Use of human MAR elements to improve retroviral vector production.

Retroviral vectors have many favorable properties for gene therapies, but their use remains limited by safety concerns and/or by relatively lower titers for some of the safer self-inactivating (SIN) derivatives. In this study, we evaluated whether increased production of SIN retroviral vectors can be achieved from the use of matrix attachment region (MAR) epigenetic regulators. Two MAR elements of human origin were found to increase and to stabilize the expression of the green fluorescent protein transgene in stably transfected HEK-293 packaging cells. Introduction of one of these MAR elements in retroviral vector-producing plasmids yielded higher expression of the viral vector RNA. Consistently, viral titers obtained from transient transfection of MAR-containing plasmids were increased up to sixfold as compared with the parental construct, when evaluated in different packaging cell systems and transfection conditions. Thus, use of MAR elements opens new perspectives for the efficient generation of gene therapy vectors.

Quick Reads, Mar 6, 2008

IDPH Quick Reads is an electronic newsletter produced by the Director’s Office at the Iowa Department of Public Health. IDPH Quick Reads are published every three to four weeks.

Quick Reads, Mar 27, 2008

IDPH Quick Reads is an electronic newsletter produced by the Director’s Office at the Iowa Department of Public Health. IDPH Quick Reads are published every three to four weeks.

Gênese e classificação de solos numa topossequência no ambiente de mar de morros do médio Vale do Paraíba do Sul, RJ

Solos tropicais são geralmente considerados altamente intemperizados, o que é atribuído às condições climáticas de altas temperaturas e precipitação pluvial. Entretanto, no ambiente de Mar de Morros, a intensidade dos processos pedogenéticos pode ser alterada pela remoção de material, em consequência do relevo movimentado, rejuvenescendo as superfícies. Este trabalho teve como objetivos caracterizar e classificar solos, formados a partir de muscovita-biotita gnaisse, em uma topossequência em Pinheiral (RJ). Os perfis localizam-se nos seguintes pontos da topossequência: (P1) topo de elevação, (P2) terço superior, (P3) terço médio, (P4) terço inferior e (P5) em área plana de várzea. Os perfis foram descritos, caracterizados e classificados segundo o Sistema Brasileiro de Classificação de Solos (SiBCS). As características edáficas que se destacaram foram: relação silte/argila; valor V %; valor T; ki; mineralogia da fração argila; e formas de Fe pedogênicas de alta cristalinidade (Fed). Ao longo da topossequência encontrou-se Cambissolo Háplico Tb distrófico típico no topo e no terço médio da topossequência. No terço superior foi identificado um Argissolo Vermelho-Amarelo distrófico típico e, no terço inferior, um Argissolo Amarelo eutrófico típico. Já na área plana de várzea foi observado um Gleissolo Háplico Tb distrófico típico. O relevo e o material de origem gnáissico estratificado foram os principais fatores que alteram a pedogênese.

Artificial neural networks applied for soil class prediction in mountainous landscape of the Serra do Mar¹

Soil information is needed for managing the agricultural environment. The aim of this study was to apply artificial neural networks (ANNs) for the prediction of soil classes using orbital remote sensing products, terrain attributes derived from a digital elevation model and local geology information as data sources. This approach to digital soil mapping was evaluated in an area with a high degree of lithologic diversity in the Serra do Mar. The neural network simulator used in this study was JavaNNS and the backpropagation learning algorithm. For soil class prediction, different combinations of the selected discriminant variables were tested: elevation, declivity, aspect, curvature, curvature plan, curvature profile, topographic index, solar radiation, LS topographic factor, local geology information, and clay mineral indices, iron oxides and the normalized difference vegetation index (NDVI) derived from an image of a Landsat-7 Enhanced Thematic Mapper Plus (ETM+) sensor. With the tested sets, best results were obtained when all discriminant variables were associated with geological information (overall accuracy 93.2 - 95.6 %, Kappa index 0.924 - 0.951, for set 13). Excluding the variable profile curvature (set 12), overall accuracy ranged from 93.9 to 95.4 % and the Kappa index from 0.932 to 0.948. The maps based on the neural network classifier were consistent and similar to conventional soil maps drawn for the study area, although with more spatial details. The results show the potential of ANNs for soil class prediction in mountainous areas with lithological diversity.

