The antioxidant effect of green tea catechin ameliorates experimental liver injury.

PURPOSE: Several studies have reported green tea catechin to have both antifibrotic and anti-oxidative effects. The goal of this study was to evaluate the effect of green tea cathechin therapy in hepatic tissue injury using cholestatic rats with bile duct ligation. MATERIALS AND METHODS: We performed bile duct ligation on cholestatic seven-week-old male Wistar rats and classified them into three groups according to the method of treatment. The groups comprised the SHAM group, the NT-group (no-treatment-group), and the T-group (treatment-group). The rats were orally administered green tea catechin at a dose of 50mg/kg/day and were sacrificed on the 17th postoperative day. We subsequently investigated the levels of fibrosis and antioxidant activity associated with various clinical markers. We evaluated the serum AST and ALT levels and performed immunohistochemical analyses for 4-hydroxynonenal (4-HNE), 8-oxo-2'deoxyguanosine (8-OHdG) and transforming growth factor-beta1 (TGF-beta1). We also evaluated the levels of activator protein-1 m-RNA (AP-1 m-RNA) and tissue inhibitor metalloproteinase-1 m-RNA (TIMP-1 m-RNA) by Real Time PCR. Finally, we performed Azan staining and immunohistochemical staining of alpha-smooth muscle actin (alpha-SMA) to evaluate the degree of fibrosis. RESULTS: The values of serum AST, serum ALT, AP-1 m-RNA, alpha-SMA, TGF-beta1, 4-HNE, and 8-OHdG in the T-Group were significantly lower than those in NT-Group. Therefore, the administration of green tea catechin might have suppressed the oxidative stress, controlled the stellate cell activation and consequently reduced the fibrosis. CONCLUSION: Green tea catechin may reduce hepatic fibrosis by suppressing oxidative stress and controlling the transcription factor expression involved in stellate cell activation.

Recent advances in antiviral agents: antiviral drug discovery for hepatitis viruses.

Hepatitis B virus (HBV)- or hepatitis C virus (HCV)- associated liver diseases are now one of the important health problems in the world because of the high numbers of patients and the serious consequences. Recently, however, relatively effective treatments with antiviral agents have become available. Interferon (IFN), lamivudine and adefovir are now approved for treatment of HBV-associated liver diseases and they have been shown to be fairly effective. The goal of treatments for HBV-associated liver disease is to achieve a clinical cure in as short a period as possible without producing resistance mutation of the virus. Several nucleotide analogues with more potent antiviral activities are now in clinical trials. In the case of HCV-associated liver diseases, Pegylated IFN (Peg IFN) + ribavirin combination therapy is the standard and most effective treatment with a sustained response of 60-70%. The goal of the treatments for these liver diseases is to induce the complete eradication of the infected virus and at present new anti HCV drugs targeting the molecular segments of the virus are under development. It is expected that the complete eradication of infected virus will be possible in most cases in the near future.

Superconducting pi qubit with a ferromagnetic Josephson junction.

Solid-state qubits have the potential for the large-scale integration and for the flexibility of layout for quantum computing. However, their short decoherence time due to the coupling to the environment remains an important problem to be overcome. We propose a new superconducting qubit which incorporates a spin-electronic device: the qubit consists of a superconducting ring with a ferromagnetic pi junction which has a metallic contact and a normal Josephson junction with an insulating barrier. Thus, a quantum coherent two-level state is formed without an external magnetic field. This feature and the simple structure of the qubit make it possible to reduce its size leading to a long decoherence time.

Reversible maps in two-degrees of freedom Hamiltonian systems.

It has been shown that a sub-class of two-degrees of freedom Hamiltonian systems possesses a reversing symmetry discovered by Birkhoff in the restricted problem of three bodies. This mixed space-time reversing symmetry, which is different from the classical time reversal symmetry, can be shared by time-reversible as well as time-irreversible systems. Examples of time-irreversible systems which possess this reversing symmetry are the restricted problem of three bodies as shown by Birkhoff in 1915, and a special case of the motion of a rigid body with a fixed point discussed in this paper. If a Hamiltonian system possesses this Birkhoff reversing symmetry, then there exists a surface of section for which the corresponding Poincare map is Birkhoff-reversible. The Birkhoff-reversibility of this map may be used to study its global dynamics such as the locations and the distribution of the stable and unstable periodic points, the distribution of stable and chaotic regions, and the identification of the scattering regions. (c) 2002 American Institute of Physics.

[Present status of clinical trials on long-acting IFNs preparations (PEG-IFN alpha 2a, alpha 2b, IFN alpha-minipellet)].

