Modular system for fluorescence microspectroscopy has been developed by assembling fluorescence confocal microscope and spectral unit based on liquid cristal tunable filter, which enable us to acquire images at different wavelengths. The system enables spectral identification of particles, which are smaller than the wavelength of fluorescent light, as well as spatially-resolved analysis of local molecular environment from spatially dependent fluorescent emmission spectra. The system has been applied to trace the nanoparticles passing the cancer cell membranes. On the other hand, the same system has been used in our study for dentin analysis, especially for determination of dentin channels orientation, which has been characterized via fluorescent probes, entrapped into 100 nm liposomes to prevent free diffusion into porous dentin from dentin channels.
Twenty-four BALB/c mice were orally inoculated with 10(8) CFU Escherichia coli ATCC 25922 and euthanized 2.5, 7, 13 and 25h post-inoculation. The levels of organ nitric oxide (NO) in lungs, liver, kidneys and brain, and plasma endotoxin, TNF-alpha and nitrite/nitrate (NO(x)) were compared to those found in sham-inoculated mice, to evaluate systemic host-response to a low-level oral exposure to Gram-negative bacteria. Organ NO and plasma TNF-alpha levels were higher in E. coli-inoculated animals, but no differences were detected in plasma endotoxin levels and NO(x) for any of the animal groups. Single oral gavage with live E. coli stimulates an early systemic immune response in clinically healthy mice as evidenced by increased plasma TNF-alpha and organ NO levels.