Hiroyasu Okuno

Genotypes of hepatitis C virus in Guangxi province, southern China.

Abstract Hepatitis C virus (HCV) has been subdivided into at least four genotypes, and the prevalence of each genotype has been reported to differ widely in different countries. Of 304 patients with chronic liver diseases (68 with chronic hepatitis, 50 with liver cirrhosis and 186 with hepatocellular carcinoma) from Guangxi Province in southern China, only 9 (3.0%) had antibodies to HCV as determined by a second‐generation enzyme immunoassay with a cut‐off index of 2.0 or more. The HCV genotypes of these nine cases were examined using polymerase chain reaction with type‐specific primers deduced from putative core gene. Seven of the nine cases had type II infection and the other two cases showed double infection with types II and IV. These findings indicate that the predominant HCV genotype in the Guangxi area is type II, as is the case in Japan, although the prevalence of HCV infection in patients with chronic liver diseases is much lower.

Comparison of effects of xenobiotics on extrahepatic and hepatic microsomal drug-metabolizing enzymes in mice

The content of microsomal protein is the same in both kidneys and small intestine, corresponding to 57% of the control value expressed as 100% in the untreated liver. The contents of P450 and cytochrome b(5), and the activity of NADPH-cytochrome c reductase in the kidney were higher than those in the small intestine, which were 17%, 22% and 41% of controls, respectively, in the former and 5%, 11% and 22% of controls in the latter. As compared with similar measurements made in the liver, the activities of substrate-metabolizing enzymes in these extrahepatic organs were very low. The activities of renal aniline hydroxylase, aminopyrine N-demethylase, 7-ethoxycoumarin O-deethylase, 7-methoxycoumarin O-demethylase and benzo(a)pyrene hydroxylase were 6%, 5%, 3%, 0.6% and 0.2% of controls, respectively. The activities of these enzymes in the small intestine were lower than those in the kidney or below the limits of detection. These results suggested that isoforms or their contents of P450 responsible for these substrate biotransformations are different among liver, kidneys and small intestine. Meantime, this study showed similar significant inductions by phenobarbital and rifampin of small intestinal and hepatic microsomal drug-metabolizing enzymes. In contrast, neither phenobarbital nor rifampin was capable of increasing renal microsomal enzymes, with the exception of benzo(a)pyrene hydroxylase which was induced by rifampin. These findings indicated that both liver and small intestine, but not kidneys contain the same phenobarbital- and rifampin-inducible P450 isoforms, cytochrome b(5) and NADPH-cytochrome c reductase. In addition, CCl(4) could be bioactivated by CYP2E1 to free radicals in the kidney which caused destruction of microsomal enzymes. In mice pretreated with phenobarbital, CCl(4) also attenuated the increase in content of P450 in the small intestine, which appeared to be a result of induction by phenobarbital of CYP2E1.

Retroperitoneal haematoma due to ruptured microaneurysm of the pancreaticoduodenal artery

A case of retroperitoneal haematoma due to a ruptured microaneurysm of the posterior superior pancreaticoduodenal artery in a 61 year old man is described. Ultrasonography and computed tomography revealed cystic masses near the gall‐bladder. Selective coeliac angiography disclosed a microaneurysm of the posterior superior pancreaticoduodenal artery. Surgical extirpation of the cystic masses was performed, and the histological finding was an encapsulated old haematoma.