bluuebunny/crossref_metadata_2025 huggingface dataset:
Lymphoblastoid interferon alfa-n1 improves the long-term response to a 6-month course of treatment in chronic hepatitis C compared with recombinant interferon alfa-2b: Results of an international randomized controlled trial
Authors: Farrell Geoffrey C. , Bacon Bruce R. , Goldin Robert D.
Published: July 2004

The aim of this study was to compare the short-term and long-term efficacy and safety of lymphoblastoid interferon with a recombinant interferon alfa (IFN-α) in a 24-week treatment course for chronic hepatitis C. One thousand seventy-one patients with chronic hepatitis C were randomized to receive lymphoblastoid IFN-αn1 or recombinant IFN-α2b at the same dosing regimen, 3 million units administered subcutaneously three times a week for 24 weeks. Hepatitis C viral (HCV) genotype (by line probe assay) was determined at baseline, and serum HCV RNA level (by quantitative reverse-transcriptase polymerase chain reaction) was measured at baseline and weeks 24, 48, and 72. Primary end points were normalization of serum alanine aminotransferase (ALT) levels at end of therapy (week 24) and sustained ALT normalization at weeks 48 and 72. Secondary end points were nondetectability of serum HCV RNA at 24, 48, and 72 weeks, and histological improvement at weeks 24 and 72. The two treatment groups were similar with respect to demographic, clinical, and histological variables (10% had cirrhosis at entry), baseline serum HCV RNA levels, and distribution of HCV genotypes. Intent-to-treat analysis showed that ALT response at end of treatment was 35.3% for IFN-αn1 and 37.9% for IFN-α2b (P = .38). Histological improvement and nondetectability of HCV RNA were also similar between the two treatment groups at the end of treatment, as were the type and frequency of reported adverse experiences. Among treatment responders, post-treatment relapse was significantly less frequent with IFN-αn1 than with IFN-α2b. Thus, sustained ALT responses (SR) to IFN-αn1 were significantly more frequent than SR to IFN-α2b (12.0% vs. 7.6% at 48 weeks, P = .02; 10.3% vs. 6.7% at 72 weeks, Pequals; .04). SR were associated with viral loss and histological improvement, and more patients treated with IFN-αn1 were HCV RNA negative at week 72 compared with patients treated with IFN-α2b (P = .03). SR at week 72 were two- to sixfold better with other HCV genotypes relative to type 1, but the improved long-term efficacy of IFN-αn1 compared with IFN-α2b was evident for all major HCV genotypes. It is concluded that IFN-αn1 and IFN-α2b have similar end-of-treatment response rates and safety profiles but the sustained response rate is higher with IFN-αn1. SR to IFN-α treatment are associated with clearance of HCV RNA, and histological improvement was maximal in patients who exhibited sustained ALT normalization and clearance of HCV RNA.
Combination therapy with thymosin α1 and interferon for the treatment of chronic hepatitis C infection: A randomized, placebo-controlled double-blind trial†
Authors: Sherman Kenneth E. , Sjogren Maria , Creager Robin L. , Damiano Melissa A. , Freeman Stephen , Lewey Scot , Davis Dirk , Root Spencer , Weber Frederick L. , Ishak Kamal G. , Goodman Zachary D.
Published: July 2004

Hepatitis C is a major cause of liver disease leading to cirrhosis. Although interferon (IFN) is the only approved therapy, treatment is characterized by low response rates and dose-limiting side effects. We evaluated the addition of thymosin α1 (TA1), an immunomodulatory peptide, to the standard treatment regimen for hepatitis C to determine if combination therapy shows biological activity using outcome measures including normalization of alanine aminotransferase levels, histological activity, and viral load during treatment. We performed a randomized, double-blind, placebo-controlled trial to compare the biological activity of a combination TA1 and IFN with that seen for IFN alone in patients with chronic hepatitis C infection. One hundred nine patients were randomized for intention to treat and received 1.6 mg of TA1 subcutaneously twice weekly and 3 MU of IFN three times weekly; 3 MU of IFN three times weekly and placebo TA1; or placebo for both agents. All patients had chronic HCV infection with confirmation of chronic hepatitis on liver biopsy. Biochemical responders were followed up until alanine aminotransferase (ALT) levels became abnormal or for 26 weeks, and relapsers were retreated for 26 weeks in the same treatment arm. One hundred three patients completed treatment for 26 weeks, and six patients dropped out. The groups were similar with regard to sex, gender distribution, baseline histological activity index (HAI) score, risk factors, and viral titers. End-of-treatment biochemical response was seen in 37.1% of patients treated with combination therapy, 16.2% of patients treated with IFN alone, and 2.7% of untreated controls by intent-to-treat analysis (IFN/TA1 vs. IFN, χ2 = 4.05, P = .04). HCV RNA clearance was seen in 37.1% of IFN/TA1-treated patients and 18.9% of IFN-treated subjects. Mean HCV RNA titers were significantly lower than baseline at weeks 8, 16, and 24 after drug initiation among patients treated with IFN/TA1 but not in the other treatment arms. Histological improvement, as evidenced by a decrease in HAI of more than two points, occurred in the combination therapy arm more frequently than in comparison groups. Cumulative sustained biochemical responses were 14.2% and 8.1% in the IFN/TA1 and IFN arms, respectively, based on an intention-to-treat model. The combination of TA1 and standard IFN treatment for chronic hepatitis C showed evidence of biological activity at the completion of treatment by biochemical, histological, and virological outcome measures. Further research involving longer duration and varied dosing is needed.
Re-treatment of chronic hepatitis C with consensus interferon
Authors: Heathcote Jenny E. , Keeffe Emmet B. , Lee Samuel S. , Feinman Saya V. , Tong Myron J. , Reddy K. R. , Witt Karsten , Blatt Lawrence M.
Published: July 2004

