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Search Results: 1 - 10 of 4954 matches for " Rolando Rivera-Pomar "
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Cytoplasmic Ribonucleoprotein Foci in Eukaryotes: Hotspots of Bio(chemical)Diversity
Carla Layana,Paola Ferrero,Rolando Rivera-Pomar
Comparative and Functional Genomics , 2012, DOI: 10.1155/2012/504292
Abstract: The life of an mRNA from transcription to degradation offers multiple control check points that regulate gene expression. Transcription, splicing, and translation have been widely studied for many years; however, in recent years, new layers of posttranscriptional and posttranslational control have been uncovered. They involve the regulation of the metabolism of mRNA in cytoplasmic foci. They are collections of ribonucleoprotein complexes that, in most cases, remain still uncharacterized, except the processing bodies (PBs) and stress granules (SGs), which have been studied (and reviewed) in detail. A challenging prospective is to know how many different classes of foci exist, which functions they support, how are they formed, and how do they relate one to each other. Here, we present an update of the component of the different granules, a possible function, and hypothesis on their in vivo dynamics related to translational control.
Cytoplasmic Ribonucleoprotein Foci in Eukaryotes: Hotspots of Bio(chemical)Diversity
Carla Layana,Paola Ferrero,Rolando Rivera-Pomar
International Journal of Genomics , 2012, DOI: 10.1155/2012/504292
Abstract: The life of an mRNA from transcription to degradation offers multiple control check points that regulate gene expression. Transcription, splicing, and translation have been widely studied for many years; however, in recent years, new layers of posttranscriptional and posttranslational control have been uncovered. They involve the regulation of the metabolism of mRNA in cytoplasmic foci. They are collections of ribonucleoprotein complexes that, in most cases, remain still uncharacterized, except the processing bodies (PBs) and stress granules (SGs), which have been studied (and reviewed) in detail. A challenging prospective is to know how many different classes of foci exist, which functions they support, how are they formed, and how do they relate one to each other. Here, we present an update of the component of the different granules, a possible function, and hypothesis on their in vivo dynamics related to translational control. 1. Introduction In recent years, several cytoplasmic foci/granules that contain proteins and RNA have been described. Two of them have been studied in more detail as they are related to mRNA silencing: stress granules (SG) and processing bodies (PB). SG are repressed mRNPs transiently induced in response to cellular stress. They range from 0,5 to 5?μm [1]. PB are discrete RNP cytoplasmic foci of 0,1-2?μm where the machinery of RNA interference, degradation and storage locates. In PB the mRNAs are forming mRNP complexes either repressing translation, in degradation complexes or stored for further use [2, 3]. SG and PB have been shown to share a growing number of proteins that are added in a day-to-day basis to the list of their components. SG, PB and other cytoplasmic foci are highly dynamic structures, although PB are quite stable over the time [4]; see also Supplementary Movie 1 available online at http://dx.doi.org/10.1155/2012/504292. They are in a dynamic steady state with other mRNPs, such as polysomes in response to the translational state of the cell [5]. Although we do not intend to extensively review SG and PB, which have been matter of fine reviews in the last years [6–10], we will overview their functions before we address neglected issues and hypothesis. 2. Stress Granules Translation initiation is the key regulatory step of translational control. Therefore, it is the most sensitive step to changes in the cellular environment, including stress. A key step in translation initiation inhibition is the phosphorylation of eIF2α, which results in an increase on the affinity of eIF2-GDP for eIF2B, sequestering this factor
Culture-independent characterization of the bacterioplankton community composition of a mesotrophic reservoir (Embalse Río III, Argentina) Caracterización independiente de la composición de la comunidad del bacterioplancton en un embalse mesotrófico (embalse Río III, Argentina)
Daniela Polverino,Alejandro J. Mari?elarena,Christina B. McCarthy,Rolando V Rivera-Pomar
Revista mexicana de biodiversidad , 2012,
Abstract: This study represents the first analysis of the bacterioplankton community structure from a freshwater reservoir of Argentina using amplification of the entire 16S rDNA gene. It includes the description and the phylogenetic relationships of the bacterioplankton community from the photic and aphotic layers of the Río III Reservoir in Córdoba, Argentina. The classical ecological approach indicated that the photic layer had greater diversity whereas the aphotic layer had a better distribution of species and higher abundance. Nevertheless, when the microbial communities in both layers were compared using phylogenetic information, this analysis indicated that both environments were similar and that neither was enriched for any particular lineage. The phyla present in the Río III reservoir were Acidobacteria, Actinobacteria, and Proteobacteria and the 2 dominant species in both layers were "Candidatus Planktophila sp." (class Actinobacteria) and Polynucleobacter sp. (class Betaproteobacteria). Este estudio constituye el primer análisis de la estructura de la comunidad del bacterioplancton en un reservorio de agua dulce de Argentina utilizando amplificación completa del gen ADNr 16S. Incluye las relaciones filogenéticas y una descripción del bacterioplacton de las zonas fótica y afótica del Embalse Río III, Córdoba, Argentina. El análisis ecológico clásico indicó que la zona fótica tenía mayor diversidad, mientras que la afótica tenía mayor abundancia y una distribución más uniforme de especies. Sin embargo, cuando se utilizó la información filogenética para comparar las comunidades microbianas de ambas zonas, este análisis indicó que ambos ambientes eran similares y que en ninguno predominaba algún linaje en particular. Los phyla identificados en el Embalse del Río III fueron Acidobacteria, Actinobacteria y Proteobacteria. Las especies dominantes en ambas zonas fueron "Candidatus Planktophila sp." (clase Actinobacteria) y Polynucleobacter sp. (clase Betaproteobacteria).
