bluuebunny/crossref_metadata_2025 huggingface dataset:
Curative Resection of Colorectal Adenocarcinoma: Multivariate Analysis of 5‐Year Follow‐up
Authors: Han‐Shiang Chen
Published: August 2002

The purpose of this study was to evaluate the influence of clinicopathologic factors on colorectal cancer, especially the age factor. From 1986 to 1992 a total of 2082 cases of colorectal cancers underwent operation in our institution. After exclusion of familial adenomatous polyposis, multiple cancer, Dukes' D stage, and nonadenocarcinoma patients, there were 1124 patients with single colorectal adenocarcinoma who had undergone curative operation; 1110 cases were included in the study after exclusion of surgical mortalities (14 cases, 1.2%). Age distribution ranged from 19 to 91 years (mean 58 years). The patients were divided into three age groups: < 40 years (grade 1), 40–69 years (grade 2), ≥ 70 years (grade 3); other clinicopathologic factors including gender, tumor gross type, location, pathology, and stage were also evaluated in the study. The colonic/rectal cancer ratio was 1.00:1.74, and that of the male/female distribution was 1.00:0.84. The overall 5‐year cancer‐free rate was 69.9% after curative resection. The young age (< 40 years) patients comprised more women (53.6%) and had a colon location in 41%. Although they had a higher percentage of scirrhous type lesions (1.8%), worse histology (17%), and more advanced stage (49.1%) than the older groups, their survival rate was only slightly lower than the other two groups (67% vs. 70% and 72%, respectively), which was not statistically significant (p= 0.83). By univariate analysis, the factors that influenced the 5‐year cancer‐free rate were gender (p= 0.031), tumor location (p= 0.003), gross type (p= 0.000), pathology (p= 0.000), and stage (p= 0.001). The independent factors determined for the 5‐year cancer‐free rate after multivariate analysis were similar to those assessed by univariate analysis. There 5‐year survival of colorectal adenocarcinoma was not poorer in young patients. Poor survival factors were male gender, rectal location, scirrhous type, poor and mucinous histology, and advanced stage (Dukes' C) found at curative resection for colorectal adenocarcinoma.
Video‐assisted Thoracoscopic Lobectomy Achieves a Satisfactory Long‐term Prognosis in Patients with Clinical Stage IA Lung Cancer
Authors: Sugi Kazuro , Kaneda Yoshikazu , Esato Kensuke
Published: August 2002

We designed a prospective trial to determine the long‐term prognosis of video‐assisted thoracoscopic (VATS) lobectomy versus conventional lobectomy for patients with clinical stage IA (T1N0M0) lung cancer. Between January 1993 and June 1994, 100 consecutive patients with clinical stage IA non‐small cell lung carcinoma underwent either conventional lobectomy through an open thoracotomy (open group; n= 52) or VATS lobectomy (VATS group; n= 48). Lymph node dissections were performed in a similar manner in both groups. No significant differences were observed in the number of dissected lymph nodes between the 2 groups. Pathologic N1 and N2 disease was found in 3 and 1 patients, respectively, from the open group, and in 2 and 1 patients, respectively, from the VATS group. During the follow‐up period, distant metastases and local or regional recurrences developed in 7 and 3 of the open group patients, respectively, and in 2 and 3 of the VATS group patients, respectively. Two and one of the open and VATS group patients developed second primary cancers, respectively. The overall survival rates 5 years after surgery were 85% and 90% in the open and VATS groups, respectively (log‐rank test, p= 0.74; generalized Wilcoxon test, p= 0.91). VATS lobectomy with lymph node dissection achieved an excellent 5‐year survival, similar to that achieved by the conventional approach.
Clinicopathologic Correlation of p53 Protein Overexpression in Adenoma and Carcinoma of the Ampulla of Vater
Authors: Park Sun Hoo , Kim Yong Il , Park Yong Hyun , Kim Sun Whe , Kim Ki Whan , Kim Yong Tae , Kim Woo Ho
Published: August 2002

It has been well documented that ampullary carcinoma arises from a precancerous lesion, but there have been few studies concerning changes at the molecular level during the adenoma‐carcinoma sequence. In this study, p53 overexpression during the progression of carcinoma was compared and the relation between p53 expression and prognosis was analyzed. Ninety‐four cases of adenocarcinoma of the ampulla of Vater were reviewed histopathologically and examined for overexpression of p53 protein using the DO‐7 (mouse monoclonal; DAKO, Glostrup, Denmark) antibody. The correlation of p53 overexpression with the existence of adenoma, clinical stage, histologic grade, and overall survival was investigated. The proportion of p53‐positive cases among normal mucosa, adenoma, early stage carcinoma (I and II), advanced stage carcinoma (III and IV), and metastatic lesion was 0% (0/94), 14.3% (6/42), 32.3% (20/62), 53.1% (17/32), and 63.3% (19/30), respectively. The existence of adenoma or histologic grade of carcinoma did not correlate with p53 overexpression. The carcinoma having adenomatous component was more common in early stages (54.8% in stages I and II, 25% in stages III and IV; p= 0.006) and in well‐differentiated carcinoma (p= 0.001). The existence of adenoma or p53 overexpression did not independently correlate with prognosis. In contrast, the p53 overexpressed group without adenoma showed a worse prognosis than the remaining patients (p= 0.0006) and this trend was still demonstrable when the groups were compared stage by stage. In ampullary carcinoma, p53 abnormality occurs during malignant transformation from the adenoma and continues during the tumor progression in carcinoma. The clinical prognosis of de novo carcinomas with p53 overexpression was worse than that of the remaining patients.
Hereditary thrombophilia as a cause of Budd-Chiari syndrome: A study from Western India
Authors: Mohanty Dipika , Shetty Shrimati , Ghosh Kanjaksha , Pawar Aruna , Abraham Phillip
Published: August 2002