Interferon(IFN) is an essential component of the treatment of chronic HCV infection and at present, it is the most important to improve its efficacy, not only for HCV chronic liver diseases, but also for the prevention of HCV-associated hepatocellular carcinoma. Two long-acting IFN preparations(PEG-IFN alpha 2a and 2b) have been used at present and clinical studies have shown that sustained virologic, biochemical and histological responder rates are significantly higher in PEG-IFN-treated patients with HCV associated chronic hepatitis and cirrhosis comparing with ones treated with conventional IFN. In addition, PEG-IFN treatment in combination with ribavirin seems to be the best for HCV-associated chronic liver diseases.

Successful treatment for bronchial bleeding from invasive pulmonary metastasis of hepatocellular carcinoma: a case report.

Pulmonary metastasis is frequently seen in patients with advanced hepatocellular carcinoma. However, information is limited concerning life-threatening complications and effective treatment of pulmonary metastasis because of the poor prognosis of patients with advanced hepatocellular carcinoma. Recent remarkable progress in detection and treatment of hepatocellular carcinoma has improved prognosis, making management of pulmonary metastasis an important clinical issue. We describe a 68-year-old man with pulmonary metastasis of hepatocellular carcinoma and sudden onset of hemoptysis from bronchial invasion. Transcatheter embolization was performed successfully via the bronchial artery with disappearance of bloody sputum. Peribronchial pulmonary metastasis of hepatocellular carcinoma can cause life-threatening hemoptysis. Transcatheter arterial embolization may be one of therapeutics for hemoptysis from invasive pulmonary metastasis of hepatocellular carcinoma.

Endotoxin increases paracellular permeability of isolated rat hepatocyte couplets.

Hyperbilirubinemia is frequently associated with endotoxemia. Regurgitation of bile constituents including bilirubin into the sinusoidal space is prevented by tight junctions which maintain paracellular permeability between hepatocytes. To investigate the mechanism of endotoxin-associated hyperbilirubinemia, we have studied the changes in paracellular permeability of primary hepatocyte couplets treated with endotoxin. In addition, we examined the effects of ursodeoxycholic acid (UDCA), which has been widely used for various liver diseases, on endotoxin-associated changes in paracellular permeability. The paracellular permeability of hepatocyte couplets was evaluated by paracellular penetration of fluorescein isothiocyanate (FITC)-dextran with molecular weights of 3, 10 and 70K using confocal laser scanning microscopy. Endotoxin increased the paracellular penetration of FITC-dextran 3 and 10K. These changes were prevented by treatment with UDCA. There was little paracellular penetration of FITC-dextran 70K under any conditions. These results suggested that endotoxin increased the paracellular permeability of hepatocyte couplets and these changes were prevented by treatment with UDCA. Furthermore, bile regurgitation through the paracellular route is involved in endotoxin-associated hyperbilirubinemia, and UDCA might be a potential therapeutic agent for endotoxin-associated hyperbilirubinemia.

Daily variation of azygos and portal blood flow and the effect of propranolol administration once an evening in cirrhotics.

BACKGROUND/AIMS: Esophageal variceal bleeding occur more often at night, however, the mechanism for this remains unclear. This study investigated the daily variation of azygos blood flow (AzBF) and portal blood flow (PBF) and the effects of propranolol administration given once in evening in cirrhotics. METHODS: Blood flow were measured using magnetic resonance imaging. Hemodynamic parameters were determined at 08:00, 16:00 24:00 and again 08:00 h, and were measured at baseline and after 14 days oral administration of propranolol (30 mg, n = 7) or placebo (n = 7) at 19:00 h in 14 patients. RESULTS: A daily fluctuation of AzBF and PBF was observed, peaking at 24:00 h in nine patients. In three other patients, peak AzBF and PBF were observed both at 16:00 and 24:00 h. Two patients were constant throughout the day. When the daily variation was compared, ANOVA showed a significant difference (P < 0.001). Propranolol administration at 19:00 h reduced AzBF (-40.7 +/- 17.9% vs. baseline, P < 0.001) and PBF (-26.5 +/- 10.7% vs. baseline, P < 0.01) at 24:00 h. CONCLUSIONS: We found that in most cirrhotics, AzBF and PBF peaks at midnight. Dosing of propranolol in the evening may be important for its role in preventing variceal bleeding.

Expression and role of vascular endothelial growth factor in liver regeneration after partial hepatectomy in rats.

