997 resultados para Allen, William, 1770-1843.


Relevância:

100.00% 100.00%

Publicador:

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Hypoxia results in adaptive changes in the transcription of a range of genes including erythropoietin. An important mediator is hypoxia-inducible factor-1 (HIF-1), a DNA binding complex shown to contain at least two basic helix-loop-helix PAS-domain (bHLH-PAS) proteins, HIF-1 alpha and aryl hydrocarbon nuclear receptor translocator (ARNT), In response to hypoxia, HIF-1 alpha is activated and accumulates rapidly in the cell. Endothelial PAS domain protein 1 (EPAS-1) is a recently identified bHLH-PAS protein with 48% identity to HIF-1 alpha, raising the question of its role in responses to hypoxia. We developed specific antibodies and studied expression and regulation of EPAS-1 mRNA and protein across a range of human cell lines. EPAS-1 was widely expressed, and strongly induced by hypoxia at the level of protein but not mRNA. Comparison of the effect of a range of activating and inhibitory stimuli showed striking similarities in the EPAS-1 and HIF-1 alpha responses. Although major differences were observed in the abundance of EPAS-1 and HIF-1 alpha in different cell types, differences in the inducible response were subtle with EPAS-1 protein being slightly more evident in normoxic and mildly hypoxic cells. Functional studies in a mutant cell line (Ka13) expressing neither HIF-1 alpha nor EPAS-1 confirmed that both proteins interact with hypoxically responsive targets, but suggest target specificity with greater EPAS-1 transactivation (relative to HIF-1 alpha transactivation) of the VEGF promoter than the LDH-A promoter. (C) 1998 by The American Society of Hematology.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Objectives: Unlike adult dermal wounds, the oral mucosa demonstrates preferential healing characterized by rapid remodeling and re-epithelialisation, with minimal scar formation. Secretory leukocyte protease inhibitor (SLPI) is an epithelial-derived factor with potential for promoting scarless repair. The aims of this study were to: (i) investigate the directed migratory (chemotaxis) response of oral and skin fibroblasts to various concentrations of SLPI; and (ii) compare migratory speed of the two cell types. Methods: Paired oral and skin fibroblasts were seeded at 2x104 cells in six well plates containing glass coverslips, and cultured in DMEM supplemented with 10% FCS for 48hours. Following a period of serum starvation (18hours in DMEM plus 0.5% BSA), coverslips were incorporated within a Dunn chemotaxis chamber containing DMEM with 0.5% BSA +/- SLPI gradients at 0.5, 1 or 2µM concentrations. Using microscopy, the migratory behaviour of cells was digitally captured every 10mins for 18hours, traced with JCell tracking software and resulting co-ordinates statistically analysed using Mathmatica software. Results: At all concentrations SLPI was a significant chemoattractant (p<0.01) for both cell types. However, skin fibroblasts migrated significantly faster than oral cells at each SLPI concentration, with greatest effect observed at the highest dose (skin: 32.0±0.47µm/hr, oral: 13.6±0.23µm/hr). Conclusion: SLPI is a chemoattractant for both oral and skin fibroblasts, and may play an important role in fibroblast recruitment during wound healing. This work was funded by the R&D Office, N.Ireland.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Tese de doutoramento, Filosofia (Filosofia em Portugal), Universidade de Lisboa, Faculdade de Letras, 2014

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Este recurso cubre juegos al aire libre, de aventura y actividades de atletismo y proporciona directrices para la enseñanza de sus habilidades básicas y las prácticas para desarrollarlas. Es una guía para la enseñanza de educación física, no de instrucción y por lo tanto permite soluciones flexibles y adaptables a las necesidades del grupo. Ofrece ciento veinte actividades organizadas por deporte y grupo de edad que se pueden utilizar para comenzar las lecciones, o como base para una lección completa.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Why some organisms become invasive when introduced into novel regions while others fail to even establish is a fundamental question in ecology. Barriers to success are expected to filter species at each stage along the invasion pathway. No study to date, however, has investigated how species traits associate with success from introduction to spread at a large spatial scale in any group. Using the largest data set of mammalian introductions at the global scale and recently developed phylogenetic comparative methods, we show that human-mediated introductions considerably bias which species have the opportunity to become invasive, as highly productive mammals with longer reproductive lifespans are far more likely to be introduced. Subsequently, greater reproductive output and higher introduction effort are associated with success at both the establishment and spread stages. High productivity thus supports population growth and invasion success, with barriers at each invasion stage filtering species with progressively greater fecundity.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

One-page sheet with handwritten essay titled, "Know then thyself, presume not God to scan, The proper study of mankind is man," composed by graduate Ward Cotton for the July 17, 1793 Harvard University Commencement. The essay begins with the quote "'Man is a being composed of an organized body, and a rational soul.'"

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Mode of access: Internet.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Mode of access: Internet.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

"The text of this volume is based upon that of Halm's fourth edition of Tacitus (Leipsic, 1882)"--Pref.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

"The text of this volume is based upon that of Halm's fourth edition of Tacitus (Leipsic, 1882)"--Pref.