Sample records for PROTEINA UNICELULAR (single cell protein)
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2

UN MODELO DEL MECANISMO DE ENTRADA DE LOS ROTAVIRUS A LA CÉLULA HOSPEDERA/ A model for the mechanism of entry of rotaviruses into the host cell

Acosta L, Orlando; Calderón, Martha N; Moreno, Liz P; Guerrero, Carlos A
2009-04-01

Resumen en español Antecedentes. La infección rotaviral es causa principal de gastroenteritis aguda severa en niños menores de cinco años. La capa protéica externa de la partícula viral está implicada en las interacciones iniciales virus-superficie celular. El mecanismo rotaviral de unión y entrada a la célula parece ser un proceso de múltiples pasos donde las proteínas rotavirales VP4 y VP7 interaccionan con diferentes moléculas de la superficie celular. Objetivo. Proponer un me (mas) canismo de entrada de rotavirus a la célula que incorpore la actividad de la proteína disulfuro isomerasa (PDI). Material y métodos. Utilizando bases de datos electrónicas, se realizó una búsqueda de literatura original y de revisión publicada entre 1990 y 2009 sobre moléculas de la superficie rotaviral o celular participantes en el proceso de entrada del virus. El análisis de los resultados enfatizó las bases moleculares y celulares de las interacciones temporo-espaciales de las proteínas virales y las moléculas de unión/receptoras de la célula. Resultados. Se encontró fundamentos moleculares y celulares para incorporar la actividad de PDI a un mecanismo coherente de vías secuenciales o alternativas previas a la penetración viral. Se propone un mecanismo en que interaccionan las proteínas virales VP4, VP6 y VP7 con las moléculas de la superficie celular ácido siálico, integrinas, Hsc70 y PDI en un proceso endocítico caveola/“raft”-dependiente, caveolina/clatrina-independiente, dinamina-dependiente y sensible a depleción de colesterol. Conclusión. Se amplía el concepto de múltiples pasos en el proceso de entrada de rotavirus, donde la participación de PDI podría ser un blanco potencial de la acción de inhibidores de grupos tiol/disulfuro. Resumen en inglés Background. Rotavirus infection is the leading single cause of severe acute gastroenteritis in children under five years of age. The outermost layer of the triple-layered protein capsid of the non-enveloped virus particle has been involved in initial interactions between virus and host cell surface. The rotavirus mechanism for cell attachment and entry seems to be a multistep process in which outermost layer virus proteins VP4 and VP7 interact with different cell surface (mas) molecules. Objective. To propose a mechanism for rotavirus entry to the host cell incorporating the protein disulfide isomerase (PDI) activity. Materials and methods. A systematic search for original and review literature published from 1990 to 2009 on rotavirus and cell surface molecules participating in virus entry process was conducted through the use of electronic Databases. The analysis of the published results emphasized the molecular and cellular bases of time and space interactions between virus proteins and cell surface attachment and receptor molecules. Results. We found molecular and cellular bases for incorporating PDI within a coherent mechanism involving sequential or alternative paths previous to virus penetration. A mechanism is proposed in which virus proteins VP4, VP6 and VP7, and cell surface sialico acid, integrins, Hsc70, and PDI interact as part of a caveola/ raft-mediated endocytic process that is characterized by its caveolin and clathrin independence, dynamin dependence, and sensitivity to cholesterol depletion. Conclusions. The rotavirus entry mechanism appears to be a complex multistep process in which the path using PDI could be a potential target for antiviral agents reacting with thiol/disulfide groups.

Scientific Electronic Library Online (Spanish)

3

Tras la huella de las células madre/ On the track of stem cells

Hernández Ramírez, Porfirio; Dorticós Balea, Elvira
2010-08-01

Resumen en español En los últimos años ha surgido un gran interés en conocer la biodistribución de las células madre en el organismo después que son infundidas o inyectadas directamente en una parte del cuerpo. Para esto se han usado diferentes procederes, entre ellos, el marcaje de las células con diferentes fluorocromos, tales como la proteína con fluorescencia verde y la proteína con fluorescencia roja; o bien se les hace una transfección con plasmidos que codifican proteínas (mas) fluorescentes o se emplean sondas moleculares fluorescentes para la identificación de cromosomas. Recientemente se han introducido técnicas imagenológicas de avanzada no invasivas, entre las que tenemos la resonancia magnético nuclear, así como procederes basados en el marcaje con radionúclidos para la obtención de imágenes detectadas por tomografía por emisión de positrones (PET, del inglés positron emission tomography), o por tomografía computarizada por emisión de fotón único (SPECT, del inglés single- photon emission computed tomography). Resumen en inglés In past years there was an increasing interest by to know about the biodistribution of stem cells in organism after its perfusion or direct injection in a part of the body. Thus, we used different procedures including the cell labeling with distinct fluorochromes, such as the green fluorescence protein and the red fluorescence protein or a plasmid transfection codifying the fluorescent proteins of fluorescent molecular stents to identify the chromosomes. Recently non-inva (mas) sive leading imaging techniques have been introduced including nuclear magnetic resonance. As well as procedures based on radionuclide labeling to obtain the positron emission tomography (PET) images or by photon-emission computed tomography (SPECT).

