Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2009. / Härtill 3 uppsatser.

Thesis (Ph. D.)--Cornell University, August, 2006. / Vita. Includes bibliographical references (leaves 182-204).

Thesis (doctoral)--Umeå Universitet, 1985. / Added t.p. with thesis statement inserted. Includes bibliographical references (p. 35-41).

Thesis (Ph. D.)--University of Virginia, 2005. / Includes bibliographical references (leaves 158-161). Also available online through Digital Dissertations.

Directed cell migration is essential in both physiological and pathological situations. Many guidance cues have been extensively investigated in the past decades, to be able to regulate directional cell migration, including chemical, physiological and haptotactic cues. In the past years, we have focused on the roles of physiological electric field in the guidance of directed cell migration. It is well accepted that physiological electric fields exist both extracellularly and intracellularly with different functions, and interestingly, endogenous EFs exist in not only physiological but also pathological events. For instance, the existence of a small current in developing embryos which is also known as the endogenous electric field has been tested, such as the blastopore in Xenopus, chicken embryos, and etc. It has been also demonstrated that endogenous electric fields exist at the wound edges of injured cornea and skin. Physiological electric field is among many other guidance cues controlling an important cellular response – directed cell migration in response to stimuli, a phenomenon named electrotaxis or galvanotaxis. We and others have extensively demonstrated that physiological EFs could control directional cell migration, and that several signalling pathways are required for the regulation of such event. In the current study, we used Dictyostelium model to further explore the molecular and genetic mechanisms of how electrotaxis is controlled, by extensively investigating candidate molecules and genes in such regulation. We found that PI3K, PTEN and Ras signalling pathways are largely involved in the regulation of electrotaxis, Ras plays more dominant roles in this event in comparison with PI3K and PTEN, which only partially contributed towards the electrotactic response of the Dictyostelium cells. Asymmetric redistribution of signalling molecules are shown to play an essential role in the initiation and maintenance of the electrotactic response of the cells.

A Thesis Submitted to the Faculty of Medicine University of the Witwatersrand, Johannesburg for the Degree of Doctor of Philosophy, / The cell type exclusively dealt with in this thesis is the human blood neutrophil, which is also referred to in the text as polymorphonuclear leukocyte (PMN). The experimental work in this thesis has been accomplished using one immunological and a number of biochemical investigative techniques. The former is the Boyden technique (Boyden, 1962) for the quantitative assessment of leucocyte motility. / IT2018

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 98-102).

The aim of this study was to investigate the effects of various polysaccharides and their breakdown products on the proliferation and migration of cells involved in wound healing, both in vitro and in vivo, with the ultimate aim of developing a commercially viable collagen dressing containing an active polysaccharide fragment which would stimulate the wound healing response to such a degree that good quality and significantly faster healing would take place. Hyaluronic acid (HA), chondroitin sulphate (CS), heparin, Oxidised Regenerated Cellulose (ORC) and pectin were tested in this study. Some HA fragments and CS fragments significantly stimulated (p<O.05) the proliferation of Bovine Aortic Endothelial (BAEC) cells, although other HA or CS fragments were without effect. All HA and CS fragments tested also had no effect on the migration of L929 cells in the Boyden Chamber assay. Pectin stimulated the proliferation and migration of L929 cells, whereas, ORC 1 and heparin both suppressed proliferation (25% - 45% inhibition) of these cells but stimulated their migration. When injected subcutaneously into Polyvinyl alcohol sponges in the rat wound model at concentrations of 10 and 50J.1g/ml, heparin brought about an increased presence of granulation tissue in the wound after 10 days and 7 days respectively. These results indicate that structurally similar polysaccharides can have profoundly different effects on cell proliferation and migration, and thus have potential therapeutic use in guiding cell movement in wound healing.

This study concludes two parts. In the first part, we establish the model of the interaction between two cell populations following the concept of the random-walk, and assume the cell movement is constrained by space limitation primarily. In the other part, the interaction model is deduced from the concept of the flux motion, and the movement is constrained by space limitation, too. Furthermore, we analyze two models to obtain the behavior of two cell populations as time is close to the initial state and far into the future. / This study concludes two parts. In the first part, we establish the model of the interaction between two cell populations following the concept of the random-walk, and assume the cell movement is constrained by space limitation primarily. In the other part, the interaction model is deduced from the concept of the flux motion, and the movement is constrained by space limitation, too. Furthermore, we analyze two models to obtain the behavior of two cell populations as time is close to the initial state and far into the future.

Diss. (sammanfattning) Uppsala : Univ., 2003. / Härtill 4 uppsatser.