Vascular endothelial growth factor (VEGF) plays a major role in angiogenesis, which is essential for both healing of injured tissue and proliferation of carcinoma cells. In this study we elucidated the expression and role of VEGF in rat liver regeneration after partial hepatectomy. VEGF expression was mainly detected in periportal hepatocytes and reached a maximal level 48-72 hr after partial hepatectomy by both immunohistochemistry and in situ hybridization. Similarly, immunohistochemistry for Ki-67 showed that the proliferative activity of sinusoidal endothelial cells was highest in the periportal area and reached a maximal level 72 hr after partial hepatectomy. Moreover, neutralization of VEGF significantly inhibited proliferative activity of hepatocytes (p<0. 0001), as well as sinusoidal endothelial cells (p<0.001), at 48 and 96 hr after partial hepatectomy. Conversely, injection of VEGF significantly promoted proliferative activity of hepatocytes (p<0. 0001) as well as sinusoidal endothelial cells (p<0.0005) at 48 hr after partial hepatectomy. These results suggest that VEGF promotes proliferation of hepatocytes through reconstruction of liver sinusoids by proliferation of sinusoidal endothelial cells. Furthermore, these data point to a new therapeutic strategy, the use of VEGF and other hepatocyte growth factors in fulminant or severe acute hepatitis.

Two-year follow-up study after treatment with lamivudine for chronic hepatitis B: seven cases reported.

2 times baseline) and returned to seropositive for HBV DNA and HBeAg after lamivudine cessation. One of these five patients died of liver failure 3 months after treatment. However, in two of five patients whose alanine aminotransferase (ALT) had rebounded, HBV DNA became undetectable, and the ALT levels markedly decreased 2 years after the end of therapy. Since the disappearance of HBV DNA and stabilization of the ALT level were observed within two patients by 2 years after cessation of treatment, the patients whose ALT had rebounded should be followed up for a long-term period. To confirm the effect of lamivudine, long-term follow-up in many patients is necessary.

Epidemiological study on food intake and Helicobacter pylori infection.

We conducted an epidemiological study to investigate the relation of food intake to Helicobacter pylori (H. pylori) infection in an area endemic for H. pylori. In this study, 365 subjects, 104 men and 261 women, were randomly selected from 7,389 adult (over age 20) inhabitants of town A, Japan. The prevalence of immunoglobulin G (IgG) class antibody to H. pylori (anti-H. pylori) was 83.7% and the prevalence of anti-H. pylori increased with age significantly (P < 0.05). Subjects with anamnesis of gastritis, gastroduodenal ulcer and gastric cancer tended to have a higher anti-H. pylori positive ratio (93.5%) than those without (81.0%). But there was no relationship between anti-H. pylori prevalence and sex, blood type, smoking or drinking habits. Daily intake of foods by food groups, nutrients and the concentrations of serum ingredients were compared between 37 anti-H. pylori-positive and 40 negative subjects selected from 365 inhabitants by matching up according to sex and age. The daily intake of cereals, potatoes and starches, and milks tended to be higher in positive than negative subjects, while the daily intake of algae and tea appeared to be a little higher in negative than in positive subjects. The daily zinc intake of antibody-positive subjects was significantly higher (P < 0.05) than in antibody negative subjects. On the other hand, the daily iron intake in negative subjects was significantly higher (P < 0.05) than in positive subjects. The serum concentrations of copper, zinc, and vitamin E tended to be higher in positive than negative subjects. But there were no significant differences in serum ingredients concentrations between antibody negative and positive subjects. Our findings suggest that iron and zinc intakes may effect on H. pylori infection.

High prevalence of anticardiolipin antibodies in hepatitis C virus infection: lack of effects on thrombocytopenia and thrombotic complications.

Hepatitis C virus (HCV) causes various extrahepatic immunologic abnormalities. Recently, an association between HCV infection and antiphospholipid syndrome, including thrombocytopenia, has been reported. However, the precise relationship between thrombocytopenia and anticardiolipin antibodies in patients with chronic HCV infection is not fully understood; likewise, the association of antiphospholipid syndrome and various liver diseases is not well understood. To evaluate the prevalence and importance of antiphospholipid antibodies in various chronic liver diseases, we determined the levels of anticardiolipin antibodies, platelet numbers, and levels of platelet-associated immunoglobulin G (PA-IgG) and thrombin-antithrombin III complex (TAT) in patients with chronic HCV infection, chronic hepatitis B virus (HBV) infection, and primary biliary cirrhosis (PBC). The prevalence of anticardiolipin antibodies in patients with HCV infection was significantly higher than that in control subjects or individuals with the other liver diseases examined. However, there was no significant correlation between anticardiolipin antibodies and platelet counts or TAT. The frequency of thrombotic complications was similar in anticardiolipin antibody-positive and -negative patients with chronic HCV infection. Further, sera from all but one anticardiolipin antibody-positive HCV patient were negative for phospholipid-dependent anti-beta2 glycoprotein I antibodies. Our results suggest that anticardiolipin antibodies are frequently found in patients with chronic HCV infection, but they do not appear to be of clinical importance. Immunologic disturbances induced by HCV or prolonged tissue damage in systemic organs as a result of the extrahepatic manifestations of HCV infection may induce the production of antibodies to various cardiolipin-binding proteins or phospholipids.

