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Search Results: 1 - 10 of 144179 matches for " B. Cisterna "
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Muscleblind-like1 undergoes ectopic relocation in the nuclei of skeletal muscles in myotonic dystrophy and sarcopenia
M. Malatesta,M. Giagnacovo,M. Costanzo,B. Cisterna
European Journal of Histochemistry , 2013, DOI: 10.4081/ejh.2013.e15
Abstract: Muscleblind-like 1 (MBNL1) is an alternative splicing factor involved in postnatal development of skeletal muscles and heart in humans and mice, and its deregulation is known to be pivotal in the onset and development of myotonic dystrophy (DM). In fact, in DM patients this protein is ectopically sequestered into intranuclear foci, thus compromising the regulation of the alternative splicing of several genes. However, despite the numerous biochemical and molecular studies, scarce attention has been paid to the intranuclear location of MBNL1 outside the foci, although previous data demonstrated that in DM patients various splicing and cleavage factors undergo an abnormal intranuclear distribution suggestive of impaired RNA processing. Interestingly, these nuclear alterations strongly remind those observed in sarcopenia i.e., the loss of muscle mass and function which physiologically occurs during ageing. On this basis, in the present investigation the ultrastructural localization of MBNL1 was analyzed in the myonuclei of skeletal muscles from healthy and DM patients as well as from adult and old (sarcopenic) mice, in the attempt to elucidate possible changes in its distribution and amount. Our data demonstrate that in both dystrophic and sarcopenic muscles MBNL1 undergoes intranuclear relocation, accumulating in its usual functional sites but also ectopically moving to domains which are usually devoid of this protein in healthy adults. This accumulation/delocalization could contribute to hamper the functionality of the whole splicing machinery, leading to a lower nuclear metabolic activity and, consequently, to a less efficient protein synthesis. Moreover, the similar nuclear alterations found in DM and sarcopenia may account for the similar muscle tissue features (myofibre atrophy, fibre size variability and centrally located nuclei), and, in general, for the aging-reminiscent phenotype observed in DM patients.
Discrete foci containing RNAse A are found in nucleoli of HeLa cells after aging in culture
M. Costanzo,B. Cisterna,O. O. Zharskaya,O. V. Zatsepina
European Journal of Histochemistry , 2011, DOI: 10.4081/ejh.2011.e15
Abstract: We have studied by means of ultrastructural immunocytochemistry the localization of RNase A in nuclei of HeLa cells in control conditions and following cell ageing in culture. We have found that roundish, electron dense foci, which contain a significant amount of RNAse A, can be detected within nucleoli of aged cells. These bodies also contain RNA and lack ribosomal S3 proteins, and may represent either simple storage sites or areas where RNA degradation takes place.
Ultrastructural analysis of testes from mice fed on genetically modified soybean
L Vecchio,B Cisterna,M Malatesta,TE Martin
European Journal of Histochemistry , 2004, DOI: 10.4081/920
Abstract: We have considered the possible effects of a diet containing genetically modified (GM) soybean on mouse testis. This organ, in fact, is a well known bioindicator and it has already been utilized, for instance, to monitor pollution by heavy metals. In this preliminary study, we have focussed our attention on Sertoli cells, spermatogonia and spermatocytes by means of immunoelectron microscopy. Our results point out that the immunolabelling for Sm antigen, hnRNPs, SC35 and RNA Polymerase II is decreased in 2 and 5 month-old GM-fed mice, and is restored to normal at 8 months. In GM-fed mice of all ages considered, the number of perichromatin granules is higher and the nuclear pore density lower. Moreover, we found enlargements in the smooth endoplasmic reticulum in GM-fed mice Sertoli cells. A possible role played by traces of the herbicide to which the soybean is resistant is discussed.
Can a genetically-modified organism-containing diet influence embryo development? A preliminary study on pre-implantation mouse embryos
B Cisterna,F Flach,L Vecchio,SML Barabino
European Journal of Histochemistry , 2008, DOI: 10.4081/1226
Abstract: In eukaryotic cells, pre-mRNAs undergo several transformation steps to generate mature mRNAs. Recent studies have demonstrated that a diet containing a genetically modified (GM) soybean can induce modifications of nuclear constituents involved in RNA processing in some tissues of young, adult and old mice. On this basis, we have investigated the ultrastructural and immunocytochemical features of pre-implantation embryos from mice fed either GM or non- GM soybean in order to verify whether the parental diet can affect the morpho-functional development of the embryonic ribonucleoprotein structural constituents involved in premRNA pathways. Morphological observations revealed that the general aspect of embryo nuclear components is similar in the two experimental groups. However, immunocytochemical and in situ hybridization results suggest a temporary decrease of pre-mRNA transcription and splicing in 2-cell embryos and a resumption in 4-8-cell embryos from mice fed GM soybean; moreover, pre-mRNA maturation seems to be less efficient in both 2-cell and 4-8-cell embryos from GM-fed mice than in controls. Although our results are still preliminary and limited to the pre-implantation phases, the results of this study encourage deepening on the effects of food components and/or contaminants on embryo development.