The inherited deficiencies of protein C, protein S, antithrombin III, factor V Leiden mutation, prothrombin gene polymorphism, and antiphospholipids were studied in 53 Budd-Chiari syndrome (BCS) and 33 portal vein thrombosis (PVT) cases and compared with 223 age- and sex-matched controls. Protein C deficiency was detected in 7 (13.2%), protein S in 3 (5.7%), and antithrombin III in 2 (3.8%) of the BCS cases. Factor V Leiden was the most common risk factor, i.e., 14 of 53 (26.4%) in BCS cases followed by protein C, as compared with PVT cases, i.e., 2 of 33 (6.06%) and controls, i.e., 5 of 223 (2.3%). In PVT cases, protein C deficiency was present in 3 (9.09%), protein S deficiency in 1 (3.03%), and factor V Leiden mutation in 2 (6.06%) of the cases. The prothrombin gene polymorphism was not found in either the controls or the patients. The antiphospholipids were seen in 11 (20.75%) of the BCS cases and 6 (18.18%) of the PVT cases. Other acquired risk factors like pregnancy, surgery, and oral contraceptives were present in 8 (15.09%) of BCS and 3 (9.09%) of PVT cases. Thus overall, 59% of the BCS and 30% of the PVT cases could be explained by at least one of the etiologic factors studied.
Disrupted signaling and inhibited regeneration in obese mice with fatty livers: Implications for nonalcoholic fatty liver disease pathophysiology
Authors: Yang Shi Qi , Lin Hui Zhi , Mandal Aloke K. , Huang Jiawen , Diehl Anna Mae
Published: August 2002

The impaired regenerative capacity of fatty livers might promote the progression of nonalcoholic fatty liver disease (NAFLD). To identify mechanisms involved, regenerative responses were compared in normal mice and ob/ob mice (a model for NAFLD) after partial hepatectomy (PH). We hypothesized that the usual PH activation of oxidant-sensitive, growth-regulatory kinase cascades would be abnormal in fatty hepatocytes, which have adapted to chronic oxidant stress, and expected that this might interfere with the induction of proliferative- and stress-related genes. The normal coordinated induction of Jun N-terminal kinases (Jnks) and extracellular regulated kinases (Erks) does not occur after PH in ob/ob mice, which cannot activate Jnks but can superinduce Erks. Jnk inhibition is associated with enhanced activation of Akt, which inhibits phosphoenolpyruvate carboxykinase (PEPCK) induction, causing severe hypoglycemia and increased lethality in the ob/ob group. Activation of nuclear factor κB (NF-κB) is also inhibited, but liver damage is increased only modestly, perhaps because Akt-regulated survival factors are protective. Despite enhanced Erk activity, induction of cyclin D-1, an NF-κB target gene, is abolished and this, together with hyperphosphorylated signal transducer and activator of transcription-3 (Stat-3) and reduced adenosine triphosphate (ATP) levels, arrests fatty hepatocytes in G1. Thus, in mice with NAFLD that have adapted hepatocyte signaling mechanisms to survive chronic oxidative stress, the cellular response to an acute regenerative stimulus is altered. This contributes to NAFLD pathophysiology by inhibiting proliferation, increasing injury, and limiting function in fatty livers.
High glucose and hyperinsulinemia stimulate connective tissue growth factor expression: A potential mechanism involved in progression to fibrosis in nonalcoholic steatohepatitis
Authors: Paradis Valerie , Perlemuter Gabriel , Bonvoust Franck , Dargere Delphine , Parfait Beatrice , Vidaud Michel , Conti Marc , Huet Stephane , Ba Nathalie , Buffet Catherine , Bedossa Pierre
Published: August 2002

Nonalcoholic steatohepatitis (NASH) may progress to liver fibrosis and cirrhosis. Mechanisms directly involved in the development of fibrosis have been poorly investigated. Because connective tissue growth factor (CTGF) is an intermediate key molecule involved in the pathogenesis of fibrosing chronic liver diseases and is potentially induced by hyperglycemia, the aims of this study were to (1) study the expression of CTGF in vivo both in human liver biopsy specimens of patients with NASH and in an experimental model of obesity and type II diabetes (Zucker rats); and (2) analyze the effects of hyperglycemia and insulin in vitro on hepatic stellate cells. In vivo, CTGF overexpression was observed in the liver tissue of all of the 16 patients with NASH. CTGF immunostaining was mild in 7 cases (44%) and moderate or strong in 9 cases (56%). Staining was mainly detected in the liver extracellular matrix in parallel with the amount of liver fibrosis. Liver from fa/fa rats also showed CTGF overexpression by comparison with Fa/fa rats both at the messenger RNA (mRNA) level (3-fold increase) and protein level. In vitro, both CTGF mRNA and protein were significantly increased when hepatic stellate cells were incubated with either glucose or insulin. A slight increase in type I procollagen mRNA level was also observed in hepatic stellate cells incubated with glucose. In conclusion, this study suggests that hyperglycemia and insulin are key-factors in the progression of fibrosis in patients with NASH through the up-regulation of CTGF.
Caspase activation correlates with the degree of inflammatory liver injury in chronic hepatitis C virus infection
Authors: Bantel Heike , Lügering Andreas , Poremba Christopher , Lügering Norbert , Held Jürgen , Domschke Wolfram , Schulze-Osthoff Klaus
Published: August 2002