L925I Mutation in the Para-Type Sodium Channel Is Associated with Pyrethroid Resistance in Triatoma infestans from the Gran Chaco Region
Natalia Capriotti,Gastón Mougabure-Cueto,Rolando Rivera-Pomar,Sheila Ons
PLOS Neglected Tropical Diseases , 2014, DOI: 10.1371/journal.pntd.0002659
Abstract: Background Chagas' disease is an important public health concern in Latin America. Despite intensive vector control efforts using pyrethroid insecticides, the elimination of Triatoma infestans has failed in the Gran Chaco, an ecoregion that extends over Argentina, Paraguay, Bolivia and Brazil. The voltage-gated sodium channel is the target site of pyrethroid insecticides. Point mutations in domain II region of the channel have been implicated in pyrethroid resistance of several insect species. Methods and Findings In the present paper, we identify L925I, a new pyrethroid resistance-conferring mutation in T. infestans. This mutation has been found only in hemipterans. In T. infestans, L925I mutation occurs in a resistant population from the Gran Chaco region and is associated with inefficiency in the control campaigns. We also describe a method to detect L925I mutation in individuals from the field. Conclusions and Significance The findings have important implications in the implementation of strategies for resistance management and in the rational design of campaigns for the control of Chagas' disease transmission.
An Insight into the Transcriptome of the Digestive Tract of the Bloodsucking Bug, Rhodnius prolixus
José M. C. Ribeiro ,Fernando A. Genta,Marcos H. F. Sorgine,Raquel Logullo,Rafael D. Mesquita,Gabriela O. Paiva-Silva,David Majerowicz,Marcelo Medeiros,Leonardo Koerich,Walter R. Terra,Clélia Ferreira,André C. Pimentel,Paulo M. Bisch,Daniel C. Leite,Michelle M. P. Diniz,Jo?o Lídio da S. G. V. Junior,Manuela L. Da Silva,Ricardo N. Araujo,Ana Caroline P. Gandara,Sébastien Brosson,Didier Salmon,Sabrina Bousbata,Natalia González-Caballero,Ariel Mariano Silber,Michele Alves-Bezerra,Katia C. Gondim,Mário Alberto C. Silva-Neto,Georgia C. Atella,Helena Araujo,Felipe A. Dias,Carla Polycarpo,Raquel J. Vionette-Amaral,Patrícia Fampa,Ana Claudia A. Melo,Aparecida S. Tanaka,Carsten Balczun,José Henrique M. Oliveira,Renata L. S. Gon?alves,Cristiano Lazoski,Rolando Rivera-Pomar,Luis Diambra,Günter A. Schaub,Elói S. Garcia,Patrícia Azambuja,Glória R. C. Braz ,Pedro L. Oliveira
PLOS Neglected Tropical Diseases , 2014, DOI: 10.1371/journal.pntd.0002594
Abstract: The bloodsucking hemipteran Rhodnius prolixus is a vector of Chagas' disease, which affects 7–8 million people today in Latin America. In contrast to other hematophagous insects, the triatomine gut is compartmentalized into three segments that perform different functions during blood digestion. Here we report analysis of transcriptomes for each of the segments using pyrosequencing technology. Comparison of transcript frequency in digestive libraries with a whole-body library was used to evaluate expression levels. All classes of digestive enzymes were highly expressed, with a predominance of cysteine and aspartic proteinases, the latter showing a significant expansion through gene duplication. Although no protein digestion is known to occur in the anterior midgut (AM), protease transcripts were found, suggesting secretion as pro-enzymes, being possibly activated in the posterior midgut (PM). As expected, genes related to cytoskeleton, protein synthesis apparatus, protein traffic, and secretion were abundantly transcribed. Despite the absence of a chitinous peritrophic membrane in hemipterans - which have instead a lipidic perimicrovillar membrane lining over midgut epithelia - several gut-specific peritrophin transcripts were found, suggesting that these proteins perform functions other than being a structural component of the peritrophic membrane. Among immunity-related transcripts, while lysozymes and lectins were the most highly expressed, several genes belonging to the Toll pathway - found at low levels in the gut of most insects - were identified, contrasting with a low abundance of transcripts from IMD and STAT pathways. Analysis of transcripts related to lipid metabolism indicates that lipids play multiple roles, being a major energy source, a substrate for perimicrovillar membrane formation, and a source for hydrocarbons possibly to produce the wax layer of the hindgut. Transcripts related to amino acid metabolism showed an unanticipated priority for degradation of tyrosine, phenylalanine, and tryptophan. Analysis of transcripts related to signaling pathways suggested a role for MAP kinases, GTPases, and LKBP1/AMP kinases related to control of cell shape and polarity, possibly in connection with regulation of cell survival, response of pathogens and nutrients. Together, our findings present a new view of the triatomine digestive apparatus and will help us understand trypanosome interaction and allow insights into hemipteran metabolic adaptations to a blood-based diet.
