This study identifies by microautoradiography activated microglia/macrophages as the main cell type expressing the peripheral benzodiazepine binding site (PBBS) at sites of active CNS pathology. Quantitative measurements of PBBS expression in vivo obtained by PET and [(11)C](R)-PK11195 are shown to correspond to animal experimental and human post-mortem data on the distribution pattern of activ...

Efforts were made to more clearly delineate target organs and mechanisms of toxicity for PBBs in cattle. Methods were developed to obtain sequential liver biopsies on bovine heifers which yield 0.5 to 1.0 g of tissue. PBB was fed at a dose of 250 mg/head/day to Holstein heifers for 202 days. This dose produced no clinical signs of toxicity in any of the heifers, yet this produced tissue PBB con...

Accumulation of intracellular tau fibrils has been the focus of research on the mechanisms of neurodegeneration in Alzheimer's disease (AD) and related tauopathies. Here, we have developed a class of tau ligands, phenyl/pyridinyl-butadienyl-benzothiazoles/benzothiazoliums (PBBs), for visualizing diverse tau inclusions in brains of living patients with AD or non-AD tauopathies and animal models ...

The metabolism of polybrominated biphenyls (PBBs) was studied in vitro by using rat liver microsomes in the presence of NADPH and atmospheric O2. Quantitative recoveries of all PBBs were obtained after incubations with control or 3-methylcholanthrene (MC) induced microsomes. Of the twelve major components, losses of only peaks 1 (2,4,5,2',5'-pentabromobiphenyl) and 3 (a hexabromobiphenyl) were ...

PURPOSE Technology-related behaviors (e.g., computer use) before bedtime (BT) have been associated with poorer and shorter sleep in adolescents; however, less is known about other behaviors in relation to sleep. This study characterized a range of behaviors in the hour before bed (i.e., pre-BT behaviors [PBBs]) and examined their relationship with sleep parameters during school and vacation per...

Introduction A recent book by Hutzinger et al. (1) reviews the chemistry of chlorinated biphenyls through the end of 1973. This wide-ranging review also includes discussions of metabolism and determination of chlorinated biphenyls. The present report reviews areas of chlorobiphenyl and bromobiphenyl chemistry held to be pertinent to the Subcommittee's concern for possible health effects of thes...