Scientific Electronic Library Online (Spanish)

4

Transcriptomal profiling of site-specific Ras signals

Agudo-Ibáñez, Lorena; Núñez, Fátima; Calvo González, Fernando; Berenjeno, Inmaculada M.; Bustelo, Xosé R.; Crespo, Piero
2007-11-01

Digital.CSIC (Spain)

5

Three-dimensional model for the isolated recombinant influenza virus polymerase heterotrimer

Torreira, Eva; Schoehn, Guy; Fernández, Yolanda; Jorba, Núria; Ruigrok, Rob W. H.; Cusack, Stephen; Ortín, Juan; Llorca, Óscar
2007-05-21

Digital.CSIC (Spain)

6
7

The amino-terminal domain of the CCR2 chemokine receptor acts as coreceptor for HIV-1 infection

Frade, José M.R.; Llorente Gómez, María de las Mercedes; Mellado, Mario; Alcamí, José; Gutiérrez Ramos, José Carlos; Zaballos, Ángel; Real, Gustavo del; Martínez-Alonso, Carlos
1997-08-01

Digital.CSIC (Spain)

8

The Drosophila spn-D gene encodes a RAD51C-like protein that is required exclusively during meiosis

Abdu, Uri; González-Reyes, Acaimo; Ghabrial, Amin; Schüpbach, Trudi
2003-09-01

Digital.CSIC (Spain)

9

Targeted Disruption of Ras-Grf2 Shows Its Dispensability for Mouse Growth and Development

Esteban, Luis Miguel; Núñez, Alejandro; Santos de Dios, Eugenio; Fernández-Medarde, Alberto; Porteros, Ángel; Tessarollo, Lino
2002-04-01

Digital.CSIC (Spain)

10

TNFalpha-Polymorphismus bei Patienten mit Sepsis und Schilddrüsenkarzinomen

Rossbach, Christiane

Das Zytokin Tumornekrosefaktor a (TNFa) hat einen entscheidenden Anteil an der Entwicklung schwerer Komplikationen, wie septischer Schock und Multiorganversagen nach Entwicklung einer Sepsis. Eine Assoziation des TNF2-Allels mit einem erhöhten TNF a Spiegel und einer höheren Mortalitätsrate wurde i...

DRIVER (Spanish)

11

Structure of Epac2 in complex with a cyclic AMP analogue and RAP1B

Rehmann, Holger; Arias-Palomo, Ernesto; Hadders, Michael A.; Schwede, Frank; Llorca, Óscar; Bos, Johannes L.
2008-07-27

Digital.CSIC (Spain)

12

Specific interactions of chromatin with the nuclear envelope: positional determination within the nucleus in Drosophila melanogaster

Marshall, Wallace F.; Dernburg, Abby F.; Harmon, Brian; Agard, David A.; Sedat, John W.
1996-05-01

Digital.CSIC (Spain)

14

Rapid selection in modified BHK-21 cells of a foot-and-mouth disease virus variant showing alterations in cell tropism

Escarmis Homs, Cristina; Carrillo, Elisa C.; Ferrer, Marcela; García, Juan F.; López, Nora; Tami, Cecilia; Verdaguer, Nuria; Domingo, Esteban; Franze-Fernández, Maria T.
1998-01-01

Digital.CSIC (Spain)

15

RNase/Anti-RNase Activities of the Bacterial parD Toxin-Antitoxin System

Muñoz-Gómez, Ana J.; Lemonnier, Marc; Santos-Sierra, Sandra; Berzal-Herranz, Alfredo; Díaz-Orejas, Ramón
2005-05-01

Digital.CSIC (Spain)

16

Protein crystal quality in diffusive environments and its evaluation.

López-Jaramillo, F. J.; Otalora, Fermín; Gavira Gallardo, J. A.
2003-01-01

Digital.CSIC (Spain)

17

Producción de biomasa y calidad nutricional del estrato graminoide en un sistema silvopastoril dominado por samán (Samanea saman (Jacq) Merr)/ Biomass production and nutritive value of the grass stratum in a silvopastoral system dominated by saman (Samanea saman (Jacq) Merr)

Hernández, Manuel; Guenni, Orlando
2008-12-01

Resumen en español En la Estación Experimental La Antonia de la Universidad Central de Venezuela, se estudió el efecto de la sombra del samán (Samanea saman) sobre la producción forrajera. El experimento se llevó a cabo en dos potreros con distintas densidades de samán. El primero (PI) poseía un árbol y las especies dominantes en el estrato herbáceo fueron: Digitaria swazilandensis (Ds) y Urochloa arrecta (Ua), mientras que el segundo (PII) poseía un grupo de cuatro árboles con U (mas) a y Urochloa mutica (Um). Se determinó la producción de biomasa, el contenido nutricional y algunos caracteres morfológicos del pasto durante 6 semanas de rebrote a lo largo de tres períodos: transición lluvia-sequía 2003 (P1), transición sequía-lluvia 2004 (P2) y transición lluvia-sequía 2004 (P3). En PI los porcentajes de densidad de flujo fotónico (DFF) bajo el dosel fueron 38, 82 y 41% a lo largo de P1, P2 y P3, respectivamente; mientras que para PII fueron 33, 48 y 26%, respectivamente. La disminución en DFF produjo un aumento del área foliar específica en todas las gramíneas. En P1 y P3 el índice de área foliar aumentó en Ds y Ua y disminuyó en Um. Ds y Ua mostraron una alta plasticidad fenotípica a la reducción de luz, mientras que Um la tuvo solo en P2. En general, la reducción en la humedad edáfica durante P2 afectó el rendimiento en materia seca a pleno sol. En este período, una DFF de 48-82% pareció tener un efecto compensatorio sobre la producción forrajera, debido a que la humedad del suelo mejoró en algunos casos. Durante P1, el contenido proteico del forraje se incrementó bajo la sombra, mientras que los valores de P, contenido de pared celular y degradabilidad de la materia seca no fueron tan modificados. La eficiencia de uso de la radiación (EUR) incrementó con la sombra, en rangos de 0,7 a 1,5 g/MJ y 1,4 a 2,4 g/MJ para Ds y Ua, respectivamente. Estos incrementos en la EUR pudieran contribuir significativamente a mejorar el grado de ajuste a la sombra en las especies mencionadas. Resumen en inglés A study was carried out at La Antonia experimental station of Universidad Central de Venezuela to evaluate the effect of shade of saman (Samanea saman) on pasture production. The experiment was performed on two plots with different tree densities. The first plot (PI) had one saman tree and the herbaceous stratum was composed by Digitaria swazilandensis (Ds) and Urochloa arrecta (Ua). The second plot (PII) had four trees plus Ua and Urochloa mutica (Um). Biomass production (mas) , forage nutrient concentration and some plant morphological characters were measured during 6 consecutive regrowth weeks along three times of the year: 1) wet-dry period 2003 (P1), 2) dry-wet period 2004 (P2), and 3) wet-dry period 2004 (P3). At PI the percentages of photon flux density (PFD) beneath the single tree canopy were 38, 82, and 41% along P1, P2, and P3, respectively, whereas the corresponding values for PII were 33, 48, and 26%. Specific leaf area increased in all grasses as PFD decreased. At P1 and P3, leaf area index increased in Ds and Ua, and diminished in Um. Ds y Ua showed a high phenotypic plasticity to low PFD intensities, while Um had a greater response at P2. In general, the reduction in soil water content along P2 decreased dry matter yield at 100% light. In this case, a PFD of 48 to 82% appeared to have a compensatory effect on the pasture, since soil humidity was increased in some cases, improving total forage biomass under shade. During P1 the forage protein content of almost all grasses increased under shade when compared to full light, whereas phosphorus values, cell wall content and the dry matter degradability did not show any important variation under shade. Pasture radiation use efficiency (RUE) increased from full light to shade within the ranges 0.7 to 1.5 g/MJ and 1.4 to 2.4 g/MJ for Ds and Ua, respectively. These RUE increments may have a significant effect on improving grass responses to decreased light under tree cover.