A multicenter, open-label, phase 3 study was conducted in 337 patients with chronic hepatitis C virus (HCV) infection who had either not responded to previous interferon therapy or had relapsed after discontinuation of therapy with either consensus interferon (9 μg) or interferon α-2b (3 million U) three times a week for 24 weeks. Patients were randomized to receive a higher dose of consensus interferon (15 μg) administered subcutaneously three times a week for 24 or 48 weeks and then were observed for an additional 24 weeks. Patients who had relapsed after prior interferon therapy were more likely to have a sustained alanine aminotransferase response and HCV RNA response (as measured by reverse transcription-polymerase chain reaction with a sensitivity of <100 copies/mL) than were patients who had not responded to prior interferon therapy. For relapsers, the sustained HCV RNA response rate was 58% (48 weeks) and 28% (24 weeks). The sustained alanine aminotransferase response for relapsers was 52% (48 weeks) and 39% (24 weeks). The sustained HCV RNA response rate among prior nonresponders was 13% (48 weeks) and 5% (24 weeks), and the sustained alanine aminotransferase response rate for nonresponders was 17% (48 weeks) and 12% (24 weeks). The administration of 15 μg of consensus interferon was well tolerated and was not associated with an increase in the incidence of side effects. These data demonstrate that re-treatment with 15 μg of consensus interferon is safe and effective therapy for patients with chronic hepatitis C who have either not responded to previous interferon therapy or relapsed after discontinuation of interferon therapy.
Re-treatment with interferon alfa of patients with chronic hepatitis C
Authors: Chow Wan-Cheng , Boyer Nathalie , Pouteau Michele , Castelnau Corinne , Martinot-Peignoux Michele , Martins-Amado Veronique , Degos Francoise , Maghinici Crina , Sinegre Martine , Benhamou Jean-Pierre , Degott Claude , Erlinger Serge , Marcellin Patrick
Published: July 2004

Treatment of patients with chronic hepatitis C has had limited success because of relapses and nonresponse to interferon alfa therapy (currently the only established therapeutic agent). A retrospective study was done to determine the efficacy of re-treatment with interferon and the predictors of response in patients who failed to achieve sustained response after one standard course of interferon therapy (3 million units three times a week for 24 weeks). One hundred and eleven patients (47 relapsers and 64 nonresponders), mean age 45 years, were included in the study. Eighteen relapsers and 13 nonresponders received a higher dose (5 MU), and 11 relapsers and 6 nonresponders received a longer duration (48 weeks) of interferon therapy. The remaining patients received the same regimen as the first treatment. Eighty-one percent and 23% of relapsers and nonresponders, respectively, had an end-of-treatment response, and 19% and 3% of the corresponding patient groups had a sustained response to re-treatment. Two patients with breakthrough during their first treatment were the only nonresponders with sustained response after re-treatment. Sustained response was observed only in patients who received an increased dose or duration of interferon therapy. No predictor of sustained response was found. In conclusion, sustained response to re-treatment with interferon was only observed with augmentation of dose or duration of therapy in some relapsers and patients who had breakthrough. Established predictors of response to interferon in naive patients, in particular serum hepatitis C virus RNA and genotype, were not associated with sustained response to re-treatment.
Quantification of the initial decline of serum hepatitis c virus RNA and response to interferon alfa
Authors: Zeuzem Stefan , Lee Jung-Hun , Franke Alexa , Rüster Brigitte , Prümmer Otto , Herrmann Günter , Roth Kurt W.
Published: July 2004

Although several virus- and host-related predictive factors for the response to interferon alfa (IFN-α) have been defined in patients with chronic hepatitis C, no pretreatment parameter can definitely predict the response to antiviral treatment. Assessment of the initial response by quantification of serum hepatitis C virus RNA before and 4 weeks after initiation of therapy may be a clinically applicable and reliable parameter to predict long-term response. Therefore, the aims of the present study were to test the predictive value of a decline in HCV RNA of at least 3 log in the first 4 weeks of treatment (△HCV RNA) in patients treated with 3 × 106units of recombinant IFN-α2a (rIFN-α2a) three times per week subcutaneously and to compare △HCV RNA with other established predictive factors, such as HCV genotype and pretreatment viremia. Serum HCV RNA was measured by a validated quantitative reverse transcription-polymerase chain reaction (RT-PCR). Geno/subtyping of HCV was performed by direct sequencing of the nonstructural (NS) 5B region of PCR-amplified isolates and subsequent phylogenetic analysis. Stable HCV RNA levels (△HCV RNA ≤ 1 log) within the first 4 weeks of IFN-α treatment were present in 42 of 70 patients. A decline in HCV RNA levels between 1 to 3 log and more than 3 log was observed in 9 (13%) and 19 patients (27%), respectively. In 21 of 70 patients (30%), HCV RNA was not detectable at the end of 12 months’ treatment. Three of 26 patients (11%) with a pretreatment viremia of ≤106copies/mL (all HCV subtype 3a) and 6 of 44 patients (14%) with a pretreatment viremia of >106copies/mL (HCV subtypes 1b, 2a, 2c, 3a [two patients], and 4) achieved a virological sustained response to interferon-α2a treatment. All patients with a virological sustained response had an initial △HCV RNA of more than 3 log. In a stepwise discriminant-function analysis, the initial △HCV RNA was confirmed as the strongest predictor of virological sustained response (P< .0001). In conclusion, the data of the present study suggest that IFN-α treatment can be terminated after 4 weeks in patients with a decrease in HCV RNA levels of less than 3 log, when apparent HCV eradication is considered the therapeutic target. The predictive value of △HCV RNA clearly exceeds the significance of HCV genotype and pretreatment viremia as predictors of successful IFN-α treatment.
Increased renal expression of nitric oxide synthase type III in cirrhotic rats with ascites
Authors: Bosch-Marcé Marta , Morales-Ruiz Manuel , Jiménez Wladimiro , Bordas Nuria , Solé Manuel , Ros Josefa , Deulofeu Ramón , Arroyo Vicente , Rivera Francisca , Rodés Juan
Published: July 2004

