Mitsuru Yasunaga

Ultrastructural Study of Development of Hepatic Necrosis Induced by TNF-α and D-Galactosamine

Recent studies have suggested an associationbetween tumor necrosis factor-α (TNF-α) andthe development and progression of acute liver failure.To investigate the role of TNF-α in the mechanism of massive hepatic necrosis, we studied a mousemodel of TNF-α and D-galactosamine (GalN)-inducedhepatic necrosis by ultrastructural analysis.Administration of GalN caused edema of hepatocellular microvilli and widening of sinusoidalendothelial fenestrae (SEF); administration ofTNF-α caused only a widening of the SEF. Massivehepatic necrosis with hemorrhage was seen 6 hr afterconcomitant administration of TNF-α and GalN. In theultrastructural analysis, edema of the hepatocellularmicrovilli, widening of the SEF, and transmigration ofred blood cells (RBC) and platelets to the space of Disse without exfoliation and necrosis ofthe sinusoidal endothelial cells were observed. Fibrindeposits were seen in areas adjacent to injuredhepatocytes. The diameter of the SEF was significantly greater than in the nontreated group and thegroups treated with TNF-α or GalN alone. Theseresults suggest that as a consequence of the increase indiameter of the SEF, transmigration of RBCs andplatelets to the space of Disse may have resulted inmassive hepatic necrosis due to occlusion of themicrocirculation.

A new therapeutic trial of secretin in the treatment of intrahepatic cholestasis

SummaryMany animal experiments have been studied on the choleretic effects of secretin. We intended to estimate secretin choleresis in human (15 patients) who had received PTCD or T-tube insertion into the common bile duct. Based upon these data of secretin and choleresis, secretin was administered to 11 patients with prolonged jaundice due to intrahepatic cholestasis in order to evaluate this as a new therapy for intrahepatic jaundice. As controls, eleven patients with intrahepatic cholestasis treated with steroid hormones and/or phenobarbital were used. In all cases with biliary drainage, secretin produced a remarkable choleretic effect with a high concentration of bicarbonate. In 9 out of 11 patients with intrahepatic cholestasis who were treated with secretin, levels of serum bilirubin decreased linearly and other liver function tests returned to the normal range. The mean values of T1/2 (number of days required for reduction by half) of serum bilirubin in 9 effective cases to secretin was 10.8 days. On the other hand, that in 11 effective cases treated with steroid hormones and/or phenobarbital was 23.2 days. These results suggest that secretin therapy may be an effective treatment for intrahepatic cholestasis.

Clinical evaluation of glucagon and insulin in therapy of fulminant hepatitis

SummaryForty five patients were examined in order to evaluate the usefulness of glucagon and insulin as a therapy of fulminant hepatitis. Thirty patients were treated with simultaneous infusion of glucagon and insulin, whereas prednisolone was given at a daily dose of 60 to 90 mg in 15 cases. In the former group, 1 mg of glucagon and 10 units of regular insulin were infused over a period of 2 to 6 hours. Two such treatments were given per day in the early critical period of fulminant hepatitis. The therapeutic effect of glucagon and insulin was evaluated in comparison with that of prednisolone, and additionally, with a combination therapy of either blood exchange or plasmapheresis in both groups. The survival rate was superior in the group treated with glucagon and insulin (46%) and in the one with combined infusion of these hormones plus plasmapheresis (33%).

Percutaneous hot water injection therapy (PHoT) for treatment of hepatocellular carcinoma: a comparision with percutaneous ethanol injection therapy (PEIT)

We investigated the safety and efficacy of percutaneous hot water injection therapy (PHoT) in six patients with hepatocellular carcinoma (HCC). PHoT produced the marked effect in five (62.5%) of eight lesions. No serious adverse effects have been encountered. We also compared the usefulness of percutaneous ethanol injection therapy (PEIT) (22 patients, 32 lesions) and PHoT (five patients, seven lesions) in patients with HCC with diameter of 3 cm or less. Patients in the PHoT group received significantly fewer treatments than in the PEIT group (P < 0.01), because the volume injected per treatment was greater. Residual cancer was found in five (15.6%) of 32 lesions after PEIT and in three (42.9%) of seven lesions after PHoT, but the difference was not statistically significant. Pain tended to be less frequent in patients treated with PHoT than in patients treated with PEIT. We could not determine whether PHoT was superior to PEIT, but our findings indicate that PHoT may be a safe and effective for treating HCC.

Secretin prevents taurocholate-induced intrahepatic cholestasis in the rat

Secretin is known to stimulate the flow of bicarbonate-rich bile from the bile-duct epithelium, but has no effect on hepatocytes. To investigate the effects of secretin on bile production during intrahepatic cholestasis, we infused secretin into rats with taurocholate-induced cholestasis. Secretin was given at 0.25 and 0.50 units.min-1.kg-1 to Wistar rats that simultaneously received a continuous infusion of taurocholic acid at above its maximum hepatic transport capacity to produce cholestasis. When taurocholic acid was infused at doses of 1.4 and 1.6 mumol.min-1.100 g b.w.-1, bile volume decreased in control rats. In contrast, the simultaneous infusion of secretin significantly increased bile flow and the biliary excretion of bile acids and bicarbonate. The serum taurocholic acid level at the end of the experiment was significantly lower in the secretin-treated groups than in the control group. These findings indicate that secretin prevents taurocholate-induced cholestasis and may enhance the biliary excretion of bile acids.

