38 results on '"Barrientos V"'
Search Results
2. Efecto del toltrazuril y la combinación de sulfadoxina y pirimetamina en el tratamiento de la sarcocistiosis canina durante el período patente
- Author
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Barrientos V., María, Chávez V., Amanda, Pacheco P., Atilio, Ticona S., Daniel, and Leyva V., Víctor
- Published
- 2007
3. Geochemical assessment of the contaminant potential of granite fines produced during sawing and related processes associated to the dimension stone industry
- Author
-
Delgado, J., Vázquez, A., Juncosa, R., and Barrientos, V.
- Published
- 2006
- Full Text
- View/download PDF
4. Assessment of the effect of testosterone on the acrosome reaction of human spermatozoa
- Author
-
Vigil, P., Barrientos, V. M., Vargas, G. G., Machuca, D. A., and Cortés, M. E.
- Published
- 2012
- Full Text
- View/download PDF
5. Hydrodynamic and reactive transport modeling of the behavior of compacted granite saw dust for landfill liners and covers
- Author
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Navarro, V, primary, Barrientos, V, additional, Juncosa, R, additional, Falcón, I, additional, Vázquez, A, additional, and Delgado, J, additional
- Published
- 2007
- Full Text
- View/download PDF
6. Effect of supercritical CO2 on the Corvio sandstone in a flow-thru triaxial experiment
- Author
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Canal, J., Jordi Delgado Martin, Barrientos, V., Juncosa, R., Rodríguez-Cedrún, B., and Falcón-Suarez, I.
- Published
- 2014
7. Estudio de la Expresión de los Receptores de Progesterona y Estrógeno en el Endometrio de Ovejas Alimentadas con Dieta Normal y Dieta Suplementada
- Author
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Vasconcellos C, Adriana, Paredes H, Marco, Núñez R, Daniela, Barrientos V, Eduardo, Olmazábal S, Yoselyn, and V, Javiera
- Subjects
Alimentación de ovejas ,Reproductive system ,Sheep food ,Sistema reproductor ,Oveja criolla Araucana - Abstract
La influencia de la nutrición sobre la reproducción en ovinos es compleja y los resultados observados son variables. Planes nutricionales bajos pueden ser causa de una reducción de la sensibilidad del endometrio a la progesterona lo que afecta el desarrollo morfofuncional del endometrio en estadios tempranos de la preñez y por lo tanto va en directo detrimento de la sobrevida del embrión. La progesterona y los estrógenos actúan a través de receptores intracelulares específicos que median su efecto fisiológico. Por lo tanto el nivel de expresión de estos receptores es fundamental para el efecto hormonal. El objetivo del presente estudio fue analizar en forma conjunta la expresión de receptores de progesterona (RP) y estrógeno (RE), en el endometrio de ovejas en ciclo alimentadas con dieta suplementada y dieta normal. La expresión de la proteína receptora como del transcrito de ambos receptores se detectó mediante análisis inmunohistoquímico y RT-PCR en Tiempo Real. Los resultados muestran expresión inmunohistoquímica contra ambos receptores en zonas glándulares y carunculares, destacándose una intensa inmunorreacción en núcleo de células estromales y del epitelio glandular. Se detectó mayor expresión del transcrito de ambos receptores en ovejas alimentadas con suplemento respecto a las que no recibieron suplemento alimenticio. The influence of nutrition on reproduction in sheep is complex and the reported results are variable. Low nutritional programs can cause a reduction in the sensitivity of the endometrium to progesterone which affects morphofunctional development of the endometrium in early stages of pregnancy and therefore is in direct expense of the survival of the embryo. Progesterone and estrogens act through specific intracellular receptors that mediate its physiological effect. Therefore the level of expression of these receptors is essential for the hormonal effect. The aim of this study was to analyze the expression of progesterone receptors (PR) and estrogen (ER) in the endometrium of sheep supplemented diet cycle and fed normal diet. The expression of the receptor protein and the transcript of both receptors was detected by immunohistochemistry and RT-PCR Real Time. The results show immunohistochemical expression against both receptors in caruncular and glandular areas, highlighting an intense immunoreaction in the nucleus of stromal cells and glandular epithelium. Were detected increased expression of the transcript of both receptors in sheep fed on the supplement that did not receive food supplement. We discuss the possible use of this information for applications in breeding programs in sheep breeding.
- Published
- 2010
8. Estudio de la Expresión de los Receptores de Progesterona y Estrógeno en el Endometrio de Ovejas Alimentadas con Dieta Normal y Dieta Suplementada
- Author
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Daniela Núñez R, Javiera V, Adriana Vasconcellos C, Eduardo Barrientos V, Marco Paredes H, and Yoselyn Olmazábal S
- Subjects
Alimentación de ovejas ,Nutritional status ,Anatomy ,Biology ,Sistema reproductor ,Humanities ,Oveja criolla Araucana - Abstract
La influencia de la nutrición sobre la reproducción en ovinos es compleja y los resultados observados son variables. Planes nutricionales bajos pueden ser causa de una reducción de la sensibilidad del endometrio a la progesterona lo que afecta el desarrollo morfofuncional del endometrio en estadios tempranos de la preñez y por lo tanto va en directo detrimento de la sobrevida del embrión. La progesterona y los estrógenos actúan a través de receptores intracelulares específicos que median su efecto fisiológico. Por lo tanto el nivel de expresión de estos receptores es fundamental para el efecto hormonal. El objetivo del presente estudio fue analizar en forma conjunta la expresión de receptores de progesterona (RP) y estrógeno (RE), en el endometrio de ovejas en ciclo alimentadas con dieta suplementada y dieta normal. La expresión de la proteína receptora como del transcrito de ambos receptores se detectó mediante análisis inmunohistoquímico y RT-PCR en Tiempo Real. Los resultados muestran expresión inmunohistoquímica contra ambos receptores en zonas glándulares y carunculares, destacándose una intensa inmunorreacción en núcleo de células estromales y del epitelio glandular. Se detectó mayor expresión del transcrito de ambos receptores en ovejas alimentadas con suplemento respecto a las que no recibieron suplemento alimenticio.