Scientific Electronic Library Online (Spanish)

18

Phylogenetic conservation of the regulatory and functional properties of the Vav oncoprotein family

Couceiro, José R.; Martín-Bermudo, María D.; Bustelo, Xosé R.
2005-08-15

Digital.CSIC (Spain)

19

Perfil de aminoácidos de la proteína unicelular de kluyveromyces marxianus var. Marxianus./ Amino acids profile of the single cell protein from kluyveromyces marxianus var. Marxianus./ Perfil de aminoácidos da proteína unicelular de kluyveromyces marxianus var. Marxianus.

Páez, Gisela; Jiménez, Eduardo; Mármol, Zulay; Ferrer, José; Sulbarán, Betzabé; Ojeda, Graciela; Araujo, Karelen; Rincón, Marisela
2008-04-01

Resumen en portugués Estudou-se o perfil de aminoácidos da proteína unicelular (PUC) da levedura Kluyveromyces marxianus var. marxianus (ATCC 8554) utilizando lactossoro como substrato. Os bio-processos se realizaram por triplicado a pH 5,0; 30°C e 200rpm durante 12h em um bioreator Bioflo® 4000. Caracterizou-se a umidade, lipídeos e proteína crua da biomassa obtida. Para a análise do perfil de aminoácidos se utilizou um cromatógrafo líquido de alta resolução. A derivatização do (mas) s aminoácidos livres se realizou com fenilisotiocianato. Os resultados indicaram que o conteúdo de proteína crua em K. marxianus é de 42,19%. O conteúdo de lisina (5,47 ±3,0%) e de treonina (15,21 ±2,6%) nesta proteína são maiores que na proteína da farinha de trigo. O aminoácido encontrado em maior quantidade foi o ácido glutâmico, característico de organismos unicelulares, enquanto que a metionina foi o aminoácido obtido em menor proporção. O perfil de aminoácidos mostra uma distribuição equilibrada do conteúdo destes na proteína unicelular de K. marxianus em comparação aos padrões de referencia internacionais da FAO, o que sugere o uso potencial desta proteína unicelular como fonte protéica. Resumen en español Se estudió el perfil de aminoácidos de la proteína unicelular (PUC) de la levadura Kluyveromyces marxianus var. marxianus (ATCC 8554) utilizando lactosuero como sustrato. Los bioprocesos se llevaron a cabo por triplicado a pH 5,0; 30°C y 200rpm durante 12h en un biorreactor Bioflo® 4000. Se caracterizó la humedad, lípidos y proteína cruda de la biomasa obtenida. Para el análisis del perfil de aminoácidos se utilizó un cromatógrafo líquido de alta resolución. (mas) La derivatización de los aminoácidos libres se realizó con fenilisotiocianato. Los resultados indicaron que el contenido de proteína cruda en K. marxianus es de 42,19%. El contenido de lisina (5,47 ±3,0%) y de treonina (15,21 ±2,6%) en esta proteína son mayores que en la proteína de la harina de trigo. El aminoácido encontrado en mayor cantidad es el ácido glutámico, característico de organismos unicelulares, mientras que la metionina es el aminoácido obtenido en menor proporción. El perfil de aminoácidos muestra una distribución equilibrada del contenido de éstos en la proteína unicelular de K. marxianus en comparación a los patrones de referencia internacionales de la FAO, lo que sugiere el uso potencial de esta proteína unicelular como fuente proteica. Resumen en inglés The amino acids profile of the single cell protein from Kluyveromyces marxianus var. marxianus (ATCC 8554) growing in whey as substrate was studied. The bio-processes were carried out by triplicate to pH 5.0, 30°C and 200rpm during 12h in a Bioflo® 4000 biorreactor. Humidity, lipids and crude protein content of the biomass obtained were measured. For the analysis of the profile of amino acids a liquid chromatograph of high resolution was used. The derivatization of the (mas) free amino acids was carried out with phenilisotiocianate. Results indicated a crude protein content in K. marxianus of 42.19%. The content of lysin (5.47 ±3.0%) and threonin (15.21 ± 2.6%) in this protein are higher than in wheat flour protein. The amino acid found in the highest amount is glutamic acid, characteristic of unicellular organisms, whereas the methionin is the amino acid obtained in smaller amount. The profile of amino acids obtained shows a reasonable distribution of the content of these in the unicellular protein of K. marxianus in comparison to the international reference patterns of FAO, which suggests the potential use of this unicellular protein like protein source.

