Polyglutamine(Q) tract binding protein-1 (PQBP-1) was isolated on the basis of its interaction with polyglutamine tracts and localizes predominantly to the nucleus where it suppresses transcriptional activation by a neuron-specific transcription factor, Brn-2. Its C-terminal domain is highly conserved and binds to a component of the spliceosome. PQBP-1 possesses unique repetitive sequences that may fold as polar zippers. Interestingly, PQBP-1 also forms nuclear inclusion bodies, which are similar to those nucleated by the protein products of polyglutamine disease genes. Furthermore, because PQBP-1 is highly conserved in simple animal metazoans and plants (Caenorhabditis elegans and Arabidopsis), it may perform a basic function in cells. By the same token, disruption of the basic function could be critical to the disease process. Collectively, PQBP-1 might be a candidate molecule involved in the pathology of polyglutamine diseases. In this review, we discuss the structure and function of the PQBP-1 protein, the relevance of its aggregation and possible roles in normal and disease processes.

Animals↗

PubMedDate not supplied

Enhanced detection of brain tumors by [18F]fluorodeoxyglucose PET with glucose loading.

OBJECTIVE: We applied glucose loading during PET studies with [18F]2-fluoro-2-deoxy-D-glucose (FDG) to enhance detection of brain tumors by diminution of FDG uptake in normal gray matter. MATERIALS AND METHODS: This study involved three patients with glioblastomas. Two PET scans were performed in all cases within 1 week in control and with glucose loading state. RESULTS: In all patients, tumor was depicted more clearly with glucose loading than in the control study. The FDG uptake ratio of tumor to normal cortical gray matter showed a mean increase of 27% with glucose loading. CONCLUSION: This technique might be useful for detection of recurrent or residual tumors.

Adult↗

PubMedDate not supplied

Image generation of serotonin synthesis rates using alpha-methyltryptophan and PET.

PURPOSE: We sought to create functional images of the serotonin (5-HT) synthesis rate obtained with alpha-[11C]methyl-L-tryptophan (alpha-MTrp) and PET and standardize them into the stereotaxic coordinate system. METHOD: Dynamic PET scans were performed in 11 healthy subjects after an injection of alpha-MTrp. Results obtained by the Patlak plot and nonlinear least-squares methods using arterial plasma as input function were compared. The pixel-by-pixel calculation of functional images of 5-HT synthesis was done by the Patlak plot approach, after results were compared by two methods. Input function obtained by combining venous plasma and sinus radioactivities was also evaluated as an alternative to arterial input function. RESULTS: There were no significant differences in 5-HT synthesis between the two calculation methods. The normalized venous input functions gave similar results as the arterial input function. The regional rates of 5-HT synthesis from functional images were not significantly different from those obtained by graphical plotting. CONCLUSION: alpha-MTrp images could be converted into functional images representing 5-HT synthesis rates in the living brain, facilitating statistical comparison.

Adult↗