- Published
- 2010
9. Análisis de la Expresión del Receptor del Estrógeno en Endometrio de Ovejas Alimentadas con Dieta Normal y Dieta Suplementada
- Author
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Adriana Vasconcellos C, Benedicto Molina E, Yoselyn Olmazábal S, Marco Paredes H, Eduardo Barrientos V, Javiera Navarrete, and Daniela Núñez R
- Subjects
Oveja ,Receptor de estrógeno ,Endometrio ,Nutrición ,Receptor de progesterona ,Anatomy - Abstract
Los efectos de la nutrición en reproducción ovina han sido estudiados por numerosos autores. Principalmente, el interés se ha centrado en los efectos de la calidad de la dieta ya que en ovinos sometidos a planos nutricionales bajos se ha observado anormalidades del embrión, fase lutea inadecuada, deficiencia en el aporte de progesterona al útero y falla en los mecanismos que comprenden el reconocimiento materno a la preñez. Existen trabajos sobre la relación alimentación-hormonas sin embargo la información existente sobre los receptores de hormonas esteroidales endometriales, indispensables para que ellas actúen, es muy escasa. El objetivo del presente estudio fue analizar comparativamente la expresión del receptor de estrógenos (RE) en el endometrio de ovejas en ciclo alimentadas con dieta suplementada y dieta normal. La expresión de la proteína receptora y del transcrito se detectó mediante análisis inmunohistoquímico y RT-PCR en tiempo real respectivamente. Los resultados muestran expresión inmunohistoquímica en zonas glandulares y carunculares, destacándose una intensa inmunorreacción en núcleos de células estromales y del epitelio glandular. Se detecto mayor expresión del transcrito del RE en endometrio de ovejas alimentadas con suplemento respecto a las que no recibieron suplemento alimenticio. Se discute el posible uso de esta información para aplicarla en programas de mejoramiento reproductivo en ovinos.
- Published
- 2009
10. Análisis de la Expresión del Receptor del Estrógeno en Endometrio de Ovejas Alimentadas con Dieta Normal y Dieta Suplementada
- Author
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Vasconcellos C, Adriana, Paredes H, Marco, Barrientos V, Eduardo, Olmazábal S, Yoselyn, Núñez R, Daniela, Navarrete V, Javiera, and Molina E, Benedicto
- Subjects
Oveja ,Sheep ,Receptor de estrógeno ,Endometrio ,Nutrición ,Receptor de progesterona ,Estrogen receptor ,Endometrial ,Progesterone receptor ,Nutrition - Abstract
Los efectos de la nutrición en reproducción ovina han sido estudiados por numerosos autores. Principalmente, el interés se ha centrado en los efectos de la calidad de la dieta ya que en ovinos sometidos a planos nutricionales bajos se ha observado anormalidades del embrión, fase lutea inadecuada, deficiencia en el aporte de progesterona al útero y falla en los mecanismos que comprenden el reconocimiento materno a la preñez. Existen trabajos sobre la relación alimentación-hormonas sin embargo la información existente sobre los receptores de hormonas esteroidales endometriales, indispensables para que ellas actúen, es muy escasa. El objetivo del presente estudio fue analizar comparativamente la expresión del receptor de estrógenos (RE) en el endometrio de ovejas en ciclo alimentadas con dieta suplementada y dieta normal. La expresión de la proteína receptora y del transcrito se detectó mediante análisis inmunohistoquímico y RT-PCR en tiempo real respectivamente. Los resultados muestran expresión inmunohistoquímica en zonas glandulares y carunculares, destacándose una intensa inmunorreacción en núcleos de células estromales y del epitelio glandular. Se detecto mayor expresión del transcrito del RE en endometrio de ovejas alimentadas con suplemento respecto a las que no recibieron suplemento alimenticio. Se discute el posible uso de esta información para aplicarla en programas de mejoramiento reproductivo en ovinos. The effects of nutrition on sheep reproduction have been studied by many authors. The interest has focused on the effects of diet quality in sheepin in which low plans n have low plane nutrition can cause abnormalities of the ovum or the embryo, luteal inadequancy and failure of the supply of progesterone to the uterus or failurein the mechanisms involved maternal of pregnancy. There are papers about the relation food-hormones, however, the existing information on endometrial steroid hormone receptors, which are essential for them to act, is very scarce. The aim of this study was to comparatively analyze the expression of estrogen receptor (ER) in endometrial cycle of sheep fed diet supplemented and normal diet. The expression of the receptor protein and the transcript were detected by immunohistochemical analysis and RT real-time PCR, respectively. The results showed immunohistochemical expression of RE in glandular and carunculares areas, especially in an intense inmunorreacción stromal cell nuclei and glandular epithelium. Detected increased expression of transcripts of RE in sheep fed a supplement with respect to not receiving a dietary supplement. We discuss the possible use of this information for application in breeding sheeps programs.
- Published
- 2009
11. EFECTO DEL TOLTRAZURIL Y LA COMBINACIÓN DE SULFADOXINA Y PIRIMETAMINA EN EL TRATAMIENTO DE LA SARCOCISTIOSIS CANINA DURANTE EL PERIODO PATENTE
- Author
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María Barrientos V., Daniel Ticona S., Amanda Chávez V., Atilio Pacheco P., and Víctor Leyva V.
