Differential activities of glutathione s-transferase isoenzymes in strains of fasciola hepatica susceptible and resistant to triclabendazole

Fasciolosis, a parasitic zoonosis of intrahepatic location, is caused by the trematode Fasciola hepatica. Its control is mainly based on the use of the anthelminthic Triclabendazole (TCBZ). The indiscriminate use of this drug has favored the development of anthelmintic resistance. The Glutation S-Transferases (GSTs) are multifunctional enzymes involved in the detoxification of xenobiotics and endogenous compounds using conjugation with endogenous glutathione. Recently, it has been shown an active participation of this family of enzymes in the detoxification of TCBZ related to the phenomenon of resistance. In F. hepatica, eight isoenzymes of the GST are present. Since it is well known that different isoenzymes do not necessarily have the same metabolic activity, this study evaluated the cytosolic activity of mu and pi GST isoenzymes in TCBZ resistant (Sligo and Oberon strains) and TCBZ susceptible (Cullompton strains) of F. hepatica. The results obtained in this study confirm that, although both isoenzymes are involved in different processes of detoxification in F. hepatica, only the GSTmu isoenzyme is involved in the manifestation of resistance to TCBZ.Fil: Fernandez, Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Ortiz Oblitas P.. Universidad Nacional de Cajamarca; PerúFil: Solana, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; Argentina. Ministerio de Ciencia. Tecnología e Innovación Productiva. Agencia Nacional de Promoción Cientifíca y Tecnológica; ArgentinaFil: Solana, Hugo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; Argentin

Increase of gluthatione S-transferase, carboxyl esterase and carbonyl reductase in Fasciola hepatica recovered from triclabendazole treated sheep

Fasciolasis is a zoonotic parasitic disease caused by Fasciola hepatica and its control is mainly based on the use of triclabendazole (TCBZ). Parasite resistance to different anthelmintics is growing worldwide, including the resistance of F. hepatica to TCBZ. In the present work we evaluate “in vivo” the activity of xenobiotic metabolizing enzymes of phase I (carboxyl esterases) and phase II (glutathione S-transferases and carbonyl reductases) recovered of flukes from sheep treated with TCBZ. All three enzymes showed increased activity in TCBZ flukes returning 60 h post-treatment at similar to baseline unexposed flukes. TCBZ action may induce secondary oxidative stress, which may explain the observed increment in activities of the analyzed enzymes as a defensive mechanism. The enzymes analyzed are candidates to participate actively in the development of resistance at TCBZ in F. hepatica.Fil: Scarcella, Silvana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; ArgentinaFil: Solana, M. V.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; ArgentinaFil: Fernandez, Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; ArgentinaFil: Lamenza, Pamela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; ArgentinaFil: Ceballos, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; ArgentinaFil: Solana, Hugo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Centro de Investigacion Veterinaria de Tandil; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentin

A multienzyme response is involved in the phenomenon of resistance to triclabendazole on Fasciola

The trematode Fasciola hepatica is the producer of a parasitic zoonosis known as fasciolosis. Triclabendazole (TCBZ) is the most widely used fasciolicide anthelmintic. Today, its indiscriminate use has led to the expression of anthelmintic resistance. Our previous studies over the Sligo strain (TCBZ-R) confirmed in the Phase I of detoxification, an overexpression of Flavin-Monooxygenases. This phenomenon should not be the only response that the trematode has and should not rule out the involvement of other processes of detoxification of Phase I or II. In the processes of detoxification in Phase I, the Carboxylesterase (CE) is a serine esterase-dependent with broad substrate specificity. This family of enzymes are involved in many metabolic functions including detoxification of xenobiotics. In Phase II exists a system using the Glutathione (GSH). It is a sequence of certain enzymes that culminate adding reduced GSH to xenobiotic increasing its water solubility and facilitatingtheir excretion. Glutathione addition plays an important role in antioxidant defense in different tissues catalyze the reduction of oxidized to reduced GSH which will be utilized by GST to reduce the peroxide and lipoperoxide, which they are reactive oxygen species. This process involves Glutathione Peroxidase (GPx), Glutathione Reductase (GSR) and Glutathione S-Transferase (GST). In the present work, we evaluate, in vitro, the cytosolic activity of different xenobiotic metabolizing enzymes of Phase I: CE and Phase II: GST, GPx and GSR in adults of F. hepatica TCBZ susceptible (TCBZ-S) and TCBZ resistant (TCBZ-R),respectively Cullompton strain and Sligo and Oberon strains. In the TCBZ-R Sligo and Oberon strains, the GST activity was 1277±32 and 1216±16 nmol/min/mg protein, respectively, higher than that in the TCBZ-S Cullompton strain 800±60 nmol/ min/mg protein. Regarding the GPx activity in the Sligo and Oberon strains, TCBZ-R was 83±3.41 and 81±2.45 nmol/min/ mg protein, respectively, higher than that in the TCBZ-S Cullompton strain 49±2.58 nmol/min/mg protein. The GSR activity in Sligo and Oberon strains was 38±2.07 and 41±1.25 nmol/min/mg protein, respectively, higher than that in the TCBZ-S Cullompton strain 29±1.22 nmol/min/mg protein, whereas CE activity did not differ between the different strains tested. In this work, a multienzyme response involving at all the family of enzymes GSH dependent is detected. Carboxylesterase expressed no significant differences not being involved in the resistance phenomenon. These results contribute to the understanding of the mechanisms referred to the phenomenon of resistance to TCBZ.Fil: Fernandez, Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Acevedo, Maria E.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Laboratorio de Biología Celular y Molecular; ArgentinaFil: Solana, Hugo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; Argentina. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias. Laboratorio de Biología Celular y Molecular; ArgentinaInternational Conference on ParasitologyPhiladelphiaEstados UnidosOMICS Publishing Grou