Role of ATP7B in biliary copper excretion in a human hepatoma cell line and normal rat hepatocytes.

BACKGROUND & AIMS: Wilson's disease is a genetic disorder characterized by the accumulation of copper in the body caused by a defect of biliary copper excretion. The Wilson's disease gene has been cloned; however, the precise localization of the gene product (ATP7B) and its role in biliary copper excretion have not been clarified. METHODS: We constructed a chimeric protein between green fluorescent protein (GFP) and ATP7B (GFP-ATP7B) and expressed it in a human hepatoma cell line (Huh7) and isolated rat hepatocytes. The Golgi apparatus, late endosomes, lysosomes, and bile canaliculus were visualized by fluorescence microscopy. Brefeldin A and nocodazole were used to redistribute the Golgi proteins. Bafilomycin A1 was used to analyze the association between GFP-ATP7B and the late endosomes. RESULTS: GFP-ATP7B colocalized with rhodamine-dextran and late endosome markers but not with the Golgi markers, lysosome markers, or a tight junction protein. Brefeldin A and nocodazole redistributed the Golgi proteins, but they did not affect the distribution of ATP7B. CONCLUSIONS: Although it is widely believed that ATP7B is located at the Golgi apparatus, its main localization is in late endosomes. ATP7B seems to translocate copper from the cytosol to the late endosomal lumen, thus participating in biliary copper excretion via lysosomes.

Ursodeoxycholic acid reduces expression of heat shock proteins in primary biliary cirrhosis.

BACKGROUND: To identify injured cells in the liver of patients with primary biliary cirrhosis (PBC) and to determine the effects of ursodeoxycholic acid (UDCA) on these cells, we examined the cellular expression of heat shock proteins (HSPs) in PBC both before and after treatment with UDCA. METHODS: Expression of HSP70 and ubiquitin in PBC livers (n=34) was evaluated immunohistochemically as well as by immunoblot analysis, and compared with chronic viral hepatitis type C (n= 9), primary sclerosing cholangitis (n=8), and controls (n=7). RESULTS: Immunoblot analysis demonstrated a marked expression of HSP70 and ubiquitin in PBC. Immunohistochemical staining for both HSP70 and ubiquitin was observed to be strong in biliary epithelial cells (BECs) and moderate in both hepatocytes and arteries in PBC. Cellular labelling rates for HSP70 and ubiquitin of bile ducts in PBC were significantly higher (p<0.01) than those in chronic viral hepatitis type C, primary sclerosing cholangitis, or controls. The labelling rates for HSP70 and ubiquitin in bile ducts and in hepatocytes were significantly decreased (p<0.01) after treatment with UDCA in PBC. CONCLUSIONS: The present data suggest that BECs and hepatocytes significantly express HSPs even in the early stages of PBC, and that UDCA treatment significantly improves their condition. The immunohistochemical evaluation of HSPs is a valid and sensitive means to identify injured cells in PBC.

A computer program for pharmacokinetics based on maximum likelihood estimation using the gamma distribution with a probability density function: comparison with the normal distribution.

A computer program is described for maximum likelihood estimation within the gamma or normal distribution which can be used to estimate pharmacokinetic parameters. Pharmacokinetic analysis using this proposed program was investigated by the Monte Carlo method. The assumed pharmacokinetic models were a one-compartment intravenous model and an oral model. The simulated drug concentrations were generated using a 10% S.D. based on the gamma or normal distribution. The gamma or normal distribution was adopted as the probability density function (p.d.f.) to estimate model parameters. The Powell method was used to maximize the logarithmic likelihood. There were no differences in the estimated parameters in terms of statistical and frequency distributions between the gamma and normal distributions using the generated data and the p.d.f. distributions. However, the number of failures to calculate the parameters using the p.d.f. with the normal distribution was more than five times that using the gamma distribution. This result suggests that it may be necessary to evaluate the validity of results computed using the maximum likelihood estimation based on a normal distribution as a data error distribution and p.d.f.