on 14-3-3 zeta associated molecular pathways for abrogation of apoptosis in head and neck cancer cells.</p> <p>Methods</p> <p>Head and neck cancer cells were treated with guggulsterone (GS). Effect of GS-treatment was evaluated using cell viability (MTT) assay and apoptosis was verified by annexin V, DNA fragmentation and M30 CytoDeath antibody assay. Mechanism of GS-induced apoptosis was determined by western blotting and co-IP assays using specific antibodies.</p> <p>Results</p> <p>Using in vitro models of head and neck cancer, we showed 14-3-3 zeta as a key player regulating apoptosis in GS treated SCC4 cells. Treatment with GS releases BAD from the inhibitory action of 14-3-3 zeta in proliferating HNSCC cells by activating protein phosphatase 2A (PP2A). These events initiate the intrinsic mitochondrial pathway of apoptosis, as revealed by increased levels of cytochrome c in cytoplasmic extracts of GS-treated SCC4 cells. In addition, GS treatment significantly reduced the expression of anti-apoptotic proteins, Bcl-2, xIAP, Mcl1, survivin, cyclin D1 and c-myc, thus committing cells to apoptosis. These events were followed by activation of caspase 9, caspase 8 and caspase 3 leading to cleavage of its downstream target, poly-ADP-ribose phosphate (PARP).</p> <p>Conclusion</p> <p>GS targets 14-3-3 zeta associated cellular pathways for reducing proliferation and inducing apoptosis in head and neck cancer cells, warranting its investigation for use in treatment of head and neck cancer.</p

    Withania somnifera Root Extract Enhances Chemotherapy through ‘Priming’

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    Withania somnifera extracts are known for their anti-cancerous, anti-inflammatory and antioxidative properties. One of their mechanisms of actions is to modulate mitochondrial function through increasing oxidative stress. Recently ‘priming’ has been suggested as a potential mechanism for enhancing cancer cell death. In this study we demonstrate that ‘priming’, in HT-29 colon cells, with W. somnifera root extract increased the potency of the chemotherapeutic agent cisplatin. We have also showed the W. somnifera root extract enhanced mitochondrial dysfunction and that the underlying mechanism of ‘priming’ was selectively through increased ROS. Moreover, we showed that this effect was not seen in non-cancerous cells
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