FM sonography in diffuse liver disease: prospective assessment and blinded analysis

FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease.     

Evaluation of the effects of opioid agonists and antagonists under a delayed matching-to-sample procedure in pigeons

The effects of several opioid agonists and antagonists were examined in pigeons performing under a delayed matching-to-sample procedure. The mu agonists morphine and l-methadone, the kappa agonists U 50,488 and ethylketocyclazocine, and the opioid antagonist naloxone had no effect on the accuracy of responding. These drugs were, however, behaviorally active as evidenced by the dose-dependent decreases in rates of responding associated with their administration. In contrast, the sigma agonists (+) N-allylnormetazocine and phencyclidine decreased the accuracy of responding in a dose-dependent fashion. The relative magnitude of these drug-induced decreases in accuracy were similar across the no delay (0-s), short (2-s), and long (8-s) delay intervals. For these drugs, accuracy-decreasing effects were obtained only at doses that reduced rates of responding. The results of the present investigation parallel those reported in pigeons responding under drug discrimination tasks, in which the discriminative stimulus properties produced by the mu and kappa agonists are similar to each other but distinguishable from those produced by the sigma agonists.Recipient of Research Scientist Development Award DA 00033 from the National Institute on Drug Abuse