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Cell surface receptors such as adhesion molecules and connexins are involved in interactions between cells and their surroundings. They play important roles in the normal function of healthy tissues and in the responses of cells to injury. In many cases aberrant repair mechanisms are thought to result in disease and this thesis will assess the expression of cell adhesion molecules (principally the pi integrins) and the connexin43 gap junction protein in normal and diseased kidney The expression of pi integrins on normal human mesangial cells was localised using the alkaline phosphatase anti-alkaline phosphatase immunochemical technique (APAAP) and Western blotting. Expression of mRNA coding for integrins was also assessed using reverse-transcription polymerase chain reaction (RT-PCR). Human mesangial cells in culture expressed the a2, a3, av, pi av and P3 integrin chains. Messenger RNA was detected for these integrin subunits plus the al, a4, a5 and a6 chains. Normal human kidney sections were stained using APAAP and monoclonal antibodies towards a wide range of integrin chains. Within the glomerulus, mesangial cells express al, a2 and pi, epithelial cells a3, av and pi and endothelial cells al, a5 and pi. Tubules express a2, a3, a6, av and pi and the interstitium al and pi. In renal biopsies from patients with IgA disease the main alterations in integrin expression were upregulation of a2, a3, av and pi on damaged tubules, with increased pi expression and de novo a5 and av staining within areas of interstitial damage. These changes were replicated in a wide range of other renal pathologies and correlate with the degree of tubulointerstitial histological damage. Connexin43 (Cx43) is distributed extensively on normal human kidney, particularly on glomerular epithelial cells and intra- and extra-glomerular endothelium. Human mesangial cells in vitro express Cx43 protein and its coding mRNA. There is, however, no expression of Cx43 by the mesangium in vivo. In biopsies from patients with inflammatory renal disease there is strong expression of Cx43 on infiltrating inflammatory cells, in areas of interstitial damage and on damaged tubules. The pattern of Cx43 expression in inflammatory renal disease was very similar to that of intercellular cell adhesion molecule-1 and vascular cell adhesion molecule-1. The work in this thesis has demonstrated the large repertoire of cell surface receptors expressed on normal kidney. The principal alterations in diseased kidney are found within the tubulointerstitum. The potential relevance of these changes in the pathogenesis of renal disease are discussed and possible future avenues of research are suggested.

Twelve isolates of Ichthyophthirius multifiliis were successfully established and maintained by serial passage through naïve carp, for a maximum of 39 laboratory cycles. The management system employed was such that large numbers of the parasite were available for all investigations. The ability to induce exit of immature trophonts through media incubation was used to confirm events in the initial stages of host colonisation. The normal course of primary infection was also established providing useful criteria for assessing success of the in vitro systems tested. Survival of both theronts and tomonts within selected monophasic media was investigated. Theronts in Eagles Minimum Essential medium (EMEM), survived and were viable for 120 hours, 72 hours longer than water controls. No further development of the theronts was observed. Tomonts also demonstrated an increased survival time in comparison to the controls with tomites surviving within the cyst for 22 days within EMEM-S media diluted 50:50 with sterile distilled water. Division of tomonts was identified as being precystic, post divisional cystic or cystic, and the frequency of such divisions was dependent upon dilution of media. Sterile viable theronts were recovered at 168h from tomonts that had been incubated within EMEM diluted 30:70 with distilled water. Delayed encystment was achieved by incubation in concentrated media, theront production being delayed for 96h, 72h later than seen in the aquatic environment. Cultured cell monolayers were used as associates within culture systems. Behaviour of theronts on introduction into the culture systems indicated recognition of the cultured tissue as potential host material, sustained contact of up to l20hours was observed between the introduced parasite and cells. However, no developmental markers were identified within the cultured parasite and no significant growth was achieved. Attempts to simulate the situation in vivo by use of multilayered systems and crude cell explants were also unsuccessful. Transmission electron microscopy of the parasite within a cell aggregate system was undertaken at daily intervals up to 120h providing evidence that the parasite was attempting to gain nutrients by phagocytosis. However, increased vacuolation of the parasite during the period of culture was clearly evident leading eventually to parasite death. The significance of the results is discussed in relation to the normal course of infection and the future promise of a long term culture method for this important pathogen.

by Alexandra M. Leung. / Thesis (M. Phil.)--Chinese University of Hong Kong, 1981. / Bibliography: leaves 208-224.

by Chun-Ping Li. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1989. / Bibliography: leaves 135-159.