Hepatitis C virus (HCV) infection is a major cause of liver disease characterized by inflammation, cell damage, and fibrotic reactions of hepatocytes. Apoptosis has been implicated in the pathogenesis, although it is unclear whether proteases of the caspase family as the central executioners of apoptosis are involved and how caspase activation contributes to liver injury. In the present study, we measured the activation of effector caspases in liver biopsy specimens of patients with chronic HCV infection. The activation of caspase-3, caspase-7, and cleavage of poly(ADP-ribose)polymerase (PARP), a specific caspase substrate, were measured by immunohistochemistry and Western blot analysis by using antibodies that selectively detect the active truncated, but not the inactive precursor forms of the caspases and PARP. We found that caspase activation was considerably elevated in liver lobules of HCV patients in comparison to normal controls. Interestingly, the immunoreactive cells did yet not reveal an overt apoptotic morphology. The extent of caspase activation correlated significantly with the disease grade, i.e., necroinflammatory activity. In contrast, no correlation was observed with other surrogate markers such as serum transaminases and viral load. In biopsy specimens with low activity (grade 0) 7.7% of the hepatocytes revealed caspase-3 activation, whereas 20.9% of the cells stained positively in grade 3. Thus, our results suggest that caspase activation is involved in HCV-associated liver injury. Moreover, measurement of caspase activity may represent a reliable marker for the early detection of liver damage, which may open up new diagnostic and therapeutic strategies in HCV infection.
Prevalence of naturally occurring surface gene variants of hepatitis B virus in nonimmunized surface antigen-negative Chinese carriers
Authors: Hou Jinlin , Wang Zhanghui , Cheng Jinjun , Lin Yulong , Lau George K. K. , Sun Jian , Zhou Fuyuan , Waters Jenny , Karayiannis Peter , Luo Kangxian
Published: August 2002

Previous studies have suggested that hepatitis B virus (HBV) variants may account for the presence of HBV DNA in hepatitis B surface antigen (HBsAg)-negative patients (occult HBV infection). However, it is not known how widespread these variants are and how they influence the course of liver disease. To determine the prevalence of variants within the major hydrophilic region (MHR) of HBsAg, we investigated 2,565 subjects, including subjects with chronic hepatitis, cryptogenic cirrhosis, hemodialysis patients, and blood donors. Fifty-one of them had occult HBV infection. The entire S gene from 46 of these patients was sequenced from amplified serum HBV DNA. Forty-three percent (20 of 46) had mutations in the MHR of HBsAg. Thirty-two amino acid substitutions between positions 100-160 of the MHR of HBsAg were detected in 18 patients, and these ranged from 1 to 4 per patient. These changes involved 11 positions inside and 5 outside of the historical first and second loops of the “a” determinant, and included the following: Q101K, T115A, K122N, T123A, T126N, Q129N, G130R, T131I, M133T, F134L, C138Y, K141E, P142S, G145R, N146S, and C147F/R. Combinations of mutations were detected in 9 patients, and 7 of these have not been described before. Two further patients had insertion mutations immediately before the “a” determinant. Monoclonal antibody binding tests with the Royal Free hepatitis B surface (RFHBs) panel of antibodies revealed decreased immunoreactivity in 6 novel variants of HBsAg. The existence of patients with occult HBV infection caused by HBsAg variants, therefore, has implications for their possible transmission through sexual contact and by blood transfusion.
Up-regulated expression of the receptor for advanced glycation end products in cultured rat hepatic stellate cells during transdifferentiation to myofibroblasts
Authors: Fehrenbach Heinz , Weiskirchen Ralf , Kasper Michael , Gressner Axel M.
Published: August 2002

Receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily of cell-surface molecules. Blockade of RAGE has been reported to considerably improve liver function and accelerate regeneration after hepatectomy. The aim of this study was to investigate the cell type-specific expression of RAGE, and to examine whether transdifferentiation of hepatic stellate cells (HSC) into myofibroblasts (MFB) is associated with changes in RAGE expression. Northern blot analysis revealed that RAGE mRNA was exclusively expressed by HSC isolated from rat liver, while no transcripts were seen in hepatocytes, Kupffer cells, or sinusoidal endothelial cells. Expression of RAGE mRNA was up-regulated during transdifferentiation of HSC into MFB. Concomitantly, expression of RAGE protein was increased as confirmed by Western blotting and immunohistochemistry. As assessed by radioactive labeling, transforming growth factor β1 (TGF-β1) induced a time-dependent 2- to 15-fold increase in the de novo synthesis of RAGE protein, which was completely abolished using PD098059, a specific inhibitor of the mitogen-activated protein kinase (MAPK) kinase. As shown by double-immunofluorescence staining, RAGE colocalized with α-smooth muscle actin, and immunoelectron microscopy demonstrated the most prominent labeling for RAGE at filopodial membranes of MFB. In conclusion, this study demonstrates that expression of RAGE is restricted to rat HSC, and that expression is up-regulated during activation of HSC and transition to MFB. The preferential immunogold labeling of RAGE to focal membrane areas of filopodia of MFB is suggestive of a role of RAGE in the spreading and migration of activated HSC/MFB, major players in liver fibrogenesis.
Patterns of regional sympathetic nerve traffic in preascitic and ascitic cirrhosis
Authors: Pozzi Massimo , Grassi Guido , Redaelli Elena , Dell'Oro Raffaella , Ratti Laura , Redaelli Alessandro , Foglia Gerardo , Di Lelio Alessandro , Mancia Giuseppe
Published: August 2002