Metagenomic Analysis of Taxa Associated with Lutzomyia longipalpis, Vector of Visceral Leishmaniasis, Using an Unbiased High-Throughput Approach
Christina B. McCarthy ,Luis A. Diambra,Rolando V. Rivera Pomar
PLOS Neglected Tropical Diseases , 2011, DOI: 10.1371/journal.pntd.0001304
Abstract: Background Leishmaniasis is one of the most diverse and complex of all vector-borne diseases worldwide. It is caused by parasites of the genus Leishmania, obligate intramacrophage protists characterised by diversity and complexity. Its most severe form is visceral leishmaniasis (VL), a systemic disease that is fatal if left untreated. In Latin America VL is caused by Leishmania infantum chagasi and transmitted by Lutzomyia longipalpis. This phlebotomine sandfly is only found in the New World, from Mexico to Argentina. In South America, migration and urbanisation have largely contributed to the increase of VL as a public health problem. Moreover, the first VL outbreak was recently reported in Argentina, which has already caused 7 deaths and 83 reported cases. Methodology/Principal Findings An inventory of the microbiota associated with insect vectors, especially of wild specimens, would aid in the development of novel strategies for controlling insect vectors. Given the recent VL outbreak in Argentina and the compelling need to develop appropriate control strategies, this study focused on wild male and female Lu. longipalpis from an Argentine endemic (Posadas, Misiones) and a Brazilian non-endemic (Lapinha Cave, Minas Gerais) VL location. Previous studies on wild and laboratory reared female Lu. longipalpis have described gut bacteria using standard bacteriological methods. In this study, total RNA was extracted from the insects and submitted to high-throughput pyrosequencing. The analysis revealed the presence of sequences from bacteria, fungi, protist parasites, plants and metazoans. Conclusions/Significance This is the first time an unbiased and comprehensive metagenomic approach has been used to survey taxa associated with an infectious disease vector. The identification of gregarines suggested they are a possible efficient control method under natural conditions. Ongoing studies are determining the significance of the associated taxa found in this study in a greater number of adult male and female Lu. longipalpis samples from endemic and non-endemic locations. A particular emphasis is being given to those species involved in the biological control of this vector and to the etiologic agents of animal and plant diseases.
Caracteristicas de las personas que acuden a las consultas de demanda del centro de salud sin citación previa
Pomar,Carlos Isanta; Torres,Pilar Rivera; Iglesias,Marta Pedraja; Blasco,Natalia Giménez;
Revista Espa?ola de Salud Pública , 2000, DOI: 10.1590/S1135-57272000000300004
Abstract: background: waiting time to see a physician is considered to be an indicator of user satisfaction. non-emergency visits made without an appointment ahead of time result in longer waiting times for the patients who have appointments, resulting in the consequent insatisfaction thereof. the purpose of this study is aimed at conducting a quantitative assessment of this type of visits and at ascertaining the characteristics thereof for the purpose of putting measures into practice for the correction and rationalization thereof. methods: descriptive study. a record was made which would gather the characteristics of those patients seeing physicians without having made an appointment, such as age, gender and the characteristics related to the visit (reason, modality, working hours and whether made directly or indirectly). results: no appointment had been made ahead of time for 14.19% of all non-emergency patient-requested visits. based on the factorial analysis of multiple correlations, two visit profiles are identified, that is, the direct visits requested by young patients due to illness or red tape at the end of the physician?s morning hours, said young patients being present, and the indirect visits during the visits for which appointments have been made ahead of time by patients requesting prescriptions. conclusions: there are a large number of visits for which no appointment has been made ahead of time. measures must be taken for the purpose of channeling the use of the appointment organization system and of improving those situations involving a lack of accessibility for the end purpose of improving the degree of satisfaction of those using the public health care services.