Scientific Electronic Library Online (Spanish)

20

On the remarkable mechanostability of scaffoldins and the mechanical clamp motif

Valbuena Jiménez, Alejandro; Oroz, Javier; Hervás, Rubén; Vera Gómez, Andrés Manuel; Rodríguez, David; Menéndez, Margarita; Sulkowska, Joanna I.; Cieplak, Marek; Carrión-Vázquez, Mariano Sixto
2009-07-31

Digital.CSIC (Spain)

21

Nitrate reductase isozymes in Bradyrhizobium sp. (Lupinus) bacteroids: localisation, biochemical and kinetic characteristics

Chamber Pérez, Manuel Ángel; Camacho, M. Encarnación; Burgos, R.; Lucas, M. Mercedes; Fernández Pascual, Mercedes; Manclús, J. J.; Felipe, Mª Rosario de
2002-01-01

Digital.CSIC (Spain)

24

Molecular analysis of a phylogenetically conserved carrot gene: developmental and environmental regulation

William, S. Seffens; Almoguera, Concepción; Wilde, H.D.; Von der Haar, Raymond A.; Thomas, T.L.
1990-01-01

Digital.CSIC (Spain)

25

Microarray-based identification of antigenic variants of foot-and-mouth disease virus: a bioinformatics quality assessment

Martín, Verónica; Perales, Celia; Abia, David; Ortíz, Ángel R.; Domingo, Esteban; Briones, Carlos
2006-05-18

Digital.CSIC (Spain)

26

Marcadores genéticos en hipertensión esencial/ Genetic markers in essential hypertension

PASSALACQUA, CRISTÓBAL; CASTILLO TAUCHER, SILVIA
2010-06-01

Resumen en inglés Essential hypertension (HTA) is a multifactorial disease and in Chile, its prevalence is 33.7%. There is a genetic predisposition to develop hypertension, whose magnitude is approximately 30 to 50%. At present, some factors are known to increase the risk for cardiovascular disease, but widely accepted biomarkers for screening are missing. The frst studies that looked for candidate genes have focused on the reninangiotensin - aldosterone, aducina, adrenoreceptors ß, G pro (mas) tein subunits, G protein signaling regulators, kinases associated with G proteins and Rho kinases. Studies of DNA sequencing, search for polymorphisms and variants through single nucleotide polymorphisms, have been used to seek partnerships with complex or multifactorial diseases, like HTA. Examples of these are: components of collagen proteins, genes related to cell myocardial proteins belonging to cytochrome P450 and growth factors, among others. It is still unlikely to count in a near future with a universal marker. Most probably, a series of markers that confer susceptibility to a specifc individual will have to be used in prevention programs or personalized therapy

Scientific Electronic Library Online (Spanish)

27

Maintenance of Undifferentiated State and Self-Renewal of Embryonic Neural Stem Cells by Polycomb Protein Ring1B

Román-Trufero, Mónica; Méndez-Gómez, Héctor R.; Pérez, Claudia; Hijikata, Atsushi; Fujimura, Yu-ichi; Endo, Takaho; Koseki, Haruhiko; Vicario-Abejón, Carlos; Vidal, Miguel
2009-04-02

Digital.CSIC (Spain)

28

Listeria monocytogenes en alimentos: ¿son todos los aislamientos igual de virulentos?/ Foodborne Listeria monocytogenes: are all the isolates equally virulent?

López, V.; Suárez, M.; Chico-Calero, I.; Navas, J.; Martínez-Suárez, J. V.
2006-12-01

Resumen en español Listeria monocytogenes es un patógeno humano que se transmite a través de los alimentos y que causa infecciones graves, con una alta tasa de mortalidad. A pesar de la ubicuidad del microorganismo, la tasa real de la enfermedad es bastante baja y se asocia casi siempre a condiciones predisponentes. Tradicionalmente se consideraba que los aislamientos presentes en los alimentos y en el ambiente tenían la misma capacidad patogénica que los aislamientos de origen clínico (mas) . Pero el análisis de mutaciones en los genes de determinados factores de virulencia (internalina, hemolisina, fosfolipasas, proteína de superficie ActA y proteína reguladora PrfA), los estudios cuantitativos realizados con cultivos celulares y la genética de poblaciones, están replanteando la discusión sobre la variabilidad de la virulencia de L. monocytogenes. A pesar de todos estos avances, no existe un único marcador que permita comprobar la virulencia de los aislamientos naturales de esta especie. Probablemente en el futuro, la combinación de diferentes marcadores moleculares permitirá detectar los alimentos contaminados sólo por los clones virulentos de L. monocytogenes, con lo que se mejorará la prevención de la listeriosis humana transmitida por alimentos. Resumen en inglés Listeria monocytogenes is a foodborne human pathogen responsible for invasive infections presenting overall a high mortality. Despite the ubiquity of the microorganism, the actual disease rate is quite low and the disease is most often associated with an underlying predisposition. Foodborne and environmental isolates were traditionally considered of similar pathogenicity compared to clinical isolates. But the analysis of mutations in the genes encoding specific virulence (mas) factors (internalin, hemolysin, phospholipases, surface protein ActA and regulator protein PrfA), quantitative studies with cell cultures and population genetics have raised considerable concerns about virulence differences among L. monocytogenes strains. Despite this great step forward, there is not a single marker available to test the virulence of field isolates of this species. In the future, the combination of different molecular markers will probably allow the screening of food contamination by only the virulent clones of L. monocytogenes, thus improving the prevention of foodborne human listeriosis.

Scientific Electronic Library Online (Spanish)

29

La epigenética y los estudios en gemelos en el campo de la psiquiatría/ Epigenetics and twin studies in psychiatric domains

González Ramírez, Adriana Estrella; Díaz Martínez, Alejandro; Díaz-Anzaldúa, Adriana
2008-06-01

