Purification and characterization of heparan sulfate from human primary osteoblasts

Heparan sulfate (HS) is a linear, highly variable, highly sulfated glycosaminoglycan sugar whose biological activity largely depends on internal sulfated domains that mediate specific binding to an extensive range of proteins. In this study we employed anion exchange chromatography, molecular sieving and enzymatic cleavage on HS fractions purified from three compartments of cultured osteoblasts-soluble conditioned media, cell surface, and extracellular matrix (ECM). We demonstrate that the composition of HS chains purified from the different compartments is structurally non-identical by a number of parameters, and that these differences have significant ramifications for their ligand-binding properties. The HS chains purified of conditioned medium had twice the binding affinity for FGF2 when compared with either cell surface or ECM HS. In contrast, similar binding of BMP2 to the three types of HS was observed. These results suggest that different biological compartments of cultured cells have structurally and functionally distinct HS species that help to modulate the flow of HS-dependent factors between the ECM and the cell surface.

What it means to become a public relations professional: student perceptions of professional identity through real-world learning

Public relations educators need new solutions to prepare students to become tomorrow's practitioner today. Managers and employers in the new creative workforce (McWilliam, 2008) expect graduates to be problem solvers, critical and creative thinkers, reflective, and self reliant (Barrie, 2008; David, 2004). Enabling students to develop these attributes requires a collaborative and creative approach to pedagogy (Jeffrey & Craft, 2001, 2004). A model for the next generation of public relations education was developed to integrate industry partnerships as a way to bridge pedagogy and professional practice. The model suggests (a) that industry partnerships be embedded in learning activities, (b) that assessment items be considered on a continuum and delivered incrementally across a course of study, and (c) that connections between classroom and workplace activities are clearly signposted for students.

Urban identity and colour : the case of Tirana, Albania

When an artist is put in charge of a city, he will use the town as his canvas. Edi Rama became Mayor of Tirana in 2000 and since them has undertaken an unusual and colourful renewal program for the Albania capital.

Collaborative inquiries into literacy, place and identity in changing policy contexts : implications for teacher development

In this chapter we describe a history of collaboration between university-based literacy researchers and school-based teachers in teacher development programs and practitioner inquiries designed to improve literacy outcomes for students living in low-socioeconomic circumstances. We consider how an inquiry stance has informed teachers working for social justice through curriculum and pedagogy designed to connect children’s developing literacy repertoires with their changing material, social and linguistic contexts. We use examples from the practices of two of our long-term teacher-collaborators to show what has been possible to achieve, even in radically different policy contexts, because of teachers’ continued commitment to themes of place and belonging, and language and identity.

Compilation of somatic mutations of the CDKN2 gene in human cancers : non-random distribution of base substitutions

The CDKN2 gene, encoding the cyclin-dependent kinase inhibitor p16, is a tumour suppressor gene that maps to chromosome band 9p21-p22. The most common mechanism of inactivation of this gene in human cancers is through homozygous deletion; however, in a smaller proportion of tumours and tumour cell lines intragenic mutations occur. In this study we have compiled a database of over 120 published point mutations in the CDKN2 gene from a wide variety of tumour types. A further 50 deletions, insertions, and splice mutations in CDKN2 have also been compiled. Furthermore, we have standardised the numbering of all mutations according to the full-length 156 amino acid form of p16. From this study we are able to define several hot spots, some of which occur at conserved residues within the ankyrin domains of p16. While many of the hotspots are shared by a number of cancers, the relative importance of each position varies, possibly reflecting the role of different carcinogens in the development of certain tumours. As reported previously, the mutational spectrum of CDKN2 in melanomas differs from that of internal malignancies and supports the involvement of UV in melanoma tumorigenesis. Notably, 52% of all substitutions in melanoma-derived samples occurred at just six nucleotide positions. Nonsense mutations comprise a comparatively high proportion of mutations present in the CDKN2 gene, and possible explanations for this are discussed.