- Subjects
sulfadoxine ,efectividad ,pirimetamina ,General Veterinary ,sarcocistiosis ,sulfadoxina ,Toltrazuril ,effectiveness ,sarcosystiosis ,pirimetamine - Abstract
El objetivo del estudio fue evaluar la eficacia del toltrazuril (2.5%) y de la combinación de sulfadoxina y pirimetamina (500/25 mg) en el tratamiento de la sarcocistiosis canina. El estudio se realizó durante los meses de octubre del 2005 a marzo del 2006, en la Estación Experimental del Centro de Investigaciones IVITA, Maranganí, Cusco, perteneciente a la Facultad de Medicina Veterinaria, UNMSM. Se utilizó 15 cachorros cruzados de ambos sexos, de 2-3 meses de edad, previamente desparasitados y alimentados solo con concentrado. Todos ellos fueron infectados con aproximadamente 9,000-10,000 quistes de Sarcocystis lamacanis, presentes en 4-5 g de tejido cardiaco de alpaca. Las heces se analizaron diariamente hasta observar la presencia de esporoquistes u ooquistes de Sarcocystis sp. Posteriormente fueron distribuidos en tres grupos de 5 animales c/u. Un grupo control no tratado y dos grupos tratados diariamente por 10 días, uno con toltrazuril (2.5%) en dosis de 15 mg/kpv y otro grupo con la combinación de sulfadoxina y pirimetamina (500/25 mg) en dosis de 20 y 1 mg/kgpv, respectivamente. Muestras fecales fueron recolectadas diariamente y se analizaron por el método de coproparasitologico de flotación con solución de Sheather para determinar la presencia de ooquistes o esporoquistes de Sarcocystis sp., y las muestras positivas se cuantificaron por el método de Stoll modificado, para determinar su número por gramo de heces. Los resultados muestran que el toltrazuril alcanzó una eficacia en el control de la sarcocistiosis del 94.7 % al tercer día de tratamiento y un 100% al sexto día, mientras que la combinación de sulfadoxina y pirimetamina no logró controlarla, llegando a mostrar una moderada eficacia al segundo día post tratamiento (88.1%)., The objective of this study was to evaluate the efficacy of toltrazuril (2.5)% and the combination of sulfadoxine and pirimetamine (500-25 mg) on the treatment of canine sarcocystiosis. The study was conducted from October 2005 until March 2006 in the Experimental Station of the IVITA Research Center, Maranganí, Cusco. A total of 15 crossbred puppies, both sexes, 2-4 months of age, that were dewormed and fed with a diet extent of meat were used. Puppies were infected with approximately 9,000- 10,000 cysts of Sarcosystis lamacanis present in 4-5 g of alpaca heart. Feces were daily collected and analyzed to observe the presence of sporocysts or oocysts. Then, were distributed in three groups of 5 animals each. One group remained untreated (as control) and the other two groups were daily treated during 10 days with 15 mg/kg of toltrazuril (2.5%) or the combination of sulfadoxine and pirimetamine (500-25 mg) in a dose of 20 and 1 mg/kg respectively. Fecal samples were daily collected and analyzed by the flotation method using the Sheather solution to determine the presence of sporocysts or oocysts and the modified Stoll method to quantify the number of eggs per gram of feces. The results showed that the efficacy of toltrazuril in the control of sarcosystiosis was 94.7% at the 3rd day of treatment and 100% at day 6, whereas the combination of sulfadoxine and pirimetamine did not control it, and only a moderate efficacy (88.1%) was observed in the 2nd day.
- Published
- 2007
12. Injection of CO2-saturated water through a siliceous sandstone plug from the Hontomin Test Site (Spain): experiment and modeling
- Author
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Canal, J., Delgado, J., Falcon, I., Yang, Q., Juncosa, R., Barrientos, V., Canal, J., Delgado, J., Falcon, I., Yang, Q., Juncosa, R., and Barrientos, V.
- Abstract
Massive chemical reactions are not expected when injecting CO2 in siliceous sandstone reservoirs, but their performance can be challenged by small-scale reactions and other processes affecting their transport properties. We have conducted a core flooding test with a quartzarenite plug of Lower Cretaceous age representative of the secondary reservoir of the Hontomín test site. The sample, confined at high pressure, was successively injected with DIW and CO2-saturated DIW for 49 days while monitoring geophysical, chemical, and hydrodynamic parameters. The plug experienced little change, without evidence of secondary carbonation. However, permeability increased by a factor of 4 (0.022–0.085 mD), and the VP/VS ratio, whose change is related with microcracking, rose from ?1.68 to ?1.8. Porosity also increased (7.33–8.1%) from the beginning to the end of the experiment. Fluid/rock reactions were modeled with PHREEQC-2, and they are dominated by the dissolution of Mg-calcite. Mass balances show that ?4% of the initial carbonate was consumed. The results suggest that mineral dissolution and microcracking may have acted in a synergistic way at the beginning of the acidic flooding. However, dissolution processes concentrated in pore throats can better explain the permeability enhancement observed over longer periods of time.
- Published
- 2013
13. Characterization and geochemical-geotechnical properties of granite sawdust produced by the dimension stone industry of O Porrino (Pontevedra, Spain)
- Author
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Barrientos, V., Delgado, J., Navarro, V., Juncosa, R., Falcon, I., Vazquez, A., Barrientos, V., Delgado, J., Navarro, V., Juncosa, R., Falcon, I., and Vazquez, A.
- Abstract
The dimension stone industry is one of the leading economic activities of Galicia and it is also an important industry in many other parts in the world. During the sawing and preparation of dimension stone, a large amount of granite sawdust is generated. In the O Porriño area alone, located in the southern part of Galicia, c.?300 000 tonnes are produced every year. According to current EU Directives, granite sawdust is considered to be waste and its disposal must conform to the environmental standards that result from their implementation. The pertinent Spanish laws have established the need to lay down a suitable strategy for the characterization and assessment of sawdust products for the purpose of their satisfactory integration into the dimension stone productive chain. This paper presents the results of a comprehensive characterization study of the granite sawdust of O Porriño (Pontevedra, NW Spain), including a description of its physicochemical, mineralogical and geotechnical properties. On the basis of the results of this characterization, we raise the question of the suitability of this material for use in earthworks as well as in the construction of layers for landfill sealing and/or waterproofing. Our findings show that the properties of granite sawdust are suitable for such purposes, and other possible uses are being studied in continuing research.
- Published
- 2010
14. Injection of CO2-Saturated Water through a Siliceous Sandstone Plug from the Hontomin Test Site (Spain): Experiment and Modeling
- Author
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Canal, J., primary, Delgado, J., additional, Falcón, I., additional, Yang, Q., additional, Juncosa, R., additional, and Barrientos, V., additional
- Published
- 2012
- Full Text
- View/download PDF
15. EFECTO DEL TOLTRAZURIL Y LA COMBINACIÓN DE SULFADOXINA Y PIRIMETAMINA EN EL TRATAMIENTO DE LA SARCOCISTIOSIS CANINA DURANTE EL PERIODO PATENTE.