Resumen en español La secuencia de ADN genómico que caracteriza a nuestra especie constituye la piedra fundamental de la vida humana; parte de ella se refleja en la secuencia del ARN y a través de éste se dicta la información necesaria para que nuestras células produzcan proteínas. La genética contribuye de manera importante a los avances en el campo médico. Los descubrimientos genéticos han permitido desarrollar estrategias para modificar, prevenir y proponer nuevas terapias para (mas) diversas enfermedades. En el siglo XIX, Gregor Johann Mendel desarrolló un modelo teórico capaz de predecir la naturaleza y propiedades de los mecanismos de la herencia, que sigue siendo indispensable para explicar la base de la herencia humana. Otro suceso determinante en la historia de la Medicina se dio a conocer casi nueve décadas después cuando James Watson y Francis Crick describieron su modelo estructural para el ADN. Posteriormente se introdujeron la clonación posicional y la reacción en cadena de la polimerasa; más recientemente se publicó cerca del 99% de la secuencia del genoma humano. El período actual se conoce como la era post-genómica, ya que además de descifrar genomas completos, los investigadores pretenden, entre otras cosas, esclarecer los mecanismos que influyen en la activación e inactivación de los genes, lo cual en parte involucra un nivel epigenético. En las ciencias médicas los gemelos constituyen un grupo idóneo para abordar el estudio de las enfermedades hereditarias. En este tipo de padecimientos suelen observarse similitudes entre parientes, en especial si se trata de gemelos monocigóticos. Sin embargo, aun en este tipo de hermanos se detectan diferencias importantes. Parámetros como los grados de concordancia y porcentajes de heredabilidad han puesto de manifiesto que un gemelo monocigótico puede presentar trastornos hereditarios que su co-gemelo nunca tendrá. La epigenética es el estudio de los cambios en la función de los genes que no afectan la secuencia del ADN, por modificaciones que tienen lugar principalmente en las citosinas de éste y en las histonas de la cromatina. Se ha determinado que las modificaciones epigenéticas son mucho más frecuentes que aquellas que modifican la secuencia del ADN, por lo que constituyen uno de los fundamentos de la diversidad biológica, muestran la manera en que el ambiente puede modular la expresión genética y contribuyen así a nuestro fenotipo. Esta revisión reúne datos sobre la posible relevancia de la epigenética en el estudio de los trastornos mentales y como posible explicación parcial de las diferencias observadas entre gemelos >. Un conocimiento más profundo de los patrones epigenéticos podría contribuir a identificar factores de riesgo para estos trastornos. Resumen en inglés The sequence of the human genome integrates the keystone of our life. Part of it is transcribed to RNA, which in turn provides the information required by our cells to produce proteins. Discoveries in the genetics field have been essential to medicine and have been used to develop strategies to modify, prevent and propose new therapeutic approaches for human diseases. In the 19th Century, Gregor Johann Mendel developed a theoretical model which was able to predict in an a (mas) ccurate way hereditary mechanisms; indeed, his laws still explain the basis of human inheritance. Almost ninety years later, James Watson and Francis Crick announced their double-helix model of the DNA molecule. Then, positional cloning and the polymerase chain reaction (PCR) were introduced; more recently, almost 99% of the sequence of our genome was made public. The current period of time is known as the post-genomic era, due to the fact that researchers are not only obtaining the complete sequences of thousands of genomes, but are also searching for clues that may help understand the mechanisms that affect gene activation and deactivation, in which epigenetic factors are also involved. In medical domains, twins constitute a suitable group to study inherited disorders. Dizygotic or fraternal twins are produced by different egg and sperm cells, and even when these two fertilization events occur simultaneously, dizygotic twins share approximately the same percentage of genetic material than any pair of siblings, that is, around 50%. Some authors have suggested that the tendency for spontaneous dizygotic twinning could be attributed to a double ovulation which is genetically determined in an autosomal dominant manner. Monozygotic, as opposed to dizygotic twins, are produced by a single zygote whose cells are dissociated and originate two independent organisms; approximately a third of monozygotic twins are separated before the 5th day after fertilization, and the rest between the 5th and the 15th day. Most monozygotic twins are very similar; nevertheless, some few exceptions prove that in fact they actually do not have to be identical. Relatives of a person with a mental disorder tend to share traits associated with this disease, especially if the patient and the relative are monozygotic twins. However, important differences may be detected even between each pair of identical twins. Parameters such as concordance and heritability have shown that a monozygotic twin can develop an inherited disorder while his or her co-twin will always be disease-free. In addition to differences in susceptibility to inherited diseases, this kind of twins can display dissimilarities in somatic cell mutations (more overtly noticeable when ageing), their set of antibodies and T cell receptors, their number of mitochondrial DNA molecules, and chromosome X inactivation patterns in women, all of which are the main subject of many ongoing studies. A recent report shows that from 160 monozygotic twin pairs who were 3 to 74 years old, epigenetic patterns were identical early in life, but differences were more obvious at older ages, especially if twins were raised apart or if they had different medical history. Medical conditions, but also environmental factors such as pregnancy tobacco exposure, physical activity, and diet could contribute to differences in epigenetic patterns. It has been shown that epigenetic modifications (or epi-mutations) are more frequent than the ones that modify DNA sequence, so they are part of the fundamental causes of biological diversity, and they show how environment can modulate gene expression and contribute to our phenotype. Even when twin studies are sometimes considered purely genetic, they also give information about the influence of environmental factors. However, it is important to consider with caution the results from this type of studies. Heritability estimates are not unchangeable facts. They depend on the sample being analyzed, the genes involved in the specific sample, the characteristics of the environmental factors which members of this group were exposed to, and the precise moment the study was done. Epigenetics refers to changes that do not alter the DNA sequence but affect gene function due to chemical modifications which mainly occur in DNA cytosines and in chromatin-related histones. Epigenetic processes are covalent modifications which include the addition of functional groups (methyl, acetyl, phosphate, etc.) or proteins (ubiquitin, SUMO, etc.) to the DNA molecule or to associated proteins. These modifications contribute to the activation or inhibition of transcription, which leads to changes in messenger ARN expression that can ultimately influence the onset of disease. Pseudogenes are still being excluded while new genes are being confirmed in our genome sequence, but the current estimates indicate that each one of our nucleated cells contains almost 22000 genes (excluding mitochondrial DNA) which encode for polypeptides and more than 4,000 whose final product is RNA. Gene expression is partially controlled by DNA coiling around globular proteins called histones, which constitute a structure known as chromatin, a DNA-protein complex that represents the packaging of 3.25 billion base pairs of our genetic information. Physical and chemical chromatin modifications can also affect gene expression by changing DNA-protein interactions; in general terms, genes are inhibited when chromatin is packed and they are active when it is free. These dynamic states are controlled by epigenetic reversible modifications on DNA methylation or by changes in histones. It has been shown that subtle epigenetic differences between any two human beings are associated with dissimilar final chromatin remodeling, as well as expression/repression of genes.

