Thrombin-induced platelet aggregation −effect of dabigatran using automated platelet aggregometry−

Dabigatran, a direct oral thrombin inhibitor, has two therapeutic effects: anticoagulation; and antiplatelet activity. In the clinical field, evaluation of the effect of dabigatran on thrombin-induced platelet aggregation is difficult because of fibrin clot formation and platelet aggregation. The aim of this study was to establish a new platelet aggregation method and to investigate the effects of dabigatran on thrombin-induced platelet aggregation. Platelet aggregation with thrombin was performed with automated light transmission aggregometry (CS2400; Sysmex, Kobe, Japan) in 40 healthy subjects. Thrombin-induced platelet aggregation was performed using thrombin and platelet-rich plasma (PRP), and thrombin-induced fibrin polymerization was inhibited by adding the peptide Gly-Pro-Arg-Pro (GPRP). The effect of dabigatran was then evaluated using the above method. Thrombin at < 0.2 U/mL did not induce platelet aggregation in most normal subjects. Median maximum aggregation percent (MA%) (25th–75th percentile) with 0.5 and 1.0 U/mL of thrombin was 87.0% (79.3–90.8%), and 90.2% (86.5–92.2%), respectively. The anti-platelet effects of dabigatran were then evaluated with these concentrations of thrombin. Dabigatran (final concentration, 2.5–1000 nM) inhibited platelet aggregation by 0.2–1.0 U/mL of thrombin in a concentration-dependent manner in vitro. Dabigatran showed potent inhibitory effects against platelet aggregation induced by 0.5 and 1.0 U/mL thrombin with half maximal inhibitory concentrations of 10.5 and 40.4 nM, respectively. A standard for thrombin-induced platelet aggregation was developed using the CS2400 in healthy subjects, and dabigatran was confirmed to inhibit thrombin-induced platelet aggregation in vitro with PRP

屋久島の木質バイオマスのガス化装置開発に関する研究

Woody biomass gasification was carried out in a flash pyrolysis reactor. The gasifier was operated over a temperature range of 700-950°C. Two types of sample were studied. Firstly, only Japanese cedar was used. Secondly, a mixture of Japanese cedar and porous inorganic material were used. The main products from the woody biomass were gas, char and tar. The product gas obtained mainly consists of H_2, CO, CO_2 and CH_4. Whereas the product gas yields increased with increasing reactor temperature, char and tar yields were decreased with increasing temperature. When mixing porous inorganic material into woody biomass, tar yield was lower than that for the experiment corresponding without porous inorganic material. On the other hand, the product gas yield in case of porous material addition was higher than that for the experiment corresponding without porous inorganic material. The product gas yield increased with increasing the pore diameter of porous inorganic materials