Ever since the first intermediate host of Clonorchis sinensis was identified with Bulimus striatulus, it has been place to an important position in epidemics. One way to prevent Clonorchis sinensis is to exterminate Bulimus, which is itself the first intermediate host and there by to separate the life cycle of Clonorchis. In killing B. striatulus, nicotine sulfate and lindane have been chosen from insecticides which are widely used in farming areas. And then nicotine sulfate and lindane have been used to check their effectiveness in killing B. striatulus. In this experiment, the resistance of cercaria which parasites to B. striatulus has also been studied. Dipping method was used in the study. Nicotine sulfate and lindane have been used to check the mortality effect. Nicotine sulfate was used to check percentage of mortality in varied times. The existance of cercaria was tried only in nicotine sulfate. In the experiment of mortality effect of insecticides to B. striatulus and cercaria, the difference in killing rate and the resistance in different concentration and different length of time have been researched. It resulted as following: In the experiment with nicotine sulfate, the mortality increased with thicker concentration in the constant length of time. When compared the necessary liquid of nicotine sulfate and lindane in LD 50, nicotine sulfate was less used than lindane, but the mortality proved high. In the treatment to the same concentration of nicotine sulfate in different length of time, it proved that the longer period showed higher mortality. The mortality time required in LD 90 of nicotine sulfate was dependent on the concentration. And thicker concentration showed quicker effect. In the resistance of cercaria and B. striatulus to nicotine sulfate, the resistance of cercaria was proved to be stronger than that of B. striatulus.
parasitology-chemotherapy-helminth-trematode-Clonorchis sinensis ; Bulimus striatulus ; nicotine sulfate ; lindane

Tetrahydrobiopterin (BH4) is an essential cofactor in NO synthesis by endothelial nitric oxide synthase (eNOS) enzymes. It has been previously suggested that reduced intrahepatic BH4 results in a decrease in intrahepatic NO and contributes to increased hepatic vascular resistance and portal pressure in animal models of cirrhosis. The main aim of the present study was to evaluate the relationship between BH4 and portal hypertension (PHT). One hundred ninety-three consecutive patients with chronic liver disease were included in the study. Liver biopsy, measurement of BH4 and hepatic venous pressure gradient (HVPG) were performed. Hepatic fibrosis was classified using the Laennec fibrosis scoring system. BH4 levels were determined in homogenized liver tissues of patients using a high performance liquid chromatography (HPLC) system. Statistical analysis was performed to evaluate the relationship between BH4 and HVPG, grade of hepatic fibrosis, clinical stage of cirrhosis, Child-Pugh class. A positive relationship between HVPG and hepatic fibrosis grade, clinical stage of cirrhosis and Child-Pugh class was observed. However, the BH4 level showed no significant correlation with HVPG or clinical features of cirrhosis. BH4 concentration in liver tissue has little relation to the severity of portal hypertension in patients with chronic liver disease.
Adult ; Aged ; Biopterin/*analogs & derivatives/analysis ; *Chromatography, High Pressure Liquid ; Chronic Disease ; Elasticity Imaging Techniques ; Female ; Hepatic Veins/physiology ; Humans ; Hypertension, Portal/complications/*diagnosis/metabolism ; Liver/pathology ; Liver Cirrhosis/ultrasonography ; Liver Diseases/complications/*diagnosis/metabolism ; Male ; Middle Aged ; Nitric Oxide/metabolism ; Portal Pressure ; Regression Analysis ; Severity of Illness Index