High MDM2 mRNA expression in hepatoblastoma cell-lines

Abstract Both p53 and MDM2 genes are parts of a physiological pathway frequently impaired in human cancer. This is the report on the analysis of p53 and MDM2 genes in a group of four hepatocellular carcinoma cell-lines and one hepatoblastoma cell-line. Four cell-lines were screened for the presence of p53 mutations using the polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) method. Investigation of the MDM2 gene revealed neither gene amplification nor rearrangement in all cell-lines. However MDM2 mRNA in a hepatoblastoma cell line(HepG2) was elevated to about 2.4 times the level of normal human liver.

Evaluation of Laparoscopic Findings in Chronic Hepatitis C

Abstract: To elucidate the differences in the progression of liver cirrhosis of chronic hepatitis B and C, the laparoscopic appearance of the liver surface and the histological findings were carefully assessed in 65 patients with chronic hepatitis B and 58 patients with chronic hepatitis C.

Effects of secretin on bile production in two kinds of cholestatic models by choledocho-caval fistula and bile duct ligation in rats.

SummarySecretin is known to stimulate bile flow from the bile duct epithelium. To investigate the effects of secretin in cholestasis, we studied the response of the bile flow and the excretion of biliary components to secretin using two cholestatic models with or without damage to the bile duct epithelium. The model without bile duct epithelial damage was a choledocho-caval (CC) fistula over a 24-hour period, and the model with bile duct damage was a bile duct ligation over a 48-hour period. Secretin was administered by intravenous infusion for 30 minutes and bile was collected for 120 minutes. Controls were given saline similarly. The bile flow and biliary bicarbonate excretion rate were significantly increased after secretin infusion in the CC fistula rats when compared with the control rats, but no stimulation by secretin was observed in the ligated rats. These data indicate that secretin-induced bile production was enhanced under cholestatic conditions with no bile duct epithelial disturbance.

Protective effect of deferoxamine for acetaminophen induced liver injury

Acetaminophen is widely prescribed analgesic and antipyretic drug, which is known to cause hepatic necrosis in both humans and experimental animals at high doses. Accumulated data implicated a metabolism-dependent (cytochrome p-450) generation of partially reduced oxygen species which can initiate the peroxidation of membrane lipids related to loss of cell viability in this compound. Iron ions play a major role in lipid peroxidation, which is a effect of several agents including acetaminophen (APAP)[I]. Deferoxamine (DFO) can prevent lipid peroxidation leading to cell death by trapping iron ions. Therefore, it is of interest to determine whether DFO can protect against APAP induced liver injury. Male Sprague-Dawley rats were treated with 25 mg/kg of 3-methylcholanthrene (Sigma) as a i0 ml solution in corn oil by intraperitoneal injection 16 h prior to use and then fasted overnight. This treatment makes rats more susceptible to acetaminophen by the induction of cytochrome p-450. In the experiments, rats were divided into three groups as follows : (A) rats treated with 750 mg/kg of APAP alone ; (B) rats pretreated with 200 mg/kg of DFO 60 min before APAP injection ; (C) rats treated with 200 mg/kg of DFO 60 min before and 120 min after APAP injection. All rats were treated by intraperitoneal injection. Serum ALT was examined 8 h after APAP treatment and mortality was investigated 24 h later. Figure indicates that APAP produced an increased ALT level (11666 • within 8 h and mortality was 87.5 %. By contrast, pretreatment with DFO significantly reduced ALT to 3406• 894 concomitant with reduced mortality (37.5%). This protection by DFO was dose-dependent up to 400 mg/kg (data not shown). Additional DFO treatment showed more protective effect. Histology showed massive liver cell necrosis within 8 h with the treatment of APAP (data not shown). DFO attenuated the impairment of liver histology as well as the increase in ALT level (data not shown). These results indicate that DFO is a strong protective agent against APAP induced liver injury. Figure : Serum ALT level and mortality by either APAP alone (A) ALT or with pretreatment of DFO (B) or additional treatment of DFO (C) Reference : I. Sakaida I., et al : J. Biol. Chem. 1991 ; 266 : 717-722 i0000

Changes of depolymerized and polymerized tubulin proteins in the liver after taurocholic acid administration with or without colchicine pretreatment and cholestasis due to cytochalasin B and bile duct ligation in rats

Abstract Microtubules, which are components of the cytoskeleton, are the organelles involved in vesicular transport. In the hepatocyte, the microtubular network is presumed to be concerned with bile acid secretion, and there may also be some structural changes in cholestatic conditions. The polymerized tubulin levels were determined as microtubules in the liver by the radiochemical assay in rats after the administration of taurocholic acid, colchicine, taurocholic acid following the treatment of colchicine, cytochalasin B and common bile duct ligation. The polymerized tubulin levels were increased after the high dose administration of taurocholic acid, but were decreased after the treatment with colchicine. In cholestasis models induced by cytochalasin B and common bile duct ligation, the polymerized tubulin levels were markedly increased. These findings suggest the microtubule system plays an important role in the excretion of a large amount of bile acids into the bile, and that growth of the microtubular network occurs in cholestasis in order to promote the vesicular transport and to maintain the cell shape.