Identification of a potent MAR element from the mouse genome and assessment of its activity in stable and transient transfections.

Matrix attachment regions are DNA sequences found throughout eukaryotic genomes that are believed to define boundaries interfacing heterochromatin and euchromatin domains, thereby acting as epigenetic regulators. When included in expression vectors, MARs can improve and sustain transgene expression, and a search for more potent novel elements is therefore actively pursued to further improve recombinant protein production. Here we describe the isolation of new MARs from the mouse genome using a modified in silico analysis. One of these MARs was found to be a powerful activator of transgene expression in stable transfections. Interestingly, this MAR also increased GFP and/or immunoglobulin expression from some but not all expression vectors in transient transfections. This effect was attributed to the presence or absence of elements on the vector backbone, providing an explanation for earlier discrepancies as to the ability of this class of elements to affect transgene expression under such conditions.

Jornades d'Història de la Medicina a la Garrotxa : Olot, 28 i 29 de març de 1987

Amb aquest número, la revista "Gimbernat" deixa de centrar-se en els Congressos d'Història de la Medicina Catalana i s'obre a altres esdeveniments, també més locals, en aquest cas, les primeres Jornades d'Història de la Medicina a la Garrotxa. En aquest volum trobem el resum de les diferents ponències i comunicacions.

Jornades d'Història de la Medicina a la Garrotxa : Olot, 28 i 29 de març de 1987

Amb aquest número, la revista "Gimbernat" deixa de centrar-se en els Congressos d'Història de la Medicina Catalana i s'obre a altres esdeveniments, també més locals, en aquest cas, les primeres Jornades d'Història de la Medicina a la Garrotxa. En aquest volum trobem el resum de les diferents ponències i comunicacions.

Congrés Internacional: "De la dictadura a la democràcia : les dones en l'Europa mediterrània, central i de l'est"

El mes de setembre de 1993, el departament d'Història Contemporània de la Universitat de Barcelona i l'european Network for Women's Studies (ENWS) del Consell d'Europa van organitzar el congrés internacional "De la dictadura a la democràcia: les dones en l'Europa mediterrània central i de l'est". Lóbjectiu del congrés va ser desenvolupar una reflexió entorn de la trajectòria de les dones en les crisis dels antics règims dictatorials i en la transició democràtica.

A.A.V.V.: Montbarbat (1978-1986), Lloret de Mar, 1996

Debe reconocerse que en estos años próximos al fin del milenio la publicación de estudios sobre el mundo ibérico goza de excelente salud, cuando menos en volumen. Artículos, ponencias y comunicaciones amenazan con abrumar al lector más impenitente. Por ello resulta aleccionador acudir al meritorio trabajo de Fernando Quesada: "La cultura ibérica: una aproximación bibliográfica (1992-1993)", RE/b, 1, 1994, 335-377, que reúne la producción en revistas y series no excesivamente locales -imposibles de controlar, por otro lado-, y comprobar un balance de unos doscientos títulos anuales. Ahora bien, si consideramos el número de monografías, nos situaremos en un plano selectivo, que rondará la docena al año. Diversos factores -y entre ellos la desidia de diferentes niveles administrativos y académicos- parecen confabularse para que no se disponga de un conjunto de memorias impresas proporcional al volumen de excavaciones realizadas en las dos últimas décadas.

Quesada Sanz, Fernando y Zamora Merchán, Mar (eds.), El caballo en la antigua Iberia (estudios sobre los équidos en la Edad del Hierro), Bibliotheca Archaeologica Hispana, 19, Madrid, 2003, 253 pp.

La colaboración editorial entre la Real Academia de la Historia y la Universidad Autónoma de Madrid ha hecho posible el libro que nos ocupa, inscrito en la espléndida serie de temas peninsulares BAH. colección que alcanza ya los 19 títulos en sus primeros cuatro años de existencia. El caballo en la antigua Iberia aborda un tema necesitado de una revisión en nuestro actual panorama historiográfico; tal objetivo se cumple mediante una serie de capítulos independientes, fruto del trabajo de diversos estudiosos y especialistas que, desde metodologías y ciencias muy diferentes entre sí, tienen en común un mismo objeto de estudio.