Thesis (Ph. D.)--University of Wisconsin--Madison, 1963. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 66-72).

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Fluorescein angiography is used in the routine clinical examination of patients with suspected retinopathy. Conventional angiography involves the photography of a subject's retina after injection with a small quantity of fluorescein dye. In this study, we have developed a technique to measure the movement of this dye through the retinal circulation. Two implementations of angiography have been investigated - conventional photography and capture of the angiographic frames using the scanning laser ophthalmoscope (SLO). After pre-processing to remove any noise present, the images are registered via cross-correlation to remove the effects of patient movement. A gamma variate plus 2nd order polynomial dye-dilution model is then fitted to the temporal change in fluorescein intensity at each point in the retina. Parameters are extracted from these fitted curves and their values combined to form functional images of the retinal circulation. A total of 16 angiograms of varying quality have been analysed using this technique. A distinctive filling pattern has been detected in the parametric images of the normal angiograms analysed, indicating a preferential flow of fluorescein, and hence blood, to the macula region of the retina. A number of abnormal angiograms were also analysed and the time to maximum images of these patients showed good agreement with their various pathologies. This included identifying occluded vessels, areas of ischaemia and oedema, as well as more subtle features such as leakage and microaneurysms. The generation of functional parametric images from fluorescein angiograms enables various aspects of the retinal circulation to be quantified. The technique offers a potential aid to diagnosis enabling the onset of retinopathy to be detected and its progression closely monitored.

A series of fluorescein and rosamine derivatives have been prepared and their spectroscopical properties analyzed to determine their usefulness as donor and/or acceptors in "through-bond" energy transfer systems. Such new systems have been tailored to possess higher quantum yields, increased water solubility and higher pH independence. Some of these compounds have also been designed with handles for bioconjugation for use in intracellular imaging. The syntheses of most of these compounds have been optimized to afford higher yields in a multigram scale. Single molecule studies on a fluorescein/rosamine cassette are also reported.

Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 137-152). Also available in electronic version.

Thesis--Amsterdam. / Summary in English. Bibliography: p. 96-100.

Thesis--University of Oklahoma. / Bibliography: leaves 62-63.

Thesis (M.Sc.(Water Utilisation))--University of Pretoria, 2001. / Summaries in Afrikaans and English. Includes bibliographical references.

Purpose: Solution-induced corneal staining (SICS) has been the subject of much debate in the clinical literature. While it has been suggested that this form of staining indicates toxicity of the cornea, microscopy studies have suggested that cells treated with multi-purpose solutions (MPS) known to produce SICS in vivo are undamaged. There is further debate in the literature as to whether or not sodium fluorescein (‘fluorescein’) actually enters epithelial cells or not. The aim of this work was to investigate the cellular mechanisms involved in SICS by developing an in vitro cell culture model to mimic the clinical presentation of this phenomenon. Methods: An in vitro model of SICS was developed using cultured cells that were exposed overnight to ReNu MultiPlus® (Bausch + Lomb) MPS. After addition of fluorescein, cells were imaged using an automated fluorescence microscope. Hyperfluorescent cells were identified using predetermined threshold of intensity in fluorescence microscope, and confocal microscopy was used to investigate where fluorescein was situated within the cells. The extent of cell toxicity was assessed using propidium iodide and Annexin V. In order to examine the contribution of passive and active transport mechanisms in fluorescein uptake and release, levels of hyperfluorescent staining were measured at 37°C and 4°C. In all described experiments, fluorescein staining was expressed by the proportion of hyperfluorescent cells in the total cells. Results: All cultured cells readily took up fluorescein at room temperature, however a sub-population of cells stained more intensely with fluorescein. These cells were termed ‘hyperfluorescent’ cells. Exposure to ReNu MultiPlus® resulted in a significant increase in the proportion of hyperfluorescent cells compared with control cells. In addition, the staining profiles of individual cells showed no correlation between cell death and hyperfluorescence. The data also showed that hyperfluorescence did not occur extensively in deliberately lysed cells.Addition of fluorescein to the cells at 4°C resulted in very low levels of hyperfluorescence compared to high levels at 37°C. Fluorescein was rapidly released from cells at 37°C but not from those at 4°C. Conclusion: In this work, an effective in vitro model of SICS was developed in order to provide a better understanding of the mechanisms involved in fluorescein staining. This work suggests that corneal fluorescein staining may reflect a simple cellular uptake of fluorescein. Levels of staining in the cells appear to be unrelated to cellular toxicity or cell damage. Staining appears to occur in the cytoplasm and the nucleus of the cells. Finally, fluorescein uptake and release are likely to occur through active transports mechanisms.

This thesis is concerned with the development of a compact, sensitive and reliable instrument for determination of the polarization of fluorescence of fluorescein tagged molecules in solution. The instrument as designed and constructed differs from others (2,3,4,5,6,8,9). The difference is that all of its optical system is aligned on a single axis. This was accomplished by the use of an ellipsoidal mirror positioned between the excitation source and the phototube fluorescence signal receiver. In addition, the excitation source, a 45 watt tungsten-iodide light was electronically regulated to control the intensity. Two types of determinations were made to verify the performance of the instrument. The first was the absolute sensitivity to varying fluorescein concentrations. Concentrations of fluorescein in 0.1 molar sodium phosphate buffer were prepared ranging from 10-6 molar to 10-11 molar. After the minimum detectable concentration was determined, five runs on samples of each concentration from the minimum detectable to 10-6 were made. The second check was for the sensitivity and linearity of the system in the measurement of polarization. Solutions of glycerol ranging from 62% to 90% were prepared with 10-6 molar fluorescein concentration. The data from the fluorescein sensitivity and polarization runs were averaged and the averages plotted on linear paper. In each case the instrument exhibited excellent linear response and reasonable standard deviation.