Mantle Bouguer gravity anomaly gives density anomaly in the upper mantle. We compiled the mantle Bouguer anomaly in the Japan Trench and Arc using data of crustal structure given from explosion seismology. A profile of the gravity anomalies across the subduction zone shows a regional positive anomaly over the island arc. The profile also shows local low-density anomalies beneath the central part of the island arc and near the trench axis. A relatively positive anomaly of about 70 mgals still exists over the island arc after removing the effect of the subducting slab. We suspect missing of the low-density layers on the surface of the slab can explain the result. The low-density zone beneath the central part of the island arc relates to the zone of volcanic activity expected from petrological studies. Another low density zone relates to accretion of sediment near the trench axis.
Negatively charged polymer colloid particles were found to gather near a like charged glass plate in deionized dispersions. The particle distribution near the glass plate was observed using a confocal laser scanning microscope. The number of particles about 5-10μm from the glass plate was about two times larger than that in the bulk dispersion and decreased gradually with distance. The tail of the peak in the particle distribution profile reached about 50μm from the glass plate, a very long distance compared with the range of ordinary electrostatic interaction. The 'positive adsorption' of the particles could be observed even in density matched H2O-D2O mixtures. It could not be observed at an NaCl concentration of 10-4M. These results show that the driving force for the positive adsorption is not sedimentation of the particles, but an electrostatic interaction. The positive adsorption increased with the number of charges on the particles and the glass surface. This indicates that the driving force of the positive adsorption is an electrostatic attraction between like charged particles and glass plate.
Effects of acidic and basic fibroblast growth factors (a- and bFGFs, respectively) on spatial learning performance of fimbria-fornix (FF)-lesioned rats were investigated in Y-maze and water maze tests. Transection of FF produced severe spatial memory deficits revealed by both tests. Intracerebroventricular (i.c.v.) injection of aFGF (100-400ng/rat) and bFGF (100-400ng/rat) 30min before the daily session significantly improved the spatial learning impairments induced by FF-lesion in both types of spatial learning tasks. In contrast, i.c.v. injection of nerve growth factor (NGF, 100-400 ng/rat) did not ameliorate the spatial learning performance in FF-lesioned rats. This is the first report providing direct evidence that both aFGF and bFGF improve the spatial learning impaired by loss of septo-hippocampal cholinergic afferents.
Recombinant vaccinia viruses that express a full-length Hepatitis C virus (HCV) genome were constructed. Chimpanzee liver cells were infected with the recombinant viruses and analyzed by electron and immunoelectron microscopy. Three kinds of structures specific to recombinant HCV vaccinia infection were found in the cytoplasm of the infected cells. They are virus-like particles, clustered particles and high density reticular structures, the latter two of which are often fused together, indicating that they are related each other. Monoclonal antibodies against core, envelope and NSl and human HCV antisera clearly stained the reticular structures, indicating that at least the reticular structures and perhaps the clustered particles are derived from HCV proteins.
Although formation of characteristic fluorescence (Exmax/Emmax:370/440nm) in renal tissues has been known to be enhanced in diabetic model rats and the natural fluorophores have been thought as advanced glycation end products (AGEs), these structures remain unclear to this date. Since we had already isolated Crossline derivatives as the main fluorescent AGE-products formed in a sugar-amine-model system in vitro, we tried to determine whether crossline-like structure can be found in renal tissues of rats with diabetic nephropathy. Specific polyclonal antiserum against crossline-structure and its affinity chromatography-purified antibody were prepared. The purified antibody did not recognize native rat serum albumin (RSA), but it recognized RSA modified by prolonged incubation with high concentration of glucose (AGE-RSA) as well as the crossline-hapten. The immunoreactivity of AGE-RSA was completely blocked by co-incubation with crossline-derivative. These results confirm immunochemically that in vitro-prepared AGE-proteins contain crossline-like structure. Similarly, crossline-like structure in AGE-proteins in vivo was examined immunohistochemically. In streptozotocin-induced diabetic rats, both crossline-like immunoreactivity and fluorescence (Ex/Em:370/440 nm) of renal tissues increased, and the levels rose further with progression of diabetic nephropathy. Crossline accumulation was observed in specific renal tissues such as glomeruli (basement membrane and mesangium), tubules, and Bowman's capsules. Although the contribution of crossline-like substance(s) to total fluoroescence in diabetic renal tissues has not as yet been quantitatively determined, our results provide evidence that crossline accumulation occurs in renal tissues of rats in association with the initiation and/or progression of diabetic nephropathy.