- Author
-
Barrientos V., María, primary, Chávez V., Amanda, additional, Pacheco P., Atilio, additional, Ticona S., Daniel, additional, and Leyva V., Víctor, additional
- Published
- 2012
- Full Text
- View/download PDF
16. Assessment of the effect of testosterone on the acrosome reaction of human spermatozoa
- Author
-
Vigil, P., primary, Barrientos, V. M., additional, Vargas, G. G., additional, Machuca, D. A., additional, and Cortés, M. E., additional
- Published
- 2011
- Full Text
- View/download PDF
17. Estudio de la Expresión de los Receptores de Progesterona y Estrógeno en el Endometrio de Ovejas Alimentadas con Dieta Normal y Dieta Suplementada
- Author
-
Vasconcellos C, Adriana, primary, Paredes H, Marco, additional, Núñez R, Daniela, additional, Barrientos V, Eduardo, additional, Olmazábal S, Yoselyn, additional, and V, Javiera, additional
- Published
- 2010
- Full Text
- View/download PDF
18. Characterization and geochemical–geotechnical properties of granite sawdust produced by the dimension stone industry of O Porriño (Pontevedra, Spain)
- Author
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Barrientos, V., primary, Delgado, J., additional, Navarro, V., additional, Juncosa, R., additional, Falcón, I., additional, and Vázquez, A., additional
- Published
- 2010
- Full Text
- View/download PDF
19. Estado y Sociedad Civil: Interés Público e Interés Privado.
- Author
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Barrientos V., Juan A. and Barrientos V., Juan A.
- Published
- 2002
20. Análisis de la Expresión del Receptor del Estrógeno en Endometrio de Ovejas Alimentadas con Dieta Normal y Dieta Suplementada
- Author
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Vasconcellos C, Adriana, primary, Paredes H, Marco, additional, Barrientos V, Eduardo, additional, Olmazábal S, Yoselyn, additional, Núñez R, Daniela, additional, Navarrete V, Javiera, additional, and Molina E, Benedicto, additional
- Published
- 2009
- Full Text
- View/download PDF
21. Injection of CO2-Saturated Water through a Siliceous Sandstone Plug from the Hontomin Test Site (Spain): Experiment and Modeling.
- Author
-
Canal, J., Delgado, J., Falcón, I., Yang, Q., Juncosa, R., and Barrientos, V.
- Published
- 2013
- Full Text
- View/download PDF
22. Tratamiento de las fracturas intertrocantéricas con hemiartroplastía tipo Lazcano en el paciente anciano.
- Author
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Mcnaught-Salguero, C., Campos-Hernández, C. J., Rosas-Barrientos, V., and Matías-Barrón, P.
- Subjects
OSTEOPENIA ,TREATMENT of bone diseases ,ARTHROPLASTY ,PHYSICAL activity ,OLDER patients ,BONE fractures ,CASE-control method ,PATIENTS - Abstract
Copyright of Acta Ortopédica Mexicana is the property of Sociedad Mexicana de Ortopedia, AC and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2011
23. Geochemical assessment of the contaminant potential of granite fines produced during sawing and related processes associated to the dimension stone industry.
- Author
-
Delgado J., Barrientos V., Juncosa R., Vazquez A., Delgado J., Barrientos V., Juncosa R., and Vazquez A.
- Abstract
The environmental impact was investigated of high-pH water and the mobility of toxic metals, in particular Cr, in relation to the growth of the dimension stone industry in Galicia, Spain. Physicochemical, mineralogical and geomechanical characterisation of the fines was carried out and the effects were studied of the production cycle, including the use of steel grit and hydrated lime, the typical lithotype (Rosa Porrino) subjected to sawing and the hydrogeochemistry of the waters used in industrial processing. The results indicated that granite fines do not constitute a significant hazard to the quality of natural waters., The environmental impact was investigated of high-pH water and the mobility of toxic metals, in particular Cr, in relation to the growth of the dimension stone industry in Galicia, Spain. Physicochemical, mineralogical and geomechanical characterisation of the fines was carried out and the effects were studied of the production cycle, including the use of steel grit and hydrated lime, the typical lithotype (Rosa Porrino) subjected to sawing and the hydrogeochemistry of the waters used in industrial processing. The results indicated that granite fines do not constitute a significant hazard to the quality of natural waters.
24. Characterisation and geochemical-geotechnical properties of granite sawdust produced by the dimension stone industry of O Porrino (Pontevedra, Spain).
- Author
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Barrientos V., Delgado J., Falcon I., Juncosa R., Navarro V., Vazquez A., Barrientos V., Delgado J., Falcon I., Juncosa R., Navarro V., and Vazquez A.
- Abstract
A large amount of granite sawdust is generated during the sawing and preparation of dimension stone, with about 300 000 tpa produced in the O Porrino area in Galicia. Under current EU directives, granite sawdust is considered to be waste and its disposal must conform with environmental standards. The relevant Spanish laws have established the requirement for a strategy to characterise and assess sawdust products in order to integrate them into the dimension stone production cycle. Samples of granite sawdust produced using gang saws or diamond-edged disc saws were characterised in relation to their physicochemical, mineralogical and geotechnical properties and compaction and consolidation tests were also carried out. The low permeability of the sawdust suggests that it may be used as a liner or cover material for municipal waste landfills. It may also be employed to stabilise oily waste material, where the surface reactivity of the sawdust as expressed by the zeta potential may play an important role. It is also being considered as a passive treatment for acid mine drainage, on the basis of its moderate neutralisation potential., A large amount of granite sawdust is generated during the sawing and preparation of dimension stone, with about 300 000 tpa produced in the O Porrino area in Galicia. Under current EU directives, granite sawdust is considered to be waste and its disposal must conform with environmental standards. The relevant Spanish laws have established the requirement for a strategy to characterise and assess sawdust products in order to integrate them into the dimension stone production cycle. Samples of granite sawdust produced using gang saws or diamond-edged disc saws were characterised in relation to their physicochemical, mineralogical and geotechnical properties and compaction and consolidation tests were also carried out. The low permeability of the sawdust suggests that it may be used as a liner or cover material for municipal waste landfills. It may also be employed to stabilise oily waste material, where the surface reactivity of the sawdust as expressed by the zeta potential may play an important role. It is also being considered as a passive treatment for acid mine drainage, on the basis of its moderate neutralisation potential.