Comparative genetic analysis of glutathione S-transferase Fasciola hepatica from different definitive hosts

La fasciolosis, parasitosis zoonótica de ubicación intrahepática, es ocasionada por Fasciola hepatica. La resistencia de F. hepatica a TCBZ está progresando mundialmente por lo cual es necesario ampliar el conocimiento sobre los mecanismos de detoxificación que este helminto posee. Las glutatión S-transferasas (GSTs), enzimas multifuncionales implicadas en la detoxificación de compuestos endógenos y xenobióticos, podrían participar en la expresión de resistencia al TCBZ. En este trabajo se determinó el nivel de expresión del ARNm y se caracterizó el gen para GST (genGST) correspondiente a fasciolas provenientes de tres hospedadores diferentes infectados naturalmente. Las secuencias del genGST de las fasciolas analizadas se compararon con las secuencias de las cepas Sligo (triclabendazol resistente: TCBZ-R) y Cullompton (triclabendazol sensible: TCBZ-S) (GenBank ID: KF680281- KF680284, respectivamente) obtenidas en nuestro laboratorio. Las fasciolas de las tres especies hospedadoras expresaron diferencias significativas en el ARNm: cerdo 2> bovino 1.7> ovino 1 y un genGST idéntico al de la cepa TCBZ-S. La diferencia de expresión podría relacionarse con el nivel de resistencia de los diferentes huéspedes a F. hepatica. Estos resultados aportarían a la comprensión de los mecanismos generadores de resistencia a F. hepatica en los distintos huéspedes definitivos.Fasciolosis, a zoonotic intrahepatic parasitosisis caused by Fasciola hepatica. Resistance of F. hepatica to TCBZ is progressing globally so it is necessary to increase the knowledge of the mechanisms of detoxification that this helminth possesses. The multifunctional enzymes glutathione S- transferases (GSTs) are involved in the detoxification of endogenous and xenobiotic compounds and could be involved in the expression of resistance to TCBZ. In this work the level of mRNA expression was determined and the gene for GST (genGST) from flukes from three different naturally infected hosts was characterized. The sequence of the genGST was compared with the sequences of resistant (TCBZ-R) (Sligo) and sensible (TCBZ-S) (Cullompton) strains of F. hepatica (GenBank ID: KF680281 - KF680284, respectively) obtained in our laboratory. Flukes of three different hosts expressed significant differences in their mRNA: porcine 2> bovine 1.7 > ovine 1 and the genGST sequence was identicalto TCBZ-S strain of F. hepatica. The difference in expression of the genGST could be related to the level of resistance of the different hosts against F. hepatica. These results would contribute to the understanding of the mechanisms of resistance to F. hepatica in different definitive hosts.Fil: Fernandez, Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Estein, Silvia Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; ArgentinaFil: Ortiz, Pedro. Universidad Nacional de Cajamarca; PerúFil: Solana, Hugo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigación Veterinaria de Tandil. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigación Veterinaria de Tandil. Provincia de Buenos Aires. Gobernación. Comision de Investigaciones Científicas. Centro de Investigación Veterinaria de Tandil; Argentin