Overactivity of the sympathetic nervous system and portal hypertension are key factors in the development of ascites in cirrhosis. The sympathoexcitation that characterizes the more advanced stages of liver diseases is less clearly defined in preascitic cirrhosis. We measured sympathetic nerve traffic to skeletal muscle (peroneal nerve) and to skin districts by microneurography in (1) 12 Child class A cirrhotic patients with clinically significant portal hypertension (portal pressure gradient > 10 mm Hg, 14.8 ± 1.2 mm Hg, mean ± SEM) but without actual or previous ascites, (2) 16 Child class C cirrhotic patients with tense ascites, and (3) 10 patients with mild congestive heart failure, a condition paradigmatic of a marked sympathetic activation. Muscle sympathetic nerve traffic was markedly increased in Child class C subjects as compared with controls (23.9 ± 1.6 bursts/min, P < .01) and superimposable to that recorded in heart failure patients (52.9 ± 4.7 vs. 60.3 ± 2 bursts/min, P = not significant). Muscle sympathetic nerve traffic was also increased in Child class A subjects (41.6 ± 2 bursts/min, P < .01 vs. controls) although to a lesser extent (P < .05 vs. Child class C patients). Skin sympathetic nerve traffic was within the normal range in all patients. Neurohormones were all markedly increased in Child class C subjects. Only norepinephrine was increased in Child class A patients. Our data show that sympathetic nerve traffic activation (1) is already detectable in Child class A cirrhosis when clinically significant portal hypertension is present but ascites never developed and (2) is not generalized because although muscle traffic is increased, skin traffic is within normal range. The role of drugs modulating sympathoactivation should be investigated in preascitic cirrhosis.
Impact of gastroenterology consultation on the outcomes of patients admitted to the hospital with decompensated cirrhosis
Authors: Bini Edmund J. , Weinshel Elizabeth H. , Generoso Ramon , Salman Loay , Dahr Georges , Pena-Sing Ivan , Komorowski Thomas
Published: August 2002

Managed care has strongly discouraged generalists from referring patients to specialists in an effort to reduce the costs of health care. The aim of this study was to compare patient outcomes when generalists work together with gastroenterologists or alone in the management of patients admitted to the hospital with decompensated cirrhosis. Consecutive patients admitted to the hospital with decompensated cirrhosis over a 1-year period were identified. We compared the length of stay, cost of hospitalization, incidence of hospital readmission, and mortality for patients who did and those who did not have a gastroenterology (GI) consultation. A GI consultation was requested for 107 of the 197 patients (54.3%). Patients who had a GI consultation had a significantly shorter length of stay (5.6 ± 3.5 vs. 10.1 ± 5.8 days, P < .001) and a lower cost of hospitalization ($6,004 ± $4,994 vs. $10,006 ± $6,183, P < .001) than those patients who were managed by generalists alone. The 30-day incidence of readmission (13.3% vs. 27.8%, P = .01) and mortality (7.5% vs. 16.7%, P = .045) were significantly lower in the GI consultation group. During a median follow-up of 618 days (range, 2-970), patients who had a GI consultation during hospitalization had a significantly longer time to hospital readmission (P < .001) and improved survival (P = .02) compared with those who were managed by generalists alone. In conclusion, for patients admitted to the hospital with decompensated cirrhosis, individuals who were managed by generalists in conjunction with gastroenterologists had better outcomes than those who were managed by generalists alone.
Notch receptor expression in adult human liver: A possible role in bile duct formation and hepatic neovascularization
Authors: Nijjar Sarbjit S. , Crosby Heather A. , Wallace Lorraine , Hubscher Stefan G. , Strain Alastair J.
Published: August 2002

Notch signaling is an evolutionarily conserved mechanism, used to regulate cell fate decisions. Four Notch receptors have been identified in man (Notch-1 to -4). In this study, semiquantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry were used to examine the expression pattern of Notch receptor genes in whole adult human liver and isolated liver cell preparations. All 4 receptors were expressed in the adult liver, with no significant differences in the levels of Notch-1, -2, and -4 messenger RNA (mRNA) between normal and diseased liver. However, Notch-3 expression appeared to be increased in diseased tissue. The distribution of Notch-1 and -4 in normal tissue was similar, with Notch-1 also detectable at low levels in the sinusoidal endothelium. Notch-2 expression was more widely distributed, and detectable in hepatocytes, medium-sized bile ducts, and the sinusoidal endothelium. Notch-3 expression was seen on hepatocytes, with weaker expression detectable in portal veins, hepatic arteries, and the sinusoids. In normal liver tissue Notch-1, -2, and -3 were found to be coexpressed on bile duct epithelium; however, with the exception of Notch-3 in primary sclerosing cholangitis (PSC) livers, expression was absent on proliferating ductules in all disease states examined. Interestingly, the expression of Notch-2 and -3 was associated with numerous small vessels within the portal tract septa of diseased tissue. The absence of Notch receptor expression on proliferating bile ductules and its presence on neovessels suggests that Notch signaling may be important for normal bile duct formation and the aberrant neovascularization seen in diseased liver tissue.
γ-Glutamyl transpeptidase overexpression increases metastatic growth of B16 melanoma cells in the mouse liver
Authors: Obrador Elena , Carretero Julian , Ortega Angel , Medina Ignacio , Rodilla Vicente , Pellicer José A. , Estrela José M.
Published: August 2002