Caracteristicas de las personas que acuden a las consultas de demanda del centro de salud sin citación previa
Pomar Carlos Isanta,Torres Pilar Rivera,Iglesias Marta Pedraja,Blasco Natalia Giménez
Revista Espa?ola de Salud Pública , 2000,
Abstract: FUNDAMENTO: El tiempo de espera para acceder a la consulta está considerado un indicador de satisfacción. Las visitas no urgentes, realizadas sin cita previa, provocan un incremento del tiempo de espera de los pacientes citados, con la consiguiente insatisfacción de los mismos. El objetivo del estudio persigue la valoración cuantitativa de este tipo de visitas y conocer las características de las mismas, para introducir las medidas destinadas a su corrección y racionalización. MéTODOS: Estudio descriptivo. Se realizó un registro que recogiera las características de los pacientes que originan las consultas sin cita previa, como la edad y el sexo y las relativas a la consulta: motivo, modalidad, jornada laboral y si era realizada de forma directa o indirecta. RESULTADOS: El 14,19% de consultas a demanda no urgentes son sin citación previa. Con el análisis factorial de correspondencias múltiple se identifican dos perfiles de consultas: las directas, solicitadas por pacientes jóvenes, por enfermedad o tareas burocráticas, al final de la consulta de la ma ana, estando ellos presentes, y las consultas indirectas, ocasionadas durante las consultas con cita previa por pacientes que solicitan recetas. CONCLUSIONES: Hay un elevado número de visitas sin cita previa. Son precisas medidas que puedan conducir a la utilización del sistema de organización de las consultas y a la mejora de aquellas situaciones que impliquen una falta de accesibilidad, con la finalidad última de mejorar la satisfacción de los usuarios de los servicios sanitarios públicos.
Asociación entre el perfil sensorial, el funcionamiento de la relación cuidador-ni?o y el desarrollo psicomotor a los tres a?os de edad
Castillejos-Zenteno, Liliana;Rivera-González, Rolando;
Salud mental , 2009,
Abstract: since the beginning of the last century there were some differences in child-related difficulties in regulation that could not be included in the categories of diagnosis were counted, so they fitted within the learning problems, coordination problems and sometimes until the epilepsy. decades later, each problem was subject of a separate diagnostic category, which favored the study of diseases, but fragmented the diagnosis for children who had a variety of symptoms that some of them were due to a single source. then the diagnoses increased in coordination disorder, attention deficit disorder with and without hyperactivity (adhd), the sensory integration dysfunction, language disorders, and so on. in order to complete the criteria of dsm-iv, in the case of children the zero to three/national center for clinical programs for infants developed a diagnostic classification for children from 0 to 3 years old (dc: o-3). the dc: 0-3, consists of five axes. the axis i refers to the primary diagnosis, and includes the regulatory disorders and developmental disorders that affect different systems. regulatory disorders are constitutional in nature, based on sensory problems, or sensorimotor processing, characterized by difficulties of the child to regulate their behavior, sensory, attention, motor and/or emotional, to organize positive affective states, warning or actions to calm down. the objective of the present research was to establish the association between the characteristics of the sensory profile, the parent-infant relationship and the psychomotor development of children. materials and methods to assess the level of development of children was used the conduct development profile, as revised (pcd-r). for the parent-infant relationship was used the parent-infant relationship global assessment scale (pir-gas). thus, to recognize a regulatory disorder it was used the sensory profile which assess the child's sensory processing and its impact on the daily lives of children.
Asociación entre el perfil sensorial, el funcionamiento de la relación cuidador-ni o y el desarrollo psicomotor a los tres a os de edad
Liliana Castillejos-Zenteno,Rolando Rivera-González
Salud mental , 2009,
Abstract: Con la intención de complementar los criterios del DSM-IV, en el caso de los ni os peque os, el Zero to Three/Centro Nacional para Programas Clínicos para Infantes, desarrolló la Clasificación Diagnóstica para los ni os de cero a tres a os (DC: O-3). El DC: 0-3, constó de cinco ejes. El eje I se refiere al diagnóstico primario, e incluyó los trastornos regulatorios y los trastornos del desarrollo que influyen en diferentes sistemas. Los trastornos regulatorios son de naturaleza constitucional y de maduración, basados en problemas sensoriales, sensoriomotores o de procesamiento; se caracterizan por dificultades que presenta el ni o para regular su comportamiento sensorial, atencional, motor y/o afectivo, así como para organizar estados afectivos positivos, de alerta o acciones para calmarse. El objetivo de la presente investigación fue establecer la asociación entre las características del perfil sensorial con el desarrollo psicomotor del ni o...
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