Differential roles of integrins alpha(2)beta(1), and alpha(IIb)beta(3) in collagen and CRP-induced platelet activation

Collagen and collagen-related peptide (CRP) activate platelets by interacting with glycoprotein (GP)VI. In addition, collagen binds to integrin alpha(2)beta(1) and possibly to other receptors. In this study, we have compared the role of integrins alpha(2)beta(1) and alpha(IIb)beta(3) in platelet activation induced by collagen and CRP. Inhibitors of ADP and thromboxane A(2) (TxA(2)) substantially attenuated collagen-induced platelet aggregation and dense granule release, whereas CRP-induced responses were only partially inhibited. Under these conditions, a proportion of platelets adhered to the collagen fibres resulting in dense granule release and alpha(IIb)beta(3) activation. This adhesion was substantially mediated by alpha(2)beta(1). The alpha(IIb)beta(3) antagonist lotrafiban potentiated CRP-induced dense granule release, suggesting that alpha(IIb)beta(3) outside-in signalling may attenuate GPVI signals. By contrast, lotrafiban inhibited collagen-induced dense granule release. These results emphasise the differential roles of alpha(2)beta(1) and alpha(IIb)beta(3) in platelet activation induced by collagen and CRP. Further, they show that although ADP and TxA(2) greatly facilitate collagen-induced platelet activation, collagen can induce full activation of those platelets to which it binds in the absence of these mediators, via a mechanism that is dependent on adhesion to alpha(2)beta(1).

SPACE SHUTTLE

6 projects of creativity and social interaction running in locations of low levels of cultural activity throughout Belfast, Funded through ACNI and Big Lottery

Expression of Staphylococcus aureus clumping factor A in Lactococcus lactis subsp. cremoris using a new shuttle vector.

Staphylococcus aureus harbors redundant adhesins mediating tissue colonization and infection. To evaluate their intrinsic role outside of the staphylococcal background, a system was designed to express them in Lactococcus lactis subsp. cremoris 1363. This bacterium is devoid of virulence factors and has a known genetic background. A new Escherichia coli-L. lactis shuttle and expression vector was constructed for this purpose. First, the high-copy-number lactococcal plasmid pIL253 was equipped with the oriColE1 origin, generating pOri253 that could replicate in E. coli. Second, the lactococcal promoters P23 or P59 were inserted at one end of the pOri253 multicloning site. Gene expression was assessed by a luciferase reporter system. The plasmid carrying P23 (named pOri23) expressed luciferase constitutively at a level 10,000 times greater than did the P59-containing plasmid. Transcription was absent in E. coli. The staphylococcal clumping factor A (clfA) gene was cloned into pOri23 and used as a model system. Lactococci carrying pOri23-clfA produced an unaltered and functional 130-kDa ClfA protein attached to their cell walls. This was indicated both by the presence of the protein in Western blots of solubilized cell walls and by the ability of ClfA-positive lactococci to clump in the presence of plasma. ClfA-positive lactococci had clumping titers (titer of 4,112) similar to those of S. aureus Newman in soluble fibrinogen and bound equally well to solid-phase fibrinogen. These experiments provide a new way to study individual staphylococcal pathogenic factors and might complement both classical knockout mutagenesis and modern in vivo expression technology and signature tag mutagenesis.

Evaluación del efecto de antibióticos quinolónicos de nueva generación e immunepotent CRP sobre el sistema inmune.

Tesis (Maestría en Ciencias con Especialidad en Inmunolobiología) UANL, 2011.

Efecto del immunepotent CRP en la respuesta clínica e inmunológica en pacientes con cáncer de mama.

Tesis (Maestría en Ciencias con Acentuación en Inmunobiología) UANL, 2010.

Estudio controlado, paralelo aleatorio y comparativo del efecto antiinflamatorio del ibuprofeno vs IMMUNEPOTENT CRP posterior a una cirugía de terceros molares inferiores en humanos.

Tesis (Maestría en Ciencias con Acentuación en Inmunolobiología) UANL, 2013.

Les biblioteques escolars, un nucli de treball dels CRP de Barcelona. 'Las bibliotecas escolares, un núcleo de trabajo de los CPR de Barcelona'.

Resumen en catalán de las autoras. El trabajo de las autoras se puede visitar en http://www.xtec.es/crp-santandreu/biblioteques.htm

Un nou àmbit de treball : el nucli de biblioteques dels CRP de Barcelona. 'Un nuevo ámbito de trabajo : el núcleo de bibliotecas de los CRP de Barcelona'.

Resumen tomado de la publicación en catalán. Este artículo forma parte del monográfico 'Documentar-se i llegir: experiencies escolars'

Revistes del CRP de Sabadell : un exemple de comunicació, colúlaboració i qualitat. 'Revistas del CRP de Sabadell : un ejemplo de comunicación, colaboración y calidad'.

Resumen de las autoras en catalán

Visquem la solidaritat : una experiència oberta : l'educació en valors des del CRP de Sant Andreu. 'Vivimos la solidaridad : una experiencia abierta : la educación en valores desde el CRP de Sant Andreu'.

Se hace mención del servicio que este Centro de Recursos Pedagógicos ofrece para proporcionar herramientas para trabajar los valores, desde el apoyo a la tarea docente, desenvolviendo actividades en el campo de la solidaridad. Se relatan diversas experiencias, destacando aspectos como la utilización de las nuevas tecnologías, el desarrollo de diversas actividades.

Year to year variation in the small scale distribution of shuttle mosses

A detailed spore investigation of spore release and dispersal from an isolated colony of Phascum cuspidatum Hedw. indicated that approximately 98% of the spores originally present remained within the colony. The spatial distribution of colonies of P.cuspidatum and Pottia truncata (Hedw.) Fürer. in relation to those of the previous year was investigated by mapping the occurrence of colonies in five permanent quadrats for each species during two successive years. Phascum cuspidatum reoccurred in three quadrats during the second year, and P. truncata in only one, in the latter case apparently due to invasion by other mosses, principally Barbula hornschuchiana Schultz. A substantial proportion of the second year colonies overlapped in position with the first year colonies, particularly in P.cuspidatum. The results are discussed in relation to data on spore dispersal and other aspects of the life-history of these annual or short-lived shuttle mosses.

Reproductive biology and population studies in two annual shuttle mosses

Observations on clumps of Phascum cuspidatum during the summer and autumn indicated that this species is at least a short-lived perennial, as young shoots develop from old, brown shoots persisting from the previous winter. No young shoots arising by vegetative propagation were recorded in Pottia truncata. Rhizoid tubers were observed in this species, but only in one of the many clumps examined. Spores of both species germinated freely in culture, but when spores were planted in the field young gametophytes developed inconsistently in P. truncata and never in P. cuspidatum. An investigation of spore deposition around an isolated clump of P. truncata suggested that 67% of the spores released were deposited within the clump, and 70% within 2m. Electrophoretic studies indicated limited genetic variation within two populations of each species, with no genotypes in common between the populations. No genetic variation was recorded between gametophytes within individual clumps of either species, nor between sporophytes and their maternal gametophytes, suggesting a high incidence of inbreeding in these monoecious mosses. (author abst.)