Faja Intrusiva La Majada, sierra de Ancasti, Catamarca: Caracterización petrológica-estructural La Majada magmatic belt, Sierra de Ancasti, Catamarca: Petrological and structural characterization
C.E. Cisterna
Revista de la Asociación Geológica Argentina , 2003,
Abstract: La Faja Intrusiva La Majada se extiende con rumbo NNO-SSE a lo largo de 40 km aproximadamente, en el sector centro - sur de la sierra de Ancasti, SE de la provincia de Catamarca. Está constituida por un basamento metamórfico compuesto por esquistos y gneises bandeados cuyas paragénesis minerales corresponden a un metamorfismo de mediano a alto grado. Están deformados según dos episodios D1 y D2. En este tramo de la sierra, donde la deformación D2 es más intensa, se produce un importante magmatismo, representado por la intrusión de una secuencia ígnea sintectónica cuya composición varía de gabros y dioritas, tonalitas, granodioritas y monzogranitos. Su emplazamiento se produjo en el pico del metamorfismo M2, junto con el desarrollo de procesos de fusión del cual resultaron distintos tipos de migmatitas. También se reconoce la intrusión de granitos, leucogranitos y pegmatitas, que se emplazan en una etapa sin a tardío tectónica. El estrecho vínculo entre mayor deformación y metamorfismo, con desarrollo de migmatitas y mayores volúmenes de emplazamientos de plutonitas sugiere que el magmatismo, metamorfismo y deformación estarían estrechamente vinculados temporalmente y ligados a una zona de cizalla profunda de edad paleozoica inferior. La Majada area occur within a NNW-SSE trending along 40 kilometers in the SE Catamarca province. Is formed by schists and gneisses where the first schistosity (D1) is tightly folded and transposed by a second deformation (D2), which is coeval with the peak metamorphism (M2) and magmatism. Synkinematic granitoids emplacements are two different suites of igneous rocks : a) a magmatic sequence, consisting of small gabbro - diorite bodies and tonalite, granodiorite and monzogranite plutons; and b) granites, leucogranites and pegmatites. The relations between folds and crenulation cleavage in the metamorphic rocks and deformational fabrics in the granitoids and migmatites provide good evidence for the penecontemporaneity of deformational processes, magmatism and migmatization.
Granitoides paleozoicos de la Sierra de Narváez, Sistema de Famatina, Argentina: Hibridización de magmas en un margen continental activo
Cisterna, C. E.
Estudios Geologicos , 1992, DOI: 10.3989/egeol.92485-6389
Abstract: The granitoids from the Sierra de Narváez were investigated for their geochemical and petrographical characteristics. They are composed of calc-alkaline granites, granodiorites and tonalites, similar to the other paleozoic granitoids of the Famatina System. These rocks are intrusive in the Las Planchadas (volcanic rocks) and Suri (sedimentary rocks) Formations, which are probably cogenetic with the granitoids within the same magmatic cycle. The study of the granitoids reveals the close relationship between their composition and the abundance of the enclosed magmatic inclusions. The latter represent rocks and granodioritic tonalitic and diorite composition, and have a great number of mineralogical characteristic that suggest the presence of two magmas, mafic and felsic for the origin of such enclaves. The close chemical relationship existing between the inclusions and their host rocks shows that the mafic and felsic components are compositionally modified and that the granitoids are more or less hybridized. Trace elements discrimination diagrams have been used as a tools for fingerprinting the tectonic setting of the Sierra de Narváez granitoids. The geochemistry as well as the geologic relations of the granitoids with the roughly coeval ordovician vulcanism indicate a volcanic arc environment. Las rocas que afloran en el extremo septentrional de la Sierra de Narváez están representadas por una asociación de monzogranitos, granodioritas