25. "Cuadratura extendida de Gauss – Legendre” (seminario de titulación carrera pedagogía matemáticas y física)
- Author
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Barrientos V., Rubén, primary and Hiplan A., Germán, additional
- Published
- 1983
- Full Text
- View/download PDF
26. Modification of the Official AOAC Method for Fat Content Determination of Dried Egg Yolk
- Author
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Navarro, J G, primary, Borie, F, primary, Barrientos, V, primary, and Caiozzi, M, primary
- Published
- 1971
- Full Text
- View/download PDF
27. Exogenous Volatile Organic Compound (EVOC ® ) Breath Testing Maximizes Classification Performance for Subjects with Cirrhosis and Reveals Signs of Portal Hypertension.
- Author
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Ferrandino G, Ricciardi F, Murgia A, Banda I, Manhota M, Ahmed Y, Sweeney K, Nicholson-Scott L, McConville L, Gandelman O, Allsworth M, Boyle B, Smolinska A, Ginesta Frings CA, Contreras J, Asenjo-Lobos C, Barrientos V, Clavo N, Novoa A, Riviotta A, Jerez M, and Méndez L
- Abstract
Background: Cirrhosis detection in primary care relies on low-performing biomarkers. Consequently, up to 75% of subjects with cirrhosis receive their first diagnosis with decompensation when causal treatments are less effective at preserving liver function. We investigated an unprecedented approach to cirrhosis detection based on dynamic breath testing. Methods: We enrolled 29 subjects with cirrhosis (Child-Pugh A and B), and 29 controls. All subjects fasted overnight. Breath samples were taken using Breath Biopsy
® before and at different time points after the administration of 100 mg limonene. Absolute limonene breath levels were measured using gas chromatography-mass spectrometry. Results: All subjects showed a >100-fold limonene spike in breath after administration compared to baseline. Limonene breath kinetics showed first-order decay in >90% of the participants, with higher bioavailability in the cirrhosis group. At the Youden index, baseline limonene levels showed classification performance with an area under the roc curve (AUROC) of 0.83 ± 0.012, sensitivity of 0.66 ± 0.09, and specificity of 0.83 ± 0.07. The best performing timepoint post-administration was 60 min, with an AUROC of 0.91, sensitivity of 0.83 ± 0.07, and specificity of 0.9 ± 0.06. In the cirrhosis group, limonene bioavailability showed a correlation with MELD and fibrosis indicators, and was associated with signs of portal hypertension. Conclusions: Dynamic limonene breath testing enhances diagnostic performance for cirrhosis compared to static testing. The correlation with disease severity suggests potential for monitoring therapeutic interventions. Given the non-invasive nature of breath collection, a dynamic limonene breath test could be implemented in primary care.- Published
- 2023
- Full Text
- View/download PDF
28. Myeloid- and epithelial-derived RELMα contribute to tissue repair following lung helminth infection.
- Author
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Sveiven SN, Kim SY, Barrientos V, Li J, Jennett J, Asiedu S, Anesko K, Nordgren TM, and Nair MG
- Abstract
Soil-transmitted helminth (STH) infections impact billions of individuals globally; however, there is a need to clarify the long-term impacts of these infections on pulmonary health owing to their transient migration and subsequent damage to the lungs. In mouse models of these infections using Nippostrongylus brasiliensis , lung pathology persists at later time points post single infection. These studies also indicate the persistent transcriptional expression of resistin-like molecule α (RELMα), an immunomodulatory protein induced in type 2 immunity and alternatively activated macrophages. Using constitutive and tamoxifen-inducible cell-specific RELMα knockout mouse strains, we identified that epithelial- and myeloid-derived RELMα protein remained elevated at 30 days post infection and altered the immune cell signature and gene expression in lung compartments. Histopathological assessment of alveolar damage revealed a role for RELMα in tissue repair, suggesting the importance of sustained RELMα expression for lung recovery from helminth infection. Acellular three-dimensional (3D) lung scaffolds were prepared from the lungs of wild-type (WT), RELMα KO-naive, or 30 days post N . brasiliensis -infected mice to assess their ability to support epithelial cell growth. N . brasiliensis infection significantly altered the scaffold and impaired epithelial cell growth and metabolic activity, especially in the RELMα KO scaffolds. These findings underscore a need to identify the long-term impacts of helminth infection on human pulmonary disease, particularly as alveolar destruction can develop into chronic obstructive pulmonary disease (COPD), which remains among the top global causes of death. Translation of these findings to human protein resistin, with sequence homology to RELMα therapeutic opportunities in lung repair., Competing Interests: Conflict of interest The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
- Published
- 2023
- Full Text
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29. Glucocorticoids Decrease Longitudinal Bone Growth in Pediatric Kidney Transplant Recipients by Stimulating the FGF23/FGFR3 Signaling Pathway.
- Author
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Delucchi Á, Toro L, Alzamora R, Barrientos V, González M, Andaur R, León P, Villanueva F, Galindo M, Las Heras F, Montecino M, Moena D, Lazcano A, Pinto V, Salas P, Reyes ML, Mericq V, and Michea L
- Subjects
- Animals, Bone Density drug effects, Bone and Bones pathology, Child, Female, Fibroblast Growth Factor-23, Follow-Up Studies, Glucocorticoids adverse effects, Humans, Kidney Failure, Chronic metabolism, Kidney Failure, Chronic pathology, Kidney Failure, Chronic surgery, Klotho Proteins, Male, Membrane Proteins, Mice, Rats, Rats, Sprague-Dawley, Bone Development drug effects, Bone and Bones metabolism, Fibroblast Growth Factors metabolism, Glucocorticoids administration & dosage, Kidney Transplantation, Receptor, Fibroblast Growth Factor, Type 3 metabolism, Signal Transduction drug effects
- Abstract
Renal transplantation (RTx) is an effective therapy to improve clinical outcomes in pediatric patients with terminal chronic kidney disease. However, chronic immunosuppression with glucocorticoids (GCs) reduces bone growth and BMD. The mechanisms causing GC-induced growth impairment have not been fully clarified. Fibroblast growth factor 23 (FGF23) is a peptide hormone that regulates phosphate homeostasis and bone growth. In pathological conditions, FGF23 excess or abnormal FGF receptors (FGFR) activity leads to bone growth impairment. Experimental data indicate that FGF23 expression is induced by chronic GC exposure. Therefore, we hypothesize that GCs impair bone growth by increasing FGF23 expression, which has direct effects on bone growth plate. In a post hoc analysis of a multicentric randomized clinical trial of prepubertal RTx children treated with early GC withdrawal or chronic GC treatment, we observed that GC withdrawal was associated with improvement in longitudinal growth and BMD, and lower plasma FGF23 levels as compared with a chronic GC group. In prepubertal rats, GC-induced bone growth retardation correlated with increased plasma FGF23 and bone FGF23 expression. Additionally, GC treatment decreased FGFR1 expression whereas it increased FGFR3 expression in mouse tibia explants. The GC-induced bone growth impairment in tibiae explants was prevented by blockade of FGF23 receptors using either a pan-FGFR antagonist (PD173074), a C-terminal FGF23 peptide (FGF23180-205) which blocks the binding of FGF23 to the FGFR-Klotho complex or a specific FGFR3 antagonist (P3). Finally, local administration of PD173074 into the tibia growth plate ameliorated cartilage growth impairment in GC-treated rats. These results show that GC treatment partially reduces longitudinal bone growth via upregulation of FGF23 and FGFR3 expression, thus suggesting that the FGF23/Klotho/FGFR3 axis at the growth plate could be a potential therapeutic target for the management of GC-induced growth impairment in children., (© 2019 American Society for Bone and Mineral Research.)