Scientific Electronic Library Online (Spanish)

30

La dicotomía de los virus polioma: ¿Infección lítica o inducción de neoplasias?/ The paradox of polyomaviruses Lytic infection or tumor induction?

Sanjuan, Norberto A.
2004-02-01

Resumen en español Los virus Polioma murinos provocan infecciones líticas en cultivos de células de ratón y transforman in vitro células de rata a través de la interacción de su oncogén mT con diversos reguladores celulares. Luego de su inoculación en ratones neonatos inducen neoplasias epiteliales y mesenquimáticas. Se ha propuesto que las cepas de polioma más oncogénicas son aquellas que previamente replican más en el ratón. Sin embargo, a nivel de una sola célula la infecci (mas) ón lítica y la transformación deberían ser mutuamente excluyentes. En cada neoplasia han sido descriptos 3 tipos celulares según expresen el DNA viral solo o concomitantemente con la proteína mayor de la cápside VP1, o que no contengan DNA viral ni VP-1. En nuestro laboratorio detectamos la existencia de un cuarto tipo celular en las neoplasias, en el que se expresa la totalidad del genoma viral pero no ocurre el ensamblaje, probablemente por alteraciones en la fosforilación de VP-1. Se discuten los mecanismos de migración intracelular de Polioma, la diseminación en el ratón y los factores que podrían estar involucrados en la inducción de neoplasias o en la infección lítica inducidas por el virus. Resumen en inglés Murine polyomaviruses can produce lytic infections in mouse cell cultures or transform in vitro rat fibroblasts through a complex interaction with key cellular regulators. After infection of newborn mice, some strains of polyomavirus induce epithelial and mesenchymal tumors. It has been described that there is a direct relationship between viral dissemination in the mouse and tumor induction. However, at a single cell level lytic infection and transformation would not be (mas) able to coexist. The existence of 3 distinct cell populations in polyoma-induced tumors, classified according to the presence or absence of viral DNA and viral capsid protein VP-1 have been described. We have reported a fourth type of cell in the neoplasms, that can express the early and the late viral genes but do not allow virus assembly, probably due to underphosphorylation of VP-1. The mechanisms of polyoma intracellular migration and dissemination in the mouse are discussed, related to the virus’ ability of tumor induction.

Scientific Electronic Library Online (Spanish)

31

Infectious Bursal Disease Virus: Ribonucleoprotein Complexes of a Double-Stranded RNA Virus

Luque Buzo, Daniel; Saugar, Irene; Rejas, María Teresa; Carrascosa, José L.; Rodríguez Aguirre, José F.; Castón, José R.
2009-02-27

Digital.CSIC (Spain)

33

Improvement of SCP production and BOD removal of whey with mixed yeast culture

Moeini, Hassan; Nahvi, Iraj; Tavassoli, Manoochehr
2004-12-01

Resumen en inglés This research emphasizes on single cell protein (SCP) production and Biochemical Oxygen Demand (BOD) removal from whey with mixed yeast culture. For this purpose, 11 yeast strains were isolated from dairy products (M1-M11) and the strains were identified by morphological and physiological properties. These yeast strains were tested for their ability to reduce the BOD and to produce SCP from whey. Among these strains, K. lactis (M2) had the most SCP production from whey wi (mas) th the yield of 11.79 g/l. Ammonium sulphate as nitrogen source had an increasing effect on biomass yield. The mixed culture of the isolated yeast strains with Saccharomyces cerevisiae was used in order to increase the biomass yield and BOD removal. The highest biomass yield (22.38 g/l) and reduction of initial BOD from 30000 to 3450 mg/l were obtained with the mixed culture of K. lactis (M2) and S. cerevisiae

Scientific Electronic Library Online (Spanish)

34

Implication of the C terminus of the Prunus necrotic ringspot virus movement

Aparicio Herrero, Frederic; Pallás, Vicente; Sánchez-Navarro, J. A.
2010-03-10

Digital.CSIC (Spain)

35

Immunohistochemical profile of canalicular adenoma of the upper lip: a case report

Pereira, Michele Conceição; Costa Pereira, Alessandro Antônio; Costa Hanemann, João Adolfo
2007-01-01

Resumen en inglés Canalicular adenoma is an uncommon benign salivary gland neoplasm that has a marked predilection for occurrence in the upper lip. It is composed of columnar cells arranged in branching and interconnecting cords of single or double cell thick rows. This tumor has an excellent prognosis after conservative surgical treatment in all locations. In the present report we describe, using immunohistochemistry, the expression of cytokeratins (CK), S-100 protein and EMA in a canalic (mas) ular adenoma that arose in the upper lip of a 55-year-old female. Cells of the canalicular adenoma showed an immunohistochemical profile that indicates an excretory duct origin: most of these cells positively expressed AE1/AE3 cytokeratins and S100 protein. A comparison of the immunohistochemical features of canalicular adenoma with other salivary gland neoplasms that share similar histological features is discussed.

