PubMed · 9644510
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1998-06-25. Calming ulcerative colitis.. https://pubmed.ncbi.nlm.nih.gov/9644510/
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A biomolecule-assisted simple technique has been developed for the spontaneous ordering of the Bi2S3 nanorods into snowflakelike superstructures in high yield under microwave-hydrothermal conditions. In this method, glutathione (GSH) is used as both an assembling agent and a sulfur source. By controlling the molar ratio between bismuth nitrate and glutathione as well as the synthetic temperature, several kinds of Bi2S3 one-dimensional nanomaterials such as snowflakelike structures, nanowires constructed of particles, short nanorods, and fine and long nanowires have been controllably synthesized.
A simple procedure for the determination of 210Pb in geological samples using liquid scintillation counting is presented. Following the acid digestion of the sample, the method uses sulphate precipitation for the radiochemical separation. Finally, lead oxalate is precipitated, and once re-dissolved, it is mixed with ULTIMA GOLD AB scintillator cocktail. The measurement is performed using a low-level LKB Quantulus 1220 spectrometer and the two-window technique. Calibration studies were performed to evaluate the interference of 210Bi in the 210Pb measurement. The method was tested on a geological reference sample, and gave satisfactory results and high reproducibility.
Although bismuth salts have been used for over two centuries for the treatment of various gastrointestinal disorders, the mechanism of their therapeutic action remains controversial. Because gastrins bind two trivalent ferric ions with high affinity, and because ferric ions are essential for the biological activity of glycine-extended gastrin 17, we have investigated the hypothesis that trivalent bismuth ions influence the biological activity of gastrins. Binding of bismuth ions to gastrins was measured by fluorescence quenching and NMR spectroscopy. The effects of bismuth ions on gastrin-stimulated biological activities were measured in inositol phosphate, cell proliferation, and cell migration assays. Fluorescence quenching experiments indicated that both glycine-extended and amidated gastrin 17 bound two bismuth ions. The NMR spectral changes observed on addition of bismuth ions revealed that Glu-7 acted as a ligand at the first bismuth ion binding site. In the presence of bismuth ions the ability of glycine-extended gastrin 17 to stimulate inositol phosphate production, cell proliferation, and cell migration was markedly reduced. In contrast, bismuth ions had little effect on the affinity of the CCK-2 receptor for amidated gastrin 17, or on the stimulation of inositol phosphate production by amidated gastrin 17. We conclude that bismuth ions may act, at least in part, by blocking the effects of glycine-extended gastrin 17 on cell proliferation and cell migration in the gastrointestinal tract. This is the first report of a specific inhibitory effect of bismuth ions on the action of a gastrointestinal hormone.