S100B expression in and effects on microglia

We evaluated the intracellular and extracellular biological role of S100B protein with respect to microglia. S100B, which belongs to the multigenic family of Ca2+-binding proteins, is abundant in astrocytes where it is found diffusely in the cytoplasm and is associated with membranes and cytoskeleton constituents. S100B protein is also secreted by astrocytes and acts on these cells to stimulate nitric oxide secretion in an autocrine manner. However, little is known about the relationship between S100B and microglia. To address this issue, we used primary microglia from newborn rat cortex and the BV-2 microglial cell line, a well-established cell model for the study of microglial properties. S100B expression was assessed by immunofluorescence in primary microglia and by RT-PCR, Western blotting, and immunofluorescence in BV-2 cells. S100B was found in microglia in the form of a filamentous network as well as diffusely in the cytoplasm and associated with intracellular membranes. S100B relocated around phagosomes during BV-2 phagocytosis of opsonized Cryptococcus neoformans. Furthermore, interferon-gamma (IFN-gamma) treatment caused cell shape changes and redistribution of S100B, and downregulation of S100B mRNA expression in BV-2 cells. Treatment of BV-2 cells with nanomolar to micromolar amounts of S100B resulted in increased IFN-gamma-induced expression of inducible nitric oxide synthase mRNA as well as nitric oxide secretion. Taken together, these data suggest a possible role for S100B in the accomplishment/regulation of microglial cell functions.     

Experimental Analysis of Speaking and Stuttering Rate in a Child Who Stutters

This study investigated the relationship between stuttering and speaking rates in a 9-year-old female child who stuttered. A single-subject experimental design was used to investigate the effect on stuttering of increasing and decreasing speaking rate. The experiment was followed by a treatment program that incorporated a control over speaking rate (based on the experimental data) and procedures designed to promote the transfer of treatment benefits. The speaking rate control program emphasized relatively slow (but not prolonged) speech which was gradually speeded up and included contingencies that were demonstrated to be effective and efficient in contributing to treatment effects. Data are also provided that demonstrate that the treatment effects generalized to beyond-clinic speaking conditions.