y tonalitas que definen una serie calcoalcalina, de características similares a las de otros intrusivos del Paleozoico del Sistema de Famatina. Estos granitoides se hallan intruyendo las Formaciones Las Planchadas y Suri, representadas por vulcanitas y metasedimentitas, respectivamente, y corresponderían a un mismo evento magmático del Paleozoico Inferior. Los granitoides estudiados presentan abundantes inclusiones ígneas de composición granodiorítica o tonalítica y diorítica. La estrecha relación que existe en el quimismo de estas rocas, junto a las evidencias petrográficas y geológicas, nos hace pensar que la presencia de estos enclaves se debería a un proceso de interacción de magmas, félsico y máfico, los que habrían sufrido considerables modificaciones composicionales con la hibridación de los granitoides. La utilización de los elementos trazas en diagramas discriminatorios, juntamente con las relaciones geológicas establecidas y las características petrográficas y químicas, nos permite inferir que los granitoides de la Sierra de Narváez corresponderían a un ambiente tectónico de arco volcánico, íntimamente relaciona
Asymptotically (anti) de Sitter Black Holes and Wormholes with a Self Interacting Scalar Field in Four Dimensions
Andres Anabalon,Adolfo Cisterna
Physics , 2012, DOI: 10.1103/PhysRevD.85.084035
Abstract: The aim of this paper is to report on the existence of a wide variety of exact solutions, ranging from black holes to wormholes, when a conformally coupled scalar field with a self interacting potential containing a linear, a cubic and a quartic self interaction is taken as a source of the energy-momentum tensor, in the Einstein theory with a cosmological constant. Among all the solutions there are two particularly interesting. On the one hand, the spherically symmetric black holes when the cosmological constant is positive; they are shown to be everywhere regular, namely there is no singularity neither inside nor outside the event horizon. On the other hand, there are spherically symmetric and topological wormholes that connect two asymptotically (anti) de Sitter regions with a different value for the cosmological constant. The regular black holes and the wormholes are supported by everywhere regular scalar field configurations.
Efusiones básicas subácueas de edad arenigiana en el norte del Sistema de Famatina, noroeste de Argentina
Cisterna,Clara E; Coira,Beatriz; Koukharsky,Magdalena;
Serie correlaci?3n geol?3gica , 2012,
Abstract: this paper focuses on the analysis of the ordovician successions that outcrop along the sierra de las planchadas - narvaez, northern famatina system. they are the earliest records of the arenig of the region, as evidenced by the fossiliferous content and the overlying deposits of dacitic lavas, volcaniclastic resedimented syn-eruptive facies and volcanogenic facies, which complete the column. the analyzed sections from north to south are: - quebrada larga - punta colorada section, mainly composed of lavic facies and related autobreccias and hyaloclastites facies. - quebrada larga - punta pétrea section, that display several lavic facies (basalts, andesites and dacites) in associating with hyaloclastic and pillow breccias. to the upper portions of the profile are syn- eruptive resedimented volcaniclastic facies (breccias and psamites) and volcanogenic members, mainly represented by psamitic and pelitic rocks with fossils. - vuelta de las tolas section, where the basic lavas and related autobreccias underlying the volcanogenic deposits. the comparative analysis of the chemical basic lavas characteristics indicates that they are of the same nature and show tholeiitic affinities. this study indicates that the arenigian volcanic events were began as effusions related to a volcanic island arc, with submarine basalts and during their emplacement were produced in situ fragmentation processes, generating great volumes of autobreccias and hyaloclastites deposits.