B16 melanoma (B16M) cells with high glutathione (GSH) content show rapid proliferation in vitro and high metastatic activity in the liver in vivo. γ-Glutamyl transpeptidase (GGT)-mediated extracellular GSH cleavage and intracellular GSH synthesis were studied in vitro in B16M cells with high (F10) and low (F1) metastatic potential. GGT activity was modified by transfection with the human GGT gene (B16MF1/Tet-GGT cells) or by acivicin-induced inhibition. B16MF1/Tet-GGT and B16MF10 cells exhibited higher GSH content (35 ± 6 and 40 ± 5 nmol/106 cells, respectively) and GGT activity (89 ± 9 and 37 ± 7 mU/106 cells, respectively) as compared (P < .05) with B16MF1 cells (10 ± 3 nmol GSH and 4 mU GGT/106 cells). Metastasis (number of foci/100 mm3 of liver) increased in B16MF1 cells pretreated with GSH ester (˜3-fold, P < .01), and decreased in B16MF1/Tet-GGT and B16MF10 cells pretreated with the GSH synthesis inhibitor L-buthionine (S,R)-sulphoximine (˜5-fold and 2-fold, respectively, P < .01). Liver, kidney, brain, lung, and erythrocyte GSH content in B16MF1/Tet-GGT- or B16MF10-bearing mice decreased as compared with B16MF1- and non-tumor-bearing mice. Organic anion transporting polypeptide 1-independent sinusoidal GSH efflux from hepatocytes increased in B16MF1/Tet-GGT- or B16MF10-bearing mice (˜2-fold, P < .01) as compared with non-tumor-bearing mice. Our results indicate that tumor GGT activity and an intertissue flow of GSH can regulate GSH content of melanoma cells and their metastatic growth in the liver.
S-adenosylmethionine and methylthioadenosine are antiapoptotic in cultured rat hepatocytes but proapoptotic in human hepatoma cells
Authors: Ansorena Eduardo , García-Trevijano Elena R. , Martínez-Chantar Maria L. , Huang Zong-Zhi , Chen Lixin , Mato José M. , Iraburu Maria , Lu Shelly C. , Avila Matías A.
Published: August 2002

S-adenosylmethionine (AdoMet) is an essential compound in cellular transmethylation reactions and a precursor of polyamine and glutathione synthesis in the liver. In liver injury, the synthesis of AdoMet is impaired and its availability limited. AdoMet administration attenuates experimental liver damage, improves survival of alcoholic patients with cirrhosis, and prevents experimental hepatocarcinogenesis. Apoptosis contributes to different liver injuries, many of which are protected by AdoMet. The mechanism of AdoMet's hepatoprotective and chemopreventive effects are largely unknown. The effect of AdoMet on okadaic acid (OA)-induced apoptosis was evaluated using primary cultures of rat hepatocytes and human hepatoma cell lines. AdoMet protected rat hepatocytes from OA-induced apoptosis dose dependently. It attenuated mitochondrial cytochrome c release, caspase 3 activation, and poly(ADP-ribose) polymerase cleavage. These effects were independent from AdoMet-dependent glutathione synthesis, and mimicked by 5'-methylthioadenosine (MTA), which is derived from AdoMet. Interestingly, AdoMet and MTA did not protect HuH7 cells from OA-induced apoptosis; conversely both compounds behaved as proapoptotic agents. AdoMet's proapoptotic effect was dose dependent and observed also in HepG2 cells. In conclusion, AdoMet exerts opposing effects on apoptosis in normal versus transformed hepatocytes that could be mediated through its conversion to MTA. These effects may participate in the hepatoprotective and chemopreventive properties of this safe and well-tolerated drug.
In vivo cell lineage analysis in cyproterone acetate-treated rat liver using genetic labeling of hepatocytes
Authors: Auvigne Isabelle , Pichard Virginie , Aubert Dominique , Robillard Nelly , Ferry Nicolas
Published: August 2002

Genetic labeling using recombinant retroviruses is a powerful strategy for the study of cell lineage in the liver. However, this type of vector is only able to infect dividing cells. The synthetic steroid cyproterone acetate (CPA) is mitogenic and carcinogenic in the adult rat liver. In this study, we used retroviral vectors carrying the nuclear targeted β-galactosidase gene to selectively label and follow the fate of hepatocytes dividing on administration of CPA. Labeled cells as well as those in mitosis were preferentially located around the portal tract, whereas apoptotic bodies were predominant in the pericentral area. Labeled hepatocytes did not disappear after apoptosis, suggesting a preferential elimination of nontransduced cells. The presence of labeled binucleated hepatocytes showed the persistence of a binucleation process. Finally, we performed long-term analysis of labeled cells in transgenic animals tolerant for β-galactosidase and treated with 2-acetylaminofluorene (2-AAF) to promote the growth of CPA-initiated hepatocytes. The presence of β-galactosidase-positive hepatocyte clones showed that hepatocytes divided during treatment with 2-AAF. Only 3% of β-galactosidase clones were positive for the placental form of glutathione S-transferase (GSTp), indicating the absence of a preferential appearance of preneoplastic foci in the population of β-galactosidase-labeled hepatocytes. In conclusion, our results show that the mitogenic and tumor-initiating activities of CPA are directed toward different hepatocyte populations.
Variants of two major T cell epitopes within the hepatitis B surface antigen are not recognized by specific T helper cells of vaccinated individuals
Authors: Bauer Tanja , Weinberger Klaus , Jilg Wolfgang
Published: August 2002

Several naturally occurring variants of immunogenic T cell epitopes were identified within the hepatitis B surface antigen (HBsAg). The effect of these variants on the cellular immune response was studied in individuals vaccinated against HBV. Class-II restricted T-cell responses of 30 vaccinees were analyzed after stimulation of peripheral blood mononuclear cells (PBMCs) with 4 synthetic peptides representing the 4 T-cell epitopes of HBsAg known as of yet. The 2 epitopes P1 (aa 16-33) and P4 (aa 213-226) could be identified as the dominant ones in our vaccinees by proliferation assays and enzyme-linked immunospot assays. Responses to these epitopes were compared with responses to their naturally occurring variants found in HBV isolates of chronic virus carriers. Three of 11 variants of epitope P4 led to a complete loss of T-cell reactivity in 4 of 10 donors, all of whom reacted well to the corresponding wild-type sequence. The remaining 6 donors recognized these variants as well as the vaccine epitope. Similarly, 3 P1-variants of the 12 found induced only a significantly reduced reactivity in 4 of 10 donors, whereas they led to a normal response in the other 6 individuals. Stimulation of T cells also induced the secretion of antibody to HBsAg (anti-HBs) by specific B cells; however, those peptides that failed to activate T cells were also unable to cause any significant anti-HBs production. In conclusion, our results suggest an immune escape of certain mutant strains of HBV in vaccinated individuals could exist at the T-cell level.
Histologic scoring of liver biopsy in focal nodular hyperplasia with atypical presentation
Authors: Fabre Aurélie , Audet Pascale , Vilgrain Valérie , Nguyen Bich N. , Valla Dominique , Belghiti Jacques , Degott Claude
Published: August 2002

