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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
51

The role of keratan sulphate in the modulation of aggrecanase activity

Poon, C. J. January 2005 (has links)
Arthritis is a debilitating disease of the joints caused by the accelerated breakdown of cartilage, resulting in painful, swollen joints. Cartilage protects the joint by absorbing the shock that would otherwise be transferred directly to the underlying bone. One crucial component of cartilage is a specialised molecule known as aggrecan. Aggrecan consists of a core protein with three globular domains (G1, G2 and G3) and is modified with over one hundred highly sulphated glycosaminoglycan chains. Two types of glycosaminoglycans are substituted along the length of the protein, chondroitin sulphate and keratan sulphate. The glycosaminoglycans impart a highly negative charge to the tissue, giving it the ability to retain water and resist compressive forces. / Aggrecan is lost from cartilage following cleavage by aggrecanases. Too little aggrecan in cartilage destabilises the structural integrity of the tissue and is associated with arthritis. Of the five known aggrecanase cleavage sites, it is cleavage within the interglobular domain (IGD) between the G1 and G2 domains at NITEGE373 - 374ARGSVI that directly contributes to loss of aggrecan function. / The chondroitin sulphate and keratan sulphate located between the G2 and G3 domains is responsible for maintaining the biomechanical properties of aggrecan. The role of keratan sulphate within the G1-G2 domain is unknown, but it is not thought to be essential for aggrecan function. However the literature suggests a possible role of keratan sulphate in facilitating aggrecanase cleavage of NITEGE373 - 374ARGSVI in the IGD. The aim of my project was to examine the role of keratan sulphate in aggrecanase-mediated cleavage of aggrecan in the IGD. Three major goals have been accomplished in this thesis: 1) Identification of a cell type capable of sustained keratan sulphate synthesis. 2) Expression of a recombinant G1-G2 protein substituted with keratan sulphate (rG1-G2). 3) Demonstration that endogenous N-linked keratan sulphate is sufficient to potentiate aggrecanase cleavage of rG1-G2 in the IGD. / Cultured cells do not synthesise keratan sulphate. Therefore identifying a cell type, and culture conditions to maximise keratan sulphate synthesis, was a major undertaking. Conditions were identified which allowed for maximal keratan sulphate synthesis, albeit on a small scale, in primary bovine keratocytes. Using a Vaccinia virus expression system, recombinant G1-G2 was expressed in primary bovine keratocytes. / Analysis of the rG1-G2 revealed that it was substituted with 5 kDa of keratan sulphate. One important aspect of the study was that the keratan sulphate was all N-linked to the core protein. Subsequent aggrecanase digests, comparing substrates before and after removal of keratan sulphate, showed that aggrecanase cleavage was markedly more efficient when keratan sulphate was present. The results contained in this thesis add significantly to the established literature by providing a greater understanding of the mechanisms involved in aggrecanase-mediated cleavage of aggrecan and cartilage destruction. The results suggest that aggrecan substitution with N-linked keratan sulphate potentiates aggrecanase activity. The results from this study identify N-linked keratan sulphate as a possible target for the development of new drugs for the management of arthritis.
52

Chromosome fragile sites and very late DNA replication : implications for cytogenetics and the human cell cycle /

Widrow, Robert Jon. January 1998 (has links)
Thesis (Ph. D.)--University of Washington, 1998. / Vita. Includes bibliographical references (leaves [103]-137).
53

Lack of an early S phase delay following DNA cross-linking precedes P53-mediated G2 arrest and apoptosis in fanconi anemia cells /

Phelps, Randall Alan, January 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 83-112).
54

The role of Vpr in cell-cycle regulation by diverse primate lentiviruses /

Stivahtis, Gina Lynn. January 1999 (has links)
Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 92-115).
55

Factors affecting epithelial regeneration : with special reference to ascorbic acid and to pantothenic acid

Galloway, Nancy Mearns January 1948 (has links)
1. A brief historical introduction is given. It deals with the general features of wound healing in which epithelial participation is the dominant feature. 2. In Section A the influence of ascorbic acid on healing of skin wounds in rats is discussed. 3. Second wounds were inflicted at the same site as the initial wounds one month after the latter had healed. 4. In Section B the influence of ascorbic acid on healing of skin wounds in guinea pigs is investigated. 5. In order to discover the action ascorbic acid has on ear wounds, the tips of guinea pigs' ears were cut off. 6. The influence of ascorbic acid on the regeneration of corneal epithelium in guinea pigs is discussed. 7. The effect of ascorbic acid on healing of muco-periosteum was studied. 8. The influence of pantothenic acid on healing of skin wounds in rats was studied. 9. Pantothenic acid (Bepanthen-Salbe) ointment was applied directly to skin wounds.
56

