The tau protein levels in cerebrospinal fluid (CSF-tau) were examined in 27 patients with alcohol dependence (20 demented and 7 nondemented), 36 age and dementia severity-matched patients with Alzheimer's disease (AD), and 23 age-matched normal control subjects. The CSF-tau levels in the demented alcoholic group (alcohol-induced organic brain disorders, 25.4 +/- 10.2 pg/ml) was significantly lower (p < 0.0001) than that in the AD group (96.1 +/- 53.3 pg/ml), but not significantly different from that in the nondemented alcoholics (18.1 +/- 10.2 pg/ml) or the controls (19.2 +/- 12.9 pg/ml). Using a 44.9 pg/ml as a cut-off value (mean + 2 SD of the normal control group), only one patient with alcohol-induced organic brain disorders exceeded the value, whereas 3 of 36 of the AD group showed CSF-tau levels less than this level. These findings suggest that alcohol-induced organic brain disorders are a group of dementias that are characterized by normal CSF-tau levels, and that the CSF examination for tau in combination with other clinical findings may help in differentiating alcohol-induced organic brain disorders from AD.
We have previously shown that the hairpin ribozyme-like structure of the negative strand of the satellite RNA of arabis mosaic virus [(- )sArMV] has indeed ribozyme activity. However, some mutagenesis analyses revealed surprisingly that the wild type ribozyme was less active than almost all the other mutant ribozymes tested. These results were derived from a trans-acting system. Here we tested this ribozyme activity in a cis-acting system. We show that the (-)s ArMV hairpin ribozyme has different target-site specificities between cis and trans cleavages. The wild type ribozyme has the highest self-cleaving activity among the ribozyme variants tested.
The negative strand of the satellite RNA of tobacco ringspot virus [( — )sTRSV] is a self-cleaving RNA, of which self-cleaving domain is called the hairpin ribozyme. The negative strand of the satellite RNA of arabis mosaic virus [( — )sArMV] has been suggested to have a hairpin ribozyme-like secondary structure, and we have previously shown that this hairpin domain of (— )sArMV has ribozyme activity. Here we report characterization of the cleavage reaction of the ( — )sArMV hairpin ribozyme. Mutagenesis analyses in a transacting system revealed, surprisingly, that the wild-type ribozyme was less active than almost all the other mutant ribozymes tested. In a cis-acting system (self-cleaving reaction), however, the reaction of the RNA containing the wild-type sequence proceeds highly efficiently. This result suggests that the inefficient cleavage of the wild-type substrate in trans-acting system may be due to low efficiency at the substrate-binding step but not at the chemical cleavage step in the reaction. We also constructed a chimeric ribozyme between the catalytic hairpin domain from ( — )sArMV and the substrate-binding site from ( — )sTRSV. This chimeric ribozyme had the highest activity among the trans-acting hairpin ribozymes tested.
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