The contribution of radio-guided transcutaneous biopsy in the diagnosis of focal nodular hyperplasia (FNH) of the liver was compared with the findings on surgical specimens to assess its contribution in clinical and radiologic atypical cases. This retrospective study involved 30 patients with atypical tumors on imaging who underwent liver biopsy and then surgery. All surgical specimens were diagnosed as FNH, either classical (n = 18) or nonclassical (n = 12). Imaging data were reviewed according to 4 radiologic criteria on magnetic resonance imaging (MRI) and/or computed tomography (CT) scan (hypervascularity, homogeneity, nonencapsulation, and presence of a central scar), and classified depending on the number of criteria found (group I, 4 of 4; group II, 3 of 4; group III, 2 or fewer). Histologic assessment of ultrasound (US)-guided liver biopsy recorded major diagnostic features (fibrous bands, thick-walled vessels, reactive ductules, and nodularity) and minor features (sinusoidal dilatation and perisinusoidal fibrosis). “Definite FNH” (3 or 4 major features) was diagnosed in 14 biopsies, “possible FNH” (2 major and 1 or 2 minor features) in 7 cases, and “negative for FNH” (2 or fewer major features without minor features) in 9 cases. The diagnosis of FNH on biopsy was reached in 14 cases (58.3%) in patients with 2 or fewer imaging criteria (group III; n = 24). Biopsies with a diagnosis of “possible FNH” corresponded to a large proportion of telangiectatic-type FNH on the specimen. In conclusion, liver biopsy does not appear to be necessary in cases in which imaging is typical. However, the absence of radiologic diagnostic criteria in FNH does not preclude a positive diagnosis on liver needle biopsy. Using the proposed histologic scoring system, surgical management may be avoided in these cases.
Absence of nuclear factor κB inhibition by NSAIDs in hepatocytes
Authors: Callejas Nuria A. , Casado Marta , Boscá Lisardo , Martín-Sanz Paloma
Published: August 2002

Stimulation of fetal hepatocytes with proinflammatory cytokines and lipopolysaccharide promotes the expression of cyclooxygenase-2 (COX-2) and nitric oxide synthase-2 (NOS-2), whereas the hepatoma cell line HepG2 exhibits a behavior similar to that described for adult hepatocytes and only expresses NOS-2. The effect of nonsteroidal anti-inflammatory drugs (NSAIDs) on the inflammatory onset was analyzed in these cells since in addition to the inhibition of cyclooxygenase activity, these drugs interfere with other signaling pathways related with the inflammatory response. Inhibition of nuclear factor κB (NF-κB) activation by aspirin and salicylate has been described in many cells. However, incubation of hepatic cells with salicylate, aspirin, indomethacin, ibuprofen, or 5,5-dimethyl-3(3-fluorophenyl)-4-(4-methylsulfonyl)phenyl-2(5H)-furanone (DFU), a fluorinated derivative of rofecoxib, failed to impair IκB kinase activity, the processing of NF-κB, and the expression of NF-κB-dependent genes, such as NOS-2. Moreover, selective COX-2 inhibitors did not promote apoptosis in hepatocytes under inflammatory conditions, suggesting that prostaglandins are not required to maintain cell viability. In conclusion, these data indicate that hepatocytes are not sensitive to NF-κB inhibition by NSAIDs and that these drugs, especially the COX-2 selective inhibitors, do not alter cell viability.
Inhibition of rat liver fibrogenesis through noradrenergic antagonism
Authors: Dubuisson Liliane , Desmoulière Alexis , Decourt Boris , Evadé Laetitia , Bedin Christiane , Boussarie Liliane , Barrier Laurence , Vidaud Michel , Rosenbaum Jean
Published: August 2002

The effect of adrenergic innervation and/or circulating catecholamines on the function of liver fibrogenic cells is poorly understood. Our aim was to investigate the effects of noradrenergic antagonism on carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Two weeks of CCl4 induced a ˜5-fold increase in the area of fibrosis as compared with controls. The addition of 6-hydroxydopamine (OHDA), a toxin that destroys noradrenergic fibers, decreased fibrosis by 60%. After 6 weeks of CCl4, the area of fibrosis increased about 30-fold in CCl4-treated animals and was decreased by 36% with OHDA. At 2 weeks, OHDA abrogated the CCl4-induced increase in mRNA level of tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), an inhibitor of extracellular matrix degradation, and it greatly reduced it at 6 weeks. Finally, when rats treated with CCl4 for 2 weeks also received prazosin, an antagonist of α1-adrenergic receptors, fibrosis was decreased by 83%. In conclusion, destruction of noradrenergic fibers or antagonism of noradrenergic signaling through α1 receptors inhibited the development of liver fibrosis. Because adrenoreceptor antagonists have a very sound safety profile, they appear as attractive drugs to reduce liver fibrogenesis.
Expression of interferon alfa signaling components in human alcoholic liver disease
Authors: Nguyen Van-Anh , Gao Bin
Published: August 2002

