A Tohgo

Learn More
The mechanisms by which B16, 3LL and MH134 tumor cells induce platelet aggregation were studied. The B16 and 3LL tumors, which have high or moderate procoagulant activities, aggregated platelets only in the presence of Ca2+ and plasma factors. MH134, which had much lower procoagulant activity, aggregated platelets even in the absence of these factors. The(More)
Intravenous inoculations of B16 cells having high procoagulant, thrombingenerating, and platelet-aggregating (PA) activities resulted in severe platelet reduction and fibrin-rich thromboembolism in the lungs, whereas those of 3LL cells, whose activities were moderate, caused only moderate changes. MH134 cells with low procoagulant, no thrombin-generating(More)
PURPOSE To investigate the excretion of irinotecan hydrochloride (CPT-11) and its active metabolite, SN-38, into the gastrointestinal lumen via the biliary and/or intestinal membrane route after dosing with lactone and carboxylate forms of CPT-11, and to evaluate the toxic and antitumor effects of the two forms. METHODS The excretions of CPT-11 and SN-38(More)
DX-8951f, a new water-soluble camptothecin (CPT) derivative, has been reported to show potent antitumor effects against various tumors in vitro and in vivo. We further evaluated the cytotoxic effect of DX-8951f against eight drug-resistant sublines derived by stepwise exposure of human oat cell carcinoma PC-6 to various drugs. In paclitaxel-, adriamycin-,(More)
DX-8951f is a water-soluble camptothecin analogue with a unique hexacyclic structure. Compared to other current camptothecin derivatives, DX-8951f is the most effective topoisomerase I (topo I) inhibitor and has the most potent cytotoxic activity against various tumour cell lines in vitro. Of particular interest is DX-8951f's significant effect on certain(More)
The synthetic low-toxicity lipid A analog DT-5461a induces endogenous TNF production in mice. The activity of TNF so induced is probably the main contributor to the antitumor effect of this compound. In the present study, we investigated the mechanism by which DT-5461a induces TNF production in murine macrophage RAW 264 cells. DT-5461a mimicked the ability(More)
Protamine sulfate and combinations of heparin-cortisone acetate known as having anti-angiogenic activities impaired the growth of chorioallantois at the dose inducing no decrease in growth rate of the embryos. This inhibitory effect of the agents is presumed to be mediated by the specific inhibition of the growth of endothelial cells forming chorioallantoic(More)
Thrombin generated in the process of platelet aggregation induced by three metastasizing murine tumors was measured using a chromogenic substrate specific for thrombin. Addition of B16 cells or 3LL cells to the platelet-rich plasma induced the generation of a significant amount of thrombin during the lag period preceding aggregation, while that of MH134(More)
We previously reported that DX-8951f, a novel water-soluble camptothecin analog, significantly inhibits the growth of various human and murine tumors in vitro and in vivo. The antitumor effects and topoisomerase I inhibitory activity of DX-8951f are stronger than those of other current camptothecin analogs. In this study, we established an SN-38-resistant(More)
DX-8951 is a novel water-soluble derivative of camptothecin. We evaluated the effects of DX-8951 on the growth of several pancreatic tumor cell lines in vitro and in vivo. In vitro cytotoxic activity of DX-8951 against SUIT-2 and KP-1N cells, as indicated by IC50 value, was several times more potent than that of SN-38, an active metabolite of CPT-11, and(More)