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Search Results: 1 - 10 of 6798 matches for " Guillermo Valdivia Anda "
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Stimulation of Phagocytosis and Production of Antibodies against Canine Herpesvirus Type 1 by Pidotimod (AdimodTM)  [PDF]
Edgar G. Valdivia Lara, Andrés ángeles Aldana, Jesica I. ángeles Solis, Patricia Miranda Castro, Juan C. Del Río García, Guillermo Valdivia Anda
Open Journal of Veterinary Medicine (OJVM) , 2017, DOI: 10.4236/ojvm.2017.74005
Abstract: Neutrophils are the most important circulating phagocytes. Circulating mono-cytes and precursors of tissue macrophages also have the ability to phagocytize. Pidotimod (ADIMODTM) exerts immunostimulatory and immunoregulatory effects through the stimulation and regulation of cellular immune responses by lymphocytes Canine herpesvirus (CHV) mainly affect puppies between the first and second weeks of age, causing high morbidity in the litter. To date, there is only one commercial vaccine in Europe to prevent disease. In this work, inactivated CHV cultures were inoculated in rabbits, adsorbed and not adsorbed to chitosan nanoparticles. Phagocytosis in the presence or absence of specific antibodies was measured. Response of virus neutralizing antibodies was also evaluated. AdimodTM enhanced the nonspecific and specific phagocytotic response. The association of the virus to the nanoparticles increased the phagocytic ability of blood cells; however, AdimodTM alone had a greater effect on phagocytic activity and generated a stronger immune response that corresponded to the increased phagocytosis (p < 0.05). Moreover, the level of neutralizing antibodies was higher and increased more rapidly when AdimodTM was used.
Pathology Isolation and Identification of Canine Herpesvirus (CHV-1) in Mexico  [PDF]
E. Guillermo Valdivia Lara, Blanca Lilia Barrón Romero, Laura Cobos Marín, Jessica Ileana ángeles Solis, Sofía González Gallardo, Cesar Cuenca Verde, Juan Antonio Montaraz Crespo, Guillermo Valdivia Anda
Open Journal of Pathology (OJPathology) , 2016, DOI: 10.4236/ojpathology.2016.63014
Abstract: This work presents the pathology description, isolation and identification of canine herpesvirus (CHV-1) in Mexico, a virus that causes a generalized hemorrhagic infection in puppies from the canidae family. Methods: Isolates were obtained from puppies that died within the first four weeks of life and had lesions consistent with canine herpesvirus. Results: The main gross lesions were petechial and ecchymotic hemorrhages in kidneys, liver and lungs; proliferative interstitial nephritis; multifocal necrosis in liver and kidneys; and encephalitis with intranuclear inclusion bodies. Herpesvirus was confirmed through direct immunofluorescence, electron microscopy and polymerase chain reaction for DNA polymerase and glycoprotein B genes. Discussion: Eight strains were isolated and identified as canine herpesvirus corresponding to three of the working cases with gross and microscopic lesions very similar to those described in the literature; then, isolates were confirmed by PCR gene amplification, positive reactions on immunofluorescence and observations from electron microscopy. This work represents the first report of this disease, including gross and histological lesions, and confirmation by isolation and identification of the canine herpesvirus in Mexico.
Canine Herpesvirus Seroprevalence and Associated Factors in Dogs of Mexico  [PDF]
Edgar Guillermo Valdivia Lara, Jesica Ileana ángeles Solis, Cesar Cuenca Verde, Juan Antonio Montaraz Crespo, Laura Cobos Marín, Juan Carlos Del Río García, Guillermo Valdivia Anda
Open Journal of Veterinary Medicine (OJVM) , 2016, DOI: 10.4236/ojvm.2016.610019
Canine herpesvirus (CHV-1) causes disease associated with high mortality in infect-ed puppies, which represents large financial losses for dog breeders. Since CHV-1 at the time of the study he had not been reported in Mexico, the main objective of this study was to determine the prevalence of antibodies against CHV-1 in canine kennels in the metropolitan area of Mexico City. A commercial enzyme-linked immuno-sorbent assay (ELISA) was used, and the results were compared to those of a viral neutralization test. The ELISA kit uses the complete viral particle as the antigen. The plaque reduction neutralization test was combined with the immunoperoxidase technique because of the low cytopathic effect of CHV-1. Neutralizing antibodies were also detected in 20 randomly selected samples. The prevalence of CHV-1 with ELISA was 87%. The concordance between ELISA and serum neutralization (SN) was 0.1129, the sensitivity of the ELISA against SN was 1.0 (100%), the positive predic-tive value was 0.39 (39%), and the negative predictive value was 1 (100%). These results show that ELISA is useful for monitoring the dog population for CHV-1; a positive test result requires confirmation with an SN test, and a negative ELISA result indicates a high probability of being SN-negative. The only variables that were sta-tistically associated with CHV-1 prevalence were breed and kennel. A statistically significant relationship between the degree of ELISA and SN titer was obtained, with a confidence level of 95%. None of the clinical presentation factors was statistically significant. These results suggest that most of the canine population studied in Mex-ico is in a herpesvirus latency state.