- Published
- 2019
- Full Text
- View/download PDF
30. Erythropoietin induces bone marrow and plasma fibroblast growth factor 23 during acute kidney injury.
- Author
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Toro L, Barrientos V, León P, Rojas M, Gonzalez M, González-Ibáñez A, Illanes S, Sugikawa K, Abarzúa N, Bascuñán C, Arcos K, Fuentealba C, Tong AM, Elorza AA, Pinto ME, Alzamora R, Romero C, and Michea L
- Subjects
- Acute Kidney Injury etiology, Animals, Bone Marrow Cells drug effects, Disease Models, Animal, Erythroid Precursor Cells drug effects, Erythropoietin pharmacology, Fibroblast Growth Factor-23, Humans, Male, Mice, Inbred C57BL, Prospective Studies, Rats, Sprague-Dawley, Receptors, Erythropoietin agonists, Receptors, Erythropoietin metabolism, Recombinant Proteins pharmacology, Sepsis blood, Sepsis complications, Shock, Hemorrhagic blood, Shock, Hemorrhagic complications, Time Factors, Up-Regulation, Acute Kidney Injury blood, Bone Marrow Cells metabolism, Erythroid Precursor Cells metabolism, Erythropoietin blood, Fibroblast Growth Factors blood
- Abstract
It is accepted that osteoblasts/osteocytes are the major source for circulating fibroblast growth factor 23 (FGF23). However, erythropoietic cells of bone marrow also express FGF23. The modulation of FGF23 expression in bone marrow and potential contribution to circulating FGF23 has not been well studied. Moreover, recent studies show that plasma FGF23 may increase early during acute kidney injury (AKI). Erythropoietin, a kidney-derived hormone that targets erythropoietic cells, increases in AKI. Here we tested whether an acute increase of plasma erythropoietin induces FGF23 expression in erythropoietic cells of bone marrow thereby contributing to the increase of circulating FGF23 in AKI. We found that erythroid progenitor cells of bone marrow express FGF23. Erythropoietin increased FGF23 expression in vivo and in bone marrow cell cultures via the homodimeric erythropoietin receptor. In experimental AKI secondary to hemorrhagic shock or sepsis in rodents, there was a rapid increase of plasma erythropoietin, and an induction of bone marrow FGF23 expression together with a rapid increase of circulating FGF23. Blockade of the erythropoietin receptor fully prevented the induction of bone marrow FGF23 and partially suppressed the increase of circulating FGF23. Finally, there was an early increase of both circulating FGF23 and erythropoietin in a cohort of patients with severe sepsis who developed AKI within 48 hours of admission. Thus, increases in plasma erythropoietin and erythropoietin receptor activation are mechanisms implicated in the increase of plasma FGF23 in AKI., (Copyright © 2017 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
- Full Text
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31. Mineralocorticoids modulate the expression of the β-3 subunit of the Na + , K + -ATPase in the renal collecting duct.
- Author
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Rojas M, Díaz P, León P, Gonzalez AA, González M, Barrientos V, Pestov NB, Alzamora R, and Michea L
- Subjects
- Aldosterone pharmacology, Animals, Cell Line, Cell Membrane metabolism, Epithelial Sodium Channel Agonists pharmacology, Epithelial Sodium Channels metabolism, Male, Rats, Sprague-Dawley, Kidney Tubules metabolism, Mineralocorticoids pharmacology, Sodium-Potassium-Exchanging ATPase metabolism
- Abstract
Renal sodium reabsorption depends on the activity of the Na
+ ,K+ -ATPase α/β heterodimer. Four α (α1-4 ) and 3 β (β1-3 ) subunit isoforms have been described. It is accepted that renal tubule cells express α1 /β1 dimers. Aldosterone stimulates Na+ ,K+ -ATPase activity and may modulate α1 /β1 expression. However, some studies suggest the presence of β3 in the kidney. We hypothesized that the β3 isoform of the Na+ ,K+ -ATPase is expressed in tubular cells of the distal nephron, and modulated by mineralocorticoids. We found that β3 is highly expressed in collecting duct of rodents, and that mineralocorticoids decreased the expression of β3 . Thus, we describe a novel molecular mechanism of sodium pump modulation that may contribute to the effects of mineralocorticoids on sodium reabsorption.- Published
- 2017
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32. Spironolactone decreases DOCA-salt-induced organ damage by blocking the activation of T helper 17 and the downregulation of regulatory T lymphocytes.
