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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

Epidermal growth factor, α-transforming growth factor and breast cancer

Porteous, C. January 1987 (has links)
Evidence exists that epidermal growth factor (EGF) and alpha transforming growth factor (αTGF) are important in breast cancer. An inverse relationship between epidermal growth factor receptor (EGF-R) and oestrogen receptor (ER) has been reported by some, (1) but not all workers (2). The aim in this thesis was to develop assays to measure, levels of EGF, and determine EGF-R status in human breast tumours. These results were then correlated with each other, with ER and node status and histological grade (Bloom & Richardson). An additional aim in this thesis was to develop a source of αTGF in conditioned median (CM) from a transformed cell line. After extraction and purification, the αTGF was intended for use as an immunogen to produce a polyclonal antiserum which could be used in either an RIA or ELISA. EGF was measured by a radioimmunoassay (RIA) utilising a rabbit antimouse EGF antiserum. This assay (sensitivity 0.1ng/ml) was demonstrated to have no cross reactivity with αTGF. The EGF-R assay was similar to that described by Sainsbury. (1) In a series of 88 human breast tumours 47 (53.4%) were found to contain extractable EGF. Forty eight (54.5%) were EGF-R positive and 39 (44.3%) were ER positive. A direct relationship between EGF and ER+ ve status was found (p < 0.01). Significantly higher levels of EGF were extracted from ER+ ve tumours (p = 0.049) compared with that from ER-ve tumours. However no relationship between EGF-R and EGF or ER status was found, or between EGF levels and histological grade or node status. A suitable cell line which produced αTGF, was obtained and culture conditions optimised. Alpha-TGF was assayed by a radioreceptor assay which utilised a cell line rich in EGF-R (A431). Extraction of αTGF was based on the principles of molecular grading by gel filtration (Sephadex G50), and ion exchange (Sephadex CM C25). By this process the αTGF was purified and separated it from any EGF present. By this method 20μg of αTGF was produced from 61t of CM. 1) Sainsbury JRC, Farndon JR, Serbet GV, Harris AL. Epidermal-growth-factor-receptors and oestrogen receptors in human breast cancer. Lancet 1985; <i>1</i>: 364-368. 2) Fitzpatrick SL, Brightwell J, Wattliff JL, Barrows GH, Schultz GS. Epidermal growth factor binding by breast tumour biopsies and relationship to oestrogen receptor and progestin receptor levels. Cancer Res 1984; <i>44</i>: 3448-3453.
52

Characterization of the biological properties of FGF-9

Seet, Li Fong January 1996 (has links)
The fibroblast growth factor family of polypeptides currently consists of nine structurally-related members. Cloning of the mouse homologue of the latest reported member of the family, FGF-9, is described in this study. Mouse Fgf9 exhibits a high level of sequence conservation with the human, rat and Xenopus counterparts. Of note is the lack of a hydrophobic signal peptide at the N-terminus of the coding sequence. The protein, however, appeared to be secreted by producer cells since a significant quantity of the protein could be purified from the culture supernatant of transfected cells. Members of the FGF family are known to bind to cell surface tyrosine kinase receptors (FGFRs) to elicit a variety of physiological responses. These receptors themselves form a family of four structurally-related tyrosine kinases and each FGF member commonly has the ability to bind several members of the FGFR family. By using in vitro plate binding assays, FGF-9 is shown in this study to bind specifically to two FGFR members: FGFR2b and FGFR3c. To further study the potential functional role of FGF-9, its expression pattern in the mouse embryo was examined by both RNase protection and RNA in situ hybridization analyses. The transcript was detected in a variety of embryonic tissues: the germinal epithelium of the central nervous system, the mesonephric cords, the somites, the gut primordia and the developing eye and ear, suggesting that the gene may have multiple roles during development. In addition, the potential involvement of FGF-9 in mediating adult brain functions was examined by double RNA in situ hybridization analysis of the distribution of both Fgf9 and Fgfr3 transcripts in the adult mouse brain. Most apparent areas of co-localization are the olfactory bulb and cerebral cortex. The two transcripts are also shown to have distinct distribution patterns in the cerebellum.
53

Cytokine and growth factor regulation of murine macrophage scavenger receptor expression and function