Interacción de cepas verocitoóxicas de Escherichia coli y rotavirus en un brote de diarrea en becerros
Guillermo Valdivia Anda,Rocío Cervantes Rosales,Diana M. Soriano Becerril,Fernando Alba Hurtado
Veterinaria México , 2000,
Aspectos morfológicos e inmunológicos del apéndice cecal del conejo.
Guillermo Valdivia Anda,Norhan Cortés Fernández de Arcipreste,Fernando Alba Hurtado,Humberto Alejandro Martínez Rodríguez
Veterinaria México , 2007,
Abstract: El conejo se ha utilizado durante muchos a os como animal de laboratorio; sin embargo, a la fecha se conoce poco del funcionamiento preciso de algunos de sus órganos, como el apéndice cecal. El objetivo del presente trabajo fue describir algunos aspectos relacionados con la composición de linfocitos para entender ciertas respuestas inmunológicas de ese órgano en modelos animales. Se realizó un estudio anatómico, histológico e inmunohistológico del apéndice cecal del conejo de la raza Nueva Zelanda, desde el feto hasta los tres a os, mediante técnicas convencionales de disección, microscopía con cortes en parafi na te idos por hematoxilina y eosina, así como técnicas de inmunoperoxidasa para marcadores de diferenciación de linfocitos CD4, CD43, CD25 y CD5; para buscar células plasmáticas se usaron técnicas de histoquímica. De este modo, los linfocitos marcados se contaron mediante microscopía óptica acoplada a un analizador de imágenes. Se observaron cambios en la mucosa y en la submucosa con dos tipos de proyecciones, vellosidad y domo, con un epitelio que sugiere una función de absorción/secreción en la vellosidad, y de intercambio antigénico en el domo. La población de linfocitos fue mayor y más defi nida en el domo (P < 0.05) y está constituida por dos nódulos linfoides, el superfi cial en la mucosa con predominio de linfocitos T activos y de respuesta, marcados con CD43, y el más profundo en la submucosa con linfocitos CD4 y células plasmáticas (P < 0.05). Se adquiere el desarrollo estructural pleno del apéndice a los 30 días de edad; en los animales de 60 días se observó que el nódulo de la mucosa tiene características de zona linfoide secundaria, semejando una placa de Peyer yeyunal; mientras el profundo mantiene características de área linfoide primaria, semejando la Bolsa de Fabricio, que se desarrolla desde el nacimiento y persiste toda la vida.
Metabolic engineering for the production of shikimic acid in an evolved Escherichia coli strain lacking the phosphoenolpyruvate: carbohydrate phosphotransferase system
Adelfo Escalante, Rocío Calderón, Araceli Valdivia, Ramón de Anda, Georgina Hernández, Octavio T Ramírez, Guillermo Gosset, Francisco Bolívar
Microbial Cell Factories , 2010, DOI: 10.1186/1475-2859-9-21
Abstract: Batch cultures were performed to evaluate the effects of genetic modifications on growth, glucose consumption, and aromatic intermediate production. All derivatives showed a two-phase growth behavior with initial high specific growth rate (μ) and specific glucose consumption rate (qs), but low level production of aromatic intermediates. During the second growth phase the μ decreased, whereas aromatic intermediate production reached its maximum. The double aroK- aroL- mutant expressing plasmid-coded genes (strain PB12.SA22) accumulated SA up to 7 g/L with a yield of SA on glucose of 0.29 mol/mol and a total aromatic compound yield (TACY) of 0.38 mol/mol. Single inactivation of pykF or pykA was performed in PB12.SA22 strain. Inactivation of pykF caused a decrease in μ, qs, SA production, and yield; whereas TACY increased by 33% (0.5 mol/mol).The effect of increased availability of carbon metabolites, their channeling into the synthesis of aromatic intermediates, and disruption of the SA pathway on SA production was studied. Inactivation of both aroK and aroL, and transformation with plasmid-coded genes resulted in the accumulation of SA up to 7 g/L with a yield on glucose of 0.29 mol/mol PB12.SA22, which represents the highest reported yield. The pykF and pykA genes were inactivated in strain PB12.SA22 to increase the production of aromatic compounds in the PTS- background. Results indicate differential roles of Pyk isoenzymes on growth and aromatic compound production. This study demonstrated for the first time the simultaneous inactivation of PTS and pykF as part of a strategy to improve SA production and its aromatic precursors in E. coli, with a resulting high yield of aromatic compounds on glucose of 0.5 mol/mol.The shikimic acid (SA) pathway is the common route leading to the biosynthesis of aromatic compounds in bacteria and in several eukaryotic organisms such as ascomycetes fungi, apicomplexans, and plants [1,2]. In Escherichia coli, the first step in this pa
Transport in a mesoscopic ring with a quantum dot: from the Coulomb blockade regime to the Kondo effect
Valeria Ferrari,Guillermo Chiappe,Enrique Anda
Physics , 2000,
Abstract: The system described in this work consists of a quantum dot inserted in a mesoscopic ring threaded by a magnetic flux. Our aim is to present a complete description for this device and to predict the physics of a experiment with these features. We have proposed a model that takes into account the conditions that are usual in experiments with quantum dots and mesoscopic systems. In order to solve the model, we develop a methodology to find the Green's functions of the system by means of proper approximations. This system presents persistent currents as a function of a gate potential applied to the quantum dot. We have studied the influence of both the interaction between electrons and the hybridization between the ring and the dot. We have found several regimes that describe different physical phenomena involved in the system. These regimes range from the phenomenon of Coulomb Blockade (in the high correlation limit) to a quasi non interacting regime. Between these two limits we have found an intermediate regime where the Kondo effect shows up.