The field of biomaterials has seen huge development over the past decade with enormous efforts invested in discovering materials with improved biocompatibility, application and versatility. Polymers can display many properties that make them ideal biomaterials, such as their potential flexibility, low weight, low cost and biodegradability. Moreover, they can be prepared in a wide variety of compositions and forms and be readily fabricated into various shapes and structures. Polymer microarrays represent an efficient high-throughput platform for the screening and discovery of new materials compared to conventional assays with advantages such as high-density screening, internal consistency of assays and the requirement for only small quantities of material. The first part of this thesis describes work in the area of diabetes research with a focus on how dysfunctional β-cells could be replaced by the transplantation of β-cells obtained from pluripotent stem cells. To achieve this aim, high numbers of β-cells are required. A polymer microarray screening approach was used to identify a number of polymers that promoted the attachment of pancreatic progenitor cells and enhanced cell proliferation. Multiple scale-up fabrication techniques were assessed to establish the most suitable approach and surface for long term cell culture leading to the obtainment of reproducible in situ polymerised polymer layers with enhanced binding properties toward pancreatic progenitor cells. These surfaces have the potential to support cell adhesion and proliferation and could find potential use in the industrial sector to increase the production of pancreatic progenitor cells in vitro. In the second part, efforts were made to gain a better understanding of the maturation of β-cells and their behaviour, with the development of 3D hydrogels based on the previously identified polymers. In this scenario, parameters such as stiffness and porosity were evaluated to identify the best environmental conditions to support 3D cell culturing of pancreatic progenitor cells. Several approaches were tested to generate scaffolds with suitable stiffness and porosity leading to the obtainment of scaffolds based on the previously identified polymer composition and with controlled porosity and stiffness. These scaffolds could represent a suitable environment to allow a better understanding of cell organisation and regulation. In a third avenue of work, arrays of 3D biocompatible materials, which were tailored for varying elasticity, hardness, and porosity (to provide the necessary physical cues to control cellular functions) were fabricated. In this chapter, details of the development of an array of eighty 3D double-network hydrogel features are reported. The array features can be produced as single or double networks and modulated in terms of stiffness, viscoelasticity and porosity to assess cell response to materials with a wide range of properties. The final part of the thesis describes the development and screening of polymeric materials to allow a better understanding of cell–surface interactions with various cell types. To investigate the correlation between cell attachment and the nature of the polymer, a series of random and block copolymers were synthesised and examined for their abilities to attach and support the growth of human cervical cancer cells (HeLa) and human embryonic kidney cells (HEK293T), with attachment modelled on monomer ratios, arrangement, and polymer chain length. The results of this screening showed differences between block copolymers and random copolymers in cell adhesion and provide interesting insight into the improvement of polymer coatings for cell culture.

Doctor of Philosophy(PhD) / The present study deals with the synthesis, characterization, determination of anticancer activity of three mononuclear trans-planaraminepalladium(II) complexes code named TH5, TH6 and TH7 and three trinuclear complexes code named TH1, TH8 and TH14. The activity of the compounds against human cancer cell lines: A2780, A2780cisR and A2780ZD0473R, cell uptake, DNA-binding and nature of interaction with pBR322 plasmid DNA have been determined. Whereas cisplatin binds with DNA forming mainly intrastrand GG adduct that causes local bending of a DNA strand, TH5, TH6, TH7, TH1 and TH8 bind with DNA forming mainly interstrand GG adducts that causes more of a global change in DNA conformation. Although TH5, TH6 and TH7 each have two substituted pyridine ligands in a trans-geometry (3-hydroxypyridine in TH5, 2-hydroxypyridine in TH6 and 4-hydroxypyridine in TH7), the compounds differ in their activity against ovarian cancer cell lines, indicating that non-covalent interactions involving the hydroxyl group may be playing a significant role in activity of the compounds. Among trinuclear complexes TH1 is found to be significantly more active than cisplatin. It is actually twice as active as cisplatin against the parent cell line A2780, thirteen times as active as cisplatin against the cisplatin-resistant cell line A2780cisR and 11.5 times as active as cisplatin against the cell line A2780ZD0473R. Whereas the resistance factor for cisplatin as applied to the cell lines A2780 and A2780cisR cell lines is 12.9 that for TH1 is 1.98. The results suggest that TH1 has been able to significantly overcome resistance operating in A2780cisR cell line. The compound is soluble in water so that it may be taken orally. Provided it has favourable toxicity profile, TH1 has the potential to be developed into a highly active anticancer drug with a wider spectrum of activity than cisplatin. Although platinum drugs use a shot-gun approach to kill cancerous cells, widespread use in the clinic and increasing volume of their sale indicate that even in the genomic age, there is still need for shot-gun drugs in the clinic.

Thesis (M.S.)--University of Nevada, Reno, 2005. / "December, 2005." Includes bibliographical references (leaves 50-53). Online version available on the World Wide Web.

Graduation date: 1994

Primary cultures of stromal-vascular (S-V) cells from adipose tissue were used to investigate the regulation of preadipocyte development. Differentiation of S-V cells was found to be under hormonal control. Insulin and glucocorticoids are essential for S-V cell differentiation in culture. S-V cells from both newborn and mature pig adipose tissue and sera from both ages were used to examine the effect of age on preadipocyte development. S-V cells from newborn pigs replicated faster and appeared more responsive to serum borne factors influencing S-V cell growth and development in culture. Serum source (newborn vs mature) did not affect differentiation of S-V cells from newborn or mature pig adipose tissue. When sera from fed or fasted pigs were used to culture newborn pig S-V cells, fasted pig sera stimulated greater differentiation and decreased cell replication as indicated by DNA content of rat S-V cell culture. Lean pig serum compared to obese pig serum, increased differentiation activity in culture of S-V cells an effect which may be influenced by sex. When sera from rat and pig were subjected to gel filtration fractionation on Sephacryl S-200 column, the elution profiles of both sera were similar. Rat serum contained six additional peaks (280 nm) not present in pig serum. Rat serum fraction two (apparent molecular size 67-150 kD) promoted greater differentiation of S-V cells than other rat serum fractions or pig serum fraction two. Fraction three (apparent molecular size 17-43 kD) of both sera inhibited differentiation and lipid filling in cultures of S-V cells but only rat fraction three promoted cell proliferation. Rat and pig S-V cells have different morphology when differentiated. Differentiated rat S-V cells appeared as individual cells when cultured in serum free or serum supplemented medium while differentiated pig S-V cells appeared as individual cells in serum free medium and as a tight cluster of cells in serum supplemented medium. Both cells responded differently to sera obtained from pigs of differing ages and development of rat S-V cells was influenced by anatomic site. / Graduation date: 1992