De Villiers, Willem Johan Simon January 1995 (has links)
The macrophage (Mφ) foam cell in the atherosclerotic plaque microenvironment is subjected to cytokines and growth factors secreted by smooth muscle cells (SMCs), endothelial cells (ECs), platelets and lesional Mφ themselves. This thesis examines the effects of some of these soluble factors on a murine macrophage membrane molecule, the macrophage scavenger receptor (MSR), considered pivotal in foam cell formation and atherogenesis. Macrophage Colony-stimulating factor (MCSF) enhances MSR expression and functional activity (including MSR-dependent adhesion) in elicited peritoneal Mφ markedly and selectively. The T lymphocyte products, Th1 (interferon-gamma(IFN-γ)) and Th2 (chiefly interleukin-4 (IL-4)) cytokines, have divergent effects with IL-4 upregulating and IFN-γ either maintaining or downregulating MSR status. IL-4 induced MSR microheterogeneity is due to changes in N-linked glycosylation, specifically sialylation and may be physiologically significant. In contrast to interleukin-10 (IL-10), transforming growth factor-beta (TGF-β) inhibits MSR upregulation, also when produced endogenously. TGF-β is as potent an inhibitor of MSR function as M-CSF is a stimulator. A cleaved truncated soluble form of MSR which lacks the cytoplasmic domain is present, by immunochemical assays, in culture supernatants. M-CSF increases soluble MSR release in vitro which is functionally active. Following upregulation of MSR surface expression in transfected CHO cells by prolonged culture, a modest MSR-dependent contribution to adhesion becomes apparent. To determine a possible adhesionpromoting region in the MSR, the binding site of mAb 2F8 was mapped using a series of MSR truncation mutants, and localized to residues 183 to 197 in the proximal cchelical coiled-coil domain. Morphological evidence, obtained by confocal and electron microscopy, supports an adhesion role for the MSR in primary Mφ and transfected CHO cells. MSR expression is prominently directed to the adherent surface and its distribution is restricted to cellular contact areas with the substratum. Organs and atherosclerotic lesions from mice deficient in M-CSF (osteopetrotic) and apolipoprotein E were examined to determine the effects of M-CSF on Mφ phenotype (including MSR expression) and lesion development in vivo. Though severely hypercholesterolemic, doubly deficient mice are protected against atherosclerosis and exhibit fewer Mφ and low MSR expression on remaining M-CSF independent populations. Prominent hepatic lipid accumulation suggests a crucial M-CSF dependent role for Kupffer cells in lipoprotein uptake, transfer to hepatocytes and biliary excretion of cholesterol. Regulation of MSR activity may therefore be important for the recruitment of Mφ into the arterial wall and, at the post-endothelial stage, to anchor Mφ at specific locations, thus favouring foam cell formation.
54

Fibroblast growth factors influence collective cell behavior during mesoderm migration

McMahon, Amy J. Stathopoulos, Angelike Fraser, Scott E., January 1900 (has links)
Thesis (Ph. D.) -- California Institute of Technology, 2010. / Title from home page (viewed 03/25/2010). Advisor and committee chair names found in the thesis' metadata record in the digital repository. Includes bibliographical references.
55

Exploring the role of fibroblast growth factor (FGF) signaling in mouse lens fiber differentiation through tissue-specific disruption of FGF receptor gene family

Zhao, Haotian, January 2004 (has links)
Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xii, 203 p.; also includes graphics (some col.) Includes bibliographical references (p. 179-203). Available online via OhioLINK's ETD Center
56

High-resolution structures of the proteins human kallikrein 6 and human fibroblast growth factor-1 structure and function relationships /

Bernett, Matthew John. Blaber, Michael. January 2004 (has links)
Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Michael Blaber, Florida State University, College of Arts and Sciences, Dept. of Chemistry and Biochemistry. Title and description from dissertation home page (viewed June 1, 2005). Document formatted into pages; contains xiii, 110 pages. Includes bibliographical references.
57

The role of extracellular zinc in IGF-1 receptor expression and proliferation in a normal and squamous cell carcinoma cell line /

Thornton, William H. January 1999 (has links)
Thesis (Ph. D.)--University of Missouri--Columbia, 1999. / "May 1999." Typescript. Vita. Includes bibliographical references (leaves 111-127). Also available on the Internet.
58

Blood brain-derived neurotrophic factor (BDNF) expression in normal humans and schizophrenic patients

Liu, Ping, January 2004 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2004. / Title proper from title frame. Also available in printed format.
59

Smad2 regulation by heterogeneous nuclear ribonucleoprotein A1 /

Hung, Anthony. January 2009 (has links)
Thesis (M.Sc.)--York University, 2009. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 108-139). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR51542
60

The upregulation of VEGFR1 by mechanical stretch and shear stress in endothelial cells /

Fudalewski, Tomasz S. January 2009 (has links)
Thesis (M.Sc.)--York University, 2009. Graduate Programme in Kinesiology. / Typescript. Includes bibliographical references (leaves 75-109). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR51528

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