This article assesses the circulating levels of l-arginine, the renal response to l-arginine infusion, and the renal expression of inducible and constitutive nitric oxide synthase (NOS II and NOS III, respectively) in cirrhotic rats with ascites. Systemic and renal hemodynamics and renal function were measured in basal conditions and following two doses of l-arginine (5 and 10 mg · kg−1 · min for 40 minutes). Renal NOS II and III messenger RNA (mRNA) expression was evaluated in basal conditions by polymerase chain reaction and Northern blot, respectively. Renal NOS II and III protein expression was assessed by Western blot and immunohistochemistry. Plasma concentration of l-arginine was significantly lower in cirrhotic rats than in control rats (48 ± 11 vs. 86 ± 9 μmol/L, P < .025). In both groups l-arginine infusion had no effect on systemic hemodynamics, but markedly increased renal perfusion. This effect was significantly more intense in cirrhotic rats. A very weak signal of similar intensity was found for NOS II mRNA in both groups of animals. However, no NOS II protein expression was detected. In contrast, higher NOS III mRNA abundance and protein expression, which was mainly located in the endothelial lining of the renal arterioles, were found in the kidney of cirrhotic animals. These results indicated increased renal expression of NOS III mRNA and protein, deficient circulating levels of l-arginine, and increased renal hemodynamic response to this amino acid in cirrhotic rats with ascites. Our results suggest that l-arginine supplementation at doses not affecting arterial pressure could have beneficial effects on renal perfusion in cirrhosis
Decreased muscle strength in patients with alcoholic liver cirrhosis in relation to nutritional status, alcohol abstinence, liver function, and neuropathy
Authors: Andersen Henning , Borre Mette , Jakobsen Johannes , Andersen Per Heden , Vilstrup Hendrik
Published: July 2004

To study motor function quantitatively in alcoholic liver cirrhosis muscle strength, liver function, peripheral nerve function, and nutrition were assessed in 24 patients. Isokinetic strength of flexion and extension at elbow, wrist, hip, knee, and ankle and of shoulder abduction and adduction was evaluated and compared with findings in 24 matched healthy subjects. Degree of liver disease was assessed with the Child-Pugh score and the galactose elimination capacity (GEC). Nutritional status was evaluated with an estimation of lean body mass (LBM) from 24-hour urinary creatinine excretions. Peripheral nerve function was evaluated with neurological symptom and disability scores, nerve conduction studies, and quantitative sensory tests summed to obtain a neuropathy rank-sum score (NRSS) for each patient. Combined muscle strength at hip, knee, ankle, shoulder, elbow, and wrist were weakened with 34% (P < .005), 35% (P < .001), 35% (P < .01), 34% (P < .01), 29% (P < .01), and 29% (P < .02), respectively. The median Child-Pugh score was 7 (range, 5-12), and the median duration of alcohol abstinence was 90 days (range, 5-960 days). After multiple linear regression analysis including LBM, Child-Pugh score, GEC, duration of alcohol abstinence, and NRSS, only LBM was correlated to the strength at the knee (r = .79; P < .0001) and at the ankle (r = .63; P < .01). It is concluded that muscle strength is weakened substantially in alcoholic patients with liver cirrhosis and that weakness is related to the severity of malnutrition but not to the severity of liver disease, duration of alcohol abstinence, or neuropathy.
Bacterial infection is independently associated with failure to control bleeding in cirrhotic patients with gastrointestinal hemorrhage
Authors: Goulis John , Armonis Anastasios , Patch David , Sabin Caroline , Greenslade Lynda , Burroughs Andrew K.
Published: July 2004

Bacterial infection is frequently diagnosed in cirrhotic patients with variceal hemorrhage. The aim of this study was to assess the incidence of failure to control bleeding in cirrhotic patients during the first 5 days after the episode of variceal bleeding in relation to the diagnosis of bacterial infection and use of antibiotics. One hundred seventy-seven consecutive admissions for gastrointestinal bleeding in 151 patients were evaluated prospectively. From them, 163 admissions for variceal bleeding in 137 patients were included in the main analysis. Bleeding was managed in a standardized protocol using octreotide or terlipressin with sclerotherapy or band ligation for active bleeding at endoscopy. The end points were defined as in Baveno guidelines related to transfusion requirement or fresh hematemesis after 6 hours from time zero. The standardized screening protocol for bacterial infection consisted of chest radiograph and blood, urine, and ascitic fluid cultures. Active bleeding was reported at endoscopy in 86 admissions (53%). Failure to control bleeding occurred in 76 patient admissions (47%). Empirical antibiotic treatment was used in 113 admissions (69%), whereas in 81% of them (91 admissions, 56%) 102 bacterial infections were documented. Multivariate analysis showed that proven bacterial infection (P < .0001) or antibiotic use (P < .003) as well as active bleeding at endoscopy (P < .001) and Child-Pugh score (P < .02) were independent prognostic factors of failure to control bleeding. The results remained unchanged when all patient admissions with gastrointestinal bleeding of any source were included in the multivariate analysis. Bacterial infection is associated with failure to control variceal bleeding and needs to be evaluated in the planning and analysis of clinical trials.
Cost-effectiveness of ultrasound-guided liver biopsy
Authors: Pasha Tousif , Gabriel Sherine , Therneau Terry , Dickson Rolland E. , Lindor Keith D.
Published: July 2004

