Isotopic compositions of Sr, Nd and Pb and REE concentrations have been determined for samples from“isotopically anomalous”Akagi volcano locating on the volcanic front of Northeast Japan Arc. The Sr isotopic compositions show a large variation with highly enriched isotope character (87Sr/86Sr=0.7060 to 0.7088) compared to those from other volcanoes on the front. The Nd isotopic compositions, ranging from εNd=-0.40 to -8.6, have a negative correlation with the Sr isotopic compositions. The Pb isotopic data along with Sr and Nd isotope systematics clearly indicate that the isotopic variations of Akagi volcano were caused by a two-component mixing between an end member isotopically similar to the primary magma on the volcanic front of Northeast Japan Arc and a lower crustal component. Chondrite-normalized REE patterns of Akagi samples show U-shaped, HREE-depleted pattern with positive Eu anomaly. Such REE features may have been developed by fractionation of amphibole formed by the reaction between a fluid-rich magma and clinopyroxene in granulitic lower crust. The fluid-rich magma could be originated from a highly metasomatized mantle wedge caused by the dehydration of oceanic slabs of the Pacific plate and the overlapping Philippine Sea Plate. Such a unique tectonic setting could result in higher water supply to the source region of magma than normal circumstances and thereby generating fluid-rich magma which could enhance assimilation of lower crust beneath Akagi volcano.
Interaction between trypsin and its substrate, NDV-F, is investigated by two approaches, in which the natural sequence and the polar/non-polar sequence are used respectively. In the first approach that we call“stepwise recognition”, addition of the connector-Es of trypsin resulted in stronger interaction between trypsin and NDV-F than that reported previously.2) The polar sequence of trypsin could predict only a functional site near 84-D. In the second approach, however, when the cleavage site of NDV-F is added to the polar sequence of trypsin, the other active sites of trypsin, 40-H and 177-S, can be predicted. We call it“sudden recognition by chance encounters”. The results suggest that the function of trypsin is recognized only when the enzyme encounters its substrate by chance.
Post-transfusion graft-versus-host disease (PT-GVHD) is a fatal adverse effect of blood transfusion.1)-3) The mortality rate is said to be 99% or higher.4) In spite of the seriousness of the disease, no definitively effective drug for curing patients of it has been identified. Recently, however, we reported on the potential usefulness of a protease inhibitor, nafamostat mesilate (NM), for treatment of PT-GVHD.5), 6) This potential usefulness of NM was suggested by the results in vitro experiments in which possible PT-GVHD effector cytotoxic T cell (CTL) clones and tumor necrosis factor β (TNF β) producing T cell clones established by us were used.7), 10) NM inhibited the cytotoxicity of the CTL clones and TNF β production by the TNF β producing clones.6) Based on these results, NM was administered to two patients with PT-GVHD. NM administration resulted in marked recovery of the patient peripheral blood mononuclear cell (PBMC) detected by microsatellite DNA polymorphism analysis distinguishable between donor and patient PBMCs. This is the first report of the marked recovery of PT-GVHD patient PBMC from very low ones which were replaced almost all with donor PBMCs. Moreover, NM administration was associated with body temperature normalization, disappearance of a body rash, liver function improvement and an unusual long survival time after onset of PT- GVHD in both cases. NM is potentially useful drug for treatment of PT-GVHD.