2,534 research outputs found

    Metabolic channeling of phe for lignin biosynthesis in maritime pine

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    Phenylalanine (Phe) is the main precursor of phenylpropanoids biosynthesis in plants. This vast family of Phe-derived compounds can represent more than 30% of captured photosynthetic carbon, playing essential roles in plants such as cell wall components, defense molecules, pigments and flavors. In addition to its physiological importance, phenylpropanoids and particularly lignin, a component of wood, are targets in plant biotechnology. The arogenate pathway has been proposed as the main pathway for Phe biosynthesis in plants (Maeda et al., 2010). The final step in Phe biosynthesis, catalyzed by the enzyme arogenate dehydratase (ADT), has been considered as a key regulatory point in Phe biosynthesis, due to its key branch position in the pathway, the multiple isoenzymes identified in plants and the existence of a feedback inhibition mechanism by Phe. So far, the regulatory mechanisms underlying ADT genes expression have been poorly characterized, although a strong regulation of the Phe metabolic flux should be expected depending on its alternative use for protein biosynthesis versus phenylpropanoid biosynthesis. This second fate involves a massive carbon flux compared to the first one. Here we report our current research activities in the transcriptional regulation of ADT genes by MYB transcription factors in Pinus pinaster. The conifers channels massive amounts of photosynthetic carbon for phenylpropanoid biosynthesis during wood formation. We have identified the complete ADT gene family in maritime pine (El-Azaz et al., 2016) and a set of ADT isoforms specifically related with the lignification process. The potential control of transcription factors previously reported as key regulators in pine wood formation (Craven-Bartle et al., 2013) will be presented.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Respuesta de hipersensibilidad retardada en pacientes candidatos a artroplastia de cadera

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    Se estudiaron 100 pacientes escogidos de manera aleatoria de entre los candidatos a artroplastia de cadera (47 por fractura subcapital de fémur Garden IV, y 53 por coxartrosis). En el momento del ingresos se determinaron en sangre niveles de albúmina, proteínas totales y hemoglobina; y se midió la respuesta de hipersensibilidad retardada mediante la inoculación de siete antígenos de memoria con un aplicador Multitest® (Mérieux). La lectura de la reacción de induración se realizó a las 48 horas. Los pacientes fueron clasificados en: normoérgicos (+) a dos o más antígenos) y anérgicos (una o ninguna respuesta (+). La población normoérgica representó el 61% de los pacientes, con una edad 12,5 años menor que la población anérgica (p<0,001). Los pacientes normoérgicos presentaron cifras significativamente más altas de hemoglobina (p<0,001), proteínas totales (p<0,05) y albúmina (p<0,001). La situación de anergia fue más frecuente en el grupo de mujeres (29/57) frente al de hombres (10/43; p<0,001), y en el grupo de fracturas subcapitales (31/47) que en el de coxartrosis (8/53) (p<0,001). No se hallaron relaciones estadísticamente significativas entre los distintos parámetros estudiados y la aparición de infección en el postoperatorio. Las diferencias aparecidas reflejan alteraciones en la respuesta inmunológica que, sin embargo, no resultan pronósticas frente a la aparición de infección en nuestra serie.One hundred candidates for hip arthroplasty were chosen at random (47 Garden IV femoral neck fractures, and 53 osteoarthrosis). Before surgery, serum albumin, total proteins and haemoglobin were determined in peripheral blood. All patients were skin tested with seven memory antigens (Multitest®, Mérieux) in order to measure the delayed hypersensitivity response. The diameter of the resulting induration was measured 48 hours after injection. Patients were classified as reactive if they responded to one antigen or showed no response. Reactive patients supposed 61% of total, and anergic patients were 12,5 years older (p<0,001). Levels of haemoglobin (p<0,001), total proteins (p<0,05) and albumin (p<0,001) were higher in reactive patients. Anergy was more frequent in women (29/57) than in men (10/43; p<0,001), and in fractures (31/47) than in osteoarthrosis (8/53) (p<0,001). No association between the variables studied and postoperative infection was found. These differences show immunologic alterations. However, they have no prognostic value for postoperative infection in hip arthroplasty patients

    Characterization and identification of field ectomycorrhizae of Boletus edulis and Cistus ladanifer

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    Field ectomycorrhizae sampled under Boletus edulis and Cistus ladanifer have been characterized and described in detail based on standard morphological and anatomical characters. The described ectomycorrhiza has traits typical of Boletales: whitish with three differentiated plectenchymatous layers in the mantle in plan view forming ring-like structures and rhizomorphs with highly differentiated hyphae. The inflated, smooth cystidia-like clavate end cells on the surface of the rhizomorphs and their slightly twisted external hyphae are additional characterizing features. The Hartig net occupies 1 1/2 rows of cortical cells, partly reaching the endodermis. Not all hyphae have clamps. The identification of the fungal symbiont as B. edulis was confirmed by ITS rDNA sequence comparison between mycorrhizas and sporocarps. The singularity of this symbiotic association, as well as its ecological and practical implications, are discussed