The risk of a major complication from “blind” percutaneous liver biopsy is reported to be in the range of 0.24% to 3.8%. In a recent randomized trial, patients whose liver biopsies were performed with ultrasonography had a significant reduction in complications requiring hospitalization compared with patients without ultrasound-guided biopsies (0.5% vs. 2.2%, P < .05). Despite this, routine use of ultrasonography for liver biopsies has not been implemented because of controversies with respect to cost-effectiveness. The aim of our study was to analyze the relative cost-effectiveness of performing ultrasound-guided liver biopsies using decision analysis. A decision tree was constructed to compare a strategy of liver biopsy using ultrasonography with a strategy without ultrasonography. The major outcomes included were minor complications such as pain requiring analgesics and major complications, which require hospitalization. Costs included were direct medical costs from the payer’s perspective. In our baseline model, the cost from complications per patient with and without ultrasonography was $62 and $129, respectively. The marginal effectiveness expressed as the number of major complications avoided was 1.2/100 liver biopsies. The incremental cost to avoid one major complication was $2,731. The model was most sensitive to the frequency of major complications and the additional cost of ultrasonography. Our decision analysis model suggests that ultrasound-guided liver biopsy is cost-effective. Future studies assessing the efficacy of image-guided liver biopsies should be conducted.
Tumor necrosis factor and interleukin-6 in spontaneous bacterial peritonitis in cirrhosis: Relationship with the development of renal impairment and mortality
Authors: Navasa Miguel , Follo Antonio , Filella Xavier , Jiménez Wladimiro , Francitorra Anna , Planas Ramón , Rimola Antoni , Arroyo Vicente , Rodés Joan
Published: July 2004

Spontaneous bacterial peritonitis (SBP) is associated with an important production of inflammatory mediators. However, it is unknown whether there is a relationship between the abdominal production of these mediators and the development of renal impairment, one of the most important prognostic parameters in spontaneous bacterial peritonitis. We studied 52 cirrhotic patients at diagnosis and resolution of the infection, by measuring endotoxin, tumor necrosis factor (TNF), and interleukin-6 (IL-6) levels in plasma and ascitic fluid. Thirteen patients (25%) developed renal impairment. Patients developing renal impairment showed significantly higher plasma and ascitic fluid cytokine levels at diagnosis of infection than patients who did not (plasma TNF-α: 96.0 ± 38.7 vs. 39.1 ± 3.6 pg/mL, P = .0209; ascitic fluid TNF-α: 474.5 ± 118.1 vs. 160.8 ± 42.7 pg/mL, P = .0173; plasma IL-6: 6,635 ± 2,897 vs. 458 ± 109 pg/mL, P = .0004; ascitic fluid IL-6: 182,559 ± 47,328 vs. 39,250 ± 10,803 pg/mL, P = .0001). Independent predictors of development of renal impairment at diagnosis were: renal failure (blood urea nitrogen > 30 mg/dL or serum creatinine > 1.5 mg/dL) (P < .001), IL-6 levels in ascitic fluid (P < .001), and mean arterial pressure (P < .05). Ten of the 13 (77%) patients who developed renal impairment died during hospitalization, but only 2 of the 39 (5%) patients who did not (P= .0001). In addition, renal failure at diagnosis of the infection was the only independent predictor of hospital mortality (P < .001). In conclusion, the inflammatory response to the infection may be an important mechanism of renal impairment and the associated mortality in SBP.
Inhibition of establishment and growth of mouse liver metastases after treatment with interferon gamma and β-1,3-d-glucan
Authors: Sveinbjørnsson Baldur , Rushfeldt Christian , Seljelid Rolf , Smedsrød Bård
Published: July 2004

The purpose of this study was to investigate the combined antitumor effect of aminated β-1,3-d-glucan (AG) and interferon-gamma (IFN-γ) in an experimental liver metastasis model. Liver metastases were established by inoculation of C-26 colon carcinoma cells into the superior mesenteric vein of syngeneic mice. Treatment of mice started 24 hours after inoculation of tumor cells by daily intravenous injections of either AG, IFN-γ, or a combination of both for a duration of 6 days. The resultant liver metastases were then quantified after an additional period of 11 days. Combination of IFN-γ and AG inhibited the growth of liver metastases almost entirely. IFN-γ was also very efficient, while AG alone did not exert any significant antitumor effect. These results, along with histological studies from mice receiving AG and IFN-γ, indicated that activation and recruitment of liver macrophages may be a part of the mechanism responsible for the inhibition of metastatic growth observed in this study.
Glutathione protects metastatic melanoma cells against oxidative stress in the murine hepatic microvasculature
Authors: Anasagasti Miren J. , Martin Javier J. , Mendoza Lorea , Obrador Elena , Estrela Jose M. , McCuskey Robert S. , Vidal-Vanaclocha Fernando
Published: July 2004