Hydroxyl identification on ZnO by infrared spectroscopies: theory and experiment

Herein, we present a thorough density functional study combining experiments on ZnO nanostructures aimed at the identification, by means of infrared (IR) spectroscopies, of hydroxyl and hydride species formed on the most stable low-index Miller surfaces of wurtzite ZnO, namely, the Zn- and O-terminated (0001) and (000 (1) over bar) polar surfaces and the nonpolar (10 (1) over bar0) and (11 (2) over bar0) surfaces. The Perdew-Burke-Ernzerhof functional was employed in periodic slab calculations, all possible H and OH adsorption modes were studied at medium and full coverages, and IR spectra were simulated for the most favorable situations. This information was used to model the most likely surface arrangements upon exposure to either H-2 or H2O. IR experiments on ZnO surfaces and nanoparticles are discussed based on the calculated adsorption energy values and simulated IR spectra. This study emphasizes the detailed assignment of OH moieties with the help of IR spectra and their interpretation as fingerprints of surface morphology, allowing for a consistent interpretation of the stability of water adlayers and their corresponding vibrational fingerprints as a function of coverage, low-index Miller surface, and hydrogen source

Understanding W doping in wurtzite ZnO

In the context of bandgap engineering of the ZnO photoactive material for solar harvesting applications via W doping, a number of a priori discrepant experimental observations in the literature concerning ZnO c axis expansion/contraction, bandgap red- or blue-shifting, the Zn-substitutional or interstitial nature of W atoms, or the W6+ charge compensation view with ZnO native defects are addressed by thorough density functional theory calculations on a series of bulk supercell models encompassing a large range of W contents. The present results reconcile the at first sight dissimilar observations by showing that interstitial W (Wi) is only energetically preferred over substitutional (WZn) at large large W doping concentrations; the WZn c lattice expansion can be compensated by a W triggered Zn-vacancy (VZn) c lattice contraction. The presence of WZn energetically fosters nearby VZn defects, and vice versa, up to a double VZn situation. The quantity of mono or divacancies explains the lattice contraction/expansion, and both limiting situations imply gap states which reduce the band gaps, but increase the energy gaps. Based on present results, the ZnO band gap red-shifting necessary for solar light triggered processes is achievable by W doping in Zn rich conditions

Knowledge pipeline in freight pipeline industry: competence- based model for open innovation

There is growing concern over the challenges for innovation in Freight Pipeline industry. Since the early works of Chesbrough a decade ago, we have learned a lot about the content, context and process of open innovation. However, much more research is needed in Freight Pipeline Industry. The reality is that few corporations have institutionalized open innovation practices in ways that have enabled substantial growth or industry leadership. Based on this, we pursue the following question: How does a firm’s integration into knowledge networks depend on its ability to manage knowledge? A competence-based model for freight pipeline organizations is analysed, this model should be understood by any organization in order to be successful in motivating professionals who carry out innovations and play a main role in collaborative knowledge creation processes. This paper aims to explain how can open innovation achieve its potential in most Freight Pipeline Industries

Real-time moving object segmentation in H.264 compressed domain based on approximate reasoning

AbstractThis paper presents a real-time segmentation algorithm to obtain moving objects from the H.264 compressed domain. The proposed segmentation works with very little information and is based on two features of the H.264 compressed video: motion vectors associated to the macroblocks and decision modes. The algorithm uses fuzzy logic and allows to describe position, velocity and size of the detected regions in a comprehensive way, so the proposed approach works with low level information but manages highly comprehensive linguistic concepts. The performance of the algorithm is improved using dynamic design of fuzzy sets that avoids merge and split problems. Experimental results for several traffic scenes demonstrate the real-time performance and the encouraging results in diverse situations

Morphology effects in photoactive ZnO nanostructures: photooxidative activity of polar surfaces

A series of ZnO nanostructures with variable morphology were prepared by a microemulsion method and their structural, morphological, and electronic properties were investigated by a combined experimental and theoretical approach using microscopy (high resolution transmission electron microscopy) and spectroscopic (X-ray diffraction, Raman, and UV-visible) tools, together with density functional theory calculations. The present experimental and computational study provides a detailed insight into the relationship between surface-related physicochemical properties and the photochemical response of ZnO nanostructures. Specifically, the present results provide evidence that the light-triggered photochemical activity of ZnO nanostructures is related to the predominance of highly-active (polar) surfaces, in particular, the amount of Zn-terminated (0001) surfaces, rather than band gap sizes, carrier mobilities, and other variables usually mentioned in the literature. The computational results highlight the oxidative capability of polar surfaces, independently of the degree of hydration

Automatic segmentation of rivers as a tool for assessing river responses. Case study: the Porma and Curueño rivers, nw Spain.

Automatic segmentation using univariate and multivariate techniques provides more objective and efficient segmentations of the river systems (Alber & Piégay, 2011) and can be complementary to the expert criteria traditionally used (Brenden et al., 2008) INTEREST: A powerful tool to objectively segment the continuity of rivers, which is required for diagnosing problems associated to human impacts OBJECTIVE: To evaluate the potentiality of univariate and multivariate methods in the assessment of river adjustments produced by flow regulatio