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A whole-field time-domain fluorescence lifetime imaging (FLIM) microscope with the capability to perform optical sectioning is described. The excitation source is a mode-locked Ti:Sapphire laser that is regeneratively amplified and frequency doubled to 415 nm. Time-gated fluorescence intensity images at increasing delays after excitation are acquired using(More)
We describe a novel whole-field fluorescence lifetime imaging system, based on a time-gated image intensifier and a solid-state laser oscillator-amplifier, that images lifetime differences of less than 10 ps. This system was successfully applied to discrimination between biological tissue constituents.
Conventional analyses of fluorescence lifetime measurements resolve the fluorescence decay profile in terms of discrete exponential components with distinct lifetimes. In complex, heterogeneous biological samples such as tissue, multi-exponential decay functions can appear to provide a better fit to fluorescence decay data than the assumption of a(More)
Endothelial cells express a cell surface co-receptor for plasminogen and tissue plasminogen activator (t-PA) which we recently identified as annexin II (Hajjar, K. A., Jacovina, A. T., and Chacko, J. (1994) J. Biol. Chem. 269, 21191-21197). This protein enhances the catalytic efficiency of t-PA-dependent plasmin generation by 60-fold (Cesarman, G. M.,(More)
The use of short-term cytotoxicity assays for the initial screening of chemicals not only aids in establishing priorities for the selection of chemicals that should be tested in vivo, but also decreases the time in which potential toxicants can be valued. Rainbow trout primary skin epithelial cell cultures are one such assay. Rainbow trout primary skin cell(More)
This study investigates protein synthesis, following exposure to sub-lethal Cu, in rainbow trout in vivo and in vitro. The investigation has two aims: to determine if perturbations in protein synthesis, compared with other physiological changes, are a biomarker of Cu pollution and to evaluate the most productive role of cellular models in ecotoxicology.(More)
In adult male rats fed on a cholesterol-free synthetic diet, plasma cholesterol concentrations were lowest with oat bran, intermediate with cellulose and highest with wheat bran. Plasma triacylglycerols (TAG) were similar with wheat bran and cellulose but higher with oat bran. The concentrations and pools of caecal volatile fatty acids (VFA) were lowest(More)