Interferon alfa (IFN-α) is currently the only well-established therapy for viral hepatitis. However, its effectiveness is much reduced (<10%) in alcoholic patients. The mechanism underlying this resistance is not fully understood. In this study, we examined the expression of IFN-α signaling components and its inhibitory factors in 9 alcoholic liver disease (ALD) and 8 healthy control liver tissues. In comparison with normal control livers, expression of IFN-β, IFN-α receptor ½, Jak1, and Tyk2 remained unchanged in ALD livers, whereas expression of IFN-α, signal transducer and activator of transcription factor 1 (STAT1), and p48 were up-regulated and expression of STAT2 was down-regulated. Expression of antiviral MxA a karyophilic 75 kd protein induced by IFN in mouse cells carrying the influenza virus resistance allele Mx+ and 2'-5' oligoadenylate synthetase (OAS) proteins was not regulated, whereas expression of double-stranded RNA-activated protein kinase (PKR) was decreased by 55% in ALD livers. Three families of inhibitory factors for the JAK-STAT signaling pathway were examined in ALD livers. Members of the suppressor of cytokine signaling (SOCS) family, including SOCS 1, 2, 3, and CIS, and the protein tyrosine phosphatases, including Shp-1, Shp-2, and CD45, were not up-regulated in ALD livers, whereas the phosphorylation of and protein levels of p42/44 mitogen-activated protein kinase (p42/44MAP kinase) were increased about 3.9- and 3.2-fold in ALD livers in comparison with normal control livers, respectively. In conclusion, these findings suggest that chronic alcohol consumption down-regulates STAT2 and PKR, but up-regulates p42/44 mitogen-activated protein kinase (p42/44MAP kinase), which may cause down-regulation of IFN-α signaling in the liver of ALD patients.
Modeling the hepatitis C virus epidemic in France using the temporal pattern of hepatocellular carcinoma deaths
Authors: Griffiths Jenny , Nix Barry
Published: August 2002

Deuffic et al. developed a compartmentalized model that characterized the evolution and spread of the hepatitis C virus (HCV) within France. There were various parameters defining the age- and sex-dependent transition probabilities between chronic hepatitis and cirrhosis in need of determination to completely specify their model. These were estimated by means of a weighted least-squares procedure that was executed numerically. The objective function used was based on the distribution of the age at death from hepatocellular carcinoma (HCC) rather than the temporal pattern of deaths due to HCC from 1979 to 1995. In this report, we investigate the impact of using an objective function based on the temporal pattern of deaths. We show that the dynamics of the epidemic can be quite different, in particular, short-term prediction of HCC deaths by HCV infection and times to death from onset of disease.
Differentiation-dependent and subset-specific recruitment of T-helper cells into murine liver
Authors: Klugewitz Katja , Topp Stefan Andreas , Dahmen Uta , Kaiser Toralf , Sommer Sabine , Kury Evelyn , Hamann Alf
Published: August 2002

It has been suggested that the liver traps and deletes activated and potentially harmful T cells, especially of the CD8+ subset, providing mechanisms to limit systemic immune responses. It is unknown whether this also applies to CD4+ T cells. In this study, we show that activated stages of CD4+ T cells were trapped in the liver on intraportal injection. Intravital microscopy showed an immediate adhesion of activated CD4+ T cells within periportal sinusoids after intraportal injection. Furthermore, we detected high frequencies of interferon gamma (IFN-γ)- (Th1) and interleukin 4 (IL-4)- (Th2) synthesizing effector cells in the liver. Transfer experiments were performed to identify those phenotypes showing specific retention in the liver. Our data show that effector stages and activated cells in general are more efficiently recruited into the liver than resting CD4+ T cells, similar to what has previously been shown for CD45RBlow memory cells. In addition, we observed a certain preference for Th1-polarized cells to be trapped by the liver. However, the actual cytokine-producing cells did not specifically enrich among the total population. In conclusion, these data indicate that the liver acts as a filter for activated and memory/effector cells. Cells trapped in the liver might subsequently undergo modulatory influences exerted by the postulated specific microenvironment of the liver.
Relationship of health-related quality of life to treatment adherence and sustained response in chronic hepatitis C patients
Authors: Bernstein David , Kleinman Leah , Barker Chris M. , Revicki Dennis A. , Green Jesse
Published: August 2002

Interferon therapy may exacerbate health-related quality of life (HRQL) deficits associated with hepatitis C virus (HCV) early in the course of therapy. Treatment with polyethylene glycol-modified interferon (peginterferon) alfa-2a (40 kd) provides improved sustained response over interferon alfa-2a, but its effect on HRQL is unknown. The objective of this study was to (1) evaluate the effect of sustained virologic response on HRQL in patients with HCV and (2) determine whether impairment of HRQL during treatment contributes to early treatment discontinuation. Data consisted of a pooled secondary analysis of patients (n = 1,441) across 3 international, multicenter, open-label, randomized studies that compared peginterferon alfa-2a (40 kd) with interferon alfa-2a. ANCOVA was used to examine the effect of sustained virologic response on HRQL. Repeated-measures mixed-models ANCOVA was used to compare Fatigue Severity Scale (FSS) and SF-36 scores during treatment by treatment group. Logistic regression analysis was used to examine the association between changes at baseline in on-treatment HRQL and early treatment discontinuation. Sustained virologic response was associated with marked improvements from baseline to end of follow-up in all subjects, including patients with cirrhosis. During treatment, patients receiving peginterferon alfa-2a (40 kd) had statistically significantly better scores on both the SF-36 and FSS. Baseline to 24-week changes in fatigue and SF-36 mental and physical summary scores significantly predicted treatment discontinuation. In conclusion, sustained virologic response is associated with improvements in quality of life in patients with or without advanced liver disease. This parameter may be an important consideration in maximizing treatment adherence.
COX-2 inhibits Fas-mediated apoptosis in cholangiocarcinoma cells
Authors: Nzeako Ugochukwu C. , Guicciardi Maria Eugenia , Yoon Jung-Hwan , Bronk Steven F. , Gores Gregory J.
Published: August 2002

