Search results for "primer"
showing 10 items of 530 documents
The evolution of the heat-shock protein GroEL from Buchnera, the primary endosymbiont of aphids, is governed by positive selection
2002
The heat-shock protein GroEL is a double-ring-structured chaperonin that assists the folding of many newly synthesized proteins in Escherichia coli and the refolding in vitro, with the cochaperonin GroES, of conformationally damaged proteins. This protein is constitutively overexpressed in the primary symbiotic bacteria of many insects, constituting approximately 10% of the total protein in Buchnera, the primary endosymbiont of aphids. In the present study, we perform a maximum likelihood (ML) analysis to unveil the selective constraints in GroEL. In addition, we apply a new statistical approach to determine the patterns of evolution in this highly interesting protein. The main conclusion d…
Evidence for a novel cytoplasmic processing event in ribosome maturation in the sea urchin Paracentrotus lividus
2010
In this work, we demonstrate the existence of a cytoplasmic processing step, never before described, involving both the pre-ribosomal subunits in the sea urchin Paracentrotus lividus. Northern-blot hybridization, primer extension, S1 mapping experiments and in situ hybridizations allowed us to demonstrate that cytoplasmic processed particles are successively re-imported into the nucleus, where maturation of their RNAs is completed prior to being exported to the cytoplasm. Our findings lead to the proposal of a new model of ribosome maturation and shuttling. Moreover, preliminary data from our laboratory suggest that the maturation pathway we propose in P. lividus may not be unique to the se…
Hydrophilic primer has double the risk of bracket bond failure
2002
Question: In patients who need orthodontic bracketing is a hydrophilic primer or a conventional primer more effective for bonding? Objective To compare clinical failure rates of brackets bonded with a prototype hydrophilic primer and conventional primer. Design Randomised controlled trial (RCT) in a hospital setting. Intervention A split mouth design was used. Sides were randomly allocated to either hydrophilic (supplied by 3M Unitek (Monrovia, California, USA) or conventional primer (conventional TransbondTM 3M Unitek) adhesive), with the other side having alternative primer. Brackets were applied to 33 patients using a standard procedure. A total of 266 bonds were completed with each prim…
Cyclic adenosine monophosphate is a key component of regulatory T cell–mediated suppression
2007
Naturally occurring regulatory T cells (T reg cells) are a thymus-derived subset of T cells, which are crucial for the maintenance of peripheral tolerance by controlling potentially autoreactive T cells. However, the underlying molecular mechanisms of this strictly cell contact–dependent process are still elusive. Here we show that naturally occurring T reg cells harbor high levels of cyclic adenosine monophosphate (cAMP). This second messenger is known to be a potent inhibitor of proliferation and interleukin 2 synthesis in T cells. Upon coactivation with naturally occurring T reg cells the cAMP content of responder T cells is also strongly increased. Furthermore, we demonstrate that natur…
Psicothema
2018
Resumen tomado de la publicación WebLEC: una prueba para evaluar la competencia lectora en Internet de los adolescentes. Antecedentes: leer en Internet requiere habilidades específicas (e.g., navegación) aparte de habilidades de comprensión. No existe en español un test para evaluar estas habilidades en población adolescente. El propósito de este trabajo es cubrir esta laguna con el test WebLEC, desarrollado a partir del marco de PISA. Método: WebLEC fue validado con estudiantes de Educación Secundaria Obligatoria (ESO) (n = 941). Incluye 28 ítems o tareas de tres tipos (acceso y recuperación, integrar e interpretar, y reflexionar y evaluar) aplicadas a 4 escenarios de lectura (portal web, …
A method for rapid generation of competitive standard molecules for RT-PCR avoiding the problem of competitor/probe cross-reactions.
1995
The analysis of gene expression is a widespread issue in a growing number of fields such as molecular genetics, immunology, and medical diagnostics. The ideal method for mRNA detection should be fast, inexpensive, sensitive, and reliable. Well-elaborated standard methods such as Northern hybridization, Sl-mapping, and RNAse protection are useful and recommended, but only reverse transcription PCR (RT-PCR) gives the highest possible sensitivity required. For many issues it is necessary not only to detect a distinct mRNA but to compare changes in mRNA levels. The use of RT-PCR for such semiquantitative and quantitative approaches resolves problems attributable to the intrinsic property of PCR…
Maturation of epidermal Langerhans cells: increased expression of beta- and gamma-actin isoforms as a basis of specialized cell functions.
1999
Epidermal Langerhans cells (LC) represent immature dendritic cells. During in vitro culture in the presence of keratinocytes they mature into potent immunostimulatory cells for naive T cells. This process is thought to simulate in vivo maturation of LC following activation by antigen contact. Maturation of LC is accompanied by morphological alterations. Applying a differential screening procedure we isolated differentially expressed cDNAs involved in the maturation events including cDNAs of the cytoskeletal actin isoforms beta- and gamma-actin. Stronger signals with hybridization probes derived from cultured LC compared with probes derived from freshly isolated LC indicate upregulation of a…
On the roles of Notch, Delta, kuzbanian, and inscuteable during the development of Drosophila embryonic neuroblast lineages
2009
AbstractThe generation of cellular diversity in the nervous system involves the mechanism of asymmetric cell division. Besides an array of molecules, including the Par protein cassette, a heterotrimeric G protein signalling complex, Inscuteable plays a major role in controlling asymmetric cell division, which ultimately leads to differential activation of the Notch signalling pathway and correct specification of the two daughter cells. In this context, Notch is required to be active in one sibling and inactive in the other. Here, we investigated the requirement of genes previously known to play key roles in sibling cell fate specification such as members of the Notch signalling pathway, e.g…
The prologue and the fi rst stasimon of Oedipus at Colonus: a comparative study
2017
En este trabajo proponemos un análisis del estásimo primero de la tragedia Edipo en Colono de Sófocles a partir de los versos 16 a 18 del prólogo de la misma obra. La comparación entre ambos pasajes puede ser importante en la medida en que el ἄλσος descrito en el prólogo es presentado como un espacio, dramáticamente importante, que se desarrolla poéticamente en el primer estásimo. Ambas descripciones presentan puntos en común que no sólo pueden ayudarnos a entender mejor la naturaleza de este bosque sagrado, sino también evidencian la programación dramática de los susodichos versos prologales. In this paper we analyze the fi rst stasimon of the tragedy Oedipus at Colonus of Sophocles based …
Interethnic studies of TNF polymorphisms confirm the likely presence of a second MHC susceptibility locus in ankylosing spondylitis
2000
The objective of this study was to investigate TNF promoter region polymorphisms for association with susceptibility to ankylosing spondylitis (AS). The TNF -238 and -308 polymorphisms were genotyped in 306 English AS cases and 204 ethnically matched healthy B27-positive controls, and 96 southern German AS cases, 58 B27-positive and 251 B27-negative ethnically matched controls. Additionally, the TNF -376 polymorphism was genotyped in the southern German cases and controls. In the southern German AS patients a significant reduction in TNF -308.2 alleles was seen, compared with B27 positive controls (odds ratio 0.4, P = 0.03, 95% confidence interval 0.2-0.9), but no difference in allele frequ…