Calcein-labeled B16 melanoma (B16M) cells were injected intraportally, and in vivo video microscopy was used to study the distribution and damage of cancer cells arrested in the liver microvasculature over a period of 4 hours. The contribution of glutathione (GSH)-dependent antioxidant machinery to the possible oxidative stress-resistance mechanism of B16M cell was determined by in vitro incubation with the selective inhibitor of GSH synthesis l-buthionine (S,R)-sulphoximine (BSO) before B16M cell injection in untreated and 0.5-mg/kg lipopolysaccharide (LPS)-treated mice. In addition, untreated and LPS-treated isolated syngeneic hepatic sinusoidal endothelial cells (HSE) were used to determine in vitro their specific contribution to B16M cell damage. Trauma inherent to intrasinusoidal lodgement damaged 35% of B16M cells in both normal and LPS-treated mouse liver. The rest of the arrested B16M cells remained intact in normal liver for at least 4 hours, although their damaged cell percentage significantly (P < .05) increased since the second hour in normal mice injected with BSO-treated cells and since the first hour in LPS-treated mice given untreated cells. Recombinant human interleukin-1 receptor antagonist (rHuIL-1-Ra) given to mice 15 minutes before LPS significantly (P < .05) abrogated B16M cell damage. On the other hand, 40% of the B16M cells co-cultured with unstimulated HSE and 70% of the co-cultured with LPS-treated HSE became sensitive to endothelial cell-mediated damage after BSO treatment. These results demonstrate that a high intracellular level of GSH protects B16M cells from possible in vivo and in vitro sinusoidal cell-mediated oxidative stress, contributing to the mechanism of metastatic cell survival within the hepatic microvasculature.
pp60c-src Activation in hepatocellular carcinoma of humans and LEC rats
Authors: Masaki Tsutomu , Okada Masato , Shiratori Yasushi , Rengifo William , Matsumoto Kozou , Maeda Shinn , Kato Naoya , Kanai Fumihiko , Komatsu Yutaka , Nishioka Mikio , Omata Masao
Published: July 2004

For the related Src kinases, a close correlation exists between elevated tyrosine kinase activity and cell transformation. However, the involvement of pp60
c-src
in hepatocellular carcinoma (HCC) remains obscure. The aim of this study was to evaluate whether pp60
c-src
tyrosine kinase activity is elevated in HCC. We analyzed the kinase activity of pp60
c-src
in normal liver tissue, chronic hepatitis liver tissue, and tumorous and adjacent nontumorous portions of HCC tissue from patients and Long-Evans cinnamon (LEC) rats that are known to develop liver cancer spontaneously. The kinase activity of pp60
c-src
was rarely detected in the normal human liver tissue and chronic hepatitis liver tissue, but it was elevated in tumorous and nontumorous portions of HCC tissue. Furthermore, the kinase activity of pp60
c-src
was significantly elevated in tumorous tissues compared with nontumorous tissues. The kinase activity of pp60
c-src
was also higher in poorly differentiated HCC. In addition, the kinase activity of pp60
c-src
increased proportionately with the development of HCC of LEC rats. Our results suggest that activation of the protooncogene product pp60
c-src
may play an important role in the malignant transformation of hepatocytes in human and LEC rats, and that it may be closely related to the histopathological grading of human HCC.
Effect of antioxidants, resveratrol, quercetin, and N -acetylcysteine, on the functions of cultured rat hepatic stellate cells and kupffer cells
Authors: Kawada Norifumi , Seki Shuichi , Inoue Masayasu , Kuroki Tetsuo
Published: July 2004

Effects of antioxidants, resveratrol, quercetin, and N-acetylcysteine (NAC) on the functions of cultured rat hepatic stellate cells and Kupffer cells were studied. These compounds dose-dependently suppressed serum-dependent proliferation of stellate cells as determined by [3H]thymidine and 5-bromo-2′-deoxyuridine uptake. Expression of smooth muscle α-actin was suppressed by a high dose of resveratrol and quercetin. These phenolic compounds also suppressed inositol phosphate metabolism, tyrosine phosphorylation, and mitogen-activated protein (MAP) kinase activation in platelet-derived growth factor/BB-stimulated stellate cells. Moreover, the phenolic compounds selectively reduced the level of cell cycle protein cyclin D1 in stellate cells. Thus, resveratrol and quercetin might inhibit stellate cell activation by perturbing signal transduction pathway and cell cycle protein expression, whereas mechanism of potent antiproliferative effect of NAC remains to be elucidated. On the other hand, kinetic analysis showed that production of nitric oxide (NO) and tumor necrosis factor α (TNF-α) by lipopolysaccharide-stimulated Kupffer cells was strongly inhibited by resveratrol and quercetin but not by NAC. Although expression of messenger RNAs for inducible NO synthase and TNF-α was not affected by the phenolic compounds, cellular levels of inducible NO synthase and TNF-α secretion were suppressed significantly, indicating the posttranscriptional process of generating these proteins might be affected predominantly by these phenolic compounds. Thus, NAC and these phenolic compounds may have therapeutic potential against liver injury by regulating functions of hepatic stellate cells and Kupffer cells.
Interleukin 1β and interleukin 6, but not tumor necrosis factor α, inhibit insulin-stimulated glycogen synthesis in rat hepatocytes
Authors: Kanemaki Toshiki , Kitade Hiroaki , Kaibori Masaki , Sakitani Kazushige , Hiramatsu Yoshifumi , Kamiyama Yasuo , Ito Seiji , Okumura Tadayoshi
Published: July 2004