    Ebulitins: A new family of type 1 ribosome-inactivating proteins (rRNA N-glycosidases) from leaves of Sambucus ebulus L. that coexist with the type 2 ribosome-inactivating protein ebulin 1

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    AbstractA new family of single chain (type 1) ribosome-inactivating proteins (RIPs), that we have named ebulitins, have been found in mature leaves of Sambucus ebulus L., a caprifoliaceae plant also known to contain a non-toxic two chain (type 2) RIP named ebulin 1 in its leaves. Ebulitins are basic proteins of Mr 32,000, 29,000 and 29,000 for ebulitins α, β and γ, respectively. The simultaneous presence of different basic type 1 and acidic type 2 RIPs in the same plant and in the same tissue is described here for the first time and opens a new door in research into RIPs

    Methodology to assess the maximum irrigation rates at regional scale using geostatistics and GIS

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    Ponencia presentada en la Conference of Agricultural Engineering celebrada en Valencia del 8 añ 12 de julio de 2012Soil water holding capacity is an important parameter for irrigation scheduling and water balance modelling in fields. In the framework of precision irrigation the knowledge of the spatial distribution of this parameter is useful to advice the maximum irrigation rate specifically for each field in an irrigation district, region, etc. The soil water holding capacity (SWHC) can be assessed as the soil water content between the field capacity (FC) and the permanent wilting point (PWP). In this work, we present a methodology to assess the spatial distribution of the maximum irrigation rate depending on the soil water holding capacity. This methodology combines geostatistic techniques with geographical information system-GIS tool. A pilot zone of 12 400 ha located in the Palancia river lowland (between Valencia and Castellón province, Spain) in which the main irrigated crops are citrus (53.8 %), and vegetables (13.3 %), was selected to develop this methodology. For spatial modelling of SWHC, experimental semivariograms were assessed for the FC and PWP at three soil depth intervals (0-10, 10-30, 30-60 cm). Spherical models fitted well to the experimental semivariograms, with a very high spatial dependency index (ID = 0.05-0.41) which support reliable predictions on basis the fitted models. The cokriging spatial interpolation method, considering the percentage of sand as secondary variable, was the best option to minimize the root mean square error in the cross-validation test.Peer Reviewe

    On the exciton model for ion-beam damage: The example of TiO2

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    The non-radiative exciton decay model recently developed to account for swift-ion-beam damage to LiNbO3 is, here, discussed within a general physical perspective, taking previous work on alkali halides as a reference. Some general rules for the validity of excitonic models have been put forward, allowing one to predict the irradiation behaviour of other materials. As a new example of application, some preliminary data on the generation and growth of uniform amorphous layers induced by irradiation with Br at 13 MeV and 25 MeV have been performed on rutile (TiO2). In addition sub-threshold irradiations with Br ions at 9 MeV have been carried out. Defects generation is observed as a result. This effect is explained with the exciton model. Experiments are in the electronic excitation regime and use moderate fluences in the range of 6 × 1012 to 1.5 × 1014 cm−2. The results show similar features to those found for LiNbO3 and are, in principle, consistent with a non-radiative exciton decay model

    Comparative study of ion beam-irradiation effects on silica and α-quartz: evidences for excitonic mechanisms

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    Introduction - SiO 2 •Simple composition and structure; Crystalline and amorphous phases •Adequate for atomistic simulations •Abundant in nature. Relevant for many technologies -Irradiation with swift heavy ions: •They provide EXTREME physical conditions •Very high excitation densities similar to high power lasers •Very high local temperatures •By playing with high energy and heavy mass (SHI) : •One can go from low electronic excitations (collisions regime) to high electronic excitations (electronic regim

    Greater dietary variety is associated with better biochemical nutritional status in Spanish children: the Four Provinces Study