Time to quit? : non-genetic heterogeneity in cell fate propensity after DNA damage

Campbell, Callum James January 2018 (has links)
Cellular checkpoints are typically considered to both facilitate the ordered execution of the cell cycle and to act as a barrier to oncogene driven cell cycles and the transmission of unresolved genetic lesions from one phase to the next. Furthermore, these mechanisms are also believed to underpin the responses of cells, both in normal and cancerous tissues, to those therapies that either directly or indirectly generate DNA damage. In recent studies however, it has become clear these checkpoints permit the passage of significant genomic aberrations into subsequent cell cycle phases and even descendant cells, and that heterogeneous responses are apparent amongst genetically identical cells. The consequences of this checkpoint ‘negligence’ remain relatively uncharacterised despite the importance of checkpoints in current models for how genomic instability is avoided in the face of ubiquitous DNA damage. Unresolved DNA damage is presumably inherited by subsequent cell cycle phases and descendant cells yet characterisation of the consequences of this has been relatively limited to date. I therefore utilised microscopy-based lineage tracing of cells expressing genetically encoded fluorescent sensors, particularly the Fluorescent Ubiquitination-based Cell Cycle Indicator (FUCCI) probes (Sakaue-Sawano et al., 2008), with semi-automated image analysis to characterise the response of single cells and their descendants to DNA lesions across multiple cell cycle generations. This approach, complemented by generational tracing by flow cytometry, permitted me to characterise the timing of cell fate determination in treated and descendant cells, the non-genetic heterogeneity in checkpoint responses and overall lineage behaviour, correlations between cells (similarly to Sandler et al., 2015) and cell cycle timing dependencies in the response to DNA damaging agents. With these single cell analytical approaches I show that the consequences of DNA damage on descendant cell fate is dramatic, suggesting checkpoint mechanisms may have consequences and even cooperate across phases and generations. U2OS cell lineages traced for three generations following the induction of DNA damage in the form of strand breaks showed greatly induced cell death in the daughters and granddaughters of DNA damaged cells, termed delayed death. Furthermore, lineage behaviour was characterised as highly heterogeneous in when and whether cell death occurred. Complementary flow cytometric approaches validated the findings in U2OS cells and suggested HeLa cells may show similar behaviour. These findings indicate that checkpoint models need to incorporate multigenerational behaviour in order to better describe the response of cells to DNA damage. Understanding the processes governing cell fate determination in descendant cells will impact upon our understanding of the development of genomic instability during carcinogenesis and how DNA-damaging chemotherapeutics drive cells to ‘quit’ the cell cycle.
57

Komunikační strategie Komerční banky, a.s. se zaměřením na Youngsters / Communication Strategy of Komerční banka, a.s. with a Focus on the Youngsters

Bartůňková, Eva January 2016 (has links)
Thesis explores communication strategy of Komerční banka, a.s. with a focus on the Youngsters. The aim of this thesis is an analysis of previous and current campaigns, corroborated by original research. The thesis comprises six chapters, the first two chapters dealing with theory, the rest dealing with empirical findings. The first chapter discusses the difference between marketing and commercial communication and kinds of commercial communication; the second chapter delves into the issue of communication strategy, its types and development. The third chapter consists of a presentation of Komerční banka, a.s. including an evaluation of the competition; the subsequent chapter discusses the characteristics of the G2 brand, its target group and includes an SWOT analysis. The content of the fifth chapter is a description of previous communication and of new communication campaign of the G2 brand. In the conclusion of the thesis, research results are assessed and future steps are recommended.
58

MPICH-G2

Grabner, René 02 June 2003 (has links)
The paper gives an overview on installation and usage of the Grid-enabled MPI implementation MPICH-G2. Performance results of MPICH-G2 in several environments are presented. / Die Arbeit gibt einen Überblick über die Installation und Nutzung der Grid-fähigen MPI-Implementation MPICH-G2. Performance-Ergebnisse von MPICH-G2 in verschiedenen Umgebungen werden gezeigt.
59

A RUNX-targeted gene switch-off approach modulates the BIRC5/PIF1-p21 pathway and reduces glioblastoma growth in mice / RUNXを標的とした遺伝子スイッチオフ法はBIRC5/PIF1-p21経路を介してマウスの膠芽腫の増殖を抑制する

Yamamoto(Hattori), Etsuko 23 March 2023 (has links)
京都大学 / 新制・課程博士 / 博士(医学) / 甲第24511号 / 医博第4953号 / 新制||医||1064(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 伊藤 貴浩, 教授 岩田 想, 教授 河本 宏 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
60

THE ROLE OF GAB2 PHOSPHORYLATION SITES IN HEMATOPOIETIC SIGNALING

Verma, Sheetal 17 May 2010 (has links)
No description available.

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