Recent evidence indicates that inflammatory cytokines are involved in changes of blood glucose concentrations and hepatic glucose metabolism in infectious diseases, including sepsis. However, little is known regarding how cytokines interact with glucoregulatory hormones such as insulin. The objective of the present study is to investigate if and how cytokines influence insulin-stimulated glycogen metabolism in the liver. Interleukin 1β (IL-1β) and interleukin 6 (IL-6) markedly inhibited the increase of glycogen deposition stimulated by insulin in primary rat hepatocyte cultures; however, tumor necrosis factor α had no effect. Labeling experiments revealed that both cytokines counteracted insulin action by decreasing [14C]-glucose incorporation into glycogen and by increasing [14C]-glycogen degradation. Furthermore, it was discovered that IL-1β and IL-6 inhibited glycogen synthase activity and, in contrast, accelerated glycogen phosphorylase activity. In experiments with kinase inhibitors, serine/threonine kinase inhibitor K252a blocked IL-1β- and IL-6-induced inhibitions of glycogen deposition, as well as glycogen synthase activity, whereas another kinase inhibitor staurosporine blocked only IL-6-induced inhibition. Tyrosine kinase inhibitor herbimycin A blocked only IL-1β-induced inhibition. These results indicate that IL-1β and IL-6 regulate insulin-stimulated glycogen synthesis through different pathways involving protein phosphorylation in hepatocytes. They may mediate the change of hepatic glucose metabolism under pathological and even physiological conditions by modifying insulin action in vivo.
Zonated expression of cytokines in rat liver: Effect of chronic ethanol and the cytochrome P450 2E1 inhibitor, chlormethiazole
Authors: Fang Che , Lindros Kai O. , Badger Thomas M. , Ronis Martin J.J. , Ingelman-Sundberg Magnus
Published: July 2004

The release of proinflammatory cytokines by endotoxins and during oxidative stress is considered to be an early key step in the pathogenesis of alcoholic liver disease (ALD). Ethanol-inducible cytochrome P450 2E1 (CYP2E1) has potentially pro-oxidative and toxicological properties, and its expression is restricted to the perivenous region of liver. We investigated zonal differences of cytokine expression in rat liver and how these are affected by alcohol exposure and by chlormethiazole (CMZ), a transcriptional and posttranslational inhibitor of hepatic CYP2E1. Periportal and perivenous cell lysates were obtained by the digitonin pulse technique from livers of rats treated with ethanol and CMZ for 38 days. Cytokine expression on the mRNA and protein levels was quantified using competitive polymerase chain reaction (PCR) and Western blot, respectively. Chronic ethanol treatment significantly increased the expression of CYP2E1, microsomalp-nitrophenol hydroxylase activity (indicative for CYP2E1 enzyme activity), and the expression of transforming growth factor β1(TGF-β1), tumor necrosis factor α (TNF-α), and interleukin (IL)-1β (1.4- to 4.6-fold). In contrast, ethanol caused a decrease in IL-4 expression and had no influence on IL-6 expression. CMZ treatment caused a reduction in hepatic CYP2E1 expression and in the ethanol-induced cytokine expression by 40% to 60%. Expression of IL-6, IL-2, and IL-4 mRNA occurred preferentially in the periportal region, whereas ethanol caused a pronounced increase in the perivenous expression of TGF-β1, which was inhibited by CMZ as monitored both on the mRNA and protein levels. These results show the zonated expression of several cytokines and the counteraction of CMZ on all effects of ethanol on cytokine expression. The data further strengthen a link between increased CYP2E1 expression and enhanced cytokine expression as important events in the development of ALD.
Time course study of the influence of acute iron overload on kupffer cell functioning and hepatotoxicity assessed in the isolated perfused rat liver
Authors: Tapia Gladys , Troncoso Pilar , Galleano Monica , Fernandez Virginia , Puntarulo Susana , Videla Luis A.
Published: July 2004

This study tested the hypothesis that acute iron overload (500 mg/kg) alters Kupffer cell functioning by promoting free radical reactions associated with the respiratory burst of liver macrophages, assessed in the isolated perfused rat liver under conditions of Kupffer cell stimulation by carbon infusion and inactivation by gadolinium chloride pretreatment. Total serum and hepatic iron levels were markedly enhanced compared with control values 2 to 24 hours after iron treatment. Total liver O2 uptake progressively increased by iron overload reaching a maximum at 6 hours after treatment, an effect that was completely blocked by GdCl3. Concomitantly, carbon-induced GdCl3-sensitive liver O2 uptake was either enhanced by 119% at 2 hours after iron overload, diminished compared with control values at 4 hours, or abolished at 6 hours. Iron-overloaded rats showed a marked increase in liver sinusoidal lactate dehydrogenase efflux at 4 and 6 hours after treatment, an effect that is exacerbated by carbon infusion and reduced (69%-89%) by GdCl3 pretreatment. Both basal and carbon-induced lactate dehydrogenase effluxes returned to control values at 24 hours after iron overload concomitantly with depression of the basal O2 uptake, without development of iron-induced GdCl3-sensitive respiration or Kupffer cell activation by carbon infusion. It is concluded that iron overload induces a derangement in the Kupffer cell functional status represented by early increases in macrophage-dependent respiratory activity, which may contribute to the concomitant liver injury that developed and to the impairment of both hepatic respiration and the macrophage response to particle stimulation observed at later times after treatment.
Increased lipid peroxidation and impaired antioxidant enzyme function is associated with pathological liver injury in experimental alcoholic liver disease in rats fed diets high in corn oil and fish oil
Authors: Polavarapu Rathnagiri , Spitz Douglas R. , Sim Julia E. , Follansbee Mark H. , Oberley Larry W. , Rahemtulla Amir , Nanji Amin A.
Published: July 2004