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    BACKGROUND AND AIM: Although dietary variety has been associated with a better nutritional profile, its possible role in obesity raises doubts about its overall health benefits. In this study, we examined the association between dietary variety and anthropometric variables, food intake and various food intake biomarkers in Spanish children. METHODS AND RESULTS: This was a cross-sectional study of 1112 children aged 6-7 years from Cadiz, Murcia, Orense and Madrid, who were selected by means of the random cluster-sampling of schools. Information concerning food and nutrient intake was obtained using a food frequency questionnaire, and a dietary variety index (DVI) was calculated on the basis of the number of different foods consumed more than once a month. The anthropometric variables (weight and height), and plasma lipid and vitamin levels were determined using standardised methods. Our results show that the body mass index (BMI) did not vary substantially as a function of DVI: it was 16.9 in the lowest DVI tertile and 17.2 in the highest (p=0.20). Unlike BMI, the DVI positively correlated (p<0.05) with the plasma levels of alpha and beta-carotene, lycopene, retinol, alpha-tocopherol and vitamin E, with energy intake, and with most of the foods, particularly vegetables, fruit and sausages (respective correlation coefficients of 0.43, 0.26 and 0.23). CONCLUSIONS: Dietary variety is associated with a better food and nutritional profile in Spanish children. Nevertheless, the presence of a positive association between the DVI and energy intake, and the consumption of sausages and pre-cooked products calls for the recommendation of a varied diet of healthy foods, such as cereals (especially whole grains), fruits and vegetables

    Theoretical study of the conformational energy hypersurface of cyclotrisarcosyl

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    The multidimensional Conformational Potential Energy Hypersurface (PEHS) of cyclotrisarcosyl was comprehensively investigated at the DFT (B3LYP/6-31G(d), B3LYP/6-31G(d,p) and B3LYP/6-311++G(d,p)), levels of theory. The equilibrium structures, their relative stability, and the Transition State (TS) structures involved in the conformational interconversion pathways were analyzed. Aug-cc-pVTZ//B3LYP/6-311++G(d,p) and MP2/6-31G(d)//B3LYP/6-311++G(d,p) single point calculations predict a symmetric cis-cis-cis crown conformation as the energetically preferred form for this compound, which is in agreement with the experimental data. The conformational interconversion between the global minimum and the twist form requires 20.88 kcal mol-1 at the MP2/6-31G(d)//B3LYP/6- 311++G(d,p) level of theory. Our results allow us to form a concise idea about the internal intricacies of the PEHSs of this cyclic tripeptide, describing the conformations as well as the conformational interconversion processes in this hypersurface. In addition, a comparative analysis between the conformational behaviors of cyclotrisarcosyl with that previously reported for cyclotriglycine was carried out.Fil: Alvarez, Maria de Los Angeles. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química; ArgentinaFil: Saavedra, Edgardo J.. Universidad Nacional de la Patagonia "San Juan Bosco"; ArgentinaFil: Olivella, Mónica Susana. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química; ArgentinaFil: Suvire, Fernando Daniel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química; ArgentinaFil: Zamora, Miguel Angel. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química; ArgentinaFil: Enriz, Ricardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto Multidisciplinario de Investigaciones Biológicas de San Luis; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química; Argentin

    Production and purification of immunologically active core protein p24 from HIV-1 fused to ricin toxin B subunit in E. coli

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    <p>Abstract</p> <p>Background</p> <p>Gag protein from HIV-1 is a polyprotein of 55 kDa, which, during viral maturation, is cleaved to release matrix p17, core p24 and nucleocapsid proteins. The p24 antigen contains epitopes that prime helper CD4 T-cells, which have been demonstrated to be protective and it can elicit lymphocyte proliferation. Thus, p24 is likely to be an integral part of any multicomponent HIV vaccine. The availability of an optimal adjuvant and carrier to enhance antiviral responses may accelerate the development of a vaccine candidate against HIV. The aim of this study was to investigate the adjuvant-carrier properties of the B ricin subunit (RTB) when fused to p24.</p> <p>Results</p> <p>A fusion between ricin toxin B subunit and p24 HIV (RTB/p24) was expressed in <it>E. coli</it>. Affinity chromatography was used for purification of p24 alone and RTB/p24 from cytosolic fractions. Biological activity of RTB/p24 was determined by ELISA and affinity chromatography using the artificial receptor glycoprotein asialofetuin. Both assays have demonstrated that RTB/p24 is able to interact with complex sugars, suggesting that the chimeric protein retains lectin activity. Also, RTB/p24 was demonstrated to be immunologically active in mice. Two weeks after intraperitoneal inoculation with RTB/p24 without an adjuvant, a strong anti-p24 immune response was detected. The levels of the antibodies were comparable to those found in mice immunized with p24 alone in the presence of Freund adjuvant. RTB/p24 inoculated intranasally in mice, also elicited significant immune responses to p24, although the response was not as strong as that obtained in mice immunized with p24 in the presence of the mucosal adjuvant cholera toxin.</p> <p>Conclusion</p> <p>In this work, we report the expression in <it>E. coli </it>of HIV-1 p24 fused to the subunit B of ricin toxin. The high levels of antibodies obtained after intranasal and intraperitoneal immunization of mice demonstrate the adjuvant-carrier properties of RTB when conjugated to an HIV structural protein. This is the first report in which a eukaryotic toxin produced in <it>E. coli </it>is employed as an adjuvant to elicit immune responses to p24 HIV core antigen.</p
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