- Author
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Amador CA, Barrientos V, Peña J, Herrada AA, González M, Valdés S, Carrasco L, Alzamora R, Figueroa F, Kalergis AM, and Michea L
- Subjects
- Animals, Antibodies immunology, Antibodies pharmacology, Desoxycorticosterone Acetate pharmacology, Disease Models, Animal, Down-Regulation drug effects, Down-Regulation physiology, Forkhead Transcription Factors drug effects, Forkhead Transcription Factors physiology, Heart Diseases etiology, Heart Diseases physiopathology, Hypertension complications, Hypertension physiopathology, Interleukin-17 antagonists & inhibitors, Interleukin-17 immunology, Interleukin-17 physiology, Kidney Diseases etiology, Kidney Diseases physiopathology, Male, Mineralocorticoid Receptor Antagonists pharmacology, Rats, Rats, Sprague-Dawley, Receptors, Mineralocorticoid drug effects, Receptors, Mineralocorticoid physiology, Signal Transduction drug effects, Signal Transduction physiology, T-Lymphocytes, Regulatory pathology, Th17 Cells pathology, Desoxycorticosterone Acetate adverse effects, Heart Diseases prevention & control, Hypertension chemically induced, Kidney Diseases prevention & control, Spironolactone pharmacology, T-Lymphocytes, Regulatory drug effects, Th17 Cells drug effects
- Abstract
Adaptive immune response has been implicated in inflammation and fibrosis as a result of exposure to mineralocorticoids and a high-salt diet. We hypothesized that in mineralocorticoid-salt-induced hypertension, activation of the mineralocorticoid receptor alters the T-helper 17 lymphocyte (Th17)/regulatory T-lymphocyte/interleukin-17 (IL-17) pathway, contributing to cardiac and renal damage. We studied the inflammatory response and tissue damage in rats treated with deoxycorticosterone acetate and high-salt diet (DOCA-salt), with or without mineralocorticoid receptor inhibition by spironolactone. To determine whether Th17 differentiation in DOCA-salt rats is caused by hypertension per se, DOCA-salt rats received antihypertensive therapy. In addition, to evaluate the pathogenic role of IL-17 in hypertension and tissue damage, we studied the effect of IL-17 blockade with a specific antibody (anti-IL-17). We found activation of Th17 cells and downregulation of forkhead box P3 mRNA in peripheral tissues, heart, and kidneys of DOCA-salt-treated rats. Spironolactone treatment prevented Th17 cell activation and increased numbers of forkhead box P3-positive cells relative to DOCA-salt rats. Antihypertensive therapy did not ameliorate Th17 activation in rats. Treatment of DOCA-salt rats with anti-IL-17 significantly reduced arterial hypertension as well as expression of profibrotic and proinflammatory mediators and collagen deposits in the heart and kidney. We conclude that mineralocorticoid receptor activation alters the Th17/regulatory T-lymphocyte/IL-17 pathway in mineralocorticoid-dependent hypertension as part of an inflammatory mechanism contributing to fibrosis.
- Published
- 2014
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- View/download PDF
33. Angiotensin-(1-9) reverses experimental hypertension and cardiovascular damage by inhibition of the angiotensin converting enzyme/Ang II axis.
- Author
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Ocaranza MP, Moya J, Barrientos V, Alzamora R, Hevia D, Morales C, Pinto M, Escudero N, García L, Novoa U, Ayala P, Díaz-Araya G, Godoy I, Chiong M, Lavandero S, Jalil JE, and Michea L
- Subjects
- Angiotensin II Type 1 Receptor Blockers chemistry, Animals, Aorta pathology, Blood Pressure drug effects, Cardiovascular Diseases prevention & control, Disease Models, Animal, Echocardiography, Endothelium, Vascular pathology, Heart Ventricles, Hemodynamics, Hypertension physiopathology, Imidazoles chemistry, Male, Oxidative Stress, Pyridines chemistry, Rats, Rats, Sprague-Dawley, Angiotensin I chemistry, Angiotensin II chemistry, Angiotensin-Converting Enzyme Inhibitors chemistry, Cardiovascular Diseases drug therapy, Hypertension drug therapy, Peptide Fragments chemistry
- Abstract
Background: Little is known about the biological effects of angiotensin-(1-9), but available evidence shows that angiotensin-(1-9) has beneficial effects in preventing/ameliorating cardiovascular remodeling., Objective: In this study, we evaluated whether angiotensin-(1-9) decreases hypertension and reverses experimental cardiovascular damage in the rat., Methods and Results: Angiotensin-(1-9) (600 ng/kg per min for 2 weeks) reduced already-established hypertension in rats with early high blood pressure induced by angiotensin II infusion or renal artery clipping. Angiotensin-(1-9) also improved cardiac (assessed by echocardiography) and endothelial function in small-diameter mesenteric arteries, cardiac and aortic wall hypertrophy, fibrosis, oxidative stress, collagen and transforming growth factor type β - 1 protein expression (assessed by western blot). The beneficial effect of angiotensin-(1-9) was blunted by coadministration of the angiotensin type 2(AT2) receptor blocker PD123319 (36 ng/kg per min) but not by coadministration of the Mas receptor blocker A779 (100 ng/kg per min). Angiotensin-(1-9) treatment also decreased circulating levels of Ang II, angiotensin-converting enzyme activity and oxidative stress in aorta and left ventricle. Whereas, Ang-(1-9) increased endothelial nitric oxide synthase mRNA levels in aorta as well as plasma nitrate levels., Conclusion: Angiotensin-(1-9) reduces hypertension, ameliorates structural alterations (hypertrophy and fibrosis), oxidative stress in the heart and aorta and improves cardiac and endothelial function in hypertensive rats. These effects were mediated by the AT2 receptor but not by the angiotensin-(1-7)/Mas receptor axis.
- Published
- 2014
- Full Text
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34. Injection of CO2-saturated water through a siliceous sandstone plug from the Hontomin test site (Spain): experiment and modeling.
- Author
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Canal J, Delgado J, Falcón I, Yang Q, Juncosa R, and Barrientos V
- Subjects
- Carbon Sequestration, Spain, Water chemistry, Carbon Dioxide chemistry, Minerals chemistry, Models, Theoretical
- Abstract
Massive chemical reactions are not expected when injecting CO(2) in siliceous sandstone reservoirs, but their performance can be challenged by small-scale reactions and other processes affecting their transport properties. We have conducted a core flooding test with a quartzarenite plug of Lower Cretaceous age representative of the secondary reservoir of the Hontomín test site. The sample, confined at high pressure, was successively injected with DIW and CO(2)-saturated DIW for 49 days while monitoring geophysical, chemical, and hydrodynamic parameters. The plug experienced little change, without evidence of secondary carbonation. However, permeability increased by a factor of 4 (0.022-0.085 mD), and the V(P)/V(S) ratio, whose change is related with microcracking, rose from ~1.68 to ~1.8. Porosity also increased (7.33-8.1%) from the beginning to the end of the experiment. Fluid/rock reactions were modeled with PHREEQC-2, and they are dominated by the dissolution of Mg-calcite. Mass balances show that ~4% of the initial carbonate was consumed. The results suggest that mineral dissolution and microcracking may have acted in a synergistic way at the beginning of the acidic flooding. However, dissolution processes concentrated in pore throats can better explain the permeability enhancement observed over longer periods of time.
