Margaret Watts

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The efficiency of 35 nitroaromatic and nitroheterocyclic compounds in radiosensitizing hypoxic Chinese Hamster cells in vitro was determined. The concentration C of the compound required to achieve an enhancement ratio of 1.6 was measured, and the redox and partition properties were quantified as the one-electron reduction potential at pH 7, E, and the(More)
A method for the isolation and long-term culture of human microvessel endothelial cells from mammary adipose tissue (HuMMEC) obtained at breast reduction surgery has been developed. Pure cultures of HuMMEC were isolated by sequential digestion of the fat with collagenase and trypsin followed by specific selection of microvessel fragments with Ulex europaeus(More)
Pancreatic islets exhibit bursting oscillations in response to elevated blood glucose. These oscillations are accompanied by oscillations in the free cytosolic Ca(2+) concentration (Cac ), which drives pulses of insulin secretion. Both islet Ca(2+) and metabolism oscillate, but there is some debate about their interrelationship. Recent experimental data(More)
A number of anti-cancer agents have been implicated in vascular toxicity. The effects have been attributed to direct drug toxicity towards endothelium. Little attention has been focussed on the interaction between anticancer drugs, endothelial cells and tumour secreted factors. It is well known that tumours can secrete factors such as vascular permeability(More)
Fifteen nitroaromatic and nitroheterocyclic compounds that can act as "radiosensitizers" were tested for their cytotoxicity toward hypoxic Chinese hamster V79 cells in vitro. The cytotoxicity increased markedly as the electron affinity, measured as a one-electron reduction potential, increased. Non-nitro-containing compounds of similar electron affinities(More)
Evidence from a number of laboratories suggests that membrane proteins may meditate the transport of physiologic fatty acids (FA) across cell membranes. However, actual transport of unbound free fatty acids (unbound FFA) from the aqueous phase on one side of a cell membrane to the aqueous phase on the other side has not been measured previously. In this(More)
The mechanism by which glucose induces insulin secretion in β-cells is fairly well understood. Despite years of research, however, the mechanism of glucagon secretion in α-cells is still not well established. It has been proposed that glucose regulates glucagon secretion by decreasing the conductance of either outward ATP-dependent potassium channels(More)
Average intracellular concentrations of five radiosensitizers in hamster fibroblast-like V79-379A cells in vitro were measured by high performance liquid chromatography, varying the extracellular pH (pHe) and estimating the apparent intracellular pH from the distribution of 5,5-dimethyloxazolidine-2,4-dione. The intracellular: extracellular concentration(More)