Sucesiones volcánico-sedimentarias tremadocianas y arenigianas en la sierra de las Planchadas-Narváez: registros evolutivos del arco magmático Famatiano Tremadoc and Arenig volcano-sedimentary successions in the Sierra de Las Planchadas, Narváez: Evolutive records of the Famatinian magmatic arc
Clara Eugenia Cisterna,Beatriz Coira,Magdalena Koukharsky
Revista de la Asociación Geológica Argentina , 2010,
Abstract: Se analizan secciones volcano-sedimentarias ordovícicas del norte del Sistema de Famatina, aportando nuevos datos petrológicos para la comprensión de la naturaleza de sus magmas y de los procesos volcanológicos asociados con la evolución del arco magmático en la región. Información paleontológica previa, apoyada por estudios estructurales y por las relaciones de intrusividad con una granodiorita de 485 ± 7 Ma, asignaron edades del Tremadociano temprano a las sedimentitas de Las Angosturas y del Arenigiano temprano - medio a las de las secciones Vuelta de la Tolas - Chaschuil y quebrada Larga - Punta Pétrea. Los litotipos que integran la sucesión tremadociana son lavas basálticas, andesíticas, dacíticas y riodacíticas, interestratificadas con limolitas y psamitas finas, polideformadas y con importante alteración hidrotermal, habiéndose reconocido paragénesis de metamorfismo de bajo grado y de contacto. Los depósitos arenigianos, afectados por plegamiento y desarrollo de clivaje localmente, consisten en lavas basálticas, andesíticas, dacíticas y riolíticas, facies hialoclásticas, depósitos resedimentados sin-eruptivos y volcanogénicos. Si bien ambas asociaciones son subalcalinas y peraluminosas, se concluye, para los representantes tremadocianos, que sus características son consistentes con un ambiente donde fueron producidos fundidos de un manto empobrecido (MORB) y enriquecidos durante eventos de subducción, asociados con la evolución de una cuenca marginal. Las volcanitas arenigianas muestran filiación geoquímica de arco magmático continental. Ambas asociaciones exhiben características similares a las observadas en la Puna occidental, lo que plantearía la posible continuación en la Puna del arco magmático ordovícico reconocido en el Sistema de Famatina. Volcano-sedimentary Ordovician sections from the north of the Sistema de Famatina are analyzed, contributing with new petrological data to the understanding of the nature of magmas and associated volcanic processes related to the evolution of the magmatic arc in the region. Previous paleontological information, supported by structural studies and contact relationships with a granodiorite dated in 485 ± 7 Ma, assigned to these sedimentary rocks of Las Angosturas an early Tremadoc age, as well as an early to middle Arenig age to those of the Vuelta de Las Tolas - Chaschuil and Quebrada Larga - Punta Pétrea sections. The lithotypes that integrate the Tremadoc successions are basaltic, andesitic, dacitic and rhyodacitic lavas, interfingered with massive and laminated siltstones and fine psammites, with super
Estructura interna de la franja migmatítica del núcleo cristalino de las sierras Pampeanas septentrionales del Noroeste Argentino Internal structure of the migmatitic belt in the crystalline core of the northern Sierras Pampenas Northwestern Argentina
Clara Eugenia Cisterna,Ricardo Mon,Rodolfo Mena
Revista de la Asociación Geológica Argentina , 2010,
Abstract: El Complejo Las Ca as en la sierra de Aconquija (Sierras Pampeanas Septentrionales, NO de Argentina) está integrado por rocas del basamento cristalino, representadas por migmatitas y en menor proporción por esquistos, que se hallan como resisters en ellas. Las migmatitas varían desde metatexitas a diatexitas y muestran una foliación migmatítica, acompa ada de pliegues intrafoliales formados bajo condiciones de elevado metamorfismo, con fusión parcial y anatexis. Un plegamiento posterior, en condiciones de elevada ductilidad, genera figuras de interferencia. Finalmente, se reconoce un episodio de deformación por cizallamiento dúctil - frágil que afecta parcialmente a las migmatitas, con sectores donde sus manifestaciones están más intensamente desarrolladas que en otros. Las observaciones de campo, estructurales y petrográficas permiten definir para estas rocas episodios de deformación pre, sin y post migmatíticos e interpretar que la evolución de este tramo del basamento cristalino del noroeste de Argentina se habría desarrollado en un cinturón móvil que integró el borde occidental del Gondwana, donde los episodios deformacionales reconocidos tienen correspondencia con el ciclo pampeano (550 - 500 Ma) y la sobreimposición del ciclo famatiniano (500 - 440 Ma). The Las Ca as Complex located in Aconquija Range (Sierras Pampeanas Septentrionales) is formed by rocks of the crystalline basement, mainly migmatites and, in smaller proportion, schists which are as resisters included in the migmatites. The migmatites range from metatexites to diatexites. They show a migmatitic foliation accompanied by intrafoliated folds generated under high metamorphic conditions, with partial melt and anatexis. A later superposed folding episode under high ductile conditions generated interference patterns. Finally a brittle-ductile shear episode involving the migmatites is recognized. It affects some portions more intensively than others; its distribution is not uniform. The structural and petrographic observations in the field and in microscope allow the recognition of pre, syn and post migmatization deformation episodes. This tectonic evolution occurred along a significant stretch of the crystalline basement of NW Argentina in a mobile belt along the west border of supercontinent Gondwana, where the recognized deformation episodes correspond to the Pampean Orogeny (550 - 500 Ma) and to the superposed Famatinian Orogeny (500 - 440 Ma).
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