EFFECTS OF IXERIS CHINENSIS (THUNB.) NAKAI BOILING WATER EXTRACT ON HEPATITIS B VIRAL ACTIVITY AND HEPATOCELLULAR CARCINOMA

Background: Hepatitis B virus (HBV) infection and hepatocellular carcinoma are major diseases that affect the Taiwanese population. Therefore, the development of an alternative herbal medicine that can effectively treat these diseases is a research target. In this study, we tested Ixeris Chinensis (Thunb.) Nakai boiling water extract (ICTN BWE) in vitro and analysed its effects on the HBV and liver cancer. Materials and Methods: We used a human liver cancer cell line (Hep3B, a cell line that continuously secretes HBV particles into a medium) as an experimental model for the screening of various ICTN BWE concentrations and their effects on the HBV in vitro. Results: Our results showed that 75 µg/mL ICTN BWE downregulated the relative expression of the hepatitis B virus surface antigens (HBsAg) to 77.1%. Using the human liver cancer cell lines HuH-7 and HepG2, and 3-(4,5- dimethylthiazol-zyl)-2,5-diphenyl tetrazolium bromide (MTT) and tumour clonogenic assays, we then showed that ICTN BWE inhibits hepatocellular carcinoma growth. Conclusion: Fluorescent microscopy of DAPI(4',6-Diamidino-2-phenylindole)-stained nuclei and DNA fragmentation assays confirmed the inhibitory effects of ICTN BWE on liver tumour cell growth through induction of apoptosis

Yc-1, a Novel Activator of Platelet Guanylate Cyclase

　　YC-1 [3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole] inhibited the aggregation of and ATP release from washed rabbit platelets induced by arachidonic acid (AA), collagen, U46619, platelet-activating factor (PAF), and thrombin in a concentration-dependent manner. YC-1 also disaggregated the clumped ptatelets caused by these inducers. The thromboxane B2 formation caused by collagen, PAF, and thrombin was inhibited by concentrations of YC-1 that did not affect formation of thromboxane B2 and prostaglandin D2 caused by AA. YG-1 suppressed the increase of intracellular Ca2+ concentration and generation of inositol 1,4,5- trisphosphate caused by these five aggregation inducers. Both the cAMP and cGMP contents of platelets were increased by YC-1 in a concentration- and time-dependent manner. Like sodium nitroprusside, YC-1 potentiated formation of cAMP caused by prostaglandin E, but not that by 3-isobutyl-1- methylxan- thine. Adenylate cyclase and cAMP phosphodiesterase activities were not altered by YC-1. Activities of granylate cyclase in platelet homogenate and cytosolic fraction were activated by YC-1, whereas particulate guanylate cyclase activity was unaffected. The antiplatelet effect of sodium nitroprusside but not that of YC-1 was blocked by hemoglobin and potentiated by superoxide dismutase. After intraperitoneal administration for 30 minutes, YC-1 prolonged the tail bleeding time of conscious mice. These data indicate that YC_1 is a direct soluble guanylate cyclase activator in rabbit platelets. It may also possess antithrombotic potential in vivo.#0996

Inhibition of Collagen-Induced Platelet Aggregation and Adhesion by a Pseudocyanide Derivative of Avicine Isolated from Zanthoxylum Integrifoliolum Merr

Avicine pseudocyanide, a derivative of avicine isolated from Zanthoxylum integrifoliolum Merr., inhibited collagen- induced platelet aggregation and release reaction in a concentration-dependent manner. Trimucytin is a collagen- like snake venom protein isolated from Trimeresurus mucrosquamatus. Avicine pseudocyanide also inhibited trimucytin (1μg/mL)- induced platelet aggregation and release reaction concentration dependently. The IC values of avicine pseudocyanide on collagen (10μg/ mL)- and trimucytin (1 μg/mL)-induced platelet aggregation were 47.3± 4. 1 and 62.5 ± 5.6 μM, respectively. Avicine pseudocyanide at a concentration of 300 microM inhibited less than 30% of platelet aggregation induced by ADP (20 μM ), AA (100 μM), U46619 (1 μM), PAF (2 ng/mL) and thrombin (0.1 U/mL). The concentration-response curve of collagen- induced platelet aggregation was shifted to the right by avicine pseudocyanide (20-100 μM) concentration dependently . The Schild plot showed that pAand pA values of avicine pseudocyanide were 4.8 and 4.3, respectively, with slope of -1.9. Avicine pseudocyanide also inhibited collagen (10 μg /mL)-induced aggregation of rabbit whole blood with an IC of 145 ± 13 μM. Collagen-induced thromboxane Bformation was also inhibited by avicine pseudocyanide in a concentration-dependent manner with a maximal effect at 100 microM. However, arachidonic acid(AA)-induced thromboxane Band prostaglandin Dformations were only partially suppressed by a high concentration of avicine pseudocyanide (300μM). Avicine pseudocyanide (100 μM) inhibited the [H]inositol monophosphate formation and the rise of intracellular Ca concentration caused by collagen but not those caused by AA, U46619, platelet-activating factor and thrombin. In the presence of prostaglandin E,Mg- dependent platelet adhesion to collagen was inhibited by avicine pseudocyanide with an IC of 278 ± 16 μM. These data indicate that avicine pseudocyanide is an inhibitor of collagen-induced platelet aggregation and platelet- collagen adhesion.#A119330

An efficient incremental learning mechanism for tracking concept drift in spam filtering.

This research manages in-depth analysis on the knowledge about spams and expects to propose an efficient spam filtering method with the ability of adapting to the dynamic environment. We focus on the analysis of email's header and apply decision tree data mining technique to look for the association rules about spams. Then, we propose an efficient systematic filtering method based on these association rules. Our systematic method has the following major advantages: (1) Checking only the header sections of emails, which is different from those spam filtering methods at present that have to analyze fully the email's content. Meanwhile, the email filtering accuracy is expected to be enhanced. (2) Regarding the solution to the problem of concept drift, we propose a window-based technique to estimate for the condition of concept drift for each unknown email, which will help our filtering method in recognizing the occurrence of spam. (3) We propose an incremental learning mechanism for our filtering method to strengthen the ability of adapting to the dynamic environment