Increased hepatic oxidative stress with ethanol administration is hypothesized to be caused either by enhanced pro-oxidant production or decreased levels of antioxidants or both. We used the intragastric feeding rat model to assess the relationship between hepatic antioxidant enzymes and pathological liver injury in animals fed different dietary fats. Male Wistar rats (5 per group) were fed ethanol with either medium-chain triglycerides (MCTE), palm oil (PE), corn oil (CE), or fish oil (FE). Control animals were fed isocaloric amounts of dextrose instead of ethanol with the same diets. The following were evaluated in each group: liver pathology, lipid peroxidation, manganese superoxide dismutase (MnSOD) levels, copper-zinc SOD (CuZnSOD) levels, glutathione peroxidase (GPX) levels, and catalase (CAT) levels. All enzymes were evaluated using activity assays and immunoblots. Rats fed FE showed the most severe pathology (fatty liver, necrosis, and inflammation), those fed CE showed moderate changes, those fed PE showed fatty liver only, and those fed MCTE were normal. Parameters indicative of lipid peroxidation (conjugated dienes and thiobarbituric acid-reactive substances) were also greater in rat livers from animals fed the diets high in polyunsaturated fatty acids (CE and FE). CuZnSOD, GPX, and CAT activities showed an inverse correlation (r = −.92, P < .01) with severity of pathological injury, with the lowest levels for both enzymes found in FE-fed rats. Decreased enzyme activity in CE- and FE-fed rats was accompanied by similar decreases in immunoreactive protein. Ethanol administration did not cause significant decreases in enzyme activity in groups that showed no necroinflammatory changes (MCTE and PE). MnSOD activity showed no significant change in any ethanol-fed group. Our results show that decreases in CuZnSOD, GPX, and CAT occur in rats showing pathological liver injury and also having the highest levels of lipid peroxidation. These results suggest that feeding dietary substrates that enhance lipid peroxidation can exacerbate both ethanol-induced oxidative damage as well as necroinflammatory changes. The decrease in activity of antioxidant enzymes observed in animals fed diets high in polyunsaturated fatty acids and ethanol could possibly increase the susceptibility to oxidative damage and further contribute to ethanol-induced liver injury.
Cyclic adenosine monophosphate-mediated protection against bile acid-induced apoptosis in cultured rat hepatocytes
Authors: Webster Cynthia R.L. , Anwer Sawkat M.
Published: July 2004

Cyclic adenosine monophosphate (cAMP) has been shown to modulate apoptosis. To evaluate the role of cAMP in bile acid-induced hepatocyte apoptosis, we studied the effect of agents that increase cAMP on the induction of apoptosis by glycochenodeoxycholate (GCDC) in cultured rat hepatocytes. GCDC induced apoptosis in 26.5% ± 1.1% of hepatocytes within 2 hours. Twenty-minute pretreatment of hepatocytes with 100 μmol/L 8-(4-chlorothiophenyl) cAMP (CP-cAMP) resulted in a reduction in the amount of apoptosis to 35.2% ± 3.8% of that seen in hepatocytes treated with GCDC alone. Other agents that increase intracellular cAMP, including dibutyryl cAMP (100 μmol/L), glucagon (200 nmol/L), and a combination of forskolin (20 μmol/L) and 3-isobutyl-1-methylxanthine (20 μmol/L), also inhibited GCDC-induced apoptosis to a similar extent. Pretreatment with the protein kinase A (PKA) inhibitor, KT5720, prevented the protective effect of CP-cAMP and inhibited CP-cAMP-induced activation of PKA activity. Inhibitors of phosphatidylinositol 3-kinase (PI3K), wortmannin (50 nmol/L), or Ly 294002 (20 μmol/L) also prevented the cytoprotective effect of cAMP. PI3K assays confirmed that wortmannin (50 nmol/L) inhibited PI3K activity, while CP-cAMP had no effect on the activity of this lipid kinase. GCDC increased mitogen-activated protein kinase (MAPK) activity, but had no effect on stress-activated protein kinase (SAPK) activity in hepatocytes. cAMP decreased basal and GCDC-induced MAPK activity and increased SAPK activity. The MAPK kinase inhibitor, PD 98059, inhibited both GCDC-mediated MAPK activation and GCDC-induced apoptosis. In conclusion: 1) agents that increase intracellular cAMP protect against hepatocyte apoptosis induced by hydrophobic bile acids; 2) activation of MAPK by GCDC may be involved in bile acid-induced apoptosis; and 3) cAMP-mediated cytoprotection against bile acid-induced apoptosis appears to involve PKA, MAPK, and PI3K.
The effect of N -acetylcysteine on oxygen transport and uptake in patients with fulminant hepatic failure
Authors: Walsh Timothy S. , Hopton Patrick , Philips Barbara J. , Mackenzie Simon J. , Lee Alistair
Published: July 2004