- Published
- 2013
- Full Text
- View/download PDF
35. Mechanisms of Oryza sativa (Poaceae) resistance to Tagosodes orizicolus (Homoptera: Delphacidae) under greenhouse condition in Venezuela.
- Author
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González A, Labrín N, Alvarez RM, Jayaro Y, Gamboa C, Reyes E, and Barrientos V
- Subjects
- Animals, Antibiosis physiology, Genotype, Oryza genetics, Venezuela, Hemiptera physiology, Host-Parasite Interactions, Oryza parasitology
- Abstract
Tagosodes orizicolus is one of the main plagues of rice in tropical America causing two types of damages, the direct one, feeding and oviposition effect, and an indirect one, by the transmission of the "Rice hoja blanca virus". During 2006-2007 we carried out research under greenhouse conditions at Fundaci6n Danac, Venezuela, in order to determine the mechanisms of antixenosis, antibiosis and tolerance to T. orizicolus, which could be acting in commercial varieties and advanced lines of the rice genetic breeding programs of INIA and Fundaci6n Danac. The method of free feeding was used for the antixenosis evaluation, whereas the method of forced feeding was used for antibiosis evaluation (effect on survival and oviposition). Additionally, we used the indirect method based on biomass depression to estimate the tolerance. Some of the evaluated traits included: grade of damage, number of insects settling on rice plants, percentage of sogata mortality at the mature state, number of eggs in the leaf midrib and an index of tolerance. The results showed that rice genotypes possess different combinations of resistance mechanisms, as well as different grades of reactions. The susceptible control 'Bluebonnet 50' was consistently susceptible across experiments and the resistant control 'Makalioka' had high antixenosis and high antibiosis based on survival and oviposition. The rest of the genotypes presented lower or higher degrees of antixenosis and antibiosis for survival and oviposition. The genotype 'FD0241-M-17-6-1-1-1-1' was identified with possible tolerance to the direct damage of sogata.
- Published
- 2012
36. [Management of intertrochanteric fractures with lazcano hemiarthroplasty in elderly patients].
- Author
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McNaught-Salguero C, Campos-Hernández CJ, Rosas-Barrientos V, and Matías-Barrón P
- Subjects
- Aged, 80 and over, Bone Diseases, Metabolic complications, Case-Control Studies, Female, Hip Fractures etiology, Humans, Male, Arthroplasty, Replacement, Hip methods, Hip Fractures surgery
- Abstract
Objective: To determine if elderly osteopenic patients sustaining an intertrochanteric fracture recover sooner when treated with Lazcano hemiarthroplasty compared with those treated with internal fixation, and whether they can return to their prefracture physical activity level., Methods: A case-control study was conducted at 1o de Octubre ISSSTE Hospital. Patients over age 70 with intertrochanteric hip fracture and advanced osteopenia were enrolled. The cases were treated with Lazcano hemiarthroplasty and the controls (20 patients) with standard internal fixation (angled plate, DHS system, gamma nail). The comorbid conditions and the prefracture activity level were assessed in both groups. The relation between comorbid conditions and complications was studied and the postoperative activity level of both groups was compared., Results: Thirty patients with these characteristics were included. Ten were cases and 20 were controls. No relation was found between the comorbid conditions and the patients' ability to resume gait postoperatively. Patients treated with hemiarthroplasty walk sooner than those treated with standard internal fixation and have a lower complication rate., Conclusions: The Lazcano hemiarthroplasty is an excellent choice in the treatment of intertrochanteric fractures in osteopenic patients. Long-term studies with more patients are required to assess the presence of complications.
- Published
- 2011
37. [Fatty acids profile characterization of white maize hybrids grown in Venezuela].
- Author
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Alezones J, Avila M, Chassaigne A, and Barrientos V
- Subjects
- Chromatography, Gas, Venezuela, Zea mays classification, Chimera, Fatty Acids, Unsaturated analysis, Plant Oils chemistry, Zea mays chemistry
- Abstract
In Venezuela, white corn is the most important crop regarding production, harvest area and consumption. One of its main by-products is corn oil, whose positive effect on health caused by the high content of unsaturated fatty acids has been widely recognized. In order to characterize the fatty acids profile of twelve white grained maize hybrids extensively grown in Venezuela, and the effect that divergent localities has on this profile, three semi commercial scale trials where established in Portuguesa, Yaracuy and Guárico states. Proportions of the main fatty acids in the raw oil of the different grain samples were determined using gas chromatography. Significant differences (p < 0,01) between hybrids were found for arachidic, palmitic, stearic, oleic, gadoleic and linoleic acids; non significant differences were found for linolenic acid. Significant differences between localities were found for all the fatty acids evaluated. High and significant correlations between fatty acids content were found; the most important relations were: linoleic-oleic (Rho = -0,98**), arachidic-palmitic (Rho = -0,61**), linoleic-stearic (Rho = -0,61**) and oleic-stearic (Rho = 0,58**). Corn produced in Venezuela presents lower levels of linoleic and higher levels of palmitic, stearic and oleic acids than the levels found in temperate corn. These differences involve significant changes in the nutritional properties of Venezuelan corn oil that should be considered in the development of new cultivars and industrial processes for oil production.
- Published
- 2010
38. Modification of the official AOAC method for fat content determination of dried egg yolk.
- Author
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Navarro JG, Borie F, Barrientos V, and Caiozzi M
- Subjects
- Chromatography, Gas, Evaluation Studies as Topic, Fatty Acids analysis, Female, Food Preservation, Methods, Societies, Scientific, Egg Yolk analysis, Lipids analysis
- Published
- 1971
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