Scientific Electronic Library Online (Spanish)

36

Head-to-head comparison on the immunogenicity of two HIV/AIDS vaccine candidates based on the attenuated poxvirus strains MVA and NYVAC co-expressing in a single locus the HIV-1(BX08) gp120 and HIV-1(IIIB) Gag-Pol-Nef proteins of clade B

Gómez, Carmen E.; Nájera García, José Luis; Pérez Jiménez, Eva; Jiménez, Victoria; Wagner, Ralf; Graf, Marcus; Frachette, Marie-Joelle; Liljeström, Peter; Pantaleo, Giuseppe; Esteban, Mariano
2006-10-16

Digital.CSIC (Spain)

38

Functional N-methyl-D-aspartate receptors in clonal rat phaeochromocytoma cells

Casado, Mariano; López-Guajardo, Ana; Mellström, Britt; Naranjo, José Ramón; Lerma Gómez, Juan
1996-01-15

Digital.CSIC (Spain)

39

Fluidization of Membrane Lipids Enhances the Tolerance of Saccharomyces cerevisiae to Freezing and Salt Stress

Rodríguez Vargas, Sonia; Sánchez-García, Alicia; Martínez-Rivas, Jose Manuel; Prieto Alamán, José Antonio; Rández Gil, Francisca
2007-01-01

Digital.CSIC (Spain)

40

Evolutionary history of Na,K-ATPases and their osmoregulatory role

Sáez, Alberto G.; Lozano, Encarnación; Zaldívar-Riverón, Alejandro
2009-02-13

Digital.CSIC (Spain)

41

Evaluation of candidate reference genes for QPCR during ontogenesis and of immune-relevant tissues of European seabass (Dicentrarchus labrax)

Mitter, Karin; Kotoulas, Georgios; Magoulas, Antonios; Mulero, Victor; Sepulcre, Pilar; Figueras, Antonio; Novoa, Beatriz; Sarropoulou, Elena
2009-05-04

Digital.CSIC (Spain)

43

Energetics and Geometry of FtsZ Polymers: Nucleated Self-Assembly of Single Protofilaments

Huecas, Sonia; Llorca, Óscar; Boskovic, Jasminka; Martín-Benito, Jaime; Valpuesta, José M.; Andreu, José Manuel

11 pages, 5 figures.-- PMID: 18024502 [PubMed].-- Data Supplement available (6 pages, 10 figures). | Essential cell division protein FtsZ is an assembling GTPase which directs the cytokinetic ring formation in dividing bacterial cells. FtsZ shares the structural fold of eukaryotic tubulin and assemb...

DRIVER (Spanish)

44

Energetics and Geometry of FtsZ Polymers: Nucleated Self-Assembly of Single Protofilaments

Huecas, Sonia; Llorca, Óscar; Boskovic, Jasminka; Martín-Benito, Jaime; Valpuesta, José M.; Andreu, José Manuel
2008-03-05

Digital.CSIC (Spain)

46

Effects of oxidative and nitrosative stress on Tetrahymena pyriformis glyceraldehydes-3-phosphate dehydrogenase

Fourrat, Latifa; Iddar, Abdelghani; Valverde, Federico; Serrano, Aurelio; Soukri, Abdelaziz
2007-07-02

Digital.CSIC (Spain)

47

Efecto del lipopolisacárido en cultivos de células dendríticas humanas y su inhibición por la polimixina B/ Effect of lipopolysaccharides on human dentritic cell cultures and its inhibition by polymyxin B

Cuéllar, Adriana; Fonseca, Ángela; Gómez, Alberto
2004-12-01

Resumen en español Algunos estímulos de maduración utilizados en cultivos de células dendríticas, como las proteínas recombinantes obtenidas en sistemas bacterianos o los extractos proteicos de ectoparásitos, contienen lipopolisacáridos (LPS) y su presencia afecta el comportamiento de las células dendríticas en cultivo. En este trabajo se evaluó el efecto del LPS en un sistema de cultivo de células dendríticas humanas y la actividad de la polimixina B como inhibidor del efecto d (mas) el LPS. Para esto, los monocitos obtenidos a partir de sangre periférica humana se diferenciaron a células dendríticas con IL-4 y GM-CSF y como estímulo de maduración se utilizó LPS o PGE2/FNTá. La expresión de marcadores y la secreción de citocinas se evaluaron por citometría de flujo. Los resultados mostraron que la preexposición a endotoxina disminuyó la expresión de CD83, inhibió la secreción de IL-12p70, FNTá e IL-10 y disminuyó la secreción de IL-6 en células dendríticas. Además, la utilización de 10 mg/ml de polimixina B fue efectiva en la inhibición de la actividad de 1 mg/ml de LPS y la máxima concentración de polimixina B que no afectó la morfología de las células fue de 50 mg/ml. En conclusión, la polimixina B es efectiva para inhibir la actividad del LPS en los cultivos de células dendríticas. Resumen en inglés Dendritic cells have been described as effective antigen presenting cells. Human dentritic cells are highly susceptible to lipopolysaccharide (LPS) tolerance, consisting of a differential deactivation state in which some cellular functions are impaired. LPS tolerance can be experimentally induced in vitro, in which the presence of LPS strongly affects the behavior of cultured dendritic cells. Recombinant proteins obtained from bacterial systems or protein extracts of ecto (mas) parasites containing LPS can be used as stimuli to enhance maturation processes in these cells. The present study evaluated the effect of LPS in human dendritic cell cultures, and the activity of polymyxin B as an inhibitor of the LPS effect. Dendritic cells were obtained from peripheral blood monocytes in the presence of IL-4 and GM-CSF, followed by exposure with LPS and PGE2/TNFá. Surface markers and cytokine levels were evaluated by flow cytometry. The dendritic cells pre-exposed to single doses of endotoxin demonstrated a reduced capacity to mature, reduced CD83 expression, inhibited secretion of IL-12, TNFá, IL-10 and diminished secretion of IL-6. Furthermore, polymyxin B at 10 mg/ml inhibits LPS activity at 1 mg/ml. The maximum polymyxin B concentration with no effect on cellular morphology was 50 mg/ml. Consequently, polymyxin B was determined to be an effective LPS inhibitor in dendritic cell cultures.