Fas expression has been shown to negatively regulate the progression of cholangiocarcinoma cells in xenografts. However, many human cholangiocarcinomas express Fas, suggesting these cancers have developed mechanisms to inhibit Fas-mediated apoptosis. Cyclooxygenase-2 (COX-2), which generates prostanoids, is expressed by many cholangiocarcinomas. Therefore, our aim was to determine whether COX-2 expression inhibits death receptor-mediated apoptosis in KMBC cells, a cholangiocarcinoma cell line. These cells express messenger RNA for the death receptors Fas, tumor necrosis factor receptor 1 (TNF-R1), death receptor 4 (DR4), and DR5. Agonists for these death receptors, CH-11, TNF-α, and TRAIL all induced apoptosis. However, COX-2, whether induced by proinflammatory cytokines or transient transfection, only significantly inhibited Fas-mediated apoptosis. The COX-2 inhibitor NS-398 restored Fas-mediated apoptosis in COX-2 transfected cells. Prostaglandin E2 reduced apoptosis and mitochondrial depolarization after treatment with the Fas agonist CH-11. Of a variety of antiapoptotic proteins examined, COX-2/prostaglandin E2 only increased expression of Mcl-1, an antiapoptotic member of the Bcl-2 family. In conclusion, these data suggest that prostanoid generation by COX-2 specifically inhibits Fas-mediated apoptosis, likely by up-regulating Mcl-1 expression. Pharmacologic inhibition of COX-2 may be useful in augmenting Fas-mediated apoptosis of cholangiocarcinoma cells.
Acute versus chronic alcohol consumption in acetaminophen-induced hepatotoxicity
Authors: Schmidt Lars E. , Dalhoff Kim , Poulsen Henrik Enghusen
Published: August 2002

The aim of this study was to determine by multivariate analysis how alcohol and other factors affect the clinical course and outcome in patients with acetaminophen (paracetamol) poisoning. A total of 645 consecutive patients admitted from 1994 to 2000 with single-dose acetaminophen poisoning were studied, giving special attention to alcohol history, time between overdose and intravenous N-acetylcysteine (NAC) treatment (“time to NAC”), and other data available at the time of admittance. Up until 72 hours after ingestion, time to NAC was the single most important independent risk factor. With a time to NAC less than 12 hours, the mortality rate was 0.42% (95% CI, 0.05-2.7). When time to NAC exceeded 12, 24, and 48 hours, the mortality rate increased to 6.1%, 13%, and 19%, respectively. Chronic alcohol abuse was an independent risk factor of mortality (odds ratio [OR], 3.52; 95% CI, 1.78-6.97). Acute alcohol ingestion was an independent protective factor regarding mortality in alcoholic patients (OR, 0.08; 95% CI, 0.01-0.66) but not in nonalcoholic patients (OR, 0.21; 95% CI, 0.03-1.67). Patient age and quantity of acetaminophen were independent risk factors. In conclusion, time to NAC was confirmed as the major risk factor in acetaminophen-induced hepatotoxicity and mortality. Chronic alcohol abuse was an independent risk factor that could be counteracted by concomitant acute alcohol ingestion. We suggest that patients with chronic alcoholism and suspected acetaminophen poisoning due to an increased risk of developing hepatotoxicity should be treated with NAC regardless of risk estimation.
Ex vivo exposure to carbon monoxide prevents hepatic ischemia/reperfusion injury through p38 MAP kinase pathway
Authors: Amersi Farin , Shen Xiu-Da , Anselmo Dean , Melinek Judy , Iyer Suhasani , Southard Daniel J. , Katori Masamichi , Volk Hans-Dieter , Busuttil Ronald W. , Buelow Roland , Kupiec-Weglinski Jerzy W.
Published: August 2002

A direct role of carbon monoxide (CO), an effector-signaling molecule during heme oxygenase-1 (HO-1) catalysis of heme, in the protection against hepatic ischemia/reperfusion (I/R) injury needs to be established. This study was designed to determine the effects and downstream mechanisms of CO on cold I/R injury in a clinically relevant isolated perfusion rat liver model. After 24 hours of cold storage, rat livers perfused ex vivo for 2 hours with blood supplemented with CO (300 parts per million) showed significantly decreased portal venous resistance and increased bile production, as compared with control livers perfused with blood devoid of CO. These beneficial effects correlated with improved liver function (serum glutamic oxaloacetic transaminase levels) and diminished histological features of hepatocyte injury (Banff's scores). The CO-mediated cytoprotective effects were nitric oxide synthase- and cyclic guanine monophosphate-independent, but p38 mitogen-activated protein kinase (MAPK)-dependent. Moreover, adjunctive use of zinc protoporphyrin, a competitive HO-1 inhibitor, has shown that exogenous CO could fully substitute for endogenous HO-1 in preventing hepatic I/R insult. This study performed in a clinically relevant ex vivo cold ischemia model is the first to provide the evidence that HO-1-mediated cytoprotection against hepatic I/R injury depends on the generation of, and can be substituted by, exogenous CO. The p38 MAPK signaling pathway represents the key downstream mechanism by which CO prevents the I/R insult. In conclusion, regimens that employ exogenous CO should be revisited, as they may have potential applications in preventing/mitigating I/R injury, and thus expanding the liver donor pool for clinical transplantation.