Astrocytes, Cytokines, Flow Cytometry, Galactosidases, Humans, Indicators and Reagents, Intercellular Adhesion Molecule-1, Interferon-gamma, Interleukin-1, Luciferases, Microscopy, Fluorescence, NF-kappa B, RNA, Ribonucleases, Transfection, Tumor Necrosis Factor-alpha, Up-Regulation