131,312 research outputs found
STUDIES ON THE EFFECTS OF LAMININ, E-8 FRAGMENT OF LAMININ AND SYNTHETIC LAMININ PEPTIDES PA22-2 AND YIGSR ON MATRIX METALLOPROTEINASES AND TISSUE INHIBITOR OF METALLOPROTEINASE EXPRESSION
No full textBASEMENT-MEMBRANE TYPE-IV COLLAGEN DEGRADATION - EVIDENCE FOR THE INVOLVEMENT OF A PROTEOLYTIC CASCADE INDEPENDENT OF METALLOPROTEINASES
No full textCurrent hypotheses suggest that both the plasmin system and metalloproteinases
are involved in tumor invasion of basement membrane. In
this study, we demonstrate that plasmin can directly degrade native and
denatured type IV collagen in solution as well as in tissue sections. Tumor
cell lines secreted plasminogen activators into culture supernatants that
activated exogenous plasminogen to degrade type IV collagen in zymograms
and to remove collagen IV immunoreactivity from tissue sections.
Inhibition of metalloproteinase activity in culture supernatants by EDTA
did not interfere with plasminogen-mediated type IV collagen degrada
tion. We propose that tumor cells possess a mechanism for the degra
dation of basement membrane type IV collagen, independent of metalloproteinases
but dependent on plasminogen conversion to plasmin
STUDIES ON THE ABILITY OF 65-KDA AND 92-KDA TUMOR-CELL GELATINASES TO DEGRADE TYPE-IV COLLAGEN
No full textTwo major gelatinolytic metalloproteinases (gelatinases)
of 66 kDa and 92 kDa were purified from a
tumor cell line. Analysis of collagen degradation
showed that native full-length Engelbreth-Holm-
Swarm (EHS) type IV collagen was not cleaved by the
purified gelatinases under conditions where native
pepsin-extracted human placental type IV and V collagen
and heat-denatured collagens were markedly
degraded. However, EHS type IV collagen degradation
was noted at 37 OC, i.e. under conditions that would
favor denaturation of the collagen molecule in solution.
The pattern of degradation of human placental type IV
and V collagen appeared similar for both gelatinases.
Zymogram analysis of gelatinase activity in the absence
of sodium dodecyl sulfate (SDS) (to eliminate
possible SDS-mediated denaturation of type IV collagen)
confirmed the inability of 65 and 92-kDa gelatinases
to degrade native full-length EHS type IV collagen.
Under the same conditions and in SDS-polyacrylamide
gel electrophoresis zymograms the gelatinases
degraded pepsin-predigested EHS type IV collagen and
pepsin-extracted human placental type IV collagen.
These data suggest that the 65- and 92-kDa tumor
cell gelatinases are not true type IV collagenases. Their
ability to degrade pepsin-solubilized, or denatured,
type IV collagen suggests a specificity for telopeptide
precleaved or conformationally altered forms of this
molecule.
Type IV collagen degradatio
Evidence for a novel gene associated with low tumor metastatic potential.
No full textWe describe a gene, NM23, that is associated with the tumor metastatic process. NM23 RNA levels were highest in cells and tumors of relatively low metastatic potential in two experimental systems: (1) murine K-1735 melanoma cell lines, in which the gene was identified, and (2) N-nitroso-N-methylurea-induced rat mammary carcinomas. NM23 RNA levels did not correlate with cell sensitivity to host immunological responses and may, therefore, be associated with intrinsic aggressiveness. The predicted carboxy-terminal protein sequence encoded by the pNM23 cDNA clone is novel compared with Genebank animal, bacterial, and viral sequences
IDENTIFICATION OF THE 72-KDA (MMP-2) AND 92-KDA (MMP-9) GELATINASE TYPE-IV COLLAGENASE IN PREPARATIONS OF LAMININ AND MATRIGEL(TM)
No full textRAS LEVELS AND METALLOPROTEINASE ACTIVITY IN NORMAL VERSUS NEOPLASTIC RAT MAMMARY TISSUES
No full textThe construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
Up-Create Cultural Heritage 59th Annual Art Exhibition–Session: Interviews
No full textGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Situated Architectur
Keeping up With...Patron Driven Acquisitions
No full textKeeping Up With… is an online current awareness publication from the Association of College and Research Libraries (ACRL) featuring concise briefs on trends in academic librarianship and higher education. Each edition focuses on a single issue including an introduction to the topic and summaries of key points, including implications for academic libraries. © Copyright 1997-2014, American Library AssociationThis document may be reprinted and distributed for non-commercial and educational purposes only, and not for resale. No resale use may be made of material on this website at any time. All other rights reserved.abstract: Historically, approaches to collection development in libraries relied on the subjective determination of librarians or outside vendors to select the material most suitable to address patron needs. Favoring broad strokes, acquisition policy relied on major publishers and sought to cover general subject areas. Several factors prompted a shift in approach to collection development, including reductions to staffing and budgets, but more importantly technological advancements and the proliferation of e-books caused the reevaluation of the resources patrons accessed and whether the collection accomplished its goal of satisfying their needs. The practice of patron driven acquisition (PDA) refines the broad strokes of acquisition to directly address the demands of patrons while managing costs by purchasing high use material, renting sparsely used titles and paying nothing for titles with no demand.
PDA involves the inclusion of bibliographic records to the catalog for titles the library does not own and permits the patron an opportunity to initiate a purchase. Beyond the practical implications of managing costs and liberating staff time, the PDA model provides patrons easier and quicker access to the widest range of information possible. The service model of populating a collection to protect against the possibility of patrons requiring access is increasingly unsustainable. Although not without its challenges, allowing the patron to provide a collaborative role with librarians in developing a collection serves to manage costs and streamlines the process of creating a collection which best addresses the needs of a constituency.tableOfContents: Just-in-Case versus Just-in-Time: A Paradigm Shift in Collection Development
The Evolving Methodology of Patron-Driven Acquisition and its Impact Upon Circulation Rates
Implementing Patron-Driven Acquisition and Establishing a Viable Approval Plan
Patron-Driven Acquisition and e-Books: Benefits and Challenges
A Continued Role for Librarians
Recommended Resources and Reading
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