We have investigated the effect of N-acetylcysteine on hemodynamic variables, oxygen delivery (Do
2), oxygen consumption (Vo
2), and oxygen extraction in patients with fulminant hepatic failure using independent methods of determining Do
2 and Vo
2, thereby eliminating the effect of mathematical coupling, which may have biased previous studies. In 11 patients with severe fulminant hepatic failure, we documented the hemodynamic effects of N-acetylcysteine during the first 5 hours of a standard infusion regime and simultaneously measured Vo
2 using a method based on respiratory gas analysis. We related physiological changes to plasma N-acetylcysteine concentrations, and compared this group with 7 patients who received placebo infusions. A variable hemodynamic response to N-acetylcysteine was observed that did not differ significantly in comparison with the placebo group, and did not correlate with plasma drug concentrations. The most significant relationship observed between Do
2 and Vo
2 in any patient predicted a 13-mL · min−1 · m−2increase in Vo
2 when Do
2 increased by 100 mL · min−1 · m−2; in 8 patients, Vo
2 was independent of Do
2 over the range observed. In the group that received N-acetylcysteine, a small (mean 6 [SD 6] mL · min−1 · m−2) increase in Vo
2 occurred in comparison with baseline after 1 hour of infusion (P < .01), but changes were not significantly different from the placebo group and were not sustained. N-Acetylcysteine infusion did not increase oxygen extraction or result in an improvement in whole-blood lactate levels or base excess during the study period. We conclude that N-acetylcysteine infusion does not result in clinically relevant improvements in global Vo
2, or in clinical markers of tissue hypoxia in patients with severe fulminant hepatic failure.
Chylomicrons alter the hepatic distribution and cellular response to endotoxin in rats
Authors: Harris Hobart W. , Rockey Don C. , Chau Phuonglan
Published: July 2004

Chylomicrons (CM) can bind endotoxin (lipopolysaccharide [LPS]), forming CM-LPS complexes, and protect against endotoxic shock and death in rodent models of gram-negative sepsis. The liver appears to play a central role in this process, as demonstrated by the increased uptake of LPS by this organ. We examined the effect of CM on the uptake and cellular response to injected125I-LPS by hepatocytes and hepatic nonparenchymal cells. Whereas CM increased the uptake of LPS by both hepatocytes and Kupffer cells, the increase was proportionately greater in hepatocytes than Kupffer cells. Importantly, CM-LPS complexes inhibited inducible nitric oxide synthase (iNOS) mRNA expression and NO production in Kupffer cells and endothelial cells, reducing mRNA levels by 45% to 50% as compared with LPS alone. CM-bound LPS also reduced NO production by hepatocytes in response to cytokine stimulation. Lastly, CM-LPS complexes yielded a concentration-dependent inhibition of LPS-induced tumor necrosis factor α (TNF-α) production by Kupffer cellsin vitro. These data indicate that the mechanism by which CM protect against endotoxicity may involve an increased uptake of LPS by hepatocytes. Moreover, uptake of CM-bound LPS by liver cells attenuates the capacity of these cells to respond to proinflammatory stimulation. These results highlight important anti-inflammatory properties of CM.
Hepatocyte growth factor stimulates synthesis of lipids and secretion of lipoproteins in rat hepatocytes
Authors: Kaibori Masaki , Kwon A-H. , Oda Michio , Kamiyama Yasuo , Kitamura Naomi , Okumura Tadayoshi
Published: July 2004

We have reported that infusion of recombinant human hepatocyte growth factor (rhHGF) stimulates liver regeneration after hepatectomy in cirrhotic rats and increases the level of serum lipids and secretion of very-low density lipoprotein (VLDL). Studies were now performed to determine whether rhHGF directly influences lipid synthesis and its secretion in cultured rat hepatocytes. Isolated cells were cultured in the presence or absence of rhHGF (20 ng/mL) for 2 days. During the first 12 hours, rhHGF transiently inhibited the release of lipids (triacylglycerol, total cholesterol, and phospholipids), but stimulated their releases with maximal levels achieved at 36 hours. [3H]-glycerol experiment with the transcriptional and translational inhibitors revealed that rhHGF stimulatedde novosynthesis of lipids by affecting activities of lipid metabolic gene. [35S]-Methionine experiment also revealedde novosynthesis of apolipoprotein B by rhHGF. Furthermore, lipid analysis of lipoprotein fractions in the conditioned medium showed that rhHGF enhanced levels of triacylglycerol, total cholesterol, and phospholipids by 50% to 200% in both VLDL and low-density lipoproteins (LDL)/high-density lipoprotein (HDL). Genistein, a tyrosine kinase inhibitor, blocked the secretion of VLDL, as well as synthesis of lipids and apolipoprotein B stimulated by rhHGF. These results indicate that HGF likely stimulates lipid biosynthesis and lipoprotein secretion in hepatocytes through its tyrosine kinase-associated receptor,c-met, and accelerates the progress of cell maturation in liver regeneration.
Thrombin activates two stress-activated protein kinases, c-Jun N-terminal kinase and p38, in HepG2 cells
Authors: Mitsui Hiroshi , Maruyama Toshiyuki , Kimura Satoshi , Takuwa Yoh
Published: July 2004

Recently identified c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase are activated by stimuli of various cellular stresses, cytokines, and growth factors. Strong activation of JNK was reported in the regenerating liver, implicating JNK in growth stimulation of hepatocytes. However, it is not known which factors regulate JNK activity in liver cells. In this study, we examined activation of JNK and p38 in HepG2 cells stimulated with heterotrimeric G protein-coupled receptor agonists known as mitogens. Thrombin, lysophosphatidic acid (LPA), and bradykinin (BK) stimulated extracellular signal-regulated protein kinase to similar extents, indicating that HepG2 cells have cell surface receptors for these agonists, which are coupled to intracellular signaling pathways. In contrast, only thrombin strongly activated JNK and p38. Thrombin-induced activation of JNK and p38 peaked at 30 minutes and 15 minutes with maximal stimulation of 13- and 4-fold increases, respectively. LPA and BK failed to activate JNK at all and activated p38 only slightly. Interestingly, thrombin-induced JNK activation was inhibited by protein kinase C down-regulation and the addition of a specific protein kinase C inhibitor. Short-term stimulation of cells with an active phorbol ester also induced JNK activation in HepG2 cells. These results indicate that thrombin is a relatively strong activator for JNK and p38 and might play a role in the regulation of activities of JNK and p38 in liver cells.