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53

Cortical interneurons: from Cajal to 2001

De Felipe-Oroquieta, Javier
2002-01-01

Digital.CSIC (Spain)

54

Computational approaches to study transcriptional regulation in the human genome

Luscombe, Nicholas M.; Gómez Puertas, Paulino; Vaquerizas Erdocia, Juan Manuel
2008-01-01

Digital.CSIC (Spain)

55

Comparison of DNA binding across protein superfamilies

Contreras-Moreira, Bruno; Sancho Sanz, Javier; Espinosa Angarica, Vladimir
2009-01-01

Digital.CSIC (Spain)

56

Comparative analysis of the pathogenic mechanisms associated with the G8363A and A8296G mutations in the mitochondrial tRNA(Lys) gene

Bornstein, Belén; Mas Gutiérrez, José Antonio; Patrono, Clarice; Fernández-Moreno, Miguel Ángel; Gónzalez-Vioque, Emiliano; Campos, Yolanda; Carrozzo, Rosalba; Martín, Miguel Ángel; Hoyo, Pilar del; Santorelli, Filippo M.; Arenas, Joaquín; Garesse, Rafael
2005-05-01

Digital.CSIC (Spain)

57

Cinética de la hidrólisis ácida de bagacillo de caña de azúcar/ Kinetics of the acid hydrolysis of sugar cane bagasse pith

Ferrer, J. R.; Páez, G.; Arenas de Moreno, L.; Chandler, C.; Mármol, Z.; Sandoval, L.
2002-01-01

Resumen en español Se estudió la producción de azúcares reductores (AR) a partir de la hidrólisis ácida del bagacillo de caña, ya que ellos representan una fuente fundamental de carbohidratos para procesos biotecnológicos, orientados a la producción de proteína unicelular y compuestos orgánicos. El bagacillo tratado (BT) y no-tratado (BNT) con inmersión en agua (TA) a temperatura ambiente, se hidrolizó, mediante ebullición a reflujo, con diferentes concentraciones (C) de ácido (mas) sulfúrico diluido (2%, 4%, 6% y 8 % v/v) a diferentes tiempos de reacción (TR) (4, 8 y 12 h.), en una relación líquido: sólido de 30/1. La determinación cuantitativa de AR se realizó por espectrofotometría UV-Vis por el método del ácido 3,5 dinitrosalisílico (DNS). El experimento involucró un diseño totalmente al azar con un arreglo factorial 2 x 3 x 4 con tres repeticiones. Se realizó un análisis de varianza con el paquete estadístico "Statistical Analysis System" (SAS); se utilizó la prueba HSD de Tukey para los efectos principales y el método de mínimos cuadrados para las interacciones. Los resultados demostraron que todos los factores en estudio y sus interacciones, excepto la interacción (TA x TR), afectaron significativamente (P Resumen en inglés The production of reductive sugars (AR) through acid hydrolysis of sugar cane bagasse was performed in order to study reducing sugar production, because they represent a basic carbohydrate source in biotechnological processes for single cell protein and organic compound production. The study involved hydrolysis of treated (BT) and non-treated (BNT) bagasse pith immersed in water at environmental temperatures through reflux boiling with different concentrations of diluted (mas) sulphuric acid (2%, 4%, 6%, 8%, v/v) with different reaction times (TR) (4, 8 and 12 hrs) in a liquid/solid ratio of 30/1. Reducing sugars concentrations (AR) were determined by UV-Vis spectrum-photometry using the 3.5 dinitrosalisilic acid method. The experiment utilized a factorial arrangement (2 x 3 x 4) in a completely random design with three replicates. Variance analysis was performed with Statistical Analysis System (SAS) using the Tukey HDS method for main effects and the minimum squares method for interactions . The results showed that all the factors significantly affected the AR concentration (P

Scientific Electronic Library Online (Spanish)

58

Changes in photosynthetic electron transfer and state transitions in an herbicide-resistant D1 mutant from soybean cell cultures

Roncel Gil, Mercedes; Yruela Guerrero, Inmaculada; Kirilovsky, D.; Guerrero, Fernando; Alfonso Lozano, Miguel; Picorel Castaño, Rafael; Ortega Rodríguez, Jose María
2007-06-01

Digital.CSIC (Spain)

59

Cell type-specific role of the retinoblastoma/E2F pathway during arabidopsis leaf development

Desvoyes, Bénédicte; Ramírez-Parra, Elena; Xie, Qi; Chua, Nam-Hai; Gutiérrez Armenta, Crisanto
2005-12-16

Digital.CSIC (Spain)

60

Biochemical basis of SOS-induced mutagenesis in Escherichia coli: Reconstitution of in vitro lesion bypass dependent on the UmuD′2C mutagenic complex and RecA protein

Tang, Mengjia; Bruck, Irina; Eritja Casadellà, Ramón; Turner, Jennifer; Frank, Ekaterina G.; Woodgate, Roger; O’Donnell, Mike; Goodman, Myron F.
1998-08-18

Digital.CSIC (Spain)

61

Bacillus subtilis SbcC protein plays an important role in DNA inter-strand cross-link repair

Mascarenhas, Judita; Sánchez, Humberto; Tadesse, Serkalem; Kidane, Dawit; Krisnamurthy, Mahalakshmi; Alonso, Juan Carlos; Graumann, Peter L.
2006-06-16

Digital.CSIC (Spain)

62

Analysis of DNA processing reactions in bacterial conjugation by using suicide oligonucleotides

González Pérez, Blanca; Lucas, María; Cooke, Leonie A.; Vyle, Joseph S.; Cruz, Fernando de la; Moncalián, Gabriel
2007-07-26

Digital.CSIC (Spain)

63

All in one: Leishmania major STT3 proteins substitute for the whole oligosaccharyltransferase complex in Saccharomyces cerevisiae

Nasab, Farnoush P.; Schulz, Benjamin L.; Gamarro, Francisco; Parodi, Armando J.; Aebi, Markus
2008-07-02

Digital.CSIC (Spain)

64

A single nucleotide substitution in the internal ribosome entry site of foot-and-mouth disease virus leads to enhanced cap-independent translation in vivo

Martínez-Salas, Encarnación; Sáiz, Juan Carlos; Dávila, Mercedes; Belsham, Graham J.; Domingo, Esteban
1993-01-01

Digital.CSIC (Spain)

65

A maize embryo-specific gene encodes a proline-rich and hydrophobic protein

José Estanyol, Matilde; Ruiz Ávila, Luis; Puigdomènech, Pere
1992-04-01

Digital.CSIC (Spain)