Investigation of DNA Sequences Related to Latency-Associated Transcripts in the Genome of Canine Herpesvirus Type 1 (CHV-1) by Means of Bioinformatics Tools  [PDF]
Ortiz M. A. Hernández, Verde C. Cuenca, Lara E. G. Valdivia, Anda G. Valdivia
Open Journal of Veterinary Medicine (OJVM) , 2019, DOI: 10.4236/ojvm.2019.910013
Abstract: A characteristic common to herpesviruses is the ability to establish a latent infection in the hosts, a transcriptionally active region has detected during latency as well as a set of RNA that are known as Latency Associated Transcripts (LATs), their functions have been clarified in recent work. The present work was carried using different bioinformatics method in order to determine if Herpesvirus Canine 1 (CHV-1) has a region associated with latency. Our result was the selection of nine sequences candidate of micro RNA (miRNA) (MIREval 2.0 software), and 26 miRNA (miRNAFold v.1.0 software), of them, were selected 14 with real precursors of miRNA, two were found between the RL2 and RS1 genes, one in the RL2 gene and 11 in the RS1 gene. The results showed that the similarities of these regions are very low among the herpesviruses analyzed, so it was not possible to deduce the presence of the LAT gene in canine herpesvirus type 1 with bioinformatics. On the other hand, the comparison showed that the miRNA predicted: chv1-mir-mirnafold-8 has similarity with the ebv-mir-BART7-3p of Epstein-Barr Virus (EBV), in this way, the microRNAs predicted by means of bioinformatic programs met the theoretical requirements of these molecules, however at not having a degree of preservation in other herpesviruses, the expression by CHV-1 in latency cannot be confirmed and it is necessary to identify through experimental tests.
Kondo resonance effect on persistent currents through a quantum dot in a mesoscopic ring
Valeria Ferrari,Guillermo Chiappe,Enrique V. Anda,Maria A. Davidovich
Physics , 1999, DOI: 10.1103/PhysRevLett.82.5088
Abstract: The persistent current through a quantum dot inserted in a mesoscopic ring of length L is studied. A cluster representing the dot and its vicinity is exactly diagonalized and embedded into the rest of the ring. The Kondo resonance provides a new channel for the current to flow. It is shown that due to scaling properties, the persistent current at the Kondo regime is enhanced relative to the current flowing either when the dot is at resonance or along a perfect ring of same length. In the Kondo regime the current scales as $L^{-1/2}$, unlike the $L^{-1}$ scaling of a perfect ring. We discuss the possibility of detection of the Kondo effect by means of a persistent current measurement.
Cambios recientes en la mortalidad por cáncer de próstata en Chile: estudio de tendencias en el período 1955-2001
Vives V,Alejandra; Valdivia C,Gonzalo; Marshall R,Guillermo;
Revista médica de Chile , 2004, DOI: 10.4067/S0034-98872004000500007
Abstract: background: by the year 2000, prostate cancer became the second leading cause of cancer death in chilean men of all ages and is the leading cause of cancer deaths in men of eighty years of age or older. aim: to analyze the trends in mortality rates from prostate cancer in chile in a fifty years series, estimating the rate of increase of such rates and their changes in time. material and methods: a trend analysis for age standardized mortality rates was performed, using join point regression analysis, which allows estimation of the annual percent change of rates and to find significant changes in such trend. results: age standardized mortality rates in chile reached their peak value in 1996, becoming apparently stable from then on. crude rates have had a steady increase during the whole period. the trends analysis identified three different periods in the growth of the age standardized rates: a first one of slow increase in rates between 1955 and 1981 (0.9% annual increase), a second one of more aggressive growth starting in 1981 (2.6% annual increase), and a third period starting in 1996, in which rates slowly decline at an annual rate of 1%. conclusions: the tendency of prostate cancer seen in chile resembles that of industrialized countries, with an increase in its age standardized death rates that suffers a downturn by the end of the past decade. besides early detection techniques, a substantial part of the reduction in mortality from prostate cancer could be explained by therapeutic improvements (rev méd chile 2004; 132: 579-87).
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